Multifunctional self-priming hairpin probe-based isothermal nucleic acid amplification and its applications for COVID-19 diagnosis.

We herein present a multifunctional self-priming hairpin probe-based isothermal amplification, termed MSH, enabling one-pot detection of target nucleic acids. The sophisticatedly designed multifunctional self-priming hairpin (MSH) probe recognizes the target and rearranges to prime itself, triggering the amplification reaction powered by the continuously repeated extension, nicking, and target recycling. As a consequence, a large number of double-stranded DNA (dsDNA) amplicons are produced that could be monitored in real-time using a dsDNA-intercalating dye.

A personal glucose meter-utilized strategy for portable and label-free detection of hydrogen peroxide.

Rapid and precise detection of hydrogen peroxide (HO) holds great significance since it is linked to numerous physiological and inorganic catalytic processes. We herein developed a label-free and washing-free strategy to detect HO by employing a hand-held personal glucose meter (PGM) as a signal readout device. By focusing on the fact that the reduced redox mediator ([Fe(CN)]) itself is responsible for the final PGM signal, we developed a new PGM-based strategy to detect HO by utilizing the target HO-mediated oxidation of [Fe(CN)] to [Fe(CN)] in the presence of horseradish peroxidase (HRP) and monitoring the reduced PGM signal in response to the target amount.

Ultrasensitive fluorescence microRNA biosensor by coupling hybridization-initiated exonuclease I protection and tyramine signal amplification.

Tyramine signal amplification (TSA) has made its mark in immunoassay due to its excellent signal amplification ability and short reaction time, but its application in nucleic acid detection is still very limited. Herein, an ultrasensitive microRNA (miRNA) biosensor by coupling hybridization-initiated exonuclease I (Exo I) protection and TSA strategy was established. Target miRNA is complementarily hybridized to the biotin-modified DNA probe to form a double strand, which protects the DNA probe from Exo I hydrolysis.

Natural Oleanolic Acid-Tailored Eutectogels Featuring Multienvironment Shape Memory Performance.

Shape memory gels, one of the primary modern smart materials, hold great promise in a myriad of applications spanning from soft robotics to medical devices. Nevertheless, most shape memory gels rely on water, organic solvents, and ionic liquids as dispersion mediums, posing the risks of freezing, dehydration, and toxicity to humans or environment. Herein, we have developed a thermoresponsive shape memory eutectogel by introducing an oleanolic acid-modified polyacrylamide network into a deep eutectic solvent (DES).

Clinical and molecular predictors of mortality in patients with carbapenem-resistant Acinetobacter baumannii bacteremia: A retrospective cohort study.

Background/purpose: To investigate the virulence profiles and identify clinical and microbiological predictors of mortality in patients with carbapenem-resistant Acinetobacter baumannii (A. baumannii) bacteremia.

Methods: This retrospective cohort study enrolled adult patients with carbapenem-resistant A.

Molecular and virulence characteristics of carbapenem-resistant Acinetobacter baumannii isolates: a prospective cohort study.

This study aimed to characterize the molecular features and virulence profiles of carbapenem-resistant Acinetobacter baumannii (CRAB) isolates. Clinical CRAB isolates were obtained from blood cultures of adult patients with CRAB bacteremia, collected between July 2015 and July 2021 at a Korean hospital. Real-time polymerase chain reaction was used to detect 13 virulence genes, genotyping was conducted via multilocus sequence typing (MLST), and a Tenebrio molitor infection model was selected for survival analysis.

High-selective two-site fluorescent probe for Cys/SO detection and cell imaging.

A fluorescent probe has been designed using cyanine phenothiazine and 7-nitro-1,2,3-benzoxadiazole (NBD) for selective detection of Cys-SO components. The probe utilizes the NBD structure to achieve specificity towards Cys and employs a reaction mechanism between the double bond of cyanine and phenothiazine with SO to achieve selectivity towards SO. Importantly, the NBPI phenothiazine structure incorporates a large C-O bond energy attached to NBD, effectively eliminating interference from Hcy and ensuring highly selective response to Cys.

Ultrasensitive Isothermal Detection of SARS-CoV-2 Based on Self-Priming Hairpin-Utilized Amplification of the G-Rich Sequence.

The outbreak of the novel coronavirus disease 2019 (COVID-19) pandemic induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused millions of fatalities all over the world. Unquestionably, the effective and timely testing for infected individuals is the most imperative for the prevention of the ongoing pandemic. Herein, a new method was established for detecting SARS-CoV-2 based on the self-priming hairpin-utilized isothermal amplification of the G-rich sequence (SHIAG).

Acoustic Resonance Testing of Small Data on Sintered Cogwheels.

Based on the fact that cogwheels are indispensable parts in manufacturing, we present the acoustic resonance testing (ART) of small data on sintered cogwheels for quality control in the context of non-destructive testing (NDT). Considering the lack of extensive studies on cogwheel data by means of ART in combination with machine learning (ML), we utilize time-frequency domain feature analysis and apply ML algorithms to the obtained feature sets in order to detect damaged samples in two ways: one-class and binary classification. In each case, despite small data, our approach delivers robust performance: All damaged test samples reflecting real-world scenarios are recognized in two one-class classifiers (also called detectors), and one intact test sample is misclassified in binary ones.

Bioinspired Polyacrylamide/(polyvinyl alcohol-copper acetate) Hydrogel with Cooling-Triggered Shape Memory, Color Changing, and Self-Healing Behavior.

Inspired by many living creatures with adjustment of shape and color in an ever-changing environment, color changeable shape memory hydrogels are designed and expected to be potential candidates in the fields spanning from anti-counterfeiting to biomedical devices. However, they normally require complex synthesis, and more importantly, the cooling-induced shape recovery hydrogel is still rare and in its infancy so far. Herein, a unique color changeable shape memory hydrogel by simply incorporating polyvinylalcohol and copper acetate into covalent polyacrylamide network is developed.

A study on the performance of the Donation Improvement Program in Korea.

Background: The Donation Improvement Program (DIP) is intended to increase organ donation at hospitals. The program includes education for healthcare professionals of participating hospitals about each step of donation as well as evaluation. The DIP consists of medical record review (MRR) and a Hospital Attitude Survey (HAS).

Palindromic hyperbranched rolling circle amplification enabling ultrasensitive microRNA detection.

We herein describe a palindromic hyperbranched rolling circle amplification (PH-RCA) reaction and its application for ultrasensitive detection of microRNAs (miRNAs). In this strategy, target miRNAs bind to a dumb-bell probe (DP) and initiate the RCA reactions, concomitantly converting the dumb-bell structure to the circular form, which then allows the annealing of the palindromic primers to promote an additional two RCA reactions. As a consequence of the RCA reactions promoted by both target miRNAs and palindromic primers, multiple long concatenated DNA strands would be produced.

In vitro synergistic antimicrobial activity of a combination of meropenem, colistin, tigecycline, rifampin, and ceftolozane/tazobactam against carbapenem-resistant Acinetobacter baumannii.

We investigated the in vitro activity of various antimicrobial combinations against carbapenem-resistant Acinetobacter baumannii (CRAB) isolates. The in vitro activity of six two-drug combinations against CRAB isolates collected from the blood samples of patients with bloodstream infection was evaluated using the checkerboard method and time-kill assay [0.5 ×, 1 ×, and 2 × minimum inhibitory concentration (MIC)] to identify potential synergistic and bactericidal two-drug combinations against CRAB isolates.

PEGylated near-infrared fluorescence probe for mitochondria-targetable hydrogen peroxide detection.

Oxidative stress plays significant roles in the development of various diseases. HO acts as a signaling molecule physiologically or harmful substance pathologically and the mitochondria are one of the most active places for the generation of HO. Thus, a new mitochondria-targeted probe 1 for HO detection was synthesized herein, based on D-π-A structure with a large Stokes shift (150 nm) due to its ICT process.

Rapid and accurate clinical testing for COVID-19 by nicking and extension chain reaction system-based amplification (NESBA).

We herein describe rapid and accurate clinical testing for COVID-19 by nicking and extension chain reaction system-based amplification (NESBA), an ultrasensitive version of NASBA. The primers to identify SARS-CoV-2 viral RNA were designed to additionally contain the nicking recognition sequence at the 5'-end of conventional NASBA primers, which would enable nicking enzyme-aided exponential amplification of T7 RNA promoter-containing double-stranded DNA (T7DNA). As a consequence of this substantially enhanced amplification power, the NESBA technique was able to ultrasensitively detect SARS-CoV-2 genomic RNA (gRNA) down to 0.

Ultrasensitive version of nucleic acid sequence-based amplification (NASBA) utilizing a nicking and extension chain reaction system.

Nucleic acid sequence-based amplification (NASBA) is a transcription-based isothermal amplification technique especially designed for the detection of RNA targets. The NASBA basically relies on the linear production of T7 RNA promoter-containing double-stranded DNA (T7DNA), and thus the final amplification efficiency is not sufficiently high enough to achieve ultrasensitive detection. We herein ingeniously integrate a nicking and extension chain reaction system into the NASBA to establish an ultrasensitive version of NASBA, termed Nicking and Extension chain reaction System-Based Amplification (NESBA).

A caged 2-hydroxyethyl luciferin for bioluminescence imaging of nitroxyl in living cells.

Nitroxyl (HNO), a one-electron reduction product of nitric oxide, demonstrates distinct biological and pharmacological activities. Here we designed a bioluminescent turn-on probe, HNO-8, that could be used to visualize HNO without the need for excitation light. HNO-8 was prepared by caging 2-hydroxyethyl luciferin with a triphenylphosphine unit, in which 2-hydroxyethyl luciferin as a novel substrate of firefly luciferase was characterized by stronger and more sustained bioluminescent signals than the most popular substrates of d-luciferin and 6'-aminoluciferin.

Tough, Stretchable, Compressive Double Network Hydrogel Using Natural Glycyrrhizic Acid Tailored Low-Molecular-Weight Gelator Strategy: In Situ Spontaneous Formation of Au Nanoparticles To Generate a Continuous Flow Reactor.

Traditional solid supports of metal nanoparticles (MNPs) often suffer from the poor mechanical performance, the low recycling efficiency, and the mass loss in the regeneration process. To overcome this limit, in this work, we reported a natural triterpenoid-tailored low-molecular-weight gelator (LMWG) strategy to fabricate double network (DN) hydrogels with excellent mechanical properties for supporting MNPs. In this strategy, the supramolecular fibrillar structure of glycyrrhizic acid (GL) and the cross-linked polyacrylamide (PAAm) were used as the first physical network and the second chemical network, respectively.

Bioluminescence imaging of carbon monoxide in living cells based on a selective deiodination reaction.

d-Luciferin is a popular bioluminescent substrate of luciferase in the presence of ATP. It is used in luciferase-based bioluminescence imaging and cell-based high-throughput screening applications. Herein, the iodination of d-luciferin was undertaken and explored as a bioluminescence probe without the need for light excitation to sensitively trace and image carbon monoxide (CO) in liver cancer cells.

[ infection by blood transfusion：a case report].

This paper reported one acute lymphoblastic leukemia patient who infected with after blood transfusion. Through the epidemiological investigation on this patient and the related blood donors as well as laboratory detections, the source of infection was ascertained. This blood donor was an overseas student from Africa, whose blood sample was positive in the rapid diagnostic test, and the results of microscopic examination of peripheral blood smear and PCR both suggested positive.

Multi-stimuli-responsive hydrogels of gluconamide-tailored anthracene.

In this work, two amphiphilic gluconamide-tailored anthracene gelators 1 and 2 have been synthesized, and found to form stable hydrogels with fibril structures. The stimuli-responsive behaviors of hydrogel 1 and 2 were investigated thoroughly by temperature-dependent 1H NMR, UV-Vis, rheometry, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The results showed that hydrogel 1 exhibited multiple responsive behaviours upon exposure to stimuli including temperature, anions, light, electron-deficient chemicals and external stress; conversely, hydrogel 2 showed a distinct responsive phenomenon attributed to a subtle structural difference in the linker.

Biobased polymeric surfactant: Natural glycyrrhizic acid-appended homopolymer with multiple pH-responsiveness.

Even though amphiphilic natural products have been widely employed in cosmetics, food, and pesticide formulations, the development of a compound with stimuli-responsiveness is still highly significant. Inspired by the low cost, biocompatibility, pH resistance and amphiphilicity of natural glycyrrhizic acid (Gly), we designed and synthesized an amphiphilic homopolymer, namely, poly(glycyrrhizic acid) (PGly), via reversible addition-fragmentation chain transfer (RAFT) polymerization. The two carboxylic groups on the side chain of PGly promoted it as a multiple pH-responsive polymeric surfactant.

Natural-Product-Tailored Polyurethane: Size-Dictated Construction of Polypseudorotaxanes with Cyclodextrin-Triterpenoid Pairs.

Cyclodextrin (CD)-based polyrotaxanes (PRs) and polypseudorotaxanes (PPRs) have attracted considerable attention due to their unique topological structures and functions. However, limited by the simple chemical structures and the single functionalization of guest polymer units like poly(ethylene glycol) (PEG) and poly(propylene glycol) (PPG), to date the construction of CD-based PRs and PPRs with precisely controllable supramacromolecular structures is fairly rare. In this work, two kinds of molecular necklace-like PPRs with CD-triterpenoid pairs were prepared via the size-dictated construction, where the threaded guest polymer was a natural product-tailored polyurethane (PU-PEG-GA) with the alternating structure of triterpenoid and PEG segments via a simple step-growth polymerization.

Natural Triterpenoid- and Oligo(Ethylene Glycol)-Pendant-Containing Block and Random Copolymers: Aggregation and pH-Controlled Release.

In this research, a series of random and block amphiphilic copolymers of norbornene derivatives containing biocompatible natural triterpenoid and oligo(ethylene glycol) pendants were synthesized by ring-opening metathesis polymerization. These copolymers were heat and pH responsive, and could self-assemble into core-shell spherical micelles in aqueous solution. Their hydrodynamic diameters corresponded to pH values and monomer sequences.