全文获取类型
收费全文 | 153篇 |
免费 | 11篇 |
国内免费 | 2篇 |
专业分类
166篇 |
出版年
2023年 | 1篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 6篇 |
2016年 | 1篇 |
2015年 | 3篇 |
2014年 | 5篇 |
2013年 | 14篇 |
2012年 | 7篇 |
2011年 | 11篇 |
2010年 | 17篇 |
2009年 | 11篇 |
2008年 | 8篇 |
2007年 | 6篇 |
2006年 | 8篇 |
2005年 | 7篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 6篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1988年 | 4篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有166条查询结果,搜索用时 15 毫秒
111.
O. HAMARSHEH W. PRESBER M.‐R. YAGHOOBI‐ERSHADI A. AMRO A. AL‐JAWABREH S. SAWALHA A. AL‐LAHEM M. L. DAS S. GUERNAOUI N. SERIDI R. C. DHIMAN Y. HASHIGUCHI J. GHRAB M. HASSAN G. SCHÖNIAN 《Medical and veterinary entomology》2009,23(1):69-77
Abstract Multi‐locus microsatellite typing (MLMT) has been employed to infer the population structure of Phlebotomus papatasi (Scopoli) (Diptera: Psychodidae) sandflies and assign individuals to populations. Phlebotomus papatasi sandflies were collected from 35 sites in 15 countries. A total of 188 P. papatasi individuals were typed using five microsatellite loci, resulting in 113 different genotypes. Unique microsatellite signatures were observed for some of the populations analysed. Comparable results were obtained when the data were analysed with Bayesian model and distance‐based methods. Bayesian statistic‐based analyses split the dataset into two distinct genetic clusters, A and B, with further substructuring within each. Population A consisted of five subpopulations representing large numbers of alleles that were correlated with the geographical origins of the sandflies. Cluster B comprised individuals collected in the Middle East and the northern Mediterranean area. The subpopulations B1 and B2 did not, however, show any further correlation to geographical origin. The genetic differentiation between subpopulations was supported by F statistics showing statistically significant (Bonferroni‐corrected P < 0.005) values of 0.221 between B2 and B1 and 0.816 between A5 and A4. Identification of the genetic structure of P. papatasi populations is important for understanding the patterns of dispersal of this species and to developing strategies for sandfly control. 相似文献
112.
Bone is a complex tissue whose composition and properties vary with age, sex, diet, tissue type, health and disease. In this review, we demonstrate how infrared spectroscopy and infrared spectroscopic imaging can be applied to the study of these variations. A specific example of mice with Fabry disease (a lipid storage disease) is presented in which it is demonstrated that the bones of these young animals, while showing typical spatial variation in mineral content, mineral crystal size, and collagen maturity, do not differ from the bones of age- and sex-matched wild type animals. 相似文献
113.
In the present study, bee colonies were smoked with tobacco smoke in order to evaluate the monthly changes in the numbers of worker bees, the infestation rates of worker bees and queens with bee lice, and the annual average honey production per colony. In July of each year, 12 colonies were smoked with tobacco smoke; the remaining hives not smoked with tobacco smoke served as the control. The results indicated that the applications of tobacco smoke during July gave rise to an impressive reduction in the Braula infestation rate on workers (below 1.8%) and reduced the amount of bee lice on the queen to zero throughout the 2–3 months following smoke treatment. In the colonies not treated with smoke, the Braula infestation rates on worker bees started to increase in May and continued to increase constantly during the rest of year, reaching maximum infestation rates of 28.2% and 33.8% in December, with an average of 15 and 17 lice per queen in November in the first and second years, respectively. Worker bee populations peaked in April and July of each year in both treatments. The average honey production per colony was significantly higher in the colonies treated with smoke than those that were not for the first and second years. In conclusion, early summer months may be the crucial time to smoke the colonies with tobacco smoke in order to keep bee lice at low levels for the remaining seasons. 相似文献
114.
Roslyn Boyd Leanne Sakzewski Jenny Ziviani David F Abbott Radwa Badawy Rose Gilmore Kerry Provan Jacques-Donald Tournier Richard AL Macdonell Graeme D Jackson 《BMC neurology》2010,10(1):4
Background
Congenital hemiplegia is the most common form of cerebral palsy (CP) accounting for 1 in 1300 live births. These children have limitations in capacity to use the impaired upper limb and bimanual coordination deficits which impact on daily activities and participation in home, school and community life. There are currently two diverse intensive therapy approaches. Traditional therapy has adopted a bimanual approach (BIM training) and recently, constraint induced movement therapy (CIMT) has emerged as a promising unimanual approach. Uncertainty remains about the efficacy of these interventions and characteristics of best responders. This study aims to compare the efficacy of CIMT to BIM training to improve outcomes across the ICF for school children with congenital hemiplegia. 相似文献115.
Jason AL Jeffery Peter A Ryan Scott A Lyons Paula T Thomas Brian H Kay 《Australian Journal of Entomology》2002,41(4):329-338
Abstract We used a network of 20 carbon dioxide- and octenol-supplemented light traps to sample adult mosquitoes throughout Russell Island in southern Moreton Bay, south-east Queensland. Between February and April 2001, an estimated 1365 564 adult female mosquitoes were collected. In contrast to an average catch of 9754 female mosquitoes per trap night on Russell Island, reference traps set on Macleay Island and on the mainland returned average catches of 3172 and 222, respectively. On Russell Island, Ochlerotatus vigilax (Skuse), Coquillettidia linealis (Skuse), Culex annulirostris Skuse and Verrallina funerea (Theobald), known or suspected vectors of Ross River (RR) and/or Barmah Forest (BF) viruses, comprised 89.6% of the 25 taxa collected. When the spatial distributions of the above species were mapped and analysed using local spatial statistics, all were found to be present in highest numbers towards the southern end of the island during most of the 7 weeks. This indicated the presence of more suitable adult harbourage sites and/or suboptimal larval control efficacy. As immature stages and the breeding habitat of Cq. linealis are as yet undescribed, this species in particular presents a considerable impediment to proposed development scenarios. The method presented here of mapping the numbers of mosquitoes throughout a local government area allows specific areas that have high vector numbers to be defined. 相似文献
116.
117.
Conditional inactivation of the CXCR4 receptor in osteoprecursors reduces postnatal bone formation due to impaired osteoblast development 总被引:1,自引:0,他引:1
Zhu W Liang G Huang Z Doty SB Boskey AL 《The Journal of biological chemistry》2011,286(30):26794-26805
Cysteine (C)-X-C motif chemokine receptor 4 (CXCR4), the primary receptor for stromal cell-derived factor-1 (SDF-1), is involved in bone morphogenic protein 2 (BMP2)-induced osteogenic differentiation of mesenchymal progenitors. To target the in vivo function of CXCR4 in bone and explore the underlying mechanisms, we conditionally inactivated CXCR4 in osteoprecursors by crossing osterix (Osx)-Cre mice with floxed CXCR4 (CXCR4(fl/fl)) mice to generate knock-outs with CXCR4 deletion driven by the Osx promoter (Osx::CXCR4(fl/fl)). The Cre-mediated excision of CXCR4 occurred exclusively in bone of Osx::CXCR4(fl/fl) mice. When compared with littermate controls, Osx::CXCR4(fl/fl) mice developed smaller osteopenic skeletons as evidenced by reduced trabecular and cortical bone mass, lower bone mineral density, and a slower mineral apposition rate. In addition, Osx::CXCR4(fl/fl) mice displayed chondrocyte disorganization in the epiphyseal growth plate associated with decreased proliferation and collagen matrix syntheses. Moreover, mature osteoblast-related expression of type I collagen α1 and osteocalcin was reduced in bone of Osx::CXCR4(fl/fl) mice versus controls, suggesting that CXCR4 deficiency results in arrested osteoblast progression. Primary cultures for osteoblastic cells derived from Osx::CXCR4(fl/fl) mice also showed decreased proliferation and impaired osteoblast differentiation in response to BMP2 or BMP6 stimulation, and suppressed activation of intracellular BMP receptor-regulated Smads (R-Smads) and Erk1/2 was identified in CXCR4-deficient cells and bone tissues. These findings provide the first in vivo evidence that CXCR4 functions in postnatal bone development by regulating osteoblast development in cooperation with BMP signaling. Thus, CXCR4 acts as an endogenous signaling component necessary for bone formation. 相似文献
118.
Background
HTLV-I infection has been linked to lung pathology and HTLV-II has been associated with an increased incidence of pneumonia and acute bronchitis. However it is unknown whether HTLV-I or -II infection alters pulmonary function.Methods
We performed pulmonary function testing on HTLV-I, HTLV-II and HTLV seronegative subjects from the HTLV outcomes study (HOST), including vital capacity (VC), forced expiratory volume in one second (FEV1), and diffusing lung capacity for carbon monoxide (DLCO) corrected for hemoglobin and lung volume. Multivariable analysis adjusted for differences in age, gender, race/ethnicity, height and smoking history.Results
Mean (standard deviation) pulmonary function values among the 257 subjects were as follows: FVC = 3.74 (0.89) L, FEV1 = 2.93 (0.67) L, DLCOcorr = 23.82 (5.89) ml/min/mmHg, alveolar ventilation (VA) = 5.25 (1.20) L and DLCOcorr/VA = 4.54 (0.87) ml/min/mmHg/L. There were no differences in FVC, FEV1 and DLCOcorr/VA by HTLV status. For DLCOcorr, HTLV-I and HTLV-II subjects had slightly lower values than seronegatives, but neither difference was statistically significant after adjustment for confounding.Conclusions
There was no difference in measured pulmonary function and diffusing capacity in generally healthy HTLV-I and HTLV-II subjects compared to seronegatives. These results suggest that previously described HTLV-associated abnormalities in bronchoalveolar cells and fluid may not affect pulmonary function. 相似文献119.
Characterization of phosphorus fractions in the sediments of a tropical intertidal mangrove ecosystem 总被引:2,自引:0,他引:2
Solid phases of phosphorus fractions in the surface and core sediments were studied to understand the biogeochemical cycling
and bioavailability of phosphorus in the Pichavaram intertidal mangrove sediments of India. Total P in surface and core sediments
ranged between 451–552 and 459–736 μg g−1 respectively and Fe bound P was the dominant fraction. Low levels of Fe bound P in the mangrove zone than the two estuarine
zones may be because of high salinity inhibition of phosphate adsorption onto the Fe-oxides/hydroxides. Post-depositional
reorganization of P was observed in surface sediments, converting organic P and Fe bound P into the authigenic P. High levels
of organic P in the mangrove zone is primarily due to intensive cycling and degradation of organic matter and adsorption of
phosphate on the organic molecules. The burial rates and regeneration efficiency of P in the intertidal mangrove ecosystem
ranged from 5.41 to 7.27 μmol P cm−2 year−1 and 0.122 to 0.233 μmol P cm−2 year−1, respectively. High burial efficiency (≈99%) of P proves the earlier observation of limiting nature of P for the biological
productivity. Further, bioavailable P (exchangeable P + Fe bound P + organic P) constituted a considerable proportion of sedimentary
P pool of which an average accounted for 55 and 50% in surface and core sediments respectively. The results indicate that
significant amount of P is locked in sediments in the form of authigenic P and detrital P which makes P as a limiting nutrient
for the biological productivity. 相似文献
120.
不孕不育患者解脲脲原体菌株血清型别的检测 总被引:2,自引:0,他引:2
本文以解脲脲原体标准菌株1-14型免疫家获得UU1-14型抗血清。用IDT法对48株自不孕不育患者分离的地方株作分型试验。结果在1.2.4.5.6.7.8和12血八个清型中出现强阳性反应,其中4型最多。另有4株混合型。对四种血清型无反应。 相似文献