全文获取类型
收费全文 | 3636篇 |
免费 | 198篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 60篇 |
儿科学 | 139篇 |
妇产科学 | 148篇 |
基础医学 | 336篇 |
口腔科学 | 113篇 |
临床医学 | 385篇 |
内科学 | 871篇 |
皮肤病学 | 70篇 |
神经病学 | 290篇 |
特种医学 | 103篇 |
外科学 | 559篇 |
综合类 | 29篇 |
一般理论 | 3篇 |
预防医学 | 326篇 |
眼科学 | 85篇 |
药学 | 179篇 |
中国医学 | 3篇 |
肿瘤学 | 159篇 |
出版年
2023年 | 32篇 |
2022年 | 68篇 |
2021年 | 99篇 |
2020年 | 52篇 |
2019年 | 89篇 |
2018年 | 89篇 |
2017年 | 69篇 |
2016年 | 120篇 |
2015年 | 134篇 |
2014年 | 143篇 |
2013年 | 193篇 |
2012年 | 284篇 |
2011年 | 278篇 |
2010年 | 157篇 |
2009年 | 154篇 |
2008年 | 266篇 |
2007年 | 274篇 |
2006年 | 249篇 |
2005年 | 240篇 |
2004年 | 238篇 |
2003年 | 161篇 |
2002年 | 170篇 |
2001年 | 58篇 |
2000年 | 43篇 |
1999年 | 31篇 |
1998年 | 15篇 |
1997年 | 12篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 4篇 |
1992年 | 10篇 |
1991年 | 15篇 |
1990年 | 9篇 |
1989年 | 7篇 |
1988年 | 6篇 |
1987年 | 9篇 |
1986年 | 8篇 |
1985年 | 5篇 |
1983年 | 7篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1971年 | 11篇 |
1969年 | 5篇 |
1968年 | 2篇 |
排序方式: 共有3858条查询结果,搜索用时 15 毫秒
1.
2.
3.
Blouquit S Sari A Lombet A D'herbomez M Naline E Matran R Chinet T 《American journal of respiratory cell and molecular biology》2003,29(2):245-251
Endothelin-1 (ET-1) exerts many biological effects in airways, including bronchoconstriction, airway mucus secretion, cell proliferation, and inflammation. We investigated the effect of ET-1 on Na absorption and Cl secretion in human bronchial epithelial cells. Addition of 10(-7) M ET-1 had no effect on the inhibition of the short circuit current (Isc) induced by amiloride, a Na channel blocker. Addition of 10(-7) M ET-1 to the apical bath in the presence of amiloride increased Isc in cultured human bronchial epithelial cells studied in Ussing chambers. No effect was observed when ET-1 was added to basolateral bath, indicating that the involved ET-1 receptors are likely present only in the apical membrane of the cells. Use of Cl-free solutions and bumetanide reduced the ET-1-induced increases in Isc, indicating that ET-1 stimulates Cl secretion. The ET-1-induced increase in Isc was prevented by exposure to the ETB receptor antagonist BQ-788 but not to the ETA receptor antagonist BQ-123. ET-1 did not raise intracellular Ca levels, but increased the intracellular concentration of cAMP. These findings indicate that ET-1 is a Cl secretagogue in human airways and acts presumably through apically located ETB receptors and activation of the cAMP pathway. 相似文献
4.
Synthetic env gp41 peptide as a sensitive and specific diagnostic reagent in different stages of human immunodeficiency virus type 1 infection 总被引:10,自引:0,他引:10
Ale Nrvnen Mirja Korkolainen Jukka Suni Jukka Korpela Sari Kontio Paul Partanen Antti Vaheri Marja-Liisa Huhtala 《Journal of medical virology》1988,26(2):111-118
An enzyme immunoassay (EIA) for serum antibodies to human immunodeficiency virus type 1 (HIV-1), based on the synthetic pentadecapeptide SGKLICT-TAVPWNAS, a segment of the transmembrane glycoprotein (gp41) of the virus, was developed and tested for sensitivity and specificity. Sera of 152 individuals at various stages of HIV-1 infection, including two prospectively and six retrospectively studied patients exposed to HIV-1 but seronegative on initial testing in whole-virus EIA and immunoblotting, were screened with the gp41 peptide antibody EIA. The reference population consisted of 1,000 healthy HIV-1 antibody-negative blood donors. In addition, five individuals with antibodies to HIV-2 were studied. Antibodies to the synthetic peptide were detected in 100% of those with asymptomatic infection. Only one patient with LAS failed to react in the peptide EIA. Patients with HIV-2 infection did not react in this test. The peptide antibodies appeared rapidly after infection, were detectable at the time when seroconversion was observed by immunoblotting, and preceded reactivity in whole-virus EIA. Sera of seven patients with verified HIV-1 infection did not react with gp41 in immunoblotting, although antibodies were readily detectable in the gp41 peptide EIA. 相似文献
5.
Tiina Paunio Yoshihide Sunada Sari Kiuru Hideo Makishita Shu-Ichi Ikeda Jean Weissenbach Jorma Palo Leena Peltonen 《Human mutation》1995,6(1):60-65
Familial amyloidosis, Finnish type (FAF) (gelsolin-related amyloidosis) is an autosomal dominant form of systemic amyloidosis characterized by corneal lattice dystrophy and peripheral polyneuropathy. The accumulating protein in FAF consists of fragments of gelsolin, an actin-modulating protein. The gelsolin mutation G654A has been found in both Finnish and Japanese patients. To study the origin of the gelsolin mutation in these patients we performed haplotype analysis in 10 Finnish and 2 Japanese FAF families. Poymorphic DNA markers GSN, D9S103, AFMa061xd9, and AFMa139xb9 revealed a uniform disease haplotype in all the disease-associated chromosomes of the Finnish FAF families, which was different from the one observed in the Japanese families. The present results and the previously detected gelsolin mutation G654T in Czech and Danish FAF patients suggest that nucle otide 654 may represent a mutation hot spot in the gelsolin gene. The DNA markers studied here will be useful in future genealogical analyses of FAF. © 1995 Wiley-Liss, Inc. 相似文献
6.
Coding haplotype analysis supports HCR as the putative susceptibility gene for psoriasis at the MHC PSORS1 locus 总被引:13,自引:0,他引:13
Asumalahti K Veal C Laitinen T Suomela S Allen M Elomaa O Moser M de Cid R Ripatti S Vorechovsky I Marcusson JA Nakagawa H Lazaro C Estivill X Capon F Novelli G Saarialho-Kere U Barker J Trembath R Kere J;Psoriasis Consortium 《Human molecular genetics》2002,11(5):589-597
PSORS1, near HLA-C, is the major genetic determinant of psoriasis. We present genetic and structural evidence suggesting a major role for the HCR gene at the PSORS1 locus. Genotyping of 419 families from six populations revealed that coding single-nucleotide polymorphisms of HCR formed a conserved allele HCR*WWCC that associated highly significantly with psoriasis and with the HLA-Cw6 allele in all populations. Because of strong linkage disequilibrium between HLA-Cw6 and HCR*WWCC, the two genes could not be genetically distinguished by this sample size. However, the variant HCR allele was predicted to differ in secondary structure from the wild-type protein. HCR protein expression in lesional psoriatic skin differed considerably from that observed in normal skin. These results provide strong evidence for the HCR*WWCC allele as a major genetic determinant for psoriasis, probably by a mechanism impacting on keratinocyte proliferation. 相似文献
7.
Upper and lower gastrointestinal endoscopical investigation in elderly patients with iron deficiency anaemia 总被引:1,自引:0,他引:1
Iron deficiency anaemia is frequently observed in male adults and postmenopausal women due to chronic occult bleeding, usually from the gastrointestinal tract. Practically, as endoscopical investigation of the gastrointestinal system is an invasive procedure, iron replacement treatment was generally started without investigation of the underlying aetiology even in first-line health institutions. This study evaluates the role of endoscopy in the investigation of the aetiology of anaemia in 95 patients (51 males, 44 females), aged 64.9+/-12.5 years (range 50-90 years). All patients having iron deficiency anaemia were investigated by upper gastrointestinal endoscopy and colonoscopy. Upper and lower gastrointestinal pathologies were seen in 10 (10.6%) and 55 (57.8%) patients, respectively. However, no gastrointestinal lesion was found in 30 (31.6%) patients with iron deficiency anaemia. Out of the 95 patients, 16 (16.9%) had erosive gastritis, 15 (15.8%) duodenal ulcer, 8 (8.4%) gastric ulcer, 7 (7.3%) gastric tumours, 7 (7.3%) oesophagitis. 5 (5.4%) colon tumours, 3 (3.2%) haemorrhoids, 2 (2.1%) non-tropical sprue, 1 (1%) colonic polyp, and 1 (1%) colitis. In the majority of elderly patients with iron deficiency anaemia, upper gastrointestinal system disease was found. In 12 (12.7%) patients in the study group, malignancies were detected. In elderly patients with iron deficiency anaemia, the aetiology should be highlighted before giving iron supplementation. 相似文献
8.
Elena R. Schiff Malena Daich Varela Anthony G. Robson Karen Pierpoint Rola Ba‐Abbad Savita Nutan Wadih M. Zein Ehsan Ullah Laryssa A. Huryn Sari Tuupanen Omar A. Mahroo Michel Michaelides Derek Burke Katie Harvey Gavin Arno Robert B. Hufnagel Andrew R. Webster 《American journal of medical genetics. Part C, Seminars in medical genetics》2020,184(3):631-643
Pathogenic variants in the gene HGSNAT (heparan‐α‐glucosaminide N‐acetyltransferase) have been reported to underlie two distinct recessive conditions, depending on the specific genotype, mucopolysaccharidosis type IIIC (MPSIIIC)—a severe childhood‐onset lysosomal storage disorder, and adult‐onset nonsyndromic retinitis pigmentosa (RP). Here we describe the largest cohort to‐date of HGSNAT‐associated nonsyndromic RP patients, and describe their retinal phenotype, leukocyte enzymatic activity, and likely pathogenic genotypes. We identified biallelic HGSNAT variants in 17 individuals (15 families) as the likely cause of their RP. None showed any other symptoms of MPSIIIC. All had a mild but significant reduction of HGSNAT enzyme activity in leukocytes. The retinal condition was generally of late‐onset, showing progressive degeneration of a concentric area of paramacular retina, with preservation but reduced electroretinogram responses. Symptoms, electrophysiology, and imaging suggest the rod photoreceptor to be the cell initially compromised. HGSNAT enzymatic testing was useful in resolving diagnostic dilemmas in compatible patients. We identified seven novel sequence variants [p.(Arg239Cys); p.(Ser296Leu); p.(Phe428Cys); p.(Gly248Ala); p.(Gly418Arg), c.1543‐2A>C; c.1708delA], three of which were considered to be retina‐disease‐specific alleles. The most prevalent retina‐disease‐specific allele p.(Ala615Thr) was observed heterozygously or homozygously in 8 and 5 individuals respectively (7 and 4 families). Two siblings in one family, while identical for the HGSNAT locus, but discordant for retinal disease, suggest the influence of trans‐acting genetic or environmental modifying factors. 相似文献
9.
Siltanen Sini Ilmarinen Katja Luoma Minna-Liisa Leppäaho Suvi Kehusmaa Sari 《Quality of life research》2022,31(11):3177-3187
Quality of Life Research - We investigated how quality of life (QoL) changed between 2018 and 2020, and how its related factors, i.e., communication with friends and family, loneliness, and... 相似文献
10.
Markus Mattila Leena Hakola Sari Niinist Heli Tapanainen Hanna-Mari Takkinen Suvi Ahonen Jorma Ilonen Jorma Toppari Riitta Veijola Mikael Knip Suvi M. Virtanen 《Nutrients》2021,13(3)
Our aim was to study the associations between maternal vitamin C and iron intake during pregnancy and the offspring’s risk of developing islet autoimmunity and type 1 diabetes. The study was a part of the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) prospective birth cohort including children genetically at risk of type 1 diabetes born between 1997–2004. The diets of 4879 mothers in late pregnancy were assessed with a validated food frequency questionnaire. The outcomes were islet autoimmunity and type 1 diabetes. Cox proportional hazards regression analysis adjusted for energy, family history of diabetes, human leukocyte antigen (HLA) genotype and sex was used for statistical analyses. Total intake of vitamin C or iron from food and supplements was not associated with the risk of islet autoimmunity (vitamin C: HR 0.91: 95% CI (0.80, 1.03), iron: 0.98 (0.87, 1.10)) or type 1 diabetes (vitamin C: 1.01 (0.87, 1.17), iron: 0.92 (0.78, 1.08)), neither was the use of vitamin C or iron supplements associated with the outcomes. In conclusion, no association was found between maternal vitamin C or iron intake during pregnancy and the risk of islet autoimmunity or type 1 diabetes in the offspring. 相似文献