全文获取类型
收费全文 | 1537597篇 |
免费 | 123014篇 |
国内免费 | 3759篇 |
专业分类
耳鼻咽喉 | 20211篇 |
儿科学 | 50582篇 |
妇产科学 | 43800篇 |
基础医学 | 217626篇 |
口腔科学 | 43825篇 |
临床医学 | 135680篇 |
内科学 | 313065篇 |
皮肤病学 | 36429篇 |
神经病学 | 127600篇 |
特种医学 | 57951篇 |
外国民族医学 | 489篇 |
外科学 | 226427篇 |
综合类 | 34008篇 |
现状与发展 | 4篇 |
一般理论 | 537篇 |
预防医学 | 123857篇 |
眼科学 | 33956篇 |
药学 | 106331篇 |
1篇 | |
中国医学 | 3952篇 |
肿瘤学 | 88039篇 |
出版年
2021年 | 13945篇 |
2019年 | 14459篇 |
2018年 | 20401篇 |
2017年 | 15515篇 |
2016年 | 16888篇 |
2015年 | 19152篇 |
2014年 | 26851篇 |
2013年 | 38828篇 |
2012年 | 53793篇 |
2011年 | 56769篇 |
2010年 | 32660篇 |
2009年 | 31039篇 |
2008年 | 51120篇 |
2007年 | 54050篇 |
2006年 | 53998篇 |
2005年 | 52820篇 |
2004年 | 50337篇 |
2003年 | 47748篇 |
2002年 | 44581篇 |
2001年 | 76095篇 |
2000年 | 77614篇 |
1999年 | 64335篇 |
1998年 | 18115篇 |
1997年 | 16363篇 |
1996年 | 16495篇 |
1995年 | 15552篇 |
1994年 | 14157篇 |
1993年 | 13296篇 |
1992年 | 47564篇 |
1991年 | 45119篇 |
1990年 | 43025篇 |
1989年 | 41066篇 |
1988年 | 37601篇 |
1987年 | 36705篇 |
1986年 | 34146篇 |
1985年 | 32499篇 |
1984年 | 24713篇 |
1983年 | 20744篇 |
1982年 | 12606篇 |
1981年 | 11179篇 |
1979年 | 21359篇 |
1978年 | 15030篇 |
1977年 | 12442篇 |
1976年 | 11668篇 |
1975年 | 12021篇 |
1974年 | 14422篇 |
1973年 | 13945篇 |
1972年 | 12977篇 |
1971年 | 11773篇 |
1970年 | 11264篇 |
排序方式: 共有10000条查询结果,搜索用时 421 毫秒
171.
W. Do T. Elzerman R. de Bree A. Rosenberg T. Forouzanfar E.M. Van Cann 《International journal of oral and maxillofacial surgery》2021,50(5):591-597
The aim of this study was to analyse the effect of body mass index (BMI), both low and high values, on the perioperative complication rate in patients with oral squamous cell carcinoma (OSCC). The medical records of 259 patients operated between 2014 and 2017 for OSCC were reviewed. Univariate and multivariate analyses were performed. Sixty of the 259 patients developed 87 complications. Low or high BMI was not associated with the perioperative complication rate. A longer operating time and increased blood loss were associated with a higher perioperative complication rate and higher Clavien–Dindo grade. Low BMI, American Society of Anesthesiologists score 2 and 3, a longer operating time, and increased blood loss were associated with a longer hospital stay. Low BMI was associated with a longer hospital stay. Neither low nor high BMI was associated with the perioperative complication rate. A longer operating time and increased blood loss were associated with a higher perioperative complication rate and higher Clavien–Dindo grade. 相似文献
172.
173.
174.
Joseph F. Levy Rahul Khairnar Alexander V. Louie Timothy N. Showalter C. Daniel Mullins Mark V. Mishra 《Practical radiation oncology》2019,9(2):e172-e179
Purpose
A hydrogel rectal spacer (HRS) is a medical device that is approved by the U.S. Food and Drug Administration to increase the separation between the prostate and rectum. We conducted a cost-effectiveness analysis of HRS use for reduction in radiation therapy (RT) toxicities in patients with prostate cancer (PC) undergoing external beam RT (EBRT).Methods and Materials
A multistate Markov model was constructed from the U.S. payer perspective to examine the cost-effectiveness of HRS in men with localized PC receiving EBRT (EBRT alone vs EBRT + HRS). The subgroups analyzed included site of HRS placement (hospital outpatient, physician office, ambulatory surgery center) and proportion of patients with good baseline erectile function (EF). Data on EF, gastrointestinal and genitourinary toxicities incidence, and potential risks associated with HRS implantation were obtained from a recently published randomized clinical trial. Health utilities and costs were derived from the literature and the 2018 Physician Fee Schedule and were discounted 3% annually. Quality-adjusted life years (QALYs) and costs were modeled for a 5-year period from receipt of RT. Probabilistic sensitivity analysis and value-based threshold analyses were conducted.Results
The per-patient 5-year incremental cost for spacers administered in a hospital outpatient setting was $3578, and the incremental effectiveness was 0.0371 QALYs. The incremental cost-effectiveness ratio was $96,440/QALY for patients with PC undergoing HRS insertion in a hospital and $39,286/QALY for patients undergoing HRS insertion in an ambulatory facility. For men with good baseline EF, the incremental cost-effectiveness ratio was $35,548/QALY and $9627/QALY in hospital outpatient and ambulatory facility settings, respectively.Conclusions
Based on the current Medicare Physician Fee Schedule, HRS is cost-effective at a willingness to pay threshold of $100,000. These results contain substantial uncertainty, suggesting more evidence is needed to refine future decision-making. 相似文献175.
176.
177.
178.
Erik de Bakker Mirthe A. M. van der Putten Martijn W. Heymans Sander W. Spiekstra Taco Waaijman Liselotte Butzelaar Vera L. Negenborn Vivian K. Beekman Erman O. Akpinar Thomas Rustemeyer Frank B. Niessen Susan Gibbs 《Experimental dermatology》2021,30(1):169-178
Unpredictable hypertrophic scarring (HS) occurs after approximately 35% of all surgical procedures and causes significant physical and psychological complaints. Parallel to the need to understanding the mechanisms underlying HS formation, a prognostic tool is needed. The objective was to determine whether (systemic) immunological differences exist between patients who develop HS and those who develop normotrophic scars (NS) and to assess whether those differences can be used to identify patients prone to developing HS. A prospective cohort study with NS and HS groups in which (a) cytokine release by peripheral blood mononuclear cells (PBMC) and (b) the irritation threshold (IT) after an irritant (sodium lauryl sulphate) patch test was evaluated. Univariate regression analysis of PBMC cytokine secretion showed that low MCP‐1, IL‐8, IL‐18 and IL‐23 levels have a strong correlation with HS (P < .010‐0.004; AUC = 0.790‐0.883). Notably, combinations of two or three cytokines (TNF‐a, MCP‐1 and IL‐23; AUC: 0.942, Nagelkerke R2: 0.727) showed an improved AUC indicating a better correlation with HS than single cytokine analysis. These combination models produce good prognostic results over a broad probability range (sensitivity: 93.8%, specificity 86.7%, accuracy 90,25% between probability 0.3 and 0.7). Furthermore, the HS group had a lower IT than the NS group and an accuracy of 68%. In conclusion, very fundamental immunological differences exist between individuals who develop HS and those who do not, whereas the cytokine assay forms the basis of a predictive prognostic test for HS formation, the less invasive, easily performed irritant skin patch test is more accessible for daily practice. 相似文献
179.
180.
Shylo R. Johnson Dennis Slate Kathleen M. Nelson Amy J. Davis Samual A. Mills John T. Forbes Kurt C. VerCauteren Amy T. Gilbert Richard B. Chipman 《Viruses》2021,13(2)
Since the 1990s, oral rabies vaccination (ORV) has been used successfully to halt the westward spread of the raccoon rabies virus (RV) variant from the eastern continental USA. Elimination of raccoon RV from the eastern USA has proven challenging across targeted raccoon (Procyon lotor) and striped skunk (Mephitis mephitis) populations impacted by raccoon RV. Field trial evaluations of the Ontario Rabies Vaccine Bait (ONRAB) were initiated to expand ORV products available to meet the rabies management goal of raccoon RV elimination. This study describes the continuation of a 2011 trial in West Virginia. Our objective was to evaluate raccoon and skunk response to ORV occurring in West Virginia for an additional two years (2012–2013) at 75 baits/km2 followed by three years (2014–2016) of evaluation at 300 baits/km2. We measured the change in rabies virus-neutralizing antibody (RVNA) seroprevalence in targeted wildlife populations by comparing levels pre- and post-ORV during each year of study. The increase in bait density from 75/km2 to 300/km2 corresponded to an increase in average post-ORV seroprevalence for raccoon and skunk populations. Raccoon population RVNA levels increased from 53% (300/565, 95% CI: 50–57%) to 82.0% (596/727, 95% CI: 79–85%) during this study, and skunk population RVNA levels increased from 11% (8/72, 95% CI: 6–20%) to 39% (51/130, 95% CI: 31–48%). The RVNA seroprevalence pre-ORV demonstrated an increasing trend across study years for both bait densities and species, indicating that multiple years of ORV may be necessary to achieve and maintain RVNA seroprevalence in target wildlife populations for the control and elimination of raccoon RV in the eastern USA. 相似文献