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Beyond its potential for biofuel production, Pseudomonas putida’s capability to metabolize lignin and other lignocellulosic materials earmarks it as a pivotal candidate for engineering to yield diverse value-added chemicals, thereby challenging traditional petrochemical approaches. Recognizing the inherent environmental, economic, and societal advantages, amplifying role of P. putidain industrial applications becomes imperative. In this context, our study focused on characterizing a comprehensive set of promoters and ribosome binding site tailored for P. putida, spanning a broad spectrum of activities. By leveraging these genetic tools, we adeptly balanced the heterologous mevalonate (MVA) pathway flux within P. putida. As a culmination of our efforts, the optimal MVA-producing strains were identified, achieving a remarkable yield of 5 g/LMVA in a 5 L fed-batch fermenter, marking the highest reported yield in Pseudomonasto date. This research not only provides valuable genetic tools for future engineering studies with P. putida, but also accentuates P. putida’s potential in synthetic biology and its promise for sustainable chemical production.

Lactate dehydrogenase and malate dehydrogenase are the two main alpha-hydroxy acid dehydrogenases in the human body. We investigated the catalytic properties of human lactate dehydrogenase LDHC, LDHL6A and malate dehydrogenase MDH1 on aromatic α-keto acids phenylpyruvic acid, p-hydroxyphenylpyruvic acid and 3,4-dihydroxyphenylpyruvic acid. The optimum temperatures for LDHC, LDHL6A, and MDH1 are 37 °C, 35 °C, and 45 °C, respectively; and the optimum pH is 6.5, 6.5, and 5.5, respectively. The Kmof LDHC for phenylpyruvic acid and 3,4-dihydroxyphenylpyruvic acid were 0.90 mM and 0.92 mM, respectively. LDHL6A has a high affinity for phenylpyruvic acid and 3,4-dihydroxyphenylpyruvic acid with Kmof 0.77 mM and 0.80 mM, respectively; MDH1 has an extremely high affinity (Km= 0.46 mM) and catalytic efficiency (kcat/Km= 23.87 s−1·mM−1) for p-hydroxyphenylpyruvic acid. It also has a high affinity for 3,4-dihydroxyphenylpyruvic acid with a Kmof 0.90 mM, but with a low affinity for phenylpyruvic acid (Km= 3.76 mM). The catalytic properties of human LDHC, LDHL6A, and MDH1 for the abovementioned aromatic α-keto acids may be one of the sources of L-phenyllactic acid, L-p-hydroxyphenyllactic acid, and L-3,4-dihydroxyphenyllactic acid in humans.

Ethyl (R)-4-chloro-3-hydroxybutyrate ((R)-CHBE), as a chiral intermediate, is widely used in the synthesis of various chiral drugs. In this study, we screened two aldo–keto reductases (LP-AKRs) from the probiotic Lactobacillus plantarumDSM20174, both with a molecular weight of approximately 31 kDa. Both enzymes could reduce 4-chloroacetoacetic acid ethyl ester (COBE) to produce (R)-CHBE with an enantioselectivity value of 99%. When determining the kinetic parameter, the Km, Kcat, and Vmaxof LP-AKR5 and LP-AKR9 were 9.5 mM, 7.6 U/mg, 3.96 s−1and 8.7 mM, 8.59 U/mg, 4.47 s−1, respectively. Both LP-AKR5 and LP-AKR9 had an optimal reaction pH of 6 and could maintain a high level of stability at pH 6, allowing them to perform well in an acidic environment. LP-AKR5 and LP-AKR9 had optimal reaction temperatures of 30 °C and 40 °C, respectively. Metal ions had minimal influence on LP-AKR5 and LP-AKR9 enzyme activities. This series of enzymatic properties showed that LP-AKR5 and LP-AKR9 mined from Lactobacillus plantarumDSM20174 could asymmetrically catalyze the synthesis of (R)-CHBE under weakly acidic circumstances, which could maintain product stability and provide a good foundation for industrial production.

MicroRNA (miR) therapeutics is a promising approach to manage coronary artery disease (CAD). Herein, this research was aimed to explore miR-181c-5p-related mechanisms in CAD through regulating SIRT1.

l-Lactate dehydrogenases can reduce alpha-keto carboxylic acids asymmetrically and generally have a broad substrate spectrum. l-Lactate dehydrogenase gene (LF-l-LDH0845) with reducing activity towards 3,4-dihydroxyphenylpyruvate and phenylpyruvate was obtained from Lactobacillus fermentumJN248. To change the substrate specificity of LDH0845 and improve its catalytic activity towards large substrates, site-directed mutation of Tyr221 was performed by analyzing the amino acids in the active center. Kinetic parameters show that the kcatvalues of Y221F mutant on 3,4-dihydroxyphenylpyruvate, 4-methyl-2-oxopentanoate, and glyoxylate are 1.21 s−1, 1.35 s−1, and 0.72 s−1, respectively, which are 420%, 150% and 130% of the wild-type LDH0845. This study shows that the mutations of Y221 can significantly change the substrate specificity of LDH0845, making it become a potential tool enzyme for the reduction of alpha-keto carboxylic acids with large functional groups.

Platelet-derived growth factor receptors (PDGFRs) are now considered promising targets for the treatment of osteosarcoma. Herein, the design, synthesis, and structure–activity relationships (SAR) of novel pyrimidine-2,4-diamine derivatives that selectively inhibit PDGFRα/β kinases have been studied. The screening cascades revealed that 7mwas the preferred compound among these derivatives, with IC50values of 2.4 and 0.9 nM for PDGFRα and PDGFRβ, respectively. Moreover, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) experiment revealed that 7mhas a substantial cytotoxic effect against all osteosarcoma cancer cell lines; 7malso displayed robust antitumor effects and low toxicity in a xenograft model. Additionally, 7mshowed excellent bioavailability (F= 62.9%), suitable half-life (T1/2= 2.12 h), satisfactory metabolic stability, and weak CYP isoform inhibitory activity, suggesting that 7mis a potential drug candidate for PDGFR-driven osteosarcoma.

l-DOPA is a major drug for the treatment of Parkinson’s disease, and microbial enzymatic synthesis is an essential way for its industrial production. The expression of tyrosine phenol-lyase (TPL) derived from Erwinia herbicolaunder six different constitutive promoters in Escherichia coliwas studied. The recombinant strain 5 can express TPL well with growth. The optimal medium composition of this strain was as follows: tryptone 18 g/L, yeast extract 28 g/L, glycerol 10 g/L. After the cell culture is completed, the collected cells were used to catalyze the production of l-DOPA, and the concentration can reach 67.9 g/L.

Chiral tetrahydroisoquinolines (THIQ) is a highly important molecular skeleton in natural alkaloids and biologically active compounds, and its derivatives are often used as key intermediates for the synthesis of drugs. Herein, we described an efficient enantioselective hydrogenation of 3‐substituted isoquinolinium salts catalyzed by a bromine‐bridged dimeric complex [{Ir(H)[(R,S,Sax)‐Ph‐ax‐Josiphos]}2(μ‐Br)3]+Br−. This efficient enantioselective transformation could provide a series of useful chiral cyclic amines, which were of great potential value in natural product modification and drug molecular preparation in high yields and moderate to excellent enantioselectivities (68–97% ee). Additionally, turnover number experiments and a gram‐scale synthesis of chiral 3‐phenyltetrahydroisoquinoline were conducted. An efficient asymmetric hydrogenation of 3‐substituted isoquinolinium saltscatalyzed by a bromine‐bridged dimeric complex was developed, providing a series of chiral 3‐substituted tetrahydroisoquinolines in high yields and moderate to excellent enantioselectivities (68–97% ee).

An efficient enantioselective hydrogenation of sterically hindered cyclic imines catalyzed by the Ir-tBu-ax-Josiphos complex has been described, producing a series of useful chiral bulky tetrahydroisoquinoline analogs in high isolated yields (85–96%) with good to excellent enantioselectivities (74–99% ee). This transformation provided highly straightforward access to the useful derivatives of tetrahydroisoquinolines, which are of great potential value in drug molecule and natural product research.

Proteus mirabiliscould convert l-phenylalanine into 2-phenylethanol (2-PE) via the Ehrlich pathway, the amino acid deaminase pathway, and the aromatic amino acid decarboxylase pathway. The aromatic amino acid decarboxylase pathway was proved for the first time in P. mirabilis. In this pathway, l-aromatic amino acid transferase demonstrated a unique catalytic property, transforming 2-penylethylamine into phenylacetaldehyde. Eleven enzymes were supposed to involve in 2-phenylethanol synthesis. The mRNA expression levels of 11 genes were assessed over time by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in vivo. As a result, the expression of 11 genes was significantly increased, suggesting that P. mirabiliscould transform l-phenylalanine into 2-phenylethanol via three pathways under aerobic conditions; nine genes were significantly overexpressed, suggesting that P. mirabiliscould synthesize 2-phenylethanol via the Ehrlich pathway under anaerobic conditions. This study reveals the multipath synthetic metabolism for 2-phenylethanol in P. mirabilisand will enrich the new ideas for natural (2-PE) synthesis.

Background: Our previous studies showed that α-asaronol was a potential antiepileptic candidate. Here, twelve O-terminus modified ester derivatives of α-asaronol were designed, synthesized and evaluated their anticonvulsant activity. Methods: All synthetic compounds were subjected to three animal models of seizure (MES, scPTZ and sc3-MP models) combined with neurotoxicity test, as well as the LDH inhibitory test. Furthermore, GABAA Receptor modulation and pharmacokinetic evaluation of compound 4k were also performed. Results: Five compounds (4a, 4b, 4d, 4e and 4k) showed significant anticonvulsant properties at the dose of 30-300 mg/kg in MES and scPTZ test, but weak activity in sc3-MP model. Meanwhile, 4a, 4b, 4d and 4k showed good LDH inhibitory activity in vitro. Specifically, 4k was the best compound in above evaluation, and better than that of α-asaronol and reference compound (stiripentol). In addition, 4k could increase chloride ion influx by modulating GABAA receptor α1β2γ2 subtype with EC50 of 48.65 ± 10.31 μM and showed good PK profiles in rats with moderate oral bioavailability (51.5%). Conclusion: These results suggested 4k possesses potential effectiveness in treatment of therapyresistant seizures and is expected to be developed as a novel molecule for safer and efficient anticonvulsants having neuroprotective effects as well as low toxicity.

Indocyanine green (ICG) is a near-infrared (NIR) imaging agent and is also an ideal light absorber for laser-mediated photothermal therapy. This NIR dye could serve as a basis of a dual-functional probe with integrated optical imaging and photothermal therapy capabilities. However, applications of ICG remain limited by its concentration-dependent aggregation, poor aqueous stability, nonspecific binding to proteins and lack of target specificity. To overcome these limitations, a novel ICG-containing nanostructure is designed utilizing the noncovalent self-assembly chemistry between phospholipid-polyethylene glycol (PL-PEG) and ICG. The interactions between both amphiphilic ICG and PL-PEG were studied using absorption and fluorescence spectroscopy. The properties of ICG-PL-PEG nanoprobe, such as absorption and fluorescence spectra, stability, morphology and size distribution, were also investigated. Two representative targeting molecules, namely, a small molecule, folic acid (FA), and a large protein, integrin αvβ3monoclonal antibody (mAb), were conjugated to the surface of ICG-PL-PEG nanoprobe, displaying the diversity of ligand conjugation. The target specificity was confirmed using three cell lines with different levels of available folate receptors (FRs) or integrin αvβ3expression via laser scanning confocal microscope and flow cytometry. This targeting ICG-PL-PEG nanoprobe could be internalized into targeted cells via ligand−receptor mediated endocytosis pathway. Our in vitro experiments showed that internalized ICG-PL-PEG could be used for cell imaging and selective photothermal cell destruction. These results represent the first demonstration of the dual functionality of ICG-containing nanostructure for targeted optical imaging and photothermal therapy of cancerous cells. This novel ICG-PL-PEG nanostructure, when conjugated with other therapeutic and imaging agents, could become a multifunctional probe for cancer diagnosis and treatment.

The past decade has witnessed the great promise of strategies for ligand discovery based on surface-immobilized GPCRs. We present here a method for preparation of immobilized GPCRs. Key features include covalent immobilization with high specificity and robust application in drug-receptor interaction analysis and ligand screening. In our example assay using beta2-adrenergic receptor (β2-AR), the human DNA repair protein O6-alkylguanine-DNA alkyltransferase (hAGT) fusion receptor expressed in Escherichia coliwas directly captured onto polyethylene glycol polyacrylamide (PEGA) resin. We observed even distribution and physiological functions of β2-AR on the resin. The immobilized β2-AR as a stationary phase enabled us to rapidly determine the binding of four drugs to β2-AR. By coupling this assay to mass spectrometry, we screened rosmarinic acid as a bioactive compound targeting β2-AR in Fructus Perillae. We concluded that O6-benzylguanine derivative-functionalized supporter is promising for specific immobilization of hAGT-tagged proteins; immobilized receptor chromatography has great potential in screening receptor-binding leads from herbal plants or traditional medicine recipes.

Hydroxytyrosol is a high-value-added compound with a variety of biological and pharmacological activities. In this study, a whole-cell catalytic method for the synthesis of hydroxytyrosol was developed: aromatic amino acid aminotransferase (TyrB), l-glutamate dehydrogenase (GDH), α-keto acid decarboxylase (PmKDC), and aldehyde reductase (YahK) were co-expressed in Escherichia colito catalyze the synthesis of hydroxytyrosol from l-3,4-dihydroxyphenylalanine (l-DOPA). The plasmids with different copy numbers were used to balance the expression of the four enzymes, and the most appropriate strain (pRSF-yahK-tyrBand pCDF-gdh-Pmkdc) was identified. After determination of the optimum temperature (35 °C) and pH (7.5) for whole-cell catalysis, the yield of hydroxytyrosol reached 36.33 mM (5.59 g/L) and the space-time yield reached 0.70 g L–1h–1.

ABSTRACTThis paper studied the Co–Cr3C2composite coatings on the nickel-based super alloy GH4169 deposited by pulse reverse jet electrodeposition in conjunction with ultrasonic vibration. The GH4169 substrates were first annealed at 500°C for 20 min to eliminate the internal stress, and then the surface was activated chemically. The surface activation procedure and ultrasonic pulse interval time in the jet electrodeposition were investigated. The results showed that the Cr3C2particle contents, microhardness, wear resistance of the coatings were significantly improved, while the surface roughness and the coefficient of friction were reduced, when the ultrasonic vibration is applied in the jet electrodeposition of the Co–Cr3C2composite coatings. It is found that the intermittent ultrasonic vibration at 8 s interval time has the greatest effect on the coatings. The Cr3C2particle content at this condition is at its maximum of 23.85%, with evenly particle distribution and good adhesion with the cobalt matrix. The hardness of the composite coating is 652 HV(0.5), and frictional coefficient is 0.15. It has also high thermal stability, and the microhardness can hold up to 800°C without degradation, showing a great potential for high-temperature applications.

This paper studied the Co–Cr3C2composite coatings on the nickel-based super alloy GH4169 deposited by pulse reverse jet electrodeposition in conjunction with ultrasonic vibration. The GH4169 substrates were first annealed at 500°C for 20 min to eliminate the internal stress, and then the surface was activated chemically. The surface activation procedure and ultrasonic pulse interval time in the jet electrodeposition were investigated. The results showed that the Cr3C2particle contents, microhardness, wear resistance of the coatings were significantly improved, while the surface roughness and the coefficient of friction were reduced, when the ultrasonic vibration is applied in the jet electrodeposition of the Co–Cr3C2composite coatings. It is found that the intermittent ultrasonic vibration at 8 s interval time has the greatest effect on the coatings. The Cr3C2particle content at this condition is at its maximum of 23.85%, with evenly particle distribution and good adhesion with the cobalt matrix. The hardness of the composite coating is 652 HV(0.5), and frictional coefficient is 0.15. It has also high thermal stability, and the microhardness can hold up to 800°C without degradation, showing a great potential for high-temperature applications.

Although a comparatively robust method, immobilized protein-based techniques have displayed limited precision and inconsistent results due to a lack of strategy for the accurate selection of drug adsorption models on the protein surface. We generated the adsorption data of three drugs on immobilized beta-2-adrenoceptor (β2-AR) by frontal affinity chromatography–mass spectrometry (FAC-MS) and site-specific competitive FAC-MS. Using adsorption energy distribution (AED) calculations, we achieved the best adsorption models for the binding of salbutamol, terbutaline, and pseudoephedrine to immobilized β2-AR. The Langmuir model proved to be desirable for describing the adsorptions of salbutamol and terbutaline on immobilized β2-AR, while the bi-Langmuir model was favorable to characterize the adsorption of pseudoephedrine on the receptor. Relying on the accurate determination of association constants, we presented an efficient approach for β2-AR ligand screening based on the loss of breakthrough time of an indicator drug caused by the inclusion of competitive drugs in the mobile phase. We concluded that the current strategy enables the reliable and accurate analysis of G protein-coupled receptor (GPCR)–drug interaction. The percentage change in the breakthrough time for drugs can provide useful information for estimating their binding affinity to the receptor. This approach builds a powerful platform for high-throughput ligand screening.

Epilepsy is one of chronic neurological disorders that affects 0.5–1.0% of the world’s population during their lifetime. There is a still significant need to develop novel anticonvulsant drugs that possess superior efficacy, broad spectrum of activities and good safety profile.

Background: Epilepsy is one of chronic neurological disorders that affects 0.5–1.0% of the world’s population during their lifetime. There is a still significant need to develop novel anticonvulsant drugs that possess superior efficacy, broad spectrum of activities and good safety profile. Methods: a-Asaronol and two current antiseizure drugs (a-asarone and carbamazepine (CBZ)) were assessed by in vivoanticonvulsant screening with the three most employed standard animal seizure models, including maximal electroshock seizure (MES), subcutaneous injection-pentylenetetrazole (PTZ)-induced seizures and 3-mercaptopropionic acid (3-MP)-induced seizures in mice. Considering drug safety evaluation, acute neurotoxicity was assessed with minimal motor impairment screening determined in the rotarod test, and acute toxicity was also detected in mice. Results: In our results, a-asaronol displayed a broad spectrum of anticonvulsant activity (ACA) and showed better protective indexes (PI = 11.11 in MES, PI = 8.68 in PTZ) and lower acute toxicity (LD50= 2940 mg/kg) than its metabolic parent compound (a-asarone). Additionally, a-asaronol displayed a prominent anticonvulsant profile with ED50values of 62.02 mg/kg in the MES and 79.45 mg/kg in the sc-PTZ screen as compared with stiripentol of ED50of 240 mg/kg and 115 mg/kg in the relevant test, respectively. Conclusion: The results of the present study revealed a-asaronol can be developed as a novel molecular in the search for safer and efficient anticonvulsants having neuroprotective effects as well as low toxicity. Meanwhile, the results also suggested that a-asaronol has great potential to develop into another new aromatic allylic alcohols type anticonvulsant drug for add-on therapy of Dravet’s syndrome.

Fracture is a global public health disease. Bone health and fracture risk have become the focus of public and scientific attention. Observational studies have reported that tea consumption is associated with fracture risk, but the results are inconsistent. The present study used 2-sample Mendelian randomization (MR) analysis. The inverse variance weighted method, employing genetic data from UK Biobank (447,485 cases) of tea intake and UK Biobank (Genome-wide association study Round 2) project (361,194 cases) of fractures, was performed to estimate the causal relationship between tea intake and multiple types of fractures. The inverse variance weighted indicated no causal effects of tea consumption on fractures of the skull and face, shoulder and upper arm, hand and wrist, femur, calf, and ankle (odds ratio = 1.000, 1.000, 1.002, 0.997, 0.998; P= .881, 0.857, 0.339, 0.054, 0.569, respectively). Consistent results were also found in MR-Egger, weighted median, and weighted mode. Our research provided evidence that tea consumption is unlikely to affect the incidence of fractures.

Fe2O3 nanoparticles/reduced graphene oxide (Fe2O3/rGO) nanocomposites were synthesized for enhanced electrochemical sensing of N2H4. Fe2O3/rGO nanocomposites were synthesized through a green and facile one-step hydrothermal approach by using L-lysine as both reductant and hydrolysis-controlling agent. Then, the nanocomposites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction spectroscopy (XRD), energy-dispersive X-ray spectrum (EDS), fourier transform infrared spectroscopy (FTIR) and electrochemical techniques. SEM and TEM observations revealed that large numbers of Fe2O3 nanoparticles with spherical morphologies were distributed on the surface of rGO sheets, which made the sensor based on Fe2O3/rGO exhibited an excellent performance toward N2H4 detection with a wide linear range of 0.8 uM to 1.27 mM, a high sensitivity of 525.3 uA mM[?]1 cm[?]2 and a low detection limit of 0.09 uM (S/N = 3). Therefore, the facile approach and excellent experimental results indicated that Fe2O3/rGO nanocomposites can be applied as a promising type of sensing material for electrochemical detection of N2H4.

Shaoyao-Gancao decoction (SGD), a traditional Chinese herbal medicine, was originally described in the Treatise on Cold Pathogenic Diseasesand is composed of Paeoniae Radix albaand Glycyrrhiza Radix et rhizoma. It has been widely used in treating spasmolysis and asthma. In the present study, the therapeutic effects of SGD were assessed, and the detailed mechanisms of SGD for asthma treatment were investigated. We established a rat asthma model and analyzed the changes in the metabonomic profiles of plasma and urine after SGD administration. The metabonomic variations were characterized in control, model, and SGD treatment groups through a combination of nuclear magnetic resonance (NMR) spectroscopy and multivariate statistical analysis. Seventy-four metabolites were detected in rat plasma and urine and analyzed using the orthogonal projection to latent structures discriminate analysis (OPLS-DA). The results showed that some physiological changes and also metabolic disorders were induced in model rats. SGD treatment reduced the injury and maintained metabolic balance, possibly by the regulation of energy metabolism, amino acid metabolism, and metabolism of other metabolites. These findings provide new insights into the pathways associated with the pathogenesis of asthma and the effects of SGD on the endogenous metabolism in rats.

Cu2O/AlOOH/rGO nanocomposites were synthesized by employing AlOOH/rGO as the support for Cu2O catalysts and then the nanocomposites were used for fabricating nonenzymatic glucose sensors. The morphology and composition of the nanocomposites were characterized by transmission electron microscopy and X-ray diffraction spectroscopy. Electrochemical investigations indicate that the nanocomposites possess an excellent performance toward glucose with a wide linear range of 5.0 μM to 14.77 mM, a sensitivity of 155.1 μA mM−1cm−2and a low detection limit of 2.6 μM. These results indicated that the Cu2O/AlOOH/rGO modified electrode can act as a promising non-enzymatic sensor for glucose detection.

The nanocomposites of hollow and porous palladium nanospheres (Pd-HPs) supported on reduced graphene oxide (rGO) were prepared and then applied for electrochemical sensing of hydrogen peroxide (H2O2). Pd-HPs/rGO nanocomposites were synthesized for the first time through a facile one-pot hydrothermal route by using urea as the structure directing agent and reductant. The morphology and composition of the nanocomposites were characterized using transmission electron microscope (TEM), fourier transform infrared spectroscopy and energy-dispersive X-ray spectrum. TEM observations revealed that the as-synthesized Pd-HPs/rGO nanocomposites exhibited a sphere-shaped hollow and porous structure. The electrochemical investigations indicated that Pd-HPs/rGO nanocomposites exhibited excellent electrocatalytic performance toward H2O2 reduction with a linear range from 50.0 uM to 9.25 mM, a high sensitivity of 216.2 uA mM[?]1 cm[?]2 and a low detection limit of 9.5 uM.

Although the association constant and the number of binding sites of prazosin to α1A-adrenoceptor were determined by high performance affinity chromatography (HPAC) in our previous work, the thermodynamic behaviors and the binding mechanism of the drug to immobilized α1A-adrenoceptor remained unclear. This work intended to address the issue by HPAC and molecular docking. The investigations involved the determination of association constants by frontal analysis at different temperatures, the calculation of enthalpy, entropy and free energy changes, the examination of mobile phase composition on the binding parameters and the site-directed molecular docking. The changes of enthalpy, entropy and free energy during the interaction were −20.79 kJ mol−1, −59.28 J mol−1K−1and −2.4 kJ mol−1, respectively. The binding of prazosin to α1A-adrenoceptor was an endothermic process with an increase in entropy. This reaction was mainly driven by hydrogen bonds. The ionic strength of the mobile phase provided a positive response to the values of association constants, while the power of hydrogen and the concentration of isopropyl in the mobile phase showed a negative trend. Ser203and Ser192in the fifth transmembrane segment of the receptor were the positions for the formation of hydrogen bonds. It is possible to utilize the immobilized receptor to determine the mechanism of drug–receptor interactions.

Metabolomic analysis is an important molecular phenotyping method for understanding plant ecotypic variations. Here, we systematically characterized the metabolomic variations associated with five Chinese cultivars of tree peony (Paeonia suffruticosaAndrews) using high performance liquid chromatography-mass spectrometry (HPLC-MS) and multivariate data analysis. Our results indicated that the metabolite profile of the root bark in tree peony was largely dominated by 5 primary metabolites and 41 secondary ones including 7 phenolics, 7 flavonoids, 16 monoterpene glycosides and 11 acetophenones. The distribution of these secondary metabolites varied in the different tree peony cultivars. Some secondary metabolites, such as galloyl glucoses, procyanidins, mudanpiosides and acetophenones, will become the novel and potential chemotaxonomic markers to differentiate tree peony cultivars when the conventional classification methods are not practicable. These results demonstrated that HPLC-MS based metabolomics was an effective tool for the classification of phenotypic cultivars and provided novel and potential chemotaxonomic characteristics of tree peony.

Forced swimming in cold water causes physiological and psychological stress that leads to altered biochemical homeostasis and neurobehavioral responses. In this study, plasma and urinary metabolites in Sprague-Dawley (SD) rats subjected to cold water forced swimming stress (CWFSS) were characterized using NMR in conjunction with multivariate data analysis. Metabolic analysis demonstrated that decreased levels of lipoprotein and increased levels of O-acetyl glycoprotein, glucose, lactate, pyruvate, creatine, citrate, succinate and amino acids including phenylalanine, tyrosine, glutamate, valine, isoleucine, alanine and lysine in plasma were observed in response to CWFSS. Moreover, the biochemical response to CWFSS as determined from NMR analysis of urine was characterized by an elevation of gut microbiota-related metabolites including phenylacetylglycine, 4-cresol glucuronide and indoxyl sulfate. These results suggest that CWFSS-induced metabolic perturbations were involved in the disruption of amino acid and energy metabolism as well as the alteration of gut microbiota function. This study will enhance the current knowledge of stress-induced diseases and aid in the early diagnosis of metabolic disorders in humans.

Polycyclic musks are widely used for cosmetics and other personal care and household cleaning products. The occurrence and removal of two representative polycyclic musks, galaxolide (HHCB) and tonalide (AHTN) were investigated in three different processes of two sewage treatment plants (STPs) in Xi’an, China. The samples were preconcentrated by solid phase extraction procedure and analyzed using a gas chromatography mass spectrometry (GC/MS) by a modified procedure. The HHCB was in the range of 82.8 to 182.5 ng·L−1in the influents and 22.6 to 103.9 ng·L−1in the effluents. The AHTN ranged from 11.0 to 19.3 ng·L−1in the influents and 2.2 to 8.8 ng·L−1in the effluents. The removal efficiency of the two musks varied in the ranges of 43.1%–70.4% for HHCB and 54.2%–84.4% for AHTN. Concentrations of the two musks in aqueous phase of three processes slightly increased along the primary process, and significantly removed during the biologic treatment processes, revealing that the selected musks could be remarkably removed in varied activated sludge processes. Advanced processes of activated sludge did not show a significant superiority on selected musk removal compared to the conventional process. The selected musk removal mainly resulted from the adsorption function of activated sludge. There was no significant change of HHCB/AHTN ratios along the treatment flow, indicating that each sewage treatment structure had a similar removal efficiency for the two musks.Polycyclic musks are widely used for cosmetics and other personal care and household cleaning products. The occurrence and removal of two representative polycyclic musks, galaxolide (HHCB) and tonalide (AHTN) were investigated in three different processes of two sewage treatment plants (STPs) in Xi’an, China. The samples were preconcentrated by solid phase extraction procedure and analyzed using a gas chromatography mass spectrometry (GC/MS) by a modified procedure. The HHCB was in the range of 82.8 to 182.5 ng·L−1in the influents and 22.6 to 103.9 ng·L−1in the effluents. The AHTN ranged from 11.0 to 19.3 ng·L−1in the influents and 2.2 to 8.8 ng·L−1in the effluents. The removal efficiency of the two musks varied in the ranges of 43.1%–70.4% for HHCB and 54.2%–84.4% for AHTN. Concentrations of the two musks in aqueous phase of three processes slightly increased along the primary process, and significantly removed during the biologic treatment processes, revealing that the selected musks could be remarkably removed in varied activated sludge processes. Advanced processes of activated sludge did not show a significant superiority on selected musk removal compared to the conventional process. The selected musk removal mainly resulted from the adsorption function of activated sludge. There was no significant change of HHCB/AHTN ratios along the treatment flow, indicating that each sewage treatment structure had a similar removal efficiency for the two musks.

A polymerized film of new coccine was deposited on a carbon paste electrode (CPE) by an electropolymerization technique. Electrochemical characterization of the modified electrode was investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The poly(new coccine) modified CPE exhibited excellent electrocatalytic activity towards the oxidation of dopamine (DA), acetaminophenol (AP) and tryptophan (Trp) simultaneously. Well defined and separated oxidation peaks were observed by CV. Linear calibration plots for the oxidation of DA, AP and Trp were obtained in the range of 0.7–200 μM for DA, 1.5–120 μM for AP, and 0.6–50 μM for Trp. Detection limits of DA, AP and Trp were found to be 0.2, 0.3 and 0.2 μM, respectively. With good selectivity and sensitivity, the present method has been successfully applied to the determination of DA, AP and Trp in pharmaceutical samples.

Indocyanine green (ICG) is a conventional dye that can be used in clinical near-infrared (NIR) imaging, and it is also an effective light absorber for laser-mediated photothermal therapy. However, applications of ICG were limited due to its fast degradation in aqueous media and quick clearance from the body. Herein, an ICG-containing nanostructure, ICG-PL-PEG, was developed for photothermal therapy, which was self-assembled by ICG and phospholipid-polyethylene glycol (PL-PEG). Our in vitroand in vivoexperiments demonstrated that ICG-PL-PEG suspension was more efficient in producing a NIR-dependent temperature increase than ICG alone, due to the increase of ICG monomers from the addition of PL-PEG to match the central wavelength of the 808 nm laser. When conjugated with integrin αvβ3monoclonal antibody (mAb), ICG-PL-PEG could be selectively internalized and retained in target tumor cells. Irradiation of an 808 nm laser after intravenous administration of ICG-PL-PEG-mAb resulted in tumor suppression in mice, while ICG alone had only limited effect. This is the first time an ICG-containing nanostructure has been used through systemic administration to achieve an efficient in vivophotothermal effect for cancer treatment. Therefore, ICG-PL-PEG could be used as a fluorescent marker as well as a light-absorber for imaging-guided photothermal therapy. All the components of ICG-PL-PEG have been approved for human use. Therefore, this unique ICG-containing nanostructure has great potential in clinical applications.

Adrenergic receptors (ARs) are members of the super family of G protein-coupled receptors (GPCRs). A large number of small molecular drugs performed their actions on ARs. In this study, two subtypes of ARs affinity chromatographic models have been constructed for investigating the interactions between small molecular compounds and the α- and β-AR subtypes. The α-ARs were obtained from HEK 293 cells stably transfected human α-ARs on the membrane and the β-ARs were obtained from lung tissues of rabbits. ARs were purified and immobilized on the surface of macro-pore silica gel by covalent bonds. Then the gel was packed into a stainless steel column (4.6 × 50 mm). Binding abilities between small molecules and immobilized ARs were determined by on-line chromatographic technologies. Preliminary on-line binding studies employing frontal chromatographic techniques were conducted with the known α-AR agonist (norepinephrine, NE) and β-AR antagonist (propranolo). Calculated association constants (Ka) and binding sites (mLtot) values for NE on immobilized α-AR were 0.9 × 104L mol−1and 5.5 × 10−7mol L−1, and on immobilized β-AR were 0.2 × 104L mol−1and 3.3 × 10−7mol L−1, respectively. Kaand mLtotvalues for propranolol on immobilized α-AR were 1.1 × 103L mol−1and 1.0 × 10−7mol L−1, and on immobilized β-AR were 2.5 × 104L mol−1and 5.0 × 10−7mol L−1, respectively. Above association values were obviously different, but the changes of their laws were comparatively unanimous: there was stronger binding between small molecular compounds and their immobilized target ARs. The conclusions indicated that the immobilized ARs stationary phases can be used to assess the binding affinities of compounds and screen possible active compounds qualitatively. In addition, this study represented an example of using immobilized subtype ARs in a chromatographic system.

Fatigue is believed to be a major contributory factor to occupational injuries in machine operators. The development of accurate and usable techniques to measure operator fatigue is therefore important. In this study, we used a novel method based on surface electromyography (sEMG) of the biceps brachii and the Borg scale to evaluate local muscle fatigue in the upper limb after isometric muscle action. Thirteen young males performed isometric actions with the upper limb at different force levels. sEMG activities of the biceps brachii were recorded during the actions. Borg scales were used to evaluate the subjective sensation of local fatigue of the biceps brachii after the actions. sEMG activities were analyzed using the one-third band octave method, and an equation to determine the degree of fatigue was derived based on the relationship between the variable and the Borg scale. The results showed that the relationship could be expressed by a conic curve, and could be used to evaluate muscle fatigue during machine operation.

Nonsynonymous single-nucleotide polymorphisms (nsSNPs) in cytochrome P450 (P450) genes may affect drug metabolism and drug-drug interactions (DDIs), potentially leading to adverse drug reactions. Functional characterization of the nsSNPs in P450 genes is important to help us understand the impact of genetic factors on P450-mediated drug metabolism and DDIs. To evaluate the effects of P450 nsSNPs on the metabolism and inhibition potential of a candidate drug, tanshinol borneol ester (DBZ), we obtained and experimentally validated eight yeast-expressed human P450 isoforms and their nsSNP variants and tested DBZ using these recombinant P450 enzymes. The results suggested that CYP2C8 is the major enzyme responsible for DBZ metabolism. In addition, compared with prototypic CYP2C8, the allelic variant, CYP2C8.3, produced a 54% decrease in the intrinsic clearance of DBZ. The inhibitory potency of DBZ toward CYP3A4 was greater than that toward other P450 isoforms, including CYP1A2, CYP2C8, CYP2C9, CYP2C19, and CYP2D6. Moreover, the inhibitory potency toward three CYP3A4 allelic variants, CYP3A4.2, CYP3A4.12, and CYP3A4.16, was reduced 2- to 10-fold relative to prototype CYP3A4. These results provide useful information for understanding the influence of P450 genetic polymorphisms on DBZ metabolism and may help to design future clinical trials of DBZ. Our results suggest applications for in vitro P450 assays both for basic research in pharmacogenomics and for drug development.

Tanshinol borneol ester (DBZ) is an experimental drug that exhibits efficacious anti-ischemic activity in rats. Although the specific metabolic properties of DBZ are still unknown, previous studies in rats have strongly suggested that DBZ is extensively metabolized after administration and thus probably acts as a prodrug. Because the enzymes involved in drug metabolism differ between humans and rats in isoform composition, expression, and catalytic activity, the pharmacokinetics of the same drug in the two species may also differ. Establishing the differences between DBZ metabolism in human and rat liver microsomes can help to predict DBZ pharmacokinetics in humans and aid in the assessment of its potential efficacy, toxicity, and mechanism of action. In this work, the microsomal stabilities and metabolic kinetics of DBZ in rat and human liver microsomes were compared, and the DBZ metabolites generated in human liver microsomes (HLMs) were identified. The results suggested that DBZ is more stable in HLMs than in rat liver microsomes (RLMs). The intrinsic clearance of DBZ in HLMs was 10- to 17-fold lower than that in RLMs, which indicates lower DBZ clearance in humans. Metabolite analysis suggested that DBZ is hydroxylated by liver microsomal enzymes, resulting in the production of five metabolites. Although the kinetics of metabolite formation in HLMs and RLMs were different, the same metabolites were generated, indicating that the same metabolic pathway is present in both species. The results obtained from this work suggest the potential for DBZ to act as a prodrug with anti-ischemic activity in humans.

A new chelating compound has been developed for use in the immobilized metal affinity chromatographic (IMAC) separation of proteins. The bidentate ligand, α‐amino phenylalanine tetrazole, 4, was synthesizedvia a five‐step synthesis fromN‐fluorenylmethoxycarbonyl phenylalanine and then immobilized onto silica through the epoxide coupling procedure. The binding behavior of the resulting IMAC sorbent, following chelation with Zn2+to a density of 183 μmol Zn2+ions/g silica, was characterized by the retention of proteins in the pH range of 5.0–8.0, and by the adsorption behavior of lysozyme with frontal chromatography at pH 6.0 and 8.0. The prepared column showed the separation ability to four test proteins and the retention time of these proteins increased with an increase in pH. From the derived isotherms, the adsorption capacity,qm, for the binding of lysozyme to immobilized Zn2+‐α‐amino phenylalanine tetrazole–silica was found to be 1.21 μmol/g at pH 6.0 and 1.20 μmol/g sorbent at pH 8.0, respectively, whilst the dissociation constants KD at these pH values were 5.22×10–6 and 3.49×10–6 M, respectively, indicating that the lysozyme was retained more stable under alkaline conditions, although the binding capacity in terms of micromole proteinper gram sorbent remained essentially unchanged.

Item response theory models are measurement models for categorical responses. Traditionally, the models are used in educational testing, where responses to test items can be viewed as indirect measures of latent ability. The test items are scored either dichotomously (correct–incorrect) or by using an ordinal scale (a grade from poor to excellent). Item response models also apply equally for measurement of other latent traits. Here we describe the one- and two-parameter logit models for dichotomous items, the partial-credit and rating scale models for ordinal items, and an extension of these models where the latent variable is regressed on explanatory variables. We show how these models can be expressed as generalized linear latent and mixed models and fitted by using the user-written command gllamm.

Abstract: Musculoskeletal tissues regeneration requires rapid expansion of seeding cells both in vitro and in vivo while maintaining their multilineage differentiation ability. Human adipose-derived stem cells (ASCs) are considered to contain multipotent mesenchymal stem cells. Monolayer cultures of human ASCs were isolated from human lipoaspirates and passaged 3 times and then infected with replication-incompetent adenoviral vectors carrying green fluorescent protein (Ad/GFP) genes. Then, Ad/GFP infected human ASCs were transferred to osteogenic, chondrogenic, adipogenic, and myogenic medium. The morphological characterization of induced cells was observed using phase-contrast microscopy and fluorescence microscopy. The expression of marker proteins or genes was measured by immunocytochemical and RT-PCR analysis. Osteopontin (OPN), and osteocalcin (OCN) were positive in osteogenic lineages, aggrecan and SOX9 were positive in chondrogenic ones, peroxisome proliferator-activated receptor (PPAR-γ2) and lipoprotein lipase (LPL) were positive in adipogenic ones, and myogenin and myod1 was positive in myogenic ones. At the same time, the results of fluorescence microscopic imaging proved that the high level of GFP expression during ASCs differentiation maintained stable nearly 2 months. So the exogenous GFP and multilineage potential of human ASCs had no severe influences on each other. Since the human ASCs can be easily obtained and abundant, it is proposed that they may be promising candidate cells for further studies on tissue engineering. Imaging with expression of GFP facilitates the research on ASCs physiological behavior and application in tissue engineering during differentiation both in vitro and in vivo.

Abstract: Functional engineering of musculoskeletal tissues generally involves rapid expansion of progenitor cells in vitro while retaining their potential for further differentiation and then induction in specific culture conditions. The autologous adipose-derived stromal cells (ASCs) are considered to contain pluripotent mesenchymal stem cells. Imaging with expression of green fluorescent protein (GFP) facilitates the detailed research on ASCs physiological behavior during differentiation into a variety of cell lineages both in vitro and in vivo. In this study, we aimed to confirm the trans-germ plasticity of homogeneously marked ASCs from GFP transgenic mice. Simultaneously, the term and intensity of GFP expression in ASCs were also focused on during variant inductions, when cells were incubated with multiple growth factors and adjuvant. ASCs were harvested from inguinal fat pads of transgenic nude mice, passaged 3 times in monolayer cultures, and then transferred to osteogenic, adipogenic, neurogenic, and myogenic medium. The morphological characterization of inductive cells was observed using phase-contrast microscopy and histological staining such as alizarin red for mineralization nodules and oil red O for lipid accumulation. The expression of marker genes or proteins was measured using RT-PCR and immunocytochemical analysis. Collagen type I, osteopontin (OPN), and osteocalcin (OCN) were positive in osteogenic lineages, peroxisome proliferator-activated receptor(PPAR)-γ2 and lipoprotein lipase (LPL) were positive in adipogenic ones, glial fibrillary acidic protein (GFAP) and neuron-specific enolase (NSE) were positive in neurogenic ones, and α-smooth muscle actin (α-SMA) was positive in myogenic ones. Moreover, the results of fluorescence microscopic imaging suggested that there was no significant decline of GFP expression during ASCs differentiation and the level of GFP maintained stable till differentiated ASCs showed apoptotic phenotype. So the endogenous GFP and multilineage potential of transgenic ASCs had no influences on each other. Since the population of GFP ASCs can be easily identified, it is proposed that they may be promising candidate seed cells for further studies on ASCs tissue engineering, especially the study on engineered tissues formed in vivo.

A rapid and sensitive chemiluminescence (CL) method using flow injection analysis was described for the determination of three catecholamines: dopamine, adrenaline and dobutamine, based on their greatly enhancing effects on the CL reaction of luminol-potassium periodate in basic solutions. Under the optimized conditions, the calibration graphs relating the increase of CL intensity to the concentration of the analytes were linear. The present method allows for the determination of dopamine, adrenaline, and dobutamine over the range of 1.0 × 10-10- 1.0 × 10-7g/ml. The relative standard deviations for measurements (n= 11) of dopamine, adrenaline and dobutamine were 2.9, 2.3 and 1.8% when the concentrations of three catecholamines were at 1.0 × 10-9g/ml, respectively. The detection limits of the method were 2.0 × 10-11g/ml dopamine, 1.0 × 10-11g/ml adrenaline and 4.0 × 10-11g/ml dobutamine. The method was successfully applied to the determination of three catecholamines in pharmaceutical samples and blood plasma.

Human adipose tissue is a viable source of mesenchymal stem cells (MSCs) with wide differentiation potential for musculoskeletal tissue engineering research. The stem cell population, termed processed lipoaspirate (PLA) cells, can be isolated from human lipoaspirates and expanded in vitroeasily. This study was to determine molecular and cellular characterization of PLA cells during chondrogenic differentiation in vitroand cartilage formation in vivo. When cultured in vitrowith chondrogenic medium as monolayers in high density, they could be induced toward the chondrogenic lineages. To determine their ability of cartilage formation in vivo, the induced cells in alginate gel were implanted in nude mice subcutaneously for up to 20 weeks. Histological and immunohistochemical analysis of the induced cells and retrieved specimens from nude mice at various intervals showed obviously cartilaginous phenotype with positive staining of specific extracellular matrix (ECM). Correlatively, results of RT‐PCR and Western Blot confirmed the expression of characteristic molecules during chondrogenic differentiation namely collagen type II, SOX9, cartilage oligomeric protein (COMP) and the cartilage‐specific proteoglycan aggrecan. Meanwhile, there was low level synthesis of collagen type X and decreasing production of collagen type I during induction in vitroand formation of cartilaginous tissue in vivo. These cells induced to form engineered cartilage can maintain the stable phenotype and indicate no sign of hypertrophy in 20 weeks in vivo, however, when they cultured as monolayers, they showed prehypertrophic alteration in late stage about 10 weeks after induction. Therefore, it is suggested that human adipose tissue may represent a novel plentiful source of multipotential stem cells capable of undergoing chondrogenesis and forming engineered cartilage.

Abstract Pluripotent stem cells within the adipose stromal compartment, termed adipose-derived stromal cells (ASCs), have the potential to differentiate into a variety of cell lineages both in vitro and in vivo. Imaging with expression of exogenous or endogenous green fluorescent protein (GFP) reporters facilitates the detailed research on ASCs’ physiological behavior during differentiation in vivo. This study was aimed to confirm whether ASCs expressing GFP still could be induced to chondrogenesis, and to compare the expression of exogenous or endogenous GFP in ASCs during chondrogenic differentiation. ASCs were harvested from inguinal fat pads of normal nude mice or GFP transgenic mice. Monolayer cultures of ASCs from normal mice were passaged three times and then infected with replication-incompetent adenoviral vectors carrying GFP genes. Allowed to recover for 5 days, Ad/GFP infected ASCs were transferred to chondrogenic medium as well as the ASCs from transgenic mice cultured in vitro over the same passages. The level of GFP in transgenic ASCs maintained stable till 3 months after chondrogenic induction. Whereas, high level of GFP expression in Ad/GFP infected ASCs could last for only 8 weeks and then declined stepwise. Important cartilaginous molecules such as SOX9, collagen type I, collagen type II, aggrecan, collagen type X were assessed using immunocytochemistry, RT-PCR, and Western Blot. The results indicated that no matter the GFP was exogenous or endogenous, it did not influence the chondrogenic potential of ASCs in comparison with the normal controls. Moreover, chondrogenic lineages from ASCs also underwent phenotypic modulation called dedifferentiation as a result of long-term culture in monolayers similar to normal chondrocytes.

The soil state (e.g., temperature and moisture) in a mesoscale numerical prediction model is typically initialized by reanalysis or analysis data that may be subject to large bias. Such bias may lead to unrealistic land‐atmosphere interactions. This study shows that the Climate Forecast System Reanalysis (CFSR) dramatically underestimates soil temperature and overestimates soil moisture over most parts of China in the first (0–10 cm) and second (10–25 cm) soil layers compared to in situ observations in July 2013. A correction based on the global optimal dual kriging is employed to correct CFSR bias in soil temperature and moisture using in situ observations. To investigate the impacts of the corrected soil state on model forecasts, two numerical model simulations—a control run with CFSR soil state and a disturbed run with the corrected soil state—were conducted using the Weather Research and Forecasting model. All the simulations are initiated 4 times per day and run 48 h. Model results show that the corrected soil state, for example, warmer and drier surface over the most parts of China, can enhance evaporation over wet regions, which changes the overlying atmospheric temperature and moisture. The changes of the lifting condensation level, level of free convection, and water transport due to corrected soil state favor precipitation over wet regions, while prohibiting precipitation over dry regions. Moreover, diagnoses indicate that the remote moisture flux convergence plays a dominant role in the precipitation changes over the wet regions. Both soil temperature and soil moisture are corrected to investigate the impacts of the corrected soil initial state on the atmospheric processesMultiple processes associated with the East Asian summer monsoon precipitation are diagnosed, showing the higher rain possibility over the wet regions and lower possibility over the other regions due to the soil initial state's impactsThe simple soil initial state correction delivered in this paper has shown some practical value over regions of dense observations

Fe2O3nanoparticles/reduced graphene oxide (Fe2O3/rGO) nanocomposites were synthesized for enhanced electrochemical sensing of N2H4. Fe2O3/rGO nanocomposites were synthesized through a green and facile one-step hydrothermal approach by using L-lysine as both reductant and hydrolysis-controlling agent. Then, the nanocomposites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction spectroscopy (XRD), energy-dispersive X-ray spectrum (EDS), fourier transform infrared spectroscopy (FTIR) and electrochemical techniques. SEM and TEM observations revealed that large numbers of Fe2O3nanoparticles with spherical morphologies were distributed on the surface of rGO sheets, which made the sensor based on Fe2O3/rGO exhibited an excellent performance toward N2H4detection with a wide linear range of 0.8 μM to 1.27 mM, a high sensitivity of 525.3 μA mM−1cm−2and a low detection limit of 0.09 μM (S/N = 3). Therefore, the facile approach and excellent experimental results indicated that Fe2O3/rGO nanocomposites can be applied as a promising type of sensing material for electrochemical detection of N2H4.

The nanocomposites of hollow and porous palladium nanospheres (Pd-HPs) supported on reduced graphene oxide (rGO) were prepared and then applied for electrochemical sensing of hydrogen peroxide (H2O2). Pd-HPs/rGO nanocomposites were synthesized for the first time through a facile one-pot hydrothermal route by using urea as the structure directing agent and reductant. The morphology and composition of the nanocomposites were characterized using transmission electron microscope (TEM), fourier transform infrared spectroscopy and energy-dispersive X-ray spectrum. TEM observations revealed that the as-synthesized Pd-HPs/rGO nanocomposites exhibited a sphere-shaped hollow and porous structure. The electrochemical investigations indicated that Pd-HPs/rGO nanocomposites exhibited excellent electrocatalytic performance toward H2O2reduction with a linear range from 50.0 μM to 9.25 mM, a high sensitivity of 216.2 μA mM−1cm−2and a low detection limit of 9.5 μM.