Empty Cell Research Articles

An improved YOLOv8 method for identifying empty cell and unqualified plug seedling

An improved YOLOv8 method for identifying empty cell and unqualified plug seedling

Transcriptome Profiling Associated with CARD11 Overexpression in Colorectal Cancer Implicates a Potential Role for Tumor Immune Microenvironment and Cancer Pathways Modulation via NF-κB.

The immune system plays a critical role in inflammation by initiating responses to infections or tissue damage. The nuclear factor-κB (NF-κB) pathway plays a key role in inflammation and innate immunity, as well as other cellular activities. Dysregulation of this well-choreographed pathway has been implicated in various diseases, including cancer. CARD11 is a key molecule in the BCL10-MALT1 complex, which is involved in transducing the signal downstream of the NF-κB pathway. This study aims to elucidate how CARD11 overexpression exacerbates the prognosis of colorectal cancer (CRC). To identify the cellular pathways influenced by CARD11, transcriptomic analysis in both CRC cell lines and patients was carried out on CARD11- overexpressed HCT-116 and HT-29 CRC cell lines alongside empty vector-transfected cell lines. Furthermore, a comparison of transcriptomic data from adenoma and carcinoma CRC patients with low- (CARD11-) and high-(CARD11+) CARD11 expression was carried out. Whole transcriptomics and bioinformatics analysis results indicate that CARD11 appears to play a key role in CRC progression. Absolute GSEA (absGSEA) on HCT-116 transcriptomics data revealed that CARD11 overexpression promotes cell growth and tissue remodeling and enhances immune response. Key genes co-expressed with CARD11, such as EP300, KDM5A, HIF1A, NFKBIZ, and DUSP1, were identified as mediators of these processes. In the HT-29 cell line, CARD11 overexpression activated pathways involved in chemotaxis and extracellular matrix (ECM) organization, marked by IL1RN, MDK, SPP1, and chemokines like CXCL1, CXCL3, and CCL22, which were shown to contribute to the more invasive stage of CRC. In patient samples, adenoma patients exhibited increased expression of genes associated with the tumor immune microenvironment, such as IL6ST, collagen family members, and CRC transition markers, such as GLI3 and PIEZO2, in CARD11+ adenoma patients. Carcinoma patients showed a dramatic increase in the expression of MAPK8IP2 in CARD11+ carcinoma patients alongside other cancer-related genes, including EMB, EPHB6, and CPEB4.

MUM, a maternal unknown message, inhibits early establishment of the medio-lateral axis in the embryo of the kelp Saccharina latissima.

Brown algae are multicellular photosynthetic organisms that have evolved independently of plants and other algae. Here, we have studied the determinism of body axis formation in the kelp Saccharina latissima. After microdissection of the embryo, we show that the stalk, an empty cell that retains the embryo on the maternal tissue, represses longitudinal cell divisions in the early embryo, thereby reinforcing the establishment of the initial apico-basal axis. In addition, it promotes cell growth and controls cell shape and arrangement in the flat oblong embryo composed of cells aligned in rows and columns. Although the stalk persists for several weeks until the embryo reaches at least 500 cells, proper embryogenesis requires connection to maternal tissue only during the first 4 days after fertilisation, i.e. before the embryo reaches the 8-cell stage. Transplantation experiments indicate that the maternal signal is not diffused in seawater, but requires contact between the embryo and the maternal tissue. This first global quantitative study of brown algal embryogenesis highlights the role of MUM, an unknown maternal message, in the control of growth axes and tissue patterning in kelp embryos.

The vampyrellid amoeba Strigomyxa ruptor gen. et sp. nov. and its remarkable strategy to acquire algal cell contents.

The vampire amoebae (Vampyrellida, Rhizaria) inhabit freshwater, marine, and terrestrial ecosystems and consume a wide range of eukaryotic prey. This includes diverse microalgae, fungi, and microscopic animals. One of the most captivating aspects of the vampyrellids is their ability to extract the cell contents of other eukaryotes after local dissolution of the prey cell wall, a feeding strategy that occurs in several vampyrellid families, but is best studied in Vampyrella species that attack zygnematophyte green algae. Here, we report two new vampyrellid strains from temperate moorlands in Germany with a yet-undescribed feeding strategy: internal protoplast extraction and cell wall regurgitation. This feeding strategy involves the phagocytosis of whole desmid cells (genus Closterium, Zygnematophyceae), internal cleavage of the algal cell wall, extraction of the cell contents, and subsequent exocytosis of bundled empty cell walls. The large primary food vacuole formed during the process has exceptional functions, as it forms internal feeding pseudopodia, packages algal cell contents into smaller secondary vacuoles, and transforms into a "waste vacuole" with cell wall remnants. The new feeding strategy, which - in the widest sense - is reminiscent of the pellet casting of owls, reveals a stunningly sophisticated behavior of single protist cells. Based on morphological, phylogenetic, and autecological data, both vampyrellid strains are nearly identical and here assigned to a new and quite unique vampyrellid taxon, Strigomyxa ruptor gen. et sp. nov. (Leptophryidae, Vampyrellida).

O-211 Exploring risk factors of mismatch in the ART laboratory: An analysis based on 73719 electronic witnessing points

Abstract Study question What are the risk factors associated with mismatch (MM) and genuine mismatch (GMM) in the ART laboratory? Summary answer MM is associated with individual operators, oocyte denudation (OD) and embryo transfer (ET) processes, while GMM related to OD and extended work hours (>4pm). What is known already Mix-up of gametes or embryos in the ART laboratory causes dramatic consequences to both the patients and clinics. Recent studies using electronic witnessing system (EWS) equipped with radio frequency ID (RFID) tags, have revealed that most MM events only involved empty cell culture vessels, while the true mix-up risk arose from a subgroup of GMM involving culture vessels carrying gametes or embryos belonging to different patients. Exploration of risk factors associated with MM and GMM occurrence, separately, is still currently lacking in the literature. Study design, size, duration A total of 73719 witnessing points were retrospectively extracted from an EWS database, representing 11210 consecutive treatment cycles performed at Fertility North between January 2016 and July 2023. The 11210 treatment cycles comprised 5472 fresh IVF, 3732 frozen embryo transfer, 93 oocyte freeze, and 1913 intrauterine insemination cycles. Participants/materials, setting, methods All laboratory work areas were equipped with RFID readers. A MM was triggered by detection of RFID tagged cell culture vessels (either carrying biological material or not) and/or ID cards that belong to different patients in the same work area. A GMM was defined when a MM had involved biological materials and/or patients during procedure, with a potential mix-up. Risk factors evaluated included time of the day, weekdays, weekend, public holiday, operators, and laboratory processes. Main results and the role of chance A total of 138 (0.19%) MMs and 16 (0.02%) GMMs were identified during the study period, without actual mix-up. MM rate was the highest during 12-2pm (0.28%, p < 0.001) compared to other periods of the day, whilst GMM was the highest after 4pm (0.13%, p = 0.004). Neither MM nor GMM was associated with any specific weekday, weekend or public holiday (p > 0.05, respectively). Amongst 8 laboratory processes investigated, ET (0.36%, p < 0.001) led to the highest MM rate, followed by OD (0.35%, p = 0.021), but no increase was observed in oocyte collection, sperm preparation, insemination, embryo culture, cryopreservation and Assign ID. OD was the only process associated with higher GMM (0.13%, p < 0.001). Furthermore, Two of the 20 assessed operators were identified to produce more MMs (0.59%, p < 0.001, and 0.40%, p = 0.004; respectively) while GMM rates were similar among all operators (p > 0.05). Multivariate logistic regression indicated that the OD (adjusted odds ratio or aOR=2.147, p = 0.011) and ET (aOR=2.118, p < 0.001) processes as well as 2 individual operators (aOR=3.511, p < 0.001; aOR=2.538, p = 0.002; respectively) were independent risk factors to MM, but not the 12-2pm period of the day (aOR=1.341, p > 0.05). Finally, both extended work hours beyond 4pm (aOR=8.651, p = 0.005) and OD (aOR=9.538, p < 0.001) were independent risk factors to GMM. Limitations, reasons for caution Each individual ART laboratory has a unique team of scientists and workflow arrangement so findings in our study may not be universally applicable. GMM occurs at an extremely low frequency and is often calculated based on large numbers, therefore caution ought to be taken at statistical interpretation of data. Wider implications of the findings GMMs should be separated from MMs for analysis considering the very different clinical implications. Sufficient staffing with regular break and streamlined workflow are highlighted in preventing mix-up in the ART laboratory. Using electronically logged data, EWS enables identification of site-specific risk factors, which facilitates the development of corresponding preventative protocols. Trial registration number not applicable

In-situ homeotropic alignment of dye doped liquid crystal molecules on multilayered self assembled nanoparticles in confined cells for next generation display devices

The in-situ homeotropic alignment (HA) of pure liquid crystal (LC) and dye doped LC molecules was prepared on the multilayered self assembled silica nanoparticles (SNPs) deposited on the substrates in a confined empty ITO cell. The LC and azo dye mixtures with (0.0625–0.5 wt%) concentrations show the uniform in-situ HA of nematic LC (NLC) over SNPs coated surface. The surface morphology with mapping of elements and functionality of the SNPs coated ITO glass substrate were confirmed by “field emission scanning electron microscope (FESEM)” and “X-ray photoelectron spectroscopy (XPS)”. Polarized optical microscopic textures and conoscopic view of pure and dye doped LC mixtures in SNPs coated confined cells, confirmed the HA of LC molecules and exhibited the uniform black textures under crossed polarizers. The electro-optic behaviour of dye doped homeotropically aligned LC (HALC) cells was compared to pure SNPs coated HALC cell. The results showed that on increasing the azo dye concentration (0.0625–0.25 wt%), the threshold (Vth) and operating (Vo) voltages were found decreased. However, on further increase of dye concentration to 0.5 wt%, Vth and Vo were observed relatively increased. The contrast ratio (CR) was found improved in dye doped HALCs with maximum CR at lowest dye concentration (0.0625 wt%). The UV results exhibit higher absorbance of the dye doped HALC cells with increasing the dye concentration. Also, the band gap values showed that the addition of even small amount of dye, it reduced the value of band gap in HALC cell.

An optimal exact interval for the risk ratio in the 2×2$$ 2\times 2 $$ table with structural zero

AbstractThe table with a structural zero represents a common scenario in clinical trials and epidemiology, characterized by a specific empty cell. In such cases, the risk ratio serves as a vital parameter for statistical inference. However, existing confidence intervals, such as those constructed through the score test and Bayesian methods, fail to achieve the prescribed nominal level. Our focus is on numerically constructing exact confidence intervals for the risk ratio. We achieve this by optimally combining the modified inferential model method and the ‐function method. The resulting interval is then compared with intervals generated by four existing methods: the score method, the exact score method, the Bayesian tailed‐based method and the inferential model method. This comparison is conducted based on the infimum coverage probability, average interval length and non‐coverage probability criteria. Remarkably, our proposed interval outperforms other exact intervals, being notably shorter. To illustrate the effectiveness of our approach, we discuss two examples in detail.

Nanometric determination of the thickness of aqueous samples for accurate molar absorption coefficients of water-soluble molecules in the mid-infrared region

Absorption spectra of aqueous samples measured by transmission need to be acquired using very thin cells (5–50 μm) when targeting the mid-infrared (mid-IR) region due to the strong background absorbance of liquid water. The thickness of the cell used controls the pathlength of the light through the sample, a value needed to transform absorption spectra into molar absorption coefficient spectra, or to determine solute concentrations from absorption spectra. The most accurate way to determine the thickness of an empty cell (i.e., filled with air) is from the period of an interference pattern, known as interference fringes, that arises when the cell is placed perpendicular to the path of light in the spectrometer. However, this same approach is not directly applicable to determine the thickness of a cell filled with an aqueous solution, due partially to the smaller amplitude of the interference fringes but fundamentally caused by its complex waveform, with a wavenumber-dependent oscillation period. Here, using Fresnel equations, we derived analytical expressions to model interference fringes in absorption spectra obtained by transmission, which are also valid for aqueous samples. We also present a novel Fourier-based analysis of the interference fringes that, in combination with the derived analytical expressions, allowed us to determine the pathlength of aqueous samples with an error below ∼ 50 nm. We implemented this novel approach to analyze interference fringes as a Live Script running in the software Matlab. As an application, we measured the absorption spectra of a 97 mM solution of MES buffer at pH 3.4 and pH 8.4 using cells of various nominal thicknesses (6, 25 and 50 μm), whose actual thicknesses were determined using the present approach. The derived molar absorption coefficient spectrum for both the acidic and basic forms of MES were virtually identical regardless of the cell, indicating that the determined thicknesses were likely very accurate. These results illustrate the utility of the present methodology in obtaining accurate molar absorption coefficient spectra of water-soluble molecules in the mid-IR region.

A new, automated method for the investigation of melting point depression under carbon dioxide pressure

The aim of this work was to develop a new, automated method for the detection of solid-liquid phase transitions in the presence of high-pressure carbon dioxide. This is allowed because of the dissolution of the medium in the sample during the solid-liquid-gas equilibrium measurement. The pressure of an empty reference cell and one containing a solid sample is compared by a differential pressure transmitter. A gradual heating program is conducted after their equal pressurization. The solid-liquid transition of the sample is marked by a sharp decrease in the pressure of the sample holder (compared to the reference cell). A processing algorithm for the recorded time – temperature – pressure-difference data was implemented, to determine the melting temperature range accurately and automatically. The apparatus was validated with racemic ibuprofen and benzoic acid, and provides a new, objective, and easy-to-automate alternative to determine the melting temperature in high-pressure carbon dioxide.

FACILE PRODUCTION OF 4-HYDROXYBENZOIC ACID FROM OIL PALM EMPTY FRUIT BUNCH CELL WALLS BY ALKALI DEGRADATION AT ROOM TEMPERATURE

Oil palm empty fruit bunches are biorefinery waste produced from the oil palm factory. Palm lignin is partially ended with p-hydroxybenzoylated structure, which is a promising resource to produce 4-hydroxybenzoic acid. Herein, 4-hydroxybenzoic acid is produced by the degradation of oil palm empty fruit bunch cell walls with sodium hydroxide solution at room temperature without lignin isolation. The 4-hydroxybenzoic acid was obtained as the only main monomeric product from the process. The yield of 4-hydroxybenzoic acid can reach 7.87% based on the amount of oil palm empty fruit lignin. The sodium hydroxide concentration is the most important factor that affects the 4-hydroxybenzoic acid production yield and selectivity. The possible 4-hydroxybenzoic acid production routes were proposed. And the production route is considered to be formed mainly by the cleavage of C-O bonds at the γ-hydroxyl position of the syringyl unit in oil palm empty fruit bunch lignin.

Lacunarity and Neology: Diachronic Aspect (Based on the Material of Russian Writers’ Epistolary Texts of the 19th Century)

Purpose. The author considers the problem of establishing a correlation between lacunarity and neologization of the language system in the diachronic aspect using methods of semantic, contrastive, contextual, corpus and quantitative analysis. The material for the study is Russian writers’ epistolary texts of the second half of the 19th century. The author specifies the meaning of the term lacuna in relation to diachrony: a lacuna is an empty cell in the lexical system of a language, revealed retrospectively by detecting means that compensate for it. Results. The author’s classification of lacunae is based on a semiotic criterion: conceptual lacunae are empty cells in the lexical system, which are characterized by the absence of both the signifier and the signified (concept); lexical lacunae are empty cells in the lexical system, which lack a signifier, but have a non-verbalized signified that exists in public or individual consciousness. Conclusion. Extralinguistic and intra-linguistic factors determined the formation and compensation of communicatively significant lacunae in the lexical system at the level of language and speech: changes in the socio-political, economic, cultural life of Russia; interlanguage contacts; the need for nomination or re-designation of the concept; the laws of linguistic regularity, analogy, generalization and differentiation, economy, the tendency to expressiveness.

A Recommendation System Involving a Hybrid Approach of Student Review and Rating for an Educational Video

Video recommendation systems in e-learning platforms are a specific type of recommendation system that uses algorithms to suggest educational videos to students based on their interests and preferences. Student’s written feedback or reviews can provide more details about the educational video, including its strengths and weaknesses. In this paper, we build an education video recommender system based on learners’ reviews. we use LDA topic model on textual data extracted from educational videos to train language models as an input to supervised CNN model. Additionally, we used latent factor model to extract the educational videos' features and learner preferences from learners’ historical data (ratings and reviews) as an output CNN model. In our proposed technique, we use hybrid user ratings and reviews to tackle sparsity and cold start problem in the recommender system. Our recommender uses user review to suggest new recommended videos, but in case there is no review (empty cell in matrix factorization) or unclear comment then we will take user rating on that educational video. We worked on real-world big and diverse learning courses and video content datasets from Coursera. Results show that new prediction ratings from learners' reviews can be used to make good new recommendations about videos that have not been previously seen and reduce cold start and sparsity problem effects.

The influence of air gaps on buffer temperature within an engineered barrier system

High-level radioactive waste produced by nuclear power plants are disposed subterraneously utilizing an engineered barrier system (EBS). A gap inevitably exists between the disposal canisters and buffer materials, which may have a negative effect on the thermal transfer and water-blocking efficiency of the system. As few previous experimental works have quantified this effect, this study aimed to create an experimental model for investigating differences in the temperature changes of bentonite buffer in the presence and absence of air gaps between it and a surrounding stainless steel cell. Three test scenarios comprised an empty cell and cells partially or completely filled with bentonite. The temperature was measured inside the buffers and on the inner surface of their surrounding cells, which were artificially heated. The time required for the entire system to reach 100 °C was approximately 40% faster with no gap between the inner cell surface and the bentonite. This suggests that rock–buffer spaces should be filled in practice to ensure the rapid dissipation of heat from the buffer materials to their surroundings. However, it can be advantageous to retain buffer–canister gaps to lower the peak buffer temperature.

Expression of the Hepatitis C Virus core-NS3 Fusion Protein on the Surface of Bacterial Ghosts: Prospects for Vaccine Production.

Antigen presentation using bacterial surface display systems, on one hand, has the benefits of bacterial carriers, including low-cost production and ease of manipulation. On the other hand, the bacteria can help in stimulating the immune system as an adjuvant. For example, using bacterial surface display technology, we developed a hepatitis C virus (HCV) multiple antigens displaying bacteria's surface and then turned it into a bacterial ghost. The HCV core and NS3 proteins' conserved epitopes were cloned into the AIDA gene plasmid as an auto transporter. The recombinant plasmid was then transformed into Escherichia coli (E. coli) Bl21 (DE3). Recombinant bacteria were then turned into a bacterial ghost, an empty cell envelope. Whole-cell ELISA, flow cytometry, and Western blot techniques were used for monitoring the expression of proteins on the surface of bacteria. A fusion protein of HCV core-NS3-AIDA was successfully expressed on the E. coli Bl21 (DE3) surface and confirmed by western blotting, Enzyme-Linked Immunosorbent Assay (ELISA), and flow cytometry detection techniques. The presence of HCV antigens on non-pathogen bacteria surfaces holds promise for developing safe and cost-benefit-accessible vaccines with optimal intrinsic adjuvant effects and exposure of heterologous antigens to the immune system.

87 Assessing Translocation of Diesel Particles Across Permeable Insert Membranes with Different pore Sizes

Abstract During inhalation, airborne particles, especially particulate matters (PM) ≤ 2.5 µm, can deposit and accumulate on the alveolar epithelial cells, and induce the release of inflammatory mediators in the lungs. Some in vivo studies have shown that PM2.5 as well as these inflammatory mediators can cross the air-blood tissue barrier into the blood circulation, inducing adverse effects on organs beyond the lungs. However, methods to quantify the translocation of particles across the lung barriers are still not well established. In this study, SRM2975 diesel exhaust particles (DEPs) dispersions at 80, 20, 2 and 0.1 µg/mL were prepared and added to empty permeable cell culture inserts with different pore sizes (0.4, 1 and 3 µm) membranes for 24 hours. Subsequently, the apical and basal fraction were collected for analysis by electron micrograph (TEM) and ultraviolet-visible spectroscopy (UV-VIS). Our results showed that translocation of DEPs at 80, 20 and 2 µg/mL from apical to basal fraction can occur through membranes with 1 and 3 µm, but not 0.4 µm pore sizes. Approximatively, 60-65% of DEPs can translocate through the membrane with 3.0 µm pore size and 33-55% can translocate through with 1.0 µm pore size. Moreover, higher translocation was observed with DEPs at 20 µg/mL compared to 80 µg/mL. In conclusion, the translocation of DEPs depends not only on the apical concentration but also on the pore sizes of the membranes. We currently quantify the translocation across inserts with A549 lung cell tissues and the analysis is ongoing.

Calibration-free method to study temperature dependence of microwave dielectric properties of nematic liquid crystals

ABSTRACTThe present article shows an original transmission-reflection-based method to characterise the microwave dielectric properties of liquid crystals. This new method offering broadband capabilities of transmission-reflection method without the need for vector network analyser calibration. It is based on two measurements in the frequency range: one measurement is performed with the empty cell, the other with the cell filled with the material. The analysis of the two recorded scattering matrices allows to eliminate all error terms and to extract real and imaginary parts of the complex dielectric constant. In this paper, we first present this method, its validation in comparison to other characterisation methods. Secondly, we present an appropriate measuring cell which allows measurements in the frequency range 26 GHz-40 GHz which is also well-suited for temperature-dependent measurements. This method is used to perform dielectric microwave measurements on 5CB liquid crystal. Finally, we discuss the temperature-dependent microwave dielectric properties (permittivity, losses and dielectric anisotropy).

Machine vision-based tomato plug tray missed seeding detection and empty cell replanting

The current tomato plug tray sowing methods are plagued by the issue of missed sowing. Consequently, the detection of missed sowing and empty cells replenishment of tomato plug trays after initial sowing is an important prerequisite to realizing precision sowing of plug trays and improving the quality of plug tray seedlings. This study proposed a machine vision-based information perception method for tomato plug trays to detect missed seeds and replenish empty cells. First, based on a YOLOv5x network model, deep learning training was employed to obtain a detection model for identifying tomato seeds in complex backgrounds of plug trays. Thereafter, the location of the tomato seeds was compared with the coordinate value of the edge of the hole, and the missed holes were detected. Based on the missed cells detection results, the empty cell coordinates were converted into replanting coordinates, and the plug tray conveyor and the replanting suction needle are controlled separately considering the replanting row information to replant the missed cavities row by row. Further, the tomato plug tray missed seeding detection and replenishment device was built and tested at a seedling greenhouse. The results indicated an average detection accuracy of 92.84 % with average detection time per tray of 13.475 s. The success rate of replanting on trays was determined to be 91.7 % with 5 %-20 % misses. In addition, the productivity of the tray was approximately 42.4 trays/h. Thus, the proposed method of detecting and replanting misses in tomato trays can be used to improve the performance of tomato seeding. Moreover, it can be used as a reference to improve the precision and efficiency of tomato seeding in plug trays.

Production of Lactobacillus plantarum ghosts by conditional expression of a prophage-encoded holin.

Bacterial ghosts (BGs) are non-viable empty bacterial cell envelopes with intact cellular morphology and native surface structure. BGs made from pathogenic bacteria are used for biomedical and pharmaceutical applications. However, incomplete pathogenic cell inactivation during BG preparation raises safety concerns that could limit the intended use. Therefore, safer bacterial cell types are needed for BG production. Here, we produced BGs from the food-grade Gram-positive bacterium Lactobacillus plantarum TBRC 2-4 by conditional expression of a prophage-encoded holin (LpHo). LpHo expression was regulated using the pheromone-inducible pSIP system and LpHo was localized to the cell membrane. Upon LpHo induction, a significant growth retardation and a drastic decrease in cell viability were observed. LpHo-induced cells also showed membrane pores by scanning electron microscopy, membrane depolarization by flow cytometry, and release of nucleic acid contents in the cell culture supernatant, consistent with the role of LpHo as a pore-forming protein and L. plantarum ghost formation. The holin-induced L. plantarum BG platform could be developed as a safer alternative vehicle for the delivery of biomolecules.

IRun: Horizontal and Vertical Shape of a Region-Based Graph Compression.

Graph data are pervasive worldwide, e.g., social networks, citation networks, and web graphs. A real-world graph can be huge and requires heavy computational and storage resources for processing. Various graph compression techniques have been presented to accelerate the processing time and utilize memory efficiently. SOTA approaches decompose a graph into fixed-size submatrices and compress it by applying the existing graph compression algorithm. This approach is promising if the input graph is dense. Otherwise, an optimal graph compression ratio cannot be achieved. Graphs such as those used by social networks exhibit a power-law distribution. Thus, applying compression to the fixed-size block of a matrix could lead to the empty cell processing of that matrix. In this paper, we solve the problem of ordered matrix compression on a deep level, dividing the block into sub-blocks to achieve the best compression ratio. We observe that the ordered matrix compression ratio could be improved by adopting variable-shape regions, considering both horizontal- and vertical-shaped regions. In our empirical evaluation, the proposed approach achieved a 93.8% compression ratio on average, compared with existing SOTA graph compression techniques.

Use of polarized ATR measurements to simplify referencing in continuous sample monitoring by absorption spectroscopy

Using the difference in the effective path lengths of perpendicular- and parallel-polarized light in attenuated total reflectance (ATR) spectroscopy, we demonstrated acquisition of infrared (IR) absorption spectra without needing periodic measurements of a standard reference such as an empty optical cell. With a liquid sample constantly in contact with the ATR internal reflection element (IRE), we used the perpendicular-polarized signal, which has lower effective path length, as the reference signal, and the parallel-polarized signal, as the sample signal. To demonstrate the validity of this method and the need for periodic measurements of a standard reference in the conventional method, we measured unpolarized and polarized ATR spectra of air and isooctane using a Fourier transform infrared (FTIR) spectrometer on two consecutive days. For the conventional method, we used the unpolarized signals of air and isooctane to calculate the absorbance and showed that there were some artifacts with baseline curvature when the air signal from day 1 was used with the isooctane signal from day 2, but not when we used the air and isooctane signals from the same day. The artifacts were due to some inevitable drifts in the instrument between days; hence, the air signal must be measured as often as the instrument drift demands. With the proposed method, we showed that the absorption spectra could be approximately reproduced between days without any measurements of air. The proposed method merits consideration for process analytical technology (PAT) applications for example of continuous flow through an ATR cell where the introduction of a new substance (e.g., air or vacuum) for periodic baseline measurements is non-trivial.