Enzymatic sensing with laccase-functionalized textile organic biosensors

Herein we present a textile wearable electrochemical transistor by functionalizing a single cotton yarn with semiconducting polymer. The organic electrochemical transistor (OECT), which is low cost and completely integrated e-textile, is decorated by adsorption of the fungal laccase POXA1b, and is used as biosensor for the direct detection of Tyrosine (L-Tyr) without the use of electron mediators. The detection of Tyr in real-case scenario such as human physiological fluids would own a paramount importance in noninvasive analysis of the patient's condition, monitoring and preventing several pathologies. To assess the reaction progression, the redox process is studied by UV–visible absorption with test reference molecule of 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS): the results confirmed that the oxidation reaction is driven by the presence of laccase enzyme and direct electron transfer occurred. The modulation of the signal response and the kinetic of the signal is used to detect Tyr molecule in aqueous solution and the role of the enzyme adsorption on the textile is analyzed. A kinetic analysis of the characteristic modulation times of the sensing curves, confirm the sensing properties of the textile device. The textile-based biosensor is demonstrated to monitor human health biomarkers through wearable applications in a non-invasive way, finding potential application in sport, healthcare and working safety.     

In silico design: Extended molecular dynamic simulations of a new series of dually acting inhibitors against EGFR and HER2

Based on the hit structures that have been identified in our previous studies against EGFR and HER2, new potential inhibitors that share the same scaffold of the hit structures are designed and screened in silico. Insights into understanding the potential inhibitory effect of the new inhibitors against both EGFR and HER2 receptors is obtained using extended molecular dynamics (MD) simulations and different scoring techniques. The binding mechanisms and dynamics are detailed with respect to two approved inhibitors against EGFR (lapatinib) and HER2 (SYR127063). The best scoring inhibitor (T9) is chosen for additional in silico investigation against both the wild-type and T790M mutant strain of EGFR and the wild-type HER2. The results reveal that certain substitution patterns increase the stability and assure stronger binding and higher H-bond occupancy of the conserved water molecule that is commonly observed with kinase crystal structures. Furthermore, the new inhibitor (T9) forms stable interactions with the mutant strain as a direct consequence of the enhanced ability to form additional hydrogen bonding interactions with binding site residues.     

Effect of gamma-irradiation on flavour 5′-nucleotides,tyrosine, and phenylalanine in mushrooms (Agaricus bisporus)

The impact of gamma-irradiation on 5′-nucleotides and on the free amino acids tyrosine and phenylalanine in fresh mushrooms was studied. After irradiation the samples were freeze-dried to avoid enzyme induced chemical changes. Three 5′-nucleotides could be detected using HPLC–UV and LC–ESI-MS: adenosine 5′-monophosphate (AMP), guanosine 5′-monophosphate (GMP) and guanosine 5′-diphosphate (GDP). Irradiation significantly reduced (p = 0.05) the GDP concentration (22%). AMP showed a marked reduction (46%) only at 5 kGy. GMP, tyrosine, and phenylalanine were not affected by gamma-irradiation.     

Determination of aromatic amino acid content in cooked meat by derivative spectrophotometry: Implications for nutritional quality of meat

The technique of second derivative spectrophotometry was used to determine the level and the heat stability of the three aromatic amino acids (tryptophan, tyrosine and phenylalanine) in bovine meat (M. Longissimus thoraci). This paper presents a method which measures the second derivative absorbance values at a wavelength specifically assigned to each aromatic amino acid with corrections for the interference from other amino acids at the same wavelength. Three cooking temperatures were tested in this study (60, 100 and 140 °C). Due to important cooking losses, results differ slightly according to the method of calculation (level expressed by gram of wet meat or by gram of proteins). Whatever the calculation method, heating at 60 °C had little effect on aromatic acid levels while higher temperatures had a dramatic effect on aromatic amino acids stability. The stability of the three aromatic amino acids during cooking decreased in the order tryptophan > phenylalanine > tyrosine.     

火花放电产生的离子对酪氨酸溶液损伤作用的初步研究

利用气体火花放电产生离子，其中的正离子在阴极位和的加速下被“注入”到酪氨酸溶液中，研究了Ｔｙｒ经过这种方式产生的离子作用后紫外及红外吸收光谱性质的变化。利用高效液相色谱（ＨＰＬＣ）对空气放电处理过的Ｔｙｒ进行了分析。实验结果表明，这种火花放一的低能离子对溶液样品造成多种形式的损伤，形成多种损伤产物，而损伤情况依赖于放电产生的离子的性质 。     

Correlations between some nitrogen fractions,lysine, histidine,tyrosine, and ornithine contents during the germination of peas,beans, and lentils

The effect of different germination conditions, namely, germination time and total presence or absence of light, on the content of the various nitrogen fractions, three essential protein amino acids (Lys, His, and Tyr) and one non-protein amino acid (Orn), was studied in peas, beans, and lentils. The influence of light during germination on the parameters considered varied according to the legume but on the whole was less important than the influence of germination time in quantitative terms. In all three legumes, prolonging the germination time yielded flours that contained more non-protein nitrogen (NPN) and Orn and less protein nitrogen (PN) and Lys, while the changes in the His and Tyr contents varied with legume type. In addition, changes in the Lys, Tyr, and Orn contents correlated with the changes in the NPN and PN levels in the germinated legumes.     

Organic solar cell based on photosystem I pigment-protein complex,fabrication and optimization

The trends of using biological materials in electronic devices have made great developments in the last few years. Furthermore, the appealed cost features of organic semiconductors represent a bright low-cost, environment compatible, and efficient future for bio & nanotechnologies, especially Bio-organic solar cells which may consider as a noteworthy option for photovoltaic applications. Here, we report a novel single junction organic solar cell based on photosystem I pigment-protein complex. The complex which operated either as photosensitizer and charge generator compound, surprisingly. Photosystem I complexes were extracted from young spinach leaves and used as the active layer of the intended solid-state solar cell device, subsequently. After the characterization of the final cell, our photovoltaic system showed the current density of 3470 μA cm⁻² which realizes as a notable approach in between photosystem- I based energy conversion systems.     

酪氨酸羟化酶阳性神经元在扬子鳄、家鸡及大鼠脑桥的分布比较

目的: 观察并比较扬子鳄、家鸡及大鼠脑桥酪氨酸羟化酶(Tyrosine hydroxylase,TH)阳性神经元的形态和分布,为生物进化及扬子鳄种群遗传保护与神经系统疾病防治提供比较解剖学资料。方法: 扬子鳄6只、家鸡和SD大鼠各15只。三种动物再各分三组进行分次实验,每次扬子鳄2只,家鸡和SD大鼠各5只,同一时间内电击处死后,取脑桥组织,采用免疫组织化学方法结合黑马病理图像分析系统检测三种动物脑桥TH阳性神经元的分布特征。结果: 三种动物脑桥均见TH阳性神经元成团或散在分布,均可见椭圆形、圆形、梭形、多角形等,但三种动物间脑桥不同形态的细胞数量大多存在差异(P<0.01);三种动物脑桥TH阳性神经元均以中、小细胞为主,大细胞相对较少;与扬子鳄相比,家鸡及大鼠脑桥同节段TH阳性神经元数均明显增加,灰度值降低,均具有统计学差异(P＜0.01);与家鸡相比,大鼠脑桥TH阳性神经元数明显增加,灰度值降低,均具有统计学差异(P＜0.01)。结论: 扬子鳄、家鸡及大鼠脑桥TH神经元数量依次增多,细胞平均灰度值依次降低,不同形态的细胞比例存在一定差异,提示脑桥TH神经元的分布差异可能与不同物种脑桥执行其相关神经系统生理功能的不同有关。