全文获取类型
收费全文 | 3050篇 |
免费 | 230篇 |
国内免费 | 79篇 |
专业分类
耳鼻咽喉 | 66篇 |
儿科学 | 19篇 |
妇产科学 | 19篇 |
基础医学 | 788篇 |
口腔科学 | 280篇 |
临床医学 | 380篇 |
内科学 | 193篇 |
皮肤病学 | 10篇 |
神经病学 | 333篇 |
特种医学 | 156篇 |
外科学 | 395篇 |
综合类 | 259篇 |
预防医学 | 46篇 |
眼科学 | 177篇 |
药学 | 142篇 |
1篇 | |
中国医学 | 81篇 |
肿瘤学 | 14篇 |
出版年
2024年 | 12篇 |
2023年 | 27篇 |
2022年 | 78篇 |
2021年 | 88篇 |
2020年 | 103篇 |
2019年 | 89篇 |
2018年 | 96篇 |
2017年 | 110篇 |
2016年 | 74篇 |
2015年 | 73篇 |
2014年 | 137篇 |
2013年 | 161篇 |
2012年 | 114篇 |
2011年 | 151篇 |
2010年 | 105篇 |
2009年 | 135篇 |
2008年 | 151篇 |
2007年 | 116篇 |
2006年 | 104篇 |
2005年 | 101篇 |
2004年 | 103篇 |
2003年 | 88篇 |
2002年 | 85篇 |
2001年 | 74篇 |
2000年 | 62篇 |
1999年 | 73篇 |
1998年 | 60篇 |
1997年 | 61篇 |
1996年 | 53篇 |
1995年 | 58篇 |
1994年 | 37篇 |
1993年 | 42篇 |
1992年 | 47篇 |
1991年 | 35篇 |
1990年 | 39篇 |
1989年 | 43篇 |
1988年 | 36篇 |
1987年 | 41篇 |
1986年 | 35篇 |
1985年 | 33篇 |
1984年 | 33篇 |
1983年 | 29篇 |
1982年 | 25篇 |
1981年 | 28篇 |
1980年 | 29篇 |
1979年 | 13篇 |
1978年 | 19篇 |
1977年 | 13篇 |
1976年 | 20篇 |
1974年 | 8篇 |
排序方式: 共有3359条查询结果,搜索用时 46 毫秒
91.
Comparison of metabolic adaptations between endurance‐ and sprint‐trained athletes after an exhaustive exercise in two different calf muscles using a multi‐slice 31P‐MR spectroscopic sequence
下载免费PDF全文
![点击此处可从《NMR in biomedicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Kevin Moll Alexander Gussew Maria Nisser Steffen Derlien Martin Krämer Jürgen R. Reichenbach 《NMR in biomedicine》2018,31(4)
Measurements of exercise‐induced metabolic changes, such as oxygen consumption, carbon dioxide exhalation or lactate concentration, are important indicators for assessing the current performance level of athletes in training science. With exercise‐limiting metabolic processes occurring in loaded muscles, 31P‐MRS represents a particularly powerful modality to identify and analyze corresponding training‐induced alterations. Against this background, the current study aimed to analyze metabolic adaptations after an exhaustive exercise in two calf muscles (m. soleus – SOL – and m. gastrocnemius medialis – GM) of sprinters and endurance athletes by using localized dynamic 31P‐MRS. In addition, the respiratory parameters VO2 and VCO2, as well as blood lactate concentrations, were monitored simultaneously to assess the effects of local metabolic adjustments in the loaded muscles on global physiological parameters. Besides noting obvious differences between the SOL and the GM muscles, we were also able to identify distinct physiological strategies in dealing with the exhaustive exercise by recruiting two athlete groups with opposing metabolic profiles. Endurance athletes tended to use the aerobic pathway in the metabolism of glucose, whereas sprinters produced a significantly higher peak concentration of lactate. These global findings go along with locally measured differences, especially in the main performer GM, with sprinters revealing a higher degree of acidification at the end of exercise (pH 6.29 ± 0.20 vs. 6.57 ± 0.21). Endurance athletes were able to partially recover their PCr stores during the exhaustive exercise and seemed to distribute their metabolic activity more consistently over both investigated muscles. In contrast, sprinters mainly stressed Type II muscle fibers, which corresponds more to their training orientation preferring the glycolytic energy supply pathway. In conclusion, we were able to analyze the relation between specific local metabolic processes in loaded muscles and typical global adaptation parameters, conventionally used to monitor the training status of athletes, in two cohorts with different sports orientations. 相似文献
92.
Letícia Zumpano Cardenas Pauliane Vieira Santana Pedro Caruso Carlos Roberto Ribeiro de Carvalho André Luís Pereira de Albuquerque 《Ultrasound in medicine & biology》2018,44(4):786-793
Diaphragm ultrasound (DUS) has been used to identify diaphragm dysfunction. However, its correlations with respiratory strength and lung function are unclear, even in healthy patients. A total of 64 healthy patients (30 males) had lung function and inspiratory strength (maximal inspiratory pressure and sniff nasal inspiratory pressure) measured. Gastric and oesophageal pressures were measured in a subgroup (n?=?40). DUS was characterized by mobility (quiet breathing [QB] and deep breathing [DB]) and thickness (at functional residual capacity [ThFRC] and total lung capacity [ThTLC]). We calculated the thickening fraction (TF). During QB, DUS was similar between sexes. However, during DB, females had lower mobility, thickness and TF than males. Mobility at DB, ThTLC and TF significantly correlated with lung function and inspiratory strength. These correlations were affected by sex. DUS correlated with inspiratory gastric pressure. In healthy patients, DUS correlated with lung function and inspiratory strength during DB. Significant differences between genders were noticeable when DUS was performed during DB. 相似文献
93.
ObjectiveTo investigate whether reorganization of muscle activity occurs in patients with chronic temporomandibular disorders (TMD) and, if so, how it is affected by symptomatology severity.MethodsSurface electromyography (sEMG) of masticatory muscles was made in 30 chronic TMD patients, diagnosed with disc displacement with reduction (DDR) and pain. Two 15-patient subgroups, with moderate (TMDmo) and severe (TMDse) signs and symptoms, were compared with a control group of 15 healthy subjects matched by age. The experimental tasks were: a 5 s inter-arch maximum voluntary clench (MVC); right and left 15 s unilateral gum chewing tests. Standardized sEMG indices characterizing masseter and temporalis muscles activity were calculated, and a comprehensive functional index (FI) was introduced to quantitatively summarize subjects’ overall performance. Mastication was also clinically evaluated.ResultsDuring MVC, TMDse patients had a significantly larger asymmetry of temporalis muscles contraction. Both TMD groups showed reduced coordination between masseter and temporalis muscles’ maximal contraction, and their muscular activity distribution shifted significantly from masseter to temporalis muscles. During chewing, TMDse patients recruited the balancing side muscles proportionally more than controls, specifically the masseter muscle. When comparing right and left side chewing, the muscles’ recruitment pattern resulted less symmetric in TMD patients, especially in TMDse. Overall, the functional index of both TMDmo and TMDse patients was significantly lower than that obtained by controls.ConclusionsChronic TMD patients, specifically those with severe symptomatology, showed a reorganized activity, mainly resulting in worse functional performances. 相似文献
94.
95.
Ultrasound of oral and masticatory muscles: Why every neuromuscular swallow team should have an ultrasound machine
下载免费PDF全文
![点击此处可从《Clinical anatomy (New York, N.Y.)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Lenie Van Den Engel‐Hoek Marloes Lagarde Nens Van Alfen 《Clinical anatomy (New York, N.Y.)》2017,30(2):183-193
Patients with neuromuscular disorders often present with swallowing difficulties due to oral phase problems and pharyngeal residue after swallow. It is important to assess the underlying pathology and cause of the swallowing disturbance in this patient group, such as dystrophic changes in oral and masticatory muscles. This allows for more patient‐tailored recommendations, for example optimal compensation strategies to maintain function for longer. Ultrasound can show structural changes caused by dystrophy or denervation of muscles, detect involuntary movements such as fasciculations, and provide dynamic video images of tongue motion during swallowing attempts. This article, based on the authors' extensive experience with ultrasound in neuromuscular disease, explains the concepts of oral muscle ultrasound and its proven value in assessing neuromuscular mastication and swallowing problems. As a patient‐friendly and portable technique, we advocate its use as a standard tool for analyzing neuromuscular dysphagia. Clin. Anat. 30:183–193, 2017. © 2017 Wiley Periodicals, Inc. 相似文献
96.
《Disability and rehabilitation》2013,35(2):46-49
An electromyographic investigation of inspiratory respiratory muscles was carried out in six tetraplegic and two normal subjects using needle electrodes. When the normal subjects were using tidal breathing there was no activity present. In the majority of tetraplegic subjects, activity was present in the scalene muscle during tidal breathing. This activity became more marked during deep inspiration. The muscles were hypertrophied and these muscles filled an important respiratory role. 相似文献
97.
98.
Heather L. Butler Cheryl L. Hubley-Kozey John W. Kozey 《European journal of applied physiology》2009,106(1):95-104
It is assumed when lifting with the dominant hand that the relationship between contralateral and ipsilateral trunk muscle
responses are similar to when lifting with the non-dominant hand. The purpose of this study was to quantify trunk muscle activation
amplitude patterns during right- and left-handed lifts. Surface electromyography (EMG) and kinematic variables were recorded
from 29 healthy subjects. Minimal trunk and pelvis motion was observed. Three principal patterns accounted for 95% of the
variation in the EMG data indicating minimal variation in the pattern. Significant differences in scores captured different recruitment strategies for reach and hand. Selective and differential recruitment of back sites characterized
lifts at greater distances from the body, whereas co-activation between internal oblique and back sites characterized lifts
closer to the body. While the results showed no handedness effect for back muscles, the external oblique responded differently
between right- and left-handed lifts. Specific recruitment strategies were used to account for subtle changes in reach and
asymmetrical demands. 相似文献
99.
Roya Eshaghi Moghadam Leila Rahnama Noureddin Karimi Mohsen Amiri Mahsa Rahnama 《Journal of bodywork and movement therapies》2018,22(3):643-647
Background
As one of the most common work-related musculoskeletal disorders and postural deviations, forward head posture (FHP), is considered to lead to muscle imbalance.Objectives
The aim of this study is to investigate the bilateral cross-sectional area (CSA) of the deep neck flexor muscles at rest and during five stages of the craniocervical flexion (CCF) test in individuals with FHP and the controls with normal head posture.Methods
Eighteen students with FHP and 18 controls with normal head posture, all females aged 18–35 years, participated in this study. Participants were categorized into two groups based on their craniovertebral angle. The CSA of the deep neck flexors was measured using ultrasonography while participants lay supine on the table with a pressure biofeedback unit placed under their necks in order to let the examiner measure the CSA of the muscles during rest and five stages of the CCF test including 22, 24, 26, 28, and 30 mmHg of the pressure biofeedback unit.Results
A significant effect of contraction level was observed in both groups, indicating significant increases of the CSA of the deep neck flexors during contraction (F = 64.37, P < 0.001). No significant difference was evident for the CSA of the deep neck flexors between the groups, although the increase in the CSA of the deep neck flexors was up to 28 mmHg in the normal head posture group compared to 26 mmHg in the FHP group.Conclusions
The results of the present study showed no significant difference between the performance of the deep neck flexors during the CCF test in FHP and normal head posture individuals, which challenge the common belief of the deep neck flexors weakness in individuals sustaining FHP. 相似文献100.
Nahid Rahmani Ali Kiani Mohammad Ali Mohseni-Bandpei Iraj Abdollahi 《Journal of bodywork and movement therapies》2018,22(1):147-151