Alanine Substitution to Determine the Effect of LR5 and YR6 Rice Peptide Structure on Antioxidant and Anti-Inflammatory Activity.

The relationship between the structure of peptides LR5 (LHKFR) and YR6 (YGLYPR) and their antioxidant and anti-inflammatory activity remains unclear. Herein, leucine, tyrosine, proline, and phenylalanine at different positions in the peptides were replaced by Alanine (Ala), and two new pentapeptides (AR5 and LAR5) and four hexapeptides (AGR6, YAR6, YLR6, and YGR6) were obtained. The effect of Ala replacement on the hydrophobicity, cytotoxicity, NO inhibition rate, and active oxygen radical scavenging ability of these peptides and their antioxidant and anti-inflammatory abilities were investigated. The results indicated that the hydrophobicity of the peptides was associated with their amino acid composition and their specific sequence. However, hydrophobicity had no significant effect on cytotoxicity. Ala replacement was shown to enhance hydrophobicity and consequently increased the antioxidant and anti-inflammatory activity of the peptides. The molecular docking studies indicated that the amino acid interactions of the peptide with the Keap1 protein influenced the hydrophobicity and thus affected the antioxidant activity of the peptide.

An iron-based metal-organic framework as a novel dispersive solid-phase extraction sorbent for the efficient adsorption of tetrabromobisphenol A from environmental water samples.

For environmental safety, it is important to establish a simple, rapid, and sensitive method for emerging pollutants. Here, a dispersive solid-phase extraction (d-SPE) method based on an iron-based metal-organic framework (Fe-MIL-88-NH2) combined with high-performance liquid chromatography (HPLC) was developed for tetrabromobisphenol A (TBBPA) in water samples. Fe-MIL-88-NH2 was synthesized using a solvothermal method and completely characterized. Fe-MIL-88-NH2 had good water stability and gave a maximum adsorption capacity of 40.97 mg g-1 for TBBPA. The adsorption of TBBPA on Fe-MIL-88-NH2 followed Langmuir adsorption models and a pseudo-second-order kinetic model. The bromine ion and the hydroxyl group of TBBPA could form strong hydrogen bond interactions with the amino protons around the cavity of Fe-MIL-88-NH2, which was in accord with the molecular simulation calculations. Furthermore, several important d-SPE parameters were optimized, such as the amount of materials, extraction time, pH, ionic strength, elution solvent type, and volume. The established method showed good linearity in the concentration range of 0.005-100 µg g-1 (r2 ≥ 0.9996). This method's limits of detection (LOD) and quantification (LOQ) were 0.001 µg g-1 and 0.005 µg g-1, respectively. The recoveries in spiked water samples ranged from 87.5% to 104.9%. The proposed method was applied successfully to detect TBBPA in environmental water samples.

Exploration of double Z-type ternary composite long-afterglow/graphitic carbon nitride@metal-organic framework for photocatalytic degradation of methylene blue.

Methylene blue (MB) is a very widely used cationic dye for color cotton and silk products. The harmful MB has a complex aromatic structure that is difficult to be degraded in natural aqueous. In this study for the first time, a novel double Z-type ternary composite long-afterglow/graphitic carbon nitride@metal-organic framework (SrAl2O4:Eu2+,Dy3+/g-C3N4@NH2-UiO-66, SGN) has been synthesized by solvothermal method, and was used as a new photocatalyst for removal of MB. The photocatalytic performance of the composited photocatalyst SGN was largely improved compared to that of the non-composite. After 30 min of photocatalysis, the degradation ratio of SGN was 5.86, 4.04 and 10 times more efficient than that of long-afterglow (SAO), g-C3N4 and NH2-UiO-66, respectively. The high photocatalytic activity of the SGN could be ascribed to the double Z-type electron transfer mechanism. More importantly, due to the luminescence of SAO, the degradation ratio of ternary SGN can reach about 50 % after 5 h in the dark. Superoxide anion (·O2-) was verified to be the main active substance in the photocatalytic process by quenching experiments and electron spin resonance (ESR) spectra analysis. The total organic matter contents (TOC) and partial degradation products were measured, which confirmed that some MB was mineralized into H2O and CO2, and some was degraded into smaller molecules. Moreover, the excellent stability and recyclability of this catalyst were also investigated. Here, a new promising material with high degradation performance for water pollution treatment is presented.

Exploration of long afterglow luminescent materials composited with graphitized carbon nitride for photocatalytic degradation of basic fuchsin.

The frequent exposure of the widely used dye, basic fuchsin (BF), is seriously threatening the health of human central nervous system. Thus, removing the environmental pollution caused by BF is crucial, and photocatalytic technology recently has been used to degrade the pollutions dye. In this study, the binary composite SrAl2O4:Eu2+, Dy3+/g-C3N4 was prepared by high-temperature calcination and then applied in BF photodegradation. The results confirmed that the composite material had lower band gap value (Eg) and stronger visible light absorption ability. The photocatalytic capacity of the new composite materials was enhanced compared to that of the non-composite materials. By using the new binary-composited materials, 80% of BF could be degraded in 10 min, and the degradation ratio reached 100% in 30 min. More importantly, even the light source was removed, the photocatalytic reaction could continue due to the luminescence of SrAl2O4:Eu2+, Dy3+, and the degradation efficiency of BF could finally reach more than 90% within 3 h. By quenching experiments and electron spin resonance (ESR) spectra analysis, superoxide anion (·O2-) was verified to be the main active substance in this reaction process. Moreover, the excellent stability and recyclability of this catalyst was also proved. Furthermore, the new composite materials were utilized to degrade the BF aqueous solution and actual lake water, and the total organic matter contents (TOC) were measured. TOC values in these two systems decreased after photocatalytic reaction, which indicated that this catalyst has a great development prospect in the removal of organic matter in water. Our study confirmed a new kind of material of high performance with great significance for emergency treatment of water pollution in practical applications.

Magnetic relaxation switching assay based on three-dimensional assembly of Fe3O4@ZIF-8 for detection of cadmium ions.

The design and construction of a novel magnetic resonance switch (MRS) sensor for cadmium ion (Cd2+) detection is described. Fe3O4@ZIF-8 was synthesized through seed-mediated growth of dimercaptosuccinic acid-coated Fe3O4. Fe3O4@ZIF-8 with high relaxation value (163.086 mM-1 s-1) and large negative zeta potential (-20.69 mV) exhibited good magnetic relaxation performance and water solubility. The successfully synthesized Fe3O4@ZIF-8 was used to develop an immune recognition-based MOFs-MRS sensor for highly sensitive detection of Cd2+. The proposed MRS detected a wide linear range of Cd2+ concentration from 2 to 200 ng mL-1 with a low limit of detection of 0.65 ng mL-1 (S/N = 3), and displayed high selectivity towards matrix interference. The robust sensing system was effective even in a complex sample matrix, enabling the quantitative analysis of Cd2+ content in rice samples and drinking water samples with good reliability. Recoveries of Cd2+ ranged from 91.50 to 112.05% for spiked drinking water and from 95.86 to 110.45% for spiked rice samples. The versatility of Fe3O4@ZIF-8 with customized relaxation responses could allow the adaptation of magnetic resonance platforms for food safety purposes.

Porphyrin NanoMOFs as a catalytic label in nanozyme-linked immunosorbent assay for Aflatoxin B1 detection.

Food safety is a global problem, and methods to reliably and sensitivity detect contaminants could be transformative. Herein, we synthesized a novel Porphyrin NanoMoFs (NanoPCN-223(Fe)) with excellent dispersion and peroxidase-like activity. The Km value of NanoPCN-223(Fe) was 2.0 × 10-4 M toward the H2O2 substrate during the catalytic process. We use the NanoPCN-223(Fe) to construct an enhanced dispersion MOF-linked immunosorbent assay (Ed-MOFLISA) to sensitive detect AFB1 in milk. The optimized Ed-MOFLISA displayed a broad quantitative range from 0.05 to 10 ng/mL and a limit of detection of 0.003 ng/mL. Spiked peanut and soy milk recovery ranged from 91.22% to 97.63%. Intra-assay and inter-assay coefficient of variation values ranged from 0.78 to 3.85%, demonstrating the outstanding reproducibility and accuracy of Ed-MOFLISA. We applied the Ed-MOFLISA assay to test the milk samples, demonstrating its potential use for monitoring food quality.

Effects of strength exercises combined with other training on physical performance in frail older adults: A systematic review and meta-analysis.

OBJECTIVES: Strength training is one of the most important protocols for frailty prevention in the older population. However, effects of adding other types of exercise to strength training in frail older adults remain unknown. Therefore, this review and meta-analysis determined the effects of strength exercise combined with other types of training on physical performance in frail older adults. METHODS: MEDLINE, PubMed, CINAHL, and Cochrane databases were searched through October 2021. In our study, we included both pre-frailty and frailty as frail older adults. The intervention was strength training combined with other exercise training, whereas the control group received usual care or light-intensity exercises. The included studies included at least one of the following outcomes: handgrip strength, knee extensor strength, gait speed, Timed Up and Go, and short physical performance battery. RESULTS: Ten articles met the inclusion criteria and were included. The results indicated that handgrip strength (SMD = 0.86, 95% CI= 0.01-1.70, p = 0.05), knee extensor strength (SMD = 0.61, 95%CI = 0.12-1.10, p = 0.01), TUG (SMD = -1.79, 95%CI = -3.16- -0.43, p=0.01), and SPPB (SMD = 0.53, 95%CI = 0.12-0.94, p = 0.01) improved significantly in the experimental group. CONCLUSIONS: Strength exercise combined with other exercise training improved muscle strength, TUG, and SPPB, but not gait velocity, in frail older adults.

A novel magnetic metal-organic framework absorbent for rapid detection of aflatoxins B1B2G1G2 in rice by HPLC-MS/MS.

In this study, a core-shell-structured magnetic metal-organic framework (MMOF) composite material (Fe3O4@UiO-66-NH2) was synthesized by the solvothermal method. It was employed as a new absorbent in combination with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for the simultaneous detection of four aflatoxins (AFs) in rice. This method could shorten the pre-processing time by exploiting the advantageous characteristics of magnetic cores. The impurity was removed quickly. The effects of extraction solution, extraction time, adsorbent types, and amount of adsorbent on the extraction rate of target compounds were optimized. Under optimized conditions, AFs were validated and showed a good linear relationship within the 0.375-20 µg kg-1 concentration range (r2 > 0.9992). The limit of detection (LOD) was 0.0188-0.1250 µg kg-1 and the limit of quantification (LOQ) was 0.0375-0.3750 µg kg-1. At three spiking levels (0.375, 2, and 10 µg kg-1), the average recovery values for the four AFs ranged from 85.1% to 111.0%. The relative standard deviation ranged from 3.4% to 7.7%. The new method proved to be simple, fast, efficient, and suitable for the determination of AFs in rice samples.

Application of an improved hollow fiber liquid phase microextraction technique coupled to LC-MS/MS to studying migration of fluorescent whitening agents from plastic food contact materials.

In this paper, a new hollow fiber liquid-phase microextraction method was developed to improve the extraction of five fluorescent whitening agents that migrated from plastics food contact materials. Influencing factors, such as the types of membrane, the extraction solvent, the stirring speed, the addition of salt ion, and extraction time, were investigated in detail. Under the optimal conditions, high enrichment factors (71-205) can be obtained with 15 µL extraction solvent. The new method is advantageous; the polypropylene hollow fiber membrane modified by sepiolite nanoparticles had excellent solvent binding force and mass transfer effect compared with the conventional extraction technique. The extracts were analyzed by high performance liquid chromatography-tandem mass spectrometry, the limits of detection were 0.3 or 0.9 ng kg-1 with good correlation coefficients (r2 ≥ 0.9940) for the five fluorescent whitening agents. The intra-day and inter-day recoveries ranged between 82.6% and 112%, with a relative standard deviation of less than 12%. The established method was successfully applied to the analysis of fluorescent whitening agent migration from four types of plastic food contact materials immersed in three food simulants.

Photocatalytic degradation of imidacloprid by optimized Bi2WO6/NH2-MIL-88B(Fe) composite under visible light.

Imidacloprid as a widely used neonicotinoid insecticide can cause harmful pesticide residue inevitably. Metal-organic frameworks (MOFs) were innovatively composited to improve the light absorption and degradation performance of Bi2WO6 semiconductor, which expanded the photodegradation application in solving environmental problems. Based on the synergistic effect of Bi2WO6 and NH2-MIL-88B(Fe), a Bi2WO6/NH2-MIL-88B(Fe) (BNM) heterojunction photocatalyst with high-performance of photocatalytic degradation activities was successfully synthesized. The optimized BNM catalyst had a good degradation rate under visible light, which was mainly caused by generation of the active ·OH. Transient photocurrent response and electrochemical impedance tests verified that 1:2 BNM exhibits a highest charge separation and a lowest carrier recombination rate which were favorable to the photocatalytic activity. Cycle experiments show that the composite photocatalyst had good reusability and stability which were very important for potential industry applications.

Peroxidase-mimetic activity of a nanozyme with uniformly dispersed Fe3O4 NPs supported by mesoporous graphitized carbon for determination of glucose.

A Fe3O4/mesoporous graphitized carbon (Fe3O4/m-GC) composite was prepared through a facile calcination method with iron-based metal-organic frameworks (Fe-MOFs) as a sacrificial template. After carbonization, the Fe3O4 nanoparticles were uniformly dispersed in the mesoporous carbon support, resulting in spatial structural stability. The mesoporous carbon support obtained was highly graphitized and exhibited eminent electrical conductivity, which accelerated the electron transfer between the Fe3O4 nanoparticles by Fe(II)/Fe(III) redox cycles and m-GC by C = Csp2/C-Csp3 redox cycles, leading to the excellent peroxidase-mimetic activity of Fe3O4/m-GC. Km values for tetramethylbenzidine (TMB) and H2O2 were 26.8 and 15.8 times lower than that of natural horseradish peroxidase, respectively. Taking advantage of the peroxidase-mimetic activity of Fe3O4/m-GC, a colorimetric assay was fabricated for detecting glucose in the range 0.5 ~ 200 µM, with a limit of detection of 0.24 µM. Fig 1 A Schematic illustration of the preparation process of Fe3O4/m-GC, B schematic illustration of a proposed synergistic catalytic mechanism of TMB oxidation by Fe3O4/m-GC.

A nanozyme-linked immunosorbent assay based on metal-organic frameworks (MOFs) for sensitive detection of aflatoxin B1.

In order to avoid the occurrence of false positives and false negatives caused by conventional enzyme-linked immunosorbent assay (ELISA), we established a novel indirect competitive MOF-linked immunosorbent assay (MOFLISA) method for the high throughput and high sensitive detection of aflatoxin B1. This method replaces the natural enzyme with functional MOFs to catalyze a chromogenic system. As a result, the limit of detection (LOD) of the MOFLISA method was 0.009 ng·mL-1 with a linear working range from 0.01 to 20 ng·mL-1. The developed MOFLISA method for AFB1 has a 20-fold improved LOD value compared with the conventional ELISA. The recoveries and relative standard deviations (RSD) ranged from 86.41 to 99.74% and 2.38-9.04%, respectively. The results demonstrate that the recovery rate and accuracy of this detection method is better than that of conventional ELISA, reducing risks offalsepositive andfalsenegativeresults.

Extraction of antioxidant peptides from rice dreg protein hydrolysate via an angling method.

Selective enrichment of the highly active antioxidant peptides is required as the lack of an efficient method leads to long screening processes, hampering the research of antioxidant peptides. A simple synthetic metal-organic framework MIL-53 (Cr) was initially applied to extract specific antioxidant peptides from rice dreg protein hydrolysate. The highest active fraction was further purified by reversed-phase high-performance liquid chromatography. The antioxidant peptides with the highest antioxidant activities were identified as Gly-Asp-Met-Asn-Pro and Leu-Leu-Leu-Arg-Trp by LC-MS. These two peptides were synthesized and also exhibited good scavenging activity on the DPPH free radical, superoxide anion free radical and hydroxyl radical, and good chelating ability on Fe2+. The results confirmed that the angling method was effective for antioxidant peptide enrichment from protein hydrolysates.

Recent Advances in Porphyrin-Based Materials for Metal Ions Detection.

Porphyrins have planar and conjugated structures, good optical properties, and other special functional properties. Owing to these excellent properties, in recent years, porphyrins and their analogues have emerged as a multifunctional platform for chemical sensors. The rich chemistry of these molecules offers many possibilities for metal ions detection. This review mainly discusses two types of molecular porphyrin and porphyrin composite sensors for metal ions detection, because porphyrins can be functionalized to improve their functional properties, which can introduce more chemical and functional sites. According to the different application materials, the section of porphyrin composite sensors is divided into five sub-categories: (1) porphyrin film, (2) porphyrin metal complex, (3) metal-organic frameworks, (4) graphene materials, and (5) other materials, respectively.

Metal Organic Frame-Upconverting Nanoparticle Assemblies for the FRET Based Sensor Detection of Bisphenol A in High-Salt Foods.

To resolve the occurrence of unfulfillable detection in high-salts foods, we used fluorescence resonant energy transfer (FRET) sensors based on nanoparticle upconversion. In this study, we developed a novel FRET sensor for the detection of bisphenol A (BPA) in high-salt foods. We based this approach on the assembly of aptamer modified upconversion nanoparticles (DNA1-UCNPs) and complementary DNA modified metal organic frames (DNA2-MOFs), which possessed corresponding wavelength absorption. Targeting BPA signal transduction was performed using the BPA aptamer, via competitive recognition between the BPA analyte and complementary DNA sequences in a high-salt solution. Sensor adaption in high-salt samples was attributed to functional hydrophilic groups, modified in the MOFs, and the enhanced colloidal stability of these MOFs. The MOF-UCNP assembly displayed considerable analytical performance in terms of BPA detection, with a linear range of 0.1-100 nM, and a limit of detection (LOD) of 0.02 nM, in a 340 mM NaCl food sample (the energy drink, Gatorade). Thus, this method provides a solid basis for small molecules detection in high-salt foods.

Metal-Organic Frameworks with Double Channels for Rapid and Reversible Adsorption of 1,2-Ethylenediamine and Gases.

Selective liquid and gas adsorptions are important for environmental control and industrial processes. Here, unique porous lanthanide-organic frameworks of [Ln2(1,3-pdta)2(H2O)2]n2n- {Ln = La (1), Ce (2), Pr (3), and Nd (4), 1,3-pdta = CH2[CH2N(CH2CO2H)2]2} are template-synthesized by 1,2-ethylenediamine and fully characterized, which possess hydrophobic and hydrophilic open channels simultaneously. The skeletons are stable up to 200 °C. Obvious downfield shifts have been observed for 1,2-ethylenediamine in the confined channel with solid-state 13C NMR measurement. The ammonium salt is directly used for the removal of 1,2-ethylenediamine in water. Its saturated adsorption capacity is reached in <1 min and can be regenerated easily with a similar uptake capacity. Moreover, the materials can also selectively adsorb O2, CH4, and CO2, respectively, which is useful for CO2/CH4, CO2/H2, and O2/N2 separation. The combined hydrophobic and hydrophilic open channels of the lanthanides make them promising functional materials for the elimination of 1,2-ethylenediamine and gas separations.

Metal-Organic Frameworks of MIL-100(Fe, Cr) and MIL-101(Cr) for Aromatic Amines Adsorption from Aqueous Solutions.

MIL-100(Fe, Cr) and MIL-101(Cr) were synthesized by the hydrothermal method and applied to the adsorptions of five aromatic amines from aqueous solutions. These three metal-organic frameworks (MOFs) were well characterized by powder X-ray diffraction (PXRD), scanning electron microscope (SEM), transmission electron microscope (TEM), thermogravimetric analysis (TGA) and surface area analysis. The adsorption mechanism of three MOFs and the effects of the structures of MOFs on the adsorption of aromatic amines were discussed. The results show that the cavity system and suitable hydrogen bond acceptor were important factors for the adsorption for five aromatic amines of aniline, 1-naphthalamine, o-toluidine, 2-amino-4-nitrotoluene and 2-nitroaniline: (a) the saturated adsorption capacity of aniline, 1-naphthylamine and o-toluidine on MIL-100(Fe) were 52.0, 53.4 and 49.6 mg/g, respectively, which can be attributed to the intermolecular hydrogen bond interaction and cavity system diffusion. (b) The adsorption capacity of 2-nitroaniline and 2-amino-4-nitrotoluene on MIL-101(Cr) were 54.3 and 25.0 mg/g, respectively, which can be attributed to the more suitable pore size of MIL-101(Cr) than that of MIL-100(Fe, Cr). The MOFs of MIL-100(Fe) and MIL-101(Cr) can be potential materials for removing aromatic amines from aqueous solutions.

MicroRNA expression profile and functional analysis reveal their roles in contact inhibition and its disruption switch of rat vascular smooth muscle cells.

Contact inhibition and its disruption of vascular smooth muscle cells (VSMCs) are important cellular events in vascular diseases. But the underlying molecular mechanisms are unclear. In this study we investigated the roles of microRNAs (miRNAs) in the contact inhibition and its disruption of VSMCs and the molecular mechanisms involved. Rat VSMCs were seeded at 30% or 90% confluence. MiRNA expression profiles in contact-inhibited confluent VSMCs (90% confluence) and non-contact-inhibited low-density VSMCs (30% confluence) were determined. We found that multiple miRNAs were differentially expressed between the two groups. Among them, miR-145 was significantly increased in contact-inhibited VSMCs. Serum could disrupt the contact inhibition as shown by the elicited proliferation of confluent VSMCs. The contact inhibition disruption accompanied with a down-regulation of miR-145. Serum-induced contact inhibition disruption of VSMCs was blocked by overexpression of miR-145. Moreover, downregulation of miR-145 was sufficient to disrupt the contact inhibition of VSMCs. The downregulation of miR-145 in serum-induced contact inhibition disruption was related to the activation PI3-kinase/Akt pathway, which was blocked by the PI3-kinase inhibitor LY294002. KLF5, a target gene of miR-145, was identified to be involved in miR-145-mediated effect on VSMC contact inhibition disruption, as it could be inhibited by knockdown of KLF5. In summary, our results show that multiple miRNAs are differentially expressed in contact-inhibited VSMCs and in non-contact-inhibited VSMCs. Among them, miR-145 is a critical gene in contact inhibition and its disruption of VSMCs. PI3-kinase/Akt/miR-145/KLF5 is a critical signaling pathway in serum-induced contact inhibition disruption. Targeting of miRNAs related to the contact inhibition of VSMCs may represent a novel therapeutic approach for vascular diseases.

Safety assessment of a new multivitamin.

A newly created multivitamin possesses many protective health functions. To investigate its safety when applied in medical treatment and when used as a food supplement, we studied its acute oral toxicity and 13-week oral toxicity in mice. The results showed that the oral lethal dose, 50% (LD(50)) of the biomass of the multivitamin in mice was greater than 2492 mg/kg body weight (BW) and that poisoned mice recovered within 72 h. The no observed effect level (NOEL) of long-term consumption was more than 249.3mg/kg BW for haematological parameters, clinical chemistry parameters, histopathological examination of organs, food consumption, BW, ratio of organ weight to BW and other physiological parameters and conditions. Therefore, we conclude that dosages of up to 249.3 mg/kg BW/day of this multivitamin do not cause chronic toxicity in animals. Administration of this multivitamin may even improve the resistance of animals to negative environmental factors and may be safe for long-term consumption to enhance the health of individuals in accordance with the prescribed dosage (1.4 ∼ 4.2 mg/kg BW/day).