现代仪器分析课程思政教学案例设计

现代仪器分析是食品、制药相关专业的重要基础课,在仪器的发展和应用教学环节,有很多课程思政元素可以与专业知识结合。本文以创新精神、人文素养、爱国主义等为思政元素,主要以发生在身边的人和事为基础,进行了思政教学案例的设计,为其他相关课程思政元素的挖掘提供了有价值的参考和借鉴。

Maternal and burial environment determine the physical dormancy release in tropical Senna auriculata(Fabaceae) seeds

In tropical ecosystems,species with an impermeable seed coat,i.e.physical dormancy(PY),are large in number and their seed coat is considered to be an adaptive trait for species persistence and colonization.However,only little is known about their mechanisms for breaking dormancy.The objective of this study was to understand the importance of seed maturation site and burial location in determining the PY release of Senna auriculata.Freshly collected seeds of S.auriculata from Vellore and Coimbatore,Tamil Nadu,India,germinated to 11±1.5%and19±2.5%respectively and remaining seeds did not imbibe water,thus had PY.Germination of seeds from both sites following hot-water treatment for 30 s and mechanical scarification increased significantly and seeds were able to germinate at a wide-range of temperatures(5–35℃)both in light and darkness.When incubated at 15/60℃for 3 months,dormancy release for seeds collected from Coimbatore(72%)was greater than seeds matured in Vellore(53%).Following 1 year of burial at three different locations,seeds from Coimbatore germinated to higher percentage than Vellore seeds at all locations.In particular,the higher temperature sites released dormancy to greater extent than the lower temperature site.Our results suggest that summer temperatures(>60℃)prevailing in the tropics provide appropriate cues for breaking PY,but this could be greatly affected by the initial state of seeds and the burial environment.

The association between sarcopenia and cirrhosis: a Mendelian randomization analysis

We read with great interest the study by Kuchay et al.(1)which showed sarcopenia was very common in patients with cirrhosis and could have a significant impact on their survival.Kim et al.(2)indicated that the presence of sarcopenia was associated with poor prognosis and the development of complications from cirrhosis and could be used for risk assessment.It is difficult to infer causal effects only from observational studies because of confounding.Here,we attempted to answer whether the associations of sarcopenia-related phenotypes with cirrhosis were causal or not by using the Mendelian randomization(MR)design.

张大千青城艺缘(上)

张大千先生的青城艺缘所涉,今人多因爱之切而传误多。其青城艺缘之初始,距今已时隔数十年;又因其艺术生涯的博大而牵引繁杂,并逢世变多故而南北辗转等缘故,各家之说,往往述见不一。但根据张大千信札、画作款识的内证以及报刊、亲友的相关记述,可对张大千先生的“青城艺缘”的缘起、到青城的时间以及卜居青城的相关活动,作出较为清晰的初步判断。

Suppression of PFKFB3-driven glycolysis restrains endothelial-to-mesenchymal transition and fibrotic response

Endothelial-to-mesenchymal transition(EndoMT),the process wherein endothelial cells lose endothelial identity and adopt mesenchymal-like phenotypes,constitutes a critical contributor to cardiac fibrosis.The phenotypic plasticity of endothelial cells can be intricately shaped by alteration of metabolic pathways,but how endothelial cells adjust cellular metabolism to drive EndoMT is incompletely understood.Here,we identified 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3(PFKFB3)as a critical driver of EndoMT via triggering abnormal glycolysis and compromising mitochondrial respiration.Pharmacological suppression of PFKFB3 with salvianolic acid C(SAC),a phenolic compound derived from Salvia miltiorrhiza,attenuates EndoMT and fibrotic response.PFKFB3-haplodeficiency recapitulates the anti-EndoMT effect of SAC while PFKFB3-overexpression augments the magnitude of EndoMT and exacerbates cardiac fibrosis.Mechanistically,PFKFB3-driven glycolysis compromises cytoplasmic nicotinamide adenine dinucleotide phosphate(reduced form,NADPH)production via hijacking glucose flux from pentose phosphate pathway.Efflux of mitochondrial NADPH through isocitrate/α-ketoglutarate shuttle replenishes cytoplasmic NADPH pool but meanwhile impairs mitochondrial respiration by hampering mitochondrial iron-sulfur cluster biosynthesis.SAC disrupts PFKFB3 stability by accelerating its degradation and thus maintains metabolic homeostasis in endothelial cells,underlying its anti-EndoMT effects.These findings for the first time identify the critical role of PFKFB3 in triggering EndoMT by driving abnormal glycolysis in endothelial cells,and also highlight the therapeutic potential for pharmacological intervention of PFKFB3(with SAC or other PFKFB3 inhibitors)to combat EndoMT-associated fibrotic responses via metabolic regulation.

A 50-year sedimentary record of heavy metals and their chemical speciations in the Shuangtaizi River estuary(China):implications for pollution and biodegradation

Two parallel sediment cores collected from tidal flat located in the Shuangtaizi River estuary were analyzed for heavy metal concentrations and chemical speciations.Based on the ^(137)Cs activity profile,mean sedimentation rate at the sampling site during the past 50 years was estimated to be 1.3 cm·a^(-1).Correlation analyses show that almost all the metals are associated with each other,suggesting that these metals might be derived from same sources and/or affected by same geochemical processes.Influence of total organic carbon(TOC)content on the concentrations of Cr,Ni,Cu and Cd is evident.Silt and clay contents,instead of sand content,play an important role in the distribution of these metals.The dominant binding phases for most of the metals(except for Cd)are the residual.The relative decrease of the residual fraction of Cd and Pb in the upper 66 cm of the core is striking.The distribution of chemical fraction confirms that the residual fractions of these metals have a natural origin,while only the non-residual fractions of Cd and Pb increased upward the core due to pollution in the past five decades.Pollution assessment on these heavy metals based on Index of Geoaccumulation(I_(geo))also demonstrates that most of the metals are unpolluted.The weak pollution as observed in the sediments is perhaps related to a local plant,the Suaeda heteroptera Kitag,which may have played a significant role in the biodegradation of these metals and the metal distribution in the estuary.

Sand-mediated ice seeding enables serum-free low-cryoprotectant cryopreservation of human induced pluripotent stem cells

Human induced pluripotent stem cells(hiPSCs)possess tremendous potential for tissue regeneration and banking hiPSCs by cryopreservation for their ready availability is crucial to their widespread use.However,contemporary methods for hiPSC cryopreservation are associated with both limited cell survival and high concentration of toxic cryoprotectants and/or serum.The latter may cause spontaneous differentiation and/or introduce xenogeneic factors,which may compromise the quality of hiPSCs.Here,sand from nature is discovered to be capable of seeding ice above10◦C,which enables cryopreservation of hiPSCs with no serum,much-reduced cryoprotectant,and high cell survival.Furthermore,the cryopreserved hiPSCs retain high pluripotency and functions judged by their pluripotency marker expression,cell cycle analysis,and capability of differentiation into the three germ layers.This unique sand-mediated cryopreservation method may greatly facilitate the convenient and ready availability of high-quality hiPSCs and probably many other types of cells/tissues for the emerging cell-based translational medicine.

An enhanced environmental multimedia modeling system based on fuzzy-set approach： II. Model validation and application

Part I of this study develops an enhanced environmental multimedia modeling system （EMMS） based on fuzzy-set approach. Once the model development is complete, the composite module and the entire modeling system need to be tested and validated to ensure that the model can simulate natural phenomena with reasonable and reliable accuracy. The developed EMMS is first tested in a complete case study. And then verification results are conducted to compare with extensively researched litera- ture data. In the third step, the data from an experimental landfill site is used for a pilot-scale validation. The comparisons between EMMS outputs and the literature data indicate that the EMMS can perform accurate modeling simulation. The modules of EMMS could support the entire environmental multimedia modeling system. Further field-scale validation is finished. The results are satisfactory. Most of the modeling yields closely match the monitoring data collected from sites. In addition, with the aid of fuzzy-set approach, EMMS can be a reliable and powerful tool to address the complex environmental multimedia pollution problems and provide an extensive support for decision makers in managing the contaminated environmental systems.

An enhanced environmental multimedia modeling system based on fuzzy-set approach： I. Theoretical framework and model development

Multimedia environmental modeling is extremely complex due to the intricacy of the systems with the consideration of many related factors. Traditional environmental multimedia models （EMMs） are usually based on one-dimensional and first-order assumptions, which may cause numerical errors in the simulation results. In this study, a new user-friendly fuzzy-set enhanced environmental multimedia modeling system （FEEMMS） is developed, and includes four key modules： an air dispersion module, a polluting source module, an unsaturated zone module, and a groundwater module. Many improvements over previous EMMs have been achieved through dynamically quantifying the intermedia mass flux; incorporating fuzzy-set approach into environmental multimedia modeling system （EMMS）; and designing a user-friendly graphic user interface （GUI）. The developed FEEMMS can be a useful tool in estimating the timevarying and spatial-varying chemical concentrations in air, soil, and groundwater; characterizing the potential risk to human health presented by contaminants released from a contaminated site; and quantifying the uncertainties associated with modeling systems and subsequently providing robustness and flexibility for the remediationrelated decision making.

Optical non-destructive techniques for small berry fruits: A review

Small berries including strawberry and blueberry are extensively consumed fruits with great economic values due to their characteristic flavor and appearance as well as potential health benefits.This review elaborated the optical non-destructive techniques viz.Vis-NIR spectroscopy,computer vision system,hyperspectral imaging,multispectral imaging,laser-induced method and thermal imaging,and their applications for quality and safety control of small berry fruits.The discussion regarding the photoacoustic technique,X-ray technique,Terahertz spectroscopy,odor imaging,micro-destructive testing and smart mobile terminal-based analyzer was also presented.Furthermore,we proposed our personal understanding of the technical challenges and further trends for these optical non-destructive techniques:1)owing to the relatively low detection limit,the so-called micro-destructive techniques may be alternative to the traditional non-destructive techniques in both practical and fundamental research;2)we suggest that the research articles like“collecting data first,and then modeling the relevant properties of agricultural products by machine learning”should be less produced in related fields.That's because such research methods are likely to be suspected of“cheating”.It is recommended that some modeling competitions can be carried out in the agricultural engineering field to avoid or reduce the“cheating”model.