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Abstract Discrete time-translational symmetry in a periodically driven many-body system can be spontaneously broken to form a discrete time crystal, an exotic new phase of matter. We present observations characteristic of discrete time crystalline order in a driven system of paramagnetic P-donor impurities in isotopically enriched 28Si cooled below 10 K. The observations exhibit a stable subharmonic peak at half the drive frequency which remains pinned even in the presence of pulse error, a signature of discrete time crystalline order. This signal has a finite lifetime of ∼100 Floquet periods, but this effect is long-lived relative to coherent spin–spin interaction timescales, lasting ∼104 times longer. We present simulations of the system based on the paradigmatic central spin model and show good agreement with experiment. We investigate the role of dissipation and interactions within this model, and show that both are capable of giving rise to discrete time crystal-like behaviour.

Aims Treatment of patients with heart failure (HF) relies on measurement of LVEF. However, the extent to which EF is recorded varies markedly. We sought to characterize the patient group that is missing a measure of EF, and to explore the association between missing EF and outcome. Methods and results Individual data on 30 445 patients from 28 observational studies in the Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) project were used to compare the prevalence of co-morbidities and outcome across three groups of HF patients: those with missing EF (HF-mEF), reduced EF (HF-REF), and preserved EF (HF-PEF). A total of 29% had HF-mEF, 52% HF-REF, and 19% HF-PEF. Compared with patients in whom EF was known, patients with HF-mEF were older, had a greater prevalence of COPD and previous stroke, and were smokers. Patients with HF-mEF were less likely to receive evidence-based treatment than those with HF-REF. Adjusted mortality in HF-mEF was similar to that in HF-REF and greater than that in HF-PEF at 3 years [HF-REF, hazard ratio (HR) 1.03, 95% confidence interval (CI) 0.95–1.12); HF-PEF, HR 0.78, 95% CI 0.71–0.86]. Conclusion Missing EF is common. The short- and long-term outcome of patients with HF-mEF is poor and they exhibit different co-morbidity profiles and treatment patterns compared with patients with known EF. HF patients with missing EF represent a high risk group.

We hypothesize that phytoplankton have the sequential nutrient uptake strategy to maintain nutrient stoichiometry and high primary productivity in the water column. According to this hypothesis, phytoplankton take up the most limiting nutrient first until depletion, continue to draw down non-limiting nutrients and then take up the most limiting nutrient rapidly when it is available. These processes would result in the variation of ambient nutrient ratios in the water column around the Redfield ratio. We used high-resolution continuous vertical profiles of nutrients, nutrient ratios and on-board ship incubation experiments to test this hypothesis in the Strait of Georgia. At the surface in summer, ambient NO3− was depleted with excess PO43− and SiO4− remaining, and as a result, both N : P and N : Si ratios were low. The two ratios increased to about 10 : 1 and 0. 45 : 1, respectively, at 20 m. Time series of vertical profiles showed that the leftover PO43− continued to be removed, resulting in additional phosphorus storage by phytoplankton. The N : P ratios at the nutricline in vertical profiles responded differently to mixing events. Field incubation of seawater samples also demonstrated the sequential uptake of NO3− (the most limiting nutrient) and then PO43− and SiO4− (the non-limiting nutrients). This sequential uptake strategy allows phytoplankton to acquire additional cellular phosphorus and silicon when they are available and wait for nitrogen to become available through frequent mixing of NO3− (or pulsed regenerated NH4). Thus, phytoplankton are able to maintain high productivity and balance nutrient stoichiometry by taking advantage of vigorous mixing regimes with the capacity of the stoichiometric plasticity. To our knowledge, this is the first study to show the in situ dynamics of continuous vertical profiles of N : P and N : Si ratios, which can provide insight into the in situ dynamics of nutrient stoichiometry in the water column and the inference of the transient status of phytoplankton nutrient stoichiometry in the coastal ocean.

Abstract In this work, the beneficial effect of carbocation scavenger additives on hardwood pretreatment was revealed by significantly improved biomass saccharification: cellulose hydrolysis yield was increased by over 15% after steam pretreatment of poplar, while that was enhanced by more than 48% after dilute acid pretreatment. Besides, the relative contributions of lignin towards enzyme binding and physical barrier effect for proposed mechanisms were quantified. Results indicated that the addition of carbocation scavenger, 2-naphthol-7-sulfonate, resulted in acid groups incorporation of 62.36 mmol/kg to lignin, which mitigated enzyme non-productive binding. Moreover, enlarged biomass porosity and reduced surface lignin coverage were detected through BET and XPS analysis, respectively, which mostly related to the diminished physical barrier effect of lignin. As a result, the lignin inhibitions were significantly suppressed through the addition of carbocation scavenger, giving rise to significantly improved enzymatic hydrolysis of hardwood.

Abstract Mo improved Ni/Al2O3 catalysts were prepared and characterized, which demonstrated good catalytic performance for thioetherification process of FCC gasoline. The physico-chemical properties of the Ni/Al2O3 catalysts with different amounts of Mo were characterized by physical techniques and were correlated with their catalytic performance. Experimental results showed that bimetal (Mo and Ni) based catalysts displayed superior catalytic performance than mono-metal (Ni) based catalysts. Addition of Mo to Ni catalysts could inhibit the formation of NiAl2O4 crystallites and facilitate the formation of active precursor NiMoO4, contributing to the formation of more active sites during the presulfidation process. The micro-morphology of active species was restructured and the needle-stacks of Ni-Mo-S were observed on the Mo improved catalysts. These structures and properties had important influence on the thioetherification. By optimizing the Mo/Ni atomic ratio, the catalysts with a Mo/Ni atomic ratio of 0.3 had suitable micro-morphologies and properties, exhibiting the best catalytic performance and selectivity for thioetherification.

Background Aortic stenosis (AS) is a common valvular abnormality and transcatheter aortic valve implantation (TAVI) is being increasingly used to treat patients considered too high risk for conventional surgery. We aimed to assess the prevalence of comorbid conditions in patients undergoing TAVI using the Charlson Comorbidity Index (CCI) and to assess their impact on clinical and procedural outcomes. Methods We analysed 158 patients who underwent a TAVI at our institution between June 2009 and September 2015 to define their co-morbid burden as measured with CCI, and study its impact on procedural characteristics and mortality at 30 days. Results One hundred fifty-eight (158) patients with a mean age of 82 ± 8 years and a mean CCI score of 2.67 underwent a TAVI. Only 12/158 patients had a CCI of 0. The commonest cardiovascular comorbidities were previous myocardial infarction (24%), congestive heart failure (15%) and diabetes mellitus (23%) whilst the commonest non-cardiovascular comorbidities were renal disease (46%) and chronic obstructive pulmonary disease (COPD) (29%). After multivariable adjustment, CCI was not independently associated with adverse clinical outcomes. The addition of CCI to scoring systems such as Logistic EuroScore (LES) and Society of Thoracic Surgeons (STS) risk models improved the area under the curve from 0.75 (95%CI: 0.44–1.00) and 0.83 (95%CI: 0.64–1.00) to 0.78 (95%CI: 0.53–1.00) and 0.89 (95%CI: 0.78–1.00) respectively. Conclusions The burden of comorbid conditions in patients undergoing TAVI is significant. The CCI score was not independently associated with a higher risk of death but can be useful in addition to LES and STS risk models in informing decision making on the selection of patients for TAVI.

A comprehensive quality assessment of the ozone products from 18 limb-viewing satellite instruments is provided by means of a detailed intercomparison. The ozone climatologies in form of monthly zonal mean time series covering the upper troposphere to lower mesosphere are obtained from LIMS, SAGE I/II/III, UARS-MLS, HALOE, POAM II/III, SMR, OSIRIS, MIPAS, GOMOS, SCIAMACHY, ACE-FTS, ACE-MAESTRO, Aura-MLS, HIRDLS, and SMILES within 1978–2010. The intercomparisons focus on mean biases of annual zonal mean fields, interannual variability, and seasonal cycles. Additionally, the physical consistency of the data is tested through diagnostics of the quasi-biennial oscillation and Antarctic ozone hole. The comprehensive evaluations reveal that the uncertainty in our knowledge of the atmospheric ozone mean state is smallest in the tropical and midlatitude middle stratosphere with a 1σ multi-instrument spread of less than ±5%. While the overall agreement among the climatological data sets is very good for large parts of the stratosphere, individual discrepancies have been identified, including unrealistic month-to-month fluctuations, large biases in particular atmospheric regions, or inconsistencies in the seasonal cycle. Notable differences between the data sets exist in the tropical lower stratosphere (with a spread of ±30%) and at high latitudes (±15%). In particular, large relative differences are identified in the Antarctic during the time of the ozone hole, with a spread between the monthly zonal mean fields of ±50%. The evaluations provide guidance on what data sets are the most reliable for applications such as studies of ozone variability, model-measurement comparisons, detection of long-term trends, and data-merging activities.

The HIV Research for Prevention (HIVR4P) conference is dedicated to advancing HIV prevention research, responding to a growing consensus that effective and durable prevention will require a combination of approaches as well as unprecedented collaboration among scientists, practitioners, and community workers from different fields and geographic areas. The conference theme in 2018, "From Research to Impact," acknowledged an increasing focus on translation of promising research findings into practical, accessible, and affordable HIV prevention options for those who need them worldwide. HIVR4P 2018 was held in Madrid, Spain, on 21-25 October, with >1,400 participants from 52 countries around the globe, representing all aspects of HIV prevention research and implementation. The program included 137 oral and 610 poster presentations. This article presents a brief summary of highlights from the conference. More detailed information, complete abstracts as well as webcasts and daily Rapporteur summaries may be found on the conference website. Supported by Gilead who provided funding. Gilead has had no input into the content of the materials used at this meeting/conference. No other pharmaceutical company has had input into the content of the materials used at this conference. HIVR4P 2018 was made possible in part by 1 R13 AI136762-01 from the National Institute of Allergy and Infectious Diseases (NIAID). The views expressed in written conference materials or publications and by speakers and moderators do not necessarily reflect the official policies of the Department of Health and Human Services; nor does mention of trade names, commercial practices, or organizations imply endorsement by the U.S. Government. Sí

Being taller is associated with enhanced longevity, and higher education and earnings. We reanalysed 1472 population-based studies, with measurement of height on more than 18.6 million participants to estimate mean height for people born between 1896 and 1996 in 200 countries. The largest gain in adult height over the past century has occurred in South Korean women and Iranian men, who became 20.2 cm (95% credible interval 17.5–22.7) and 16.5 cm (13.3–19.7) taller, respectively. In contrast, there was little change in adult height in some sub-Saharan African countries and in South Asia over the century of analysis. The tallest people over these 100 years are men born in the Netherlands in the last quarter of 20th century, whose average heights surpassed 182.5 cm, and the shortest were women born in Guatemala in 1896 (140.3 cm; 135.8–144.8). The height differential between the tallest and shortest populations was 19-20 cm a century ago, and has remained the same for women and increased for men a century later despite substantial changes in the ranking of countries. http://purl.org/eprint/status/PeerReviewed published version Article

Four diboron BN-heterocycles bearing two BN units have been synthesized via double lithiation/borylation with the aim to examine their thermal and photoelimination properties. In two of the BN-heterocycles, (BN)2-1 and (BN)2-4, the BN units share the central linker unit, while the other two BN-heterocycles (BN)2-2 and (BN)2-3 are isomers with a benzene ring in the middle of the backbone separating the two chelate units. Only compound (BN)2-3 can thermally and photochemically undergo complete double elimination producing green fluorescent (BN)2-3a due to the highly crowded boron centers. (BN)2-2 can partially convert (∼56%) to (BN)2-2a under 350 nm UV irradiation. (BN)2-1 and (BN)2-4 are either inactive or unstable toward photolysis. The molecular structures and electronic properties of these (BN)2-heterocycles have been investigated experimentally as well as computationally using TD-DFT to further elucidate the origin of differences in optical and electronic properties.