32 research outputs found
Synthesis, Characterization and Properties of In-Situ Generated Polyimide/Silica/Polyoxometalate Hybrids via Sol-Gel Method
In this research attempt, polyimide (PI) was prepared using 4-bromobenzene-1,3-diamine dihydrochloride and trimellitic anhydride chloride. The organic-inorganic nanocomposites were developed by means of TEOS and various content of polyoxometalate (POM). The silica network was synthesized in the polyimide matrix through in-situ sol-gel technique. FTIR was used to study the formation of polyimide and sol-gel nanocomposites. The physical properties of the in-situ prepared polyimide/silica/polyoxometalate nanocomposites were compared with those of neat polymer and polyimide/silica composite. Morphology study confirmed the homogeneous dispersion of silica phase in PI bulk phase with the formation of porous network structure. The glass transition temperature of the nanocomposites was in the range of 240-275 °C, i.e. higher than the neat matrix (156 °C). The melting peaks were also increased compared with the neat polyimide. Water uptake studies exhibited significant improvement in property for hybrids with higher POM content. In summary, PI/TEOS/POM 50 nanocomposite depicted improved thermal and water absorption properties along with the well-dispersed morphology
The Influencing Factors of the Career Pathway for Health Professions’ Education
Objectives: In this study our objective was to identify and explore the factors that influenced the choice of those Medical and Dental Graduates who chose HPE as a sole career, as to our knowledge there is yet to be an attempt exploring the factors influencing the choice of HPE as a sole career.
Significance of Study: Doctors and dentists have a wide variety of specialties. One such specialty is HPE that revolves around all three divisions, undergraduate, postgraduate and the continuing professional development, of a Medical and Dental Practitioner. In Pakistan, there is a varied perception of this specialty despite it encompassing the very essence in the journey of a medical and dental graduate, aiming to produce a population of ethical, knowledgeable, skilled and up-to-date professionals. (9-11)To address these, a formal process of training is required with enrollment in an HPE Program. This study has been designed to identify and explore the choice of those Graduates who have opted HPE as a sole career.
1. Materials and methods
Study Design: A qualitative exploratory design was employed to explore the factors influencing specialty preference by phenomenology(12)
Study Setting and Duration: The study was conducted at Islamic International Medical College, Riphah International University, Islamabad. Data was collected over four months, February to May, and the total duration of the study was from February to June.
Study Population: All medical and dental graduates who had completed a post-graduate HPE qualification and had at least five years’ experience.
Population size: A total 18 doctors were identified after the inclusion and exclusion criteria. However, only 6 agreed to participate in the study.
Inclusion Criteria: Medical and Dental graduates that had opted post-graduate HPE qualification
Mechanical Characterisation and Computational Modelling of Spinal Ligaments
Low back pain is a common complaint in people of all ages. The long-term success rates of many surgical devices to treat the spine have been relatively low and improved methods of pre-clinical testing of these devices are therefore needed. Sheep spine models are commonly employed in pre-clinical research studies for the evaluation of spinal devices. The anterior and posterior longitudinal ligaments (ALL and PLL) provide passive stability to the spine, however, limited studies have been conducted to characterise the mechanical properties of the ovine longitudinal ligaments or compare them to the human. Moreover, previous studies have derived material properties for the human ALL and PLL directly from force-displacement data, assuming uniform cross sectional area and length, and these values have been used extensively in finite element models of the spine for the analysis of clinical interventions.
The aim of this study was to develop a methodology to test and compare the stiffness of human and ovine spinal longitudinal ligaments and to uniquely combine experimental and specimen-specific finite element (FE) modelling approaches to determine the ligament mechanical properties.
The methodology was developed on ovine thoracic spines and then applied to human thoracic spines. The spines were dissected into functional spinal units (FSUs) with the posterior elements removed and imaged under micro computed tomography (µCT). The specimens were sectioned through the disc to leave only either the ALL or PLL intact and tested in tension to determine the stiffness. The µCT images from each FSU were used to build specimen-specific FE models of the ligaments and bony attachments. Hyper-elastic material models were used to represent the ligament behaviour. Initial values for the material model were derived using mean cross sectional area (CSA) and length (L), with the assumption that ligament was uniaxially loaded. The parameters were then iteratively changed until a best fit to the corresponding experimental load-displacement data was found for each specimen.
The stiffness of the ligaments for the ovine specimens were found to be higher than for the human specimens. This may have implications for the use of ovine FSUs for preclinical testing of devices. There was poor agreement between the material parameters derived from FE models and the initial values derived by assuming a mean CSA and L. This work demonstrates that a specimen-specific image-based approach needs to be applied to derive the elastic properties of the ligaments due to their non-uniform shape and cross-sectional area
Dynamic management of traffic signals through social IoT
Traffic congestion is a major threat to transportation sector in every urban city around the world. This causes many adverse effects like, heavy fuel consumption, increased waiting time, pollution, etc. and pose an eminent challenge to the movement of emergency vehicles. To achieve better driving we proceed towards a trending research field called Social Internet of Vehicles (SIoV). A social network paradigm that permits the establishment of social relationships among every vehicle in the network or with any road infrastructure can be radically helpful. This holds as the aim of SIoV, to be beneficial for the drivers, in improving the road safety, avoiding mishaps, and have a friendly-driving environment. In this paper, we propose a Dynamic congestion control with Throughput Maximization scheme based on Social Aspect (D-TMSA) utilizing the social, behavioral and preference-based relationships. Our proposed
Small molecule inhibitors of Late SV40 Factor (LSF) abrogate hepatocellular carcinoma (HCC): evaluation using an endogenous HCC model
Hepatocellular carcinoma (HCC) is a lethal malignancy with high mortality and poor prognosis. Oncogenic transcription factor Late SV40 Factor (LSF) plays an important role in promoting HCC. A small molecule inhibitor of LSF, Factor Quinolinone Inhibitor 1 (FQI1), significantly inhibited human HCC xenografts in nude mice without harming normal cells. Here we evaluated the efficacy of FQI1 and another inhibitor, FQI2, in inhibiting endogenous hepatocarcinogenesis. HCC was induced in a transgenic mouse with hepatocyte-specific overexpression of c-myc (Alb/c-myc) by injecting N-nitrosodiethylamine (DEN) followed by FQI1 or FQI2 treatment after tumor development. LSF inhibitors markedly decreased tumor burden in Alb/c-myc mice with a corresponding decrease in proliferation and angiogenesis. Interestingly, in vitro treatment of human HCC cells with LSF inhibitors resulted in mitotic arrest with an accompanying increase in CyclinB1. Inhibition of CyclinB1 induction by Cycloheximide or CDK1 activity by Roscovitine significantly prevented FQI-induced mitotic arrest. A significant induction of apoptosis was also observed upon treatment with FQI. These effects of LSF inhibition, mitotic arrest and induction of apoptosis by FQI1s provide multiple avenues by which these inhibitors eliminate HCC cells. LSF inhibitors might be highly potent and effective therapeutics for HCC either alone or in combination with currently existing therapies.The present study was supported in part by grants from The James S. McDonnell Foundation, National Cancer Institute Grant R01 CA138540-01A1 (DS), National Institutes of Health Grant R01 CA134721 (PBF), the Samuel Waxman Cancer Research Foundation (SWCRF) (DS and PBF), National Institutes of Health Grants R01 GM078240 and P50 GM67041 (SES), the Johnson and Johnson Clinical Innovation Award (UH), and the Boston University Ignition Award (UH). JLSW was supported by Alnylam Pharmaceuticals, Inc. DS is the Harrison Endowed Scholar in Cancer Research and Blick scholar. PBF holds the Thelma Newmeyer Corman Chair in Cancer Research. The authors acknowledge Dr. Lauren E. Brown (Dept. Chemistry, Boston University) for the synthesis of FQI1 and FQI2, and Lucy Flynn (Dept. Biology, Boston University) for initially identifying G2/M effects caused by FQI1. (James S. McDonnell Foundation; R01 CA138540-01A1 - National Cancer Institute; R01 CA134721 - National Institutes of Health; R01 GM078240 - National Institutes of Health; P50 GM67041 - National Institutes of Health; Samuel Waxman Cancer Research Foundation (SWCRF); Johnson and Johnson Clinical Innovation Award; Boston University Ignition Award; Alnylam Pharmaceuticals, Inc.)Published versio
DNA key based visual chaotic image encryption
With the exponential growth of Internet technologies, digital information exchanged over the Internet is also significantly increased. In order to ensure the security of multimedia contents over the open natured Internet, data should be encrypted. In this paper, the quantum chaotic map is utilized for random vectors generation. Initial conditions for the chaos map are computed from a DNA (Deoxyribonucleic acid) sequence along with plaintext image through Secure Hash Algorithm-512 (SHA-512). The first two random vectors break the correlation among pixels of the original plaintext image via row and column permutation, respectively. For the diffusion characteristics, the permuted image is bitwise XORed with a random matrix generated through the third random vectors. The diffused image is divided into Least Significant Bit (LSB) and Most Significant Bits (MSBs) and Discrete Wavelet Transform (DWT) is applied to the carrier image. The HL and HH blocks of the carrier image are replaced with LSBs and MSBs of the diffused image for the generation of a visually encrypted image. The detailed theoretical analysis and experimental simulation of the designed scheme show that the proposed encryption algorithm is highly secured. Efficiency and robustness of the proposed visually image encryption scheme is also verified via a number of attack analyses, i.e., sensitivity attack analysis (> 99%), differential attack analysis (NPCR > 99, UACI > 33), brute force attack (almost 7.9892), statistical attack (correlation coefficient values are almost 0 or less than zero), noise tolerance, and cropping attack. Further security analyses such as encryption quality (ID ≅ 1564, DH = 3.000), homogeneity (0.3798), contrast (10.4820) and energy (0.0144) of the scheme are also evaluated
Dynamic S-Box and PWLCM-Based Robust Watermarking Scheme
Due to the increased number of cyberattacks, numerous researchers are motivated towards the design of such schemes that can hide digital information in a signal. Watermarking is one of the promising technologies that can protect digital information. However, traditional watermarking schemes are either slow or less secure. In this paper, a dynamic S-Box based efficient watermarking scheme is presented. The original image was extracted at the receiver’s end without any loss of sensitive information. Firstly, the Secure Hash Algorithm is applied to the original image for the generation of the initial condition. Piece Wise Linear Chaotic Map is then used to generate 16 × 16 dynamic Substitution Box (S-Box). As an additional security feature, the watermark is substituted through dynamic S-Box. Hence, it is hard for the eavesdroppers to attack the proposed scheme due to the dynamic nature of S-Box. Lastly, lifting wavelet transform is applied to the host image and the High Low and High High blocks of host image are replaced with least significant bits and most significant bits of the substituted watermark, respectively. Robustness, efficiency and security of the proposed scheme is verified using Structure Similarity Index, Structure Dissimilarity Index, Structure Content, Mutual Information, energy, entropy, correlation tests and classical attacks analysis
Prevalence of Undiagnosed Depression in Patients With Type 2 Diabetes
Introduction: Type 2 Diabetes Mellitus (T2DM) is the most prevalent type of diabetes among adults and constitutes around 90% of all cases. Substantial evidence demonstrates that depression in the context of diabetes is associated with a wide range of adverse consequences such as reduced adherence to the prescribed treatment regimen, lower quality of life, higher fasting glucose and HbA1c levels, and higher health expenditures.Methods: This study was conducted to assess the depression among T2DM patients attending diabetic clinics, primary healthcare centers (PHC), Dubai Health Authority (DHA). Depressive symptoms were assessed by using both Arabic and English version of the Beck Depression Inventory.Results: Out of 1,050 diabetic patients approached, 559 were within our inclusion criteria and agreed to participate in this study (Response rate of 53%). The mainstream of the participants had T2DM for <10 years (393, 70%), were under oral hypoglycemic treatment only (479, 86%), and had good medication adherence (526, 94%). The overall depression prevalence using a cutoff of 16 was 17%. When we assessed the level of depression amongst participants in association with their sociodemographic and clinical characteristics, there was a significant difference between age groups (p < 0.00001); gender (p < 0.0001); nationality (p < 0.00001); educational level (p < 0.00001); and employment status (p < 0.0001). The type of clinic in which the T2DM patients were attending (e.g., diabetes mini-clinic vs. General Family Clinic) was also significantly associated with depression (p < 0.0001).Conclusion: Our results demonstrate that the intensive service being given in a diabetes mini-clinic compared to routine PHC clinics appears to benefit the psychological aspects of T2DM patients in the UAE population resulting in a lower incidence of depression than commonly seen in a diabetic population. We have identified a need for the establishment of these mini-clinics in each PHC clinics; and the development of campaigns and educational programs, both for health care providers and the public to decrease depression in T2DM patients in this region