30 research outputs found
Non-minimal Derivative Coupling Scalar Field and Bulk Viscous Dark Energy
Inspired by thermodynamical dissipative phenomena, we consider bulk viscosity
for dark fluid in a spatially flat two-component Universe. Our viscous dark
energy model represents Phantom crossing avoiding Big-Rip singularity. We
propose a non-minimal derivative coupling scalar field with zero potential
leading to accelerated expansion of Universe in the framework of bulk viscous
dark energy model. In this approach, coupling constant () is related to
viscosity coefficient () and energy density of dark energy at the
present time (). This coupling is bounded as and for leads to . To
perform robust analysis, we implement recent observational data sets including
Joint Light-curve Analysis (JLA) for SNIa, Gamma Ray Bursts (GRBs) for most
luminous astrophysical objects at high redshifts, Baryon Acoustic Oscillations
(BAO) from different surveys, Hubble parameter from HST project, {\it Planck}
data for CMB power spectrum and CMB Lensing. Joint analysis of
JLAGRBsBAOHST shows that ,
and at confidence interval.
{\it Planck} TT observation provides at
confidence limit for viscosity coefficient. Tension in Hubble parameter is
alleviated in this model. Cosmographic distance ratio indicates that current
observed data prefer to increase bulk viscosity. Finally, the competition
between Phantom and Quintessence behavior of viscous dark energy model can
accommodate cosmological old objects reported as a sign of age crisis in
CDM model.Comment: 21 pages and 18 figures, some typos in equations fixe
Passivhaus summer overheating: the development of an effective natural ventilation system
Concern regarding overheating potential has been growing in the UK as buildings are being built to higher standards like Passivhaus. Lack of window operation due to noise and security implications specifically at night, alongside higher expected temperatures in the future can only add to this concern. Furthermore the quality of incoming fresh air through windows in Passivhaus dwellings could be lower compared to filtered air in MVHR systems. The aim of this research is to investigate the possibility of overheating in reference Passivhaus dwellings and consequently, to examine and propose a remedial natural ventilation strategy and system for the non-winter period. The internal temperatures, indoor CO2 levels alongside frequency and duration of window openings were recorded using data loggers and sensors. A dynamic thermal model was created in DesignBuilder using data from the original PHPP model and further amended by results from monitoring, creating a base case model. A specific natural ventilation system was modelled using the base case model to increase efficiency and effectiveness of natural ventilation. The proposed system was also tested for the winter period in terms of airtightness and thermal bridging as well as forecasted future climate data. The proposed system increases natural ventilation rates compared to the original design, thereby reducing summer overheating for current and future climate by around 20%. Passivhaus designers can benefit from this system for new building designs or for refurbishment of existing Passivhaus building stock that could encounter overheating in the future. The system can be tested in the PHPP calculation allowing the elimination of all window operations during the cooling season
Successful management of a very large common hepatic duct stone in a patient with pancreaticoduodenectomy by use of cholangioscopy and electrohydraulic lithotripsy
Airway observations during upper endoscopy predicting obstructive sleep apnea
Background This pilot study examined airway characteristics during upper endoscopy to determine who is at high risk for obstructive sleep apnea.
Methods Patients undergoing routine upper endoscopy were divided into 2 groups according to the Berlin Questionnaire (high and low risk for sleep disordered breathing). Patients underwent routine upper endoscopy using propofol sedation. The airway was then evaluated for no, partial, or complete collapse at the levels of the palate/uvula/tonsils, the tongue base, the hypopharynx, and the larynx. They were given a score of 0 for no collapse, 1 for partial collapse, and 2 for complete collapse. The score for each of these levels was added to give a total score or severity index. The larynx was also evaluated for lateral pharyngeal collapse (minimal, up to 50%, >50%, or 100%).
Results We found that patients with a partial obstruction at the level of the palate/uvula/tonsils, tongue base, hypopharynx, or larynx, or complete obstruction at any level more often had a positive Berlin questionnaire. Patients with a positive Berlin questionnaire were more often of increased weight (mean 197 vs 175 lbs, P=0.19), increased body mass index (31.2 vs 27.42 kg/m2, P=0.11), increased neck circumference (36.7 vs 34.7 cm, P=0.23), and had a higher total airway score (2.61 vs 1.67, P=0.09).
Conclusions The results of our pilot study represent preliminary data regarding the use of upper endoscopy as a potential tool to evaluate patients for obstructive sleep apnea
Clinical Manifestations of β-Thalassemia Major in Two Different Altitudes; Bushehr and Shahrekord
Background: Patients with β-thalassemia major (TM) develop iron overload through increased iron
absorption and transfusional therapy and it’s the most important complication of TM. Thalassemia is common
in coastal regions and lands with low altitudes. The aim of this study is to determine the effect of high and low
altitude on serum ferritin and treatment requirement in two groups of β-thalassemia major (TM) patients.
Subjects and Methods: Patients were divided into two groups, the first group (No: 50) living at sea level (in
the port of Bushehr, Iran) and the second group (No: 40) living at the altitude of 2061 m (in the city of
Shahrekord, Iran). All patient’s clinical history, blood transfusion and laboratory tests including complete blood
count and hemoglobin electrophoresis were reviewed.
Results: There were no significant difference in ferritin levels, transfusion period and diabetes incidence of
the two cities patients (P>0.05). Patient’s cardiac function and liver condition were significantly better in
patients of Bushehr (P<0.05). Patients under 20 years in Bushehr were less splenectomized in comparison
with Shahrekord (P<0.05).
Conclusion: Our result showed that some of clinical manifestations of patients in low altitude such as cardiac
and liver condition were better. But it did not affect ferritin level probably due to transfusion and chelating
therapy. Totally patients of Bushehr had better conditions and had longer survivals.
Keywords: β-thalassemia major, Ferritin level, Cardiac function, Altitud
TLR9-based immunotherapy for the treatment of allergic diseases
Toll-like receptors (TLRs), a family of pattern recognition receptors expressed on many
cell types of innate immunity, recognize the pathogen-associated molecular patterns
of microbes. The hygiene hypothesis suggests that a reduced microbial exposure
in early childhood increases the susceptibility to allergic diseases due to deviation
in development of the immune system. TLRs are key roles in the right and healthy
direction of adaptive immunity with the induction of T-helper 2 toward Th1 immune
responses and regulatory T cells. TLR ligand CpG-ODN-based immunomodulation
is independent of allergen and it mainly affects innate immune system. While,
CpG-oligodeoxynucleotide-based vaccination is allergen specific and induces
adaptive immune system. The use of agonists of TLR9 in two distinct strategies of
immunotherapy, immunomodulation and vaccination, could be presented as the
curative method for the treatment of allergic diseases.
First draft submitted: 29 August 2016; Accepted for publication: 8 February 2017;
Published online: 17 March 2017
Keywords:  allergic diseases • immunotherapy • TLR9 • Toll-like receptor
Serological, pathological and scintigraphic assessment of Hemiscorpius lepturus effects on renal dysfunction in rats
Objective(s): Hemiscorpius lepturus is one of the dangerous scorpions of Iran leading to acute kidney injury (AKI) especially in infants. The purpose of this animal study was to compare the serological, pathological and scintigraphic data to quickly predict the occurrence of this disorder.Materials and Methods: In two groups of animals, each contained five rats, H. lepturus venom (1200 µg/Kg) were injected intravenously via the tail vein. At three hours and one week later, 99m Tc-DMSA (3 mCi) was intravenously injected and renal scintigraphy was performed after an hour. Moreover, plasma levels of creatinine, sodium, potassium, and blood urea nitrogen (BUN) were measured. At the end of the study, renal tissues were excised and prepared to perform pathological evaluation after Hematoxylin and Eosin staining.Results: All serological indices were remained unchanged compared to control. A large number of glomerular fibrin thrombi with entrapped red blood cells and simplified tubular epithelium in dilated and ectatic tubules were observed in high power field (×100) four hours after envenomation, which reduced significantly one week later. In our scintigraphic study, there was a statistically significant difference (
Dusty Air Pollution is Associated with an Increased Risk of Allergic Diseases in Southwestern Part of Iran
Concerns have been raised about the adverse impact of dusty air pollution (DAP) on
human health. The aim of this study was to find the association between dusty air pollution
based on air quality index (AQI) and the risk of allergic diseases in southwestern provinces
of Iran, with assessing cytokine profiles and lymphocyte immunophenotypes.
In this case control study 148 individuals participated. The sampling was done in
hazardous condition (AQI >300) as the case and clean air (AQI <50) as the control. We
measured cytokine production by using ELISA method and phenotypes of T-lymphocytes
(CD4+ and CD8+), CD19+ B-lymphocytes, CD25+, CD4+ CD25+ cells by FACSort flow
cytometer.
The mean serum level of IL-4 (33.4±2.9 vs 0.85± 0.65 pg/dl) and IL-13 (15.1±4.4 vs.
0.12±0.7 pg/dl) in the subjects exposed to ambient DAP was increased significantly
compared to the individuals in the clean air condition. Also, CD19+ B-lymphocytes (12.6±
4.9 vs 8.9±3.2%) and CD4+ CD25+ cell count (13.6± 4.6 vs 7.7± 3.8%) in peripheral blood
were increased significantly in subjects exposed to ambient DAP compared with the
controls.
The result of our study suggested that ambient DAP affected immune system in a way
that might lead to allergic diseases in the population
Beneficial Effects of Exercise Training in Patients with Chronic Heart Failure
Several human and experimental studies have been performed to show the effects of exercise training on chronic heart failure (CHF). These studies have shown that exercise improves the adverse pathophysiologic changes which occur with CHF, including enhanced exercise capacity, ventilation, skeletal muscle metabolism, cardiac function, quality of life, and peripheral blood flow. In addition, there is an improved modulation of inflammatory, autonomic, and hormonal dysregulation after exercise training. This review focuses on the current evidence surrounding the beneficial effects of exercise training in CHF patients