全文获取类型
收费全文 | 5030篇 |
免费 | 212篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 95篇 |
儿科学 | 119篇 |
妇产科学 | 113篇 |
基础医学 | 739篇 |
口腔科学 | 98篇 |
临床医学 | 395篇 |
内科学 | 1131篇 |
皮肤病学 | 67篇 |
神经病学 | 467篇 |
特种医学 | 512篇 |
外科学 | 449篇 |
综合类 | 58篇 |
预防医学 | 221篇 |
眼科学 | 62篇 |
药学 | 461篇 |
2篇 | |
中国医学 | 1篇 |
肿瘤学 | 264篇 |
出版年
2022年 | 46篇 |
2021年 | 91篇 |
2020年 | 43篇 |
2019年 | 64篇 |
2018年 | 91篇 |
2017年 | 63篇 |
2016年 | 54篇 |
2015年 | 74篇 |
2014年 | 128篇 |
2013年 | 168篇 |
2012年 | 190篇 |
2011年 | 237篇 |
2010年 | 155篇 |
2009年 | 176篇 |
2008年 | 178篇 |
2007年 | 195篇 |
2006年 | 218篇 |
2005年 | 212篇 |
2004年 | 187篇 |
2003年 | 179篇 |
2002年 | 157篇 |
2001年 | 153篇 |
2000年 | 136篇 |
1999年 | 123篇 |
1998年 | 124篇 |
1997年 | 108篇 |
1996年 | 106篇 |
1995年 | 90篇 |
1994年 | 58篇 |
1993年 | 70篇 |
1992年 | 44篇 |
1991年 | 63篇 |
1990年 | 87篇 |
1989年 | 112篇 |
1988年 | 99篇 |
1987年 | 120篇 |
1986年 | 100篇 |
1985年 | 132篇 |
1984年 | 68篇 |
1983年 | 59篇 |
1982年 | 49篇 |
1981年 | 45篇 |
1980年 | 50篇 |
1979年 | 38篇 |
1978年 | 31篇 |
1977年 | 37篇 |
1976年 | 26篇 |
1975年 | 31篇 |
1974年 | 28篇 |
1971年 | 25篇 |
排序方式: 共有5254条查询结果,搜索用时 15 毫秒
1.
Edward J.A. Harris Steven Kao Brian McCaughan Takashi Nakano Nobuyuki Kondo Rebecca Hyland Anna K. Nowak Nicholas H. de Klerk Fraser J.H. Brims 《Journal of thoracic oncology》2019,14(2):288-293
Introduction
Malignant pleural mesothelioma (MPM) is an uncommon cancer with a poor prognosis and heterogeneous survival. Surgery for MPM is offered in some specialist centers to highly selected patients. A previously described classification and regression tree (CART) model stratified survival in unselected MPM patients using routinely collected clinical data. This study aimed to examine the performance of this CART model on a highly selected surgical population.Methods
Data were collected from subjects undergoing cytoreductive surgery for MPM from specialist centers in Hyõgo, Japan, and Sydney, Australia, between 1991 and 2016. The CART model was applied using the combination of clinical variables to stratify subjects into risk groups (1 through 4); survival characteristics were then compared.Results
Two hundred eighty-nine cases were included (205 from Australia, 84 from Japan). Overall median survival was 34.6 (interquartile range: 17.5–56.1) months; median age was 63.0 (interquartile range: 57.0–67.8) years, and 83.0% (n = 240) were male. There were no clinically meaningful differences between the two cohorts. Survival across the four risk groups was significantly different (p < 0.0001); the model stratified survival well with a Harrell's concordance statistic of 0.62 (95% confidence interval: 0.57–0.66) at 36 months. The group with the longest survival (median, 82.5 months) had: no weight loss, hemoglobin > 153 g/L and serum albumin > 43 g/L at time of referral to the surgical center.Conclusions
Using routinely available clinical variables, the CART model was able to stratify surgical patients into risk groups with statistically different survival characteristics with fair to good performance. Presence of weight loss, anemia, and low albumin should confer caution when considering surgical therapy for MPM. 相似文献2.
Nowak AJ 《Pediatric dentistry》2002,24(3):227-228
PURPOSE: The objective of this study was to determine the involvement of pediatric dentists in practice in managing patients with special health care needs (SCHN) upon completion of training. METHODS: A questionnaire was developed, pilot tested, modified and sent to a randomly selected sample of 950 pediatric dentists in practice who were active and fellow members of the American Academy of Pediatric Dentistry. RESULTS: Fifty-one percent of the dentists responded. The majority were males between the ages of 41 and 50 years. Most practiced in communities with over 500,000 citizens. Most were trained in hospital-based programs, and 84% reported comprehensive didactic courses on SHCN patients during training. SCHN patients were routinely appointed in an integrated schedule in their practices. Seventy-one percent of responders continue to follow the patients after 21 years of age. Most had buildings and offices that were handicapped accessible. Patient profiles remained similar since initiating private practice with notable increases reported in the new and recall patients and patients with complicated medical histories categories. CONCLUSIONS: The results of this survey demonstrate the continuing involvement of pediatric dentists in private practice in scheduling and treating patients with special health care needs after the completion of training. 相似文献
3.
Gijbels F Sanderink G Wyatt J Van Dam J Nowak B Jacobs R 《British dental journal》2004,197(3):149-52; discussion 140
AIM: The aim of this study was to measure organ doses and calculate the effective dose for indirect and direct digital cephalometric exposures. MATERIAL AND METHODS: Indirect digital cephalometric exposures were made of a Rando phantom head using a Cranex Tome multipurpose unit with storage phosphor plates from Agfa and the direct digital (Charge Coupled Device, CCD) exposures were made with a Proline Ceph CM unit. Exposure settings were 70 kV and 4 mAs for indirect digital exposures. Direct digital exposures were made with 70 kV, 10 mA and a total scanning time of 23 s. TLD700 dosemeters were used to measure organ doses, and the effective doses were calculated with (effective dose(sal)) and without inclusion of the salivary glands. A pilot study was carried out to compare diagnostic image quality of both imaging modalities. RESULTS: Effective doses were 1.7 microSv for direct digital and 1.6 microSv for indirect digital cephalometric imaging. When salivary glands were included in the calculation, effective doses(sal) were 3.4 microSv and 2.2 microSv respectively. Organ doses were higher for direct digital imaging, except for the thyroid gland, where the organ doses were comparable. Diagnostic image quality of indirect and direct digital cephalometric images seemed comparable. CONCLUSION: Effective dose and effective dose(sal) were higher for direct digital cephalometric exposure compared with indirect digital exposure. Organ doses were higher for direct digital cephalography. From preliminary data, it may be presumed that diagnostic image quality of indirect and direct digital cephalometric images are comparable. 相似文献
4.
Lynn J. White MS Jeffrey S. Jones MD Christopher W Felton MD Linda C. Pool RA 《Academic emergency medicine》1996,3(8):745-750
Objective: To identify common discrepancies and average reading grade levels for informed consent forms (ICFs) us submitted to institutional review boards (IRBs) by medical researchers.
Methods: A retrospective evaluation of ICFs as submitted to IRBs of 3 university-affiliated hospitals during a I-year period. ICF content was evaluated using a checklist of 23 requirements specified in the federal regulations governing human research. Documents then were computer-analyzed to determine the readability scores using 2 common indexes of comprehension. A discrepancy was defined as any instance in which an ICF did not address an applicable requirement in the Code of Federal Regulations.
Results: Eighty-two ICFs representing 16 medical specialties were evaluated; 8 (10%) were from emergency medicine. Eighteen ICFs (22%) were conspicuously incomplete, lacking 29 federal requirements. The mean number of discrepancies was 4.7 (95% CI, 3.9–5.5) Common omissions included: a statement about who is doing the research, number of subjects in the study, circumstances when a subject's participation may be terminated, disclosure of alternative procedures, and notice to subjects regarding new findings. The mean Flesch grade level required to read all ICFs was 13.8 (95% CI, 13.5–14.2), implying that the majority of the U.S. adult population would be unable to comprehend these forms.
Conclusion: Designing a consent form to meet all of the federal requirements while maintaining a level of reading comprehension suitable for the general population is a difficult task for investigators. 相似文献
Methods: A retrospective evaluation of ICFs as submitted to IRBs of 3 university-affiliated hospitals during a I-year period. ICF content was evaluated using a checklist of 23 requirements specified in the federal regulations governing human research. Documents then were computer-analyzed to determine the readability scores using 2 common indexes of comprehension. A discrepancy was defined as any instance in which an ICF did not address an applicable requirement in the Code of Federal Regulations.
Results: Eighty-two ICFs representing 16 medical specialties were evaluated; 8 (10%) were from emergency medicine. Eighteen ICFs (22%) were conspicuously incomplete, lacking 29 federal requirements. The mean number of discrepancies was 4.7 (95% CI, 3.9–5.5) Common omissions included: a statement about who is doing the research, number of subjects in the study, circumstances when a subject's participation may be terminated, disclosure of alternative procedures, and notice to subjects regarding new findings. The mean Flesch grade level required to read all ICFs was 13.8 (95% CI, 13.5–14.2), implying that the majority of the U.S. adult population would be unable to comprehend these forms.
Conclusion: Designing a consent form to meet all of the federal requirements while maintaining a level of reading comprehension suitable for the general population is a difficult task for investigators. 相似文献
5.
Richard K. Englehardt Brent M. Nowak Michael V. Seger Frank D. Duperier 《JSLS, Journal of the Society of Laparoendoscopic Surgeons》2014,18(3)
Background and Objectives:
Aerosolized droplets of blood can travel considerable distances on release of intra-abdominal pressure during laparoscopic surgery. This creates an environmental hazard for members of the surgical team. This study describes and provides a method of measurement of aerosolized blood contamination during evacuation of the pneumoperitoneum in laparoscopic surgery.Methods:
Samples were measured by removing a trocar from the abdomen while a pneumoperitoneum of 15 mm Hg was present. A white poster board was placed 24 inches above the incision to catch the released blood spatter. By use of machine vision, luminol fluorescence, and computerized spatial analysis, data from the boards were recorded, analyzed, and scored based on the distance, size, and quantity of particulate contamination.Results:
We analyzed 27 boards. Spatter was present on every board. The addition of luminol to the boards increased the amount of visible spatter. Most tests created <1000 blood spatters. Fluids are typically ejected as a fine mist. Every test included at least 1 blood spatter. The range of the average blood spatter size was 0.53 × 10–3 to 7.11 × 10–3 sq in. The amount of spatter detected did not show any apparent correlation with the patient''s body mass index, the estimated blood loss, or the type of operation performed.Conclusions:
Evacuation of the pneumoperitoneum during laparoscopic surgery results in consistent contamination. Most blood spatter is not visible to the naked eye. Our results suggest that all surgical participants should wear appropriate protective barriers and conscious measures should be undertaken to prevent environmental contamination during pneumoperitoneal evacuation. 相似文献6.
G. Wasilewski P. Przybyłowski L. Janik E. Nowak J. Sadowski J. Małyszko 《Transplantation proceedings》2014
Introduction
Renalase may degrade catecholamines and regulate sympathetic tone and blood pressure. The aim of this study was to assess dopamine, norepinephrine, and renalase in 80 heart transplant recipients and 22 healthy volunteers and their correlations with heart rate, blood pressure control, type of hypotensive therapy, and renal function.Patients and Methods
Renalase, dopamine, and norepinephrine were studied by using commercially available assays.Results
Renalase levels were higher in heart transplant recipients compared with healthy volunteers, and noradrenaline levels were lower in the studied cohort patients than in the healthy volunteers. Noradrenaline was correlated with white blood cell count (r = −0.21, P < .05), copeptin (r = 0.41, P < .01), and left ventricular diameter (r = −0.29, P < .05), whereas dopamine was correlated in univariate analysis with white blood cell count (r = −0.22, P < .05), posterior wall of left ventricular diameter (r = 0.58, P < .01), and left atrium diameter (r = −0.31, P < .05). Neither noradrenaline nor dopamine was correlated with heart rate, blood pressure, kidney function, or New York Heart Association class. Noradrenaline was significantly higher in patients with elevated diastolic blood pressure (>90 mm Hg) compared with those with normal diastolic blood pressure (P < .05). Renalase was related to kidney function but was unrelated to catecholamines.Conclusions
Elevated renalase levels in heart transplant patients were related to kidney function but not linked to the sympathetic nervous system activity in this study population. In heart transplant recipients, these findings might suggest that sympathetic denervation and the modulation of β-receptors persist. 相似文献7.
G. Wasilewski P. Przybylowski L. Janik E. Nowak J. Sadowski J. Malyszko 《Transplantation proceedings》2014
Introduction
Cardiac transplantation is the definitive therapy for eligible patients with end-stage heart failure. Hypertension is a widely accepted risk factor for its outcome.Patients and Methods
We analyzed 169 heart transplant recipients. The diagnosis of hypertension was made on the basis of information gathered at 3 consecutive visits. Complete blood count, urea, serum lipids, fasting glucose, creatinine, and N-terminal pro–B-type natriuretic peptide were also studied.Results
In the orthotopic heart transplantation (OHT) population, 11% had diabetes and 68% had chronic kidney disease. Hypertension was diagnosed and treated in 68% of the OHT patients. Hypertensive patients were significantly older, with a lower estimated glomerular filtration rate and higher serum creatinine and erythrocyte count. Thirty-three percent of patients did not achieve target blood pressure despite optimal medical treatment. Patients treated with tacrolimus had similar systolic blood pressure compared with those treated with cyclosporine (with a tendency to have lower values). Patients treated with mammalian target of rapamycin inhibitors had similar systolic and diastolic blood pressures compared with those treated without these inhibitors. In the group of patients given steroids, systolic and diastolic blood pressures were significantly lower than in the group not treated with steroids. In addition, steroid-treated patients had a significantly lower estimated glomerular filtration rate, hemoglobin, and erythrocyte count and higher serum creatinine, N-terminal pro–B-type natriuretic peptide, and New York Heart Association class. Chronic kidney disease was also more prevalent in this group. Blood pressure was not related to the kidney function.Conclusions
Despite polytherapy, optimal blood pressure control was not achieved in the majority of patients. OHT patients have a high prevalence of hypertension, which should be treated adequately. More efforts should be made to optimize blood pressure control, particularly when other comorbidities are present. Blood pressure was not related to patient kidney function. 相似文献8.
9.
10.