Novel melanin-derived stationary phase for immobilized metal ion affinity chromatography in recombinant His-tagged protein purification.

The matrix of the stationary phase is a crucial element in affinity chromatography for protein purification. Various materials, including polymer or magnetic materials, have been employed as the matrix in the purification of His-tagged protein. Here, for the first time, we utilized a combination of melanin and alginate, both natural polymer materials, to synthesize Ni-melanin/alginate (Ni-M/A) beads for His-tagged protein purification. We investigated the binding of His-tagged Mpro on the Ni-M/A beads, referred to as Ni-M/A-Mpro, and assessed the elution efficiency of Mpro from the beads. Our examination involved FTIR, EDS, XRD, SDS-PAGE, and Western blotting methods. FTIR spectra revealed notable changes in the stretching patterns and intensities of hydroxyl, amine, carbonyl, imine and amide chemical groups, when Mpro protein was present in the Ni-M/A sample. XRD spectra demonstrated the occurrence of two Nickel peaks at 35-40 deg and 40-45 deg in Ni-M/A, but only one nickel peak at 35-40 deg in Ni-M/A-Mpro, indicating the binding of Mpro on the Nickel ions. EDS analysis reported a decrease in the concentration of Nickel on the surface of Ni-M/A from 16% to 7% when Mpro protein was loaded into the stationary phase. Importantly, our data indicated that the purity of the His-tagged protein Mpro after purification reached 97% after just one-step purification using the Ni-M/A stationary phase. Moreover, the binding capacity of Ni-M/A for Mpro was approximately 5.2 mg/g with recovery efficiency of 40%. Our results suggested Ni-M/A as a highly potential solid phase for affinity chromatography in the purification of His-tagged protein.

Spatio-temporal characterization of drought variability in data-scarce regions using global precipitation data: a case study in Cauto river basin, Cuba.

Drought is considered the most severe water-related disaster in the Cauto river basin, which is the longest river and the main agricultural producer in Cuba. Better understanding of drought characteristics is crucial to drought management. Given the sparsity of ground-based precipitation observations in the Cauto, this study aims at using gridded global precipitation to analyze the spatio-temporal variations of drought in this river basin. Firstly, the monthly Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) was calibrated with the gauged precipitation using the Thiessen polygon-based method and linear least squares regression equations. Then, the gridded standardized precipitation index (SPI) with time scales of 3, 6, 9 months and drought characteristics, namely, drought frequency, duration and intensity were calculated using the calibrated CHIRPS. Finally, the spatio-temporal analysis was performed to investigate the variations of drought in the Cauto river basin in time and space. The obtained results show that the calibrated CHIRPS is highly consistent with the gauged observations and is capable of determining the magnitude, time, and spatial extent of drought events in the Cauto river basin. The trend analysis by the Mann-Kendall test reveals that although the trend is not statistically significant, the SPI tends to decrease with time in the dry season, which indicates the more severe drought. The spatial analysis indicates that the lower altitude area of the Cauto river basin is suffered from longer drought duration and higher drought intensity than the upper one. This study expresses the importance of open global precipitation data sources in monitoring and quantifying drought characteristics in data-scarce regions.

BM-BronchoLC - A rich bronchoscopy dataset for anatomical landmarks and lung cancer lesion recognition.

Flexible bronchoscopy has revolutionized respiratory disease diagnosis. It offers direct visualization and detection of airway abnormalities, including lung cancer lesions. Accurate identification of airway lesions during flexible bronchoscopy plays an important role in the lung cancer diagnosis. The application of artificial intelligence (AI) aims to support physicians in recognizing anatomical landmarks and lung cancer lesions within bronchoscopic imagery. This work described the development of BM-BronchoLC, a rich bronchoscopy dataset encompassing 106 lung cancer and 102 non-lung cancer patients. The dataset incorporates detailed localization and categorical annotations for both anatomical landmarks and lesions, meticulously conducted by senior doctors at Bach Mai Hospital, Vietnam. To assess the dataset's quality, we evaluate two prevalent AI backbone models, namely UNet++ and ESFPNet, on the image segmentation and classification tasks with single-task and multi-task learning paradigms. We present BM-BronchoLC as a reference dataset in developing AI models to assist diagnostic accuracy for anatomical landmarks and lung cancer lesions in bronchoscopy data.

Sequencing VP4, VP7, NSP1, NSP4 genes of human Rotavirus strain G1P8

Rotavirus is the main cause of acute viral gastroenteritis in children under 5 years old. The study is to sequence nucleotides and amino acids of VP4, VP7, NSP1, and NSP4 genes of 5 passages of human rotavirus strain G1P8. The number of nucleotide mutations of VP4, VP7, NSP4 genes occuring among the passages were 3, 1, and 3, respectively. All these mutations resulted in changes in amino acid composition. No mutation was found in NSP1 gene.

Fulfilment of the RT - PCR quantitative and application of the quantitation of the CK 20 gen in the peripheric blood of the colon cancer

The authors carried out of the study on ARN message extrait from the peripheric blood of the 20 patients diagnosed to have colon cancer and 13 control healthy persons by RT - PCR quantitative with marker CK 20. The obtained results are as follows: The technique have been fulfilled; The CK 20 in the patients and the healthy person is not significant different

The application of the PCR technique to find the DYZ gene for the Y chromosome determination

On 40 subjects of unspecified gender, PCR technique application for identifying DYZ1 gen to determine Y chromosome was performed in 38 subjects (95%). The results were conformed with PCR to identify TDF and the caryotype of the control group using PCR for detecting DYZ gen in determining Y chromosome. The accuracy reached 100% with no pseudonegative or pseudopositive results. The rest 5% (2 subjects) had not Y chromosome definitely. A case of TDF on X chromosome was detected affirmatively, as a first case in Vietnam.

The identification of new viral encephalitis that was isolated from cerebrospinal fluids of acute encephalitis syndrome patients by electron microscopy

The application of electron microscopy to the rapid diagnosis of viral infection is an important and integral part of diagnostic procedures. Negative staining with a solution of uranyl acetate, which is an electron-dense salt used to stain virus particles, fills the interstices of the virus surface giving the resulting electron micrograph. With ultrathin section was given that new viral encephalitis from cerebrospinal fluids of acute encephalitis syndrome patients a spherical, RNA virus, have enveloped virions about 50-60 min diameter. This virus was sensitivity with C6/36 clone of Aedes albopictus as well as many arboviruses.