Determination of Eleutheroside B and E in Acanthopanax Preparations by High-P erformance Liquid Chromatography with Solid-Phase Extraction

Aim An HPLC method for analyzing eleutheroside B (ELU B) and eleutheroside E(ELU E) , two of the main active substances of Acanthopanax preparations were studied. Methods Thesamples were analyzed on a kromasil ODS column with water-acetonitrile as a gradient mobile phase.The flow rate was 0.8 mL·min^(-1) and detecting wavelengths were 206 nm for ELU B, 220 nm for ELUE, solid phase extraction (SPE) and internal standard-salicin were selected. Results The recoveriesof Acanthopanax tablets and injection were 90.4% - 96.8% and 96.4% - 99.8% for ELU B, 87.7% -93.3%and 95.7% - 98.5% for ELU E, respectively. The linear ranges were 4.45 - 22.25 μg· mL^(-1) (r =0.999 8) and 5.11 - 25.55 μg·mL^(-1) ( r = 0.999 7) respectively. Conclusion This method can savethe time for cleaning the chromatographic system and improve sensitivity for Acanthopanaxpreparations , thus providing a way to evaluate the quality of Acanthopanax preparations.

Preparation and adsorption performance of multi-morphology H_(1.6)Mn_(1.6)O_(4) for lithium extraction

In this paper,a lithium-ion sieve(LIS)with different morphologies,such as rod-like(LIS-R),spherical(LIS-S),flower-like(LIS-F),and three-dimensional macroporous-mesoporous(LIS-3D),was prepared by hydrothermal synthesis,solid reaction,and hard-template synthesis.The results showed that the LIS with different morphologies presented great differences in specific surface area,pore volume,adsorption selectivity,and structure stability.LIS-3D with highest specific surface area and pore volume displayed the maximum adsorption capacity and adsorption rate,but the stability of LIS-3D was poor because of the manganese dissolution.By comparison,LIS-S has the best structural stability while maintaining a satisfactory adsorption capacity(35.02 mg·g^(-1))and adsorption rate.The LIS-S remained about 90%of the original adsorption capacity after five cycles of adsorption-desorption process.In addition,in the simulated brine system(the magnesium to lithium ratio of 400),the LIS-S exhibited the highest selectivity(α_(Mg)^(Li))of 425.14.In sum,the LIS-S with good morphology is a potential adsorbent for lithium extraction from brine.

Preparation of PDMS-coated microspheres by sol-gel method for sorptive extraction of PAHs

In this paper, a novel SPME mode, PDMS-coated solid glass microspheres （SGMs）, were prepared by sol-gel method. Using homemade thermal desorption unit coupled with CGC-FID, six PAHs as model analytes, the performance of the new mode was characterized. The new extractive phase exhibited high thermal stability and satisfactory extraction capability. The detection limits were 0.01-0.045 ng/mL, and the linearity was from 0.5 ng/mL to 96 ng/mL. The R.S.D.s of repeatability for retention time and peak area were all within 0.074% and 6.7%, respectively. The recoveries of the PAHs were 78-127% from the samples taken from river water.

Preparation of protein samples for gel electrophoresis by sequential extraction

Since preparation and solubilization of protein samples are crucial factors in proteome research,the authors established a sequential extraction technique to prepare protein samples from the body wall of the 5th instar larvae of silkworm.Bombyx mori.Two kinds of protein samples were obtained from the body wall using the method.Between the two types of samples only about 15% proteins were identical;the majority were different,indicating that more species of proteins could be obtained with the sequential extraction method;which will be useful for preparation of protein samples for proteome study.

Preparation of Highly Concentrated Silver Nanoparticles in Reverse Micelles of Sucrose Fatty Acid Esters through Solid-Liquid Extraction Method

Silver nanoparticles were synthesized in reverse micelles consisting of sucrose fatty acid esters by dissolving reactant powder in the water pool of reverse micelles through the solid-liquid extraction. Silver nanoparticles having various sizes and shapes were obtained at high concentration. The size of silver nanoparticles was controlled by reaction temperature. Moreover, the size of silver nanoparticles was dependent upon the average esterification degree of sucrose fatty acid esters forming reverse micelles. The wavelength in the peaks, which corresponded upon the localized surface plasmon resonance of resultant silver nanoparticles, was correlated with their sizes.

Relationships between Different Preparations of Cotton Hollow Yarn and Water Soluble PVA Extraction

In this paper cotton hollow yarns were obtained from the core spun yams which were produced on a little modified conventional experiment ring frame with water soluble staple PVA yam as the core. For comparison, yams with same linear densities, same twists of the sheath, different linear densities, different twist directions of the core were prepared. The results show that the tensile strengths of the hollow yarns decrease first, then increase and decrease again, at last the tensile strength trends to reach a steady state with the soluble PVA core extraction proceeding. And when the sheath linear densities of the core spun yams are constant, their twist and twist direction are same as that of the core it will be easier to remove the core of the yam with a higher core size. When the linear densities of the sheath and the core are all constant, the twists of them are same, it will be easier to remove the core of the yam with a different twist direction of core to the sheath.

Optimization of the methods for extraction of chitin in crab shell and preparation of chitosan

A combination of both acid and alkali treatments was used to extract chitin from crab shell in this study. Then, a three factors (NaOH solution concentration, reaction time, reaction temperature) and three levels (35, 45, 55; 2, 6, 10; 70, 105, 140) L 9(3 4) orthogonal experiment design is further adopted to conduct a de acetyl treatment to prepare chitosan by considering the viscosity and de acetyl degree of the chitosan as the main performance indexes. Determination of de acetyl degree of chitin complys with the procedures given by the reference and the viscosity meter was used for determination of viscosity of chitosan. The results show that the extraction of chitin shall use pulverized crab shell as the raw material and such raw material shall be immersed in 10% HCl solution for 6 hours and washed with water for one time in every 2 hours, then heated in boiled water for 2 hours by the use of 10% thin NaOH solution. Afterwards, the said material shall be washed with water to become a neutral solution and dried over a stove. When chitin is mixed with 55% NaOH solution in a proportion of 1∶10 (W/V, g/mL) and the reaction takes place at a temperature of 105℃ for 6 hours, chitosan having a de acetyl percentage of 94% and viscosity of >200 cps can be available.

Chemical Extraction Preparation of Delithiated Cathode Materials of Li-ion Battery

A method of conventional chemical reaction to prepare delithiated cathode materials of Li-ion battery was introduced. The cathode material of Li-ion battery was mixed with oxidizing agent Na2S2O8 in water solution, and the solution was stirred continuously to make the chemical reaction proceed sufficiently, then the reaction product was filtered and finally the insoluble delithiated cathode material was obtained. A series of tests were conducted to verify the composition, crystal structure and electrochemical property of the delithiated cathode materials were all desirable. This method overcomes the shortcomings of battery charging preparation and chemical extraction preparation employing other oxidizing agents.

Improved preparation and identification of aristolochic acid-DNA adducts by solid-phase extraction with liquid chromatography-tandem mass spectrometry

Aristolochic acid （AA） is a known nephrotoxin and potential carcinogen, which can form covalent DNA adducts after metabolic activation in vivo and in vitro. A simple method for preparation and characterization of aristolochic acid-DNA adducts was developed. Four AA-adducts were synthesized by a direct reaction of AAI/AAII with 2′-deoxynucleosides. The reaction mixture was first cleaned-up and pre-concentrated using solid phase extraction （SPE）, and further purified by a reversed-phase high performance liquid chromatography （HPLC）. By the application of developed SPE procedure, matrices and byproducts in reaction mixture could be greatly reduced and adducts of high purity （more than 94% as indicated by HPLC） were obtained. The purified AA-DNA adducts were identified and characterized with liquid-electrospray ionization-quadrupole-time of flight-mass spectrometry （LC-ESI-Q-TOF-MS/MS） and LC-Diode array detector-fluorescence （LC-DAD-FL） analysis. This work provides a robust tool for possible large-scale preparation of AA-DNA adduct standards, which can promote the further studies on carcinogenic and mutagenic mechanism of aristolochic acids.

Largescale Preparation of Organic-Dispersible Lanthanide Fluorides Nanocrystals via Colloid-Extraction Route

Organic-dispersible lanthanide fluorides nanocrystals were synthesized at a large scale using colloid-extraction method, in the presence of dialkyl-dithiophosphinic acid (DDPA) as the extraction agent. The products were characterized by means of X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier transformation infrared (FTIR) spectroscopy. It was found that the synthesized lanthanide fluorides nanoparticles had high purity and crystallinity, and could be well dispersed in organic solvents such as chloroform, toluene etc., which could be closely related to the surface-capping of the nanocrystals by the DDPA molecules. Moreover, the nanocrystals before and after extraction by DDPA showed few differences in the microscopic morphologies. It was implied that DDPA as the extraction agent had good protection to the nanocrystals as well, which could be essential to the commercial application of the titled rare earth nanocrystals as novel multifunctional additives in the fields of lubrication.

Preparation and Characterization of β-TCP/CS Scaffolds by Freeze-extraction and Freeze-gelation

The freeze-extraction and freeze-gelation methods were used to prepare highly porous β-TCP/CS scaffolds with different β-TCP/CS ratio.In these methods,the suspending mixture of β-TCP and chitosan was frozen,the frozen mixture was immersed in a non-solvent（0.05mol/L NaOH/ehanol aqueous） bath to allow the exchange between solvent（acetic-acid aqueous） and non-solvent at a temperature lower than the freezing point of the acetic-acid.Then,the β-TCP/CS scaffolds were formed and dried at room temperature.Scanning electron microscopy （SEM）,X-ray diffraction （XRD）,gas chromatography （GC） and omnipotence material testing machine were employed to characterize the β-TCP/CS scaffolds.The results of GC show that the freeze extraction of the β-TCP/chitosan scaffolds was completed when the extraction time is above 24 h.The SEM results show that the β-TCP/CS scaffolds are composed of interconnected pore network.The porosity of the β-TCP/CS scaffolds decrease with the increase of the content of the β-TCP.The β-TCP/CS scaffolds have a highest compressive strength when the chitosan/β-TCP ratio is 30：70.The present work displays that the β-TCP/CS composite scaffolds with appropriate mechanical properties and high porosity can be successfully prepared by the freeze-extraction and freeze-gelation methods.

Preparation of N, N'-diacylpiperazine and its extraction property for U(Ⅵ)

A novel extractant, N, N’-diacylpiperazine (DAPEZ), was synthesized and characterized for the first time. Its extraction property for U(VI) from aqueous nitric acid media has been studied. The effects of concentration of nitric acid and extractant on the distribution ratio were examined and the extraction mechanism were discussed.

Bowel preparation before colonoscopy: Consequences, mechanisms, and treatment of intestinal dysbiosis

The term“gut microbiota”primarily refers to the ecological community of various microorganisms in the gut,which constitutes the largest microbial community in the human body.Although adequate bowel preparation can improve the results of colonoscopy,it may interfere with the gut microbiota.Bowel preparation for colonoscopy can lead to transient changes in the gut microbiota,potentially affecting an individual’s health,especially in vulnerable populations,such as patients with inflammatory bowel disease.However,measures such as oral pro-biotics may ameliorate these adverse effects.We focused on the bowel prepa-ration-induced changes in the gut microbiota and host health status,hypothesized the factors influencing these changes,and attempted to identify measures that may reduce dysbiosis,thereby providing more information for individualized bowel preparation for colonoscopy in the future.

Effects of ultrasonic-assisted extraction on bioactive compounds,volatile flavors and antioxidant activities of vine tea water extracts

Background:Ampelopsis grossedentata,vine tea,which is the tea alternative beverages in China.In vine tea processing,a large amount of broken tea is produced,which has low commercial value.Methods:This study investigates the influence of different extraction methods(room temperature water extraction,boiling water extraction,ultrasonic-assisted room temperature water extraction,and ultrasonic-assisted boiling water extraction,referred to as room temperature water extraction(RE),boiling water extraction(BE),ultrasonic assistance at room temperature water extraction(URE),and ultrasonic assistance in boiling water extraction(UBE))on the yield,dihydromyricetin(DMY)content,free amino acid composition,volatile aroma components,and antioxidant properties of vine tea extracts.Results:A notable influence of extraction temperature on the yield of vine tea extracts(P<0.05),with BE yielding the highest at 43.13±0.26%,higher than that of RE(34.29±0.81%).Ultrasound-assisted extraction significantly increased the DMY content of the extracts(P<0.05),whereas DMY content in the RE extracts was 59.94±1.70%,that of URE reached 66.14±2.78%.Analysis revealed 17 amino acids,with L-serine and aspartic acid being the most abundant in the extracts,nevertheless ultrasound-assisted extraction reduced total free amino acid content.Gas chromatography-mass spectrometry analysis demonstrated an increase in the diversity and quantity of compounds in the vine tea water extracts obtained through ultrasonic-assisted extraction.Specifically,69 and 68 volatile compounds were found in URE and UBE extracts,which were higher than the number found in RE and BE extracts.In vitro,antioxidant activity assessments revealed varying antioxidant capacities among different extraction methods,with RE exhibiting the highest DPPH scavenging rate,URE leading in ABTS•+free radical scavenging,and BE demonstrating superior ferric ion reducing antioxidant activity.Conclusion:The findings suggest that extraction methods significantly influence the chemical composition and antioxidant properties of vine tea extracts.Ultrasonic-assisted extraction proved instrumental in elevating the DMY content in vine tea extracts,thereby enriching its flavor profile while maintaining its antioxidant properties.

Effects of conductive agent type on lithium extraction from salt lake brine with LiFePO_(4) electrodes

Electrochemical lithium extraction from salt lakes is an effective strategy for obtaining lithium at a low cost.Nevertheless,the elevated Mg:Li ratio and the presence of numerous coexisting ions in salt lake brines give rise to challenges,such as prolonged lithium extraction periods,diminished lithium extraction efficiency,and considerable environmental pollution.In this work,Li FePO4(LFP)served as the electrode material for electrochemical lithium extraction.The conductive network in the LFP electrode was optimized by adjusting the type of conductive agent.This approach resulted in high lithium extraction efficiency and extended cycle life.When the single conductive agent of acetylene black(AB)or multiwalled carbon nanotubes(MWCNTs)was replaced with the mixed conductive agent of AB/MWCNTs,the average diffusion coefficient of Li+in the electrode increased from 2.35×10^(-9)or 1.77×10^(-9)to 4.21×10^(-9)cm^(2)·s^(-1).At the current density of 20 mA·g^(-1),the average lithium extraction capacity per gram of LFP electrode increased from 30.36 mg with the single conductive agent(AB)to 35.62 mg with the mixed conductive agent(AB/MWCNTs).When the mixed conductive agent was used,the capacity retention of the electrode after 30 cycles reached 82.9%,which was considerably higher than the capacity retention of 65.8%obtained when the single AB was utilized.Meanwhile,the electrode with mixed conductive agent of AB/MWCNTs provided good cycling performance.When the conductive agent content decreased or the loading capacity increased,the electrode containing the mixed conductive agent continued to show excellent electrochemical performance.Furthermore,a self-designed,highly efficient,continuous lithium extraction device was constructed.The electrode utilizing the AB/MWCNT mixed conductive agent maintained excellent adsorption capacity and cycling performance in this device.This work provides a new perspective for the electrochemical extraction of lithium using LFP electrodes.

A comprehensive review of existing corpora and methods for creating annotated corpora for event extraction tasks

Purpose:The purpose of this study is to serve as a comprehensive review of the existing annotated corpora.This review study aims to provide information on the existing annotated corpora for event extraction,which are limited but essential for training and improving the existing event extraction algorithms.In addition to the primary goal of this study,it provides guidelines for preparing an annotated corpus and suggests suitable tools for the annotation task.Design/methodology/approach:This study employs an analytical approach to examine available corpus that is suitable for event extraction tasks.It offers an in-depth analysis of existing event extraction corpora and provides systematic guidelines for researchers to develop accurate,high-quality corpora.This ensures the reliability of the created corpus and its suitability for training machine learning algorithms.Findings:Our exploration reveals a scarcity of annotated corpora for event extraction tasks.In particular,the English corpora are mainly focused on the biomedical and general domains.Despite the issue of annotated corpora scarcity,there are several high-quality corpora available and widely used as benchmark datasets.However,access to some of these corpora might be limited owing to closed-access policies or discontinued maintenance after being initially released,rendering them inaccessible owing to broken links.Therefore,this study documents the available corpora for event extraction tasks.Research limitations:Our study focuses only on well-known corpora available in English and Chinese.Nevertheless,this study places a strong emphasis on the English corpora due to its status as a global lingua franca,making it widely understood compared to other languages.Practical implications:We genuinely believe that this study provides valuable knowledge that can serve as a guiding framework for preparing and accurately annotating events from text corpora.It provides comprehensive guidelines for researchers to improve the quality of corpus annotations,especially for event extraction tasks across various domains.Originality/value:This study comprehensively compiled information on the existing annotated corpora for event extraction tasks and provided preparation guidelines.

Research Progress of Bowel Preparation for Colonoscopy

Colorectal cancer ranks third in the global cancer data in 2020. Colorectal scope is the most effective method to diagnose colorectal diseases such as benign and malignant colorectal tumors. The poor quality of intestinal preparation causes an increased rate of missed diagnosis of colorectal tumors, reduces the rate of cecal intubation for colorectal examination, increases the discomfort, and reduces the compliance of re-examination. Therefore, we should try our best to improve the quality of intestinal preparation. This study reviewed the latest advances related to the preoperative preparation for colonoscopy. Recent research shows that smartphone apps can provide more detailed education and guidance on bowel preparation;Pre-packaged foods are more suitable as a way to eat before colonoscopy. The use of smaller doses, better taste of cathartic agents, and some auxiliary measures, combined with the patient’s situation to provide personalized intestinal preparation measures to improve the quality of intestinal preparation. Starting from the quality of colonoscopy bowel preparation, continuous improvement of patients’ tolerance to bowel preparation, continuous improvement of bowel preparation plan based on individual factors’ needs, and better communication with examined subjects by using existing scientific information technology, may be the hot spot of colonoscopy bowel preparation research in the next few years.

A Joint Entity Relation Extraction Model Based on Relation Semantic Template Automatically Constructed

The joint entity relation extraction model which integrates the semantic information of relation is favored by relevant researchers because of its effectiveness in solving the overlapping of entities,and the method of defining the semantic template of relation manually is particularly prominent in the extraction effect because it can obtain the deep semantic information of relation.However,this method has some problems,such as relying on expert experience and poor portability.Inspired by the rule-based entity relation extraction method,this paper proposes a joint entity relation extraction model based on a relation semantic template automatically constructed,which is abbreviated as RSTAC.This model refines the extraction rules of relation semantic templates from relation corpus through dependency parsing and realizes the automatic construction of relation semantic templates.Based on the relation semantic template,the process of relation classification and triplet extraction is constrained,and finally,the entity relation triplet is obtained.The experimental results on the three major Chinese datasets of DuIE,SanWen,and FinRE showthat the RSTAC model successfully obtains rich deep semantics of relation,improves the extraction effect of entity relation triples,and the F1 scores are increased by an average of 0.96% compared with classical joint extraction models such as CasRel,TPLinker,and RFBFN.

Extraction of the Residual Polycyclic Aromatic Hydrocarbons in the Long-term Contaminated Soil in the Field

[Objective] The aim of this study was to find a better method to exactly quantify the residual polycyclic aromatic hydrocarbons（PAHs）in the long-term contaminated soil in the field so as to provide basis for the remediation for PAHs contaminated soil.[Method]The comparisons of soxhlet extraction,ultrasonic extraction and shaking extraction were studied in the agricultural soil irrigated with oil sewage over a long period of time.[Result]The total PAHs extracted by soxhlet extraction were the highest（6 873.7 μg/kg）,followed by shaking extraction（6 698.8 μg/kg）and ultrasonic extraction（5 737.6 μg/kg）.Among these methods,the highest extracted 4 and 6 rings PAHs were in the soxhlet extraction,the highest extracted 2 and 5 rings PAHs were in the shaking extraction,and the highest extracted 3 rings PAHs were in the ultrasonic extraction.[Conclusion]This study had provided basis for the selection of the assessment method of residual PAHs in the field soil.