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1.
Calcif Tissue Int ; 114(5): 513-523, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38656326

RESUMO

Previously, we demonstrated that prebiotics may provide a complementary strategy for increasing calcium (Ca) absorption in adolescents which may improve long-term bone health. However, not all children responded to prebiotic intervention. We determine if certain baseline characteristics of gut microbiome composition predict prebiotic responsiveness. In this secondary analysis, we compared differences in relative microbiota taxa abundance between responders (greater than or equal to 3% increase in Ca absorption) and non-responders (less than 3% increase). Dual stable isotope methodologies were used to assess fractional Ca absorption at the end of crossover treatments with placebo, 10, and 20 g/day of soluble corn fiber (SCF). Microbial DNA was obtained from stool samples collected before and after each intervention. Sequencing of the 16S rRNA gene was used to taxonomically characterize the gut microbiome. Machine learning techniques were used to build a predictive model for identifying responders based on baseline relative taxa abundances. Model output was used to infer which features contributed most to prediction accuracy. We identified 19 microbial features out of the 221 observed that predicted responsiveness with 96.0% average accuracy. The results suggest a simplified prescreening can be performed to determine if a subject's bone health may benefit from a prebiotic. Additionally, the findings provide insight and prompt further investigation into the metabolic and genetic underpinnings affecting calcium absorption during pubertal bone development.


Assuntos
Cálcio , Microbioma Gastrointestinal , Prebióticos , Adolescente , Criança , Feminino , Humanos , Masculino , Cálcio/metabolismo , Estudos Cross-Over , Fezes/microbiologia , Microbioma Gastrointestinal/fisiologia , Microbioma Gastrointestinal/genética , Projetos Piloto , Prebióticos/administração & dosagem
2.
Artif Organs ; 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39078122

RESUMO

BACKGROUND: The microfluidic-based Glomerulus-on-Chips (GoC) are mostly cell based, that is, 3D cell culture techniques are used to culture glomerular cells in order to mimic glomerular ultrafiltration. These chips require high maintenance to keep cell viability intact. There have been some approaches to build non-cell-based GoCs but many of these approaches have the drawback of membrane fouling. This article presents a structural design and simulation study of a dialysate free microfluidic channel for replicating the function of the human glomerular filtration barrier. The key advancement of the current work is addressing the fouling issue by combining a pre-filter to eliminate cellular components and performing filtration on the blood plasma. METHODS: The Laminar Flow Mixture Model in COMSOL Multiphysics 5.6 has been utilized to simulate the behavior of blood flow in the microchannels. The geometrical effect of microchannels on the separation of the filtrate was investigated. The velocity at the inlet of the microchannel and pore size of the filtration membrane are varied to see the change in outflow and filtration fraction. RESULTS: The efficiency of the device is calculated in terms of the filtration fraction (FF%) formed. Simulation results show that the filtrate obtained is ~20% of the plasma flow rate in the channel, which resembles the glomerular filtration fraction. CONCLUSION: Given that it is not dependent on the functionality of grown cells, the proposed device is anticipated to have a longer lifespan due to its non-cell-based design. The device's cost can be reduced by avoiding cell cultivation inside of it. It can be integrated as a glomerular functional unit with other units of kidney model to build a fully developed artificial kidney.

3.
Int Endod J ; 55(11): 1190-1201, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35976108

RESUMO

AIMS: To evaluate the complexity of root canal treatments accepted for treatment by postgraduate training grades at Cardiff University Dental Hospital (CUDH) using the English Commissioning Standard for Restorative Dentistry (ECS) in comparison with the American Association of Endodontists case complexity form (AAE) and the Restorative Index of Treatment Need (RIOTN). METHODOLOGY: Two hundred case records were evaluated using the AAE, RIOTN and ECS scoring systems. Each case received a score from minimal to high complexity (1-3). Examiners were calibrated and inter-examiner reliability calculated using the percentage agreement. Frequency of scores were then compared. RESULTS: Most cases were at level 3 and assessment varied amongst the criteria used (AAE: 99.5%, RIOTN: 65.5% and ECS: 55.5%). The AAE factor 'endodontic treatment history' was largely responsible for differing scores when compared with the RIOTN (78%) and ECS (64%). The RIOTN factor regarding post treatment disease ('endodontic retreatment') was responsible for increased complexity compared with ECS in most cases (74%). The ECS factor 'quality of root filling' was the most common reason (85%) for an increase in complexity compared with RIOTN. CONCLUSIONS: Within the limitations of this service evaluation, it was possible to conclude that a high proportion of cases treated by training grades at CUDH were of a high complexity level (level 3) using the three guidelines (ECS, AAE and RIOTN). These cases were appropriate for postgraduate training under various levels of supervision and substantiated by the findings reported here. The factors responsible for a large part of difference in allocation of scores amongst the systems were 'endodontic treatment history', 'root canal retreatment' and 'quality of root filling'.


Assuntos
Endodontia , Cavidade Pulpar , Endodontia/educação , Humanos , Reprodutibilidade dos Testes , Tratamento do Canal Radicular , Atenção Secundária à Saúde
4.
Sensors (Basel) ; 21(5)2021 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-33806426

RESUMO

Microwave radar technology is very attractive for ubiquitous short-range health monitoring due to its non-contact, see-through, privacy-preserving and safe features compared to the competing remote technologies such as optics. The possibility of radar-based approaches for breathing and cardiac sensing was demonstrated a few decades ago. However, investigation regarding the robustness of radar-based vital-sign monitoring (VSM) is not available in the current radar literature. In this paper, we aim to close this gap by presenting an extensive experimental study of vital-sign radar approach. We consider diversity in test subjects, fitness levels, poses/postures, and, more importantly, random body movement (RBM) in the study. We discuss some new insights that lead to robust radar heart-rate (HR) measurements. A novel active motion cancellation signal-processing technique is introduced, exploiting dual ultra-wideband (UWB) radar system for motion-tolerant HR measurements. Additionally, we propose a spectral pruning routine to enhance HR estimation performance. We validate the proposed method theoretically and experimentally. Totally, we record and analyze about 3500 seconds of radar measurements from multiple human subjects.


Assuntos
Radar , Processamento de Sinais Assistido por Computador , Algoritmos , Frequência Cardíaca , Humanos , Monitorização Fisiológica , Movimento (Física) , Respiração
5.
Microb Cell Fact ; 19(1): 77, 2020 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-32209105

RESUMO

BACKGROUND: Microbes are rich sources of enzymes and esterases are one of the most important classes of enzymes because of their potential for application in the field of food, agriculture, pharmaceuticals and bioremediation. Due to limitations in their cultivation, only a small fraction of the complex microbial communities can be cultured from natural habitats. Thus to explore the catalytic potential of uncultured organisms, the metagenomic approach has turned out to be an effective alternative method for direct mining of enzymes of interest. Based on activity-based screening method, an esterase-positive clone was obtained from metagenomic libraries. RESULTS: Functional screening of a soil metagenomic fosmid library, followed by transposon mutagenesis led to the identification of a 1179 bp esterase gene, estM2, that encodes a 392 amino acids long protein (EstM2) with a translated molecular weight of 43.12 kDa. Overproduction, purification and biochemical characterization of the recombinant protein demonstrated carboxylesterase activity towards short-chain fatty acyl esters with optimal activity for p-nitrophenyl butyrate at pH 8.0 and 37 °C. Amino acid sequence analysis and subsequent phylogenetic analysis suggested that EstM2 belongs to the family VIII esterases that bear modest similarities to class C ß-lactamases. EstM2 possessed the conserved S-x-x-K motif of class C ß-lactamases but did not exhibit ß-lactamase activity. Guided by molecular docking analysis, EstM2 was shown to hydrolyze a wide range of di- and monoesters of alkyl-, aryl- and benzyl-substituted phthalates. Thus, EstM2 displays an atypical hydrolytic potential of biotechnological significance within family VIII esterases. CONCLUSIONS: This study has led to the discovery of a new member of family VIII esterases. To the best of our knowledge, this is the first phthalate hydrolase (EstM2), isolated from a soil metagenomic library that belongs to a family possessing ß-lactamase like catalytic triad. Based on its catalytic potential towards hydrolysis of both phthalate diesters and phthalate monoesters, this enzyme may find use to counter the growing pollution caused by phthalate-based plasticizers in diverse geological environment and in other aspects of biotechnological applications.


Assuntos
Esterases/genética , Metagenoma/genética , Ácidos Ftálicos/metabolismo
6.
Artif Organs ; 44(8): E369-E381, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32219877

RESUMO

Human kidneys tend to be affected adversely and fail to function more often than any other organ in the body because of diet, heredity, and lifestyle of a person. Dialysis is the technique presently in use for replacing the failed kidney function but it is packed with painfulness, bulkiness, and is costly also. There is a growing need for development of an artificial kidney that eradicates the problems associated with dialysis. This article proposes a structure that mimics the most important aspect of the human kidney: the size-dependent reabsorption of endothelial cells in the proximal convoluted tubule (PCT). The proposed structure consists of transporting channels connecting blood tubules surrounded on both sides of a main tubule. Geometries of the channels are analyzed for optimum flow by varying angles with respect to the main tubule. The analytical formulae have been developed by considering proper boundary conditions governing the flow in the structure, which makes the model as robust, concise, and realistic as the actual PCT. The mathematical model is validated against the benchmark FEM tool COMSOL Multiphysics and the results seem to be satisfactory. This article concludes, that slant channels possess a considerably higher average flow velocity of 5.39 × 10-5  m/s (≈52% reabsorption rate) than straight channels with 4.77 × 10-5  m/s (≈46% reabsorption rate) which is closer to the actual PCT reabsorption rate of 60%. The proposed model is first of its kind in nature among the reported works which creates and exhibits simulation environment of PCT reabsorption function supported by mathematical formulation and also can be useful to study and develop artificial kidney in near future.


Assuntos
Rins Artificiais , Humanos , Túbulos Renais Proximais/fisiologia , Microfluídica , Modelos Anatômicos , Modelos Biológicos , Desenho de Prótese
7.
Sensors (Basel) ; 20(21)2020 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-33120869

RESUMO

Multiplexed deep neural networks (DNN) have engendered high-performance predictive models gaining popularity for decoding brain waves, extensively collected in the form of electroencephalogram (EEG) signals. In this paper, to the best of our knowledge, we introduce a first-ever DNN-based generalized approach to estimate reaction time (RT) using the periodogram representation of single-trial EEG in a visual stimulus-response experiment with 48 participants. We have designed a Fully Connected Neural Network (FCNN) and a Convolutional Neural Network (CNN) to predict and classify RTs for each trial. Though deep neural networks are widely known for classification applications, cascading FCNN/CNN with the Random Forest model, we designed a robust regression-based estimator to predict RT. With the FCNN model, the accuracies obtained for binary and 3-class classification were 93% and 76%, respectively, which further improved with the use of CNN (94% and 78%, respectively). The regression-based approach predicted RTs with correlation coefficients (CC) of 0.78 and 0.80 for FCNN and CNN, respectively. Investigating further, we found that the left central as well as parietal and occipital lobes were crucial for predicting RT, with significant activities in the theta and alpha frequency bands.


Assuntos
Algoritmos , Eletroencefalografia , Redes Neurais de Computação , Tempo de Reação , Humanos
8.
Sensors (Basel) ; 18(11)2018 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-30424512

RESUMO

The purpose of this study was to classify, and model various physical activities performed by a diverse group of participants in a supervised lab-based protocol and utilize the model to identify physical activity in a free-living setting. Wrist-worn accelerometer data were collected from ( N = 152 ) adult participants; age 18⁻64 years, and processed the data to identify and model unique physical activities performed by the participants in controlled settings. The Gaussian mixture model (GMM) and the hidden Markov model (HMM) algorithms were used to model the physical activities with time and frequency-based accelerometer features. An overall model accuracy of 92.7% and 94.7% were achieved to classify 24 physical activities using GMM and HMM, respectively. The most accurate model was then used to identify physical activities performed by 20 participants, each recorded for two free-living sessions of approximately six hours each. The free-living activity intensities were estimated with 80% accuracy and showed the dominance of stationary and light intensity activities in 36 out of 40 recorded sessions. This work proposes a novel activity recognition process to identify unsupervised free-living activities using lab-based classification models. In summary, this study contributes to the use of wearable sensors to identify physical activities and estimate energy expenditure in free-living settings.


Assuntos
Acelerometria , Monitorização Fisiológica , Dispositivos Eletrônicos Vestíveis , Adolescente , Adulto , Exercício Físico , Feminino , Humanos , Aprendizado de Máquina , Masculino , Cadeias de Markov , Pessoa de Meia-Idade , Adulto Jovem
9.
J Bacteriol ; 198(12): 1755-1763, 2016 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-27068590

RESUMO

UNLABELLED: The gene encoding a nonoxidative decarboxylase capable of catalyzing the transformation of 2-hydroxy-1-naphthoic acid (2H1NA) to 2-naphthol was identified, recombinantly expressed, and purified to homogeneity. The putative gene sequence of the decarboxylase (hndA) encodes a 316-amino-acid protein (HndA) with a predicted molecular mass of 34 kDa. HndA exhibited high identity with uncharacterized amidohydrolase 2 proteins of various Burkholderia species, whereas it showed a modest 27% identity with γ-resorcylate decarboxylase, a well-characterized nonoxidative decarboxylase belonging to the amidohydrolase superfamily. Biochemically characterized HndA demonstrated strict substrate specificity toward 2H1NA, whereas inhibition studies with HndA indicated the presence of zinc as the transition metal center, as confirmed by atomic absorption spectroscopy. A three-dimensional structural model of HndA, followed by docking analysis, identified the conserved metal-coordinating and substrate-binding residues, while their importance in catalysis was validated by site-directed mutagenesis. IMPORTANCE: Microbial nonoxidative decarboxylases play a crucial role in the metabolism of a large array of carboxy aromatic chemicals released into the environment from a variety of natural and anthropogenic sources. Among these, hydroxynaphthoic acids are usually encountered as pathway intermediates in the bacterial degradation of polycyclic aromatic hydrocarbons. The present study reveals biochemical and molecular characterization of a 2-hydroxy-1-naphthoic acid nonoxidative decarboxylase involved in an alternative metabolic pathway which can be classified as a member of the small repertoire of nonoxidative decarboxylases belonging to the amidohydrolase 2 family of proteins. The strict substrate specificity and sequence uniqueness make it a novel member of the metallo-dependent hydrolase superfamily.


Assuntos
Amidoidrolases/metabolismo , Burkholderia/enzimologia , Carboxiliases/metabolismo , Ácidos Carboxílicos/metabolismo , Naftalenos/metabolismo , Amidoidrolases/química , Amidoidrolases/genética , Sequência de Aminoácidos , Bactérias/química , Bactérias/classificação , Bactérias/enzimologia , Bactérias/genética , Burkholderia/química , Burkholderia/genética , Burkholderia/metabolismo , Carboxiliases/química , Carboxiliases/genética , Cinética , Dados de Sequência Molecular , Família Multigênica , Filogenia , Alinhamento de Sequência , Especificidade por Substrato
10.
J Dent ; 144: 104928, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38484867

RESUMO

OBJECTIVES: Synthesise evidence on post-endodontic pain (PEP) in adult teeth undergoing primary root canal treatment with the adjunctive use of laser-activated irrigation (LAI) as compared with conventional needle irrigation (CNI) during the first post-operative week. DATA: An electronic search was performed; no language constraints or restriction on the year of publication were applied. SOURCES: Medline, Scopus, Cochrane and PubMed on 04 June 2023 STUDY SELECTION: Randomised clinical trials (RaCTs) that evaluated PEP after LAI of endodontic irrgants were included. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used. PEP was analysed at various time intervals until 1 week after treatment, related to the type of LAI used and the need for analgesia. REULTS: Of the 793 articles identified through the electronic database search, 6 RaCTs were included. Qualitative review was favoured over meta-analysis due to substantial methodological heterogeneity between studies. Five studies were at high risk for bias determined by the Cochrane Risk-of-Bias 2 tool. Diode LAI demonstrated superior efficacy to needle irrigation in reducing pain 6-48 h post-treatment. The impact of LAI by photon-induced photoacoustic streaming (PIPS) was unclear and no difference was observed between PIPS and needle irrigation. However, PIPS mitigated PEP better than manual dynamic activation, sonic and ultrasonic activation. There was no difference in analgesia intake between LAI and needle irrigation groups. CONCLUSIONS: LAI may help reduce PEP in the first 48 h. Methodological standardisation of future RaCTs on LAI would be beneficial in allowing a more accurate review with the possibility of quantitative synthesis. CLINICAL SIGNIFICANCE: This unique synthesis used stringent criteria to reduce confounding factors and provided valuable evidence regarding PEP with different types of LAI. It helps clinicians choose an appropriate LAI technique as compared with CNI and predicts a time frame for reducing PEP.


Assuntos
Dor Pós-Operatória , Tratamento do Canal Radicular , Irrigação Terapêutica , Humanos , Dor Pós-Operatória/prevenção & controle , Dor Pós-Operatória/etiologia , Irrigação Terapêutica/métodos , Tratamento do Canal Radicular/métodos , Irrigantes do Canal Radicular/uso terapêutico , Preparo de Canal Radicular/métodos , Preparo de Canal Radicular/instrumentação , Ensaios Clínicos Controlados Aleatórios como Assunto , Lasers , Adulto , Medição da Dor
11.
J Endod ; 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38880472

RESUMO

INTRODUCTION: This study systematically reviewed literature regarding the effect of different concentrations of sodium hypochlorite (NaOCl) used during root canal treatment (RCT) on postendodontic pain (PEP) and rescue analgesia. METHODS: Following registration with PROSPERO (CRD42023388916), a search was conducted using PubMed, Scopus, Web of Science, and Embase databases. Randomized controlled trials of patients receiving RCT which assessed PEP at different time intervals were included. Following data extraction and Cochrane risk of bias assessment 2, meta-analyses were performed to evaluate PEP during the first 48 hours along with rescue analgesic intake. The certainty of the evidence was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluation approach. RESULTS: Five randomized controlled trials with 674 patients were included. One study exhibited a low risk of bias, while 4 raised some concerns. Patients treated with low concentrations of NaOCl (≤3%) were significantly less likely to report PEP at 24 hours (OR = 2.32; [95% CI, 1.63-3.31]; P < .05) and 48 hours (OR = 2.49; [95% CI, 1.73-3.59]; P < .05) as compared with high concentrations of NaOCl (≥5%). Furthermore, with low concentrations of NaOCl, significantly lesser moderate-severe PEP was reported at 24 hours (OR = 2.32; [95% CI, 1.47-3.62]; P < .05) and 48 hours (OR = 2.35; [95% CI, 1.32-4.16]; P < .05) and lesser analgesia was needed (OR = 2.43; [95% CI, 1.48-4.00]; P < .05). CONCLUSIONS: While PEP can be influenced by several factors, low certainty evidence suggests that when NaOCl is used as an irrigant during RCT, PEP may be less likely with lower concentrations of NaOCl. Moderate certainty evidence indicates that lesser analgesia may be required with lower concentrations of NaOCl. These results should be cautiously interpreted.

12.
BDJ Open ; 10(1): 67, 2024 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-39179553

RESUMO

OBJECTIVES: This study compared the whitening effect, microhardness, and enamel surface alterations of over-the-counter (OTC) tooth bleaching products with those of a dentist-prescribed at-home bleaching agent. MATERIALS AND METHODS: The products available on a popular online marketplace were comprehensively searched and then rated using a specific formula. The effects of the lowest-rated OTC agent (LRA) and the highest-rated OTC agent (HRA) were compared with those of a dentist-prescribed bleaching agent (DPA) on the enamel of extracted human teeth. The bleaching efficacy, post-bleaching microhardness changes, and morphological alterations were assessed by spectrophotometric analysis, Vickers hardness testing, and scanning electron microscopy (SEM) respectively. Statistical analyses included one-way ANOVA and post hoc tests, maintaining a significance level of P < 0.05. RESULTS: The search of the online marketplace revealed 15 products. The LRA (Teeth Whitening Serum Gel, GEN, China) and the HRA (Bright White-Lovely Smile Premium Teeth Whitening strips, Ray of Smile, USA) were identified on the basis of their ranking. DPA resulted in significantly better tooth whitening than did LRA. The enamel microhardness was lower in the LRA treatment group (14.2%) than in the control and HRA treatment groups (8.84% and 7.26%, respectively). LRA also caused severe topographical alterations to the enamel. CONCLUSION: Compared with the poorly rated product, the dentist-prescribed tooth bleaching product resulted in greater colour improvement, less microhardness reduction, and surface changes. The highest-rated product was comparable with the dentist-prescribed agent in this study.

13.
Biochem Biophys Res Commun ; 440(1): 68-75, 2013 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-24041690

RESUMO

Using different maximum-likelihood models of adaptive evolution, signatures of natural selective pressure, operating across the naphthalene family of dioxygenases, were examined. A lineage- and branch-site specific combined analysis revealed that purifying selection pressure dominated the evolutionary history of the enzyme family. Specifically, episodic positive Darwinian selection pressure, affecting only a few sites in a subset of lineages, was found to be responsible for the evolution of nitroarene dioxygenases (NArDO) from naphthalene dioxygenase (NDO). Site-specific analysis confirmed the absence of diversifying selection pressure at any particular site. Different sets of positively selected residues, obtained from branch-site specific analysis, were detected for the evolution of each NArDO. They were mainly located around the active site, the catalytic pocket and their adjacent regions, when mapped onto the 3D structure of the α-subunit of NDO. The present analysis enriches the current understanding of adaptive evolution and also broadens the scope for rational alteration of substrate specificity of enzyme by directed evolution.


Assuntos
Bactérias/enzimologia , Dioxigenases/genética , Evolução Molecular , Complexos Multienzimáticos/genética , Bactérias/química , Bactérias/genética , Bactérias/metabolismo , Dioxigenases/química , Dioxigenases/metabolismo , Complexos Multienzimáticos/química , Complexos Multienzimáticos/metabolismo , Nitrocompostos/metabolismo , Filogenia
14.
Acta Odontol Scand ; 71(6): 1594-8, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23638768

RESUMO

OBJECTIVE: This study analyzed the antimicrobial effect of five irrigants formulated from different parts of the tree Azadirachta indica (Neem) and compared with 2.5% sodium hypochlorite and 0.2% chlorhexidine gluconate through an agar diffusion test. MATERIALS AND METHODS: A clinical isolate of Candida albicans was innoculated on Sabourad Dextrose Agar and Enterococcus faecalis (ATCC 29212) on Sheep Blood Agar. Wells with 6 mm diameter were created in agar and 100 µL aliquiots of each irrigant were introduced to five different wells. After incubation, the largest uniform diameter of the inhibition zone was recorded. RESULTS: The leaf extract of the tree and a mixture of the seed-bark powder dissolved in dimethyl sulfoxide were active against both organisms. The other neem-based irrigants, a leaf powder dissolved in dimethyl sulfoxide, aqueous bark decoction and neem oil, did not possess any antimicrobial efficacy. Sodium hypochlorite completely inhibited growth of C. albicans and the leaf extract had larger inhibition zones than chlorhexidine (p = 0.011) or the seed-bark irrigant (p = 0.008). Against E. faecalis, inhibition zones with chlorhexidine were the largest and differed significantly from sodium hypochlorite (p = 0.039), leaf extract (p = 0.008) and seed-bark irrigant (p = 0.011). CONCLUSIONS: Two neem irrigants displayed antimicrobial properties. The efficacy of the standard endodontic irrigants varied depending on the organisms tested. CLINICAL RELEVANCE: Neem-based endodontic irrigants may be formulated for clinical application.


Assuntos
Anti-Infecciosos/farmacologia , Azadirachta/química , Endodontia , Irrigantes do Canal Radicular/farmacologia , Candida albicans/efeitos dos fármacos , Enterococcus faecalis/efeitos dos fármacos , Técnicas In Vitro , Testes de Sensibilidade Microbiana
15.
Med Phys ; 50(3): 1560-1572, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36354289

RESUMO

PURPOSE: To propose a robust time and space invariant deep learning (DL) method to directly estimate the pharmacokinetic/tracer kinetic (PK/TK) parameters from undersampled dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) data. METHODS: DCE-MRI consists of 4D (3D-spatial + temporal) data and has been utilized to estimate 3D (spatial) tracer kinetic maps. Existing DL architecture for this task needs retraining for variation in temporal and/or spatial dimensions. This work proposes a DL algorithm that is invariant to training and testing in both temporal and spatial dimensions. The proposed network was based on a 2.5-dimensional Unet architecture, where the encoder consists of a 3D convolutional layer and the decoder consists of a 2D convolutional layer. The proposed VTDCE-Net was evaluated for solving the ill-posed inverse problem of directly estimating TK parameters from undersampled k - t $k-t$ space data of breast cancer patients, and the results were systematically compared with a total variation (TV) regularization based direct parameter estimation scheme. In the breast dataset, the training was performed on patients with 32 time samples, and testing was carried out on patients with 26 and 32 time samples. Translation of the proposed VTDCE-Net for brain dataset to show the generalizability was also carried out. Undersampling rates (R) of 8× , 12× , and 20× were utilized with PSNR and SSIM as the figures of merit in this evaluation. TK parameter maps estimated from fully sampled data were utilized as ground truth. RESULTS: Experiments carried out in this work demonstrate that the proposed VTDCE-Net outperforms the TV scheme on both breast and brain datasets across all undersampling rates. For K trans $\mathbf {K_{trans}}$ and V p $\mathbf {V_{p}}$ maps, the improvement over TV is as high as 2 and 5 dB, respectively, using the proposed VTDCE-Net. CONCLUSION: Temporal points invariant DL network that was proposed in this work to estimate the TK-parameters using DCE-MRI data has provided state-of-the-art performance compared to standard image reconstruction methods and is shown to work across all undersampling rates.


Assuntos
Neoplasias Encefálicas , Imageamento por Ressonância Magnética , Humanos , Imageamento por Ressonância Magnética/métodos , Redes Neurais de Computação , Encéfalo/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Algoritmos
16.
IEEE Trans Nanobioscience ; 21(4): 529-541, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-34847037

RESUMO

The need for innovation in medical device technology is immense; especially to replace dialysis techniques the necessity is extremely high. Available techniques that promised to replace dialysis have not yet geared up to the marketization level. The utilization of live kidney cells makes these devices costly, delicate, and unreliable. This paper aims to design a bioreactor to mimic the reabsorption function of the kidney that is fully artificial and highly controllable, which can be one step forward to the emerging Kidney-on-Chip (KOC) technology. The additional benefit of the proposed design is that it utilizes size-dependent reabsorption along with charge-dependent reabsorption phenomena to make it more compatible with human kidney function. The electrophoresis (EP), and di-electrophoresis (DEP) techniques are utilized to mimic the reabsorption function in this report. The structure utilized in the present design exactly replicates the proximal convoluted tubule (PCT) dimensions and functions as well. The whole setup is implemented in the COMSOL Multiphysics FEM benchmark tool for simulation, and analysis with appropriate boundary conditions. The device when excited by an electric field, Electrophoresis has produced a maximum velocity of 1.07 m/s for DC excitation and di-electrophoresis has produced a maximum flow velocity of 1.23 m/s, where both the offset voltages are the same (0.7 V). The flow velocity obtained utilizing both EP and DEP produced a reabsorption rate of 50-58% depending on the voltage applied and dimensions considered which is close to 60% reabsorption rate of the normal human kidney PCT. In accordance with the outcomes produced, the di-electrophoresis technique proved to be more efficient in realizing bioreactor as compared to electrophoresis. The novelty of the present work lies in the creation of a simulation environment, rigorous analysis, and optimization of the bioreactor supported by compact mathematical model.


Assuntos
Túbulos Renais Proximais , Microfluídica , Reatores Biológicos , Eletroforese/métodos , Humanos , Rim
17.
Biomicrofluidics ; 16(4): 041501, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35992641

RESUMO

This review provides a detailed literature survey on microfluidics and its road map toward kidney-on-chip technology. The whole review has been tailored with a clear description of crucial milestones in regenerative medicine, such as bioengineering, tissue engineering, microfluidics, microfluidic applications in biomedical engineering, capabilities of microfluidics in biomimetics, organ-on-chip, kidney-on-chip for disease modeling, drug toxicity, and implantable devices. This paper also presents future scope for research in the bio-microfluidics domain and biomimetics domain.

18.
Environ Sci Pollut Res Int ; 29(25): 37930-37953, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35072883

RESUMO

In the present study, we have estimated the emission factors (EFs) of particulate matter (PM), organic and elemental carbon (OC and EC), oxide of sulfur and nitrogen, and water-soluble ionic species emitted from residential fuels (fuelwood, crop residue, dung cake) used in the rural sector of five states (Kerala, Karnataka, Andhra Pradesh, Telangana, Tamil Nadu) of the southern region of India. Average EFs of PM, OC, and EC from fuelwood (FW), crop residues (CR), and dung cakes (DC) from southern region of India are estimated as follows: PM: 6.35 ± 5.64 g/kg (FW), 6.99 ± 5.46 g/kg (CR), 9.69 ± 3.73 g/kg (DC); OC: 1.60 ± 1.72 g/kg (FW), 1.50 ± 1.52 g/kg (CR), 3.54 ± 0.75 g/kg (DC); and EC: 0.46 ± 0.53 g/kg (FW), 0.29 ± 0.17 g/kg (CR), 0.21 ± 0.11 g/kg (DC), respectively. Similarly, the average EFs of SO2, NOx from FW, CR, and DC are determined to be as follows: SO2: 0.40 ± 0.37 g/kg (FW), 1.17 ± 0.25 g/kg (CR), and 0.18 ± 0.10 g/kg (DC); NOx: 1.11 ± 1.22 g/kg (FW), 0.69 ± 0.37 g/kg (CR), and 0.91 ± 0.54 g/kg (DC), respectively. PO43- shows the highest EF from FW (646.02 ± 576.35 mg/kg), CR (531.06 ± 678.29 mg/kg) among all anions followed by Cl- (FW: 512.91 ± 700.35 mg/kg, CR: 661.61 ± 865.46 mg/kg and DC: 104.16 ± 54.01 mg/kg); whereas, Na+ shows highest EF from FW (254.05 ± 298.50 mg/kg) and CR (249.36 ± 294.85 mg/kg) among all cations. The total emissions of trace gases, PM, and their chemical composition from FW, CR, and DC have been calculated using laboratory-generated EFs over the southern region of India. CR (1595.58 ± 14.24 Gg) contributes to higher emission of PM as compared to FW (218.78 ± 53.93 Gg), whereas the contribution from DC is negligible.


Assuntos
Poluentes Atmosféricos , Poluentes Atmosféricos/análise , Carbono/análise , Monitoramento Ambiental , Gases , Índia , Material Particulado/análise
19.
PLoS One ; 16(7): e0250301, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34260597

RESUMO

Though it is often taken as a truism that communication contributes to organizational productivity, there are surprisingly few empirical studies documenting a relationship between observable interaction and productivity. This is because comprehensive, direct observation of communication in organizational settings is notoriously difficult. In this paper, we report a method for extracting network and speech characteristics data from audio recordings of participants talking with each other in real time. We use this method to analyze communication and productivity data from seventy-nine employees working within a software engineering organization who had their speech recorded during working hours for a period of approximately 3 years. From the speech data, we infer when any two individuals are talking to each other and use this information to construct a communication graph for the organization for each week. We use the spectral and temporal characteristics of the produced speech and the structure of the resultant communication graphs to predict the productivity of the group, as measured by the number of lines of code produced. The results indicate that the most important speech and network features for predicting productivity include those that measure the number of unique people interacting within the organization, the frequency of interactions, and the topology of the communication network.


Assuntos
Comunicação , Eficiência Organizacional , Humanos
20.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 5932-5935, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34892469

RESUMO

The study of human reaction time (RT) is invaluable not only to understand the sensory-motor functions but also to translate brain signals into machine comprehensible commands that can facilitate augmentative and alternative communication using brain-computer interfaces (BCI). Recent developments in sensor technologies, hardware computational capabilities, and neural network models have significantly helped advance biomedical signal processing research. This study is an attempt to utilize state-of-the-art resources to explore the relationship between human behavioral responses during perceptual decision-making and corresponding brain signals in the form of electroencephalograms (EEG). In this paper, a generalized 3D convolutional neural network (CNN) architecture is introduced to estimate RT for a simple visual task using single-trial multi-channel EEG. Earlier comparable studies have also employed a number of machine learning and deep learning-based models, but none of them considered inter-channel relationships while estimating RT. On the contrary, the use of 3D convolutional layers enabled us to consider the spatial relationship among adjacent channels while simultaneously utilizing spectral information from individual channels. Our model can predict RT with a root mean square error of 91.5 ms and a correlation coefficient of 0.83. These results surpass all the previous results attained from different studies.Clinical relevance Novel approaches to decode brain signals can facilitate research on brain-computer interfaces (BCIs), psychology, and neuroscience, enabling people to utilize assistive devices by root-causing psychological or neuromuscular disorders.


Assuntos
Interfaces Cérebro-Computador , Eletroencefalografia , Humanos , Aprendizado de Máquina , Redes Neurais de Computação , Tempo de Reação
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