Variable Resistance Research Articles

Varistor Insulation for HTS Magnets

A variable resistance thin dielectric insulation coating for REBCO tape HTS coils has been developed. This new type of insulation system switches between high and low resistance, after an increase in inter-turn voltage. Non-Insulated (NI), fully soldered, HTS coils have proven to be very reliable; NI coils are achieving high magnetic fields above 25 Tesla and are almost impossible to quench. Over-current operation simply redirects the excess current out of the superconducting tape, to flow radially through the coil then back to the power supply. The internal coil resistance can then run the current down when the power supply is switched off. The disadvantage with NI coils is, as the coil volume and inductance increase, the charging / discharging time can take many hours, even days. This is not compatible with magnet systems that need accurate and fast current to magnetic field control, such as accelerators or other systems. With the Varistor Insulation (VI) we aim to achieve both robust performances as seen in NI coils and fast ramping with controlled current to field transfer functions. In this paper we present the electrical characterization of the insulation at room temperature and cryogenic temperatures, along with simulated magnet operation during ramping, normal operation and failure modes. We discuss other features of the VI insulation such as, application methods to provide thin layers, and alternative formulations to tune its properties. Its ability to act as a distributed quench heater when the voltage threshold is exceeded is also discussed.

Resistant Uropathogens in Gulmi Hospital: High Time to Take Action

Introduction: Recent study in Nepal showed 29.5% culture positive cases of Urinary Tract Infections (UTIs). Extensive consumption of broad-spectrum antibiotics leading to increased AMR rates amongst uropathogens. This study has been carried out to determine the proportion and types of uropathogens causing infections and their antibiotics susceptibility pattern based on WHO classification of antibiotics- access, watch and reserve ('AWaRe') categories. Methods: Record review of the urine isolates with antibiotic susceptibility testing reported from Laboratory of Gulmi Hospital from April 2019 to April 2021. Ethics approval was obtained from Nepal Health Research Council (NHRC). Calculation of frequencies and proportions and cross-tabulation was done. Results: Bacterial yield was found in more than one-third of the total 315 samples. Majorities (84.48%) of them were gram negative bacteria. More than three-fourth of the urine isolates were of female. Urinary isolates showed variable resistance to the 'access' and 'watch' group of antibiotics. There was high resistance to the conveniently prescribed antibiotics like cefixime, ciprofloxacin, ofloxacin, for UTIs. Among tested urine isolates, 75.7% were sensitive to Nitrofurantoin. Conclusion: The yield of urine culture was 36.83% in our study with higher proportions in female. The resistance was high for conveniently prescribed antibiotics. Sensitive antibiotics like Nitrofurantoin were incorporated in the empirical therapy for UTI in this hospital after the study. It is an awakening call to implement measures to strengthen antimicrobial surveillance with inclusion of the peripheral hospitals to the reporting by capacitating them for quality reporting of the antibiograms.

Le Gegenhalten ou la paratonie. Revue narrative et conceptuelle

Better known in neurology by the expression paratonia coined by Ernest Dupré in 1907, the term Gegenhalten has remained dominant in psychiatry. While the term was created by Karl Kleist in 1927 to define a form of hypertonia in order to distinguish it from negativism, many current references continue to conflate the two concepts. Gegenhalten is the most frequent kind of hypertonia, and if its differential diagnosis with spasticity is generally easy, it is more difficult to distinguish it from parkinsonian rigidity, especially in psychiatric settings where antipsychotic-induced (or revealed) parkinsonism is frequent. Problematically, the most used evaluation scale for it, i.e., the Simpson-Angus scale does not allow for the distinction of Gegenhalten from parkinsonism. This could explain some of what is currently referred to as “spontaneous parkinsonism”, i.e., a hypertonia reported to occur in psychotic patients who are not taking any antipsychotic medication. Classical Gegenhalten is reactive, i.e., it occurs in the absence of an increase in resting tonus. It opposes an involuntary resistance during passive mobilization, the appearance of which is often delayed, or may only be perceptible after frequent repetitions. Thus, in the absence of a sensitization maneuver, minor forms of Gegenhalten may go undetected. Gegenhalten opposes a variable resistance. For instance, it depends on position (enhanced by gravitation) or emotional arousal. It can also be masked by a Mitmachen, a form of automatic assistance which is also of locomotor origin (like the Gegenhalten). While the French school of psychiatry saw Gegenhalten as a lack of voluntary control of muscle relaxation, Karl Kleist viewed it as an exacerbation of postural fixation reactions. For him, Gegenhalten could also occur “spontaneously” under the simple effect of gravity. Kleist hypothesized that spontaneous Gegenhalten was a kind of hypersensitive postural fixation reaction that could account for catatonic rigidity. These hypotheses were hotly debated at the beginning of the 20th century and stimulated considerable research. The growing interest in motor abnormalities in endogenous psychoses invites us to reconsider them. Unfortunately, they cannot be understood without a return to a refined semiology which has since been forgotten. This review is a first step in this direction.

A pareto optimal front of fluidic diode for a wave energy harnessing device

A twin-turbine or turbine duo (TUD) is constructed from a pair of unidirectional turbines. Flow reversal hampers the performance of these units. A Fluidic diode (FD) that offers a variable resistance to the flow can be used with TUD to prevent flow reversal, and its performance is governed by diodicity. With the increase in diodicity, flow blockage improves, but the resistance across the turbines increases too. As these turbines operate under a smaller pressure drop, the FD used with them should have higher diodicity with lesser fluid resistance across them. This study presents a multi-objective shape optimization of an FD to maximize diodicity and minimize pressure drop. The shape optimization is performed by simultaneously varying six design parameters. The performance of FD was evaluated by solving the 3D Reynolds Averaged Navier-Stokes equations. The popular evolutionary search algorithm (NSGA-II) with an artificial neural network produced a set of non-dominated optimal solutions (Pareto optimal set). Compared to the base model, the optimal design set shows improved diodicity from 17.2 to 21.57% and pressure drop from −2.535% to 78.67%, respectively. Further, the flow analyses of optimal designs show that the nozzle angle and the toroidal cup radius affect more than the other variables.

Acute effects of variable resistance training on force, velocity, and power measures: a systematic review and meta-analysis.

ObjectiveAcute effects of variable resistance training (VRT) and constant resistance training (CRT) on neuromuscular performance are still equivocal. We aimed to determine the differences between VRT and CRT in terms of force, velocity, and power outcomes.MethodsWe searched PubMed, Web of Science, and SPORTDiscus electronic databases for articles until June 2021. Crossover design studies comparing force, velocity, and power outcomes while performing VRT and CRT were included. Two reviewers independently applied the modified version of the Cochrane Collaboration’s tool to assess the risk of bias. A three-level random effects meta-analyses and meta-regressions were used to compute standardized mean differences (SMDs) and 95% confidence intervals.ResultsWe included 16 studies with 207 participants in the quantitative synthesis. Based on the pooled results, VRT generated greater mean velocity (SMD = 0.675; moderate Grading of Recommendations Assessment, Development and Evaluation (GRADE) quality evidence) and mean power (SMD = 1.022; low) than CRT. Subgroup analyses revealed that VRT considerably increased the mean velocity (SMD = 0.903; moderate) and mean power (SMD = 1.456; moderate) in the equated loading scheme and the mean velocity (SMD = 0.712; low) in the CRT higher loading scheme. However, VRT marginally significantly reduced peak velocity (SMD = −0.481; low) in the VRT higher loading scheme. Based on the meta-regression analysis, it was found that mean power (p = 0.014–0.043) was positively moderated by the contribution of variable resistance and peak velocity (p = 0.018) and peak power (p = 0.001–0.004) and RFD (p = 0.003) were positively moderated by variable resistance equipment, favoring elastic bands.ConclusionsVRT provides practitioners with the means of emphasizing specific force, velocity, and power outcomes. Different strategies should be considered in context of an individual’s needs. Systematic review registration: PROSPERO CRD42021259205.

Analysis and Design of Wireless Power Transfer Systems Applied to Electrical Vehicle Supercapacitor Charge Using Variable-Resistance-Based Method

Supercapacitors (SCs) are widely used as energy storage devices in many practical applications of wireless power transfer. However, the modeling and analysis of a wireless power transfer system are seldom based on SC load; thus, the effects of the charging process on the wireless power transfer system cannot be analyzed clearly. In this paper, a variable-resistance-based method is proposed for the modeling and analysis of the process of constant current charging. First, how to make an SC equivalent in variable resistance is described, and the relationship between SC and variable resistance is considered. Next, the charging process, including charging current, voltage, power and transfer efficiency, is analyzed in detail. Furthermore, the effects of transmitting side voltage and frequency offset on this system are studied, and the optimal design method for an SC-load WPT system is provided on a preliminary basis. Finally, the theoretical derivation and analysis are verified by means of simulations and experiments.

Hygrothermal Modelling of the Differences between Single versus Variable Relative Humidity Vapour Diffusion Resistivity Properties of Pliable Membranes

The study investigates through hygrothermal modelling the effect of different boundary conditions and varying measured vapour diffusion resistivity values on the hygrothermal performance of five pliable membranes. Previously, this research quantified the variable water vapour diffusion resistivity properties of five different pliable building membranes. The membranes were assessed under varying humidity conditions using the gravimetric wet and dry cup test method. The varying humidity conditions better represent the boundary conditions experienced by materials in the building envelope. The pliable membranes include two permeable, two impermeable, and one variable products, which are commonly used to provide air and vapour control layers in the construction of framed external wall systems. This article focusses on the transient hygrothermal modelling of each of these membranes as a component of a typical timber-framed, clay brick veneer external wall system. The simulations were completed for three different climate types, namely, hot and humid, temperate, and cool-temperate with snow, and with a northern and western orientation. The results from hygrothermal and bio-hygrothermal simulations highlighted different responses subject to climate type and orientation. These results show that there are significant differences in simulated moisture and mould growth risk between the results of pliable membranes with single vapour resistance factor value and pliable membranes with multipoint vapour resistance factor values.

Design of LDMOS Device Modeling Method Based on Neural Network.

The rapid development of power semiconductor devices is helping to realize a low-carbon society and provide a better life for everyone. Power semiconductors not only are used in many large-scale industrial control fields such as power transmission and control in power grids, rail transit traction systems, and defense weapons and equipment, but also play a vital role in daily equipment such as home appliances, medical electronics, and electronic communications; all devices such as power steering in cars, battery chargers, cell phones, and microwave ovens utilize power electronics. This research mainly focuses on the high-voltage LDMOS device model and its implementation. Based on the in-depth study of the structure and physical mechanism of high-voltage LDMOS devices, with the help of BSIM4 core model, which is now very mature and widely used in industry, the drift region of high-voltage LDMOS is mainly modeled, and the drift region of LDMOS is modeled as a variable resistance controlled by voltage. Finally, Verilog-A language and neural network method are used to establish a compact model of LDMOS. The improved model is applied to LDMOS and can better fit the output characteristics with self-heating effect.

Evaluation of common bean (Phaseolus vulgaris) genotypes for resistance to common bacterial blight and angular leaf spot diseases, and agronomic performances

Common bean is the most important pulse crops worldwide and in Ethiopia for its multipurpose uses. However, common bean production and productivity is mainly constrained by common bacterial blight (CBB) and angular leaf spot (ALS) diseases. Identifying and using resistant common bean genotypes is the best option to reduce the impact of such bacterial and fungal diseases. Field experiments were carried out to evaluate the genetic resistance of 25 common bean genotypes as treatments to CBB and ALS diseases, and agronomic performances at Haramaya and Melkassa, Ethiopia, during the 2019 and 2020 main cropping seasons. The treatments were arranged in a 5 × 5 triple lattice design with three replications. Data on disease intensity, growth, grain yield and yield components were recorded. Analysis of variance indicated significant (p < 0.0001) variations existed among the genotypes for diseases intensity, grain yield and yield components. Eight genotypes, namely DAB-388, DAB-478, DRKDDRB-70, DRKDDRB-81, NUA-225, NUA-517, NUA-536 and NUA-577 attained relatively low disease severity, AUDPC and disease progress rate next to the checks Zoasho (DAB-96) and Gorossa (Biofort large seed-5) to both common bean diseases regardless of locations and seasons. The genotype DAB-525 showed a moderately resistant reaction to both CBB and ALS, and the other genotypes demonstrated variable disease resistance reactions at both locations and in the two cropping years. Similarly, genotypes DAB-388, NUA-225, NUA-517, and NUA-577 relatively executed well for grain yield and yield components at both experimental fields in the 2019 and 2020 main cropping seasons. Disease severity and grain yield variably and negatively associated with reaction groups of genotypes evaluated for reaction CBB and ALS diseases. In the study, resistance to CBB and ALS diseases and good agronomic performing common bean genotypes were identified which could be important for smallholder and commercial bean production in the study area and other similar agro-ecologies in Ethiopia. It is suggested that a large number of common bean accessions should be evaluated in CBB and ALS hot spot agro-ecologies of Ethiopia for more sources of resistance and better agronomic advantages.

Class 1,2 Integron Genes Distribution in Pseudomonas aeruginosa Isolated from Clinical Specimens.

Pseudomonas aeruginosa, a Gram-negative human pathogen, P. aeruginosa is lone of the furthermost common hospital pathogens also is a chief concern, particularly in immune-compromised patients. The purpose of this study was to identify phenotypic and genotypic antibiotic resistance in Pseudomonas aeruginosa isolated from wound infection The bacterial isolates (30) were obtained from patients admitted to Mirjan Medical City in Babylon, Iraq (burns, wound unit). was identified biochemically and morphologically, and the isolates were subjected to standard bacteriological culturing processes on blood and MacConkey agar plates for 24-48 hours at 37oC for isolation and purification, Viteck 2 compact system confirmed the isolates and antibacterial sensitivity as well. These findings revealed that P.aeruginosa has a high rate of penicillin resistance, with a resistance rate of (100percent ) isolates. Advanced resistance to cephalosporin antibiotics was also found in resistant isolates of Cefoxitin, Ceftriaxone (75%), Ceftazidime, and cefepime (85%). For carbapenem antibiotics, had a high resistance rate (90percent). Aminoglycosides have variable resistance to Amikacin (60percent), Gentamicin (70 percent), and tobramycine resistant (90%). The findings revealed that all Pseudomonas aeruginosa isolates tested positive for Class 1,2 Integron resistance genes. with positive results (35%) for Int1 and 35% for Int2 (25%). This study found that P.aeruginosa has a high rate of resistance to Penicillins, Cephalosporin, Carbapenem and Aminoglycosides antibiotics.

Identification and validation of a siglec-based and aging-related 9-gene signature for predicting prognosis in acute myeloid leukemia patients

BackgroundAcute myeloid leukemia (AML) is a group of highly heterogenous and aggressive blood cancer. Despite recent progress in its diagnosis and treatment, patient outcome is variable and drug resistance results in increased mortality. The siglec family plays an important role in tumorigenesis and aging. Increasing age is a risk factor for AML and cellular aging contributes to leukemogenesis via various pathways.MethodsThe differential expression of the siglec family was compared between 151 AML patients and 70 healthy controls, with their information downloaded from TCGA and GTEx databases, respectively. How siglec expression correlated to AML patient clinical features, immune cell infiltration, drug resistance and survival outcome was analyzed. Differentially expressed genes in AML patients with low- and high-expressed siglec9 and siglec14 were analyzed and functionally enriched. The aging-related gene set was merged with the differentially expressed genes in AML patients with low and high expression of siglec9, and merged genes were subjected to lasso regression analysis to construct a novel siglec-based and aging-related prognostic model. The prediction model was validated using a validation cohort from GEO database (GSE106291).ResultsThe expression levels of all siglec members were significantly altered in AML. The expression of siglecs was significantly correlated with AML patient clinical features, immune cell infiltration, drug resistance, and survival outcome. Based on the differentially expressed genes and aging-related gene set, we developed a 9-gene prognostic model and decision curve analysis revealed the net benefit generated by our prediction model. The siglec-based and aging-related 9-gene prognostic model was tested using a validation data set, in which AML patients with higher risk scores had significantly reduced survival probability. Time-dependent receiver operating characteristic curve and nomogram were plotted and showed the diagnostic accuracy and predictive value of our 9-gene prognostic model, respectively.ConclusionsOverall, our study indicates the important role of siglec family in AML and the good performance of our novel siglec-based and aging-related 9-gene signature in predicting AML patient outcome.

Probiotic potential characterization and clustering using unsupervised algorithms of lactic acid bacteria from saltwater fish samples

This research aimed to isolate lactic acid bacteria from the bowel of saltwater fish to assess their potential probiotic properties. Nineteen isolates of LAB including Lactiplantibacillus plantarum, Lactiplantibacillus pentosus, Lactobacillus acidophilus, Levilactobacillus brevis, Pediococcus pentosaceus, and Pediococcus acidilactici were recognized using molecular tools. All the isolates survived in the simulated conditions of the GI tract. Auto-aggregation ranged from 01.3 ± 0.5 to 82.6 ± 1.4% and hydrophobicity with toluene ranged from 3.7 ± 1.6 to 69.4 ± 1.3%, while the range of hydrophobicity with xylene was from 02.2 ± 1.6 to 56.4 ± 2.1%. All the isolates of lactobacilli, pediococci, enterococci, and lactococci indicated variable sensitivity and resistance towards clinical antibiotics. Non-neutralized cell free supernatant of isolates F12 and F15 showed antimicrobial activity against all the 8 evaluated enteric pathogens. Cluster analysis of identified potential probiotic bacteria based on heat-map and PCA methods also highlighted the priority of isolates F3, F7, F12, and F15 as bio-control agents in fishery industry. The findings of this study may essentially contribute to the understanding of the probiotic potential of LAB in saltwater fish, in order to access their probiotic characterization for use as biocontrol in fishery.

Genomic surveillance reveals antibiotic resistance gene transmission via phage recombinases within sheep mastitis-associated Streptococcus uberis

BackgroundStreptococcus uberis is one of the main causative agents of ovine mastitis, however little is known about this global, environmental pathogen and its genomic mechanisms of disease. In this study, we performed genomic analysis on 46 S. uberis isolates collected from mastitis-infected sheep in Sardinia (Italy).ResultsGenomes were assigned into lineage clusters using PopPUNK, which found 27 distinct isolate clusters, indicating considerable genetic variability consistent with environmental isolates. Geographic trends were identified including regional linkage of several isolate clusters. Multi-locus Sequence Typing (MLST) performed poorly and provided no new insights.Genomes were then screened for antimicrobial resistance genes, which were compared to phenotypic resistance profiles. Isolates showed consistent phenotypic resistance to aminoglycosides with variable resistance to novobiocin and tetracycline. In general, identification of antimicrobial resistance genes did not correlate with phenotypic resistance profiles, indicating unknown genetic determinants. A multi-antimicrobial resistance cassette (aminoglycoside, lincosamide and streptogramin) was identified in the chromosome of three genomes, flanked by vestigial phage recombinases. This locus appears to have spread horizontally within discrete S. uberis populations within a 40 km radius (Sassari region).Genomes were screened for putative virulence factors, which identified 16 genes conserved between sheep and cow isolates, with no host-specific genes shared uniformly across all host-specific isolates.Pangenomic analysis was then performed to identify core genes which were putatively surface-exposed, for identification of potential vaccine targets. As all genomes encoded sortase, core genes were screened for the sortase cleavage motif. Of the 1445 core S. uberis genes, 64 were putative sortase substrates and were predominantly adhesins, permeases and peptidases, consistent with compounds found within ruminant milk such as xanthine, fibronectin and lactoferrin.ConclusionsThis study demonstrated the importance of whole genome sequencing for surveillance of S. uberis and tracking horizontal acquisition of antimicrobial resistance genes, as well as providing insight into genetic determinants of disease, which cannot be inferred from the MLST schemes. Future mastitis surveillance should be informed by genomic analysis.

A Device to Register Temperature in Boreholes in Northwest Spain for Geothermal Research.

This paper presents a device used to measure and register temperature for long-term subsoil measurements in boreholes. The borehole of this study is located in Gijón (Asturias, Spain). The measurements were made through two fixed sets of sensors coupled to the geothermal pipe, constituting two independent installations: (a) a commercial device called “Hobo”, which uses TMCx-HD-specific sensors based on resistors with variable resistance; and (b) a device built by this research group, which uses DS12B20 Maxim sensors, a bus 1-wire, and a recording device based on a conventional Arduino board. Temperature was registered every 5 min across several years. These measurements were used to thermally characterize the subsoil, determining the apparent thermal diffusivity, and to study the thermo-hydrogeology of the Lower Jurassic Gijón’s formation made of Liassic limestones and dolomites. This work is part of the Q-Thermie group’s research called “Shallow Thermal Energy”.

Antimicrobial Susceptibility Pattern of E. Coli in Patients with Urinary Tract Infection at a Tertiary Care Hospital, Rawalpindi

Background: Urinary tract infections caused by bacteria are the most prevalent type of hospital-acquired infection. They are also responsible for the greatest number of patient fatalities, lengths of hospital stays, and overall costs associated with medical care. Even though Escherichia coli is the bacteria that is found the most frequently, several studies have found different levels of prevalence for it. The current dilemma with antibiotic resistance is being caused, in large part, by the inappropriate and excessive use of antibiotics. Methodology: Laboratory records were searched in order to obtain information regarding the organisms that were isolated from urine samples as well as the pattern of antibiotic susceptibility. The urine samples that were obtained were processed according to the normal procedures, and a Kirby-Bauer Disk Diffusion test was used to determine the antibiotic susceptibility of the bacteria. Results: E. coli was found to be the most frequent causative agent of UTI (40.6%) followed by candida spp. (28%), Enterococcus spp (10.6%), Klebsiella spp (9.8%), Staphylococcus aures (1.58%) and Acinatobacter spp (1.97%). E. coli showed variable antimicrobial resistance to various antibiotics such as AMP (95.6%) followed by CRO (91.5%), CAZ (86.5%), CTX (82.09%), and MXF (80.8%) while most sensitive antibiotic was fosfomycin (93.2%) followed by sulzone (83.5%), imepinem (78.1%) and amikacin (77.1%). Keywords: Pathogens, susceptibility pattern, urinary tract infection

Improved Functional Assessment of Ischemic Severity Using 3D Printed Models.

ObjectiveTo develop a novel in vitro method for evaluating coronary artery ischemia using a combination of non-invasive coronary CT angiograms (CCTA) and 3D printing (FFR3D).MethodsTwenty eight patients with varying degrees of coronary artery disease who underwent non-invasive CCTA scans and invasive fractional flow reserve (FFR) of their epicardial coronary arteries were included in this study. Coronary arteries were segmented and reconstructed from CCTA scans using Mimics (Materialize). The segmented models were then 3D printed using a Carbon M1 3D printer with urethane methacrylate (UMA) family of rigid resins. Physiological coronary circulation was modeled in vitro as flow-dependent stenosis resistance in series with variable downstream resistance. A range of physiological flow rates (Q) were applied using a peristaltic steady flow pump and titrated with a flow sensor. The pressure drop (ΔP) and the pressure ratio (Pd/Pa) were assessed for patient-specific aortic pressure (Pa) and differing flow rates (Q) to evaluate FFR3D using the 3D printed model.ResultsThere was a good positive correlation (r = 0.87, p < 0.0001) between FFR3D and invasive FFR. Bland-Altman analysis revealed a good concordance between the FFR3D and invasive FFR values with a mean bias of 0.02 (limits of agreement: −0.14 to 0.18; p = 0.2).Conclusions3D printed patient-specific models can be used in a non-invasive in vitro environment to quantify coronary artery ischemia with good correlation and concordance to that of invasive FFR.

Requirements for technical preparation of volleyball players at the stage of initial training

The development of sportsmanship of volleyball players is directly related to the mastery of technique actions and the possibility of their use in competitions. This requires the study of the content of technical preparation starting from the stage of initial of preparation. Purpose: to determine the requirements for technical preparation of volleyball players at the stage of initial training on the basis of program and normative documents. Methods: theoretical analysis and generalization of data of scientific and methodical literature, synthesis, comparison, analogies, inductions and deductions, analysis of documentary materials, methods of mathematical statistics. Results. It have been clarified the basic tasks for the stage of initial training. They are mostly related to improving health, promoting proper physical development and versatile physical preparedness; development of special physical qualities and abilities; instilling a lasting interest to volleyball sessions; mastering the technique and tactics of the game (initial training, confident mastery); adaptation to game conditions and competition conditions; education of manifestations of volitional qualities in the conditions of variable resistance of the opponent. Determined shares within the technical preparation of young volleyball players, which are 39 hours, 44.82% (defensive actions) and 48 hours, 55.18% (offensive actions) in the first year of training, 44 hours, 44.00% (defensive actions) and 56 hours, 56.00% (offensive actions) in the second year of training and 43 hours, 46.24% (defensive actions) and 50 hours, 53.76% (offensive actions) in the third year of training at the stage of initial training in volleyball. The recommended stages of learning the technical elements are: getting acquainted with the techniques of playing volleyball, learning the techniques of the game and tactical interactions in simplified conditions, learning the techniques of the game and certain tactical interactions in conditions close to games, consolidating game techniques. Six tests are recommended to control the technical preparedness of volleyball players in all years of initial training. Conclusions. Implementation of technical preparation involves the study of a significant part of the technique actions during the stage of initial training. However, the implementation of the content of technical preparation does not have clear regulations on the use of tools and methods at the stage of initial training of volleyball players, which significantly expands the possibilities of scientific and practical search for effective methodological approaches.

Abstract 503: Longitudinal minimally invasive monitoring of resistance mutations in ALK rearranged lung cancer patients

Abstract Background: ALK is a proto-oncogene encoding the receptor tyrosine kinase ALK, which can be aberrantly activated by gene rearrangements or point mutations to promote tumor cell growth, survival, and metastasis. ALK rearrangements are detected in approximately 4% of patients with advanced non-small cell lung cancer (NSCLC), and the tyrosine kinase inhibitors (TKIs) crizotinib, alectinib, brigatinib, ceritinib, and lorlatinib have been approved by the FDA for the treatment of ALK-positive NSCLC. The durability of response to these therapies has been limited, in many cases, by the emergence of mutations that confer resistance to ALK. The major resistance mutation to alectinib, brigatinib, and ceritinib is the ALK G1202R solvent front mutation. The detection of resistance mutations has been improved with the evolution of biotechnology, making it possible to search for tumor-derived plasma free DNA as a liquid biopsy in cases where tissue biopsies are difficult to obtain. Digital PCR (dPCR) is an improved method of the conventional PCR method, which is more accurate and allows absolute quantification than the RT-PCR method. Materials and Methods: For a total of 9 patients, 2 patients newly diagnosed with ALK+ NSCLC by tissue biopsy and about to receive ALK-TKI and 7 patients already diagnosed with ALK+ NSCLC and receiving ALK-TKI, 10 ml of plasma was collected in addition to the blood collection at each 3-monthly visit. cfDNA was extracted and digital PCR was used to simultaneously detect 10 ALK mutations (T1151ins, C1156Y, L1196M, G1269A, F1174L, L1152R, V1180L, I1171T, G1202R, S1206Y). This Study was supported by an Investigator Initiated Research (IIR) from Pfizer. Results: The total number of samples analyzed in 9 cases was 65, and the median number of samples collected in each case was 7 (minimum 2 - maximum 12). cfDNA concentration was a median of 9.9 ng/ml of plasma (4.0-35.8 ng/ml). The number of samples detected for each mutation was 32 for G1202R, 16 for C1156Y, 5 for G1269A, 4 for F1174L, 1 for T1151ins, and 1 for I1171T. G1202R was detected in 19 of 37 samples during treatment with alectinib. The median time from detection of G1202R to clinical disease progression was 388 days (123-2004 days), with repeated emergence and disappearance in some cases. Conclusions: The dPCR method was highly sensitive in detecting gene mutations with low allele frequency. It was also found to be able to monitor variable resistance mutations over time during ALK-TKI treatment. In addition, we found that the appearance of G1202R did not always indicate clinical acquisition of resistance that required drug modification. A limitation of this study is that the mutations detected are not distinguishable between the same allele or Cis/trans. In particular, EML4-ALK forms a trimeric protein, suggesting that single mutations such as G1202R and drug susceptibility do not always match in clinical specimens. Citation Format: Takaaki Sasaki, Noriko Hirai, Yoshinori Minami, Shunsuke Okumura, Shin-ichi Chiba, Ryohei Yoshida. Longitudinal minimally invasive monitoring of resistance mutations in ALK rearranged lung cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 503.

Neural Network Based Calculation of Load Resistances Taking into Account the Multiport Input-to-Output Ratio Invariant Properties

The invariant properties of a multiport input-output ratio as a model of unstable two- and three-wire power supply lines of power loads or resistive sensors are considered. The fractional linear expressions typical for the electrical circuit theory are interpreted as projective transformations in the sense of projective geometry. Projective transformations preserve an invariant: a cross ratio or a duplicate proportion of four samples of variable resistance and the corresponding values of currents in different sections of the circuit. In this way, it becomes possible to calculate the load resistances from the measured current samples at the circuit input and their known base or test values; in doing so, the circuit parameters are not explicitly used. In turn, the base load values can also vary or are known with some uncertainty. To eliminate the influence of the variable parameters, neural networks are used for the calculation. For training the neural network, a set of possible values of the base resistances, loads, and the variable resistance of the multiport itself is specified. The corresponding set of input currents forms a training vector, and the load values are components of the target vector. Numerical experiments carried out in the Deep Learning package of the MATLAB system with one and two loads show the control calculation accuracy for the trained shallow neural network at a level of one to two percent.

CORRELATION BETWEEN BP VARIABILITY, INSULIN RESISTANCE AND MICROALBUMINURIA

Objective: Fueled by a global pandemic of cardiovascular diseases, hypertension (HT) remains the leading cause of early mortality in the world. Blood pressure variability (BPV) is considered to be in relation to a worse prognosis. Disrupted blood pressure variability (BPV) and insulin resistance (IR) often coexist as” satellite conditions”. This association potentiate the target organ damages (TOD). Microalbuminuria (MA) is an important biomarker of extra-cardiac damage, and subsequently, hypertension and/or carbohydrate metabolism’s alteration can lead to abnormalities in urinary albumin excretion. Each of these conditions can increase adverse hazards per se or via promoting hypertension or extracardiac injuries. Aim: To determine the correlation between disrupted BPV, level of carbohydrate metabolism’s alteration and microalbuminuria. Design and method: 101 patients with essential hypertension (49,5% men; mean age 50,11 ± 0,79 years, mean BMI 24.4 ± 0.5 kg/m2; eGRF &gt; 60 ml/min/1.73m2) with excessive BPV (systolic BP&gt; 15 mmHg; diastolic BP &gt; 14 mmHg), IR and microalbuminuria. Ambulatory blood pressure monitoring (ABPM), transthoracic echocardiography (TE), HOMA-IR and Ma were performed. The BPV was referred to the software analysis of ABPM data. To define IR was used The Homeostasis Model Assessment of insulin resistance (HOMAIR) levels; threshold values was considered &gt; 2. MA was appreciated according to the current guidelines (30–300 mg/24 h). Correlation analysis was performed using Pearson’s test. The correlation coefficient was considered weak at &lt; 0.3, medium-0.3–0.7 and strong&gt; 0.7–1.0. Statistical significance was appreciated at a P-value &lt; 0.05 and highly significant at a P-value &lt; 0.001. Results: Excessive BPV, HOMA-IR and MA indices demonstrate a statistically significant correlation (p &lt; 0.001). Systolic BPV demonstrated a particularly strong relationship with higher HOMA-IR levels and MA (p &lt; 0.05) (Table 1). Conclusions: In hypertensive patients, disrupted BP variability strongly correlates with microalbuminuria and carbohydrate metabolism abnormality. This association appears to have a particularly strong relationship with systolic BPV and correlates with higher HOMA-IR levels.