Oxygen Promoted On-Surface Synthesis of Polyboroxine Molecules.

We present our findings on the on-surface synthesis of polyboroxine molecules derived from boroxine molecules precursors. This process is promoted by oxygen species present on the Au(111) surface: oxygen atoms facilitate the detachment of naphthalene units of trinaphthyl-boroxine molecules and bridge two unsaturated boroxine centers to form a boroxine-O-boroxine chemical motif. X-ray spectroscopic characterization shows that, as the synthesis process proceeds, it progressively tunes the electronic properties of the interface, thus providing a promising route to control the electron level alignment. .

Lights and shadows on left atrial appendage occlusion: mind the gap in knowledge and think twice on long-term outcomes.

Ischemic stroke prevention represents a crucial concern in health systems, being associated with high morbidity and mortality. Atrial fibrillation is associated with 15-20% of ischemic strokes, in the presence of thrombus in the left atrial appendage in 90% of patients with nonvalvular atrial fibrillation. Oral anticoagulation represents the standard of care. However, left atrial appendage occlusions have been developed for selected patients with nonvalvular atrial fibrillation. With regard to the latter, particularly, some important concerns have been raised on the selection of patients potentially amenable to the procedure, seemingly emphasizing a gap in knowledge, real-life clinical practice, and current management guidelines. In light of the recent evidence regarding the current indications for management of left atrial appendage in presence of nonvalvular atrial fibrillation, the purpose of this critical review is to highlight the blind spots of left atrial appendage occlusion indications, taking into account the evidence-based mid- to long-term outcomes. Apparently, many unsolved concerns and problems are still present, mainly including mid- and long-term device-related potential complications, the possibility of concurrent sources of embolization, ethical and economic issues. Furthermore, larger, well designed, long-term, multicentric, and more inclusive studies, as well as shared/integrated registries are needed, aiming at comparing direct oral anticoagulation with left atrial appendage occlusion in the long run.

From ejection fraction, to myocardial strain, and myocardial work in echocardiography: Clinical impact and controversies.

Enhancing an echocardiographic tool, aimed to detect even subtle left ventricular (LV) systolic function abnormalities, capable of obtaining both early diagnosis and risk prediction of heart disease, represents an ambitious, attractive, and arduous purpose in the modern era of cardiovascular imaging. Ideally, that tool should be simple, reliable, and reproducible, in order to be concretely applied in routine clinical practice. Importantly, that technique should be physiologically plausible and useful both at the population-level, as well as in the individual subject. For a long time, LV ejection fraction (EF) has been considered the first-line parameter for assessing LV global systolic function, strictly related to the prognosis, at least in some settings. However, LV EF limitations are well-known, even though frequently overemphasized, including its load-dependency. Therefore, myocardial strain techniques have been proposed, deemed able to disclose even subtle early LV function anomalies. Nevertheless, many disadvantages of myocardial strain have been reported as well. More recently, myocardial work (MW) analysis has been introduced as a new echocardiographic tool for the evaluation of LV global systolic function, attempting to overcome EF and strain disadvantages. However, MW has shown many limits as well. Notwithstanding, LV EF still remains a landmark functional classification marker for heart failure and cardiac oncology, allowing reliable fast reassessment of LV function changes during patient management, in order to guide treatment in individual cases as well. Notably, global longitudinal strain and MW parameters seem to show better meaningful results at the population-level, but controversial clinical impact, major limitations, wide cut-offs spread and overlap, when the single value needs to be applied to the single case. Taking into account the recent literature-based evidence, the scope of the present narrative critical review is trying to delineate the different types of information given by the described LV global systolic function parameters, both at the population-level and in the individual case, in order to trace a comparative analysis of advantages and limitations in clinical practice.

Patent foramen ovale closure after cryptogenic stroke: sometimes uncertain benefit maybe, or even potential harm in the long run?

The main published studies on patent foramen ovale (PFO) closure after cryptogenic stroke tend to consider it positively, in light of the reported both procedural risk profile and outcomes. On the other hand, many blind spots and controversial issues of the topic are still present, mainly including both early procedural complications, and mid- and long-term associated comorbidities as well. Oftentimes, several biases appear to be present, with the evident risk of modifying indications for both intervention, and decision-making process. Biases should be considered and discussed during the diagnostic approach as well, including the supposed evidence of correlation, or cause-effect relationship, between the clinical event and patent foramen ovale. Furthermore, such studies have mostly shown results based on short-term follow-up and very low event rates. Conversely, those patients will keep the device lifelong, generally with long life expectancy, and the increased possibility of recurrent stroke from any other cause over time, along with many potential device-related comorbidities (e.g. atrial fibrillation, nearby anatomical structures impairment, and thrombosis). Consequently, it is hard to demonstrate the mid-term and long-term device-related advantages, due to the possible higher incidence of stroke associated with iatrogenic or concurrent factors. Thus, larger, well designed, long-term, multicentric, and more inclusive studies are needed, aimed to demonstrate a net clinical benefit, ideally including a number-needed-to-treat calculation at short-term, mid-term, and long-term, as well as taking into account and comparing the long-term complications, related outcomes, and recurrent events in patients with and without devices.

Examining need and capacity for the development of a pediatric liver transplantation program in Kenya.

BACKGROUND: In Africa, pediatric liver transplantation (PLT) is currently only performed in Egypt and South Africa, leaving those who require treatment in Kenya to travel abroad. The aim of this study was to determine whether sufficient capacity and need exists in Kenya to establish a safe and sustainable PLT program. METHODS: A descriptive analysis of the intensive care unit (ICU) beds, surgical workforce, current hepatobiliary volume, and estimated prevalence of pediatric liver disease (PLD) was conducted across 17 hospitals in Kenya between July and September 2020. Data were collected from medical superintendents, directors of surgical departments, or nominated proxies at Kenyan Level 5 and 6 hospitals via a web-based survey. RESULTS: A total of 165 ICU beds were reported at 17 facilities, with 15 facilities reporting five or more beds. About 39% of general surgeons at responding hospitals performed hepatobiliary procedures, and 30% performed pediatric surgeries. Only 10% of surgeons had pediatric training. Over half (57%) of hospitals performed hepatobiliary procedures; at the maximum, 1-5 cases were performed per week including cholecystectomy to Kasai portoenterostomy and hepatectomy. Across 13 hospitals, there were an estimated 192-570 cases of PLD seen per month. The most common PLDs were hepatitis B, neonatal hepatitis, cirrhosis, and acute hepatic failure. Overall, two hospitals possessed the minimum workforce and resources to attempt PLT. CONCLUSIONS: In Kenya, ICU bed availability, pediatric surgical training, and hepatobiliary volume are limited. However, the high prevalence of PLD demonstrated a significant need for PLT across all Kenyan hospitals.

Basic pathophysiology and options of treatment for surgical management of functional tricuspid regurgitation: a systematic review.

Background: Functional tricuspid regurgitation (TR) appears frequently in the presence of left-sided heart valve diseases, combined with symptoms of heart failure, worsens if left untreated, and is associated with poor patient survival. Correct indications for surgery and the choice of suitable technique, which should be based on pathophysiology of disease are of utmost importance to ensure longevity and durability of repair; particularly given the risky nature of reoperations due to residual/recurrent TR. Methods: A systematic review was performed using Embase, Ovid Medline, Cochrane, Web of Science, and Google to deepen knowledge of major and controversial aspects of the subject. Results: A total of 1,579 studies were reviewed, and 32 of these were enclosed in the final review: 13 studies were primarily focused on pathophysiology and preoperative assessment of functional TR; 19 studies on surgical treatment of functional TR. A total of 15,509 patients were included. Conclusions: Indications for treatment of TR are based on the severity of regurgitation (grading), as well as on the presence of signs and symtoms of right-sided heart failure and on the extent of tricuspid annular dilation, leaflet tethering, and pulmonary hypertension (staging of disease). Despite improved knowledge of the underlying pathophysiology of TR, issues regarding indications for treatment and options of repair remain present. There is no consensus within the scientific community, for the preferred method to quantify the severity of TR; the recently introduced 5-grade TR classification based on objective quantitative parameters has not yet become common practice. The assessment of TR during stress exercise is rarely performed, though it takes into account the changes in severity of regurgitation that occur under different physiological conditions. Magnetic resonance imaging, which is the gold standard for the right heart evaluation is occasionally carried out before surgery. The threshold beyond which the tricuspid annular dilation should be repaired is unclear and recent studies put forward the idea that it may be lower than current recommendations. Tricuspid valve annuloplasty is the most adopted surgical option today. However, the ideal annuloplasty device remains elusive. In addition, as severe leaflet tethering cannot be addressed by annuloplasty alone, the addition of new techniques further increasing leaflet coaptation might optimize long-term valve continence. Further investigations are needed to address all these issues, alongside the potential of percutaneous options.

Symmetry-resolved CO desorption and oxidation dynamics on O/Ru(0001) probed at the C K-edge by ultrafast x-ray spectroscopy.

We report on carbon monoxide desorption and oxidation induced by 400 nm femtosecond laser excitation on the O/Ru(0001) surface probed by time-resolved x-ray absorption spectroscopy (TR-XAS) at the carbon K-edge. The experiments were performed under constant background pressures of CO (6 × 10-8 Torr) and O2 (3 × 10-8 Torr). Under these conditions, we detect two transient CO species with narrow 2π* peaks, suggesting little 2π* interaction with the surface. Based on polarization measurements, we find that these two species have opposing orientations: (1) CO favoring a more perpendicular orientation and (2) CO favoring a more parallel orientation with respect to the surface. We also directly detect gas-phase CO2 using a mass spectrometer and observe weak signatures of bent adsorbed CO2 at slightly higher x-ray energies than the 2π* region. These results are compared to previously reported TR-XAS results at the O K-edge, where the CO background pressure was three times lower (2 × 10-8 Torr) while maintaining the same O2 pressure. At the lower CO pressure, in the CO 2π* region, we observed adsorbed CO and a distribution of OC-O bond lengths close to the CO oxidation transition state, with little indication of gas-like CO. The shift toward "gas-like" CO species may be explained by the higher CO exposure, which blocks O adsorption, decreasing O coverage and increasing CO coverage. These effects decrease the CO desorption barrier through dipole-dipole interaction while simultaneously increasing the CO oxidation barrier.

Photo-induced lattice distortion in 2H-MoTe2 probed by time-resolved core level photoemission.

The technological interest in MoTe2 as a phase engineered material is related to the possibility of triggering the 2H-1T' phase transition by optical excitation, potentially allowing for an accurate patterning of metallic areas into a semiconducting canvas via laser irradiation. In this paper, we investigate the photo-induced modifications of a bulk 2H-MoTe2 crystal by means of time-resolved X-ray photoemission spectroscopy. We observe that in the microsecond timescale, the core levels shift to higher kinetic energies due to surface photovoltage fields, while in the sub-nanosecond range, the photoemission peaks shift in the opposite direction. With the support of DFT calculations, we ascribe the latter effect to the deformation of the lattice in the out-of-plane direction, which is along the pathway for the 2H-1T' phase transition. Our data indicate an intermediate lattice excitation state with a measured lifetime in the order of 600 ps, in which the displacement of Mo and Te atoms causes the Te 4d electrons to shift towards higher binding energies.

Artificial intelligence applied to cardiovascular imaging, a critical focus on echocardiography: The point-of-view from "the other side of the coin".

Cardiovascular imaging has achieved a crucial role in the management of cardiovascular diseases. In this field, echocardiography advantages include wide availability, portability, and affordability, at a relatively low cost. However, echocardiographic assessment requires highly trained operators, and implies high observer variability, as compared with the other cardiac imaging modalities. Hence, artificial intelligence might be extremely helpful. From the point-of-view of the peripheral "Spoke" Hospital potential user ("the other side of the coin"), artificial intelligence development appears very slow in the clinical arena. Many limitations are still present, and require full involvement, cooperation, and coordination of professional operators into Hub-and-Spoke network.

Atom-Specific Probing of Electron Dynamics in an Atomic Adsorbate by Time-Resolved X-Ray Spectroscopy.

The electronic excitation occurring on adsorbates at ultrafast timescales from optical lasers that initiate surface chemical reactions is still an open question. Here, we report the ultrafast temporal evolution of x-ray absorption spectroscopy (XAS) and x-ray emission spectroscopy (XES) of a simple well-known adsorbate prototype system, namely carbon (C) atoms adsorbed on a nickel [Ni(100)] surface, following intense laser optical pumping at 400 nm. We observe ultrafast (∼100 fs) changes in both XAS and XES showing clear signatures of the formation of a hot electron-hole pair distribution on the adsorbate. This is followed by slower changes on a few picoseconds timescale, shown to be consistent with thermalization of the complete C/Ni system. Density functional theory spectrum simulations support this interpretation.

Reshaping of Italian Echocardiographic Laboratories Activities during the Second Wave of COVID-19 Pandemic and Expectations for the Post-Pandemic Era.

BACKGROUND: Cardiology divisions reshaped their activities during the coronavirus disease 2019 (COVID-19) pandemic. This study aimed to analyze the organization of echocardiographic laboratories and echocardiography practice during the second wave of the COVID-19 pandemic in Italy, and the expectations for the post-COVID era. METHODS: We analyzed two different time periods: the month of November during the second wave of the COVID-19 pandemic (2020) and the identical month during 2019 (November 2019). RESULTS: During the second wave of the COVID-19 pandemic, the hospital activity was partially reduced in 42 (60%) and wholly interrupted in 3 (4%) echocardiographic laboratories, whereas outpatient echocardiographic activity was partially reduced in 41 (59%) and completely interrupted in 7 (10%) laboratories. We observed an important change in the organization of activities in the echocardiography laboratory which reduced the operator-risk and improved self-protection of operators by using appropriate personal protection equipment. Operators wore FFP2 in 58 centers (83%) during trans-thoracic echocardiography (TTE), in 65 centers (93%) during transesophageal echocardiography (TEE) and 63 centers (90%) during stress echocardiography. The second wave caused a significant reduction in number of echocardiographic exams, compared to November 2019 (from 513 ± 539 to 341 ± 299 exams per center, -34%, p < 0.001). On average, there was a significant increase in the outpatient waiting list for elective echocardiographic exams (from 32.0 ± 28.1 to 45.5 ± 44.9 days, +41%, p < 0.001), with a reduction of in-hospital waiting list (2.9 ± 2.4 to 2.4 ± 2.0 days, -17%, p < 0.001). We observed a large diffusion of point-of-care cardiac ultrasound (88%), with a significant increase of lung ultrasound usage in 30 centers (43%) during 2019, extended to all centers in 2020. Carbon dioxide production by examination is an indicator of the environmental impact of technology (100-fold less with echocardiography compared to other cardiac imaging techniques). It was ignored in 2019 by 100% of centers, and currently it is considered potentially crucial for decision-making in cardiac imaging by 65 centers (93%). CONCLUSIONS: In one year, major changes occurred in echocardiography practice and culture. The examination structure changed with extensive usage of point-of-care cardiac ultrasound and with lung ultrasound embedded by default in the TTE examination, as well as the COVID-19 testing.

Ultrafast Adsorbate Excitation Probed with Subpicosecond-Resolution X-Ray Absorption Spectroscopy.

We use a pump-probe scheme to measure the time evolution of the C K-edge x-ray absorption spectrum from CO/Ru(0001) after excitation by an ultrashort high-intensity optical laser pulse. Because of the short duration of the x-ray probe pulse and precise control of the pulse delay, the excitation-induced dynamics during the first picosecond after the pump can be resolved with unprecedented time resolution. By comparing with density functional theory spectrum calculations, we find high excitation of the internal stretch and frustrated rotation modes occurring within 200 fs of laser excitation, as well as thermalization of the system in the picosecond regime. The ∼100 fs initial excitation of these CO vibrational modes is not readily rationalized by traditional theories of nonadiabatic coupling of adsorbates to metal surfaces, e.g., electronic frictions based on first order electron-phonon coupling or transient population of adsorbate resonances. We suggest that coupling of the adsorbate to nonthermalized electron-hole pairs is responsible for the ultrafast initial excitation of the modes.

Multimodality imaging evaluation of multilobulated subvalvular aortic aneurysm involving the membranous ventricular septum.

We report a rare clinical case of multilobulated subvalvular aortic aneurysm located in the left ventricular outflow tract, involving the membranous ventricular septum, and associated with mild prolapse of the noncoronary aortic leaflet, emphasizing the importance of multimodality imaging approach, and multidisciplinary discussion.

Implantation of a Sutureless Valve Into a Surgically Enlarged Aortic Root: A Bailout Option.

Sutureless bioprostheses such as the Sorin Perceval Valve (SPV; Sorin Group, Srl, Saluggia, Italy) have been proposed for replacing stenotic native valves within small aortic roots of geriatric patients with significant comorbidity. Their use seems as safe as that of stented bioprostheses and enables significantly reduced length of surgery. Low transprosthetic pressure gradients have been measured. Because of the radial force of its self-expandable nitinol stent, aortic annulus interruption could be a relative contraindication to SPV use. Off-label implantation of the SPV into a surgically enlarged ascending aorta was first reported in this study, as a bailout option in the presence of a tiny aortic root.

Health-related quality of life after anonymous nondirected living liver donation: A multicenter collaboration.

Literature on living nondirected liver donation is sparse. The purpose of this study was to assess health-related quality of life (HR-QOL) in anonymous nondirected living liver donors (ND-LLDs). ND-LLDs at 3 centers: University of Alberta (n = 12), University of Colorado (n = 12), and University of Southern California (n = 12), were surveyed. Thirty donors (83%) responded to the Donor Quality of Life (USC DQLS) and Short-Form 36 (SF-36). Most respondents (n = 15, 50%) donated their left lateral segment, 27% right lobe, and 23% left lobe. The majority were female (67%) and mean age was 38.9 ± 11.2 years at donation. Median follow-up was 1.1 (interquartile range 0.4-3.3) years. Approximately 37% had previously donated a kidney. Eleven experienced ≥1 postoperative complication, with only 1 Clavien-Dindo IIIb. Most reported minimal impact on school or work performance, all felt positive or neutral about their overall health since donation, and none expressed postdonation regrets. No donor reported impacts on health insurability, and 3 of 4 respondents attempting to purchase life insurance postdonation were successful. ND-LLD SF-36 outcomes were similar to US population norms. Overall, ND-LLDs demonstrated acceptable HR-QOL after donation and are appropriate candidates for partial liver donation. Based on evaluation of donation impact, consideration should be given to postdonation support strategies.