Amidation of Enones via Beckmann Rearrangement.

The Beckmann reaction is one of the most atom-economical methods for the preparation of amides from ketones. Unlike ketones, the multiple competing reactivities of enones as well as the requirement of demanding reaction conditions for in situ generation of oximes have severely impacted the application of this reaction for the preparation of α,ß-unsaturated amides. Herein, we describe the first chemoselective method for the direct conversion of enones to the corresponding α,ß-unsaturated amides using N-Boc-O-tosylhydroxylamine.

Evaluation of membrane cake fouling mechanism to estimate design parameters of a submerged AnMBR treating high strength industrial wastewater.

A mathematical model, which was previously developed for submerged aerobic membrane bioreactors, was successfully applied to elucidate the membrane cake-layer fouling mechanisms due to bound extracellular polymeric substances (eEPS) in a submerged anaerobic membrane bioreactor (SAnMBR). This biofouling dynamic model explains the mechanisms such as attachment, consolidation and detachment of eEPS produced in the bioreactor on the membrane surface. The 4th order Runge-Kutta method was used to solve the model equations, and the parameters were estimated from simulated and experimental results. The key design parameters representing the behaviour of cake fouling dynamics were systematically investigated. Organic loading rate (OLR) was considered a controlling factor governing the mixed liquor suspended solids (MLSS), eEPS production, filtration resistance (Rt), and transmembrane pressure (TMP) variations in a SAnMBR. eEPS showed a proportional relation with OLR at subsequent MLSS variations. The consolidation of EPS increased the specific eEPS resistance (αs), influencing the cake resistance (Rc). The propensities of eEPS showed a positive correlation with Rt and TMP. The outcomes of the study also estimated a set of valuable design parameters which would be vital for applying in AnMBRs treating industrial wastewater.

Quest for Biomarkers of Positive Health: A Review.

The positive health of a person can be defined as the ability to live long in good health, possibly with no activity limitation. No method is yet available for its objective assessment in individuals, and we propose a framework in this communication that can operationalize this concept. Instead of distal factors, such as diet and lifestyle because these are subjective and difficult to measure, we concentrate on the objectively measurable biomarkers such as immunity level, endorphins, and handgrip strength. The focus is on the major parameters that may protect from diseases and infirmity and can be assessed by noninvasive methods. A combination of such parameters may signify positive health. This may be a novel way to measure positive health at the individual level. In this communication, we briefly review the literature and identify a few major biomarkers that provide a protective shield and could determine the status of positive health at the individual level. This exercise demonstrates that the assessment of the positive health of a person is feasible. A scale based on these and other relevant parameters can be developed later that could quantitatively measure the exact level of positive health. As the exact combination of the parameters that protects from ailments is not fully known yet, a framework such as this may help in identifying the data gaps that require attention in this context. The proposed framework may initiate a discussion on indicators of positive health and characterize the parameters for intervention that could increase a healthy life.

CBCT Evaluation of Lingual Foramen and its Anatomic Variations in Northeast Indian Population.

Background: The identification of nearby neurovascular structures is a vital part of dental implant treatment planning. Commonly two implants are placed in the mandibular inter foraminal region to support the overdenture. Placing dental implants in this region is considered relatively safe. The purpose of this study was to employ cone beam computed tomography (CBCT) on a representative sample of Northeast Indians to find out the location and distribution of lingual foramen in the anterior mandible. Study Design: A total of 104 CBCT scans were performed using the Cranex 3D CBCT system. Three Oral and Maxillofacial Radiologists agreed on a visibility grade for assessing the lingual foramen using a 3-point scale. The number and presence of foramina were noted. On cross-sectional pictures, the distance in millimeters between the crest of the alveolar ridge and the superior cortical margin of the foramen was determined. Furthermore, the analysis of the distribution of lingual foramina in terms of frequency and percentages was performed. Results: Scan results showed that the lingual foramen was clearly visible in 65.4% of cases, somewhat visible in 12.5% of scans, and not visible at all in 22.1% of cases. Half of the people in the study had two foramina, whereas 27.9 percent had one and 22.1 percent had none. The mean distance from the crest of the alveolar ridge was 10.84 mm in males whereas 9.91 mm in females. Conclusion: The Northeast Indian population exhibits an unusually high prevalence of lingual foramen in the anterior portion of the mandible. This research will aid in the precise pre-operative identification of the position and number of lingual foramina prior to surgical treatments involving the midline of the mandible.

Recurrent Oral Ulcers and Its Association With Stress Among Dental Students in the Northeast Indian Population: A Cross-Sectional Questionnaire-Based Survey.

Aim The term "aphthous" is derived from the Greek word "aphtha," which means ulceration. The cause of aphthous ulcers is multifactorial, but emotional stress is one of the most important risk factors for its occurrence in young individuals. The aim of this study was to evaluate the association of recurrent oral ulcers (ROUs) with stress among dental students in the Northeast Indian Population. Materials and methods A total of 1,134 students were recruited for the study. Two sets of questionnaires were designed. The first set consisted of 11 questions related to demographic data and information about recurrent oral ulcers. The second set of questionnaire had 14 questions related to stress symptoms. Google Forms (Google, Inc., Mountain View, CA, USA) was used for recording the responses of the study participants. Questionnaires were sent to the participants through e-mail, and responses were recorded. Statistical analysis was done using the Statistical Package for the Social Sciences (SPSS) version 21 (IBM SPSS Statistics, Armonk, NY, USA) and Microsoft Office Excel (Microsoft Corp., Redmond, WA, USA). The chi-square test was used to compare categorical variables. Results Among the 1,134 participants, 32.7% (371 students) reported a previous history of recurrent oral ulcers. Out of 371 participants who had given a history of oral ulcers, only 27.2% exhibited direct stress to ulcer association. On further assessment using the Perceived Stress Scale (PSS), it was found that a far greater percentage of students (i.e., more than 27.2%) were under some form of stress or the other. Conclusions The results of this study will help improve the quality of life among the study population, either by tackling their stress levels or by identifying adequate interventions.

Targeting caspase pathway by novel N-Me aziridine derivatives for hepatocellular carcinoma drug discovery.

Azaheterocycles are three-membered rings, known as aziridines, that occur naturally and have pharmaceutical applications.These compounds are present as several secondary metabolites produced by plants and microorganisms.Recent studies have demonstrated the effectiveness of aziridine derivatives (N-H/N-Me) as anticancer agents.We synthesized 18 compounds containing an N-Me enone aziridine group, the chemistry of which has been previously published. However, these compounds have drug-likeness properties; therefore, we aimed to demonstrate their drug-like properties using in silico and in vitro investigations.The molecular structures of the compounds were optimized using density functional theory (DFT). The ADMET parameters of the derivatives were calculated using SwissADME and PreADMET. Additionally, these derivatives were evaluated for their ability to bind to caspase-3 and caspase-9 and then subjected to molecular docking. The lead chemical AY128 maintained stable complexes with target proteins during molecular dynamics simulations, as evidenced by the root mean square deviation (RMSD) and root mean square fluctuation (RMSF) parameters. In vitro cytotoxicity and ELISA tests showed that the novel aziridine derivatives, especially AY128, had strong anticancer activity against HepG2 hepatocellular carcinoma cells.Our study suggests that AY128 may be a potential drug candidate for hepatocellular carcinoma through the caspase-3 and caspase-9-dependent apoptotic pathways.Communicated by Ramaswamy H. Sarma.

Quantification and distribution of mast cells in oral periapical inflammatory lesions.

Background: Periapical granuloma and periapical cysts develop as a sequela of inflammation of dental pulp, usually a consequence of an infected root canal. Mast cells (MCs) have most frequently been implicated in the pathophysiology of periapical lesions such as periapical granulomas and cysts. Aims: The present study was undertaken to emphasize the presence and quantification of MCs in periapical lesions (granulomas and cysts) using toluidine blue stain, with an aim to elucidate their role in the pathogenesis of these lesions. Materials and Methods: The study comprised a total of 55 previously diagnosed cases (30 cases of radicular cyst and 25 cases of periapical granuloma) selected from the departmental archives. The MCs were quantified in all the sections in the three zones, namely the epithelial, subepithelial, and deeper connective tissue zones. The results were sent for statistical analysis. Statistical Analysis: Wilcoxon paired t-test and Mann-Whitney U test were applied for intra- and intergroup comparison MCs in different zones of periapical granulomas and radicular cyst, respectively. Results: A statistically significant difference was observed between the two lesions in all the three zones, i.e., epithelial, subepithelial, and in deeper connective tissue zone with P = 0.001. Conclusion: Although MCs were present in all the three zones of both periapical cysts and granuloma, they were predominantly observed in radicular cysts than in periapical granuloma. This suggests a significant role of MC in initiation, development, and progression of these periapical lesions.

Cu(OTf)2-catalyzed Beckmann Rearrangement of Ketones Using Hydroxylamine-O-sulfonic Acid (HOSA).

The Beckmann Rearrangement (BKR) of ketones to secondary amides often requires harsh reaction conditions that limit its practicality and scope. Herein, we describe the Cu(OTf)2-catalyzed BKR of ketones under mild reaction conditions using hydroxylamine-O-sulfonic acid (HOSA), a commercial water soluble aminating agent. This method is compatible with most functional groups and directly provides the desired amides in good to excellent yields.

Radiomorphometric analysis of frontal sinus for sex determination.

CONTEXT: Sex determination of unknown individuals carries crucial significance in forensic research, in cases where fragments of skull persist with no likelihood of identification based on dental arch. In these instances sex determination becomes important to rule out certain number of possibilities instantly and helps in establishing a biological profile of human remains. AIMS: The aim of the study is to evaluate a mathematical method based on logistic regression analysis capable of ascertaining the sex of individuals in the South Indian population. SETTINGS AND DESIGN: The study was conducted in the department of Oral Medicine and Radiology. METHODS AND MATERIAL: The right and left areas, maximum height, width of frontal sinus were determined in 100 Caldwell views of 50 women and 50 men aged 20 years and above, with the help of Vernier callipers and a square grid with 1 square measuring 1mm(2) in area. STATISTICAL ANALYSIS USED: Student's t-test, logistic regression analysis. RESULTS: The mean values of variables were greater in men, based on Student's t-test at 5% level of significance. The mathematical model based on logistic regression analysis gave percentage agreement of total area to correctly predict the female gender as 55.2%, of right area as 60.9% and of left area as 55.2%. CONCLUSION: The areas of the frontal sinus and the logistic regression proved to be unreliable in sex determination. (Logit = 0.924 - 0.00217 × right area).