全文获取类型
收费全文 | 1881篇 |
免费 | 118篇 |
国内免费 | 20篇 |
专业分类
儿科学 | 38篇 |
妇产科学 | 40篇 |
基础医学 | 267篇 |
口腔科学 | 16篇 |
临床医学 | 165篇 |
内科学 | 460篇 |
皮肤病学 | 55篇 |
神经病学 | 243篇 |
特种医学 | 52篇 |
外科学 | 227篇 |
综合类 | 2篇 |
一般理论 | 1篇 |
预防医学 | 74篇 |
眼科学 | 17篇 |
药学 | 157篇 |
中国医学 | 4篇 |
肿瘤学 | 201篇 |
出版年
2024年 | 3篇 |
2023年 | 18篇 |
2022年 | 34篇 |
2021年 | 55篇 |
2020年 | 36篇 |
2019年 | 41篇 |
2018年 | 55篇 |
2017年 | 45篇 |
2016年 | 51篇 |
2015年 | 66篇 |
2014年 | 71篇 |
2013年 | 105篇 |
2012年 | 164篇 |
2011年 | 149篇 |
2010年 | 78篇 |
2009年 | 78篇 |
2008年 | 102篇 |
2007年 | 114篇 |
2006年 | 138篇 |
2005年 | 122篇 |
2004年 | 99篇 |
2003年 | 101篇 |
2002年 | 81篇 |
2001年 | 16篇 |
2000年 | 20篇 |
1999年 | 18篇 |
1998年 | 17篇 |
1997年 | 15篇 |
1996年 | 13篇 |
1995年 | 10篇 |
1994年 | 8篇 |
1993年 | 10篇 |
1992年 | 10篇 |
1991年 | 8篇 |
1990年 | 10篇 |
1989年 | 9篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1986年 | 6篇 |
1985年 | 11篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1966年 | 2篇 |
1959年 | 1篇 |
排序方式: 共有2019条查询结果,搜索用时 9 毫秒
101.
Ziino O Russo D Orlando MA Benigno V Locatelli F Aricò M 《Medical and pediatric oncology》2002,39(1):32-34
BACKGROUND: Antimetabolite-based continuation therapy is commonly used for childhood acute lymphoblastic leukemia (ALL) and hypoglycemia after prolonged fasting has been recently reported. We have found that spontaneous, symptomatic hypoglycemia (SH) may also occur in such patients. PROCEDURE: Between 1995 and 1999, patients treated according to the AIEOP-ALL-95 study received BFM-type intensive chemotherapy; mercaptopurine (6-MP) was given (60 mg/m(2)/days, orally for 14 days) during the second part of induction and during consolidation therapy (25 mg/m(2)/day, orally for 8 weeks); thioguanine (6-TG) was given during reinduction therapy with protocol II (60 mg/m(2)/day, orally for 14 days); continuation therapy consisted of a combination of 6-MP (50 mg/m(2)/day orally) and methotrexate (MTX, 20 mg/m(2)/weekly, i.m.). We reviewed the charts of all patients treated for childhood ALL at our two centers. This was done to assess the incidence and the characteristics of all episodes of SH: sweating, pallor, nausea, abdominal pain with or without transient alterations of alertness, in the presence of blood glucose level of under 60 mg/dl. RESULTS: Six of 86 patients (6.9%) developed 18 episodes of SH. Five were male, none was older than 5 years, and four were only 3 years old. SH episodes occurred during consolidation (n = 2), reinduction (n = 7), and continuation (n = 9) phases. CONCLUSIONS: SH is a rare complication associated with administration of the purine analogues, mercaptopurine and thioguanine to children with reduced fat storage and young age. 相似文献
102.
Twenty-one day administration of dienogest reversibly suppresses gonadotropins and testosterone in normal men 总被引:4,自引:0,他引:4
Meriggiola MC Bremner WJ Costantino A Bertaccini A Morselli-Labate AM Huebler D Kaufmann G Oettel M Flamigni C 《The Journal of clinical endocrinology and metabolism》2002,87(5):2107-2113
Androgen-progestin combinations are promising male contraceptive regimens. Optimization of these regimens includes the development of new progestins with more favorable biological properties. In this context we tested the effects of the progestin dienogest (DNG) on reproductive hormones and metabolic parameters in men. After a 3-wk control period, 25 men were randomly assigned to receive daily doses of 2, 5, or 10 mg DNG or placebo and 10 mg cyproterone acetate for 21 d (n = 5 subjects/group). Subjects were followed for 2 wk after cessation of hormone administration. Weekly blood samples, physical examinations, hormone and chemistry measurements, semen analysis, and sexual/behavioral assessments were performed. These parameters were compared among study groups and within each group at different time points throughout the study periods. DNG and cyproterone acetate administration resulted in profound suppression of gonadotropins and T with no change in SHBG levels. No adverse effects were detected in any subject. Hormone levels returned to baseline after stopping hormone intake. DNG is a potent suppressor of gonadotropins and T in men and does not induce adverse effects over a 21-d administration. DNG is a promising progestin to be used in clinical trials for male contraception. 相似文献
103.
104.
Chiappe C De Rubertis A Piegari G Amato G Gervasi PG 《Chemical research in toxicology》2003,16(1):56-65
The stereochemical course of the biotransformation of 1,2-monoepoxides of 4-vinylcyclohexene (2 and 3) by liver microsomes from control and induced rats and by purified P4502B1 and P4502E1 has been determined. The epoxidation of monoexpodies cis-4-vinylcyclohexene 1,2-epoxide (2) and trans-4-vinylcyclohexene 1,2-epoxide (3) gives the corresponding eight isomeric diepoxides cis-4-vinylcyclohexene diepoxide (9) and trans-4-vinylcyclohexene diepoxide (10). The stereoselectivity of this process is affected by P450 induction. Phenobarbital is able to enhance the yield of epoxidation to give preferentially diepoxide (1R, 2S, 4R, 7R)-trans-10b. This enantiomer is also formed as nearly the sole product by P450-catalyzed epoxidation of (1R,2S,4R)-trans-3b, the monoepoxide that, as a consequence of the selective formation from 4-vinylcyclohexene and/or reduced elimination by epoxide hydrolase, tends to accumulate in rat. Also, the P4502B1 but not 2E1, in a reconstituted system, is able to perform the epoxidation of (1R,2S,4R)-trans-3b to produce selectively the same diepoxide. Diepoxides cis-9 and trans-10 are biotransformed by mEH catalyzed hydrolysis. Although the hydrolysis of diepoxides 9 is characterized by a lower substrate enantioselection, the reaction of diepoxides 10 occurs with a good substrate enantioselectivity favoring the hydrolysis of the epoxides (1R,2S,4R,7S)-trans-10b and (1S,2R,4S,7S)-trans-10a. Diepoxide (1R,2S,4R,7R)-trans-10b is therefore the isomer primarily formed by P450-catalyzed oxidation of monoepoxide trans-3, and it is also the compound showing the lower propensity to undergo mEH-catalyzed hydrolysis. On the basis of this result, the ovotoxicity of 4-vinylcyclohexene is expected to be due to the stereoisomer diepoxide (1R,2S,4R,7R)-trans-10b, whose biological reactivity, via cross-linking, may be strongly different to the other isomer diepoxides, being dependent by its specific conformation. 相似文献
105.
Hospital acquired blood stream infection by Ralstonia pickettii in 9 cancer patients related to the heparin solution contamination used to flush the central venous catheter. 相似文献
106.
Valentini V Piermattei A Morganti AG Gambacorta MA Azario L Macchia G Deodato F Cilla S Pepe D Grimaldi L Dinapoli N Cellini N 《Rays》2003,28(3):293-298
In the last two decades there was a radical change in radiotherapy setup. The growing availability of CT equipment and console for computer-aided treatment planning setup enabled the use of advanced technologies as conformal 3D radiation therapy in most centers. In particular in 1987 virtual simulation was proposed for setup. During its use a number of application modalities appeared. Virtual simulation in some centers is applied alone while in others it is associated with conventional simulation. However, from numerous reports published in last years it seems that virtual simulation significantly improves treatment quality independently of radical or palliative intent and of the size of treated volumes (high doses to small volumes or wide shaped fields). Some studies stressed that virtual simulation could significantly shorten treatment planning times with consequent cost reduction. The use of virtual simulation evidenced associated problems and in particular setup limitations due to the CT gantry size, the need to up-date the conventional modalities of setup verification according to the new technologies and more generally to up-date quality assurance procedures in an advanced technological setting. Finally there was the self-evident need of a better knowledge of the anatomy on axial sections, of tumor spread routes in particular. 相似文献
107.
Miracco C De Santi MM Luzi P Lalinga AV Laurini L De Nisi MC Angeloni G Brogi M Cardone C Carducci A Arcuri F Tosi P Rubino G Pirtoli L 《International journal of oncology》2003,23(6):1529-1535
Aberrations of genes/proteins regulating cell cycle and growth, increased proliferation and telomerase activity (TA) are documentable in glioblastoma multiforme. TA is more frequently detectable in secondary glioblastoma, which is also characterized by p53 mutation/overexpression. Discordant telomere (Te) length values have been reported in glioblastomas with and without TA. In 31 glioblastomas, in which pre-existing astrocytoma was not documented, we compared cases with and without TA for the expression of p53, EGFR, c-Myc, MIB-1 and Topoisomerase IIalpha; p53 mutations were also investigated by SSCP-PCR. Correlations were made with Te parameters [TePs: number (TeNo), length and area] as evaluated by image analysis in interphase nuclei of fluorescence in situ hybridization (FISH)-processed sections. We found no differences in the expression of the proteins evaluated and in TePs, except Te/nuclear area %, which was significantly lower in TA+ cases (p=0.02). TePs were, instead, inversely correlated with TA (p=0.0001). TA was positively correlated with MIB1 staining index in the TA+ cases (p=0.033), which also showed a positive correlation between TeNo and EGFR expression (p=0.042), and a trend towards a negative correlation between TeNo and p53 expression (p=0.05). Tumors overexpressing EGFR had a significantly shorter lifetime (p=0.0001). TeNo seems to be inversely correlated to tumor proliferation and lifetime in glioblastoma multiforme. 相似文献
108.
Conti P Roda G Stabile H Vanoni MA Curti B De Amici M 《Il Farmaco; edizione pratica》2003,58(9):683-690
A set of racemic conformationally constrained analogues of the antitumor antibiotic acivicin (+)-1 has been prepared through a strategy based on 1,3-dipolar cycloaddition of bromonitrile oxide to suitable dipolarophiles. The bromo analogue (2) of acivicin was also synthesized and tested as a reference compound, together with its stereoisomer 3. The antitumor properties of novel amino acids 4-7 were evaluated in vitro against human tumor cell lines. Their efficacy to inhibit glutamate synthase (GltS) from Azospirillum brasilense was also assayed. None of the studied compounds, but 2, showed significant activity. 相似文献
109.
Musto P Falcone A Sanpaolo G Bodenizza C Cascavilla N Melillo L Scalzulli PR Dell'Olio M La Sala A Mantuano S Nobile M Carella AM 《Leukemia & lymphoma》2003,44(9):1545-1548
Ninety patients with untreated, stage I-II A myeloma, were randomised to receive or not monthly infusions of pamidronate (PMD) for 1 year, without additional therapies. Follow-up ranged from 36 to 72 months (median 51 months). Three years after the start of the treatment, the disease had progressed in 25% of PMD treated patients and in 26.8% of controls (p n.s). Median time-to-progression was 16 and 17.4 months, respectively (p n.s). Among the 21 patients who required chemo-radiotherapy, skeletal events (osteolytic lesions, pathological fractures and/or hypercalcemia) developed in 9/11 (81.8%) controls and in 4/10 (40%) of treated patients (p < 0.01). "Prophylactic" administration of PMD may decrease the development of skeletal events, but does not reduce the rate and the time of disease progression in early-stage myeloma. 相似文献
110.
EEG power spectra changes and forebrain ischemia in rats 总被引:5,自引:0,他引:5
Mariucci G Stasi MA Taurelli R Nardò P Tantucci M Pacifici L Carminati P Ambrosini MV 《The Canadian journal of neurological sciences. Le journal canadien des sciences neurologiques》2003,30(1):54-60
BACKGROUND: Several animal models of cerebral ischemia have been developed to investigate both pathophysiology and pharmacological treatment. The aim of this study was to verify the prognostic value of EEG power spectra analysis in a two-vessel plus hypotension rat model of transient global ischemia. METHODS: Spontaneously hypertensive rats (SHRs) and Wistar Kyoto rats (WKYs) were subjected to 20 min bilateral common carotid artery occlusion plus hypotension by sodium nitroprusside followed by reperfusion for seven days. Sham-operated animals served as controls. The changes after ischemia in EEG power spectra, and their relations with neuronal damage and astrocytic response were investigated. RESULTS: The EEG analysis revealed that in SHRs and WKYs, ischemia produced a dramatic increase in delta activity and a decrease in theta, beta and alpha activities derived from both cortical and hippocampal areas. EEG activity reverted to normal values more quickly in WKYs than in SHRs which did not recover cortical and hippocampal alpha and beta activities even at six days of reperfusion. SHRs presented more severe damage and intense astrocytosis than WKYs in almost all the brain regions analyzed. In SHRs, hippocampal delta activity was positively correlated with the degree of neuronal necrosis and astrocytic activation, whereas theta, alpha and beta activities correlated negatively. No correlations were found in WKYs. CONCLUSIONS: These data indicate that the hippocampal bioelectrical activity recorded in SHRs from the beginning of reperfusion could be useful for predicting the ischemic outcome and evaluating the effects of pharmacological interventions. 相似文献