全文获取类型
收费全文 | 121篇 |
免费 | 9篇 |
专业分类
130篇 |
出版年
2022年 | 2篇 |
2021年 | 4篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 4篇 |
2015年 | 1篇 |
2013年 | 10篇 |
2012年 | 7篇 |
2011年 | 9篇 |
2010年 | 7篇 |
2009年 | 7篇 |
2008年 | 13篇 |
2007年 | 8篇 |
2006年 | 8篇 |
2005年 | 3篇 |
2004年 | 10篇 |
2003年 | 5篇 |
2002年 | 7篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 4篇 |
1998年 | 1篇 |
1995年 | 5篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有130条查询结果,搜索用时 15 毫秒
51.
Mattson RJ Denhart DJ Catt JD Dee MF Deskus JA Ditta JL Epperson J Dalton King H Gao A Poss MA Purandare A Tortolani D Zhao Y Yang H Yeola S Palmer J Torrente J Stark A Johnson G 《Bioorganic & medicinal chemistry letters》2004,14(16):4245-4248
The present studies have identified a series of aminotriazines as novel 5-HT(7) receptor antagonists. Compounds 10 and 17 have high affinity for the 5-HT(7) receptor and do not bind to either the 5-HT(2C) or 5-HT(6) receptors. These compounds produce no agonist effects by themselves, and shift the dose-response curve of 5-CT to the right in the manner of an antagonist. 相似文献
52.
53.
Lee Y Grill S Sanchez A Murphy-Ryan M Poss KD 《Development (Cambridge, England)》2005,132(23):5173-5183
During appendage regeneration in urodeles and teleosts, tissue replacement is precisely regulated such that only the appropriate structures are recovered, a phenomenon referred to as positional memory. It is believed that there exists, or is quickly established after amputation, a dynamic gradient of positional information along the proximodistal (PD) axis of the appendage that assigns region-specific instructions to injured tissue. These instructions specify the amount of tissue to regenerate, as well as the rate at which regenerative growth is to occur. A striking theme among many species is that the rate of regeneration is more rapid in proximally amputated appendages compared with distal amputations. However, the underlying molecular regulation is unclear. Here, we identify position-dependent differences in the rate of growth during zebrafish caudal fin regeneration. These growth rates correlate with position-dependent differences in blastemal length, mitotic index and expression of the Fgf target genes mkp3, sef and spry4. To address whether PD differences in amounts of Fgf signaling are responsible for position-dependent blastemal function, we have generated transgenic fish in which Fgf receptor activity can be experimentally manipulated. We find that the level of Fgf signaling exhibits strict control over target gene expression, blastemal proliferation and regenerative growth rate. Our results demonstrate that Fgf signaling defines position-dependent blastemal properties and growth rates for the regenerating zebrafish appendage. 相似文献
54.
55.
We report the existence of two distinct sublineages of avian metapneumovirus (MPV) subtype C, a virus which has caused serious economic loss in commercial turkey farms in the United States. This subtype is closely related to human MPV, infects multiple avian species, and is globally distributed. The evolutionary rates of this virus are estimated to be 1.3 × 10−3 to 7 × 10−3 substitutions per site per year, and coalescent estimates place its emergence between 1991 and 1996. The four genes examined show a concordant demographic pattern which is characterized by a rapid increase in population size followed by stable population grown until the present. 相似文献
56.
Male-biased dispersal is a common trait in mammals, including carnivores, but its genetic consequences at the population level have been rarely considered for solitary species. We used long-term genetic data from cougars (Puma concolor) in and around Yellowstone National Park to test predictions based on differences in dispersal behaviour among males and females. Consistent with frequent long-distance dispersal of males, we found support for our prediction of less than expected allele sharing in pair-wise comparisons. In contrast, female residents present at the same time and females separated by few generations failed to share more alleles than expected, contrary to our predictions based on limited female dispersal. However, we find that genetic contributions of females with higher reproductive success were still noticeable in subsequent generations, consistent with female offspring showing fidelity to their natal area. These results highlight the importance of male dispersal for inbreeding avoidance, but do not indicate that short-distance dispersal or philopatry in female cougars results in spatial clustering of related individuals. 相似文献
57.
Julius Kiwanuka Joel Bazira Juliet Mwanga Dickson Tumusiime Eunice Nyesigire Nkangi Lwanga Benjamin C. Warf Vivek Kapur Mary Poss Steven J. Schiff 《PloS one》2013,8(8)
Neonatal sepsis in the developing world is incompletely characterized. We seek to characterize the microbial spectrum involved in sepsis and determine the role of maternal transmission by comparing organisms that can be cultured from septic newborn infants and their mothers. From 80 consecutive mother-infant pairs meeting clinical criteria for neonatal sepsis, we collected infant blood and spinal fluid, and maternal blood and vaginal specimens. Identifiable bacteria were recovered from the blood in 32.5% of infants, and from 2.5% of cerebrospinal fluid cultures, for a total of 35% recoverable putative causative agents. Bacteria recovered from vaginal specimens were not concordant with those recovered from infants. Similarly there was no concordance of bacteria recovered from blood and cerebrospinal fluid. We conclude that relying on traditional bacterial culture techniques does not adequately delineate the role of maternal versus environmental sources of neonatal sepsis in this setting. More sensitive molecular approaches will be needed to properly characterize the maternal and environmental microbial community involved in neonatal sepsis in such developing countries. 相似文献
58.
The purpose of this study, conducted in a small, impoverished Hispanic community on the Texas-Mexico border, was to evaluate the level of participation in a bilingual spay/neuter program offered free of charge to residents with companion animals. Prior to the sterilization project, approximately 11% of dogs and about 27% of cats with guardians underwent surgical sterilization. Over an 8-month period, the spay/neuter program sterilized about 47% of dogs and 38% of cats who had guardians in the community. In spite of residents' early reluctance to neuter their dogs, the project sterilized nearly equal numbers of male and female dogs (200 male; 201 female). 相似文献
59.
Harikrishnan LS Kamau MG Wan H Inghrim JA Zimmermann K Sang X Mastalerz HA Johnson WL Zhang G Lombardo LJ Poss MA Trainor GL Tokarski JS Lorenzi MV You D Gottardis MM Baldwin KF Lippy J Nirschl DS Qiu R Miller AV Khan J Sack JS Purandare AV 《Bioorganic & medicinal chemistry letters》2011,21(5):1425-1428
SAR studies of pyrrolo[1,2-f]triazines as JAK2 inhibitors is presented. Achieving JAK2 inhibition selectively over JAK3 is discussed. 相似文献
60.
T. E. Smith S. R. Grattan C. M. Grieve J. A. Poss A. E. Läuchli D. L. Suarez 《Plant and Soil》2013,370(1-2):541-554