全文获取类型
收费全文 | 6220篇 |
免费 | 359篇 |
国内免费 | 43篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 192篇 |
妇产科学 | 282篇 |
基础医学 | 800篇 |
口腔科学 | 153篇 |
临床医学 | 474篇 |
内科学 | 1580篇 |
皮肤病学 | 205篇 |
神经病学 | 471篇 |
特种医学 | 371篇 |
外科学 | 837篇 |
综合类 | 33篇 |
一般理论 | 1篇 |
预防医学 | 228篇 |
眼科学 | 36篇 |
药学 | 493篇 |
2篇 | |
中国医学 | 7篇 |
肿瘤学 | 431篇 |
出版年
2023年 | 29篇 |
2022年 | 46篇 |
2021年 | 83篇 |
2020年 | 72篇 |
2019年 | 104篇 |
2018年 | 119篇 |
2017年 | 87篇 |
2016年 | 98篇 |
2015年 | 93篇 |
2014年 | 142篇 |
2013年 | 193篇 |
2012年 | 316篇 |
2011年 | 236篇 |
2010年 | 142篇 |
2009年 | 169篇 |
2008年 | 280篇 |
2007年 | 290篇 |
2006年 | 260篇 |
2005年 | 249篇 |
2004年 | 282篇 |
2003年 | 223篇 |
2002年 | 224篇 |
2001年 | 187篇 |
2000年 | 254篇 |
1999年 | 214篇 |
1998年 | 94篇 |
1997年 | 78篇 |
1996年 | 105篇 |
1995年 | 83篇 |
1994年 | 66篇 |
1993年 | 72篇 |
1992年 | 154篇 |
1991年 | 166篇 |
1990年 | 143篇 |
1989年 | 151篇 |
1988年 | 127篇 |
1987年 | 112篇 |
1986年 | 96篇 |
1985年 | 112篇 |
1984年 | 77篇 |
1983年 | 74篇 |
1982年 | 32篇 |
1981年 | 40篇 |
1979年 | 45篇 |
1978年 | 28篇 |
1977年 | 37篇 |
1976年 | 33篇 |
1975年 | 39篇 |
1974年 | 30篇 |
1973年 | 27篇 |
排序方式: 共有6622条查询结果,搜索用时 15 毫秒
71.
E. Fermo P. Bianchi W. Barcellini P. Pedotti C. Boschetti F. Alfinito A. Cortelezzi A. Zanella 《International journal of immunogenetics》2004,31(6):267-269
We investigated regulatory variants of five cytokine genes [tumour necrosis factor (TNF)‐α, interferon (IFN)‐γ, transforming growth factor (TGF)‐β, interleukin (IL)‐6 and IL‐10] in 40 Italian patients affected by paroxysmal nocturnal haemoglobinuria (PNH) and aplastic anaemia (AA). Genotypes associated with high production of TGF‐β and IFN‐γ were more frequent in patients than in controls. Genetic regulation of the immunological pathways involved in the pathogenesis of bone marrow failure is suggested. 相似文献
72.
Anna Siniscalchi Irene Badini Antonio Cintra Kjell Fuxe Clementina Bianchi Lorenzo Beani 《Neuroscience letters》1992,140(2):235-238
Spontaneous and electrically evoked endogenous acetylcholine release and [3H]-choline efflux from slices of guinea pig nucleus basalis magnocellularis (nbM) were studied. Tetrodotoxin reduced the spontaneous endogenous release by 55%, while the Ca2+-free medium reduced it by about 30%. Evoked [3H]-choline efflux was Na+ and Ca2+ dependent and frequency related. Physostigmine, 30 μM, nearly halved the stimulation-evoked efflux; atropine, 0.15 μM, not only antagonized, but even reversed this effect into facilitation. Pirenzepine, 1 μM, and AFDX 116, 1 μM, were less effective than atropine, and reversed the inhibitory effect of physostigmine only when applied together. 4-DAMP, 0.01 μM, was ineffective. These findings indicate that acetylcholine release in guinea pig nbM slices is inhibited by the cooperation of muscarinic autoreceptors, possibly belonging to the M1 and M2 subclasses. 相似文献
73.
C. Scieux A. Bianchi S. Henry N. Brunat S. Abdennader D. Vexiau M. Janier P. Morel P. H. Lagrange 《European journal of clinical microbiology & infectious diseases》1992,11(8):704-708
A chemiluminometric immunoassay (Magic Lite Chlamydia) for detection ofChlamydia trachomatis antigens in first-void urine samples was compared with cell culture using urogenital swabs from 221 men and 242 women. The rate of isolation ofChlamydia trachomatis was 23.5 % in men, nearly 80 % of whom had symptoms of urethritis, and 8.3 % in women, in whom both cervix and urethra samples were tested. In urine sediments from men and women respectively the chemiluminometric assay showed a sensitivity of 80.8 % and 70 %, a specificity of 97 % and 95 %, a positive predictive value of 89.4 % and 58.3 %, and a negative predictive value of 94.3 % and 97.2 %. Discrepancies between results obtained with the chemiluminometric assay and cell culture were resolved using two polymerase chain reaction techniques to test urogenital samples. The detection ofChlamydia trachomatis in urine samples with the chemiluminometric assay was confirmed to be superior for screening symptomatic men with urogenital infections than women as a lower prevalence population. 相似文献
74.
Matthias G. Pauthner Joseph P. Nkolola Colin Havenar-Daughton Ben Murrell Samantha M. Reiss Raiza Bastidas Jérémie Prévost Rebecca Nedellec Benjamin von Bredow Peter Abbink Christopher A. Cottrell Daniel W. Kulp Talar Tokatlian Bartek Nogal Matteo Bianchi Hui Li Jeong Hyun Lee Salvatore T. Butera Dennis R. Burton 《Immunity》2019,50(1):241-252.e6
75.
Esterase activity studies on the areas of lymphoid infiltration in the bursa of Fabricius (diffusely infiltrated area) and the dorsal wall of the cloaca showed that the epithelial cells exhibit varying degrees of diffuse esterase activity; it was possible to demonstrate the presence of spot-like esterase positivity in star-shaped cells in the epithelium itself. These cells can be found at various levels from the proximal to the distal region and have also been observed in the connective tissue of the tunica propria; as a result, the hypothesis has been advanced that they are connective tissue. 相似文献
76.
Riccardo Schiavina Matteo Droghetti Giacomo Novara Lorenzo Bianchi Caterina Gaudiano Valeria Panebianco Marco Borghesi Pietro Piazza Federico Mineo Bianchi Marco Guerra Beniamino Corcioni Michelangelo Fiorentino Francesca Giunchi Paolo Verze Cristian Pultrone Rita Golfieri Angelo Porreca Vincenzo Mirone Eugenio Brunocilla 《Urologic oncology》2021,39(7):433.e1-433.e7
BackgroundWe aim to evaluate the impact of multiparametric magnetic resonance imaging and fusion-target biopsy for early reclassification of patients with low-risk Prostate Cancer in a randomized trial.Materials and methodsBetween 2015 and 2018, patients diagnosed with Prostate Cancer after random biopsy fulfilling PRIAS criteria were enrolled and centrally randomized (1:1 ratio) to study group or control group. Patients randomized to study group underwent multiparametric magnetic resonance imaging at 3 months from enrollment: patients with positive findings (PIRADS-v2>2) underwent fusion-target biopsy; patients with negative multiparametric magnetic resonance imaging or confirmed ISUP - Grade Group 1 at fusion-target biopsy were managed according to PRIAS schedule and 12-core random biopsy was performed at 12 months. Patients in control group underwent PRIAS protocol, including a confirmatory 12-core random biopsy at 12 months. Primary endpoint was a reduction of reclassification rate at 12-month random biopsy in study group at least 20% less than controls. Reclassification was defined as biopsy ISUP Grade Group 1 in >2 biopsy cores or disease upgrading.ResultsA total of 124 patients were randomized to study group (n = 62) or control group (n = 62). Around 21 of 62 patients (34%) in study group had a positive multiparametric magnetic resonance imaging, and underwent fusion-target biopsy, with 11 (17.7%) reclassifications. Considering the intention-to-treat population, reclassification rate at 12-month random biopsy was 6.5% for study group and 29% for control group, respectively (P < 0.001).ConclusionsThe early employment of multiparametric magnetic resonance imaging for active surveillance patients enrolled after random biopsy consents to significantly reduce reclassifications at 12-month random biopsy. 相似文献
77.
Requirement of HMGB1 and RAGE for the maturation of human plasmacytoid dendritic cells 总被引:8,自引:0,他引:8
Dumitriu IE Baruah P Bianchi ME Manfredi AA Rovere-Querini P 《European journal of immunology》2005,35(7):2184-2190
Dendritic cells (DC) are key components of innate and adaptive immune responses. Plasmacytoid DC (PDC) are a specialized DC subset that produce high amounts of type I interferons in response to microbes. High mobility group box 1 protein (HMGB1) is an abundant nuclear protein, which acts as a potent pro-inflammatory factor when released extracellularly. We show that HMGB1 leaves the nucleus of maturing PDC following TLR9 activation, and that PDC express on the plasma membrane the best-characterized receptor for HMGB1, RAGE. Maturation and type I IFN secretion of PDC is hindered when the HMGB1/RAGE pathway is disrupted. These results reveal HMGB1 and RAGE as the first known autocrine loop modulating the maturation of PDC, and suggest that antagonists of HMGB1/RAGE might have therapeutic potential for the treatment of systemic human diseases. 相似文献
78.
Ambroxol inhibits interleukin 1 and tumor necrosis factor production in human mononuclear cells 总被引:1,自引:0,他引:1
M. Bianchi A. Mantovani A. Erroi C. A. Dinarello P. Ghezzi 《Inflammation research》1990,31(3-4):275-279
We have studied the effect of Ambroxol on the production of Interleukin-1 (IL-1) and Tumor Necrosis Factor (TNF) in human mononuclear cells (MNC). For this purpose MNC were cultured for 24 h in the presence of endotoxin and different doses of Ambroxol. The results indicate that Ambroxol markedly inhibited IL-1 and TNF production at doses of 10–100 g/ml, without any apparent toxicity. 相似文献
79.
80.
Angela Bachi Raffaella Brambilla Roberto Fanelli Roberto Bianchi Ettore Zuccato Chiara Chiabrando 《British journal of pharmacology》1997,121(8):1770-1774
- 8-epi-prostaglandin (PG) F2α, a major F2 isoprostane, is produced in vivo by free radical-dependent peroxidation of lipid-esterified arachidonic acid. Both cyclo-oxygenase isoforms (COX-1 and COX-2) may also form free 8-epi-PGF2α as a minor product. It has been recently seen in human volunteers that the overall basal formation of 8-epi-PGF2α in vivo is mostly COX-independent and urinary 8-epi-PGF2α is therefore an accurate marker of ‘basal'' oxidative stress in vivo.
- To test the validity of this marker in the rat, we evaluated in vivo the effect of COX inhibition on the formation of 8-epi-PGF2α vs prostanoids. Two structurally unrelated COX inhibitors (naproxen: 30 mg kg−1 day−1; indomethacin: 4 mg kg−1 day−1) were given i.p. to rats kept in metabolic cages. In vivo formation of 8-epi-PGF2α was assessed by measuring its urinary excretion. Prostanoid biosynthesis was assessed by measuring urinary excretion of major metabolites of thromboxane (TX) and prostacyclin (2,3-dinor-TXB1 and 2,3-dinor-6-keto-PGF1α). All compounds were selectively measured by immunopurification/gas chromatography-mass spectrometry.
- Naproxen reduced urinary excretion of 2,3-dinor-TXB1 and 2,3-dinor-6-keto-PGF1α but, unexpectedly, also that of 8-epi-PGF2α (82, 49 and 52% inhibition, respectively). Indomethacin had a similar effect (77, 69 and 55% inhibition). Esterified 8-epi-PGF2α in liver and plasma remained unchanged after indomethacin.
- These findings prompted us to re-assess the contribution of COX activity to the systemic production of 8-epi-PGF2α in man. We gave naproxen (1 g day−1) to healthy subjects (four nonsmokers and four smokers). Urinary 8-epi-PGF2α remained unchanged in the two groups (9.63±0.99 before vs 10.24±1.01 after and 20.14±3.00 vs 19.03±2.45 ng h−1 1.73 m−2), whereas there was a marked reduction of major urinary metabolites of thromboxane and prostacyclin (about 90% for both 11-dehydro-TXB2 and 2,3-dinor-TXB2; >50% for 2,3-dinor-6-keto-PGF1α).
- To investigate whether rat COX-1 produces 8-epi-PGF2α more efficiently than human COX-1, we measured the ex vivo formation of 8-epi-PGF2α and TXB2 simultaneously in whole clotting blood. Serum levels of 8-epi-PGF2α and TXB2 were similar in rats and man.
- We conclude that a significant amount of COX-dependent 8-epi-PGF2α is present in rat but not in human urine under normal conditions. This implies that urinary 8-epi-PGF2α cannot be used as an index of near-basal oxidant stress in rats. On the other hand, our data further confirm the validity of this marker in man.