Methyl-terminated graphite carbon nitride with regulatable local charge redistribution for ultra-high photocatalytic hydrogen production and antibiotic degradation.

Intramolecular-tailored graphite carbon nitride (g-CN) has great potential to greatly optimize the photo-response performance and carrier separation ability, but exquisite molecular structure engineering is still challenging. Firstly, a series of oxygen and terminal methyl moiety co-modified g-CN (CNNx) has been systematically prepared by using N-Hydroxysuccinimide (HOSu) as a novel copolymerized precursor and urea. The density functional theory (DFT) calculations demonstrated that the presence of oxygen can lower the binding energy for the C-C bond to make the terminal modification easier.

Overall analyses of the reactions catalyzed by acetohydroxyacid synthase/acetolactate synthase using a precolumn derivatization-HPLC method.

A precolumn derivatization-HPLC method using 2,4-dinitrophenylhydrazine and 4-nitro-o-phenylenediamine as respective labeling reagents for comprehensive analyses of the reactions catalyzed by acetohydroxyacid synthase (AHAS)/acetolactate synthase (ALS) is developed and evaluated in this research. Comparison with the classic Bauerle' UV assay which can analyze the enzymes only through measurement of acetoin production, the HPLC method shows advantages because it can analyze the enzymes not only via determination of consumption of the substrate pyruvate, but also via measurement of formation of the products including acetoin, 2,3-butanedione, and acetaldehyde in the enzymatic reactions. Thus the results deduced from the HPLC method can reflect the trait of each enzyme in a more precise manner.

Characterization of acetolactate decarboxylase of Streptococcus thermophilus and its stereoselectivity in decarboxylation of α-hydroxy-β-ketoacids.

Acetolactate decarboxylase (ALDC) is a well-characterized catabolic enzyme catalyzes the decarboxylation of (±)-acetolactate to produce a single product, (R)-acetoin. It can also convert other racemic α-hydroxy-β-ketoacids to corresponding α -hydroxyketones in R-configuration. In this work, we prepared ALDC of Streptococcus thermophilus (StALDC) and explored its stereoselectivity on different substrates.

A Comparative Study of Two Tube Feeding Methods in Patients with Dysphagia After Stroke: A Randomized Controlled Trial.

Background: Dysphagia is a common symptom seen in stroke patients, it not only affects patients' nutrition supply, but also causes aspiration pneumonia. To solve the problem of nutritional support for patients with dysphagia after stroke, nasogastric tubes are routinely indwelling to provide nutrition in China. However, this feeding method sometimes causes food reflux, aspiration, pneumonia, and often affects the patients' comfort and self-image acceptance.

Inhibitory Activity of Plant Essential Oils against 1-Deoxy-d-xylulose-5-phosphate reductoisomerase.

The rate-limiting enzyme of the 2-methyl-d-erythritol-4-phosphate (MEP) terpenoid biosynthetic pathway, 1-deoxy-d-xylulose-5-phosphate reductoisomerase (DXR), provides the perfect target for screening new antibacterial substances. In this study, we tested the DXR inhibitory effect of 35 plant essential oils (EOs), which have long been recognized for their antimicrobial properties. The results show that the EOs of (ZB), (ST), (TQ), (OV), and (EC) displayed weak to medium inhibitory activity against DXR, with IC values of 78 μg/mL, 65 μg/mL, 59 μg/mL, 48 μg/mL, and 37 μg/mL, respectively.

Geniposide and Gentiopicroside Suppress Hepatic Gluconeogenesis via Regulation of AKT-FOXO1 Pathway.

Background: Hepatic gluconeogenesis plays an important role in regulating fasting plasma glucose levels and is a target of anti-diabetic drugs. Several kinds of iridoid glucosides exhibit hypoglycemic effect, whereas the mechanism was not clear.

Aim Of The Study: In this study, the effects of geniposide and gentiopicroside, two natural iridoid glucosides, on hepatic gluconeogenesis were investigated.

[Determination of diacetyl in liquors by high performance liquid chromatography coupled with precolumn derivatization using 3,3'-diaminobenzidine].

A method was developed for the determination of diacetyl in liquors by high performance liquid chromatography-ultraviolet (HPLC-UV) coupled with precolumn derivatization using derivatization reagent 3,3'-diaminobenzidine (DAB). Diacetyl reacted with DAB at room temperature for 10 min. Then the separation was carried out on a high performance liquid chromatograph equipped with a diode array detector (DAD).

Antimicrobial mechanism of epigallocatechin gallate and gallocatechin gallate: They target 1-deoxy-d-xylulose 5-phosphate reductoisomerase, the key enzyme of the MEP terpenoid biosynthetic pathway.

The catechins EGCG and GCG show a variety of pharmacological activities, especially an antibacterial capacity, but their modes of antimicrobial action have not been fully elucidated. 1-Deoxy-d-xylulose 5-phosphate reductoisomerase (DXR), the first key enzyme in the MEP pathway for terpenoid biosynthesis, is a recently validated antimicrobial target. In order to disclose the antibacterial mechanism of EGCG and GCG, the DXR inhibitory activity of them was investigated in this study.

Determination of Diacetyl in Beer by a Precolumn Derivatization-HPLC-UV Method Using 4-(2,3-Dimethyl-6-quinoxalinyl)-1,2-benzenediamine as a Derivatizing Reagent.

Diacetyl is an important flavoring compound in many foods, especially in beer. In the present study, we developed and validated a new precolumn derivatization HPLC-UV method for the determination of diacetyl using 4-(2,3-dimethyl-6-quinoxalinyl)-1,2-benzenediamine as a novel derivatizing reagent. After derivatization with the reagent at a pH value 4.

Antimicrobial mechanism of theaflavins: They target 1-deoxy-D-xylulose 5-phosphate reductoisomerase, the key enzyme of the MEP terpenoid biosynthetic pathway.

1-Deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) is the first committed enzyme in the 2-methyl-D-erythritol 4-phosphate (MEP) terpenoid biosynthetic pathway and is also a validated antimicrobial target. Theaflavins, which are polyphenolic compounds isolated from fermented tea, possess a wide range of pharmacological activities, especially an antibacterial effect, but little has been reported on their modes of antimicrobial action. To uncover the antibacterial mechanism of theaflavins and to seek new DXR inhibitors from natural sources, the DXR inhibitory activity of theaflavins were investigated in this study.

Inhibition of green tea and the catechins against 1-deoxy-d-xylulose 5-phosphate reductoisomerase, the key enzyme of the MEP terpenoid biosynthetic pathway.

1-Deoxy-d-xylulose 5-phosphate reductoisomerase (DXR) is the first committed enzyme in the MEP terpenoid biosynthetic pathway and also a validated antimicrobial target. Green tea which is rich in polyphenolic components such as the catechins, possesses a plenty of pharmacological activities, in particular an antibacterial effect. To uncover the antibacterial mechanism of green tea and to seek new DXR inhibitors from natural sources, the DXR inhibitory activity of green tea and its main antimicrobial catechins were investigated in this study.

Branched-chain amino acids attenuate early kidney injury in diabetic rats.

Diabetic nephropathy (DN) is the most severe diabetic microvascular complication. The pathogenesis of diabetic nephropathy is complex, and oxidative stress plays an important role in the development of diabetic nephropathy. Elevated reactive oxygen species (ROS) levels activate various signaling pathways and influence the activities of transforming growth factor-β (TGF-β) and matrix metalloproteinase-9 (MMP-9), which contributes to glomerular hypertrophy.

Facilely synthesized H-mordenite nanosheet assembly for carbonylation of dimethyl ether.

Hard coke blockage of micropores of acidic zeolites generally causes serious catalytic deactivation for many chemical processes. Herein, we report a facile method to synthesize H-mordenite nanosheet assemblies without using any template agent. The assemblies exhibit the high catalytic activity for carbonylation of dimethyl ether because of their large quantity of framework Brønsted acids.

Tuning interactions between zeolite and supported metal by physical-sputtering to achieve higher catalytic performances.

To substitute for petroleum, Fischer-Tropsch synthesis (FTS) is an environmentally benign process to produce synthetic diesel (n-paraffin) from syngas. Industrially, the synthetic gasoline (iso-paraffin) can be produced with a FTS process followed by isomerization and hydrocracking processes over solid-acid catalysts. Herein, we demonstrate a cobalt nano-catalyst synthesized by physical-sputtering method that the metallic cobalt nano-particles homogeneously disperse on the H-ZSM5 zeolite support with weak Metal-Support Interactions (MSI).

NO adsorption behaviors of the MnOx catalysts in lean-burn atmospheres.

NO(x) emission control of lean-burn engines is one of the great challenges in the world. Herein, the MnOx model catalysts with the different calcination temperatures were synthesized to investigate their NO adsorbability for lean-burn exhausts. The transformation from (β-)MnO₂ to (α-)Mn₂O₃ following the increased calcination temperatures was evidenced from the viewpoint of the local atomic level.

[Transdermal delivery of Gentiana macrophylla complex components system under micro-needle conditions].

The purpose of this study is to investigate the transdermal delivery characteristics of Gentiana macrophylla complex components system through different parts of the skin under micro-needles conditions. Two-chamber diffusion cells were used, different parts of isolated skin and micro-needle pretreated isolated mouse skin were applied separately, high performance liquid chromatography (HPLC) similarity evaluation methods were used to evaluate transdermal delivery characteristics of Gentiana macrophylla complex components system on receiving pool and the permeation rate and penetration amount of Gentiopicroside at different parts of mouse skin. In the 24 h, the similarity between receiving fluid which was on passive transdermal delivery and micro-needle transdermal delivery conditions and original fluid were ranged from 83.

Hydrotalcite-derived MnxMg3-xAlO catalysts used for soot combustion, NOx storage and simultaneous soot-NOx removal.

The hydrotalcite-based Mn(x)Mg(3-x)AlO catalysts with different Mn:Mg atomic ratios were synthesized by coprecipitation, and employed for soot combustion, NOx storage and simultaneous soot-NO(x) removal. It is shown that with the increase of Mn content in the hydrotalcite-based Mn(x)Mg(3-x)AlO catalysts the major Mn-related species vary from MnAl(2)O(4) and Mg(2)MnO(4) to Mn(3)O(4) and Mn(2)O(3). The catalyst Mn(1.

A highly sensitive hexachromium monitor using water core optical fiber with UV LED.

A simply structured, cheap hexachromium monitor was developed. The monitor is based on UV/VIS absorption technique. A 2-m long water core optical fiber was employed as a long path length sample cell and a UV light emitting diode (LED) was used as a light source.