全文获取类型
收费全文 | 1295篇 |
免费 | 92篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 40篇 |
儿科学 | 42篇 |
妇产科学 | 35篇 |
基础医学 | 174篇 |
口腔科学 | 28篇 |
临床医学 | 77篇 |
内科学 | 300篇 |
皮肤病学 | 21篇 |
神经病学 | 128篇 |
特种医学 | 44篇 |
外科学 | 170篇 |
综合类 | 14篇 |
预防医学 | 37篇 |
眼科学 | 9篇 |
药学 | 68篇 |
肿瘤学 | 207篇 |
出版年
2023年 | 4篇 |
2022年 | 13篇 |
2021年 | 15篇 |
2020年 | 18篇 |
2019年 | 28篇 |
2018年 | 21篇 |
2017年 | 14篇 |
2016年 | 39篇 |
2015年 | 22篇 |
2014年 | 48篇 |
2013年 | 65篇 |
2012年 | 74篇 |
2011年 | 67篇 |
2010年 | 46篇 |
2009年 | 55篇 |
2008年 | 62篇 |
2007年 | 86篇 |
2006年 | 66篇 |
2005年 | 82篇 |
2004年 | 69篇 |
2003年 | 62篇 |
2002年 | 82篇 |
2001年 | 20篇 |
2000年 | 15篇 |
1999年 | 22篇 |
1998年 | 35篇 |
1997年 | 31篇 |
1996年 | 21篇 |
1995年 | 22篇 |
1994年 | 18篇 |
1993年 | 16篇 |
1992年 | 15篇 |
1991年 | 13篇 |
1990年 | 6篇 |
1989年 | 8篇 |
1988年 | 14篇 |
1987年 | 10篇 |
1986年 | 8篇 |
1985年 | 10篇 |
1984年 | 14篇 |
1983年 | 9篇 |
1982年 | 11篇 |
1981年 | 11篇 |
1980年 | 9篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1964年 | 2篇 |
排序方式: 共有1394条查询结果,搜索用时 29 毫秒
31.
Doron Steinberg Lana Eskander Avraham Zini Harold Sgan-Cohen Musa Bajali 《Clinical oral investigations》2014,18(3):979-983
Objectives
The aim of the present study was to investigate the distribution of oral cariogenic bacteria among 12-year-old Palestinian children attending schools in East Jerusalem.Materials and methods
Salivary levels of mutans streptococci (MS) and Lactobacilli (LB) were examined by semi-quantitative commercial kits and then correlated to social–demographic parameters.Results
Overall, 52.1 % of the examined children presented the highest possible ranking score categories for MS bacteria, with only 5.4 % in the lowest category. Only 12.6 % of the school children presented the highest LB score, while 25 % had the lowest ranking score. Salivary MS levels in children attending private schools were lower than those of children in government schools and United Nations Relief and Works Agency (UNRWA) schools. Conversely, levels of LB were lowest in children attending UNRWA schools compared to government and private schools. Girls had significantly higher amounts of MS and LB than boys (p?=?0.001). Lower MS levels were significantly related to the following socioeconomic variables: higher father’s education level (p?=?0.037), higher mother’s education level (p?=?0.063), mother’s employment status (p?=?0.012), and lower home density (p?=?0.001). For LB, the only significant socioeconomic variable was higher father’s employment level, which was related to lower LB level (p?=?0.025).Conclusions
Levels of MS and LB were found to be strongly related with socioeconomic status among Palestinian children in East Jerusalem. The relatively high prevalence of cariogenic bacteria suggests that oral care prevention and treatment demands special attention from the health care institutions and authorities. 相似文献32.
33.
Aganna E Zeharia A Hitman GA Basel-Vanagaite L Allotey RA Booth DR Hawkins PN Thacker C Syndercombe-Court D McDermott MF 《Arthritis and rheumatism》2002,46(1):245-249
OBJECTIVE: To investigate genetic susceptibility to recurrent fevers, generalized severe myalgia, and migratory erythema in an Israeli Arab child with no family history of similar disease. METHODS: DNA sequencing of exons 1-6 of the TNFRSF1A gene (formerly TNFR1) was performed in the patient and his parents to determine the presence of the autosomal-dominant tumor necrosis factor receptor-associated periodic syndrome (TRAPS); informative markers spanning the TNFRSF1A locus were used to genotype all available members of the patient's family. The TNFRSF1A gene was subsequently screened in 69 healthy Arab controls and 96 Caucasian controls. Formal forensic paternity testing was performed on the child. RESULTS: We found a de novo missense mutation in exon 3 of the TNFRSF1A gene, involving a novel C-->T transition encoding a Cys70Arg (C70R) variant, in the Israeli Arab patient. Eight of the common familial Mediterranean fever (FMF) gene MEFV mutations were excluded. This mutation was not present in the parents or siblings, or among the 69 healthy Arab controls. However, another TNFRSF1A variant, Pro46Lys (P46L), was present in 1 of the Arab controls. CONCLUSION: We have identified a TNFRSF1A mutation associated with periodic fever in an Arab patient, and a TNFRSF1A variant, which is variably pathogenic in Caucasians, in an Arab control. This is the first report of a de novo mutation in periodic fevers in general, and also of TRAPS in the Arab population. These findings demonstrate the need to include TRAPS in the differential diagnosis of recurrent fevers in this population. 相似文献
34.
Kipnis J Mizrahi T Yoles E Ben-Nun A Schwartz M Ben-Nur A 《Journal of neuroimmunology》2002,126(1-2):78-85
This study examined the expression of constitutive endothelial nitric oxide synthase (eNOS) and inducible NOS (iNOS) in the sciatic nerve of Lewis rats with experimental autoimmune neuritis (EAN). Western blot analysis showed that both eNOS and iNOS expressions in the sciatic nerves of rats increased significantly during the peak stage of EAN, but declined thereafter. Only minimal amounts of these enzymes were identified in normal rat sciatic nerves. Immunohistochemical studies showed that eNOS was increased in vascular endothelial cells and Schwann cells, but not in inflammatory cells, during the peak stage of EAN. However, iNOS was found mainly in inflammatory macrophages in sciatic nerve EAN lesions.These findings suggest that, depending on the stage of peripheral nervous system autoimmune disease, the increased expressions of both eNOS and iNOS might be involved in either the production of detrimental effects during the induction stage of EAN or in the recovery from EAN paralysis. 相似文献
35.
Volokhov D Pomerantsev A Kivovich V Rasooly A Chizhikov V 《Diagnostic microbiology and infectious disease》2004,49(3):163-171
We have developed a rapid assay based on microarray analysis of amplified genetic markers for reliable identification of Bacillus anthracis and its discrimination from other closely related bacterial species of the Bacillus cereus group. By combining polymerase chain reaction (PCR) amplification of six B. anthracis-specific genes (plasmid-associated genes encoding virulence factors (cyaA, pagA, lef, and capA, capB, capC) and one chromosomal marker BA-5449) with analysis of amplicons by microarray hybridization, we were able to unambiguously identify and discriminate B. anthracis among other closely related species. Bacillus identification relied on hybridization with multiple individual microarray oligonucleotide probes (oligoprobes) specific to each target B. anthracis gene. Evaluation of the assay was conducted using several B. anthracis strains (with or without pXO1 and pXO2 plasmids) as well as over 50 other species phylogenetically related to B. anthracis, including B. cereus, B. thuringiensis, B. mycoides, and B. subtilis. The developed microarray analysis of amplified genetic markers protocol provides an efficient method for (i) unambiguous identification and discrimination of B. anthracis from other Bacillus species and (ii) distinguishing between plasmid-containing and plasmid-free Bacillus anthracis strains. 相似文献
36.
Keating MJ; Kantarjian H; Talpaz M; Redman J; Koller C; Barlogie B; Velasquez W; Plunkett W; Freireich EJ; McCredie KB 《Blood》1989,74(1):19-25
Fludarabine was used to treat 68 patients with previously treated chronic lymphocytic leukemia (CLL). Nine (13%) patients achieved a complete remission and 30 (44%) a partial remission. The response rates for Rai stages 0 to 2, 3, and 4 were 64%, 58%, and 50% respectively. Seventeen (43%) of the 40 Rai stage 1 to 3 patients and four (19%) of the Rai stage 4 patients returned to Rai stage 0. Survival was strongly correlated with the final Rai stage achieved. The survival of the 11 partial responders with residual disease consisting only of residual bone-marrow nodules was similar to the complete responders (36+ months) and superior to the other partial response patients (16 months). The response to fludarabine was rapid, with 36 (92%) of the 39 responders having achieved at least a partial response following the first three courses. Complete responses occurred in the blood, liver, spleen, and lymph nodes in 48% to 69% of the patients. Eradication of all disease in the bone marrow occurred in only 13% of the cases. Neutropenia and thrombocytopenia occurred in 56% and 25% of evaluable courses. Major infections occurred in 9% of evaluable courses and fevers of unknown origin or minor infections in 12% of courses respectively. Myelosuppression and infection were more common in patients with initial Rai stages 3 and 4 and in nonresponding patients. Other toxicity was mild. No CNS toxicity was noted. 相似文献
37.
Brownstein Z Ben-Yosef T Dagan O Frydman M Abeliovich D Sagi M Abraham FA Taitelbaum-Swead R Shohat M Hildesheimer M Friedman TB Avraham KB 《Pediatric research》2004,55(6):995-1000
Usher syndrome is a frequent cause of the combination of deafness and blindness due to retinitis pigmentosa (RP). Five genes are known to underlie different forms of Usher syndrome type I (USH1). In the Ashkenazi Jewish population, the R245X mutation of the PCDH15 gene may be the most common cause of USH1 (Ben-Yosef T, Ness SL, Madeo AC, Bar-Lev A, Wolfman JH, Ahmed ZM, Desnick RK, Willner JP, Avraham KB, Ostrer H, Oddoux C, Griffith AJ, Friedman TB N Engl J Med 348: 1664-1670, 2003). To estimate what percentage of Ashkenazi Jewish children born with profound hearing loss will develop RP due to R245X, we examined the prevalence of the R245X PCDH15 mutation and its carrier rate among Ashkenazi Jews in Israel. Among probands diagnosed with nonsyndromic hearing loss not due to mutations of connexin 26 (GJB2) and/or connexin 30 (GJB6), and below the age of 10, 2 of 20 (10%) were homozygous for the R245X mutation. Among older nonsyndromic deaf individuals, no homozygotes were detected, although one individual was heterozygous for R245X. The carrier rate of the R245X mutation among the normal hearing Ashkenazi population in Israel was estimated at 1%. Ashkenazi Jewish children with profound prelingual hearing loss should be evaluated for the R245X PCDH15 mutation and undergo ophthalmologic evaluation to determine whether they will develop RP. Rehabilitation can then begin before loss of vision. Early use of cochlear implants in such cases may rescue these individuals from a dual neurosensory deficit. 相似文献
38.
Emilie Croisier Linda B Moran David T Dexter Ronald KB Pearce Manuel B Graeber 《Journal of neuroinflammation》2005,2(1):14
Background
The role of both microglial activation and alpha-synuclein deposition in Parkinson's disease remain unclear. We have tested the hypothesis that if microglia play a primary role in Parkinson's disease pathogenesis, the microglial "activated" phenotype should be associated with histopathological and/or clinical features of the disease. 相似文献39.
Eldar-Geva T Margalioth EJ Gal M Ben-Chetrit A Algur N Zylber-Haran E Brooks B Huerta M Spitz IM 《Human reproduction (Oxford, England)》2005,20(7):1814-1819
BACKGROUND: Anti-Mullerian hormone (AMH) is expressed in pre- and small-antral follicles. High serum levels are found in women with polycystic ovaries (PCO), accordant with their increased content of small follicles. To evaluate the relationship between AMH, folliculogenesis and hyperandrogenism, we compared serum AMH levels between women with PCO with and without hyperandrogenism and normal controls during controlled ovarian hyperstimulation (COH). METHODS: Nineteen women with PCO and hyperandrogenism (group A), 10 women with PCO but no hyperandrogenism (group B) and 23 ovulatory women with normal ovarian morphology (group C, controls) underwent COH with the long protocol. Serum levels of AMH, estradiol, androstenedione and follicular tracking were determined before gonadotropins treatment (day 0) and every 2-4 days up to the day of HCG administration. RESULTS: AMH levels declined gradually throughout COH in the three groups, but remained higher in groups A and B compared with the controls. Significantly higher levels were found in group A compared with group B, despite comparable numbers of small follicles. Multiple regression analysis revealed that both the number of small follicles and serum androgens were correlated to AMH. CONCLUSIONS: Women with PCO have higher serum AMH levels during COH than controls. Hyperandrogenism is associated with an additional increase in AMH. It is conceivable that hyperandrogenism may reflect more severe disruption of folliculogenesis in women with PCO or may affect AMH secretion. 相似文献
40.
Proteases, extracellular matrix, and cancer: a workshop of the path B study section 总被引:1,自引:0,他引:1 下载免费PDF全文
DeClerck YA Mercurio AM Stack MS Chapman HA Zutter MM Muschel RJ Raz A Matrisian LM Sloane BF Noel A Hendrix MJ Coussens L Padarathsingh M 《The American journal of pathology》2004,164(4):1131-1139
The role of the extracellular matrix (ECM) in the tumor microenvironment is not limited to being a barrier against tumor invasion. The ECM is a reservoir of cell binding proteins and growth factors that affect tumor cell behavior. It is also substantially modified by proteases produced by tumor cells or stroma cells. As a result of the activity of these proteases, cell-cell and cell-ECM interactions are altered, new biologically active ECM molecules are generated, and the bioavailability and activity of many growth factors, growth factor receptors, and cytokines are modified. ECM-degrading proteases also play a critical role in angiogenesis, where they can act as positive as well as negative regulators of endothelial cell proliferation and vascular morphogenesis. This review article summarizes some of the most relevant findings made over the recent years that were discussed at a workshop organized by the Path B Study Section of the National Institutes of Health in October 2002. 相似文献