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1.
J Colloid Interface Sci ; 645: 906-917, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37178567

RESUMO

HYPOTHESIS: Fluidic micelles and reverse micelles have served as exfoliation mediums. However, an additional force, such as extended sonication, is required. Gelatinous cylindrical micelles that are formed once desired conditions are achieved can be an ideal medium for the quick exfoliation of 2D materials without the need for any external force. The quick formation of gelatinous cylindrical micelles can rip off layers from the 2D materials suspended in the mixture leading to the quick exfoliation of 2D materials. EXPERIMENTS: Herein, we introduce a quick universal method capable of delivering high-quality exfoliated 2D materials cost-effectively using CTAB-based gelatinous micelles as an exfoliation medium. The approach is devoid of harsh treatment, such as prolonged sonication and heating, and a quick exfoliation of 2D materials is completed using this approach. FINDINGS: We successfully exfoliated four 2D materials (MoS2, Graphene, WS2, and BN) and investigated their morphology, chemical, and crystal structure along with optical and electrochemical properties to probe the quality of the exfoliated product. Results revealed that the proposed method is highly efficient in exfoliating 2D materials in a quick time without causing any significant damage to the mechanical integrity of the exfoliated materials.

2.
ACS Appl Mater Interfaces ; 12(9): 11144-11154, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32017523

RESUMO

A facile vapor-based etching method is introduced to design surfaces with underwater wettability contrast. The method involves exposure of the masked copper surface to acetic acid vapors for growing nano- and microstructures; additional modification with stearic acid (STA) produced a superhydrophobic exposed area, while the masked surface remained hydrophobic. Dot- as well dumbbell-shaped patterns were prepared and used for oil drop storage and transfer, respectively. The influence of buoyancy on the storage capacity of the dot patterns and transfer rate of the channels is investigated. Buoyancy-driven partial channel-less transport of oil droplets by using a strategic arrangement of donor and receptor channels is also demonstrated. Patterns are also designed on flexible substrates to enable easy fabrication of complex three-dimensional fluidic pathways having both horizontal and vertical tracks. The flexibility of the substrates enabled the design of an electric switch-type configuration for the oil drop transport between two channels. In the end, a strategy for the removal of water from a water-in-oil emulsion using channels is introduced. A unique phenomenon of spontaneous bursting out of a water drop from inside an oil drop is also demonstrated.

3.
J Colloid Interface Sci ; 474: 41-50, 2016 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-27093455

RESUMO

Gel is an intermediate phase of solid and liquid, which exhibits properties of both, and this unique feature of gel has made it an excellent choice as a reaction medium for the nanomaterials synthesis. Herein, we report use of oil swollen surfactant gels as reaction medium and exfoliation medium, for the synthesis of metals (Au, Ag) nanoparticles and graphene, respectively. Confined growth of metals (Au and Ag) nanoparticles, has been achieved by exploring tween 80 based surfactant gel as a reaction medium. Au NPs prepared within tween 80 gel were found to be spherical with size ∼5nm, arranged in template micelles. Heating triggered the growth of Au nanoparticles and particles of various shapes including triangles, rods and pentagonal, were produced. Au and Ag containing tween 80 gels were found to be promising as catalysts for the nitrophenol reduction. Apart from separate synthesis of Au and Ag nanoparticles, bimetallic (Au-Ag) nanoparticles have also been synthesized by taking advantage of selective reducing property of tween 80. First time CTAB gel has been utilized as an exfoliation medium for the quick exfoliation of graphite into graphene sheets, eliminating the necessity of any external driving force such as sonication or heating, to reinforce exfoliation.

4.
J Lipids ; 2015: 971453, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25949827

RESUMO

Present review article highlights various cardiovascular risk prediction biomarkers by incorporating both traditional risk factors to be used as diagnostic markers and recent technologically generated diagnostic and therapeutic markers. This paper explains traditional biomarkers such as lipid profile, glucose, and hormone level and physiological biomarkers based on measurement of levels of important biomolecules such as serum ferritin, triglyceride to HDLp (high density lipoproteins) ratio, lipophorin-cholesterol ratio, lipid-lipophorin ratio, LDL cholesterol level, HDLp and apolipoprotein levels, lipophorins and LTPs ratio, sphingolipids, Omega-3 Index, and ST2 level. In addition, immunohistochemical, oxidative stress, inflammatory, anatomical, imaging, genetic, and therapeutic biomarkers have been explained in detail with their investigational specifications. Many of these biomarkers, alone or in combination, can play important role in prediction of risks, its types, and status of morbidity. As emerging risks are found to be affiliated with minor and microlevel factors and its diagnosis at an earlier stage could find CVD, hence, there is an urgent need of new more authentic, appropriate, and reliable diagnostic and therapeutic markers to confirm disease well in time to start the clinical aid to the patients. Present review aims to discuss new emerging biomarkers that could facilitate more authentic and fast diagnosis of CVDs, HF (heart failures), and various lipid abnormalities and disorders in the future.

5.
Biomed Res Int ; 2014: 869269, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25136634

RESUMO

Present review highlights various drug delivery systems used for delivery of pharmaceutical agents mainly antibiotics, antineoplastic agents, neuropeptides, and other therapeutic substances through the endothelial capillaries (BBB) for CNS therapeutics. In addition, the use of ultrasound in delivery of therapeutic agents/biomolecules such as proline rich peptides, prodrugs, radiopharmaceuticals, proteins, immunoglobulins, and chimeric peptides to the target sites in deep tissue locations inside tumor sites of brain has been explained. In addition, therapeutic applications of various types of nanoparticles such as chitosan based nanomers, dendrimers, carbon nanotubes, niosomes, beta cyclodextrin carriers, cholesterol mediated cationic solid lipid nanoparticles, colloidal drug carriers, liposomes, and micelles have been discussed with their recent advancements. Emphasis has been given on the need of physiological and therapeutic optimization of existing drug delivery methods and their carriers to deliver therapeutic amount of drug into the brain for treatment of various neurological diseases and disorders. Further, strong recommendations are being made to develop nanosized drug carriers/vehicles and noninvasive therapeutic alternatives of conventional methods for better therapeutics of CNS related diseases. Hence, there is an urgent need to design nontoxic biocompatible drugs and develop noninvasive delivery methods to check posttreatment clinical fatalities in neuropatients which occur due to existing highly toxic invasive drugs and treatment methods.


Assuntos
Barreira Hematoencefálica/efeitos dos fármacos , Doenças do Sistema Nervoso Central/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Nanopartículas/administração & dosagem , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Doenças do Sistema Nervoso Central/patologia , Quitosana/administração & dosagem , Quitosana/química , Humanos , Lipossomos/administração & dosagem , Lipossomos/química , Nanopartículas/química
6.
Int Sch Res Notices ; 2014: 309404, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-27355037

RESUMO

Present review paper highlights role of BBB in endothelial transport of various substances into the brain. More specifically, permeability functions of BBB in transendothelial transport of various substances such as metabolic fuels, ethanol, amino acids, proteins, peptides, lipids, vitamins, neurotransmitters, monocarbxylic acids, gases, water, and minerals in the peripheral circulation and into the brain have been widely explained. In addition, roles of various receptors, ATP powered pumps, channels, and transporters in transport of vital molecules in maintenance of homeostasis and normal body functions have been described in detail. Major role of integral membrane proteins, carriers, or transporters in drug transport is highlighted. Both diffusion and carrier mediated transport mechanisms which facilitate molecular trafficking through transcellular route to maintain influx and outflux of important nutrients and metabolic substances are elucidated. Present review paper aims to emphasize role of important transport systems with their recent advancements in CNS protection mainly for providing a rapid clinical aid to patients. This review also suggests requirement of new well-designed therapeutic strategies mainly potential techniques, appropriate drug formulations, and new transport systems for quick, easy, and safe delivery of drugs across blood brain barrier to save the life of tumor and virus infected patients.

7.
J Colloid Interface Sci ; 342(2): 327-32, 2010 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-19942226

RESUMO

For the first time, single reverse microemulsion-assisted direct precipitation route has been successfully used to synthesize tetragonal zirconia nanoparticles in narrow size range. The synthesized powder was characterized using FT-IR, XRD and HRTEM techniques. The zirconia nanoparticles obtained were spherical in shape and has narrow particle size distribution in the range of 13-31nm and crystallite size in the range of 13-23nm.

8.
J Appl Toxicol ; 28(7): 874-84, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18418845

RESUMO

The toxic effects of Asian black scorpion Heterometrus fastigiousus (Family, Scorpionidae) venom were determined in albino mice (NIH strain). Venom was isolated and fractioned by Sepharose CL-6B column chromatography. The toxicity of fractioned venom was determined in albino mice by subcutaneous envenomation. The LD(50) of venom was found to be 15 mg kg(-1) body weight and range of molecular weight of venom proteins responsible for toxicity was found from 9.5-63 kDs. The effects of fractioned venom on different biochemical and enzymatic parameters in blood serum and gastrocnemius muscle tissue of albino mice were determined after experimental envenomation. An increase in serum levels of glucose, free amino acids, uric acid, pyruvic acid and total protein was observed while a decrease in the cholesterol level in serum was observed after 4 h of envenomation. Increase in alkaline phosphatase (ALP), acid phosphatase (ACP), lactic dehydrogenase (LDH) and glutamate-pyruvate transaminase (GPT) enzyme activity in serum was observed. Glycogen content in liver, atria, ventricle, rectus abdominus and gastrocnemius muscle was decreased after experimental envenomation. Activity of ALP, ACP, LDH, GPT, AChE and Na+K+ATPase enzymes in gastrocnemius muscle tissue of envenomed albino mice was studied. Inhibition in ALP, AChE and Na+K+ATPase enzyme activity and increase in ACP, LDH and GPT enzyme activity was observed in gastrocnemius muscle after scorpion envenomation. In vitro studies with AChE and Na+K+ATPase enzymes indicated that enzymatic activity of AChE was inhibited competitively by fractioned venom in gastrocnemius muscle.


Assuntos
Mordeduras e Picadas/sangue , Inibidores Enzimáticos/toxicidade , Enzimas/sangue , Venenos de Escorpião/toxicidade , Escorpiões/fisiologia , Animais , Biomarcadores/metabolismo , Mordeduras e Picadas/etiologia , Fracionamento Químico , Testes de Química Clínica , Modelos Animais de Doenças , Inibidores Enzimáticos/química , Glicogênio/análise , Camundongos , Camundongos Endogâmicos , Músculo Esquelético/química , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/enzimologia , Venenos de Escorpião/química , Escorpiões/química
9.
Indian J Exp Biol ; 40(2): 151-61, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12622177

RESUMO

Absorption and transport of 3H cholesterol from the midgut to hemolymph and other tissues was studied in the locusts Schistocerca gregaria and Locusta migratoria. S. gregaria are able to absorb dietary cholesterol in the midgut and release into the hemolymph in vivo and into the incubation medium in virto. Certain proteins of midgut origin are involved in the absorption and release of cholesterol. The proteins designated as cholesterol binding proteins (CBP's) were fractionated by gel filtration chromatography using Sepharose CL-6B-200 column. Presence of a protein and its binding with cholesterol is confirmed by TCA precipitation after subsequent incubation of midgut in the incubation medium. Cholesterol binding with the proteins was also confirmed in native polyacrylamide gel electrophoresis. Biosynthesis of this protein takes place in the midgut which is inhibited by a protein synthesis inhibitor, cycloheximide. It also inhibits absorption and release of cholesterol from the midgut. The cholesterol binding activity was associated with a peak containing proteins ranging from molecular weights of 17-32 kDa in SDS-PAGE gels. Treatment of midgut with cycloheximide resulted in reduced cholesterol binding activity. Dilipidation of mucin and transport in presence of bile salts yielded a higher cholesterol binding activity. Although the absorption and release of cholesterol was observed in the hemolymph of both sexes, the ovary exhibited higher cholesterol binding as compared to testis.


Assuntos
Colesterol/metabolismo , Animais , Cromatografia/métodos , Cicloeximida/farmacologia , Eletroforese em Gel de Poliacrilamida , Feminino , Gafanhotos , Hemolinfa/metabolismo , Masculino , Ovário/metabolismo , Ligação Proteica , Inibidores da Síntese de Proteínas/farmacologia , Sefarose/farmacologia , Testículo/metabolismo , Fatores de Tempo , Ultracentrifugação
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