Application of silicon-polymer composite varistors to protect sensitive medical imaging circuits and performing better voltage bias for SiPMs

Nowadays, Silicon photomultipliers (SiPM) become a reasonable choice for Time-of-Flight Positron Emission Tomography (TOF-PET). To achieve the best performance of SiPMs, it is necessary to adjust a suitable voltage bias. In this article, we are using varistors which protect SiPM from voltage fluctuations. The silicon-polymer composite varistors prepared using hot press method have been investigated. Research on (current-voltage) characteristics of samples shows that by increasing silicon content in the mixture, the breakdown voltage decreases from 110 V to 70 V. The results also show that increasing silicon content decreases the potential barrier height from 0.29 eV to 0.26 eV, however, leakage current increases. Increasing silicon content increases nonlinear coefficient from 4.1 to 4.8. Using these techniques gives us ability to produce suitable surge protector for medical imaging modalitie

The effects of vitamin D supplementation on indices of glycemic control in Iranian diabetics: A systematic review and meta-analysis

Background and purpose: This systematic review and meta-analysis aimed to assess the effects of vitamin D supplements on indices of glycemic control [homeostatic model assessment-insulin resistance (HOMA-IR), hemoglobin A1C (HbA1C), fasting blood glucose (FBG), and quantitative insulin-sensitivity check index (QUICKI) and lipid profile in diabetic patients. Methods: Eight databases were searched, for randomized controlled trials (RCTs) or cross-sectional and cohort studies that have been published up to December 2017. We used the comprehensive meta-analysis (CMA) software for all statistical analysis and used the I2 index for assessing heterogeneity. A p value of <0.05 was considered as statistically significant. Results: We found 621 articles, and after the exclusion of ineligible publications, 82 studies remained to be assessed of which 37 were used for meta-analysis. Vitamin D supplementation was associated with a significant improvement in FBG (p = 0.001 and 95% CI: −0.526 to −0.136) and HbA1C (p = 0.003 and 95% CI: 1.719 to −0.361) in individuals with type 2 diabetes mellitus (T2DM); while in women with gestational diabetes mellitus (GDM) the reduction in FBG (p = 0.071 and 95% CI: −0.873 to −0.035) and HbA1C (p = 0.199 and 95% CI: 3.270 to 0.681) failed to reach statistical significance. Treatment with vitamin D supplements was associated with an improvement in HOMA-IR in pregnant diabetic women (p = 0.028 and 95% CI: 0.924 to −0.053) and for individuals with diabetes mellitus (p = 0.005 and 95% CI: 1.772 to −0.319). The pooled result of the cross-sectional meta-analysis indicated that serum vitamin D concentrations were significantly lower in diabetic patients than in healthy controls (p = 0.018 and 95% CI: 0.587 to −0.054). Conclusion: This meta-analysis suggests that vitamin D supplementation improves indices of glycemic control (FBG, HOMA-IR, and HbA1C) in patients with diabetes mellitus. Hence, vitamin D supplements may be of potential therapeutic value in diabetic patients, as an adjuvant therapy along with other treatment

Feasibility studies for imaging e+^{+}e−^{-} annihilation with modular multi-strip detectors

Studies based on imaging the annihilation of the electron (e$^{-}$) and its antiparticle positron (e$^{+}$) open up several interesting applications in nuclear medicine and fundamental research. The annihilation process involves both the direct conversion of e$^{+}$e$^{-}$ into photons and the formation of their atomically bound state, the positronium atom (Ps), which can be used as a probe for fundamental studies. With the ability to produce large quantities of Ps, manipulate them in long-lived Ps states, and image their annihilations after a free fall or after passing through atomic interferometers, this purely leptonic antimatter system can be used to perform inertial sensing studies in view of a direct test of Einstein equivalence principle. It is envisioned that modular multistrip detectors can be exploited as potential detection units for this kind of studies. In this work, we report the results of the first feasibility study performed on a e$^{+}$ beamline using two detection modules to evaluate their reconstruction performance and spatial resolution for imaging e$^{+}$e$^{-}$ annihilations and thus their applicability for gravitational studies of Ps

High dose vitamin D supplementation can improve menstrual problems, dysmenorrhea and premenstrual syndrome in adolescents

Vitamin D has a crucial role in female reproduction, possibly through its effects on calcium homeostasis, cyclic sex steroid hormone fluctuations, or neurotransmitter function. We have assessed the effects of vitamin D supplementation on dysmenorrhea and premenstrual syndrome (PMS) in adolescents. In this study, 897 adolescent girls living in Mashhad and Sabzevar, Iran, received 9 high-dose vitamin D supplements (as 50000 IU/ week of cholecalciferol) and were followed up over 9 weeks. We evaluated the effect of vitamin D supplementation on individuals in 4 categories: those with only PMS; individuals with only dysmenorrhea; subjects with both PMS and dysmenorrhea and normal subjects. The prevalence of PMS after the intervention fell from 14.9% to 4.8% (P<0.001). Similar results were also found for the prevalence of subjects with dysmenorrhea (35.9% reduced to 32.4%), and in subjects with both PMS and dysmenorrhea (32.7% reduced 25.7%). Vitamin D supplementation was associated with a reduction in the incidence of several symptoms of PMS such as backache and tendency to cry easily as well decrement in pain severity of dysmenorrhea (P<0.05). High dose vitamin D supplementation can reduced the prevalence of PMS and dysmenorrhea as well has positive effects on the physical and psychological symptoms of PMS

Progress towards Every Newborn Action Plan (ENAP) implementation in Iran: obstacles and bottlenecks

Background: Neonatal mortality accounts for more than 47 of deaths among children under five globally but proper care at and around the time of birth could prevent about two-thirds of these deaths. The Every Newborn Action Plan (ENAP) offers a plan and vision to improve and achieve equitable and high-quality care for mothers and newborns. We applied the bottleneck analysis tool offered by ENAP to identify obstacles and bottlenecks hindering the scale-up of newborn care across seven health system building blocks. Methods: We applied the every newborn bottleneck analysis tool to identify obstacles hindering the scale-up of newborn care across seven health system building blocks. We used qualitative methods to collect data from five medical universities and their corresponding hospitals in three provinces. We also interviewed other national experts, key informants, and stakeholders in neonatal care. In addition, we reviewed and qualitatively analyzed the performance report of neonatal care and services from 16 medical universities around the country. Results: We identified many challenges and bottlenecks in the scale-up of newborn care in Iran. The major obstacles included but were not limited to the lack of a single leading and governing entity for newborn care, insufficient financial resources for neonatal care services, insufficient number of skilled health professionals, and inadequate patient transfer. Conclusions: To address identified bottlenecks in neonatal health care in Iran, some of our recommendations were as follows: establishing a single national authorizing and leading entity, allocating specific budget to newborn care, matching high-quality neonatal health care providers to the needs of all urban and rural areas, maintaining clear policies on the distribution of NICUs to minimize the need for patient transfer, and using the available and reliable private sector NICU ambulances for safe patient transfer. © 2021, The Author(s)

Hookah smoking is strongly associated with diabetes mellitus, metabolic syndrome and obesity: a population-based study

Objectives The adverse effects of cigarette smoking have been widely studied before, whilst the effects of hookah smoking has received less attention, although it is a common habit in the Middle East. Here we have investigated the effects of cigarette and hookah smoking on biochemical characteristics in a representative population sample derived from the Mashhad stroke and heart atherosclerotic disorder (MASHAD) cohort study, from Northeastern Iran. Study design A total of 9840 subjects from the MASHAD population study were allocated to five groups; non-smokers (6742), ex-smokers (976), cigarette smokers (864), hookah smokers (1067), concomitant cigarette and hookah smokers (41). Methods Baseline characteristics were recorded in a questionnaire. Biochemical characteristics were measured by routine methods. Data were analyzed using SPSS software and p < 0.05 was considered significant. Results After adjustment for age and sex; the presence of CVD, obesity, metabolic syndrome, DM and dyslipidemia were significantly (p < 0.001) related to smoking status. After multivariate analysis, HDL (p < 0.001), WBC (p < 0.001), MCV (p < 0.05), PLT (p < 0.01) and RDW (p < 0.001), and the presence of CVD (p < 0.01), obesity (p < 0.001), metabolic syndrome (p < 0.05) and DM (p < 0.01) remained significant between cigarette smokers and non-smokers. Between hookah smokers and non-smokers; uric acid (p < 0.001), PLT (p < 0.05) and RDW (p < 0.05), and the presence of obesity (p < 0.01), metabolic syndrome (p < 0.001), diabetes (p < 0.01) and dyslipidemia (p < 0.01) remained significant after logistic regression. Conclusion There was a positive association between hookah smoking and metabolic syndrome, diabetes, obesity and dyslipidemia which was not established in cigarette smoking

Prediction of leak flow rate in plastic water distribution pipes using vibro-acoustic measurements

Leakage from water distribution systems is a worldwide issue with consequences including loss of revenue, health and environmental concerns. Leaks have typically been found through leak noise correlation by placing sensors either side of the leak and recording and analysing its vibro-acoustic emission. While this method is widely used to identify the location of the leak, the sensors also record data that could be related to the leak’s flow rate, yet no reliable method exists to predict leak flow rate in water distribution pipes using vibro-acoustic emission. The aim of this research is to predict leak flow rate in medium-density polyethylene pipe using vibro-acoustic emission signals. A novel experimental methodology is presented whereby circular holes of four sizes are tested at several leak flow rates. Following the derivation of a number of features, least squares support vector machines are used in order to predict leak flow rate. The results show a strong correlation highlighting the potential of this technique as a rapid and practical tool for water companies to assess and prioritise leak repair

Testing CPT symmetry in ortho-positronium decays with positronium annihilation tomography

Charged lepton system symmetry under combined charge, parity, and time-reversal transformation (CPT) remains scarcely tested. Despite stringent quantum-electrodynamic limits, discrepancies in predictions for the electron–positron bound state (positronium atom) motivate further investigation, including fundamental symmetry tests. While CPT noninvariance effects could be manifested in non-vanishing angular correlations between final-state photons and spin of annihilating positronium, measurements were previously limited by knowledge of the latter. Here, we demonstrate tomographic reconstruction techniques applied to three-photon annihilations of ortho-positronium atoms to estimate their spin polarisation without magnetic field or polarised positronium source. We use a plastic-scintillator-based positron-emission-tomography scanner to record ortho-positronium (o-Ps) annihilations with single-event estimation of o-Ps spin and determine the complete spectrum of an angular correlation operator sensitive to CPT-violating effects. We find no violation at the precision level of 10−4, with an over threefold improvement on the previous measurement

From tests of discrete symmetries to medical imaging with J-PET detector

We present results on CPT symmetry tests in decays of positronium performed with the precision at the level of 10$^{-4}$, and positronium images determined with the prototype of the J-PET tomograph. The first full-scale prototype apparatus consists of 192 plastic scintillator strips readout from both ends with vacuum tube photomultipliers. Signals produced by photomultipliers are probed in the amplitude domain and are digitized by FPGA-based readout boards in triggerless mode. In this contribution we report on the first two- and three-photon positronium images and tests of CPT symmetry in positronium decays