A "turn-on" fluorescence resonance energy transfer aptasensor based on carbon dots and gold nanoparticles for 17ß-estradiol detection in sea salt.

17ß-estradiol is abused in the food industry. Excess 17ß-estradiol can disturb the endocrine system or cause many diseases including obesity, diabetes, cardiac-cerebral vascular disease, and cancers in the human body. A "turn-on" fluorescence resonance energy transfer (FRET) aptasensor based on carbon dots (CDs) and gold nanoparticles (AuNPs) was developed for the detection of 17ß-estradiol. A thiol-modified oligonucleotide was conjugated to AuNPs and amino modified oligonucleotide was linked to CDs. The 17ß-estradiol aptamer was hybridized with the two oligonucleotides, shortening the distance between CDs and AuNPs. With 360 nm UV light excitation, FRET occurred between CDs and AuNPs. The system was "turn-off". When 17ß-estradiol was detected, the aptamer specifically bound to 17ß-estradiol, and the FRET system was destroyed, leading to the "turn-on" phenomenon. The fluorescence intensity recovery was detected in the concentration range of 400 pM to 5.5 µM. The limit of detection (LOD) was 245 pM. The FRET aptasensor demonstrated good selectivity for 17ß-estradiol detection. Reasonable spiked recoveries were obtained in sea salt samples. It showed the potential for estrogen detection in food safety and environmental applications.

High prevalence of Helicobacter pylori mixed infections identified by multilocus sequence typing in Ningbo, China.

This study used multilocus sequence typing (MLST) to investigate the prevalence of Helicobacter pylori (H. pylori) mixed infections and H. pylori mixed infections involving unrelated strains; and determined the phylogeographic groups of H. pylori recovered from patients in Ningbo, China. A total of 156 H. pylori isolates were obtained from a convenience sample of 33 patients with culture-positive H. pylori infection. MLST was used to classify 150 H. pylori clinical isolates and 12 methodological control strains (6 clinical isolates and 6 strains of American Type Culture Collection H. pylori) into 43 and 12 sequence types (STs), respectively. In this study, 246 new alleles and 53 new STs were identified by MLST. The prevalence of mixed infections was 41% (11/27). The prevalence of H. pylori mixed infections involving unrelated strains was 46% (5/11) and the prevalence of H. pylori mixed infections involving completely unrelated strains (strains with all 7 housekeeping genes different) was 36% (4/11). A phylogenetic tree was created to determine the evolutionary relationships between different strains. The STs in this study were clustered within the hspEAsia subgroup (98%) and hpEurope group (2%). H. pylori mixed infections were common in Ningbo, China. The H. pylori isolates belonging to the hpEurope group were recovered from three different biopsy samples in a native Chinese patient. Most of H. pylori strains colonizing the antrum, corpus, and duodenum bulb were homologous.

Echinacoside exerts its protective effects in a type 2 diabetes mellitus injury model via the AKT pathway.

Echinacoside (ECH) is the main compound of Cistanche deserticola, which possesses antioxidant, antitumor, antifatigue, and anti-inflammatory properties. The present study investigated the protective effects of echinacoside on type 2 diabetes mellitus (T2DM)-induced injury in T2DM injury db/db mice model and insulin-resistant LO2 cell model. The results demonstrated that ECH probably alleviated T2DM-induced injury by mediating the AKT pathway, which provided a new direction for the treatment of T2DM-induced injury.

Activation of angiotensin II type 2 receptor attenuates lung injury of collagen-induced arthritis by alleviating endothelial cell injury and promoting Ly6Clo monocyte transition.

As one of the most frequent extra-articular manifestations of rheumatoid arthritis (RA), interstitial lung disease (ILD) is still challenging due to unrevealed pathophysiological mechanism. To address this question, in the present study, we used the classical collagen-induced arthritis (CIA) mouse model to determine the related-immune mechanism of lung injury and possible pharmacological treatment for RA-ILD. At the peak of arthritis, we found CIA mice developed apparent lung injury, characterized by interstitial thickening, inflammatory cell infiltration, and lymphocyte follicle formation. Additionally, the endothelial injury occurred as the number of endothelial cells (ECs) and their CD31 expression decreased. Along with those, monocytes, predominantly Ly6Chi monocytes with pro-inflammatory phenotype, were also increased. While in the remission period of arthritis, ECs gradually increased with retrieved CD31 expression, leading to decreased infiltrating monocytes, but boosted Ly6Clo population. Ly6Clo monocytes were prone to locate around damaged ECs, promoted ECs proliferation and vascular tube formation, and lessened the expression of adhesion molecules. In addition, we evaluated angiotensin II type 2 receptor (Agtr2), which has been demonstrated to be protective against lung injury, could be beneficial in RA-ILD. We found elevated Agtr2 in CIA lung tissue, and activation of Agtr2, within its specific agonist C21, alleviated the pulmonary inflammation in vivo, reduced ECs injury, and promoted monocytes conversion from Ly6Chi to Ly6Clo monocytes in vitro. Our data reveal a potential pathological mechanism of RA-ILD that involves ECs damage and inflammatory monocytes infiltration and provide a potential drug target, Agtr2, for RA-ILD treatment.

Ultrasound-Guided Oblique Sagittal Anterior Quadratus Lumborum Block in Total Hip Arthroplasty: A Randomized Controlled Trial.

BACKGROUND: The anterior quadratus lumborum block (QLB) is gaining popularity in total hip arthroplasty (THA) surgeries for postoperative pain management and this technique rarely results in lower limb muscle weakness. However, no studies have described the range of its blockade. OBJECTIVES: The aim of the study was to confirm the range of cold temperature sensory blockades, observe the opioid consumption after THA surgery, assess the pain of the patients, and assess the safety of this technique. STUDY DESIGN: Randomized controlled study. SETTING: Taizhou Hospital of Zhejiang Province. METHODS: Patients who underwent primary THAs were randomized to take an oblique sagittal anterior QLB with 30 mL of 0.375% ropivacaine (QLB+G group) or with 30 mL of 0.9% saline (G group). The main purpose of the study was to confirm the range of cold hypoesthesia. The other aim included the average blood pressure, heart rate, surgical pleth index, and bispectral index values fluctuation during the intraoperative period of expanding the medullary cavity, the sufentanil, and remifentanil consumption during the operation, the amount of time the patients stayed in the Postanesthesia Care Unit, the 8 hours, 16 hours, and 24 hours total dosage of oxycodone, the resting and exercise Visual Analog Scale (VAS) pain scores at 8 hours, 16 hours, and 24 hours after surgery, postoperative adverse events, and safety. RESULTS: The QLB+G group identified areas  of cold hypoesthesia after the block, but there were no areas of cold hypoesthesia in the G group. The consumption of oxycodone in the 8 hours, 16 hours, and 24 hours after the surgery and the consumption of sufentanil during the surgery were significantly smaller in the QLB+G group (P < 0.05). The QLB+G group have lower pain scores at the resting 8 hours and exercise 8 hours, 16 hours, and 24 hours after the surgery (P < 0.05). The 2 groups have comparable safety in the study. LIMITATIONS: This study only tested the areas of cold hypoesthesia after the QLB, but not tested the area of sensory loss. Using ice to test for hypoesthesia is subjective, and may not reflect the actual area of the block. CONCLUSIONS: Ultrasound-guided oblique sagittal anterior QLB can reduce the analgesics required after and during THA and the postoperative VAS pain scores, but it rarely affects muscle strength.

Acute glycemic variability and risk of mortality in patients with sepsis: a meta-analysis.

BACKGROUND: Acute glycemic variability (GV) has been correlated with the severity of sepsis. The aim of the study was to evaluate the potential association between acute GV and mortality risk in patients with sepsis. METHODS: Cohort studies comparing the risk of death within 3 months between septic patients with higher versus lower acute GV were retrieved by systematic search of Medline, Embase, Web of Science, Wanfang and CNKI databases. We used a random-effect model to pool the data by incorporating the between-study heterogeneity. Sensitivity analyses were performed to evaluate the stability of the findings. RESULTS: Ten studies including 4296 patients were available for the meta-analysis. Pooled results showed that septic patients with higher acute GV had significantly increased mortality risk compared to those with lower acute GV, as evidenced by results using different parameters including standard deviation of blood glucose (SDBG, risk ratio [RR]: 1.74, 95% confidence interval [CI] 1.36-2.24, p < 0.001; I2 = 0%), coefficient of variation of blood glucose (RR: 1.91, 95% CI 1.57-2.31, p < 0.001; I2 = 0%), mean amplitude of glycemic excursion (RR: 1.81. 95% CI 1.36-2.40, p < 0.001; I2 = 0%), and glycemic lability index (RR: 2.52, 95% CI 1.72-3.68, p < 0.001; I2 = 0%). Sensitivity analyses by excluding one study at a time did not significantly affect the results (p all < 0.05). CONCLUSIONS: Higher acute GV may be a predictor of mortality risk in patients with sepsis.

iArm: Design an Educational Robotic Arm Kit for Inspiring Students' Computational Thinking.

Educational robotics is an effective carrier of information technology education, making its way into classrooms. However, the design of the educational robotic arm kit and the study on the effect of robotic arms on students' thinking literacy remain to be completed. In this paper, iArm, a 6-DOF robotic arm consisting of a drive chassis, an arm body, and end tools, is presented. Its auxiliary modules, including the vision module and conveyor belt, and the curriculum targeting students' computational thinking are also developed to refine the current educational robotic arm kit. Furthermore, to explore the effectiveness of the iArm kit, thirteen high school students participated in the semester-long curriculum, completed assigned projects, and filled out the pre-test and post-test scales. By formative and summative evaluation, the result shows that the iArm kit effectively enhanced students' computational thinking.

[Development of a colloidal gold based immunochromatographic strip for 8-OHdG detection].

8-hydroxy-2'-deoxyguanosine (8-OHdG) is a sensitive and stable biomarker for evaluating DNA oxidative damage. A rapid and sensitive colloidal gold immunochromatographic strip was developed for 8-OHdG detection by a competitive method. The sample pad (glass cellulose film), bonding pad (glass cellulose film), nitrocellulose film and absorbent pad were pasted on the polyvinyl chloride (PVC) base plate to construct the test strip. Colloidal gold (AuNPs) was prepared by the reduction of chloroauric acid with sodium citrate. 8-OHdG antibody (Ab) was coated on the outer layer of AuNPs to form Ab@AuNPs as a probe. Bovine serum albumin (BSA) and 8-OHdG were conjugated with carbodiimide hydrochloride to prepare an artificial antigen, which was used as the coating antigen of detection line. Goat anti mouse polyclonal antibody IgG was used as the coating antibody of control line. The experimental parameters were optimized including the type of nitrocellulose membrane, the formula of loading solution, and the spraying amount of gold labeled antibody. The results showed that the appropriate nitrocellulose membrane was CN 95. The optimal loading solution included BSA (1%), Tween-20 (3%), sucrose (3%) and NaCl (0.9%). The optimal spraying amount of gold labeled antibody was 4 µL. 8-OHdG can be detected by the strip under visible light, and the level of 8-OHdG in urine can be preliminarily determined by comparing the color intensity of T line and C line. The 8-OHdG concentration in urine was further calculated by the gray value of T line and the threshold of detection was 2.55 µg/L. This colloidal gold immunochromatographic strip is simple, rapid and specific for detecting 8-OHdG in human urine to preliminarily evaluate the human status.

Clinical Study on the Relationship between the SNP rs8192675 (C/C) Site of SLC2A2 Gene and the Hypoglycemic Effect of Metformin in Type 2 Diabetes.

This study investigates the correlation between the gene polymorphism of rs8192675 (C/C) locus of SLC2A2 in patients with type 2 diabetes (T2DM) and the efficacy of metformin. For this purpose, we have selected 110 T2DM patients (T2DM group) and 110 healthy people (control group) who were treated in our hospital from January 2019 to January 2020 as the research subjects. PCR-restriction fragment length polymorphism (PCR-RFLP) method detects the distribution frequency of gene polymorphism. The patients in the T2DM group were treated with metformin and followed up for 90 days to analyze the relationship between the efficacy of metformin and the SLC2A2 gene polymorphism. The genotypes of SLC2A2 rs8192675 in the control group and in the T2DM group conformed to the Hardy-Weinberg equilibrium law. Compared with the control group, the CT type and the CC type at rs8192675 in the T2DM group were significantly higher (P < 0.05). For rs8192675, there was no significant difference in TT, CT, CC FPG, 2hPBG, and HbA1c levels before treatment (P > 0.05); after metformin treatment, the reduction in FPG, 2hPBG, and HbA1c in CC patients was lower than that of TT and CT patients (P < 0.05). SLC2A2 gene polymorphism site rs8192675 CC type T2DM patients are sensitive to metformin and have a better hypoglycemic effect.

A Sensitive FRET Biosensor Based on Carbon Dots-Modified Nanoporous Membrane for 8-hydroxy-2'-Deoxyguanosine (8-OHdG) Detection with Au@ZIF-8 Nanoparticles as Signal Quenchers.

A sensitive fluorescence resonance energy transfer (FRET) biosensor is proposed to detect 8-hydroxy-2'-deoxyguanosine (8-OHdG), which is a typical DNA oxidation damage product excreted in human urine. The FRET biosensor was based on carbon dots (CDs)-modified nanoporous alumina membrane with CDs as fluorescence donors. Gold nanoparticles were encapsulated in zeolitic imidazolate framework-8 to form Au@ZIF-8 nanoparticles as signal quenchers. CDs and Au@ZIF-8 nanoparticles were biofunctionalized by 8-OHdG antibody. The capture of 8-OHdG on the membrane substrates can bring Au@ZIF-8 nanoparticles closely to CDs. With 350 nm excitation, the fluorescence of CDs was quenched by Au@ZIF-8 nanoparticles and FRET effect occurred. The quenching efficiency was analyzed. The limit of detection (LOD) was 0.31 nM. Interference experiments of the FRET biosensor showed good specificity for 8-OHdG detection. The biosensor could detect urinary 8-OHdG sensitively and selectively with simple sample pretreatment processes. It shows applicability for detecting biomarkers of DNA damage in urine or other biological fluids.

Carbon tetrachloride (CCl4) accelerated development of non-alcoholic fatty liver disease (NAFLD)/steatohepatitis (NASH) in MS-NASH mice fed western diet supplemented with fructose (WDF).

BACKGROUND: Multiple murine models of nonalcoholic fatty liver disease/steatohepatitis (NAFLD/NASH) have been established by using obesogenic diets and/or chemical induction. MS-NASH mouse (formally FATZO) is a spontaneously developed dysmetabolic strain that can progress from hepatosteatosis to moderate fibrosis when fed a western diet supplemented with 5% fructose (WDF). This study aimed to use carbon tetrachloride (CCl4) to accelerate and aggravate progression of NAFLD/NASH in MS-NASH mouse. METHODS: Male MS-NASH mice at 8 weeks of age were fed WDF for the entire study. Starting at 16 weeks of age, CCl4 was intraperitoneally administered twice weekly at a dose of 0.2 mL/kg for 3 weeks or 0.08 mL/kg for 8 weeks. Obeticholic acid (OCA, 30 mg/kg, QD) was administered in both MS-NASH and C57Bl/6 mice fed WDF and treated with CCl4 (0.08 mL/kg). RESULTS: WDF enhanced obesity and hepatosteatosis, as well as induced moderate fibrosis in MS-NASH mice similar to previous reports. Administration of CCl4 accelerated liver fibrosis with increased bridging and liver hydroxyproline contents, but had no significant impact on liver steatosis and lipid contents. High dose CCl4 caused high mortality and dramatic elevation of ALT and ASL, while low dose CCl4 resulted in a moderate elevation of ALT and AST with low mortality. Compared to C57BI/6 mice with WDF and CCl4 (0.08 mL/kg), MS-NASH mice had more prominent hepatosteatosis and fibrosis. OCA treatment significantly lowered liver triglycerides, steatosis and fibrosis in both MS-NASH and C57Bl/6 mice fed WDF with CCl4 treatment. CONCLUSIONS: CCl4 reduced induction time and exacerbated liver fibrosis in MS-NASH mice on WDF, proving a superior NASH model with more prominent liver pathology, which has been used favorably in pharmaceutical industry for testing novel NASH therapeutics.

Synergistic effects of Lactobacillus rhamnosus culture supernatant and bone marrow mesenchymal stem cells on the development of alcoholic steatohepatitis in mice.

The gut microbiota has been shown to play an important role in chronic liver disease. It has been found that both Lactobacillus rhamnosus and its culture supernatant have the potential to mitigate alcoholic steatohepatitis. However, the exact mechanism is still not fully understood. Bone marrow mesenchymal stem cells have immunosuppressive effects with few side effects. The synergistic effect between Lactobacillus rhamnosus culture supernatant and bone marrow mesenchymal stem cells (BMMSCs) deserves further observation. In this study, a mouse model of chronic alcoholic hepatitis was established by eight weeks of Lieber-DeCarli liquid diet feeding; and LGG-s, BMMSCs or a combination of the two were used to explore a new therapeutic method for alcoholic liver disease and to study the mechanism. The results showed that the combined LGG-s and BMMSC treatment might have a synergistic effect and could improve the symptoms of alcoholic hepatitis by regulating inflammation, autophagy and lymphocyte subsets through the PI3k/NF-kB and PI3K/mTOR pathways. With the treatment, the autophagy rate accelerated, and alcohol-induced natural killer B (NKB) cell and follicular helper T (TFH) cell numbers decreased. These findings suggest that the development of alcoholic hepatitis may occur via PI3K/NF-kB and PI3K/mTOR pathway overactivation as well as through NKB and TFH cell imbalances. Moreover, LGG-s and BMMSCs can regulate these factors and alleviate the disease.

Carbon Dots-Modified Nanoporous Membrane and Fe3O4@Au Magnet Nanocomposites-Based FRET Assay for Ultrasensitive Histamine Detection.

Histamine can be formed by enzymatic decarbonylation of histidine, which is an important indicator of seafood quality. A rapid and sensitive assay method is necessary for histamine monitoring. A fluorescence resonance energy transfer (FRET) assay system based on a carbon dot (CD)-modified nanoporous alumina membrane and Fe3O4@Au magnet nanocomposites has been developed for histamine detection in mackerel fish. CDs immobilized on nanoporous alumina membranes were used as donors, which provided a fluorescence sensing substrate for histamine detection. Fe3O4@Au magnet nanocomposites can not only act as acceptors, but also concentrate histamine from fish samples to increase detection sensitivity. Histamine was detected by the fluorescence signal changes of CDs capturing histamine by an immune reaction. The fluorescence signals of CDs were quenched by Fe3O4@Au magnet nanocomposites via the FRET mechanism. With an increase of histamine, the fluorescence intensity decreased. By recording fluorescence spectra and calculating intensity change, histamine concentration can be determined with a limit of detection (LOD) of 70 pM. This assay system can be successfully applied for histamine determination in mackerel fish to monitor the fish spoilage process in different storage conditions. It shows the potential applications of CDs-modified nanoporous alumina membranes and Fe3O4@Au magnet nanocomposites-based biosensors in the food safety area.

Two HEPN domains dictate CRISPR RNA maturation and target cleavage in Cas13d.

Cas13d, the type VI-D CRISPR-Cas effector, is an RNA-guided ribonuclease that has been repurposed to edit RNA in a programmable manner. Here we report the detailed structural and functional analysis of the uncultured Ruminococcus sp. Cas13d (UrCas13d)-crRNA complex. Two hydrated Mg2+ ions aid in stabilizing the conformation of the crRNA repeat region. Sequestration of divalent metal ions does not alter pre-crRNA processing, but abolishes target cleavage by UrCas13d. Notably, the pre-crRNA processing is executed by the HEPN-2 domain. Furthermore, both the structure and sequence of the nucleotides U(-8)-C(-1) within the repeat region are indispensable for target cleavage, and are specifically recognized by UrCas13d. Moreover, correct base pairings within two separate spacer regions (an internal and a 3'-end region) are essential for target cleavage. These findings provide a framework for the development of Cas13d into a tool for a wide range of applications.

A carbon dot and gold nanoparticle-based fluorometric immunoassay for 8-hydroxy-2'-deoxyguanosine in oxidatively damaged DNA.

A method is described for the fluorometric determination of DNA containing oxidatively damaged product 8-hydroxy-2'-deoxyguanosine (DNA-8-OHdG). Carbon dots (CDs) were modified with glutaraldehyde for DNA conjugation, and antibody against 8-OHdG was immobilized on gold nanoparticles (AuNPs). The presence of DNA-8-OHdG can be linked to CDs by reaction of amino groups on DNA with glutaraldehyde. AuNPs were brought closely to CDs by specific immune reaction between 8-OHdG and antibody on AuNPs. Under 350 nm photoexcitation, the emission of CDs with a peak at 440 nm is quenched by the AuNPs and not restored. In the presence of DNA-8-OHdG, the measured fluorescence intensity decreases and quenching efficiency increases. The limit of detection is 700 pM, and the assay works in the 0.01 nM to 25 µM DNA-8-OHdG concentration range. The method is perceived to possess a good potential as a tool for detecting biomarkers for DNA damage due to oxidative stress. Graphical abstract A fluorometric immunoassay for detecting 8-hydroxy-2'-deoxyguanosine (8-OHdG) in oxidatively damaged DNA is reported. It is based on the use of carbon dots (CDs) and gold nanoparticles (AuNPs). Black wavy lines represent DNA. Yellow polygonal sharps represent 8-OHdG. Blue and pink balls represent CDs and AuNPs, respectively.

cGAS activation causes lupus-like autoimmune disorders in a TREX1 mutant mouse model.

TREX1 encodes a major cellular DNA exonuclease. Mutations of this gene in human cause cellular accumulation of DNA that triggers autoimmune diseases including Aicardi-Goutieres Syndrome (AGS) and systemic lupus erythematosus (SLE). We created a lupus mouse model by engineering a D18 N mutation in the Trex1 gene which inactivates the enzyme and has been found in human patients with lupus-like disorders. The Trex1D18N/D18N mice exhibited systemic inflammation that consistently recapitulates many characteristics of human AGS and SLE. Importantly, ablation of cGas gene in the Trex1D18N/D18N mice rescued the lethality and all detectable pathological phenotypes, including multi-organ inflammation, interferon stimulated gene induction, autoantibody production and aberrant T-cell activation. These results indicate that cGAS is a key mediator in the autoimmune disease associated with defective TREX1 function, providing additional insights into disease pathogenesis and guidance to the development of therapeutics for human systemic autoimmune disorders.

The MEK-ERK1/2 signaling pathway regulates hyaline cartilage formation and the redifferentiation of dedifferentiated chondrocytes in vitro.

The aim of this study was to investigate the role of the mitogen-activated protein kinase kinase-extracellular signal-regulated kinases 1/2 (MEK-ERK1/2) signaling pathway in chondrocyte differentiation and cartilage tissue construction in vitro. Chondrocytes were stimulated with rat serum (RS) and fetal bovine serum (FBS), and chondrocyte phenotypes were investigated microscopically. Chondrocyte proliferation was analyzed using fluorescence activated cell sorting (FACS) and the CCK8 method. Protein and mRNA expressions were assessed by western blot and RT-qPCR. Constructed cartilage tissues were examined by Safranin O-Fast Green FCF staining and immunofluorescence. In contrast to FBS, RS induced rapid dedifferentiation of chondrocytes and decreased type II collagen expression and proteoglycan synthesis. ERK1/2 and type I collagen expression increased during dedifferentiation and decreased during redifferentiation. Increased MEK-ERK1/2 pathway activity resulted in chondrocyte dedifferentiation, and inhibition of ERK1/2 by the inhibitor PD0325901 reversed dedifferentiation and led to redifferentiation. These data suggest strongly that inhibition of MEK-ERK1/2 activation prevents chondrocyte dedifferentiation and fibrocartilage formation.