Calculation of the X-ray spectrum of a mammography system with various voltages and different anode-filter combinations using MCNP code

Introduction One of the best methods in the diagnosis and control of breast cancer is mammography. The importance of mammography is directly related to its value in the detection of breast cancer in the early stages, which leads to a more effective treatment. The purpose of this article was to calculate the X-ray spectrum in a mammography system with Monte Carlo codes, including MCNPX and MCNP5. Materials and Methods The device, simulated using the MCNP code, was Planmed Nuance digital mammography device (Planmed Oy, Finland), equipped with an amorphous selenium detector. Different anode/filter materials, such as molybdenum-rhodium (Mo-Rh), molybdenum-molybdenum (Mo-Mo), tungsten-tin (W-Sn), tungsten-silver (W-Ag), tungsten-palladium (W-Pd), tungsten-aluminum (W-Al), tungsten-molybdenum (W-Mo), molybdenum-aluminum (Mo-Al), tungsten-rhodium (W-Rh), rhodium-aluminum (Rh-Al), and rhodium-rhodium (Rh-Rh), were simulated in this study. The voltage range of the X-ray tube was between 24 and 34 kV with a 2 kV interval. Results The charts of changing photon flux versus energy were plotted for different types of anode-filter combinations. The comparison with the findings reported by others indicated acceptable consistency. Also, the X-ray spectra, obtained from MCNP5 and MCNPX codes for W-Ag and W-Rh combinations, were compared. We compared the present results with the reported data of MCNP4C and IPEM report No. 78 for Mo-Mo, Mo-Rh, and W-Al combinations. Conclusion The MCNPX calculation outcomes showed acceptable results in a low-energy X-ray beam range (10-35 keV). The obtained simulated spectra for different anode/filter combinations were in good conformity with the finding of previous research

Conjugated Alpha-Alumina nanoparticle with vasoactive intestinal peptide as a Nano-drug in treatment of allergic asthma in mice

Asthma is a chronic respiratory disease characterized by airway inflammation, bronchoconstriction, airway hyperresponsiveness and recurring attacks of impaired breathing. Vasoactive intestinal peptide (VIP) has been proposed as a novel anti-asthma drug due to its effects on airway smooth muscle relaxation, bronchodilation and vasodilation along with its immunomodulatory and anti-inflammatory properties. In the current study, we investigated the therapeutic effects of VIP when conjugated with α-alumina nanoparticle (α-AN) to prevent enzymatic degradation of VIP in the respiratory tract. VIP was conjugated with α-AN. Balb/c mice were sensitized and challenges with ovalbumin (OVA) or PBS and were divided in four groups; VIP-treated, α-AN-treated, α-AN-VIP-treated and beclomethasone-treated as a positive control group. Specific and total IgE level, airway hyperresponsiveness (AHR), bronchial cytokine expression and lung histology were measured. α-AN-VIP significantly reduced the number of eosinophils (Eos), serum IgE level, Th2 cytokines and AHR. These effects of α-AN-VIP were more pronounced than that seen with beclomethasone or VIP alone (P<0.05). The current data indicate that α-AN-VIP can be considered as an effective nano-drug for the treatment of asthma

Effect of waste materials on acoustical properties of semi-dense asphalt mixtures

Among the urban societal burdens rolling noise generation from tire pavement interaction and urban waste stand apart. Many urban waste materials can be used in pavements with comparable mechanical performance. Noise-related pavement characteristics such as porosity, sound absorption and surface texture, were measured for semi-dense low noise pavement mixtures using urban waste materials namely: recycled concrete aggregates, crumb rubber, polyethylene terephthalate and polyethylene. The results show that the use of these materials is a viable sustainable option for low noise pavements, however that may affect the noise reduction properties. With values around 0.2 at 1000 Hz, the sound absorption of all the mixtures is relatively low and the use of mean profile depth (MPD) alone is not enough to characterize the noise reduction properties. Surface texture was altered in different degrees depending on the waste material used. The results presented can aid in policy pertaining to noise abatement and waste reduction

Tourism Firms’ Vulnerability to Risk: The Role of Organizational Slack in Performance and Failure

This study explores the influence of political risk on firms in the tourism industry. It addresses a research gap regarding the impact of political risk on firm-level performance and failure and uncovers the role of organizational slack in this relationship. Firm-level political risk is estimated from 2002 to 2019 financial data for firms across six tourism sectors in a developed economy, the United States. Such risk is found to be significantly associated with firm performance and business failure. From the perspectives of the resource-based view and the threat-rigidity hypothesis, the results support the moderating effects of absorbed and unabsorbed slack on links between risk, performance, and business failure. Given that the COVID-19 pandemic has highlighted the tourism industry’s vulnerability, this study will be of interest to tourism firms seeking to improve business sustainability and resilience

Management of spine trauma in COVID-19 pandemic: A preliminary report

Background: COVID-19 was first identified in Iran in February 2020 and since then it spread rapidly through all over the country and soon after that it was reported as a pandemic. The current study presents a preliminary report of spine trauma management during COVID-19 pandemic. Methods: A cross sectional study was designed to evaluate patients admitted for vertebral fractures with diagnosis of COVID-19 infection on February and March 2020. Analysis was made based on clinical and laboratory data along with the imaging findings from chest HRCT. Results: Seven patients with spine trauma including five males and two females ranging from 14 to 59 years were diagnosed for COVID-19 infection through CT-scan findings. Except one, all other patients were asymptomatic for COVID-19 at the time of admission. In three cases the COVID diagnosis was made the day after arrival and in others after 10, 14 and 35 days. Five patients were treated surgically among whom four were admitted to ICU soon after the surgery. The mean ICU stay for operated patients were eight days and the mean hospital stay was 22.6 days. Conclusion: Proper diagnosis of COVID-19 is the keystone to protect both patients and health care providers. During the pandemic all admitted patients should be screened for COVID-19 infection. Unnecessary procedures for spine trauma patients should be avoided in order to reduce complications related to surgery and to preserve ICU beds. © 2020 BY THE ARCHIVES OF BONE AND JOINT SURGERY

Effects of antioxidant supplementations on oxidative stress in rheumatoid arthritis patients

Reactive Oxygen Species (ROS) play an important role in the pathogenesis of Rheumatoid Arthritis (RA) exposing these patients to oxidative stress. The aim of the present study was to evaluate the effects of antioxidant supplementations on oxidative status and disease activity in RA patients. Forty nine RA patients (41 females, 8 males, age 48.78±12.54 years) participated in this randomized clinical trial. Patients were randomly divided into two groups to received antioxidant supplementations in combined with conventional treatment (Group I, n: 24) or conventional treatment only (group II, n: 25) for 12 weeks. Plasma concentration of malondialdehyde (MDA) and Total Antioxidant Capacity (TAC) were measured at the beginning of the study and after intervention in both groups. Disease activity was also measured before and after intervention using Rheumatoid Arthritis Disease Activity Index (RADAI). Supplementation with antioxidant yielded significantly decreased in plasma MDA concentration (p<0.0001) and disease activity (p<0.0001) and statistically increased in TAC levels (p<0.0001) in group I in comparison to group II after 12 weeks. This study indicates that antioxidant supplementations may play an important role in improving oxidative stress and decreasing disease activity in these patients. © 2010 Asian Network for Scientific Information

Refurbishment of public housing villas in the United Arab Emirates (UAE): energy and economic impact

© 2016, Springer Science+Business Media Dordrecht. This study aims at assessing the technical and economic benefits of refurbishing existing public housing villas in the UAE. Four representative federal public housing villas built between 1980s and 2010s were modeled and analyzed. The Integrated Environmental Solutions-Virtual Environment (IES-VE) energy modeling software was used to estimate the energy consumption and savings due to different refurbishment configurations applied to the villas. The refurbishment technical configurations were based on the UAE’s Estidama green buildings sustainability assessment system. The refurbishment configurations include upgrading three elements: the wall and roof insulation as well as replacing the glazing. The annual electricity savings results indicated that the most cost-efficient refurbishment strategy is upgrading of wall insulation (savings up to 20.8 %) followed by upgrading the roof’s insulation (savings up to 11.6 %) and lastly replacing the glazing (savings up to 3.2 %). When all three elements were refurbished simultaneously, savings up to 36.7 % were achieved (villa model 670). The savings translated to CO2 emission reduction of 22.6 t/year. The simple and discounted payback periods for the different configurations tested ranged between 8 and 28 and 10 and 50 years, respectively

Serum IL-33, a new marker predicting response to rituximab in rheumatoid arthritis

Background. Recent works have suggested a possible link between IL-33 and B-cell biology. We aimed to study in different cohorts and with an accurate ELISA assay the possible association between serum IL-33 detection and response to rituximab (RTX) in rheumatoid arthritis (RA) patients. Method. Serum IL-33, rheumatoid factor (RF), anti-citrullinated cyclic peptide antibodies (anti-CCP), high serum IgG level were assessed in 111 RA patients receiving a first course of 2 grams RTX (cohort 1) in an observational study and in 74 RA patients treated with the same schedule in routine care (cohort 2). Uni and multivariate analyzes identified factors associated with a European League Against Rheumatism response at 24 weeks. Results. At week 24, 84/111 (76%) and 54/74 (73%) patients reached EULAR response in the cohorts 1 and 2, respectively. Serum IL-33 was detectable in only 33,5% of the patients. In the combined cohorts, presence of RF or anti-CCP (OR 3.27, 95%CI [1.13-9.46]; p=0.03), high serum IgG (OR 2.32, 95%CI [1.01-5.33]; p=0.048) and detectable serum IL-33 (OR 2.40, 95%CI [1.01-5.72]; p=0.047) were all associated with RTX response in multivariate analysis. Combination of these 3 factors increased the likelihood to response to RTX. When serum IL-33 detection was added to seropositivity and serum IgG level, 100% of the patients with the 3 risk factors (corresponding to 9% of the population) responded to RTX (OR versus patients with none of the 3 risk factors = 29.61; 95% CI [1.30-674.79] p=0.034) Conclusion. Detectable serum IL-33 may predict clinical response to RTX, independently of and synergistically with autoantibodies and serum IgG level