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   2172篇
  免费   165篇
  国内免费   17篇
耳鼻咽喉   28篇
儿科学   68篇
妇产科学   116篇
基础医学   285篇
口腔科学   57篇
临床医学   174篇
内科学   678篇
皮肤病学   32篇
神经病学   202篇
特种医学   37篇
外科学   270篇
综合类   12篇
一般理论   1篇
预防医学   107篇
眼科学   17篇
药学   99篇
中国医学   4篇
肿瘤学   167篇
  2023年   22篇
  2022年   38篇
  2021年   77篇
  2020年   26篇
  2019年   51篇
  2018年   63篇
  2017年   54篇
  2016年   65篇
  2015年   68篇
  2014年   82篇
  2013年   87篇
  2012年   147篇
  2011年   145篇
  2010年   95篇
  2009年   94篇
  2008年   157篇
  2007年   159篇
  2006年   146篇
  2005年   132篇
  2004年   118篇
  2003年   128篇
  2002年   104篇
  2001年   21篇
  2000年   33篇
  1999年   29篇
  1998年   12篇
  1997年   13篇
  1996年   20篇
  1995年   16篇
  1994年   6篇
  1993年   12篇
  1992年   20篇
  1991年   18篇
  1990年   16篇
  1989年   12篇
  1988年   12篇
  1987年   3篇
  1986年   5篇
  1985年   6篇
  1984年   6篇
  1983年   3篇
  1982年   4篇
  1980年   6篇
  1979年   4篇
  1977年   3篇
  1976年   2篇
  1975年   2篇
  1973年   2篇
  1970年   2篇
  1969年   2篇
排序方式: 共有2354条查询结果,搜索用时 15 毫秒
101.
102.
Shimon I  Ram Z  Cohen ZR  Hadani M 《Neurosurgery》2002,51(1):57-61; discussion 61-2
OBJECTIVE: Transsphenoidal surgery is the preferred treatment modality for adrenocorticotropic hormone-secreting pituitary adenomas. In the past 2 decades, several institutions in the United States and Europe have reported remission rates of 70 to 85% after transsphenoidal surgery for treatment of Cushing's disease. We analyzed our postoperative results for a large cohort of patients with Cushing's disease. METHODS: Eighty-two patients with adrenocorticotropic hormone-secreting adenomas (79 microadenomas and 3 macroadenomas) underwent transsphenoidal surgery between 1990 and 2000. Seventy-seven patients were surgically treated for the first time, and 13 patients underwent reoperations (5 had undergone the first operation elsewhere) because of previous surgical failure (10 patients) or recurrence (3 patients). The mean postoperative follow-up period was 4.2 +/- 2.8 years. Biochemical remission was defined as postoperative normalization of elevated 24-hour urinary free cortisol secretion and suppression of morning cortisol levels with 1 mg of dexamethasone. RESULTS: Remission was achieved for 78% of all patients after one operation and for 62% of patients who underwent a second operation. The recurrence rate was 5%. Ten patients did not exhibit a visible tumor on magnetic resonance imaging scans, and the other patients were divided according to adenoma size (2-5 or 6-10 mm). Remission rates were similar for the three groups of patients (78-80%). Pituitary tumor stained for adrenocorticotropic hormone was detected in 78% of resected pituitary tissue specimens obtained from patients who achieved remission, compared with 53% from patients who experienced surgical failure (P = 0.06). CONCLUSION: Our series demonstrates the efficacy of transsphenoidal surgery for Cushing's disease resulting from pituitary microadenomas. Microadenoma size had no effect on the remission rate. Reoperations are indicated after initial surgical failures.  相似文献   
103.
Postoperative chylous ascites is a rare complication of retroperitoneal surgery. The treatment of postoperative chylous ascites is primarily conservative, consisting of repeated paraceteses, medium chain triglyceride (MCT) diet, salt restriction, diuretics and bowel rest with total parenteral nutrition. Occasionally, chylous ascites may take a protracted course which may necessitate insertion of peritoneo-venous shunts or direct surgical lymphostasis. Recently, Somatostatin was shown to be highly effective in closure of refractory lymphatic fistulas. We present a case of refractory chylous ascites following radical nephrectomy with inferior vena caval thrombectomy that failed to respond to conventional conservative measures and resolved rapidly following the administration of Somatostatin.  相似文献   
104.
Olanzapine is a substrate of the cytochrome P450 enzyme (CYP) 1A2. In this study, pharmacokinetic interactions and clinical effects of adding the CYP1A2 inhibitor fluvoxamine to steady-state olanzapine was examined in patients suffering from schizophrenia. Eight patients had been treated for at least 3 months with 10 to 20 mg/day olanzapine. Fluvoxamine (100 mg/day) was added (week 0) to the olanzapine treatment and continued for 8 weeks. Concentrations of olanzapine and its metabolite N-desmethylolanzapine and of fluvoxamine were analyzed at weeks 0, 1, 4, and 8. Addition of fluvoxamine resulted in a 12% to 112% ( < 0.01) increase of olanzapine from 31 +/- SD 15 ng/mL (week 0) to 56 +/- 31 ng/mL (week 8) in all patients. N-desmethylolanzapine concentrations were not significantly changed ( > 0.05). Fluvoxamine concentrations were 48 +/- 26 ng/mL on week 1 and 83 +/- 47 ng/mL on week 8. It is concluded that fluvoxamine affects olanzapine degradation and thus increases olanzapine concentrations. Although the combination was well tolerated in this sample and the negative symptom response appeared to be favorable in at least five patients, the combination therapy of olanzapine and fluvoxamine should be used cautiously and should be controlled by therapeutic drug monitoring to avoid olanzapine-induced side effects or intoxications.  相似文献   
105.
BACKGROUND: Personal space is the area individuals maintain around themselves into which others cannot intrude without arousing discomfort. OBJECTIVE: We tested the hypotheses that psychological distancing of patients with schizophrenia would be a characteristic of 1) diagnosis and/or 2) syndrome. METHODS: For this aim, 30 schizophrenic and 30 age matching normal males established comfortable interpersonal distances for 20 word-stimuli representing family members, significant others, self-images, emotionally neutral and threatening surroundings. The distances were assessed by a paper-and-pencil projective measure, the Comfortable Interpersonal Distance scale and the patients' psychopathological symptoms were quantified by the Positive and Negative Syndrome Scale. t-tests and correlational analyses were employed to examine the relationships between the parameters of interest. RESULTS: The rank order (hierarchy) of preferable interpersonal distances of patients with schizophrenia was similar to that of normal subjects. At the same time, psychological distance from family members and themselves was substantially larger among the patients. There were no significant correlations between any kind of interpersonal distance and positive syndrome of schizophrenia, while negative syndrome showed significant inverse association with distances from emotionally neutral and threatening figures and positive correlation with family member and self-image distances. CONCLUSION: The results suggest that the negative syndrome of schizophrenia attenuates the differences between interpersonal distances from generally close and distant persons.  相似文献   
106.
OBJECTIVES: In this retrospective study, we defined the clinicopathologic characteristics of oral Kaposi's sarcoma (KS) and determined the presence of human herpesvirus 8 in the oral lesions in a group of South African patients. These results were compared with similar data from patients in developed countries. STUDY DESIGN: Eighty-one cases of oral KS were retrieved from the departmental archives. Fourteen patients with oral pyogenic granuloma served as control subjects. DNA was extracted by using a modified phenol chloroform extraction method and amplified by using polymerase chain reaction. If beta-globin DNA sequences could not be demonstrated, the patient was excluded from the study. RESULTS: Of the 81 patients included in the study, 68 (84%) had been diagnosed since 1997. Oral KS was often the first presenting sign of human immunodeficiency virus infection. Some of the lesions exceeded 4 cm in diameter. The most commonly affected site was the palate (37 patients), followed by the tongue and gingiva. Multiple oral sites were frequently involved. The mean age of the patients was 34.7 years (range, 2-58 years). The male-to-female ratio was 1.31 to 1. Most of the patients (94%) were black. Human herpesvirus 8 DNA sequences were detected in 44 of the 45 cases of oral KS in which the DNA was analyzed, and in 1 case of pyogenic granuloma. CONCLUSIONS: The only significant clinicopathologic differences in findings between our study and previous studies in developed countries were (1) the male-to-female ratio, (2) the preponderance of black patients, and (3) the more frequent involvement of the tongue. There are no studies reporting the clinicopathologic characteristics of oral KS in populations of developing countries.  相似文献   
107.
A novel cell growth regulator, named Falkor, was identified using a functional approach to mammalian gene cloning, the Genetic Supressor Elements (GSE) method. In this screen, expression of the C-terminal domain of Falkor conferred cells with resistance to cisplatin-induced growth arrest. Expression of the C-terminus of Falkor, but not of the full-length protein, enhanced cell growth both following genotoxic stress and under normal conditions suggesting a general role for this protein in cell growth control. This effect of the C-terminus fragment was abrogated by over-expression of the full-length Falkor, suggesting that the fragment counteracts the function of the full-length protein. Falkor is encoded by a 2-kb mRNA which is present at different levels in various tissues, and is localized in the nucleus of cells. The C-terminal domain of Falkor, isolated from the GSE library, has significant homology to a known human and rat cell growth regulator, SM-20, and to the C. elegans protein EGL-9, recently shown to modify the Hypoxia Inducible Factor-1alpha. The homology suggests that these proteins share a functional domain that is conserved among a family of growth regulation proteins.  相似文献   
108.
Cohen I  Azaria R  Shapira J  Yigael D  Tepper R 《Cancer》2002,94(12):3101-3106
BACKGROUND: Ultrasonography has a limited value in endometrial assessment for identification of endometrial pathologies in postmenopausal tamoxifen-treated patients. METHODS: We compared the rate of endometrial pathologies and the mean +/- SD of endometrial thickness diagnosed after the first and second transvaginal ultrasonographic studies performed on 55 postmenopausal tamoxifen-treated patients with secondary endometrial thickening (Group I). This rate was also compared with 46 similar patients without secondary thickening (Group II). We also compared the mean +/- SD of endometrial thickness detected in various ultrasonographic studies, as well as various clinical features. RESULTS: A significantly higher rate of endometrial pathologies, including two cases of endometrial cancer identified in gynecologically asymptomatic patients (3.6%), was diagnosed in Group I after the second study compared with the first study (52.7% and 9.1%, respectively; P = 0.001) and compared with those diagnosed after the second study in Group II (30.4%; P = 0.03). There was a significant increase (74.7 +/- 115%) in endometrial thickness after the second study compared with the first study performed on Group I (10.7 +/- 5.53 mm and 16.59 +/- 5.53 mm, respectively; P = 0.0001) and a significant difference in endometrial thickness demonstrated in the second study performed on Groups I and II (16.59 +/- 5.53 mm and 11.4 +/- 3.91 mm, respectively; P = 0.001).There were no significant differences in the time elapsed since the diagnosis of breast carcinoma and from the beginning of tamoxifen treatment to the performance of the first ultrasonographic study as well as the time elapsed between the first and second studies performed. CONCLUSIONS: A significant increase (> 50%) in secondary endometrial thickening, measured ultrasonographically, in postmenopausal tamoxifen-treated patients, is associated with a high rate of endometrial pathologies, including endometrial cancer.  相似文献   
109.
Kutz I 《Archives of general psychiatry》2002,59(6):565; author reply 565-565; author reply 566
  相似文献   
110.
We describe an 18-month-old boy who suffered venous air embolism during an arthrogram. Dangers associated with air injection are emphasized, illustrating the importance of careful monitoring to detect adverse events. We recommend caution when employing this method of hip joint evaluation.  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