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OBJECTIVE: To explore the different treatment modalities for esophageal gastrointestinal stromal tumors (E-GIST) and their respective applicability and clinical outcomes. METHODS: This is a retrospective study in which consecutive patients diagnosed with E-GIST at our hospital from January 2017 to August 2023 were included. The clinical characteristics of all the patients as well as long-term quality of life were recorded and analyzed. RESULTS: A total of 23 (12 males, 11 females) E-GIST patients with a mean age of 56.7 ± 12.0 years were included in this study. Common symptoms, including upper abdominal pain, acid reflux, and heartburn, accounted for over 60 % of cases. Fifteen patients underwent endoscopic resection, five patients underwent surgical resection, two patients underwent surgical resection after receiving preoperative imatinib therapy, and one patient received conservative management. CONCLUSION: Different treatment strategies may be applied to the patients with E-GIST depending on the their clinical features. Our study provides insights into precise treatment for different patients. However, due to the rarity of the disease, it is challenging to collect a large sample size from a single center, necessitating more multicenter prospective large-scale studies.
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In the last two decades, Nipah virus (NiV) has emerged as a significant paramyxovirus transmitted by bats, causing severe respiratory illness and encephalitis in humans. NiV has been included in the World Health Organization's Blueprint list of priority pathogens due its potential for human-to-human transmission and zoonotic characteristics. In this paper, a mathematical model is formulated to analyze the dynamics and optimal control of NiV. In formulation of the model we consider two modes of transmission: human-to-human and food-borne. Further, the impact of contact with an infected corpse as a potential route for virus transmission is also consider in the model. The analysis identifies the model with constant controls has three equilibrium states: the NiV-free equilibrium, the infected flying foxes-free equilibrium, and the NiV-endemic equilibrium state. Furthermore, a theoretical analysis is conducted to presents the stability of the model equilibria. The model fitting to the reported cases in Bangladesh from 2001 to 2015, and the estimation of parameters are performed using the standard least squares technique. Sensitivity analysis of the model-embedded parameters is provided to set the optimal time-dependent controls for the disease eradication. The necessary optimality conditions are derived using Pontryagin's maximum principle. Finally, numerical simulation is performed to determine the most effective strategy for disease eradication and to confirm the theoretical results.
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Infecções por Henipavirus , Vírus Nipah , Vacinação , Infecções por Henipavirus/prevenção & controle , Infecções por Henipavirus/epidemiologia , Infecções por Henipavirus/transmissão , Humanos , Animais , Quirópteros/virologia , Modelos Teóricos , Bangladesh/epidemiologiaRESUMO
The misuse of antibiotics has led to the global spread of drug-resistant bacteria, especially multi-drug-resistant (MDR) ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species). These opportunistic bacteria pose a significant threat, in particular within hospitals, where they cause nosocomial infections, leading to substantial morbidity and mortality. To comprehensively explore ESKAPE pathogenesis, virulence, host immune response, diagnostics, and therapeutics, researchers increasingly rely on necessitate suitable animal infection models. However, no single model can fully replicate all aspects of infectious diseases. Notably when studying opportunistic pathogens in immunocompetent hosts, rapid clearance by the host immune system can limit the expression of characteristic disease symptoms. In this study, we examine the critical role of animal infection models in understanding ESKAPE pathogens, addressing limitations and research gaps. We discuss applications and highlight key considerations for effective models. Thoughtful decisions on disease replication, parameter monitoring, and data collection are crucial for model reliability. By meticulously replicating human diseases and addressing limitations, researchers maximize the potential of animal infection models. This aids in targeted therapeutic development, bridges knowledge gaps, and helps combat MDR ESKAPE pathogens, safeguarding public health.
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Modelos Animais de Doenças , Farmacorresistência Bacteriana Múltipla , Animais , Humanos , Enterococcus faecium/efeitos dos fármacos , Enterococcus faecium/fisiologia , Pseudomonas aeruginosa/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Klebsiella pneumoniae/efeitos dos fármacos , Acinetobacter baumannii/efeitos dos fármacos , Infecção Hospitalar/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Enterobacter/efeitos dos fármacos , Infecções Bacterianas/microbiologiaRESUMO
Extensive studies are required to understand the behavior as well as prognosis of SS in the colorectal region. IHC staining is essential for the accurate diagnosis when a lesion is encountered at an unusual site.
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Hecogenin (HEC) is a steroidal saponin found in many plant species and serves as a precursor for steroidal drugs. The diuretic effects of HEC and its derivative, hecogenin acetate (HA), remain largely unexplored. The present study aimed to explore the potential diuretic effects of HEC and HA compared to furosemide (FUR) and spironolactone (SPIR). Additionally, the study aimed to explore the underlying mechanism particularly focusing on aldosterone synthase gene expression. Fifty-four Sprague-Dawley rats were allocated into nine groups (Group 1-9). Group 1 (control) received the vehicle, Groups 2 received FUR 10 mg/kg, Group 3, 4, and 5 were given HEC, while Groups 6, 7 and 8 received HA i.p at doses of 5, 10, and 25 mg/kg, respectively. Group 9 received SPIR i.p at the dose of 25 mg/kg. Urine volume, diuretic index and diuretic activity were monitored at 1, 2, 3, 4, 5, 6, and 24 h post-administration. Treatment was given daily for seven days. After that, rats were sacrificed and blood was collected for serum electrolytes determination. Adrenal glands were dissected out for gene expression studies. The results revealed that HEC and HA at the administered doses significantly and dose-dependently increased urine and electrolyte excretion. These results were primarily observed at 25 mg/kg of each compound. Gene expression studies demonstrated a dose-dependent reduction in aldosterone synthase gene expression, suggesting aldosterone synthesis inhibition as a potential mechanism for their diuretic activity. Notably, HA exhibited more pronounced diuretic effects surpassing those of HEC. This enhanced diuretic activity of HA can be attributed to its stronger impact on aldosterone synthase inhibition. These findings offer valuable insights into the diuretic effects of both HEC and HA along with their underlying molecular mechanisms.
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Detecting pipeline leaks is an essential factor in maintaining the integrity of fluid transport systems. This paper introduces an advanced deep learning framework that uses continuous wavelet transform (CWT) images for precise detection of such leaks. Transforming acoustic signals from pipelines under various conditions into CWT scalograms, followed by signal processing by non-local means and adaptive histogram equalization, results in new enhanced leak-induced scalograms (ELIS) that capture detailed energy fluctuations across time-frequency scales. The fundamental approach takes advantage of a deep belief network (DBN) fine-tuned with a genetic algorithm (GA) and unified with a least squares support vector machine (LSSVM) to improve feature extraction and classification accuracy. The DBN-GA framework precisely extracts informative features, while the LSSVM classifier precisely distinguishes between leaky and non-leak conditions. By concentrating solely on the advanced capabilities of ELIS processed through an optimized DBN-GA-LSSVM model, this research achieves high detection accuracy and reliability, making a significant contribution to pipeline monitoring and maintenance. This innovative approach to capturing complex signal patterns can be applied to real-time leak detection and critical infrastructure safety in several industrial applications.
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The oral cavity stands as one of the pivotal interfaces facilitating the intricate interaction between the human body and the external environment. The impact of diverse oral microorganisms on the emergence and progression of various systemic cancers, typified by oral cancer, has garnered increasing attention. The potential pathogenicity of oral bacteria, notably the anaerobic Porphyromonas gingivalis and Fusobacterium nucleatum, has been extensively studied and exhibits obvious correlation with different carcinoma types. Furthermore, oral fungi and viruses are closely linked to oropharyngeal carcinoma. Multiple potential mechanisms of oral microbiota-induced carcinogenesis have been investigated, including heightened inflammatory responses, suppression of the host immune system, influence on the tumor microenvironment, anti-apoptotic activity, and promotion of malignant transformation. The disturbance of microbial equilibrium and the migration of oral microbiota play a pivotal role in facilitating oncogenic functions. This review aims to comprehensively outline the pathogenic mechanisms by which oral microbiota participate in carcinogenesis. Additionally, this review delves into their potential applications in cancer prevention, screening, and treatment. It proves to be a valuable resource for researchers investigating the intricate connection between oral microbiota and systemic cancers.
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Some arthropod-borne obligate intracellular rickettsiae are among the most virulent human pathogens. Upon entry, Rickettsia species modulate immune (e.g., macrophages; MΦ) and non-immune cell (e.g., endothelial cells) responses to create a habitable environment for host colonization. In particular, MΦ play a crucial role in either terminating an infection at an early stage or succumbing to bacterial replication and colonization. However, our understanding on how Rickettsia species modulate crucial cellular processes within MΦ, including phagocytosis, and host cell defenses, to establish an intracytosolic replication niche, remain poorly defined. In this study, we describe a previously unappreciated mechanism, in which pathogenic rickettsiae infection is mediated by the phosphatidylserine (PS)-binding receptor, CD300f. We found that CD300f -/- mice but not wild-type (WT) C57BL/6J mice were protected against R. typhi - or R. rickettsii [ Shelia Smith ]-induced fatal rickettsiosis. Adoptative transfer studies further revealed that CD300f-expressing bone marrow-derived macrophages (BMDMΦ) are important mediators to control rickettsiosis in WT mice. Mechanistical analysis, using WT or CD300f -/- BMDMΦ, showed that CD300f facilitates the engulfment of both pathogenic R. typhi and R. rickettsii species, likely via a PS-mediated mechanism. Furthermore, CD300f was involved in the intracytosolic replication of both pathogenic rickettsiae by differentially modulating the anti-inflammatory Interleukin (IL)-10 and anti-rickettsial IL-1α and IL-1ß cytokine responses. Collectively, our findings describe a previously unappreciated role for the efferocytic receptor, CD300f, to facilitate engulfment and the intracellular survival of pathogenic rickettsiae within the host. Significance Statement: Vector-borne diseases, which are transmitted by hematophagous arthropods, like ticks and fleas, present a perilous threat to public health. In fact, tick- and flea-borne rickettsial diseases are on the rise globally and our current inadequate understanding on how Rickettsia interacts with their mammalian host has significantly impaired the development of effective interventions against pathogenic rickettsial infections. Here, we identified the phosphatidylserine (PS)-receptor, CD300f, as an important mediator of pathogenic rickettsiae infection in vivo and in vitro . Specifically, we showed that CD300f-expressing macrophages facilitate rickettsial infection by differentially modulating anti-inflammatory Interleukin (IL)-10 and anti-rickettsial IL-1α and IL-1ß cytokine responses. In sum, our data described CD300f as an important regulator of rickettsial infection and may present a target for therapeutic intervention.
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PURPOSE: To evaluate and contrast the contrast sensitivity defects present in strabismic and anisometropic amblyopes. And to find out the association of contrast deterioration with the visual acuity of the amblyopic eye, the magnitude of strabismus, and the amount of anisometropia in both groups. METHODS: This cross-sectional study was carried out in the orthoptics unit of a tertiary eye care facility between October 2021 and December 2021. There were 45 patients altogether. In the first phase, the patient's history and ocular examination data were recorded after informed consent. The Pelli-Robson chart was used to measure contrast sensitivity. In the second phase, results were interpreted using the SPSS (Statistical Package for the Social Sciences) version 26.0. RESULTS: Strabismic amblyopes were 24 and anisometropic amblyopes were 21. A significant positive association existed between both groups' contrast sensitivity and visual acuity (P = 0.000). A moderately negative correlation between contrast and anisometropia was statistically significant (P = 0.025) in anisometropic amblyopes. However, no association (P > 0.050) existed between the contrast and magnitude of strabismus in any group. CONCLUSION: The study concluded that contrast sensitivity decreases in both groups, whereas anisometropic amblyopes have poorer contrast than strabismic amblyopes. Excessively decreased contrast sensitivity among anisometropic amblyopes was solely because of the worst amblyopia in this group, whereas the magnitude of strabismus does not affect contrast sensitivity.
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OBJECTIVE: This study aims to investigate the efficacy and safety of snare traction-assisted endoscopic submucosal dissection (ESD) for the management of circumferential superficial esophageal cancer. METHODS: A total of 68 patients who underwent ESD for circumferential superficial esophageal cancer were included in this study. All the patients were divided into two groups based on whether the snare traction was used or not; the snare traction group (S-ESD, group n = 35) and the control group (C-ESD, group n = 33). RESULTS: There was no significant difference in the size of the resected area between the groups [21.98 (18.30, 27.00) cm2 vs 24.00 (15.28, 30.72) cm2, P = 0.976]. The snare traction group had a shorter dissection time [92.00 (74.00, 121.00) min vs 110.00 (92.50, 137.00) min, P = 0.017] and a faster resection speed [0.28 ± 0.13 cm2/min vs 0.22 ± 0.11cm2/min, P = 0.040] compared to the control group. There were no statistically significant differences between the two groups in terms of hospital stay, cost, en bloc resection rate, R0 resection rate, curative resection rate, bleeding rate, perforation rate, stricture rate, and recurrence rate (P > 0.05). CONCLUSION: Snare traction-assisted ESD is a safe and efficient approach for the treatment of circumferential superficial esophageal cancer. Its advantages includes shorter procedure so the anesthesia requirement, clear operative filed view, improved mucosal dissection efficiency, simple, and easily accessible equipment.
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Ressecção Endoscópica de Mucosa , Neoplasias Esofágicas , Humanos , Ressecção Endoscópica de Mucosa/métodos , Ressecção Endoscópica de Mucosa/instrumentação , Ressecção Endoscópica de Mucosa/efeitos adversos , Neoplasias Esofágicas/cirurgia , Neoplasias Esofágicas/patologia , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Resultado do Tratamento , Tração/métodos , Estudos Retrospectivos , Duração da Cirurgia , Esofagoscopia/métodosRESUMO
The spatial movement of the human population from one region to another and the existence of super-spreaders are the main factors that enhanced the disease incidence. Super-spreaders refer to the individuals having transmitting ability to multiple pathogens. In this article, an epidemic model with spatial and temporal effects is formulated to analyze the impact of some preventing measures of COVID-19. The model is developed using six nonlinear partial differential equations. The infectious individuals are sub-divided into symptomatic, asymptomatic and super-spreader classes. In this study, we focused on the rigorous qualitative analysis of the reaction-diffusion model. The fundamental mathematical properties of the proposed COVID-19 epidemic model such as boundedness, positivity, and invariant region of the problem solution are derived, which ensure the validity of the proposed model. The model equilibria and its stability analysis for both local and global cases have been presented. The normalized sensitivity analysis of the model is carried out in order to observe the crucial factors in the transmission of infection. Furthermore, an efficient numerical scheme is applied to solve the proposed model and detailed simulation are performed. Based on the graphical observation, diffusion in the context of confined public gatherings is observed to significantly inhibit the spread of infection when compared to the absence of diffusion. This is especially important in scenarios where super-spreaders may play a major role in transmission. The impact of some non-pharmaceutical interventions are illustrated graphically with and without diffusion. We believe that the present investigation will be beneficial in understanding the complex dynamics and control of COVID-19 under various non-pharmaceutical interventions.
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COVID-19 , Epidemias , Humanos , COVID-19/epidemiologia , Dinâmica não Linear , Simulação por Computador , DifusãoRESUMO
The economic impact of Human Immunodeficiency Virus (HIV) goes beyond individual levels and it has a significant influence on communities and nations worldwide. Studying the transmission patterns in HIV dynamics is crucial for understanding the tracking behavior and informing policymakers about the possible control of this viral infection. Various approaches have been adopted to explore how the virus interacts with the immune system. Models involving differential equations with delays have become prevalent across various scientific and technical domains over the past few decades. In this study, we present a novel mathematical model comprising a system of delay differential equations to describe the dynamics of intramural HIV infection. The model characterizes three distinct cell sub-populations and the HIV virus. By incorporating time delay between the viral entry into target cells and the subsequent production of new virions, our model provides a comprehensive understanding of the infection process. Our study focuses on investigating the stability of two crucial equilibrium states the infection-free and endemic equilibriums. To analyze the infection-free equilibrium, we utilize the LaSalle invariance principle. Further, we prove that if reproduction is less than unity, the disease free equilibrium is locally and globally asymptotically stable. To ensure numerical accuracy and preservation of essential properties from the continuous mathematical model, we use a spectral scheme having a higher-order accuracy. This scheme effectively captures the underlying dynamics and enables efficient numerical simulations.
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Infecções por HIV , HIV , Humanos , Modelos Biológicos , Número Básico de Reprodução , Simulação por ComputadorRESUMO
ß-lactoglobulin (BLG) is the major whey protein with negative charges at neutral pH in aqueous media. Thus, the interaction with mucins, the major polyanionic component of mucus, is very weak due to the electrostatic repulsion between them. The present study postulates that cationization of BLG molecules may reverse the interaction characteristics between BLG and mucin from repulsive to associative. To this end, cationic-modified BLGs were prepared by grafting positively charged ethylenediamine (EDA) moieties into the negatively charged carboxyl groups on the aspartic and glutamic acid residues and compared with non-modified BLG upon mixing with porcine gastric mucin (PGM). To characterize the structural and conformational features of PGM, non/cationized BLGs, and their mixtures, various spectroscopic approaches, including zeta potential, dynamic light scattering (DLS), and circular dichroism (CD) spectroscopy were employed. Importantly, we have taken surface adsorption with optical waveguide lightmode spectroscopy (OWLS), and tribological properties with pin-on-disk tribometry at the sliding interface as the key approaches to determine the interaction nature between them as mixing PGM with polycations can lead to synergistic lubrication at the nonpolar substrate in neutral aqueous media as a result of an electrostatic association. All the spectroscopic studies and a substantial improvement in lubricity collectively supported a tenacious and associative interaction between PGM and cationized BLGs, but not between PGM and non-modified BLG. This study demonstrates a unique and successful approach to intensify the interaction between BLG and mucins, which is meaningful for a broad range of disciplines, including food science, macromolecular interactions, and biolubrication etc.
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Cátions , Mucinas Gástricas , Lactoglobulinas , Animais , Suínos , Mucinas Gástricas/química , Mucinas Gástricas/metabolismo , Cátions/química , Lactoglobulinas/química , Lactoglobulinas/metabolismo , Dicroísmo Circular , Etilenodiaminas/química , Eletricidade Estática , AdsorçãoRESUMO
Introduction: Soil physicochemical properties and nutrient composition play a significant role in shaping microbial communities, and facilitating soil phosphorus (P) transformation. However, studies on the mechanisms of interactions between P transformation characteristics and rhizosphere microbial diversity in P-deficient soils on longer time scales are still limited. Methods: In this study, rhizosphere soils were collected from a pure plantation of Parashorea chinensis (P. chinensis) at six stand ages in the subtropical China, and the dynamic transformation characteristics of microbial diversity and P fractions were analyzed to reveal the variation of their interactions with age. Results: Our findings revealed that the rhizosphere soils across stand ages were in a strongly acidic and P-deficient state, with pH values ranging from 3.4 to 4.6, and available P contents ranging from 2.6 to 7.9 mg·kg-1. The adsorption of P by Fe3+ and presence of high levels of steady-state organic P highly restricted the availability of P in soil. On long time scales, acid phosphatase activity and microbial biomass P were the main drivers of P activation. Moreover, pH, available P, and ammonium nitrogen were identified as key factors driving microbial community diversity. As stand age increased, most of the nutrient content indicators firstly increased and then decreased, the conversion of other forms of P to bio-available P became difficult, P availability and soil fertility began to decline. However, bacteria were still able to maintain stable species abundance and diversity. In contrast, stand age had a greater effect on the diversity of the fungal community than on the bacteria. The Shannon and Simpson indices varied by 4.81 and 0.70 for the fungi, respectively, compared to only 1.91 and 0.06 for the bacteria. Microorganisms play a dominant role in the development of their relationship with soil P. Discussion: In conclusion, rhizosphere microorganisms in P. chinensis plantations gradually adapt to the acidic, low P environment over time. This adaptation is conducive to maintaining P bioeffectiveness and alleviating P limitation.
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In recent years, alcohol addiction has become a major public health concern and a global threat due to its potential negative health and social impacts. Beyond the health consequences, the detrimental consumption of alcohol results in substantial social and economic burdens on both individuals and society as a whole. Therefore, a proper understanding and effective control of the spread of alcohol addictive behavior has become an appealing global issue to be solved. In this study, we develop a new mathematical model of alcohol addiction with treatment class. We analyze the dynamics of the alcohol addiction model for the first time using advanced operators known as fractal-fractional operators, which incorporate two distinct fractal and fractional orders with the well-known Caputo derivative based on power law kernels. The existence and uniqueness of the newly developed fractal-fractional alcohol addiction model are shown using the Picard-Lindelöf and fixed point theories. Initially, a comprehensive qualitative analysis of the alcohol addiction fractional model is presented. The possible equilibria of the model and the threshold parameter called the reproduction number are evaluated theoretically and numerically. The boundedness and biologically feasible region for the model are derived. To assess the stability of the proposed model, the Ulam-Hyers coupled with the Ulam-Hyers-Rassias stability criteria are employed. Moreover, utilizing effecting numerical schemes, the models are solved numerically and a detailed simulation and discussion are presented. The model global dynamics are shown graphically for various values of fractional and fractal dimensions. The present study aims to provide valuable insights for the understanding the dynamics and control of alcohol addiction within a community.
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Alcoolismo , Comportamento Aditivo , Humanos , Fractais , Simulação por Computador , EtanolRESUMO
OBJECTIVE: To evaluate the feasibility, safety, and efficacy of massive continuous irrigation (MCI) and endoscopic debridement for the treatment of refractory abscess-fistula complexes. METHODS: This was a retrospective single-center observational study involving 12 patients with refractory abscess-fistula complexes. All patients had experienced long-term treatment failure or had failed multiple treatment modalities. We used over two catheters and inserted them via the gastrointestinal (GI) tract or percutaneously to form a circulation pathway to achieve MCI of normal saline, endoscopic debridement was then performed. The treatment success rate, irrigation volume and treatment duration, time to abscess-fistula complex closure, intra-treatment complications, and recurrence rate were recorded. RESULTS: The treatment success rates were 100%. The median time of previous treatment was 32 days (range 7-912 days). The mean time from the use of the novel treatment strategy to abscess-fistula complex healing was 18.8 ± 11.0 days. The mean volume of irrigation was 10 804 ± 1669 mL/24 h. The mean irrigation time was 16.5 ± 9.2 days, and a median of two irrigation tubes (range 2-5) were used. No complications occurred either during or after the procedure. During the follow-up of 23.1 ± 18.1 months, no recurrence or adverse events were noted. CONCLUSIONS: MCI and endoscopic debridement may be a feasible, safe, and effective alternative treatment for refractory abscess-fistula complexes. Large prospective studies are needed to validate our results.
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Abscesso , Fístula , Humanos , Abscesso/cirurgia , Abscesso/etiologia , Desbridamento/efeitos adversos , Desbridamento/métodos , Estudos Retrospectivos , Resultado do TratamentoRESUMO
This study introduces an innovative approach for fault diagnosis of a multistage centrifugal pump (MCP) using explanatory ratio (ER) linear discriminant analysis (LDA). Initially, the method addresses the challenge of background noise and interference in vibration signals by identifying a fault-sensitive frequency band (FSFB). From the FSFB, raw hybrid statistical features are extracted in time, frequency, and time-frequency domains, forming a comprehensive feature pool. Recognizing that not all features adequately represent MCP conditions and can reduce classification accuracy, we propose a novel ER-LDA method. ER-LDA evaluates feature importance by calculating the explanatory ratio between interclass distance and intraclass scatteredness, facilitating the selection of discriminative features through LDA. This fusion of ER-based feature assessment and LDA yields the novel ER-LDA technique. The resulting selective feature set is then passed into a k-nearest neighbor (K-NN) algorithm for condition classification, distinguishing between normal, mechanical seal hole, mechanical seal scratch, and impeller defect states of the MCP. The proposed technique surpasses current cutting-edge techniques in fault classification.
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The nitration reaction of aromatic compounds is one of the extensively studied chemical reactions that result in the manufacturing of various industrial products applied in pharmaceuticals, dyes, perfumes, and explosives. A series of modified sulfated zirconia (SZ) catalysts SO42-/ZrO2-MxOy (M=Ce, Co, Mn, Zn, and M/SZ) doped with different metal elements by a coprecipitation method were investigated in the toluene nitration reaction. Various characterization techniques (X-ray diffraction, Brunauer-Emmett-Teller, thermogravimetric analysis, X-ray photoelectron spectroscopy, and temperature-programmed desorption of ammonia) indicated that doping metal elements in SZ led to excellent catalytic properties, increasing the specific surface area of the catalyst and facilitating the formation of a stable tetragonal zirconia phase. Doping zinc and cobalt in SZ enhanced the acidity of the catalyst and formed stronger acidic sites, promoting the generation of nitronium ions and providing more active sites for the toluene nitration reaction. Additionally, it reduced the loss of sulfate ions in the catalytic system that helped in improving the stability of the catalyst. Under the same conditions, the catalytic activity of toluene nitration reaction demonstrated the following order: Zn/SZ > Ce/SZ > Co/SZ > Mn/SZ > SZ, with the zinc-doped SZ catalyst exhibiting the best catalytic performance, achieving a toluene conversion rate of 78.58% and a para/ortho nitrotoluene ratio of 0.67.
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In this article we report novel composite materials of bucky ball (C60 fullerene) and III-nitrides (BN, AlN, GaN, InN). The experimental feasibility of the novel composite materials is confirmed through negative binding energies and molecular dynamics simulations performed at 500 K. The structural properties of the novel composites are explored through density functional theory. An unusual phenomenon of surface bowing is observed in the 2D structure of the III-nitride monolayers due to the C60 sticking. This surface bowing systematically increases as one proceeds from BN â AlN â GaN â InN. The electron density difference and Hirshfeld charge density analysis show smaller charge transfer during the complexation, which is probably due to weak van der Waal's forces. The presence of van der Waal's forces is also confirmed by the Atom in Molecule analysis, Reduced Density Gradient Technique and Non-covalent Interaction analysis. This work provides a foundation for further theoretical and experimental studies of the novel phenomenon of systematic bowing in the 2D structure of III-nitride monolayers.
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The separation and purification of C6 cyclic hydrocarbons (benzene, cyclohexene, cyclohexane) represent a critically important but energy intensive process. Developing adsorptive separation technique to replace thermally driven distillation processes holds great promise to significantly reduce energy consumption. Here we report a flexible one-dimensional coordination polymer as an efficient adsorbent to discriminate ternary C6 cyclic hydrocarbons via an ideal molecular sieving mechanism. The compound undergoes fully reversible structural transformation associated with removal/re-coordination of water molecules and between activated and hydrocarbon-loaded forms. It exhibits distinct temperature- and adsorbate-dependent adsorption behavior which facilitates the complete separation of benzene, cyclohexene and cyclohexane from their binary and ternary mixtures, with the record-high uptake ratios for C6H6/C6H12 and C6H10/C6H12 in vapor phase and highest binary and ternary selectivities in liquid phase. In situ infrared spectroscopic analysis and ab initio calculations provide insight into the host-guest interactions and their effect on the preferential adsorption and structural transformation.