全文获取类型
收费全文 | 697篇 |
免费 | 31篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 68篇 |
妇产科学 | 33篇 |
基础医学 | 67篇 |
口腔科学 | 35篇 |
临床医学 | 75篇 |
内科学 | 133篇 |
皮肤病学 | 28篇 |
神经病学 | 30篇 |
特种医学 | 14篇 |
外科学 | 108篇 |
综合类 | 12篇 |
预防医学 | 19篇 |
眼科学 | 33篇 |
药学 | 44篇 |
中国医学 | 1篇 |
肿瘤学 | 26篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 8篇 |
2021年 | 14篇 |
2020年 | 10篇 |
2019年 | 15篇 |
2018年 | 21篇 |
2017年 | 19篇 |
2016年 | 14篇 |
2015年 | 27篇 |
2014年 | 23篇 |
2013年 | 32篇 |
2012年 | 59篇 |
2011年 | 54篇 |
2010年 | 38篇 |
2009年 | 35篇 |
2008年 | 70篇 |
2007年 | 68篇 |
2006年 | 58篇 |
2005年 | 48篇 |
2004年 | 51篇 |
2003年 | 26篇 |
2002年 | 19篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
排序方式: 共有735条查询结果,搜索用时 0 毫秒
51.
Two different UV spectrophotometric methods were developed for the determination of rofecoxib in bulk form and in pharmaceutical formulations. The first method, an UV spectrophotometric procedure, was based on the linear relationship between the rofecoxib concentration and the lambdamax amplitude at 279 nm. The second one, the first derivative spectrophotometry, was based on the linear relationship between the rofecoxib concentration and the first derivative amplitude at 228, 256 and 308 nm. Calibration curves were linear in the concentration range using peak to zero 1.5-35.0 microg x ml(-1). HPLC was carried out at 225 nm with a partisil 5 ODS (3) column and a mobile phase constituted of acetonitrile and water (50 :50 v/v). A linear range was found to be 0.05-35.0 microg x ml(-1). The developed methods were successfully applied for the assay of pharmaceutical dosage form. The statistics of the analytical data is also presented. The results obtained by first derivative spectrophotometry were compared with HPLC and no significant difference was found. 相似文献
52.
OBJECTIVE: To assess and compare various simple insulin sensitivity and beta-cell function indices in lean, hirsute, young women. DESIGN: Prospective study. SETTING: Departments of endocrinology and metabolism at a university and a state hospital. PATIENT(S): Seventy-one hirsute young women were classified as hyperandrogenemic or normoandrogenemic. MAIN OUTCOME MEASURE(S): Insulin sensitivity and beta-cell function indices derived from a single sample and an oral glucose tolerance test (OGTT). RESULT(S): Lean hyperandrogenemic hirsute women have insulin resistance and increased beta-cell function. The most sensitive indices of insulin resistance were total and 1-hour and 2-hour post-challenge insulin levels during OGTT. When a cut-off value of 3.2 or greater for homeostasis model assessment of insulin resistance (HOMA-IR) was accepted, 46% of hyperandrogenemic women and 30% of normoandrogenemic women were insulin resistant. Fasting insulin level was best correlated with the fasting insulin resistance index, HOMA-IR, and Quicky index. The HOMA-IR was best correlated with fasting insulin level and the hepatic insulin sensitivity index (ISI(HOMA)). CONCLUSION(S): Insulin levels based on OGTT are the most useful index of insulin resistance and beta-cell function index in hirsute women. The HOMA-IR may be a proposed global test for insulin resistance; it correlated well with both OGTT-derived insulin resistance and beta-cell function indices and with global insulin resistance indices derived from a single sample (such as ISI (HOMA), Quicky index, FIRI(-1), fasting Belfiore index, and glucose/insulin ratio). 相似文献
53.
OBJECTIVES: The aim of the present study was to determine the effects of aging and dementia of the Alzheimer type (DAT) on lipid peroxidation and antioxidant enzyme activities. DESIGN AND METHODS: Twenty-six patients with DAT were included in the present study. Group I: 26 patients diagnosed as DAT and studied 5 yr ago. Group II: This group consisted of the same patients as Group I at the present time. Activities of CuZn superoxide dismutase (CuZn SOD) and glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) concentrations of these 26 subjects were measured and mini mental state examination (MMSE), brief psychiatric rating scale (BPRS), Hamilton depression rating scale (HDRS) were applied. RESULTS: The results revealed that 26 dementia patients had worsened cognitive symptoms and significantly increased CuZn SOD and MDA levels and decreased GSH-Px levels after 5 yr. Significant correlation was found between age and CuZn SOD (r: +0.406, p: 0.034), and between MMSE and MDA (r: -0.411, p: 0.032). CONCLUSIONS: We can conclude that MDA, CuZn SOD, and GSH-Px were significantly affected in the patients with Alzheimer disease. The most striking finding of this study is the significant correlation between MMSE and MDA in patients with DAT. 相似文献
54.
A 55-year-old woman had convergent strabismus fixus associated with high myopia. Bilateral medial rectus recession and loop myopexy of lateral and medial rectus muscles was performed. The clinical characteristics and the possible surgical treatment modalities were discussed. This surgery seems effective on both the restoration of dislocation of the eyeball and the improvement of ocular motility. 相似文献
55.
Ochratoxin A reduces NMDA receptor subunits 2A and 2B concentrations in rat hippocampus: partial protective effect of melatonin 总被引:1,自引:0,他引:1
Ochratoxin A (OTA) is a mycotoxin produced by several fungi. Many foods can be contaminated by OTA, which is consequently found in the blood of humans and animals. It is known that OTA accumulates in the brain. The aim of this study was to investigate the effects of OTA on the brain. For this purpose, the effect of OTA on N-methyl-D-aspartate (NMDA) receptor subunits 2A (NR2A) and 2B (NR2B) in the hippocampus and the protective effect of melatonin were investigated. Three groups of eight rats were used: controls, OTA-treated rats (OTA dose 289 microg/kg per day) and OTA+melatonin-treated rats (melatonin dose 10 mg/kg per day). After four weeks of treatment, electrophoretic examinations were performed using SDS-polyacrylamide gel electrophoresis and Western blotting of hippocampal homogenates of the different groups. The concentrations of NR2A and NR2B in the OTA group were significantly lower than in the control group. The concentration of NR2B was significantly increased when melatonin was co-administered with OTA compared with OTA only. There was also a significant increase in NR2A levels when melatonin was co-administered with OTA. As a result, subchronic administration of OTA reduced hippocampal NMDA receptor subunits 2A and 2B concentrations in rats. It was thought that this alteration might affect cognitive functions because hippocampal NMDA receptors are involved in the memory and learning processes. Melatonin exhibited a partially protective effect on NR2A and NR2B against OTA. 相似文献
56.
Observational cohort study on correlates of mortality in older community‐dwelling outpatients: The value of functional assessment 下载免费PDF全文
57.
Altuntas I Kilinc I Orhan H Demirel R Koylu H Delibas N 《Human & experimental toxicology》2004,23(1):9-13
Diazinon is one of the most widely used organophosphate insecticides (OPI) in agriculture and public health programs. The aim of this study was to investigate how an OPI, diazinon, affects lipid peroxidation (LPO) and the antioxidant defense system in vitro. For this purpose, two experiments were carried out. In experiment 1, the effects of various concentrations of diazinon on LPO and the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) in erythrocytes were studied. Each diazinon concentration was incubated with a previously prepared erythrocyte samples at +4 degrees C for 0, 60 and 180 min. After incubation, the malondialdehyde (MDA) levels and the activities of SOD, GSH-Px and CAT were determined. In experiment 2, in order to determine the direct effect of diazinon on the activities of SOD, GSH-Px and CAT, the erythrocytes were haemolysed and incubated with the various concentrations of diazinon at +4 degrees C for 0, 60 and 180 min. In experiment 1, MDA levels and the activities of SOD and GSH-Px increased with increasing diazinon concentration and incubation period, but CAT activity remained unchanged. In experiment 2, SOD activity was significantly decreased, and GSH-Px activity was significantly increased. From these results, it can be concluded that in vitro administration of diazinon results in the induction of erythrocyte LPO and changes the activities of antioxidant enzymes, suggesting that reactive oxygen species may be involved in the toxic effects of diazinon. 相似文献
58.
Nilgun Karadag Serdar Beken Dilek Dilli Aysegul Zenciroglu Nurullah Okumus 《Indian journal of pediatrics》2014,81(8):803-804
Despite advances in the neonatal care, hypoxic ischemic encephalopathy in late preterm and term infants remains an important cause of morbidity and mortality. There is lack of data on the application of therapeutic hypothermia in the existence of severe skin lesions. Epidermolysis bullosa is a rare group of inherited conditions which causes blisters in skin and mucosal membranes. In this report, the authors describe a successful whole-body hypothermia treatment of severe hypoxic ischemic encephalopathy in a term newborn with dystrophic epidermolysis bullosa. They observed that therapeutic hypothermia may also be given in newborns with dystrophic epidermolysis bullosa without any complications. 相似文献
59.
Therapeutic plasma exchange for the treatment of thrombotic thrombocytopenic purpura: a retrospective multicenter study. 总被引:1,自引:0,他引:1
Fevzi Altuntas Ismet Aydogdu Sibel Kabukcu Ismail Kocyigit Kerim Cikim Ismail Sari M Ali Erkut Bulent Eser Ahmet Ozturk Emin Kaya Mustafa Cetin Ali Keskin Ali Unal 《Transfusion and apheresis science》2007,36(1):57-67
BACKGROUND: Thrombotic thrombocytopenic purpura (TTP) is a rare disease that is fatal if it is not treated. Therapeutic plasma exchange (TPE) has resulted in excellent remission and survival rates in TTP patients. MATERIAL AND METHODS: We describe our experience with 52 TTP patients treated with TPE during the past eight years (65% of the patients were females; patient median age=34 years, range: 17-73). TPE was carried out 1-1.5 times plasma volume. Fresh frozen plasma (FFP) or cryosupernatant plasma (CSP) was used as the replacement fluid. TPE was performed daily until normalization of serum LDH and recovery of the platelet count to >150 x 10(9)/dL; TPE was then slowly tapered. Clinical, laboratory data, the number of TPE, other given therapy modalities, treatment outcomes and survival rate were evaluated retrospectively. RESULTS: Overall response (OR) and complete response (CR) rates were 77% and 60%, respectively. Response was excellent in 82.8% of the patients with primary TTP among whom 74.2% were CR. Additionally, there were statistical differences in terms of CR rate between patients with primary TTP and secondary TTP (74.2% vs. 29.4%; p=0.005). OR and CR rates were 79% and 57.9% in patients on TPE alone and 75.8% and 60.6% in patients on TPE+prednisolone, respectively (p=1 and p=0.8). Additionally, there were no statistical differences in terms of OR and CR rates between patients on TPE with FFP and CSP (p=0.25 and p=0.16, respectively). The presence of fever and the number of TPE were statistically important factors influencing the probability of response in multivariate logistic regression analysis (p<0.01 and p<0.01, respectively). Additionally, in multivariate Cox's regression analysis, the probability of survival was higher in patients who were responsive to treatment compared to patients who were unresponsive (p<0.001). CONCLUSION: TPE is an effective treatment for primary TTP; however, it may be used as adjunctive therapy for secondary TTP until it is under control. The addition of steroids to TPE had no advantage compared to TPE alone. CSP as replacement fluid is not superior compared to FFP. Fever appears to be a bad prognostic indicator. Therefore, prolonged treatment with TPE may be needed in patients with fever. 相似文献
60.