Effective optimization of atomic decoration in giant and superstructurally ordered crystals with machine learning.

Crystals with complicated geometry are often observed with mixed chemical occupancy among Wyckoff sites, presenting a unique challenge for accurate atomic modeling. Similar systems possessing exact occupancy on all the sites can exhibit superstructural ordering, dramatically inflating the unit cell size. In this work, a crystal graph convolutional neural network (CGCNN) is used to predict optimal atomic decorations on fixed crystalline geometries. This is achieved with a site permutation search (SPS) optimization algorithm based on Monte Carlo moves combined with simulated annealing and basin-hopping techniques. Our approach relies on the evidence that, for a given chemical composition, a CGCNN estimates the correct energetic ordering of different atomic decorations, as predicted by electronic structure calculations. This provides a suitable energy landscape that can be optimized according to site occupation, allowing the prediction of chemical decoration in crystals exhibiting mixed or disordered occupancy, or superstructural ordering. Verification of the procedure is carried out on several known compounds, including the superstructurally ordered clathrate compound Rb8Ga27Sb16 and vacancy-ordered perovskite Cs2SnI6, neither of which was previously seen during the neural network training. In addition, the critical temperature of an order-disorder phase transition in solid solution CuZn is probed with our SPS routines by sampling site configuration trajectories in the canonical ensemble. This strategy provides an accurate method for determining favorable decoration in complex crystals and analyzing site occupation at unprecedented speed and scale.

An experimental and computational view of the photoionization of diol-water clusters.

In the interstellar medium, diols and other prebiotic molecules adsorb onto icy mantles surrounding dust grains. Water in the ice may affect the reactivity and photoionization of these diols. Ethylene glycol (EG), 1,2-propylene glycol, and 1,3-propylene glycol clusters with water clusters were used as a proxy to study these interactions. The diol-water clusters were generated in a continuous supersonic molecular beam, photoionized by synchrotron-based vacuum ultraviolet light from the Advanced Light Source, and subsequently detected by reflectron time-of-flight mass spectrometry. The appearance energies for the detected clusters were determined from the mass spectra, collected at increasing photon energy. Clusters of both diol fragments and unfragmented diols with water were detected. The lowest energy geometry optimized conformers for the observed EG-water clusters and EG fragment-water clusters have been visualized using density functional theory (DFT), providing insight into hydrogen bonding networks and how these affect fragmentation and appearance energy. As the number of water molecules clustered around EG fragments (m/z 31 and 32) increased, the appearance energy for the cluster decreased, indicating a stabilization by water. This trend was supported by DFT calculations. Fragment clusters from 1,2-propylene glycol exhibited a similar trend, but with a smaller energy decrease, and no trend was observed from 1,3-propylene glycol. We discuss and suggest that the reactivity and photoionization of diols in the presence of water depend on the size of the diol, the location of the hydroxyl group, and the number of waters clustered around the diol.

New Trick for an Old Dog: From Prediction to Properties of "Hidden Clathrates" Ba2Zn5As6 and Ba2Zn5Sb6.

The zinc-antimony phase space has been heavily investigated due to the structural complexity and abundance of high-performing thermoelectric materials. Consequentially, the desire to use zinc and antimony as framework elements to encage rattling cations and achieve phonon-glass-electron-crystal-type properties has remained an enticing goal with only two alkali metal clathrates to date, Cs8Zn18Sb28 and K58Zn122Sb207. Guided by Zintl electron-counting predictions, we explored the Ba-Zn-Pn (Pn = As, Sb) phase space proximal to the expected composition of the type-I clathrate. In situ powder X-ray diffraction studies revealed two "hidden" compounds which can only be synthesized in a narrow temperature range. The ex situ synthesis and crystal growth unveiled that instead of type-I clathrates, compositionally close but structurally different new clathrate-like compounds formed, Ba2Zn5As6 and Ba2Zn5Sb6. These materials crystallize in a unique structure, in the orthorhombic space group Pmna with the Wyckoff sequence i2h6gfe. Single-phase synthesis enabled the exploration of their transport properties. Rattling of the Ba cations in oversized cages manifested low thermal conductivity, which, coupled with the high Seebeck coefficients observed, are prerequisites for a promising thermoelectric material. Potential for further optimization of the thermoelectric performance by aliovalent doping was computationally analyzed.

C reactive protein utilisation, a biomarker for early COVID-19 treatment, improves lenzilumab efficacy: results from the randomised phase 3 'LIVE-AIR' trial.

OBJECTIVE: COVID-19 severity is correlated with granulocyte macrophage colony-stimulating factor (GM-CSF) and C reactive protein (CRP) levels. In the phase three LIVE-AIR trial, lenzilumab an anti-GM-CSF monoclonal antibody, improved the likelihood of survival without ventilation (SWOV) in COVID-19, with the greatest effect in participants having baseline CRP below a median of 79 mg/L. Herein, the utility of baseline CRP to guide lenzilumab treatment was assessed. DESIGN: A subanalysis of the randomised, blinded, controlled, LIVE-AIR trial in which lenzilumab or placebo was administered on day 0 and participants were followed through Day 28. PARTICIPANTS: Hospitalised COVID-19 participants (N=520) with SpO2 ≤94% on room air or requiring supplemental oxygen but not invasive mechanical ventilation. INTERVENTIONS: Lenzilumab (1800 mg; three divided doses, q8h, within 24 hours) or placebo infusion alongside corticosteroid and remdesivir treatments. MAIN OUTCOME MEASURES: The primary endpoint was the time-to-event analysis difference in SWOV through day 28 between lenzilumab and placebo treatments, stratified by baseline CRP. RESULTS: SWOV was achieved in 152 (90%; 95% CI 85 to 94) lenzilumab and 144 (79%; 72 to 84) placebo-treated participants with baseline CRP <150 mg/L (HR: 2.54; 95% CI 1.46 to 4.41; p=0.0009) but not with CRP ≥150 mg/L (HR: 1.04; 95% CI 0.51 to 2.14; p=0.9058). A statistically significant interaction between CRP and lenzilumab treatment was observed (p=0.044). Grade ≥3 adverse events with lenzilumab were comparable to placebo in both CRP strata. No treatment-emergent serious adverse events were attributed to lenzilumab. CONCLUSION: Hospitalised hypoxemic patients with COVID-19 with baseline CRP <150 mg/L derived the greatest clinical benefit from treatment with lenzilumab. TRIAL REGISTRATION NUMBER: NCT04351152; ClinicalTrials.gov.

Quantum computation of silicon electronic band structure.

Development of quantum architectures during the last decade has inspired hybrid classical-quantum algorithms in physics and quantum chemistry that promise simulations of fermionic systems beyond the capability of modern classical computers, even before the era of quantum computing fully arrives. Strong research efforts have been recently made to obtain minimal depth quantum circuits which could accurately represent chemical systems. Here, we show that unprecedented methods used in quantum chemistry, designed to simulate molecules on quantum processors, can be extended to calculate properties of periodic solids. In particular, we present minimal depth circuits implementing the variational quantum eigensolver algorithm and successfully use it to compute the band structure of silicon on a quantum machine for the first time. We are convinced that the presented quantum experiments performed on cloud-based platforms will stimulate more intense studies towards scalable electronic structure computation of advanced quantum materials.

ABa6Cu31Te22 (A = K, Rb, Cs) Featuring Polyanionic Copper-Telluride Frameworks with Ultralow Thermal Conductivity.

Three polyanionic tellurides, ABa6Cu31Te22 (A = K, Rb, Cs), were synthesized in salt flux. The isostructural tellurides crystallize in a new structure type, in the cubic Pa3 space group with a Wyckoff sequence of d10c2b1 and large unit cell volumes of over 5500 Å3. The structures feature a framework of [CuTe4] tetrahedra and [CuTe3] trigonal pyramids with disorder in the Cu sites. The polyanionic frameworks have large square antiprism and cuboctahedral voids where Ba and alkali metal cations are situated, forming [BaTe8] and [ATe12], respectively. The overall compositions are close to being charge balanced. The large [ATe12] cuboctahedra allowed for significant anisotropic displacement of the A cations, as observed from both single crystal X-ray diffraction and heat capacity studies. Alkali cations rattling together with Cu atom displacement and disorder leads to the dispersion of phonons, thus softening the lattice and subsequently reducing the thermal conductivity. Evaluations of the electronic band structure revealed the occurrence of a narrow bandgap together with the presence of a flat band near the valence band maximum, giving rise to the high thermopower. The Cs and Rb analogues show a slope change in the temperature dependence of electrical resistivity around room temperature, which is typical for semimetals or degenerate semiconductors. For the as-synthesized and unoptimized materials, high values of the thermoelectric figure-of-merit of ∼0.2 were observed at 623 K.

Earlier diagnosis and earlier treatment of COPD in primary care.

Chronic obstructive pulmonary disease (COPD) is a progressive disease that begins many years before a diagnosis is usually made. The need for an early and confirmed diagnosis of COPD is increasingly appreciated by primary care physicians in whose hands the ability to make improvements in early diagnosis largely rests. Case-finding of patients with symptoms of lifestyle limitation is probably the most practical way to achieve early diagnosis. Evidence suggests a burden of early COPD on afflicted people and their families. Early encouragement of smoking cessation, in conjunction with management of symptoms and treating activity limitation and exacerbations by appropriate non-pharmacologic and pharmacologic management at the earliest possible stage, could positively affect the impact and progression of the disease.

A systematic variational approach to band theory in a quantum computer.

Quantum computers promise to revolutionize our ability to simulate molecules, and cloud-based hardware is becoming increasingly accessible to a wide body of researchers. Algorithms such as Quantum Phase Estimation and the Variational Quantum Eigensolver are being actively developed and demonstrated in small systems. However, extremely limited qubit count and low fidelity seriously limit useful applications, especially in the crystalline phase, where compact orbital bases are difficult to develop. To address this difficulty, we present a hybrid quantum-classical algorithm to solve the band structure of any periodic system described by an adequate tight-binding model. We showcase our algorithm by computing the band structure of a simple-cubic crystal with one s and three p orbitals per site (a simple model for polonium) using simulators with increasingly realistic levels of noise and culminating with calculations on IBM quantum computers. Our results show that the algorithm is reliable in a low-noise device, functional with low precision on present-day noisy quantum computers, and displays a complexity that scales as Ω(M 3) with the number M of tight-binding orbitals per unit-cell, similarly to its classical counterparts. Our simulations offer a new insight into the "quantum" mindset and demonstrate how the algorithms under active development today can be optimized in special cases, such as band structure calculations.

Internet Health Behaviors of Patients with Chronic Obstructive Pulmonary Disease and Assessment of Two Disease Websites.

Background: Little is known about patients' use of the internet to search for information about chronic obstructive pulmonary disease (COPD) and their perspectives on disease content on websites. Objectives: To determine the interests and behavior of patients with COPD who search the internet for disease information and to assess their perspectives about 2 COPD educational websites. Methods: Individuals with COPD who had registered for a consumer panel were invited electronically to participate in a survey which included general use of the internet, online health behaviors about COPD, and assessment of 2 COPD educational websites. Results: A total of 445 respondents completed the survey in 23 ± 12 minutes (72% response rate). A total of 95% reported that physicians were the primary source of information about COPD followed by internet searches about the disease (76%). The 3 major information priorities were "symptom control" (82%), "how COPD is affecting my body" (60%), and "treatments that might work better for me" (59%). Overall ratings (range, 1 - 10) were 7.4 ± 1.5 for the American Lung Association and 6.8 ±1.8 for the COPD Foundation websites. Ratings by respondents were higher for all 5 impression attributes and for 8 of 9 content attributes on the American Lung Association website compared with the COPD Foundation website. Conclusions: This report describes, for the first time, information priorities of patients with COPD about their disease and their assessment of 2 educational websites. Our survey results can be used by health care professionals to recommend online resources to their patients.

A perspective on web-based information for patients with chronic lung disease.

Although the majority of patients with a chronic disease obtain information about their condition from a health care professional, medical appointments may not allow sufficient time for educating patients and addressing questions. Internet resources can fill educational gaps and promote knowledge transformation. In a 2010 Pew Research Center report, the presence of a chronic disease increased the likelihood that a person would search online for health information. To provide the best medical care, it is important that health care providers are knowledgeable about medical information on the internet. This Perspective summarizes the major websites that present patient-focused medical information about three common lung diseases-asthma, chronic obstructive pulmonary disease, and idiopathic pulmonary fibrosis. These websites can be categorized as those sponsored by pharmaceutical companies, for-profit and nonprofit professional organizations, the National Health Lung and Blood Institute, health care organizations, and patient support groups. In addition, three novel websites about chronic obstructive pulmonary disease are described with the ostensible goal of providing user-friendly information with a focus on individual patients. One was developed as a public university-private partnership, whereas the other two were developed by individuals with interest and experience in respiratory diseases-a respiratory therapist and a pulmonologist. The websites described in this perspective, along with numerous other sources, provide medical information for patients with respiratory diseases that offer a marketplace for viewing. Health care professionals can recommend specific websites to patients to complement discussions during the office visit.

Biochemical properties, pharmacokinetics and pharmacological response of tiotropium in chronic obstructive pulmonary disease patients.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a progressive disease with increasing incidence and mortality. Tiotropium is an inhaled long-acting anti-cholinergic for the maintenance treatment of COPD. OBJECTIVE: To review biochemical and pharmacokinetic data on tiotropium and discuss in the context of tiotropium's efficacy and safety in COPD. METHODS: Review of previously done pharmacokinetic studies performed by the manufacturer of tiotropium. Data obtained through peer-reviewed publications and regulatory websites. RESULTS/CONCLUSIONS: The long duration of action with tiotropium is owing to prolonged, competitive binding to M(3) muscarinic receptors. Tiotropium is poorly absorbed following inhalation, which largely limits side effects. Metabolism of absorbed drug is minimal and excretion is largely through the kidneys. Tiotropium is efficacious and well tolerated by patients with COPD.