Quantitative determination of H2O2 for detection of alanine aminotransferase using thin film electrodes.

The abnormal concentrations or absence of biomolecules (e.g., proteins) in blood can further be used in diagnosis of a particular pathology at an early stage. Current studies are intensely focusing on the analysis of interaction and detection of biomolecules via point-of-care systems (POCs), allowing miniaturized and parallelized reactions, simultaneously. Recent developments have shown that the collaboration of electrochemical sensing techniques and POCs to overcome challenging problems in health-care settings provides new approaches in diagnosis and treatment of diseases. The aim of this study was to adapt the alanine aminotransferase (ALT) enzyme to the platinum (Pt) thin film electrode system and quantitatively determine the enzyme levels via enzymatically generated H2O2 with differential pulse voltammetry (DPV). A simple potentiostat architecture with expanded sweep range utilizing dual LMP91000 devices was developed and adapted to the needs of the biosensor. In order to calibrate the system, known concentrations of H2O2 were also tested. Moreover, signals associated with the other electroactive species coming from the ALT reaction were eliminated. Resulted potential range has been achieved between +500 mV and +900 mV and the linear range was found to be 0.05 M-0.5 M for H2O2, whereas 5 UL-1 to 120 UL-1 for ALT enzyme.

Examining the effects of stroke on students' L2-grit levels in an EFL context: A case of Northern Iraq.

This article investigates the effects of stroke on students' L2-grit levels in an EFL context in Northern Iraq. A model was created to find how various components such as verbal, non-verbal, valuing, and activities that determine stroke levels affect students' grit. This study adopted the L2- Grit scale and a language domain-specific grit scale to measure the learners' L2-grit levels. Also, the Students' Stroke Scale (SSS) was used to measure the participants' stroke levels. The study's sample consisted of 199 participants from various academic levels, undergraduate, graduate, and postgraduate at several Northern Iraq universities. The results reveal a positive and statistically significant association between the score on the L2-Grit scale and the score on the Stroke scale; more specifically, as the scores on the L2-grit scale rise, so do the scores on the Stroke scale. The mean of low stroke is lower than the means of medium stroke and high stroke indicating that as people's stroke levels grow, so does their L2-grit status. The regression coefficients estimated within the framework of the regression model structured with the logit, the link function, are the same in each category of the dependent variable, satisfying the parallel curves assumption. The overall results show that positive stroke helps learners' L2-grit levels to arise and lead to a better learning process.

The relationship of emotional abuse, self-value and conflict resolution needs in secondary school students.

The most crucial period for the teenagers is the secondary school period. The affection and knowledge that lead the student to build up his or her own self individuality, develop positive relationships, and cope with possible conflicts must be given to her or him by his or her family and neighborhood. The aim of this study was to analyze the correlation among the self-respect, the need for the solution of the conflict, social anxiety, and emotional exploitation within the range of the middle school students. The aforementioned research is such a kind of descriptive study which used one of the correlational survey research models, the quantitative method. In addition to the Personal Data Collection Document, the Scales of the Need of Conflict Resolution, emotional exploitation, the Rosenberg Self-Respect Scale, and the Social Anxiety Scale for the Teenagers are used. The research universe of this study is composed of 10.196 middle school students studying in the 6th, 7th, and the 8th year, at the public schools of the Ministry of Education of the TRNC. The sample group of the research is constituted by 530 volunteer middle school students from Famagusta, Guzelyurt, Lefke, Nicosia, and Kyrenia, respectively. The AMOS 2.1 and the SPSS 25 are used to resolve the data collected. The study that carried out through the structural equality method verifies that there is an agent role of the Need for the Conflict Resolution in between the self-respect and emotional exploitation. However, there cannot be verified any relation in between the self-respect and the social anxiety within the agent role of the Need for the Conflict Resolution. There has been verified meaningful and positive correlations among through the marks of the students taken from the NCR and the SAST, the NCR and the EES, the NCR and the RSRS, the SAST and the RSRS, the SAST and the EES, and the EES and the RSRS.

Low-Cost High-Resolution Potentiostat for Electrochemical Detection of Nucleic Acids and Biomolecular Interactions.

A handheld USB-powered instrument developed for the electrochemical detection of nucleic acids and biomolecular interactions is presented. The proposed instrument is capable of scanning ± 2.25 V while measuring currents up to ±10 mA, with a minimum current resolution of 6.87 pA. Therefore, it is suitable for nucleic acid sensors, which have high background currents. A low-cost microcontroller with an on-chip 16-bit analog-to-digital converter, 12-bit digital-to-analog converter, and a built-in USB controller were used to miniaturize the system. The offset voltages and gain errors of the analog peripherals were calibrated to obtain a superior performance. Thus, a similar performance to those of the market-leader potentiostats was achieved, but at a fraction of their cost and size. The performance of the application of this proposed architecture was tested successfully and was found to be similar to a leading commercial device through a clinical application in the aspects of the detection of nucleic acids, such as calf thymus ssDNA and dsDNA, and their interactions with a protein (BSA) by using single-use graphite electrodes in combination with the differential pulse voltammetry technique.

Predicting invasive phenotype with CDH1, CDH13, CD44, and TIMP3 gene expression in primary breast cancer.

We aimed to determine changes in the expression of the genes CDH1, CDH13, CD44, and TIMP3 to look for any relationship between them, HER2 and ESR1 expression at the RNA level, and the histopathological properties of tumors. We also analyzed the expression properties of double-negative (estrogen receptor [ER] and human epidermal growth factor receptor [HER2] both negative) breast tumors. Expression status was studied in fresh tissue at the mRNA level with quantitative PCR using hydrolysis probes. Sixty-two cancer patients and four normal controls were included in the study. When the tumor group was analyzed as a whole, the correlations of ESR1 with CDH1, CDH13, and TIMP3 were P < 0.05, P < 0.005, and P < 0.005, respectively. In ER-positive tumors, CDH1 and CDH13 were correlated directly (P < 0.005) when HER2 was correlated with CDH1, CDH13, and TIMP3 indirectly (P < 0.005, P < 0.005, and P < 0.05, respectively). CDH1 and CD44 had a strong indirect correlation (P < 0.005) in ER-negative tumors. There were significant differences in the expression levels of the CDH13, TIMP3, and CD44 genes (P < 0.005, P < 0.005, and P < 0.05, respectively) between the ER-positive and -negative groups. All four genes were found to be correlated with invasive properties in both ER-positive and -negative tumors. In double-negative tumor samples, only CD44 had a significant and strong correlation with stage, lymph node involvement, and metastasis (P < 0.05, P < 0.005, and P < 0.05, respectively). As a conclusion, a decrease in CDH1, CDH13, and TIMP3 expression levels with an increase in CD44 can be used as an indicator for invasion in both ER-positive and -negative breast tumors. In double-negative tumor tissues, CD44 can be considered a marker for aggressive properties.