全文获取类型
收费全文 | 1794篇 |
免费 | 116篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 65篇 |
儿科学 | 43篇 |
妇产科学 | 69篇 |
基础医学 | 185篇 |
口腔科学 | 61篇 |
临床医学 | 170篇 |
内科学 | 309篇 |
皮肤病学 | 32篇 |
神经病学 | 109篇 |
特种医学 | 63篇 |
外科学 | 240篇 |
综合类 | 46篇 |
预防医学 | 139篇 |
眼科学 | 66篇 |
药学 | 191篇 |
中国医学 | 40篇 |
肿瘤学 | 97篇 |
出版年
2024年 | 7篇 |
2023年 | 29篇 |
2022年 | 80篇 |
2021年 | 98篇 |
2020年 | 73篇 |
2019年 | 87篇 |
2018年 | 97篇 |
2017年 | 79篇 |
2016年 | 65篇 |
2015年 | 69篇 |
2014年 | 88篇 |
2013年 | 96篇 |
2012年 | 147篇 |
2011年 | 128篇 |
2010年 | 71篇 |
2009年 | 60篇 |
2008年 | 112篇 |
2007年 | 77篇 |
2006年 | 81篇 |
2005年 | 58篇 |
2004年 | 44篇 |
2003年 | 47篇 |
2002年 | 44篇 |
2001年 | 20篇 |
2000年 | 16篇 |
1999年 | 17篇 |
1998年 | 12篇 |
1997年 | 9篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1992年 | 7篇 |
1991年 | 5篇 |
1990年 | 13篇 |
1989年 | 10篇 |
1988年 | 10篇 |
1987年 | 10篇 |
1986年 | 5篇 |
1985年 | 8篇 |
1984年 | 8篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1973年 | 1篇 |
1969年 | 2篇 |
1928年 | 1篇 |
排序方式: 共有1925条查询结果,搜索用时 15 毫秒
11.
Abhinandan Kumar Vatika Soni Pardeep Singh Aftab Aslam Parwaz Khan Mohammed Nazim Satyabrata Mohapatra Vipin Saini Pankaj Raizada Chaudhery Mustansar Hussain Mohamed Shaban Hadi M. Marwani Abdullah M. Asiri 《RSC advances》2022,12(22):13609
The selection of a facile, eco-friendly, and effective methodology is the need of the hour for efficient curing of the COVID-19 virus in air, water, and many food products. Recently, semiconductor-based photocatalytic methodologies have provided promising, green, and sustainable approaches to battle against viral activation via the oxidative capabilities of various photocatalysts with excellent performance under moderate conditions and negligible by-products generation as well. Considering this, recent advances in photocatalysis for combating the spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are inclusively highlighted. Starting from the origin to the introduction of the coronavirus, the significant potential of photocatalysis against viral prevention and -disinfection is discussed thoroughly. Various photocatalytic material-based systems including metal-oxides, metal-free and advanced 2D materials (MXenes, MOFs and COFs) are systematically examined to understand the mechanistic insights of virus-disinfection in the human body to fight against COVID-19 disease. Also, a roadmap toward sustainable solutions for ongoing COVID-19 contagion is also presented. Finally, the challenges in this field and future perspectives are comprehensively discussed involving the bottlenecks of current photocatalytic systems along with potential recommendations to deal with upcoming pandemic situations in the future.Photocatalysts are green, eco-friendly, clean and sustainable and could be a solution to combat COVID-19 because of potential features of various types of metal oxides against viral inactivation via the generation of reactive oxidative species. 相似文献
12.
Miwa Yamaguchi Panrawee Praditsorn Sintha Dewi Purnamasari Kitti Sranacharoenpong Yusuke Arai Samantha M. Sundermeir Joel Gittelsohn Hamam Hadi Nobuo Nishi 《Nutrients》2022,14(9)
Access to healthy food is a necessity for all people. However, there is still a lack of reviews on the assessment of respondent-based measures of neighborhood food environments (perceived food environments). The aim of this systematic review was to evaluate the measurement tools for perceived food environments by five dimensions of food access and to obtain the overview of their associations with dietary habits among people aged 18 years and older in middle- and high-income countries. Observational studies using perceived food environment measures were identified through a systematic review based on two databases for original studies published from 2010 to 2020. A total of 19 final studies were extracted from totally 2926 studies. Pertaining to the five dimensions of food access, 12 studies dealt with accessibility, 13 with availability, 6 with affordability, 10 with acceptability, 2 with accommodation, and 8 with a combination of two or more dimensions. Perceived healthy food environments were positively associated with healthy dietary habits in 17 studies, but 8 of them indicated statistically insignificant associations. In conclusion, this review found accessibility and availability to be major dimensions of perceived food environments. The relationship between healthy food environments and healthy diets is presumably positive and weak. 相似文献
13.
Amirjamshidi A Roozbeh H Sharifi G Abdoli A Abbassioun K 《Journal of neurosurgery. Spine》2010,13(6):707-714
Osteoid osteoma affects the spine in only 10% of cases. More than 50% of the spinal cases involve the lumbar and cervical vertebrae. Involvement of C-1 and C-2 vertebrae has previously been reported only very rarely in the published literature. The authors report 4 cases of upper cervical osteoid osteoma, 1 involving C-1 and the other 3 C-2, and they discuss different aspects of management in similar cases. The patients were 14, 17, 35, and 46 years old, and all presented with neck pain and various degrees of painful limitation of head rotation not ameliorated by ordinary analgesics. Radionuclide isotope bone scans, CT scanning, and MR imaging were helpful preoperative diagnostic modalities. The first attempt at eradication of the lesions failed in 2 cases and the lesions could be excised totally at a second approach. Postoperatively, the patients all became pain free and gained full range of neck motion. There has been no tumor recurrence and no sign of instability in short- to medium-term follow-up. Among the several etiologies mentioned for neck pain and torticollis, osteoid osteoma of the first 2 cervical vertebrae should be considered as a possible but rare cause. Even though different kinds of management have been mentioned for osteoid osteoma, resection of the lesion remains the best option for achieving a cure. 相似文献
14.
Altered Integration of Structural Covariance Networks in Young Children With Type 1 Diabetes 下载免费PDF全文
S.M. Hadi Hosseini Paul Mazaika Nelly Mauras Bruce Buckingham Stuart A. Weinzimer Eva Tsalikian Neil H. White Allan L. Reiss for the Diabetes Research in Children Network 《Human brain mapping》2016,37(11):4034-4046
Type 1 diabetes mellitus (T1D), one of the most frequent chronic diseases in children, is associated with glucose dysregulation that contributes to an increased risk for neurocognitive deficits. While there is a bulk of evidence regarding neurocognitive deficits in adults with T1D, little is known about how early‐onset T1D affects neural networks in young children. Recent data demonstrated widespread alterations in regional gray matter and white matter associated with T1D in young children. These widespread neuroanatomical changes might impact the organization of large‐scale brain networks. In the present study, we applied graph‐theoretical analysis to test whether the organization of structural covariance networks in the brain for a cohort of young children with T1D (N = 141) is altered compared to healthy controls (HC; N = 69). While the networks in both groups followed a small world organization—an architecture that is simultaneously highly segregated and integrated—the T1D network showed significantly longer path length compared with HC, suggesting reduced global integration of brain networks in young children with T1D. In addition, network robustness analysis revealed that the T1D network model showed more vulnerability to neural insult compared with HC. These results suggest that early‐onset T1D negatively impacts the global organization of structural covariance networks and influences the trajectory of brain development in childhood. This is the first study to examine structural covariance networks in young children with T1D. Improving glycemic control for young children with T1D might help prevent alterations in brain networks in this population. Hum Brain Mapp 37:4034–4046, 2016. © 2016 Wiley Periodicals, Inc . 相似文献
15.
Afshar R Fong TS Latifi MH Kanthan SR Kamarul T 《The Journal of hand surgery, European volume》2012,37(5):396-401
The use of bicortical screws to fix metacarpal fractures has been suggested to provide no added biomechanical advantage over unicortical screw fixation. However, this was only demonstrated in static loading regimes, which may not be representative of biological conditions. The present study was done to determine whether similar outcomes are obtained when cyclic loading is applied. Transverse midshaft osteotomies were created in 20 metacarpals harvested from three cadavers. Fractures were stabilised using 2.0 mm mini fragment plates fixed with either bicortical or unicortical screw fixation. These fixations were tested to failure with a three-point bending cyclic loading protocol using an electromechanical microtester and a 1 kN load cell. The mean load to failure was 370 N (SD 116) for unicortical fixation and 450 N (SD 135) for bicortical fixation. Significant differences between these two constructs were observed. A biomechanical advantage was found when using bicortical screws in metacarpal fracture plating. 相似文献
16.
Pejman Shadpour Reza Kaffash Nayyeri Reza Daneshvar Hormoz Salimi Hadi Radfar 《BJU international》2012,110(11):1814-1818
Study Type – Therapy (case series) Level of Evidence 4 What's known on the subject? and What does the study add? Laparoscopic pyeloplasty has replaced open pyeloplasty as the new standard of care and we, among others, have even proven its applicability to redo surgery. The focus is now on limiting morbidity. One technical modification to this end is transmesocolic (TM) exposure of the PUJ. This randomized study pinpoints the objective benefits of TM exposure of the PUJ compared with standard colon reflection, and its results showed a 23% conservation in operating time.
OBJECTIVE
- ? To compare the efficacy and safety of colon‐reflecting (CR) and transmesocolic (TM) laparoscopic pyeloplasty approaches in a prospective randomized non‐selective setting.
PATIENTS AND METHODS
- ? Excluding only those patients with a history of abdominal surgery, all consenting patients scheduled for laparoscopic pyeloplasty of left‐sided pelvi‐ureteric junction (PUJ) obstruction between December 2004 and November 2007 were randomized into one of two groups: laparoscopic pyeloplasty using the standard CR approach or laparoscopic pyeloplasty through the TM aperture.
- ? All patients underwent dismembered repair by a single expert and were followed by diuretic renogram and urography at 4 months postoperatively and by annual diuretic renogram thereafter.
- ? Four discrete task phases were timed for comparison: trochar to PUJ, dismembering and spatulation, stenting and anastomosis.
RESULTS
- ? Sixty‐four patients were randomized into two groups, TM or CR, with 32 patients in each.
- ? The groups were similar, with no significant difference in sex, age, initial renal function or body mass index. Forty‐seven patients were ≤15 years old.
- ? The mean (sd ) operating time was 23% shorter in the TM group, owing mostly to the much shorter trochar to PUJ phase (5.0 [3.2] min in the TM group vs 35.8 [10.3] in the CR group; P < 0.001). The mean hospitalization time was shorter in the TM group than in the CR group (2.9 vs 3.6 days; P < 0.001).
- ? Thirty‐one of 32 patients in each group (96.9%) achieved a durable cure.
CONCLUSION
- ? Transmesocolic exposure of left‐sided PUJ obstruction is superior to standard CR exposure, in that it saves anaesthesia time, hospitalization time and has lower morbidity with no compromise in efficiency, and could be considered as the new standard approach.
17.
Identification of myoepithelial cells using antibodies to cytoskeletal proteins, such as smooth muscle myosin heavy chain (SMM-HC) and calponin, can play an important role in distinguishing invasive carcinoma from its histologic mimics. However, antibodies to these proteins may also cross-react with stromal myofibroblasts and vascular smooth muscle cells. It has recently been demonstrated that myoepithelial cells express the nuclear protein, p63, a member of the p53 gene family. We compared the patterns of reactivity of antibodies with p63, calponin, and SMM-HC on 85 breast lesions, including 11 cases of sclerosing adenosis, 33 cases of ductal carcinoma in situ, including 10 that showed microinvasion, 6 cases of lobular carcinoma in situ, and 35 cases of infiltrating ductal carcinoma. All three antibodies were positive on the vast majority of myoepithelial cells in all cases. A small minority of cases showed focal gaps in the revealed myoepithelial cell layer, reflected in discontinuous positive immunostaining around noninvasive epithelial nests (including ductal carcinoma in situ). No case showed p63 expression by myofibroblasts or vascular smooth muscle cells, whereas myofibroblasts expressed, in 8% and 76% of cases, SMM-HC and calponin, respectively. Although no tumor cell reactivity was noted with antibodies to calponin or SMM-HC, tumor cells in 11% of cases showed at least focal p63 expression. And although antibodies to p63 offer excellent sensitivity and increased specificity for myoepithelial detection relative to antibodies to calponin and SMM-HC, they have the following diagnostic limitations: 1) they occasionally demonstrate an apparently discontinuous myoepithelial layer, particularly around ductal carcinoma in situ, and 2) they react with a small but significant subset of breast carcinoma tumor cells. p63 may represent a myoepithelial marker that can complement or replace SMM-HC and/or calponin in the analysis of difficult breast lesions. 相似文献
18.
19.
Takafumi Yanagisawa Tatsushi Kawada Hadi Mostafaei Reza Sari Motlagh Fahad Quhal Ekaterina Laukhtina Pawel Rajwa Markus von Deimling Alberto Bianchi Maximilian Pallauf Benjamin Pradere Pierre I. Karakiewicz Jun Miki Takahiro Kimura Shahrokh F. Shariat 《BJU international》2023,132(2):132-145
Objectives
To assess the clinical value of routine pelvic drain (PD) placement and early removal of urethral catheter (UC) in patients undergoing robot-assisted radical prostatectomy (RARP), as perioperative management such as the necessity of PD or optimal timing for UC removal remains highly variable.Methods
Multiple databases were searched for articles published before March 2022 according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statement. Studies were deemed eligible if they investigated the differential rate of postoperative complications between patients with/without routine PD placement and with/without early UC removal, defined as UC removal at 2–4 days after RARP.Results
Overall, eight studies comprising 5112 patients were eligible for the analysis of PD placement, and six studies comprising 2598 patients were eligible for the analysis of UC removal. There were no differences in the rate of any complications (pooled odds ratio [OR] 0.89, 95% confidence interval [CI] 0.78–1.00), severe complications (Clavien–Dindo Grade ≥III; pooled OR 0.95, 95% CI 0.54–1.69), all and/or symptomatic lymphocele (pooled OR 0.82, 95% CI 0.50–1.33; and pooled OR 0.58, 95% CI 0.26–1.29, respectively) between patients with or without routine PD placement. Furthermore, avoiding PD placement decreased the rate of postoperative ileus (pooled OR 0.70, 95% CI 0.51–0.91). Early removal of UC resulted in an increased likelihood of urinary retention (OR 6.21, 95% CI 3.54–10.9) in retrospective, but not in prospective studies. There were no differences in anastomosis leakage and early continence rates between patients with or those without early removal of UC.Conclusions
There is no benefit for routine PD placement after standard RARP in the published articles. Early removal of UC seems possible with the caveat of the increased risk of urinary retention, while the effect on medium-term continence is still unclear. These data may help guide the standardisation of postoperative procedures by avoiding unnecessary interventions, thereby reducing potential complications and associated costs. 相似文献20.
OBJECTIVE: Here, we report the results of a randomized controlled trial (RCT) assessing the efficacy of emergency ESWL (eESWL) on the short-term outcome of symptomatic ureteral stones. MATERIAL: The trial enrolled 100 patients admitted in emergency room for renal colic caused by a ureteral radioopaque [corrected] stone. Patients were randomized to medical therapy alone or combined with eESWL. eESWL was performed within 6 hours of the onset of renal colic without specific analgesia on a Lithostar lithotripter (Siemens Medical, Munich, Germany). The primary endpoints were the proportion of patients stone free rate after 48 hours (SF-48) and the cumulative proportion of patients discharged from the hospital after 48 and 72 hours. RESULTS: Ureteral stone's location was proximal and distal in respectively 46% and 54% of the patients; stone's mean size was 5.5 mm (range 2-10 mm). Median hospital stay was 3 days, ranging from 1 to 14 days. SF-48 in the control group varied from 76% for distal stones <5 mm to 28.6% for proximal stones >5 mm, averaging at 61%. On average, eESWL increased SF-48 by 13% (p: 0.126), the gain strictly depending on stone size and location. SF-48 increase ranged from 40% for proximal stones >5 mm to 1.8% for distal stone <5 mm. On average, eESWL increased the median duration of hospital stay by one day. This mean negative impact results from ESWL increasing significantly the duration of hospital stay in case of distal stone, while slightly shortened it for stones located proximally. CONCLUSION: This study demonstrated for the first time that rapidly performed ESWL is a valuable therapeutic option to improve elimination of ureteral stones and shorten duration of hospital stay, proven that the stone is located proximally to the iliac vessels. 相似文献