Hemogram-derived ratios as prognostic markers for major adverse cardiovascular events in patients with non-ST-segment elevation myocardial infarction

BACKGROUND Non-ST segment elevation myocardial infarction(NSTEMI)poses significant challenges in clinical management due to its diverse outcomes.Understanding the prognostic role of hematological parameters and derived ratios in NSTEMI patients could aid in risk stratification and improve patient care.AIM To evaluate the predictive value of hemogram-derived ratios for major adverse cardiovascular events(MACE)in NSTEMI patients,potentially improving clinical outcomes.METHODS A prospective,observational cohort study was conducted in 2021 at the Internal Medicine Clinic of the University Hospital in Tuzla,Bosnia and Herzegovina.The study included 170 patients with NSTEMI,who were divided into a group with MACE and a control group without MACE.Furthermore,the MACE group was subdivided into lethal and non-lethal groups for prognostic analysis.Alongside hematological parameters,an additional 13 hematological-derived ratios(HDRs)were monitored,and their prognostic role was investigated.RESULTS Hematological parameters did not significantly differ between non-ST segment elevation myocardial infarction(NSTEMI)patients with MACE and a control group at T1 and T2.However,significant disparities emerged in HDRs among NSTEMI patients with lethal and non-lethal outcomes post-MACE.Notably,neutrophil-to-lymphocyte ratio(NLR)and platelet-to-lymphocyte ratio(PLR)were elevated in lethal outcomes.Furthermore,C-reactive protein-to-lymphocyte ratio(CRP/Ly)at T1(>4.737)demonstrated predictive value[odds ratio(OR):3.690,P=0.024].Both NLR at T1(>4.076)and T2(>4.667)emerged as significant predictors,with NLR at T2 exhibiting the highest diagnostic performance,as indicated by an area under the curve of 0.811(95%CI:0.727-0.859)and OR of 4.915(95%CI:1.917-12.602,P=0.001),emphasizing its important role as a prognostic marker.CONCLUSION This study highlights the significant prognostic value of hemogram-derived indexes in predicting MACE among NSTEMI patients.During follow-up,NLR,PLR,and CRP/Ly offer important insights into the inflammatory processes underlying cardiovascular events.

Isotopic dependence of the yield ratios of light fragments from different projectiles and their unified neutron skin thicknesses

The yield ratios of neutron-proton(R(n/p))and^(3)H-^(3)He(R(^(3)H∕^(3)He))with reduced rapidity from 0 to 0.5 were simulated at 50 MeV/u even-even ^(36−56)Ca+^(40)Ca,even-even ^(48−78)Ni+^(58)Ni,and ^(100−139)Sn(every third isotopes)+112 Sn for full reduced impact parameters using the isospin-dependent quantum molecular dynamics(IQMD)model.The neutron and proton density distributions and root-mean-square radii of the reaction systems were obtained using the Skyrme-Hartree-Fock model,which was used for the phase space initialization of the projectile and target in IQMD.We defined the unified neutron skin thickness asΔRnp=<r^(2)>^(1∕2) n−<r^(2)>^(1∕2)p,which was negative for neutron-deficient nuclei.The unifiedΔRnp values for nuclei with the same relative neutron excess from different isotopic chains were nearly equal,except for extreme neutron-rich isotopes,which is a type of scaling behavior.The yield ratios of the three isotopic chain-induced reactions,which depended on the reduced impact parameter and unified neutron skin thickness,were studied.The results showed that both R(n/p)and R(^(3)H∕^(3)He)decreased with a reduced impact parameter for extreme neutron-deficient isotopes;however,they increased with reduced impact parameters for extreme neutron-rich isotopes,and increased with theΔRnp of the projectiles for all reduced impact parameters.In addition,a scaling phenomenon was observed betweenΔR np and the yield ratios in peripheral colli-sions from different isotopic chain projectiles(except for extreme neutron-rich isotopes).Thus,R(n/p)and R(^(3)H∕^(3)He)from peripheral collisions were suggested as experimental probes for extracting the neutron or proton skin thicknesses of non-extreme neutron-rich nuclei from different isotopic chains.

Calcium-Magnesium Ca/Mg Ratios and Their Agronomic Implications for the Optimization of Phosphate Fertilization in Rainfed Rice Farming on Acidic Ferralsol in the Forest Zone of Ivory Coast

This study is a contribution to improving rice productivity on acidic plateau soils of the tropical rainforest zone. It is based on taking into account the cationic balances of the soil in order to optimize the phosphorus (P) nutrition of rice on these acidic soils, where this nutrient constitutes a limiting factor for agricultural production. Three (3) pot trials were conducted in Adiopodoumé in the forested south of Côte d’Ivoire. The interactive effects of calcium carbonate (0, 25, 50 and 75 kg Ca ha−1) and magnesium sulfate (0, 25, 50 and 75 kg Mg ha−1) were evaluated on the response of NERICA 5 rice at doses 0, 25, 50 and 75 kg P ha−1 of natural phosphate from Togo, applied only once at the start of the experiment. Additional fertilizers of nitrogen (N) (100 kg N ha−1) and potassium (K) (50 kg KCl ha−1) were added to each of the tests in a split-plot device. The test results revealed a paddy production potential of approximately 3 to 5 t⋅ha−1 for NERICA 5 on an acidic soil, under the effect of the interaction of P, Ca and Mg. The quadratic response of rice yield to the doses of these fertilizers would be more dependent on their balance, itself influenced by Ca nutrition. For the sustainability and maintenance of rice production in agro-ecology studied, it was recommended doses of 38 kg Ca ha−1, 34 kg Mg ha−1 in a Ca/Mg ratio (1/1) with intakes of 41 kg P ha−1, overall in a ratio 1/1/1 (P/Ca/Mg) more favorable to the availability of free iron considered a guiding element of mineral nutrition. Thus, these promising results should be confirmed in a real environment for better management of the fertilization of rice cultivated on acidic plateau soils in Côte d’Ivoire.

Experimental Study of Local Scour Around Four Piles Under Different Attack Angles and Gap Ratios

In an effort to investigate and quantify the patterns of local scour,researchers embarked on an in-depth study using a systematic experimental approach.The research focused on the effects of local scour around a set of four piles,each subjected to different hydromechanical conditions.In particular,this study aimed to determine how different attack angles—the angles at which the water flow impinges on the piles,and gap ratios—the ratios of the spacing between the piles to their diameters,influence the extent and nature of scour.A comprehensive series of 35 carefully designed experiments were orchestrated,each designed to dissect the nuances in how the gap ratio and attack angle might contribute to changes in the local scour observed at the base of pile groups.During these experimental trials,a wealth of local scour data were collected to support the analysis.These data included precise topographic profiles of the sediment bed around the pile groups,as well as detailed scour time histories showing the evolution of scour at strategic feature points throughout the test procedure.The analysis of the experimental data provided interesting insights.The study revealed that the interplay between the gap ratio and the attack angle had a pronounced influence on the scouring dynamics of the pile groups.One of the key observations was that the initial phases of scour,particularly within the first hour of water flow exposure,were characterized by a sharp increase in the scour depth occurring immediately in front of the piles.After this initial rapid development,the scour depth transitioned to a more gradual change rate.In contrast,the scour topography around the piles continuously evolved.This suggests that sediment displacement and the associated sculpting of the seabed around pile foundations are sustained and progressive processes,altering the underwater landscape over time.The results of this empirical investigation have significant implications for the design and construction of offshore multi-pile foundations,providing a critical reference for engineers and designers to estimate the expected scour depth around such structures,which is an integral part of decisions regarding foundation design,selection of structural materials,and implementation of scour protection measures.

An Experimental and Numerical Thermal Flow Analysis in a Solar Air Collector with Different Delta Wing Height Ratios

This study conducts both numerical and empirical assessments of thermal transfer and fluid flow characteristics in a Solar Air Collector(SAC)using a Delta Wing Vortex Generator(DWVG),and the effects of different height ratios(Rh=0.6,0.8,1,1.2 and 1.4)in delta wing vortex generators,which were not considered in the earlier studies,are investigated.Energy and exergy analyses are performed to gain maximum efficiency.The Reynolds number based on the outlet velocity and hydraulic diameter falls between 4400 and 22000,corresponding to the volume flow rate of 5.21–26.07 m^(3)/h.It is observed that the delta wing vortex generators with a higher height ratio yield maximum heat transfer enhancement and overall enhancement ratio.The empirical and numerical findings demonstrate that the exergy and thermal efficiencies decline in a specific range.TheNusselt number,pressure drop,energy,and exergy efficiencies enhance with rising Reynolds number,although the friction coefficient diminishes.The maximum heat transfer enhancement is 57%.According to the evaluation of exergy efficiency,the greatest efficiency of 31.2%is obtained at Rh=1.4 and Reynolds number 22000.

Using Pearson’s System of Curves to Approximate the Distributions of the Difference between Two Correlated Estimates of Signal-to-Noise Ratios: The Cases of Bivariate Normal and Bivariate Lognormal Distributions

Background: The signal-to-noise ratio (SNR) is recognized as an index of measurements reproducibility. We derive the maximum likelihood estimators of SNR and discuss confidence interval construction on the difference between two correlated SNRs when the readings are from bivariate normal and bivariate lognormal distribution. We use the Pearsons system of curves to approximate the difference between the two estimates and use the bootstrap methods to validate the approximate distributions of the statistic of interest. Methods: The paper uses the delta method to find the first four central moments, and hence the skewness and kurtosis which are important in the determination of the parameters of the Pearsons distribution. Results: The approach is illustrated in two examples;one from veterinary microbiology and food safety data and the other on data from clinical medicine. We derived the four central moments of the target statistics, together with the bootstrap method to evaluate the parameters of Pearsons distribution. The fitted Pearsons curves of Types I and II were recommended based on the available data. The R-codes are also provided to be readily used by the readers.

Humic Acid Effects on Reducing Corn Leaf Burn Caused by Foliar Spray of Urea-Ammonium Nitrate at Different Humic Acid/Urea-Ammonium Nitrate Ratios

Technologies for reducing corn leaf burn caused by foliar spray of urea-ammonium nitrate (UAN) during the early growing season are limited. A field experiment was carried out to evaluate the effects of humic acid on corn leaf burn caused by foliar spray of undiluted UAN solution on corn canopy at Jackson, TN in 2018. Thirteen treatments of the mixtures of UAN and humic acid were evaluated at V6 of corn with different UAN application rates and different UAN/humic acid ratios. Leaf burn during 1 2, 3, 4, 5, 6, 7, and 14 days after UAN foliar spray significantly differed between with or without humic acid addition. The addition of humic acid to UAN significantly reduced leaf burn at each UAN application rate (15, 25, and 35 gal/acre). The reduction of leaf burn was enhanced as the humic acid/UAN ratio went up from 10% to 30%. Leaf burn due to foliar application of UAN became severer with higher UAN rates. The linear regression of leaf burn 14 days after application with humic acid/UAN ratio was highly significant and negative. However, the linear regression of leaf burn 14 days after application with the UAN application rate was highly significant and positive. In conclusion, adding humic acid to foliar-applied UAN is beneficial for reducing corn leaf burn during the early growing season.

Binary Phase Shaping and SHG Contrast Ratios

Finding binary sequences with Large SHG ratios is very important in the field of ultrafast science, biomedical optics, high-resolution microscopy and label-free imaging. In this paper, we have demonstrated the relation between the SHG contrast ratio and the traditional Merit Factor values. And in the light from known results in Merit Factor Problems, we have shown that Legendre Sequences or Jacobi Sequences, are still the best candidates to obtain binary sequences with large SHG contrast ratios. The authors also discussed the SHG behaviors on some sequences obtained from cyclotomic classes over the finite field GF (2l) .

Theoretical and Experimental Analyses of Poisson Ratios for Plain-Woven Fabrics

A theoretical model with extensible yarns for plain-woven fabrics is developed to determine the calculation of Poisson ratios.The stress ratio( warp: weft),as one of parameters corresponding to Poisson ratio variations, is introduced to complement the theoretical model. To evaluate the reliability of the theoretical analysis,a series of biaxial tensile tests of a plain-woven fabric with nine stress ratios are conducted carefully,and the theoretical results are compared with the experimentally measured values. The effects of other influencing factors, including geometric and mechanical parameters of yarns,on Poisson ratios are analyzed thoroughly.This solution method could be applied without difficulty to estimations of Poisson ratios and realistic designs for plain-woven fabrics.

A 1000-year record of Mg/Li and Li/Ca ratios of ostracod shells in Lake Qinghai,NE Tibetan Plateau

1 Introduction Lake Qinghai,famous as the largest inland saline lake in China,located on the high-altitude northeastern Tibetan Plateau,and four junctional zones of the East Asian summer monsoon(EASM),Indian summer monsoon(ISM),East Asian winter monsoon and the westerly jet stream prevail,making it sensitive to global climate change

Monomer reactivity ratios for fluoroacrylate and butyl methacrylate in miniemulsion copolymerizations initiated by potassium persulphate

Miniemulsion copolymerization of butyl mathacrylate （BMA） with fluoroacrylate （HFMA, TFMA） was carried out at 70 ℃ by employing potassium persulphate （KPS） as initiator. Copolymer compositions at low conversion levels were determined by ^1H NMR spectra techniques. The reactivity ratios were evaluated by employing Kellen-Tudos （K-T） methods, which yields the apparent reactivity ratios, rBMA = 0.74, rHFMA = 0.87 and rBMA = 0.73, rTFMA = 0.75, respectively, and Q- and e-values of HFMA and TFMA were calculated by the Alfrey-Price method. The results show that HFMA and TFMA are more active than BMA, and the cross-propagation rate constant is greater than the self-propagation one in these two copolymerizations.

OPTIMUM OF PRESSURE RATIOS OF MULTI-STAGE RECIPROCATING COMPRESSOR WITH PRACTICAL INTER-COOLING

The optimum pressure ratio distribution of a multistage reciprocating compressor is presented based on the assumption, i.e. the inter stage cooling is perfect and there are no pressure losses. The optimization of the two or three stage pressure ratio is analyzed in two cases of constant heat transfer rate for the inter cooler or constant inter stage inlet temperature, based on the minimum of the sum of theoretical compression power at each stage about a multi stage reciprocating compressor. Furthermore, with an example of two stage compressor the influence on the sum of the power of each stage is analyzed when practical pressure ratio deviates from the optimum value. It is obtained that under different cooling conditions the optimum pressure ratio distribution of the multi stage compression is various, and the change of the optimum pressure ratio within a small range has little influence on the sum of the power each stage. For the two stage compression, this range can be represented as ε 1=(0 96～1 06)ε 1j .

Effects of Dietary Concentrate to Forage Ratios on Production Performance and Serum Biochemical Indicators in Post-fattening Hainan Yellow Cattle

[Objective]The paper was to investigate the effects of dietary concentrate to forage ratios on production performance and serum bio-chemical indicators of post-fattening Hainan Yellow Cattle.[Method]Sixteen Hainan Yellow Cattles with the same genetic backgrounds and similar initial weight of(242.22 ±0.71 kg) were randomly divided into four treatments.Cattles were fed with diets of different concentrate to forage ratios(20:80, group Ⅰ;30:70, Group Ⅱ;40:60, group Ⅲ;50:50, group Ⅳ).The trial lasted 62 d.[Result]The daily gain in experimental group Ⅳ was significantly higher than that in experimental group Ⅱ(P<0.05), but the feed gain ratio in experimental group Ⅳ was lower than those in other ex-perimental groups(P>0.05).The feed intake in experimental group Ⅳ was also markedly higher than those in experimental groups Ⅰ and Ⅱ(P<0.05).Compared with the experimental group Ⅱ, the gross profit of experimental group Ⅳ was significantly promoted(P<0.05).The alanine aminotransferase and aspartate aminotransferase activities in experimental group Ⅱ were markedly higher than those in experimental groups Ⅰ, Ⅲ and Ⅳ.[Conclusion]When the dietary concentrate to forage ratios was 50∶50, the production performance of post-fattening Hainan Yellow Cattle was better.

Characterization of the Growth,Chlorophyll Content and Lipid Accumulation in a Marine Microalgae Dunaliella tertiolecta under Different Nitrogen to Phosphorus Ratios

Microalgal lipids are regarded as main future feedstock of biofuels for its higher efficiency of accumulation and sus- tainable production. In order to investigate the effect of various nitrogen to phosphorus ratios on cells growth, chlorophyll content and accumulation of lipids in Dunaliella tertiolecta, experiments were carried out in modified microalgal medium with inorganic nitrogen （nitrate-nitrogen） or organic nitrogen （urea-nitrogen） as the sole nitrogen source at initial N：P ratios ranging from 1：1 to 32：1. The favorable N：P of 16：1 in the nitrate-N or urea-N medium yielded the maximum cell density and specific growth rate. Decrease in chlorophyll content were observed at the N：P of 4：1 in both nitrate-N and urea-N cultures. It was also observed that the maximum lipids concentration was obtained at the N：P of 4：1 in both nitrate and urea nutrient medium. The lipid productivity and lipid content of cultures in the urea-N medium at the N：P of 4： lwere markedly higher than those from cultures with other N：P ratios （p〈 0.05）. The results of this work illustrate the possibility that higher ratios of nitrogen to phosphorus have enhancing effect on cells growth of D. tertiolecta. Conversely, higher lipid accumulation is associated with a decrease in chlorophyll content under lower ratios of nitro- gen to phosphorus. The results confirm the hypothesis of this study that a larger metabolic flux has been channeled to lipid accumu- lation in D. tertiolecta cells when the ratios of nitrogen to phosphorus drop below a critical level.

Prognostic value of neutrophil/lymphocyte,platelet/lymphocyte,lymphocyte/monocyte ratios and Glasgow prognostic score in osteosarcoma:A meta-analysis

BACKGROUND Some studies investigated the prognostic role of several blood biomarkers,including the neutrophil/lymphocyte ratio(NLR),platelet/lymphocyte ratio(PLR),lymphocyte/monocyte ratio(LMR)and Glasgow prognostic score(GPS),in osteosarcoma,but their results were inconsistent with each other.AIM To identify the prognostic value of NLR,PLR,LMR and GPS in osteosarcoma patients through reviewing relevant studies.METHODS The PubMed,EMBASE,Web of Science and CNKI databases were searched up to October 2,2021.The primary and second outcomes were overall survival(OS)and disease-free survival(DFS),respectively.The hazard ratios(HRs)with 95%confidence intervals(CIs)were combined to assess the association between these indicators and prognosis of osteosarcoma patients.RESULTS A total of 13 studies involving 2087 patients were eventually included.The pooled results demonstrated that higher NLR and GPS were significantly associated with poorer OS(HR=1.88,95%CI:1.38-2.55,P<0.001;HR=2.19,95%CI:1.64-2.94,P<0.001)and DFS(HR=1.67,95%CI:1.37-2.04,P<0.001;HR=2.50,95%CI:1.39-4.48,P<0.001).However,no significant relationship of PLR and LMR and OS(P=0.085;P=0.338)and DFS(P=0.396;P=0.124)was observed.CONCLUSION Higher NLR and GPS were related with worse prognosis and might serve as novel prognostic indicators for osteosarcoma patients.

Effect of Saccharomyces cerevisiae on alfalfa nutrient degradation characteristics and rumen microbial populations of steers fed diets with different concentrate-to-forage ratios

Live yeast（Saccharomyces cerevisiae） constitutes an effective additive for animal production;its probiotic effect may be related to the concentrate-to-forage ratio（CTFR）.The objective of this study was to assess the effects of S.cerevisiae（SC） on fiber degradation and rumen microbial populations in steers fed diets with different levels of dietary concentrate.Ten Simmental × Local crossbred steers（450 ± 50 kg BW） were assigned to a control group or an SC group.Both groups were fed the same basal diet but the SC group received SC supplementation（8 × 10^9 cfu/h/d through the ruminal fistula）following a two-period crossover design.Each period consisted of four phases,each of which lasted 17 d：10 d for dietary adaptation,6 d for degradation study,and 1 d for rumen sample collection.From the 1^（st） to the 4^（th） phase,steers were fed in a stepwise fashion with increasing CTFRs,i.e.,30：70,50：50,70：30,and 90：10.The kinetics of dry matter and fiber degradation of alfalfa pellets were evaluated;the rumen microbial populations were detected using real-time PCR.The results revealed no significant（P〉 0.05） interactions between dietary CTFR and SC for most parameters.Dietary CTFR had a significant effect（P〈 0.01） on degradation characteristics of alfalfa pellets and the copies of rumen microorganism;the increasing concentrate level resulted in linear,quadratic or cubic variation trend for these parameters.SC supplementation significantly（P〈 0.05） affected dry matter（DM） and neutral detergent fiber（NDF）degradation rates（c_（DM）,c_（NDF）） and NDF effective degradability（ED_（NDF））.Compared with the control group,there was an increasing trend of rumen fungi and protozoa in SC group（P 〈 0.1）;copies of total bacteria in SC group were significantly higher（P〈 0.05）.Additionally,percentage of Ruminobacter amylophilus was significantly lower（P〈 0.05）but percentage of Selenomonas ruminantium was significantly higher（P〈 0.05） in the SC group.In a word,dietary CTFR had a significant effect on degradation characteristics of forage and rumen microbial population.S.cerevisiae had positive effects on DM and NDF degradation rate or effective degradability of forage;S.cerevisiae increased rumen total bacteria,fungi,protozoa,and lactate-utilizing bacteria but reduced starch-degrading and lactate-producing bacteria.

Seasonal changes in TC and WSOC and their ^13C isotope ratios in Northeast Asian aerosols： land surface–biosphere–atmosphere interactions

In order to understand the relative importance of anthropogenic and biological sources of carbonaceous aerosols in Northeast Asia,we measured total carbon(TC)and water-soluble organic carbon(WSOC)and their stable carbon isotope ratios(d^(13)C)in total suspended particulates collected from Sapporo,northern Japan(43.07°N,141.36°E)over a 1-year period(during 2 September 2009and 5 October 2010).Temporal variations of TC showed a gradual decrease from mid-autumn to winter followed by a gradual increase to growing season with a peak in early summer.Both d^(13)C_(TC)and d^(13)C_(WSOC)showed very similar temporal trends with a gradual enrichment of^(13)C from mid-autumn to winter followed by a depletion in the^(13)C to early summer and thereafter it remained stable,except for few cases.Based on the results obtained together with the air mass trajectories,we found that biogenic emissions including biological particles(e.g.,pollen)and secondary organic aerosol formation from biogenic volatile organic compounds are the important sources of carbonaceous aerosols in spring/summer whereas fungal spores from soil and biomass burning and enhanced fossil fuel combustion contribute significantly in autumn/winter and in winter,respectively,in Northeast Asia.

Multi-collector ICP-MS Analysis of Pb Isotope Ratios in Rocks: Data, Procedure and Caution

The authors measured Pb isotope compositions of seven USGS rock referencestandards, i.e. AGV-1, AGV-2, BHVO-1, BHVO-2, BCR-2, BIR-1/1 and W-2, together with NBS 981 using amicromass isoprobe multi-collector inductively-coupled plasma mass spectrometer (MC-ICP-MS) at theUniversity of Queensland. ^(203)Tl-^(205)Tl isotopes were used as an internal standard to correctfor mass-dependant isotopic fractionation. The results for both NBS 981 and USGS rock standardsAGV-1 and BHVO-1 are comparable to or better than double- and triple-spike TIMS (thermal ionizationmass spectrometry) data in precision. The data for BHVO-2 and, to a lesser extent, AGV-2 and BCR-2are reproducibly higher for ^(206)Pb/^(204)Pb, ^(207)Pb/^(204)Pb and ^(208)Pb/^(204)Pb thandouble-spike TIMS data in the literature. The authors also obtained the Pb isotope data for BIR- 1/1and W-2, which may be used as reference values in future studies. It is found that linearcorrection for Pb isotopic fractionation is adequate with the results identical to those correctedfollowing an exponential law or a power law. Precise ^(207)Pb/^(206)Pb, ^(208)Pb/^(206)Pb and^(208)Pb/^(207)Pb ratios can be acquired for sample solutions with Pb>=1 ppb. However, Pb isotoperatios involving ^(204)Pb (i.e., ^(206)Pb/^(204)Pb, ^(207)Pb/^(204)Pb and ^(208)Pb/^(204)Pb) arereliable for solutions with Pb>=40 ppb. The errors for Pb isotope ratio analysis using the MC-ICP-MSare dominated by errors in the analysis of ^(204)Pb, which is commonly ascribed to the difficultyand imprecise correction for a ^(204)Hg isobaric interference. It is found however that the majorerrors on ^(204)Pb come from the tailings of mass ^(203)Tl and mass ^(205)Tl These mass tailingslead to over-subtraction of the baseline for ^(204)Pb, which is measured at +-0.5 amu on both sidesof mass-204 (i.e., at amu 203.5 and 204.5 respectively). Such errors are insignificant for Pb-richsample solutions (i.e., high Pb/Tl ratios), but can be severe for low-Pb sample solutions whenover-'spiked' with Tl. Experiments in this study suggest that a minimum concentration ratio ofPb/Tl>5 in Tl-'spiked' solutions be required to ensure reliable ^(206)Pb/^(204)Pb, ^(207)Pb/^(204)Pband ^(208)Pb/^(204)Pb isotopic ratios. The tailings of ^(203)Tl and ^(205)Tl can also lead toover-subtraction of baselines for ^(202)Hg (at amu 202.5) and ^(206)Pb (at amu 205.5). Therefore,the elegance of using ^(203)Tl and ^(205)Tl isotopes for mass fractionation correction becomes asevere problem in low-Pb rock solution-caution is required. Alternative internal standards for massfractionation correction may be considered. Of course, significant instrumental refinement inabundance sensitivity is in demand.

Extraordinary transmission and reflection in PT-symmetric two-segment-connected triangular optical waveguide networks with perfect and broken integer waveguide length ratios

By adjusting the waveguide length ratio, we study the extraordinary characteristics of electromagnetic waves propagating in one-dimensional(1D) parity-time-symmetric(PT-symmetric) two-segment-connected triangular optical waveguide networks with perfect and broken integer waveguide length ratios respectively. It is found that the number and the corresponding frequencies of the extremum spontaneous PT-symmetric breaking points are dependent on the waveguide length ratio. Near the extremum breaking points, ultrastrong extraordinary transmissions are created and the maximal can arrive at, respectively, 2.4079 × 10^14 and 4.3555 × 10^13 in both kinds of networks. However, bidirectional invisibility can only be produced by the networks with broken integer waveguide length ratio, whose mechanism is explained in detail from the perspective of photonic band structure. The findings of this work can be useful optical characteristic control in the fabrication of PT-symmetric optical waveguide networks, which possesses great potential in designing optical amplifiers,optical energy saver devices, and special optical filters.

The population structure and sex ratios of Bursaphelenchus xylophilus under a-pinene stress

Pine wood nematode(PWN), Bursaphelenchus xylophilus, is a serious pathogen of pines throughout the world. Previous work indicated that different concentrations of a-pinene could affect nematode reproduction,however the mechanism of that influence is not clear. In order to examine the reproductive strategies of PWN in response to the stress of the volatile material a-pinene, we investigated different aspects of population changes of B.xylophilus under two concentrations of a-pinene. The results show that a high concentration(214.5 mg ml-1)promoted population growth while a low concentration(56.33 mg ml-1) decreased the population. Population structure was analyzed and it was found that a high concentration of a-pinene decreased the percentage of adults but increased the percentages of larvae and eggs.Furthermore, from the results of an evaluation of sex ratios(female/male), it was determined that a high concentration could elevate sex ratios but a low concentration decreased ratios sharply. These results suggest that the PWN could regulate its population by changing sex ratios under stress of a-pinene. This study has provided a theoretical basis for the prevention and control of pine wilt disease caused by the pine wood nematode.