Synthesis of high-performance Li2FeSiO4/C composite powder by spray-freezing/freeze-drying a solution with two carbon sources

The safety and efficacy of a drug is based on its metabolism or metabolite formed. The metabolism of drugs can be studied by different in vitro models, among which microbial model became popular. In the present study, eight microbes were screened for their ability to metabolize phenobarbital in a manner comparable to humans with a model to develop alternative systems to study human drug metabolism. Among the different microbes screened, a filamentous fungi Rhizopus stolonifer metabolized phenobarbital to its metabolite which is used for further pharmacological and toxicological studies. The transformation of phenobarbital was identified by high- performance liquid chromatography (HPLC). Interestingly, Rhizopus stolonifer sample showed an extra metabolite peak at 3.11min. compared to its controls. The influence of different carbon sources in media used for growth of fungus, on metabolite production was studied, to find its effect in production of metabolite as the carbon source may influence the growth of the cell.

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Defect-induced B4C electrodes for high energy density supercapacitor devices

Scientific Reports ◽

10.1038/s41598-021-90878-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Özge Balcı ◽

Merve Buldu ◽

Ameen Uddin Ammar ◽

Kamil Kiraz ◽

Mehmet Somer ◽

...

Keyword(s):

Active Carbon ◽

High Performance ◽

Carbon Sources ◽

High Energy ◽

High Energy Density ◽

Synthesis Conditions ◽

High Energy Ball Mill ◽

Energy Ball ◽

G Ratio ◽

Energy And Power Density

AbstractBoron carbide powders were synthesized by mechanically activated annealing process using anhydrous boron oxide (B2O3) and varying carbon (C) sources such as graphite and activated carbon: The precursors were mechanically activated for different times in a high energy ball mill and reacted in an induction furnace. According to the Raman analyses of the carbon sources, the I(D)/I(G) ratio increased from ~ 0.25 to ~ 0.99, as the carbon material changed from graphite to active carbon, indicating the highly defected and disordered structure of active carbon. Complementary advanced EPR analysis of defect centers in B4C revealed that the intrinsic defects play a major role in the electrochemical performance of the supercapacitor device once they have an electrode component made of bare B4C. Depending on the starting material and synthesis conditions the conductivity, energy, and power density, as well as capacity, can be controlled hence high-performance supercapacitor devices can be produced.

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Elucidation of the Crystal Growth Characteristics of SnO2 Nanoaggregates Formed by Sequential Low-Temperature Sol-Gel Reaction and Freeze Drying

Nanomaterials ◽

10.3390/nano11071738 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1738

Author(s):

Saeid Vafaei ◽

Alexander Wolosz ◽

Catlin Ethridge ◽

Udo Schnupf ◽

Nagisa Hattori ◽

...

Keyword(s):

Crystal Growth ◽

Low Temperature ◽

Photoelectron Spectroscopy ◽

High Performance ◽

Freeze Drying ◽

Sno2 Nanoparticles ◽

Sol Gel ◽

Functional Materials ◽

Cost Effective ◽

High Concentration

SnO2 nanoparticles are regarded as attractive, functional materials because of their versatile applications. SnO2 nanoaggregates with single-nanometer-scale lumpy surfaces provide opportunities to enhance hetero-material interfacial areas, leading to the performance improvement of materials and devices. For the first time, we demonstrate that SnO2 nanoaggregates with oxygen vacancies can be produced by a simple, low-temperature sol-gel approach combined with freeze-drying. We characterize the initiation of the low-temperature crystal growth of the obtained SnO2 nanoaggregates using high-resolution transmission electron microscopy (HRTEM). The results indicate that Sn (II) hydroxide precursors are converted into submicrometer-scale nanoaggregates consisting of uniform SnO2 spherical nanocrystals (2~5 nm in size). As the sol-gel reaction time increases, further crystallization is observed through the neighboring particles in a confined part of the aggregates, while the specific surface areas of the SnO2 samples increase concomitantly. In addition, X-ray photoelectron spectroscopy (XPS) measurements suggest that Sn (II) ions exist in the SnO2 samples when the reactions are stopped after a short time or when a relatively high concentration of Sn (II) is involved in the corresponding sol-gel reactions. Understanding this low-temperature growth of 3D SnO2 will provide new avenues for developing and producing high-performance, photofunctional nanomaterials via a cost-effective and scalable method.

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Optimization of sunflower head pectin extraction by ammonium oxalate and the effect of drying conditions on properties

Scientific Reports ◽

10.1038/s41598-021-89886-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Xuemei Ma ◽

Jiayi Yu ◽

Jing Jing ◽

Qian Zhao ◽

Liyong Ren ◽

...

Keyword(s):

High Performance ◽

Freeze Drying ◽

Antioxidant Activities ◽

Structural Characteristics ◽

Radical Scavenging ◽

Ammonium Oxalate ◽

Extraction Process ◽

Size Exclusion ◽

Pharmaceutical Industries

AbstractPectin is a kind of natural and complex carbohydrates which is extensively used in food, chemical, cosmetic, and pharmaceutical industries. Fresh sunflower (Helianthus annuus L.) heads were utilized as a novel source of pectin extracted by ammonium oxalate. The conditions of the extraction process were optimized implementing the response surface methodology. Under optimal extraction parameters (extraction time 1.34 h, liquid–solid ratio 15:1 mL/g, ammonium oxalate concentration 0.76% (w/v)), the maximum experimental yield was 7.36%. The effect of spray-drying and freeze-drying on the physiochemical properties, structural characteristics, and antioxidant activities was investigated by FT-IR spectroscopy, high performance size exclusion chromatography, and X-ray diffraction. The results showed freeze-drying lead to decrease in galacturonic acid (GalA) content (76.2%), molecular weight (Mw 316 kDa), and crystallinity. The antioxidant activities of pectin were investigated utilizing the in-vitro DPPH and ABTS radical-scavenging systems. This study provided a novel and efficient extraction method of sunflower pectin, and confirmed that different drying processes had an effect on the structure and properties of pectin.

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Trash into Treasure: stiff, thermally insulating and highly conductive carbon aerogels from leather wastes for high-performance electromagnetic interference shielding

Journal of Materials Chemistry C ◽

10.1039/d0tc05480a ◽

2021 ◽

Author(s):

Bin Yuan ◽

Shuangxin Lai ◽

Jianjun Li ◽

Li Li ◽

Shibing Bai

Keyword(s):

Electromagnetic Interference ◽

High Performance ◽

Freeze Drying ◽

Carbon Aerogels ◽

Urgent Problem ◽

Electromagnetic Interference Shielding ◽

Leather Wastes

Humans have used animal leather materials for thousands of years. Nowadays, the disposal of Cr-containing leather wastes (LWs) has become an urgent problem. Herein, by adopting simultaneously conventional freeze-drying and...

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Induction and Transcription Studies of the Dextransucrase Gene in Leuconostoc mesenteroides NRRL B-512F

Applied and Environmental Microbiology ◽

10.1128/aem.65.12.5504-5509.1999 ◽

1999 ◽

Vol 65 (12) ◽

pp. 5504-5509 ◽

Cited By ~ 31

Author(s):

M. Quirasco ◽

A. López-Munguía ◽

M. Remaud-Simeon ◽

P. Monsan ◽

A. Farrés

Keyword(s):

High Performance ◽

Leuconostoc Mesenteroides ◽

Carbon Sources ◽

Promoter Sequence ◽

Culture Conditions ◽

Start Codon ◽

Reaction Products ◽

Product Specificity ◽

First Time

ABSTRACT Dextransucrase production by Leuconostoc mesenteroidesNRRL B-512F in media containing carbon sources other than sucrose is reported for the first time. Dextransucrases were analyzed by gel electrophoresis and by an in situ activity assay. Their polymers and acceptor reaction products were also compared by 13C nuclear magnetic resonance and high-performance liquid chromatography techniques, respectively. From these analyses, it was found that, independently of the carbon source, L. mesenteroides NRRL B-512F produced dextransucrases of the same size and product specificity. The 5′ ends of dextransucrase mRNAs isolated from cells grown under different culture conditions were identical. Based on this evidence, we conclude that dextransucrases obtained from cells grown on the various carbon sources result from the transcription of the same gene. The control of expression occurs at this level. The low dextransucrase yields from cultures in d-glucose ord-fructose and the enhancement of dextransucrase gene transcription in the presence of sucrose suggest that an activating phenomenon may be involved in the expression mechanism. Dextransucrase mRNA has a size of approximately 4.8 kb, indicating that the gene is located in a monocistronic operon. The transcription start point was localized 34 bp upstream from the ATG start codon. The −10 and −35 sequences found, TATAAT and TTTACA, were highly homologous to the only glycosyltransferase promoter sequence reported for lactic acid bacteria.

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