A descriptive analysis of sporadic Creutzfeldt-Jakob cases in Vietnam: 31 patients from four tertiary care centers.

Background: Accurate diagnosis of sCJD remains challenging in developing countries such as Vietnam, as clinical and research efforts focus on treatable diseases. Several cases of sCJD have been diagnosed in Vietnam but data from formal analyses are lacking. This is the first systematic analysis of patients with sCJD in Vietnam.

Rapid Access to Conjugated Z,Z,Z-Trienes.

Intercepting reactions have recently emerged as an innovative approach in organic synthesis, allowing chemists to harness reactive intermediates to access structures and functionalities that conventional methods cannot easily achieve. By deliberately manipulating reaction pathways, this strategy provides a unique avenue to explore unusual reactivities and complex molecular architectures. In this work, we have developed a new protocol for the nucleophile-intercepted Beckmann fragmentation reaction (NuBFr).

A 1,2-Aryl Migration Reaction in Visible-Light-Mediated Synthesis of Quinoxaline Derivatives: Mechanistic Studies.

The synthesis of quinoxaline derivatives holds critical importance in various fields ranging from pharmaceuticals to material science. In this study, we introduce a practical light-mediated method for the efficient synthesis of quinoxaline derivatives. This approach enabled the sequential two-step, one-pot synthesis of 1,2-dihydro-2,2-diaryl-substituted quinoxalines from quinones, alkynes, and diamines.

Comparing smell identification ability among different motor subtypes of Parkinson's disease using the Vietnamese Smell Identification Test and the Brief Smell Identification Test.

Introduction: Olfactory dysfunction is one of the most common non-motor symptoms of Parkinson's disease (PD). The association between smell identification ability and motor subtypes of PD is not uniform in previous studies. This study aimed to compare the odor identification ability among different motor subtypes of PD in Vietnamese participants.

N-Heterocyclic Carbenes and N-Heterocycles as Synthetic Reagents and Building Blocks.

N-Heterocyclic carbenes (NHCs) have become important tools in modern synthetic chemistry due to their versatility as organocatalysts and ligands in organometallic complexes. Since their first isolation and characterization, NHCs have demonstrated significant utility in various catalytic processes, offering advantages such as strong σ-electron donation and the ability to stabilize reactive intermediates. However, beyond their well-documented roles in catalysis, the potential of NHCs as stoichiometric reagents and synthetic building blocks remains an underexplored yet promising area.

Controlling the regioselectivity of the bromolactonization reaction in HFIP.

The halolactonization reaction provides rapid access to densely functionalized lactones from unsaturated carboxylic acids. The / regioselectivity of this cyclization reaction is primarily determined by the electronic stabilization of alkene substituents, thus making it inherently dependent on substrate structures. Therefore this method often affords one type of halolactone regioisomer only.

Personalised Medicine and the Potential Role of Electrospinning for Targeted Immunotherapeutics in Head and Neck Cancer.

Advanced head and neck cancer (HNC) is functionally and aesthetically destructive, and despite significant advances in therapy, overall survival is poor, financial toxicity is high, and treatment commonly exacerbates tissue damage. Although response and durability concerns remain, antibody-based immunotherapies have heralded a paradigm shift in systemic treatment. To overcome limitations associated with antibody-based immunotherapies, exploration into de novo and repurposed small molecule immunotherapies is expanding at a rapid rate.

Fractionation, identification of chemical constituents, and biological properties of cashew ( L.) leaf extracts.

The current study aimed to identify the chemical constituents and bioactivities of the crude ethanolic extract (CEE) and its fractions (ethyl acetate (EAF), hexane (HEF), and aqueous (AEF)) from leaves of cashew ( L.) grown in Vietnam. A total of 31 compounds which belong to alkanes, hydrocarbons, iodine, terpenoids, phenolics, and flavonoids were determined by a gas chromatography-mass spectrometry (GC-MS) analysis, with bis(2-ethylhexyl) phthalate being the most prevailing compound.

Moisture-Assisted Hydroboration of Nitriles and Conversion Thereof to -Heterocyles and -Containing Derivatives.

The recent revelation of hidden-borane catalysis has revolutionized the field of catalytic hydroboration in organic synthesis. Many nucleophilic reaction promoters, previously believed to be the catalysts, in fact primarily facilitated the formation of borane (BH), which subsequently acted as the true catalyst. This revelation prompted us to explore the untapped potential of these unexpected transformations, with a view to simplify hydroboration using more cost-effective and environmentally friendly nucleophilic precatalysts.

Olefination of Aromatic Carbonyls via Site-Specific Activation of Cycloalkanone Ketals.

Skeletal editing is an important strategy in organic synthesis as it modifies the carbon backbone to tailor molecular structures with precision, enabling access to compounds with specific desired properties. Skeletal editing empowers chemists to transform synthetic approaches of target compounds across diverse applications from drug discovery to materials science. Herein, we introduce a new skeletal editing method to convert readily available aromatic carbonyl compounds into valuable unsaturated carboxylic acids with extended carbon chains.

Normative data for the Vietnamese smell identification test.

Introduction: The 12-item Vietnamese smell identification test (VSIT) has been developed to evaluate the olfactory function of the Vietnamese population. This study aimed to investigate the normative value of the VSIT in different age groups and sexes.

Methods: This cross-sectional study was conducted at Ho Chi Minh University Medical Center, Vietnam.

Development and validation of the Vietnamese smell identification test.

Background: Correct olfactory identification requires familiarity with the odor stimuli and is culturally dependent. Existing smell identification tests (SIT) are not culturally specific and may not be reliable in detecting hyposmia in all populations. This study aimed to develop a smell identification test suitable for Vietnamese patients (VSIT).

Microfluidic platform using focused ultrasound passing through hydrophobic meshes with jump availability.

Applications in chemistry, biology, medicine, and engineering require the large-scale manipulation of a wide range of chemicals, samples, and specimens. To achieve maximum efficiency, parallel control of microlitre droplets using automated techniques is essential. Electrowetting-on-dielectric (EWOD), which manipulates droplets using the imbalance of wetting on a substrate, is the most widely employed method.

Reversible leukoencephalopathy associated with organotin poisoning.

Introduction: Organotin compounds are widely used in the plastic industry. We demonstrate the role of brain magnetic resonance imaging in a patient with leukoencephalopathy.

Clinical Course: A 38-year-old man who worked with trimethyltin and dimethyltin in a polyvinyl chloride factory reported a two-week progression of impaired memory, loss of balance, apathy, tinnitus, scaly darkened skin, and psychomotor slowing that rendered him unable to continue his daily activities.

Highly sensitive low-frequency-detectable acoustic sensor using a piezoresistive cantilever for health monitoring applications.

This study investigates a cantilever-based pressure sensor that can achieve a resolution of approximately 0.2 mPa, over the frequency range of 0.1-250 Hz.

Temperature Dependence of the Beating Frequency of hiPSC-CMs Using a MEMS Force Sensor.

It is expected that human iPS cell-derived cardiomyocytes (hiPSC-CMs) can be used to treat serious heart diseases. However, the properties and functions of human adult cardiomyocytes and hiPSC-CMs, including cell maturation, differ. In this study, we focused on the temperature dependence of hiPSC-CMs by integrating the temperature regulation system into our sensor platform, which can directly and quantitatively measure their mechanical motion.

Toward Homogeneous Brønsted-Acid-Catalyzed Intramolecular Carbonyl-Olefin Metathesis Reactions.

The carbonyl-olefin metathesis (COM) reaction is an attractive approach for the formation of a new carbon-carbon double bond from a carbonyl precursor. In principle, this reaction can be promoted by the activation of the carbonyl group with a Brønsted acid catalyst; however, it is often complicated as a result of unwanted side reactions under acidic conditions. Thus, there have been only a very few examples of Brønsted-acid-catalyzed COM reactions, all of which required specially designed setups.

Wide bandgap semiconductor nanomembranes as a long-term biointerface for flexible, implanted neuromodulator.

Electrical neuron stimulation holds promise for treating chronic neurological disorders, including spinal cord injury, epilepsy, and Parkinson's disease. The implementation of ultrathin, flexible electrodes that can offer noninvasive attachment to soft neural tissues is a breakthrough for timely, continuous, programable, and spatial stimulations. With strict flexibility requirements in neural implanted stimulations, the use of conventional thick and bulky packages is no longer applicable, posing major technical issues such as short device lifetime and long-term stability.

Frequency Characteristics of Pulse Wave Sensor Using MEMS Piezoresistive Cantilever Element.

Wearable sensor devices with minimal discomfort to the wearer have been widely developed to realize continuous measurements of vital signs (body temperature, blood pressure, respiration rate, and pulse wave) in many applications across various fields, such as healthcare and sports. Among them, microelectromechanical systems (MEMS)-based differential pressure sensors have garnered attention as a tool for measuring pulse waves with weak skin tightening. Using a MEMS-based piezoresistive cantilever with an air chamber as the pressure change sensor enables highly sensitive pulse-wave measurements to be achieved.

A new deep learning approach based on bilateral semantic segmentation models for sustainable estuarine wetland ecosystem management.

Nowadays, estuarial areas have been strongly affected by the construction of electrical power dams from upstream, downstream urbanization and many types of hazards along the coastal regions. It has resulted in significant changes in estuarine wetland ecosystems between rainy and dry seasons. To avoid estuary vulnerability, monitoring and evaluation of the estuarine ecosystems are very critical tasks.

Ring Contraction of Tropylium Ions into Benzenoid Derivatives.

We report a method to convert substituted tropylium ions into benzenoid derivatives.

Hydrogen Bonding Networks Enable Brønsted Acid-Catalyzed Carbonyl-Olefin Metathesis.

Synthetic chemists have learned to mimic nature in using hydrogen bonds and other weak interactions to dictate the spatial arrangement of reaction substrates and to stabilize transition states to enable highly efficient and selective reactions. The activation of a catalyst molecule itself by hydrogen-bonding networks, in order to enhance its catalytic activity to achieve a desired reaction outcome, is less explored in organic synthesis, despite being a commonly found phenomenon in nature. Herein, we show our investigation into this underexplored area by studying the promotion of carbonyl-olefin metathesis reactions by hydrogen-bonding-assisted Brønsted acid catalysis, using hexafluoroisopropanol (HFIP) solvent in combination with para-toluenesulfonic acid (pTSA).

Unusual Alternating Crystallization-Induced Emission Enhancement Behavior in Nonconjugated ω-Phenylalkyl Tropylium Salts.

The alternating physical properties, especially melting points, of α,ω-disubstituted -alkanes and their parent -alkanes had been known since Baeyer's report in 1877. There is, however, no general and comprehensive explanation for such a phenomenon. Herein, we report the synthesis and examination of a series of novel ω-phenyl -alkyl tropylium tetrafluoroborates, which also display alternation in their physicochemical characters.

Tropylium-promoted Ritter reactions.

The Ritter reaction used to be one of the most powerful synthetic tools to functionalize alcohols and nitriles, providing valuable -alkyl amide products. However, this reaction has not been frequently used in modern organic synthesis due to its employment of strongly acidic and harsh reaction conditions, which often lead to complicated side reactions. Herein, we report the development of a new method using salts of the tropylium ion to promote the Ritter reaction.