Strong Second Harmonic Generation from Bilayer Graphene with Symmetry Breaking by Redox-Governed Charge Doping.

Missing second-order nonlinearity in centrosymmetric graphene overshadows its intriguing optical attribute. Here, we report redox-governed charge doping could effectively break the centrosymmetry of bilayer graphene (BLG), enabling a strong second harmonic generation (SHG) with a strength close to that of the well-known monolayer MoS2. Verified from control experiments with in situ electrical current annealing and electrically gate-controlled SHG, the required centrosymmetry breaking of the emerging SHG arises from the charge-doping on the bottom layer of BLG by the oxygen/water redox couple. Our results not only reveal that charge doping is an effective way to break the inversion symmetry of BLG despite its strong interlayer coupling but also indicate that SHG spectroscopy is a valid technique to probe molecular doping on two-dimensional materials.

SCMFMDA: Predicting microRNA-disease associations based on similarity constrained matrix factorization.

miRNAs belong to small non-coding RNAs that are related to a number of complicated biological processes. Considerable studies have suggested that miRNAs are closely associated with many human diseases. In this study, we proposed a computational model based on Similarity Constrained Matrix Factorization for miRNA-Disease Association Prediction (SCMFMDA). In order to effectively combine different disease and miRNA similarity data, we applied similarity network fusion algorithm to obtain integrated disease similarity (composed of disease functional similarity, disease semantic similarity and disease Gaussian interaction profile kernel similarity) and integrated miRNA similarity (composed of miRNA functional similarity, miRNA sequence similarity and miRNA Gaussian interaction profile kernel similarity). In addition, the L2 regularization terms and similarity constraint terms were added to traditional Nonnegative Matrix Factorization algorithm to predict disease-related miRNAs. SCMFMDA achieved AUCs of 0.9675 and 0.9447 based on global Leave-one-out cross validation and five-fold cross validation, respectively. Furthermore, the case studies on two common human diseases were also implemented to demonstrate the prediction accuracy of SCMFMDA. The out of top 50 predicted miRNAs confirmed by experimental reports that indicated SCMFMDA was effective for prediction of relationship between miRNAs and diseases.

Designing a 0D/1D S-Scheme Heterojunction of Cadmium Selenide and Polymeric Carbon Nitride for Photocatalytic Water Splitting and Carbon Dioxide Reduction.

Constructing photocatalysts to promote hydrogen evolution and carbon dioxide photoreduction into solar fuels is of vital importance. The design and establishment of an S-scheme heterojunction system is one of the most feasible approaches to facilitate the separation and transfer of photogenerated charge carriers and obtain powerful photoredox capabilities for boosting photocatalytic performance. Herein, a zero-dimensional/one-dimensional S-scheme heterojunction composed of CdSe quantum dots and polymeric carbon nitride nanorods (CdSe/CN) is created and constructed via a linker-assisted hybridization approach. The CdSe/CN composites exhibit superior photocatalytic activity in water splitting and promoted carbon dioxide conversion performance compared with CN nanorods and CdSe quantum dots. The best efficiency in photocatalytic water splitting (10.2% apparent quantum yield at 420 nm irradiation, 20.1 mmol g-1 h-1 hydrogen evolution rate) and CO2 reduction (0.77 mmol g-1 h-1 CO production rate) was achieved by 5%CdSe/CN composites. The significantly improved photocatalytic reactivity of CdSe/CN composites primarily originates from the emergence of an internal electric field in the zero-dimensional/one-dimensional S-scheme heterojunction, which could greatly improve the photoinduced charge-carrier separation. This work underlines the possibility of employing polymeric carbon nitride nanostructures as appropriate platforms to establish highly active S-scheme heterojunction photocatalysts for solar fuel production.

Platelet-derived growth factor-B (PDGF-B) induced by hypoxia promotes the survival of pulmonary arterial endothelial cells through the PI3K/Akt/Stat3 pathway.

BACKGROUND/AIMS: Pulmonary arterial endothelial plexiform lesions are a basic pathological change associated with pulmonary vascular remodeling and are characterized by the formation of tumorlets as a result of over-growth of endothelial cells. Accumulating evidence suggests that platelet-derived growth factor (PDGF) participates in regulating the progression of pulmonary arterial hypertension. However, whether PDGF promotes the survival of pulmonary arterial endothelial cells (PAECs), as well as the specific molecular mechanisms that underlie its actions, remains unknown. METHODS: MTT assays, caspase-3 and caspase-9 activity assays and western blot analysis were performed. RESULTS: We found that both the mRNA and protein expression of PDGF-B was induced by hypoxia and that the inhibitory effects exerted by hypoxia on apoptosis were attenuated by inhibitors of PDGF beta. Moreover, PDGF-B inhibited apoptosis in a dose-dependent manner by stimulating the phosphorylation of both Akt and Stat3, and the PI3K/AKT pathway serves as an up-stream participant in the Stat3 activation stimulated by PDGF-B. Additionally, the anti-apoptotic effects of PDGF-B were abolished when PAECs were treated with either an inhibitor or small interfering RNA targeting Stat3. CONCLUSIONS: These observations suggest that PDGF-B is induced by hypoxia and protects against apoptosis via the PI3K/Akt/Stat3 signaling pathway.

Sol processing of conjugated carbon nitride powders for thin-film fabrication.

The chemical protonation of graphitic carbon nitride (CN) solids with strong oxidizing acids, for example HNO3, is demonstrated as an efficient pathway for the sol processing of a stable CN colloidal suspension, which can be translated into thin films by dip/disperse-coating techniques. The unique features of CN colloids, such as the polymeric matrix and the reversible hydrogen bonding, result in the thin-film electrodes derived from the sol solution exhibiting a high mechanical stability with improved conductivity for charge transport, and thus show a remarkably enhanced photo-electrochemical performance. The polymer system can in principle be broadly tuned by hybridization with desired functionalities, thus paving the way for the application of CN for specific tasks, as exemplified here by coupling with carbon nanotubes.

A Unique Ternary Semiconductor-(Semiconductor/Metal) Nano-Architecture for Efficient Photocatalytic Hydrogen Evolution.

It has been a long-standing demand to design hetero-nanostructures for charge-flow steering in semiconductor systems. Multi-component nanocrystals exhibit multifunctional properties or synergistic performance, and are thus attractive materials for energy conversion, medical therapy, and photoelectric catalysis applications. Herein we report the design and synthesis of binary and ternary multi-node sheath hetero-nanorods in a sequential chemical transformation procedure. As verified by first-principles simulations, the conversion from type-I ZnS-CdS heterojunction into type-II ZnS-(CdS/metal) ensures well-steered collections of photo-generated electrons at the exposed ZnS nanorod stem and metal nanoparticles while holes at the CdS node sheaths, leading to substantially improved photocatalytic hydrogen-evolution performance.

Photoinduced reversible shape conversion of silver nanoparticles assisted by TiO2.

Silver nanoprisms were transformed into nanodecahedra through photoinduction of ultraviolet (UV) light in the presence of titanium dioxide (TiO2) quantum dots (QDs). Subsequently, the silver nanodecahedra were reconverted to silver nanoprisms under sodium lamp if there was sufficient citrate in the reaction system. The localized surface plasmon resonance (LSPR) optical properties of silver nanoparticles were tuned during photoinduced shape conversion. The photocatalytic activity of TiO2 QDs assisted the conversion of prisms to decahedra upon UV light irradiation. Nevertheless, the presence of TiO2 did not inhibit the photoinduced reconversion from decahedra to prisms by sodium light. It was demonstrated that citrate was indispensable in the photoinduction process. In addition, oxygen in solution played a vital role in the reversible shape conversion of silver nanoparticles. Moreover, simulated sunlight can convert silver nanoprisms to nanodecahedra instead of UV light with assistance of TiO2 QDs, which would promote the photoinduced reaction of silver nanoparticles based on a natural light source.

Rapid Analysis of Seven Polyamines in Nephotettix cincticeps by Using Ultra-Performance Liquid Chromatography-Triple Quadrupole Mass Spectrometry.

A fast, simple, and sensitive method for the simultaneous determination of seven polyamines in Nephotettix cincticeps was developed based on ultra-performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-3Q-MS) together with liquid phase extraction. Polyamines in insect samples were extracted with HClO4 solution and then were separated and detected by UPLC-3Q-MS, which was equipped with a hydrophilic interaction liquid chromatography column, within 5 min without any derivatization procedure. The method has been successfully used to detect 7 polyamines in healthy and difluormethylornithine-treated adults of Nephotettix cincticeps with a method limit of detection and the method limit of quantitation of 24-139 pg/mg and 82-464 pg/mg, respectively, an intraday and interday relative standard deviation (RSD, n = 5) of 1.97-6.00% and 2.08-5.92% respectively, and a recovery of 86-115%. The success of this study provided a reliable method for the rapid and high-throughput detection of polyamines in the insect sample.

Facile synthesis of hierarchical W18O49 microspheres by solvothermal method and their optical absorption properties.

In this study, a simple route for the synthesis of hierarchical W18O49 assembled by nanowires is reported. The morphologies and formation of W18O49 single-crystal could be controlled by changing the concentration of WCl6-ethanol solution. This synthesis strategy has the advantages that the hierarchical W18O49 microspheres could be economic synthesized at 180 °C without adding additives. Furthermore, efficient optical absorption properties in ultraviolet, visible and near-infrared region were obtained for the hierarchical W18O49 microspheres comparing with nanowires. These results will further promote the research of tungsten-based oxide nanomaterials.

A giant intrinsic photovoltaic effect in atomically thin ReS2.

The photovoltaic (PV) effect in non-centrosymmetric materials consisting of a single component under homogeneous illumination can exceed the fundamental Shockley-Queisser limit compared to the traditional p-n junctions. Two-dimensional (2D) materials with a reduced dimensionality and smaller bandgap were predicated to be better candidates for the PV effect with high efficiency exceeding that of traditional ferroelectric perovskite oxides. Here, we report the giant intrinsic PV effect in atomically thin rhenium disulfide (ReS2) with centrosymmetry breaking. In graphene/ReS2/graphene sandwich structures, significant short-circuit currents (Isc) were observed with illumination over the visible spectral range, presenting the highest responsivity (110 mA W-1) and external quantum efficiency (25.7%) among those reported PV effects in 2D materials. This giant PV effect could be ascribed to the spontaneous-polarization induced depolarization field in even-number-layered ReS2 flakes benefiting from the distorted 1T lattice structure. Our results provide a new potential candidate material for the development of novel high-efficiency, miniaturized and easily integrated photodetectors and solar cells.

CVD Synthesis of Twisted Bilayer WS2 with Tunable Second Harmonic Generation.

The introduction of rotational freedom by twist angles in twisted bilayer (TB) transition metal dichalcogenides (TMDCs) can tailor the inherent properties of the TMDCs, which provides a promising platform to investigate the exotic physical properties. However, direct synthesis of high-quality TB-TMDCs with full twist angles is significantly challenging due to the substantial energy barriers during crystal growth. Here, a modified chemical vapor deposition strategy is proposed to synthesize TB-WS2 with a wide twist angle range from 0° to 120°. Utilizing a tilted SiO2/Si substrate, a gas flow disturbance is generated in the furnace tube to create a heterogeneous concentration gradient of the metal precursor, which provides an extra driving force for the growth of TB-WS2. The Raman and photoluminescence results confirm a weak interlayer coupling of the TB-WS2. High-quality periodic Moiré patterns are observed in the scanning transmission electron microscopy images. Moreover, owing to the strong correlation between the nonlinear optical response and the twisted crystal structure, tunable second harmonic generation behaviors are realized in the TB-WS2. This approach opens up a new avenue for the direct growth of high-crystalline-quality and pristine TB-TMDCs and their potential applications in nonlinear optical devices.

Acceleration effect of reduced graphene oxide on photoinduced synthesis of silver nanoparticles.

The photoinduced growth reaction of silver nanoparticles was accelerated by reduced graphene oxide (RGO) produced from graphene oxide (GO) during the light irradiation process in aqueous solution. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy demonstrated that RGO was generated in the photoinduced process. The acceleration effect of RGO was investigated through monitoring the extinction spectra of silver nanoparticles during the synthesis process. Moreover, transmission electron microscopy (TEM) was employed to characterize the evolution of morphologies of silver nanoparticles at different irradiation times to demonstrate the effect of RGO. The results indicate that RGO accelerates the photoinduced synthesis of silver nanoparticles. It is proposed that the acceleration effect of RGO on the photoinduced reaction is attributed to the particular property of high electronic conductivity.

Emergent second-harmonic generation in van der Waals heterostructure of bilayer MoS2 and monolayer graphene.

Van der Waals (vdW) stacking of two-dimensional (2D) materials to create artificial structures has enabled remarkable discoveries and novel properties in fundamental physics. Here, we report that vdW stacking of centrosymmetric 2D materials, e.g., bilayer MoS2 (2LM) and monolayer graphene (1LG), could support remarkable second-harmonic generation (SHG). The required centrosymmetry breaking for second-order hyperpolarizability arises from the interlayer charge transfer between 2LM and 1LG and the imbalanced charge distribution in 2LM, which are verified by first-principles calculations, Raman spectroscopy, and polarization-resolved SHG. The strength of SHG from 2LM/1LG is of the same order of magnitude as that from the monolayer MoS2, which is well recognized with strong second-order nonlinearity. The emergent SHG reveals that the interlayer charge transfer can effectively modify the symmetry and nonlinear optical properties of 2D heterostructures. It also indicates the great opportunity of SHG spectroscopy for characterizing interlayer coupling in vdW heterostructures.

Vertical Emitting Nanowire Vector Beam Lasers.

Due to the peculiar structured light field with spatially variant polarizations on the same wavefront, vector beams (VBs) have sparked research enthusiasm in developing advanced super-resolution imaging and optical communications techniques. A compact VB nanolaser is intriguing for VB applications in miniaturized photonic integrated circuits. However, determined by the diffraction limit of light, it is a challenge to realize a VB nanolaser in the subwavelength scale because the VB lasing modes should have laterally structured distributions. Here, we demonstrate a VB nanolaser made from a 300 nm thick InGaAs/GaAs nanowire (NW). To select the high-order VB lasing mode, a standing NW as-grown from the selective-area-epitaxial (SAE) growth process is utilized, which has a bottom donut-shaped interface with the silicon oxide growth substrate. With this donut-shaped interface as one of the reflective mirrors of the nanolaser cavity, the VB lasing mode has the lowest threshold. Experimentally, a single-mode VB lasing mode with a donut-shaped amplitude and azimuthally cylindrical polarization distribution is obtained. Together with the high yield and uniformity of the SAE-grown NWs, our work provides a straightforward and scalable path toward cost-effective co-integration of VB nanolasers on potential photonic integrated circuits.

Moyamoya syndrome with ruptured aneurysm in α-thalassemia: A case report.

Moyamoya syndrome (MMS) refers to the moyamoya vascular disease associated with various systemic diseases and conditions, including sickle cell anemia, Fanconi anemia and iron deficiency anemia. However, the association between MMS and other hemoglobinopathies is less frequently observed. MMS, like moyamoya disease, is a cerebrovascular condition that is characterized by chronic progressive stenosis or occlusion at the ends of the bilateral internal carotid arteries, anterior cerebral arteries and the beginning of the middle cerebral arteries, and is secondary to the formation of an abnormal vascular network at the base of the skull. Patients with MMS are prone to thrombosis, aneurysm and bleeding. The present study reports the case of a 43-year-old man with α-thalassemia who presented with moyamoya vessels with a ruptured aneurysm bleeding into the ventricle. α-thalassemia is considered as an extremely rare but potential cause of MMS. Since MMS is a progressive disease, early diagnosis and treatment is vital to prevent the disease from worsening.

Electrically Tunable Second Harmonic Generation in Atomically Thin ReS2.

Electrical tuning of second-order nonlinearity in optical materials is attractive to strengthen and expand the functionalities of nonlinear optical technologies, though its implementation remains elusive. Here, we report the electrically tunable second-order nonlinearity in atomically thin ReS2 flakes benefiting from their distorted 1T crystal structure and interlayer charge transfer. Enabled by the efficient electrostatic control of the few-atomic-layer ReS2, we show that second harmonic generation (SHG) can be induced in odd-number-layered ReS2 flakes which are centrosymmetric and thus without intrinsic SHG. Moreover, the SHG can be precisely modulated by the electric field, reversibly switching from almost zero to an amplitude more than 1 order of magnitude stronger than that of the monolayer MoS2. For the even-number-layered ReS2 flakes with the intrinsic SHG, the external electric field could be leveraged to enhance the SHG. We further perform the first-principles calculations which suggest that the modification of in-plane second-order hyperpolarizability by the redistributed interlayer-transferring charges in the distorted 1T crystal structure underlies the electrically tunable SHG in ReS2. With its active SHG tunability while using the facile electrostatic control, our work may further expand the nonlinear optoelectronic functions of two-dimensional materials for developing electrically controllable nonlinear optoelectronic devices.

miR-139-5p Regulates the Proliferation of Acute Promyelocytic Leukemia Cells by Targeting MNT.

Acute promyelocytic leukemia (APL) patients with progressive leukocytosis are more likely to have various complications and poor outcomes. However, the regulatory roles of microRNAs in the leukocytosis of APL have not been clarified. Our study aims to evaluate the effects of miRNAs on leukocytosis during induction therapy of APL patients and explore its potential mechanisms. During induction treatment, patients with white blood cell count higher than 10 × 109/L were divided into leukocytosis group and others were nonleukocytosis group. Using microarray assays, we found that miR-139-5p was significantly downregulated in the leukocytosis group. Elevated expression of miR-139-5p inhibited the proliferation of NB4 cells by arresting the cell cycle and inducing apoptosis. We further identified that MNT was a target of miR-139-5p. miR-139-5p significantly inhibited the proliferation, invasion, and migration function of NB4 cells through targeting MNT. Strategies for regulating miR-139-5p or MNT expression might provide new therapeutic approaches for progressive leukocytosis in APL.

In Situ Synthesis of a Double-Layer Chitosan Coating on Cotton Fabric to Improve the Color Fastness of Sodium Copper Chlorophyllin.

Natural dye's poor affinity for cotton and poor fastness properties still hinder its applications in the textile industry. In this study, a doubled-layered chitosan coating was cured on cotton fabric to serve as bio-mordant and form a protective layer on it. Under the optimal treatment conditions, the maximum qe (adsorption amount) of the natural dye sodium copper chlorophyllin (SCC) calculated from the Langmuir isothermal model was raised from 4.5 g/kg to 19.8 g/kg. The dye uptake of the treated fabric was improved from 22.7% to 96.4% at 1% o.w.f. dye concentration. By a second chitosan layer cured on the dyed fabric via the cross-linking method, the wash fastness of the cotton fabric dyed with SCC can be improved from 3 to 5 (ISO 105 C-06). The natural source of the biopolymer material, chitosan, and its ability to biodegrade at end of life met with the initial objective of green manufacturing in applying natural dyes and natural materials to the textile industry.

Molten salt assisted assembly growth of atomically thin boron carbon nitride nanosheets for photocatalytic H2 evolution.

Atomic-level boron carbon nitride nanosheets (BCNNS) have been prepared by a molten salt assisted assembly growth strategy, which effectively promotes the solvation of precursors, minimizes the surface energy and prevents the aggregation of layers. The as-synthesized BCNNS have atomic layered thickness and large lateral size, and show enhanced visible light H2 evolution activity compared to bulk BCN.

A Narrative Review of Injury Incidence, Location, and Injury Factor of Elite Athletes in Snowsport Events.

Snowsport athletes face a high injury risk both during training and in competitions. Reducing injury incidence is crucial for athletes to achieve breakthroughs. This narrative review aimed to summarize and analyze injury data of elite athletes in snowsports and provide references for injury prevention and health security for these athletes and their coaches. A total of 39 studies that investigated snowsport injury were analyzed in the present study. On the basis of injury data of elite athletes in snowsports events, this narrative review focused on four aspects, namely, injury incidence, severity, location and causes. The findings of this review were as follows. (1) The highest injury incidence was recorded in freestyle skiing, followed by alpine skiing and snowboarding, the majority of which were moderate and severe injuries. (2) The proportion of injury in competitions and during training was similar. However, more injuries occurred in official training during the Winter Olympic Games; by contrast, injury proportion was higher in competitions during World Cup/World Championships. (3) The most commonly and severely injured body parts were the knees (29.9%), head and face (12.1%), shoulders and clavicula (10.5%), and lower back (8.9%). The most common injury types were joint and ligament injury (41.5%), fracture and bone stress (24.4%), concussion (11.1%), and muscle/tendon injury (10.7%). (4) The main causes of snowsport injury were collisions, falls, and non-contact injuries. Snowsport injury was also influenced by the skill level of the athletes, gender, course setup and equipment. Future studies should further explore the influence of event characteristics and intrinsic and extrinsic risk factors on snowsport injury. An injury or trauma reconstruction may be developed to predict athletic injuries and provide effective prevention strategies.