Fabrication mechanism of nanostructured HA/TNTs biomedical coatings: an improvement in nanomechanical and in vitro biological responses

In this paper, a mechanism for fabrication of nanostructured hydroxyapatite coating on TiO₂ nanotubes is presented. Also, the physical, biological, and nanomechanical properties of the anodized Ti6Al4V alloy consisting TiO₂ nanotubes, electrodeposited hydroxyapatite, and the hydroxyapatite/TiO₂ nanotubes double layer coating on Ti6Al4V alloy implants are compared. Mean cell viability of the samples being 84.63?% for uncoated plate, 91.53?% for electrodeposited hydroxyapatite, and 94.98?% for hydroxyapatite/TiO₂ nanotubes coated sample were in the acceptable range. Merely anodized prototype had the highest biocompatibility of 110?% with respect to the control sample. Bonding strength of hydroxyapatite deposit to the substrate increased from 12?±?2?MPa to 25.4?±?2?MPa using intermediate TiO₂ nanotubes layer. Hardness and elastic modulus of the anodized surface were 956?MPa and 64.7?GPa, respectively. The corresponding values for hydroxyapatite deposit were approximately measured 44.3?MPa and 0.66?GPa, respectively, while the average obtained values for hardness (159.3?MPa) and elastic modulus (2.25?GPa) of the hydroxyapatite/TiO₂ nanotubes double coating improved more than 30?% of the pure hydroxyapatite deposit. Friction coefficient (ξ) of the anodized surface was 0.32?±?0.02. The calculated friction coefficient enhanced from 0.65?±?0.04 for sole hydroxyapatite layer to the 0.46?±?0.02 for hydroxyapatite/TiO₂ nanotubes due to presence of nanotubular TiO₂ intermediate layer.     

Introducing of green garlic plant as a new source of allicin

The presence of allicin in green garlic plant extracts was investigated. Allicin in aqueous extracts from green garlic leaf, shoot and young bulbs were determined by HPLC. Allicin was present at highest level in extracts from whole green garlic plant at 0.48 ± 0.01 mg/mL, followed by that in shoot and leaf extracts at 0.44 ± 0.00 and 0.26 ± 0.01 mg/mL, respectively. The results obtained in this study offer green garlic as a new source of allicin, as green garlic plant is used as a favourite vegetable in many countries.     

Influence of polyethylene glycol on the excretion and digestibility of amino acids in casein and tannic acid‐fed broilers

Using the precision feeding technique, an experiment was conducted to evaluate the influence of tannic acid (TA) and polyethylene glycol (PEG) on the excretion of amino acids and the apparent and true digestibilities of casein protein in broilers. Seventy‐two 9‐week‐old broiler cockerels grouped in nine treatments of eight replicates were fed warm water (50 mL, control birds), casein alone (12 or 18 g) or casein (12 or 18 g) with TA solution (4.5 g per 10 mL) or/and PEG solution (2 g per 10 mL). Total excreta were collected for 48 h and freeze‐dried. The amino acid content of casein and excreta was determined by reverse phase high‐performance liquid chromatography. In the absence of TA the digestibility of casein was almost complete. TA increased the excretion of amino acids to a varying extent (P < 0.01). Although the digestibility of all essential and non‐essential amino acids was adversely affected by the presence of TA, raising the amount of casein from 12 to 18 g improved significantly (P < 0.05) the apparent and true digestibilities of all amino acids. PEG reduced significantly (P < 0.01) the excretion of amino acids and improved significantly (P < 0.01) the amino acid digestibility of casein in TA‐dosed birds. However, the improvement was greater when the lower level of casein (12 g) was fed. Thus PEG might play an important role in inactivating dietary tannins in the gastrointestinal tract of birds and improving protein digestibility and utilisation, particularly when the diet is low or intermediate in protein. Copyright © 2007 Society of Chemical Industry     

A Comparative Assessment of Support Vector Machines,Probabilistic Neural Networks,and K-Nearest Neighbor Algorithms for Water Quality Classification

Water quality is one of the major criteria for determining the planning and operation policies of water resources systems. In order to classify the quality of a water resource such as an aquifer, it is necessary that the quality of a large number of water samples be determined, which might be a very time consuming process. The goal of this paper is to classify the water quality using classification algorithms in order to reduce the computational time. The question is whether and to what extent the results of the classification algorithms are different. Another question is what method provides the most accurate results. In this regard, this paper investigates and compares the performance of three supervised methods of classification including support vector machine (SVM), probabilistic neural network (PNN), and k-nearest neighbor (KNN) for water quality classification. Using two performance evaluation statistics including error rate and error value, the efficiency of the algorithms is investigated. Furthermore, a 5-fold cross validation is performed to assess the effect of data value on the performance of the applied algorithms. Results demonstrate that the SVM algorithm presents the best performance with no errors in calibration and validation phases. The KNN algorithm, having the most total number and total value of errors, is the weakest one for classification of water quality data.     

Flood Vulnerability Analysis by Fuzzy Spatial Multi Criteria Decision Making

Prioritization the sub-basins available in a basin to flood vulnerability analysis can be discussed in the form of a spatial multi criteria decision making (SMCDM) problem. In this research a fuzzy planning support system based on the spatial analysis using tow multi criteria decision making methods, Analytic Hierarchy Process (AHP) and TOPSIS (Technique for order-preference by similarity to ideal solution) is used. AHP method is used to determine the structure of decision making process and to estimate criteria weights and TOPSIS model is used to rank the sub-basins of Tehran urban basin as a study area regarding the flood vulnerable areas. Also in order to perform spatial analysis for decision-making process, a developed toolbox is used within the Geographic Information System (GIS). In this research a model is presented in which some vague concepts such as weight of decision making criteria are expressed in the form of linguistic variables to be converted to triangular fuzzy numbers. Finally, the sensitivity of model was analyzed by changing the weights of decision making criteria and providing of ranking scenarios. The results show the optimum alternatives for mitigation flood vulnerability in the study area.

     

The reliability and validity of self-reported puffing behavior: evidence from a cross-national study.

Self-reported puffing behavior has considerable potential as an indicator of smoking intensity, particularly in survey research evaluating population-based changes in smoking patterns. However, little is known about the reliability and validity of self-reported puffing behavior. This study compared smokers' perceptions of their puffing behavior with measures of both machine-determined puffing behavior and nicotine uptake to assess the utility of self-report. We assessed self-reported puffing behavior as well as demographic and smoking characteristics of 118 smokers from Australia, Canada, the United Kingdom, and the United States. At two visits, participants were asked to provide a saliva sample and to smoke a cigarette through a portable smoking topography device, the CReSSmicro, to measure puffing behavior. Saliva samples were assayed for cotinine, a measure of nicotine uptake, to provide estimates of smoke exposure. Intraclass coefficients for all measures of self-reported general puffing behavior were above .6, indicating that self-reported measures had fair-to-good test-retest reliability. Self-report, in particular of interpuff interval and number of cigarette puffs, was correlated only moderately with machine-determined puffing measures (.2相似文献   

Transform domain inter-block interleaving schemes for robust image and video transmission in ATM networks

Data interleaving schemes have proven to be an important mechanism in reducing the impact of correlated network errors on image/video transmission. Current interleaving schemes fall into two main categories: (a) schemes that interleave pixel intensity values and (b) schemes that interleave JPEG/MPEG transform blocks. The schemes in the first category suffer in terms of lower compression ratio since highly correlated information in the spatial domain is de-correlated prior to compression. The schemes in the second category interleave DCT transformed blocks. In this case, in the absence of ARQ, if a packet is lost, an entire block may be lost thus yielding poor image quality and making the error concealment task difficult. Interleaving transform coefficients is tricky and error concealment in the presence of lost coefficients is challenging. In this paper, we develop three different interleaving schemes, namely Triangular, Quadrant, and Coefficient, that interleave frequency domain transform coefficients. The transform coefficients within each block are divided into small groups and groups are interleaved with the groups from other blocks in the image, hence they are referred to as inter-block interleaving schemes. The proposed schemes differ in terms of group size. In the Triangular interleaving scheme AC coefficients in each block are divided into two triangles and interleaving is performed among triangles from different blocks. In the Quadrant interleaving scheme, coefficients in each block are divided into four quadrants and quadrants are interleaved. In the Coefficient interleaving scheme, each coefficient in a block is a group and it is interleaved with the coefficients in other blocks. The compression ratio 3 of the proposed interleaving schemes is impressive ranging from 90 to 98% of the JPEG standard compression while providing much higher robustness in the presence of correlated losses. We also propose two new variable end-of-block (VEOB) techniques, one based on the number of AC coefficients per block (VAC-EOB) and the other based on the number of bits per block (VB–EOB). Our proposed interleaving techniques combined with VEOB schemes yield significantly better compression ratios compared to JPEG (2–11%) and MPEG-2 (3–6.7%) standards while at the same time improve the resilience of the coded data in the presence of transmission errors.