HYDROGEN SULFIDE PRODUCTION BY HEATING DIFFERENT PROTEIN FRACTIONS OF TUNA MEAT

Raw albacore tuna was separated into water-soluble and water-insoluble fractions. The water-soluble fraction was separated into two fractions by trichloroacetic acid (2.5%). The water-insoluble fraction was extracted with NaCl (0.45 M), and then the insoluble fraction was further extracted with urea solution (6 M). H₂S production upon heating of each fraction was determined by the reflux-trap technique. Water-soluble proteins produced 71% of the H₂S, while the corresponding contribution from the insoluble fraction was 29%. Non-protein soluble components and salt-soluble proteins produced insignificant amounts of H₂S. Significant increase in the amount of H₂S was observed when water-insoluble proteins were treated with urea and TCA solutions.     

EFFECT OF TEMPERATURE DURING POST-MORTEM GLYCOLYSIS AND DEPHOSPHORYLATION OF HIGH ENERGY PHOSPHATES ON POULTRY MEAT TENDERNESS

SUMMARY– Tests made on pectoralis major muscles having post-slaughter pH values ranging between 6.1–7.0, indicated that holding poultry meat at 30 and 37°C during the onset of rigor mortis caused toughness. This toughening effect of high temperature appeared to occur when the pH level of the meat dropped from a value of about 6.3 to its ultimate low value and the adenosine triphosphate content dropped below 40% of its initial concentration. Holding temperatures at 10, 15 and 25°C during the onset of rigor mortis, or cooling to 15°C before the pH value dropped to about 6.3 produced more tender meat. After completion of post-mortem glycolysis and dephosphorylation of high energy phosphates, high temperature had no deleterious effect on tenderness. These results indicate that dephosphorylation of adenosine triphosphate at high temperature affects the mode or extent of stiffening of the muscular tissue and prevents tenderization.     

基于注意力改进BiGRU的锂离子电池健康状态估计

锂离子电池的健康状态(state of health,SOH)是电池管理系统的核心问题,对其精确的评估能够保障电池的安全可靠运行.然而在实际应用中,容量较难直接测得,导致SOH估算困难.为了获得准确的SOH,本文提出一种基于注意力改进双向门控循环单元(BiGRU)的锂离子电池SOH估计方法.首先提取电池充放电曲线中的电压、电流与阻抗等参数,通过自编码器(auto encoder,AE)对其降维,提取特征量并减少数据间的冗余性.其次,引入注意力机制(attention mechanism,AM)对输入变量分配权重,突出对SOH估计起到关键作用的特征量.最后,利用BiGRU学习输入变量与容量之间的映射关系,捕获容量衰减下的长期依赖性.在不同充电倍率的电池数据集上的结果表明,该方法对不同类型电池的SOH皆可以实现高精度估计,均方根误差在1.1％以下.     

Electrospinning: An emerging technology to construct polymer-based nanofibrous scaffolds for diabetic wound healing

A chronic wound in diabetic patients is a major public health concern withsocioeconomic and clinical manifestations.The underlying medical condition of diabeticpatients deteriorates the wound through physiological,metabolic,molecular,and cellularpathologies.Consequently,a wound enters a vicious pathological inflammatory cycle.Many therapeutic approaches are in practice to manage diabetic wounds hence ensuringthe regeneration process.Polymer-based biomaterials have come up with hightherapeutic promises.Many efforts have been devoted,over the years,to build aneffective wound healing material using polymers.The electrospinning technique,although not new,has turned out to be one of the most effective strategies in buildingwound healing biomaterials due to the special structural advantages of electrospunnanofibers over the other formulations.In this review,careful integration of allelectrospinning approaches has been presented which will not only give an insight intothe current updates but also be helpful in the development of new therapeutic materialconsidering pathophysiological conditions of a diabetic wound.     

Chemical Characterization and Edibility of the Oil Extracted from Citrullus colocynthis Seeds

The characteristics and composition of the crude oil extracted from Citrullus colocynthis seeds were examined. Data obtained for the iodine value, saponification number, Reichert-Meissl and others compare well with other edible oils. Thin-layer chromatography in conjunction with gas-liquid chromatography-mass spectrometry revealed over 75% degree of unsaturation major among which were linoleic, 50.6% and oleic acids, 25%. Upon storage, the oil showed relatively low peroxide values that were within the acceptable limits set for other vegetable oils. Animal experimentation trials on the oil using chicks as the experimental animals did not show any toxicity effects. Based on these results, Citrullus colocynthis oil might be of some potential use for animal feed and/or human consumption.     

QUANTITATIVE, QUALITATIVE AND TOXIGENIC EVALUATIONS OF XEROPHILIC MOLD IN TRADITIONAL EGYPTIAN SALTED FISH, MOLOUHA

Sixty samples of salted fish (Molouha) were randomly collected from Ismailia City, Egypt to evaluate the quantitative, qualitative and toxigenicity of xerophilic mold. The results revealed that 50 (83.3%) out of 60 salted fish analyzed were contaminated by xerophilic mold, while 16.7% were negative. The mean value of total xerophilic mold was 2.45 ± 0.95 log₁₀ cfu/g. Aspergillus spp. was the most predominant xerophilic mold (58.2%) in the fish followed by Penicillium spp. (32.7%). Aspergillus niger and P. verrecosum var. verrecosum were the most predominant mold strains in investigated samples. Thirty‐one (18.8%) toxigenic xerophilic mold strains out of 165 isolated xerophilic mold species found to be Sterigmatocystin and Aflatoxin B₂, G₁mycotoxin producers. Salted fish processing should be controlled by the authority in concern to solve the poor mycological quality of retail salted fish in Ismailia city. Measures must be developed to control the growth and activity of xerophilic mold in salted fish.     

Perceptual clustering for automatic hotspot detection from Ki‐67‐stained neuroendocrine tumour images

Hotspot detection plays a crucial role in grading of neuroendocrine tumours of the digestive system. Hotspots are often detected manually from Ki‐67‐stained images, a practice which is tedious, irreproducible and error prone. We report a new method to segment Ki‐67‐positive nuclei from Ki‐67‐stained slides of neuroendocrine tumours. The method combines minimal graph cuts along with the multistate difference of Gaussians to detect the individual cells from images of Ki‐67‐stained slides. It, then, automatically defines the composite function, which is used to determine hotspots in neuroendocrine tumour slide images. We combine modified particle swarm optimization with message passing clustering to mimic the thought process of the pathologist during hotspot detection in neuroendocrine tumour slide images. The proposed method was tested on 55 images of size 10 × 5 K and resulted in an accuracy of 94.60%. The developed methodology can also be part of the workflow for other diseases such as breast cancer and glioblastomas.     

CHANGE OF FAT CONTENT AND FATTY ACID COMPOSITION OF TURKISH HAZELNUTS (CORYLUS AVELLANA L.) DURING STORAGE

Hazelnuts (Corylus avellana L.) were collected from three different cultivars (Tombul, Palaz and Kal?nkara) at the harvest season of 1996. The dried nuts were stored shelled and unshelled in polyethylene bags at 21C and 60–65% relative humidity for 12 months. During storage, the total fat content increased, the palmitic and oleic acid content of the oil increased, linoleic acid, ranged from 12.41 to 10.35%. No significant differences were found for other fatty acids during storage. The effect of storage of shelled and unshelled hazelnuts on the total fat content was significant.     

THE EFFECT OF ULTRAVIOLET IRRADIATION ON SHELF-LIFE AND RIPENING OF PEACHES AND APPLES

“Loring” and “Elberta” peaches and “Golden Delicious” apples were irradiated with UV (254nm) to doses of 0.84 × 10⁴ to 40 × 10⁴ erg/mm² then stored. “Loring” were stored 10 days and “Elberta” 20 days at 12°C. “Golden Delicious” were stored 30 days at 20–25°C in a dark room. Fruit were examined and differences in percentage rot and in physical-chemical properties determined. Percentage rot decreased with increasing UV dose. Fruit were firmer, pH and soluble solids lower and acidity higher for UV-treated than for nontreated peaches; pH was lower and acidity and ascorbic acid higher in UV treated than in nontreated apples. Percentage weight loss was less for UV-treated apples. The results indicated that UV treatment not only reduced storage rots but also delayed ripening of peaches and apples.