Strukturna i elektronska svojstva bbc selena pod visokim tlakom

Full-potential linearized augmented plane-wave method (FP-LAPW) within the density functional theory is applied to study the structural and electronic properties of selenium in the bcc phase at high pressures. We used local density approximation with and without generalized gradient correction based on exchange-correlation energy optimization. We have determined the full set of first-order elastic constants, which have not been established earlier experimentally or theoretically. The elastic moduli show linear dependence on pressure. The calculated energy allowed us to investigate several structural properties such as lattice parameter, bulk modulus and its pressure derivative. Our calculated lattice parameter is found to be in reasonable agreement with experimental result. The electronic band structure and the density of states at various pressures are also calculated to show that there is a possibility for these compounds to become metallic at high pressures. Further, we have calculated the electronic specific heat coefficient, which decreases with the increase of pressure.Primjenom metode lineariziranih proširenih ravnih valova s potpunim potencijalom, u okviru teorije funkcionala gustoće, proučavali smo strukturna i elektronska svojstva selena u bcc fazi na visokim tlakovima. Primijenili smo približenje lokalne gustoće sa i bez poopćene gradijentne popravke primjenom optimizacije energije korelacije i izmjene. Odredili smo potpun skup elestičnih konstanti prvog reda koje ranije nisu bile određene ni eksperimentalno ni teorijski. Moduli eleastičnosti pokazuju linearnu ovisnost o tlaku. Na osnovi izračunatih energija mogli smo istražiti više strukturnih svojstava, kao što su parametar rešetke, volumni modul stlačivosti i njegova derivacija po tlaku. Naš izračunat parametar rešetke je u dobrom slaganju s eksperimentalnim rezultatom. Također smo izračunali strukturu elekronskih vrpci i gustoće stanja da bismo ukazali na mogućnost da na visokim tlakovima selen u fazi bcc može postati metal. Nadalje, izračunali smo koeficijent elektronske specifične topline koji se smanjuje s porastom tlaka

THE IMPACT OF TRUS IN DETECTION OF PROSTATE CANCER IN GEZIRA, SUDAN

Introduction:  Prostate cancer (P ca) is the most commonly diagnosed visceral cancer worldwide. It is the second cause of cancer death in men. Objective: To study the impact of introducing transrectal ultrasound (TRUS)-guided biopsy in detection of Prostate cancer in Central Sudan. Methods: This was a retrospective hospital based study. A review was done for data of prostate cancer patients treated in the Institute of Nuclear Medicine and Oncology & Gezira Hospital of Renal Diseases & Surgery (GHRD&S), Wad Medani, Sudan during the years 2002-2007. Comparison was done between the data available before and after introduction of trans rectal ultrasound biopsy, TRUS in 2005. Results: Prostate cancer cases were contributing for only 8% of all cancers during the time period before TRUS introduction. During the year 2007 the figure increased to 14%. The leading cancer in males now is the P ca. previously it was the third registered cancer before TRUS was introduced. The detection of new cases per year increased dramatically after the introduction of TRUS service. Conclusion and recommendation: Prostate cancer was found to be the most common cancer in Sudanese males. TRUS guided biopsy contributed significantly in early detection of prostate cancer in this region. Distribution of this facility with adequate training of the staff optimizes a proper and early detection of prostate cancer

The interplay between tissue growth and scaffold degradation in engineered tissue constructs

In vitro tissue engineering is emerging as a potential tool to meet the high demand for replacement tissue, caused by the increased incidence of tissue degeneration and damage. A key challenge in this field is ensuring that the mechanical properties of the engineered tissue are appropriate for the in vivo environment. Achieving this goal will require detailed understanding of the interplay between cell proliferation, extracellular matrix (ECM) deposition and scaffold degradation.\ud \ud In this paper, we use a mathematical model (based upon a multiphase continuum framework) to investigate the interplay between tissue growth and scaffold degradation during tissue construct evolution in vitro. Our model accommodates a cell population and culture medium, modelled as viscous fluids, together with a porous scaffold and ECM deposited by the cells, represented as rigid porous materials. We focus on tissue growth within a perfusion bioreactor system, and investigate how the predicted tissue composition is altered under the influence of (i) differential interactions between cells and the supporting scaffold and their associated ECM, (ii) scaffold degradation, and (iii) mechanotransduction-regulated cell proliferation and ECM deposition.\ud \ud Numerical simulation of the model equations reveals that scaffold heterogeneity typical of that obtained from μCT scans of tissue engineering scaffolds can lead to significant variation in the flow-induced mechanical stimuli experienced by cells seeded in the scaffold. This leads to strong heterogeneity in the deposition of ECM. Furthermore, preferential adherence of cells to the ECM in favour of the artificial scaffold appears to have no significant influence on the eventual construct composition; adherence of cells to these supporting structures does, however, lead to cell and ECM distributions which mimic and exaggerate the heterogeneity of the underlying scaffold. Such phenomena have important ramifications for the mechanical integrity of engineered tissue constructs and their suitability for implantation in vivo

Strukturna i elektronska svojstva bbc selena pod visokim tlakom

Full-potential linearized augmented plane-wave method (FP-LAPW) within the density functional theory is applied to study the structural and electronic properties of selenium in the bcc phase at high pressures. We used local density approximation with and without generalized gradient correction based on exchange-correlation energy optimization. We have determined the full set of first-order elastic constants, which have not been established earlier experimentally or theoretically. The elastic moduli show linear dependence on pressure. The calculated energy allowed us to investigate several structural properties such as lattice parameter, bulk modulus and its pressure derivative. Our calculated lattice parameter is found to be in reasonable agreement with experimental result. The electronic band structure and the density of states at various pressures are also calculated to show that there is a possibility for these compounds to become metallic at high pressures. Further, we have calculated the electronic specific heat coefficient, which decreases with the increase of pressure.Primjenom metode lineariziranih proširenih ravnih valova s potpunim potencijalom, u okviru teorije funkcionala gustoće, proučavali smo strukturna i elektronska svojstva selena u bcc fazi na visokim tlakovima. Primijenili smo približenje lokalne gustoće sa i bez poopćene gradijentne popravke primjenom optimizacije energije korelacije i izmjene. Odredili smo potpun skup elestičnih konstanti prvog reda koje ranije nisu bile određene ni eksperimentalno ni teorijski. Moduli eleastičnosti pokazuju linearnu ovisnost o tlaku. Na osnovi izračunatih energija mogli smo istražiti više strukturnih svojstava, kao što su parametar rešetke, volumni modul stlačivosti i njegova derivacija po tlaku. Naš izračunat parametar rešetke je u dobrom slaganju s eksperimentalnim rezultatom. Također smo izračunali strukturu elekronskih vrpci i gustoće stanja da bismo ukazali na mogućnost da na visokim tlakovima selen u fazi bcc može postati metal. Nadalje, izračunali smo koeficijent elektronske specifične topline koji se smanjuje s porastom tlaka

A rewriting view of simple typing

This paper shows how a recently developed view of typing as small-step abstract reduction, due to Kuan, MacQueen, and Findler, can be used to recast the development of simple type theory from a rewriting perspective. We show how standard meta-theoretic results can be proved in a completely new way, using the rewriting view of simple typing. These meta-theoretic results include standard type preservation and progress properties for simply typed lambda calculus, as well as generalized versions where typing is taken to include both abstract and concrete reduction. We show how automated analysis tools developed in the term-rewriting community can be used to help automate the proofs for this meta-theory. Finally, we show how to adapt a standard proof of normalization of simply typed lambda calculus, for the rewriting approach to typing

Pneumopericardium, pneumomediastinum and air travel: A case report in a patient with Gardner syndrome

© 2020 The Author(s) Onboard aircraft medical emergencies are on the rise as commercial air traffic is increasing. However, thoracic injury secondary to air travel is extremely rare and, most reported injuries are cases of pneumothoraces. Spontaneous pneumomediastinum and pneumopericardium have been barely reported in the medical literature as a complication of air travel. We are reporting a case of spontaneous pneumopericardium and pneumomediastinum in a patient with Gardner\u27s Syndrome after a flight from Central America to New York City. The patient presented with chest discomfort. He was managed conservatively with oxygen therapy as he was hemodynamically stable throughout his stay in the hospital. A thorough work up in hospital including and esophagogram and a CT scan of the chest were none revealing of the cause. However, the patient was noted to have metastatic rectal cancer with lung involvement. The patient was discharged with instructions to avoid air travel

Fracture Resistance and Microleakage of Endocrowns Utilizing Three CAD-CAM Blocks

This study assessed marginal leakage and fracture resistance of computer-aided design/computer-aided manufacturing (CAD/CAM) fabricated ceramic crowns with intracoronal extensions into the pulp chambers of endodontically treated teeth (endocrowns) using either feldspathic porcelain (CEREC Blocks [CB], Sirona Dental Systems GmbH, Bensheim, Germany), lithium disilicate (e.max [EX], Ivoclar Vivadent, Schaan, Liechtenstein), or resin nanoceramic (Lava Ultimate [LU], 3M ESPE, St Paul, MN, USA).). Thirty extracted human permanent maxillary molars were endodontically treated. Standardized preparations were done with 2-mm intracoronal extensions of the endocrowns into the pulp chamber. Teeth were divided into three groups (n=10); each group was restored with standardized CAD/CAM fabricated endocrowns using one of the three tested materials. After cementation with resin cement, specimens were stored in distilled water at 37°C for one week, subjected to thermocycling, and immersed in a 5% methylene-blue dye solution for 24 hours. A compressive load was applied at 35 degrees to long axis of the teeth using a universal testing machine until failure. Failure load was recorded, and specimens were examined under a stereomicroscope for modes of failure and microleakage. Results were analyzed using one-way analysis of variance and Bonferroni post hoc multiple comparison tests (α=0.05). LU showed significantly (p<0.05) higher fracture resistance and more favorable fracture mode (ie, fracture of the endocrown without fracture of tooth) as well as higher dye penetration than CB and EX. In conclusion, although using resin nanoceramic blocks for fabrication of endocrowns may result in better fracture resistance and a more favorable fracture mode than other investigated ceramic blocks, more microleakage may be expected with this material

The swinging self : the costs of shifting between self-images in Alzheimer’s disease

Background: We investigated the ability of patients with Alzheimer’s disease (AD) to shift between different self-images. Methods: We developed an original task (shifting-self task) in which we invited 28 patients with AD and 30 control participants to generate “who am I” statements that describe 2 alternative self-images (ie, physical-self vs psychological-self). In a control task, participants had to generate 2 blocks of “who am I” statements (ie, physical-self block and psychological-self block). Results: Analyses showed longer completion time in both the shifting-self and control task in patients with AD than in control participants. Completion time on the shifting-self task was longer than that on the control task in patients with AD, suggesting a shifting cost in AD. Conclusion: We propose that one feature of the diminished sense of self in AD is the difficulty of patients to shift between different alternating self-images

Effects of Essential Oils and Plant Extracts on Hatching, Migration and Mortality of Meloidogyne incognita

The nematicidal activity of the essential oil/pure components and plant extracts of naturally grown aromatic plant species against hatching, migration and mortality of the root knot nematode Meloidogyne incognita was investigated. The pure components carvacrol, thymol, and linalool at 1, 2 and 4 mg liter-1 concentrations were the most toxic against M. incognita second-stage juveniles (J2s) followed by terpineol and menthone. Hatching was completely inhibited at low concentrations (2, 4 mg liter-1) of carvacrol, thymol, and linalool. Clove extracts (1 mg liter-1) of Allium sativum significantly reduced hatching activity to below 8%, followed by flower extracts of Foeniculum vulgare which reduced hatching to below 25%. These extracts were also toxic against J2s of M. incognita (LC50 43) followed by leaf extracts of Pinus pinea, Origanum syriacum, Mentha microcorphylla, Eucalyptus spp. and Citrus sinensis with an estimated LC50 of 44, 50, 65, 66 and 121 ppm respectively. Flower extracts of F. vulgare had the highest effect on J2 mortality in sand (86%). The highest concentration of essential oils (6%) was detected in leaf extracts of Origanium syriacum. Over 30 major components were identified in all the plant extracts tested