全文获取类型
收费全文 | 2947篇 |
免费 | 253篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 87篇 |
儿科学 | 159篇 |
妇产科学 | 72篇 |
基础医学 | 260篇 |
口腔科学 | 141篇 |
临床医学 | 239篇 |
内科学 | 594篇 |
皮肤病学 | 267篇 |
神经病学 | 153篇 |
特种医学 | 107篇 |
外科学 | 571篇 |
综合类 | 22篇 |
一般理论 | 1篇 |
预防医学 | 93篇 |
眼科学 | 81篇 |
药学 | 238篇 |
中国医学 | 10篇 |
肿瘤学 | 109篇 |
出版年
2023年 | 65篇 |
2022年 | 55篇 |
2021年 | 102篇 |
2020年 | 65篇 |
2019年 | 94篇 |
2018年 | 167篇 |
2017年 | 120篇 |
2016年 | 160篇 |
2015年 | 154篇 |
2014年 | 207篇 |
2013年 | 270篇 |
2012年 | 163篇 |
2011年 | 161篇 |
2010年 | 155篇 |
2009年 | 86篇 |
2008年 | 78篇 |
2007年 | 71篇 |
2006年 | 80篇 |
2005年 | 89篇 |
2004年 | 70篇 |
2003年 | 44篇 |
2002年 | 67篇 |
2001年 | 75篇 |
2000年 | 48篇 |
1999年 | 44篇 |
1998年 | 38篇 |
1997年 | 34篇 |
1996年 | 29篇 |
1995年 | 20篇 |
1994年 | 25篇 |
1993年 | 10篇 |
1992年 | 24篇 |
1991年 | 17篇 |
1990年 | 20篇 |
1989年 | 23篇 |
1988年 | 20篇 |
1987年 | 19篇 |
1986年 | 20篇 |
1985年 | 27篇 |
1984年 | 17篇 |
1983年 | 17篇 |
1982年 | 13篇 |
1979年 | 21篇 |
1978年 | 13篇 |
1977年 | 11篇 |
1975年 | 8篇 |
1974年 | 9篇 |
1973年 | 11篇 |
1972年 | 11篇 |
1967年 | 8篇 |
排序方式: 共有3204条查询结果,搜索用时 15 毫秒
1.
2.
The relaxant effects of electrical field stimulation (EFS) and exogenously applied acetylcholine (ACh) or acidified NaNO2 (a-NaNO2) were investigated in the isolated mouse corpus cavernosum precontracted with phenylephrine hydrochloride (PE). Tetrodotoxin (TTX) blocked the relaxant effects of EFS completely, whereas it had no effect on the responses to ACh or a-NaNO2. Guanethidine and indomethacin failed to affect the electrically or ACh-induced relaxations. Atropine completely blocked the effect of ACh; however, it caused a slight reduction in the relaxation evoked by EFS.N
G- Nitro-l-arginine (l-NOARG) reduced the effects of EFS and ACh significantly, but it was ineffective on the relaxations induced by a-NaNO2. The inhibitory action ofl-NOARG was partly restored byl-arginine, but not byd-arginine. Methylene blue (MB) and hydroxocobalamin (HC) exhibited significant inhibition on the relaxations evoked by EFS, ACh and a-NaNO2. Hydroquinone (HQ) reduced relaxation due to a-NaNO2, but did not affect that of EFS and ACh. Our findings suggest that EFS-induced relaxations of mouse cavernosal tissue are mediated by a transmitter which probably resembles an organic nitrate. 相似文献
3.
Z. Bircan M. Soran I. Yildirim M. Doĝan A. Şahin A. Bilici M. Danaci 《International urology and nephrology》1997,29(3):357-361
Radius, ulna, short bones (RUS), carpal (CARP) bone age (BA), tibial corticodiaphyseal (C/D) ratio and trabecular aspect were
assessed in 19 children with steroid dependent nephrotic syndrome and 15 age matched healthy children. Both RUS and CARP BA
were significantly lower than in the controls. Trabecular aspect and tibial C/D ratio did not show any statistical significance.
There was a positive correlation between HSDS and RUS BA delay (r=−0.476, p<0.05); CARP BA delay and RUS BA delay (r=0.563,
p<0.01) and RUS BA and CARP BA (r=0.891, p<0.001). In conclusion, RUS and CARP BA are both retarded and positively correlated
in steroid dependent nephrotic children. 相似文献
4.
Cemal Şenyuva Akın Yücel Yagmur Aydın Ihsan Okur Zeki Güzel 《Aesthetic plastic surgery》1997,21(4):233-239
Extracorporeal septoplasty is a radical solution for the severely deviated nose. The major problems associated with this
procedure are fixation of the septal cartilage graft and dorsal irregularities. Extracorporeal septoplasty was performed in
combination with open rhinoplasty in 17 patients with severe nasal deformities. In this technique septum was totally removed
through the columellar incision of open rhinoplasty, corrected outside, and replaced as a free ``L' shaped cartilage graft.
The cartilage graft was fixated to the upper lateral cartilages to restore the natural relations of the anatomical structures.
Additional rhinoplastic manipulations were also performed. The follow-up period was up to 18 months. The overall result was
successful in all patients. Nasal deviation did not recur and secondary revisions were not needed for any patient during follow-up. 相似文献
5.
Mamta Sharma Dorine Berriel-Cass Joseph Baran 《Infection control and hospital epidemiology》2004,25(6):468-471
OBJECTIVE: Surgical-site infection (SSI) is a serious and costly complication following coronary artery bypass graft (CABG). We analyzed surgical factors, microbiology, and complications at a 608-bed community teaching hospital to identify opportunities for prevention. METHODS: All patients undergoing CABG procedures from June 1997 through December 2000 were analyzed. Hospital records and postdischarge surveillance data were reviewed for demographics, surgical information, timing and classification of infection, microbiology, and bacteremic events. RESULTS: Of 3,443 patients undergoing CABG, sternal SSI developed in 122 (3.5%); 71 (58.2%) were classified as superficial SSI and 51 (41.8%) as deep SSI. Surgical antimicrobial prophylaxis was employed in all cases. On average, infection occurred 21.5 days (range, 4 to 315) after CABG. Most cases were diagnosed on readmission (59%); 20 cases (16%) were identified by postdischarge surveillance. Microbiological data were positive in 109 (89.3%), with a single pathogen implicated in most (86.2%). Gram-positive cocci were most frequently recovered (81%); gram-negative bacilli (17%), gram-positive bacilli (1%), and yeast (1%) were less common. Staphylococcus aureus was the most frequently isolated pathogen (49%). Bacteremia was noted in 22 instances (18%). It was significantly associated with deep SSI (P =. 002) and identified only in S. aureus cases. CONCLUSIONS: SSI complicated 3.5% of the procedures. S. aureus was implicated in most of the cases and was significantly associated with deep SSI. It was the only pathogen associated with secondary bacteremia. In addition to standard guidelines, targeted methods against S. aureus should help reduce the overall rate of SSI. 相似文献
6.
D T Baran A M Sorensen T W Honeyman R Ray M F Holick 《Journal of bone and mineral research》1990,5(5):517-524
1 alpha,25-Dihydroxyvitamin D3 rapidly increases cytosolic calcium and alters membrane phospholipid metabolism in hepatocytes. To define the causal relationship between these events, we examined the effects of 1 alpha,25-dihydroxyvitamin D3 on 32P-labeled lysophosphatidylinositol levels and cytosolic calcium as affected by pertussis toxin and 1 beta,25-dihydroxyvitamin D3, the biologically inactive analog. 32P-labeled lysophosphatidylinositol was determined by two-dimensional thin-layer chromatography. Cytosolic calcium was measured in cells loaded with quin-2AM. Within 5 min, 1 alpha,25-dihydroxyvitamin D3 increased hepatocyte cytosolic calcium by 31% (p less than 0.05) and 32P-labeled lysophosphatidylinositol by 38% (p less than 0.05). Pertussis toxin inhibited the hormone-induced rise in cytosolic calcium but not the increase in 32P-labeled lysophosphatidylinositol. Exposure to exogenous lysophosphatidylinositol for 5 min increased cytosolic calcium by 40% (p less than 0.05), an effect that was also inhibited by pertussis toxin. 1 beta,25-Dihydroxyvitamin D3 had no effect on either hepatocyte cytosolic calcium or 32P-labeled lysophosphatidylinositol but prevented the 1 alpha,25-dihydroxyvitamin D3-induced increments. The results suggest that a G protein sensitive to pertussis toxin is required for the transduction of the lysophosphatidylinositol signal but not the generation of the signal. The ability of 1 beta,25-dihydroxyvitamin D3 to inhibit the 1 alpha,25-dihydroxyvitamin D3-induced changes in phospholipids suggests that the epimer may compete with 1 alpha,25-dihydroxyvitamin D3 for an initiating receptor. 相似文献
7.
Vendeville B.; Baran D.; Gascon-Barre M.; Rubin E.; Luu T.; Vallieres S. 《Nephrology, dialysis, transplantation》1995,10(11):2020-2026
BACKGROUND.: Mercuric chloride (HgCl2 induces a lymphoproliferative disorderand autoimmune glomerulonephritis in Brown Norway (BN) rats.This syndrome is the consequence of T cell-dependent polyclonalB cell activation and autoantibody production. We have previouslyshown that HgCl2-induced autoimmune perturbations can be preventedin BN rats by the administration of cyclosporin A (CsA). Themost potent vitamin D3 metabolite 1,25(OH)2 D3 (Vit D3) sharescertain immunomodulatory properties with CsA. We therefore choseto compare the effects of Vit D3 to those of CsA in BN ratstreated with HgCl2 in order to establish whether Vit D3 eitheralone or in combination with CsA can attenuate an autoimmunesyndrome in vivo. METHODS.: BN rats were treated with HgCl2 according to a standard protocol.Subgroups of rats were also given CsA alone, Vit D3 or syntheticanalogues of Vit D3 alone, or combinations of both agents. Differentdoses and routes of administration were compared. The followingmarkers of disease activity were evaluated: mortality, peakproteinuria, serum IgE concentrations, and renal immunoglobulindeposition. RESULTS.: Disease activity was markedly attenuated in all rats treatedwith CsA alone. Vit D3 and certain of its synthetic analoguesadministered alone also tempered the autoimmune process, butto a lesser extent than did CsA. The effect of CsA alone wasso potent, that no additive or synergistic effects could bedemonstrated when CsA was administered in combination with VitD3. CONCLUSIONS.: Despite similar described immunomodulatory effects in vitro,CsA is clearly more effective than Vit D3 in preventing HgCl2autoimmune disease in BN rats. This suggests that there is adifference in the cellular targets of these two agents in vivo,and/or a difference in the potency with which HgCl2-triggeredimmune activation is suppressed. 相似文献
8.
9.
Teresa Baran Andrzej Duda Stanistaw Penczek 《Macromolecular chemistry and physics.》1984,185(11):2337-2346
The anionic polymerization of exo-3,4,5-trithiatetracyclo[5.5.1.O2,6.O8,12]tridec-10-ene ( 1 ) in bulk and/or in aromatic solvents (benzene, toluene) was studied. The polymerization was initiated with sodium benzenethiolate (sodium cation complexed with dibenzo-18-crown-6). Polymers with high-molecular weights were obtained (M n ≈ 105, osmometrically). The polymerization was found to be living and reversible; the equilibrium monomer concentration increases with the temperature. The ceilling temperature was estimated as 167°C. The thermodynamic data of the polymerization in toluene was determined and compared with those of the polymerization of exo-3,4,5-trithiatricyclo[5.2.O2,6]decane. The standard enthalpy ΔH = ?(6,6 ± 0,6)kJ · mol 1 and entropy ΔS = ?(29,3 ± 2,1)J · mol 1 · K 1 of the polymerization of 1 were evaluated from the temperature dependence of the equilibrium monomer concentration, determined dilatometrically. 相似文献
10.
Łuszczek W Kubicka W Cislo M Nockowski P Mańczak M Woszczek G Baran E Kuśnierczyk P 《Immunology letters》2003,85(1):59-64
Association of psoriasis vulgaris with HLA-C is not equally strong in different human populations. It has not yet been studied in Polish patients at DNA level, but only by serology that is inadequate for HLA-C. Therefore, we examined the distribution of HLA-C alleles by means of low resolution PCR-SSP in 102 Polish psoriatics and 123 healthy controls. We have found significantly higher representation of HLA-Cw*06 (odds ratio, 18.73; P(cor)<0.001) and significantly lower representation of HLA-Cw*07 (odds ratio, 0.41; P(cor)<0.038) in patients than in controls. Association of HLA-Cw*06 with psoriasis was even stronger in early age at onset (0-20 years) group: odds ratio, 77.71; P(cor)<0.001. Therefore, our population seems to belong to those with strong association of psoriasis with HLA-Cw*06. 相似文献