全文获取类型
收费全文 | 1402篇 |
免费 | 161篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 34篇 |
妇产科学 | 40篇 |
基础医学 | 305篇 |
口腔科学 | 27篇 |
临床医学 | 127篇 |
内科学 | 250篇 |
皮肤病学 | 4篇 |
神经病学 | 182篇 |
特种医学 | 14篇 |
外科学 | 230篇 |
综合类 | 14篇 |
一般理论 | 3篇 |
预防医学 | 74篇 |
眼科学 | 28篇 |
药学 | 118篇 |
中国医学 | 1篇 |
肿瘤学 | 95篇 |
出版年
2023年 | 8篇 |
2022年 | 13篇 |
2021年 | 39篇 |
2020年 | 26篇 |
2019年 | 27篇 |
2018年 | 28篇 |
2017年 | 25篇 |
2016年 | 19篇 |
2015年 | 28篇 |
2014年 | 23篇 |
2013年 | 34篇 |
2012年 | 78篇 |
2011年 | 81篇 |
2010年 | 42篇 |
2009年 | 39篇 |
2008年 | 77篇 |
2007年 | 72篇 |
2006年 | 77篇 |
2005年 | 61篇 |
2004年 | 54篇 |
2003年 | 59篇 |
2002年 | 57篇 |
2001年 | 52篇 |
2000年 | 56篇 |
1999年 | 45篇 |
1998年 | 19篇 |
1997年 | 15篇 |
1996年 | 11篇 |
1995年 | 8篇 |
1994年 | 15篇 |
1993年 | 14篇 |
1992年 | 25篇 |
1991年 | 25篇 |
1990年 | 36篇 |
1989年 | 24篇 |
1988年 | 16篇 |
1987年 | 18篇 |
1986年 | 19篇 |
1985年 | 28篇 |
1984年 | 13篇 |
1983年 | 16篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1980年 | 6篇 |
1979年 | 21篇 |
1978年 | 11篇 |
1977年 | 13篇 |
1976年 | 15篇 |
1975年 | 11篇 |
1974年 | 17篇 |
排序方式: 共有1564条查询结果,搜索用时 527 毫秒
81.
Allogeneic red blood cell transfusion is an independent risk factor for the development of postoperative bacterial infection 总被引:6,自引:0,他引:6
BACKGROUND AND OBJECTIVES: Allogeneic red blood cell transfusions may exert immunomodulatory effects in recipients including an increased rate of postoperative bacterial infection. It is controversial whether allogeneic transfusion is an independent predictor for the development of postoperative bacterial infection. METHODS: We analysed a prospectively collected database of 1,349 patients undergoing colorectal surgery in 11 centres across Canada. The primary outcome was the development of either a postoperative wound infection or intra-abdominal sepsis in transfused and nontransfused patients. The effect of allogeneic transfusion on postoperative infection was evaluated with adjustment for all the confounding factors in a multiple regression analysis. RESULTS: The 282 patients who received a total of 832 allogeneic units had a significantly higher frequency of wound infections and intra-abdominal sepsis than the patients who were not transfused (25. 9 vs. 14.2%, p = 0.001). A significant dose-response relationship between transfusion and infection rate was demonstrated. Multiple regression analysis identified allogeneic transfusion as a statistically significant independent predictor for postoperative bacterial infection (OR 1.18, 95% CI 1.05-1.33, p = 0.007). Other independent predictors were anastomotic leak, repeat operation, patient age and preoperative haemoglobin level. The mortality rate was also significantly higher in the transfused group. CONCLUSION: These data support the hypothesis that allogeneic red cell transfusion is an independent risk factor for the development of postoperative bacterial infection in patients undergoing colorectal surgery. This association provides further reason to minimise exposure to allogeneic transfusions in the perioperative setting. 相似文献
82.
In previous research adapted versions of the Short Michigan Alcoholism Screening Test (SMAST) have been employed to assess an individual's father's (F-SMAST) and mother's alcohol abuse (M-SMAST). However, to date psychometric information on these forms has been limited. In order to more broadly assess the psychometric properties of these forms, several critical issues in five related studies were addressed. The samples for the five studies were drawn from a college population at a large midwestern university. Overall, the reliability and validity of the adapted SMASTs appears to be quite good. The F-SMAST demonstrated high reliability (from the standpoint of internal consistency, temporal stability, and reliability across siblings) as well as validity (both in respect to convergence with an interview measure and with father's own report on a parallel instrument). Furthermore, shortening both of these instruments to nine-item versions appears to improve their reliability and validity. For researchers and clinicians interested in assessing parental history of alcoholism, the F-SMAST and M-SMAST would appear to be a reliable and valid paper-and-pencil measure. 相似文献
83.
Successful treatment of murine muscular dystrophy with the proteinase inhibitor leupeptin. 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
J H Sher A Stracher S A Shafiq J Hardy-Stashin 《Proceedings of the National Academy of Sciences of the United States of America》1981,78(12):7742-7744
Mice with genetic muscular dystrophy were treated with intraperitoneal injections of the proteinase inhibitor leupeptin, beginning before the onset of weakness. A significant number of the treated animals failed to develop histological evidence of dystrophy, compared with controls. Leupeptin treatment prevented (or delayed) the onset of muscular dystrophy in this experiment. 相似文献
84.
A case of violent anaphylaxis apparently due to penicillin "hidden" in a frozen dinner is described. Steps helpful in investigating such cases are briefly discussed. 相似文献
85.
86.
Jabbour N Gagandeep S Mateo R Sher L Genyk Y Selby R 《Journal of the American College of Surgeons》2005,201(3):412-417
BACKGROUND: Despite the risks associated with transfusion, the medical community continues to view blood as a safe and abundant product. In this article, we provide an effective strategy to accomplish orthotopic liver transplantation without transfusion. STUDY DESIGN: From June 1999 through July 2004, 27 liver transplantations were performed in Jehovah's Witness patients at the USC-University Hospital (24 adults, 3 children). Nineteen of these were living donor (LD) and eight were deceased donor (DD) liver transplants. Preoperative blood augmentation with erythropoietin and iron was achieved. At induction, all LD and six of eight DD recipients underwent acute normovolemic hemodilution (ANH), and the operation was conducted under conditions of moderate anemia. Cell scavenging techniques were used. Acute normovolemic hemodilution and salvaged blood were returned as needed during bleeding or on completion of transplantation. RESULTS: The preoperative liver disease severity score was higher in the deceased donor group. We had 100% graft and patient survivals in the LD group, and 75% in the DD recipients. Two DD recipients died. The remaining are all alive and well, with a mean followup of 965 days (range 266 to 1,979 days) in the LD group and 624 days (range 119 to 1,132 days) in the DD group. CONCLUSIONS: Preoperative blood augmentation and acute normovolemic hemodilution provide a safe cushion against operative blood loss. Elective living donor liver transplantation allows full implementation of a transfusion-free strategy in the setting of early hepatic failure, portal hypertension, and anemia. This feat is an important step toward global standardization of transfusion-free surgical practice and an important response to widespread blood shortages and transfusion risks. 相似文献
87.
Sentinel node biopsy is being increasingly used as a staging tool for mucosal head and neck cancer. This review of the literature summarizes the results of research into the procedure when it has been performed in three main contexts: as part of an ipsilateral neck dissection, as a stand-alone procedure to stage the neck for positive or negative disease, and as a means of investigating the non-involved or contralateral neck in tumors close to or crossing the midline. The role of the procedure is discussed and the difficulties encountered are expanded, with a particular emphasis on pitfalls of the technique, caveats, and its potential role for the future. 相似文献
88.
BACKGROUND: Application specifications for ISBT 128 bar code symbology and the International Council for Commonality in Blood Bank Automation (ICCBBA) were created in 1994. By June 2000, the FDA considered ISBT 128 a standard for uniform labeling of blood and blood components. Our blood center initiated a change process for ISBT 128 implementation and "went live" in 2003. STUDY DESIGN AND METHODS: The intention to adopt ISBT 128 symbology with hospitals was actively communicated in October 2001. A Codabar-ISBT label cross-reference book was developed, FDA approval for the fullface label format in April 2002 was requested, and FDA approval was received in March 2003. In December 2002, donor identification labels and number sets were ordered, and an integration test plan was subsequently developed with departmental process flowcharts for each of the nine affected departments. Each step was tested, the labeling changes were approved in May 2003, training was completed in June 2003, and ISBT bar code symbology was implemented on July 1, 2003. A written survey was sent to hospital transfusion services in April 2004. RESULTS: Implementation went smoothly except for an unanticipated high rate of "no-reads" on some analyzers in the testing lab. The hospitals spent an average of 18 hours preparing for changes, 14 hours on validation, 4 hours on documentation and procedure development, and 8 hours on training. CONCLUSION: ISBT bar code symbology was successfully implemented. Hospital transfusion services made some adjustments and, overall, readily accepted the new bar code symbology. 相似文献
89.
Huang CY Yang HM Sher YJ Lin YH Wu JL 《International journal of pediatric otorhinolaryngology》2005,69(4):505-511
OBJECTIVE: Speech intelligibility, the extent to which the speakers can be understood verbally by their listeners, is an evaluator for the effectiveness of cochlear implantation. Thus, our goals were to evaluate the result of a tonal language through comparing the speech intelligibility between normal-hearing and implanted children who speak Mandarin, and to evaluate the relationship between speech intelligibility and duration of implants use. The effects of the age at implantation were also evaluated. METHODS: Twenty-six children (mean age of 5.9 years), who were congenitally deaf and implanted age at 3.5 years, were compared with 26 normal-hearing children (mean age of 5.84 years). The average post-implanted time was more than 6 months. Speech intelligibility was represented with the speech intelligibility ratings (SIR) and the correct percentage of dictation. The relationships between speech intelligibility, age at implantation and duration of implant were evaluated by linear regression analysis. RESULTS: Speech intelligibility of most subjects ranked from SIR category 3-5. The average correct perception rate (CI group/normal group) of words, consonants, vowels, and tones were 42.5%, 64.9%, 73.5%, and 72.3%, respectively. These differences were statistically significant (p<0.001). Speech intelligibility was positively correlated with age only in the normal-hearing group. Speech intelligibility in the implanted group was negatively correlated with age at implantation but positively correlated with the duration of implant. CONCLUSIONS: Speech intelligibility of tonal language was poorer in implanted children than normal-hearing children, but their communication outcomes were satisfactory when measured with SIR. Speech intelligibility is better if the age at implantation is younger or duration of implants use is longer. 相似文献
90.
Effects of caregivers' perceived stigma and causal beliefs on patients' adherence to antidepressant treatment 总被引:1,自引:0,他引:1
OBJECTIVE: Nonadherence to prescribed medications is a significant problem in the treatment of mood disorders. Previously proposed adherence models have not been sufficiently accurate in identifying patients who do not adhere to treatment. This study evaluated the importance of the social context in adherence by using a prospective, longitudinal analysis. Specifically, this study evaluated the effects of caregivers' causal beliefs about depression and their perceptions of stigma on three-month treatment adherence among patients with depression. METHODS: Fifty patients with major depressive disorder and their primary caregivers were identified at a psychiatric hospital's outpatient clinic. Attributions for the causes of depression (either cognitive and attitudinal or medical and biological) and perceived stigma were assessed among caregivers at baseline, and patients' adherence was evaluated three-months after treatment began. RESULTS: Data were available for 47 patients at follow-up. Caregivers' attribution of depression to cognitive and attitudinal problems significantly predicted patients' decreased adherence. However, the degree of patients' adherence was not predicted by caregivers' attributions to medical and biological causes and caregivers' perceived stigma. CONCLUSIONS: The findings stress the importance of patients' social environment in determining treatment adherence and the necessity of educating caregivers about the impact that their causal attributions have on patients' behavior. Involving caregivers in treatment may improve their attitude toward patients with depression and, in doing so, enhance patients' adherence and outcome. 相似文献