1,547 research outputs found
NEUROTOXIC EFFECT OF TITANIUM DIOXIDE NANOPARTICLES: BIOCHEMICAL AND PATHOLOGICAL APPROACH IN MALE WISTAR RATS
Objective: Titanium dioxide nanoparticles (TiO2 NPs) are widely used in pharmaceutical, cosmeceutical, biomedical and industrial applications. The adverse effects of TiO2 NPs are also increasing alarmingly. The purpose of this study is to investigate the toxicity of TiO2 NPs on biochemical and histological changes in different regions of brain in adult male Wistar rats.Methods: Two different doses of TiO2 NPs (50 mg/kg b. w and 100 mg/kg b. w) administered orally for 14 d along with one control group, each group consisting of six animals. Standard biochemical methods were adopted for the estimation of enzymes alkaline phosphatase, 5' nucleotidase, ATPases and gamma-glutamyl transpeptidase. Trace elements calcium, sodium, potassium and magnesium as well as metals like iron, zinc and copper were also estimated.Results: When compared with the control group, the enzymes ATPases, ALP, 5'-NT and GGT activities were significantly decreased in both the TiO2 NPs treated groups. Ca, Na, Fe, Cu and TiO2 contents were significantly increased in both the experimental groups, while the K, Mg and Zn contents decreased. However, the changes in the parameters studied were more in 100 mg treated group (p<0.001) when compared to the 50 mg treated group (p<0.05and p<0.01). Moreover, it is also evident that different regions responded differently due to TiO2 NPs exposure. The changes were maximum in the cerebral hemisphere (p<0.001) followed by medulla oblongata (p<0.001) and cerebrum (p<0.05).Conclusion: The results clearly imply that TiO2 NPs could impair the electrochemical gradient, ionic homeostasis and membrane stability in different regions of the rat brain
Optimization of Machining Parameters in Turning Operations for Surface Roughness and Materials Removal Rate on EN8 through Combined SSA GA Algorithm
For many industrial machining operations, the quality of surface finish is the prominent requirement. Nevertheless the selection of optimized cutting parameters is very essential for controlling the desired surface quality. Main aim of this attempt is to fix the set of cutting parameters combinations using optimization algorithms. Ant Colony algorithm, Scatter Search algorithm, Genetic algorithm and BAT algorithm were used for various parameters on the surface roughness to arrive a suitable combination of parameters which are optimal to meet the product quality requirement. The effectiveness of the algorithms is ordered based up on the error rate while computing and the best two algorithms are combined for more tuned outcome
Typestate verification: Abstraction techniques and complexity results
AbstractWe consider the problem of typestate verification for shallow programs; i.e., programs where pointers from program variables to heap-allocated objects are allowed, but where heap-allocated objects may not themselves contain pointers. We prove a number of results relating the complexity of verification to the nature of the finite state machine used to specify the property. Some properties are shown to be intractable, but others which appear to be quite similar admit polynomial-time verification algorithms. Our results serve to provide insight into the inherent complexity of important classes of verification problems. In addition, the program abstractions used for the polynomial-time verification algorithms may be of independent interest
An exploratory study of ERM perception in Oman and proposing a maturity model for risk optimization
Enterprise Risk management is a process vital to enterprise governance which has gained tremendous momentum in modern business due to the dynamic nature of threats, vulnerability and stringent regulatory requirements. The business owners have realized that, risk creates opportunity which in turn creates value. Identifying and mitigating risk proactively across the enterprise is the purview of Enterprise Risk Management (ERM).However, key errors in the ERM process such as misinterpretation of statistical data, overlooking change management, inadequate attention to supply chain interdependencies, excessive trust of insiders and business partners, ambiguous grouping of risks and poor documentation has contributed significantly to the failure of ERM. To examine the ERM perception in Oman, the authors have conducted a survey among various risk management practitioners. Based on the findings, the authors have broadly classified risk into three types namely business risks, technical risks and regulatory risks and threat vs. consequence mapping is defined to provide direction to moderately group risks. Further, this article defines various ERM approaches including due diligence, probabilistic risk analysis, scenario-based analysis and system analysis which offers a wide range of decision-support tools to the management
Fully-dynamic Approximation of Betweenness Centrality
Betweenness is a well-known centrality measure that ranks the nodes of a
network according to their participation in shortest paths. Since an exact
computation is prohibitive in large networks, several approximation algorithms
have been proposed. Besides that, recent years have seen the publication of
dynamic algorithms for efficient recomputation of betweenness in evolving
networks. In previous work we proposed the first semi-dynamic algorithms that
recompute an approximation of betweenness in connected graphs after batches of
edge insertions.
In this paper we propose the first fully-dynamic approximation algorithms
(for weighted and unweighted undirected graphs that need not to be connected)
with a provable guarantee on the maximum approximation error. The transfer to
fully-dynamic and disconnected graphs implies additional algorithmic problems
that could be of independent interest. In particular, we propose a new upper
bound on the vertex diameter for weighted undirected graphs. For both weighted
and unweighted graphs, we also propose the first fully-dynamic algorithms that
keep track of such upper bound. In addition, we extend our former algorithm for
semi-dynamic BFS to batches of both edge insertions and deletions.
Using approximation, our algorithms are the first to make in-memory
computation of betweenness in fully-dynamic networks with millions of edges
feasible. Our experiments show that they can achieve substantial speedups
compared to recomputation, up to several orders of magnitude
Calvarial bone defect regeneration using beta-tricalcium phosphate: a translational research study in rat animal model
Background: Guided bone regeneration (GBR) using osteoconductive graft materials has been used for osseous defect healing. The aim of this translational research study was to design and test a critical size calvarial defect (CSD) model in rats, to test GBR with beta-tricalcium phosphate (beta-TCP), using histology and micro computed tomography (micro-CT) assessment.Methods: Female Wistar albino rats (n=10) weighing 300 grams and aged 6-weeks were used and full thickness CSD were created in calvaria following exposure under general anesthesia. CSD were randomly divided into two groups for treatment, based on defect filling material: control group (no graft placed in defect; n=5); and beta-TCP group (defect grafted with beta-TCP; n=5). Both defects were covered with collagen membrane. After 8-weeks of healing the animals were sacrificed and calvarial specimens were subjected to micro-CT and histological assessment.Results: Based on micro-CT the new bone volume (NBV) was significantly higher in beta-TCP group (3.48±0.27 mm3; p<0.05), than control group (2.88±0.33 mm3). Similarly, new bone mineral density (NBMD) was significantly higher in beta-TCP group (0.426±0.018 g/mm3; p<0.01), than control group (0.243±0.015 g/mm3). Histology revealed greater new bone bridging the entire defect with interspersed graft particles in the beta-TCP group.Conclusions: Within the limitations of the present study, GBR of rat calvarial CSD with beta-TCP and collagen membrane, results in significantly higher NBV and NBMD, and is a reliable and reproducible translational research model
SVtL: System Verification through Logic: tool support for verifying sliced hierarchical statecharts
SVtL is the core of a slicing-based verification environment for UML statechart models. We present an overview of the SVtL software architecture. Special attention is paid to the slicing approach. Slicing reduces the complexity of the verification approach, based on removing pieces of the model that are not of interest during verification. In [18] a slicing algorithm has been proposed for statecharts, but it was not able to handle orthogonal regions efficiently. We optimize this algorithm by removing false dependencies, relying on the broadcasting mechanism between different parts of the statechart model
Alterations of serum high sensitive C reactive protein and lipid levels in newly diagnosed myocardial infarction subjects
Background: Acute Myocardial Infarction (AMI) is one of the major causes of mortality in the world. Atherosclerosis leading to AMI is the most common and severe clinical manifestation observed. Dyslipidemia is one of main traditional risk factor for MI, but in more than 50% of CHD events dyslipidemia was absent. Atherosclerosis is considered as both a chronic inflammatory condition and a disorder of lipid metabolism. The present study was aimed to estimate the levels of serum lipids (total cholesterol, LDL cholesterol, HDL cholesterol) and hs-CRP an inflammatory marker in newly diagnosed AMI cases and to find out any correlation between these two.Methods: The study was conducted on 50 newly diagnosed myocardial infarction cases, admitted in Cardiology Department Narayana Medical College, Nellore. Both the sexes were included. Fifty age and sex matched healthy individuals were selected as controls. Lipid levels are estimated by end point colorimetric assay (HUMANSTAR kit) and hs-CRP was estimated by immunofluorescence technique (Boditechkit).Results: Significant raised levels of hs-CRP (p value <0.0001) and low HDL cholesterol (p value =0.0085) levels among the cases was noticed. A significant positive correlation was observed between LDL cholesterol and hsCRP (r=0.109, p=0.040). A non-significant positive correlation between hsCRP and HDL cholesterol (r=0.291, p=0.453) was observed.Conclusions: The results of the study implicate the role of inflammatory component in causing atherosclerosis or coronary artery disease rather than dyslipidaemias alone to be attributed for atherogenesis. Concomitantly HDL cholesterol levels were found to be low in cases that results from the inflammatory component in atherogenesis
Numerical Prediction of Gas Pulsation in a Scroll Compressor Using 1-D Modeling: A Validation Study Based on AHRI Standard 530-2011
Chemical profiling of fern Cheilosoria mysurensis (Wall. ex Hook.) Ching & Shing and its biological activity
Cheilosoria mysurensis (Wall. ex Hook.) Ching & Shing, a medicinal fern traditionally used to treat burns, throat pain and bone fracture. There is no any scientific report regarding anticancer studies of this species. The aim of the study was to find out the chemical components through GC/MS analysis with their antioxidant and cytotoxic activity. GC-MS analysis shows primary ingredients viz, Cis-9, 10-epoxyoctadecan-1-ol and Oxiraneundecanoic acid, 3-pentyl-, methyl ester, trans were present. High free-radical scavenging activity has been discovered in 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and showed the IC50 value of 52.13±0.33. Furthermore, C. mysurensis also showed good cytotoxic effects against DLA and EAC cell lines with values of 72.9% and 79.5% at 200 µg/ml dose respectively. Overall findings suggested that the identified chemical compounds proved to be rich in antioxidant property. Further, this fern can be a good resource for pharma industry to produce novel anti-cancer drugs
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