全文获取类型
收费全文 | 1893篇 |
免费 | 51篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 112篇 |
妇产科学 | 112篇 |
基础医学 | 129篇 |
口腔科学 | 96篇 |
临床医学 | 104篇 |
内科学 | 449篇 |
皮肤病学 | 38篇 |
神经病学 | 144篇 |
特种医学 | 62篇 |
外科学 | 423篇 |
综合类 | 10篇 |
预防医学 | 28篇 |
眼科学 | 77篇 |
药学 | 131篇 |
中国医学 | 2篇 |
肿瘤学 | 34篇 |
出版年
2023年 | 4篇 |
2022年 | 18篇 |
2021年 | 39篇 |
2020年 | 26篇 |
2019年 | 31篇 |
2018年 | 40篇 |
2017年 | 30篇 |
2016年 | 33篇 |
2015年 | 52篇 |
2014年 | 52篇 |
2013年 | 90篇 |
2012年 | 97篇 |
2011年 | 113篇 |
2010年 | 74篇 |
2009年 | 100篇 |
2008年 | 122篇 |
2007年 | 168篇 |
2006年 | 150篇 |
2005年 | 155篇 |
2004年 | 124篇 |
2003年 | 120篇 |
2002年 | 109篇 |
2001年 | 23篇 |
2000年 | 36篇 |
1999年 | 23篇 |
1998年 | 8篇 |
1997年 | 10篇 |
1996年 | 14篇 |
1995年 | 14篇 |
1994年 | 4篇 |
1993年 | 6篇 |
1992年 | 13篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1989年 | 5篇 |
1988年 | 9篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 6篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1970年 | 1篇 |
排序方式: 共有1957条查询结果,搜索用时 15 毫秒
11.
A microcapsule form of nitrofurantoin was prepared by a simple coacervation method with carboxymethylcellulose and aluminium sulfate. 33 factorial design was performed for three independent variables, namely, the particle size of the drug, the size of the microcapsules and the pH of the dissolution medium. The dissolution tests with the formulated microcapsules were carried out according to the United States Pharmacopeia XXII rotating basket method at pH 1.2, 5 and 7.5, which represent the pH of gastrointestinal fluids. Release data were examined kinetically and the ideal kinetic models were estimated and t
63.2 values obtained from RRSBW distribution were used in the factorial design experiment. The influence of the independent variables on the dissolution of nitrofurantoin microcapsules could be expressed as the pH of the dissolution medium > particle size of the microcapsule > particle size of nitrofurantoin. The other aim of this study was to evaluate microcapsule formulation in terms of the United States Pharmacopeia criteria with a minimum of experiments. Our findings suggest that dosage forms which comply with the pharmacopoeia criteria for dissolution can be prepared and selected by factorial design. 相似文献
12.
Lipid peroxidation, erythrocyte superoxide-dismutase activity and trace metals in young male footballers 总被引:6,自引:0,他引:6
Metin G Atukeren P Alturfan AA Gulyasar T Kaya M Gumustas MK 《Yonsei medical journal》2003,44(6):979-986
Physical training is known to induce oxidative stress in individuals subjected to intense exercise. In this study, we investigated plasma malondialdehyde (MDA) levels and erythrocyte superoxide dismutase (SOD) activity of 25 young male footballers and a control group of similar age. Red blood cell (RBC) count, haemoglobin (Hb) and haematocrit (Hct) values, and copper (Cu) and zinc (Zn) levels were also examined. The maximal oxygen uptake (VO2max) of all subjects was determined in order to establish their functional capacity. The main finding of the present study was that plasma MDA levels, one of the most commonly used markers of lipid peroxidation, of this group of footballers aged under 21 decreased slightly when compared with those of the control group (p < 0.001). In contrast, erythrocyte SOD activity was higher in the footballer group than in the controls (p < 0.001). Footballers who are under regular training showed an improved antioxidant activity in comparison to sedentary controls. Plasma copper concentration, RBC count and Hb concentration of the footballer group were all significantly lower than those of the control group, (p < 0.001, p < 0.01, p < 0.01, respectively). Investigating the footballers' data with Spearman's correlation analyses, the correlation coefficients (r) between Zn/Cu ratio and SOD was positive (r=0.44; p < 0.05); and between VO2max and SOD (r=0.42; p < 0.05) were both positive. On the basis of statistical analysis, we suggest that regular exercise may be beneficial in cases of oxidative damage by reducing the amount of lipid peroxidation and increasing the activity of the antioxidant enzyme SOD. 相似文献
13.
Rauch A Beese M Mayatepek E Dörr HG Wenzel D Reis A Trautmann U 《American journal of medical genetics. Part A》2003,(1):1-8
We observed a novel 3.5 Mb 5q subtelomeric deletion in a 3-year-old girl with developmental delay, hypotonia and multiple minor anomalies. Comparison of her phenotype with the few published patients with terminal 5q35 deletions revealed several overlapping features, but also showed remarkable differences such as shortness of stature versus macrosomia. After the report of 5q35.3 microdeletions in Sotos syndrome we integrated the published BACs into the public draft sequence and exactly mapped the deletion size in our patient by FISH analysis with 15 BAC probes. We demonstrated that the deletion in our patient is immediately adjacent to the reported Sotos syndrome deletion site. Subtracting the symptoms of Sotos syndrome from the published patients with larger 5q35.3 deletions allowed us to delineate a distinct phenotype of prenatal lymphedema with increased nuchal translucency, pronounced muscular hypotonia and delay of reaching motor milestones, but speech development within normal limits, wide fontanels, failure to thrive with postnatal short stature, and multiple minor anomalies such as mildly bell-shaped chest, minor congenital heart disease, and a distinct facial gestalt, associated with the novel 3.5 Mb cryptic deletion. We further showed in our patient that the deletion of the LCT(4) synthase gene results in a reduction of cysteinyl leukotriene synthesis to about 65% compared to normal values. The prenatal nuchal lymphedema associated with this deletion syndrome my be related to the deletion of the FLT4 gene causing autosomal dominant primary lymphedema and contributes to the differential diagnosis of increased fetal nuchal translucency. 相似文献
14.
Sir, The article by Kwee et al. (2004) on the intercycle variabilityof ovarian reserve tests contains important methodological pointsthat require further explanation and clarification before validconclusions can be drawn.
- The authors mention that cycle day2 or 3 serum FSH values weredetermined as basal values duringclomiphene citrate challengetest (CCCT). It has been reportedthat there is considerablevariation in serum FSH levels between 相似文献
15.
From leaves of JUNIPERUS DRUPACEA Amentoflavone, Cupressoflavone, Hinokiflavone, Quercitrin und Umbelliferone have been identified. 相似文献
16.
Koray Başdelioğlu 《The Journal of foot and ankle surgery》2021,60(1):51-54
Many people with heel pain in the general population are often diagnosed with plantar calcaneal spurs (PCS). The aim of this study was to evaluate the radiological and demographic characteristics of PCS patients and to compare the differences with the control group. In 2018, 420 patients with weightbearing lateral ankle X-ray images were included in the study. The patients were divided into 2 groups as PCS group and control group. Groups were compared age and age group (20-29, 30-39, 40-49, 50-59, 60-69, 70 and over) weight, height, body mass index (<25, 25-30, >30), chronic diseases as demographically and were also compared radiologically as calcaneal inclination angle (CIA), lateral talocalcaneal angle (LTCA), Bohler angle and Gissane angle. A statistically significant relationship was found between gender and PCS. Plantar calcaneal spur is more common in females than in males (X2:8.101, p < .03). PCS was less common in patients with BMI <25 and 25-29.9, whereas PCS is more common in patients with BMI >30 (X2:7.698, p < .021). Although the CIA angle was within normal limits in both groups, it was significantly lower in patients with PCS than in the control group(p < .05). There was no statistically significant difference between the 2 groups in terms of age, chronic disease, LTCA, Bohler angle, Gissane angle. Female gender and obesity are among the risk factors for PCS formation. CIA may have an important role in PCS formation. In order to clarify the etiology and pathophysiology of PCS, further studies with radiological features are needed. 相似文献
17.
F. Yesim K. Demirci Reyhan Kü?ükkaya Koray Akar?ay Nur Kir Tanju Atamer 《International ophthalmology》1999,23(3):181-181
Corrigendum
Corrigendum 相似文献18.
19.
Purpose: The aims of the present prospective study were to apply a new simplification for Laparoscopic Burch Colposuspension and to
assess the postoperative results of this treatment modality for stress urinary incontinence.Materials and methods: Twenty-four patients underwent simplified laparoscopic procedure via two ports, utilising endoscopic tacker and two stripes
of prolene mesh. Patients were evaluated for operative time,duration of urethral catheter, length of hospital stay, complications
and continence status.Results: The technique was successful in 21 patients after 24 months follow-up. Average operative time was 39 minutes. The lengths
of urethral catheterisation and hospital stay were 22 and 45 hours, respectively. One operative complication and three postoperative
recurrences were recorded.Conclusion: Laparoscopic bladder neck suspension continues to develop as the instruments and techniques are improved. In carefully evaluated
patients, it provides safe and minimally invasive procedure. We report the results of a new technique to simplify and speed
up a laparoscopic extraperitoneal colposuspension.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
20.
On the first day after an uneventful emergence caesarean section a 36-year-old woman developed circulatory collapse requiring cardiopulmonary resuscitation for 15 minutes. After resuscitation the patient remained haemodynamically unstable and was clinically highly suspected to suffer from fulminant pulmonary embolism. In this situation the physicians caring for the patient decided to perform a surgical pulmonary embolectomy without previous diagnostic workup. Massive emboli were removed from both pulmonary arteries. Postoperatively the patient recovered and was transferred to a rehabilitation center without severe cerebral sequelae. 相似文献