Mesoporous TiO2 Single-Crystal Particles from Controlled Crystallization-Driven Mono-Micelle Assembly as an Efficient Photocatalyst.

Mesoporous materials with crystalline frameworks have been widely explored in many fields due to their unique structure and crystalline feature, but accurate manipulations over crystalline scaffolds, mainly composed of uncontrolled polymorphs, are still lacking. Herein, we explored a controlled crystallization-driven monomicelle assembly approach to construct a type of uniform mesoporous TiO2 particles with atomically aligned single-crystal frameworks. The resultant mesoporous TiO2 single-crystal particles possess an angular shape ∼80 nm in diameter, good mesoporosity (a high surface area of 112 m2 g-1 and a mean pore size at 8.3 nm), and highly oriented anatase frameworks. By adjusting the evaporation rate during assembly, such a facile solution-processed strategy further enables the regulation of the particle size and mesopore size without the destruction of the oriented crystallites. Such a combination of ordered mesoporosity and crystalline orientation provides both effective mass and charge transportation, leading to a significant increase in the hydrogen generation rate. A maximum hydrogen evolution rate of 12.5 mmol g-1 h-1 can be realized, along with great stability under solar light. Our study is envisaged to extend the possibility of mesoporous single crystal growth to a range of functional ceramics and semiconductors toward advanced applications.

Boosted Oxygen Kinetics of Hierarchically Mesoporous Mo2C/C for High-current-density Zn-air Battery.

The high-current-density Zn-air battery shows big prospects in next-generation energy technologies, while sluggish O2 reaction and diffusion kinetics barricade the applications. Herein, the sequential assembly is innovatively demonstrated for hierarchically mesoporous molybdenum carbides/carbon microspheres with a tunable thickness of mesoporous carbon layers (Meso-Mo2C/C-x, where x represents the thickness). The optimum Meso-Mo2C/C-14 composites (≈2 µm in diameter) are composed of mesoporous nanosheets (≈38 nm in thickness), which possess bilateral mesoporous carbon layers (≈14 nm in thickness), inner Mo2C/C layers (≈8 nm in thickness) with orthorhombic Mo2C nanoparticles (≈2 nm in diameter), a high surface area of ≈426 m2 g-1, and open mesopores (≈6.9 nm in size). Experiments and calculations corroborate the hierarchically mesoporous Mo2C/C can enhance hydrophilicity for supplying sufficient O2, accelerate oxygen reduction kinetics by highly-active Mo2C and N-doped carbon sites, and facilitate O2 diffusion kinetics over hierarchically mesopores. Therefore, Meso-Mo2C/C-14 outputs a high half-wave potential (0.88 V vs RHE) with a low Tafel slope (51 mV dec-1) for oxygen reduction. More significantly, the Zn-air battery delivers an ultrahigh power density (272 mW cm-2), and an unprecedented 100 h stability at a high-current-density condition (100 mA cm-2), which is one of the best performances.

Synergistic Catalytic Performance of Pt-Au Bimetallic Catalysts on High-Crystallinity ZSM-23 Zeolite for Hexadecane Hydroisomerization: Metal-Acid Balance and Enhanced Isomerization Selectivity.

Highly crystalline ZSM-23 zeolite, exhibiting a distinctive dumbbell morphology, was synthesized via a hydrothermal method. Bifunctional catalysts, comprising single metals (Pt or Au) and bimetals (Pt-Au), were successfully prepared by using a positional precipitation method. The hydroisomerization of hexadecane served as a model reaction to assess the catalytic performance arising from the synergistic effects of bimetallic active sites. In comparison to single-metal catalysts, 0.3Au0.7Pt/ZSM-23 demonstrated increased n-C16 conversion, while 0.5Au0.5Pt/ZSM-23 exhibited enhanced i-C16 selectivity, achieving the highest i-C16 yield. The bimetallic catalyst not only finely tuned the metal site activity through bimetallic synergy but also achieved a superior balance between metal and acid catalysis, resulting in improved catalytic performance in the n-C16 hydroisomerization. The Pt-Au bimetallic catalyst approached the ideal requirements for a hydroisomerization catalyst, achieving a harmonious balance of metal and acid catalysis.

Predicting Quercus gilva distribution dynamics and its response to climate change induced by GHGs emission through MaxEnt modeling.

Quercus gilva, an evergreen tree species in Quercus section Cyclobalanopsis, is an ecologically and economically valuable species in subtropical regions of East Asia. Predicting the impact of climate change on potential distribution of Q. gilva can provide a scientific basis for the conservation and utilization of its genetic resources, as well as for afforestation. In this study, 74 distribution records of Q. gilva and nine climate variables were obtained after data collection and processing. Current climate data downloaded from WorldClim and future climate data predicted by four future climate scenarios (2040s SSP1-2.6, 2040s SSP5-8.5, 2060s SSP1-2.6, and 2060s SSP5-8.5) mainly based on greenhouse gases emissions of distribution sites were used in MaxEnt model with optimized parameters to predict distribution dynamics of Q. gilva and its response to climate change. The results showed that the predicted current distribution was consistent with natural distribution of Q. gilva, which was mainly located in Hunan, Jiangxi, Zhejiang, Fujian, Guizhou, and Taiwan provinces of China, as well as Japan and Jeju Island of South Korea. Under current climate conditions, precipitation factors played a more significant role than temperature factors on distribution of Q. gilva, and precipitation of driest quarter (BIO17) is the most important restriction factor for its current distribution (contribution rate of 57.35%). Under future climate conditions, mean temperature of driest quarter (BIO9) was the essential climate factor affecting future change in potential distribution of Q. gilva. As the degree of climatic anomaly increased in the future, the total area of predicted distribution of Q. gilva showed a shrinking trend (decreased by 12.24%-45.21%) and Q. gilva would migrate to high altitudes and latitudes. The research results illustrated potential distribution range and suitable climate conditions of Q. gilva, which can provide essential theoretical references for the conservation, development, and utilization of Q. gilva and other related species.

Implanting Colloidal Nanoparticles into Single-Crystalline Zeolites for Catalytic Dehydration.

The encapsulation of functional colloidal nanoparticles (100 nm) into single-crystalline ZSM-5 zeolites, aiming to create uniform core-shell structures, is a highly sought-after yet formidable objective due to significant lattice mismatch and distinct crystallization properties. In this study, we demonstrate the fabrication of a core-shell structured single-crystal zeolite encompassing an Fe3O4 colloidal core via a novel confinement stepwise crystallization methodology. By engineering a confined nanocavity, anchoring nucleation sites, and executing stepwise crystallization, we have successfully encapsulated colloidal nanoparticles (CN) within single-crystal zeolites. These grafted sites, alongside the controlled crystallization process, compel the zeolite seed to nucleate and expand along the Fe3O4 colloidal nanoparticle surface, within a meticulously defined volume (1.5×107≤V≤1.3×108 nm3). Our strategy exhibits versatility and adaptability to an array of zeolites, including but not restricted to ZSM-5, NaA, ZSM-11, and TS-1 with polycrystalline zeolite shell. We highlight the uniformly structured magnetic-nucleus single-crystalline zeolite, which displays pronounced superparamagnetism (14 emu/g) and robust acidity (~0.83 mmol/g). This innovative material has been effectively utilized in a magnetically stabilized bed (MSB) reactor for the dehydration of ethanol, delivering an exceptional conversion rate (98 %), supreme ethylene selectivity (98 %), and superior catalytic endurance (in excess of 100 hours).

Anisotropic Self-Assembly of Asymmetric Mesoporous Hemispheres with Tunable Pore Structures at Liquid-Liquid Interfaces.

Asymmetric materials have attracted tremendous interest because of their intriguing physicochemical properties and promising applications, but endowing them with precisely controlled morphologies and porous structures remains a formidable challenge. Herein, a facile micelle anisotropic self-assembly approach on a droplet surface is demonstrated to fabricate asymmetric carbon hemispheres with a jellyfish-like shape and radial multilocular mesostructure. This facile synthesis follows an interface-energy-mediated nucleation and growth mechanism, which allows easy control of the micellar self-assembly behaviors from isotropic to anisotropic modes. Furthermore, the micelle structure can also be systematically manipulated by selecting different amphiphilic triblock copolymers as a template, resulting in diverse novel asymmetric nanostructures, including eggshell, lotus, jellyfish, and mushroom-shaped architectures. The unique jellyfish-like hemispheres possess large open mesopores (∼14 nm), a high surface area (∼684 m2 g-1), abundant nitrogen dopants (∼6.3 wt %), a core-shell mesostructure and, as a result, manifest excellent sodium-storage performance in both half and full-cell configurations. Overall, our approach provides new insights and inspirations for exploring sophisticated asymmetric nanostructures for many potential applications.

Constructing Unique Mesoporous Carbon Superstructures via Monomicelle Interface Confined Assembly.

Constructing hierarchical three-dimensional (3D) mesostructures with unique pore structure, controllable morphology, highly accessible surface area, and appealing functionality remains a great challenge in materials science. Here, we report a monomicelle interface confined assembly approach to fabricate an unprecedented type of 3D mesoporous N-doped carbon superstructure for the first time. In this hierarchical structure, a large hollow locates in the center (∼300 nm in diameter), and an ultrathin monolayer of spherical mesopores (∼22 nm) uniformly distributes on the hollow shells. Meanwhile, a small hole (4.0-4.5 nm) is also created on the interior surface of each small spherical mesopore, enabling the superstructure to be totally interconnected. Vitally, such interconnected porous supraparticles exhibit ultrahigh accessible surface area (685 m2 g-1) and good underwater aerophilicity due to the abundant spherical mesopores. Additionally, the number (70-150) of spherical mesopores, particle size (22 and 42 nm), and shell thickness (4.0-26 nm) of the supraparticles can all be accurately manipulated. Besides this spherical morphology, other configurations involving 3D hollow nanovesicles and 2D nanosheets were also obtained. Finally, we manifest the mesoporous carbon superstructure as an advanced electrocatalytic material with a half-wave potential of 0.82 V (vs RHE), equivalent to the value of the commercial Pt/C electrode, and notable durability for oxygen reduction reaction (ORR).

Streamlined Mesoporous Silica Nanoparticles with Tunable Curvature from Interfacial Dynamic-Migration Strategy for Nanomotors.

Streamlined architectures with a low fluid-resistance coefficient have been receiving great attention in various fields. However, it is still a great challenge to synthesize streamlined architecture with tunable surface curvature at the nanoscale. Herein, we report a facile interfacial dynamic migration strategy for the synthesis of streamlined mesoporous nanotadpoles with varied architectures. These tadpole-like nanoparticles possess a big streamlined head and a slender tail, which exhibit large inner cavities (75-170 nm), high surface areas (424-488 m2 g-1), and uniform mesopore sizes (2.4-3.2 nm). The head curvature of the streamlined mesoporous nanoparticles can be well-tuned from ∼2.96 × 10-2 to ∼5.56 × 10-2 nm-1, and the tail length can also be regulated from ∼30 to ∼650 nm. By selectively loading the Fe3O4 catalyst in the cavity of the streamlined silica nanotadpoles, the H2O2-driven mesoporous nanomotors were designed. The mesoporous nanomotors with optimized structural parameters exhibit outstanding directionality and a diffusion coefficient of 8.15 µm2 s-1.

Versatile Synthesis of Mesoporous Crystalline TiO2 Materials by Monomicelle Assembly.

Mesoscale TiO2 structures have realized many technological applications-ranging from catalysis and biomedicine to energy storage and conversion-because of their large mesoporosities offering desirable accessibility and mass transport. Tailoring mesoporous TiO2 structures with novel mesoscopic and microscopic configurations is envisaged to offer ample opportunities for further applications. In this Review, we explain how to synthesize novel mesoporous TiO2 materials and present recent examples. An emphasis is placed on a "monomicelle assembly" strategy as an emerging and powerful approach to direct the formation of mesostructured TiO2 with precise control over its structural orientations and architectures. Furthermore, typical examples of mesoporous TiO2 for applications in batteries and photocatalysis are highlighted. The Review ends with an outlook towards the synthesis of mesoporous TiO2 with tailored architectures by self-assembly, which could pave the way for developing advanced energy conversion and storage devices.

Precisely Designed Mesoscopic Titania for High-Volumetric-Density Pseudocapacitance.

Surface redox pseudocapacitance, which enables short charging times and high power delivery, is very attractive in a wide range of sites. To achieve maximized specific capacity, nanostructuring of active materials with high surface area is indispensable. However, one key limitation for capacitive materials is their low volumetric capacity due to the low tap density of nanomaterials. Here, we present a promising mesoscale TiO2 structure with precisely controlled mesoporous frameworks as a high-density pseudocapacitive model system. The dense-packed mesoscopic TiO2 in micrometer size offers a high accessible surface area (124 m2 g-1) and radially aligned mesopore channels, but high tap density (1.7 g cm-3) that is much higher than TiO2 nanoparticles (0.47 g cm-3). As a pseudocapacitive sodium-ion storage anode, the precisely designed mesoscopic TiO2 model achieved maximized gravimetric capacity (240 mAh g-1) and volumetric capacity (350 mAh cm-3) at 0.025 A g-1. Such a designed pseudocapacitive mesostructure further realized a commercially comparable areal capacity (2.1 mAh cm-2) at a high mass loading of 9.47 mg cm-2. This mesostructured electrode that enables fast sodiation in dense nanostructures has implications for high-power applications, fast-charging devices, and pseudocapacitive electrode design.

Slow Breathing Exercise with Multimodal Virtual Reality: A Feasibility Study.

Many studies have shown that slow breathing training is beneficial for human health. However, several factors might discourage beginners from continuing their training. For example, a long training period is generally required for benefit realization, and there is no real-time feedback to trainees to adjust their breathing control strategy. To raise the user's interest in breathing exercise training, a virtual reality system with multimodal biofeedback is proposed in this work. In our system, a realistic human model of the trainee is provided in virtual reality (VR). At the same time, abdominal movements are sensed, and the breathing rate can be visualized. Being aware of the breathing rate, the trainee can regulate his or her breathing to achieve a slower breathing rate. An additional source of tactile feedback is combined with visual feedback to provide a more immersive experience for the trainees. Finally, the user's satisfaction with the proposed system is reported through questionnaires. Most of the users find it enjoyable to use such a system for mediation training.

Surface-Confined Winding Assembly of Mesoporous Nanorods.

Bending and folding are important stereoscopic geometry parameters of one-dimensional (1D) nanomaterials, yet the precise control of them has remained a great challenge. Herein, a surface-confined winding assembly strategy is demonstrated to regulate the stereoscopic architecture of uniform 1D mesoporous SiO2 (mSiO2) nanorods. Based on this brand-new strategy, the 1D mSiO2 nanorods can wind on the surface of 3D premade nanoparticles (sphere, cube, hexagon disk, spindle, rod, etc.) and inherit their surface topological structures. Therefore, the mSiO2 nanorods with a diameter of ∼50 nm and a variable length can be bent into arc shapes with variable radii and radians, as well as folded into 60, 90, 120, and 180° angular convex corners with controllable folding times. Additionally, in contrast to conventional core@shell structures, this winding structure induces partial exposure and accessibility of the premade nanoparticles. The functional nanoparticles can exhibit large accessible surface and efficient energy exchanges with the surroundings. As a proof of concept, winding-structured CuS&mSiO2 nanocomposites are fabricated, which are made up of a 100 nm CuS nanosphere and the 1D mSiO2 nanorods with a diameter of ∼50 nm winding the nanosphere in the perimeter. The winding structured nanocomposites are demonstrated to have fourfold photoacoustic imaging intensity compared with the conventional core@shell nanostructure with an inaccessible core because of the greatly enhanced photothermal conversion efficiency (increased by ∼30%). Overall, our work paves the way to the design and synthesis of 1D nanomaterials with controllable bending and folding, as well as the formation of high-performance complex nanocomposites.

Traditional Chinese Medicine Pulse Diagnosis on a Smartphone Using Skin Impedance at Acupoints: A Feasibility Study.

In traditional Chinese medicine (TCM), pulse diagnosis is one of the most important methods for diagnosis. A pulse can be felt by applying firm fingertip pressure to the skin where the arteries travel. The pulse diagnosis has become an important tool not only for TCM practitioners but also for several areas of Western medicine. Many pulse measuring devices have been proposed to obtain objective pulse conditions. In the past, pulse diagnosis instruments were single-point sensing methods, which missed a lot of information. Later, multi-point sensing instruments were developed that resolved this issue but were much higher in cost and lacked mobility. In this article, based on the concept of sensor fusion, we describe a portable low-cost system for TCM pulse-type estimation using a smartphone connected to two sensors, including one photoplethysmography (PPG) sensor and one galvanic skin response (GSR) sensor. As a proof of concept, we collected five-minute PPG pulse information and skin impedance on 24 acupoints from 80 subjects. Based on these collected data, we implemented a fully connected neural network (FCN), which was able to provide high prediction accuracy (>90%) for patients with a TCM wiry pulse.

Stable Ti3+ Defects in Oriented Mesoporous Titania Frameworks for Efficient Photocatalysis.

By introducing a compatible reducing agent (2-ethylimidazole) into a mono-micelle assembly process, we present a type of ordered mesoporous TiO2 microspheres that combines radially aligned mesostructure with Ti3+ defects in mesoporous frameworks. Such reductant acts as a building block of mesostructured frameworks and reduces Ti4+ in situ to generate defects during calcination, giving rise to the coexistence of bulk Ti3+ defects and an ordered mesostructure. The mesoporous TiO2 has both excellent mesoporosity (a high surface area of 106 m2 g-1 , a mean pore size of 18.4 nm) and stable defects with an extended photoresponse. Such integration of unique mesoscopic architecture and atomic vacancies provide both effective mass transportation and enhanced light utilization, leading to a remarkable increase in H2 generation rate. A maximum H2 evolution rate of 19.8 mmol g-1 h-1 can be achieved, along with outstanding stability under solar light.

Two-Dimensional Mesoporous Heterostructure Delivering Superior Pseudocapacitive Sodium Storage via Bottom-Up Monomicelle Assembly.

Two-dimensional (2D) heterostructures endowed with mesoporosities offer exciting opportunities in electrocatalysis, photocatalysis, energy storage, and conversion technologies due to their integrated functionalities, abundant active sites and shortened diffusion distance. However, layered mesostructures have not been combined due to the immense difficulties by conventional chemical, mechanical exfoliation or self-assembly approaches. Herein, we explore a bottom-up strategy, carried out under mild conditions, for the facile synthesis of monolayered mesoporous-titania-mesoporous-carbon vertical heterostructure with uniform mesopore size, which enables ultrahigh rate capability and cycling longevity for pseudocapacitive sodium-ion storage in nonaqueous electrolyte. Such a brand-new type of heterostructure consists of well-ordered monolayered mesoporous titania nanosheets and surrounding two mesoporous carbon monolayers assembled at both sides. Remarkably, the combination of interconnected large mesoporosity and heterointerface leads to highly promoted reversible pseudocapacitance (96.4% of total charge storage at a sweep rate of 1 mV s-1), and it enables the material to retain strong mechanical stability during the rapid sodiation and desodiation processes. This study reveals the importance of incorporating mesopores into heterointerface as a strategy for enhancing charge storage kinetics of electroactive materials.

Uniform Ordered Two-Dimensional Mesoporous TiO2 Nanosheets from Hydrothermal-Induced Solvent-Confined Monomicelle Assembly.

Two-dimensional (2D) nanomaterials have been the focus of substantial research interest recently owing to their fascinating and excellent properties. However, 2D porous materials have remained quite rare due to the difficulty of creating pores in 2D nanostructures. Here, we have synthesized a novel type of single-layered 2D mesoporous TiO2 nanosheets with very uniform size and thickness as well as ordered mesostructure from an unprecedented hydrothermal-induced solvent-confined assembly approach. The F127/TiO2 spherical monomicelles are first formed and redispersed in ethanol and glycerol, followed by a hydrothermal treatment to assemble these subunits into single-layered 2D mesostructure owing to the confinement effect of highly adhered glycerol solvent. The obtained 2D mesoporous TiO2 nanosheets have a relative mean size at around 500 × 500 nm and can be randomly stacked into a bulk. The TiO2 nanosheets possess only one layer of ordered mesopores with a pore size of 4.0 nm, a very high surface area of 210 m2 g-1 and a uniform thickness of 5.5 nm. The thickness can be further manipulated from 5.5 to 27.6 nm via simply tuning precursor concentration or solvent ratio. Due to the well-defined 2D morphology and large mesoporosity as well as crystalline anatase mesopore walls, these uniform TiO2 nanosheets are capable of providing large accessible voids for sodium ion adsorption and intercalation as well as preventing volume expansion. As expected, these mesoporous TiO2 nanosheets have exhibited an excellent reversible capacity of 220 mAh g-1 at 100 mA g-1 as sodium-ion battery anodes, and they can retain at 199 mAh g-1 after numerous cycles at different current densities. The capacity is retained at 44 mAh g-1 even at a large current density of 10 A g-1 after 10 000 cycles, demonstrating a remarkable performance for energy storage.

Toward Hypertension Prediction Based on PPG-Derived HRV Signals: a Feasibility Study.

Heart rate variability (HRV) is often used to assess the risk of cardiovascular disease, and data on this can be obtained via electrocardiography (ECG). However, collecting heart rate data via photoplethysmography (PPG) is now a lot easier. We investigate the feasibility of using the PPG-based heart rate to estimate HRV and predict diseases. We obtain three months of PPG-based heart rate data from subjects with and without hypertension, and calculate the HRV based on various forms of time and frequency domain analysis. We then apply a data mining technique to this estimated HRV data, to see if it is possible to correctly identify patients with hypertension. We use six HRV parameters to predict hypertension, and find SDNN has the best predictive power. We show that early disease prediction is possible through collecting one's PPG-based heart rate information.

A Survey of Data Mining and Deep Learning in Bioinformatics.

The fields of medicine science and health informatics have made great progress recently and have led to in-depth analytics that is demanded by generation, collection and accumulation of massive data. Meanwhile, we are entering a new period where novel technologies are starting to analyze and explore knowledge from tremendous amount of data, bringing limitless potential for information growth. One fact that cannot be ignored is that the techniques of machine learning and deep learning applications play a more significant role in the success of bioinformatics exploration from biological data point of view, and a linkage is emphasized and established to bridge these two data analytics techniques and bioinformatics in both industry and academia. This survey concentrates on the review of recent researches using data mining and deep learning approaches for analyzing the specific domain knowledge of bioinformatics. The authors give a brief but pithy summarization of numerous data mining algorithms used for preprocessing, classification and clustering as well as various optimized neural network architectures in deep learning methods, and their advantages and disadvantages in the practical applications are also discussed and compared in terms of their industrial usage. It is believed that in this review paper, valuable insights are provided for those who are dedicated to start using data analytics methods in bioinformatics.

Constructing Three-Dimensional Mesoporous Bouquet-Posy-like TiO2 Superstructures with Radially Oriented Mesochannels and Single-Crystal Walls.

Constructing three-dimensional (3-D) hierarchical mesostructures with unique morphology, pore orientation, single-crystal nature, and functionality remains a great challenge in materials science. Here, we report a confined microemulsion self-assembly approach to synthesize an unprecedented type of 3-D highly ordered mesoporous TiO2 superstructure (Level-1), which consists of 1 spherical core and 12 symmetric satellite hemispheres epitaxially growing out of the core vertices. A more complex and asymmetric TiO2 superstructure (Level-2) with 13 spherical cores and up to 44 symmetric satellite hemispheres can also be well manipulated by increasing the size or content of impregnated TiO2 precursor emulsion droplets. The obtained 3-D mesoporous TiO2 superstructures have well-defined bouquet-posy-like topologies, oriented hexagonal mesochannels, high accessible surface area (134-148 m2/g), large pore volume (0.48-0.51 cm3/g), and well single-crystalline anatase walls with dominant (001) active facets. More interestingly, all cylindrical mesopore channels are highly interconnected and radially distributed within the whole superstructures, and all TiO2 nanocrystal building blocks are oriented grown into a single-crystal anatase wall, making them ideal candidates for various applications ranging from catalysis to optoelectronics. As expected, the bouquet-posy-like mesoporous TiO2 superstructure supported catalysts show excellent catalytic activity (≥99.7%) and selectivity (≥96%) in cis-semihydrogenation of various alkynes, exceeding that of commercial TiO2 (P25) supported catalyst by a factor of 10. No decay in the activity was observed for 25 cycles, revealing a high stability of the mesoporous TiO2 superstructure supported catalyst.