Search

Photodynamic therapy (PDT) is a significant noninvasive therapeutic modality, but it is often limited in its application due to the restricted tissue penetration depth caused by the wavelength limitations of the light source. Two-photon (TP) fluorescence techniques are capable of having an excitation wavelength in the NIR region by absorbing two NIR photons simultaneously, which offers the potential to achieve higher spatial resolution for deep tissue imaging. Thus, the adoption of TP fluorescence techniques affords several discernible benefits for photodynamic therapy. Organic TP dyes possess a high fluorescence quantum yield. However, the biocompatibility of organic TP dyes is poor, and the method of coating organic TP dyes with silica can effectively overcome the limitations. Herein, based on the TP silica nanoparticles, a functionalized intelligent biogenic missile TP-SiNPs-G4(TMPyP4)-dsDNA(DOX)-Aptamer (TGTDDA) was developed for effective TP bioimaging and synergistic targeted photodynamic therapy and chemotherapy in tumors. First, the Sgc8 aptamer was used to target the PTK7 receptor on the surface of tumor cells. Under two-photon light irradiation, the intelligent biogenic missile can be activated for TP fluorescence imaging to identify tumor cells and the photosensitizer assembled on the nanoparticle surface can be activated for photodynamic therapy. Additionally, this intelligent biogenic missile enables the controlled release of doxorubicin (DOX). The innovative strategy substantially enhances the targeted therapeutic effectiveness of cancer cells. The intelligent biogenic missile provides an effective method for the early detection and treatment of tumors, which has a good application prospect in the real-time high-sensitivity diagnosis and treatment of tumors.

Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) protein systems are adaptive immune systems unique to archaea and bacteria, with the characteristics of targeted recognition and gene editing to resist the invasion of foreign nucleic acids. Biosensors combined with the CRISPR/Cas system and optical detection technology have attracted much attention in medical diagnoses, food safety, agricultural progress, and environmental monitoring owing to their good sensitivity, high selectivity, and fast detection efficiency. In this review, we introduce the mechanism of CRISPR/Cas systems and developments in this area, followed by summarizing recent progress on CRISPR/Cas system-based optical biosensors combined with colorimetric, fluorescence, electrochemiluminescence and surface-enhanced Raman scattering optical techniques in various fields. Finally, we discuss the challenges and future perspectives of CRISPR/Cas systems in optical biosensors.

To realize robot skill learning in the real world, reinforcement learning algorithms need to be applied in continuous problems with high sample efficiency. Hybrid intelligence is regarded as an available solution for this problem, due to the ability to speed up the learning process with human knowledge and experience. Therefore, we propose Episode-Fuzzy-COACH (COrrective Advice Communicated by Humans), to imitate human fuzzy logic and involve human intelligence in the learning process. In this framework, human knowledge and experience are involved in the learning process, which are provided by human feedback and fuzzy rules designed by human users. Moreover, it is combined with Path Integrals Policy Improvement ($PI^{2}$), to realize hybrid intelligence, which is used to realize fast robot skill learning. Throwing Movement Primitives proposed in this article is used to represent the policy of ball-throwing skill. According to the simulation results, the learning efficiency of our method is increased by 72% and 42.86%, respectively, compared with pure $PI^{2}$ and $PI^{2}+$COACH. Our method validated in experiments is 46.67% more effective than $PI^{2}+$COACH. The results also show that the performance of our method is not affected by users' knowledge level of the related field. It is proven that $PI^{2}+$Episode-Fuzzy-COACH is available for fast robot skill learning.

Penehyclidine hydrochloride (PHC) has been used for many years as an anticholinergic drug for the treatment of acute organophosphorus pesticide poisoning (AOPP). The purpose of this meta-analysis was to explore whether PHC has advantages over atropine in the use of anticholinergic drugs in AOPP.

The metal plate structure is more and more widely used in many fields, such as aerospace, high-speed railway, civil engineering, etc. In the process of long-term service, this structure is susceptible to cracks, spalling, fatigue, and other damages caused by external load impact, chemical corrosion, and other effects. A significant challenge is to find and determine the location of small damage. Aiming to address this problem, the frequency-wavenumber (f-k) domain filtering method is adopted. According to the corresponding relationship between the propagation direction of the guided wave and the frequency wavenumber matrix and combined with the characteristics of the difference in wavenumber of different modes of guided waves at the same frequency, a three-dimensional window function is constructed to realize the extraction of different modes and their corresponding damage reflection signals. The Common Source Method (CSM) time domain and f-kdomain imaging methods have been used to achieve damage imaging. Finally, the data fusion imaging method has been used to weight the damage imaging results of different modes to further improve the accuracy of damage imaging.

When the COB packaging LED light source is prepared by the centrifugal precipitation process, the phosphor forms a high-density phosphor layer on the chip surface. Centrifugal speed can change the vertical distribution of different kinds of particles in the phosphor coating, which affects the color parameters of the LED light source. Several different centrifugal speeds are used, the luminous flux of the sample has increased by about 5%, and the color temperature of the light source is also rising. The color temperature increases with the addition of the rotating speed, and the color temperature adds up to 278.6 K at 500 r/min and 422.4 K at 1000 r/min. The first reason for this phenomenon is that the proportion of large particles at the bottom of the phosphor layer formed by centrifugal precipitation (close to the chip) increases, which increases the conversion efficiency of phosphor. Second, after the powder is precipitated, a phosphor thin layer composed of very small particles will be formed on the upper surface of the phosphor layer. The higher the rotational speed, the thinner this thin layer, the smaller the absorption effect on the short-wave part of the spectrum, and the overall color temperature of the light source increases slightly. Third, the proportion of high-density yellow-green powder at the bottom of the phosphor layer formed by the centrifugal precipitation process is higher, and the photoluminescence produces a yellow-green band.

Morphing botanical tissues and animal muscles are all fiber-mediated composites, in which fibers play a passive and active role, respectively. Herein, inspired by the mechanism of fibers functioning in morphing botanical tissues and animal muscles, we propose two sorts of fiber-dominated composite actuators. First, inspired by the deformation of awned seeds in response to humidity change, we fabricate passive fiber-dominated actuators using non-active aligned carbon fibers via 4D printing method. The effects of process parameters, structural parameters, and fiber angles on the deformation of the printed actuators are examined. The experimental results show that the orientation degree is enhanced, resulting in a better swelling effect as the printing speed increases. Then, motivated by the actuation mechanism of skeletal muscle, we prepare active fiber-dominated actuators using active polyurethane fibers via 4D printing and pre-stretching method. The effect of fiber angle and loading on the actuation mode is experimentally analyzed. The experimental results show that the rotation angle of the actuator gradually decreases with the angle from 45° to 60°. When the fiber angle is 0° and 90°, the driver basically stops rotating while shrinking along the loading direction. Based on the above actuation mechanisms, identical contraction behaviors are realized both in passive and active fiber-dominated soft actuators. This work provides a validation method for biologically actuation mechanisms via 4D printing technique and smart materials and adds further insights to the design of bioinspired soft actuators.

A mild, external photocatalyst‐ and additive‐free protocol for photo‐induced alkylation/cyclization of unactivated alkenes with halides has been developed. This strategy showed excellent regioselectivity and simple operation to synthesize alkyl‐substituted quinazolinones with a broad substrate scope. More importantly, chlorinated alkanes were also compatible with this transformation. A mild, external photocatalystand additive‐free protocol for photo‐induced alkylation/cyclization of unactivated alkenes with halides has been developed.

Pilot studies and the long-term stability of titanium-based ion sieve adsorbents for salt lake lithium extraction are rarely reported. In this study, the influence of different experimental conditions on the adsorption performance of the titanium adsorbent was tested using a pilot-scale device and alkaline brine from Laguo Co Salt Lake in Xizang, China. Subsequently, 600 cycles of continuous adsorption and desorption tests were conducted to study the long-term stability of the titanium adsorbent over 5 months. Li+recovery and Li+adsorption capacity of the adsorbent were around 80% and 2.20 g/L. The concentrations of Li+, Na+, K+, Mg2+, Ca2+, and B3+in the desorption tailings were around 1.5, 0.65, 0.15, 0.50, 0.18, and 0.04 g/L, respectively. Additionally, these performance parameters did not significantly deteriorate over 600 cycles of the pilot scale tests. XRD, SEM, and contact angle measurements showed that the main component of the adsorbent was lithium metatitanate, with numerous irregular pores promoting mass transfer efficiency. Additionally, the adsorbent demonstrated good hydrophilic properties, enabling full contact with the brine and achieving efficient adsorption and lithium recovery.

Currently, four-dimensional (4D) printing programming methods are mainly structure-based, which usually requires more than one material to endow products with site-specific attributes. Here, we propose a new 4D printing programming approach that enables site-specific shape-morphing behaviors in a single material by regulating the printing parameters. Specifically, a direct ink writing three-dimensional (3D) printer with the ability to change printing parameters (e.g., deposition speed) on the fly is reported. By site-specifically adjusting print speed and print path to control the local nematic arrangements of printed liquid crystal elastomers (LCEs), the shape-morphing behaviors of the LCEs can be successfully programmed. In this way, locally programmed popping-up, self-assembling, and oscillating behaviors can be designed by varying the print speed in specific regions. Snake-like curling is realized by uniformly boosting the print speed in a single line. Furthermore, two theories and an ultrasound image diagnostic apparatus are employed to reveal the mechanism behind this behavior. This work provides a feasible way to realize the gradient transition of material properties through a single material. It broadens the design space and pushes the envelope of 4D printing, which is expected to be helpful in the fabrication of soft robotics and flexible electronics.

As a “sister” of porphyrins, boron dipyrromethenes (BODIPY) have attracted widespread attention because of their strong absorption in the visible region. Although many modifications have been made to its structure, the photoelectric conversion efficiency (PCE) below 10% limits its practical application in dye-sensitized solar cells (DSSCs). In this work, heterocycles were introduced into the BODIPY π-bridge to improve the photoelectric properties of dyes. Theoretical calculations show that the introduction of heterocycles, such as cyclopentadiene, pyrrole, furan, and thiophene, not only increases the molecular planarity and narrows the band gap but also enhances the light harvesting ability. Based on these exciting results, the dye/(TiO2)38adsorption models and parameters related to DSSC performance including short-circuit current, open circuit voltage, and PCE were considered to evaluate the overall properties of the investigated dyes. These dyes achieve a PCE value of at least 15.25%, wherein the PCE value of dye inserted thiophene into BODIPY can be as high as 23.12%, which are expected to have potential application in DSSC devices.

Identifying changes in coal permeability with gas pressure and accurately codifying mean effective stresses in laboratory samples are crucial in predicting gas-flow behavior in coal reservoirs. Traditionally, coal permeability to gas is assessed using the steady-state method, where the equivalent gas pressure in the coal is indexed to the average of upstream and downstream pressures of the coal, while ignoring the nonlinear gas pressure gradient along the gas flow path. For the flow of a compressible gas, the traditional method consistently underestimates the length/volume-averaged pressure and overestimates mean effective stress. The higher the pressure differential within the sample, the greater the error between the true mean pressure for a compressible fluid and that assumed as the average between upstream and downstream pressures under typical reservoir conditions. A correction coefficient for the compressible fluid pressure asymptotes to approximately 1.3%, representing that the error in mean pressure and effective stress can be on the order of approximately 30%, particularly for highly pressure-sensitive permeabilities and compressibilities, further amplifying errors in evaluated reservoir properties. We utilized this volume-averaged pressure and effective stress to correct permeability and compressibility data reported in the literature. Both the corrected initial permeability and the corrected pore compressibility were found to be smaller than the uncorrected values, due to the underestimation of the true mean fluid pressure, resulting in an overestimation of reservoir permeability if not corrected. The correction coefficient for the initial permeability ranges from 0.6 to 0.1 (reservoir values are only approximately 40% to 90% of laboratory values), while the correction coefficient for pore compressibility remains at approximately 0.75 (reservoir values are only approximately 25% of laboratory value). Errors between the uncorrected and corrected parameters are quantified under various factors, such as confining pressure, gas sorption, and temperature. By analyzing the evolutions of the initial permeability and pore compressibility, the coupling mechanisms of mechanical compression, adsorption swelling, and thermal expansion on the pore structure of the coal can be interpreted. These findings can provide insights that are useful for assessing the sensitivity of coal permeability to gas pressure as truly representative of reservoir conditions.

Fiber is a crucial element in biological micro-structural materials. Replication of fiber-reinforced composites with analogous architectures of their natural counterparts has caused widespread academic concern. Recent researches indicate 3D printing technology has the potential to produce biomimetic structural materials. The aim of this study is to develop a process to fabricate fiber-reinforced composites with ordered yet spatially tunable fiber arrangement. Specifically, we present a method to align fibers during the 3D printing of fiber-reinforced composites. A modified slurry-based stereolithography process was developed, and the fibers in the fiber–resin mixture were aligned by Shear force produced during the spreading of slurry. We investigated the influence of relative factors on fiber orientation, and two models were used to uncover the internal mechanism. By controlling the speed and the direction of the moving blade, the patterns that fibers were arranged can be freely programmed. Therefore, we have extracted bioinspired sinusoidal and zigzag design motifs to analyze their mechanical properties compared with non-bioinspired motifs. The proposed method is relatively material agnostic, more efficient and more facile. It thus provides a promising route to fabricate fiber-reinforced composites, and has potential to be adopted in biological structures researches and industrial applications.

Multi-material additive manufacturing has recently flourished due to its capability to fully exploit the potential of 3D printing for constructing sophisticated heterogeneous material structures. However, producing filaments with tunable internal heterogeneous architecture is difficult in current extrusion-based 3D printing processes. Herein, a novel rotational co-extrusion 3D printing method is proposed that can enable the programmable material configuration of extruded filaments, which is achieved by using a rotatable Y-shape nozzle. By coordinating the rotation and movement of the extrusion nozzle, as well as the air pressure, the material conformation of extruded filaments can be controlled. This strategy can achieve a variety of spatial distribution configurations of heterogeneous materials. In addition, different patterns with customized surface textures have been produced. Furthermore, the 4D printed heterogeneous hydrogels with differential stimuli-responsive properties are demonstrated to generate well-regulated shape-morphing as pre-designed. This method provides an intrinsic ability for 3D printing to construct heterogeneous-filament structures, which have potential applications in the fields of reconfigurable structural materials, tunable meta-materials, tissue engineering, soft robots, etc.

Shear-induced mesogen alignments are commonly used to program the morphing behaviors of liquid crystal elastomers (LCEs) in the material extrusion process of 4D printing. The 4D printing parameters are intimately relevant to the alignment degrees and actuation strains of printed LCEs filaments. Nevertheless, there is still a lack of systematic research on the interaction of 4D printing parameters on shape morphing behavior of LCEs so far. Here, the multi-parameter-encoded 4D printing is proposed for systematically uncovering the process-structure-property relationships and programming the shape morphing behaviors of LCEs. The impact of multiple parameters (print speed, extrusion pressure, printing height, and UV light intensity) on the filament shape and actuation strains are analyzed using experiments and simulations, respectively. The role of UV light intensity on the TNIhas been revealed and adopted for programming the threshold temperature, immediate state and actuation strain of printed LCEs. To demonstrate the feasibility of the multi-parameter-encoded 4D printing method, various parameters codes are integrated into the samples with the same geometric features and successfully enable distinct localized shape morphing behaviors. The multi-parameter-encoded 4D printing method allows on-demand modulation of local deformation features of LCEs structures solely through parametric design, thus providing additional design freedom and versatile tools for building soft robotics, artificial muscles, flexible electronics, etc.

Bioimaging is widely used in various fields of modern medicine. Fluorescence imaging has the advantages of high sensitivity, high selectivity, noninvasiveness, in situ imaging, and so on. However, one-photon (OP) fluorescence imaging has problems, such as low tissue penetration depth and low spatiotemporal resolution. These disadvantages can be solved by two-photon (TP) fluorescence imaging. However, TP imaging still uses fluorescence intensity as a signal. The complexity of organisms will inevitably affect the change of fluorescence intensity, cause false-positive signals, and affect the accuracy of the results obtained. Fluorescence lifetime imaging (FLIM) is different from other kinds of fluorescence imaging, which is an intrinsic property of the material and independent of the material concentration and fluorescence intensity. FLIM can effectively avoid the fluctuation of TP imaging based on fluorescence intensity and the interference of autofluorescence. Therefore, based on silica-coated gold nanoclusters (AuNCs@SiO2) combined with nucleic acid probes, the dual-mode nanoprobe platform was constructed for TP and FLIM imaging of intracellular endogenous miRNA-21 for the first time. First, the dual-mode nanoprobe used a dual fluorescence quencher of BHQ2 and graphene oxide (GO), which has a high signal-to-noise ratio and anti-interference. Second, the dual-mode nanoprobe can detect miR-21 with high sensitivity and selectivity in vitro, with a detection limit of 0.91 nM. Finally, the dual-mode nanoprobes performed satisfactory TP fluorescence imaging (330.0 μm penetration depth) and FLIM (τave= 50.0 ns) of endogenous miR-21 in living cells and tissues. The dual-mode platforms have promising applications in miRNA-based early detection and therapy and hold much promise for improving clinical efficacy.

Shape memory polymers with multiple temporary shapes have shown great potential for applications in biomedical, aerospace, and intelligent robotics fields. However, the realization of the multiple shape memory properties of shape memory polymers is currently mostly dependent on formula design. Here, we report a strategy to remotely program the local bending behavior of shape memory composites (SMCs) using an infrared light source. The infrared light source is used to locally activate a single side of the sample with a temporary shape, which induces an asymmetric shape recovery due to the temperature gradient along the thickness direction, and achieves the phototropic response on-demand bending deformation. We exerted control over the bending deformation of the composite prototypes by devising the 3D printing parameters, infrared light intensity, and temporary shape programming. As a demonstration case, we designed and prepared a hand-like structure that can be bent sequentially, a flower whose petals can be excited to fold sequentially, and a digital logic circuit for sequential lighting of LEDs.

In-situ immobilization is a fast soil remediation method that can recover the value of As-contaminated land quickly. Hydrous zirconium oxide was reported for its efficient arsenic adsorption properties in wastewater treatment, but has not been reported in soil remediation with As contamination. Herein, hydrous zirconium oxide modified biochar (BC-Zr) was synthesized along with hydrous ferric oxide modified biochar (BC-Fe) and hydrous titanium oxide modified biochar (BC-Ti). After comparing their As(III)/As(V) adsorption performance under diverse conditions, BC-Zr showed superior As-immobilization potential in both simulated water and real soil leachate environment. To evaluate its performance in soil remediation, pot experiments were conducted in real As-contaminated agricultural soil using cowpea (Vigna unguiculataL.) as an indicator plant. Although all these modified BC could improve the growth of cowpea, the shoot biomass treated by BC-Zr increased by 115.8% than CK, while the As concentration in the stem and leaves decreased by 30.8% and 42.6%, respectively. Interestingly, BC-Zr promoted the root nodule system of cowpea in real As-contaminated soil while BC-Fe and BC-Ti failed. The observation of improved root nodule symbiotic system is significant for further development of soil remediation using in-situ remediation technology. This first successful trial of Zr-based soil amendment indicates the superior As-immobilization property of hydrous zirconium oxide in in-situ remediation of As-contaminated soil, implying the great potential applications of BC-Zr in soil remediation.

A green, sustainable, and straightforward method for the synthesis of unsymmetrical oxalamides via photoinduced C–N/C═O bond formation of bromodifluoroacetamide, amine, and H2O through a triple-cleavage process has been developed. In addition, this approach also provides access to the known bioactive compounds, and a feasible reaction mechanism is proposed. Moreover, the advantages of this transformation, including mild reaction conditions, a broad substrate scope, and operational simplicity, make this protocol attractive for further applications.

The physical processes triggering the fluid flow within the stressed rock are highly complex and not fully understood. The granite sample obtained from Creighton mine, Canada, was subjected to the temperature-pressure effects using a special rock mechanic testing machine equipped with a high precision gas monitor. It is shown that when the sample approached to the peak stress during the uniaxial compression test, the connective cracks instantaneously occurred accompanied by a swarm of AE activities, which suddenly decrease the fluid pore pressure. This change can be able to drive the gas back to the newly emerging crack due to the formation of gas pressure gradient within the damage zones. It is indicated that the different permeabilities among the zones can dominate the suction-exhaust proceeding of pore fluids within rock mass. Beyond the volumetric strain at null, the deformation of the stressed rock leads to a reversely change in pore pressure of closed pores. The feature for the gas emission determined by the changes in pore structure of rock is also discussed and analyzed.

In this work, a novel composite material based on β-cyclodextrin magnetic carbon nanotube (β-CD@MMWCNT) was developed by a one-pot method (in situ co-precipitation) and applied as an adsorbent to remove phenol from oily wastewater. The basic structure, surface morphology, as well as physical and chemical properties of the composite material were analyzed. β-CD@MMWCNT was successfully prepared, confirmed by the attachment of Fe3O4and β-cyclodextrin particles on the surface. The adsorption behavior of phenol on β-CD@MMWCNT conformed to the Langmuir isotherm model and the pseudo-first-order kinetic model. The adsorption was a spontaneous endothermic process, and the adsorption capacity calculated by Langmuir model was 67.67 mg/g at 20 °C. Moreover, the adsorbent still maintained 85% of the adsorption capacity after 7 cycles. Specially, the adsorbent was used to adsorb phenol from simulated oily wastewater, and the removal rate of phenol reached 92.6%. And the possible adsorption mechanisms were also proposed by infrared and Raman spectroscopy. In summary, β-CD@MMWCNT can be used as a potential adsorbent to remove phenol from oily wastewater.

Promoting Blood Circulation and Removing Blood Stasis is key to prevent and treat diabetic nephropathy (DN). After a long-term practice, some JingFang of promoting blood circulation and removing blood stasis (PBCRBS) have been proved to be effective in clinic, which reviewed in this article can regulate the disorder of glucose and lipid metabolism, inhibiting the inflammation as well as oxidative stress of diabetic nephropathy, accordingly reducing renal fibrosis and delaying the degree of DN lesions. The author reviews the research progress of preventing and treating DN by JingFang of PBCRBS in the clinic.