Coefficient Of Variation Values Research Articles

Alcohol concentrations for determining soil particle density using the volumetric glassware method

The objective of this study was to evaluate the efficiency of alcohol in concentrations of 0.0, 47.6, 70 and 99 °GL, to determine the soil particle density (rp) with the Volumetric Glassware Method (VG), verifying the best time of analysis and the possibility of alternatives to 99 °GL alcohol concentration. The soil samples were collected in five experimental areas of the Fundação ABC (Arapoti, Castro, Itaberá, Ponta Grossa and Tibagi), at 0.0-0.20 m depth, stored in a plastic bag and forwarded to the Soil Physics laboratory of the Federal University of Paraná. Analyzes with alcohol concentrations were performed with five repetitions, for each location, totaling 100 samples. The comparison of the “rp obtained with VG and 99 °GL alcohol” (rpVG.99) vs “rp with alternative methods” (water: rpVG.w; 47.6 °GL alcohol: rpVG.47.6; and 70 °GL alcohol: rpVG.70) values were performed considering linear regression analysis, Box Plot diagram, coefficient of variation (CV) and determination (R2), index of agreement (d) and mean absolute error (MAE). The 70 °GL concentration obtained good associations with the 99 °GL concentration (R2 0.82), as well as low values of CV and MAE. The other concentrations analyzed had promising results. For the soils analyzed, the 70 °GL alcohol concentration can replace 99 °GL to obtain rp values with the Volumetric Glassware Modified Method, requiring data readings after 48 h.

SISTEM PRODUKSI PADI ORGANIK DI KABUPATEN LAMPUNG TENGAH: ANALISIS USAHATANI DAN PASCAPANEN

This research aims to know the farming income of organic rice; production risk and price risk faced by the organic rice farmers. This research was conducted in North Lampung Regency in March-April 2019. This sample of this research consists of 31 organic rice farmers which are taken by using census method. Thedata analysis method are farming income analysis and risk analysis which uses statistics method by counting variance, standard deviation, and coefficient of variation (CV). The results showed that the average of farming income that was achieved by organic rice farmers amounted to IDR 60,525,621.96. The production and price risk are classified into the low category because the value of CV of production risk is 0.13 and CV of price risk is 0.10.Key words: income, organic rice, risk.

A 3-min All-out Upper-body Ergometer Test For Competitive Swimmers.

We examined the application of a land-based swimming ergometer 3-min all-out test to determine physiological predictors of swimming performance. Fourteen young elite swimmers participated (males: n=6; females: n=8). The swimmers completed two 3-min upper-body all-out tests on a swimming ergometer. Additionally, the swimmers completed freestyle swim races ranging from 50 m to 1500 m. High test-retest reproducibility (r=0.98 and coefficient of variation values <7.5%) was evident for ergometer derived peak, mean and critical power. Very strong correlations (r>0.87, p<0.001) were obtained between the 200-, 400-, 800- and 1500-m swimming performances and derived critical speed. Moreover, correlations were found between peak force and peak power and 50-m performance, in addition to critical power and performance for all distances. The critical speed was the dominant predictor of 200- to 1500-m performances (r=0.84-0.99). In conclusion, the land-based 3-min all-out swimming ergometer test is reliable and valid in predicting swimming performance in competitive swimmers and evaluates important physiological components in swimmers independent of technical abilities.

Genetic Variability, Heritability, and Clustering Pattern Exploration of Bambara Groundnut (Vigna subterranea L. Verdc) Accessions for the Perfection of Yield and Yield-Related Traits.

Bambara groundnut (Vigna subterranea L. Verdc.) is considered an emerging crop for the future and known as a crop for the new millennium. The core intention of this research work was to estimate the variation of landraces of Bambara groundnut considering their 14 qualitative and 27 numerical traits, to discover the best genotype fitted in Malaysia. The findings of the ANOVA observed a highly significant variation (p ≤ 0.01) for all the traits evaluated. There was a substantial variation (7.27 to 41.21%) coefficient value, and 14 out of the 27 numerical traits noted coefficient of variation (CV) ≥ 20%. Yield (kg/ha) disclosed positively strong to perfect high significant correlation (r = 0.75 to 1.00; p ≤ 0.001) with traits like fresh pod weight, dry pod weight, and dry seed weight. The topmost PCV and GCV values were estimated for biomass dry (41.09%) and fresh (40.53%) weight with high heritability (Hb) and genetic advance (GA) Hb = 95.19%, GA = 80.57% and Hb = 98.52%, GA = 82.86%, respectively. The topmost heritability was recorded for fresh pod weight (99.89%) followed by yield (99.75%) with genetic advance 67.95% and 62.03%, respectively. The traits with Hb ≥ 60% and GA ≥ 20% suggested the least influenced by the environment as well as governed by the additive genes and direct selection for improvement of such traits can be beneficial. To estimate the genetic variability among accessions, the valuation of variance components, coefficients of variation, heritability, and genetic advance were calculated. To authenticate the genetic inequality, an unweighted pair group produced with arithmetic mean (UPGMA) and principal component analysis was executed based on their measurable traits that could be a steadfast method for judging the degree of diversity. Based on the UPGMA cluster analysis, constructed five distinct clusters and 44 accessions from clusters II and IV consider an elite type of genotypes that produce more than one ton yield per hectare land with desirable traits. This study exposed an extensive disparity among the landraces and the evidence on genetic relatives will be imperative in using the existing germplasm for Bambara groundnut varietal improvement. Moreover, this finding will be beneficial for breeders to choose the desirable numerical traits of V. subterranea in their future breeding program.

Natural variation of the cardiac transcriptome in humans

ABSTRACT We investigated the gene-expression variation among humans by analysing previously published mRNA-seq and ribosome footprint profiling of heart left-ventricles from healthy donors. We ranked the genes according to their coefficient of variation values and found that the top 5% most variable genes had special features compared to the rest of the genome, such as lower mRNA levels and shorter half-lives coupled to increased translation efficiency. We observed that these genes are mostly involved with immune response and have a pleiotropic effect on disease phenotypes, indicating that asymptomatic conditions contribute to the gene expression diversity of healthy individuals.

Model for Evaluating the Effectiveness of the Cloud Center with a High Degree of Virtualization in Terms of Group Requests

The current state of information technology is to develop and implement new approaches to the computational process. Evaluating the effectiveness of cloud centers is an important challenge for research, but it is complicated by the dynamic of cloud environments and a variety of user requests. This evaluation is vital in cases where virtualization is used to provide well-defined computing resources for users. The proposed model for evaluating the effectiveness of cloud centers in a high degree of virtualization to solve this problem has been proposed. Compared to existing, it considers the ability to service requests for group requests and the distributed time of service requests. The model is based on a two-stage approximation technique. The main non-Markov process is first modeled as an embedded semi-Markov process, then modeled as an approximated Markov process but only when receiving group request flows. The technique of constructing Markov links to build the model has been used. This model provides a full probability distribution of request waiting time, response time to execute requests, and the number of requests in the system. The results show that the performance of cloud centers is highly dependent on the coefficient of variation (CoV), request service time, and the size of the group flow (i.e., the number of requests in the group flow of requests). The larger the flow rate and/or the value of the coefficient of variation of the service time of requests, the longer the response time. But this helps reduce the use of resources by cloud providers. As a result, the work shows that in the conditions of large group flow of requests and/or large value of CoV, it is possible to increase the efficiency of cloud centers by grouping requests using the criterion of homogeneity.

A test-retest reliability study of assessing small cutaneous fibers by measuring current perception threshold with pin electrodes.

BackgroundThe quantitative measurement of current perception threshold (CPT) has been used as a method to assess the function of nerve fibers in neuropathy diseases. The aim of this study was to assess the test-retest reliability measuring CPT using the circular pin electrodes for assessing the function of cutaneous thin nerve fibers.MethodsCPT measurement was repeated on two separate days with at least one-week interval in 55 volunteers. Superficial blood flow (SBF) and skin temperature (ST) were measured on the skin in an around area concentric to the circular pin electrodes after the process of finding CPTs. The coefficient of variation (CV) and intra-class correlation coefficient (ICC) were calculated. The correlation between each two of CPT, SBF increment and ST increment was analyzed.ResultsNo significant differences were found for CPT, SBF and ST between two sessions. SBF was found to be significantly increased after the process of finding CPT. CPT values of males were found to be higher than females. SBF increment was found to be positively correlated with ST increment. The ICC values for CPT, SBF and ST were 0.595, 0.852 and 0.728, respectively. The CV values for CPT, SBF and ST were 25.53%, 12.59% and 1.94%, respectively.ConclusionsThe reliability of CPT measurement using circular pin electrodes is fair, and need consistence of measurements in longitudinal studies.

Polydopamine-gold composite-based electrochemical biosensor using dual-amplification strategy for detecting pancreatic cancer-associated microRNA

Herein, we developed a dual-amplification-boosted, translational electrochemical biosensor for the detection of pancreatic cancer-associated microRNA, miR-196b. A biosensing event occurred when a hairpin target probe recognized miR-196b as a result of the opening of an electrode hairpin probe on a polydopmine-gold (PDA-Au) composite-modified screen-printed carbon electrode. The PDA-Au composite was synthesized in a alkaline condition where dopamine polymerized into polydopamine while gold(III) ion was in-situ reduced to gold nanoparticle, characterized by FT-IR, SEM, cyclic voltammetry and gel electrophoresis. The electrode modifier, PDA-Au, provided a functionalizable interface for the sensitization of electrode probes; besides, a suitable hydrophilic interface for an aqueous biosensing reaction, confirmed by water contact angle measurement and cyclic voltammetry. Validated by UV-VIS analysis and gel electrophoresis, the single polymerase created a dual amplification by target-recycling and generation of an catalytic DNAzyme product on the electrode probe-functionalized PDA-Au@SPCE. The isothermal, dual amplification was thereby translated into a TMB/H2O2-resulted electrochemical signal, acquired by scan wave voltammetry for quantifying target miR-196b. The novel electrochemical biosensor offered a detection limit of 0.26 pM, with a nice analytical reproducibility by CV (coefficient of variance) value of 8.5 ± 3.1%, and a recovery rate of 105 ± 4.1% obtained from a spiked, real human serum sample. The proposed biosensor showed great promise as a complementary tool for real sample detection in the clinic.

Using multiple objective calibrations to explore uncertainty in extreme event modeling

Deterministic watershed models are often used to estimate the probable maximum flood (PMF). An approach for investigating the uncertainty in extreme flood modeling is proposed. Using different calibration objectives, several automatic calibrations of the University of British Columbia watershed model (UBCWM) are conducted and the resulting collection of optimal combinations of parameter values are used to simulate the extreme event. An application to the Coquitlam River Watershed above Coquitlam Dam in southwestern British Columbia shows that the variability among the PMF estimates is relatively small in comparison with the potential uncertainties in estimating extreme events, with coefficient of variation values for peak flow, event volume, and time to peak of 4%, 1%, and 1%, respectively. The PMF-based simulations are relatively insensitive to the different measures of calibration performances.

Small, But Significant Declines In Crop Productivity On Low Fertility Soils

Agricultural yields are susceptible to losses during extreme weather events related to climate change, jeopardizing food security. Yield losses may be mediated by underlying quality or variation of agricultural land in soil fertility, topography, drainage, and growing degree days. For instance, crops grown on poor quality land may be more susceptible to the negative consequences of climate variation as compared to crops grown on high quality land. This study investigated yield response for corn, soybeans, and pasture to different land qualities across Ontario from 2011 to 2017. Yield is approximated using the Normalized Difference Vegetation Index (NDVI), which is a satellite-derived measure of biomass production. For three focal crops (soybean, corn, and pasture), the average maximum NDVI and the coefficient of variance (CV) of maximum NDVI were aggregated at a provincial and county scale for each land quality classification. Relatively stable CV values were evident across all land qualities, yet certain counties showed greater variation in productivity on poor quality land suggesting greater susceptibility to extreme weather. Over 7 years, there were small but significant declines in NDVI in response to poor quality land for all three crop types. This suggests that agricultural producers cannot overcome the biophysical limitations of poor quality land on crop yield. Understanding differential crop productivity responses to land quality can help producers mitigate crop losses to climatic variation, thus equally stabilizing food availability.

Piston motion control for a dual free piston linear generator: predictive-fuzzy logic control approach

The free-piston engine has a lot of potential to alter the conventional combustion engine due to mechanical structural simplicity, high engine efficiency, reducing hazardous gas emission and fuel flexible combustion. However, accuracy of piston motion control is a major challenge in all types of free-piston engine as well a dual free piston engine generator (DFPG) because of not having a crankshaft mechanism. This article describes a simulation investigation of a predictive-fuzzy logic control method conducted on the DFPG prototype in University of Ulsan. First, the simulation model of the DFPG consisted of a free-piston engine and a linear alternator is established and running in Matlab/Simulink environment. Then simulation result is validated against experimental data to prove validity of the simulation model. Second, a predictive-fuzzy logic (PFL) control method is proposed to apply to the DFPG and its performance is carried out using the full-cycle simulation model. The PFL strategy is demonstrated to improve the DFPG performance and more effective than the PID one in terms of settling time, TDC error, and cycle-to-cycle variation. According to results, the PFL controller reduces settling time 30 % in comparison to PID controller. The PFL controller has also 0.52 mm better TDC position error than the PID controller is 0.76 mm. Coefficient of variation values is found to be 1.0 %, and 1.9 % for the PFL controller and PID controller, respectively. This means that the PFL controller is a powerful method to dampen cycle to cycle variations in the DFPG.

Reliability and Validity of Abdominal Skeletal Muscle Area Measurement Using Magnetic Resonance Imaging

Skeletal muscle mass measurement is the most important element for diagnosing sarcopenia. MRI has an excellent soft-tissue contrast, which can non-invasively assess abdominal skeletal muscle area (SMA) as well as CT. This study aimed to assess the validity and reliability of abdominal SMA measurement by comparing CT and MRI based on the fat image of IDEAL-IQ sequence at the lumbar level mid-L3. CT and MRI images of 32 patients diagnosed with various kidney diseases were used to analyze intra-observer variability among abdominal SMA measurements. This was done to evaluate the correlation of SMA between CT and fat images of MRI. SMA images were segmented using Materialise Mimics software before quantification. Interobserver reliability and validation of measurements was evaluated by two independent investigators. Abdominal SMA reproducibility and correlation between CT and MRI were then assessed using the intraclass correlation coefficient (ICC), coefficient of variation (CV), Bland-Altman plot, and Pearson's correlation coefficient respectively. The interobserver reliability of MRI was excellent. The CV value was 2.82% while the ICC values ranged between 0.996 and 0.999. Validity was high (CV was 1.7% and ICC ranged between 0.986 and 0.996) for measurements by MRI and CT. Bland Altman analysis revealed an average difference of 2.2% between MRI and CT. The Pearson's correlation coefficient was 0.995 (p < 0.0001). This result revealed that there was a strong correlation between the two technologies. MRI exhibited good interobserver reliability and excellent agreement with CT for quantification of abdominal SMA.

The missing parameter in renewable energy power quality analysis, i.e., the coefficient of variation: Case study of a 3-MW on-site wind turbine project in Ireland

Businesses are employing distributed generation techniques, such as wind turbines, to decarbonise their electrical energy supply by reducing their dependence on fossil-fuel-generated energy. This study investigates the effectiveness of a company making a €3,500,000 investment in a 3-MW on-site wind turbine to supply some or all of their factory electrical loads. The results should benefit the investing company and other potential investors by evaluating the economic, environmental, and social outcomes of the investment. A case study methodology was used. The study found that the payback period was six and a half years, and the turbine installation benefited the environment by offsetting 3,195 tonnes of CO2 per annum. As part of the power-quality analysis of the wind-turbine output, the short-term variability of the power output signal was calculated as the coefficient of variation values. The study found that the most stable power output is achieved when the turbine is generating at full output power (i.e., 3-MW). In addition to the existing range of traditional power quality parameters, the coefficient of variation parameter was found to be an essential aspect of electrical power quality and should be included in future practice.

Two-Year Reproducibility of Axial Length Measurements after Combined Phacovitrectomy for Epiretinal Membrane, and Refractive Outcomes.

Purpose: To determine the long-term reproducibility of axial length measurements and mean postoperative prediction errors after combined phacovitrectomy in patients with idiopathic epiretinal membranes. Design: Retrospective cohort study. Methods: The study included 43 patients who underwent combined phacovitrectomy and 30 patients who underwent only phacoemulsification. To determine the effect of vitrectomy, we compared patients treated with phacoemulsification only versus those treated with combined phacovitrectomy. Axial lengths were measured three times with a one-year interval, and the intraclass correlation coefficient (ICC), coefficient of variation (CV), and test–retest standard deviation (TRTSD) were assessed. Results: There was no significant change in axial length, and axial length measurements showed high reproducibility in all groups. ICC, CV, and TRTSD values were 0.997, 0.24%, and 0.056, respectively, for the vitrectomized eyes. The mean postoperative prediction error was −0.37 diopters(D) in vitrectomized eyes (p < 0.001), while it was +0.11 D in patients with phacoemulsification (p = 0.531). The myopic shift was more obvious in eyes with a shallower anterior chamber (p = 0.008) and a thicker lens (p = 0.025). Conclusions: Axial length measurements showed excellent long-term reproducibility at 2 years after combined phacovitrectomy. Myopic shifts were observed after combined phacovitrectomy, which was probably due to changes in the effective lens position after combined phacovitrectomy, rather than to changes in the axial length.

On the optimization of bone SPECT/CT in terms of image quality and radiation dose.

IntroductionThe purpose of this study was to present the optimization process of CT parameters to reduce patient exposure during bone SPECT/CT without affecting the quality of SPECT images with attenuation correction (AC).Material and methodsA fillable phantom reflecting realistic bone scintigraphy conditions was developed and acquired on an AnyScan SC. SPECT/CT scans were carried out with different x‐ray tube current values (10, 20, 30, 40, 50, 60, 70, 90, 110, 130, 150, and 200 mA) at three different high‐voltage values (80, 100, and 120 kV). The contrast (C) and coefficients of variation (CV) in the SPECT images as well as the signal‐to‐noise ratio (SNR) and noise (SDCT) in the CT images with CTDIvol were measured. An optimal acquisition protocol that obtained SPECT/CT images with no artifacts on both CT and SPECT images, acceptable C, SNR, CV, and SDCT values, and the largest reduction in patient exposure compared to the reference acquisition procedure was sought.ResultsThe optimal set of parameters for bone SPECT/CT was determined based on a phantom study. It has been implemented in clinical practice. Two groups of patients were examined according to the baseline and optimized protocols, respectively. The new SPECT/CT protocol substantially reduced patients’ radiation exposure compared to the old protocol while maintaining the required diagnostic quality of SPECT and CT images.ConclusionsIn the study, we present a methodology that finds a compromise between diagnostic information and patient exposure during bone SPECT/CT procedures.

Does the Organ-Based N Dilution Curve Improve the Predictions of N Status in Winter Wheat?

Accurately summarizing Nitrogen (N) content as a prelude to optimal N fertilizer application is complicated during the vegetative growth period of all the crop species studied. The critical nitrogen (N) concentration (Nc) dilution curve is a stable diagnostic indicator, which performs plant critical N concentration trends as crop grows. This study developed efficient technologies for different organ-based (plant dry matters (PDM), leaf DM (LDM), stem DM (SDM), and leaf area index (LAI)) estimation of Nc curves to enrich the practical applications of precision N management strategies. Four winter wheat cultivars were planted with 10 different N treatments in Jiangsu province of eastern China. Results showed the SDM-based curve had a better performance than the PDM-based curve in N nutrition index (NNI) estimation, accumulated N deficit (AND) calculation, and N requirement (NR) determination. The regression coefficients ‘a’ and ‘b’ varied among the four critical N dilution models: Nc = 3.61 × LDM–0.19, R2 = 0.77; Nc = 2.50 × SDM–0.44, R2 = 0.89; Nc = 4.16 × PDM–0.41, R2 = 0.87; and Nc = 3.82 × LAI–0.36, R2 = 0.81. In later growth periods, the SDM-based curve was found to be a feasible indicator for calculating NNI, AND, and NR, relative to curves based on the other indicators. Meanwhile, the lower LAI-based curve coefficient variation values stated that leaf-related indicators were also a good choice for developing the N curve with high efficiency as compared to other biomass-based approaches. The SDM-based curve was the more reliable predictor of relative yield because of its low relative root mean square error in most of the growth stages. The curves developed in this study will provide diverse choices of indicators for establishing an integrated procedure of diagnosing wheat N status, and improving the accuracy and efficiency of wheat N fertilizer management.

Between-day reliability of IMU-derived spine control metrics in patients with low back pain

Inertial measurement units (IMUs) are a potentially useful tool for clinicians and researchers in assessing spine movement biomechanics and neuromuscular control patterns. This study assessed the between-day reliability of the HIKOB FOX IMU in measuring local dynamic stability (LDS) and variability of trunk movements in patients with chronic low back pain (LBP). The local divergence exponent (λmax) was used to quantify LDS and the mean standard deviation (MeanSD) between cycles was used to quantify variability during 30 repetitive cycles of flexion/extension, rotation, and complex movement tasks. For λmax the average coefficient of variation (CV) was ~10% in the flexion/extension and rotation tasks, and all CV values were <20% when also including the complex task. ICC values for λmax ranged from 0.28 to 0.81. Reliability of λmax was similar between the pelvis and thorax segments (CV: ~10%, ICC: 0.48–0.78) and worse for the lumbar spine (CV: ~15%, ICC: 0.28–0.59). The CV for MeanSD was typically in the range of 20–30%, with even greater CV in the non-primary axes during each task (30–52%). Similarly, ICC values were lowest about the anterior-posterior axis in the flexion/extension task (ICC: 0.15–0.29) and largest about the longitudinal axis in the rotation task (ICC: 0.76–0.88). The moderate between-day reliability of λmax in the sagittal and transverse planes offers improvement over manual and subjective tests with poor reliability that are currently used in clinics. The minimal detectable differences presented give a threshold for change in research and rehabilitation in patients with LBP.

A NEW CLASSIFICATION PROPOSAL OF COEFFICIENTS OF VARIATION FOR MORPHO-AGRONOMIC TRAITS IN SNAP BEANS

The aim of this study was to present a classification proposal for coefficients of variation (CV) of morpho-agronomic traits in snap bean. The CV values were obtained from 53 studies related with snap beans published between 1987 and 2018, yielding a total of 372 data. The following traits were assessed: commercial pod yield, total pods yield, pod length, pod diameter, mean pod weight, number of pods per plant, number of seeds per pod and fiber pod content. Since verified the normal distribution of data, the CV were classified by values of mean (m) and standard deviation (sd) as: low [≤ (m – 1sd)]; medium [(m – 1sd) (m + 2sd)]. The results indicated that the pod diameter, pod length, mean pod weight and number of seeds per pods are variables weakly influenced by the environment. In contrast, the other traits related had the highest range of CV. The classification proposed in the present study provides a useful tool for researchers interested in estimating the accuracy of their experiments.

Impact of new Rexod® injection form on blood microcirculation in rat skin

Background. Free radical oxidation underlies many morbid processes in various organs and tissues, including skin. A major antioxidant preventing the free radical impact is superoxide dismutase (SOD). A particularly valued SOD-containing agent is recombinant human SOD, Rexod, possessing a wide spectrum of medical applications in form of lyophilisate. Marketing of a new Rexod® injection preparation in form of solution requires research into its properties, including the impact on blood microcirculation in skin, especially with the lack of relevant clinical trials.Objectives. Evaluation of anticipated positive effects of the new injection form of Rexod® on blood microcirculation in rat skin.Мethods. The new Rexod® preparation impact on blood microcirculation in skin was studied with laser Doppler fl uometry by recording the following non-oscillatory parameters of the basal blood fl ow: microcirculation (MC), mean squared deviation (MSD) and coeffi cient of variation (CV). Blood fl ow fl uctuations were measured in a wavelet analysis at different frequency bands: 0.0095–0.02, 0.02–0.046, 0.07–0.15, 0.15–0.4 and 0.8–0.16 Hz corresponding to endothelial (Ae), neurogenic (An), myogenic (Am), respiratory (Ar) and pulse (Ap) rhythm amplitudes, respectively.Results. The new Rexod® injection preparation at a dose of 8000 U/kg after 15 min of intraperitoneal administration in rats caused a statistically signifi cant (p &lt; 0.05) increase in the blood fl ow fl uctuation amplitudes Ae (43.1%), An (43.4%), Am (60.8%), Ar (58.3%) and Ap (32.0%) compared to the control group. Because the Ae fl uctuations coincide with nitric oxide (NO) emission episodes, such a growth indicates an elevated NO excretion by endothelial cells leading to endothelium-dependent vasodilation. The observed changes in blood microcirculation in skin are also associated with higher integral values of the basal blood fl ow, MC (33.4% increase), MSD (14.0%) and CV (27.6%), although only MC and CV values were statistically signifi cant (p &lt; 0.05). The results obtained suggest that the new injection form of Rexod® stimulates endothelial NO excretion, exerts adrenergic relaxation in smooth muscle cells of arteriolae and arteriovenular anastomoses, reduces precapillary sphincter and arteriolar contractility through Ca2+-dependent muscle relaxation, affects respiratory modulation of the venular blood microcirculatory compartment and vegetative cardiac support, intensifi es arterial blood fl ow by increasing the cardiac output.Conclusion. Application of the new Rexod® injection form improves blood microdynamics in rat skin via stimulating endothelium-dependent and independent vasodilatation and endothelial metabolism, decelerating adrenergic vasomotor activity and peripheral microvascular resistance. These processes in coupling improve blood fl ow to nutritive microvascular bed and normalise venular outfl ow. Our results provide further insights into pharmacodynamics of recombinant human SOD (Rexod).

Hydrophilic interaction liquid chromatography coupled to quadrupole time-of-flight mass spectrometry as a potential combination for the determination of sulfonamide residues in complex infant formula matrices

An accurate, sensitive and selective analytical method is proposed for sulfonamide residues analysis in infant formulas based on hydrophilic interaction liquid chromatography (HILIC) and quadrupole time-of-flight mass spectrometry in full scan mode. The sample preparation approach involves low-temperature lipid precipitation followed by dispersive solid-phase extraction with PSA and C18 sorbents, which was successfully optimized using Plackett-Burman design. In order to achieve high analytical sensitivity, the influence of HILIC conditions on sulfonamide ionization was investigated, such as the mobile phase composition, buffer concentration, and sample diluent for injection. The method performance characteristics, including linearity (range 5–120 µg kg–1), reliable limits of quantification (between 5 and 20 µg kg–1), recovery (72.9–109.2%) and precision (coefficient of variation values ≤ 19.8%) under repeatability and within-laboratory reproducibility conditions, were in accordance with the Codex Alimentarius Commission CAC/GL 71–2009 for quantitative analytical methods for veterinary drug residues in foods. Moreover, adequate identification of the compounds was provided with accurate mass measurement of both precursor and fragment ions in one single run. Finally, the developed method was applied to thirty-five powdered milk-based infant formula samples available in the Brazilian market.