全文获取类型
收费全文 | 1032篇 |
免费 | 61篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 51篇 |
妇产科学 | 23篇 |
基础医学 | 113篇 |
口腔科学 | 33篇 |
临床医学 | 64篇 |
内科学 | 217篇 |
皮肤病学 | 36篇 |
神经病学 | 68篇 |
特种医学 | 21篇 |
外科学 | 190篇 |
综合类 | 6篇 |
一般理论 | 2篇 |
预防医学 | 68篇 |
眼科学 | 43篇 |
药学 | 78篇 |
中国医学 | 1篇 |
肿瘤学 | 76篇 |
出版年
2023年 | 10篇 |
2022年 | 32篇 |
2021年 | 50篇 |
2020年 | 34篇 |
2019年 | 42篇 |
2018年 | 44篇 |
2017年 | 23篇 |
2016年 | 37篇 |
2015年 | 31篇 |
2014年 | 64篇 |
2013年 | 41篇 |
2012年 | 64篇 |
2011年 | 71篇 |
2010年 | 40篇 |
2009年 | 22篇 |
2008年 | 34篇 |
2007年 | 61篇 |
2006年 | 52篇 |
2005年 | 55篇 |
2004年 | 48篇 |
2003年 | 31篇 |
2002年 | 44篇 |
2001年 | 28篇 |
2000年 | 25篇 |
1999年 | 29篇 |
1998年 | 2篇 |
1997年 | 9篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1993年 | 5篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 9篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 6篇 |
1986年 | 9篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1973年 | 1篇 |
排序方式: 共有1098条查询结果,搜索用时 0 毫秒
1.
Julie A. Schmidt Georgina K. Fensom Sabina Rinaldi Augustin Scalbert Paul N. Appleby David Achaintre Audrey Gicquiau Marc J. Gunter Pietro Ferrari Rudolf Kaaks Tilman Kühn Heiner Boeing Antonia Trichopoulou Anna Karakatsani Eleni Peppa Domenico Palli Sabina Sieri Rosario Tumino Bas Bueno-de-Mesquita Antonio Agudo Maria-Jose Sánchez María-Dolores Chirlaque Eva Ardanaz Nerea Larrañaga Aurora Perez-Cornago Nada Assi Elio Riboli Konstantinos K. Tsilidis Timothy J. Key Ruth C. Travis 《International journal of cancer. Journal international du cancer》2020,146(3):720-730
Metabolomics may reveal novel insights into the etiology of prostate cancer, for which few risk factors are established. We investigated the association between patterns in baseline plasma metabolite profile and subsequent prostate cancer risk, using data from 3,057 matched case–control sets from the European Prospective Investigation into Cancer and Nutrition (EPIC). We measured 119 metabolite concentrations in plasma samples, collected on average 9.4 years before diagnosis, by mass spectrometry (AbsoluteIDQ p180 Kit, Biocrates Life Sciences AG). Metabolite patterns were identified using treelet transform, a statistical method for identification of groups of correlated metabolites. Associations of metabolite patterns with prostate cancer risk (OR1SD) were estimated by conditional logistic regression. Supplementary analyses were conducted for metabolite patterns derived using principal component analysis and for individual metabolites. Men with metabolite profiles characterized by higher concentrations of either phosphatidylcholines or hydroxysphingomyelins (OR1SD = 0.77, 95% confidence interval 0.66–0.89), acylcarnitines C18:1 and C18:2, glutamate, ornithine and taurine (OR1SD = 0.72, 0.57–0.90), or lysophosphatidylcholines (OR1SD = 0.81, 0.69–0.95) had lower risk of advanced stage prostate cancer at diagnosis, with no evidence of heterogeneity by follow-up time. Similar associations were observed for the two former patterns with aggressive disease risk (the more aggressive subset of advanced stage), while the latter pattern was inversely related to risk of prostate cancer death (OR1SD = 0.77, 0.61–0.96). No associations were observed for prostate cancer overall or less aggressive tumor subtypes. In conclusion, metabolite patterns may be related to lower risk of more aggressive prostate tumors and prostate cancer death, and might be relevant to etiology of advanced stage prostate cancer. 相似文献
2.
Jose M. Fernández-Cebrián Peter Vorwald Kuborn Mar Pardo de Lama Alfonso Sanjuanbenito Dehesa Manuel Nevado Santos Pedro A. Pacheco Martínez Beatriz Fernández-Escudero 《Clinical & translational oncology》2005,7(3):101-109
Colorectal cancer is one of the best studied of all malignant diseases interms of genetics and/or molecular prognostic factors. These factors, and relationships with prognosis, may have important implications especially in the design of surgical and adjuvant chemo-radiotherapy options. However, the true prognostic significance of all known factors has yet to be realised. We have reviewed the literature with specific focus on the role of molecular markers involved in prognosis and the prediction of response to adjuvant treatment. 相似文献
3.
Bradykinin-induced vasoconstriction of rat mesenteric arteries precontracted with noradrenaline. 总被引:4,自引:4,他引:0 下载免费PDF全文
1. Administration of bradykinin caused dose-dependent vasoconstriction in rat isolated perfused mesenteric arteries precontracted with noradrenaline. 2. The vasoconstrictor response was not mediated by BK1-bradykinin receptors. 3. Inhibition of cyclo-oxygenase with indomethacin, aspirin or meclofenamate abolished the vasoconstrictor effect of bradykinin, showing that a member of the arachidonic acid cascade may be involved. 4. Inhibitors of thromboxane synthesis (imidazole and UK 38485) did not affect or only reduced the bradykinin-induced vasoconstriction. 5. The endoperoxide H2/thromboxane A2 receptor antagonist SQ 29548 significantly reduced the vasoconstrictor effect of bradykinin, but did not affect the vasoconstrictor response to noradrenaline, adrenaline, vasopressin, 5-hydroxytryptamine or prostaglandins. 6. The eicosanoid(s) that mediate bradykinin-induced vasoconstriction appear to be synthesized outside the arterial endothelium. 7. The data suggest that the vasoconstrictor effect of bradykinin in the rat isolated mesenteric artery is mediated by vasoconstrictor arachidonic acid metabolites including the cyclic endoperoxides and/or the thromboxanes. 相似文献
4.
5.
Yildiz Oner-Iyido?an Pernur Oner Hikmet Ko?ak Abdul Lama Figen Gürd?l Selda? Bekpinar Nurettin Unur Zeynep Ozbek-Kir 《Pharmacological research》2005,52(4):340-345
Leukocyte arylsulphatase A (AS-A) was shown to be significantly high in newly-diagnosed breast cancer patients. Previous reports imply a connection between serum interleukin-6 (IL-6) and breast cancer, possibly through a modulation of enzymes involved in estrogen synthesis. Abnormal distribution of heparan sulphate proteoglycans (HSPGs) in malignant breast epithelial cells suggests that they play a key role in the regulation of cell growth. Estradiol is believed to be effective in modulating glycosaminoglycans (GAGs) and their depolymerizing enzymes. Therefore, in this study, attempts were made to evaluate the activity of leukocyte arylsulphatase A, serum interleukin-6, urinary GAGs and heparan sulphate (HS) in response to tamoxifen (TAM) therapy in mastectomised breast cancer patients. Thirty-four patients (aged 30-82 years) were administered TAM (20 mg twice daily). Blood and urine samples of each patient were collected three times (at the beginning, and in third and sixth month of TAM therapy), and biochemical parameters were measured. There was no difference between baseline leukocyte AS-A activity and that measured after three months. At the end of six months, enzyme activity was significantly higher than the former values (p=0.022), but within the reference intervals reported in the literature. Although this increase might imply a normalization, the duration of TAM therapy is not long enough to make a decision about either regression or aggravation of the disease. TAM did not have any effect on serum IL-6, urinary HS and GAG levels which may be due to insensitivity of these variables to TAM during the short period of therapy. Both urinary GAG and HS levels measured at sixth month exhibited a positive correlation with the baseline level of leukocyte AS-A (p=0.005 and 0.009, respectively), suggesting that positive responses to the drug might be seen in patients with low AS-A activity. 相似文献
6.
S F de Medeiros P E Assi M M W Y de Medeiros 《International journal of gynaecology and obstetrics》2004,87(1):24-28
OBJECTIVE: To evaluate the follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels in early follicular phase throughout the reproductive years. METHOD: FSH and LH concentrations were determined by radioimmunoassay (RIA). Linear and polynomial regressions were carried out considering basal FSH as the dependent and age as the independent variable. RESULTS: FSH levels increased throughout the reproductive years (P<0.025). A positive correlation between age and basal FSH levels was detected (P<0.05). The Pearson squared coefficient of r(2)=0.889 was obtained. Using polynomial regression, the inclination of the parabole (Y=7.97-0.009x+0.057x(2)) was 0.359 and the generalized correlation coefficient was r=0.795. The goodness of fit analysis showed that the parabole may better represent the phenomenon (F=4.7; P<0.05). The LH levels remained constant, increasing only beyond 40 years of age. CONCLUSION: The FSH levels rose in a nonlinear way during the reproductive life and the LH concentrations increased discreetly only in patients over 40 years of age. 相似文献
7.
Montano SM Sanchez JL Laguna-Torres A Cuchi P Avila MM Weissenbacher M Serra M Viñoles J Russi JC Aguayo N Galeano AH Gianella A Andrade R Arredondo A Ramirez E Acosta ME Alava A Montoya O Guevara A Manrique H Sanchez JL Lama JR de la Hoz F Sanchez GI Ayala C Pacheco ME Carrion G Chauca G Perez JJ Negrete M Russell KL Bautista CT Olson JG Watts DM Birx DL Carr JK;South American HIV Molecular Surveillance Working Group 《Journal of acquired immune deficiency syndromes (1999)》2005,40(1):57-64
HIV cross-sectional studies were conducted among high-risk populations in 9 countries of South America. Enzyme-linked immunosorbent assay screening and Western blot confirmatory testing were performed, and env heteroduplex mobility assay genotyping and DNA sequencing were performed on a subset of HIV-positive subjects. HIV prevalences were highest among men who have sex with men (MSM; 2.0%-27.8%) and were found to be associated with multiple partners, noninjection drug use (non-IDU), and sexually transmitted infections (STIs). By comparison, much lower prevalences were noted among female commercial sex workers (FCSWs; 0%-6.3%) and were associated mainly with a prior IDU and STI history. Env subtype B predominated among MSM throughout the region (more than 90% of strains), whereas env subtype F predominated among FCSWs in Argentina and male commercial sex workers in Uruguay (more than 50% of strains). A renewed effort in controlling STIs, especially among MSM groups, could significantly lessen the impact of the HIV epidemic in South America. 相似文献
8.
Dissociated ROS production and ceramide generation in sulfasalazine-induced cell death in Raw 264.7 cells 总被引:2,自引:0,他引:2
Salh B Assi K Huang S O'Brien L Steinbrecher U Gómez-Muñoz A 《Journal of leukocyte biology》2002,72(4):790-799
Sulfasalazine (SSZ) is a drug used in inflammatory bowel disease, whose precise mechanism of action remains to be clarified. Here, we report that incubation of Raw 264.7 cells with SSZ but not salicylates [acetylsalicylic acid (ASA), 4-aminosalicylic acid (4-ASA), and 5-ASA] causes a mixed apoptotic and necrotic form of cell death. In contrast to its metabolites, sulfapyridine and 5-ASA, SSZ exposure in Raw 264.7 cells resulted in a threefold increase in ceramide generation, as well as a robust production of reactive oxygen species (ROS). However, inhibition of ceramide production by fumonisin B1 failed to attenuate cell death. Preincubation with catalase, cyclosporin A (CsA), and bongkrekic acid attenuated ROS production. When dead cells were quantified for apoptotic versus necrotic cell death, catalase and N-acetylcysteine reproducibly attenuated apoptosis, whereas CsA, in addition to reducing apoptosis, was observed to dramatically enhance necrosis. In conclusion, the cell-death response induced by SSZ in Raw 264.7 cells involves ROS in the apoptotic limb but is independent of ceramide formation. 相似文献
9.
Ventura MT Munno G Giannoccaro F Accettura F Chironna M Lama R Hoxha M Panetta V Ferrigno L Rosmini F Matricardi PM Barbuti S Priftanji A Bonini S Tursi A 《Allergy》2004,59(6):632-636
BACKGROUND: Studies of immigrants represent an useful tool to determine the relative relevance of environmental vs genetic factors in causing the reported rapid increase of the prevalence of sensitization and allergic diseases. METHODS: A total of 152 Albanian migrants to Southern Italy responded to a questionnaire based on the European Community Respiratory Health Survey (ECRHS) and 139 of them underwent skin prick test, and 61 serological assays for total IgE and IgG antibodies against Toxoplasma gondii (TG), herpes simplex virus 1 (HSV-1), hepatitis A virus (HAV) and Helicobacter pylori (HP). RESULTS: Reported asthma was rare (2/152; 1.3%) and reported nasal allergies rather frequent (24/152; 15.8%). Sensitization to common inhalant allergens occurred in 27/139 (19.4%) subjects. The frequency of skin sensitization to pollen (P = 0.003) and that of hay fever (P = 0.004) increased with the time spent in Apulia. All the 61 sera had antibodies against HAV, 59/61 (96.7%) against HSV-1, 48/61 (78.7%) against HP and 34/61 (55.7%) against TG. The prevalence of skin sensitization and hay fever symptoms were correlated to the duration of residence in Southern Italy. CONCLUSIONS: Data presented indicate that Albanian migrants to Italy, in spite of the low prevalence of allergic diseases and sensitization in their country of origin, manifest with time an increasing prevalence of sensitization to local allergens and nasal symptoms after immigration to Italy. This would suggest a permanent role of allergen exposure and lifestyle factors in influencing the appearance of sensitization and symptoms of allergic diseases. 相似文献
10.
Abdullah Saleh AlQattan MBBS Weaam Zohier Ghulam MBBS Najla Aldaoud MBBS Lama Algheryafi MBBS Nadia Aleisa MBBS Fozan A. Aldulaijan MBBS 《The breast journal》2021,27(3):258-263
Breast fat necrosis (BFN) is usually a benign inflammatory response to breast trauma. However, an extremely rare cause of fat necrosis is calciphylaxis, a calcification of small- and medium-sized arteries causing thrombosis and ischemia. It is classified into (A) uremic (B) nonuremic-induced calciphylaxis. Calciphylaxis has been reported to be encountered in different parts of the body. However, to the best of our knowledge there is only one case in the English literature of BFN 2ry to warfarin-induced calciphylaxis. We report a 65-year-old female, known case of atrial fibrillation on warfarin, presented with a left breast mass of 4-month duration. The mass was painful and progressively enlarging. Examination of the left breast showed 7 × 4 cm mass, spanning from 10-2 o'clock, free from surrounding structures, with preserved overlying skin. However, the mass was not visualized on mammogram. Ultrasound showed a left breast lobulated hypoechoic mass containing a hyperechoic component. Biopsy showed fat necrosis. After 1 month, she presented with ulceration of the overlying skin. After wide local excision, histopathology demonstrated a calciphylaxis-induced fat necrosis. Considering the patient's background, the diagnosis was BFN secondary to warfarin-induced calciphylaxis. Hence, the warfarin was shifted to Rivaroxaban, 6 months follow-up showed no evidence of recurrence. In conclusion, the rarity of nonuremic calciphylaxis is reflected on the delay of diagnosis in some of the reported cases and the lack of grading system used to guide the management of such difficult wounds. However, keeping a high index of suspicion is important whenever such wounds are encountered with presence of risk factors other than end-stage kidney disease. 相似文献