全文获取类型
收费全文 | 31917篇 |
免费 | 2851篇 |
国内免费 | 659篇 |
专业分类
耳鼻咽喉 | 244篇 |
儿科学 | 1278篇 |
妇产科学 | 779篇 |
基础医学 | 1744篇 |
口腔科学 | 928篇 |
临床医学 | 3574篇 |
内科学 | 6388篇 |
皮肤病学 | 417篇 |
神经病学 | 1323篇 |
特种医学 | 789篇 |
外国民族医学 | 1篇 |
外科学 | 2899篇 |
综合类 | 4276篇 |
现状与发展 | 1篇 |
预防医学 | 4563篇 |
眼科学 | 1525篇 |
药学 | 2275篇 |
36篇 | |
中国医学 | 1150篇 |
肿瘤学 | 1237篇 |
出版年
2024年 | 62篇 |
2023年 | 892篇 |
2022年 | 1351篇 |
2021年 | 2140篇 |
2020年 | 1952篇 |
2019年 | 1769篇 |
2018年 | 1753篇 |
2017年 | 1306篇 |
2016年 | 1217篇 |
2015年 | 1161篇 |
2014年 | 2408篇 |
2013年 | 2284篇 |
2012年 | 1913篇 |
2011年 | 2054篇 |
2010年 | 1661篇 |
2009年 | 1571篇 |
2008年 | 1460篇 |
2007年 | 1504篇 |
2006年 | 1076篇 |
2005年 | 994篇 |
2004年 | 768篇 |
2003年 | 629篇 |
2002年 | 454篇 |
2001年 | 416篇 |
2000年 | 297篇 |
1999年 | 280篇 |
1998年 | 207篇 |
1997年 | 191篇 |
1996年 | 167篇 |
1995年 | 173篇 |
1994年 | 169篇 |
1993年 | 135篇 |
1992年 | 137篇 |
1991年 | 120篇 |
1990年 | 96篇 |
1989年 | 82篇 |
1988年 | 60篇 |
1987年 | 68篇 |
1986年 | 50篇 |
1985年 | 73篇 |
1984年 | 60篇 |
1983年 | 57篇 |
1982年 | 43篇 |
1981年 | 48篇 |
1980年 | 29篇 |
1979年 | 18篇 |
1978年 | 22篇 |
1977年 | 14篇 |
1976年 | 15篇 |
1975年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
41.
《Allergology international》2019,68(3):335-341
BackgroundAlthough the guidelines in most countries do not recommend continuous inhalation of l-isoproterenol to treat pediatric patients with acute severe exacerbation of asthma, lower dose of l-isoproterenol has been widely used in Japan. To determine whether the efficacy of low-dose l-isoproterenol was superior to that of salbutamol, we conducted a double-blind, randomized controlled trial.MethodsHospitalized patients aged 1–17 years were eligible if they had severe asthma exacerbation defined by the modified pulmonary index score (MPIS). Patients were randomly assigned (1:1) to receive inhalation of l-isoproterenol (10 μg/kg/h) or salbutamol (500 μg/kg/h) for 12 hours via a large-volume nebulizer with oxygen. The primary outcome was the change in MPIS from baseline to 3 hours after starting inhalation. Trial registration number UMIN000001991.ResultsFrom December 2009 to October 2013, 83 patients (42 in the l-isoproterenol group and 41 in the salbutamol group) were enrolled into the study. Of these, one patient in the l-isoproterenol group did not receive the study drug and was excluded from the analysis. Compared with salbutamol, l-isoproterenol reduced MPIS more rapidly. Mean (SD) changes in MPIS at 3 hours were −2.9 (2.5) in the l-isoproterenol group and −0.9 (2.3) in the salbutamol group (difference −2.0, 95% confidence interval −3.1 to −0.9; P < 0.001). Adverse events occurred in 1 (2%) and 11 (27%) patients in the l-isoproterenol and salbutamol groups, respectively (P = 0.003). Hypokalemia and tachycardia occurred only in the salbutamol group.ConclusionsLow-dose l-isoproterenol has a more rapid effect with fewer adverse events than salbutamol. 相似文献
42.
Chenxi Song Rui Fu Jingang Yang Haiyan Xu Xiaojin Gao Lei Feng Yang Wang Xiaoxue Fan Bin Ning Shuping Wan Kefei Dou Yuejin Yang 《Nutrition, metabolism, and cardiovascular diseases : NMCD》2019,29(8):808-814
BackgroundThe relationship between body mass index (BMI) and in-hospital mortality risk among patients with acute myocardial infarction (AMI) remains controversial.Methods and ResultsWe included 35,964 patients diagnosed with AMI in China Acute Myocardial Infarction registry between January 2013 and December 2016. Patients were categorized into 4 groups according to BMI level: BMI <18.5, 18.5–24.9, 25–30, and ≥30 kg/m2 for underweight, normal, overweight, and obese groups, respectively. Clinical data were extracted for each patient, and multivariable logistic regression analysis was used to examine the association between BMI level and in-hospital mortality. Compared with normal-weight patients, obese patients were younger, more often current smokers, and more likely to have hypertension, hyperlipidemia, and diabetes. Multivariable regression analysis results demonstrated that compared with normal group, underweight group had significantly higher in-hospital mortality (odds ratio [OR]: 1.34; 95% confidence interval [CI]: 1.06–1.69; p = 0.016), while overweight group (OR: 0.86; 95% CI: 0.77–0.97; p = 0.011) and obese group (OR: 0.65; 95% CI: 0.46–0.91; p = 0.013) had lower mortality. All subgroups showed a trend toward lower in-hospital mortality risk as BMI increased.ConclusionsOur study provided robust evidence supporting “obesity paradox” in a contemporary large-scale cohort of patients with AMI and demonstrated that increased BMI was independently associated with lower in-hospital mortality. 相似文献
43.
《Asian nursing research.》2021,15(3):157-162
PurposeThis study develops a checklist with guidelines for the methods and important factors to consider in research using structural equation modeling (SEM).MethodThe paper discusses the factors to consider in the process across the three stages of 1) model setting, 2) model evaluation and modification, and 3) interpretation and reporting of SEM-based studies.ResultsThe authors present a checklist for researchers during the stages of model setting, model evaluation and modification, result analysis, and reporting, along with examples of figures and tables with explanations.ConclusionA checklist will help to improve the reporting quality of SEM-based studies. 相似文献
44.
《Journal of vascular and interventional radiology : JVIR》2019,30(9):1343-1350
PurposeTo identify risk factors for hypertensive crisis (HC) during ultrasound-guided percutaneous microwave (MW) ablation of adrenal neoplasms.Materials and MethodsPatients who underwent MW ablation for adrenal tumors between April 2006 and November 2017 were retrospectively identified for this study (51 consecutive patients; 35 males, 16 females; mean age, 55 years; range, 15–85 years). A total of 77 MW ablation treatments were performed for 67 tumors (24 primary [9 pheochromocytomas, 8 adenomas, and 7 cortical carcinomas]; and 43 metastases [22 hepatocellular carcinoma, 8 renal cell carcinoma, 5 non-small cell lung cancer, 4 colorectal cancer, 3 liposarcoma, and 1 malignant fibrous histiocytoma]). The mean diameter of the adrenal tumors was 4.6 cm (range, 1.2–16.2 cm). Information about patient demographics, imaging studies, pathology and laboratory results, procedure records, and clinical outcomes was retrieved and analyzed. Statistical analysis was then performed to determine potential risk factors for HC.ResultsOf the 77 MW ablation procedures, HC occurred in 13 (16.9%). A significantly higher risk of HC was observed in patients with pheochromocytoma (odds ratio [OR], 9.037; 95% confidence interval [CI], 1.731–47.172; P = .009), body mass index <24 kg/m2 (OR, 5.167; 95% CI, 1.060–25.194; P = .042), dominant tumor size ≤4.5 cm (OR, 4.023; 95% CI, 1.011–16.005; P = .048), and pre-procedural systolic blood pressure ≥130 mmHg (OR, 0.242; 95% CI, 0.068–0.861; P = .029).ConclusionHC can occur during MW ablation in patients with either primary or metastatic adrenal tumors. Pheochromocytoma, body mass index, tumor size, and pre-procedural systolic blood pressure appear to be significant risk factors for the occurrence of HC. 相似文献
45.
46.
47.
《Clinical neurophysiology》2019,130(9):1465-1473
ObjectiveTo assess the feasibility of motor unit number index (MUNIX) in the quantitative assessment of the cervical spondylotic amyotrophy (CSA).MethodsMUNIX was recorded bilaterally on the abductor pollicis brevis, abductor digiti minimi, biceps brachii and middle deltoid in 41 normal controls and 47 patients with CSA (distal-type to proximal-type ratio: 25 to 22). Additionally, patients were assessed on handgrip strength (HGS), the disabilities of arm, shoulder and hand (DASH) and Medical Research Council (MRC) scales. These examinations were re-evaluated approximately 18 months after surgery in 37 of these CSA patients.ResultsMUNIX values were noticeably lower in the mainly affected muscles of CSA patients than those in controls (P < 0.05), and 49.0% (51/104) of the tested muscles with abnormal MUNIX measurements showed normal muscle strength. Significant correlations between MUNIX measurements and both DASH and MRC scores were observed in both CSA patient groups (P < 0.05). Postoperative longitudinal follow-up analysis identified significant increase in motor unit number in both CSA patient groups within approximately 18 months (P < 0.05), with or without improved measures of motor function.ConclusionsA significant reduction in MUNIX values related to motor impairment was observed in CSA patients, even in the subclinical stage. Compared to measures of motor function, the MUNIX measurements in the patients with CSA improved more noticeably after surgical intervention.SignificanceMUNIX may serve as an available supplementary test to quantitatively evaluate the motor dysfunction in CSA and to track its progression, that is complementary to conventional electromyography. 相似文献
48.
Alexander E. J. Trevatt David R. Thomson Robert Miller Matthew Colquhoun Akinyemi I. Idowu Shakeel Rahman 《Journal of plastic surgery and hand surgery》2019,53(2):97-104
Academic output is just one aspect of a successful career as a plastic surgeon. However, for those with a strong interest in academia, the academic output of a department will likely be a key factor when deciding how to rank jobs. The aim of this study was to quantify and rank the academic output of plastic surgery units across the UK and Ireland. The Institute for Scientific Information (ISI) Web of Science Bibliometric analysis tool was used to collate cumulative (1950–2016), 10 year (2006–2016) and 3 years (2013–2015) research output data for plastic surgery units in the UK and Ireland. Sixty-six plastic surgery units were identified. Departments were ranked for each time period according to the number of papers produced, number of citations (Nc) and h-index (a measure of the impact of scientific output). The top 3 departments for number of papers in the last 10 years were The Royal Free Hospital, London (226) Broomfield Hospital, Chelmsford (218), and Morriston Hospital and Swansea (188). The top 3 for h-number were The Royal Free Hospital (21) Wythenshawe Hospital, Manchester (18) and Morriston Hospital (17). Academic output varies across plastic surgery units in the UK and Ireland. A number of departments have consistently maintained high academic outputs across the years and will be of interest to surgeons hoping to pursue a career in academia. 相似文献
49.
50.
Mark I. Evans Robert D. Eden David W. Britt Barry S. Schifrin 《The journal of maternal-fetal & neonatal medicine》2019,32(15):2561-2569
Background: Even key opinion leaders now concede that electronic fetal monitoring (EFM) cannot reliably identify fetal acidemia which many vouch as the only labor mediated pathophysiologic precursor for cerebral palsy (CP). We have developed the “Fetal Reserve Index” – an algorithm combining five dynamic components of EFM (1. Rate, 2. Variability, 3. Accelerations, 4. Decelerations, and 5. Excessive uterine activity) considered individually that are combined with the presence of: 6. maternal, 7. obstetrical, and 8. fetal risk factors.Objective: Here, we compare this 8-point fetal reserve index (FRI) against the performance of ACOG monograph criteria and ACOG Category systems for predicting risk for both CP and the need for emergency operative delivery (EOD). We then studied how varied management for screen positives (Red zone-defined below) impacts the outcome of such cases.Study design: Four hundred twenty term patients were studied: all entered labor with normal EFMs and no apparent cause of harm except events of labor and delivery. Sixty subsequently developed CP, and 360 were apparently normal controls. An FRI, normal on all eight parameters scored 100%, 4 of the 8 was 50%, etc. We divided cases into Green zone >50%, Yellow 50–26%, and Red ≤25%. An FRI in the Red zone was considered a positive screen. We then compared performance metrics for the three evaluation schemes and differences between controls that reached Red against those controls whose worst scores were Green/Yellow.Results: For detection of injury during labor, the FRI performed much better than the ACOG Category criteria (sensitivity 28%), and Category III (45%) (p?.001). All CP cases reached Red zone and were Red for a minimum of 2 hours (mean?=?5.35 hours). Twenty-four% of controls reached Red, but were only Red for average of 1?hr. The incidence of low Apgar’s, pH, FRI, and Lowest FRI increased progressively from Green/Yellow controls to red controls to CP cases. Irrespective, CP cases met ACOG Monograph criteria for labor injury less than 50% of the time. Only half of CP babies had umbilical artery pH values <7.00, and less than 50% showed Category III patterns. The earlier in labor the Red zone was reached, the more likely for a baby to develop CP or the mother to require an EOD regardless of fetal outcome. Successful intrauterine resuscitations (IR) diminished time spent in the Red zone and the need for EODs.Conclusions: FRI shows better discrimination for adverse fetal outcome and EOD than traditional EFM interpretation. The Category system is a very poor, subjective screening method as the vast majority of CP babies never reach the “action point” result of Category III. While reaching the Red zone does not ordain a bad outcome, how it is managed, does. Compared to CP cases, Red controls were delivered faster, had higher FRIs, and often had prompt management including IR maneuvers, which improved the FRI and lowered the risk of EODs even for cases with normal outcomes. With further study and validation, the quantitative FRI approach may replace the current, very subjective interpretation with a quantitative “lab test” approach. 相似文献