Development of optical and electrochemical immunodevices for dengue virus detection.

Dengue virus (DENV) is the most prevalent global arbovirus, exhibiting a high worldwide incidence with intensified severity of symptoms and alarming mortality rates. Faced with the limitations of diagnostic methods, an optical and electrochemical biosystem was developed for the detection of DENV genotypes 1 and 2, using cysteine (Cys), cadmium telluride (CdTe) quantum dots, and anti-DENV antibodies. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), surface plasmon resonance (SPR), atomic force microscopy (AFM), and Fourier transform infrared spectroscopy (FTIR) were employed to characterize the immunosensor. The AFM and SPR results demonstrated discernible topographic and angular changes confirming the biomolecular recognition. Different concentrations of DENV-1 and DENV-2 were evaluated (0.05 × 106 to 2.0 × 106 PFU mL-1), resulting in a maximum anodic shift (ΔI%) of 263.67% ± 12.54 for DENV-1 and 63.36% ± 3.68 for DENV-2. The detection strategies exhibited a linear response to the increase in viral concentration. Excellent linear correlations, with R2 values of 0.95391 for DENV-1 and 0.97773 for DENV-2, were obtained across a broad concentration range. Data analysis demonstrated high reproducibility, displaying relative standard deviation values of 3.42% and 3.62% for Cys-CdTe-antibodyDENV-1-BSA and Cys-CdTe-antibodyDENV-2-BSA systems. The detection limits were 0.34 × 106 PFU mL-1 and 0.02 × 106 PFU mL-1, while the quantification limits were set at 1.49 × 106 PFU mL-1 and 0.06 × 106 PFU mL-1 for DENV-1 and DENV-2, respectively. Therefore, the biosensing apparatus demonstrates analytical effectiveness in viral screening and can be considered an innovative solution for early dengue diagnosis, contributing to global public health.

Soil surface roughness impacts the risk arising from a hypothetical urban radiological dispersive device activation.

This study considers a deliberate hypothetical release of radioactive material over an inhabited urban zone. The event is initiated by the activation of a radiological dispersion device. The main threat is the deposition of radioactive material onto the soil's surface. The radiation represents the threat-defining risks, which depend on the main variables, i.e. soil surface roughness, sex, age of the exposed individuals and the moment of the release (day or nighttime). This study aims to evaluate the effect of soil surface roughness on the radiological risk. The simulation was performed by an analytical method using the HotSpot Health Physics code within the first 100 h. The results found relevant elements that allow for differentiating consequences as a function of the time of release (whether daytime or nighttime), thus allowing decision-makers to be supported with a little more detail about the situation, although in a critical initial phase.

Body composition, lipid profile and clinical parameters are predictors of prognosis in patients with heart failure: Two-year follow-up.

BACKGROUND: Heart failure (HF) is a complex syndrome that leads to changes in body composition and eventually results in unfavorable outcomes. AIM: This study aimed to evaluate body composition, lipid profiles and clinical parameters of patients with HF, and their associations with both survival and unfavorable clinical outcomes. METHODS: This prospective cohort study included 94 adults and older people with HF. Body composition was assessed by bioelectrical impedance analysis (BIA). Anthropometric variables and lipid profile were also evaluated. Electronic medical records were checked to collect information on clinical outcomes (mortality and hospitalization), considering a follow-up period of 24 months. Survival was calculated using the Kaplan-Meier estimate, and the curves compared using Log-Rank. The death risk rate (Hazard Ratio, HR) was calculated using Cox's univariate models. RESULTS: Mean age was 55.1 (13.9) years and there was a higher frequency of males. There was a predominance of HF with reduced ejection fraction, and ischemic etiology. Patients with New York Heart Association (NYHA) functional classification I/II had a better overall survival rate at 24 months than those with NYHA III/IV (univariate HR 4.93 (1.76-13.82); p = 0.001). Greater survival rates were found in patients without chronic kidney disease (CKD) (univariate HR 2.93 (1.59-5.39); p = 0.01). In the multivariate analyses, both dyslipidemia (adjusted HR 3.84 (1.22-12.00); p = 0.021) and increased fat mass index (FMI) were associated with overall survival rate (adjusted HR 3.59 (1, 10-11.74); p = 0.034). CONCLUSION: The severity of HF symptoms and the presence of chronic kidney disease are associated with higher mortality. Increased fat mass index and dyslipidemia are predictors of favorable outcomes in this population.

Impedimetric gene assay for BCR/ABL transcripts in plasmids of patients with chronic myeloid leukemia.

A label-free impedimetric biosensor was developed for determination of BCR/ABL transcripts. Specific DNA primers were covalently immobilized on a gold electrode modified with carboxylated multiwalled carbon nanotubes (cMWCNTs) and zinc oxide nanoparticles (ZnO-NPs). Aggregation of the ZnO-NPs is prevented by the introduction of an amino-modified silica coating, which also allows a subsequent covalent linkage to cMWCNTs. The impedimetric biosensor was typically operated at a working voltage of +10 mV vs. Ag/AgCl, in a frequency range from 100 mHz to 100 kHz. Studies on the surface morphology and electrochemical properties of the electrode demonstrated improved bioactivity. Amperometric currents and impedimetric parameters, such as charge transfer resistance, varied significantly throughout the construction of the biosensor. The hybridization process was also evidenced by changes in the topography of the surface after exposure to samples containing BCR/ABL. The gene sensor has a linear concentration range for the target gene of 6.94 aM to 694 fM with a limit of detection as low as 0.039 aM. Also, the biosensor is selective and reproducible with a standard deviation of 4.1%. Three replicates for each experimental condition were used. Hence, it is perceived to be a viable tool for early-stage diagnosis of the BCR/ABL fusion gene and monitoring of major molecular remission in clinical samples. Graphical abstract Schematic of a highly sensitive hybridization assay for the BCR/ABL fusion gene. It is based on ZnO nanoparticle functionalized with 3-(aminopropyl)triethoxysilane.