Carbon Dioxide Carrier Research Articles

Using the pimeloyl-CoA synthetase adenylation fold to synthesize fatty acid thioesters.

Biotin is an essential vitamin in plants and mammals, functioning as the carbon dioxide carrier within central lipid metabolism. Bacterial pimeloyl-CoA synthetase (BioW) acts as a highly specific substrate-selection gate, ensuring the integrity of the carbon chain in biotin synthesis. BioW catalyzes the condensation of pimelic acid (C7 dicarboxylic acid) with CoASH in an ATP-dependent manner to form pimeloyl-CoA, the first dedicated biotin building block. Multiple structures of Bacillus subtilis BioW together capture all three substrates, as well as the intermediate pimeloyl-adenylate and product pyrophosphate (PPi), indicating that the enzyme uses an internal ruler to select the correct dicarboxylic acid substrate. Both the catalytic mechanism and the surprising stability of the adenylate intermediate were rationalized through site-directed mutagenesis. Building on this understanding, BioW was engineered to synthesize high-value heptanoyl (C7) and octanoyl (C8) monocarboxylic acid-CoA and C8 dicarboxylic-CoA products, highlighting the enzyme's synthetic potential.

Synthesis of N,N-dimethylformamide from carbon dioxide in aqueous biphasic solvent systems

This paper presents the homogeneous catalyzed hydrogenation of carbon dioxide to N,N-dimethylformamide (DMF) with an in-situ generated ruthenium catalyst based on RuCl3×H2O and the phosphine ligand 2,2′-bis(diphenylphosphinomethyl)-1,1′-biphenyl (BISBI). Investigations showed that the complex formation of an active species requires the presence of an amine. The catalyst was recycled by immobilization in a nonpolar alcoholic solvent while the formed product was extracted in-situ into the aqueous phase. The self-assembling reaction system showed stability for 10 recycling runs without a significant loss of activity resulting in an average yield of 31% DMF at 40bar and 140°C without the occurrence of any byproducts. Furthermore, a combination of the developed reaction system with ternary amines enables the application of wash amine solutions as carbon dioxide carrier.

Early diagnosis of sepsis using serum hemoglobin subunit Beta.

The development of new sepsis-specific biomarkers is mandatory to improve the detection and monitoring of the disease. Hemoglobin is the main oxygen and carbon dioxide carrier in cells of the erythroid lineage and is responsible for oxygen delivery to the respiring tissues of the body. Hemoglobin subunit beta (HBβ) is a component of a larger protein called hemoglobin. The aim of this study was to evaluate blood levels of HBβ in septic patients. A prospective study of 82 patients with sepsis was conducted. Furthermore, C57BL/6 mice were subjected to cecal ligation and puncture (CLP) surgery. Alternatively, human umbilical vein endothelial cells (HUVECs) or C57BL/6 mice were exposed to lipopolysaccharide (LPS, 100 ng/ml to HUVECs or 10 mg/kg to mice). The data showed that LPS induced upregulation of the synthesis and secretion of HBβ in LPS-treated HUVECs and in LPS-injected and CLP mice. In patients admitted to the intensive care unit with sepsis, circulating levels of HBβ were significantly high (sepsis, 64.93-114.76 ng/ml, n = 30; severe sepsis, 157.37-268.69 ng/ml, n = 22; septic shock, 309.98-427.03 ng/ml, n = 30) when compared to the levels of control donors (9.76-12.28 ng/ml, n = 21). Patients with septic shock had higher HBβ levels when compared to patients with severe sepsis. Furthermore, the HBβ levels in septic patients were higher than those in healthy volunteers. These results suggest that in septic patients, HBβ blood level is related to the severity of sepsis and may represent a novel endothelial cell dysfunction marker. Moreover, HBβ can be used as a biomarker to determine the severity of sepsis.

Lowering of elevated tissue PCO2 in a hemorrhagic shock rat model after reinfusion of a novel nanobiotechnological polyhemoglobin-superoxide dismutase-catalase-carbonic anhydrase that is an oxygen and a carbon dioxide carrier with enhanced antioxidant properties

Even though erythrocytes transport both oxygen and carbon dioxide, research on blood substitutes has concentrated on the transport of oxygen and its vasoactivity and oxidative effects. Recent study in a hemorrhagic shock animal model shows that the degree of tissue PCO2 elevation is directly related to mortality rates. We therefore prepared a novel nanobiotechnological carrier for both O2 and CO2 with enhanced antioxidant properties. This is based on the use of glutaraldehyde to crosslink stroma free hemoglobin (SFHb), superoxide dismutase (SOD), catalase (CAT) and carbonic anhydrase (CA) to form a soluble PolySFHb-SOD-CAT-CA. It was compared to blood and different resuscitation fluids on the ability to lower elevated tissue PCO2 in a 2/3 blood volume loss rat hemorrhagic shock model. Sixty minutes of sustained hemorrhagic shock at 30 mm Hg resulted in the increase of tissue PCO2 to 95 mm ± 3 mmHg from the control level of 55 mm Hg. Reinfusion of whole blood (Hb 15 g/dL with its RBC enzymes) lowered the tissue PCO2 to 72 ± 4.5 mmHg 60 minutes after reinfusion. PolySFHb-SOD-CAT-CA (SFHb 10 g/dL plus additional enzymes) was more effective than whole blood in lowering PCO2 lowering this to 66.2 ± 3.5 mmHg. Ringer's Lactated solution or polyhemoglobin lowered the elevated PCO2 only slightly to 87 ± 4.5 mmHg and 84.8 ± 1.5 mmHg, respectively. Moreover, ST-elevation for whole blood (Hb 15 g/dL) and PolySFHb-SOD-CAT-CA (Hb 10 g/dL) was respectively 12.8% ± 4% and 13.0% ± 2% of the control 60 minutes after reinfusion. Both are significantly better than those in the Ringer's lactated group and the PolyHb group. In conclusion, this novel approach for blood substitute design has resulted in a novel nanobiotechnological carrier for both O2 and CO2 with enhanced antioxidant properties.

Characterization of Adult α- and β-Globin Elevated by Hydrogen Peroxide in Cervical Cancer Cells That Play A Cytoprotective Role Against Oxidative Insults

ObjectivesHemoglobin (Hgb) is the main oxygen and carbon dioxide carrier in cells of erythroid lineage and is responsible for oxygen delivery to the respiring tissues of the body. However, Hgb is also expressed in nonerythroid cells. In the present study, the expression of Hgb in human uterine cervix carcinoma cells and its role in cervical cancer were investigated.MethodologyThe expression level of Hgb in cervical cancer tissues was assessed by quantitative reverse transcriptase-PCR (qRT-PCR). We applied multiple methods, such as RT-PCR, immunoblotting, and immunohistochemical analysis, to confirm Hgb expression in cervical cancer cells. The effects of ectopic expression of Hgb and Hgb mutants on oxidative stress and cell viability were investigated by cellular reactive oxygen species (ROS) analysis and lactate dehydrogenase (LDH) array, respectively. Both Annexin V staining assay by flow cytometry and caspase-3 activity assay were used, respectively, to evaluate cell apoptosis.ResultsqRT-PCR analysis showed that Hgb-α- (HBA1) and Hgb-β-globin (HBB) gene expression was significantly higher in cervical carcinoma than in normal cervical tissues, whereas the expression of hematopoietic transcription factors and erythrocyte specific marker genes was not increased. Immunostaining experiments confirmed the expression of Hgb in cancer cells of the uterine cervix. Hgb mRNA and protein were also detected in the human cervical carcinoma cell lines SiHa and CaSki, and Hgb expression was up-regulated by hydrogen peroxide-induced oxidative stress. Importantly, ectopic expression of wild type HBA1/HBB or HBA1, rather than mutants HBA1H88R/HBBH93R unable to bind hemo, suppressed oxidative stress and improved cell viability.ConclusionsThe present findings show for the first time that Hgb is expressed in cervical carcinoma cells and may act as an antioxidant, attenuating oxidative stress-induced damage in cervical cancer cells. These data provide a significant impact not only in globin biology but also in understanding of cervical cancer pathogenesis associated with oxidative stress.

Evaluation of an alcohol-based power sanitizing system for decontamination of hospital rooms of patients with methicillin-resistant Staphylococcus aureus carriage

A power sanitizing system that delivers a sanitizing mist of alcohol, rendered nonflammable by a carbon dioxide carrier, and a low concentration of quaternary ammonium compound, was easy to use, provided thorough coverage of surfaces, and significantly reduced vancomycin-resistant Enterococcus and methicillin-resistant Staphylococcus aureus contamination on commonly touched hospital surfaces. However, it was not as consistently effective for elimination of pathogens as 10% bleach solution.

Physicochemical properties of antifungal drug–cyclodextrin complexes prepared by supercritical carbon dioxide and by conventional techniques

Antifungal drugs are the most common systemic drugs used for the treatment of oropharyngeal candidiasis, which is the first symptom of HIV infection. However, the efficacy and bioavailability of these drugs have been limited by their poor aqueous solubility and dissolution rate. Therefore, the aim of this study was to investigate the effect of different preparation methods (i.e. kneading, coevaporation, sealed-heating, and a solid inclusion technique using supercritical carbon dioxide carrier (SC CO 2-inclusion)) for obtaining solid inclusion complexes between β-cyclodextrin and three antifungal drugs (itraconazole, econazole, and fluconazole). The physicochemical properties of the different products were characterized by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffractometry (PXRD). For the complexes prepared by the SC CO 2-inclusion method, the effects of temperature and pressure have also been investigated. Results suggested the possibility of complex formation between β-cyclodextrin and the three antifungal agents, and indicated that inclusion formation was influenced by the preparation technique. SC CO 2-inclusion method proved to be an effective technique for preparing solid-state inclusion complexes between β-cyclodextrin and antifungal drugs, avoiding the use of organic solvents. Moreover, temperature of the SC CO 2 played a major role in promoting drug–carrier interactions, whereas pressure had limited effects.

Cosorption effect in gas chromatography: flow fluctuations caused by adsorbing carrier gases

Adsorbing carrier gases have a number of advantages in analytical and preparative gas chromatography, such as clearer detector signals and higher column efficiencies. This work shows that adsorbing carrier gases also may be useful because they cause the mobile phase flow rate to become unsteady after injecting a small amount of sample. This work shows that a 100 microL sample of helium can liberate enough carbon dioxide carrier gas from a zeolite 5A packed column at 373 K, that the departure from the steady-state flow rate had an upper lobe area of 586 microL of carrier gas. This was confirmed by coupling a modified Langmuir kinetic model with the Ergun equation.

Metallic nanoparticle production utilizing a supercritical carbon dioxide flow process.

Metallic nanoparticles of palladium and silver ranging in size from 1 to 15 nm were produced entirely within carbon dioxide by spraying a carbon dioxide carrier solution containing CO2-soluble metal precursors into a CO2 receiving solution containing a reducing agent (NaBH(OAc)3 or H2) and fluorocarbon thiol stabilizing ligands. The process uses the benign solvent CO2 while also allowing for the production of nanoparticles with a limited number of chemical components. Particles were characterized by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS).

Capillary electrochromatography using columns packed with a supercritical fluid carrier

Columns for capillary electrochromatography may be prepared by packing reversed phase silica-based material using a supercritical fluid carbon dioxide carrier. Procedures for the in-situ manufacture of frits and UV detection windows, and the wetting of columns are described. The columns were employed in two commercial instruments (and a home-built system), and their properties investigated during the separation of standard mixtures of test compounds. The columns are highly efficient and durable, with reduced plate heights of 1.0–1.4. The repeatability of retention time, peak area and peak height was measured. The influence of applied voltage and column temperature and of electrokinetic injection parameters was explored, along with other practical considerations.

Lanthanoid complex as a novel carbon dioxide carrier for the carboxylation of active methylene compounds under mild conditions

A lanthanoid complex, formed by the addition of a lanthanoid alkoxide to an isocyanate, serves as a novel carbon dioxide carrier for the rapid carboxylation of active methylene compounds under mild conditions.

Supercritical carbon dioxide as a carrier for sample introduction in atomic absorption spectrometry

The use of a supercritical carbon dioxide carrier to transport organic solutions of metal complexes to a heated restrictor is demonstrated as a means of aerosol or vapour generation for sample introduction in flame atomic absorption spectrometry. Calibrations obtained using conventional pneumatic nebulisation of continuously aspirated solutions or using flow injection into a water carrier are compared with those obtained using the carbon dioxide carrier. Injection of solutions of copper pyrrolidinedithiocarbamate in 4-methyl pentan-2-one into a carbon dioxide carrier at 1000 p.s.i. was shown to 1.2 times more sensitive than injection of the same solutions into a water carrier with conventional nebulisation. The sensitivity of continuous nebulisation of the solutions, however, was not achieved. Dissolution of solid copper acetyl acetonate in supercritical carbon dioxide is demonstrated and subsequent vaporisation followed by atomisation in a heated quartz furnace is shown to occur.

A new process for indirect gas supply by means of perfluorinated polyethers

AbstractA new process has been developed for indirect gas supply for culturing shear sensitive cells by means of a perfluorinated hydrocarbon. Hostinert 216, a perfluorinated polyether, was used as oxygen and carbon dioxide carrier. Hydrodynamics and mass transfer, required for industrial implementation, were investigated in a drop column. Based on the knowledge, obtained with indirect gas supply, it has been possible to construct a waste‐gas free sterile pilot plant. Correlations derived from performed measurements permit design of and scale‐up to an industrial plant.

Increased facilitated transport related to microstructural changes in heat-treated ion-exchange membranes

Poly(perfluorosulfonic acid) ionomer films were subjected to a heat treatment, with a low volatility polar solvent, which swells the film. These swollen films were used as supports for liquid membranes using water as a solvent. The diffusive and facilitated transport of acid gases was measured and found to be greatly increased in these membranes versus untreated ones. Microstructural analysis of the films, using small angle X-ray scattering, indicates that there is an increase in the size of the ionic (hydrophilic) clusters. This increase in ionic cluster size correlates with the observed increase in permeability of the acid gases. The effective diffusion coefficient of the carbon dioxide carrier complex (determined from a model for facilitated transport) has increased by 1-2 orders of magnitude, while that of the carbon dioxide alone has increased only 4-fold over the same range of heat treatment conditions. The microstructural changes persist over extended periods of time, and therefore the heat treatment is possibly a practical means of increasing permeability for this polymer in commercial applications. In limited tests it has been previously confirmed that the selectivity of the treated membranes for carbon dioxide versus carbon monoxide remains high, with separation factors of 126 to 70.

Synthesis and structural characterization of the nitrosylcobalt complex Co(NO)2[PhP(OCH2CH2)2NH]Cl: a novel carbon dioxide carrier

Synthesis and structural characterization of the nitrosylcobalt complex Co(NO)2[PhP(OCH2CH2)2NH]Cl: a novel carbon dioxide carrier

The Function of Magnesium(II) N,N′-Dicyclohexylamidinide Complexes as a Carbon Dioxide Carrier

Abstract It is found that magnesium(II) N,N′-dicyclohexylamidinide complexes are useful reagents for the fixation of carbon dioxide and the transfer of the captured carbon dioxide moiety to active methylene compounds.

2-Morpholinoimidazolinomagnesium(II) complex as a novel carbon dioxide carrier

The magnesium complex (1) has been found to undergo fixation of carbon dioxide and the resulting 1-carboxylato-complex (2) transfers the carboxylato group to active methylene compounds (3) including acetophenone, benzylideneacetone, β-ionone, and S-benzyl thioacetate, under mild conditions.

Bifunctional activation of carbon dioxide. Synthesis and structure of a reversible carbon dioxide carrier

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBifunctional activation of carbon dioxide. Synthesis and structure of a reversible carbon dioxide carrierGiuseppe Fachinetti, Carlo Floriani, and Pier Francesco ZanazziCite this: J. Am. Chem. Soc. 1978, 100, 23, 7405–7407Publication Date (Print):November 1, 1978Publication History Published online1 May 2002Published inissue 1 November 1978https://doi.org/10.1021/ja00491a045RIGHTS & PERMISSIONSArticle Views934Altmetric-Citations136LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (407 KB) Get e-Alerts Get e-Alerts

Copper complex acting as a reversible carbon dioxide carrier

Copper complex acting as a reversible carbon dioxide carrier

ChemInform Abstract: SODIUM (N,N′‐ETHYLENEBIS(SALICYLIDENEIMINATO)COBALTATE(I)), A REVERSIBLE CARBON DIOXIDE CARRIER

Chemischer InformationsdienstVolume 5, Issue 47 Organoelement Compounds ChemInform Abstract: SODIUM (N,N′-ETHYLENEBIS(SALICYLIDENEIMINATO)COBALTATE(I)), A REVERSIBLE CARBON DIOXIDE CARRIER C. FLORIANI, C. FLORIANISearch for more papers by this authorG. FACHINETTI, G. FACHINETTISearch for more papers by this author C. FLORIANI, C. FLORIANISearch for more papers by this authorG. FACHINETTI, G. FACHINETTISearch for more papers by this author First published: November 26, 1974 https://doi.org/10.1002/chin.197447416AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume5, Issue47November 26, 1974 RelatedInformation