Tuning the Multiferroic Properties of BiFeO_{3} under Uniaxial Strain.

More than twenty years ago, multiferroic compounds combining in particular magnetism and ferroelectricity were rediscovered. Since then, BiFeO_{3} has emerged as the most outstanding multiferroic by combining at room temperature almost all the fundamental or applicative properties that may be desired: electroactive spin wave excitations called electromagnons, conductive domain walls, or a low band gap of interest for magnonic devices. All these properties have so far only been discontinuously strain engineered in thin films according to the lattice parameter imposed by the substrate. Here we explore the ferroelectricity and the dynamic magnetic response of BiFeO_{3} bulk under continuously tunable uniaxial strain. Using elasto-Raman spectroscopy, we show that the ferroelectric soft mode is strongly enhanced under tensile strain and driven by the volume preserving deformation at low strain. The magnonic response is entirely modified with low energy magnon modes being suppressed for tensile strain above pointing out a transition from a cycloid to an homogeneous magnetic state. Effective Hamiltonian calculations show that the ferroelectric and the antiferrodistortive modes compete in the tensile regime. In addition, the homogeneous antiferromagnetic state becomes more stable compared to the cycloidal state above a +2% tensile strain close to the experimental value. Finally, we reveal the ferroelectric and magnetic orders of BiFeO_{3} under uniaxial strain and how the tensile strain allows us to unlock and to modify in a differentiated way the polarization and the magnetic structure.

First principles computation of composition dependent elastic constants of omega in titanium alloys: implications on mechanical behavior.

For decades the poor mechanical properties of Ti alloys were attributed to the intrinsic brittleness of the hexagonal ω-phase that has fewer than 5-independent slip systems. We contradict this conventional wisdom by coupling first-principles and cluster expansion calculations with experiments. We show that the elastic properties of the ω-phase can be systematically varied as a function of its composition to enhance both the ductility and strength of the Ti-alloy. Studies with five prototypical ß-stabilizer solutes (Nb, Ta, V, Mo, and W) show that increasing ß-stabilizer concentration destabilizes the ω-phase, in agreement with experiments. The Young's modulus of ω-phase also decreased at larger concentration of ß-stabilizers. Within the region of ω-phase stability, addition of Nb, Ta, and V (Group-V elements) decreased Young's modulus more steeply compared to Mo and W (Group-VI elements) additions. The higher values of Young's modulus of Ti-W and Ti-Mo binaries is related to the stronger stabilization of ω-phase due to the higher number of valence electrons. Density of states (DOS) calculations also revealed a stronger covalent bonding in the ω-phase compared to a metallic bonding in ß-phase, and indicate that alloying is a promising route to enhance the ω-phase's ductility. Overall, the mechanical properties of ω-phase predicted by our calculations agree well with the available experiments. Importantly, our study reveals that ω precipitates are not intrinsically embrittling and detrimental, and that we can create Ti-alloys with both good ductility and strength by tailoring ω precipitates' composition instead of completely eliminating them.

Contribution of neuropsychiatric symptoms in Parkinson's disease to different domains of caregiver burden.

INTRODUCTION: Caregiver burden is high among caregivers of PD patients (CPD). Neuropsychiatric symptoms are leading contributors to CPD burden, but whether different symptoms differentially impact domains of caregiver burden is not known. Our objective was to examine which neuropsychiatric symptoms and demographic factors contribute to different domains of caregiver burden in PD. METHODS: This was a cross-sectional online survey study. Participants were recruited from the Fox Insight (FI) study and were eligible if they identified themselves as a CPD. The primary outcome was the Caregiver Burden Inventory (CBI) total score and its 5 sub-domain scores. The Neuropsychiatric Inventory Questionnaire (NPI-Q) assessed caregiver-reported neuropsychiatric symptoms in the care recipient. Multivariable linear regression models were used to characterize the associations between NPI-Q symptom severity scores and CBI scores. Covariates were caregiver age, sex, education, and caregiving duration. RESULTS: The sample consisted of 450 CPD, mean age 65.87 (SD 10.39) years, 74% females. After adjusting for covariates, CBI total score was predicted by NPI-Q total score (ß = 1.96, p < 0.001); model adjusted R2 = 39.2%. Anxiety severity had the largest effect size [standardized ß (sß) = 0.224] on the time-dependency domain, which was also associated with female sex (sß = - 0.133) and age (sß = 0.088). Severity of disinhibition (sß = 0.218), agitation (sß = 0.199), and female sex (sß = 0.104) were associated with greater emotional burden. CONCLUSION: Our findings indicate that demographic characteristics and specific neuropsychiatric symptoms contribute differentially to domains of caregiver burden. Tailored interventions to support CPD are needed.

First impression of teeth design on others: A facial and personality analysis in the Central Indian population.

BACKGROUND: Facial features and personality types vary with different geographical boundaries, culture, and ethnicity. The impression created by teeth design differs with the face and personality of males and females. AIMS: This study evaluated the dominant facial and personality types and their correlation among males and females in Central Indian population. SUBJECTS AND METHODS: The full-face photographs of 120 people, with a broad smile and visible dentition, were calibrated to generate a facial map with digital software. The participants filled a personality questionnaire. Facial form and personality type were classified as a combination of strong, dynamic, delicate, and calm. Descriptive and inferential statistics using Chi-square and Kappa tests. RESULTS: The dominant facial form was calm (66.67%, 71.67%) with the second dominant facial form being dynamic (50%, 51.67%) both for males and females respectively. While the dominant personality type was dynamic (50%), the second dominant personality type was calm (35%, 30%) for both males and females. Kappa analysis showed moderate agreement between the dominant facial and personality types (P = 0.41 in males, P = 0.10 in females). The software used was SPSS 22.0 version and P < 0.05 is considered as the level of significance. CONCLUSIONS: A varying number of combinations are essential in characterizing the face. The personality type has a predominance of one type over other. The interpretation of these combinations in dentistry can help to select appropriate tooth forms and design a harmonious smile.

Deformation Induced Hierarchical Twinning Coupled with Omega Transformation in a Metastable ß-Ti Alloy.

Hierarchical twinning, at multiple length scales, was noted in a metastable body-centered cubic (bcc) ß-titanium alloy on tensile deformation. Site-specific characterization within the deformation bands, carried out using EBSD and TEM, revealed {332} <113> type primary bcc twins, containing different variants of secondary and tertiary twins, as well as the formation of stress-induced martensite (α"). Within the primary {332} <113> type twin, "destruction" of the prior quenched-in athermal ω phase was observed, while a stress-induced ω phase reforms within the tertiary twins, revealing the intricate nature of coupling between deformation twinning and displacive ω transformation.

Awareness, knowledge, and attitude of dental students toward infection control in prosthodontic clinic of a dental school in India.

BACKGROUND: Infection control practices are crucial and important elements in clinical dentistry as there is an increase in the prevalence of infectious diseases among dental patients. This necessitates the application of recommended procedures for infection control in dental schools and clinics. OBJECTIVES: The aim is to evaluate the awareness, knowledge, and attitude of the undergraduate dental students toward infection control measures in the prosthodontic clinic and to assess their satisfaction toward applying these measures during prosthodontic treatment. MATERIALS AND METHODS: A questionnaire-based study was conducted among 180 third, fourth and fifth year dental students (119 females and 61 males) in November 2015 in a private dental school of Rani Durgawati University, Jabalpur (Madhya Pradesh), India. It included 25 close-ended questions related to vaccination status and previous sharp injuries, awareness, knowledge, and attitude toward infection control in the prosthodontic clinic, previous education about infection control, and subjects' satisfaction with their knowledge and attitude. The questionnaire was distributed among 3rd, 4th, and 5th year students and informed consent were obtained before commencing the questionnaire. RESULTS: A total of 180 participants responded to the questionnaire. Their perception toward infection control practices in the prosthodontic clinic varied from 14.4% to 100%, where former were regularly disinfecting dental cast before sending it to the laboratory and later ones were regularly using gloves while attending the patient. Most of the subjects responded "good" or "fair" to the questions related to the evaluation of their knowledge and policy implementation of infection control in prosthodontic clinic (P < 0.0001). Around 47.8% were almost satisfied, and 28.9% were fairly satisfied with their knowledge and performance. CONCLUSIONS: The study findings showed inadequate attitude and awareness of subjects toward infection control in prosthodontic practice. Their self-assessment and satisfaction reflect their performance toward infection control policy.

Correction: Bio-catalytic nanocompartments for in situ production of glucose-6-phosphate.

Correction for 'Bio-catalytic nanocompartments for in situ production of glucose-6-phosphate' by M. Lomora et al., Chem. Commun., 2017, 53, 10148-10151.

Bio-catalytic nanocompartments for in situ production of glucose-6-phosphate.

Cells are sophisticated biocatalytic systems driving a complex network of biochemical reactions. A bioinspired strategy to create advanced functional systems is to design confined spaces for complex enzymatic reactions by using a combination of synthetic polymer assemblies and natural cell components. Here, we developed bio-catalytic nanocompartments that contain phosphoglucomutase protected by a biomimetic polymer membrane, which was permeabilized for reactants through insertion of an engineered α-hemolysin pore protein. These bio-catalytic nanocompartments serve for production of glucose-6-phosphate, and thus possess great potential for applications in an incomplete glycolysis, pentose phosphate pathway, or in plant biological reactions.

A closer look at the in vitro electrochemical characterisation of titanium alloys for biomedical applications using in-situ methods.

Titanium (Ti) and its alloys are widely used in several biomedical applications, particularly as permanent orthopaedic implants. Electrochemical testing provides a means to perform accelerated corrosion testing, however whilst results from polarisation testing for Ti and its alloys to date have been generally useful, they are also rather limited on the basis of several reasons. One reason is that the polarisation curves for Ti and its alloys in simulated body fluids all appear rather similar, and they do not present a classical 'breakdown' or pitting potential, making discrimination between alloys difficult. Of practical relevance however, are two key issues; (1) how do Ti alloys respond to a breakdown event? (i.e. do they readily 'repassivate'?), and, (2) what is that actual rate of Ti ion loss from exposure to physiological conditions? The answers to these questions are probed herein. Several Ti alloys of either unique composition or different fabrication method were studied, including commercially pure Ti (cp-Ti), Ti-6Al-4V, Ti-29Nb-13Ta-4.5Zr (TNTZ), selective laser melted Ti-6Al-4V, direct laser deposited cp-Ti, Ti-35Nb-15Zr, and Ti-25Nb-8Zr. Results reveal that both fabrication method and alloying influence 'repassivation' behaviour. Furthermore, atomic emission spectroelectrochemistry as applied to cp-Ti indicated actual dissolution currents of ∼2-3µA/cm-2 (i.e. ∼9µm/yr) in the range of the corrosion potential, also revealing such dissolution is persistent, even with cathodic polarisation, and definitively revealing that the presence of hydrogen peroxide and albumin activate anodic dissolution of Ti. STATEMENT OF SIGNIFICANCE: We believe the paper makes a significant and important contribution to the field of permanent implant biomaterials. Whilst we concede that the paper does not include any in vivo work, the timeliness of the work, and the completely new nature of the findings, we believe carries the impact required for Acta Biomaterialia. Key highlights include:All of the above combine to produce a manuscript that we believe has wide appeal, and can be used as both a port of reference to those working with Ti biomaterials, and also those wishing to apply useful characterisation techniques to their own work (with two very novel methods demonstrated herein, along with the unique information they provide).

In vitro and in vivo antioxidant, cytotoxic, and anti-chronic inflammatory arthritic effect of selenium nanoparticles.

The toxicity of selenium (Se) as an antioxidant supplement in the treatment of arthritis is debatable. In this study, Dextrin stabilized Se nanoparticles (SeNP) of size 64 nm ± 0.158 were used to explore its effects as a potent antioxidant with reduced toxicity in both in vitro and in vivo. In vitro toxicity of SeNP was determined using cytotoxicity assay. In vitro interactions of SeNP with DNA and protein was established. Subacute toxicity of SeNP was studied. Wistar rats with complete freunds adjuvant induced arthritis were used. Various concentrations of SeNP per kg body weight were fed orally daily upto to 21 days. Arthritic profile based on paw swelling, histopathological changes in joints, blood indices, and antioxidant enzymes level in organs such as liver, kidney, and spleen were investigated. Dextrin-SeNP when interacted with NIH-3T3 cells showed 15% cytotoxicity at 100 µg/mL whereas, bulk Se showed 95% at the same concentration. SeNP at 250 µg/mL showed protective effect on DNA. Interaction of SeNP with BSA showed increase in quenching of BSA fluorescence. SeNP did not show any subacute toxicity at concentration as high as 5 mg/kg b.w. in Wistar rats. SeNP at a concentration of 250 µg/kg b.w. acted as potent anti-inflammatory agent and significantly reduced (p < 0.05) arthritis induced parameters. The enzymatic antioxidant levels in liver, kidney, and spleen were restored significantly (p < 0.05) at 500 µg/kg b.w. while CRP was regained to normal at concentration of 100 µg/kg b.w. concluding SeNP at 500 µg/kg b.w. can be a potential antiarthritic drug supplement. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 993-1003, 2016.

Awareness and Knowledge of Undergraduate Dental Students about Sterilization/Disinfection Methods of Extracted Human Teeth.

BACKGROUND: Dental undergraduate students work on extracted human teeth in preclinical practical's to learn technical skills before entering the clinics and delivering dental care to the patients. AIM: The aim of the present investigation was to assess the awareness and knowledge toward sterilization/disinfection methods of extracted human teeth in a selected group of Indian dental students. MATERIALS AND METHODS: In this descriptive cross-sectional study, the participants consisted of 2nd-, 3rd-, 4th-, and 5th-year dental students. Data were collected by questionnaires and analyzed by Mann-Whitney U-test and Kruskal-Wallis test using SPSS software version 16 for Windows (SPSS Inc., Chicago, IL, USA). RESULTS: In this study, 235 dental students participated in the study. The average awareness and knowledge score was 7.27 (1.92). Based on the opinion of 57% (134/235) students, hydrogen peroxide was selected as the suitable material for sterilization and 24.6% (58/235) students believed that autoclave sterilization is a good way for the purpose. CONCLUSION: The results of this investigation indicated that awareness and knowledge of undergraduate dental students in relation to sterilization/disinfection methods of extracted human teeth were good. However, deficiencies were observed in relation to teaching the material and methods suitable for sterilization.

Rehabilitation of a mandibular segmental defect with magnet retained maxillofacial prosthesis.

Resection or loss of a portion of the mandible can result in a variety of functional, cosmetic and psychological deficits that are dependent on the extent of the defect, the concomitant therapy and the timing of rehabilitative efforts. These impairments greatly affect the patient's Quality of life (QOL). The thrust in cancer care is not simply on survival but on rehabilitation, which aims to improve multiple impairments and QOL. This article describes a case of a 58-year-old female with segmental resection of the anterior mandible, extending to lower lip, resulting in a large intraoral as well extra oral defect. Prosthodontics rehabilitation was done using a two-piece intra oral and extra oral prosthesis oriented to each other using magnets. Use of magnets for retaining the extra oral prosthesis simplifies the clinical and laboratory phase enhancing patient's comfort and psychological morale.

Scope of prosthodontic services for patients with head and neck cancer.

Patients with head and neck cancer face high morbidity due to the disease and its treatment and are affected on a variety of personal and physical levels. Maxillofacial prosthetics offer support for other disciplines in a multidisciplinary setting; can help to prevent / minimize the sequelae from disease and treatment, and offers the patient help in the rehabilitation process. Maxillofacial prosthodontics focuses on optimizing the disrupted rudimentary function of individuals whose rehabilitation will be a lifelong proposition. Normal function may not be achieved but optimal function should always be achieved and the patients can lead a near to normal life.

Acute respiratory distress syndrome due to Strongyloides stercoralis in non-Hodgkin's lymphoma.

Strongyloides stercoralis is a nematode endemic in tropical and subtropical regions. In immunocompetent subjects, pulmonary disease caused by the parasite is unremarkable but the same can be life threatening in immunocompromised subjects. Though described in literature it is rarely seen in Indian subjects. We report a patient with ARDS due to Strongyloides stercoralis complicating non-Hodgkin's lymphoma with neutropenia.

Atypical carcinoid tumour.

Carcinoid tumour is a rare entity accounting for less than two percent of bronchial neoplasms. The clinical presentation is highly variable and rarely, it may present as a solitary pulmonary nodule. More offten, it presents as a central endobronchial tumour. The peripheral type of carcinoid tumour is relatively rare.

Clinical profile of ARDS.

OBJECTIVES: Several studies have been published in western literature on incidence, prevalence, clinical course, outcome and mortality in patients with acute respiratory distress syndrome (ARDS). There are very few studies on the pattern of ARDS seen in Indian population. There are anecdotal reports of ARDS associated with different tropical diseases and the exact association of these life-threatening disorders with ARDS is not clearly described in the Indian literature. The study was carried out to identify the clinical pattern of Indian patients who died of ARDS. METHODS: This was a three and a half year retrospective study comprising of 98 patients who died of ARDS in the intensive care unit of Apollo Hospital, a tertiary care referral centre between January 1999 to June 2002. The present study looked at only those patients who died from ARDS and did not evaluate the clinical outcome or survival pattern of ARDS patients. The criteria used for diagnosis of ARDS was based upon American/European consensus statement for definition of acute lung injury (ALI) and ARDS. The patient demographic data consisted of age, sex, associated major illness in the part, clinical disorders associated with ARDS, length of hospital stay, use and duration of mechanical ventilation and the presence of sepsis and organ failure defined by ACCP/SCCM consensus conference definition. Seventy patients were ventilated with volume control mode and 28 patients with pressure control ventilation. Lung protective strategy was used in all the cases comprising of low tidal volumes at the rate of 5-ml/kg-body weight. Statistical analysis of the data was done by SPSS 10 for windows (SPSS, Inc., Chicago, Illinois). RESULTS: There were 98 patients during the study period who died of ARDS. Fifty one males and 47 female patients. Thirty patients had primary pulmonary infection, 18 had severe sepsis with multiorgan failure, 12 patients had polytrauma and 10 each had recent abdominal surgery and pancreatitis. Length of ICU stay was less than 10 days in 58 patients whereas in 40 patients it was more than 10 days. Duration of mechanical ventilation was less than seven days in 80 patients and more than seven days in 18 patients. Positive body fluid cultures were obtained in 42 out of 98 patients and of these, 14 patients had microbiological diagnosis established by blood culture, another 14 by endotracheal secretion culture, eight by urine culture and in the remaining six patients based upon wound cultures. The commonest organisms isolated from the body fluids were Pseudomonas and Klebsiella. CONCLUSION: Primary pulmonary infection was associated with ARDS is one-third of patients. Multiorgan failure was seen in 18% of patients who died from ARDS. Severe sepsis was identified as a significant risk factor for ARDS.

Pattern of lung cancer in elderly.

OBJECTIVES: The aim of the study was to evaluate the clinical spectrum of the lung cancer in the Indian patients. METHODS: All the patients above the age 60 years referred to the chest clinic of Apollo Hospitals, during the period 1989-2000 were evaluated for lung cancer with fibreoptic bronchoscopy, fluoroscopic guided transbronchial lung biopsy, transbronchial, needle aspiration and/or CT guided percutaneous fine needle aspiration biopsy. Retrospective data of 1400 patients was analyzed statistically. RESULTS: There were 512 patients (439 males, 73 females) with confirmed primary lung cancer. There were 62% ex-smokers, 10% current smokers and 28% non-smokers amongst males, whereas amongst females there were 10% ex-smokers and 90% non-smokers. Cough of more than 3 weeks duration was the commonest symptom seen in 85% (n = 435) followed by fever and weight loss. Radiologically the commonest feature was collapse-consolidation in 77% (n = 397). Central endobronchial tumours were seen in 204 patients (39.8%), whereas peripheral tumours were seen in 308 (60.2%). The diagnostic yield of transbronchial lung biopsy alone was as high as 48%, whereas the yield on CT guided percutaneous fine needle aspiration biopsy alone ranged from 32%-40%. There was no statistical difference in histological subtypes (non-small cell or small cell lung cancer) in the various groups studied. However, in those patients above the age of 80 years (group C) small cell lung cancer was more frequently seen. CONCLUSION: Primary lung cancer should always be suspected in elderly Indian subjects with unexplained cough and other constitutional symptoms of weight loss and fever.

A comparison of sputum examination for acid fast bacilli by modified Schaeffer & Fulton stain, Ziehl-Neelsen stain & cold stain.

A comparative study of Ziehl-Neelsen stain, cold stain and modified Schaeffer and Fulton stain was carried out to evaluate the efficiency of modified Schaeffer and Fulton method in sputum examination for acid fast bacilli (AFB). Of 187 sputum samples studied, 67 (35.82%) were reported positive by Ziehl-Neelsen stain and cold stain method while 66 (35.29%) were reported positive by modified Schaeffer and Fulton method. In comparison with Ziehl-Neelsen staining, 98.58 per cent positivity was reported by modified Schaeffer and Fulton method. Modified Schaeffer and Fulton method is found to be simple, reliable, less expensive and as efficient as Ziehl-Neelsen stain and cold stain for demonstration of acid fast bacilli in sputum.