Structural and energy properties of interstitial molecular hydrogen in single-crystal silicon

The structural and energy characteristics of interstitial molecular hydrogen in single-crystal silicon are theoretically studied. The dependence of the potential energy of the system on the position and orientation of the interstitial defect is investigated, and the mechanism of interaction of a hydrogen molecule with a silicon crystal is considered. A three-dimensional model is employed to calculate the energy spectrum of H2 in Si, and the obtained dispersion law is analyzed

Investigation of Hollow and Dense Droplet Impact on Solid Surfaces

Droplet impact and its flattening on a surface play an essential role in many industrial applications such as inkjet printing, agriculture, and plasma spraying. Understanding the physics of droplet spreading is the key to maintaining the mass transfer process in all relevant applications. Two different problems are investigated in this study. In the first parts, the behavior of a hollow droplet after impact on a surface is considered, while in the last chapter, the effect of gas desorption on the flattening and solidification of a molten particle in investigated. Most of the droplets observed in nature are dense droplets. Nevertheless, special droplets have been observed in several industrial applications such as aerosol transfer from the sea, oxygen dissolution, controllable biomedicine, and thermal spray coating which are called hollow droplets. In plasma spraying process, the accumulation of these flatten droplets (splats) on top of each other forms a coated layer. Due to their embedded medium, the cavity-containing droplets (hollow droplets) trigger cavitation when they reach the target and influence the splat properties by releasing the inner substance. However, it is difficult to study the impact and flattening of hollow droplets in thermal spraying, regarding the harsh environments, and phenomena small size and high velocity. To better understand the flattening process of a hollow droplet, in this work, a comprehensive experimental, numerical, and theoretical study is performed on water and glycerol droplets impacting on a rigid surface. The experiments are repeated on different surfaces, including aluminum, sand-blasted steel, and superhydrophobic. The results show that the mechanisms of the post-impact process of hollow droplets are different from those of dense droplets in several aspects. We study the role of surface wettability, liquid properties, impact velocity, surface angle, and bubble size and location on the droplet flattening process. In the numerical part, compressible Navier-Stokes equations are solved using the volume of fluid (VOF) method. A theoretical model is developed to analyze the maximum spreading diameter of the hollow droplet impact analytically. Its prediction is in good agreement with the experimental and numerical results. The comparison of simulation results with the experimental photographs shows that the numerical solver can correctly predict the hollow droplet shape evolution. It is demonstrated that flattening a hollow droplet has two significant distinctions compared to a dense droplet flattening. The first distinction is the formation of a counter-jet following the collision of a hollow droplet impact perpendicular to the surface. It is proven that the formation of the counter-jet is an inherent phenomenon of hollow droplet flattening and is unaffected by impact velocity or substrate angle. Nevertheless, it is revealed that the counter-jet length depends on droplet velocity or liquid viscosity. The second distinction is the ultimate shape of the flattened droplet. After contact on a hydrophobic surface, the dense droplet partially recoils toward the center and produces a dome shape. However, upon impact on a hydrophobic surface, the hollow droplet takes the form of a donut. This is owing to the perturbations caused by bubble rupture on the spreading droplet surface. As a result of these perturbations, the spreading liquid sheet is fragmented and, the droplet is unable to recoil toward the center, forming a donut shape. The results show that the spreading diameter and the counter-jet height formed after the hollow droplet impact grows with impact velocity increasing. Investigating the size and location of the entrapped bubble shows an optimum bubble size that facilitates the hollow droplet flattening. It is also demonstrated that the ripples on splats produced by the hollow droplets with a larger bubble size are higher than those of small bubbles. In the end, the effects of surface gas desorption on the splat formation are studied. In plasma spray, the splats resulting from the impact, spreading, and solidification of molten particles are the building blocks of the spray coatings. Fragmented splats are formed on substrates held at room temperature and atmospheric pressure. Although the formation of a fragmented splat is attributed to adsorbates on the substrate surface, its dynamics have not been adequately addressed. In this study, a numerical model is developed to investigate the formation of fragmented splats during droplet flattening and solidification in plasma spraying conditions. Compressible Navier—Stokes equations are solved, and the volume of fluid (VOF) method is used to capture the liquid and gas interface. In addition, the source term method is used to capture the solidification process during droplet flattening. Moreover, a new boundary condition is defined to consider the effect of gas desorption on the substrate surface after droplet impact. The numerical results show that gas desorption from the surface produces a barrier layer between the droplet and the substrate. This high-pressure region detaches the edge of the spreading droplet from the surface and forms a liquid sheet. The liquid sheet rises above the substrate and spreads up to 2 times more than droplets impacting surfaces without gas desorption. The fragmentation of the liquid film follows the overspreading of the droplet. As a result, only a portion of the initial droplet remains at the location of the impact, which forms a small solidified splat

Joint Sum Rate And Error Probability Optimization: Finite Blocklength Analysis

We study the tradeoff between the sum rate and the error probability in downlink of wireless networks. Using the recent results on the achievable rates of finite-length codewords, the problem is cast as a joint optimization of the network sum rate and the per-user error probability. Moreover, we develop an efficient algorithm based on the divide-and-conquer technique to simultaneously maximize the network sum rate and minimize the maximum users' error probability and to evaluate the effect of the codewords length on the system performance. The results show that, in delay-constrained scenarios, optimizing the per-user error probability plays a key role in achieving high throughput.Comment: Accepted for publication in IEEE Wireless Communications Letter

Customized Lateral Nasal Osteotomy Guide: Three-Dimensional Printer Assisted Fabrication

Lateral osteotomy is a necessity in several rhinoplasty cases. However, it can be challenging for inexperienced surgeons to perform external osteotomy due to difficulties such as lack of control, inconsistent results and technical complications. The present article presents a simplified approach for external lateral nasal osteotomy by using a customized lateral nasal osteotomy guide fabricated with three-dimensional printer. This technique may assist novice surgeons to perform external lateral nasal osteotomy more safely and with reduced operation time and consistent outcomes

Adaptive Natural Oscillator to Exploit Natural Dynamics for Energy Efficiency

We present a novel adaptive oscillator, called Adaptive Natural Oscillator (ANO), to exploit the natural dynamics of a given robotic system. This tool is built upon the Adaptive Frequency Oscillator (AFO), and it can be used as a pattern generator in robotic applications such as locomotion systems. In contrast to AFO, that adapts to the frequency of an external signal, ANO adapts the frequency of reference trajectory to the natural dynamics of the given system. In this work, we prove that, in linear systems, ANO converges to the system's natural frequency. Furthermore, we show that this tool exploits the natural dynamics for energy efficiency through minimization of actuator effort. This property makes ANO an appealing tool for energy consumption reduction in cyclic tasks; especially in legged systems. We also extend the proposed adaptation mechanism to high dimensional and general cases; such as n-DOF manipulators. In addition, by investigating a hopper leg in simulation, we show the efficacy of ANO in face of dynamical discontinuities; such as those inherent in legged locomotion. Furthermore, we apply ANO to a simulated compliant robotic manipulator performing a periodic task where the energy consumption is drastically reduced. Finally, the experimental results on a 1-DOF compliant joint show that our adaptive oscillator, despite all practical uncertainties and deviations from theoretical models, exploits the natural dynamics and reduces the energy consumption

Diagnostic Accuracy of Ultrasonography in Diagnosis of Metatarsal Bone Fracture; a Cross Sectional Study

Introduction: Metatarsus is one of the most common sites in the sole of foot bones fractures. The aim of this study was to determine the diagnostic accuracy of ultrasound in diagnosis of metatarsal bone fractures following foot trauma. Methods: This cross-sectional study was carried out on patients with blunt foot trauma admitted to emergency department of a hospital in Mashhad, Iran from January to September 2016. All patients were evaluated with bedside ultrasound for the presence of first to fifth metatarsal fractures and screening performance characteristics of ultrasonography in detection of metatarsal fractures were calculated considering foot radiography as the reference test. Results: The study was conducted on 102 patients with a mean age of 35.14±14.32 years (56.8% male). The most common signs of trauma in physical examination were pain and tenderness (100%), swelling (96.1%), ecchymosis (14.7%) and deformity (1.9%). Sensitivity, specificity, and positive and negative likelihood ratio of ultrasonography in detection of metatarsal bone fracture were 96.7% (95% CI: 0.83-0.99), 84.5% (95% CI: 0.73-0.92), 73.1% (95% CI: 0.57-0.85), and 98.3% (95% CI: 0.91-0.99), respectively. The overall accuracy of ultrasonography was 0.906 (95% CI: 0.844 – 0.969) based on area under the receiver operating characteristic (ROC) curve. Conclusion: Considering the excellent diagnostic accuracy, ultrasonography can be used as an alternative means in diagnosis of metatarsal bone fractures

Improving Fraud and Abuse Detection in General Physician Claims: A Data Mining Study

Background: We aimed to identify the indicators of healthcare fraud and abuse in general physicians’ drug prescription claims, and to identify a subset of general physicians that were more likely to have committed fraud and abuse. Methods: We applied data mining approach to a major health insurance organization dataset of private sector general physicians’ prescription claims. It involved 5 steps: clarifying the nature of the problem and objectives, data preparation, indicator identification and selection, cluster analysis to identify suspect physicians, and discriminant analysis to assess the validity of the clustering approach. Results: Thirteen indicators were developed in total. Over half of the general physicians (54%) were ‘suspects’ of conducting abusive behavior. The results also identified 2% of physicians as suspects of fraud. Discriminant analysis suggested that the indicators demonstrated adequate performance in the detection of physicians who were suspect of perpetrating fraud (98%) and abuse (85%) in a new sample of data. Conclusion: Our data mining approach will help health insurance organizations in low-and middle-income countries (LMICs) in streamlining auditing approaches towards the suspect groups rather than routine auditing of all physician

A genetic polymorphism in the CYP1B1 gene in patients with squamous cell carcinoma of the esophagus: an Iranian Mashhad cohort study recruited over 10 years

Background: Esophageal-cancer is the seventh most common-cause of cancer-related-deaths in men. Cytochrome-P450-family-1-subfamily-B-polypeptide-1 (CYP1B1) plays a role in the metabolism of xenobiotics, and is associated with several cancers. Here we investigated the association between a genetic-variant, CYP1B1-rs1056836, with the clinical-characteristics of patients with esophagus-squamous-cell-carcinoma (ESCC). Method: 117-patients with ESCC and 208 healthy-subjects were recruited. DNA was extracted and genotyped. Kaplan-Meier curves were utilized to assess overall and progression-free survival. The relationship between clinicopathological-data, disease-prognosis, and survival, were evaluated with the genotypes. Results: the genotypic frequency for GG, GC, and CC were 58.6%, 29.8%, 11.5% respectively in the healthy subjects and 51.8%, 36.14% and 12% in the ESCC group. An association between the GG genotype and stage of ESCC was found. Conclusion: Our findings suggest a relationship between the CYP1B1-rs1056836 genetic polymorphism and clinical features of ESCC, supporting further studies in larger-populations in different-ethnic groups, taking into account potentially important environmental-factors

Intraperitoneal administration of Telmisartan prevents postsurgical adhesion band formation

Background Angiotensin II receptor blockers (ARBs) have a potential role in reducing inflammation and fibrosis. We have integrated systems and molecular biology approaches to investigate the therapeutic potential of ARBs in preventing postsurgical adhesion band formation. Material and methods we have followed the ARRIVE guidelines point by point during experimental studies. Telmisartan (1 and 9 mg/kg), valsartan (1 and 9 mg/kg), and losartan (1 and 10 mg/kg) were administered intraperitoneally in different groups of male albino Wistar rat. After 7 d of treatment, macroscopic evidence and score of fibrotic bands based on scaling methods was performed. Moreover, the anti-inflammatory and antifibrosis effects of telmisartan on reduction of fibrotic bands were investigated by using histopathology, ELISA, and real-time polymerase chain reaction methods. Results Telmisartan, but not losartan or valsartan, prevented the frequency as well as the stability of adhesion bands. Telmisartan appears to elicit anti-inflammatory responses by attenuating submucosal edema, suppressing proinflammatory cytokines, decreasing proinflammatory cell infiltration, and inhibiting oxidative stress at the site of peritoneal surgery. We also showed that telmisartan prevents fibrotic adhesion band formation by reducing excessive collagen deposition and suppression of profibrotic genes expression at the peritoneum adhesion tissues. Conclusions These results support the potential application of telmisartan in preventing postsurgical adhesion band formation by inhibiting key pathologic responses of inflammation and fibrosis in postsurgery patients

Global, regional, and national cancer incidence, mortality, years of life lost, years lived with disability, and disability-Adjusted life-years for 29 cancer groups, 1990 to 2017 : A systematic analysis for the global burden of disease study

Importance: Cancer and other noncommunicable diseases (NCDs) are now widely recognized as a threat to global development. The latest United Nations high-level meeting on NCDs reaffirmed this observation and also highlighted the slow progress in meeting the 2011 Political Declaration on the Prevention and Control of Noncommunicable Diseases and the third Sustainable Development Goal. Lack of situational analyses, priority setting, and budgeting have been identified as major obstacles in achieving these goals. All of these have in common that they require information on the local cancer epidemiology. The Global Burden of Disease (GBD) study is uniquely poised to provide these crucial data. Objective: To describe cancer burden for 29 cancer groups in 195 countries from 1990 through 2017 to provide data needed for cancer control planning. Evidence Review: We used the GBD study estimation methods to describe cancer incidence, mortality, years lived with disability, years of life lost, and disability-Adjusted life-years (DALYs). Results are presented at the national level as well as by Socio-demographic Index (SDI), a composite indicator of income, educational attainment, and total fertility rate. We also analyzed the influence of the epidemiological vs the demographic transition on cancer incidence. Findings: In 2017, there were 24.5 million incident cancer cases worldwide (16.8 million without nonmelanoma skin cancer [NMSC]) and 9.6 million cancer deaths. The majority of cancer DALYs came from years of life lost (97%), and only 3% came from years lived with disability. The odds of developing cancer were the lowest in the low SDI quintile (1 in 7) and the highest in the high SDI quintile (1 in 2) for both sexes. In 2017, the most common incident cancers in men were NMSC (4.3 million incident cases); tracheal, bronchus, and lung (TBL) cancer (1.5 million incident cases); and prostate cancer (1.3 million incident cases). The most common causes of cancer deaths and DALYs for men were TBL cancer (1.3 million deaths and 28.4 million DALYs), liver cancer (572000 deaths and 15.2 million DALYs), and stomach cancer (542000 deaths and 12.2 million DALYs). For women in 2017, the most common incident cancers were NMSC (3.3 million incident cases), breast cancer (1.9 million incident cases), and colorectal cancer (819000 incident cases). The leading causes of cancer deaths and DALYs for women were breast cancer (601000 deaths and 17.4 million DALYs), TBL cancer (596000 deaths and 12.6 million DALYs), and colorectal cancer (414000 deaths and 8.3 million DALYs). Conclusions and Relevance: The national epidemiological profiles of cancer burden in the GBD study show large heterogeneities, which are a reflection of different exposures to risk factors, economic settings, lifestyles, and access to care and screening. The GBD study can be used by policy makers and other stakeholders to develop and improve national and local cancer control in order to achieve the global targets and improve equity in cancer care. © 2019 American Medical Association. All rights reserved.Peer reviewe