A MAGNETIC BEAD-BASED FLUORESCENT SUBSTRATE FOR SENSITIVE ASSAY OF SARS-CoV-2 3C-LIKE PROTEASE ACTIVITY.

The 3C-like protease (3CLpro) of SARS-CoV-2 is a crucial target for antiviral drugs due to its essential role in viral polyprotein processing. In this study, we designed and produced a modular fluorescent recombinant substrate (6×His-ECFP-AVLQSGFRK-EYFP), which was then immobilized on Ni-NTA magnetic beads (Ni-NTA-6×His-ECFP-AVLQSGFRK-EYFP) for the assay of 3CLpro activity. Upon cleavage at the specific AVLQ↓SG motif, the EYFP fragment was released into the supernatant and quantified via fluorescence measurement (Ex/Em = 480/528 nm).

Key RNA elements influencing DCL1 cleavage in plant microRNA biogenesis.

DICER-LIKE 1 (DCL1), a plant-specific RNase III enzyme, is fundamental to post-transcriptional gene regulation mediated by microRNAs (miRNAs). DCL1 processes precursor miRNAs into mature miRNAs, typically 20-22 nucleotides long. Despite its crucial role, the RNA elements that guide DCL1's cleavage site selection have remained largely uncharacterized.

Dynamic shifts in isomiR profiles during parasite maturation of .

We investigated the isomiR profiles of the parasitic worm across three developmental stages: newly excysted juveniles (NEJ), juveniles (JUV), and adults. Our analysis revealed a distinct shift in isomiR distribution during maturation, with NEJs exhibiting a higher abundance and diversity of isomiRs compared to later stages. Notably, isomiRs were often the dominant miRNA form in NEJs, whereas a transition to canonical miRNAs occurred as the parasite matured.

A Call to Action for Anticoagulation Stewardship to Address Suboptimal Thromboprophylaxis Practices for at-Risk Non-Orthopedic Surgical Patients in Vietnam: An Explanatory Sequential Mixed-Methods Study.

Purpose: This study aimed to investigate the current practices of VTE prophylaxis in patients undergoing abdominal-pelvic surgery (PAS) and to identify the factors that influence surgeons' practice of VTE prophylaxis.

Patients And Methods: This two-phase explanatory sequential mixed-method study used chart audits followed by semi-structured interviews based on the theoretical domain framework (TDF). During Phase I, quantitative data from 240 medical records of patients with PAS in April 2023 were audited to measure adherence rates to the standard thromboprophylaxis guidelines.

Colorectal Neoplasia in Vietnamese Patients Under 50 Years of Age: A Cross-Sectional Study.

Background/aims: Few studies have examined the colonoscopic findings of Asian individuals under 50 years of age, with some focusing on specific age cohorts. The present study examined the prevalence, endoscopic characteristics, and histology findings of colorectal neoplasia in Vietnamese patients under 50 years of age and compared these results across age groups.

Methods: A retrospective cross-sectional study was conducted at the University Medical Center, Ho Chi Minh City, Vietnam.

Active remote focus stabilization in oblique plane microscopy.

Light-sheet fluorescence microscopy (LSFM) has demonstrated great potential in the life sciences owing to its efficient volumetric imaging capabilities. For long-term imaging, the light-sheet typically needs to be stabilized to the detection focal plane for the best imaging results. Current light-sheet stabilization methods rely on fluorescence emission from the sample, which may interrupt scientific imaging and add to sample photobleaching.

Active Remote Focus Stabilization in Oblique Plane Microscopy.

Light-sheet fluorescence microscopy (LSFM) has demonstrated great potential in the life sciences owing to its efficient volumetric imaging capabilities. For long term imaging, the light-sheet typically needs to be stabilized to the detection focal plane for the best imaging results. Current light-sheet stabilization methods rely on fluorescence emission from the sample, which may interrupt the scientific imaging and add to sample photobleaching.

Two-photon autofluorescence lifetime assay of rabbit photoreceptors and retinal pigment epithelium during light-dark visual cycles in rabbit retina.

Two-photon excited fluorescence (TPEF) is a powerful technique that enables the examination of intrinsic retinal fluorophores involved in cellular metabolism and the visual cycle. Although previous intensity-based TPEF studies in non-human primates have successfully imaged several classes of retinal cells and elucidated aspects of both rod and cone photoreceptor function, fluorescence lifetime imaging (FLIM) of the retinal cells under light-dark visual cycle has yet to be fully exploited. Here we demonstrate a FLIM assay of photoreceptors and retinal pigment epithelium (RPE) that reveals key insights into retinal physiology and adaptation.

A non-FRET DNA reporter that changes fluorescence colour upon nuclease digestion.

Fluorescence resonance energy transfer (FRET) reporters are commonly used in the final stages of nucleic acid amplification tests to indicate the presence of nucleic acid targets, where fluorescence is restored by nucleases that cleave the FRET reporters. However, the need for dual labelling and purification during manufacturing contributes to the high cost of FRET reporters. Here we demonstrate a low-cost silver nanocluster reporter that does not rely on FRET as the on/off switching mechanism, but rather on a cluster transformation process that leads to fluorescence color change upon nuclease digestion.

Multiplexed imaging in live cells using pulsed interleaved excitation spectral FLIM.

Multiplexed fluorescence detection has become increasingly important in the fields of biosensing and bioimaging. Although a variety of excitation/detection optical designs and fluorescence unmixing schemes have been proposed to allow for multiplexed imaging, rapid and reliable differentiation and quantification of multiple fluorescent species at each imaging pixel is still challenging. Here we present a pulsed interleaved excitation spectral fluorescence lifetime microscopic (PIE-sFLIM) system that can simultaneously image six fluorescent tags in live cells in a single hyperspectral snapshot.

Outcomes of liver transplantation for hepatocellular carcinoma: Experiences from a Vietnamese center.

Backgrounds/aims: Liver transplantation (LT) provides a favorable outcome for patients with hepatocellular carcinoma (HCC) and was launched in Vietnam in 2004. In this study, we evaluated the short-term and long-term outcomes of LT and its risk factors.

Methods: This retrospective study analyzed HCC patients who underwent LT at Viet Duc University hospital, Vietnam, from 01/2012-03/2022.

Two-motif model illuminates DICER cleavage preferences.

In humans, DICER is a key regulator of gene expression through its production of miRNAs and siRNAs by processing miRNA precursors (pre-miRNAs), short-hairpin RNAs (shRNAs), and long double-stranded RNAs (dsRNAs). To advance our understanding of this process, we employed high-throughput dicing assays using various shRNA variants and both wild-type and mutant DICER. Our analysis revealed that DICER predominantly cleaves shRNAs at two positions, specifically at 21 (DC21) and 22 (DC22) nucleotides from their 5'-end.

Recent Advances in Single-Molecule Tracking and Imaging Techniques.

Since the early 1990s, single-molecule detection in solution at room temperature has enabled direct observation of single biomolecules at work in real time and under physiological conditions, providing insights into complex biological systems that the traditional ensemble methods cannot offer. In particular, recent advances in single-molecule tracking techniques allow researchers to follow individual biomolecules in their native environments for a timescale of seconds to minutes, revealing not only the distinct pathways these biomolecules take for downstream signaling but also their roles in supporting life. In this review, we discuss various single-molecule tracking and imaging techniques developed to date, with an emphasis on advanced three-dimensional (3D) tracking systems that not only achieve ultrahigh spatiotemporal resolution but also provide sufficient working depths suitable for tracking single molecules in 3D tissue models.

SRSF7 and SRSF3 depend on RNA sequencing motifs and secondary structures to regulate Microprocessor.

Human Microprocessor cleaves pri-miRNAs to initiate miRNA biogenesis. The accuracy and efficiency of Microprocessor cleavage ensure appropriate miRNA sequence and expression and thus its proper gene regulation. However, Microprocessor cleaves many pri-miRNAs incorrectly, so it requires assistance from many cofactors.

Dissection of the Caenorhabditis elegans Microprocessor.

Microprocessor (MP) is a complex involved in initiating the biogenesis of microRNAs (miRNAs) by cleaving primary microRNAs (pri-miRNAs). miRNAs are small single-stranded RNAs that play a key role in the post-transcriptional regulation of gene expression. Thus, understanding the molecular mechanism of MP is critical for interpreting the roles of miRNAs in normal cellular processes and during the onset of various diseases.

Generative adversarial network enables rapid and robust fluorescence lifetime image analysis in live cells.

Fluorescence lifetime imaging microscopy (FLIM) is a powerful tool to quantify molecular compositions and study molecular states in complex cellular environment as the lifetime readings are not biased by fluorophore concentration or excitation power. However, the current methods to generate FLIM images are either computationally intensive or unreliable when the number of photons acquired at each pixel is low. Here we introduce a new deep learning-based method termed flimGANE (fluorescence lifetime imaging based on Generative Adversarial Network Estimation) that can rapidly generate accurate and high-quality FLIM images even in the photon-starved conditions.

The conserved single-cleavage mechanism of animal DROSHA enzymes.

RNase III enzymes typically cleave both strands of double-stranded RNAs (dsRNAs). We recently discovered that a human RNase III, DROSHA, exhibits a single cleavage on the one strand of primary microRNAs (pri-miRNAs). This study revealed that DROSHAs from the other animals, including worms and flies, also show the single cleavage on dsRNAs.

Availability, prices and affordability of essential medicines: A cross-sectional survey in Hanam province, Vietnam.

Objective: To measure medicines' prices, availability, and affordability in Hanam, Vietnam.

Methods: The standardized methodology developed by the World Health Organization (WHO) and Health Action International was used to survey 30 essential medicines (EMs) in 30 public health facilities and 35 private medicine outlets in 2020. The availability of medicine was computed as the percentage of health facilities in which this medicine was found on the data-collection day.

Monodisperse and size-tunable high-quality factor microsphere biolasers.

Microsphere biolasers have attracted a great deal of interest due to their potential for biosensing and cell tracking. Here we demonstrate a novel, to the best of our knowledge, microfluidic-based fabrication of nearly monodisperse dye-doped protein microsphere biolasers with a tunable size from 150 to 50 µm. In particular, for an 85 µm-bead, about 70% of the fabricated microspheres have the same size of 85 µm.

Bulges control pri-miRNA processing in a position and strand-dependent manner.

MicroRNAs (miRNAs) play critical roles in gene expression and numerous human diseases. The success of miRNA biogenesis is largely determined by the primary miRNA (pri-miRNA) processing by the DROSHA-DGCR8 complex, called Microprocessor. Here, we analysed the high-throughput pri-miRNA processing assays and secondary structures of pri-miRNAs to investigate the roles of bulges in the pri-miRNA processing.

Human disease-associated single nucleotide polymorphism changes the orientation of DROSHA on pri-mir-146a.

The Microprocessor complex of DROSHA and DGCR8 initiates the biosynthesis of microRNAs (miRNAs) by processing primary miRNAs (pri-miRNAs). The Microprocessor can be oriented on pri-miRNAs in opposite directions to generate productive and unproductive cleavages at their basal and apical junctions, respectively. However, only the productive cleavage gives rise to miRNAs.