Title: Six months monomer elution from silorane and two dental composites with high-molecular-weight monomers in the polymer matrix composition

Abstract:Objective The process of elution of unreacted monomers from dental resin composites can adversely affect their biocompatibility and longevity. One of the main factors, related to the elution process is the resin matrix composition. Nearly over the last decade, more successful work has been done on changing the polymer matrix of resin composites, dictated mainly by the idea of reducing the polymerization shrinkage. The silorane composite and the group of resin composites, with the presence of high molecular weight dimethacrylate monomers, were created. In this regard, it is of interest to monitor the influence of the matrix changes on the elution of unreacted monomers and the biodegradation of dental resin composites. Materials and methods: This study aimed to assess long-term monomer elution from silorane based (Filtek Silorane LS ) and high molecular weight (Kalore, Venus Diamond) resin composites stored in artificial saliva for 6 mounds. Analysis of monomer elution was performed using high-performance mass spectrometry in combination with ultra-high performance chromatography (HPLC-MS), effects of aging were visualized by Scanning Electron Microscopy (SEM). Results: Monomers detected in artificial saliva were: Urethane dimethacrylate (UDMA) from Kalore and Venus Diamond, 2-isopropyl thioxanthone(ITX) from Kalore, and Lauryl Methacrylate( LMA) from Venus Diamond. No eluted monomers were detected from Filtek Silorane LS. SEM analysis of the surfaces of the materials showed erosion, cracks, and roughing of all studied materials after 6 mounds of aging. Conclusions: Monomer elution is a long process. It starts at 24 hours and continues for some substances for up to 6 months. For some monomers, elution starts after a few days. Despite the lack of extracted products from silorane composite in artificial saliva, SEM shows surface degradation.


Abstract:The plant Solanum nigrum Linn which belongs to Solanacea family, commonly called as black night shade in English, Mako in Urdu, Manattakkali in Tamil and Kalukammeriya in Sinhala. It is distributed throughout tropical and temperate regions of the world. It possess various compounds like flavonoids, alkaloids, saponins, tannins, glycosides, terpenoids, proteins, carbohydrates, acetic compounds, resin. It does not have sterols, steroids and anthraquinones which are responsible for its diverse activities. Numerous preclinical investigations identified a variety of potential health benefits, including Hepatoprotective activity, Nephroprotective activity, Anti-diabetic activity, Anti-inflammatory activity, Anti-cancer or Anti tumour activity, Anti-oxidant activity, Antimicrobial activity, Antihyperlipidemic activity. Further human studies needed to find the safety and efficacy of Mako.


Abstract:Negative Bias Temperature Instability (NBTI) is an important reliability issue in CMOS devices which affects the performance of CMOS-based circuits. In this paper, the effects of NBTI have been analyzed on the 6T SRAM cell circuit designed using 16 nm FinFET technology. The performance affected by the NBTI reliability issues in terms of propagation delay and power consumption in both operations which is the read and write operations were studied. The 6T SRAM performance was investigated based on different defect mechanisms, stress times and operating temperature conditions. There is about 74 mV difference between the threshold voltage shift calculated using defects due to Nit and Nit combined with Not. The read delay was found to be unaffected by the stress time while the write delay improved marginally during the 10 years stress time. The write delay of the 6T SRAM cell simulated using the Nit improved 0.4% after 10 years operation as compared to when simulated using the Nit combine with Not. At 125°C, the power consumption after 10 years operation for read operation was higher than the write operation which is 4.09 µW and 0.443 respectively. The performance of the 6T SRAM cell was observed to be reliant on the type of defect mechanism, the static and dynamic simulation conditions as well as the operating temperature.

Title: Prevention of Vitamin D Deficiency and Osteoporosis

Abstract:It is well-known that vitamin D status impacts on the mineralization of the skeleton, bone turnover rate, and the occurrence of fractures. Numerous studies have shown a direct relationship between a low serum level of vitamin D and a low bone mineral density (BMD) and an increased risk of non-vertebral and hip fractures. Importantly, vitamin D status is essential for the generation of maximal bone mass and along with other risk factors can largely contribute the development of osteoporosis and other bone metabolic diseases, such as osteomalacia and rickets in children. Among bone metabolic disorders, osteoporosis is the most common chronic skeletal disease with high morbidity and mortality rates and its healthcare costs impose a significant economic burden. The effective prevention of vitamin D deficiency and osteoporosis can be achieved with the timely identification of individuals with an increased risk and appropriate dietary intervention. In this review, the rationale for identifying those at risk for vitamin D deficiency and subsequent osteoporosis was presented on the basis of evolutionary medicine principles. Moreover, we have highlighted the possibility of using selected plants as natural sources of vitamin D for reducing the incidence of vitamin D deficiency. Several other plant-derived compounds, such as phytoestrogens, flavonoids, and polyphenols, which exhibited protective effects on bone metabolism, were also explored for their potential use for nutritional prevention of osteoporosis.

Title: Investigation of Basic Blue 41 removal by waste product from the phosphate industry: batch design and regeneration

Abstract:The product wastes regenerated after the washing of natural phosphate rocks was proposed as a removal agent of a colored basic blue 41 dye (BB-41) from artificially contaminated solution. The effect of calcination of these materials was also investigated on their removal properties. These materials were characterized beforehand, as is intended for the removal tests, by chemical analysis, powder XRD, FTIR spectroscopy, TGA-DTA, SEM, and N2 adsorption isotherms. The experimental data indicated that the phosphate waste rocks had higher removal capacity of 93 mg g-1 of BB-41 than the pristine rock with a value of 24 mg/g of BB-41. Upon calcination, the removal capacities reduced by 60 to 70%. The equilibrium data were fitted to four models of isotherms and the experimental data were best fitted to Freundlich model. Meanwhile, Langmuir model was used to estimate the maximum removal capacity of the different solids. \nSemi-empirical theoretical calculations provided a new insight into the removal mechanism as a principle of hydrogen bonding and ionic interaction. The regeneration of the spent products indicated that 80% to 60% removal efficiency was maintained after four cycles, depending on the spent of by products. To close the gap between the theoretical isotherm modeling and the design of single-stage batch absorber, the findings from Freundlich equation was suggested as a design approach for BB-41 removal.

Title: The Interaction between the Free End of the Sewing Needle and Top Layer of the Sewn Fabric

Abstract:In the present work a sewing needle of standard and commercial type is selected to carry out the required technological function during sewing process. The sewing technology consist of needle penetration in the different layer of the sewn fabric where the needle is subject to a resisting force that can lead to the buckling of the needle. In the present work we will concentrate on the interaction between the lower end of the needle and the top layer of the sewn fabric. Its database will be used to have numerical values for the needle geometrical characteristics that will be associated by needle buckling mechanics. For example length of needle = 60mm (0.06m), cross section (CSA) is constant with F= 1.965 (E-3) m &of; bending stiffness EI = 2.52 N.m2. It’s found that the buckling characteristics of the needle is: P_cr = 104 N, Euler load P_e = 415 N, equivalent length coefficient γ=√(P_e/P_(cr.) )=2, and the elastic stability factor η`=π^2/4 . The elastic buckled line equation of the buckled needle is:\nX=δ [{1-cos⁡γy }] \n=δ [{1-cos⁡〖πy/2l〗 }]

Title: The main features of global photosynthesis and its evolution in the global carbon turnover

Abstract:Global photosynthesis is the key element of the recently proposed global carbon \ncycle model. It describes an integral action of ensemble of photosynthesizing \norganisms in large systems, like biosphere and global carbon cycle. At least two \nmain features associated with the participation of global photosynthesis in large \nsystems, differs it from conventional photosynthesis of individual organism. The first \nis the cyclic character of the photosynthesis evolution, and the second is spontaneous \nstriving of global photosynthesis to the ecological compensation point that brings the\ncarbon cycle to a stationary state. It is shown that the conventional photosynthesis \nequation should be modified to describe this process in the biosphere and in the \nglobal carbon cycle. The terms “living matter” and \"sedimentary organic carbon\" \nwere used as an analog of biomass in the equation of global photosynthesis. \nCorresponding changes were made to describe the second product of global \nphotosynthesis-atmospheric oxygen. Considering that the global carbon cycle \nreached the ecological compensation point that occurred in the Miocene, when the \nfurther accumulation of oxygen in the atmosphere and sedimentary organic matter in \nthe earth\'s crust ended, the obtained approximate equations of photosynthesis were \nused to estimate the world’s potential oil resources. To test the predictive capability \nof the model we compared the above characteristic with its analogue, the world\'s \ninitial summary resources, calculated by independent geological methods. In spite of \nvarious assumptions a surprising proximity was found. It evidences that the model \nitself and underlying physical foundations are realistic and can be used as \napproximation in solving different problems in geology, evolution, climatology and \nrelated fields of knowledge.

Title: Influence of nonreciprocity of media on the properties of standing waves of linear and elliptical polarization

Abstract:The model of the ionosphere is considered as a layer of plasma in a magnetic field. An equation is obtained for standing waves with elliptical polarization, formed by various sources of electromagnetic radiation in a magnetized plasma. It is found that the condition for synchronous oscillations of adjacent points of a standing wave between the nearest nodes change to the condition for synchronous rotation of the tension vectors in a plane perpendicular to the direction of wave propagation. It is shown that external influences on wave processes lead to nonreciprocity of propagation conditions for forward and backward waves. Generalized equations for quasi-stationary waves of linear and elliptical polarization are obtained. It was found that the conditions for the formation of standing waves are violated and pulsating, quasi-stationary waves are formed, in which the nodes are displaced and the synchronism of oscillations of neighboring points between the nearest nodes for waves of linear polarization and the synchronism of rotation of the vectors of the electromagnetic field in standing waves of elliptical polarization are disturbed.

Title: The effects of market orientation on the performance of Vietnamese startups: A case study in Hanoi

Abstract:The study of the impact of market orientation on the performance of Vietnamese startups was conducted based on the collection of survey data from 271 startups in Hanoi that were established in the period 2016 - 2018. Data collection was carried out from November 2019 to May 2020. Collected data was processed on SPSS20 software and estimated by linear regression method count. In this study, the authors consider the impact of factors in market orientation including (1) competitor orientation; (2) customer orientation; (3) the inter-functional coordination orientation and startup characteristics such as seniority, how field of activity affect startup performance. On that basis, the study proposes a number of suggestions to lead to the success of start-ups in Hanoi in particular and in Vietnam in general.

Title: Effect of Induced Hyperprolactinemia on The Thymus Glands: A Histological and Immunohistochemical Study

Abstract:Background: Prolactin is a protein hormone, as well as a cytokine, which is synthesized and secreted from specialized cells of the anterior pituitary gland, named lactotrophs. as well as the fact that PRL is synthesized in many extrapituitary tissues. Among these sites of PRL synthesis are cells of the immune system, such as macrophages, natural killers, and T- and B-lymphocytes. Aim: This study aimed to demonstrate the histological and immunohistochemical alterations of the thymic gland T- cells in hyperprolactinemic adult male mice for different durations. Experimental design: Fifty mice were divided into five groups; group I: control mice, groups II, III, IV and V: were injected i.p. with metoclopramide for different durations 2, 4, 7 and 10 weeks, respectively. Results: A highly significant hyperprolactinemia and gradual significant increase in the body weight of mice groups II, III, IV and V was recorded. hyperprolactinemia mice group II for 2 weeks showed slight histological alterations in mice thymus tissues. hyperprolactinemia mice group III for 4 weeks illustrated a marked severe thymic involution .While hyperprolactinemia mice groups IV and V for 7 and 10 weeks illustrated clearly histological changes in the thymic tissues and their change were a time dependent. IHC study expressed intense immunoreactivity to CD4+/ CD8+ T-cells (helper and cytotoxic T cells, respectively) in the thymus tissue of control group (I) while in all hyperprolactinemia mice groups (II-V), CD4+/ CD8+ T-cells immunostain were markedly reduced. In conclusion, the present study revealed that HPRL lead to histological alterations in the thymus glands that were time- dependent, and subsequently lead to highly significant decrease in CD4+/ CD8+ T-cells. Therefore, metoclopramide should not be used for long duration, and must be used with caution as a therapy.