Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 53
Filtrar
1.
Arch Oral Biol ; 160: 105898, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38278126

RESUMO

OBJECTIVE: Head and neck cancer (HNC) is a prevalent and complex group of malignancies with increasing incidence globally. Alcohol dehydrogenases (ADHs) play a crucial role in alcohol metabolism, and their polymorphisms have been linked to HNC risk. This systematic review and meta-analysis aims to evaluate the association between ADH polymorphisms and susceptibility to HNCs, incorporating additional analyses and adding more studies to increase power and accuracy of the results. DESIGN: Subgroup analysis, meta-regression analysis, and sensitivity analyses were conducted to explore potential differences within the data and assess the stability of pooled odds ratios (ORs). To mitigate the risk of false conclusions from meta-analyses, a trial sequential analysis was performed. RESULTS: For ADH1B rs1229984, the pooled OR (95 % confidence interval (CI)) was 0.73 (0.65, 0.82), 0.42 (0.35, 0.50), 0.57 (0.44, 0.73), 0.56 (0.50, 0.62), and 0.80 (0.73, 0.88), as well as for ADH7 rs1573496, the pooled OR was 0.72 (0.62, 0.85), 0.36 (0.17, 0.74), 0.76 (0.64, 0.91), 0.80 (0.71, 0.91), and 0.38 (0.18, 0.78) with a p < 0.05 in all allelic, homozygous, heterozygous, recessive, and dominant models, respectively. However, no significant association was found between the ADH7 rs1154460 and rs284787 polymorphisms and the risk of HNC with pooled ORs of 1.11 (p = 0.19) and 1.09 (p = 0.24) for the recessive model, respectively. The ethnicities, tumor subsites, control sources, sample sizes, quality scores, and Hardy-Weinberg equilibrium statuses were confounding factors. CONCLUSION: The ADH1B rs1229984 and ADH7 rs1573496 polymorphisms are significantly associated with a reduced risk of HNC.


Assuntos
Álcool Desidrogenase , Neoplasias de Cabeça e Pescoço , Humanos , Álcool Desidrogenase/genética , Polimorfismo Genético , Neoplasias de Cabeça e Pescoço/genética , Heterozigoto , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único
2.
BMC Complement Med Ther ; 24(1): 56, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-38273247

RESUMO

AIMS: Thymus plant is a very useful herbal medicine with various properties such as anti-inflammatory and antibacterial. Therefore, the properties of this plant have made this drug a suitable candidate for wound healing. In this study, hydroxypropyl methylcellulose (HPMC) gel containing Zataria multiflora volatile oil nanoemulsion (neZM) along with polycaprolactone/chitosan (PCL-CS) nanofibrous scaffold was used, and the effect of three experimental groups on the wound healing process was evaluated. The first group, HPMC gel containing neZM, the second group, PCL-CS nanofibers, and the third group, HPMC gel containing neZM and bandaged with PCL-CS nanofibers (PCL-CS/neZM). Wounds bandaged with common sterile gas were considered as control. METHODS: The nanoemulsion was synthesized by a spontaneous method and loaded into a hydroxypropyl methylcellulose (HPMC) gel. The DLS test investigated the size of these nanoemulsions. A PCL-CS nanofibrous scaffold was also synthesized by electrospinning method then SEM and contact angle tests investigated morphology and hydrophilicity/hydrophobicity of its surface. The animal study was performed on full-thickness skin wounds in rats, and the process of tissue regeneration in the experimental and control groups was evaluated by H&E and Masson's trichrome staining. RESULTS: The results showed that the nanoemulsion has a size of 225±9 nm and has an acceptable dispersion. The PCL-CS nanofibers synthesized by the electrospinning method also show non-beaded smooth fibers and due to the presence of chitosan with hydrophilic properties, have higher surface hydrophobicity than PCL fibers. The wound healing results show that the PCL-CS/neZM group significantly reduced the wound size compared to the other groups on the 7th, 14th, and 21st days. The histological results also show that the PCL-CS/neZM group could significantly reduce the parameters of edema, inflammation, and vascularity and increase the parameters of fibrosis, re-epithelialization, and collagen deposition compared to other groups on day 21. CONCLUSION: The results of this study show that the PCL-CS/neZM treatment can effectively improve wound healing.


Assuntos
Quitosana , Óleos Voláteis , Poliésteres , Ratos , Animais , Quitosana/farmacologia , Óleos Voláteis/farmacologia , Derivados da Hipromelose/farmacologia , Cicatrização
3.
Nanomedicine (Lond) ; 18(24): 1745-1768, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37965906

RESUMO

This review discusses the application of nanoliposomes containing siRNA/drug to overcome multidrug resistance for all types of cancer treatments. As drug resistance-associated factors are overexpressed in many cancer cell types, pumping chemotherapy drugs out of the cytoplasm leads to an inadequate therapeutic response. The siRNA/drug-loaded nanoliposomes are a promising approach to treating multidrug-resistant cancer, as they can effectively transmit a small-molecule drug into the target cytoplasm, ensuring that the drug binds efficiently. Moreover, nanoliposome-based therapeutics with advances in nanotechnology can effectively deliver siRNA to cancer cells. Overall, nanoliposomes have the potential to effectively deliver siRNA and small-molecule drugs in a targeted manner and are thus a promising tool for the treatment of cancer and other diseases.


Assuntos
Antineoplásicos , Nanopartículas , Neoplasias , Humanos , Resistencia a Medicamentos Antineoplásicos , RNA Interferente Pequeno , Resistência a Múltiplos Medicamentos , Lipossomos/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/genética
4.
Mol Biotechnol ; 65(12): 1935-1953, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37017917

RESUMO

Material engineering is a fundamental issue in the applications of materials in the medical field. One of the aspects of material engineering is incorporating recognition sites on the surface of biomaterials, which plays an essential role in increasing the efficiency of tissue engineering scaffolds in various aspects. The application of peptides and antibodies to establish the recognition and adhesion sites has limitations, such as fragility and instability under physical and chemical processes. Therefore, synthetic ligands such as nucleic acid aptamers have received much attention for easy synthesis, minimal immunogenicity, high specificity, and stability under processing. Due to the effective role of these ligands in increasing the efficiency of engineered constructs in this study, the advantages of nucleic acid aptamers in tissue engineering will be reviewed. Aptamer-functionalized biomaterials can attract endogenous stem cells to wounded areas and organize their actions to facilitate tissue regeneration. This approach harnesses the body's inherent regeneration potential to treat many diseases. Also, increased efficacy in controlled release, slow and targeted drug delivery are important issues in drug delivery for tissue engineering approaches which can be achieved by incorporating aptamers in drug delivery systems. Aptamer-functionalized scaffolds have very applications, such as diagnosis of cancer, hematological infections, narcotics, heavy metals, toxins, controlled release from the scaffolds, and in vivo cell tracing. Aptasensors, as a result of many advantages over other traditional assay methods, can replace older methods. Furthermore, their unique targeting mechanism also targets compounds with no particular receptors. Targeting cell homing, local and targeted drug delivery, cell adhesion efficacy, cytocompatibility and bioactivity of scaffolds, aptamer-based biosensor, and aptamer-functionalized scaffolds are the topics that will be examined in this review study.


Assuntos
Aptâmeros de Nucleotídeos , Ácidos Nucleicos , Engenharia Tecidual/métodos , Medicina Regenerativa , Preparações de Ação Retardada , Aptâmeros de Nucleotídeos/genética , Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/uso terapêutico , Materiais Biocompatíveis , Ligantes
5.
Int J Pharm ; 633: 122615, 2023 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-36657555

RESUMO

Cutaneous leishmaniasis (CL) is a global public health issue. Conventional treatments have substantial costs, side effects, and parasite resistance. Due to easy application and inexpensive cost, topical treatment is the optimal approach for CL. It could be used alone or with systemic treatments. Electrospun fibers as drug release systems in treating skin lesions have various advantages such as adjustable drug release rate, maintaining appropriate humidity and temperature, gas exchange, plasticity at the lesion site, similarity with the skin extracellular matrix (ECM) and drug delivery with high efficiency. Hydrogels are valuable scaffolds in the treatment of skin lesions. The important features of hydrogels include preserving unstable drugs from degradation, absorption of wound secretions, high biocompatibility, improving the re-epithelialization of the wound and preventing the formation of scars. One of the issues in local drug delivery systems for the skin is the low permeability of drugs in the skin. Polymeric scaffolds that are designed as microneedle patches can penetrate the skin and overcome this challenge. Also, drug delivery using nanocarriers increases the effectiveness of drugs in lower and more tolerable doses and reduces the toxicity of drugs. The application of cell therapy in the treatment of parasitic and infectious diseases has been widely investigated. The complexity of leishmaniasis treatment requires identifying new treatment options like cell therapy to overcome the disease. Topics investigated in this study include drug delivery systems based on tissue engineering scaffolds, nanotechnology and cell therapy-based studies to reduce the complications of CL.


Assuntos
Leishmaniose Cutânea , Engenharia Tecidual , Humanos , Leishmaniose Cutânea/tratamento farmacológico , Nanotecnologia , Terapia Baseada em Transplante de Células e Tecidos , Hidrogéis/uso terapêutico
6.
Cell Biochem Funct ; 41(1): 20-32, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36468539

RESUMO

An imbalance between caloric intake and energy expenditure leads to obesity. Obesity is an important risk factor for the development of several metabolic diseases including insulin resistance, metabolic syndrome, type 2 diabetes mellitus, and cardiovascular disease. So, controlling obesity could be effective in the improvement of obesity-related diseases. Various factors are involved in obesity, such as AMP-activated protein kinases (AMPK), silent information regulators, inflammatory mediators, oxidative stress parameters, gastrointestinal hormones, adipokines, angiopoietin-like proteins, and microRNAs. These factors play an important role in obesity by controlling fat metabolism, energy homeostasis, food intake, and insulin sensitivity. AMPK is a heterotrimeric serine/threonine protein kinase known as a fuel-sensing enzyme. The central role of AMPK in obesity makes it an attractive molecule to target obesity and related metabolic diseases. In this review, the critical role of AMPK in obesity and the interplay between AMPK and obesity-associated factors were elaborated.


Assuntos
Proteínas Quinases Ativadas por AMP , Resistência à Insulina , Obesidade , Humanos , Proteínas Quinases Ativadas por AMP/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Metabolismo Energético/fisiologia , Resistência à Insulina/fisiologia , Doenças Metabólicas , Obesidade/complicações , Obesidade/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo
7.
J Cancer Res Ther ; 19(7): 1982-1987, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38376307

RESUMO

AIM: According to the literature, high levels of salivary soluble E-cadherin may be lined to advanced stage and poor prognosis in cancers. This research aimed at comparing salivary and serum levels of soluble E-cadherin in cases with esophageal, gastric, and colorectal cancers. METHODS: This case-control research was performed on 68 patients with gastrointestinal cancers and 57 healthy volunteers as a control group to measure salivary and serum levels of soluble E-cadherin using ELISA kits. RESULTS: The results showed a statistically significant difference between salivary and serum levels of soluble E-cadherin in the case group, as opposed to the control group (P = 0.031). The salivary level of soluble E-cadherin in the control group was 2.138 ng/mL on average lower than that that in the case group. The median salivary level of soluble E-cadherin among cases with lymph node involvement was significantly higher compared with its median level in the control group (P = 0.049). Soluble E-cadherin salivary level and other variables, such as metastasis and cancer stage, were directly correlated, but it was not statistically significant. CONCLUSION: According to the findings, the salivary level of soluble E-cadherin among cases with gastric cancer could be considered as a prognostic marker, but the diagnostic value of saliva could not be judged in esophageal and colorectal cancers because of small sample size, and more investigations are required for a definite conclusion.


Assuntos
Neoplasias Colorretais , Neoplasias Gastrointestinais , Neoplasias Gástricas , Humanos , Caderinas , Ensaio de Imunoadsorção Enzimática , Neoplasias Gastrointestinais/diagnóstico , Estudos de Casos e Controles
8.
Regen Med ; 17(11): 855-876, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36065834

RESUMO

In this review, gene delivery and its applications are discussed in tissue engineering (TE); also, new techniques such as the CRISPR-Cas9 system, synthetics biology and molecular dynamics simulation to improve the efficiency of the scaffolds have been studied. CRISPR-Cas9 is expected to make significant advances in TE in the future. The fundamentals of synthetic biology have developed powerful and flexible methods for programming cells via artificial genetic circuits. The combination of regenerative medicine and artificial biology allows the engineering of cells and organisms for use in TE, biomaterials, bioprocessing and scaffold development. The dynamics of protein adsorption at the scaffold surface at the atomic level can provide valuable guidelines for the future design of TE scaffolds /implants.


Assuntos
Engenharia Tecidual , Tecidos Suporte , Materiais Biocompatíveis , Técnicas de Transferência de Genes , Medicina Regenerativa/métodos , Engenharia Tecidual/métodos
9.
Toxicol Appl Pharmacol ; 441: 115989, 2022 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-35314202

RESUMO

Due to recent advances in the field of small molecule-based drugs, designing an efficient siRNA delivery system seems essential. Here, modified sets of lipids conjugated with cell-penetrating TAT peptide, MMP2 enzyme-sensitive moiety, and cetuximab antibodies against the EGF receptor were synthesized, purified and verified on HPLC, TLC, SEM, and DLS analyses. Different cellular and molecular experiments were designed to evaluate the transfection efficiency, targeting properties, and functions, including cytotoxicity assay, resensitization assessments, flow cytometry-based uptake assay, BCRP silencing efficiency, real-time PCR, and western blotting. The final targeted liposomes represented an average diameter of 160 nm; zeta-potential and siRNA encapsulation rates were respectively around -28.9 ± 3.16 mV and 88.3 ± 0.9 w/w. The siBCRP carried by the TAT+Cetuximab+ liposome led to an increase in the tumoricidal effect of mitoxantrone by a reduction in IC50 value by 4-fold (*** P < 0.001). Flow cytometry results showed that the cellular uptake rate of final immunoliposomes was significantly higher than the naked liposomes (*** P < 0.001). The Targeted siRNA encapsulating liposomes decreased BCRP transcript and protein levels in MCF7-MX cells by 0.24 and 0.2-fold after 48 h, respectively. Due to the silencing results of the BCRP by the encapsulated siRNA and the inhibitory effects of cetuximab on the EGFR, this formulation could widely be utilized as a carrier for tumor-directed gene delivery.


Assuntos
Neoplasias da Mama , Nanopartículas , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Cetuximab/farmacologia , Resistência a Múltiplos Medicamentos , Feminino , Humanos , Lipossomos , Nanopartículas/química , Proteínas de Neoplasias , RNA Interferente Pequeno/genética
10.
IEEE Trans Biomed Eng ; 69(5): 1685-1695, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34757899

RESUMO

OBJECTIVE: Considering the knee as a fluid-lubricated system, articulating surfaces undergo different lubrication modes and generate joint acoustic emissions (JAEs). The goal of this study is to compare knee biomechanical signals against synchronously recorded joint sounds and assess the hypothesis that JAEs are attributed to tribological origins. METHODS: JAE, electromyography, ground reaction force signals, and motion capture markers were synchronously recorded from ten healthy subjects while performing two-leg and one-leg squat exercises. The biomechanical signals were processed to calculate a tribological parameter, lubrication coefficient, and JAEs were divided into short windows and processed to extract 64-time-frequency features. The lubrication coefficients and JAE features of two-leg squats were used to label the windows and train a classifier that discriminates the knee lubrication modes only based on JAE features. RESULTS: The classifier was used to predict the label of one-leg squat JAE windows and it achieved a high test-accuracy of 84%. The Pearson correlation coefficient between the estimated friction coefficient and predicted JAE scores was 0.83 ± 0.08. Furthermore, the lubrication coefficient threshold, separating two lubrication modes, decreased by half from two-leg to one-leg squats. This result was consistent with tribological changes in the knee load as it was inversely doubled in one-leg squats. SIGNIFICANCE: This study supports the potential use of JAEs as a quantitative biomarker to extract tribological information. Since arthritis and similar disease impact the roughness of the joint cartilage, the use of JAEs could have broad implications for studying joint frictions and monitoring joint structural changes with wearable devices.


Assuntos
Acústica , Articulação do Joelho , Fenômenos Biomecânicos , Estudos de Viabilidade , Fricção , Humanos , Postura
11.
Pesqui. bras. odontopediatria clín. integr ; 22: e210001, 2022. tab, graf
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1422261

RESUMO

Abstract Objective: To evaluate the level of pain experienced during infiltration anesthesia of the anterior maxilla following low-level laser therapy (LLLT) with 810-980 nm wavelengths. Material and Methods: In the current triple-blind clinical trial, 84 patients received a total of 168 infiltration anesthesia injections (1.8 mL of 2% lidocaine plus 1:100,000 epinephrine) in the anterior maxilla. Each patient received two injections into the buccal mucosa of the right and left central incisors with a two-week interval. One injection was performed after LLLT, while the other injection was administered conventionally without laser. The pain level was measured immediately after injection using a visual analog scale (VAS). Results: There was a significant difference in the pain level experienced with and without LLLT, such that the mean pain score following LLLT was significantly lower than that without LLLT (p<0.05). No significant difference was found in the pain level between laser and no laser groups in males, but the difference in this regard was significant in females (p<0.05) and female patients experienced a significantly lower level of pain following LLLT. Conclusion: The low-level laser therapy can be successfully used to decrease the level of pain experienced during infiltration anesthesia of the anterior maxilla (AU).


Assuntos
Humanos , Masculino , Feminino , Adulto , Dor , Terapia com Luz de Baixa Intensidade/instrumentação , Anestesia Local , Maxila , Método Duplo-Cego , Estatísticas não Paramétricas , Escala Visual Analógica
12.
Future Virol ; 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34858516

RESUMO

This article provides a brief overview of DNA vaccines. First, the basic DNA vaccine design strategies are described, then specific issues related to the industrial production of DNA vaccines are discussed, including the production and purification of DNA products such as plasmid DNA, minicircle DNA, minimalistic, immunologically defined gene expression (MIDGE) and Doggybone™. The use of adjuvants to enhance the immunogenicity of DNA vaccines is then discussed. In addition, different delivery routes and several physical and chemical methods to increase the efficacy of DNA delivery into cells are explained. Recent preclinical and clinical trials of DNA vaccines for COVID-19 are then summarized. Lastly, the advantages and obstacles of DNA vaccines are discussed.

13.
IEEE Sens J ; 21(12): 13676-13684, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34658673

RESUMO

We present a new method for quantifying signal quality of joint acoustic emissions (JAEs) from the knee during unloaded flexion/extension (F/E) exercises. For ten F/E cycles, JAEs were recorded, in a clinical setting, from 34 healthy knees and 13 with a meniscus tear (n=24 subjects). The recordings were first segmented by F/E cycle and described using time and frequency domain features. Using these features, a symmetric k-nearest neighbor graph was created and described using a spectral embedding. We show how the underlying community structure of JAEs was comparable across joint health levels and was highly affected by artifacts. Each F/E cycle was scored by its distance from a diverse set of manually annotated, clean templates and removed if above the artifact threshold. We validate this methodology by showing an improvement in the distinction between the JAEs of healthy and injured knees. Graph community factor (GCF) was used to detect the number of communities in each recording and describe the heterogeneity of JAEs from each knee. Before artifact removal, there was no significant difference between the healthy and injured groups due to the impact of artifacts on the community construction. Following implementation of artifact removal, we observed improvement in knee health classification. The GCF value for the meniscus tear group was significantly higher than the healthy group (p<0.01). With more JAE recordings being taken in the clinic and at home, this paper addresses the need for a robust artifact removal method which is necessary for an accurate description of joint health.

14.
Cancer Epidemiol ; 75: 102041, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34592532

RESUMO

Vascular endothelial growth factor (VEGF) is one of the most important regulators of angiogenesis. Several single nucleotide polymorphisms (SNPs) are associated with the VEGF overexpression and tumor progression in several cancers. This study aimed to determine the association of VEGF rs833061 and rs2010963 polymorphism and their haplotypes with susceptibility to colorectal cancer (CRC) in the Iranian population. A total of 284 colorectal cancer patients (37.3% women, 62.7% men) were enrolled in this study. Healthy controls without evidence of cancer history or family cancer predispositions were frequency-matched to the cases by sex and age (± 5 years). Genotyping was performed by the Sequenom mass ARRAY method and the genotype distribution and risk estimate were analyzed by SPSS software. The correlation between the genotypes and clinicopathological parameters (Dukes stage, phenotype, location, differentiation, and tumor size) among colorectal cancer patients were investigated. We found a significant relationship, between rs833061T/C genotype and their TG haplotype with the age of diagnosis < 60; (p = 0.012, p = 0.014) and rs2010963G/C genotype with female gender and TG haplotype with third and fourth tumor stage and tumor location (p = 0.04and p = 0.047). This study showed that rs833061T/C genotype and TG haplotype increase the susceptibility to colon cancer in the Iranian population. This susceptibility has a significant relationship with the age of diagnosis and different stages of the tumor.


Assuntos
Neoplasias Colorretais , Fator A de Crescimento do Endotélio Vascular , Estudos de Casos e Controles , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/genética , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Haplótipos , Humanos , Irã (Geográfico)/epidemiologia , Masculino , Polimorfismo de Nucleotídeo Único , Fator A de Crescimento do Endotélio Vascular/genética
15.
Int Orthod ; 19(3): 346-352, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34305013

RESUMO

OBJECTIVE: Copeptin can act as a stable biomarker in inflammation and stress response that obstructive sleep apnoea syndrome (OSAS), can induce oxidative stress and consequently promotes systemic inflammation. The purpose of the study is to appraise serum copeptin level in adult patients with OSAS compared to the controls. MATERIAL AND METHODS: Electronic search was done in the databases of PubMed/Medline, Web of Science, Scopus, and Cochrane Library until June 2021, without any restrictions. For comparison of the serum copeptin level between groups, the mean difference (MD) and 95% confidence interval (CI) were calculated by the Review Manager 5.3 software. Trial sequential analysis (TSA) was used by applying TSA software. RESULTS: Among the databases, five articles (involving 495 OSAS patients and 135 controls) were included. To report the serum copeptin level in OSAS patients compared to controls, the pooled OR became 12.21pg/mL (95%CI: 2.31 to 22.11; P=0.02) and also the pooled OR for comparison of serum copeptin level in severe versus moderate/mild OSAS patients was 5.96pg/mL (95%CI: 1.46 to 10.47; P=0.009). The results of TSA illustrated that the Z-curve has not crossed the monitoring boundary curves and did not reach the required information size. CONCLUSIONS: The main findings recommended that copeptin had a significantly higher serum level in OSAS patients compared to controls, as well as a significantly higher level in severe patients compared to mild/moderate OSAS patients for the serum level of copeptin.


Assuntos
Glicopeptídeos , Apneia Obstrutiva do Sono , Adulto , Biomarcadores , Humanos , Inflamação
16.
J Vib Acoust ; 143(3): 031006, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34168416

RESUMO

In this study, we propose a new mounting method to improve accelerometer sensing performance in the 50 Hz-10 kHz frequency band for knee sound measurement. The proposed method includes a thin double-sided adhesive tape for mounting and a 3D-printed custom-designed backing prototype. In our mechanical setup with an electrodynamic shaker, the measurements showed a 13 dB increase in the accelerometer's sensing performance in the 1-10 kHz frequency band when it is mounted with the craft tape under 2 N backing force applied through low-friction tape. As a proof-of-concept study, knee sounds of healthy subjects (n = 10) were recorded. When the backing force was applied, we observed statistically significant (p < 0.01) incremental changes in spectral centroid, spectral roll-off frequencies, and high-frequency (1-10 kHz) root-mean-square (RMS) acceleration, while low-frequency (50 Hz-1 kHz) RMS acceleration remained unchanged. The mean spectral centroid and spectral roll-off frequencies increased from 0.8 kHz and 4.15 kHz to 1.35 kHz and 5.9 kHz, respectively. The mean high-frequency acceleration increased from 0.45 mgRMS to 0.9 mgRMS with backing. We showed that the backing force improves the sensing performance of the accelerometer when mounted with the craft tape and the proposed backing prototype. This new method has the potential to be implemented in today's wearable systems to improve the sensing performance of accelerometers in knee sound measurements.

17.
Ann Biomed Eng ; 49(9): 2399-2411, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33987807

RESUMO

The characteristics of joint acoustic emissions (JAEs) measured from the knee have been shown to contain information regarding underlying joint health. Researchers have developed methods to process JAE measurements and combined them with machine learning algorithms for knee injury diagnosis. While these methods are based on JAEs measured in controlled settings, we anticipate that JAE measurements could enable accessible and affordable diagnosis of acute knee injuries also in field-deployable settings. However, in such settings, the noise and interference would be greater than in sterile, laboratory environments, which could decrease the performance of existing knee health classification methods using JAEs. To address the need for an objective noise and interference detection method for JAE measurements as a step towards field-deployable settings, we propose a novel experimental data augmentation method to locate and then, remove the corrupted parts of JAEs measured in clinical settings. In the clinic, we recruited 30 participants, and collected data from both knees, totaling 60 knees (36 healthy and 24 injured knees) to be used subsequently for knee health classification. We also recruited 10 healthy participants to collect artifact and joint sounds (JS) click templates, which are audible, short duration and high amplitude JAEs from the knee. Spectral and temporal features were extracted, and clinical data was augmented in five-dimensional subspace by fusing the existing clinical dataset into experimentally collected templates. Then knee scores were calculated by training and testing a linear soft classifier utilizing leave-one-subject-out cross-validation (LOSO-CV). The area under the curve (AUC) was 0.76 for baseline performance without any window removal with a logistic regression classifier (sensitivity = 0.75, specificity = 0.78). We obtained an AUC of 0.86 with the proposed algorithm (sensitivity = 0.80, specificity = 0.89), and on average, 95% of all clinical data was used to achieve this performance. The proposed algorithm improved knee health classification performance by the added information through identification and collection of common artifact sources in JAE measurements. This method when combined with wearable systems could provide clinically relevant supplementary information for both underserved populations and individuals requiring point-of-injury diagnosis in field-deployable settings.


Assuntos
Articulação do Joelho/fisiologia , Processamento de Sinais Assistido por Computador , Acústica , Adolescente , Adulto , Artefatos , Feminino , Humanos , Aprendizado de Máquina , Masculino , Pessoa de Meia-Idade , Adulto Jovem
18.
Carbohydr Polym ; 260: 117802, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33712150

RESUMO

Due to the significance growth in application of polymer-based nanocomposites, different methods of synthesis and different reinforces have been studied in recent years for specific purposes. In this study, using the direct blending process, polyvinyl alcohol-arabic gum-magnesium oxide nanocomposites were synthesized. These synthesized nanocomposites were investigated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-ray energy diffraction (EDS) spectroscopy, X-ray surface elemental mapping (X-Ray Map), transmission electron microscopy (TEM), ultraviolet -visible (UV-vis) spectrophotometry and thermal gravimetery analysis (TGA). The results revealed that size distributions of magnesium oxide nanoparticles and synthesized nanocomposites were between 25-40 nm and 20-90 nm, respectively. Elemental map results show the magnesium oxide nanoparticles were well distributed on polymer matrix walls.


Assuntos
Goma Arábica/química , Óxido de Magnésio/química , Nanocompostos/química , Álcool de Polivinil/química , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Difração de Raios X
19.
Gene ; 781: 145524, 2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-33631241

RESUMO

BACKGROUND: Oral Cancer (OC) is one of the leading causes of death and the disease mainly occurs over 50 years of age. Herein, a meta-analysis aimed to assess the association between X-ray repair cross complementing (XRCC) polymorphisms and OC risk. METHODS: Four databases were searched extensively until June 5, 2020. Subgroup analysis, meta-regression, and funnel plots, as well as the quality assessment were estimated. RESULTS: Fifteen studies were entered to the analysis. With regards to allele, homozygote, heterozygote, recessive, and dominant models, the pooled ORs for XRCC1 rs1799782 polymorphism were 1.51 (P = 0.01), 1.45 (P = 0.11), 1.45 (P = 0.0003), 1.44 (P = 0.0002), and 1.29 (P = 0.26); for XRCC1 rs1799782 polymorphism were 1.65 (P = 0.11), 1.50 (P = 0.33), 1.06 (P = 0.83), 1.57 (P = 0.12), and 1.32 (P = 0.45); for XRCC1 rs25489 polymorphism were 0.01 (P = 0.19), 1.44 (P = 0.48), 1.21 (P = 0.72), 1.17 (P = 0.19), and 1.38 (P = 0.54); for XRCC2 rs2040639 polymorphism were 0.68 (P = 0.0002), 0.63 (P = 0.02), 0.95 (P = 0.92), 0.79 (P = 0.49), and 0.61 (P = 0.005); and for XRCC3 rs861539 polymorphism were 1.24 (P = 0.20), 1.28 (P = 0.48), 0.99 (P = 0.95), 1.15 (P = 0.46), and 1.52 (P = 0.15), respectively. CONCLUSIONS: The T allele and CT genotype of XRCC1 rs1799782 polymorphism had an elevated risk, whereas the G allele and GG genotype of XRCC2 rs2040639 polymorphism had a protective role in OC.


Assuntos
Reparo do DNA , Proteínas de Ligação a DNA/genética , Neoplasias Bucais/genética , Proteína 1 Complementadora Cruzada de Reparo de Raio-X/genética , Predisposição Genética para Doença , Humanos , Polimorfismo Genético
20.
Artigo em Inglês | MEDLINE | ID: mdl-33428572

RESUMO

Musculoskeletal disorders and injuries are one of the most prevalent medical conditions across age groups. Due to a high load-bearing function, the knee is particularly susceptible to injuries such as meniscus tears. Imaging techniques are commonly used to assess meniscus injuries, though this approach suffers from limitations including high cost, need for skilled personnel, and confinement to laboratory or clinical settings. Vibration-based structural monitoring methods in the form of acoustic emission analysis and vibration stimulation have the potential to address the limits associated with current diagnostic technologies. In this study, an active vibration measurement technique is employed to investigate the presence and severity of meniscus tear in cadaver limbs. In a highly controlled ex vivo experimental design, a series of cadaver knees (n =6) were evaluated under an external vibration, and the frequency response of the joint was analyzed to differentiate the intact and affected samples. Four stages of knee integrity were considered: baseline, sham surgery, meniscus tear, and meniscectomy. Analyzing the frequency response of injured legs showed significant changes compared to the baseline and sham stages at selected frequency bandwidths. Furthermore, a qualitative analytical model of the knee was developed based on the Euler-Bernoulli beam theory representing the meniscus tear as a change in the local stiffness of the system. Similar trends in frequency response modulation were observed in the experimental results and analytical model. These findings serve as a foundation for further development of wearable devices for detection and grading of meniscus tear and for improving our understanding of the physiological effects of injuries on the vibration characteristics of the knee. Such systems can also aid in quantifying rehabilitation progress following reconstructive surgery and / or during physical therapy.


Assuntos
Traumatismos do Joelho , Menisco , Lesões do Menisco Tibial , Fenômenos Biomecânicos , Humanos , Articulação do Joelho , Meniscos Tibiais , Modalidades de Fisioterapia , Vibração
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...