An all phosphorene lattice nanometric spin valve

Phosphorene is a unique semiconducting two-dimensional platform for enabling spintronic devices integrated with phosphorene nanoelectronics. Here, we have designed an all phosphorene lattice lateral spin valve device, conceived via patterned magnetic substituted atoms of 3d-block elements at both ends of a phosphorene nanoribbon acting as ferromagnetic electrodes in the spin valve. Through First-principles based calculations, we have extensively studied the spin-dependent transport characteristics of the new spin valve structures. Systematic exploration of the magnetoresistance (MR) of the spin valve for various substitutional atoms and bias voltage resulted in a phase diagram offering a colossal MR for V and Cr-substitutional atoms. Such MR can be directly attributed to their specific electronic structure, which can be further tuned by a gate voltage, for electric field controlled spin valves. The spin-dependent transport characteristics here reveal new features such as negative conductance oscillation and switching of the sign of MR due to change in the majority spin carrier type. Our study creates possibilities for the design of nanometric spin valves, which could enable integration of memory and logic elements for all phosphorene 2D processors.

Knowledge, awareness and decision making of population visiting north indian institute towards dental implant as a treatment modality: a cross-sectional study

OBJECTIVES

The knowledge and awareness surrounding dental implants have significantly increased over the years, driven by advancements in technology, improved educational resources, and increased accessibility to dental care. Despite their widespread use, it is essential to assess the level of knowledge and awareness among patients regarding dental implants. The purpose of the present study is to measure the knowledge, awareness and decision making in dental implant therapy in North Indian population.

SETTINGS AND DESIGN

An analytical closed ended questionnaire based study.

METHODS

A cross-sectional well structured questionnaire survey was conducted amongst 300 out patients randomly either by interview or Google form to assess the knowledge and awareness about dental implant as a treatment modality. There were seven questions which were close ended multiple choice type concerning patient knowledge and 10 questions for assessing awareness and decision making towards dental implants. Date was collected and descriptive analysis was done.

RESULTS

43.67 % of population was either well informed or moderately informed about replacement of missing teeth. For replacement of missing tooth, most of them (83 %) had the knowledge of dental implant therapy. Dentist was the main source of information about implants. 90.67 % studied population believed that implants provide better treatment because of increased chewing efficiency of implants as compared to removable partial dentures or fixed partial dentures. 86.67 % patients thought that implantologist is better qualified that general dental surgeon. 94 % patients were keen to know more about implants. There is non-significant difference in knowledge and awareness as well as decision making for males and females (p<0.05).

CONCLUSION

People have partial knowledge about dental implants and there is need of spreading awareness about implant therapy in the region. Dentist plays a crucial role for dissemination of knowledge. Cost is a constraining factor for this implant therapy to be chosen as a treatment modality.

Strain-controlled spin transport in a two-dimensional (2D) nanomagnet

Semiconductors with controllable electronic transport coupled with magnetic behaviour, offering programmable spin arrangements present enticing potential for next generation intelligent technologies. Integrating and linking these two properties has been a long standing challenge for material researchers. Recent discoveries in two-dimensional (2D) magnet shows an ability to tune and control the electronic and magnetic phases at ambient temperature. Here, we illustrate controlled spin transport within the magnetic phase of the 2D semiconductor CrOBr and reveal a substantial connection between its magnetic order and charge carriers. First, we systematically analyse the strain-induced electronic behaviour of 2D CrOBr using density functional theory calculations. Our study demonstrates the phase transition from a magnetic semiconductor → half metal → magnetic metal in the material under strain application, creating intriguing spin-resolved conductance with 100% spin polarisation and spin-injection efficiency. Additionally, the spin-polarised current-voltage (I-V) trend displayed conductance variations with high strain-assisted tunability and a peak-to-valley ratio as well as switching efficiency. Our study reveals that CrOBr can exhibit highly anisotropic behaviour with perfect spin filtering, offering new implications for strain engineered magneto-electronic devices.

Gender differences in COVID-19 knowledge, risk perception, and public stigma among the general community: Findings from a nationwide cross-sectional study in India

Introduction

Individual and community characteristics predictive of knowledge, perception, and attitude on COVID-19, specifically on gender, have not been adequately explored.

Objective

To examine the gender differences in COVID-19 knowledge, self-risk perception and public stigma among the general community and to understand other socio-demographic factors which were predictive of them.

Method

A nationally representative cross-sectional multi-centric survey was conducted among adult individuals(≥18 yrs) from the community member (N = 1978) from six states and one union territory of India between August 2020 to February 2021. The participants were selected using systematic random sampling. The data were collected telephonically using pilot-tested structured questionnaires and were analyzed using STATA. Gender-segregated multivariable analysis was conducted to identify statistically significant predictors (p < 0.05) of COVID-19-related knowledge, risk perception, and public stigma in the community.

Results

Study identified significant differences between males and females in their self-risk perception (22.0% & 18.2% respectively) and stigmatizing attitude (55.3% & 47.1% respectively). Highly educated males and females had higher odds of having COVID-19 knowledge (aOR: 16.83: p < 0.05) than illiterates. Highly educated women had higher odds of having self-risk perception (aOR: 2.6; p < 0.05) but lower public stigma [aOR: 0.57; p < 0.05]. Male rural residents had lower odds of having self-risk perception and knowledge [aOR: 0.55; p < 0.05 & aOR: 0.72; p < 0.05] and female rural residents had higher odds of having public stigma [aOR: 1.36; p < 0.05].

Conclusion

Our study findings suggest the importance of considering thegender differentials and their background, education status and residential status in designing effective interventions to improve knowledge and reduce risk perception and stigma in the community about COVID-19.

Stress analysis in implant, abutment, and peripheral bone with different restorative crown and abutment materials: A three-dimensional finite element analysis study

Background

Stresses on prosthetic crown directly influences the survival rate of implants hence it should be considered while selecting prosthetic material.The aim of the study is to evaluate stress analysis on implant, abutment and peripheral bone with change in different abutment and different crown materials by 3D finite element study.

Materials and Methods

A numerical procedure based on finite element method was adopted to investigate the influence of different prosthetic materials and abutment materials on stress situation. Eight different three-dimensional (3D) models of a bone-level implant system and an abutment were created by using the standard tessellation language (STL) data of original implant components. Combinations included of abutment materials i.e., Titanium (Ti), Polyetheretherketone (PEEK), Polyetherketoneketone (PEKK), Polymer infilterated hybrid ceramic (TZI) along with different restoration materials Monolithic Zirconia (MZ) and lithium disilicate glass ceramic (IPS e-max). In each model, the implants were loaded obliquely (150 N). The stress distribution in the implant, Abutment and peripheral bone was evaluated through the von Mises stress analysis.

Results

Higher stresses were found on neck of implants irrespective of abutment material and restorative material. Highest stress was found with PEEK material. The pattern of stress distribution in implant and peripheral bone was similar in all models.

Conclusion

There is no difference in stresses with the change in restorative material but the change in abutment material has effect on stresses on implants.

Stress distribution in bone around an implant-supported three-unit fixed dental prosthesis using two different computer-aided designing/computer-aided milling provisional crown materials: Milled polymethylmethacrylate and milled polyetheretherketone - A finite element analysis

Background

Occlusal loading of osseointegrated implants is believed to be an essential determining factor in the long-term success of an implant treatment. Numerous studies have been conducted on the evaluation of stress distribution by definitive restoration materials for Implant-supported fixed prosthesis, but very few have evaluated provisional restoration materials for the same. This study aims to evaluate the influence of provisional restoration material - Milled Polymethylmethacrylate (PMMA) and Milled Polyetheretherketone (PEEK), over stress distribution on the peri-implant bone around an implant-supported three-unit, fixed dental prosthesis using finite element analysis method.

Materials and Methods

Three-dimensional models of a pair of bone-level implant system and titanium base abutments were created using the standard tessellation language data of original implant components. A bone block representing the mandibular posterior area was created, and the implants were placed in the bone block with 100% osseointegration in the 2nd premolar to 2nd molar region. A superstructure of an implant-supported 3-unit bridge was modeled on top of the abutments, each crown to be 8 mm in height and with an outer diameter of 6 mm in 2nd premolar region and 10 mm in 1st molar and 2nd molar region. Two different models were created according to combinations of provisional restoration materials, namely, Milled PMMA and Milled PEEK based on. In each model, the implants were loaded vertically (300 N) and obliquely (150 N at 30°). The stress distribution in the cortical bone, cancellous bone, and implant was evaluated through the von Mises stress analysis.

Results

The results showed no difference in stress distribution due to the different provisional restorations - Milled PMMA and Milled PEEK. In addition, the vertical load resulted in higher stress values in the implant components, cortical bone, and cancellous bone in both PEEK and PMMA models as compared to oblique loading.

Conclusion

The new polymer, PEEK was seen to provide comparable stress generation in the current study without exceeding the physiological limits of peri-implant bone. Thus, it can be considered as a good alternative to PMMA resin as a provisional crown material since it provides certain additional benefits.

Factors associated with COVID-19 stigma during the onset of the global pandemic in India: A cross-sectional study

Objective

To assess factors associated with COVID-19 stigmatizing attitudes in the community and stigma experiences of COVID-19 recovered individuals during first wave of COVID-19 pandemic in India.

Methods

A cross-sectional study was conducted in 18 districts located in 7 States in India during September 2020 to January 2021 among adults > 18 years of age selected through systematic random sampling. Data on socio demographic and COVID-19 knowledge were collected from 303 COVID-19 recovered and 1,976 non-COVID-19 infected individuals from community using a survey questionnaire. Stigma was assessed using COVID-19 Stigma Scale and Community COVID-19 Stigma Scale developed for the study. Informed consent was sought from the participants. Univariate and multivariate binary logistic regression analysis were conducted.

Results

Half of the participants (51.3%) from the community reported prevalence of severe stigmatizing attitudes toward COVID-19 infected while 38.6% of COVID-19 recovered participants reported experiencing severe stigma. Participants from the community were more likely to report stigmatizing attitudes toward COVID-19 infected if they were residents of high prevalent COVID-19 zone (AOR: 1.5; CI: 1.2-1.9), staying in rural areas (AOR: 1.5; CI:1.1-1.9), belonged to the age group of 18-30 years (AOR: 1.6; CI 1.2-2.0), were male (AOR: 1.6; CI: 1.3-1.9), illiterate (AOR: 2.7; CI: 1.8-4.2), or living in Maharashtra (AOR: 7.4; CI: 4.8-11.3). COVID-19 recovered participants had higher odds of experiencing stigma if they had poor knowledge about COVID-19 transmission (AOR: 2.8; CI: 1.3-6.3), were staying for 6-15 years (AOR: 3.24; CI: 1.1-9.4) in the current place of residence or belonged to Delhi (AOR: 5.3; CI: 1.04-26.7).

Conclusion

Findings indicated presence of stigmatizing attitudes in the community as well as experienced stigma among COVID-19 recovered across selected study sites in India during the first wave of COVID-19 pandemic. Study recommends timely dissemination of factual information to populations vulnerable to misinformation and psychosocial interventions for individuals affected by stigma.

Antibacterial activity and mechanism of essential oils in combination with medium-chain fatty acids against predominant bovine mastitis pathogens

Bovine mastitis has become a significant economic importance for dairy industry. Concerns regarding poor milk quality, and emergence of bacterial resistance has necessitated to develop alternative therapeutic approach to antibiotics for treatment of mastitis. Saturated medium-chain fatty acids (MCFAs) and essential oils (EOs) are known natural antimicrobials, but their combined effect has not been investigated extensively. The objective of the present investigation was to examine the bactericidal effect of various combined treatments of eight EOs and three saturated MCFAs to inactivate predominant mastitis pathogens, including Staphylococcus aureus ATCC 29213; Escherichia coli ATCC 25922; Klebsiella pneumoniae ATCC 27736; and Streptococcus agalactiae ATCC 27956. The minimum inhibition concentration (MIC) values confirmed that all the tested pathogens were variably susceptible to both EOs and saturated MCFAs. Among essential oils, carvacrol (CAR), trans-cinnamaldehyde (TC), and thymol (TM) showed highest inhibitory activity at concentration 0.38-1.32 mg/mL. Carvacrol exhibited effective additive antibacterial activity in combined treatment with octanoic acid (OA) in terms of its fractional inhibitory index (0.63-0.88) and time-kill effect in reducing about 6 log CFU/mL bacterial cells in less than 5 min. Effort was also made to elucidate mechanism of antibacterial action of CAR and OA against selected mastitis pathogens by observing changes in cell microstructure, permeability and integrity of cell membrane and their membrane potential. After adding CAR and OA at MIC level, there were obvious changes in cell morphology, leakage of small electrolytes, and macromolecules at the initial few hours of treatment i.e. within 1-2 h were observed. Our results indicated that CAR and OA could be evaluated as alternatives or adjuncts to antibiotics as intramammary infusion or topical application to treat bovine mastitis, significantly improving the microbiological safety of milk.

Differentiating acute from chronic insomnia with machine learning from actigraphy time series data

Acute and chronic insomnia have different causes and may require different treatments. They are investigated with multi-night nocturnal actigraphy data from two sleep studies. Two different wrist-worn actigraphy devices were used to measure physical activities. This required data pre-processing and transformations to smooth the differences between devices. Statistical, power spectrum, fractal and entropy analyses were used to derive features from the actigraphy data. Sleep parameters were also extracted from the signals. The features were then submitted to four machine learning algorithms. The best performing model was able to distinguish acute from chronic insomnia with an accuracy of 81%. The algorithms were then used to evaluate the acute and chronic groups compared to healthy sleepers. The differences between acute insomnia and healthy sleep were more prominent than between chronic insomnia and healthy sleep. This may be associated with the adaptation of the physiology to prolonged periods of disturbed sleep for individuals with chronic insomnia. The new model is a powerful addition to our suite of machine learning models aiming to pre-screen insomnia at home with wearable devices.

Development & validation of scales to assess stigma related to COVID-19 in India

Background & objectives

COVID-19 pandemic has triggered social stigma towards individuals affected and their families. This study describes the process undertaken for the development and validation of scales to assess stigmatizing attitudes and experiences among COVID-19 and non-COVID-19 participants from the community.

Methods

COVID-19 Stigma Scale and Community COVID-19 Stigma Scale constituting 13 and six items, respectively, were developed based on review of literature and news reports, expert committee evaluation and participants' interviews through telephone for a multicentric study in India. For content validity, 61 (30 COVID-19-recovered and 31 non-COVID-19 participants from the community) were recruited. Test-retest reliability of the scales was assessed among 99 participants (41 COVID-19 recovered and 58 non-COVID-19). Participants were administered the scale at two-time points after a gap of 7-12 days. Cronbach's alpha, overall percentage agreement and kappa statistics were used to assess internal consistency and test-retest reliability.

Results

Items in the scales were relevant and comprehensible. Both the scales had Cronbach's α above 0.6 indicating moderate-to-good internal consistency. Test-retest reliability assessed using kappa statistics indicated that for the COVID-19 Stigma Scale, seven items had a moderate agreement (0.4-0.6). For the Community COVID-19 Stigma Scale, four items had a moderate agreement.

Interpretation & conclusions

Validity and reliability of the two stigma scales indicated that the scales were comprehensible and had moderate internal consistency. These scales could be used to assess COVID-19 stigma and help in the development of appropriate stigma reduction interventions for COVID-19 infected, and mitigation of stigmatizing attitudes in the community.

Efficacy and mechanism of carvacrol with octanoic acid against mastitis causing multi-drug-resistant pathogens

In the present investigation, we determined the in vitro antimicrobial activity of eight essential oils (EOs) and three medium-chain fatty acids (MCFAs) alone and in combination against Staphylococcus aureus ATCC 700698, Klebsiella pneumoniae ATCC 700603, and E. coli FcW5. The interactions between EOs and MCFAs were determined by fractional inhibitory concentration indices. Moreover, mode of action of selected bioactive components was studied by changes in bacterial surface charge, morphology, and membrane integrity assays. Among EOs, carvacrol (CAR), trans-cinnamaldehyde (TC), and thymol (TM) showed strong antimicrobial activity. In combination study, CAR+OA (octanoic acid), CAR+DA (decanoic acid), and TM+OA were observed as the most significant (P≤0.05) which were also confirmed through time-kill plots. Based on these results, CAR+OA were found to be most efficacious in terms of killing time (P≤0.05). Changes in the surface charge, morphology, and membrane integrity upon the combined treatment of CAR+OA were also observed, which ultimately leads to cell death. Results suggest that CAR+OA when used in combination offer a significant (P≤0.05) additive antimicrobial activity against the selected pathogenic bacteria. Therefore, these natural bioactive molecules could be interesting alternatives to conventional therapy for the control of mastitis caused by multi-drug-resistant pathogens in bovine animals to ensure the milk safety.

Effect of yoga on depression in hypothyroidism: A pilot study

Background

The prevalence of hypothyroidism among Indian women is 15.8%. Depression is frequently reported in hypothyroidism. Yoga is an effective intervention for depression. However, the influence of yoga on depression in patients with hypothyroidism has not been studied.

Aim

The present study investigated the effect of a 3-month integrated yoga intervention (3-IY) on depression, lipid indices, and serum thyroid-stimulating hormone (sTSH) levels among female patients having hypothyroidism, and mild-to-moderate depression.

Method

The present single-arm pre-post design study was conducted in thirty-eight women (average age 34.2 ± 4.7 years). Participants received a 3-IY comprising asanas, pranayama, and relaxation techniques for 60 min daily (5 days a week). Depression, sTSH, lipid profile indices, Body Mass Index (BMI), fatigue, anxiety, and stress were assessed at baseline and after 12 weeks. Thyroid medication was kept constant during the study period. Data were analysed using R Studio software.

Result

A significant (P < 0.05) reduction in depression (58%), sTSH (37%), BMI (6%), fatigue (64%), anxiety (57%), lipid profile indices (HLD increased significanty), and stress (55%) levels was observed after 3 months, compared with the corresponding baseline levels.

Conclusion

The 3-IY is useful for reducing depression, dyslipidemia, and sTSH in women with hypothyroidism and depression. Further studies with a larger sample size and a robust research design using objective variables must be conducted to strengthen the study findings.

Viscosity prediction of Pongamia pinnata (Karanja) oil by molecular dynamics simulation using GAFF and OPLS force field

The increasing concern on the harmful effects caused by mineral oil-based lubricants towards the environment has given impetus to the evolution of green-lubricants. Vegetable oils are highly biodegradable, renewable, and possesses good lubricating property. In the present study Pongamia pinnata, non-edible vegetable oil, also known as Karanja Oil (KO) was used as the base oil for a lubricant. The preliminary properties, such as fatty acid profile and viscosity, which has a vital role in governing the performance of lubricants were evaluated experimentally as per international standards. The shear viscosity of KO which constitutes 8 major fatty acids were predicted using non-equilibrium molecular dynamics (NEMD) and periodic perturbation (PP) method using Optimised Potentials for Liquid Simulations (OPLS) and Generalized Amber Force Field (GAFF). The shear viscosities were evaluated at temperatures ranging from 313K to 373 K and pressure P = 0.1 MPa. The experimental and simulation data of KO shear viscosity are in line with each other using OPLS. The kinematic viscosities were calculated using the shear viscosities and densities obtained from simulation. The variation between experimental and simulation data is less while using OPLS, while GAFF force fields resulted in higher deviations.

Spin-selective response tunability in two-dimensional nanomagnet

Recent reports on the two-dimensional (2D) material CrOCl revealed magnetic ordering and spin polarisation with Curie TemperatureTc∼ 160 K, values higher than most diluted magnetic semiconductors. Here, we investigate the uniaxial and biaxial strain-dependent electronic and transport properties of CrOCl monolayer using first-principles based calculations. The calculated Young's modulus indicates high mechanical flexibility for the application of high strain. Our study shows that strain can induce phase changes from a bipolar magnetic semiconductor → half metal → magnetic metal in the material, leading to interesting spin-resolved conductance with 100% spin filtering. Furthermore, the current-voltage (I-V) response showed conductance fluctuations, characterised by peak to valley ratio and switching efficiency offering high strain assisted tunability. Overall, CrOCl shows a highly anisotropic behaviour with the material displaying 100% spin polarisation in the tensile strain region. The electronic, transport and mechanical properties indicate that CrOCl is a versatile 2D material with multi-phase capabilities having promising applications for future nanospintronic devices.

Bi-stimuli assisted engineering and control of magnetic phase in monolayer CrOCl

Magnetic phase control and room temperature magnetic stability in two-dimensional (2D) materials are indispensable for realising advanced spintronic and magneto-electronic functions. Our current work employs first-principles calculations to comprehensively study the magnetic behaviour of 2D CrOCl, uncovering the impact of strain and electric field on the material. Our studies have revealed that uniaxial strain leads to the feasibility of room temperature ferromagnetism in the layer and also detected the occurrence of a ferromagnetic → antiferromagnetic phase transition in the system, which is anisotropic along the armchair and zigzag directions. Beyond such a strain effect, the coupling of strain and electric field leads to a remarkable enhancement of the Curie temperature (T_c) ∼ 450 K in CrOCl. These predictions based on our detailed simulations show the prospect of multi-stimuli magnetic phase control, which could have great significance for realizing magneto-mechanical sensors.

1048 Prevalence Of Positional Obstructive Sleep Apnea (OSA) In Patients With OSA-COPD Overlap Syndrome

Introduction

Positional OSA (non-supine apnea-hypopnea index [AHI] &lt; 5 events/hr) is present in 30% of patients with OSA. We demonstrated that in patients with OSA- COPD overlap syndrome the AHI inversely correlated with the degree of gas trapping, suggesting a stabilizing effect on the upper airway. We hypothesized that sleep position would be less important, resulting in a lower prevalence of positional OSA.

Methods

Patients underwent a polysomnogram that demonstrated OSA (AHI &gt; 5 events/hr). To confirm COPD, patients had spirometry performed and a chest computed tomography for measurements of percent gas trapping.

Results

Sixteen patients [6 (38%) males, 55±7 years/old, FEV1 1.2±0.5 L, FEV1 % Predicted 45±19%, FVC 2.3±0.8 L, FVC % Predicted 69±20%, FEV1/FVC 51±12%, BMI 33±9 kg/m2)] were diagnosed with OSA (AHI 15±12 events/hour). Four patients (25%) had positional OSA (AHI 13±6 events/hr, non-supine AHI 1±1 event/hr) compared to 12 patients who were non-positional [AHI 16±13 events/hr (p=0.95)]. There was no difference in age [52±8 and 56±7 yrs (p=0.3)] or severity of obstruction in those with and without positional OSA [FEV1 1.4±4 L and 1.1±0.5 L, (p=0.3), FEV1 % predicted 50±17% and 44±20%, (p=0.7), FVC 2.9±0.8 L and 2.1±0.8 L (p=0.1), FVC % predicted 78±21% and 66±20%, (p=0.3), and FEV1/FVC 50±11% and 51±12%, (p=0.8), respectively]. However, patients with positional OSA were less heavy than those with non-positional OSA [BMI 23±3 and 37±8 kg/m2, respectively (p=0.005)]. Finally, there was no difference in the CT-Derived % Gas Trapping in those with and without positional OSA [48±37% and 36±25%, (p=0.6), respectively].

Conclusion

The prevalence of positional OSA in patients with OSA-COPD overlap is similar to OSA patients without COPD. Despite the presence of obstructive disease and gas trapping that may affect upper airway stability, other factors including body position and BMI remain important determinants for developing OSA in patients with COPD.

Support

R01-HL089856, R01-HL089897

0567 Hypoxic Burden and Apnea-Hypopnea Duration in Patients with Positional Obstructive Sleep Apnea

Introduction

Recently, the measurement of the hypoxic burden and apnea-hypopnea duration has been shown to correlate with mortality in patients with obstructive sleep apnea (OSA). We hypothesized that in patients with mild positional OSA (apnea-hypopnea index [AHI] &lt; 5 events/hr in the non-supine position) the hypoxic burden would be increased and apnea-hypopnea duration shortened and similar to patients with non-positional OSA.

Methods

Fourteen patients with positional OSA and 24 patients non-positional OSA with similar severity of OSA based on the respiratory event index (REI) were included. All patients had a home sleep apnea test for suspected OSA. The hypoxic burden was calculated by the multiplication of REI and the mean area under the desaturation curves.

Results

Thirty-eight patients [12 (35%) males, 50±12 yrs, BMI 35±7 kg/m2, Epworth Sleepiness Scale (ESS) 11±8, REI 10±3 events/hr, apnea-hypopnea duration 19±4 sec, mean SaO2 94±2%, lowest SaO2 79±8%, % total sleep time (TST) SaO2 &lt; 90% 11±16%, hypoxic burden 30±17 %min/hr] completed the study. Fourteen patients [9 (64%) males, 46±14 yrs, BMI 31±6 kg/m2, ESS 7±5, REI 9±3 events/hr, mean SaO2 94±2%, lowest SaO2 81±6%, %TST SaO2 &lt; 90% 4±6%] had positional OSA (supine REI 16±7 events/hr, non-supine REI 3±1 events/hr) and 24 patients had non-positional OSA [3 (13%) males, 52±10 yrs, BMI 38±7 kg/m2, ESS 12±9, REI 10±3 events/hr, mean SaO2 94±2%, lowest SaO2 77±9%, %TST SaO2 &lt; 90% 14±19%]. The hypoxic burden was elevated in both the positional and non-positional OSA patients with no difference between the groups (26±19 %min/hr and 32±15 %min/hr, respectively, p=0.13). The apnea-hypopnea duration was similar in positional and non-positional OSA patients (20±3 sec and 18±4 sec, respectively, p=0.08 sec).

Conclusion

In patients with mild positional OSA the hypoxic burden, which has been associated with cardiovascular mortality, is elevated and similar to patients with non-positional OSA.

Support

None

0610 Prevalence of Positional Obstructive Sleep Apnea Based on 3% Vs 4% Oxygen Desaturation Using Home Sleep Apnea Testing

Introduction

Approximately 30% of patient with obstructive sleep apnea (OSA) have positional OSA [non-supine apnea-hypopnea index (AHI) &lt; 5 events/hr]. However, the prevalence is based on variable definitions for hypopneas related to the degree of oxygen desaturation. In addition, use of a home sleep apnea test (HSAT) to identify positional OSA is limited. We hypothesized that in patients evaluated with an HSAT, using a definition for hypopneas based on 4% compared to 3% oxygen desaturation will significantly decrease the percentage diagnosed with positional OSA.

Methods

Fourteen patients with positional OSA based on a non-supine respiratory event index (REI) &lt; 5 events/hr were included. The initial diagnosis was determined based on a hypopnea definition of ≥ 3% oxygen desaturation. The studies were reanalyzed using a hypopnea definition of ≥ 4% oxygen desaturation.

Results

Fourteen patients [9 (64%) males, 46±14 yrs, BMI 31±6 kg/m2, ESS 7±5, REI 9±3 events/hr, mean SaO2 94±2%, lowest SaO2 81±6%, %TST SaO2 &lt; 90% 4±6%] were identified with positional OSA (supine REI 16±7 events/hr, non-supine REI 3±1 events/hr) using a hypopneas definition of ≥ 3% oxygen desaturation. When reanalyzed using a hypopnea ≥ 4% oxygen desaturation there was a significant decrease in the REI to 7±2 events/hr (p&lt;0.001). Three patients (21%) no longer were considered to have OSA. These patients were younger (32±14 vs. 50±11yrs, p=0.03) and had less severe OSA (REI 6±1 vs. 9±3 events/hr (p=0.04), but there was no difference in BMI (32±11 vs. 31±5 kg/m2, p=0.9) or mean and lowest SaO2 (96±0.4 vs. 94±2%, p=0.13, and 82±8 vs. 81±6%, p=0.9, respectively).

Conclusion

In patients with mild positional OSA, using a hypopnea definition of at least 4% vs. 3% oxygen desaturation on a HSAT will have a significant effect on the overall REI and often exclude patients who would otherwise be treated for OSA.

Support

None.

Comparative evaluation of crestal bone levels around endosseous implants as influenced by conventional and diode laser during second-stage surgery in mandibular implant-supported overdenture: An in vivo study

Aim:

This study aims to evaluate and compare the crestal bone levels around implants as influenced by conventional and diode laser during second-stage surgery in an edentulous mandible using cone beam computed tomography (CBCT) and digital radiography (DR).

Settings and Design:

A split-mouth in vivo prospective study on edentulous patients involving placement of two implants in mandible followed by the comparison of two different techniques for second-stage surgery.

Materials and Methods:

The study was undertaken to evaluate the crestal bone change around 16 implant sites distributed in two groups (eight implants each) following two methods during second-stage surgery, i.e., Group 1 - Conventional second stage and Group 2 - Diode laser. Measurements were made on two sides (mesial and distal) using intraoral periapical and four sides (labial, lingual, mesial, and distal) using CBCT scans for both groups. These measurements were conducted at two time intervals for both, i.e., immediately after implant loading and twenty 4 weeks after implant loading. The values obtained were subjected to statistical analysis.

Statistical Analysis Used:

The normality of data was checked by Shapiro–Wilk's test. Intragroup comparison was compared using independent t-test by post hoc comparison by Bonferroni method (P < 0.05).

Results:

Crestal bone loss at the time of loading for Group 1 evaluated by CBCT was 0.950 ± 0.988 while after 24 weeks of loading, it was 1.388 ± 0.576. For Group 2, mean crestal bone loss was 1.200 ± 0.925 at the time of loading, and after 24 weeks, it was 1.512 ± 0.674. Crestal bone loss at the time of loading for Group 1 evaluated by DR was 1.075 ± 0.849 while after 24 weeks of loading, it was 1.562 ± 0.480. For Group 2, mean crestal bone loss was 1.162 ± 0.833 at the time of loading and after 24 weeks, it was 1.700 ± 0.498.

Conclusions:

In the present study, no statistically significant difference was observed in crestal bone loss between conventional and diode laser technique.

High efficiency spin filtering in magnetic phosphorene

We present high efficiency spin filtering behaviour in magnetically rendered phosphorene, doped with various 3d block elements. A phase diagram was obtained depicting the presence of various electronic and magnetic states.

Two-dimensional C3N based sub-10 nanometer biosensor

The current observation demonstrates the usefulness of the two-dimensional C₃N system as a next generation bio-sensor for the sequencing of various nucleobases, offering new leads for future developments in bioelectronics, superior sensing architectures and sustainable designs.

Quantification of picric acid on nanosphere polypyrrole modified electrode by stripping voltammetric method

The electrochemical studies of picric acid were carried out in acidic, neutral and basic buffer media at bare glassy carbon (GC) and polypyrrole modified GC electrode. Cyclic Voltammogram (CV) of picric acid exhibited three reduction peaks at -0.4, -0.8 and -1.5V (vs. Ag/AgCl) and two oxidation peaks at 0.8 and 1.4V (vs. Ag/AgCl). Among the various pH studied, highly sensitive response was observed at pH 1.0. The effect of scan rate was studied between 25 and 500 mVs-1 at the optimal pH.CV results revealed the adsorption-controlled reaction at the electrode surface. The GC electrode was modified with polypyrrole conducting polymer film to enhance the electrocatalytic activity of the reductive species. Atomic force microscopy (AFM) images showed the nanosphere morphology of the polypyrrole film, which was coated uniformly on the electrode surface. Under optimum experimental conditions, the influence of concentration on the stripping signal was studied. The linear range of detection was found between 50 ppb and 250 ppb with the lower limit of detection of 10±3 ppb.

Acceleration of Swiss cheese ripening by microbial lipase without affecting its quality characteristics

The effect of exogenous microbial lipase enzyme on the ripening of Swiss cheese (0, 200, and 800U lipase in 30 L milk) was investigated for the physico-chemical, textural and sensory properties, along with its microstructure. The aim of this study was to investigate the application of microbial lipase to accelerate the ripening without affecting its original desirable quality characteristics. The effect of the microbial lipase was studied at different time periods (2, 30, 45, and 60 days) of the Swiss cheese ripening stages. Statistical analysis of the results showed that the physico-chemical parameters of cheese slightly increased during the ripening. Also, at all stages of the ripening hardness of Swiss cheese increased while the brittleness decreased. The number and size of the fat globules were also affected by the addition of the lipases. This study also showed that increase in the lipase amount had no significant change in quality and sensory parameters. Therefore, 200U of lipase was found to be sufficient to reduce the ripening time from 90 to 60 days by maintaining its genuine quality. Thus, this study suggested that the addition of microbial lipase may significantly reduce the cost of the cheese production by lowering the ripening period by 1 month and maintaining the quality of the final product.

CHANGES IN IRISIN RELEASE IN RESPONSE TO PERIPHERAL KISSPEPTIN-10 ADMINISTRATION IN HEALTHY AND OBESE ADULT MEN

Context

Kisspeptin role in metabolism has been implicated recently. However, the nature of the signals that may connect body fat/muscle tissues with the central nervous system governing energy homeostasis remains to be elucidated.

Objective

The present study was designed to investigate the effects of peripheral kisspeptin-10 administration on irisin release in human males.

Subjects and methods

Kisspeptin-10 was administered to normal weight (n=8) and obese (n=8) men. Sequential blood sampling was performed for 30 minutes pre and 210 minutes post kisspeptin injection at 30 minutes interval. ELISA kit was used to detect plasma irisin levels.

Results

There is a significant (P<0.0001) effect of Kisspeptin-10 administration on irisin release in both normal weight and obese participants. Mean irisin levels (96.24 ± 1.351 ng/mL) at 210 minutes were significantly (P<0.0001) enhanced as compared to pre-kisspeptin (59.18 ± 4.815 ng/mL) in normal weight subjects. In obese subjects mean irisin levels (75.76 ± 4.06 ng/mL) were significantly (P<0.0001) elevated at 180 minutes post-kisspeptin when compared with pre-kisspeptin irisin levels (41.28 ± 2.89 ng/mL).

Conclusion

Our findings suggest that kisspeptin may have a novel therapeutic potential to induce irisin release in humans which may have anti-obesity effects.

Comparative Evaluation of Shear Bond Strength of Newer Resin Cement (RelyX Ultimate and RelyX U200) to Lithium Disilicate and Zirconia Ceramics as Influenced by Thermocycling

Background/Purpose:

The purpose of this study was to compare the shear bond strength of high strength ceramics to cut dentine as influenced by different resin cement types after thermocycling.

Materials and Methods:

Shear bond strength testing was carried out for 56 sound, freshly extracted first permanent molars. Specimens were divided at random into 2 groups (n = 28) Lithium disilicate and Zirconia. Lithium disilicate and Zirconia specimens were further subdivided depending upon luting with Rely X ultimate cement bonded with single bond universal adhesive and Rely X U200 cement. Half of the specimens of each material luted with cements were subjected to thermocycling. Shear bond strength was evaluated using Universal testing machine at a crosshead speed of 5 mm/min. Results were compared and evaluated using t-test at a significance level of 0.05. The nature of bond failure was observed under a stereomicroscope for each sample.

Results:

The mean difference of Lithium disilicate test specimens bonded with Rely X ultimate cement bonded with single bond universal adhesive with and without thermocycling was found to be 42.95+/-17.41MPa and 120.62+/-56.46 MPa respectively. The mean difference of Zirconia test specimens with Rely X ultimate cement bonded with single bond universal adhesive, with and without thermocycling, was found to be 8.74+/-2.90 MPa and 164.28+/-43.78 MPa respectively. The mean difference of Lithium disilicate test specimens bonded with Rely X U200 with and without thermocycling was found to be 2.36+/-0.63 MPa and 36.79.62+/-17.21MPa respectively. The mean difference of Zirconia test specimens bonded with Rely X U200 with and without thermocycling was found to be 5.96+/-3.11MPa and 122.46+/-23.01MPa respectively.

Conclusion:

Zirconia was found to have better shear bond strength than Lithium discilicate. The use of single bond universal adhesive improves bonding to newer higher strength ceramics such as Zirconia. Cohesive failure was predominant at cement dentine interface.

Effectiveness of TB sensitization initiatives in improving the involvement of self help group members in rural TB control in south India

Background

The 'End TB strategy' has highlighted the importance of inter-sectoral collaboration and community mobilization for achieving zero TB deaths by 2020.

Objective

The aim of the study was to develop and test a model TB sensitization programme involving self help groups (SHGs).

Methodology

This experimental study was conducted in two blocks (intervention and control), in Tiruvallur district. The intervention content included short-lecture, musical story telling activity, role play, short film on TB. The impact was compared at baseline, third and sixth months in terms of SHGs' awareness, promotion of awareness, identification and referral of presumptive TB cases and provision of TB treatment.

Results

A total of 764 vs 796 SHGs were enrolled in control and intervention groups, respectively. The knowledge attitude, and practice score (lower score indicated a better attitude and practice), from baseline to 6 months was significantly reduced (29 to 24) in the intervention group. Similarly, a significant difference was observed in identification and referral of chest symptomatics in the intervention group at 3 and 6 months. During the 3 month follow-up a significantly higher proportion of SHG members were involved in TB awareness activities in the intervention (623/748 [83.3%]) vs control group (471/728 [64.7%]; p<0.001).

Conclusions

Findings from this study highlight the feasibility of involving SHGs through a model TB sensitization program for strengthening TB prevention and control activities.

National service for adolescents and adults with severe obsessive–compulsive and body dysmorphic disorders

Aims and Method

National guidelines for the assessment and treatment of obsessive–compulsive disorder (OCD) and body dysmorphic disorder were published in 2005 by the National Institute for Health and Clinical Excellence (NICE). Local services are unable to treat a small but significant number of the most severely ill patients successfully, and the guidelines recommend that such patients should have access to highly specialised care. From 1 April 2007, the Department of Health decided to centrally fund treatment services for severe, chronic, refractory OCD and BDD. We describe a new National Service for Refractory OCD; its rationale, treatments offered, referral criteria and expected clinical outcomes.

Results

Initial results from one centre show an average 42% reduction in OCD symptoms at the end of treatment.

Clinical Implications

The operational challenges and potential generalisability of this model of healthcare delivery are discussed. We present a summary of the progress made so far in establishing a new, coherent National Service for Refractory OCD, 18 months after the NICE guideline was published. the aim of the paper is to educate clinicians about the service and describe its rationale, treatments offered, referral criteria and expected clinical outcomes.

Community model in treating obsessive–compulsive and body dysmorphic disorders

Aims and Method

In November 2005, the National Institute for Health and Clinical Excellence published guidelines for the treatment of obsessive–compulsive disorder (OCD) and body dysmorphic disorder. These guidelines incorporated a stepped care approach with different interventions advised throughout the patient pathway. South West London and St George's Mental Health NHS Trust devised a system of expert clinicians with special expertise in OCD/body dysmorphic disorder to help deliver this model of care. To aid the delivery of service it was decided to operationalise the definitions of severity of OCD/body dysmorphic disorder at each of the stepped-care levels. Examples are given as to how this has been applied in practice. Outcome is presented in terms of clinical hours in the first year of operation.

Results

In total, 108 patients were referred to the service in the first year. Many of these patients were treated by offering advice and support and joint working with the community mental health team and psychotherapy in primary care teams who had referred. Sixty-eight patients were treated by a member of the specialist service alone and 57 of these suffered from severe OCD. Outcome data from these 57 patients is presented using an intention-to-treat paradigm. They showed a clinically and statistically significant reduction in OCD symptoms after 24 weeks of cognitive–behavioural therapy comprising graded exposure and self-imposed response prevention. the mean Yale–Brown Obsessive Compulsive Scale score dropped from 28 (severe OCD) to 19 (considerable OCD). Depressive symptoms on the Beck Depression Inventory also decreased by an average 24% over the same period.

Clinical Implications

The feasibility of extending this model of service organisation to other areas and other diagnoses is discussed.

A novel approach for prosthodontic management of patient with cleft of palate

Nutrition is important in every stage of child development. A child born with cleft lip and palate may experience difficulties while feeding due to the lack of seal of the oral cavity due to incomplete facial and palatal structures. Difficulty in feeding leads to inadequate nutrition and affects the health. Children with cleft lip and palate need certain modifications to thrive and grow. Feeding difficulties should be assessed and intervened as early as possible, as they are an important aspect of multidisciplinary team approach in management and may have an impact on long-term outcome. This case report presents fabrication of feeding appliance in 6-month-old infant with cleft palate with ethylene vinyl acetate.

Hollow Bulb One Piece Maxillary Definitive Obturator - A Simplified Approach

In maxillary defects, role of a prosthodontist is to rehabilitate the intra- and extra-oral structures and to endow with the normal function of mastication, speech, deglutition, and esthetics. Malignancies are common in the oral region and are treated usually through surgical intervention. Surgical intervention creates anatomical defects creating communication between oral and nasal cavity. Patients pose difficulties while performing normal functions such as swallowing and speaking, due to this communication. To overcome the problems encountered by the patient, obturators are fabricated. The main problem with rehabilitation of large defect is the weight of prosthesis; the prosthesis becomes very bulky and nonretentive due to its weight. Hollow obturators are fabricated to conquer this tribulation by different techniques. This case report describes a simplified method of fabrication of a definitive hollow bulb obturator for rehabilitation of a maxillary defect (Aramany's class I) by insertion of balloon.

Technical note on the isolation and characterization of collagen from fish waste material

The aim of this manuscript was to evaluate the major technical problems on the isolation and characterization of the collagen from fish waste materials that were usually faced by the growing researchers. Although the original research article published by authors contributed new information to the literature, some of them were failed to provide sufficient details in order to reproduce the study as well as could not adequately interpret/compared the results with other publications. Therefore, it is required to research the technical problems during the isolation and characterization of the collagen. This technical note provides the information which is crucial for the reader's and growing researchers for understanding as an essential part of the published research studies about the collagen extraction and characterization. Hence, this technical note may be helpful to those working on the collagen extraction and characterization from fish/marine waste materials.

Infection control knowledge and practice: A cross-sectional survey on dental laboratories in dental institutes of North India

Aim and Objectives

The aim of the study was to assess the knowledge of dental laboratory technicians regarding infection control and modes of infection control employed by them.

Settings and Design

A self-assessment questionnaire-based survey was carried out among dental technicians to assess the knowledge and practice of infection control in dental laboratories.

Materials and Methods

Survey instrument containing 16 questions were randomly distributed to 70 dental colleges of North India regarding knowledge of infection control methods and infection control practised in laboratories. Data were collected and analyzed.

Results

The response showed that 30.76% of dental technicians receive 30-50 or more than 50 impressions in a week. About 96.15% of the technicians used a plastic bag to carry impressions. Twenty-five percent of the dental technicians were aware of infection control protocol. Fifty-five percent of the technicians received impressions while wearing gloves and 61.53% of the institutes had a separate receiving area. Nearly 71.15% of the technicians communicate with the doctor regarding the disinfection of impression received in the laboratory. Almost 30.76% of the dental technicians disinfect all the impressions and 67.30% technicians use immersion for disinfection of impressions. Only 38.46% responded that they immerse impressions for 10 min for disinfection. About 73.07% use gloves, 90.38% use mouth masks, 57.69% wear eye shields, and 88.46% wear aprons while working. Nearly 78.84% of the technicians received vaccination against hepatitis B virus. Almost 69.23% of the technicians change pumice slurry after regular intervals, and 75% do not add any disinfectant. Nearly 59.61% of technicians disinfect the prostheses before sending it to the clinic, and 42.30% disinfect them by immersion technique. About disposal of waste, 80.76% said that they dispose the waste properly.

Conclusion

To summarize, most of the technicians were not aware of basic infection control protocols.

Comparative evaluation of bonding strength of computer aided machined ceramic, pressable ceramic, and milled metal implant abutment copings and effect of surface conditioning on bonding strength: An in vitro study

Background/Purpose:

The aim of this study was to compare the shear bond strength of computer aided design/computer aided machined ceramic (CAD/CAM), pressable ceramic, and milled metal implant copings on abutment and the effect of surface conditioning on bonding strength.

Materials and Methods:

A total of 90 test samples were fabricated on three titanium abutments. Among 90 test samples, 30 copings were fabricated by CAD/CAM, 30 by pressable, and 30 by milling of titanium metal. These 30 test samples in each group were further subdivided equally for surface treatment. Fifteen out of 30 test samples in each group were surface conditioned with airborne particle abrasion. All the 90 test samples were luted on abutment with glass ionomer cement. Bonding strength was evaluated for all the samples using universal testing machine at a crosshead speed of 5 mm/min. The results obtained were compared and evaluated using one-way ANOVA with post-hoc and unpaired t-test at a significance level of 0.05.

Results:

The mean difference for CAD/CAM surface conditioned subgroup was 1.28 ± 0.12, for nonconditioned subgroup was 1.20 ± 0.11. The mean difference for pressable surface conditioned subgroup was 1.18 ± 0.04, and for nonconditioned subgroup was 0.75 ± 0.28. The mean difference for milled metal surface conditioned subgroup was 2.57 ± 0.58, and for nonconditioned subgroup was 1.49 ± 0.15.

Conclusions:

On comparison of bonding strength, milled metal copings had an edge over the other two materials, and surface conditioning increased the bond strength.

Implant success lies in complications management: A report of two cases

At present, implant supported or retained prostheses are considered as a first therapeutic alternative for patients. Although the success rate of dental implants is very high, no treatment is without complications; same applies to implants also. Implant failure can be due to biological factors, i.e., loss of osseointegration or due to technical complications. This case report presents implant complications involving both factors along with the management of these cases. In implant supported overdenture patient, loss of implant on the right side and implant body fracture of the left side implant is reported and in another patient abutment screw fracture and its management is reported.