Nasopharyngeal carcinoma (NPC) is a unique epithelial malignancy that shows a remarkable geographical and ethic distribution. Multiple factors including predisposing genetic factors, environmental ...carcinogens, and Epstein-Barr virus (EBV) infection contribute to the accumulation of genetic and epigenetic alterations leading to NPC development. Emerging technologies now allow us to detailedly characterize and understand cancer genomes. Genome-wide studies show that typically NPC tumors are characterized as having comparatively low mutation rates, widespread hypermethylation, and frequent copy number alterations and chromosome abnormalities. In this review, we provide an updated overview of the genetic and epigenetic aberrations that likely drive nasopharyngeal tumor development and progression. We integrate the previous knowledge and novel findings from whole-exome sequencing (WES) and methylome studies in NPC, and further discuss the potential use of these findings to identify biomarkers for NPC diagnosis and prognosis.
The hand-held soil plant analysis development （SPAD） chlorophyll meter nitrogen status of the potato and guiding fertilization recommendations N recommendation, it is critical to establish the ...threshold SPAD value has proved to be a promising tool in evaluating the n the process of N evaluation of potato plants and （SPAD reading）, below which nitrogen supplement is required. And taking convenient using into account, the threshold needs to be dynamic throughout the potato growing season so that the users can test their potato plants and make fertilization decision at any growing time of potato. To complete this goal, field experiments with different nitrogen supply levels were conducted in different sites in northern China from 2009 to 2011. The results showed that threshold SPAD values decrease as the growing season progresses for all cultivars and planting sites. By statistical analysis, the threshold regression models were established respectively as： y=-0.003χ2-0.0507χ＋58.213 （y, threshold SPAD value; χ, days after emergence） for the potato cultivar Kexin 1, and y=-0.003χ2＋0.017χ＋52.489 （y, threshold SPAD value; χ, days after emergence） for the cultivar Shepody, from which, the threshold SPAD value at any day after emergence can be calculated.
Abstract
Background
Although depression has been a serious neuropsychiatric disorder worldwide, current antidepressants used in clinical practice have various weaknesses, including delayed onset and ...low rates of efficacy. Recently, the development of new antidepressants from natural herbal medicine has become one of the important research hotspots. Cucurbitacin B is a natural compound widely distributed in the Cucurbitaceae and Cruciferae families and has many pharmacological activities. The present study aimed to investigate whether cucurbitacin B possess antidepressant-like effects in mice.
Methods
The antidepressant-like effects of cucurbitacin B on mice behaviors were explored using the forced swim test, tail suspension test, open field test, sucrose preference test, and a chronic unpredictable mild stress model of depression together. Then, western blotting and immunofluorescence were used to examine the effects of cucurbitacin B on the brain-derived neurotrophic factor (BDNF)-tyrosine kinase B (TrkB) signaling cascade and neurogenesis in the hippocampus of mice. Furthermore, BDNF-short hairpin RNA, K252a, and p-chlorophenylalanine methyl ester were adopted together to determine the antidepressant mechanism of cucurbitacin B.
Results
It was found that administration of cucurbitacin B indeed produced notable antidepressant-like effects in mice, which were accompanied with significant promotion in both the hippocampal BDNF-TrkB pathway and neurogenesis. The antidepressant mechanism of cucurbitacin B involves the hippocampal BDNF-TrkB system but not the serotonin system.
Conclusions
Cucurbitacin B has the potential to be a novel antidepressant candidate.
Proton exchange membrane (PEM) is one of the core materials which were widely used in the field of fuel cells (FCs). In recent years, the metal organic frameworks (MOFs) and polymer composite ...membranes as tunable proton-conducting materials have showed great potential in this field. Herein, a Cu(II)-based metal organic framework (Cu-MOF) with acid/base stability was introduced into poly(vinylpyrrolidone)/poly(vinylidene fluoride) (PVP/PVDF, PP) to fabricate hybrid membranes(Cu-MOF@PP-X, where X is the % Cu-MOF content). The effects of Cu-MOF loading amounts on the conductive behavior of Cu-MOF@PP-X composites have been documented. It is worth noting that Cu-MOF@PP-50 exhibited the proton conductivity up to 4.36 × 10−4 S cm−1 at 353 K and 98% relative humidity (RH). In addition, the value of proton conduction is about two orders of magnitude higher than that of the parent Cu-MOF (1.91 × 10−6 S cm−1). This work contributes to driving further advances of MOF/polymer composites in proton-conducting apparatus.
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•A Cu-MOF with acid/base stability was introduced into polymers (PVP/PVDF, PP) to fabricate hybrid membranes.•The effects of Cu-MOF loading amounts on the conductive behavior of Cu-MOF@PP-X composites have been documented.•Cu-MOF@PP-50 exhibited a super protonic conductivity up to 4.36 × 10−4 S cm−1 at 353 K and 98% relative humidity (RH).•The value of proton conduction of Cu-MOF@PP-50 is about two orders of magnitude higher than that of the parent Cu-MOF.
The upper mantle structure of Southeast China is important for us to understand the deformation and mantle dynamics process associated with the interaction between the Eurasian plate and Philippine ...Sea (PHS) slab. We determined a detailed three-dimensional P-wave velocity (Vp) structure of the crust and upper mantle down to 400km depth beneath Southeast China by applying teleseismic tomography to 6869 high-quality P-wave arrival times. The data were collected very carefully from the original seismograms of 635 teleseismic events recorded by 65 broadband stations deployed in Southeast China. Our images show that the high-Vp PHS slab subducts toward the north along the Ryukyu trench at the latitude of about 24°N and extends down to 350km depth and even more. High-Vp anomalies are imaged in the upper mantle under central and southern Taiwan, which represent the subducted Eurasian plate. Break-off Eurasian plate at a big angle subducting eastward is revealed under central Taiwan at depths from the upper mantle to 400km. While continuous Eurasian plate under South Taiwan is mainly imaged from the Moho down to 400km depth, a torn mantle window within the Eurasian continent beneath central and northern Taiwan created by the northward motion of the Philippine Sea plate is the upwelling path of the asthenosphere. The tomographic images also show the low-Vp anomalies spread widely under the coastal areas of Mainland China and Taiwan Strait. The structure of the crust and upper mantle suggests that the mountain building process in the central part of Taiwan is mainly attributed to the subduction–collision tectonics at the boundary between the Eurasian continental lithosphere and the subducting oceanic lithosphere of the PHS slab.
•The PHS slab subducts toward the north along the Ryukyu trench.•Break-off Eurasian plate subducting eastward is revealed under central Taiwan.•Continuous Eurasian plate is imaged under South Taiwan.•The low-Vp anomalies spread widely under the coastal areas of Mainland China.•A torn mantle window of Eurasian plate is the asthenosphere upwelling path.
Summary
Staphylococcus epidermidis strains are diverse in their pathogenicity; some are invasive and cause serious nosocomial infections, whereas others are non‐pathogenic commensal organisms. To ...analyse the implications of different virulence factors in Staphylococcus epidermidis infections, the complete genome of Staphylococcus epidermidis strain ATCC 12228, a non‐biofilm forming, non‐infection associated strain used for detection of residual antibiotics in food products, was sequenced. This strain showed low virulence by mouse and rat experimental infections. The genome consists of a single 2499 279 bp chromosome and six plasmids. The chromosomal G + C content is 32.1% and 2419 protein coding sequences (CDS) are predicted, among which 230 are putative novel genes. Compared to the virulence factors in Staphylococcus aureus, aside from δ‐haemolysin and β‐haemolysin, other toxin genes were not found. In contrast, the majority of adhesin genes are intact in ATCC 12228. Most strikingly, the ica operon coding for the enzymes synthesizing interbacterial cellular polysaccharide is missing in ATCC 12228 and rearrangements of adjacent genes are shown. No mec genes, IS256, IS257, were found in ATCC 12228. It is suggested that the absence of the ica operon is a genetic marker in commensal Staphylococcus epidermidis strains which are less likely to become invasive.
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•The proposed model is validated using the experimental and empirical data.•Three typical spatial distributions of pore diameter and porosity are investigated and evaluated ...comprehensively.•A decreasing pore diameter and porosity toward the particle core is the optimal distribution.•A comprehensive sensitivity analysis is performed.
This modeling study investigates the influence of spatially distributed pore size and porosity on diffusional and reactive features inside the methanol-to-olefin (MTO) porous catalyst particle. The model developed in this study integrates mass, momentum and heat balance equations, spatial pore size and porosity distribution models, multicomponent diffusion and lumped kinetic models. The proposed model was first validated by using the experimental and empirical data. The simulation results demonstrated that the pore diameter and porosity that decrease toward the particle core is the optimal distribution for the MTO catalyst particle. Subsequent parametric sensitivity analysis indicated that the temperature plays the most significant role in the effectiveness factor. The smaller pore diameter favors the larger ratio of the ethylene to the propylene. Comparing with the traditional trial-and-error methods, the proposed model is simple but effective, which is valuable for the design and optimization of porous catalyst particles.
QUESTION: We investigated the bryophyte communities on tree boles along three altitudinal gradients located within different types of forested area to answer the following questions: (1) how many ...bole epiphytic bryophyte species are there; (2) what are the dominant species; (3) what are the richness patterns of epiphytic bryophyte communities along the altitudinal gradients; and (4) what are the major drivers and conservation implications of these patterns? LOCATION: Three protected forested areas in sub‐montane (Mengla transect: 800–1400 m), montane (Zhenyuan transect: 2000–2600 m) and sub‐alpine (Lijiang transect: 3200–3800 m) regions in Yunnan, SW China. METHOD: Sixty 20 m × 20 m sampling plots were established, five at each of 12 altitudes at 200‐m intervals along the transects. Species composition and cover of bryophytes were investigated from 594 subplots (each 400 cm²) on large tree boles of these plots. One‐way ANOVAs were adopted to test for differences in species diversity among different transects. Multi‐dimensional scaling in two dimension (MDS‐2D) ordinations were conducted to assess similarity of bryophyte communities among study transects and altitudes. Canonical correspondence analysis (CCA) was applied to relate species composition to selected environmental variables. RESULTS: The three protected forests in Yunnan harboured 226 epiphytic bryophyte species belonging to 101 genera and 46 families, which were essential components of biodiversity of the entire forest ecosystem. In total, 99% of bryophyte species (224 species) showed varying degrees of local rarity. Smooth mat, fan and turf dominated in the sub‐montane, montane and sub‐alpine forests, respectively. Significantly lower bryophyte species richness was detected in the sub‐montane area, which may be partly attributed to higher temperature, limited water availability and more frequent human disturbance. Epiphytic bryophytes exhibited a hump‐shaped species richness pattern with increasing altitude. Peak richness coincided with highest moisture levels at ca. 2600 m. CONCLUSIONS: Based on the presence of a high diversity of bryophytes and a high percentage (99%) of locally rare species growing on tree boles, this study emphasizes the importance of conserving these forests in Yunnan. Additionally, the regional pattern of lower epiphytic bryophyte diversity in warmer, drier areas shown in this study reveals how emerging climate change threatens Yunnan's epiphytic bryophytes.
Zingiber cassumunar is an important plant used in traditional medicine and as a natural mosquito repellent. However, the compounds responsible for the repellent activity of the plant are still ...unknown. The aim of the study is to identify the components of Z. cassumunar essential oil that show repellent activity against Aedes albopictus. We also evaluated the larvicidal and adulticidal activities of Z. cassumunar essential oil against Ae. albopictus. In-cage mosquito repellent experiments showed that Z. cassumunar essential oil possessed moderate repellent activity with a minimum effective dose (MED) of 0.16 ± 0.01 mg/cm2, compared to reference standard N,N-diethyl-3-methylbenzamide (DEET, 0.03 ± 0.01 mg/cm2). Bioassay-guided fractionation identified the major active compound of Z. cassumunar essential oil as (−)-terpinen-4-ol (1) (MED: 0.19 ± 0 mg/cm2). We also found that Z. cassumunar essential oil showed moderate larvicidal activity against first instar larvae of Ae. albopictus with a LC50 (50% lethal concentration) of 44.9 μg/L after 24 h. Fumigation bioassays showed that Z. cassumunar essential oil exhibits moderate adulticidal activity against Ae. albopictus with a LC50 of 5.44%, while (−)-terpinen-4-ol showed significant adulticidal activity with a LC50 of 2.10% after 24 h. This study verifies that the Z. cassumunar essential oil has mosquito repellent activity, and that (−)-terpinen-4-ol is mainly responsible for this activity. Furthermore, this study provides scientific support for the folk usage of Z. cassumunar essential oil as mosquito repellent and indicates that Z. cassumunar essential oil and (−)-terpinen-4-ol can be used as plant-derived repellents and insecticides for mosquito control.
Epoxidation of the carbon-carbon double bonds on unsaturated rubber macromolecules can produce novel modified rubber species with special properties, and construct eco-friendly crosslinking pathway
...via
the reaction of epoxide groups to solve the problems brought by conventional sulfur vulcanization system. In this contribution, a novel modified product of isobutylene isoprene rubber (IIR), epoxy-functionalized IIR (EIIR) was successfully prepared by
in situ
epoxidation technique for the first time, and the crosslinking of EIIR was achieved by the reaction of oxirane groups with maleic anhydride (MAH) without additional additives. The reaction conditions for preparing EIIR were optimized through systematic research on the epoxidation process. Under optimal condition, the degree of epoxidation of the rubber reached around 99% without side reactions. The obtained EIIR/carbon black composites cured by MAH had excellent mechanical properties comparable to those of IIR composites. More importantly, compared with IIR composites, the air-tightness of the EIIR composites was improved by about 50%, and the flexural fatigue life of first-level cracks and sixth-level cracks was increased by several times. The significant improvement of these properties is of great significance for the application safety and energy saving of IIR materials.
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