全文获取类型
收费全文 | 1001篇 |
免费 | 76篇 |
国内免费 | 29篇 |
专业分类
儿科学 | 63篇 |
妇产科学 | 18篇 |
基础医学 | 83篇 |
口腔科学 | 49篇 |
临床医学 | 118篇 |
内科学 | 215篇 |
皮肤病学 | 13篇 |
神经病学 | 18篇 |
特种医学 | 254篇 |
外科学 | 110篇 |
综合类 | 19篇 |
预防医学 | 41篇 |
眼科学 | 11篇 |
药学 | 49篇 |
肿瘤学 | 45篇 |
出版年
2023年 | 3篇 |
2021年 | 8篇 |
2020年 | 3篇 |
2019年 | 8篇 |
2018年 | 21篇 |
2017年 | 12篇 |
2016年 | 9篇 |
2015年 | 19篇 |
2014年 | 24篇 |
2013年 | 17篇 |
2012年 | 12篇 |
2011年 | 20篇 |
2010年 | 40篇 |
2009年 | 23篇 |
2008年 | 21篇 |
2007年 | 32篇 |
2006年 | 34篇 |
2005年 | 22篇 |
2004年 | 19篇 |
2003年 | 26篇 |
2002年 | 16篇 |
2001年 | 16篇 |
2000年 | 13篇 |
1999年 | 21篇 |
1998年 | 63篇 |
1997年 | 72篇 |
1996年 | 78篇 |
1995年 | 47篇 |
1994年 | 38篇 |
1993年 | 43篇 |
1992年 | 20篇 |
1991年 | 15篇 |
1990年 | 21篇 |
1989年 | 42篇 |
1988年 | 42篇 |
1987年 | 30篇 |
1986年 | 32篇 |
1985年 | 31篇 |
1984年 | 8篇 |
1983年 | 10篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1980年 | 12篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 13篇 |
1976年 | 10篇 |
1975年 | 6篇 |
1966年 | 1篇 |
1950年 | 1篇 |
排序方式: 共有1106条查询结果,搜索用时 8 毫秒
1.
2.
OBJECTIVE: To examine the relative importance of husband, wife, and couple factors as determinants of sterilization method choice. DESIGN: Married couples seeking sterilization interviewed before surgery and again 1 year later. SETTING: Kaiser Permanente Medical Care Program subscribers seeking care at the Kaiser Foundation Hospital, Santa Clara, California. PARTICIPANTS: Two hundred married women seeking a tubal sterilization and their husbands and 200 married men seeking a vasectomy and their wives. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Sterilization method chosen. RESULTS: In a logistic regression model, nine predictor variables correctly classified 94.9% of 395 couples (P less than 0.000). CONCLUSIONS: The choice of a sterilization method is achieved primarily through processes that involve both spouses. The motivations of both husband and wife, their mutual influence and communication, their present pattern of contraceptive use, and what they know about the satisfactions or dissatisfactions of other people who have had sterilizations are all factors that should be taken into account when the clinician helps a patient make the method-choice decision. 相似文献
3.
4.
In a prospective, randomized study of insemination with donor semen,
intracervical insemination by straw was compared with insemination using a
cervical cap with an intracervical reservoir. A total of 91 patients
completed 486 treatment cycles. There were no significant differences in
age, parity, indication for insemination by donor, or method of cycle
monitoring between women who became pregnant and those who did not conceive
with either insemination method. In 236 standard intracervical insemination
cycles, 14 patients became pregnant (5.9% per cycle), whereas 38 patients
conceived in 250 cervical cap cycles (15.2% per cycle). Both the crude
pregnancy rates and the cumulative pregnancy rates calculated by the
Kaplan-Meier life-table method were significantly different (chi(2)-test, P
< 0.001, and log-rank test, P < 0.005 respectively). Pregnancy rates
in artificial insemination with cryopreserved donor semen may be improved
by the use of a cervical cap when compared to cervical insemination by
straw. The use of the cervical cap may prolong the exposure of the
spermatozoa to the cervical mucus and prevent the backflow of semen into
the vagina.
相似文献
5.
6.
Meniscal abnormalities: prospective correlation of double-contrast arthrography and arthroscopy 总被引:2,自引:0,他引:2
In a prospective study conducted over a 12-month period, 30 patients underwent double-contrast arthrography of the knee followed by arthroscopic study. An 80% correlation rate was found between results. Arthrography had a higher rate of accuracy (93%) than arthroscopy (84%) and had a 7% false-positive and 0% false-negative rate. A commonly overlooked arthrographic sign--the triple-S or stuck sail sign--was 91% accurate in the prediction of meniscal tears. The complementary nature of the two examinations is discussed. 相似文献
7.
8.
The development of both adenocarcinoma of the jejunum and in situ squamous carcinoma of the oesophagus in an adult coeliac patient is described. Good evidence that adenocarcinoma of jejunum occurs more frequently in patients with coeliac disease has recently become available though this association has been suggested for some time. While oesophageal carcinoma has long been associated with coeliac disease, in situ carcinoma of oesophagus has not been previously described in these circumstances. We feel that the risk of this complication, as calculated from published series, warrants a screening programme for oesophageal malignancy in adult coeliacs. 相似文献
9.
10.
A 50-kDa membrane protein mediates sialic acid-independent binding and infection of conjunctival cells by adenovirus type 37 总被引:6,自引:0,他引:6
The ocular tropism of adenovirus type 37 (Ad37) does not correlate with the wide distribution of the 46-kDa coxsackievirus and adenovirus receptor (CAR), the major receptor for most adenovirus serotypes. We previously found that Ad37 infects and binds well to conjunctival cells (Chang C), but poorly to lung epithelial (A549) cells that express CAR and hypothesized that this serotype uses a distinct receptor that is selectively expressed on conjunctival cells. To test this, we produced particles of a fiber-deleted Ad5 vector containing the Ad37 fiber protein. The "pseudotyped" vector infected Chang C cells better than A549 cells using a CAR-independent pathway. Ad37 binding was calcium-dependent and was abolished by protease digestion of cell surface proteins. Using a virus overlay protein blot assay (VOPBA), we detected calcium-dependent Ad37 binding to 50- and 60-kDa membrane proteins on permissive Chang C cells. In contrast, calcium-dependent binding was detected with only the 60-kDa protein on nonpermissive A549 cells. Ad19p, a closely related serotype that failed to bind to conjunctival cells, recognized the 60-kDa, but not the 50-kDa, protein. Ad37 has been reported to use sialic acid instead of CAR as a cell receptor on A549 cells. Pretreatment of Chang C cells with neuraminidase abolished Ad37 binding to only the 60-kDa protein, suggesting that sialic acid mediates Ad37 binding to the 60-kDa protein. The pseudotyped Ad37 vector was also able to infect neuraminidase-treated Chang C cells. Thus, subgroup D adenoviral binding to the 50-kDa protein is calcium-dependent and cell type- and serotype-specific, whereas binding to the 60-kDa protein is not necessary for infection of conjunctival cells. Together, these data suggest that the 50-kDa protein is the major receptor for Ad37 on conjunctival cells. 相似文献