全文获取类型
收费全文 | 5478篇 |
免费 | 416篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 30篇 |
儿科学 | 255篇 |
妇产科学 | 211篇 |
基础医学 | 690篇 |
口腔科学 | 36篇 |
临床医学 | 588篇 |
内科学 | 1140篇 |
皮肤病学 | 83篇 |
神经病学 | 610篇 |
特种医学 | 103篇 |
外科学 | 511篇 |
综合类 | 55篇 |
一般理论 | 5篇 |
预防医学 | 748篇 |
眼科学 | 50篇 |
药学 | 377篇 |
中国医学 | 16篇 |
肿瘤学 | 399篇 |
出版年
2023年 | 33篇 |
2022年 | 64篇 |
2021年 | 131篇 |
2020年 | 94篇 |
2019年 | 117篇 |
2018年 | 149篇 |
2017年 | 91篇 |
2016年 | 134篇 |
2015年 | 134篇 |
2014年 | 191篇 |
2013年 | 301篇 |
2012年 | 418篇 |
2011年 | 474篇 |
2010年 | 240篇 |
2009年 | 202篇 |
2008年 | 325篇 |
2007年 | 342篇 |
2006年 | 346篇 |
2005年 | 346篇 |
2004年 | 312篇 |
2003年 | 298篇 |
2002年 | 289篇 |
2001年 | 59篇 |
2000年 | 26篇 |
1999年 | 41篇 |
1998年 | 56篇 |
1997年 | 37篇 |
1996年 | 47篇 |
1995年 | 36篇 |
1994年 | 26篇 |
1993年 | 38篇 |
1992年 | 21篇 |
1991年 | 16篇 |
1990年 | 21篇 |
1989年 | 23篇 |
1988年 | 18篇 |
1987年 | 17篇 |
1986年 | 17篇 |
1985年 | 15篇 |
1984年 | 22篇 |
1983年 | 24篇 |
1982年 | 32篇 |
1981年 | 27篇 |
1980年 | 20篇 |
1978年 | 13篇 |
1977年 | 21篇 |
1976年 | 13篇 |
1974年 | 16篇 |
1973年 | 16篇 |
1972年 | 16篇 |
排序方式: 共有5907条查询结果,搜索用时 31 毫秒
71.
Hannelore I. Bax Irma A. J. M. Bakker-Woudenberg Marian T. ten Kate Annelies Verbon Jurriaan E. M. de Steenwinkel 《Antimicrobial agents and chemotherapy》2016,60(4):2577-2579
The in vitro activities of clarithromycin and tigecycline alone and in combination against Mycobacterium avium were assessed. The activity of clarithromycin was time dependent, highly variable, and often resulted in clarithromycin resistance. Tigecycline showed concentration-dependent activity, and mycobacterial killing could only be achieved at high concentrations. Tigecycline enhanced clarithromycin activity against M. avium and prevented clarithromycin resistance. Whether there is clinical usefulness of tigecycline in the treatment of M. avium infections needs further study. 相似文献
72.
Meike Stumpp Marian Y. Hu Frank Melzner Magdalena A. Gutowska Narimane Dorey Nina Himmerkus Wiebke C. Holtmann Sam T. Dupont Michael C. Thorndyke Markus Bleich 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(44):18192-18197
Calcifying echinoid larvae respond to changes in seawater carbonate chemistry with reduced growth and developmental delay. To date, no information exists on how ocean acidification acts on pH homeostasis in echinoderm larvae. Understanding acid–base regulatory capacities is important because intracellular formation and maintenance of the calcium carbonate skeleton is dependent on pH homeostasis. Using H+-selective microelectrodes and the pH-sensitive fluorescent dye BCECF, we conducted in vivo measurements of extracellular and intracellular pH (pHe and pHi) in echinoderm larvae. We exposed pluteus larvae to a range of seawater CO2 conditions and demonstrated that the extracellular compartment surrounding the calcifying primary mesenchyme cells (PMCs) conforms to the surrounding seawater with respect to pH during exposure to elevated seawater pCO2. Using FITC dextran conjugates, we demonstrate that sea urchin larvae have a leaky integument. PMCs and spicules are therefore directly exposed to strong changes in pHe whenever seawater pH changes. However, measurements of pHi demonstrated that PMCs are able to fully compensate an induced intracellular acidosis. This was highly dependent on Na+ and HCO3−, suggesting a bicarbonate buffer mechanism involving secondary active Na+-dependent membrane transport proteins. We suggest that, under ocean acidification, maintained pHi enables calcification to proceed despite decreased pHe. However, this probably causes enhanced costs. Increased costs for calcification or cellular homeostasis can be one of the main factors leading to modifications in energy partitioning, which then impacts growth and, ultimately, results in increased mortality of echinoid larvae during the pelagic life stage. 相似文献
73.
Margje Sinnema Marian A. Maaskant Henny M.J. van Schrojenstein Lantman-de Valk Harm Boer Leopold M.G. Curfs Constance T.R.M. Schrander-Stumpel 《European journal of medical genetics》2013,56(8):397-403
IntroductionAdults with Prader–Willi syndrome (PWS) have an increased occurrence of several medical conditions. We report on the consequences of high morbidity rates such as prevalence rate of hospital admissions, medication use and surgery in a Dutch cohort of adults with PWS. Special attention is paid to causes and symptoms of serious illness.MethodParticipants were contacted via the Dutch Prader–Willi Parent Association and through physicians specializing in persons with ID. The persons with PWS and their main caregivers were visited at home. Information was collected through semi-structured interviews on 102 adults with PWS.ResultsThe need for medical care in the neonatal period is associated with hypotonia and feeding problems. Hospital admissions for respiratory tract infections are frequent. During childhood most hospital admissions were due to PWS syndrome specific surgery. During adolescence hospital admissions occurred for scoliosis surgery and endocrine evaluations. At adult age, hospitalization was associated with inguinal hernia surgery, diabetes mellitus, psychosis, erysipelas, water and drug intoxications. In the older group, respiratory infections were again the main reason for hospital admissions. Frequently used medications at adult age included psychotropics, laxatives, anti-diabetics and dermatologic preparations. Abnormal drinking patterns, problems with anesthesia, decreased ability to vomit, abnormal pain awareness and unpredictable fever responses were frequent and often lead to delayed diagnoses of serious conditions.DiscussionPeople with PWS are frequent users of medical-care. Reasons for hospitalization and medication use are age specific. Knowledge on the different presentation of symptoms in people with PWS is needed. In case of unexplained illness, disturbances of consciousness and behavioral changes in people with PWS, an infection should be ruled out in the first place. Information from this study may help in preventing conditions and recognizing conditions in an early stage. Adequate preventive management and treatment of PWS related morbidity, could reduce medical care use in the long term and could improve quality adjusted life years. 相似文献
74.
75.
Lauren Stevenson Marian Kelley Boris Gorovits Clare Kingsley Heather Myler Karolina Österlund Arumugam Muruganandam Yoshiyuki Minamide Mario Dominguez 《The AAPS journal》2014,16(1):83-88
The L2 Global Harmonization Team on large molecule specific assay operation for protein bioanalysis in support of pharmacokinetics focused on the following topics: setting up a balanced validation design, specificity testing, selectivity testing, dilutional linearity, hook effect, parallelism, and testing of robustness and ruggedness. The team additionally considered the impact of lipemia, hemolysis, and the presence of endogenous analyte on selectivity assessments as well as the occurrence of hook effect in study samples when no hook effect had been observed during pre-study validation. 相似文献
76.
77.
In all cases of obstructive lung disease, smoking cessation, proper use of metered-dose inhalers, up-to-date immunizations, adequate nutrition, and general physical conditioning are important components of treatment. Dr Jacobs summarizes these components as well as stepwise pharmacologic approaches to controlling the inflammation of asthma, the bronchospasm of chronic bronchitis and emphysema, and the symptoms of secondary or coexisting conditions. 相似文献
78.
Polymorphisms in alcohol and tobacco metabolism genes in head and neck cancer in the Basque Country 下载免费PDF全文
79.
80.
Olga Stasikowska-Kanicka Małgorzata Wągrowska-Danilewicz Marian Danilewicz 《Pathology oncology research : POR》2016,22(4):781-788
Epithelial to mesenchymal transition (EMT) is a biological process in which the epithelial cells, transform to mesenchymal cells via multiple biochemical modifications. Immunohistochemical method was used to examine the expression of EMT-related proteins: Slug, E-cadherin and fibronectin, in 41 cases of sinonasal inverted papilloma (SIP), 33 cases of sinonasal squamous cell carcinoma (SNC), and 22 cases of normal mucosa as a control. In all cases negative viral status was previously confirmed using both in situ hybridization and immunohistochemical method. The immunoexpression of Slug and fibronectin were significantly increased in the SNC group as compared to SIPs and control cases. The immunoexpresssion of Slug was also higher in SIPs as compared to controls. The immunoexpression of E-cadherin was significantly lower in SNCs group as compared with SIPs and controls, but no statistically significant difference in E-cadherin immunoexpression was noted between SIPs and control cases. There were statistically significant negative correlations between immunoexpression of Slug vs E-cadherin, E-cadherin vs fibronectin and positive correlation between Slug vs fibronectin in SNC. Statistically significant correlation between Slug and fibronectin immunoexpression in SIPs was also found. In conclusion, our findings suggest that relationships between Slug, E-cadherin and fibronectin could potentially point to EMT in the sinonasal cancer. Lack of correlation between EMT-related proteins in tested SIPs could reflect a benign nature of those cases. 相似文献