• <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 "stress" 280 results
        • Measurement Method of Arterial Shear Stress of Rats Model Based on Ultrasonic Particle Imaging Velocimetry

          The development and progression of atherosclerosis and thrombosis are closely related to changes of hemodynamics parameters. Ultrasonic pulse wave Doppler technique is normally used for noninvasively blood flow imaging. However, this technique only provides one-dimensional velocity and depends on the angle between the ultrasound beam and the local velocity vector. In this study, ultrasonic particle image velocimetry method was used to assess whole field hemodynamic changes in normal blood vessels. By using the polynomial fitting method, we investigated the velocity gradient and assessed the shear in different blood flow velocity of 10 healthy rats. It was found that using four polynomial fitting could result in optimal measurement results. The results obtained by ultrasonic particle image velocimetry accorded with the results obtained using Doppler technique. The statistical average of cyclical vessel wall shear stress was positively related to the locational mean velocity. It is proven that ultrasonic particle image velocimetry method could be used to assess directly the real-time whole field hemodynamic changes in blood vessels and was non-invasively, and should be a good prosperous technique for monitoring complex blood flow in stenotic arteries.

          Release date: Export PDF Favorites Scan
        • Procalcitonin-to-albumin ratio as a prognostic marker in acute respiratory distress syndrome patients: a retrospective cohort study

          ObjectiveTo explore the value of procalcitonin-to-albumin (PAR) in patients with acute respiratory distress syndrome (ARDS).MethodsA retrospective study was carried on patients diagnosed with ARDS from December 2016 to March 2018. The receiver-operating characteristics (ROC) curve was used to identify the cutoff value of PAR. The association of PAR and 28-day mortality was evaluated using univariate and multivariable Cox regression.ResultsIn the final analysis, there were a total of 255 patients included. Of whom 164 (64.3%) was male, 91 (35.7%) was female and the mean age was 52.1±14.5 years old. The 28-day mortality of all the patients was 32.9% (n=84). ROC curve revealed that the cutoff value of PAR was 0.039 (specificity: 0.714, sensitivity: 0.702) and area under the curve was 0.793 (95%CI: 0.735 - 0.850, P<0.001). The following variables were considered for multivariable adjustment: age, body mass index, pneumonia, aspiration, sepsis, surgery, PaO2/FiO2, red blood cell counts and PAR (P<0.01 in univariate analysis). After multivariable analysis, only age (HR: 1.033, 95%CI: 1.009 - 1.059, P=0.008), PaO2/FiO2 (HR: 0.992, 95%CI: 0.985 - 1.000, P=0.044) and PAR (HR: 4.899, 95%CI: 2.148 - 11.174, P<0.001) remained independently associated with 28-day mortality (P<0.05).ConclusionHigh PAR predicts a poor outcome in ARDS patients, therefore it appears to be a prognostic biomarker of outcomes in patients with ARDS.

          Release date:2020-07-24 07:00 Export PDF Favorites Scan
        • The Regulation of GSTM5 in Oxidative Stress Induced by TNF-α in Human Bronchus Epithelial Cells

          ObjectiveTo establish a cell inflammation model induced by tumor necrosis factor-α (TNF-α) in human bronchus epithelial cells, and investigate the effects of glutathione S-transferase mu 5 (GSTM5) on the inflammation and oxidative stress. Methods16HBE cells were treated with TNF-α (10 ng/mL, 24 h) in the absence or presence of the constructed GSTM5 eukaryotic expression vector (1 μg/mL). The concentration of malondialdehyde (MDA) and total antioxidation capacity (T-AOC) were detected by colorimetric method. The survival rate of cells was assessed by the methyl thiazolyl tetrazolium (MTT) assay. The transcription level of NADPH oxidase-1 (NOX1), NOX2, NOX3, NOX4, NOX5, dual oxidase-1 (DUOX1) and DUOX2 were evaluated by RT-PCR. Western blot was performed to investigate the protein levels of NOX1 and NOX2. ResultsTNF-α simulation significantly increased the level of MDA in cells, and decreased the level of T-AOC and survival rate of 16HBE. When transfected with the GSTM5 eukaryotic expression vector, the concentration of MDA significantly decreased (P < 0.05), and the activation of T-AOC increased dramatically (P < 0.05). Consequently, the survival rate of 16HBE in the GSTM5 group improved (P < 0.05). The 16HBE cells transfected with the constructed GSTM5 eukaryotic expression vector had a lower transcription and protein levels of NOX1 and NOX2 (all P < 0.01). There were no significant changes in the mRNA expressions of NOX3, NOX4, NOX5, DUOX1 or DUOX2. ConclusionGSTM5 may down-regulate the transcription level of NOX1 and NOX2 to reduce the inflammation and oxidative stress induced by TNF-α.

          Release date:2016-10-10 10:33 Export PDF Favorites Scan
        • Effects of nicotinamide mononucleotide adenylyl transferase 3 on mitochondrial function and anti-oxidative stress of rabbit bone marrow mesenchymal stem cells via regulating nicotinamide adenine dinucleotide levels

          ObjectiveTo investigate the effect of nicotinamide mononucleotide adenosyl transferase 3 (NMNAT3) on the mitochondrial function and anti-oxidative stress of rabbit bone marrow mesenchymal stem cells (BMSCs) under oxidative stress in vitro by regulating nicotinamide adenine dinucleotide (NAD+) levels.MethodsThe bone marrow of femur and tibia of New Zealand white rabbits were extracted. BMSCs were isolated and cultured in vitro by density gradient centrifugation combined with adherent culture. The third generation cells were identified by flow cytometry and multi-directional induction. Overexpression of NMNAT3 gene was transfected into rabbit BMSCs by enhanced green fluorescent protein (EGFP) labeled lentivirus (BMSCs/Lv-NMNAT3-EGFP), and then the expression of NMNAT3 was detected by real-time fluorescence quantitative PCR (qRT-PCR) and Western blot and cell proliferation by cell counting kit 8 (CCK-8) method. BMSCs transfected with negative lentivirus (BMSCs/Lv-EGFP) and untransfected BMSCs were used as controls. The oxidative stress injury cell model was established by using H2O2 to treat rabbit BMSCs. According to the experimental treatment conditions, they were divided into 4 groups: Group A was normal BMSCs without H2O2 treatment; untransfected BMSCs, BMSCs/Lv-EGFP, and BMSCs/Lv-NMNAT3-EGFP in groups B, C, and D were treated with H2O2 simulated oxidative stress, respectively. The effects of NMNAT3 on the mitochondrial function of BMSCs under oxidative stress [changes of mitochondrial membrane potential, NAD+ and adenosine triphosphate (ATP) levels], the changes of anti-oxidative stress ability of BMSCs [reactive oxygen species (ROS) and malondialdehyde (MDA) levels, manganese superoxide dismutase (Mn-SOD) and catalase (CAT) activities], and the effects of BMSCs on senescence and apoptosis [senescence associated-β-galactosidase (SA-β-gal) staining and TUNEL staining] were detected after 24 hours of treatment.ResultsThe rabbit BMSCs were successfully isolated and cultured in vitro. The stable strain of rabbit BMSCs with high expression of NMNAT3 gene was successfully obtained by lentiviral transfection, and the expressions of NMNAT3 gene and protein significantly increased (P<0.05). There was no significant difference in the trend of cell proliferation compared with normal BMSCs. After treatment with H2O2, the function of mitochondria was damaged and apoptosis increased in all groups. However, compared with groups B and C, the group D showed that the mitochondrial function of BMSCs improved, the membrane potential increased, the level of NAD+ and ATP synthesis of mitochondria increased; the anti-oxidative stress ability of BMSCs enhanced, the levels of ROS and MDA decreased, and the activities of antioxidant enzymes (Mn-SOD, CAT) increased; and the proportion of SA-β-gal positive cells and the rate of apoptosis decreased. The differences in all indicators between group D and groups B and C were significant (P<0.05).ConclusionNMNAT3 can effectively improve the mitochondrial function of rabbit BMSCs via increasing the NAD+ levels, and enhance its anti-oxidative stress and improve the survival of BMSCs under oxidative stress conditions.

          Release date:2020-06-15 02:43 Export PDF Favorites Scan
        • TREATMENT OF UPPER LIMB LYMPHEDEMA AFTER RADICAL MASTECTOMY WITH LIPOSUCTION TECHNIQUE AND PRESSURE THERAPY

          Objective To study a new method of treatment for upper limb lymphedema after radical mastectomy. Methods From Jun. 2001 to Sep. 2003, 11 cases(2with complication of erysipelas ) of upper limb lymphedema being treated with radical mastectomy for more than 2 years were used as model. All the edema of limbs was sucked from hypodermis with liposuction technique and compressed with compression garment. Three months after operation, elasticity stress was conducted every night. Results The reduction of the edema of upper limbswas remarkable. The average decrease of circumference was 4 cm. No erysipelas was observed. Conclusion The liposuction technique and elasticity stress is a new and effective approach to the treatment of upper limb lymphedema.

          Release date:2016-09-01 09:29 Export PDF Favorites Scan
        • Research progress of tibial transverse transport in treatment of chronic ischemic diseases of the lower extremities

          ObjectiveTo summarize the research progress of tibial transverse transport (TTT) in treatment of chronic ischemic diseases of the lower extremities.MethodsThe related literature was systematically searched and the mechanisms, clinical treatment methods, clinical efficacy, indications, contraindications, and complications of TTT were discussed.ResultsBased on the law of tension-stress, TTT is a new method in the treatment of chronic ischemic diseases of the lower extremities. It can relieve the ischemic symptoms, promote the wound healing, and increase the limb salvage rate. The clinical application in recent years has shown good effectiveness, and the scope of application is expanding.ConclusionDue to the current limited clinical application, the sample size of the TTT for the chronic ischemic diseases of the lower extremities is relatively small, and the follow-up time is limited. So its validity, long-term effectiveness, and bone transport standards are need further research.

          Release date:2020-08-19 03:53 Export PDF Favorites Scan
        • Effect of axial stress stimulation on tibial and fibular open fractures healing after Taylor space stent fixation

          Objective To investigate the effect of axial stress stimulation on tibial and fibular open fractures healing after Taylor space stent fixation. Methods The data of 45 cases with tibial and fibular open fractures treated by Taylor space stent fixation who meet the selection criteria between January 2015 and June 2016 were retrospectively analysed. The patients were divided into trial group (23 cases) and control group (22 cases) according to whether the axial stress stimulation was performed after operation. There was no significant difference in gender, age, affected side, cause of injury, type of fracture, and interval time from injury to operation between 2 groups (P>0.05). The axial stress stimulation was performed in trial group after operation. The axial load sharing ratio was tested, and when the value was less than 10%, the external fixator was removed. The fracture healing time, full weight-bearing time, and external fixator removal time were recorded and compared. After 6 months of external fixator removal, the function of the limb was assessed by Johner-Wruhs criteria for evaluation of final effectiveness of treatment of tibial shaft fractures. Results There were 2 and 3 cases of needle foreign body reaction in trial group and control group, respectively, and healed after symptomatic anti allergic treatment. All the patients were followed up 8-12 months with an average of 10 months. All the fractures reached clinical healing, no complication such as delayed union, nonunion, or osteomyelitis occurred. The fracture healing time, full weight-bearing time, and external fixator removal time in trial group were significantly shorter than those in control group (P<0.05). After 6 months of external fixator removal, the function of the limb was excellent in 13 cases, good in 6 cases, fair in 3 cases, and poor in 1 case in trial group, with an excellent and good rate of 82.6%; and was excellent in 5 cases, good in 10 cases, fair in 4 cases, and poor in 3 cases in control group, with an excellent and good rate of 68.2%, showing significant difference between 2 groups (Z=–2.146, P=0.032). Conclusion The axial stress stimulation of Taylor space stent fixation can promote the healing of tibial and fibular open fractures and promote local bone formation at fracture site.

          Release date:2017-08-03 03:46 Export PDF Favorites Scan
        • Application of Chronic Unpredictable Mild Stress Female Kunming Mice Model in the Field of Reproductive Medicine

          ObjectiveTo explore the effect of chronic unpredictable mild stress (CUMS) on the reproductive function of mice and provide a suitable animal model for reproduction and stress. MethodsA total of 240 female Kunming mice were feed for 5 days, and then divided randomly into the control group (n=90) and experimental group (n=150). The mice in the experimental group were stressed by 9 chronic mild unpredictable stress factors for 4 weeks and validated by open field test and sucrose consumption test. We administrated pregnant mare serum gonadotropin (PMSG)/human chorionic gonadotropin (HCG) for induction of superovulation and observed the ovarian response and embryo development potential. ResultsAfter 4-week CUMS stimulation, the weight gain, 2% sugar consumption test and open field test were significantly different between the mice in two groups (P>0.05). After PMSG/HCG was administrated, the antra follicles and preovulatory follicles significantly reduced significantly in the experiment group than that in the control group (P<0.05); the number of oocytes, fertilization rate, 2-cell embryos, D4 embryos, blastocysts, high quality embryo rate and D5 bed points were all significantly decreased in the experiment group than those in the control group (P<0.05). ConclusionThe CUMS female Kunming mice model is a kind of emotional stress animal model with low reproductive function, which is effective, operable and repeatable; it could be used for further study on the mechanism of reproductive medicine.

          Release date: Export PDF Favorites Scan
        • Application value of bedside pulmonary ultrasound in patients with acute respiratory distress syndrome

          Objective To explore the value of pulmonary ultrasound in the evaluation of pulmonary edema and the guidance of pulmonary therapy in patients with acute respiratory distress syndrome (ARDS). Methods Sixty patients with ARDS admitted to the Department of Critical Medicine of Shanghai Seventh People’s Hospital were randomly divided into a lung ultrasound group and a control group, with 30 patients in each group. The gender, age and etiology of patients were collected, and the relevant data were recorded at the time of admission and on the 7th day, including Acute Physiology and Chronic Health Evaluation Ⅱ (APACHEⅡ) score, Sequential Organ Failure Assessment score (SOFA), white blood cell count (WBC), C-reactive protein (CRP), procalcitonin (PCT), extravascular pulmonary water index, oxygenation index, and mechanical ventilation treatment time. Pulmonary ultrasound score was collected in the pulmonary ultrasound group. The 7-day improvement rate, intensive care unit (ICU) hospitalization time and 28 day mortality rate of the two groups were also collected. The value of pulmonary ultrasound in evaluating the severity, treatment process and prognosis of patients, and the correlation between pulmonary ultrasound score and extravascular pulmonary water index were studied. Results There was no significant difference in APACHEⅡ score, SOFA score, oxygenation index, extravascular pulmonary water index, WBC, CRP or PCT between the two groups before and after treatment (all P>0.05). After 7 days of treatment, the two groups improved, and the pulmonary ultrasound group improved more significantly with more shorter mechanical ventilation time, higher 7-day improvement rate, shorter ICU hospitalization time, and lower 28-day mortality rate (all P<0.05). The extravascular pulmonary water index was positively correlated with APACHEⅡ score and SOFA score, and negatively correlated with oxygenation index. The pulmonary ultrasound score was positively correlated with APACHEⅡ, and SOFA score and extravascular pulmonary water index, and negatively correlated with oxygenation index. Conclusions Pulmonary ultrasound can effectively evaluate the severity of ARDS patients, guide the individualized treatment, and predict the prognosis. It can be used as a routine monitoring method for patients with ARDS.

          Release date:2020-01-15 11:30 Export PDF Favorites Scan
        • Effects of Intervertebral Disc Degeneration on Biomechanics Behavior Characteristics of L4-L5 Under the Vertical Load

          A geometrical model of L4-L5 lumbar segment was constructed using a three-dimensional graphics software. Four conditions of the degenerated discs, i.e. light degeneration, moderate degeneration, severe degeneration and complete excision degeneration, were simulated with loading situations using finite element method under the condition of appropriate computational accuracy. By applying a vertical load of 378.93 N on L4 vertebral plate, stress nephograms on joint isthmus under four different working conditions were obtained. The results showed that the contacted area of facet joint was influenced by the degree of intervertebral disc degeneration level, which influenced the mises stress on joint isthmus. It was proved that joint isthmus was the important pressure-proof structure of the back of lumbar vertebra, and the stress values and distribution were related to structural stiffness of the back of lumbar vertebra as well as the contact area of facet joint. The conclusion could be the theoretical reference for the analysis of spinal biomechanics and artificial disc replacement as well.

          Release date:2021-06-24 10:16 Export PDF Favorites Scan
        28 pages Previous 1 2 3 ... 28 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