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181.
Emam ElHak Abdel Fatah Natalie R. Shirley Mohamed R. Mahfouz Benjamin M. Auerbach 《American journal of physical anthropology》2012,149(4):547-559
This study presents a novel three‐dimensional analysis using statistical atlases and automated measurements to assess diaphyseal morphology of the clavicle and its relationship to muscle asymmetry. A sample of 505 individuals (285 males, 220 females) from the William McCormick Clavicle Collection was CT scanned, segmented, and added to a statistical bone atlas that captures correspondence between homologous points on the bone surfaces. Muscle attachment sites were localized on the atlas and then propagated across the entire population. Cross‐sectional contours were extracted at 5% increments along the entire bone, as well as at muscle attachment sites and the clavicle waist; maximum and minimum dimensions of each cross‐sectional contour were calculated. In addition, the entire three‐dimensional surface was examined for asymmetry by analyzing the magnitude and directional differences between homologous points across all bone surfaces in the dataset. The results confirm the existing studies on clavicle asymmetry, namely that the left clavicle is longer than the right, but the right is more robust than the left. However, the patterns of asymmetry are sexually dimorphic. Males are significantly asymmetric in all dimensions and at muscle and ligament attachment sites (P < 0.05), whereas female asymmetry is more variable. We hypothesize that this is related to absolute and relative differences in male muscle strength compared to females. However, an area with no muscle attachments on the posterior midshaft was significantly asymmetric in both sexes. We suggest that this is a curvature difference caused by opposing muscle actions at the medial and lateral ends of the bone. Am J Phys Anthropol 2012. © 2012 Wiley Periodicals, Inc. 相似文献
182.
Because metals can produce health risks, standards for regulating metal exposure are necessary. The purpose of this chapter is to review the application of uncertainty factors to mercury, arsenic, and cadmium. By the conventional method, uncertainty factors are often applied to animal studies to establish the reference dose (RfD) in humans. However, with the availability of a better database from improved study designs, it was demonstrated that uncertainty factors can be decreased. Incorporation of more pharmacokinetic and mechanistic data into the risk assessment process, as well as discussions between risk assessors and the research community to identify research needs are essential in reducing uncertainty factors. 相似文献
183.
184.
Abdel Samie Elewa 《Hydrobiologia》1985,128(3):249-254
The cyclic annual flood reaching Aswan High Dam Reservoir, results in a gradual increase in water level. However, the impacts of this incoming water mass are not merely the increase in water level, but also change the physical and chemical characteristics of the reservoir. The flood water coming from the south is rich in suspended matter, which gradually sediment to the bottom. The highest values of total dissolved solids and electrical conductance can be measured just in front of the edge of the flood. 相似文献
185.
Roots and aerial shoots ofZygophyllum coccineum L.,Z. album L. andZ. dumosum Boiss were extracted with solvents of increasing polarity and tested against spore germination ofVerticellium albo-atrum andFusarium oxysporum f.sp.lycopersici. The effectiveness of each extract depends on the solvent, plant species, organ and test fungus. Petroleum ether extracts
were ineffective as fungistatics while the methanol extracts possessed a high inhibitory effect toward spore germination suppression,
depending on the fungus and plant species. Water or ethyl acetate root extracts ofZ. album caused a marked suppression of spore germination of the test fungi. Six saponins were isolated from the effective extracts
on silica gel and Sephadex columns. They were identified by acid hydrolysis, alkaline saponification, IR and FAB MS. Quinovic
acid was the dominant aglycone. Kaempferol was isolated from the flavonoid fraction ofZ. dumosum for the first time. Some of the isolated saponins and kaempferol provided successful control against the test plant pathogens
under greenhouse experiment when used as seed treatment. 相似文献
186.
The influence of mounting and ejaculation on the FSH, LH and testosterone secretory patterns was studied in three azoospermic (including one 61 XXY; one Sertoli-cell-only Syndrome and one secretory-excretory azoospermic) and three control normospermic bulls. Sexual activity did not result in any alteration in the release of these three hormones. There was no difference between the secretory patterns before and after ejaculation in the two classes of bulls. One of the main features was the elevated concentrations of FSH in the bull with Klinefelter's Syndrome, but the mounting test did not result in any significant effect on this concentration. The LH and testosterone patterns were similar for all individuals. From these results, it can be concluded that the mounting test applied under these experimental conditions had no effect on the pituitary-gonadal axis in bulls characterized by either impairment of spermatogenesis or normal semen production. 相似文献
187.
188.
Drought stress (DS) is one of the most critical environmental abiotic stresses for wheat production in the arid environments. Selection of high-yielding genotypes tolerant to DS can play a significant role in mitigation the negative impacts associated with DS. In the present study, generation means analysis (GMA) was used to study the performance of two crosses under well irrigation (WI) and deficit irrigation [cross I (Line 44 × Shandweel-1) and cross II (Line 20 × Sakha 93)]. Significant differences were observed for days to heading (DH), days to maturity (DM), plant height (PH), spike length (SL), number of spikes per plant (NS/P), number of grains per spike (NG/S), thousand-grain weight (TGW), grain yield per plant (GY/P), and proline content (PC) in the six populations of the two crosses within each irrigation level. Cross II had early maturity and the highest PC, NS/P, TGW, and GY/P regardless of the irrigation level. Cross I showed positive significant relative heterosis and heterobeltiosis for GY/P under the two irrigation levels. The inheritance of characters of cross I revealed additive, dominant, and epistatic effects, which varied with trait and stress. Additive genetic effects predominated in DH, SL, and PC, while non- additive were found in DM, NS/P, NG/S, and GY/P. Narrow-sense heritability estimates (h2n) were high for DH and PC, moderate to high for PH and SL, moderate for DM, NG/S, NS/P, and TGW, and low for GY/P. Based on different drought indices the populations BC1, BC2, F1, and P1 of cross II and BC1 of cross I were more tolerant to drought stress. Therefore, PC, TGW and DH can be used as selection indicators to improve wheat for drought tolerance in early generations and other yield components traits in late generations. The second cross (Line 20 × Sakha 93) shows promise and is of interest to a drought tolerance breeding program, where wheat breeders can use recombinant breeding strategies to construct desirable drought stress genes. Correlation and path coefficient revealed that TGW and PC were the main contributor in grain yield in both environments. 相似文献
189.
Omaima M. Abdelhafez Eman Y. Ahmed Nehad A. Abdel Latif Reem K. Arafa Zakaria Y. Abd Elmageed Hamed I. Ali 《Bioorganic & medicinal chemistry》2019,27(7):1308-1319
Two new series of furochromone and benzofuran derivatives were designed, synthesized and evaluated for their in vitro anticancer activity against MCF-7 and MDA231 breast cancer cell lines. Compounds 5, 6, 7, 9, 15a, 16, 17a and 18 exhibited the best antiproliferative activities with IC50 values ranging from 1.19 to 2.78?µM against MCF-7 superior to lapatinib as reference standard (IC50; 4.69?µM). Compounds 15a and 18 revealed significant cytotoxic activity against MCF-7 and MDA231, therefore their inhibitory potencies against p38α MAP kinase were evaluated. Remarkably they exhibited significant IC50 of 0.04?µM comparable to SB203580 (IC50; 0.50?µM) as a reference standard. These promising results of cytotoxic activity and significant inhibition of p38α MAP kinase, were confirmed by exploring the effect of benzofuran derivative (18) on the apoptotic induction and cell cycle progression of MCF-7 cell line. Compound 18 induced preG1 apoptosis and cell growth arrest at G2/M phase preventing the mitotic cycle. Moreover it activated the caspase-7 which executes apoptosis. Molecular docking study was carried out using GOLD program to predict the mode of binding interaction of the synthesized compounds into the target p38α MAPK. Additionally, the physicochemical properties and ADME parameters of compound 18 were examined in silico to investigate its drug-likeness. 相似文献
190.
Rania A. A. Salama Rania M. Abdelsalam O. M. E. Abdel‐Salam Mahmoud M. khattab Neveen A. Salem Zakaria A. El‐Khyat Fatma A. Morsy Ezz‐El Din S. Eldenshary 《Journal of biochemical and molecular toxicology》2019,33(3)
The current study aimed to evaluate the role of cannabinoid receptors in the regulation of gastric acid secretion and oxidative stress in gastric mucosa. To fulfill this aim, gastric acid secretion stimulated with histamine (5 mg/kg, subcutaneous [SC]), 2‐deoxy‐ d ‐glucose (D‐G) (200 mg/kg, intravenous) or ‐carbachol (4 μg/kg, SC) in the 4‐hour pylorus‐ligated rats. The CB1R agonist ( N‐arachidonoyl dopamine, 1 mg/kg, SC) inhibited gastric acid secretion stimulated by D‐G and carbachol but not in histamine, reduced pepsin content, and increased mucin secretion. Furthermore, it decreased malondialdehyde (MDA) and nitric oxide (NO) contents with an increase in glutathione (GSH) and paraoxonase 1 (PON‐1). Meanwhile, CB2R antagonist (AM630, 1 mg/kg, SC) inhibited gastric acid secretion stimulated by D‐G and reduced MDA and NO contents with an increase in GSH and PON‐1. Meanwhile, CB1R antagonist rimonabant or CB2R agonist GW 405833 had no effect on stimulated gastric acid secretion. Therefore, both CB1R agonist and CB2R antagonist may exert antisecretory and antioxidant potential in the stomach. 相似文献