全文获取类型
收费全文 | 8366篇 |
免费 | 20篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 260篇 |
儿科学 | 32篇 |
妇产科学 | 139篇 |
基础医学 | 1008篇 |
口腔科学 | 260篇 |
临床医学 | 1577篇 |
内科学 | 842篇 |
皮肤病学 | 18篇 |
神经病学 | 105篇 |
特种医学 | 424篇 |
外科学 | 1954篇 |
综合类 | 35篇 |
预防医学 | 598篇 |
眼科学 | 155篇 |
药学 | 304篇 |
肿瘤学 | 690篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 4篇 |
2018年 | 4篇 |
2017年 | 7篇 |
2016年 | 6篇 |
2015年 | 8篇 |
2014年 | 10篇 |
2013年 | 13篇 |
2012年 | 320篇 |
2011年 | 670篇 |
2010年 | 324篇 |
2009年 | 22篇 |
2008年 | 478篇 |
2007年 | 682篇 |
2006年 | 696篇 |
2005年 | 686篇 |
2004年 | 800篇 |
2003年 | 801篇 |
2002年 | 866篇 |
2001年 | 543篇 |
2000年 | 737篇 |
1999年 | 385篇 |
1998年 | 141篇 |
1997年 | 28篇 |
1996年 | 14篇 |
1995年 | 14篇 |
1994年 | 15篇 |
1993年 | 36篇 |
1992年 | 5篇 |
1991年 | 9篇 |
1990年 | 3篇 |
1989年 | 7篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 13篇 |
1984年 | 3篇 |
1983年 | 7篇 |
1982年 | 4篇 |
1981年 | 5篇 |
1980年 | 5篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1972年 | 3篇 |
1955年 | 1篇 |
排序方式: 共有8401条查询结果,搜索用时 15 毫秒
11.
We studied follow-up iliac mucosa biopsies from 11 patients with juvenile polyposis and 4 patients with familial adenomatous polyposis who had undergone total colectomy with mucosal proctoectomy with creation of straight ileoanal anastomosis. The biopsies that have been taken from the posterior wall of the terminal ileum show incomplete and focal neocolonic transformation of iliac mucosa. Nevertheless, in most cases iliac mucosa preserved its architectural and histochemical characteristics. Chronic inflammation in iliac mucosa is not typical for patients with polyposis. 相似文献
12.
Pancreatic hormone amylin and integrity of the gastric mucosa 总被引:1,自引:0,他引:1
German SV Zhuĭkova SE Komarov FI Kopylova GN Kuper GJ Luk'iantseva GV Samonina GE Smirnova EA Umarova BA 《Vestnik Rossi?sko? akademii meditsinskikh nauk / Rossi?skaia akademiia meditsinskikh nauk》2001,(12):34-38
The paper presents experimental findings of some possible mechanisms of protective antiulcerous action of amyline. Amyline is the second beta-cell pancreatic hormone, which has been just recently discovered. The authors have studied the effects of amyline on gastric secretion, mast cell functions, mesenteric lymphatic microvascular contractility, i.e. on individual aggressive and protective factors of the gastric mucosa. Amyline has been found to inhibit basal acid gastric secretion and the secretion stimulated by vagal irritation. The peptide reduces the secretory activities of mast cells. Amyline given to animals increases the heparin saturation index of mast cells and decreases the degranulation index. Amyline-induced stabilization of mast cells appears to followed by the decreased release of histamine and other damaging substances. The stimulating effect of amyline on the contractile activity of mesenteric lymphatic vessels was recorded in rats. Amyline increases both the frequency and amplitude of their contractions. The increased lymph flow that is closely associated with microcirculation promotes the maintenance of tissue homeostasis. Therefore, the protective antiulcerous properties of amyline reduce the action of aggressive agents on the gastric mucosa and stimulate protective ones. 相似文献
13.
Korzhevskiĭ DE Gilerovich EG Zin'kova NN Grigor'ev IP Otellin VA 《Morfologii?a (Saint Petersburg, Russia)》2005,128(5):76-78
The aim of the present study was to find optimal protocol of immunocytochemical reaction to NeuN nuclear protein for light and laser confocal microscopy, which would exclude the antigen heat unmasking procedure that results in deteriorating the state of the tissue and requires expensive adhesive-coated slides. Best preservation of the antigen was found to be provided by fixation in zinc-formalin and Bouin's fixative (for a period of less than 24 hrs). Two protocols allowing to avoid antigen heat unmasking procedure during demonstration of the NeuN neuronal label in paraffin sections by the light and confocal microscopy are presented. 相似文献
14.
Khalturina EO Lebedinskaia OV Shubina IZh Donenko FV Raĭkhlin NT Kiselevskiĭ MV 《Morfologii?a (Saint Petersburg, Russia)》2004,125(3):89-92
Morphological features and immunophenotype of mature dendritic cells (DC) generated from the monocytes of healthy donor blood after culture with GM-CSF and IL-4 with the addition of TNF, were studied using light and electron microscopy, as well as flow-cytometry. It was shown that DC were characterized by a number of morphological features such as: large size, eccentrically located nucleus, highly developed system of extensions, large vacuolated cytoplasm, prominent and activated Golgi complex and ribosomal apparatus. Mature DC are characterized by active surface expression of MHC and co-stimulatory molecules (MHC I, MHC II, CD40, CD80, CD86). 相似文献
15.
Grigor'eva EP Desheva IuA Donina SA Naĭkhin AN Rekstin AR Barantseva IB Zavitkova EA Moskvicheva TM Zhavoronkov VG Rudenko LG 《Voprosy virusologii》2002,47(4):24-27
In Russia for prevention of influenza in children, aged from 3 to 14 years, the children's live influenza vaccine (LIV), based upon A/Leningrad/134/47/57(H2N2) master strain (LIVI) is used. The need for double immunization appears to be one out of the faulties of this preparation. The study was aimed to comparing the safety, immunogenic activity and prevention of influenza by LIV for adults (LIVII) (A/Leningrad/134/17/57(H2N2 master strain) and LIVI in children aged from 7 to 17 years under similar administration schedule. The safety, the preventive efficacy, humoral and secretory immunity were studied. In total 2486 persons, including 539 children, twice inoculated with LIVI, 971 persons once inoculated with LIVII, and 840 treated by placebo were obserbed. From the data of the clinical observations during 7 days after immunization both vaccines appeared to be low reactogenic. The LIVII advantages in induction of the humoral and secretory antibodies in comparison with children's vaccine had been revealed. Both vaccines were highly efficacious, the efficiency of both preparations was more pronounced after serologic correction of the diagnosis. The results obtained permit to recommend the single immunization by the variant of LIV at the base on A/Leningrad/134/17/57/(H2N2) master strain for prevention of influenza in school children. 相似文献
16.
Nozdrin VI Belousova TA Kinzirskiĭ AS Lavrik OI Zhuchkov SA Krutykh EG 《Morfologii?a (Saint Petersburg, Russia)》2004,126(5):56-60
Changes of the histological structure of rat's skin were studied two weeks following the daily applications of native birch tar and of purified birch tar, devoid of the components that could be potentially dangerous for humans. The morphometric investigations were performed with the use of computer technologies on the apparatus-programme complex (DiaMorph, Russia). It has been established that the main morphological manifestations of specific dermatotropic activity of birch tar in the present experiment included: epidermal hypertrophy, hyperkeratosis, stimulation of the activity of all dermal cellular elements, intensification of blood supply, reduction of sebaceous glands. Analysis of morphological findings indicates the bioequivalence of the native and purified birch tar in terms of its specific dermatotropic activity. 相似文献
17.
Babmindra VP Novozhilova AP Bragina TA Kreĭchman GS Miasnikova OE Zhilinskaia NT Kolla GV 《Morfologii?a (Saint Petersburg, Russia)》1998,114(6):22-27
Using light and electron microscopy structural bases for intracellular, extracellular and integrative regulation of synaptic efficiency and neuron sensitivity were established in rat sensomotor cortex. Intracellular regulation is realized basically through modulation of postsynaptic components of the synapse, while extracellular one is provided by synaptic endings of "recurrent" axons on GABA-ergic relay and interneurons. Integrative regulation is realized by means of concentration of similar axonal terminals in restricted cortical area and arrangement of "neuromediatory" pool. 相似文献
18.
The effects of co-culture with human fibroblasts on human embryo development in vitro and implantation 总被引:5,自引:0,他引:5
Wetzels AM; Bastiaans BA; Hendriks JC; Goverde HJ; Punt-van der Zalm AP; Verbeet JG; Braat DD 《Human reproduction (Oxford, England)》1998,13(5):1325-1330
In a human in-vitro fertilization (IVF) programme, the effect of co-
culture of embryos with human fibroblasts was evaluated with respect to
pregnancy rate and embryo development. Patients were included in the study
after giving informed written consent. The IVF treatments were randomly
assigned by stratification of both age (<36 versus > or =36 years)
and previous IVF attempts (yes versus no). After fertilization was
established, the zygotes were transferred to a 4-well dish with or without
fibroblasts and cultured for 2 days. On the third day after ovum pick-up
(OPU), cell number and quality [5 (good) to 1 (poor)] of the embryos were
scored and a maximum of three embryos was transferred. Supernumerary
embryos of good quality were cryopreserved. The design of this study was a
group sequential trial with the objective of detecting differences between
pregnancy rates following IVF with conventional incubation or incubation in
co-culture with fibroblasts. This design included one evaluation at
half-way data collection. In the study, 148 patients had an OPU, of whom 77
were allocated to the co-culture group. There was no statistically
significant difference in pregnancy rate, cell number and embryo quality
between the two groups. The ongoing pregnancy rate per embryo transfer was
27% in co-culture and 30% in the conventional culture group. The
implantation rates per transferred embryo were 17 and 18% respectively.
Using a multivariate logistic regression model for the probability of
ongoing pregnancies, the odds ratio of co-culture, adjusted for age and
previous IVF attempts, was not statistically significant. In conclusion,
co-culture with human fibroblasts does not contribute to an improvement of
embryo quality nor to a higher pregnancy rate after IVF in an unselected
group of patients.
相似文献
19.
Trekova NA Iavorovskiĭ AG Solovova LE Shabalkin BV Krapivkin IA Smirnova LA Charnaia MA Poplavskaia NS 《Vestnik Rossi?sko? akademii meditsinskikh nauk / Rossi?skaia akademiia meditsinskikh nauk》2002,(5):13-17
Different blood saving methods are analyzed in 2000 cardiac surgical patients undergoing coronary and vascular bypass surgery in 1993 to 2000. The basic blood saving methods are as follows: intraoperative autoreinfusion (normovolemic thermodilution), reinfusion of the patient's blood, preoperative autologous plasma donation in combination with aprotinine, aminocapronic acid, etc. An analysis revealed a decrease in homologous blood components intraoperatively. Red blood cell transfusion decreased from 100% in 1993 to 44% in 2000, fresh frozen plasma and platelet transfusions did from 98 to 39% and from 96 to 1%, respectively. Intraoperative homologous blood transfusion could be avoided in 70% of those undergone coronary bypass surgery. 相似文献
20.
Gurtsevich VE Galetskiĭ SA Nered SN Novikova EV Iakovleva LS Land ChE Davydov MI Klimenkov AA Petrovichev NN Tokunaga M 《Vestnik Rossi?sko? akademii meditsinskikh nauk / Rossi?skaia akademiia meditsinskikh nauk》1999,(3):56-59
The present investigation was carried out to estimate the incidence of Epstein-Barr virus (EBV)-associated cases among gastric carcinoma (GC) patients in Russia. Carcinoma specimens from 184 patients with GC treated at the Cancer Research Center were investigated by EBV encoded RNA-1 (EBER-1) in situ hybridization. Seventeen (9.24%) cases showed uniform EBER-1 expression restricted to the carcinoma cells. Hybridized signals were not detected in the non-neoplastic gastric epithelium. EBV involvement was significantly more frequent among males, especially in the tumors belonging to less differentiated types (moderately differentiated tubular adenocarcinomas and poorly differentiated solid adenocarcinomas) and located in the upper stomach (cardia and middle part). Most EBV-positive GCs were characterized by great lymphoid compartment involvement. The findings of the distribution of EBV-positive. GCs by sex, site, and histology are similar to those in Japan; however, the detection rate of EBV-positive cases in Russia is higher than that in Japan (6.7%) and lower than that in the USA (16%). 相似文献