Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 12 de 12
Filtrer
Plus de filtres










Base de données
Gamme d'année
1.
Molecules ; 28(24)2023 Dec 16.
Article de Anglais | MEDLINE | ID: mdl-38138616

RÉSUMÉ

Hydrothermal liquefaction (HTL) represents a beacon of scientific innovation, which unlocks nature's alchemical wonders while reshaping the waste-to-energy platform. This transformative technology offers sustainable solutions for converting a variety of waste materials to valuable energy products and chemicals-thus addressing environmental concerns, inefficiencies, and high costs associated with conventional waste-management practices. By operating under high temperature and pressure conditions, HTL efficiently reduces waste volume, mitigates harmful pollutant release, and extracts valuable energy from organic waste materials. This comprehensive review delves into the intricacies of the HTL process and explores its applications. Key process parameters, diverse feedstocks, various reactor designs, and recent advancements in HTL technology are thoroughly discussed. Diverse applications of HTL products are examined, and their economic viability toward integration in the market is assessed. Knowledge gaps and opportunities for further exploration are accordingly identified, with a focus on optimizing and scaling up the HTL process for commercial applications. In conclusion, HTL holds great promise as a sustainable technology for waste management, chemical synthesis, and energy production, thus making a significant contribution to a more sustainable future. Its potential to foster a circular economy and its versatility in producing valuable products underscore its transformative role in shaping a more sustainable world.

2.
J Echocardiogr ; 21(3): 122-130, 2023 09.
Article de Anglais | MEDLINE | ID: mdl-37219722

RÉSUMÉ

PURPOSE: Our clinical observations showed clot formations in different regions of the left ventricle of the heart in some COVID-19 patients with normal myocardial motion and coronary artery. The aim of this study was to examine the changes caused by COVID-19 disease on blood flow inside the heart as a possible etiology of intracardiac clot formation. METHODS: In a synergic convergence of mathematics, computer science, and cardio-vascular medicine, we evaluated patients hospitalized due to COVID-19 without cardiac symptoms who underwent two-dimensional echocardiography. Patients with normal myocardial motions on echocardiography, normal coronary findings on noninvasive cardio-vascular diagnostic tests, and normal cardiac biochemical examinations but who presented with a clot in their left ventricle were included. To display the velocity vectors of the blood in the left ventricle, motion and deformation echocardiographic data were imported into MATLAB software. RESULTS: Analysis and output of the MATLAB program indicted anomalous blood flow vortices inside the left ventricular cavity, indicating irregular flow and turbulence of the blood inside the left ventricle in COVID-19 patients. CONCLUSION: Our results suggest that in some COVID-19 patients, cardiac wall motion is not satisfactorily able to circulate the blood fluid in normal directions and that, despite normal myocardium, changes in the directions of blood flow inside the left ventricle might lead to clots in different zones. This phenomenon may be related to changes in blood properties, such as viscosity.


Sujet(s)
COVID-19 , Ventricules cardiaques , Humains , Ventricules cardiaques/imagerie diagnostique , COVID-19/complications , Coeur , Échocardiographie/méthodes , Myocarde
3.
Molecules ; 27(5)2022 Feb 22.
Article de Anglais | MEDLINE | ID: mdl-35268582

RÉSUMÉ

Contamination of the biosphere by heavy metals has been rising, due to accelerated anthropogenic activities, and is nowadays, a matter of serious global concern. Removal of such inorganic pollutants from aquatic environments via biological processes has earned great popularity, for its cost-effectiveness and high efficiency, compared to conventional physicochemical methods. Among candidate organisms, microalgae offer several competitive advantages; phycoremediation has even been claimed as the next generation of wastewater treatment technologies. Furthermore, integration of microalgae-mediated wastewater treatment and bioenergy production adds favorably to the economic feasibility of the former process-with energy security coming along with environmental sustainability. However, poor biomass productivity under abiotic stress conditions has hindered the large-scale deployment of microalgae. Recent advances encompassing molecular tools for genome editing, together with the advent of multiomics technologies and computational approaches, have permitted the design of tailor-made microalgal cell factories, which encompass multiple beneficial traits, while circumventing those associated with the bioaccumulation of unfavorable chemicals. Previous studies unfolded several routes through which genetic engineering-mediated improvements appear feasible (encompassing sequestration/uptake capacity and specificity for heavy metals); they can be categorized as metal transportation, chelation, or biotransformation, with regulation of metal- and oxidative stress response, as well as cell surface engineering playing a crucial role therein. This review covers the state-of-the-art metal stress mitigation mechanisms prevalent in microalgae, and discusses putative and tested metabolic engineering approaches, aimed at further improvement of those biological processes. Finally, current research gaps and future prospects arising from use of transgenic microalgae for heavy metal phycoremediation are reviewed.


Sujet(s)
Microalgues
4.
Mol Biol Rep ; 46(3): 3129-3140, 2019 Jun.
Article de Anglais | MEDLINE | ID: mdl-30937652

RÉSUMÉ

As one of the most prevalent malignancies, breast cancer still remains a significant risk for public health. Common therapeutic strategies include invasive surgery, chemotherapy and anti-herceptin antibodies. Adverse effects, drug resistance and low efficacy of current therapies necessitates the emergence of more effective platforms. Naturally released by the immune system, granzyme B activates multiple pro-apoptotic pathways by cleaving critical substrates. Bacterial cupredoxin, azurin, selectively targets cancer cells via a p53-dependent pathway. Fused by a linker, GrB-Azurin fusion protein was overexpressed in HEK293T cells, and purified by metal chromatography. SDS-PAGE, Western blotting and ELISA were performed to confirm successful expression, purification and analyze binding properties of the fusion protein. After treatment of various breast cancer cell lines with increasing concentrations of GrB-Azurin, quantitative real-time RT-PCR was used to measure relative expression of p21, Fas and DR5 pro-apoptotic genes. The results of DNA fragmentation and WST-1 cell viability assays indicated significant apoptosis induction in MDA-MB-231, MCF7 and SK-BR-3 cells, while insignificant cytotoxicity was detected on MCF 10A normal breast cells. Herein, we report the development of a novel biotherapeutic against breast cancer. Selective effectiveness of GrB-Azurin fusion protein on different breast cancer cells highlighted the potential of the designed construct as a candidate anti-cancer biodrug.


Sujet(s)
Azurine/génétique , Granzymes/génétique , Protéines de fusion recombinantes/génétique , Séquence d'acides aminés , Azurine/composition chimique , Azurine/métabolisme , Tumeurs du sein/génétique , Tumeurs du sein/métabolisme , Lignée cellulaire tumorale , Activation enzymatique , Femelle , Expression des gènes , Ordre des gènes , Vecteurs génétiques/génétique , Granzymes/composition chimique , Granzymes/métabolisme , Cellules HEK293 , Humains , Protéines de fusion recombinantes/composition chimique , Protéines de fusion recombinantes/métabolisme , Transfection
5.
Prep Biochem Biotechnol ; 49(3): 222-229, 2019.
Article de Anglais | MEDLINE | ID: mdl-30806151

RÉSUMÉ

Despite the ever-growing demand for proteins in pharmaceutical applications, downstream processing imposes many technical and economic limitations to recombinant technology. Elastin-like polypeptides tend to aggregate reversibly at a specific temperature. These biopolymers have been joined with self-cleaving inteins to develop a non-chromatographic platform for protein purification without the need for expensive enzymatic tag removal. Following the design and expression of an ELP-intein-tagged GFP, herein, we report certain complications and setbacks associated with this protein purification system, overlooked in previous studies. Based on our results, a recovery rate of 68% was achieved using inverse transition cycling. Fluorescence intensity analysis indicated a production yield of 11 mg GFP fusion protein per liter of bacterial culture. The low expression level is attributable to several factors, such as irreversible aggregation, slipped-strand mispairing or insufficiency of aminoacyl tRNAs during protein translation of the highly repetitive ELP tag. While the goals we set out to achieve were not entirely met, a number of useful tips could be gathered as a generic means for implementing ELP-intein protein purification. Overall, we believe that such reports help clarify the exact capacity of emerging techniques and build a fairly realistic prospect toward their application.


Sujet(s)
Élastine/isolement et purification , Protéines à fluorescence verte/isolement et purification , Intéines , Protéines de fusion recombinantes/isolement et purification , Technique de Western , Élastine/composition chimique , Élastine/génétique , Électrophorèse sur gel de polyacrylamide , Escherichia coli , Fluorescence , Protéines à fluorescence verte/composition chimique , Protéines à fluorescence verte/génétique , Protéines de fusion recombinantes/composition chimique , Protéines de fusion recombinantes/génétique , Température de transition
6.
J Liposome Res ; 29(1): 53-65, 2019 Mar.
Article de Anglais | MEDLINE | ID: mdl-29621912

RÉSUMÉ

Synergistic effect of combined antibodies targeting distinct epitopes of a particular tumour antigen has encouraged some clinical trial studies and is now considered as an effective platform for cancer therapy. Providing several advantages over conventional antibodies, variable domain of heavy chain of heavy chain antibodies (VHH) is now major tools in diagnostic and therapeutic applications. Active targeting of liposomal drugs is a promising strategy, resulting in enhanced binding and improved cytotoxicity of tumour cells. In the present study, we produced four anti-HER2 recombinant VHHs and purified them via native and refolding method. ELISA and flow cytometry analysis confirmed almost identical function of VHHs in refolded and native states. Using a mixture of four purified VHHs, PEGylated liposomal doxorubicin was targeted against HER2-overexpressing cells. The drug release was analyzed at pH 7.4, 6.4 and 5.5 and dynamic light-scattering detector and TEM micrograph was applied to characterize the produced nanoparticles. The binding efficiency of these nanoparticles to BT474 and SKBR3 as HER2-positive and MCF10A as HER2-negative cell line was examined by flow cytometry. Our results indicated effective encapsulation of about 94% of the total drug in immunoliposomes. Flow cytometry results verified receptor-specific binding of targeted liposomes to SKBR3 and BT474 cell lines and more efficient binding was observed for liposomes conjugated with oligoclonal VHHs mixture compared with monoclonal VHH-targeted liposomes. Oligoclonal nanoparticles also showed more cytotoxicity compared with non-targeted liposomes against HER2-positive tumour cells. Oligoclonal targeting of liposomes was represented as a promising strategy for the treatment of HER2-overexpressing breast cancers.


Sujet(s)
Doxorubicine/analogues et dérivés , Bandes oligoclonales , Récepteur ErbB-2 , Antinéoplasiques/administration et posologie , Tumeurs du sein/traitement médicamenteux , Tumeurs du sein/immunologie , Lignée cellulaire tumorale , Doxorubicine/administration et posologie , Systèmes de délivrance de médicaments , Femelle , Humains , Liposomes/composition chimique , Thérapie moléculaire ciblée , Nanoparticules , Polyéthylène glycols/administration et posologie , Récepteur ErbB-2/antagonistes et inhibiteurs , Récepteur ErbB-2/immunologie
7.
Biomed Rep ; 10(1): 33-38, 2019 Jan.
Article de Anglais | MEDLINE | ID: mdl-30588301

RÉSUMÉ

Influenza type A is considered as a severe public health concern. The mechanism of drugs applied for the control of this virus depends on two surface glycoproteins with antigenic properties, namely hemagglutinin (HA) and neuraminidase (NA). HA aids the virus to penetrate cells in the early stage of infection and NA is an enzyme with the ability to break glycoside bonds, which enables virion spread through the host cell membrane. Since NA contains a relatively preserved active site, it has been an important target in drug design. Oseltamivir is a common drug used for the treatment of influenza infections, for which cases of resistance have recently been reported, giving rise to health concerns. Flavonoids are natural polyphenolic compounds with potential blocking effects in the neuraminidase active site. Based on their antiviral effect, the flavonoids quercetin, catechin, naringenin, luteolin, hispidulin, vitexin, chrysin and kaempferol were selected in the present study and compared alongside oseltamivir on molecular docking, binding energy and active site structure, in order to provide insight on the potential of these compounds as targeted drugs for the control and treatment of influenza type A. The molecular characterization of flavonoids with binding affinity was performed using AutoDock Vina software. The results indicated that these compounds may effectively block the NA active site. Therefore, these natural compounds derived from fruits have the potential for development into drugs for controlling influenza, which may aid overcome the clinical challenge of the H1N1 strain epidemic.

8.
Mol Immunol ; 96: 98-109, 2018 04.
Article de Anglais | MEDLINE | ID: mdl-29549861

RÉSUMÉ

Breast cancer is the leading cause of mortality among all cancers. HER2, human epidermal growth factor receptors type 2, a receptor tyrosine kinase that induces interminable cell proliferation, is overexpressed in 20-25 percent of breast cancers. In spite of significant progress in nanomedicine in the past decade, being subjected to genetic drift that hides many paramount epitopes has rendered targeting HER2 as a big challenge. In the present study, we developed monovalent and bivalent monospecific along with bivalent bispecific VHH targeting different epitopes on HER2, and showed that bivalent bispecific VHH has the highest affinity among other tested modalities. Then we covalently coupled VHHs to the fluorescent labeled liposomal nanoparticle to produce targeted liposomes. Based on flow cytometry results, bivalent bispecific VHH targeted liposomes showed the highest fluorescent intensity, on HER2 breast cancer cells. Liposomes conjugated to bivalent monospecific VHH exhibited enhanced affinity toward HER2 positive cell lines compared to monovalent targeted liposomes, with bivalent bispecific liposomes appearing as the most robust probe.


Sujet(s)
Tumeurs du sein , Thérapie moléculaire ciblée/méthodes , Nanomédecine/méthodes , Récepteur ErbB-2/antagonistes et inhibiteurs , Anticorps à domaine unique/immunologie , Affinité des anticorps , Lignée cellulaire tumorale , Femelle , Humains , Immunothérapie/méthodes , Liposomes , Nanoparticules , Anticorps à domaine unique/pharmacologie
10.
Hepat Mon ; 16(10): e38828, 2016 Oct.
Article de Anglais | MEDLINE | ID: mdl-27882064

RÉSUMÉ

BACKGROUND: Cancerous cells proliferate as fast as possible without a proper surveillance system. This rapid cell division leads to enormous mutation rates, which help a tumor establish. OBJECTIVES: This study evaluated the potential of inducing apoptosis using Noxa and Puma in a hepatocarcinoma cell line. METHODS: The current study generated two recombinant lentiviruses, pLEX-GCN and pLEX-GCP, bearing Noxa and Puma, respectively. Transduction of both genes to hepatocarcinoma (HepG2) was verified using fluorescent microscopic analysis, western blotting, and quantitative real-time polymerase chain reaction (PCR). To evaluate the potential of Noxa and Puma to initiate apoptosis, a caspase-9 real-time, MTT assay, and a 4', 6-diamidino-2-phenylindole (DAPI) reagent were performed to stain apoptotic cells. RESULTS: The data verified successful transduction to HepG2 and HEK293T. Higher relative expression of Noxa and Puma rather than the untransduced cell line showed these genes are expressed more in HepG2 in comparison to HEK293T. The results of the real-time PCR, MTT assay, and DAPI reagent illustrated that higher cells initiated apoptosis following Puma transduction rather than Noxa. CONCLUSIONS: In this approach, the suicide gene was transferred to transformed cells and ignited apoptosis to exterminate them. Puma is a more potent killer gene and has higher capabilities to start intrinsic apoptosis pathway.

11.
Iran J Biotechnol ; 14(3): 185-191, 2016 Sep.
Article de Anglais | MEDLINE | ID: mdl-28959335

RÉSUMÉ

BACKGROUND: Puma is a highly robust pro-apoptotic protein. The protein becomes activated by p53 ensuing beyond-repair DNA damage. Downregulation of SIRT 1, by miR-128, elevates activated p53 that foment Puma indirectly. OBJECTIVES: In the present study, we used two-expression Adeno-Associated Virus (AAV) system for co-expression of miR-128 and Puma in order to evaluate apoptotic response; both in the tumor and normal cells, respectively. MATERIALS AND METHODS: Three recombinant AAVs constructs were generated. The First rAAV bearing Puma under the control of hTERT (p-AAV), the second construct designed such that to carry miR-128 downstream of CMV (mi-AAV), and the last construct comprises of the both CMV-miR-128 and hTERT- Puma. Real-Time PCR and western blotting were used to evaluate expression levels of the transduced genes. RESULTS: MTT assay and DAPI staining shown suicidal effect of each recombinant AAV vectors. p-AAV cytotoxicity was recorded for 62% of the tumor cells, while for normal cells it was only 20% cytotoxic. The second construct, mi-AAV, was not as potent and selective as p-AAV. This construct was shown to be 27% and 16% cytotoxic for BT-474 and HEK-293 cells, respectively. Co-expression of Puma and miR-128 (p-mi-AAV) was accomplished with a selective cytotoxicity toward BT-474. This construct was 85% toxic for tumor cells, although it was only 25% toxic for the normal cell line (HEK-293). CONCLUSIONS: In this study, we have shown that not only Puma is able to instigate apoptotic response but also its co-expression along with miR-128 could significantly enhance apoptosis in a synergistic manner.

SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE
...