Pulsed laser deposition of a Ga2O3 thin film for an optoelectronic synaptic device.

With the rapid development of information era, the traditional von Neumann architecture faces the computing bottleneck, and integration of memory and perception is regarded as a potential solution. Herein, a Ga2O3/Si heterojunction based multi-modulated optoelectronic synaptic device is fabricated and demonstrated. As stimulated by ultraviolet (UV) optical spikes, the heterojunction device reveals typical synaptic functions of excitatory-postsynaptic current (EPSC), paired-pulse facilitation (PPF), spike-timing-dependent plasticity (STDP), and switch between short-term memory (STM) and long-term memory (LTM). In addition, stronger stimulations like higher reading voltage, stronger optical stimulated intensity, and longer pulse duration time can significantly prolong the attenuation of EPSC, which contributes to the improvement of the forgetting process. Our work provides a potential strategy for future neuromorphic computation through a UV light driven stimulation.

Thickness-modulated passivation properties of PEDOT:PSS layers over crystalline silicon wafers in back junction organic/silicon solar cells.

PEDOT: PSS/silicon heterojunction solar cell has recently attracted much attention due to the fact that it can be simply and cost-effectively fabricated. It is crucial to suppress the interfacial recombination rate between silicon (Si) and organic film for improving device efficiency. In this study, we demonstrated a thickness-dependent passivation effect, i.e. the passivation quality over Si substrate was promoted dramatically with increasing the thickness of PEDOT:PSS layer. The effective minority carrier lifetime increased from 32 µs for 50 nm to 360 µs for 200 nm, which corresponds to a change in implied open circuit voltage (V oc-implied) from 545 to 635 mV. Back-junction hybrid solar cells featuring PEDOT:PSS films at rear side were designed to enable adoption of thick PEDOT:PSS layers without having to worry about parasitic absorption, showing a power conversion efficiency (PCE) of 16.3%. Combined with a proper pre-condition on the Si substrate, the back-junction hybrid solar cell with 200 nm PEDOT:PSS layer received an enhanced PCE of 16.8%. In addition, the improved long-term stability for the back-junction device was also observed. The PCE remained 90% (unsealed) after being stored in ambient atmosphere for 30 days and over 80% (sealed) after 150 days.

The role of XBP1s in the metastasis and prognosis of hepatocellular carcinoma.

Tumor metastasis and recurrence are the primary contributors to poor prognosis in patients with hepatocellular carcinoma (HCC). The epithelial-mesenchymal transition (EMT) of tumor cells is the predominant mechanism of HCC progression. XBP1s is a newly discovered molecule involved in the endoplasmic reticulum (ER) stressresponse, which is an adaptive response and defense mechanism in cells that enablessurvival under adverse conditions. Abnormally high XBP1sexpression has been found in tumor cells, but the role of XBP1sin HCC progression remains unclear. We found that the expression of XBP1s in HCC cell lines and tissuesamples was higher than that in control cells and tissuesamples. Clinicopathological analysis showed that the expression of XBP1s was closely correlated with distant metastasis and poor prognosis in HCC. In vivo and invitro experiments confirmed that the overexpression of XBP1s promoted EMT and metastasis in HCC cells. XBP1ssilencing attenuated cellular migration and development of the EMT phenotypein vitro. Through further study to elucidate the molecular mechanism underlying the promotion ofEMT by XBP1s in HCC cells, we confirmed that XBP1s could mediate the expression of Twist. In HCC cells, XBP1s enhanced the expression of Twist and Snail, resulting in a subsequent reduction in the expression of E-cadherin, a contributor to cell-cell adhesion. Overall, this study reveals a novel XBP1s/Twist/Snail axis that mediates EMT in HCC cells and the invasion and metastasis of HCC.

A Targeted and Stable Polymeric Nanoformulation Enhances Systemic Delivery of mRNA to Tumors.

The high vulnerability of mRNA necessitates the manufacture of delivery vehicles to afford adequate protection in the biological milieu. Here, mRNA was complexed with a mixture of cRGD-poly(ethylene glycol) (PEG)-polylysine (PLys) (thiol) and poly(N-isopropylacrylamide) (PNIPAM)-PLys(thiol). The ionic complex core consisting of opposite-charged PLys and mRNA was crosslinked though redox-responsive disulfide linkage, thereby avoiding structural disassembly for exposure of mRNA to harsh biological environments. Furthermore, PNIPAM contributed to prolonged survival in systemic circulation by presenting a spatial barrier in impeding accessibility of nucleases, e.g., RNase, due to the thermo-responsive hydrophilic-hydrophobic transition behavior upon incubation at physiological temperature enabling translocation of PNIPAM from shell to intermediate barrier. Ultimately, the cRGD ligand attached to the formulation demonstrated improved tumor accumulation and potent gene expression, as manifested by virtue of facilitated cellular uptake and intracellular trafficking. These results indicate promise for the utility of mRNA as a therapeutic tool for disease treatment.

Improved optical absorption in visible wavelength range for silicon solar cells via texturing with nanopyramid arrays.

Surface-texture with silicon (Si) nanopyramid arrays has been considered as a promising choice for extremely high performance solar cells due to their excellent anti-reflective effects and inherent low parasitic surface areas. However, the current techniques of fabricating Si nanopyramid arrays are always complicated and cost-ineffective. Here, a high throughput nanosphere patterning method is developed to form periodic upright nanopyramid (UNP) arrays in wafer-scale. A direct comparison with the state-of-the-art texture of random pyramids is demonstrated in optical and electronic properties. In combination with the antireflection effect of a SiNx coating layer, the periodic UNP arrays help to provide a remarkable improvement in short-wavelength response over the random pyramids, attributing to a short-current density gain of 1.35 mA/cm2. The advanced texture of periodic UNP arrays provided in this work shows a huge potential to be integrated into the mass production of high-efficiency Si solar cells.

High-rate and wide-area deposition of epitaxial Si films by mesoplasma chemical vapor deposition.

Homoepitaxial Si films have been deposited at a high rate of 200 nm s-1 over a wide area of 20 mm × 80 mm by cluster-assisted mesoplasma chemical vapor deposition (MPCVD) on a moving substrate. The obtained epitaxial Si films exhibited a uniform roughness of 0.1-0.3 nm (1 × 1 µm2) and a Hall mobility of ∼240 cm2 V-1 s-1. The results suggested that under the MPCVD the deposition precursors formed at the plasma edge could be small enough not to influence either epitaxial film structure or the film quality provided the substrate temperature is maintained above 500 °C.

Beyond Mechanical Protection: The Electron-Shielding Effect of SWCNT for the Stabilized SiO Interface.

The single-walled carbon nanotube (SWCNT) commonly serves as a conductive additive for SiO-based anode materials due to the excellent conductivity and mechanical properties. However, the potential action mechanisms for the SWCNT beyond conductivity and mechanical features have rarely been studied. Herein, an interfacial electron-shielding effect and preferential adsorption to the electrolyte components for the SWCNT are revealed through a series of advanced characterizations and density functional theory (DFT) simulations. It can be determined that SWCNT networks could restrict the transmission of the electron from SiO interface to electrolyte with the reduced decomposition, because of the typical axial conductivity of the SWCNT. Moreover, the SWCNT shows stronger adsorption energy for LiPF6 and ethylene carbonate (EC) molecules, rather than nonselectivity of traditional carbon additives, facilitating the generation of inorganic-rich and denser solid electrolyte interface (SEI) film. As a result, benefiting from the electron-shielding effect, preferential adsorption, and mechanical protection, the SWCNT endows the SiO@C anode with a higher average Coulombic efficiency (CE) value of 99.4% over 100 cycles and a long cycling stability.

A highly orientational architecture formed by covalently bonded graphene to achieve high through-plane thermal conductivity of polymer composites.

Combining the advantages of high thermal conductivities and low graphene contents to fabricate polymer composites for applications in thermal management is still a great challenge due to the high defect degree of exfoliated graphene, the poor orientation of graphene in polymer matrices, and the horrible phonon scattering between graphene/graphene and graphene/polymer interfaces. Herein, mesoplasma chemical vapor deposition (CVD) technology was successfully employed to synthesize vertically aligned graphene nanowalls (GNWs), which are covalently bonded by high-quality CVD graphene nanosheets. The unique architecture leads to an excellent thermal enhancement capacity of the GNWs, and a corresponding composite film with a matrix of polyvinylidene fluoride (PVDF) presented a high through-plane thermal conductivity of 12.8 ± 0.77 W m-1 K-1 at a low filler content of 4.0 wt%, resulting in a thermal conductivity enhancement per 1 wt% graphene loading of 1659, which is far superior to that using conventional graphene structures as thermally conductive pathways. In addition, this composite exhibited an excellent capability in cooling a high-power light-emitting diode (LED) device under real application conditions. Our finding provides a new route to prepare high-performance thermal management materials with low filler loadings via the rational design of the microstructures/interfaces of graphene skeletons.

Three-dimensional visualization of lithium metal anode via low-dose cryogenic electron microscopy tomography.

The structure of lithium (Li) metal anode, including the Li metal and the solid electrolyte interphase (SEI), is critical to the investigation of cycle stability or decay mechanisms. The three-dimensional (3D) visualization of Li metal and SEI, however, has not been demonstrated yet, owing to the lack of 3D characterization techniques and the susceptibility of Li metal anode toward oxygen, moisture, as well as electron beam. Herein, we introduce a successful 3D presentation of deposited Li metal and SEI established via low-dose cryogenic electron microscopy tomography. The Li metal anode is imaged in low-dose mode at different tilt angles and then aligned and reconstructed into a 3D image through an expectation-maximization algorithm. The spherical Li deposits and SEI are confirmed in the 3D tomography of Li metal anode. It is also discovered that the Li metal corrodes and SEI turns concave owing to possible self-discharge after long-time rest.

Atomic-scale insights into the interfacial instability of superlubricity in hydrogenated amorphous carbon films.

The origin of instability or even disappearance of the superlubricity state in hydrogenated amorphous carbon (a-C:H) film in the presence of oxygen or water molecules is still controversial. Here, we address this puzzle regarding the tribochemical activities of sliding interfaces at the nanoscale. The results reveal that gaseous oxygen molecules disable the antifriction capacity of a-C:H by surface dehydrogenation of tribo-affected hydrocarbon bonds. In comparison, oxygen incorporation into the hydrocarbon matrix induces the formation of a low-density surface shear band, owing to which the friction state depends on the oxygen content. High friction of a-C:H film in humid environment originates from the "tumor-like" heterogeneous structures as formed in the highly oxidized tribolayer. Notably, an appropriate doping of silicon can completely shield the moisture effect by forming a silica-like tribolayer. These outcomes shed substantial lights upon the roadmap for achieving robust superlubricity of carbon films in a wide range of environments.

STAT3-induced upregulation of lncRNA ABHD11-AS1 promotes tumour progression in papillary thyroid carcinoma by regulating miR-1301-3p/STAT3 axis and PI3K/AKT signalling pathway.

OBJECTIVES: Emerging evidences indicated the importance of long non-coding RNAs (lncRNAs) in the tumorigenesis and deterioration of malignant tumours. To our knowledge, the study about lncRNAs in papillary thyroid carcinoma (PTC) is still inadequate. ABHD11-AS1 was highly expressed in the PTC samples of The Cancer Genome Atlas database. This study focused on the biological function and mechanism of lncRNA ABHD11-AS1 in PTC. MATERIALS AND METHODS: qRT-PCR analysis was used to examine the expression of ABHD11-AS1 in PTC tissues and cell lines. The prognostic significance of ABHD11-AS1 for the patients with PTC was analysed with Kaplan-Meier analysis. The effects of ABHD11-AS1 knockdown on the cell proliferation and metastasis were evaluated by in vitro functional assays and in vivo experiments. The molecular mechanism which contributed to the oncogenic role of ABHD11-AS1 in PTC was explored by conducting mechanism experiments. Rescue assays were carried out for final demonstration. RESULTS: High expression of ABHD11-AS1 predicted poor prognosis for patients with PTC and promoted cell proliferation and metastasis in vitro and in vivo. ABHD11-AS1 was activated by the transcription factor STAT3. ABHD11-AS1 positively regulated PI3K/AKT signalling pathway. ABHD11-AS1 acted as a competitive endogenous (ce) RNA to upregulate STAT3 by sponging miR-1301-3p. CONCLUSIONS: STAT3-induced lncRNA ABHD11-AS1 promoted PTC progression by regulating PI3K/AKT signalling pathway and miR-1301-3p/STAT3 axis.

Superoxide dismutase transcellular shuttle constructed from dendritic MOF and charge reversible protein derivatives.

The development of molecular biology has led to the identification of protein-based therapeutics as an intriguing approach for the treatment of a wide range of diseases. To manufacture transcellular protein delivery shuttles, we attempted charge reversal chemistry on native proteins [e.g., superoxide dismutase (SOD): an enzyme capable of scavenging detrimental reactive oxygen species] by the selective conversion of the positively charged amino residues of native SOD to conjugated negatively charged citraconic moieties, eliciting overall negatively charged polyelectrolytes for the subsequent electrostatic self-assembly with cationic metal-organic framework (MOF) derivatives into protein delivery systems. Please note that the charge conversion was reversible, restoring the original amino groups in intracellular acidic endosome compartments (pH 5), which afforded facile charge reversible functions to reclaim the active SOD in the cell interior. In particular, the strategic manufacture of dendritic MOF supramolecular architectures as transcellular shuttles for the aforementioned charge-reversible SOD derivatives is noteworthy. The MOF was surface-functionalized with several polycationic segments, thus contributing to the hyper-charged architecture for the easy accommodation of the negatively charged SOD derivatives. Consequently, the SOD derivatives managed to internalize into cells by hitchhiking via endocytosis of the positively charged MOF. Once they resided in the acidic endosomes, the charge reversal of the SOD derivatives could occur smoothly and result in reduced interactions between the charged-reversed SOD and MOF, leading to the release of active SOD. Simultaneously, the dendritic MOF due to protein release presented a highly positive-charged architecture to provoke endosome membrane disruption, consequently spurring the translocation of SOD to the cytosol for the execution of its enzymatic activities. Herein, the intracellular ROS level of the activated macrophages was validated to be markedly suppressed by our proposed transcellular SOD shuttles, thereby indicating their wide availability to diverse functional proteins for biomedical applications.

Transcellular delivery of messenger RNA payloads by a cationic supramolecular MOF platform.

A supramolecular catiomer with a metal-organic framework (MOF) motif was developed to manufacture messenger RNA (mRNA) assemblies. In contrast to the linear catiomer, the dendritic MOF catiomer appeared to markedly improve the colloidal stability of the mRNA assemblies, particularly affording substantial protection to the mRNA payloads from enzymatic degradation, eventually conducing to appreciable mRNA transfection activities at the targeted cells.

Tumor-Targeted Accumulation of Ligand-Installed Polymeric Micelles Influenced by Surface PEGylation Crowdedness.

With respect to the intriguing biocompatibility and the stealthy functions of poly(ethylene glycol) (PEG), PEGylated nanoparticulates have been intensively engineered for utilities as drug delivery vehicles. To advocate the targeted drug transportation, targeting ligands were strategically installed onto the surface of PEGylated nanoparticulates. The previous in vitro investigations revealed that the ligand-specified cell endocytosis of nanoparticulates was pronounced for the nanoparticulates with adequately high PEG crowdedness. The present study aims to explore insight into the impact of PEGylation degree on in vivo tumor-targeted accumulation activities of cRGD-installed nanoparticulates. The subsequent investigations verified the importance of the PEGylation crowdedness in pursuit of prolonged retention in the blood circulation post intravenous administration. Unprecedentedly, the PEGylation crowdedness was also identified as a crucial important parameter to pursue the tumor-targeted accumulation. A plausible reason is the elevated PEGylation crowdedness eliciting the restricted involvement in nonspecific protein adsorption of nanoparticulates in the biological milieu and consequently pronouncing the ligand-receptor-mediated binding for the nanoparticulates. Noteworthy was the distinctive performance of the class of the proposed systems once utilized for transportation of the mRNA payload to the tumors. The protein expression in the targeted tumors appeared to follow a clear PEGylation crowdedness dependence manner, where merely 2-fold PEGylation crowdedness led to remarkably 10-fold augmentation in protein expression in tumors. Hence, the results provided important information and implications for design of active-targeting PEGylated nanomaterials to fulfill the targeting strategies in systemic applications.

Controlled PEGylation Crowdedness for Polymeric Micelles To Pursue Ligand-Specified Privileges as Nucleic Acid Delivery Vehicles.

A facile poly(ethylene glycol) (PEG) detachment scheme was utilized to control the PEGylation degree of the polymeric micelles. The performance of cyclic Arg-Gly-Asp (cRGD) as a targeted moiety was studied on a class of polymeric micelles with various PEGylation degrees, revealing that the specific cRGD-mediated cell affinity, thus the cellular uptake and implicated privileges including the ligand-specified favorable intracellular trafficking and consequent favorable biofunctions, was prominent for the polymeric micelles with high PEGylation degree. These results endow important information and implications for the design and development of targeted nanomedicine, particularly the delivery of vulnerable biological compounds.

Photoinduced Field-Effect Passivation from Negative Carrier Accumulation for High-Efficiency Silicon/Organic Heterojunction Solar Cells.

Carrier recombination and light management of the dopant-free silicon/organic heterojunction solar cells (HSCs) based on poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) are the critical factors in developing high-efficiency photovoltaic devices. However, the traditional passivation technologies can hardly provide efficient surface passivation on the front surface of Si. In this study, a photoinduced electric field was induced in a bilayer antireflective coating (ARC) of polydimethylsiloxane (PDMS) and titanium oxide (TiO2) films, due to formation of an accumulation layer of negative carriers (O2- species) under UV (sunlight) illumination. This photoinduced field not only suppressed the silicon surface recombination but also enhanced the built-in potential of HSCs with 84 mV increment. In addition, this photoactive ARC also displayed the outstanding light-trapping capability. The front PEDOT:PSS/Si HSC with the saturated O2- received a champion PCE of 15.51% under AM 1.5 simulated sunlight illumination. It was clearly demonstrated that the photoinduced electric field was a simple, efficient, and low-cost method for the surface passivation and contributed to achieve a high efficiency when applied in the Si/PEDOT:PSS HSCs.

Evolution of tribo-induced interfacial nanostructures governing superlubricity in a-C:H and a-C:H:Si films.

Hydrogenated amorphous carbon (a-C:H) is capable of providing a near-frictionless lubrication state when rubbed in dry sliding contacts. Nevertheless, the mechanisms governing superlubricity in a-C:H are still not well comprehended, mainly due to the lack of spatially resolved structural information of the buried contact surface. Here, we present structural analysis of the carbonaceous sliding interfaces at the atomic scale in two superlubricious solid lubricants, a-C:H and Si-doped a-C:H (a-C:H:Si), by probing the contact area using state-of-the-art scanning electron transmission microscopy and electron energy-loss spectroscopy. The results emphasize the diversity of superlubricity mechanisms in a-C:Hs. They suggest that the occurrence of a superlubricious state is generally dependent on the formation of interfacial nanostructures, mainly a tribolayer, by different carbon rehybridization pathways. The evolution of such anti-friction nanostructures highly depends on the contact mechanics and the counterpart material. These findings enable a more effective manipulation of superlubricity and developments of new carbon lubricants with robust lubrication properties.

Si/PEDOT:PSS Hybrid Solar Cells with Advanced Antireflection and Back Surface Field Designs.

Molybdenum oxide (MoO3) is one of most suitable antireflection (AR) layers for silicon/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (Si/ PEDOT: PSS) hybrid solar cells due to its well-matched refractive index (2.1). A simulation model was employed to predict the optical characteristics of Si/ PEDOT: PSS hybrid solar cells with the MoO3 layers as antireflection coatings (ARCs), as well as to analyze the loss in current density. By adding an optimum thickness of a 34-nm-thick ARC of MoO3 on the front side and an effective rear back surface field (BSF) of phosphorus-diffused N (+) layer at the rear side, the hybrid cells displayed higher light response in the visible and near infrared regions, boosting a short-circuit current density (J sc) up to 28.7 mA/cm(2). The average power conversion efficiency (PCE) of the Si/ PEDOT: PSS hybrid solar cells was thus increased up to 11.90 %, greater than the value of 9.23 % for the reference devices.

Overexpression of B7-H3 correlates with aggressive clinicopathological characteristics in non-small cell lung cancer.

Previous studies have investigated the prognostic significance of B7 homolog 3 (B7-H3) in non-small cell lung cancer (NSCLC), however, the results remain controversial. This study was aimed to determine the correlation between B7-H3 and survival as well as clnicalpathological characteristics in NSCLC using meta-analysis. We searched the electronic databases of PubMed, Embase, Web of Science, and China National Knowledge Infrastructure (CNKI) for relevant studies up to October 9, 2016. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were used to estimate the impact of B7-H3 on overall survival (OS). Combined odds ratios (ORs) and 95%CIs were utilized to evaluate the correlations between B7-H3 and clinicalpathological features. This meta-analysis finally included 7 studies with 864 patients. The results showed that B7-H3 had no significant association with OS (HR=0.88, 95%CI: 0.36-2.13, p=0.776). High B7-H3 expression was a significant indicator of lymph node metastasis (OR=3.92, 95%CI: 2.65-5.81, p<0.001), and advanced TNM stage (OR=3.53, 95%CI: 2.45-5.09, p<0.001). B7-H3 has the potential to serve as a marker of tumor aggressiveness and lymph node metastasis in NSCLC. However, due to several limitations, further large-scale studies are needed to validate our results.

Clinical value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in evaluating relapsed and refractory nasopharyngeal carcinoma: A case report.

For patients with locoregionally advanced nasopharyngeal carcinoma (NPC), radiotherapy, chemotherapy and even targeted therapy are widely accepted treatments. These treatments, although they mostly achieve locoregional tumor control, they may also be associated with complex post-treatment changes, such as edema, loss of tissue planes, fibrosis, mucositis and scarring, which may interfere with the detection of local recurrence and the response to therapy. However, timely detection is crucial for deciding whether treatment modification or discontinuation is required. This is the case report of A 51-year-old nasopharyngeal carcinoma patient with cervical nodal metastases (CNM). Following radiotherapy, chemotherapy and targeted therapy, multislice spiral enhanced computed tomography (CT), enhanced magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT of the neck were performed to compare the extent of the CNM. The enhanced CT and MRI images were unremarkable, whereas the 18F-FDG PET/CT images revealed the exact recurrence or remission. Therefore, 18F-FDG PET/CT exhibits a better sensitivity and specificity for evaluating the response to combined treatment compared to CT and/or MRI.