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91.
A new species of rugose coral, Sanidophyllum dubium n. sp., and the typical Emsian (Early Devonian) rugose coral Xystriphylloides nobilis are described from the Mia Le Formation in northern Vietnam. The lower Emsian index conodonts ranging from the Polygnathus excavatus zone to the P. nothoperbonus zone are illustrated. The biostratigraphic correlation between northern Vietnam and South China shows that the Mia Le Formation in northern Vietnam is early Emsian in age, and its upper part can be correlated with the lower part of the Shizhou Member of the Yukiang Formation in Liujing, Guangxi and its equivalents in South China. Based on the study of the lower Emsian biostratigraphic sequence, the disappearance of Xystriphylloides nobilis fauna in the overlying bed of the uppermost Mia Le Formation and the extinction of the “tonkinensis fauna” (sensu lato) in the interval between the basal Si Phai Formation and the uppermost Mia Le Formation demonstrate the influence of the Yujiang Event in northern Vietnam.  相似文献   
92.
We investigated programmed cell death 1 (PD-1) / programmed cell death ligand 1 (PD-L1) expression in high grade serous ovarian cancer (HGSOC) and its relationship to tumor infiltrating lymphocytes (TIL) and prognosis. Formalin fixed paraffin embedded (FFPE) samples of 94 HGSOC cases were included in the study. Immunohistochemical analysis (CD3, CD4, CD8, PD-1 and PD-L1) was performed. Samples were analyzed for expression of immune proteins in the peritumoral stromal and intratumoral areas, scored, and expression was correlated with overall survival, stage, and age. PD-L1 staining ratio with a score greater than 0 was found to have lower survival. There were two positive staining patterns, patchy/diffuse and patchy/focal patterns, in 24 (25.5%) cases. Considering the threshold value ≥5%, we demonstrated that the PD-L1 positive cancer cell membrane immunoreactivity rate and patchy/diffuse PD-L1 expression were 9.6% (n = 9). There was statistically significant relationship between high PD-1 scores and PD-L1 cases of ≥ 5%. A statistically significant difference was found between PD-L1 staining and survival in patients with a threshold ≥ 5%. However an appropriate rate for treatment was determined in 9.6% cases. There was a statistically significant correlation between PD-1 positive TIL score and intratumoral CD3, peritumoral stromal CD3, intratumoral CD4 and intratumoral CD8 positive cells. Survival was lower in cases with higher PD-L1 positive stromal TIL score.  相似文献   
93.
In prey-predator systems where the interacting individuals are both fliers, the flight performance of both participants heavily influences the probability of success of the predator (the prey is captured) and of the prey (the predator is avoided). While the flight morphology (an estimate of flight performance) of predatory wasps has rarely been addressed as a factor that may contribute to explain prey use, how the flight morphology of potential prey influences the output of predator-prey encounters has not been studied. Here, we hypothesized that flight morphology associated with flight ability (flight muscle mass to body mass ratio (FMR) and body mass to wing area ratio (wing loading, WL)) of Diptera affect their probability of being captured by specialized Diptera-hunting wasps (Bembix merceti and B. zonata), predicting a better manoeuvrability and acceleration capacity achieved by higher FMR and lower WL, and flight speed achieved by higher WL. In addition, wasp species with better flight morphology should be less limited by an advantageous Diptera flight morphology. Overall, the abundance of dipterans in the environment explained an important part of the observed variance in prey capture rate. However, it was not the only factor shaping prey capture. First, higher prey abundance was associated with greater capture rate for one species (B. merceti), although not for the other one. Second, the interaction observed between the environmental dipteran availability and dipteran WL for B. zonata suggests that greater dipteran WL (this probably meaning high cruising speed) decreased the probability of being captured, as long as fly abundance was high in the environment. Third, greater dipteran FMR (which likely means high manoeuvrability and acceleration capacity) helped to reduce predation by B. merceti if, again, dipterans were abundant in the environment. Wasp WL only varied with body mass but not between species, thereby hardly accounting for inter-specific differences in the wasps’ predatory patterns. However, the greater FMR of B. zonata, which implies better flight performance and greater load-lifting capacity, may explain why the capture rate in the two wasp species is affected by different factor interactions. In conclusion, although prey availability remains the primary factor shaping prey use, prey flight morphology seems to gain an additional role under conditions of abundant prey, when wasps can avoid flies with better flight ability.  相似文献   
94.
Ba  Fang  Zhou  Yuxin  Zhou  Jie  Chen  Xueyun 《Molecular and cellular biochemistry》2019,458(1-2):71-78
Molecular and Cellular Biochemistry - Repetitive transcranial magnetic stimulation (rTMS) is a technique protecting neurons against diverse neurodegenerative disorders by delivering magnetic...  相似文献   
95.
96.
The spectra of mutations and polymorphic loci of the gene of cystic fibrosis transmembrane conductance regulator (CFTR) was studied in 60 cystic fibrosis (CF) families from Bashkortostan. Mutations delF508, 394delTT, CFTRdele2,3(21 kb), R334W, and S1196X (33.3, 3.3, 1.7, 0.8, and 0.8%, respectively) were identified. The frequencies of tandem tetranucleotide repeat (TTR) alleles were determined for locus IVS6a-GATT of intron 6 of the CFTR gene and two extragenic loci flanking the CFTR gene, D7S23 and MET (probes CS.7 and MetH) in mutant and normal chromosomes. Allelic and haplotypic associations of these loci with the mutations found were estimated. An absolute linkage between the 6TTR allele of locus IVS6a-GATT and the delF508 mutation was ascertained. A considerable linkage disequilibrium between the delF508 mutation and the C2 allele of locus D7S23 and between this mutation and the A1 allele of locus MET was found. Most of the other mutant chromosomes carried marker alleles 7TTR, C1, and A2. It was demonstrated that 67% of CF chromosomes carrying delF508 had haplotype 6-2-1 for loci IVS6a-GATT/D7S23/MET, respectively. The frequency distribution of haplotypes in CF chromosomes without delF508 had a high variance and did not differ significantly from the distribution in normal chromosomes (chi 2 = 9.415; p > 0.05).  相似文献   
97.
Airway smooth muscle (ASM) hypertrophy and hyperplasia are characteristics of asthma that lead to thickening of the airway wall and obstruction of airflow. Very little is known about mechanisms underlying ASM remodeling, but in vascular smooth muscle, it is known that progression of atherosclerosis depends on the balance of myocyte proliferation and cell death. Small heat shock protein 27 (Hsp27) is antiapoptotic in nonmuscle cells, but its role in ASM cell survival is unknown. Our hypothesis was that phosphorylation of Hsp27 may regulate airway remodeling by modifying proliferation, cell survival, or both. To test this hypothesis, adenoviral vectors were used to overexpress human Hsp27 in ASM cells. Cells were infected with empty vector (Ad5) or wild-type Hsp27 (AdHsp27 WT), and proliferation and death were assessed. Overexpressing Hsp27 WT caused a 50% reduction in serum-induced proliferation and increased cell survival after exposure to 100 microM hydrogen peroxide (H(2)O(2)) compared with mock-infected controls. Overexpression studies utilizing an S15A, S78A, and S82A non-phosphorylation mutant (AdHsp27 3A) and an S15D, S78D, and S82D pseudo-phosphorylation mutant (AdHsp27 3D) showed phosphorylation of Hsp27 was necessary for regulation of ASM proliferation, but not survival. Hsp27 provided protection against H(2)O(2)-induced cytotoxicity by upregulating cellular glutathione levels and preventing necrotic cell death, but not apoptotic cell death. The results support the notion that ASM cells can be stimulated to undergo proliferation and death and that Hsp27 may regulate these processes, thereby contributing to airway remodeling in asthmatics.  相似文献   
98.
A phylogeographic study was conducted on the Nile grass rat, Arvicanthis niloticus, a rodent species that is tightly associated with open grasslands from the Sudano-Sahelian regions. Using one mitochondrial (cytochrome b) and one nuclear (intron 7 of Beta Fibrinogen) gene, robust patterns were retrieved that clearly show that (i) the species originated in East Africa concomitantly with expanding grasslands some 2 Ma, and (ii) four parapatric and genetically well-defined lineages differentiated essentially from East to West following Pleistocene bioclimatic cycles. This strongly points towards allopatric genetic divergence within savannah refuges during humid episodes, then dispersal during arid ones; secondary contact zones would have then stabilized around geographic barriers, namely, Niger River and Lake Chad basins. Our results pertinently add to those obtained for several other African rodent as well as non-rodent species that inhabit forests, humid zones, savannahs and deserts, all studies that now allow one to depict a more comprehensive picture of the Pleistocene history of the continent south of the Sahara. In particular, although their precise location remains to be determined, at least three Pleistocene refuges are identified within the West and Central African savannah biome.  相似文献   
99.
Several studies have shown evidence of an association between the *4 allele of apolipoprotein E (APOE) and coronary heart disease (CHD) in different populations. We determined the APOE genotype and total cholesterol (TC), triglycerides (TG), and high-density lipoprotein cholesterol (HDLC) values in 189 patients with angiographically evaluated atherosclerosis. The APOE*4 allele was found to be statistically significantly more frequent (odds ratio, 1.93; 95% confidence interval, 1.12-3.32) among male patients than in a randomly chosen population-based sample. No significant difference was found when female patients were compared to the general population. The APOE*4 allele was found primarily among young (30-45-year-old) male patients (p < 0.04). Despite the ascending linear tendency of the mean TC values for genotypes APOE*2/*3, APOE*3/*3, and APOE*3/ *4 reported in our case population, no differences were observed among our patients. We conclude that the APOE*4 allele is associated with an increased risk for atherosclerotic vascular disease, that this association has an age-dependent effect, and that it acts as a genetic factor that increases susceptibility to developing the disease in young to middle-aged male adults in our population.  相似文献   
100.
? Selenium (Se) hyperaccumulation has a profound effect on plant-arthropod interactions. Here, we investigated floral Se distribution and speciation in flowers and the effects of floral Se on pollen quality and plant-pollinator interactions. ? Floral Se distribution and speciation were compared in Stanleya pinnata, an Se hyperaccumulator, and Brassica juncea, a comparable nonhyperaccumulator. Pollen germination was measured from plants grown with varying concentrations of Se and floral visitation was compared between plants with high and low Se. ? Stanleya pinnata preferentially allocated Se to flowers, as nontoxic methyl-selenocysteine (MeSeCys). Brassica juncea had higher Se concentrations in leaves than flowers, and a lower fraction of MeSeCys. For B. juncea, high floral Se concentration impaired pollen germination; in S. pinnata Se had no effect on pollen germination. Floral visitors collected from Se-rich S. pinnata contained up to 270 μg g(-1), concentrations toxic to many herbivores. Indeed, floral visitors showed no visitation preference between high- and low-Se plants. Honey from seleniferous areas contained 0.4-1 μg Se g(-1), concentrations that could provide human health benefits. ? This study is the first to shed light on the possible evolutionary cost, through decreased pollen germination in B. juncea, of Se accumulation and has implications for the management of seleniferous areas.  相似文献   
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