首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   126篇
  免费   13篇
  国内免费   1篇
  2023年   1篇
  2022年   1篇
  2021年   2篇
  2020年   5篇
  2019年   3篇
  2018年   6篇
  2017年   6篇
  2016年   4篇
  2015年   10篇
  2014年   8篇
  2013年   15篇
  2012年   13篇
  2011年   11篇
  2010年   8篇
  2009年   11篇
  2008年   7篇
  2007年   4篇
  2006年   1篇
  2005年   3篇
  2004年   6篇
  2003年   3篇
  2002年   4篇
  2001年   1篇
  1999年   1篇
  1994年   1篇
  1993年   1篇
  1980年   1篇
  1977年   1篇
  1972年   1篇
  1971年   1篇
排序方式: 共有140条查询结果,搜索用时 15 毫秒
131.
132.
Systematic Parasitology - The male and subgravid female of Philometra serranellicabrillae Janiszewska, 1949 (Philometridae) collected from the gonads of Serranus cabrilla (Linnaeus) (Serranidae)...  相似文献   
133.
Although aging is a major risk factor for most types of cancers, it is barely studied in this context. The transmembrane protein PLA2R1 (phospholipase A2 receptor) promotes cellular senescence, which can inhibit oncogene-induced tumor initiation. Functions and mechanisms of action of PLA2R1 during aging are largely unknown. In this study, we observed that old Pla2r1 knockout mice were more prone to spontaneously develop a wide spectrum of tumors compared to control littermates. Consistently, these knockout mice displayed increased Parp1, a master regulator of DNA damage repair, and decreased DNA damage, correlating with large human dataset analysis. Forced PLA2R1 expression in normal human cells decreased PARP1 expression, induced DNA damage and subsequent senescence, while the constitutive expression of PARP1 rescued cells from these PLA2R1-induced effects. Mechanistically, PARP1 expression is repressed by a ROS (reactive oxygen species)-Rb-dependent mechanism upon PLA2R1 expression. In conclusion, our results suggest that PLA2R1 suppresses aging-induced tumors by repressing PARP1, via a ROS–Rb signaling axis, and inducing DNA damage and its tumor suppressive responses.Subject terms: Cancer, Mechanisms of disease, DNA damage and repair, Ageing  相似文献   
134.
Copy number changes of subtelomeric regions are a common cause of mental retardation, occurring in approximately 5% of mentally retarded patients. New molecular techniques allow the identification of subtelomeric microduplications. We report a Tunisian family of three sisters with moderate mental retardation, facial dysmorphism, cardiopathy, and bilateral clinodactyly of the third and fourth toes, explored by MLPA, showing the same associated microduplications, 15q and Xq, without a concurrent deletion.  相似文献   
135.
Neuromodulation plays important and stage‐dependent roles in regulating locomotor central pattern (CPG) outputs during vertebrate motor system development. Dopamine, serotonin and nitric oxide are three neuromodulators that potently influence CPG outputs in the development of Xenopus frog tadpole locomotion. However, their roles switch from predominantly inhibitory early in development to mainly excitatory at later stages. In this review, we compare the stage‐dependent switching in neuromodulation in Xenopus with other vertebrate systems, notably the mouse and the zebrafish, and highlight features that appear to be phylogenetically conserved.  相似文献   
136.
Melone, G., Lora Lamia Donin, C., Cotelli, F. 1980. The paraspermatic cell (atypical spermatozoon) of Prosobranchia: a comparative ultrastructural study. (Institute of Zoology, University of Milan, Milano, Italy.) — Acta zool. (Stockh.) 61(4): 191–201. The ultrastructure of the paraspermatic cells (atypical spermatozoa) in the male genital tracts of nine species of marine Prosobranchia is described. These cells derive from the same germinal line as the typical spermatozoa, and seem to be homogeneous in their general constitution. In all nine species the paraspermatic cells are characterized by the presence of granules. Axonemes are present in all except one species. Various kinds of paraspermatic cell movements are described; three of the nine species have not yet demonstrated any motility. The significance and the function of paraspermatic cells are discussed.  相似文献   
137.
138.
The performance values of available techniques used in serodiagnosis of toxoplasmosis are satisfactory but they raise problems of equivocal and discordant results for very low IgG titers. Recently marketed, LDBio-Toxo II IgG Western blot (IB) showed an excellent correlation with the dye test. We estimated the proportion of equivocal and discordant results between the enzyme immunoassay Platelia Toxo IgG (EIA-IgG) and fluorescent antibody test (FAT) and assessed the usefulness of the IB as a confirmatory test. Out of 2,136 sera collected from pregnant women, 1,644 (77.0%) tested unequivocally positive and 407 (19.0%) were negative in both EIA-IgG and FAT. The remaining 85 (4%) sera showed equivocal or discordant results. Among them, 73 (85.9%) were positive and 12 (14.1%) were negative in IB. Forty-one (89.1%) equivocal sera in EIA-IgG and 46 (86.8%) equivocal sera in FAT were positive in IB. Reducing the cut-off values of both screening techniques improved significantly their sensitivity in detecting very low IgG titers at the expense of their specificity. In conclusion, equivocal results in routine-used techniques and their discordance in determination of the immune status in pregnancy women were not uncommon. IB test appeard to be highly useful in these situations as a confirmatory technique.  相似文献   
139.
Table olive processing wastewaters constitute a dangerous environmental problem in the Mediterranean countries because of their large volumes, high organic matter and salt concentration. The quantity and the characteristics of wastewaters produced, and thus, their environmental impact, varied depending on the season, varieties, soil and process employed. Several chemicals, biological and combined technologies have proven effective at bringing down organic pollution and toxicity of these effluents. Advanced oxidation processes have recognized as highly efficient treatments for the degradation of organic matter. Nonetheless, complete mineralization is generally expensive without salt removal. Biological processes are the most environmentally compatible and least-expensive treatment methods, but these operations do not always provide satisfactory results. This article surveys the current available technologies and suggests an effective, cheaper alternative for the recycling and the valorization of green table olives wastewaters.  相似文献   
140.
Porcellio albinus is a nocturnal species inhabiting xeric habitats in Tunisia. Size distribution, population dynamics, breeding activity, fecundity, fertility, reproductive allocation (RA), and life span were studied to establish the reproductive strategy of a population of this species in the sandy coastal area of Zarat. Monthly sampling was undertaken between July 2012 and November 2013. The overall sex-ratio of P. albinus was female biased. The relative abundance of adults, much more representative than that of juveniles, might be the consequence of the absence of specimens less than 8 mm in size in all samples collected outside the burrows at night. Reproduction is seasonal in P. albinus with two breeding seasons, the first one from March to June and the second in September. Five cohorts were recruited per year, four during the spring and one during the fall. The number of eggs per female ranged from 13 to 67 and was positively correlated with female body size. Fertility varied from 5 to 39 mancae. Compared to other xeric species, RA was low to produce a brood, but high to release a single manca. The results provide a better understanding of the reproductive behavior of this terrestrial isopod, living under severe environmental conditions.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号