• <xmp id="1ykh9"><source id="1ykh9"><mark id="1ykh9"></mark></source></xmp>
      <b id="1ykh9"><small id="1ykh9"></small></b>
    1. <b id="1ykh9"></b>

      1. <button id="1ykh9"></button>
        <video id="1ykh9"></video>
      2. west china medical publishers
        Keyword
        • Title
        • Author
        • Keyword
        • Abstract
        Advance search
        Advance search

        Search

        find Keyword "spectrum" 49 results
        • Research progress on the regulatory mechanisms and influencing factors of blood-brain barrier permeability in optic neuromyelitis spectrum diseases

          Neuromyelitis spectrum disease (NMOSD) is an immune-mediated inflammatory demyelinating disease of the central nervous system. The breakdown of the blood-brain barrier (BBB), as an important link in the pathogenesis of NMOSD, has an important impact on the occurrence, development and prognosis of the disease. It is generally believed that the aquaporin 4 antibody produced in the peripheral circulation crosses the BBB cause damage to the central nervous system, and there are components involved in the destruction of BBB in the occurrence and development of NMOSD disease. At present, little is known about the molecular mechanism of BBB destruction in NMOSD lesions and there is still a lack of systematic theory. Further research and exploration of the regulatory mechanism of BBB permeability and the manifestation of barrier destruction in NMOSD diseases are of great significance for understanding the pathogenesis of NMOSD, so as to achieve early diagnosis and discover new therapeutic and preventive targets.

          Release date:2023-11-16 05:57 Export PDF Favorites Scan
        • A retrospective survey on epidemiological characteristics of emergency department patients

          ObjectiveTo investigate the epidemiological characteristics of patients in the emergency observation room of Beijing Shijitan Hospital during the last 5 years, to enhance the local and regional construction of education discipline and improve the quality of medical services.MethodsA retrospective study was carried out on selected patients admitted to the emergency observation room of the Capital Medical University Affiliated Beijing Shijitan Hospital between January 1st 2014 and December 31st 2018. Statistical analysis was performed to identify associated epidemiological features in these patients.ResultsAmong the 19 518 patients admitted to the emergency observation room, 49.08% were males and 50.92% were females, with a male to female ratio of 1:1.04. The 46-65 age group had the lowest proportion of females of 47.28%, while this proportion reached to 55.38% in the over-80 age group, which was higher than that in the 46-65 and 66-80 age groups, showing statistical significance (P<0.05). During the last 5 years, 59.66% of the patients were aged above 65; the proportion of over 65 years old patients admitted to the emergency observation room of the hospital each year was 53.86%, 53.19%, 57.00%, 65.40%, and 68.79%, respectively, showing an increasing trend (P=0.011). Among the patients diagnosed, 24.20% had respiratory system diseases, 23.67% had circulation system diseases, 14.47% had digestive system diseases, 12.75% had neurological system diseases, and 7.08% had endocrine system diseases. According to the primary diagnosis, the top 10 most predominant diseases were bacterial pneumonia (14.72%), acute and chronic heart failure (7.86%), hypertension (5.00%), arrhythmia (4.02%), coronary atherosclerotic heart disease (3.92%), chronic obstructive pulmonary disease (3.01%), cerebrovascular disease (2.68%), gastrointestinal hemorrhage (2.66%), acute diabetes (2.43%), and celiac infection (1.73%), which accounted for 48.02% of the total patients admitted. In the winters (December to February) of these 5 years, the total number of patients admitted was 6 145, which contributed to 31.48% of the total admission number, and hence making winter the season with the highest number of patients seeking for medical services.ConclusionsAccording to the spectrum of the disease features, there is a need to enhance the training of specialty and emergency clinics associated with respiratory, circulation, neurological, digestive, and endocrine diseases. Special attention should be paid for treatment and health care targeted at old-aged patients. During winter, the peak hospital visiting time, appropriate medical care service, which addresses the plan of working time, should be provided in order to optimize diagnosis and treatment processes.

          Release date:2019-12-12 04:12 Export PDF Favorites Scan
        • Gravity Frequency and Its Monitoring Application of EEG Spectrum in the Vigilance Operation

          It is an important means to study the electrical activity of the brain's nerve cells by exploring physiological information of the EEGs from the frequency domain. The gravity frequency is one of the global parameters with using this method. We used the multitaper spectrum method (MTM) spectrum estimation method of good performance to calculate the EEG spectrum and its gravity frequency of subjects under vigilance and vigilance decrement state. The results showed that the gravity frequency of vigilance state was higher than that of vigilance decrement state, the gravity frequency became smaller along with the vigilance decrement, and the location of the gravity frequency shifted to the left in the spectrum. Finally, the monitoring curve of the gravity frequency was acquired by designing an algorithm, and it was used to online monitoring vigilance operators.

          Release date: Export PDF Favorites Scan
        • An electroencephalogram-based study of resting-state spectrogram and attention in tinnitus patients

          The incidence of tinnitus is very high, which can affect the patient’s attention, emotion and sleep, and even cause serious psychological distress and suicidal tendency. Currently, there is no uniform and objective method for tinnitus detection and therapy, and the mechanism of tinnitus is still unclear. In this study, we first collected the resting state electroencephalogram (EEG) data of tinnitus patients and healthy subjects. Then the power spectrum topology diagrams were compared of in the band of δ (0.5–3 Hz), θ (4–7 Hz), α (8–13 Hz), β (14–30 Hz) and γ (31–50 Hz) to explore the central mechanism of tinnitus. A total of 16 tinnitus patients and 16 healthy subjects were recruited to participate in the experiment. The results of resting state EEG experiments found that the spectrum power value of tinnitus patients was higher than that of healthy subjects in all concerned frequency bands. The t-test results showed that the significant difference areas were mainly concentrated in the right temporal lobe of the θ and α band, and the temporal lobe, parietal lobe and forehead area of the β and γ band. In addition, we designed an attention-related task experiment to further study the relationship between tinnitus and attention. The results showed that the classification accuracy of tinnitus patients was significantly lower than that of healthy subjects, and the highest classification accuracies were 80.21% and 88.75%, respectively. The experimental results indicate that tinnitus may cause the decrease of patients’ attention.

          Release date:2021-08-16 04:59 Export PDF Favorites Scan
        • Risk Factors Analysis of Community-acquired Urinary Tract Infections Caused by Extended-spectrum β-lactamase-producing Escherichia coli

          ObjectiveTo explore the risk factors of community-acquired urinary tract infections caused by extended-spectrum β-lactamase-producing Escherichia coli (ESBLs-producing Escherichia coli). MethodsProspective and retrospective investigation methods were combined, to investigate the hospitalized patients diagnosed with community-acquired urinary tract infections caused by ESBLs-producing Escherichia coli in the Second Affiliated Hospital of Fujian Medical University during July 2012 to December 2014. Statistical analysis was performed using SPSS 19.0 software. The potential risk factors were analyzed by chi-square test or Fisher exact probability method, then, factors with statistical significance identified by single factor analysis were further analyzed by non-conditional logistic regression. ResultsA total of 106 patients were included and divided into a ESBLs group (68 cases) and a control group (38 cases) according to the drug sensitivity test results. The results of single factor analysis indicated: there were significant differences between the ESBLs group and the control group in the use of antibiotics within three months before admission (χ2=11.292, P=0.001), the use of third generation cephalosporin (χ2=11.033, P=0.001), more than three kinds of diseases that could cause urinary tract obstruction (χ2=16.464, P=0.000), anemia (χ2=5.956, P=0.015), indwelling catheter (χ2=6.695, P=0.010), urinary system operations (χ2=9.730, P=0.002). The results of further non-conditional logistic regression analysis showed that more than three kinds of diseases that could cause urinary tract obstruction (OR=14.675, 95%CI 2.699 to 79.796, P=0.002), anemia (OR=7.976, 95%CI 1.785 to 35.632, P=0.007), the use of antibiotics within three months before admission (OR=7.057, 95%CI 1.597 to 31.175, P=0.010), the use of third generation cephalosporin (OR=6.344, 95%CI 1.145 to 35.146, P=0.034) and indwelling catheter (OR=3.844, 95%CI 1.058 to 13.967, P=0.041) were independent risk factors of community-acquired urinary tract infections caused by ESBLs-producing Escherichia coli. ConclusionThe risk factors of community-acquired urinary tract infections caused by ESBLs-producing Escherichia coli include more than three kinds of diseases that could cause urinary tract obstruction, anemia, the use of antibiotics within three months before admission, the use of third generation cephalosporin, and indwelling catheter. The use of antibiotics, especially the third generation cephalosporin, should be strictly controlled, the time of indwelling catheter should be reduced, and the anemia should be corrected, in order to reduce the incidence of community-acquired urinary tract infections caused by ESBLsproducing Escherichia coli.

          Release date: Export PDF Favorites Scan
        • Association between folic acid supplementation during pregnancy and the risk of autism spectrum disorder in the offspring: a meta-analysis

          ObjectiveTo systematically review the association between maternal folate supplementation during pregnancy and the risk of autism spectrum disorder (ASD) in the offspring.MethodsPubMed, EMbase, Web of Science, The Cochrane Library, Scopus, CNKI, WanFang Data, VIP and CBM databases were electronically searched to collect case-control and cohort studies on the association between maternal folate supplementation during pregnancy and the risk of ASD in the offspring from inception to December 2020. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Meta-analysis was then performed using RevMan 5.3 and Stata 14.0 software.ResultsA total of 17 studies involving 10 812 cases and 876 241 controls were included. The results of meta-analysis showed that there was no significant association between maternal folate supplementation during pregnancy and the risk of ASD in the offspring in the total population. The subgroup analysis revealed that maternal folate supplementation during pregnancy was statistically associated with a reduced risk of ASD in the offspring in the Asian population (OR=0.71, 95%CI 0.53 to 0.96, P=0.03). However, there were no statistical correlations in European and American populations.ConclusionsCurrent evidence shows that maternal folate supplementation during pregnancy may reduce the risk of ASD in the offspring in the Asian population. Due to limited quality and quantity of the included studies, more high-quality studies are required to verify the above conclusions.

          Release date:2021-11-25 02:48 Export PDF Favorites Scan
        • Research Progress of Electrical Impedance Spectrum Technology in The Diagnosis of Thyroid Carcinoma

          Objective To summarize the basic principle of electrical impedance spectrum technology and the latest progress in the diagnosis of thyroid carcinoma. Methods By the domestic and overseas literatures review, medical application and diagnostic prospect in thyroid carcinoma of electrical impedance spectrum were summarized. Results Electrical impedance spectrum was a kind of somatic function imaging, whose measurement results was objective, and it could diagnose thyroid carcinoma in early stage effectively. In addition, it could be used as a complementary form of fine needle aspiration biopsy, improving the diagnostic accuracy rate of thyroid carcinoma, thereby reducing the unessential thyroid operations. Conclusion Electrical impedance spectrum technology is a potentially useful imaging modality for diagnosing thyroid carcinoma in early stage, and functions as a auxiliary clinical diagnosis method for fine needle aspiration biopsy.

          Release date:2016-09-08 10:35 Export PDF Favorites Scan
        • INFLUENCE OF IMMERSED TIME BY HYDROGEN DIOXIDE ON XENOGENEIC BONE SUBSTITUTE

          Objective To study the influence of the immersed time by hydrogen dioxide on the characteristics of bovine cancellous bone granules in various periods. Methods Ten 24-month-old Qinchuan bovine, male or female, weighing 150-170 g, were selected. Cancellous bone granules from metaphysic of bovine long bone were cut into cubes of 5 mm × 5 mm ×5 mm and immersed by 8.8 mol/L hydrogen dioxide for 0, 12, 24, 36, 48, 60 and 72 hours separately. Determination of ash, scanning electron microscope, X-ray energy spectrum and micro CT were used to investigate the changes of composition, structure and qual ity of bone. Results With the immersed time increasing, the contents of organics in the bone cancellous were reduced gradually, and obviously decreased during the periods of 0 to 24 hours and 60 to 72 hours (P lt; 0.05). The contents of calcium and phosphorus decreased gradually, they could not be detected almost after 60 days (P lt; 0.05). Bone mineral density and bone mineral content were decreased obviously after 60 hours (P lt; 0.05). The bone trabecula became sl immer and trabecular spacing became larger. Conclusion Hydrogen dioxide can be used to remove the antigen in xenogeneic bone; however as the time increasing (more than 60 hours) the composition and structure will be damaged. Thus it is important to control the immersed time for maintaining the biological characteristics of xenogeneic bone substitute as well as el iminating antigen by hydrogen dioxide.

          Release date:2016-09-01 09:06 Export PDF Favorites Scan
        • Diagnostic accuracy of MRI in the diagnosis of preschool children with autism spectrum disorder: a meta-analysis

          ObjectiveTo systematically review the diagnostic accuracy of MRI in preschool children with autism spectrum disorder. MethodsDatabases including Web of Science, PubMed, The Cochrane Library, EMbase, CBM, CNKI, WanFang Data, and VIP were electronically searched for studies on MRI in diagnosis of preschool children with autism spectrum disorder from inception to January 2022. Two reviewers independently screened the literature, extracted data, and assessed the risk of bias the included studies. Then, meta-analysis was performed using Meta-Disc, RevMan 5.4 and Stata 16.0 software. ResultsA total of 17 studies were finally included. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnosis odds ratio and area under the curve of SROC were 0.78 (95%CI 0.76 to 0.81), 0.77 (95%CI 0.75 to 0.79), 3.92 (95%CI 2.83 to 5.41), 0.28 (95%CI 0.23 to 0.35), 14.8 (95%CI 9.31 to 23.52) and 0.86, respectively. Subgroup analysis revealed that the source of patients, age, prediction methods and analysis features were potential sources of heterogeneity. Heterogeneity in the subgroup of 1-3 years old was small, and the pooled sensitivity, specificity and area under the curve of SROC were 0.81 (95%CI 0.76 to 0.85), 0.82 (95%CI 0.78 to 0.86) and 0.87, respectively. The pooled sensitivity, specificity and area under the curve of SROC for non-site studies were 0.80 (95%CI 0.75 to 0.84), 0.80 (95%CI 0.76 to 0.85) and 0.86, respectively. ConclusionMRI has a high accuracy in the diagnosis of preschool children with autism spectrum disorder; however, the possibility of misdiagnosis and missed diagnosis should be considered. Due to the limited quantity and quality of the included studies, more high-quality studies are needed to verify the above conclusion.

          Release date:2022-04-28 09:46 Export PDF Favorites Scan
        • A multifrequency time-difference electrical impedance tomography algorithm using spectral constraints

          This study aims to propose a multifrequency time-difference algorithm using spectral constraints. Based on the knowledge of tissue spectrum in the imaging domain, the fraction model was used in conjunction with the finite element method (FEM) to approximate a conductivity distribution. Then a frequency independent parameter (volume or area fraction change) was reconstructed which made it possible to simultaneously employ multifrequency time-difference boundary voltage data and then reduce the degrees of freedom of the reconstruction problem. Furthermore, this will alleviate the illness of the EIT inverse problem and lead to a better reconstruction result. The numerical validation results suggested that the proposed time-difference fraction reconstruction algorithm behaved better than traditional damped least squares algorithm (DLS) especially in the noise suppression capability. Moreover, under the condition of low signal-to-noise ratio, the proposed algorithm had a more obvious advantage in reconstructions of targets shape and position. This algorithm provides an efficient way to simultaneously utilize multifrequency measurement data for time-difference EIT, and leads to a more accurate reconstruction result. It may show us a new direction for the development of time-difference EIT algorithms in the case that the tissue spectrums are known.

          Release date:2020-04-18 10:01 Export PDF Favorites Scan
        5 pages Previous 1 2 3 4 5 Next

        Format

        Content

      3. <xmp id="1ykh9"><source id="1ykh9"><mark id="1ykh9"></mark></source></xmp>
          <b id="1ykh9"><small id="1ykh9"></small></b>
        1. <b id="1ykh9"></b>

          1. <button id="1ykh9"></button>
            <video id="1ykh9"></video>
          2. 射丝袜