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1.
Chem Biodivers ; 21(5): e202400067, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38500408

RESUMO

Tuberculosis is a communicable disease which affects humans particularly the lungs and is transmitted mainly through air. Despite two decades of intensive research aimed at understanding and combating tuberculosis, persistent biological uncertainties continue to hinder progress. Nowadays, heterocyclic compounds have proven themselves in effective treatment of tuberculosis because of their wide range of biological and pharmacological activities. Antituberculosis or antimycobacterial agents encompass a broad array of compounds utilized singly or in conjunction to combat Mycobacterium infections, spanning from tuberculosis to leprosy. Here, we summarize the synthesis of various heterocyclic compounds which includes the greener synthetic route as well as use of nano compounds as catalyst along with their anti TB activities.


Assuntos
Antituberculosos , Compostos Heterocíclicos , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis , Antituberculosos/farmacologia , Antituberculosos/química , Antituberculosos/síntese química , Compostos Heterocíclicos/química , Compostos Heterocíclicos/farmacologia , Compostos Heterocíclicos/síntese química , Humanos , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose/tratamento farmacológico , Estrutura Molecular
2.
Environ Res ; 231(Pt 2): 116165, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37196691

RESUMO

In this study, the deployment of post Reverse Osmosis (RO)-carbon as a adsorbent for dye removal from water has been investigated. The post RO-carbon was thermally activated (RO900), and the material thus obtained exhibited high surface area viz. 753 m2/g. In the batch system, the efficient Methylene Blue (MB) and Methyl Orange (MO) removal was obtained by using 0.08 g and 0.13 g/50 mL adsorbent dosage respectively. Moreover, 420 min was the optimized equilibration time for both the dyes. The maximum adsorption capacities of RO900 for MB and MO dyes were 223.29 and 158.14 mg/g, respectively. The comparatively higher MB adsorption was attributed to the electrostatic attraction between adsorbent and MB. The thermodynamic findings revealed the process as spontaneous, endothermic, and accompanied by entropy increment. Additionally, simulated effluent was treated, and >99% dye removal efficiency was achieved. To mimic an industrial perspective, MB adsorption onto RO900 was also carried out in continuous mode. The initial dye concentration and effluent flow rate were among the process parameters that were optimized using the continuous mode of operation. Further, the experimental data of continuous mode was fitted with Clark, Yan, and Yoon-Nelson models. Py-GC/MS investigation revealed that dye-loaded adsorbents could be pyrolyzed to produce valuable chemicals. The cost and low toxicity associated benefits of discarded RO-carbon over other adsorbents reveal the significance of the present study.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Carbono , Corantes , Adsorção , Cinética , Termodinâmica , Azul de Metileno , Osmose , Concentração de Íons de Hidrogênio
3.
Drug Dev Ind Pharm ; 44(10): 1701-1712, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29938544

RESUMO

Tetrahydrocurcumin (THC) also referred to as 'white curcumin', is a stable colorless hydrogenated product of curcumin with superior antioxidant and anti-inflammatory properties. The present study is an attempt to elevate the topical bioavailability of THC, post-incorporation into a nano-carrier system with its final dosage as a hydrogel. Lipid nanoparticles of THC (THC-SLNs) prepared by microemulsification technique were ellipsoidal in shape (revealed in transmission electron microscopy) with a mean particle size of 96.6 nm and zeta potential of -22 mV. Total drug content and entrapment efficiency of THC-SLNs was 94.51% ± 2.15% and 69.56% ± 1.35%, respectively. Differential scanning calorimetry and X-ray diffraction studies confirmed the formation of THC-SLNs. In vitro drug release studies showed the drug release from THC-SLNs gel to follow Higuchi's equation revealing a Fickian diffusion. Ex vivo permeation studies indicated a 17 times (approximately) higher skin permeation of THC-SLNs gel as compared with the free THC gel. Skin irritation, occlusion, and stability studies indicated the formulation to be nonirritating, and stable with a desired occlusivity. Pharmacodynamic evaluation in an excision wound mice model clearly revealed the enhanced anti-inflammatory activity of THC-SLNs gel and was further confirmed using biochemical and histopathological studies. It is noteworthy to report here that THC-SLNs gel showed significantly better (p ≤ 0.001) activity than free THC in gel. As inflammation is innate to all the skin disorders, the developed product opens up new therapeutic avenues for several skin diseases. To the best of our knowledge, this is the first paper elaborating the therapeutic usefulness of white curcumin-loaded lipidic nanoparticles for skin inflammation.


Assuntos
Curcumina/análogos & derivados , Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/administração & dosagem , Absorção Cutânea/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Administração Cutânea , Animais , Curcumina/administração & dosagem , Curcumina/farmacocinética , Masculino , Camundongos , Nanopartículas/metabolismo , Técnicas de Cultura de Órgãos , Absorção Cutânea/fisiologia , Suínos , Resultado do Tratamento , Cicatrização/fisiologia
5.
Radiat Environ Biophys ; 55(3): 401-10, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27289385

RESUMO

In this study, measurements of indoor radon ((222)Rn), thoron ((220)Rn) and their equilibrium equivalent concentration (EEC) were carried out in 96 dwellings from 22 different villages situated in Hamirpur district, Himachal Pradesh, India, by using LR-115 type II-based pinhole twin cup dosimeters and deposition-based progeny sensors (DRPS/DTPS). The annual average indoor (222)Rn and (220)Rn concentrations observed in these dwellings were 63.82 and 89.59 Bq/m(3), respectively, while the average EEC (attached + unattached) for (222)Rn and (220)Rn was 29.28 and 2.74 Bq/m(3). For (222)Rn (f Rn) and (220)Rn (f Tn), the average values of unattached fraction were 0.11 and 0.09, respectively. The equilibrium factors for radon (F Rn) and thoron (F Tn) varied from 0.12 to 0.77 with an average of 0.50, and from 0.01 to 0.34 with an average of 0.05, respectively. The annual inhalation dose due to mouth and nasal breathing was calculated using dose conversion factors and unattached fractions. The indoor annual effective doses for (222)Rn (AEDR) and (220)Rn (AEDT) were found to be 1.92 and 0.83 mSv a(-1), respectively. The values of (222)Rn/(220)Rn concentrations and annual effective doses obtained in the present study are within the safe limits as recommended by the International Commission on Radiological Protection for indoor dwelling exposure conditions.


Assuntos
Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Radônio/análise , Habitação , Humanos , Índia , Doses de Radiação , Monitoramento de Radiação
6.
Curr Eye Res ; : 1-9, 2024 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-39099132

RESUMO

PURPOSE: The purpose of this study was to assess in-vitro efficacy of a suffusion of autologous serum withcyclosporine 0.05% (CsA) and sodium hyaluronate 0.1% (SH). METHODS: The expression of proinflammatory markers interleukin 6 (IL-6) and TNF-Alpha (TNF-α) in limbal epithelial cells was evaluated. Also, assessment of the stability of epithelial growth factor and transforming growth factor-beta (EGF, TGF-ß) in the 50% combinations with autologous serum (AS) was done. The characteristics (pH, density, osmolality) of the two combinations were also evaluated. Additionally, cytotoxicity effect of given test compounds was evaluated on human limbal epithelial cells (LEpiC). RESULTS: The percentage of cells expressing IL-6 subjected to AS + SH and AS + CsA were 6.23% and 5.69% respectively. There was no significant difference in percentage of cells expressing TNF-α between the formulations (5.87%, 5.83% respectively). The growth factors; EGF and TGF-ß remained stable forone month duration (on 2 and 4 weeks) at 4 °C without significant difference between the time intervals tested. The results of MTT assay suggested that limbal epithelial cells treated with AS + CsA and AS + SH combinations showed minimal toxicity however it was not significant statistically (p ≤ 0.05). CONCLUSION: Two test combinations (AS + CsA, AS + SH) showed stable growth factors (EGF, TGF-ß) and good anti-inflammatory property against pro-inflammatory markers. Also, the 2 combinations were found safe on cultured limbal epithelial cells. The novel combination of autologous serum in CsA may provide added benefit in dry eye disease (DED) through their combined anti-inflammatory and epitheliotropic effects.

7.
Sci Justice ; 53(2): 206-11, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23601730

RESUMO

Introduction of the digital techniques in document examination has encouraged the Forensic Document Examiners to work with better accuracy in non-destructive ways. In this study, the examination of sequence of intersecting strokes of printers (inkjet printer, laser printer, dot-matrix printer) and typewriters with writing instruments (gel ink pen, ballpoint pen and fountain pen) of different colors was carried out by using Docucenter Expert via PIA-6000 software utilizing extended depth of focus. The continuity of the stroke is the only characteristic which has been observed at the point of intersection.

8.
Sci Justice ; 53(2): 212-9, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23601731

RESUMO

The sequence of intersecting strokes of laser printers (black, blue, red and green) and typewriter ink (black) with the strokes of gel pen ink, ballpoint pen ink and fountain pen ink (black, blue, red and green) has been determined by studying their absorption spectra. The absorption spectra have been generated for each of the two pure inks (i.e. A and B) and points of their intersections (i.e. A over B and B over A) by using Video Spectral Comparator (VSC-2000-HR). The study was carried out with an assumption that the peak characteristics of spectra from the point of intersection should correspond to the peak characteristics of pure ink which was executed later. It was observed that the absorption spectrum of intersection corresponds with either the laser printer or the typewriter ink stroke, whether these strokes were executed earlier or later than the writing instrument strokes. As the results obtained from the study were negative, the FDEs are advised against the practice of this technique in the examination of the sequence of intersecting strokes for these specified inks.

9.
Pharmacol Rep ; 75(5): 1066-1095, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37668937

RESUMO

Atopic dermatitis (AD) is a predominant and deteriorating chronic inflammation of the skin, categorized by a burning sensation and eczematous lesions in diverse portions of the body. The treatment of AD is exclusively focused to limit the itching, reduce inflammation, and repair the breached barrier of the skin. Several therapeutic agents for the treatment and management of AD have been reported and are in use in clinics. However, the topical treatment of AD has been an unswerving challenge for the medical fraternity owing to the impaired skin barrier function in this chronic skin condition. To surmount the problems of conventional drug delivery systems, numerous nanotechnology-based formulations are emerging as alternative new modalities for AD. Latter enhances the bioavailability and delivery to the target disease site, improves drug permeation and therapeutic efficacy with reduced systemic and off-target side effects, and thus improves patient health and promotes compliance. This review aims to describe the various pathophysiological events involved in the occurrence of AD, current challenges in treatment, evidence of molecular markers of AD and its management, combinatorial treatment options, and the intervention of nanotechnology-based formulations for AD therapeutics.


Assuntos
Dermatite Atópica , Humanos , Dermatite Atópica/tratamento farmacológico , Administração Cutânea , Pele , Sistemas de Liberação de Medicamentos , Inflamação/tratamento farmacológico
10.
Sci Justice ; 62(1): 10-20, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35033322

RESUMO

Parkinsonism is a neurodegenerative syndrome that causes impairment of motor skills in affected persons. Thus, adverse effects may be produced in the handwriting of persons suffering from Parkinsonism. Medication used for the treatment of Parkinsonism is known to subside certain motor defects for specific time intervals, showing slight differences or improvement in certain handwriting characteristics during those intervals on the same day as compared to the ones executed before medication. Certain handwriting characteristics affected due to Parkinsonism may be mistaken as forged features due to poor line quality, which can cause suspicion upon the authenticity of important legal documents. The present research work has been carried out to determine the effects of Parkinsonism and medication used for its treatment on handwriting. Handwriting/signature samples executed before and after the onset of Parkinsonism (both pre- and post-medication) have been randomly collected from 70 participants. These handwritings have been evaluated separately and compared inter-se for various handwriting characteristics with qualitative and statistical approach. The results have demonstrated significant changes in most of the characteristics in both affected writings of majority of participants as compared to their corresponding earlier writings. Thus, forensic document experts should be aware of the detrimental effects of Parkinsonism on handwriting in pre- and post-medication conditions of this ailment.


Assuntos
Escrita Manual , Transtornos Parkinsonianos , Medicina Legal , Humanos
11.
Nanomaterials (Basel) ; 12(4)2022 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-35214966

RESUMO

Treatment of atopic dermatitis (AD) is challenging due to its complex pathophysiology. Tetrahydrocurcumin (THC) a polyphenolic, colorless compound that is more polar than curcumin. It possesses superior anti-inflammatory properties and has a clinical advantage over curcumin. The present study investigated the therapeutic effectiveness of THC solid lipid nanoparticle (THC-SLN)-based gels in AD. THC-SLNs prepared using microemulsification resulted in a particle size of 109.2 nm as determined by nanoparticle tracking, and FTIR confirmed the entrapment of drug within the lipid matrix. THC-SLNs greatly enhanced skin hydration when tested both ex vivo and in vivo in Lacca mice. Deeper skin penetration was clearly established using dermatokinetics and CLSM. The in vivo pharmacodynamics of THC-SLNs gel in 2,4-dinitrochlorobenzene (DNCB)-induced AD mice showed enhanced bioactivity; reduced levels of TNF-α and IL-6; and complete healing, as evident from histopathological studies. Thus, the novel topical THC-SLN gel has potential to emerge as a safe alternative to conventional corticosteroids for AD and other skin disorders with overbearing inflammation.

12.
Food Chem Toxicol ; 167: 113260, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35777714

RESUMO

Preclinical safety and proof of concept studies for a topical ointment comprising of concentrated tetrahydrocurcumin loaded lipidic nanoparticles (THC-LNs) and tacrolimus ointment (TTO) is proposed in the present investigation. The skin irritation potential and acute dermal toxicity were performed in rats in compliance with the Organization for Economic Cooperation and Development (OECD) guidelines (402, 404 and 410) while the cytotoxic potential was performed in HaCaT cells. Finally, in vivo evaluation was performed in Imiquimod mice model of psoriasis. In primary skin irritation assessment, TTO formulation, marketed formulation (Tacroz® Forte), THC-LNs, and blank LNs were topically applied on intact skin sites in rats while another group served as a negative control group for 72 h. TTO did not induce any adverse reactions. Repeated 28 days dermal toxicity followed by biochemical and histopathological assessment showed negligible alternations and skin lesions. THC-LNs revealed negligible cytotoxic potential in HaCaT cells. TTO showed significantly high anti-psoriatic activity in comparison to marketed ointment. This was also confirmed via histopathological evaluation. Based on these findings, it can be ascertained that TTO showed minimal toxicity and has ample potential for further clinical analysis. The above studies affirm the potential of TTO as an alternative for psoriasis.


Assuntos
Nanopartículas , Psoríase , Animais , Camundongos , Ratos , Curcumina/análogos & derivados , Camundongos Endogâmicos BALB C , Pomadas , Psoríase/tratamento farmacológico , Tacrolimo
13.
Artigo em Inglês | MEDLINE | ID: mdl-36251593

RESUMO

BACKGROUND: Debridement of toenails is a common procedure that leads to the production of nail dust aerosols in the work environment. Previous studies indicate that inhaled nail dust can cause respiratory distress and eye irritation. This comprehensive review aimed to assess the available literature on the effect of nail dust exposure and to evaluate nail dust as a potential occupational hazard for podiatric physicians. METHODS: A comprehensive literature search was conducted via PubMed, Google Scholar, CINAHL, Cochrane Library, and ClinicalTrials.gov. Risks of bias of the collected studies were evaluated using various assessment tools to match the type of study design. A qualitative analysis of the included studies was performed, from which primary and secondary outcome measures were extracted: prevalence of symptoms and specific microorganisms in nail dust. RESULTS: Of 403 articles screened, eight met the inclusion criteria. The primary outcome measure resulted in a pooled prevalence of eye-related symptoms being the most consistent symptom reported (41%-48%). The secondary outcome measure resulted in a pooled prevalence of Trichophyton rubrum (9.52%-38%) and Aspergillus (11.11%-35.48%) as the most common microorganisms present in nail dust. CONCLUSIONS: From the included eight articles, we found that nail dust is a potential occupational hazard, especially for those exposed more often. Aspergillus and T rubrum are most commonly associated with nail dust leading to development of respiratory illness. It is important to take preventive measures in podiatric medical clinics by using improved and efficient personal protective equipment for workers exposed to nail dust. Detailed health safety guidelines can be developed to decrease respiratory symptoms and diseases from nail dust exposure.


Assuntos
Doenças Profissionais , Podiatria , Aerossóis , Poeira/prevenção & controle , Humanos , Unhas , Doenças Profissionais/etiologia
14.
Bioresour Technol ; 342: 125924, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34562713

RESUMO

In this study, lignin-derived zeolite templated carbon materials were fabricated to remove the organic contaminant, methyl orange. Response surface methodology with Box-Behnken design was used to optimize the adsorption parameters. Based on Box-Behnken design, a quadratic model was developed to correlate the adsorption variables with the response, removal efficiency. Analysis of variance revealed the adsorbent dosage as the most influential adsorption variable. Lignin derived ZSM-5 (PZ) and mordenite (PM) templated carbon materials exhibited high surface area; 476.0 and 716.0 m2/g respectively. The maximum theoretical adsorption capacity of PZ and PM for methyl orange was 514.0 and 225.0 mg/g, respectively. The experimental kinetic data best fitted to pseudo-second-order model for both the adsorbents. PZ adsorbent was also utilized to treat real wastewater containing dyes and achieved 40 % methyl orange removal efficiency. Adsorption thermodynamic study revealed the process as spontaneous, exothermic and also indicated the increment in entropy after adsorption.


Assuntos
Carbono , Poluentes Químicos da Água , Adsorção , Compostos Azo , Concentração de Íons de Hidrogênio , Cinética , Lignina , Termodinâmica , Poluentes Químicos da Água/análise
15.
Bioresour Technol ; 342: 125948, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34571330

RESUMO

Hydrothermal liquefaction (HTL) effectively converts biomass to biofuels, thereby limiting the endless reliance on petroleum products derived from fossil fuels. However, the conversion is based on individual feedstock in the HTL process. In order to, further boost the conversion, HTL can be done by blending various feedstock, mainly algal and lignocellulosic biomass. Bibliometric analysis was carried out, and it was observed that there have been very few studies on Co-Hydrothermal Liquefaction (Co-HTL). There still exist several crucial gaps in process optimization when co-reactants are used due to their synergistic effects. The reaction kinetics and mechanism, catalyst screening and by-products application require further studies. Therefore, R&D is necessary to optimize the process to completely utilize the complementarity of the feedstocks under study resulting in better quality of products which require minor/ no upgradation steps.


Assuntos
Lignina , Petróleo , Biocombustíveis , Biomassa , Temperatura , Água
16.
Pharm Nanotechnol ; 9(2): 130-140, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33511962

RESUMO

BACKGROUND: Envisaging the poor solubility (56 ngml1) and permeability of tetrahydrocurcumin (THCC), it was formulated into lipidic nanostructures to enhance its bioavailability upon topical application to promote the healing process for skin inflammatory disorders. Lack of literature on a suitable method for determining THCC per se and nanoformulations prompted us to develop an RP-HPLC method to detect the drug in its nanostructures and in pig ear skin post dermatokinetics. OBJECTIVE: The present investigation aimed to develop a simple, precise and RP-HPLC method for the quantitative estimation of THCC in prepared lipidic nanostructures, its ointment, and in skin homogenate obtained post dermatokinetic study. METHODS: THCC encapsulated nanostructures and ointment were formulated using a modified emulsification method and embedded into an ointment base to enhance its spreadability and improve patient compliance. A fast and sensitive reverse-phase high-performance liquid chromatography method was developed using a Hypersil BDS reverse phase C18 column (4.6 mm × 250 mm, 5 µm) with mobile phase comprising tetrahydrofuran (THF) and 1 mgmL-1 citric acid (4:6), at a flow rate of 1.0 mLmin-1 with a run time of 20 min. RESULTS: THCC nanostructures were successfully prepared using the spontaneous microemulsification method. THCC was detected at 282 nm and revealed two peaks which were attributed to the keto-enol tautomerism in the molecule with retention times of 6.23 min and 11.06 min, respectively. The assay of THCC in nanostructures and ointment was found to be 98.30 % and 99.98 %, with an entrapment efficiency 77.00±2.74 %. The dermatokinetic studies revealed sufficient release of THCC from its ointment up to 24 hr with a concentration of 1382 µgcm-2, for causing a therapeutic effect. CONCLUSION: The method was found to be reproducible and robust, as shown by the low coefficient of variation and a constant analyte/IS ratio. It was successfully employed for the estimation of THCC assay in nanostructures and its ointment and dermatokinetic analysis in the skin.


Assuntos
Curcumina , Nanoestruturas , Animais , Cromatografia Líquida de Alta Pressão , Curcumina/análogos & derivados , Lipídeos , Suínos
17.
Eur Biophys J ; 39(10): 1445-51, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20376437

RESUMO

Proper determination of the temperature dependence of intrinsic tryptophan fluorescence intensity in native and denatured states is an essential prerequisite for extracting the free energy of protein unfolding from the thermal denaturation profile. The most common method employed in determining the temperature dependence of these conformations is through the determination of slopes of pre- and post-transition baselines. However, simulations of protein unfolding profiles suggest that this method does not work for marginally stable proteins. We show herein that the temperature dependence of the fluorescence intensity of N-acetyl tryptophanamide (NATA) in organic solvents and water may be used to represent the temperature dependence of the fluorescence intensity of tryptophan in native and denatured conformations of a protein, respectively. The wavelength of the emission maximum, lambda (max), of N-acetyl tryptophanamide (NATA) in a particular solvent or tryptophan in proteins is related to the temperature dependence (m) of its fluorescence intensity by the equation: m (K(-1)) = (-0.000299 +/- 2.2 x 10(-5) K(-1) nm(-1)) x lambda (max) (nm) + (0.0919 +/- 0.0025 K(-1)).


Assuntos
Proteínas/química , Triptofano/química , Simulação por Computador , Fluorescência , Cinética , Modelos Químicos , Método de Monte Carlo , Compostos Orgânicos/química , Desnaturação Proteica , Dobramento de Proteína , Solventes/química , Espectrometria de Fluorescência , Temperatura , Triptofano/análogos & derivados , Água/química
18.
J Forensic Sci ; 65(4): 1337-1341, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32069371

RESUMO

Laser printers and writing instruments are being exploited by the forgers to produce fabricated documents. They often produce such documents by appending genuine signature on a blank sheet and later printing on it. Often these fabricated documents do not contain intersection of strokes and may pose a difficulty to forensic document examiners in analyzing cases related to such documents. Keeping in mind the limited research work done on nonintersecting strokes, the present study has been conducted with an aim to determine the sequence of nonintersecting strokes of gel pens and laser printers. Three hundred samples of nonintersecting strokes of gel pen ink and laser printing were prepared. Of these 300, 150 had laser-printed text below the gel pen strokes and the remaining 150 were prepared with gel pen stokes below the laser-printed text. The samples have been analyzed using Nikon SMZ 800N stereomicroscope. Three micro-conformation features, that is, pattern of toner distribution, ink distribution, and fiber distribution have been observed in the samples. The results demonstrate the successful establishment of sequence of nonintersecting strokes in case of gel pen and laser-printed documents by the determination of micro-conformation features.

19.
Bioresour Technol ; 310: 123442, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32362429

RESUMO

Utilization of natural, abundant, and renewable resources for the production of carbon materials with simple and energy-efficient processes is an upsurge interest. The production processes and resultant biochar can address widespread concerns such as climate change, energy crisis, and environmental pollution. The properties of produced chars (biochar/hydrochar) depend on the production methods, feedstock, and operating parameters, which significantly affect their use for various applications. In this review, production, physiochemical properties, and techno-economic analysis of chars are summarized. This review provides the fundamentals and reaction mechanism of char production methodologies. Physicochemical properties based on chemical composition, functional groups, structure, porosity, and shapes have been compared. The effects of operating parameters on the physicochemical properties of chars are discussed. In addition, this review offers insights on new directions for char production and research in the future, based on the updated and detailed investigation of energy balance with economy of char production methodologies.


Assuntos
Carbono , Carvão Vegetal , Mudança Climática
20.
Bioresour Technol ; 299: 122564, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31879059

RESUMO

The aim of this review is to provide the comprehensive and mechanistic information of biochar based catalytic systems for the production of fuels and fine chemicals with a concept of integrated biorefinery. The review presents an in-depth assessment of relationships between physico-chemical properties and catalytic performances of biochar based catalytic systems during the production of targeted compounds at the molecular/fundamental level. The catalytic performance of the biochar is associated with its unique physico-chemical properties (surface area/surface functionality/pores/mechanical strength/inorganic species) which provide a distinct catalytic route. The review also discusses the preparation methods and significance of the activation process for tuning of physico-chemical properties of biochar.


Assuntos
Carvão Vegetal , Catálise
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