Effect of Tremella fuciformis polysaccharide on the stalling and flavor of tteok during storage

The effect of Tremella fuciformis polysaccharide(TFP)on the retrogradation property and aroma profile changes of tteok during storage was investigated.Results indicated that addition of TFP significantly increased the stability to thermal and mechanical shearing of starch,decreased short-term retrogradation,the hardness and the retrogradation enthalpy(ΔH)of tteok during storage,but had no significant effect on the amylopectin chain length of tteok.The possible mechanism for the retarding staling effect of TFP is related to the interaction between TFP and starch chains that interferes with the alignment of starch chains.Electronic nose and g as chromatography-mass spectrum(GC-MS)analysis results showed that the difference in the concentrations of volatile compounds and fatty acids of tteoks at different storage time gradually increased with the advancement of storage period.The addition of TFP to tteok inhibited the development of unpleasant volatile compounds,probably by delaying the oxidation and decomposition of lipids and preserving the antioxidant phenolic compounds in tteok,thus slowing down the flavor deterioration of tteok and contributing to flavor maintainace.Overall,this study could help food manufacturers to choose a high-effective and natural polysaccharide to control the retrogradation rate and flavor loss of tteok.

Healthy function and high valued utilization of edible fungi

Edible fungi are large fungi with high added value that can be utilized as resources.They are rich in high-quality protein,carbohydrate,various vitamins,mineral elements and other nutrients,and are characterized by high protein,low sugar,low fat and low cholesterol.In addition,edible fungi contain a variety of bioactive substances,such as polysaccharides,dietary fiber,steroids,polyphenols,and most of these compounds have antioxidant,anti-tumor and other physiological functions.This review comprehensively discusses the bioactive components and functional characteristics of edible fungi(such as antioxidant,anti-aging,hypolipidemic activities,etc.).Then the recent developments and prospect in the high-valued utilization of edible fungi are discussed and summarized.The objective of this review is to improve the understanding of health-promoting properties of edible fungi,and provide reference for the industrial production of edible fungi-based health products.

Spatial distribution of charcoal in topsoil and its potential determinants on the Tibetan Plateau

As an important proxy for investigating past fire activities,charcoal is often used to explore the characteristics of fire distribution and its relationships with vegetation,climate,and human activities.Research into the spatial distribution and environmental determinants for charcoal,however,is still limited.In this study,we identified and counted charcoal from topsoil samples covering the Tibetan Plateau using the pollen methodology,and investigated its relationships with vegetation net primary production(NPP),elevation,climate(precipitation,mean temperature of the coldest month and warmest month)and human population by boosted regression trees(BRT).Results reveal that the concentration of microscopic charcoal,macroscopic charcoal,and total charcoal all increase from south-west to north-east,which is consistent with the trend that the population density on the Tibetan Plateau is high in the east and low in the west,suggesting that an increase in human activity is likely to promote the occurrence of fire.The BRT modeling reveals that NPP,elevation,and mean temperature of the coldest month are important factors for total charcoal concentration on the Tibetan Plateau,and the frequency and intensity of fires further increase with increasing vegetation biomass,decreasing elevation,and decreasing mean temperature of the coldest month.The spatial variation characteristics of charcoal from topsoil on the Tibetan Plateau not only reflect well the spatial fire situation in the region,but also have a good indicative significance for vegetation,climate,and human activities.

Vegetation stability during the last two centuries on the western Tibetan Plateau:a palynological evidence

Investigating the dynamics of vegetation is an essential basis to know how to protect ecological environments and to help predict any changes in trend.Because of its fragile alpine ecosystem,the Tibetan Plateau is a particularly suitable area for studying vegetation changes and their driving factors.In this study,we present a high-resolution pollen record covering the last two centuries extracted from Gongzhu Co on the western Tibetan Plateau.Alpine steppe is the predominant vegetation type in the surrounding area throughout the past 250 years with stable vegetation composition and abundance,as revealed by pollen spectra dominated by Artemisia,Ranunculaceae,Cyperaceae,and Poaceae.Detrended canonical correspondence analysis(DCCA)of the pollen data reveals low turnover in compositional species(0.41 SD),suggesting that the vegetation in the Gongzhu catchment had no significant temporal change,despite climate change and population increases in recent decades.We additionally ran DCCA on ten other pollen records from the Tibetan Plateau with high temporal resolution(1-20 years)covering recent centuries,and the results also show that compositional species turnover(0.15-0.81 SD)is relatively low,suggesting that the vegetation stability may have prevailed across the Tibetan Plateau during recent centuries.More high-resolution pollen records and high taxonomic-resolution palaeo-vegetation records(such as sedaDNA),however,are needed to confirm the vegetation stability on the Tibetan Plateau.

Endovascular treatment for basilar artery occlusion:a meta-analysis

Acute basilar artery occlusion(BAO)may lead to severe disability or death in about 70%of patients.12 Previous studies have estab-lished endovascular treatment(EVT)as the standard treatment for patients with acute anterior circulation occlusions.3-9 However,the ideal effective treatment for acute BAO remains controversial.

Pressure shear assisted extraction of polysaccharide from Auricularia auricula and its biological activities

In this paper,using to the comprehensive scoring method,pressure shear assisted extraction was used to prepare polysaccharide from Auricularia auricula(PS-AAP)by orthogonal test to optimize the extraction.The highest comprehensive score(90.70)was obtained under 1:70 g/mL solid-liquid ratio,110°C reaction temperature,60 min reaction time and 1.0 MPa reaction pressure.Compared to AAP by water bath(WB-AAP),PS-AAP led to a higher extraction efficiency and decreased the relative molecular weight.In addition,infrared spectrum(FT-IR)analysis showed that pressure shear assisted did not change the polysaccharide structure.Scanning electron microscope(SEM)showed that PS-AAP was smaller and more broken by pressure shear assisted.Furthermore,the ratio of glucose to mannose in PS-AAP was relatively higher than WB-AAP,which also proved that PS-AAP had certain antioxidant and hypoglycemic activities.Compared with WB-AAP,the inhibitionα-glucosidase andα-amylase activity of PS-AAP increased by 11.37%and 24.43%respectively.These results revealed that PS-AAP has the poten-tial value of being a antioxidant and hypoglycemic agent.

基于前景与透明度联合求解的多层次仿射类抠像与合成方法

数字图像抠像与合成问题是虚拟现实中的经典问题.抠像问题需要根据抠像公式,从输入图像准确地提取出前景物体的透明度(α)和前景物体的颜色值,而合成问题仅使用抠像结果与新背景图像进行结合,使其成为新的合成图像.然而,目前很多抠像算法仅局限于抠像部分的α值的计算,忽略了用于后续合成步骤的前景颜色的计算.这实际上仅限于理论研究,脱离了抠像问题的合成应用层面.同时,其他一些兼顾计算前景颜色算法的效果仍然不理想,而且也仍然缺乏合成图像数据集和对合成图像的比较.本文充分利用仿射类方法中搜索范围灵活可变的优势,采用实体像素与混合像素进行分级处理的3层次结构,联合求解出最终的α值和前景颜色.其中,每个层次均利用前向层次的先验,结合仿射类方法的像素相关性以及颜色拟合性约束,采用闭合形式进行求解.在实验中,本文不仅针对α层面进行比较,而且在数字抠像领域中首次引入针对合成图像层面的比较.在合成层面中,本文针对输入图像及各型号的三分模板(Trimap),均引入了白色背景和相应的自然图像背景.同时各方法的真实的α值和前景颜色不仅与这些背景进行了常规合成,而且也进行了一种单纯α层面的合成.实验结果表明,在数值评价结果和视觉效果方面,本文方法的最终α结果与上述各种合成效果均优于目前已有的抠像与合成方法及一些新生成的方法.

Decontamination of Cr(VI) facilitated formation of persistent free radicals on rice husk derived biochar

This study investigated the facilitation of Cr(VI)decontamination to the formation of persistent free radicals(PFRs)on rice husk derived biochar.It was found that Cr(VI)remediation by biochar facilitated the production of PFRs,which increased with the concentration of treated Cr(VI).However,excessive Cr(VI)would induce their decay.Biochar with high pyrolysis temperature possessed great performance to Cr(VI)removal,which was mainly originated from its reduction by biochar from Inductively Coupled Plasma Optical Emission Spectroscopy and X-ray Photoelectron Spectroscopy.And the corresponding generation of PFRs on biochar was primarily ascribed to the oxidization of phenolic hydroxyl groups by Cr(VI)from Fourier Transform Infrared Spectroscopy analysis,which was further verified by the H2O2 treatment experiments.The findings of this study will help to illustrate the transformation of reactive functional groups on biochar and provide a new insight into the role of biochar in environmental remediation.

Optical resonance in inhomogeneous parity-time symmetric systems

We show that inhomogeneous waveguides of slowly varied parity-time(PT) symmetry support localized optical resonances.The resonance is closely related to the formation of exceptional points separating exact and broken PT phases.Salient features of this kind of non-Hermitian resonance, including the formation of half-vortex flux and the discrete nature,are discussed.This investigation highlights the unprecedented uniqueness of field dynamics in non-Hermitian systems with many potential adaptive applications.

Microfluidic Device： A Miniaturized Platform for Chemical Reactions

Microfluidic devices, as a new miniaturized platform stemming from the field of micro-electromechanical sys-tems, have been used in many disciplines. In the field of chemical reactions, microfluidic device-based microreac-tors have shown great promise in building new chemical technologies and processes with increased speed and reli- ability and reduced sample consumption and cost. This technology has also become a new and effective tool for precise, high-throughput, and automatic analysis of chemical synthesis processes. Compared with conventional chemical laboratory batch methodologies, microfluidic reactors have a number of features, such as high mixing ef- ficiency, short reaction time, high heat-transfer coefficient, small reactant volume, controllable residence time, and high surface-to-volume ratio, among others. Combined with recent advances in microfluidic devices for chemical reactions, this review aims to give an overview of the features and applications of microfluidic devices in the field of chemical synthesis. It also aims to stimulate the development of microfluidic device applications in the field of chemical reactions.

Review on plant-derived bioactive peptides:biological activities,mechanism of action and utilizations in food development

Plant proteins are good alternative to animal sources in bioactive peptide production due to their safety,low-cost,rich resources and easy for large scale production.The bioactivities of the peptides derived from plant proteins including antihypertensive,hypocholesterolemic,immunomodulatory,antioxidant,antimicrobial,anti-diabetic,opiate and hepatoprotective effect are being increasingly recognized with regards to health promoting and disease prevention.In addition to bioactivities,the plant-derived bioactive peptides possess various functional properties including emulsifying and foaming properties,and water and oil retention capacities owning to the hydrophilic/lipophilic property,conformational flexibility and chain length of peptides.Hence,the plant-derived bioactive peptides are promising ingredients for the development of health-care and functional products.This review provides the research progress on the biological activities and functional properties of plant derived peptides.The mechanism of action and structure-activity relationships of the bioactive peptide were also described,when known.Furthermore,recent developments,major challenges and prospect in the application of the plant-derive bioactive peptides in the development of functional products are discussed and summarized.The objective of this review is to improve the understanding of plant-derive bioactive peptides,and provide some constructive inspirations for further research and industrial application in the food and medicine industry.

Effects of Hericium erinaceus polypeptide on lowering blood lipids of mice with hyperlipidemia induced by a high-fat diet

Hericium erinaceus polypeptide(HEP)was prepared by an ultrasound-microwave assisted enzymatic method.Using an ultrafiltration membrane with molecular weights of 5 and 10 kDa,HEP was fractionated into three fractions,namely,(HEP-I(<5 kDa),HEP-II(5–10 kDa),and HEP-III(>10 kDa)).In vitro chemical methods were used to compare the antioxidant and hypolipidemic abilities of the polypeptide fractions from H.erinaceus before and after simulated gastrointestinal digestion.By constructing a hyperlipidemia model,the hypolipidemic ability of the high active fraction(HEP-II)was verified.The results showed that the antioxidant and hypolipidemic abilities of the polypeptide fractions from H.erinaceus did not change dramatically during simulated gastrointestinal digestion in vitro.The polypeptide fractions from H.erinaceus exhibited high tolerance to simulated gastrointestinal digestion in vitro,with strong antioxidant and hypolipidemic activities.HEP-II with a molecular weight of 5–10 kDa had the best stability,antioxidant,and hypolipidemic abilities in gastrointestinal digestion.The secondary structure of HEP-II was mainly composed of random coil(18.36%)andα-helix(47.71%)structures,which was beneficial to the hypolipidemic ability of HEP-II.Animal experiments showed that compared to the high-fat model group,HEP-II could inhibit the weight gain of the mice,decrease the liver index and serum levels of the serum total cholesterol(TC),triglycerides(TG),low-density lipoprotein cholesterol(LDL-C),nitric oxide synthase(NOS),alanine aminotransferase(AST),and glutamic-pyruvic transaminase(ALT),increase the levels of glutathione peroxidase(GSH-Px)and high-density lipoprotein cholesterol(HDL-C),decrease the arteriosclerosis index(AI),and improve the hemorheological indices of the mice.In addition,the whole blood and plasma viscosities of the mice decreased,and HEP-II increased the level of superoxide dismutase(SOD)in the liver,reducing the level of malondialdehyde(MDA),and the degree of oxidative stress in the liver of hypolipidemia mice.Furthermore,HEP-II improved liver steatosis.These results indicated that the polypeptide fractions from H.erinaceus all had a potential hypolipidemic effect,and HEP-II had the strongest potential hypolipidemic effect.

Advances in magnetic resonance imaging contrast agents for glioblastoma-targeting theranostics

Glioblastoma(GBM)is the most aggressive malignant brain tumour,with a median survival of 3 months without treatment and 15 months with treatment.Early GBM diagnosis can significantly improve patient survival due to early treatment and management procedures.Magnetic resonance imaging(MRI)using contrast agents is the preferred method for the preoperative detection of GBM tumours.However,commercially available clinical contrast agents do not accurately distinguish between GBM,surrounding normal tissue and other cancer types due to their limited ability to cross the blood-brain barrier,their low relaxivity and their potential toxicity.New GBM-specific contrast agents are urgently needed to overcome the limitations of current contrast agents.Recent advances in nanotechnology have produced alternative GBM-targeting contrast agents.The surfaces of nanoparticles(NPs)can be modified with multimodal contrast imaging agents and ligands that can specifically enhance the accumulation of NPs at GBM sites.Using advanced imaging technology,multimodal NP-based contrast agents have been used to obtain accurate GBM diagnoses in addition to an increased amount of clinical diagnostic information.NPs can also serve as drug delivery systems for GBM treatments.This review focuses on the research progress for GBMtargeting MRI contrast agents as well as MRI-guided GBM therapy.

The value of ultrasound elastography in differential diagnosisof superficial lymph nodes

The study evaluated the value of ultrasound elastography in differentiating the benign and malignant superficial lymph nodes.A total of 112 subjects,including 82 patients with enlarged lymph nodes and 30 healthy volunteers,were recruited.All the subjects were examined by B-mode ultrasonography,power Doppler ultrasonogra-phy and elastography.Most of the patients were histo-pathologically confirmed by needle aspiration cytology and some patients were diagnosed by clinical data combined with follow-upfindings.The sensitivity,speci-ficity and accuracy of B-mode ultrasonography were 59.8%,76.5%and 67.1%,those of the bloodflow classification by power Doppler ultrasonography 77.0%,82.3%and 79.4%and those of elastographic classification 74.7%,97.1%and 84.5%,respectively.The elasticity of the lymph nodes was quantitatively measured and defined as stiffness value.When the stiffness value of 2.395 was taken as the cutoff point,the sensitivity and specificity of elastography were 78.41%and 98.51%,and the Youden index reached the highest,with the value being 0.7692.The stiffness values of two indeterminate benign lymph nodes,the elastrographicfindings of which were rated as patterns 2 and 3,were below the cutoff point.The elastographicfindings of 10 malignant lymph nodes were also classified as pattern 2 or 3.Only one of them had the stiffness values below the cutoff point.It was concluded that ultrasound elastography is a novel,noninvasive and convenient tool for the differentiation of the nature of the superficial lymph nodes in clinical practice.