bluuebunny/crossref_metadata_2025_split huggingface dataset:
Water use efficiency of China’s terrestrial ecosystems and responses to drought
Authors: Liu Yibo , Xiao Jingfeng , Ju Weimin , Zhou Yanlian , Wang Shaoqiang , Wu Xiaocui 
Published: September 2015

AbstractWater use efficiency (WUE) measures the trade-off between carbon gain and water loss of terrestrial ecosystems and better understanding its dynamics and controlling factors is essential for predicting ecosystem responses to climate change. We assessed the magnitude, spatial patterns and trends of WUE of China’s terrestrial ecosystems and its responses to drought using a process-based ecosystem model. During the period from 2000 to 2011, the national average annual WUE (net primary productivity (NPP)/evapotranspiration (ET)) of China was 0.79 g C kg−1 H2O. Annual WUE decreased in the southern regions because of the decrease in NPP and the increase in ET and increased in most northern regions mainly because of the increase in NPP. Droughts usually increased annual WUE in Northeast China and central Inner Mongolia but decreased annual WUE in central China. “Turning-points” were observed for southern China where moderate and extreme droughts reduced annual WUE and severe drought slightly increased annual WUE. The cumulative lagged effect of drought on monthly WUE varied by region. Our findings have implications for ecosystem management and climate policy making. WUE is expected to continue to change under future climate change particularly as drought is projected to increase in both frequency and severity.
Pelagic photoferrotrophy and iron cycling in a modern ferruginous basin
Authors: Llirós Marc , García–Armisen Tamara , Darchambeau François , Morana Cédric , Triadó–Margarit Xavier , Inceoğlu Özgül , Borrego Carles M. , Bouillon Steven , Servais Pierre , Borges Alberto V. , Descy Jean–Pierre , Canfield Don E. , Crowe Sean A. 
Published: September 2015

AbstractIron-rich (ferruginous) ocean chemistry prevailed throughout most of Earth’s early history. Before the evolution and proliferation of oxygenic photosynthesis, biological production in the ferruginous oceans was likely driven by photoferrotrophic bacteria that oxidize ferrous iron {Fe(II)} to harness energy from sunlight and fix inorganic carbon into biomass. Photoferrotrophs may thus have fuelled Earth’s early biosphere providing energy to drive microbial growth and evolution over billions of years. Yet, photoferrotrophic activity has remained largely elusive on the modern Earth, leaving models for early biological production untested and imperative ecological context for the evolution of life missing. Here, we show that an active community of pelagic photoferrotrophs comprises up to 30% of the total microbial community in illuminated ferruginous waters of Kabuno Bay (KB), East Africa (DR Congo). These photoferrotrophs produce oxidized iron {Fe(III)} and biomass and support a diverse pelagic microbial community including heterotrophic Fe(III)-reducers, sulfate reducers, fermenters and methanogens. At modest light levels, rates of photoferrotrophy in KB exceed those predicted for early Earth primary production and are sufficient to generate Earth’s largest sedimentary iron ore deposits. Fe cycling, however, is efficient and complex microbial community interactions likely regulate Fe(III) and organic matter export from the photic zone.
Early amplitude-integrated electroencephalography predicts brain injury and neurological outcome in very preterm infants
Authors: Song Juan , Xu Falin , Wang Laishuan , Gao Liang , Guo Jiajia , Xia Lei , Zhang Yanhua , Zhou Wenhao , Wang Xiaoyang , Zhu Changlian 
Published: September 2015

AbstractEarly amplitude-integrated electroencephalography (aEEG) has been widely used in term infants with brain injury to predict neurodevelopmental outcomes; however, the prognostic value of early aEEG in preterm infants is unclear. We evaluated how well early aEEG could predict brain damage and long-term neurodevelopmental outcomes in very preterm infants compared with brain imaging assessments. We found that severe aEEG abnormalities (p = 0.000) and aEEG total score < 5 (p = 0.006) within 72 h after birth were positively correlated with white-matter damage, but aEEG abnormalities were not associated with intracranial hemorrhage (p = 0.186). Severe abnormalities in aEEG recordings, head ultrasound and cranial magnetic resonance imaging (MRI) were all positively correlated with poor outcome at 18 months corrected age. The predictive power of poor outcomes of the aEEG and MRI combination was the same as the aEEG, MRI and head ultrasound combination with a sensitivity of 52.4%, specificity of 96.2%, positive predictive value of 78.6% and negative predictive value of 88.4%. These results indicate that severely abnormal aEEG recordings within 72 h after birth can predict white-matter damage and long-term poor outcomes in very preterm infants. Thus aEEG can be used as an early marker to monitor very preterm infants.
Proteomic approaches for profiling negative fertility markers in inferior boar spermatozoa
Authors: Kwon Woo-Sung , Oh Shin-Ae , Kim Ye-Ji , Rahman Md Saidur , Park Yoo-Jin , Pang Myung-Geol 
Published: September 2015

AbstractThe ability to predict male fertility is of paramount importance for animal breeding industries and for human reproduction. Conventional semen analysis generally provides information on the quantitative parameters of spermatozoa, but yields no information concerning its functional competence. Proteomics have identified candidates for male fertility biomarkers, but no studies have clearly identified the relationship between the proteome and sperm fertility. Therefore, we performed a proteomic analysis to investigate small and large litter size boar spermatozoa and identify proteins related to male fertility. In this study, 20 proteins showed differential expression levels in small and large litter size groups. Nineteen of these proteins exhibited decreased expression in large litter size samples and increased expression in the small litter group. Interestingly, only one protein was highly expressed in the large litter size spermatozoa. We then identified signaling pathways associated with the differentially expressed protein markers. Glutathione S-transferase Mu3 and glutathione peroxidase 4 were related to the glutathione metabolic pathway and arginine vasopressin receptor 2 was linked to vasopressin R2/STAT. In summary, this is the first study to consider negative fertility biomarkers and the identified proteins could potentially be used as biomarkers for the detection of inferior male fertility.
Simvastatin may induce insulin resistance through a novel fatty acid mediated cholesterol independent mechanism
Authors: Kain Vasundhara , Kapadia Bandish , Misra Parimal , Saxena Uday 
Published: September 2015

AbstractStatins are a class of oral drugs that are widely used for treatment of hypercholesterolemia. Recent clinical data suggest that chronic use of these drugs increases the frequency of new onset diabetes. Studies to define the risks of statin-induced diabetes and its underlying mechanisms are clearly necessary. We explored the possible mechanism of statin induced insulin resistance using a well-established cell based model and simvastatin as a prototype statin. Our data show that simvastatin induces insulin resistance in a cholesterol biosynthesis inhibition independent fashion but does so by a fatty acid mediated effect on insulin signaling pathway. These data may help design strategies for prevention of statin induced insulin resistance and diabetes in patients with hypercholesterolemia.
Ultralight metal foams
Authors: Jiang Bin , He Chunnian , Zhao Naiqin , Nash Philip , Shi Chunsheng , Wang Zejun 
Published: September 2015

AbstractUltralight (<10 mg/cm3) cellular materials are desirable for thermal insulation; battery electrodes; catalyst supports; and acoustic, vibration, or shock energy damping. However, most of these ultralight materials, especially ultralight metal foams, are fabricated using either expensive materials or complicated procedures, which greatly limit their large-scale production and practical applications. Here we report a simple and versatile method to obtain ultralight monolithic metal foams. These materials are fabricated with a low-cost polymeric template and the method is based on the traditional silver mirror reaction and electroless plating. We have produced ultralight monolithic metal foams, such as silver, nickel, cobalt and copper via this method. The resultant ultralight monolithic metal foams have remarkably low densities down to 7.4 mg/cm3 or 99.9% porosity. The metal foams have a long flat stress-train curve in compression tests and the densification strain εD of the Ni/Ag foam with a porosity of 99.8% can reach 82%. The plateau stress σpl was measured and found to be in agreement with the value predicted by the cellular solids theory.
Priming effect of 13C-labelled wheat straw in no-tillage soil under drying and wetting cycles in the Loess Plateau of China
Authors: Liu Enke , Wang Jianbo , Zhang Yanqing , Angers Denis A. , Yan Changrong , Oweis Theib , He Wenqing , Liu Qin , Chen Baoqing 
Published: September 2015

AbstractThe objectives of this study were to determine the effects of drying and wetting (DW) cycles on soil organic carbon (SOC) mineralisation and on the priming effect (PE) induced by the addition of 13C-labelled wheat straw to long-term no-tillage (NT) and conventional-tillage (CT) soils. We observed that the SOC mineralisation rate in rewetted soils was greater than that in soils that were kept at constant water content. The proportion of CO2 derived from the straw declined dramatically during the first 10 days. The priming direction was first positive and then became slightly negative. The PE was higher under DW cycles than under constant water content. There was no significant effect of the tillage system on the SOC mineralisation rate or PE. The data indicate that the DW cycles had a significant effect on the SOC mineralisation rate and on the PE, demonstrating a positive combined effect between wheat straw and moisture fluctuations. Further research is needed to study the role of microbial communities and C pools in affecting the SOC mineralisation response to DW cycles.
Identification of residues important for substrate uptake in a glucose transporter from the filamentous fungus Trichoderma reesei
Authors: Zhang Weixin , Cao Yanli , Gong Jing , Bao Xiaoming , Chen Guanjun , Liu Weifeng 
Published: September 2015

AbstractThe glucose transporter is an important player in cell metabolism that mediates the intracellular uptake of glucose. Here, we characterized the glucose transporter Stp1 from the filamentous fungus Trichoderma reesei. The individual substitution of several conserved residues for Ala in Stp1 corresponding to those interacting with D-glucose in the xylose/H+ symporter XylE inflicted contrasting effects on its ability to support the growth of an hxt-null yeast on glucose. The targeted change of Phe 50, proximal to the substrate-binding site, was also found to exert a profound effect on the activity of Stp1. In contrast with the charged residues, the substitution of Phe 50 with either the hydrophilic residues Asn and Gln or the small residues Gly and Ala significantly enhanced the transport of glucose and its fluorescent analogue, 2-NBDG. On the other hand, a variant with the three substitutions I115F, F199I and P214L displayed remarkably improved activity on glucose and 2-NBDG transport. Further analysis indicated that the combined mutations of Ile 115 and Pro 214, positioned on the lateral surface of the Stp1 N-domain, fully accounted for the enhanced transport activity. These results provide insight into the structural basis for glucose uptake in fungal sugar transporters.
Microdissection of Human Esophagogastric Junction Wall with Phase-contrast X-ray CT Imaging
Authors: Zhang Jianfa , Zhou Guangzhao , Tian Dongping , Lin Runhua , Peng Guanyun , Su Min 
Published: September 2015

AbstractPhase-contrast x-ray imaging using an x-ray interferometer has great potential to reveal the structures inside soft tissues, because the sensitivity of this method to hydrogen, carbon, nitrogen and oxygen is about 1000 times higher than that of the absorption-contrast x-ray method. In this study, we used phase-contrast X-ray CT to investigate human resected esophagogastric junction. This technology revealed the three-layer structure of the esophagogastric junction wall—mucous, submucosa and muscular layers. The mucous and muscular layers were clearly separated by a loose submucosa layer with a honeycomb appearance. The shape of the mucous and muscular layers was intact. The boundary between the mucous and submucosa layers was distinct, as was the border of the muscular and submucosa layers. The surface of the esophagogastric junction was displayed clearly through 3D reconstruction. The technology might be helpful in the diagnosis of esophagogastric junction lesion, especially for the early adenocarcinoma.
Modeling the interplay between the HIF-1 and p53 pathways in hypoxia
Authors: Zhou Chun-Hong , Zhang Xiao-Peng , Liu Feng , Wang Wei 
Published: September 2015

AbstractBoth the hypoxia-inducible factor-1 (HIF-1) and tumor suppressor p53 are involved in the cellular response to hypoxia. How the two transcription factors interact to determine cell fates is less well understood. Here, we developed a network model to characterize crosstalk between the HIF-1 and p53 pathways, taking into account that HIF-1α and p53 are targeted for proteasomal degradation by Mdm2 and compete for binding to limiting co-activator p300. We reported the network dynamics under various hypoxic conditions and revealed how the stabilization and transcriptional activities of p53 and HIF-1α are modulated to determine the cell fate. We showed that both the transrepression and transactivation activities of p53 promote apoptosis induction. This work provides new insight into the mechanism for the cellular response to hypoxia.
Dimerization of lipocalin allergens
Authors: Niemi Merja H. , Rytkönen-Nissinen Marja , Miettinen Ilja , Jänis Janne , Virtanen Tuomas , Rouvinen Juha 
Published: September 2015

AbstractLipocalins are one of the most important groups of inhalant animal allergens. The analysis of structural features of these proteins is important to get insights into their allergenicity. We have determined two different dimeric crystal structures for bovine dander lipocalin Bos d 2, which was earlier described as a monomeric allergen. The crystal structure analysis of all other determined lipocalin allergens also revealed oligomeric structures which broadly utilize inherent structural features of the β-sheet in dimer formation. According to the moderate size of monomer-monomer interfaces, most of these dimers would be transient in solution. Native mass spectrometry was employed to characterize quantitatively transient dimerization of two lipocalin allergens, Bos d 2 and Bos d 5, in solution.
Differential interaction of Apolipoprotein-E isoforms with insulin receptors modulates brain insulin signaling in mutant human amyloid precursor protein transgenic mice
Authors: Chan Elizabeth S , Chen Christopher , Cole Gregory M , Wong Boon-Seng 
Published: September 2015

AbstractIt is unclear how human apolipoprotein E4 (ApoE4) increases the risk for Alzheimer’s disease (AD). Although Aβ levels can lead to insulin signaling impairment, these experiments were done in the absence of human ApoE. To examine ApoE role, we crossed the human ApoE-targeted replacement mice with mutant human amyloid precursor protein (APP) mice. In 26 week old mice with lower Aβ levels, the expression and phosphorylation of insulin signaling proteins remained comparable among APP, ApoE3xAPP and ApoE4xAPP mouse brains. When the mice aged to 78 weeks, these proteins were markedly reduced in APP and ApoE4xAPP mouse brains. While Aβ can bind to insulin receptor, how ApoE isoforms modulate this interaction remains unknown. Here, we showed that ApoE3 had greater association with insulin receptor as compared to ApoE4, regardless of Aβ42 concentration. In contrast, ApoE4 bound more Aβ42 with increasing peptide levels. Using primary hippocampal neurons, we showed that ApoE3 and ApoE4 neurons are equally sensitive to physiological levels of insulin. However, in the presence of Aβ42, insulin failed to elicit a downstream response only in ApoE4 hippocampal neurons. Taken together, our data show that ApoE genotypes can modulate this Aβ-mediated insulin signaling impairment.
Spatio-temporal distribution of human lifespan in China
Authors: Wang Shaobin , Luo Kunli , Liu Yonglin 
Published: September 2015

AbstractBased on the data of latest three Chinese population censuses (1990–2010), four lifespan indicators were calculated: centenarians per one hundred thousand inhabitants (CH); longevity index (LI); the percentage of the population aged at least 80 years (ultra-octogenarian index, UOI) and life expectancy at birth (LEB). The spatio-temporal distributions of data at Chinese county level show that high-longevity areas (high values of CH and LI) and low-longevity areas (low CH and LI values) both exhibit clear non-uniformity of spatial distribution and relative immobility through time. Contrarily, the distribution of UOI and LEB shows a decline from the east to the west. The spatial autocorrelation analyses indicate less spatial dependency and several discontinuous clusters regions of high-CH and LI areas. The factors of temperature, topography and wet/dry climate lack of significant influence on CH and LI. It can be inferred that, in addition to genetic factor and living custom, some unique and long-term environmental effects may be related with high or low values of CH and LI.
Pathway optimization by re-design of untranslated regions for L-tyrosine production in Escherichia coli
Authors: Cheol Kim Seong , Eun Min Byung , Gyu Hwang Hyun , Woo Seo Sang , Yeol Jung Gyoo 
Published: September 2015

AbstractL-tyrosine is a commercially important compound in the food, pharmaceutical, chemical and cosmetic industries. Although several attempts have been made to improve L-tyrosine production, translation-level expression control and carbon flux rebalancing around phosphoenolpyruvate (PEP) node still remain to be achieved for optimizing the pathway. Here, we demonstrate pathway optimization by altering gene expression levels for L-tyrosine production in Escherichia coli. To optimize the L-tyrosine biosynthetic pathway, a synthetic constitutive promoter and a synthetic 5′-untranslated region (5′-UTR) were introduced for each gene of interest to allow for control at both transcription and translation levels. Carbon flux rebalancing was achieved by controlling the expression level of PEP synthetase using UTR Designer. The L-tyrosine productivity of the engineered E. coli strain was increased through pathway optimization resulting in 3.0 g/L of L-tyrosine titer, 0.0354 g L-tyrosine/h/g DCW of productivity and 0.102 g L-tyrosine/g glucose yield. Thus, this work demonstrates that pathway optimization by 5′-UTR redesign is an effective strategy for the development of efficient L-tyrosine-producing bacteria.
RBMMMDA: predicting multiple types of disease-microRNA associations
Authors: Chen Xing , Clarence Yan Chenggang , Zhang Xiaotian , Li Zhaohui , Deng Lixi , Zhang Yongdong , Dai Qionghai 
Published: September 2015

AbstractAccumulating evidences have shown that plenty of miRNAs play fundamental and important roles in various biological processes and the deregulations of miRNAs are associated with a broad range of human diseases. However, the mechanisms underlying the dysregulations of miRNAs still have not been fully understood yet. All the previous computational approaches can only predict binary associations between diseases and miRNAs. Predicting multiple types of disease-miRNA associations can further broaden our understanding about the molecular basis of diseases in the level of miRNAs. In this study, the model of Restricted Boltzmann machine for multiple types of miRNA-disease association prediction (RBMMMDA) was developed to predict four different types of miRNA-disease associations. Based on this model, we could obtain not only new miRNA-disease associations, but also corresponding association types. To our knowledge, RBMMMDA is the first model which could computationally infer association types of miRNA-disease pairs. Leave-one-out cross validation was implemented for RBMMMDA and the AUC of 0.8606 demonstrated the reliable and effective performance of RBMMMDA. In the case studies about lung cancer, breast cancer and global prediction for all the diseases simultaneously, 50, 42 and 45 out of top 100 predicted miRNA-disease association types were confirmed by recent biological experimental literatures, respectively.
Increased frequency of circulating Tc22/Th22 cells and polyfunctional CD38− T cells in HIV-exposed uninfected subjects
Authors: Oliveira Luanda M. S. , Lima Josenilson F. , Cervantes Cesar A. C. , S. Casseb Jorge , Mendonça Marcelo , Duarte Alberto J. S. , Sato Maria N. 
Published: September 2015

AbstractSome individuals are resistant to HIV-1 infection despite repeated exposure to the virus, suggesting the presence of a complex antiviral response. Innate factors like IL-22 exert gut mucosal protection and polyfunctional T cells have been associated with low progression in HIV infection; therefore, we evaluated the frequencies of CD4+ and CD8+ T cell-secreting cytokines, including Tc22/Th22 cells and polyfunctional T cells in HIV-1-exposed uninfected individuals (EUs), their HIV-1-infected partners and healthy controls. EUs exhibited an increased frequency of p15 Gag CD4+ IL-22+ secreting T cells, whereas HIV-infected partners demonstrated a high frequency of CD4+ IL-17+ T cells in response to p24. Similar responses of Th22 and Tc22 cells to Gag peptides and Staphylococcal enterotoxin B (SEB) stimulation were detected in the serodiscordant couples. However, polyfunctionality in HIV subjects was associated with an HIV Gag response of CD38+ T cells, whereas polyfunctionality for EUs was induced upon SEB stimulation by CD38- T cells. EUs demonstrated the presence of Tc22/Th22 cells and polyfunctional CD38- T cells with a low activation profile. These data suggest that SEB-induced polyfunctional CD4+ and CD8+ T cells together with Tc22/Th22 cells in EU individuals can provide an immunological advantage in the response to pathogens such as HIV-1.
Protein folding guides disulfide bond formation
Authors: Qin Meng , Wang Wei , Thirumalai D. 
Published: September 2015

Significance
Anfinsen inferred the principles of protein folding by studying a protein containing four disulfide bonds in the native state. However, how protein folding drives disulfide bond formation is poorly understood despite the role such proteins play in variety of extracellular and intracellular functions. We developed a method to mimic the complex chemistry of disulfide bond formation in molecular simulations, which is used to decipher the mechanism of folding of bovine pancreatic trypsin inhibitor. The flux to the native state is through a complex network of native-like states. Crucially, we establish that it is the conformational folding of the protein that directs disulfide bond formation. Testable predictions and implications for enzyme-catalyzed folding of disulfide proteins in vivo are outlined.