Numerical study of radiative Maxwell viscoelastic magnetized flow from a stretching permeable sheet with the Cattaneo–Christov heat flux model

In this article, the Cattaneo-Christov heat flux model is implemented to study non-Fourier heat and mass transfer in the magnetohydrodynamic (MHD) flow of an upper convected Maxwell (UCM) fluid over a permeable stretching sheet under a transverse constant magnetic field. Thermal radiation and chemical reaction effects are also considered. The nonlinear partial differential conservation equations for mass, momentum, energy and species conservation are transformed with appropriate similarity variables into a system of coupled, highly nonlinear ordinary differential equations with appropriate boundary conditions. Numerical solutions have been presented for the influence of elasticity parameter (), magnetic parameter (M2), suction/injection parameter (λ), Prandtl number (Pr), conduction-radiation parameter (Rd), sheet stretching parameter (A), Schmidt number (Sc), chemical reaction parameter (γ_c), modified Deborah number with respect to relaxation time of heat flux (i.e. non-Fourier Deborah number) on velocity components, temperature and concentration profiles using the successive Taylor series linearization method (STSLM) utilizing Chebyshev interpolating polynomials and Gauss-Lobatto collocation. The effects of selected parameters on skin friction coefficient, Nusselt number and Sherwood number are also presented with the help of tables. Verification of the STSLM solutions is achieved with existing published results demonstrating close agreement. Further validation of skin friction coefficient, Nusselt number and Sherwood number values computed with STSLM is included using Mathematica software shooting quadrature

Improved Interference-Free Channel Allocation in Coordinated Multiuser Multiantenna Open-Access Small Cells

© 2016 IEEE. This paper investigates low-complexity joint interference avoidance and desired link improvement for single-channel allocation in multiuser multiantenna access points (APs) for open-access small cells. It is considered that an active user is equipped with an antenna array that can be used to suppress interference sources but not to provide spatial diversity. On the other hand, the operation of APs can be coordinated to meet design requirements, where each of which can unconditionally utilize assigned physical channels. Moreover, each AP is equipped with uncorrelated antennas that can be reused simultaneously to serve many active users. The analysis provides new approaches to exploit physical channels, transmit antennas, and APs to mitigate interference, while providing the best possible link gain to an active user through the most suitable interference-free channel. The event of concurrent service requests placed by active users on a specific interference-free channel is discussed for either interference avoidance through identifying unshared channels or desired link improvement via multiuser scheduling. The applicability of the approaches to balance downlink loads is explained, and practical scenarios due to imperfect identification of interference-free channels and/or the scheduled user are thoroughly investigated. The developed results are applicable for any statistical and geometric models of the allocated channel to an active user, as well as channel conditions of interference users. They can be used to study various performance measures. Numerical and simulation results are presented to explain some outcomes of this paper

Prevalence of chronic periodontitis and its risk determinants among female patients in the Aseer Region of KSA

أهداف البحث: لتحديد مدى انتشار التهاب اللثة المزمن ومحدداته بين المرضى في منطقة عسير بالمملكة العربية السعودية. طرق البحث: تم فحص ما مجموعه ١٠٠٠ مريضة جديدة على التوالي بين سن ٢٥- ٧٥ عاما لوجود أي أمراض لثة. وقد شملت الخصائص الديموغرافية المختلفة للمشاركين في الدراسة العمر، والمستوى التعليمي، والمهنة، ووجود داء السكري، ووجود أمراض اللثة في العائلة، وممارسات النظافة الصحية الفمية لكل مشارك، وتم تسجيلها. كما تم تسجيل معلومات نسبة انتشار أمراض اللثة وشدتها. النتائج: من بين هؤلاء المرضى، وُجد أن ٤٥٧ لديهن ما يدل على وجود أمراض اللثة. خضع هؤلاء المرضى لفحص مفصّل للثة. أظهر اختبار مربع كاي لصلاحية الانطباق أن ٤٦.٦٪ لديهن التهاب لثة مزمن محدود في حين أن ٢.٢٪ لديهن التهاب لثة مزمن عام. وقد تراوحت نسبة وجود التهاب اللثة المزمن المحدود من ٤.٢٪ إلى ١٢٪، بينما تراوحت نسبة وجود التهاب اللثة المزمن العام من ٣.١٪ إلى ١٤.٧٪. أظهرت إحصاءات مربع كاي لـ “كروسكال – واليس” اللاممحدودة أن عوامل مثل العمر، والتعليم، والمهنة، وبُعد الزيارة الأخيرة لطبيب الأسنان، ووجود داء السكري، والنزف بمجرد الملامسة بآلة معدنية كانت محددات مخاطر ذات قيمة للإصابة بأمراض اللثة في المجموعة المختارة. الاستنتاجات: أظهر غالبية المرضى وجود التهاب لثة مزمن محدود. ويُعد العمر، والتعليم، والمهنة، وقلة زيارات طبيب الأسنان، ووجود داء السكري محددات خطورة مهمة لحدوث التهاب اللثة المزمن. ينبغي تقييم المعلومات المتعلقة بالمخاطر الفردية لحدوث أمراض اللثة بعناية لغرض المعالجة المناسبة للمرضى، والوصول إلى صحة عامة شاملة أفضل

In vitro models of cancer stem cells and clinical applications

Cancer cells, stem cells and cancer stem cells have for a long time played a significant role in the biomedical sciences. Though cancer therapy is more effective than it was a few years ago, the truth is that still none of the current non-surgical treatments can cure cancer effectively. The reason could be due to the subpopulation called “cancer stem cells” (CSCs), being defined as those cells within a tumour that have properties of stem cells: self-renewal and the ability for differentiation into multiple cell types that occur in tumours. The phenomenon of CSCs is based on their resistance to many of the current cancer therapies, which results in tumour relapse. Although further investigation regarding CSCs is still needed, there is already evidence that these cells may play an important role in the prognosis of cancer, progression and therapeutic strategy. Therefore, long-term patient survival may depend on the elimination of CSCs. Consequently, isolation of pure CSC populations or reprogramming of cancer cells into CSCs, from cancer cell lines or primary tumours, would be a useful tool to gain an in-depth knowledge about heterogeneity and plasticity of CSC phenotypes and therefore carcinogenesis. Herein, we will discuss current CSC models, methods used to characterize CSCs, candidate markers, characteristic signalling pathways and clinical applications of CSCs. Some examples of CSC-specific treatments that are currently in early clinical phases will also be presented in this review

Methotrexate-induced apoptosis in human ovarian adenocarcinoma SKOV-3 cells via ROS-mediated bax/bcl-2-cyt-c release cascading

Gadah AlBasher,1 Abdullah A AlKahtane,1 Saud Alarifi,1 Daoud Ali,1 Mohammed S Alessia,2 Rafa S Almeer,1 Mohamed M Abdel-Daim,3 Nouf K Al-Sultan,1 Ahmed A Al-Qahtani,4,5 Huma Ali,6 Saad Alkahtani1 1Department of Zoology, College of Science, King Saud University, Riyadh, Saudi Arabia; 2Department of Biology, Science College, Al-Imam Muhammad Ibn Saud, Islamic University, Riyadh, Saudi Arabia; 3Department of Pharmacology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, Egypt; 4Department of Infection and Immunity, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia; 5Department of Microbiology and Immunology, Alfaisal University School of Medicine, Riyadh, Saudi Arabia; 6Department of Chemistry Maulana Azad National Institute of Technology, Bhopal, India Introduction: The communication between a substance and a cell may depend on whether the cell is normal or pathological. The disease cells and drug interaction may occasionally overcome beneficial action of the drug; subsequently, it is important to investigate the effect of the drug in both the normal and target cells. This study aimed to evaluate the methotrexate (MTX) antiproliferative effect and explore the mechanistic approach to investigate the cell death index in SKOV-3 ovarian cells during treatment with MTX. Methods: In vitro studies of SKOV-3 cells were examined by tetrazolium assay after exposure to various concentrations of MTX. Moreover, reactive oxygen species (ROS) generation, mitochondrial membrane potential, DNA damage, and AO/EtBr staining morphological analysis of necrotic/apoptotic cells were detected; cellular impairment in mitochondria and DNA was confirmed by JC-1 mitotracker/DAPI, respectively, and cell death pathway markers; bax/bcl-2 were analyzed. Results: A dose-dependent antiproliferative effect of MTX treatment was observed in SKOV-3 cells; the prominent inhibitory concentration was 40 µM of MTX (P<0.01). The growth inhibition rates of the cancer cells reached 24.07% in MTX. The MTX showed increase in ROS generation and mitochondrial depolarization, and DNA integrity cells collectively advocated the apoptotic cell death at higher concentration. In addition, the results of reverse transcription polymerase chain reaction also supported the apoptosis by upregulating the bax and downregulating the bcl-2 (P<0.01). Thus the MTX moderately provokes apoptosis. Conclusion: Our findings suggest that MTX acts on SKOV-3 cancer cells by increasing intracellular ROS levels, leading to DNA damage and altering the MMP along with apoptotic gene upregulation. This mechanism may provide new therapeutic targets to improve tumor treatment. Keywords: methotrexate, MMP, apoptosis, ROS, SKOV-3 cell