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   43997篇
  免费   4832篇
  国内免费   878篇
耳鼻咽喉   309篇
儿科学   901篇
妇产科学   555篇
基础医学   3298篇
口腔科学   1543篇
临床医学   4401篇
内科学   5737篇
皮肤病学   498篇
神经病学   3338篇
特种医学   1284篇
外国民族医学   3篇
外科学   3420篇
综合类   5119篇
现状与发展   5篇
一般理论   2篇
预防医学   7773篇
眼科学   591篇
药学   3370篇
  25篇
中国医学   4469篇
肿瘤学   3066篇
  2024年   110篇
  2023年   962篇
  2022年   1103篇
  2021年   1860篇
  2020年   1839篇
  2019年   1758篇
  2018年   1751篇
  2017年   1667篇
  2016年   1534篇
  2015年   1364篇
  2014年   3200篇
  2013年   3249篇
  2012年   2668篇
  2011年   2837篇
  2010年   2156篇
  2009年   2035篇
  2008年   2286篇
  2007年   2375篇
  2006年   2121篇
  2005年   1758篇
  2004年   1445篇
  2003年   1378篇
  2002年   1072篇
  2001年   982篇
  2000年   791篇
  1999年   684篇
  1998年   490篇
  1997年   532篇
  1996年   415篇
  1995年   424篇
  1994年   390篇
  1993年   310篇
  1992年   311篇
  1991年   308篇
  1990年   229篇
  1989年   209篇
  1988年   201篇
  1987年   158篇
  1986年   124篇
  1985年   115篇
  1984年   101篇
  1983年   70篇
  1982年   65篇
  1981年   61篇
  1980年   57篇
  1979年   32篇
  1978年   30篇
  1977年   26篇
  1976年   18篇
  1975年   18篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Phenomenon: Academic health centers face significant challenges trying to improve medical education while meeting patient care needs. In response to problems with traditional forms of didactic education, many residency programs have transitioned to Academic Half Day (AHD), a curricular model in which learning is condensed into half-day blocks. In this model, trainees have protected educational time free from clinical responsibilities. However, an understanding of the impact on attending physicians and patient care when residents depart clinical sites for learning activities has not been well described. We sought to explore attending physicians’ perspectives when residents depart clinical sites to attend AHD. Approach: We performed a qualitative study with a grounded theory approach using individual semistructured interviews (December 2016–April 2017) of attending physicians who worked at inpatient and emergency department clinical sites from which residents departed to attend AHD. We used the constant comparative method, generating codes using an iterative approach and continuing sampling until saturation was reached. Major themes were identified and disagreements were resolved by consensus. Findings: Fifteen attending physicians from 6 clinical services were interviewed. Data analysis yielded 5 themes: emotional strain of workload, technology and systems challenges, patient safety and care concerns, disrupted resident learning, and the challenge to optimize resident education. Attending physicians, already working on busy services, felt frustrated and perceived having an increased workload when residents departed for AHD. They were concerned about safely entering orders in the electronic health record, impeded patient workflow, and further disruption of resident schedules already disrupted by duty hour restrictions and continuity clinic. Attending physicians described the importance of experiential learning from caring for patients and from structured didactic learning; however, the optimal balance was uncertain. Insights: We found that attending physicians experienced significant emotional strain, faced technological challenges, and were concerned about impeded workflow and patient safety when residents departed clinical sites for AHD. This is likely to be true whenever residents are pulled out of the clinical setting for any reason. Educators need to partner with hospital administrators to provide appropriate support for attending physicians when residents leave clinical sites, evaluate the effectiveness of different educational models, and determine how structured learning activities fit into the overall curriculum.  相似文献   
32.
Background: Previous genome-wide association study (GWAS) has revealed the association between MYP10 at 8p23 and MYP15 at 10q21.1 and high myopia (HM) in a French population. This study is managed to discover the connection between some single nucleotide polymorphism (located at MYP10 and MYP15) and Han Chinese HM.

Methods and Results: This case-control association study contained 1673 samples, including 869 ophthalmic patients and 804 controls. Twelve tag SNPs have been selected from the MYP10 and MYP15 loci and genotyped by SNaPshot method. Among 12 SNPs, rs4840437 and rs6989782 in TNKS gene were found significant association with HM. Carriers of rs4840437G allele and rs4840437GG genotype created a low risk of high myopia (P = .036, OR = 0.81, 95%CI = 0.71–0.93; P = .016, OR = 0.73, 95%CI = 0.56–0.96; respectively). Carriers of rs6989782T allele and rs6989782TT+CT genotype also had a decreased risk of high myopia (P = .048, OR = 0.82, 95%CI = 0.71–0.94; P = .006, OR = 0.74, 95%CI = 0.59–0.92; respectively). Other 10 SNPs displaced nonsignificant association with HM. Additionally, the risk haplotype AC and the protective haplotype GT, generated by two SNPs in TNKS, were considerably more likely to be association with HM (for AC, P = .002 and OR = 1.26; for GT, P = .027 and OR = 0.84).

Conclusions: Our results demonstrated that some heritable variants in the TNKS gene are associated with HM in the Han population. The possible functions of TNKS in the development and pathogenesis of hereditary high myopia still require further researches to identify.  相似文献   

33.
34.
35.
目的探讨PBL与CBL教学法在留学生实验诊断教学的应用效果。方法将PBL联合案例教学法(CBL)应用于临床医学本科留学生实验诊断教学,与大班传统讲授教学方法(对照组)相比较,通过问卷调查和成绩分析学习效果。结果试验组在激发学习兴趣和培养临床思维能力方面均高于对照组,理论知识的成绩和实习的成绩也是试验组优于对照组,P<0.05。结论PBL与CBL教学联合应用于实验诊断教学中能够有效提高教学质量,并受到学生的认可和喜爱。  相似文献   
36.
钟成望  郑婉婷  肖莎 《中国热带医学》2020,20(11):1104-1107
类鼻疽病是由类鼻疽伯克霍尔德菌(Burkholderia pseudomallei)感染引起的一类人畜共患病,主要流行于全球热带及亚热带地区。在我国主要流行于南部地区,疫源地为海南、广东、广西、台湾等。伴随着旅游业和贸易业的发展,我国其他非疫区出现了输入性病例。类鼻疽病的感染途径主要为经伤口、粘膜、呼吸道、消化道等,其病变可涉及机体所有器官,易造成较高的误诊率和病死率。然而我国目前类鼻疽病的流行病筛查技术存在一定的局限性,在防控方面未实行有效的疾病监测和疾病报告制度,对基层医师和民众疾病知识普及的力度不够。因此,本文旨在提高我国医务工作者对类鼻疽病的重视程度,从类鼻疽病的病原学特征、流行病学特征、临床特征、诊断与治疗、防控措施这五个方面进行详细综述。  相似文献   
37.
To improve the diagnostic accuracy of electroencephalography (EEG) criteria for nonconvulsive status epilepticus (NCSE), external validation of the recently proposed Salzburg criteria is paramount. We performed an external, retrospective, diagnostic accuracy study of the Salzburg criteria, using EEG recordings from patients with and without a clinical suspicion of having NCSE. Of the 191 EEG recordings, 12 (12%) was classified as an NCSE according to the reference standard. In the validation cohort, sensitivity was 67% and specificity was 89%. The positive predictive value was 47% and the negative predictive value was 95%. Ten patients in the control group (n = 93) were false positive, resulting in a specificity of 89.2%. The interrater agreement between the reference standards and between the scorers of the Salzburg criteria was moderate; disagreement occurred mainly in patients with an epileptic encephalopathy. The Salzburg criteria showed a lower diagnostic accuracy in our external validation study than in the original design, suggesting that they cannot replace the current practice of careful weighing of both clinical and EEG information on an individual basis.  相似文献   
38.
Sagging eyelid is considered as an outward of skin ageing and may cause medical issues. However, little is known about the factors involved in sagging eyelid. The study, which aims at determining genetic risk factors for eyelid sagging, was conducted in a cohort of 502 unrelated Caucasian women living in the Paris region. All included participants were aged between 44 and 70 years old (mean age, 57.6 years old). The severity of sagging eyelid was graded in 6 categories by a dermatologist using standardized photographs of the face. A genome wide association study adjusted on potential risk factors (including age and smoking habits) was conducted to identify genetic associations. Two single nucleotide polymorphisms in total linkage disequilibrium on chromosome 10, rs16927253 (P = 7.07 × 10‐10) and rs4746957 (P = 1.06 × 10‐8), were significantly associated with eyelid sagging severity. The rs16927253‐T and rs4746957‐A alleles showed a dominant protective effect towards eyelid sagging. These polymorphisms are located in intronic parts of the H2AFY2 gene which encodes a member of the H2A histone family and very close to the AIFM2 gene that induces apoptosis. Additionally, single nucleotide polymorphisms with a false discovery rate below 0.25 were located nearby the type XIII collagen COL13A1 gene on chromosome 10 and in the ADAMTS18 gene on chromosome 16. Several relevant genes were identified by the genome wide association study for their potential role in the sagging eyelid severity.  相似文献   
39.
BackgroundEpidermal growth factor receptor (EGFR) is frequently overexpressed in metastatic triple-negative breast cancer (mTNBC). One strategy for overcoming resistance to EGFR inhibition is concomitant inhibition of downstream signaling. The antidiabetic drug metformin inhibits both MAPK and PI3K/mTOR pathway signaling. We evaluated the combination of erlotinib and metformin in a phase 1 study of patients with mTNBC.Patients and MethodsPatients with mTNBC who had received at least one prior line of therapy for metastatic disease were eligible. Erlotinib dose was fixed at 150 mg daily. Metformin dose escalation was planned according to a 3 + 3 design. Dose-limiting toxicities (DLT) were assessed during the first 5 weeks of therapy. The primary objective was to determine the maximum tolerated dose of metformin with fixed-dose erlotinib. Secondary endpoints were response rate, stable disease rate, and progression-free survival.ResultsEight patients were enrolled. The median number of prior therapies for metastatic disease was 2.5 (range, 1-6). No DLT events were reported during the DLT assessment period. Most adverse events were grade 1/2. Grade 3 diarrhea despite maximum supportive care required dose reduction of metformin in one patient. Grade 3 rash led to study withdrawal in one patient. No grade 4 adverse events were reported. The best observed response was stable disease in 2 patients (25%). Median progression-free survival was 60 days (range, 36-61 days).ConclusionErlotinib and metformin were well tolerated in a population of pretreated mTNBC patients but did not demonstrate efficacy in this population.  相似文献   
40.
BackgroundNew antidiabetic agents (sodium-glucose cotransporter-2 inhibitor [SGLT2i] and glucagon-like peptide-1 receptor agonist [GLP-1RA]) and metabolic surgery have protective effects on metabolic syndromes.ObjectivesTo compare the changes of metabolic parameters and costs among patients with obesity and type 2 diabetes undergoing metabolic surgery and initiating new antidiabetic agents over 12 months.SettingHong Kong Hospital Authority database from 2006–2017.MethodsThis is a population-wide retrospective cohort study consisting of 2616 patients (1810 SGLT2i, 528 GLP-1RA, 278 metabolic surgery). Inverse probability treatment weighting of propensity score was applied to balance baseline covariates of patients with obesity and type 2 diabetes who underwent metabolic surgery, or initiated SGLT2i or GLP-1RA. Metabolic parameters and direct medical costs were measured and compared from baseline to 12 months in metabolic surgery, SGLT2i, and GLP-1RA groups.ResultsPatients in all 3 groups had improved metabolic parameters over a 12-month period. Patients with metabolic surgery achieved significantly better outcomes in BMI (?5.39, ?.56, ?.40 kg/m2, P < .001), % total weight loss (15.16%, 1.34%, 1.63%, P < .001), systolic (?2.21, ?.59, 1.28 mm Hg, P < .001) and diastolic (?1.16, .50, ?.13 mm Hg, P < .001) blood pressure, HbA1c (?1.80%, ?.77%, ?.80%, P < .001), triglycerides (?.64, ?.11, ?.09 mmol/L, P < .001), and estimated glomerular filtration rate (3.08, ?1.37, ?.41 mL/min/1.73m2, P < .001) after 12 months compared with patients with SGLT2i and GLP1-RA. Although the metabolic surgery group incurred the greatest direct medical costs (US$33,551, US$10,945, US$10,627, P < .001), largely due to the surgery itself and related hospitalization, the total monthly direct medical expenditure of metabolic surgery group became lower than that of SGLT2i and GLP-1RA groups at 7 months.ConclusionBeneficial weight loss and metabolic outcomes at 12 months were observed in all 3 groups, among which the metabolic surgery group showed the most remarkable effects but incurred the greatest medical costs. However, studies with a longer follow-up period are warranted to show long-term outcomes.  相似文献   
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