inert carrier
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Author(s):  
Michael Zelenski ◽  
Yuri Taran ◽  
Alina Korneeva ◽  
Fedor Sandalov ◽  
Nikolai Nekrylov

Volcanic fumaroles are openings in the earth's surface, where volcanic gases discharge to the atmosphere. Metallic and non-metallic elements contained in gases form specific mineral precipitates upon cooling. Although the presence of metals in fumarolic gases has long been known, their concentrations are generally low and difficult to measure directly. A laboratory model of a fumarole may resolve the situation if the complex gas composition could be accurately reproduced. Here we describe a new experimental approach that allows accurately simulating fumarolic gases in terms of their main components (H2O, CO2, S, HCl), as well as adding volatile metal compounds. Gas is generated inside a special flow-through reactor, at the outlet of which the elements contained in the gas form temperature-dependent mineral sequence inside the attached silica-glass tube. Using this installation, we obtained laboratory sublimates from reducing (H2S-rich) gases similar to natural ones in terms of mineral composition and mineral habits. Twenty-one phases have been identified in sublimates, among which are simple and complex chlorides, simple sulfides and six sulfosalts. Comparison of the sublimate deposition from H2O-rich gas at 1 bar with similar works performed in evacuated ampoules at low pressure showed that fumarolic gases behave like an ideal gas, in which molecules do not interact with each other, and reactive compounds in the gas serve in fact as an inert carrier of volatile metals species. Changing the composition of the gas at the outlet of the installation, its flow rate and temperature, we can observe the corresponding changes in mineral precipitates and in such a way study the factors affecting mineral formation on natural fumarolic fields.


2021 ◽  
Vol 24 (4) ◽  
pp. 348-355
Author(s):  
A. L. Pushkarchuk ◽  
S. A. Kuten ◽  
S. Ya. Kilin ◽  
A. P. Nizovtsev ◽  
V. A. Pushkarchuk ◽  
...  

To estimate possible biological activity of conjugates based on nanodiamond with an NV center inside (ND[NV]), with various functional groups located on its surface, their structural, electronic, and spin properties were calculated using the PM6 method. The energy gap between HOMO and LUMO of the complex was used as a main indicator of biological activity. It has been shown that complexes with OH or H groups attached to the (111) surface are most stable in an aqueous medium. Analysis of spin density and HOMO and LUMO localization shows that complexes ND[NV] may be not just an inert carrier of a biologically active drug or means of visualizing drug delivery, but are also directly involved in the formation of the biological activity of the conjugate.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lidia Martínez ◽  
Pablo Merino ◽  
Gonzalo Santoro ◽  
José I. Martínez ◽  
Stergios Katsanoulis ◽  
...  

AbstractDevelopment of sustainable processes for hydrocarbons synthesis is a fundamental challenge in chemistry since these are of unquestionable importance for the production of many essential synthetic chemicals, materials and carbon-based fuels. Current industrial processes rely on non-abundant metal catalysts, temperatures of hundreds of Celsius and pressures of tens of bars. We propose an alternative gas phase process under mild reaction conditions using only atomic carbon, molecular hydrogen and an inert carrier gas. We demonstrate that the presence of CH2 and H radicals leads to efficient C-C chain growth, producing micron-length fibres of unbranched alkanes with an average length distribution between C23-C33. Ab-initio calculations uncover a thermodynamically favourable methylene coupling process on the surface of carbonaceous nanoparticles, which is kinematically facilitated by a trap-and-release mechanism of the reactants and nanoparticles that is confirmed by a steady incompressible flow simulation. This work could lead to future alternative sustainable synthetic routes to critical alkane-based chemicals or fuels.


2021 ◽  
Vol 3 (2) ◽  
pp. 86-98
Author(s):  
Noval Noval ◽  
◽  
Rosyifa Rosyifa ◽  

Diclofenac sodium is included in class II category based on biopharmaceutics classification system (BCS), sodium diclofenac has low solubility and high permeability. Low solubility will affect absorption of drugs in body because rate of dissolution will decrease. PVP K30 is inert carrier that dissolves easily in water and can affect solubility of an active drug substance. To know solid dispersion system increasing dissolution rate of sodium diclofenac by adding variations concentration of PVP K30. Solid dispersion uses solvent method with variations concentration of PVP K30 1:3, 1:5, 1:7 and 1:9. Test physical properties of solid dispersions using a moisture test and compressibility. Solid dispersion dissolution test using type 2 dissolutions test and determination of concentration using UV-VIS spectrophotometry. Test results were analyzed using One Way ANOVA and continued test. Solid dispersion has a good physical whit moisture percentage not >5% and compressibility not >20%. Solid dispersion of sodium diclofenac with addition of PVP K30 can increase dissolution rate compared to pure sodium diclofenac (p<0,05) with highest at ratio 1:7. Each comparison has significant difference (p<0,05) expect in ratio 1:9. Solid dispersion of sodium diclofenac with PVP K30 can increase dissolution rate of pure sodium diclofenac.


2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Heng Mei ◽  
Jing Li ◽  
Shengsheng Cai ◽  
Xuequan Zhang ◽  
Wenqiang Shi ◽  
...  

Abstract Unsatisfactory drug loading capability, potential toxicity of the inert carrier and the limited therapeutic effect of a single chemotherapy drug are all vital inhibitory factors of carrier-assisted drug delivery systems for chemotherapy. To address the above obstacles, a series of carrier-free nanoplatforms self-assembled by dual-drug conjugates was constructed to reinforce chemotherapy against tumors by simultaneously disrupting intratumoral DNA activity and inhibiting mitochondria function. In this nanoplatform, the mitochondria-targeting small-molecular drug, α-tocopheryl succinate (TOS), firstly self-assembled into nanoparticles, which then were used as the carrier to conjugate cisplatin (CDDP). Systematic characterization results showed that this nanoplatform exhibited suitable particle size and a negative surface charge with good stability in physicochemical environments, as well as pH-sensitive drug release and efficient cellular uptake. Due to the combined effects of reactive oxygen species (ROS) generation by TOS and DNA damage by CDDP, the developed nanoplatform could induce mitochondrial dysfunction and elevated cell apoptosis, resulting in highly efficient anti-tumor outcomes in vitro. Collectively, the combined design principles adopted for carrier-free nanodrugs construction in this study aimed at targeting different intracellular organelles for facilitating ROS production and DNA disruption can be extended to other carrier-free nanodrugs-dependent therapeutic systems.


2021 ◽  
pp. 134-138
Author(s):  
Praveen Kumar Shakya ◽  
Sanjesh Kumar ◽  
Mansi Singh ◽  
Savita Savita

Telmisartan (TLM) is an angiotensin II receptor antagonist used in the treatment of hypertension. Telmesartan (TLM) is an orally active direct-acting Angiotensin1receptor antagonist and possess therapeutic potential in the pharmacotherapy of hypertension. Telmisartan is classified as a class II medicine by the BCS (biopharmaceutical categorization system), and it is nearly insoluble in water, with a low solubility profile and poor absorption. Drugs with poor aqueous solubility are still an ongoing challenge in the successful formulation of therapeutic products due to their low oral bioavailability. Solid dispersions are a dispersion mixture of one or more active ingredients in an inert carrier at the solid state prepared by melting, solvent, solvent-melting or other methods. Cyclodextrins(CDs) with their cylinder-shaped cavities are capable to form inclusion complexes with a wide range of commonly used drugs. Complexation of molecules to CDs occurs through a non-covalent interaction between the molecule and the CD cavity. This is a dynamic process whereby the guest molecule continuously associates and dissociates from the host CD. The present study is to improve the solubility of Telmisartan by solid dispersion techniques using various methods and proved to be effective for further pharmaceutical usage.


Author(s):  
R. Matura ◽  
V. Bahuguna ◽  
M. Bhandari ◽  
I. Thapa ◽  
S. Jain

Background: Bio-fertilizers are the substances which contain living microorganisms, when applied to soil, seeds and plant root these fertilizers increases soil fertility and promote growth of the plant. Biofertilizers help plants to utilize important mineral resources, phosphorous and nitrogen. Microorganisms like Rhizobacteria, fungi and algae which provide nutrient to the soil and which are produced commercially are known as biofertilizers. The microorganisms which present in biofertilizers are Rhizobium species, Pseudomonas species and Azospirillum species etc. These biofertilizers have potential to replace conventional chemical fertilizers. The quality of biofertilizers is utmost important as they have to be used by farmers and should work well when applied to the soil. It should not form clumps after preparation. In this study, anticaking property provided by tricalcium phosphate (TCP) to individual biofertilizer containing Pseudomonas, Rhizobium and Azospirillum respectively (each separately) was studied. Methods: In our study, we have used serial dilution and direct count method (CFU) for checking viability of live microorganism for 15, 30 and 90 days duration in respective biofertilizers in our laboratory. Different percentage viz 5%, 10%, 15% and 20% of tricalcium phosphate (TCP) was used in addition to aluminium silicate as an inert carrier.Conclusion: Our study has validated that all percentage (5%, 10%, 15% and 20%) of tricalcium phosphate (TCP) is reducing clump formation as compared to control with no TCP added. On the basis of plate count method (CFU result) 10% TCP is found to be optimum to be used as an anticaking agent for biofertilizer containing Pseudomonas, Rhizobium and Azospirillum respectively.


2021 ◽  
pp. 112-119
Author(s):  
A.V. Alekseev ◽  
◽  
T.N. Pahomkina ◽  
Yu.V. Lapshina ◽  
◽  
...  

The determination of gas-forming impurities in samples of low-alloyed copper alloys of the Cu–Cr and Cu–Cr–Zr systems is carried out. The content of sulfur and carbon was determined by the method of combustion in an induction furnace of a gas analyzer with subsequent detection in the infrared cell of the spectrometer, and to determine oxygen and nitrogen, the method of reducing melting in a flow of an inert carrier gas was used, followed by the detection of oxygen in the infrared cell and nitrogen in the conductometric cell of the gas analyzer.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1063
Author(s):  
Yingxi Zhang ◽  
Yuan Gao ◽  
Xiaoxiao Du ◽  
Rou Guan ◽  
Zhonggui He ◽  
...  

It is crucial to improve poorly water-soluble orally administered drugs through both preclinical and therapeutic drug discovery. A co-amorphous formulation consisting of two low molecular weight (MW) molecules offers a solubility/dissolubility advantage over its crystalline form by maintaining their amorphous status. Here, we report on a co-amorphous solid dispersion (SD) system that includes inert carriers (lactose monohydrate or microcrystalline cellulose) and co-amorphous sacubitril (SAC)-valsartan (VAL) using the spray drying process. The strong molecular interactions between drugs were the driving force for forming robust co-amorphous SDs. Our system provided the highest solubility with more than ~11.5- and 3.12-times solubility increases when compared with the physical mixtures. Co-amorphous lactose monohydrate (LM) SDs showed better bioavailability of APIs (~356.27.8% and 154.01% for the relative bioavailability of LBQ 657 and valsartan, respectively). Co-amorphous inert carrier SDs possessed an excellent compressibility for the production of a direct compression pharmaceutical product. In conclusion, these brand-new co-amorphous SDs could reduce the number of unit processes to produce a final pharmaceutical product for downstream manufacturability.


Author(s):  
Ammaru Ismaila ◽  
Xueli Chen ◽  
Xin Gao ◽  
Xiaolei Fan

Abstract Thermodynamic chemical equilibrium analysis of steam reforming of glycerol (SRG) for selective hydrogen production was performed based on the Gibbs free energy minimisation method. The ideal SRG reaction (C3H8O3+ 3H2O → 3CO2+7H2) and a comprehensive set of side reactions during SRG are considered for the formation of a wide range of products. Specifically, this work focused on the analysis of formation of CO2, CO and CH4 in the gas phase and determination of the carbon free region in SRG under the conditions at atmospheric pressure, 600 K–1100 K and 1.013 × 105–1.013 × 106 Pa with the steam-to-glycerol feed ratios (SGFR) of 1:5–10. The reaction conditions which favoured SRG for H2 production with minimum coke formation were identifies as: atmospheric pressure, temperatures of 900 K–1050 K and SGFR of 10:1. The influence of using the inert carrier gas (i.e., N2) in SRG was studied as well at atmospheric pressure. Although the presence of N2 in the stream decreased the partial pressure of reactants, it was beneficial to improve the equilibrium yield of H2. Under both conditions of SRG (with/without inert gas), the CH4 production is minimised, and carbon formation was thermodynamically unfavoured at steam rich conditions of SGFR > 5:1.


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