Preliminary Cleaning Approach with Alginate and Konjac Glucomannan Polysaccharide Gel for the Surfaces of East Asian and Western String Musical Instruments.

The cleaning of string musical instruments is challenging due to the traditional finishing treatments used by the makers. Multilayered coating systems were applied to Western musical instruments, while the Nakdong technique was applied in East Asia. Furthermore, by restorations and performance, dust and grime were overlapped together with polishes, adhesives, and varnishes. Gel cleaning is important in the field of conservation because of the ability to selectively remove chemical and biological degradation products from the surface, minimizing the interactions with the inner layers. In this study, hydrogels based on sodium alginate (SA) and konjac glucomannan (KG) polysaccharides were applied on laboratory mock-ups of East Asian and Western instruments to test their ability to remove synthetic soiling and sweat from the surface. In particular, SA cross-linked with calcium cations and KG cross-linked with borate gels were used. To control the exposure of the cleaning solvent on the surface of mock-ups, the moisture content of the gels was determined. The effectiveness of removing synthetic contaminants was investigated by noninvasive analytical methods. Stereomicroscopy and colorimetry, together with Fourier Transform Infrared (FTIR) spectroscopy in reflection mode and X-Ray Fluorescence (XRF), were used to evaluate the cleaning efficacy. Overall, polysaccharide hydrogels resulted in promising cleaning systems on both smooth and rough surfaces of wood.

Chemical composition and radiative forcing of atmospheric aerosols over the high-altitude Western Himalayas of India.

Aerosol behavior over the Himalayas plays an important role in the regional climate of South Asia. Previous studies at high-altitude observatories have provided evidence of the impact of long-range transport of pollutants from the Indo-Gangetic Plain (IGP). However, little information exists for the valley areas in the high Himalayas where significant local anthropogenic emissions can act as additional sources of short-living climate forcers and pollutants. The valley areas host most economic activities based on agriculture, forestry, and pilgrimage during every summer season. We report here first measurements at a valley site at ~2600 m a.s.l. on the trek to the Gangotri glacier (Gaumukh), in the Western Himalayas, where local infrastructures for atmospheric measurements are absent. The study comprised short-term measurement of aerosols, chemical characterization, and estimation of aerosol radiative forcing (ARF) during the winter and summer periods (2015-2016). The particulate matter mass concentrations were observed to be higher than the permissible limit during the summer campaigns. We obtained clear evidence of the impact of local anthropogenic sources: particulate nitrate is associated with coarse aerosol particles, the black carbon (BC) mass fraction appears undiluted with respect to measurements performed in the lower Himalayas, and in winter, both BC and sulfate concentrations in the valley site are well above the background levels reported from literature studies for mountain peaks. Finally, high concentrations of trace metals such as copper point to anthropogenic activities, including combustion and agriculture. While most studies in the Himalayas have addressed pollution in the high Himalayas in terms of transport from IGP, our study provides clear evidence that local sources cannot be overlooked over the high-altitude Himalayas. The estimated direct clear-sky ARF was estimated to be in the range of -0.1 to +1.6 W m-2, with significant heating in the atmosphere over the high-altitude Himalayan study site. These results indicate the need to establish systematic aerosol monitoring activities in the high Himalayan valleys.

Biopolymer Gels as a Cleaning System for Differently Featured Wooden Surfaces.

The cleaning of some wooden artefacts can be challenging due to peculiar surface roughness and/or particular finishing treatments that favour the deposition of dirt and contaminants. The most common cleaning system used by conservators is agar gel, characterized by its rigidity and brittleness, which challenges the cleaning of rough and irregular surfaces typical of most wooden artefacts. In this work, alginate crosslinked with calcium (CA) and konjac glucomannan crosslinked with borax (KGB) gels were proposed to solve this issue. They were prepared and applied to smooth- and rough-surfaced mock-ups replicating wooden musical instruments' surfaces that had been subsequently covered by artificial soiling and sweat contaminants. The mechanical properties of CA and KGB gels, including their stability over a 60-day storage time, were evaluated by a texture analyzer, while cleaning efficacy was analytically evaluated by non-invasive X-ray fluorescence mapping and profilometric investigation. CA gel appeared to have a higher tensile strength and elongation at break. KGB gel was shown to be soft and resilient, indicating its suitability for cleaning rough surfaces. After repeating the cleaning application three times on the rough-surfaced mock-ups, both the CA and KGB gels were shown to have cleaning efficacy. The results obtained with CA and KGB were compared with those from the Agar application.

Levosimendan to facilitate weaning from cardiorespiratory support in critically ill patients: current evidence and future directions.

Appropriate weaning is of crucial importance for critically ill patients requiring respiratory support. However, a remarkable proportion of them are difficult to wean. Levosimendan is a positive inotropic agent characterized by vasodilatory properties, which is used for the treatment of acute decompensated heart failure or in patients needing inotropic treatment, including cardiogenic shock, septic shock, pulmonary hypertension and right ventricular dysfunction, needed for hemodynamic support in patients with diuretic resistance, and weaning either from ventilator or from extracorporeal membrane oxygenation. This position paper will discuss the use of levosimendan in facilitating weaning from cardiorespiratory support in critically ill patients, according to available evidence and the personal experience of a group of Italian Experts.

Early Versus Late Tracheostomy in Cardiac Surgical Patients: A 12-Year Single Center Experience.

OBJECTIVES: To evaluate whether early tracheostomy is associated with better outcomes in mechanical ventilation-dependent patients after cardiac surgery compared with a late tracheostomy. DESIGN: Retrospective, observational study. SETTING: Cardiac surgical intensive care unit (ICU) of a tertiary care center. PARTICIPANTS: All patients who underwent tracheostomy after cardiac surgery between 2004 and 2015 were subdivided into the following 2 groups according to the timing of tracheostomy: "early" if the tracheostomy was performed before the 14th postoperative day and "late" from the 14th postoperative day onward. INTERVENTIONS: Early versus late tracheostomy. MEASUREMENTS AND MAIN RESULTS: During the study period, 112 of 5,148 patients (2.2%) underwent tracheostomy after cardiac surgery. Early tracheostomy was performed in 62 patients, and 50 patients underwent late tracheostomy. Both groups of patients were similar in terms of preoperative and intraoperative characteristics, perioperative risk, and postoperative complications. Patients in the early group had a significantly shorter ventilation time (31.3 ± 23.6 v 39.4 ± 22.4 d; p = 0.034), shorter ICU stay (37.7 ± 21.7 v 46.4 ± 25 d; p = 0.025), and a shorter hospital stay (53.4 ± 29.3 v 66.8 ± 38.5 d; p = 0.020). There were no intergroup differences in weaning rates and in-hospital, 3-month, and 1- and 2-year mortality. CONCLUSIONS: In this study, early tracheostomy after cardiac surgery in patients requiring prolonged mechanical ventilation was associated with a shorter ventilation time and ICU and hospital stay, but did not result in a lower in-hospital and long-term mortality rate.