Screening of Cross-Reactive Aptamers for the Detection of 24 Quinolones by Using a Liebig's Law-Guided Parallel-Series Strategy.

Quinolones, a widely used class of antibiotics, present significant environmental and health concerns if they excessively remain in the environment and in food. Aptamers specific to quinolones can be applied as bioreceptors for the detection of quinolone residues in the environment and food. The quinolone family contains dozens of different individuals that share the same core structure coupled with various substituents at six different positions. The diversity and complexity of the substitution sites make it a challenge to choose a set of representative molecules that encompass all the desired sites and preserve the core molecular framework for the screening of quinolone-specific aptamers via systematic evolution of ligands by exponential enrichment (SELEX). To address this challenge, we introduce a novel parallel-series strategy guided by Liebig's law for isolating quinolone-specific cross-reactive aptamers by using the library-immobilized SELEX method. Through this approach, we successfully identified 5 aptamers (Apt.AQ01-Apt.AQ05) with high binding affinity and excellent specificity to 24 different quinolone individuals. Among them, Apt.AQ03 showcased optimal performance with affinities ranging from 0.14 to 1.07 µM across the comprehensive set of 24 quinolones, exhibiting excellent specificity against nontarget interferents. The binding performance of Apt.AQ03 was further characterized with microscale thermophoresis, circular dichroism spectra, and an exonuclease digestion assay. By using Apt.AQ03 as a bioreceptor, a fluorescence resonance energy transfer (FRET) aptasensor was developed for the detection of 24 quinolones in milk, achieving a remarkable detection limit of 14.5-21.8 ng/mL. This work not only establishes a robust and effective strategy for selecting cross-reactive aptamers applicable to other small-molecule families but also provides high-quality aptamers for developing various high-throughput and reliable methods for the detection of multiple quinolone residues in food.

Regulating the Growth Rate of Gold Nanobipyramids via a HCl-NADH-Ascorbic Acid System toward a Dual-Channel Multicolor Colorimetric Immunoassay for Simultaneously Screening and Detecting Multiple Sulfonamides.

It is an urgent need to develop simple and high-throughput methods for simultaneously screening and detecting multiple or groups of sulfonamides (SAs) in animal-derived foods since various SAs were alternately used in animal husbandry to avoid generating drug resistance. We herein developed a novel HCl-reduced nicotinamide adenine dinucleotide I (NADH)-ascorbic acid (AA)-mediated gold nanobipyramids (AuNBPs) growth system, which can precisely regulate the growth rate of AuNBPs, to generate two colorful and stable AA-corresponding multicolor signal channels with different sensitivities. Based on the HCl-NADH-AA-mediated AuNBP growth system, we further developed a dual-channel multicolor immunoassay for simultaneously realizing rapid screening and detection of 5 SAs (sulfamethazine, sulfamethoxydiazine, sulfisomidine, sulfamerazine, and sulfamonomethoxine) by using a paper-based analytical device for sensitively and stably reading out the signal and a broad-specificity anti-SAs antibody as a bio-receptor. The developed immunoassay has more color changes, a wider linear range, excellent specificity and stability, and two multicolor signal channels (L-channel and H-channel) with different sensitivities. The H-channel exhibited 7-8 SAs-corresponding color changes and can be used to detect 5 target SAs with a visual detection limit of 0.1-0.5 ng/mL and a spectrometry detection limit of 0.05-0.16 ng/mL. The L-channel exhibited 7-9 SAs-corresponding color changes and can be used to detect 5 target SAs with a visual detection limit of 2.0-6.0 ng/mL and a spectrometry detection limit of 0.40-1.47 ng/mL. The developed immunoassay was successfully used to simultaneously screen and detect low-concentration and high-concentration of target SAs in milk and fish muscle samples with a recovery of 85-110% and an RSD (n = 5) < 8%. The visual detection limit of our immunoassay is much lower than the maximum residue limit of total SAs in edible tissue. All above features make our immunoassay a promising assay for simultaneously realizing the rapid screening and quantitative determination of multiple SA residues in food by bare eye observation. It must be mentioned that our immunoassay may be expended as a general method for the simultaneous visual screening and detection of other drugs using the corresponding antibody as a recognition probe.

Series-temporal transcriptome profiling of cotton reveals the response mechanism of phosphatidylinositol signaling system in the early stage of drought stress.

Plants are sessile organisms suffering severe environmental conditions. Drought stress is one of the major environmental issues that affect plant growth and productivity. Although complex regulatory gene networks of plants under drought stress have been analyzed extensively, the response mechanism in the early stage of drought stress is still rarely mentioned. Here, we performed transcriptome analyses on cotton samples treated for a short time (10 min, 30 min, 60 min, 180 min) using 10% PEG, which is used to simulate drought stress. The analysis of differently expressed genes (DEGs) showed that the number of DEGs in roots was obviously more than that in stems and leaves at the four time points and maintained >2000 FDEGs (DEGs appearing for the first time) from 10 min, indicating that root tissues of plants respond to drought stress quickly and continuously strongly. Gene ontology (GO) analysis showed that DEGs in roots were mainly enriched in protein modification and microtubule-based process. DEGs were found significantly enriched in phosphatidylinositol signaling system at 10 min through Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, implying the great importance of phosphatidylinositol signal in the early stage of drought stress. What was more, two co-expression modules, which were significantly positively correlated with drought stress, were found by Weighted Gene Co-expression Network Analysis (WGCNA). From one of the co-expression modules, we identified a hub-gene Gohir.A07G058200, which is annotated as "phosphatidylinositol 3- and 4-kinase" in phosphatidylinositol signaling system, and found this gene may interact with auxin-responsive protein. This result suggested that Gohir.A07G058200 may be involved in the crosstalk of phosphatidylinositol signal and auxin signal in the early stage of drought stress. In summary, through transcriptome sequencing, we found that phosphatidylinositol signaling system is an important signal transduction pathway in early stage in response to drought stress, and it may interact with auxin signal transduction through phosphatidylinositol 3- and 4-kinase.

Research on the Time Drift Stability of Differential Inductive Displacement Sensors with Frequency Output.

An edge displacement sensor is one of the key technologies for building large segmented mirror astronomical optical telescopes. A digital interface is one novel approach for sensor technologies, digital transformation and the Internet of Things (IoT) in particular. Frequency output sensors and inductance-to-digital converter (LDC) demonstrated significant advantages in comparison with conventional sensors with analog-to-digital converter (ADC) interfaces. In order for the differential inductive frequency output displacement (DIFOD) sensor to meet the high-stability requirements of segmented mirror astronomical telescopes, it is important to understand the factors for time drift of the sensor. This paper focuses on the investigation of key factors of sensor structure and material, signal conditioning and interface, and fixtures for time drift to permanently installed applications. First, the measurement principle and probe structural characteristics of the sensor are analyzed. Then, two kinds of signal conditioning and digitalization methods using resonance circuits and LDC chips are implemented and compared. Finally, the time drift stability experiments are performed on the sensors with different signal conditioning methods and fixtures under controlled temperature. Experimental results show that the magnetic shield ring effectively improves the sensitivity and quality factor of the sensors, the time drift stability of the sensor using the signal conditioning based on resonance circuits is better than that of the sensors using LDC chips, and the root mean square (RMS) of the sensor time drift meets the requirement of 0.01 µm/24 h. This study will help further development of high-stability of frequency output sensors and IoT-based systems for scaled-up applications in the future.

A Multicolor Immunosensor for Sensitive Visual Detection of Breast Cancer Biomarker Based on Sensitive NADH-Ascorbic-Acid-Mediated Growth of Gold Nanobipyramids.

Many studies have demonstrated that the extracellular domain of human epidermal growth factor receptor 2 (HER2 ECD) level in serum can act as a breast cancer biomarker and serve as a monitoring neoadjuvant therapy of breast cancer. In this study, we developed a sensitive ascorbic acid (AA)-mediated AuNBPs (gold nanobipyramids) growth method with NADH (reduced nicotinamide adenine dinucleotide I) assistance, and we further fabricated a high-resolution multicolor immunosensor for sensitive visual detection of HER2 ECD in serum by using AuNBPs as signal and antibody as recognition probe. The NADH-assisted AA-mediated method effectively suppressed color formation in the blank and greatly improved the sensitivity of mediating AuNBPs growth, allowing us to use a low concentration of AA to mediate AuNBPs growth to generate more colorful and clearer color changes. The proposed multicolor immunosensor has higher resolution and more color changes corresponding to HER2 ECD concentrations. It can be used to detect as low as 0.5 ng/mL of HER2 ECD by bare eye observation and 0.05 ng/mL of HER2 ECD by UV-visible spectrophotometry. Using the immunosensor, we have successfully detected HER2 ECD in human serum with a recovery of 94%-96% and an RSD (n = 5) < 5%. The results obtained with our immunosensor were consistent with those obtained with ELISA, verifying the immunosensor has good accuracy. The immunosensor exhibited a vivid multicolor change, has low visual detection limit, excellent specificity and reproducibility, and robust resistance to matrix. All the above features makes our immunosensor a promising assay for the early diagnosis of HER2-dependent breast cancers in clinical diagnosis.

Introducing structure-switching functionality into small-molecule-binding aptamers via nuclease-directed truncation.

We report a broadly applicable enzyme digestion strategy for introducing structure-switching functionality into small-molecule-binding aptamers. This procedure is based on our discovery that exonuclease III (Exo III) digestion of aptamers is greatly inhibited by target binding. As a demonstration, we perform Exo III digestion of a pre-folded three-way-junction (TWJ)-structured cocaine-binding aptamer and a stem-loop-structured ATP-binding aptamer. In the absence of target, Exo III catalyzes 3'-to-5' digestion of both aptamers to form short, single-stranded products. Upon addition of target, Exo III digestion is halted four bases prior to the target-binding domain, forming a major target-bound aptamer digestion product. We demonstrated that target-binding is crucial for Exo III inhibition. We then determine that the resulting digestion products of both aptamers exhibit a target-induced structure-switching functionality that is absent in the parent aptamer, while still retaining high target-binding affinity. We confirm that these truncated aptamers have this functionality by using an exonuclease I-based digestion assay and further evaluate this characteristic in an electrochemical aptamer-based cocaine sensor and a fluorophore-quencher ATP assay. We believe our Exo III-digestion method should be applicable for the generation of structure-switching aptamers from other TWJ- or stem-loop-containing small-molecule-binding aptamers, greatly simplifying the generation of functionalized sensor elements for folding-based aptasensors.

D-penicillamine modified copper nanoparticles for fluorometric determination of histamine based on aggregation-induced emission.

A fluorometric method for the determination of histamine has been developed based on aggregation-induced emission (AIE) effect of D-penicillamine capped copper nanoparticles (DPA-CuNPs). The fluorescent DPA-CuNPs were synthesized by a one-pot method using D-penicillamine as both reducing agent and stabilizing ligand. The size, morphology and physical chemical properties of DPA-CuNPs were examined by transmission electron microscopy (TEM), fluorescence spectroscopy, fourier transform infrared spectroscopy (FTIR) and absorption spectroscopy. The DPA-CuNPs exhibit AIE effect and show intense red fluorescence (650 nm). In the presence of histamine, DPA-CuNPs are dispersed into small homogeneous particles, causing fluorescence quenching. Based on this reaction, a histamine sensor is constructed. The fluorescence of the CuNPs solution has a good linear relationship with histamine concentration in the range 0.05 µM to 5 µM and the determination limit (3σ/slope) is 30 nM. The estimated method was successfully applied to the determination of histamine in fish, pork and red wine. Graphical abstract Schematic representation of copper nanoparticles for histamine analysis. In the presence of histamine, the strong red fluorescence of copper nanoparticles is obvious decreased through interaction of copper nanoparticles and histamine.

Combination of Magnetic-Beads-Based Multiple Metal Nanoparticles Labeling with Hybridization Chain Reaction Amplification for Simultaneous Detection of Multiple Cancer Cells with Inductively Coupled Plasma Mass Spectrometry.

The high-throughput and rapid screening of cancer cells in blood is one of the most effective ways to realize clinical early diagnosis of cancer. We herein developed an inductively coupled plasma mass-spectrometry (ICP-MS)-based method for simultaneously counting two cancer cells, human hepatocellular carcinoma cell (SMMC-7721) and human lung carcinoma cell (A549), with high sensitivity and specificity. The method employed a magnetic-beads (MBs)-based dual aptamers-dual metal nanoparticles labeling technique for simultaneously recognizing and labeling different metal nanoparticles (AuNPs and AgNPs) on SMMC-7721 and A549 cancer cells, respectively, to generate ICP-MS signals, and a DNA hybridization chain reaction strategy for realizing "one SMMC-7721 cell-to-massive AuNPs" and "one A549 cell-to-massive AgNPs" amplification effect to improve sensitivity. The employment of ICP-MS detection and MBs not only simplified the experimental operation but also greatly enhanced the resistance of the method to the complicated matrix. The method can be used to simultaneously detect as few as 50 SMMC-7721 and A549 cancer cells in serum within 1 h with a recovery of 93-108% and a relative standard deviation (RSD, n = 5) < 5%. The method has notable advantages such as high sensitivity, excellent stability, high throughput, shorter analysis time, and strong resistibility to the complex matrix. Especially, the method can also be used to detect various cancer cells via altering aptamers and designing appropriate link/signal probes according to the target cells. The success of this study offers a potential approach for the high-throughput and rapid screening of cancer cells in clinical early diagnosis of cancer.

Efficacy of remote limb ischemic conditioning on poststroke cognitive impairment.

The impact of remote limb ischemic conditioning on poststroke cognitive impairment was evaluated with 104 first-time patients of noncardiac ischemic stroke. During the acute phase the patients were randomized into control and remote limb ischemic conditioning groups. Both groups received standard treatment, while the remote limb ischemic conditioning group received additional remote limb ischemic conditioning treatment for 6 months. All participants underwent neuropsychological evaluation, transcranial Doppler detection, P300 event-related potential and brachial-ankle pulse wave velocity measurements, and determination of serum intercellular adhesion molecule-1 and endothelin-1 levels both at admission and 6 months poststroke. The number of cases with poststroke cognitive impairment in each group was evaluated 6 months poststroke. No statistically significant difference was found in demographic data or baseline detection indices at admission between the two groups. However, at 6 months poststroke, the remote limb ischemic conditioning group had significantly higher total Montreal Cognitive Assessment score and its domains of visuospatial and executive functioning and attention scores, significantly lower activity of daily living scale score, shorter P300 latency, and higher amplitude compared with the control group. Moreover, the middle cerebral artery, average blood flow velocity was significantly higher, while the middle cerebral artery-pulsation index, basilar artery pulsation index, and the levels of brachial-ankle pulse wave velocity, intercellular adhesion molecule-1, and endothelin-1 were significantly lower in the remote limb ischemic conditioning group compared with the control group. These results demonstrate that remote limb ischemic conditioning causes a significant improvement in cognitive domains, such as visuospatial and executive functioning and attention, and is therefore linked with reduced incidence of poststroke cognitive impairment.

No Structure-Switching Required: A Generalizable Exonuclease-Mediated Aptamer-Based Assay for Small-Molecule Detection.

The binding of small molecules to double-stranded DNA can modulate its susceptibility to digestion by exonucleases. Here, we show that the digestion of aptamers by exonuclease III can likewise be inhibited upon binding of small-molecule targets and exploit this finding for the first time to achieve sensitive, label-free small-molecule detection. This approach does not require any sequence engineering and employs prefolded aptamers which have higher target-binding affinities than structure-switching aptamers widely used in current small-molecule detecting assays. We first use a dehydroisoandrosterone-3-sulfate-binding aptamer to show that target binding halts exonuclease III digestion four bases prior to the binding site. This leaves behind a double-stranded product that retains strong target affinity, whereas digestion of nontarget-bound aptamer produces a single-stranded product incapable of target binding. Exonuclease I efficiently eliminates these single-stranded products but is unable to digest the target-bound double-stranded product. The remaining products can be fluorescently quantified with SYBR Gold to determine target concentrations. We demonstrate that this dual-exonuclease-mediated approach can be broadly applied to other aptamers with differing secondary structures to achieve sensitive detection of various targets, even in biological matrices. Importantly, each aptamer digestion product has a unique sequence, enabling the creation of multiplex assays, and we successfully demonstrate simultaneous detection of cocaine and ATP in a single microliter volume sample in 25 min via sequence-specific molecular beacons. Due to the generality and simplicity of this assay, we believe that different DNA signal-reporting or amplification strategies can be adopted into our assay for target detection in diverse analytical contexts.

Exonuclease-assisted multicolor aptasensor for visual detection of ochratoxin A based on G-quadruplex-hemin DNAzyme-mediated etching of gold nanorod.

An exonuclease-assisted multicolor aptasensor was developed for the visual detection of ochratoxin A (OTA). It is based on the etching of gold nanorods (AuNRs) mediated by a G-quadruplex-hemin DNAzyme. A DNA sequence (AG4-OTA) was designed that comprises a hemin aptamer and an OTA aptamer. OTA binds to AG4-OTA to form an antiparallel G-quadruplex, which halts its digestion by exonuclease I (Exo I) from the 3'-end of AG4-OTA. Thus, the retained hemin aptamer can bind to hemin to form a G-quadruplex-hemin DNAzyme. This DNAzyme has peroxidase-like activity that catalyzes the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by H2O2 to produce its diimine derivative (TMB2+) in acidic solution. TMB2+ can etch the AuNRs by oxidizing Au(0) into Au(I). This results in the generation of rainbow-like colors and provides a multicolor platform for the visual detection of OTA. The assay is based on the use of a single isolated aptamer and possesses obvious advantages such as multi-color visual inspection, relatively high sensitivity and accuracy. It can be used to detect as little as 30 nM concentrations of OTA by visual observation and even 10 nM concentrations by spectrophotometry. The method was successfully applied to the determination of OTA in spiked beer where it gave recoveries of 101-108%, with a relative standard deviation (RSD, n = 5) of <5%. Graphical abstract Schematic of an exonuclease-assisted multicolor bioassay based on the G-quadruplex-hemin DNAzyme-mediated etching of gold nanorods (AuNRs). It enables visual detection of ochratoxin A (OTA) with a detection limit of 30 nM.

Simultaneous detection of zinc dimethyldithiocarbamate and zinc ethylenebisdithiocarbamate in cabbage leaves by capillary electrophoresis with inductively coupled plasma mass spectrometry.

We report a simple and highly sensitive method for the simultaneous detection of trace zinc dimethyldithiocarbamate and zinc ethylenebisdithiocarbamate by capillary electrophoresis with inductively coupled plasma mass spectrometry. Zinc dimethyldithiocarbamate and zinc ethylenebisdithiocarbamate were chelated with trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid to form a macromolecule complex. Then, these two compounds were separated by α-cyclodextrin-modified capillary electrophoresis within 12 min at a separation voltage of 15 kV and measured by inductively coupled plasma mass spectrometry. The developed method is sensitive with detection limit of 1.9 and 3.0 ng Zn/mL for zinc dimethyldithiocarbamate and zinc ethylenebisdithiocarbamate, respectively. By means of ultrasound-assisted extraction methods, zinc dimethyldithiocarbamate and zinc ethylenebisdithiocarbamate spiked into cabbage leaves were successfully extracted and determined with a relative standard deviation (n = 5) ≤ 6% and a recovery of 95-107%.

Rapid Analysis of Seven Polyamines in Nephotettix cincticeps by Using Ultra-Performance Liquid Chromatography-Triple Quadrupole Mass Spectrometry.

A fast, simple, and sensitive method for the simultaneous determination of seven polyamines in Nephotettix cincticeps was developed based on ultra-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-3Q-MS) together with liquid phase extraction. Polyamines in insect samples were extracted with HClO4 solution and then were separated and detected by UPLC-3Q-MS, which was equipped with a hydrophilic interaction liquid chromatography column, within 5 min without any derivatization procedure. The method has been successfully used to detect 7 polyamines in healthy and difluormethylornithine-treated adults of Nephotettix cincticeps with a method limit of detection and the method limit of quantitation of 24-139 pg/mg and 82-464 pg/mg, respectively, an intraday and interday relative standard deviation (RSD, n = 5) of 1.97-6.00% and 2.08-5.92% respectively, and a recovery of 86-115%. The success of this study provided a reliable method for the rapid and high-throughput detection of polyamines in the insect sample.

A microfluidic chip-based fluorescent biosensor for the sensitive and specific detection of label-free single-base mismatch via magnetic beads-based "sandwich" hybridization strategy.

A novel microfluidic chip-based fluorescent DNA biosensor, which utilized the electrophoretic driving mode and magnetic beads-based "sandwich" hybridization strategy, was developed for the sensitive and ultra-specific detection of single-base mismatch DNA in this study. In comparison with previous biosensors, the proposed DNA biosensor has much more robust resistibility to the complex matrix of real saliva and serum samples, shorter analysis time, and much higher discrimination ability for the detection of single-base mismatch. These features, as well as its easiness of fabrication, operation convenience, stability, better reusability, and low cost, make it a promising alternative to the SNPs genotyping/detection in clinical diagnosis. By using the biosensor, we have successfully determined oral cancer-related DNA in saliva and serum samples without sample labeling and any preseparation or dilution with a detection limit of 5.6 × 10(-11) M, a RSD (n = 5) < 5% and a discrimination factor of 3.58-4.54 for one-base mismatch.

A multicolor immunosensor for the visual detection of six sulfonamides based on manganese dioxide nanosheet-mediated etching of gold nanobipyramids.

In reality, various sulfonamides (SAs) were alternately used in animal husbandry to avoid generating drug resistance. Thus, it is crucial to develop simple and high-throughput methods for detecting multiple or groups of SAs to realize rapid screening of total SAs residues in foods. We herein developed a sensitive and efficient MnO2 nanosheets-mediated etching of gold nanobipyramids (AuNBPs), which can generate more vivid color changes, and further fabricated a high-throughput multicolor immunosensor for the visual screening/semi-quantitative detection of 6 different SAs including sulfamethazine (SMZ), sulfamethoxydiazine (SMD), sulfisomidine (SIM), sulfamerazine (SMR), sulfamonomethoxine (SMM) and sulfaquinoxaline (SQ) by using AuNBPs as signal and broad-specificity anti-SAs antibody as a bio-receptor. The immunosensor displays more vivid color changes, and has a lower visual detection limit and excellent specificity. It can be applied to detect as little as 1.0 ng/mL of SMZ, SMD, SMR and 2.0 ng/mL of SIM, SMM, SQ by bare eye observation, and 0.2 ng/mL of above 6 SAs by UV-visible spectrophotometry. The visual detection limit of the immunosensor is much lower than the maximum residue limit of total SAs (100 µg/kg) in edible tissues. The immunosensor was successfully applied to detect SMZ, SMD, SIM, SMR, SMM and SQ in milk with a recovery of 84%-106% and a RSD (n = 5) < 8%. The success of this study provided a promising assay for the on-site rapid screening of SMZ, SMD, SIM, SMR, SMM and SQ in food by bare eye observation. Importantly, the immunosensor may be expended as a general method for the visual screening/semi-quantitative detection of the group of other antibiotics by using the corresponding broad-specificity antibody as a bio-receptor.

Identification of risk and prognostic factors for intrahepatic vascular invasion in patients with hepatocellular carcinoma: a population-based study.

Background: The aim of this study was to develop nomograms to predict the risk of intrahepatic vascular invasion (IVI) of hepatocellular carcinoma (HCC) patients and estimate the overall survival (OS) and cancer-specific survival (CSS) of HCC patients with IVI. Methods: The Surveillance, Epidemiology, and End Results (SEER) database was used to identify patients with HCC from 2010 to 2015. Ultimately, 1,287 HCC patients with IVI were included in this study and randomly divided into training (n=901) and validation (n=386) cohorts. Multivariate logistic regression analysis and multivariate Cox proportional hazards regression analysis were performed to construct nomograms to visually quantify the risk of IVI in patients with HCC and predict the prognosis. The prediction effect of nomograms was evaluated using Harrell's concordance index (C-index), receiver operating characteristic (ROC) curve, calibration plots, and decision curve analysis (DCA), respectively. Results: The C-index of the nomogram for risk prediction was 0.730. The C-indices based on the nomogram were 0.762 [95% confidence interval (CI): 0.745-0.779] and 0.770 (95% CI: 0.753-0.787) for OS and CSS prediction in the training cohort, respectively. In the validation cohort, the C-indices were 0.779 (95% CI: 0.752-0.806) and 0.795 (95% CI: 0.768-0.822) for OS prediction and CSS prediction, respectively. Overall, the ROC curve, calibration plots, and DCA indicated the good performance of nomograms. Conclusions: We identified the relevant risk and prognostic factors for IVI in patients with HCC. The nomograms performed well on validation and may help to facilitate clinical decision-making.

Is hepatic resection always a better choice than radiofrequency ablation for solitary hepatocellular carcinoma regardless of age and tumor size?

In this study, we aimed to compare survival outcomes after receiving radiofrequency ablation (RFA) and hepatic resection (HR) for solitary hepatocellular carcinoma (HCC) with stratification by tumor size and age. A retrospective cohort was obtained from the Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2015. Patients were grouped by tumor size (0-2, 2-5, and > 5 cm) and age (>65 and ≤65). Overall survival (OS) and disease-specific survival (DSS) were assessed. For patients >65 with tumors measuring 0-2 and 2-5 cm, the HR group had better OS and DSS compared with the RFA group. For patients >65 with tumors > 5 cm, OS and DSS did not differ significantly between the RFA and HR groups (p = 0.262 and p = 0.129, respectively). For patients ≤65, the HR group had better OS and DSS compared with the RFA group regardless of tumor size. For patients with resectable solitary HCC, regardless of age, HR is the better choice not only for tumors ≤ 2 cm, but also for tumors 2-5 cm. For resectable solitary HCC with tumors ＞5 cm, HR is the better choice for patients ≤65 but for patients >65, the issue of treatment choice needs to be further studied.

Genome-wide identification and expression analysis of the HVA22 gene family in cotton and functional analysis of GhHVA22E1D in drought and salt tolerance.

The HVA22 family of genes, induced by abscisic acid and stress, encodes a class of stress response proteins with a conserved TB2/DP1/HVA22 domain that are unique among eukaryotes. Previous studies have shown that HVA22s play an important role in plant responses to abiotic stresses. In the present study, 34, 32, 16, and 17 HVA22s were identified in G. barbadense, G. hirsutum, G. arboreum, and G. raimondii, respectively. These HVA22 genes were classified into nine subgroups, randomly distributed on the chromosomes. Synteny analysis showed that the amplification of the HVA22s were mainly due to segmental duplication or whole genome replication (WGD). Most HVA22s promoter sequences contain a large number of drought response elements (MYB), defense and stress response elements (TC-rich repeats), and hormone response elements (ABRE, ERE, SARE, etc.), suggesting that HVA22s may respond to adversity stresses. Expression profiling demonstrated that most GhHVA22s showed a constitutive expression pattern in G. hirsutum and could respond to abiotic stresses such as salt, drought, and low temperature. Overexpression of GhHVA22E1D (GH_D07G0564) in Arabidopsis thaliana enhances salt and drought tolerance in Arabidopsis. Virus-induced gene silencing of GhHVA22E1D reduced salt and drought tolerance in cotton. This indicates that GhHVA22E1D plays an active role in the plant response to salt stress and drought stress. GhHVA22E1D may act in plant response to adversity by altering the antioxidant capacity of plants. This study provides valuable information for the functional genomic study of the HVA22 gene family in cotton. It also provides a reference for further elucidation of the functional studies of HVA22 in plant resistance to abiotic stress response.

Colorimetric aptasensor for sensitive detection of quinclorac based on exonuclease III-assisted cyclic release of phosphorodiamidate morpholino oligomer mimic enzyme strategy.

Here, a colorimetric aptasensor was constructed for sensitively detecting quinclorac (QNC), a common herbicide. The aptasensor involved a novel amplification strategy and a classical strand displacement strategy. The amplification strategy, termed exonuclease III (Exo III)-assisted cyclic release of phosphorodiamidate morpholino oligomer (PMO) mimic enzyme strategy, was developed based on two new findings on PMO: 1) DNA hybridized with PMO could resist Exo III digestion; 2) a designed G-rich PMO (named P2) could bind to hemin to form a G-quadruplex PMOzyme with peroxidase-like activity. In this strategy, a designed DNA-PMO duplex (D1-P1) completely hybridized with DNA2 (D2) in the other designed DNA-PMO duplex (D2-P2) to trigger D2 degradation by Exo III and cyclic release of P2. After that, the hemin-binding P2 catalyzed colorless tetra-methyl benzidine (TMB) to blue TMB+. The cycle process was performed at high Exo III concentrations without strict control and with constant background signals. In that case, the developed strategy was sensitive, efficient, easy to operate, reliable, and ultralow background. Meanwhile, a QNC aptamer was used to develop the strand displacement strategy based on magnetic beads. The colorimetric aptasensor was sensitive and selective for QNC detection with a detection limit of 7.1 ng mL-1. It was successfully applied to detect QNC in soil and river water with good recovery rates (92-98%) and a relative standard deviation (n = 3) <5%. The success of this study could provide a general reference strategy for developing sensitive aptasensors and other nucleic acid-related sensors.

Paper-based multicolor sensor for on-site quantitative detection of 2,4-dichlorophenoxyacetic acid based on alkaline phosphatase-mediated gold nanobipyramids growth and colorimeter-assisted method for quantifying color.

On-site quantitative analysis of pesticides is important for food safety. Colorimetric gold nanobipyramids (AuNBPs) sensors are powerful methods for on-site detection. However, a single quantitative method and the instability of AuNBPs in solution limit the practicability of those sensors. Here, a paper-based multicolor AuNBPs sensor involved a colorimeter-assisted method for quantifying color was developed for quantitative detection of 2,4-dichlorophenoxyacetic acid (2,4-D), a common herbicide. The novelty of this study lies in developing a general paper-based quantitative on-site method (PQOM) for colorimetric AuNBPs sensors. Firstly, a paper-based analytical device (PAD) consisting of a nylon membrane, absorbent cotton layers, and two acrylic plates was fabricated to deposit AuNBPs. We demonstrated the PAD could improve the stability of AuNBPs and the detection sensitivity of AuNBPs sensors. Then, a handheld colorimeter was first used to quantify the color change of AuNBPs on the PAD based on the CIELab color space. Finally, as proof of concept, the PQOM was successfully employed to quantify 2,4-D by combining with an alkaline phosphatase-mediated AuNBPs growth method. In this method, 2,4-D specifically inhibited alkaline phosphatase activity to suppress the generation of l-ascorbic acid, thereby mediating AuNBPs growth. The developed sensor exhibited seven 2,4-D concentration-related colors and detected as low as 50 ng mL-1 2,4-D by naked-eye observation and 18 ng mL-1 2,4-D by a colorimeter. It was applied to detect 2,4-D in the spiked rice and apple samples with good recovery rates (91.8-112.0%) and a relative standard deviation (n = 5) < 5%. The success of this study provides a sensing platform for quantifying 2,4-D on site.