Novel efficient procedure for biodiesel synthesis from waste oils with high acid value using 1-sulfobutyl-3-methylimidazolium hydrosulfate ionic liquid as the catalyst

Preparation of biodiesel from waste oils containing 72% of free fatty acids catalyzed by a novel Br?nsted acidic ionic liquid 1-sulfobutyl-3-methylimidazolium hydrosulfate([BHSO_3MIM][HSO_4]) was systematically investigated.The optimum molar ratio of methanol to waste oils,catalyst amount,reaction temperature and reaction time were 8/1,10%(based on the mass of waste oils),140°C and 6 h,respectively,under which the obtained yield of biodiesel reached 94.9%.Also,[BHSO_3MIM][HSO_4] as a catalyst still retained around 97% of its original catalytic activity after successive re-use of 5 batches(6 h per batch),showing the excellent operational stability.Moreover,the acidic IL [BHSO_3MIM][HSO_4] was able to ef ficiently catalyze conversions of waste oils with different amounts of FFAs(free fatty acids) into biodiesel,and showed tremendous application potential.Therefore,an ef ficient and environmentally friendly catalyst is provided for the synthesis of biodiesel from waste oils with high acid value.

Review and Comprehensive Analysis of Composition and Origin of High Acidity Crude Oils

High acidity crude oils have an advantage over normal oils in terms of their price,but can cause corrosion and refinery problems.They are the so-called opportunity crudes and likely to be important reserved resources in the 21st century.Researches on high acidity crude oils are becoming more and more profound.Based on the existing research achievements,this article has given an overview of the chemical composition and acid distribution of high acidity oils,and also analyzed their origin types and potential influence factors.

Vanadium(Ⅳ)solvent extraction enhancement in high acidity using di-(2-ethylhexyl)phosphoric acid with[Cl^(-)]present:an experimental and theoretical study

Separation of vanadium from black shale leaching solution at low pH is very meaningful,which can effectively avoid the generation of alkali neutralization slag and the resulting vanadium loss.In this study,coordination mechanism of vanadium in acid leaching solution at low pH was investigated with the intervention of chloride ions.Under the conditions of pH 0.8,di-(2-ethylhexyl)phosphoric acid concentration of 20%,phase ratio of 1:2,and extraction time of 8 min,the vanadium extraction could reach 80.00%.The Fourier transform infrared and electrospray ionization results reveal that,despite the fact that the chloride ion in the leachate could significantly promote vanadium extraction,the chloride ion does not enter the organic phase,indicating an intriguing phenomenon.Among Cl^(-)-V,SO_(4)^(2-)-V,and H_(2)O-V,the V-Cl bond is longer and the potential difference between coordinate ions and vanadium is smaller.Therefore,Vo^(2+)gets easily desorbed with chloride ions and enter the organic phase.At the same time,the hydrogen ions of di-(2-ethylhexyl)phosphoric acid also enter the water phase more easily,which reduces the pH required for the extraction reaction.

Preparation of high acidity coefficient slag wool fiber with blast furnace slag and modifying agents

Preparation of high acidity coefficient slag wool fiber with molten slag and modifying agents is considered to be a positive approach for value-added utilization of blast furnace slag. In order to achieve the multi-purposes of fiber-forming, energy saving, and waste heat recovery, the modifying agents that can improve the acidity coefficient of slag effectively, economically, and environmentally were investigated. Three agents with different acidity coefficients were adopted to modify slag and manufacture wool fibers. The effect of agent and slag proportion on the melting temperature and viscosity of molten slag was studied at a fixed acidity coefficient of 1.8 and 2.0. The results indicate that the sample modified with high acidity coefficient agent and high slag proportion has lower melting temperature and viscosity. The effect of agent and slag temperature on the fiber diameter was also investigated when the acidity coefficient of slag is 2.0. At a fixed slag proportion of 50 wt.%, the mean diameter decreases with increasing temperature and decreasing viscosity coefficient. Besides, the temperature drops caused by the addition of agents and energy consumption of samples for heating the slag were also analyzed.

Clinical Significance of Serum Uric Acid Combined with Cystatin C Detection in Patients with Different Levels of Hypertension with High Risk Degree and Above

Objective: To explore the clinical significance of serum uric acid combined with cystatin C detection in high risk degree of hypertension of different grades. Methods: The patients who were treated in the Department of Cardiovascular Medicine of our hospital from January to December 2022 were selected as the study subjects, and the high risk and extremely high risk groups of grade I, II and III hypertension were selected for comparative analysis to explore their clinical significance. Results: There was a statistically significant difference in the number of patients with extremely high risk of grade II hypertension between men and women (P 0.05), which showed that there was no specificity in the concentration detection of serum uric acid and cystatin C in different grades of hypertension;there was no significant difference in serum uric acid concentration between grade II and grade III of hypertension with high risk grade and cystatin C concentration between grade I and grade III of hypertension with high risk grade (P > 0.05), but there was significant difference in the concentration detection of serum uric acid and cystatin C between the other groups (P < 0.05), which indicates that the detection of serum uric acid and cystatin C has important clinical significance in the high risk degree of hypertension. Conclusion: In the comparison of the detection of blood uric acid and cystatin C in different levels of hypertension with extremely high risk, the difference of cystatin C in grade I and grade III was not statistically significant, and the rest were statistically significant;therefore, the detection of serum uric acid and cystatin C can provide reliable laboratory data for clinical diagnosis and treatment of the extremely high risk degree of different levels of hypertension.

Improvement of three popular Indian groundnut varieties for foliar disease resistance and high oleic acid using SSR markers and SNP array in marker-assisted backcrossing

Foliar fungal diseases(rust and late leaf spot)incur large yield losses,in addition to the deterioration of fodder quality in groundnut worldwide.High oleic acid has emerged as a key market trait in groundnut,as it increases the shelf life of the produce/products in addition to providing health benefits to consumers.Marker-assisted backcrossing(MABC)is the most successful approach to introgressing or pyramiding one or more traits using traitlinked markers.We used MABC to improve three popular Indian cultivars(GJG 9,GG 20,and GJGHPS 1)for foliar disease resistance(FDR)and high oleic acid content.A total of 22 BC3F4 and 30 BC2F4 introgression lines(ILs)for FDR and 46 BC3F4 and 41 BC2F4 ILs for high oleic acid were developed.Recurrent parent genome analysis using the 58 K Axiom_Arachis array identified several lines showing upto 94%of genome recovery among second and third backcross progenies.Phenotyping of these ILs revealed FDR scores comparable to the resistant parent,GPBD 4,and ILs with high(~80%)oleic acid in addition to high genome recovery.These ILs provide further opportunities for pyramiding FDR and high oleic acid in all three genetic backgrounds as well as for conducting multi-location yield trials for further evaluation and release for cultivation in target regions of India.

Chlorogenic Acid Maintains Glucose Homeostasis through Modulating the Expression of SGLT-1,GLUT-2,and PLG in Different Intestinal Segments of Sprague-Dawley Rats Fed a High-Fat Diet

Objective To reveal the effects and related mechanisms of chlorogenic acid(CGA)on intestinal glucose homeostasis.Methods Forty male Sprague-Dawley rats were randomly and equally divided into four groups:normal chow(NC),high-fat diet(HFD),HFD with low-dose CGA(20 mg/kg,HFD-LC),and HFD with high-dose CGA(90 mg/kg,HFD-HC).The oral glucose tolerance test was performed,and fast serum insulin(FSI)was detected using an enzyme-linked immunosorbent assay.The m RNA expression levels of glucose transporters(Sglt-1 and Glut-2)and proglucagon(Plg)in different intestinal segments(the duodenum,jejunum,ileum,and colon)were analyzed using quantitative real-time polymerase chain reaction.SGLT-1 protein and the morphology of epithelial cells in the duodenum and jejunum was localized by using immunofluorescence.Results At both doses,CGA ameliorated the HFD-induced body weight gain,maintained FSI,and increased postprandial 30-min glucagon-like peptide 1 secretion.High-dose CGA inhibited the HFD-induced elevation in Sglt-1 expression.Both CGA doses normalized the HFD-induced downregulation of Glut-2 and elevated the expression of Plg in all four intestinal segments.Conclusion An HFD can cause a glucose metabolism disorder in the rat intestine and affect body glucose homeostasis.CGA can modify intestinal glucose metabolism by regulating the expression of intestinal glucose transporters and Plg,thereby controlling the levels of blood glucose and insulin to maintain glucose homeostasis.

Determination of Organic Acids in Root Exudates by High Performance Liquid Chromatography: I.Development and Assesment of Chromatographic Conditions

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FATTY ACIDS PROFILE IN A HIGH CELL DENSITY CULTURE OF ARACHIDONIC ACID-RICH PARIETOCHLORIS INCISA (TREBOUXIOPHYCEAE,CHLOROPHYTA) EXPOSED TO HIGH PFD

The changes in arachidonic acid (AA) and fatty acids profiles along the growth curve of Parietochloris incisa, a coccoid snow green alga, were studied in a 2.8 cm light-path flat photobioreactor, exposed to strong photon flux density [PFD, 2400 μEmol/(m 2·s)]. Sixteen fatty acids were identified by gas chromatography showing that AA was the dominant fatty acid (33%-41%) followed by linoleic acid (17%-21%). AA content was closely investigated with respect to total fatty acids (TFA), ash free dry weight (AFDW) of cell mass as well as total culture content. These parameters were influenced significantly in a similar manner by culture growth phase, i.e., slightly decreasing in the lag period, gradually increasing in the logarithmic phase, becoming maximal at the early stationary phase, starting to decrease at the late stationary phase, sharply dropping at the decline phase. The increase in AA per culture volume during the logarithmic phase was not only associated with the increase in AFDW but also connected with a corresponding increase in AA/TFA, TFA/AFDW as well as AA/AFDW. The sharp decrease in AA content of the culture during the decline phase was mainly due to the decrease in AA/TFA, TFA/AFDW and AA/AFDW, although AFDW declined only a small extent. Maximal AA concentration, obtained at the early stationary phase, was 900 mg/L culture volume, and the average daily net increase of AA during 9 days logarithmic growth was 1.7 g/(m 2·day). Therefore, harvesting prior to the decline phase in a batch culture, or at steady state in continuous culture mode seems best for high AA production. The latter possibility was also further confirmed by continuous culture with 5 gradients of harvesting rate.

Problems Encountered and Countermeasure Adopted During Processing of Shengli High-sulfur and High-acidity Crude

集中的处理高硫、高酸味粗略贡献了精制企业的油的全面经济好处的改进，但是也导致了粗略的乳化，过程单位的严重腐蚀和环境 protectionissues.The 长周期，过程单位的安全、光滑的操作在最佳的处理线路的选择和一系列技术措施的采纳以后被保证。

Enhanced Acid/Base Catalysis in High Temperature Liquid Water

Two novel and environmentally benign solvent systems, organic acids-ennchea high temperature liquid water （HTLW） and NH3-enriched HTLW, were developed, which can enhance the reaction rate of acid/base-catalyzed organic reactions in HTLW. We investigated the decomposition of fructose in organic acids-enriched HTLW, hydrolysis of cinnamaldehyde and aldol condensation of phenylaldehyde with acetaldehyde in NH3-enriched HTLW. The experimental results demonstrated that organic acids-enriched or NH3-enriched HTLW can greatly accelerate acid/base-catalyzed organic reactions in HTLW.

Study on Brewing Characteristics of High α-acid and High β-acid Hops

[Objectives] Columbus and Tsingtao Flower were selected to brew Ale beer, thereby studying the brewing characteristics of high α-acid and high β-acid content hops. [Methods] The content of diacetyl and bitterness in beer were determined by a spectrophotometer at 335 and 275 nm, respectively. With pH=8.2 as the end point of potentiometric titration, the total acid content in beer was calculated by acid-base titration method, and sensory evaluation for beer was conducted. [Results] The results show that α-acid is an important factor affecting the production and reduction rate of diacetyl in beer. The production and reduction rate of diacetyl in high α-acid hops were lower than those in high β-acid hops; iso-α-acid was the main source of bitterness in beer, and high α-acid hops had more significant bitter value than high β-acid hops; and malt acid compounds and fermentation production were the main source of total acid in beer, and high α-acid and high β-acid hops had a little effect on total acid in beer. In sensory evaluation, high α-acid hops were more effective than high β-acid hops in terms of zest of the mouthfeel, foaming retention and alcohol fragrance, while in clarity, high α-acid hops were lower than high β-acid hops. [Conclusions] Therefore, we can draw a conclusion that the brewing characteristics of high α-acid hops are better than those of high β-acid hops.

Highly Sensitive Detection of Deoxyribonucleic Acid Hybridization Using Au-Gated AlInN/GaN High Electron Mobility Transistor-Based Sensors

Gallium nitride- （GaN） based high electron mobility transistors （HEMTs） provide a good platform for biological detection. In this work, both Au-gated AlInN/GaN HEMT and AlGaN/GaN HEMT biosensors are fabricated for the detection of deoxyribonucleic acid （DNA） hybridization. The Au-gated AIInN/GaN HEMT biosensor exhibits higher sensitivity in comparison with the AlGaN/GaN HEMT biosensor. For the former, the drain-source current （VDS = 0.5 V） shows a clear decrease of 69μA upon the introduction of 1μmolL^-1 （μM） complimentary DNA to the probe DNA at the sensor area, while for the latter it is only 38 μA. This current reduction is a notable indication of the hybridization. The high sensitivity can be attributed to the thinner barrier of the AlInN/GaN heterostructure, which makes the two-dimensional electron gas channel more susceptible to a slight change of the surface charge.

Simultaneous determination of 12,13-dihydroxyeuparin and glycyrrhizic acid in Yanyanfang mixture by high performance liquid chromatography

A reversed phase high performance liquid chromatography （HPLC） method was established for the simultaneous determination of 12, 13-dihydroxyeuparin and glycyrrhizic acid in Yanyanfang mixture. A Grace Apollo Cl8 column （250 mm × 4.6 mm, 5 μm） was used as the stationary phase and the mobile phase was composed of acetonitrile and aqueous phosphoric acid （0.2%, v/v）. Gradient elution was carried out at the flow rate of 1.0 mL/min and the column temperature was 30 ℃. An ultraviolet （UV） detector was used with a selected wavelength of 240 nm. Calibration curves were linear within the concentration range of 4.6-45.75 μg/mL for 12, 13-dihydroxyeuparin （r〉0.9999） and 106.9-1068.9μg/mL for glycyrrhizic acid （r〉0.9999）, respectively. Recoveries were 102.18% for 12, 13-dihydroxyeuparin and 101.17% for glycyrrhizic acid. The method developed could be applied to the simultaneous determination of 12, 13- dihydroxyeuparin and glycyrrhizic acid in Yanyanfang mixture.

OPTICALLY ACTIVE AMINO ACIDS WITH HIGHLY BRANCHED SIDE CHAIN (I) SYNTHESIS OF D- AND L- 2-AMINO-5,5-DIMETHYLHEXANOIC ACID AND 2-AMINO-6,6-DIMETHYLHEPTANOIC ACID

The title compounds were prepared by the enzymatic resolution of the corresponding N-acetylated DL-amino acids methyl esters, which were obtained from t-butyl chloride via an 8-step synthesis.

Pathological Changes in Rabbit Retina and Its Relationship with Glutamic Acid after Injuries from High-Speed Bullets

Purpose:To observe the pathological changes in rabbit retinas and the measure of glutamic acid levels in the vitreous body after suffering from high-speed bullet injuries.Methods:Rabbits eyeball contusion models were established with high-speed bullets,i.e,the rabbits eyes were shot with a fixed air rifle at a speed of 90 m/s.(using plastic bullets,weighing 0.201 g,on average).Retinal tissues treated with HE staining and were prepared for light microscopy examination and glutamate levels were tested at different time points after the injury.Results:Edema,exudation,hemorrhage,and rupture were evident in rabbit retinas following bullet injuries.Meanwhile,glutamate levels gradually increased as time proceeded.Conclusion:Visual impairment is related with retinal damages after high-speed bullet injuries.Increased glutamate concentration serves as a potential factor for aggravating retinal injuries.

High-performance Liquid Chromatographic Determination of Urinary Trans,Trans-Muconic Acid Excreted by Workers Occupationally Exposed to Benzene

Objective To investigate the relationship between trans, trans-muconic acid （ttMA） as benzene metabolite of occupational workers and benzene concentration in air. Methods A rapid and sensitive high-performance liquid chromatography was developed to determine the level of urinary ttMA. ttMA was extrated from urinary samples in liquid-liquid phase a ODS （2） （5u） column （Ф4.6 min× 150 mm） and detected at wavelength 264 nm in a UV detector using vanillic acid as an internal standard. The mobile phase was acetaticacid/tetrahydrofuran/methanol/water （v/v, 1：2：10：87）. The method was validated with 56 urine samples collected from occupationally benzene-exposed individuals. Results A correlation coefficient （r = 0.9963 ） was found for ttMA ranging 0.10-10.00 μg/mL. The limit of detection was 0.10μ g/mL. The recovery and reproducibility were generally over 90%. There was a positive correlation between ttMA and benzene level in air. The equation was Y=0.859＋0.108C （before work, r=0.6200） or Y=1.980＋0.179C （after work, r=0.7930）. Conclusion This method can be used to determine and control the level of urinary ttMA in those who are occupationally exposed to benzene.

EFFECTS OF SIMVASTAIN COMBINED WITH OMEGA-3 FATTY ACIDS ON HIGH SENSITIVE C-REACTIVE PROTEIN, LIPIDEMIA, ANDFIBRINOLYSIS IN PATIENTS WITH MIXED DYSLIPIDEMIA

Objective To evaluate the effects of simvastatin combined with omega-3 fatty acids on high sensitive C-reactive protein(HsCRP), lipidemia, and fibrinolysis in coronary heart disease (CHD) and CHD risk equivalent patients with mixed dyslipi-demia. Methods A randomized, double-blind placebo controlled and parallel group trial was conducted. Patients with CHD and CHD risk equivalents with mixed dyslipidemia were treated with 10 or 20 mg simvastatin for 6-12 weeks. Following with the treatment of patients whose low-density lipoprotein cholesterol (LDL-ch) reaching goal level (< 100 mg/dL) or close to the goal (< 130 mg/dL), while triglyceride (TG) ≥200 mg/dL and < 500 mg/dL, was combined with omega-3 fatty acids (3 g/d) or a placebo for 2 months. The effects of the treatment on HsCRP, total cholesterol (TC), LDL-ch, high-density lipoprotein cholesterol (HDL-ch), TG, lipoprotein (a) [LP (a)], apolipoprotein A1 (apoA1), apolipoprotein B (apoB), plasminogen activator inhibitor-1 (PAI-1), and tissue plasminogen activator (tPA) were investigated. Forty patients finished the study with each group consisting of twenty patients. Results (1) There were significant reductions of HsCRP, TG, TC, and TC/HDL-ch, which decreased by 2.16 ±2.77 mg/L (38.5%), 94.0 ±65.4 mg/dL (31.1%), 13.3 ±22.3 mg/dL (6.3%), 0.78 ±1.60 respectively in the omega-3 fatty acids group (P< 0.01, < 0.001, < 0.05, < 0.05) compared to the baseline. HsCRP and triglyceride reduction were more significant in omega-3 fatty acids group compared to the placebo group (P=0.021 and 0.011 respectively). (2) In the omega-3 fatty acids group, the values and percentage of TG reduction had a significantly positive relation with HsCRP reduction (r=0.51 and 0.45, P=0.021 and 0.047 respectively). Conclusion In CHD and CHD risk equivalent patients with mixed dyslipidemia, dyslipidemia’s therapeutic effect using simvastatin and omega-3 fatty acids may result from not only the combination of lipid adjustment, but also enhancement of their own nonlipid influences.

Determination of Organic Acids in Root Exudates by High Performance Liquid Chromatography:Ⅱ.Influence of Several Testing Conditions

Effects of column temperature and flow rate on separation of organic acids were studied by determining nine low-molecular-weight organic acids on reversed- phase C18 column, using high performance liquid chromatography (HPLC) with a wavelength of UV (ultraviolet) 214 urn and a mobile phase of 18 mmol L-1 KH2PO4 buffer solution (pH 2.1). The thermal stability of organic acids was determined by comparing the recoveries of organic acids in different temperature treatments. The relationships between column temperature, flow rate or solvent pH and retention time were analyzed. At low solvent pH, separation efficiency of organic acids was increased by raising the flow rate of the solvent because of lowering the retention time of organic acids. High column temperature was unfavorable for the separation of organic acids. The separating effect can be enhanced through reducing column temperature in organic acid determination due to increasing retention time. High thermal stability of organic acids with low concentrations was observed at temperature of 40 ℃-45℃. Sensitivity and separation effect of organic acid determination by HPLC were clearly improved by a combination of raising flow rate and lowering column temperature at low solvent pH.

Analysis of Amino Acids in Houttuynia Cordata Thunb. by High Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD)

[Objectives] The biologically active compounds of Houttuynia cordata Thunb. as a medicinal and edible plant are well documented. However, amino acid as an important indicator of the value of H. cordata is little reported. [Methods] Amino acids of the H. cordata were analysed by pre-column derivatization with 2,4-dinitrochlorobenzne(CDNB) coupled to HPLC/DAD. The optimized conditions of the amino acids derivatized by CDNB were followed: 110 ℃ of hydrolysis temperature, 1∶12 of the equivalent proportion between amino acid and CDNB, 80 min of derivatization reaction time and 80 ℃ of derivatization reaction temperature. The method was used to determine the amino acids of H. cordata samples from 11 different geographical sites in Guizhou. [Results] The results suggested that the contents of 17 amino acids were quite variable at different H. cordata samples. [Conclusions] This study will provide a basis for the quality evaluation of H. cordata nutrition.