全文获取类型
收费全文 | 117008篇 |
免费 | 5432篇 |
国内免费 | 695篇 |
专业分类
耳鼻咽喉 | 1847篇 |
儿科学 | 6568篇 |
妇产科学 | 2612篇 |
基础医学 | 9988篇 |
口腔科学 | 4262篇 |
临床医学 | 8306篇 |
内科学 | 26195篇 |
皮肤病学 | 3506篇 |
神经病学 | 7692篇 |
特种医学 | 5341篇 |
外科学 | 24480篇 |
综合类 | 2824篇 |
现状与发展 | 2篇 |
一般理论 | 1篇 |
预防医学 | 6432篇 |
眼科学 | 2326篇 |
药学 | 6342篇 |
4篇 | |
中国医学 | 905篇 |
肿瘤学 | 3502篇 |
出版年
2023年 | 3528篇 |
2022年 | 4178篇 |
2021年 | 5883篇 |
2020年 | 4544篇 |
2019年 | 11703篇 |
2018年 | 8865篇 |
2017年 | 4428篇 |
2016年 | 1506篇 |
2015年 | 2105篇 |
2014年 | 2979篇 |
2013年 | 1842篇 |
2012年 | 1164篇 |
2011年 | 4549篇 |
2010年 | 1419篇 |
2009年 | 1889篇 |
2008年 | 1932篇 |
2007年 | 1389篇 |
2006年 | 1206篇 |
2005年 | 1683篇 |
2004年 | 1714篇 |
2003年 | 1234篇 |
2002年 | 1769篇 |
2001年 | 2070篇 |
2000年 | 3142篇 |
1999年 | 3462篇 |
1998年 | 3258篇 |
1997年 | 2200篇 |
1996年 | 1494篇 |
1995年 | 1048篇 |
1994年 | 1104篇 |
1993年 | 778篇 |
1992年 | 941篇 |
1991年 | 673篇 |
1990年 | 716篇 |
1989年 | 492篇 |
1988年 | 539篇 |
1987年 | 341篇 |
1985年 | 2792篇 |
1984年 | 4089篇 |
1983年 | 2910篇 |
1982年 | 2859篇 |
1981年 | 2686篇 |
1980年 | 2381篇 |
1979年 | 2201篇 |
1978年 | 1810篇 |
1977年 | 1578篇 |
1976年 | 1697篇 |
1975年 | 1441篇 |
1974年 | 1279篇 |
1973年 | 1202篇 |
排序方式: 共有10000条查询结果,搜索用时 93 毫秒
11.
《Obstetrics, Gynaecology and Reproductive Medicine》2022,32(8):179-187
Continuous utero-placental circulation, and patent umbilical blood vessels ensure an uninterrupted transfer of oxygen and nutrients to the fetus as well as clearance of metabolic waste products. The onset of labour characterized by progressive and strong uterine contractions poses a threat to fetal oxygenation as a result of collapsing the spiral arterioles traversing the myometrium to supply the placental bed, and repetitive compression of the blood vessels within the umbilical cord. Human fetuses are equipped with compensatory mechanisms to cope with transient interruptions of blood supply during labour. The ability to compensate may be blunted in cases of poor fetal reserves, increased metabolic demand (macrosomia or maternal fever), and due to non-hypoxic pathways (e.g. chorioamniontis or fetal hypovolumia-hypotension syndrome). Intrapartum fetal surveillance involves prompt recognition of the features that signal the onset of fetal decompensation on the cardiotocograph (CTG) to ensure a timely intervention to avoid hypoxic-ischaemic encephalopathy (HIE) or perinatal deaths. This article summarises a ‘physiological approach’ to the interpretation of the CTG which, in places, conflicts with other current UK guidance. 相似文献
12.
13.
14.
15.
《Journal of pediatric surgery》2023,58(9):1843-1848
BackgroundCommon salt is a safe, effective and cheap home-made remedy for umbilical granuloma. The aim of this scoping review is to identify and summarize the available evidence and examine the research conducted on salt treatment for umbilical granuloma.MethodsA literature search was performed in the second week of September, 2022 using Google scholar, PubMed, MEDLINE and EMBASE databases using the keywords ‘umbilical granuloma’ and ‘salt treatment’ to identify all English articles pertaining to salt treatment for umbilical granuloma. Tables were made to summarize the methodological characteristics, results and the dosage regimens of salt used by different authors. The Cochrane Collaboration's tool was used for assessing risk of bias in RCTs. The indexing statuses of the journals publishing these studies were also noted. The overall efficacy with the use of common salt was calculated by adding the success rates mentioned in each study.ResultsTwenty-four articles (2 systematic reviews, 6 Randomized Controlled Trials, 11 prospective cohort studies, 1 case control study, 3 retrospective case series and 1 case report) were included. An overall 93.91% success rate (1033/1100) was seen with common salt application, without any reports of complications/recurrences.ConclusionTopical application of common salt for umbilical granulomas is simple, effective and inexpensive. This scoping review provides a broader outlook at the existing level of evidence and may help in planning interventional comparative studies, so that recommendations can be formulated. It also highlights a lack of properly designed randomized controlled trials on this topic.Level of EvidenceI. 相似文献
16.
《The Journal of thoracic and cardiovascular surgery》2023,165(2):591-604.e3
ObjectivesGuidelines suggest aortic valve replacement (AVR) for low-risk asymptomatic patients. Indications for transcatheter AVR now include low-risk patients, making it imperative to understand state-of-the-art surgical AVR (SAVR) in this population. Therefore, we compared SAVR outcomes in low-risk patients with those expected from Society of Thoracic Surgeons (STS) models and assessed their intermediate-term survival.MethodsFrom January 2005 to January 2017, 3493 isolated SAVRs were performed in 3474 patients with STS predicted risk of mortality <4%. Observed operative mortality and composite major morbidity or mortality were compared with STS-expected outcomes according to calendar year of surgery. Logistic regression analysis was used to identify risk factors for these outcomes. Patients were followed for time-related mortality.ResultsWith 15 observed operative deaths (0.43%) compared with 55 expected (1.6%), the observed:expected ratio was 0.27 for mortality (95% confidence interval [CI], 0.14-0.42), stroke 0.65 (95% CI, 0.41-0.89), and reoperation 0.50 (95% CI, 0.42-0.60). Major morbidity or mortality steadily declined, with probabilities of 8.6%, 6.7%, and 5.2% in 2006, 2011, and 2016, respectively, while STS-expected risk remained at approximately 12%. Mitral valve regurgitation, ventricular hypertrophy, pulmonary, renal, and hepatic failure, coronary artery disease, and earlier surgery date were residual risk factors. Survival was 98%, 91%, and 82% at 1, 5, and 9 years, respectively, superior to that predicted for the US age-race-sex–matched population.ConclusionsSTS risk models overestimate contemporary SAVR risk at a high-volume center, supporting efforts to create a more agile quality assessment program. SAVR in low-risk patients provides durable survival benefit, supporting early surgery and providing a benchmark for transcatheter AVR. 相似文献
17.
《Journal of pediatric surgery》2023,58(9):1694-1698
BackgroundThe Coronavirus Disease 2019 pandemic provided a natural experiment to study the effect of social distancing on the risk of developing Hirschsprung's Associated Enterocolitis (HAEC).MethodsUsing the Pediatric Health Information System (PHIS), a retrospective cohort study of children (<18 years) with Hirschsprung's Disease (HSCR) across 47 United States children's hospitals was performed. The primary outcome was HAEC admissions per 10,000 patient-days. The exposure (COVID-19) was defined as April 2020–December 2021. The unexposed (historical control) period was April 2018–December 2019. Secondary outcomes included sepsis, bowel perforation, intensive care unit (ICU) admission, mortality, and length of stay.ResultsOverall, we included 5707 patients with HSCR during the study period. There were 984 and 834 HAEC admissions during the pre-pandemic and pandemic periods, respectively (2.6 vs. 1.9 HAEC admissions per 10,000 patient-days, incident rate ratio [95% confidence interval]: 0.74 [0.67, 0.81], p < 0.001). Compared to pre-pandemic, those with HAEC during the pandemic were younger (median [IQR]: 566 [162, 1430] days pandemic vs. 746 [259, 1609] days pre-pandemic, p < 0.001) and more likely to live in the lowest quartile of median household income zip codes (24% pandemic vs. 19% pre-pandemic, p = 0.02). There were no significant differences in rates of sepsis (6.1% pandemic vs. 6.1% pre-pandemic, p > 0.9), bowel perforation (1.3% pandemic vs. 1.2% pre-pandemic, p = 0.8), ICU admissions (9.6% pandemic vs. 12% pre-pandemic, p = 0.2), mortality (0.5% pandemic vs. 0.6% pre-pandemic, p = 0.8), or length of stay (median [interquartile range]: 4 [(Pastor et al., 2009; Gosain and Brinkman, 2015) 2,112,11 days pandemic vs. 5 [(Pastor et al., 2009; Tang et al., 2020) 2,102,10 days pre-pandemic, p = 0.4).ConclusionsThe COVID-19 pandemic was associated with significantly decreased incidence of HAEC admissions across US children's hospitals. Possible etiologies such as social distancing should be explored.Level of evidenceII. 相似文献
18.
《The Annals of thoracic surgery》2023,115(1):88-95
BackgroundRecent guidelines for the treatment of moderate or severe ischemic mitral regurgitation (IMR) in patients undergoing coronary artery bypass grafting (CABG) have changed. This study assessed the real-world impact of changing guidelines on the management of IMR during CABG over time. We hypothesized that the utilization of mitral valve repair for IMR would decrease over time, whereas mitral valve replacement for severe IMR would increase.MethodsPatients undergoing CABG in a statewide collaborative database (2011-2020) were stratified by severity of IMR. Trends in mitral valve repair or replacement were evaluated. To account for differences of the patients, propensity score–matched analyses were used to compare patients with and without mitral intervention.ResultsA total of 11,676 patients met inclusion criteria, including 1355 (11.6%) with moderate IMR and 390 (3.3%) with severe IMR. The proportion of patients undergoing mitral intervention for moderate IMR decreased over time (2011, 17.7%; 2020, 7.5%; Ptrend = .001), whereas mitral replacement for severe IMR remained stable (2011, 11.1%; 2020, 13.3%; Ptrend = .14). Major morbidity was higher for patients with moderate IMR who underwent mitral intervention (29.1% vs 19.9%; P = .005). In a propensity analysis of 249 well-matched pairs, there was no difference in major morbidity (29.3% with mitral intervention vs 23.7% without; P = .16) or operative mortality (1.2% vs 2.4%; P = .5).ConclusionsConsistent with recent guideline updates, patients with moderate IMR were less likely to undergo mitral repair. However, the rate of replacement for severe IMR did not change. Mitral intervention during CABG did not increase operative mortality or morbidity. 相似文献
19.
《Research in social & administrative pharmacy》2022,18(3):2367-2391
ObjectivesSeveral implementation strategies can reduce potentially inappropriate medication (PIM) prescribing. Although use of PIMs has declined in recent years, it remains prevalent. Various strategies exist to improve the appropriateness of medication use. However, little is known about the processes of these different implementation strategies. This scoping review aims to investigate how the process evaluation of implementation strategies for reducing PIM prescribing in the older population has been studied.MethodsWe searched for process evaluations of implementation strategies for reducing PIM prescribing in PUBMED, SCOPUS and Web of Science published between January 2000 and November 2019 in English. We applied the following inclusion criteria: patients aged ≥65 years, validated PIM criteria, and implementation process evaluated. The review focuses on decision support for health care professionals. We described the findings of the process evaluations, and compared the authors’ concepts of process evaluation of the included publications to those of Proctor et al.( 2010).ResultOf 9131 publications screened, 29 met our inclusion criteria. Different process evaluation conceptualizations were identified. Most process evaluations took place in the initial stages of the process (acceptability, adoption, appropriateness, and feasibility) and sustainability and implementation costs were seldom evaluated. None of the included publications evaluated fidelity.Multifaceted interventions were the most studied implementation strategies. Medication review was more common in acceptability evaluations, multidisciplinary interventions in adoption evaluations, and computerized systems and educational interventions in feasibility evaluations. Process evaluations were studied from the health care professionals’ viewpoint in most of the included publications, but the management viewpoint was missing.DiscussionThe conceptualization of process evaluation in the field of PIM prescribing is indeterminate. There is also a current gap in the knowledge of sustainability and implementation costs. Clarifying the conceptualization of implementation process evaluation is essential in order to effectively translate research knowledge into practice. 相似文献
20.
Kyung-Suk Suh Suk Kyun Hong Sola Lee Su young Hong Sanggyun Suh Eui Soo Han Seong-Mi Yang YoungRok Choi Nam-Joon Yi Kwang-Woong Lee 《American journal of transplantation》2022,22(1):260-265
Minimally invasive approaches are increasingly being applied in surgeries and have recently been used in living donor hepatectomy. We have developed a safe and reproducible method for minimally invasive living donor liver transplantation, which consists of pure laparoscopic explant hepatectomy and pure laparoscopic implantation of the graft, which was inserted through a suprapubic incision. Pure laparoscopic explant hepatectomy without liver fragmentation was performed in a 60-year-old man with alcoholic liver cirrhosis and hepatocellular carcinoma. The explanted liver was retrieved through a suprapubic incision. A modified right liver graft, procured from his 24-year-old son using the pure laparoscopic method, was inserted through a suprapubic incision, and implantation was performed intracorporeally throughout the procedure. The time required to remove the liver was 369 min, and the total operative time was 960 min. No complications occurred during or after the surgery. The patient recovered well, and his hospital stay was of 11 days. Pure laparoscopic living donor liver transplantation from explant hepatectomy to implantation was performed successfully. It is a feasible procedure when performed by a highly experienced surgeon and transplantation team. Further studies with larger sample sizes are needed to confirm its safety and feasibility.