Potential use of natural silk for bio-dental applications

AbstractObjectivesSilks are protein polymers that are spun into fibres by silkworms and spiders under ambient conditions. Silk has been used as a biomaterial in a variety of biological applications for many years, whereas there are few applications in dentistry. The aim of this study was to explore the potential properties of natural silk for dental applications by determining the structure and features that make natural silk a biocompatible candidate.MethodsWe conducted a literature search through the recognized databases of medline, ISI web of science, SCOPUS, and EBASE to elucidate the natural properties of silk, its processing for biomedical applications and its use in dental applications.ResultsSilk has excellent natural properties, such as strength, resistance to light, temperature and humidity and biocompatibility. Once silk has been dissolved, it can be used to produce a variety of materials, such as films, gels, fibres, nanofibres, granules, foams, spheres and electrospun mats, on a micro or nano scale. Applications in dentistry include biomineralization, tissue engineering for scaffold applications and drug delivery.ConclusionsThere has been renewed research on silk-based materials for various biomedical applications, including dentistry

Robust Framework to Combine Diverse Classifiers Assigning Distributed Confidence to Individual Classifiers at Class Level

We have presented a classification framework that combines multiple heterogeneous classifiers in the presence of class label noise. An extension of m-Mediods based modeling is presented that generates model of various classes whilst identifying and filtering noisy training data. This noise free data is further used to learn model for other classifiers such as GMM and SVM. A weight learning method is then introduced to learn weights on each class for different classifiers to construct an ensemble. For this purpose, we applied genetic algorithm to search for an optimal weight vector on which classifier ensemble is expected to give the best accuracy. The proposed approach is evaluated on variety of real life datasets. It is also compared with existing standard ensemble techniques such as Adaboost, Bagging, and Random Subspace Methods. Experimental results show the superiority of proposed ensemble method as compared to its competitors, especially in the presence of class label noise and imbalance classes

Formulation and in vitro evaluation of mucoadhesive controlled release matrix tablets of flurbiprofen using response surface methodology

The objective of the current study was to formulate mucoadhesive controlled release matrix tablets of flurbiprofen and to optimize its drug release profile and bioadhesion using response surface methodology. Tablets were prepared via a direct compression technique and evaluated for in vitro dissolution parameters and bioadhesive strength. A central composite design for two factors at five levels each was employed for the study. Carbopol 934 and sodium carboxymethylcellulose were taken as independent variables. Fourier transform infrared (FTIR) spectroscopy studies were performed to observe the stability of the drug during direct compression and to check for a drug-polymer interaction. Various kinetic models were applied to evaluate drug release from the polymers. Contour and response surface plots were also drawn to portray the relationship between the independent and response variables. Mucoadhesive tablets of flurbiprofen exhibited non-Fickian drug release kinetics extending towards zero-order, with some formulations (F3, F8, and F9) reaching super case II transport, as the value of the release rate exponent (n) varied between 0.584 and 1.104. Polynomial mathematical models, generated for various response variables, were found to be statistically significant (PO objetivo do presente estudo foi formular comprimidos mucoadesivos de flurbiprofeno, de liberação controlada, e otimizar o perfil da liberação do fármaco e a bioadesão, utilizando a metodologia de superfície de resposta. Prepararam-se os comprimidos via técnica de compressão direta, que foram avaliados in vitro quanto aos parâmetros de dissolução e da força bioadesiva. Planejamento com componente central para dois fatores em cinco níveis cada foi empregado para esse estudo. Carbopol 934 e carboximetilcelulose sódica foram tomados como variáveis independentes. Efetuaram-se estudos de espectroscopia por transformada de Fourier (FTIR) para observar a estabilidade do fármaco durante a compressão direta e para avaliar a interação a fármaco-polímero. Aplicaram-se vários métodos cinéticos para avaliar a liberação do fármaco dos polímeros. Gráficos de superfície de contorno e de resposta foram efetuados para retratar a relação entre as variáveis dependentes e a resposta. Os comprimidos mucoadesivos de flurbiprofeno apresentaram cinética de liberação não-fickiana, estendendo para ordem zero, para algumas formulações (F3, F8 e F9), alcançando transporte super caso II, à medida que o valor do expoente (n) de taxa de liberação variou entre 0,584 e 1,104. Modelos matemáticos polinomiais, gerados por diversas variáveis de resposta, foram estatisticamente, significativos (

Characterization of doxorubicin nanoparticles prepared by ionic gelation

Purpose: To prepare and characterise doxorubicin nanopatrticles and study their drug delivery in breast cancer.Methods: Doxorubicin nanoparticles were prepared by ionic gelation method using sodium alginate as polymer. The formulations were optimized by cross-linking CaCl2 with sodium alginate at different concentrations. Zeta sizer Nano ZS (UK) was used to determine the mean particle size distribution of the nanoparticle preparations. The shape and external morphologies of the nanoparticles were evaluated by scanning electron microscopy (SEM). Drug release was determined and kinetic release analysis was applied to determine the mechanism of drug release.Results: Entrapment efficiency and mean particle size values were correlated. Scanning electron micrographs showed that the nanoparticles were spherical with little irregularity but without cracks. Doxorubicin release from the sodium alginate nanoparticles followed Korsmeyer-Peppas model which suggest that drug release from the nanoparticles was by diffusion and dissociation from the natural polymer matrix.Conclusion: The doxorubicin-loaded nanoparticles showed concentration-dependent increases in entrapment efficiency. The nanoparticles displayed anticancer properties in breast cancer cell line, thus indicating its potential fo chemotherapeutic application.Keywords: Doxorubicin, Ionic gelation, Nanoparticles, Sodium alginate, Drug release mechanism, Anticance

Intracranial Low Grade Glioma: a Clinical Study of 35 Cases in a Teaching Institute

Objective: To determine the clinical manifestation and surgical outcome of patients with low grade Glioma.Material and Methods: This descriptive (cross sectional) study was done at the Neurosurgery Department, Mardan Medical Complex Mardan. The study period was March 2017 to February 2018. Patient of any age and gender presented to outpatient department or referred from some other medical facility and diagnosed as low grade Glioma on clinical and radiological grounds and later confirmed by histopathology were included. Results: Out of 35 patients, 20 (57%) were male and 15 (42%) were female. 20 to 80 years was the age range and mean age was 46.36 ± 17.11 years. Frontal lobe was the most frequent area of location, followed by parietal 9 (25%) and temporal 8 (22%) lobe. Pre-operativeKarnofsky score was 90 in 16 (45%), 80 in 8 (22%), 70 in 6 (17%) and 60 in 5 (14%) of patients. Gross total resection was achieved in 13 (37%), radical subtotal resection in 10 (28%), subtotal resection in 10 (28%) and biopsy taken in 02 (5%) patients. histopathology revealed Astrocytoma in 15 (42%), mixed Oligoastrocytoma in 12 (34%) and Oligodendroglioma in 8 (22%) number of patients. Post operatively surgical outcome was measured by improvement in symptomatology, Karnofsky score and seizure control. Conclusion: Conscious level, Karnofsky Performance score, seizure control are important parameters for surgical outcome in patients with low grade Gliomas. Gross total resection of the tumor is a better option for good surgical outcome

The role of financial constraints in business environment : evidence from business group affiliated and non-affiliated firms in Pakistan

The main purpose of this study is to investigate the relationship between Cash Flows, Growth Opportunities, Firm Size, Firm Age, Firm Performance, Investment, Financial constraints and Leverage between the B.G AFs and NAFs of Pakistan. Current study consists of the balanced panel data containing 86 B.G AFs vs. 90 NAFs of the Pakistan. This study covers the yearly data period from 2007 to 2017. The findings showed that the cash flows are positively correlated with the return on assets, investments, financial constraints, while leverage is negatively correlated with the financial constraints. The positive correlation between cash flows and return on asset is higher for the B.G AFs, which means the B.G AFs are more profitable than the NAFs. The correlation of cash flows with the investment and financial constraints is positive but lower for the B.G AFs, showing that AFs investment is less sensitive and less financially constrained than NAFs. The inverse correlation between leverage and financial constraints shows that the B.G AFs have easy access to the financial sources. The positive and higher correlation of growth opportunities with cash flows and return on assets shows that the AFs growth is higher than NAFs

Comparison of One vs. Two Burr Hole Craniostomy in Chronic Subdural Hematoma Recurrence

Introduction/Objective:  Chronic subdural hematoma (CSDH) is most frequent neurosurgical conditions. To find the recurrence rate of chronic subdural hematoma in patients who underwent one vs. two burr craniostomy. Material And Methods:  A randomized controlled trial was conducted at the Neurosurgery department, Ayub Teaching Hospital, Abbottabad. In the current study, a total of 76 (38 in each group) patients were observed. ASA-I, ASA-II, ASA III patients, symptomatic radiologically proven Chronic subdural hematoma. Patients were randomly allocated into two groups of 38 patients each. randomization with blocks. Group A was treated with intraoperative epidural methylprednisolone while Group B was treated with normal saline only. Clinical information was recorded on a pre-designed proforma. Results:  Mean age was 54 years in group A, and 56 years in group B. In group A, 74% were male and 26% of patients were female. In Group B, 76% were male and 24% were female. The group A, 5% of patients had recurrence while in Group B, 13% of patients had a recurrence. There existed a significant difference between effectiveness and not-effectiveness of one/two burr hole craniostomy among patients who were less than 40 years. Conclusion:  The recurrence rate of chronic subdural hematoma is higher in patients undergoing two burr hole craniostomy as compared to one burr craniostomy

Frequency of Noise Induced Hearing Loss Among Traffic Wardens of Lahore

Background: Noise-induced hearing loss (NIHL) is a major cause of disability throughout the world. It is the most common irreversible job-related hazard in the world with a higher burden in the developing regions of the world. Certain occupations are at high risk for NIHL. Traffic wardens could be considered highly vulnerable group as they are exposed to long hours of traffic noise. The objective of this study was to determine the frequency of noise induced hearing loss among traffic wardens of Lahore city.Material and Methods: It was a cross-sectional, descriptive study, carried out from 1st December 2018 to 31st May 2019, in which 329 traffic wardens appointed in 34 beats/sectors of Lahore city were included. Data was collected through a structured questionnaire, followed by Pure Tone Audiometry (PTA) of all the subjects.Results: A total of 329 traffic wardens were selected for this study. Mean age of the traffic wardens was 35.35 ± 1.21 years. NIHL was present in 174 (52.9%) traffic wardens, out of which, 138 (79.3%) had mild, 32 (18.4%) moderate, and 4 (2.3%) had moderately severe degree of hearing loss. Among the 329 traffic wardens, 165 (50.2%) had exposure to noise between 7am to 3pm (morning shift) and 42 (12.8%) had some problem with their hearing. Only 12 (3.6%) had ringing in the ears or tinnitus, 140 (42.6%) wore any hearing protection during duty hours and 42 (12.8%) said they had difficulty in hearing and frequently asked people to repeat themselves.Conclusion: In this study a high frequency of noise induced hearing loss was reported among traffic wardens of Lahore city with most of them having mild to moderate degree of hearing loss

A comparative bioavailability study of aceclofenac products in healthy human subjects

This study was conducted to compare the bioavailability of two branded formulations of aceclofenac and to evaluate their pharmacokinetic behavior. For bioequivalence study of two formulations of aceclofenac; drug A and drug B were administered to 18 healthy human volunteers using a two-treatment, two-way cross over study design in a randomized fashion. For the determination of aceclofenac plasma concentration, validated HPLC method with UV-visible detector, 20 µl injecting loop and C18 analytical column were used. The lower limit of detection is 0.0195µg/ml and quantitation range is 0.039, 0.078, 0.156, 0.312, 0.625, 1.25, 2.5, 5, 10 and 20µg/ml. Different pharmacokinetic parameter were determined including Tmax, T1/2, Cmax, AUC0-t, AUC0-?, vd, ke for two formulations of aceclofenac in plasma. After log-transformation of plasma data for bioequivalence Cmax, AUC0-t and AUCt-? were tested. The Cmax values of 7.69 ± 0.14221µg/ml and 6.82 ± 0.13411µg/ml were attained in 3.14 ± 0.0801 h and 2.94 ± 0.1878 h for drug A and Drug B, respectively. AUC0-t was 45332.79 ± 2096.770µg.h/ml and 43842.56 ± 1046.954µg.h/ml, respectively. AUC0-? was 45329.97±2138.871µg.h/ml and 43589.97 ± 1039.78 µg.h/ml for drug A and Drug B, respectively. The t1/2 values were found to be 3.14 ± 0.080 h and 3.01 ± 0.024 h for drug A and Drug B