Killing Process Research Articles

Differential effects of dexmedetomidine on Gram-positive and Gram-negative bacterial killing and phagocytosis

Dexmedetomidine is a commonly used sedative in perioperative and intensive care settings with purported immunomodulatory properties. Since its effects on immune functions against infections have not been extensively studied, we tested the effects of dexmedetomidine on Gram-positive [Staphylococcus aureus and Enterococcus faecalis] and Gram-negative bacteria [Escherichia coli], and on effector functions of human monocytes THP-1 cells against them. We evaluated phagocytosis, reactive oxygen species (ROS) formation, and CD11b activation, and performed RNA sequencing analyses. Our study revealed that dexmedetomidine improved Gram-positive but mitigated Gram-negative bacterial phagocytosis and killing in THP-1 cells. The attenuation of Toll-like receptor 4 (TLR4) signaling by dexmedetomidine was previously reported. Thus, we tested TLR4 inhibitor TAK242. Similar to dexmedetomidine, TAK242 reduced E. coli phagocytosis but enhanced CD11b activation. The reduced TLR4 response potentially increases CD11b activation and ROS generation and subsequently enhances Gram-positive bacterial killing. Conversely, dexmedetomidine may inhibit the TLR4-signaling pathway and mitigate the alternative phagocytosis pathway induced by TLR4 activation through LPS-mediated Gram-negative bacteria, resulting in worsened bacterial loads. We also examined another α2 adrenergic agonist, xylazine. Because xylazine did not affect bacterial clearance, we proposed that dexmedetomidine may have an off-target effect on bacterial killing process, potentially involving crosstalk between CD11b and TLR4. Despite its potential to attenuate inflammation, we provide a novel insight into potential risks of dexmedetomidine use during Gram-negative infections, highlighting the differential effect of dexmedetomidine on Gram-positive and Gram-negative bacteria.

Establishment and validation of a novel integrin-based prognostic gene signature that sub-classifies gliomas and effectively predicts immunosuppressive microenvironment

ABSTRACT The integrin family members play a key role in cancer immunomodulation and prognosis. We comprehensively analyzed the expression patterns and clinical significance of integrin family-related genes in gliomas. A total of 2293 gliomas from the Cancer Genome Atlas (TCGA), Chinese Glioma Genome Atlas (CGGA) and Gliovis platform were enrolled for analyses. Twenty-six integrin coding genes showed different expression patterns between glioma and normal brain tissues. We screened an integrin family-related gene signature (ITGA5, ITGA9, ITGAE, ITGB7 and ITGB8) that showed independent prognostic value and sub-classified gliomas into different prognostic and molecular clusters, further composed an integrin-based risk score model associated with glioma malignant clinical features, overall survival (OS), and immune microenvironment alterations. Besides, glioma patients with high-risk scores showed chemotherapeutic resistance and more immune cells infiltration as well as high immune checkpoints expression. Concurrently, we also revealed that high-risk score group presented resistance to T cell-mediated cancer killing process and lower rates of response to immune checkpoint blockade (ICB) treatment. In conclusion, our study identified a valuable integrin gene signature that predicted gliomas OS effectively, and sub-classified them into different phenotypes and accompanied with immunological changes, possibly acted as a biomarker for ICB treatment.

Bioactive Constituents of Verbena officinalis Alleviate Inflammation and Enhance Killing Efficiency of Natural Killer Cells.

Natural killer (NK) cells play key roles in eliminating pathogen-infected cells. Verbena officinalis (V. officinalis) has been used as a medical plant in traditional and modern medicine for its anti-tumor and anti-inflammatory activities, but its effects on immune responses remain largely elusive. This study aimed to investigate the potential of V. officinalis extract (VO extract) to regulate inflammation and NK cell functions. We examined the effects of VO extract on lung injury in a mouse model of influenza virus infection. We also investigated the impact of five bioactive components of VO extract on NK killing functions using primary human NK cells. Our results showed that oral administration of VO extract reduced lung injury, promoted the maturation and activation of NK cells in the lung, and decreased the levels of inflammatory cytokines (IL-6, TNF-α and IL-1β) in the serum. Among five bioactive components of VO extract, Verbenalin significantly enhanced NK killing efficiency in vitro, as determined by real-time killing assays based on plate-reader or high-content live-cell imaging in 3D using primary human NK cells. Further investigation showed that treatment of Verbenalin accelerated the killing process by reducing the contact time of NK cells with their target cells without affecting NK cell proliferation, expression of cytotoxic proteins, or lytic granule degranulation. Together, our findings suggest that VO extract has a satisfactory anti-inflammatory effect against viral infection in vivo, and regulates the activation, maturation, and killing functions of NK cells. Verbenalin from V. officinalis enhances NK killing efficiency, suggesting its potential as a promising therapeutic to fight viral infection.

Abstract 812: Treatment of metastatic cancers using immunotherapeutic cowpea mosaic virus nanoparticles

Abstract This study investigates the use of an immunotherapeutic plant virus, namely the cowpea mosaic virus (CPMV), that when used prophylactically and therapeutically can protect against metastatic cancer in multiple tumor mouse models. Metastatic cancer continues to be the main cause of death of most cancer patients, and new treatment modalities must be engineered to protect patients from metastatic disease. For instance, peritoneal metastases (PMs) are oftentimes fatal, and patients survive for a median 6 months following diagnosis. PMs are common for colon, ovarian, gastric, appendiceal, and pancreatic cancers. Previously, it was demonstrated that CPMV is a potent in situ vaccine causing tumor shrinkage with abscopal effect and long-term protection observed in tumor mouse models and canine cancer patients. CPMV functions as a toll like receptor (TLR) agonist and acts on innate immune cells to induce tumor cell killing and antigen processing to eventually prime adaptative and tumor-specific immunity. However, metastatic cancers such as PMs are not easily and directly injectable and therefore, we have expanded the ability of CPMV to protect against PMs by engineering targeted CPMV nanoparticles. Data indicates that CPMV can improve survival and slow tumor growth in a murine colon PM model compared to controls and that long-term survivors are further protected from re-challenge indicating tumor specificity. Analysis from current and past studies indicate that CPMV injection into the intraperitoneal space leads to distinct upregulation of immunostimulatory cytokines and recruitment of innate immune cell populations. PMs lead to extreme declines in quality of life of patients, and current treatments can be ineffective in slowing down or reducing tumor development and death - in tackling this problem, the data clearly points to the strong potential for CPMV-mediated therapeutics in the treatment and prophylaxis of PMs. Dr. Steinmetz is a co-founder of and has a financial interest in Mosaic ImmunoEngineering Inc. The other authors have no conflict of interest to declare. Acknowledgments: This work is supported in part through NIH grants R01 CA274640, R01 CA224605, R01 CA253615, CDMRP W81XWH2010742, and the Shaughnessy Family Fund for Nano-ImmunoEngineering (nanoIE at UC San Diego). Citation Format: Young Hun Chung, Britney A. Volckaert, Nicole F. Steinmetz. Treatment of metastatic cancers using immunotherapeutic cowpea mosaic virus nanoparticles [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 812.

Dynamic well killing method based on Y-tube principle when the drill bit is off-bottom

The design of dynamic well killing parameters lacks theoretical support because the U-tube principle is not applicable while drilling bit is not at the well bottom. We present the Y-tube principle and establish a gas and liquid two-phase flow model with the killing fluid backflow and zero net liquid flow theory in wellbore below the drill bit. A dynamic well killing theory is proposed, and the variations of the well killing parameters are revealed. The results were as follows. (1) The Y-tube was composed of an annular part above the bit, a drillstring part, and a wellbore part below the bit. Gas–liquid flow models in those three parts were established to accurately simulate the dynamic well killing process when the drill bit was off-bottom. (2) Based on these models, the dynamic inflow and outflow curves during the killing period were obtained. The variations of the dynamic well killing parameters were analyzed by comparing the two curves. (3) With the increase of pressure, the critical gas velocity of blowout decreases, while the temperature, density and viscosity of the killing fluid do the opposite. With the increase of temperature, density and viscosity, and the decrease of the wellbore diameter, the bottom hole pressure increases. And it decreases with the decrease of the distance between the bit and wellhead. (4) Considering the actual well killing conditions, it is recommended to increase the critical blowout velocity by increasing the killing fluid surface tension and density, and to change the killing fluid density and viscosity so that the dynamic outflow curve is always above the dynamic inflow curve or the dynamic outflow curve is always above the formation pressure. As a result, the dynamic well killing will be successful when the bit is not at the well bottom.

Molecular and Antimicrobial Susceptibility Characterization of Escherichia coli Isolates from Bovine Slaughterhouse Process

Antimicrobials are routinely used in human and veterinary medicine. With repeated exposure, antimicrobials promote antibiotic resistance, which poses a threat to public health. In this study, we aimed to determine the susceptibility patterns, virulence factors, and phylogroups of E. coli isolates during the killing process in a bovine slaughterhouse. We analyzed 336 samples (from water, surfaces, carcasses, and feces), and 83.3% (280/336) were positive for E. coli. The most common phenotypic resistances that we detected were 50.7% (142/280) for tetracycline, 44.2% (124/280) for cephalothin, 34.6% (97/280) for streptomycin, and 36.7% (103/280) for ampicillin. A total of 82.4% of the isolates had resistance for at least one antimicrobial, and 37.5% presented multiresistance. We detected a total of 69 different phenotypic resistance patterns. We detected six other resistance-related genes, the most prevalent being tetA (22.5%) and strB (15.7%). The prevalence values of the virulence genes were 5.4% in hlyA, 1.4% in stx1, and 0.7% in stx2. The frequencies of the pathogenic strains (B2 and D) were 32.8% (92/280) and 67.1% (188/280) as commensals A and B1, respectively. E. coli isolates with pathogenic potential and multiresistance may represent an important source of dissemination and a risk to consumers.

Development of technological solutions for reliable killing of wells by temporarily blocking a productive formation under ALRP conditions (on the example of the Cenomanian gas deposits)

Modern field operation conditions are characterized by a decline in gas production due to the depletion of its reserves, a decrease in reservoir pressure, an increase in water cut, as well as due to the depreciation of the operating well stock. These problems are especially specific at the late stage of development of the Cenomanian deposits of Western Siberia fields, where the anomaly factor below 0.2 prevails, while gas-bearing formations are represented mainly by complex reservoirs with high-permeability areas. When killing such wells, the classical reduction of overbalance by reducing the density of the process fluid does not provide the necessary efficiency, which requires the search for new technical and technological solutions. In order to prevent the destruction of the reservoir and preserve its reservoir properties during repair work in wells with abnormally low reservoir pressure, AO “SevKavNIPIgaz” developed compositions of special process fluids. A quantitative description of the process of blocking the bottomhole formation zone is proposed by means of mathematical modeling of injection of a gel-forming solution into a productive horizon. The well killing technology includes three main stages of work: leveling the injectivity profile of the productive strata using three-phase foam, pumping the blocking composition and its displacement with the creation of a calculated repression. Solutions obtained on the basis of a mathematical model allow optimizing technological parameters to minimize negative consequences in the well killing process.

Genomic and Transcriptomic Profiling Reveal the Mechanism and Risk Factors of CD19-Negative Relapse after CAR-T Cell Therapy

Objection: To explore the relationship of mutation or alternative splicing events in CD19 coding region of patients underwent CD19-negative relapse after CAR-T cell therapy, as well as the predictive factors associated with relapse based on WES and RNA-seq, in the hope of explaining the mechanism of CD19-negativerelapse and improving the effect of CAR-T cell therapy. Methods: In this part of study, we collected bone marrow samples from R/R B-ALL patients underwent CD19 CAR-T cell therapy at baseline (T1) and relapse time (T2), then subjecting samples for WES and RNA-seq. Mutect and ANNOVAR software were used to detect single nucleotide variations (SNV) and indel mutations. Alphafold2 was used to predict the protein structure of CD19 after mutation. DESeq2 was used to compare the gene expression level between different groups; ssGSEA method was used to evaluate immunocyte infiltration level in each sample. Therefore, we displayed the potential mechanism of CD19-negative relapse from the aspects of leukemia cells and tumor microenvironment. Results:CD19 exon2-4 mutations were detected in CD19-negative relapse patients at relapse time, which lead to the change of protein structure of CD19 extracellular segment (Figure 1A). The combined analysis of WES and RNA-seq revealed common mutations of OBSCN at baseline and relapse (Figure 1D), which was associated with its continued lower expression in negative-relapse group (Figure 1B-C). Meanwhile, OBSCN was enriched in positive regulation of apoptosis pathway through GO enrichment (Figure 1E). OBSCN low-expression group had poorer 1-year leukemia free survival (LFS) rate (0% vs 44.4%, P=0.016) and long-term OS rate (P=0.027) than high-expression group (Figure 1G). Moreover, RHOH, a related gene of OBSCN, which expressed lower in CD19-negative relapse patients (Figure 1B-C). The 1-year LFS rate of RHOH high-expression group was significantly better than the compared group (44.4% vs 0%, P=0.001) (Figure 1H), and the infiltration level of TN, CD8+ effector memory T cells (TEM), memory T cells (TM) and tumor infiltrating lymphocytes (TILs) were increased in RHOH high-expression group (Figure 1F). Conclusion: Mutations of CD19 exon2-4 leads to the variation on protein structure, which hindered targeted killing process of CAR-T cells and finally resulted in CD19-negative relapse. On the other hand, OBSCN and RHOHmay play a role in promoting leukemia proliferation and decreasing apoptosis, and the lower expression of OBSCN and RHOH may be risk factors associated with CD19-negative relapse. In addition, lower expression of RHOH was unfavourable for the infiltration of TN, TEM, TM and TILs in tumor microenvironment, which lead to the weakening anti-tumor effect of immunocytes. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Spatiotemporal dynamics and Turing patterns in an eco-epidemiological model with cannibalism

In this work, we have studied the spatiotemporal dynamics and pattern formation in an eco-epidemiological model with cannibalism, which are not explored in the existing literature. Cannibalism is a process of killing and consuming the full or a part of an individual of the same species (conspecifics). A cannibalistic reaction–diffusion system is proposed and analyzed. In order to observe the change in system stability, we have investigated local and global asymptotic stability for the constant positive steady state. The existence of Hopf bifurcation and Turing instability are proved to understand the change in the system dynamics and to observe the species movement. Numerical simulation is performed to observe spatiotemporal dynamics and formation of Turing patterns. The existence of Hopf bifurcation is verified numerically in the spatiotemporal system It is observed that cannibalism stabilizes the temporal system, which is shown by bifurcation diagrams, phase portraits and time-series plots. Moreover, its increased cost promotes the occurrence of Turing patterns in the spatiotemporal system (i.e., checked numerically that for an increased cost of cannibalism, Turing instability holds). The movement of prey population also plays an important role in forming Turing patterns, as a significant change in movement results in various types of interesting two-dimensional Turing patterns such as hot-spot, stripe and labyrinth patterns. We see that both predator species show the same species distribution arrangements under cannibalistic pressure. Hence cannibalism can be seen as an essential factor for the significant change in spatiotemporal dynamics and species distribution arrangement.

Glycolysis in tumor microenvironment as a target to improve cancer immunotherapy.

Cancer cells and immune cells all undergo remarkably metabolic reprogramming during the oncogenesis and tumor immunogenic killing processes. The increased dependency on glycolysis is the most typical trait, profoundly involved in the tumor immune microenvironment and cancer immunity regulation. However, how to best utilize glycolytic targets to boost anti-tumor immunity and improve immunotherapies are not fully illustrated. In this review, we describe the glycolytic remodeling of various immune cells within the tumor microenvironment (TME) and the deleterious effects of limited nutrients and acidification derived from enhanced tumor glycolysis on immunological anti-tumor capacity. Moreover, we elucidate the underlying regulatory mechanisms of glycolytic reprogramming, including the crosstalk between metabolic pathways and immune checkpoint signaling. Importantly, we summarize the potential glycolysis-related targets that are expected to improve immunotherapy benefits. Our understanding of metabolic effects on anti-tumor immunity will be instrumental for future therapeutic regimen development.

On the Mechanistic Basis of Killer Meiotic Drive in Fungi.

Spore killers are specific genetic elements in fungi that kill sexual spores that do not contain them. A range of studies in the last few years have provided the long-awaited first insights into the molecular mechanistic aspects of spore killing in different fungal models, including both yeast-forming and filamentous Ascomycota. Here we describe these recent advances, focusing on the wtf system in the fission yeast Schizosaccharomyces pombe; the Sk spore killers of Neurospora species; and two spore-killer systems in Podospora anserina, Spok and [Het-s]. The spore killers appear thus far mechanistically unrelated. They can involve large genomic rearrangements but most often rely on the action of just a single gene. Data gathered so far show that the protein domains involved in the killing and resistance processes differ among the systems and are not homologous. The emerging picture sketched by these studies is thus one of great mechanistic and evolutionary diversity of elements that cheat during meiosis and are thereby preferentially inherited over sexual generations.

Visualization of natural killer cell-mediated killing of cancer cells at single-cell resolution in live zebrafish

Tumor immunotherapy has been an important advancement in cancer treatment in recent years. Compared with T cell-based therapy, natural killer (NK) cell-based therapy does not require human leukocyte antigen matching and has fewer side effects; thus, NK cell therapy has gradually attracted the attention of researchers and clinicians. Reliable and effective animal models are essential for evaluating the effects of NK cell therapy. NK cells kill cancer cells mainly through apoptosis. In this study, we first established a 3D coculture model using fluorescence resonance energy transfer (FRET)-based lung or breast cancer cells and tdTomato-labeled NK cells. We observed that cancer cells changed from green to blue when undergoing apoptosis induced by red NK cells. We then coinjected these green cancer cells with red NK cells into zebrafish to visualize the interaction between them and the killing process of NK cells against cancer cells in real-time and at single-cell resolution in circulation. Using this model, we found that NK cells can quickly kill cancer cells in zebrafish circulation in 40 min and the caspase-3 can be activated in 5–10 min. This FRET-based zebrafish tumor model can serve as a powerful in vivo tool that can facilitate the development of NK cell-based therapy. More importantly, cancer cells from cancer patients can be labeled with our apoptotic biosensor and then transplanted into zebrafish to evaluate the sensitivity of the cancer cells to NK cells to help clinicians make treatment plans that can benefit patients.

Developments in the Quantitative Assessment of Welfare Outcomes in Hunted Mammals Subject to Shooting

Knowledge gaps surrounding animal welfare assessment in hunted terrestrial wild mammals and seals were highlighted in the reviews by Knudsen (2005) and EFSA (2007). Following these reviews, the present paper aims to report on developments in the quantitative assessment of welfare outcomes in wild mammals killed via rifle shooting, and modern explosive harpoon grenades used in the killing of whales. Time to death (TTD) and instantaneous death rate (IDR) are widely accepted ante-mortem variables for assessing the duration of suffering during the killing process. The addition of post-mortem assessments allows for validation of TTD and IDR, thus providing a more accurate appraisal of animal welfare during hunting. While this combined assessment for large cetaceans has been implemented since the 1980s in the Norwegian minke whale (Balaenoptera acutorostrata) hunt, we report that this approach has been implemented in studies of the Icelandic minke and fin whale (Balaenoptera physalus) hunts, as well as the Canadian and Norwegian commercial harp seal (Pagophilus groenlandicus) hunts. Additionally, this approach has been incorporated into welfare studies in terrestrial herbivore management programmes. Quantitative welfare assessment during hunts is capable of effectively evaluating the weapons used and judging modifiable variables such as projectile choice, optimal shooting procedure, as well as identifying areas for improvement in hunter training. In moving towards a standardised approach for welfare outcome assessment, an established framework can effectively allow all hunts to be contrasted and allow for identification of optimal strategies that minimise animal suffering.

Analysis of Unreliable Narration in Edgar Allan Poe’s The Tell-Tale Heart

Edgar Allan Poe was a 19th century American poet, novelist and literary critic. His novel is recognized as the pinnacle of short gothic fiction, a unique existence in any era. The Tell-Tale Heart is a typical Gothic mystery novel of Edgar Allan Poe. The novel tells the process of a crazy young man killing an old man and the psychological changes during the process from a first-person perspective. Much researches had done at home and abroad about The Tell-Tale Heart, mainly around the narrative aesthetics, narrative style and the gothic style, etc., however, few researches focus on reliable narrative, this paper through the study of unreliable narration in The Tell-Tale Heart, let the reader get a better understand of his work The Tell-Tale Heart and Poe’s works.

Histopathology and transcriptome analysis reveals the gills injury and immunotoxicity in gibel carp following acute deltamethrin exposure

More and more evidences proved that deltamethrin (Del) exposure induced adverse effects and damaged immune function to the aquatic animals in the parasite killing process with increasing insecticide application. However, little is currently known of the negative effect on mucosal immunity, especially in gills tissue. Therefore, this study was aimed to reveal the tissue injury and immunotoxicity in the gill of gibel carp following acute deltamethrin exposure. The LC50 of deltamethrin on gibel carp at 96 h was determined to be 6.194 μg/L, and then juvenile gibel carp (Carassius auratus gibelio) (8.8 ± 1.0 g) were exposed to four Del exposure groups (0.61, 1.22, 2.44, and 4.88 μg/L) for 12 h and 24 h. We measured the lysozyme (LYZ) contents and myeloperoxidase (MPO) activities and found that with increased concentration of Del exposure, the LYZ contents were found to increase in the 1.22 μg/L Del group initially significantly and then gradually significantly decrease in the 4.88 μg/L Del group. And the activities of MPO were significantly lifted in a dose-dependent manner. The histological analysis showed that Del exposure caused serious desquamation and necrosis in the surface of epithelial cells, accompanied by interlamellar cellular mass degenerative. In addition, the mucous cells were significantly decreased in the high Del concentration group (2.44 μg/L and 4.88 μg/L Del group) by AB-PAS staining. Additionally, totally 2857 DEGs (including 1624 up-regulated and 1233 down-regulated genes) were identified between the control group and 4.88 μg/L Del exposure group using transcriptional analysis. Among these, some genes involved in innate immune molecules, complement activation, apoptosis-related molecules, cytokine, and adaptive immune molecules, were also down-regulated. Importantly, we found immune system process and tumor necrosis factor receptor (superfamily) binding pathways were downregulated based on the GO and KEGG enrichment analysis. Meanwhile, we detected the expression of pro-inflammatory cytokines (TNF-α, IFN-γ, IL-1β, and IL-8), anti-inflammatory cytokines (TGF-β), LYZ, IgM, and Hsp70 in the gills tissue at 12 h and 24 h after Del exposure, which were consistent with our sequencing results. Collectively, these results demonstrated that the gills injury and immunotoxicity were induced by Del exposure and provided novel insight for explaining to some extent why Del-exposure fish are more susceptible to concurrent or secondary viral or bacterial infections.

Natural killer cells kill extracellular Pseudomonas aeruginosa using contact-dependent release of granzymes B and H.

Pseudomonas aeruginosa is an opportunistic pathogen that often infects individuals with the genetic disease cystic fibrosis, and contributes to airway blockage and loss of lung function. Natural killer (NK) cells are cytotoxic, granular lymphocytes that are part of the innate immune system. NK cell secretory granules contain the cytolytic proteins granulysin, perforin and granzymes. In addition to their cytotoxic effects on cancer and virally infected cells, NK cells have been shown to play a role in an innate defense against microbes, including bacteria. However, it is not known if NK cells kill extracellular P. aeruginosa or how bacterial killing might occur at the molecular level. Here we show that NK cells directly kill extracellular P. aeruginosa using NK effector molecules. Live cell imaging of a co-culture of YT cells, a human NK cell line, and GFP-expressing P. aeruginosa in the presence of the viability dye propidium iodide demonstrated that YT cell killing of P. aeruginosa is contact-dependent. CRISPR knockout of granulysin or perforin in YT cells had no significant effect on YT cell killing of P. aeruginosa. Pre-treatment of YT and NK cells with the serine protease inhibitor 3,4-dichloroisocoumarin (DCI) to inhibit all granzymes, resulted in an inhibition of killing. Although singular CRISPR knockout of granzyme B or H had no effect, knockout of both in YT cells completely abrogated killing of P. aeruginosa in comparison to wild type YT cell controls. Nitrocefin assays suggest that the bacterial membrane is damaged. Inhibition of killing by antioxidants suggest that ROS are required for the bactericidal mode-of-action. Taken together, these results identify that NK cells kill P. aeruginosa through a membrane damaging, contact-dependent process that requires granzyme induced ROS production, and moreover, that granzyme B and H are redundant in this killing process.

Повышение технологической эффективности глушения скважин с использованием инновационных технологий

Introduction. The article considers the issue of assessing the technological efficiency of the well killing process, taking into account changes in the reservoir properties of the productive formation when using various compositions of process fluids. Innovative technologies are presented that are used when killing wells in various mining and geological conditions to block the bottomhole formation zone. Materials and methods of research. The study is based on a summary of many years of experience in the field of creation and practical use of process fluids for killing wells and on the results of theoretical, laboratory, bench studies of killing fluids and blocking compositions, performed in specialized scientific laboratories using specialized laboratory equipment according to standard methods for the oil and gas industry. Research results and discussion. The compositions of process fluids are presented, which are easily removed when inducing inflow from the formation, and which allow to provide the required pressure at the bottomhole, as well as to maintain the reservoir properties of the productive formation and prevent its damage. The results of killing wells with the use of various compositions of process fluids with high stability, low filtration, in a wide range of adjustable density and rheological properties, which allow creating the necessary repression on the formation and performing various operations in the well, are considered. The article also provides information on the analytical studies carried out within the framework of the given problem. The results made it possible to draw conclusions regarding the use of various types of fluids for killing oil, gas, gas condensate wells under conditions of abnormally low reservoir pressures and elevated reservoir temperatures. Consideration is given to the liquids with an acidsoluble condensable solid phase, the formation of which in solution is due to the occurrence of physicochemical processes between its components; biopolymer-based liquids containing various fillers and functional additives; viscoelastic compositions reinforced with solid-state lamellar and fibrous particles of organic and mineral origin (for example, bridging additive brand «OM-2C») based on commercially available polymer reagent «Binar»; emulsion-type kill fluids containing surfactants and a hydrocarbon phase. The main rheological and technological parameters, as well as the properties of the proposed process fluids for killing wells, are described. Сonclusions. Based on the study, it was determined that the most promising technology for killing wells under conditions of abnormally low formation pressures is the technology of preliminary blocking of the bottomhole formation zone using special compositions of process fluids with controlled rheological parameters, taking into account the characteristics of the formation, technologically applicable in special climatic conditions with low negative temperatures. It has also been established that ensuring high efficiency of repair work is impossible without performing theoretical calculations and laboratory studies with modeling the process of blocking the bottomhole zone during well killing and subsequent development.

Physical Hazards in Wild Ungulate Meat Harvested for Food Purposes: A Systematic Review

Meat safety includes the absence of physical hazards that has a potential of causing physical harm to consumers. Whilst there are physical hazards introduced in most in meat products, it is clear that some of the hazards, such as bullets particles and bone splinters, find their way in hunted wild ungulates in processes employed during killing. To assess the physical hazards that may occur in the game meat/venison industry, a systematic review of scientific literature published in English between 2000 and 2021 is conducted. The majority of studies evaluated and identified the risks of wild animal killing, which included fragmented bullets particles and bone splinters due to bones fracturing due to the killing process of game meat animals. Despite alternatives, such as the adoption of less fragmenting bullets, its compulsory implementation is proving a challenge in most countries.

Crocodylus siamensis Liver Extracts Exhibit Antimicrobial Activity and Induce Phagocytic Activity in Macrophage Cells

Antimicrobial peptides are documented as having a crucial role in innate immune response. Many reports have studied antimicrobial peptides from the crocodile. Thus, the antimicrobial activity of liver protein extract from Crocodylus siamensis was examined. Our results show that P50 and P80, partially purified crocodile liver protein extract at 45 mg/ml, can inhibit gram-positive bacteria with the highest percentages of inhibition at 48.22 % and 37.54 % respectively, while gram-negative bacteria could be inhibited at 47.31 % and 35.32 %, respectively. However, only P80 was selected for further phagocytosis activity investigation since it showed low cytotoxicity in the macrophage cell line. The results show that P80 can kill bacteria by an intracellular killing process in phagocytic cells of macrophages in a dose-dependent manner. Moreover, the internalization of phagocytosis activity of macrophages was assayed using fluorescein isothiocyanate-labeled Escherichia coli and flow cytometry. The results reveal that P80 can degrade bacteria by inducing phagosome formation in a time and dose-dependent manner (200-800 μg/ml). In these findings, the liver protein extract of Crocodylus siamensis had an enhancing effect on macrophage RAW 264.7 cells in the phagocytosis process.

A Critical Study of Postmodern Ethnicity and Psyche in Michael Ondaatje’s the English Patient

In this paper the researcher attempts to study about the postmodern ethnicity and psyche in the novel The English Patient. After exploring the status of World War II in the different debates that surround the concept of the ‘postmodernism’, the most obvious point is that even while the conflict was still underway, the second World War was identified as a crisis of modernity and also the loss of psyche. Since 1945, the scattering for survival and the killing process is often repeated. People started to hide their identity for survival after the second world war. After modernism the people started to problematize the problems. This novel The English Patient has the flavours of the interesting story line and suspicious past with some actual historical events. The novel also has the fragments of narratives, lives etc. Linda Hutcheon the postmodern theorist talks about the postmodern aspects like historiographic metafiction, self-reflective and intertextuality. This novel has the genre of Historiographic metafiction. The postmodern writings emphasis the earnestness of the historical records and they also allow us to think differently about the historical events. It relies heavily on parody of historical characters. This paper also studies about the most silenced character the English patient, so it comes under the positive postmodernism. In the postmodern aspect the researcher intends to find what made them to lose their identity, culture and why the characters suffered both physically and mentally. So, the post-world war period brings the changes in the San Girolamo villa of Italy which tells the most impactful story of the characters. According to the postmodernism it depends on the race, class, gender, and ethnicity what we consider as the proper knowledge.