全文获取类型
收费全文 | 6898篇 |
免费 | 351篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 210篇 |
儿科学 | 165篇 |
妇产科学 | 221篇 |
基础医学 | 944篇 |
口腔科学 | 381篇 |
临床医学 | 522篇 |
内科学 | 1573篇 |
皮肤病学 | 124篇 |
神经病学 | 516篇 |
特种医学 | 176篇 |
外科学 | 1059篇 |
综合类 | 36篇 |
预防医学 | 529篇 |
眼科学 | 155篇 |
药学 | 347篇 |
中国医学 | 35篇 |
肿瘤学 | 296篇 |
出版年
2023年 | 52篇 |
2022年 | 112篇 |
2021年 | 207篇 |
2020年 | 121篇 |
2019年 | 201篇 |
2018年 | 209篇 |
2017年 | 126篇 |
2016年 | 177篇 |
2015年 | 241篇 |
2014年 | 320篇 |
2013年 | 357篇 |
2012年 | 536篇 |
2011年 | 600篇 |
2010年 | 359篇 |
2009年 | 289篇 |
2008年 | 461篇 |
2007年 | 481篇 |
2006年 | 453篇 |
2005年 | 388篇 |
2004年 | 350篇 |
2003年 | 290篇 |
2002年 | 266篇 |
2001年 | 83篇 |
2000年 | 73篇 |
1999年 | 65篇 |
1998年 | 56篇 |
1997年 | 42篇 |
1996年 | 33篇 |
1995年 | 26篇 |
1994年 | 23篇 |
1993年 | 20篇 |
1992年 | 23篇 |
1991年 | 29篇 |
1990年 | 22篇 |
1989年 | 20篇 |
1988年 | 19篇 |
1987年 | 18篇 |
1986年 | 18篇 |
1985年 | 11篇 |
1984年 | 13篇 |
1983年 | 9篇 |
1982年 | 10篇 |
1981年 | 11篇 |
1980年 | 16篇 |
1979年 | 10篇 |
1978年 | 8篇 |
1976年 | 6篇 |
1974年 | 4篇 |
1973年 | 6篇 |
1970年 | 4篇 |
排序方式: 共有7289条查询结果,搜索用时 0 毫秒
21.
22.
23.
E L Khoury P M Cossio A Szarfman J C Marcos O García Morteo R M Arana 《American journal of clinical pathology》1978,69(1):62-65
One hundred fifty-six of 1,250 sera from patients with presumed connective tissue and related diseases showed vascular staining on mouse liver cryostat sections when they were routinely checked for antinuclear factor by the indirect immunofluorescence test. In a third of the cases, the vascular immunofluorescent pattern was given by the EVI antibody reacting with the plasma membrane of striated muscle fibers and endothelial cells, as has been recently described to occur in Chagas' disease. This led to the detection of previously unsuspected Trypanosoma cruzi infection in 67.8% of the serum samples in which the EVI antibody was detected after observation of a positive vascular pattern with mouse liver cryostat sections. On the other hand, no significant relationship between Chagas infection and sera with other anti-striated-muscle immunofluorescent patterns that also showed a vascular staining on mouse liver cryostat sections was established. Consideration of the vascular pattern observed with the EVI antibody on mouse liver cryostat sections can be helpful in detection of previously ignored T. cruzi infection in patients who have connective-tissue diseases and related conditions. This is of interest in view of the fact that anergic immunodepressive therapy, often used in these patients, significantly alters the host-parasite relationship and may lead to severe dissemination of the parasite. 相似文献
24.
Amadio Eliane Martins Marcos Rodrigo Labat Serra Andrey Jorge dos Santos Solange Almeida Caires Jheniphe Rocha Fernandes Guilherme Henrique Cardosos Leal-Junior Ernesto Cesar Ferrari João Carlos Correa de Tarso Camillo de Carvalho Paulo 《Lasers in medical science》2021,36(7):1427-1435
Lasers in Medical Science - Photobiomodulation therapy (PBMT) has been indicated for enforcement on healing skin wounds. This study evaluated the effects of PBMT on the healing of skin wounds... 相似文献
25.
A new approach to the study of ocular chromatic aberrations 总被引:2,自引:0,他引:2
We measured the ocular wavefront aberration at six different visible wavelengths (between 450 and 650 nm) in three subjects, using a spatially resolved refractometer. In this technique, the angular deviation of light rays entering the pupil at different locations is measured with respect to a target viewed through a centered pupil. Fits of the data at each wavelength to Zernike polynomials were used to estimate the change of defocus with wavelength (longitudinal chromatic aberration, LCA) and the wavelength-dependence of the ocular aberrations. Measured LCA was in good agreement with the literature. In most cases the wavefront aberration increased slightly with wavelength. The angular deviations from the reference stimulus measured using a magenta filter allowed us to estimate the achromatic axis and both optical and perceived transverse chromatic aberration (TCA), (including the effect of aberrations and Stiles-Crawford effect). The amount of TCA varied markedly across subjects, and between eyes of the same subject. Finally, we used the results from these experiments to compute the image quality of the eye in polychromatic light. 相似文献
26.
L Ramos J Marcos M Illanas M Hernández-Mora F Pérez-Payá J L Picouto P Santana C Chantar 《Radiology》1978,126(2):379-385
Radiological findings in 12 cases of "Mediterranean" lymphoma are analyzed, 4 of which are associated with gammapathy. These findings have not permitted differentiation of this type of lymphoma from those classically described, although there are two signs that strongly suggest this diagnosis: extension of the lesions along wide areas of the small intestine, almost always including the duodenum, and spiculation of the mucosal fold edges, representing massive plasmocyte infiltration of the lamina propria. The principal clinical, immunological, and pathological aspects are described, as well as the radiological differential diagnosis. 相似文献
27.
Marcos H Toyama Sérgio Marangoni José C Novello Gildo B Leite Julia Prado-Franceschi Maria Alice da Cruz-H?fling Léa Rodrigues-Simioni 《Toxicon》2003,41(4):493-500
Two major crotamine isoforms (F22 and F32) were obtained after three chromatographic steps and were assayed in mouse phrenic nerve-diaphragm preparations. F32 and F22 (0.5 microg/ml, n=4) produced a facilitatory effect, which increased isometric twitch-tension by 300 and 230%, respectively, after a 120 min incubation. At a concentration of 0.1 microg/ml, both isoforms increased the twitch-tension by about 160%. However, when the isoforms were co-incubated (final concentration, 0.5 microg/ml) for 30 min prior to testing, they did not cause the facilitation seen with > or =0.1 microg/ml of each isoform alone. Histologically, F32 and F22 at 0.5 and 1 microg/ml were quantitatively alike in inducing tissue myonecrosis. However, a mixture of the two isoforms (final concentration, 0.5 microg/ml) significantly attenuated the damage seen with either toxin alone. Mass spectrometry analysis showed that the isoforms had the same molecular mass (4.8 kDa) and that they existed as monomers with a highly stable structure. These results indicate that F22 and F32 acted on muscle cells of the mouse phrenic-nerve diaphragm preparation through similar mechanisms. Since the isoforms did not produce the expected summation in the increase in muscle twitch-tension, it is possible that they may have different affinities for the sodium channel subunits. 相似文献
28.
Emergency portacaval shunt for control of hemorrhage from a parenchymal fracture after adult-to-adult living donor liver transplantation 总被引:2,自引:0,他引:2
Marcos A Fisher RA Ham JM Olzinski AT Shiffman ML Sanyal AJ Luketic VA Sterling RK Posner MP 《Transplantation》2000,69(10):2218-2221
As more adults undergo transplantation with partial liver grafts, the unique features of these segments and their clinical significance will become apparent. A patient presented with life-threatening hemorrhage from an iatrogenic laceration to a right lobe graft 11 days after transplantation. The creation of a portacaval shunt effectively controlled the bleeding, allowing more elective replacement of the organ with another right lobe graft. The regeneration process combined with increased portal blood flow and relative outflow limitation may have set the stage for this complication. Any disruption of the liver parenchyma during transplantation should be securely repaired and followed cautiously. Portacaval shunting is an option for controlling hemorrhage from the liver in transplant recipients. The timely availability of a second organ was likely the ultimate determinant of survival for this patient. 相似文献
29.
Quinten M. VanderWerf Dan J. Castro Richard D. Nguyen Marcos B. Paiva Kuo H. Chao Mario E. Santillanes Romaine E. Saxton 《The Laryngoscope》1997,107(3):316-320
Neutral red (NR) is a cationic, nontoxic vital dye employed as a histologic stain for proliferating cells; it has been used clinically for photodynamic treatment of herpes simplex virus lesions. NR is selectively taken up and concentrated by mitotic cells, an important characteristic for more effective antineoplastic agents. In the present study, UCLA-SO-P3 human squamous carcinoma cells displayed minimal toxicity when incubated with up to 50 μg/ml NR in the absence of light. However, cells incubated with greater than 0.5μg/ml NR followed by exposure to KTP laser light at 532 nm exhibited nearly 100% tumor cell death. The degree of cell toxicity was proportional to NR dose and laser light fluence. This study demonstrates that NR is an excellent cancer cell photosensitizer in vitro, and, after adding additional in vivo preclinical testing, may prove to be a useful agent in photodynamic destruction of head and neck tumors. 相似文献
30.
P S F Barbosa A M C Martins A Havt Daniela O Toyama J S A M Evangelista D P P Ferreira P P Joazeiro Luis O S Beriam Marcos H Toyama M C Fonteles H S A Monteiro 《Toxicon》2005,46(4):376-386
Bothrops jararacussu myotoxin I (BthTx-I; Lys 49) and II (BthTX-II; Asp 49) were purified by ion-exchange chromatography and reverse phase HPLC. In this work we used the isolated perfused rat kidney method to evaluate the renal effects of B. jararacussu myotoxins I (Lys49 PLA2) and II (Asp49 PLA2) and their possible blockage by indomethacin. BthTX-I (5 microg/ml) and BthTX-II (5 microg/ml) increased perfusion pressure (PP; ct120=110.28+/-3.70 mmHg; BthTX I=171.28+/-6.30*mmHg; BthTX II=175.50+/-7.20*mmHg), renal vascular resistance (RVR; ct120=5.49+/-0.54 mmHg/ml.g(-1)min(-1); BthTX I=8.62+/-0.37*mmHg/ml g(-1)min(-1); BthTX II=8.9+/-0.36*mmHg/ml g(-1)min(-1)), urinary flow (UF; ct(120)=0.14+/-0.01ml g(-1)min(-1); BthTX I=0.32+/-0.05*ml g(-1)min(-1); BthTX II=0.37+/-0.01*ml g(-1)min(-1)) and glomerular filtration rate (GFR; ct120=0.72+/-0.10 ml g(-1)min(-1); BthTX I=0.85+/-0.13*ml g(-1)min(-1); BthTX II=1.22+/-0.28*ml g(-1)min(-1)). In contrast decreased the percent of sodium tubular transport (%TNa(+); ct(120)=79,76+/-0.56; BthTX I=62.23+/-4.12*; BthTX II=70.96+/-2.93*) and percent of potassium tubular transport (%TK(+);ct120=66.80+/-3.69; BthTX I=55.76+/-5.57*; BthTX II=50.86+/-6.16*). Indomethacin antagonized the vascular, glomerular and tubular effects promoted by BthTX I and it's partially blocked the effects of BthTX II. In this work also evaluated the antibacterial effects of BthTx-I and BthTx-II against Xanthomonas axonopodis. pv. passiflorae (Gram-negative bacteria) and we observed that both PLA2 showed antibacterial activity. Also we observed that proteins Also we observed that proteins chemically modified with 4-bromophenacyl bromide (rho-BPB) decrease significantly the antibacterial effect of both PLA2. In conclusion, BthTx I and BthTX II caused renal alteration and presented activity antimicrobial. The indomethacin was able to antagonize totally the renal effects induced by BthTx I and partially the effects promoted by BthTx II, suggesting involvement of inflammatory mediators in the renal effects caused by myotoxins. In the other hand, other effects could be independently of the enzymatic activity of the BthTX II and the C-terminal domain could be involved in both effects promoted for PLA2. 相似文献