Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 74
Filtrar
1.
Open Forum Infect Dis ; 11(7): ofae328, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38989532

RESUMO

Background: Recent advances in shotgun metagenomic sequencing (sMGS) for detecting microbial cell-free DNA (mcfDNA) in peripheral blood have shown promise across various patient populations. This study evaluates the application of sMGS for diagnosing osteoarticular infections (OAIs), a condition with significant diagnostic challenges. Methods: We conducted a retrospective analysis on 73 patients suspected of OAIs at the Mayo Clinic from 2019 to 2023, incorporating mcfDNA sMGS (Karius test [KT]) into their diagnostic evaluation. We categorized the clinical impact of KT on OAI diagnoses and management into 4 distinct outcomes. (1) KT was able to confirm an established diagnosis, (2) KT supported noninfectious diseases diagnosis, (3) KT established an unsuspected diagnosis, (4) KT did not add relevant information. Results: In our cohort, KT was performed in 73 patients. Among the infected individuals, KT yielded positive results in 22 of 43 (51.2%) cases. Of these 22 cases, 11 (50%) showed agreement with conventional diagnostic workup, whereas in 5 (22.7%) cases, the KT established an unsuspected diagnosis. Native vertebral osteomyelitis diagnosis (P < .001) or OAIs with concomitant presence of endocarditis or endovascular infection (P = .005) were statistically associated with a definite, probable, or possible diagnostic certainty of KT result. Conclusions: In complex OAIs, KT enhanced diagnostic accuracy by 11.6%, proving especially beneficial in diagnosing native vertebral osteomyelitis and infections with concurrent endocarditis or endovascular complications. Our findings underscore the utility of KT in the diagnostic workflow for challenging OAI cases, potentially altering clinical management for a significant subset of patients.

2.
J Bone Jt Infect ; 9(3): 173-182, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39040990

RESUMO

In recent years, there has been a notable increase in research output on native vertebral osteomyelitis (NVO), coinciding with a rise in its incidence. However, clinical outcomes remain poor, due to frequent relapse and long-term sequelae. Additionally, the lack of a standardized definition and the use of various synonyms to describe this condition further complicate the clinical understanding and management of NVO. We propose a new framework to integrate the primary diagnostic tools at our disposal. These collectively fall into three main domains: clinical, radiological, and direct evidence. Moreover, they and can be divided into seven main categories: (a) clinical features, (b) inflammatory biomarkers, (c) imaging techniques, microbiologic evidence from (d) blood cultures and (e) invasive techniques, (f) histopathology, and (g) empirical evidence of improvement following the initiation of antimicrobial therapy. We provide a review on the evolution of these techniques, explaining why no single method is intrinsically sufficient to formulate an NVO diagnosis. Therefore, we argue for a consensus-driven, multi-domain approach to establish a comprehensive and universally accepted definition of NVO to enhance research comparability, reproducibility, and epidemiological tracking. Ongoing research effort is needed to refine these criteria further, emphasizing collaboration among experts through a Delphi method to achieve a standardized definition. This effort aims to streamline research, expedite accurate diagnoses, optimize diagnostic tools, and guide patient care effectively.

3.
Dermatol Ther (Heidelb) ; 14(4): 829-840, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38615134

RESUMO

The experience of itch often poses a burden on patient quality of life and has the capacity to inflict significant suffering. Topical therapies are a mainstay of treatment for many cutaneous and systemic diseases and afford patients the opportunity to manage their conditions without many of the systemic side effects of non-topical therapies. We review a multitude of new topical medications targeting the skin, immune system, and neural receptors. The list includes Janus kinase inhibitors, tyrosine kinase inhibitors, phosphodiesterase inhibitors, transient receptor vanilloid inhibitors, topical cannabinoids, and topical acetaminophen. Many of the topical therapies reviewed show promising data in phase 2-3 clinical trials, but further research is needed to compare therapies head-to-head and test their efficacy on a broader range of conditions.

4.
PLoS Pathog ; 20(3): e1012038, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38489257

RESUMO

Ebola disease (EBOD) remains a significant and ongoing threat to African countries, characterized by a mortality rate of 25% to 90% in patients with high viral load and significant transmissibility. The most recent outbreak, reported in Uganda in September 2022, was declared officially over in January 2023. However, it was caused by the Sudan Ebola virus (SUDV), a culprit species not previously reported for a decade. Since its discovery in 1976, the management of EBOD has primarily relied on supportive care. Following the devastating outbreak in West Africa from 2014 to 2016 secondary to the Zaire Ebola virus (EBOV), where over 28,000 lives were lost, dedicated efforts to find effective therapeutic agents have resulted in considerable progress in treating and preventing disease secondary to EBOV. Notably, 2 monoclonal antibodies-Ebanga and a cocktail of monoclonal antibodies, called Inmazeb-received Food and Drug Administration (FDA) approval in 2020. Additionally, multiple vaccines have been approved for EBOD prevention by various regulatory bodies, with Ervebo, a recombinant vesicular stomatitis virus-vectored vaccine against EBOV being the first vaccine to receive approval by the FDA in 2019. This review covers the key signs and symptoms of EBOD, its modes of transmission, and the principles guiding supportive care. Furthermore, it explores recent advancements in treating and preventing EBOD, highlighting the unique properties of each therapeutic agent and the ongoing progress in discovering new treatments.


Assuntos
Vacinas contra Ebola , Ebolavirus , Doença pelo Vírus Ebola , Vacinas Virais , Humanos , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/prevenção & controle , Anticorpos Antivirais , Ebolavirus/genética , Anticorpos Monoclonais/uso terapêutico , Uganda/epidemiologia
5.
Mol Biol Rep ; 51(1): 346, 2024 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-38401017

RESUMO

BACKGROUND: Infectious agents associated with community-acquired acute respiratory infections (ARIs) remain understudied in Lebanon. We aim to assess the microbiological profiles of ARIs by employing polymerase chain reaction (PCR) and identifying predictors of positive PCR results among patients admitted for ARI. METHODS AND RESULTS: We conducted a retrospective single-center study at the American University of Beirut Medical Center, including all respiratory PCR panels performed on pediatric (< 18) and adult (≥ 18) patients presenting with an ARI from January 2015 to March 2018, prior to the onset of the COVID-19 pandemic. We aimed to identify the epidemiological patterns of ARIs and the factors associated with positive PCRs in both adult and pediatric patients. Among 281 respiratory PCRs, 168 (59.7%) were positive for at least one pathogen, with 54.1% positive PCR for viruses, 7.8% for bacteria species, and 3.9% with virus-bacteria codetection. Almost 60% of the patients received antibiotics prior to PCR testing. PCR panels yielded more positive results in pediatric patients than in adults (P = 0.005). Bacterial detection was more common in adults compared to pediatrics (P < 0.001). The most common organism recovered in the entire population was Human Rhinovirus (RhV) (18.5%). Patients with pleural effusion on chest CT were less likely to have a positive PCR (95% Cl: 0.22-0.99). On multivariate analysis, pediatric age group (P < 0.001), stem cell transplant (P = 0.006), fever (P = 0.03) and UTRI symptoms (P = 0.004) were all predictive of a positive viral PCR. CONCLUSION: Understanding the local epidemiology of ARI is crucial for proper antimicrobial stewardship. The identification of factors associated with positive respiratory PCR enhances our understanding of clinical characteristics and potential predictors of viral detection in our population.


Assuntos
Infecções Respiratórias , Vírus , Adulto , Humanos , Criança , Lactente , Reação em Cadeia da Polimerase Multiplex/métodos , Estudos Retrospectivos , Líbano/epidemiologia , Pandemias , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/microbiologia , Vírus/genética
6.
Arch Pharm (Weinheim) ; 357(5): e2300742, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38290054

RESUMO

Aging and agro-waste are major challenges. Natural ingredients are preferred in skincare. This study intended to isolate the essential oils (EO) from the leftover peels obtained from three commonly edible Citrus species fruit peels, namely Citrus paradisi (grapefruit), Citrus sinensis (sweet orange), and Citrus deliciosa (mandarin). Gas chromatography/mass spectrometry analysis identified volatile constituents in EO and headspace aroma. Multivariate analysis distinguished between the three species. The antiaging effects of Citrus EO were assessed in vitro and in silico, studying volatile interactions with target enzymes. C. sinensis peels had the highest oil yield, rich in monoterpenes. C. paradisi and C. deliciosa contained sesquiterpenes. Limonene dominated the hydrodistilled EO: 94.50% in C. paradisi, 96.80% in C. sinensis, and 80.66% in C. deliciosa. Unsupervised multivariate analysis of Citrus species revealed that  d-limonene, γ-terpinene, and ß-pinene are the key phytochemical markers contributing to their diverse chemical composition. C. paradisi exhibited the highest enzyme inhibitory activity, with IC50 values of 12.82, 27.58, and 18.16 µg/mL for tyrosinase, elastase, and collagenase, respectively. In silico studies showed that the volatiles can inhibit the tested antiaging enzymes. According to these findings, the investigated agro-waste might slow aging in skin care.


Assuntos
Citrus , Cromatografia Gasosa-Espectrometria de Massas , Óleos Voláteis , Citrus/química , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Análise Multivariada , Frutas/química , Humanos
7.
Am Surg ; 90(6): 1268-1278, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38225880

RESUMO

Across the nation, patients with locally advanced gastric cancer (LAGC) are managed with modalities including upfront surgery (US) and perioperative chemotherapy (PCT). Preoperative therapies have demonstrated survival benefits over US and thus long-term outcomes are expected to vary between the options. However, as these 2 modalities continue to be regularly employed, we sought to perform a decision analysis comparing the costs and quality-of-life associated with the treatment of patients with LAGC to identify the most cost-effective option. We designed a decision tree model to investigate the survival and costs associated with the most commonly utilized management modalities for LAGC in the United States: US and PCT. The tree described costs and treatment strategies over a 6-month time horizon. Costs were derived from 2022 Medicare reimbursement rates using the third-party payer perspective for physicians and hospitals. Effectiveness was represented using quality-adjusted life-years (QALYs). One-way, two-way, and probabilistic sensitivity analyses were utilized to test the robustness of our findings. PCT was the most cost-effective treatment modality for patients with LAGC over US with a cost of $40,792.16 yielding 3.11 QALYs. US has a cost of $55,575.57 while yielding 3.15 QALYs; the incremental cost-effectiveness ratio (ICER) was $369,585.25. One-way and two-way sensitivity analyses favored PCT in all variations of variables across their standard deviations. Across 100,000 Monte Carlo simulations, 100% of trials favored PCT. In our model simulating patients with LAGC, the most cost-effective treatment strategy was PCT. While US demonstrated improved QALYs over PCT, the associated cost was too great to justify its use.


Assuntos
Análise Custo-Benefício , Árvores de Decisões , Anos de Vida Ajustados por Qualidade de Vida , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/terapia , Neoplasias Gástricas/economia , Neoplasias Gástricas/patologia , Estados Unidos , Qualidade de Vida , Gastrectomia/economia , Técnicas de Apoio para a Decisão , Análise de Custo-Efetividade
8.
Expert Rev Clin Immunol ; 20(1): 31-37, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37847514

RESUMO

INTRODUCTION: Patients with chronic kidney disease (CKD) undergoing hemodialysis often experience significant itch secondary to their condition and a subsequent reduction in their overall quality of life. Current treatments are underwhelming, necessitating the search for new, effective therapeutic options to combat itch in this population. AREAS COVERED: The purpose of this review is to explore the available data for the use of intravenous difelikefalin in patients with CKD undergoing hemodialysis. The pathophysiology of CKD-associated itch is multifactorial, with one proposed mechanism involving an imbalance in the endogenous opioid system, favoring upregulation of itch-activating µ-opioid receptors (MORs) and downregulation of itch-inhibiting κ-opioid receptors (KORs). Dysregulation of the immune system is also involved. Difelikefalin is a recent FDA approved treatment that functions as peripherally acting KOR agonist, targeting this imbalance in the endogenous opioid system seen in CKD patients with itch and having an anti-inflammatory effect on immune cells. Clinical data on intravenous difelikefalin is promising regarding its ability to reduce itch in CKD patients on hemodialysis and improve patient quality of life, with few, mild adverse side effects. EXPERT OPINION: As intravenous difelikefalin becomes more widely used in the clinical setting, further studies assessing long-term efficacy and safety will be needed.


Assuntos
Analgésicos Opioides , Insuficiência Renal Crônica , Humanos , Analgésicos Opioides/uso terapêutico , Qualidade de Vida , Diálise Renal , Prurido/tratamento farmacológico , Prurido/etiologia , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/terapia , Receptores Opioides kappa/agonistas , Receptores Opioides kappa/uso terapêutico
9.
Ital J Dermatol Venerol ; 158(5): 401-407, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37916400

RESUMO

Keloids occur after cutaneous injury and can cause distress due to physical appearance and associated symptoms such as pain and pruritus. Keloid-associated pruritus is a common manifestation and has negative impacts on quality of life. The mechanism underlying this type of pruritus is multifactorial and thought to involve small nerve fiber damage, neurogenic inflammation, and a Th2-predominant inflammatory response. Various agents have been shown to reduce keloid pruritus, including intralesional corticosteroids, botulinum toxin A, 5-fluorouracil, and bleomycin. Other treatment modalities such as cryotherapy and hyperbaric oxygen therapy are also effective. Future treatments targeting the mechanisms involved in keloid-associated itch could provide improvements in pruritus and quality of life in these patients, but further studies on the efficacy of these agents are needed.


Assuntos
Queloide , Prurido , Humanos , Crioterapia/efeitos adversos , Queloide/complicações , Queloide/terapia , Queloide/patologia , Dor/etiologia , Prurido/terapia , Prurido/complicações , Qualidade de Vida , Inflamação
10.
Front Mol Neurosci ; 16: 1272230, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37849619

RESUMO

Similar to chronic pain, chronic itch is frequently linked to neural sensitization, a phenomenon wherein the nervous system becomes hypersensitive to stimuli. This process of neural sensitization of chronic itch is orchestrated by various signaling pathways and mediators in both the peripheral and central nervous systems. At the level of the peripheral nervous system, inflammation and neuroimmune interactions induce plastic changes to peripheral nerve fibers, thereby amplifying the transmission of itch signaling. Neural sensitization in the central nervous system occurs at both the spinal cord and brain levels. At the level of the spinal cord, it involves hyperactivity of itch-activating spinal pathways, dysfunction of spinal inhibitory circuits, and attenuation of descending supraspinal inhibitory pathways. In the brain, neural sensitization manifests as structural and functional changes to itch-associated brain areas and networks. Currently, we have a diverse array of neuroimmune-modulating therapies targeting itch neural sensitization mechanisms to help with providing relief to patients with chronic itch. Itch research is a dynamic and continually evolving field, and as we grow in our understanding of chronic itch mechanisms, so will our therapeutic toolbox. Further studies exploring the peripheral and central neural sensitization mechanisms in the context of chronic itch are needed.

11.
J Clin Med ; 12(15)2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37568427

RESUMO

BACKGROUND: Black and geriatric patients were reported in small scale studies to have more intense chronic pruritus (CP). Studies comparing itch across geriatric racial groups are lacking. OBJECTIVES: To compare the prevalence of CP in Black and White inpatients ≥ 65 years old as well as the top primary diagnoses of these populations. METHODS: We used data from the National Inpatient Sample from 2016-2019 to analyze CP prevalence and ICD10-CM to identify diseases. The top five primary diagnoses were calculated for a subpopulation with CP. Sample characteristics were described, and the data was pooled and analyzed using IBM SPSS® Complex Sample modules. RESULTS: Among hospitalized Black inpatients ≥ 65 years old, the prevalence of CP was 0.26% while in the White cohort it was 0.22%. The top five primary diagnoses in the Black population with itch were sepsis (4.2%); hypertensive heart and chronic kidney disease (CKD) with heart failure (HF) and stage 1-4 CKD, or unspecified CKD (4.1%); acute kidney failure (4.0%); hypertensive heart and CKD with HF with stage 5 CKD, or end-stage renal disease (2.1%); and hypertensive heart disease with HF (1.7%). The top five primary diagnoses in the White population were sepsis (4.25%); acute kidney failure (3.0%); hypertensive heart and CKD with HF and stage 1-4 CKD, or unspecified CKD (2.5%); cellulitis of left lower limb (1.9%); and unilateral primary osteoarthritis, right knee (1.9%). CONCLUSIONS: Geriatric hospitalized Black patients demonstrated a higher prevalence of chronic itch compared with the White cohort, which may be related to the higher prevalence of chronic kidney disease in different stages of severity in this population.

12.
J Clin Med ; 12(14)2023 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-37510789

RESUMO

Atopic dermatitis (AD) affects diverse ethnic groups with significant disparities in prevalence, disease progression, clinical outcomes, and access to care. There are limited data on AD in the Arabic population of the Middle East, yet there is a substantial economic and psychosocial burden of AD in this region with a large unmet need with regards to disease management that is critical to address. There is a trend of increasing prevalence of AD in the Arab Middle East; however, due to the large environmental, socioeconomic, and sociocultural heterogeneity of this region, prevalence varies greatly across and within countries. Similarly, clinical differences in disease presentations exist across the region, although data are limited. In this review, we will present clinical phenotypes of AD common in different regions of the Arab Middle East, and data on prevalence, genetic variations, and challenges of treatment. Further studies exploring molecular biomarkers, genetic polymorphisms, immune factors, and the microbiome of patients in the region will help to elucidate the mechanism behind ethnic differences in AD in this population as well as to understand susceptibilities and treatment response.

13.
J Fungi (Basel) ; 9(7)2023 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-37504757

RESUMO

Invasive fungal infections, notably candidemia, have been associated with COVID-19. The epidemiology of candidemia has significantly changed during the COVID-19 pandemic. We aim to identify the microbiological profile, resistance rates, and outcomes of COVID-19-associated candidemia (CAC) compared to patients with candidemia not associated with COVID-19. We retrospectively collected data on patients with candidemia admitted to the American University of Beirut Medical Center between 2004 and 2022. We compared the epidemiology of candidemia during and prior to the COVID-19 pandemic. Additionally, we compared the outcomes of critically ill patients with CAC to those with candidemia without COVID-19 from March 2020 till March 2022. Among 245 candidemia episodes, 156 occurred prior to the pandemic and 89 during the pandemic. Of the latter, 39 (43.8%) were CAC, most of which (82%) were reported from intensive care units (ICU). Non-albicans Candida (NAC) spp. were predominant throughout the study period (67.7%). Candida auris infection was the most common cause of NAC spp. in CAC. C. glabrata had decreased susceptibility rates to fluconazole and caspofungin during the pandemic period (46.1% and 38.4%, respectively). The mortality rate in the overall ICU population during the pandemic was 76.6%, much higher than the previously reported candidemia mortality rate observed in studies involving ICU patients. There was no significant difference in 30-day mortality between CAC and non-CAC (75.0% vs. 78.1%; p = 0.76). Performing ophthalmic examination (p = 0.002), CVC removal during the 48 h following the candidemia (p = 0.008) and speciation (p = 0.028) were significantly associated with a lower case-fatality rate. The epidemiology of candidemia has been significantly affected by the COVID-19 pandemic at our center. Rigorous infection control measures and proper antifungal stewardship are essential to combat highly resistant species such as C. auris.

14.
Dermatol Ther (Heidelb) ; 13(8): 1647-1660, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37386330

RESUMO

Chronic spontaneous urticaria (CSU) is a condition in which wheals, angioedema, and pruritus occur spontaneously and recurrently for at least 6 weeks. The etiology of this disease is partially dependent on production of autoantibodies that activate and recruit inflammatory cells. Although the wheals can resolve within 24 h, symptoms have a significant detrimental impact on the quality of life of these patients. Standard therapy for CSU includes second-generation antihistamines and omalizumab. However, many patients tend to be refractory to these therapies. Available treatments such as cyclosporine, dapsone, dupilumab, and tumor necrosis factor alpha (TNFa) inhibitors have been used with success in some cases. Furthermore, various biologics and other novel drugs have emerged as potential treatments for this condition, and many more are currently under investigation in randomized clinical trials.

15.
Expert Rev Anticancer Ther ; 23(4): 369-373, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36951118

RESUMO

INTRODUCTION: Although PSA screening has been rationalized, prostate cancer continues to have the highest incidence rate in 2021, and alone accounts for 26% of cancer diagnoses in men. A thorough review of the medical literature highlights a vast array of approved and investigational treatments for prostate cancer. Thus, selecting the best treatment option for the appropriate patient at the right time is crucial. Hence, biomarkers help in defining optimal patient stratification, revealing potential processes through which a drug might exert its impact and aid in the tailoring of treatments for efficient personalized medicine. AREAS COVERED: This article is a pragmatic review of novel prostate cancer therapies that can help guide clinicians in tackling prostate cancer with the latest treatments. EXPERT OPINION: Local radiotherapy has proven to be a game changer for low burden, de novo metastatic prostate cancer. Androgen deprivation therapy continues to be the ultimate treatment. Delaying resistance to these agents will undoubtedly be a breakthrough in the treatment of prostate cancer. When it comes to metastatic castrate-resistant disease, treatment options become narrower. PARP inhibitors and N-terminal domain inhibitors offer new hope and have a synergistic effect, with immunotherapy adding promising agents to the therapeutic arsenal.


Assuntos
Neoplasias de Próstata Resistentes à Castração , Neoplasias da Próstata , Masculino , Humanos , Neoplasias da Próstata/patologia , Neoplasias de Próstata Resistentes à Castração/patologia , Antagonistas de Androgênios/farmacologia , Antagonistas de Androgênios/uso terapêutico , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico
16.
Chest ; 162(6): e301-e305, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36494129

RESUMO

CASE PRESENTATION: A 59-year-old woman sought treatment for 5 weeks of progressive exercise intolerance. At the time of presentation, dyspnea limited her ability to speak in complete sentences. She also reported new orthopnea. Her respiratory symptoms improved with rest and while standing. She endorsed associated intermittent low-grade fevers, cough productive of scant clear sputum, lower extremity swelling, bloating, weight loss, and reduced appetite. She had undergone two recent admissions with similar symptoms to other hospitals, during which she was treated empirically for community-acquired pneumonia and discharged after workups for infectious disease were unrevealing. She had a history notable for systemic lupus erythematosus (SLE) diagnosed in 2006, complicated by lupus nephritis in 2009. Most recently, her SLE had been quiescent while she was taking hydroxychloroquine (400 mg daily) and mycophenolate mofetil (MMF; 1 g twice daily). She reported baseline mild dyspnea with exertion since she received a diagnosis of SLE, but her symptoms had not previously affected her activities of daily living. The patient did not smoke, drink alcohol, or use recreational drugs, and her family history was unremarkable.


Assuntos
Pneumopatias , Lúpus Eritematoso Sistêmico , Nefrite Lúpica , Humanos , Feminino , Pessoa de Meia-Idade , Atividades Cotidianas , Ácido Micofenólico/uso terapêutico , Nefrite Lúpica/complicações , Dispneia/diagnóstico , Dispneia/etiologia , Pneumopatias/complicações , Lúpus Eritematoso Sistêmico/complicações , Lúpus Eritematoso Sistêmico/diagnóstico , Febre/tratamento farmacológico
17.
Sci Rep ; 12(1): 17170, 2022 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-36229498

RESUMO

According to research, exposing a person to a magnetic field enhances blood flow and minimizes their risk of suffering a heart attack. Ferrohydrodynamics is the study of fluid motion mechanics that is affected by strong magnetic polarisation forces (FHD). Ferrofluids may transmit heat in a variety of ways by using magnetic fluids. This behaviour is demonstrated by liquid-cooled speakers, which utilise less ferrofluid to prevent heat from reaching the speaker coil. This modification boosts the coil's ability to expand, which enables the loudspeaker to create high-fidelity sound. It is investigated how the fluid dynamics of spinning, squeezing plates are affected by thermosolutal convection and a magnetic field dependent (MFD) viscosity. Standard differential equations are used to represent the equations of the modified form of Navier Stokes, Maxwell's, and thermosolutal convection. The magnetic field, modified velocity field equations, and thermosolutal convection equations all yield suitable answers. Additionally computed and thoroughly detailed are the MHD torque and fluid pressure that are imparted to the top plate. To create a technique with quick and certain convergence, the resulting equations for uniform plates are solved using the Homotopy Analysis Method (HAM) with appropriate starting estimates and auxiliary parameters. The validity and reliability of the HAM outcomes are shown by comparing the HAM solutions with the BVP4c numerical solver programme. It has been found that a magnetic Reynolds number lowers the temperature of the fluid as well as the tangential and axial components of the velocity field. Additionally, when the fluid's MFD viscosity rises, the axial and azimuthal components of the magnetic field behave in opposition to one another. This study has applications in the development of new aircraft take-off gear, magnetorheological airbags for automobiles, heating and cooling systems, bio-prosthetics, and biosensor systems.


Assuntos
Convecção , Hidrodinâmica , Coloides , Humanos , Campos Magnéticos , Modelos Teóricos , Reprodutibilidade dos Testes , Viscosidade
18.
Sci Rep ; 12(1): 17364, 2022 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-36253393

RESUMO

Gold nanoparticles are commonly used as a tracer in laboratories. They are biocompatible and can transport heat energy to tumor cells via a variety of clinical techniques. As cancer cells are tiny, properly sized nanoparticles were introduced into the circulation for invasion. As a result, gold nanoparticles are highly effective. Therefore, the current research investigates the magnetohydrodynamic free convection flow of Casson nanofluid in an inclined channel. The blood is considered as a base fluid, and gold nanoparticles are assumed to be uniformly dispersed in it. The above flow regime is formulated in terms of partial differential equations. The system of derived equations with imposed boundary conditions is non-dimensionalized using appropriate dimensionless variables. Fourier's and Fick's laws are used to fractionalize the classical dimensionless model. The Laplace and Fourier sine transformations with a new transformation are used for the closed-form solutions of the considered problem. Finally, the results are expressed in terms of a specific function known as the Mittag-Leffler function. Various figures and tables present the effect of various physical parameters on the achieved results. Graphical results conclude that the fractional Casson fluid model described a more realistic aspect of the fluid velocity profile, temperature, and concentration profile than the classical Casson fluid model. The heat transfer rate and Sherwood number are calculated and presented in tabular form. It is worth noting that increasing the volume percentage of gold nanoparticles from 0 to 0.04 percent resulted in an increase of up to 3.825% in the heat transfer rate.


Assuntos
Ouro , Nanopartículas Metálicas , Convecção , Temperatura Alta , Temperatura
19.
Sci Rep ; 12(1): 9148, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35650256

RESUMO

The ongoing research aims to examine the mass and heat transmission phenomena of squeezing flow between two concentric cylinders under the effect of heat sources and magnetic fields. The impacts of the Lorentz force on the behavior of the liquid flow are elucidated via a magnetic field incorporated in the momentum equation. Furthermore, within concentric cylinders, the expression [Formula: see text] has been employed as a source/sink. The proposed model of PDEs formulates the physical phenomena of time-dependent incompressible two-dimensional squeezing flow via modified Navier-Stokes equation, energy equation, and mass transfer equation, and variable magnetic field. The proposed model involved a highly nonlinear system of PDEs, which has been reduced into a system of ODEs via Lie group of similarity transformation and subsequently solved numerically in MATLAB by Parametric Continuation Method. The direct impact of the squeezing parameter on the profile of temperature and concentration has been observed. The results shown that an increment in the heat source indicates a decline in the liquid temperature profile, that an increment in the heat source indicates a decline in the liquid temperature profile. An increment in the heat source indicates a decline in the liquid temperature prof. At the same time, an inverse relationship is observed for the concentration profile. Therefore, we have witnessed a significant increase in the velocity profiles of the flow, mainly as a result of the heat absorption coefficient. In addition, the declining effect of the Soret number on the concentration profile is noticed. It has been found that it enhanced the entropy generation rate for Pr, [Formula: see text], and Ec, while an opposite impact has been noticed at the Bejan number. The numerical outcomes of the proposed model that explain fluid flow characteristics and fluid flow characteristics are quantitatively elucidated by tables and displayed graphically. The comparison of two numerical results in the cases are found to be in good agreement, as shown in Tables.

20.
Nanomaterials (Basel) ; 12(11)2022 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-35683647

RESUMO

Lately, a new class of nanofluids, namely hybrid nanofluids, has been introduced that performs much better compared with the nanofluids when a healthier heat transfer rate is the objective of the study. Heading in the same direction, the present investigation accentuates the unsteady hybrid nanofluid flow involving CuO, Al2O3/C2H6O2 achieved by an oscillating disk immersed in the porous media. In a study of the homogeneous and heterogeneous reactions, the surface catalyzed reaction was also considered to minimize the reaction time. The shape factors of the nanoparticles were also taken into account, as these play a vital role in assessing the thermal conductivity and heat transfer rate of the system. The assumed model is presented mathematically in the form of partial differential equations. The system is transformed by invoking special similarity transformations. The Keller Box scheme was used to obtain numerical and graphical results. It is inferred that the blade-shaped nanoparticles have the best thermal conductivity that boosts the heat transfer efficiency. The oscillation and surface-catalyzed chemical reactions have opposite impacts on the concentration profile. This analysis also includes a comparison of the proposed model with a published result in a limiting case to check the authenticity of the presented model.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...