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1. chinaXiv:201703.01026 [pdf]

Soil Water Carrying Capacity for Vegetation in Water Limited Regions

Zhong-sheng Guo
Subjects: Biology >> Ecology

It is necessary to regulate the relationship between plant growth and soil water (RBPGSW) at the appropriate time by reducing the amount of trees or plants present to enable sustainable use of soil water resources, stability of artificial vegetation ecosystems and restoration of a harmonious relationship between humans and nature (i.e. ecological civilization construction) in water-limited regions. However, there is a lack of a universally accepted theory to provide guidance for regulating the RBPGSW in such regions. Here we show that the theory of regulating the RBPGSW in water-limited regions includes the soil water resources use limit by plants (SWRULP) and soil water carrying capacity for vegetation(SWCCV).The RBSWPG should be regulated based on SWCCV when the soil water resources within the maximum infiltration depth equal the SWRULP in forest and grass land in water-limited regions. SWCCV is the population or density of indicator plants when the soil water supply is equal to soil water consumption in the root zone, and changes with plant community type, location and time. The degree of coverage, productivity, carbon-fixation ability and benefits of a plant community when population quantity of an indicator plant equals SWCCV should be the theoretical basis for controlling soil degradation, determining the limit of vegetation restoration, sustainable use of soil water resources and sustainable management of forest vegetation.

submitted time 2017-03-30 Hits3696Downloads532 Comment 0

2. chinaXiv:201703.01020 [pdf]

Selective and recyclable palladium porphyrins-catalyzed oligomerization of tert-butyl acetylene in environment-friendly ionic liquids

Cheng, Jin-Sheng; Wei, Guo-Feng; Zhao, Jin; Huang, Shi-Wen; Huang, Zu-Liang
Subjects: Biology >> Biomedical Laboratory Science

Efficient and selective palladium porphyrins-catalyzed olimerization of tert-butyl acetylene to form (3Z,5Z)-2,2,7,7-tetramethyl-3,6-dihalo-3,5-octadiene has been developed in environmentfriendly ionic liquids. The reaction proceeded readily with effective recycling of the ionic liquids and easy isolation of the products.

submitted time 2017-03-30 Hits1924Downloads722 Comment 0

3. chinaXiv:201703.01019 [pdf]

Hypoxia dysregulates the production of adiponectin and plasminogen activator inhibitor-1 independent of reactive oxygen species in adipocytes

Chen, BY; Lam, KSL; Wang, Y; Wu, DH; Lam, MC; Shen, JG; Wong, LC; Hoo, RLC; Zhang, JL; Xu, AM
Subjects: Biology >> Biomedical Laboratory Science

Low plasma levels of adiponectin (hypoadiponectinemia) and elevated circulating concentrations of plasminogen activator inhibitor (PAI)-1 are causally associated with obesity-related insulin resistance and cardiovascular disease. However, the mechanism that mediates the aberrant production of these two adipokines in obesity remains poorly understood. In this study, we investigated the effects of hypoxia and reactive oxygen species (ROS) on production of adiponectin and PAI-1 in 3T3-L1 adipocytes. Quantitative PCR and immunoassays showed that ambient hypoxia markedly suppressed adiponectin mRNA expression and its protein secretion, and increased PAI-1 production in mature adipocytes. Dimethyloxallyl glycine, a stabilizer of hypoxia-inducible factor 1a (HIF-1a), mimicked the hypoxiamediated modulations of these two adipokines. Hypoxia caused a modest elevation of ROS in adipocytes. However, ablation of intracellular ROS by antioxidants failed to alleviate hypoxia-induced aberrant production of adiponectin and PAI-1. On the other hand, teantioxidants could reverse hydrogen peroxide (H2O2)-induced dysregulation of adiponectin and PAI-1 production. H2O2 treatment decreased the expression levels of peroxisome proliferator-activated receptor gamma (PPARc) and CCAAT/enhancer binding protein (C/EBPa), but had no effect on HIF-1a, whereas hypoxia stabilized HIF-1a and decreased expression of C/EBPa, but not PPARc. Taken together, these data suggest that hypoxia and ROS decrease adiponectin production and augment PAI-1 expression in adipocytes via distinct signaling pathways. These effects may contribute to hypoadiponectinemia and elevated PAI-1 levels in obesity, type 2 diabetes,and cardiovascular diseases.

submitted time 2017-03-30 Hits1747Downloads624 Comment 0

4. chinaXiv:201703.01018 [pdf]

A mechanism for vocal-respiratory coupling in the mammalian parabrachial nucleus

Smotherman, M; Kobayasi, K; Ma, J; Zhang, SY; Metzner, W
Subjects: Biology >> Biomedical Laboratory Science

Mammalian vocalizations require the precise coordination of separate laryngeal and respiratory motor pathways. Precisely how and where in the brain vocal motor patterns interact with respiratory rhythm control is unknown. The parabrachial nucleus (PB) is known to mediate key respiratory reflexes and is also considered a principle component of the mammalian vocal motor pathway, making it a likely site for vocal–respiratory interactions, yet a specific role for the PB in vocalizing has yet to be demonstrated. To investigate the role of the PB in vocal–respiratory coordination, we pharmacologically manipulated synaptic activity in the PB while spontaneously vocalizing horseshoe bats were provoked to emit either short, single syllable or long, multisyllabic vocal motor patterns. Iontophoresis of theGABAA agonist muscimol (MUS) into the lateral PB extended expiratory durations surrounding all vocalizations and increased mean call durations. Alternatively, application of the GABAA antagonist bicuculline methiodide (BIC) shortened expirations and call durations. In addition, BIC eliminated the occurrence of multisyllabic vocalizations. BIC caused a mild increase in quiet breathing rates, whereasMUS tended to slow quiet breathing. The results indicate thatGABAA receptor-mediated inhibition in the lateral PB modulates the time course of respiratory phase switching during vocalizing, and is needed for proper coordination of calling and breathing in mammals. We hypothesize that vocal–respiratory rhythm entrainment is achieved at least in part via mechanisms similar to other forms of locomotorrespiratory coupling, namely somatosensory feedback influences on respiratory phase-switching in the lateral PB.

submitted time 2017-03-30 Hits1685Downloads541 Comment 0

6. chinaXiv:201703.01016 [pdf]

cDNA microarray analysis of differential gene expression and regulation in clinically drug-resistant isolates of Candida albicans from bone marrow transplanted patients

Xu, Zheng; Zhang, Li-Xin; Zhang, Jun-Dong; Cao, Yong-Bing; Yu, an-Yuan Yu; Wang, De-Jun; Ying, Kang; Chen, Wan-Sheng; Jiang, Yuan-Ying
Subjects: Biology >> Biomedical Laboratory Science

Fungi have emerged as the fourth most common pathogens isolated in nosocomial bloodstream infections, and Candida albicans is the most common human fungal pathogen. Only a few antibiotics are effective in the treatment of fungal infections. In addition, the repetition and lengthy duration of fluconazole therapy has led to an increased incidence of azole resistance and treatment failure associated with C. albicans. To investigate the mechanism of drug resistance and explore new targets to treat clinically resistant fungal pathogens, we examined the large-scale gene expression profile of two sets of matched fluconazole-susceptible and -resistant bloodstream C. albicans isolates from bone marrow transplanted (BMT) patients for the first time by microarray analysis. More than 198 differentially expressed genes were identified and they were confirmed and validated by RT-PCR independently. Not surprisingly, the resistant phenotype is associated with increased expression of CDR mRNA, as well as some common genes involved in drug resistance such as CaIFU5, CaRTA2 and CaIFD6. Meanwhile, some special functional groups of genes, including ATP binding cassette (ABC) transporter genes (IPF7530, CaYOR1, CaPXA1), oxidative stress response genes (CaALD5, CaGRP1, CaSOD2, IPF10565), copper transport and iron mobilization-related genes (CaCRD1/2, CaCTR1/2, CaCCC2, CaFET3) were found to be differentially expressed in the resistant isolates. Furthermore, among these differentially expressed genes, some co-regulated with CaCDR1, CaCDR2 and CaIFU5, such as CaPDR16 and CaIFD6, have a DRE-like element and may interact with TAC1 in the promoter region. These findings may shed light on mechanisms of azole resistance in C. albicans and clinical antifungal therapy.

submitted time 2017-03-30 Hits1984Downloads728 Comment 0

8. chinaXiv:201703.01011 [pdf]

Identification of EGFR kinase domain mutations among lung cancer patients in China: implication for targeted cancer therapy

Qin, BM; Chen, X; Zhu, JD; Pei, DQ
Subjects: Biology >> Biomedical Laboratory Science

Lung cancer is one of the leading causes of death with one of the lowest survival rates. However, a subset of lung cancer patients who are of Asian origin and carry somatic mutations in epidermal growth factor receptor or EGFR have responded remarkable well to two tyrosine kinase inhibitors, gefitinib and erlotinib. While EGFR mutation profiles have been reported from Japan, South Korea, and Taiwan, there is no such report from mainland of China where the largest pool of patients reside. In this report, we identified ten somatic mutations from a total of 41 lung cancer patients in China. Among them, seven mutations were found in 17 adenocarcinomas. In contrast to previous reports, eight of these mutations are deletions in exon 19 and two of these deletions are homozygous. These results suggest that a large portion of Chinese adenocarcinoma patients could benefit from gefitinib or erlotinib. This unique mutation profile provides a rationale to develop the next generation of EGFR inhibitors more suitable for the Chinese population.

submitted time 2017-03-30 Hits1492Downloads471 Comment 0

9. chinaXiv:201703.01007 [pdf]

Factors triggering type III secretion in Pseudomonas aeruginosa

Kim, J; Ahn, K; Min, SG; Jia, JH; Ha, UW; Wu, DH; Jin, SG
Subjects: Biology >> Biomedical Laboratory Science

The type III secretion system of Pseudomonas aeruginosa is tightly regulated by various environmental signals, such as low calcium and contact with the host cell. However, the exact signals triggering type III secretion are unknown. The present study describes the finding that secretion of P. aeruginosa type III effector molecules requires protein factors from serum and L broth, designated type III secretion factors (TSFs), in addition to the low-calcium environment.In the absence of TSF or calcium chelator EGTA, basal levels of type III effector molecules are accumulated intracellularly. Addition of TSF and EGTA together effectively triggers the secretion of pre-existing effector molecules in a short time, even before the active expression of type III genes;thus, active type III gene expression does not seem to be a prerequisite for type III secretion.A search for TSF molecules in serum and L broth resulted in the identification of albumin and casein as the functional TSF molecules. Although there is no clear sequence similarity between albumin and casein, both proteins are known to have a low-affinity, high-capacity calcium-binding property. Tests of well-studied calcium-binding proteins seemed to indicate that low-affinity calcium-binding proteins have TSF activity, although the requirement of low-affinity calcium-binding ability for the TSF activity is not clear. P. aeruginosa seems to have evolved a sensing mechanism to detect target cells for type III injection through host-derived proteins in combination with a low-calcium signal. Disruption of the bacterial ability to sense low calcium or TSF might be a valid avenue to the effective control of this bacterial pathogen.

submitted time 2017-03-30 Hits1271Downloads350 Comment 0

10. chinaXiv:201703.00990 [pdf]

Enhanced Rate Capability of Polymer-Derived SiCN Anode Material for Electrochemical Storage of Lithium with 3-D Carbon Nanotube Network Dispersed in Nanoscale

Zhang, JW; Xu, CH; Liu, ZP; Wang, W; Xin, X; Shen, L; Zhou, XB; Zhou, J; Huang, Q (Huang, Q
Subjects: Materials Science >> Nanoscience and Nanotechnology

Electrochemical performances of multi-walled carbon nanotubes (CNT)-SiCN composite have been investigated. The sample was synthesized by a simple ultrasonication assisted method combined with high-temperature pyrolysis and characterized by Fourier transfo

submitted time 2017-03-30 Hits1128Downloads651 Comment 0

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