The Effect of Dentifrice on Micro-Hardness,Surface Gloss,and Micro-Roughness of Nano Filled Conventional and Bulk-Fill Polymer Composite—A Micro Indentation and Profilometric Study

The aim of the present study was to evaluate the effect of brushing with two whitening dentifrices (Colgate Optic White (COW) and Colgate Optic White Charcoal (COC)) on surface gloss, micro-roughness, and micro-hardness of nanostructured hybrid conventional (Z350) and bulk-fill (Tetric N Ceram bulk-fill) polymer composite. In total, 96 disk samples using two nano-hybrid composite polymers (Z350 and Tetric N Ceram Bulk-fill) were prepared. All specimens were exposed to two different dentifrices (COW and COC), resulting in four main subgroups in the study. Specimens were assessed for surface gloss, micro-roughness (Ra), and micro-hardness using standardized methodology. Means and standard deviations of properties compared using paired t-test, one-way and two-way ANOVA, and post hoc test. The presence of dentifrices did not show any significant difference in micro-hardness values of Z350 (p > 0.05), whereas micro-hardness of bulk-fill composite significantly reduced on dentifrices exposure (p ≤ 0.05). Bulk-fill polymer composite showed significant reduction in gloss after dentifrice exposure (p < 0.05), however, Z350 showed no significant loss of gloss due to dentifrices (p > 0.05). A significant increase in Ra was observed for both resin materials after exposure to dentifrices (COC and COW). Conventional resin composite (Z350) showed comparable surface hardness and gloss before and after dentifrice exposure, however, micro-roughness increased significantly due to dentifrice exposure. Bulk-fill resin (Tetric N Ceram) showed significant loss of micro-hardness and gloss and increase in micro-roughness on dentifrice exposure. Conventional nano-hybrid composite polymer showed better durability in resisting loss of surface properties compared to bulk-fill resin polymer in the present experiment.     

The Role of Streptococcal Cell-Envelope Proteases in Bacterial Evasion of the Innate Immune System

Bacteria possess the ability to evolve varied and ingenious strategies to outwit the host immune system, instigating an evolutionary arms race. Proteases are amongst the many weapons employed by bacteria, which specifically cleave and neutralize key signalling molecules required for a coordinated immune response. In this article, we focus on a family of S8 subtilisin-like serine proteases expressed as cell-envelope proteases (CEPs) by group A and group B streptococci. Two of these proteases known as Streptococcus pyogenes CEP (SpyCEP) and C5a peptidase cleave the chemokine CXCL8 and the complement fragment C5a, respectively. Both CXCL8 and C5a are potent neutrophil-recruiting chemokines, and by neutralizing their activity, streptococci evade a key defence mechanism of innate immunity. We review the mechanisms by which CXCL8 and C5a recruit neutrophils and the characterization of SpyCEP and C5a peptidase, including both in vitro and in vivo studies. Recently described structural insights into the function of this CEP family are also discussed. We conclude by examining the progress of prototypic vaccines incorporating SpyCEP and C5a peptidase in their preparation. Since streptococci-producing SpyCEP and C5a peptidase are responsible for a considerable global disease burden, targeting these proteases by vaccination strategies or by small-molecule antagonists should provide protection from and promote the resolution of streptococcal infections.     

Accidental ingestion of magnetic foreign body in a pediatric patient: A potentially fatal attraction

Foreign body ingestion is one of the most common pediatric emergencies. As part of their cognitive development, infants and toddlers are extremely curious and constantly explore their surroundings through their senses, namely taste. The ubiquity of toys containing magnetic elements consecutively meant an increase in the cases of children ingesting said magnets. While most ingested foreign bodies, including a single magnet, will spontaneously traverse the gastrointestinal tract without problems, some may give rise to grave and potentially life-threatening complications; the latter is often seen in the presence of 2 or more magnets or paramagnetic material. The diagnosis of ingestion of magnetic foreign bodies remains a challenge, given its often ambiguous history and presentation; nonetheless, their abundance, gravity, and preventability of their complications alone should render physicians vigilant and keep a low threshold of suspicion.     

Testing for anosmia and ageusia in patients presenting to the emergency department with suspected coronavirus disease 2019 in Saudi Arabia

ObjectiveThis study investigated the role of objective olfactory dysfunction (OD) and gustatory dysfunction (GD) testing among patients with suspected coronavirus disease 2019 (COVID-19) who presented with respiratory symptoms.MethodsA prospective, blinded, observational study was conducted in the emergency units of two tertiary hospitals. Participants were asked to identify scents in the pocket smell test (PST) and flavors in four different solutions in the gustatory dysfunction test (GDT). We assessed the level of agreement between objective findings and self-reported symptoms. We evaluated the diagnostic accuracy of chemosensory dysfunction for diagnosing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.ResultsOf 250 participants, 74 (29.6%) were SARS-CoV-2-positive. There was slight agreement between self-reported symptoms and objective findings (kappa = 0.13 and 0.10 for OD and GD, respectively). OD assessed by the PST was independently associated with COVID-19 (adjusted odds ratio = 1.89, 95% confidence interval, 1.04–3.46). This association was stronger when OD was combined with objective GD, cough, and fever (adjusted odds ratio = 7.33, 95% confidence interval, 1.17–45.84).ConclusionsNeither the PST nor GDT alone are useful screening tools for COVID-19. However, a diagnostic scale based on objective OD, GD, fever, and cough may help triage patients with suspected COVID-19.     

New methods for the estimation of Takagi–Sugeno model based extended Kalman filter and its applications to optimal control for nonlinear systems

This paper describes new approaches to improve the local and global approximation (matching) and modeling capability of Takagi–Sugeno (T‐S) fuzzy model. The main aim is obtaining high function approximation accuracy and fast convergence. The main problem encountered is that T‐S identification method cannot be applied when the membership functions are overlapped by pairs. This restricts the application of the T‐S method because this type of membership function has been widely used during the last 2 decades in the stability, controller design of fuzzy systems and is popular in industrial control applications. The approach developed here can be considered as a generalized version of T‐S identification method with optimized performance in approximating nonlinear functions. We propose a noniterative method through weighting of parameters approach and an iterative algorithm by applying the extended Kalman filter, based on the same idea of parameters’ weighting. We show that the Kalman filter is an effective tool in the identification of T‐S fuzzy model. A fuzzy controller based linear quadratic regulator is proposed in order to show the effectiveness of the estimation method developed here in control applications. An illustrative example of an inverted pendulum is chosen to evaluate the robustness and remarkable performance of the proposed method locally and globally in comparison with the original T‐S model. Simulation results indicate the potential, simplicity, and generality of the algorithm. An illustrative example is chosen to evaluate the robustness. In this paper, we prove that these algorithms converge very fast, thereby making them very practical to use. Copyright © 2011 John Wiley & Sons, Ltd.     

Simultaneous nephrectomy and coronary artery bypass grafting through extended sternotomy

A 37-year-old man with end-stage idiopathic dilated cardiomyopathy underwent an orthotopic heart transplant followed by a reoperation with mitral annuloplasty for severe mitral regurgitation. Shortly thereafter, he developed severe tricuspid regurgitation and severe recurrent mitral regurgitation due to annuloplasty ring dehiscence. The dehisced annuloplasty ring was refixated, followed by tricuspid annuloplasty through a right anterolateral thoracotomy. After four years of follow-up, there are no signs of recurrent mitral or tricupid regurgitation and the patient remains in NYHA class II. Pushing the envelope on conventional surgical procedures in marginal donor hearts (both before and after transplantation) may not only improve the patient??s functional status and reduce the need for retransplantation, but it may ultimately alleviate the chronic shortage of donor hearts.     

Equine Babesiosis: Seroprevalence,Risk Factors and Comparison of Different Diagnostic Methods in Jordan

The purposes of this study were to estimate the seroprevalence and distribution of horse piroplasmosis, to evaluate risk factors associated with the occurrence of the disease and to compare the different diagnostic methods used for this disease. A total of 253 clinically normal horses were sampled, and a collection form was completed for each horse from five of six different climatic zones of Jordan. The sixth zone was not sampled because it did not include horse population. Competitive enzyme‐linked immunosorbent assay (cELISA) revealed 37 horses (14.6%) positive for Theileria equi, and none of the horses was positive for Babesia caballi. Microscopic examination of thin blood smears and PCR test revealed no positive results for either parasite. Grazing was the only risk factor that was associated with being seropositive to the disease; horses that graze are 11.5 more likely to be seropositive (P < 0.05, OR = 11.5, CI: 3.292, 39.962). This is the first study to estimate the prevalence of horse babesiosis using serological test and to identify risk factors associated with the disease in Jordan. Competitive enzyme‐linked immunosorbent assay (cELISA) test appears to be more reliable than microscopic examination and PCR in estimating the seroprevalence of the disease as well as identifying carrier horses to babesiosis.     

Robotic uretero-ureterostomy of the retrocaval ureter without excision of the retrocaval segment

Robotic reconstruction of the retrocaval ureter is gaining momentum as the method of choice for surgically treating this rare condition. Maintaining the retrocaval ureteric segment further facilitates the procedure. We report a case of a 23-year-old man who underwent intraperitoneal robotic resection anastomosis and repositioning of the retrocaval ureter. We also discuss the advantages of this technique.