全文获取类型
收费全文 | 5592篇 |
免费 | 246篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 34篇 |
儿科学 | 230篇 |
妇产科学 | 76篇 |
基础医学 | 518篇 |
口腔科学 | 105篇 |
临床医学 | 414篇 |
内科学 | 1223篇 |
皮肤病学 | 179篇 |
神经病学 | 414篇 |
特种医学 | 168篇 |
外科学 | 969篇 |
综合类 | 105篇 |
预防医学 | 233篇 |
眼科学 | 280篇 |
药学 | 493篇 |
1篇 | |
中国医学 | 36篇 |
肿瘤学 | 380篇 |
出版年
2024年 | 2篇 |
2023年 | 37篇 |
2022年 | 115篇 |
2021年 | 209篇 |
2020年 | 104篇 |
2019年 | 138篇 |
2018年 | 157篇 |
2017年 | 116篇 |
2016年 | 163篇 |
2015年 | 183篇 |
2014年 | 266篇 |
2013年 | 365篇 |
2012年 | 523篇 |
2011年 | 517篇 |
2010年 | 275篇 |
2009年 | 241篇 |
2008年 | 380篇 |
2007年 | 398篇 |
2006年 | 368篇 |
2005年 | 318篇 |
2004年 | 312篇 |
2003年 | 230篇 |
2002年 | 176篇 |
2001年 | 35篇 |
2000年 | 32篇 |
1999年 | 28篇 |
1998年 | 25篇 |
1997年 | 27篇 |
1996年 | 18篇 |
1995年 | 18篇 |
1994年 | 15篇 |
1993年 | 17篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1990年 | 12篇 |
1989年 | 7篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1980年 | 1篇 |
排序方式: 共有5858条查询结果,搜索用时 15 毫秒
101.
102.
103.
Amanda F Rose Alan F Gilbertson Constance Cottrell Rajesh R Tampi 《World Journal of Psychiatry》2021,11(7):265-270
In this editorial we comment on the article by Cahn-Hidalgo D published in a recent issue of the World Journal of Psychiatry 2020; 10(1); 1-11. We focus on the importance of utilizing psychometrically valid cognitive screening tools when assessing for cognitive decline in older adults in a psychiatric outpatient setting. We compared the use of Cognivue® to use of the montreal cognitive assessment (MoCA) as a cognitive screening tool. A total of 58 patients aged 55 and over participated in this comparison study. Patients completed cognitive screening on Cognivue®, a new Food and Drug Administration-cleared computer screening device, and the MoCA. The results of patient performance using these two instruments were analyzed. Sixteen (28%) patients screened negative for cognitive impairment on both assessments. Forty-two (72%) patients screened positive on one or both of the assessments. There was 43% agreement between Cognivue® and the MoCA in identifying patients with cognitive impairment, and individual subtests were weakly correlated. The MoCA was determined to be the preferred instrument due to its high sensitivity and specificity (100% and 87%, respectively) when screening for cognitive impairment. We propose that the use of Cognivue® cognitive screening tool be closely reviewed until more research proves that the test meets the standards for reliability and validity. It is important for clinicians to remember that screeners should not be used to diagnosis patients with neurocognitive disorders; instead, they should be used to determine whether further evaluation is warranted. Additionally, misdiagnosing of neurocognitive disorders can pose unnecessary psychological and emotional harm to patients and their families and also lead to incorrect treatment and undue healthcare costs. 相似文献
104.
Ezaldeen Adhamash Rajesh Pathak Qiquan Qiao Yue Zhou Robert McTaggart 《RSC advances》2020,10(50):29910
Biochar carbon YP-50 exposed to gamma radiation at 50 kGy, 100 kGy, and 150 kGy was used as an electrode for an electric double-layer capacitor. The gamma radiation affected the pore structure and pore volume of the biochar electrodes. The optimized surface morphology, pore structure, and pore volume of the biochar with an irradiation dose of 100 kGy showed outstanding specific capacitance of 246.2 F g−1 compared to the untreated biochar (115.3 F g−1). The irradiation dose of 100 kGy exhibited higher specific power and specific energy of 0.1 kW kg−1 and 34.2 W h kg−1 respectively, with a capacity retention of above 96% after 10 000 cycles at a current density of 2 A g−1. This improvement can be attributed to the decrease in average particle size, an increase in the porosity of biochar carbon. Besides, the charge transfer resistance of supercapacitor is significantly reduced from 21.7 Ω to 7.4 Ω after treating the biochar carbon with 100 kGy gamma radiation, which implies an increase in conductivity. This gamma radiation strategy to pretreat the carbon material for improving the properties of carbon materials can be promising for the development of high-performance supercapacitors for large-scale applications.(a) Schematic of the biochar carbon YP-50 exposed to gamma radiation. (b) Cyclic Voltammetry of supercapacitor with untreated biochar and biochar treated with 50 kGy, 100 kGy, and 150 kGy gamma-radiation. 相似文献
105.
106.
Binit Sureka Yashwant Patidar Kalpana Bansal S Rajesh Nitesh Agrawal Ankur Arora 《The British journal of radiology》2015,88(1055)
Objective:
The purpose of the study was to evaluate the spectrum and incidence of intrahepatic portal vein (PV) variations on triphasic abdomen multidetector CT (MDCT) and to discuss the surgical and radiological implications.Methods:
A retrospective review of 1000 triphasic MDCT abdomen scans was performed in patients sent for various liver and other abdominal pathologies between January 2014 and August 2014. A total of 967 patients (N = 967) were included in the study. The variations in branching pattern of PV were classified according to classification used by Covey et al (Covey AM, Brody LA, Getrajdman GI, Sofocleous CT, Brown KT. Incidence, patterns, and clinical relevance of variant portal vein anatomy. AJR Am J Roentgenol 2004; 183: 1055–64) and Koç et al (Koç Z, Oğuzkurt L, Ulusan S. Portal vein variations: clinical implications and frequencies in routine abdominal CT. Diagn Interv Radiol 2007; 13: 75–80).Results:
Normal anatomy (Type I) was seen in 773 patients (79.94%) out of 967 patients in our study. Trifurcation (Type II) anomaly was seen in 66 (6.83%) of cases. Right posterior vein as first branch of main PV (Type III) anomaly was seen in 48 (4.96%) of cases. Type IV anomaly and Type V anomaly was seen in 26 (2.69%) and 13 (1.34%) cases, respectively. 19 cases showed other types of variations.Conclusion:
Variations in the hepatic PV branching patterns are commonly seen that are similar to variations in hepatic artery and biliary anatomy. Knowledge of these variations is extremely important for transplant surgeons and intervention radiologists.Advances in knowledge:
Awareness of the variations in PV branching patterns is essential for intervention radiologists and vascular surgeons and avoids major catastrophic events. 相似文献107.
108.
109.
Jyotindu Debnath Rajesh Kumar Ankit Mathur Pawan Sharma Nikhilesh Kumar Nagaraj Shridhar Ashwani Shukla Shiv Pankaj Khanna 《The Indian journal of surgery》2015,77(2):221-226
The purposes of this study were to revisit the utility of ultrasonography (USG) as a primary imaging modality in acute appendicitis (AA) and to establish the role of CT scan as a second-line/problem-solving modality. All cases of suspected AA were referred for urgent USG. USG was done with standard protocol for appendicitis. Limited computed tomographic (CT) scan [NCCT ± CECT (IV contrast only)] was done for the lower abdomen and pelvis where sonographic findings were equivocal. One hundred and twenty-one patients were referred for USG for suspected appendicitis. Eight-four patients underwent surgery for AA based on clinical as well as imaging findings, of whom 76 had appendicitis confirmed at histopathology. Three patients were misdiagnosed (3.6 %) on USG as appendicitis. Of 76 patients of appendicitis confirmed histopathologically, 63 (82.8 %) had features of appendicitis on USG and did not require any additional imaging modality. Of 121 patients, 12 (10 %) needed CT scan because of atypical features on USG. Of these 12 patients, seven had retrocecal appendicitis, and three high-up paracolic appendicitis. USG alone had sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of 81, 88, 92.6, 71.6, and 83 %, respectively. When combined with CT scan in select cases, the sensitivity, specificity, PPV, NPV, and accuracy of combined USG + CT scan were 96 % (P?=?0.0014), 89 %, 93 %, 93.5 % (P?=?0.0001), and 93 % (P?=?0.0484), respectively. Twenty-eight (23 %) patients were given alternative diagnosis on USG. Dedicated appendiceal USG should be used as a primary imaging modality in diagnosing or excluding AA. Appendiceal CT can serve as a problem-solving modality. 相似文献