全文获取类型
收费全文 | 4849篇 |
免费 | 265篇 |
国内免费 | 27篇 |
学科分类
医药卫生 | 5141篇 |
出版年
2023年 | 47篇 |
2022年 | 140篇 |
2021年 | 234篇 |
2020年 | 98篇 |
2019年 | 137篇 |
2018年 | 184篇 |
2017年 | 98篇 |
2016年 | 98篇 |
2015年 | 132篇 |
2014年 | 179篇 |
2013年 | 208篇 |
2012年 | 310篇 |
2011年 | 297篇 |
2010年 | 208篇 |
2009年 | 174篇 |
2008年 | 254篇 |
2007年 | 264篇 |
2006年 | 261篇 |
2005年 | 236篇 |
2004年 | 168篇 |
2003年 | 172篇 |
2002年 | 158篇 |
2001年 | 70篇 |
2000年 | 77篇 |
1999年 | 52篇 |
1998年 | 57篇 |
1997年 | 68篇 |
1996年 | 57篇 |
1995年 | 46篇 |
1994年 | 44篇 |
1993年 | 55篇 |
1992年 | 60篇 |
1991年 | 49篇 |
1990年 | 45篇 |
1989年 | 35篇 |
1988年 | 41篇 |
1987年 | 26篇 |
1986年 | 34篇 |
1985年 | 21篇 |
1984年 | 27篇 |
1983年 | 23篇 |
1982年 | 20篇 |
1981年 | 16篇 |
1980年 | 14篇 |
1979年 | 12篇 |
1978年 | 12篇 |
1977年 | 19篇 |
1976年 | 22篇 |
1975年 | 16篇 |
1969年 | 11篇 |
排序方式: 共有5141条查询结果,搜索用时 0 毫秒
1.
2.
De Leo V; Morgante G; Lanzetta D; D'Antona D; Bertieri RS 《Human reproduction (Oxford, England)》1997,12(2):357-360
We report the results of administration of danazol after suspension of
gonadotrophin-releasing hormone analogue (GnRHa) therapy for uterine
myomas. A total of 21 women with uterine myomas was treated with 100 mg
danazol for 6 months after GnRHa therapy. Uterine volume and endocrine
status were monitored monthly by ultrasound and assay of plasma
gonadotrophins, oestradiol and progesterone. The results show a rebound of
uterine volume about 30% less than in controls at the end of danazol
therapy. Menstrual cyclicity returned after 65 +/- 3 days in 16 subjects
and five patients remained amenorrhoeic. Hormone assays confirmed renewed
ovarian function in the women whose menstrual periods returned. Bone
mineral content was substantially reduced during GnRHa treatment but
improved significantly during danazol therapy even in the women who
remained amenorrhoeic. These results show the utility of danazol in
prolonging the therapeutic effects of GnRHa. The mechanism by which danazol
inhibits rebound of uterine volume may be due to its antiprogesterone
effects on uterine myomas.
相似文献
3.
In addition to a working knowledge of general complications such as thromboembolism and infective endocarditis, optimal care of the patient with a prosthetic valve requires specific knowledge concerning the characteristics of a given patient's prosthesis. This may need to include the ability to identify the valve roentgenographically when history and records are unavailable. A 53-year-old woman with mitral stenosis secondary to rheumatic heart disease and status post a reported Bjork-Shiley mitral valve (MV) replacement 17 years prior to hospital admission was referred for evaluation of severe hemolytic anemia. Previous cinefluoroscopy in 1986 at the time of a cerebrovascular accident revealed a normally functioning caged disc prosthesis and not the tilting disc of a Bjork-Shiley prosthetic valve. The valve was not further characterized and she continued receiving warfarin therapy until May 1989 when she presented with laboratory findings showing a marked hemolytic anemia with a hemoglobin of 6.5 mg/dl and lactate dehydrogenase (LDH) value of 2100 IU. Echocardiography revealed normal valvular function without evidence of perivalvular leak. The patient was referred for further evaluation with chest roentgenogram at the time of hospital admission revealing a valve configuration characteristic of the Beall model 103/104 series that has been found to manifest progressive disc variance with a high degree of hemolytic anemia (despite normal noninvasive evaluation of MV function), disc tilting with intermittent regurgitation, and catastrophic disc embolization in extreme cases. The precise identification of valvular prosthesis in patients after valve replacement is crucial for optimal management. As in our case, the mere identification of a particular valve may necessitate certain management and therapy based on the natural history of that valve. In the absence of reliable history and/or records, the roentgenographic examination should lead to the precise identification. 相似文献
4.
5.
O S Giordano M J Pestchanker E Guerreiro J R Saad R D Enriz A M Rodríguez E A Jáuregui J Guzmán A O María G H Wendel 《Journal of medicinal chemistry》1992,35(13):2452-2458
The structural requirements for the gastric cytoprotective activity of several sesquiterpene lactones are reported. A theoretical-experimental study on the potentially active centers is carried out. The biological evaluation of reduced analogues and the simulation of the molecular interactions between these compounds and an endogenous cysteine residue suggest that the presence of a non sterically hindered Michael acceptor seems to be an essential structural requirement for the cytoprotective activity in this family of compounds. This observation suggests that cytoprotection is mediated through a Michael reaction between the sulfhydryl-containing peptides of the mucosa and Michael acceptors present in the molecules under study. This mechanism of action is in addition to and distinct from the one proposed in our previous paper, namely, that these sesquiterpenes stimulate endogenous synthesis of prostaglandins. 相似文献
6.
R A Price K Lunetta R Ness M A Charles M F Saad E Ravussin P H Bennett D J Pettitt W C Knowler 《International journal of obesity (2005)》1992,16(11):851-857
We examined distribution characteristics of the body mass index (BMI; weight/height; kg/m2) in a sample of 1128 male and 1372 female Pima Indians aged 15-65 years. We found that women had a higher mean and variance of BMI than men. From commingling analyses, we determined that the distribution of BMI could be accounted for either by a single skewed distribution or by a mixture of multiple normal components. These component distributions may be used to define provisional thresholds in selecting families for genetic studies. To ensure genetic segregation of obesity predisposing genes in Pima families will require that some members have BMIs > or = 40 kg/m2. 相似文献
7.
8.
Abdel Wahab M. Ibrahim Saad M. Al-Rajeh Upendra Mohan Chowdhary Ahmed Ammar 《Neurosurgical review》1990,13(2):103-107
There are significant variations among countries in the incidence of brain abscess. We report here 26 cases of brain abscess treated at the Neurosurgery Department of King Faisal University and Dammam Central Hospital Saudi Arabia over a six year period (1982–1988). This is 2.3% of total admissions to the two neurosurgery departments serving a population of approximately 1.2 million in the same period.Young males were most often affected (M/F ratio 3.3:1; 31% were less than 15 years old, 46% aged between 15–39 years, and 23% older than 40 years). Streptococcus was found to be the most common microorganism (38.4%). Mixed infection was seen in 15.3%, and sterile abscesses were found in 11.5% of the patients after aerobic and anaerobic cultures of the pus. Chronic otitis media and paranasal sinusitis predisposed the patients to abscess formation in 57.6% of the cases. The temporo-parietal area was the commonest site. Epilepsy was a complication in 30.7% of our patients, and the mortality rate was 15.3%. 相似文献
9.
The authors report the clinical and laboratory findings of a patient who had severe immune hemolytic anemia due to hydrochlorothiazide (HCTZ). In this case, the HCTZ antibody reacted not only with other thiazide and thiazide-like drugs, but also with a chemically unrelated diuretic, ethacrynic acid. These results indicate that HCTZ antibody activity is not restricted solely to the thiazides and imply that therapy with any of the reactive drugs would be contraindicated for this patient. The serologic screening for drug reactivity may be useful for selecting alternative therapy for patients with drug-induced immune hemolytic anemia. 相似文献
10.
S A Kandil I Spahn B Scholten Z A Saleh S M M Saad H H Coenen S M Qaim 《Applied radiation and isotopes》2007,65(5):561-568
Excitation functions were measured by the stacked-foil technique for (nat)Rb(alpha,xn)(87m,87m+g,88)Y and (nat)Sr(alpha,xn)(86,88,89)Zr reactions from their respective thresholds up to 26 MeV. The samples for irradiation were prepared by sedimentation and pellet pressing techniques. The measured data were compared with those available in the literature. From the excitation functions, integral yields of the products were calculated. The suitable energy ranges for the production of (87)Y and (88)Y via (nat)Rb(alpha,xn) processes and of (89)Zr via the (nat)Sr(alpha,xn) process are E(alpha)=26-->20 MeV, E(alpha)=26-->5 MeV and E(alpha)=20-->8.5 MeV, respectively. The respective yields amount to 8.2, 0.08 and 0.9 MBq/microA h. Production of (88)Y is feasible if a waiting time of about 2 months is allowed to let the impurities decay out. Also, (87)Y can be produced with a relatively low impurity of (88)Y. The yields of both (88)Y and (87)Y via the present routes are, however, appreciably lower than those via the (nat)Sr(p,xn) processes. There is a possibility to produce (89)Zr via the alpha-particle irradiation of (nat)Sr. The yield is rather low but would be considerably increased if enriched (86)Sr would be used as target material. The radionuclidic impurity levels in all the three products are discussed. 相似文献