Extraction of geraniol from palmarosa oil using hydrotropic solvents / Extracción de geraniol del aceite de palmarosa utilizando solventes hidrotrópicos

The extraction of geraniol from palmarosa oil using hydrotropic solvents was investigated. Palmarosa oil possesses an appealing rose aroma and properties like anti - inflammatory, antifungal, and antioxidant due to the presence of geraniol. The extraction of geraniol from palmarosa oil by using distillation methods like steam dis tillation and fractional distillation was a laborious process. So hydrotropes were tried for extraction. The geraniol yield and purity depend on parameters like concentration of hydrotrope, solvent volume ratio, and time period. Using the Box Benkhem Desig n (BBD), the extraction process was optimized. One of the major advantages of using hydrotropic solvents is that they were classified as green solvents, and recovery of solvents is also possible. To reduce the extraction time probe sonication is carried ou t. Different hydrotropic solvents with probe sonication are done on palmarosa oil by altering various process parameters to study the separation, yield, and purity.

Se investigó la extracción de geraniol del aceite de palmarosa utilizando solventes hidrotrópicos. El aceite de palmarosa posee un atractivo aroma a rosa y propiedades antiinflamatorias, antifúngicas y antioxidantes debido a la pr esencia de geraniol. La extracción de geraniol del aceite de palmarosa mediante métodos de destilación como la destilación por vapor y la destilación fraccionada ha sido un proceso laborioso. Por lo tanto, se probaron los hidrotropos para la extracción. El rendimiento y la pureza del geraniol dependen de parámetros como la concentración del hidrotropo, la relación de volumen del solvente y el período de tiempo. Se optimizó el proceso de extracción usando el diseño Box Benkhem (BBD). Una de las principales v entajas de usar solventes hidrotrópicos es que se clasifican como solventes verdes y también es posible recuperar los solventes. Para reducir el tiempo de extracción, se lleva a cabo una sonda de ultrasonido. Se realizan diferentes solventes hidrotropos co n sonda de ultrasonido en el aceite de palmarosa alterando varios parámetros del proceso para estudiar la separación, el rendimiento y la pureza.

Effects of parameters of BiPAP ventilator on compliances of chest and lung,and arterial blood gas indexes of AECOPD patients / 中国医学装备

Objective:To explore the effects of ventilator parameters on the compliances of chest and lung,and arterial blood gas indicators of patients with acute exacerbation of chronic obstructive pulmonary disease(AECOPD)when biphasic positive airway pressure(BiPAP)ventilation treated AECOPD patients at acute exacerbation period.Method:A total of 78 AECOPD patients who underwent non-invasive ventilation treatment by using BiPAP ventilators in Xinjiang Cardiovascular and Cerebrovascular Hospital from April 2020 to April 2021 were selected.The common range of inspiratory positive airway pressure(IPAP)was 10-25 cmH2O.Based on the specific situation and adjustment of clinical needs of patients,this study set"<15 cmH2O"as the low IPAP group(n=34),and set"≥15 cmH2O"as the high IPAP group(n=44)to analyze the correlation between IPAP of BiPAP ventilator parameters and the therapeutic effects,chest lung compliances and arterial blood gas indicators of patients.Results:The rate of therapeutic effect of patients in the high IPAP group was 93.48%,which was significantly higher than 71.88%of the low IPAP group,and the difference between the two groups was statistically significant(x2=6.766,P<0.05).Before treatment,there were no statistically significant differences in indicators included chest compliance(CTh),lung compliance(CL)and total compliance(Ct)between the two groups(P>0.05).After treatment,the Ct,CL and CTh of patients in the high IPAP group were significantly higher than those in the low IPAP group,and the differences between the two groups were statistically significant(t=2.508,2.027,2.185,P<0.05),respectively.There was no statistically significant difference in arterial oxygen partial pressure(PaO2)value between the two groups before used mechanical ventilation(P>0.05).The PaO2 values of patients at 2,4,6 and 8h of using mechanical ventilation in the high IPAP group were significantly higher than those in the low IPAP group,and the differences between different groups were statistically significant(t=8.531,5.296,3.264,4.623,P<0.05),respectively.Both two groups of patients showed a significant increase in inflammatory mediators such as matrix metalloproteinase-9(MMP-9)and interleukin-8(IL-8)during occurring disease.After treatment,the levels of the two mediators decreased,and the high IPAP group was significantly lower than that of low IPAP group(t=2.251,5.484,P<0.05),respectively.The incidence of abdominal distension in patients of high IPAP group was 20.45%,which was significantly higher than 5.88%of low IPAP group,and the difference between groups was statistically significant(x2=3.623,P<0.05).Conclusion:The IPAP of BiPAP ventilator parameters has effect on chest lung compliance,arterial blood gas analysis and inflammatory indicators in AECOPD patients.High IPAP can improve therapeutic effect,and improve chest lung compliance and arterial blood gas analysis,but can easily cause adverse reactions such as abdominal distension.

Identification of Dalbergia odorifera and Its Counterfeits by HS-GC-MS / 中国实验方剂学杂志

ObjectiveTo screen the differential markers by analyzing volatile components in Dalbergia odorifera and its counterfeits， in order to provide reference for authentication of D. odorifera. MethodThe volatile components in D. odorifera and its counterfeits were detected by headspace gas chromatography-mass spectrometry（HS-GC-MS）， and the GC conditions were heated by procedure（the initial temperature of the column was 50 ℃， the retention time was 1 min， and then the temperature was raised to 300 ℃ at 10 ℃ for 10 min）， the carrier gas was helium， and the flow rate was 1.0 mL·min-1， the split ratio was 10∶1， and the injection volume was 1 mL. The MS conditions used electron bombardment ionization（EI） with the scanning range of m/z 35-550. The compound species were identified by database matching， the relative content of each component was calculated by the peak area normalization method， and principal component analysis（PCA）， orthogonal partial least squares-discrimination analysis（OPLS-DA） and cluster analysis were performed on the detection results by SIMCA 14.1 software， and the differential components of D. odorifera and its counterfeits were screened out according to the variable importance in the projection（VIP） value>2 and P<0.05. ResultA total of 26， 17， 8， 22， 24 and 7 volatile components were identified from D. odorifera， D. bariensis， D. latifolia， D. benthamii， D. pinnata and D. cochinchinensis， respectively. Among them， there were 11 unique volatile components of D. odorifera， 6 unique volatile components of D. bariensis， 3 unique volatile components of D. latifolia， 6 unique volatile components of D. benthamii， 8 unique volatile components of D. pinnata， 4 unique volatile components of D. cochinchinensis. The PCA results showed that， except for D. latifolia and D. cochinchinensis， which could not be clearly distinguished， D. odorifera and other counterfeits could be distributed in a certain area， respectively. The OPLS-DA results showed that D. odorifera and its five counterfeits were clustered into one group each， indicating significant differences in volatile components between D. odorifera and its counterfeits. Finally， a total of 31 differential markers of volatile components between D. odoriferae and its counterfeits were screened. ConclusionHS-GC-MS combined with SIMCA 14.1 software can systematically elucidate the volatile differential components between D. odorifera and its counterfeits， which is suitable for rapid identification of them.

Correlation between neonatal retinal hemorrhage and changes in umbilical artery blood gas analysis / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To explore the correlation between neonatal retinal hemorrhage(RH)and changes in umbilical artery blood gas analysis.METHODS: A total of 312 full-term neonates born in our obstetrics department from January 2019 to December 2021 were selected as the study subjects. According to the RetCam III fundus examination results, 245 neonates who did not experience RH were included in the control group, while 67 cases with RH were found to be included in the RH group. In addition, neonates were grouped into I degree group(n=20), II degree group(n=29), and III degree group(n=18)based on the degree of RH. General clinical data and umbilical artery blood gas analysis indicators between the RH group and the control group were compared; the levels of umbilical artery blood gas analysis indicators in neonates with different degrees of RH, the relationship between pH and RH degree, and the influencing factors of neonatal RH were analyzed.RESULTS: There was no obvious difference in maternal age, average gestational week, fetal gender, parity, gestational diabetes, fetal birth weight, and amniotic fluid between the RH group and the control group(all P&#x003E;0.05), while there were obvious differences in delivery methods, gestational hypertension, forceps assisted delivery, neonatal asphyxia, and umbilical cord around the neck(all P&#x003C;0.05). The pH value, arterial blood sample partial pressure(PaO2)and base excess(BE)values of the RH group were obviously lower than those of the control group(all P&#x003C;0.01), while the arterial carbon dioxide partial pressure(PaCO2)was obviously higher than that of the control group(P&#x003C;0.01). There were obvious differences in umbilical artery blood gas analysis indicators among children with different degrees of RH(P&#x003C;0.05), and with the increase of the degree of RH, pH value, PaO2 and BE gradually decreased(P&#x003C;0.05), and PaCO2 gradually increased(P&#x003C;0.05). There was a negative correlation between the degree of RH and the pH of umbilical artery blood gas analysis(rs=-0.593, P&#x003C;0.05). The results of multivariate Logistic regression analysis showed that delivery method, gestational hypertension, forceps assisted delivery, neonatal asphyxia, umbilical cord entanglement, pH, PaO2, PaCO2, and BE were all influencing factors for the occurrence of neonatal RH.CONCLUSION: There is a close correlation between neonatal RH and changes in umbilical artery blood gas analysis, and umbilical artery blood gas analysis can be used for the diagnosis of neonatal RH, which can be used to guide clinical treatment.

Detection of 14 sulfonate esters impurities of active pharmaceutical ingredients based on GC-MS/MS and LC-MS/MS / 药学学报

Two methods including gas chromatography tandem mass spectrometry (GC-MS/MS) and high-performance liquid chromatography tandem mass spectrometry (LC-MS/MS) were established to detect common alkyl sulfonates and aryl sulfonates genotoxic impurities. Four alkyl sulfonates and methyl benzenesulfonate were determined by GC-MS/MS using butyl methanesulfonate as the internal standard, the chromatographic column was HP-5MS UI (30 mm × 0.25 mm, 0.25 µm), the carrier gas was helium, the flow rate was 1.0 mL·min-1 in a constant flow mode, the sample inlet temperature was set to 250 ℃, the split ratio was 10∶1, and the initial temperature of the heating program was 80 ℃, maintained for 1 minute, and then increased to 240 ℃ at a heating rate of 30 ℃·min-1 for 2 minutes. The mass spectrometry detector was an electron bombardment ion source (EI source), the data collection condition was multi reaction monitoring mode (MRM), and method validation using the raw material of clinical drug citalopram hydrobromide as a sample. The results showed that the linear range of four alkyl sulfonates and methyl benzenesulfonate were good at 3-50 ng·mL-1 and 9-150 ng·mL-1, with a correlation coefficient of r > 0.999, The spiked recovery was 80%-120%. The detection limits were 1 and 3 ng·mL-1; Ten aryl sulfonates determined by LC-MS/MS, the chromatographic column was CSH Fluoro phenyl (100 mm × 2.1 mm, 1.7 µm), the mobile phase was methanol (B)-5 mmol·L-1 ammonium formate (D), with a flow rate of 0.2 mL·min-1, and gradient elution was performed. The gradient program (T/% B) was set as 0/20, 25/90, 35/90, 42/20. The mass spectrometer detector was electro spray ionization with positive ionization mode (ESI+), the data collection was in dynamic multi reaction monitoring mode (dMRM), and the method was validated using the raw material of the clinical drug citalopram hydrobromide as a sample. The results showed that the linear range of aryl sulfonates were good at 9-2 000 ng·mL-1, 3-100 ng·mL-1 and 0.9-30 ng·mL-1, respectively. The correlation coefficient r > 0.999, the spiked recovery was 80%-120%. The detection limits were 30, 1 and 0.3 ng·mL-1. Two detection methods did not detect potential sulfonate genotoxicity impurities in the above APIs. The established analytical methods are reliable and effective, which can provide reference for drug quality control and detection.

Determination of 27 volatile organic compounds in exhaled breath by thermal desorption-gas chromatography-mass spectrometry / 环境与职业医学

Background Volatile organic compounds (VOCs) in exhaled breath are closely associated with respiratory diseases and are linked to various metabolic reactions in the human body. A quantitative analytical method can provide technical support for studying VOCs related to various diseases. Objective To establish a thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) method for the determination of 27 VOCs in exhaled breath. Methods VOCs in exhaled breath were collected using a Bio-VOC sampler and enriched with Tenax TA thermal desorption tubes before TD-GC-MS analysis. Standards were collected using thermal desorption tubes and optimized for thermal desorption conditions as well as chromatographic and mass spectrometric conditions: The separation of the 27 VOCs was achieved by an optimized temperature program, the improvement of sensitivity by optimizing quantitative ions, and the increase of VOCs desorption efficiency by optimizing thermal desorption time and temperature. Limit of detection, limit of quantification, accuracy, precision, and stability of the proposed method were investigated by spiking with a blank gas bag, and exhaled breath samples from 20 healthy individuals were collected for an application study of the proposed method. Results The thermal desorption temperature was 280 ℃, and desorption time was 6 min. A VF-624ms chromatographic column was selected for the separation of target substances. The initial temperature of heating program was 35 ℃, maintained for 1 min, and then increased to 100 ℃ at a heating rate of 3 ℃·min−1 for 1 min, followed by increasing to 210 ℃ at a heating rate of 28 ℃·min−1 for 5 min. A quantitative analysis was conducted with a single ion monitoring (SIM) mode. Under these conditions, the 27 VOCs showed good linear relationships in their respective concentration ranges and the correlation coefficients were higher than 0.9990. The limits of detection of the method were in the range of 0.01-0.13 nmol·mol−1, the limits of quantification were in the range of 0.02-0.44 nmol·mol−1, and the spiked recoveries were in the range of 80.1%-120.5%, with intra-batch and inter-batch precision ≤ 18.8% and 17.9% respectively. All substances can be stored at room temperature (23-28 °C) for 7 d and at 4 °C for 14 d. The proposed method was applied to exhaled breath samples from 20 subjects with detection rates≥ 80% (except for trans-2-pentene and decane) and a concentration range of 0.00-465.50 nmol·mol−1. Conclusion The established TD-GC-MS method for quantification of VOCs in exhaled breath is characterized by high sensitivity and good accuracy, and is suitable for quantitative determination of VOCs in exhaled breath, which can provide technical support for the study of exhaled breath VOCs.

Gain deeper insights into traditional Chinese medicines using multidimensional chromatography combined with chemometric approaches / 中草药·英文版

Traditional Chinese medicines (TCMs) possess a rich historical background, unique theoretical framework, remarkable therapeutic efficacy, and abundant resources. However, the modernization and internationalization of TCMs have faced significant obstacles due to their diverse ingredients and unknown mechanisms. To gain deeper insights into the phytochemicals and ensure the quality control of TCMs, there is an urgent need to enhance analytical techniques. Currently, two-dimensional (2D) chromatography, which incorporates two independent separation mechanisms, demonstrates superior separation capabilities compared to the traditional one-dimensional (1D) separation system when analyzing TCMs samples. Over the past decade, new techniques have been continuously developed to gain actionable insights from complex samples. This review presents the recent advancements in the application of multidimensional chromatography for the quality evaluation of TCMs, encompassing 2D-gas chromatography (GC), 2D-liquid chromatography (LC), as well as emerging three-dimensional (3D)-GC, 3D-LC, and their associated data-processing approaches. These studies highlight the promising potential of multidimensional chromatographic separation for future phytochemical analysis. Nevertheless, the increased separation capability has resulted in higher-order data sets and greater demands for data-processing tools. Considering that multidimensional chromatography is still a relatively nascent research field, further hardware enhancements and the implementation of chemometric methods are necessary to foster its robust development.

Determination of Isobutyl Chloroformate Residue in Agatroban by Derivatization-Gas Chromatography-Mass Spectrometry / 分析化学

A derivatizaton method combined with gas chromatography-mass spectrometry(GC-MS)was established for detection of isobutyl chloroformate(IBCF)residue in active pharmaceutical ingredient of agatroban.The extraction and derivatization reagents,derivatization time,qualitative and quantitative ions were selected and optimized,respectively.The possible mechanism of derivatization and characteristic fragment ions fragmentation were speculated.The agatroban samples were dissolved and extracted by methanol,and the residual IBCF was derived with methanol to generate methyl isobutyl carbonate(MIBCB).After 24 h static derivatization at room temperature,IBCF was completely transformed into MIBCB,which could be used to indirectly detect IBCF accurately.The results showed that the linearity of this method was good in the range of 25-500 ng/mL(R2=0.9999).The limit of detection(LOD,S/N=3)was 0.75 μg/g,and the limit of quantification(LOQ,S/N=10)was 2.50 μg/g.Good recoveries(95.2%-97.8%)and relative standard deviations(RSDs)less than 3.1%(n=6)were obtained from agatroban samples at three spiked levels of IBCF(2.50,25.00,50.00 μg/g),which showed good accuracy of this method.Good precision of detection results was obtained by different laboratory technicians at different times,the mean value of spiked sample solution(25.00 μg/g)was 24.28 μg/g,and the RSD was 2.1%(n=12).The durability was good,minor changes of detection conditions had little effect on the results.Under the original condition and conditions with initial column temperature±5℃,heating rate±2℃/min,column flow rate±0.1 mL/min,the IBCF content of spiked sample solution(25.00 μg/g)was detected,the mean value of detection results was 24.16 μg/g,and the RSD was 2.2%(n=7).Eight batches of agatroban samples from two manufacturers were detected using the established method,and the results showed that no IBCF residue was detected in any of these samples.The agatroban samples could be dissolved by methanol,and then the IBCF residue could be simultaneously extracted and derived with methanol as well.This detection method had the advantages of simple operation,high sensitivity,low matrix effect and accurate quantification,which provided a new effective method for detection of IBCF residue in agatroban.

Identification and diagnostic value of characteristic volatile organic compounds in exhaled breath of mice with early stage radiation injury / 军事医学

Objective To investigate the characteristic volatile organic compounds(VOCs)in exhaled breath and their diagnostic value in mice with early stage radiation injury.Methods The thermal desorption gas chromatography-mass spectrometry(TD-GC/MS)technique was used to analyze VOCs in exhaled breath of irradiated mice by 60Coγ-ray with 800 cGy.The characteristic VOCs in the early stage of radiation injury were identified,and a diagnostic model was established.Results The 30-day survival rate of mice was 4.2%.There were significant differences in characteristic VOCs at 7 hours after radiation injury,and thirty characteristic VOCs related to early-stage radiation injury were identified.The diagnostic value of differential metabolites in mice after irradiation was evaluated via the ROC curve,and the area under the ROC curve(AUC)of a single compound exceeded 0.8.The diagnostic model was constructed by screening 9 potential biomarkers of exhalation through Fisher discriminant analysis,and its sensitivity and specificity were close to 100%.Conclusion Analysis of VOCs in exhaled breath is expected to provide a non-invasive diagnostic method for early screening and diagnosis of radiation injury.

The effects of gastrodin on TLR4 expression in microglia induced by ischemia and hypoxia / 神经解剖学杂志

Objective:To determine the effect of gastrodin(GAS)on toll-like receptor 4(TLR4)expression in mi-croglia after hypoxic-ischemic brain damage.Methods:Hypoxia-ischemic brain damage(HIBD)model was established in neonatal rat in vivo.Thirty 3 d SD rats of were randomly divided into there groups:Sham group,HIBD model group,HIBD model+gastrodin intervention group(HIBD+G).Oxygen glucose deprivation(OGD)model was established in BV2 cells in vitro,Control group(Control),oxygen glucose deprivation group(OGD),OGD+gastrodin intervention group(OGD+G)were randomly set in vitro.Both Western Blot and immunofluorescence staining techniques were used to detect the expression of TLR4 in cells of each group in vitro and in the left corpus callosum region in vivo.Results:The expression of TLR4 was significantly increased in OGD-induced microglia.After gastrodin intervention,TLR4 expression was decreased significantly(P＜0.05).Conclusion:GAS can inhibit the expression of TLR4 in activated microglia and thus play a neuroprotective role in HIBD.

Clinical efficacy of LISA technology in the treatment of neonatal respiratory distress syndrome and its influence on blood gas analysis / 中国现代医生

@#Objective To investigate the treatment of neonatal respiratory distress syndrome by less invasive surfactant administration(LISA)clinical efficacy,complications and influence on blood gas analysis.Methods A total of 100 cases of neonatal respiratory distress syndrome requiring pulmonary surfactant(PS)tracheal injection therapy and admitted to the Jinhua Central Hospital between December 1st 2019 and August 1st 2022 were randomly assigned into treatment group(50 cases)and control group(50 cases).The treatment group of children received PS treatment using LISA technology,while the control group of children received PS treatment using tracheal intubation tracheal instillation PS extubation followed by intubation-surfactant-extubation technology.The clinical treatment effect,blood gas analysis,non-invasive ventilation time,length of hospitalization,and incidence of complications were compared between the two groups.Results The total effective rate of treatment in the treatment group was higher than that in the control group;After 1 hour of PS treatment,the oxygen partial pressure and blood oxygen saturation of the treatment group were higher than those of the control group,while the carbon dioxide partial pressure was lower than that of the control group.The non-invasive assisted ventilation time of the treatment group was shorter than that of the control group.The incidence of bronchopulmonary dysplasia was lower than that of the control group.Their difference were statistically significant(P<0.05).Conclusion The use of LISA technology for PS treatment of NRDS can improve blood gas indicators,shorten non-invasive ventilation time,improve diagnostic and therapeutic effects,reduce the risk of bronchopulmonary dysplasia,and do not increase the incidence of complications such as tracheal mucosal injury and pulmonary hemorrhage in children.

Refractive reconstruction of keratoconus / 国际眼科杂志(Guoji Yanke Zazhi)

Keratoconus is a progressive disease that seriously affects the eyesight of young people. Keratoconus often causes high myopia, irregular astigmatism, and some patients with advanced corneal scar, visual acuity significantly decreased. In the course of diagnosis and treatment of keratoconus, refractive reconstruction of keratoconus is the focus of clinical attention. After years of research and exploration, a variety of treatment methods in different stages of disease(non-progressive, progressive, advanced)for keratoconus patients refractive reconstruction, so that they can obtain good visual function. This paper mainly reviews the refractive reconstruction schemes of keratoconus in different periods, analyzes the advantages and disadvantages of various treatment schemes at home and abroad, and summarizes the characteristics of different treatment methods, with a view to providing theoretical reference and new treatment ideas for the diagnosis and treatment of keratoconus.

Determination of two isomers of tetrachloroethane in urine by liquid-liquid extraction-gas chromatography / 中国职业医学

ObjectiveTo establish a method for the determination of 1,1,1,2-tetrachloroethane (TeCA) and 1,1,2,2-TeCA in human urine using liquid-liquid extraction-gas chromatography. Methods The 5.0 mL urine sample was mixed with 2.0 g anhydrous sodium sulfate and 5.0 mL ethyl acetate, then vortexed mixing. The 1.0 mL extraction was separated by 100% dimethylpolysiloxane capillary gas chromatography column, detected by flame ionization detector, and quantified by an external standard method. Results The linear ranges of 1,1,1,2-TeCA and 1,1,2,2-TeCA were 0.250-50.750 mg/L, with both correlation coefficients of >0.999 9. The detection limit of 1,1,1,2-TeCA in urine was 0.020 mg/L, and the lower limit of quantification was 0.060 mg/L. The average recovery was 88.02%-101.32%, and the within-run and between-run relative standard deviations (RSDs) were 0.11%-0.47% and 0.39%-1.09%, respectively. The detection limit of 1,1,2,2-TeCA in urine was 0.050 mg/L, and the lower limit of quantification was 0.150 mg/L. The average recovery was 93.42%-101.32%, and the within-run and between-run RSDs were 0.28%-1.04% and 0.50%-1.03%, respectively. Both the 1,1,1,2-TeCA and 1,1,2,2-TeCA cannot be stored at room temperature. The 1,1,2,2-TeCA can be stored at 4 ℃ for at least three days. At -20 ℃, the 1,1,1,2-TeCA can only be stored for one day, while 1,1,2,2-TeCA can be stored for at least five days. Conclusion This method has high sensitivity, good specificity, simple sample pretreatment, and more intuitive and reliable results. It can be used to determine the level of 1,1,1,2-TeCA and 1,1,2,2-TeCA in urine of occupational population.

Chemical Composition Analysis and Repellent Activity Evaluation of Compound Mosquito Repellent Essential Oil / 浙江中医药大学学报

[Objective]To analyze the chemical components of the compound essential oil for mosquito repellent,which was composed of Menthae haplocalyx Briq.,Spirodela polyrrhiza(L.)Schleid,Acorus tatarinowii Schott and Rosmarinus offiicinalis L.,and to evaluate its repellent effect.[Methods]The chemical components of the compound mosquito repellent essential oil were analyzed by gas chromatography-mass spectrometer(GC-MS),and the repellent activity of the essential oil against adult Aedes albopictus was evaluated according to the"Efficacy Test and Evaluation of Space Repellent Products(Y-tube Method)".[Results]Fifty-eight main volatile components were identified,accounting for 98.28％of the total components of essential oil,eighteen terpenes(44.99％),nine alkenes(20.27％),five esters(14.07％),eight aromatic hydrocarbons(12.00％),seven alkanes(3.48％),nine alcohols(2.78％),two ketones(0.69％).The percent repellency(PR)of the compound mosquito repellent essential oil against Aedes albopictus was more than 90％on average.[Conclusion]There were many chemical components in the compound mosquito repellent essential oil.There may be a variety of chemical components such as menthol,menthone,α-pinene,etc,which had a repellent effect on Aedes albopictus,and the average repellent effect reached the A level.

Propylene glycol monomethyl ether isomers in workplace air determined by solvent desorption-gas chromatography / 环境与职业医学

Background Propylene glycol monomethyl ether (PGME) is a widely used organic solvent. It exists in the form of two isomers in the workplace, which will cause adverse effects such as eye and upper respiratory tract irritation in workers. However, there is still a lack of standard detection methods for simultaneous detection of two isomers of PGME in China. Objective To establish a solvent desorption-gas chromatographic method for two isomers of PGME [1-methoxy-2-propanol (α-PGME), 2-methoxy-1-propanol (β-PGME)] in workplace air. Methods A method of solvent desorption-gas chromatography for α-PGME and β-PGME in workplace air were proposed. Air samples were collected with solvent desorption activated carbon tubes, desorbed using a desorption solution of dichloromethane/methanol (85:15), and then separated on a free fatty acid phase (FFAP) fused silica capillary chromatography column , detected with a flame ionization detector (FID), and quantified by peak area. Standard evaluation protocol was followed to obtain key indicators: standard curve, limit of detection, lower limit of quantification, relative standard deviation (RSD) that measures precision, and spiked recovery of sample solutions that measures accuracy. Desorption efficiency, sampling efficiency, and adsorption capacity tests were conducted, sample stability was evaluated using spiked activated carbon tube preservation test, and interference test was also assessed. The developed method was then applied to field air sample testing. Results In this method, using dichloromethane/methanol (85:15) as the sample desorption solution, the quantitative detection ranges of α-PGME and β-PGME were 0.95-923.0 μg·mL−1 and 0.97-912.0 μg·mL−1 with both correlation coefficients of 0.999 9, the method limits of detection were 0.28 µg·mL−1 and 0.29 µg·mL−1, and the lower limits of quantification were 0.95 µg·mL−1 and 0.97 µg·mL1, respectively. The lowest concentrations detected were both 0.19 mg·m−3, and the lowest concentrations quantified were 0.63 mg·m−3 and 0.65 mg·m−3, respectively, under the conditions of sampling volume of 1.5 L and the volume of desorption solution of 1.0 mL. The intra-batch precisions for α-PGME and β-PGME were 2.8%-4.9% and 2.8%-5.1%, the inter-batch precisions were 4.2%-5.7% and 4.5%-5.9%, the spiked recoveries were 98.8%-100.3% and 96.4%-102.9%, and the desorption efficiencies were 92.7%-97.3% and 92.2%-98.1%, respectively. The average sampling efficiency was 100%, and the samples could be stored at room temperature (25-30 ℃) for at least 7 d and at 4 ℃ for at least 15 d. The adsorption capacities of the activated carbon sampling tube for α-PGME and β-PGME were greater than 13.9 mg and 2.7 mg (100 mg of activated carbon adsorbent), respectively. Possible co-existing components in workplace did not interfere with the determination of α-PGME and β-PGME. The short-time exposure concentrations of α-PGME and β-PGME in the spray painting unit of an automobile manufacturing company were determined to be 18.69 mg·m−3 and 2.19 mg·m−3, and the time-weighted average concentrations were 6.03 mg·m−3 and 1.08 mg·m−3 respectively. Conclusion This method is accurate, precise and suitable for on-site monitoring of the two isomers of PGME in workplace air.

Ocular surface changes in keratoconus after long-term wearing of rigid gas permeable contact lens / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To analyze changes in the ocular surface parameters of keratoconus after long-term wearing of rigid gas permeable contact lens(RGPCL).METHODS:Prospective case study. A total of 113 keratoconus patients(213 eyes)fitted with RGPCL in the optometry center of Gansu Provincial Hospital from January 2018 to January 2022 were included. They were divided into three groups according to the severity of keratoconus, including 42 cases(80 eyes)in mild keratoconus group, 54 cases(102 eyes)in moderate keratoconus group and 17 cases(31 eyes)in severe keratoconus group. Furthermore, the non-invasive tear break-up time(NIBUT), non-invasive tear meniscus height(NITMH), red eye index, lipid layer thickness, fluorescent corneal staining, meibomian gland secretory function, Schirmer I test and ocular surface disease index(OSDI)scores were observed by Keratograph analyzer before and after wearing RGPCL for 1 wk, 1, 3, 6, 12 mo, respectively.RESULTS: There were no statistical significance in the age, NIBUT, NITMH, lipid layer thickness, meibomian gland secretory function and Schirmer I test among the three groups(P&#x003E;0.05), while there were statistical significance in the sphere, cylinder, spherical equivalent, best corrected visual acuity(BCVA), non-contact intraocular pressure(IOPNCT), anterior, posterior corneal surface Kmax, corneal surface thickness at the thinnest point, eye redness index, fluorescent corneal staining, and OSDI(P&#x003C;0.05). In the mild keratoconus group, NIBUT had statistical differences at 3, 6 and 12 mo after wearing RGPCL(P&#x003C;0.05), NITMH had statistical differences in 6 and 12 mo(P&#x003C;0.05), the eye redness index, fluorescent corneal staining and OSDI scores had statistical differences in 1 wk and 1 mo(P&#x003C;0.05), and lipid layer thickness and meibomian gland secretory function had statistical differences in 12 mo(P&#x003C;0.05). In the moderate keratoconus group, there were statistical differences in NIBUT at 6 and 12 mo after wearing lenses(P&#x003C;0.05); there were statistical differences in the NITMH, lipid layer thickness and meibomian secretory function at 12 mo after wearing lens(P&#x003C;0.05); there were statistical differences in the eye redness index at 1 wk, 1 and 3 mo after wearing RGPCL(P&#x003C;0.05); there were statistical differences in the fluorescent corneal staining at 1 wk after wearing RGPCL(P&#x003C;0.05); there were statistical differences in the OSDI at 1 wk and 1 mo after wearing RGPCL(P&#x003C;0.05). In the severe keratoconus group, there were statistical differences in the NIBUT, NITMH and eye redness index at 1 wk, 1, 3, 6 and 12 mo after wearing RGPCL(P&#x003C;0.05); there were statistical differences in the lipid layer thickness at 6,12 mo after wearing RGPCL(P&#x003C;0.05); there were statistical differences in the fluorescent corneal staining and OSDI scores at 1 wk, 6 and 12 mo after wearing RGPCL(P&#x003C;0.05); there were statistical differences in the meibomian secretory function at 6 and 12 mo after wearing RGPCL(P&#x003C;0.05); and there were statistical differences in the Schirmer I test at 12 mo after wearing RGPCL(P&#x003C;0.05).CONCLUSION: Long-term wearing of RGPCL can affect the ocular surface microcirculation in keratoconus patients, thus making differences in patients subjective. However, it has no significant impact on the visual quality of patients. Therefore, long-term wearing of RGPCL is safely to control the progression of keratoconus.

Advance in preparation methods of bone tissue engineering scaffolds / 中国组织工程研究

BACKGROUND:Due to the small number of autologous bone sources and the risk of immune rejection and disease spread caused by the use of allogeneic bone,artificial bone materials have played an irreplaceable role in bone transplantation today.Along with functional customization,biocompatibility requirements,and the emergence of biodegradable materials,a variety of biomaterials and a variety of preparation methods have emerged. OBJECTIVE:To summarize the preparation methods of scaffolds used in bone tissue engineering,and the advantages and disadvantages,research status and progress of various preparation methods. METHODS:A computer search was conducted on CNKI,WanFang Data,PubMed,and ScienceDirect databases for literature related to bone tissue engineering scaffold from January 2008 to August 2023.Chinese and English search terms were"tissue engineering,bone scaffold,gas foaming,cryotropic gelation,additive manufacturing".After excluding irrelevant and repetitive studies,a total of 80 articles were retained for summary. RESULTS AND CONCLUSION:(1)Compared with the traditional preparation process of scaffolds,the emerging additive manufacturing and electrospinning technologies have shown great potential in the production of complex structures such as bone and cartilage for tissue engineering in recent years,demonstrating enormous potential.(2)In addition to the advantages of speed,precision and the range of materials used,additive manufacturing methods also provide the feasibility of manufacturing highly complex geometry and topologically optimized structures,achieving precise adjustment and high repeatability of the structure.(3)Electrospinning is one of the most adaptable and promising technologies for the production of a series of fiber mats.The nanofiber scaffolds produced by electrospinning are biomaterials with surprisingly similar microstructures to the cytoplasmic matrix.(4)At present,hydroxyapatite and tricalcium phosphate are the best in ceramic materials,and there are a variety of materials in polymer materials,with excellent biocompatibility.(5)Therefore,the selection of materials should be based on a better understanding of their properties,avoiding complexity,and producing more enhanced scaffolds.However,most of the literature reports so far are exploratory in terms of clinical applicability,and the specific diseases for which they are suitable for treatment remain to be tested.The future development of bone scaffolds is reflected in the following aspects:mechanical properties matching the missing bone,controllable degradation rate,strong ability to promote bone regeneration,and specific functions.

Effect of hydrogen-rich gas on proprioception and muscle endurance after high-intensity exercise / 中国组织工程研究

BACKGROUND:Hydrogen,as an antioxidant,can reduce oxidative stress induced by strenuous exercise and achieve the effect of improving fatigue.Several studies have been reported on the potential effects of hydrogen-rich water or hydrogen-rich gas on improving exercise fatigue and athletic performance. OBJECTIVE:To investigate the effects of hydrogen-rich gas inhalation prior to high-intensity exercise on proprioception and muscular endurance performance after exercise fatigue. METHODS:Through a randomized,double-blind,crossover,and repeated measurement experimental design,24 healthy men were randomly divided into group A and group B,with 12 in each group.In the first phase of the crossover experiment,group A inhaled hydrogen-rich gas(hydrogen group)for 20 minutes and group B inhaled placebo gas(air;placebo group)for 20 minutes.Then,cycle ergometers were used to establish the fatigue model.Visual analog fatigue scale,heart rate variability,knee joint proprioception(passive position perception,joint motion perception,and muscle force perception)and isometric knee extension muscle endurance were tested before and after intervention.After a 7-day washout period,two groups exchanged intervention methods and the above tests were performed again in the second phase of the experiment.Differences between the results of groups A and B in the two phases were compared,and finally the results of the two phases were integrated to compare the overall differences between hydrogen intervention and placebo intervention. RESULTS AND CONCLUSION:In the first phase of the crossover experiment,the visual analog fatigue scale score of the hydrogen group after intervention was significantly lower than that of the placebo group(P<0.01).The root mean square of the difference between the adjacent R-R,mean low-frequency output power,mean high-frequency output power,and isometric muscle endurance after intervention in the hydrogen group were significantly higher than those in the placebo group(P<0.05).Passive position perception and joint motion perception after intervention in the hydrogen group were significantly better than those in the placebo group(P<0.05).There was no significant difference in muscle force perception between the two groups(P>0.05),but muscle force perception in the placebo group after intervention was significantly worse than that before intervention(P<0.01).The difference trend of all test results after intervention in the two groups in the first phase of the experiment showed the same results in the second phase of the experiment.The integrated results also showed that the hydrogen group had better test values for the above indicators than the placebo group(P<0.05).Linear regression analysis showed a positive correlation between post-intervention visual analog fatigue scale scores and passive position perception results(r=0.327,P=0.023),i.e.,the higher subjective fatigue level after high-intensity exercise indicated the worse passive position perception results.To conclude,inhaling hydrogen-rich gas before high-intensity exercise can reduce the degree of fatigue after exercise,thereby improving proprioception and muscle endurance performance,which may be a new strategy to reduce the occurrence of injury.And its effectiveness can be achieved repeatedly.

The value of high-frequency ultrasonography in diagnosing the surgical treatment of neonatal necrotizing enterocolitis / 中国新生儿科杂志

Objective:To determine the predictive value of high-frequency ultrasonography for necrotizing enterocolitis (NEC) requiring surgical treatment in neonates.Methods:From January 2018 to December 2021, neonates diagnosed with NEC (Bell stage Ⅱ and above) in our hospital were retrospectively analyzed. The neonates were assigned into surgical group and non-surgical group according to the treatment. The following ultrasonography results were compared between the two groups: intestinal motility, gastrointestinal (GI) wall perfusion, pneumatosis intestinalis (PI), portal vein gas, peritoneal effusion translucency, depth of ascites fluid and GI wall thickness. Logistic regression was used to determine risk factors of surgical treatment for NEC. ROC curve was drawn to calculate the predictive value of combined and individual factors for NEC requiring surgical treatment.Results:A total of 40 neonates were enrolled, including 18 in the surgical group and 22 in the non-surgical group. No significant differences existed between the two groups in PI and depth of ascites fluid ( P>0.05). The surgical group had higher incidences of decreased intestinal motility, portal vein gas, reduced GI wall perfusion, poor peritoneal effusion translucency and thinner GI wall than the non-surgical group (all P<0.05). Logistic regression analysis showed that poor translucency of peritoneal effusion, thinning of GI wall, reduced GI wall perfusion and decreased intestinal motility were risk factors for surgical treatment of NEC. ROC curve showed that the cut-off value predicting surgical treatment based on GI wall thickness was 1.2 mm, with an area under the curve (AUC) of 0.746, sensitivity of 87.5% and specificity of 65.6%. The AUC of the combined factors predicting surgical treatment was 0.867, with sensitivity of 96.9% and specificity of 75.8%. Conclusions:Decreased intestinal motility and GI wall perfusion, thinning of GI wall and poor peritoneal effusion translucency on high-frequency ultrasonography have high predictive efficacy for the need of surgical treatment in the acute phase of NEC.