bluuebunny/crossref_metadata_2025 huggingface dataset:
Caught The Flu? Exploring the novel role of high mobility group box 1 protein in severe influenza infection
Authors: Ma Danny
Published: February 2024

Severe influenza infections are a common cause of acute respiratory distress syndrome (ARDS). ARDS is characterized by acute lung injury as well as pulmonary edema or “leakage,” which is caused by endothelial dysfunction and subsequent alveolar flooding from circulating blood vessels. High mobility group box 1 (HMGB1) is a protein released from lung endothelial cells that acts as a proinflammatory cytokine during bacterial and viral infections. However, the effect of HMGB1 on the endothelium during influenza viral infection is unknown. This study demonstrates that HMGB1 released from primary human microvascular lung endothelial cells (HLMECs) during influenza infection increases endothelial activation and apoptosis, while also disrupting adherens junctions between cells. Sequestering extracellular HMGB1 using the small molecule glycyrrhizin (GCZ) attenuates these effects, suggesting that HMGB1 signaling occurs in a paracrine manner. Inhibition of the Toll-like receptor (TLR) 4 pathway, a downstream effector of HMGB1, with peptide P5779 did not substantially decrease endothelial apoptosis. Therefore, HMGB1 likely elicits its effects on the endothelium in a TLR4-independent manner. These results will elucidate a partial mechanism that potentially explains ARDS symptoms seen in patients with severe influenza infections.
Identifying genes associated with biofilm production in Pseudomonas aeruginosa
Authors: Chee Jessica
Published: February 2024

Pseudomonas aeruginosa is an opportunistic pathogen associated with a variety of life-threatening diseases. Infections caused by P. aeruginosa can be nearly untreatable because of its multidrug-resistance. One of the characteristics of P. aeruginosa that helps it survive in high drug concentrations is its ability to form biofilms–large communities of cells encompassed by extracellular polymeric substances that defend against many antibiotics. In fact, sub-minimum inhibitory concentrations of antibiotics stimulate biofilm production. This project aims to identify genes associated with biofilm induction in P. aeruginosa by screening a transposon mutant library for mutants that fail to show increased biofilm production when exposed to sub-minimum inhibitory concentrations of cefixime, tobramycin, and thiostrepton. So far, we have identified one gene, PA2714, that encodes a predicted molybdopterin oxidoreductase required for biofilm production. Because of the strong association between biofilm production and antibiotic tolerance in P. aeruginosa, the gene identified in this screen may be a useful therapeutic target for novel antimicrobialsthat can disrupt biofilm formation.
Nurses Prescribing
Authors: Kim Daniel
Published: February 2024

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Lupus: When the body attacks itself
Authors: Meducator The , Amir Takhliq , Xie Jim , Nagales Kien
Published: February 2024

Pathoprofile
Youth Tobacco Use: A pressing global health and human rights challenge
Authors: Meducator The , Lee Michael Yo-han , Panchal Puru
Published: February 2024

Youth smoking is prevalent in Indonesia. 90% of Indonesian childrenhave smoked a cigarette by age 13 and many remain as smokersinto adulthood. As a result of this addiction, many householdshave cigarettes as their second highest expenditure. Smokingis a considerable financial burden on families and the Indonesianhealth system. Previous international and domestic attempts toreduce Indonesian smoking rates from economic, political, andhealth systems fronts have not succeeded due to lobbying fromtobacco corporations. A stronger stance must be considered—oneof childhood development and a right to freedom from addiction.Advocating for physician-patient education, age limits, and childhoodeducation to key stakeholders in the federal government may helpleverage strategic foreign policies to internationally address thishuman rights issue.
Pacritinib: A novel therapeutic agent for treating myelofibrosis
Authors: Meducator The , Patel Kashyap , Zheng Ruby
Published: February 2024

Selective inhibitors are an important advancement in clinical medicine, providing a method to target proteins within signal transductionpathways. One such inhibitor, pacritinib, targets Janus Kinase 2 (JAK2) to treat patients with myelofibrosis (MF). In MF patients diagnosedwith a specific point mutation (JAK2V61F), the JAK/STAT pathway is over-activated, leading to an increase in cell proliferation rates.Pacritinib restores normal JAK/STAT activity by targeting aberrant activity of JAK2V61F mutant proteins and inhibiting cell proliferation inbone marrow tissue. In recent studies, pacritinib has shown better results at treating MF than the best available therapy. Though pacritinibis a potentially effective treatment option, it does not address all aspects of MF and should be supplemented with other treatments.
MedBulletin
Authors: Meducator The , Sadeghian Shadi , Zarb Sophie , Chopra Meera , Wong Adrian
Published: February 2024

MedBulletin
Homeopathy: Pseudo-Science or Effective Treatment?
Authors: Silverman Hannah , Yu Wendy
Published: February 2024

Homeopathy: Pseudo-Science or Effective Treatment?
MedBulletin
Authors: Wong Adrian , Song Nuri
Published: February 2024

Summaries of current news regarding: microRNAs (improving the ARDS patient experience), cannabinoids (elucidating the effects of CBD and THC on driving), Huntington's (heat shock proteins for treatment), and depression (insight into the neuronal circuitry).
Dr. David Lysecki
Authors: Dhillon Dalraj , Zhang Eric , Wang James , Lynn Matthew
Published: February 2024

Pediatric palliative care is often an overlooked field of medicine. As terminally ill children make up a small proportion of patients in Canada, a less robust network of resources is available to deliver end-of-life care for these patients. To gain a better insight into this field, we sat down with Dr. David Lysecki, a pediatric palliative care physician at McMaster Children’s Hospital. He is also the founder and head of the Quality of Life & Advanced Care program at McMaster Children’s Hospital and the Division of Pediatric Palliative Medicine in the McMaster University Department of Pediatrics.
MedBulletin
Authors: Tauseef Zahra , Chen Jacqueline , Wang Fan Ze , Dong Audrey
Published: February 2024

Summaries of current news regarding: artificial intelligence in early sepsis detection, glucocorticoids and COVID-19, a novel intervention for advanced prostate cancer, and CAR T-cell therapy for novel treatment of relapsed acute myeloid leukemia.
Indigenous Youth Resilience
Authors: Moss Corinne
Published: February 2024

This is an article about promoting indigenous youth resilience.
α-GalCer, an α-Candidate in Tumour Suppression
Authors: Gou David , Olejarz Matthew
Published: February 2024

Alpha-Galactosylceramide (α-GalCer, KRN7000) is an exogenous glycolipid ligand that is presented by CD1d molecules in antigen-presenting cells (APCs). It activatesinvariant natural killer T (iNKT) cells, characterized by semi-invariant T cell receptors (TCRs), which often leads to further downstream activation of the immune system. For example, iNKT cells release cytokines that regulate myeloid-derived suppressor cells (MDSCs) to promote tumor suppression. This critical review aims to clarify the observed effects of α-GalCer by examining recent studies, ranging from in vitro experiments with mice to in vivo clinical trials with humans. Within the current literature, α-GalCer has demonstrated beneficial effects toward tumour suppression. Most pre-clinical studies evaluating α-GalCer have seen success in suppressing tumour growth and increasing patient lifespan, although clinical trials yield inconclusive results. For example, the use of α-GalCer comes with severe limitations, including the induction of immune cell anergy amongst other unwanted side effects. Future studies and trials will be necessary to evaluate the full potential of α-GalCer. Nonetheless, α-GalCer may be a promising agent in combating cancer.
Magic Mushrooms
Authors: Alam Zahra , Soma Bhavana
Published: February 2024

Psilocybin is a naturally occurring compound present in numerous mushroom species characterised by its hallucinogenic and psychedelic effects. Although it has a negative reputation, psilocybin has demonstrated therapeutic potential for treating mental health disorders by allowing the brain to make new neural connections which help the neural pathways adapt and break out of certain cognitive patterns related to mental illness. In recent studies, psilocybin has shown antidepressant effects, significantly reducing depressive and anxious symptoms in affected individuals. After single or low dosage, mood disorder symptoms remained in remission for 6 to 12 months. In contrast, conventional antidepressants often require multiple doses over long treatment periods to achieve similar effects. Other findings have shown that therapeutic use of psilocybin helps combat substance abuse and addictive disorders and can be applied as a cessation tool. Despite years of controversy surrounding the benefits of psilocybin, recent scientific evidence supports psilocybin’s immense potential in helping those with mental health disorders like Major Depressive Disorder (MDD), Generalised Anxiety Disorder (GAD), Post Traumatic Stress Disorder (PTSD), Obsessive-Compulsive Disorder (OCD), and addiction disorders. With such promising results, psilocybin could be incorporated into clinical use and its therapeutic effects should continue being researched.
Currents of Change: Galvanic Vestibular Stimulation
Authors: Arora Parth , Tauseef Zahra
Published: February 2024

Galvanic vestibular stimulation (GVS) is an electrode-mediated method of non-invasive electrical stimulation. Its ability to modulate vestibular neuronal activity through electrical currents makes it a coveted diagnostic and therapeutic tool for vestibular and neurodegenerative disorders.
Although more robust clinical research is needed before wide-spread implementation, GVS shows promise as a safe, cost-effective, and accessible therapeutic tool for neurological rehabilitation.
Ongoing Debate on Medically-Assisted Death in Canada
Authors: Khattra Ruhani , Kim Olivia , Lu Jia
Published: February 2024

In 2016, Canada introduced Bill C-14, the Medical Assistance in Dying (MAiD) Act, providing an end-of-life care option for a rapidly increasing number of Canadians. MAiD includes active and passive methods, known as voluntary euthanasia – administered by a designated medical professional – and assisted suicide – the provision of medication by a medical professional to self-administer. The House of Commons and Senate passed Bill C-14 following The Supreme Court’s unanimous decision in Carter v Canada. This case challenged the prohibition of physician-assisted death, decreeing it an infringement on the Canadian Charter of Rights and Freedoms.
The (Step)motherly Ideal: The Role of Sex, Gender and Stereotype in the Aurore Gagnon Murder Trial
Authors: Nash Matthew
Published: February 2024

This essay examines the portrayal of Anne-Marie Houde in the media and her treatment by the criminal justice system in Quebec in the early twentieth century in the murder trial of her stepchild, ten-year-old Aurore Gagnon. Specifically, it argues that issues of sex, traditional gender roles, and the wicked stepmother stereotype played a role in her guilty conviction and harsh sentence, since other murderesses in this period were, quite literally, getting away with murder. By murdering her stepchild, Houde placed herself outside of the category of woman and denied herself the chivalrous treatment of the court. This is especially true since, as a stepmother, she faced immediate prejudice by the court and media. Furthermore, Houde manipulated her motherly role in a malicious fashion to contrive Aurore’s misbehaviour. In doing so, she exploited the perceived burden of these motherly duties to defame and arbitrarily punish Aurore.
Determinants of Physical Performanceand Physiological Responses Duringan Official Cross-Country Marathon ofMountain-Biking (Xcm-Mtb)
Authors: Saborosa Guilherme Pereira , Zuri Kallil Neves , Carneiro Túlio Junqueira , Melo Bruno Pereira , Pussieldi Guilherme de Azambuja , Manoel Francisco de Assis , Da Silva Sandro Fernandes
Published: February 2024

Introduction: The variables determinants of physical performance in cross-country marathon of mountain biking (XCM-MTB) are still unknown.
Objective: We aimed to verify the training control variables and the physiological responses in an official XCM-MTB race.
Material and methods: 13 athletes (11 men and 2 women; 33.3 ± 12.7 years of age) participated in this study. It was conducted during an official XCM-MTB in Brazil (route of 70 km). The heart rate (HR), altimetry, velocity, temperature, pacing, and power were obtained every 10 km travelled by the STRAVA application. Multiple linear regression analysis was performed to verify whether the variables could predict physical performance.
Results: The athletes maintained constant HR elevation in the corresponding zone 80% HRmax. They also presented a variation in the pacing (F = 35.82; p < 0.001; d = 0.66) and power (F = 7.20; p < 0.001; d = 0.18) showing higher values in the last 10 km. Only pacing can be considered a predictor of the physical performance (β = 0.958; t = 7.30; p < 0.001), specifically the one at 20 km (F = 10.23; p = 0.004; R2 = 0.82).
Conclusion: The study concluded that the analyzed variables are reliable for the performance control in an official XCM-MTB race. HR and power are variables that can be used to prescribe and control training, as they change according to the requirements of the race. Power can also be used as a performance predictor as it is directly influenced by terrain
Efectos del entrenamiento cluster sobre la hipertrofia muscular: Una revisión sistemática
Authors: Alarcón-Rivera Miguel , Benavides-Roca Luis , Guzmán-Muñoz Eduardo , Salazar-Orellana Cristian
Published: February 2024

Objective: The aim of this systematic review was to determine the effects of cluster training on musclehypertrophy.Methodology: A literature search was performed in the electronic databases Pubmed, Scopus and Web of Science,using the following keywords: “cluster training”, “rest interval”, “rest pause”, “hypertrophy”, “resistance training”and “cross sectional area”. We included clinical trials that used cluster training as an intervention in people over 18years of age of both sexes.Results: The systematic review obtained during the search of the databases consulted yielded a total of 23 potentially eligible articles, of which a sample of 9 was taken from which results could be obtained that responded to the objective of this review. The number of participants from the 9 eligible articles was 172 subjects. Cluster workouts allow for increased training volume and intensity without causing high levels of fatigue, thus favoring the development of musclehypertrophy.Conclusions: The results of this systematic review suggest that cluster training can be an effective tool for the development of muscle hypertrophy.
Caracterización acústica de fincas bajo pago por servicios ambientales en la Reserva Forestal Golfo Dulce, Costa Rica
Authors: Barrantes-Madrigal Jimmy , Retamosa Mónica , Bedoya-Arrieta Ricardo , Valerio-Madrigal Adriana , Sánchez-Alpízar Jonathan
Published: February 2024

[Introduction]: In Latin America, the sensitive tropical biodiversity found outside of protected wilderness areas is under threat. In Costa Rica, the payment for environmental services (PSA) represents a mechanism to protect forests on private farms, but it lacks specific indicators on the state of biodiversity and forest conservation. [Objective]: To analyze the use of acoustic monitoring for ecosystem assessment at 11 sites in the Osa Peninsula, nine on private farms, and two sites within Corcovado National Park. [Methods]: Soundscapes were recorded from May 25 to June 1, 2021, using acoustic recorders. It was analyzed the behavior of six acoustic indices at each sampling site and applied an automated detection analysis of vocalizations of two representative bird species of the area. [Results]: It was found that the most fragmented sites presented higher activity, energy, and acoustic diversity, possibly due to edge effects and ecotones present, as well as a high forest component in the surrounding matrix. Automated vocalization detection indicated that the species Hylopezus perspicillatus turned out to be more sensitive to differences in the landscape than Trogon bairdii. [Conclusions]: The use of acoustic indices, although it associates features of the degree of conservation, was not a differentiating element of the quality of the ecosystem in the evaluated farms. The monitoring ofspecies through the detection of their vocalizations was promising. A careful and rigorous sampling design, with moresampling points per site, is recommended to achieve accurate measurements and avoid bias in the analysis.
Refining Characteristics of Softwood Fibre Fractions
Authors:   Helsinki University of Technology, Laboratory of Paper Technology, Koskenhely Kari , Ämmälä Ari ,   University of Oulu, Laboratory of Fibre and Particle Technology, Jokinen Hanna ,   University of Oulu, Laboratory of Fibre and Particle Technology, Paulapuro Hannu ,   Helsinki University of Technology, Laboratory of Paper Technology
Published: February 2024

The role of refining intensity and specific energy in refining of softwood kraft fibre fractions was studied. Several paper properties can be improved by selective refining of fractions. The tensile strength-dewatering resistance relationship benefits from low-intensity refining of the long-fibre fraction. The specific energy input determines the increase in fibre swelling which contributes to a higher sheet density and improved tensile strength. The apparent density-roughness relationship benefits from mild refining of the short-fibre fraction. Refining intensity has a strong effect on the magnitude of the gap between bar surfaces, on fibre shortening, and on the coarseness of fibres with high cell wall thickness. For the short-fibre fraction, which appeared to flocculate less, the maximum intensity causing “pad collapse” and more severe fibre shortening was lower than for the long-fibre fraction and feed pulp. The fraction-specific intensity and gap behaviour are believed to relate to the compressibility of flocs under the stress applied by bar surfaces – a phenomenon discussed in recent studies concerning the forces acting on fibre flocs.
Fluid Mechanics of the Headbox Nozzle: Coherent Flow Structures, Instabilities and Disturbances Close to the Nozzle Exit
Authors:   Institute of Energy and Process Engineering, Tampere University of Technology, P.O.Box 589, FIN-33101 Tampere, Finland, Eloranta Hannu , Lepomäki Hannu ,   Metso Paper Inc., P.O. Box 587, FIN-40101 Jyväskylä, Finland, Pärssinen Tero ,   Institute of Energy and Process Engineering, Tampere University of Technology, P.O.Box 589, FIN-33101 Tampere, Finland
Published: February 2024

In this study two sources of flow instabilities in the headbox nozzle are presented. Both of them appear close to the nozzle exit and therefore are easily conveyed to the slice jet. This makes their control critical in the view of the jet quality. These instabilities may lead to so-called “small scale faults” in sheet quality, which appear as cockle, fiber orientation streakiness and other small-scale dimensional stability problems. The first source of instability is the nozzle exit itself. The geometry of the nozzle exit is highly asymmetrical due to the slice bar in the upper lip. This results in sudden acceleration and streamline curvature. The results show that remarkable alterations in the structure of the turbulent boundary layer on the lower lip are observed due to the acceleration generated by a slice bar model. However, compared to the boundary layer turbulence, the flow structures evolving in the slice bar shear layer are an order of magnitude stronger. In essence, the slice bar model utilized in the present experiment creates strong streamwise vortices. The other instability is related to the tip of the vane. Recent experimental work has revealed the reason for stable MD-aligned streaks in the mean-flow field created by some vanes at certain speeds. The streaks results from a fluid-structure interaction, in which the flow excites the vane to respond in a characteristic vibration mode. This paper presents the effect of flow rate, vane tip thickness and vane material on this kind of streaking problem. Also the fundamental nature of the fluid-structure interaction, responsible for enhanced vortex shedding which is the mechanism the streaks are generated, is explained.
Effect of Different Degradation Mechanisms on Axial and Z-directional Fiber Strength
Authors:   KCL Science and Consulting, P.O.Box 70, FIN-02151 ESPOO, FINLAND, Wathén Rolf , Joutsimo Olli ,   KCL Science and Consulting, P.O.Box 70, FIN-02151 ESPOO, FINLAND, Tamminen Tarja ,   KCL Science and Consulting, P.O.Box 70, FIN-02151 ESPOO, FINLAND
Published: February 2024

We have exposed pulp handsheets to two different degradative treatments, and compared their effects on strength properties. In accordance with earlier research, tensile stiffness and the shape of the stress-strain curve were independent of cellulose chain length and the fiber defects caused by the degradative treatments. When evaluated at the same viscosity, we found acid vapor treatment to be more detrimental to axial fiber strength than ageing treatment at elevated temperature and humidity. At the same mean fiber strength, acid vapor-treated handsheets show higher tensile strength. This is because acid vapor treatment is more heterogeneous than ageing treatment. The fiber network is able to compensate for the local defects, but not for the general degradation in fiber strength. In both treatments the mechanism for cellulose cleavage is assumed to be acid hydrolysis, the difference in the effect on fibers coming from the treatment conditions. Acid vapor treatment induces a fast reaction at defect sites and discontinuities in a fiber, while ageing treatment induces a slow, more homogeneous hydrolysis in fibers. Unlike axial strength, the Z-directional strength of softwood decreases only after harsh degradation when viscosity has dropped below 400 ml/g. The Z-directional strength of hardwood is already compromised at a viscosity of around 700 ml/g. The differences probably arise from differences in fiber ultrastructure.
Review: The Creep Response of Paper
Authors:   Department of Paper and Chemical Engineering, Miami University, Oxford OH 45056, Coffin Douglas W.
Published: February 2024

This article examines the literature pertaining to the creep behavior of paper. The basic concept of creep, the terminology used to describe creep, and the various ways to present creep are introduced. This is followed by a historical overview of creep in paper. Using this framework, discussions centered on tensile, compressive, and accelerated creep are presented. For years, research efforts have focused on accelerated creep. Because of this diversion, an acknowledged fundamental understanding of paper creep is lacking. Using previous data for tensile creep in constant humidity conditions, a rudimentary model of creep in paper is developed. The model clearly demonstrates that the role of bonding is accounted for simply with an efficiency factor that acts to magnify the stress. In addition to the impact of inter-fiber changes, intra-fiber effects resulting from hardening and wet-straining are demonstrated. It is suggested that compressive creep differs from tensile creep due to material instability. Accelerated creep is taken to be the result of moisture-induced load cycling. The result of this discourse is that to increase understanding, fundamental studies of creep behavior in constant conditions are and will be more fruitful than studies in cyclic humidity.
Influence of Fiber-Fiber Bonding on the Tensile Creep Compliance of Paper
Authors:   Institute of Paper Science and Technology at the Georgia Institute of Technology, Woodruff School of Mechanical Engineering, Atlanta, GA, USA, DeMaio Andrew , Patterson Timothy ,   Institute of Paper Science and Technology at the Georgia Institute of Technology, Woodruff School of Mechanical Engineering, Atlanta, GA, USA
Published: February 2024

In this study, two sets of sheets were made with differing levels of specific bond strength and relative bonded area. One set of sheets were wet pressed using a high press load and the other set of sheets were wet pressed using a low press load. Within each set, the sheets were treated with either a debonder or a bonder or received no treatment. Creep compliance data showed that creep curves for the debonder, bonder and untreated sheets were the same for the sheets wet pressed at the high press load and different for the sheets wet pressed at the low press load. Creep failure time was influenced by the treatments in both the high and low load wet pressed sheets; sheets treated with debonder failed first and the sheets treated with bonder failed last. It was concluded that at high levels of bonding as is the case with the high load wet pressed sheets, differences in specific bond strength due to the treatments do not influence creep deformation because fiber-fiber bonding is at a level where the sheets are efficiently loaded structures. The low load wet pressed sheets showed differences in creep deformation when specific bond strength was changed with treatments because fiber-fiber bonding was at a lower level where the sheets were inefficiently loaded. As the loading efficiency of the paper structure is improved through increased fiber-fiber bonding (either by increasing specific bond strength or relative bonded area), an efficiently loaded structure can be achieved where fiber-fiber bonding no longer affects deformation. This allows creep compliance to reach a minimum level which is dictated solely by the fibers. An efficiency factor can be used to describe deformation behavior where an efficiency of “1” indicates an efficiently loaded structure and lower values indicate a less than fully efficient structure, one in which fiber-fiber bonding influences deformation behavior. In this study, efficiency factors were used to scale the low load wet pressed sheet results and several sets of lesser refined and pressed sheets (thereby “removing” fiber-fiber bonding influence) and the data superimposed onto the high load wet pressed sheet results.
Effect of Fibre Shape and Fibre Distortions on Creep Properties of Kraft Paper in Constant and Cyclic Humidity
Authors:   STFI-Packforsk, Stockholm, Sweden, Panek Joel , Fellers Christer ,   STFI-Packforsk, Stockholm, Sweden, Haraldsson Tony ,   STFI-Packforsk, Stockholm, Sweden, Mohlin Ulla-Britt ,   STFI-Packforsk, Stockholm, Sweden
Published: February 2024

The purpose of this investigation was to study the effect of fibre shape and fibre distortions on the creep properties in constant and cyclic humidity and compare these data to other standard paper properties. The fibre shape and magnitude of fibre distortions were varied by low consistency beating and high consistency treatment of the pulp. The term virgin were used for these pulps. Furthermore the effect of drying history was investigated where papers from straight fibres were dried under restrained- and freely-dried followed by reslushing. The term re-dried were used for these pulps. Fibre shape and fibre distortions of the virgin pulps had different effects on the creep stiffness. Straight fibres with few distortions had the highest stiffness values. By making the fibres curlier, the creep stiffness decreased significantly. The presence of fibre distortions in the straight fibres had no effect on the creep stiffness. The creep stiffness of papers from re-dried pulps depended on the drying method that produced the fibres. Without beating, fibres of the freely-dried paper gave a lower stiffness than fibres of the restrained-dried paper. The fibres had a memory of the distortions that were introduced by the free drying. After beating, the difference due to the drying method disappeared.
Development of alternative methodology for normalization of the small animals PET scanner of LIM/CDTN
Authors: Silva Anna Clara Moreira da , Moreira Victória Garcia , Mendes Bruno Melo , Gontijo Rodrigo Modesto Gadelha , Ferreira Andrea Vidal
Published: February 2024

Normalization is a step taken to correct variations in count rates between detection channels of small animals PET scanners. In general, in laboratory practice, normalization is performed using a commercial source of germanium 68. Given the half-life of the Ge-68 isotope, the normalization source must be replaced every two years at most, which generates a significant spent for the Laboratory. The objective of this work was to develop and test an alternative rechargeable source to be used on normalization routine. The results indicated that the rechargeable source (18F-FDG) can be used to replace the commercial source.
How does ball lightning work?
Authors: Nikitin Anatoly I
Published: February 2024

The results of observations are described when ball lightning left material traces in the form of stone, metal balls, and molten metal after disappearing. There are also cases where ball lightning moved heavy objects over long distances: iron cages, people, magnets and even a train. This is explained by an assumption that the attraction of objects to ball lightning proceeds due to their polarization in its electric field and action of the electric field of clouds on it. Events are described when ball lightning dug trenches in wet soil and made deep holes in the ground. An explanation for these actions is given.
Birthplace of ball lightning
Authors: I Nikitin Anatoly
Published: February 2024

Examples of ball lightning formation at high altitude near a linear lightning channel are considered. A photograph of ball lightning emerging from a linear lightning channel is shown. It is shown that the process of ball lightning formation lasts no more than 30 ms. A model of ball lightning formation due to the action of a magnetic field pulse of a linear lightning current on the ionized volume of space is described. A scheme has been proposed to explain a rare event - the gathering of ball lightning from sparks. Cases of the formation of ball lightning at a large distance from the site of a linear lightning strike, when energy was transferred through wires, are considered. It is noted that the process of formation of such ball lightning and their properties differ markedly from ball lightning appearing near the channel of linear lightning. This made it possible to distinguish these objects into a special type of ball lightning. A model of the process of formation of such ball lightning is described, according to which their core consists of ions flowing from the electrode of an air electrical capacitor (antenna, power line), and the shell material is dust particles. Cases of observation of objects with a size of 50 microns - 1 mm appearing during electrical discharges in water are considered. The analogy of these objects with miniature ball lightning is shown.
Physico-chemical characteristics of microcrystalline cellulose from switchgrass (Panicum virgatum L.) obtained in the presence of a solid catalyst
Authors:   V.P. Kukhar Institute of Bioorganic Chemistry and Petrochemistry of National Academy of Sciences of Ukraine, Tkachenko T. V. , Haidai O. O. ,   V.P. Kukhar Institute of Bioorganic Chemistry and Petrochemistry of National Academy of Sciences of Ukraine, Kamenskyh D. S. ,   V.P. Kukhar Institute of Bioorganic Chemistry and Petrochemistry of National Academy of Sciences of Ukraine, Sheludko Y. V. ,   V.P. Kukhar Institute of Bioorganic Chemistry and Petrochemistry of National Academy of Sciences of Ukraine, Pavliuk O. V. ,   V.P. Kukhar Institute of Bioorganic Chemistry and Petrochemistry of National Academy of Sciences of Ukraine, Yevdokymenko V. O. ,   V.P. Kukhar Institute of Bioorganic Chemistry and Petrochemistry of National Academy of Sciences of Ukraine
Published: February 2024

The main idea of this work is the investigation of structural and morphological characteristics of microcrystalline cellulose with switchgrass (Panicum virgatum L.) by the method of organo-solvent cooking with the addition of various brands of ion-exchange resins instead of sulfuric acid. A sulfonated copolymer of styrene and divinyl benzene with two functional groups per ring - Purolite CT-275 and a sulfonated copolymer based on tetrafluoroethylene - Nafion NR-50 were chosen as initial ion exchange resins. Air-dry switchgrass (Panicum virgatum L.), a technical culture, was used for the research. Microcrystalline cellulose (MCC) was obtained from it by the method of organo-solvent cooking with the addition of a solid catalyst. Using the methods of XRD, FTIR-ATR, AFM, TGA and DSC, the structure and morphology of MCC were studied. It is found that the use of ion-exchange resins in the organo-solvent method of obtaining MCC in a batch reactor requires the use of protective covers for the catalyst to avoid its mechanical damage. It has been found that only sulfonated copolymers based on tetrafluoroethylene are stable in the cooking solution, in contrast to sulfonated copolymers of styrene and divinylbenzene, and allow obtaining MCC from millet with a yield of 53 % versus 40 % for the classical method and a degree of polymerization of 440 versus 578, respectively. Due to the destruction of amorphous binders in the MCC’s from switchgrass (Panicum virgatum L.), regardless of the conditions of its production, we observe further ordering of the structure of the obtained MCC which is expressed in narrower and more intense peaks in the range 2θ = 22–23°. The FTIR-ATR method showed that the obtained MCC has functional groups similar to commercial M-1021. The AFM method showed that MCC has a globular and wavy relief. Surface roughness with globular relief is 12.6 nm.
Mechanical, thermooxidative and biodegradable properties of composites from epoxyurethanes and chemically modified hemp woody core
Authors:   Institute of Macromolecular Chemistry of National Academy of Sciences of Ukraine, Samoilenko T. F. , Yashchenko L. M. ,   Institute of Macromolecular Chemistry of National Academy of Sciences of Ukraine, Yarova N. V. ,   Institute of Macromolecular Chemistry of National Academy of Sciences of Ukraine, Leta O. O. ,   Institute of Macromolecular Chemistry of National Academy of Sciences of Ukraine, Brovko O. O. ,   Institute of Macromolecular Chemistry of National Academy of Sciences of Ukraine
Published: February 2024

Natural fibre reinforced polymer composites nowadays are considered to be attractive cheap, safe and eco-friendly materials. The main problem of such composites related to the hydrophilicity of plant fibres may be successfully solved by chemical modification of their surface. However, some characteristics of the materials may be suppressed after this procedure. Therefore, the aim of the research is to find out the impact of chemical modification of filler on thermooxidative stability, tensile and flexural strength, as well as on biodegradability of polymer composites. The novelty of this work is in the examining new materials on the basis of Si-containing epoxyurethanes and chemically treated hemp woody core (HWC). Woody core that is the side product of hemp industry requiring its apropriate utilization was exposed to mercerization with sodium hydroxide solution and to further functionalization with epoxidized soybean oil (ESO) or 3-aminopropyltriethoxysilane (APS). Raw and surface treated HWC was used as reinforcement for two types of organic-inorganic epoxyurethane matrices made from sodium silicate, polyurethane prepolymer based on polyisocyanate and castor oil, and either diglycidyl ether of bisphenol-A (DGEBA) or ESO as epoxy component. Functionalization of HWC led to better mechanical properties of composites. Compared to the corresponding materials including untreated filler, maximum increase in flexural strength (26 %) was observed for the samples with ESO-containing epoxyurethane and silanized HWC, while maximum increase in tensile strength (53 %) was revealed for the ones with DGEBA-containing epoxyurethane and oil treated HWC. Thermooxidative stability was also higher for composites reinforced with functionalized HWC. The specimens with APS-treated HWC performed the best at thermal decomposition. The values of their T50% were up to 68 °C more than those for composites with unmodified filler. At the same time, the samples based on APS- or ESO-treated HWC were the most resistant to biodegradation, which may be concluded from their smallest weight loss during soil burial test.
Removal of cesium and strontium ions from aqueous solutions using metakaolin based geopolymers
Authors:   Institute for Sorption and Problems of Endoecology of National Academy of Sciences of Ukraine, Tarnovsky D. V. , Fedoryshyn O. S. ,   Institute for Sorption and Problems of Endoecology of National Academy of Sciences of Ukraine, Vyshnevskyi O. A. ,   M.P. Semenenko Institute of Geochemistry, Mineralogy and Ore Formation of National Academy of Sciences of Ukraine, Romanova I. V. ,   Institute for Sorption and Problems of Endoecology of National Academy of Sciences of Ukraine
Published: February 2024

The aim of presented work was to synthesize geopolymers based on the metakaolin and to determine their adsorption capability in the process of cesium and strontium ions removal from the aqueous solutions. New approaches were proposed for obtaining the two samples of geopolymers in techologically suitable forms. Morphology of materials was investigated by means of X-ray fluorescence analysis (XRF), low-temperature nitrogen adsorption/desorption and scanning electron microscopic studies (SEM). As it follow from the data of XRF analysis, SiO2 and Al2O3 oxides found to be the major components in all samples investigated (~ 54–84 wt. %). As was determined by SEM studies, geopolymers consisted from nanosized particles, amorphous geopolymers binder and unreacted kaolin. It has been found that all samples involve the mesopores with approx. 1–40 nm radii. The greatest specific surface area calculated by the Brunauer-Emmet-Teller (BET) method had the sample obtained in the forms of spherical rods (SBET = 88 m2/g) that about 10 times greater than for initial kaolin taken for synthesis. The ion exchange capacities of materials in the process of Cu2+, Cs+ and Sr2+ removal from water solution were determined and it was found that these properties depends on the method of materials obtaining. Data showed that the geopolymers were more effective for removal the desired ions than initial kaolin. The greatest adsorption capacity towards cesium ions was received on the samples obtained in forms of pyramids and was reached 1.75 mmol/g. Experimental data were fitted into the Langmuir models and the main Langmuir constants were calculated. When analysing the data of investigation with comparing the literature data it was noted that geopolymers obtained can be used in adsorption technology for purification of water from radionuclides as technologically suitable sorbents.
Structure and stability of MnOx-Na2WO4/SiO2 catalyst for oxidative condensation of methane
Authors:   Institute of Catalysis and Inorganic Chemistry Azerbaijan, Osmanova Sevinj , Azimova Gunel ,   Institute of Catalysis and Inorganic Chemistry Azerbaijan, Zulfugarova Sima ,   Institute of Catalysis and Inorganic Chemistry Azerbaijan, Ismailov Etibar ,   Institute of Catalysis and Inorganic Chemistry Azerbaijan, Taghiyev Dilgam ,   Institute of Catalysis and Inorganic Chemistry Azerbaijan, Thybaut Joris ,   Ghent University, Laboratory for Chemical Technology Belgium
Published: February 2024

Samples of MnOx-Na2WO4/SiO2 based on a mesoporous silica matrix were synthesized using manganese acetate, sodium tungstate, tetraethoxysilane (TEOS) as precursors and cetyltrimethylammonium bromide (CTAB), citric acid and triethanolamine as pore generating agent and characterized by scanning electron microscopy with energy dispersive elemental analysis (SEM/EDS), X-ray diffractometry (XRD), electron magnetic resonance (EMR), N2 adsorption-desorption measurements and tested as a catalyst for the reaction of oxidative condensation of methane (OCM). It is shown that the MnNaW/SiO2 catalyst consists of Mn2O3, MnO2, Na2WO4 and SiO2 phases. The EMR and SEM/EDS data indicate a noticeable effect of the reaction conditions on the surface structure and the distribution of catalytically active components in the catalyst structure. Significant changes in the values of the specific surface area and pore volume of the samples with increasing temperature and duration of the reaction were found (the values of the specific surface area and pore volume, respectively, 116.8 m2/g and 0.590 cm3/g - up to and 46.1 m2/g and 0.232 cm3/g after 15 hours of catalyst operation in the OCM reaction at 800 °C). It has been shown that under the conditions of the OCM reaction, the elemental composition of the surface of the MnOx-Na2WO4/SiO2 catalyst changes, and the degree of change depends on the duration of the OCM reaction. Under the influence of the reaction mixture CH4/O2, the content of Mn and W decreases in the first two hours, and the trend towards a decrease in their amount on the catalyst surface with an increase in the duration of the OCM reaction is generally preserved. A detailed X-ray phase analysis also indicates a change in the phase composition of this catalyst under the influence of the CH4/O2 reaction mixture. It is assumed that under the reaction conditions (700–800 °C) the MnOx-Na2WO4/SiO2 catalyst is silicon dioxide particles basely with the cristabolite structure, the surface of which is coated with molten sodium tungstate containing nanosized particles of MnOx structures activated by sodium ions and WOx.
Characterization of Integron Genes of Clinical Isolates of Pseudomonas aeruginosa which Perform Resistance to Antibiotics and Biofilm Formation by these Strains
Authors: Alfarras A.F. , Al-Daraghi W.A.
Published: February 2024

Pseudomonas aeruginosa is a bacterium that holds significant clinical and epidemiological significance. It serves as the principal etiological cause of opportunistic infections in individuals with impaired immune systems. Integrons are known to have a notable impact on Gram-negative bacteria, particularly in the context of P. aeruginosa, a bacterium recognized for its ability to develop resistance to antimicrobial drugs. Aim. To systematically characterize and detect integron genes (intI, intII, intIII) with antibiotic-resistant and biofilm-forming capabilities in isolated P. aeruginosa. Methods. A total of 209 samples were collected from Al Yarmouk Teaching Hospital in Baghdad City, Iraq to isolate P. aeruginosa. The process of bacterial identification was carried out phenotypically and by biochemical tests. Antibiotic susceptibility was measured using the Vitek2 system. Biofilm quantification was done by the microtiter method. The PCR approach was employed to assess the presence of class 1, 2, and 3 integrons. Results. P. aeruginosa was identified in 83 isolates by using a combination of morphological and biochemical examinations where all isolates showed the ability to grow a selective medium on cetrimide agar for P. aeruginosa. The results also showed significant variances (p < 0.05) among the percentage of a number of samples and isolated P. aeruginosa. The burn and wound infection scored the highest percentages (25% and 19%) based on the positivity of P. aeruginosa, whereas burn and ear sites scored the highest percentage (58% and 50%). Also, the isolates show the ability to form biofilm at a percentage of 68.7% with resistance to a high number of antibiotics. The multidrug-resistant and sensitive P. aeruginosa isolates scored high percentages (49.4% and 34.9%) whereas potentially pan drug-resistant and extensively drug-resistant isolates scored low percentages (2.4% and 13.3%). PCR results showed that integron I scored the highest percentage (100%) compared to integron 2 found in 3 (10%) isolates, and no intI3 gene was detected in any of the P. aeruginosa isolates. Conclusions. Overall, the findings of the present investigation indicate that integrons and biofilm development are recognized as significant factors contributing to antibiotic resistance in P. aeruginosa. The prevalence of class 1 integrons is shown to be significantly high in all bacterial isolates, with a complete occurrence rate of 100%. This high incidence of class 1 integrons is associated with the development of resistance to crucial antibiotics, including β-lactams, aminoglycosides, and cephalosporins.
Inhibition of Influenza Virus Reproduction by Active Components of «Proteflazidum» Flavonoid Composition: Putative Molecular Targets of Interaction
Authors: Arkhypova M.A. , Palchykovska L.G. , Platonov M.O. , Zavelevich M.P. , Deriabin O.M. , Atamaniuk V.P. , Starosyla D.B. , Rybalko S.L.
Published: February 2024

The search for substances possessing antiviral activities, in particular anti-influenza activity, is of importance for designing new drugs that may be effective in combating viral infections. The antiviral substances of the natural origin such as flavonoids and their derivatives are in the focus of numerous studies. The topical problem is the elucidation of the mechanisms of the interaction between flavonoid substances and the virus-specific targets in infected cells. Aim. To assess the activity of the flavonoid-enriched composition containing the biologically active substances of Proteflazidum against influenza virus in vitro and in vivo and to analyze in silico the putative interactions of the flavonoid components of the composition with PB2 subunit of viral RNA-polymerase. Methods. The anti-influenza effects of flavonoid-enriched composition prepared from the extracts of Deschampsia caespitosa L. and Calamagrostis epigeios L. were assessed in vitro in MDCK cells and in vivo in white outbred mice. Virion RNA was analyzed by RT-PCR with the primers detecting the transcripts of PB1 and PB2 subunits of viral RNA-polymerase and hemagglutinin. The potential interaction of the representative flavonoids of the composition with PB2 subunit of RNA-polymerase was analyzed in silico by molecular docking. Results. The composition under study inhibits effectively replication of А/FM/1/47 (H1N1) strain of influenza virus in vitro and protects the mice against flu infection both in therapeutic and preventive modes of its administration. According to the molecular docking findings, all three major flavonoid compounds of the composition, quercetin, luteolin, and apigenin, interact similarly with the PB2 domain of viral RNA-polymerase. Conclusions. The flavonoid composition containing the biologically active substances of Proteflazidum could be considered as the anti-flu drug with the PB2 subunit of viral RNA-polymerase being one of its potential molecular targets.
The Role of Bacteria as Basis on Pelagic Food Webs in Ultraoligotrophic Northern Patagonian Lakes: a Mini Review
Authors: De los Rios-Escalante Patricio
Published: February 2024

The northern Patagonian lakes are located in the South American Andes between 38—41° of Argentina and Chile. In their original stage, these lakes were described as ultraoligotrophic due the presence of perennial native forest that avoided the nutrients inputs from surrounding basin. The first studies described low phytoplankton abundances, but in recent studies, the presence of mixotrophic ciliates has been reported that may be a basis on trophic webs under the ultraoligotrophic status. They can graze on heterotrophic bacteria and nannoflagellates and can also do photosynthesis. Under the ultraoligotrophic status, the bacteria would have the basis on pelagial food webs because these would be grazed by zooplankton and mixotrophic ciliates. Nevertheless, when the lakes have a transition from oligotrophy to mesotrophy, although the bacterial biomass increases, they would not have an exclusive role because of a complex interaction between phytoplankton and grazer zooplankton.