INEQUALITIES FOR A POLYNOMIAL WHOSE ZEROS ARE WITHIN OR OUTSIDE A GIVEN DISK

Shah, Lubna Wali,Mir, Mohd Yousf,Shah, Wali Mohammad The Kangwon-Kyungki Mathematical Society 2022 한국수학논문집 Vol.30 No.2

In this paper we prove some results by using a simple but elegant techniques to improve and strengthen some generalizations and refinements of two widely known polynomial inequalities and thereby deduce some useful corollaries.

Low Nourishment of Vitamin C Induces Glutathione Depletion and Oxidative Stress in Healthy Young Adults

Waly, Mostafa I.,Al-Attabi, Zahir,Guizani, Nejib The Korean Society of Food Science and Nutrition 2015 Preventive Nutrition and Food Science Vol.20 No.3

The present study was conducted to assess the status of vitamin C among healthy young adults in relation to serum antioxidant parameters [glutathione (GSH), thiols, and total antioxidant capacity, (TAC)], and oxidative stress markers [malondialdehyde (MDA), and nitrites plus nitrates (NN)]. A prospective study included 200 young adults, and their dietary intake was assessed by using food diaries. Fasting plasma vitamin C, serum levels of GSH, thiols, TAC, MDA, and NN were measured using biochemical assays. It was observed that 38% of the enrolled subjects, n=76, had an adequate dietary intake of vitamin C (ADI group). Meanwhile, 62%, n=124, had a low dietary intake of vitamin C (LDI group) as compared to the recommended dietary allowances. The fasting plasma level of vitamin C was significantly higher in the ADI group as compared to the LDI group. Oxidative stress in the sera of the LDI group was evidenced by depletion of GSH, low thiols levels, impairment of TAC, an elevation of MDA, and increased NN. In the ADI group, positive correlations were found between plasma vitamin C and serum antioxidant parameters (GSH, thiols, and TAC). Meanwhile, the plasma vitamin C was negatively correlated with serum MDA and NN levels. This study reveals a significant increase of oxidative stress status and reduced antioxidant capacity in sera from healthy young adults with low intake of the dietary antioxidant, vitamin C.

Pomegranate (Punica granatum) Peel Extract Efficacy as a Dietary Antioxidant against Azoxymethane-Induced Colon Cancer in Rat

Waly, Mostafa I.,Ali, Amanat,Guizani, Nejib,Al-Rawahi, Amani S.,Farooq, Sardar A.,Rahman, Mohammad S. Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8

Functional foods include antioxidant nutrients which may protect against many human chronic diseases by combating reactive oxygen species (ROS) generation. The purpose of the present study was to investigate the protective effect of pomegranate peel extract (PPE) on azoxymethane (AOM)-induced colon tumors in rats as an in vivo experimental model. Forty Sprague-Dawley rats (4 weeks old) were randomly divided into 4 groups containing 10 rats per group, and were treated with either AOM, PPE, or PPE plus AOM or injected with 0.9% physiological saline solution as a control. At 8 weeks of age, the rats in the AOM and PPE plus AOM groups were injected with 15 mg AOM/kg body weight, once a week for two weeks. After the last AOM injection, the rats were continuously fed ad-libitum their specific diets for another 6 weeks. At the end of the experiment (i.e. at the age of 4 months), all rats were killed and the colon tissues were examined microscopically for lesions suspected of being preneoplastic lesions or tumors as well as for biochemical measurement of oxidative stress indices. The results revealed a lower incidence of aberrant crypt foci in the PPE plus AOM administered group as compared to the AOM group. In addition, PPE blocked the AOM-induced impairment of biochemical indicators of oxidative stress in the examined colonic tissue homogenates. The results suggest that PPE can partially inhibit the development of colonic premalignant lesions in an AOM-induced colorectal carcinogenesis model, by abrogating oxidative stress and improving the redox status of colonic cells.

Red Seaweed (Hypnea Bryodies and Melanothamnus Somalensis) Extracts Counteracting Azoxymethane-Induced Hepatotoxicity in Rats

Waly, Mostafa Ibrahim,Al Alawi, Ahmed Ali,Al Marhoobi, Insaaf Mohammad,Rahman, Mohammad Shafiur Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.12

Background: Azoxymethane (AOM) is a well-known colon cancer-inducing agent in experimental animals via mechanisms that include oxidative stress in rat colon and liver tissue. Few studies have investigated AOM-induced oxidative stress in rat liver tissue. Red seaweeds of the genera Hypnea Bryodies and Melanothamnus Somalensis are rich in polyphenolic compounds that may suppress cancer through antioxidant properties, yet limited research has been carried out to investigate their anti-carcinogenic and antioxidant influence against AOM-induced oxidative stress in rat liver. Objective: This study aims to determine protective effects of red seaweed (Hypnea Bryodies and Melanothamnus Somalensis) extracts against AOM-induced hepatotoxicity and oxidative stress. Materials and Methods: Sprague-Dawley rats received intraperitoneal injections of AOM, 15 mg/kg body weight, once a week for two consecutive weeks and then orally administered red seaweed (100 mg/kg body-weight) extracts for sixteen weeks. At the end of the experiment all animals were overnight fasted then sacrificed and blood and liver tissues were collected. Results: AOM treatment significantly decreased serum liver markers and induced hepatic oxidative stress as evidenced by increased liver tissue homogenate levels of nitric oxide and malondialdehyde, decreased total antioxidant capacity and glutathione, and inhibition of antioxidant enzymes (catalase, glutathione peroxidase, glutathione S-transferase, glutathione reductase and superoxide dismutase). Both red seaweed extracts abolished the AOM-associated oxidative stress and protected against liver injury as evidenced by increased serum levels of liver function markers. In addition, histological findings confirmed protective effects of the two red seaweed extracts against AOM-induced liver injury. Conclusion: Our findings indicate that red seaweed (Hypnea Bryodies and Melanothamnus Somalensis) extracts counteracted oxidative stress-induced hepatotoxicity in a rat model of colon cancer.

Phytonutrient Effects of Date Pit Extract against Azoxymethane-Induced Oxidative Stress in the Rat Colon

Waly, Mostafa Ibrahim,Al-Ghafri, Bushra Rashid,Guizani, Nejib,Rahman, Mohammad Shafiur Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.8

Plants and their by-products offer a diverse mixture of chemical constituents like natural antioxidants. Date-pits are rich in phenolic compounds that have antioxidant potential. The main objective of this study was to investigate the protective effect of a date-pit extract (DPE) against AOM-induced colonic carcinogenicity and oxidative stress. Thirty-two weanling male Sprauge-Dawley rats were randomly divided into four groups (eight rats in each group). All rats were fed basic diet and water ad libitum, and randomly distributed per treatment groups as follows: negative controls injected with normal saline once a week for two weeks, a cancer group injected intra-peritoneally with azoxymethane (15mg/kg body weight) for two consecutive weeks, and DPE treated groups receiving the extract via the oral route (1.5ml/day) for the entire experiment in the presence or absence of AOM injection. Results showed that DPE contained phytonutrients that were capable of inhibiting chemically-induced oxidative stress in the rat colonic cells. In those animals that consumed DPE, a protective effect was observed against AOM-induced oxidative stress in rat colonic cells as evident by a significant decrease in MDA and oxidized DCF formation in AOM injected and DPE fed groups. It is concluded that DPE has potential antioxidant and anticarcinogenic properties.

Optimization of Friction Stir Welding Parameters of AA2014-T6 Alloy using Taguchi Statistical Approach

Wali Muhammad,Wilayat Husain,Anjum Tauqir,Abdul Wadood 대한용접·접합학회 2020 대한용접·접합학회지 Vol.38 No.5

In this study, the Taguchi Design of Experiment method was used to determine the optimal Friction Stir Welding (FSW) parameters for improving the mechanical properties of AA 2014-T6 alloy butt joints. The three most significant parameters - tool rotational speed, tool linear travel speed and tool tilt angle - were optimized using the L9 orthogonal array design. The optimal welding parameters for the maximum tensile strength were determined by analyzing the signal-to-noise (S/N) ratio. A regression model was developed for the desired responses. The optimal tensile strength was achieved at the 1000 rpm, rotational speed, 600 mm/rev welding speed, and 2° tool title angle. The results were confirmed using a steady-state heat transfer model generated from the COMSOL Multiphysics Finite Element software. The identified optimal conditions were verified by experimental validation tests. The experimental results were consistent with the predicted values. Analysis of variance (ANOVA) was conducted to determine the effects of individual parameters and to identify the most significant process parameter. ANOVA indicated that the most significant factor affecting the mechanical behavior of the joint was the tool rotation speed followed by the linear travel speed.

On the bounds of the eigenvalues of matrix polynomials

Wali Mohammad Shah,Zahid Bashir Monga 강원경기수학회 2023 한국수학논문집 Vol.31 No.2

Let $P(z):=\displaystyle{\sum\limits_{j=0}^n} A_jz^j,~A_j\in \mathbb{C}^{m\times m}, 0\leq j\leq n$ be a matrix polynomial of degree $n,$ such that $$A_n\geq A_{n-1}\geq \ldots \geq A_0\geq 0,~A_n>0.$$ Then the eigenvalues of $P(z)$ lie in the closed unit disk. This theorem proved by Dirr and Wimmer [IEEE Trans. Automat. Control \textbf{52}(2007), 2151-2153 ] is infact a matrix extension of a famous and elegant result on the distribution of zeros of polynomials known as Enestr\"om-Kakeya theorem. In this paper, we prove a more general result which inter alia includes the above result as a special case. We also prove an improvement of a result due to L\^{e}, Du, Nguy\^{e}n [Oper. Matrices, \textbf{13}(2019), 937-954] besides a matrix extention of a result proved by Mohammad [Amer. Math. Monthly, vol.74, No.3, March 1967].

Surgical revascularization for Moyamoya disease in the United States: A cost-effectiveness analysis

Wali Arvin R.,Santiago-Dieppa David. R.,Srinivas Shanmukha,Brandel Michael G.,Steinberg Jeffrey A.,Rennert Robert C,Mandeville Ross,Murphy James D.,Olson Scott,Pannell J. Scott,Khalessi Alexander A. 대한뇌혈관외과학회 2021 Journal of Cerebrovascular and Endovascular Neuros Vol.23 No.1

Objective Moyamoya disease (MMD) is a vasculopathy of the internal carotid arteries with ischemic and hemorrhagic sequelae. Surgical revascularization confers upfront peri-procedural risk and costs in exchange for long-term protective benefit against hemorrhagic disease. The authors present a cost-effectiveness analysis (CEA) of surgical versus non-surgical management of MMD. Methods A Markov Model was used to simulate a 41-year-old suffering a transient ischemic attack (TIA) secondary to MMD and now faced with operative versus nonoperative treatment options. Health utilities, costs, and outcome probabilities were obtained from the CEA registry and the published literature. The primary outcome was incremental cost-effectiveness ratio which compared the quality adjusted life years (QALYs) and costs of surgical and nonsurgical treatments. Base-case, one-way sensitivity, two-way sensitivity, and probabilistic sensitivity analyses were performed with a willingness to pay threshold of $50,000. Results The base case model yielded 3.81 QALYs with a cost of $99,500 for surgery, and 3.76 QALYs with a cost of $106,500 for nonsurgical management. One-way sensitivity analysis demonstrated the greatest sensitivity in assumptions to cost of surgery and cost of admission for hemorrhagic stroke, and probabilities of stroke with no surgery, stroke after surgery, poor surgical outcome, and death after surgery. Probabilistic sensitivity analyses demonstrated that surgical revascularization was the cost-effective strategy in over 87.4% of simulations. Conclusions Considering both direct and indirect costs and the postoperative QALY, surgery is considerably more cost-effective than non-surgical management for adults with MMD.

BERNSTEIN-TYPE INEQUALITIES PRESERVED BY MODIFIED SMIRNOV OPERATOR

Shah, Wali Mohammad,Fatima, Bhat Ishrat Ul The Kangwon-Kyungki Mathematical Society 2022 한국수학논문집 Vol.30 No.2

In this paper we consider a modified version of Smirnov operator and obtain some Bernstein-type inequalities preserved by this operator. In particular, we prove some results which in turn provide the compact generalizations of some well-known inequalities for polynomials.

Advances in stable and flexible perovskite solar cells

Qamar Wali,Faiza Jan Iftikhar,Naveen Kumar Elumalai,Yaseen Iqbal,Sidra Yousaf,Shahid Iqbal,Rajan Jose 한국물리학회 2020 Current Applied Physics Vol.20 No.5

Roll-to-roll (R2R) production is an innovative approach and is fast becoming a very popular industrial method for high throughput and mass production of solar cells. Replacement of costly indium tin oxide (ITO), which conventionally has served as the transparent electrode would be a great approach for roll to roll production of flexible cost effective solar cells. Indium tin oxide (ITO) and fluorine-doped tin oxide (FTO) are brittle and ultimately limit the device flexibility. Perovskite solar cells (PSCs) have been the centre of photovoltaic research community during the recent years owing to its exceptional performance and economical prices. The best reported PSCs fabricated by employing mesoporous TiO2 layers require elevated temperatures in the range of 400–500 °C which limits its applications to solely glass substrates. In such a scenario developing flexible PSCs technology can be considered a suitable and exciting arena from the application point of view, them being flexible, lightweight, portable, and easy to integrate over both small, large and curved surfaces.