Method to measure tree-ring width,density,elemental composition,and stable carbon and oxygen isotopes using one sample

Tree-ring width(RW),density,elemental com-position,and stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)are widely used as proxies to assess climate change,ecology,and environmental pollution;however,a specific pretreat-ment has been needed for each proxy.Here,we developed a method by which each proxy can be measured in the same sample.First,the sample is polished for ring width meas-urement.After obtaining the ring width data,the sample is cut to form a 1-mm-thick wood plate.The sample is then mounted in a vertical sample holder,and gradually scanned by an X-ray beam.Simultaneously,the count rates of the fluorescent photons of elements(for chemical characteriza-tion)and a radiographic grayscale image(for wood density)are obtained,i.e.the density and the element content are obtained.Then,cellulose is isolated from the 1-mm wood plate by removal of lignin,and hemicellulose.After producing this cellulose plate,cellulose subsamples are separated by knife under the microscope for inter-annual and intra-annual stable carbon and oxygen isotope(δ^(13)C,δ^(18)O)analysis.Based on this method,RW,density,elemental composition,δ^(13)C,and δ^(18)O can be measured from the same sample,which reduces sample amount and treatment time,and is helpful for multi-proxy comparison and combination research.

Stable Isotope and Element Geochemistry of Saline Springs in Evaporite-bearing Mengla Basin,South Yunnan,China

1 Introduction Mengla Basin is a sub-basin in southern evaporitebearing Lanping-Simao Basin.There are many salt springs in the basin.In 2012,11 spring samples were collected for analyses of chemistry and boron,hydrogen and oxygen

Stable Isotopes and Halogen Geochemistry of the Huayuan Carbonate-hosted Pb-Zn Ore District, South China: Implications for the Salt Source of Ore-forming Fluids

The Huayuan Pb-Zn ore district in China,located in western Hunan Province,is a giant carbonate-hosted Pb-Zn ore district.The source of ore-forming brines in this ore district remains poorly constrained.Whether the highly saline brines are derived from evaporated seawater or dissolved evaporates continues to be intensely debated.Carbonate minerals associated with Pb-Zn mineralization haveδ^(13)CV-PDB andδ^(18)OV-SMOW values ranging from−5.55‰to+1.35‰(mean value of−0.69‰;n=14)and+16.28‰to+25.05‰(mean value of+20.22‰;n=14),respectively.This indicates that carbonate minerals are dominantly formed from dissolved ore-hosted carbonate rocks.Theδ^(34)S values of sulfides range from+20.2‰to+36.8‰,with an average value of+30.0‰(n=27).These results suggest that sulfur is predominantly derived from the thermochemical sulfate reduction of marine sulfate.The crush-leach analyzed solute data of fluid inclusions in sphalerite show the ore-forming fluids have Cl/Br molar ratios range from 118 to 384,and Na/Br molar ratios from 39 to 160(n=8).These Cl/Br ratios of hydrothermal fluid are much lower than those of seawater(657 to 564),but are consistent with bittern brines through early halite precipitation.We propose that ore-forming fluids are mainly derived from evaporitic basin brines,which leached base metals from the basement and/or country rocks.The brine then migrated to the basin margins through clastic rocks of basement and then precipitated sulfides by thermochemical sulfate reduction.

Bi-stable states of initially stressed elastic cylindrical shell structures with two piezoelectric surface layers

A theoretical model is proposed in this paper to predict the bi-stable states of initially stressed cylindrical shell structures attached by surface anisotropic piezoelectric layers.The condition for existence of bi-stability of the shell structural system is presented and analytical expressions for corresponding rolled-up radii of the stable shell are given based on the principle of minimum strain energy.The resulting solution indicates that the shell system may have two stable configurations besides its initial state under a combined action of the actuating electric field and initial stresses characterized by the bending moment.If the piezoelectric layer materials act as only sensor materials without the actuating electric field,initial stresses may produce the bi-stable states,but one corresponding to its initial state.For the shell without initial stresses,the magnitude in the actuating electric field determines the number of the stable states,one or two stable configurations besides the initial state.The theoretical prediction for the bi-stable states is verified by finite element method（FEM） simulation by using the ABAQUS code.

Two-Sided Stable Matching Decision-Making Method Considering Matching Intention under a Hesitant Fuzzy Environment

In this paper,a stable two-sided matching(TSM)method considering the matching intention of agents under a hesitant fuzzy environment is proposed.The method uses a hesitant fuzzy element(HFE)as its basis.First,the HFE preference matrix is transformed into the normalized HFE preference matrix.On this basis,the distance and the projection of the normalized HFEs on positive and negative ideal solutions are calculated.Then,the normalized HFEs are transformed into agent satisfactions.Considering the stable matching constraints,a multiobjective programming model with the objective of maximizing the satisfactions of two-sided agents is constructed.Based on the agent satisfaction matrix,the matching intention matrix of two-sided agents is built.According to the agent satisfaction matrix and matching intention matrix,the comprehensive satisfaction matrix is set up.Furthermore,the multiobjective programming model based on satisfactions is transformed into a multiobjective programming model based on comprehensive satisfactions.Using the G-S algorithm,the multiobjective programming model based on comprehensive satisfactions is solved,and then the best TSM scheme is obtained.Finally,a terminal distribution example is used to verify the feasibility and effectiveness of the proposed method.

lncRNA SNHG4 enhanced gastric cancer progression by modulating miR-409-3p/CREB1 axis

Objective:Gastric cancer(GC)is a globally common cancer characterized by high incidence and mortality worldwide.Advances in the molecular understanding of GC provide promising targets for GC diagnosis and therapy.Long non-coding RNAs(lncRNAs)and their downstream regulators are regarded to be implicated in the progression of multiple types of malignancies.Studies have shown that the lncRNA small nucleolar RNA host gene 4(SNHG4)serves as a tumor promoter in various malignancies,while its function in GC has yet to be characterized.Therefore,our study aimed to explore the role and underlying mechanism of SNHG4 in GC.Methods:We used qRT-PCR to analyze SNHG4 expression in GC tissues and cells.Kaplan-Meier analysis was used to assess the correlation between SNHG4 expression and the survival rate of GC patients.Cellular function experiments such as CCK-8,BrdU,colony formation,flow cytometry analysis,and transwell were performed to explore the effects of SNHG4 on GC cell proliferation,apoptosis,cell cycle,migration,and invasion.We also established xenograft mouse models to explore the effect of SNHG4 on GC tumor growth.Mechanically,dual luciferase reporter assay was used to verify the interaction between SNHG4 and miR-409-3p and between miR-409-3p and cAMP responsive element binding protein 1(CREB1).Results:The results indicated that SNHG4 was overexpressed in GC tissues and cell lines,and was linked with poor survival rate of GC patients.SNHG4 promoted GC cell proliferation,migration,and invasion while inhibiting cell apoptosis and cell cycle arrest in vitro.The in vivo experiment indicated that SNHG4 facilitated GC tumor growth.Furthermore,SNHG4 was demonstrated to bind to miR-409-3p.Moreover,CREB1 was directly targeted by miR-409-3p.Rescue assays demonstrated that miR-409-3p deficiency reversed the suppressive impact of SNHG4 knockdown on GC cell malignancy.Additionally,miR-409-3p was also revealed to inhibit GC cell proliferation,migration,and invasion by targeting CREB1.Conclusion:In conclusion,we verified that the SNHG4 promoted GC growth and metastasis by binding to miR-409-3p to upregulate CREB1,which may deepen the understanding of the underlying mechanism in GC development.

元素分析-稳定同位素比质谱联用仪日常使用及常见故障排除方法

介绍了元素分析-稳定同位素比质谱联用仪的工作原理,总结了该仪器的日常使用技巧,提出了元素峰面积异常、系统检漏、系统堵塞、加热炉环境温度太高、球阀拆洗、离子源清洗等常见故障的排查方法,供仪器设备管理员和分析测试人员参考使用。

Quantification of photosynthetic inorganic carbon utilisation via a bidirectional stable carbon isotope tracer

The amount of bicarbonate utilised by plants is usually ignored because of limited measurement methods. Accordingly, this study quantified the photosynthetic assimilation of inorganic carbon （COe and HCO3-） by plants. The net photosynthetic COa assimilation （PN）, the photosynthetic assimilation of CO2 and bicarbonate （PN＇）, the proportion of increased leaf area （lEA） and the stable carbon isotope composition （δ13C） of Orychophragmus violaceus （Ov） and Brassica juncea （B j） under three bicarbonate levels （5, 10 and 15 mm NaHCO3） were examined to determine the relationship among PN, PN＇ and fLA. PN＇, not PN, changed synchronously with fLA. Moreover, the proportions of exogenous bicarbonate and total bicarbonate （including exogenous bicarbonate and dissolved CO2-generated bicarbonate） utilised by Ov were 2.27 % and 5.28 % at 5 mm bicarbonate, 7.06 % and 13.28 % at 10 mm bicarbonate, and 8.55 % and 17.31% at 15 mm bicarbonate, respectively. Meanwhile, the propor- tions of exogenous bicarbonate and total bicarbonate uti- lised by Bj were 1.77 % and 3.28 % at 5 mm bicarbonate, 2.11% and 3.10 % at 10 mm bicarbonate, and 2.36 % and 3.09 % at 15 mm bicarbonate, respectively. Therefore, the dissolved CO2-generated bicarbonate and exogenous bicarbonate are important sources of inorganic carbon for plants.

Reduced-order finite element method based on POD for fractional Tricomi-type equation

The reduced-order finite element method （FEM） based on a proper orthogo- nal decomposition （POD） theory is applied to the time fractional Tricomi-type equation. The present method is an improvement on the general FEM. It can significantly save mem- ory space and effectively relieve the computing load due to its reconstruction of POD basis functions. Furthermore, the reduced-order finite element （FE） scheme is shown to be un- conditionally stable, and error estimation is derived in detail. Two numerical examples are presented to show the feasibility and effectiveness of the method for time fractional differential equations （FDEs）.

Construction of n-sided polygonal spline element using area coordinates and B-net method

In general, triangular and quadrilateral elements are commonly applied in two-dimensional finite element methods. If they are used to compute polycrystalline materials, the cost of computation can be quite significant. Polygonal elements can do well in simulation of the materials behavior and provide greater flexibility for the meshing of complex geometries. Hence, the study on the polygonal element is a very useful and necessary part in the finite element method. In this paper, an n-sided polygonal element based on quadratic spline interpolant, denoted by PS2 element, is presented using the triangular area coordinates and the B-net method. The PS2 element is conforming and can exactly model the quadratic field. It is valid for both convex and non-convex polygonal element, and insensitive to mesh distortions. In addition, no mapping or coordinate transformation is required and thus no Jacobian matrix and its inverse are evaluated. Some appropriate examples are employed to evaluate the performance of the proposed element.

A boundary element method for the simulation of non-spherical bubbles and their interactions near a free surface

The basic principle and numerical technique for simulating two three-dimensional bubbles near a free surface are studied in detail by using boundary element method. The singularities of influence coefficient matrix are eliminated using coordinate transformation and so-called 4π rule. The solid angle for the open surface is treated in direct method based on its definition. Several kinds of configurations for the bubbles and free surface have been investigated. The pressure contours during the evolution of bubbles are obtained in our model and can better illuminate the mechanism underlying the motions of bubbles and free surface. The bubble dynamics and their interactions have close relation with the standoff distances, buoyancy parameters and initial sizes of bubbles. Completely different bubble shapes, free surface motions, jetting patterns and pressure distributions under different parameters can be observed in our model, as demon- strated in our calculation results.

Two 8-node quadrilateral spline elements by B-net method

Isoparametric quadrilateral elements are widely used in the finite element method, but the accuracy of the isoparametric quadrilateral elements will drop obviously deteriorate due to mesh distortions. Spline functions have some properties of simplicity and conformality. Two 8-node quadrilateral elements have been developed using the trian- gular area coordinates and the B-net method, which can ex- actly model the quadratic field for both convex and concave quadrangles. Some appropriate examples are employed to evaluate the performance of the proposed elements. The nu- merical results show that the two spline elements can obtain solutions which are highly accurate and insensitive to mesh distortions.

A Numerical Algorithm Based on Quadratic Finite Element for Two-Dimensional Nonlinear Time Fractional Thermal Diffusion Model

In this article,a high-order scheme,which is formulated by combining the quadratic finite element method in space with a second-order time discrete scheme,is developed for looking for the numerical solution of a two-dimensional nonlinear time fractional thermal diffusion model.The time Caputo fractional derivative is approximated by using the L2-1formula,the first-order derivative and nonlinear term are discretized by some second-order approximation formulas,and the quadratic finite element is used to approximate the spatial direction.The error accuracy O(h3+
t2)is obtained,which is verified by the numerical results.

A hybrid vertex-centered finite volume/element method for viscous incompressible flows on non-staggered unstructured meshes

This paper proposes a hybrid vertex-centered fi- nite volume/finite element method for solution of the two di- mensional （2D） incompressible Navier-Stokes equations on unstructured grids. An incremental pressure fractional step method is adopted to handle the velocity-pressure coupling. The velocity and the pressure are collocated at the node of the vertex-centered control volume which is formed by join- ing the centroid of cells sharing the common vertex. For the temporal integration of the momentum equations, an im- plicit second-order scheme is utilized to enhance the com- putational stability and eliminate the time step limit due to the diffusion term. The momentum equations are discretized by the vertex-centered finite volume method （FVM） and the pressure Poisson equation is solved by the Galerkin finite el- ement method （FEM）. The momentum interpolation is used to damp out the spurious pressure wiggles. The test case with analytical solutions demonstrates second-order accuracy of the current hybrid scheme in time and space for both veloc- ity and pressure. The classic test cases, the lid-driven cavity flow, the skew cavity flow and the backward-facing step flow, show that numerical results are in good agreement with the published benchmark solutions.

Elemental Concentrations in Biological Samples of Coronavirus Disease (COVID-19) and Other Pulmonary Disease Patients

Background: Recently, Coronavirus Disease 2019 (COVID-19) has been affected by the extreme acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has developed important global health anxiety. At this time, the treatment options for this disease are only moderately successful. Smoking has been related to COVID-19 and its mortality, and it has the potential to affect bacteriological and viral conversion, clinical effects, and treatment outcomes. Methods: The aim of this study was to determine the relationship between critical essential trace {zinc (Zn), iron (Fe), and copper (Cu)} and toxic {cadmium (Cd) and nickel (Ni)} elements in human biological samples such as scalp hair, serum, saliva, blood, nasal fluid, and sputum of smoking and nonsmoking male COVID-19 patients (n = 139, age range 25 - 38 years) from Hyderabad, Pakistan. For comparative purposes, the biological specimens of referent persons (n = 83), pulmonary Tuberculosis (T.B) patients (n = 67), Pneumonia (n = 56) of the same age groups were also be analyzed. Microwave oven mediated digestion method was employed, and digestion of samples was carried out with the help of 2:1 mixture solution of HNO3 (65%) and H2O2 (30%). Atomic absorption spectrometry was employed for the determination of elemental concentrations from the microwave oven employed digested samples. Results: The found average of essential elements (Zn, Fe, and Cu) in biological specimens of smoker and nonsmoker male COVID-19, T.B, and Pneumonia patients was found to lower, whilst cadmium and nickel were found to be higher when compared with samples from referents (p < 0.001). Conclusions: Improved elemental (Cu, Fe, Zn) concentrations may also decrease the risk of bacterial co-infection by enhancing the mucociliary clearance and respiratory epithelial barrier function, in addition to providing direct antibacterial effects against S. pneumoniae. Our findings also suggest that higher Cd and Ni concentrations are linked to cigarette smoking, which could lead to COVID-19 and other lung-infected diseased recurrences. However, further clinical and experimental research is required.

IMPLICIT-EXPLICIT MULTISTEP FINITE ELEMENT-MIXED FINITE ELEMENT METHODS FOR THE TRANSIENT BEHAVIOR OF A SEMICONDUCTOR DEVICE

The transient behavior of a semiconductor device consists of a Poisson equation for the electric potential and of two nonlinear parabolic equations for the electron density and hole density. The electric potential equation is discretized by a mixed finite element method. The electron and hole density equations are treated by implicit-explicit multistep finite element methods. The schemes are very efficient. The optimal order error estimates both in time and space are derived.

基于EA-IRMS的婴幼儿奶粉及其酪蛋白中δ^(13)C和δ^(15)N的检测方法优化和不同产源地的差异研究

以婴幼儿奶粉和其中的酪蛋白为研究对象,建立了基于元素分析-稳定同位素比质谱法(EA-IRMS)同时测定δ^(13)C和δ^(15)N的方法。通过优化称样量和样品CO_(2)稀释倍数得到最佳测定条件。结果表明,在称样量600~700μg、8倍样品CO_(2)稀释倍数条件下,样品中δ^(13)C和δ^(15)N标准偏差(SD)均<0.3‰,标准质控样与证书差值均在质量控制要求内。对来自国内外50批次婴幼儿奶粉及其中酪蛋白的δ^(13)C和δ^(15)N进行检测,发现来自各地区的婴幼儿奶粉和酪蛋白中δ^(13)C存在一定差异,而δ^(15)N呈现出较小的差异化,这些特征可以为婴幼儿奶粉确定产源地提供参考。

The 5’-Untranslated Region of the C9orf72 mRNA Exhibits a Phylogenetic Alignment to the Cis-Aconitase Iron-Responsive Element;Novel Therapies for Amytrophic Lateral Sclerosis

The hexanucleotide repeat mutation in the intron-1 of the chromosome 9 open reading frame (C9orf72) is a frequent cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Altered RNA folding plays a role in ALS pathogenesis in two ways: non-ATG translation of the repeat can lead to aggregates of the known C9orf72 specific dipeptide polymer, whereas the repeat also can form neurotoxic RNA inclusions that dose-responsively kill motor neurons. We report the presence of a homology in the 5’untranslated region (UTR) of the messenger RNA encoding C9orf72 with the iron responsive elements (IRE) that control expression of iron-associated transcripts and predict that this RNA structure may iron-dependently regulate C9orf72 translation. We previously report altered serum ferritin levels track with severity of ALS in patients. Here, we conduct bioinformatics analyses to determine the secondary structure of the 5’UTR in C9orf72 mRNA and find it aligned with IREs in the human mitochondrial cis-aconitase and L and H-ferritin transcripts. Comparison of the role of RNA repeats in Friedriech’s ataxia and fragile X mental retardation suggests the utility of RNA based therapies for treatment of ALS. Antisense oligonucleotides (ASO) have been reported to therapeutically target these GGGGCC repeats. At the same time, because the function of C9orf72 is unknown, knockdown strategies carry some risk of inducing or compounding haploinsufficiency. We propose, for consideration, an approach that may enhance its therapeutic dynamic range by increasing the 5’UTR driven translation of C9orf72 protein to compensate for any potential ALS-specific or ASO-induced haploinsufficieny.

Finite Element Simulation of the Polymeric Liquid Flow in Coat-hanger Die

A three - dimenslonal finite element model is developed to deal with the polymeric liquid flow in coat - hanger die. This model is used to predict the flow behavior of the 2％ CMC/watsr solution in the coat - hanger die with linearly taper manifolds and its validity is experimentally verified quantitatively and qualitatively by using Laser Doppler Velocimetry and Particle Image Velocimetry respectively.

茶叶中同位素与多元素特征及其原产地PCA-LDA判别研究

本研究采用稳定同位素质谱和等离子发射光谱质谱法测定茶叶中同位素比率和多元素含量,并结合主成分分析(PCA)和线性判别分析(LDA)法建立模型,对福建、山东和浙江出产的茶叶,以及浙江余姚、金华和西湖出产的茶叶进行产地溯源判定。结果表明,不同产地的茶叶中稳定同位素δ15N、δ13C、δD、δ18O数值范围不同,而且Li、Be和Na等27个矿物元素的含量变化也较大,具有一定的地域特征。PCA法能够区分不同产地的茶叶,但不同产地样本存在部分重合;而采用PCA-LDA法能够有效区分不同产地的茶叶,其中福建、山东和浙江产地的判定准确率为99%,浙江余姚、金华和西湖产地的判定准确率为86%。因此,利用稳定同位素和矿物多元素检测结合PCA-LDA法能够较好进行茶叶产地溯源,具有一定的可行性和应用价值。