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Vinegar is a kind of traditional fermented food, there are significant variances in quality and flavor due to differences in raw ingredients and processes. The quality assessment and flavor characteristics of 69 vinegar samples with 5 brewing processes were analyzed by physicochemical parameters combined with flash gas chromatography (GC) e-nose. The evaluation system of quality and the detection method of flavor profile were established. 17 volatile flavor compounds and potential flavor differential compounds of each brewing process were identified. The artificial neural network (ANN) analysis model was established based on the physicochemical parameters and the analysis of flash GC e-nose. Although the physicochemical parameters were more intuitive in quality evaluating, the flash GC e-nose could better reflect the flavor characteristics of vinegar samples and had better fitting, prediction and discrimination ability, the correct rates of training and prediction of flash GC e-nose trained ANN model were 98.6% and 96.7%, respectively.

Purpose: A comprehensive population-based study on risk and prognostic factors of lung cancer with brain metastasis is lacking. Methods: 95191 patients diagnosed with lung cancer between 2010 and 2017 were collected from the Surveillance, Epidemiology and End Results (SEER) database. Patients were stratified by different variables. Multivariable logistic and Cox regression were applied to analyze the risk and prognostic factors of brain metastasis among lung cancer patients, respectively. The Fine and Gray’s competing risk regression model was performed to obtain prognostic factors associated with cancer-specific mortality.Results: Among the 95191 patients diagnosed with lung cancer, 10765 patients have brain metastasis, with a metastatic incidence of 11.31%. The primary site of tumor, residence type, age, histological type, race and extracranial metastasis were all independent risk factors of brain metastasis. Compared with other histological types, small cell lung cancer displayed a highest incidence of brain metastasis (16.62%). The median overall survival (OS) among lung cancer patients with brain metastasis was only 6.05 months. The primary site of tumor, median household income, age, histological type, race, gender and extracranial metastasis were all associated with the prognosis of brain metastasis. Patients with squamous cell carcinoma had the worst prognosis, the median OS was only 3.68 months. And our established new nomogram showed a good discriminative ability on predicting the probability of cancer-specific survival among patients with brain metastasis, the C-index was 0.61.Conclusion: Our study provided a deeper insight into the risk factors and prognosis of brain metastasis among lung cancer patients.

Background Tibet is an autonomous region in China located around an average altitude of 4500 m above sea level. Since 2012 the local government of Tibet has been providing free physical examinations, including screening for hypertension. However, the coverage and effectiveness of this free program have not been uncovered. This study aims to assess the coverage and effectiveness of hypertension screening and management program in 3 altitude levels of Tibet, and also the determinants of the success of the screening program. Methods A stratified cluster survey was conducted among 1636 residents aged 18 years or over in three different altitude areas in Tibet. We adjusted for age and sex based on national census data and used weighted logistic regression models to find factors associated with hypertension screening. Results The coverage of the hypertension screening program evaluated by participation rate in the previous screening was 94.9%, while 24.7% (95% CI: 22.1–27.3%) of them were diagnosed with hypertension. Females and alcohol drinkers were more likely to be screened. Among those diagnosed with hypertension, 28.7% had it under control. High altitude areas had a high proportion of controlled hypertension. The overall rate of controlled hypertension in high, moderate and low altitude areas was 35.1% (95% CI: 24.8–45.3%), 32.7% (95% CI: 22.2–43.2%) and 23.7% (95% CI: 14.7–32.6%), respectively. Younger aged persons were more likely to have better control of their hypertension. Conclusions The coverage of hypertension screening in Tibet was high, especially in the low altitude areas. However, the effectiveness of hypertension control was low, indicating a need to implement the treatment adherence routines into the current screening interventions.

Objective This study aimed to assess the prevalence of hypertension (HT) among individuals living at different altitudes in Tibet. Methods We conducted a stratified cluster survey among 1,631 participants in Tibet living in areas at three different altitudes. Results Mean systolic and diastolic blood pressure and body mass index (BMI) values were highest at the lowest altitudes. After adjusting for age and sex, the prevalence of HT at low, medium, and high altitudes was 40.6%, 32.5%, and 20.4%, respectively. The prevalence of HT decreased with increasing altitude and increased with increasing age and BMI value. Conclusion Increasing altitude tended to decrease BMI levels, and as a consequence, the prevalence of HT was reduced. National policies and guidelines for HT in Tibet should focus on this relationship.

Schisandra chinensis (SC) is a well-known important traditional Chinese medicine (TCM) that has been used to treat liver disease in China for a long time. However, its overall effects and mechanism of action are unclear. The present study aimed to explore the potential mechanism of SC in protection against alcoholic liver injury (ALI). In this research, to enable a full assessment of metabolic changes in ALI in Sprague-Dawley rats and to increase our understanding of physiological changes in normal and pathological states, ultra-high performance liquid chromatography combined with quadrupole time of flight mass spectrometry (UHPLC-Q/TOF-MS) was used to probe potential biomarkers to learn more about ALI and to evaluate the overall effect of SC for ALI in rats. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to investigate global metabolomic alterations and to evaluate the therapeutic effects of SC in rats. The component–target–pathway network of SC was then constructed on the basis of the network pharmacology, and the liver injury-relevant signaling pathways were thus dissected and validated. The results showed that SC has conspicuous therapeutic efficacy for ALI, as suggested by the results of the pathological section and biochemical index assays, such as those for Alanine aminotransferase (ALT), Aspartate transaminase (AST), Alkaline phosphatase (AKP), γ-glutamyl transferase (γ-GT/GGT), Reactive oxygen species (ROS), and Malondialdehyde (MDA). Furthermore, 21 kinds of potential biomarkers were identified in plasma samples of ALI rats, and 20 kinds of potential biomarkers were identified in their bile samples. The biomarkers were mainly related to inflammation and dysfunctions of amino acids and energy metabolism. The recovery of these dysfunctions partly led to the curative effect of SC on ALI.

Ethnopharmacological relevance Curcuma wenyujin Y.H. (CW), a variety of Curumae Rhizoma, which documented in China Pharmacopeia, has long been used as plant medicine for its traditional effect on promoting Qi, activating blood stagnation and expelling blood stasis. Nowadays, it is often used in clinic for extraordinary effect on liver diseases. It is worthy to be noted that CW processed with vinegar has been applied in clinic for 1500 years which started in the northern and southern dynasties. Aim of study Liver fibrosis is a worldwide clinical issue. It is worth developing a multi-target and multicellular approach which is high efficiency and low side effects for the treatment of hepatic fibrosis. The anti-hepatic fibrosis molecular mechanisms of CW and vinegar Curcuma wenyujin (VCW) need to be explored and elucidated. Furthermore, the study aimed to discuss the efficiency and mechanism differences between CW and VCW in hepatic fibrosis. Methods and results Biochemical assays and histopathology were adopted to evaluate the anti-hepatic fibrosis effect of CW and VCW. The TGF-β/Smad signaling involving TGF-β1, TGF-βRⅠ, TGF-βRⅡ and Smad2, Smad3, Smad7 in fibrosis is examined, which is a critical step towards the evaluation of anti-hepatic fibrosis agents. Meanwhile, the MMP/TIMP balance is a potential therapy target by modulating extracellular matrix, which is also examined. Both CW and VCW inhibit the activation and proliferation of hepatic stellate cells and induce apoptosis via blocking TGF-β/Smad signaling pathways. Additionally, the level of MMP-2/TIMP-1 regulated significantly, which suggest CW and VCW participate in the degradation process, and maintain the formation and production of extracellular matrix. Conclusion Raw and vinegar processed Curcuma wenyujin regulates hepatic fibrosis via bloking TGF-β/Smad signaling pathways and up-regulation of MMP-2/TIMP-1 ratio. And VCW has more exhibition than CW.

Objective To investigate the influence of acupuncture at ST36 on the pharmacokinetics of Schisandra lignans including schisandrin, deoxyschisandrin and schisandrin B after intragastric administration of Schisandra chinensis (SC) in rats. Methods Twelve male Sprague-Dawley rats were randomly divided into two study groups: SC and SC+acupuncture. Rats in both groups received intragastric SC extract at 5.0 g/kg. Rats in the SC+acupuncture group additionally received acupuncture stimulation at ST36 for 30 min after SC administration. Acupuncture needles were rotated bilaterally for 1 min, left in situ for 20 min, then electrically stimulated for 10 min at 50 Hz frequency and 1–3 mA intensity. A sensitive and specific high performance liquid chromatography electrospray tandem mass spectrometry procedure was developed and validated for simultaneous analysis of three bioactive lignans (schisandrin, deoxyschisandrin and schisandrin B) in rat plasma. Results There were significant differences (p0–t), area under the plasma concentration–time curve to time infinity (AUC0–∞) and peak plasma concentration (Cmax) for schisandrin, absorption half-life (T1/2α) and AUC0–t for deoxyschisandrin, and Cmax for schisandrin B were increased in the SC+acupuncture group compared with the SC group. T1/2α for schisandrin B only and time to peak concentration (Tmax) for all three lignans were reduced following acupuncture. Conclusions Acupuncture stimulation at ST36 affects the pharmacokinetics of SC in rats. Acupuncture may have a beneficial role in promoting the absorption of lignans from extracts of SC.

Experiments from three-phase (natural gas+water+diesel oil) flow systems were performed in a flowloop to study the hydrate formation and plugging mechanisms from data on morphology and flow characteristics. The hydrate plugging mechanism was investigated for a range of water cuts (5–80 vol%) and the injection of chemical additives (glycol and Inhibex 501). The results from the flowloop experiments demonstrated that water and oil formed a disperse system in which water formed a three-dimensional network, separating oil into a mass of oil droplets before hydrate formation; when hydrate began to form, the water network converted into a hydrate network and formed a very sticky oil-in-hydrate network system; With the hydrate formation, some of the oil was squeezed out of the network and the oil-in-hydrate network system shrank, precipitated from the oil phase, and deposited onto the pipe wall, and finally formed hydrate plugging. The presence of glycol or Inhibex 501 did not change the formation mechanism of hydrate plugging, while it decreased the hydrate formation rate.

Foi realizado um levantamento em 12 municípios da região central de Rondônia sobre a presença de plantas tóxicas e ocorrência de surtos de intoxicação em ruminantes e equídeos. O trabalho foi desenvolvido mediante a utilização de um questionário aplicado a médicos veterinários, agrônomos, zootecnistas e produtores rurais, com o objetivo de identificar as principais plantas tóxicas que ocorrem na região. Trinta e quatro entrevistados relataram casos de intoxicação por uma ou mais plantas comprovadamente tóxicas como: Palicourea marcgravii (12 surtos), Palicourea grandiflora e Enterolobium contortisiliquum (sete surtos cada) e Palicourea juruana, Brachiaria radicans, Brachiaria brizantha e Manihot esculenta (dois surtos cada). Em ovinos, foram relatados dois surtos de fotossensiblização por Brachiaria decumbens e um surto de mortalidade por Palicourea grandiflora. Dos 34 surtos relatados em bovinos pelos entrevistados, 374 (8,9%) animais foram afetados e 311 (7,4%) morreram, de um total de 4.192 de ambos os sexos sob risco. De um total de 250 ovinos sob risco, três surtos de intoxicação por plantas foram relatados e afetaram 28 animais, dos quais 20 morreram. Amorimia sp., previamente desconhecida como tóxica, foi identificada como causa de morte súbita em 32% das propriedades. Quinze surtos de cólica em equídeos que pastavam cultivares de Panicum maximum ('Massai', 'Tanzânia' e 'Mombaça') durante o período das chuvas foram, também, observados. Os resultados do presente trabalho demonstram a importância significativa das intoxicações por plantas como causa de perdas econômicas para a pecuária da região central do Estado de Rondônia. Com a realização deste trabalho, o número de plantas tóxicas para ruminantes com a confirmação de ocorrência de surtos com mortalidade na região passou de um para nove, o que confirma que um trabalho sistemático de investigação é necessário para o conhecimento da importância das intoxicações por plantas na região Norte do Brasil.

The objective is to determine the timing and indications of transcatheter angiographic embolization (TAE) for delayed haemorrhage after percutaneous nephrolithotomy (PCNL). The medical records of 144 patients who underwent arteriography and TAE for delayed post-PCNL haemorrhage at five university hospitals between January 2005 and December 2012 were reviewed retrospectively. The mean time to the onset of post-PCNL haemorrhage was 10.5 days (2 - 30 days). Clinical presentation included sudden onset bleeding in 51 patients (35.4 %), intermittent bleeding in 67 patients (46. 5 %), and continuous slow bleeding in 26 patients (18.1 %). Hemodynamic instability occurred in 32 patients (22.2 %). The mean haemoglobin decrease from the first post-PCNL day to the day of TAE was 49.5 g/L (31.0 - 79.0 g/L). Renal arteriography showed pseudoaneurysms in 69 (47.9 %) patients, arteriovenous fistulas in 28 (19.4 %) patients, mixed arterial and arteriovenous lesions in 17 (11.8 %) patients, arterial lacerations in 23 (16.0 %) patients, and negative angiographic finding in seven (4.9 %) patients. TAE was successful in stopping bleeding in all 137 patients with vascular lesions. There were no major complications associated with TAE. TAE should be the recommended treatment for delayed post-PCNL haemorrhage in patients with hemodynamic instability and/or corrected haemoglobin decrease >30 g/L following conservative management. • Delayed haemorrhage after percutaneous nephrolithotomy occurs more than 24 hours postoperatively. • Angio-embolization is a safe and effective treatment for delayed post-PCNL haemorrhage. • Angio-embolization can treat hemodynamic instability and/or corrected haemoglobin decrease >30 g/L.

Based on the basic principles of anti-islanding detection, this paper puts forward an anti-islanding (AI) detection method which combined/q-axis voltage decoupling and positive feedback with Euler-Lagrange (EL) model .The proposed method is classified as an passive islanding detection method and it is based on the voltage change at the point of common coupling (PCC) that occurs in islanding .In the method, Add the d-axis decoupling voltage of PCC to the d-axis reference current of the EL model. A simulation study shows that the method is simple and feasible.

To avoid local convergence and slow convergence of GA, SVM was used to get the fitness function in this paper and Statistical Learning Theory was used to guide the optimization process. Then, the improved GA was applied to Optimizing Cigarette Logistic Distribution Routing Problem, and the result proved that the algorithm was efficient in convergence.

The volumetric properties of two reservoir fluid samples collected from one condensate gas well and one natural gas well were measured under four groups of temperatures, respectively, with pressure up to 116 MPa. For the two samples examined, the experimental results show that the gas compressibility factor increases with the increase of pressure. But the influence of the temperature is related to the range of the experimental pressure. It approximately decreases with the increase of temperature when the pressure is larger than (45 to 50) MPa, while there is the opposite trend when the pressure is lower than (45 to 50) MPa. The dew point pressure was also determined for the condensate gas sample, which decreases with the increase of temperature. The capabilities of four empirical correlations and a thermodynamic model based on equation of state for describing gas compressibility factor of reservoir fluids under high pressure were investigated. The comparison results show that the thermodynamic model recommended is the most suitable for fluids whatever produced from high-pressure reservoirs or conventional mild-pressure reservoirs.

For the problem of manual manipulation and data asynchronous acquisition, the opinion of digital test was introduced. Based on the existing equipment, control and test method, the overall design of test platform was put forward. In the following, the data sharing, the software control system, dynamometer system, lube oil control system and cooling water control system were designed respectively. In the end, the digital test platform was developed. Under the new test platform, the test conditions can be adjusted automatically, the measurement device can be remote-controlled, the test data can be collected and recorded in synchronization and the test results can be sent to the designers in time.

For getting the effectiveof application in dissipation dust law with particle motion equation atcoal handling system of belt machine tail, must be to proceed related numerical simulation in the way of dust particles motion incoal handling system of belt machine tail and dust concentration of diffusion inoperation space. Application particlemotion equation theory for numerical simulation to coal dustparticles, obtained dust coal dissipation law in coal handling system, at thesame time combine with the data of the field test of dust concentration andfallout dispersion for analyzing and comparing. The results of comparison showthat: the data of numerical simulation with particle motion equationin coal dust dissipation law is coincide with reality dissipation law. Accordingto the conclusion of this research, it is provides theoretical basis forprevention and treatment in coal mine of coal handling system of dustdissipation.

Sulfur fumigation method is often used in the habitat processing of Astragali Radix in order to make it mothproof, mildewproof and easy to dry; however, this method has great influence on the inherent quality of Astragali Radix. Therefore, it is urgent to develop the alternative technology to sulfur fumigation. In the present paper, appearance characteristics, content of active ingredients, containing water, extracting content and microbial content in Astragali Radix were taken as the indexes to compare the quality of Astragali Radix processed with 9 kinds of processing methods (traditional processing method, sulfur fumigation and 7 kinds of alternative processing technologies). Combined hot air-microwave technology was finally determined as an alternative technology to sulfur fumigation.

It concerns about issues of dust pollution of three feeder which in the underground passage under the storage warehouse of Inner Mongolia Datang International Xilinhaotes Mining Company Limited.By inspections and investigations in the field,according to site-specific circumstances and local climatic conditions,we had implemented comprehensive renovation project of coal dust of feeder in underground passage,and achieved remarkable and effective governance results.

There is serious inter-symbol interference (ISI) when ultra-wideband (UWB) wireless communication systems work at high data speed since there is much larger channel delay spread. The serious ISI becomes a major factor that affects the performance of UWB systems. In this paper, suppression ISI is developed for direct sequence spread-code division multiple access (DS-CDMA) UWB systems with a high data speed, and a joint chip equalization adaptive Rake (JCE-Rake) receiver is proposed. The proposed JCE-Rake receiver spreads the number of traditional Rake receiver taps to collect multi-path component and equalize the inter-chip interference simultaneously. Then the soft output of JCE-Rake receiver is despreaded with the user's spreading code. Finally the decision is made to recover the transmitted symbol. The simulation results verify that ISI is suppressed effectively and the system performance is improved evidently.

In order to solve the problem of crack appeared in Francis turbine runner, the welding residual stress of Francis turbine runner is regulated and controlled by means of numerical simulation from the view of subsection welding, local heating and local peening. The results show that the length of welding section of blade outlet and the welding direction in the subsection welding process influence the residual stress of the turbine blade. For the local heating technology, the decreasing effect on residual stress increases with the increase of heating time, heating temperature and heating area. The welding residual stress of dangerous region decreases and then increases with the increase of heating distance. Moreover, the peening effect is very clear when the temperature of material in the peening region reaches its own plastic temperature.

In order to generate STEP-NC data model in keeping with the ISO14649 protocol, extend the STEP model to the field of the CNC, the paper analyzes STEP standard and its file structure, develops the display software which can be read and display the STEP format file based on open source Open CASCADE geometric kernel by using the Visual Studio 2008 software development environment, designs one instance by using Pro/E software, and stored as a STEP format file in Pro/E environment, and then, using the software developed to read and display the STEP file. The results of this study improve the product data exchange and integration capabilities, lay a good foundation for generating the STEP-NC format file in the future, extracting the file STEP-NC machining information, and achieving CAD / CAM / CAPP integration system.

Based on diesel engine, the digital collaborative platform was designed. The key technology of supporting the platform was introduced. In addition, the principle of digital collaborative design was designed. For a diesel engine, the flow of design was introduced. In every step, the designed contents were determined. Compared the traditional design, the new design will have the shorter period and the better design quality.

Temperature plot is crucially important for numerical simulation of high waxy crude pipeline because of its non-Newtonian behavior at low temperature. As the fluid temperature drops below than the wax appearance temperature, the viscosity of the crude increases dramatically. Thus the needed pressure has a possibility to reach the maximum allowable pressure and cause a potential risk for the pipeline itself. To avoid this, numerical simulation of the temperature plot along the pipeline is necessary in order to obtain accurate information. However, as the temperature governing equation is a non-linear equation and the soil temperature field is also being involved. It is required to solve the surrounded soil temperature field. In the paper, the governing equation for one dimensional crude pipeline and the new moisture-heat equation for the soil (porous medium) are presented and the iteration algorithm to solve this coupled equation is given. With the algorithm and the coupled heat-moisture equations, the numerical results are obtained and have a very precise coincidence with the experimental results. Then a reliability based method is used to evaluate the flow safety of one pipeline in China. With the presented model and obtained results, the flow safety evaluation results show that the safety of the crude pipeline is assured in the test cases.

The aim of this paper is mainly to study the main coal-dust pollution sources in the coal preparation plants of Ping Shuo Branch of China National Coal Group. Through the combination of many measurement data with numerical simulation of gas-solid two-phase flow, dust precipitation mechanisms have been gained for the feeder in Ping Shuo Coal Preparation Plant. Dust pollution of the feeder is caused by the positive pressure of the induced feeding wind-flow and the bad seal itself. Firstly, the durable flexible seal material is used to seal up the feeder. Secondly, the seal guide-chute with the dust collector is installed on the belt. Finally, the air volume and the pressure of the dust collector are determined by means of numerical simulation, and the reasonability of the plan is explained from the angle of the dust control mechanism. The main technical parameters of the dust control plan, such as the seal guide-chute length, and the air volume and the pressure of the dust collector, are determined through the numerical simulation. The simulation result and the actual result verify the above dust control plans. The study methods and results provide a guide for the dust control in a certain similar business.

In view of the spiral bevel gear machined by the semi-generating means, a new method to create 3D solid model is proposed. The equation of tooth profile surface is deduced from the principles of spiral bevel gear engagement and cutting, according to the position relationship of the machine tool, the cutting tool and the workpiece, along with the cutting tooth process. Then the three-dimensional solid model of spiral bevel gear is developed with the delphi program using the known parameters and the above mathematic equations. The effectiveness of this method has been demonstrated.

An improved method based on pseudostatic and limit-equilibrium analysis is proposed for evaluating seismic (static plus dynamic) active earth pressures induced by backfill behind movable rigid retaining walls. The proposed method can take into account the effects of strain localization and postpeak shear resistance reduction in the dense backfill soil during a strong earthquake, and the main improvement over the existing method is that a simple analytical solution is provided.

Summary Aims We investigated the usefulness of diffusion tensor tractography (DTT) for differentiating between histological pathologies and evaluating white matter (WM) damage resulting from brain tumors. We also sought to categorize the appearance of brain tumor–related WM tract changes. Methods A total of 18 inpatients with intracranial neoplasms were enrolled. MRI examinations were performed at 3 T using an 8-channel phased array coil. DTT was reconstruction from the raw data of diffusion tensor imaging. WM tract–based analysis of the mean diffusivity (MD), eigenvalues (λ1, λ2, λ3), and fractional anisotropy (FA) was performed by the manual placement of regions of interest (ROIs) on the color-coded FA maps using DTIStudio software. The axial diffusivity (DA, namely λ1) and the tensor shape (Cl, namely (λ1 − λ2)/3 (λ)) were also compared between groups. P values

High-resolution and high-sensitivity instrumentation has been designed and assembled for the study of vibrationally- and rotationally-resolved luminescence from products of core-hole decay in molecules. The luminescence is produced by the interaction of a high-density molecular beam with either high-energy electrons or with monochromatic synchrotron radiation and is detected by a large-aperture 1-m spectrograph equipped with an intensified photodiode array.

This paper presents a Digital to Analog Converter (DAC) suitable for video applications. This DAC can generally simplify conventional DAC circuits. The 8-bit DAC only requires twelve switches and twelve resistors to achieve the goal of high speed and low power applications. This DAC is implemented by TSMC 0.18 mum process technology. The simulation results of our work with integral non-linearity (INL) and differential non-linearity (DNL) is less than 1.57 LSB and 0.12 LSB, respectively. The average power consumption is only 1.10 mW/MHz.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:58:51Z No. of bitstreams: 1 S0103-51502010000400008.pdf: 905264 bytes, checksum: f4d17ad8bf3b0df9517d41c373369ab6 (MD5) Made available in DSpace on 2013-08-22T18:58:51Z (GMT). No. of bitstreams: 1 S0103-51502010000400008.pdf: 905264 bytes, checksum: f4d17ad8bf3b0df9517d41c373369ab6 (MD5) Previous issue date: 2010-12-01 Made available in DSpace on 2013-09-30T19:54:58Z (GMT). No. of bitstreams: 2 S0103-51502010000400008.pdf: 905264 bytes, checksum: f4d17ad8bf3b0df9517d41c373369ab6 (MD5) S0103-51502010000400008.pdf.txt: 27516 bytes, checksum: 22cda97fc21a0ca6e59904e10adda442 (MD5) Previous issue date: 2010-12-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:58:01Z No. of bitstreams: 2 S0103-51502010000400008.pdf: 905264 bytes, checksum: f4d17ad8bf3b0df9517d41c373369ab6 (MD5) S0103-51502010000400008.pdf.txt: 27516 bytes, checksum: 22cda97fc21a0ca6e59904e10adda442 (MD5) Made available in DSpace on 2014-05-20T13:58:01Z (GMT). No. of bitstreams: 2 S0103-51502010000400008.pdf: 905264 bytes, checksum: f4d17ad8bf3b0df9517d41c373369ab6 (MD5) S0103-51502010000400008.pdf.txt: 27516 bytes, checksum: 22cda97fc21a0ca6e59904e10adda442 (MD5) Previous issue date: 2010-12-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação para o Desenvolvimento da UNESP (FUNDUNESP) INTRODUÇÃO: A fadigabilidade excessiva dos músculos lombares é um achado comum em pacientes portadores de dor lombar. Por isso, a avaliação da resistência isométrica desses músculos tem sido recomendada nessa população. OBJETIVO: O objetivo deste estudo foi identificar e analisar objetivamente o comportamento da fadiga do músculo eretor da espinha em um teste de resistência isométrica realizado até a exaustão. METODOLOGIA: Nove sujeitos saudáveis realizaram o teste de Sorensen modificado com contrações em intensidades correspondentes a 5%, 10%, 15% e 20% da contração voluntária máxima. A fadiga muscular foi identificada pela análise do comportamento da frequência mediana (FM) em função do tempo. RESULTADOS: O tempo de resistência isométrica foi inversamente correlacionado com a intensidade da contração. Contudo, a intensidade da contração não demonstrou efeito sobre a taxa de declínio da FM. A fadiga muscular foi significante em todas as porções do músculo eretor da espinha. Comparações entre os músculos eretor da espinha direito e esquerdo não revelaram diferenças significantes, enquanto que comparações entre porções do músculo eretor da espinha localizadas em diferentes níveis lombares revelaram maiores níveis de fadiga em L4-L5 bilateralmente. CONCLUSÃO: A análise espectral do sinal eletromiográfico foi eficaz para idenficação da fadiga do músculo eretor da espinha. Também foi possível identificar diferenças funcionais entre as diferentes porções desse músculo. O conhecimento dessas particularidades permite intervir de forma mais específica na prevenção e reabilitação dos distúrbios da coluna lombar. INTRODUCTION: Excessive fatigability of the low back muscles is a common finding in low back pain patients. Therefore, the assessment of the isometric endurance of these muscles has been recommended in this population. OBJECTIVE: The purpose of this study was to identify and to analyze objectively the behavior of the erector spinae muscle fatigue in an isometric endurance test performed until exhaustion. METHOD: Nine healthy subjects performed a modified Sorensen test with contractions of 5%, 10%, 15%, and 20% of the maximal voluntary contraction. The muscle fatigue was identified for the analysis of the behavior of the median frequency (MF) over time. The endurance time was inversely correlated with the contraction intensity. However, the contraction intensity did not show effect on the rate of decline of the MF. The muscle fatigue was significant in all the portions of the erector spinae muscle. RESULTS: Comparisons between the erector spinae muscles from right and left side did not show significant differences, while that the comparisons between the portions of the erector spinae muscle localized at different vertebral levels showed higher fatigue levels at L4-L5 bilaterally. CONCLUSION: Thus, the spectral analysis of the electromyographic signal was effective for the identification of the erector spinae muscle fatigue. Also, it was possible to identify functional differences between the different portions of this muscle. The knowledge of these particularities allows managing in a more specific way the prevention e rehabilitation of the low back troubles. Universidade Federal de Rondônia Departamento de Ciências da Educação Centro Universitário Luterano de Ji-Paraná Departamento de Fisioterapia Universidade Estadual Paulista Departamento de Educação Física Universidade Estadual Paulista Departamento de Educação Física