Development and validation of a scoring system to predict esophagogastroduodenoscopy necessity.

OBJECTIVE: This study aimed to develop and validate a scoring system for predicting the need for esophagogastroduodenoscopy (EGD) in clinical practice to enhance accuracy and reduce misapplications. METHODS: From February 2021 to April 2022, outpatients scheduled for EGD at the Department of Gastroenterology in our hospital were recruited. Patients completed the system evaluation by providing clinical symptoms, relevant medical history, and endoscopic findings. Patients were randomly divided into the training and validation cohorts (at 2:1 ratio). The optimal algorithm was selected from five alternatives including a parallel test. Six physicians participated in a human-computer comparative validation. Sensitivity and negative likelihood ratio (-LR) were used as the primary indicators. RESULTS: Altogether 865 patients were enrolled, with 578 in the training cohort and 287 in the validation cohort. The scoring system comprised 21 variables, including age, 13 typical clinical symptoms, and seven medical history variables. The parallel test was selected as the final algorithm. Positive EGD findings were reported in 54.5% of the training cohort and 62.7% of the validation cohort. The scoring system demonstrated a sensitivity of 79.0% in the training cohort and 83.9% in the validation cohort, with -LR being 0.627 and 0.615, respectively. Compared to physicians, the scoring system exhibited higher sensitivity (84.0% vs 68.7%, P = 0.02) and a lower -LR (1.11 vs 2.41, P = 0.439). CONCLUSIONS: We developed a scoring system to predict the necessity of EGD using a parallel test algorithm, which was user-friendly and effective, as evidenced by single-center validation.

Enhanced Growth Inhibition and Apoptosis Induction in Human Colon Carcinoma HT-29 Cells of Soluble Longan Polysaccharides with a Covalent Chemical Selenylation.

The selenylated polysaccharides chemically belong to the organic Se-conjugated macromolecules and have recently been attracting more and more attention due to their potential to promote body health or prevent cancers. Longan (Dimocarpus longan L.), as a subtropical fruit, contains soluble and non-digestible polysaccharides that are regarded with health care functions in the body. In this study, the longan polysaccharides (LP) were obtained via enzyme-assisted water extraction, and then chemically selenylated using a reaction system composed of HNO3-Na2SeO3 to yield two selenylated products, namely, SeLP1 and SeLP2, with Se contents of 1.46 and 4.79 g/kg, respectively. The anti-cancer effects of the three polysaccharide samples (LP, SeLP1, and SeLP2) were thus investigated using the human colon cancer HT-29 cells as the cell model. The results showed that SeLP1 and SeLP2 were more able than LP to inhibit cell growth, alter cell morphology, cause mitochondrial membrane potential loss, increase intracellular reactive oxygen and [Ca2+]i levels, and induce apoptosis via regulating the eight apoptosis-related genes and proteins including Bax, caspases-3/-8/-9, CHOP, cytochrome c, DR5, and Bcl-2. It was thereby proven that the selenylated polysaccharides could induce cell apoptosis via activating the death receptor, mitochondrial-dependent, and ER stress pathways. Collectively, both SeLP1 and SeLP2 showed higher activities than LP in HT-29 cells, while SeLP2 was consistently more active than SeLP1 in exerting these assessed anti-cancer effects on the cells. In conclusion, this chemical selenylation covalently introduced Se into the polysaccharide molecules and caused an enhancement in their anti-cancer functions in the cells, while higher selenylation extent was beneficial to the activity enhancement of the selenylated products.

The anti-inflammatory effects of apigenin and genistein on the rat intestinal epithelial (IEC-6) cells with TNF-α stimulation in response to heat treatment.

The aims of the present study were to investigate the anti-inflammatory function of two flavonoids apigenin and genistein in rat intestinal epithelial (IEC-6) cells stimulated by tumor necrosis factor-alpha (TNF-α) and to clarify whether the heat treatment of the flavonoids might affect flavonoid activity. The flavonoids at lower dosage (e.g. 5 µmol/L) had no toxic effect but growth promotion on the cells. Meanwhile, the flavonoid pretreatment of the cells before TNF-α stimulation could maintain cellular morphology, decrease the production of prostaglandin E2 and two pro-inflammatory cytokines interleukin-1ß (IL-1ß) and IL-6, but increase the production of two anti-inflammatory cytokines IL-10 and transforming growth factor-ß. Additionally, the flavonoids could block off the nuclear translocation of nuclear factor-kappaB (NF-κB) p65, and suppress the expression of phosphorylated IκBα and p65 induced by TNF-α. Meanwhile, the NF-κB inhibitor BAY 11-7082 shared a similar function with the flavonoids to mediate the production of IL-6/IL-10. Furthermore, in silico analysis also declared that the flavonoids could interact with the IκBα-NF-κB complex at the binding pockets to yield the binding energies ranging from -31.7 to -34.0 kJ/mol. However, the heated flavonoids were consistently less effective than the unheated counterparts to perform these anti-inflammatory effects. It is thus proposed that both apigenin and genistein have anti-inflammatory potential to the TNF-α-stimulated IEC-6 cells by inactivating the NF-κB pathway, while heat treatment of the flavonoids caused a negative impact on these assessed anti-inflammatory effects.

The peroxidase-mimicking function of acetate and its application in single-enzyme-based glucose test paper.

Acetate ion was widely used in pH buffer to control pH environment. Here we firstly found that acetate ion had mimic peroxidase activity. Acetate ions are capable of catalyzing the decomposition of hydrogen peroxide and play a similar role to that of horseradish peroxidase (HRP). Acetate catalyzes the oxidation of tetramethylbenzidine (TMB) by H2O2, which is the product of the reaction of glucose and glucose oxidase. A colorimetric sensor for H2O2 and glucose was developed using acetate ions. The linear regression equation for H2O2 was A = 0.0029 C + 0.0530 (C (µmolL-1), R = 0.9978), and the detection limit was 3.0 µmolL-1, whereas that for glucose was A = 0.0021 C + 0.0709 (C (µmol L-1), R = 0.9977), and the detection limit was 4.0 µmol L-1. Moreover, the proposed method was successfully applied for the detection of H2O2 in human urine and glucose in human serum; thus, the proposed method could be used for the diagnosis of illness or disease. A single-enzyme-based glucose test paper was firstly prepared and tested for semi-quantitative analysis of glucose.

Highly exfoliated montmorillonite clay reinforced thermoplastic polyurethane elastomer: in situ preparation and efficient strengthening.

Highly exfoliated montmorillonite (MMT) clay reinforced thermoplastic polyurethane elastomers (TPUs) were prepared by an in situ solution polymerization method. By using small amount of 4,4'-methylenediphenyl diisocyanate (MDI) modified pristine clay (MDI-MMT) as fillers, the mechanical properties of TPUs were greatly improved. For example, with the addition of only 1.0 wt% of MDI-MMT, the resultant TPU/MDI-MMT nanocomposites showed approximately 36% increase in initial Young's modulus, 70% increase in tensile strength and 46% increase in ultimate elongation at break as compared with those of neat TPU. Detailed study showed that, owing to the strong covalent bonding between the MMT sheets and TPU matrix, MMT sheets were highly exfoliated during the polymerization process, and the highly exfoliated MMT sheets gave rise to the greatly improved mechanical properties and thermomechanical properties of TPU/MDI-MMT nanocomposites. The present work demonstrates that the in situ preparation of TPU/MDI-MMT nanocomposites by using MDI-MMT as fillers is a highly efficient method for reinforcing TPU.

Characterization of the Thermal Degradation of Vinegar and the Construction of an Identification Model for Chinese Geographical Indication Vinegars by the Py-GC-MS Technique.

The pyrolysis (Py)-GC-MS technique was first introduced for the identification of two kinds of Chinese geographical indication vinegars because its advantages are that it is a simple and convenient sample pretreatment and inlet method. Abundant Py information about vinegars was obtained using Py-GC-MS; 21 common peaks were selected. With the help of the classical partial least-squares (PLS) modeling method for data analysis, two identification models for Shanxi extra-aged (SX) and Zhenjiang (ZJ) vinegars were established, respectively. An N-reducing method was used to select the variables. The variables were reduced one at a time to build the PLS models with the lowest number of misjudgments. Both models had good recognition rates, identifying over 90% of samples correctly. Thus, combining Py-GC-MS and PLS could be regarded as an effective method for the identification of SX and ZJ vinegars.

[Study on the Identification of Geographical Indication Wuchang Rice Based on the Content of Inorganic Elements].

Wuchang rice is a geographical indication product in China. Due to its high quality and low production, the phenome- non of fake is more and more serious. An effective identification method of Wuchang rice is urgent needed, for the maintenance of its brand image and interest of consumers. Base on the content of inorganic elements which are analyzed by ICP-AES and ICP-MS in rice, the identification model of Wuchang rice is studied combining with principal component analysis (PCA), Fisher discrimination and artificial neural network (ANN) in this paper. The effect on the identification of samples is poor through PCA, while the samples from Wuchang area and other areas can be identified accurately through Fisher discrimination and ANN. The average accurate identification ratio of training and verification set through Fisher discrimination is 93.5%, while the average accurate identification ratio through ANN is 96.4%. The ability to identify of ANN is better than Fisher discrimination. Wuchang rice can be identified accurately through the result of this research which provides a technology for the protection of geographical indications of this product.

[Fast screening of the artificial dyes in wine by liquid chromatography/hybrid linear ion trap-orbitrap mass spectrometry].

A fast screening method was established for the simultaneous determination of 15 water-soluble artificial dyes in wine by liquid chromatography/hybrid linear ion trap orbitrap mass spectrometry (LC/LTQ-orbitrap MS) based on a self-established mass spectral database. The confirmations of these target dyes were processed by the accurate mass numbers, and the MS(2) spectra marching to the self-established mass spectral database. The dyes in wine were purified by an anion-exchange column and separated by a BEH Phenyl column, then identified and quantified by LTQ-orbitrap MS. The results showed that the method detection limits of the target compounds were ranged from 0.00040 to 0.18 mg/L, and the average recoveries of the 15 compounds spiked at three concentrations were in the range of 43.1% - 127% with the relative standard deviations less than 10%. The spiked sample had the matching scores higher than 98% to the second order mass spectra of the standard compounds in the database. The method is also suitable for screening the 15 dyes in wine without reference standards.

A geographical discrimination of Shanxi extra aged vinegars using polyalcohols as the discriminators.

A discrimination method based on polyalcohol determination was developed for authenticity of protected geographical indication (PGI) vinegars-Shanxi extra aged vinegar (SVs) in China. Six polyalcohols in vinegars including erythritol, arabitol, xylitol, inositol, mannitol, and sorbitol were selected as the PGI discriminators. GC/MS was used to analyze the polyalcohols in the SVs, Zhenjiang vinegars (ZVs), Kazuo aged vinegars (KVs), and other non-geographical indication protected vinegars (NVs). SVs can be distinguished from KVs by the chemical markers mannitol and sorbitol, although the production processes for both types of vinegars are similar. Principal component analysis (PCA) was used to distinguish SVs from ZVs and NVs. The differences among the three kinds of vinegars shown by PCA results may be due to the higher erythritol content in SVs, and the inositol and mannitol in ZVs. This study also found that the amount of polyalcohols in Chinese vinegars increases with the acidity value only, regardless of the aging time. The overall results indicated that the polyalcohols can be practicable discriminators for SV discrimination.

Localized surface plasmon resonance light-scattering sensor for mercury(II) ion with label-free gold nanoparticles.

A localized surface plasmon resonance (LSPR) light-scattering sensor for Hg2+ was developed with unmodified gold nanoparticles (AuNPs) based upon the specific recognition property of Hg2+ with T-T mismatched base pair. Oligonucleotide 5'-GTTCTTTGTCTTCA-3'(oligo-1) and 5'-TGTAGTCTATGTAC-3'(oligo-2) can adsorb on the surface of AuNPs, which can prevent them from aggregation because of electrostatic repulsion. However, the DNA hybridization occurred between oligo-1 and oligo-2 upon addition of Hg2+, can induce the desorption of oligonucleotide from the surface of AuNPs, and trigger the aggregation of AuNPs accompany with the increase of LSPR light-scattering intensity. Under the optimum conditions, the intensity was proportional to the concentration of Hg2+ over the range 53.1-530 nM, and the detection limit was 29.4 nM.

Sensitive detection of H2O2 and H2O2-related reactant with Ru(bipy)(2)(7,8-dimethyl-dipyridophenazine)2+ and oligodeoxyribonucleotide.

A sensor for H(2)O(2) and H(2)O(2)-related reactant was constructed with oligonucleotides and Ru(bipy)(2)dppx(2+) (bipy = 2,2'-bipyridine, dppx = 7,8-dimethyl-dipyridophenazine), which was performed by converting the H(2)O(2)-induced DNA cleavage into the change of luminescence. The 'DNA light switch' Ru(bipy)(2)dppx(2+) could emit strong luminescence in the presence of dsDNA. DNA cleavage occurred upon addition of H(2)O(2) due to the Fenton reaction, which resulted in the decrease of the luminescence of Ru(bipy)(2)dppx(2+). Therefore, the luminescence intensity depended on the concentration of H(2)O(2) and H(2)O(2)-related reactants, and the detection limits for H(2)O(2), uric acid and cholesterol were 0.20 µM, 0.46 µM and 1.25 µM, respectively. The recovery varied between 94.0% and 105.0% when the assay was applied to the determination of uric acid and cholesterol in biological samples, which demonstrated the good practicability of the assay.

Colorimetric detection of cholesterol with G-quadruplex-based DNAzymes and ABTS2-.

A novel colorimetric method for detection of cholesterol was developed with hemin-G-quadruplex DNAzyme by transducing oxidation of cholesterol into the color change of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS(2-)). Oligonucleotide 5'-GTGGGTAGGGCGGGTTGG-3' (Oligo-1) formed G-quadruplex structure in the presence of K(+), it acted as a horseradish peroxidase (HRP) mimicking DNAzyme when binding hemin and catalyzed the oxidation of colorless ABTS(2-) to green ABTS(·-) by H(2)O(2), which was produced by the reaction of cholesterol and oxygen that catalyzed by cholesterol oxidase. Therefore, the oxidation of cholesterol could be transduced into the color change of ABTS(2-) by combining these two reactions. Under the optimum conditions, the absorbance was proportional to the concentration of cholesterol over the range of 1.0-30 µM, with a linear regression equation of A=0.362+0.0256C (C: µM, R=0.998) and a detection limit of 0.10 µM (3σ/slope). Moreover, the practicability of the assay in the detection of cholesterol in human serum was studied as well.

Label-free, sensitive detection of Hg(II) with gold nanoparticles by using dynamic light scattering technique.

A label-free method for sensitive detection of Hg(2+) was developed with gold nanoparticles (AuNPs) by using dynamic light scattering (DLS) technique. Oligonucleotide 5'-TTT CTT CTT CGT TGT TGT TT-3' could transform from uncoil to rigid duplex or hairpin structure upon addition of Hg(2+) ions, which was confirmed by experiments of fluorescence resonance energy transfer and change of melting temperature. The change of DNA structure reduced its adsorption ability on the surface of AuNPs, and resulted in the aggregation of AuNPs in the salt solution, which could be estimated with average hydrodynamic diameter by using DLS technique. Under the optimum conditions, the average diameter increased linearly with the concentration of Hg(2+) over the range from 0.75 nM to 25 nM, the linear regression equation was D=46.7+2.0C (nM, R=0.9958), with a detection limit of 0.43 nM.

Dynamic-light-scattering-based sequence-specific recognition of double-stranded DNA with oligonucleotide-functionalized gold nanoparticles.

An ultrasensitive and simple dynamic-light-scattering (DLS) assay for the sequence-specific recognition of double-stranded DNA (dsDNA) was developed based on detection of the average diameter change of Au nanoparticle (AuNP) probes modified with oligonucleotides 5'-TTTCTCTTCCTT- CTCTTC-(T)(12)-SH-3' (Oligo 1) and 5'-TTCTTTCTTTTCTTTTTC-(T)(12)- SH-3' (Oligo 2). The target dsDNA was composed of two complementary oligonucleotides: 5'-AAAGAGAAGGAAGAGAAGAAGAAAGAAAAGAAAAAG-3' (Oligo 3) and 3'-TTTCTCTTCCTTCTCTTCTTCTTTCTTTTCTTTTTC-5' (Oligo 4). Hybridization of the two AuNPs-Oligo probes with the target dsDNA induced aggregation of the target dsDNA by forming triplex DNA, which accordingly increased the average diameter. This diameter change could then be detected by DLS. The average diameter was proportional to the target dsDNA concentration over the range from 593 fM to 40 pM, with a detection limit of 593 fM. Moreover, the assay had good sequence specificity for the target dsDNA.

[Spectral study on the interaction of [Cu(DPPZ)(L-Ser)]+ complex with DNA and its analytical application].

The characteristics of resonance light scattering (RLS), UV-visible absorption spectra and fluorescence spectra of [Cu(DPPZ)(L-Ser)]+ with DNA were studied and a RLS method for the determination of DNA was established. [Cu(DPPZ) (L-Ser)]+ could assemble on the surface of DNA through intercalation, and enhanced the RLS of DNA in the tris buffer of pH 7. 2. The maximum resonance light scattering peak appeared at 400 nm. Under the optimum conditions, the enhanced intensity of RLS was proportional to the concentration of DNA over the range of 0.42 - 4.2 ng x mL(-1), with a detection limit (3sigma/k) of 0.29 ng x mL(-1). The method was used for the determination of DNA samples with the recoveries between 97.8% and 106%.

Gold nanoparticles-based colorimetric investigation of triplex formation under weak alkalic pH environment with the aid of Ag+.

A novel colorimetric method for investigating triplex formation between oligonucleotide modified Au nanoparticles (AuNPs) under weak alkalic pH environment is developed based upon the specific recognition property of Ag+ with CGC triads. Oligonucleotide 5'-SH-T12-CTTCTTTCCTTTCTTC-3' (oligo-1) is modified on the surface of AuNPs. Upon addition of oligonucleotide 5'-GAAGAAAGGAAAGAAG-3' (oligo-2), triplex formation between oligo-1 modified AuNPs occurred at pH 8.0 with the aid of Ag+, triggers the aggregation of AuNPs, accompany with the solution color change from red to purple. The melting temperature demonstrates a 31 °C increase for the triplex DNA compose of 10 T•A∘T triads and 6 C•G∘C triads upon addition of Ag+, the disassociation constant (Kd) between Ag+ and C•G∘C triads is 3.6 µM. Moreover, triplex formation between AuNPs depending on Ag+ can be used to recognize Ag+ ion with the naked eye, as well as UV-vis absorption spectroscopy.

Sensitive and selective localized surface plasmon resonance light-scattering sensor for Ag+ with unmodified gold nanoparticles.

A novel localized surface plasmon resonance (LSPR) light-scattering sensor for Ag(+) was developed with unmodified gold nanoparticles (AuNPs), based upon the specific recognition property of Ag(+) with a cytosine-cytosine mismatched base pair. The addition of Ag(+) induced the oligonucleotide 5'-TAC ATA CAT ACT ATC TAT CTA-3' to be desorbed from the surface of the AuNPs, resulting in the aggregation of AuNPs, accompanied by a dramatic enhancement of the LSPR light-scattering intensity. The enhancement of LSPR light-scattering intensity was proportional to the concentration of Ag(+) in the range of 0.13-1.12 µM, with a limit of detection of 62.0 nM. The results were also proved by a colorimetric method. Furthermore, this method can provide satisfactory results for the determination of Ag(+) in water samples and industrial products.

Colorimetric recognition of DNA intercalators with unmodified gold nanoparticles.

A colorimetric approach to recognize the binding mode between DNA and molecules was developed, which was based upon the electrostatic interaction between DNA and gold colloids.