Biexcitons-plasmon coupling of Ag@Au hollow nanocube/MoS heterostructures based on scattering spectra.

The strong interaction between light and matter is one of the current research hotspots in the field of nanophotonics, and provides a suitable platform for fundamental physics research such as on nanolasers, high-precision sensing in biology, quantum communication and quantum computing. In this study, double Rabi splitting was achieved in a composite structure monolayer MoS and a single Ag@Au hollow nanocube (HNC) in room temperature mainly due to the two excitons in monolayer MoS. Moreover, the tuning of the plasmon resonance peak was realized in the scattering spectrum by adjusting the thickness of the shell to ensure it matches the energy of the two excitons.

Nanowire dimer optical antenna brightens the surface defects of silicon.

Plasmonic hot spots located between metallic dimer nanostructures have been utilized comprehensively to achieve efficient light emission. However, different from the enhancement occurred in the plasmonic hot spot, the investigation of light emission the hot spot on submicron scale remains challenge. In this work, we have constructed a plasmonic nanowire dimer (NWD) system to brighten the light emission of the surface defects of silicon off the hot spot on the submicron scale.

Resonance Photoluminescence Enhancement of Monolayer MoS via a Plasmonic Nanowire Dimer Optical Antenna.

Two-dimensional transition-metal dichalcogenides (TMDs) such as monolayer MoS exhibit remarkable optical properties. However, the intrinsic absorption and emission rates of MoS are very low, thus severely hindering its application in electronics and photonics. Combining MoS with a plasmonic optical antenna is an alternative solution to enhance the emission rates of the 2D semiconductor, and this can drastically increase the photoresponsivity of the corresponding photodetector.

In Situ Microfluidic SERS Chip for Ultrasensitive Hg Sensing Based on I-Functionalized Silver Aggregates.

Mercury(II) ions are causing serious environmental pollution and health damage. Developing a simple, rapid, and sensitive sensor for Hg detection is of great significance. Herein, we demonstrate an I-functionalized surface-enhanced Raman scattering (SERS) substrate for rapid and sensitive Hg sensing on a highly integrated microfluidic platform.

Plasma-Driven Photocatalysis Based on Gold Nanoporous Arrays.

Various effects caused by surface plasmons including enhanced electromagnetic field, local heating, and excited electrons/holes can not only redistribute the electromagnetic field in the time domain and space but also redistribute the excited carriers and drive chemical reactions. In this study, firstly, an Au nanoporous array photocatalyst with the arrayed gauge was prepared by means of the anodic alumina template. Then, the formation of 4,4'-dimercaptoazobenzene (DMAB) by the surface plasmon-driven photocatalysis under 633 nm laser irradiation was investigated by means of Raman spectroscopy using aminothiophenol (PATP) as a probe molecule on gold nananoporous arrays.

Graphene/SnS van der Waals Photodetector with High Photoresponsivity and High Photodetectivity for Broadband 365-2240 nm Detection.

The fabrication of graphene/SnS van der Waals photodetectors and their photoelectrical properties are systematically investigated. It was found that a dry transferred graphene/SnS van der Waals heterostructure had a broadband sensing range from ultraviolet (365 nm) to near-infrared (2.24 μm) and respective improved responsivities and photodetectivities of 7.

Plasmon-driven photocatalytic properties based on the surface of gold nanostar particles.

Surface plasmon resonance (SPR) generated in gold nanoparticles can induce the conversion of p-Aminothiophenol (PATP) molecules into p,p'-dimercaptoazobenzene (DMAB) molecules by coupling reaction under the action of excitation light. Molecular detection of samples by surface enhanced Raman spectroscopy (SERS) techniques allows the study of their plasma-driven photocatalytic reaction processes. In this study, we used gold nanostars (GNS) as the substrate to study its catalytic performance and sensitivity.

Giant gauge factor of Van der Waals material based strain sensors.

There is an emergent demand for high-flexibility, high-sensitivity and low-power strain gauges capable of sensing small deformations and vibrations in extreme conditions. Enhancing the gauge factor remains one of the greatest challenges for strain sensors. This is typically limited to below 300 and set when the sensor is fabricated.

Charge density waves and degenerate modes in exfoliated monolayer 2H-TaS.

Charge density waves spontaneously breaking lattice symmetry through periodic lattice distortion, and electron-electron and electron-phonon inter-actions, can lead to a new type of electronic band structure. Bulk 2H-TaS is an archetypal transition metal dichalcogenide supporting charge density waves with a phase transition at 75 K. Here, it is shown that charge density waves can exist in exfoliated monolayer 2H-TaS and the transition temperature can reach 140 K, which is much higher than that in the bulk.

Photoelectrical properties of graphene/doped GeSn vertical heterostructures.

GeSn is a group IV alloy material with a narrow bandgap, making it favorable for applications in sensing and imaging. However, strong surface carrier recombination is a limiting factor. To overcome this, we investigate the broadband photoelectrical properties of graphene integrated with doped GeSn, from the visible to the near infrared.

Enhanced NO Sensitivity in Schottky-Contacted n-Type SnS Gas Sensors.

Layered materials are highly attractive in gas sensor research due to their extraordinary electronic and physicochemical properties. The development of cheaper and faster room-temperature detectors with high sensitivities especially in the parts per billion level is the main challenge in this rapidly developing field. Here, we show that sensitivity to NO () can be greatly improved by at least two orders of magnitude using an n-type electrode metal.

Fracturing and Damage of 3D-Printed Materials with Two Intermittent Fissures under Compression.

The crack propagation and failure of 3D-printed samples with prefabricated K-S fissures (a kinked fissure and a straight fissure) were observed under uniaxial compression, and the strain and displacement of the sample surface were quantified by the digital image correlation (DIC) method. The experimental results show that the branch inclination angle of the kinked fissure is an important factor affecting the crack initial position, and the evolution of the strain field during the failure process of the sample can better reflect the cracking law of the internal fissures. Furthermore, two coalescence modes are classified: Mode I is a tension-shear composite failure formed by the penetration of the tension-shear composite crack; Mode II is a tensile failure that penetrates the whole samples during the failure process without rock bridge damage.

Electrical Contact Barriers between a Three-Dimensional Metal and Layered SnS.

Field-effect transistors derived from traditional 3D semiconductors are rapidly approaching their fundamental limits. Layered semiconducting materials have emerged as promising candidates to replace restrictive 3D semiconductor materials. However, contacts between metals and layered materials deviate from Schottky-Mott behavior when determined by transport methods, while X-ray photoelectron spectroscopy measurements suggest that the contacts should be at the Schottky limit.

Sub-millimeter size high mobility single crystal MoSe monolayers synthesized by NaCl-assisted chemical vapor deposition.

Monolayer MoSe is a transition metal dichalcogenide with a narrow bandgap, high optical absorbance and large spin-splitting energy, giving it great promise for applications in the field of optoelectronics. Producing monolayer MoSe films in a reliable and scalable manner is still a challenging task as conventional chemical vapor deposition (CVD) or exfoliation based techniques are limited due to the small domains/nanosheet sizes obtained. Here, based on NaCl assisted CVD, we demonstrate the simple and stable synthesis of sub-millimeter size single-crystal MoSe monolayers with mobilities ranging from 38 to 8 cm V s.

Enhanced NO Sensing at Room Temperature with Graphene via Monodisperse Polystyrene Bead Decoration.

Graphene is a single layer of carbon atoms with a large surface-to-volume ratio, providing a large capacity gas molecule adsorption and a strong surface sensitivity. Chemical vapor deposition-grown graphene-based NO gas sensors typically have detection limits from 100 parts per billion (ppb) to a few parts per million (ppm), with response times over 1000 s. Numerous methods have been proposed to enhance the NO sensing ability of graphenes.

High Selectivity Gas Sensing and Charge Transfer of SnSe.

SnSe is an anisotropic binary-layered material with rich physics, which could see it used for a variety of potential applications. Here, we investigate the gas-sensing properties of SnSe using first-principles calculations and verify predictions using a gas sensor made of few-layer SnSe grown by chemical vapor deposition. Theoretical simulations indicate that electrons transfer from SnSe to NO, whereas the direction of charge transfer is the opposite for NH.

Strategy for Fabricating Wafer-Scale Platinum Disulfide.

PtS is a newly developed group 10 2D layered material with high carrier mobility, wide band gap tunability, strongly bound excitons, symmetrical metallic and magnetic edge states, and ambient stability, making it attractive in nanoelectronic, optoelectronic, and spintronic fields. To the aim of application, a large-scale synthesis is necessary. For transition-metal dichalcogenide (TMD) compounds, a thermally assisted conversion method has been widely used to fabricate wafer-scale thin films.

Photo-enhanced gas sensing of SnS with nanoscale defects.

Recently a SnS based NO gas sensor with a 30 ppb detection limit was demonstrated but this required high operation temperatures. Concurrently, SnS grown by chemical vapor deposition is known to naturally contain nanoscale defects, which could be exploited. Here, we significantly enhance the performance of a NO gas sensor based on SnS with nanoscale defects by photon illumination, and a detection limit of 2.

Temperature-Dependent Photoluminescence Emission from Unstrained and Strained GaSe Nanosheets.

Two-dimensional AB layered semiconductors have recently attracted great attention due to their potential applications in piezo-phototronics and optoelectronics. Here, we report the temperature-dependent photoluminescence (PL) of strained and unstrained GaSe flakes. It is found that, as the temperature increases, the PL from both the strained (wrinkled) and unstrained (flat) positions show a prominent red-shift to low energies.

Role of autophagy and its molecular mechanisms in mice intestinal tract after severe burn.

Background: Severe burn can lead to hypoxia/ischemia of intestinal mucosa. Autophagy is the process of intracellular degradation, which is essential for cell survival under stresses, such as hypoxia/ischemia and nutrient deprivation. The present study was designed to investigate whether there were changes in intestinal autophagy after severe burn in mice and further to explore the effect and molecular mechanisms of autophagy on intestinal injury.

ITF promotes migration of intestinal epithelial cells through crosstalk between the ERK and JAK/STAT3 pathways.

Intestinal trefoil factor (ITF), a member of the trefoil factor family, is a "Super-protective factor" for intestinal mucosal protection. This study was designed to explore the mechanism by which ITF promotes intestinal epithelial cell migration. Intestinal epithelial cells were treated with the human ITF (hITF).

Surface enhanced Raman scattering of monolayer MX2 with metallic nano particles.

Monolayer transition metal dichalcogenides MX2 (M = Mo, W; X = S) exhibit remarkable electronic and optical properties, making them candidates for application within flexible nano-optoelectronics. The ability to achieve a high optical signal, while quantitatively monitoring strain in real-time is the key requirement for applications in flexible sensing and photonics devices. Surface-enhanced Raman scattering (SERS) allows us to achieve both simultaneously.

Race, Exclusionary Discipline, and Connectedness to Adults in Secondary Schools.

This study examines racial differences in students' connectedness to school adults and considers the possibility that disparities in exclusionary discipline practices may reduce all students' sense of connection to educators, not just those who have been disciplined or are from racial groups overrepresented in out-of-school suspensions. Data sources include a self-report survey of secondary school students (n = 29,148) linked to administrative data (n = 107 schools) from a large urban district. Multilevel modeling techniques were used to estimate the relationships between students' racial background, youths' connection to school adults, and school-level racial discipline gaps.

Assessing the influence of obesity on longitudinal executive functioning performance in patients with obstructive sleep apnea syndrome.

Objective: To investigate longitudinal performance on an executive functioning task among individuals with obstructive sleep apnea syndrome (OSAS) and the impact of obesity on performance.

Methods: Participants completed the Trail Making Test Part B (TMT-B), which is an executive functioning task that measured cognitive flexibility, at baseline, 3-, 6-, and 12-month follow-ups. Hierarchical linear modeling (HLM) analyses were used to assess participants' initial performance on the task, as well the trajectories of growth on the task across time points.

Prevalence of developmental delays and participation in early intervention services for young children.

Objectives: The objective of this study was to use a nationally representative longitudinal sample of children born in the United States in 2001 to estimate rates of eligibility for Part C early intervention, to estimate rates of access to services for developmental delays, and to examine factors that are associated with access to services.

Methods: Data for this study were collected as part of the Early Childhood Longitudinal Study, Birth Cohort, which obtained data from participants when children were 9 and 24 months of age. Descriptive analyses were used to generate national estimates of the prevalence of developmental delays that would make children eligible for Part C services and rates of participation in early intervention services.