全文获取类型
收费全文 | 454篇 |
免费 | 32篇 |
出版年
2022年 | 11篇 |
2021年 | 6篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 17篇 |
2017年 | 16篇 |
2016年 | 16篇 |
2015年 | 12篇 |
2014年 | 19篇 |
2013年 | 38篇 |
2012年 | 27篇 |
2011年 | 27篇 |
2010年 | 23篇 |
2009年 | 20篇 |
2008年 | 18篇 |
2007年 | 26篇 |
2006年 | 18篇 |
2005年 | 18篇 |
2004年 | 19篇 |
2003年 | 28篇 |
2002年 | 20篇 |
2001年 | 6篇 |
2000年 | 9篇 |
1999年 | 7篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 6篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 6篇 |
1991年 | 1篇 |
1990年 | 6篇 |
1989年 | 9篇 |
1988年 | 4篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 6篇 |
1983年 | 4篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1964年 | 1篇 |
1962年 | 2篇 |
排序方式: 共有486条查询结果,搜索用时 31 毫秒
31.
Kusum Lata Singh Arvind Kumar Ashok Kumar 《World journal of microbiology & biotechnology》1998,14(5):777-779
A strain of Bacillus cereus was isolated from a detergent-polluted pond. This strain showed growth with exceedingly high concentration of both anionic and non-ionic detergents. Detergent such as SDS was rapidly taken up by the cells and degraded to dodecan-1-ol by the enzyme alkylsulphatase. 相似文献
32.
Sudesh Raj Sharma Smith Giri Utsav Timalsina Sanjiv Sudarshan Bhandari Bikash Basyal Kusum Wagle Laxman Shrestha 《PloS one》2015,10(4)
Birth weight of a child is an important indicator of its vulnerability for childhood illness and chances of survival. A large number of infant deaths can be averted by appropriate management of low birth weight babies and prevention of factors associated with low birth weight. The prevalence of low birth weight babies in Nepal is estimated to be about 12-32%.Our study aimed at identifying major determinants of low birth weight among term babies in Nepal. A hospital-based retrospective case control study was conducted in maternity ward of Tribhuvan University Teaching Hospital from February to July 2011. A total of 155 LBW babies and 310 controls were included in the study. Mothers admitted to maternity ward during the study period were interviewed, medical records were assessed and anthropometric measurements were done. Risk factors, broadly classified into proximal and distal factors, were assessed for any association with birth of low-birth weight babies. Regression analysis revealed that a history of premature delivery (adjusted odds ratio; aOR5.24, CI 1.05-26.28), hard physical work during pregnancy (aOR1.48, CI 0.97-2.26), younger age of mother (aOR1.98, CI 1.15-3.41), mothers with haemoglobin level less than 11gm/dl (aOR0.51, CI0.24-1.07) and lack of consumption of nutritious food during pregnancy (aOR1.99, CI 1.28-3.10) were significantly associated with the birth of LBW babies. These factors should be addressed with appropriate measures so as to decrease the prevalence of low birth weight among term babies in Nepal. 相似文献
33.
Background
Multiple sclerosis (MS) is less prevalent among Indians when compared to white populations. Genetic susceptibility remaining the same it is possible that environmental associations may have a role in determining disease prevalence.Aims
To determine whether childhood infections, vaccination status, past infection with Helicobacter pylori (H.pylori), diet, socioeconomic and educational status were associated with MS.Material and Methods
139 patients and 278 matched control subjects were selected. A validated environmental exposure questionnaire was administered. Estimation of serum H.pylori IgG antibody was done by ELISA. Patients and controls were genotyped for HLA-DRB1*15:01.Results
In our cohort a significant association was seen with measles (p <0.007), vegetarian diet (p < 0.001, higher educational status (p <0.0001) and urban living (p <0.0001). An inverse relationship was seen with H.Pylori infection and MS (p <0.001). Measles infection (OR 6.479, CI 1.21- 34.668, p< 0.029) and high educational status (OR 3.088, CI 1.212- 7.872, p< 0.018) were significant risk factors associated with MS. H.pylori infection was inversely related to MS (OR 0. 319, CI 0.144- 0.706, p <0.005).Conclusions
Environmental influences may be important in determining MS prevalence. 相似文献34.
Pandey Anita Dhakar Kusum Sharma Avinash Priti Payal Sati Priyanka Kumar Bhavesh 《Annals of microbiology》2015,65(2):809-816
Twenty-eight bacterial cultures, isolated from hot springs in Uttarakhand, were characterized with particular reference to their wide temperature and pH tolerance and production of enzymes in the thermophilic range. All the bacterial isolates were observed as Gram-positive or variable rods in varied arrangement. Bacterial isolates exhibited tolerance to a wide temperature range (20–80 °C), from mesophilic (+11° to +45 °C) to thermophilic (+46 ° to +75 °C); few almost reached the hyperthermophilic range (+76 °C). The isolates also tolerated a wide pH range (4–14) and moderate salt concentration. The optimum growth of the bacterial isolates was observed at 55 °C and 7 pH. Out of 28 isolates, 25 produced lipase, 25 amylase, 24 cellulase, 22 protease and 13 xylanase at 55 and 65 °C. Tolerance to a wide temperature and pH range and the production of enzymes in a thermophilic temperature range can be considered as indicators of ecological competence of these bacterial isolates for colonizing the high temperature environment. On the basis of 16S rDNA similarity, 20 bacterial isolates belonged to Bacillus licheniformis, five to Paenibacillus ehimensis and one each to Bacillus sonorensis, B. tequilensis, and Staphylococcus epidermidis. Besides variation in phenotypic characters, strains of B. licheniformis and P. ehimensis showed varying 16S rDNA similarity between 97–99 % and 95–99 %, respectively. Consideration of temperature preferences in classifying microorganisms on the basis of their minimum, maximum, and optimum growth requirements is also discussed. The study has ecological relevance in the context of colonization of high temperature environments by thermophilic bacteria. 相似文献
35.
Kirti Gupta Ritambhra Nada Kusum Joshi Minakshi Rohilla Rama Walia 《Mycopathologia》2010,170(5):357-360
Mucormycosis is an uncommon opportunistic infection by filamentous fungi that usually develops in immmunocompromised patients.
Most individuals have an underlying systemic disease, such as diabetes mellitus, malignancy, uraemia, burns, renal transplant
recipients and those on corticosteroid and immunosuppressive therapy. Many cases of primary renal zygomycosis with lungs serving
as the portal of entry have been reported from this region. We describe two autopsy cases of renal zygomycosis where bladder
appeared to be the portal of entry for the fungus. 相似文献
36.
van Duren BH Pandit H Beard DJ Zavatsky AB Gallagher JA Thomas NP Shakespeare DT Murray DW Gill HS 《Journal of biomechanics》2007,40(Z1):S31-S37
Newer designs of total knee arthroplasty (TKA), through the use of added degrees of constraint, attempt to provide a "guided motion" to restore more normal and predictable kinematics. Two such design philosophies are the posterior stabilised (PS) using a cam-post and the medial pivot (MP) concepts. Knee kinematics of 12 patients with a PS TKA, 13 subjects with a MP TKA and 10 normal subjects were compared. For kinematic assessment, patients underwent fluoroscopic assessment of the knee during a step-up exercise and deep knee bend. Fluoroscopic images were corrected for distortion and assessed using 3D model fitting to determine relative 3D motion, and a 2D method to measure the patellar tendon angle (PTA) as function of knee flexion. For the PS design the cam-post mechanism engaged between 70 degrees and 100 degrees flexion. Between extension and 50 degrees there was forward motion of the contact points. Beyond 60 degrees both condyles rolled moved posteriorly. The majority of the external rotation of the femur occurred between 50 degrees and 80 degrees . The PTA was lower than normal in extension and higher than normal in flexion. The MP exhibited no anterior movement throughout the rage of motion. The medial condyle moved minimally. The lateral contact point moved posteriorly from extension to flexion. The femur rotated externally throughout the range of flexion analysed. The PTA was similar to normal from extension to mid flexion and then higher than normal beyond to high flexion. The PS design fails to fully restrain paradoxical anterior movement and although the cam engages, it does not contribute significantly to overall rollback. The MP knee does not show significant anterior movement, the medial pivot concept appears to achieve near normal kinematics from extension to 50 degrees of knee flexion. However, the results show that at high flexion this design does not achieve normal knee kinematics. 相似文献
37.
Vajdos FF Hoth LR Geoghegan KF Simons SP LeMotte PK Danley DE Ammirati MJ Pandit J 《Protein science : a publication of the Protein Society》2007,16(5):897-905
Lasofoxifene is a new and potent selective estrogen receptor modulator (SERM). The structural basis of its interaction with the estrogen receptor has been investigated by crystallographic analysis of its complex with the ligand-binding domain of estrogen receptor alpha at a resolution of 2.0 A. As with other SERMs, lasofoxifene diverts the receptor from its agonist-bound conformation by displacing the C-terminal AF-2 helix into the site at which the LXXLL motif of coactivator proteins would otherwise be able to bind. Lasofoxifene achieves this effect by occupying the space normally filled by residue Leu 540, as well as by modulating the conformation of residues of helix 11 (His 524, Leu 525). A well-defined salt bridge between lasofoxifene and Asp 351 suggests that charge neutralization in this region of the receptor may explain the some of the antiestrogenic effects of lasofoxifene. The results suggest general features of ERalpha/SERM recognition, and add a new dimension to efforts to rationalize differences between the biological activity profiles exhibited by these important pharmacological agents. 相似文献
38.
Unreported yet massive deforestation driving loss
of endemic biodiversity in Indian Himalaya 总被引:1,自引:0,他引:1
M. K. Pandit Navjot S. Sodhi Lian Pin Koh Arun Bhaskar Barry W. Brook 《Biodiversity and Conservation》2007,16(1):153-163
Deforestation is a primary driver of biotic extinctions in the tropics. The impacts of deforestation in tropical biodiversity
hotspots are of particular concern because these regions contain high concentrations of globally endemic species. However,
the effects of large-scale deforestation on native biotas within the biodiversity hotspot of Himalaya remain poorly documented.
Here we report on an alarming trend of deforestation in the Indian Himalaya and project the likely consequential extinctions
of endemic taxa (species and subspecies) by 2100 across a broad range of taxonomic groups, including gymnosperms, angiosperms,
fishes, amphibians, reptiles, birds, and mammals. With the current level of deforestation, by 2100 only about 10% of the land
area of the Indian Himalaya will be covered by dense forest (>40% canopy cover)—a scenario in which almost a quarter of the
endemic species could be wiped out, including 366 endemic vascular plant taxa and 35 endemic vertebrate taxa. We also show
that inaccurate reporting of forest cover data by governmental institutions can result in underestimations of the biological
impacts of deforestation, as well as potential miscalculations in land-use decisions (e.g., the construction of hydroelectric
dams). Large-scale conservation efforts, including forest protection and reforestation, are urgently needed to avoid the impending
deforestation-driven biodiversity losses in the Himalaya. 相似文献
39.
Journal of Biological Physics - Protein–protein interaction in solution strongly depends on dissolved ions and solution pH. Interaction among globular protein (bovine serum albumin, BSA),... 相似文献
40.