Comparative study of functional optical zone:small incision lenticule extraction versus femtosecond laser assisted excimer laser keratomileusis

AIM:To investigate the size of functional optical zone(FOZ)after small incision lenticule extraction(SMILE)versus femtosecond laser assisted excimer laser keratomileusis(FS-LASIK)for myopia correction and potential associated factors for FOZ.METHODS:A total of 133 patients who received corneal refractive surgery in our hospital between November 2018 and July 2021 were retrospectively enrolled.There were 63 patients(123 eyes)in SMILE group and 70patients(139 eyes)in FS-LASIK group.The size of FOZ was measured using Pentacam 3-dementional anterior segment analyzer before and 3mo after surgery,so as to analyze postoperative achieved functional optical zone(AFOZ)and its contributing parameters.RESULTS:When planned functional optical zone(PFOZ)was 6.5 mm for both groups,AFOZ was 1.45±0.27 and 1.67±0.25 mm smaller than preoperative FOZ in SMILE group and FS-LASIK group 3mo after surgery.AFOZ in SMILE group was significantly larger than that in FS-LASIK group(P<0.001).Variation of FOZ was negatively correlated with preoperative spherical equivalent(SE)and positively correlated with variation of mean keratometry value(△Km),variation of spherical aberration(△SA),and variation of Q-value(△Q,all P<0.001)in both groups.Multiple variable linear regression equations were△FOZ=1.354-0.1×pre-SE+0.336×△Q+1.462×△SA in SMILE group and△FOZ=1.512+0.137×△Q+0.468×△SA in FS-LASIK group.CONCLUSION:AFOZ is significantly smaller than preoperative FOZ in both SMILE and FS-LASIK groups.With the same PFOZ,larger AFOZ is achieved in SMILE group than in FS-LASIK group.

MICROWAVE-ASSISTED EXTRACTION OF GLYCYRRHIZIC ACID FROM LICORICE ROOT-EFFECT OF THE PROPERTY OF SOLUTION ON EXTRACTION OF GA

The property of extraction solution is an important factor influencing the extraction efficiency. In the present work, the effect of the property of solution on extraction of GA was studied, which including the concentration of ethanol, ammonia and cation (M+), pH of extraction solution, different kinds of organic solvent etc. The results show that 50%-60%(v/v) ethanol can reach high percentage extraction of GA. If 1% (v/v) ammonia solution was added into 60%(v/v) ethanol, the percentage extraction can be increased from 2.0% to 2.31%. Without ammonia, 50mmol/L [M+] (M+ = K+, NH4+) was added into 60%(v/v) ethanol, percentage extraction of GA can reach about 2.26%. If pH of solution (60% ethanol) was adjust to pH=4.0, it can reach high percentage extraction. If pH of solution (60% ethanol + 50mmol [M+], pH=6.1) was adjust tO PH=4.0, especially M+ is K+ or NH4+, it can reach almost same extraction efficiency as that of 1% ammonia solution + 60% ethanol, and the operation environment can be greatly improved.

Microwave-assisted Extraction of Rutin and Quercetin from Flos Sophorae

Three microwave-assisted extraction(MAE) procedures were studied. The first procedure was household microwave oven dynamic extraction(HMODE). The second procedure was special microwave oven bath extraction(SMOBE). The third procedure was microwave resonant cavity dynamic extraction(MRCDE). The results obtained by the three microwave-assisted extraction procedures were compared with those obtained by using traditional Soxhlet extraction. The results indicate that the MAE not only took a shorter time, but also simplified the procedure, and made the extraction a higher yield. At the same time the results obtained by the three MAE procedures were also compared with each other.

Optimization of microwave-assisted extraction of bioactive alkaloids from lotus plumule using response surface methodology

In this work,a fast and efficient microwave-assisted extraction(MAE) method was developed to extract main bioactive alkaloids from lotus plumue.To optimize MAE conditions,three main factors were selected using univariate approach experiments,and then central composite design(CCD).The optimal extraction conditions were as follows:methanol concentration of 65%,microwave power of 200 W,and extraction time of 260 s.A high performance liquid chromatography–diode array detector(HPLC–DAD) method was established to quantitatively analyze these phytochemicals in different lotus plumule samples and in different part of lotus.Chromatographic separation was carried out on an Agilent Zorbax Extend-C_(18) column(4.6 mm×150 mm,3.5 μm).Gradient elution was applied with the mobile phase constituted with 0.1% triethylamine in water(A)and acetonitrile(B):40%-70% B at 0-8 min,70%-100% B at 8–9 min,100% B for 2 min,and then equilibrated with 40% B for 2 min.

Microwave-assisted solvent extraction of castor oil from castor seeds

This study was aimed at evaluating the physicochemical properties and oxidation stability of castor oil using microwave-assisted solvent extraction(MAE). MAE was performed using 5% ethanol in hexane as solvent at different extraction times, power intensities and solvent-to-feed(S/F, ml of solvent to gram of feed) ratios.The process parameters were optimized by statistical approach using historical data design of response surface method(RSM). The oils were characterized for yield, physicochemical properties, dielectric properties and oxidation stability, and comparison was also made with oil extracted using Soxhlet method. Results show that the maximum oil yield of 37% was obtained at 20 min with microwave power intensity of 330 W and S/F ratio of 20. The main fatty acid composition of castor oil is ricinoleic acid. The density, refractive index, dielectric properties and oxidation stability of oils are not affected by the extraction methods and extraction parameters of MAE. However, the MAE-extracted oil is more viscous compared to that by Soxhlet method. With extra caution on oil oxidation, MAE could be a promising solvent extraction method with an 86% less in processing time and a higher yield.

Response surface optimization of microwave-assisted extraction for HPLC-fluorescence determination of puerarin and daidzein in Radix Puerariae thomsonii

Microwave-assisted extraction was optimized with response surface methodology for HPLC-fluorescence determination of puerarin and daidzein in Radix Puerariae thomsonii.The optimized extraction procedure was achieved by soaking the sample with 70% methanol（1∶15,v/v）for 30 min,and then microwave irradiation for 11 min at a power of 600 W.Coupling the extraction process with HPLC-fluorescence presented good recovery,satisfactory precision,and good linear relation.Compared with a method from the Chinese Pharmacopoeia,the proposed method enables higher extraction efficiency and more accurate analytical results.It can be of potential value in quality assessment of Radix Puerariae thomsonii medicinal materials.

Application and research advancement on the microwave-assisted extraction

This paper summarized application and research advancement of the microwave-assisted extraction in the agriculture, food industry, environmental analytical chemistry, traditional Chinese medicine industry, and so on. The microwave-assisted extraction was manifested to be a simple device, wide area of application, high extraction efficiency, good reproducibility and low consumption of agent and time as well as low environmental pollution. At present, industrialization question of the microwave-assisted extraction technology has been attached importance, which will impel the microwave-assisted extraction technology to more development in the future

Comparison of Response Surface Methodology and Artificial Neural Network in Predicting the Microwave-Assisted Extraction Procedure to Determine Zinc in Fish Muscles

In this paper, the estimation capacities of the response surface methodology (RSM) and artificial neural network (ANN), in a microwave-assisted extraction method to determine the amount of zinc in fish samples were investigated. The experiments were carried out based on a 3-level, 4-variable Box–Behnken design. The amount of zinc was considered as a function of four independent variables, namely irradiation power, irradiation time, nitric acid concentration, and temperature. The RSM results showed the quadratic polynomial model can be used to describe the relationship between the various factors and the response. Using the ANN analysis, the optimal configuration of the ANN model was found to be 4-10-1. After predicting the model using RSM and ANN, two methodologies were then compared for their predictive capabilities. The results showed that the ANN model is much more accurate in prediction as compared to the RSM.

Rapid Lab-Scale Microwave-Assisted Extraction and Analysis of Anthropogenic Organic Chemicals in River Sediments

An Ethos EZ Microwave Lab Station is employed in the development of a robust and efficient microwave extraction method for organic contaminants of anthropogenic origin in river sediments. The extraction method is designed for a small, representative set of target compounds encompassing a range of physicochemical properties. Listed in order of gas chromatography elution they are para-cresol, indole, 4-tert-octylphenol, phenanthrene, triclosan, bisphenol-A, carbamazepine, and benzo [a] pyrene. The sediments samples are extracted wet, which reduces preparation time, and allows the ambient moisture of the sediments to aid in microwave energy absorption and the extraction process. The microwave can hold up to 12 samples that can be simultaneously extracted allowing for rapid sample preparation. Utilizing the pressurized vessels, microwave energy, and a unique mixture of three organic solvents allows for multiple samples to be extracted rapidly with minimal solvent consumption. The final extracts are quantified by gas chromatography/mass spectrometry. Recoveries of the 8 target compounds in sediment range from 49% to 113%, and method detection limits range between 14 and 114 μg kg–1, which are comparable with other more time consuming methods.

Study on chromatographic fingerprint of sarcandra glabra (Thunb.) by microwave-assisted extraction coupled to HPLC/DAD

Microwave-assisted extraction(MAE)was used for extraction of effective components of sarcandra glabra(Thunb.),and then chromatographic fingerprint of sarcandra glabra(Thunb.)was studied by high performance liquid chromatography/diode array detector(HPLC/DAD).The conditions of MAE were optimized by an orthogonal experiment,and then the authentication and validation of the chromatographic fingerprint were conducted.Nine peaks were identified as common peaks in the fingerprint chromatograms,and isofraxidin was considered as a reference compound and quantified.Relative standard deviations of retention time and peak area of each component were less than 3% and 8%,respectively.Similarity and difference analysis were conducted by use of PCA and relation coefficient.Twenty batches of sarcandra glabra(Thunb.)samples from two different producing areas could be classified into two different groups in the PCA model.The results showed that MAE-HPLC/DAD method was simple,efficient and stable for the study of complex chromatographic fingerprint of sarcandra glabra(Thunb.),which could provide more reliable and precise information for quality evaluation.

Research Progress of Deep Eutectic Solvents in Extraction of Plant Flavonoids

As a new type of green solvents,deep eutectic solvents(DESs)have the advantages of strong extraction ability,designability,simple preparation,low price,recoverability and biodegradation,and show great application potential in the field of plant flavonoid extraction.In this paper,the definition,classification and preparation methods of DESs were introduced.The effects of DES composition,molar ratio of DES components,water content of DES systems,liquid-material ratio,extraction temperature,extraction time and extraction auxiliary techniques on the extraction yield of plant flavonoids were expounded.The recycling methods of DESs were summarized.Existing problems of DESs in the field of plant flavonoids extraction were pointed out,and further research direction and trend were analyzed and prospected.

Effect of Process Parameters of Microwave Assisted Extraction (MAE) on Polysaccharides Yield from Pumpkin

Process parameters of microwave assisted extraction （MAE） of the polysaccharides from pumpkin viz. extraction temperature, time and liquid-solid ratio were studied by using single factor and response surface methodology method. The results showed that the liquid-solid ratio was the most important factor in polysaccharides yield, followed the extraction temperature was the least important factor. The optimum microwave assisted extraction co by ndi extraction time, and tions for the highest polysaccharides yield from pumpkin （16.76%-4-0.38%） were obtained by using the response surface methodology with extraction time of 29 min, an extraction temperature of 79 ℃ and a liquid-solid ratio of 22 mL·g^-1. Validation experiment result well agreed with predicted value.

Salting-Out Assisted Liquid-Liquid Extraction Combined with HPLC for Quantitative Extraction of Trace Multiclass Pesticide Residues from Environmental Waters

In this study, salting-out assisted liquid-liquid extraction combined with high performance liquid chromatography diode array detector (SALLE-HPLC-DAD) method was developed and validated for simultaneous analysis of carbaryl, atrazine, propazine, chlorothalonil, dimethametryn and terbutryn in environmental water samples. Parameters affecting the extraction efficiency such as type and volume of extraction solvent, sample volume, salt type and amount, centrifugation speed and time, and sample pH were optimized. Under the optimum extraction conditions the method was linear over the range of 10 - 100 μg/L (carbaryl), 8 - 100 μg/L (atarzine), 7 - 100 μg/L (propazine) and 9 - 100 μg/L (chlorothalonil, terbutryn and dimethametryn) with correlation coefficients (R2) between 0.99 and 0.999. Limits of detection and quantification ranged from 2.0 to 2.8 μg/L and 6.7 to 9.5 μg/L, respectively. The extraction recoveries obtained for ground, lake and river waters were in a range of 75.5% to 106.6%, with the intra-day and inter-day relative standard deviation lower than 3.4% for all the target analytes. All of the target analytes were not detected in these samples. Therefore, the proposed SALLE-HPLC-DAD method is simple, rapid, cheap and environmentally friendly for the determination of the aforementioned herbicides, insecticide and fungicide residues in environmental water samples.

Optimization of enzyme assisted extraction of polysaccharides from Ganoderma lucidum

In the present work,an enzyme assisted extraction method is used to isolate crude polysaccharides from Ganoderma lucidum. The isolating effect was optimized with orthographic graph statistic method with three levels and four independent variables. Complex enzyme,extraction temperature,extraction time and extraction pH were combined to obtain the best possible combination to get maximum amount of extract and crude polysaccharides yield. The optimum extraction conditions were:complex enzyme amount of 3 %(w/v),extraction temperature at 45 ℃,extraction time of 3 h and extraction pH at 7. Under these conditions,the experimental amount of extract is 8.9 % and the yield of crude polysaccharides is 1.1 %,which are in close agreement with the value predicted by the model.

Antioxidant and hepatoprotective effects of Ajuga nipponensis extract by ultrasonic-assisted extraction

Objective: To investigate suitable condition for extraction of the active components from Ajuga nipponensis(A. nipponensis). Methods: Orthogonal experimental design was used to determine the optimal extraction parameters for ecdysterones and flavonoids. Finally, the hepatoprotective abilities of A. nipponensis extracts were evaluated by CCl_4-induced animal models. Results:Maximum yields of flavonoids(7.87±0.10) mg/g and ecdysterones(0.73±0.02) mg/g could be obtained when the extraction time was 50 min, the extraction temperature was 60 ℃, and the ratio of sample to 70%(v/v) ethanol was 1:20(w/w). The antioxidant property of A. nipponensis was correlated to the concentration of its extracts. At 5 mg/m L, A. nipponensisextract scavenged 84.8% of DPPH radical and had absorbance values of 2.43±0.04 reducing power. Upon CCl_4-induced liver injury, glutamic oxaloacetic transaminase and glutamic pyruvic transaminase decreased significantly after the mice were treated with A. nipponensis. Histological researches also explained that A. nipponensis reduced the extent of liver lesions induced by CCl_4. Conclusions: A. nipponensis exhibited potent antioxidant activity in chemical experimental models and hepatoprotective effect against CCl_4-induced liver damage.

Optimization of Ultrasonic-Assisted Extraction Process of Polysaccharides from American Ginseng and Evaluation of Its Immunostimulating Activity

Ultrasonic-assisted extraction （UAE） of American ginseng polysaccharides （AGP） was investigated using response surface methodology. Three-factor-three-level Box-Behnken design was employed to optimize the ultrasonic power, extraction time and ratio of water to raw material to obtain a high AGP yield. The analysis of variance and response surface plots indicated that ultrasonic power was the most important factor affecting the extraction yield. The optimal conditions were ultrasonic power 400 W, extraction time 71 min, and ratio of water to raw material 33 mL g-1. Under these conditions, the yield of AGP was 8.09%, which was agreed closely to the predicted value. Gas chromatography （GC） analysis showed that AGP was composed of arabinose, rhamnose, galactose, glucose, and galacturonic acid. Fourier transform infrared spectra revealed the general characteristic absorption peaks of AGP. In addition, AGP exhibited good immunostimulating activities by up-regulating the production of nitric oxide and cytokines. Compared with hot water extraction, UAE required shorter extraction time and gave a higher extraction yield, without changing the structure and immunostimulating activity of AGP. The results indicated that UAE could be an effective and advisable technique for the large scale production of plant polysaccharides.

Optimization of ultrasound-assisted extraction of camptothecin from Camptotheca acuminata seeds

Naturally occurring camptothecin（CPT） is an important source of chemotherapeutic agents.The extraction from Camptotheca acuminata is still the main approach to obtain CPT compared with total synthesis.In the present study,ultrasound-assisted extractions（UAE） of CPT from C.acuminata seeds with alkaline solutions were investigated and CPT yield were determined by High Performance Liquid Chromatography.The conditions of alkaline species and concentrations,extraction time,extraction temperature and ultrasonic power were optimized.Results show that both Na3PO4 and Na2CO3 solutions gain good extraction yields,whereas Na3PO4 solution has stronger basicity and need higher concentration than Na2CO3 solution does,thus aqueous Na2CO3 is more beneficial for the extraction.The optimal condition was ultrasonically extracted with 0.5% aqueous Na2CO3 at 50°C and ultrasonic power of 400 W for 60 min.Comparing with UAE with ethanol,the extraction with 0.5% Na2CO3 solution achieves higher yield.Moreover,aqueous Na2CO3 as a solvent has various advantages including non-toxicity,inflammable,non-corrosive and low cost,which ensure this UAE method is a superior method with high utilizing prospect.

Dry eye and corneal sensitivity after small incision lenticule extraction and femtosecond laser-assisted in situ keratomileusis:a Meta-analysis

AIM：To assess the corneal sensitivity and the incidences of dry eye after small incision lenticule extraction（SMILE） and femtosecond laser-assisted in situ keratomileusis（FSLASIK）.METHODS：The Meta-analysis was performed using Rev Man 5.3.We searched on Pub Med from inception to March 2016.Summary weighted mean difference（WMD） and 95% confidence intervals（CIs） were used to analyze the datum.Random-effects or fixed-effects models were chosen up to between-study heterogeneity.The main outcomes were composed of the Ocular Surface Disease Index（OSDI） scores,tear film break-up time（TBUT）,Schirmer Test and corneal sensitivity.RESULTS：Eight eligible studies including 772 eyes（386 in SMILE group and 386 in FS-LASIK group） were identified.The parameters have no significiant difference heterogeneity between SMILE and FS-LASIK group preoperatively.There were significant differences between the two groups in OSDI scores at one and three months postoperatively,in TBUT at one and three months postoperatively,in corneal sensitivity at one week,about one month and three months postoperatively.However,there was no significant difference observed in Schirmer Test at the follow-up periods.CONCLUSION：Compare to FS-LASIK,dry eye and the corneal sensitivity recover better in the SMILE group,in first three months after the surgery.