A Highly Selective Colorimetric Sensor for Cysteine in Water Solution and Bovine Serum Albumin

A simple colorimetric sensor, 2-bromonaphthalene-1,4-dione, has been developed for the Cysteine detection. The sensor showed its best performance in a mixture of ethanol and HEPES (5 : 5, v/v) solution at pH of 7.0. The results of UV-vis and fluorescence indicated that 2-bromonaphthalene-1,4-dione was selective and sensitive for Cysteine detection without the interference of other amino acids (Cysteine, Alanine, Arginine, Aspartinie, Glutamine, Glycine, Histidine, Isoleucine, Leucine, Lysine, Methionine, Proline, Serine, Threonine, Phenylalanine, Valine, Tryptophan, and Hydroxyproline). 2-Bromonaphthalene-1,4-dione also showed binding ability for Cysteine in bovine serum albumin and could be used as a potential colorimetric sensor among eighteen kinds of natural amino acids. Importantly, the recognition of CySH could be observed by naked eye

Over-expression of eukaryotic translation initiation factor 4 gamma 1 correlates with tumor progression and poor prognosis in nasopharyngeal carcinoma

<p>Abstract</p> <p>Background</p> <p>The aim of the present study was to analyze the expression of eukaryotic translation initiation factor 4 gamma 1 (<it>EIF4G1</it>) in nasopharyngeal carcinoma (NPC) and its correlation with clinicopathologic features, including patients' survival time.</p> <p>Methods</p> <p>Using real-time PCR, we detected the expression of <it>EIF4G1 </it>in normal nasopharyngeal tissues, immortalized nasopharyngeal epithelial cell lines NP69, NPC tissues and cell lines. <it>EIF4G1 </it>protein expression in NPC tissues was examined using immunohistochemistry. Survival analysis was performed using Kaplan-Meier method. The effect of <it>EIF4G1 </it>on cell invasion and tumorigenesis were investigated.</p> <p>Results</p> <p>The expression levels of <it>EIF4G1 </it>mRNA were significantly greater in NPC tissues and cell lines than those in the normal nasopharyngeal tissues and NP69 cells (<it>P </it>< 0.001). Immunohistochemical analysis revealed that the expression of <it>EIF4G1 </it>protein was higher in NPC tissues than that in the nasopharyngeal tissues (<it>P </it>< 0.001). In addition, the levels of <it>EIF4G1 </it>protein in tumors were positively correlated with tumor T classification (<it>P </it>= 0.039), lymph node involvement (N classification, <it>P </it>= 0.008), and the clinical stages (<it>P </it>= 0.003) of NPC patients. Patients with higher <it>EIF4G</it>1 expression had shorter overall survival time (<it>P </it>= 0.019). Multivariate analysis showed that <it>EIF4G1 </it>expression was an independent prognostic indicator for the overall survival of NPC patients. Using shRNA to knock down the expression of <it>EIF4G1 </it>not only markedly inhibited cell cycle progression, proliferation, migration, invasion, and colony formation, but also dramatically suppressed <it>in vivo </it>xenograft tumor growth.</p> <p>Conclusion</p> <p>Our data suggest that <it>EIF4G1 </it>can serve as a biomarker for the prognosis of NPC patients.</p

Postmortem biochemical and textural changes in the Patinopecten yessoensis adductor muscle (PYAM) during iced storage

Postmortem characteristics of Patinopecten yessoensis adductor muscle (PYAM) were evaluated by biochemical, chemical and textural changes during iced storage for 14 days. Triphosphate (ATP) and its breakdown products, K-value, total volatile basic nitrogen (TVB-N), pH, water-holding capacity (WHC), color, texture, protein degradation and cathepsin activities were monitored. K-value increased linearly from 5.9 ± 0.9% at day 0 to 28.1 ± 2.4% at day 2 and 70.2 ± 1.8% at day 12. Spoilage indicator TVB-N (mg/100 g) increased from 10.0 ± 0.6 to 34.6 ± 3.1 at day 12. Textural parameters (e.g., hardness, chewiness, springiness, adhesiveness, and shear force) followed a declining trend over the storage. The WHC decreased from 85.1 ± 3.1% at day 0 to 70.5 ± 1.8% at day 12. SDS-PAGE result indicated that proteolysis occurred in actin and myosin heavy chain (MHC) at day 14. Both cathepsin B and L increased throughout the iced storage, peaking at 1.47-fold and 1.08-fold, respectively, suggesting that cathepsin B and L played important roles in the deterioration of PYAM quality. The overall results indicated that PYAM was suitable to be consumed raw within the first 2 days, and to be processed in no more than 11 days

Material Removal Mechanism and Force Model of Nanofluid Minimum Quantity Lubrication Grinding

Numerous researchers have developed theoretical and experimental approaches to force prediction in surface grinding under dry conditions. Nevertheless, the combined effect of material removal and plastic stacking on grinding force model has not been investigated. In addition, predominant lubricating conditions, such as flood, minimum quantity lubrication (MQL), and nanofluid minimum quantity lubrication (NMQL), have not been considered in existing force models. In this study, material removal mechanism under different lubricating conditions was researched. An improved theoretical force model that considers material removal and plastic stacking mechanisms was presented. Grain states, including cutting and ploughing, are determined by cutting efficiency (β). The influence of lubricating conditions was also considered in the proposed force model. Simulation was performed to obtain the cutting depth (a g) of each “dynamic active grain.” Parameter β was introduced to represent the plastic stacking rate and determine the force algorithms of each grain. The aggregate force was derived through the synthesis of each single-grain force. Finally, pilot experiments were conducted to test the theoretical model. Findings show that the model’s predictions were consistent with the experimental results, with average errors of 4.19% and 4.31% for the normal and tangential force components, respectively

Double Properties of Novel Acylhydrazone Nanomaterials Based on a Conjugated System: Anion Binding Ability and Antibacterial Activity

A series of new compounds (1–12) containing 1,5-diaza-fluorenone, 1,10-phenanthroline-5,6-dione, ferrocene-1,1ʹ-dione, anthracene-9-carbaldehyde have been synthesized and optimized. The nanomaterials were also developed successfully. The binding properties were evaluated for biologically important anions (F−, Cl−, Br−, I−, AcO−, and H2PO4−) by theoretical investigation, UV-vis, and fluorescence experiments, and compound 6 displayed the strongest binding ability for AcO− ion among the synthesized compounds. Theoretical investigation analysis revealed that the intramolecular hydrogen bond existed in the structure of compound 6 and the roles of molecular frontier orbitals in molecular interplay. In addition, compound 6 showed wide antibacterial activity for colon bacillus, typhoid bacillus, and Pseudomonas aeruginosa, and inferior activity for hay bacillus and Staphylococcus aureus. This series of acylhydrazone nanomaterials showed double properties, anion binding ability, and antibacterial activity

Comparison of Effects from Ultrasound Thawing, Vacuum Thawing and Microwave Thawing on the Quality Properties and Oxidation of Porcine Longissimus Lumborum

The effects of vacuum thawing (VT), ultrasound thawing (UT) and microwave thawing (MT) on the quality, protein and lipid oxidation, internal temperature distribution and microstructure of porcine longissimus lumborum were compared. The results showed that a significant decrease (p &lt; 0.05) in quality compared with those of fresh meat (FM) occurred for all of the thawing samples, especially for the MT samples. Changes in quality of the VT and UT samples were less significant than those of the MT samples. The increases in carbonyl content and TBARS value indicated that proteins and lipids in the thawing samples were oxidized. The decreases in uniform degrees of internal temperature distributions of muscles from the thawing samples were analysed by infrared thermography. Scanning electron microscopy images showed that the myofibril arrangements of thawing samples were looser than those of the FM samples with compact and ordered structure, which was proven by the obvious increase in the myofibril gap value of the thawing samples

Mechanisms of Change in Emulsifying Capacity Induced by Protein Denaturation and Aggregation in Quick-Frozen Pork Patties with Different Fat Levels and Freeze&ndash;Thaw Cycles

Herein, we discuss changes in the emulsifying properties of myofibrillar protein (MP) because of protein denaturation and aggregation from quick-frozen pork patties with multiple fat levels and freeze&ndash;thaw (F&ndash;T) cycles. Protein denaturation and aggregation were confirmed by the significantly increased surface hydrophobicity, turbidity, and particle size, as well as the significantly decreased solubility and absolute zeta potential, of MPs with increases in fat levels and F&ndash;T cycles (p &lt; 0.05). After multiple F&ndash;T cycles, the emulsifying activity and emulsion stability indices of all samples were significantly reduced (p &lt; 0.05). The emulsion droplets of MP increased in size, and their distributions were dense and irregular. The results demonstrated that protein denaturation and aggregation due to multiple F&ndash;T cycles and fat levels changed the distribution of surface chemical groups and particle sizes of protein, thus affecting the emulsifying properties

Postmortem biochemical and textural changes in the Patinopecten yessoensis adductor muscle (PYAM) during iced storage

Postmortem characteristics of Patinopecten yessoensis adductor muscle (PYAM) were evaluated by biochemical, chemical and textural changes during iced storage for 14 days. Triphosphate (ATP) and its breakdown products, K-value, total volatile basic nitrogen (TVB-N), pH, water-holding capacity (WHC), color, texture, protein degradation and cathepsin activities were monitored. K-value increased linearly from 5.9 ± 0.9% at day 0 to 28.1 ± 2.4% at day 2 and 70.2 ± 1.8% at day 12. Spoilage indicator TVB-N (mg/100 g) increased from 10.0 ± 0.6 to 34.6 ± 3.1 at day 12. Textural parameters (e.g., hardness, chewiness, springiness, adhesiveness, and shear force) followed a declining trend over the storage. The WHC decreased from 85.1 ± 3.1% at day 0 to 70.5 ± 1.8% at day 12. SDS-PAGE result indicated that proteolysis occurred in actin and myosin heavy chain (MHC) at day 14. Both cathepsin B and L increased throughout the iced storage, peaking at 1.47-fold and 1.08-fold, respectively, suggesting that cathepsin B and L played important roles in the deterioration of PYAM quality. The overall results indicated that PYAM was suitable to be consumed raw within the first 2 days, and to be processed in no more than 11 days.This article is published by Taylor & Francis as Xiong, Xin, Baoyu He, Di Jiang, Xiufang Dong, Aeneas Koosis, Chenxu Yu, and Hang Qi. "Postmortem biochemical and textural changes in the Patinopecten yessoensis adductor muscle (PYAM) during iced storage." International Journal of Food Properties 22, no. 1 (2019): 1024-1034. DOI: 10.1080/10942912.2019.1625367. Posted with permission.</p