131 research outputs found
Cytotoxic Effect of Turkish Propolis on Liver, Colon, Breast, Cervix and Prostate Cancer Cell Lines
Purpose: To investigate the total polyphenolic and flavonoid contents, antioxidant power and cytotoxic activity of ethanol extracts of Turkish propolis (EEP).Methods: The total polyphenolic and flavonoid contents of EEP were determined by spectrometric methods. Antioxidant power and cytotoxic activity of EEP were evaluated using ferric reducing antioxidant power (FRAP) and MTT assays, respectively.Results: The total polyphenolic and flavonoid contents, and FRAP value of EEP were 124.6 ± 1.5 mg gallic acid/g sample dry weight , 42.0 ± 0.8 mg quercetin/g sample dry weight and 311.0 ± 2.5 mg trolox/g sample dry weight, respectively. EEP exhibited powerful cytotoxic effects against the five human cancer cell lines. The highest cytotoxic activity of Turkish EEP was demonstrated on PC-3 cell line (IC50 = 20.7±3.4 μg/mL).Conclusion: The results demonstrate that EEP is a good source of antioxidant and a natural antitumor agent capable of reducing cancer cell proliferation.Keywords: Propolis, Polyphenols, Cytotoxic effect, Cancer cell lines, Antioxidant activity Tropical Journal of Pharmaceutical Research is indexed by Science Citation Index (SciSearch)
An investigation of heuristic decomposition to tackle workforce scheduling and routing with time-dependent activities constraints
This paper presents an investigation into the application of heuristic decomposition and mixed-integer programming to tackle workforce scheduling and routing problems (WSRP) that involve timedependent activities constraints. These constraints refer to time-wise dependencies between activities. The decomposition method investigated here is called repeated decomposition with con ict repair (RDCR) and it consists of repeatedly applying a phase of problem decomposition and sub-problem solving, followed by a phase dedicated to con ict repair. In order to deal with the time-dependent activities constraints, the problem decomposition puts all activities associated to the same location and their dependent activities in the same sub-problem. This is to guarantee the satisfaction of time-dependent activities constraints as each sub-problem is solved exactly with an exact solver. Once the assignments are made, the time windows of dependent activities are fixed even if those activities are subject to the repair phase. The paper presents an experimental study to assess the performance of the decomposition method when compared to a tailored greedy heuristic. Results show that the proposed RDCR is an effective approach to harness the power of mixed integer programming solvers to tackle the diffcult and highly constrained WSRP in practical computational time. Also, an analysis is conducted in order to understand how the performance of the different solution methods (the decomposition, the tailored heuristic and the MIP solver) is accected by the size of the problem instances and other features of the problem. The paper concludes by making some recommendations on the type of method that could be more suitable for different problem sizes
The Glenoid and Humeral Head in Shoulder Osteoarthritis:A Comprehensive Review
The key management of glenohumeral osteoarthritis is shoulder arthroplasty which aims to reduce pain and restore full shoulder function: it has increased in recent years. A detailed understanding of the anatomy of the glenoid and humeral head, as well as morphological changes of the glenoid in osteoarthritis, are important factors to consider when deciding on replacement components. This review begins with a brief introduction of the glenohumeral joint itself, and then considers the detailed anatomy of the glenoid fossa and humeral head, both of which are reported to have variable morphology. Several studies have been undertaken to assess various parameters, especially of the glenoid fossa including its shape, height, width, and articular surface area, version and inclination, in an attempt to define a standard classification that can be applied to surgical intervention. Nevertheless, no definitive consensus concerning the classification of these morphologies has been forthcoming, hence the need for this review. Following a consideration of these morphologies, the current state of knowledge regarding glenoid deformity in osteoarthritis, as well as its surgical management, is considered.</p
Temperature change in pig rib bone during implant site preparation by low-speed drilling
OBJECTIVES: The purpose of this study was to evaluate the temperature change during low-speed drilling using infrared thermography. MATERIAL AND METHODS: Pig ribs were used to provide cortical bone of a similar quality to human mandible. Heat production by three implant drill systems (two conventional drilling systems and one low-speed drilling system) was evaluated by measuring the bone temperature using infrared thermography. Each system had two different bur sizes. The drill systems used were twist drill (2.0 mm/2.5 mm), which establishes the direction of the implant, and finally a 3.0 mm-pilot drill. Thermal images were recorded using the IRI1001 system (Infrared Integrated Systems Ltd.). Baseline temperature was 31±1ºC. Measurements were repeated 10 times, and a static load of 10 kg was applied while drilling. Data were analyzed using descriptive statistics. Statistical analysis was conducted with two-way ANOVA. RESULTS AND CONCLUSIONS: Mean values (n=10 drill sequences) for maximum recorded temperature (Max TºC), change in temperature (ΔTºC) from baseline were as follows. The changes in temperature (ΔTºC) were 1.57ºC and 2.46ºC for the lowest and the highest values, respectively. Drilling at 50 rpm without irrigation did not produce overheating. There was no significant difference in heat production between the 3 implant drill systems (p>0.05). No implant drill system produced heat exceeding 47ºC, which is the critical temperature for bone necrosis during low-speed drilling. Low-speed drilling without irrigation could be used during implant site preparation
Predictors of homelessness among vulnerably housed adults in 3 Canadian cities: a prospective cohort study
Controle nebuloso adaptativo por modelo de referência: projeto e aplicação em sistemas não lineares
Critical Oscillation Constant for Euler Type Half-Linear Differential Equation Having Multi-Different Periodic Coefficients
We compute explicitly the oscillation constant for Euler type half-linear second-order differential equation having multi-different periodic coefficients
Oscillation and nonoscillation of half-linear Euler type differential equations with different periodic coefficients
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