Study on the Rapid Method to Predict Longevity of Controlled Release Fertilizer Coated by Water Soluble Resin

The study discussed the rapid method to test and predict the longevity of controlled release fertilizers （CRFs） coated by water soluble resin by using the short-term leaching under higher temperature. Pure water dissolving incubation and higher temperature leaching were used to study the patterns of the nutrient release of the CRFs. The correlation analysis between the days at 25℃ and the hours at 80℃ of Trincote 1 and Trincote 2 for the same cumulative release rates were conducted. Patterns of cumulative nutrient release curve followed one factor quadratic regression equation at each given temperatures, and each of relative coefficient was bigger than 0.995. As the temperature increased, nutrients release of the CRFs increased. The longevity of resin coated CRFs were predicted by use of both the cumulative nutrients release equation at 80℃ and the regression equation of release time needed for the same cumulative release rates between 25 and 80℃. There were only 0.3-6.9% relative errors between the tested longevity and predicted one. In conclusion, the longevity of resin coated CRFs could be predicted more quickly and precisely by use of the higher temperature short-term leaching method than that of the traditional differential release rate. The longevity of resin coated CRF could be rapidly and precisely predicted in a few hours by application of the higher temperature shortterm leaching method.

A Rapid Method for Measuring Seed Protein Content in Cowpea (<i>Vigna unguiculata</i>(L.) Walp)

Cowpea (Vigna unguiculata (L.) Walp), a legume crop that is grown in the worldwide, provides beneficial proteins for human consumption and animal feeding. In comparison, Rapid N analyzer as traditional method, has been widely used to measure protein content through the percentage of total nitrogen in the seed’s grounded powder. Near-Infrared Reflectance (NIR) has commonly been used to measure protein content in soybean seeds using whole grain without the need of seed grinding, which makes it possible to obtain fast results at a lower cost-per-analysis than the traditional combustion method. The specific objective of this study is to test a rapid method for measuring cowpea seed protein content by the NIR analyzer comparing to the traditional rapid N analyzer. A total of 240 cowpea genotypes were used in this study, including six seed coat colors, black, blackeye, browneye, cream, pinkeye, and red with 40 cowpea genotypes. The results showed that a linear relationship exists between the NIR analyzer and the Rapid N analyzer in the six different color groups. The correlation efficiency (r) between the seed protein contents from NIR and Rapid N was higher for pinkeye seed (r = 0.867), blackeye (0.771), cream (0.729), browneye (0.700), and red (0.623), respectively, but lower for black seeds, indicating that the NIR analyzer can be used to measure protein content for cowpea seeds with the five types of seed coat except black. Overview, the cowpea seed protein content measured from the NIR analyzer showed a little higher seed protein content. A series of regression models with different seed coat color have been built to adjust to protein content of colorful cowpea seeds from the NIR analyzer. But, it is not recommended to use for black color seeds due to a very low correlation efficiency (r) value with 0.184.

A New Rapid and Batch-oriented Crushing Method for DNA Extraction from Maize Leaves

The crushing of leaves is the most time and effort-consuming part in DNA extraction which is a fundamental step in the study of molecular biology. In this study, a new rapid and batch-oriented crushing method for DNA extraction from maize leaves was developed. In addition, the practicability of the developed method in molecular marker-assisted breeding was verified using SSR molecular maker technology so as to provide a rapid, batch-oriented, low-cost and non-toxic leafcrushing method for a large number of molecular marker tests, improving test efficiency.

Rapid diagnostic method for transplutonium isotope production in high flux reactors

Transplutonium isotopes are scarce and need to be produced by irradiation in high flux reactors.However,their production is inefficient,and optimization studies are necessary.This study analyzes the physical nature of transplutonium isotope produc-tion using ^(252)Cf,^(244)Cm,^(242)Cm,and ^(238)Pu as examples.Traditional methods based on the Monte Carlo burnup calculation have the limitations of many calculations and cannot analyze the individual energy intervals in detail;thus,they cannot sup-port the refined evaluation,screening,and optimization of the irradiation schemes.After understanding the physical nature and simplifying the complexity of the production process,we propose a rapid diagnostic method for evaluating radiation schemes based on the concepts“single energy interval value(SEIV)”and“energy spectrum total value(ESTV)”.The rapid diagnostic method not only avoids tedious burnup calculations,but also provides a direction for optimization.The optimal irradiation schemes for producing ^(252)Cf,^(244)Cm,^(242)Cm,and ^(238)Pu are determined based on a rapid diagnostic method.Optimal irradiation schemes can significantly improve production efficiency.Compared with the initial scheme,the optimal scheme improved the production efficiency of ^(238)Pu by 7.41 times;^(242)Cm,11.98 times;^(244)Cm,65.20 times;and ^(252)Cf,15.08 times.Thus,a refined analysis of transplutonium isotope production is conducted and provides a theoretical basis for improving production efficiency.

Study on a noninvasive method for rapid screening Human Serum albumin injectables by Raman spectroscopy

Human serum albumin(HSA)injectable product is a severely afflicted area on drug safety due to its high price and restricted supply.Raman spectroscopy performances high specificity on HSA detection and it is even possible to determine HSA injectable products noninvasively.In this study,we developed a noninvasive rapid screening method for of HSA injectable products by using portable Raman spectrometer.Qualitative models were established by using principal component analysis combined with classical least squares(PCA-CLS)algorithm,while quanti-tative model was established by using partial least squares(PLS)algorithm.Model transfer in different instruments of both the same and different apparatus modules was further discussed in this paper.A total of 34 HSA injectable samples collected from markets were used for verification.The identification results showed 100%accuracy and the predicted concentrations of those identified as true HSA were consistent with their labeled concentrations.The quantitative results also indicated that model transfer was excellent in the same apparatus modules of Raman spectrometer at all concentration levels,and still good enough in the different apparatus modules although the relative standard deviation(RSD)value showed a little increasing trend at low HSA concentration level.In conclusion,the method was proved to be feasible and efficient for screening HSA injections,especially on its screening speed and the consideration of glass containers.Moreover,with inspiring results on the model transfer,the method could be used as a universal screening mean to different Raman instruments.

Tire Dynamics Modeling Method Based on Rapid Test Method

Combined with the tire dynamics theoretical model,a rapid test method to obtain tire lateral and longitudinal both steady-state and transient characteristics only based on the tire quasi-steady-state test results is proposed.For steady state data extraction,the test time of the rapid test method is half that of the conventional test method.For transient tire characteristics the rapid test method omits the traditional tire test totally.At the mean time the accuracy of the two method is much closed.The rapid test method is explained theoretically and the test process is designed.The key parameters of tire are extracted and the comparison is made between rapid test and traditional test method.The result show that the identification accuracy based on the rapid test method is almost equal to the accuracy of the conventional one.Then,the heat generated during the rapid test method and that generated during the conventional test are calculated separately.The comparison shows that the heat generated during the rapid test is much smaller than the heat generated during the conventional test process.This benefits to the reduction of tire wear and the consistency of test results.Finally,it can be concluded that the fast test method can efficiently,accurately and energy-efficiently measure the steady-state and transient characteristics of the tire.

Dengue virus infection:A review of advances in the emerging rapid detection methods

Dengue virus infections are increasing worldwide generally and in Asia,Central and South America and Africa,particularly.It poses a serious threat to the children population.The rapid and accurate diagnostic systems are essentially required due to lack of effective vaccine against dengue virus and the progressive spread of the dengue virus infection.The recent progress in developing micro-and nano-fabrication techniques has led to low cost and scale down the biomedical point-of-care devices.Starting from the conventional and modern available methods for the diagnosis of dengue infection,this review examines several emerging rapid and point-of-care diagnostic devices that hold significant potential for the progress in smart diagnosis tools.The given review revealed that an effective vaccine is required urgently against all the dengue virus serotypes.However,the rapid detection methods of dengue virus help in early treatment and significantly reduce the dengue virus outbreak.

Research on a Rapid Test Method of Dry Basis Weight of Paper-process Reconstituted Tobacco

This study aimed to optimize the rapid test factors of dry basis weight of reconstituted tobacco, in order to afford a reference test method for companies which produce reconstituted tobacco to better control the basis weight and coating ratio on line. The dry basis weight of reconstituted tobacco was tested by fast method and normal oven method individually. And the effects on the test values of different test factors such as temperature, time and the number of baking sheets were studied. Then the test values of these two methods were compared, so the proper factors of rapid test method were determined. As the baking temperature rose from 130 ℃ to 150 ℃, and the baking time rose from 1 min to 2 min, the difference between fast test method and normal oven method grew, and when the number of baking pieces rose from 3 pieces to 5 pieces, the difference between the two methods went down. The optimum test condition was baking temperature of 130 ℃, baking time of 1 min, and baking sample sheet number of 5. Under this condition, the value of fast test method was the closest to the test value of normal oven method, and meanwhile, the test factor was more proper for testing on line. The study will provide a reference for online controlling of dry basis weight and coating ratio of reconstituted tobacco.

Introducing a Rapid and Safe Method for Myeloperoxidase Staining

Background: Myeloperoxidase staining is used to differentiate leukemias since several decades. Despite implementation of flow cytometric, cytogenetic and molecular techniques for identification of leukemic blasts, histochemical stains such as myeloperoxidase stain are persistently used for better classification of leukemias. The myeloperoxidase staining is a time consuming and hazardous procedure. The present report describes a sensitive, rapid and easy method for assessment of peroxidase activity. Materials and Methods: Bone marrow aspiration slides were stained with Dako product: Code number: K3467 containing DAB chromogen (3,3-diaminobenzidine in chromogen solution) and substrate buffer (Imidasole-HCL buffer, PH 7.5 containing hydrogen peroxide and an anti microbial agent) in a rapid procedure taking only ten minutes time. The staining needs no material preparation steps. Neutrophils in the slide are taken as positive control or another normal smear was costained to be used as control. All cases were followed up with flow cytometry and cytogenetic studies. Result: The reaction product of this stain is brown and granular. Promyelocytes and myelocytes are the most strongly staining cells with positive (primary) granules. Lymphoblasts are negative. The result of classification of leukemias with this technique was in concordance with flow cytometric immunophenotyping. Discussion: Many practical techniques have been described using benzidine as an indicator for myeloperoxidase staining. Benzidine is a carcinogenic material and its usage is severely restricted in laboratory. Formerly we prepared requisite materials for myeloperoxidase staining by hazardous ways (boiling), but we decided to apply ready to use 3,3-diaminobenzidine (DAB), which is used in final step of immunohistochemistry stains. Conclusion: Use of 3,3-diaminobenzidine (DAB) is highly recommended for myeloperoxidase staining, while the result is extraordinary and fully compatible with flow cytometry and the method is safe and rapid.

Enzyme Inhibition Rate Method for Rapid Detection of Organophosphorus and Carbamate Pesticides in Cowpea

[Objectives ] The paper was to explore enzyme inhibition rate method for rapid detection of organophosphorus and carbamate pesticides in cowpea. [ Methods ] Acetylcholinesterase （ACHE） was added to cowpea extract, to determine the inhibition rate of extract against enzyme. The influences of different sampiing methods and sampling parts on detection results were compared. [ Results] The positive rate of standard sampling was 18.18% higher than that of non-stand- ard sampling, and the positive rate of samples collected from cowpea tail was 16.67% higher than that collected from other parts. [ Condmions] Enzyme inhibi- tion rate method is suitable for rapid detection of organophosphorus and carbamate pesticides in cowpea.

A Method for Rapid Determination of Polymer Dissolution Time

In view of the limited space of offshore platform and the large amount of polymer injection, the dissolution time method, solution viscosity method, conductivity method, undissolved filtration method and falling ball method are used as the rapid detection methods of polymer dissolution. The results show that the error of conductivity method is the largest, and that of dissolution time method is the second, and both methods are time-consuming. Solution viscosity method and insolubles filtration method have small error, but they are time-consuming, especially for offshore platforms, which makes detection inconvenient. The drop ball method is simple in operation and has a small error, so it is a promising method for rapid determination of polymer dissolution time.

单核细胞增生李斯特氏菌Rapid’L.mono快速筛选方法的评价

目的对单核细胞增生李斯特氏菌Rapid’L.mono快速筛选方法进行评价。方法以国家标准GB4789.30-2016作为参照方法,在检测特异性、交叉反应试验、添加实验、不同批次产品培养条件的影响和实际样品的检测方面对Rapid’L.mono快速筛选方法进行比较和评价。结果 Rapid’L.mono快速筛选培养基准确率达到97%,与30株非目标菌无交叉反应。GB 4789.30-2016方法的检出率高于快速筛选方法,2种方法的检测差异存在统计学意义(χ~2=15.864,P<0.05)。培养温度和培养时间的变化对Rapid’L.mono快速筛选方法的检出率没有影响。230份样品中,GB 4789.30-2016方法和Rapid’L.mono快速筛选方法均未检测到阳性结果样品。结论 Rapid’L.mono快速筛选培养基可以作为一种选择性培养基来使用,Rapid’L.mono快速筛选方法可以辅助国标方法应用于食品检测中。

基于二氧化铈/羟基氧化铁纳米酶的比色分析法快速检测泡椒凤爪中过氧化氢

采用水热法合成二氧化铈(CeO_(2))修饰的羟基氧化铁(FeOOH),得到纳米材料CeO_(2)/FeOOH。CeO_(2)/FeOOH具有类过氧化物酶活性,可以催化过氧化氢(H_(2)O_(2))分解产生羟自由基(·OH)和超氧阴离子自由基(O2-·),将3,3’,5,5’-四甲基联苯胺(3,3’,5,5’-tetramethylbenzidine,TMB)氧化为蓝色的氧化TMB(oxidized TMB,ox-TMB)。基于此,构建基于CeO_(2)/FeOOH纳米酶的H_(2)O_(2)比色传感器。结果表明:该比色传感器对H_(2)O_(2)显示出高灵敏度响应,检测限为3.92μmol/L,检测范围为10~1000μmol/L。此外,该传感器可用于泡椒凤爪中H_(2)O_(2)的快速检测,其中,H_(2)O_(2)加标回收率为90.59%~93.42%,相对标准偏差≤4.25%,具有灵敏、准确、快速和简便等优势。

Effect of rapidly depressurizing and rising temperature on methane hydrate dissociation

Two methods, rapidly depressurizing to 0.1 MPa at a constant temperature and rising temperature under equilibrium P, T conditions, were used to study the dissociation of pure CH4 hydrate formed below the ice point. At a constant temperature with rapidly depressurizing to 0.1 MPa, CH4 hydrate dissociated rapidly at initial dissociation and then the dissociation rate gradually decreased. However, the dissociation of CH4 hydrate at temperatures of 261 to 266 K was much faster than that at temperatures of 269 to 272 K, indicating its anomalous preservation. Under an equilibrium P, T conditions, rising temperature had extensively controlling impact on dissociation of CH4 hydrate at equilibrium pressures of 2.31, 2.16 and 1.96 MPa. In this study, we report the effect of pressure on CH4 hydrate dissociation, especially the effect of equilibrium pressure on dissociation at various melting temperatures. And we find that the ice particles size of CH4 hydrate formed may dominant the CH4 hydrate dissociation. Dissociation of CH4 hydrate formed from ice particles of smaller than 250 μm may not have an anomalous preservation below the ice point, while particles larger than 250 μm may have more extensive anomalous preservation.

Rapid Screening of 82 Pesticide Residues in Feed by Liquid Chromatography Coupled with Quadrupole-Time of Flight Mass Spectrometry

[Objectives]This study was conducted to establish a qualitative method for rapid detection of pesticide residues in feed.[Methods]A rapid screening method for 82 pesticide residues in feed was established using ultra liquid chromatography coupled with quadrupole-time of flight mass spectrometry(UPLC-Q-TOF-MS)combined with optimized pretreatment methods.[Results]Feed samples were extracted with 0.2%formic acid-acetonitrile solution,shaken,centrifuged,and re-centrifuged,and the supernatant was filtered with a 0.22μm filter membrane for determination.The samples were separated on a Waters ACQUITY UPLC HSS T3 chromatographic column(2.1 mm×50 mm,1.8μm),and subjected to gradient elution with methanol-water solution as the mobile phase,and scanning was performed in ESI+mode.82 compounds could be accurately qualitatively detected in 13 min.[Conclusions]This method is simple to operate,time-saving,and can be applied to rapid screening of large-scale feed.This study provides a theoretical basis for the development of new methods in the future.

Establishment of a Loop-mediated Isothermal Amplification Method for Rice Bacterial Leaf Brown Spot Disease

Rice bacterial leaf brown spot disease caused by Pseudomonas syringae pv.syringae(Pss)is a major disease on rice.In recent years,Pss has emerged worldwide,seriously affecting rice production.It is very important to establish a rapid detection method of Pss for the diagnosis and prevention of this disease.In order to robust and accurately diagnose the rice bacterial leaf brown spot disease in the field and laboratory,an assay system for the Pss was developed in this study,and the specific sequence of hrcN was used as the target,based on loop-mediated isothermal amplification(LAMP).The best detection system was MgSO 48 mmol·L^(-1),Bst DNA polymerase 8 U,dNTP 1.4 mmol·L^(-1),the ratio of internal and outer primers was 2:1,the reaction temperature was 63℃,the reaction time was 45 min,and the lowest sensitivity was 104 CFU·mL^(-1).This results provided an accurate and robust method for laboratory and field diagnosis of bacterial leaf brown spot disease of rice.

国内外食品快速检测方法评价技术研究

相比于国外成熟的快速检测方法评价技术体系,我国的评价技术体系发展滞后且有较多问题,严重制约了快检行业的发展。本文主要从验证方法、性能指标、测试要求等方面对各个评价技术体系做了对比分析。同时梳理了国内不同监管部门的评价技术体系发展与侧重,以期为我国食品快速检测方法确认政策和技术研究提供良好的借鉴,引导食品快速检测方法及产品的评价标准进一步规范,形成完善的科学评价方法和评价技术体系,促进我国食品安全及快速检测行业的健康发展。

Magnetic Properties of NiCuZn Ferrite Thin Films Prepared by the Sol-gel Method

Ni0.4Cu0.2Zn0.4Fe2O4 thin films were fabricated on Si substrates by using the sol-gel method and rapid thermal annealing （RTA）, and their magnetic properties and crystalline structures were investigated. The samples calcined at and above 600 ℃ have a single-phase spinel structure and the average grain size of the sample calcined at 600 ℃ is about 20 nm. The initial permeability μi, saturation magnetization M and coercivity H of the samples increase with the increasing calcination temperature. The sample calcined at 600 ℃ exhibits an excellent soft magnetic performance, which has μi=33.97 （10 MHz）, Hc=15.62 Oe and Ms=228.877 emu/cm^3. Low-temperature annealing can enhance the magnetic properties of the samples. The work shows that using the sol-gel method in conjunction with RTA is a promising way to fabricate integrated thin-film devices.

Flow field simulation of the thin metal ribbon formed by twin-belt rapid solidification

The flow field formed when an aluminum ribbon is produced by twin-belt rapid solidification is simulated with the solution algorithm （SOLA）-volume of fluid （VOF） method, and the influence of casting speed and cooling-belt velocity on the flow field is analyzed for a given ejection nozzle size. It has been found that the flow field can be filled well when the width of the ejection nozzle outlet is the same as that of the up slit of the cooling belt. When the ejection nozzle outlet is wider than the up slit of the cooling belt, the aluminum fluid can fill well if only the casting speed matches the cooling-belt velocity properly, otherwise under filling occurs in some areas in the cooling zone.