The Influence of Inclined Barriers on Airflow Over a High Speed Train under Crosswind Condition

During the last decade the problem of crosswind has developed into an important subject amongst the topics in railway engineering. When high speed trains are exposed to extreme weather conditions such as intense lateral winds, storms and tornadoes, lateral loads acting on the train can cause overturning of the train. This present work analyzed the aerodynamic mechanism of a high-speed train with and without two inclined barriers. A three-dimensional numerical model of a train-barrier-crosswind system is adopted to investigate the effects of inclined angles of barriers on the flow patterns and the aerodynamic coefficients. This perusal surveys the design criteria indispensable for barriers that are installed alongside the tracks to protect the passing trains under strong side winds. By using a numerical code based on Lattice Boltzmann Method (LBM) it is attempted to initially investigate the behavior of airflow behind the barriers. Finally, it is found that the presence of the barriers has a great impact on decreasing the intensity of the air flow above the train. This study’s findings could be utilized as a reference for practical usage of barriers in railway transportation

Stochastic Approach to a Rain Attenuation Time Series Synthesizer for Heavy Rain Regions

In this work, a new rain attenuation time series synthesizer based on the stochastic approach is presented. The model combines a well-known interest-rate prediction model in finance namely the Cox-Ingersoll-Ross (CIR) model, and a stochastic differential equation approach to generate a long-term gamma distributed rain attenuation time series, particularly appropriate for heavy rain regions. The model parameters were derived from maximum-likelihood estimation (MLE) and Ordinary Least Square (OLS) methods. The predicted statistics from the CIR model with the OLS method are in good agreement with the measurement data collected in equatorial Malaysia while the MLE method overestimated the result. The proposed stochastic model could provide radio engineers an alternative solution for the design of propagation impairment mitigation techniques (PIMTs) to improve the Quality of Service (QoS) of wireless communication systems such as 5G propagation channel, in particular in heavy rain regions

Minimalnie inwazyjna paratyroidektomia pod kontrolą obrazowania radioizotopowego — porównanie niskich i wysokich dawek Tc-99m-MIBI

Introduction: Surgery remains the most effective treatment for primary hyperparathyroidism (PHPT). Minimally invasive radioguided parathyroidectomy (MIRP) is a common technique for detecting and excising abnormal parathyroid glands. The aim of this study was to compare injections of low-dose and high-dose (99m) Tc methoxy isobutyl isonitrile (MIBI) for intraoperative localisation of parathyroid adenomas by means of a gamma probe in patients with primary hyperparathyroidism (PHPT). Material and methods: Thirty patients with PHPT and a preoperative diagnosis of parathyroid adenoma were enrolled between 2010 and 2012. They were considered as Group B and underwent MIRP using 5 mCi Tc-99m MIBI, and their perioperative data were compared with twenty patients treated with conventional 20 mCi Tc-99m MIBI previously (Group A). Results: Group A was made up of 20 patients (mean age, 41.55 years; 14 women and 6 men), and group B included 30 patients (mean age, 40.43 years; 19 women and 11 men). The mean serum parathyroid hormone (PTH) and calcium values were recorded pre- and postoperatively. The mean follow-up period for the patients in the two groups was 18.4 and 16.5 months, respectively. Pre-operative evaluation demonstrated that the groups were statistically similar. Intraoperative data and success rate of surgery showed no difference between the two groups. No significant complication was detected after surgeries and no recurrence happened in either of the two groups during the follow-up period. Conclusions: A new protocol of MIRP using low doses of Tc-99m-MIBI resulted in an excellent success rate. Comparing results of the study, we conclude that low-dose Tc-99m-MIBI may be preferred for identification of parathyroid adenomas intraoperatively by means of a gamma probe in PHPT patients because it appears to be as effective as high-dose Tc-99m-MIBI.Wstęp: Najbardziej skutecznym leczeniem pierwotnej nadczynności przytarczyc (PHPT, primary hyperparathyroidism) nadal pozostaje zabieg chirurgiczny. Minimalnie inwazyjna paratyroidektomia z lokalizacją radioizotopową (MIRP, minimally invasive radioguided parathyroidectomy) jest techniką często stosowaną do wykrywania i wycinania nieprawidłowych przytarczyc. Badanie przeprowadzono w celu porównania małej i dużej dawki (99m) Tc metoksy-izobutylu-izonitrylu (MIBI) podawanych w celu śródoperacyjnej lokalizacji gruczolaków przytarczyc za pomocą sondy gamma u chorych z pierwotną nadczynnością przytarczyc (PHPT, primary hyperparathyroidism). Materiał i metody: W latach 2010–2012 do badania włączono 30 chorych z PHPT i przedoperacyjnym rozpoznaniem gruczolaka przytarczyc. W tej grupie chorych określonej jako grupa B wykonano MIRP po podaniu 5 mCi Tc-99m MIBI, a dane okołooperacyjne tych chorych porównano z danymi 20 pacjentów, u których zastosowano konwencjonalną dawkę 20 mCi Tc-99m MIBI (grupa A). Wyniki: Grupa A składała się z 20 chorych (średnia wieku 41,55 r.; 14 kobiet i 6 mężczyzn), a grupę B tworzyło 30 chorych (średnia wieku 40,43 r.; 19 kobiet i 11 mężczyzn). Zmierzono przed- i pooperacyjne stężenia w surowicy parathormonu (PTH, pathyroid hormone) i wapnia. Średni okres obserwacji chorych w grupach A i B wynosił odpowiednio 18,4 i 16,5 miesiąca. Ocena przedoperacyjna wykazała, że grupy nie różniły się statystycznie między sobą. Również dane śródoperacyjne odsetek zabiegów zakończonych powodzeniem były podobne w obu grupach. W żadnej z grup nie stwierdzono istotnych powikłań pozabiegowych ani nawrotu w okresie obserwacji. Wnioski: Nowy protokół MIRP z użyciem małych dawek Tc-99m-MIBI wiązał się z bardzo wysokim odsetkiem pomyślnych zabiegów. Porównanie wyników uzyskanych w badaniu pozwala sformułować wniosek, że do śródoperacyjnego identyfikowania za pomocą sondy gamma gruczolaków nadnercza u chorych z PHPT mogą być preferowane małe dawki Tc-99m-MIBI, ponieważ są równie skuteczne jak duże dawki Tc-99m-MIBI

Perceived barriers to the production of scientific articles among faculty members of some of Iranian dental schools

Objectives To evaluate barriers for production of scientific dental articles by Iranian dental faculty members.Methods An anonymous self-administered questionnaire distributed among faculty members of all dental schools in Iran during June-December 2010. The respondents rated their level of agreement with eleven sentences regarding what they perceive as barriers on scientific dental article production based on a 5-point Likert scale. The data were analyzed using Chi-square test.Results Totally, 330 faculty members completed the questionnaires; >50% were men, and >40 year-olds. About three-fourth of the respondents were assistant professor. More than 80% of the respondents reported to have at least one published Persian article and >50% at least one published English article; older faculty members more than younger, and associate professors more than other academic ranks (p<0.01). “No access to an English editing center”, “insufficient skill for scientific writing in English”, “inappropriate condition for writing in dental school”, and “time limit due to high load of clinical work in dental school” were top four rated perceived barriers.Conclusion The concerns of faculty members for the production of scientific dental documents must be considered. Provision of proper time and condition for writing in the dental school, enhancement of their capacity for scientific writing and establishment of an English editing center in each university may facilitate scientific article production

Analysis of correlation between estradiol and fracture of femur neck

Osteoporosis is a major public health challenge all over the world. Estrogen hormone was cited amongst other hormones to be an efficient hormone for the production and maintenance of bone density. This study was designed with the purpose of evaluating and analyzing the estradiol effect on fractures of femur neck in the Iranian society. This study evaluated men over 50 years of age suffering with mild trauma (falling off the same level height or lower) and with a fracture on their femur neck. Also, their serum level of estradiol was measured with an ELISA method. Using this procedure, the patients were assigned into groups with either normal estradiol serum level (10pg/ml and higher) or with lower than normal level (lower than 10 pg/ml). A control group including 50-year-old and older men without hip fracture, or its history, was chosen to access their estradiol serum level. Data collected from these two groups were statistically compared. A total of 120 patients were evaluated (60 in the control and 60 in the test group). The mean age of patients in the control and test groups were 67.9±10.22 and 69.5±8.84 years, respectively (p=0.376). Smoker patients’ percentages in the control and test groups were 35% and 31.7%, respectively (p=0.699). On the basis of the serum estradiol level, patients’ percentages with low estradiol level in control and test groups were 10% and 16.7%, respectively (p=0.283). The only significant factor in predicting serum estradiol level was smoking. In conclusion, in this study it was observed that fractures of the femoral neck following a mild trauma were not correlated to low level of serum estradiol

Comparison of plasma mitochondrial DNA copy number in asymptomatic and symptomatic COVID-19 patients

IntroductionSince the beginning of the COVID-19 pandemic, a wide clinical spectrum, from asymptomatic infection to mild or severe disease and death, have been reported in COVID-19 patients. Studies have suggested several possible factors, which may affect the clinical outcome of COVID-19. A pro-inflammatory state and impaired antiviral response have been suggested as major contributing factors in severe COVID-19. Considering that mitochondria have an important role in regulating the immune responses to pathogens, pro-inflammatory signaling, and cell death, it has received much attention in SARS-CoV-2 infection. Recent studies have demonstrated that high levels of cell-free mitochondrial DNA (cf-mtDNA) are associated with an increased risk of COVID-19 intensive care unit (ICU) admission and mortality. However, there have been few studies on cf-mtDNA in SARS-CoV-2 infection, mainly focusing on critically ill COVID-19 cases. In the present study, we investigated cf-mtDNA copy number in COVID-19 patients and compared between asymptomatic and symptomatic cases, and assessed the clinical values. We also determined the cf-nuclear DNA (cf-nDNA) copy number and mitochondrial transcription factor A (TFAM) mRNA level in the studied groups.Materials and methodsPlasma and buffy coat samples were collected from 37 COVID-19 patients and 33 controls. Briefly, after total DNA extraction, plasma cf-mtDNA, and cf-nDNA copy numbers were measured by absolute qPCR using a standard curve method. Furthermore, after total RNA extraction from buffy coat and cDNA synthesis, TFAM mRNA levels were evaluated by qPCR.ResultsThe results showed that cf-mtDNA levels in asymptomatic COVID-19 patients were statistically significantly higher than in symptomatic cases (p value = 0.01). However, cf-nDNA levels were higher in symptomatic patients than in asymptomatic cases (p value = 0.00). There was no significant difference between TFAM levels in the buffy coat of these two groups (p value > 0.05). Also, cf-mtDNA levels showed good diagnostic potential in COVID-19 subgroups.Conclusioncf-mtDNA is probably important in the outcome of SARS-CoV-2 infection due to its role in inflammation and immune response. It can also be a promising candidate biomarker for the diagnosis of COVID-19 subgroups. Further investigation will help understanding the COVID-19 pathophysiology and effective diagnostic and therapeutic strategies

Comparison of the Response of the Right Ventricle with Endovascular Occlusion and Surgical Closure in Adults with Atrial Septal Defect One Year After Intervention

Background Use of the Amplatzer septal occluder (ASO) for the closure of secundum atrial septal defect (ASD) has recently become the procedure of choice, while earlier the only treatment for ASD was surgical closure. This study compares the right ventricular indices of the ASO group with the surgical closure group one year after intervention in adults. Methods From January 2008 to February 2010, 38 patients with isolated atrial septal defect of the secundum type one year after surgical (n = 20, age = 27 ± 4 years, 13 females, 7 males) or Amplatzer septal occluder closure (n = 18, age = 25 ± 4 years, 12 females, 6 males) were studied. At the same time, thirty-one age-matched normal subjects (age = 26 ± 6 years, 23 females, 9 males) were included as the control group. Strain and strain rate of the right ventricle were measured. Results The mean values of strain of the midportion were −26% ± 11.7%, −8.9% ± 4.2%, and 24.5% ± 7.4% ( P < 0.001). Strain rates of the midportion were −2.19 ± 0.6 s −1 , −1.2 ± 0.4 s −1 , −1.9 ± 0.6 s −1 ( P < 0.001) in ASO, surgery, and control groups, respectively. Conclusion This study showed that the right ventricle might show better performance in the ASO than the surgery group in adults with ASD in midterm follow-up

Survival probability of precipitations and rain attenuation in tropical and equatorial regions

This contribution presents a stochastic model useful for the generation of a long-term tropospheric rain attenuation time series for Earth space or a terrestrial radio link in tropical and equatorial heavy rain regions based on the well-known Cox-Ingersoll-Ross model previously employed in research in the fields of finance and economics. This model assumes typical gamma distribution for rain attenuation in heavy rain climatic regions and utilises the temporal dynamic of precipitation collected in equatorial Johor, Malaysia. Different formations of survival probability are also discussed. Furthermore, the correlation between these probabilities and the Markov process is determined, and information on the variance and autocorrelation function of rain events with respect to the particular characteristics of precipitation in this area is presented. The proposed technique proved to preserve the peculiarities of precipitation for an equatorial region and reproduce fairly good statistics of the rain attenuation correlation function that could help to improve the prediction of dynamic characteristics of rain fade events

The study of possible biotechniques and normative to production some species of Anostraca (Phallocryptus spinosa)

This project was carried out in order to determine the hatching conditions and laboratory culture methods of Fairy Shrimps (Phallocryptus spinosa). Physico- chemical factors and phytoplankton of natural habitat of this organism was investigated in Khasellou region around Azarshahr – East Azarbaijan province. The results showed that occurance and growth of fairy shrimps in their habitates were beginning from early Aprill and their survival was decreased with increasing temperature, precipitation and increasing the salinity of their culture medium. Then they disappeared. Their habitat phytoplankton contained 3 phylla and 10 genera, from which green algae enjoyed the greatest density in May. The pool salinity was around 20-17 g/l, when metanauplii was observed in early spring. In the pool containing and without fairy shrimps the oxygen concentration was high (9 mg/l) and low (2.9 mg/l), respectively. In 9 prawn ornamental fish genera, feeding with fairy shrimp showed a significant higher fecundity and hatching percentage compared to manual diets (cow liver, spinach). In all groups fed with fairy shrimp the duration of spawning time were reduced from 15 to 8-10 days and the color was enhanced. The means of cyst number per captured female also, cyst, decapsulated cyst and Naupilli diameters were mesured 142.9±19.0 cysts, 273.2±4.9µ, 242.4±3.8µ and 542.6±27.0 µ, respectively. The hatching rate was increased by reducing temperature and salinity of their culture mediums from 25 to 15 ◦C , and 28 to 18 g/l, respectively. The highest hatching was observed on 5th day at 15 ◦C and 18 g/l (5, 33 %). In addition, low but multiple hatching was observed. Therefore, water temperature and salinity affected hatching rate in this species. The hatching success of Phallocryptus spinosa cysts was better when collecting cysts together with dry sediments of their habitat without separation sensitive cysts. In addition to cold keeping and freezing, the hydration – dehydration method caused more diapause deactivation for hatching induction. The laboratory results revealed that the survival of fairy shrimps were highest at 15 ◦C (42%) and lowest at 25◦C (26%), respectively. Also, their life was inhibited in 30◦C. In different salinities, the mean survival rate were 26% (Salinity= 15 g/l) and 20% (Salinity= 25 g/l), respectively. The mean survival percentage of Phallocryptus spinosa cultured in natural habitat water (64.3%) was higher than aerated tap water (23, 3 %). Also, feeding with Nanochlorepsis caused higher survival rates. On the other hand, Beakers yeast caused higher mortality rates. Therefore, regarding to relatively high sensitivity of these species to physico– chemical and nutritional conditions of their culture medium, it is better to culture these species with expansion of their natural habitat in order to preserve their biodiversity, culture and increase stocking density with regard to environmental considerations