A way to identify whether a DFT gap is from right reasons or error cancellations: The case of copper chalcogenides.

Gap opening remains elusive in copper chalcogenides (Cu2X, X = S, Se, and Te), not least because Hubbard + U, hybrid functional, and GW methods have also failed. In this work, we elucidate that their failure originates from a severe underestimation of the 4s-3d orbital splitting of the Cu atom, which leads to a band-order inversion in the presence of an anionic crystal field. As a result, the Fermi energy is pinned due to symmetry, yielding an invariant zero gap.

Evaluating the role of serum uric acid in the risk stratification and therapeutic response of patients with pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD).

Pulmonary arterial hypertension (PAH) is a malignant pulmonary vascular disease that negatively impacts quality of life, exercise capacity, and mortality. This study sought to investigate the relationship between serum uric acid (UA) level and the disease severity and treatment response of patients with PAH and congenital heart disease (PAH-CHD). This study included 225 CHD patients and 40 healthy subjects.

On the bandgap underestimation of delafossite transparent conductive oxides CuMO2 (M = Al, Ga and In): Role of pseudopotentials.

We report a first-principles study on the electronic and optical properties of delafossite CuMO2 (M = Al, Ga and In) using the recently developed hybrid functional pseudopotentials. We obtain trends of the fundamental and optical gaps with increasing M-atomic number, in agreement with experiment. In particular, we reproduce the experimental fundamental gap, optical gap, and Cu 3d energy of CuAlO2 almost perfectly, in contrast to the various calculations that have traditionally focused on valence electrons, which are unable to reproduce these key properties simultaneously.

Liquid Metal-Doped Conductive Hydrogel for Construction of Multifunctional Sensors.

Interest in wearable and stretchable multifunctional sensors has grown rapidly in recent years. The sensing elements must accurately detect external stimuli to expand their applicability as sensors. However, the sensor's self-healing and adhesion to a target object have been major challenges in developing such practical and versatile devices.

Verification and Analysis of Filter Paper-Based Intracellular Delivery of Exogenous Substances.

The intracellular delivery of exogenous substances is an essential technical means in the field of biomedical research, including cell therapy and gene editing. Although many delivery technologies and strategies are present, each technique has its own limitations. The delivery cost is usually a major limiting factor for general laboratories.

Accuracy trade-off between one-electron and excitonic spectra of cuprous halides in first-principles calculations.

Because of the sophisticated error cancellation in the density functional theory (DFT)-based calculations, a theoretically more accurate input would not guarantee a better output. In this work, our first-principles GW plus Bethe-Salpeter equation calculations using pseudopotentials show that cuprous halides (CuCl and CuBr) are such extreme cases for which a better one-electron band is not accompanied with a better exciton binding energy. Moreover, we find that the exchange interaction of Cu core electrons plays a crucial role in their ground-state electronic properties, especially in the energy gap and macroscopic dielectric constant.

Explaining Positional Differences of Performance Profiles for the Elite Female Basketball Players.

The aim of the present study was to explore the differences in technical performances of players considering playing positions by controlling the effect of situational variables in each FIBA female continental basketball competition. Samples of 9,208 observations from 471 games in the America, Africa, Asia, and Europe Championships during 2013-2017 were collected and analyzed by generalized mixed linear modeling. The results showed that Centers from Europe had more 2-point made (ES = 0.

The Regional Differences in Game-Play Styles Considering Playing Position in the FIBA Female Continental Basketball Competitions.

The aim of this study was to identify regional differences based on playing position in terms of the technical performances among FIBA Female Continental Basketball Championships by controlling the influence of situational variables including the game outcome, game type, teams and opponent quality. The samples comprised of 9208 performance records from 471 games in the America, Africa, Asia and Europe Championships during 2013-2017 and were collected and analyzed by generalized mixed linear modeling. Our study highlighted that, although positional differences were clear among different continental championships, it is worth noting that African guards, forwards, and centers made more turnovers (TOV) compared with the corresponding positional players from other continental championships.

Expression of ApoA5 and its function in the right ventricular failing and remodeling secondary to pulmonary hypertension.

Right heart failure and right ventricular (RV) remodeling were the main reason for mortality of pulmonary hypertension (PH) patients. Apolipoprotein AV (ApoA5) is a key regulator of plasma triglyceride and have multifunction in several target organs. We detected decreased ApoA5 in serum of patients with PH and both in serum and RV of monocrotaline-induced PH model.

Spin-Triplet Excitonic Insulator: The Case of Semihydrogenated Graphene.

While various excitonic insulators have been studied in the literature, due to the perceived too-small spin splitting, spin-triplet excitonic insulator is rare. In two-dimensional systems such as a semihydrogenated graphene (known as graphone), however, it is possible, as revealed by first-principles calculations coupled with Bethe-Salpeter equation. The critical temperature, given by an effective Hamiltonian, is 11.

Core-shell MOF@MOF composites for sensitive nonenzymatic glucose sensing in human serum.

The detection of blood glucose level receives much attention, because diabetes has become one of the significant threats to human health worldwide. In this paper, we described a novel core-shell MOF@MOF composite-based electrochemical sensor for nonenzymatic glucose sensing in alkaline media. The core-shell UiO-67@Ni-MOF composites were synthesized by internal extended growth of shell Ni-MOF on the core UiO-67 under polyvinylpyrrolidone (PVP) regulation.

Understanding the origin of bandgap problem in transition and post-transition metal oxides.

Improving electronic structure calculations for practical and technologically important materials has been a never-ending pursue. This is especially true for transition and post-transition metal oxides for which the current first-principles approaches still suffer various drawbacks. Here, we present a hierarchical-hybrid functional approach built on the use of pseudopotentials.

Half-Excitonic Insulator: A Single-Spin Bose-Einstein Condensate.

First-principles calculations reveal an unusual electronic state (dubbed as half excitonic insulator) in monolayer 1T-MX_{2} (M=Co, Ni and X=Cl, Br). Its one spin channel has a many-body ground state due to excitonic instability, while the other is characterized by a conventional band insulator gap. This disparity arises from a competition between the band gap and exciton binding energy, which exhibits a spin dependence due to different orbital occupations.

High-Yield Formation of Graphdiyne Macrocycles through On-Surface Assembling and Coupling Reaction.

Rationally designed halogenated hydrocarbons are widely used building blocks to fabricate covalent-bonded carbon nanostructures on surfaces through a reaction pathway involving generation and dissociation of organometallic intermediates and irreversible covalent bond formation. Here, we provide a comprehensive picture of the on-surface-assisted homocoupling reaction of 1,3-bis(2-bromoethynyl)benzene on Au(111), aiming for the synthesis of graphdiyne nanostructures. Submolecular resolution scanning tunneling microscopy and noncontact atomic force microscopy observations identify the organometallic intermediates and their self-assemblies formed in the dehalogenation process.

Effect of Hartree-Fock pseudopotentials on local density functional theory calculations.

Density functional theory (DFT) can run into serious difficulties with localized states in elements such as transition metals with occupied d states and oxygen. In contrast, including a fraction of the Hartree-Fock exchange can be a better approach for such localized states. Here, we develop Hartree-Fock pseudopotentials to be used alongside DFT for solids.

Unique Transformation from Graphene to Carbide on Re(0001) Induced by Strong Carbon-Metal Interaction.

During graphene growth on various transition metals in the periodic table, metal carbides always emerge to behave as complex intermediates. On VIII metals, metastable carbides usually evolve and then transform into graphene along the phase interfaces, and even no metal carbides can form on IB-IIB metals. In contrast, during graphene growth on group IVB-VIB metals, carbides are usually generated even before the evolution of graphene and stably exist throughout the whole growth process.

Two-dimensional metallic tantalum disulfide as a hydrogen evolution catalyst.

Two-dimensional metallic transition metal dichalcogenides are emerging as prototypes for uncovering fundamental physical phenomena, such as superconductivity and charge-density waves, as well as for engineering-related applications. However, the batch production of such envisioned transition metal dichalcogenides remains challenging, which has hindered the aforementioned explorations. Herein, we fabricate thickness-tunable tantalum disulfide flakes and centimetre-sized ultrathin films on an electrode material of gold foil via a facile chemical vapour deposition route.

Temperature-Triggered Sulfur Vacancy Evolution in Monolayer MoS /Graphene Heterostructures.

The existence of defects in 2D semiconductors has been predicted to generate unique physical properties and markedly influence their electronic and optoelectronic properties. In this work, it is found that the monolayer MoS prepared by chemical vapor deposition is nearly defect-free after annealing under ultrahigh vacuum conditions at ≈400 K, as evidenced by scanning tunneling microscopy observations. However, after thermal annealing process at ≈900 K, the existence of dominant single sulfur vacancies and relatively rare vacancy chains (2S, 3S, and 4S) is convinced in monolayer MoS as-grown on Au foils.

Scaling Universality between Band Gap and Exciton Binding Energy of Two-Dimensional Semiconductors.

Using first-principles   GW Bethe-Salpeter equation calculations and the k·p theory, we unambiguously show that for two-dimensional (2D) semiconductors, there exists a robust linear scaling law between the quasiparticle band gap (E_{g}) and the exciton binding energy (E_{b}), namely, E_{b}≈E_{g}/4, regardless of their lattice configuration, bonding characteristic, as well as the topological property. Such a parameter-free universality is never observed in their three-dimensional counterparts. By deriving a simple expression for the 2D polarizability merely with respect to E_{g}, and adopting the screened hydrogen model for E_{b}, the linear scaling law can be deduced analytically.

Irreparable Defects Produced by the Patching of h-BN Frontiers on Strongly Interacting Re(0001) and Their Electronic Properties.

Clarifying the origin and the electronic properties of defects in materials is crucial since the mechanical, electronic and magnetic properties can be tuned by defects. Herein, we find that, for the growth of h-BN monolayer on Re(0001), the patching frontiers of different domains can be classified into three types, i.e.

General criterion to distinguish between Schottky and Ohmic contacts at the metal/two-dimensional semiconductor interface.

The contact interface plays a crucial role in the performance of various nanoelectronic devices based on two-dimensional (2D) semiconductors. Using first-principles calculations, we investigate the nature of single-layer titanium trisulfide (TiS) and metal contacts as a prototype system. We find that the contacts with Au(111), Ag(111), Al(111) and Cu(111) are of the Schottky type with barriers of 2.

Strong Adlayer-Substrate Interactions "Break" the Patching Growth of h-BN onto Graphene on Re(0001).

Hetero-epitaxial growth of hexagonal boron nitride (h-BN) from the edges of graphene domains or vice versa has been widely observed during synthesis of in-plane heterostructures of h-BN-G on Rh(111), Ir(111), and even Cu foil. We report that on a strongly coupled Re(0001) substrate via a similar two-step sequential growth strategy, h-BN preferably nucleated on the edges of Re(0001) steps rather than on the edges of existing graphene domains. Statistically, one-third of the domain boundaries of graphene and h-BN were patched seamlessly, and the others were characterized by obvious "defect lines" when the total coverage approached a full monolayer.

Selenium-Enriched Nickel Selenide Nanosheets as a Robust Electrocatalyst for Hydrogen Generation.

To address the urgent need for clean and sustainable energy, the rapid development of hydrogen-based technologies has started to revolutionize the use of earth-abundant noble-metal-free catalysts for the hydrogen evolution reaction (HER). Like the active sites of hydrogenases, the cation sites of pyrite-type transition-metal dichalcogenides have been suggested to be active in the HER. Herein, we synthesized electrodes based on a Se-enriched NiSe2 nanosheet array and explored the relationship between the anion sites and the improved hydrogen evolution activity through theoretical and experimental studies.

High Detectivity Graphene-Silicon Heterojunction Photodetector.

A graphene/n-type silicon (n-Si) heterojunction has been demonstrated to exhibit strong rectifying behavior and high photoresponsivity, which can be utilized for the development of high-performance photodetectors. However, graphene/n-Si heterojunction photodetectors reported previously suffer from relatively low specific detectivity due to large dark current. Here, by introducing a thin interfacial oxide layer, the dark current of graphene/n-Si heterojunction has been reduced by two orders of magnitude at zero bias.

Ultra-stable small diameter hybrid transition metal dichalcogenide nanotubes X-M-Y (X, Y = S, Se, Te; M = Mo, W, Nb, Ta): a computational study.

Similar to graphene and hexagonal boron nitride (h-BN), the two-dimensional (2D) transition metal dichalcogenide (TMD) can be rolled into one-dimensional (1D) nanotubes. While, owing to their three-atom-thick structure, the large energy penalty greatly hinders the synthesis of small diameter TMD nanotubes. Here we propose the synthesis of hybrid TMD nanotubes with different chalcogens on each side (X-TM-Y) by self-assembly rolling up.