全文获取类型
收费全文 | 2796篇 |
免费 | 164篇 |
国内免费 | 73篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 67篇 |
妇产科学 | 81篇 |
基础医学 | 476篇 |
口腔科学 | 30篇 |
临床医学 | 302篇 |
内科学 | 600篇 |
皮肤病学 | 71篇 |
神经病学 | 129篇 |
特种医学 | 377篇 |
外科学 | 316篇 |
综合类 | 21篇 |
预防医学 | 125篇 |
眼科学 | 47篇 |
药学 | 182篇 |
中国医学 | 7篇 |
肿瘤学 | 187篇 |
出版年
2023年 | 9篇 |
2022年 | 57篇 |
2021年 | 65篇 |
2020年 | 34篇 |
2019年 | 38篇 |
2018年 | 73篇 |
2017年 | 49篇 |
2016年 | 78篇 |
2015年 | 88篇 |
2014年 | 116篇 |
2013年 | 144篇 |
2012年 | 185篇 |
2011年 | 187篇 |
2010年 | 119篇 |
2009年 | 114篇 |
2008年 | 142篇 |
2007年 | 156篇 |
2006年 | 106篇 |
2005年 | 127篇 |
2004年 | 98篇 |
2003年 | 91篇 |
2002年 | 86篇 |
2001年 | 97篇 |
2000年 | 86篇 |
1999年 | 59篇 |
1998年 | 69篇 |
1997年 | 63篇 |
1996年 | 44篇 |
1995年 | 38篇 |
1994年 | 32篇 |
1993年 | 38篇 |
1992年 | 26篇 |
1991年 | 23篇 |
1990年 | 22篇 |
1989年 | 38篇 |
1988年 | 25篇 |
1987年 | 31篇 |
1986年 | 15篇 |
1985年 | 21篇 |
1984年 | 19篇 |
1983年 | 20篇 |
1982年 | 19篇 |
1981年 | 17篇 |
1980年 | 20篇 |
1979年 | 5篇 |
1978年 | 12篇 |
1977年 | 9篇 |
1976年 | 9篇 |
1975年 | 5篇 |
1974年 | 2篇 |
排序方式: 共有3033条查询结果,搜索用时 15 毫秒
1.
The authors studied the cumulative probability of pregnancy for up to 4 consecutive embryo transfer (ET) cycles with ICSI performed for male factor. Transfers could be either fresh or frozen. The clinical pregnancy rate (PR) for the first 4 cycles were similar [44% (61/366); 31% (44/138); 45% (14/31); 44% (4/9)]. Delivery rates were also similar. There was a lower PR on the second retrieval vs. the first retrieval (47% vs. 29%), but this may be related to most of the second retrievals occurring in the second transfer cycle (67%, 31/55); this may be explained by women who were poor responders and required another retrieval without a frozen ET. The majority of transfers in cycle 1 were fresh, whereas cycles 2-4 used primarily frozen-thawed embryos. These data should be helpful for patients requiring IVF with ICSI in deciding to continue with more IVF cycles or consider other 相似文献
2.
3.
Kevin L. Greason M.D. Jose A. Acosta M.D. Thomas J. Magrino M.D. Moogil Choe M.D. 《Diseases of the colon and rectum》1996,39(6):702-704
PURPOSE: This study was undertaken to clarify the importance of bleeding vascular ectasia of the colon as the etiology of massive lower gastrointestinal hemorrhage in patients 40 years of age or younger. METHODS: An otherwise healthy 21-year-old male was admitted to a tertiary medical center with massive lower gastrointestinal hemorrhage. Technetium-labeled red blood cell scan, selective visceral angiography, and colonoscopy identified the source of bleeding as vascular abnormality of the descending colon. Segmental colonic resection was performed. RESULTS: Histologic review of the specimen demonstrated a vascular ectasia. The patient recovered uneventfully and has had no further stigmata of hemorrhage. A review of the literature was undertaken to make clear the significance of vascular ectasia as the source for massive colonic hemorrhage in the young adult. CONCLUSION: This is the first report that documents histologically a vascular ectasia as the source of massive lower gastrointestinal hemorrhage in an otherwise healthy patient less than 40 years of age. Vascular ectasia is an uncommon cause of lower gastrointestinal hemorrhage in the young adult.The Chief, Bureau of Medicine and Surgery, Navy Department, Washington, DC, Clinical Investigation Program sponsored this report #84-16-1968-532, as required by HSETCINST 6000.41A. The views expressed in this article are those of the authors and do not reflect the official policy or position of the Department of the Navy, Department of Defense, or the United States Government. 相似文献
4.
Outflow of aqueous humor following cyclodialysis or ciliochoroidal detachment in rabbit 总被引:1,自引:0,他引:1
Cyclodialysis and ciliochoroidal detachment were performed in three eyes of three rabbits and in three eyes of another three rabbits, respectively. After aspiration of the aqueous humor, 0.1 ml of 10% sodium fluorescein was injected intracamerally, and the eyeball was enucleated between 30 minutes and one hour after injection and prepared for fluorescence microscopy. Sodium fluorescein concentrations in the supraciliary space were much greater in the group with cyclodialysis or ciliochoroidal detachment than in the normal control group. These results suggest that (1) in the eye with cyclodialysis, the aqueous humor may freely gain access to the supraciliary space through the cleft between the anterior chamber and the supraciliary space and then be removed rapidly and (2) in the eye with ciliochoroidal detachment, the aqueous humor may pass through the uveoscleral outflow pathway. 相似文献
5.
Choe Seong Wook MD Cho Wan Ik MD Lee Chang Kyun MD † Seo Seong Jun MD 《Dermatologic surgery》2005,31(5):502-508
BACKGROUND: Masseteric muscle hypertrophy is an uncommon dition represented as a swelling of the masseter muscle. Recent reports have demonstrated the successful use of botulinum in the treatment of masseteric hypertrophy. OBJECTIVE: This study was a prospective trial to evaluate the effectiveness of botulinum toxin type A (Botox) in the treatment of masseteric muscle hypertrophy according to doses of 10, 20, and 30 U. MATERIALS AND METHODS: Twenty-two patients were referred to the dermatologic clinic for the management of masseteric muscle hypertrophy. Ultrasonographic measurements of the thickness of the masseter muscle were performed, and clinical photographs were taken before treatment and 1, 2, 3, 4, 6, and 9 months after the treatment. RESULTS. The median values of percentage reduction of muscle mass were 10.3%, 16.5%, 23.7%, 24.7%, 21.6%, 16.5% in the 10 U group; 11.9%, 18.8%, 24.8%, 27.7%, 26.7%, and 21.8% in the 20 U group; and 12.0%, 19.4%, 25.0%, 27.8%, 37.8%, and 24.1% in the 30 U group. CONCLUSION. The adequate dose of botulinum toxin type A for treatment of masseteric muscle hypertrophy should be above 20 U. The effect of botulinum toxin type A is maintained for at least 9 months as the treatment of masseteric muscle hypertrophy. 相似文献
6.
Parvalbumin 3 is an Abundant Ca2+ Buffer in Hair Cells 总被引:3,自引:0,他引:3
Stefan Heller Andrea M. Bell Charlotte S. Denis Yong Choe A.J. Hudspeth 《Journal of the Association for Research in Otolaryngology》2002,3(4):488-498
Ca2+ signaling serves distinct purposes in different parts of a hair cell. The Ca2+ concentration in stereocilia regulates
adaptation and, through rapid transduction-channel reclosure, underlies amplification of mechanical signals. In presynaptic
active zones, Ca2+ mediates the exocytotic release of afferent neurotransmitter. At efferent synapses, Ca2+ activates the
K+ channels that dominate the inhibitory postsynaptic potential. A copious supply of diffusible protein buffer isolates the
three signals by restricting the spread of free Ca2+ and limiting the duration of its action. Using cDNA subtraction and a
gene expression assay based on in situ hybridization, we detected abundant expression of mRNAs encoding the Ca2+ buffer parvalbumin
3 in bullfrog saccular and chicken cochlear hair cells. We cloned cDNAs encoding this protein from the corresponding inner-ear
libraries and raised antisera against recombinant bullfrog parvalbumin 3. Immunohistochemical labeling indicated that parvalbumin
3 is a prominent Ca2+-binding protein in the compact, cylindrical hair cells of the bullfrog's sacculus, and occurs as well
in the narrow, peanut-shaped hair cells of that organ. Using quantitative Western blot analysis, we ascertained that the concentration
of parvalbumin 3 in saccular hair cells is approximately 3 mM. Parvalbumin 3 is therefore a significant mobile Ca2+ buffer,
and perhaps the dominant buffer, in many types of hair cell. Moreover, parvalbumin 3 provides an early marker for developing
hair cells in the frog, chicken, and zebrafish. 相似文献
7.
8.
We constructed a pubovaginal sling using the Gore-tex Soft Tissue Patch and 2-0 polytetrafluoroethlene (PTFE) suspension suture and placed it in 122 consecutive incontinent women with urethral hypermobility and/or intrinsic sphincter deficiency. We performed a retrospective outcome analysis using a questionnaire-based telephone survey. The mean follow-up period was 24.4 months. Stress incontinence was cured in 88% of patients (equally effective in type II and type III incontinence), de novo postoperative urinary frequency occurred in 32% of cases, and preoperative urinary frequency resolved postoperatively in 51% of patients. Significant urinary obstruction occurred in 5% of patients. Vaginal granulation tissue with exposed sling occurred in 4% of patients. There was no urethral or bladder erosion. The treatment of female stress incontinence with a PTFE sling is effective and durable with minimal complications. Furthermore, this technique addresses many of the presumed technical shortcomings of endoscopic needle suspensions. 相似文献
9.
The proliferative activity of gastric adenomas from 18 patients (42 endoscopic procedures) was compared with follow-up results. These cases were gastric adenomas proven by follow-up with repeated endoscopic procedures for more than 2 years, or were confirmed as gastric adenocarcinoma thereafter by histopathologic examination. Among the eighteen cases, nine showed carcinoma in the subsequent biopsies (group 1) and the remaining nine did not result in carcinoma (group 2). The proliferating cell nuclear antigen (PCNA) positivity rates of the two groups were significantly different (P < 0.01). The average PCNA positivity in group 1 was 33.1%, while it was 10.0% in group 2. The risk of developing carcinoma increased as the PCNA positivity increased: 0% in the low PCNA positivity group, 41% in the mid-positivity group and 89% in the high positivity group. We concluded that growth fraction could be taken into account as one of the most important prognostic factors for gastric adenoma, and accordingly repeated endoscopic biopsies with close follow-up should be carried out especially in the high PCNA positivity group. 相似文献
10.
Peter R. Martin Sondra Levin Giovanni Impeduglia Yoomi Choe John Karanian Anil B. Mukherjee 《Psychopharmacology》1989,97(2):253-256
To determine whether prenatal thiamine deficiency, a frequent concomitant of alcoholism, reduces the response to ethanol during adulthood in the rat as does ethanol exposure in utero (Abel et al. 1981), pregnant Sprague-Dawley rats received either control or thiamine deficient diets together with daily injections of the thiamine antagonist pyrithiamine. At 7 months of age, male offspring were exposed to precisely regulated ethanol vapor concentrations in an inhalation chamber for 24 h and blood ethanol concentrations (BECs) and ethanol-induced intoxication were determined. Prenatally thiamine deficient rats and controls were indistinguishable in terms of appearance, body and liver weights, and the ratios of liver to body weight and brain to liver weight. However, total body water was significantly greater, and BECs and behavioral impairment were decreased, in the experimental rats. These findings indicate that prenatal thiamine deprivation is associated with reduced pharmacologic effect of ethanol as a result of increases in its volume of distribution and rate of metabolism. 相似文献