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1.
Mikrochim Acta ; 191(8): 456, 2024 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-38980419

RESUMO

Polydopamine (PDA) has garnered significant interest for applications in biosensors, drug delivery, and tissue engineering. However, similar polycatecholamines like polynorepinephrine (PNE) with additional hydroxyl groups and poly-α-methylnorepinephrine (PAMN) with additional hydroxyl and methyl groups remain unexplored in the biosensing domain. This research introduces three innovative biosensing platforms composed of ternary nanocomposite based on reduced graphene oxide (RGO), gold nanoparticles (Au NPs), and three sister polycatecholamine compounds (PDA, PNE, and PAMN). The study compares and evaluates the performance of the three biosensing systems for the ultrasensitive detection of Mycobacterium tuberculosis (MTB). The formation of the nanocomposites was meticulously examined through UV-Visible, Raman, XRD, and FT-IR studies with FE-SEM and HR-TEM analysis. Cyclic voltammetry and differential pulse voltammetry measurements were also performed to determine the electrochemical characteristics of the modified electrodes. Electrochemical biosensing experiments reveal that the RGO-PDA-Au, RGO-PNE-Au, and RGO-PAMN-Au-based biosensors detected target DNA up to a broad detection range of 0.1 × 10-8 to 0.1 × 10-18 M, with a low detection limit (LOD) of 0.1 × 10-18, 0.1 × 10-16, and 0.1 × 10-17 M, respectively. The bioelectrodes were proved to be highly selective with excellent sensitivities of 3.62 × 10-4 mA M-1 (PDA), 7.08 × 10-4 mA M-1 (PNE), and 6.03 × 10-4 mA M-1 (PAMN). This study pioneers the exploration of two novel mussel-inspired polycatecholamines in biosensors, opening avenues for functional nanocoatings that could drive further advancements in this field.


Assuntos
Técnicas Biossensoriais , Técnicas Eletroquímicas , Ouro , Grafite , Indóis , Limite de Detecção , Nanopartículas Metálicas , Polímeros , Técnicas Biossensoriais/métodos , Indóis/química , Polímeros/química , Técnicas Eletroquímicas/métodos , Grafite/química , Ouro/química , Animais , Nanopartículas Metálicas/química , Mycobacterium tuberculosis , Bivalves/química , Nanocompostos/química , Eletrodos , Norepinefrina/análise
2.
Heliyon ; 10(4): e25969, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38390054

RESUMO

This study aims to develop an exact analytical solution for steady-state thermo-mechanical stress in a functionally graded (FG) thick-walled cylindrical vessel. The cylinder is subjected to combined rotational speed and internal pressures while the thermal load is with convective and radiative boundary conditions. The dimensionless governing equations and boundary conditions, represented as a quartic equation, are derived and solved using Ferrari's method. The temperature, displacement, and stress fields across the thick-walled cylindrical vessel are calculated by finding the roots of the quartic equation. In order to investigate the accuracy of the exact analytical solution, a numerical model is constructed based on a standard Galerkin discretization approach of the finite element method (FEM). The analytical solutions and the results obtained through FEM show a high level of agreement. Furthermore, the study analyzes the effects of material parameters on temperature, displacement, and stress fields. Displacement, temperature, and stress fields are presented in the form of dimensionless graphs along the radial direction. For the considered parametric studies, results revealed that parabolic grading is beneficial than conventional grading. This study reveals that for the thermal loading, the maximum temperature, displacement, and tangential stress decrease for the parabolic grading. A similar but lower value of temperature, displacement, and tangential stress is also observed in the case of thermomechanical loading. This study is expected to assist in the assessment of the reliability of load calculations and contribute to the overall durability of pressure vessels. The results obtained from this study can provide valuable insights into thermo-elasticity and the thermo-mechanical behavior of thick-walled cylindrical vessels and can aid in the design and optimization of such systems.

3.
Prog Biophys Mol Biol ; 186: 14-27, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38052326

RESUMO

Since ancient times, Tuberculosis (TB) has been a severe invasive illness that has been prevalent for thousands of years and is also known as "consumption" or phthisis. TB is the most common chronic lung bacterial illness in the world, killing over 2 million people each year, caused by Mycobacterium tuberculosis (MTB). As per the reports of WHO, in spite of technology advancements, the average rate of decline in global TB infections from 2000-2018 was only 1.6% per year, and the worldwide reduction in TB deaths was only 11%. In addition, COVID-19 pandemic has reversed years of global progress in tackling TB with fewer diagnosed cases. The majority of undiagnosed patients of TB are found in low- and middle-income countries where the GeneXpert MTB/RIF assay and sputum smear microscopy have been approved by the WHO as reference procedures for quickly detecting TB. Biosensors, like other cutting-edge technologies, have piqued researchers' interest since they offer a quick and accurate way to identify MTB. Modern integrated technologies allow for the rapid, low-cost, and highly precise detection of analytes in extremely little amounts of sample by biosensors. Here in this review, we outlined the severity of tuberculosis (TB) and the most recent developments in the biosensors sector, as well as their various kinds and benefits for TB detection. The review also emphasizes how widespread TB is and how it needs accurate diagnosis and effective treatment.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Humanos , Rifampina , Pandemias , Sensibilidade e Especificidade , Escarro/microbiologia , Tuberculose/diagnóstico , Tuberculose/epidemiologia
4.
Biosensors (Basel) ; 13(3)2023 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-36979554

RESUMO

Tuberculosis (TB) has been a devastating human illness for thousands of years. According to the WHO, around 10.4 million new cases of tuberculosis are identified every year, with 1.8 million deaths. To reduce these statistics and the mortality rate, an early and accurate TB diagnosis is essential. This study offers a highly sensitive and selective electrochemical biosensor for Mycobacterium tuberculosis (MTB) detection based on a ternary nanocomposite of reduced graphene oxide, polydopamine, and gold nanoparticles (rGO-PDA-AuNP). Avidin-biotin coupling was used to bind the MTB probe DNA onto the rGO-PDA-AuNP modified glassy carbon electrode (ssDNA/avidin/rGO-PDA-AuNP). UV-Visible, Raman, XRD, and TEM were used to evaluate the structural and morphological characteristics of rGO-PDA-AuNP. Furthermore, DNA immobilization is validated using FESEM and FT-IR techniques. The modified electrodes were electrochemically analyzed using cyclic voltammetry (CV) and linear sweep voltammetry (LSV), and the results indicate that the produced electrode can detect target DNA up to 0.1 × 10-7 mM with 2.12 × 10-3 mA µM-1 sensitivity and a response time of 5 s. The constructed genosensor displayed high sensitivity and stability, and it also provides a unique strategy for diagnosing MTB at an early stage. Furthermore, our rGO-PDA-AuNP/GCE-based electrochemical platform has broad potential for creating biosensor systems for detecting various infectious pathogens and therapeutically significant biomarkers.


Assuntos
Técnicas Biossensoriais , Grafite , Nanopartículas Metálicas , Mycobacterium tuberculosis , Nanocompostos , Humanos , Ouro/química , Avidina , Espectroscopia de Infravermelho com Transformada de Fourier , Nanopartículas Metálicas/química , Grafite/química , Eletrodos , Nanocompostos/química , Técnicas Eletroquímicas/métodos , Técnicas Biossensoriais/métodos
5.
Environ Res ; 227: 115684, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-36921790

RESUMO

Polydopamine (PDA) has established itself as a promising grafting and coating material, particularly for functional group-deprived electrochemically active nanomaterials such as graphene, MXene, CNT, metal nanoparticles, and so on, and has proven its extensive applicability in the design and development of electrochemical biosensor devices. However, polynorepinephrine (PNE), a sister compound of PDA, having additional -OH groups and greater coating uniformity and biocompatibility, has never been studied in the field of biosensors. Herein, we investigated PNE as a coating material for reduced graphene oxide (RGO) and gold nanoparticles (Au) in order to build an electrochemical genosensor for Mycobacterium tuberculosis (MTB) detection. Biotin-Avidin chemistry was used to covalently immobilize probe DNA (ssDNA) specific to MTB to the nanocomposite surface on glassy carbon electrode (GCE) in order to construct biosensing electrodes. The formation of RGO/PNE and RGO/PNE/Au nanocomposite as well as the immobilization of ssDNA onto the bioelectrodes are both corroborated by UV-Visible, Raman, and XRD studies with FE-SEM and HR-TEM analysis. The electrochemical studies performed using cyclic voltammetry (CV) and linear sweep voltammetry (LSV) showed the significant enhancement in charge transfer kinetics of RGO/PNE/GCE and RGO/PNE/Au/GCE electrode compared to GO/GCE electrode. The biosensing investigations performed using ssDNA/avidin/RGO/PNE/Au/GCE bioelectrode showed high sensitivity (2.3 × 10-3 mA µM-1), low detection limit (0.1 × 10-7 µM), broad detection range (0.1 × 10-2 to 0.1 × 10-7 µM) with good selectivity and low response time (5 s) of the developed sensor. In comparison to the analogous RGO/PDA/Au material system, RGO/PNE/Au demonstrated increased enzyme loading, improved electrochemical responsiveness, and superior biosensing performance.


Assuntos
Grafite , Nanopartículas Metálicas , Mycobacterium tuberculosis , Nanocompostos , Grafite/química , Ouro/química , Avidina , Técnicas Eletroquímicas , Nanopartículas Metálicas/química , Carbono/química , Nanocompostos/química
6.
Environ Res ; 221: 115317, 2023 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-36657597

RESUMO

Heavy metal ion (HMI) sensors are the most sought commercial devices for environmental monitoring and food analysis research due to serious health concerns associated with HMI overdosage. Herein, we developed an effective electrochemical sensor for simultaneous detection of four HMI (Cd2+, Pb2+, Fe2+, and Cu2+) using a ternary nanocomposite of reduced graphene oxide functionalized with polydopamine and alanine (ALA/pDA/rGO). Comprehensive spectroscopic and microscopic characterizations were performed to ensure the formation of the ternary nanocomposite. The developed nanocomposite on glassy carbon electrode (GCE) yields >2-fold higher current than GO/GCE electrode with excellent electrochemical stability and charge transfer rate. Using DPV, various chemical and electrochemical parameters, such as supporting electrolyte, buffer pH, metal deposition time, and potential, were optimized to achieve highly sensitive detection of targeted HMI. For Cd2+, Pb2+, Fe2+, and Cu2+ sensing devised sensor exhibited detection limits of 1.46, 2.86, 50.23, and 17.95 ppb and sensitivity of 0.0929, 0.0744, 0.0051, and 0.0394 µA/ppb, respectively, with <6% interference. The sensor worked similarly well for real water samples with HMI. This study demonstrates a novel strategy for concurrently detecting and quantifying multiple HMI in water and soil using a smart ternary nanocomposite-based electrochemical sensor, which can also detect HMI in food samples.


Assuntos
Cádmio , Nanocompostos , Cádmio/análise , Chumbo , Óxidos/química , Técnicas Eletroquímicas/métodos , Carbono/química , Água , Nanocompostos/química
7.
Curr Opin Biomed Eng ; 24: 100408, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36033159

RESUMO

Antibacterial properties of copper have been known for ages. With the rise of antimicrobial resistance (AMR), hospital-acquired infections, and the current SARS-CoV-2 pandemic, copper and copper-derived materials are being widely researched for healthcare ranging from therapeutics to advanced wound dressing to medical devices. We cover current research that highlights the potential uses of metallic and ionic copper, copper alloys, copper nanostructures, and copper composites as antibacterial, antifungal, and antiviral agents, including those against the SARS-CoV-2 virus. The applications of copper-enabled engineered materials in medical devices, wound dressings, personal protective equipment, and self-cleaning surfaces are discussed. We emphasize the potential of copper and copper-derived materials in combating AMR and efficiently reducing infections in clinical settings.

8.
Mymensingh Med J ; 31(2): 295-303, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35383741

RESUMO

Acute bronchiolitis is a viral respiratory illness of infants and young children that occurs in the first two years of life. It is a major cause of hospital admissions in Bangladesh. Management of bronchiolitis is a great challenge for the pediatrician both in the outpatient and inpatient department. Because mainstay of treatment options are usually supportive like cool humidified oxygen, fluids, bronchodilators, epinephrine and corticosteroids. A number of agents have been proposed as adjunctive therapies, but their effects are controversial. Nebulized hypertonic saline (3%) has been reported to have some benefit in recent studies. So the objective of this study was to compare the efficacy of nebulized 3% hypertonic saline (HS) with salbutamol and normal saline (0.9%) nebulization in children with acute bronchiolitis. A double-blind randomized controlled trial was conducted in the Department of Paediatrics, Mymensingh Medical College Hospital, Bangladesh from November 2015 to October 2016. A total of 100 children aged one month to two years with acute bronchiolitis admitted in the Pediatric wards of MMCH were included in the study and were randomly assigned to either 3% nebulized hypertonic saline (n=50) or to 0.9% nebulized isotonic saline with salbutamol solution (n=50). The main outcome variables were clinical severity score, length of hospital stay, duration of oxygen therapy and oxygen saturation (SpO2). The therapy was repeated three times on every hospitalization day and the outcome was evaluated two times daily (12 hourly) for 60 hours. Mean duration of oxygen therapy in study group was 33.6±21.7 hours and in control group was 36.8±22.5 hours. But their difference was not statistically significant (p>0.05). The mean clinical severity score and mean oxygen saturation of the entire study patients in both groups decreased and increased respectively during hospital stay. There was significant difference of mean clinical severity score and oxygen saturation between admission and follow up-5 in each group (p<0.001). But their difference between two groups was not statistically significant (p>0.05). Mean duration of hospital stay was 2.91±1.54 days in study group and 3.09±1.85 days in control group. But their difference between two groups was not statistically significant (p>0.05). So in acute bronchiolitis nebulized hypertonic saline (3%) is as effective as normal saline (0.9%) and salbutamol nebulization.


Assuntos
Bronquiolite , Solução Salina , Doença Aguda , Albuterol/uso terapêutico , Bronquiolite/tratamento farmacológico , Broncodilatadores/uso terapêutico , Criança , Pré-Escolar , Método Duplo-Cego , Humanos , Lactente , Nebulizadores e Vaporizadores , Solução Salina/uso terapêutico , Índice de Gravidade de Doença , Centros de Atenção Terciária , Resultado do Tratamento
9.
Mymensingh Med J ; 31(2): 312-317, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35383743

RESUMO

Chronic abnormal uterine bleeding (AUB) is common, but there is a lack of standardized methods for investigating and etiological categorization of AUB. The PALM-COEIN classification system of AUB is getting important to overcome this issue. This cross-sectional study was conducted from January 2019 to December 2019 at Mymensingh Medical College Hospital, Mymensingh, Bangladesh, to determine the causes of AUB in women of the reproductive age group and categorize the causes of AUB as per the PALM-COEIN classification. A total of 380 women with chronic AUB were evaluated. The distribution of PALM-COEIN causes of AUB were AUB-P (1.8%), AUB-A (9.2%), AUB-L (13.2%), AUB-M (5.8%), AUB-C (1.1%), AUB-O (24.7%), AUB-E (1.6%), AUB-I (6.6%), and AUB-N (36.1%). The participants' mean age was 29.6 (±10.5) years, the majority (78.2%) of them was married, only a few (9.5%) had comorbid diseases, including hypertension (HTN) (1.1%), diabetes mellitus (DM) (5.3%), and hypothyroidism (8.7%). Women in the AUB-M classification had higher age than others; anemia was more prevalent in the AUB-P group, the AUB-O group had the highest TSH levels and hypothyroidism frequency. The PALM-COEIN classification helps ascertain the cause of AUB practically and should be used in routine clinical practices to manage these patients better.


Assuntos
Doenças Uterinas , Hemorragia Uterina , Adulto , Bangladesh/epidemiologia , Estudos Transversais , Feminino , Humanos , Hemorragia Uterina/etiologia
10.
Mymensingh Med J ; 31(2): 379-384, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35383754

RESUMO

A good number of patients experience post-Covid complications. Doctors and nurses are the front liners who are at greater risk of having this disease. Neurological symptoms are frequent in patients with post-COVID-19 infection. The study aims to observe the post-acute neurological symptoms among doctors and nurses of Mymensingh Medical College Hospital, a tertiary care hospital in Bangladesh, after they recover from initial infection or among the asymptomatic cases. It was a retrospective observational study among the doctors and nurses who became RT PCR positive from late April to mid-September 2020. A total of 100 subjects were interviewed over the phone for the presence or absence of neurological symptoms four weeks post Covid-19 infection. Total 54 doctors and 46 nurses were evaluated; the male-female ratio was 1:1.77, the mean age was 35.6±7.6 years. Post-acute COVID neurological symptoms (PACNS) were present in 60% of respondents. Fatigue (51%) was the most common symptom, followed by sleep disturbance, headache, myalgia, loss of taste and smell. PACNS were more in symptomatic patients at the initial Covid infection than asymptomatic cases.


Assuntos
COVID-19 , Adulto , Bangladesh/epidemiologia , COVID-19/complicações , COVID-19/epidemiologia , Feminino , Cefaleia/diagnóstico , Humanos , Masculino , SARS-CoV-2 , Centros de Atenção Terciária
11.
Curr Med Chem ; 29(37): 5815-5849, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34961455

RESUMO

Current advances in constructing functional nanomaterials and elegantly designed nanostructures have opened up new possibilities for the fabrication of viable field biosensors. Two-dimensional materials (2DMs) have fascinated much attention due to their chemical, optical, physicochemical, and electronic properties. They are ultrathin nanomaterials with unique properties such as high surface-to-volume ratio, surface charge, shape, high anisotropy, and adjustable chemical functionality. 2DMs such as graphene-based 2D materials, Silicate clays, layered double hydroxides (LDHs), MXenes, transition metal dichalcogenides (TMDs), and transition metal oxides (TMOs) offer intensified physicochemical and biological functionality and have proven to be very promising candidates for biological applications and technologies. 2DMs have a multivalent structure that can easily bind to single-stranded DNA/RNA (aptamers) through covalent, non-covalent, hydrogen bond, and π-stacking interactions, whereas aptamers have a small size, excellent chemical stability, and low immunogenicity with high affinity and specificity. This review discussed the potential of various 2D material-based aptasensor for diagnostic applications, e.g., protein detection, environmental monitoring, pathogens detection, etc.


Assuntos
Técnicas Biossensoriais , Grafite , Nanoestruturas , Técnicas Biossensoriais/métodos , Argila , DNA de Cadeia Simples , Grafite/química , Humanos , Nanoestruturas/química , Oligonucleotídeos , Óxidos/química , RNA , Silicatos
12.
J Geod ; 95(6): 65, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34720449

RESUMO

We measured the components of the 31-m-long vector between the two very-long-baseline interferometry (VLBI) antennas at the Kokee Park Geophysical Observatory (KPGO), Hawaii, with approximately 1 mm precision using phase delay observables from dedicated VLBI observations in 2016 and 2018. The two KPGO antennas are the 20 m legacy VLBI antenna and the 12 m VLBI Global Observing System (VGOS) antenna. Independent estimates of the vector between the two antennas were obtained by the National Geodetic Survey (NGS) using standard optical surveys in 2015 and 2018. The uncertainties of the latter survey were 0.3 and 0.7 mm in the horizontal and vertical components of the baseline, respectively. We applied corrections to the measured positions for the varying thermal deformation of the antennas on the different days of the VLBI and survey measurements, which can amount to 1 mm, bringing all results to a common reference temperature. The difference between the VLBI and survey results are 0.2 ± 0.4 mm, -1.3 ± 0.4 mm, and 0.8 ± 0.8 mm in the East, North, and Up topocentric components, respectively. We also estimate that the Up component of the baseline may suffer from systematic errors due to gravitational deformation and uncalibrated instrumental delay variations at the 20 m antenna that may reach ± 10 and -2 mm, respectively, resulting in an accuracy uncertainty on the order of 10 mm for the relative heights of the antennas. Furthermore, possible tilting of the 12 m antenna increases the uncertainties in the differences in the horizontal components to 1.0 mm. These results bring into focus the importance of (1) correcting to a common reference temperature the measurements of the reference points of all geodetic instruments within a site, (2) obtaining measurements of the gravitational deformation of all antennas, and (3) monitoring local motions of the geodetic instruments. These results have significant implications for the accuracy of global reference frames that require accurate local ties between geodetic instruments, such as the International Terrestrial Reference Frame (ITRF).

13.
J Appl Microbiol ; 131(5): 2539-2551, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33788359

RESUMO

AIMS: To determine the occurrence, diversity, antibiotic resistance and biofilm formation of Vibrio parahaemolyticus isolated from marine fishes in Bangladesh. METHODS AND RESULTS: A total of 80 marine fishes were obtained from the local markets and examined for the presence of V. parahaemolyticus. All the isolated V. parahaemolyticus were characterized for the presence of virulence markers, thermostable direct hemolysin (TDH) or thermostable direct hemolysin related hemolysin (TRH). Isolates were serotyped and further characterized by enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR) typing to analyse the genetic diversity. Moreover, biofilm formation and antibiotic resistance patterns were also determined. About 63·75% (51/80) of the tested marine fishes were contaminated with V. parahaemolyticus. From the contaminated fishes, 71 representatives V. parahaemolyticus were isolated and none of them harboured tdh and trh virulence genes. Nine different O-groups and seven different K-types were found by serological analysis and the dominant serotype was O5:KUT. In ERIC-PCR analysis, eight clusters (A-H) were found and the most common pattern was A (46·5%). All of the isolates were resistant to ampicillin and 78·9% of isolates were resistant to streptomycin. The highest biofilm formation was found at 37°C compared to 25°C and 4°C. CONCLUSION: Diverse V. parahaemolyticus are present in marine fishes in the local market of Bangladesh with antibiotic-resistant properties and biofilm formation capacity. SIGNIFICANCE AND IMPACT OF THE STUDY: The widespread prevalence of diverse V. parahaemolyticus in marine fishes is an issue of serious concern, and it entails careful monitoring to ascertain the safety of seafood consumers.


Assuntos
Vibrioses , Vibrio parahaemolyticus , Animais , Bangladesh , Peixes , Proteínas Hemolisinas/genética , Alimentos Marinhos , Vibrioses/veterinária , Vibrio parahaemolyticus/genética , Virulência/genética
14.
RSC Adv ; 11(21): 12507-12519, 2021 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35423807

RESUMO

Dextran mediated MnFe2O4/ZnS opto-magnetic nanocomposites with different concentrations of ZnS were competently synthesized adopting the co-precipitation method. The structural, morphological, magnetic, and optical properties of the nanocomposites were exhaustively characterized by XRD, HRTEM, FTIR, VSM techniques, and PL spectroscopy. XRD spectra demonstrate the existence of the cubic spinel phase of MnFe2O4 and the cubic zinc blend phase of ZnS in the nanocomposites. HRTEM images show the average crystallite size ranges of 15-21 nm for MnFe2O4 and 14-45 nm for ZnS. Investigation of the FTIR spectra reveals the incorporation of ZnS nanoparticles on the surface of MnFe2O4 nanoparticles by dint of biocompatible surfactant dextran. The nanocomposites exhibit both magnetic and photoluminescence properties. Photoluminescence analysis confirmed the redshift of the emission peaks owing to the trap states in the ZnS nanocrystals. The room temperature VSM analysis shows that the saturation magnetization and coercivity of MnFe2O4 nanoparticles initially increase then decrease with the increasing concentration of ZnS in the nanocomposite. The induction heating analysis shows that the presence of dextran enhances the self heating properties of the MnFe2O4/ZnS nanocomposites which can also be controlled by tailoring the concentration of the ZnS nanoparticles. These suggest that MnFe2O4/Dex/ZnS is a decent candidate for hyperthermia applications.

15.
J Tissue Eng Regen Med ; 14(12): 1763-1778, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32931632

RESUMO

Bioengineered scaffolds derived from the decellularized extracellular matrix (ECM) obtained from discarded animal organs and tissues are attractive candidates for regenerative medicine applications. Tailoring these scaffolds with stem cells enhances their regeneration potential making them a suitable platform for regenerating damaged tissues. Thus, the study was designed to investigate the potential of mesenchymal stem cells tailored acellular bubaline diaphragm and aortic ECM for the repair of full-thickness abdominal wall defects in a rabbit model. Tissues obtained from bubaline diaphragm and aorta were decellularized and bioengineered by seeding with rabbit bone marrow derived mesenchymal stem cells (r-BMSC). Full-thickness abdominal wall defects of 3 cm × 4 cm size were created in a rabbit model and repaired using five different prostheses, namely, polypropylene sheet, nonseeded diaphragm ECM, nonseeded aorta ECM, r-BMSC bioengineered diaphragm ECM, and r-BMSC bioengineered aorta ECM. Results from the study revealed that biological scaffolds are superior in comparison to synthetic polymer mesh for regeneration in terms of collagen deposition, maturation, neovascularization, and lack of any significant (P > 0.05) adhesions with the abdominal viscera. Seeding with r-BMSC significantly increased (P < 0.05) the collagen deposition and biomechanical strength of the scaffolds. The bioengineered r-BMSC seeded acellular bubaline diaphragm showed even superior biomechanical strength as compared to synthetic polymer mesh. Tailoring of the scaffolds with the r-BMSC also resulted in significant reduction (P < 0.01) in antibody and cell mediated immune reactions to the xenogeneic scaffolds in rabbit model.


Assuntos
Parede Abdominal/patologia , Aorta/fisiologia , Bioengenharia , Diafragma/fisiologia , Células-Tronco Mesenquimais/citologia , Regeneração/fisiologia , Alicerces Teciduais/química , Adipogenia , Animais , Fenômenos Biomecânicos , Búfalos , Bovinos , Linhagem da Célula , Condrogênese , Colágeno/metabolismo , DNA/metabolismo , Matriz Extracelular/metabolismo , Implantes Experimentais , Osteogênese , Coelhos , Dodecilsulfato de Sódio , Aderências Teciduais/patologia , Água
16.
Sci Rep ; 10(1): 9913, 2020 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-32555266

RESUMO

Lightweight, porous, high-performance electromagnetic interference (EMI) shielding and fire-resistant materials are highly demanded in aerospace and defense applications. Due to the lightweight, open porosity and high surface area, carbon foam has been considered as one of the most promising candidates for EMI shielding applications. In the present investigation, we demonstrate the development of novel carbon-red mud hybrid foams with excellent EMI shielding effectiveness (SE). The carbon-red mud hybrid foams are prepared using phenolic resin as a carbon source and red mud (industrial waste) as filler. We observed that the inclusion of red mud in carbon-red mud hybrid foams significantly enhances their dielectric, magnetic, EMI shielding and thermal properties. The EMI shielding results show that absorption is the main contributor to the total EMI SE. The maximum total EMI shielding effectiveness is achieved to be 51.4 dB in the frequency range of 8.2-12.4 GHz for carbon-red mud hybrid foam having 20 wt. % of red mud. The CF-RM20 also showed excellent fire resistance and high thermal stability at elevated temperatures.

18.
Mater Sci Eng C Mater Biol Appl ; 109: 110600, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32228994

RESUMO

Ti2Co alloy (with and without Al) foam of varying densities were prepared through space holder technique, in which space holder varied from 40 to 70 vol% and Al-concentration varied from 0 to 6 wt% with an enhancement of 2 wt%. The prepared foam samples were analysed in terms of microstructure, phase analysis and mechanical properties. The sizes of pores in the foams come to be almost similar to that of space holder. An increase in the amount of Al resulted in enhancement of the mechanical properties such as comprehensive strength, plateau stress, energy absorption capacity, hardness and Young's modulus due to increase in solid solution strengthening and variation in morphology of eutectoid phase. Also, these values are found to be predictable with the generalized relation through adjustment of the fraction of materials at cell edges and cell walls. The openness of the investigated foams was calculated to obtain degree of openness. The corrosion rate was calculated for each sample of Ti2Co alloys foams and compared with the reported values. The microstructure and mechanical properties of the prepared foams were also compared with that of the human bone.


Assuntos
Ligas/química , Alumínio/química , Osso e Ossos , Cobalto/química , Alicerces Teciduais/química , Titânio/química , Módulo de Elasticidade , Humanos , Teste de Materiais
19.
Materials (Basel) ; 13(3)2020 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-32046361

RESUMO

The present work was addressed to the closed-cell aluminum (Al)-silicon carbide (SiC) particles (15 wt.%) with graphene (0.5 wt.%) reinforced hybrid composite foam, which was produced through the melt route process. Under the strain rates ranging from 500 s-1 to 2760 s-1, the compression deformation behavior of hybrid composite foam was executed. The compression results disclosed that plateau stress along with energy absorption of produced hybrid composite foam are heightened with strain rates and is also discovered to be responsive to the relative density under the confront domain of experiments. Analysis of Variance was deployed for optimizing parameters such as strain rates, mass, density, relative density, and pore size. Furthermore, the contribution of each optimized parameters on plateau stress and energy absorption were observed.

20.
Res Vet Sci ; 125: 360-369, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31376718

RESUMO

Alpha-tocopherol-selenium (ATS) and ascorbic acid (AA) are the potent antioxidants. The present study investigated whether supplementation of ATS and AA in periparturient sows has positive effects on amelioration of oxidative stress, serum immunoglobulin G (IgG), lipid profile and sows performance. For this, twenty-four pregnant multiparous sows (landrace×indigenous) were randomly distributed into four groups (6 sows per group) 20 days before expected date of farrowing as Control (basal diet); ATS (basal diet + ATS); AA (basal diet + AA) and ATS-AA (basal diet + ATS plus AA). The results of the study revealed that the concentrations of triglyceride and cholesterol significantly reduced from day -7 to day 7 of farrowing irrespective of supplementations to sows, but the leptin concentration significantly reduced on day 7 of farrowing in ATS-AA supplemented sows (p<0.05). Moreover, sows of supplemented groups experienced decreased oxidative stress and cortisol level than control sows. The serum IgG concentration was significantly increased on day 7 post-farrowing in ATS group but it was much earlier on day 2 of farrowing in ATS-AA group (p<0.001). Supplementing sows with ATS and/or AA did not influence significantly the birth weight, weaning weight and litter size at weaning (p>0.05). Although piglet survival rate was not affected significantly by supplementation, however, piglet mortality rate was lowest in ATS-AA than any other groups. It was concluded that supplementation of ATS and/or AA to sows during late gestating and early lactating period ameliorated oxidative stress, improved lipid profile and serum IgG level without influencing reproductive performance.


Assuntos
Ácido Ascórbico/metabolismo , Metabolismo dos Lipídeos , Estresse Oxidativo , Selênio/metabolismo , Sus scrofa/fisiologia , alfa-Tocoferol/metabolismo , Ração Animal/análise , Animais , Animais Recém-Nascidos/fisiologia , Ácido Ascórbico/administração & dosagem , Contagem de Células Sanguíneas/veterinária , Peso Corporal , Dieta/veterinária , Suplementos Nutricionais/análise , Feminino , Lactação , Leptina/metabolismo , Tamanho da Ninhada de Vivíparos , Longevidade , Gravidez , Selênio/administração & dosagem , alfa-Tocoferol/administração & dosagem
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