46 research outputs found

    Dentoalveolar heights in skeletal class I normodivergent facial patterns

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    OBJECTIVE: To determine the dentoalveolar heights (mm) in skeletal class I normodivergent facial pattern and compare the same heights in male and female subjects. STUDY DESIGN: Cross-sectional observational study. PLACE AND DURATION OF STUDY: Orthodontics Clinic, The Aga Khan University Hospital, Karachi, from July to October 2009. METHODOLOGY: Eighty one subjects were selected from the orthodontic record at the Aga Khan University Hospital Karachi. The inclusion criteria were an age range of 12 to 30 years and skeletal class I normodivergent facial pattern with exclusion criteria of prior orthodontic treatment, restored teeth and craniofacial anomalies/syndromes. The pre-treatment cephalographs of the patients were traced manually on acetate paper by the principal investigator. The various land marks were marked and the parameters were recorded. Mean and standard deviations were determined. Independent sample t-test was used to find gender dimorphism. RESULTS: The mean age of the sample was 15.8 3.4 years. Mean ANB angle for the entire sample was 2.6degrees 1.2degrees and for angle SN-MP was 31.5degrees 2.5degrees. Descriptive analysis presented mean value of upper anterior, upper posterior, lower anterior and lower posterior dentoalveolar heights to be 28.5 2.7 mm, 22.9 2.6 mm, 41.3 2.9 mm and 31.5 3.2 mm respectively. Male subjects had significantly greater mean values for lower anterior and posterior dentoalveolar heights (p=0.02 and 0.05 respectively). CONCLUSION: The mean dentoalveolar heights for the skeletal class I normodivergent sample were established. No gender dimorphism was found for upper dentoalveolar heights however, lower anterior and lower posterior were significantly greater in males as compared to females. All the values of dentoalveolar heights for male subjects were greater than female subjects

    Plaque index in multi-bracket fixed appliances

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    Objective: To compare the plaque index in patients receiving multi-bracket fixed orthodontic treatment for various factors like age, gender, socio-economic status, brushing practices, meal habits, types of brackets, types of ligations, use of mouthwash and duration of treatment. Study Design: Cross-sectional analytical study. Place and Duration of Study: Orthodontics Clinic, The Aga Khan University Hospital, from September to November 2011. Methodology: Socio-demographic and clinical modalities were defined and recorded for 131 patients having multi-bracket fixed appliances. The plaque index of subjects were recorded according to the Silness and Loe plaque index method. Independent sample t-test was used to see difference in plaque index in factors having two variables. One way ANOVA and Post-Hoc Tukey tests were used to see difference in plaque index in factors having three variables. Kappa statistics was used to assess inter examiner reliability. P-value of ≤ 0.05 was taken to be significant. Results: The sample comprised of 37% males (n = 48) and 63% females (n = 83). The plaque index had statistically significant association with practice of brushing i.e., timing of brushing (p=0.001), method of brushing (p=0.08), type of ligatures (p=0.05) and frequency of visits (p=0.01). Conclusion: The plaque accumulation is significantly decreased in subjects who brush the teeth twice or more than twice a day and those who brush their teeth after breakfast. The use of interdental brush and stainless steel ligatures had significantly low plaque. Subjects presenting with more frequent appointments of short-period had significantly less plaque

    Resilience and agility in sustainable supply chains: A relational and dynamic capabilities view

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    The outbreak of COVID-19 has exposed vulnerabilities of supply chains (SCs) and has further accentuated the importance of creating resilient, agile and sustainable SCs. The present study assesses the role of SC technology capabilities in supporting organisations to enhance their SC resilience, thereby improving them on the sustainability front. Drawing from the relational and dynamic capabilities view, the study develops a conceptual model to test the hypothesised relationships. We test the hypotheses employing a survey-based approach that utilises a cross-sectional design. The study uses factor analysis and structural equation modelling techniques to test the fit of the measures to the structural models. We collected the data from the manufacturing / logistics firms in the UK and the US. The findings indicate that SC technology capabilities, agility and visibility positively enhance SC resilience, which in turn affects SC sustainability positively. We understand how SC resilience can determine the effectiveness of the efforts towards enhancing technology capability. Firms must collaborate and build technology capabilities to achieve resilient and sustainable SCs. This research would assist the practitioners and researchers in understanding the role of technology capability and SC resilience and guide them with respect to the configuration of sustainable SCs

    Determination of Most Frequent Emergencies in Patients with Fixed and Removable Orthodontic Appliances at Tertiary Care Dental Hospital

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    OBJECTIVES: To determine the frequency of emergencies in patients with fixed and removable orthodontic appliances at tertiary care dental hospital. METHODOLOGY: A questionnaire was designed for this descriptive cross-sectional study to be filled by the clinician (L3/L4 FCPS resident) at the end of addressing every orthodontic emergency. Sampling was done under consecutive non-probability protocols. Descriptive statistics were applied to determine the frequency of different orthodontic emergencies, and Pearson’s chi-square test was applied to determine association of emergencies with gender and etiology of emergency (patient related vs operator related). Data was analyzed on SPSS version 20. RESULTS: A total of 175 patients reported with orthodontic emergencies. The sample comprised 38.3% males and 61.7% females. Most frequent orthodontic emergency reported was deboned brackets in fixed appliances, while the most common emergency in removable appliances was traumatic PNAM. A statistically significant association (Pearson’s Chi Square=4.74, Cramer’s V=0.165, p=0.029) was seen for removable and fixed appliance emergencies with males and females. CONCLUSION: Most frequent fixed appliance orthodontic emergencies were deboned brackets while for removable appliance emergencies were trauma due to PNAM. Emergencies with removable appliances were mostly due to the operator related factors, while in fixed appliances patient related factors were dominating

    Correlation of Dental and Skeletal Maturity Using Dimirgian and Cervical Vertebral Maturation Indices in Orthodontic Patients

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    OBJECTIVES To determine the correlation between skeletal and dental maturity using the cervical vertebral maturation (CVM) index (CVMI) and Demirjian index (DI) in orthodontic patients. METHODOLOGY Panoramic and lateral cephalogram radiographs of 105 patients pretreatment records were retrieved. Tooth calcification stages for mandibular left molar were recorded using Demirjian Index on the panoramic radiograph. The skeletal maturation stages were evaluated on a lateral cephalogram through CVMI staging. Fisher’s exact test and Cramer’s V values were estimated to determine the correlation between DI and CVMI. Weighted kappa statistics were used to determine the reproducibility of inter-observer assessment of DI and CVMI. A p-value of ≤ 0.05 was taken to be statistically significant. RESULTS A statistically significant correlation is present among the various stages of DI and CVMI for the males (Fisher exact = 25.006, Cramer’s V = 0.848, p = < 0.001) and females (Fisher exact = 41.006, Cramer’s V = 0.623, p = <0.001). A comparison of DI with respect to CVMI shows a more advanced skeletal stage in males than for female subjects. CONCLUSION The correlation between CVMI and DI stages was found to be highly significant. Stage D and F of DI were significantly correlated with stage 3 and stage 4 of CVMI in females and males respectively

    Enhanced biocidal activity of Au nanoparticles synthesized in one pot using 2, 4-dihydroxybenzene carbodithioic acid as a reducing and stabilizing agent

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    Background The conjugation of gold nanoparticles with biocides such as natural products, oligosaccharides, DNA, proteins has attracted great attention of scientists recently. Gold NPs covered with biologically important molecules showed significant enhancement in biological activity in comparison with the activity of the free biocides. However, these reports are not very systematic and do not allow to draw definitive conclusions. We therefore embarked in a systematic study related to the synthesis and characterization of biocidal activities of Au nanoparticles conjugated to a wide variety of synthetic and natural biomolecules. In this specific report, we investigated the activity of a synthetic biocide, 2-4, Dihydroxybenzene carbodithioic acid (DHT). Results Au nanoparticles (NP) with a mean size of about 20 nm were synthesized and functionalized in one pot with the help of biocide 2,4-Dihydroxybenzene carbodithioic acid (DHT) to reduce HAuCl4 in aqueous solution. Conjugation of DHT with gold was confirmed by FT-IR and the amount of DHT conjugated to the Au nanoparticles was found to be 7% by weight by measuring the concentration of DHT in the supernatant after centrifugation of the Au NPs. To ascertain the potential for in vivo applications, the stability of the suspensions was investigated as a function of pH, temperature and salt concentration. Antibacterial, antifungal, insecticidal and cytotoxic activities of the Au-DHT conjugates were compared with those of pure DHT and of commercially available biocides. In all cases, the biocidal activity of the Au-DHT conjugates was comparable to that of commercial products and of DHT. Conclusions Since the DHT concentration in the Au-DHT conjugates was only about 7%, our results indicate that conjugation to the Au NPs boosts the biocidal activity of DHT by about 14 times. The suspensions were found to be stable for several days at temperatures of up to 100°C, salt concentrations up to 4 mol/L and a pH range of 2-13

    Stability of perovskite solar cells: issues and prospects

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    Even though power conversion efficiency has already reached 25.8%, poor stability is one of the major challenges hindering the commercialization of perovskite solar cells (PSCs). Several initiatives, such as structural modification and fabrication techniques by numerous ways, have been employed by researchers around the world to achieve the desired level of stability. The goal of this review is to address the recent improvements in PSCs in terms of structural modification and fabrication procedures. Perovskite films are used to provide a broad range of stability and to lose up to 20% of their initial performance. A thorough comprehension of the effect of the fabrication process on the device's stability is considered to be crucial in order to provide the foundation for future attempts. We summarize several commonly used fabrication techniques – spin coating, doctor blade, sequential deposition, hybrid chemical vapor, and alternating layer-by-layer. The evolution of device structure from regular to inverted, HTL free, and ETL including the changes in material utilization from organic to inorganic, as well as the perovskite material are presented in a systematic manner. We also aimed to gain insight into the functioning stability of PSCs, as well as practical information on how to increase their operational longevity through sensible device fabrication and materials processing, to promote PSC commercialization at the end

    Context-aware pending interest table management scheme for NDN-based VANETs

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    In terms of delivery effectiveness, Vehicular Adhoc NETworks (VANETs) applications have multiple, possibly conflicting, and disparate needs (e.g., latency, reliability, and delivery priorities). Named Data Networking (NDN) has attracted the attention of the research community for effective content retrieval and dissemination in mobile environments such as VANETs. A vehicle in a VANET application is heavily reliant on information about the content, network, and application, which can be obtained from a variety of sources. The information gathered can be used as context to make better decisions. While it is difficult to obtain the necessary context information at the IP network layer, the emergence of NDN is changing the tide. The Pending Information Table (PIT) is an important player in NDN data retrieval. PIT size is the bottleneck due to the limited opportunities provided by current memory technologies. PIT overflow results in service disruptions as new Interest messages cannot be added to PIT. Adaptive, context-aware PIT entry management solutions must be introduced to NDN-based VANETs for effective content dissemination. In this context, our main contribution is a decentralised, context-aware PIT entry management (CPITEM) protocol. The simulation results show that the proposed CPITEM protocol achieves lower Interest Satisfaction Delay and effective PIT utilization based on context when compared to existing PIT entry replacement protocols

    Association of respiratory symptoms and lung function with occupation in the multinational Burden of Obstructive Lung Disease (BOLD) study

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    Background Chronic obstructive pulmonary disease has been associated with exposures in the workplace. We aimed to assess the association of respiratory symptoms and lung function with occupation in the Burden of Obstructive Lung Disease study. Methods We analysed cross-sectional data from 28 823 adults (≥40 years) in 34 countries. We considered 11 occupations and grouped them by likelihood of exposure to organic dusts, inorganic dusts and fumes. The association of chronic cough, chronic phlegm, wheeze, dyspnoea, forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1)/FVC with occupation was assessed, per study site, using multivariable regression. These estimates were then meta-analysed. Sensitivity analyses explored differences between sexes and gross national income. Results Overall, working in settings with potentially high exposure to dusts or fumes was associated with respiratory symptoms but not lung function differences. The most common occupation was farming. Compared to people not working in any of the 11 considered occupations, those who were farmers for ≥20 years were more likely to have chronic cough (OR 1.52, 95% CI 1.19–1.94), wheeze (OR 1.37, 95% CI 1.16–1.63) and dyspnoea (OR 1.83, 95% CI 1.53–2.20), but not lower FVC (β=0.02 L, 95% CI −0.02–0.06 L) or lower FEV1/FVC (β=0.04%, 95% CI −0.49–0.58%). Some findings differed by sex and gross national income. Conclusion At a population level, the occupational exposures considered in this study do not appear to be major determinants of differences in lung function, although they are associated with more respiratory symptoms. Because not all work settings were included in this study, respiratory surveillance should still be encouraged among high-risk dusty and fume job workers, especially in low- and middle-income countries.publishedVersio

    PANC Study (Pancreatitis: A National Cohort Study): national cohort study examining the first 30 days from presentation of acute pancreatitis in the UK

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    Abstract Background Acute pancreatitis is a common, yet complex, emergency surgical presentation. Multiple guidelines exist and management can vary significantly. The aim of this first UK, multicentre, prospective cohort study was to assess the variation in management of acute pancreatitis to guide resource planning and optimize treatment. Methods All patients aged greater than or equal to 18 years presenting with acute pancreatitis, as per the Atlanta criteria, from March to April 2021 were eligible for inclusion and followed up for 30 days. Anonymized data were uploaded to a secure electronic database in line with local governance approvals. Results A total of 113 hospitals contributed data on 2580 patients, with an equal sex distribution and a mean age of 57 years. The aetiology was gallstones in 50.6 per cent, with idiopathic the next most common (22.4 per cent). In addition to the 7.6 per cent with a diagnosis of chronic pancreatitis, 20.1 per cent of patients had a previous episode of acute pancreatitis. One in 20 patients were classed as having severe pancreatitis, as per the Atlanta criteria. The overall mortality rate was 2.3 per cent at 30 days, but rose to one in three in the severe group. Predictors of death included male sex, increased age, and frailty; previous acute pancreatitis and gallstones as aetiologies were protective. Smoking status and body mass index did not affect death. Conclusion Most patients presenting with acute pancreatitis have a mild, self-limiting disease. Rates of patients with idiopathic pancreatitis are high. Recurrent attacks of pancreatitis are common, but are likely to have reduced risk of death on subsequent admissions. </jats:sec
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