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61.
Two new flavonoids, fistulaflavonoids B and C (1–2), together with five known flavonoids (3–7) were isolated from the bark and stems of Cassia fistula. Their structures were determined by means of HRESIMS, extensive 1D and 2D NMR spectroscopic studies and chemical evidences. The anti-tobacco mosaic virus (anti-TMV) activity of the isolated flavonoids was also evaluated. The results showed that compounds 1 and 2 showed high anti-TMV activity with inhibition rate of 28.5% and 31.3%, which is higher than that of Ningnanmycin (24.7%). Compounds 4–7 showed modest anti-TMV activity with inhibition rate of 18.5%, 22.7%, 16.4%, and 15.3%, respectively.  相似文献   
62.
The western Ordos Plateau is a key area of shrub diversity and a National Nature Reserve of endangered shrub species in north-west China. Desert expansion is becoming the most important threat to these endangered species. However, little is known about the effects of sand burial on the dynamics of the shrub community. This study aims to investigate how the shrubs as a community and as different individual shrubs respond to the disturbances caused by the desert expansion. The approach used by this study is to separate the seed-dispersal strategy from the sand-burial forces that are involved in structuring the shrub communities at different disturbance stages. Four communities for different disturbance stages were surveyed by using 50×50 m plots. The individual shrubs were classified into coloniser and successor groups at the seed-dispersal stage and strong and weak sand-burial tolerance groups at the sand-expansion stage. We employed spatial point pattern analysis with null models for each community to examine the seed-dispersal strategy and sand-burial forces affecting community distribution patterns. At the seed-dispersal stage, the interactions between the colonisers and the successors showed significant positive correlation at a scale of 0–1 m and significant negative correlation at a scale of 2 m; significant negative correlations between the groups with strong and weak sand-burial tolerance in the early stage of sand expansion at scales of 3–6 m, and significant positive correlation in the later stage of sand expansion at a scale of 13 m, were found. Seed-dispersal strategy is a reasonable mechanism to explain the shrub community pattern formation in the earlier stages, whereas sand burial is the primary reason for the disappearance of shrubs with weak sand-burial tolerance, this irreversible disturbance causes homogenisation of the community structure and produces aging populations of shrub species. This has an important influence on the succession direction of desert shrub communities.  相似文献   
63.
The anti-apoptotic protein B-cell CLL/lymphoma 2 (Bcl-2) gene is a major regulator of neural plasticity and cellular resilience. Recently, the Bcl-2 rs956572 single nucleotide polymorphism was proposed to be a functional allelic variant that modulates cellular vulnerability to apoptosis. Our cross-sectional study investigated the genetic effect of this Bcl-2 polymorphism on age-related decreases in gray matter (GM) volume across the adult lifespan. Our sample comprised 330 healthy volunteers (191 male, 139 female) with a mean age of 56.2±22.0 years (range: 21–92). Magnetic resonance imaging and genotyping of the Bcl-2 rs956572 were performed for each participant. The differences in regional GM volumes between G homozygotes and A-allele carriers were tested using optimized voxel-based morphometry. The association between the Bcl-2 rs956572 polymorphism and age was a predictor of regional GM volumes in the right cerebellum, bilateral lingual gyrus, right middle temporal gyrus, and right parahippocampal gyrus. We found that the volume of these five regions decreased with increasing age (all P<.001). Moreover, the downward slope was steeper among the Bcl-2 rs956572 A-allele carriers than in the G-homozygous participants. Our data provide convergent evidence for the genetic effect of the Bcl-2 functional allelic variant in brain aging. The rs956572 G-allele, which is associated with significantly higher Bcl-2 protein expression and diminished cellular sensitivity to stress-induced apoptosis, conferred a protective effect against age-related changes in brain GM volume, particularly in the cerebellum.  相似文献   
64.

Background

The central function of chloroplasts is to carry out photosynthesis, and its gene content and structure are highly conserved across land plants. Parasitic plants, which have reduced photosynthetic ability, suffer gene losses from the chloroplast (cp) genome accompanied by the relaxation of selective constraints. Compared with the rapid rise in the number of cp genome sequences of photosynthetic organisms, there are limited data sets from parasitic plants.

Principal Findings/Significance

Here we report the complete sequence of the cp genome of Cistanche deserticola, a holoparasitic desert species belonging to the family Orobanchaceae. The cp genome of C. deserticola is greatly reduced both in size (102,657 bp) and in gene content, indicating that all genes required for photosynthesis suffer from gene loss and pseudogenization, except for psbM. The striking difference from other holoparasitic plants is that it retains almost a full set of tRNA genes, and it has lower dN/dS for most genes than another close holoparasitic plant, E. virginiana, suggesting that Cistanche deserticola has undergone fewer losses, either due to a reduced level of holoparasitism, or to a recent switch to this life history. We also found that the rpoC2 gene was present in two copies within C. deserticola. Its own copy has much shortened and turned out to be a pseudogene. Another copy, which was not located in its cp genome, was a homolog of the host plant, Haloxylon ammodendron (Chenopodiaceae), suggesting that it was acquired from its host via a horizontal gene transfer.  相似文献   
65.
A meta-analysis was performed to assess the association between the PAI-1 -675 4G/5G polymorphism and susceptibility to diabetes mellitus (DM), diabetic nephropathy (DN), diabetic retinopathy (DR) and diabetic coronary artery disease (CAD). A literature-based search was conducted to identify all relevant studies. The fixed or random effect pooled measure was calculated mainly at the allele level to determine heterogeneity bias among studies. Further stratified analyses and sensitivity analyses were also performed. Publication bias was examined by the modified Begg’s and Egger’s test. Twenty published articles with twenty-seven outcomes were included in the meta-analysis: 6 studies with a total of 1,333 cases and 3,011 controls were analyzed for the PAI-1 -675 4G/5G polymorphism with diabetes risk, 7 studies with 1,060 cases and 1,139 controls for DN risk, 10 studies with 1,327 cases and 1,557 controls for DR and 4 studies with 610 cases and 1,042 controls for diabetic CAD risk respectively. Using allelic comparison (4G vs. 5G), the PAI-1 -675 4G/5G polymorphism was observed to have no significant association with diabetes (REM OR 1.07, 95% CI 0.96, 1.20), DN (REM OR 1.10, 95% CI 0.98, 1.25), DR (REM OR 1.09, 95% CI 0.97, 1.22) or diabetic CAD risk (REM OR 1.07, 95% CI 0.81, 1.42), and similar results were obtained in the dominant, recessive and co-dominant models. Our meta-analyses suggest that the PAI-1 -675 4G/5G polymorphism might not be a risk factor for DM, DN, DR or diabetic CAD risk in the populations investigated. This conclusion warrants confirmation by further studies.  相似文献   
66.
Prostate cancer (PCa) is a global disease causing large numbers of deaths every year. Recent studies have indicated the RTK/ERK pathway might be a key pathway in the development of PCa. However, the exact association and evolution-based mechanism remain unclear. This study was conducted by combining genotypic and phenotypic data from the Chinese Consortium for Prostate Cancer Genetics (ChinaPCa) with related databases such as the HapMap Project and Genevar. In this analysis, expression of quantitative trait loci (eQTLs) analysis, natural selection and gene-based pathway analysis were involved. The pathway analysis confirmed the positive relationship between PCa risk and several key genes. In addition, combined with the natural selection, it seems that 4 genes (EGFR, ERBB2, PTK2, and RAF1) with five SNPs (rs11238349, rs17172438, rs984654, rs11773818, and rs17172432) especially rs17172432, might be pivotal factors in the development of PCa. The results indicate that the RTK/ERK pathway under natural selection is a key link in PCa risk. The joint effect of the genes and loci with positive selection might be one reason for the development of PCa. Dealing with all the factors simultaneously might give insight into prevention and aid in predicting the success of potential therapies for PCa.  相似文献   
67.
The design of optimized nanoparticles offers a promising strategy to enable DNA vaccines to cross various physiological barriers for eliciting a specific and protective mucosal immunity via intranasal administration. Here, we reported a new designed nanoparticle system through incorporating anionic liposomes (AL) into chitosan/DNA (CS/DNA) complexes. With enhanced cellular uptake, the constructed AL/CS/DNA nanoparticles can deliver the anti-caries DNA vaccine pGJA-P/VAX into nasal mucosa. TEM results showed the AL/CS/DNA had a spherical structure. High DNA loading ability and effective DNA protection against nuclease were proved by gel electrophoresis. The surface charge of the AL/CS/DNA depended strongly on pH environment, enabling the intracellular release of loaded DNA via a pH-mediated manner. In comparison to the traditional CS/DNA system, our new design rendered a higher transfection efficiency and longer residence time of the AL/CS/DNA at nasal mucosal surface. These outstanding features enable the AL/CS/DNA to induce a significantly (p<0.01) higher level of secretory IgA (SIgA) than the CS/DNA in animal study, and a longer-term mucosal immunity. On the other hand, the AL/CS/DNA exhibited minimal cytotoxicity. These results suggest that the developed nanoparticles offer a potential platform for DNA vaccine packaging and delivery for more efficient elicitation of mucosal immunity.  相似文献   
68.
69.
Administration of cocaine increases locomotor activity by enhancing dopamine transmission. To explore the peripheral mechanisms underlying acupuncture treatment for drug addiction, we developed a novel mechanical acupuncture instrument (MAI) for objective mechanical stimulation. The aim of this study was to evaluate whether acupuncture inhibition of cocaine-induced locomotor activity is mediated through specific peripheral nerves, the afferents from superficial or deep tissues, or specific groups of nerve fibers. Mechanical stimulation of acupuncture point HT7 with MAI suppressed cocaine-induced locomotor activity in a stimulus time-dependent manner, which was blocked by severing the ulnar nerve or by local anesthesia. Suppression of cocaine-induced locomotor activity was elicited after HT7 stimulation at frequencies of either 50 (for Meissner corpuscles) or 200 (for Pacinian corpuscles) Hz and was not affected by block of C/Aδ-fibers in the ulnar nerve with resiniferatoxin, nor generated by direct stimulation of C/Aδ-fiber afferents with capsaicin. These findings suggest that HT7 inhibition of cocaine-induced locomotor activity is mediated by A-fiber activation of ulnar nerve that originates in superficial and deep tissue.  相似文献   
70.
Highlights? RIP3 deficiency in macrophages reduces advanced atherosclerotic lesions ? RIP3 deficiency reduces primary necrosis of macrophages in advanced lesions ? RIP3-dependent macrophage necrosis is not postapoptotic cell death ? Increased RIP3 converts apoptosis to necrosis in advanced lesional macrophages  相似文献   
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