全文获取类型
收费全文 | 7335篇 |
免费 | 556篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 113篇 |
儿科学 | 253篇 |
妇产科学 | 145篇 |
基础医学 | 1056篇 |
口腔科学 | 462篇 |
临床医学 | 558篇 |
内科学 | 1531篇 |
皮肤病学 | 175篇 |
神经病学 | 511篇 |
特种医学 | 267篇 |
外科学 | 987篇 |
综合类 | 64篇 |
一般理论 | 2篇 |
预防医学 | 704篇 |
眼科学 | 233篇 |
药学 | 429篇 |
中国医学 | 49篇 |
肿瘤学 | 381篇 |
出版年
2023年 | 44篇 |
2022年 | 113篇 |
2021年 | 192篇 |
2020年 | 138篇 |
2019年 | 179篇 |
2018年 | 244篇 |
2017年 | 170篇 |
2016年 | 201篇 |
2015年 | 237篇 |
2014年 | 314篇 |
2013年 | 370篇 |
2012年 | 522篇 |
2011年 | 503篇 |
2010年 | 333篇 |
2009年 | 255篇 |
2008年 | 380篇 |
2007年 | 369篇 |
2006年 | 357篇 |
2005年 | 321篇 |
2004年 | 307篇 |
2003年 | 300篇 |
2002年 | 201篇 |
2001年 | 159篇 |
2000年 | 156篇 |
1999年 | 153篇 |
1998年 | 80篇 |
1997年 | 70篇 |
1996年 | 75篇 |
1995年 | 73篇 |
1994年 | 50篇 |
1993年 | 53篇 |
1992年 | 91篇 |
1991年 | 86篇 |
1990年 | 83篇 |
1989年 | 75篇 |
1988年 | 82篇 |
1987年 | 70篇 |
1986年 | 75篇 |
1985年 | 68篇 |
1984年 | 40篇 |
1983年 | 34篇 |
1982年 | 19篇 |
1981年 | 25篇 |
1980年 | 17篇 |
1979年 | 27篇 |
1977年 | 20篇 |
1976年 | 16篇 |
1975年 | 18篇 |
1973年 | 17篇 |
1972年 | 16篇 |
排序方式: 共有7920条查询结果,搜索用时 15 毫秒
91.
92.
This is a prospective interventional clinical study evaluating intraocular inflammation developed after Ultrasound Cyclo Plasty (UCP) for the treatment of glaucoma. Eighteen eyes of 18 patients were treated with UCP second-generation probes (Eye OP1). After treatment, the mean intraocular pressure (IOP) significantly decreased from 26.8±7.2 to 18.8±6.1 mm Hg at day 1 and to 14.7±3.4 mm Hg at month 6 (all P<0.001). Mean laser flare-cell photometry value steeply increased after surgery from 12.1±7.5 to 64.1±53.9 ph/ms (P=0.001) at day 1, and then progressively decreased to respectively 60.6±49.7 at day 7, 43.5±38.5 at day 14 and 28.2±18.3 at month 1 (all P<0.05), returning at levels similar to baseline ones at month 3 and month 6 (respectively 16.7±6.2 and 12.8±10.2, both P>0.05). A significant negative correlation was found between postoperative increase of aqueous flare values and anterior chamber depth (R=-0.568, P=0.014). This timeframe may be considered reasonable for repeating UCP treatment, when required. 相似文献
93.
94.
Vaccination Decreases the Infectious Viral Load of Delta Variant SARS-CoV-2 in Asymptomatic Patients
Jessica A. Plante Rafael R. G. Machado Brooke M. Mitchell Divya P. Shinde Jordyn Walker Dionna Scharton Allan McConnell Nehad Saada Jianying Liu Bilal Khan Rafael K. Campos Bryan A. Johnson Vineet D. Menachery Corri B. Levine Ping Ren Susan L. F. McLellan Kenneth S. Plante Scott C. Weaver 《Viruses》2022,14(9)
The Delta variant of SARS-CoV-2 has caused many breakthrough infections in fully vaccinated individuals. While vaccine status did not generally impact the number of viral RNA genome copies in nasopharyngeal swabs of breakthrough patients, as measured by Ct values, it has been previously found to decrease the infectious viral load in symptomatic patients. We quantified the viral RNA, infectious virus, and anti-spike IgA in nasopharyngeal swabs collected from individuals asymptomatically infected with the Delta variant of SARS-CoV-2. Vaccination decreased the infectious viral load, but not the amount of viral RNA. Furthermore, vaccinees with asymptomatic infections had significantly higher levels of anti-spike IgA in their nasal secretions compared to unvaccinated individuals with asymptomatic infections. Thus, vaccination may decrease the transmission risk of Delta, and perhaps other variants, despite not affecting the amount of viral RNA measured in nasopharyngeal swabs. 相似文献
95.
Marina Weiler Raphael F. Casseb Brunno M. de Campos Julia S. Crone Evan S. Lutkenhoff Paul M. Vespa Martin M. Monti for the EpiBioSRx Study Group 《Human brain mapping》2022,43(15):4640
Resting‐state functional MRI is increasingly used in the clinical setting and is now included in some diagnostic guidelines for severe brain injury patients. However, to ensure high‐quality data, one should mitigate fMRI‐related noise typical of this population. Therefore, we aimed to evaluate the ability of different preprocessing strategies to mitigate noise‐related signal (i.e., in‐scanner movement and physiological noise) in functional connectivity (FC) of traumatic brain injury (TBI) patients. We applied nine commonly used denoising strategies, combined into 17 pipelines, to 88 TBI patients from the Epilepsy Bioinformatics Study for Anti‐epileptogenic Therapy clinical trial. Pipelines were evaluated by three quality control (QC) metrics across three exclusion regimes based on the participant''s head movement profile. While no pipeline eliminated noise effects on FC, some pipelines exhibited relatively high effectiveness depending on the exclusion regime. Once high‐motion participants were excluded, the choice of denoising pipeline becomes secondary ‐ although this strategy leads to substantial data loss. Pipelines combining spike regression with physiological regressors were the best performers, whereas pipelines that used automated data‐driven methods performed comparatively worse. In this study, we report the first large‐scale evaluation of denoising pipelines aimed at reducing noise‐related FC in a clinical population known to be highly susceptible to in‐scanner motion and significant anatomical abnormalities. If resting‐state functional magnetic resonance is to be a successful clinical technique, it is crucial that procedures mitigating the effect of noise be systematically evaluated in the most challenging populations, such as TBI datasets. 相似文献
96.
Campos DA de Lima AF Ribeiro SR Silveira ER Pessoa OD Rao VS Santos FA 《The Journal of pharmacy and pharmacology》2008,60(3):391-397
The gastroprotective effect of DDF (3,6-dimethoxy-6', 6'-dimethyl-[2', 3' : 7,8]-chromeneflavone) from Lonchocarpus araripensis Benth. (Leguminosae) on gastric damage induced by absolute ethanol (96%, 0.2 mL/mouse) and indometacin (30 mg kg(-1), p.o.) in mice was investigated. Intraperitoneally administered DDF at dose levels of 50, 100 and 200 mg kg(-1) markedly reduced the gastric lesions in the ethanol model by 62, 72 and 96%, and in the indometacin model by 34, 70 and 75%, respectively, as compared with misoprostol (50 microg kg(-1), p.o.), the reference compound that caused lesion suppression by 67% in ethanol model and by 72% against indometacin-induced ulceration. The ED50 of DDF in reducing gastric lesions induced by ethanol and indometacin (dose of the DDF that reduced the gastric lesion area by 50% in relation to the control value) was 50.87 and 61.56 mg kg(-1), respectively. Mechanistic studies were carried out at 100 mg kg(-1) DDF using the ethanol model. Compared with N-acetylcysteine (750 mg kg(-1), p.o.), a donor of sulfhydryls, DDF only partially replenished the ethanol-induced depletion of gastric mucosal NP-SH. Pretreatment with TRPV1 antagonist capsazepine (5 mg kg(-1), i.p.) or the non-selective cyclooxygenase inhibitor indometacin (10 mg kg(-1), p.o.) effectively blocked the gastroprotective effect of DDF (100 mg kg(-1)) against ethanol damage. Furthermore, the effect of DDF was significantly reduced in mice pretreated with L-NAME, or glibenclamide, the respective inhibitors of nitric oxide synthase and K+ ATP channel activation. These data provide evidence to show that DDF affords gastroprotection against gastric damage induced by ethanol and indometacin by different and complementary mechanisms, which include involvement of endogenous prostaglandins, nitric oxide release, the activation of TRPV1 receptor or K+ ATP channels, besides a sparing effect on NP-SH reserve. 相似文献
97.
98.
Gilberto Campos Guimares Filho Lucas Tavares Silva Ruth Mellina Castro e Silva 《Arquivos brasileiros de cardiologia》2022,119(2):257
Background:Arterial stiffness is a strong predictor of cardiovascular disease (CVD). Body fat measures such as waist circumference (WC) have been associated with CVD in adulthood.Objectives:The objective of this study was to evaluate the association of arterial stiffness, measured by applanation tonometry-Sphygmocor, with WC.Methods:Observational study with 240 participants who make routine consultations at the outpatient clinic of a university hospital. Participants were interviewed and had central blood pressure measurements (CBPM), anthropometric parameters, abdominal fat and visceral fat measured. Paired and unpaired t and chi-square tests were used. A significance level of 5% was adopted.Results:Of the 240 participants, 51.82% were male with a mean age of 59.71(±14.81) years and a mean WC of 99.87 (11.54) cm. Mean CBPM values were: Central arterial pressure (CAP) = 130.23 (91-223) mmHg, pulse wave velocity (PWV) = 9.8 (5.28-19.6)m/s and Augmentation Index [Amplification Index (AI)] = 29.45 (-14-60). PWV and CAP were highly correlated with WC with p<0.001 and p=0.02, respectively; however, the same positive correlation was not found between WC and AI (p=0.06).Conclusion:The present study showed a positive association between WC and arterial stiffness, through the femoral carotid pulse wave velocity (cf-PWV) and AI, being stronger with cf-PWV, suggesting the evaluation of the effect of WC in vascular health as a method of aid in the early treatment of CVD and in the prevention of clinical outcomes. 相似文献
99.
Tatiane Teixeira Oliveira Keina Maciele Campos Ana Tereza Cerqueira-Lima Tamires Cana Brasil Carneiro Eudes da Silva Velozo Ingrid Christie Alexandrino Ribeiro Melo Eugênia Abrantes Figueiredo Eduardo de Jesus Oliveira Darizy Flávia Silva Amorim de Vasconcelos Lain Carlos Pontes-de-Carvalho Neuza Maria Alcantara-Neves Camila Alexandrina Figueiredo 《Daru : journal of Faculty of Pharmacy, Tehran University of Medical Sciences》2015,23(1)
Background
Asthma is an inflammatory condition characterized by airway hyperresponsiveness and chronic inflammation. The resolution of inflammation is an essential process to treat this condition. In this study we investigated the effect of Allium cepa L. extract (AcE) and quercetin (Qt) on cytokine and on smooth muscle contraction in vitro and its therapeutic potential in a murine model of asthma.Methods
AcE was obtained by maceration of Allium cepa L. and it was standardized in terms of quercetin concentration using high performance liquid chromatography (HPLC). In vitro, using AcE 10, 100 or 1000 μg/ml or Qt 3.5, 7.5, 15 μg/ml, we measured the concentration of cytokines in spleen cell culture supernatants, and the ability to relax tracheal smooth muscle from A/J mice. In vivo, Blomia tropicalis (BT)-sensitized A/J mice were treated with AcE 100, 1000 mg/kg or 30 mg/kg Qt. We measured cell influx in bronchoalveolar lavage (BAL), eosinophil peroxidase (EPO) in lungs, serum levels of Bt-specific IgE, cytokines levels in BAL, and lung histology.Results
We observed a reduction in the production of inflammatory cytokines, a relaxation of tracheal rings, and a reduction in total number of cells in BAL and EPO in lungs by treatment with AcE or Qt.Conclusion
AcE and Qt have potential as antiasthmatic drugs, as they possess both immunomodulatory and bronchodilatory properties. 相似文献100.
Michela Fresina Anna Dickmann Annabella Salerni Fabio De Gregorio Emilio C. Campos 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2008,246(1):143-150
Purpose The purpose of the study was to evaluate the effect on visual function of orally administered CDP-choline in addition to patching
for the treatment of amblyopia in children.
Methods This was an open label parallel group study comparing patching plus oral CDP-choline with patching alone. Sixty-one participants
(aged between 5 and 10 years) suffering from anisometropic or strabismic amblyopia were divided at random into two groups:
Group A, 800 or 1,200 mg (according to the body weight) of orally administered CDP-choline and 2-h patching a day; Group B,
2-h patching a day. Both groups were treated for 30 consecutive days. A follow-up visit was set 60 days after the treatment
was discontinued. The main outcome measure was the change in visual acuity of amblyopic eyes as measured by Snellen’s E charts.
The secondary outcome measures were changes in the visual acuity of amblyopic eye as measured by isolated letters (Snellen’s
E) and changes in the contrast sensitivity of amblyopic eyes.
Results The addition of CDP-choline to patching therapy was not found to be more effective than patching alone after 30-day treatment.
The present results showed that adding CDP-choline to patching stabilised the effects obtained during the treatment period.
In fact, whereas the participants treated only with patching showed a decrease in visual acuity at 90 days, these receiving
CDP-choline and patching combined appeared to maintain the results obtained (two-way ANOVA: P = 0.0042). Similar results were obtained when measuring visual acuity by isolated Snellen’s E letters.
Conclusions In amblyopic patients, CDP-choline combined with patching contributes to obtaining more stable effects than patching alone.
Fabio De Gregorio works as an advisor for Tubilux Pharma S.p.A.
The authors have full control of all primary data and they agree to allow Graefe’s Archives for Clinical and Experimental Ophthalmology to review their data if requested. 相似文献