127 research outputs found
A novel semi-active TMD with folding variable stiffness spring
An innovative variable stiffness device is proposed and investigated based on numerical simulations. The device, called a folding variable stiffness spring (FVSS), can be widely used, especially in tuned mass dampers (TMDs) with adaptive stiffness. An important characteristic of FVSS is its capability to change the stiffness between lower and upper bounds through a small change of distance between its supports. This special feature results in lower time-lag errors and readjustment in shorter time intervals. The governing equations of the device are derived and simplified for a symmetrical FVSS with similar elements. This device is then used to control a single-degree-of-freedom (SDOF) structure as well as a multi-degree-of-freedom (MDOF) structure via a semi-active TMD. Numerical simulations are conducted to compare several control cases for these structures. To make it more realistic, a real direct current motor with its own limitations is simulated in addition to an ideal control case with no limitations and both the results are compared. It is shown that the proposed device can be effectively used to suppress undesirable vibrations of a structure and considerably improves the performance of the controller compared to a passive device
Scintigraphic evaluation of remote pre-conditioning protection against unilateral renal ischemia/reperfusion injury in rats: a longitudinal study
Purpose: To determine the role of remote perconditioning (RPeC) on renal function and histology in an animal model of unilateral renal ischemia and reperfusion (IR) injury. Methods: Rats were subjected to 60 min unilateral renal ischemia. RPeC protocol was the application of four cycles of 5 min IR of left femoral artery during renal ischemia. Assessments of histological changes and renal function were made 24 h, 1 week, or 3 weeks later. 99mTc-DMSA scan was performed using a small-animals SPECT system. Results: 24-h reperfusion decreased the 99mTc-DMSA uptake in the left kidney compared to the intact kidney of control animals. RPeC group has higher uptake compared to the IR group. After 1 week and 3 weeks, uptakes were gradually increased in both groups and no differences were observed. Severe morphological changes in the ischemic kidneys of both groups were observed after 24 h which attenuated after 1 week and 3 weeks. Moreover, no differences in creatinine and BUN levels between IR-treated and intact animals were observed. Conclusion: These data suggest that RPeC exerts a partially transient improvement in the renal function in the first day after reperfusion. However, long-term follow-up study showed no beneficial effects of RPeC. Moreover, noninvasive 99mTc-DMSA scan revealed a suitable tool in the follow-up evaluation of recovery process in the unilateral renal IR injury models
Restless Legs Syndrome in Iranian People With Type 2 Diabetes Mellitus: The Role in Quality of Life and Quality of Sleep
Study Objectives: To investigate the prevalence of restless legs syndrome (RLS) in patients with type 2 diabetes mellitus (T2DM) and explore its role in quality of life (QoL) and quality of sleep of these patients. Methods: This is a cross-sectional study performed on 210 Iranian people with T2DM. The diagnosis of RLS was established based on the essential diagnostic criteria for RLS recommended by the National Institutes of Health. Sleep quality and QoL were assessed in all participants using Pittsburgh Sleep Quality Index and EuroQol five-dimension questionnaire, respectively. Regression models were used for final analysis of data. Results: The prevalence of RLS was 19.5; of whom 38.1 had poor quality of sleep. Male sex, being single, body mass index (BMI), and RLS were associated with poor quality of sleep. Patients with RLS were almost three times as likely as the patients without RLS to have poor sleep quality. Moreover, being female, BMI value, level of glycosylated hemoglobine (HbA1C), and RLS were associated with lower QoL. RLS lowers the score of QoL even more than BMI and HbA1C. In addition, the QoL and sleep quality of this population of patients with diabetes have not been affected by the severity of RLS as well as presence or absence of neuropathy. Conclusions: RLS has an independent and significant role in sleep quality and QoL in the patients with diabetes. Neuropathy with RLS does not confer any additive burden on QoL and sleep quality of this population of patients with diabetes
Restless Legs Syndrome in Iranian People With Type 2 Diabetes Mellitus: The Role in Quality of Life and Quality of Sleep
Study Objectives: To investigate the prevalence of restless legs syndrome (RLS) in patients with type 2 diabetes mellitus (T2DM) and explore its role in quality of life (QoL) and quality of sleep of these patients. Methods: This is a cross-sectional study performed on 210 Iranian people with T2DM. The diagnosis of RLS was established based on the essential diagnostic criteria for RLS recommended by the National Institutes of Health. Sleep quality and QoL were assessed in all participants using Pittsburgh Sleep Quality Index and EuroQol five-dimension questionnaire, respectively. Regression models were used for final analysis of data. Results: The prevalence of RLS was 19.5; of whom 38.1 had poor quality of sleep. Male sex, being single, body mass index (BMI), and RLS were associated with poor quality of sleep. Patients with RLS were almost three times as likely as the patients without RLS to have poor sleep quality. Moreover, being female, BMI value, level of glycosylated hemoglobine (HbA1C), and RLS were associated with lower QoL. RLS lowers the score of QoL even more than BMI and HbA1C. In addition, the QoL and sleep quality of this population of patients with diabetes have not been affected by the severity of RLS as well as presence or absence of neuropathy. Conclusions: RLS has an independent and significant role in sleep quality and QoL in the patients with diabetes. Neuropathy with RLS does not confer any additive burden on QoL and sleep quality of this population of patients with diabetes
The effect of LINC01296 expression in patients with cancer: A systematic review and meta-analysis
Background: Recently has been suggested that LINC01296 has an important role in tumor-promoting in different malignancies. We performed first meta-analysis to assess the association between the LINC01296 expression and clinicopathological criteria and the survival of patients with cancers. Methods: Relevant articles Identified by PubMed, EMBASE, Web of Science, and Scopus searching between December 2000 and 28 December 2018. Binomial data were evaluated by the odds ratio (OR) as the rapid statistic. The association between overall survival (OS) and the LINC01296 expression was evaluated using pooling the hazard ratio (HR) with its corresponding 95 confidence interval (CI). Results: Finally, 9 studies with 720 patients with cancer were included. The expression of LINC01296 showed a significant positive association with TNM stage (OR = 2.67, 95 CI = 1.83-3.88), tumor stage (OR= 2.22, 95 CI= 1.34-3.66) and lymph node metastasis (OR = 3.07, 95 CI = 2.23-4.21). A shorter OS was significantly associated with the expression of LINC01296 (HR = 3.95, 95 CI = 2.65-5.25) and lymph node metastasis (HR = 2.39, 95 CI =1.16-3.63). The OS did not show significant association with gender (HR = 0.83, 95 CI =-0.63-2.30) and tumor stage (HR= 2.66, 95 CI=-0.22-5.54). Conclusion: In conclusion, the results of this meta-analysis suggest that the expression of LINC01296 might be considered as a potential biomarker in patients with cancer. © 2020 Asian Pacific Organization for Cancer Prevention
Evaluation of the effects of pycnogenol (French maritime pine bark extract) supplementation on inflammatory biomarkers and nutritional and clinical status in traumatic brain injury patients in an intensive care unit: A randomized clinical trial protocol
Background: Traumatic brain injury (TBI) is one of the major health and socioeconomic problems in the world. Immune-enhancing enteral formula has been proven to significantly reduce infection rate in TBI patients. One of the ingredients that can be used in immunonutrition formulas to reduce inflammation and oxidative stress is pycnogenol. Objective: The objective of this work is to survey the effect of pycnogenol on the clinical, nutritional, and inflammatory status of TBI patients. Methods: This is a double-blind, randomized controlled trial. Block randomization will be used. An intervention group will receive pycnogenol supplementation of 150 mg for 10 days and a control group will receive a placebo for the same duration. Inflammatory status (IL-6, IL- 1β, C-reactive protein) and oxidative stress status (malondialdehyde, total antioxidant capacity), at the baseline, at the 5th day, and at the end of the study (10th day) will be measured. Clinical and nutritional status will be assessed three times during the intervention. The Sequential Organ Failure Assessment (SOFA) questionnaire for assessment of organ failure will be filled out every other day. The mortality rate will be calculated within 28 days of the start of the intervention. Weight, body mass index, and body composition will be measured. All analyses will be conducted by an initially assigned study arm in an intention-to-treat analysis. Discussion: We expect that supplementation of 150 mg pycnogenol for 10 days will improve clinical and nutritional status and reduce the inflammation and oxidative stress of the TBI patients. Trial registration: This trial is registered at clinicaltrials.gov (ref: NCT03777683) at 12/13/2018. © 2020 The Author(s)
Prevalence of Osteosarcopenia and Its Association with Cardiovascular Risk Factors in Iranian Older People: Bushehr Elderly Health (BEH) Program
Osteosarcopenia is an increasingly recognized geriatric syndrome with a considerable prevalence which increases morbidity and mortality. Although osteosarcopenia is a result of age-related deterioration in muscle and bone, there are many risk factors that provoking osteosarcopenia. These risk factors should be considered by the clinicians to treat osteosarcopenia. We assessed the link between osteosarcopenia and conventional risk factors of cardiovascular diseases. This study was a cross-sectional study that has been conducted within the framework of Bushehr Elderly Health (BEH) program stage II in which participants aged ≥ 60 years were included. Osteopenia/osteoporosis was defined as a t-score ≤ − 1.0 standard deviation below the mean values of a young healthy adult. We defined sarcopenia as reduced skeletal muscle mass plus low muscle strength and/or low physical performance. Osteosarcopenia was considered as the presence of both osteopenia/osteoporosis and sarcopenia. We estimated the age-standardized prevalence of osteosarcopenia for men and women, separately. Using modified Poisson regression analysis, adjusted prevalence ratio (PR) with 95% CI was used to show the measure of associations in the final model. Among 2353 participants, 1205 (51.2%) were women. Age-standardized prevalence of osteosarcopenia was 33.8 (95% CI 31.0–36.5) in men and 33.9 (30.9–36.8) in women. In both sexes, the inverse association was detected with body mass index and having osteosarcopenia (PR 0.84, 95% CI 0.81–0.88 in men and 0.77, 95% CI 0.74–0.80 in women). In both sexes, high-fat mass was positively associated with osteosarcopenia [PR 1.46 (95% CI 1.11–1.92) in men, and 2.25 (95% CI 1.71–2.95) in women]. Physical activity had a significant inverse association in men (PR = 0.64, 95% CI 0.46, 0.88), but not in women. Diabetes was also showed a direct association with osteosarcopenia in men (PR 1.33, 95% CI 1.04–1.69). No associations were detected between the lipid profiles and osteosarcopenia. Results demonstrated a high prevalence of osteosarcopenia in both sexes suggesting a high disease burden in a rapidly aging country. Lifestyle and socioeconomic factors, as well as chronic diseases, were significantly associated with osteosarcopenia
Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR
Substantial experimental and theoretical efforts worldwide are devoted to
explore the phase diagram of strongly interacting matter. At LHC and top RHIC
energies, QCD matter is studied at very high temperatures and nearly vanishing
net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was
created at experiments at RHIC and LHC. The transition from the QGP back to the
hadron gas is found to be a smooth cross over. For larger net-baryon densities
and lower temperatures, it is expected that the QCD phase diagram exhibits a
rich structure, such as a first-order phase transition between hadronic and
partonic matter which terminates in a critical point, or exotic phases like
quarkyonic matter. The discovery of these landmarks would be a breakthrough in
our understanding of the strong interaction and is therefore in the focus of
various high-energy heavy-ion research programs. The Compressed Baryonic Matter
(CBM) experiment at FAIR will play a unique role in the exploration of the QCD
phase diagram in the region of high net-baryon densities, because it is
designed to run at unprecedented interaction rates. High-rate operation is the
key prerequisite for high-precision measurements of multi-differential
observables and of rare diagnostic probes which are sensitive to the dense
phase of the nuclear fireball. The goal of the CBM experiment at SIS100
(sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD
matter: the phase structure at large baryon-chemical potentials (mu_B > 500
MeV), effects of chiral symmetry, and the equation-of-state at high density as
it is expected to occur in the core of neutron stars. In this article, we
review the motivation for and the physics programme of CBM, including
activities before the start of data taking in 2022, in the context of the
worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal
Actor-partner effects associated with experiencing intimate partner violence or coercion among male couples enrolled in an HIV prevention trial
Engineered Single-Domain Antibodies with High Protease Resistance and Thermal Stability
The extreme pH and protease-rich environment of the upper gastrointestinal tract is a major obstacle facing orally-administered protein therapeutics, including antibodies. Through protein engineering, several Clostridium difficile toxin A-specific heavy chain antibody variable domains (VHHs) were expressed with an additional disulfide bond by introducing Ala/Gly54Cys and Ile78Cys mutations. Mutant antibodies were compared to their wild-type counterparts with respect to expression yield, non-aggregation status, affinity for toxin A, circular dichroism (CD) structural signatures, thermal stability, protease resistance, and toxin A-neutralizing capacity. The mutant VHHs were found to be well expressed, although with lower yields compared to wild-type counterparts, were non-aggregating monomers, retained low nM affinity for toxin A, albeit the majority showed somewhat reduced affinity compared to wild-type counterparts, and were capable of in vitro toxin A neutralization in cell-based assays. Far-UV and near-UV CD spectroscopy consistently showed shifts in peak intensity and selective peak minima for wild-type and mutant VHH pairs; however, the overall CD profile remained very similar. A significant increase in the thermal unfolding midpoint temperature was observed for all mutants at both neutral and acidic pH. Digestion of the VHHs with the major gastrointestinal proteases, at biologically relevant concentrations, revealed a significant increase in pepsin resistance for all mutants and an increase in chymotrypsin resistance for the majority of mutants. Mutant VHH trypsin resistance was similar to that of wild-type VHHs, although the trypsin resistance of one VHH mutant was significantly reduced. Therefore, the introduction of a second disulfide bond in the hydrophobic core not only increases VHH thermal stability at neutral pH, as previously shown, but also represents a generic strategy to increase VHH stability at low pH and impart protease resistance, with only minor perturbations in target binding affinities. These are all desirable characteristics for the design of protein-based oral therapeutics
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