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• The important designs and exploration of several solar-water-splitting devices with excellent STH are highlighted. • Various solar-to-hydrogen conversion strategies are described. • Photovoltaic hydrogen production research and module progress. Hydrogen, meeting the requirements of sustainable development, is regarded as the ultimate energy in the 21st century. Due to the inexhaustible and feasible of solar energy, solar water splitting is an immensely promising strategy for environmental-friendly hydrogen production, which not only overcomes the fluctuation and intermittency but also contributes to achieving the mission of global "Carbon Neutrality and Carbon Peaking". However, there is still a lack of a comprehensive overview focusing on hydrogen progress with a discussion of development from solar energy to solar cells. Herein, we emphasize several solar-to-hydrogen pathways from the basic concepts and principles and focus on photovoltaic-electrolysis and photoelectrochemical/photovoltaic systems, which have achieved solar-to-hydrogen (STH) efficiency of over 10% and have extremely promising for large-scale application. In addition, we summarize the challenges and opportunities faced in this field including configuration design, electrode materials, and performance evaluation. Finally, perspectives on the potential commercial application and scientific research for the further development of solar-to-hydrogen are analyzed and presented. Hydrogen production holds great promise for meeting the requirements of sustainable development. Given that solar energy is an abundant and renewable source, it is imperative to develop environmentally friendly methods for water splitting. In this context, we provide an overview of recent advances in solar-to-hydrogen conversion, with a particular focus on solar cells, while also exploring key factors influencing the efficiency of solar-to-hydrogen (STH) conversion. Despite the importance of this topic, comprehensive reviews on solar-to-hydrogen are relatively scarce. We hope that our review will provide valuable insights and inspire the development of sustainable energy systems in the near future. [Display omitted] [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) heterostructures with ferromagnetism and ferroelectricity provide a promising avenue to miniaturize the device size, increase computational power, and reduce energy consumption. However, the direct synthesis of such eye-catching heterostructures has yet to be realized up to now. Here, we design a two-step chemical vapor deposition strategy to growth of Cr2S3/WS2vertical heterostructures with atomically sharp and clean interfaces on sapphire. The interlayer charge transfer and periodic moiré superlattice result in the emergence of room-temperature ferroelectricity in atomically thin Cr2S3/WS2vertical heterostructures. In parallel, long-range ferromagnetic order is discovered in 2D Cr2S3via the magneto-optical Kerr effect technique with the Curie temperature approaching 170 K. The charge distribution variation induced by the moiré superlattice changes the ferromagnetic coupling strength and enhances the Curie temperature. The coexistence of ferroelectricity and ferromagnetism in 2D Cr2S3/WS2vertical heterostructures provides a cornerstone for the further design of logic-in-memory devices to build new computing architectures.

Defect passivation of the perovskite surface and grain boundary (GBs) has become a widely adopted approach to reduce charge recombination. Research has demonstrated that functional groups with Lewis acid or base properties can successfully neutralize trap states and limit nonradiative recombination. Unlike traditional Lewis acid–base organic molecules that only bind to a single anionic or cationic defect, zwitterions can passivate both anionic and cationic defects simultaneously. In this work, zwitterions organic halide salt 1-amino pyridine iodine (AmPyI) is used as a perovskite for defect passivation. It is found that a pair of amino lone electrons in AmPyI can passivate defects surface and GBs through hydrogen bonding with perovskite, and the introduced I–can bind to uncoordinated Pb2+while also controlling the surface morphology of the film and improving the crystallinity. In the presence of the AmPyI additive, we obtained about 1.24 μm of amplified perovskite grains and achieved an efficiency of 23.80% with minimal hysteresis.

A reliable constitutive model for copper is important for simulating the thermomechanical behavior of copper through glass via (TGV) in the glass interposer. This study presents a time-hardening model for the electroplated copper TGV. The material constants of copper in this model are evaluated by optimizing the experimental and numerical simulation results. In the experiment, the in-plane displacement of the glass was measured using 2-D digital image correlation (DIC). The four material constants in the time hardening model (THM) were adjusted to ensure good agreement between the simulation results and the experimental results. This optimized THM can be applied to copper TGVs over a wide range of temperatures (25 °C–400 °C) and temperature ramp rates (4–50 °C/min).

We demonstrate an all-fiber adaptive spatial control system with a mode selective photonic lantern as the core device to generate orbital angular momentum (OAM) modes. A 3 × 1 mode selective photonic lantern has been designed and fabricated, which can easily guide OAM modes. The stochastic parallel gradient descent (SPGD) algorithm is used to control the phase of each input channel. A stable OAM01 mode with a mode purity of 0.98 is obtained in a 30/130 μm fiber, and a 50W stable quasi-OAM01 mode beam is achieved after power scaling in a 42/250 μm output fiber. This system cannot only compensate the atmosphere turbulence effects on transmission distortion, but also be improved to generate switchable OAM modes with different topological charges, which provides great possibility of application in practical communication system.

Infrared camouflage is an effective technique to avoid many kinds of target detection by detectors in the infrared band. For a high-temperature environment, thermal management of selective emission is crucial to dissipate heat in the mid-infrared non-atmospheric window (5–8 μm). However, it still remains challenges for balancing infrared camouflage and thermal management. Here, we experimentally demonstrate a multilayer film structure (MFS) for infrared camouflage with thermal management. Combining the ideal emission spectrum and genetic algorithm (GA), the inverse-design MFS containing 7 layers of five materials (SiO2, Ge, ZnS, Pt and Au) has been designed. Based on the hierarchical metamaterial, the optimized MFS has high performance of infrared camouflage to against the lidar detection in the near-infrared band. The experimental results reveal the high compatible efficiency among thermal camouflage (ε3–5μm= 0.21, ε8–14μm= 0.16), laser stealth (ε1.06μm= 0.64, ε1.55μm= 0.90, ε10.6μm= 0.76) and thermal management (ε5–8μm= 0.54). Therefore, the proposed MFSs are attractive as basic building block of selective emitter, for the application of advanced photonics such as radiative cooling, infrared camouflage, and thermal emission.

Two-dimensional (2D) nanosheet arrays with unidirectional orientations are of great significance for synthesizing wafer-scale single crystals. Although great efforts have been devoted, the growth of atomically thin magnetic nanosheet arrays and single crystals is still unaddressed. Here we design an interisland-distance-mediated chemical vapor deposition strategy to synthesize centimeter-scale atomically thin Fe3O4arrays with unidirectional orientations on mica. The unidirectional alignment of nearly all the Fe3O4nanosheets is driven by a dual-coupling-guided growth mechanism. The Fe3O4/mica interlayer interaction induces two preferred antiparallel orientations, whereas the interisland interaction of Fe3O4breaks the energy degeneracy of antiparallel orientations. The room-temperature long-range ferrimagnetic order and thickness-tunable magnetic domain evolution are uncovered in atomically thin Fe3O4. This strategy to tune the orientations of nanosheets through the an interisland interaction can guide the synthesis of other 2D transition-metal oxides, thereby laying a solid foundation for future spintronic device applications at the integration level.

Sequential deposition is a promising tactic for perovskite film fabrication. However, the highly crystalline and compact morphology of PbI2film will hinder the quality and reproducibility of perovskite films. Here, nicotinamide (NTM) derivatives were introduced as simple and effective multifunctional ligands into the PbI2precursor solution. Orientation-controlled and mesoporous PbI2scaffolds formed due to strong chemical interaction and accelerated solvent volatilization. Nanobelt PbI2crystals were also generated at the grain boundaries of perovskite films with NTM derivatives, which can passivate the defects and enhance the carrier lifetime. As a result, the perovskite solar cells based on 6-(trifluoromethyl) nicotinamide-modulated films showed an enhanced power conversion efficiency of 22.7%, of which 98.8% was maintained even after 2000 h of aging. Our findings offer a distinctive understanding of regulating the crystallization of PbI2films and manipulating excess PbI2structure for efficient perovskite solar cells.

This article proposes a computational fluid dynamics (CFD)-based machine learning (ML) model to set the temperature of a convection reflow oven and control conveyor speed. Due to the thermal mass variation of printed circuit boards (PCBs) and surface mount components, the reflow recipe should be specified for each PCB assembly individually. Instead of relying on process engineers’ skills and experience, the ML model supported by heat transfer mechanisms provides a clear and logical path in the reflow recipe setup. An ideal recipe should let the largest component reach the minimum reflow temperature; meanwhile, the temperature cannot damage the small or heat-sensitive components. To simulate the reflow soldering process, the CFD model was used after being validated with experiment results. A system was programmed to feed the output of the CFD model as the input to the ML model. Benefiting from the interpolation and fast response brought by ML models, we can rapidly obtain the results subjected to millions of recipes, which are the combination of preset temperatures of all the heating zones and the conveyor speed in the oven. Using a weighting filter function, the optimal recipe can be obtained. This methodology is especially beneficial to reflowing smaller batches of complex PCB assemblies with a big heat capacity.

Tactile sensation is one of the critical ways humans perceive the world and is fundamental for the interaction with the surroundings. The development of haptic sensors can enable us to extend and transcend the human sense of touch to perceive the world more subtly. Inspired by the ingenious biological structure and the tactile sensing mechanism of the finger skin, we propose a biomimetic optical skin (BOS) based on optical microfiber coupler neuron (OMCN) in this paper, which realizes the multimodal tactile perception for the first time. Benefiting from the combination of the biomimetic structure that mimics the characteristics of the skin and the OMCN imitates the neuron which has the capability of multi-parameter sensing with high sensitivity, the sensing versatility of BOS is experimentally proven in that it can sensitively detect the temperature, contact force, and vibration, as well as the recognition of the hardness and roughness of the objects through the tactile-sensing manner of the human-like behavior. Besides, the excellent repeatability and stability of the BOS are investigated, which lays the foundation for practical applications. The proposed BOS can achieve the digitization of tactile perception and provide a new solution to the evolution of human-machine interaction and advanced robots.

Based on the novel concept of a fully-digitized module, we employ a forward-designed-assisted inverse design method to design a nonvolatile reconfigurable mode generator and an optical circulator, assisted with a phase change material. The mode generator can selectively output different modes. The fundamental transverse electric (TE0) or TE1 modes can be selectively generated when the TE0 mode is launched in the input port. The mode generator with an effective footprint of 2.4 μm × 16 μm exhibits the simulated insertion losses of less than 1.0 dB and the simulated crosstalks of lower than –19.0 dB for both the TE0 and TE1 modes from 1540 nm to 1560 nm. The optical circulator enables the light unidirectional propagation. Photons can be precisely routed from each input port to one adjacent output port in clockwise or counterclockwise directions. The simulated results indicate that the circulator with an effective footprint of 24 μm × 24 μm, can provide both the simulated insertion losses of less than 0.8 dB and the simulated crosstalks of lower than –16.3 dB from 1540 nm to 1560 nm in both clockwise and counterclockwise directions. The fabrication tolerances caused by the expansion or contraction of the etched pattern contour are also investigated. In principle, the proposed frameworks can be extended to an arbitrary number of ports for designing mode generators and optical circulators.

Human tactile perception involves the activation of mechanoreceptors located within the skin in response to external stimuli, along with the organization and processing within the brain. However, human sensations may be subject to the issues related to some physiological factors (such as skin injury or neurasthenia), resulting in inability to quantify tactile information. To address this challenge, a novel bio‐inspired artificial tactile (BAT) sensing system enabled by the integration of optical microfiber (OM) with full‐connected neural network (FCNN) in this paper is demonstrated, inspired by human physiological characteristics and tactile mechanisms. In this system, the BAT sensor mimics human skin, where the OM serves as the mechanoreceptor for sensing tactile stimuli, while the FCNN functions as a simulated human brain to train and extract the signal characteristics for intelligent object recognition. The experimental results indicate that the proposed BAT sensor can sensitively respond to both the contact force (static tactile stimuli), as well as the vibrotactile events (dynamic tactile stimuli) for the recognition of regular textures. Furthermore, by integrating the trained FCNN, the BAT sensing system accurately identifies various intricate surface textures with an exceptional accuracy of 95.7%, highlighting its potential in next‐generation human‐machine interaction and advanced robotics. Inspired by human tactual mechanism, a bio‐inspired artificial tactile (BAT) sensing system is presented, which consists of the BAT sensor and the full‐connected neural network (FCNN). BAT sensor mimics the human skin for sensing tactile stimuli with the highest sensitivity of −7.11 V N−1, and FCNN functions as the simulated human brain for intelligent tactile perception with an identification accuracy of 95.7%.

In this Letter, we propose collective topological corner modes in all-dielectric photonic crystal (PhC) supercell arrays, where each supercell is a second-order topological insulator. We show that coupled multipole corner modes are embedded in surrounding bulk modes at the Γ point even without the band gap, and individual or superposed dipole corner modes are selectively excited with collective behaviors by incident plane waves. These collective modes possess high-quality factors with an optimized thickness of the slab, and multipole decomposition reveals they are dominated by toroidal dipole and magnetic quadrupoles. Finally, we shrink the nontrivial region in each supercell to one unit-cell limit, where we show that collective corner modes still exist. Potential large-area topological applications are also discussed.

Better understanding and control of residual stress in the chip build-up layer are becoming more and more important for the assembly process. To estimate the chip warpage and characterize the residual stress, different methods are proposed. However, most of them have high cost or some limitations for the upper build-up material. In this study, an innovative method is proposed to characterize the residual stress and predict the chip warpage behavior of different size chips at different temperatures. The method combines experimental inspection of chip warpage and finite element analysis. By reducing the silicon die thickness, the influence of residual stress in the build-up layer can be amplified. The residual stress can be obtained by inspecting the increased warpage when the silicon dies are reduced to different thicknesses. Correlating the thermal increase warpages of thinner chips can help characterize the effective modulus and coefficient of thermal expansion (CTE) of the build-up layer. This study can help better understand the commonly classified build-up layer information. The results show good agreements between two types of samples under the same upstream process flow.

As surface mount components shrink in size, smaller apertures on stencils during solder paste printing can lead to uneven solder volume on a single resistor. This can result in the formation of irregular solder shapes, which are often deemed acceptable criterion depending on assembly house. However, such irregularities can potentially introduce variations in the fatigue life of the surface mount component. This study employs experimental and numerical approaches to investigate the reliability of differently shaped SAC305 solder joints on a single chip resistor. Four distinct solder shapes, concave, straight, tiny convex, and convex, are generated using varying volumes of solder paste controlled by uniquely designed apertures on a stencil. Eight pairs of differently shaped solder joints are assembled to hold a chip resistor in place. The test assembly involves R1005 and R0402 soldered with SAC305 and undergoes thermal shock cycling. As a single chip resistor assembly consists of two solder joints connecting termination and pads, the effect of solder volume difference between two solder joints are investigated. The fatigue life corresponds to decrease as the solder volume difference increase as 40%, 80%, and 120%. Conversely, total volume of two solder joints in a single chip resistor increases in scenarios with the same volume difference between two solder joints. Experimental data and finite element analysis lead to a new set of Darveaux's constants specific to this assembly. This study provides guideline to control the solder paste volumes in relation to fatigue life and enables numerical solution using a new Darveaux's constants.

Lhasa is located on the Qinghai–Tibet Plateau, with an altitude of 3,650 m, and a unique geography. Its climate is dry and cold all year round. Forensic entomological studies of the region are scarce. In this study, the diversity and seasonality of necrophagous flies in eight counties among Lhasa region were determined, and succession of necrophagous flies colonizing on rabbits in the Chengguan area of Lhasa was studied, so as to provide reference data for estimating postmortem interval (PMI) and location of death. In total, 22 species of necrophagous flies, belonging to six families were identified in Lhasa. Protophormia terraenovae(Robineau-Desvoidy, 1830) (Diptera: Calliphoridae) was the dominant species throughout the year, the diversity index (4.5834) indicated that the study on necrophagous flies in the Lhasa region is representative.

Gradient-based optimization combined with the adjoint method has been demonstrated to be an efficient way to design a nano-structure with a vast number of degrees of freedom. However, most inverse-designed photonic devices are applied as linear photonic devices. Here, we demonstrate the nonlinear optical response in inverse-designed integrated splitters fabricated on a SiN platform. The splitting ratio is tunable under different incident powers. The thermo-optical effect can be used as an effective approach for adjusting the nonlinear optical response threshold and modulation depth of the device. These promising results indicate the great potential of inverse-designed photonic devices in nonlinear optics and optical communications.

Waveguide taper, a key component in the photonic integrated circuit (PIC), enables on-chip mode conversion, but large-footprint tapers are detrimental to the PIC, which desires compact and efficient devices. Polarization sensitivity also limits the tapers in the applications involving orthogonal modes. In this work, we design an efficient polarization-insensitive ultra-short MMI-based waveguide taper, through the mode spreading principle and the self-image principle. The proposed taper is 26.3 µm long, one order of magnitude shorter than the standard linear taper. We fabricate the taper, and experimentally demonstrate that it exhibits a high transmission efficiency of ∼70% and a wide 1 dB bandwidth of >54nm, for both TE and TM polarizations.

At present, the power conversion efficiency (PCE) of perovskite solar cells (PSCs) has reached 26.1%. Polycrystalline perovskite films prepared by sequential deposition are often accompanied by excess PbI2. Although excess PbI2can reduce the internal defects of the perovskites and promote charge transfer, excess PbI2is unevenly distributed in the perovskites and easily decomposed into the composite center of charge. Therefore, the growth and distribution of PbI2crystals can be regulated by introducing 4-fluoroaniline (4-FLA) as an additive into the precursor of PbI2. We observe that the presence of an amino group in 4-FLA leads to a reduction in the strength of van der Waals forces between PbI2layer structures, thereby facilitating the uniform dispersion of excess PbI2within the perovskites. Additionally, 4-FLA is restricted from being embedded in the PbI2layer due to the steric hindrance of 4-FLA and the hydrogen bond interaction between nitrogen atoms and PbI2. Therefore, it leads to better dispersion of PbI2, resulting in better passivation and device efficiency. Based on the hydrophobicity of the benzene ring, the modified perovskite film shows excellent hydrophobicity. Ultimately, we achieved 21.63% PCE and 1.16V VOC. This provides an effective strategy for regulating excess PbI2to achieve efficient and stable PSCs.

Soil nitrogen cycling is one of the most critical biogeochemical cycles, and nitrogen-cycling-related microorganisms are the primary driving force behind nitrogen cycling in natural environments. The large karst sinkholes in China, known as tiankengs, harbor abundant unique biological resources due to their particular environmental conditions. However, nitrogen-cycling-related microorganisms in tiankeng soils and their connection to ecosystem processes remain poorly studied. We focused on Luohun Cave Tiankeng in Guizhou, China, in this study, utilizing high-throughput sequencing and other techniques to investigate the distribution patterns and genomic diversity of nitrogen-cycling-related microorganisms both inside and outside the tiankeng. The results indicated that the diversity and abundance of denitrifying bacteria, ammonia-oxidizing bacteria, and ammonia-oxidizing archaea communities within the tiankeng are higher than the corresponding characteristics outside the tiankeng area. However, the microbial network relationships were more fragile inside the tiankeng than outside. The most abundant species of denitrifying bacteria, ammonia-oxidizing bacteria and ammonia-oxidizing archaea within the tiankeng area were unclassified_p_Proteobacteria (47.8%), unclassified_k_norank (37.3%), and unclassified_g_norank_f_norank_o_norank_c_environmental_samples (55.7%), respectively. Outside the tiankeng, they were unclassified_k_norank_d_bacteria (54.5%), unclassified_k_norank (48.1%), and unclassified_k_norank (49.6%), respectively. Additionally, the nitrogen content within the tiankeng was significantly lower under the influence of these nitrogen-related microorganisms (P< 0.05), whereas the nutrient content was higher than that outside the tiankeng. To the best of our knowledge, this is the first report on the crucial microbial distribution patterns driving nitrogen cycling in karst tiankengs and provides new insights into the structure and potential functions of N-cycling-related microorganisms in the unique ecological environment of tiankeng ecosystems.

The two-step sequential deposition strategy has been widely recognized in promoting the research and application of perovskite solar cells, but the rapid reaction of organic salts with lead iodide inevitably affects the growth of perovskite crystals, accompanied by the generation of more defects. In this study, the regulation of crystal growth was achieved in a two-step deposition method by mixing 1-naphthylmethylammonium bromide (NMABr) with organic salts. The results show that the addition of NMABr effectively delays the aggregation and crystallization behavior of organic salts; thereby, the growth of the optimal crystal (001) orientation of perovskite is promoted. Based on this phenomenon of delaying the crystallization process of perovskite, the “slow-release effect assisted crystallization” is defined. Moreover, the incorporation of the Br element expands the band gap of perovskite and mitigates material defects as nonradiative recombination centers. Consequently, the power conversion efficiency (PCE) of the enhanced perovskite solar cells (PSCs) reaches 20.20%. It is noteworthy that the hydrophobic nature of the naphthalene moiety in NMABr can enhance the humidity resistance of PSCs, and the perovskite phase does not decompose for more than 3000 h (30–40% RH), enabling it to retain 90% of its initial efficiency even after exposure to a nitrogen environment for 1200 h.

Convergent morphological evolution is widespread in flowering plants, and understanding this phenomenon relies on well-resolved phylogenies. Nuclear phylogenetic reconstruction using transcriptome datasets has been successful in various angiosperm groups, but it is limited to taxa with available fresh materials. Asteraceae, which are one of the two largest angiosperm families and are important for both ecosystems and human livelihood, show multiple examples of convergent evolution. Nuclear Asteraceae phylogenies have resolved relationships among most subfamilies and many tribes, but many phylogenetic and evolutionary questions regarding subtribes and genera remain, owing to limited sampling. Here, we increased the sampling for Asteraceae phylogenetic reconstruction using transcriptomes and genome-skimming datasets and produced nuclear phylogenetic trees with 706 species representing two-thirds of recognized subtribes. Ancestral character reconstruction supports multiple convergent evolutionary events in Asteraceae, with gains and losses of bilateral floral symmetry correlated with diversification of some subfamilies and smaller groups, respectively. Presence of the calyx-related pappus may have been especially important for the success of some subtribes and genera. Molecular evolutionary analyses support the likely contribution of duplications of MADS-box and TCP floral regulatory genes to innovations in floral morphology, including capitulum inflorescences and bilaterally symmetric flowers, potentially promoting the diversification of Asteraceae. Subsequent divergences and reductions in CYC2gene expression are related to the gain and loss of zygomorphic flowers. This phylogenomic work with greater taxon sampling through inclusion of genome-skimming datasets reveals the feasibility of expanded evolutionary analyses using DNA samples for understanding convergent evolution.

The metal–nitrogen–carbon (M–N–C)-based catalysts are promising to replace PGM (platinum group metal) to accelerate oxygen reduction reaction due to their excellent electrocatalytic performance. However, the inferior intrinsic activity and poor active site density confining further improvement in their performance. Modulating the electronic structure and reasonably designing the pore structure are widely acknowledged effective strategies to boost the activity of the M–N–C catalysts. However, it is a great challenge to form abundant pores to regulate the electronic structure via the facile method. Herein, a hierarchical, porous dual-atom catalyst FeNi-NPC-1000 has been architectured by the Na2CO3template method and bimetallic doping modification strategy. Benefitting from the optimized pore and electronic structure, the as-prepared FeNi-NPC-1000 possesses a high specific surface area (1412.8 m2g–1) and improved ORR activity (E1/2= 0.877 V vs RHE), which is superior to that of Pt/C (E1/2= 0.867 V vs RHE). With the evidence of AC-STEM, XAS, and DFT, the FeNi-N8-C moiety is proven to be the key active site to realize high-efficiency ORR catalysis. When assembled it as an air cathode of ZABs, FeNi-NPC-1000 displays superior discharge performance (Pmax= 367.1 mW cm–2) and a stable battery long-life. This article will provide a new strategy for designing dual-metal atomic catalysts applied in metal–air batteries.

Nanophotonic devices with high densities are extremely attractive because they can potentially merge photonics and electronics at the nanoscale. However, traditional integrated photonic circuits are designed primarily by manually selecting parameters or employing semi-analytical models. Limited by the small parameter search space, the designed nanophotonic devices generally have a single function, and the footprints reach hundreds of microns. Recently, novel ultra-compact nanophotonic devices with digital structures were proposed. By applying inverse design algorithms, which can search the full parameter space, the proposed devices show extremely compact footprints of a few microns. The results from many groups imply that digital nanophotonics can achieve not only ultra-compact single-function devices but also miniaturized multi-function devices and complex functions such as artificial intelligence operations at the nanoscale. Furthermore, to balance the performance and fabrication tolerances of such devices, researchers have developed various solutions, such as adding regularization constraints to digital structures. We believe that with the rapid development of inverse design algorithms and continuous improvements to the nanofabrication process, digital nanophotonics will play a key role in promoting the performance of nanophotonic integration. In this review, we uncover the exciting developments and challenges in this field, analyse and explore potential solutions to these challenges and provide comments on future directions in this field.

Long noncoding RNA (lncRNA) testis-specific transcript, Y-linked 15 (TTTY15) plays an important regulatory role in prostate cancer, but its role in esophageal squamous cell carcinoma (ESCC) remains unclear. This study aimed to explore the expression pattern, biological function and underlying mechanism of TTTY15 in ESCC. Quantitative real-time PCR (qRT-PCR) was used to detect the expression of TTTY15 and microRNA (miR)-337-3p in ESCC tissues and cell lines. Cell counting kit-8 method was used to detect the proliferation of ESCC cells. Transwell method was used to determine the migration and invasion of ESCC cells. Luciferase reporter assay was used to verify the interaction between TTTY15 and miR-337-3p. Western blot was used to analyze the effects of TTTY15 and miR-337-3p on Janus kinase 2 (JAK2) expression. In the present study, we demonstrated that the expression level of TTTY15 was significantly upregulated in ESCC tissues, while the expression of miR-337-3p was downregulated. In ESCC samples, the expression levels of TTTY15 and miR-337-3p were negatively correlated. TTTY15 knockdown could significantly reduce the proliferation, migration and invasion of ESCC cells, and miR-337-3p mimics had similar effects. In addition, overexpression of TTTY15 inhibited miR-337-3p by binding with it. TTTY15 could indirectly modulate JAK2, and overexpression of TTTY15 could reverse the inhibitory effects of miR-337-3p on malignant phenotypes of ESCC cells. In conclusion, TTTY15 plays an oncogenic role in ESCC by targeting miR-337-3p/JAK2 axis.

Mode division multiplexing (MDM) technology has been well known to researchers for its ability to increase the link capacity of photonic network. While various mode processing devices were demonstrated in recent years, the reconfigurability of multi-mode processing devices, which is vital for large-scale multi-functional networks, is rarely developed. In this paper, we first propose and experimentally demonstrate a scalable mode-selective converter using asymmetrical micro-racetrack resonators (MRRs) for optical network-on-chip. The proposed device, composed of cascaded MRRs, is able to convert the input monochromatic light to an arbitrary supported mode in the output waveguide as required. Thermo-optical effect of silicon waveguides is adopted to tune the working states of the device. To test the utility, a device for proof-of-concept is fabricated and experimentally demonstrated based on silicon-on-insulator substrate. The measured spectra of the device show that the extinction ratios of MRRs are larger than 18 dB, and modal crosstalk for selected modes are all less than −16.5 dB. The switching time of the fabricated device is in the level of about 40 μs. The proposed device is believed to have potential applications in multi-functional and intelligent network-on-chip, especially in reconfigurable MDM networks.

Adiabatic waveguide taper and on-chip wavelength demultiplexer are the key components of photonic integrated circuits. However, these two kinds of devices which were designed by the traditional semi-analytic methods or the brute-force search methods usually have large size. Here, based on the regularized digital metamaterials, a two-channel focused wavelength demultiplexer with a footprint of 2.4 × 10 μm2has been proposed. The designed demultiplexer can directly connect to a grating coupler under the absence of a long adiabatic waveguide taper. The objective first method and the modified steepest descent method are used to design the demultiplexer which splits 1520 nm and 1580 nm light. Experimental results show that the insertion loss of the upper (lower) channel of the demultiplexer is −1.77 dB (−2.10 dB) and the crosstalk is −25.17 dB (−12.14 dB). Besides, the simulation results indicate that the fabrication tolerance of the device can reach ±20 nm in etching depth and ±10 nm in plane size changing. Benefitted from the extensibility of the design method, other types of ultra-compact “focused” devices, like mode splitters, mode converters, and power splitters can also be designed. Most importantly, this design method can be used to design devices with more complicated functionalities, such as multi-channel focused wavelength demultiplexers.

Graphical Abstract:

We numerically propose a hybrid metasurface (MS) to realize all-optical switch and logic gates in the shortwave infrared (SWIR) band. Such MS consists of one silicon rod and one Ge_2Sb_2Te_5 (GST) rod pair. Utilizing the transition from an amorphous state to a crystalline state of GST, such MS can produce an electromagnetically induced transparency (EIT) analogue with active control. Based on this, we realize all-optical switching at 1770 nm with a modulation depth of 84%. Besides, three different logic gates, NOT, NOR and OR, can also be achieved in this metadevice simultaneously. Thanks to the reversible and fast phase transition process of GST, this device possesses reconfigurable ability as well as fast response time, and has potential applications in future optical networks.

A band-stop filter with high resolving power is designed for mid-infrared spectroscopic sensing and imaging applications. By utilizing a truncated grating consisting of multiple gold nanowires in each unit cell of the periodic structure, compression of the stop bandwidth and improvement of the resonance extinction are realized simultaneously. It shows only a single stop band at ∼4.474  μm with 15 dB extinction and >80% background transmission over a wide spectral range. The obtained narrow linewidth (∼1.45  nm) enables a spectral resolving power higher than 3000. Flexible control of the filtering performance is investigated by adjusting the variety of geometrical parameters. Moreover, the structure may have potential applications in refractive index sensing.

Independent manipulation of phase and polarization of optical fields is of great interest in various applications, including vector-field generation, optical tweezers, and nanolithography. The integration of phase and polarization manipulation on a single optical device may greatly simplify optical systems and eases optical alignment. In this Letter, a family of reflective cross-shaped quarter-wave birefringent metasurfaces is proposed to achieve full control of polarization and phase of reflected waves. Based on the proposed metasurfaces, two meta-mirrors are designed with integrated functions of polarization conversion and sub-diffraction focusing. Numerical investigations also reveal the achromatic focusing performance of the two meta-mirrors. The proposed metasurfaces with independent manipulation of polarization and phase provide flexible building blocks for constructing complicated vector optical fields.

With the magnetron-sputtering deposition method, α phase indium selenide (α-In_2Se_3) was developed into a saturable absorber (SA) with wideband saturable absorption property at 800, 1560, and 1930 nm. After inserting the α-In_2Se_3 SA into erbium-doped fiber laser (EDFL) and thulium-doped fiber laser (TDFL) systems, we can easily obtain stable soliton pulse trains. The pulse duration/pulse energy/slope efficiency for EDFL and TDFL were 276 fs/2.03 nJ/15.8% and 1.02 ps/7.1 nJ/23.5%, respectively. These results showed that the MSD-grown α-In_2Se_3 could be regarded as high efficiency material to be applied in ultrafast photonics.

Recently, microRNAs (miRNAs) have been suggested to play important roles in the pathophysiology of type 2 diabetes mellitus (T2DM). In this study, we explored the role of miR-486-5p in T2DM. MiR-486-5p was significantly downregulated in the serum of T2DM patients when compared to that of healthy volunteers, and miR-486-5p expression level was negative correlated with blood glucose levels of T2DM patients. Overexpression of miR-486-5p promoted cell proliferation, enhanced insulin secretion and inhibited cell apoptosis of pancreatic β-cell line (INS-1 cells). On the other hand, knockdown of miR-486-5p had the opposite effects in INS-1 cells. The bio-informatics analysis by using TargetScan revealed phosphatase and tensin homolog (PTEN) and Forkhead Box O1 (FOXO1) were downstream targets of miR-486-5p, and the interaction between miR-486-5p and PTEN (or FOXO1) was validated by luciferase reporter assay. In addition, miR-486-5p negatively regulated the mRNA and protein expression of PTEN and FOXO1. Overexpression of PTEN (or FOXO1) suppressed insulin secretion in glucose stimulation, inhibited cell proliferation, and induced cell apoptosis, and partially abolished the effects of miR-486-5p overexpression on insulin secretion, cell proliferation and cell apoptosis of INS-1 cells. In conclusion, our results revealed that miR-486-5p promoted pancreatic cell proliferation, increased insulin sensitivity and inhibited apoptosis by targeting PTEN and FOXO1.

This paper presents a sheet of graphene-ribbon waveguide as a simple and ultra-compact splitter and filter in the mid-infrared waveband. The central wavelength of the graphene surface plasmons (GSPs) and the coupling intensity of this splitter can be tuned by changing the physical parameters, such as the chemical potential, the width of the waveguide, the gap between neighboring graphene ribbons, the refractive index of the substrate, the carrier relaxation time, etc. The effects of these parameters on GSP waves and beam-splitter specifications are numerically depicted based on the finite-difference time-domain method. This proposed structure can be used to construct an ultra-compact fast-tunable beam splitter, filter, modulator, and switch in the mid-infrared range.

A strategy to fabricate an ambipolar near-infrared vertical photodetector (VPD) by sandwiching a photoactive material as a channel film between the bottom graphene and top metal electrodes was developed. The channel length in the vertical architecture was determined by the channel layer thickness, which can provide an ultrashort channel length without the need for a high-precision manufacturing process. The performance of VPDs with two types of semiconductor layers, a graphene–PbS quantum dot hybrid (GQDH) and PbS quantum dots (QDs), was measured. The GQDH VPD showed better photoelectric properties than the QD VPD because of the high mobility of graphene doped in the channel. The GQDH VPD exhibited excellent photoresponse properties with a responsivity of 1.6 × 104A/W in the p-type regime and a fast response speed with a rise time of 8 ms. The simple manufacture and the promising photoresponse of the GQDH VPDs reveal that an easy and effective way to fabricate high-performance ambipolar photodetectors was developed.