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1.
Trop Biomed ; 40(2): 174-182, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37650404

RESUMO

The present study was conducted to investigate the antimicrobial potential of essential oils of Curcuma longa and Syzygium aromaticum against multidrug-resistant pathogenic bacteria. Four identified bacterial isolates including Methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii were selected and their antibiotic sensitivity was checked by disc diffusion assay. C. longa and S. aromaticum were subjected to steam distillation to obtain their essential oils. The crude essential oils were fractioned by employing column chromatography. Crude essential oils and their fractions were evaluated for their antibacterial activity by agar well diffusion assay and minimum inhibitory concentrations were calculated. All the selected bacterial isolates showed resistance to three or more than three antibiotic groups and were declared as multidrugresistant (MDRs). Crude essential oils of C. longa and S. aromaticum exhibited antimicrobial activity against all selected isolates but S. aromaticum activity was better than the C. longa with a maximum 19.3±1.50 mm zone of inhibition against A. baumannii at 1.04 µL/mL MIC. GC/MS analysis revealed the abundance of components including eugenol, eugenyl acetate, b- caryophyllene, and a- Humulene in both crude oil and fractions of S. aromaticum. While the main components of C. longa essential oil were Ar-tumerone, a-tumerone, b- Tumerone, I-Phellandrene, a-zingibirene, b- sesquiphellandrene, and p- Cymene. This study highlights that plant-based essential oils could be a promising alternative to antibiotics for which pathogens have developed resistance. C. longa and S. aromaticum carry compounds that have antimicrobial potential against multiple drug-resistant bacteria including MRSA. E. coli, K. pneumoniae and A. baumannii.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Óleos Voláteis , Syzygium , Óleos Voláteis/farmacologia , Curcuma , Escherichia coli , Óleos de Plantas , Antibacterianos/farmacologia , Bactérias
2.
Micromachines (Basel) ; 14(2)2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36838011

RESUMO

Micro-electro-mechanical systems (MEMS) have enabled new techniques for the miniaturization of sensors suitable for Structural Health Monitoring (SHM) applications. In this study, MEMS-based sensors, specifically Piezoelectric Micromachined Ultrasonic Transducers (PMUT), are used to evaluate and monitor the pre-tensioning of a bolted joint structural system. For bolted joints to function properly, it is essential to maintain a suitable level of pre-tensioning. In this work, an array of PMUTs attached to the head and to the end of a bolt, serve as transmitter and receiver, respectively, in a pitch-catch Ultrasonic Testing (UT) scenario. The primary objective is to detect the Change in Time of Flight (CTOF) of the acoustic wave generated by the PMUT array and propagating along the bolt's axis between a non-loaded bolt and a bolt in service. To model the pre-tensioning of bolted joints and the transmission of the acoustic wave to and from a group of PMUTs through the bolt, a set of numerical models is created. The CTOF is found to be linearly related to the amount of pre-tensioning. The numerical model is validated through comparisons with the results of a preliminary experimental campaign.

3.
Micromachines (Basel) ; 13(6)2022 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-35744576

RESUMO

This paper presents a numerical reduced-order modeling (ROM) approach for complex multi-layered arrays of piezoelectric micromachined ultrasonic transducers (PMUTs). The numerical modeling technique adopted to generate an array of PMUTs consisting of a considerable number of transducers allows for a large reduction in computational cost without reducing accuracy. The modeling idea is based on coupling shell elements applied to the PMUT structural layers with 3D-solid elements applied to the piezoelectric layer. A set of eigenfrequency and frequency domain analyses are presented considering a single ROM of a PMUT performing in different ambients and the performing central frequencies are obtained for every considered scenario. A unique arrangement of 228 PMUTs is presented and tested for its ability to transmit and receive acoustic waves. The operating frequency band of the array and the level of interference and cross-talk among different PMUTs in the near field are estimated. Finally, the results from a preliminary experimental test performed to analyze the acoustic abilities of an 8 × 8 array of PMUTs are presented. A corresponding numerical model is created and the obtained results matched the experimental data, leading to a validation of the modeling technique proposed in this work.

4.
Pain Rep ; 4(6): e743, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31984287

RESUMO

This study investigated the clinical characteristics and somatosensory profiles of patients suffering from leprosy in Mumbai, India. A cross-sectional deep profiling study was conducted in 86 patients with leprosy (with and without pain) using an extensive battery of phenotyping measures including structured clinical examination, psychological state (General Health Questionnaire [GHQ-12]), and a quality-of-life condition-specific instrument (Brief Pain Inventory-short form). Quantitative sensory testing was performed according to the protocol of the German Research Network on Neuropathic Pain (DFNS) to assess the somatosensory profiles in the ulnar nerve innervation territory of all participants (dorsum of the hand). Reference data from 50 healthy Indian subjects were within the range of published DFNS values. Somatosensory profiles in leprosy patients with clinically or electroneurographically diagnosed neuropathy (with and without pain) revealed a profile of sensory loss to thermal and tactile stimuli combined with preservation of vibration and deep pressure detection. Sensory gain phenomena were not generally observed in patients with leprosy. In the group of subclinical neuropathy, a high degree of impaired thermal sensation was found, which could be clinically deployed to enhance identification of leprosy neuropathy at an early stage. Quantitative sensory testing can effectively document leprosy-associated neuropathy but does not distinguish between patients with or without pain. Patients with leprosy and neuropathic pain reported a poor quality of life and less psychological well-being compared with the pain-free patients with leprosy neuropathy.

5.
Pol J Vet Sci ; 19(3): 545-551, 2016 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-27760040

RESUMO

Aflatoxins are secondary metabolites produced by Aspergillus spp. which are injurious to animals and humans The aim of this study was to determine the effects of aflatoxin B1 (AFB1) on Average Daily Feed Intake (ADFI), Average Daily Weight Gain (ADWG), haematological and serum biochemical responses of Bovine Calves and to determine the comparative efficacy of two different liver tonics against AFB1. Twenty seven calves were selected from herd and divided into 3 groups. All calves were fed with 1.0 mg/kg AFB1 for a period of 10 days. After that they were fed with liver tonics: Silymarin fed at a rate of 600 mg/kg and Choline chloride 500 mg/kg for 7 days. The results indicate that the ADFI and ADWG of AFB1 treated calves decreased significantly. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN) and creatinine significantly increased due to AFB1. In haematology the total erythrocyte count (TEC), total leukocyte count (TLC), haemoglobin concentration (HGB), haematocrit levels (HCT), mean corpuscular haemoglobin (MCH), mean corpuscular volume (MCV) and mean corpuscular haemoglobin concentration (MCHC), lymphocyte %, neutrophil % and monocyte % significantly decreased in AFB1 treated calves after 10 days of feeding. Both liver tonics significantly (p<0.05) improved all the parameters, including ADFI, ADWG, hematologial and serum biochemical test. However, Silymarin comparatively more efficiently ameliorate the effects induced by AFB1 than choline chloride.


Assuntos
Aflatoxina B1/toxicidade , Doenças dos Bovinos/induzido quimicamente , Doença Hepática Induzida por Substâncias e Drogas/veterinária , Colina/farmacologia , Silimarina/farmacologia , Animais , Bovinos , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Contaminação de Alimentos
7.
Pain ; 153(8): 1620-1624, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22727538

RESUMO

Pain can be a significant problem for treated leprosy patients. It can be nociceptive due to tissue inflammation occurring during episodes of immune mediated reactions, or neuropathic due to leprosy affecting the somatosensory system. There are sparse epidemiological data on the prevalence and impact of neuropathic pain in treated leprosy patients. Tools for assessing neuropathic pain have not been validated in leprosy. We have examined nature of pain in a cross-sectional study to determine the prevalence of neuropathic pain (NP) in 80 recently treated leprosy patients in Ethiopia. Pain and depression were evaluated using the General Health Questionnaire (GHQ-12) and the Brief Pain Inventory (BPI) questionnaire. The Douleur Neuropathique en 4 Questions (DN4) and the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) were used as screening tools for NP. Pain of any type was experienced by 60% of the patients. Pure nociceptive pain was experienced by 43%, pure NP by 11%, and mixed pain by 6%. Of the 14 patients who had NP either alone or in combination with nociceptive pain, 12 had high GHQ-12 scores, indicating possible depression. The DN4 had sensitivity and specificity of 100% and 45%, whereas the LANSS had 85% and 42%, respectively. This is the first study to differentiate nociceptive from NP in leprosy patients. The prevalence of NP is high in recently treated Ethiopian leprosy patients. We have validated the use of DN4 in leprosy and it is easier to use than LANSS. Depression is a common co-morbidity in patients with NP. The high prevalence and morbidity of NP in treated leprosy patients warrant clinical trials to assess the efficacy of pain therapies for leprosy-associated NP.


Assuntos
Hanseníase/diagnóstico , Hanseníase/epidemiologia , Neuralgia/diagnóstico , Neuralgia/epidemiologia , Medição da Dor/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Causalidade , Comorbidade , Estudos Transversais , Etiópia/epidemiologia , Feminino , Humanos , Hanseníase/terapia , Masculino , Pessoa de Meia-Idade , Medição da Dor/estatística & dados numéricos , Prevalência , Reprodutibilidade dos Testes , Fatores de Risco , Sensibilidade e Especificidade , Adulto Jovem
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