Existing Laboratory Methods Research Articles

CAPILLARY PROCESSES DURING FLOODING OF LAYERED-HETEROMOGENEOUS PRODUCTIVE FORMATIONS

The paper presents an analysis of existing laboratory methods for determining capillary pressure functions used in mathematical and computer modeling of the processes of capillary impregnation of low-permeability layers of layered heterogeneous hydrophilic reservoirs during their flooding.It is shown that in existing methods for determining capillary pressure functions in rock samples using capillarimeters and high-speed centrifuges, the factor of the formation of residual oil in the pore space of the rock is not taken into account. At the same time, the processes of displacement of oil by water from productive formations and, in particular, the processes of capillary impregnation of the rock, are characterized by the processes of formation of microvolumes precisely of immobile residual oil in its pore space. Meanwhile, when conducting laboratory studies of rock samples using existing methods, another process is physically reproduced — the process of displacement of water by oil, during which microvolumes of residual water, rather than oil, are formed.This difference in the structure of the oil-water medium leads to a significant difference between the capillary pressure functions determined by traditional methods and the capillary pressure functions that control the distribution of oil and water phases in the pore space of rocks in the processes of displacement of oil from them by water pumped into the reservoir.This difference is especially significant when flooding low-permeability rocks characterized by high capillary pressure values.The work suggests possible approaches to conducting laboratory studies of rock cores that are more consistent with the structural features of the oil-water environment during flooding of productive formations.For the most complete capillary impregnation of low-permeable layers of a layered heterogeneous formation with water from quickly watered high-permeability layers, a method is proposed that consists in the fact that the water pumped into the formation must contain the minimum required amount of oil, ensuring the mobility (connectivity) of the oil phase in the watered high-permeability layers.For this purpose, water from production wells containing a certain amount of residual oil can be used for injection into the reservoir. The economic feasibility of the proposed method should be justified by the results of computer modeling of capillary impregnation processes, taking into account the described features of capillary pressure functions characteristic ofprocesses of oil displacement from productive formations during their waterflooding.

Gated nanoprobe utilizing metal-organic frameworks for identifying and distinguishing between the wild strains and the vaccine strains of brucella.

In the assay for Brucella, the identification and differentiation of wild strains and vaccine strains present a significant challenge. Currently, there aren't any commercially available product to address this issue. In this study, we have developed a novel gated nanoprobe by utilizing Metal-Organic Frameworks (MOFs) as a scaffold and hairpin DNA as a "gating switch". Specifically, Probe 1 with hairpin structure (P1h) targets a gene that is present in both wild strains Y3 (B. melitensis biovar 3) and vaccine strains A19 (Brucella abortus strains A19). We successfully applied this probe to screen positive samples of Brucella without any cross-reactivity with other substances. Additionally, we identified another specific gene exclusively found in wild strains, which serves as Probe 2 with hairpin structure (P2h) to confirm the strain type. Simultaneous detachment of both P1h and P2h from the MOFs leads to the release of Rhodamine 6G (Rho 6G) and Fluorescein (Flu), specifically indicating the presence of wild strains. If only P1h detaches and the Flu signal is detected, it suggests the presence of vaccine strains. Importantly, this method offers high accuracy, with a detection rate of 90% and a recovery rate of 94.71% to 107.65%, while avoiding cross-reactions with MO and TB. This one-step experiment provides reliable identification and differentiation of Y3 and A19, addressing concerns related to long periodicity, interference from individual variations, and the complex design of primers in existing laboratory methods. Furthermore, our approach successfully detects target 1 (T1) and target 2 (T2) at concentrations ranging from 10-6 M to 10-9 M, with a detection limit of 6.7 × 10-10 M and 6.4 × 10-10 M, respectively. Importantly, our strategy is cost-effective (around $1) and offers higher detection efficiency compared to traditional laboratory methods.

Comparison of Deep Neural Networks in Detecting Field Grapevine Diseases Using Transfer Learning

Plants diseases constitute a substantial threat for farmers given the high economic and environmental impact of their treatment. Detecting possible pathogen threats in plants based on non-destructive remote sensing and computer vision methods offers an alternative to existing laboratory methods and leads to improved crop management. Vine is an important crop that is mainly affected by fungal diseases. In this study, photos from healthy leaves and leaves infected by a fungal disease of vine are used to create disease identification classifiers. The transfer learning technique was employed in this study and was used to train three different deep convolutional neural network (DCNN) approaches that were compared according to their classification accuracy, namely AlexNet, VGG-19, and Inception v3. The above-mentioned models were trained on the open-source PlantVillage dataset using two training approaches: feature extraction, where the weights of the base deep neural network model were frozen and only the ones on the newly added layers were updated, and fine tuning, where the weights of the base model were also updated during training. Then, the created models were validated on the PlantVillage dataset and retrained using a custom field-grown vine photo dataset. The results showed that the fine-tuning approach showed better validation and testing accuracy, for all DCNNs, compared to the feature extraction approach. As far as the results of DCNNs are concerned, the Inception v3 algorithm outperformed VGG-19 and AlexNet in almost all the cases, demonstrating a validation performance of 100% for the fine-tuned strategy on the PlantVillage dataset and an accuracy of 83.3% for the respective strategy on a custom vine disease use case dataset, while AlexNet achieved 87.5% validation and 66.7% accuracy for the respective scenarios. Regarding VGG-19, the validation performance reached 100%, with an accuracy of 76.7%.

Evaluating the Feasibility of a Low-Field Nuclear Magnetic Resonance (NMR) Sensor for Manure Nutrient Prediction.

Livestock manure is typically applied to fertilize crops, however the accurate determination of manure nutrient composition through a reliable method is important to optimize manure application rates that maximize crop yields and prevent environmental contamination. Existing laboratory methods can be time consuming, expensive, and generally the results are not provided prior to manure application. In this study, the evaluation of a low-field nuclear magnetic resonance (NMR) sensor designated for manure nutrient prediction was assessed. Twenty dairy manure samples were analyzed for total solid (TS), total nitrogen (TN), ammoniacal nitrogen (NH4-N), and total phosphorus (TP) in a certified laboratory and in parallel using the NMR analyzer. The linear regression of NMR prediction versus lab measurements for TS had an R2 value of 0.86 for samples with TS < 8%, and values of 0.94 and 0.98 for TN and NH4-N, respectively, indicating good correlations between NMR prediction and lab measurements. The TP prediction of NMR for all samples agreed with the lab analysis with R2 greater than 0.87. The intra- and inter-sample variations of TP measured by NMR were significantly larger than other parameters suggesting less robustness in TP prediction. The results of this study indicate low-field NMR is a rapid method that has a potential to be utilized as an alternative to laboratory analysis of manure nutrients, however, further investigation is needed before wide application for on farm analysis.

ПРАКТИЧНІ РЕКОМЕНДАЦІЇ ЩОДО ЗАСТОСУВАННЯ МЕТОДІВ ВИЯВЛЕННЯ ФАЛЬСИФІКАТІВ У МОЛОЧНИХ ПРОДУКТАХ

An analysis was made of the types and characteristics of the influence of counterfeit products on human health, the main sources of their toxicological danger, and the state of legislative and regulato-ry documents regarding the technical conditions and requirements for the quality of dairy products in Ukraine and other countries, and the existing laboratory methods for determining their quality and safety. The necessity of introducing requirements for the types of analyzes in Ukraine into the existing regulatory documentation in the form of technical conditions is considered. It is proposed to introduce a new method of analysis to identify vegetable fat in falsified milk fat substitutes. It is proposed to focus on the composition of the sterol fraction, which highly depends on the nature of the fat: animal or veg-etable origin when evaluating the test results of dairy products. If the content of only milk fat in the sterol fraction should be only cholesterol. It is absent in vegetable fats, but other sterols are present: brassicasterin, campasterin, stigmasterol, β-sterol and others. Thus, the falsification assessment of the fat component of dairy products is established by comparing the obtained ratios of the mass fractions of methyl esters of fatty acids or their amounts with well-studied average indicators. For the practice of laboratories, it is more appropriate to determine the Reichert-Meissl number, which is one of the constants of the milk fat and characterizes the content of low molecular weight wa-ter-soluble volatile fatty acids in 5 g of fat. If for milk fat this number is from 20 to 37, then for vegeta-ble fats the Reichert-Meissl number is from 0.3 to 2.5 for corn and respectively 6-9 for coconut, 4-7 for palm kernel, 0.1-1.5 for palm fats. It is also possible to use another constant – iodine value. It charac-terizes the content of unsaturated acids in fat and makes it possible to distinguish milk fat from vegeta-ble. In this case, use the ratio of iodine number and Reichert-Meissl number, which for milk fat is 2.5, and for vegetable fats from 90.8 (palm) to 754.2 (sunflower). This technique can be effectively used to detect counterfeits of dairy products.

Development of a new high-throughput and small-size method for measuring sediment oxygen demand in lakes

Sediment oxygen demand (SOD) measurement currently requires a long preparation time and bulky experimental equipment, which represent major obstacles to conducting SOD measurements. We developed a new SOD measurement method that can be easily conducted in a shorter time than the existing laboratory method. The undisturbed sediment core was transferred into the custom-made small glass vial (inner diameter 12.8 mm, length 125 mm). The SOD sample was incubated in the dark with or without stirring the overlying water inside the vial. The change in DO concentration was measured using a non-contact fluorescent oxygen sensor, and then the SOD was calculated. For comparison and verification of the new method, SOD was also measured using a large undisturbed sediment core (inner diameter 11 cm, length 50 cm). The SOD measurements using the new method were positively correlated with the SOD measurements using the large undisturbed sediment core, suggesting that the new method is a feasible alternative to the conventional method. In the new method, many SOD measurements can be taken from a single sediment core sample. This makes it possible to reduce the uncertainty associated with the highly heterogeneous structure of the sediments, and thus the new method has great advantages in obtaining reliable SOD data. A novel high-throughput method for SOD was developed that shortens sample preparation time and improves convenience of measurement. The new method is expected to contribute substantially to the accumulation of SOD monitoring data and to make great progress in elucidating the dynamics of dissolved oxygen in lakes.

The effectiveness of methods for laboratory diagnosis of otodectosis in dogs

Otodectosis in domestic dogs is caused by ectoparasites of the species Otodectes cynotis (Hering, 1838), which parasitize on the inner surface of the auricles, the external auditory canal and the eardrum. The invasion is accompanied by severe itching, otitis, anxiety of animals, and sometimes – their death due to complications. The effectiveness of measures to combat otodectosis in dogs largely depends on the correct and accurate diagnosis of the invasion. At the same time, existing laboratory methods have different diagnostic efficiency. The aim of the study was to establish the effectiveness of mortal and vital methods of lifelong diagnosis of otodectosis in dogs. The effectiveness of modern methods of laboratory diagnosis of live and dead ticks of the species O. cynotis in dogs has been established. The most effective methods have been identified, the use of which will improve the quality of acarological research. Studies have shown that the most effective method of mortal methods was A. M. Titarenko, where a mixture of 50% aqueous solution of glycerin, dimethyl sulfoxide and 10% sodium hydroxide solution (the intensity of the invasion was 5.4 specimens of mites) was used as an illuminator. This method exceeded the intensity of invasion using the compressor method – 2 times (2.7 specimens of mites, P &lt; 0.001), the flotation method – 1.2 times (4.5 specimens of mites). At the same time, the flotation method for otodectosis in dogs was 1.7 times more effective (P &lt; 0.001) than the use of the compressor method. Of the vital methods of laboratory diagnosis of otodectosis in dogs, the most effective was the method using vegetable oil as a scraper clarifier, the intensity of the invasion was 5.9 copies. ticks. The use of this technique in terms of the number of detected otodectes exceeded the method of A.V. Alfimova (influence of elevated temperature) – 2.1 times (2.8 specimens of mites, P &lt; 0.001) and the method of M.G. Khatin (centrifugation under the influence of elevated). temperature) – 1.3 times (4.6 specimens of mites, P &lt; 0.001). In addition, the congratulatory method of M. G. Khatin in the diagnosis of otodectosis was 1.6 times more effective (P &lt; 0.001) than the method of A. V. Alfimova.

Propagation of waves with a wide range of frequencies in digital core samples and dynamic strain anomaly detection: carbonate rock as a case study

SUMMARYRecent advancements in various types of seismic measurement methods, such as sonic logging, vertical seismic profiling (VSP) and surface seismic surveys, have allowed the high-quality measurement of seismic wave propagation over a broad frequency range. To elucidate the relationship between seismic wave propagation captured by various seismic methods at widely different frequencies and in highly heterogeneous zones (e.g. fractures, vuggy zones) developed in carbonate reservoirs, laboratory measurements have been conducted over a broad frequency range. However, existing laboratory methods measure the effective properties over an entire core sample. Furthermore, there are few laboratory measurements of individual fracture stiffnesses. We propose a method to indirectly estimate the local properties caused by local anomalies (e.g. fractures) in a core sample over a broad frequency range from the dynamic elastic properties of a dry core sample using synthetic seismic waveforms generated from a digital volume of the core sample. 3-D numerical simulations were conducted over a broad frequency range using a digital core model produced by X-ray computed tomography. The proposed method was applied to numerical models and two types (fractured and vuggy) of carbonate core plugs acquired in an Abu Dhabi oil field, with the frequency ranging from 200 Hz to 100 kHz in the tests. Local strain anomalies and their frequency dependencies were successfully detected in the fractured core plug. Such frequency-dependent local responses could be associated with the micromechanics of incomplete solid–solid contacts at fractures or the heterogeneity of core samples, and thus with the frequency-dependent fracture stiffness. It was also demonstrated that the heterogeneity-induced local strain in a vuggy core plug may affect the accuracy of existing low-frequency laboratory measurements.

Experimental, algorithmic, and theoretical analyses for selecting an optimal laboratory method to evaluate working fluid damage in coal bed methane reservoirs

The existing laboratory methods have limitations that make it very difficult to select the most suitable method for obtaining precise permeability measurements for evaluating reservoir formation damage. To date, there has been no research critically addressing this issue. In this study, the permeabilities of core or cuttings samples taken from No.15 Reservoir in the Qinshui Basin before and after damage caused by drilling and fracturing fluids were randomly measured using six general laboratory methods. Their average permeability values, as well as the extent of absolute and relative formation damage, were calculated and analyzed using a simple ranking method, statistical screening algorithm, and theoretical method. The results show that, first, there is a regular distribution of absolute reservoir damage measured by the laboratory methods; and second, the application priority of permeability measurement methods for formation damage evaluation in coal bed methane reservoirs is as follows: cuttings pulse decay method > constant flow rate method > nuclear magnetic resonance method > plunger pulse decay method = pressure oscillation method = constant pressure method. The cuttings pulse decay method is therefore recommended for measuring core matrix damage, while the constant flow rate method is suggested for measuring overall damage to core samples.

Non-Destructive Early Detection and Quantitative Severity Stage Classification of Tomato Chlorosis Virus (ToCV) Infection in Young Tomato Plants Using Vis–NIR Spectroscopy

Tomato chlorosis virus (ToCV) is a serious, emerging tomato pathogen that has a significant impact on the quality and quantity of tomato production worldwide. Detecting ToCV via means of spectral measurements in an early pre-symptomatic stage offers an alternative to the existing laboratory methods, leading to better disease management in the field. In this study, leaf spectra from healthy and diseased leaves were measured with a spectrometer. The diseased leaves were subjected to RT-qPCR for the detection and quantification of the titer of ToCV. Neighborhood component analysis (NCA) algorithm was employed for the feature selection of the effective wavelengths and the most important vegetation indices out of the 24 that were tested. Two machine learning methods, namely XY-fusion network (XY-F) and multilayer perceptron with automated relevance determination (MLP–ARD), were employed for the estimation of the disease existence and viral load in the tomato leaves. The results showed that before outlier elimination, the MLP–ARD classifier generally outperformed the XY-F network with an overall accuracy of 92.1% against 88.3% for the XY-F. Outlier elimination contributed to the performance of the classifiers as the overall accuracy for both XY-F and MLP–ARD reached 100%.

A Fluorescence in Situ Hybridization (FISH) Test for Diagnosing Babesiosis.

Apicomplexan parasites of the genus Babesia cause babesiosis in humans and animals. The microscopic examination of stained blood smears, detection of serum antibodies by immunoassays, and PCR-based identification of parasite nucleic acid in blood are common laboratory methods for diagnosing babesiosis. The present study evaluated a commercially available Babesia genus-specific fluorescence in situ hybridization (FISH) test for detecting Babesia parasites in blood smears. The FISH test detected Babesia duncani and Babesia microti, two common species that cause human infections in the USA, and other Babesia species of human and veterinary importance in less than two hours. The Babesia genus-specific FISH test supplements other existing laboratory methods for diagnosing babesiosis and may be particularly useful in resource-limited laboratories.

T203. RELEVANT CLOZAPINE BLOOD LEVELS USING A POINT OF CARE TEST (POCT)

BackgroundClozapine is one of the most underused medications in psychiatry for many reasons including mandatory blood testing, fear of serious side-effects, lack of patient adherence. A critical barrier to adoption could be addressed with the ability to measure clozapine at point-of-care (POC) from a fingerstick. Current practice of clozapine measurements, however, was developed based on serum levels. Therefore, meaningful POC results must be reported as the serum equivalent. We evaluated a new immunoassay method to measure clozapine in whole blood to establish standardization to serum, and to assess the ability of the POCT to detect differences in patients’ clozapine levels compared to an existing laboratory method.MethodsA whole blood POCT (MyCare® Insite Clozapine Test on the MyCare Insite)* immunoassay was compared to liquid chromatography tandem mass-spectrometry (LC-MS/MS) in serum with 95 matched patient samples. Passing-Bablok regression was used to compare results and establish calibrator values to standardize the POCT to report whole blood results as equivalent to serum. The standardization was validated by a method comparison to LC-MS/MS with 304 samples collected from patients with schizophrenia who were being treated with clozapine. Serial blood levels were taken for 13 patients to compare deviation from baseline for POCT and LC-MS/MS results. To detect a discordant difference in clozapine levels, the difference to the preceding value was calculated for 73 sequential samples of the 86 total results. Because of high intra-patient variability changes of > ±50% were considered significant.ResultsThere was good correlation (R = 0.9) between the POCT and LC-MS/MS in the training set (N=95). Passing-Bablok statistics were: slope = 1.02, intercept = -2.3, R = 0.9, average bias -17.7 (-3.8%). The average values (± SD) were 479.7 (± 181.5) ng/mL for LC-MS/MS and 462.0 (± 199.1) ng/mL for POCT. The Passing-Bablok regression of the validation set (N=304), using the reassigned calibrator values as the training set, gave a slope = 0.971, intercept = -21.2, R = 0.9, mean values (± SD) of 445.6 (± 242.4) for LC-MS/MS and, 412.6 (± 245.7) for the POCT, average bias was -33.0 (-7.7%). Bias between POCT and LC-MS/MS for 12 individuals ranged from -22% to 22%. One patient with five sequential measurements had a total bias of -34% with 4 of 5 results, agreeing with assignment in or out of the presumptive target range of 350 – 600 ng/mL. The frequency of >±50% change in clozapine levels was <5%. Ninety percent (66 of 73) of results agreed, selectivity = 50%, specificity = 94%, positive predictive value (PPV) = 42.9%, negative predictive value (NPV) = 95.5%. Seven samples had a 50% change by one method and not the other. There was only one discrepant sample that was 66% lower with POCT.DiscussionDifferences in measurement methods are expected. The good correlation and similarity of results between the calibrator assignment training set and the validation set demonstrates the accuracy of the calibrator value assignment. The POCT was highly selective in detecting important changes in clozapine levels of more than 50% which would occur secondary to non-adherence, change in life-style habits or drug-drug interactions. The collection conditions gave consistent levels for most patients, with few large shifts in concentration, thus underestimating the PPV. These data suggest that clozapine levels can be accurately measured from a small volume of capillary blood collected via a fingerstick sample. This method makes blood sampling easier for both patients and clinical staff, and provides a result in a few minutes, at point of care. Its clinical implementation may facilitate the safe and effective use of clozapine in schizophrenia.*CE mark/US RUO

Chimerism Monitoring with Highly Sensitive and Precise Next-Generation Sequencing Assay in Patients Post-Allogeneic Hematopoietic Stem Cell Transplantation

<h3>Introduction</h3> Chimerism testing of peripheral blood and bone marrow aspirates following allogeneic hematopoietic cell transplantation (HCT) is important to evaluate engraftment kinetics and potentially early detection of disease relapse¹. NGS-based chimerism assays use SNP panels and provide standardized workflow with automated data analyses. <h3>Objectives</h3> We aim to evaluate performance of an NGS-based chimerism assay and compare it to existing laboratory method based on Short Tandem Repeat (STR) analysis. <h3>Methods</h3> Genomic DNA (gDNA) derived from PBMCs of unrelated donors were mixed at fractions ranging from 0.1% - 50% to evaluate sensitivity and specificity of the NGS-based chimerism assay in artificial genomic chimeras. 3-10 ng gDNA was used to prepare libraries with the assay kit and sequenced on Illumina MiSeq. <h3>Results</h3> Linear regression analyses of gDNA fractions (expected, observed) detected a linear signal at a minimum of 0.1% of minor gDNA in a two-gDNA chimeric mix (R²=1, average CV = 4.5%, range = 0.2-12.4). Chimeric samples with three distinct gDNAs gave linear signal as low as 0.5% of minor gDNA fraction (CV < 2%, range = 0.01-5.5%), a scenario that is clinically relevant in double-cord HCT or second HCT from different donors. The NGS-based chimerism assay was also tested on post-transplant samples derived from three HCT recipients. Results were compared longitudinally and between the two test methods at various time points (days) post transplantation. While majority results were consistent with previous data from STR, some discrepancies were observed. Patient 1, day+128, showed microchimerism (0.1%) that was undetected by STR (0%). Patient 2, day+287, showed low level (2.42%) of recipient DNA while STR reported full donor engraftment. Such clinical cases underscore the need for high sensitivity assays to more accurately quantitate donor-recipient fractions in post-HCT samples. <h3>Conclusions</h3> Using the test NGS-based chimerism assay on two and three gDNA mixes, we observe 10X greater sensitivity of minor fraction quantitation compared to current STR method. In our experience, high sensitivity, precision over a wide range of detection and robust performance with low input DNA may qualify this NGS-based chimerism assay as a potential method of choice for routine engraftment monitoring and potential early detection of disease relapse.

Characterization of Organic Layer in Oil Carbonate Reservoir Rocks and its Effect on Microscale Wetting Properties

Effective production of oil from carbonate reservoirs often requires the application of improved oil recovery technologies such as waterflooding. However, conventional waterflooding in carbonates usually results in low hydrocarbon recovery as most of these formations exhibit a complex pore throats structure and are mostly oil-wet. Therefore, improved insight into the causes of hydrophobic wetting behavior of such reservoirs is important for understanding the fluid distribution, displacement and enhancing recovery processes. The characterization of fluid-rock interactions is, however, challenging with existing laboratory methods, which are typically based on macroscale (mm) observations. In this experimental study, an advanced imaging technique, namely environmental scanning electron microscope, was applied for the comprehensive investigation of microscale (µm) wettability variations in carbonate rocks covered with organic layers. For the first time, the presence of organic layers on the sample was proved using energy dispersive X-ray mapping. Furthermore, the chemical bond of this layer and carbonate rock surfaces was determined using the transmission electron microscopy and electron energy-loss spectroscopy. The thickness of layer was estimated by using image processing software. These findings show that the application of combined microscopic techniques reveals important details about the reason of hydrophobic wetting properties of real carbonate rocks.

Efficacy of laboratory methods of diagnostic of purulent bacterial meningitis.

According to the World Health Organization, every year about 1 million cases of purulent bacterial meningitis (PBM) are registered in the world, of which 200 thousand cases end in death. Bacterial meningitis is polyethiologic, which makes the task of determining the pathogen the main in the organization of epidemiological surveillance, treatment regimens, planning of preventive and anti-epidemic measures. The quality of laboratory diagnostics has a key influence on this. The true incidence of meningitis of different etiology can be altered at low-efficiency laboratory diagnostics. This work was carried out to assess the effectiveness of existing laboratory methods for the detection of PBM pathogens: Haemophilus influenzae, Streptococcus pneumoniae and Neisseria meningitidis; as a part of the programme on sentinel surveillance of invasive bacterial diseases (IBD) carried out by the WHO regional office for Europe in a number of countries in Europe (Ukraine, Belarus), Transcaucasia (Azerbaijan, Armenia, Georgia), Asia (Uzbekistan, Kyrgyzstan, Kazakhstan) in the period 2010-2017. 2893 samples of clinical material (CSF and blood) obtained from patients with the meningeal syndrome were studied by four diagnostic methods: cultural method, latex-agglutination test, immunochromatographic test (BinaxNOW), PCR (conventional and real-time), used to identify the following pathogens: Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae. When identifying the causative agents of BM, PCR more effective than culture method is 5 times in detecting N. meningitidis; 3 times in the detection of S. pneumoniae; 4 times the detection of H. influenzae b. Latex-agglutination test and immunochromatographic test allow to increase the identification of pathogens of BM for N. meningitidis - by 35.6%; S. pneumoniae - by 67%; H. influenzae b - by 19.2%, it is possible to set them in the field and at the epidpoint if necessary. When working with clinical material from patients diagnosed with GBM, it is advisable for bacteriological laboratories to complement the culture method of microbiological diagnosis of latex-agglutination test, immunochromatographic test or PCR.

Разработка методики анализа летучих органических соединений в почве с использованием портативного хроматографа на основе микрофлюидных систем

В статье представлена реализация методики качественного и количественного анализа летучих органических соединений в почве при помощи портативного газового хроматографа на основе микрофлюидных систем. Показано что при использовании парофазного анализа и портативного газового хроматографа на основе микрофлюидных систем возможно за 120 секунд с чувствительностью до 2×10-2 мг/кг (по бензолу) определять качественный и количественный состав смеси алифатических и непредельных углеводородов, находящихся в почве, как в лабораторных, таки в полевых условиях.

A rare intercomparison of nutrient analysis at sea: lessons learned and recommendations to enhance comparability of open-ocean nutrient data

Abstract. An intercomparison study has been carried out on the analysis of inorganic nutrients at sea following the operation of two nutrient analysers simultaneously on the GO-SHIP A02 trans-Atlantic survey in May 2017. Both instruments were Skalar San++ Continuous Flow Analyzers, one from the Marine Institute, Ireland and the other from Dalhousie University, Canada, each operated by their own laboratory analysts following GO-SHIP guidelines while adopting their existing laboratory methods. There was high comparability between the two data sets and vertical profiles of nutrients also compared well with those collected in 1997 along the same A02 transect by the World Ocean Circulation Experiment. The largest differences between data sets were observed in the low-nutrient surface waters and results highlight the value of using three reference materials (low, middle and high concentration) to cover the full range of expected nutrients and identify bias and non-linearity in the calibrations. The intercomparison also raised some interesting questions on the comparison of nutrients analysed by different systems and a number of recommendations have been suggested that we feel will enhance the existing GO-SHIP guidelines to improve the comparability of global nutrient data sets. A key recommendation is for the specification of clearly defined data quality objectives for oceanic nutrient measurements and a flagging method for reported data that do not meet these criteria. The A02 nutrient data set is currently available at the National Oceanographic Data Centre of Ireland: https://doi.org/10.20393/CE49BC4C-91CC-41B9-A07F-D4E36B18B26F and https://doi.org/10.20393/EAD02A1F-AAB3-4F4E-AD60-6289B9585531.

Laboratory Procedure for Rapid Screening of Reverse Osmosis Membrane Anti-Scalants

A reliable and rapid laboratory procedure was developed for rapid screening of reverse osmosis (RO) membrane anti-scalants and compared with existing laboratory methods. This laboratory procedure consists of two parts according to the characteristics of screening RO membrane anti-scalants: preliminary screening of anti-scalants by static method and further by dynamic methods based on the result of static method. Conductivity method, critical pH method and turbidity method were selected as the methods for preliminary screening of RO anti-scalants, and drainage gradient method and dose gradient method were chosen as the dynamic methods for further screening RO anti-scalants.

Subsidiary methods of pregnancy diagnosis in diary cattle – alternative for the future

Early pregnancy diagnosis in cows is one of the key elements of effective reproduction management of this species. Still imperfect effectiveness of procedures performed motivates veterinarians for further exploration of new techniques for the diagnosis of pregnancy and their new application. The following article aims to give existing laboratory methods and possibilities for their use in the diagnosis of pregnancy before the 3rd day of insemination. In particular, substances that can be identified as soon as possible after insemination are presented: early pregnancy factor (EPF), progesterone (P4), estrogen sulfate and pregnancy-associated glycoproteins (PAG). A detailed description of these substances and their role in the formation and maintenance of celibacy in cows are given. The possibility of using laboratory methods in modern milk reproduction protocols is shown. From the perspective of modern literature sources, the most effective laboratory methods for diagnosing pregnancy in dairy farming today are the definition of an early pregnancy factor (EPF) and pregnancy-associated glycoproteins (PAG). Description of the methods available on the market and a new compilation (protocols) above techniques may be of interest for veterinarian involved in cattle reproduction. Despite the rapid development and the presence of more and more effective ultrasound devices, a practical veterinarian should not forget about the existence of indirect methods of diagnosis of pregnancy, which in large herds can significantly improve the economic conditions for the management of reproduction of cows in the future.

Connect 4: A Novel Paradigm to Elicit Positive and Negative Insight and Search Problem Solving.

Researchers have typically defined insight as a sudden new idea or understanding accompanied by an emotional feeling of Aha. Recently, examples of negative insight in everyday creative problem solving have been identified. These are seen as sudden and sickening moments of realization experienced as an Uh-oh rather than Aha. However, such experiences have yet to be explored from an experimental perspective. One barrier to doing so is that methods to elicit insight in the laboratory are constrained to positive insight. This study therefore aimed to develop a novel methodology that elicits both positive and negative insight solving, and additionally provides the contrasting experiences of analytic search solving in the same controlled conditions. The game of Connect 4 was identified as having the potential to produce these experiences, with each move representing a solving episode (where best to place the counter). Eighty participants played six games of Connect 4 against a computer and reported each move as being a product of positive search, positive insight, negative search or negative insight. Phenomenological ratings were then collected to provide validation of the experiences elicited. The results demonstrated that playing Connect 4 saw reporting of insight and search experiences that were both positive and negative, with the majority of participants using all four solving types. Phenomenological ratings suggest that these reported experiences were comparable to those elicited by existing laboratory methods focused on positive insight. This establishes the potential for Connect 4 to be used in future problem solving research as a reliable elicitation tool of insight and search experiences for both positive and negative solving. Furthermore, Connect 4 may be seen to offer more true to life solving experiences than other paradigms where a series of problems are solved working toward an overall superordinate goal rather than the presentation of stand-alone and un-related problems. Future work will need to look to develop versions of Connect 4 with greater control in order to fully utilize this methodology for creative problem solving research in experimental psychology and neuroscience contexts.