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Results for “LACTIC ACID”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 199 records · Page 11
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Modulation of the uptake of critical nutrients by breast cancer cells by lactate: Impact on cell survival, proliferation and migration

This work aimed to characterize the uptake of folate and glucose by breast cancer cells and to study the effect of lactate upon the transport of these nutrients and upon cell viability, proliferation and migration capacity. Data obtained showed that: a) MCF7 cells uptake {sup 3}H-folic acid ({sup 3}H-FA) at physiological but not at acidic pH; b) T47D cells accumulate {sup 3}H-FA and {sup 14}C-5-methyltetrahydrofolate ({sup 14}C-5-MTHF) more efficiently at acidic than at physiological pH; c) {sup 3}H-deoxyglucose ({sup 3}H-DG) uptake by T47D cells is sodium-independent, inhibited by cytochalasin B (CYT B) and stimulated by insulin. Regarding the effect of lactate, in T47D cells, acute (26 min) and chronic (24 h) exposure to lactic acid (LA) stimulated {sup 3}H-FA uptake. Acute exposure to LA also stimulated {sup 3}H-DG uptake and chronic exposure to LA significantly stimulated T47D cell migratory capacity. In conclusion, the transport of folates is strikingly different in two phenotypically similar breast cancer cell lines: MCF7 and T47D cells. Additionally, lactate seems to act as a signaling molecule which increases the uptake of nutrients and promotes the migration capacity of T47D cells. - Highlights: • Transport of folates is strikingly different in MCF7 and T47D cells. • Lactate increases the uptake of folate and glucose by T47D cells. • Lactate promotes T47D cell migratory capacity.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2019

Preparation of Chitooligosaccharide by Hydrogen Peroxide Degradation of Chitosan and Its Effect on Soybean Seed Germination

Chitooligosaccharides (COS) were prepared by hydrogen peroxide (1%) degradation of chitosan solution (3%) in dilute lactic acid at ambient temperature. The molecular weights of degraded chitosan were measured by gel permeation chromatography, and the chemical structure of resultant COS were characterized by Fourier transform infrared spectra. The decrease of chitosan Mw followed the first-order kinetics with the rate constant of 5.71 × 10{sup −7} mol/g/h. As a result, the COS with Mw of 4500 g/mol was obtained at 360 h of the reaction time and its chemical structure almost remained the same as initial chitosan. Germination ability of soybean seeds pre-soaking in COS (4500 g/mol) solution with different concentrations, particularly 0 (control), 50, 100 and 200 mg/L was investigated. Results indicated that germination rate increased significantly for all soybean seeds treated with COS compared to the control. Thus, COS prepared by this method can be potentially applied to large-scale production with reasonably low cost and used as an effective biostimulant for sustainable agriculture.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2012

Lipophilic ternary complexes in liquid-liquid extraction of trivalent lanthanides

The formation of ternary complexes between lanthanide ions [Nd(III) or Eu(III)], octyl(phenyl)-N,N-diisobutyl-carbamoylmethylphosphine oxide (CMPO), and bis-(2-ethylhexyl)phosphoric acid (HDEHP) was probed by liquid-liquid extraction and spectroscopic techniques. Equilibrium modeling of data for the extraction of Nd(III) or Eu(III) from lactic acid media into n-dodecane solutions of CMPO and HDEHP indicates the predominant extracted species are of the type [Ln(AHA){sub 2}(A)] and [Ln(CMPO)(AHA){sub 2}(A)], where Ln = Nd or Eu and A represents the DEHP{sup -} anion. FTIR (for both Eu and Nd) and visible spectrophotometry (in the case of Nd) indicate the formation of the [Ln(CMPO)(A){sup 3}] complexes when CMPO is added to n-dodecane solutions of the LnA{sub 3} compounds. Both techniques indicate a stronger propensity of CMPO to complex Nd(III) versus Eu(III).

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2013

Improved biogas production from rice straw by co-digestion with kitchen waste and pig manure

Highlights: • Biogas production was enhanced by co-digestion of rice straw with other materials. • The optimal ratio of kitchen waste, pig manure and rice straw is 0.4:1.6:1. • The maximum biogas yield of 674.4 L/kg VS was obtained. • VFA inhibition occurred when kitchen waste content was more than 26%. • The dominant VFA were propionate and acetate in successful reactors. - Abstract: In order to investigate the effect of feedstock ratios in biogas production, anaerobic co-digestions of rice straw with kitchen waste and pig manure were carried out. A series of single-stage batch mesophilic (37 ± 1 °C) anaerobic digestions were performed at a substrate concentration of 54 g/L based on volatile solids (VS). The results showed that the optimal ratio of kitchen waste, pig manure, and rice straw was 0.4:1.6:1, for which the C/N ratio was 21.7. The methane content was 45.9–70.0% and rate of VS reduction was 55.8%. The biogas yield of 674.4 L/kg VS was higher than that of the digestion of rice straw or pig manure alone by 71.67% and 10.41%, respectively. Inhibition of biogas production by volatile fatty acids (VFA) occurred when the addition of kitchen waste was greater than 26%. The VFA analysis showed that, in the reactors that successfully produced biogas, the dominant intermediate metabolites were propionate and acetate, while they were lactic acid, acetate, and propionate in the others.

09 BIOMASS FUELS↗
DOE OSTI2018

Degradation of Polylactic Acid by Irradiation

Polylactic acid (PLA) waste has various treatment methods, such as natural decomposition, composting, incineration, and hydrolysis. Degradation of PLA waste by gamma ray and pulsed light irradiation is an efficient, safe and innovative method that also protects the environment. The focus of this study was on the development of an alternative, green technology for solving the PLA waste disposal problem of PLA, rather than using incineration or the landfill method. We used a novel approach to identify the thermal decomposition and heat properties of crystalline poly lactic acid, non-crystalline polylactic acid, and blend polylactic acid. The approach involved the degradation of the materials with gamma ray and pulsed light irradiation followed by thermogravimetric analysis (TGA). We also developed a novel approach to the heat effect, including heat reactivity properties by TGA tests and thermal mass loss simulation for proper application, processing, and waste treatment conditions. The data from this study can be used to improve the design of operation and waste treatment protocols for PLA, which will benefit the environment.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Microbiological, Physicochemical, and Immunological Analysis of a Commercial Cashew Nut-Based Yogurt

Nut-based milks and yogurts are gaining popularity, but may not offer the same benefits as dairy yogurts to consumers. Cashew nuts often cause severe allergic reactions, and cashew nut allergens are stable to several types of processing. To compare its characteristics to dairy yogurt and characterize the effects of fermentation on the Ana o 1–3 cashew nut allergens, a commercial yogurt made from cashew nuts (Cashewgurt) was evaluated for microbiological, physiochemical, and immunological properties. Average counts for lactobacilli and Streptococcus thermophilus were greater than 10 million colony forming units per milliliter, indicating the capacity to provide a health benefit. Cashewgurt pH and viscosity values were comparable to cow milk yogurts, and it was off white in color. SDS-PAGE analysis indicated a clear reduction in Ana o 1 and 2, and immuno-assay with polyclonal anti-cashew IgG antibody and cashew-allergic IgE indicated an overall reduction in allergen content. In contrast, SDS-PAGE, mass spectrometry, immunoblot, and ELISA all revealed that Ana o 3 was relatively unaffected by the fermentation process. In conclusion, Ana o 1 and Ana o 2 are sensitive to degradation, while Ana o 3 survives lactic acid bacterial fermentation during yogurt production. The analysis presented here indicates that cashew nut yogurt is not suitable for those with cashew nut allergy.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2018

Fermentation of dihydroxyacetone by engineered Escherichia coli and Klebsiella variicola to products

Methane can be converted to triose dihydroxyacetone (DHA) by chemical processes with formaldehyde as an intermediate. Carbon dioxide, a by-product of various industries including ethanol/butanol biorefineries, can also be converted to formaldehyde and then to DHA. DHA, upon entry into a cell and phosphorylation to DHA-3-phosphate, enters the glycolytic pathway and can be fermented to any one of several products. However, DHA is inhibitory to microbes due to its chemical interaction with cellular components. Fermentation of DHA to d -lactate by Escherichia coli strain TG113 was inefficient, and growth was inhibited by 30 g⋅L −1 DHA. An ATP-dependent DHA kinase from Klebsiella oxytoca (pDC117d) permitted growth of strain TG113 in a medium with 30 g⋅L −1 DHA, and in a fed-batch fermentation the d -lactate titer of TG113(pDC117d) was 580 ± 21 mM at a yield of 0.92 g⋅g −1 DHA fermented. Klebsiella variicola strain LW225, with a higher glucose flux than E. coli , produced 811 ± 26 mM d -lactic acid at an average volumetric productivity of 2.0 g −1 ⋅L −1 ⋅h −1 . Fermentation of DHA required a balance between transport of the triose and utilization by the microorganism. Using other engineered E. coli strains, we also fermented DHA to succinic acid and ethanol, demonstrating the potential of converting CH 4 and CO 2 to value-added chemicals and fuels by a combination of chemical/biological processes.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2019

Life Cycle Impact Assessment of Polylactic Acid (PLA) Produced from Sugarcane in Thailand

In this study we provide up-to-date cradle-to-gate information on the environmental footprint of polylactic acid (PLA) produced in Thailand at commercial scale, covering emerging topics such as water footprint and direct land use change. The enormous potential to further reduce the environmental impacts of PLA through improvements in feedstock production as well as in the PLA manufacturing process is also demonstrated. Life cycle assessment (LCA) is performed according to the ISO 14040/44 standard methodology. The 16 environmental impact categories from ILCD 2011 Midpoint + were considered for the hotspot analysis. As primary data actual industrial data were used for the sugar production, lactic acid production (Corbion) and PLA production (Total Corbion PLA), including various recently developed process insights. The agricultural feedstock production and the manufacturing process of PLA from sugar contributed most to the LCA impacts of PLA production. The sugarcane crop production particularly affected the environmental impact categories analyzed, including global warming potential (GWP), water, eutrophication, acidification, particulate matter and, inevitably, land use. However, when combined with the results of a sustainability risk assessment study, it becomes clear that land use and water-related impacts represent a low risk for the feedstock-sourcing area. The environmental impact categories of PLA manufacturing are mostly linked to energy and chemicals usage. Improvements in the environmental performance of PLA can be achieved through improvements in the sugarcane farming practices, higher efficiency bagasse boilers at the sugarmill, reduced usage of auxiliary chemicals and increased usage of renewable energy in the conversion process of sugar to PLA. From a cradle-to-gate perspective, considering the uptake of carbon dioxide in the PLA molecule, the GWP is 501 kg CO{sub 2} eq/ton PLA.

09 BIOMASS FUELS↗
DOE OSTI2021

Ad-apoptin inhibits glycolysis, migration and invasion in lung cancer cells targeting AMPK/mTOR signaling pathway

Ad-apoptin is a recombinant oncolytic adenovirus constructed by our laboratory that can express apoptin. It can selectively kill tumor cells without damaging normal cells. This study investigated the effects of Ad-apoptin on glycolysis, migration and invasion of non-small cell lung cancer. Cell viability and apoptosis were detected by CCK-8 and flow cytometry, respectively. Glycolysis was investigated by glucose consumption, lactic acid production and glycolytic key enzyme protein levels. Migration and invasion were evaluated via wound healing, transwell assays and epithelial-mesenchymal transition (EMT) protein levels. The interaction between apoptin and AMPK was detected by Co-IP. A nude mice tumor model was established to investigate the anti-cancer role of Ad-apoptin in vivo. The results showed that Ad-apoptin inhibits cell viability and induces apoptosis of A549 and NCI–H23 cells. Ad-apoptin can reduce the glucose uptake and lactic production in lung cancer cells, and reduce the expression of related glycolysis-limiting enzymes. At the same time, Ad-apoptin inhibited the migration and invasion of lung cancer. Immunoprecipitation showed that apoptin and AMPK could interact directly. Moreover, knockdown of AMPK significantly attenuated the inhibitory effect of Ad-apoptin on glycolysis, migration and invasion of A549 and NCI–H23 cells. Ad-apoptin can inhibit the growth of tumors in nude mice. Compared with the control group, Ad-apoptin had a significant inhibitory effect on AMPK knockdown tumors. The immunohistochemical results of tumor tissues were consistent with those in vitro. Collectively, Ad-apoptin targets AMPK and inhibits glycolysis, migration and invasion of lung cancer cells through the AMPK/mTOR signaling pathway. This suggests that Ad-apoptin may have therapeutic potential for lung cancer by targeting AMPK activation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

PLA recycling by hydrolysis at high temperature

In this work the process of PLA hydrolysis at high temperature was studied, in order to evaluate the possibility of chemical recycling of this polymer bio-based. In particular, the possibility to obtain the monomer of lactic acid from PLA degradation was investigated. The results of some preliminary tests, performed in a laboratory batch reactor at high temperature, are presented: the experimental results show that the complete degradation of PLA can be obtained in relatively low reaction times.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Microalgae Conversion to Biofuels and Biochemical via Sequential Hydrothermal Liquefaction (SEQHTL) and Bioprocessing: 2020 State of Technology

A preliminary techno-economic analysis (TEA) was developed for the fiscal year 2020 state of technology (SOT) assessment to evaluate the benefits and risks for a large-scale microalga hydrothermal liquefaction (HTL) system based on most recent testing results. The focus of the study is directed toward the conversion system, which consists of five processes: two-stage sequential HTL (SEQHTL), biocrude upgrading to final fuels, bioprocessing for co-product generation, hydrogen generation, and steam cycle. In this system, algae biomass with corn stover supplement during the lower algae productivity seasons (winter, fall, and spring) to match the maximum algae seasonal production rate in summer is employed to maintain a constant plant capacity in all the seasons. Algae only (summer season) or algae/corn stover blended feedstock (other seasons) are sent to a two-stage SEQHTL process. In stage I, the carbohydrates in the feedstock are extracted and separated from the residual solid. The residual solid from stage I is further converted to biocrude in the SEQHTL stage II step. The biocrude is upgraded to final fuel products in an upgrading process. The extract stream from HTL stage I is sent to the bioprocessing section for co-product generation via fermentation of carbohydrate. Lactic acid (LA) is assumed to be the co-product based on current bioprocessing testing results.

09 BIOMASS FUELS↗
DOE OSTI2017

Improving the circular economy via hydrothermal processing of high-density waste plastics

Highlights: • High-density plastics are susceptible to supercritical hydrothermal processing. • Plastics convert into their monomers and value-added chemical compounds. • Nearly 100% conversion of PC into synthetic crude oil. • Degradation of PET and PBT yields high quantity of their monomer terephtalic acid. • Hydrothermal processing is a prospective technology for unrecyclable waste plastics. - Abstract: Rising environmental concerns on climate changes are causing an increasing attention on circular economies. The plastic economy, in particular, is in focus due to the accelerating consumption of plastics, mainly derived from virgin feedstock, combined with the lack of plastic recycling strategies. This work presents a novel outlook on the potential of using supercritical hydrothermal processing of waste plastic fractions for tertiary recycling. The study investigates hydrothermal processing of nine different, high-density types of plastics into original resin monomers and other value-added chemical compounds. The outlook presents conversion yields, carbon balances, and chemical details on the products obtained. It is found that all the investigated resins are prone to hydrothermal treatment, and that high yields of monomers and high value compounds (up to nearly 100%), suitable for chemicals and fuels applications, can be obtained. For instance, for polycarbonate, styrene-butadiene, poly(lactic acid), poly(ethylene terephthalate), and poly(butylene terephthalate), original monomeric compounds can be reclaimed for manufacturing new resins. The promising results presented demonstrate that hydrothermal processing of high-density plastics is a prospective technology for increasing the circularity of the plastic economy.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2021

PGC1α regulates mitochondrial oxidative phosphorylation involved in cisplatin resistance in ovarian cancer cells via nucleo-mitochondrial transcriptional feedback

Mitochondria play an important role in effective cell energy production and cell survival under stress conditions, such as treatment with chemotherapeutic drugs. Mitochondrial biogenesis is increased in ovarian cancer tissues, which is accompanied by alteration of mitochondrial energy metabolism, structure, and dynamics. These factors are involved in tumorigenesis and apoptosis resistance, highlighting the role of mitochondria in resisting cisplatin toxicity. Cisplatin-resistant ovarian cancer cells are dependent on mitochondrial OXPHOS for energy supply, and intracellular PGC1α-mediated mitochondrial biogenesis levels are increased in this cell line, indicating the important role of mitochondrial oxidative phosphorylation in cisplatin resistance. As PGC1α is a key molecule for integrating and coordinating nuclear DNA and mitochondrial DNA transcriptional machinery, an investigation into the regulatory mechanism PGC1α in mitochondrial energy metabolism via transcription may provide new clues for solving chemotherapy resistance. In the present study, it was demonstrated that inhibiting the expression of PGC1α decreased nuclear and mitochondrial DNA transcription factor expression, leading to increased lactic acid production and decreased cellular oxygen consumption and mitochondrial oxidative phosphorylation. Furthermore, mitochondrial stress-induced ROS production, as a feedback signal from mitochondria to the cell nucleus, increased PGC1α expression in SKOV3/DDP cells, which was involved in mitochondrial oxidative phosphorylation regulation. Collectively, the present study provides evidence that PGC1α-mediated nuclear and mitochondrial transcription feedback regulates energy metabolism and is involved in ovarian cancer cells escaping apoptosis during cisplatin treatment.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Fabrication of micro-hollow fiber by electrospinning process in near-critical carbon dioxide

Electrospinning is a simple technique that has gained much attention because of its capability and feasibility in the fabrication of large quantities of fibers from polymer with diameters ranging in nano-microscale. These fibers provided high surface area to volume ratios, and it was of considerable interest for many applications, such as nanoparticle carriers in controlled release, scaffolds in tissue engineering, wound dressings, military wear with chemical and biological toxin-resistance, nanofibrous membranes or filters, and electronic sensors. Recently there has been a great deal of progress in the potential applications of hollow fibers in microfluids, photonics, and energy storage. In this work, electrospinning was conducted under high-pressure carbon dioxide (CO{sub 2}) to reduce the viscosity of polymer solution. The experiments were conducted at 313 K and ∼8.0 MPa. Polymer solution containing 5 wt% polymers which prepared in dichloromethane (DCM) with polyvinylpyrrolidone (PVP) to poly-L-lactic acid (PLLA) ratio 80:20 was used as a feed solution. The applied voltage was 15 kV and the distance of nozzle and collector was 8 cm. The morphology and structure of the fibers produced were observed using scanning electron microscopy (SEM). Under pressurized CO{sub 2}, PVP electrospun was produced without bead formation with diameter ranges of 608.50 - 7943.19 nm. These behaviors hold the potential to considerably improve devolatilization electrospinning processes.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Exploiting chitosan to improve the interface of nanocellulose reinforced polymer composites

Cellulose nanofibrils (CNFs) have been widely used as a nanofiller for polymer composite reinforcement due to their excellent mechanical properties. However, CNF is produced in water and needs to be dried prior to use in composite materials. The presence of hydroxyl groups on the surface of CNF creates strong hydrogen bonding that makes it difficult and costly to dry. Additionally, the hydrophilicity at the fiber surface results in agglomeration of CNFs within many polymer matrices. In this study, chitosan (CS) was co-precipitated with CNF to produce a dual-bonding filler for use in poly (lactic acid) (PLA) composites. CS promotes improved interfacial interaction within the polymer matrix by forming strong hydrogen bonds with the CNF and potential covalent bonds with the PLA. Finally, the results confirmed that the addition of a small amount of CS significantly improved the mechanical properties compared to PLA + CNF composites and neat PLA. The detailed study of the PLA + CNF/CS composites reveals the synergetic effect of the hydrogen and covalent bonding mechanism for PLA reinforcement.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2019

Abiotic Hydrolysis and Compostability of Blends Based on Cassava Starch and Biodegradable Polymers

When associated with polymer blends, starch may improve the biodegradability and compostability of other materials. The objectives of this work were to evaluate the abiotic hydrolysis and the composting process of films obtained from polymer blends between thermoplastic starch (TPS) and three other biodegradable polymers: poly[(butylene adipate)- co -(terephthalate)] (PBAT), poly(lactic acid) (PLA) and polyvinyl alcohol (PVA). PVA/TPS stood out as the most homogeneous blend and the one that showed the highest weight loss, with 46.21% of its initial weight remaining after abiotic hydrolysis tests. On the other hand, PBAT/TPS and PLA/TPS underwent more drastic and rapid degradation during composting in contrast to PVA/TPS. They became very fragmented after 21 days of composting, while the PVA/TPS was visually modified but remained unbroken until day 70. No blend sample exerted negative effects on the quality of the compost.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Atomic and molecular layer deposition for surface modification

Atomic and molecular layer deposition (ALD and MLD, respectively) techniques are based on repeated cycles of gas–solid surface reactions. A partial monolayer of atoms or molecules is deposited to the surface during a single deposition cycle, enabling tailored film composition in principle down to molecular resolution on ideal surfaces. Typically ALD/MLD has been used for applications where uniform and pinhole free thin film is a necessity even on 3D surfaces. However, thin – even non-uniform – atomic and molecular deposited layers can also be used to tailor the surface characteristics of different non-ideal substrates. For example, print quality of inkjet printing on polymer films and penetration of water into porous nonwovens can be adjusted with low-temperature deposited metal oxide. In addition, adhesion of extrusion coated biopolymer to inorganic oxides can be improved with a hybrid layer based on lactic acid. - Graphical abstract: Print quality of a polylactide film surface modified with atomic layer deposition prior to inkjet printing (360 dpi) with an aqueous ink. Number of printed dots illustrated as a function of 0, 5, 15 and 25 deposition cycles of trimethylaluminum and water. - Highlights: • ALD/MLD can be used to adjust surface characteristics of films and fiber materials. • Hydrophobicity after few deposition cycles of Al{sub 2}O{sub 3} due to e.g. complex formation. • Same effect on cellulosic fabrics observed with low temperature deposited TiO{sub 2}. • Different film growth and oxidation potential with different precursors. • Hybrid layer on inorganic layer can be used to improve adhesion of polymer melt.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Formulation of Green Particulate Composites from PLA and PBS Matrix and Wastes Deriving from the Coffee Production

Particulate composites based on poly(lactic acid) and poly(butylene succinate) biopolymers have been formulated. Silver skin, the by-product derived from the roasting of coffee beans, has been used as a filler up to a 30 wt% of loading. The microstructure, crystallinity, thermal stability, mechanical properties and water absorption of the derived composites have been investigated. Data so far collected underline that a trade-off of the mechanical properties can be obtained by adding the filler, while the overall amount of crystallinity remains constant. Up to the highest filler content, moisture uptake follows a Fichian behaviour while the value of the contact angle is slightly increased by modification. Thus, silver skin, which actually is used for fuel or soil fertilization, finds here a different environmentally friendly valorization into the field of biocomposites.

36 MATERIALS SCIENCE↗