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   4248篇
  免费   312篇
  国内免费   10篇
耳鼻咽喉   75篇
儿科学   145篇
妇产科学   80篇
基础医学   583篇
口腔科学   200篇
临床医学   508篇
内科学   556篇
皮肤病学   61篇
神经病学   302篇
特种医学   340篇
外国民族医学   1篇
外科学   515篇
综合类   123篇
一般理论   3篇
预防医学   382篇
眼科学   91篇
药学   268篇
中国医学   6篇
肿瘤学   331篇
  2021年   66篇
  2020年   35篇
  2019年   43篇
  2018年   79篇
  2017年   62篇
  2016年   59篇
  2015年   72篇
  2014年   96篇
  2013年   144篇
  2012年   193篇
  2011年   208篇
  2010年   135篇
  2009年   110篇
  2008年   171篇
  2007年   178篇
  2006年   172篇
  2005年   174篇
  2004年   144篇
  2003年   155篇
  2002年   130篇
  2001年   126篇
  2000年   118篇
  1999年   99篇
  1998年   85篇
  1997年   73篇
  1996年   77篇
  1995年   70篇
  1994年   50篇
  1993年   46篇
  1992年   95篇
  1991年   85篇
  1990年   78篇
  1989年   102篇
  1988年   81篇
  1987年   87篇
  1986年   79篇
  1985年   82篇
  1984年   75篇
  1983年   58篇
  1982年   39篇
  1981年   34篇
  1980年   41篇
  1979年   55篇
  1978年   44篇
  1977年   27篇
  1976年   46篇
  1975年   35篇
  1974年   24篇
  1973年   32篇
  1972年   26篇
排序方式: 共有4570条查询结果,搜索用时 31 毫秒
1.
2.
Ultrasensitive bright field in situ hybridization assays using enzyme metallography (EnzMet) have been developed and validated, but little is known regarding the applicability of EnzMet for immunophenotypic detection of protein via IHC. Superior resolution via discrete metallographic deposits offers the potential for enhancing high-resolution immunophenotyping. Using high-complexity tissue microarrays (TMAs), 88 common solid tumors were evaluated by automated EnzMet (Nanoprobes and Ventana). Targets were chosen to assess the ability of EnzMet to specifically localize encoded antigens in the nucleus (estrogen receptor), cytoplasm (cytokeratins), and cytoplasmic membrane (HER2) in TMAs. Results were compared with conventional IHC diaminobenzidine (DAB) immunostaining. There was full concordance between the EnzMet and conventional IHC results. Furthermore, the EnzMet reaction products did not appreciably diffuse, were dense and sharply defined, and provided excellent high-resolution differentiation of cellular compartments in paraffin sections for the nuclear, cytoplasmic, and cell membrane-localized antigens evaluated. The higher density of elemental silver deposited during enzyme metallography permitted evaluation of core immunophenotypes at a relatively low magnification, allowing more tissue to be screened in an efficient manner. This preliminary study shows the utility of using enzyme metallography for high-resolution immunophenotyping in TMAs.  相似文献   
3.
4.
Alcohol and the adolescent trauma population   总被引:4,自引:0,他引:4  
Trauma is the leading killer of children and adolescents between 1 and 21 years of age. Alcohol-impaired driving represents the single greatest cause of mortality and morbidity of children over the age of 6. We retrospectively reviewed 878 consecutive adolescent (age range, 16 to 20 years) trauma admissions for blood alcohol concentration (BAC). Four hundred sixty-seven patients had BAC drawn, 258 were BAC-negative (group I), 209 (48%) were BAC-positive (group II). The adolescent drinkers were then compared with a group of 748 adult drinkers (group III). Groups I and II differ in sex, age, time of day of the accident, Injury Severity Score, Glasgow Coma Score, and Revised Trauma Score, whereas group II and III differ by type of accident, type of injury, socioeconomic factors (bad debt), time of day of the injury, and BAC. There were no significant differences in TRISS predicted survival, actual survival, nor mean length of stay. We conclude that (1) alcohol is a significant contributor to injury during adolescence, and (2) adolescent drinkers differ from adult drinkers in their habits, demographics, and socioeconomic status. These socioeconomic differences have implications for the access to and cost-effectiveness of interventions.  相似文献   
5.
Summary: A prospective, randomized, double-blind trial was conducted to assess contribution to postoperative analgesia of intermittent instillation of 0.25% bupivacaine beneath the rectus sheath in 70 women delivered by lower uterine segment Caesarean section. The operations were performed via a Pfannenstiel incision under spinal anaesthesia. Background intravenous narcotic analgesia was provided with a patient controlled analgesia system (PCAS) using a standard morphine regimen.
Overall (44 hr) mean morphine consumption was significantly greater in the placebo (saline) group compared to the treatment group (84.2 mg versus 63.3 mg. Two tailed t test p<0.001). The most significant intergroup differences in narcotic use were found in the first 4 hours and between 24 and 36 hours after commencing PCAS (Two tailed t test p=0.014 and 0.003 respectively).
Subjective pain scores were assessed with a 10 cm visual analogue scale (VAS). The mean peak VAS score was greater in controls (5.37) than the treatment group (4.25) between 18 and 24 hours postoperatively (Mann-Whitney U=424, p=0.027). There were no intergroup differences in pain scores for any other time period. The overall incidence of nausea was lower in the treatment group compared to the control group (Chi squared with Yates' correction p=0.046) and a lower degree of sedation was seen in those receiving bupivacaine between 4 and 8 hours after commencing PCAS (Mann-Whitney U=427, p=0.028). No differences in other narcotic related side-effects (vomiting and pruritus) were shown between groups.
Regular instillation of 0.25% bupivacaine beneath the rectus sheath of women delivered by Caesarean section reduces their morphine requirements by 25% in the 44 hours after operation, with an associated reduction in both nausea and early sedation.  相似文献   
6.
The 1980s saw a retrenchment of the ideology that government intervention could solve the problems of inadequate access to health services in rural areas. Increased emphasis was placed on an ideology that promoted deregulation and competitive market solutions. During the 1980s, the gap in the availability of physicians in metropolitan versus nonmetropolitan areas widened. Also during that time period, the gap between metropolitan and nonmetropolitan populations' utilization of physician services widened. In addition, many indicators of the health status of nonmetropolitan residents versus metropolitan residents worsened during the 1980s. As we enter the 1990s, concern about equitable access to needed health care services and for the vulnerability and fragility of rural health systems has resurfaced. A number of national policies and a research agenda to improve accessibility and availability of health services in rural areas are being considered.  相似文献   
7.
8.
9.
Significant progress has been made in the 1980s in early-stage vulvovaginal rhabdomyosarcoma, diethylstilbestrol (DES) clear cell adenocarcinoma of the vagina, and unilateral germ cell tumors of the ovary. In an early state of vulvovaginal rhabdomyosarcoma, systemic vincristine, dactinomycin, and cyclophosphamide (VAC) chemotherapy followed by local excision or local radiation results in a high cure rate with retention of future fertility. Similarly, early-stage DES-related adenocarcinoma of the vagina treated by wide local excision and localized vaginal radiation also results in retention of fertility and a high cure rate. Finally, significant progress has been made in unilateral germ cell tumors of the ovary in which surgical treatment by unilateral salpingo-oophorectomy followed by cisplatin, etoposide, and bleomycin results in not only high cure rates and retention of fertility but will probably be standard therapy for all germ cell tumors of the ovary, including dysgerminoma, a disease most frequently treated in the past by radiation therapy with loss of subsequent fertility.  相似文献   
10.
We present a case of a 38-year-old man with a unilateral intra-abdominal testicle and undesired fertility in whom orchiectomy and contralateral vasectomy were performed laparoscopically. Urologists have been using diagnostic laparoscopy in patients with nonpalpable testes to plan the definitive procedure when the testicle is present, and to avoid laparotomy in cases of testicular absence. This case of laparoscopic orchiectomy and vasectomy demonstrates that operative laparoscopy allows another subset of patients with cryptorchidism to avoid open laparotomy.  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