全文获取类型
收费全文 | 90177篇 |
免费 | 8540篇 |
国内免费 | 6107篇 |
专业分类
耳鼻咽喉 | 808篇 |
儿科学 | 1134篇 |
妇产科学 | 1347篇 |
基础医学 | 10378篇 |
口腔科学 | 1749篇 |
临床医学 | 11444篇 |
内科学 | 13155篇 |
皮肤病学 | 966篇 |
神经病学 | 4879篇 |
特种医学 | 3293篇 |
外国民族医学 | 60篇 |
外科学 | 8765篇 |
综合类 | 14459篇 |
现状与发展 | 29篇 |
一般理论 | 9篇 |
预防医学 | 6643篇 |
眼科学 | 2289篇 |
药学 | 10026篇 |
116篇 | |
中国医学 | 5803篇 |
肿瘤学 | 7472篇 |
出版年
2024年 | 365篇 |
2023年 | 1527篇 |
2022年 | 3987篇 |
2021年 | 5117篇 |
2020年 | 3796篇 |
2019年 | 3182篇 |
2018年 | 3326篇 |
2017年 | 3020篇 |
2016年 | 2883篇 |
2015年 | 4156篇 |
2014年 | 5154篇 |
2013年 | 4736篇 |
2012年 | 7028篇 |
2011年 | 7730篇 |
2010年 | 4956篇 |
2009年 | 3889篇 |
2008年 | 4880篇 |
2007年 | 4784篇 |
2006年 | 4611篇 |
2005年 | 4316篇 |
2004年 | 3057篇 |
2003年 | 2872篇 |
2002年 | 2521篇 |
2001年 | 1715篇 |
2000年 | 1629篇 |
1999年 | 1660篇 |
1998年 | 1094篇 |
1997年 | 993篇 |
1996年 | 749篇 |
1995年 | 706篇 |
1994年 | 598篇 |
1993年 | 392篇 |
1992年 | 462篇 |
1991年 | 401篇 |
1990年 | 359篇 |
1989年 | 300篇 |
1988年 | 311篇 |
1987年 | 261篇 |
1986年 | 248篇 |
1985年 | 200篇 |
1984年 | 136篇 |
1983年 | 101篇 |
1982年 | 58篇 |
1981年 | 58篇 |
1980年 | 40篇 |
1979年 | 99篇 |
1978年 | 41篇 |
1975年 | 40篇 |
1974年 | 52篇 |
1973年 | 30篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
住院糖尿病病人病情分析 总被引:1,自引:0,他引:1
目的:通过对近年来我院住院糖尿病病人的资料分析,观察糖尿病转归、并发症的发生率及死亡原因.方法:查阅全院住院糖尿病病人病历,对患者的相关临床资料登记.结果:糖尿病患病率呈逐年增加的趋势,与1993年相比,1997年患病率增加0.5倍,1998年患病率增加1倍,2001年前半年增加2倍.2001年上半年住院糖尿病病人高血压、冠心病和心梗的患病率分别为39.1%,35.2%和6.7%,住院高血压病人糖尿病患病率由1998年的6%增至2001年的9%,住院冠心病病人糖尿病患病率增高约10%(P<0.01).住院心梗病人糖尿病患病率增高约15%(P<0.05).近3.5年,有2618例糖尿病病人住院(1.95%),与非糖尿病病人相比,病死率无显著性差异.糖尿病主要死亡原因为感染(41.2%),终末期肾病(39.2%)及癌症(31.4%).由于冠心病及脑血管意外死亡仅为15%及13%,而呼吸道感染(81%)及足感染(63%)为主要死因.结论:近8.5年中,在33 005病人中糖尿病病人逐年增多,特别是在近4年中,提高约2倍.高血压、冠心病及心梗病人糖尿病患病率逐年增高.近3.5年中住院糖尿病病人的死亡主要原因并非是心血管病变,而是感染.糖尿病病人癌症病死率有所增加.提倡早期诊断,早期预防,早期治疗糖尿病,采取健康的生活方式. 相似文献
52.
53.
Guo-Wei Ma Martin Pytel Ana Luisa Trejos Victoria Hornblower Jennifer Smallwood Rajni Patel Aaron Fenster Richard A Malthaner 《Computer aided surgery》2007,12(5):270-277
OBJECTIVE: Interstitial brachytherapy is becoming an accepted treatment option for lung cancer patients for whom surgery poses a high risk. Robotic surgery has the potential to deliver brachytherapy seeds into tumors while keeping surgeons at a safe distance from the radioactive source. Our aim was to compare the accuracy, number of attempts, and time needed to place seeds next to a target when using a manual technique, video-assisted thoracoscopic surgery (VATS), and the ZEUS robot for minimally invasive surgery (MIS). METHODS: A brachytherapy seed injector was developed and attached to one of the ZEUS robotic arms. Four subjects each inserted inactive dummy brachytherapy seeds into clear agar-gelatin cubes containing a 1.6-mm stainless steel ball target. Two orthogonal radiographs were taken of each agar cube, and the corresponding distances were measured in triplicate using ImageJ processing software. The mean distance between the center of each seed and the corresponding target was calculated using the Pythagorean theorem. Comparisons were made using analysis of variance, t-tests, and Kruskal-Wallis tests, as appropriate. RESULTS: A total of 384 tests (128 for each technique) were performed. The median accuracies for the manual technique, VATS, and ZEUS were 1.8 mm (range: 0.9-6.7 mm), 2.4 mm (range: 1.0-11.3 mm), and 3.6 mm (range: 1.3-16.7 mm), respectively (p < 0.01). The median numbers of attempts for the manual technique, VATS, and ZEUS were 1 (range: 1-5), 4 (range: 1-14), and 3 (range: 1-20), respectively (p < 0.01). The median times for the manual technique, VATS, and ZEUS were 3.0 s (range: 1-43 s), 86.5 s (range: 6-372 s), and 64.5 s (range: 5-356 s), respectively (p < 0.01). CONCLUSIONS: The manual technique is the most accurate, least traumatic, and fastest method of inserting seeds into tumors. The ZEUS robotic platform was able to place seeds beside a target within a clinically acceptable distance, with an acceptable amount of trauma and time required. It achieved results equal to or better than those obtained with VATS. 相似文献
54.
生长抑素受体显像近年来研究较多,depreotide已成为其研究热点之一。Depreotide在诊断与鉴别诊断临床常见的孤立性肺结节方面有其独特优势;此外,^99mTc—depreotide生长抑素受体显像在乳腺癌、甲状腺癌、淋巴瘤等肿瘤及甲状腺相关性眼病等非肿瘤性疾病也有一定应用前景。 相似文献
55.
老年认知功能障碍与脑结构CT测量的相关性研究 总被引:1,自引:1,他引:0
目的探讨脑萎缩与老年认知功能障碍之间的相关性。方法对开滦集团公司1063名离退休职工进行健康查体,用简易精神状态量表(MMSE)评定认知功能,按分界值将本次研究对象分为认知功能障碍组和认知功能正常组,同时用CT线性测量脑的相关部位以诊断脑萎缩情况,并对各型脑萎缩与认知功能的相关系数及提示老年认知功能障碍的敏感度、特异度、准确度进行分析。结果1063名观察对象中符合入选标准并资料完整者共计511名,其中108名有认知功能障碍,髓质脑萎缩55名、皮质萎缩5名、混合型萎缩30名;认知功能正常者403名,髓质脑萎缩214名、皮质萎缩13名、混合型萎缩62名。认知功能障碍组脑萎缩的发病率高于认知功能正常组,差异具有统计学意义(P<0.005);2组间颞叶海马钩回间距(26.86mm±3.73mmvs25.95mm±3.80mm)及海马钩回间距/大脑左右径的比值(0.21±0.02vs0.20±0.02)差异具有统计学意义(P<0.05);海马钩回间距、皮质脑萎缩、混合型脑萎缩与认知功能障碍呈负相关(分别为r=-0.094,P=0.034,r=-0.156,P≈0.000,r=-0.147,P≈0.000),以海马钩回间距20mm提示老年认知功能障碍的敏感度最高(98.14%),混合型脑萎缩的特异度(84.86%)、准确度最高(72.80%)。结论CT测量相关脑结构,判断脑萎缩类型可以为老年认知功能障碍的诊断提供有价值的信息。 相似文献
56.
Ramirez Claudia C. MD Ma Fangchao MD PhD Federman Daniel G. MD † Kirsner Robert S. MD PhD ‡§ 《Dermatologic surgery》2005,31(7):748-753
Background Results from in vitro and animal studies suggest that cyclooxygenase (COX) inhibitors may reduce the risk of melanoma, but among humans, the evidence remains limited.
Objective In a pilot retrospective cohort, to determine the relationship between the use of COX inhibitors and the incidence, recurrence, and metastases of melanoma in high-risk patients.
Methods Reviewing computerized records at the Miami Veterans Affairs Medical Center, we retrospectively examined the association between COX inhibitor use and melanoma incidence, recurrence, and metastases in high-risk subjects: white subjects previously diagnosed with melanoma (1996–2003). We evaluated three potential outcomes: new melanoma diagnosis, recurrence of a previous melanoma, and melanoma metastasis.
Results Eighty-three subjects with melanoma were included. There was one metastasis among 28 subjects prescribed COX inhibitors, whereas four new melanomas (7.3%), two melanoma recurrences, and six metastases (10.9%) occurred among 55 patients not prescribed COX inhibitors. Although no individual outcomes measures reached statistical significance, combining the three measures, these were significantly lower in users of COX inhibitors compared with nonusers (1 vs 12; p = .05 ). After adjustment for age and tumor depth of invasion, COX inhibitor users had significantly lower rates of melanoma outcome measures (odds ratio 0.08; 95% confidence interval 0.01–0.77; p = .03 ).
Conclusion Potential exists for chemoprevention of melanoma among high-risk patients. 相似文献
Objective In a pilot retrospective cohort, to determine the relationship between the use of COX inhibitors and the incidence, recurrence, and metastases of melanoma in high-risk patients.
Methods Reviewing computerized records at the Miami Veterans Affairs Medical Center, we retrospectively examined the association between COX inhibitor use and melanoma incidence, recurrence, and metastases in high-risk subjects: white subjects previously diagnosed with melanoma (1996–2003). We evaluated three potential outcomes: new melanoma diagnosis, recurrence of a previous melanoma, and melanoma metastasis.
Results Eighty-three subjects with melanoma were included. There was one metastasis among 28 subjects prescribed COX inhibitors, whereas four new melanomas (7.3%), two melanoma recurrences, and six metastases (10.9%) occurred among 55 patients not prescribed COX inhibitors. Although no individual outcomes measures reached statistical significance, combining the three measures, these were significantly lower in users of COX inhibitors compared with nonusers (1 vs 12; p = .05 ). After adjustment for age and tumor depth of invasion, COX inhibitor users had significantly lower rates of melanoma outcome measures (odds ratio 0.08; 95% confidence interval 0.01–0.77; p = .03 ).
Conclusion Potential exists for chemoprevention of melanoma among high-risk patients. 相似文献
57.
Ana Teresa Timóteo Andreia Mamede Maria de Lurdes Ferreira José Serra José Alberto Oliveira Rui Cruz Ferreira Jorge Quininha 《Revista portuguesa de cardiologia》2007,26(2):135-143
BACKGROUND: Nitrate therapy can induce ischemic preconditioning with a consequent increase in tolerance to ischemia. In the context of acute coronary syndromes (ACS), nitrates may result in a different presentation. with greater protection. OBJECTIVES: To investigate in a population of patients with ACS whether previous chronic use of nitrates results in a different presentation of ACS. METHODS: We studied 287 patients (65 +/- 13 years, 66% male) admitted to our department in the first six months of 2005 with ACS (with and without ST-segment elevation). Of these, 8% were under nitrate therapy at the time of admission. In this group, 27% presented ACS without ST-segment elevation, while in the group without nitrates this value was 58% (p = 0.005). By univariate analysis, the use of nitrates was a predictor of the preferential occurrence of non-ST-segment elevation ACS (OR 0.27, 95% CI 0.10-0.71). After correction for the potential influence of variables (age, gender, previous revascularization and smoking) by multivariate logistic regression, nitrate therapy remained a borderline predictor of clinical presentation as non-ST-segment elevation ACS (OR 0.37, 95% CI 0.13-1.04, p = 0.059). CONCLUSIONS: Previous use of nitrates was associated with a tendency to present as non-ST-segment elevation ACS. This finding may be explained by the hypothesis that nitrates induce pharmacological preconditioning, reducing the transmural extent of myocardial infarction. 相似文献
58.
无症状性炎性前列腺炎对血清PSA、fPSA的影响 总被引:3,自引:0,他引:3
目的 探讨无症状性炎性前列腺炎(NIH分类Ⅳ型)对血清PSA、fPSA的影响。方法 对比分析36例NIH分类Ⅳ型、42 例有症状性慢性前列腺炎(NIH分类ⅢA型)患者以及22例健康对照组的血清PSA、fPSA、fPSA/tPSA之间的差异。结果 血 清PSA、fPSA、fPSA/tPSA在Ⅳ型和ⅢA型前列腺炎患者间差异无显著性(P>0.05),但与正常对照组比较差异有显著性(P< 0.01)。结论 NIH分类Ⅳ型前列腺炎可引起血清PSA、fPSA升高。对无症状、高血清PSA患者行前列腺活检前,应考虑到患 Ⅳ型前列腺炎的可能。 相似文献
59.
Z. Peng Q. Liu Q. Wang E. Rector Y. Ma R. Warrington 《Clinical and experimental allergy》2007,37(7):1040-1048
BACKGROUND: Immunotherapy with anti-IgE antibodies for treatment of allergy is promising but a short half-life and extremely high cost limit its application. OBJECTIVE: We sought to develop IgE vaccines that induce longer-lasting auto-antibodies to neutralize self-IgE as an alternative therapy. METHODS: The vaccine was made by conjugating three synthetic peptides corresponding to human IgE receptor-binding sites to a carrier, hepatitis B surface antigen. To test the immunogenicity of the vaccine, rats were immunized with the vaccine or hepatitis B surface antigen as control. Serum IgG titres to human IgE and the IgE of other species were measured. The inhibition by rat antisera of the binding of human IgE to its receptor was assessed by ELISA, flow cytometry analysis, and passive cutaneous anaphylaxis (PCA), and its ability to recognize receptor-bound IgE was examined. The in vivo effect of the vaccine was evaluated in trichosanthin-sensitized mice and rats. In the preventative study, vaccination started before sensitization commenced, while in the treatment study, vaccination started after sensitization. Sensitized mice and rats receiving injections of the carrier served as controls. Trichosanthin-specific IgE was measured using PCA. RESULTS: Sera from vaccine-immunized rats contained high titre antibodies that reacted with soluble and plate-bound but not with receptor-bound human IgE; they also reacted with mouse, rat, and dog IgE. Furthermore, the sera inhibited the binding of human IgE to its receptor in a dose-dependent manner. In preventative and treatment studies, serum trichosanthin-specific IgE levels were significantly reduced in vaccinated groups compared with controls. CONCLUSION: Antibodies against self-IgE can be induced by IgE peptide-based vaccines, which are effective in preventing the increase of IgE and in down-regulating IgE in sensitized animals. 相似文献
60.