全文获取类型
收费全文 | 254篇 |
免费 | 17篇 |
专业分类
271篇 |
出版年
2023年 | 2篇 |
2022年 | 14篇 |
2021年 | 18篇 |
2020年 | 10篇 |
2019年 | 12篇 |
2018年 | 15篇 |
2017年 | 12篇 |
2016年 | 12篇 |
2015年 | 15篇 |
2014年 | 12篇 |
2013年 | 25篇 |
2012年 | 25篇 |
2011年 | 16篇 |
2010年 | 10篇 |
2009年 | 12篇 |
2008年 | 11篇 |
2007年 | 13篇 |
2006年 | 2篇 |
2005年 | 6篇 |
2004年 | 3篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2000年 | 1篇 |
1999年 | 4篇 |
1998年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1978年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有271条查询结果,搜索用时 15 毫秒
81.
This paper examines age patterns of first marriage and motherhood and covariates of early marriage, delayed consummation of marriage and early motherhood in Nepal using data from the 2000 Nepal Adolescent and Young Adult Survey (NAYA). Both unmarried and married male and female youths (age 14-22) were included in the survey. The analysis is based on 2800 urban youths and 5075 rural youths with complete information on the variables examined. Proportional hazard models are used to estimate covariates of early marriage and early motherhood, and logistic regression models are used to estimate covariates of delayed consummation of marriage. The results show that early marriage and early motherhood are quite common among Nepalese women, especially in rural areas. Early marriage is much less common among men. Delayed consummation of marriage is common among very young brides, especially in rural areas. The main covariates associated with early marriage and early motherhood are respondent's education, region of residence and ethnicity. The main covariates of delayed consummation of marriage are age at first marriage, region of residence and ethnicity. The study highlights the need to focus on less educated female youths in the Terai region in order to reduce the reproductive and child health risks associated with early marriage and early childbearing. 相似文献
82.
Jessica Y. Franco Shree P. Thapa Zhiqian Pang Fatta B. Gurung Thomas W. H. Liebrand Danielle M. Stevens Veronica Ancona Nian Wang Gitta Coaker 《Molecular & cellular proteomics : MCP》2020,19(12):1936-1952
Highlights
- •HLB is the most devastating citrus disease associated with the pathogen CLas.
- •Proteases and peroxidases accumulated in plant vascular tissue after CLas infection.
- •Dynamic changes in serine protease activity occur across genotypes and environments.
83.
84.
Sundar Thapa Kiran K. Katakam Stig M. Thamsborg Helena Mejer 《Biocontrol Science and Technology》2015,25(7):756-767
Thick-shelled eggs of animal-parasitic ascarid nematodes can survive and remain infective in the environment for years. The present study evaluated a simple in vitro method and evaluation scheme to assess the relative effect of two species of soil microfungi, Pochonia chlamydosporia Biotype 10 and Purpureocillium lilacinum Strain 251 (Ascomycota: Hypocreales), on the development and survival of eggs of faecal origin of three ascarid species, Ascaridia galli (chicken roundworm), Toxocara canis (canine roundworm) and Ascaris suum (pig roundworm). Ascarid eggs were embryonated on water agar with or without a fungus, and the resulting viability of the eggs was evaluated on days 7, 14, 21, 28, 35 and 42 post exposure (pe) by observing eggs in situ. On days 7–42 pe, P. chlamydosporia had reduced the viability of A. galli and T. canis eggs by 64–86% and 26–67%. Corresponding reductions for P. lilacinum Strain 251 were only 15–29% and 4–28%. In contrast, A. suum eggs were extremely resistant to both fungi (2–4% reduction). The differences in results are likely due to different morphologies and chemistry of the egg shell of the three ascarid species. The current in vitro method and evaluation criteria allow for a simple, repeatable and non-invasive evaluation of the ovicidal effects of microfungi. This study demonstrates that P. chlamydosporia Biotype 10 may be utilised as a biocontrol agent to reduce A. galli and T. canis egg contamination of the environment. 相似文献
85.
Nagarajan Baskaran Govindarajan Kannan Uthrapathy Anbarasan Anisha Thapa Raman Sukumar 《Mammalian Biology》2013,78(6):470-481
Spatial information at the landscape scale is extremely important for conservation planning, especially in the case of long-ranging vertebrates. The biodiversity-rich Anamalai hill ranges in the Western Ghats of southern India hold a viable population for the long-term conservation of the Asian elephant. Through rapid but extensive field surveys we mapped elephant habitat, corridors, vegetation and land-use patterns, estimated the elephant population density and structure, and assessed elephant–human conflict across this landscape. GIS and remote sensing analyses indicate that elephants are distributed among three blocks over a total area of about 4600 km2. Approximately 92% remains contiguous because of four corridors; however, under 4000 km2 of this area may be effectively used by elephants. Nine landscape elements were identified, including five natural vegetation types, of which tropical moist deciduous forest is dominant. Population density assessed through the dung count method using line transects covering 275 km of walk across the effective elephant habitat of the landscape yielded a mean density of 1.1 (95% CI = 0.99–1.2) elephant/km2. Population structure from direct sighting of elephants showed that adult male elephants constitute just 2.9% and adult females 42.3% of the population with the rest being sub-adults (27.4%), juveniles (16%) and calves (11.4%). Sex ratios show an increasing skew toward females from juvenile (1:1.8) to sub-adult (1:2.4) and adult (1:14.7) indicating higher mortality of sub-adult and adult males that is most likely due to historical poaching for ivory. A rapid questionnaire survey and secondary data on elephant–human conflict from forest department records reveals that villages in and around the forest divisions on the eastern side of landscape experience higher levels of elephant–human conflict than those on the western side; this seems to relate to a greater degree of habitat fragmentation and percentage farmers cultivating annual crops in the east. We provide several recommendations that could help maintain population viability and reduce elephant–human conflict of the Anamalai elephant landscape. 相似文献
86.
87.
Wahid Abu-Amer Charles M. Lawrie Jeffrey J. Nepple John C. Clohisy Susan Thapa 《The Iowa orthopaedic journal》2022,42(2):90
BackgroundMental health is becoming increasingly important in patient outcomes. The patient reported outcome measurement information system (PROMIS) was developed by the NIH to collect outcome data in rapid dynamic fashion on electronic platforms. The potential role of PROMIS in monitoring young total hip arthroplasty (THA) patients is under-investigated. The purpose of this study is to investigate correlations between PROMIS Depression or Anxiety with SF-12 mental component score.MethodsWe identified 223 hips (200 patients) who underwent primary THA over a 30-month period at a single institution. Patients without preoperative PROMIS or SF-12 mental scores, or >50yo were excluded. All data was collected preoperatively and included age, sex, BMI, ASA, PROMIS Depression, PROMIS Anxiety, and SF-12 Mental component score. We considered floor and ceiling effects as significant if >15% of patients responded with the lowest or highest possible score, respectively. Relationships between SF-12 and PROMIS were investigated using correlation (R), and were considered strong if R>0.7.ResultsMean age was 41-years-old, mean ASA category was 2, mean BMI was 30kg/m2, and 54% were female. None of the PROMs showed any floor/ceiling effects at baseline. PROMIS Depression showed a strong correlation to SF-12 Mental (R=-0.72) while PROMIS Anxiety showed a moderate correlation to SF-12 Mental (R=-0.58). Negative linear relationships were observed because a lower PROMIS Depression/Anxiety values indicates less depressive/anxious feelings (inverse of SF-12).ConclusionPROMIS Anxiety and Depression correlate well with SF-12 mental. These PROMIS domains may be attractive alternatives to legacy mental health instruments in young THA patients. Level of Evidence: III 相似文献
88.
Dahal GR Karki P Thapa A Shahnawaz M Shin SY Lee JS Cho B Park IS 《Archives of biochemistry and biophysics》2007,468(1):134-139
To investigate the signal transduction pathway of caspase-2, cell permeable Tat-reverse-caspase-2 was constructed, characterized and utilized for biochemical and cellular studies. It could induce the cell death as early as 2 h, and caspase-2-specific VDVADase activity but not other caspase activities including DEVDase and IETDase. Interestingly, nuclear DNA fragmentation occurred and consistently DNA fragmentation factor (DFF45)/Inhibitor of caspase-activated DNase (ICAD) was cleaved inside the cell as well as in vitro, suggesting a role of caspase-2 in nuclear DNA fragmentation. 相似文献
89.
90.
Adheesh Bhandari Chen Zheng Namita Sindan Namrata Sindan Ruida Quan Erjie Xia Yubaraj Thapa Dependra Tamang Ouchen Wang Xiaohe Ye Duping Huang 《Journal of cellular and molecular medicine》2019,23(8):5235-5245
Breast cancer (BC) is a common malignant tumour for the adult female and its relative incidence has increased continuously in recent years. The primary molecular mechanisms of breast tumourigenesis remain unclear. With the sequencing technology, we found that coatomer protein complex subunit beta 2 (COPB2) gene is overexpressed in breast cancer tissues. However, the biological function of COPB2 in BC has yet to be determined. This current research demonstrates, significant up‐regulation of COPB2 in tissues of breast cancer while comparing the adjacent normal tissue both invalidated cohort and TCGA cohort. Up‐regulated expression of COPB2 was correlated with lymph node metastasis (LNM) and oestrogen receptor (ER) in the TCGA cohort and a high level of COPB2 was associated with age and lymph node metastasis in the validated cohort. Besides, logistic analysis illustrated in BC patient COPB2 expression, tumour size, age, ER and disease stage were independent high‐risk factors of LNM. Loss of function experiments revealed that down‐regulation of COPB2 could inhibit capacities of proliferation and cell invasion in MDA‐MB‐231 and BT‐549 cell lines. Moreover, underexpression of COPB2 could decrease the EMT‐related protein N‐cadherin and vimentin which may lead to cell invasion. This current research provides new shreds of evidence that COPB2 overexpression shows significant character in the progression of breast cancer. To best of our knowledge, our findings indicated that COPB2 was vital oncogene which was associated with breast cancer. 相似文献