全文获取类型
收费全文 | 1214篇 |
免费 | 55篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 39篇 |
妇产科学 | 18篇 |
基础医学 | 200篇 |
口腔科学 | 31篇 |
临床医学 | 123篇 |
内科学 | 264篇 |
皮肤病学 | 51篇 |
神经病学 | 97篇 |
特种医学 | 43篇 |
外科学 | 145篇 |
综合类 | 11篇 |
预防医学 | 62篇 |
眼科学 | 2篇 |
药学 | 89篇 |
中国医学 | 5篇 |
肿瘤学 | 88篇 |
出版年
2023年 | 6篇 |
2022年 | 17篇 |
2021年 | 41篇 |
2020年 | 16篇 |
2019年 | 23篇 |
2018年 | 34篇 |
2017年 | 18篇 |
2016年 | 18篇 |
2015年 | 26篇 |
2014年 | 27篇 |
2013年 | 39篇 |
2012年 | 94篇 |
2011年 | 76篇 |
2010年 | 33篇 |
2009年 | 35篇 |
2008年 | 59篇 |
2007年 | 51篇 |
2006年 | 49篇 |
2005年 | 38篇 |
2004年 | 50篇 |
2003年 | 38篇 |
2002年 | 41篇 |
2001年 | 21篇 |
2000年 | 18篇 |
1999年 | 22篇 |
1998年 | 8篇 |
1997年 | 7篇 |
1996年 | 10篇 |
1995年 | 11篇 |
1994年 | 15篇 |
1993年 | 16篇 |
1992年 | 42篇 |
1991年 | 24篇 |
1990年 | 25篇 |
1989年 | 42篇 |
1988年 | 20篇 |
1987年 | 27篇 |
1986年 | 25篇 |
1985年 | 24篇 |
1984年 | 13篇 |
1983年 | 10篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1980年 | 5篇 |
1979年 | 8篇 |
1978年 | 7篇 |
1977年 | 7篇 |
1974年 | 8篇 |
1973年 | 4篇 |
1972年 | 4篇 |
排序方式: 共有1278条查询结果,搜索用时 15 毫秒
81.
This work is concerned with a morphometric analysis of 23 breast fibroadenomas subdivided into four histological subgroups from purely pericanalicular to purely endocanalicular forms. The volume fractions (Vv) of the lumina and the total volume: epithelial surface ratios (Sv) showed a significant (P less than 0.001) correlation (r = + 0.64). In addition, the Vv and Sv series did not correlate with any of the histological subgroups. The data reported in this work suggest that the ductal epithelium proliferates in fibroadenomas, and that the subtypes are not related to the epithelial growth. 相似文献
82.
Leandro Provinciali Mario Signorino Bruno Censori Gabriella Ceravolo Maria Del Pesce 《Epilepsia》1991,32(5):684-689
The occurrence of transitory cognitive impairment during diffuse subclinical electroencephalographic (EEG) discharges has been widely documented but the role of the parameters influencing the cognitive performance and the involvement of motor or verbal response in the tasks used is still under debate. Fifteen patients suffering from primary generalized epilepsy with frequent bisynchronous EEG epileptic bursts underwent a shape recognition task during EEG monitoring. The test sequence was as follows: memorandum, pause, and multiple choice set. After pressing the response button, the patient was asked to confirm the choice verbally. The following parameters were considered: geometrical complexity of the shape, chronological position of the burst occurring during the single test, and the duration of discharge ranging from 1 to 3 s. Results showed a significant increase in incorrect responses during the test when discharges occurred, with more errors occurring for difficult than for easy shapes. Neither the discharge position nor the duration of the epileptic burst influenced the performance. Diffuse epileptic activity of short duration produced selective effects on the cognitive process regardless of the motor component of the response. 相似文献
83.
84.
Yuan Wei; Kiselyov Alexander S.; Harvey Ronald G.; Carothers Adelaide M. 《Carcinogenesis》1995,16(11):2869-2873
Polycyclic aromatic hydrocarbons (PAHs) with sterically hinderedfjord region diol epoxides are interesting with respect to theirpotency as carcinogens, interactions with DNA and mutagenicspecificities. Unlike the bay region PAH derivative, trans-7,8-dihydroxy-anti-9,10-epoxy-7,8,9,10-tetrahydroxybenzo[a]pyrene(BPDE), reactive metabolites of two fjord region PAH, trans-3,4-dihydroxy-anti-1,2-epoxy-1,2,3,4-tetrahydrobenzo[c]-Phenanthrene[(±)-anti-BcPHDE] and trans-11,12-dihydroxy-syn-13,14-epoxy-11,12,13,14-tetrabenzo[g]chrysene[(±)-syn-BgCDE], react with DNA to yield high levelsof adenine adducts. We previously found that forward mutationsinduced by (±)-anti-BcPHDE in the dihydrofolate reductase(dhfr) gene of Chinese hamster ovary (CHO) cells preferentiallytargeted mRNA splice acceptor sites. (±)-anti-BcPHDEand (±)-syn-BgCDE are structurally similar; they differonly by the presence of an additional benzene ring. Thus weused (±)-syn-BgCDE to learn if the mutational targetbias reflects aspects of the mutagen structure or its capacityto efficiently modify deoxyadenosine (dA) in vivo. dhfrmutants were induced after treatment of hemizygous UA21 cellswith a 0.75 µM dose of (±)-syn-BgCDE. Cell survivalafter carcinogen exposure was 40%. The induced mutation frequencywas 9x106, nearly 10-fold higher than the spontaneousone, but 相似文献
85.
Roger PM Perbost I Ticchioni M Fuzibet JG Breittmayer JP Durant J Pesce A Bernard A Dellamonica P;Groupe d'Etudes Niçois Polyvalent en Infectiologie 《The Journal of infection》2004,49(3):216-221
OBJECTIVE: Because the absence of immune restoration in HIV-infected patients efficiently treated by highly active antiretroviral therapy (HAART) may be due to excessive immune activation, we prospectively studied the effect of hydrocortisone on T-cell apoptosis in a cohort of patients with satisfactory virologic response. METHODS: Apoptosis of T-cell subsets including na?ve CD45RA(+)CD4+ T-cells was determined at baseline and at months 1 and 3 after initiation of HAART. A satisfactory immune response was defined as an increase >100/microL CD4+ T-cells at month 3 compared to baseline. RESULTS: Twenty out of 63 patients showed undetectable viral load at month 3, among whom eight exhibited a satisfactory immune response. Down-regulation spontaneous CD4+T-cell apoptosis was significant in the group of patients with a satisfactory immune response compared to the other patients. However, hydrocortisone up-regulated apoptosis of na?ve CD4+ CD45RA+ T-cells, specifically in group of patients with poor immune response, whatever the time point considered: percentage of apoptotic CD4 T-cells was 16+/-16% without hydrocortisone and 22+/-22% with hydrocortisone at month 1, and respectively, 10+/-9 and 17+/-15% at month 3 (P < 0.05) Hydrocortisone had no impact on CD8+ T-cell apoptosis, whatever the considered group. CONCLUSION: Our results suggest to not use steroid therapy as adjuvant immunotherapy in patients with less than optimal immunologic response to HAART. 相似文献
86.
T J Schroeder A J Pesce L L Hindenlang P A Mauser D L Ruckrigl M L Weibel G Wadih M R First 《Therapeutic drug monitoring》1989,11(4):480-482
The new Abbott TDx cyclosporine and metabolites fluorescent polarization immunoassay procedure provides a 20-min sample turn-around time, using 50 microliters of sample for the analysis of cyclosporine in whole blood. A precipitation agent and a lysing agent are utilized as a pretreatment step. The range of the whole blood assay is from 0 to 2,000 ng/ml, with a sensitivity of 50 ng/ml. Precision studies at 3 control levels provided coefficients of variation of 2.1-4.8% for both assays. In order to compare this assay with the currently used Sandoz polyclonal radioimmunoassay (RIA) method. 200 whole blood samples were obtained from 20 renal, cardiac, and hepatic transplant recipients. The mean whole blood cyclosporine concentrations for samples above the sensitivity level were as follows: TDx 754 ng/ml (+/- 31) and RIA 619 ng/ml (+/- 22). Blood TDx levels correlated strongly with RIA levels, with a regression coefficient of r = 0.915. This new assay provides reliable blood cyclosporine concentrations that correlate well with RIA measurements. This assay offers rapid sample turn-around times, making same-day results for outpatient drug monitoring possible. 相似文献
87.
88.
B T Walsh L M Wong M A Pesce C M Hadigan S H Bodourian 《The Journal of clinical psychiatry》1990,51(9):373-377
To determine the value of total serum amylase levels and salivary and pancreatic isoenzyme levels as biologic indices of behavioral disturbance in bulimia nervosa, the authors monitored these levels in 40 bulimic patients participating in a placebo-controlled trial of desipramine and in 25 controls. In the patients, the total and salivary amylase levels were significantly elevated and a significant correlation existed between the frequencies of binge eating and vomiting and the level of salivary amylase. However, the ability to discriminate patients from controls on the basis of serum amylase levels was limited. In addition, a significant positive relationship between binge frequency and level of serum amylase was observed in less than one quarter of 22 patients with five or more amylase determinations. Therefore, although hyperamylasemia is associated with bulimia nervosa, we believe that serum amylase determinations have limited utility in the assessment of patients with this syndrome. 相似文献
89.
C Pesce F Grillo-Ruggieri A L Maura 《Journal of environmental pathology, toxicology and oncology》1986,7(1-2):9-15
The ultrastructural appearances of preneoplastic liver nodules induced in male Wistar rats through sequential treatment with diethylnitrosamine (DENA) and 2-acetylaminofluorene (2-AAF) followed by partial hepatectomy were investigated. Although separately non-specific, the lesions reported represented altogether a fairly characteristic pattern consistent with previous observations in tumors and in preneoplastic nodules induced by long-term treatment with single carcinogens. Such data support the view that sequential treatment followed by partial hepatectomy is a reliable method to study early phenotypic changes in hepatocarcinogenesis. Such treatment is also advisable because it requires only a short period of latency in comparison to other in vivo screening tests of potential carcinogens. 相似文献
90.
Sharon S. Raimer M.D. Eliose L. Beightler M.D. Adelaide A. Hebert M.D. Elizabeth S. Head M. T. Edgar B. Smith M.D. 《Pediatric dermatology》1986,3(6):452-454
Tinea faciei has been observed periodically in children, however, it is a relatively rare occurrence in infancy. We examined three infants with tinea faciei caused by Trichophyton tonsurans. Two of the patients were potassium hydroxide (KOH) negative for fungal hyphae but culture positive, while the third was both KOH and culture positive. Trichophyton tonsurans was isolated from the scalp of family members in two of the three infants. 相似文献