Photo-Rechargeable Asymmetric Supercapacitors Exceeding Light-to-Charge Storage Efficiency over 21% under Indoor Light.

Photo-rechargeable energy storage devices are appealing for substantial research attention because of their possible applications in the Internet of Things (IoT) and low-powered miniaturized portable electronics. However, due to the incompatibility of the photovoltaics and energy storage systems (ESSs), the overall light-to-storage efficiency is limited under indoor light conditions. Herein, a porous carbon scaffold MnO-Mn3 O4 /C microsphere-based monolithic dye-sensitized photo-rechargeable asymmetric supercapacitor (DSPC) is fabricated. The integrated DSPC has a high areal specific capacitance of 281.9 mF cm-2 at the discharge rate of 0.01 mA cm-2 . The light-to-electrical conversion efficiency of the DSSC is 27.6% under the 1000 lux compact fluorescent lamp (CFL). The DSPC shows an outstanding light-to-charge storage efficiency of 21.6%, which is higher than that reported ever. Furthermore, the fabricated polymer gel electrolyte-based quasi-solid state (QSS) DSPC shows similar overall conversion efficiency with superior cycling capability. This work shows a convenient fabrication process for a wireless power pack of interest with outstanding performance.

Achieving Fast and Stable Sodium Storage in Na4Fe3(PO4)2(P2O7) via Entropy Engineering.

Na4Fe3(PO4)2(P2O7) (NFPP) has been considered a promising cathode material for sodium-ion batteries (SIBs) owing to its environmental friendliness and economic viability. However, its electrochemical performance is constrained by connatural low electronic conductivity and inadequate sodium ion diffusion. Herein, a high-entropy substitution strategy is employed in NFPP to address these limitations. Ex situ X-ray diffraction analysis reveals a single-phase electrochemical reaction during the sodiation/desodiation processes and the increased configurational entropy in HE-NFPP endows an enhanced structure, which results in a minimal volume variation of only 1.83%. Kinetic analysis and density functional theory calculation further confirm that the orbital hybrid synergy of high-entropy transition metals offers a favorable electronic structure, which efficaciously boosts the charge transfer kinetics and optimizes the sodium ion diffusion channel. Based on this versatile strategy, the as-prepared high-entropy Na4Fe2.5Mn0.1Mg0.1Co0.1Ni0.1Cu0.1(PO4)2(P2O7) (HE-NFPP) cathode can deliver a prominent rate performance of 55 mAh g-1 at 10 A g-1 and an ultra-long cycling lifespan of over 18 000 cycles at 5 A g-1. When paired with a hard carbon (HC) anode, HE-NFPP//HC full cell exhibits a favorable cycling durability of 1000 cycles. This high-entropy engineering offers a feasible route to improve the electrochemical performance of NFPP and provides a blueprint for exploring high-performance SIBs.

DNN-PNN: A parallel deep neural network model to improve anticancer drug sensitivity.

With the rapid development of deep learning techniques and large-scale genomics database, it is of great potential to apply deep learning to the prediction task of anticancer drug sensitivity, which can effectively improve the identification efficiency and accuracy of therapeutic biomarkers. In this study, we propose a parallel deep learning framework DNN-PNN, which integrates rich and heterogeneous information from gene expression and pharmaceutical chemical structure data. With the proposal of DNN-PNN, a new and more effective drug data representation strategy is introduced, that is, the correlation between features is represented by product, which alleviates the limitations of high-dimensional discrete data in deep learning. Furthermore, the framework is optimized to reduce the time complexity of the model. We conducted extensive experiments on the CCLE datasets to compare DNN-PNN with its variant DNN-FM representing the traditional feature correlation model, the component DNN or PNN alone, and the common machine learning models. It is found that DNN-PNN not only has high prediction accuracy, but also has significant advantages in stability and convergence speed.

Impact of COVID-19 on Academic Burnout among Medical College Students in China: Findings from a Web-Based Survey.

BACKGROUND Academic burnout can affect students' academic behavior and performance and especially damages the careers of medical college students. Medical education systems during the COVID-19 pandemic have met unprecedented challenges that have influenced medical students. This study aimed to explore the effects of psychological resilience, stress, and smartphone addiction on academic burnout among Chinese medical students. MATERIAL AND METHODS This study utilized a cross-sectional design, from March 13, 2022 to March 31, 2022, within the Wannan Medical College, where students completed a web-based survey. The Chinese version of the Academic Burnout Scale (ABS), the 10-item Smartphone Addiction Scale-Short Version (SAS-SV), the Connor-Davidson Resilience Scale (CD-RISC 10) and the Perceived Stress Scale (PSS-4) were used in this survey. Data entry and analysis were conducted using IBM SPSS ver. 22.0. Pearson's correlation coefficient (r) was used to examine the correlations between medical college students' academic burnout and smartphone addiction and mental health. Binary logistic regression analysis was carried out to evaluate the factors influencing academic burnout. RESULTS Of 3190 medical college students who completed the survey, 1521 (47.7%) had some degree of academic burnout. Gender, being a student leader, grades, perceived stress, and smartphone addiction were associated with the total score of academic burnout. Psychological resilience and adapting to online classes were protective factors against academic burnout. CONCLUSIONS Academic burnout is common among medical college students in China after the COVID-19 pandemic, and it is urgent to address this situation to improve the quality of medical education.

Characterization of an autonomous pathway complex that promotes flowering in Arabidopsis.

Although previous studies have identified several autonomous pathway components that are required for the promotion of flowering, little is known about how these components cooperate. Here, we identified an autonomous pathway complex (AuPC) containing both known components (FLD, LD and SDG26) and previously unknown components (EFL2, EFL4 and APRF1). Loss-of-function mutations of all of these components result in increased FLC expression and delayed flowering. The delayed-flowering phenotype is independent of photoperiod and can be overcome by vernalization, confirming that the complex specifically functions in the autonomous pathway. Chromatin immunoprecipitation combined with sequencing indicated that, in the AuPC mutants, the histone modifications (H3Ac, H3K4me3 and H3K36me3) associated with transcriptional activation are increased, and the histone modification (H3K27me3) associated with transcriptional repression is reduced, suggesting that the AuPC suppresses FLC expression at least partially by regulating these histone modifications. Moreover, we found that the AuPC component SDG26 associates with FLC chromatin via a previously uncharacterized DNA-binding domain and regulates FLC expression and flowering time independently of its histone methyltransferase activity. Together, these results provide a framework for understanding the molecular mechanism by which the autonomous pathway regulates flowering time.

A novel function by cathepsin D in degradation of nucleic acids.

Cathepsin D (CTSD) is an aspartic endopeptidase, however, we found that it was also capable of enzymatic digestion of nucleic acids (NAs). The purpose of this study was to investigate the basic properties of CTSD enzymatic activity on NAs, and explore the degradation mechanism. The results showed that NAs were efficiently digested between pH 3.0 and 5.0, and the optimum pH was 3.5. CTSD exhibited optimum activity at the temperature of 50°C. The degradation rate was improved with an increased CTSD concentration, and NAs were digested to an enzyme concentration of 0.001%, at which point, NAs were no longer digested. Ca2+ and Mg2+ at low concentrations of 5 mM promoted the digestion remarkably. As the protein substrate for CTSD, both Hb and BSA had no effect on DNA degradation, even when the molar ratio of protein:DNA was 104:1. Kinetic parameters of Km and kcat/Km value were (42 ± 1) µM and (1.62 ± 0.1) × 10-2 s-1mM-1 respectively, using real-time quantitative PCR (RT-PCR). Specially, pepstatin A which is the specific aspartic protease inhibitor exhibited inhibitory effect on NA digestion by CTSD as well, suggesting that the catalytic active site of CTSD for NAs might be the same as protein. A brief degradation mechanism is discussed. The present study may change the cognition of CTSD specificity for substrate and contribute greatly to enzymology of CTSD.

Optimal coordination and reorganization of photosynthetic properties in C4 grasses.

Each of >20 independent evolutions of C4 photosynthesis in grasses required reorganization of the Calvin-Benson-cycle (CB-cycle) within the leaf, along with coordination of C4 -cycle enzymes with the CB-cycle to maximize CO2 assimilation. Considering the vast amount of time over which C4 evolved, we hypothesized (i) trait divergences exist within and across lineages with both C4 and closely related C3 grasses, (ii) trends in traits after C4 evolution yield the optimization of C4 through time, and (iii) the presence/absence of trends in coordination between the CB-cycle and C4 -cycle provides information on the strength of selection. To address these hypotheses, we used a combination of optimality modelling, physiological measurements and phylogenetic-comparative-analysis. Photosynthesis was optimized after the evolution of C4 causing diversification in maximal assimilation, electron transport, Rubisco carboxylation, phosphoenolpyruvate carboxylase and chlorophyll within C4 lineages. Both theory and measurements indicated a higher light-reaction to CB-cycle ratio (Jatpmax /Vcmax ) in C4 than C3 . There were no evolutionary trends with photosynthetic coordination between the CB-cycle, light reactions and the C4 -cycle, suggesting strong initial selection for coordination. The coordination of CB-C4 -cycles (Vpmax /Vcmax ) was optimal for CO2 of 200 ppm, not to current conditions. Our model indicated that a higher than optimal Vpmax /Vcmax affects assimilation minimally, thus lessening recent selection to decrease Vpmax /Vcmax .

Multifunctional amorphous FeCoNiTixSi high-entropy alloys with excellent electromagnetic-wave absorption performances.

Amorphous high-entropy alloys (HEAs) as electromagnetic-wave absorbing materials have been rarely reported. In this work, amorphous FeCoNiTixSi HEAs were synthesized by introducing a high content of large-atom Ti using the high-energy ball-milling technique. This amorphous structure could improve the saturated magnetization and coercivity of HEAs, but slightly degraded the mechanical and oxidation resistance properties. In terms of electromagnetic properties, FeCoNiTi0.01Si and FeCoNiTiSi exhibit excellent electromagnetic-wave absorption performances, with significant absorptions of -68.4 dB at 6.14 GHz and -63.4 dB at 9.12 GHz, corresponding to bandwidths of 5.15 GHz (1.69 mm) and 3.64 GHz (1.43 mm), respectively. Overall, the prepared FeCoNiTixSi HEAs exhibited superior comprehensive performances compared to other HEA absorption materials. This work provided a novel strategy for the development of new electromagnetic-wave absorption materials with low weight, high absorption efficiency, and resistance to harsh environments.

[Effects of post-traumatic stress disorder on the excitability of glutamatergic and GABAergic neurons in dorsal and ventral hippocampus in mice].

The purpose of this study was to investigate the effects of post-traumatic stress disorder (PTSD) on electrophysiological characteristics of glutamatergic and GABAergic neurons in dorsal hippocampus (dHPC) and ventral hippocampus (vHPC) in mice, and to elucidate the mechanisms underlying the plasticity of hippocampal neurons and memory regulation after PTSD. Male C57Thy1-YFP/GAD67-GFP mice were randomly divided into PTSD group and control group. Unavoidable foot shock (FS) was applied to establish PTSD model. The spatial learning ability was explored by water maze test, and the changes in electrophysiological characteristics of glutamatergic and GABAergic neurons in dHPC and vHPC were examined using whole-cell recording method. The results showed that FS significantly reduced the movement speed, and enhanced the number and percentage of freezing. PTSD significantly prolonged the escape latency in localization avoidance training, shortened the swimming time in the original quadrant, extended the swimming time in the contralateral quadrant, and increased absolute refractory period, energy barrier and inter-spike interval of glutamatergic neurons in dHPC and GABAergic neurons in vHPC, while decreased absolute refractory period, energy barrier and inter-spike interval of GABAergic neurons in dHPC and glutamatergic neurons in vHPC. These results suggest that PTSD can damage spatial perception of mice, down-regulate the excitability of dHPC and up-regulate the excitability of vHPC, and the underlying mechanism may involve the regulation of spatial memory by the plasticity of neurons in dHPC and vHPC.

Integration of a pure moving bed biofilm reactor process into a large micro-polluted water treatment plant.

The pure-MBBR process was applied to remove ammonia in a full-scale micro-polluted-water treatment plant with a daily treatment capacity of 260 × 104 m3/d, Guangdong, China. The relationship between treatment efficiency, physical and chemical properties and microbial diversity in the process of biofilm growth was explored, and the oxygen transfer model of biofilm was established. The results show that the effluent of two-stage pure MBBR process is stable and up to standard after 10 days' incubation. The nitrification loads of two-stage biofilm was stable on the 14th day. The biomass and biofilm thickness lagged behind the nitrification load, and reached a relatively stable level on the 28th day. The species richness of biofilm basically reached a stable level on the 21st day, and the microbial diversity of primary biofilm was higher. In the primary and secondary stage at different periods, the relative abundance of dominant nitrifying bacteria Nitrospira reaches 8.48-13.60%, 6.48-9.27%, and Nitrosomonas reaches 2.89-5.64%, 0.00-3.48%. The pure MBBR system mainly adopts perforated aeration. Through the cutting and blocking of bubbles by suspended carriers, the oxygen transfer rate of the system was greatly improved.

PRPI-SC: an ensemble deep learning model for predicting plant lncRNA-protein interactions.

BACKGROUND: Plant long non-coding RNAs (lncRNAs) play vital roles in many biological processes mainly through interactions with RNA-binding protein (RBP). To understand the function of lncRNAs, a fundamental method is to identify which types of proteins interact with the lncRNAs. However, the models or rules of interactions are a major challenge when calculating and estimating the types of RBP. RESULTS: In this study, we propose an ensemble deep learning model to predict plant lncRNA-protein interactions using stacked denoising autoencoder and convolutional neural network based on sequence and structural information, named PRPI-SC. PRPI-SC predicts interactions between lncRNAs and proteins based on the k-mer features of RNAs and proteins. Experiments proved good results on Arabidopsis thaliana and Zea mays datasets (ATH948 and ZEA22133). The accuracy rates of ATH948 and ZEA22133 datasets were 88.9% and 82.6%, respectively. PRPI-SC also performed well on some public RNA protein interaction datasets. CONCLUSIONS: PRPI-SC accurately predicts the interaction between plant lncRNA and protein, which plays a guiding role in studying the function and expression of plant lncRNA. At the same time, PRPI-SC has a strong generalization ability and good prediction effect for non-plant data.

The CCR4-NOT complex component NOT1 regulates RNA-directed DNA methylation and transcriptional silencing by facilitating Pol IV-dependent siRNA production.

Small interfering RNAs (siRNAs) are responsible for establishing and maintaining DNA methylation through the RNA-directed DNA methylation (RdDM) pathway in plants. Although siRNA biogenesis is well known, it is relatively unclear about how the process is regulated. By a forward genetic screen in Arabidopsis thaliana, we identified a mutant defective in NOT1 and demonstrated that NOT1 is required for transcriptional silencing at RdDM target genomic loci. We demonstrated that NOT1 is required for Pol IV-dependent siRNA accumulation and DNA methylation at a subset of RdDM target genomic loci. Furthermore, we revealed that NOT1 is a constituent of a multi-subunit CCR4-NOT deadenylase complex by immunoprecipitation combined with mass spectrometry and demonstrated that the CCR4-NOT components can function as a whole to mediate chromatin silencing. Therefore, our work establishes that the CCR4-NOT complex regulates the biogenesis of Pol IV-dependent siRNAs, and hence facilitates DNA methylation and transcriptional silencing in Arabidopsis.

Steroid receptor coactivator-1 enhances the stemness of glioblastoma by activating long noncoding RNA XIST/miR-152/KLF4 pathway.

Glioblastoma (GBM) recurrence is attributed to the presence of therapy-resistant glioblastoma stem cells. Steroid receptor coactivator-1 (SRC-1) acts as an oncogenic regulator in many human tumors. The relationship between SRC-1 and GBM has not yet been studied. Herein, we investigate the role of SRC-1 in GBM. In this study, we found that SRC-1 expression is positively correlated with grades of glioma and inversely correlated with glioma patient's prognosis. Steroid receptor coactivator-1 promotes the proliferation, migration, and tumor growth of GBM cells. Notably, SRC-1 knockdown suppresses the stemness of GBM cells. Mechanistically, long noncoding RNA X-inactive specific transcript (XIST) is regulated by SRC-1 at the posttranscriptional level and mediates the function of SRC-1 in promoting stemness-like properties of GBM. Steroid receptor coactivator-1 can promote the expression of Kruppel-like factor 4 (KLF4) through the XIST/microRNA (miR)-152 axis. Additionally, arenobufagin and bufalin, SRC small molecule inhibitors, can reduce the proliferation and stemness of GBM cells. This study reveals SRC-1 promotes the stemness of GBM by activating the long noncoding RNA XIST/miR-152/KLF4 pathway and provides novel markers for diagnosis and therapy of GBM.

Plasmonic metamaterial absorbers with strong coupling effects for small pixel infrared detectors.

Here we report a metal-insulator-metal (MIM) based infrared plasmonic metamaterial absorber consisting of deep subwavelength meander line nanoantennas. High absorption composed of two-hybrid modes from 11 µm to 14 µm is experimentally demonstrated with a pixel pitch of 1.47 µm corresponding to a compression ratio of 8.57. The physical mechanisms responsible for novelty spectral absorption, including the strong coupling between the plasmon resonances and the phonon vibrations, material loss from the dielectric spacer, localized surface plasmon resonance (LSPR), and Berreman mode excited by oblique incidence, have been systematically analyzed by finite-difference time-domain (FDTD) method, Fabry-Perot resonance model and two-coupled damped oscillator model. At oblique incidence, a spectral splitting related to the strong coupling between LSPR mode and Berreman mode is also observed. The distribution of local electromagnetic fields and ohmic loss are numerically investigated. Moreover, we evaluate the absorption performances with finite-sized arrays. We also show that the absorber can maintain its absorption with a 2 × 2 nanoantenna array. Such a miniaturized absorber can adapt to infrared focal plane arrays with a pixel size smaller than 5 µm, and thermal analysis is also performed. Our approach provides an effective way to minimize the antenna footprint without undermining the absorber performances, paving the way towards its integration with small pixels of infrared focal plane arrays for enhanced performances and expanded functionalities.

Exposure to polychlorinated biphenyls and organochlorine pesticides and thyroid cancer in connecticut women.

BACKGROUND: Thyroid cancer incidence has increased substantially over the past decades, and environmental risk factors have been suggested to play a role. Polychlorinated biphenyls (PCB) and organochlorine pesticides (OCP) are established thyroid hormone disruptors, but their relationship to thyroid cancer is not known. METHODS: We investigated the relationship between serum PCB and OCP concentrations and papillary thyroid cancer (PTC) in 250 incident female PTC cases and 250 female controls frequency-matched on age, all residing in Connecticut. Interviews and serum samples were collected from 2010 to 2013. Samples were analyzed for 32 different chemicals using gas chromatography with isotope dilution high resolution mass spectrometry. We calculated odds ratios (OR) and 95% confidence intervals (CI) using single pollutant logistic regression models for concentrations (per interquartile range) of individual PCB/OCP and summed groups of structurally or biologically similar PCB/OCP, adjusted for education, family history of cancer, alcohol consumption, age, and body mass index. Sub-analyses included stratification by tumor size (≤ and >1 cm) and birth before or during peak PCB production (born in 1960 or earlier and born after 1960), as exposures during early life may be important. We also applied three multi-pollutant approaches (standard multi-pollutant regression, hierarchical Bayesian modeling, principal components regression analysis) to investigate associations with co-exposures to multiple PCB/OCPs. RESULTS: No PCB/OCPs were positively associated with PTC in primary analyses. Statistically significant associations were observed for 9 of the 32 chemicals and 3 summed groups of similar chemicals in the those born during peak production based on single-pollutant models. Multi-pollutant analyses suggested null associations overall. CONCLUSIONS: Our results using single and multi-pollutant modeling do not generally support an association between PCB or OCP exposure and PTC, but some associations in those born during peak production suggest that additional investigation into early-life exposures and subsequent thyroid cancer risk may be warranted.

C4 photosynthesis and climate through the lens of optimality.

CO2, temperature, water availability, and light intensity were all potential selective pressures that determined the competitive advantage and expansion of the C4 photosynthetic carbon-concentrating mechanism over the last ∼30 My. To tease apart how selective pressures varied along the ecological trajectory of C4 expansion and dominance, we coupled hydraulics to photosynthesis models while optimizing photosynthesis over stomatal resistance and leaf/fine-root allocation. We further examined the importance of nitrogen reallocation from the dark to the light reactions. We show here that the primary selective pressures favoring C4 dominance changed through the course of C4 evolution. The higher stomatal resistance and leaf-to-root ratios enabled by C4 led to an advantage without any initial difference in hydraulic properties. We further predict a reorganization of the hydraulic system leading to higher turgor-loss points and possibly lower hydraulic conductance. Selection on nitrogen reallocation varied with CO2 concentration. Through paleoclimate model simulations, we find that water limitation was the primary driver for a C4 advantage, with atmospheric CO2 as high as 600 ppm, thus confirming molecular-based estimates for C4 evolution in the Oligocene. Under these high-CO2 conditions, nitrogen reallocation was necessary. Low CO2 and high light, but not nitrogen reallocation, were the primary drivers for the mid- to late-Miocene global expansion of C4 We also predicted the timing and spatial distribution for origins of C4 ecological dominance. The predicted origins are broadly consistent with prior estimates, but expand upon them to include a center of origin in northwest Africa and a Miocene-long origin in Australia.

Predictors of Delayed Emergency Department Throughput Among Blunt Trauma Patients.

BACKGROUND: Delayed emergency department (ED) LOS has been associated with increased mortality and increased hospital length of stay (LOS) for various patient populations. Trauma patients often require significant effort in evaluation, workup, and disposition; however, patient and hospital characteristics associated with increased LOS in the ED for trauma patients remain unclear. METHODS: The Trauma Quality Improvement Project database (2014-2016) was queried for all adult blunt trauma patients. Patients discharged from the ED to the operating room were excluded. Univariate and multivariable linear regression analysis was conducted to identify independent predictors of ED LOS, controlling for patient characteristics (age, gender, race, insurance status), hospital characteristics (teaching status, ACS trauma verification level, geographic region), abbreviated injury scale and comorbid status. RESULTS: 412,000 patients met inclusion criteria for analysis. When controlling for covariates, an increase in age by 1 y resulted in 0.63 increased minutes in the ED (P < 0.001). In multivariable linear regression controlling for injury severity and comorbid conditions, non-white race groups, university status, and northeast region were associated with increased ED LOS. Black and Hispanic patients spent on average 41 and 42 more minutes, respectively, in the ED room when compared with white patients (P < 0.001). Patients seen at University hospitals spent 52 more minutes in the ED when compared with community hospitals, whereas patients at nonteaching hospitals spent 31 fewer minutes (P < 0.001). Patients seen in the Midwest spent the least amount of time in the ED, with patients in the South, West, and Northeast spending 45, 36, and 89 more minutes, respectively (P < 0.001). Non-Medicaid patients at level 1 trauma centers and those requiring intensive care admission had significantly decreased ED LOS. Medicaid patients took the longest to move through the ED with Medicare, BlueCross, and Private insurance outpacing them by 17, 23, and 23 min, respectively (P < 0.001). ACS level 1 trauma centers moved patients through the ED fastest, whereas ACS level II trauma centers and level III trauma centers moved patients through 50 and 130 min slower when compared with ACS level 1 trauma centers (P < 0.001). CONCLUSIONS: ED LOS varied significantly by patient and hospital characteristics. Medicaid patients and those patients at university hospitals were associated with significantly higher ED LOS, whereas ACS trauma verification level status had strong correlation with ED LOS. These results may allow targeted quality improvement programs to enhance ED LOS.

Aqp-1 Gene Knockout Attenuates Hypoxic Pulmonary Hypertension of Mice.

Objective- Hypoxic pulmonary hypertension (HPH) is characterized by proliferative vascular remodeling. Abnormal pulmonary artery smooth muscle cells proliferation and endothelial dysfunction are the primary cellular bases of vascular remodeling. AQP1 (aquaporin-1) is regulated by oxygen level and has been observed to play a role in the proliferation and migration of pulmonary artery smooth muscle cells. The role of AQP1 in HPH pathogenesis has not been directly determined to date. To determine the possible roles of AQP1 in the pathogenesis of HPH and explore its possible mechanisms. Approach and Results- Aqp1 knockout mice were used, and HPH model was established in this study. Primary pulmonary artery smooth muscle cells, primary mouse lung endothelial cells, and lung tissue sections from HPH model were used. Immunohistochemistry, immunofluorescence and Western blot, cell cycle, apoptosis, and migration analysis were performed in this study. AQP1 expression was upregulated by chronic hypoxia exposure, both in pulmonary artery endothelia and medial smooth muscle layer of mice. Aqp1 deficiency attenuated the elevation of right ventricular systolic pressures and mitigated pulmonary vascular structure remodeling. AQP1 deletion reduced abnormal cell proliferation in pulmonary artery and accompanied with accumulation of HIF (hypoxia-inducible factor). In vitro, Aqp1 deletion reduced hypoxia-induced proliferation, apoptosis resistance, and migration ability of primary cultured pulmonary artery smooth muscle cells and repressed HIF-1α protein stability. Furthermore, Aqp1 deficiency protected lung endothelial cells from apoptosis in response to hypoxic injury. Conclusions- Our data showed that Aqp1 deficiency could attenuate hypoxia-induced vascular remodeling in the development of HPH. AQP1 may be a potential target for pulmonary hypertension treatment.

Elevated CO2 concentration induces photosynthetic down-regulation with changes in leaf structure, non-structural carbohydrates and nitrogen content of soybean.

BACKGROUND: Understanding the mechanisms of crops in response to elevated CO2 concentrations is pivotal to estimating the impacts of climate change on the global agricultural production. Based on earlier results of the "doubling-CO2 concentration" experiments, many current climate models may overestimate the CO2 fertilization effect on crops, and meanwhile, underestimate the potential impacts of future climate change on global agriculture ecosystem when the atmospheric CO2 concentration goes beyond the optimal levels for crop growth. RESULTS: This study examined the photosynthetic response of soybean (Glycine max (L.) Merr.) to elevated CO2 concentration associated with changes in leaf structure, non-structural carbohydrates and nitrogen content with environmental growth chambers where the CO2 concentration was controlled at 400, 600, 800, 1000, 1200, 1400, 1600 ppm. We found CO2-induced down-regulation of leaf photosynthesis as evidenced by the consistently declined leaf net photosynthetic rate (An) with elevated CO2 concentrations. This down-regulation of leaf photosynthesis was evident in biochemical and photochemical processes since the maximum carboxylation rate (Vcmax) and the maximum electron transport rate (Jmax) were dramatically decreased at higher CO2 concentrations exceeding their optimal values of about 600 ppm and 400 ppm, respectively. Moreover, the down-regulation of leaf photosynthesis at high CO2 concentration was partially attributed to the reduced stomatal conductance (Gs) as demonstrated by the declines in stomatal density and stomatal area as well as the changes in the spatial distribution pattern of stomata. In addition, the smaller total mesophyll size (palisade and spongy tissues) and the lower nitrogen availability may also contribute to the down-regulation of leaf photosynthesis when soybean subjected to high CO2 concentration environment. CONCLUSIONS: Down-regulation of leaf photosynthesis associated with the changes in stomatal traits, mesophyll tissue size, non-structural carbohydrates, and nitrogen availability of soybean in response to future high atmospheric CO2 concentration and climate change.

Estimating C4 photosynthesis parameters by fitting intensive A/Ci curves.

Measurements of photosynthetic assimilation rate as a function of intercellular CO2 (A/Ci curves) are widely used to estimate photosynthetic parameters for C3 species, yet few parameters have been reported for C4 plants, because of a lack of estimation methods. Here, we extend the framework of widely used estimation methods for C3 plants to build estimation tools by exclusively fitting intensive A/Ci curves (6-8 more sampling points) for C4 using three versions of photosynthesis models with different assumptions about carbonic anhydrase processes and ATP distribution. We use simulation analysis, out of sample tests, existing in vitro measurements and chlorophyll-fluorescence measurements to validate the new estimation methods. Of the five/six photosynthetic parameters obtained, sensitivity analyses show that maximal-Rubisco-carboxylation-rate, electron-transport-rate, maximal-PEP-carboxylation-rate, and carbonic-anhydrase were robust to variation in the input parameters, while day respiration and mesophyll conductance varied. Our method provides a way to estimate carbonic anhydrase activity, a new parameter, from A/Ci curves, yet also shows that models that do not explicitly consider carbonic anhydrase yield approximate results. The two photosynthesis models, differing in whether ATP could freely transport between RuBP and PEP regeneration processes yielded consistent results under high light, but they may diverge under low light intensities. Modeling results show selection for Rubisco of low specificity and high catalytic rate, low leakage of bundle sheath, and high PEPC affinity, which may further increase C4 efficiency.