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   6932篇
  免费   641篇
  国内免费   16篇
耳鼻咽喉   70篇
儿科学   270篇
妇产科学   301篇
基础医学   1017篇
口腔科学   113篇
临床医学   640篇
内科学   1447篇
皮肤病学   231篇
神经病学   708篇
特种医学   165篇
外国民族医学   1篇
外科学   1088篇
综合类   51篇
一般理论   5篇
预防医学   576篇
眼科学   149篇
药学   351篇
中国医学   13篇
肿瘤学   393篇
  2023年   44篇
  2022年   67篇
  2021年   175篇
  2020年   95篇
  2019年   190篇
  2018年   227篇
  2017年   151篇
  2016年   160篇
  2015年   201篇
  2014年   243篇
  2013年   293篇
  2012年   418篇
  2011年   432篇
  2010年   265篇
  2009年   246篇
  2008年   362篇
  2007年   376篇
  2006年   326篇
  2005年   289篇
  2004年   262篇
  2003年   242篇
  2002年   212篇
  2001年   217篇
  2000年   231篇
  1999年   203篇
  1998年   65篇
  1997年   68篇
  1996年   60篇
  1995年   48篇
  1994年   43篇
  1993年   33篇
  1992年   125篇
  1991年   119篇
  1990年   110篇
  1989年   103篇
  1988年   122篇
  1987年   89篇
  1986年   97篇
  1985年   66篇
  1984年   56篇
  1983年   40篇
  1982年   30篇
  1981年   29篇
  1980年   26篇
  1979年   37篇
  1978年   25篇
  1977年   28篇
  1976年   34篇
  1974年   40篇
  1973年   26篇
排序方式: 共有7589条查询结果,搜索用时 31 毫秒
81.
BACKGROUND: Hypogastric artery ligation is a therapeutic option for severe post-partum haemorrhage. Little is known about the outcomes of subsequent fertility and pregnancy. We studied these parameters in women who required hypogastric artery ligation for severe post-partum haemorrhage in our institution over a 13-year period. METHODS: All patients who required hypogastric artery ligation for severe intractable post-partum haemorrhage from January, 1989 to April, 2001 were included. Data were retrieved from medical files and telephone interviews. RESULTS: A total of 68 patients required hypogastric artery ligation during the study period. Seventeen patients had 21 pregnancies with 13 term deliveries, two ectopic pregnancies, three miscarriages, and three abortions. Twenty-eight patients did not want a new pregnancy and one patient refused the interview. Twenty-three (34%) patients were lost to follow up. None of the patients suffered subsequent infertility and pregnancy was achieved in <12 months once planned. Pregnancy outcomes were normal. Fifty-four percent had vaginal deliveries. Three patients suffered a threatened post-partum haemorrhage that was easily treated medically. CONCLUSIONS: This is the largest reported series of pregnancies following hypogastric artery ligation. Hypogastric artery ligation for post-partum bleeding >1 l appears to be a safe procedure that does not impair subsequent fertility and pregnancy outcomes.  相似文献   
82.
83.
Non-surgical management of ectopic pregnancy has recently become an alternative to surgery. We have investigated a pretherapeutic score to define the indication for non-surgical and surgical treatment in 61 patients with ectopic pregnancy. The score was performed before the patients' inclusion in a nonsurgical management scheme. The score used six criteria which were evaluated on a scale from 1 to 3: gestational age, human chorionic gonadotrophin (HCG) level, progesterone level, abdominal pain, haemoperitoneum volume and haematosalpinx diameter (estimated by laparoscopy or transvaginal ultrasound). Three scores, 10, 11 and 12, were studied in order to define a threshold beyond which surgical treatment should be performed. For each one, sensitivity, specificity and positive and negative predictive values were analysed. The success rate of non-surgical treatment was 75% (46/61). For patients undergoing medical treatment with a score less than or equal to 12, the success rate was significantly higher compared with a success rate of 50% when the score was greater than 12. We conclude that a score less than or equal to 12 permits non-surgical management with a success rate of 82%. A score greater than 12 indicates that laparoscopic surgery may be more suitable. The choice between different non-surgical approaches, did not influence the success rate. When ultrasound reveals embryo heart activity, medical treatment is always possible if the score is less than or equal to 12.  相似文献   
84.
85.
In this study, we tested a new square wave microprocessor-controlled red laser with an extremely low peak power output (<3 mW; very low level laser therapy [vLLLT]) in experimental pain in the rat. Acute inflammation was induced by intraplantar injection of carrageenan, chronic inflammation was induced by complete Freund's adjuvant (CFA) and neuropathic pain was produced by sciatic nerve chronic constriction injury (CCI). In our study vLLLT was effective in reducing edema and hyperalgesia in acute and chronic inflammation if administered at the points usually selected for acupuncture. Moreover, spontaneous pain and thermal hyperalgesia were reduced in CCI rats treated with vLLLT In conclusion, vLLLT reduced edema and induced analgesia in experimental plantar pain in rats. We interpret this to mean that enkephalin mRNA level was strongly upregulated in the external layers of the dorsal horn of the spinal cord in CFA and CCI animals, and that vLLLT further increased the mRNA level in single neurons.  相似文献   
86.
We report a 29-year-old patient with a history of asthma that is sometimes accompanied by urticaria, which is related to the ingestion of milk products. Once these were excluded from his diet no symptoms were observed. Skin tests, specific IgE, histamine release, and oral food challenges were positive to cow's milk and its fractions.  相似文献   
87.
We retrospectively analyzed results of unrelated cord blood transplantation (UCBT) in 93 Fanconi anemia (FA) patients. Median age at transplantation was 8.6 years (1-45). The units transplanted were HLA-A, -B, or -DRB1 identical in 12 cases, 1 HLA mismatch in 35 cases, and 2 or 3 HLA differences in 45 cases. The median number of nucleated cells (NC) and CD34+ cells infused of recipient weight was 4.9x10(7)/kg and 1.9x10(5)/kg, respectively. Participating centers selected the preparative regimen of their choice, in 57 patients (61%), it included Fludarabine. Graft-versus-host disease (GVHD) prophylaxis consisted mostly of cyclosporine with prednisone. Cumulative incidence (CI) of neutrophil recovery was 60+/-5% at day +60. In multivariate analysis, Fludarabine containing regimen and NC infused>or=4.9x10(7)/kg were associated with higher probability of recovery. CI of grade II-IV acute and of chronic GVHD (aGVHD, cGVHD) was 32%+/-5% and 16%+/-4%, respectively. Overall survival (OS) was 40%+/-5%. In multivariate analysis, factors associated with favorable outcome were use of Fludarabine in the conditioning regimen, number of NC infused>or=4.9x10(7)/kg, and negative cytomegalovirus (CMV) serology in the recipient. In conclusion, factors easily modifiable such as donor selection and a Fludarabine-containing regimen can considerably improve survival in FA patients given a UCBT. These data are the basis for designing prospective protocols.  相似文献   
88.
This study evaluates the use of local anaesthesia in a subset of patients undergoing uterine thermal balloon endometrial ablation for the treatment of menorrhagia. Out of 51 patients with dysfunctional uterine bleeding, 18 were included for uterine balloon therapy under local anaesthesia. Inclusion criteria were dysfunctional bleeding with absence of organic lesions in the uterine cavity, adequate relaxation and pain control during physical examination and diagnostic hysteroscopy, and patient desire to avoid a general anaesthetic. Paracervical block was performed with 20 ml of dilute 1% lignocaine HCl with epinephrine 1:200,000. Success of the procedure was defined as amenorrhoea, hypomenorrhoea, or eumenorrhoea. The median follow-up period was 13.9 +/- 5 months and 11 patients (61%) had follow-up of >1 year. Treatment led to a significant decrease in menstrual flow, duration, and pad count in all patients (P < 0.0001). No intra- operative complications occurred. A pain scale (level 1-10) was used to evaluate the patients' tolerance of the procedure (mean 3.8 +/- 1.3). In light of these successful and well tolerated procedures, thermal balloon endometrial ablation, utilizing local anaesthesia, appears practical as an office-based therapy.   相似文献   
89.
90.
Mosquitoes collected in the Amazon Basin, near Iquitos, Peru, were evaluated for their susceptibility to epizootic (IAB and IC) and enzootic (ID and IE) strains of Venezuelan equine encephalomyelitis (VEE) virus. After feeding on hamsters with a viremia of approximately 10(8) plaque-forming units of virus per milliliter, Culex (Melanoconion) gnomatus Sallum, Huchings, & Ferreira, Culex (Melanoconion) vomerifer Komp, and Aedes fulvus (Wiedemann) were highly susceptible to infection with all four subtypes of VEE virus (infection rates > or = 87%). Likewise, Psorophora albigenu (Peryassu) and a combination of Mansonia indubitans Dyar & Shannon and Mansonia titillans (Walker) were moderately susceptible to all four strains of VEE virus (infection rates > or = 50%). Although Psorophora cingulata (Fabricius) and Coquillettidia venezuelensis (Theobald) were susceptible to infection with each of the VEE strains, these two species were not efficient transmitters of any of the VEE strains, even after intrathoracic inoculation, indicating the presence of a salivary gland barrier in these species. In contrast to the other species tested, both Culex (Melanoconion) pedroi Sirivanakarn & Belkin and Culex (Culex) coronator Dyar & Knab were nearly refractory to each of the strains of VEE virus tested. Although many of the mosquito species found in this region were competent laboratory vectors of VEE virus, additional studies on biting behavior, mosquito population densities, and vertebrate reservoir hosts of VEE virus are needed to incriminate the principal vector species.  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