全文获取类型
收费全文 | 16351篇 |
免费 | 3198篇 |
国内免费 | 272篇 |
专业分类
耳鼻咽喉 | 771篇 |
儿科学 | 506篇 |
妇产科学 | 540篇 |
基础医学 | 756篇 |
口腔科学 | 581篇 |
临床医学 | 2163篇 |
内科学 | 3641篇 |
皮肤病学 | 596篇 |
神经病学 | 1479篇 |
特种医学 | 704篇 |
外国民族医学 | 7篇 |
外科学 | 4210篇 |
综合类 | 196篇 |
现状与发展 | 2篇 |
一般理论 | 2篇 |
预防医学 | 1193篇 |
眼科学 | 475篇 |
药学 | 573篇 |
中国医学 | 42篇 |
肿瘤学 | 1384篇 |
出版年
2024年 | 79篇 |
2023年 | 547篇 |
2022年 | 247篇 |
2021年 | 503篇 |
2020年 | 872篇 |
2019年 | 383篇 |
2018年 | 877篇 |
2017年 | 767篇 |
2016年 | 948篇 |
2015年 | 872篇 |
2014年 | 1183篇 |
2013年 | 1375篇 |
2012年 | 779篇 |
2011年 | 687篇 |
2010年 | 889篇 |
2009年 | 1085篇 |
2008年 | 629篇 |
2007年 | 548篇 |
2006年 | 648篇 |
2005年 | 512篇 |
2004年 | 374篇 |
2003年 | 345篇 |
2002年 | 292篇 |
2001年 | 258篇 |
2000年 | 184篇 |
1999年 | 241篇 |
1998年 | 295篇 |
1997年 | 301篇 |
1996年 | 350篇 |
1995年 | 310篇 |
1994年 | 202篇 |
1993年 | 148篇 |
1992年 | 164篇 |
1991年 | 174篇 |
1990年 | 115篇 |
1989年 | 164篇 |
1988年 | 137篇 |
1987年 | 122篇 |
1986年 | 117篇 |
1985年 | 109篇 |
1984年 | 106篇 |
1983年 | 91篇 |
1982年 | 81篇 |
1981年 | 57篇 |
1980年 | 65篇 |
1979年 | 42篇 |
1978年 | 59篇 |
1977年 | 63篇 |
1975年 | 53篇 |
1972年 | 48篇 |
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
101.
LEE JS IM HH JUNG Y JUNG IS JANG JY CHUN YK CHO YD KIM JO CHO JY KIM YS SHIM CS & KIM BS 《Neurogastroenterology and motility》2006,18(6):493-494
Background: Recent development of extracorporeal magnetic stimulation (ECMS) which uses current‐changing magnetic fields allows the induction of electrical stimulation in the desired deep tissue. Recent study showed the sacral nerve stimulation reduces corticoanal excitability that may play a functional role in anal continence mechanisms. Preliminary study shows that ECMS of sacral nerve can modify pelvic floor function and expel rectal balloon in patients with pelvic floor dyssynergia (PFD). Aims: To evaluate the effect of ECMS compared with biofeedback therapy (BF) in patients with PFD. Methods and Materials: Thirty‐eight patients who fulfilled Rome II criteria for PFD by colon transit time and anorectal function tests, were randomly treated with 8 sessions of ECMS (2/weeks; n = 19) at prone position or BF (2/weeks; n = 19) at sitting position. Stimulation parameters were set at 50–80% of maximum intensity, 10 and 50 Hz frequency, 3 s burst length with 3 and 6 s off using arm‐typed stimulator (BioCom‐1000, Mcube Co., Korea). Symptom scores for constipation with/without anorectal function test were repeatedly measured after each treatment. Response was defined as 50% or more decreased symptom score after treatment (partial response: 30–50%, poor: <30%). Results: Fifteen patients (age 49.1 ± 13.4 years, mean ± SD; 4 men) completed 8 session of BF and 14 patients (54.5 ± 17.6 years, 3 men) completed 8 session of ECMS. Four patients of BF group discontinued treatment due to unsatisfactory therapeutic effect (n = 1) and withdrew consent (n = 3) and 5 patients of ECMS group discontinued treatment because of same reasons (n = 1, 4). Total symptom scores were significantly decreased after treatment of 8 session in both treatment groups (13.4 ± 6.6 vs. 4.3 ± 4.0 for BF, p = 0.009; 14.9 ± 5.6 vs. 3.4 ± 4.0 for ECMS, p < 0.001). Bowel movements per week were also significantly increased after treatment in both groups (median 2 vs. 7 for BF, p = 0.035; median 2 vs. 7 for ECMS, p = 0.008). Thirteen out of 15 patients showed response in BF group and 12 out of 14 showed good response in ECMS group. No adverse effects in both groups. Conclusions: ECMS is as effective as BF for the treatment of PFD. Long‐term effect of ECMS for the patients with pelvic floor dyssynergia need to be evaluated in the near future. 相似文献
102.
103.
An entomological survey was carried out during 1986 in ten provinces of Syria representative of the main natural areas of this country. 932 sandflies were caught with aspirators in domestic resting sites. Captures are analysed for each species. 相似文献
104.
Jeffrey R. Rubin MD Enrique Labadie MD Gary Anderson BS James Persky MD Jerry Goldstone MD 《Annals of vascular surgery》1988,2(2):127-132
This study evaluates the effect of blood volume and hematocrit changes on brain tissue during temporary global ischemia. Normal saline was administered intravenously to 55 gerbils to achieve hypo-, normo-, and hypervolemic hemodilution and uniform 30% hematocrit reduction. Each group had unilateral carotid artery ligation and temporary (20 minute) contralateral carotid occlusion. After ten days or death, brains were harvested, preserved in formalin, sectioned in a manner which provided adequate samples of both cortex and hippocampus, and stained with H&E and luxol fast blue. They were then examined and staged microscopically for white and gray matter infarction, edema, and neuronal injury and loss. Histologic studies were performed in a randomized and blinded manner and were classified by one of four categories: normal, minimal, moderate, and severe changes. Three of ten (30%) controls survived ten days but had severe neuronal loss, minimal cerebral edema and a minimal to moderate number of white matter strokes. Survival was best in animals treated with hypovolemic hemodilution (43%). Other rates were: normovolemic (33%), controls (30%), and hypervolemic (8.3%). The degree of brain tissue damage was markedly less in the normovolemic group. In this model, normovolemic hemodilution followed by hypovolemic hemodilution offered the best overall cerebral protection during global ischemia. 相似文献
105.
106.
Dr. A. Belluzzi MD C. Brignola MD M. Campieri MD E. P. Camporesi BS P. Gionchetti MD F. Rizzello MD C. Belloli MD G. De Simone MD S. Boschi MD M. Miglioli MD L. Barbara MD 《Digestive diseases and sciences》1994,39(12):2589-2594
Fish oil has been recently proposed as a possible effective treatment in inflammatory bowel disease (IBD); however, a lot of annoying side effects (ie, belching, halitosis, diarrhea, etc) affect patient compliance. We carried out a study of patient tolerance in a group of Crohn's disease (CD) patients with a new fish oil derivative consisting of 500-mg capsules of eicosapentaenoic-docosahexaenoic (EPA 40%-DHA 20%), a free fatty acid mixture (Purepa), and we also evaluated its incorporation into phospholipids, both in plasma and in red cell membranes. Five groups of 10 CD patients in remission received nine Purepa capsules daily in four different preparations (A: uncoated, B: coated, pH 5.5; C: coated, pH 5.5, 60 min time release; D: coated, pH 6.9) and 12 × 1-g capsules daily of a triglyceride preparation (Max-EPA, EPA 18%-DHA 10%), respectively. We coated three of the four Purepa preparations in order to delay the release of contents in an attempt to minimize the side effects. After six weeks of treatment, the group taking Purepa capsules, coated, pH 5.5, 60 min time release (group C) showed the best incorporation of EPA and DHA in red blood cell phospholipid membranes (EPA from 0.2 to 4.4%, DHA from 3.7 to 6.3%), and no side effects were registered, whereas in all other groups side effects were experienced in 50% or more of subjects. This new preparation will make it possible to treat patients for long periods. 相似文献
107.
Dr. Steven A. Curley MD Robert A. Newman PhD Thomas B. Dougherty MD PhD George M. Fuhrman MD Diana L. Stone BS Jeffrey A. Mikolajek CRNA Sal Guercio CCP Ann Guercio CCP C. Humberto Carrasco MD M. Tien Kuo PhD David C. Hohn MD 《Annals of surgical oncology》1994,1(5):389-399
Background: We performed a phase I study of a novel system of complete hepatic venous isolation and extracorporeal chemofiltration in
patients with unresectable hepatocellular carcinoma (HCC) to determine (a) whether systemic exposure to doxorubicin could
be limited after high-dose hepatic arterial infusion (HAI), and (b) the hepatic maximum tolerated dose (MTD) of doxorubicin.
Methods: Ten patients with biopsy-proven HCC were treated with 20-min HAI of doxorubicin (17 total treatments). Two patients were
treated with doxorubicin 60 mg/m2, three patients were treated at 90 mg/m2, and five patients received 120 mg/m2. A newly developed dual-balloon vena cava catheter was advanced from the femoral vein, and the balloons were inflated to
isolate and capture total hepatic venous outflow. The hepatic venous blood was pumped through extracorporeal carbon chemofilters
before return of the blood to the systemic circulation.
Results: Peak systemic doxorubicin levels were an average 85.6% lower than were peak prefilter levels (p<0.01). Because all catheters
were placed percutaneously and because the chemofiltration markedly limited systemic chemotherapy exposure, patients were
discharged 1 day after 16 of the 17 treatments. The hepatic and systemic MTD of doxorubicin in this treatment protocol was
120 mg/m2.
Conclusions: This novel system of complete hepatic venous isolation and chemofiltration limits systemic chemotherapy toxicity and will
allow use of higher doses of chemotherapeutic agents to treat HCC.
The results of this study were presented at the 46th Annual Cancer Symposium of The Society of Surgical Oncology, Los Angeles,
California, March 18–21, 1993. 相似文献
108.
M. L. Strong BS RPh L. J. Schaaf PhD M. C. Pankaskie PhD D. H. Robinson PhD 《Journal of clinical pharmacy and therapeutics》1994,19(6):361-369
Published reports regarding the stability of morphine are at variance, especially in syringes used in patient-controlled analgesia (PCA) devices. In addition to the effects of container type and vehicle, reasons for this variation include the effect of excipients temperature and light during storage. Furthermore, the literature varies regarding the mechanisms of decomposition for morphine. To our knowledge, the stability of meperidine (pethidine) stored in plastic syringes has not been reported. The purposes of this study were to investigate the stability of morphine sulphate (1 and 5 mg/ml) and meperidine hydrochloride (5 and 10 mg/ml) in plastic syringes for use in PCA devices for a duration of 12 weeks, and evaluate the influence of light (240 foot-candies), temperature (-20, 4 and 23d?C), diluent (5% dextrose or normal saline), and drug concentration on the stability of these narcotic analgesics. Samples were taken bi-weekly for solutions protected from light and weekly for solutions exposed to light. Morphine sulphate and meperidine hydrochloride concentrations were quantified using independent, stability-indicating, high performance liquid chromatographic assays. The within-day and between-day coefficients of variation for these assays were 4% over each of the concentration ranges studied. Under the conditions of this study, it is proposed that although decomposition of morphine to its main product, pseudomorphine, can be interpreted using first-order kinetics, consecutive (to form the N-oxide) and parallel mechanisms (to form apomorphine) exist. Morphine solutions were more stable in normal saline than in 5% dextrose. SheIf-life data indicate that morphine is stable for at least 6 weeks when protected from light. Exposure to light accelerates morphine decomposition two to six-fold depending on the concentration, and the shelf-life is reduced to about 1 week in some instances. Meperidine solutions in both vehicles under all conditions had shelf-lives of at least 12 weeks. No effects of light were detected and no changes in solution colour were observed. This study illustrates that patients using PCA devices must be advised about shelf-lives as well as correct storage conditions to protect solutions of these drugs from environmental factors that may alter shelf-lives. Pharmacists should also note that other formulation factors such as: antioxidants, preservations, buffers, impurities, and the source and quality of containers, may significantly alter the shelf-lives of these drugs. 相似文献
109.
110.
Lee L. Eckhardt MD Amanda L. Farley MS Esther Rodriguez MD Karen Ruwaldt BS Daniel Hammill David J. Tester BS Michael J. Ackerman MD PhD Jonathan C. Makielski MD 《Heart rhythm》2007,4(3):323-329
BACKGROUND: Loss-of-function mutations in the KCNJ2 cause approximately 50% of Andersen-Tawil Syndrome (ATS) characterized by a classic triad of periodic paralysis, ventricular arrhythmia, and dysmorphic features. Do KCNJ2 mutations occur in patients lacking this triad and lacking a family history of ATS? OBJECTIVES: The purpose of this study was to identify and characterize mutations in the KCNJ2-encoded inward rectifier potassium channel Kir2.1 from patients referred for genetic arrhythmia testing. METHODS: Mutational analysis of KCNJ2 was performed for 541 unrelated patients. The mutations were made in wild type (WT) and expressed in COS-1 cells and voltage clamped for ion currents. RESULTS: Three novel missense mutations (R67Q, R85W, and T305A) and one known mutation (T75M) were identified in 4/249 (1.6%) patients genotype-negative for other known arrhythmia genes with overall incidence 4/541 (0.74%). They had prominent U-waves, marked ventricular ectopy, and polymorphic ventricular tachycardia but no facial/skeletal abnormalities. Periodic paralysis was present in only one case. Outward current was decreased to less than 5% of WT for all mutants expressed alone. Co-expression with WT (simulating heterozygosity) caused a marked dominant negative effect for T75M and R82W, no dominant negative effect for R67Q, and a novel selective enhancement of inward rectification for T305A. CONCLUSIONS: KCNJ2 loss of function mutations were found in approximately 1% of patients referred for genetic arrhythmia testing that lacked criteria for ATS. Characterization of three new mutations identified a novel dominant negative effect selectively reducing outward current for T305A. These results extend the range of clinical phenotype and molecular phenotype associated with KCNJ2 mutations. 相似文献