Degradation and resynthesis of chlorophyll during increased oxidative stress and prolonged darkness differ between annual and perennial flax(Linum L.)

Among plants,there is considerable variation in lifespan:annuals live less than one year,whereas perennials live for several years,with the longest-living perennial having survived 43,600 years.As proposed by the Disposable Soma Theory,this lifespan variation among plants likely reflects differential investment of limited energy and nutrient resources,with perennials investing more energy and nutrients into biomolecular maintenance compared to annuals in order to ensure persistence over multiple seasons.Such differential investment may be particularly important during periods of exogenous stress,which are known to accelerate biomolecular damage.The present study evaluated this hypothesis using annual and perennial flax(Linum L.)subjected to two exogenous stressors—increased oxidative stress(i.e.,foliar H2O2spraying)and complete prolonged darkness.As chlorophyll has been shown to exhibit degradation in response to changes in environmental conditions,we utilized changes in chlorophyll levels during and after periods of exogenous stress to evaluate our hypotheses.We predicted that i)perennials would exhibit a slower rate of chlorophyll degradation during exposure to exogenous stressors compared to annuals,and ii)perennials would exhibit a faster rate of chlorophyll resynthesis following such exposure compared to annuals.Chlorophyll levels before,during,and after exposure to both exogenous stressors were measured in two separate trails,once using image colour analysis and once using spectrophotometry.While chlorophyll degradation rates in response to oxidative stress did not differ between annuals and perennials,contrary to our predictions,chlorophyll resynthesis rates following such exposure were significantly higher in perennials,as predicted.When plants were subjected to complete prolonged darkness,chlorophyll degradation rates were significantly lower in perennials than annuals,as predicted;however,when plants were subsequently reintroduced to natural photoperiod,chlorophyll resynthesis rates did not consistently differ between annuals and perennials,though they tended to be higher in the latter,as predicted.Overall,our study illuminates that evolutionary transitions between life history strategies in plants have been accompanied by physiological modifications to chlorophyll dynamics that permit perennial species to better maintain chlorophyll levels—and thus photosynthetic energy acquisition-in the face of exogenous stressors,which likely underlies their capacity to survive for multiple growing seasons.Future studies should explore whether other key biomolecules(e.g.,proteins,DNA)are also better maintained in perennial plants,especially in the face of exogenous stress.

FUNDAMENTAL PARAMETER OF THE OPTIMUM EXCITATION CONDITIONS IN THE ANALYTICAL EMISSION SPECTROSCOPY——THE DIFFERENCE IN IONIZATION POTENTIAL BETWEEN THE MATRIX AND THE ANALYSIS ELEMENTS IN THE PLASMA

Ⅰ. INTRODUCTION The de carbon arc source is one of the fundamental sources used in analytical emission spectroscopy. Though during the past two decades many other new sources have been developed, the carbon arc source, due to its simplicity, suitabitity and sensitivity, is still being commonly used in numerous fields. By using this source in the analysis

THE PRECISE AND NEW ANALYSIS FOR A MODE Ⅲ GROWING CRACK IN AN ELASTIC-PERFECTLY PLASTIC SOLID

The near crack line field analysis method has been used to investigate into Mode III quasistatically propagating crack in an elastic-perfectly plastic material. The significance of this paper is that the usual small scale yielding theory has been broken through. By obtaining the general solutions of the stresses and the displacement rate of the near crack line plastic region, and by matching the general solutions with the precise elastic fields (not the usual elastic K-dominant fields) at the elastic-plastic boundary, the precise and new solutions of the stress and deformation fields, the size of the plastic region and the unit normal vector of the elastic-plastic boundary have been obtained near the crack line. The solutions of this paper are sufficiently precise near the crack line region because the roughly qualitative assumptions of the small scale yielding theory have not been used and no other roughly qualitative assumptions have been taken, either. The analysis of this paper shows that the assumingly 'steady-state case' for stable crack growth, which has been discussed attentively in previous works, do not exist, and the plastic strains near the crack line do not have singularities, Two most important cases for stable crack growth have been discussed.

Morphology and morphometry of two hybridizing buntings at their hybrid zone in northern Iran reveal intermediate and transgressive morphotypes

The closely related Black-headed Bunting(Emberiza melanocephala,a western Palearctic lineage)and Red-headed Bunting(Emberiza bruniceps,an eastern Palearctic lineage)hybridize and replace each other south of the Caspian Sea.The parental species have distinct phenotypes and therefore morphology is useful for assessing hybridization in the contact zone.In the years of 1940 and 1977,quite a few hybrids were collected and studied morphologically.Since then,the hybrid zone appears to have expanded westwards,but there has been a time gap in the collection of morphological data.Here we reanalyze bunting specimens morphologically and compare the historical data with recent data.Morphometric and phenotypic traits from three time periods(1940,1977 and recent)were studied to assess phenotypic variation of hybrids,pattern of hybridization,and transgressive traits in the hybrid zone.Our results show that most of the birds in the hybrid zone exhibit intermediate phenotypes(both colors and morphometric characters),ranging from the pure phenotype of either of the parental species.However,hybridization has also produced novel phenotypes not seen in any of the parents.Using a canonical discriminant function analysis,the morphometric characters separated each parental species and the hybrids quite well.Our results showed morphometric intermediacy of hybrids in accordance with phenotypes.We observe a time trend in which recent hybrids are more similar to Red-headed Buntings phenotypically compared to historical samples.This pattern is likely a signature of a westward expansion of the Red-headed Bunting into the breeding range of the Black-headed Bunting.

Vibration Suppression Analysis for Supporter with Constrained Layer Damping

By analyzing the correlation between modal calculations and modal experiments of a typical supporter, an effective finite element analysis( FEA)model of the actual aerospace supporter is created. According to the analysis of constrained viscoelastic damping, the strategies of PVC have been worked out, and the correlation between modal calculations and modal experiments of the supporter has also been computed, and then, an experiment has been designed based on the calculation results. The results of experiments verify that the PVC strategy can effectively suppress vibration.

Ratio K: a New Way of Metering and Evaluating the Risk and Return of Stock Investment

Although widely used, both the Markowitz model and VAR (Value at Risk) model have some limitations in evaluating the risk and return of stock investnent.By the analysis of the conceptions of risk and return,together with the three hypotheses of technological analysis, a novelty model of metering and evaluating the risk and return of stock investnent is established.The major indicator of this model , risk-return ratio K, combines the characteristic indicators of risk and return. Regardless of the form of the risk-return probability density functions, this indicator K can always reflect the risk-return performances of the invested stocks clearly and accurately. How to use the model to make optimum investment and how to make portfolio combined with clustering analysis is also explained.

The Effect on the Electric Structure and Optical Properties of Ca2Ge Bulk with Sr-Doping

The electronic structure and the optical properties of Ca2Ge have been calculated by the first-principles pseudo potential method. The results of the electric structure show that Ca2Ge bulk is a direct semiconductor with the band gap of 0.306 eV, the conduction band is mainly composed of Ca 3d, the valence bands is mainly composed of Ge 3p. With Sr-doping, Ca2Ge bulk is a direct semiconductor with the band gap of 0.350 eV, the conduction bands are mainly composed of Ca 3d and Sr 3d, the valence bands are mainly composed of Ge 3p and Sr 3d. The results of the optical properties show that the dielectric constant of Ca2Ge bulk is reduced from 21.52 to 13.94, the reflectivity is decreased, and the absorption is increased with Sr-doping. The optical properties are improved with Sr-doping, the results offer theoretical guide for the optical properties control of Ca2Ge.

A NEWLY RECOGNIZED PRECANCEROUS LESION OF THE STOMACH (HISTOPATHOLOGIC FEATURES OF GLOBOID DYSPLASIA OF HUMAN GASTRIC EPITHELIUM)

The histopathological features of the globoid dysplasia of the human gastric epithelium were described in detail and in series by means of observation of serial sections of 61 cases with globoid dys-plasias. Three grades were divided according to the architectural and cellular atypia of the globoid dys-plasias. The penetration of outer layer globoid dys-plastic cells through the basement membrane of 'the structure of double layers' appeared in typical globoid dysplasia grade II and the infiltration of the globoid dysplastic cells into stroma as well as the formation of incipient focus of signet ring cell carcinoma were described. The twinkling scene of the infiltration of the globoid dysplastic cells into lamina propria through the basement membrane, and the destroying of the basement membrane by the globoid dysplastic cells were shown by means of Gordon Sweet's staining. Through the analysis as for the distribution characteristics of ages and sexes in 61 globoid dysplasia cases and 51 signet ring cell carcinomas, a fact was discovered that the mobility of female cases was ten years prior to that of male ones in average. A conclusion could be made that the globoid dysplasia might be an important precan-cerous lesion of the signet ring cell carcinoma of the stomach.

Inverse Perturbation Method for Inverse Eigenvalue Problem Based on Finite Element Analysis

An inverse perturbation method is described for solving the general inverse eigenvalue problem. By taking the analysis of the rotor system as example based upon FEM,the new inverse perturbation method for structural design with specified low-order natural frequencies or frequency constraint bands is detailed as well as its complete theoretical basis. Moreover, formulations to calculate the inverse perturbation parameter ε and method to select the corresponding ε's value properly are also proposed. The proposed method is characterized in reducing frequency analysis and suitable for large and small structural changes alike. Finally, several different numerical examples for inverse cigenvalue problem are discussed to illustrate the method, which show that this inverse perturbation method is general and can be applied to other type of structure or element.

Delay Analysis and Formulation Inference of Signalized Intersection for Traffic Congestion Conditions

Vehicle delay is an important measure to evaluate the signal timings of signalized intersections.When optimization the signal control parameters, delays of vehicles from all approach directions of an intersection should be considered. Based on the analysis of the vehicle delay on an approach of intersection, directed against the typical condition of a congested intersection-over-saturated condition, the paper has analyzed and inferred the intersection delay dynamic formulation, and has established the relation between intersection delay,the signal timings, vehicle arrival rate and the queue lengths, and that provides useful information for understanding vehicle delay of signalized intersection and for establishing performance index function of signal timing optimization.

Golden Ratio Sinusoidal Sequences and the Multimode Pulsation of the δ Sct Star V784 Cassiopeiae

Non periodic ordered sequences obtained by production rules in formal grammars are applied to the analysis of the multi-periodicity of the δ-Scuti type variable star V784 Cas. An artificial light curve for V784 Cas is generated by a non deterministic derivation in a context-sensitive grammar by concatenation of two sinusoidal fragments following certain word sequences. The two basic building blocks represent temporal segments in a golden ratio and the number of long and short segments in a word are also in a golden ratio.

OPTIMAL SELECTION FOR THE WEIGHTED COEFFICIENTS OF THE CONSTRAINED VARIATIONAL PROBLEMS

The aim is to put forward the optimal selecting of weights in variational problemin which the linear advection equation is used as constraint. The selection of the functionalweight coefficients ( FWC) is one of the key problems for the relevant research. It wasarbitrary and subjective to some extent presently. To overcome this difficulty, thereasonable assumptions were given for the observation field and analyzed field, variationalproblems with " weak constraints" and " strong constraints" were considered separately. Bysolving Euler' s equation with the matrix theory and the finite difference method of partialdifferential equation, the objective weight coefficients were obtained in the minimumvariance of the difference between the analyzed field and ideal field. Deduction results showthat theoretically the optimal selection indeed exists in the weighting factors of the costfunction in the means of the minimal variance between the analysis and ideal field in terms ofthe matrix theory and partial differential ( corresponding difference ) equation, if thereasonable assumption from the actual problem is valid and the differnece equation is stable.It may realize the coordination among the weight factors, numerical models and theobservational data. With its theoretical basis as well as its prospects of applications, thisobjective selecting method is probably a way towards the finding of the optimal weightingfactors in the variational problem.

Mimotope peptide modified pompon mum-like magnetic microparticles for precise recognition,capture and biotransformation analysis of rituximab in biological fluids

Due to low immobilized ligand density,limited binding capacity,and severe interference from serum proteins,developing ideal peptide-based biomaterials for precise recognition and in vivo analysis of biopharmaceuticals remains a huge challenge.In this study,mimotope peptide modified pompon mum-like biomimetic magnetic microparticles(MMPs,3.8μm)that mimic the specific functionalities of CD20 on malignant B cells were developed for the first time.Benefit from the numerous ligand binding sites(Ni^(2+))on the pompon mum-like MMPs,these novel materials achieved≥10 times higher peptide ligand densities(>2300 mg/g)and antibody binding capacities(1380 mg/g)compared to previous reported biomaterials.Leveraging the high specificity of the mimotope peptide,rituximab can be precisely recognized and enriched from cell culture media or serum samples.We also established an LC-MS/MS method using the MMPs for tracking rituximab biotransformation in patient serum.Intriguingly,deamidation of Asn55 and Asn33,as well as oxidation of Met81 and Met34 were observed at the key complementarity determining regions of rituximab,which could potentially influence antibody function and require careful monitoring.Overall,these versatile biomimetic MMPs demonstrate superior recognition and enrichment capabilities for target antibodies,offering interesting possibilities for biotransformation analysis of biopharmaceuticals in patient serum.

Unidirectional movement behavior of underwater bubbles on the wettability gradient mesh via asymmetrical bounce

The impact of underwater bubbles on solid surfaces with a gradient wettability is important for fundamental science and technological applications. Despite progress in the translational motion of underwater bubbles on asymmetric surface, a fundamental dynamic understanding of asymmetrical bounce behavior of the underwater bubble needs to be further improved.Herein, we investigate asymmetrical bounce of underwater bubbles after impacting the wettability gradient copper mesh surface.Asymmetrical bounce of the underwater bubble on the wettability gradient mesh(WGM) surface is composed by asymmetrical spread in the spread process and asymmetrical recoil in the recoil process, which induce the unidirectional movement behavior.Additionally, effective bubble-size manipulation can be easily implemented due to different volumes of bubbles remaining at different locations of WGM surface. We envision that this work will provide a new understanding of asymmetrical bounce behavior of the underwater bubble on the wettability gradient surface, and propose a novel and feasible strategy for constructing the underwater bubble manipulation system.

The Silk roads: phylogeography of Central Asian dice snakes (Serpentes: Natricidae) shaped by rivers in deserts and mountain valleys

Influenced by rapid changes in climate and landscape features since the Miocene,widely distributed species provide suitable models to study the environmental impact on their evolution and current genetic diversity.The dice snake Natrix tessellata,widely distributed in the Western Palearctic is one such species.We aimed to resolve a detailed phylogeography of N.tessellata with a focus on the Central Asian clade with 4 and the Anatolia clade with 3 mitochondrial lineages,trace their origin,and correlate the environmental changes that affected their distribution through time.The expected time of divergence of both clades began at 3.7 Mya in the Pliocene,reaching lineage differentiation approximately 1 million years later.The genetic diversity in both clades is rich,suggesting different ancestral areas,glacial refugia,demographic changes,and colonization routes.The Caspian lineage is the most widespread lineage in Central Asia,distributed around the Caspian Sea and reaching the foothills of the Hindu Kush Mountains in Afghanistan,and Eastern European lowlands in the west.Its distribution is limited by deserts,moun-tains,and cold steppe environments.Similarly,Kazakhstan and Uzbekistan lineages followed the Amu Darya and the Syr Darya water systems in Central Asia,with ranges delimited by the large Kyzylkum and Karakum deserts.On the western side,there are several lineages within the Anatolia clade that converged in the central part of the peninsula with 2 being endemic to Western Asia.The distribution of both main clades was affected by expansion from their Pleistocene glacial refugia around the Caspian Sea and in the valleys of Central Asia as well as by environmental changes,mostly through aridification.

Kinematic Structure of a Heavy Rain Event from Dual-Doppler Radar Observations

The detailed kinematic structure of a heavy rain event that occurred in the middle reaches of the Yangtze River was investigated using dual-Doppler radar observation. A variational analysis method was developed to obtain the three-dimensional wind fields. Before the analysis, a data preprocessing procedure was carried out, in which the temporal variation with the scanning time interval and the effect of the earth curvature on the data position were taken into account. The analysis shows that a shear line in the lower and middle levels played an important role in the rainfall event. The precipitation fell mainly on the south end of the shear line where southerly flow prevailed and convergence and updraft were obvious. With the movement and decay of the shear line, the precipitation moved and decayed correspondingly.

Simultaneous determination of amino acids in different teas using supercritical fluid chromatography coupled with single quadrupole mass spectrometry

Tea is a widely consumed beverage and has many important physiological properties and potential health benefits. In this study, a novel method based on supercritical fluid chromatography coupled with mass spectrometry (SFC-MS) was developed to simultaneously determine 11 amino acids in different types of tea (green teas, Oolong tea, black tea and Pu-erh tea). The separation conditions for the analysis of the selected amino acids including the column type, temperature and backpressure as well as the type of additive, were carefully optimized. The best separation of the 11 amino acids was obtained by adding water (5%, v/v) and trifluoroacetic acid (0.4%, v/v) to the organic modifier (methanol). Finally, the developed SFC-MS method was fully validated and successfully applied to the determination of these amino acids in six different tea samples. Good linearity (r ≥ 0.993), precision (RSDs≤ 2.99%), accuracy (91.95%-107.09%) as well as good sample stability were observed. The limits of detection ranged from 1.42 to 14.69 ng/mL, while the limits of quantification were between 4.53 and 47.0 ng/mL. The results indicate that the contents of the 11 amino acids in the six different tea samples are greatly influenced by the degree of fermentation. The proposed SFC-MS method shows a great potential for further investigation of tea varieties.

液压控制阀安装不当引起液压系统故障分析

0引言 技术人员在测试锁模力为3680kN的卧式塑料注塑机做出厂试验时，当电磁阀得电时，出现移模油缸向后爬行。经分析判断是由于电液阀的6只紧固螺钉安装不当引起。平时在工作中也时常碰到类似情况，下面就对此现象提出几点改进措施。

Determination of iohexol by capillary blood microsampling and UHPLC-MS/MS

One of the most important tools used to evaluate kidney function in the context of chronic kidney disease or other renal function related pathologies is the exploration of glomerular filtration rate (GFR). Iohexol is up to this moment a good candidate molecule for the GFR assessment since it exhibits minimum protein binding rates and minimum extra-renal clearance, being neither secreted nor reabsorbed at the tubular level. This study proposes and evaluates a new LC-MS/MS method for the iohexol determination from capillary blood, prelevated using volumetric absorbative microsampling (VAMS) systems. As an alternative to VAMS, a brand new HemaPEN■ device for micro-prelevation was also tested. A new high throughput sample preparation protocol adapted for iohexol quantification from whole blood VAMS samples was developed. The medium term stability study of iohexol in dried whole blood VAMS samples that was conducted showed a good stability of this molecule for up to 12 days. By collecting only 10 mL of blood, iohexol can be analyzed from dried whole blood VAMS samples for concentration ranges between 1 and 250 mg/mL. Due to the analyte stability in VAMS for up to 12 days, this approach might be successfully applied for GFR assessment for clinical cases allowing minimum invasiveness and even delayed analysis.

Intelligent Molding Proceeding of Composites and Intelligent Manufacturing Systems for Composite Materials

The technology of Intelligent cure operation is set forth according to developing tedency of smart material and structure. Intelligent-system-based tool was developed in order to operate the autoclave cure of a fiber reinforced thermosetting matrix composite laminate in an optimal manner.The objective function is comforts for minimizing the total cure time,uniforming the temperature distribution,controling exothermal and minimizing the process-induced residual stresses in the laminate.Data is analyzed on-line to determine the trends in real-time.The results from application of this overall strategy for the curing of composites are presented.