Computational chromatography: A machine learning strategy for demixing individual chemical components in complex mixtures.

Surface-enhanced Raman spectroscopy (SERS) holds exceptional promise as a streamlined chemical detection strategy for biological and environmental contaminants compared with current laboratory methods. Priority pollutants such as polycyclic aromatic hydrocarbons (PAHs), detectable in water and soil worldwide and known to induce multiple adverse health effects upon human exposure, are typically found in multicomponent mixtures. By combining the molecular fingerprinting capabilities of SERS with the signal separation and detection capabilities of machine learning (ML), we examine whether individual PAHs can be identified through an analysis of the SERS spectra of multicomponent PAH mixtures. We have developed an unsupervised ML method we call Characteristic Peak Extraction, a dimensionality reduction algorithm that extracts characteristic SERS peaks based on counts of detected peaks of the mixture. By analyzing the SERS spectra of two-component and four-component PAH mixtures where the concentration ratios of the various components vary, this algorithm is able to extract the spectra of each unknown component in the mixture of unknowns, which is then subsequently identified against a SERS spectral library of PAHs. Combining the molecular fingerprinting capabilities of SERS with the signal separation and detection capabilities of ML, this effort is a step toward the computational demixing of unknown chemical components occurring in complex multicomponent mixtures.

Unveiling practical considerations for reliable and standardized SERS measurements: lessons from a comprehensive review of oblique angle deposition-fabricated silver nanorod array substrates.

Recently, there has been an exponential growth in the number of publications focusing on surface-enhanced Raman scattering (SERS), primarily driven by advancements in nanotechnology and the increasing demand for chemical and biological detection. While many of these publications have focused on the development of new substrates and detection-based applications, there is a noticeable lack of attention given to various practical issues related to SERS measurements and detection. This review aims to fill this gap by utilizing silver nanorod (AgNR) SERS substrates fabricated through the oblique angle deposition method as an illustrative example. The review highlights and addresses a range of practical issues associated with SERS measurements and detection. These include the optimization of SERS substrates in terms of morphology and structural design, considerations for measurement configurations such as polarization and the incident angle of the excitation laser, and exploration of enhancement mechanisms encompassing both intrinsic properties induced by the structure and materials, as well as extrinsic factors arising from wetting/dewetting phenomena and analyte size. The manufacturing and storage aspects of SERS substrates, including scalable fabrication techniques, contamination control, cleaning procedures, and appropriate storage methods, are also discussed. Furthermore, the review delves into device design considerations, such as well arrays, flow cells, and fiber probes, and explores various sample preparation methods such as drop-cast and immersion. Measurement issues, including the effect of excitation laser wavelength and power, as well as the influence of buffer, are thoroughly examined. Additionally, the review discusses spectral analysis techniques, encompassing baseline removal, chemometric analysis, and machine learning approaches. The wide range of AgNR-based applications of SERS, across various fields, is also explored. Throughout the comprehensive review, key lessons learned from collective findings are outlined and analyzed, particularly in the context of detailed SERS measurements and standardization. The review also provides insights into future challenges and perspectives in the field of SERS. It is our hope that this comprehensive review will serve as a valuable reference for researchers seeking to embark on in-depth studies and applications involving their own SERS substrates.

Recent Toolboxes for Chemoselective Dual Modifications of Proteins.

Site-selective chemical modifications of proteins have emerged as a potent technology in chemical biology, materials science, and medicine, facilitating precise manipulation of proteins with tailored functionalities for basic biology research and developing innovative therapeutics. Compared to traditional recombinant expression methods, one of the prominent advantages of chemical protein modification lies in its capacity to decorate proteins with a wide range of functional moieties, including non-genetically encoded ones, enabling the generation of novel protein conjugates with enhanced or previously unexplored properties. Among these, approaches for dual or multiple modifications of proteins are increasingly garnering attention, as it has been found that single modification of proteins is inadequate to meet current demands. Therefore, in light of the rapid developments in this field, this review provides a timely and comprehensive overview of the latest advancements in chemical and biological approaches for dual functionalization of proteins. It further discusses their advantages, limitations, and potential future directions in this relatively nascent area.

Directional Femoral Ultrasound-Guided Compression Technique Using in Percutaneous Mechanical Thrombectomy for Acute Deep Vein Thrombosis: A Retrospective Cohort Study.

OBJECTIVE: The study aimed to investigate the early results of directional femoral ultrasound-guided compression technique (UCT) using in percutaneous mechanical thrombectomy (PMT) for acute deep vein thrombosis (DVT). METHODS: Consecutive single-center patients with acute iliofemoral DVT who underwent PMT from January 2020 to December 2021 were included. Directional femoral UCT was used to adjust the PMT catheter into the residual thrombus in the inguinal region by ultrasound compression to improve the thrombus clearance rate. Patients were retrospectively analyzed and divided into 2 groups based on PMT with or without directional femoral UCT. The primary efficacy outcome was the incidence of post-thrombotic syndrome (PTS) at 24-month follow-up. The secondary efficacy outcomes included common femoral venous thrombus removal grade, total thrombus removal grade, venous primary patency rate, and incidence of moderate-to-severe PTS at 24-month follow-up. The safety outcomes included complications, major bleeding events, and death at 24-month follow-up. RESULTS: A total of 96 patients were included in the study: 42 patients underwent PMT with directional femoral UCT and 54 patients underwent PMT without UCT. There was no significant difference in baseline characteristics between the 2 groups. The percentages of patients achieved common femoral venous thrombus removal grade 3 and total thrombus removal grade 3 were significantly higher in the PMT with UCT group than those in the PMT without UCT group (p<0.001). The 24-month primary patency rate was significantly higher in the PMT with UCT group than that in the PMT without UCT group (90.0% vs 71.2%, p=0.027). The incidence of PTS was significantly lower in the PMT with UCT group (10.0%) than that in the PMT without UCT group (28.8%) (p=0.027). CONCLUSION: PMT with directional femoral UCT could improve the thrombus clearance rate and primary patency rate of acute iliofemoral DVT and might decrease the incidence of PTS compared to traditional PMT treatment without UCT. CLINICAL IMPACT: Residual thrombus in common femoral vein is a difficult problem associated with higher incidence of PTS. Few studies have focused on common femoral venous thrombus clearance. PMT with directional femoral UCT could improve the thrombus clearance rate and primary patency rate of acute iliofemoral DVT, and might decrease the incidence of PTS compared to traditional PMT treatment without UCT. Directional femoral UCT is recommended in PMT treatment of acute iliofemoral DVT.

Suppression of cracking in drying colloidal suspensions with chain-like particles.

The prevention of drying-induced cracking is crucial in maintaining the mechanical integrity and functionality of colloidal deposits and coatings. Despite exploring various approaches, controlling drying-induced cracking remains a subject of great scientific interest and practical importance. By introducing chain-like particles composed of the same material and with comparable size into commonly used colloidal suspensions of spherical silica nanoparticles, we can significantly reduce the cracks formed in dried particle deposits and achieve a fivefold increase in the critical cracking thickness of colloidal silica coatings. The mechanism underlying the crack suppression is attributed to the increased porosity and pore sizes in dried particle deposits containing chain-like particle, which essentially leads to reduction in internal stresses developed during the drying process. Meanwhile, the nanoindentation measurements reveal that colloidal deposits with chain-like particles exhibit a smaller reduction in hardness compared to those reported using other cracking suppression approaches. This work demonstrates a promising technique for preparing colloidal coatings with enhanced crack resistance while maintaining desirable mechanical properties.

Diversity and functional prediction of fungal communities in different segments of mongolian horse gastrointestinal tracts.

BACKGROUND: Anaerobic fungi are effective fibre-degrading microorganisms in the digestive tract of horses. However, our understanding of their diversity and community structure is limited, especially in different parts of the gastrointestinal tract. RESULTS: For the first time, high-throughput sequencing technology was used to analyse and predict fungal microbial diversity in different parts of the gastrointestinal tract of Mongolian horses. The results revealed that the richness and diversity of fungi in the hindgut of Mongolian horses were much higher than those in the foregut. The foregut was dominated by Basidiomycota and Ascomycota, whereas the hindgut was dominated by Neocallimastigomycota and Basidiomycota. At the genus level, the relative abundance of many pathogenic fungi (Cryptococcus, Cladosporium, Alternaria, and Sarocladium) in the foregut was significantly higher than that in the posterior gut, indicating that Mongolian horses have strong disease resistance. The prediction of fungal function also showed significant differences in the fungal flora between the foregut and the hindgut. The fungi in Mongolian horses' foreguts were mainly pathologically nutritive and contained many animal and plant pathogens, particularly in the small intestine (jejunum and ileum). This indicates that the foregut may be the most important immune site in the digestive system of Mongolian horses, which explains the high disease resistance of Mongolian horses. The number of unassigned functional groups in the posterior gut was significantly higher than that in the anterior gut, indicating that the functions of fungal groups in the posterior gut have not been fully explored, and further studies are required in the future. CONCLUSIONS: Analysis of high-throughput sequencing results revealed that the fungal composition varied greatly among different gastrointestinal tract segments in Mongolian horses, whose hindgut contains many anaerobic fungi involved in plant cellulose degradation. This provides important basic data for studying fungal diversity in the digestive system of healthy horses, which can be used for the health assessment of horses and provides clues for further research on the disease resistance and digestive capacity of horses, as well as a reference for the early diagnosis of intestinal diseases and innovative treatment methods.

Flexible fabrication chitosan-polyamidoamine aerogels by one-step method for efficient adsorption and separation of anionic dyes.

Chitosan in situ grown polyamidoamine (CTS-Gx PAMAM (x = 0, 1, 2, 3)) aerogels were fabricated by a facile one-step freeze-drying method, with glutaraldehyde serving as a crosslinker. The three-dimensional skeletal structure of aerogel provided numerous adsorption sites and accelerated the effective mass transfer of pollutants. The adsorption kinetics and isotherm studies of the two anionic dyes were consistent with the pseudo-second-order and Langmuir models, indicating that the removal of rose bengal (RB) and sunset yellow (SY) was a monolayer chemisorption process. The maximum adsorption capacity of RB and SY reached 370.28 mg/g and 343.31 mg/g, respectively. After five adsorption-desorption cycles, the adsorption capacities of the two anionic dyes reached 81.10% and 84.06% of the initial adsorption capacities, respectively. The major mechanism between the aerogels and dyes was systematically investigated based on using Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and energy-dispersive spectroscopy analyses, confirming that electrostatic interaction, hydrogen bonding and van der Waals interactions were the main driving forces for the superior adsorption performance. Furthermore, the CTS-G2 PAMAM aerogel exhibited good filtration and separation performance. Overall, the novel aerogel adsorbent possesses excellent theoretical guidance and practical application potential for the purification of anionic dyes.

Plasmonic Hydrogen Sensors.

Hydrogen is regarded as the ultimate fuel and energy carrier with a high theoretical energy density and universality of sourcing. However, hydrogen is easy to leak and has a wide flammability range in air. For safely handling hydrogen, robust sensors are in high demand. Plasmonic hydrogen sensors (PHS) are attracting growing interest due to the advantages of high sensitivity, fast response speed, miniaturization, and high-degree of integration, etc. In this review, the mechanism and recent development (mainly after the year 2015) of hydrogen sensors based on plasmonic nanostructures are presented. The working principle of PHS is introduced. The sensing properties and the effects of resonance mode, configuration, material, and structure of the plasmonic nanostructures on the sensing performances are discussed. The merit and demerit of different types of plasmonic nanostructures are summarized and potential development directions are proposed. The aim of this review is not only to clarify the current strategies for PHS, but also to give a comprehensive understanding of the working principle of PHS, which may inspire more ingenious designs and execution of plasmonics for advanced hydrogen sensors.

Effect of travoprost, latanoprost and bimatoprost PGF2α treatments on the biomechanical properties of in-vivo rabbit cornea.

Prostaglandin F2α analogues (PGF2α), one of the most commonly prescribed classes of hypotensive agents, could decrease collagen fibril density and remodel the extracellular matrix in cornea. We hypothesized that PGF2α's would induce corneal softening, reduce the accuracy of intraocular pressure (IOP) measurement and lead to uncertainty in the effectiveness of the therapy. We determined the stress-strain behavior of rabbit cornea after PGF2α usage and evaluated the effect of biomechanical changes associated with PGF2α treatment on IOP measurements by Goldmann Applanation Tonometry (GAT). The tangent modulus decreased after PGF2α treatment, while the stromal interfibrillar spacing increased. PGF2α was shown to also affect the lateral eye with lower effect, which did not undergo direct eyedrop treatment. Significant decreases in the numerical predictions of GAT-IOP were predicted in all treated groups relative to control groups. Different PGF2α's (travoprost, latanoprost and bimatoprost) were associated with different extents of reduction in tissue stiffness and changes in corneal microstructure. PGF2α-induced changes in corneal mechanical properties could reduce the accuracy of IOP measurement and may cause an overestimation of the effect of PGF2α in lowering IOP, possibly leading to uncertainties in glaucoma management.

N-Oxide Zwitterion Functionalized Positively Charged Polyamide Composite Membranes for Nanofiltration.

N-Oxide zwitterionic polyethyleneimine (ZPEI), a new kind of aqueous phase monomer synthesized by commercially branched polyethyleneimine (PEI) via oxidation reaction, was prepared for fabrication of thin-film composite (TFC) polyamide membranes via interfacial polymerization. The main factors, including the monomer concentration and immersion time of the aqueous phase and organic phase, were investigated. Compared with PEI-TFC membranes, the obtained optimal defect-free ZPEI-TFC membranes exhibited a lower roughness (3.3 ± 0.3 nm), a better surface hydrophilicity, and a smaller pore size (238 Da of MWCO). The positively charged ZPEI-TFC membranes (isoelectric point at pH 8.05) showed higher rejections toward both divalent cationic (MgCl2, 93.0%) and anionic (Na2SO4, 96.1%) salts with a water permeation flux of up to 81.0 L·m-2·h-1 at 6 bar, which surpassed currently reported membranes. More importantly, mainly owing to N-oxide zwitterion with strong hydration capability, ZPEI-TFC membranes displayed a high flux recovery ratio (97.0%) toward a model protein contaminant (bovine serum albumin), indicating good anti-fouling properties. Therefore, the novel N-oxide zwitterion functionalized positively charged nanofiltration membranes provide an alternative for water desalination and sewage reclamation.

Volume Overlap Variation within Hyperbranched Polymer Brushes Resolves Topology Effects against Protein Fouling.

Hyperbranched polymer brushes with a three-dimensional dendritic structure are used in antifouling applications to obtain bioinert and compact dendritic structures. Though hyperbranched polyglycerol (HPG) is extensively utilized in the antifouling layer, there is still a lack of direct studies on the relationship between the interfacial properties and topology effect of hyperbranched polymer brushes. Here, we established the degree of chain volume overlap (Dv) to characterize the spatial shielding efficiency generated by HPG brushes and investigated the impact mechanism of the variable chain length on the interfacial physicochemical properties. The results revealed the Dv-relevant feature of performance that the most densely packed HPG brushes for a medium-length LHPG3.07 enable the functional surface to display optimal antifouling performance toward protein adsorption by forming the most effective space barrier and hydrated layer in appropriate molecular weights and graft density. Moreover, we clarified the advance of hyperbranched polymer brushes exhibited in topology effects for imparting surface-enhanced resistance to biofouling relies on the generable higher steric hindrance as compared with linear analogs. This study established a Dv-relevant evaluation model for acquiring an optimized antifouling surface based on the appropriate choice of polymer structure, topology morphologies, and grafting parameters.

Preparation of PAMAM modified PVDF membrane and its adsorption performance for copper ions.

As one of the main pollutants of water pollution, the potential toxicity of heavy metal ions always threatens the safety of human and nature. Therefore, how to effectively remove heavy metal ions has become an important research topic in environmental protection. In the existing research, adsorption method is outstanding from many methods because of its high adsorption efficiency and easy operation. In this study, different generations of hyperbranched polyamide-amine (PAMAM) were grafted onto PVDF membrane to obtain the membrane with high adsorption capacity for heavy metal ions. The structure and physicochemical properties of the membranes were evaluated by means of fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (FE-SEM), element analyzer and X-ray photoelectron spectroscopy (EDX). At the same time, various factors affecting the adsorption process were studied, and it was found that the adsorption behavior of copper ion (Cu2+) on the membrane conformed to the pseudo-first-order kinetic model and Langmuir isotherm model. Moreover, after comparing the adsorption effect of the modified membranes grafted with different generations of PAMAM, it was found that the membrane grafted with the third generation PAMAM had the best adsorption when the solution pH was 5, and its maximum adsorption capacity could reach 153.8 mg/g. After five adsorption-desorption cycles, its adsorption capacity can reach 72.83% of the first test, indicating that it has good recycling performance. The results show that the adsorption membrane has good application potential and research value.

Silver nanotriangle array based LSPR sensor for rapid coronavirus detection.

A rapid, portable, and cost-effective method to detect the infection of SARS-CoV-2 is fundamental toward mitigating the current COVID-19 pandemic. Herein, a human angiotensin-converting enzyme 2 protein (ACE2) functionalized silver nanotriangle (AgNT) array localized surface plasmon resonance (LSPR) sensor is developed for rapid coronavirus detection, which is validated by SARS-CoV-2 spike RBD protein and CoV NL63 virus with high sensitivity and specificity. A linear shift of the LSPR wavelength versus the logarithm of the concentration of the spike RBD protein and CoV NL63 is observed. The limits of detection for the spike RBD protein, CoV NL63 in buffer and untreated saliva are determined to be 0.83 pM, 391 PFU/mL, and 625 PFU/mL, respectively, while the detection time is found to be less than 20 min. Thus, the AgNT array optical sensor could serve as a potential rapid point-of-care COVID-19 diagnostic platform.

Bioresorbable Implants in Reduction of Paediatric Zygomaticomaxillary Complex Fractures Concurrent With Internal Orbital Reconstruction.

PURPOSE: To evaluate the clinical effectiveness and safety of bioresorbable implants for treating paediatric zygomaticomaxillary complex (ZMC) fractures with concomitant orbital floor defects. METHODS: A retrospective review of paediatric patients who underwent ZMC repair with concomitant orbital floor fractures with bioresorbable implants in Shanghai Ninth People's Hospital from July 2015 to June 2019 was performed. The primary outcome measures included ocular motility, diplopia, enophthalmos, facial deformities, and restricted mouth opening, as well as complication rates. Pre- and post-operative computed tomography scans were obtained for clinical diagnosis and surgical effectiveness. RESULTS: Twenty two children were included in this study. Facial deformities were corrected in all 22 cases by surgical reconstruction postoperatively, and the average relative distance of Portals point-Zygomaxillare and Anteriornasalspine-Zygomaxillare were 1.3 ± 0.6mm ( P = 0.22) and 1.2 ± 0.5mm ( P = 0.19). The eye movement restored to normal in 13 patients. The mean amount of relative enophthalmos was 1.0 ± 0.4 mm ( P = 0.12). 12 cases had complete resolution of diplopia postoperatively at the extremes of the gaze, and 1 case presented persistent diplopia on the down gaze as before, but from level III to level I. Facial numbness was resolved completely in 6 cases, and 2 cases presented with persistent numbness but relieved significantly. The average Hounsfield units of RapidSorb plates and OrbFloor PI were 154 ± 5 and 99 ± 4 respectively on computed tomography image obtained 1 week postoperatively, which showed no obvious difference compared with 0.5 year postoperatively ( P > 0.1). Hounsfield units of implants gradually declined around 1 year postoperatively. Hounsfield units of RapidSorb plates (20 ± 1) were consistent with periorbital tissue during postoperative 2-year follow-up, and Hounsfield units of OrbFloor PI (19 ± 1) were consistent with periorbital tissue during postoperative 1.5-year follow-up. No patients had severe sequelae or implant related complications postoperatively. None of bone nonunion, malunion, infection or rejection occurred during the follow-up periods. CONCLUSIONS: Open reduction and internal fixation for the treatment of ZMC fracture have achieved significant improvement in functional and cosmetic outcomes postoperatively. Bioresorbable materials have been proved to be effective and safe in the treatment of children's ZMC and orbital wall fractures.

Janus Particles with Flower-like Patches Prepared by Shadow Sphere Lithography.

A general strategy for generating various Janus particles (JPs) based on shadow sphere lithography (SSL) by varying incident and azimuthal angles, as well as deposition numbers is introduced, forming well-identified flower-like patches on microsphere monolayers. An in-house simulation program is worked out to predict the patch morphology with complicated fabrication parameters. The predicted patch morphology matches quite well that of experimentally produced JPs. The relationships between patch shape/area/size/and incident angle/deposition numbers are quantitatively determined by calculating morphology and transmission spectrum correlations, which facilitated further implementation of SSL in fabricating more varieties of JPs. Such an SSL strategy can be used to create JPs with anticipated patch morphology and uniformity that may be used for self-assembly, drug delivery, or plasmonic sensors as well as exploring some fundamental principles relating to the properties of nanostructures.

Hair follicle regional specificity in different parts of bay Mongolian horse by histology and transcriptional profiling.

BACKGROUND: Different morphological structures of hairs having properties like defense and camouflage help animals survive in the wild environment. Horse is one of the rare kinds of animals with complex hair phenotypes in one individual; however, knowledge of horse hair follicle is limited in literature and their molecular basis remains unclear. Therefore, the investigation of horse hair follicle morphogenesis and pigmentogenesis attracts considerable interest. RESULT: Histological studies revealed the morphology and pigment synthesis of hair follicles are different in between four different parts (mane, dorsal part, tail, and fetlock) of the bay Mongolian horse. Hair follicle size, density, and cycle are strongly associated with the activity of alkaline phosphatase (ALP). We observed a great difference in gene expression between the mane, tail, and fetlock, which had a greater different gene expression pattern compared with the dorsal part through transcriptomics. The development of the hair follicle in all four parts was related to angiogenesis, stem cells, Wnt, and IGF signaling pathways. Pigmentogenesis-related pathways were involved in their hair follicle pigment synthesis. CONCLUSIONS: Hair follicle morphology and the activity of ALP differ among four body parts in bay Mongolian horse. Hair follicles of the different body parts of the are not synchronized in their cycle stages. GO terms show a regional specificity pattern between different skin parts of the bay Mongolian horse. These results provide an insight into the understanding of the biological mechanism of the hair follicle in other mammals.

Transcriptome profiling of developing testes and spermatogenesis in the Mongolian horse.

BACKGROUND: Horse testis development and spermatogenesis are complex physiological processes. METHODS: To study these processes, three immature and three mature testes were collected from the Mongolian horse, and six libraries were established using high-throughput RNA sequencing technology (RNA-Seq) to screen for genes related to testis development and spermatogenesis. RESULTS: A total of 16,237 upregulated genes and 8,641 downregulated genes were detected in the testis of the Mongolian horse. These genes play important roles in different developmental stages of spermatogenesis and testicular development. Five genes with alternative splicing events that may influence spermatogenesis and development of the testis were detected. GO (Gene ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analyses were performed for functional annotation of the differentially expressed genes. Pathways related to "spermatogenesis," male gamete generation," "spermatid development" and "oocyte meiosis" were significantly involved in different stages of testis development and spermatogenesis. CONCLUSION: Genes, pathways and alternative splicing events were identified with inferred functions in the process of spermatogenesis in the Mongolian horse. The identification of these differentially expressed genetic signatures improves our understanding of horse testis development and spermatogenesis.

Discretized Motion of Surface Walker under a Nonuniform AC Magnetic Field.

The motion of peanut-shaped magnetic microrods (PSMRs) with different magnetic moment (Ms) orientations φM under a nonuniform AC magnetic field has been investigated systematically. When gradually changing φM from 90° (perpendicular to the long axis of the PSMR) to 0°, the motion of the PSMR evolves from rolling to precession, then to tumbling. Systematic investigations on the translational velocity vp versus the magnitude of the applied magnetic field B and the angular velocity ωB show that the overall motion of the PSMRs can be divided into four different zones: Brownian motion zone, synchronized zone, asynchronized zone, and oscillation zone. The vp-ωB relationship can be rescaled by a critical frequency ωc, which is determined by Ms, B, and a hydrodynamic term. An intrinsic quality factor qm for the translational motion of a magnetically driven micro-/nanomotor is defined and is found to range from 0.73 to 13.65 T-1 in the literature, while the Fe PSMRs in the current work give the highest qm (= 25.48 T-1). High speed movies reveal that both the tumbling and precession motions of the PSMRs have a discretized nature. At the instances when the magnetic field changes direction, the PSMR performs an instantaneous rotation and the strong hydrodynamic wall effect would impose a driving force to move the PSMR translationally, and about more than 60% of the time, the PSMR neither rotates nor moves translationally. Based on this discretized motion nature, an analytic expression for qm is found to be determined by the shape of the surface walker, the hydrodynamics near a wall, and the magnetic properties of the surface walker. This work can help us to better understand the motion of magnetic surface walkers and gain insight into designing better micro-/nanomotors.

Chondroitin sulfate hydrogels based on electrostatic interactions with enhanced adhesive properties: exploring the bulk and interfacial contributions.

Adhesive polysaccharide gels have highlighted their potential in biomedicine, tissue engineering, and wearable/implantable devices due to their tissue adhesive nature and excellent biocompatibility. However, the weak adhesive strength caused by the unclear relationship between the structure and the adhesive properties seriously hinders their further practical application. Here, a facile one-step synthesis method for adhesive and self-healing hydrogels with chondroitin sulfate (CS) and poly (methyl chloride quarternized N,N-dimethylamino ethylacrylate) (PDMAEA-Q) by ultraviolet light irradiation has been presented. We investigate the mechanism of the adhesion enhancement including improving the mechanical strength of gels (cohesion) and gel/substrate interfacial interactions (interfacial adhesion) by tailoring the compliance and cohesive energy density of the gel. The resultant soft and viscoelastic hydrogels displayed favorable adhesion ability on various substrates, and the adhesive strength to the iron substrate and porcine skin can reach 49.4 kPa and 15.4 kPa, respectively. Additionally, the gels also exhibited rapid self-healing properties and good cytocompatibility. We believe that the adhesive PDMAEA-Q/CS gel would be an ideal candidate for hydrogel glues for human-machine interfaces and biological tissues, and this design idea can open a new path for the preparation of adhesive polysaccharide hydrogels.

The IR plasmonic properties of sub-wavelength ITO rod arrays predicted by anisotropic effective medium theory.

Simple three-layer Fresnel equations combined with Maxwell-Garnett approximation were applied to study the IR plasmonic properties of indium-tin-oxide (ITO) nanorods. By treating the anisotropic nanorod layer as a layer with an effective dielectric constant, and using anisotropic effective medium theory, we were able to accurately predict the surface plasmon resonance behavior of ITO nanorods with different nanorod length, spacing, and tilt angle. This model allows a fast and computationally inexpensive calculation to predict the plasmonic properties of arrayed nanorods.