The present study aimed to assess the prevalence and incidence rate of pulmonary arterial hypertension (PAH) in Systemic Sclerosis (SSc). The review was undertaken using MEDLINE and SCOPUS from June ...1962 to May 2019 and the terms: (“Scleroderma, Systemic”MesH) AND “Hypertension, Pulmonary”MesH. The Newcastle-Ottawa Scale (NOS) was used for the qualifying assessment. The inverse variance-weighted method was performed. Twenty-four studies were included in the global PAH prevalence study. They comprised data from 9804 SSc patients. The overall PAH prevalence found was 6.4% (95%CI 5%–8.3%). Fourteen studies were included in the PAH prevalence study for lcSSc. They comprised data from 4987 lcSSc patients. The PAH prevalence found in lcSSc was 7.7% (95%CI 5.3%–11.1%). Twelve studies were included in the PAH prevalence study for dcSSc. They comprised data from 1790 dcSSc patients. The PAH prevalence found in dcSSc was 6.3% (95%CI 4.5%–8.9%). Fifteen studies showed PAH incidence of an entire SSc cohort. They comprised data from 5926 SSc patients. The overall PAH incidence found was 18.2 cases per 1000 person-years (95%CI 12–27.4). Eight studies showed PAH incidence for lcSSc. They comprised data from 2721 patients. The overall PAH incidence found in lcSSc was 20.4 cases per 1000 person-years (95%CI 10.1–41.1). Seven studies showed PAH incidence for dcSSc. They comprised data from 942 dcSSc patients. The overall PAH incidence found in dcSSc was 16.6 cases per 1000 person-years (95%CI 8.5–32.1).
The overall PAH prevalence found was 6.4% (95%CI 5%–8.3%) and the overall PAH incidence 18.2 cases per 1000 person-years (95%CI 12–27.4).
•The overall PAH prevalence is 6.4% (95%CI 5%–8.3%).•The PAH prevalence in lcSSc was 7.7% (95%CI 5.3–11.1) and in dcSSc 6.3% (95%CI 4.5–8.9).•The overall PAH incidence 18.2 cases per 1,000 person-years (95%CI 12–27.4).•The PAH incidence in lcSSc was 20.4 cases per 1,000 person-years (95%CI 10.1–41.1) and in dcSSc 16.6 cases per 1,000 person-years (95%CI 8.5–32.1).
Present experiments show that synthesized polycrystalline hexagonal α-Mo2C is a highly efficient and selective catalyst for CO2 uptake and conversion to CO through the reverse water gas shift ...reaction. The CO2 conversion is ∼16% at 673 K, with selectivity toward CO > 99%. CO2 and CO adsorption is monitored by DRIFTS, TPD, and microcalorimetry, and a series of DFT based calculations including the contribution of dispersion terms. The DFT calculations on most stable model surfaces allow for identifying numerous binding sites present on the catalyst surface, leading to a high complexity in measured and interpreted IR- and TPD-spectra. The computational results also explain ambient temperature CO2 dissociation toward CO as resulting from the presence of surface facets such as Mo2C(201)-Mo/Cdisplaying Mo and C surface atomsand Mo-terminated Mo2C(001)-Mo. An ab initio thermodynamics consideration of reaction conditions, however, demonstrates that these facets bind CO2 and CO + O intermediates too strongly for a subsequent removal, whereas the Mo2C(101)-Mo/C exhibits balanced binding properties, serving as a possible explanation of the observed reactivity. In summary, results show that polycrystalline α-Mo2C is an economically viable, highly efficient, and selective catalyst for CO generation using CO2 as a feedstock.
Corticosteroids are largely recommended in patients with severe COVID-19. However, evidence to support high-dose methylprednisolone (MP) pulses is not as robust as that demonstrated for low-dose ...dexamethasone (DXM) in the RECOVERY trial. This is a retrospective cohort study on severe, non-critically ill patients with COVID-19, comparing 3-day MP pulses ≥ 100 mg/day vs. DXM 6 mg/day for 10 days. The primary outcome was in-hospital mortality, and the secondary outcomes were need of intensive care unit (ICU) admission or invasive mechanical ventilation (IMV). Propensity-score matching (PSM) analysis was applied. From March 2020 to April 2021, a total of 2,284 patients were admitted to our hospital due to severe, non-critically ill COVID-19, and of these, 189 (8.3%) were treated with MP, and 493 (21.6%) with DXM. The results showed that patients receiving MP showed higher in-hospital mortality (31.2% vs. 17.8%, p < 0.001), need of ICU admission (29.1% vs. 20.5%, p = 0.017), need of IMV (25.9% vs. 13.8, p < 0.001), and median hospital length of stay (14 days vs. 11 days, p < 0.001). Our results suggest that treatment with low-dose DXM for 10 days is superior to 3 days of high-dose MP pulses in preventing in-hospital mortality and need for ICU admission or IMV in severe, non-critically ill patients with COVID-19.
The ethanol steam-reforming reaction was studied by in situ diffuse reflectance infrared Fourier transform spectroscopy and on-line mass spectrometry over ZnO and a Co/ZnO catalyst prepared from ...impregnation of Co
2(CO)
8. Acetaldehyde is the primary product. The presence of cobalt favors the reforming of acetaldehyde, via the C
C scission of bidentate acetate species. Dimethyl ketone is produced as a by-product on ZnO. The roles of ZnO support and cobalt are discussed on the basis of surface species and their subsequent evolution.
A series of complex organic-inorganic mesoporous materials were successfully synthesized by a microwave-assisted method that allowed the preparation of periodic mesoporous organosilicas (PMOs) with ...Ti (IV) forming part of the structure (Ti-PMOs). Materials were characterized using N2 adsorption–desorption isotherms, powder X-ray diffraction (XRD), transmission and high resolution transmission electron microscopy (TEM and HRTEM), Raman, infrared, UV–visible diffuse reflectance (UV–vis RDS), X-ray photoelectron (XPS), photoluminescence (PL) and electrochemical impedance (EIS) spectroscopy, and transient photocurrent measurements. Samples labeled Ti10-PMO, Ti20-PMO and Ti40-PMO (with Si/Ti molar ratio of about 10, 20 and 40), showed crystal-like characteristics and high specific surface area (742–829 m2g-1). Ti-PMOs were studied in the photocatalytic H2 evolution from an aqueous ethanol solution under UV–visible irradiation. Ti-PMOs showed a better photocatalytic behavior than PMO and this is related with the presence of tetrahedral Ti(IV) in the PMOs network. Ti-PMOs displayed a lower barrier for the electron transfer and a more efficient charge separation than PMO. The highest H2 production was obtained with Ti20-PMO photocatalyst; after 4 h of irradiation, 2042 μmol H2 gcat−1 were obtained, which was about 20 times higher than that obtained with a reference commercial TiO2 (P25).
The effect of sodium promoter on cobalt–zinc oxide catalysts was studied. Catalysts with different sodium contents (up to 1% (w/w)) were prepared by a coprecipitation method. They were studied in the ...steam reforming of ethanol between 523 and 723 K and characterized by transmission electron microscopy, X-ray diffraction, Raman and infrared spectroscopies, X-ray photoelectron spectroscopy, and in situ diffuse reflectance infrared spectroscopy. A high segregation of sodium on the surface of catalysts took place. The sodium addition had a positive effect on the steam-reforming reaction of ethanol. Under total conversion and in the 623–723 K temperature range, the production of hydrogen from an ethanol–water (C
2H
5OH:H
2O=1:13 molar) mixture (bioethanol) increased (5–8%) with sodium content. In addition, the incorporation of sodium resulted in the stabilization of the catalysts toward deactivation. In particular, the sodium-promoter effect was related to a decrease in carbon deposition, as evidenced by transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy.
This paper focuses on the effect of Ru and Rh addition to SiO2-supported Co catalysts for the oxidative steam reforming of ethanol to produce hydrogen. Catalysts were tested in the reaction at ...atmospheric pressure and 623-673 K and characterized by X-ray diffraction, temperature-programmed reduction, X-ray photoelectron spectroscopy, and infrared spectroscopy with CO as the probe molecule. A synergistic effect between Co and Rh or Ru was seen in the oxidative steam reforming of ethanol. A study of the deactivation/regeneration of catalysts found that an oxidizing treatment recovered the performance of deactivated bimetallic catalysts. This process could be used in cycles to optimize both ethanol conversion and selectivity toward hydrogen production. PUBLICATION ABSTRACT
The transformation of Co3O4 during steam-re-forming of ethanol was investigated at atmospheric pressure in the 523−673 K temperature range using a bioethanol-like mixture. The initial and after ...reaction materials were characterized by the Brunauer−Emmett−Teller method, X-ray diffraction, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy, and in situ magnetic measurements. The performance in the ethanol steam-re-forming of the initial material and of those materials obtained under the reaction conditions was determined. During the activation process, in situ magnetic measurements and catalytic evaluation were carried out simultaneously. At 573 K, ethanol is dehydrogenated to acetaldehyde over Co3O4. At higher temperatures, Co3O4 is reduced to CoO and small metallic cobalt particles. Simultaneously, the material becomes active for the ethanol steam-re-forming reaction. Up to 5.2 mol of H2/mol of ethanol is obtained at temperatures as low as 623 K, and only methane (<3%) is obtained besides hydrogen (>72%) and carbon dioxide (>25%).
Transition metal carbides of group 5 (G5TMC=VC, NbC and TaC) with similar crystallite sizes were prepared by a sol-gel route. The catalysts were characterized and studied in the methanol steam ...reforming (MSR) reaction in the temperature range of 573–723 K at atmospheric pressure and using a stoichiometric CH3OH/H2O = 1/1 mole ratio mixture. Under the MSR reaction conditions used, the route of methanol transformation depends on the G5TMC used as catalyst. The catalytic behaviour of VC differs from that of NbC and TaC, which in turn show a similar behaviour. Over VC, methanol is mainly converted to a mixture of H2+CH4, whereas over NbC and TaC the major product obtained is HCHO, formed from the dehydrogenation of methanol.
•Group 5 transition metal carbides as catalysts in the methanol steam reforming.•Methanol steam reforming over VC, NbC and TaC polycrystalline catalysts.•H2+CH4 mixtures are obtained under MSR over VC catalyst.•HCHO is obtained under MSR over NbC and TaC catalysts.
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