^(15)N isotope fractionation in an aquatic food chain:Bellamya aeruginosa(Reeve) as an algal control agent

^ 15N isotope tracer techniques and ecological modeling were adopted to investigate the fractionation of nitrogen, its uptake and transformation in algae and snail （Bellamya aeruginosa Reeve）. Different algal species were found to differ in their uptake of nitrogen isotopes. Microcystis aeruginisa Ktitz. demonstrated the greatest ^15N accumulation capacity, with the natural variation in isotopic ratio （δ^15N） and the isotope fractionation factor （ε,‰） being the highest among the species investigated. The transformation and utilization of ^15N by snails differed depending on the specific algae consumed （highest for Chlorella pyrenoidosa Chick., lowest for M. aeruginisa）. When snails was seeded in the experimental pond, the algae population structure changed significantly, and total algal biomass as well as the concentration of all nitrogen species decreased, causing an increase in water transparency. A model, incorporating several chemical and biological parameters, was developed to predict algal biomass in an aquatic system when snails was present. The data collected during this investigation indicated that the gastropods such as snails could significantly impact biological community and water quality of small water bodies, suggesting a role for biological control of noxious algal blooms associated with eutrophication.

Superconductivity and Normal-State Properties of Kagome Metal RbV_(3)Sb_(5) Single Crystals

We report the discovery of superconductivity and detailed normal-state physical properties of RbV_(3)Sb_(5) single crystals with V kagome lattice.RbV_(3)Sb_(5) single crystals show a superconducting transition at Tc~0.92 K.Meanwhile,resistivity,magnetization and heat capacity measurements indicate that it exhibits anomalies of properties at T*~102-103 K,possibly related to the formation of charge ordering state.When T is lower than T*,the Hall coefficient RH undergoes a drastic change and sign reversal from negative to positive,which can be partially explained by the enhanced mobility of hole-type carriers.In addition,the results of quantum oscillations show that there are some very small Fermi surfaces with low effective mass,consistent with the existence of multiple highly dispersive Dirac band near the Fermi energy level.

Effect of Jianpi Bushen formula for colon cancer patients who underwent adjuvant chemotherapy:Statistical analysis plan for a multicenter trial

Background:Patients with colon cancer who receive chemotherapy usually experience various gastrointestinal adverse reactions,including nausea,vomiting,and diarrhea,which make it challenging for them to adhere to treatment.As an effective traditional Chinese medicine,the Jianpi Bushen formula has been widely used to alleviate the side effects of chemotherapy.Objective:To evaluate the efficacy and safety of Jianpi Bushen formulae for patients who undergo chemotherapy.This statistical analysis plan(SAP)is intended to enhance the transparency and research quality of our randomized controlled trial.Methods:Our study is a multicenter,double-blind,randomized controlled clinical trial.This trial aimed to compare the completion rate of chemotherapy in colon cancer patients who are using and not using Jianpi Bushen formula.To attenuate possible selection bias in the final report,we declared the overall trial design,outcome measures,subgroup analyses,and safety measures.Also,we described the data management and statistical analysis methods in detail.Conclusion:The SAP provides more detailed information than the trial protocol for data management and statistical analysis methods.Further post-hoc analyses can be performed by referring to the SAP,and possible selection bias can be attenuated.

Pressure-Induced Superconductivity in Flat-Band Kagome Compounds Pd_(3)P_(2)(S_(1−x)Se_(x))_(8)

We performed high-pressure transport studies on the flat-band Kagome compounds,Pd_(3)P_(2)(S_(1−x)Se_(x))_(8)(x=0,0.25),with a diamond anvil cell.For both compounds,the resistivity exhibits an insulating behavior with pressure up to 17GPa.With pressure above 20GPa,a metallic behavior is observed at high temperatures in Pd_(3)P_(2)S_(8),and superconductivity emerges at low temperatures.The onset temperature of superconducting transition T_(C) rises monotonically from 2K to 4.8K and does not saturate with pressure up to 43GPa.For the Se-doped compound Pd_(3)P_(2)(S_(0.75)Se_(0.25))_(8),the T_(C) is about 1.5K higher than that of the undoped one over the whole pressure range,and reaches 6.4K at 43GPa.The upper critical field with field applied along the c axis at typical pressures is about 50%of the Pauli limit,suggesting a 3D superconductivity.The Hall coefficient in the metallic phase is low and exhibits a peaked behavior at about 30 K,which suggests either a multi-band electronic structure or an electron correlation effect in the system.

Developments and Applications of Tunneling Magnetoresistance Sensors

Magnetic sensors based on tunneling magnetoresistance(TMR)effect exhibit high sensitivity,small size,and low power consumption.They have gained a lot of attention and have potential applications in various domains.This study first introduces the development history and basic principles of TMR sensors.Then,a comprehensive description of TMR sensors linearization and Wheatstone bridge configuration is presented.Two key performance parameters,the field sensitivity and noise mechanisms,are considered.Finally,the emerging applications of TMR sensors are discussed.

Frustrated ferromagnetic transition in AB-stacked honeycomb bilayer

In two-dimensional(2D) ferromagnets, anisotropy is essential for the magnetic ordering as dictated by the Mermin-Wagner theorem. But when competing anisotropies are present, the phase transition becomes nontrivial. Here, utilizing highly sensitive susceptometry of scanning superconducting quantum interference device microscopy, we probe the spin correlations of ABC-stacked Cr Br3under zero magnetic field. We identify a plateau feature in susceptibility above the critical temperature(TC) in thick samples.It signifies a crossover regime induced by the competition between easy-plane intralayer exchange anisotropy versus uniaxial interlayer anisotropy. The evolution of the critical behavior from the bulk to 2D shows that the competition between the anisotropies is magnified in the reduced dimension. It leads to a strongly frustrated ferromagnetic transition in the bilayer with fluctuation on the order of TC, which is distinct from both the monolayer and the bulk. Our observation demonstrates unconventional 2D critical behavior on a honeycomb lattice.

Applying a new method for direct collection, volume quantification and determination of N_2 emission from water

The emission of N2 is important to remove excess N from lakes, ponds, and wetlands. To investigate the gas emission from water, Gao et al.（2013） developed a new method using a bubble trap device to collect gas samples from waters. However, the determination accuracy of sampling volume and gas component concentration was still debatable. In this study, the method was optimized for in situ sampling, accurate volume measurement and direct injection to a gas chromatograph for the analysis of N2 and other gases. By the optimized new method, the recovery rate for N2 was 100.28% on average; the mean coefficient of determination（R2） was 0.9997; the limit of detection was 0.02%. We further assessed the effects of the new method, bottle full of water, vs. vacuum bag and vacuum vial methods, on variations of N2 concentration as influenced by sample storage times of 1,2, 3, 5, and 7 days at constant temperature of 15°C, using indices of averaged relative peak area（%） in comparison with the averaged relative peak area of each method at 0 day.The indices of the bottle full of water method were the lowest（99.5%–108.5%） compared to the indices of vacuum bag and vacuum vial methods（119%–217%）. Meanwhile, the gas chromatograph determination of other gas components（O2, CH4, and N2O） was also accurate. The new method was an alternative way to investigate N2 released from various kinds of aquatic ecosystems.

Magnetoresistance anomaly in Fe_(5)GeTe_(2)homo-junctions induced by its intrinsic transition

Two-dimensional van der Waals(2D vdW)magnets have attracted great attention recently and possess the unprecedented advantages of incorporating high-quality vdW heterostructures and homostructures into spintronic devices,and exploring various physical phenomena or technologies.Among them,Fe_(5)GeTe_(2)(F5GT)has ferromagnetic order close to room temperature,however the magnetic properties near its intrinsic transitions and F5GT-based 2D devices remain mostly unexplored.Here,we systematically demonstrate the peculiar magnetic properties of Fe_(5)GeTe_(2)nanoflakes near its intrinsic transition temperature(Tp)which is far lower than its Curie temperature(TC)of~265 K,and firstly discover anomalous magnetoresistance effect in F5GT homo-junctions by magneto-transport measurements.The strongest anomalous Hall effect occurs around Tp which is located in a temperature range from 130 to 160 K for the F5GT nanoflakes with different thicknesses.Furthermore,negative magnetoresistance(N-MR)and butterfly-shaped magnetoresistance(B-MR)are observed in F5GT homo-junction devices,and they appeared only in an intermediate temperature range from 110 to 160 K,noticeably showing the maxima near the T_(p)rather than the lowest temperature.Our experimental results clearly reveal the significant influence of intrinsic transitions on magnetic properties of F5GT and magnetoresistance effect in F5GT homo-junction devices,which imply a new strategy to achieve highperformance 2D spintronic devices by tuning intrinsic magnetic or structural transitions in 2D vdW magnets.