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Cell migration is an essential physiological process in the life cycle of cells, playing a crucial role in cancer metastasis, neural development, and cellular immune response. However, achieving precise control of cell migration at single‐cell level is challenging due to the intricate and diverse microenvironments of cells. Here, an optical technique is presented that utilizes light‐actuated micronavigators to guide the directional migration of individual cells both in vitro and in vivo. Employing high‐speed scanning optical tweezers, micronavigators near target cells are trapped and rotated at a rotation speed of up to 12 000 rpm, which, to the best of knowledge, represents the fastest rotation of light‐driven micromotors in a biological environment to date. The micronavigators generate a powerful fluid shear force (up to 40 pN) which can guide the migration of immune and nerve cells in a predetermined direction. Furthermore, micronavigators are employed to guide cell migration in various biological systems, including lab‐on‐a‐chip devices and blood vessels within living animals. This technique offers new opportunities for controlling cell migration, enabling precise immune activation, and neuron repair at the single‐cell level. [ABSTRACT FROM AUTHOR]

The active delivery of nanodrugs has been a bottleneck problem in nanomedicine. While modification of nanodrugs with targeting agents can enhance their retention at the lesion location, the transportation of nanodrugs in the circulation system is still a passive process. The navigation of nanodrugs with external forces such as magnetic field has been shown to be effective for active delivery, but the existing techniques are limited to specific materials like magnetic nanoparticles. In this study, an alternative actuation method is proposed based on optical manipulation for remote navigation of nanodrugs in vivo, which is compatible with most of the common drug carriers and exhibits significantly higher manipulation precision. By the programmable scanning of the laser beam, the motion trajectory and velocity of the nanodrugs can be precisely controlled in real time, making it possible for intelligent drug delivery, such as inverse‐flow transportation, selective entry into specific vascular branch, and dynamic circumvention across obstacles. In addition, the controlled mass delivery of nanodrugs can be realized through indirect actuation by the microflow field. The developed optical manipulation method provides a new solution for the active delivery of nanodrugs, with promising potential for the treatment of blood diseases such as leukemia and thrombosis. [ABSTRACT FROM AUTHOR]

With high reconfigurability and swarming intelligence, programmable medical micromachines (PMMs) represent a revolution in microrobots for executing complex coordinated tasks, especially for dynamic routing of various targets along their respective routes. However, it is difficult to achieve a biocompatible implantation into the body due to their exogenous building blocks. Herein, a living microrouter based on an organic integration of endogenous red blood cells (RBCs), programmable scanning optical tweezers and flexible optofluidic strategy is reported. By harvesting energy from a designed optical force landscape, five RBCs are optically rotated in a controlled velocity and direction, under which, a specific actuation flow is achieved to exert the well‐defined hydrodynamic forces on various biological targets, thus enabling a selective routing by integrating three successive functions, i.e., dynamic input, inner processing, and controlled output. Benefited from the optofluidic manipulation, various blood cells, such as the platelets and white blood cells, are transported toward the damaged vessel and cell debris for the dynamic hemostasis and targeted clearance, respectively. Moreover, the microrouter enables a precise transport of nanodrugs for active and targeted delivery in a large quantity. The proposed RBC microrouter might provide a biocompatible medical platform for cell separation, drug delivery, and immunotherapy. [ABSTRACT FROM AUTHOR]

As an important waveform feature, the number of peaks indicates the complexity of the surface coverage within the laser footprint. At present, the common methods of determining the number of peaks are based on waveform decomposition because the full waveform can be regarded as the superposition of multiple Gaussian waves. However, the empirical thresholds can affect the performance of the algorithms, and the process is time-consuming and inefficient. This study attempts to develop an automatic peak-number-driven classifier and picker based on machine learning (ML) and convolutional neural network (CNN) models. Waveforms were divided into four categories according to the peak-number. The results of five classifiers show good agreement with the verification data from GLAH14, with overall accuracies of 90.65%, 92.69%, 92.45%, 91.95%, and 93.05%. Moreover, F1 score was calculated to evaluate the classification performance of each classifier for different categories. The results indicate that each classifier accurately distinguishes waveforms with different numbers of crests, especially invalid and single-peak waveforms. The ability to quickly and automatically extract the number of peaks based on ML methods will be of great benefit for specific research to screen suitable experimental data [ABSTRACT FROM AUTHOR]

In the article "Optically Programmable Living Microrouter in Vivo," Xiaoshuai Liu, Xianchuang Zheng, Baojun Li, and their colleagues introduce a living microrouter that utilizes red blood cells, scanning optical tweezers, and an optofluidic strategy. This integration allows for the selective routing of various biological targets through dynamic input, inner processing, and controlled output. The authors provide a detailed explanation of the development and potential applications of this innovative technology. [Extracted from the article]

Control of blood microflow is crucial for the prevention and therapy of blood disorders, such as cardiovascular diseases and their complications. Conventional control strategies generally implant exogenous synthetic materials into blood vessels as labeling markers or actuating sources, which are invasive and incompatible with biological systems. Here, a label‐free, noninvasive, and biocompatible device constructed from natural red blood cells (RBCs) for controlling blood microflow in vivo is reported. The RBCs, optically manipulated, arranged, and rotated using scanning optical tweezers, can function as an optofluidic switch for targeted switching, directional enrichment, dynamic redirecting, and rotary actuation of blood microflow inside zebrafish. The regulation precision of the switch is determined to be at the single‐cell level, and the response time is measured as ≈200 ms using a streamline tracking method. This in vivo optofluidic switch may provide a biofriendly device for exploring blood microenvironments in a noncontact and noninvasive manner. [ABSTRACT FROM AUTHOR]

SUMMARY Practically, the maximum transmission power of transmission systems is limited. This power constraint causes the variable power control derived from no maximum power limitation suffering from performance degradation. In this paper, a constrained variable-power adaptive M-ary quadrature amplitude modulation scheme for MIMO systems with space-time coding is developed. Convex optimization is used to derive the switching thresholds of the instantaneous signal-to-noise ratio for power control (PC) and adaptive modulation under the constraints of maximum power, average power, and target BER. In the derivation of the relation between modulation and power, the exact BER expression of binary phase shift keying modulation and a tight bound for higher order quadrature amplitude modulation are used to make the PC scheme fulfill the target BER even at low signal-to-noise ratio where the previous PC schemes fail to meet the target BER. Numerical results show that the derived control scheme under the power constraints can obtain the spectrum efficiency and BER performance close to the previous control scheme without power limitation. Moreover, it can satisfy the requirements of power limitation and target BER and can effectively avoid the excessive power consumption of previous PC scheme in poor channel condition. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: A modified chitosan transparent thin membrane (MCTTM) was prepared and used as the adsorbent to investigate the adsorption kinetics due to excellent capacity of removing copper ions in water solution. The structure and morphology of MCTTM were characterized by SEM analysis and FTIR analysis. External mass transfer, intra particle diffusion, and pseudo-first and pseudo-second order models were used to describe the adsorption process. The results obtained from the study illustrated that the adsorption process could be described by the pseudo-second order model, which indicated adsorption process was a chemical adsorption behavior of chelation ion exchange proved by the FTIR and adsorption free energy analysis. External mass transfer and intra particle diffusion processes were the rate-controlling steps. [ABSTRACT FROM AUTHOR]

Living Biosensors: Red-Blood-Cell Waveguide as a Living Biosensor and Micromotor (Adv. Funct. In article number 1905568, Yao Zhang, Baojun Li, and co-workers report a biocompatible biosensor and micromotor that are assembled with an in vivo red blood cell waveguide. The living biosensor is used for the diagnosis of pH-related disorders of the blood; the waveguide can rotate as a micromotor and transport microparticles to the target region. [Extracted from the article]

With great potential in intelligent sensing and actuating systems, biosensors and micromotors are expected to be powerful instruments for early diagnosis and drug delivery in precision medicine. However, it is difficult to ensure the synthetic biosensors and micromotors are compatible with biosystems because of their exogenous building blocks. Biocompatible biosensors and micromotors assembled are reported from living red blood cells (RBCs) optically bound into a waveguide using fiber probes. By monitoring light propagation of the RBC waveguide, the pH of blood solution is detected in real time with an accuracy of 0.05. This can be used for the diagnosis of pH‐related disorders of the blood. After diagnosis, optical torque is exerted on the RBC waveguide, allowing it to rotate as a micromotor and transport microparticles to a target region. The RBC waveguide is then constructed inside zebrafish blood vessels to validate in vivo application. The living biosensors and micromotors are expected to provide a "smart" platform for precise biosensing, medical analysis, and drug delivery. [ABSTRACT FROM AUTHOR]

The shore zone is the most active zone in the atmosphere, hydrosphere, biosphere and lithosphere of nature, and has the environmental characteristics of both ocean and land. The ICESat-2 satellite provides height measurements of shore zone using a photon-counting LiDAR. The purpose of this study is to explore the application potential of ICESat-2 satellite data in shore zone classification. Saint Lawrence Island, Alaska, was chosen as the study area. Firstly, in this study, the upper and lower boundaries of the shore zone of the study area were extracted based on Google Earth images. The slope and width between the two boundaries were then calculated according to the formula. Secondly, six statistical indicators (standard deviation, relative standard deviation, average absolute deviation, relative average deviation, absolute median error and quartile deviation) related to the substrate and sediment classification that could reflect the characteristics of the shore zone profile were extracted, and the statistical indicators were used as input parameters of the softmax regression model for classification. Finally, the accuracy of the shore zone classification was validated using the ShoreZone classification system. The results show that, among the 246 shore zone sections in the study area, 86% (212) has been correctly classified. The results therefore indicate that ICESat-2 data can be used to support the characterization of shore zone morphology. [ABSTRACT FROM AUTHOR]

[Display omitted] • The auxiliary cementitious materials can effectively fill the micropores and shorten the interfacial transition zone. • The developed elastoplastic parallel bonding model can record the irreversible damage during freeze–thaw cycles. • The decay constants of UCS and elastic modulus after freeze–thaw cycles can be estimated from the initial parameters. In this paper, pervious concrete (PC) was prepared using fly ash, granulated blast furnace slag, and rice husk ash as supplementary cementitious materials (SCMs), and the mechanical properties, water permeability, and freeze–thaw durability of permeable concrete were mainly investigated. Discrete elements (DEM) were used to mimic the freeze–thaw cycle process of pervious concrete to assess better how freeze–thaw cycles affect the mechanical properties of pervious concrete. To allow water particles of various sizes to fill the model pores, new algorithms were developed. However, since some connected pores release some of the pressure generated by water expansion when undergoing FTCs, two different water particles must be defined. Meanwhile, an elastoplastic parallel bond contact model (EPPBM) was created to account for any residual strain brought on by water freeze–thaw expansion at the aggregate bond. Through experiments, it was determined that adding SCMs increased the compressive strength of the pervious concrete by 1.22 %, 15.32 %, 32.34 %, and 35.20 % at 7, 28, 56, and 90 days compared to the control group. The microstructure of the hydrated calcium silicate (C-S-H) gel could be relatively dense by SEM. The width of the interfacial transition zone (ITZ) was found to have been effectively shortened by further scanning using EDS. As a result, in the tests of mechanical properties after freeze–thaw cycles (25, 50, 75, and 100 cycles), there was a significant improvement in the loss of strength compared to the control group, which was 2.13 %, 6.91 %, 10.04 %, and 17.40 %, respectively. Using numerical simulation to correct the functional correlation between FTCs and the mechanical characteristics of permeable concrete, the trend essentially aligns with the experiment's results, demonstrating the model's viability. Acoustic emission monitoring of model rupture location and strain energy loss after FTCs were utilized and the effect of different porosity and initial uniaxial compressive strength (UCS) on the attenuation constant of the freeze–thaw resistance of pervious concrete was analyzed. The decay constant of UCS increased with increasing porosity and elastic modulus while decreasing with increasing initial UCS. Therefore, the decay constant of UCS and elastic modulus after arbitrary FTCs can be easily estimated using the initial parameters of the pervious concrete. [ABSTRACT FROM AUTHOR]

Formation of cell chains is a straightforward and efficient method to study the cell interaction. By regulating the contact sequence and interaction distance, the influence of different extracellular cues on the cell interaction can be investigated. However, it faces great challenges in stable retaining and precise regulation of cell chain, especially in cell culture with relatively low cell concentration. Here we demonstrated an optical method to realize the precise regulation of cell chain, including removing or adding a single cell, adjusting interaction distance, and changing cell contact sequence. After injecting a 980-nm wavelength laser beam into a tapered optical fiber probe (FP), a cell chain of Escherichia colis (E. colis) is formed under the optical gradient force. By manipulating another FP close to the cell chain, a targeted E. coli cell can be trapped by the FP and removed from the chain. Further, the targeted cell can be added back to the chain at different positions to change the cell contact sequence. The experiments were interpreted by numerical simulations and the impact of cell sizes and shapes on this method was analyzed. [ABSTRACT FROM AUTHOR]

Ice, Cloud, and land Elevation Satellite-2 (ICESat-2), the first photon-counting laser altimetry satellite, is the most advanced on-orbit altimetry system in the world. The data obtained by it contain a large number of background photons, limited by sensitive photon detection system. In this study, a density-based adaptive method (DBAM) for photons detection of ground and canopy method is proposed, which is aimed at solving the problem of signal photons detection in vegetation areas. First, the photon density is homogenized according to the noise photon rate, to reduce the effect of uneven background noise. Then, the ground signal photons were extracted by the search ellipse adaptively changing direction and size along the slope direction to find the maximum density direction. The canopy signal photons were extracted again from the rest photons of the first step by using a vertical elliptical search area. At last of the DBAM, the photons between the ground and the canopy are extracted as vegetation signal photons. The effectiveness of DBAM is evaluated both quantitatively and qualitatively. The results show that the proposed method can effectively detect ground and canopy photons, with the Kappa coefficient of 0.88 and 0.91 of two selected datasets. Compared to the results of ATL08, DBAM can better adapt to the slope, the extracted ground photons have better continuity and can extract more accuracy vegetation photons. [ABSTRACT FROM AUTHOR]

The ultrastructure of the egg chorion surface in the loachMisgurnus anguillicaudatuswas investigated using scanning electron microscopy (SEM). A single micropyle, which belonged to type II, was found at the animal pole of anM. anguillicaudatusegg. Several sinistral grooves which originated at the micropyle probably served for sperm guidance. The egg envelope had numerous pores with bud-like fillings and a regular arrangement like honeycomb. Lots of small knobs were situated on the zona radiata at the vegetal pole. Water contact triggered egg stickiness within about 10 seconds. The egg surface became smooth after treatment with trypsin solution. The features of the micropyle, pores and stickiness were correlated with the reproductive strategy of the loach and are important for egg identification. [ABSTRACT FROM AUTHOR]

Therapid progresses in biological and biomedical applications with opticalinterfaces have motivated an ever-increasing demand for biocompatibleand disposable photonic components. Generally, these biophotonic componentsare first integrated with biocompatible materials and then interfacedwith biological samples, such as living cells, for biological use.Therefore, direct formation of biophotonic components using livingcells is greatly desired because the cells would serve simultaneouslyas samples and optical elements for signal sensing and detection.Here, we report an optical strategy for direct formation of biophotonicwaveguides (bio-WGs) with Escherichia coli. The experimentsdemonstrate that this facile optical strategy enables forming bio-WGswith different lengths and good light propagation performances whilethe propagating signal can be detected in real-time. This strategyoffers a seamless interface between optical and biological worldswith natural materials and provides a new opportunity for direct sensingand detection of biological signal and information in biocompatiblemicroenvironments. [ABSTRACT FROM AUTHOR]

The visual perception of a moving target is not always true. Wheels turning rapidly, for instance, may look like rotating inversely. This phenomenon is known as the wagon‐wheel effect (WWE) and it is caused by the undersampling of visual information. Here, an analogous manifestation of the WWE concept is described in the scenario of light–matter interactions, by showing that the dynamic response of a particle, to an optical trap scanned at different rates, can be diametrically opposed. Further, such behaviors are modulated by the particle dimensions, which can be exploited for particle size selection. The results uncover a distinct paradigm of nontrivial optical manipulation and expand the bidirectional optical sorting range of dielectric particles to the sub‐200 nm scale. [ABSTRACT FROM AUTHOR]

The hatchery-raised juveniles of Schizothorax wangchiachii, a species widely distributed in the Jinsha River and its tributaries in China, have shown improved swimming performance through exercise training. Understanding the underlying biological processes and molecular mechanisms responsible for this enhanced swimming ability is crucial. In this research, the transcriptome of muscle tissue was sequenced for juvenile S. wangchiachii subjected to exercise training. After thorough data processing, a total of 113,814 unigenes were obtained, with 57,500 of them annotated using various datasets including Pfam, GO, COG, Swiss-Prot, NR, and KEGG. The study identified 889 differentially expressed genes (DEGs) between the experimental and control groups after 30 days of exercise training, of which 439 were upregulated and 450 downregulated. Enrichment analysis highlighted that these DEGs were predominantly involved in molecular processes such as protein metabolism and breakdown, neurodevelopment, immunity, and growth and development. The expression patterns of the DEGs were validated through real-time PCR, corroborating the findings derived from transcriptome analysis. Further experimental investigation led to the recognition of MYLPF as a potential functional candidate gene for swimming ability in S. wangchiachii. The results provide novel insights into how S. wangchiachii adapts to exercise training, contributing to a deeper comprehension of the mechanisms that underlie exercise-induced improvements in fish swimming performance. [ABSTRACT FROM AUTHOR]

It is advantageous for fish to choose different substrate types and brightness based on their current life cycle stage, foraging requirements, predator avoidance and water conditions. We determined the substrate type and brightness preference of hatchery‐reared and wild juvenile Schizothorax wangchiachii and Percocypris pingi under laboratory conditions. Individuals and groups were exposed to four kinds of substrate types (sand: diameter < 1 mm, small gravel: diameter approximately 2–3 cm, large gravel: diameter approximately 10–15 cm, sand and medium gravel mix: diameter approximately 4–7 cm) and two kinds of substrate brightness (black and white). The results showed that hatchery‐reared and wild S. wangchiachii and P. pingi significantly preferred large gravel and black substrates regardless of the number of fish (p <.05). P. pingi had a significantly higher preference for black substrate than S. wangchiachii both in hatchery‐reared and wild individuals (p <.05). Hatchery‐reared and wild individuals of the two species shared a preference for large gravel and black substrates suggesting that substrate preferences might be genetically based. The findings in the present study could be used to improve the rearing conditions for the two species in hatchery and thereafter to enhance its adaptability after releasing to the wild. [ABSTRACT FROM AUTHOR]

The intensity gradient of light represents the most important property for optical tweezers to manipulate small particles, which is known to produce a conservative optical force that is either attractive or repulsive. Here, it is shown that Kerker interference, the interplay between electric and magnetic dipoles induced in nanoparticles, permits the intensity gradient to exert a nonconservative optical force, in the case of a standard optical trap created with linearly or elliptically polarized Gaussian beams. The Kerker‐type intensity‐gradient force has an "anisotropic" directionality, and it tends to repel particles away from the beam axis. Such repulsive effects can greatly sensitize the particle trapping behavior of optical tweezers to the particle size. Utilizing these peculiar properties, all‐optical sorting of Si nanoparticles is theoretically demonstrated, with tunable size‐selection criterion and accuracy. [ABSTRACT FROM AUTHOR]

Non-contact intracellular binding and controllable manipulation of chloroplasts in vivo was demonstrated using an optical fiber probe. Launching a 980-nm laser beam into a fiber, which was placed about 3 μm above the surface of a living plant (Hydrilla verticillata) leaf, enabled stable binding of different numbers of chloroplasts, as well as their arrangement into one-dimensional chains and two-dimensional arrays inside the leaf without damaging the chloroplasts. Additionally, the formed chloroplast chains were controllably transported inside the living cells. The optical force exerted on the chloroplasts was calculated to explain the experimental results. This method provides a flexible method for studying intracellular organelle interaction with highly organized organelle-organelle contact in vivo in a non-contact manner. [ABSTRACT FROM AUTHOR]

Micropumps can generate directional microflows in blood vessels or bio-capillaries for targeted transport of nanoparticles and cells in vivo , which is highly significant for biomedical applications from active drug delivery to precision clinical therapy. Meanwhile, they have been extensively used in the biosensing fields with their unique features of autonomous motion, easy surface functionalization, dynamic capture and effective isolation of analytes in complex biological media. However, synthetic devices for actuating microflows, including pumps and motors, generally exhibit poor or limited biocompatibility with living organisms as a result of the invasive implantation of exogenous materials into blood vessels. Here we demonstrate a method of constructing endogenous micropumps by extracting nuclei from red blood cells, thus making them intrinsically and completely biocompatible. The nuclei are extracted and then driven by a scanning optical tweezing system. By a precise actuation of the microflows, nanoparticles and cells are navigated to target destinations, and the transport velocity and direction is controlled by the multifunctional dynamics of the micropumps. With the targeted transport of functionalized micro/nanoparticles followed by a dynamic mixing in microliter blood samples, the micropumps provide considerable promises to enhance the target binding efficiency and improve the sensitivity and speed of biological assays in vivo. Furthermore, multiplexing by simultaneously driving an array of multiple nuclei is demonstrated, thus confirming that the micropumps could provide a bio-friendly high-throughput in vivo platform for the treatment of blood diseases, microenvironment monitoring, and biomedical analysis. • A light-driven micropump was constructed with endogenous cell nucleus to transport nanoparticles and cells in vivo. • The bio-friendly micropump was free from invasive implantation of exogenous matters and independent of particle composition. • Multifunctional dynamics of micropumps assured a real-time control of the transport velocity and directions. • A high-throughput platform can be accomplished by multiplexing an array of multiple nucleus micropumps. [ABSTRACT FROM AUTHOR]

Intensity-Gradient Force: Kerker-Type Intensity-Gradient Force of Light (Laser Photonics Rev. 14(4)/2020) In article number 1900265 by Yao Zhang and co-workers, a nontrivial optical intensity-gradient force is uncovered in conventional optical tweezers set-ups. Its non-conservative and anisotropic properties are in sharp contrast to the classical widespread picture of optical intensity-gradient forces. [Extracted from the article]