全文获取类型
收费全文 | 628篇 |
免费 | 37篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 32篇 |
妇产科学 | 5篇 |
基础医学 | 59篇 |
口腔科学 | 24篇 |
临床医学 | 73篇 |
内科学 | 193篇 |
皮肤病学 | 3篇 |
神经病学 | 8篇 |
特种医学 | 75篇 |
外科学 | 44篇 |
综合类 | 20篇 |
预防医学 | 22篇 |
眼科学 | 71篇 |
药学 | 27篇 |
中国医学 | 1篇 |
肿瘤学 | 26篇 |
出版年
2023年 | 4篇 |
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 7篇 |
2019年 | 9篇 |
2018年 | 9篇 |
2017年 | 5篇 |
2016年 | 17篇 |
2015年 | 8篇 |
2014年 | 14篇 |
2013年 | 26篇 |
2012年 | 15篇 |
2011年 | 27篇 |
2010年 | 40篇 |
2009年 | 30篇 |
2008年 | 21篇 |
2007年 | 33篇 |
2006年 | 20篇 |
2005年 | 13篇 |
2004年 | 17篇 |
2003年 | 17篇 |
2002年 | 15篇 |
2001年 | 15篇 |
2000年 | 11篇 |
1999年 | 19篇 |
1998年 | 31篇 |
1997年 | 30篇 |
1996年 | 31篇 |
1995年 | 28篇 |
1994年 | 19篇 |
1993年 | 21篇 |
1992年 | 10篇 |
1991年 | 4篇 |
1990年 | 13篇 |
1989年 | 16篇 |
1988年 | 14篇 |
1987年 | 21篇 |
1986年 | 8篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1977年 | 6篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1972年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有684条查询结果,搜索用时 15 毫秒
1.
2.
3.
Myosin VIIA gene: heterogeneity of the mutations responsible for Usher syndrome type IB 总被引:8,自引:1,他引:8
Levy G; Levi-Acobas F; Blanchard S; Gerber S; Larget-Piet D; Chenal V; Liu XZ; Newton V; Steel KP; Brown SD; Munnich A; Kaplan J; Petit C; Weil D 《Human molecular genetics》1997,6(1):111-116
Usher syndrome is recognized as the most frequent cause of hereditary
deaf-blindness. Usher syndrome type I (USH1), the most severe form of the
disease, is characterized by profound congenital sensorineural deafness,
constant vestibular dysfunction, and retinitis pigmentosa of prepubertal
onset. This form is genetically heterogeneous and five loci (USH1A-E) have
been mapped thusfar. However, only the gene responsible for USH1 B (which
accounts for approximately 75% of USH1 cases) has been characterized. It
encodes a long-tailed unconventional myosin, myosin VIIA, with a predicted
2215 amino acid sequence. Primers covering the complete myosin VIIA coding
sequence as well as the 3' non coding sequence were designed, allowing
direct sequence analysis of each of the 48 coding exons and flanking splice
sites in seven patients affected by USH1. Four novel mutations were thereby
identified. The possibility should now be considered of a sequence-based
prenatal diagnosis in some of the families affected by this very severe
form of Usher syndrome.
相似文献
4.
5.
Evolutionary silencing of the human elastase I gene (ELA1) 总被引:6,自引:0,他引:6
6.
S Ladas G Arapakis H Malamou-Ladas G Palikaris A Arseni 《Journal of clinical pathology》1979,32(11):1163-1167
It was postulated that the short chain fatty acids (SCFA) produced by anaerobic bacteria might serve as microbial markers in purulent material. Eighteen pus specimens from various sources were analysed by gas-liquid chromatography (GLC), and the SCFA detected were compared with the microorganisms isolated by conventional methods. It was found that the detection of propionic, isobutyric, butyric, or isovaleric acids by direct GLC of pus specimens is strong evidence for anaerobic infection but not specific for Bacteroides fragilis. It was also shown that the presence of succinic acid in pus specimens does not necessarily indicate infection by anaerobes. It can be concluded that direct GLC of purulent material provides a rapid and reliable presumptive method for the differentiation between anaerobic and aerobic infections. 相似文献
7.
Effect of surface roughness of the titanium alloy Ti-6Al-4V on human bone marrow cell response and on protein adsorption 总被引:5,自引:0,他引:5
Deligianni DD Katsala N Ladas S Sotiropoulou D Amedee J Missirlis YF 《Biomaterials》2001,22(11):1241-1251
The effect of surface roughness of the titanium alloy Ti-6Al-4V (Ti alloy) on the short- and long-term response of human bone marrow cells in vitro and on protein adsorption was investigated. Three different values in a narrow range of surface roughness were used for the substrata (R(alpha): 0.320, 0.490 and 0.874 microm). Cell attachment, cell proliferation and differentiation (alkaline phosphatase specific activity) were determined past various incubation periods. The protein adsorption of bovine serum albumin and fibronectin, from single protein solutions, on rough and smooth Ti alloy surfaces was examined with two methods, X-ray photoelectron spectroscopy (XPS) and radiolabeling. Cell attachment and proliferation were surface roughness sensitive and increased as the roughness of Ti alloy increased. No statistically significant difference was observed in the expression of ALP activity on all three Ti alloy surfaces and culture plastic. Both methods, XPS and protein radiolabeling, showed that human serum albumin was adsorbed preferentially onto the smooth substratum. XPS technique showed that the rough substratum bound a higher amount of total protein (from culture medium supplied with 10% serum) and fibronectin (10-fold) than did the smooth one. The cell attachment may be explained by the differential adsorption of the two proteins onto smooth and rough Ti alloy surfaces. 相似文献
8.
Aravind Krishnan Joshua Hsu Jinny S. Ha Stephen R. Broderick Pali D. Shah Robert SD. Higgins Christian A. Merlo Errol L. Bush 《American journal of surgery》2021,221(4):731-736
PurposeWe aimed to assess the prognostic value of Neutrophil to Lymphocyte Ratio (NLR) on long-term outcomes and graft dysfunction after lung transplantation.MethodsWe retrospectively reviewed all patients receiving a lung transplant at our institution from 2011 to 2014. The primary exposure was elevated NLR at the time of transplant, defined by NLR>4. The primary outcomes were graft failure and three-year all-cause mortality. Multivariate logistic regression and Kaplan-Meier survival analysis were used to analyze outcomes.Results95 patients were included. 40 patients (42%) had an elevated NLR. Elevated NLR was associated with graft failure (OR: 4.7 [1.2–18.8], p = 0.02), and three-year mortality (OR: 5.4 [1.3–23.2], p = 0.03) on multivariate logistic regression. Patients with elevated NLR demonstrated significantly lower survival on Kaplan-Meier analysis (50% versus 74%, p = 0.02). The c-statistic for our multivariate model was 0.91.ConclusionElevated neutrophil to lymphocyte ratio is associated with poor long-term survival and graft failure after lung transplantation. 相似文献
9.
GA Smith SD Strausbaugh C Harbeck-Weber DM Cohen BJ Shields JD Powers 《Pediatrics》1997,100(5):825-830
OBJECTIVE: To compare the effectiveness of three new topical anesthetics that do not contain cocaine (prilocaine-phenylephrine, tetracaine-phenylephrine [tetraphen], and tetracaine-lidocaine-phenylephrine) to that of tetracaine-adrenaline-cocaine (TAC) during laceration repair in children. DESIGN: Prospective, randomized, double-blind clinical trial. SETTING: The emergency department of an urban children's hospital. PARTICIPANTS: Children 1 year of age or older with a laceration = 5 cm in length that required suturing. Intervention. A total of 240 children were randomly assigned to one of four treatment groups. OUTCOME MEASURES: Pain felt during suturing was scored by suture technicians, research assistants, parents, and patients >/= 5 years of age using a visual analogue scale (VAS). Suture technicians, research assistants, and parents also scored pain using a seven-point Likert scale. In addition, suture technicians completed an anesthetic effectiveness scale. RESULTS: There was consistently no difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. A statistically significant difference was seen among anesthetics when comparing VAS and Likert scale scores of suture technicians and Likert scale scores of research assistants. Based on post hoc analyses, these statistically significant differences were between TAC and prilocaine-phenylephrine (suture technician VAS and Likert scale) and between TAC and tetracaine-lidocaine-phenyl-ephrine (suture technician Likert scale), but not between TAC and tetraphen. When power analyses were performed using alpha = 0.05 and beta = 0.20, it was possible to detect a difference of 1.2 VAS units for each of the observer groups. Based on anesthetic effectiveness scale scores, the three new topical preparations collectively performed significantly better on the face and scalp than on the extremities (relative risk = 1.83; 95% confidence interval 1.20 < relative risk < 2.79). CONCLUSION: This study demonstrated the effectiveness and safety of three new non-cocaine-containing topical anesthetics. Consistently, there was no statistical difference demonstrated between the effectiveness of tetraphen and that of TAC for each outcome measure of each observer group. Tetraphen offers an effective alternative to TAC during laceration repair in children. 相似文献
10.
Non-typhoid Salmonella gastroenteritis 总被引:2,自引:0,他引:2