全文获取类型
收费全文 | 2804篇 |
免费 | 150篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 114篇 |
妇产科学 | 97篇 |
基础医学 | 319篇 |
口腔科学 | 271篇 |
临床医学 | 223篇 |
内科学 | 549篇 |
皮肤病学 | 63篇 |
神经病学 | 171篇 |
特种医学 | 182篇 |
外科学 | 322篇 |
综合类 | 43篇 |
预防医学 | 266篇 |
眼科学 | 11篇 |
药学 | 194篇 |
中国医学 | 24篇 |
肿瘤学 | 107篇 |
出版年
2023年 | 18篇 |
2022年 | 35篇 |
2021年 | 86篇 |
2020年 | 55篇 |
2019年 | 83篇 |
2018年 | 94篇 |
2017年 | 62篇 |
2016年 | 64篇 |
2015年 | 99篇 |
2014年 | 113篇 |
2013年 | 141篇 |
2012年 | 175篇 |
2011年 | 187篇 |
2010年 | 131篇 |
2009年 | 111篇 |
2008年 | 132篇 |
2007年 | 142篇 |
2006年 | 124篇 |
2005年 | 100篇 |
2004年 | 73篇 |
2003年 | 75篇 |
2002年 | 85篇 |
2001年 | 46篇 |
2000年 | 53篇 |
1999年 | 49篇 |
1998年 | 58篇 |
1997年 | 51篇 |
1996年 | 51篇 |
1995年 | 25篇 |
1994年 | 41篇 |
1993年 | 32篇 |
1992年 | 40篇 |
1991年 | 26篇 |
1990年 | 29篇 |
1989年 | 34篇 |
1988年 | 25篇 |
1987年 | 38篇 |
1986年 | 25篇 |
1985年 | 15篇 |
1984年 | 16篇 |
1983年 | 14篇 |
1982年 | 15篇 |
1981年 | 12篇 |
1980年 | 14篇 |
1977年 | 16篇 |
1976年 | 10篇 |
1975年 | 10篇 |
1970年 | 8篇 |
1967年 | 4篇 |
1964年 | 5篇 |
排序方式: 共有2979条查询结果,搜索用时 15 毫秒
11.
N. Zamberlan R. Castello D. Gatti M. Rossini V. Braga E. Fracassi Prof. S. Adami 《Osteoporosis international》1997,7(2):133-137
Treatment with gonadotropin-releasing hormone (GnRH) agonist leads to enhanced bone turnover and accelerated bone loss in premenopausal women with endometriosis, uterine leiomyomatomas and hirsutism. Sodium etidronate is a powerful inhibitor of bone resorption which has been proven efficacious in the prevention and treatment of postmenopausal osteoporosis. The objective of this study was to evaluate the skeletal effects of 6 months of therapy with the depot preparation of the GnRH agonist triptorelin (decapeptil 3.75 mg intramuscularly every 4 weeks) in 24 hirsute patients, aged 24–33 years, with hyperandrogenic chronic anovulation. Ten patients also received cyclical etidronate in an oral dose of 400 mg/day for 2 weeks, followed by an 11-week period of 500 mg/day elemental oral calcium (one cycle). The remaining 14 patients received 500 mg/day of elemental calcium continuously. After 6 months all treatments were discontinued for at least a further 6 months. Bone mineral density (BMD) at lumbar spine and hip (dual-energy X-ray absorptiometry, Sophos LXRA, France) and biochemical markers (serum alkaline phosphatase, osteocalcin, urinary N-telopeptide and hydroxyproline/creatinine ratio) were evaluated at baseline, 6 months and 12 months. In the group given GnRH agonist alone BMD fell significantly at all measured skeletal sites during the first 6 months. In the patients treated with etidronate a significant decrease in BMD was observed at lumbar spine but not in the femoral neck and trochanter, and the changes at lumbar spine and trochanter were significantly smaller than those in the control group. At 6 months bone turnover was also increased in patients treated with GnRH and calcium. Cyclical etidronate prevented the increase in biochemical markers of bone formation and resorption, with the exception of calcium/creatinine excretion, which was significantly increased in both groups. Six months after treatment withdrawal BMD did not recover in either group. Biochemical markers (N-telopeptide, serum alkaline phosphatase) remained increased in those patients previously treated with calcium alone while they remained close to baseline values in the patients treated with cyclical etidronate.Our study indicates that: (1) GnRH agonist therapy causes remarkable bone loss in young individuals with androgen excess who are expected to have increased bone mass; (2) this bone loss can be partially prevented by intermittent cyclical etidronate therapy. 相似文献
12.
13.
GP SCHWAB AL BLUM E BODNER B DALLEMAGNE K GLASER H KOOP F PACE W RÖSCH JR SIEWERT G WETSCHER 《Journal of gastroenterology and hepatology》1997,12(12):785-789
Gastroesophageal reflux disease (GERD) is the most common disease of the upper gastrointestinal tract. With the introduction of proton pump inhibitors medical treatment of GERD has been significantly improved. However, the development of laparoscopic antireflux surgery resulted in an increasing interest of surgeons in this disease. An interactive meeting was organized in order to develop an agreement between gastoenterologists and surgeons regarding therapeutic decisions and this is the main topic of this paper. 相似文献
14.
Davide Gatti Francesca Colapietro Elena Fracassi Elisabetta Sartori Franco Antoniazzi Vania Braga Maurizio Rossini Silvano Adami 《Journal of clinical densitometry》2003,6(2):173-177
In patients with osteogenesis imperfecta (OI), a disease characterized by abnormal bone fragility, bone mineral density (BMD) was found to be relatively preserved. Quantitative computed tomography (QCT) is the only available method for directly measuring in vivo both volumetric density and the cross-sectional area. Here we report the data from dual-energy X-ray absorptiometry DXA (spine and hip) and peripheral (pQCT) (ultradistal and proximal radius) measurement of 27 adult patients affected by OI, mostly of type I, compared with a group of healthy persons. In the patients with OI, areal BMD values at both femoral neck and lumbar spine were considerably lower than in control subjects (-32 and -36%, respectively; p<0.001 for body weight and height adjusted values). pQCT volumetric density at the ultradistal radius was 19% lower than in control subjects and this difference rose to 32% for purely cancellous bone tissue. The whole bone cross-sectional area of ultradistal radius, as measured by pQCT, was superimposable to normal. At the proximal radius, both cross-sectional area and cortical area, together with Bending Breaking Resistance Index (BBRI), were significantly lower in OI (-23; -22; -32% respectively; p<0.001 for body weight and height adjusted values), but cortical volumetric density was even slightly higher in the OI group than in control subjects. In conclusion, it appears that the most obvious defect in adults with OI is the inability to acquire an adequate thickness of the cortices of long bone and to achieve or maintain normal trabecular density. 相似文献
15.
16.
17.
Georges Dellatolas Lucia Willadino Braga Ligia do Nascimento Souza Gilberto Nunes Filho Elizabeth Queiroz Gerard Deloche 《Journal of the International Neuropsychological Society》2003,9(5):771-782
The effect of the degree of illiteracy (complete or incomplete) on phonological skills, verbal and visual memory and visuospatial skills is examined in 97 normal Brazilian adults who considered themselves illiterate, and 41 Brazilian school children aged 7 to 8 years, either nonreaders or beginning readers. Similar literacy effects were observed in children and in adults. Tasks involving phonological awareness and visual recognition memory of nonsense figures distinguish the best nonreaders and beginning readers. Children performed better than adults at oral repetition of short items and figure recall, and adults better than children at semantic verbal fluency, digit span, and word list recall. A principal component analysis of the correlations between tasks showed that phonological awareness/reading, phonological memory/oral repetition, and semantic verbal memory/fluency tasks, generated different components. The respective role of culturally based preschool activities and literacy on the cognitive functions that are explored in this study is discussed. 相似文献
18.
Braga M Baccari P Radaelli G DiCarlo V Gianotti L Cristallo M 《Clinical nutrition (Edinburgh, Scotland)》1989,8(4):197-201
To identify patients at high-risk for post-operative infections, several methods have been proposed, including prognostic nutritional index (PNI), instant nutritional assessment (INA) and nutritional assessment (NA). Weight loss (WL) has also been related to post-operative morbidity. We have evaluated the prognostic ability of PNI, INA, NA and WL in a prospective study carried out in 94 patients affected by gastro-intestinal malignancy, who underwent major surgery. Post-operative infections occurred in 26 (27.7%) patients. PNI, INA and NA identified classes of patients with a progressive risk of septic complications. To determine the prognostic ability of PNI, INA, NA and WL, sensitivity, specificity, Youden index and predictive values were evaluated. All methods had a Youden index greater than one, with a positive predictive value ranging from 0.33 to 0.36. Since all the methods studied showed a similar predictive ability, it seems reasonable to identify the high-risk surgical patient by using weight loss in association with those nutritional parameters derived from routine hospital laboratory tests. 相似文献
19.
Edward?J?HolloxEmail author Jane?Davies Uta?Griesenbach Juliana?Burgess Eric?WFW?Alton John?AL?Armour 《Journal of negative results in biomedicine》2005,4(1):9
Human beta-defensin 2 (DEFB4, also known as DEFB2 or hBD-2) is a salt-sensitive antimicrobial protein that is expressed in
lung epithelia. Previous work has shown that it is encoded in a cluster of beta-defensin genes at 8p23.1, which varies in
copy number between 2 and 12 in different individuals. We determined the copy number of this locus in 355 patients with cystic
fibrosis (CF), and tested for correlation between beta-defensin cluster genomic copy number and lung disease associated with
CF. No significant association was found. 相似文献
20.
Missense FGFR3 mutations create cysteine residues in thanatophoric dwarfism type I (TD1) 总被引:10,自引:1,他引:10
Rousseau F; el Ghouzzi V; Delezoide AL; Legeai-Mallet L; Le Merrer M; Munnich A; Bonaventure J 《Human molecular genetics》1996,5(4):509-512
Thanatophoric dwarfism (TD) is a sporadic lethal skeletal dysplasia with
micromelic shortening of the limbs, macrocephaly, platyspondyly and reduced
thoracic cavity. In the most common subtype (TD1), femurs are curved, while
in TD2, straight femurs are associated with cloverleaf skull. Mutations in
the fibroblast growth factor receptor 3 (FGFR3) gene were identified in
both subtypes. While TD2 was accounted for by a single recurrent mutation
in the tyrosine kinase 2 domain, TD1 resulted from either stop codon
mutations or missense mutations in the extracellular domain of the gene.
Here, we report the identification of FGFR3 mutations in 25/26 TD cases.
Two novel missense mutations (Y373C and G370C) were detected in 8/26 and
1/26 TD1 cases respectively. Both mutations created cysteine residues in
the juxta extramembrane domain of the receptor. Sixteen cases carried the
previously reported R248C (9/26 cases), S249C (2/26 cases) or stop codon
FGFR3 mutations (5/26 cases). Our results suggest that TD1 is a genetically
homogeneous condition and give additional support to the view that newly
created cysteine residues in the extracellular domain of the protein play a
key role in the severity of the disease.
相似文献