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   588篇
  免费   33篇
  国内免费   1篇
耳鼻咽喉   42篇
儿科学   8篇
妇产科学   17篇
基础医学   77篇
口腔科学   5篇
临床医学   70篇
内科学   84篇
皮肤病学   13篇
神经病学   87篇
特种医学   18篇
外科学   64篇
综合类   5篇
预防医学   61篇
药学   46篇
肿瘤学   25篇
  2019年   5篇
  2018年   9篇
  2015年   3篇
  2014年   13篇
  2013年   21篇
  2012年   14篇
  2011年   9篇
  2010年   4篇
  2009年   11篇
  2008年   21篇
  2007年   32篇
  2006年   22篇
  2005年   37篇
  2004年   29篇
  2003年   19篇
  2002年   39篇
  2001年   14篇
  2000年   27篇
  1999年   30篇
  1998年   6篇
  1997年   5篇
  1996年   12篇
  1995年   2篇
  1993年   7篇
  1992年   11篇
  1991年   21篇
  1990年   22篇
  1989年   22篇
  1988年   13篇
  1987年   21篇
  1986年   17篇
  1985年   17篇
  1984年   7篇
  1983年   3篇
  1982年   9篇
  1981年   5篇
  1980年   3篇
  1979年   7篇
  1978年   3篇
  1977年   5篇
  1976年   7篇
  1975年   2篇
  1974年   3篇
  1973年   2篇
  1972年   7篇
  1971年   7篇
  1969年   2篇
  1968年   2篇
  1967年   2篇
  1966年   4篇
排序方式: 共有622条查询结果,搜索用时 15 毫秒
11.
12.
Bowel injury is a known inherent complication of minimally invasive gynecologic surgery; however, it does not automatically signify medical malpractice. Plaintiff attorneys representing patients seeking legal recourse from a bowel injury typically allege claims of intraoperative negligence, delay in diagnosis, or lack of informed consent in an effort to circumvent the assertion that it is a known inherent complication. In addition, damage awards in bowel injury lawsuits can easily exceed the amount covered by the policy limits of a medical malpractice insurance plan, leaving the gynecologist financially responsible for the difference. Therefore, it is crucial to understand when it may be appropriate to consent to a settlement offer, which can relieve the gynecologist from financial liability for amounts awarded above the medical malpractice policy limits. The purpose of this medical-legal review is to make minimally invasive gynecologic surgeons more aware of the legal strategies used by plaintiff attorneys representing patients who have incurred bowel injuries, and how to limit liability in lawsuits.  相似文献   
13.
Lipoprotein cholesterol/triglyceride ratio changes have been observed previously with sex hormone use. To determine if the lipoprotein cholesterol/triglyceride ratio is similarly changed by pregnancy and postpartum lactation, we examined pregnant subjects at 36 weeks gestation and the same women at 6 weeks postpartum and compared them to age-matched, nonpregnant women using or not using oral contraceptives. The cholesterol/triglyceride ratios were examined as means and medians and as curvilinear functions of increasing triglyceride concentration. Median ratios did not predict all ratio changes identified graphically. At very-low-density lipoprotein (VLDL) triglyceride concentrations below 40 mg/dL, the VLDL ratio is less than control in oral contraceptive users and further reduced in pregnant women. Above triglyceride concentrations of 40-60 mg/dL, the curves in the three groups are indistinguishable. No effect of lactation is observed. The low-density lipoprotein (LDL) cholesterol/triglyceride ratio is comparably lower in pregnant subjects and oral contraceptive users at all concentrations of lipoprotein triglyceride and again there is no effect of lactation. In high-density lipoprotein (HDL), there is no effect of either pregnancy or oral contraceptive use on the cholesterol/triglyceride ratio, while it is significantly higher with lactation. Postpartum decreases in the VLDL and LDL cholesterol/triglyceride ratio are seen at all lipoprotein concentrations independent of lactation. We conclude that triglyceride enriches VLDL at low concentrations and LDL at all concentrations in pregnancy and with oral contraceptive use, suggesting a common, hormonal mechanism. HDL is enriched with cholesterol during postpartum lactation, consistent with decreased transfer of cholesterol to other lipoproteins.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
14.
425 patients with pulmonary emboli at post mortem were studied retrospectively with the main focus on the clinical diagnosis. The diagnosis of pulmonary embolus was made or suspected while the patient was still alive in 59 patients (14%) and was first written in the post mortem request form in 130 patients (30%). In 236 patients (56%) the diagnosis was made only at post mortem. Even in fatal emboli the diagnosis was missed in 43% of cases. A multiplicity of non specific symptoms and signs was observed with a minority of patients showing signs and symptoms considered as typical. Of 231 thrombophlebitis processes found in locations which could give rise to clinical symptoms in the lower extremities the diagnosis was noted only in 25 cases. Chest x-ray and ECG were negative in two thirds of the cases. The high rate of misdiagnosis derived from two reasons: (a) subjective factors: lack of awareness; (b) objective difficulties: lack of specificity of clinical symptoms and signs as well as of results of the routine tests (chest x-ray and ECG). Since sophisticated confirmative tests for pulmonary emboli will be performed only on the basis of clinical suspicion, clinical awareness based on the observations detailed in this survey is still the cornerstone of diagnosis.  相似文献   
15.
Logical grammatical structures comprehension is the ability to understand the relations between objects, actions, and qualities in spoken and written sentences. The Logical Grammatical Structures Test (LGST) was especially devised to assess these abilities in children and adolescents. In the present study the LGST was administered to 405 healthy Dutch children and adolescents. The aims of the present study were (i) to evaluate the psychometric properties of the LGST (using an Item Response Theory framework), and (ii) to establish demographically corrected normative data. The results showed that there was a strong curvilinear relationship between age and LGST performance, i.e., the relative improvement in ability level was much more pronounced for younger children (aged below 14 years) than for older children (aged above 14 years). Level of parental education was positively associated with the LGST performance. Normative data that took the relevant demographic variables into account were established, and it was shown that the LGST had sound psychometric properties.  相似文献   
16.
Erythrophagocytosis by neutrophils is a rare phenomenon in myeloid malignancies, and its clinicopathologic significance is not fully understood. We report a unique case of erythrophagocytosis by dysplastic neutrophils in chronic myelomonocytic leukemia (CMML) and subsequent transformation to acute myeloid leukemia (AML). Review of multiple marrow samples, both pretreatment and post-treatment, demonstrated a correlation between percentage of dysplastic neutrophils and degree of erythrophagocytosis. Erythrophagocytosis was observed only in dysplastic forms of neutrophils. Post-transplant marrows with engraftment of donor cells showed no neutrophilic dysplasia or erythrophagocytosis. Possible mechanisms of neutrophilic erythrophagocytosis in myeloid malignancies are discussed.  相似文献   
17.
Recent studies have supported the possibility that mechanisms other than alterations in transcapillary oncotic pressure may contribute to edema formation in nephrotic syndrome. In a patient with a discrete, partial obstruction to lymphatic flow in the left upper extremity, the authors determined the transcapillary oncotic pressure differential in the obstructed, more edematous extremity and the contralateral, unobstructed extremity. The results demonstrate a normal transcapillary oncotic pressure gradient in the unobstructed extremity, while in contrast, the gradient in the obstructed extremity was reduced. Clinically, the edema resolved completely in conjunction with resolution of the nephrotic syndrome. The authors conclude, therefore, that the obstructed extremity may be more susceptible to edema formation because of inability to increase lymphatic flow during periods of hypoalbuminemia to levels sufficient to reduce the interstitial oncotic pressure gradient. Furthermore, the normal gradient in the unobstructed extremity supports the view that other mechanisms, such as intrinsic alterations in renal sodium reabsorption, may be involved in edema formation because edema was present without demonstrable alterations in the transcapillary oncotic pressure differential and plasma volume was increased in this patient.  相似文献   
18.
Attempted to predict therapeutic persistence, as measured by the total number of sessions attended, with the MMPI. High persisters were defined as patients who attended six or more sessions, while low persisters were patients who attended fewer than six sessions. Ss were 360 (180 high persisting, 180 low persisting) female outpatients and 204 (102 high persisting, 102 low persisting) male outpatients. All groups were divided into equal halves in order to allow for cross-validation of three separate discriminant functions: One for males, one for females, and one for the entire sample (male + female). Cross-validation revealed that only the discriminant function for males achieved a classification accuracy (60%) greater than chance expectations. A series of biserial correlations indicated that male persisters tended to be less defensive while experiencing greater distress and that female persisters tended to be more introverted and less impulsive relative to their respective low-persisting counterparts.  相似文献   
19.
BACKGROUND: The PI3K/AKT/mTOR pathway is central to prostate cancer progression. A preliminary investigation of immuno-histochemical expression of mammalian target of rapamycin (mTOR) pathway markers was undertaken to identify patterns of expression in prostate tissue. METHODS: Immunohistochemistry was performed on a custom-made prostate tissue array. Mean long scores and variability of long scores for each marker were recorded for normal lumenal cells, prostate intraepithelial neoplasia (PIN), and cancer. RESULTS: Expression of PTEN decreased and mTOR signaling pathway markers increased in PIN and in cancer as compared to normal cells in the majority of samples. Overexpression of 4E-BP1 and p-4E-BP1 was observed in PIN and cancer. However, in cancer, the overexpression of 4E-BP1 was significantly higher than with any other marker. DISCUSSION: Results suggest that 4E-BP1 overexpression is strongly associated with prostate cancer, especially when combined with PTEN and mTOR expression data. Hierarchical clustering analysis utilizing PTEN, mTOR, and 4E-BP1 separated normal from cancer cell populations in most cases.  相似文献   
20.
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