Three-Dimensional Electronic Structure of the Type-II Weyl Semimetal WTe_{2}.

By combining bulk sensitive soft-x-ray angular-resolved photoemission spectroscopy and first-principles calculations we explored the bulk electron states of WTe_{2}, a candidate type-II Weyl semimetal featuring a large nonsaturating magnetoresistance. Despite the layered geometry suggesting a two-dimensional electronic structure, we directly observe a three-dimensional electronic dispersion. We report a band dispersion in the reciprocal direction perpendicular to the layers, implying that electrons can also travel coherently when crossing from one layer to the other. The measured Fermi surface is characterized by two well-separated electron and hole pockets at either side of the Γ point, differently from previous more surface sensitive angle-resolved photoemission spectroscopy experiments that additionally found a pronounced quasiparticle weight at the zone center. Moreover, we observe a significant sensitivity of the bulk electronic structure of WTe_{2} around the Fermi level to electronic correlations and renormalizations due to self-energy effects, previously neglected in first-principles descriptions.

Bayesian Optimization of Low-Temperature Nonthermal Plasma Jet Sintering of Nanoinks.

In response to the escalating demand for flexible devices in applications such as wearables, sensors, and touch panels, there is a need for innovative fabrication approaches for devices made from nanomaterial-based inks. Subsequent to ink deposition, a pivotal stage in device manufacturing typically involves high-temperature sintering, posing challenges for heat-sensitive substrates. Nonthermal plasma jet sintering utilizing an atmospheric pressure dielectric barrier discharge (DBD) plasma jet enables sintering at room temperature and standard pressure, facilitating the sintering of printed nanoparticle films without compromising substrate or film surface integrity. However, determining optimal plasma jet sintering conditions can be challenging due to multiple processing variables with intricate interrelationships. This work employed Bayesian optimization (BO) and machine learning (ML) to identify optimal values for seven primary plasma jet sintering variables. Optimization yielded a 99.2% increase in the measured electrical conductivity for plasma jet-sintered indium tin oxide (ITO) films after five rounds of experiments. Moreover, the optimal sintering conditions achieved an electrical conductivity that was 81.4% of conventional furnace sintering at 300 °C, but was three times faster and with a peak substrate temperature below 47 °C. This result demonstrates the prospect of applying BO to optimize processing techniques for emerging low-temperature requirements.

Prevalence of NDM-1 carbapenemase in patients with diarrhoea in Pakistan and evaluation of two chromogenic culture media.

AIMS: To evaluate two chromogenic media, Brilliance CRE and chromID CARBA, with stool samples referred to the Public Health Laboratories Division of the National Institute of Health in Islamabad, and assess the prevalence of carbapenemase-producing Enterobacteriaceae (CPE) in this population. METHODS AND RESULTS: One hundred and fifty-two stool samples from patients with diarrhoea were referred to the Microbiology Department and were investigated for the presence of CPE using two chromogenic culture media, Brilliance CRE and chromID CARBA. Thirteen patients (8·6%) were found to be colonized with CPE and all produced NDM-1 carbapenemase. Twelve of these patients (92%) were found to be colonized by culture on chromID CARBA compared with seven (54%) using Brilliance CRE. CONCLUSIONS: If only coloured colonies were considered as presumptive CPE, the sensitivity, specificity and positive predictive value were 54, 23 and 6% for Brilliance CRE and 85, 85 and 36% for chromID CARBA, respectively. SIGNIFICANCE AND IMPACT OF THE STUDY: We conclude that Enterobacteriaceae that produce NDM-1 carbapenemase can be found in patients from all major provinces of Pakistan and that chromID CARBA was the most effective of the two chromogenic media in this setting.

Biometric and morphologic studies of the female reproductive organs of the African giant rat (Cricetomys gambianus: Waterhouse).

Different segments of the reproductive tract of 100 adult, non-pregnant, female African giant rats (AGR) were carefully examined, weighed, and measured. The ovaries were observed to be small, pinkish, and kidney-shaped. The uterus of the AGR was found to be uterus duplex. The live weight of the AGR was 999.7 ± 16.86 g. The weight, length, and width of the ovary were 0.095 ± 0.003 g, 0.750 ± 0.01 cm, and 0.01± 0.02 cm, respectively. The length of the oviduct, uterus, and vagina/vestibule were 4.44 ± 0.06 cm, 4.877 ± 0.11 cm, and 4.345 ± 0.07 cm, respectively. The weight and length of the entire tubular organs were 3.171 ± 0.01 g and 13.559 ± 0.18 cm with corresponding range values of 1.61-7.10 g and 7.80-17.40 cm, respectively.

Giant intrinsic spin Hall effect in W3Ta and other A15 superconductors.

The spin Hall effect (SHE) is the conversion of charge current to spin current, and nonmagnetic metals with large SHEs are extremely sought after for spintronic applications, but their rarity has stifled widespread use. Here, we predict and explain the large intrinsic SHE in ß-W and the A15 family of superconductors: W3Ta, Ta3Sb, and Cr3Ir having spin Hall conductivities (SHCs) of -2250, -1400, and 1210 ℏ e ( S / cm ) , respectively. Combining concepts from topological physics with the dependence of the SHE on the spin Berry curvature (SBC) of the electronic bands, we propose a simple strategy to rapidly search for materials with large intrinsic SHEs based on the following ideas: High symmetry combined with heavy atoms gives rise to multiple Dirac-like crossings in the electronic structure; without sufficient symmetry protection, these crossings gap due to spin-orbit coupling; and gapped crossings create large SBC.

Author Correction: Layer-dependent quantum cooperation of electron and hole states in the anomalous semimetal WTe2.

This Article contains an error in the spelling of the author A. Yazdani, which is incorrectly given as A. Yadzani. The error has not been fixed in the original PDF and HTML versions of the Article.

Layer-dependent quantum cooperation of electron and hole states in the anomalous semimetal WTe2.

The behaviour of electrons and holes in a crystal lattice is a fundamental quantum phenomenon, accounting for a rich variety of material properties. Boosted by the remarkable electronic and physical properties of two-dimensional materials such as graphene and topological insulators, transition metal dichalcogenides have recently received renewed attention. In this context, the anomalous bulk properties of semimetallic WTe2 have attracted considerable interest. Here we report angle- and spin-resolved photoemission spectroscopy of WTe2 single crystals, through which we disentangle the role of W and Te atoms in the formation of the band structure and identify the interplay of charge, spin and orbital degrees of freedom. Supported by first-principles calculations and high-resolution surface topography, we reveal the existence of a layer-dependent behaviour. The balance of electron and hole states is found only when considering at least three Te-W-Te layers, showing that the behaviour of WTe2 is not strictly two dimensional.

Chimeric 7E3 Fab (ReoPro) decreases detectable CD11b on neutrophils from patients undergoing coronary angioplasty.

OBJECTIVES: The purpose of this study was to monitor the effects of chimeric 7E3 Fab (ReoPro) on leukocyte and platelet activation and interaction during coronary angioplasty. BACKGROUND: Increased expression of CD11b on monocytes and neutrophils promotes their adhesion to endothelial cells, extracellular matrix and smooth muscle cells. Thrombin-activated platelets adhere via P-selectin to monocytes and neutrophils. These cell interactions may affect the outcome of coronary angioplasty. METHODS: During coronary angioplasty, venous blood was obtained for flow cytometric detection of leukocyte CD11b; platelet CD41a, CD61a and CD62P; the percentage of leukocytes with adherent platelets and the intensity of bound platelet fluorescence. RESULTS: Leukocyte CD11b expression increased after angioplasty in control patients (neutrophils 171+/-25 to 255+/-31 mean fluorescence intensity [MFI, mean+/-SEM], n=25, p < 0.0001; monocytes 200+/-40 to 248+/-36 MFI, n=17, p < 0.05) and decreased in the patients selected to receive chimeric 7E3 Fab (neutrophils 146+/-30 to 82+/-22 MFI, n=25, p < 0.0001; monocytes 256+/- 53 to 160+/-38 MFI, n= 17, p < 0.05). Neutrophil CD11b decreased after in vitro incubation of whole blood with chimeric 7E3 Fab (n=5, p=0.01), but fMLP-induced increases in CD11b were not prevented. The CD11b expression was unchanged and increased with fMLP stimulation after in vitro incubation of isolated neutrophils with chimeric 7E3 Fab. Direct-labeled chimeric 7E3 Fab was not detected bound to neutrophils in whole blood or isolated cells using flow cytometric techniques. Adhesion of isolated neutrophils to protein-coated glass was not prevented by in vitro incubation with chimeric 7E3 Fab. Platelet activation increased after angioplasty in control patients (CD62P 8.9+/-0.8 to 12.3+/-1.2 MFI, n=25, p < 0.05; CD41a 382+/-25 to 454+/-26 MFI, n=25, p < 0.05, CD61a 436+/-52 to 529+/-58 MFI, n=11, p < 0.05); it did not increase in the patients selected to receive chimeric 7E3 Fab (CD62P 13.2+/-1.0 to 9.0+/-0.9 MFI, n=25, p < 0.05; CD61a 398+/-32 to 410+/-38 MFI, n=7, p=NS). Leukocytes with adherent platelets tended to increase in the control group of patients and decrease after the procedure in patients selected to receive chimeric 7E3 Fab; individual and procedure-related variability were marked. CONCLUSIONS: Despite standard aspirin and heparin therapy, leukocyte and platelet activation with platelet adherence to leukocytes occurs after coronary angioplasty. Although chimeric 7E3 Fab does not bind to leukocytes directly, it influences CD11b expression in whole blood. Modulation of platelet and leukocyte activation and interaction by chimeric 7E3 Fab may contribute to an improved outcome after coronary angioplasty.

Antithrombotic therapy in patients with acute coronary syndromes.

The potential armamentarium of agents used in the treatment of acute coronary syndromes continues to expand, including such well-tested agents as aspirin, unfractionated heparin, and earlier-generation fibrinolytic agents, and newer agents such as low-molecular-weight heparins, direct thrombin inhibitors, thienopyridines, platelet glycoprotein IIb/IIIa receptor inhibitors, and bolus-administration fibrinolytic agents. Older and newer antithrombotic agents have undergone and continue to undergo intensive clinical investigation in patients with the clinical spectrum of acute coronary syndromes, which includes unstable angina, non-Q-wave (non-ST-segment elevation) myocardial infarction, and ST-segment elevation myocardial infarction. These studies, often conducted on an international scope and involving thousands of patients, provide data allowing practitioners to optimize the care of patients with acute coronary syndromes. In this article, studies of these established and newer agents in the treatment of patients with acute coronary syndromes are reviewed critically and summarized. Recommendations regarding use of antithrombotic agents in patients with acute coronary syndromes are then given.

Quantum criticality in a uniaxial organic ferroelectric.

Tris-sarcosine calcium chloride (TSCC) is a highly uniaxial ferroelectric with a Curie temperature of approximately 130 K. By suppressing ferroelectricity with bromine substitution on the chlorine sites, pure single crystals were tuned through a ferroelectric quantum phase transition. The resulting quantum critical regime was investigated in detail and was found to persist up to temperatures of at least 30-40 K. The nature of long-range dipole interactions in uniaxial materials, which lead to non-analytical terms in the free-energy expansion in the polarization, predict a dielectric susceptibility varying as 1/T(3)close to the quantum critical point. Rather than this, we find that the dielectric susceptibility varies as 1/T(2) as expected and observed in better known multi-axial systems. We explain this result by identifying the ultra-weak nature of the dipole moments in the TSCC family of crystals. Interestingly, we observe a shallow minimum in the inverse dielectric function at low temperatures close to the quantum critical point in paraelectric samples that may be attributed to the coupling of quantum polarization and strain fields. Finally, we present results of the heat capacity and electro-caloric effect and explain how the time dependence of the polarization in ferroelectrics and paraelectrics should be considered when making quantitative estimates of temperature changes induced by applied electric fields.