全文获取类型
收费全文 | 191511篇 |
免费 | 1750篇 |
国内免费 | 158篇 |
专业分类
耳鼻咽喉 | 1242篇 |
儿科学 | 6960篇 |
妇产科学 | 3527篇 |
基础医学 | 18431篇 |
口腔科学 | 1930篇 |
临床医学 | 13666篇 |
内科学 | 35583篇 |
皮肤病学 | 903篇 |
神经病学 | 17923篇 |
特种医学 | 9519篇 |
外科学 | 31064篇 |
综合类 | 2355篇 |
一般理论 | 1篇 |
预防医学 | 18632篇 |
眼科学 | 2945篇 |
药学 | 10276篇 |
中国医学 | 654篇 |
肿瘤学 | 17808篇 |
出版年
2023年 | 119篇 |
2022年 | 253篇 |
2021年 | 499篇 |
2020年 | 272篇 |
2019年 | 393篇 |
2018年 | 22303篇 |
2017年 | 17640篇 |
2016年 | 19810篇 |
2015年 | 1336篇 |
2014年 | 1462篇 |
2013年 | 1596篇 |
2012年 | 8138篇 |
2011年 | 22146篇 |
2010年 | 19497篇 |
2009年 | 12195篇 |
2008年 | 20638篇 |
2007年 | 22829篇 |
2006年 | 1689篇 |
2005年 | 3291篇 |
2004年 | 4380篇 |
2003年 | 5201篇 |
2002年 | 3274篇 |
2001年 | 354篇 |
2000年 | 477篇 |
1999年 | 269篇 |
1998年 | 376篇 |
1997年 | 337篇 |
1996年 | 248篇 |
1995年 | 204篇 |
1994年 | 202篇 |
1993年 | 163篇 |
1992年 | 128篇 |
1991年 | 149篇 |
1990年 | 184篇 |
1989年 | 123篇 |
1988年 | 91篇 |
1987年 | 70篇 |
1986年 | 60篇 |
1985年 | 65篇 |
1984年 | 61篇 |
1983年 | 56篇 |
1982年 | 65篇 |
1981年 | 43篇 |
1980年 | 75篇 |
1979年 | 27篇 |
1974年 | 34篇 |
1938年 | 61篇 |
1934年 | 31篇 |
1932年 | 57篇 |
1930年 | 51篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Lisa Armistead Nada Goodrum Marya Schulte William Marelich Rebecca LeCroix Debra A. Murphy 《AIDS and behavior》2018,22(12):3807-3814
Nondisclosure of maternal HIV status to young children can negatively impact child functioning; however, many mothers do not disclose due to lack of self-efficacy for the disclosure process. This study examines demographic variations in disclosure self-efficacy, regardless of intention to disclose, and assesses the relationship between self-efficacy and child adjustment via the parent–child relationship among a sample of HIV+ mothers and their healthy children (N = 181 pairs). Mothers completed demographic and self-efficacy measures; children completed measures assessing the parent–child relationship and child adjustment (i.e., worry, self-concept, depression). Across demographics, few mothers reported confidence in disclosure. Results from covariance structural modeling showed mothers endorsing higher self-efficacy had children who reported better relationship quality, and, in turn, reported fewer adjustment difficulties; higher levels of disclosure self-efficacy also directly predicted fewer adjustment problems. Findings offer support for interventions aimed at providing mothers with skills to enhance confidence for disclosing their HIV status. 相似文献
992.
Kurt Kroenke Tasneem L. Talib Timothy E. Stump Jacob Kean David A. Haggstrom Paige DeChant Kittie R. Lake Madison Stout Patrick O. Monahan 《Journal of general internal medicine》2018,33(8):1245-1252
Background
Symptoms account for more than 400 million clinic visits annually in the USA. The SPADE symptoms (sleep, pain, anxiety, depression, and low energy/fatigue) are particularly prevalent and undertreated.Objective
To assess the effectiveness of providing PROMIS (Patient-Reported Outcome Measure Information System) symptom scores to clinicians on symptom outcomes.Design
Randomized clinical trial conducted from March 2015 through May 2016 in general internal medicine and family practice clinics in an academic healthcare system.Participants
Primary care patients who screened positive for at least one SPADE symptom.Interventions
After completing the PROMIS symptom measures electronically immediately prior to their visit, the 300 study participants were randomized to a feedback group in which their clinician received a visual display of symptom scores or a control group in which scores were not provided to clinicians.Main Measures
The primary outcome was the 3-month change in composite SPADE score. Secondary outcomes were individual symptom scores, symptom documentation in the clinic note, symptom-specific clinician actions, and patient satisfaction.Key Results
Most patients (84%) had multiple clinically significant (T-score?≥?55) SPADE symptoms. Both groups demonstrated moderate symptom improvement with a non-significant trend favoring the feedback compared to control group (between-group difference in composite T-score improvement, 1.1; P?=?0.17). Symptoms present at baseline resolved at 3-month follow-up only one third of the time, and patients frequently still desired treatment. Except for pain, clinically significant symptoms were documented less than half the time. Neither symptom documentation, symptom-specific clinician actions, nor patient satisfaction differed between treatment arms. Predictors of greater symptom improvement included female sex, black race, fewer medical conditions, and receiving care in a family medicine clinic.Conclusions
Simple feedback of symptom scores to primary care clinicians in the absence of additional systems support or incentives is not superior to usual care in improving symptom outcomes.Trial Registration
clinicaltrials.gov identifier: NCT02383862.993.
Manufacturing Better Outcomes in Cardiovascular Intervention: 3D Printing in Clinical Practice Today
Purpose of review
Describe and evaluate the integration of 3D printing-related innovations into current cardiovascular treatment paradigms and examine the state of regulatory and reimbursement hurdles ahead.Recent findings
Mounting years of clinical experience have established the utility of printed models of patient anatomy in numerous treatment and teaching scenarios, most notably as pre- and intra-procedural planning tools guiding decision-making for congenital heart disease and catheter-based interventions. In part due to a continued lack of reimbursement and under-defined (and slow to evolve) regulatory status, these use cases remain largely investigational even as they grow increasingly routine. Patients, physicians, and/or imaging centers therefore remain burdened by the associated cost to create such models, and the perceptual and decision-making enhancements, while demonstrable and significant, still may not clearly or independently justify a potentially high cost.Simulation and implantable device applications may represent a deeper well of unrealized value in cardiovascular intervention; however, further development of these applications relies on—and is throttled by—progress in material science and tissue-engineering research. The relevance of simulation applications in recent years is also now in competition with digital analogs including augmented and virtual reality. Innovative incorporation of alternative manufacturing processes such as porous scaffold infusion, injection molding, and vascular mesh forming can provide immediate access to more realistic tissue-mimicking materials and custom implantable devices, while comparable and directly printable materials continue to be developed. Tissue-engineering applications remain years if not decades away from a more substantive role in translatable clinical research. Regulatory challenges associated with in-house manufacture of implantable investigational devices are complex and subject to change, and the success of some in navigating these hurdles in non-cardiovascular applications is instructive and encouraging.Summary
Complex geometries characterizing cardiovascular anatomy are an ideal use case for translating the perceptual advantages of printed models of patient anatomy into better decision-making, especially so in the setting of congenital or post-surgical anatomy. Procedural planning applications take further advantage of the demonstrably robust dimensional reproduction of patient anatomy, with notably rapid integration into surgical and catheter-based intervention workflows. Despite a continued lack of codification in the healthcare system, 2018 could be a milestone year for 3D printing services, pending a successful application for a CPT Category III designation.994.
Marjolijn Duijvestein Robert Battat Niels Vande Casteele Geert R. D’Haens William J. Sandborn Reena Khanna Vipul Jairath Brian G. Feagan 《Current Treatment Options in Gastroenterology》2018,16(1):129-146
Purpose of review
This article reviews current treatment options and strategies and provides an update on the status of drug development programs of new therapeutic agents for inflammatory bowel diseases (IBD).Recent findings
In the past two decades, tumor necrosis factor antagonist therapy has given clinicians better treatment options. However, not all patients respond to induction therapy with these agents, and of those initially responding, up to 40% ultimately lose response due to suboptimal drug exposure (e.g., caused by immunogenicity), side effects, or other poorly characterized mechanisms. Recently, additional therapies, such as vedolizumab, an integrin blocker that prevents T cell trafficking to the gut, and ustekinumab, an antibody blocking the common p40 subunit of interleukin (IL)-12 and 23, were introduced to the market. In addition, other agents including novel anti-trafficking therapies (e.g., anti-β7 and sphingosine-1-phosphate receptor modulators), antibodies against p19 (unique to IL-23), and small molecules including Janus kinase inhibitors are under investigation in phase II and III trials.Furthermore, the management of IBD has evolved from targeting control of symptoms to suppression of mucosal inflammation. This shift in thinking has been accompanied by the early use of highly effective therapy in poor prognosis patients, accelerated treatment escalation and utilization of a treat to target paradigm approach, and adoption of therapeutic drug monitoring.Summary
The treatment landscape for IBD is rapidly evolving with the recent approval of novel biologics as well as several other agents in late phase of clinical development. Moreover, we have started to use agents more intelligently with a focus on risk stratification and early use of highly effective therapy in high-risk patients, treat to target using patient-reported outcomes (PROs), biomarkers, endoscopy, and therapeutic drug monitoring.995.
Ujjwal Sonika Shekhar Jadaun Gyan Ranjan Gyanranjan Rout Deepak Gunjan Saurabh Kedia Baibaswata Nayak Shalimar 《Indian journal of gastroenterology》2018,37(1):50-57
Background and Aims
Various prognostic scores are available for predicting outcome in acute-on-chronic liver failure (ACLF). We compared the available prognostic models as predictors of outcome in alcohol-related ACLF patients.Methods
All consecutive patients with alcohol-related ACLF were included. At admission, prognostic indices-acute physiology and chronic health evaluation score (APACHE II), model for end-stage liver disease (MELD), MELD-Na, Maddrey’s discriminant function (DF), age-bilirubin-INR-creatinine (ABIC), and Chronic Liver Failure Consortium (CLIF-C) ACLF score (CLIF-C ACLF) score were calculated. Receiver operator characteristic (ROC) curves were plotted for all prognostic scores with in-hospital, 90-day, and 1-year mortality as outcome.Results
Of the 171 patients, 170 were males, and grade 1 ACLF in 20 (11.7%), grade 2 in 52 (30.4%), and grade 3 in 99 (57.9%) patients. One hundred and nineteen (69.6%) died in-hospital. The median (IQR) Maddrey’s score, MELD, MELD-Na, ABIC, APACHE II, and CLIF-C ACLF were 87.8 (66.5–123.0), 33.1 (27.6–40.0), 34.4 (29.5–40.0), 8.5 (7.3–9.6), 15 (12–21), and 51.1 (44.1–56.4), respectively. On multivariate Cox regression analysis, independent predictors of in-hospital outcome were presence of hepatic encephalopathy (early HR, 2.078; 95%CI, 1.173–3.682, p?=?0.012 and advanced, HR, 2.330; 95% CI, 1.270–4.276, p?=?0.006), elevated serum creatinine (HR, 1.140; 95% CI, 1.023–1.270, p?=?0.018), and infection at admission (HR, 1.874; 95% CI, 1.160–23.029, p?=?0.010). On comparison of ROC curves, APACHE II and CLIF-C ACLF AUROC were significantly higher than MELD, MELD-Na, DF, and ABIC (p?<?0.05) for predicting in-hospital, 90-day, and 1-year mortality. The AUROC was highest for APACHE II followed by CLIF-C ACLF (Hanley and McNeil, p?=?0.660).Conclusions
Alcohol-related ACLF has high in-hospital mortality. Among the available prognostic scores, CLIF-C ACLF and APACHE II perform best.996.
Dimitrios Pantelis Robert Hüneburg Ronja Adam Stefanie Holzapfel Heidrun Gevensleben Jacob Nattermann Christian P. Strassburg Stefan Aretz Jörg C. Kalff 《International journal of colorectal disease》2016,31(12):1825-1833
Purpose
Germline mutations in several genes confer a relevant lifetime risk of gastric cancer. In this context, an increasing involvement of a surgeon can be seen, mainly with the question of performing a prophylactic operation.Methods
Patients with hereditary tumor syndromes predisposing for gastric cancer who received care leading to prophylactic total gastrectomy in our Center for Hereditary Tumor Syndromes were analyzed. For each patient, the multidisciplinary decision-making process, the perioperative course, and the histopathologic findings were assessed. Short-term morbidity was evaluated based on the medical reports.Results
The analysis includes nine patients (six female, three male) with a median age of 41.6 (range 23–60) years. Indication for prophylactic total gastrectomy was based on family history and genetic analysis (eight patients with a germline mutation of the CDH1 gene and one patient with a SMAD4 mutation). Removal of the entire gastric mucosa was documented intraoperatively by fresh frozen section examination. Extended (DII) lymphadenectomy was performed in four patients. Histopathologic examination of gastrectomy specimens revealed six patients (6/9, 67 %) with multifocal signet ring cell carcinomas. In our series, prophylactic total gastrectomy was a safe procedure without mortality and low morbidity.Conclusions
Patients with hereditary syndromes predisposing for gastric cancer should be evaluated for this curative procedure in a specialized center. Further research is necessary, and the implementation of nationwide registers including patients with prophylactic gastrointestinal operations due to hereditary tumor syndrome is advisable.997.
Natasa Stanisavljevic L. Stojanovich D. Marisavljevic A. Djokovic V. Dopsaj J. Kotur-Stevuljevic J. Martinovic L. Memon S. Radovanovic B. Todic D. Lisulov 《Clinical rheumatology》2016,35(10):2485-2493
The aim of this study was to evaluate oxidative stress markers and it relations to endothelial damage as risk factor for thrombosis in patients with primary (PAPS) and secondary (SAPS) antiphospholipid syndrome (APS) in correlation to traditional risk factors. Flow-mediated (FMD) and nitroglycerine (NMD)-induced dilation of the brachial artery were studied in 140 APS patients (90 PAPS, 50 SAPS) and 40 controls matched by age, sex, and conventional risk factors for atherosclerosis. Markers of oxidative stress, lipid hydroperoxydes (LOOH), advanced oxidation protein products (AOPP), total sulfhydryl groups (tSHG), and paraoxonase 1 activity (PON1) were determined by spectrophotometric method. Oxidative stress dominates in APS patients. LOOH and AOPP correlate to lipid fractions (p < 0.05), unlike PON1, tSHG that correlated to antiphospholipid antibody positivity (p < 0.05). FMD was lower in APS patients comparing to controls (p < 0.001). Cholesterol is independent variable for FMD impairment in control group (p = 0.011); LOOH in PAPS (p = 0.004); LOOH, aCL, and triglycerides in SAPS patients (p = 0.009, p = 0.049, and p = 0.012, respectively). Combined predictive of aCL and LOOH is better for FMD impairment than LOOH alone in both PAPS and SAPS patients (AUC 0.727, p = 0.001, 95 % CI 0.616–0.837 and AUC 0.824, p?0.001, 95 % CI 0.690–0.957, respectively). Lipid peroxidation is independent predictor for endothelial dysfunction in APS patients. We demonstrated synergistic effect of aCL and LOOH as risk for endothelial impairment in both PAPS and SAPS patients. 相似文献
998.
Christian Staufner Martin Lindner Carlo Dionisi-Vici Peter Freisinger Dries Dobbelaere Claire Douillard Nawal Makhseed Beate K. Straub Kimia Kahrizi Diana Ballhausen Giancarlo la Marca Stefan Kölker Dorothea Haas Georg F. Hoffmann Sarah C. Grünert Henk J. Blom 《Journal of inherited metabolic disease》2016,39(2):273-283
Background
Adenosine kinase deficiency is a recently described defect affecting methionine metabolism with a severe clinical phenotype comprising mainly neurological and hepatic impairment and dysmorphism.Methods
Clinical data of 11 additional patients from eight families with adenosine kinase deficiency were gathered through a retrospective questionnaire. Two liver biopsies of one patient were systematically evaluated.Results
The main clinical symptoms are mild to severe liver dysfunction with neonatal onset, muscular hypotonia, global developmental retardation and dysmorphism (especially frontal bossing). Hepatic involvement is not a constant finding. Most patients have epilepsy and recurrent hypoglycemia due to hyperinsulinism. Major biochemical findings are intermittent hypermethioninemia, increased S-adenosylmethionine and S-adenosylhomocysteine in plasma and increased adenosine in urine. S-adenosylmethionine and S-adenosylhomocysteine are the most reliable biochemical markers. The major histological finding was pronounced microvesicular hepatic steatosis. Therapeutic trials with a methionine restricted diet indicate a potential beneficial effect on biochemical and clinical parameters in four patients and hyperinsulinism was responsive to diazoxide in two patients.Conclusion
Adenosine kinase deficiency is a severe inborn error at the cross-road of methionine and adenosine metabolism that mainly causes dysmorphism, brain and liver symptoms, but also recurrent hypoglycemia. The clinical phenotype varies from an exclusively neurological to a multi-organ manifestation. Methionine-restricted diet should be considered as a therapeutic option.999.
Gulley D Teal E Suvannasankha A Chalasani N Liangpunsakul S 《Digestive diseases and sciences》2008,53(11):3012-3017
Background and Aims It is a commonly held notion that patients with cirrhosis do not suffer from deep vein thrombosis (DVT) or pulmonary embolism
(PE) because they are naturally anticoagulated. However, to date, no studies have been carried out that objectively address
this issue. We conducted a study to examine the relationship between cirrhosis and DVT/PE events. Methods A case–control study of patients seen at a tertiary care hospital was performed. Cases were hospitalized patients with biopsy
and/or imaging plus clinical evidence of cirrhosis. Well-matched patients with no known evidence of cirrhosis served as controls.
The DVT/PE events were identified by the international classification of disease-9 (ICD-9) codes and confirmed with radiographic/nuclear
imaging. The Charlson Index was calculated to determine the comorbidity. The incidence of DVT/PE in cirrhotic patients was
also compared to patients with chronic kidney disease (CKD), congestive heart failure (CHF), and solid organ cancers. Results This study consisted of 963 cirrhotics and 12,405 controls. Both the incidence of DVT/PE (1.8 vs. 0.9%, P = 0.007) and Charlson Index scores (3.2 ± 1.8 vs. 0.9 ± 1.5, P < 0.001) were higher in cirrhotics than in the controls. However, in the multivariate analysis, the presence of cirrhosis
was not associated with DVT/PE [odds ratio (OR) 0.87, P = 0.06]. Partial thromboplastin time (PTT; OR 0.88, P = 0.04) and serum albumin (OR 0.47, P = 0.03) were the independent predictors of DVT/PE. The incidence of DVT/PE in cirrhotics (1.8%) was lower than that in patients
with other medical illnesses: 7.1% in CKD, 7.8% in CHF, and 6.1% in cancers. Conclusion Patients with cirrhosis do not have a lower risk of DVT/PE than non-cirrhotic controls without other significant co-morbidities,
such as CHF, CKD, and solid organ cancers. Partial thromboplastin time and serum albumin were found to be independently predictive
of DVT/PE in cirrhotic patients. 相似文献
1000.
D'Aloia A Faggiano P Fiorina C Vizzardi E Bontempi L Grazioli L Dei Cas L 《International journal of cardiology》2003,90(2-3):327-329
Congenital anomalies of the inferior vena cava such as absence or atresia are uncommon vascular defects and result from aberrant development during embryogenesis. We report a case of a young female patient affected by proximal deep venous thrombosis (DVT) complicated by liver and pulmonary embolism; subsequent extensive evaluation revealed the congenital absence of infrarenal inferior vena cava, with emboli probably occurring through collateral veins. Accordingly, in young patients with idiopathic DVT of the lower extremities and pelvic veins, the presence of inferior vena cava abnormalities should always be considered and investigated, together with classic coagulation factors, as a factor predisposing to thromboembolic complications. 相似文献