Simple Analytical Method Research Articles

Construction of Fluorescence Sensing Platform on the Basis of Molybdenum Disulfide Nanosheet for the Detection of AFB<sub>1</sub>

Purpose: Aflatoxin B1 is the most common mycotoxin in cereal crops; it is of stronger toxicity and has a carcinogenic effect. In recent years, a series of fluorescence sensors constructed on the basis of MoS2NS fluorescence quenching property have become a research hotspot. Therefore, we can construct a fast and simple analysis method with high specificity to detect AFB1 by utilizing MoS2NS, which can be effectively applied to food safety monitoring and clinical diagnosis. Method: In the current research, a fluorescence biosensor is developed on the basis of a new type of two-dimensional nano-material namely MoS2NS applied for the detection of AFB1. The fluorescence of Apt@AFB1 can be quickly quenched by MoS2NS through the fluorescence resonance energy transfer (FRET). When the target molecule AFB1 exists, after the specificity binding between AFB1 and aptamer, the Apt@AFB1 loses its single stranded structure and is away from MoS2NS, and the fluorescence of Apt®AFB1 cannot be quenched effectively. Such sensing signals can be used to achieve the sensitive detection of AFB1. Result: With this new method, under the optimized conditions, the AFB1 is analyzed in the MoS2NS/Apt®AFB1 sensing platform. Within the dynamic range of 0.2 - 25 ng/mL, the sensing platform expresses a good linear response to the level of AFB1 with the R2 = 0.9964 and LOD as 90 pg/mL. This method is applied to detect the actual serum samples and soybean milk with the recovery rate of 93.10% - 107.23% and 95.15% - 102.60% separately, and it can be used in the quantitative detection under the interference of other mycotoxins in a relatively accurate way. Conclusion: It is proved that this new detection method can be used as a potential biosensor platform for the detection of AFB1. This detection method features several advantages such as specificity, rapidness and low costs, which can meet the requirement of trace detection in clinical detection and food safety.

On the properties of residential rooftop azimuth and tilt uncertainties for photovoltaic power generation modeling and hosting capacity analysis

One of the essential epistemic uncertainties that has not yet been studied enough for distributed photovoltaic systems is the azimuth and tilt of rooftop photovoltaic panels, as previous studies of grid impacts and hosting capacity have tended to assume uniform and optimal roof facet conditions. In this study, rooftop facet orientation distributions are presented and analyzed for all single-family buildings in the Swedish city of Uppsala, based on LiDAR-based data that consist of every roof facet from the around 13,500 single-family buildings in the city. From these distributions, novel methods to proportionally include less suitable roofs for every penetration level are proposed using a simple method based on normal and uniform probability density functions, and are tested for both time-series and stochastic hosting capacity analysis. The results show that under the assumption that the best roof facets are utilized first, a uniform distribution for rooftop facet azimuth and a normal distribution for rooftop facet tilt with parameters that depend linearly on the penetration level were shown to be accurate. The hosting capacity simulations demonstrate how the proposed methods perform significantly better in estimating the photovoltaic hosting capacity than the more common simplified methods for both time-series and stochastic hosting capacity analysis. The proposed model could help distribution system operators as well as researchers in this area to model the rooftop facet orientation uncertainty better and improve the quality of aggregated photovoltaic generation models and hosting capacity analyses.

Simplified Method of Stability Analysis of Nonlinear Systems without Using of Lyapunov Concept

Simplified Method of Stability Analysis of Nonlinear Systems without Using of Lyapunov Concept

A simple, sensitive and label-free method for miRNA analysis in gastric cancer via catalytic hairpin assembly assisted programming of split-G-quadruplexes.

Accurate analysis of miRNA is valuable for the diagnosis of various diseases. Herein, a sensitive and accurate fluorescence method was developed for miRNA detection based on catalytic hairpin assembly (CHA) and split-G-quadruplex (split-G4) based signal reactions. The presence of target miRNA activated the CHA process through unfolding the H1 probe, which could continuously induce the proximity of split-G4. The formed intact G4 can be specifically recognized by the commercial fluorescent dye ThT (thioflavin T), allowing for the highly sensitive, label-free detection of miRNAs. By utilizing split-G4 to generate a signal, the method exhibited a low background signal and a high reliability. In addition, the method is demonstrated to be applied for clinical sample detection, implying its promising prospect for disease diagnosis.

Method Development and Validation of Gallic Acid in Liquid Dosage Form by Using RP-HPLC Method.

A simple, rapid, precise, sensitive, and reproducible reverse-phase high-performance liquid chromatography (RP-HPLC) method has been developed for the quantitative analysis of gallic acid in the pharmaceutical dosage form. Chromatographic separation of gallic acid was achieved on Waters Alliance-e 2695, by using Waters X-Terra RP-18 (150×4.6mm, 3.5μ) column and the mobile phase containing 0.1% formic acid and ACN in the ratio of 70:30% v/v. The flow rate was 1.0mL/min; detection was carried out by absorption at 275 nm using a photodiode array detector at ambient temperature. The number of theoretical plates and tailing factor for gallic acid was NLT 2000 and should not be more than 2 respectively. Percentage relative standard deviation of peak areas of all measurements is always less than 2.0. The proposed method was validated according to ICH guidelines. The method was found to be simple, economical, suitable, precise, accurate, and robust method for quantitative analysis of gallic acid.

Rapid microRNA detection method based on DNA strand displacement for ovarian cancer cells.

The current cancer detection methods are heavily dependent on the component analysis of corresponding cancer antigens. There is a lack of effective and simple clinical methods of ovarian cancer screening, which hinders the early identification for ovarian cancer and its treatment. To develop a simple and rapid method for quantitative analysis of ovarian cancer, we developed a DNA strand displacement-based method and finished the rapid detection of miR-21 in ovarian cancer cells within 5 min by a one-step isothermal reaction. The fluorescence intensity trajectory had a good linear relationship with miR-21 concentrations in the range of 100 fM-100 nM, with a lower limit of 6.05 pM. This detection method is simple, faster, and accurate. Besides, it can be applied to detect the miRNA biomarkers of other cancers by changing the preset sequences of toehold.

Development of a simple and reliable LC-MS/MS method to simultaneously detect walnut and almond as specified in food allergen labelling regulations in processed foods

We developed a simple and reliable analytical method using high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) to simultaneously detect walnut and almond as specified in regulations for food allergen labelling in processed foods. Five specific target peptides derived from walnut 2S albumin and 7S globulin and three target peptides from almond 11S globulin were selected by analysing several varieties of walnut and almond, eight kinds of other nuts, and ten kinds of major allergen ingredients or cereals. The limit of detection for the walnut 2S albumin peptide GEEMEEMVQSAR (m/z 698.3 [precursor] > 316.1 [product]) was 0.22 ± 0.02 μg/g, and that for almond 11S globulin peptide GNLDFVQPPR (m/z 571.8 [precursor] > 369.2 [product]) was 0.08 ± 0.02 μg/g when extracted walnut and almond protein were spiked into butter cookie chocolate ice cream. These peptides had good linearity (R2 > 0.999) for each calibration curve with a range of 0.1–50 μg/mL protein concentration in the sample solutions, and sufficient recovery rates (90.4–101.5%) from the spiked samples. The developed analytical approach is applicable to a wide variety of processed foods for food allergen labelling.

Simple multi-residue analysis of persistent organic pollutants and molecular tracers in atmospheric samples

We present a simple, selective and sensitive analytical method to quantitatively determine a wide range of halogenated persistent organic pollutants and molecular tracers in atmospheric samples. Identification and quantification was carried out by high-resolution gas chromatography, hyphenated with low-resolution mass spectrometry operating in electron impact (EI) and electron capture negative ionization (ECNI) mode. Optimization on a number of instrumental parameters was conducted to obtain ultra-trace detection limits, in the range of few fg/m3 for organohalogen compounds. Repeatability and reproducibility of the method was thoroughly evaluated. The analysis was validated with standard reference materials and successfully applied to actual atmospheric samples. The proposed multi-residue method provides a precise, affordable and practical procedure of sample analysis for environmental research laboratories with conventional instrumentation on a routine basis.•A simple combination of alumina, florisil and silica gel adsorbents was applied to sufficiently isolate polychlorinated biphenyls, organochlorine pesticides, polycyclic aromatic hydrocarbons, long chain n-alkanes, hopanes and steranes.•Full elution was achieved in two successive fractions, using small volumes of n-hexane and n-hexane/dichloromethane to recover all target substances.•To maximize analytical response, optimization was applied for three operating parameters in ECNI mode: i) ion source temperature; ii) emission current; and iii) electron energy.

To the Calculation of the Unsteady Temperature Field of a Cylindrical Body

Determining the temperature regime of cylindrical bodies in the initial period of time, i.e. at small values of the Fourier number, is a rather time-consuming task. In the calculation process, it is necessary to take into account a large number of members of the series to obtain the result of the required accuracy. In this case, it is required to calculate the eigenvalues of the characteristic equation for each term of this series. The article offers a fairly simple and effective analytical method for determining eigenvalues with high accuracy. The method is based on the use of a special function, the inverse of the relation of the Bessel functions of the first kind of zero and first order. In this case, the procedure for determining eigenvalues is reduced to a simple fast-converging iterative process. Using this procedure allows you to determine any eigenvalue of the characteristic equation with high accuracy required for engineering calculation. The application of this method in engineering practice significantly simplifies the process of determining the temperature regime of cylindrical bodies, and can also be extended to other tasks.

New Analytical Methods for the Determination of New Anti-Viral Drug Favipiravir: A Potential Therapeutic Drug Against Covid-19 Virus, in Bulk and Dosage Forms.

Simple, accurate and robust analytical methods have been developed and validated for the determination of favipiravir (FVPR) by RP-HPLC and UV spectroscopy techniques as per the ICH guidelines. In the RP-HPLC method for FVPR determination, the mobile phase was ammonium acetate buffer pH 6.5 in pump Aand methanol in pump B. The C18 (Sunfire) 5 μm, 4.6 × 250 mm column was used as a stationary phase, and the detection wavelength was at 323 nm. Under these conditions, FVPR was eluted as a sharp peak at 2.65 min and the overall time taken for each injection was 10 min. In case of the UV spectroscopy method, standard FVPR solutions were prepared with pure ethanol and scanned from 250 to 400 nm and a flourishing spectrum was obtained at 323 nm. Hence, the wavelength of 323 nm was fixed for the whole process of validation in both techniques. The limit of detection (LOD) and limit of quantification (LOQ) in the RP-HPLC method were 1.0 and 3.5 μg/mL, respectively, and the linearity was established in the 10 to 50 μg/mL range. In the UV spectroscopy method, the LOD and LOQ values were found to be 3.5 and 12 μg/mL, respectively, and the linearity was established within 20 to 60 μg/mL range. The regression coefficient was found to exceed 0.999 in both methods. The proposed RP-HPLC and UV spectroscopy techniques are simple, accurate, rugged and robust.

Analytical Method Development and Validation of Some Biosimilar Drugs by High Performance Thin Layer Chromatography

A simple and rapid HPTLC analytical method has been developed and validated for the determination of Etanercept and Filgrastim in pure form and in marketed formulation. Both the drugs were chromatographed on silica gel 60 F254s HPTLC plates, as stationary phase. The mobile phase optimized for Filgrastim and Etanercept was Water: n-butanol (7.5:2.5 v/v) and Isopropyl alcohol: water (6.5:4.5 v/v), respectively. The chromatogram obtained was scanned at 225 nm and 222 nm for filgrastim and etanercept which resulted in a retention factor of 0.45 ± 0.07 and 0.32 ± 0.03, respectively. The method was validated for parameters like linearity, accuracy, precision, specificity and robustness. Recovery studies were performed at three concentration levels, to demonstrate suitability, accuracy and precision of proposed method. Statistical analysis proved that the proposed method is accurate and reproducible with linearity in the range of 500 to 3000 ng/band for filgrastim and 200 to 1200 ng/band for etanercept. The limit of detection and limit of quantification for filgrastim was found to be 63.418 ng/band and 192.177 ng/band. For etanercept, LOD and LOQ were found to be 33.381 ng/band and 101.153 ng/band, respectively. The proposed method can be employed for the routine analysis of selected biosimilars.

Simplified structural analysis method for traditional timber buildings with cross frame

Simplified structural analysis method for traditional timber buildings with cross frame

A New HPLC Method for Argatroban Intermediate and its Related Substance

A simple and specific quantitative analysis method has been developed and validated for the determination of Argatroban Intermediate and its related substance. This method uses reversed-phase high performance liquid chromatography (RP-HPLC) to analyze the Argatroban Intermediate and its six related substance. Chromatographic conditions for RP-HPLC with UV detector were as follows: column, Agela Venusil MP, 250mm×4.6mm, 5μm; column temperature, 45°C; mobile phase, a 65: 35 (v/v) mixture of ammonium acetate buffer: methanol; flow rate, 1.0 mL/min. The detection wavelength was UV 272 nm. Under these conditions, excellent linearity was obtained (r2>0.9995) in the concentration range of 0.47~4.71μg/ml for Argatroban Intermediate, 0.30~5.04μg/ ml for impurity A, 0.12~4.93μg/ml for impurity B, 0.29~4.81μg/ ml for impurity C, 0.30~4.96μg/ml for impurity D,0.12~4.77μg/ ml for impurity E and 0.12~4.86μg/ml for impurity F, respectively. The LOQ was 0.5μg/ml for Argatroban Intermediate, 0.3μg/ml for impurity A, 0.125μg/ml for impurity B, 0.3μg/ml for impurity C,0.3μg/ml for impurity D, 0.125μg/ml for impurity E and 0.125μg/ ml for impurity F. The maximum R.S.D.(%) of the content of Argatroban Intermediate and its each impurity was 5.3% under the deliberate variations in method parameters.

Evaluation of a simple activity measurement method in rats.

[Purpose] Behavioral analysis is widely used in animal research. However, such analysis requires specialized equipment and can be difficult to perform. Therefore, this study aimed to explore and validate a simple behavioral analysis method. [Participants and Methods] For behavioral assessments, Wistar rats were placed in a rearing cage and videotaped from two directions: overhead and side view. The filmed videos were analyzed using ImageJ software to calculate the distance traveled and activity and inactivity times of the rats. Intraclass correlation coefficients 1 and 2 were calculated to examine the reliability of the behavioral analysis method. [Results] Intraclass correlation coefficients 1 and 2 for distance traveled and activity and inactivity times determined using the behavioral analysis method showed high reliability. [Conclusion] The behavioral analysis method validated in this study used inexpensive and easily accessible equipment and devices. The results show high correlation coefficients for the measurement of distance traveled and activity time performed by experimental animals, demonstrating the reliability of this simple method.

PENGARUH KUALITAS PELAYANAN TERHADAP PENCAPAIAN TARGET PAJAK BUMI DAN BANGUNAN PADA BADAN PENDAPATAN DAERAH UPT TENGAH KOTA BANDUNG

Land and building taxes have an important role and great benefits for people's lives. Land tax is the imposition of taxes on the surface of the earth (land) based on Law number 12 of 1985. While the building tax is the imposition of taxes on technical constructions that are permanently planted or placed on construction land, the technique can be used as a residence, or a place of business, or workable place.
 This study aims to determine the effect of service quality on the achievement of land and building tax targets. The sampling technique used is simple random sampling with 40 taxpayer respondents of Central UPT Bandung City. This research data uses primary data directly through questionnaires and analyzed using Statistical Product Service Solution. The data analysis method used in this research is to use a simple linear regression analysis method. In obtaining the necessary data, the preparation of this final project uses a research technique developed into closed questions with a Likert scale.
 The results of this study indicate that the effect of service quality (X1) has a positive and significant effect on the achievement of the land and building tax target (Y).

Label-free microfluidic device reveals single cell phagocytic activity and screens plant medicine rapidly.

Phagocytic activity is an extremely important indicator that evaluates medicinal effects related to the immune system and functions to investigate the mechanism of how a drug works under conditions such as immunological regulation, immune tolerance, inflammation, cancer, etc. Current techniques based on flow cytometry, fluorescence imaging or numbering CFUs after cell lysis for detecting phagocytosis suffer from long terms of bacteria culturing and complex preparation steps for fluorescent labeling or require a large amount of cell samples to be tested. This study aims at developing a simple and fast method for testing the phagocytic activity of unlabeled and native cells, taking advantage of very high-resolution direct current insulator-based dielectrophoresis (DC-iDEP). The properties of cells are characterized by native whole cell biophysical properties. This strategy not only eliminates the time-consuming bacterial culture work after cell lysis, but also lowers the expenses of bacteria labeling. The introduction of microfluidics reduces the sample volume or reagent needed. The analysis of the biophysical property distributions of native cells and medicine treated cells may lead to a less expensive and rapid tool for evaluating medicinal effects. Furthermore, berberine was investigated for decreasing the phagocytic activity of macrophages and used for comparison of activities. This study works on establishing a label-free, unbiased, and non-destructive method to determine cell phagocytic activity and investigate its use in evaluating medicinal effects on phagocytosis in a single step within a short time.

Simple analytical method for total biogenic amines content determination in wine using a smartphone.

A simple, fast, and green smartphone-based procedure for total biogenic amines content determination in wine was developed and validated. Sample preparation and analysis were simplified to make the method suitable for routine analyses even in resource-scarce settings. The commercially available S0378 dye and smartphone-based detection were used for this purpose. The developed method has satisfactory figures of merit for putrescine equivalent determination with R2 of 0.9981. The method's greenness was also assessed using the Analytical Greenness Calculator. Samples of Polish wine were analysed to demonstrate the applicability of the developed method. Finally, results obtained with the developed procedure were compared with those previously obtained with GC-MS in order to evaluate the equivalence of the methods.

Human Schwann Cells in vitro III. Analytical Methods and a Practical Approach for Quality Control.

This paper introduces simple analytical methods and bioassays to promptly assess the identity and function of in vitro cultured human Schwann cells (hSCs). A systematic approach is proposed to unequivocally discriminate hSCs from other glial cells, non-glial cells, and non-human SCs (authentication), identify hSCs at different stages of differentiation, and determine whether individual hSCs are proliferative or senescent. Examples of how to use distinct cell-based approaches for quality control and routine troubleshooting are provided to confirm the constitution (identity, purity, and heterogeneity) and potency (bioactivity) of hSC cultures from multiple sources. The bioassays are valuable for rapidly gauging the responses of hSCs to mitogenic and differentiating factors and ascertaining the cells' basic properties before performing co-culture or cell grafting studies. The assays are image based and use adherent hSCs established in monoculture to simplify the experimental setup and interpretation of results. Finally, all sections contain thorough background information, notes, and references to facilitate decision making, data interpretation, and ad hoc method development for diverse applications.

Thin Layer Chromatographic Method for Detection of Conventional Drug Adulterants in Herbal Products

Commercially available conventional drugs have been used to adulterate herbal products. Considering the rapid growth of herbal products’ market, it is essential to screen herbal products for the presence of conventional drugs. Simple analytical methods are needed for the rapid screening of conventional drugs that are likely to be adulterated in herbal products. Thin layer chromatography (TLC) methods for screening twelve conventional drugs in herbal products have been developed and applied. The analytes were extracted from herbal products using acetonitrile:methanol:acetic acid:water (4:4:1:1, v/v). Solvent mixture of dichloromethane:ethyl acetate:methanol (75:15:10, v/v) separated well trimethoprim, sildenafil, paracetamol, and sulfamethoxazole while pyrimethamine, metronidazole, and sulfadoxine were well separated by dichloromethane:ethyl acetate:methanol (77.5:12.5:10, v/v). In addition, acetyl salicylic acid, ibuprofen, diclofenac, quinine, and lumefantrine were well separated by ethyl acetate:methanol:30% ammonia (75:22.5:2.5, v/v). Chromatographic separations were found to be highly reproducible, and more than 10 samples can be analysed in one run. The method was applied in the screening of 229 herbal products. Consequently, 24.0% of the samples contained one adulterant, while 21.4% contained at least two adulterants. All conventional drugs detected in herbal products were not mentioned on the labels and therefore the consumers are kept unaware of their side effects and health problems. Further studies for confirming and quantitatively determining the adulterants in a wide range of products as well as a systematic toxicological analysis of the adulterants in herbal products are recommended.

The concept Muslim: discourses in Bosnian, Croatian, German and Serbian webcorpora

The aim of this contribution is to examine the meaning of the word musliman or German Muslim and to answer the question whether the meaning of this word in a dictionary can be mapped by means of classical distributional analysis, and whether further meanings can be captured by this method. In addition, a simple method for a distributional semantic analysis is presented. The basis of the investigation is the assumption common in corpus–based semantics and lexicography that the meaning of words can be interpreted from the context and thus polysemy and synonymy can be recognized. The article examines four web corpora for Bosnian, Croatian, Serbian and German. First, the context is analysed, assuming that the syntactic structures in the context are themselves inherently meaningful. Specifically, adjective attributes are used to analyse properties of the keyword, coordination partners as indicators for relevant categories, verbs with the keyword as subject and accusative object as indicators for typical actions the keyword performs or is target of. In a second step, the lexemes that occur in these four contexts are clustered and the semantic dimensions of the keyword are determined. The results suggest that the distributional method can in principle map dictionary definitions well. However, this is mainly true for contexts which involve attributes and coordination but not for action–related syntactic configurations. Overall, the most salient semantic dimensions of the lexeme are those pertaining to members of a religious community, members of a regional ethnic group, and experienced or induced aggression. Here, the four corpora differ considerably: while German usage almost exclusively focuses on religion–related aspects, the other corpora also contain ethnic/regional components, as well as the discourse of aggression. This aggression is mainly verbal in German, but physical in the other corpora. Neutral meaning components for the word musliman are salient only in the Bosnian corpus.