Previously, mouse bone marrow-derived stem cells （MSC） treated with the unspecific DNA methyltransferase inhibitor 5-azacytidine were reported to differentiate into cardiomyocytes. The aim of the present study was t...Previously, mouse bone marrow-derived stem cells （MSC） treated with the unspecific DNA methyltransferase inhibitor 5-azacytidine were reported to differentiate into cardiomyocytes. The aim of the present study was to investigate the efficiency of a similar differentiation strategy in human mononuclear cells obtained from healthy bone marrow donors. After 1-3 passages, cultures were exposed for 24 h to 5-azacytidine （3 μM） followed by 6 weeks of further culture. Drug treatment did not induce expression of myogenic marker MyoD or cardiac markers Nkx2.5 and GATA-4 and did not yield beating cells during follow-up. In patch clamp experiments, approximately 10-15% of treated and untreated cells exhibited L-type Ca^2＋ currents. Almost all cells showed outwardly rectifying K^＋ currents of rapid or slow activation kinetics. Mean current amplitude at ＋60 mV doubled after 6 weeks of treatment compared with time-matched controls. Membrane capacitance of treated cells was significantly larger than in controls 2 weeks after treatment and remained high after 6 weeks, Expression levels of mRNAs for the K^＋ channels Kv 1,1, Kv 1,5, Kv2,1, Kv4,3 and KCNMA 1 and for the Ca^2＋ channel Cav 1.2 were not affected by 5-azacytidine. Treatment with potassium channel blockers tetraethylammonium and clofilium at concentrations shown previously to inhibit rapid or slowly activating K^＋ currents of hMSC inhibited proliferation of these cells. Our results suggest that despite the absence of differentiation ofhMSC into cardiomyocytes, treatme.nt with 5-azacytidine caused profound changes in current density.展开更多
When Aerodrome Obstacle Standards cannot be met as a result of urban or technical development, an aeronautical study can be carried out with the permission of EASA, in conjunction with ICAO, to prove how aircrafts can...When Aerodrome Obstacle Standards cannot be met as a result of urban or technical development, an aeronautical study can be carried out with the permission of EASA, in conjunction with ICAO, to prove how aircrafts can achieve an equivalent level of safety. However currently, no detailed guidance for this procedure exists. This paper proposes such a safety assessment methodology in order to value obstacle clearance violations around airports. This method has already been applied to a safety case at Frankfurt Airport where a tower elevating 4 km out of threshold 25R severely violates obstacle limitation surfaces. The model data refers to a take-off and landing performance model (TLPM) computing precisely aircraft trajectories for both standard and engine out conditions at ground proximity. The generated tracks are used to estimate collision risk incrementally considering EASA/FAA, EU-OPS & ICAO clearance criteria. Normal operations are assessed with a probabilistic analysis of empirical take-off/landing track data generating the local actual navigation performance (ANP) on site. The ANP shows integration to collision risk for an aircraft with any obstacle. The obstacle is tested for clearance within a “5-step-plan” against all performance requirements for landing climb and take-off climb. The methodology thereby delivers a comprehensive risk picture: The presented safety case for Frankfurt Airport showed an equivalent safety level despite the violation of standards. The collision risk during both normal and degraded performance operations was still found to be within ICAO Collision Risk Model (CRM) limits, requiring only limited risk mitigation measures. The presented work should complement ICAO Doc 9774 Appendix 3.展开更多
Radical prostatectomy in elderly patients is controversial. To identify very old candidates for radical prostatectomy with the highest probability of long-term survival, we studied 47 consecutive men who underwent rad...Radical prostatectomy in elderly patients is controversial. To identify very old candidates for radical prostatectomy with the highest probability of long-term survival, we studied 47 consecutive men who underwent radical prostatectomy between 1992 and 2005 at an age of 75 years or older. A heuristic approach was used to search for subgroups with particularly high long-term survival. Several two-sided comorbidity measures and combinations of these measures were investigated to find classifications best identifying healthy, long-living elderly candidates for radical prostatectomy. Four of the 25 two-sided comorbidity classifications or combinations reached the significance level with hazard ratios between 4.00 and 4.80. After 10 years, patients identified as healthy patients according to these comorbidity measurements had exhibited relative survival rates between 129% and 137% and overall survival rates between 86% and 95%, whereas those with comorbidities had exhibited relative survival rates of only 66%-84% and overall survival rates of 44%-58%. In conclusion, classifying comorbidity may identify a meaningful proportion of men selected for radical prostatectomy at an age of 75 years or older with an excellent long-term survival probability superseding that of the general population.展开更多
Causes, paths and interim results of the Arab Spring are discussed from the perspective of comparative revolutionary analysis. One has to distinguish revolutionary situations, with a multitude of conflict forms, from ...Causes, paths and interim results of the Arab Spring are discussed from the perspective of comparative revolutionary analysis. One has to distinguish revolutionary situations, with a multitude of conflict forms, from revolutionary outcomes. Also one should consider the options for development granted by different forms of political authority. Sultanist rule here allows for only highly limited perspectives. Such a form of political authority is focused only on the ruler and his entourage. There is no developing of encompassing and persistent institutions that would allow for smooth political change and the provision of public goods characteristic of democratic order. Numerous other theoretical elements are drawn on in assessing the chances of transformation and possible scenarios. Population pressures by an extremely young and mostly unemployed or underemployed population and the lack of a regional power are two of the crucial burdens. Further, one finds persistent cultural-religious cleavages The Arab monarchies from Morocco to Saudi-Arabia have reacted with very limited political concessions and welfare payments to buy off protest sentiments. Thus far they could avoid regime failure as occurred to the more Sultanist regimes in Libya and Syria. In the second portion of this manuscript the security implications of the failed Arab spring are addressed in regional and global terms.展开更多
In a paper conceived about five years ago(“Globalization and Public Goods:Too Big to Tackle?”)roughly a dozen factors were linked to explain important causal paths from globalization to the potential output of publi...In a paper conceived about five years ago(“Globalization and Public Goods:Too Big to Tackle?”)roughly a dozen factors were linked to explain important causal paths from globalization to the potential output of public goods.The Russian invasion of Ukraine,the corona epidemic,and the increased hegemonic rivalry between China and the U.S.interrupted or even destroyed many of the linkages between globalization and potential public good production.About five important detrimental paths involved in the meantime.In the present article we aim at linking what is left from the previous level of globalization or emerging to form a new and simplified causal model for likely linkages between truncated or(re-)emerging globalization,and the deadly needed output of public goods.These linkages refer to rules of climate control,go to trade linkages and arbitrary tariffs and trade interventions.Regime change,regime formation,and alliance restructuring address aspects of domestic rule and international stability.Selectorate theory,regime type,and exit options for political elites provide key explanatory factors in explaining globalization and public goods productions,or their decay.Where possible we use some data and transformation experiences corroborating our arguments.In other instances need for further empirical macro research will become clear.展开更多
A series of clay/poly（N-isopropylacrylamide-co-acrylamide） nanocomposite hydrogels （S-N-M gels） have been successfully prepared by in situ polymerization. The mechanical properties, swelling behavior of S-N-M gels...A series of clay/poly（N-isopropylacrylamide-co-acrylamide） nanocomposite hydrogels （S-N-M gels） have been successfully prepared by in situ polymerization. The mechanical properties, swelling behavior of S-N-M gels and the transparency changes during polymerization of S-N-M gels have been systematically investigated. Compared to traditional hydrogels, S-N-M gels show excellent tensile properties and their swelling ratio increases with increasing acrylamide （AAm） content. The results of stress relaxation indicate that the stress loss decreases with increasing AAm content. It was surprisingly found that the transparency during all S-N-M gel synthesis changes abruptly, and the changes become more abrupt with increasing N-isopropylacrylamide content. It was concluded that the fact may be related to the hydrophilicity of copolymers. The weaker the hydrophilicity of copolymer, the more apparent the transparency change during S-N-M gels polymerization. We believe the relationship between hydrophilicity of copolymer and transparency changes will help to design novel nanocomposite hydrogels.展开更多
Compared to all other organs of the body the ratio pericyte per endothelial cell is very high in the retina. However, it is still unclear which local metabolic factor causes the feedback from retinal cells to adjust t...Compared to all other organs of the body the ratio pericyte per endothelial cell is very high in the retina. However, it is still unclear which local metabolic factor causes the feedback from retinal cells to adjust the capillary blood flow. Chen and Anderson (1997) could show that the effect of C02 on the intracellular pH and the contractility of pericytes was mediated primarily展开更多
The generalized 2-D problem of a half-infinite interfacial electrode layer between two arbitrary piezoelectric half-spaces is studied. Based on the Stroh formalism, exact expressions for the (Green's) functions of...The generalized 2-D problem of a half-infinite interfacial electrode layer between two arbitrary piezoelectric half-spaces is studied. Based on the Stroh formalism, exact expressions for the (Green's) functions of a line force, a line charge and a line electric dipole applied at an arbitrary point near the electrode edge,were presented, respectively. The corresponding solutions for the intensity factors of fields were also obtained in an explicit form. These results can be used as the foundational solutions in boundary element method (BEM) to solve more complicated fracture problems of piezoelectric composites.展开更多
To evaluate the validity of different indices in estimating soil readily mineralizable N, soil microbial biomass （Nmic）, soil active N （SAN）, soluble organic N （SON）, net N mineralization rate （NNR） and gross ...To evaluate the validity of different indices in estimating soil readily mineralizable N, soil microbial biomass （Nmic）, soil active N （SAN）, soluble organic N （SON）, net N mineralization rate （NNR） and gross N mineralization rate （GNR） in mineral soils （0-10 cm） from six forest stands located in central Germany were determined and compared with two sampling times： April and November. Additionally, soil density fractionation was conducted for incubated soils （with addition of ^15NH4-N and glucose, 40 days） to observe the sink of added ^15N in different soil fractions. The study showed that Nmic and NNR in most stands differed significantly （P 〈 0.05） between the two sampling times, but not GNR, SAN and SON. In November, no close relationships were found between GNR and other N indices, or between Nrnic, SON, and SAN and forest type. However, in April, GNR was significantly correlated （P 〈 0.05） with Nmic, SAN, and NNR along with Nmlc under beech being significantly higher （P 〈 0.05） than under conifers. Furthermore, density fractionation revealed that the light fraction （LF, 0.063-2 mm, 〉 1.7 gcm^-3） was not correlated with the other N indices. In contrast, results from the incubation study proved that more 15N was incorporated into the heavy fraction （HF 〈 0.063 ram, 〉 1.7 g cm^-3） than into LF, indicaing that more labile N existed in HF than in LF. These findings suggested that attention should be paid to the differences existing in N status between agricultural and forest soils.展开更多
The technology of anaerobic digestion of sewage and solid wastes regains people＇s attention, mainly due to high price of fossil fuel nowadays in most recent years. The main topic for batch test is to study the inhibi...The technology of anaerobic digestion of sewage and solid wastes regains people＇s attention, mainly due to high price of fossil fuel nowadays in most recent years. The main topic for batch test is to study the inhibitory effect and boundary conditions of organic acid （propionic acid） to anaerobic digesters. High concentrations ofpropionic acid are achieved by direct dosage of the acid. As it is thought to be highly inhibitory to the digester, we are expecting that： （1） the production rate of methane declines and finally stops when the acid gradually accumulates; （2） the propionic acid will displace stronger inhibition under lower pH values. The results of the batch tests will assist engineers to better control anaerobic digesters and react to potential digester crises caused by propionic acid before it is too late.展开更多
Continuously rising demands of legislators require a significant reduction of CO2-emission and thus fuel consumption across all vehicle classes. In this context, lightweight construction materials and designs become a...Continuously rising demands of legislators require a significant reduction of CO2-emission and thus fuel consumption across all vehicle classes. In this context, lightweight construction materials and designs become a single most important factor. The main engineering challenge is to precisely adapt the material and component properties to the specific load situation. However, metallic car body structures using “Tailored blanks” or “Patchwork structures” meet these requirements only insufficiently, especially for complex load situations (like crash). An innovative approach has been developed to use laser beams to locally strengthen steel crash structures used in vehicle bodies. The method tailors the workpiece hardness and thus strength at selected locations to adjust the material properties for the expected load distribution. As a result, free designable 3D-strengthening-patterns surrounded by softer base metal zones can be realized by high power laser beams at high processing speed. The paper gives an overview of the realizable process window for different laser treatment modes using current high brilliant laser types. Furthermore, an efficient calculation model for determining the laser track properties (depth/width and flow curve) is shown. Based on that information, simultaneous FE modelling can be efficiently performed. Chassis components are both statically and cyclically loaded. Especially for these components, a modulation of the fatigue behavior by laser-treated structures has been investigated. Simulation and experimental results of optimized crash and deep drawing components with up to 55% improved level of performance are also illustrated.展开更多
I n a recently published study, the results of the Prostate Cancer Intervention ver-sus Observation Trial （PIVOT） trial were compared with that of the Scandinavian Prostate Cancer Group Study Number 4 （SPCG-4）. ...I n a recently published study, the results of the Prostate Cancer Intervention ver-sus Observation Trial （PIVOT） trial were compared with that of the Scandinavian Prostate Cancer Group Study Number 4 （SPCG-4）. The authors concluded that the discrepancy of the mortality rates between both studies may be explained by screen- related lead time and over-diagnosis. In this comment, some potential biases are dis- cussed and the limited applicability of the results of both randomized trials to healthy candidates for radical prostatectomy is underlined. The results of the Prostate Cancer Inter- vention versus Observation Trial （PWOT）1 raised questions on the efficacy of radical prostatectomy in men with low-risk prostate cancer. Xia and co-workers2 used simulation modeling to determine whether the reduced absolute survival benefit in the PIVOT trial1 compared with Scandinavian Prostate Cancer Group Study Number 43 may be explained by the high prevalence of screen-detected prostate cancers in the PIVOT study. The authors concluded that the discrepancy of the mortality rates between both studies may largdy be explained by screen-rdated lead time and over-diagnosis and should not be considered as an argument against the efficacy of radical prostatectomy even in the presence of screening. The authors emphasized that there is a subset of patients that should not be treated by radical prosta- tectomy which needs to be identified in the future,z There are further features of the PIVOT study making it appropriate to interpret the lack of survival differences in this trial with caution. With more than 30% dying of other causes by 10 years, the competing mortalityrate was three times as high as usually observed in contemporary radical prostatec- tomy series： 10%,4 4%-12%s and 11%.6 The PIVOT study sample obviously contained an over-proportionally large proportion of cases with a high risk of early competing mortality. This observation is particularly remarkable because it was associated with a mean age of only 67 years1 which was not unusually high. In very healthy men selected for radical pros- tatectomy, even in those aged 75 or more years, the competing mortality rate within I0 years after surgery may be narrowly zero.7 The low statistical power to detect poten- tial survival differences in the PIVOT trial has been emphasized,s It is, therefore, hardly possible to draw general conclusions from the outcome of the low-risk subgroup in the PIVOT trial. With the relatively short observation time, the small sample size and the high competing mortality rate, the lack of outcome differences is probably not suited to reassure younger and healthier patients with screen-detected prostate cancer. Cur- rently available prognostic markers are not able to predict the course of untreated pro- state cancer over decades of further life-span even if initially no high-risk features are pre- sent. The marked decrease of prostate cancer mortality in the United States since the intro- duction of （opportunistic） prostate-specific antigen-based screening illustrates that there is an effect of early treatment on prostate diagnosis and active cancer mortality, al- though randomized trials did not reveal unequivocal results so far.s-a It is rather the question whether the price in terms of over- diagnosis and quality of life impairment is reasonable than whether screening and active treatment are able to decrease prostate cancer mortality. The authors discussed several limitations of their study.2 The combination of data of different studies performed during different times in different health care systems （PIVOT and Scandinavian Prostate Cancer GroupStudy Number 4） is another potential limita- tion. It is conceivable that with a combined analysis of data also biases may be combined. In the PIVOT trial, only a small minority of initially screened patients （731 out of 13 022, i.e., 5.6%） have been eventually randomized. This figure may reflect the difficulty to recruit patients who agree to participate in such ran- domized trial and suggests a considerable selection process from screening to eventual trial enrollment. It is unknown in which degree this selection changed the composi- tion of the study sample and whether the remaining screen-detected cases were still representative. It is likely that the study sam- ple in this way was enriched by good risks. In the Scandinavian trial, a selection bias could be an explanation for the surprisingly diffe- rent efficacy of radical prostatectomy in men younger and older than 65 years11 that was in contrast to data from other studies. In a population-based cohort study that enrolled 14 516 conservatively treated patients with localized prostate cancer aged 65 years or older, the 10-year prostate cancer mortality rates did not differ after stratification by age and remained stabile even beyond an age of 80 years. 12 In the setting of the Scandinavian trial without a meaningful prevalence of pro- state-specific antigen screening, patients were probably more likely to contact their doctor with lower urinary tract symptoms. Since such symptoms more frequently occur in el- derly men, it is conceivable that a substantial proportion of prostate cancer in the elderly were diagnosed incidentally during workup for lower urinary tract symptoms which were not caused by the cancer itself, whereas in younger patients obstructive larger cancers which would do poorly with conservative treatment alone were more likely of being detected.11展开更多
A new,compact and exible low energy experimental platform of highly charged ions(HCIs)based on an electron beam ion source of the Dresden EBIS-A type is presented.The so-called IMP EBIS-A Facility of the Institute of ...A new,compact and exible low energy experimental platform of highly charged ions(HCIs)based on an electron beam ion source of the Dresden EBIS-A type is presented.The so-called IMP EBIS-A Facility of the Institute of Modern Physics(IMP)in Lanzhou is designed as a user facility for the state-resolved charge exchange studies in HCIs with atoms and molecules collisions by cold target recoil ion momentum spectroscopy(COLTRIMS).展开更多
This paper gives an introduction to the essential challenges of software engineering and requirements that software has to fulfill in the domain of automation. Besides, the functional characteristics, specific constra...This paper gives an introduction to the essential challenges of software engineering and requirements that software has to fulfill in the domain of automation. Besides, the functional characteristics, specific constraints and circumstances are considered for deriving requirements concerning usability, the technical process, the automation functions, used platform and the well-established models, which are described in detail. On the other hand, challenges result from the circumstances at different points in the single phases of the life cycle of the automated system. The requirements for life-cycle-management, tools and the changeability during runtime are described in detail.展开更多
An improved understanding of biodiversity-productivity relationships(BPRs)along environmental gradients is crucial for effective ecosystem management and biodiversity conservation.The stress-gradient hypothesis sugges...An improved understanding of biodiversity-productivity relationships(BPRs)along environmental gradients is crucial for effective ecosystem management and biodiversity conservation.The stress-gradient hypothesis suggests that BPRs are stronger in stressful environments compared to more favorable conditions.However,there is limited knowledge regarding the variation of BPRs along elevational gradients and their generality across different landscapes.To study how BPRs change with elevation,we harnessed inventory data on 6,431 trees from152 plots surveyed twice in eight to ten year intervals in mountain forests of temperate Europe and subtropical Asia.We quantified the relationship between aboveground productivity and different biodiversity measures,including taxonomic,functional,and phylogenetic diversity.To elucidate the processes underlying BPRs,we studied the variation of different functional traits along elevation across landscapes.We found no general pattern of BPRs across landscapes and elevations.Relationships were neutral for all biodiversity measures in temperate forests,and negative for taxonomic and functional diversity in subtropical forests.BPRs were largely congruent between taxonomic,functional and phylogenetic diversity.We found only weak support for the stress-gradient hypothesis,with BPRs turning from negative to positive(effect not significant)close to the tree line in subtropical forests.In temperate forests,however,elevation patterns were strongly modulated by species identity effects as influenced by specific traits.The effect of traits such as community-weighted mean of maximum plant height and wood density on productivity was congruent across landscapes.Our study highlights the context-dependence of BPRs across elevation gradients and landscapes.Species traits are key modulating factors of BPRs and should be considered more explicitly in studies of the functional role of biodiversity.Furthermore,our findings highlight that potential trade-offs between conserving biodiversity and fostering ecosystem productivity exist,which require more attention in policy and management.展开更多
Transforming nanoscale and bulk metals into single atoms is crucial for the scalable production of single-atom catalysts(SACs),especially during pyrolysis.However,conventional equilibrium heating approaches often requ...Transforming nanoscale and bulk metals into single atoms is crucial for the scalable production of single-atom catalysts(SACs),especially during pyrolysis.However,conventional equilibrium heating approaches often require prolonged operation to decompose metal aggregates,leading to tedious and time-consuming procedures for synthesizing SACs.In this study,we introduce high-temperature shock(HTS)strategy to enhance metal atomization,achieving the direct transformation of bulk copper foil into single atoms in just 0.5 s at 1700 K.The HTS-produced Cu catalyst demonstrates a high content of 0.54 wt.%,comparable to those achieved by commonly reported top-down strategies,indicating that the HTS method provides a compelling alternative for synthesizing Cu SACs from bulk Cu precursors.Structural analysis confirmed the synthesis of a Cu-N-C SAC with a Cu-N_(4) coordination environment.This Cu-N_(4) structure shows excellent catalytic performance for nitrite reduction to ammonia,achieving over 90% Faradaic efficiency across the entire working potential range and an ammonia production rate of up to 11.12 mg·cm^(-2)·h^(-1) at -1.2 V vs.reversible hydrogen electrode(RHE),surpassing other reported Cu-based electrocatalysts.Furthermore,ab initio molecular dynamics(AIMD)simulations reveal that transient high temperatures not only promote the formation of thermodynamically favorable Cu-N bonds but also prevent excessive sintering and aggregation of metal atoms.展开更多
Physical, chemical, and microbial properties of forest soils subjected to long-term fly ash depositions were analyzed in spruce (Picea abies (L.) Karst.) stands of eastern Germany on three forest sites along an emissi...Physical, chemical, and microbial properties of forest soils subjected to long-term fly ash depositions were analyzed in spruce (Picea abies (L.) Karst.) stands of eastern Germany on three forest sites along an emission gradient of 3 (high input), 6, and 15 km (low input) downwind of a coal-fired power plant. Past emissions resulted in an atypical high mass of mineral fly ash constituents in the organic horizons at the high input site of 128 t ha-1 compared to 58 t ha-1 at the low input site. Magnetic susceptibility measurements proved that the high mineral content of the forest floor was a result of fly ash accumulation in these forest stands. Fly ash deposition in the organic horizons at Site I versus III significantly increased the pH values, effective cation exchange capacity, base saturation and, with exception of the L horizon, concentrations of mobile heavy metals Cd, Cr, and Ni, while stocks of organic C generally decreased. A principal component analysis showed that organic C content and base status mainly controlled soil microbial biomass and microbial respiration rates at these sites, while pH and mobile fractions of Cd, Cr, and Ni governed enzyme activities. Additionally, it was hypothesized that long-term fly ash emissions would eventually destabilize forest ecosystems. Therefore, the results of this study could become a useful tool for risk assessment in forest ecosystems that were subjected to past emissions from coal-fired power plants.展开更多
MXenes add dozens of metallic conductors to the family of two-dimensional(2D)materials.A top-down synthesis approach removing A-layer atoms(e.g.,Al,Si,and Ga)in MAX phases to produce 2D flakes attaches various surface...MXenes add dozens of metallic conductors to the family of two-dimensional(2D)materials.A top-down synthesis approach removing A-layer atoms(e.g.,Al,Si,and Ga)in MAX phases to produce 2D flakes attaches various surface terminations to MXenes.With these terminations,MXenes show tunable properties,promising a range of applications from energy storage devices to electronics,including sensors,transistors,and antennas.MXenes are also excellent building blocks to create flexible films used for flexible and wearable devices.This article summarizes the synthesis of MXene flakes and highlights aspects that need attention for flexible devices.Rather than listing the development of energy storage devices in detail,we focus on the main challenges of and solutions for constructing high-performance devices.Moreover,we show the applications of MXene films in electronics to call on designs to construct a complete system based on MXene with good flexibility,which consists of a power source,sensors,transistors,and wireless communications.展开更多
文摘Previously, mouse bone marrow-derived stem cells （MSC） treated with the unspecific DNA methyltransferase inhibitor 5-azacytidine were reported to differentiate into cardiomyocytes. The aim of the present study was to investigate the efficiency of a similar differentiation strategy in human mononuclear cells obtained from healthy bone marrow donors. After 1-3 passages, cultures were exposed for 24 h to 5-azacytidine （3 μM） followed by 6 weeks of further culture. Drug treatment did not induce expression of myogenic marker MyoD or cardiac markers Nkx2.5 and GATA-4 and did not yield beating cells during follow-up. In patch clamp experiments, approximately 10-15% of treated and untreated cells exhibited L-type Ca^2＋ currents. Almost all cells showed outwardly rectifying K^＋ currents of rapid or slow activation kinetics. Mean current amplitude at ＋60 mV doubled after 6 weeks of treatment compared with time-matched controls. Membrane capacitance of treated cells was significantly larger than in controls 2 weeks after treatment and remained high after 6 weeks, Expression levels of mRNAs for the K^＋ channels Kv 1,1, Kv 1,5, Kv2,1, Kv4,3 and KCNMA 1 and for the Ca^2＋ channel Cav 1.2 were not affected by 5-azacytidine. Treatment with potassium channel blockers tetraethylammonium and clofilium at concentrations shown previously to inhibit rapid or slowly activating K^＋ currents of hMSC inhibited proliferation of these cells. Our results suggest that despite the absence of differentiation ofhMSC into cardiomyocytes, treatme.nt with 5-azacytidine caused profound changes in current density.
文摘When Aerodrome Obstacle Standards cannot be met as a result of urban or technical development, an aeronautical study can be carried out with the permission of EASA, in conjunction with ICAO, to prove how aircrafts can achieve an equivalent level of safety. However currently, no detailed guidance for this procedure exists. This paper proposes such a safety assessment methodology in order to value obstacle clearance violations around airports. This method has already been applied to a safety case at Frankfurt Airport where a tower elevating 4 km out of threshold 25R severely violates obstacle limitation surfaces. The model data refers to a take-off and landing performance model (TLPM) computing precisely aircraft trajectories for both standard and engine out conditions at ground proximity. The generated tracks are used to estimate collision risk incrementally considering EASA/FAA, EU-OPS & ICAO clearance criteria. Normal operations are assessed with a probabilistic analysis of empirical take-off/landing track data generating the local actual navigation performance (ANP) on site. The ANP shows integration to collision risk for an aircraft with any obstacle. The obstacle is tested for clearance within a “5-step-plan” against all performance requirements for landing climb and take-off climb. The methodology thereby delivers a comprehensive risk picture: The presented safety case for Frankfurt Airport showed an equivalent safety level despite the violation of standards. The collision risk during both normal and degraded performance operations was still found to be within ICAO Collision Risk Model (CRM) limits, requiring only limited risk mitigation measures. The presented work should complement ICAO Doc 9774 Appendix 3.
文摘Radical prostatectomy in elderly patients is controversial. To identify very old candidates for radical prostatectomy with the highest probability of long-term survival, we studied 47 consecutive men who underwent radical prostatectomy between 1992 and 2005 at an age of 75 years or older. A heuristic approach was used to search for subgroups with particularly high long-term survival. Several two-sided comorbidity measures and combinations of these measures were investigated to find classifications best identifying healthy, long-living elderly candidates for radical prostatectomy. Four of the 25 two-sided comorbidity classifications or combinations reached the significance level with hazard ratios between 4.00 and 4.80. After 10 years, patients identified as healthy patients according to these comorbidity measurements had exhibited relative survival rates between 129% and 137% and overall survival rates between 86% and 95%, whereas those with comorbidities had exhibited relative survival rates of only 66%-84% and overall survival rates of 44%-58%. In conclusion, classifying comorbidity may identify a meaningful proportion of men selected for radical prostatectomy at an age of 75 years or older with an excellent long-term survival probability superseding that of the general population.
文摘Causes, paths and interim results of the Arab Spring are discussed from the perspective of comparative revolutionary analysis. One has to distinguish revolutionary situations, with a multitude of conflict forms, from revolutionary outcomes. Also one should consider the options for development granted by different forms of political authority. Sultanist rule here allows for only highly limited perspectives. Such a form of political authority is focused only on the ruler and his entourage. There is no developing of encompassing and persistent institutions that would allow for smooth political change and the provision of public goods characteristic of democratic order. Numerous other theoretical elements are drawn on in assessing the chances of transformation and possible scenarios. Population pressures by an extremely young and mostly unemployed or underemployed population and the lack of a regional power are two of the crucial burdens. Further, one finds persistent cultural-religious cleavages The Arab monarchies from Morocco to Saudi-Arabia have reacted with very limited political concessions and welfare payments to buy off protest sentiments. Thus far they could avoid regime failure as occurred to the more Sultanist regimes in Libya and Syria. In the second portion of this manuscript the security implications of the failed Arab spring are addressed in regional and global terms.
文摘In a paper conceived about five years ago(“Globalization and Public Goods:Too Big to Tackle?”)roughly a dozen factors were linked to explain important causal paths from globalization to the potential output of public goods.The Russian invasion of Ukraine,the corona epidemic,and the increased hegemonic rivalry between China and the U.S.interrupted or even destroyed many of the linkages between globalization and potential public good production.About five important detrimental paths involved in the meantime.In the present article we aim at linking what is left from the previous level of globalization or emerging to form a new and simplified causal model for likely linkages between truncated or(re-)emerging globalization,and the deadly needed output of public goods.These linkages refer to rules of climate control,go to trade linkages and arbitrary tariffs and trade interventions.Regime change,regime formation,and alliance restructuring address aspects of domestic rule and international stability.Selectorate theory,regime type,and exit options for political elites provide key explanatory factors in explaining globalization and public goods productions,or their decay.Where possible we use some data and transformation experiences corroborating our arguments.In other instances need for further empirical macro research will become clear.
基金the National Natural Science Foundation of China （Project No.50473002）,and the Cultivation Fund of the Key Scientific and Technical Innovation Project, Ministry of Education of China （No.704021）. the National High-tech 863 Project （2002AA302616）, and the Shanghai Nano Special Projects （0452nm006, 05nm05005）.
文摘A series of clay/poly（N-isopropylacrylamide-co-acrylamide） nanocomposite hydrogels （S-N-M gels） have been successfully prepared by in situ polymerization. The mechanical properties, swelling behavior of S-N-M gels and the transparency changes during polymerization of S-N-M gels have been systematically investigated. Compared to traditional hydrogels, S-N-M gels show excellent tensile properties and their swelling ratio increases with increasing acrylamide （AAm） content. The results of stress relaxation indicate that the stress loss decreases with increasing AAm content. It was surprisingly found that the transparency during all S-N-M gel synthesis changes abruptly, and the changes become more abrupt with increasing N-isopropylacrylamide content. It was concluded that the fact may be related to the hydrophilicity of copolymers. The weaker the hydrophilicity of copolymer, the more apparent the transparency change during S-N-M gels polymerization. We believe the relationship between hydrophilicity of copolymer and transparency changes will help to design novel nanocomposite hydrogels.
文摘Compared to all other organs of the body the ratio pericyte per endothelial cell is very high in the retina. However, it is still unclear which local metabolic factor causes the feedback from retinal cells to adjust the capillary blood flow. Chen and Anderson (1997) could show that the effect of C02 on the intracellular pH and the contractility of pericytes was mediated primarily
文摘The generalized 2-D problem of a half-infinite interfacial electrode layer between two arbitrary piezoelectric half-spaces is studied. Based on the Stroh formalism, exact expressions for the (Green's) functions of a line force, a line charge and a line electric dipole applied at an arbitrary point near the electrode edge,were presented, respectively. The corresponding solutions for the intensity factors of fields were also obtained in an explicit form. These results can be used as the foundational solutions in boundary element method (BEM) to solve more complicated fracture problems of piezoelectric composites.
基金Project supported by the German Research Council, Germany (No. DFG Graduiertenkolleg 339).
文摘To evaluate the validity of different indices in estimating soil readily mineralizable N, soil microbial biomass （Nmic）, soil active N （SAN）, soluble organic N （SON）, net N mineralization rate （NNR） and gross N mineralization rate （GNR） in mineral soils （0-10 cm） from six forest stands located in central Germany were determined and compared with two sampling times： April and November. Additionally, soil density fractionation was conducted for incubated soils （with addition of ^15NH4-N and glucose, 40 days） to observe the sink of added ^15N in different soil fractions. The study showed that Nmic and NNR in most stands differed significantly （P 〈 0.05） between the two sampling times, but not GNR, SAN and SON. In November, no close relationships were found between GNR and other N indices, or between Nrnic, SON, and SAN and forest type. However, in April, GNR was significantly correlated （P 〈 0.05） with Nmic, SAN, and NNR along with Nmlc under beech being significantly higher （P 〈 0.05） than under conifers. Furthermore, density fractionation revealed that the light fraction （LF, 0.063-2 mm, 〉 1.7 gcm^-3） was not correlated with the other N indices. In contrast, results from the incubation study proved that more 15N was incorporated into the heavy fraction （HF 〈 0.063 ram, 〉 1.7 g cm^-3） than into LF, indicaing that more labile N existed in HF than in LF. These findings suggested that attention should be paid to the differences existing in N status between agricultural and forest soils.
文摘The technology of anaerobic digestion of sewage and solid wastes regains people＇s attention, mainly due to high price of fossil fuel nowadays in most recent years. The main topic for batch test is to study the inhibitory effect and boundary conditions of organic acid （propionic acid） to anaerobic digesters. High concentrations ofpropionic acid are achieved by direct dosage of the acid. As it is thought to be highly inhibitory to the digester, we are expecting that： （1） the production rate of methane declines and finally stops when the acid gradually accumulates; （2） the propionic acid will displace stronger inhibition under lower pH values. The results of the batch tests will assist engineers to better control anaerobic digesters and react to potential digester crises caused by propionic acid before it is too late.
文摘Continuously rising demands of legislators require a significant reduction of CO2-emission and thus fuel consumption across all vehicle classes. In this context, lightweight construction materials and designs become a single most important factor. The main engineering challenge is to precisely adapt the material and component properties to the specific load situation. However, metallic car body structures using “Tailored blanks” or “Patchwork structures” meet these requirements only insufficiently, especially for complex load situations (like crash). An innovative approach has been developed to use laser beams to locally strengthen steel crash structures used in vehicle bodies. The method tailors the workpiece hardness and thus strength at selected locations to adjust the material properties for the expected load distribution. As a result, free designable 3D-strengthening-patterns surrounded by softer base metal zones can be realized by high power laser beams at high processing speed. The paper gives an overview of the realizable process window for different laser treatment modes using current high brilliant laser types. Furthermore, an efficient calculation model for determining the laser track properties (depth/width and flow curve) is shown. Based on that information, simultaneous FE modelling can be efficiently performed. Chassis components are both statically and cyclically loaded. Especially for these components, a modulation of the fatigue behavior by laser-treated structures has been investigated. Simulation and experimental results of optimized crash and deep drawing components with up to 55% improved level of performance are also illustrated.
文摘I n a recently published study, the results of the Prostate Cancer Intervention ver-sus Observation Trial （PIVOT） trial were compared with that of the Scandinavian Prostate Cancer Group Study Number 4 （SPCG-4）. The authors concluded that the discrepancy of the mortality rates between both studies may be explained by screen- related lead time and over-diagnosis. In this comment, some potential biases are dis- cussed and the limited applicability of the results of both randomized trials to healthy candidates for radical prostatectomy is underlined. The results of the Prostate Cancer Inter- vention versus Observation Trial （PWOT）1 raised questions on the efficacy of radical prostatectomy in men with low-risk prostate cancer. Xia and co-workers2 used simulation modeling to determine whether the reduced absolute survival benefit in the PIVOT trial1 compared with Scandinavian Prostate Cancer Group Study Number 43 may be explained by the high prevalence of screen-detected prostate cancers in the PIVOT study. The authors concluded that the discrepancy of the mortality rates between both studies may largdy be explained by screen-rdated lead time and over-diagnosis and should not be considered as an argument against the efficacy of radical prostatectomy even in the presence of screening. The authors emphasized that there is a subset of patients that should not be treated by radical prosta- tectomy which needs to be identified in the future,z There are further features of the PIVOT study making it appropriate to interpret the lack of survival differences in this trial with caution. With more than 30% dying of other causes by 10 years, the competing mortalityrate was three times as high as usually observed in contemporary radical prostatec- tomy series： 10%,4 4%-12%s and 11%.6 The PIVOT study sample obviously contained an over-proportionally large proportion of cases with a high risk of early competing mortality. This observation is particularly remarkable because it was associated with a mean age of only 67 years1 which was not unusually high. In very healthy men selected for radical pros- tatectomy, even in those aged 75 or more years, the competing mortality rate within I0 years after surgery may be narrowly zero.7 The low statistical power to detect poten- tial survival differences in the PIVOT trial has been emphasized,s It is, therefore, hardly possible to draw general conclusions from the outcome of the low-risk subgroup in the PIVOT trial. With the relatively short observation time, the small sample size and the high competing mortality rate, the lack of outcome differences is probably not suited to reassure younger and healthier patients with screen-detected prostate cancer. Cur- rently available prognostic markers are not able to predict the course of untreated pro- state cancer over decades of further life-span even if initially no high-risk features are pre- sent. The marked decrease of prostate cancer mortality in the United States since the intro- duction of （opportunistic） prostate-specific antigen-based screening illustrates that there is an effect of early treatment on prostate diagnosis and active cancer mortality, al- though randomized trials did not reveal unequivocal results so far.s-a It is rather the question whether the price in terms of over- diagnosis and quality of life impairment is reasonable than whether screening and active treatment are able to decrease prostate cancer mortality. The authors discussed several limitations of their study.2 The combination of data of different studies performed during different times in different health care systems （PIVOT and Scandinavian Prostate Cancer GroupStudy Number 4） is another potential limita- tion. It is conceivable that with a combined analysis of data also biases may be combined. In the PIVOT trial, only a small minority of initially screened patients （731 out of 13 022, i.e., 5.6%） have been eventually randomized. This figure may reflect the difficulty to recruit patients who agree to participate in such ran- domized trial and suggests a considerable selection process from screening to eventual trial enrollment. It is unknown in which degree this selection changed the composi- tion of the study sample and whether the remaining screen-detected cases were still representative. It is likely that the study sam- ple in this way was enriched by good risks. In the Scandinavian trial, a selection bias could be an explanation for the surprisingly diffe- rent efficacy of radical prostatectomy in men younger and older than 65 years11 that was in contrast to data from other studies. In a population-based cohort study that enrolled 14 516 conservatively treated patients with localized prostate cancer aged 65 years or older, the 10-year prostate cancer mortality rates did not differ after stratification by age and remained stabile even beyond an age of 80 years. 12 In the setting of the Scandinavian trial without a meaningful prevalence of pro- state-specific antigen screening, patients were probably more likely to contact their doctor with lower urinary tract symptoms. Since such symptoms more frequently occur in el- derly men, it is conceivable that a substantial proportion of prostate cancer in the elderly were diagnosed incidentally during workup for lower urinary tract symptoms which were not caused by the cancer itself, whereas in younger patients obstructive larger cancers which would do poorly with conservative treatment alone were more likely of being detected.11
基金National Key R&D Program of China(2017YFA0402400,2017YFA0402300)National Natural Science Foundation of China(11274317)。
文摘A new,compact and exible low energy experimental platform of highly charged ions(HCIs)based on an electron beam ion source of the Dresden EBIS-A type is presented.The so-called IMP EBIS-A Facility of the Institute of Modern Physics(IMP)in Lanzhou is designed as a user facility for the state-resolved charge exchange studies in HCIs with atoms and molecules collisions by cold target recoil ion momentum spectroscopy(COLTRIMS).
文摘This paper gives an introduction to the essential challenges of software engineering and requirements that software has to fulfill in the domain of automation. Besides, the functional characteristics, specific constraints and circumstances are considered for deriving requirements concerning usability, the technical process, the automation functions, used platform and the well-established models, which are described in detail. On the other hand, challenges result from the circumstances at different points in the single phases of the life cycle of the automated system. The requirements for life-cycle-management, tools and the changeability during runtime are described in detail.
基金supported by the Sino-German Postdoc Scholarship Program of the China Scholarship Council(CSC)the German Academic Exchange Service(DAAD)+4 种基金supported in part by the National Natural Science Foundation of China(Nos.32071541,41971071)the Ministry of Science and Technology of China(Nos.2021FY100200,2021FY100702,2023YFF0805802)the Youth Innovation Promotion Association,CAS(No.2021392)the International Partnership Program,CAS(No.151853KYSB20190027)the“Climate Change Research Initiative of the Bavarian National Parks”funded by the Bavarian State Ministry of the Environment and Consumer Protection.
文摘An improved understanding of biodiversity-productivity relationships(BPRs)along environmental gradients is crucial for effective ecosystem management and biodiversity conservation.The stress-gradient hypothesis suggests that BPRs are stronger in stressful environments compared to more favorable conditions.However,there is limited knowledge regarding the variation of BPRs along elevational gradients and their generality across different landscapes.To study how BPRs change with elevation,we harnessed inventory data on 6,431 trees from152 plots surveyed twice in eight to ten year intervals in mountain forests of temperate Europe and subtropical Asia.We quantified the relationship between aboveground productivity and different biodiversity measures,including taxonomic,functional,and phylogenetic diversity.To elucidate the processes underlying BPRs,we studied the variation of different functional traits along elevation across landscapes.We found no general pattern of BPRs across landscapes and elevations.Relationships were neutral for all biodiversity measures in temperate forests,and negative for taxonomic and functional diversity in subtropical forests.BPRs were largely congruent between taxonomic,functional and phylogenetic diversity.We found only weak support for the stress-gradient hypothesis,with BPRs turning from negative to positive(effect not significant)close to the tree line in subtropical forests.In temperate forests,however,elevation patterns were strongly modulated by species identity effects as influenced by specific traits.The effect of traits such as community-weighted mean of maximum plant height and wood density on productivity was congruent across landscapes.Our study highlights the context-dependence of BPRs across elevation gradients and landscapes.Species traits are key modulating factors of BPRs and should be considered more explicitly in studies of the functional role of biodiversity.Furthermore,our findings highlight that potential trade-offs between conserving biodiversity and fostering ecosystem productivity exist,which require more attention in policy and management.
基金the National Natural Science Foundation of China(Nos.22222305,22402164,and 22021001)the Fundamental Research Funds for the Central Universities(No.20720220013).
文摘Transforming nanoscale and bulk metals into single atoms is crucial for the scalable production of single-atom catalysts(SACs),especially during pyrolysis.However,conventional equilibrium heating approaches often require prolonged operation to decompose metal aggregates,leading to tedious and time-consuming procedures for synthesizing SACs.In this study,we introduce high-temperature shock(HTS)strategy to enhance metal atomization,achieving the direct transformation of bulk copper foil into single atoms in just 0.5 s at 1700 K.The HTS-produced Cu catalyst demonstrates a high content of 0.54 wt.%,comparable to those achieved by commonly reported top-down strategies,indicating that the HTS method provides a compelling alternative for synthesizing Cu SACs from bulk Cu precursors.Structural analysis confirmed the synthesis of a Cu-N-C SAC with a Cu-N_(4) coordination environment.This Cu-N_(4) structure shows excellent catalytic performance for nitrite reduction to ammonia,achieving over 90% Faradaic efficiency across the entire working potential range and an ammonia production rate of up to 11.12 mg·cm^(-2)·h^(-1) at -1.2 V vs.reversible hydrogen electrode(RHE),surpassing other reported Cu-based electrocatalysts.Furthermore,ab initio molecular dynamics(AIMD)simulations reveal that transient high temperatures not only promote the formation of thermodynamically favorable Cu-N bonds but also prevent excessive sintering and aggregation of metal atoms.
基金Project financially supported by the Saxonian State Ministry of Sciences and Arts, Germany, by a fellowship supportfor the senior author
文摘Physical, chemical, and microbial properties of forest soils subjected to long-term fly ash depositions were analyzed in spruce (Picea abies (L.) Karst.) stands of eastern Germany on three forest sites along an emission gradient of 3 (high input), 6, and 15 km (low input) downwind of a coal-fired power plant. Past emissions resulted in an atypical high mass of mineral fly ash constituents in the organic horizons at the high input site of 128 t ha-1 compared to 58 t ha-1 at the low input site. Magnetic susceptibility measurements proved that the high mineral content of the forest floor was a result of fly ash accumulation in these forest stands. Fly ash deposition in the organic horizons at Site I versus III significantly increased the pH values, effective cation exchange capacity, base saturation and, with exception of the L horizon, concentrations of mobile heavy metals Cd, Cr, and Ni, while stocks of organic C generally decreased. A principal component analysis showed that organic C content and base status mainly controlled soil microbial biomass and microbial respiration rates at these sites, while pH and mobile fractions of Cd, Cr, and Ni governed enzyme activities. Additionally, it was hypothesized that long-term fly ash emissions would eventually destabilize forest ecosystems. Therefore, the results of this study could become a useful tool for risk assessment in forest ecosystems that were subjected to past emissions from coal-fired power plants.
基金National Natural Science Foundation of China,Grant/Award Number:52002247Deutsche Forschungsgemeinschaft,Grant/Award Number:ZH 989/2-1Natural Science Foundation of Guangdong Province,Grant/Award Number:2019A1515011344。
文摘MXenes add dozens of metallic conductors to the family of two-dimensional(2D)materials.A top-down synthesis approach removing A-layer atoms(e.g.,Al,Si,and Ga)in MAX phases to produce 2D flakes attaches various surface terminations to MXenes.With these terminations,MXenes show tunable properties,promising a range of applications from energy storage devices to electronics,including sensors,transistors,and antennas.MXenes are also excellent building blocks to create flexible films used for flexible and wearable devices.This article summarizes the synthesis of MXene flakes and highlights aspects that need attention for flexible devices.Rather than listing the development of energy storage devices in detail,we focus on the main challenges of and solutions for constructing high-performance devices.Moreover,we show the applications of MXene films in electronics to call on designs to construct a complete system based on MXene with good flexibility,which consists of a power source,sensors,transistors,and wireless communications.
