Re-Examination of the NO + O Reaction.

The reaction of NO with O is a key step in consumption of nitrous oxide in thermal processes. It has two product channels, NO + NO (R2) and N + O (R3). The rate constant for R2 has been measured both in the forward and the reverse direction at elevated temperature and is well established.

Evaluation of the bacterial contamination of face masks worn by personnel in a center of COVID 19 hospitalized patients: A cross-sectional study.

Background: During the Coronavirus Pandemic, the use of masks has increased significantly. The lack of control on hygiene protocols and the need to use PPE properly increases the spread of bacterial infection. The purpose of this study was to investigate the degree of contamination and frequency of bacterial species isolated from surgical and N95 masks used by hospital personnel.

Fully Digital versus Conventional Workflows for Fabricating Posterior Three-Unit Implant-Supported Reconstructions: A Prospective Crossover Clinical Trial.

This study assessed the clinical variables influencing the success of three-unit implant-supported fixed dental prostheses (ISFDPs) fabricated using either fully digital or conventional workflows. The clinical trial evaluated 10 patients requiring three-unit ISFDPs in the posterior mandible. Maxillomandibular relation records, and digital and conventional impressions were obtained from each patient using an intraoral scanner (IoS) and polyvinylsiloxane (PVS), and the frameworks were fabricated using zirconia and cobalt-chromium, respectively.

Prevalence of Ocular Complications in Patients with Zygomatic Bone Fractures in an Iranian Population.

Objectives: Damages to the middle third of the facial bone generally involve the orbital skeleton and can lead to eye impairment. In this study, it is attempted to determine the incidence of ophthalmic injuries in maxillofacial trauma with zygomatic bone fractures.

Materials And Methods: One hundred and fifteen cases with ophthalmic (ocular) involvement after maxillofacial trauma were referred to the Shariati Hospital, Tehran, Iran, and were visited at the Ophthalmology Department between 2016 and 2018.

On the Rate Constant for NH+HO and Third-Body Collision Efficiencies for NH+H(+M) and NH+NH(+M).

In low-temperature flash photolysis of NH/O/N mixtures, the NH consumption rate and the product distribution is controlled by the reactions NH + HO → products (R1), NH + H (+M) → NH (+M) (R2), and NH + NH (+M) → NH (+M) (R3). In the present work, published flash photolysis experiments by, among others, Cheskis and co-workers, are re-interpreted using recent direct measurements of NH + H (+N) and NH + NH (+N) from Altinay and Macdonald. To facilitate analysis of the FP data, relative third-body collision efficiencies compared to N for R2 and R3 were calculated for O and NH as well as for other selected molecules.

Comparing 4-mm dental implants to longer implants placed in augmented bones in the atrophic posterior mandibles: One-year results of a randomized controlled trial.

Background: Short implants have been proposed as an alternative for the rehabilitation of atrophic edentulous areas.

Purpose: To evaluate the efficacy of 4-mm implants vs longer implants in the atrophic posterior mandibles.

Materials And Methods: Eleven patients with bilateral atrophic mandibles were rehabilitated with two to four 4-mm implants and 10 or 8-mm long implants in augmented bone using Guided Bone Regeneration procedure.

Comparison of Short and Standard Implants in the Posterior Mandible: A 3D Analysis Using Finite Element Method.

Objectives: This study aimed to analyze functional stresses around short and long implant-supported prostheses with different crown heights.

Materials And Methods: Four three-dimensional (3D) models were designed with SolidWorks 2015. In models 1 (control) and 2, three dental implants (second premolar 4.

Ab initio calculations and kinetic modeling of thermal conversion of methyl chloride: implications for gasification of biomass.

Limitations in current hot gas cleaning methods for chlorine species from biomass gasification may be a challenge for end use such as gas turbines, engines, and fuel cells, all requiring very low levels of chlorine. During devolatilization of biomass, chlorine is released partly as methyl chloride. In the present work, the thermal conversion of CH3Cl under gasification conditions was investigated.

Hierarchical analysis and multi-scale modelling of rat cortical and trabecular bone.

The aim of this study was to explore the hierarchical arrangement of structural properties in cortical and trabecular bone and to determine a mathematical model that accurately predicts the tissue's mechanical properties as a function of these indices. By using a variety of analytical techniques, we were able to characterize the structural and compositional properties of cortical and trabecular bones, as well as to determine the suitable mathematical model to predict the tissue's mechanical properties using a continuum micromechanics approach. Our hierarchical analysis demonstrated that the differences between cortical and trabecular bone reside mainly at the micro- and ultrastructural levels.

Full-mouth rehabilitation of an edentulous patient with Papillon-Lefèvre syndrome using dental implants: a clinical report.

Papillon-Lefèvre syndrome (PLS) is a rare autosomal recessive disorder. The oral manifestations of the syndrome include rapidly progressive periodontal disease resulting in premature exfoliation of primary and permanent dentitions. Patients are often edentulous at an early age and require prosthodontic treatment.

The effect of sutureless wound closure on postoperative pain and swelling after impacted mandibular third molar surgery.

Our aim was to assess the influence of sutureless and multiple-suture closure of wounds on postoperative complications after extraction of bilateral, impacted, mandibular third molars in 30 patients in a split mouth study. After the teeth had been removed, on one side the flap was replaced but with no suture to hold it in place (study side), and on the other side the wound was closed primarily with three sutures (control side). Recorded complications included pain, swelling, bleeding, and formation of periodontal pockets.

The prevalence of maxillofacial fractures due to domestic violence--a retrospective study in a hospital in Tehran, Iran.

Background/aim: Domestic violence has been identified as a cause of maxillofacial fractures especially among women. The present study investigated the maxillofacial fractures in Tehran, Iran, with special focus on injuries related to domestic violence.

Material And Methods: Records of patients with maxillofacial fractures who were referred to Shariati hospital, Tehran, from June 2004 to June 2006 were considered to extract required data.

Complications using intermaxillary fixation screws.

Purpose: The most important part of facial bone fracture treatment is immobilization. Bandaging of the fractured mandible was the first immobilization device used in ancient Greece. Since then, various methods with different shapes and uses were introduced in the treatment of maxillofacial trauma patients.

Receptor tyrosine phosphatase PTPγ is a regulator of spinal cord neurogenesis.

During spinal cord development the proliferation, migration and survival of neural progenitors and precursors is tightly controlled, generating the fine spatial organisation of the cord. In order to understand better the control of these processes, we have examined the function of an orphan receptor protein tyrosine phosphatase (RPTP) PTPγ, in the developing chick spinal cord. Widespread expression of PTPγ occurs post-embryonic day 3 in the early cord and is consistent with a potential role in either neurogenesis or neuronal maturation.

Bacterial contamination of autogenous bone collected by rongeur compared with that collected by bone filter during implant surgery.

The aim was to compare the degree of microbial contamination of autogenous bone collected by a bone filter with that of autogenous bone harvested by a rongeur during implant surgery. Thirty healthy patients had dental implants inserted. A strict aspiration protocol was used during the operation to collect particulate bone with minimal risk of contamination by oral flora.

Comparison between interpositional bone grafting and osteogenic alveolar distraction in alveolar bone reconstruction.

Purpose: The aim of this study was to compare the quality and quantity of bone produced by alveolar distraction and interpositional bone grafting.

Patients And Methods: Twelve patients requiring alveolar reconstruction were randomly divided into 2 groups. Six patients were treated with alveolar distraction osteogenesis, and 6 were treated with the sandwich osteotomy technique and tibial bone grafting.

Clinical features of patients with typhoid fever and drug resistance of the causative isolates in western Iran.

Typhoid fever is an important infectious disease in developing countries, including Iran. In this survey, all patients hospitalized in teaching hospitals of Hamedan during 1995-2005 were investigated. A total of 162 patients with typhoid fever were studied.

Kinetics of primary and memory cytotoxic T lymphocyte responses to herpes simplex virus 1 infection: granzyme B mediated CTL activity.

Background: Herpes simplex virus type 1 is one of the most common viruses among human population. Studies demonstrate the essential role of cell mediated immunity, especially CD8+ T cells, in prevention and clearance of HSV1.

Objective: It is of great importance to improve our knowledge about the kinetics of CTL responses to primary and secondary HSV-1 infection.

Evaluation of intraoral verticosagittal ramus osteotomy for correction of mandibular prognathism: a 10-year study.

Purpose: To identify intraoperative complications, neurosensory disturbance (NSD), and horizontal relapse after surgical correction of mandibular prognathism using bilateral intraoral verticosagittal ramus osteotomy (IVSRO).

Patients And Methods: Between 1995 and 2005, 237 Iranian patients underwent IVSRO to achieve mandibular setback. Their operation reports, cephalometric radiographs (2 weeks preoperatively and 12 months postoperatively), and neurosensory questionnaires were assessed to identify intraoperative complications, NSD of the inferior alveolar nerve (IAN), and horizontal relapse.