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71.
72.
The effects of external resistance on the recruitment of trunk muscles and the role of intrinsic and reflexive mechanisms to ensure the spinal stability are significant issues in spinal biomechanics. A computational model of spine under the control of 48 anatomically oriented muscle actions was used to simulate iso-resistive trunk movements. Neural excitation of muscles was attained based on inverse dynamics approach along with the stability-based optimization. The effect of muscle spindle reflex response on the trunk movement stability was evaluated upon the application of a perturbation moment. In this study, the trunk extension movement at various resistance levels while extending from 60 degrees flexion to the upright posture was investigated. Incorporation of the stability condition as an additional constraint in the optimization algorithm increased antagonistic activities for all resistance levels demonstrating that the co-activation caused an increase in the intrinsic stiffness of the spine and its stability in a feed-forward manner. During the acceleration phase of the movement, extensors activity increased while flexors activity decreased in response to the higher resistance. The co-activation ratio noticed in the braking phase of the movement increased with higher resistance. In presence of a 30 Nm flexion perturbation moment, reflexive feed-back noticeably decreased the induced deviation of the velocity and position profiles from the desired ones at all resistance levels. The stability-generated co-activation decreased the reflexive response of muscle spindles to the perturbation demonstrating that both intrinsic and reflexive mechanisms contribute to the trunk stability. The rise in muscle co-activation can ameliorate the corruption of afferent neural sensory system at the expense of higher loading of the spine.  相似文献   
73.
Deaths from infectious diseases and deep concerns about increases in microbial resistance make it necessary for scientists to develop innovative therapeutic solutions and complementary therapies. Growing evidence is available on the therapeutic effects of probiotics. There are also documents about the beneficial effects of probiotics, but it is difficult to draw a definitive conclusion regarding the results of these studies because of the small sample size, the limitations of the study methods, and the use of different strains of probiotic bacteria. This review study summarizes the articles available on the scientific and electronic databases Embase, Medline, and Scopus until the end of 2017, including case studies describing beneficial microbes as tools for improving the process of controlling infectious diseases. Until the development of novel vaccines or other approaches occurs, the use of probiotics seems to be a logical way to attempt to control certain infectious diseases.  相似文献   
74.
INTRODUCTION: While the undisplaced acetabular fractures have a good prognosis after conservative treatment, the management of the displaced fractures has been a controversial issue over the last decades with variable results in their treatment and prognosis. Anatomical reduction can be only achieved operatively. The long term outcome of 209 patients with displaced acetabular fractures treated by open reduction and internal fixation was presented. MATERIAL AND METHODS: Between 1972 and 1996, 209 patients with a mean age of 38 years (15-62a) were treated for displaced acetabular fractures operatively. 161 patients could be followed up over a period of 2 to 20 years. The function of the hip joint in correlation with radiological results was evaluated according to the scheme of Merle d'Aubinge. RESULTS: Patients with single column fractures showed 90% good or excellent results followed by 55% good or excellent results in patients with transverse fractures. The highest rates of complication (20% osteoarthritis, 6% femoral head necrosis, 9% heterotopic ossification) were observed in both column fractures and in transverse and posterior wall fractures. Deep infection was observed in 6 cases (4%), superficial wound infection in 8 cases (5%). Primary sciatic nerve palsy was seen in 10 cases (6%) and postoperative peroneal nerve palsy in 6 cases (4%), all of which improved during the rehabilitation period. CONCLUSION: Displaced acetabular fractures of the weight bearing part of the dome, i.e. transtectal fractures, should be treated operatively. The operation should preferably be performed within one week after the injury.  相似文献   
75.
Polymorphic ventricular tachycardia (PVT) is a form of ventricular tachycardia characterized by QRS complexes that seem to change direction during the tachycardia. If associated with a prolonged QT interval, it is called torsades de pointes. In the absence of a congenital long QT syndrome, torsades is seen with certain drugs such as antiarrhythmic agents (Class IA, IC, III), psychotropic medications, antidepressants, antihistamines, and electrolyte disturbances. We report the first case of polymorphic ventricular tachycardia with normal QT interval associated with the oral use of levofloxacin in the absence of other etiologies known to cause these arrhythmias.  相似文献   
76.
In this study, a glycolipid type of biosurfactant (BS) was produced, its characteristics were evaluated and several flooding tests were conducted in a micromodel to investigate its potential for enhancing oil recovery. A rhamnolipid BS producer strain was identified as a bacterium belonging to the genus Pseudomonas aeruginosa. This BS showed good stability at temperatures of 40–121 °C, pH values of 3–10 and salinity up to 10% (w/v) NaCl which is important in Microbial Enhanced Oil Recovery (MEOR). The rhamnolipid decreased the surface tension of water from 72 to 28.1 mN m−1 with a critical micelle concentration of 120 ppm. Thin layer chromatography, FTIR spectroscopy, 1H-NMR and 13C-NMR spectroscopy revealed the glycolipid structure of the BS. Response surface methodology was applied to optimize BS production. Several micromodel flooding tests were conducted to study the capability of the produced rhamnolipid in enhanced oil recovery for the first time. An oil recovery factor of 43% was obtained at 120 ppm of BS solution whereas the recovery factor obtained for water flooding was 16%. Contact angle measurements showed that BS solutions altered the wettability of a glass surface from oil wet to a strongly water wet state. Also the results illustrated that all BS solutions were impressive in microbial enhanced oil recovery (MEOR) and using the produced BS a considerable amount of trapped oil can be extracted due to interfacial tension reduction, wettability alteration towards water wet conditions and improving the mobility ratio.

In this study, a glycolipid type of biosurfactant (BS) was produced, its characteristics were evaluated and several flooding tests were conducted in a micromodel to investigate its potential for enhancing oil recovery.  相似文献   
77.

Background

Limb loss occurs as a result of different causes and has been increasing in many countries. This study determines the demography of amputees in one of the relatively large cities of Iran.

Methods

This retrospective study was undertaken on all of the amputees between 2003 and 2011. Patients’ demographics including age, sex, the limb that had undergone amputation, etiology of limb loss and side and level of amputation were recorded. Also, the level of amputation was recorded as minor (below wrist or ankle) or major (above wrist or ankle).

Results

In total, 624 patients were enrolled in the study. The number of amputees was from 53 to 118/year. Of the patients, 508 were male (81.4?%) and 118 were female (18.6?%). The men with amputation were younger on average than women; 61.9?% of the amputations (386) were major and 38.1?% were minor (238). Overall, the most common cause of amputation was trauma and the most common level was transmetatarsal. The most common level for major amputations was below knee.

Conclusion

In contrast to similar studies in developed countries, trauma was found to be the major cause of all types of amputations and in all age groups, which emphasizes the need for preventive measures in the country.  相似文献   
78.
Background: Natural killer (NK) cells are the effector cells of innate immunity that respond to infection and tumor. Interactions between killer cell immunoglobulin like receptors (KIR) and human leukocyte antigen (HLA) class I molecules regulate NK cells responses to eliminate infected and transformed cells. Objective: To investigate the impact of KIR genes, HLA ligand genes, and KIR-HLA combinations on susceptibility to tuberculosis (TB) in Lur population of Iran. Methods: The genomic DNA of 50 patients with TB from Lorestan province of Iran was genotyped for sixteen KIR genes and their five major HLA class I ligands were determined by a polymerase chain reaction-sequence-specific primers (PCR-SSP) assay. The results were compared with those of 200 healthy unrelated Iranian individuals. Results: In Lur population of Iran, a significant decrease in frequency of KIR3DS1 was found in TB patients compared to control group (24% vs. 44.5%, OR=0.394, CI=0.194-0.798, p=0.013). Also, among the three activating genes that may use HLA class I molecules as their ligands, a significant decrease was shown in frequency of KIR3DS1 with HLA-B Bw4Ile80 ligand in TB patients compared to control group (4% vs. 23%, OR=0.14, CI=0.033-0.596, p=0.004). Conclusion: These findings imply a genetic imbalance between activating and inhibitory KIR genes and KIR-HLA combinations in Lur TB patients. Low level of activating KIR3DS1 and its combination with HLA-B Bw4Ile80 ligand might have an influence on the susceptibility to TB in Lur population of Iran.  相似文献   
79.
The pathophysiological mechanism of the serious and frequently occurring disorder delirium is poorly understood. Inflammation and sepsis are known risk factors for ICU delirium and therefore these patients are highly susceptible to delirium. Several studies have been performed to determine which cytokines are most associated with delirium but the results are inconclusive. Also, new biomarkers associated with brain dysfunction and cognitive impairment are still recognized and need to be studied to determine their relation with delirium. In this commentary we address some limitations concerning an interesting new study that warrants directions for future studies.We read with interest the study by Ritter and colleagues in which the relationship between inflammatory biomarkers and the development of delirium was investigated [1]. While delirium in critically ill patients is recognized as a major problem associated with deleterious outcome, the pathophysiology is still poorly understood. Apart from a role in further unraveling pathophysiological pathways in delirium, biomarkers could possibly also be used as diagnostic or prognostic disease markers. This task might prove to be difficult, as delirium is a multifactorial disorder and thus several pathways are probably involved in its development [2]. Studying the underlying mechanism of delirium in a relatively homogeneous study population, as Ritter and colleagues did in 78 inflamed patients [1], could minimize the interaction between different pathways. Patients with systemic inflammation or sepsis are highly vulnerable to developing brain dysfunction and delirium, also defined as sepsis-associated delirium or sepsis-associated encephalopathy [3], and could therefore serve this purpose.Ritter and colleagues studied TNFα, soluble TNF receptor (STNFR)-1, STNFR2, IL-1β, IL-6, IL-10 and adiponectin in systemic inflamed patients in relation to delirium [1]. In their prospective cohort study they found significant associations between STNFR1, STNFR2, IL-1β and adiponectin concentrations and the development of delirium.We previously found that delirium was associated with IL-8 (odds ratio, 9.0; 95% confidence interval, 1.8 to 44.0) and IL-10 (odds ratio, 2.6; 95% confidence interval, 1.1 to 5.9) but not with TNFα in inflamed ICU patients [4]. In contrast, Ritter and colleagues found no association between IL-10 and delirium. This discrepancy might be explained by differences in study design: Ritter and colleagues collected blood samples within 12 hours of ICU admission, while in our study blood was drawn within 24 hours after the onset of delirium regardless of ICU length of stay. In view of the changes over time in the concentration of cytokines and the development of delirium, serial determinations of circulating inflammatory markers and the relationship with the development of delirium would be of great interest, but this has not been carried out in ICU patients up to now.Surprisingly, Ritter and colleagues found no differences in several patient characteristics such as age, severity of illness scores, and duration of mechanical ventilation, but also not in the presence of sepsis, between delirious and nondelirious ICU patients, while these characteristics are clearly recognized as risk factors for delirium [5-7]. A possible explanation for why they did not find these differences could be the frequency of delirium assessment. Due to its fluctuating course, delirium can be missed when patients are assessed with the Confusion Assessment Method for the Intensive Care Unit only twice a day – especially when it is recognized that on average 20% of delirium is missed when using the Confusion Assessment Method for the Intensive Care Unit [8]. This fact may also explain the observed relatively low delirium incidence (39.7%) in these highly susceptible patients suffering from systemic inflammation.Another interesting and very relevant point is that Ritter and colleagues also studied, besides the common proinflammatory and anti-inflammatory cytokines, the hormone adiponectin. Adiponectin was recently determined to interact with the brain [9] and to play a role in neuroprotection and energy expenditure. Levels of adiponectin are elevated in critically ill patients [10] and even higher in delirious ICU patients, as Ritter and colleagues determined [1]. These authors are the first to determine an association between adiponectin levels (adjusted for weight) and delirium.Although not a primary study aim, Ritter and colleagues also determined the accuracy of the prediction of delirium using these biomarkers. Even though IL-β, STNFR1, STNFR2 and adiponectin individually predict delirium moderately well (area under the receiver operating characteristics curve: 0.70 to 0.84), the authors did not mention the overall area under the receiver operating characteristics curve of the model using multivariate regression analysis. Unfortunately the sample size in their study did not allow inclusion of other relevant risk factors. In daily clinical practice, therefore, using a delirium prediction model specifically developed for prediction based on clinical risk factors appears better [11]. Despite these shortcomings, their study was well designed and their findings are very relevant to further progress this field.Currently, the role of biomarkers as Ritter and colleagues determined is, although relevant, still limited for daily clinical practice. Serial measurements of inflammatory markers in ICU patients and further research into the role of adiponectin in the development of delirium warrant further investigation in future studies.  相似文献   
80.
In present study different protein measurement methods are evaluated on the allergenic extract of Chenopodium album pollen, which was previously prepared in our laboratory and applied in skin prick testing in comparison with a commercial extract. The protein content of similar amounts of these two extracts which had caused similar skin reactions were measured with different protein assays such as protein nitrogen unit, Lowry procedure, ultra-violet absorption, and base catalyzed hydrolysis and ninhydrin (B.H.N.). The latter is recommended by World Health Organization (W.H.O.) in order to determine total protein of standard allergenic extracts. Our study indicated some differences between protein amounts measured by the various procedures. According to W.H.O. reports regarding the advantages of B.H.N. assay, due to good correlation with biological activity of allergenic extracts, we also found that this method can indicate the potency of extracts much more precisely.  相似文献   
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