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   166篇
  免费   13篇
儿科学   5篇
妇产科学   9篇
基础医学   21篇
口腔科学   1篇
临床医学   17篇
内科学   32篇
皮肤病学   2篇
神经病学   14篇
特种医学   10篇
外科学   20篇
综合类   2篇
预防医学   6篇
眼科学   1篇
药学   18篇
  1篇
肿瘤学   20篇
  2023年   4篇
  2022年   11篇
  2021年   2篇
  2020年   7篇
  2019年   9篇
  2018年   16篇
  2017年   8篇
  2016年   8篇
  2015年   11篇
  2014年   10篇
  2013年   9篇
  2012年   13篇
  2011年   16篇
  2010年   7篇
  2009年   4篇
  2008年   9篇
  2007年   9篇
  2006年   4篇
  2005年   6篇
  2004年   4篇
  2003年   2篇
  2002年   3篇
  2001年   1篇
  2000年   1篇
  1999年   2篇
  1996年   1篇
  1988年   1篇
  1985年   1篇
排序方式: 共有179条查询结果,搜索用时 0 毫秒
51.
Octreotide, a synthetic analog of natural hormone somatostatin, was labelled with 99mTc. Labelling was accomplished by reduction of the cysteine bridge, which provided sulfhydryl groups for chelating with 99mTc. Sodium ascorbate and sodium dithionite in different concentrations were used as reducing agents. Different amounts of sodium pertechnetate were used for labelling of peptide. When the mass ratio of peptide and sodium ascorbate was 1:100 and the final concentration of dithionite in the labelling vial was 0.2-0.4 microg/microl with 0.18-1.48 GBq sodium pertechnetate more than 80% radiolabelling efficiency was confirmed by RP-HPLC, ITLC-SG and C18 Cartridge analysis. The stability of the 99mTc-peptide bond was evaluated by human serum challenge and that showed the stability was 90% after 4h.  相似文献   
52.
Growth factors have a pivotal role in chondrogenic differentiation of stem cells. The differential effects of known growth factors involved in the maintenance and homeostasis of cartilage tissue have been previously studied in vitro. However, there are few reported researches about the interactional effects of growth factors on chondrogenic differentiation of stem cells. The aim of this study is to examine the combined effects of four key growth factors on chondrogenic differentiation of mesenchymal stem cells (MSCs). Isolated and expanded rabbit bone marrow-derived MSCs underwent chondrogenic differentiation in a micromass cell culture system that used a combination of the following growth factors: transforming growth factor beta 1 (TGF-β1), bone morphogenetic protein 2 (BMP2), parathyroid hormone related protein (PTHrP), and fibroblast growth factor 2 (FGF2) according to a defined program. The chondrogenic differentiation program was analyzed by histochemistry methods, quantitative RT-PCR (qRT-PCR), and measurement of matrix deposition of sulfated glycosaminoglycan (sGAG) and collagen content at days 16, 23, and 30. The results showed that the short-term combination of TGF-β1 and BMP-2 increased sGAG and collagen content, Alkaline phosphates (ALP) activity, and type X collagen (COL X) expression. Application of either PTHrP or FGF2 simultaneously decreased TGF-β1/BMP-2 induced hypertrophy and chondrogenic markers (at least for FGF2). However, successive application of PTHrP and FGF2 dramatically maintained the synergistic effects of TGF-β1/BMP-2 on the chondrogenic differentiation potential of MSCs and decreased unwanted hypertrophic markers. This new method can be used effectively in chondrogenic differentiation programs.  相似文献   
53.
Aim: Introducing data sharing practices into the genomic research arena has challenged the current mechanisms established to protect rights of individuals and triggered policy considerations. To inform such policy deliberations, soliciting public and research participants' attitudes with respect to genomic data sharing is a necessity. Method: The main electronic databases were searched in order to retrieve empirical studies, investigating the attitudes of research participants and the public towards genomic data sharing through public databases. Results: In the 15 included studies, participants' attitudes towards genomic data sharing revealed the influence of a constellation of interrelated factors, including the personal perceptions of controllability and sensitivity of data, potential risks and benefits of data sharing at individual and social level and also governance level considerations. Conclusion: This analysis indicates that future policy responses and recruitment practices should be attentive to a wide variety of concerns in order to promote both responsible and progressive research.  相似文献   
54.
55.
We have elucidated the alteration in hippocampal and cerebellum function following chronic cisplatin treatment in male and female rats. Hippocampus and cerebellum related behavioral dysfunction in cisplatin-treated [intraperitoneally, 5 mg/(kg/week) for 5 weeks from 23-day-old] rats were analyzed using explorative, motor function, learning, and memory tasks (grasping, rotarod, open field, and Morris water maze tests). Exposure to cisplatin impaired the motor coordination in male and female rats. Exposure to cisplatin was reflected by a decrease in grasping time compared to vehicle-treated controls (saline) only in male rat while there were not any differences in female rats. When the rearing frequency, total distance moved and velocity of their recorded in open fieldtest, both males and females were dramatically affected by exposure to cisplatin. Compared to the saline, male and female rats trained 5 weeks after cisplatin injection showed significant memory deficits in the Morris water maze test. However, hippocampal and cerebellum functions of male and female rats were profoundly affected by exposure to cisplatin while no sex differences in the most variable were evident.  相似文献   
56.
57.
In this study, ionic parameters (Na+, K+, Mg+2, and Ca+2) and metabolite factors (cholesterol, total protein, and glucose) of serum and their interrelationships were detected in 48 specimens of kutum (Rutilus frisii kutum) captured during spawning migration. Results indicated that values of Na+, Ca+2, K+, and Mg+2 revealed the highest to the lowest content in blood serum of kutum, respectively. Cholesterol concentration was higher than glucose and the latter was estimated more than total protein. Na+ was positively correlated with Mg+2 (P?<?0.01), whereas it shows reversed correlations with glucose (P?<?0.01) and pH (P?<?0.05). Mg+2 had a significant and positive relationship with the ratio of Na+ to K+ and Ca+2 to K+ ratio (P?<?0.05) while it represented a reverse correlation with pH (P?<?0.01) and glucose (P?<?0.05). The correlation between the ratio of Na+ to K+ and Ca+2 to K+ ratio was positive (P?<?0.01) and Ca+2 concentration correlated positively with total protein (P?<?0.05). Concerning to the relationships between ionic and metabolite factors on reproductive cycle, acid–alkaline balance, and growth and osmoregulation in kutum, the results deduced in the present trail might improve reproductive and cultivation management of this valuable species.  相似文献   
58.
59.
Retrospective studies suggest that there is high mortality in children with sickle cell anemia (SCA) and severe malaria. We assessed mortality in Ugandan children with severe malarial anemia (SMA, n = 232) or cerebral malaria (CM, n = 267) by sickle cell hemoglobin genotype. Admission and 2‐year follow‐up mortality did not differ among children with SMA who had homozygous form of sickle cell hemoglobin (HbSS) versus normal form of adult hemoglobin (admission, 0/22, 0%, vs. 1/208, 0.5%; follow‐up, 1/22, 4.5%; 7/207, 3.4%, respectively; all P > 0.6). The single child with CM and HbSS survived. The study findings highlight the need for large prospective studies of malaria‐related mortality in children with SCA.  相似文献   
60.

Background

Standardized Wilms tumor treatment protocols exist for low- and middle-income countries, but outcomes equivalent to high-income countries are not achieved outside of clinical trials. As Wilms tumor treatment protocols in Africa shift with increasing resource capacity, it is not known how treatment compliance to each stage of therapy affects outcomes and where the critical breakpoints are for protocol adherence in clinical practice.

Procedure

We describe both treatment outcomes and treatment protocol adherence in a retrospective single-center cohort study of pediatric Wilms tumor patients at a zonal cancer referral hospital in Tanzania from 2016 to 2019, treated per the International Society of Paediatric Oncology standard (2016–2017) or Tanzania adapted (2018–2019) therapy protocols.

Results

A total of 69 patients were evaluated. The two-year overall survival and event-free survival rates were 40% and 29%, respectively. Only 29% of patients completed recommended chemotherapy per protocol, and completion of preoperative and postoperative chemotherapy was predictive of two-year overall survival (odds ratio [OR] 14.4, p < .001). There were delays at almost every stage of treatment, especially time from preoperative chemotherapy to surgery (56 days), from surgery to pathology report (30 days), and from surgery to initiation of postoperative chemotherapy (38 days).

Conclusions

Nonadherence with recommended Wilms tumor treatment guidelines due to key health system delays correlated to reduced overall survival rates, with chemotherapy nonadherence due to abandonment, lack of surgery, and deaths on therapy as the strongest contributors. Future interventions targeting health system delays and reducing deaths during therapy are critical to improving protocol compliance and increasing overall survival for pediatric Wilms tumor patients in low-resource settings.  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