全文获取类型
收费全文 | 10075篇 |
免费 | 628篇 |
国内免费 | 81篇 |
专业分类
耳鼻咽喉 | 74篇 |
儿科学 | 263篇 |
妇产科学 | 262篇 |
基础医学 | 1417篇 |
口腔科学 | 142篇 |
临床医学 | 783篇 |
内科学 | 2596篇 |
皮肤病学 | 132篇 |
神经病学 | 1472篇 |
特种医学 | 392篇 |
外科学 | 894篇 |
综合类 | 16篇 |
一般理论 | 4篇 |
预防医学 | 465篇 |
眼科学 | 131篇 |
药学 | 772篇 |
中国医学 | 10篇 |
肿瘤学 | 959篇 |
出版年
2024年 | 26篇 |
2023年 | 168篇 |
2022年 | 290篇 |
2021年 | 498篇 |
2020年 | 270篇 |
2019年 | 382篇 |
2018年 | 417篇 |
2017年 | 313篇 |
2016年 | 373篇 |
2015年 | 384篇 |
2014年 | 551篇 |
2013年 | 629篇 |
2012年 | 829篇 |
2011年 | 869篇 |
2010年 | 502篇 |
2009年 | 453篇 |
2008年 | 633篇 |
2007年 | 581篇 |
2006年 | 570篇 |
2005年 | 501篇 |
2004年 | 363篇 |
2003年 | 311篇 |
2002年 | 282篇 |
2001年 | 55篇 |
2000年 | 46篇 |
1999年 | 64篇 |
1998年 | 55篇 |
1997年 | 38篇 |
1996年 | 38篇 |
1995年 | 26篇 |
1994年 | 25篇 |
1993年 | 16篇 |
1992年 | 19篇 |
1991年 | 26篇 |
1990年 | 24篇 |
1989年 | 27篇 |
1988年 | 29篇 |
1987年 | 16篇 |
1986年 | 14篇 |
1985年 | 10篇 |
1984年 | 7篇 |
1983年 | 9篇 |
1982年 | 3篇 |
1981年 | 8篇 |
1980年 | 6篇 |
1979年 | 9篇 |
1978年 | 6篇 |
1977年 | 2篇 |
1967年 | 3篇 |
1966年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Silvana Chiara Maria Teresa Nobile Maura Vincenti Rita Lionetto Alberto Gozza Maria Cristina Barzacchi Ornella Sanguineti Lazzaro Repetto Riccardo Rosso 《Cancer chemotherapy and pharmacology》1998,42(4):336-340
To evaluate toxicity and efficacy of chemotherapy in elderly patients (≥65 years of age) with advanced colorectal cancer,
data from two consecutive trials conducted between 1984 and 1995 at the National Institute for Cancer Research were analysed
comparing the results of treatment in those 65 years of age or older and in those younger than 65 years. Of 215 patients recruited,
82 elderly patients (median age 70 years, median performance status 1) received one of the following regimens based on 5-fluorouracil
(5-FU): (1) weekly 5-FU 600 mg/m2 i.v. bolus (30 patients); (2) weekly 5-FU 600 mg/m2 bolus plus leucovorin (LV) 500 mg/m2 2-h i.v. infusion (28 patients); (3) Weekly 5-FU 2600 mg/m2 24-h continuous i.v. infusion plus LV 100 mg 4-h i.v. infusion and 50 mg orally every 4 h for five doses (24 patients). Overall,
1071 chemotherapy cycles were administered with a median number of 12 courses per patient. The main side effects were diarrhoea,
observed in 38% of patients, stomatitis in 24% of patients and hand-foot syndrome in 13% of patients, and haematological toxicity
affected only 15% of patients. No patient suffered grade IV toxicity. In three patients chemotherapy was discontinued because
of toxicity (two patients suffered grade III diarrhoea, one patient grade III hand-foot syndrome). No significant difference
in toxicity was evident between patients older than or younger than 65 years. Analysis of median dose intensity demonstrated
no difference between the two groups. Overall objective response was observed in 18% (95% confidence limits 11–29) of elderly
patients (15/82) in comparison with 23% (95% CL 17–32) of patients <65 years of age (31/133 pts). In conclusion, chemotherapy
in elderly patients with advanced colorectal cancer is a safe and effective treatment with acceptable toxicity and comparable
objective response rates.
Received: 6 January 1998 / Accepted: 27 February 1998 相似文献
92.
Chiara Zuccato Marzia Tartari Donato Goffredo Elena Cattaneo Dorotea Rigamonti 《Pharmacological research》2005,52(3):245-251
Treatment of neurodegenerative diseases represents a major challenge for the pharmaceutical industry. Key to developing novel and efficacious therapeutics is the discovery of new druggable targets. Toward this aim, the current drug discovery process is strongly relying on the improved understanding of disease mechanisms and on a synergistic approach with chemistry, molecular biology and robotics. In this scenario, we present the case of a newly discovered molecular mechanism that may be of interest for drug discovery programmes in Huntington's disease and other neurodegenerative diseases. 相似文献
93.
Domenico Acanfora Maria Nolano Chiara Acanfora Camillo Colella Vincenzo Provitera Giuseppe Caporaso Gabriele Rosario Rodolico Alessandro Santo Bortone Gennaro Galasso Gerardo Casucci 《Viruses》2022,14(5)
Long-COVID-19 refers to the signs and symptoms that continue or develop after the “acute COVID-19” phase. These patients have an increased risk of multiorgan dysfunction, readmission, and mortality. In Long-COVID-19 patients, it is possible to detect a persistent increase in D-Dimer, NT-ProBNP, and autonomic nervous system dysfunction. To verify the dysautonomia hypothesis in Long-COVID-19 patients, we studied heart rate variability using 12-lead 24-h ECG monitoring in 30 Long-COVID-19 patients and 20 No-COVID patients. Power spectral analysis of heart rate variability was lower in Long-COVID-19 patients both for total power (7.46 ± 0.5 vs. 8.08 ± 0.6; p < 0.0001; Cohens-d = 1.12) and for the VLF (6.84 ± 0.8 vs. 7.66 ± 0.6; p < 0.0001; Cohens-d = 1.16) and HF (4.65 ± 0.9 vs. 5.33 ± 0.9; p = 0.015; Cohens-d = 0.76) components. The LF/HF ratio was significantly higher in Long-COVID-19 patients (1.46 ± 0.27 vs. 1.23 ± 0.13; p = 0.001; Cohens-d = 1.09). On multivariable analysis, Long-COVID-19 is significantly correlated with D-dimer (standardized β-coefficient = 0.259), NT-ProBNP (standardized β-coefficient = 0.281), HF component of spectral analysis (standardized β-coefficient = 0.696), and LF/HF ratio (standardized β-coefficient = 0.820). Dysautonomia may explain the persistent symptoms in Long COVID-19 patients. The persistence of a procoagulative state and an elevated myocardial strain could explain vagal impairment in these patients. In Long-COVID-19 patients, impaired vagal activity, persistent increases of NT-ProBNP, and a prothrombotic state require careful monitoring and appropriate intervention. 相似文献
94.
Alessandra Andrisani Gabriella Donà Chiara Sabbadin Stefano Dall'Acqua Elena Tibaldi Antonella Roveri 《Gynecological endocrinology》2017,33(12):928-932
Endometriosis, an estrogen-dependent chronic gynecological disease in women of reproductive age, is characterized by a systemic inflammation status involving also red blood cells (RBCs). In this study, we evaluated how the protein oxidative status could be involved in the worsening of RBC conditions due to dapsone intake in endometriotic women in potential treatment for skin or infection diseases. Blood samples from two groups of volunteers, control group (CG) and endometriosis patient group (PG), were analyzed for their content of band 3 tyrosine phosphorylation (Tyr-P) and high molecular weight aggregate (HMWA) in membranes, and glutathione (GSH) content and carbonic anhydrase (CA) activity in cytosol. In endometriotic patients, RBC showed the highest level of oxidative-related alterations both in membrane and cytosol. More interestingly, the addition of dapsone hydroxylamine (DDS-NHOH) could induce further increase of both membranes and cytosol markers, with an enhancement of CA activity reaching about 66% of the total cell enzyme amount. In conclusion, in PG the systemic inflammatory status leads to the inability of counteracting adjunctive oxidative stress, with a potential involvement of CA-related pathologies, such as glaucoma. Hence, the importance of the evaluation of therapeutic approaches worsening oxidative imbalance present in PG RBC is underlined. 相似文献
95.
Manconi M Valenti D Sinico C Lai F Loy G Fadda AM 《International journal of pharmaceutics》2003,260(2):261-272
In this work, we compared the chemical stability of tretinoin (TRA) in methanol and in vesicular suspensions exposed both to UV and artificial daylight conditions with the aim of evaluating the potential of niosomes as topical carriers capable of improving the stability of photosensitive drugs. Tretinoin-loaded niosomes were prepared from polyoxyethylene (4) lauryl ether (Brij® 30), sorbitan esters (Span® 40 and Span®60) and a commercial mixture of octyl/decyl polyglucosides (Triton® CG110). Liposomes made from hydrogenated (P90H) and non-hydrogenated (P90) soy phosphatidylcholines were also prepared and studied. In order to evaluate the influence of vesicle structure on the photostability of tretinoin, TRA-loaded vesicles were prepared by the film hydration method, extrusion technique and sonication. After UV irradiation, TRA dissolved in methanol degraded very quickly while the incorporation in vesicles always led to a reduction of the photodegradation process. The photoprotection offered by vesicles varied depending on the vesicle structure and composition. After fluorescent light irradiation for 21 days, not all the studied vesicular formulations improved TRA stability when compared with the free drug in methanol. Tretinoin incorporated in P90 or Span vesicles presented a half-life shorter or very close to that of the free drug. However, the inclusion of TRA in P90H liposomes and Brij® 30 or Triton® CG110 niosomes retarded the drug photodegradation. 相似文献
96.
Rationale:Whereas metronidazole-induced hepatotoxicity is quite rare in the general population, in individuals carrying a nucleotide excision repair disorder, namely Cockayne syndrome, there is a high risk of developing this complication.Patient concerns:We report the case of a 44-year-old man, affected by xeroderma pigmentosum, who was admitted to the hospital presenting aspiration pneumoniae caused by worsening dysphagia and with severe hepatotoxicity during the hospitalization.Diagnoses:Acute hepatitis, which was leading to acute liver failure, occurred during antibiotic treatment with metronidazole and ceftazidime with an elevation of liver enzymes consistent with hepatocellular damage pattern.Interventions:Hydration with glucose 5% solution, pantoprazole and vitamin K were administered, meanwhile other causes of hepatitis were ruled out and the ongoing antibiotic treatment was stopped suspecting a drug-induced liver injury.Outcomes:Liver function nearly completely recovered 1 month later with a first rapid improvement, within few days, of aminotransferases and coagulation studies, and slower of cholestatic enzymes.Lessons:We describe the first case available in the literature of hepatotoxicity associated with metronidazole treatment in a xeroderma pigmentosum patient. Clinicians therefore, based on this report and according to the possible underlying mechanism shared by other genetic diseases characterized by alterations in the pathway of DNA-repair, should consider such adverse event also in patients affected by this rare disease. 相似文献
97.
Alessandra Vergori Antonio Boschini Stefania Notari Patrizia Lorenzini Concetta Castilletti Francesca Colavita Giulia Matusali Eleonora Tartaglia Roberta Gagliardini Andrea Boschi Eleonora Cimini Markus Maeurer Pierluca Piselli Leila Angeli Andrea Antinori Chiara Agrati Enrico Girardi 《Viruses》2022,14(7)
The main aim of this study was to describe the clinical and immunological outcomes, as well as the inflammatory profile, of patients with advanced HIV in an assisted-living facility in which an outbreak of SARS-CoV-2 occurred. SARS-CoV-2 humoral and specific T-cell response were analyzed in patients with HIV infection and COVID-19; as a secondary objective of the analysis, levels of the inflammatory markers (IL-1β, IL-6, IL-8, and TNFα) were tested in the HIV/COVID-19 group, in HIV-positive patients without COVID-19, and in HIV-negative patients with mild/moderate COVID-19. Antibody kinetics and ability to neutralize SARS-CoV-2 were evaluated by ELISA assay, as well as the inflammatory cytokines; SARS-CoV-2 specific T-cell response was quantified by ELISpot assay. Mann–Whitney or Kruskal–Wallis tests were used for comparisons. Thirty patients were included with the following demographics: age, 57 years old (IQR, 53–62); 76% male; median HIV duration of infection, 18 years (15–29); nadir of CD4, 57/mmc (23–100) current CD4 count, 348/mmc (186–565). Furthermore, 83% had at least one comorbidity. The severity of COVID-19 was mild/moderate, and the overall mortality rate was 10% (3/30). Additionally, 90% of patients showed positive antibody titers and neutralizing activity, with a 100% positive SARS-CoV-2 specific T-cell response over time, suggesting the ability to induce an effective specific immunity. Significantly higher levels of IL-6, IL-8, and TNF-α in COVID-19 without HIV vs. HIV/COVID-19 patients (p < 0.05) were observed. HIV infection did not seem to negatively impact COVID-19-related inflammatory state and immunity. Further data are mandatory to evaluate the persistence of these immunity and its ability to expand after exposure and/or vaccination. 相似文献
98.
Metformin Decreases Circulating Androgen and Estrogen Levels in Nondiabetic Women With Breast Cancer
Carlo Campagnoli Franco Berrino Elisabetta Venturelli Chiara Abbà Nicoletta Biglia Tiziana Brucato Patrizia Cogliati Saverio Danese Michela Donadio Gianna Zito Patrizia Pasanisi 《Clinical breast cancer》2013,13(6):433-438
IntroductionDiabetic patients treated with metformin have a lower risk of developing BC or a better BC prognosis. Metformin might reduce cancer growth through direct antiproliferative effects or through indirect mechanisms, particularly the reduction of insulin. In a randomized study on nondiabetic BC patients in natural menopause with high testosterone levels, we observed a significant decrease in insulin and in testosterone levels with metformin 1500 mg/d compared with 1000 mg/d. We present the results of a new analysis of our study on the effect of metformin on the bioavailability of sex hormones.Patients and MethodsOne hundred twenty-four eligible women were initially invited to take metformin 500 mg/d for 3 months. The 108 women who completed the first 3 months continued the study using 1000 mg/d for 1 month. The women were then randomized into 2 groups, and, for the subsequent 5 months, 1 group increased the dose to 1500 mg/d, and the other group continued with 1000 mg/d.ResultsNinety-six women completed the study, 43 receiving metformin 1500 mg/day, and 53 receiving 1000 mg/day. The women receiving 1500 mg/d showed a greater and significant reduction of free testosterone (?29%) and estradiol (?38%), a borderline significant reduction of estrone and insulin-like growth factor-1, and a nonsignificant reduction of androstenedione. They also showed a nonsignificant increase of dehydroepiandrosterone sulfate.ConclusionMetformin does not interfere with the production of dehydroepiandrosterone sulfate. Besides, it decreases estradiol levels, basically through the reduction of testosterone. These hormonal changes might have clinical relevance. 相似文献
99.
The role of apical vaginal support in the appearance of anterior and posterior vaginal prolapse 总被引:2,自引:0,他引:2
Lowder JL Park AJ Ellison R Ghetti C Moalli P Zyczynski H Weber AM 《Obstetrics and gynecology》2008,111(1):152-157
OBJECTIVE: To describe how simulated apical support affects the appearance of prolapse in the anterior and posterior vagina using a modification of the Pelvic Organ Prolapse Quantification (POP-Q) examination. METHODS: Women with prolapse stage II or greater were examined using the POP-Q. To simulate apical support, the posterior blade of a standard Graves speculum was positioned over the posterior vagina to support the vaginal apex while remeasuring points Aa and Ba and over the anterior vagina to support the apex while remeasuring points Ap and Bp. Change in anterior and posterior POP-Q points and prolapse stage with apical support were calculated. RESULTS: One hundred ninety-seven women were enrolled with mean age of 62+/-14 years, median parity of 2 (range 0-8), and mean body mass index of 28+/-5 kg/m(2). By standard POP-Q, 36% had stage II prolapse, 54% had stage III, and 10% had stage IV prolapse. With simulated apical support, point Ba changed to stage 0 or I in 55% of cases and point Bp changed to stage 0 or I in 30% (P<.001 for each point). Mean change for point Ba with apical support was 3.5+/-2.6 cm and point Bp was 1.9+/-2.9 cm (P<.001). CONCLUSION: When the POP-Q examination is performed with simulated apical support, the critical role of level I vaginal support on the position of the anterior and posterior vagina, particularly the anterior vagina, becomes apparent. LEVEL OF EVIDENCE: II. 相似文献
100.
The current study examines the predictors of three types of problem-focused coping strategies (i.e., amount of help seeking, pursuing an order of protection, and staying away from the abuser) among battered women. Predictor variables are categorized as abuse characteristics and three types of coping resources (i.e., personal, material, and social coping resources). Data from the Chicago Women's Health Risk Study (N=478) are used. Results show that enactment of problem-focused coping strategies is associated with amount of abuse, severity, harassment, and power and control tactics. Coping resources such as general health, employment, and social support influence enactment of coping strategies. 相似文献