全文获取类型
收费全文 | 3413篇 |
免费 | 199篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 86篇 |
儿科学 | 201篇 |
妇产科学 | 73篇 |
基础医学 | 538篇 |
口腔科学 | 104篇 |
临床医学 | 270篇 |
内科学 | 613篇 |
皮肤病学 | 91篇 |
神经病学 | 246篇 |
特种医学 | 163篇 |
外科学 | 309篇 |
综合类 | 82篇 |
一般理论 | 1篇 |
预防医学 | 163篇 |
眼科学 | 171篇 |
药学 | 234篇 |
中国医学 | 25篇 |
肿瘤学 | 251篇 |
出版年
2023年 | 31篇 |
2022年 | 54篇 |
2021年 | 113篇 |
2020年 | 73篇 |
2019年 | 95篇 |
2018年 | 89篇 |
2017年 | 68篇 |
2016年 | 96篇 |
2015年 | 107篇 |
2014年 | 132篇 |
2013年 | 177篇 |
2012年 | 236篇 |
2011年 | 276篇 |
2010年 | 153篇 |
2009年 | 148篇 |
2008年 | 201篇 |
2007年 | 202篇 |
2006年 | 152篇 |
2005年 | 187篇 |
2004年 | 145篇 |
2003年 | 140篇 |
2002年 | 126篇 |
2001年 | 92篇 |
2000年 | 58篇 |
1999年 | 42篇 |
1998年 | 23篇 |
1997年 | 23篇 |
1996年 | 13篇 |
1995年 | 13篇 |
1994年 | 9篇 |
1993年 | 8篇 |
1992年 | 17篇 |
1991年 | 26篇 |
1990年 | 21篇 |
1989年 | 14篇 |
1988年 | 23篇 |
1987年 | 24篇 |
1986年 | 15篇 |
1985年 | 22篇 |
1984年 | 11篇 |
1983年 | 12篇 |
1982年 | 8篇 |
1980年 | 15篇 |
1979年 | 11篇 |
1977年 | 13篇 |
1976年 | 11篇 |
1975年 | 16篇 |
1974年 | 10篇 |
1972年 | 9篇 |
1971年 | 12篇 |
排序方式: 共有3621条查询结果,搜索用时 15 毫秒
21.
22.
P. Hazarika D. R. Nayak K. Pujary L. Rao 《Indian journal of otolaryngology and head and neck surgery》2003,55(1):34-38
Sckhwannoma is a benign tumor arising from the Schwann cells of nerve sheath.Through they arise more commonly in the head
and neck than other regions, a through search in the liturature including medline revealed only about 47 reported cases of
schwannoma in the paranasal sinuses of which the maxillary sinus involvement is more common. We report three cases of schwannoma
arising from unusual sites in the paranasal sinuses with different modes of presttation each requiring a specific approach
for surgical excision Transnasal endoscopic approach in combination with vonventional approaches is of immense value in the
surgical management of these benign lessions of the paranasal sinuses. 相似文献
23.
Vats A Nayak A Ellis D Randhawa PS Finegold DN Levinson KL Ferrell RE 《Kidney international》2000,57(3):875-881
BACKGROUND: Familial nephrotic syndrome (NS) has both autosomal dominant and recessive forms of inheritance. Recent studies in families with an autosomal dominant form of focal segmental glomerulosclerosis (FSGS) have been at odds concerning linkage to chromosome 19q13 (Mathis et al, Kidney Int 53:282-286, 1998; Winn et al, Kidney Int 55:1241-1246, 1999), suggesting genetic heterogeneity. This study examines the clinical features and confirms linkage to chromosome 19q13 in a family with autosomal dominant NS. METHODS: DNA samples were obtained from 16 of 17 family members. Genomic DNA was isolated, and polymerase chain reaction was performed for five markers spanning the area of interest on chromosome 19q13. Data were evaluated using two- and six-point linkage analysis. RESULTS: Clinical features included presentation of NS in childhood, steroid unresponsiveness, and slow progression to renal failure. Renal biopsy in affected family members showed lesions ranging from minimal change to mesangial proliferative glomerulonephritis to FSGS. Linkage was confirmed between the disease state and chromosome 19q13, with a maximum logarithm of odds (LOD) score of 2.41. Linkage was observed for a 7 cM region on chromosome 19q13, defined by markers D19S425 and D19S220. CONCLUSIONS: This study confirms the Mathis et al report of linkage to chromosome 19q13 in a family with autosomal dominant NS. However, there were notable differences in the presenting clinical and histopathologic features of our affected family members compared with those of Mathis et al. This suggests that the gene on chromosome 19q13 may be responsible for considerable phenotypic heterogeneity and variable expression in both clinical presentation and renal histopathology. 相似文献
24.
Himanshu Nayak Rajendra Gadhavi Bhavin Solanki Bhagyalaxmi Aroor Hemant Gameti Kalpita S Shringarpure Jayun Joshi Zuveriya Kazi 《Bulletin of the World Health Organization》2022,100(8):484
ObjectiveTo implement a community-based screening and awareness-raising project for gestational diabetes in Ahmedabad, India.MethodsThe project took place between April 2016 and August 2019 in Ahmedabad. Medical college faculty members and medical officers trained 3582 paramedical staff on screening for gestational diabetes. These paramedical staff tested all pregnant women 24–28 weeks gestation, who were attending village health and nutrition days – also called mamta days – in urban and rural health centres for routine antenatal care, for gestational diabetes. An oral glucose tolerance test was used and blood sugar ≥ 7.8 mmol/L was the cut-off for gestational diabetes. Women with gestational diabetes were referred for counselling and treatment and all women were followed until 6 weeks after delivery.FindingsOf 53 522 pregnant women screened, 6786 (12.7%) had gestational diabetes and were referred for nutritional therapy or medication; 836 (12.3%) of these women started medication. There was no significant difference in the prevalence of stillbirths between women with gestational diabetes (0.8%; 54/6786) and women without (0.7%; 338/46 736; P-value: 0.51). Of the women on treatment, 38 had abnormal blood glucose after delivery and continued with the medication. Two women with gestational diabetes died; they had other associated co-morbidities – pre-eclampsia and anaemia.ConclusionWe found a high prevalence of gestational diabetes, indicating the need for gestational diabetes screening and implementation of this project on a larger scale. Gestational diabetes screening at the community level is operationally feasible using the existing human resources and infrastructure of the reproductive health programmes. 相似文献
25.
Glaviano A Nayak V Cabuy E Baird DM Yin Z Newson R Ladon D Rubio MA Slijepcevic P Lyng F Mothersill C Case CP 《Oncogene》2006,25(24):3424-3435
There is currently a great interest in delayed chromosomal and other damaging effects of low-dose exposure to a variety of pollutants which appear collectively to act through induction of stress-response pathways related to oxidative stress and ageing. These have been studied mostly in the radiation field but evidence is accumulating that the mechanisms can also be triggered by chemicals, especially heavy metals. Humans are exposed to metals, including chromium (Cr) (VI) and vanadium (V) (V), from the environment, industry and surgical implants. Thus, the impact of low-dose stress responses may be larger than expected from individual toxicity projections. In this study, a short (24 h) exposure of human fibroblasts to low doses of Cr (VI) and V (V) caused both acute chromosome damage and genomic instability in the progeny of exposed cells for at least 30 days after exposure. Acutely, Cr (VI) caused chromatid breaks without aneuploidy while V (V) caused aneuploidy without chromatid breaks. The longer-term genomic instability was similar but depended on hTERT positivity. In telomerase-negative hTERT- cells, Cr (VI) and V (V) caused a long lasting and transmissible induction of dicentric chromosomes, nucleoplasmic bridges, micronuclei and aneuploidy. There was also a long term and transmissible reduction of clonogenic survival, with an increased beta-galactosidase staining and apoptosis. This instability was not present in telomerase-positive hTERT+ cells. In contrast, in hTERT+ cells the metals caused a persistent induction of tetraploidy, which was not noted in hTERT- cells. The growth and survival of both metal-exposed hTERT+ and hTERT- cells differed if they were cultured at subconfluent levels or plated out as colonies. Genomic instability is considered to be a driving force towards cancer. This study suggests that the type of genomic instability in human cells may depend critically on whether they are telomerase-positive or -negative and that their sensitivities to metals could depend on whether they are clustered or diffuse. 相似文献
26.
Prajakta Paritekar Akshay Nayak Y Umesh Indrani Sirivella Sharanya Manoharan Zain Khatib 《Indian journal of ophthalmology》2022,70(4):1203
Purpose:To compare the efficacy of Kane formula with Sanders Retzlaff Kraff/Theoretical (SRK/T) and Barrett Universal II in predicting intraocular lens (IOL) power in Indian eyes.Methods:This retrospective study conducted in a tertiary care eye hospital. Data from patients having uneventful cataract surgery with Tecnis ZCB00 IOL implantation were obtained from Lenstar and electronic medical records. Eyes were divided into subgroups based on axial length (AL) as short (<22.0 mm), medium (22–24 mm), and long (>24 mm). The predicted refractive outcome for each patient was calculated after optimizing the lens constant. Prediction error was calculated by subtracting the predicted spherical equivalent from achieved spherical equivalent 1 week post-surgery. The mean absolute error (MAE) and median absolute error (MedAE) and percentage of eyes within 0.25, 0.5, 1, and 2 D were calculated for each formula. Friedman test, Cochrane Q test were used for statistical analysis.Results:Out of the 350 eyes included in the study, we found that without lens constant optimization, Barrett formula performed better than SRK/T and Kane (P < 0.0001). Over the entire range of axial lengths, Kane formula performed slightly inferior compared to Barrett and SRK-T, both of which performed equally well (P = 0.006). On subgroup analysis, Kane formula performed inferiorly for medium eyes as compared to the other two. No significant differences were noted between the formulae for short and long eyesConclusion:Kane formula did not outperform Barrett Universal II and SRK/T in Indian eyes. 相似文献
27.
28.
29.
30.
Chemical shift encoded techniques have received considerable attention recently because they can reliably separate water and fat in the presence of off‐resonance. The insensitivity to off‐resonance requires that data be acquired at multiple echo times, which increases the scan time as compared to a single echo acquisition. The increased scan time often requires that a compromise be made between the spatial resolution, the volume coverage, and the tolerance to artifacts from subject motion. This work describes a combined parallel imaging and compressed sensing approach for accelerated water–fat separation. In addition, the use of multiscale cubic B‐splines for B0 field map estimation is introduced. The water and fat images and the B0 field map are estimated via an alternating minimization. Coil sensitivity information is derived from a calculated k‐space convolution kernel and l1‐regularization is imposed on the coil‐combined water and fat image estimates. Uniform water–fat separation is demonstrated from retrospectively undersampled data in the liver, brachial plexus, ankle, and knee as well as from a prospectively undersampled acquisition of the knee at 8.6x acceleration. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc. 相似文献