Gastrointestinal Stromal Tumors: A Review of Case Reports, Diagnosis, Treatment, and Future Directions

Gastrointestinal stromal tumor (GIST) is a nonepithelial, mesenchymal tumor first described by Mazur and Clark in 1983. Since then, its molecular biology has been studied in great detail. Special interest in the role of tyrosine kinase in its regulation has been the target by different drug research. Mutation in c-kit exons 9, 11, 13, 17 and PDGFRA mutation in exons 12, 14, 18 are responsible for activation of gene signaling system resulting in uncontrolled phosphorylation and tissue growth. However, 5 to 15% of GISTs does not harbor these mutations, which raises additional questions in another alternate signaling pathway mutation yet to be discovered. Diagnosis of GISTs relies heavily on KIT/CD117 immunohistochemical staining, which can detect most GISTs except for a few 3% to 5% that harbors PDGFRA mutation. Newer staining against PKC theta and DOG-1 genes showed promising results but are not readily available. Clinical manifestation of GISTs is broad and highly dependent on tumor size. Surgery still remains the first-line treatment for GISTs. The advancement of molecular biology has revolutionized the availability of newer drugs, Imatinib and Sunitinib. Together with its advancement is the occurrence of Imatinib/Sunitinib drug resistance. With this, newer monoclonal antibody drugs are being developed and are undergoing clinical trials to hopefully improve survival in patients with GISTs

Design of heat sinks for wearable thermoelectric generators to power personal heating garments: A numerical study

To mitigate climate change attributed to the built environments, there have been tremendous efforts to improve air conditioning systems in the buildings. The possibility of harvesting body heat as a renewable energy source to power a wearable personal heating system is investigated. The aim of this study is to integrate a wearable personal heating system with a thermoelectric generator (TEG) that harvests the body heat which is used to convert it into electricity. Moreover, the interaction between the TEG configuration and power output is studied. The power generation of TEG system is obtained by COMSOL Multiphysics software. The simulation results concluded that all the four proposed heat sink configurations can improve the power output of the wearable TEG at 1.4 m/s and 3m/s compared to that of the reference model. Furthermore, the perforated and trapezium shapes of heat sinks have a significantly better performance in comparison to conventional heat sinks

Building-Related Symptoms, Energy, and Thermal Control in the Workplace: Personal and Open Plan Offices

This study compared building-related symptoms in personal and open plan offices, where high and low levels of control over the thermal environment were provided, respectively. The individualized approach in Norway provided every user with a personal office, where they had control over an openable window, door, blinds, and thermostat. In contrast, the open plan case studies in the United Kingdom provided control over openable windows and blinds only for limited occupants seated around the perimeter of the building, with users seated away from the windows having no means of environmental control. Air conditioning was deployed in the Norwegian case study buildings, while displacement ventilation and natural ventilation were utilized in the British examples. Field studies of thermal comfort were applied with questionnaires, environmental measurements, and interviews. Users’ health was better in the Norwegian model (28%), while the British model was much more energy efficient (up to 10 times). The follow-up interviews confirmed the effect of lack of thermal control on users’ health. A balanced appraisal was made of energy performance and users’ health between the two buildings

Effect of vitamin C on N,N′-dimethyl-4,4′-bipyridinium dichloride-induced hepatic and renal toxicity in Swiss albino mice

Purpose: To evaluate the effectiveness of vitamin C on paraquat-induced hepatic and renal toxicity in Swiss albino mice.Methods: Three groups of Swiss albino mice (n = 10), i.e., control, paraquat (15 mg/kg) and paraquat (15 mg/kg) + vitamin C (20 mg/kg) were used in the study. The drugs were administered intraperitoneally for four days. Blood samples were collected on day 5 for determination of serum levels of liver and renal biomarkers. Thereafter, the animals were sacrificed; liver and kidney were excised and preserved in neutral formalin for histopathological analysis.Results: The paraquat-treated animals showed higher levels of aspartate transaminase (AST), alanine transaminase (ALT), serum urea and creatinine, relative to values for control. Histopathological examination of the paraquat-treated animals showed cytoplasmic vacuolar degeneration and congestion of central vein in the liver, and glomerular necrosis in the kidneys. Control and vitamin C-treated mice showed normal architecture of liver and kidney.Conclusion: These results indicate that vitamin C modulated the paraquat-induced liver and renal abnormalities in the experimental animals. Thus vitamin C exerts hepatoprotective and renoprotective effects against paraquat poisoning.Keywords: Paraquat poisoning, Liver, Kidney, Vitamin C, Toxicity, Histopatholog

KINETIC AND THERMODYNAMIC STUDIES FOR THE H 2 S ADSOPRTION USING TiO 2 NANOMATERIALS

This study is continuation of the studies carried out by our research group focusing on the catalytic and photocatalytic destruction of H 2 S gas using pure and doped TiO 2 nanomaterials. To further study the H 2 S adsoprtion mechanism, kinectic and thermodynamic studies were carried out, folowed by adsorption isotherms like Langmuir and Freundlich isotherms. The reactions were assumed to be pseudo first order reactions. In agreement with our previous findings, lower activation energies were attained for 2% sulphur doped nanoparticles and nanofibers, the energy that of nanofibers being quite lower than the nanoparticles indicating the better destruction efficiency in case of nanofibers

Monte Carlo Simulation of Sinusoidally Modulated Superlattice Growth

The fabrication of ZnSe/ZnTe superlattices grown by the process of rotating the substrate in the presence of an inhomogeneous flux distribution instead of successively closing and opening of source shutters is studied via Monte Carlo simulations. It is found that the concentration of each compound is sinusoidally modulated along the growth direction, caused by the uneven arrival of Se and Te atoms at a given point of the sample, and by the variation of the Te/Se ratio at that point due to the rotation of the substrate. In this way we obtain a ZnSe$_{1-x}$Te$_x$ alloy in which the composition $x$ varies sinusoidally along the growth direction. The period of the modulation is directly controlled by the rate of the substrate rotation. The amplitude of the compositional modulation is monotonous for small angular velocities of the substrate rotation, but is itself modulated for large angular velocities. The average amplitude of the modulation pattern decreases as the angular velocity of substrate rotation increases and the measurement position approaches the center of rotation. The simulation results are in good agreement with previously published experimental measurements on superlattices fabricated in this manner

Design of electron beam bending magnet system for electron and photon therapy: A simulation approach

The doubly achromatic electron beam bending magnet system using two sector magnets has been designed for the medical applications to treat the cancer. The aim of electron beam bending magnet system is to focus an electron beam having a spot size less than 3 mm × 3 mm, energy spread within 3% and divergence angle ≤ 3mrad at the target position. To achieve these parameters, the simulation has been carried out using Lorentz-3EM software. The beam spot, divergence angle and energy spread have been observed with respect to the variation in angles of sector magnets and drift distance. Based on the simulated results, it has been optimized that the first and second magnet has an angle 206° and 35° and the drift distance 80 mm. It is also observed that at the 1125, 1762, 2570, 3265 and 4155 Amp-turn, the optimized design produces 3369, 4972, 6384, 7584 and 9568 Gauss of magnetic field at median plane which require to bend 6, 9, 12, 15 and 18 MeV energy of electron, respectively, for the electron therapy application. The output beam parameters of the optimized design are energy spread ±3%, divergence angle ~3 mrad and spot size 2.6 mm. Moreover, for 6 MV and 15 MV photon therapy applications, an electron beam of energy 6.5 MeV and 15.5 MeV extracted from magnet system and focused on the bremsstrahlung target. Various materials have been studied for photon generation using Monte Carlo based Fluka code and Tungsten material has been optimized as bremsstrahlung target which produces continuous energy bremsstrahlung spectrum. For the photon therapy, the 1233 and 3327 amp-turn, in an optimized design produces 3616 and 7785 Gauss of magnetic field at median plane require to bend 6.5 and 15.5 MeV energy of electron, respectively, which further produces bremsstrahlung radiation from Tungsten target

Neurological complications in patients with plasmodium vivax malaria from Karachi, Pakistan

Background: Malaria remains an endemic disease in Pakistan with an estimated healthcare burden of 1.6 million cases annually, with Plasmodium vivax accounting for 67% of reported cases. P. vivax is the most common species causing malaria outside of Africa, with approximately 13.8 million reported cases worldwide. Method: We report a series of P. vivax cases with cerebral involvement that presented at Aga Khan University Hospital, Karachi, Pakistan. Results: The majority of the patients presented with high-grade fever accompanied by projectile vomiting and abnormal behaviour, seizures, shock and unconsciousness. Seven of 801 patients with P. vivax monoinfection presented or developed cerebral complications. P. vivax infections were diagnosed based on peripheral smears and rapid diagnostic testing. Conclusion: P. vivax infection can lead to severe complications, although not with the frequency of Plasmodium falciparum infection. Current cases highlight an increasing trend of cerebral complications caused by P. vivax

Secure and Internet-Less Connectivity to a Blockchain Network for Limited Connectivity Bank Users

Over the past few years, we have seen the emergence of a wide range of banking architectures, technologies, and applications made possible by the significant improvements in hardware, software, and networking technologies. Nowadays, innovative solutions are being developed by banks to leverage the benefits of blockchain, to improve their business agility and performance, and to make their business operations more efficient and secure. However, there are still cases where regular access to Internet is impossible or unreliable due to saturated networks or harsh environments, hence limiting the deployment of typical blockchain based solutions. In this context, an approach using a new connectivity technology is needed in order to increase mobile Internet services for any device to reach nearly 95% of the world population, instantly, simply by drawing on existing mobile phone networks, with no additional infrastructure development. We aim to give the user full bank access from their device, even if the device is not a smart one, using ordinary mobile phone networks. However, providing efficient and secure communications over lossy and low bandwidth networks remains a challenge. The main objective of this paper will be to design an end-to-end and low overhead secure solution for the communications between mobile devices and their corresponding remote application servers that using blockchain via ordinary mobile networks