Temporal variation of soil carbon stock and its controlling factors over the last two decades on the southern Song-nen Plain,Heilongjiang Province

Against the current background of global climate change, the study of variations in the soil carbon pool and its controlling factors may aid in the evaluation of soil＇s role in the mitigation or enhancement of greenhouse gas. This paper studies spatial and temporal variation in the soil carbon pool and their controlling factors in the southern Song-nen Plain in Heilongjiang Province, using soil data collected over two distinct periods by the Multi-purpose Regional Geochemical Survey in 2005-2007, and another soil survey conducted in 1982-1990. The study area is a carbon source of 1479 t/km2 and in the past 20 years, from the 1980s until 2005, the practical carbon emission from the soil was 0.12 Gt. Temperature, which has been found to be linearly correlated to soil organic carbon, is the domi- nant climatologic factor controlling soil organic carbon contents. Our study shows that in the relevant area and time period the potential loss of soil organic carbon caused by rising temperatures was 0.10 Gt, the potential soil carbon emission resulting from land-use change was 0.09 Gt, and the combined potential loss of soil carbon （0.19 Gt） caused by warming and land-use change is comparable to that of fossil fuel combustion （0.21 Gt）. Due to the time delay in soil carbon pool variation, there is still 0.07 Gt in the potential emission caused by warming and land-use change that will be gradually released in the future.

Coupling changes of soil functional gene abundances and extracellular enzyme activities across the diagnostic horizons of agricultural Isohumosols

Soil functional microbial taxa and extracellular enzymes are involved in a variety of biogeochemical cycling processes.Although many studies have revealed the vertical change patterns of microbial communities along soil profile,the general understanding of the coupling changes in the functional gene abundances(FGAs)and extracellular enzyme activities(EEAs)in soil profiles is still limited,which hinders us from revealing soil ecosystem processes.Herein,we comparatively investigated the FGAs and EEAs in the diagnostic A,B,and C horizons of soil profiles obtained from two suborders of Isohumosols(Mollisols),Ustic and Udic Isohumosols,in Northeast China based on quantitative real-time polymerase chain reaction and standard fluorometric techniques,respectively.The distribution patterns of both FGAs and EEAs significantly distinguished by the two soil suborders and were also separated from A to C horizon.Additionally,the variations of EEAs and FGAs were greater in Udic Isohumosols compared to Ustic Isohumosols along soil profiles,and greater changes were observed in C horizon than in A horizon.Both FGAs and EEAs correspondently decreased along the soil profiles.However,when normalized by soil organic carbon,the specific EEAs significantly increased in deep soil horizons,suggesting that microorganisms will input more resources to the production of enzymes to ensure microbial nutrient requirements under resource scarcity.More importantly,we revealed that soil microbial nutrient demands were limited by carbon(C)and phosphorus(P),and the C and P limitations significantly increased along soil profiles with a greater C limitation observed in Ustic Isohumosols than in Udic Isohumosols.Overall,our findings provided solid evidence showing the links between FGAs,EEAs,and microbial nutrient limitations,which would be helpful for a better understanding of the ecosystem processes in soil profiles.

CH_4-CO_2 reforming to syngas over Pt-CeO_2-ZrO_2/MgO catalysts: Modification of support using ion exchange resin method

Pt-CeO2-ZrO2/MgO （Pt-CZ/MgO） catalysts with 0.8 wt% Pt, 3.0 wt% CeO2 and 3.0 wt% ZrO2 were prepared by wet impregnation method. Support MgO was obtained using ion exchange resin method or using commercial MgO. XRD, BET, SEM, TEM, DTA-TG and CO2-TPD were used to characterize the catalysts. CH4-CO2 reforming to synthesis gas （syngas） was performed to test the catalytic behavior of the catalysts. The catalyst Pt-CZ/MgO-IE（D） prepared using ion exchange resin exhibits more regular structure, smaller and more unique particle sizes, and stronger basicity than the catalyst Pt-CZ/MgO prepared from commercial MgO. At 1073 K and atmospheric pressure, Pt-CZ/MgO-IE（D） catalyst has a higher activity and greater stability than Pt-CZ/MgO catalyst for CH4-CO2 reforming reaction at high gas hourly space velocity of 36000 mL/（g.h） with a stoichiometric feed of CH4 and C02. Activity measurement and characterization results demonstrate that modification of the support using ion exchange resin method can promote the surface structural property and stability, therefore enhancing the activity and stability for CH4-CO2 reforming reaction.

Efficacy and safety of rasagiline in Chinese patients with early Parkinson’s disease:a randomized, double-blind,parallel,placebo-controlled,fixed-dose study

Background:Rasagiline is a monoamine oxidase-B inhibitor used for Parkinson’s disease(PD)treatment,but its effectiveness on Chinese patients is unclear.This study aimed to evaluate the efficacy and safety of rasagiline monotherapy in Chinese patients with early PD.Methods:A 26-weeks,randomized,double-blind,placebo-controlled study has been performed at 15 sites in China and enrolled outpatients(≥35 years old)with idiopathic PD without a history of using any dopaminergic drugs.Participants were randomized 1:1 to receive rasagiline 1 mg once daily or placebo.The primary endpoint was the change of the Unified Parkinson’s Disease Rating Scale(UPDRS)total score from baseline to 26 weeks treatment.Secondary endpoints included changes in UPDRS subscale scores from part Ⅰ to Ⅲ.Health status was assessed with the PD Questionnaire(PDQ)-39 and EuroQol-Five-Dimension(EQ-5D)questionnaire.Safety profile was collected until 30 weeks after randomization.Results:A total of 130 patients(n=65/group)were recruited,and 127(rasagiline,n=64;placebo,n=63)were included in the full analysis set.Baseline characteristics were comparable between the two groups.The decrease in the mean UPDRS total score was greater in the rasagiline group than in the placebo group(−3.18±0.95 vs.−0.18±0.98,P=0.025),and the mean UPDRS part I non-motor symptoms score(−0.54±0.15 vs.-0.08±0.15,P=0.003)were significantly decreased in the rasagiline group compared with placebo treated patients.An improvement trend was observed in the active treatment group for the subscales evaluation with parts Ⅱ and Ⅲ,while the difference to placebo was not statistically significant.Life quality assessed by the EQ-5D visual analog scale improved in the rasagiline group but worsened in placebo treated patients.The overall incidence of treatment-emergent adverse events(AEs)was slightly lower in the rasagiline group(41.5%)than in the placebo group(46.2%).Conclusions:Rasagiline is effective,safe,and well tolerated as monotherapy for the treatment of Chinese PD patients.

A new regeneration approach to cation resins with aluminum salts： application of desalination by its mixed bed

A novel method for the regeneration of cation exchange resins by aluminum （A1） salts was investigated in order to improve the regeneration efficiency of resins and reduce the dosage of regenerant. The influences of AP＋ concentration and the pH of regeneration solution on resin transformation had been studied. The desalination experi- ments were carried out to evaluate the characteristics of the A1 form resins. Experimental results showed that the regeneration rate of resins was strictly dependent on AP＋ concentration and the pH of the solution. Compared to the conventional regeneration method, the Al form mixed bed exhibited the same desalination capability as the H form mixed bed （MB）, and the total organic carbon （TOC） removal was up to 90%, clearly higher than that of the H form. Al salt solution could be utilized repeatedly to regenerate Al form resins.

Nutritional quality of different potassium efficiency types of vegetable soybean as affected by potassium nutrition

Pot experiments were conducted in 2017,2019,and 2020 to examine the effects of potassium nutrition on the nutritional components of vege-table soybeans with different K efficiency at immature and mature stages.Two vegetable soybean varieties with higher K efficiency and two varieties with lower K efficiency were studied in the low available K soil under the conditions of no K and normal K fertilization.The results indicated that almost all nutritional components in vegetable soybean were affected by K,genotypes,interannual differences,and their inter-actions.In general,no K fertilization increased protein and amino acid concentrations but decreased oil,soluble sugar,sucrose,K,Mg,and Fe concentrations in immature and mature vegetable soybean.The sensitivity of nutritional components to K nutrition differed among varieties.For instance,K high-efficiency varieties generally exhibited higher protein and amino acid concentrations without K application.K high-efficiency vegetable soybeans are low-K tolerance varieties to isoflavones.The results of this study provide insights for high yield and quality vegetable soybean breeding against soil K deficiency.

Adjunct rasagiline to treat Parkinson’s disease with motor fluctuations:a randomized,double-blind study in China

Background:The use of adjunct rasagiline in levodopa-treated patients with Parkinson’s disease and motor fluctuations is supported by findings from large-scale clinical studies.This study is to investigate the efficacy and safety of adjunct rasagiline in Chinese patients with Parkinson’s disease,as a product registration study.Methods:This 16-week,randomized,double-blind,parallel-group,multicenter,placebo-controlled study of rasagiline 1 mg/day included levodopa-treated patients with Parkinson’s disease and motor fluctuations.The primary efficacy endpoint was mean change from baseline in total daily OFF time over 16 weeks.Secondary endpoints were Clinical Global Impressions–Improvement(CGI-I),and change in Unified Parkinson’s Disease Rating Scale(UPDRS)Activities of daily living(ADL)and Motor scores.Patient well-being(EQ-5D),and the frequency of adverse events were also assessed.Results:In total,324 levodopa-treated patients were randomized to rasagiline 1 mg/day(n=165)or placebo(n=159).Over 16 weeks,rasagiline statistically significantly reduced the mean[95% confidence interval]total daily OFF time versus placebo(−0.5 h[−0.92,−0.07];p=0.023).There were also statistically significant improvements versus placebo in CGI-I(−0.4 points[−0.61,−0.22];p<0.001),UPDRS-ADL OFF(−1.0 points[−1.75,−0.27];p=0.008),and UPDRS-Motor ON(−1.6 points[−3.05,−0.14];p=0.032)scores,as well as the EQ-5D utility index(p<0.05).Rasagiline was safe and well tolerated.Conclusions:In levodopa-treated Chinese patients with Parkinson’s disease and motor fluctuations,adjunct rasagiline 1 mg/day statistically significantly reduced OFF time,and improved daily function and overall well-being,versus placebo.Consistent with findings in other countries,adjunct rasagiline was proven efficacious and well tolerated in Chinese patients.

居家诊断心肌梗死:基于适体的cTnI传感技术

心肌肌钙蛋白I(cTnI)是与急性心肌梗死(AMI)密切相关的生物标志物,被认为是诊断AMI的“金标准”。目前已有多种cTnI检测技术被开发,包括基于抗体和适体的检测方法。适体是一种能和靶标特异性结合的短的DNA或RNA序列,因其稳定性好、易合成和成本低等优点被用于cTnI检测平台的开发。本文根据信号转导方式,将cTnI检测法分为光学检测和电化学检测两大类,介绍了目前基于适体的cTnI传感技术研究进展,阐述了各类方法的检测原理、性能以及优缺点,对cTnI传感技术进行了总结并对其在居家检测中的发展进行了展望,希望为开发更灵敏、更便携的cTnI传感器提供借鉴和参考。

一种合页型纸基微流控芯片用于铅离子的裸眼定量检测

本文构建了一种结合DNA水凝胶的合页型纸基微流控芯片(HPMC),用于灵敏检测Pb^(2+).该芯片由DNA水凝胶敏感阀门和纸基毛细微通道两部分组成,水凝胶阀门在Pb^(2+)的作用下控制被测液进入毛细微通道的速度,通过肉眼读取被测液在一定时间内流过毛细微通道的距离,无需外接设备即可实现Pb^(2+)的定量检测.该HPMC能实现不同浓度(1~500 nmol/L)Pb^(2+)溶液的裸眼定量检测,检测限为0.3 nmol/L.通过对化妆品中Pb^(2+)的定量检测证明了该装置的实用性,为现场检测Pb^(2+)提供了一个快速、便携、灵敏和高选择性的可视化平台.

DNA水凝胶在生物传感中的应用和发展

脱氧核糖核酸(DNA)是一种重要的生物分子,具有许多独特的性质如:信息传递、分子识别、可编辑等。DNA水凝胶同时具有DNA分子和水凝胶材料的优势,并且可以引入其他纳米材料获得多功能杂化水凝胶。相比于传统水凝胶,DNA水凝胶具有良好的特异识别能力以及可以按需设计的性质,从而被广泛应用于生物传感领域。本文围绕DNA水凝胶的合成、响应机制以及在传感领域的应用进行综述。按照不同的合成方法可分为线性DNA链缠绕水凝胶、枝状DNA自组装水凝胶、杂合DNA水凝胶。根据传感机制的不同又可以分为包埋封装法和非包埋封装法,包埋封装发法又分为:酶的包埋释放、抗原-抗体的包埋释放、纳米材料的包埋释放。本文总结了近几年DNA水凝胶在重金属离子检测、核酸检测、葡萄糖检测、蛋白质和代谢小分子检测,以及细胞检测等热门领域的研究情况,最后对其未来的发展进行了展望。

Electro-assisted regeneration of ion exchange resins

Electro-assisted regeneration(EAR)for the mixed bed of strongly acidic cation and weakly basic anion exchange resins with the Al(OH)_(3) suspension in a three-compartment cell was investigated.The desalination experiments were carried out to evaluate the characteristic of the regenerated mixed resins.Experimental results showed that the efficiency of resin regeneration was strictly dependent on the voltage,regeneration time,and feed regenerant flow rate.The amount of the effluent reached 50 times the volume of the resins bed,and the conductivity was less than 1.0 ms/cm.Compared to the conventional ER,the total effluent volume of EAR was about 1000 mL more than that of ER under the same conditions,and the outlet conductivity was significantly lower.The desalination and regeneration reaction mechanisms of the mixed resins indicated the regeneration efficiency of resin with Al(OH)_(3) as the regenerant was much higher than that with H2O.