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   1098篇
  免费   106篇
  国内免费   2篇
耳鼻咽喉   24篇
儿科学   44篇
妇产科学   43篇
基础医学   160篇
口腔科学   45篇
临床医学   133篇
内科学   202篇
皮肤病学   11篇
神经病学   52篇
特种医学   18篇
外科学   114篇
综合类   33篇
一般理论   1篇
预防医学   171篇
眼科学   5篇
药学   54篇
中国医学   1篇
肿瘤学   95篇
  2019年   11篇
  2018年   11篇
  2017年   13篇
  2016年   10篇
  2015年   10篇
  2014年   20篇
  2013年   29篇
  2012年   51篇
  2011年   53篇
  2010年   31篇
  2009年   28篇
  2008年   37篇
  2007年   42篇
  2006年   44篇
  2005年   32篇
  2004年   35篇
  2003年   40篇
  2002年   30篇
  2001年   33篇
  2000年   45篇
  1999年   27篇
  1998年   12篇
  1997年   13篇
  1996年   11篇
  1995年   10篇
  1993年   19篇
  1992年   33篇
  1991年   23篇
  1990年   24篇
  1989年   32篇
  1988年   16篇
  1987年   22篇
  1986年   27篇
  1985年   25篇
  1984年   16篇
  1983年   25篇
  1982年   13篇
  1981年   21篇
  1980年   11篇
  1979年   17篇
  1978年   11篇
  1977年   11篇
  1975年   11篇
  1973年   11篇
  1972年   14篇
  1970年   12篇
  1969年   12篇
  1968年   14篇
  1966年   15篇
  1920年   12篇
排序方式: 共有1206条查询结果,搜索用时 0 毫秒
61.
OBJECTIVE: To evaluate the effect of once-daily, extended-release tolterodine on urinary urgency in patients with overactive bladder. METHODS: Patients with urinary frequency (eight or more micturitions per 24 hours) and urge incontinence (five or more episodes per week) were randomized to oral treatment with tolterodine extended release 4 mg once daily (n=398) or placebo (n=374) for 12 weeks. Efficacy was assessed by use of patient perception evaluations. RESULTS: The results presented are a secondary analysis of this double-blind, placebo-controlled study. Of patients treated with tolterodine extended release, 44% reported improved urgency symptoms (compared with 32% for placebo), and 62% reported improved bladder symptoms (placebo, 48%) (both P<.001 compared with placebo). The odds of reducing urgency and improving bladder symptoms were 1.68 and 1.78 times greater, respectively, for patients in the tolterodine extended release group than for patients receiving placebo. In response to urgency, there was a more than six-fold increase in the proportion of patients able to finish a task before voiding in the tolterodine extended release group. The proportion of patients unable to hold urine upon experiencing urgency was also decreased by 58% with tolterodine, compared with 32% with placebo (P<.001). The proportion of patients reporting "much benefit" from treatment was greater for tolterodine extended release than for placebo (43% versus 24%; P<.001). The only adverse events with an incidence of greater than 5% were dry mouth, headache, and constipation, with only dry mouth markedly more frequent with tolterodine than with placebo. CONCLUSION: Tolterodine extended release has demonstrable efficacy in reducing the severity of urinary urgency and is associated with improvements in overactive bladder symptoms that are meaningful to patients.  相似文献   
62.
In October 1992, Haemophilus influenzae type b (Hib) conjugate vaccine was introduced to infants in the United Kingdom with a "catch-up" program for those aged <4 years. Initially, the rate of invasive Hib disease decreased dramatically but has been increasing since 1999. To determine possible reasons for this increase, the effectiveness of Hib conjugate vaccine was estimated by use of the screening method. Between October 1993 and December 2001, a total of 443 cases of Hib infection occurred in children eligible for vaccination; 363 (82%) were fully vaccinated. Vaccine effectiveness was estimated to be 56.7% (95% confidence interval, 42.5-67.4). Effectiveness was lower in children vaccinated during infancy, compared with those who were vaccinated during the catch-up campaign (P=.0033), declined with time since vaccination (P=.0008), and was lower in children born during 2000-2002, compared with other children scheduled for infant vaccination (P=.0041). Use of a catch-up vaccination program enhanced the control of Hib infection in England and Wales. Since 1999, however, low effectiveness in infants, declining effectiveness with age, and the use of lower-efficacy vaccines have contributed to increased rates of Hib infection. The potential role of boosters needs to be considered.  相似文献   
63.
64.
PURPOSE: Pediatric patients with solid tumors treated with prolonged dose-intensive chemoradiotherapy are poor mobilizers of peripheral blood stem cells (PBSC). We have conducted a pilot study to mobilize PBSC in eight pediatric patients with relapsed solid tumors using ifosfamide, carboplatin, and etoposide (ICE) followed-up by IL-11 plus granulocyte colony-stimulating factor (G-CSF). PATIENTS AND METHODS: Patients received ifosfamide 1.8 g/m2 per day for 5 days, carboplatin 400 mg/m2 per day for 2 days, and etoposide 100 mg/m2 per day for 5 days. After completion of ICE chemotherapy, patients received daily subcutaneous injections of G-CSF (5 microg/kg per day) and IL-11 (50-100 microg/kg per day) until peripheral stem cell apheresis. RESULTS: The median age was 11 years. Diagnosis included three relapsed Hodgkin disease, three relapsed central nervous system tumors, one relapsed Wilms tumor, and one relapsed rhabdomyosarcoma. The median number of apheresis procedures required to obtain 5 x 10(6) CD34+ cells/kg was one. The mean +/- standard error of mean (SEM) total CD34+ cells collected was 14.0+/-2.7 x 10(6)/kg. The mean +/- SEM total CD34+/CD41+ cells collected was 4.6+/-1.9 x 10(6)/kg. Seven of the eight patients have subsequently undergone myeloablative chemotherapy with autologous PBSC transplantation and have reconstituted hematopoiesis with a median time to neutrophil recovery of 10 days and platelet recovery of 15.5 days. CONCLUSIONS: We conclude that the regimen of ICE/IL-11 plus G-CSF is successful in mobilizing large numbers of CD34+ PBSC cells with a limited number (one) of apheresis collections in patients that have previously been heavily pretreated with chemotherapy/radiotherapy.  相似文献   
65.
This study retrospectively compared 34 women who had a sacrospinous hysteropexy and 36 who had a vaginal hysterectomy and sacrospinous fixation for symptomatic uterine prolapse. All women underwent independent review and examination, with a mean follow-up of 36 months in the hysterectomy group and 26 months in the hysteropexy group.  The subjective success rate was 86% in the hysterectomy group and 78% in the hysteropexy group (P = 0.70). The objective success rate was 72% and 74%, respectively (P = 1.00). The patient-determined satisfaction rate was 86% in the hysterectomy group and 85% in the hysteropexy group (P = 1.00). The operating time in the hysterectomy group was 91 minutes, compared to 59 minutes in the hysteropexy group (P<0.01). The mean intraoperative blood loss in the hysterectomy group was 402 ml, compared to 198 ml in the hysteropexy group (P<0.01). The sacrospinous hysteropexy is effective in the treatment of uterine prolapse. Vaginal hysterectomy may not be necessary in the surgical treatment of uterine prolapse.  相似文献   
66.
Focal adhesion kinase (FAK) has been implicated in the regulation of cell migration. In addition, FAK expression is increased in a number of highly metastatic tumor cell lines. Therefore, we investigated the role of FAK in regulating migration of prostate carcinoma cell lines with increasing metastatic potential. We show that highly tumorigenic PC3 and DU145 cells exhibit intrinsic migratory capacity, while poorly tumorigenic LNCaP cells require a stimulus to migrate. Increased metastatic potential of PC3 and DU145 cells correlates with increased FAK expression, overall tyrosine phosphorylation and activity, as measured by autophosphorylation of tyrosine 397. However, in PC3 and DU145 cells, FAK autophosphorylation is adhesion dependent whereas a second site of tyrosine phosphorylation, tyrosine 861, a Src specific site, is uncoupled from adhesion-dependent signaling events. Finally, inhibiting the FAK/Src signal transduction pathway by over expressing FRNK (Focal adhesion kinase-Related Non-Kinase), an inhibitor of FAK activation, or treatment with PP2, a Src family kinase inhibitor, significantly inhibited migration of prostate carcinoma cell lines, demonstrating that tumor cell migration continues to be dependent on signals emanating from this pathway.  相似文献   
67.
The pharyngeal aspirates collected from 400 babies at the time of delivery were examined for the presence of bacteria, especially group B streptococci. Aspirates from 79 babies were found to contain viable bacteria, including 4 with group B streptococci; one of these 4 babies developed streptococcal meningitis within 24 hours. The group B streptococci were seen on a Gram-stained film of the aspirate, and were detectable by coagglutination and countercurrent immunoelectrophoresis within 4 hours and by culture after 24 hours. Examination of pharyngeal aspirates may be of value as a screening test for neonatal sepsis.  相似文献   
68.
用鼠肝匀浆(S_9)代谢活化黄曲霉毒素B族和G族,研究它们对流感病毒在恒河猴肾细胞(LLC-MK_2)诱导干扰素-α/β的抑制作用。结果显示活化与未活化的黄曲霉毒素对干扰素诱生都有抑制作用。但代谢活化后,抑制作用增强,抑制作用的大小按B_1>G_1>B_2>G_2顺序排列,显示有结构-活性关系。而干扰素赋予细胞的抗病毒能力并不受黄曲霉毒素的影响。  相似文献   
69.
Examinations of gender differences in alcohol expectancies among college drinkers typically have used self-report measures to assess single expectancy dimensions and often have been confounded by drinking level. This study examined gender differences in alcohol expectancies using 2 assessment methods. College students (N = 88) completed self-report questionnaires, including expectancy likelihood and subjective evaluation endorsements of expectancies, and a computerized expectancy accessibility task. Expectancy accessibility and endorsement were modestly correlated, with higher alcohol consumption and female gender linked to greater accessibility and endorsement of social enhancement expectancies. Gender moderated the relation between consumption and sociability expectancy accessibility; among men, heavier drinking was associated with more rapid activation of expectancies. Findings suggest complexity in associations among these variables and underscore the need to capture the multidimensionality of the expectancy construct and its relationship to alcohol use.  相似文献   
70.
Barnett  MJ; Zussman  WV 《Radiology》1986,160(1):223-225
Granulocytic sarcoma (chloroma), a rare tumor usually associated with myelogenous leukemia, is capable of invading the meninges or brain parenchyma. Radiologic findings in a case of granulocytic sarcoma of the brain, as well as those in 11 previously reported cases of intracranial leukemic masses, are interpreted. On computed tomographic scans, the lesions can appear isodense or hyperdense, edema and necrosis are variable, and there is uniform enhancement following intravenous administration of contrast material. There may be some affinity for the posterior fossa.  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