Teaching Research and Effect Observation on the Integration of Clinical Medicine Integrated Course and Ideological and Political Elements from the Perspective of“Sanquan Education”

Purpose:To analyze the application path of the integration of clinical medicine integrated courses with the elements of ideology and politics under the theory of“Sanquan Education,”and to provide references for the promotion of educational reform in medical schools.Methods:60 clinical medicine undergraduates at Jiamusi University in 2018 and 2019 were randomly selected as research subjects.On the basis of the analysis of students’characteristics and pre-study content,the students were divided into the integration group and the traditional group,each with 30 students.Students in the integration group carried out clinical medicine integrated class with the integration of ideological and political elements.Students in the traditional group carried out the traditional clinical medicine integrated class.Classroom evaluation scales,anonymous questionnaires,and interviews were used to conduct research,collect data,and compare and observe the application effects.Results:After carrying out different modes of clinical medicine integrated courses,the undergraduates of the Excellent Physician Class in the integration group were higher than those in the traditional group in terms of teaching satisfaction,comprehensive quality,basic knowledge test,and case analysis scores through questionnaire analysis(P<0.05).In the evaluation of the effect of ideological education,the undergraduates of the Excellent Physician Class of the integration group were higher than the traditional group in terms of the acceptance of doctor-patient communication,the correct rate of mastering the history of the discipline,and the correct rate of mastering the frontiers and policies(P<0.05).Conclusion:Through the integration of clinical medicine integrated course and ideological and political elements,we can help students establish correct values while teaching them professional knowledge,improve the implementation of moral education in medical schools,cultivate excellent medical workers with high morality and firm beliefs for the society,and realize the fundamental educational task of establishing morality and educating people in medical schools in the context of“Sanquan Education.”

Effects of dissolved oxygen on intestinal bacterial community and immunity of Atlantic salmon Salmo salar

Dissolved oxygen(DO)is one of most important factors which affect wide range physiologic features of including immune responses and intestinal bacterial community.However,the underlying mechanisms remain enigmatic.To address this question,the intestinal bacterial community compositions and the immune features of Atlantic salmon(Salmo salar)grown in recirculating aquaculture systems(RAS)were characterized.Fish were reared under different DO saturation levels,e.g.,200% saturation named high group(H),100%saturation named control group(CK),and 60%saturation named lower group(L).Large variations in the operational taxonomic units(OTUs)frequency distribution for the intestinal bacterial community of Atlantic salmon were observed.The intestinal bacterial community of all groups was dominated mainly by three phyla,e.g.,Proteobacteria.Firmicutes,and Bacteroidetes.Interestingly,Acinetobacter baumannii,an opportunistic pathogen of salmon was increased significantly in L group.We further monitored the immunity features of fish under different DO levels.The results show that leucocyte number,cortisol level,the expressions of interleukin-1β(IL-1β),Toll-like receptor 4(TLR4),and nucleotide-binding oligomerization domain like protein 2(NOD2)were higher at significant levels in the L group than those in the other two groups.TLR4 and NOD2 are usually related with the bacterial infections;therefore,it is reasonable to believe that the stronger immune responses observed in the L group might be related with the higher abundance of A.baumannii in the inte stine of Atlantic salmon.Overall,these findings demonstrated that low DO level may induce stronger immunity responses in Atlantic salmon.

The ED_(50)of Remazolam Toluenesulfonate Combined with a Subthreshold Dose of Esketamine for Inhibiting Cardiovascular Response to Tracheal Intubation in Elderly Patients

Objective:To explore the half-effective dose(ED_(50))of remazolam toluenesulfonate combined with subthreshold amounts of esketamine for inhibiting cardiovascular response to tracheal intubation in elderly patients.Method:We included 42 patients,aged 65-75,who required general anesthesia and single-lumen endotracheal intubation for elective surgery.The first patient was administered remazolam toluenesulfonate at a dose of 0.20 mg/kg.Once the patient lost consciousness,their alertness/sedation score(OAA/S score)was≤1,and their BIS score was≤60,and a subthreshold dose(0.3 mg/kg)of esketamine was given.The subsequent doses were adjusted using a sequential approach based on the cardiovascular response to tracheal intubation observed in the previous patient.The dose was modified in increments or decrements of 0.01 mg/kg.The ED_(50)and 95%CI of remazolam toluenesulfonate were calculated using the Dixon and Massey sequential distribution test method.Result:The inhibition of endotracheal intubation response was positively correlated with the dose of remazolam toluenesulfonate,and the depth of sedation could not be achieved when the amount was≤0.22 mg/kg.The ED_(50)of remazolam toluenesulfonate combined with a subthreshold dose of esketamine in inhibiting cardiovascular response to tracheal intubation in elderly patients was 0.30(0.28,0.33)mg/kg.There was no statistically significant difference in blood pressure between the induction of anesthesia and before the operation.Conclusion:When compounded with 0.3 mg/kg esketamine,the ED_(50)of Remazolam toluenesulfonate in inhibiting cardiovascular response to endotracheal intubation in elderly patients was 0.30 mg/kg(95%CI0.28-0.33 mg/kg).

Effects of Continuous Non-Invasive Blood Pressure Monitoring on Intraoperative Hemodynamics and Postoperative Myocardial Injury in Craniotomy:Comparison Between Groups Based on Self-Control and Propensity Score Matching

Objective:To explore the effect of continuous non-invasive blood pressure monitoring on intraoperative hemodynamics and postoperative myocardial injury in craniotomy.Methods:120 cases of elective craniotomy were divided into the self-control group(continuous non-invasive blood pressure monitoring and intermittent cuff non-invasive blood pressure monitoring,CNAP group)and propensity score matching group(only intermittent cuff non-invasive blood pressure measurement in previous craniotomy,PSM group);Goal-directed hemodynamic management in CNAP group included heart rate(HR),blood pressure(BP),stroke volume(SV),stroke variability(SVV),and systemic vascular resistance index(SVRI).The main index is to compare the troponin level within 72 hours after operation between the CNAP group and the PSM group;The secondary indicators are the comparison of the hemodynamic conditions between the CNAP group and the PSM at 10 specific time points.Results:The incidence of postoperative myocardial injury in the CNAP group was significantly lower than that in the PSM group(12%vs.30%,P=0.01);in the CNAP group hypotensive episodes(6 vs.3,P=0.01),positive balance of fluid therapy(700 vs.500 mL,P<0.001),more use of vasoactive drugs(29 vs.18,P=0.04),more stable hemodynamics medical status(P=0.03)were recorded.Conclusion:The hemodynamic management strategy based on continuous non-invasive blood pressure monitoring can reduce the incidence of myocardial injury after elective craniotomy and maintain a more stable hemodynamic state.

Nighttime transpiration of Populus euphratica during different phenophases

Evidence exists of nighttime transpiration and its potential impact on plant/water relations for species in a diversity of ecosystems. However, relevant data related to typical desert riparian forest species remains limited Accordingly, we measured sap flow velocity of Populus euphratica using the heat ratio method between 2012 and2014. Nocturnal stem sap flow was separated into nighttime and stem refilling using the ‘‘forecasted refilling''method. Nighttime transpiration was observed for each phenophase. The highest value was during the full foliation period but lowest during leaf expansion and defoliation periods. The contribution of nighttime transpiration to daytime transpiration was an average of 15% but this was comparatively higher during the defoliation period. Relationships between nighttime transpiration, vapor pressure deficits, and air temperatures were more closely associated than with wind speed in all phenophases. Moreover, we found that nighttime transpiration linearly correlated to vapour pressure deficit during the first and the full foliation periods, but nighttime transpiration showed exponential correlations to air temperatures during the same phenophases. Additionally, environmental drivers of transpiration were significantly different between nighttime and daytime(P \ 0.05). Driving forces behind nighttime transpiration were characterized by many factors, and integrated impacts between these multiple environmental factors were complex. Future studies should focus on these integrated impacts on nighttime transpiration, and the physiological mechanisms of nighttime transpiration should be investigated, given that this could also influence its occurrence and magnitude during different phenophases.

Evapotranspiration of a Populus euphratica Oliv. forest and its controlling factors in the lower Heihe River Basin,Northwest China

Evapotranspiration (ET) within an ecosystem is crucial for die water-limited environment that currently lacks adequate quantification in the arid region of Northwest China, mainly covered by phreatophytes, such as the Populus euphratica Oliv. tree and the Tamarix ramosissima Ledeb. shrub species. Accordingly. ET was measured for an entire year using eddy covariance (EC) in P. euphratica stands in the lower Heihe River Basin, Northwest China. During the growing season, the total ET was 850 mm, with a mean of 4.0 mm/d, Which is obviously more than that observed at tree-level and stand level scales, which was likely due to the different level of soil evaporation induced by irrigation via water conveyance. Factors associated with ET fall into either environmental or plant eco-physiological categories. Environmental factors account for at least 79% variation of ET and the linear relationship between ET and the voundwater table (GWT) revealed the potential water use of P. euphratica forests under the non-water stress condition with die GWT less than 3 m deep. Plant eco-physiological parameters, specifically die leaf area 'index (LAI), have direct impact on the seasonal pattern of ET which provides a valuable reference to the wide-area estimates of ET for riparian forests by using LAI. In conclusion, P. euphratica forests have high water use after water conveyance, which may be the result of long-term adapting to local climates and limited water availability.

Changes of melatonin and its receptors in synchronizing turbot(Scophthalmus maximus)seasonal reproduction and maturation rhythm

In most fish,reproduction is seasonal or periodic under the suitable conditions.In turbot(Scophthalmus maximus)farms,one of the most economically important marine flatfish species,changes in daylength could cause changes in the spawning time.In this study,to characterize the regulation of reproductive physiology following light signals,three melatonin receptors(Mtnr)investigated in turbot were named sm Mtnr1,sm Mtnr2,and sm Mtnr1 c.Distinct expression profiles demonstrated that Mtnr m RNAs were concentrated in the brain(as detected in the hypothalamus(Hy)and mesencephalon(Me)),gonad and eye.The most abundant Mtnr1 and Mtnr2 m RNA expression levels were detected in the central nervous system at the beginning of the breeding season,suggesting that Mtnr1 and Mtnr2 may play vital roles in the regulation of turbot gonadal development.In addition,the melatonin profiles gradually increased and reached to the highest level at the spawning stage,indicating that melatonin is a potent hormone in the regulation of fish oocyte growth and maturation.The results of this study suggested that melatonin is the primary factor that transduces the light signal and regulates the physiological functions of turbot seasonal reproduction.Moreover,the results of this study may establish a foundation for further research seeking to identify fish melatonin receptors involved in the gonadal development and gamete maturation.

Comparable water use of two contrasting riparian forests in the lower Heihe River basin, Northwest China

Understanding forest ecosystem evapotranspiration（ET） is crucial for water-limited environments,particularly those that lack adequate quantified data such as the lower Heihe River basin of northwest China which is primarily dominated by Tamarix ramosissima Ledeb.and Populus euphratica Oliv.forests.Accordingly,we selected the growing season for 2 years （2012 and 2014） of two such forests under similar meteorological conditions to compare ET using the eddy covariance（EC） technique.During the growing seasons,daily ET of T.ramosissima ranged from 0.3 to 8.0 mm day^（-1） with a mean of 3.6 mm day^（-1）,and daily ET of P.euphratica ranged from 0.9 to 7.9 mm day^（-1） with a mean of 4.6 mm day^（-1） for a total of 548 and 707 mm,respectively.The significantly higher ET of the P.euphratica stand was directly linked to high soil evaporation rates under sufficient water availability from irrigation.When the soil evaporation was disregarded,water use was comparable to two contrasting riparian forests,a P.euphratica forest with a total transpiration of 465 mm and a T.ramosissima forest with 473 mm.Regression analysis demonstrated that climate factors accounted for at least 80% of ET variation in both forest types.In conclusion,water use of the riparian forests was low and comparable in this arid region,that suggest the long-term plant adaptation to the local climate and conditions of water availability.

Clinical Study on the Effects of Different Infusion Solutions on Colloid Osmotic Pressure During Major Abdominal Surgery and Perioperative Albumin in Elderly Patients

Objective:To explore the effects of different infusion schemes on colloid osmotic pressure during major abdominal surgery and perioperative albumin in elderly patients.Methods:140 elderly patients of 65-80 years old undergoing major abdominal surgery were divided into 4 groups according to the method of random number table,and different proportions of crystals and colloids were given to different groups(group A:full crystal,group B:crystal-colloid ratio 1:1,group C:crystal-colloid ratio 2:1,Group D:crystalcolloid ratio 1:2).The plasma colloid osmotic pressure and level of albumin during perioperative period were monitored.Simultaneously observe the arterial blood pH,blood glucose,extubating time of endotracheal tube,postoperative feeding time,et al.Results:The total amount of liquid infusion in the group of whole crystal was 3056ml(3056±253),which was significantly more than other groups(P<0.01).At the same time,the colloid osmotic pressure decreased by 11.9 mmHg(11.9±2.8),which was more obviously decreased than that of the other groups(B group3.9±1.3,C group 1.5±0.3,D group 4.7±2.1).The difference was a statistically significant(P<0.01).On the next day after surgery,the level of albumin decreased by an average of 4.3 g/L(4.5±1.9)compared with that in group B before surgery,and group C decreased by 2.9 g/L(2.9±1.2)in average,which was significantly different(P<0.05)from group A 10.2 g/L(10.2±1.8).There was no statistically significant difference between group A and group D(P>0.05).And the other indexes were not significantly different between the two groups.Conclusion:This study found that different infusion solutions with different crystal-colloid ratios had an effect on perioperative colloid osmotic pressure and level of albumin.

Morphological and histological changes in the brains of turbot(Scophthalmus maximus)with gonadal development

The brain plays a critical role in controlling reproduction through the hypothalamus-pituitary-gonadal(HPG)axis in vertebrates.Turbot(Scophthalmus maximus)has become an economically important marine fish in Europe and North China.Previous research investigating turbot reproduction has focused on the role of the HPG axis in regulating egg and sperm production.However,the morphology and histology of the organs in the HPG axis have not been studied.In this study,we investigated the morphology and histology of brains in female and male turbot at different stages of gonadal development.The results showed that the brains of both female and male turbot were composed of seven parts that are typical of advanced teleosts:the telencephalon,diencephalon,cerebellum,hypothalamus,pituitary gland,myelencephalon,and olfactory bulbs.The telencephalon was well-developed and contained five distinct lobes,with the contiguous diencephalon at the caudal portion.The torus longitudinales and rostral torus semicircularis of the mesencephalon flattened along the dorsal surface,and the rostral corpus cerebellum was located in the dorsal portion.The actual total brain volume in mature males was significantly greater(p<0.05)than that of females with gonadal development.Notably,the pituitary volume in male turbot significantly increased(p<0.05)from immature to mature stage,but this difference did not occur in females.The data together illustrate a distinct sex difference in the turbot brain during gonadal development,providing insight into their HPG axes.

Ecophysiological responses to drought stress in Populus euphratica

Ecophysiological responses to drought stress of Populus euphratica in Alashan Desert Eco-hydrology Experimental Research Station were investigated.Results show that under mild and moderate drought stress,stomatal length,aperture,area and density is likely to decrease in the early days,but afterwards this is likely to recovery with treatment over the pas‐sage of treatment time.Under severe drought stress,these properties appear to decline continuously.However,after 45 days of drought-stress treatment,the decline is not as noticeable as before,indicating that Populus euphratica could possibly reduce water evaporation by shutting down the stoma,leading to an improvement in its water use efficiency with better survival under drought stress conditions.The leaf area first decreases,and then increases under mild and moderate drought stress conditions,with the average values under different degree of stress found to be approximately 129.52,120.08,116.63 and 107.28 cm2,respectively.Under moderate stress conditions,the leaf water potential appears to show a continuous decline where the average values under different degree of stress are found to be-1.27,-1.85,-4.29 and-4.80 MPa,respectively.In terms of proline content,the results demonstrate that this factor appears to increase significant‐ly under moderate and severe drought stress conditions.Especially under severe drought stress condition,the content is found to be more than 700μg/g.Ranging over average values of 14.64 and 15.90 nmol/g under moderate and severe drought stress,respectively,Malondialdehyde content is found to increase quite rapidly under moderate and severe drought stress conditions at first,which then appears to decrease gradually with the treatment over time.

Effect of Soil on the Growth and Quality of Pepper during Different Durations of Continuous Planting

With the greenhouse soil that had been planted with cucumber as the control,the greenhouse soil that had been planted with pepper for 3,7,10 and 15 consecutive years was collected,and the effects of continuous cropping on plant height,stem diameter,leaf area,yield,photosynthetic pigment content and fruit quality of pepper were investigated by pot experiment. The results showed that with the extension of continuous cropping duration,the plant height,stem diameter and yield of pepper decreased significantly compared with the control; and the mass fraction of photosynthetic pigments declined,and the mass fractions of chlorophyll a and total chlorophyll were significantly lower than those of the control. Under the condition of continuous cropping,the fruit quality of pepper decreased significantly,and the mass fractions of soluble solids and soluble protein were significantly lower than those of the control.

Clinical Study on the Effects of Different Positions on Supine Hypotensive Syndrome in Cesarean Section after Lumbar Anesthesia

Objective:To explore the effects of different positions on supine hypotensive syndrome in cesarean section after lumbar anesthesia.Methods:600 fullterm parturient were randomly divided into 4 groups.The patented positioning pads(patent number:ZL 201720618886.5)in our department was used when the left-leaning position was placed.The parturient lied in a supine position for anesthesia,and then the group of positioning pads was placed after turning into the lateral position.The parturient were divided into group A(supine position),group B(left-leaning to 10°),group C(left-leaning to 20°),and group D(30°).Observation index:Main index:Comparison of maternal blood pressure changes and neonatal blood gas analysis in the supine position without using position pad and with the use of patent positioning pads in different tilt angles(10°,20°,30°).Minor index:1)the use and frequency of vasoactive drugs,whether a left-leaning operating bed or uterine displacement is required;2)the selffeeling of the parturient;3)newborn’s Apgar scores of 1 minute,5 minutes,and 10 minutes after birth;4)whether the obstetrician can perform the operation smoothly in the corresponding left leaning position.Results:The blood pressure at the supine position after anesthesia,the beginning of surgery and the time when the newborn was delivered in group A and group B were significantly different from those in group C(P<0.05).There were significant differences at different timings in group A and group B,and the decline was more significant at the supine position after anesthesia,the beginning of surgery and the time when the newborn was delivered(P<0.05).The pH of blood gas of newborns in group A,group B and group C was between 7.25 and 7.37,and there was no significant difference among the three groups(P>0.05).Conclusion:The use of positioning pads can prevent the adverse effects of supine hypotensive syndrome on parturient and newborns to a certain extent.

通过虫体花粉识别构建植物-传粉者网络:人工模型与AI模型高度一致

传粉是生态系统中一项关键服务,准确识别和分析传粉者携带的花粉对于理解植物‒传粉者交互作用以及传粉服务至关重要。传统的花粉识别方法依赖于显微镜下的人工直接观察,这种方法耗时且需要专业知识,限制了其在大规模应用中的效率,在评估传粉效率和稀有植物‒传粉者连接方面存在局限性。针对此问题,我们使用公共平台训练了基于河南洛阳市天池山国家森林公园14种同时开花植物的花粉识别人工智能(AI)模型,通过比较人工显微镜观察和AI模型识别142只传粉者身体携带的花粉构成,首次探讨了两种方法构建的植物‒传粉者互作网络的结构差异。结果表明AI模型在构建时能够达到96%的整体准确率。人工识别与AI模型在识别的连接数量、花粉数量以及图片一致率方面存在差异。AI模型在识别连接和花粉数量上略高于人工方法,并且在第三方的一致性检验中,超过半数的情况倾向于AI模型的结果。尽管存在一些独有连接的差异,人工识别与AI模型构建的定量网络在结构特征上展现出高度的相似性。本研究揭示了AI图像识别技术对提高花粉分析效率和准确性的作用,以及应用于植物‒传粉者互作研究的潜力,这将有助于传粉网络研究的大规模开展,为传粉生态学研究提供新的工具和视角。

Percutaneous Penetration and Dermal Exposure Risk Assessment of UV Absorbents in Sunscreens and Isolation Cosmetics

Ultraviolet absorbents(UVs)make up a group of industrial chemicals that is used in various consumer products and industrial applications.Due to their extensive production and usage,UVs have been detected in multiple environmental matrixes.Recently,UVs have garnered significant attention because of their probable adverse impacts on human health and the environment.This study examines UVs levels in sunscreens and isolation cosmetics and further assesses human exposure to UVs through the application of cosmetics.The total concentrations of nine UVs in 87 sunscreen and isolation cosmetic products ranged from 75.5 to 4.25×10^(4) ng/g.Among them,2-(2-hydroxy-5-methyl-phenyl)benzotriazole(UV-P)and 2-hydroxy-4-(octoxy)benzophenone(UV-531)had the highest concentrations.Use of the EpiSkin model indicated rapid absorption and strong dermal penetration by UV-328 following 36 h of exposure with a cumulative absorption rate of 41.8%±2.82%.Other congeners are expected to be distributed in the dermal tissue and donor fluid.Furthermore,this study explored potential mechanisms implicating skin biochemical barriers in the metabolism and transport of UVs.The potential of UVs to act as substrates and inhibitors of P450 enzymes was assessed,and their metabolites were predicted.Molecular docking simulations demonstrated that UVs can significantly interact and bind with three transport proteins in skin:MDR1,OATP2B1,and OATP3A1.Daily UVs exposure through the skin was assessed,revealing that dermal absorption levels of UV-P in sunscreen sprays(4.66×10^(3) ng/(kg bw day))and sunscreens(6.01×10^(3) ng/(kg bw day))were close to or exceeded the reference dose(RfD)and therefore require more attention.

全氟及多氟烷基类化合物毒性评估的新策略与新方法

World Health Organization has estimated that annually 24.3%(13.7 million of 56.1 million)of all global premature deaths and28.1%(1.57 million of 5.60 million)deaths among children under five,are linked to environmental factors[1].

A Large Acute Gastroenteritis Outbreak Associated with Both Campylobacter coli and Human Sapovirus—Beijing Municipality,China,2021

What is already known about this topic?Campylobacter is a significant foodborne pathogen that leads to global outbreaks of acute gastroenteritis(AGE)usually affecting less than 30 individuals.Human sapovirus(HuSaV)is an enteric virus responsible for sporadic cases and outbreaks of AGE worldwide.In a study conducted in Beijing,HuSaV detection ranked second after norovirus.What is added by this report?We present a discussion of the first large-scale outbreak of AGE caused by both Campylobacter coli(C.coli)and HuSaV.The outbreak involved a total of 996 patients and exhibited two distinct peaks over a period of 17 days.Through case-control studies,we identified exposure to raw water from a secondary water supply system as a significant risk factor.Among 83 patients,49 samples tested positive for C.coli,39 samples tested positive for HuSaV,and 27 samples tested positive for both pathogens using real-time polymerase chain reaction detection.Furthermore,whole-genome sequencing of 17 C.coli isolates obtained from 17 patients revealed that all isolates belonged to a highly clonal strain of C.coli.What are the implications for public health practice?Outbreaks of AGE resulting from multiple pathogen infections warrant increased attention.This report emphasizes the significance of ensuring the safety of drinking water,particularly in secondary supply systems.

Printable SnO2 cathode interlayer with up to 500 nm thickness-tolerance for high-performance and large-area organic solar cells

The printable electrode interlayer with excellent thickness tolerance is crucial for mass production of organic solar cells(OSCs)by solution-based print techniques. Herein, high-quality printable SnO2 films are simply fabricated by spin-coating or bladecoating the chemical precipitated SnO2 colloid precursor with post thermal annealing treatment. The SnO2 films possess outstanding optical and electrical properties, especially extreme thickness-insensitivity. The interfacial electron trap density of SnO2 cathode interlayers(CILs) are very low and show negligible increase as the thicknesses increase from 10 to 160 nm,resulting in slight change of the power conversion efficiencies(PCEs) of the PM6:Y6 based OSCs from 16.10% to 13.07%. For blade-coated SnO2 CIL, the PCE remains high up to 12.08% even the thickness of SnO2 CIL is high up to 530 nm. More strikingly, the large-area OSCs of 100 mm2 with printed SnO2 CILs obtain a high efficiency of 12.74%. To the best of our knowledge, this work presents the first example for the high-performance and large-area OSCs with the thickness-insensitive SnO2 CIL.

Evaluation of the physiochemical and metabolite of different region coffee beans by using UHPLC-QE-MS untargeted-metabonomics approaches

Coffee is one of the most important agricultural commodities and has the unique organoleptic characteristics such as strong but not bitter taste,fragrant,oily,and fruity.In this study,an untargeted metabolomics approach based on UHPLC-QE-MS was used to investigate the differences in terms of components of precursor metabolites in coffee beans from 18 producing regions worldwide.Fingerprint analysis,principal component analysis and hierarchical clustering analysis revealed a neat separation among coffee beans.Compounds with high relevance to variance in the projection values in supervised multivariate analysis were selected as important metabolites for the discrimination of coffee samples.In total,10 different families of compounds were considered as potential markers of the coffee beans:3-hydroxycoumarin,4,5-di-O-caffeoylquinic,cryptochlorogenic acid,palmitic amide,linoleamide,arachidic acid,petroselinic acid,trehalose,L-glutamic acid,L-malic acid.The findings presented herein serve as a suitable framework for the design of novel discrimination strategies in food origin tracing.

The thermal transformation mechanism of chlorinated paraffins:An experimental and density functional theory study

The increasing production and usage of chlorinated paraffins(CPs) correspondently increase the amount of CPs that experience thermal processes. Our previous study revealed that a significant amount of medium-chain chlorinated paraffins(MCCPs), short-chain chlorinated paraffins(SCCPs) as well as aromatic and chlorinated polycyclic aromatic hydrocarbons(Cl-PAHs) were formed synergistically during the thermal decomposition of CP-52(a class of CP products).However, the transformation mechanisms of CP-52 to these compounds are still not very clear.This article presents a mechanistic analysis on the decomposition of CP-52 experimentally and theoretically. It was found that CP-52 initially undergoes dehydrochlorination and carbon chain cleavage and it transformed into chlorinated and unsaturated hydrocarbons. Cyclization and aromatization were the most accessible pathways at low temperatures(200–400°C), both of which produce mostly aromatic hydrocarbons. As the temperature exceeds 400°C, the hydrocarbons could decompose into small molecules, and the subsequent radical-induced reactions become the predominant pathways, leading to the formation of Cl-PAHs. The decomposition of CP-52 was investigated by using density functional theory and calculations demonstrating the feasibility and rationality of PCB and PCN formation from chlorobenzene. The results improve the understanding of the transformation processes from CP-52 to SCCPs and Cl-PAHs as well as provide data for reducing their emissions during thermal-related processes.