Biomaterial Properties of Titanium in Dentistry

Background Among various dental materials and their successful restorative uses, titanium provides an excellent example of integrating science and technology involving multiple disciplines of dentistry including biomaterials, prosthodontics and surgical sciences. Titanium and its alloys have emerged as a material of choice for dental implants fulfilling all requirements biologically, chemically and mechanically. Several excellent reviews have discussed the properties of titanium and its surface characteristics that render it biocompatible. However, in most patients, titanium implants are used alongside several other metals. Presence of different metals in the same oral environment can alter the properties of titanium. Other influencing factors include intra-oral pH, salivary content, and effect of fluorides. Highlight This review discusses the effect of the above-mentioned conditions on the properties of titanium and its alloys. An extensive literature search encompassing the properties of titanium in an altered oral environment and its interaction with other restorative materials is presented. Specific conditions that could cause titanium to corrode, specifically due to interaction with other dental materials used in oral rehabilitation, as well as methods that can be employed for passivation of titanium are discussed. Conclusion This review presents an overview of the properties of titanium that are vital for its use in implant dentistry. From a restorative perspective, interaction between implant restoration metals, intra-oral fluorides and pH may cause titanium to corrode. Therefore, in order to avoid the resulting deleterious effects, an understanding of these interactions is important for long-term prognosis of implant restorations

Propagation of a curved weak shock

Propagation of a curved shock is governed by a system of shock ray equations which is coupled to an infinite system of transport equations along these rays. For a two-dimensional weak shock, it has been suggested that this system can be approximated by a hyperbolic system of four partial differential equations in a ray coordinate system, which consists of two independent variables (ζ, t) where the curves t = constant give successive positions of the shock and ζ = constant give rays. The equations show that shock rays not only stretch longitudinally due to finite amplitude on a shock front but also turn due to a non-uniform distribution of the shock strength on it. These changes finally lead to a modification of the amplitude of the shock strength. Since discontinuities in the form of kinks appear on the shock, it is necessary to study the problem by using the correct conservation form of these equations. We use such a system of equations in conservation form to construct a total-variation-bounded finite difference scheme. The numerical solution captures converging shock fronts with a pair of kinks on them-the shock front emerges without the usual folds in the caustic region. The shock strength, even when the shock passes through the caustic region, remains so small that the small-amplitude theory remains valid. The shock strength ultimately decays with a well-defined geometrical shape of the shock front-a pair of kinks which separate a central disc from a pair of wings on the two sides. We also study the ultimate shape and decay of shocks of initially periodic shapes and plane shocks with a dent and a bulge

Role of office hysteroscopy in gynecology: retrospective observational study at a tertiary care hospital

Background: Hysteroscopy being the gold standard for evaluation of uterine cavity can be utilized for varied gynaecological indications. Conventionally, hysteroscopy is performed under general anaesthesia but with technical advances over years, it is now possible to do the procedure in ambulatory office setting with same diagnostic accuracy. Aim of this study was to assess the role of hysteroscopy as a diagnostic tool in office setting, to evaluate various gynaecological conditions.Methods: Study performed retrospective analysis on 1920 patients who underwent office hysteroscopy between Jan 2011 to Apr 2015, at outpatient department of a tertiary care centre at Maharashtra, India. The procedure was done in office setting without any sedation or anaesthesia. Approach used was vaginoscopic free hand technique with minimal instrumentation and the findings were documented after evaluation of uterine cavity, ostea and endocervical canal.Results: Office hysteroscopy could be successfully performed in 1920 out of 1938 patients. Most common indications were primary infertility (38.0%), secondary infertility (11.2%), abnormal uterine bleeding (36.6%) and postmenopausal bleeding (8.3%). The procedure done in office setting was tolerated well. The procedure was also used for evaluation in patients with breast and endometrial carcinoma.Conclusions: Office hysteroscopy by vaginoscopic approach is a simple and convenient method for evaluation of uterine cavity and cervical canal. It has the potential to come out from formal operation theatre to more patient friendly outpatient department

Field Assisted Sintering Techniques in Recycling NdFeB Magnets

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Tuberculous Aortic Root Abscess in a child: A case report

Although tuberculous aortitis is fairly common in adults, tuberculous mycotic aneurysm of aorta is rare withinvolvement of aortic root being very uncommon. The diagnosis depends on a combination of clinical criteria,including persistent fever and bacteraemia and echocardiographic confirmation. Because of the rarity of aorticroot abscess in children, there is no consensus on a treatment strategy. We describe a 10-year-old male whopresented with fever, abdominal pain and headache, and was found to have disseminated tuberculosis and aorticroot abscess with mycotic aneurysm. Due to the presence of evidence of tuberculosis elsewhere in the body(multiple tuberculomas in brain, granulomas in liver, lichen scrofulosorum over abdomen), therapy with antituberculousdrugs was started to which the patient responded partially, but later died suddenly at home

Branching Rules for Supercuspidal Representations of SL_2(k)

The restriction of a supercuspidal representation of SL_2(k), for k a local nonarchimedean field, to a maximal compact subgroup decomposes as a multiplicity-free direct sum of irreducible representations. We explicitly describe this decomposition in the case that the residual characteristic is odd, and determine how the spectrum of this decomposition varies as a function of the parameters describing the supercuspidal representation.Comment: 30 pages; minor reorganization to previous version. Accepted to Journal of Algebr

Intraosseous (IO) vs Intravenous (IV) Vascular Access for Out of Hospital Cardiac Arrest.

Over 300,000 Americans every year experience an out-of-hospital cardiac arrest (OHCA) (Benjamin EJ 2019). Of these 300,000+ patients only 10.6% of them survive to hospital discharge. Advanced Cardiac Life Support (ACLS) has been suggested to improve survival following an OHCA (Neumar, Otto et al. 2010). Current ACLS guidelines recommend obtaining vascular access, however, offer little suggestion as to which type of access device should be used. It is our belief that using an Intraosseous vascular access device will lead to shorter time to medication delivery and increased rates of return of spontaneous circulation (ROSC) compared to Intravenous vascular access. We conducted a retrospective chart review study with patients from Detroit Receiving Hospital and Sinai- Grace Hospital from January 1st, 2014 to December 31st, 2015. Over 3000 OHCA patients were used for this study. Only adult OHCA patients with vascular access obtained in the Emergency Department were included in the study for data analysis. Chart review was conducted by research personnel who underwent a standardized training procedure. The forms of vascular access, time to first ACLS medication, and return of ROSC were the main parameters recorded. Data analysis was conducted using IBM SPSS- Statistics (2015) or a similar statistical software. The initial data shows that there is no statistical difference in ROSC rates when comparing IO lines to IV lines. We are currently in the process of analyzing the data on time to first medication delivery between IO and IV lines. We intend to publish this study in peer reviewed journals, and to present the results at local, regional, and national presentations. It is our intention that this study will serve as a pilot study for future randomized control trials comparing different vascular access devices for OHCA patients in the Emergency Department. References: Benjamin EJ, M. P., Alonso A, & Bittencourt MS. (2019). Heart disease and stroke Statistics—2019 update: A report from the American Heart Association. . Neumar, R. W., et al. (2010). Part 8: adult advanced cardiovascular life support: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 122(18 Suppl 3): S729-767

Combatting Corruption Among Civil Servants (2017): Interdisciplinary Perspectives on What Works

In 2016, USAID's Center of Excellence on Democracy, Human Rights, and Governance launched its Learning Agenda—a set of research questions designed to address the issues that confront staff in USAID field offices working on the intersection of development and democracy, human rights, and governance. This literature review—produced by a team of economists, political scientists, sociologists, and anthropologists—synthesizes scholarship from diverse research traditions on the following Learning Agenda question:In the context of hiring civil servants and providing positive and negative incentives for their behavior, what kinds of interventions are most effective at reducing the propensity (potential and actual) of civil servants to engage in corruption?Overall there was not a great deal of rigorous academic evidence either for or against the majority of commonly prescribed anti-corruption strategies, with the partial exception of anti-corruption audits and e-governance. These findings are discussed at length in the publication, and contextualized within a broader analysis why the first wave of corruption reforms has generated so few success stories

Sulforaphane Induces Cell Cycle Arrest, Migration, Invasion, and Apoptosis in Epithelial Ovarian Cancer Cells

Objectives: Isothiocyanates (ITC) has long been shown to demonstrate chemopreventive properties. Sulforaphane (SFN) is a major ITC present in broccoli and other cruciferous vegetables. We reviewed the current literatures of SFN on ovarian carcinoma cell lines. Methods: Studies were conducted on the effects of SFN on the growth of the OVCAR-3, MDAH 2774 and SKOV-3 ovarian carcinoma cell lines. Chuang et al. evaluated the effect of SFN on ovarian cancer cell cycles. Subsequently Chaudhuri et al. determined the specific pathway that was affected and Bryant et al. explored the signaling mechanisms through which SFN influences the cell growth and proliferation in ovarian cancer cell lines. Results: Chuang et al. showed a concentration dependent decrease in cell density. Analysis of cell cycle phase progression revealed a decrease in the cell populations in S and G2M phases, with an increase of G1 cell population, indicating a G1 cell cycle arrest. The degree of decrease in the replicating population was concentration and time dependent. These results clearly demonstrated an effect of SFN in inducing growth arrest and apoptosis in ovarian carcinoma cell lines. Chaudhuri et al. investigated the effects of sulforaphane on Akt signal transduction pathway. Both total Akt protein and active phosphorylated levels of Akt and phosphoinositide 3-kinase were significantly decreased in sulforaphane-treated ovarian cancer cell lines. Utilizing gene expression profile analysis, Bryant et al. showed SFN treatment resulted in G1 cell cycle arrest through down modulation of RB phosphorylation and by protecting the RB-E2F-1 complex. Conclusions: SFN induced growth arrest and cell death in ovarian cancer cells in G1 cell cycle arrest. The Akt pathway was identified as the possible target for SFN. SFN suppresses growth of ovarian cancer cells in vitro by modulating cell cycle regulatory proteins and by enhancing apoptosis. Inhibition of retinoblastoma (RB) phosphorylation and reduction in levels of free E2F-1 appear to play an important role in ovarian cancer growth arrest, migration, and invasion

WAFER trial: a study protocol for a feasibility randomised controlled trial comparing wide-awake local anaesthesia no tourniquet (WALANT) to general and regional anaesthesia with tourniquet for flexor tendon repair

Introduction: Flexor tendons are traditionally repaired under either general anaesthesia (GA) or regional anaesthesia (RA), allowing for the use of an arm tourniquet to minimise blood loss and establish a bloodless surgical field. However, the use of tourniquets exposes the patient to certain risks, including skin, muscle and nerve injuries. A recent advancement in anaesthesia delivery involves the use of a wide-awake approach where no sedation nor tourniquets are used (wide-awake local anaesthesia no tourniquet (WALANT)). WALANT uses local anaesthetic with epinephrine to provide pain relief and vasoconstriction, reducing operative bleeding. Several studies revealed potential benefits for WALANT compared with GA or RA. However, there remains a paucity of high-quality evidence to support the use of WALANT. As a result of this uncertainty, the clinical practice varies considerably. We aim to evaluate the feasibility of WALANT as an alternative to GA and RA in patients undergoing surgical repair of flexor tendon injuries. This involves addressing factors such as clinician and patient support for a trial, clinical equipoise, trial recruitment and dropout and the most relevant outcomes measures for a future definitive trial. // Methods and analysis: WAFER is a multicentre, single-blinded, parallel group, randomised controlled trial (RCT) to assess the feasibility of WALANT versus RA and GA. The target population is patients with acute traumatic flexor tendon injuries, across 3 major hand surgery units in England involving a total of 60 participants. Outcome assessors will be blinded. The primary outcome will be the ability to recruit patients into the trial, while secondary outcomes include difference in functional outcome, patient-reported outcome measures, health-related quality of life, cost-effectiveness and complication rates. // Ethics and dissemination: Ethical approval was obtained from the London—City and East Research Ethics Committee (22/PR/1197). Findings will be disseminated through peer-reviewed publication, conferences, patient information websites and social media networks