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1.
Adv Exp Med Biol ; 1370: 445-460, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35882818

RESUMO

Lead (Pb2+) is a developmental neurotoxicant that disrupts the GABA-shift and subsequently causes alterations in the brain's excitation-to-inhibition (E/I) balance. Taurine is a well-established neuroprotective and inhibitory compound for regulating brain excitability. Since mechanistically taurine can facilitate neuronal inhibition through the GABA-AR, the present study examined the anxiolytic potential of taurine derivatives. Treatment groups consisted of the following developmental Pb2+-exposures: Control (0 ppm) and Perinatal (150 ppm or 1,000 ppm lead acetate in the drinking water). Rats were scheduled for behavioral tests between postnatal days (PND) 36-45 with random drug assignments to either saline, taurine, or taurine-derived compound (TD-101, TD-102, or TD-103) to assess the rats' responsivity to each drug in mitigating the developmental Pb2+-exposure and anxiety-like behaviors through the GABAergic system. Long-Evans hooded rats were assessed using an open field (OF) test for preliminary locomotor assessment. Twenty-four hours later, the same rats were exposed to the elevated plus maze (EPM) and were given an i.p. injection of 43 mg/Kg of the saline, taurine, or TD drugs 15 min prior to testing. Each rat was tested using the triple-blind random assignment method for each drug condition. The OF data revealed that Control female rats had increased locomotor activity over Control male rats, and the Pb2+-exposed males and females had increased locomotor activity when compared to the Control male and female rats. However, in the EPM, the Control female rats exhibited more anxiety-like behaviors over Control male rats, and the Pb2+-exposed male and female rats showed selective responsivity to TD drugs when compared to taurine. For Pb2+-exposed males, TD-101 showed consistent recovery of anxiety-like behaviors similar to that of taurine regardless of Pb2+ dose, whereas in Pb2+-exposed females TD-101 and TD-103 showed greater anxiolytic responses in the EPM. The results from the present psychopharmacological study suggests that taurine and its derivatives are interesting drug candidates to explore sex-specific mechanisms and actions of taurine and the associated GABAergic receptor properties by which these compounds alleviate anxiety as a potential behavioral pharmacotherapy for neurodevelopmental Pb2+ exposure.


Assuntos
Ansiolíticos , Animais , Feminino , Masculino , Gravidez , Ratos , Ansiolíticos/farmacologia , Ansiolíticos/uso terapêutico , Ansiedade/induzido quimicamente , Ansiedade/tratamento farmacológico , Ácido gama-Aminobutírico , Chumbo/toxicidade , Ratos Long-Evans , Taurina/farmacologia , Taurina/uso terapêutico
2.
Nanotechnology ; 32(48)2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34425561

RESUMO

SnO2is widely used for ethanol-sensing applications due to its excellent physicochemical properties, low toxicity and high sensitivity. However it is a challenge to construct 3D-hierarchical structures with sub 5 nm primary grain particle, which is the optimized size for ethanol sensor. Herein, genetic tri-level hierarchical SnO2microstructures are synthesised by the genetic conversion of 3D hierarchical SnS2flowers assembled by ultrathin nanosheets. The SnS2nanosheets are morphology genetic converted to porous nanosheets with sub 5 nm SnO2nanoparticles during the calcination process. When used for the detection of ethanol, the sensor exhibits a high sensitivity of 0.5 ppm (Ra/Rg = 6.8) and excellent gas-sensing response (Ra/Rg= 183 to 100 ppm) with short response/recovery time (12 s/11 s). The excellent gas sensing performance is much better than that of the previous reported SnO2-based sensors. The highly sensitivity is attributed to the large surface area derived from the recrystallization and volume changes, which offers more active sites during the morphology genetic conversion from SnS2to SnO2. Furthermore, the flower-like 3D structure enhances the stability of the materials and is beneficial for the mass diffusion dynamics of ethanol.

3.
Drug Dev Ind Pharm ; 47(3): 477-483, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33621153

RESUMO

Background: Organ transplantation is an important and critical procedure, which requires the suppression of immunity, and to suppress the immunity, a constant plasma concentration of immunosuppressant is required.Objectives: The said objective can be achieved by formulating a controlled release drug delivery system of the drug. Chitosan (CHT) nanoparticles (NPs) have been revolutionizing the conventional drug delivery system, for the past two decades. The aim of the current research work was to develop and evaluate CHT-based mycophenolate mofetil (MMF) loaded nanoparticles (CHT/MMF-NPs) using different drug to polymer ratios.Methods: The challenge was to entrap a lipophilic drug within NPs by the ionic gelation method of the positively charged CHT, using tripolyphosphate (TPP) as the crosslinking agent. The prepared CHT/MMF-NPs were evaluated for physical and chemical characterizations, including particle size, surface charge, entrapment efficiency (EE), surface morphology by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) for chemical compatibilities, X-ray diffractometry (XRD) and in-vitro dissolution studies.Results: Outcomes of the studies revealed that particles were 260 ± 17 nm in diameter, with the smooth and regular surface. Satisfactory values of EE (99%) have indicated the suitability of selected ingredients and employed methodology. Moreover, FTIR has confirmed the chemical compatibilities of the formulations. In-vitro dissolution studies have indicated diffusion type of controlled and sustained drug release during 24 h, with zero-order, as best fit kinetic model.Conclusion: Conclusively, the successful achievement of objectives has indicated the suitability of excipients and methodology to prepare CHT/MMF-NPs for better therapeutic outcomes.


Assuntos
Quitosana , Nanopartículas , Quitosana/metabolismo , Preparações de Ação Retardada , Portadores de Fármacos , Liberação Controlada de Fármacos , Ácido Micofenólico , Tamanho da Partícula , Espectroscopia de Infravermelho com Transformada de Fourier
4.
Water Sci Technol ; 83(1): 1-25, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33460403

RESUMO

Cryptosporidium spp. are one of the most important waterborne pathogens worldwide and a leading cause of mortality from waterborne gastrointestinal diseases. Detection of Cryptosporidium spp. in water can be very challenging due to their low numbers and the complexity of the water matrix. This review describes the biology of Cryptosporidium spp. and current methods used in their detection with a focus on C. parvum and C. hominis. Among the methods discussed and compared are microscopy, immunology-based methods using monoclonal antibodies, molecular methods including PCR (polymerase chain reaction)-based assays, and emerging aptamer-based methods. These methods have different capabilities and limitations, but one common challenge is the need for better sensitivity and specificity, particularly in the presence of contaminants. The application of DNA aptamers in the detection of Cryptosporidium spp. oocysts shows promise in overcoming these challenges, and there will likely be significant developments in aptamer-based sensors in the near future.


Assuntos
Criptosporidiose , Cryptosporidium parvum , Cryptosporidium , Animais , Cryptosporidium/genética , Oocistos , Água
5.
Can J Microbiol ; 65(11): 851-857, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31404505

RESUMO

Environmentally stable and disinfectant-resistant oocysts of Cryptosporidium spp. shed in the feces of infected humans and animals frequently contaminate water resources and are subsequently spread via potable and recreational waters. The current monoclonal-antibody-based methods for detecting them in water are slow, labor-intensive, and demand skills to interpret the results. We have developed DNA-aptamer-based aptasensors, coupled with magnetic beads, to detect and identify the oocysts of C. parvum for monitoring recreational and drinking water sources. A sensitive and specific electrochemical aptasensor (3'-biotinylated R4-6 aptamer) was used as a secondary ligand to bind the streptavidin-coated magnetic beads. This was incorporated into a probe using gold nanoparticle modified screen-printed carbon electrodes. Square wave voltammetry allowed for specific recognition of C. parvum oocysts. The aptamer-coated probes had an oocyst detection limit of 50. It did not bind to the cysts of Giardia duodenalis, another common waterborne pathogen, thus indicating its high specificity for the target pathogen. The system could successfully detect C. parvum oocysts in spiked samples of the raw lake and river waters. Therefore, the combined use of the aptasensor and magnetic beads has the potential to monitor water quality for C. parvum oocysts in field samples without relying on monoclonal antibodies and skill-demanding microscopy.


Assuntos
Aptâmeros de Nucleotídeos/genética , Cryptosporidium parvum/isolamento & purificação , Água Potável/parasitologia , Magnetismo/métodos , Rios/parasitologia , Animais , Cryptosporidium parvum/classificação , Cryptosporidium parvum/genética , Ouro/química , Humanos , Magnetismo/instrumentação , Nanopartículas Metálicas/química , Oocistos/classificação , Oocistos/genética , Oocistos/isolamento & purificação , Sensibilidade e Especificidade , Recursos Hídricos
6.
Adv Exp Med Biol ; 1155: 821-846, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31468450

RESUMO

Lead (Pb2+) is a developmental neurotoxicant that causes lifelong cognitive dysfunctions. In particular, Pb2+-induced frontoexecutive dysfunctions emerge later in life when the cortex is fully myelinated, thereby permitting the ability to assess the extent to which Pb2+ has developmentally impacted higher order cognitive and behavioral systems. The present study evaluated the effects of developmental Pb2+-exposure (150 ppm lead acetate in the drinking water) in Long Evans Hooded rats through the Attention Set-Shift Test (ASST) between postnatal days (PND) 60-90. Treatment groups were comprised of Control (0 ppm), Perinatal (150 ppm), and Perinatal+Taurine (150 ppm + 0.05% Taurine in the drinking water) rats (N = 36; n = 6 per treatment group for each sex). Frontoexecutive functions were evaluated based on trials-to-criterion (TTC) and errors-to-criterion (ETC) measures for simple and complex discriminations (SD & CD), intradimensional and extradimensional shifts (ID & ED), as well as reversals (Rev) of the CD, I-, and ED stages, respectively. Post-testing, the prelimbic (PrL), infralimbic (IL), orbital ventral frontal (OV), orbital ventro-lateral (OVL), and hippocampal (HP) brain regions were extracted and processed through Liquid Chromatography/Mass Spectrophotometry (LC/MS) for determining the GABA and Taurine ratios relative to Glutamate, Dopamine, Norepinephrine, Epinephrine, and Serotonin. The ASST data revealed that Perinatal rats are negatively impacted by developmental Pb2+-exposures evidenced by increased TTC and ETC to learn the SD, ID, and ID-Rev with unique sex-based differences in frontoexecutive dysfunctions. Moreover, Perinatal+Taurine co-treated rats exhibited a recovery of the frontoexecutive dysfunctions observed in Perinatal rats to levels equivalent to Control rats across both sexes. The LC/MS data revealed altered brain sub-region specific patterns across the PrL, IL, OV, OVL, and HP in response to developmental Pb2+-exposure that produced an altered neurochemical signaling profile in a sex-dependent manner, which may underlie the observed frontoexecutive dysfunctions, cognitive inflexibility, and associated motivation deficits. When taurine co-treatment was administered concurrently for the duration of developmental Pb2+-exposure, the observed frontoexecutive dysfunctions were significantly reduced in both ASST task performance and neurochemical ratios that were comparable to Control levels for both sexes. Altogether, the data suggest that taurine co-treatment may facilitate neuroprotection, mitigate neurotransmitter excitability balancing, and perhaps ameliorate against neurotoxicant exposures in early development as a potential psychopharmacotherapy.


Assuntos
Atenção , Função Executiva , Chumbo/efeitos adversos , Exposição Materna/efeitos adversos , Taurina/farmacologia , Animais , Feminino , Aprendizagem , Masculino , Fármacos Neuroprotetores/farmacologia , Gravidez , Ratos , Ratos Long-Evans
7.
Adv Exp Med Biol ; 1155: 801-819, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31468449

RESUMO

Lead (Pb2+) is a developmental neurotoxicant that causes alterations in the brain's excitation-to-inhibition (E/I) balance. By increasing chloride concentration through GABA-ARs, taurine serves as an effective inhibitory compound for maintaining appropriate levels of brain excitability. Considering this pharmacological mechanism of taurine facilitated inhibition through the GABA-AR, the present pilot study sought to explore the anxiolytic potential of taurine derivatives. Treatment groups consisted of the following developmental Pb2+-exposures: Control (0 ppm) and Perinatal (150 ppm or 1000 ppm lead acetate in the drinking water). Rats were scheduled for behavioral tests between postnatal days (PND) 36-45 with random assignments to either solutions of Saline, Taurine, or Taurine Derived compounds (i.e., TD-101, TD-102, or TD-103) to assess the rats' responsiveness to each drug in mitigating the developmental Pb2+-exposure through the GABAergic system. Long Evans Hooded rats were assessed using an Open Field (OF) test for preliminary locomotor assessment. Approximately 24-h after the OF, the same rats were exposed to the Elevated Plus Maze (EPM) and were given an i.p. injection of 43 mg/Kg of the Saline, Taurine, or TD drugs 15-min prior to testing. Each rat was tested using the random assignment method for each pharmacological condition, which was conducted using a triple-blind procedure. The OF data revealed that locomotor activity was unaffected by Pb2+-exposure with no gender differences observed. However, Pb2+-exposure induced an anxiogenic response in the EPM, which interestingly, was ameliorated in a gender-specific manner in response to taurine and TD drugs. Female rats exhibited more anxiogenic behavior than the male rats; and as such, exhibited a greater degree of anxiety that were recovered in response to Taurine and its derivatives as a drug therapy. The results from the present psychopharmacological pilot study suggests that Taurine and its derivatives could provide useful data for further exploring the pharmacological mechanisms and actions of Taurine and the associated GABAergic receptor properties by which these compounds alleviate anxiety as a potential behavioral pharmacotherapy for treating anxiety and other associated mood disorders.


Assuntos
Ansiolíticos/farmacologia , Ansiedade/tratamento farmacológico , Chumbo/efeitos adversos , Exposição Materna/efeitos adversos , Taurina/farmacologia , Animais , Feminino , Masculino , Projetos Piloto , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Distribuição Aleatória , Ratos , Ratos Long-Evans
8.
J Fluoresc ; 28(1): 311-321, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29116608

RESUMO

A series of fluorescent donor- acceptor (D-A) alternating copolyimides (P1, P2, P3 and P4) with 4-quinolin-8-yloxy linked triphenylamine main polymer chain have been synthesized by conventional polycondensation. All the synthesized co-polyimides were characterized by elemental, gel permeation chromatography and FTIR spectral analysis. These newly prepared PIs possess HOMO energy levels in range of - 4.74 to - 4.78 eV and have medium optical band gaps. The photoluminescence spectral analysis revealed blue to violet emission with appreciable efficiency with lower onset oxidation potentials suitable for the facile hole injection materials. All the photophysical and electrochemical properties were also explored in context of effect of the pendant 4- quinolin-8-yloxy, indicating suitable combination of donor (TPA) on one hand and imide and pendant as acceptor on both ends.Graphical Abstract.

9.
Dis Aquat Organ ; 130(3): 165-175, 2018 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-30259869

RESUMO

The St. Lawrence Estuary (SLE) beluga Delphinapterus leucas in Quebec, Canada, is endangered due to intensive hunting in the 19th and 20th centuries and subsequent anthropogenic contamination and human activities in the region. Infectious disease is a primary cause of death in this population. The protozoan parasite Toxoplasma gondii is reported in numerous marine mammal species, including beluga. In the present study, 55 tissue samples (heart and brain) collected from 34 stranded SLE beluga were analysed by PCR followed by DNA sequencing and restriction fragment length polymorphism analysis (RFLP) to determine the PCR prevalence and genotypes of T. gondii in these beluga. Of 34 beluga tested, 44% were positive for T. gondii by PCR, with males having a higher prevalence of infection than females and with more infected neonates and juveniles than adults. Molecular analyses indicated that all T. gondii infecting stranded SLE beluga grouped into genotype II, which predominates in humans. While our results indicate that a high prevalence of stranded beluga are PCR-positive for T. gondii infection, very few deaths are attributed to toxoplasmosis based on published necropsy results. Toxoplasma gondii can cause a range of diseases, including neurological deficits, and more data are needed to investigate this parasite's effect on population recovery.


Assuntos
Beluga , Estuários , Toxoplasma , Toxoplasmose Animal , Animais , Beluga/parasitologia , Canadá , Feminino , Gelatina , Genótipo , Masculino , Polimorfismo de Fragmento de Restrição , Quebeque , Toxoplasma/isolamento & purificação
10.
J Fluoresc ; 27(6): 2177-2186, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28812233

RESUMO

A series of poly(azomethine)s (PAMs) were synthesized from N1-(4-aminophenyl)-N1-(4-phenoxyphenyl)benzene-1,4-diamine (DA) and various dialdehydes to investigate the influence of structure of polymer chain and triphenylamine-based phenoxy pendant group on the optoelectronic properties. The structural characterization of the resulting poly(azomethine)s was carried out by solubility test, gel permeation chromatography, viscosity measurement, fourier transform infrared (FTIR) spectral and CHN elemental analysis. The photophysical and electrochemical properties of the materials were scrutinized by UV-vis, photoluminescence, time correlation photon counting spectral analysis (TCSP) and cyclic voltammetry. The thermal stability of the poly(azomethine)s was assessed by differential scanning calorimetry and thermogravimetric analysis found to be stable upto 300 °C. These polymers exhibit moderate inherent viscosity range from 0.99 to 1.15 g dL- 1 and appreciable organosolubility. The presence of triphenylamine and azomethine (CH = N) linkage in our synthesized materials rendered them fluorescent, emitting green light upon excitation at 375 nm with quantum efficiencies of 3.9-8.5%. The pendant phenoxy group at para-position in new poly(azomethine)s has also lowered the onset oxidation potentials and elevated the HOMO levels. Additionally, the presence of conjugation increases the fluorescence time of the excited state in conjugated polymers which was found in the range 9.22-11.17 ns, sufficient to be use in future optoelectronic applications.

11.
Int J Surg Case Rep ; 116: 109342, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38342030

RESUMO

INTRODUCTION AND IMPORTANCE: Central giant cell tumor (CGCT) of bone is an uncommon yet locally aggressive neoplasm originating from undifferentiated mesenchymal cells in bone marrow. This case report explores a rare presentation in the maxilla extending to the mandible, emphasizing the complexity of CGCT management and the need for a multidisciplinary approach. CASE PRESENTATION: A 35-year-old female presented with a progressively enlarging non-tender, firm swelling on the left maxilla and a similar mandibular swelling. Paraesthesia of the left lower lip and chin accompanied the mandibular swelling. CT scans and 3D reconstructions revealed expansive osteolytic defects affecting the maxilla and mandible. Biochemical tests supported a central giant cell tumor diagnosis. Histopathology confirmed spindle cell proliferation and multinucleated giant cells in both lesions. Surgical intervention involved excision and reconstruction. A five-month follow-up showed no recurrence, affirming the treatment's success. CLINICAL DISCUSSION: Central giant cell tumors (CGCTs) of bone are primarily benign, arising from undifferentiated mesenchymal cells. While mostly benign, they carry a rare potential for malignancy. Diagnosis involves imaging (CT, MRI, bone scintigraphy) and confirmation through biopsy. Surgical resection is the standard treatment, with radiotherapy considered in challenging cases. Recurrence rates vary with the extent of surgical intervention. Alternative treatments like cryotherapy and chemotherapy show varying success. CONCLUSION: This case emphasizes the necessity of precise histopathological diagnosis for CGCT management. The intricate nature of maxillary involvement, coupled with mandibular association, mandates a multidisciplinary approach. Surgery, while the primary treatment, should be judiciously determined based on tumor characteristics and recurrence.

12.
Chemosphere ; 352: 141434, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38401867

RESUMO

Ionic liquids (ILs) are a class of liquid salts with characteristics such as a low melting point, an ionic nature, non-volatility, and tunable properties. Because of their adaptability, they have a significant influence in the field of fluorescence. This paper reviews the primary literature on the use of ILs in fluorescence sensing technologies. The kind of target material is utilized to classify the fluorescence sensors made with the use of ILs. They include using ILs as probes for metals, nitro explosives, small organic compounds, anions, and gases. The efficacy of an IL-based fluorescence sensor depends on the precise design to guarantee specificity, sensitivity, and a consistent reaction to the desired analyte. The precise method can differ depending on the chemical properties of the IL, the choice of fluorophore, and the interactions with the analyte. Overall, the viability of the aforementioned materials for chemical analysis is evaluated, and prospective possibilities for further development are identified.


Assuntos
Líquidos Iônicos , Líquidos Iônicos/química , Estudos Prospectivos , Íons , Ânions , Gases , Corantes
13.
ACS Appl Mater Interfaces ; 16(19): 25090-25100, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38709646

RESUMO

The selective electrocatalytic reduction of nitrobenzene (NB) to aniline demands a desirable cathodic catalyst to overcome the challenges of the competing hydrogen evolution reaction (HER), a higher overpotential, and a lower selectivity. Here, we deposit Co-doped 1T MoS2 on Ti mesh by the solvothermal method with different doping percentages of Co as x % Co-MoS2 (where x = 3, 5, 8, 10, and 12%). Because of the lowest overpotential, lower charge-transfer resistance, strong suppression of the competing HER, and higher electrochemical surface area, 8% Co-MoS2 achieves 94% selectivity of aniline with 54% faradaic efficiency. The reduction process follows first-order dynamics with a reaction coefficient of 0.5 h-1. Besides, 8% Co-MoS2 is highly stable and retains 81% selectivity even after 8 cycles. Mechanistic studies showed that the selective and exothermic adsorption of the nitro group at x % Co-MoS2 leads to a higher rate of NB reduction and higher selectivity of aniline. The aniline product is successfully removed from the solution by polymerization at FTO. This study signifies the impact of doping metal atoms in tuning the electronic arrangement of 1T-MoS2 for the facilitation of organic transformations.

14.
Acta Crystallogr Sect E Struct Rep Online ; 69(Pt 1): o96, 2013 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23476475

RESUMO

The aromatic rings in the title compound, C13H8ClNO4, enclose a dihedral angle of 39.53 (3)°. The nitro group is almost coplanar with the ring to which it is attached [dihedral angle = 4.31 (1)°]. In the crystal, mol-ecules are connected by C-H⋯O hydrogen bonds into chains running along [001].

15.
Int J Surg Case Rep ; 111: 108894, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37812957

RESUMO

INTRODUCTION AND IMPORTANCE: Lobular capillary hemangioma (LCH) is a benign vascular lesion typically affecting the head and neck region, especially the nasal cavity. However, its occurrence in the nasal cavity of the pediatric population is rare, making its diagnosis and management crucial in such cases. CASE PRESENTATION: A 7-year-old female presented with left-sided nasal obstruction and recurrent epistaxis for 4 months. Examination revealed a dark purplish-red nasal mass, which bled easily upon probing. CT scans showed a soft tissue lesion with post-contrast enhancement. Histopathological examination confirmed lobular capillary hemangioma. The patient successfully underwent surgical excision without pre-operative embolization. CLINICAL DISCUSSION: LCH affects both the skin and mucous membranes. Although its exact etiology remains debated, trauma is a leading risk factor for its development. Biopsy and radiological investigations confirm its diagnosis. Differentiating LCH from other vascular disorders with similar presentations is essential for a thorough understanding and better management. Endoscopic surgical excision combined with electrodesiccation is the treatment of choice. CONCLUSION: Intranasal LCH in children is infrequent. An accurate diagnosis is essential for a comprehensive understanding. Surgical excision with electrodesiccation is the preferred treatment, but the role of pre-operative embolization is still under discussion.

16.
Chemosphere ; 307(Pt 4): 135846, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35952790

RESUMO

The hazardous nature of certain azeotropic mixtures has urged the researchers to explore the separation techniques which can impart a contamination free environment. Despite of causing environmental concerns, these azeotropic mixtures are responsible for causing serious health issues to humans and animals. More specifically, in this article, we have taken Tetrahydrofuran (THF) - water azeotropic mixture into consideration. It has been reported that it affects the central nervous system, liver, as well as can cause carcinogenicity. To be more precise, in this article, two different entrainers has been evaluated on their merits of exploiting liquid-liquid phase envelope for separating Tetrahydrofuran-water binary azeotropic mixture. The process flow sheet schematic with n-octane as entrainer (having two distillation regions) has a reduced operating energy requirement by 21.11% while comparing with the Residue Curve Map of n-hexane as entrainer having three distillation regions. The total capital cost for THF-water-n-octane case has been found to be 7.1 $/y × 105 and that of THF-water-n-hexane case has been found to be 9 $/y × 105. However, in both of the cases, the product purity of 99.9% has been achieved for THF. Also, the classical trade-off between capital cost and energy cost has been shown in this study. The salient feature of this work is the use of dynamic simulation to understand the effect of recycle flow rate induced process operational in-feasibility due to distillation region shift.


Assuntos
Destilação , Água , Animais , Análise Custo-Benefício , Destilação/métodos , Furanos , Hexanos , Humanos , Octanos
17.
RSC Adv ; 12(3): 1682-1693, 2022 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-35425209

RESUMO

This study reports the synthesis, characterization, and mercuric ion detection ability of novel tribenzamides having flexible and rigid moieties. N-{4-[2-(1,3-Benzoxazolyl)]phenyl}-3,5-N,N'-bis(4-alkyloxybenzoyl)benzamides (TBa-TBc) were synthesized from newly synthesized diamine, N-(1,3-benzoxazol-2-yl-phenyl)-3,5-diaminobenzamide (BODA) and p-alkoxybenzoic acids (p-ABA) by amidation reaction. Structural characterization of the synthesized compounds was done through spectroscopic techniques (FT-IR and NMR). The synthesized tribenzamides along with silver nanoparticles were used for modification of a glassy carbon electrode. Square wave anodic stripping voltammetry was carried out to test the performance of the modified electrode for mercuric ion detection. The designed sensor was found to demonstrate the qualities of sensitivity, selectivity, reproducibility and anti-interference ability. The sensing platform helped in detecting femtomolar concentrations of mercuric ions which are much below the level declared toxic by the World Health Organization.

18.
ChemSusChem ; 15(3): e202102596, 2022 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-34927792

RESUMO

The gram-scale selective oxidation of biomass-based chemicals, in particular 5-hydroxymethylfurfural (HMF), into value-added 2,5-diformylfuran (DFF) has a high application potential but suffers from high cost, low selectivity, and harsh reaction conditions. Besides, the electrooxidation strategy requires the usage of expensive electrodes and struggles with low selectivity and efficiency, which restricts its further scaled-up application. In this regard, a continuous-flow system was developed through redox mediator I- /I2 for the efficient synthesis of DFF, which could accelerate the mass transfer of I- (I2 ) to aqueous (organic) phase and avoid over-oxidation to achieve high selectivity. After the solvent system, iodine concentration, and reaction time were optimized, highly efficient DFF synthesis (selectivity >99 %) could be achieved in the electrochemical flow system using inexpensive graphite felt (GF) as electrode. Moreover, selective HMF oxidation was paired with the hydrogen evolution reaction with increased efficiency after using in-situ-loaded GF-CoS2 /CoS and GF-Pt electrodes. As a result, the required energy to achieve the gram-scale synthesis of DFF was significantly reduced, demonstrating outstanding potential for large-scale production of the target product.


Assuntos
Furanos , Biomassa , Catálise , Oxirredução
19.
Nanomicro Lett ; 13(1): 54, 2021 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-34138199

RESUMO

Huge volume changes of Si during lithiation/delithiation lead to regeneration of solid-electrolyte interphase (SEI) and consume electrolyte. In this article, γ-glycidoxypropyl trimethoxysilane (GOPS) was incorporated in Si/PEDOT:PSS electrodes to construct a flexible and conductive artificial SEI, effectively suppressing the consumption of electrolyte. The optimized electrode can maintain 1000 mAh g-1 for nearly 800 cycles under limited electrolyte compared with 40 cycles of the electrodes without GOPS. Also, the optimized electrode exhibits excellent rate capability. The use of GOPS greatly improves the interface compatibility between Si and PEDOT:PSS. XPS Ar+ etching depth analysis proved that the addition of GOPS is conducive to forming a more stable SEI. A full battery assembled with NCM 523 cathode delivers a high energy density of 520 Wh kg-1, offering good stability.

20.
ACS Appl Mater Interfaces ; 12(17): 19431-19438, 2020 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-32255340

RESUMO

PEDOT: PSS has been studied as a silicon-based binder due to its inherent superior electricity and electrochemical stability. However, it cannot effectively alleviate the huge volume changes of silicon during lithiation/delithiation due to its linear structure, resulting in poor cycling stability. Ion-cross-linking is a usual method to cross-link linear polymers into 3D structures. In this paper, multivalent cations of the 5th period and Group 2 cross-linked PEDOT:PSS were applied as silicon anode binders and studied systematically. It was found that the variation trend of viscosity and conductivity of PEDOT:PSS after cross-linking was consistent with that of ionic potential and softness parameters of multivalent cations. The mesostructure of a binder after cross-linking is influenced by the solubility product constant of sulfites or hydroxides of cations and the growth characteristics of crystals. An Sn4+-cross-linked binder displayed increased viscosity and electrical conductivity and higher reduced modulus and hardness due to its positive softness parameter and higher ion potential. The Si electrode with the Sn4+-cross-linked binder showed improved cycling stability (1876.4 mAh g-1 compared with 1068.4 mAh g-1 of the electrode with the pure PEDOT:PSS binder after 100 cycles) and superior rate capability (∼800 mAh g-1 at an ultrahigh current density of 8.0 A g-1).

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