Laboratory Samples Research Articles

Epidemiology of ESKAPEE Complex at Veracruz Children’s Hospital during 2023

Abstract Introduction The ESKAPEE complex comprises bacterial species known for their propensity to develop multiple mechanisms of resistance against antibiotics. The elevated rates of mortality and morbidity associated with these microorganisms, along with the challenges posed by their treatment, have transformed them into a significant concern in global public health. However, in Mexico, the prevalence of the ESKAPEE complex in pediatric patients within tertiary care hospitals remains understudied compared to adults. Materials and methods A cross-sectional, retrospective, and descriptive study was conducted, encompassing 179 bacteria belonging to the ESKAPEE complex. These bacteria were isolated from pediatric patients between January and December 2023 at Veracruz Children’s Hospital. Laboratory samples were processed using the VITEK 2.0 system, and descriptive statistical analyses were performed using SPSS v22 software. Results A total of 179 antibiograms were analyzed, with 55.1% corresponding to male patients. The most prevalent age group among pediatric patients was school children (5 to 11 years old), comprising 20.2% of the sample. Blood culture was the most frequently sampled site, representing 35.4% of cases. Klebsiella pneumoniae emerged as the most common bacterium, accounting for 22.5% of isolates. The Pediatric Emergency Department was the primary area from which samples were obtained, constituting 18.5% of the total. Conclusions Klebsiella pneumoniae was the most frequently isolated bacteria inside de hospital in 2023, especially among school-aged patients, followed by E. coli, which coincides with reports in the literature from various countries around the world. Key messages • Establishing a national surveillance network within public health institutions is imperative, where ESKAPEE complex microorganisms are reported. • Knowing the epidemiological profile of the ESKAPEE complex will favor the diagnosis and intentional search for infections with greater etiological certainty.

A convenient reduction method for the detection of low concentration free available chlorine——utilizing sodium sulfite as a quencher

Chlorine, serving as the mainstream disinfectant, can react with dissolved organic matter (DOM) to form undeserved disinfection by-products (DBPs). Free available chlorine (FAC) concentration is crucial to ensure effective disinfection while minimizing the formation of toxic DBPs. In this study, we propose a convenient method using sodium sulfite (Na2SO3) to reduce oxidized chlorine in FAC. The molar concentration of reduced chloride ion (Cl−) was quantified directly by ion chromatography to reflect FAC concentration. Compared with common FAC detection techniques including DPD colorimetry, iodometric, and UV methods, this novel reduction method exhibits a lower detection limit and is more resistant to interference. Common water matrices, such as DOM and anions did not affect the method accuracy (< 3.6%). Furthermore, carbonaceous DBPs (C-DBPs) like regulated trihalomethanes and halogenacetic acids, unregulated aromatic chlorophenols, did not interfere with the determination of FAC by using this reduction method. This lack of interference can be attributed to the low redox potential of Na2SO3, which does not readily react with these C-DBPs. However, nitrogenated DBPs (N-DBPs) like dichloroacetonitrile displayed slight interference (the effect of common dichloroacetonitrile concentration in water on FAC was less than 0.0007 μM). This suggests that this method is well-suited for determining FAC in chlorination processes where the C-DBPs predominated. Overall, the reduction method enables precise determination of FAC and proves valuable in assessing residual chlorine levels in both laboratory and real disinfected water samples dominated by C-DBPs.

The effect of complex extra-furnace treatment of metal melts on the formation of non-metallic inclusions in large-sized ingots

Abstract The article presents the results of studying non-metallic inclusions (NI) after extra-furnace treatment of the 13Cr9Mo2Co1NiVNbNB steel melt to produce large-sized ingots. The objects of the study were laboratory samples melted in a semi-industrial induction furnace with the capacity of 20 tons (the first batch), and samples obtained after melting in an electric arc furnace with the capacity of 120 tons, followed by modification and double vacuuming (the second batch).&amp;#xD;Previously, using the Fact Sage software, modeling of the NI formation processes was carried out. The data were obtained on the possible NI composition and amount in this steel.&amp;#xD;Studying NIs (the composition, the contamination index, inclusion parameters) was carried out on an ASPEX Explorer electron microscope using the method of automatic X-ray spectral analysis of particles (Automatic Features Analysis, AFA). It was established that in the samples of the first batch, the main part of the NIs consisted of chromium- and manganese-containing oxides: chromium-manganese spinels (Cr-Mn-O and Mn-Cr-Si-O groups), which occupy more than 94% of the total area of the NIs. In the samples of the second batch, the main part of the Nis was represented by Cr-Mn-O; Al-Cr-O; Cr-Al-Mn-O systems.&amp;#xD;It was shown that the average size of non-ferrous substances in the samples of the laboratory batch and in industrial samples after extra-furnace treatment differs slightly (5-12%), however, the contamination index in industrial samples after vacuum treatment and especially after modification and repeated vacuum treatment was reduced by more than 10 times. The results obtained allow recommending vacuum treatment and complex modification with calcium and boron as measures to prevent the formation of non-ferrous metals and to improve metallurgical quality when smelting large ingots using complex alloy steels.&amp;#xD;

A Descriptive Study: Evaluation of Delayed Laboratory Testing in Emergency Room

Precision, accuracy, and short turnaround time (TAT) are important to improve the quality and effectiveness of laboratory services in the Emergency Room (ER). Several studies reported an average of 60% the ratio of anticoagulant to sample is not appropriate, lysis, and clotted samples occurred in the pre-analytical part. This part consisted of the request/registration of laboratory tests, patient preparation, specimen collection, and transportation to the central laboratory. The aim of this research is to evaluate the cause of the long TAT for laboratory research so as to obtain problem solving based on the target. This observational study was conducted in 2021 at the ER laboratory outlet. Observations were made started from the workload carried out by the laboratory technician, sample registration, and data collection from the Laboratory Information System (LIS). The study obtained 14.709 samples from the LIS at the Clinical Pathology Department, Cipto Mangunkusumo Hospital. The highest sample rejection rate was from the ER laboratory outlet due to specimen lysis (2.79%). The average time required for re-collecting specimens was around 2-2.5 hours. This rejection was below the minimum quality standards based on the International Federation of Clinical Chemistry (IFCC). Other problems include the limited number of medical laboratory experts compared to the workload also inefficient Computerized Physician Order Entry (CPOE) registration methods. The main problem of delayed laboratory testing in the emergency department is the pre-analytical part including sample registration and rejection specimens. That rejection mostly comes from lysis specimens, which caused invalid laboratory result.

Analytical optical methods for measuring organic peroxides and hydroperoxides: An evaluation

Hydrogen peroxide, organic peroxides and hydroperoxides exhibit high reactivity and play a pivotal role in atmospheric chemistry. These compounds are formed during the oxidation of volatile organic compounds in both gaseous and aqueous phases, particularly under low NOx conditions. Their significant contribution to the mass of secondary organic aerosols (SOA) is well-documented, and they are believed to have significant health implications. Several spectrophotometric methods have been employed to measure SOA-bound peroxides in laboratory samples, but systematic comparisons are lacking. In this study, we have assessed the advantages and limitations of these methods, including the traditional and microwave-assisted iodometric methods, the 4-nitrophenyl boronic acid assay (NPBA), and the Fenton reaction-assisted ferrous-xylenol (FOX2) assay. Besides, a comprehensive evaluation of these methodologies was conducted for the first time across a substantial cohort of commercial peroxides and hydroperoxides, employing diverse solvents (namely, water, 1-propanol, acetonitrile, methanol and chloroform) to provide broader insights compared to previous work. Ultimately, the four methods were applied and compared for peroxide determination in laboratory-generated SOA resulting from gas-phase ozonolysis of α-pinene. This study opens new opportunities for future mechanistic investigation into SOA formation and reactivity.

High-Temperature Creep Resistance of FeAlOY ODS Ferritic Alloy.

A significant effort in optimizing the chemical composition and powder metallurgical processing led to preparing new-generation ferritic coarse-grained ODS alloys with a high nano-oxide content. The optimization was aimed at high-temperature creep and oxidation resistance at temperatures in the range of 1100-1300 °C. An FeAlOY alloy, with the chemical composition Fe-10Al-4Cr-4Y2O3 (wt. %), seems as the most promising one. The consolidation of the alloy is preferably conducted by hot rolling in several steps, followed by static recrystallization for 1 h at 1200 °C, which provides a stable coarse-grain microstructure with homogeneous dispersion of nano-oxides. This represents the most cost-effective way of production. Another method of consolidation tested was hot rotary swaging, which also gave promising results. The compression creep testing of the alloy at 1100, 1200, and 1300 °C shows excellent creep performance, which is confirmed by the tensile creep tests at 1100 °C as well. The potential in such a temperature range is the target for possible applications of the FeAlOY for the pull rods of high-temperature testing machines, gas turbine blades, or furnace fan vanes. The key effort now focuses on expanding the production from laboratory samples to larger industrial pieces.

Electrochemical molecularly imprinted polymer sensor for simple and fast analysis of tetrodotoxin in seafood

Tetrodotoxin (TTX) is a marine biotoxin whose biosynthesis is associated with the pufferfish. Its distribution is primarily focused in Asian and tropical marine areas. Currently, this group of toxins is classified as emerging in Europe, and its presence could be related to climate change. This incidence has prompted the European Union, with the European Food Safety Authority, to establish control and monitoring mechanisms for TTX in marine products in Europe. In this context, the development of analytical tools capable of ensuring the safety of food products, especially seafood and fish, is a crucial task. This study describes the development of a molecularly imprinted polymer (MIP) based electrochemical sensor for the analysis of TTX. The MIP was synthesized through the electropolymerization of a functional monomer, ortho-phenylenediamine in the presence of a dummy template, voglibose. The MIP sensor was constructed on a screen-printed gold electrode and characterized by cyclic voltammetry. Differential pulse voltammetry, using a redox probe ([Fe(CN)6]3-/4-), was used in the analysis protocol. The developed sensor exhibited a linear response between 5.0 μg mL−1 and 25.0 μg mL−1, with a limit of detection of 1.14 μg mL−1. Its high imprinting efficiency conferred outstanding selectivity towards TTX. The sensor's applicability was confirmed through recovery assays on spiked mussel samples, achieving recoveries of 81.0 %, 110.2 %, and 102.5 % for external standard addition at 30.0, 44.0, and 60.0 μg kg−1, respectively, with relative standard deviations below 15 %. These results are comparable to those obtained using Hydrophilic Interaction Liquid Chromatography coupled with Tandem Mass Spectrometry, a validated method carried out by the European Reference Laboratory for Marine Biotoxins. Thus, the MIP sensor represents a portable, simple, and fast tool with essential analytical functionalities for the sampling phase and pre-selection of laboratory samples for analysis.

EFFECT OF DRYING SPEED ON THE DESATURATION OF SWELLING ROCK

The paper presents the results of a numerical study of the influence of drying speed and hydraulic conductivity of swelling rock on the development of the desaturated zone. Swelling rock refers to natural material in which montmorillonite is the predominant type of mineral. Previous tests have unequivocally shown that a fully saturated swelling rock with a high swelling potential will not swell when wetted with water of the same chemical composition as the pore water. The swelling potential can be activated only after the desaturation of the swelling rock. The geohazard of swelling of such materials represents a very serious problem. The behavior of swelling rock is modeled as a combined hydraulic-mechanical process that includes vertical one-dimensional water flow in saturated and unsaturated conditions, with a change in the volume due to a change in the water content. As part of previously conducted laboratory research, a model of swelling was developed, which realistically represents the behavior of swelling material at the level of laboratory samples. With the developed model, it is possible to forecast the changes in moisture content that will occur during drying at the depth of the desaturated zone. Numerical simulations have clearly shown that the depth of the desaturated zone depends on the drying speed, that is, that significant depths of the desaturated zones can only be realized at low and long-term drying speeds. With the increase in the hydraulic conductivity of the swelling rock, the depth of the desaturated zone increases, and the time required for the development of such a zone increases to the same extent.

9324 X-Linked Hypophosphatemic Rickets (XLH): Experience Argentina

Abstract Disclosure: E. Giacoia: Research Investigator; Self; Ultragenyx. A.C. Cantó: Research Investigator; Self; Ultragenyx. M.C. Balonga: Research Investigator; Self; Ultragenyx. Introduction: XLH is a genetic disease characterized by rickets and osteomalacia caused by pathogenic variants in PHEX with disruptions in bone mineral homeostasis. In adults, the deformities described in childhood persist, in addition to osteomalacia, pain, stiffness, enthesopathies, arthrosis, delayed fracture consolidation and hypoacusia1,2.Objective: To describe the clinical, biochemical characteristics and complications such as kidney stones, hypoacusia, enthesopathy and type of mutation (isolated or familiar).Materials and methods: Descriptive and analytical study. 10 patients diagnosed with XLH were analyzed and evaluated from January to December 2023. Laboratory samples and complementary studies were carried out. The PHEX gene mutation was searched. Informed consents were obtained. Results: P: Phosphate, Ca: Calcium, 25OHD: Vitamin D3/10 patients had kidney stones, 4/10 hypoacusia, 4/10 enthesopathies.3/10 were de novo mutations and rest were familial.Conclusions: We observed a tendency towards hypophosphatemia and slightly increased PTH values. We consider that the experience acquired through follow-up consultations is the best tool to advance medical knowledge and thus achieve early diagnosis, access to medical treatment and multidisciplinary teamwork for improving the quality and survival of life of patients with this rare disease. Reference: (1) Juan Guillermo Cardenas-Aguilera et al. Expert Consensus on evidence-based recommedations for the diagnosis, treatment, and follow-up of X-linked hypophosfatemic rickets (XLH). Revista colombiana de nefrología, vol 11, number 1, marzo 20242. Andrea Trombetti et al. Interdisciplinary management of FGF23-related phosphate wasting syndromes: a Consensus Statement on the evaluation, diagnosis and care of patients with X-linked hypophosphataemia. Nat Rev Endocrinol. 2022 Jun;18(6):366-384. Presentation: 6/1/2024

B-268 Detection of xylazine in fentanyl-positive urine drug screen specimens using a quantitative LCMS/MS method

Abstract Background Fentanyl, a synthetic opioid used clinically for severe pain management, sedation, and as a perioperative analgesic, has been at the forefront of fatal drug-involved overdoses for almost a decade. Xylazine, an α-2 adrenergic receptor agonist, is an increasingly common adulterant in illicitly manufactured fentanyl products and analogs. Given its class, xylazine is non-responsive to naloxone, an opioid receptor antagonist used to reverse opioid overdose. Importantly, the U.S. Drug Enforcement Administration reported xylazine in 23% of seized fentanyl powders and 7% of fentanyl pills; additionally, a recent study by Kariisa et. al. identified an increase of xylazine presence in fatal fentanyl-involved overdoses (2.9% in January 2019 to 10.9% in June 2022) across twenty states.1 Collectively, these trends indicate a need for increased surveillance of xylazine in overdose-presenting patients to inform appropriate clinical responses. In this study, we developed a sensitive LC-MS/MS method for xylazine quantitation and used it to determine xylazine presence in our fentanyl positive patients. Methods An LC-MS/MS method for quantitation of xylazine from urine samples was developed using a Waters Xevo TQ-XS and reversed-phase CORTECS C8 2.7 µm column. MRMs and optimal MS tuning parameters were generated for xylazine and xylazine-d6 via IntelliStart, with transition ions of 221.18→90.04 (Quan) and 221.18→136.31 (Qual) selected for xylazine quantitation against a 227.23→89.98 xylazine-d6 transition as an internal standard. An LC method was developed using water (2 mM Ammonium Acetate; 0.1% Formic Acid v/v) and methanol (2 mM Ammonium Acetate; 0.1% Formic Acid v/v) gradient for a 4-minute runtime. Calibrators were prepared by addition of the pure drug to water, while QCs were prepared using healthy volunteer urine that was confirmed negative in a routine urine drug screen (UDS). Calibrators were value-assigned using a reference laboratory. A simple processing method consisting of the addition of 200 µL methanol containing 25 ng/mL xylazine-d6 to 50 µL of standards, QCs, or urine was used for sample preparation. Remnant fentanyl-positive patient samples (determined by ARK Fentanyl II Immunoassay - Abbott Architect C16000 analyzer) submitted for routine UDS evaluation were collected for xylazine analysis. Results Using custom xylazine standards, the method yielded a linear range from 2 ng/mL to 500 ng/mL with an average R2 of 0.9995 across runs (n = 12). The LLoQ for this assay was 2 ng/mL with a CV of 18.1%. The intra-assay CVs were &amp;lt; 5.0% and inter-assay CVs were &amp;lt; 15.0%. Of preliminary patient samples tested (n = 25), xylazine was detected in 32% of fentanyl-positive samples, ranging in concentration from 2.8 ng/mL to 192.8 ng/mL with an average of 64.8 ng/mL. Conclusions Here we report a simple LC-MS/MS method for quantitation of xylazine in remnant fentanyl-positive UDS specimens by LC-MS/MS. Preliminary testing revealed a xylazine positivity rate of 32% in fentanyl-positive patients. Uncomplicated sample work-up makes this method applicable to xylazine surveillance in all UDS-positive patient samples in high-throughput clinical laboratories. Reference: 1. Kariisa M, et. al. “Illicitly Manufactured Fentanyl-Involved Overdose Deaths with Detected Xylazine.” MMWR Morb Mortal Wkly Rep 2023;72:721-727.

Multi-scale neural network for accurate determination of the ash content of coal flotation concentrate using froth images

Flotation concentrate quality is strongly correlated with its froth. Therefore, froth images can be used to determine coal concentrate quality. Earlier studies on using coal flotation froth images to determine concentrate ash content ignore the multiscale characteristics of the images. This paper proposes a multiscale neural network (MSNet) to tackle this challenge. The MSNet model can process images with a wide range of resolutions and extract the image features from multiple scales for quality prediction. The model is validated using laboratorial and industrial datasets. Results show that the MSNet correlates with the laboratorial and industrial samples with R2 values of 0.9430 and 0.8288, respectively. The accuracy was further improved by transfer learning technique, resulting in R2 values of 0.9572 and 0.8647 for laboratorial and industrial samples, respectively. These results exhibit the good adaptability of the proposed MSNet. They also indicate that our MSNet is promising in real-world applications, promoting cleaner and more efficient coal production

Enhancing Laboratory Sample Collection Efficiency through Laboratory Information Systems: Insights into Optimal Despatch Rider Management

Effective administration of dispatch riders is crucial for delivering reliable diagnoses and research results by enabling prompt and precise sample collection. Laboratory Information Systems (LIS) offers a solution to enhance the efficiency and organization of dispatch riders in laboratory settings. Thus, the main objective of this study is to provide insights and knowledge on the potential benefits of implementing LIS to optimize the management of dispatch riders and enhance the efficiency of sample collection. An analysis of previous research findings illustrates the varied benefits of using LIS in improving key performance indicators such as turnaround time, mistake rates, and coordination of dispatch riders. The LIS platform serves as a centralized system for managing and allocating sample collection jobs, minimizing scheduling conflicts, and optimizing dispatch rider routes. Real-time tracking capabilities enable laboratory management to monitor dispatch rider locations and sample collection progress, facilitating enhanced coordination and resource allocation. Furthermore, LIS-generated data analytics provide valuable insights into sample collection patterns, enabling proactive management strategies to mitigate potential bottlenecks. Integration of LIS into payroll systems allows for automated compensation calculation based on dispatch rider performance metrics, ensuring fair and transparent pay rates. Studies consistently demonstrate that adequate compensation positively impacts dispatch rider motivation and sample collection effectiveness. This study highlights the vital importance of LIS in enhancing dispatch rider administration for efficient sample collection operations. It provides insights for laboratory managers and policymakers to optimize the potential of LIS to improve operational performance, facilitate patient care, and advance research outcomes.

Theory of similarity and ultrasonic testing

Application of similarity theory (dimensional analysis) to ultrasonic (UT) testing is discussed using as an illustration the example of concrete blocks. The concept of dimensional analysis makes it possible to represent a physical system via a minimal set of variables, the so-called π groups, which are the dimensionless quantities. These dimensionless parameters, characterizing the respective phenomenon, should have approximately equal values for the real object and for the model. Small concrete samples have been tested in the lab conditions using various UT probes and techniques. Two dimensionless criteria, valid and similar for the real field case and for the laboratory samples, have been introduced: total attenuations of UT waves and ratios of void size to the UT wavelength. To get total attenuations in the field conditions for thick concrete block, similar to the total attenuations measured in lab experiments on small samples, one should apply the low-frequency UT waves 60-100kHz. However, these UT waves will be able to reliably detect only the large inhomogeneities (e.g. voids), whose size is about half of the used UT wave, i.e. inhomogeneities with dimensions larger than 20-40mm.

A Simple Eco-Friendly HPLC-PDA Method for the Simultaneous Determination of Paclitaxel and Seliciclib in Plasma Samples for Assessing Their Pharmacodynamics and Pharmacokinetics in Combination Therapy for Uterine Sarcoma.

Background/Objectives: Uterine sarcoma, a rare cancer originating in the smooth muscle of the uterus, exhibits high rates of recurrence and metastasis. It represents one of the most challenging types of cancer due to its chemorefractory nature, showing little response to conventional chemotherapy methods and displaying a relative survival rate of 30-40%. A potentially promising approach for treating uterine sarcoma involves combination therapy with paclitaxel (PAC), a microtubule-targeting agent, and seliciclib (SEL), a cyclin-dependent kinase inhibitor. SEL has been identified as a drug that can enhance the effectiveness of PAC through synergistic effects. To further refine this treatment strategy, an efficient analytical tool capable of simultaneously measuring the concentrations of PAC and SEL in blood plasma is needed. This tool would make it easier to study the pharmacokinetic interactions of potential drugs and assist in monitoring therapy when administering this combination treatment. Regrettably, a method meeting these specific requirements has not been documented in the existing literature. Methods: This article introduces the first HPLC technique employing a PDA detector to concurrently measure PAC and SEL levels in plasma. The methodology underwent validation in accordance with the ICH standards for validating bioanalytical methods. Results: The method exhibited linearity in the concentrations ranging from 0.8 to 100 µg mL-1 for both PAC and SEL. The limits of quantification were determined and found to be 1.34 and 1.25 µg mL-1 for PAC and SEL, respectively. All the other validation criteria conformed to the ICH validation standards. The HPLC-PDA method was successfully employed to quantify both PAC and SEL in plasma samples with a high level of reliability (in terms of accuracy and precision). The eco-friendliness of the approach was verified using three thorough assessments. This technique serves as a valuable asset in establishing the correct dosage and administration schedule for the combined treatment involving PAC and SEL, ensuring the desired therapeutic effects and safety in managing uterine sarcoma. Conclusions: The proposed HPLC-PDA method is the first reliable and eco-friendly method developed to simultaneously determine PAC and SEL in high-throughput plasma samples in clinical laboratories.

Prevalence and associated risk factors of staphylococcus aureus and methicillin-resistant staphylococcus aureus isolates obtained from patients seeking treatment in Nakuru county referral and teaching hospital, Kenya

Staphylococcus aureus is a pathogenic bacterium that can evolve rapidly to methicillin-resistant Staphylococcus aureus (MRSA). MRSA is a global health concern that is associated with significant morbidity and mortality. This study was to determine the prevalence and Associated Risk Factors of staphylococcus aureus and MRSA isolates obtained from patients seeking treatment in Nakuru County Referral and Teaching Hospital. A descriptive cross-section study design was used with a laboratory experimental component and it was carried out in Nakuru County Referral and Teaching Hospital, Kenya. A total of 354 laboratory samples were randomly collected from different laboratory samples/sites: blood, urine, wound, nasal swabs, pus, tissue, abscess, sputum, ear swabs, as well as cerebrospinal fluid (CSF) culture, skin swabs and synovial fluid culture over a period of six months. These samples were tested for presence of staphylococcus aureus and MRSA isolates using Culture methods and Antibiotic Sensitivity Tests. The study analyzed 354 participants, with a median age of 35 years. Most participants (56.7%) were from medical wards, 20.4% from outpatient clinics, and 11% from Diabetic Care Centre. Staphylococcus aureus was found in 7.1% of samples, with MRSA present in 2.3%. Other isolated organisms included Coagulase Negative Staphylococci (7.1%), E. coli (6.8%), Proteus spp. (5.1%), and Pseudomonas spp. (5.9%). The prevalence of MRSA among the participants is low.

СТЕНОВЫЕ МАТЕРИАЛЫ ПОЛУСУХОГО ПРЕССОВАНИЯ НА ОСНОВЕ ГРАНУЛИРОВАННЫХ ИЗВЕСТНЯКОВЫХ ОТХОДОВ КАМНЕДОБЫЧИ

this article is devoted to the study of the processes of granulation of raw materials mixtures from limestone waste of stone mining and Portland cement and the production of wall materials based on them by semi-dry pressing. The optimal humidity-time parameters of the manufacture of granules were determined, laboratory samples of wall materials from granular mixtures with different contents of Portland cement were made. It was found that the compressive strength of samples from granulated raw materials exceeds the strength of samples from non-granulated raw materials by 3-12%. Subject of research: semi-dry pressed wall materials based on granular limestone waste from stone mining Materials and methods: Nummilite limestone waste from the Skalistoe deposit (Crimea) and Portland cement PC 500 DO from the Novorossiysk Cement Plant were used for the study. The physical and mechanical properties of the prototypes were determined by standard methods. Results: Experiments have shown that the compressive strength of samples made from granules containing 5-15% Portland cement and 85-95% of stone mining waste exceeds the strength of samples from non-granulated raw materials by 3-12%. Conclusions: The use of granular limestone waste from stone mining as the main component for the production of wall materials by semi-dry pressing makes it possible to increase their strength characteristics. The addition of Portland cement in certain proportions (5-15%) improves the strength characteristics of materials. Further research can be aimed at optimizing the composition of materials, studying their durability and adapting the production process to industrial scales.

Unnecessary repetitions of C-reactive protein and leukocyte count at the emergency department observation unit contribute to higher hospital admission rates.

The aim of the present study was to assess the effect of repeated laboratory measurement of C-reactive protein (CRP) and leukocyte count on the decision whether to admit or dicharge the patient with localized infections who received antibiotics at the Emergency Department (ED) observation unit. Adult patients with respiratory, urinary tract and abdominal infections, observed at the ED after antibiotic administration, in whom repeated measurements of CRP and leukocyte count were performed within 24 h, were included. They were initially grouped as planned discharge, planned admission and unclear attitude towards admission. Initial and repeated CRP and leukocyte count results, clinical dynamics (improvement, worsening, unchanged) and clinical decision about discharge or admission, were recorded. A total of 1,038 patients were eligible for inclusion. No significant differences in initial CRP and leukocyte count values were observed, nor any association of CRP and leukocyte count changes with clinical dynamics. Among 504 patients eligible for discharge at second laboratory sampling according to clinical dynamics, 54.4 % were further observed or admitted. Discharged patients had an average negative absolute (p<0.001) and relative CRP change (p=0.002). Clinical dynamics, first and second CRP results and absolute CRP change were independently associated with the decision to discharge or further observe/admit. Schematic repetitions of CRP and leukocyte count at the ED observation unit are common, regardless of patients' clinical condition. Clinical judgment remains the main guiding factor to admit or discharge the patient, but repeated CRP testing influences the final decision, contributing to higher admission rates.

Spectral induced polarization (SIP) measurements across a PFAS-contaminated source zone

There is a need to develop field-scale, in situ screening technologies for assessing variations in aqueous film-forming foam (AFFF) concentrations in soils at former fire training and storage sites. Field-scale Spectral Induced Polarization (SIP) geophysical measurements were acquired on a transect crossing an AFFF source zone. Soil samples were acquired to determine variations in poly- and per-fluoroalkyl substances (PFAS) concentrations in soils, characterize soil texture, and create triplicate soil columns for laboratory SIP measurements. Field and laboratory observations show that SIP measurements are sensitive to the concentration of AFFF constituents associated with soil pore surface area. The specific polarizability and the phase of the SIP measurements for the laboratory samples were linearly correlated with total soil-sorbed PFAS concentration. The phase from the field SIP measurements was highest over the location of maximum PFAS concentration measured on the laboratory samples. However, a significant correlation between field-measured phase and laboratory-measured total PFAS concentration still needs to be established. These observations, along with the demonstrated sensitivity of the SIP response to the removal of soil PFAS using a methanol wash procedure, support the case for SIP characterization of AFFF source zones.

Determination of Aloin A, Aloin B, and Aloe-Emodin in Raw Materials and Finished Products Using HPLC Multi-Laboratory Validation Study, AOAC 2016.09, Final Action Status.

A multi-laboratory validation study was performed on AOAC Official Method of Analysis (OMA) 2016.09, for final action. Eight different laboratories throughout the world participated in the study tested the same set of 6 different laboratory samples of raw materials (commercial) and formulated products (commercial), and all the laboratories successfully generated results within the acceptance criteria. The intention of the study was to evaluate specificity, precision (variation), linearity/range, system suitability, limit of detection (LOD), and limit of quantitation (LOQ) by multiple laboratories to satisfy the requirement of moving the OMA 2016.09 to the final action status. Accuracy and ruggedness were already validated in earlier work of single laboratory validation (1), and it was not necessary to include these validation parameters in the multi-laboratory validation study. Laboratory samples containing Aloe were sent out to participating laboratories. Each lab followed AOAC 2016.09 (First Action status) to analyze contents of aloin A, aloin B, and aloe emodin using high performance liquid chromatography (HPLC) instrument. The results generated by each laboratory were collected and evaluated. The specificity results show that blank and matrix chromatograms do not contain major interfering peaks on the retention time of aloin A, aloin B, and aloe-emodin. The precision (variation) results of duplicated preparations are not more than 0.05 parts per million (ppm) different. The linearity/range results from six standards (10 parts per billion (ppb), 20 ppb, 40 ppb, 80 ppb, 160 ppb, and 500 ppb) have correlation coefficient (R) value of ≥ 0.999. The system suitability results meet the acceptance criteria to show the instrument validity. The limit of detection (LOD) results show that the signal-to-noise (S/N) ratio of 10 ppb standards for all three components are about 3. The limit of quantitation (LOQ) results show that the S/N ratio of 20 ppb standards for all three components are about 10. The validation parameters (specificity, precision (variation), linearity/range, system suitability, LOD, and LOQ) have been successfully analyzed, and it shows that the test method is suitable for its intended use. The test method has been successfully validated by the eight different laboratories around the world (US, UK, Germany, and Canada). Each of the laboratory is managed independently by the site lab management team. This multi-lab study validated the method of Determination of Aloin A, Aloin B, and Aloe-Emodin in Raw Materials and Finished Products Using high performance liquid chromatography (HPLC), and the method fits for its intended purpose.

Recognition and Characterization of Nanoscale Phases: Modulus Mapping of Asphalt Film in Pavement Mixture Cores.

The objective of this study is to recognize and characterize the nanoscale phase modulus mapping of the asphalt film in pavement mixture cores using atomic force microscopy quantitative nanomechanical technology. The pavement core samples from the upper and middle layers of four highways and laboratory samples were taken as the research object. The phase modulus-macro property correlation of recovered asphalt was analyzed using mathematical statistics. The results showed that the pavement core samples had more significant multi-phase and diversified phase characteristics compared to lab samples. This indicated that the asphalt in the pavement core had an obvious phase separation phenomenon due to aging. The phase modulus of each sample was distributed across a relatively wide numerical range, and there were also many numerical points with large fluctuations. Especially for the mixture sample containing SBS (Styrene-Butadiene-Styrene)-modified asphalt, the phase modulus distribution mappings presented a multi-peak phenomenon. Hence, considering the distribution characteristics of the data, the box plot method was introduced. Compared with quantified results from laboratory samples, the phase modulus of SBS-modified asphalt increased by 0.96 times, 1.18 times and 1.15 times, and that of base asphalt increased by 0.59 times, 0.56 times, 0.42 times, 1.24 times and 0.39 times, respectively. This indicates that the aging degree of asphalt in the upper layer was generally greater than that of the asphalt in the middle layer and that there was an aging gradient in the direction of pavement depth. All points were within the 95% confidence band in terms of correlation fitting, indicating a better fitting effect between phase modulus and complex shear modulus, as well as between phase modulus and penetration. This research provides innovative ideas for future multi-scale numerical simulation and cross-scale performance model development of asphalt binders.