首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   6099篇
  免费   556篇
  国内免费   41篇
耳鼻咽喉   47篇
儿科学   104篇
妇产科学   296篇
基础医学   726篇
口腔科学   136篇
临床医学   681篇
内科学   1350篇
皮肤病学   73篇
神经病学   610篇
特种医学   328篇
外科学   686篇
综合类   131篇
一般理论   2篇
预防医学   362篇
眼科学   167篇
药学   352篇
中国医学   63篇
肿瘤学   582篇
  2023年   36篇
  2022年   69篇
  2021年   140篇
  2020年   82篇
  2019年   180篇
  2018年   203篇
  2017年   165篇
  2016年   185篇
  2015年   233篇
  2014年   268篇
  2013年   332篇
  2012年   436篇
  2011年   466篇
  2010年   294篇
  2009年   279篇
  2008年   328篇
  2007年   299篇
  2006年   354篇
  2005年   262篇
  2004年   263篇
  2003年   236篇
  2002年   205篇
  2001年   155篇
  2000年   143篇
  1999年   118篇
  1998年   52篇
  1997年   49篇
  1996年   38篇
  1995年   21篇
  1994年   26篇
  1993年   27篇
  1992年   73篇
  1991年   74篇
  1990年   58篇
  1989年   63篇
  1988年   38篇
  1987年   38篇
  1986年   48篇
  1985年   35篇
  1984年   30篇
  1983年   33篇
  1982年   24篇
  1981年   22篇
  1979年   20篇
  1978年   19篇
  1977年   16篇
  1975年   14篇
  1974年   30篇
  1973年   21篇
  1972年   18篇
排序方式: 共有6696条查询结果,搜索用时 31 毫秒
61.
The association between inflammatory bowel disease and colorectal cancer is well known. Although the overall incidence of inflammatory bowel disease has declined recently, patients with this disease still have a 1.7-fold increased risk of colorectal cancer. The risk factors for developing colorectal cancer include extensive colitis, young age at diagnosis, disease duration, primary sclerosing cholangitis, chronic colonic mucosal inflammation, dysplasia lesion, and post-inflammatory polyps. In patients with inflammatory bowel disease, control of chronic inflammation and surveillance colonoscopies are important for the prevention of colorectal cancer. The 2017 guidelines from the European Crohn’s and Colitis Organisation suggest that colonoscopies to screen for colorectal cancer should be performed when inflammatory bowel disease symptoms have lasted for 8 years. Current evidence supports the use of chemoprevention therapy with mesalamine to reduce the risk of colorectal cancer in patients with ulcerative colitis. Other compounds, including thiopurine, folic acid, statin, and tumor necrosis factor-α inhibitor, are controversial. Large surveillance cohort studies with longer follow-up duration are needed to evaluate the impact of drugs on colorectal cancer risks.  相似文献   
62.
The effect of type I and II diabetes in pregnancy on the circadian rhythm and diurnal excursion of plasma cortisol was studied in the second and third trimesters and post partum. Cosignor analysis demonstrated persistence during gestation of the significant circadian rhythm of the nonpregnant state. As previously reported in control pregnancies, plasma cortisol levels (24-hour mean, nadir, peak, and nadir-peak excursion) increased during gestation while the relative excursion of cortisol (expressed as the percent deviation from the 24-hour mean) was blunted. No significant difference was found between diabetic groups or when diabetic groups were compared with control subjects. Nocturnal hypoglycemia was common among diabetic women during pregnancy and post partum. Although these episodes were usually asymptomatic, the mean concomitant cortisol levels were increased over the corresponding cortisol levels of nonhypoglycemic diabetic and control subjects. We conclude that differences between control and type I and II diabetic subjects in carbohydrate tolerance or glycemic excursion are not explained by differences in cortisol levels or rhythm. The pregnancy-associated blunting of the excursion of cortisol is consistent with an autonomous source of adrenocorticotropin. Asymptomatic nocturnal hypoglycemia is common in insulin-requiring diabetic women and is associated with increased cortisol secretion.  相似文献   
63.
In this paper, comparative studies of hydrophilic and hydrophobic mesoporous silica particles (MSPs) on the dielectric properties of their derivative polyester imide (PEI) composite membranes were investigated. A series of hydrophilic and hydrophobic MSPs were synthesized with the base-catalyzed sol-gel process of TEOS, MTMS, and APTES at a distinctive feeding ratio with a non-surfactant template of D-(-)-Fructose as the pore-forming agent. Subsequently, the MSPs were blended with the diamine of APAB, followed by introducing the dianhydride of TAHQ with mechanical stirring for 24 h. The obtained viscous solution was subsequently coated onto a copper foil, 36 μm in thickness, followed by performing thermal imidization at specifically programmed heating. The dielectric constant of the prepared membranes was found to show an obvious trend: PEI containing hydrophilic MSPs > PEI > PEI containing hydrophobic MSPs. Moreover, the higher the loading of hydrophilic MSPs, the higher the value of the dielectric constant and loss tangent. On the contrary, the higher the loading of hydrophobic MSPs, the lower the value of the dielectric constant with an almost unchanged loss tangent.  相似文献   
64.
Rationale:Angle closure glaucoma (ACG) is one of the most emergent types of glaucoma in clinical practice. Laser peripheral iridotomy (LPI) could minimize pupillary block and prevent ACG from an acute attack. However, recurrent increase in intraocular pressure (IOP) may still occur despite successful LPI. The aim of this study is to highlight the importance of postLPI pilocarpine use and larger LPI size as well as to share some experiences of cataract surgery in patients with ACG.Patient concerns:A 63-year-old female was referred to our hospital for headache, and poor control of IOP in the right eye for 3 hours.Diagnoses:The patient was diagnosed ACG in the right eye. Recurrence of ACG in the right eye and new-onset and recurrent ACG in the left eye were noted during follow-up, despite successful LPI. The diagnosis was confirmed through slit lamp and gonioscope examination.Interventions:The LPI size was enlarged and pilocarpine use was maintained at 2% (1 drop 4 times a day) in both the eyes. Finally, cataract surgery was performed in both the eyes.Outcomes:No recurrence of ACG was noted during postLPI pilocarpine use in both the eyes. The postoperative IOP was stable for >6 months after cataract surgery without any surgical intervention or antiglaucoma medication use. No discomfort or major complication was observed.Conclusion:This report highlights the importance of postLPI pilocarpine use and larger LPI size in patients with refractory ACG.  相似文献   
65.
The complete picture regarding transmission modes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unknown. This review summarises the available evidence on its transmission modes, our preliminary research findings and implications for infection control policy, and outlines future research directions. Environmental contamination has been reported in hospital settings occupied by infected patients, and is higher in the first week of illness. Transmission via environmental surfaces or fomites is likely, but decontamination protocols are effective in minimising this risk. The extent of airborne transmission is also unclear. While several studies have detected SARS-CoV-2 ribonucleic acid in air samples, none has isolated viable virus in culture. Transmission likely lies on a spectrum between droplet and airborne transmission, depending on the patient, disease and environmental factors. Singapore’s current personal protective equipment and isolation protocols are sufficient to manage this risk.  相似文献   
66.
67.
Objective: This study aimed to (a) translate a hearing aid (HA) manual into Malay language and revise the translated manual based on best practice guidelines; (b) compare the effectiveness of the translated and the revised Malay HA manuals in helping individuals to perform HA management tasks.

Design: Cross-sectional, randomised, single-blinded study.

Study sample: An Oticon-Dynamo HA manual was translated and revised based on best practice guidelines. Ninety participants aged 55?years and above participated in this study. They were randomly assigned into the control group (received translated manual) and the experimental group (received the revised translated manual). The Hearing Aid Management (HAM) test, which was developed in a previous study, was conducted to evaluate participant’s ability to perform HA management tasks using the translated and the revised version of Malay HA manual.

Results: The revised Malay HA manual had a lower reading grade level relative to the initial translated Malay HA manual. The ability to perform HA management tasks was better in the experimental group (mean = 12.2, SD = 1.15) versus the control group (mean = 8.7, SD = 2.11).

Conclusion: Further revision of existing HA manuals based on best practice guidelines is recommended to help individuals better manage their HAs.  相似文献   
68.
69.
70.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号