全文获取类型
收费全文 | 38535篇 |
免费 | 3317篇 |
国内免费 | 1739篇 |
专业分类
耳鼻咽喉 | 434篇 |
儿科学 | 662篇 |
妇产科学 | 661篇 |
基础医学 | 4650篇 |
口腔科学 | 695篇 |
临床医学 | 4180篇 |
内科学 | 6268篇 |
皮肤病学 | 878篇 |
神经病学 | 2507篇 |
特种医学 | 1338篇 |
外国民族医学 | 14篇 |
外科学 | 4678篇 |
综合类 | 5145篇 |
现状与发展 | 5篇 |
一般理论 | 20篇 |
预防医学 | 2511篇 |
眼科学 | 1344篇 |
药学 | 3216篇 |
22篇 | |
中国医学 | 1436篇 |
肿瘤学 | 2927篇 |
出版年
2024年 | 56篇 |
2023年 | 467篇 |
2022年 | 902篇 |
2021年 | 1685篇 |
2020年 | 1207篇 |
2019年 | 1219篇 |
2018年 | 1322篇 |
2017年 | 1150篇 |
2016年 | 1160篇 |
2015年 | 1518篇 |
2014年 | 1901篇 |
2013年 | 1828篇 |
2012年 | 2732篇 |
2011年 | 2803篇 |
2010年 | 1655篇 |
2009年 | 1380篇 |
2008年 | 1990篇 |
2007年 | 2102篇 |
2006年 | 2010篇 |
2005年 | 1936篇 |
2004年 | 1615篇 |
2003年 | 1505篇 |
2002年 | 1345篇 |
2001年 | 1113篇 |
2000年 | 1001篇 |
1999年 | 876篇 |
1998年 | 488篇 |
1997年 | 427篇 |
1996年 | 322篇 |
1995年 | 332篇 |
1994年 | 252篇 |
1993年 | 190篇 |
1992年 | 320篇 |
1991年 | 306篇 |
1990年 | 294篇 |
1989年 | 268篇 |
1988年 | 229篇 |
1987年 | 218篇 |
1986年 | 213篇 |
1985年 | 166篇 |
1984年 | 120篇 |
1983年 | 86篇 |
1982年 | 57篇 |
1981年 | 60篇 |
1979年 | 83篇 |
1978年 | 60篇 |
1977年 | 62篇 |
1974年 | 66篇 |
1973年 | 61篇 |
1972年 | 64篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Mak KH Chan CN Neoh KH Damras T Koh TH Tan HC Lim TT Lau KW Lim YT Lim YL 《The Journal of invasive cardiology》2002,14(5):239-242
The Terumo stent is a new, balloon-expandable, stainless-steel device with a unique multicellular design to provide robust radial force and end-stoppers to prevent dislodgement. We evaluated the early and late clinical and angiographic outcomes of Terumo coronary stent implantation in native coronary arteries using an open, nonrandomized 3-center registry. From July 1998 to June 1999, a total of 118 Terumo stents were implanted in 105 patients (mean age, 58 +/- 10 years). A significant proportion of patients suffered from diabetes (34%), prior myocardial infarction (MI; 43%) and unstable angina (31%). Most target lesions (48%) had unfavorable morphological characteristics (type B2 or C); mean reference luminal diameter was 2.76 +/- 0.41 mm and lesion length was 11.4 +/- 5.3 mm. Primary success in stent deployment was achieved in 103 patients (98%). There was 1 patient with acute stent thrombosis in whom 2 overlapping stents were deployed. Following stenting, the minimal luminal diameter increased from 1.04 +/- 0.48 mm to 2.39 +/- 0.33 mm. Six-month angiography was performed in 97 patients (92%), and the binary angiographic restenosis (> or = 50% narrowing) rate was 16%. Late loss index was 0.50 +/- 0.43. By 6 months, two patients (1.9%) died, two patients (1.9%) had Q-wave MI and 9 patients (8.4%) required repeat coronary interventions. Therefore, our study shows that the Terumo stent is potentially safe and efficacious in the treatment of coronary narrowings, even in the presence of unfavorable clinical conditions and complex lesion morphological characteristics. 相似文献
992.
Liao G Wang Y Chang J Bian T Tan W Sun M Li W Yang H Chen J Zhang X Bi S Omata M Jiang S 《Hepatology (Baltimore, Md.)》2008,47(1):25-34
DNA immunization has been used to induce either humoral or cellular immune responses against many antigens, including hepatitis C virus (HCV). In addition, DNA immunizations can be enhanced or modulated at the nucleotide level. Genetic immunizations were examined in BALB/c mice through the use of plasmids and chimeric DNA constructs encoding HCV core proteins and hepatitis B virus (HBV) precore (preC) regions. Plasmids encoding the truncated HCV core induced potent humoral and cellular responses to HCV; pcDNA3.0A-C154 produced a stronger antibody response than pcDNA3.0A-C191 (P < 0.01) and pcDNA3.0A-C69 (P < 0.05). HBV preC enhanced the humoral and cellular immune responses of BALB/c mice to HCV; however, pcDNA3.0A-C69preC resulted in a weak cytotoxic T lymphocyte (CTL) response. In addition, the humoral and cellular immune responses to HCV of groups immunized with pcDNA3.0A-C154preC and pcDNA3.0A-C191preC plasmids were higher than those of groups immunized with pcDNA3.0A-C154 and pcDNA3.0A-C191. In vivo CTL responses verified that mice immunized with preC core fused DNAs showed significantly high specific lysis compared with mice immunized with HCV cores only (P < 0.01). In our study, pcDNA3.0A-C154preC led to the highest immune response among all DNA constructs. Conclusion: DNA that encodes truncated HCV core proteins may lead to increased immune responses in vivo, and these responses may be enhanced by HBV preC. 相似文献
993.
G Reimer K M Pollard C A Penning R L Ochs M A Lischwe H Busch E M Tan 《Arthritis and rheumatism》1987,30(7):793-800
A monoclonal IgG2a antinucleolar autoantibody (72B9) was obtained by fusion of spleen cells from a (New Zealand black x New Zealand white)F1 mouse with myeloma cells (P3x63Ag8.653). Antibody 72B9 recognized a highly conserved nucleolar antigen present in both animal and plant cells. The staining pattern produced by antibody 72B9 in different cell substrates was identical with those obtained by scleroderma antibodies reactive with a basic (pI 8.5) nucleolar protein of Mr 34,000, which is associated with the U3 RNP particle. Western blotting further confirmed its reactivity with this scleroderma-related U3 RNP protein. 相似文献
994.
急性脑梗死病人血浆D-二聚体及CD62p含量的动态变化及其意义 总被引:2,自引:0,他引:2
目的观察急性脑梗死(ACI)病人血浆D-二聚体和CD62p水平的动态变化度其临床意义。方法测定125例ACI病人血浆D-二聚体和CD62p水平,并设健康对照组(60名)对比研究。结果脑梗死病人不同病期D-二聚体和CD62p水平均明显高于健康对照组(P〈0.05或P〈0.01)。D-二聚体和CD62p水平与梗死面积成正相关。结论ACI病人血浆D-二聚体和CD62p水平升高,这与体内血液凝固性增强和血小板活化有关。测定血D-二聚体和CD62p水平对ACI病情预测和辅助诊断具有重要意义。 相似文献
995.
Hypotensive Effects and Mechanisms of Adrenomedullin(13-52) 总被引:10,自引:0,他引:10
Adrenomedul1in(AdM)isarecentlydescribed52aminoacidpeptidepresentintheplasmaofnormalman[l1,AdMwasinitiallyisolatedfrompheochromocytomatissueandhasbeenfoundtobesynthesizedbyavarietyoforgansystemsincludingthekidney,adrenalgland,1ung,heartandspleen[="j.Whenadministeredasbolusinjectionsintoanormotensiverat,humanAdMdecreasedb1oodpressure['.'.']andsystemicvascularre-sistance[5].BasedontheseobservationslitwasconcludedthatAdMmayplayanimportantroleinb1oodpressurecontro1[l].However,theeffectsofAdMonh… 相似文献
996.
Background: GIRD COPD Biobank is a multicenter observational study blood-based database with local characteristics, in order to investigate the causes, risk factors, pathogenesis, prevalence patterns and trends of COPD and promote new pathogenic insights in China.Methods: We enrolled 855 clinically COPD patients and 660 controls with normal lung function. Extensive data collection has been undertaken with questionnaires, clinical measurements, and collection and storage of blood specimens, following Standard Operating Procedures (SOP). All surveys had similar quality controls, supervisions, and training of the investigator team.Results: Since September 2010, a total of 1515 subjects (1116 [73.7%] males; 855 [56.4%] diagnosed with COPD) were enrolled. Analyses of the design and interim results of the GIRD COPD Biobank Study identified patients with COPD were older, lower educational level, a longer history of pack-year smoking, less in kitchen fan usage, X-ray exposure, and history of disease (P < 0.01 for all); Most of the COPD subjects belonged to moderately severe or worse, stratified according to Global Lung Function Initiative (GLI); COPD patients had relatively more co-morbidities than controls; Environmental hazard exposures might be the main contributors to the reported respiratory symptoms; Cold air, haze, and influenza acted the top three factors to induce respiratory symptoms in both COPD cases and controls.Conclusion: The GIRD COPD Biobank Study has the potential to provide substantial novel insights into the genetics, biomarkers, environmental and lifestyle aspects of COPD. It is expected to provide new insights for pathogenesis and the long-term progression of COPD. 相似文献
997.
998.
OBJECTIVE: The aim of this study was to summarize experiences of patients admitted to the intensive care unit (ICU) for an acute exacerbation of COPD and to identify factors associated with a poor outcome. METHODOLOGY: An observational case series of 102 consecutive admissions to the ICU for acute exacerbation of COPD between January 1998 and December 2002 were studied. RESULTS: In total, 102 admissions to the ICU were reviewed. There were no ICU deaths but there were 18 hospital deaths (18%). A total of 28 patients were treated with non-invasive positive pressure ventilation (NIPPV), of whom four (14% failure rate) subsequently required intubation and mechanical ventilation (MV). Another 16 patients (16%) were successfully weaned from MV with NIPPV. Nine patients (9%), who had more than one episode of re-intubation after weaning (RAW), were from the mechanically ventilated group. Tracheostomy was performed for four patients (3.9%). The median duration of both NIPPV and MV was 1 day. The median length of stay in the ICU and hospital were 2 days (SD, 7.2) and 8 days (SD, 9.6), respectively. Univariate analysis identified serum total protein to be associated with hospital mortality (P = 0.004) CONCLUSION: For patients with acute exacerbations of COPD in the ICU, serum total protein, a surrogate marker for nutrition, was significantly associated with hospital mortality. 相似文献
999.
Serum adiponectin is reduced in acromegaly and normalized after correction of growth hormone excess 总被引:4,自引:0,他引:4
Lam KS Xu A Tan KC Wong LC Tiu SC Tam S 《The Journal of clinical endocrinology and metabolism》2004,89(11):5448-5453
Adiponectin, an adipocyte-derived hormone, possesses insulin-sensitizing, antiinflammatory, and antiatherogenic properties. We hypothesized that hypoadiponectinemia was present in acromegaly, as in other conditions with increased insulin resistance and cardiovascular risk. Using an in-house RIA, serum adiponectin was determined in 35 patients with active acromegaly and 35 age-, sex-, and body mass index-matched healthy controls. Twenty-five patients were restudied after GH-lowering therapies. Serum adiponectin was significantly reduced in the acromegalic patients (4.3 +/- 1.8 vs. 6.7 +/- 1.8 microg/ml in controls; P < 0.001), but was increased after treatment with Sandostatin LAR, a long-acting somatostatin analog (5.8 +/- 2.6 vs. 3.8 +/- 1.6 microg/ml pretreatment; P < 0.001; n = 15) or transsphenoidal surgery (6.5 +/- 2.7 vs. 3.9 +/- 1.5 microg/ml preoperation; P < 0.01; n = 10). Fasting insulin was an independent determinant of serum adiponectin levels (P < 0.01) in control subjects, contributing to 11.7% of the variance in circulating adiponectin. In cultured 3T3-L1 adipocytes, adiponectin mRNA levels were decreased by insulin (1.5 microm; P < 0.005) or IGF-I (1 microg/ml; P < 0.05), but not by GH (1 microm) or somatostatin (1 microm). In conclusion, hypoadiponectinemia is present in active acromegaly, probably secondary to the inhibitory effect of high circulating insulin levels. Hypoadiponectinemia, reversible with GH-lowering therapies, may contribute to the increased insulin resistance and cardiovascular risk in patients with acromegaly. 相似文献
1000.
目的研究局灶性癫痫患儿与健康儿童肠道菌群是否不同,以及癫痫患儿治疗前后肠道菌群的变化。方法招募未经治疗的初诊局灶性癫痫患儿10例为病例组,且均用单药奥卡西平治疗。收集患儿临床资料,以及治疗前和治疗3个月后的粪便标本;另招募相同年龄段的健康儿童14例为对照组。提取粪便标本中细菌总DNA,进行16S rDNA测序,并行生物信息学分析。结果病例组经奥卡西平治疗3个月后癫痫发作频率减少>50%。门水平方面,治疗前组放线菌门丰度高于治疗后组和对照组(P<0.05);属水平方面,治疗前组埃希菌/志贺菌属、链球菌属、柯林斯菌属和巨单胞菌属丰度高于对照组(P<0.05),经治疗后其丰度降低(P<0.05)。结论与健康儿童相比,局灶性癫痫患儿的肠道菌群存在显著差异;奥卡西平可以显著改善癫痫症状,重塑癫痫患儿的肠道菌群。 相似文献