Reference Samples Research Articles

Identification of chemical components in Qinggu San reference sample of classial prescription based on UHPLC-Q/Orbitrap HRMS combined with molecular network technology

The method of ultra-high performance liquid chromatography-quadrupole-electrostatic field orbitrap high-resolution mass spectrometry(UHPLC-Q/Orbitrap HRMS)combined with molecular network was developed in this study for rapidly analyzing the chemical components of the Qinggu San reference sample of classical prescription. Firstly, an ACQUITY UPLC BEH Shield RP_(18) column(2.1 mm×100 mm, 1.7 μm)was used, and acetonitrile and 0.1% formic acid were taken as the mobile phases for gradient elution. The flow rate was 0.4 mL·min~(-1), and the column temperature was 30 ℃. Under these conditions, the mass spectrum data were collected in both positive and negative ion modes of the heated electrospray ionization source. Subsequently, the mass spectrum data of the Qinggu San reference sample were uploaded to the Global Natural Products Social Molecular Network(GNPS)platform for calculation and analysis, and a visual molecular network was built with Cytoscape 3.8.2 software. On this basis, the chemical components of the Qinggu San reference sample were identified by fragmentation regularity of standard compounds, retention time, accurate relative molecular weight of HR-MS, characteristic fragment ions information, literature, and databases. Finally, a total of 105 chemical components were identified and speculated in the Qinggu San reference sample, including 19 iridoid glycosides, 23 flavonoids, 15 phenylpropanoids, 11 triterpene saponins, and 37 other components. Meanwhile, two of these components are potential new compounds. The method used in this study not only achieved rapid and accurate identification of chemical components in the Qinggu San reference sample and provided a scie-ntific basis for the study of pharmacological substances and quality control of Qinggu San compound preparations but also provided a refe-rence for the rapid identification of chemical components in traditional Chinese medicine compound preparations.

Isotopic Differentiation (δ18OPO4) of Inorganic Phosphorus among Organic Wastes for Nutrient Runoff Tracing Studies: A Summary of the Literature with Refinement of Livestock Estimates for Grand Lake St. Marys Watershed (Ohio)

The use of stable isotopes, specifically δ18OPO4 ratios, in differentiating potential sources of inorganic phosphorus (e.g., wastewater, septic, wild animals, domesticated animals, livestock, substrates, or commercial fertilizers) to watersheds is a growing field. This method produces data that, used in conjunction with statistical mixing models, enables a better understanding of contributing sources of runoff. However, given the recent development of this research area there are obvious limitations that have arisen, due in large part to the limited available reference data to compare water samples. Here, we attempt to expand the availability of reference samples by applying stable isotope methods to three types of common agricultural manures: poultry, dairy, and swine. We also aim to concatenate the organic waste literature on this topic, creating a more robust comparison database for future study and application in phosphorus source partitioning research. Among our samples, δ18OPO4 ratios for poultry were considerably elevated compared to dairy and swine manures (values of 18.5‰, 16.5‰, and 17.9‰, respectively). Extending this to other published ratios of δ18OPO4 from various types of waste products (e.g., septic, wastewater, livestock, other animals), a total range from 8.7‰ to 23.1‰ emerged (with existing poultry manure samples also ranking among the highest overall). Variation among samples in the larger dataset demonstrates the need for a further compilation of δ18OPO4 ratios for various types of waste, especially specific to geographic regions and watershed scales. With an increased sample size, the statistical strength associated with these methods would greatly improve.

Fuzzy Relationship between Kansei Images: A Grey Decision-Making Method for Product Form

Current design decision-making methods ignore the fuzzy relationship between Kansei images, and the use of constant weights reduces the accuracy of cognitive evaluation results. To solve these problems, this paper proposes a grey decision-making method for product form driven by the fuzzy relationship between Kansei images. First, according to the initial weight of the Kansei images, variable weight theory is used to determine the Kansei image variable weights of the samples, and the variable weight comprehensive evaluation results for each sample are obtained. Then, based on the correlation and angle of the Kansei images, a cobweb diagram is drawn to represent the fuzzy relationship between the Kansei images of each sample. Combined with the cobweb grey target decision-making model (CGTDM) for multiple Kansei images, decision coefficients are calculated. The decision coefficients are compared and ranked to determine the relatively optimal design reference sample. Finally, the constructed model is compared with the CGTDM for multiple Kansei images and TOPSIS. The results show that the difference coefficient of the proposed method is the largest, and it can reflect the decision-making thinking of the designers and improve the discrimination among the decision-making results to a certain extent.

Analisa Kualitas Briket Arang dari Cangkang Kelapa Sawit Dengan Rasio Perekat Amylum dan Ukuran Partikel Terhadap Parameter Produk Briket

One solution to reduce kerosene consumption is by utilizing waste from palm kernel processing to create biochar briquettes. These biochar briquettes are made from palm kernel shells and serve as a dense alternative energy source. Additionally, biomass charcoal can also be used as an alternative fuel. Biomass charcoal has a high calorific value and produces minimal smoke and emissions when burned. Various biomass materials, including palm kernel shells, wood, and coconut husks, can be used. The study aims to determine the burnable surface area of briquettes within a specific time frame. Particle size and adhesive percentage affect the charcoal density on the briquette surface, which, in turn, influences combustion speed. The results indicate that the burnable surface area of the samples is quite small. Furthermore, the study measures the ignition time required for briquettes to burn completely. On average, the samples burn for 90 to 114 minutes. Although there is no significant difference in burn time between mesh sizes 40, 50, and 60, the reference sample burns for up to 3.5 hours.

Early language learning. A bibliometric analysis of the most influential articles (2010-2022)

The aim of this article is to analyse the evolution of research on language learning at early ages within the main collection of the Web of Science (2010 to 2022) and Scopus (2010 to 2022). To this end, a bibliometric study has been developed taking into consideration the following indicators: diachronic, geographical, authors and source productions. At the same time, an analysis of the structural development of the topics has been carried out on a sample of references from combined searches. The analyses carried out determine an exponential growth pattern in the scientific literature on early language and learning over the last two decades (2010-2022), a period that covers 87.2% of the current scientific production. In relation to the evolution of topics in the field, it is observed that current lines of research are focusing mainly on the results obtained in two areas: (1) Neurosciences and Speech Pathologies and (2) Psychology, Social Sciences and Technology, where the value of A/Y where higher, which indicates that both areas are the ones that have the greatest influence over time.

Investigating nuisance dust complaints: Combining high frequency dust deposition records and source identification using integrated microanalytical techniques

While ducted dust emissions from industry are usually well regulated and controlled, fugitive dust emissions can be difficult to quantify or differentiate from off-site emissions, particularly where fugitive emissions are transient or intermittent. In this study, sources of nuisance dust were investigated using a novel dust deposition sampling methodology, followed by chemical and mineralogical analysis using optical microscopy, x-ray diffraction (XRD), scanning electron microscopy with energy dispersive x-ray spectrometry (SEM-EDS), and isotope ratio mass spectrometry analysis. Dust deposition over 24 h was collected on horizontally orientated 300 mm square glass panels at 6 sites in the region of interest. This method captured very small (<10 mg) masses of dust and could distinguish very small variations in dust deposition at different sites and on different days. Comparison samples collected from potential dust sources at a nearby lime manufacturing facility, and other potential fugitive dust sources in the region were differentiated using XRD mineralogy, visual appearance by optical microscopy and SEM-EDS analysis of individual particles. Comparison of selected dust samples to reference samples indicated most dust deposition at the study sites consisted of soil or sand. However, dust deposition at two sites was sometimes composed of a material that was similar in composition to lime that had been rehydrated to portlandite, but not yet fully carbonated to calcite. Subsequent analysis of δ13C and δ18O for selected dust samples from these two sites were consistent with rapid and recent carbonation of small particles in an alkaline environment, which could have occurred during the atmospheric release and transport of lime, and ruled out fugitive dust emission from lime stockpiles existing on site. Combining the information obtained from high frequency record of dust deposition with targeted mineralogical, isotopic and morphological examinations provided new insight into the source of fugitive dust emissions in this area.

Application of Remote Sensing for Identifying Soil Erosion Processes on a Regional Scale: An Innovative Approach to Enhance the Erosion Potential Model

Soil erosion represents a complex ecological issue that is present on a global level, with negative consequences for environmental quality, the conservation and availability of natural resources, population safety, and material security, both in rural and urban areas. To mitigate the harmful effects of soil erosion, a soil erosion map can be created. Broadly applied in the Balkan Peninsula region (Serbia, Bosnia and Herzegovina, Croatia, Slovenia, Montenegro, North Macedonia, Romania, Bulgaria, and Greece), the Erosion Potential Method (EPM) is an empirical erosion model that is widely applied in the process of creating soil erosion maps. In this study, an innovation in the process of the identification and mapping of erosion processes was made, creating a coefficient of the types and extent of erosion and slumps (φ), representing one of the most sensitive parameters in the EPM. The process of creating the coefficient (φ) consisted of applying remote sensing methods and satellite images from a Landsat mission. The research area for which the satellite images were obtained and thematic maps of erosion processes (coefficient φ) were created is the area of the Federation of Bosnia and Herzegovina and the Brčko District (situated in Bosnia and Herzegovina). The Google Earth Engine (GEE) platform was employed to process and retrieve Landsat 7 Enhanced Thematic Mapper plus (ETM+) and Landsat 8 Operational Land Imager and Thermal Infrared Sensor (OLI/TIRS) satellite imagery over a period of ten years (from 1 January 2010 to 31 December 2020). The mapping and identification of erosion processes were performed based on the Bare Soil Index (BSI) and by applying the equation for fractional bare soil cover. The spatial–temporal distribution of fractional bare soil cover enabled the definition of coefficient (φ) values in the field. An accuracy assessment was conducted based on 190 reference samples from the field using a confusion matrix, overall accuracy (OA), user accuracy (UA), producer accuracy (PA), and the Kappa statistic. Using the confusion matrix, an OA of 85.79% was obtained, while UA ranged from 33% to 100%, and PA ranged from 50% to 100%. Applying the Kappa statistic, an accuracy of 0.82 was obtained, indicating a high level of accuracy. The availability of a time series of multispectral satellite images for each month is a crucial element in monitoring the occurrence of erosion processes of various types (surface, mixed, and deep) in the field. Additionally, it contributes significantly to decision-making, strategies, and plans in the domain of erosion control work, the development of plans for identifying erosion-prone areas, plans for defense against torrential floods, and the creation of soil erosion maps at local, regional, and national levels.

Effect of Thermal Shock Conditions on the Low-Cycle Fatigue Performance of 3D-Printed Materials: Acrylonitrile Butadiene Styrene, Acrylonitrile-Styrene-Acrylate, High-Impact Polystyrene, and Poly(lactic acid).

3D printing technology is becoming a widely adopted alternative to traditional polymer manufacturing methods. The most important advantage of 3D printing over traditional manufacturing methods, such as injection molding or extrusion, is the short time from the creation of a new design to the finished product. Nevertheless, 3D-printed parts generally have lower strength and lower durability compared to the same parts manufactured using traditional methods. Resistance to the environmental conditions in which a 3D-printed part operates is important to its durability. One of the most important factors that reduces durability and degrades the mechanical properties of 3D-printed parts is temperature, especially rapid temperature changes. In the case of inhomogeneous internal geometry and heterogeneous material properties, rapid temperature changes can have a significant impact on the degradation of 3D-printed parts. This degradation is more severe in high-humidity environments. Under these complex service conditions, information on the strength and fatigue behavior of 3D-printed polymers is limited. In this study, we evaluated the effects of high humidity and temperature changes on the durability and strength properties of 3D-printed parts. Samples made of commonly available materials such as ABS (Acrylonitrile Butadiene Styrene), ASA (Acrylonitrile-Styrene-Acrylate), HIPS (High-Impact Polystyrene), and PLA (Poly(lactic acid)) were subjected to temperature cycling, from an ambient temperature to -20 °C, and then were heated to 70 °C. After thermal treatment, the samples were subjected to cyclic loading to determine changes in their fatigue life relative to non-thermally treated reference samples. The results of cyclic testing showed a decrease in durability for samples made of ASA and HIPS. The ABS material proved to be resistant to the environmental effects of shocks, while the PLA material exhibited an increase in durability. Changes in the internal structure and porosity of the specimens under temperature changes were also evaluated using microcomputed tomography (microCT). Temperature changes also affected the porosity of the samples, which varied depending on the material used.

Effect of water-absorbent polymer balls in internal curing on punching shear behavior of bubble slabs

Abstract The punching shear capacity of bubbled slabs is one of the main problems due to its decreased thickness; when there is inadequate curing, the problem becomes more critical, causing the building’s structural performance to deteriorate and exposing it to the risk of collapse. This study aimed to investigate the effect of using water-absorbent polymer balls in internal curing on the punching shear behavior of bubble slabs. Six concrete slabs were cast (1,000 mm × 1,000 mm × 70 mm). The main variables in this study are the type of slab (solid and bubble), type of curing (water and air), and ratio of water-absorbent polymer balls (5 and 10%). Studying the performance use of polymer balls and recycled plastic balls together and in normal strength concretes is limited. Also, investigating their behavior can provide insight into the efficiency of using these materials to improve concrete structures. Results showed that the most effective ratio for using polymer balls in internal curing is 5%, which had a good effect on the ultimate load, the first crack load, deflection, and crack pattern compared to the water-curing sample (reference sample). The water-absorbent polymer balls used in this study can absorb water when added to a concrete mixture. They release the water absorbed and subsequently contract, forming voids that are equivalent in size to the balls. This process facilitates internal curing while reducing the weight of concrete through the air voids left by the balls after they are dry.

MIDIS: JWST/MIRI Reveals the Stellar Structure of ALMA-selected Galaxies in the Hubble Ultra Deep Field at Cosmic Noon

We present deep James Webb Space Telescope (JWST)/Mid-Infrared Instrument (MIRI) F560W observations of a flux-limited, Atacama Large Millimeter/submillimeter Array (ALMA)-selected sample of 28 galaxies at z = 0.5–3.7 in the Hubble Ultra Deep Field (HUDF). The data from the MIRI Deep Imaging Survey (MIDIS) reveal the stellar structure of the HUDF galaxies at rest-frame wavelengths of λ > 1 μm for the first time. We revise the stellar mass estimates using new JWST photometry and find good agreement with pre-JWST analyses; the few discrepancies can be explained by blending issues in the earlier lower-resolution Spitzer data. At z ∼ 2.5, the resolved rest-frame near-infrared (1.6 μm) structure of the galaxies is significantly more smooth and centrally concentrated than seen by the Hubble Space Telescope at rest-frame 450 nm (F160W), with effective radii of R e (F560W) = 1–5 kpc and Sérsic indices mostly close to an exponential (disk-like) profile (n ≈ 1), up to n ≈ 5 (excluding active galactic nuclei). We find an average size ratio of R e (F560W)/R e (F160W) ≈ 0.7 that decreases with stellar mass. The stellar structure of the ALMA-selected galaxies is indistinguishable from a HUDF reference sample of all galaxies with a MIRI flux density greater than 1 μJy. We supplement our analysis with custom-made, position-dependent, empirical point-spread function models for the F560W observations. The results imply that a smoother stellar structure is in place in massive gas-rich, star-forming galaxies at “Cosmic Noon,” despite a more clumpy rest-frame optical appearance, placing additional constraints on galaxy formation simulations. As a next step, matched-resolution, resolved ALMA observations will be crucial to further link the mass- and light-weighted galaxy structures to the dusty interstellar medium.

Investigation of the Engineering Properties of Glass Fiber Reinforced Concrete (GRC) Cured with Internal Resistance

In this study, it was aimed to produce glass fiber reinforced concrete (GRC) samples cured with internal resistance by placing resistance wires at different distances within the concrete molds and applying electric current at various voltages, while the mold surfaces were covered with stretch film. The engineering properties of these samples were then investigated. Previous studies have shown that the mechanical properties of conventional concrete, which were subjected to different curing methods, improved compared to samples that did not undergo any curing process. This study aimed to enhance both the engineering properties of the concrete samples and to accelerate the curing process. Glass fiber reinforced concrete (GRC) with dimensions of 50×50×4 cm was produced, and 25, 35, and 45V resistances were applied to three different molds with wire spacing of 5cm, 6cm, and 7cm. With this application, the GRC samples were subjected to internal resistance curing for the first 24 hours. By applying three different voltages to molds with three different wire spacings, 9 concrete samples were produced, along with 1 reference sample that did not contain any resistance wires and was not subjected to any curing process, making a total of 10 different concrete samples. After curing, the concrete samples were cut into 16cm×4cm×4cm GRC mechanical test specimens. The obtained specimens were tested for 7, 14, and 28 day compressive strength, flexural strength, unit weight, and ultrasonic pulse velocity. To examine the microstructure of the GRC samples, Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA), and Fourier Transform Infrared Spectroscopy (FT-IR) analyses were conducted. These analyses investigated the physical and chemical development processes of the samples, mass losses, products formed after hydration, and structural behaviors. As a result, it was observed that the early-age strength properties of GRC samples cured with internal resistance showed a partial increase compared to the reference sample that was not internally cured, especially in the 7-day samples. In the 14 and 28-day strength comparisons, it was observed that the cured samples showed improvement in flexural strength. According to the data obtained, the samples subjected to 35 volts of electric current yielded better results, especially in the early ages, compared to the reference sample.

Tracing metabolic route of thymoquinone biosynthesis in diverse Nigella sativa L. cultivars using RP-HPLC technique

Although the therapeutic role of Nigella sativa has been known for a long time, for optimal utilization of plant parts, the developmental profiling of bioactive constituents and their dependence on germplasm diversity need to be assessed.Different cultivars of Nigella sativa(covering 3 samples from northern states of India and 3 reference samples) were taken to explore the relative accumulation of thymol (Thy) and thymoquinone (TQ) in different plant parts, i.e., stem, leaf, bud, flower, fruit, and seeds. Amongst all N. sativa cultivars, the maximum TQ content was found in the seed (45.3885 ± 0.3616 mg/g fresh weight) of the RS cultivar. Seeds of the AN1 cultivar showed the maximum Thy content (2.7853± 0.3535 mg/g fresh weight). The minimum Thy content was found in leaves of Haryana (0.0009 ± 0 mg/g fresh weight) and leaves from RS showed the minimum TQ content (0.0029 ± 0.0001 mg/g fresh weight). There are indications that mature seeds are the best source for both Thy and TQ, followed by fresh seeds collected from the intact fruit of N. sativa. In addition, Thy (precursor) and TQ (product)contentin many plant parts are inversely related to each other, especially in the buds. This indicatedthe interdependence of these two bioactive constituents, but not necessarily in all plant parts. It appears that there might be another functional precursor (in addition to Thy)leading to TQ biosynthesis (speculated to be Carvacrol) in Nigella. Such relative dominance of bioactive compounds and their precursors may be used for designing formulations and setting biotransformation experiments for further value addition.

Rheological and structural properties of nanofluids based on hydrolyzed polyacrylamide and aminated carbon nanotubes for enhanced oil recovery

Polymer flooding, a prominent enhanced oil recovery (EOR) technique, involves injecting polymers such as partially hydrolyzed polyacrylamide (HPAM) to increase water viscosity for more effective oil displacement. Overall, HPAM exhibits good shear stability, thermal tolerance, and cost-effectiveness; however, it has limitations such as temperature constraints and salinity susceptibility. Integrating nanomaterials into HPAM-based EOR is a promising and innovative strategy, with aminated carbon nanotubes standing out as a strong candidate due to their remarkable tensile strength, excellent thermal conductivity, exceptional chemical and physical stability, and good dispersibility and versatility. This study employed ethylenediamine-functionalized oxidized multiwalled carbon nanotubes (MWCNTO-EDA) as an additive in HPAM solutions for EOR applications. Extensive analyses, including FTIR, Raman, TGA, zeta potential, elemental analysis, and cryo-TEM, confirmed the chemical composition and morphology of HPAM and the nanomaterials. Cryo-TEM images under various ionic conditions revealed that the presence of salts caused polymer chain contraction into spherical structures, explaining the reduced viscosity in high-salinity nanofluids. Rheological tests at 70 °C demonstrated that MWCNTO-EDA significantly increased the nanofluid viscosity over reference HPAM fluids. Notably, nanofluids containing 0.5 % MWCNTO-EDA exhibited an average 55 % viscosity increase at an ionic strength of 0.6, which is vital for applications in EOR where heightened viscosity is crucial. Aging tests, performed over 180 days at 70 °C, displayed substantial viscosity improvements in nanofluids containing 1.0 % MWCNTO-EDA, achieving up to a 150 % increase over reference samples. MWCNTO-EDA emerges as a valuable additive for creating innovative nanofluids, addressing critical limitations and preserving HPAM conformation, making it suitable for EOR in challenging environmental conditions.

Water rotational relaxation time measurement by shortwave infrared micro spectroscopy(SWIR) at sub-zero temperatures

The shortwave infrared spectroscopy (SWIR) is the noble method which allows to evaluate the rotational relaxation time of water (RRTW) in a sample. Because SWIR requires the reference sample of pure water, the measurement temperature is limited only at above 0 °C. In this study, we expanded this temperature limitation of SWIR by using alternative reference solutions with freezing points below 0 °C, including sugar and glycerol solutions. The results showed that some reference sample solutions are useable for evaluating RRTW in samples below 0 °C. It was found that RRTW in solution measured by newly proposed SWIR agrees with RRTW measured by dielectric spectroscopy in 10% accuracy when it is shorter than 100psec.

Window size dependence of gain and bandwidth in avalanche photodiodes with multiple multiplication layers under near Geiger-mode operation.

We consider avalanche photodiodes (APDs) functioning under near Geiger-mode operation for extremely weak light (single or several photons) detection, such as in LiDAR receivers. To meet such demands, APDs which simultaneously have a large active window size, moderate bandwidth (∼GHz), and high internal gain (responsivity), are highly desired. However, it is difficult to design APDs capable of meeting the afore-mentioned performance requirements due to the intrinsic limitations of the gain-bandwidth product (GBP). In this work, we demonstrate that the GBP bottleneck in the APDs can be overcome by using multiple (3) In0.52Al0.48As based multiplication (M-) layers with a thick In0.53Ga0.47As absorber (2 µm). Moreover, the characteristic invariant 3-dB bandwidth in our APDs, from low to an extremely high operation gain, becomes more pronounced with an increase of its active window diameter (40 to 200 µm). This characteristic makes it very attractive for collecting weak light in free space as is required for LIDAR receiver applications. Comparison shows that the 200 µm APD exhibits a higher 0.9 Vbr responsivity (15 vs. 7 A/W), larger maximum gain (460 vs. 110), and higher GBP (468 vs. 131 GHz) than does the 40 µm reference sample and can sustain a constant 3-dB bandwidth (1.4 GHz) over a wide range of operation gains (10 to 460). The dependence of the APD performance on the window size can be attributed to the influence of the surface states on the edge of the etched mesa. Here, we further demonstrate a backside-illuminated structure with a flip-chip bonding package which minimizes this phenomenon in small APDs ensuring high-speed performance. Compared with the top-illuminated reference samples, the flip-chip bonding packaged device shows a further enhancement of the responsivity (10.7 vs. 7 A/W), 3-dB bandwidth (4.1 vs. 3.9 GHz), and saturation current (4.25 vs. 3.6 mA). The excellent static and dynamic performance of our flip-chip APD in turn leads to an unprecedented high velocity sensitivity (5 µm/sec) and superior quality 4-D FMCW LiDAR images compared to that obtainable with p-i-n-based or top-illuminated reference devices with the same small active window size (40 µm).

Rationally construction of Dy2O3/g-C3N4 heterojunctions with largely enhanced photocatalytic hydrogen evolution activity

In this paper, Dy2O3/g-C3N4 photocatalysts with augmented photocatalytic hydrogen evolution activity were obtained by a pore impregnation method after baking. The samples were evaluated via scanning electron microscopy (SEM) and X-ray diffraction (XRD). Separation and migration efficiency of photogenerated carriers was analyzed using surface photovoltage spectroscopy (SPS), transient photocurrent density (TPR) and electrochemical impedance spectroscopy (EIS). Through low-temperature electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS), nitrogen vacancies were successfully introduced into g-C3N4. All Dy2O3/g-C3N4 samples display more stronger photocatalytic activity than the reference g-C3N4. Notably, 3 % DyO/CN exhibits the highest photocatalytic activity. The average photocatalytic hydrogen evolution rate over 3 % DyO/CN reaches 9.9 mmol·g−1·h−1, which is nearly 3 times of that over the reference sample (3.3 mmol·g−1·h−1). In view of the observations, photocatalytic mechanism of Dy2O3/g-C3N4 heterojunction was rationally proposed.

Evolution of early hydration in mortar by using waste dolomite powder as a micro-aggregate

The evolution of early hydration in cement – based material is always one of important issues for investigating their engineering application. This study investigated the early hydration reaction of mortars containing different waste dolomite powder (WDP) contents. Compared to the reference sample (WDP0), the hydration process, hydration products, pore structure and mechanical properties of samples prepared by WDP were studied at the early stage. For the hydration process, the 1H low – field nuclear magnetic resonance (NMR) and chemical shrinkage testing results indicated that the process of early hydration of cement could be significantly accelerated by incorporating WDP. Meanwhile, the quantities of hydration products (Portlandite and calcite) in samples with WDP have a significant variation by X-ray diffraction results and thermogravimetric analysis. In addition, the WDP40 has denser pore structure and higher mechanical properties than WDP0. After curing 3 d, the pore volume of WDP40 has a reduction of 17.84 %, the flexural and compressive strength of WDP40 were increased by 6.6 % and 18.06 %, respectively. Based on the mechanism analysis, the filling effect and nucleation effect of WDP in mortars contributed to the improvement of early cement hydration. This study is meaningful to evaluate the impact of WDP on the evolution of early cement hydration, which is expected to offer a reliable reference for the application of inert materials in cement – based materials.

Single-beam low-frequency loss modulation technique for two-photon absorption measurement

We present a straightforward and reliable single-beam configuration designed for the assessment of two-photon absorption (2PA) through the utilization of the loss modulation technique. Mechanical rotation of a half-wave plate induces a sinusoidal modulation in the envelope of the probe pulse train. The elimination of spurious signals is achieved by determining the difference of the lock-in amplifier output at the focused and defocused positions of the sample. Our findings, based on measurements with dye solutions and crystalline silicon, demonstrate the feasibility of determining the 2PA coefficient, subject to preliminary calibration of the setup with reference samples. Remarkably, the acquisition of the 2PA signal in silicon at 1030 nm is accomplished with less than 200 pJ energy of the laser pulse, overcoming the challenge posed by concurrent linear absorption. Additionally, a signal of 3PA is revealed despite the presence of 2PA and linear absorption.

Analytical Determination of Aflatoxin in Ground Corn Check Samples Completed by Multiple Laboratories over Several Years.

Mycotoxins are toxic molecules produced by multiple fungal species, including Aspergillus and Fusarium. Fungal infection of crops can result in mycotoxins entering the animal and human food supply. Enzyme-linked immunosorbent assays and other immunological assays have been developed to detect mycotoxins in foods. To calibrate the response of those methods, reference materials with known amounts of homogeneously dispersed mycotoxins are often utilized, where the mycotoxin concentrations have been determined using high-performance liquid chromatography coupled with absorbance or fluorescence detection methods, or high-performance liquid chromatography coupled with mass spectrometry detection methods. Therefore, it is important that the analytical methods provide accurate and precise quantitation of mycotoxins. The reference materials must also contain homogeneously dispersed known quantities of mycotoxin. To evaluate the accuracy and precision of mycotoxin reference materials and the analytical methods, quantitative results from multiple laboratories were completed each year for several years on ground corn check samples containing known levels of mycotoxins. Results for the quantitation of aflatoxin-containing corn reference samples are presented in this article.

BIOM-12. LIQUID BIOPSIES IN CNS TUMORS: A COMBINED APPROACH TO PROFILING CSF

Abstract In precision medicine, molecular profiling of pediatric tumors is crucial for diagnosis, prognosis, and therapeutic decision-making. Traditional biopsy methods, often invasive, have inherent risks and may not capture a tumor’s heterogeneity. Liquid biopsy, however, offers a minimally invasive and comprehensive alternative. We demonstrate its utility in diagnosing and monitoring brain tumors using cell-free DNA (cfDNA) from cerebrospinal fluid (CSF), where conventional cfDNA plasma analysis has shown low sensitivity. Through digital droplet PCR, we analyzed 23 plasma samples from patients with BRAFV600E or H3K27M gliomas, detecting H3K27M in a single case. Conversely, CSF samples revealed 8 positives out of 9 for these mutations, underscoring CSF’s diagnostic value. We advanced our methodology by developing a 21-gene hybrid-capture panel paired with low-pass whole-genome sequencing to pinpoint copy number variations. In our reference sample set, the panel achieved a detection limit with variant allele frequencies as low as 0.5%. With 10ng of cfDNA, we reached 83% sensitivity and 100% specificity, which increased to 100% sensitivity with a 30ng input. Using this assay, we profiled 141 CSF samples from 119 patients, achieving 70% positivity rate in active disease cases in a validation cohort—ranging from 50% in low-grade gliomas to 84% in high-grade gliomas and 75% in medulloblastomas. Intriguingly, of 14 queried tumor samples lacking biopsy confirmation, half showed positive ctDNA results using the panel and/or low-pass whole-genome sequencing. This approach allowed for differential diagnoses in suspected medulloblastoma relapses, tailored therapeutic interventions based on CSF profiles, and effective treatment response monitoring. In summary, our integrated liquid biopsy strategy showcases a powerful, clinically applicable tool that significantly enhances patient care in pediatric neuro-oncology.