全文获取类型
收费全文 | 364449篇 |
免费 | 24172篇 |
国内免费 | 8064篇 |
专业分类
耳鼻咽喉 | 4496篇 |
儿科学 | 10309篇 |
妇产科学 | 6967篇 |
基础医学 | 30092篇 |
口腔科学 | 8276篇 |
临床医学 | 39600篇 |
内科学 | 46617篇 |
皮肤病学 | 4976篇 |
神经病学 | 21248篇 |
特种医学 | 9502篇 |
外国民族医学 | 34篇 |
外科学 | 39123篇 |
综合类 | 52959篇 |
现状与发展 | 12篇 |
一般理论 | 32篇 |
预防医学 | 38483篇 |
眼科学 | 6093篇 |
药学 | 31214篇 |
391篇 | |
中国医学 | 31172篇 |
肿瘤学 | 15089篇 |
出版年
2023年 | 5945篇 |
2022年 | 10658篇 |
2021年 | 14567篇 |
2020年 | 13455篇 |
2019年 | 19140篇 |
2018年 | 16822篇 |
2017年 | 13664篇 |
2016年 | 11163篇 |
2015年 | 10445篇 |
2014年 | 21280篇 |
2013年 | 23057篇 |
2012年 | 19298篇 |
2011年 | 20898篇 |
2010年 | 16745篇 |
2009年 | 15486篇 |
2008年 | 15219篇 |
2007年 | 15615篇 |
2006年 | 13600篇 |
2005年 | 11847篇 |
2004年 | 9671篇 |
2003年 | 8508篇 |
2002年 | 6713篇 |
2001年 | 6002篇 |
2000年 | 4931篇 |
1999年 | 4323篇 |
1998年 | 3564篇 |
1997年 | 3397篇 |
1996年 | 2916篇 |
1995年 | 2806篇 |
1994年 | 2689篇 |
1993年 | 2167篇 |
1992年 | 2183篇 |
1991年 | 1874篇 |
1990年 | 1679篇 |
1989年 | 1508篇 |
1988年 | 1404篇 |
1987年 | 1242篇 |
1985年 | 3927篇 |
1984年 | 4929篇 |
1983年 | 3436篇 |
1982年 | 3896篇 |
1981年 | 3631篇 |
1980年 | 3228篇 |
1979年 | 2972篇 |
1978年 | 2588篇 |
1977年 | 1945篇 |
1976年 | 2175篇 |
1975年 | 1653篇 |
1974年 | 1451篇 |
1973年 | 1302篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
牙根发育不良疾病的研究进展 总被引:2,自引:0,他引:2
牙根发育不良疾病是牙齿根部生理性发育出现障碍的疾病。其发病率为1%~10%,乳、恒牙列均可发生,其结果可导致牙根缺如或短根,严重者可造成牙齿过早脱落。国外学者将该疾病统称为短根异常疾病。其发病因素有遗传性疾病、全身性疾病、外源性因素和医源性因素等。 相似文献
102.
全营养素混合液(TNA)在肠外营养的应用 总被引:2,自引:0,他引:2
脂肪乳剂、葡萄糖、氨基酸、电解质、维生素及微量元素按一定程序混合配成10种全营养素混合液。在4℃14天贮存期内,10种混合液的pH和渗透压变化不大,不同混合液在不同时期的脂粒平均直径变化为0.3135±0.1012μm~0.4813±0.1893μm,94.93%脂粒的直径<0.6μm,无直径>6μm的脂粒,细菌培养阴性。74例共输全营养素混合液1,796次,无不良临床反应和异常实验室检查结果;用1周以上者大都显示氮平衡改善,用2周以上者血清转铁蛋白和白蛋白浓度可有不同程度升高。 相似文献
103.
The complex enterprise of modelling prenatal exposure to cigarettes: what is ‘enough’? 总被引:1,自引:0,他引:1
Kate E. Pickett Paul J. Rathouz Vanja Dukic Kristen Kasza Marina Niessner Rosalind J. Wright Lauren S. Wakschlag 《Paediatric and perinatal epidemiology》2009,23(2):160-170
While there is a burgeoning body of research linking smoking during pregnancy to problem behaviour in offspring, a major criticism of this work has been the crude measurement of exposure in these studies (e.g. retrospective, self-reported only) that could lead to biased estimates. To address this issue, we used a pregnancy cohort with repeated prospective measures of exposure as well as biological assays to generate estimates of exposure patterns using a range of modelling techniques. In this paper we report on the analytical approaches we have developed, including patterns of exposure over time and best-estimate approaches that combine self-report and cotinine measures, and compare their predictive value in relation to different dimensions of fetal growth as a first step towards examining the utility of greater precision of exposure measurement.
Surprisingly, in this sample the more complex assessments of exposure, including biological measures, generally did not perform better than simple indicators of exposure based on repeated self-report measures, with one exception: a combined self-report cotinine 'best estimate' of third trimester exposure was uniquely associated with lower brain : body ratio. Further study is needed using more sophisticated cotinine assays and testing prediction of a range of outcomes to ascertain whether these findings represent true differences or are specific to the sample, methods and outcomes used. Such research will inform the development of guidelines for adequate exposure characterisation in developmental studies. 相似文献
Surprisingly, in this sample the more complex assessments of exposure, including biological measures, generally did not perform better than simple indicators of exposure based on repeated self-report measures, with one exception: a combined self-report cotinine 'best estimate' of third trimester exposure was uniquely associated with lower brain : body ratio. Further study is needed using more sophisticated cotinine assays and testing prediction of a range of outcomes to ascertain whether these findings represent true differences or are specific to the sample, methods and outcomes used. Such research will inform the development of guidelines for adequate exposure characterisation in developmental studies. 相似文献
104.
105.
106.
G Titeca†§ F Poot†§ D Cassart‡ B Defays† D Pirard†§ M Comas† P Vereecken†¶†† V Verschaevec P Simon† M Heenen† 《Journal of the European Academy of Dermatology and Venereology》2007,21(6):771-776
BACKGROUND: Breast cancer is the most common cancer in women and therefore represents a major problem in public health. Data from patients' self-report questionnaires provide valuable information about the side-effects that patients may view as having a significantly detrimental impact on their quality of life (QOL) and yet are not always recognized as important by healthcare professionals. Cosmetology is a specific care for patients and there is actually no scientific evidence regarding effects on QOL for women with breast cancer. OBJECTIVE: The purpose of this study is to assess the impact of cosmetic care on QOL in breast cancer patients during chemotherapy and radiotherapy. METHODS: We developed a prospective, multicentre, randomized, controlled study including 27 patients. All the patients had to fill in a French-validated dermatologic specific quality-of-life questionnaire to compare the QOL of the two groups, the cosmetic group and the control group, at three different times of the adjuvant treatment. RESULTS: The results show a statistically significant difference between the cosmetic group and the control group in two areas of QOL: mood state and self-perception of the disease. CONCLUSION: This study emphasizes the interest of cosmetic care in breast cancer patients. However, further larger trials are needed to confirm this study. 相似文献
107.
W.-S. Ahn D.-J. Kim† G.-T. Chae‡ J.-M. Lee S.-M. Bae§ J.-I. Sin§ Y.-W. Kim§ S.-E. Namkoong & I. P. Lee 《International journal of gynecological cancer》2004,14(4):589-594
A mushroom extract, Agaricus blazei Murill Kyowa (ABMK), has been reported to possess antimutagenic and antitumor effects. Here, we investigate the beneficial effects of ABMK consumption on immunological status and qualities of life in cancer patients undergoing chemotherapy. One hundred cervical, ovarian, and endometrial cancer patients were treated either with carboplatin (300 mg / m(2)) plus VP16 (etoposide, 100 mg / m(2)) or with carboplatin (300 mg / m(2)) plus taxol (175 mg / m(2)) every 3 weeks for at least three cycles with or without oral consumption of ABMK. We observed that natural killer cell activity was significantly higher in ABMK-treated group (ANOVA, n = 39, P < 0.002) as compared with nontreated placebo group (n = 61). However, no significant difference in lymphokine-activated killer and monocyte activities was observed in a manner similar to the count of specific immune cell populations between ABMK-treated and nontreated groups. However, chemotherapy-associated side effects such as appetite, alopecia, emotional stability, and general weakness were all improved by ABMK treatment. Taken together, this suggests that ABMK treatment might be beneficial for gynecological cancer patients undergoing chemotherapy. 相似文献
108.
眼轴线后部眶容积增大与眼球内陷比值的测定研究 总被引:1,自引:0,他引:1
目的:通过测量眼眶爆裂性骨折伴有眼眶扩大患者的后部眼眶容积、观察眼球内陷出现的时间及程度,研究后部眶容积扩大与眼球内陷的关系比值,为病情预测和眶内填充手术提供比较精确的参考数据。方法:将96例患者按发病时间分为早期病例组(60例、受伤时间1周以内)和晚期病例组(36例、受伤时间3个月以上),早期组除进行后部眼眶容积测量外,分别于1周、2周、3周测定眼球突出度(相差>1mm为阳性),记录眼球内陷出现时间,用卡方检验进行统计学分析;晚期组测量后部眶容积增大值和眼球内陷量,对其相关性采用Pearson统计方法进行统计学分析,并得出回归方程及相关系数。结果:早期组60例患者中,(58.33%)例患者在1周内出现眼球内陷,4(880%)例在2周内出现内陷,3周时有5(388.33%)例呈现出内陷;2周时出现眼球内陷的例数与1周时有显著性差异(χ2=62.484,P<0.001),2周时出现眼球内陷例数与3周时无差异(χ2=1.563,P>0.05),1周时出现眼球内陷例数与3周时有显著差异(χ2=76.885,P<0.001),后部眶容积增大与眼球内陷的比值约为1.0,两者之间呈正相关(r=0.994,P<0.001),即后部眶容积每增加1ml,产生1.0mm的眼球内陷。结论:眼球内陷通常于伤后2周~3周出现,3个月时趋向稳定;后部眶容积增大与眼球内陷产生比值为1.0,呈正相关;后部眶容积扩大与眼球内陷比值可预测发生眼球内陷的可能性和程度,为手术矫正眼球内陷提供可靠、精确的参考,具有十分重要的临床指导意义。 相似文献
109.
护士执业权是依法取得护士执业证书,以护士名义为社会提供护理服务的医务人员进行护理工作的权利和相关权益,是护士执业规则的核心内容,护士执业权属于公民劳动权益的范畴,是一种具有职业特权性质的特殊劳动权,应立法保护。本文试图通过对护士执业权的法理初步探讨,结合目前存在的侵害护士执业权的突出现象分析,提出保护该项权利的立法建议。 相似文献
110.
骨外科患者拔尿管时注入药物对排尿的影响 总被引:4,自引:0,他引:4
目的探讨提高长时间留置导尿管病人拔管后2h内排尿成功率的方法。方法按入院先后随机将64例导尿的男性骨折病人分两组,单数为观察组,双数为对照组。对照组常规拔尿管,观察组拔尿管时遵医嘱注入地塞米松5mg+2%利多卡因5ml+生理盐水5ml+庆大霉素8万U,比较首次排尿的自觉症状,包括尿痛、排尿困难、排尿障碍等。结果观察组较对照组病人首次排尿出现自觉症状的例数明显减少(P<0.01),有显著性差异。结论拔尿管时注入药物安全有效,明显提高了长期置管病人拔除尿管后首次排尿的成功率,减轻了病人的痛苦,有广泛的应用价值。 相似文献