全文获取类型
收费全文 | 10560篇 |
免费 | 708篇 |
国内免费 | 50篇 |
专业分类
耳鼻咽喉 | 55篇 |
儿科学 | 277篇 |
妇产科学 | 184篇 |
基础医学 | 1502篇 |
口腔科学 | 202篇 |
临床医学 | 1012篇 |
内科学 | 2378篇 |
皮肤病学 | 200篇 |
神经病学 | 830篇 |
特种医学 | 402篇 |
外科学 | 1625篇 |
综合类 | 91篇 |
一般理论 | 4篇 |
预防医学 | 848篇 |
眼科学 | 333篇 |
药学 | 654篇 |
中国医学 | 10篇 |
肿瘤学 | 711篇 |
出版年
2023年 | 35篇 |
2022年 | 162篇 |
2021年 | 276篇 |
2020年 | 118篇 |
2019年 | 213篇 |
2018年 | 282篇 |
2017年 | 184篇 |
2016年 | 192篇 |
2015年 | 227篇 |
2014年 | 293篇 |
2013年 | 465篇 |
2012年 | 703篇 |
2011年 | 734篇 |
2010年 | 418篇 |
2009年 | 359篇 |
2008年 | 633篇 |
2007年 | 692篇 |
2006年 | 616篇 |
2005年 | 696篇 |
2004年 | 616篇 |
2003年 | 567篇 |
2002年 | 574篇 |
2001年 | 116篇 |
2000年 | 133篇 |
1999年 | 140篇 |
1998年 | 133篇 |
1997年 | 122篇 |
1996年 | 86篇 |
1995年 | 100篇 |
1994年 | 83篇 |
1993年 | 91篇 |
1992年 | 94篇 |
1991年 | 108篇 |
1990年 | 83篇 |
1989年 | 87篇 |
1988年 | 74篇 |
1987年 | 70篇 |
1986年 | 51篇 |
1985年 | 54篇 |
1984年 | 63篇 |
1983年 | 55篇 |
1982年 | 55篇 |
1981年 | 47篇 |
1980年 | 45篇 |
1979年 | 25篇 |
1978年 | 29篇 |
1977年 | 30篇 |
1974年 | 19篇 |
1973年 | 21篇 |
1972年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Anela Stanic Denis Rybin Francis Cannata Carole Hohl Jennifer Brody Jessie Gaeta 《AIDS care》2021,33(1):1-9
ABSTRACT The lack of stable housing can impair access and continuity of care for patients living with human immunodeficiency virus (HIV). This study investigated the relationship between housing status assessed at multiple time points and several core HIV-related outcomes within the same group of HIV patients experiencing homelessness. Patients with consistently stable housing (CSH) during the year were compared to patients who lacked CSH (non-CSH group). The study outcomes included HIV viral load (VL), CD4 counts, and health care utilization. Multivariable and propensity weighted analyses were used to assess outcomes adjusting for potential group differences. Of 208 patients, 88 (42%) had CSH and 120 (58%) were non-CSH. Patients with CSH had significantly higher proportion of VL suppression and higher mean CD4 counts. The frequency of nurse visits in the CSH group was less than a half of that in the non-CSH group. Patients with CSH were less likely to be admitted to the medical respite facility, and if admitted, their length of stay was about a half of that for the non-CSH group. Our study findings show that patients with CSH had significantly better HIV virologic control and immune status as well as improved health care utilization. 相似文献
2.
Postpartum fatigue is a normal condition that most women experience. Breastfeeding is often associated in women's minds as contributing to the feeling of overall perceived fatigue, and many women indicate that they have ceased breastfeeding because of fatigue. However, the relationship between feeding choice and perceived fatigue has never been established. Two hundred and fifty-three women participated in a study examining whether perceived fatigue differed for bottle-feeding and breastfeeding women at 3 different times during the postpartum period (2-4 days, 6 weeks, and 12 weeks postpartum). Results showed no significant differences for these 2 groups, suggesting that perceived fatigue during the postpartum period is not dependent on feeding choice. Additional analyses examining other variables with a potential effect were nonsignificant. Because perceived physical fatigue does not appear to be dependent on feeding choice, women should be prepared for the feeling of perceived fatigue during the postpartum period while at the same time be reassured that feeding choice is not correlated. 相似文献
3.
4.
5.
Denis Nissim-Sabat William H. Farr Kathleen McCune Melanie Stith 《Community mental health journal》1986,22(2):160-165
This study represents the first of a two-stage project. The first phase of the study examined the funding sources for the 40 Community Services Boards in Virginia. Data provided from the Department of Mental Health and Mental Retardation in Virginia examined fee collections which are comprised of direct client, commercial insurance, Medicaid and Medicare. An analysis of quarterly reports from 1982 to 1984 revealed that Medicaid collections have decreased significantly, while commercial insurance reimbursements have increased significantly. These results, although limited to data from Virginia, point to the need to examine if these shifts are occurring nation-wide, and to determine if the shift toward commercial insurance is impacting upon the delivery of services in Community Mental Health Centers. 相似文献
6.
7.
Denis Mariano-Goulart Laurent Déchaux Fran?ois Rouzet Eric Barbotte Charles Caderas de Kerleau Michel Rossi Dominique Le Guludec 《Journal of nuclear medicine》2007,48(9):1416-1423
This study aimed to assess the ability of global and local systolic parameters measured with gated blood-pool SPECT (GBPS) to diagnose and characterize the severity of diffuse or localized arrhythmogenic right ventricular dysplasia (ARVD). METHODS: Fifty-nine subjects with symptomatic ventricular arrhythmias were prospectively included in the study. With the International Society and Federation of Cardiology criteria for ARVD as a gold standard, these subjects were classified as subjects without ARVD (21 control subjects) and patients with localized ARVD (16 patients) or diffuse ARVD (22 patients). Right ventricular volumes, right ventricular ejection fractions (EF), the SD of local EF (sigma-EF), and the SD of the local times of end systole (sigma-TES) were computed from GBPS data and compared among the groups in the study population. RESULTS: sigma-EF did not differ between control subjects and patients with diffuse or localized ARVD. Right ventricular EF and volumes differed between patients with diffuse ARVD and control subjects, with similar areas under the receiver-operating-characteristic curves, but right ventricular EF and volumes failed to differentiate patients with localized ARVD. In contrast, sigma-TES differed between patients with diffuse or localized ARVD and control subjects. Regression analysis showed that the systolic parameter most strongly associated with the diagnosis of ARVD was sigma-TES. The probabilities of a randomly chosen patient in the diffuse ARVD group and of a randomly chosen patient in the localized ARVD group having sigma-TES values greater than that of a randomly chosen control subject were 98.5% and 96.7%, respectively. For the diagnosis of localized ARVD, a threshold of 80 ms for sigma-TES corresponded to sensitivity, specificity, and positive and negative predictive values of 100%, 81%, 80%, and 100%, respectively. CONCLUSION: With GBPS, both diffuse ARVD and localized ARVD can be accurately diagnosed by computing sigma-TES for all of the pixels on the surface of the right ventricle. 相似文献
8.
Margaret J Bowers Nick J Orr Si Dempsey H Denis Alexander 《Blood coagulation & fibrinolysis》2006,17(5):409-411
We present a case of Bernard Soulier syndrome in a 9-year-old boy caused by a novel genetic mutation. This child was shown to be homozygous for a single nucleotide deletion (c.1077delG) in the GP1BA gene not previously reported. Clinically, the boy has become refractory to platelet transfusions with both allo-antibodies and iso-antibodies and a massive transfusion requirement for ongoing haemorrhage. We describe the critical role that the blood product transfusion continues to play in the management of Bernard Soulier syndrome and discuss therapeutic options in these patients. 相似文献
9.
Chretien Marie Francoise; Lebouvier Brigitte; Denis Alain; Chappard Daniel 《Human reproduction (Oxford, England)》1998,13(10):2767-2771
A cytomorphometric analysis of superficial vaginal cells inwomen in three groups of different types of hormonal concentrationwas made. There were 15 women in each group. Group I was studiedduring a natural cycle, group II under oral contraceptive therapyand group III during an in-vitro fertilization (IVF) stimulationprotocol. Morphometric parameters were measured on an imageanalyser. The area, perimeter and several form factors weremeasured separately for nuclei and cytoplasm. The nucleus:cytoplasmicratio was also determined. The cytoplasmic area was significantlyreduced in group II and was associated with a statisticallysignificant reduction of the nuclear area. The nucleus:cytoplasmicratio appeared significantly increased in group II and reducedin group III. Low oestradiol impregnation obtained with an oralminidosed contraceptive interfered with vaginal cell maturation.High oestradiol concentrations obtained during IVF protocolsinduced marked nuclear pycnosis but did not induce supra-physiologicalcell enlargement. Maximal cell size is genetically regulatedaccording to Driesch's law of volume invariance and hormonalover-stimulation has no effect on cell size. The nucleus:cytoplasmicratio appears to be a powerful parameter reflecting the oppositeeffects of hormones on cell compartments. 相似文献
10.
Authors analyse the anatomic findings in the anterior chamber cleavage syndrome and emphasize necessity of genetics (heredity being well known) and supervision for detecting glaucoma which occurs in about 50% of these patients and usually appears between 5 and 30 years of age. (Juvenile glaucoma). 相似文献