Engineered Aptamer-Derived Fluorescent Aptasensor: the Label-Free, Single-Step, Rapid Detection of Vancomycin in Clinical Samples.

Currently, the reported vancomycin (VCM) aptamers, including the 3- (K =  9.13 × 10 m) and 4-truncated variants (K = 45.5 × 10 m), are engineered via stem truncation of the VCM parent aptamer, which inevitably compromises their affinities, thus affecting their clinical application within the VCM therapeutic window of 6.

First Report of Causing Postharvest Bulb Rot on var. in China.

Lilium davidii var. willmottiae, known as Lanzhou lily, is a famous edible crop that is mostly distributed in the middle area of Gansu Province in China. In the winter of 2019, symptoms of bulb rot were observed on Lanzhou lilies harvested from Lanzhou, Gansu Province, during storage at the Institute of Grassland, Flowers and Ecology (39°57'55.

Vancomycin trough concentration in adult patients with periprosthetic joint infection: A machine learning-based covariate model.

Aims: Although there are various model-based approaches to individualized vancomycin (VCM) administration, few have been reported for adult patients with periprosthetic joint infection (PJI). This work attempted to develop a machine learning (ML)-based model for predicting VCM trough concentration in adult PJI patients.

Methods: The dataset of 287 VCM trough concentrations from 130 adult PJI patients was split into a training set (229) and a testing set (58) at a ratio of 8:2, and an independent external 32 concentrations were collected as a validation set.

Precise Differentiation of Wobble-Type Allele via Ratiometric Design of a Ligase Chain Reaction-Based Electrochemical Biosensor for Genotyping of Clinical Samples.

Due to the comparable stability between the perfect-base pair and the wobble-base pair, a precise differentiation of the wobble-type allele has remained a challenge, often leading to false results. Herein, we proposed a ligase chain reaction (LCR)-based ratiometric electrochemical DNA sensor, namely, R-eLCR, for a precise typing of the wobble-type allele, in which the traditionally recognized "negative" signal of wobble-base pair-mediated amplification was fully utilized as a "positive" one and a ratiometric readout mode was employed to ameliorated the underlying potential external influence and improved its detection accuracy in the typing of the wobble-type allele. The results showed that the ratio between current of methylene blue () and current of ferrocene () was partitioned in three regions and three types of wobble-type allele were thus precisely differentiated (AA homozygote: / > 2; GG homozygote: / < 1; GA heterozygote: 1 < / < 2); the proposed R-eLCR successfully discriminated the three types of allele in nine cases of human whole blood samples, which was consistent with those of the sequencing method.

Nucleic Acid Amplification by Template-Dominated Click Chemistry for Ultrasensitive DNA/RNA Detection on an Electrochemical Readout Platform.

As an enzyme-free exponential nucleic acid amplification method, the click chemistry-mediated ligation chain reaction (ccLCR) has shown great prospects in the molecular diagnosis. However, the current optics-based ccLCR is challenged by remarkable nonspecific amplification, severely hindering its future application. This study demonstrated that the severe nonspecific amplification was generated probably due to high random collision in the high DNA probe concentration (μM level).

Cell viability and drug evaluation biosensing system based on disposable AuNPs/MWCNT nanocomposite modified screen-printed electrode for exocytosis dopamine detection.

Cell viability, as an important index to evaluate drug effects, usually was measured by tetrazolium colorimetric assay, playing a key role in drug development and drug screening. Tedious operating procedures, unsatisfactory sensitivity and abominable environments perplex researchers to acquire more detailed in vivo-relevant biological information. Herein, a simple and low-cost cell viability and drug evaluation biosensing system-based on multiwalled carbon nanotubes, gold nanoparticles and Nafion modified screen-printed electrode (SPE) biosensor was constructed for detection of dopamine (DA) released from living cells to evaluate cytotoxicity of antineoplastic drugs such as cisplatin and resveratrol.

Wearable Real-Time Gesture Recognition Scheme Based on A-Mode Ultrasound.

A-mode ultrasound has the advantages of high resolution, easy calculation and low cost in predicting dexterous gestures. In order to accelerate the popularization of A-mode ultrasound gesture recognition technology, we designed a human-machine interface that can interact with the user in real-time. Data processing includes Gaussian filtering, feature extraction and PCA dimensionality reduction.

Multimodal Ochratoxin A-Aptasensor Using 3'-FAM-Enhanced Exonuclease I Tool and Magnetic Microbead Carrier.

Thanks to its preparatory ease, close affinity, and low cost, the aptasensor can serve as a promising substitute for antibody-dependent biosensors. However, the available aptasensors are mostly subject to a single-mode readout and the interference of unbound aptamers in solution and non-target-induced transition events. Herein, we proposed a multimodal aptasensor for multimode detection of ochratoxin A (OTA) with cross-validation using the 3'-6-carboxyfluorescein (FAM)-enhanced exonuclease I (Exo I) tool and magnetic microbead carrier.

A Novel M6A-Related Genes Signature Can Impact the Immune Status and Predict the Prognosis and Drug Sensitivity of Lung Adenocarcinoma.

Lung adenocarcinoma (LUAD) is a primary cause of cancer-related death around the world and has a poor outcome and high incidence. Treatment options are, however, restricted. One of the most critical factors in cancer and metastasis is the N6-methyladenine (m6A) alteration on RNA.

DNA Nanosieve-Based Regenerative Electrochemical Biosensor Utilizing Nucleic Acid Flexibility for Accurate Allele Typing in Clinical Samples.

Herein, an interface-based DNA nanosieve that has the ability to differentiate ssDNA from dsDNA has been demonstrated for the first time. The DNA nanosieve could be readily built through thiol-DNA's self-assembly on the gold electrode surface, and its cavity size was tunable by varying the concentration of thiol-DNAs. Electrochemical chronocoulometry using [Ru(NH)] as redox revealed that the average probe-to-probe separation in the 1 μM thiol-DNA-modified gold electrode was 10.

Ultrasensitive Detection of RNA with Single-Base Resolution by Coupling Electrochemical Sensing Strategy with Chimeric DNA Probe-Aided Ligase Chain Reaction.

Accurate and sensitive detection of single-base mutations in RNAs is of great value in basic studies of life science and medical diagnostics. However, the current available RNA detection methods are challenged by heterogeneous clinical samples in which trace RNA mutants usually existed in a large pool of normal wild sequences. Thus, there is still great need for developing the highly sensitive and highly specific methods in detecting single-base mutations of RNAs in heterogeneous clinical samples.

A novel ligase chain reaction-based electrochemical biosensing strategy for highly sensitive point mutation detection from human whole blood.

Challenged by the detection of trace amounts of mutants and disturbance from endogenous substances in clinical samples, herein, we present a novel electrochemical biosensor based on ligase chain reaction (eLCR) via the thermostable ligase with high mutation recognizing ability. The lengthened double-stranded DNAs exponentially generated via LCR were uniformly distributed on a bovine serum albumin-modified gold electrode, in which the phosphate buffer was tactfully added to remove adsorbed uninterested-probes, and thereafter the amperometry current was collected for the specific binding of streptavidin-poly-HRP and subsequent catalysis in the 3, 3', 5, 5'-tetramethylbenzidine substrate that contained hydrogen peroxide. It found that, under optimized conditions, the proposed biosensor exhibited a high selectivity of mutant targets from the 10-fold excess of co-existent wild targets within a detection limit of 0.

Detection of Epidermal Growth Factor Receptor Gene Status via a DNA Electrochemical Biosensor Based on Lambda Exonuclease-assisted Signal Amplification.

Based on our previous work, we have constructed a new electrochemical biosensor to detect epidermal growth factor receptor (EGFR) gene mutation, which was a significant therapeutic effect predictor of target drugs for non-small cell lung cancer. In order to lower the detection limit to detect the small amount of EGFR gene status, we have employed lambda exonuclease (λ-Exo) to form a hybridization-digestion cycle. The reaction stages are depicted as follows: the target DNA hybridized with auxiliary DNA which had been modified with the λ-Exo recognition site; then, the double strands were cleaved by λ-Exo.

A Nanodrug Consisting Of Doxorubicin And Exosome Derived From Mesenchymal Stem Cells For Osteosarcoma Treatment In Vitro.

Purpose: The primary goal of the present study was to develop the nano-drug consisting of doxorubicin and exosome derived from mesenchymal stem cells, and to explore its effect on osteosarcoma in vitro.

Methods: The exosomes were isolated from bone marrow MSCs (BM-MSCs) by an Exosome Isolation Kit. The exosome-loaded doxorubicin (Exo-Dox) was prepared by mixing exosome with Dox-HCl, desalinizing with triethylamine and then dialyzing against PBS overnight.

Ultrasensitive Electrochemical Biosensor Developed by Probe Lengthening for Detection of Genomic DNA in Human Serum.

As an alternative to most of the reported nucleic acid amplification-based electrochemical DNA biosensors used for detection of trace levels of genomic DNA, we herein present a novel detection concept. The proposed system involves the conversion of two short double-stranded DNAs (dsDNAs), labeled with a thiol-tag or biotin-tag, into a single integrated dsDNA containing thiol and biotin at both terminals in the presence of target DNA through ligase chain reaction (LCR) and followed by the immobilization of these integrated dsDNAs on a bovine serum albumin (BSA)-modified gold electrode surface. Owing to rapid depletion of the two short dsDNAs via LCR, the integrated dsDNAs were generated in an exponential manner so that this sensoring approach offered a limit of detection of 25 yoctomoles (15 copies in 50 μL sample volumes), a high discrimination of single-base mismatch and a wide linear concentration range (across 6 orders of magnitude) for target DNA.

Facilely prepared low-density DNA monolayer-based electrochemical biosensor with high detection performance in human serum.

Presently, most reported electrochemical biosensors, for highly sensitive and selective detection of nucleic acid, still require multiple, time-consuming assembly steps and high-consumption DNA probes as well as lack good performance in human serum, which greatly limit their applicability. Herein, an easy-to-fabricate electrochemical DNA biosensor constructed by assembly of bovine serum albumin (BSA) followed with direct incubation of amplified products has been proposed. This method combined terminal deoxynucleoside transferase (TdTase)-mediated isothermal amplification and polyHRP catalysis to achieve dual-signal enhancement, and was featured with low-density DNA monolayer for its employment of only 2 nM capture probes.

Electrochemical DNA biosensor based on grafting-to mode of terminal deoxynucleoside transferase-mediated extension.

Previously reported electrochemical DNA biosensors based on in-situ polymerization approach reveal that terminal deoxynucleoside transferase (TdTase) has good amplifying performance and promising application in the design of electrochemical DNA biosensor. However, this method, in which the background is significantly affected by the amount of TdTase, suffers from being easy to produce false positive result and poor stability. Herein, we firstly present a novel electrochemical DNA biosensor based on grafting-to mode of TdTase-mediated extension, in which DNA targets are polymerized in homogeneous solution and then hybridized with DNA probes on BSA-based DNA carrier platform.