全文获取类型
收费全文 | 3317篇 |
免费 | 283篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 115篇 |
妇产科学 | 200篇 |
基础医学 | 259篇 |
口腔科学 | 47篇 |
临床医学 | 384篇 |
内科学 | 660篇 |
皮肤病学 | 112篇 |
神经病学 | 281篇 |
特种医学 | 189篇 |
外科学 | 528篇 |
综合类 | 105篇 |
现状与发展 | 30篇 |
一般理论 | 1篇 |
预防医学 | 127篇 |
眼科学 | 35篇 |
药学 | 240篇 |
中国医学 | 5篇 |
肿瘤学 | 281篇 |
出版年
2024年 | 20篇 |
2023年 | 194篇 |
2022年 | 32篇 |
2021年 | 51篇 |
2020年 | 72篇 |
2019年 | 52篇 |
2018年 | 88篇 |
2017年 | 75篇 |
2016年 | 66篇 |
2015年 | 87篇 |
2014年 | 126篇 |
2013年 | 130篇 |
2012年 | 125篇 |
2011年 | 125篇 |
2010年 | 128篇 |
2009年 | 152篇 |
2008年 | 114篇 |
2007年 | 147篇 |
2006年 | 117篇 |
2005年 | 149篇 |
2004年 | 110篇 |
2003年 | 93篇 |
2002年 | 91篇 |
2001年 | 80篇 |
2000年 | 65篇 |
1999年 | 105篇 |
1998年 | 62篇 |
1997年 | 73篇 |
1996年 | 58篇 |
1995年 | 57篇 |
1994年 | 51篇 |
1993年 | 52篇 |
1992年 | 49篇 |
1991年 | 61篇 |
1990年 | 58篇 |
1989年 | 64篇 |
1988年 | 60篇 |
1987年 | 46篇 |
1986年 | 25篇 |
1985年 | 43篇 |
1984年 | 27篇 |
1983年 | 23篇 |
1982年 | 22篇 |
1981年 | 21篇 |
1980年 | 20篇 |
1979年 | 20篇 |
1978年 | 17篇 |
1976年 | 18篇 |
1975年 | 16篇 |
1974年 | 16篇 |
排序方式: 共有3622条查询结果,搜索用时 15 毫秒
1.
A mixed‐method study of effects of a therapeutic play intervention for children on parental anxiety and parents' perceptions of the intervention 下载免费PDF全文
2.
Sarah A. Taylor Jacqueline Benedetti David Schuller Stephen P. Richman Goronwy O. Broun Alexander Hantel 《Investigational new drugs》1993,11(2-3):227-229
Summary Twenty-two patients with recurrent or metastatic squamous cell carcinoma of the head and neck were treated with piroxantrone 150 mg/m2 intravenously every 21 days. There were no objective responses. The 95% upper confidence bound for response is 15%. Primary toxicity was hematologic. 相似文献
3.
Synergistic antiproliferative activity of quercetin and cisplatin on ovarian cancer cell growth 总被引:1,自引:0,他引:1
G Scambia F O Ranelletti P Benedetti Panici G Bonanno R De Vincenzo M Piantelli S Mancuso 《Anti-cancer drugs》1990,1(1):45-48
It has been demonstrated that the flavonoid quercetin (3,3',4',5-7-pentahydroxyflavone) (Q) inhibits the growth of several cancer cell lines and that the antiproliferative activity of this substance is mediated by a so-called type II estrogen binding site (type II EBS). We investigated the effects of quercetin and cisplatin (CDDP) alone and in combination on the proliferation of the ovarian cancer cell line OVCA 433. Both drugs exhibited a dose-related growth inhibition in a range of concentrations between 0.01 and 2.5 microM and 0.01 and 2.5 micrograms/ml for Q and CDDP respectively. The combination of the two drugs resulted in a synergistic antiproliferative activity. Two other flavonoids tested, i.e., rutin (3-rhamnosylglucoside of quercetin) and hesperidin [7-b rutinoside of hesperetin (3'-5-3-hydroxy-4-methoxyflavone)] were ineffective both alone and in combination with CDDP. Since both rutin and hesperidin do not bind to type II EBS it can be hypothesized that Q synergizes with CDDP by acting through an interaction with these binding sites. 相似文献
4.
5.
D. M. F. Edwards C. Pellizzoni H. P. Breuel A. Berardi M. G. Castelli E. Frigerio I. Poggesi M. Rocchetti A. Dubini M. Strolin Benedetti 《Biopharmaceutics & drug disposition》1995,16(6):443-460
The pharmacokinetics of reboxetine, a new antidepressant agent, were found to be close to linear in a crossover study comparing administration of single 2, 3, 4 and 5 mg capsule doses in 15 healthy male volunteers, and in the same study the capsules were bioequivalent to the proposed therapeutic tablet formulation (4mg). Kinetic analysis was based on HPLC assay of reboxetine in plasma and urine collected up to 72 h after each administration. Plasma levels indicated a rapid absorption (tmax?2h) and an elimination half-life of about 13 h. Clearance and volume of distribution were modest (ratios to bioavailability: CL/F?29 mL min?1; Vz/F?32L); urinary excretion was ~9% of dose, corresponding to a renal clearance of only 3 mL min?1 (a value consistent with the rate of glomerular filtration of unbound drug). In vitro, binding to plasma proteins, estimated from radioactivity levels following dialysis of 14C-labelled reboxetine, appeared to be dominated by α1-acid glycoprotein without marked saturation up to plasma concentrations of over 500 ng mL?1 (2.8–3.1% unbound with human plasma from three additional volunteers; 1.8–2.0% for 2gL?1 orosomucoid α1-acid glycoprotein, and 46.4–47.4% for 40 gL?1 albumin), whilst the mean Cmax in the current study was much lower (164 ng mL?1 after a 5 mg dose). 相似文献
6.
We performed a prospective clinical evaluation of our newly developed fluorescence polarization procedure to predict fetal lung maturity (Clin Chem 1986;32:248-54). Net fluorescence polarization was measured at 34 degrees C after a 6.5-min incubation of amniotic fluid with fluorophore. For the 26 cases of neonatal respiratory distress syndrome encountered in 196 deliveries, the net polarization exceeded 0.287 for 22 (85%) of these, and exceeded 0.260 for all 26. The specificity of the polarization assay equaled or exceeded the specificity of the lecithin/sphingomyelin ratio for all sensitivities greater than 70%. Neither assay was a good predictor of the clinical severity of respiratory distress. For a separate group of 21 amniotic fluid specimens clinically contaminated with blood or meconium, the discriminatory power of the polarization assay was decreased, but six of seven respiratory-distress cases still had polarization values greater than 0.260. We conclude that this fluorescence polarization assay is a better overall predictor of fetal lung maturity than is the lecithin/sphingomyelin ratio, and that polarization values less than 0.260 are associated with little risk of respiratory distress. 相似文献
7.
Renal transplantation for patients 60 years of older. A single-institution experience. 总被引:1,自引:0,他引:1 下载免费PDF全文
E Benedetti A J Matas N Hakim C Fasola K Gillingham L McHugh J S Najarian 《Annals of surgery》1994,220(4):445-460
OBJECTIVE: The authors reviewed renal transplant outcomes in recipients 60 years of age or older. BACKGROUND: Before cyclosporine, patients older than 45 years of age were considered to be at high risk for transplantation. With cyclosporine, the age limits for transplantation have expanded. METHODS: The authors compared patient and graft survival, hospital stay, the incidence of rejection and rehospitalization, and the cause of graft loss for primary kidney recipients 60 years of age or older versus those 18 to 59 years of age. For those patients > or = 60 years transplanted since 1985, the authors analyzed pretransplant extrarenal disease and its impact on post-transplant outcome. In addition, all surviving recipients > or = 60 years completed a medical outcome survey (SF-36). RESULTS: Patient and graft survival for those > or = 60 years of age versus those 18 to 59 years of age were similar 3 years after transplant. Subsequently, mortality increased for the older recipients. Death-censored graft survival was identical in the two groups. There were no differences in the cause of graft loss. Those 60 years of age or older had a longer initial hospitalization, but had fewer rejection episodes and fewer rehospitalizations. Quality of life for recipients 60 years of age or older was similar to the age-matched U.S. population. CONCLUSION: Renal transplantation is successful for recipients 60 years of age or older. Most of them had extrarenal disease at the time of transplantation; however, extrarenal disease was not an important predictor of outcome and should not be used as an exclusion criterion. Post-transplant quality of life is excellent. 相似文献
8.
G Ferrandina G Scambia P Benedetti Panici G Almadori G Paludetti G Cadoni M Distefano M Maurizi S Mancuso 《Cancer letters》1992,67(2-3):133-138
Using an immunoradiometric assay, Cathepsin D (Cath D) levels were measured in the cytosol of 23 normal and 39 neoplastic human laryngeal tissues. Scattered Cath D levels (from 2.2 to 17.8 pM/mg protein; median = 7.6) were found in normal mucosa specimens. Cath D concentrations range from 2.0 to 29.3 pM/mg protein (median = 8.5) in laryngeal tumors. When a comparison between Cath D levels in normal and neoplastic tissue specimens from the same patient was done, Cath D levels were significantly higher in laryngeal cancers than in their normal counterparts (P = 0.03). No correlation with clinico-pathological parameters and steroid hormone and epidermal growth factor receptor status was found. Further studies should investigate whether the production of Cath D by laryngeal tumors could have a clinical relevance for this neoplasia. 相似文献
9.
Maternal counting of fetal movement (FM) to assess fetal well-being was studied in 394 pregnancies followed by family physicians. Counting was well accepted, with 85% of women finding it reassuring and 91% wanting to include it in subsequent pregnancies. Eighty-eight percent of women reported counting five or more days per week. Thirteen women reported decreased activity a total of 20 times. A nonstress test (NST) was performed 20 times and an oxytocin challenge test (OCT) was performed four times as a result of these reports. One of the 20 reports of decreased activity was followed by a nonreactive NST and suspicious OCT, and led to the induction of a viable 38-week fetus. There were no stillbirths in the group and only one neonatal death of an anencephalic infant. 相似文献
10.
The aim of the present study was to determine if data on the number and acinar distribution of apoptotic bodies (AB) in normal liver could help in the understanding of cell kinetics in the liver, and the mechanism of early ethanol-induced liver damage. Normal male Sprague-Dawley rats were studied. They had free access to Purina chow and drinking water. Ethanol-treated rats received the drug at increasing concentration in drinking water for 5 weeks. The following parameters were measured: number of AB in the lobule, topographical localization, distance from terminal hepatic veins (THV), i.e. row of hepatocytes concerned, H1 being the closest to the THV. The results show that AB are rare in the normal liver and are always observed in zone 3, next to the THV. Of 149 THV examined, 56 showed one associated AB, exceptionally two. 74% of the AB were confined to the first row of hepatocytes (H1), 21% to H2, 4% to H3, and 1% to H4. In ethanol-treated rats the mean number of AB was 2 or 3 for each THV. 42% were found in H1, 32% in H2, 15% in H3, 7% in H4, and 4% in H5. The data show that AB are not randomly dispersed in normal liver but show a preferential acinar distribution. In addition, most AB are located in the row of liver cells immediately adjacent to the THV. If apoptosis is indeed an expression of physiological cell renewal, these findings support the concept that zone 3 contains older hepatocytes.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献