26 research outputs found
Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world
Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic.
Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality.
Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States.
Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis.
Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection
The role of silica in radiation induced grafting and crosslinking of silica/elastomer blends
When silica/polybutadiene and silica/styrene-butadiene are submitted to g irradiation at 77 K a scavenging
of the silica radiolytic species by absorbed vinyl units takes place at the surface with concomitant
grafting and crosslinking of the polymers. Key intermediate in such reactions are SiO2-bonded radicals of
structure SiO2eC(CH3)CH(R)(R0). The role of silica is rationalized in terms of the following steps: a)
absorption of the radiation energy in the bulk of the silica particles followed by exciton migration at the
surface; b) reactions of excited groups (silanols) with absorbed vinyl units giving SiO2-bonded radicals; c)
crosslinking of the polymers initiated by grafted radicals
The role of inorganic sulfur compounds in the pyrolysis of Kraft lignin
In this study we have evaluated the production of gas during lignin pyrolysis under static vacuum con-ditions, the quantity of the most important gases produced, and the role of sulfur compounds. In fact,sulfates can act as oxidizers at the high temperature of pyrolysis (>200◦C) increasing the amount of car-bon dioxide formed. This is related to the detection of reduced volatile sulfur compounds by GC–MS. Wehave evaluated the decrease in the production of CO2and of reduced sulfur species after a simple acidtreatment for the removal of inorganic sulfates from the pristine lignin. The thermovolumetric analysis(TVA) was found as effective as thermogravimetric (TGA) one for the investigation of lignin pyrolysis
The role of inorganic sulfur compounds in the pyrolysis of Kraft lignin
In this study we have evaluated the production of gas during lignin pyrolysis under static vacuum con-ditions, the quantity of the most important gases produced, and the role of sulfur compounds. In fact,sulfates can act as oxidizers at the high temperature of pyrolysis (>200◦C) increasing the amount of car-bon dioxide formed. This is related to the detection of reduced volatile sulfur compounds by GC–MS. Wehave evaluated the decrease in the production of CO2and of reduced sulfur species after a simple acidtreatment for the removal of inorganic sulfates from the pristine lignin. The thermovolumetric analysis(TVA) was found as effective as thermogravimetric (TGA) one for the investigation of lignin pyrolysis
EXPERIMENTAL CHARACTERIZATION OF OIL-COLOPHONY VARNISHES: PROTECTION OF MUSICAL INSTRUMENTS
It is generally known as the wooden musical instruments are covered by varnish protective layers made by different organic compounds. Historically, the varnishes had the aim to protect the instrument by the external agents and to confer an aesthetic value to the object. During the 17th and 18th century, in Italy, all the violins were generally covered by a layer of varnish, made by a varnish based on linseed oil and colophony in the ratio 4:1 [1].
The main aim of this work was to study the modifications that occurred in ancient violin varnishes, after the exposure to some factors of degradation, as to be played by the violinist and the conditions in the context. In order to study the different properties of organic coating and their suitable compositions as a good varnish, a natural varnish which is a mixture of linseed oil and colophony used on the violins during the XVII century was recreated in the laboratory following an ancient recipe [2]. Here, for instance, linseed oil and colophony mixed together with different ratios (50/50 and 75/25, respectively) and then, they were applied on Maple wood samples and on glass slides for experimental purposes. Here, Maple wood was used, because it’s the same wood used for the back of the violin. In a common sense, it’s known as the playing routine of the musical instrument can perform different changes on the varnishes due to the contact with the player and the context, with a strong degradation of the organic layers and a consequent widespread worn-out of the varnish. Considering this effect, in order to investigate the properties of prepared varnish due to ageing, samples (treated wood and films on glasses) were exposed to different ageing cycles (humidity (RH%) /temperature (T), pH variations, and exposition to UV light). The performances of varnishes were evaluated handling color, contact angle, micro-FTIR, optical microscope, SEM-EDS, TGA and hardness analyses.
Out of strong experimental evaluation, all the results suggested that the composition of 75/25 (oil: colophony) is much better as a varnish for musical instruments.
[1] B. Brandmair, S.-P. Greiner. Stradivari Varnish.
[2] Manuscript It. III 10, f. 193v of Biblioteca Marciana di Venezia, title with "Segreti di arti diverse"