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   2068篇
  免费   113篇
  国内免费   7篇
耳鼻咽喉   52篇
儿科学   115篇
妇产科学   104篇
基础医学   166篇
口腔科学   90篇
临床医学   195篇
内科学   512篇
皮肤病学   63篇
神经病学   99篇
特种医学   45篇
外科学   372篇
综合类   27篇
预防医学   67篇
眼科学   29篇
药学   155篇
中国医学   6篇
肿瘤学   91篇
  2023年   12篇
  2022年   24篇
  2021年   38篇
  2020年   37篇
  2019年   39篇
  2018年   52篇
  2017年   34篇
  2016年   83篇
  2015年   76篇
  2014年   92篇
  2013年   134篇
  2012年   168篇
  2011年   181篇
  2010年   89篇
  2009年   95篇
  2008年   150篇
  2007年   161篇
  2006年   150篇
  2005年   153篇
  2004年   100篇
  2003年   74篇
  2002年   86篇
  2001年   18篇
  2000年   21篇
  1999年   12篇
  1998年   5篇
  1997年   7篇
  1996年   4篇
  1995年   6篇
  1992年   7篇
  1991年   6篇
  1990年   7篇
  1989年   5篇
  1988年   8篇
  1987年   6篇
  1986年   5篇
  1985年   7篇
  1984年   3篇
  1982年   3篇
  1979年   2篇
  1978年   4篇
  1977年   2篇
  1975年   2篇
  1974年   3篇
  1973年   4篇
  1972年   2篇
  1971年   1篇
  1970年   2篇
  1966年   1篇
  1963年   1篇
排序方式: 共有2188条查询结果,搜索用时 0 毫秒
101.
Possible effect of three common mutations in (MTHFR 677 C-T; 1317 T-C; 1298 C-A) and FV 1691 G-A mutation was studied in Turkish patients with thrombosis and compared with normal controls. The case-control study included 68 patients with the diagnosis of deep vein thrombosis and 66 controls, consecutively selected among subjects without personal and familial history of atherothrombosis. Patients with deep vein thrombosis were selected if Doppler ultrasonography was positive. Only, the comparison of factor V 1691 G-A mutation revealed statistically significant difference in control (6.06%) and deep vein thrombosis (23.5%) group. Risk assessment of double prothrombotic gene alterations revealed only FV 1691 G-A mutation as an independent risk factor for thrombosis (odds ratio 4.7 [1.5-15.0]), but our data suggested that MTHFR 677 has effect on its own (odds ratio 1.97 [0.6-2.7]) but may have synergy with FV 1691 G-A (odds ratio 8.12 [2.0-25.3]). However, MTHFR 1298 A-C and 1317 T-C does not have any effect; furthermore, being heterozygote at two different loci or homozygosity at least in a locus for 677 and 1298 revealed a significant increase (odds ratio 9 and 24 [1.3-59.3 and 2.3-240.3]) between these two groups.  相似文献   
102.
103.
The case of a 40 year old female patient of SLE who developed fatal neuroleptic malignant syndrome following administration of serenase (haloperidol) is reported. Relevant literature has been reviewed.  相似文献   
104.
OBJECTIVE: Meconium-stained amniotic fluid (MSAF) is thought to be a sign of fetal hypoxia, which causes activation of coagulation and inhibition of fibrinolysis. Inflammation is also seen in MSAF. On the other hand, thrombin activatable fibrinolysis inhibitor (TAFI) is an inhibitor of fibrinolysis and a regulator of vascular inflammation. For this reason, in this study we aimed to evaluate the relation between hypoxia, fibrinolysis, and inflammation by determining the levels of TAFI activity (TAFIa) in MSAF where inflammation was also thought to have a role in the pathogenesis. METHODS: The MSAF group consisted of 22 neonates; 20 neonates served as the control group. Plasma TAFIa levels were evaluated in all neonates in the first six hours of life. RESULTS: TAFIa levels were significantly higher in the MSAF group when compared with the control group and the levels correlated negatively with cord blood pH levels. CONCLUSIONS: Increased TAFIa levels in neonates with MSAF might be due to hypoxia. Inflammation observed in MSAF may also play an additional role in increased TAFIa expression. Although no clinical complication that can be attributed to this increase was seen, one should be alert to the complications of depressed fibrinolysis that might be observed in these neonates.  相似文献   
105.
Abstract:  HSCT associated morbidity and mortality is usually attributed to high-dose chemotherapy/radiotherapy regimens used for conditioning. Glutamine (Gln), a conditionally essential amino acid during severe catabolic states, has been shown to have favorable effects in patients with malignancies and in those undergoing HSCT. However, controversy exists regarding its routine use. Studies in children investigating gln supplementation are very limited. In the present study, including 21 gln-supplemented and 20 control pediatric patients, gln supplementation was shown to reduce the duration of fever and decrease the incidence of SOS during the HSCT course. In addition, a decrease in drug-related toxicity and a trend toward reduced incidence of severe mucositis were observed.  相似文献   
106.
The extract of the leaves of Guiera senegalensis was found to detoxify (in vitro) venom from two common northern Nigerian snake species, Echis carinatus and Naja nigricollis, in separate experiments. There was a remarkable reduction in the mortality of albino mice after intra-peritoneal (i.p.) administration of reconstituted venom incubated with the extract, when compared to those challenged with the venom only. The survival of the animals exposed to the venom incubated with the different concentrations of the extract was used as the in vitro detoxification parameter.  相似文献   
107.
BACKGROUND: To investigate the diagnostic efficacy of preoperative lymphoscintigraphy (LS), Ga-67 scintigraphy (GS) and computed tomography (CT) for detection of lymph node metastasis in patients with endometrial or ovarian carcinoma. METHODS: The results of preoperative LS, GS and CT used to detect lymph node metastasis were compared to the postoperative histopathological results of lymph node dissection materials of a total of 37 patients, including 16 patients with endometrial and 21 patients with ovarian carcinomas. The diagnostic efficacy of these methods for detecting lymph node metastasis were calculated. RESULTS: When the results of all of the patients were taken into account, the preoperative LS, GS and CT were found to have sensitivities of 50%, 20% and 40% and specificities of 51.8%, 96.3%, and 92.6%, respectively, for detection of pelvic lymph node metastasis. The same methods had sensitivities of 27.3%, 27.3% and 72.7% and specificities of 88.5%, 88.5%, 84.6%, respectively, for detecting para-aortic lymph node metastasis in all patients. CONCLUSION: These data suggested that although LS, GS and CT had relatively high specificity, low sensitivity of these imaging methods precluded their routine preoperative use for diagnosis of lymph node metastasis of ovarian or endometrial carcinoma.  相似文献   
108.

Research question

Are high-responder IVF patients protected from the deleterious effect of prematurely elevated serum progesterone level on the probability of pregnancy?

Design

In this retrospective cohort study, 2971 autologous fresh embryo transfer IVF cycles with gonadotrophin-releasing hormone agonist long protocol were analysed to investigate whether the detrimental effect of prematurely rising progesterone levels on clinical pregnancy rate (CPR) varies depending on the magnitude of ovarian response. Nine different evenly spaced intervals were constructed for serum progesterone level on the human chorionic gonadotrophin day (<0.5/0.5–0.9/1–1.4/1.5–1.9/2–2.4/2.5–2.9/3–3.4/3.5–3.9/>4 ng/ml). Then, IVF cycles in each of these intervals were further divided into low (≤3 oocytes), normal (4–15 oocytes) and high responders (≥16 oocytes).

Results

The progressive rise of serum progesterone from the <0.5 to the >4 ng/ml interval caused a gradual and continuous decline in the CPR of all three types of ovarian response. The absolute difference in the CPR between the lowest and the highest progesterone groups was not related to the magnitude of ovarian response (–26.6%, –37.7% and –40.7% for the low, normal and high responders, respectively). On multivariate logistic regression analysis, the detrimental effect of progesterone started at 1.5–1.9 ng/ml, 3.0–3.4 ng/ml and 4.0–4.4 ng/ml intervals for the low, normal and high responders, respectively.

Conclusion

High responders are not exempt from the detrimental effects of prematurely rising serum progesterone levels but the threshold interval where the detrimental effect begins is higher in the high responders compared with the low and normal responders.  相似文献   
109.
110.
Schaar et al. [1] investigated the role of interferon-alpha(IFN) as maintenance therapy in patients with multiple  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