Performance Liquid Chromatography-mass Spectrometer Research Articles

Rationally designed C-PANI/BiOBr STEP-scheme heterojunction photocatalyst for boosting photodegradation of 17β-estradiol

17β-estradiol (E2) in natural water has caused serious environmental problems because of its extremely high estrogenic activity. Herein, a novel β-CD@PANI/BiOBr (C-PANI/BiOBr) step scheme (S-scheme) heterojunction photocatalyst was successfully prepared via facile chemical precipitation method. The encapsulation of β-cyclodextrin (β-CD) around polyaniline (PANI) contributed to better transfer of photogenerated carries by the stabilization of radical cation and excellent adsorption capability driven by hydrophobic interaction, hydrogen bonding and π-π stacking. The C-PANI/BiOBr heterojunction photocatalysts realized excellent light absorption in full spectrum. The N derived from C-PANI could coordinate with Bi metal ions, which favored forming BiOBr with (110) facet exposure, thus promoting the photogenerated electron-hole separation. The optimal 20% C-PANI/BiOBr achieved rapid degradation of contaminants (100% removal of E2 in 40 min and RhB in 9 min) under visible light irradiation. Furthermore, three main degradation pathways of E2 photodegradation were proposed by high performance liquid chromatography-mass spectrometer (HPLC-MS) results, and the toxicity of E2 and intermediates were evaluated by ECOSAR program. The active species capture experiment indicated that h+ and •O2– played the dominated roles in the photodegradation process and S-scheme mechanism of C-PANI/BiOBr with enhanced photocatalytic performance was also revealed. This study provided an insight in fabricating efficient photocatalysts for environmental remediation.

Age-related changes in the ratio of Type I/III collagen and fibril diameter in mouse skin.

The content of type I collagen (COL-I) and type III collagen (COL-III) and the ratio between them not only affect the skin elasticity and mechanical strength, but also determine the fibril diameter. In this research, we investigated the age-related changes in COL-I/COL-III ratio with their formed fibril diameter. The experimental result was obtained from high performance liquid chromatography-mass spectrometer, hydroxyproline determination, picrosirius red staining and transmission electron microscopes (TEM), respectively. The result indicated that the COL-I/COL-III ratio in mouse skin increased with aging. From the 0th to 9th week, the COL-I/COLIII ratio increased from 1.3:1 to 4.5:1. From the 9th to the 18th week, it remained between 4.5:1 and 4.9:1. The total content of COL-I and COL-III firstly increased and then decreased with aging. The TEM result showed that the fibril diameter increased with aging. From the 0th to 9th week, the average fibril diameter increased from 40 to 112 nm; From the 9th to 18th weeks, it increased from 112 to 140 nm. After the 9th week. The fibril diameter showed obvious uneven distribution. Thus, the COL-I/COLIII ratio was proportional to the fibril diameter, but inversely proportional to the uniformity of fibril diameter.

Identification of metabolic biomarkers associated with the onset of type 2 diabetes based on a nested case-control study

Objective: To explore metabolic biomarkers associated with the onset of type 2 diabetes. Methods: Cluster random sampling method was used to select 10 867 local residents aged ≥ 20 years in Liangxi district of Wuxi City, Jiangsu Province in 2007. The baseline survey and physical examination were conducted to collect participants' information, including demographic characteristics, behavior and lifestyles, disease history, family history of diabetes, height, weight, waist circumference and blood pressure, etc. Blood samples were collected and biochemical indexes (high density lipoprotein cholesterol, total cholesterol, triglyceride, fasting blood glucose, etc.) were tested. By June 30, 2020, 220 newly diagnosed patients with type 2 diabetes during the follow-up were selected as cases, and 220 healthy individuals were matched as controls with age (±5 years) and the same sex. High performance liquid chromatography mass spectrometer was used to detect and identify metabolites in serum samples of two groups at baseline. Lasso regression and multivariate conditional logistic regression were used to explore the metabolites associated with the onset of type 2 diabetes. Results: The age of participants at baseline was (53±7) years, and 41.82% were male. 25 out of 1 579 metabolites were selected to be potentially associated with the onset of type 2 diabetes in the lasso regression model. The multivariable conditional logistic regression analysis showed that only 7-Methylxanthine had an independent effect on type 2 diabetes (P=0.019). The area under the receiver operating characteristic curve (AUC) (95%CI) of the prediction model of type 2 diabetes based on traditional risk factors was 0.80 (0.76-0.85). After the 7-methylxanthine in the model, the AUC (95%CI) increased to 0.92 (0.89-0.95) (P<0.001). From the second year, 7-methylxanthine could improve the prediction performance (P=0.007). Conclusion: The level of 7-methylxanthine is related to the onset of type 2 diabetes, and can be used as a biomarker to predict its incidence risk.

An optimal medicinal and edible Chinese herbal formula attenuates particulate matter-induced lung injury through its anti-oxidative, anti-inflammatory and anti-apoptosis activities

ObjectiveIdentifying novel strategies to prevent particulate matter (PM)-induced lung injury is crucial for the reduction of the morbidity of chronic respiratory diseases. The combined intervention represented by herbal formulae for simultaneously targeting multiple pathological processes can provide a more beneficial effect than the single intervention. The aim of this paper is therefore to design a safe and effective medicinal and edible Chinese herbs (MECHs) formula against PM-induced lung injury. MethodsPM-induced oxidative stress, inflammatory response and apoptosis A549 cell model were used to screen anti-oxidant, anti-inflammatory and anti-apoptotic MECHs, respectively. A network pharmacology method was utilized to rationally design a novel herbal formula. Ultra performance liquid chromatography-mass spectrometer was utilized to assess the quality control of MECHs formula. The excretion of magnetic iron oxide nanospheres of the MECHs formula was estimated in zebrafish. The MECH formula against PM-induced lung injury was investigated with mice experiments. ResultsFive selected herbs were rationally designed to form a new MECH formula, including Citri Exocarpium Rubrum (Juhong), Lablab Semen Album (Baibiandou), Atractylodis Macrocephalae Rhizoma (Baizhu), Mori Folium (Sangye) and Polygonati Odorati Rhizoma (Yuzhu). The formula effectively promoted the magnetic iron oxide nanospheres excretion in zebrafish. The mid/high dose formula significantly prevented PM-induced lung damage in mice by enhancing the activity of SOD and GSH-Px, reducing the MDA and ROS level and attenuating the upregulation of pro-inflammatory cytokine (IL-6, IL-8, IL-1β and TNF-α), down regulating the protein expression of NF-κB, STAT3 and Caspase-3. ConclusionOur findings suggest that the effective MECHs formula will become a novel strategy for preventing PM-induced lung injury and provide a paradigm for the development of functional foods using MECHs.

Combining Metabolic Analysis With Biological Endpoints Provides a View Into the Drought Resistance Mechanism of Carex breviculmis.

Metabolomics is an effective tool to test the response of plants to environmental stress; however, the relationships between metabolites and biological endpoints remained obscure in response to drought stress. Carex breviculmis is widely used in forage production, turf management, and landscape application and it is particularly resistant to drought stress. We investigated the metabolomic responses of C. breviculmis to drought stress by imposing a 22-day natural soil water loss. The results showed that water-deficit restrained plant growth, reducing plant height, leaf fresh weight, and total weight, however, increasing soluble protein content and malondialdehyde content. In total, 129 differential metabolites in the leaves were detected between drought and control using the Ultrahigh Performance Liquid Chromatography-Mass Spectrometer (UPLC-MS) method. Drought enhanced most of the primary and secondary metabolites in the differential metabolites. Almost all the sugars, amino acids, organic acids, phytohormones, nucleotides, phenylpropanoids and polyketides in the differential metabolites were negatively correlated with plant height and leaf fresh weight, while they were positively correlated with soluble protein content and malondialdehyde content. Metabolic pathway analysis showed that drought stress significantly affected aminoacyl-tRNA biosynthesis, TCA cycling, starch and sucrose metabolism. Our study is the first statement on metabolomic responses to drought stress in the drought-enduring plant C. breviculmis. According to the result, the coordination between diverse metabolic pathways in C. breviculmis enables the plant to adapt to a drought environment. This study will provide a systematic framework for explaining the metabolic plasticity and drought tolerance mechanisms of C. breviculmis under drought stress.

Investigation and analysis of pesticide residues in edible fungi produced in the mid-western region of China

The present study sought to investigate the levels of multi-pesticide residues in highly consumed edible fungi in China's western regions. A total of 354 edible fungi samples were collected from the local markets, and the concentrations of 53 pesticides in these samples were determined through high performance liquid chromatography mass spectrometer (HPLC/MS/MS). Carbendazim, acephate, procymidone, prochloraz, aldicarb sulfone,etc. were found to be the primary pesticides in the edible fungi samples. Carbendazim had the highest detection rate (70.9%), followed by acephate (13.0%) and procymidone (7.3%), and the detection concentrations were 0.0002–2.7316 mg/kg, 0.0248–0.4985 mg/kg, 0.1807–0.3928 mg/kg, respectively. Nearly 52 (14.7%) edible fungi samples were free of pesticide residues, while the remaining contained one or more pesticide residues. In terms of safety index and risk coefficient, the safety status of edible fungi is acceptable. This study will provide insights into the current contamination status in the key agricultural areas in China and develop food safety regulations to control the excessive use of some pesticides on edible fungi.

Eu/GO/PbO2 composite based anode for highly efficient electrochemical oxidation of hydroquinone

Herein, a novel europium/graphene oxide/lead oxide (Eu/GO/PbO2) composite based anode with excellent electrocatalytic performance towards degradation of hydroquinone was prepared by a facile co-electrodeposition method. The composition and micromorphology of the anode was investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) and the results confirmed that europium (Eu) and graphene oxide (GO) were successfully composited with PbO2 and a more compact structure was obtained, which was conductive to enhancing the corrosion resistance of the electrode. Besides, electrochemical measurements indicated that Eu/GO/PbO2 electrode possessed longer service lifetime (87 h), higher oxygen evolution potential (2.64 V), and lower charge transfer resistance (41.08 Ω) than GO/PbO2 and pure PbO2 electrode. The promoted electrocatalytic activity of Eu/GO/PbO2 electrode was ascribed to its stronger hydroxyl radical generation ability, more active sites and lower electron transfer resistance. Additionally, effects of initial hydroquinone concentration, applied current density and initial pH value on the degradation performance of Eu/GO/PbO2 anode were systematically investigated. The behind degradation mechanism of hydroquinone by Eu/GO/PbO2 anode was speculated on the basis of the major intermediates identified by high performance liquid chromatography-mass spectrometer (HPLC-MS). Under the continuous attack of free hydroxyl radicals, hydroquinone was finally decontaminated into CO2 and H2O. The present work demonstrated that Eu/GO/PbO2 composite anode exhibited excellent degradation performance towards hydroquinone.

Carbon nitride coupled with Ti3C2-Mxene derived amorphous Ti-peroxo heterojunction for photocatalytic degradation of rhodamine B and tetracycline

Exploring the solar-driven photocatalyst for antibiotic and dye degradation has been confronted with a great challenge. In this study, a novel and original photocatalyst derived from the g-C3N4/amorphous Ti-peroxo complexes (CATC) heterojunction was successfully synthesized towards Rhodamine B (RhB) and tetracycline (TC) degradation under visible light irradiation (λ>420 nm). Based on the special photocatalytic activity, Ti3C2-Mxene acted as the starting precursor of amorphous Ti-peroxo complexes via one-step H2O2 oxidation route. Multiple characterization techniques were applied to explore the crystal structure, element composition, and photoelectrochemical property of photocatalyst. As expected, the modified photocatalyst possessed a favorable photocatalytic performance towards the preferable reaction rate for RhB (0.0483 min−1) and TC (0.0208 min−1) degradations, which were 16.65 times and 69.3 times higher than that of pure g-C3N4 (CN) material, profiting from the generated direct Z-scheme heterojunction with favorable redox capacity. Here, h+,∙O2- and ∙OH were verified as typical active radicals for RhB and TC degradation through free radical quenching experiments and electron spin resonance characterization. Degradation intermediate products were also confirmed by high performance liquid chromatography–mass spectrometer (HPLC-MS). The effects of initial pH and ionic strength on RhB and TC photocatalytic degradation performances were discussed. In addition, a preferable reusability and stability performance ensured the modification photocatalyst had a great application potential in wastewater treatment. This study provided a unique avenue through one-step method for the construction of g-C3N4 and Mxene based photocatalyst towards the degradation of antibiotics and dyes from wastewater.

Facile construction of novel organic–inorganic tetra (4-carboxyphenyl) porphyrin/Bi2MoO6 heterojunction for tetracycline degradation: Performance, degradation pathways, intermediate toxicity analysis and mechanism insight

Developing durable photocatalysts with highly efficient antibiotics degradation is crucial for environment purification. Herein, tetra (4-carboxyphenyl) porphyrin (TCPP) was loaded onto the surface of Bi2MoO6 microspheres to gain hierarchical organic–inorganic TCPP/Bi2MoO6 (TCPP/BMO) heterojunctions via a facile impregnation strategy. The catalytic properties of these catalysts were comprehensively investigated through the photodegradation of tetracycline hydrochloride (TC) under visible light. Among all the TCPP/BMO heterojunctions, the highest photodegradation rate constant (0.0278 min−1) was achieved with 0.25 wt% TCPP (TCPP/BMO-2), which was approximately 1.15 folds greater than that of pristine Bi2MoO6 and far superior to pure TCPP. The extremely high photocatalytic performance is attributed to the interfacial interaction between TCPP and Bi2MoO6, which favors the efficient separation of charge carriers and the enhancement of visible-light absorbance. TCPP/BMO-2 possesses high mineralization capability and good recycling performance. Photo-induced O2–, h+, and OH were mainly responsible for the degradation of TC. The degradation pathways of TC and toxicity of degradation intermediates were analyzed based on the intermediates detected by the high performance liquid chromatography-mass spectrometer (HPLC–MS) and the toxicity assessment by the quantitative structure–activity relationship (QSAR) prediction. A possible photocatalytic mechanism over TCPP/BMO is proposed. This work offers an insight in developing the porphyrin-based organic–inorganic heterojunctions for effectively remedying pharmaceutical wastewater.

Aquaculture drug degradation in persulfate by PANI-based microparticles controlled via ultrasonic field: Forced motion of “burning hot micromotors”

The triphenylmethane derivative malachite green (tpmMaG) despite repeated prohibitions but is frequently detected in aquatic environment and draws emerging attention because of the potential poisonous effects. The polyaniline/persulfate with ultrasound catalysis (US/PANI-PS) was developed for tpmMaG removal. The effects of 12 factors and the optimization by response surface methodology (RSM) for tpmFG removal were evaluated based on the pseudo-first-kinetics (kobs). From free radical inhibition, the ratios of active species in US/PANI-PS (δ11 = 0.355, δ12 = 0.593) were close to that in US-PS (δ21 = 0.346, δ22 = 0.586) and different to that in PANI-PS and PS systems. A possible degradation pathway (hydroxylation, N-demethylation, deamination, and open-benzene ring) was explored by gas chromatography-mass spectrometer (GC/MS) and high performance liquid chromatography-mass spectrometer (HPLC-MS). The designed reactor involving the US-driven PANI was simulated by acoustic-piezoelectric interaction. From cavitation calculations, the estimated effective-mean temperature at bubble-water interface had little increasing (from 704 K to 711 K) after adding the PANI, however, the adsorption capacity of tpmMaG in reactive zone decreased from 0.0891 μM to 0.0787 μM. The mechanism (PANI hot turbo-micromotors) with US/PANI-PS was proposed. The tpmMaG was removed with a low treatment cost of 2.81 $⋅m−3 (the EE/O value 18.29 kWh⋅m−3) by US/PANI-PS, presenting a cost-effective treating process. The reusability tests and characterizations (contact angle, X-ray diffraction (XRD), and scanning electron microscope (SEM)) further confirmed the stability of PANI.

Construction of BiOCl/CuBi2O4 S-scheme heterojunction with oxygen vacancy for enhanced photocatalytic diclofenac degradation and nitric oxide removal

Construction of step-scheme (S-scheme) heterojunction with superior redox ability is emerging to be an efficient way to develop high-efficiency photocatalysts for environmental pollution control. Herein, a new S-scheme heterojunction photocatalyst built from BiOCl with oxygen vacancies and CuBi2O4 was developed. Compared to pristine CuBi2O4 and BiOCl, this S-scheme heterojunction photocatalysts (BOC/CBO) show enhanced photocatalytic performance in removing aqueous diclofenac (DCF) and gaseous nitric oxide (NO) under visible light irradiation, which is mainly ascribed to the improved charge separation and transfer and redox ability by the S-scheme heterojunction structure and the enhanced catalytic oxidation by tunning the coordination structure and electronic states of O2 by oxygen vacancies. Further, the detailed DCF degradation pathways were studied and confirmed by high performance liquid chromatography–mass spectrometer (HPLC–MS). At last, a possible photocatalytic reaction mechanism based on such a S-scheme heterojunction (BOC/CBO) is proposed. This study provides an insight in constructing high-performance S-scheme heterojunction photocatalysts for environmental pollution remediation.

The protective effect of Veronica ciliata Fisch. Extracts on relieving oxidative stress-induced liver injury via activating AMPK/p62/Nrf2 pathway

Ethnopharmacological relevanceVeronica ciliata Fisch. existed in various Tibetan medicine prescriptions, which was recorded to treat liver diseases in the Tibetan medicine roll of Chinese materia medica. Hypothesis/purposeThe current study aimed to examine the effect of active constituents from V.ciliata relieving oxidative stress-mediated liver injury and clarify the underlying mechanism. Materials and methodstert-Butyl hydroperoxide (BHP) induced liver injury in mice model was established to evaluate the hepatoprotective effect of ethyl acetate extract of V. ciliata (EAFVC). Serum and liver indicators, as well as the histopathological change of liver were examined. Next, the constituents of EAFVC were separated and characterized by high-speed countercurrent chromatography (HSCCC) and Ultra performance liquid chromatography-mass spectrometer (UPLC-MS), respectively. Based on the above, the antioxidant activity of EAFVC and two fractions was evaluated using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2, 2'-azino-bis (3-ethylbenzothiazoli- ne-6-sulfonic acid) (ABTS) free radical scavenging assays. The hepatoprotective activity of EAFVC and its fractions/compounds attenuating ethanol-induced hepatocyte damage in BRL-3A cells was evaluated using the MTT method. The effect of the fraction and compounds with the strongest protective activity on ethanol-induced cytotoxicity, reactive oxygen species (ROS) accumulation, and glutathione (GSH) depletion was investigated. mRNA expression of nuclear factor-E2-related factor 2 (Nrf2) and nuclear factor of κB (NF-κB), as well as their downstream target genes, was determined by RT-qPCR. Finally, the potential mechanism of fraction 1 and luteolin on the AMPK/p62/Nrf2 signal pathway was studied using western blotting. ResultsFirstly, EAFVC could relieve liver impairment induced by t-BHP in mice. Next, fraction 1 enriched with polyphenolic compounds and luteolin derived from EAFVC were screened to yield the highest hepatoprotective activity against ethanol-induced hepatocyte damage. Further study demonstrated that fraction 1 and luteolin relieved BRL-3A cells damage by decreasing the aspartate aminotransferase (AST), alanine transaminase (ALT) and lactate dehydrogenase (LDH) activities, ROS accumulation, as well as the depletion of GSH. Also, we determined that fraction 1 and luteolin suppressed inflammation and apoptosis of BRL-3A cells. The mechanistic studies indicated that fraction 1 could attenuate oxidative stress, inflammation, and apoptosis by activating AMPK phosphorylation, which promotes autophagy associated protein expression (LC3-B, Beclin1 and p62) as well as promote phosphorylation of p62 -dependent autophagic degradation of Keap1, to induce Nrf2 dissociation from Keap1 and translocate to nuclear. Nrf2 in the nuclear activate cytoprotective related genes to exert hepatoprotective function. Finally, we found that luteolin activated the protein expression of p-AMPK, p-p62, p62, Nrf2, and its downstream target genes. ConclusionsThis study clarified that fraction 1 enriched phenolic compounds could attenuate ethanol-induced liver injury in BRL-3A cells via activating AMPK/p62/Nrf2 pathway. Luteolin could serve as the major bioactive component in the therapeutic effect of fraction 1. These active constituents in V. ciliata could be used as the potential drugs targeted activation of AMPK or p62 for relieving oxidative stress-mediated liver disorders.

Quality Parameters, Caffeine and Theobromine Contents and Antioxidant Activity of Artisan and Commercial Chocolate from Brazil

Several types of chocolate were analysed: bitter, half-bitter, milk chocolate, 70% cocoa, white chocolate and cocoa seeds. Analysis of fat, insoluble solids, total phenols, theobromine and caffeine contents and antioxidant capacity were carried out to evaluate the quality of artisan and commercial chocolate products in Brazil. Fat contents and insoluble residues were similar to those reported in the literature. We develop a simple method by HPLC-DAD (High-Performance Liquid Chromatography with Diode-Array Detection) to quantify methylxanthines whose identification has been confirmed by UPLC- MS (Ultra performance liquid chromatography—mass spectrometer). The levels of phenols, caffeine and theobromine varied between types. White chocolate had no phenolics nor caffeine or theobromine. The ones with the highest phenolic contents were those with the highest cocoa mass content. The same happened with the antioxidant activity, which is correlated to the amount of phenolics, caffeine and theobromine, shown by the statistical analysis. It is the presence of cocoa that determines the antioxidant activity of chocolates. This work contributed to the confirmation of the properties of the chocolates, highlighting the importance of the artisan product. Chocolates are important for human health and are considered functional foods.

Occurrence and multiple-level ecological risk assessment of pharmaceuticals and personal care products (PPCPs) in two shallow lakes of China

BackgroundManagement of pharmaceuticals and personal care products (PPCPs) in the environment has become a social issue. In the present study, concentrations of 140 PPCPs at 20 sites in Baiyangdian Lake and Tai Lake from 2016 to 2017 were analyzed by ultra performance liquid chromatography mass spectrometer (UPLC–MS). Risk quotients (RQ) were calculated for each detected chemical at all sites and prioritization indices (PI), based on maximum RQ, were calculated. To assess the risk of chemicals that identified high priority (PI > 1), a more accurate method of joint probability curves (JPCs) was applied.ResultsA total of 42 PPCPs were identified and quantified detected in the two lakes, with maximum concentrations ranging from 0.04 to 889 ng/L. Among these, seven PPCPs were identified as high or moderate-risk pollutants for at least one site, 3 in Tai Lake and 5 in Baiyangdian Lake. Carbamazepine posed significant ecological risk at all 20 sites, such that more attention should be paid to that drug. Based on results of the JPCs, sulfamethoxazole, caffeine, diethyltoluamide, and carbamazepine were categorized as high or intermediate risks.ConclusionOccurrences and distributions of PPCPs were different in the two lakes. Multiple-level risk assessment from simple to more complex was appropriate in chemical risk management.

Metal-free 2D/2D heterojunction of covalent triazine-based frameworks/graphitic carbon nitride with enhanced interfacial charge separation for highly efficient photocatalytic elimination of antibiotic pollutants

A novel polymer-based 2D/2D heterojunction photocatalysts of covalent triazine-based frameworks/graphitic carbon nitride nanosheets (CTFNS/CNNS) heterojunction are successfully obtained by an electrostatic self-assembly method using amine-functionalized CNNS and carboxyl-rich CTFNS. Such large contact surface and appropriate interfacial contact between CNNS and CTFNS plays a critical role in transfer and separation of charge-carriers. The resulting CTFNS/CNNS heterojunction showed significantly enhanced photocatalytic activity under the irradiation of simulated solar light, which could decompose 10 ppm sulfamethazine (SMT) within 180 min with a high degradation efficiency of 95.8 %. Chloride ions can greatly promote the photocatalytic degradation of SMT due to the production of more radical species. O2− is the dominant active species for SMT decomposition over CTFNS/CNNS heterojunction. Moreover, the degradation intermediates of SMT were identified using high performance liquid chromatography-mass spectrometer and the degradation pathway was proposed. This study provides a new insight into the design of 2D/2D heterojunctions using carbon-based nanomaterials, which exhibits great potential in the degradation of sulfonamide antibiotics in wastewaters.

Serum metabonomics analysis of quercetin against the toxicity induced by cadmium in rats

This study aimed to investigate the protective effect of quercetin against the toxicity induced by chronic exposure to low levels of cadmium in rats by an ultra performance liquid chromatography mass spectrometer. Rats were randomly divided into six groups as follows: control group (C), low dose of quercetin group (Q1: 10 mg/kg·bw), high dose of quercetin group (Q2: 50 mg/kg·bw), cadmium chloride group (D), low dose of quercetin plus cadmium chloride group (DQ1), and high dose of quercetin plus cadmium chloride group (DQ2). Cadmium chloride (CdCl2 ) was administered to rats by drinking water ad libitum in a concentration of 40 mg/L. The final amount of CdCl2 ingested was estimated from the water consumption data to be 4.85, 4.91, and 4.89 mg/kg·bw/day, for D, DQ1, and DQ2 groups, respectively. After a 12-week treatment, the serum samples of rats were collected for metabonomics analysis. Ten potential biomarkers were identified for which intensities were significantly increased or reduced as a result of the treatment. These metabolites included isorhamnetin 4'-O-glucuronide, 3-indolepropionic acid, tetracosahexaenoic acid, lysophosphatidylcholine (LysoPC) (20:5), lysoPC (18:3), lysophosphatidylethanolamine (LysoPE) (20:5/0:0), bicyclo-prostaglandin E2, sulpholithocholylglycine, lithocholyltaurine, and glycocholic acid. Results indicated that quercetin exerted a protective effect against cadmium-induced toxicity by regulating lipid and amino acid metabolism, enhancing the antioxidant defense system and protecting liver and kidney function.

Visible-light-driven photocatalytic degradation of sulfamethazine by surface engineering of carbon nitride：Properties, degradation pathway and mechanisms

Polymeric carbon nitride semiconductor has been explored as emerging metal-free photocatalyst for solving the energy shortage and environmental issues. However, the efficiency of carbon nitride is still not satisfying. Herein, a facile copolymerization between L-cysteine and dicyandiamide has been applied to forming the modified carbon nitride photocatalysts. The photocatalytic performance was evaluated through degrading sulfamethazine under visible light illumination. The ameliorative structure and tuned energy band result in visible-light adsorption enhancement. In addition, nitrogen vacancies offer more sites to adsorbing molecular oxygen, thereby facilitating the transfer of electrons from carbon nitride to the surface adsorbed oxygen. As a result, the degradation rate of optimized modified carbon nitride sample for sulfamethazine was 0.1062 min-1, which was almost 12 times than that of carbon nitride (0.0086 min-1). Superoxide radicals and holes were mainly responsible for the sulfamethazine photodegradation by modified carbon nitride. Two reaction intermediates/products were observed and identified by high performance liquid chromatography-mass spectrometer, and a possible reaction pathway was proposed. This study provides new insights into the design of highly efficient photocatalyst for other organic pollutants degradation.

Photocatalytic hydrogen evolution with simultaneous antibiotic wastewater degradation via the visible-light-responsive bismuth spheres-g-C3N4 nanohybrid: Waste to energy insight

Bismuth sphere doped g-C3N4 (Bi/C3N4) nanohybrid has been prepared via a two-step solvothermal method successfully. The structures, morphologies and optical properties of photocatalysts were explored by XRD, SEM, TEM, EDS, XPS and UV–vis spectra. Photocatalytic activities were measured by hydrogen evolution from antibiotic wastewater based on an inspiration of waste to energy. The optimal 2%Bi/g-C3N4 samples demonstrated a H2 evolution rate of 35.9 µmol/h under visible light, which was approximately three times that of pure g-C3N4. Further exploration revealed that hydrogen generation can be enhanced by the Surface Plasmon Resonance (SPR) effect of metallic bismuth, which can be verified by photoluminescence spectra (PL) and time-resoled photoluminescence decay analysis. The products were investigated by gas chromatography (GC) and high performance liquid chromatography (HPLC). Results confirmed that hydrogen evolution with simultaneous degradation of antibiotic wastewater can be achieved. The photocatalytic reaction pathway was determined using the high performance liquid chromatography-mass spectrometer (HPLC-MS) technique, either. Moreover, the samples performed good stability during cycling experiments after studied by XRD and XPS characterizations.

Stability of non-proteinogenic amino acids to UV and gamma irradiation

AbstractAlmost all living organisms on Earth utilize the same 20 amino acids to build their millions of different proteins, even though there are hundreds of amino acids naturally occurring on Earth. Although it is likely that both the prebiotic and the current environment of Earth shaped the selection of these 20 proteinogenic amino acids, environmental conditions on extraterrestrial planets and moons are known to be quite different than those on Earth. In particular, the surfaces of planets and moons such as Mars, Europa and Enceladus have a much greater flux of UV and gamma radiation impacting their surface than that of Earth. Thus, if life were to have evolved extraterrestrially, a different lexicon of amino acids may have been selected due to different environmental pressures, such as higher radiation exposure. One fundamental property an amino acid must have in order to be of use to the evolution of life is relative stability. Therefore, we studied the stability of three different proteinogenic amino acids (tyrosine, phenylalanine and tryptophan) as compared with 20 non-proteinogenic amino acids that were structurally similar to the aromatic proteinogenic amino acids, following ultraviolet (UV) light (254, 302, or 365 nm) and gamma-ray irradiation. The degree of degradation of the amino acids was quantified using an ultra-high performance liquid chromatography-mass spectrometer (UPLC-MS). The result showed that many non-proteinogenic amino acids had either equal or increased stability to certain radiation wavelengths as compared with their proteinogenic counterparts, with fluorinated phenylalanine and tryptophan derivatives, in particular, exhibiting enhanced stability as compared with proteinogenic phenylalanine and tryptophan amino acids following gamma and select UV irradiation.

In vitro and In vivo Antioxidant, Anti-hyperlipidemic Properties and Chemical Characterization of Centella asiatica (L.) Extract.

The study aimed to identify the phenolic compounds present in Centella asiatica (L.) (C. asiatica) extract and evaluate the respective antioxidant potential as well as its cholesterol-lowering effects in the experimental animal model. Herein, the antioxidant potential of extracts was assessed by its free radical scavenging activity such as 2, 2-diphenyl -1- picrylhydrazyl as well as reducing capability. The anti-hyperlipidemic effects of C. asiatica extract (CAE) were evaluated in high cholesterol-fed (HCF) rats for 4 weeks, where different concentrations of extracts (0.25, 0.5, and 1 g/kg/day) were orally administrated daily. Lipid and antioxidant profiles, including total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and superoxide dismutase (SOD), together with the indices of hepatic functions were also examined. C. asiatica revealed excellent free radical scavenging activity as revealed by 2-2- diphenyl-1-picryl-hydrazyl (DPPH) assay, with the IC50 values (9.62 ± 0.88 μg/mL). Furthermore, C. asiatica extracts and fenofibrate remarkably lowered the level of TC, TG, LDL-C, and showed elevated levels of HDL-C, SOD. The histopathological observations further demonstrated clear differentiation and structural changes in liver of HCF and CAE treated group. Furthermore, gulonic acid, ferulic acid, kaempferol, chlorogenic acid, and asiatic acid were identified to be the major components which might be responsible for the antioxidant activity of the C. asiatica extract as evidenced from an ultra-high performance liquid chromatography–mass spectrometer. Taken together, these results signifies the excellent antioxidant and anti-hyperlipidemic properties of C. asiatica leaf extracts, which might be useful for the treatment of oxidative-stress related diseases such as hyperlipidemia.