全文获取类型
收费全文 | 8077篇 |
免费 | 431篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 126篇 |
儿科学 | 370篇 |
妇产科学 | 47篇 |
基础医学 | 819篇 |
口腔科学 | 159篇 |
临床医学 | 628篇 |
内科学 | 1981篇 |
皮肤病学 | 109篇 |
神经病学 | 819篇 |
特种医学 | 250篇 |
外科学 | 1303篇 |
综合类 | 160篇 |
一般理论 | 1篇 |
预防医学 | 319篇 |
眼科学 | 278篇 |
药学 | 614篇 |
中国医学 | 16篇 |
肿瘤学 | 538篇 |
出版年
2023年 | 89篇 |
2022年 | 150篇 |
2021年 | 324篇 |
2020年 | 126篇 |
2019年 | 221篇 |
2018年 | 329篇 |
2017年 | 200篇 |
2016年 | 216篇 |
2015年 | 220篇 |
2014年 | 359篇 |
2013年 | 480篇 |
2012年 | 676篇 |
2011年 | 690篇 |
2010年 | 339篇 |
2009年 | 299篇 |
2008年 | 456篇 |
2007年 | 507篇 |
2006年 | 503篇 |
2005年 | 413篇 |
2004年 | 356篇 |
2003年 | 317篇 |
2002年 | 258篇 |
2001年 | 126篇 |
2000年 | 116篇 |
1999年 | 94篇 |
1998年 | 49篇 |
1997年 | 44篇 |
1996年 | 36篇 |
1995年 | 28篇 |
1994年 | 21篇 |
1993年 | 33篇 |
1992年 | 59篇 |
1991年 | 58篇 |
1990年 | 36篇 |
1989年 | 30篇 |
1988年 | 28篇 |
1987年 | 35篇 |
1986年 | 27篇 |
1985年 | 26篇 |
1984年 | 20篇 |
1983年 | 18篇 |
1982年 | 7篇 |
1981年 | 10篇 |
1980年 | 8篇 |
1979年 | 7篇 |
1978年 | 10篇 |
1975年 | 10篇 |
1973年 | 5篇 |
1972年 | 5篇 |
1967年 | 6篇 |
排序方式: 共有8537条查询结果,搜索用时 15 毫秒
941.
942.
Geevar Zachariah S. Harikrishnan M.N. Krishnan P.P. Mohanan G. Sanjay K. Venugopal K.R. Thankappan 《Indian heart journal》2013,65(3):243-249
BackgroundThere is paucity of reliable contemporary data on prevalence of coronary artery disease (CAD) and risk factors in Indians. Only a few studies on prevalence of CAD have been conducted in Kerala, a Southern Indian state. The main objective of the Cardiological Society of India Kerala Chapter Coronary Artery Disease and Its Risk Factors Prevalence Study (CSI Kerala CRP Study) was to determine the prevalence of CAD and risk factors of CAD in men and women aged 20–79 years in urban and rural settings of three geographical areas of Kerala.MethodsThe design of the study was cross-sectional population survey. We estimated the sample size based on an anticipated prevalence of 7.4% of CAD for rural and 11% for urban Kerala. The derived sample sizes for rural and urban areas were 3000 and 2400, respectively. The urban areas for sampling constituted one ward each from three municipal corporations at different parts of the state. The rural sample was drawn from two panchayats each in the same districts as the urban sample. One adult from each household in the age group of 20–59 years was selected using Kish method. All subjects between 60 and 79 years were included from each household. A detailed questionnaire was administered to assess the risk factors, history of CAD, family history, educational status, socioeconomic status, dietary habits, physical activity and treatment for CAD; anthropometric measurements, blood pressure, electrocardiogram and fasting blood levels of glucose and lipids were recorded. 相似文献
943.
Debabrata Banerjee Rachana Deb Lalit Dar Bijay R. Mirdha Sunil K. Pati Sandeep Thareja 《Scandinavian journal of gastroenterology》2013,48(3):325-331
Objective. Diarrhoeal relapses in patients with ulcerative colitis (UC) may be associated with enteric infections and its diagnosis may lessen avoidable exposure to corticosteroids and/or immunosuppressants. The purpose of this study was to assess the frequency of stool pathogens (parasitic and viral) in patients with active UC. Material and methods. This prospective cross-sectional study included 49 consecutive patients (32 M, 17 F, mean age 35.8±12 years) with active UC. Three stool samples were collected from each patient and examined for parasitic infection. Rectal biopsies were obtained during sigmoidoscopy to demonstrate cytomegalovirus (CMV) inclusion bodies and to conduct qualitative polymerase chain reaction (PCR) for CMV and herpes simplex virus (HSV) DNA detection. Results. Median duration of illness was 3.9±3.7 years and 83.7% of the patients had moderate to severe disease. The prevalence of parasitic infections in UC was 12%. The organisms isolated were Strongyloides stercoralis in 4%, Ankylostoma duodenale in 4%, Cryptosporidium in 2% and Entamoeba histolytica in 2% of the patients. The prevalence of CMV and HSV in rectal biopsies using qualitative PCR was 8% and 10%, respectively. No predictive factor was identified with CMV superinfection in patients with active UC. Conclusions. In India there is a high prevalence of parasitic and viral infections in patients with active UC. The results of the study suggest that, in tropical countries with a known high prevalence of parasitic diseases, aggressive evaluation for parasitic and viral infections should be carried out, as early identification and prompt treatment of such infections can improve the clinical course of patients with active UC. 相似文献
944.
Mrs. Rinini Sen Sila Chakrabarti Bani Sengupta Madhusnata De Ajanta Haldar Sandeep Poddar 《Hemoglobin》2013,37(4):277-280
Five hundred and thirteen unrelated subjects belonging to various tribes of West Bengal, Arunachal Pradesh and Assam in Eastern India, were screened for the presence of α-thalassemia (thal) gene deletion(s) as a possible cause of unexplained anemia (Hb <11 g/dL and/or MCH <28 pg, MCV < 78 fL). As reported earlier, β-globin gene mutant alleles were found with a frequency of up to 20% in some tribes. In the present study, α-globin gene deletion alleles were found in 18% of subjects from West Bengal, 3.9% from Arunachal Pradesh and 3.84% from Assam tribesmen. Coexistence of α- and β-globin gene abnormalities was observed in up to 18% of some tribal groups. The high inbreeding rate and lack of appropriate medical care make these populations particularly vulnerable. 相似文献
945.
946.
Hao Huang Xi Jiang Zejuan Li Yuanyuan Li Chun-Xiao Song Chunjiang He Miao Sun Ping Chen Sandeep Gurbuxani Jiapeng Wang Gia-Ming Hong Abdel G. Elkahloun Stephen Arnovitz Jinhua Wang Keith Szulwach Li Lin Craig Street Mark Wunderlich Meelad Dawlaty Mary Beth Neilly Rudolf Jaenisch Feng-Chun Yang James C. Mulloy Peng Jin Paul P. Liu Janet D. Rowley Mingjiang Xu Chuan He Jianjun Chen 《Proceedings of the National Academy of Sciences of the United States of America》2013,110(29):11994-11999
947.
Dan Zheng Sandeep Kumar Vashist Michal Marcin Dykas Surajit Saha Khalid Al-Rubeaan Edmond Lam John H.T. Luong Fwu-Shan Sheu 《Materials》2013,6(3):1011-1027
A simple procedure was developed for the fabrication of electrochemical glucose biosensors using glucose oxidase (GOx), with graphene or multi-walled carbon nanotubes (MWCNTs). Graphene and MWCNTs were dispersed in 0.25% 3-aminopropyltriethoxysilane (APTES) and drop cast on 1% KOH-pre-treated glassy carbon electrodes (GCEs). The EDC (1-ethyl-(3-dimethylaminopropyl) carbodiimide)-activated GOx was then bound covalently on the graphene- or MWCNT-modified GCE. Both the graphene- and MWCNT-based biosensors detected the entire pathophysiological range of blood glucose in humans, 1.4–27.9 mM. However, the direct electron transfer (DET) between GOx and the modified GCE’s surface was only observed for the MWCNT-based biosensor. The MWCNT-based glucose biosensor also provided over a four-fold higher current signal than its graphene counterpart. Several interfering substances, including drug metabolites, provoked negligible interference at pathological levels for both the MWCNT- and graphene-based biosensors. However, the former was more prone to interfering substances and drug metabolites at extremely pathological concentrations than its graphene counterpart. 相似文献
948.
Jillian R. Gunther Awalpreet S. Chadha Sushovan Guha Gottumukkala S. Raju Dipen M. Maru Mark F. Munsell Yan Jiang Peiying Yang Edd Felix Marilyn Clemons Geena George Mathew Pankaj K. Singh John M. Skibber Miguel A. Rodriguez-Bigas George J. Chang Cathy Eng Marc E. Delclos Christopher H. Crane Prajnan Das Sunil Krishnan 《Journal of gastrointestinal oncology.》2022,13(6):2938
BackgroundIn vivo studies demonstrate that curcumin increases radioresponse of colorectal cancers. To demonstrate efficacy in humans, we performed a randomized double-blind study of locally advanced rectal cancer (LARC) patients receiving pre-operative chemoradiation therapy (CRT) ± curcumin. We used pathologic complete response (pCR) rate as a surrogate for clinical outcome.MethodsFrom 2008–2010, LARC patients were randomized to placebo/curcumin in a 1:2 ratio. Patients received CRT [50.4 gray in 28 fractions; capecitabine (825 mg/m2 twice daily)] followed by surgery. Curcumin (4 grams orally, twice daily) or placebo was given throughout CRT and 6 weeks afterward. Toxicity was monitored weekly. Blood samples taken pre- and 1-hour post-ingestion and tissue biopsies (both collected at CRT week 2) were analyzed for pharmacokinetics. The primary outcome was surgical pCR rate.ResultsOf 22 enrolled patients, 15 received curcumin. Median age was 61 years and the majority were male (n=13; 59%). The median serum curcumin concentrations before (3.04 ng/mL; range, 1.24–18.88 ng/mL) and 1 hour after (3.32 ng/mL; range, 0.84–5.36 ng/mL) curcumin intake did not differ significantly (P=0.33). Serum curcumin concentrations both increased and decreased 1-hour post-administration (range as percentage of baseline: 8.8–258.1%). Twelve curcumin patient tissue biopsies had median curcumin concentration of 33.7 ng/mg tissue (range, 0.1–4,765.7 ng/mg). Two placebo and 1 curcumin patient achieved pCRs (P=0.18). One grade 3 toxicity (infection) was experienced.ConclusionsThe addition of curcumin to CRT did not increase pCR rates for LARC patients. The unpredictable bioavailability of curcumin contributes to continued uncertainties regarding curcumin efficacy.Trial RegistrationClinicalTrials.gov identifier: . NCT00745134相似文献
949.
Vimal Krishnan S Manoj Ravi Siju V. Abraham Babu Urumese Palatty Jayaraj Mymbilly Balakrishnan 《Indian heart journal》2021,73(3):359-361
The objective of this prospective observational study was to assess the door-to-balloon time (D2B), in acute ST-segment elevation myocardial infarction (STEMI) patients and the time factors influencing it. The following timeframes were measured during the study: ED to ECG time, ED to coronary care unit time (ED2CCU), consent time, post-consent to balloon time (POSTCONSENT2B) and D2B. Effective D2B was 54 ± 12.2 min. Of the dependent variables, D2B had a strong positive correlation (ρ = 0.903) with consent time. This study sheds light on consent time a previously unrecognized entity as a significantly influencing factor for the D2B time. 相似文献
950.
Jawaher Abdullah Alamoudi Wenkuan Li Nagsen Gautam Marco Olivera Jane Meza Sandeep Mukherjee Yazen Alnouti 《World journal of hepatology》2021,13(4):433-455
BACKGROUNDHepatobiliary diseases result in the accumulation of toxic bile acids (BA) in the liver, blood, and other tissues which may contribute to an unfavorable prognosis.AIMTo discover and validate diagnostic biomarkers of cholestatic liver diseases based on the urinary BA profile.METHODSWe analyzed urine samples by liquid chromatography-tandem mass spectrometry and compared the urinary BA profile between 300 patients with hepatobiliary diseases vs 103 healthy controls by statistical analysis. The BA profile was characterized using BA indices, which quantifies the composition, metabolism, hydrophilicity, and toxicity of the BA profile. BA indices have much lower inter- and intra-individual variability compared to absolute concentrations of BA. In addition, BA indices demonstrate high area under the receiver operating characteristic curves, and changes of BA indices are associated with the risk of having a liver disease, which demonstrates their use as diagnostic biomarkers for cholestatic liver diseases.RESULTSTotal and individual BA concentrations were higher in all patients. The percentage of secondary BA (lithocholic acid and deoxycholic acid) was significantly lower, while the percentage of primary BA (chenodeoxycholic acid, cholic acid, and hyocholic acid) was markedly higher in patients compared to controls. In addition, the percentage of taurine-amidation was higher in patients than controls. The increase in the non-12α-OH BA was more profound than 12α-OH BA (cholic acid and deoxycholic acid) causing a decrease in the 12α-OH/ non-12α-OH ratio in patients. This trend was stronger in patients with more advanced liver diseases as reflected by the model for end-stage liver disease score and the presence of hepatic decompensation. The percentage of sulfation was also higher in patients with more severe forms of liver diseases.CONCLUSIONBA indices have much lower inter- and intra-individual variability compared to absolute BA concentrations and changes of BA indices are associated with the risk of developing liver diseases. 相似文献