全文获取类型
收费全文 | 8898篇 |
免费 | 703篇 |
国内免费 | 36篇 |
专业分类
耳鼻咽喉 | 24篇 |
儿科学 | 250篇 |
妇产科学 | 199篇 |
基础医学 | 1625篇 |
口腔科学 | 71篇 |
临床医学 | 865篇 |
内科学 | 1998篇 |
皮肤病学 | 201篇 |
神经病学 | 1036篇 |
特种医学 | 241篇 |
外科学 | 875篇 |
综合类 | 16篇 |
一般理论 | 2篇 |
预防医学 | 768篇 |
眼科学 | 109篇 |
药学 | 601篇 |
中国医学 | 7篇 |
肿瘤学 | 749篇 |
出版年
2024年 | 7篇 |
2023年 | 94篇 |
2022年 | 137篇 |
2021年 | 304篇 |
2020年 | 169篇 |
2019年 | 217篇 |
2018年 | 312篇 |
2017年 | 182篇 |
2016年 | 240篇 |
2015年 | 284篇 |
2014年 | 398篇 |
2013年 | 498篇 |
2012年 | 762篇 |
2011年 | 753篇 |
2010年 | 385篇 |
2009年 | 409篇 |
2008年 | 609篇 |
2007年 | 638篇 |
2006年 | 601篇 |
2005年 | 655篇 |
2004年 | 519篇 |
2003年 | 521篇 |
2002年 | 416篇 |
2001年 | 43篇 |
2000年 | 35篇 |
1999年 | 62篇 |
1998年 | 89篇 |
1997年 | 64篇 |
1996年 | 41篇 |
1995年 | 39篇 |
1994年 | 29篇 |
1993年 | 24篇 |
1992年 | 13篇 |
1991年 | 12篇 |
1990年 | 7篇 |
1988年 | 6篇 |
1986年 | 5篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1982年 | 2篇 |
1980年 | 6篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1974年 | 2篇 |
1973年 | 5篇 |
1972年 | 2篇 |
1964年 | 2篇 |
1962年 | 3篇 |
1961年 | 2篇 |
1893年 | 1篇 |
排序方式: 共有9637条查询结果,搜索用时 31 毫秒
81.
Prognostic values of galectin-3 and the macrophage migration inhibitory factor (MIF) in human colorectal cancers. 总被引:7,自引:0,他引:7
Hugues Legendre Christine Decaestecker Nathalie Nagy Alain Hendlisz Max-Peter Schüring Isabelle Salmon Hans-Joachim Gabius Jean-Claude Pector Robert Kiss 《Modern pathology》2003,16(5):491-504
This study aims to investigate whether the immunohistochemical levels of expression of galectin-3 and the macrophage migration inhibitory factor (MIF) are associated with prognostic values in human colorectal tumors. This was performed on 99 specimens including 69 colorectal tumors (17 Dukes A, 19 Dukes B, 15 Dukes C and 18 metastatic tumors that we labeled as D), 10 hepatic metastases from colorectal cancers and 20 normal specimens (biopsies). The immunohistochemical levels of expression of MIF and galectin-3 were quantified on routine histological slides by means of computer-assisted microscopy. Separate analyses were performed on epithelial and connective tissue. The levels of expression of both MIF and galectin-3 were very significantly higher in epithelial tumor tissue when compared with normal epithelial specimens. A positive and significant correlation between MIF and galectin-3 expression was evidenced in connective tumor tissue, and in particular in the cases associated with short survival periods (less than 5 years). In the case of the Dukes A or B tumors, we established two new prognostic groups (labeled I and II) on the basis of the levels of galectin-3 expression measured in the tumor epithelium. In the case of the Dukes C or D tumors, we established two other prognostic groups (labeled III and IV) on the basis of the levels of MIF expression measured in the connective tissue. Kaplan-Meyer analyses confirmed the additional prognostic values (as compared with conventional clinical staging) given by this new classification (groups I to IV). They show that the Dukes A or B tumors characterized by low levels of galectin-3 expression in the tumor epithelium are associated with significantly better prognoses than those characterized by high levels. In addition, the Dukes C or D tumors characterized by high levels of MIF expression in the connective tumor tissue are associated with significantly better prognoses than those characterized by low levels. In conclusions, MIF and galectin-3 expression levels in colorectal tumors are related to their levels of biological aggressiveness. These markers could be used to identify patients at risk, for whom more aggressive adjuvant therapy seems to be indicated. 相似文献
82.
Arnaud Bernard Johanne Le Beyec-Le Bihan Loredana Radoi Muriel Coupaye Ouidad Sami Nathalie Casanova Cdric Le May Xavier Collet Pascaline Delaby Cindy Le Bourgot Philippe Besnard Sverine Ledoux 《Nutrients》2021,13(3)
The aim of this study was to explore the impact of bariatric surgery on fat and sweet taste perceptions and to determine the possible correlations with gut appetite-regulating peptides and subjective food sensations. Women suffering from severe obesity (BMI > 35 kg/m2) were studied 2 weeks before and 6 months after a vertical sleeve gastrectomy (VSG, n = 32) or a Roux-en-Y gastric bypass (RYGB, n = 12). Linoleic acid (LA) and sucrose perception thresholds were determined using the three-alternative forced-choice procedure, gut hormones were assayed before and after a test meal and subjective changes in oral food sensations were self-reported using a standardized questionnaire. Despite a global positive effect of both surgeries on the reported gustatory sensations, a change in the taste sensitivity was only found after RYGB for LA. However, the fat and sweet taste perceptions were not homogenous between patients who underwent the same surgery procedure, suggesting the existence of two subgroups: patients with and without taste improvement. These gustatory changes were not correlated to the surgery-mediated modifications of the main gut appetite-regulating hormones. Collectively these data highlight the complexity of relationships between bariatric surgery and taste sensitivity and suggest that VSG and RYGB might impact the fatty taste perception differently. 相似文献
83.
Pierre Di Pizio Noemie Celton Pierre Alain Menoud Stéphanie Belloc Martine Cohen Bacrie Naima Belhadri-Mansouri Nathalie Rives Rosalie Cabry Moncef Benkhalifa 《Andrologia》2021,53(1):e13822
Cell-free DNA (Cf-DNA) fragments may constitute an easy-to-measure molecular tool for guiding the choice of care provided to infertile couples who benefit assisted reproductive technology (ART) programmes. Data on Cf-DNA levels in the seminal plasma of men with sperm alterations are scarce. The objective of the present study was to quantify the presence of Cf-DNA in semen by using a quantitative real-time PCR. We compared men with abnormal sperm characteristics (n = 21) with normospermic controls (n = 21). The PCR assay evidenced significantly higher mean Cf-DNA levels in patients with sperm abnormalities than in controls (2.09 versus 1.18 µg/ml, respectively; p = .0003). The Cf-DNA levels were notably higher in men with azoospermia (3.65 µg/ml, versus 1.34 µg/ml in matched controls; p = .03) and men with teratozoospermia (1.80 µg/ml, versus 1.29 µg/ml in matched controls; p = .008). Our data report a significant association between elevated Cf-DNA levels and sperm abnormalities. These results may open up new diagnostic and prognostic perspectives in male infertility. 相似文献
84.
85.
Jinhui Ma Kerry Siminoski Peiyao Wang Jacob L Jaremko Khaldoun Koujok Mary Ann Matzinger Nazih Shenouda Brian Lentle Nathalie Alos Elizabeth A Cummings Josephine Ho Kristin Houghton Paivi M Miettunen Rosie Scuccimarri Frank Rauch Leanne M Ward the Canadian STOPP Consortium 《Journal of bone and mineral research》2021,36(7):1255-1268
Vertebral fractures are clinically important sequelae of a wide array of pediatric diseases. In this study, we examined the accuracy of case-finding strategies for detecting incident vertebral fractures (IVF) over 2 years in glucocorticoid-treated children (n = 343) with leukemia, rheumatic disorders, or nephrotic syndrome. Two clinical situations were addressed: the prevalent vertebral fracture (PVF) scenario (when baseline PVF status was known), which assessed the utility of PVF and low lumbar spine bone mineral density (LS BMD; Z-score <−1.4), and the non-PVF scenario (when PVF status was unknown), which evaluated low LS BMD and back pain. LS BMD was measured by dual-energy X-ray absorptiometry, vertebral fractures were quantified on spine radiographs using the modified Genant semiquantitative method, and back pain was assessed by patient report. Forty-four patients (12.8%) had IVF. In the PVF scenario, both low LS BMD and PVF were significant predictors of IVF. Using PVF to determine which patients should have radiographs, 11% would undergo radiography (95% confidence interval [CI] 8–15) with 46% of IVF (95% CI 30–61) detected. Sensitivity would be higher with a strategy of PVF or low LS BMD at baseline (73%; 95% CI 57–85) but would require radiographs in 37% of children (95% CI 32–42). In the non-PVF scenario, the strategy of low LS BMD and back pain produced the highest specificity of any non-PVF model at 87% (95% CI 83–91), the greatest overall accuracy at 82% (95% CI 78–86), and the lowest radiography rate at 17% (95% CI 14–22). Low LS BMD or back pain in the non-PVF scenario produced the highest sensitivity at 82% (95% CI 67–92), but required radiographs in 65% (95% CI 60–70). These results provide guidance for targeting spine radiography in children at risk for IVF. © 2021 American Society for Bone and Mineral Research (ASBMR). 相似文献
86.
Nathalie Chavarot Gillian Divard Anne Scemla Lucile Amrouche Olivier Aubert Marianne Leruez-Ville Marc O. Timsit Claire Tinel Julien Zuber Christophe Legendre Dany Anglicheau Rebecca Sberro-Soussan 《American journal of transplantation》2021,21(7):2448-2458
Belatacept may increase cytomegalovirus (CMV) disease risk after conversion from CNI-based therapy. We analyzed CMV disease characteristics after belatacept conversion. Propensity score matching was used to compare CMV disease incidence in belatacept- and CNI-treated kidney transplant recipients (KTRs). CMV disease characteristics and risk factors under belatacept were analyzed. In total, 223 KTRs (median age [IQR] 59.2 years [45.4–68.5]) were converted to belatacept (median of 11.5 months [2.5–37.0] post-transplantation); 40/223 (17.9%) developed CMV disease. Independent risk factors included increased age (p = .0164), D+/R− CMV serostatus (p = .0220), and low eGFR at conversion (p = .0355). Among 181 belatacept-treated patients matched to 181 controls, 32/181 (17.7%) experienced CMV disease (vs. 5/181 controls [2.8%]). CMV disease cumulative incidences were 6.33 and 0.91/100 person-years (p-y) in belatacept and control groups, respectively. CMV disease risk was particularly high in elderly patients (converted >70 years) and those with eGFR <30 ml/min; cumulative incidences were 18.4 and 5.2/100 p-y, respectively. CMV diseases under belatacept were atypical, with late-onset disease (24/40 patients [60%]), high CMV seropositivity (27/40, 67%), increased severe and tissue-invasive disease rates (gastrointestinal involvement in 32/40 [80%]) and life-threatening diseases (4/40 [10%]). These findings should stimulate further research to secure the use of belatacept as a valuable rescue therapy in KTRs. 相似文献
87.
Caron Kim Antoinette T. Nguyen Erin Berry-Bibee Yokabed Ermias Mary E. Gaffield Nathalie Kapp 《Contraception》2021,103(5):291-304
BackgroundImmediate contraceptive initiation, including start of a method before abortion completion, is a convenient option for women seeking abortion care.ObjectivesTo evaluate the effect of systemic hormonal contraception initiation on medical abortion effectiveness and the safety of hormonal contraceptive methods following abortion.Data sourcesPubMed, Popline, Cochrane Library, and Clinicaltrials.gov.Study eligibility criteriaStudies that assessed medical abortion effectiveness after systemic hormonal contraception initiation and the safety of hormonal contraception initiation after abortion.ParticipantsPregnant persons undergoing or who had recently undergone an abortion.InterventionsInitiation of systemic hormonal contraception post abortion or on the day of the first pill of the medical abortion.Study appraisal and synthesis methodsWe assessed study quality using the US Preventive Services Task Force evidence grading system. We created narrative summaries and calculated pooled relative risks when appropriate.ResultsWe identified 16 studies for inclusion, 7 randomized controlled trials, and 9 cohorts. Nine studies assessed medical abortion effectiveness with hormonal contraception initiation and generally found no decreased risk of abortion success or increased risk of additional treatment. One fair-quality study reported a small increase in ongoing pregnancy rate with immediate depot medroxyprogesterone (DMPA) compared with delayed DMPA initiation (3.6% vs 0.9%, risk difference 2.7%, 90% confidence interval 0.4–5.6). We identified no bleeding-related safety concerns following hormonal contraception initiation after medical or surgical abortion. Pooled results were too imprecise to draw firm conclusions.LimitationsIncluded studies were poor or fair quality and primarily in high-income or upper-middle-income settings.ConclusionsAbortion effectiveness did not differ between immediate vs delayed initiation of most systemic hormonal contraceptive methods after a first trimester medical abortion. However, immediate DMPA initiation did show increased ongoing pregnancy. Bleeding effects with hormonal contraception initiation postabortion appeared minimal.ImplicationsInitiating a hormonal contraceptive method after an abortion and as early as the same day as the first pill of the medical abortion is an option if contraception is desired. The slight increase in ongoing pregnancy with immediate DMPA initiation highlights the importance of information provision during contraceptive counseling. 相似文献
88.
89.
Mouillet Guillaume Falcoz Antoine Fritzsch Joëlle Almotlak Hamadi Jacoulet Pascale Pivot Xavier Villanueva Cristian Mansi Laura Kim Stefano Curtit Elsa Meneveau Nathalie Adotevi Olivier Jary Marine Eberst Guillaume Vienot Angelique Calcagno Fabien Pozet Astrid Djoumakh Oumelkheir Borg Christophe Westeel Virginie Anota Amélie Paget-Bailly Sophie 《Quality of life research》2021,30(11):3255-3266
Quality of Life Research - Routine Electronic Monitoring of Health-Related Quality of Life (HRQoL) (REMOQOL) in clinical care with real-time feedback to physicians could help to enhance... 相似文献
90.
ACE inhibition reduces activity of the plasminogen/plasmin and MMP systems in the brain of spontaneous hypertensive stroke-prone rats 总被引:2,自引:0,他引:2
Liebetrau M Burggraf D Wunderlich N Jäger G Linz W Hamann GF 《Neuroscience letters》2005,376(3):205-209
The spontaneously hypertensive stroke-prone rat (SHR-SP) is an experimental model of malignant hypertension which lead to secondary alterations of the extracellular matrix. Our aim was to determine ACE-inhibitor related changes of proteases involved in the reconstruction of the extracellular matrix in the brain. Twelve SHR-SP rats were randomized into two groups. Each group was treated with either an antihypertensive dose of ramipril or placebo for 6 months. Brain tissue plasminogen activator (t-PA) and urokinase (u-PA) were quantified by using casein-dependent plasminogen zymography, matrix metalloproteinase (MMP)-2 and MMP-9, by MMP-zymography, and tissue inhibitor of MMP (TIMP)-1 and -2, by reverse zymography. The amounts of u-PA, t-PA, and MMPs were significantly reduced in animals treated with ACE inhibitor. Plasminogen zymography showed a 39% reduction of u-PA in the basal ganglia (p < 0.0001); t-PA expression was reduced by 26% in the cortex and by 33% in the basal ganglia (p < 0.0001). MMP-2 expression was reduced by 15% in the cortex (p < 0.05) and by 10% in the basal ganglia (p < 0.05); MMP-9 expression significantly decreased by 37% in the cortex and by 25% in the basal ganglia (p < 0.0001 each). No differences were observed in the amount of TIMP-1 or TIMP-2. These findings provide new insights into the biochemical mechanisms underlying extracellular matrix proliferation and its modulation by ACE inhibitors. Therapeutic alterations that influence the proteolytic systems might prove important in the prevention of extracellular matrix accumulation and secondary microvascular vessel wall changes. 相似文献