全文获取类型
收费全文 | 528篇 |
免费 | 36篇 |
专业分类
儿科学 | 29篇 |
妇产科学 | 6篇 |
基础医学 | 69篇 |
口腔科学 | 14篇 |
临床医学 | 67篇 |
内科学 | 111篇 |
皮肤病学 | 14篇 |
神经病学 | 25篇 |
特种医学 | 131篇 |
外科学 | 14篇 |
综合类 | 13篇 |
预防医学 | 20篇 |
眼科学 | 1篇 |
药学 | 29篇 |
肿瘤学 | 21篇 |
出版年
2022年 | 5篇 |
2021年 | 8篇 |
2020年 | 2篇 |
2019年 | 4篇 |
2018年 | 11篇 |
2017年 | 4篇 |
2016年 | 7篇 |
2015年 | 13篇 |
2014年 | 11篇 |
2013年 | 30篇 |
2012年 | 11篇 |
2011年 | 8篇 |
2010年 | 25篇 |
2009年 | 28篇 |
2008年 | 6篇 |
2007年 | 6篇 |
2006年 | 11篇 |
2005年 | 14篇 |
2004年 | 9篇 |
2003年 | 7篇 |
2002年 | 6篇 |
2001年 | 9篇 |
2000年 | 5篇 |
1999年 | 10篇 |
1998年 | 30篇 |
1997年 | 29篇 |
1996年 | 32篇 |
1995年 | 27篇 |
1994年 | 25篇 |
1993年 | 21篇 |
1992年 | 3篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 17篇 |
1988年 | 12篇 |
1987年 | 12篇 |
1986年 | 9篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 6篇 |
1982年 | 8篇 |
1981年 | 9篇 |
1980年 | 3篇 |
1979年 | 5篇 |
1978年 | 7篇 |
1977年 | 13篇 |
1976年 | 8篇 |
1975年 | 10篇 |
1968年 | 2篇 |
1967年 | 1篇 |
排序方式: 共有564条查询结果,搜索用时 15 毫秒
61.
62.
63.
BACKGROUND: There are obvious advantages to increasing donor retention. However, for reasons of blood safety, certain donors may, in fact, be more desirable to retain than others. “Safe” donors are defined as those who provided a blood donation that was negative on all laboratory screening tests and who subsequently reported no behavioral risks in response to an anonymous survey. This study identifies the most important factors affecting the intention of “safe” donors to provide another donation. STUDY DESIGN AND METHODS: An anonymous survey asking about donation history, sexual history, injecting drug use, and recent donation experience was mailed to 50,162 randomly selected allogeneic donors (including directed donors) who gave blood from April through July or from October through December 1993 at one of the five United States blood centers participating in the Retrovirus Epidemiology Donor Study. Before mailing, questionnaires were coded to designate donors with nonreactive laboratory screening tests at their most recent donation. RESULTS: A total of 34,726 donors (69%) responded, with substantially higher response among repeat donors. According to reported intentions only, the vast majority of “safe” donors indicated a high likelihood of donating again within the next 12 months. Only 3.4 percent reported a low likelihood of donating again. A comparison of those likely to return and those unlikely to return reveals significant differences in demographics and in ratings of the donation experience. A higher proportion of those unlikely to return were first-time donors, minority-group donors, and donors with less education. The highest projected loss among “safe” donors was seen for those who gave a fair to poor assessment of their treatment by blood center staff or of their physical well-being during or after donating. CONCLUSION: These data suggest that efforts to improve donors' perceptions of their donation experience, as well as attention to the physical effects of blood donation, may aid in the retention of both repeat and first-time donors. 相似文献
64.
Data have been collected from 47 centers in Europe and North America on the treatment with porcine factor VIII concentrate of 74 acute bleeding episodes in 65 patients with acquired hemophilia. The median initial anti-human factor VIII auto-antibody inhibitor level was 38 Bethesda unit (BU)/mL (range 1.2 to 1,024) whereas that against porcine was 1 BU/mL (range 0 to 15). The mean initial dose of porcine factor VIII infused was 84 IU/kg, which increased the plasma factor VIII:C activity by 0.85 IU/mL. Therapy was continued for a mean of 8.5 days during which time the average number of infusions was 11. Objective clinical responses were rated as good or excellent in 78% of recipients. Side effects were uncommon; only one patient experienced a severe anaphylactic reaction necessitating the discontinuation of porcine FVIII therapy. After therapy, no increase in the median level of anti- human FVIII or anti-porcine antibody was noted in the group as a whole, although 13 patients showed individual increases in either anti-human or anti-porcine antibody levels or both of more than 10 BU/mL. Of the 7 patients who subsequently rebled, 5 were successfully re-treated and 2 did not respond to further porcine factor VIII treatment. Porcine factor VIII is safe and clinically effective treatment for bleeding episodes associated with acquired hemophilia and should be considered as first-line therapy for patients whose acquired anti-factor VIII:C antibody cross-reacts with porcine factor VIII:C at low levels. 相似文献
65.
Al-Bahry SN Al-Mashani BM Al-Ansari AS Elshafie AE Mahmoud IY 《Asian Pacific journal of tropical medicine》2013,6(9):718-722
ObjectiveTo screen for Escherichia coli (E. coli) resistant to tetracycline, followed by identification of tet efflux genes by polymerase chain reaction (PCR). In addition, detection of tetracycline residues in chicken livers and kidneys were conducted using high performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS-MS).MethodsStrains of E. coli were isolated from samples of chicken colon and screened for tetracycline resistance. Tetracycline genes conferring resistance (Tcr) were detected by polymerase chain reaction (PCR). Most of the isolates were resistant to tetracycline (97.9%).ResultsPCR analysis indicated that Tcr E. coli R-plasmids contained tet(A), tet(B) and a combination of both efflux genes. None of the isolates contained other efflux tet genes tet (C, D, E and Y). High performance liquid chromatography-tandem quadrupole mass spectrometry (HPLC-MS-MS), a sensitive technique, was used to detect residues of chlortetracycline (CTC), oxytetracycline (OTC), doxycycline (DC) in chicken livers and kidneys. The samples containing tetracycline residues were at 0.13-0.65 pg/μL levels.ConclusionsTetracycline and other antibiotics are commonly used in the poultry and meat production industry for prevention of microbial infections. Multiple antibiotic resistant bacteria in Oman have increased to alarming levels, threatening public health, domestic and may have adverse effect on environment. 相似文献
66.
67.
Krutchen AE; Bjarnason H; Stackhouse DJ; Nazarian GK; Magney JE; Hunter DW 《Radiology》1996,200(1):159
68.
Gene Probe Analysis in an Informative Family with Multiple Endocrine Neoplasia Syndrome Type 2A (MEN 2A). Improvement in Carrier Risk Estimation 总被引:2,自引:0,他引:2
MORRISON PJ; HADDEN DR; HUGHES AE; KENNEDY L; RUSSELL CJF; NEVIN NC 《QJM : monthly journal of the Association of Physicians》1991,80(1):597-603
Gene probe analysis of the MEN 2A locus on chromosome 10 hasbeen undertaken using the markers TB10.163, RBP 3 and TB14.34in a large kindred with familial medullary thyroid carcinomas,with or without phaeochromocytomas or primary hyperparathyroidism.A maximum LOD score of 2.97 gave strong evidence of close linkagewith zero recombination. For 12 members of the family so far not known to be affectedby any form of the disease the estimated risk of carrying thegene has been considerably decreased in all but one, whose riskhas been greatly increased. 相似文献
69.
Nabil Fanous Iman Salem Carolyne Tawilé AE Bassas 《CANADIAN JOURNAL OF PLASTIC SURGERY》2004,12(4):193-197
Capsular contracture is one of the major complications of augmentation mammaplasty. A review of 638 augmented breasts in 319 consecutive patients who underwent primary augmentation, with an average follow-up of 17.2 months and without a single case of capsular contracture of any degree to date, is presented, along with a discussion of the surgical technique and complications, and an analysis of measures used to prevent capsular contraction. Each patient received a pair of smooth saline-filled implants (Mentor, USA) placed in the submuscular space through an inframammary incision. In all operated breasts, many of the known measures commonly used for capsular contracture prevention were implemented. As well, a dependent drain was used as the final hemostatic step to prevent blood accumulation in the pocket. Leaving a dependent drain in the dissected pocket overnight, as one of the sequence of measures aimed at eliminating blood accumulation, is believed to be a contributing factor in capsular contracture prevention. 相似文献
70.