Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 51
Filtrar
1.
Int J Hyperthermia ; 41(1): 2349080, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38705588

RESUMO

OBJECTIVES: To investigate image-guided volumetric hyperthermia strategies using the ExAblate Body MR-guided focused ultrasound ablation system, involving mechanical transducer movement and sector-vortex beamforming. MATERIALS AND METHODS: Acoustic and thermal simulations were performed to investigate volumetric hyperthermia using mechanical transducer movement combined with sector-vortex beamforming, specifically for the ExAblate Body transducer. The system control in the ExAblate Body system was modified to achieve fast transducer movement and MR thermometry-based hyperthermia control, mechanical transducer movements and electronic sector-vortex beamforming were combined to optimize hyperthermia delivery. The experimental validation was performed using a tissue-mimicking phantom. RESULTS: The developed simulation framework allowed for a parametric study with varying numbers of heating spots, sonication durations, and transducer movement times to evaluate the hyperthermia characteristics for mechanical transducer movement and sector-vortex beamforming. Hyperthermic patterns involving 2-4 sequential focal spots were analyzed. To demonstrate the feasibility of volumetric hyperthermia in the system, a tissue-mimicking phantom was sonicated with two distinct spots through mechanical transducer movement and sector-vortex beamforming. During hyperthermia, the average values of Tmax, T10, Tavg, T90, and Tmin over 200 s were measured within a circular ROI with a diameter of 10 pixels. These values were found to be 8.6, 7.9, 6.6, 5.2, and 4.5 °C, respectively, compared to the baseline temperature. CONCLUSIONS: This study demonstrated the volumetric hyperthermia capabilities of the ExAblate Body system. The simulation framework developed in this study allowed for the evaluation of hyperthermia characteristics that could be implemented with the ExAblate MRgFUS system.


Assuntos
Hipertermia Induzida , Imageamento por Ressonância Magnética , Humanos , Hipertermia Induzida/métodos , Imageamento por Ressonância Magnética/métodos , Ablação por Ultrassom Focalizado de Alta Intensidade/métodos , Imagens de Fantasmas
2.
Crit Rev Food Sci Nutr ; 63(24): 6960-6982, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35142568

RESUMO

Microwave-assisted extraction (MAE) is a sustainable non-contact heating source and has been extensively researched for extraction of plant bioactives. There are various derivatives or modules available for MAE and solvent free microwave extraction (SFME) is one of them where by operational aspects of MAE have been maneuvered to make it compatible for extraction of essential oil (EO). This article makes an attempt to overhaul the science of distillation by revisiting SFME and trying to learn through a comprehensive tutelage comprising of 20 years of published literature in Web of Science so that a shrewd decision can be obtained through a cross talk based critical analysis on the science SFME. A total of 312 articles within the time frame of 2001-2020 were extracted from WOS and critically analyzed. Considering the various uncertainties involved with SFME the articles establishes some global working standards and tries to explore the dynamic relationship between plant part/genus and microwave power, microwave power and time, microwave power and extracted volatile principles, prioritizes plant family selection and also presents a research blueprint of SFME. A techno-commercial feasibility study has been presented for smooth industrial transition of SFME. The tutelage presented decodes the publication trends and SFME blueprint.


Assuntos
Óleos Voláteis , Óleos Voláteis/análise , Destilação , Micro-Ondas , Extratos Vegetais , Reações Cruzadas
3.
Macromol Rapid Commun ; 44(2): e2200628, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36239163

RESUMO

Nanofibrillated cellulose (NFC) and polymethylsilsesquioxane (PMSQ) based aerogel are prepared by the sol-gel method. The objective of this work is to study the impact of surfactant and base catalyst on the thermal and mechanical performance of the corresponding aerogel. The rheological premonitory assists in predicting the bulk properties of the aerogel. The chemical structure of the aerogel is studied by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and solid-state nuclear magnetic resonance (NMR). X-ray microtomographic (XMT) analysis confirms the homogeneous and monolithic structure of the aerogel. The lowest thermal conductivity is achieved as 23.21 mW m-1 K-1 with V-0 and HBF rating through UL-94 test. Thermal performance of aerogels is cross-verified through modeling and simulation in COMSOL multiphysics platform. The mechanical properties of aerogel are evaluated by monolithic compression test in axial and radial compression test up to 90% strain, cyclic compression loading-unloading, and reloading test, flexural test, and dynamic mechanical analysis. The time-temperature analysis has shown around 5 °C temperature difference in the middle of the room after using the aerogel panel at the exposed surface, which assists in the practical application of the synthesized aerogel panel.


Assuntos
Celulose , Compostos de Organossilício , Celulose/química , Tensoativos , Polímeros
4.
Mol Biol Rep ; 49(8): 7887-7898, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35637316

RESUMO

BACKGROUND: Disease-specific human induced pluripotent stem cells (hiPSCs) can be generated directly from individuals with known disease characteristics or alternatively be modified using genome editing approaches to introduce disease causing genetic mutations to study the biological response of those mutations. The genome editing procedure in hiPSCs is still inefficient, particularly when it comes to homology directed repair (HDR) of genetic mutations or targeted transgene insertion in the genome and single cell cloning of edited cells. In addition, genome editing processes also involve additional cellular stresses such as poor cell viability and genetic stability of hiPSCs. Therefore, efficient workflows are desired to increase genome editing application to hiPSC disease models and therapeutic applications. METHODS AND RESULTS: To this end, we demonstrate an efficient workflow for feeder-free single cell clone generation and expansion in both CRISPR-mediated knock-out (KO) and knock-in (KI) hiPSC lines. Using StemFlex medium and CloneR supplement in conjunction with Matrigel cell culture matrix, we show that cell viability and expansion during single-cell cloning in edited and unedited cells is significantly enhanced. Keeping all factors into account, we have successfully achieved hiPSC single-cell survival and cloning in both edited and unedited cells with rates as maximum as 70% in less than 2 weeks. CONCLUSION: This simplified and efficient workflow will allow for a new level of sophistication in generating hiPSC-based disease models to promote rapid advancement in basic research and also the development of novel cellular therapeutics.


Assuntos
Células-Tronco Pluripotentes Induzidas , Sistemas CRISPR-Cas/genética , Clonagem Molecular , Edição de Genes/métodos , Genoma Humano , Humanos
5.
Nutr Cancer ; 73(2): 300-306, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32242459

RESUMO

Anti-proliferative and apoptotic activities of different concentrations (10-50 µg/ml) of total lipid of the freshwater fish, Labeo rohita against human prostate cancer cells (PC3) were assessed using cells viability analysis by MTT assay, intracellular ROS generation and nuclear condensation. The cell cycle analysis for DNA content was performed by flow cytometry. The fish lipid was found to be effective which changed the characteristic morphology of PC3cells and also decreased their cells number. The fish lipid significantly induced the cell cycle arrest and level of ROS which caused apoptosis in PC3cells. The anti-proliferative and apoptotic roles of the fish lipid against the cells of prostate cancer may be helpful for the prevention and development of anticancer drug.


Assuntos
Apoptose , Neoplasias da Próstata , Animais , Ciclo Celular , Pontos de Checagem do Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Lipídeos , Masculino , Neoplasias da Próstata/tratamento farmacológico , Espécies Reativas de Oxigênio
6.
Environ Toxicol ; 36(1): 5-15, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32794641

RESUMO

Osteoarthritis (OA) is a chronic degenerative and musculoskeletal disorder. The toxicity associated with nonsteroidal antiinflammatory drugs (NSAIDs) limits its use in the management of OA. To ameliorate these toxicities, natural antioxidants can be used as substitutes for the management of OA. Therefore, this study is aimed to investigate the prophylactic mechanisms of Punica granatum L. peel (PGP) in collagenase-induced OA rat compared with indomethacin. OA was induced in female Sprague Dawley rats by intraarticular injection of collagenase type-II and treated with PGP (250 and 500 mg/kg body wt) and a positive control (PC) indomethacin (3 mg/kg body wt). The results demonstrated that PGP reduced the collagenase induced OA as compared with indomethacin treated group through reducing blood ALP (P < .001) and significantly (P < .001) inhibited cartilage erosion as indicated in histological slides with retention of collagen and proteoglycan content. Quantitative real-time PCR analysis revealed the considerable (P < .05) upregulation in the expression of COL-2 gene and downregulation of MMP-3 and COX-2 genes in the PGP treated group. The high phenolic content (633 ± 1.16 mg/GAE) and flavonoid content (420.3 ± 2.14 mg/RE) contribute to the strong antioxidant activity with IC50 value (320 ± 2.2 µg/mL) of DPPH free radical scavenging activity. These results need further validation in clinical studies and thus, PGP could be developed as a preventive drug treatment for OA.

7.
Cancer Metastasis Rev ; 37(4): 791-804, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30284650

RESUMO

Brain metastasis is one of the leading causes of death among cancer patients. Cancer cells migrate to various sites and harbor different niche in the body which help cancer cells in their survival. The brain is one of the safest place where cancer cells are protected from immune cells. Breast, lung, and melanoma cancer cells have high propensity to migrate towards the brain. To enter the brain, cancer cells have to cross the blood brain barrier. Survival and finding new niche in the brain are directed by several mechanisms in which different cellular players take part such as astrocytes, microglia, Schwann cells, satellite cells, oligodendrocytes, and ependymal cells. Usually, cancer cells highjack the machinery of brain cellular players to survive in the brain environment. It has been shown that co-culture of M2 macrophage with cancer cells leads to increased proliferation and survival of cancer cells. One of the challenges of understanding brain metastasis is appropriate model system to understand dynamic interaction of cancer cells and brain cellular players. To meet this challenge, microfluidic-based devices are employed which can mimic the dynamic conditions as well as can be used for culturing human cells for personalized therapy. In this review, we have systematically reviewed the current status of the role of cellular players in brain metastasis along with explaining how translational approach of microfluidics can be employed for finding new drug target as well as biomarker for brain metastasis. Finally, we have also commented on the mechanism of action of drugs against brain metastasis.


Assuntos
Neoplasias Encefálicas/secundário , Encéfalo/patologia , Animais , Barreira Hematoencefálica/patologia , Neoplasias Encefálicas/patologia , Progressão da Doença , Humanos
8.
Int J Hyperthermia ; 35(1): 419-434, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30307345

RESUMO

The present work is concerned with the numerical investigation of the thermal response of tissue-mimicking biological phantom(s) subjected to high intensity focused ultrasound (HIFU). Simulations have been performed on the 3-dimensional physical domain for two-layered as well as multi-layered medium consisting of water and liver tissue. Local pressure distribution within the body of the phantom has been calculated by solving the complete full-wave nonlinear form of Westervelt equation. The solution of the pressure wave equation has been coupled with Pennes bioheat transfer equation to determine the full field temperature distribution. Results in the form of pressure fields, temperature distributions and the corresponding thermal dosage in the targeted region of the tissue domain have been presented. Magnitudes of the maximum pressure (and hence the resultant temperature levels) in the focal region as obtained using the nonlinear form of Westervelt equation are found to be significantly higher than that determined based on the linear form of the equation. Compared to water, wherein the acoustic intensity is maximum, the addition of sub-layers of skin, fat, and muscle into water resulted in the reduction of the peak intensity and also shifted the intensity profiles along the direction of propagation of the acoustic waves. However, addition of liver tissue into water led to the shifting of intensity profile in the opposite direction i.e., towards the transducer. The results further reveal that due to the dependence of attenuation coefficient on the source frequency, the temperature at the focal region increases with an increase in the transducer frequency. The work is further extended from single lesion to multiple lesion generation through controlled movement of the transducer and the resultant transient full field temperature distribution has been presented. The concerned observations highlight the need of optimizing the thermal energy for each lesion, the inter spatial distance between different lesions and the delay time so as to ensure minimal thermal damage to the surrounding healthy cells as well as to reduce the total treatment duration.


Assuntos
Ablação por Ultrassom Focalizado de Alta Intensidade/métodos , Modelos Biológicos , Humanos , Temperatura
9.
J Nanosci Nanotechnol ; 18(2): 902-912, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29448514

RESUMO

Facile one pot synthesis of graphene oxide (GO) by sonication assisted mechanochemical approach has been reported here. The amalgamation of ultrasonication and mechanical stirring has assisted the synthesis of GO in a short time duration of only 4 hours with good reaction yield. The structural characterization of GO was performed by X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), UV-Visible spectroscopy and Raman spectroscopy. Atomic force microscopic (AFM) analysis manifested the flake like morphology of GO with average sheet thickness ~1.5 nm. AFM also provides important information about the surface roughness. Transmission electron microscope (TEM) analysis gave clear visualization of well exfoliated structure of GO in the form of thin flakes. The field emission scanning electron microscope (FESEM) analysis revealed a crimpling surface morphology of GO. The average size of GO flake as revealed through various morphological as well as light scattering techniques was around 3 µm. Moreover, important surface chemistry of the synthesized GO was well ascertained through contact angle analysis, AFM analysis and zeta potential analysis.

10.
J Environ Manage ; 226: 448-456, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30144783

RESUMO

The study endeavors the anaerobic treatment of cyanide-containing effluents using the hybrid anaerobic reactor, with self-immobilized granules under high up-flow velocities. Comparison of one-year time-course analyses of HARs treating high strength effluents containing cyanide and control indicates the importance of wastewater characteristics in development and maintenance of microbiome. Efforts were directed towards associating process performance with microbial dynamics. Presence of cyanide results in the accumulation of intermediates paralleled with a drop in abundance of sensitive aceticlastic methanogens. HAR appear to have better resilience than other identified digesters because of shielding effects and enhanced granule-wastewater contact. The predominance of Methanobacteriales in the presence of cyanide can be linked to its tolerance. It was found that methane yield is positively correlated with abundance of aceticlastic guilds (R = 0.830, CI = 0.01). Tolerant bacterial groups were also identified. The study advances our knowledge related to less energy intensive technology with the focus on the development of efficient HAR.


Assuntos
Reatores Biológicos , Cianetos/isolamento & purificação , Anaerobiose , Cianetos/química , Metano , Esgotos , Águas Residuárias , Purificação da Água
13.
J Imaging Inform Med ; 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38528288

RESUMO

In this paper, a segmentation-based image fusion method is proposed for the fusion of MR and CT images to obtain a high contrast fused image that contains complementary information from both input images. The proposed method uses the fuzzy C-mean method to extract information about the skull from the CT image. This skull information is used to extract soft tissue information from the MR image. Both the skull information and the soft tissue information are then fused using the fusion rule. The efficiency of the proposed method over other state-of-the-art fusion methods is analyzed and compared using qualitative and quantitative analysis methods. Qualitative analysis shows the improvement in the contrast between the bone and the soft tissue using the proposed method over other state-of-the-art methods without introducing any artifacts or distortions. Classical and gradient-based quantitative analysis also show significant improvement in the fused image obtained using the proposed method over the five state-of-the-art methods. The percentage improvement in the standard deviation, average gradient, entropy, spatial frequency, QABF, and LABF of the proposed method over the best value obtained by the five state-of-the-art methods is 27.11%, 12.06%, 23.64%, 11.30%, 5.59%, and 13.70% respectively.

14.
J Biomol Struct Dyn ; 42(1): 261-273, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37061929

RESUMO

Sickle cell disease (SCD) is an autosomal recessive genetic disorder affecting millions of people worldwide. A reversible and selective DNMT1 inhibitor, GSK3482364, has been known to decrease the overall methylation activity of DNMT1, resulting in the increase of HbF levels and percentage of HbF-expressing erythrocytes in an in vitro and in vivo model. In this study, a structure-based virtual screening was done with GSK3685032, a co-crystalized ligand of DNMT1 (PDB ID: 6X9K) with an IC50 value of 0.036 µM and identified 3988 compounds from three databases (ChEMBL, PubChem and Drug Bank). Using this screening method, we identified around 15 compounds with XP docking scores greater than -8 kcal/mol. Further, prime MM-GBSA calculations have been performed and found compound SCHEMBL19716714 with the highest binding free energy of -83.31 kcal/mol. Finally, four compounds were identified based on glide energy and ΔG bind scores that have the most binding with DG7, DG19, DG20 bases and Lys1535, His1507, Trp1510, Ser1230, which were required for the target enzyme inhibition. Furthermore, molecular dynamics simulation studies of top ligands validate the stability of the docked complexes by examining root mean square deviations, root mean square fluctuations, solvent accessible surface area, and radius of gyration graphs from simulation trajectories. These findings suggest that the top four hit compounds may be capable of inhibiting DNMT1 and that additional in vitro and in vivo studies will be essential to prove the clinical effectiveness of the selected lead compounds.Communicated by Ramaswamy H. Sarma.


Assuntos
Anemia Falciforme , Simulação de Dinâmica Molecular , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica , Anemia Falciforme/tratamento farmacológico , Ligantes
15.
IEEE Open J Eng Med Biol ; 5: 362-375, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38899026

RESUMO

PURPOSE: To develop patient-specific 3D models using Finite-Difference Time-Domain (FDTD) simulations and pre-treatment planning tools for the selective thermal ablation of prostate cancer with interstitial ultrasound. This involves the integration with a FDA 510(k) cleared catheter-based ultrasound interstitial applicators and delivery system. METHODS: A 3D generalized "prostate" model was developed to generate temperature and thermal dose profiles for different applicator operating parameters and anticipated perfusion ranges. A priori planning, based upon these pre-calculated lethal thermal dose and iso-temperature clouds, was devised for iterative device selection and positioning. Full 3D patient-specific anatomic modeling of actual placement of single or multiple applicators to conformally ablate target regions can be applied, with optional integrated pilot-point temperature-based feedback control and urethral/rectum cooling. These numerical models were verified against previously reported ex-vivo experimental results obtained in soft tissues. RESULTS: For generic prostate tissue, 360 treatment schemes were simulated based on the number of transducers (1-4), applied power (8-20 W/cm2), heating time (5, 7.5, 10 min), and blood perfusion (0, 2.5, 5 kg/m3/s) using forward treatment modelling. Selectable ablation zones ranged from 0.8-3.0 cm and 0.8-5.3 cm in radial and axial directions, respectively. 3D patient-specific thermal treatment modeling for 12 Cases of T2/T3 prostate disease demonstrate applicability of workflow and technique for focal, quadrant and hemi-gland ablation. A temperature threshold (e.g., Tthres = 52 °C) at the treatment margin, emulating placement of invasive temperature sensing, can be applied for pilot-point feedback control to improve conformality of thermal ablation. Also, binary power control (e.g., Treg = 45 °C) can be applied which will regulate the applied power level to maintain the surrounding temperature to a safe limit or maximum threshold until the set heating time. CONCLUSIONS: Prostate-specific simulations of interstitial ultrasound applicators were used to generate a library of thermal-dose distributions to visually optimize and set applicator positioning and directivity during a priori treatment planning pre-procedure. Anatomic 3D forward treatment planning in patient-specific models, along with optional temperature-based feedback control, demonstrated single and multi-applicator implant strategies to effectively ablate focal disease while affording protection of normal tissues.

16.
J Neurosci Rural Pract ; 15(1): 95-102, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38476427

RESUMO

Objectives: Stereotactic biopsy (STB) is a potential diagnostic tool considering its minimal invasiveness, high diagnostic yield, and minimal associated complications. Over the years, various frame-based instrument systems and frameless stereotactic biopsy systems have emerged to be employed in clinical use. With this study, we intend to get more by doing less in the form of STB for the patients of doubtful intracranial lesions treated over the past 5 years. We also want to highlight the technique of performing the procedure under scalp block, which can be used as a versatile tool in many clinical scenarios. Stereotactic biopsies may be planned even in rural district-level health facilities. One-time investment to procure instruments and avail existing imaging can lead to establishing definitive diagnoses in many doubtful cases. This will result in lesser cost and early establishment of treatment. Independent risk factors determining the outcome, such as deep-seated lesions, associated edema, and intraoperative hypertension, were studied. Establishing the diagnosis helped in prognosticating the disease, explaining the natural progression of symptoms, and starting adjuvant therapy. This tissue biopsy would also help secure samples for research and molecular analysis. Materials and Methods: Twenty patients underwent STBs at our institution between January 2018 and December 2022. We retrospectively analyzed patient characteristics, tumor pathology, surgical procedures, and outcomes, including the diagnostic value and surgery-related complications. These patients were followed up, and their progression-free and overall survival were analyzed. The need for adjuvant treatment was noted and analyzed. All procedures were performed using Cosman Roberts Wells® stereotactic frame. Pre-procedure magnetic resonance scans were performed at the time of admission. Contrast-enhanced computerized tomography (CT) scan after frame application was performed to identify targets and calculate the coordinates. A post-procedure CT scan was done to confirm the accessibility of the targeted lesion. Results: The most common location of the tumor was a deep-seated thalamic lesion. A definitive diagnosis was established in 19 patients (95%) at the first STB. The diagnoses were glioma in 55% of cases, primary central nervous system lymphoma, tuberculosis, and demyelinating disorders in 10% of each, and a metastatic brain tumor in 1 (5%). The post-operative complications were all transient except in one patient with deterioration of motor weakness. The follow-up was noted, and modes of adjuvant treatment needed in these patients were recorded. Conclusion: Stereotactic biopsy is a useful and effective method for achieving a definitive diagnosis and aiding in treating multifocal or small deep-seated lesions in or around eloquent regions.

17.
Nat Commun ; 15(1): 1794, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38413594

RESUMO

Ex vivo cellular system that accurately replicates sickle cell disease and ß-thalassemia characteristics is a highly sought-after goal in the field of erythroid biology. In this study, we present the generation of erythroid progenitor lines with sickle cell disease and ß-thalassemia mutation using CRISPR/Cas9. The disease cellular models exhibit similar differentiation profiles, globin expression and proteome dynamics as patient-derived hematopoietic stem/progenitor cells. Additionally, these cellular models recapitulate pathological conditions associated with both the diseases. Hydroxyurea and pomalidomide treatment enhanced fetal hemoglobin levels. Notably, we introduce a therapeutic strategy for the above diseases by recapitulating the HPFH3 genotype, which reactivates fetal hemoglobin levels and rescues the disease phenotypes, thus making these lines a valuable platform for studying and developing new therapeutic strategies. Altogether, we demonstrate our disease cellular systems are physiologically relevant and could prove to be indispensable tools for disease modeling, drug screenings and cell and gene therapy-based applications.


Assuntos
Anemia Falciforme , Talassemia beta , Humanos , Talassemia beta/genética , Talassemia beta/terapia , Hemoglobina Fetal/genética , Hemoglobina Fetal/metabolismo , Anemia Falciforme/tratamento farmacológico , Anemia Falciforme/genética , Células-Tronco Hematopoéticas/metabolismo , Genótipo , Sistemas CRISPR-Cas
18.
iScience ; 27(6): 109918, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38812541

RESUMO

Malaria parasite invasion to host erythrocytes is mediated by multiple interactions between merozoite ligands and erythrocyte receptors that contribute toward the development of disease pathology. Here, we report a novel antigen Plasmodium prohibitin "PfPHB2" and identify its cognate partner "Hsp70A1A" in host erythrocyte that plays a crucial role in mediating host-parasite interaction during merozoite invasion. Using small interfering RNA (siRNA)- and glucosamine-6-phosphate riboswitch (glmS) ribozyme-mediated approach, we show that loss of Hsp70A1A in red blood cells (RBCs) or PfPHB2 in infected red blood cells (iRBCs), respectively, inhibit PfPHB2-Hsp70A1A interaction leading to invasion inhibition. Antibodies targeting PfPHB2 and monoclonal antibody therapeutics against Hsp70A1A efficiently block parasite invasion. Recombinant PfPHB2 binds to RBCs which is inhibited by anti-PfPHB2 antibody and monoclonal antibody against Hsp70A1A. The validation of PfPHB2 to serve as antigen is further supported by detection of anti-PfPHB2 antibody in patient sera. Overall, this study proposes PfPHB2 as vaccine candidate and highlights the use of monoclonal antibody therapeutics for future malaria treatment.

19.
J Phys Condens Matter ; 35(34)2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37216950

RESUMO

We report the structural and magnetic properties of Nd1-xCexCrO3(x=0.05-0.175) single-phase samples to classify the influence of Ce substitution on the Nd-site. The electron density profile indicates the possible covalent nature of Cr-O bonds. The x-ray photoelectron spectroscopy confirms a mixed Ce valency with a constant ratio of Ce3+/Ce4+ions in all substituted compounds and the charge neutralization through the oxygen vacancies. The magnetization measurements reveal an increase in antiferromagnetic ordering temperature (TN) and spin-reorientation transition temperature (TSR) and unfold soft spin-reorientation attributed to diluted superexchange interactions upon Ce incorporation. The presence of mixed Ce ions induces the merging of the hysteresis loop with a significant exchange bias (EB) field. We demonstrate for the first time that the magnitude of the magnetization is different for the same applied field in positive and negative directions, indicating the existence of two different magnetic states. The difference between these two magnetic states possibly arises from the pinning of Cr3+spins, which requires an additional Zeeman energy for it to rotate. This maximum Zeeman energy from the normalized magnetic susceptibility vs. temperature curves correlates with the maximum EB field, validating unusual EB in these compounds.

20.
Enzyme Microb Technol ; 170: 110292, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37536048

RESUMO

Biodiesel production from used cooking oil is sustainable alternative, for bio-energy production. The process generates residual crude glycerol (RCG) as the major energy-rich waste which can be used to produce various bio-based chemicals like 1,3-propanediol (1,3-PDO) through biotechnological interventions. This RCG contains several impurities like methanol, soap, organic materials, salts non-transesterified fatty acids and metals in varied concentrations. These impurities significantly affect yield and productivity of the bio-process due to their marked microbial toxicity. In this work, previously isolated Clostridium butyricum L4 was immobilized on various abundantly available cheap bio-wastes (like rice straw, activated carbon and corn cob) to explore advantages offered and improve tolerance to various feed impurities. Amongst these, shredded rice straw was found most suitable candidate for immobilization and results in maximum improvement in 1,3-PDO production (18.4%) with highest porosity (89.28%), lowest bulk density (194.48Kg/m3), and highest cellular biofilm density (CFU/g-8.4 ×1010) amongst the three matrices. For practical purposes, recyclability was evaluated and it was concluded that even after reusing for five successive cycles the production retained to ∼82.4%. Subsequently, polynomial model was developed using 30 runs central composite factorial design experiments having coefficient of regression (R²) as 0.9520, in order to predict yields under different immobilization conditions for 1,3-PDO production. Plackett-Burman was employed (Accuracy= 99.17%) to screen significant toxic impurities. Based on statistical analysis six impurities were found to be significantly influential on PDO production in adverse manner. With negative coefficient of estimate (COE) varying in decreasing order: Linoleic acid >Oleic acid >Stearic acid >NaCl>K2SO4 >KCl. The study illustrates practical application for repurposing waste glycerol generated from biodiesel plants, thus developing improved agnostic process along with yield production models.


Assuntos
Biocombustíveis , Glicerol , Fermentação , Propilenoglicóis , Propilenoglicol
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA