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1.
Glob Chall ; 7(6): 2300004, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37287598

ABSTRACT

Climate change is becoming increasingly more pronounced every day while the amount of greenhouse gases in the atmosphere continues to rise. CO2 reduction to valuable chemicals is an approach that has gathered substantial attention as a means to recycle these gases. Herein, some of the tandem catalysis approaches that can be used to achieve the transformation of CO2 to C-C coupled products are explored, focusing especially on tandem catalytic schemes where there is a big opportunity to improve performance by designing effective catalytic nanoreactors. Recent reviews have highlighted the technical challenges and opportunities for advancing tandem catalysis, especially highlighting the need for elucidating structure-activity relationships and mechanisms of reaction through theoretical and in situ/operando characterization techniques. In this review, the focus is on nanoreactor synthesis strategies as a critical research direction, and discusses these in the context of two main tandem pathways (CO-mediated pathway and Methanol-mediated pathway) to C-C coupled products.

2.
ACS Catal ; 13(11): 7230-7242, 2023 Jun 02.
Article in English | MEDLINE | ID: mdl-37288092

ABSTRACT

Since climate change keeps escalating, it is imperative that the increasing CO2 emissions be combated. Over recent years, research efforts have been aiming for the design and optimization of materials for CO2 capture and conversion to enable a circular economy. The uncertainties in the energy sector and the variations in supply and demand place an additional burden on the commercialization and implementation of these carbon capture and utilization technologies. Therefore, the scientific community needs to think out of the box if it is to find solutions to mitigate the effects of climate change. Flexible chemical synthesis can pave the way for tackling market uncertainties. The materials for flexible chemical synthesis function under a dynamic operation, and thus, they need to be studied as such. Dual-function materials are an emerging group of dynamic catalytic materials that integrate the CO2 capture and conversion steps. Hence, they can be used to allow some flexibility in the production of chemicals as a response to the changing energy sector. This Perspective highlights the necessity of flexible chemical synthesis by focusing on understanding the catalytic characteristics under a dynamic operation and by discussing the requirements for the optimization of materials at the nanoscale.

3.
Ind Eng Chem Res ; 61(34): 12857-12865, 2022 Aug 31.
Article in English | MEDLINE | ID: mdl-36065445

ABSTRACT

The reverse water gas shift reaction (RWGS) has attracted much attention as a potential means to widespread utilization of CO2 through the production of synthesis gas. However, for commercial implementation of RWGS at the scales needed to replace fossil feedstocks with CO2, new catalysts must be developed using earth abundant materials, and these catalysts must suppress the competing methanation reaction completely while maintaining stable performance at elevated temperatures and high conversions producing large quantities of water. Herein we identify molybdenum phosphide (MoP) as a nonprecious metal catalyst that satisfies these requirements. Supported MoP catalysts completely suppress methanation while undergoing minimal deactivation, opening up possibilities for their use in CO2 utilization.

4.
Nanoscale ; 14(35): 12620-12637, 2022 Sep 15.
Article in English | MEDLINE | ID: mdl-35975753

ABSTRACT

The feasibility of a Dual Function Material (DFM) with a versatile catalyst offering switchable chemical synthesis from carbon dioxide (CO2) was demonstrated for the first time, showing evidence of the ability of these DFMs to passively capture CO2 directly from the air as well. These DFMs open up possibilities in flexible chemical production from dilute sources of CO2, through a combination of CO2 adsorption and subsequent chemical transformation (methanation, reverse water gas shift or dry reforming of methane). Combinations of Ni Ru bimetallic catalyst with Na2O, K2O or CaO adsorbent were supported on CeO2-Al2O3 to develop flexible DFMs. The designed multicomponent materials were shown to reversibly adsorb CO2 between the 350 and 650 °C temperature range and were easily regenerated by an inert gas purge stream. The components of the flexible DFMs showed a high degree of interaction with each other, which evidently enhanced their CO2 capture performance ranging from 0.14 to 0.49 mol kg-1. It was shown that captured CO2 could be converted into useful products through either CO2 methanation, reverse water-gas shift (RWGS) or dry reforming of methane (DRM), which provides flexibility in terms of co-reactant (hydrogen vs. methane) and end product (synthetic natural gas, syngas or CO) by adjusting reaction conditions. The best DFM was the one containing CaO, producing 104 µmol of CH4 per kgDFM in CO2 methanation, 58 µmol of CO per kgDFM in RWGS and 338 µmol of CO per kgDFM in DRM.

5.
Chem Soc Rev ; 50(4): 2337-2366, 2021 Mar 01.
Article in English | MEDLINE | ID: mdl-33393529

ABSTRACT

Fischer-Tropsch synthesis (FTS) is an essential approach to convert coal, biomass, and shale gas into fuels and chemicals, such as lower olefins, gasoline, diesel, and so on. In recent years, there has been increasing motivation to deploy FTS at commercial scales which has been boosting the discovery of high performance catalysts. In particular, the importance of support in modulating the activity of metals has been recognized and carbonaceous materials have attracted attention as supports for FTS. In this review, we summarised the substantial progress in the preparation of carbon-based catalysts for FTS by applying activated carbon (AC), carbon nanotubes (CNTs), carbon nanofibers (CNFs), carbon spheres (CSs), and metal-organic frameworks (MOFs) derived carbonaceous materials as supports. A general assessment of carbon-based catalysts for FTS, concerning the support and metal properties, activity and products selectivity, and their interactions is systematically discussed. Finally, current challenges and future trends in the development of carbon-based catalysts for commercial utilization in FTS are proposed.

6.
Reprod Biol Endocrinol ; 18(1): 67, 2020 Jul 09.
Article in English | MEDLINE | ID: mdl-32646462

ABSTRACT

BACKGROUND: Poor ovarian response remains one of the biggest challenges for reproductive endocrinologists. The introduction of corifollitropin alpha (CFA) offered an alternative option to other gonadotropins for its longer half-life, its more rapid achievement of the threshold and higher FSH levels. We compared two different protocols with CFA, a long agonist and a short antagonist, and a no-CFA protocol. METHODS: Patients enrolled fulfilled at least two of the followings: AFC < 5, AMH < 1,1 ng/ml, less than three oocytes in a previous cycle, age > 40 years. Ovarian stimulation with an antagonist protocol was performed either with 300 UI rFSH and 150 UI rLH or 300UI HMG. In the long agonist group, after pituitary suppression with triptorelin, CFA was given the 1-2th day of cycle and 300 UI rFSH and 150 UI rLH the 5th day. In the short antagonist group CFA was given the 1-2th day of cycle and 300 UI rFSH and 150 UI rLH the 5th day. The primary objective was the effect on the number of oocytes and MII oocytes. Secondary objective were pregnancy rates, ongoing pregnancies and ongoing pregnancies per intention to treat. RESULTS: The use of CFA resulted in a shorter lenght of stimulation and a lower number of suspended treatments. Both the CFA protocols were significantly different from the no-CFA group in the number of retrieved oocytes (p < 0,05), with a non-significant difference in favour of the long agonist protocol. Both CFA groups yielded higher pregnancy rates, especially the long protocol, due to the higher number of oocytes retrieved (p < 0,05), as implantation rates did not differ. The cumulative pregnancy rate was also different, due to the higher number of cryopreserved blastocysts (p < 0,02). CONCLUSIONS: The long agonist protocol with the addition of rFSH and rLH showed the best results in all the parameters. A short antagonist protocol with CFA was less effective, but not significantly, although provided better results compared to the no-CFA group. We suggest that a long agonist protocol with CFA and recombinant gonadotropins might be a valuable option for poor responders. TRIAL REGISTRATION: The study was approved by the local Ethics Committee (EudraCT2015-002817-31).


Subject(s)
Follicle Stimulating Hormone, Human/therapeutic use , Infertility, Female/drug therapy , Ovulation Induction/methods , Adult , Female , Fertilization in Vitro/methods , Humans , Infertility, Female/therapy , Oocyte Retrieval/methods , Ovarian Reserve/drug effects , Ovarian Reserve/physiology , Pregnancy , Pregnancy Rate , Treatment Outcome
7.
J Vis ; 18(12): 7, 2018 11 01.
Article in English | MEDLINE | ID: mdl-30452585

ABSTRACT

The contrast sensitivity function (CSF) is an informative measure of visual function, but current tools for assessing it are limited by the attentional, motor, and communicative abilities of the participant. Impairments in these abilities can prevent participants from engaging with tasks or following an experimenter's instructions. Here, we describe an efficient new tool for measuring contrast sensitivity, Curveball, and empirically validate it with a sample of healthy adults. The Curveball algorithm continuously infers stimulus visibility through smooth eye tracking instead of perceptual report, and rapidly lowers stimulus contrast in real time until a threshold is found. The procedure requires minimal instruction to administer and takes only five minutes to estimate a full CSF, which is comparable to the best existing methods available for healthy adults. Task repeatability was high: the coefficients of repeatability were 0.275 (in log10 units of RMS contrast) within the same session and 0.227 across different days. We also present evidence that the task is robust across illumination changes, well correlated with results from conventional psychophysical methods, and highly sensitive to improvements in visual acuity from refractive correction. Our findings indicate that Curveball is a promising means of accurately assessing contrast sensitivity in previously neglected populations.


Subject(s)
Contrast Sensitivity/physiology , Pursuit, Smooth/physiology , Vision Tests/instrumentation , Adult , Algorithms , Female , Humans , Male , Psychophysics , Visual Acuity/physiology , Young Adult
8.
Angew Chem Int Ed Engl ; 57(46): 15045-15050, 2018 Nov 12.
Article in English | MEDLINE | ID: mdl-30134041

ABSTRACT

Methanol is a major fuel and chemical feedstock currently produced from syngas, a CO/CO2 /H2 mixture. Herein we identify formate binding strength as a key parameter limiting the activity and stability of known catalysts for methanol synthesis in the presence of CO2 . We present a molybdenum phosphide catalyst for CO and CO2 reduction to methanol, which through a weaker interaction with formate, can improve the activity and stability of methanol synthesis catalysts in a wide range of CO/CO2 /H2 feeds.

9.
Front Mol Neurosci ; 7: 59, 2014.
Article in English | MEDLINE | ID: mdl-25018694

ABSTRACT

Pea3 subfamily of E-twenty six transcription factors consist of three major -exhibit branching morphogenesis, the function of Pea3 family in nervous system development and regeneration is only beginning to unfold. In this study, we provide evidence that Pea3 can directs neurite extension and axonal outgrowth in different model systems, and that Serine 90 is important for this function. We have also identified neurofilament-L and neurofilament-M as two putative novel targets for Pea3.

10.
Acta Clin Belg ; 64(5): 429-33, 2009.
Article in English | MEDLINE | ID: mdl-19999391

ABSTRACT

In the diagnosis of polycythaemia vera and essential thrombocythaemia, two molecular markers were described in the last decade: the overexpression of the PRV-1 gene and the V617F mutation in the JAK2 gene. In this study we assess their usefulness by comparing our test results with the available clinical data. We show that in the diagnosis of polycythaemia vera the JAK2 mutation screening is crucial, while testing for the PRV-1 overexpression is redundant. On the contrary, in the diagnosis of essential thrombocythaemia (ET), both JAK2 and PRV-1 show their usefulness.


Subject(s)
Isoantigens/metabolism , Janus Kinase 2/genetics , Membrane Glycoproteins/metabolism , Neutrophils/metabolism , Polycythemia Vera/diagnosis , Receptors, Cell Surface/metabolism , Thrombocythemia, Essential/diagnosis , Biomarkers/metabolism , GPI-Linked Proteins , Gene Expression Regulation/physiology , Mutation , Polycythemia Vera/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Sensitivity and Specificity , Thrombocythemia, Essential/genetics , Thrombocythemia, Essential/metabolism , World Health Organization
11.
Neuropharmacology ; 42(6): 782-91, 2002 May.
Article in English | MEDLINE | ID: mdl-12015204

ABSTRACT

Among the pharmacological actions of gamma-hydroxybutyric acid (GHB), some may involve GABA(A) receptor-mediated mechanisms. GHB, however, fails to directly interact with sites for agonists and modulators on the GABA(A) receptor complex. We hypothesized that, in vivo, GHB may interfere with GABA(A) receptor function by altering the brain concentrations of the neurosteroids 3 alpha-hydroxy-5 alpha-pregnan-20-one (allopregnanolone, AP) and 3 alpha,21-dihydroxy-5 alpha-pregnan-20-one (allotetrahydrodeoxycorticosterone, THDOC), positive allosteric modulators of GABA-gated chloride currents. In male Wistar rats, GHB dose-dependently (75-1000 mg/kg, i.p.) increased AP, THDOC and their precursors pregnenolone and progesterone in brain cortex and hippocampus. The increases of AP (4-5 fold) and THDOC (3-4 fold) elicited by 300 mg/kg GHB peaked between 30 and 90 min and abated by 180 min. The selective GABA(B) receptor antagonist SCH 50911 (50 mg/kg, i.p.) prevented the action of GHB, while the GABA(B) receptor agonist baclofen (5-10 mg/kg) mimicked it. NCS-382 (50 mg/kg, i.p.), the purported selective antagonist of the GHB receptor, failed to antagonize GHB, but at 300 mg/kg increased brain cortical neurosteroids to the same extent as 300 mg/kg GHB; coadministration of GHB and NCS-382, however, failed to yield an additive effect. These results strongly suggest that GHB, via a GABA(B) receptor-mediated mechanism, increases the brain concentrations of neurosteroids, whose properties as amplifiers of the GABA-gated chloride conductances may play a role in the GABA(A) receptor-mediated pharmacological actions of GHB.


Subject(s)
Desoxycorticosterone/biosynthesis , Hydroxybutyrates/pharmacology , Pregnanolone/biosynthesis , Receptors, GABA-B/physiology , Animals , Baclofen/pharmacology , Cerebral Cortex/drug effects , Cerebral Cortex/metabolism , Desoxycorticosterone/analogs & derivatives , Desoxycorticosterone/blood , Desoxycorticosterone/metabolism , Dose-Response Relationship, Drug , GABA-B Receptor Agonists , GABA-B Receptor Antagonists , Hippocampus/drug effects , Hippocampus/metabolism , Male , Pregnanolone/blood , Pregnanolone/metabolism , Rats , Rats, Wistar
12.
Eur J Pharmacol ; 430(2-3): 369-71, 2001 Nov 02.
Article in English | MEDLINE | ID: mdl-11711056

ABSTRACT

The cannabinoid CB(1) receptor antagonist, N-piperidino-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-3-pyrazole-carboxamide) (SR 141716); 0.3-3 mg/kg, i.p., twice daily for 10 days), prevented the acquisition of alcohol drinking behavior in rats genetically selected for alcohol preference (Sardinian alcohol-preferring (sP) rats), having the free choice between alcohol (10%, v/v) and water. The results suggest that activation of cannabinoid CB(1) receptors is essential for the acquisition of alcohol drinking behavior in animals with a genetically determined alcohol preference.


Subject(s)
Alcohol Drinking/physiopathology , Drinking Behavior/drug effects , Piperidines/pharmacology , Pyrazoles/pharmacology , Receptors, Drug/antagonists & inhibitors , Alcohol Drinking/genetics , Animals , Behavior, Animal/drug effects , Male , Rats , Receptors, Cannabinoid , Receptors, Drug/physiology , Rimonabant
13.
Eur J Pharmacol ; 428(3): 315-21, 2001 Oct 12.
Article in English | MEDLINE | ID: mdl-11689189

ABSTRACT

The present study was aimed at identifying the receptor systems involved in the mediation of the sedative/hypnotic effect of gamma-hydroxybutyric acid (GHB) in DBA mice. Administration of the putative antagonist of the GHB binding site, 6,7,8,9-tetrahydro-5-hydroxy-5H-benzocyclohept-6-ylideneacetic acid (NCS-382; 50-500 mg/kg, i.p.), significantly increased the duration of loss of righting reflex induced by GHB (1000 mg/kg, i.p.). In contrast, the GABA(B) receptor antagonists, (2S)(+)-5,5-dimethyl-2-morpholineacetic acid (SCH 50911; 25-100 mg/kg, i.p.) and (3-aminopropyl)(cyclohexylmethyl)phosphinic acid (CGP 46381; 12.5-150 mg/kg, i.p.), completely prevented the sedative/hypnotic effect of GHB. SCH 50911 (100 and 300 mg/kg, i.p.) was also capable to readily reverse the sedative/hypnotic effect of GHB (1000 mg/kg, i.p.) in mice that had lost the righting reflex. SCH 50911 (100 mg/kg, i.p.) also completely abolished the sedative/hypnotic effect of the GABA(B) receptor agonist, baclofen. These results indicate that the sedative/hypnotic effect of GHB is mediated by the stimulation of GABA(B) receptors and add further support to the hypothesis that the GABA(B) receptor constitutes a central site of action of GHB.


Subject(s)
Hydroxybutyrates/pharmacology , Hypnotics and Sedatives/pharmacology , Receptors, GABA-B/physiology , Animals , Anticonvulsants/pharmacology , Baclofen/pharmacology , Benzocycloheptenes/pharmacology , Dose-Response Relationship, Drug , GABA Agonists/pharmacology , GABA Antagonists/pharmacology , GABA-B Receptor Agonists , GABA-B Receptor Antagonists , Male , Mice , Mice, Inbred DBA , Morpholines/pharmacology , Reflex/drug effects
14.
Brain Res Brain Res Protoc ; 8(1): 74-81, 2001 Aug.
Article in English | MEDLINE | ID: mdl-11522530

ABSTRACT

The exogenous administration of gamma-hydroxybutyric acid (GHB), a constituent of the mammalian brain where it likely functions as a neurotransmitter or a neuromodulator, exerts a number of pharmacological effects, including sedation and hypnosis. The present paper describes a procedure for selective breeding of two rat lines which markedly differ in sensitivity to the sedative/hypnotic effect of GHB. Selective breeding originated from Wistar rats showing opposite sensitivity to the sedative/hypnotic effect of 1 g/kg GHB (i.p.). 'Sensitive' Wistar rats, defined as those individuals displaying values of r = sleep time/onset greater than the upper 15th percentile, were mated to generate the GHB-sensitive (GHB-S) line; conversely, 'resistant' Wistar rats (r-values lower than the lower 15th percentile) were mated to generate the GHB-resistant (GHB-R) line. Upper and lower 15th percentiles were also used to establish the selection cut-offs and criteria for rats of subsequent generations. Specifically, r-values of GHB-S rats were required to be r > or =8 on two separate tests with GHB; r-values of GHB-R rats were required to be r < or =2 on two separate tests with GHB. In each of the three generations produced to date, GHB-S rats showed significantly shorter onset, longer sleep times and greater r-scores than GHB-R rats. The selective breeding of GHB-S and GHB-R rats: (a) suggests that sensitivity to GHB is under genetic control, and (b) may constitute a unique model for investigation of the physiological function of GHB.


Subject(s)
Animal Husbandry/methods , Hypnotics and Sedatives/pharmacology , Rats/genetics , Sodium Oxybate/pharmacology , Animals , Drug Resistance , Female , Male , Rats/physiology , Rats, Wistar
15.
Brain Res ; 902(1): 127-30, 2001 May 25.
Article in English | MEDLINE | ID: mdl-11376602

ABSTRACT

Two Wistar-derived rat lines, one sensitive (GHB-S) and the other resistant (GHB-R) to the anesthetic effect of gamma-hydroxybutyric acid (GHB), have been selectively bred. GHB-S and GHB-R rats were also sensitive and resistant, respectively, to the anesthetic effect of baclofen, the prototype GABA(B) receptor agonist, suggesting that they may be useful to elucidate not only the role of endogenous GHB but also that of GABA(B) receptors in sleep and anesthesia.


Subject(s)
Anesthetics, Intravenous/pharmacology , Baclofen/pharmacology , Drug Resistance/genetics , GABA Agonists/pharmacology , GABA-B Receptor Agonists , Rats, Inbred Strains/genetics , Sodium Oxybate/pharmacology , Anesthesia Recovery Period , Animals , Breeding , Female , Male , Rats , Rats, Wistar , Receptors, GABA-B/physiology , Reflex/drug effects
16.
J Chromatogr B Biomed Sci Appl ; 751(1): 153-60, 2001 Feb 10.
Article in English | MEDLINE | ID: mdl-11232845

ABSTRACT

A reversed-phase high-performance liquid chromatography (HPLC) method with diode-array detection for the quantification of several human salivary peptides is described. Sample pretreatment consisted of the acidification of whole saliva by phosphate buffer. This treatment produced precipitation of mucins, alpha-amylases and other high-molecular-mass salivary proteins, simultaneous inhibition of intrinsic protease activities and reduction of sample viscosity. Direct HPLC analysis by diode-array detection of the resulting acidic sample allowed one to quantify histatin 1, histatin 3, histatin 5, statherin, as well as uric acid, in normal subjects. Moreover, the groups of peaks pertaining to proline-rich proteins and cystatins were tentatively identified. The method can be useful in assessing the concentration of salivary peptides from normal subjects and from patients suffering oral and/or periodontal diseases.


Subject(s)
Chromatography, High Pressure Liquid/methods , Phosphopeptides/analysis , Proteins/analysis , Salivary Proteins and Peptides/analysis , Acids , Buffers , Histatins , Humans , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
17.
Eur J Pharmacol ; 433(1): 101-4, 2001 Dec 14.
Article in English | MEDLINE | ID: mdl-11755139

ABSTRACT

The present study investigated the effect of the administration of the GABA(B) receptor antagonists, SCH 50911 [(2S)(+)-5,5-dimethyl-2-morpholineacetic acid], CGP 46381 [(3-aminopropyl)(cyclohexylmethyl)phosphinic acid] and CGP 52432 (3-[[(3,4-dichlorophenyl)methyl]amino]propyl]diethoxymethyl)phosphinic acid), on spontaneous locomotor activity in mice. All drugs were acutely administered at the doses of 10 and 30 mg/kg (i.p.). The dose of 30 mg/kg of all drugs resulted in a significant stimulation of locomotor activity. The locomotor stimulation elicited by SCH 50911 was completely blocked by haloperidol (0.1 mg/kg, i.p.), suggesting that hyperactivity induced by blockade of the GABA(B) receptor is mediated by enhanced dopamine release. These results suggest the existence of a GABA(B) receptor-mediated tonic inhibition of dopamine neurons.


Subject(s)
GABA Antagonists/pharmacology , GABA-B Receptor Antagonists , Motor Activity/drug effects , Animals , Benzylamines/pharmacology , Haloperidol/pharmacology , Male , Mice , Mice, Inbred DBA , Morpholines/pharmacology , Phosphinic Acids/pharmacology
18.
Allergy ; 47(4 Pt 2): 441-2, 1992 Aug.
Article in English | MEDLINE | ID: mdl-1456418

ABSTRACT

This study reports on the occurrence of an itchy dermatitis in all 4 adult members of a family, 2 men and 2 women, following infestation in the family environment with Gynaikothrips ficorum. The skin manifestations and the environmental study are described.


Subject(s)
Dermatitis/immunology , Insect Bites and Stings/immunology , Family Health , Female , Humans , Male , Pruritus/immunology
19.
J Chemother ; 3 Suppl 1: 222-3, 1991 Jan.
Article in English | MEDLINE | ID: mdl-12041770

ABSTRACT

The efficacy of teicoplanin and imipenem was assayed on microorganisms, mainly hospital opportunistic organisms, resistant to common therapy, isolated from bronchoaspirates of high risk hospitalized patients. Imipenem has shown remarkable activity against all isolated microorganisms with sensitivities ranging from 91.93% against Acinetobacter calcoaceticus to 75.86% against Pseudomonas sp. Teicoplanin has shown excellent activity against Staphylococcus aureus (sensitivity 83.66%).


Subject(s)
Acinetobacter Infections/drug therapy , Anti-Bacterial Agents/pharmacology , Imipenem/pharmacology , Pseudomonas Infections/drug therapy , Staphylococcal Infections/drug therapy , Teicoplanin/pharmacology , Thienamycins/pharmacology , Anti-Bacterial Agents/administration & dosage , Cross Infection/drug therapy , Drug Therapy, Combination , Humans , Imipenem/administration & dosage , Microbial Sensitivity Tests , Risk Factors , Teicoplanin/administration & dosage , Thienamycins/administration & dosage
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