First-principles extrapolation method for accurate CO adsorption energies on metal surfaces

We show that a simple first-principles correction based on the difference between the singlet-triplet CO excitation energy values obtained by DFT and high-level quantum chemistry methods yields accurate CO adsorption properties on a variety of metal surfaces. We demonstrate a linear relationship between the CO adsorption energy and the CO singlet-triplet splitting, similar to the linear dependence of CO adsorption energy on the energy of the CO 2$\pi$* orbital found recently {[Kresse {\em et al.}, Physical Review B {\bf 68}, 073401 (2003)]}. Converged DFT calculations underestimate the CO singlet-triplet excitation energy $\Delta E_{\rm S-T}$, whereas coupled-cluster and CI calculations reproduce the experimental $\Delta E_{\rm S-T}$. The dependence of $E_{\rm chem}$ on $\Delta E_{\rm S-T}$ is used to extrapolate $E_{\rm chem}$ for the top, bridge and hollow sites for the (100) and (111) surfaces of Pt, Rh, Pd and Cu to the values that correspond to the coupled-cluster and CI $\Delta E_{\rm S-T}$ value. The correction reproduces experimental adsorption site preference for all cases and obtains $E_{\rm chem}$ in excellent agreement with experimental results.Comment: Table sent as table1.eps. 3 figure

Stability of sub-surface oxygen at Rh(111)

Using density-functional theory (DFT) we investigate the incorporation of oxygen directly below the Rh(111) surface. We show that oxygen incorporation will only commence after nearly completion of a dense O adlayer (\theta_tot = 1.0 monolayer) with O in the fcc on-surface sites. The experimentally suggested octahedral sub-surface site occupancy, inducing a site-switch of the on-surface species from fcc to hcp sites, is indeed found to be a rather low energy structure. Our results indicate that at even higher coverages oxygen incorporation is followed by oxygen agglomeration in two-dimensional sub-surface islands directly below the first metal layer. Inside these islands, the metastable hcp/octahedral (on-surface/sub-surface) site combination will undergo a barrierless displacement, introducing a stacking fault of the first metal layer with respect to the underlying substrate and leading to a stable fcc/tetrahedral site occupation. We suggest that these elementary steps, namely, oxygen incorporation, aggregation into sub-surface islands and destabilization of the metal surface may be more general and precede the formation of a surface oxide at close-packed late transition metal surfaces.Comment: 9 pages including 9 figure files. Submitted to Phys. Rev. B. Related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.htm

The economic impact of moderate stage Alzheimer's disease in Italy: Evidence from the UP-TECH randomized trial

Background: There is consensus that dementia is the most burdensome disease for modern societies. Few cost-of-illness studies examined the complexity of Alzheimer's disease (AD) burden, considering at the same time health and social care, cash allowances, informal care, and out-of-pocket expenditure by families. Methods: This is a comprehensive cost-of-illness study based on the baseline data from a randomized controlled trial (UP-TECH) enrolling 438 patients with moderate AD and their primary caregiver living in the community. Results: The societal burden of AD, composed of public, patient, and informal care costs, was about �20,000/yr. Out of this, the cost borne by the public sector was �4,534/yr. The main driver of public cost was the national cash-for-care allowance (�2,324/yr), followed by drug prescriptions (�1,402/yr). Out-of-pocket expenditure predominantly concerned the cost of private care workers. The value of informal care peaked at �13,590/yr. Socioeconomic factors do not influence AD public cost, but do affect the level of out-of-pocket expenditure. Conclusion: The burden of AD reflects the structure of Italian welfare. The families predominantly manage AD patients. The public expenditure is mostly for drugs and cash-for-care benefits. From a State perspective in the short term, the advantage of these care arrangements is clear, compared to the cost of residential care. However, if caregivers are not adequately supported, savings may be soon offset by higher risk of caregiver morbidity and mortality produced by high burden and stress. The study has been registered on the website www.clinicaltrials.org (Trial Registration number: NCT01700556). Copyright � International Psychogeriatric Association 2015

Readiness to deliver person‐focused care in a fragile situation: the case of Mental Health Services in Lebanon

Background: Evidence suggests wide variability in the provision of mental healthcare across countries. Countries experiencing fragility related risks suffer from a high burden of mental-ill health and additionally have limited capacity to scale up mental health services given financial and human resource shortages. Integration of mental health services into routine primary care is one potential strategy for enhancing service availability, however little is known about the experiences of currently active health care providers involved in mental health and psychosocial support service (MHPSS) provision at primary care level. This study aims to determine how healthcare providers offering MHPSS services at primary care levels in Lebanon perceive mental health and the health system’s ability to address the rising mental ill-health burden with a view to identify opportunities for strengthening MHPSS service implementation geared towards integrated person focused care model. Methods: A qualitative study design was adopted including 15 semi-structured interviews and 2 participatory group model-building workshops with health care providers (HCPs) involved in mental healthcare delivery at primary care level. Participants were recruited from two contrasting fragility contexts (Beirut and Beqaa). During workshops, causal loop diagrams depicting shared understandings of factors leading to stress and mental ill health, associated health seeking behaviors, and challenges and barriers within the health system were elicited. This research is part of a larger study focused on understanding the dynamics shaping mental health perceptions and health seeking behaviours among community members residing in Lebanon. Results: Findings are organized around a causal loop diagram depicting three central dynamics as described by workshop participants. First, participants linked financial constraints at household levels and the inability to secure one’s livelihood with contextual socio-political stressors, principally referring to integration challenges between host communities and Syrian refugees. In a second dynamic, participants linked exposure to war, conflict and displacement to the occurrence of traumatic events and high levels of distress as well as tense family and community relations. Finally, participants described a third dynamic linking cultural norms and patriarchal systems to exposure to violence and intergenerational trauma among Lebanon’s populations. When describing help-seeking pathways, participants noted the strong influence of social stigma within both the community and among health professionals; the latter was noted to negatively affect patient-provider relationships. Participants additionally spoke of difficulties in the delivery of mental health services and linked this to the design of the health system itself, noting the current system being geared towards patient centered care, which focuses on the patient’s experiences with a disease only, rather than person focused care where providers and patients acknowledge broader structural and social influences on health and work together to reach appropriate decisions for tackling health and other social needs. Barriers to delivery of person focused care include the lack of coherent mental health information systems, limited human capacity to deliver MHPSS services among primary health care staff and inadequate service integration and coordination among the many providers of mental health services in our study contexts. Critically however, provider accounts demonstrate readiness and willingness of health professionals to engage with integrated person focused care models of care. Conclusions: Mental ill health is a major public health problem with implications for individual health and wellbeing; in a fragile context such as Lebanon, the burden of mental ill health is expected to rise and this presents substantive challenges for the existing health system. Concrete multi-sectoral efforts and investments are required to (1) reduce stigma and improve public perceptions s rrounding mental ill health and associated needs for care seeking and (2) promote the implementation of integrated person focused care for addressing mental health. © 2021, The Author(s)

Obesity and immune function relationships.

The immunological processes involved in the collaborative defence of organisms are affected by nutritional status. Thus, a positive chronic imbalance between energy intake and expenditure leads to situations of obesity, which may influence unspecific and specific immune responses mediated by humoral and cell mediated mechanisms. Furthermore, several lines of evidence have supported a link between adipose tissue and immunocompetent cells. This interaction is illustrated in obesity, where excess adiposity and impaired immune function have been described in both humans and genetically obese rodents. However, limited and often controversial information exist comparing immunity in obese and non-obese subjects as well as about the cellular and molecular mechanisms implicated. In general terms, clinical and epidemiological data support the evidence that the incidence and severity of specific types of infectious illnesses are higher in obese persons as compared to lean individuals together with the occurrence of poor antibody responses to antigens in overweight subjects. Leptin might play a key role in linking nutritional status with T-cell function. The complexities and heterogeneity of the host defences concerning the immune response in different nutritional circumstances affecting the energy balance require an integral study of the immunocompetent cells, their subsets and products as well as specific and unspecific inducer/regulator systems. In this context, more research is needed to clarify the clinical implications of the alterations induced by obesity on the immune function

Dynamics of non-communicable disease prevention, diagnosis and control in Lebanon, a fragile setting

Background: Non-communicable diseases (NCD) present an increasing global health challenge, particularly for settings affected by fragility where access to care may be disrupted, and where high-quality continuous care delivery is difficult to achieve. This study documents the complex dynamics of NCD prevention and management in the fragile setting of rural Beqaa, Lebanon. Methods: Participatory system dynamics methods were used, including 30 semi-structured interviews and three Group Model Building (GMB) workshops. Participants included health care providers offering NCD care, and Lebanese host- and Syrian refugees community members affected by NCDs. Results: Participants across all groups articulated a shared complex understanding of both the structural and direct determinants behind NCD onset. Lebanese and Syrian community members further identified several barriers to health seeking, including restrictions in health coverage, limited availability of services in the Beqaa and perceptions of poor-quality care. Health providers and community members described a health system overtly focused on disease control and overwhelmed by delivery of care to people living with NCD across both communities. Conclusion: Participants across all groups agreed on the need for health promotion and primary prevention activities and identified priority interventions in these areas. © 2021, The Author(s)

Isocyanate Formation in the Catalytic Reaction of CO + NO on Pd(111): An in Situ Infrared Spectroscopic Study at Elevated Pressures

The catalytic conversion of environmentally hazardous pollutants in automobile exhausts is one of the most thoroughly studied problems in heterogeneous catalysis. Three-way catalysts (TWC) are used to remove the major pollutants in the exhaust gases by the simultaneous reduction of NOx and the oxidation of CO and unburned hydrocarbons. Recently, Pd-based catalysts have been considered as an alternative to the more commonly used Pt/Rh-based catalysts.1,2 In this study vibrational spectroscopy is used to examine the in situ adsorption of CO + NO to form CO2, N2O and N2 on a Pd(111) model catalyst under high-pressure conditions. We employ polarization-modulation infrared reflection absorption spectroscopy (PM-IRAS),3-5 an adaption of the well-known IRAS technique. The surface sensitivity of PM-IRAS relies on the fact that IR absorption by an adsorbed species on a metal surface shows a strong dependence on the polarization of the incoming IR beam

A p62-dependent rheostat dictates micronuclei catastrophe and chromosome rearrangements

Chromosomal instability (CIN) generates micronuclei-aberrant extranuclear structures that catalyze the acquisition of complex chromosomal rearrangements present in cancer. Micronuclei are characterized by persistent DNA damage and catastrophic nuclear envelope collapse, which exposes DNA to the cytoplasm. We found that the autophagic receptor p62/SQSTM1 modulates micronuclear stability, influencing chromosome fragmentation and rearrangements. Mechanistically, proximity of micronuclei to mitochondria led to oxidation-driven homo-oligomerization of p62, limiting endosomal sorting complex required for transport (ESCRT)-dependent micronuclear envelope repair by triggering autophagic degradation. We also found that p62 levels correlate with increased chromothripsis across human cancer cell lines and with increased CIN in colorectal tumors. Thus, p62 acts as a regulator of micronuclei and may serve as a prognostic marker for tumors with high CIN

Rhodium Nanoparticle Shape Dependence in the Reduction of NO by CO

The shape dependence of the catalytic reduction of nitric oxide by carbon monoxide on rhodium nanopolyhedra and nanocubes was studied from 230 to 270 degrees C. The nanocubes are found to exhibit higher turnover frequency and lower activation energy than the nanopolyhedra. These trends are compared to previous studies on Rh single crystals.Chemistry, PhysicalSCI(E)EI21ARTICLE3-4317-32213