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Proton exchange membrane water electrolysis (PEMWE) is a very promising and sustainable hydrogen production technology. Currently, there is a growing interest in achieving ordered structures within membrane electrode assembly (MEA) for PEMWE. However, both ordered electron conductor and ordered proton conductor structures are single component structure, which still have many shortcomings. In this work, a hybrid ordered membrane electrodes assembly based on cone‐shaped is constructed Nafion array with rough surface by introducing TiO2 nanoparticles to Nafion emulsion. As a result, this hybrid ordered MEA achieves a high surface roughness of 3.39 nm that is 2.64 times higher than that of ordered MEA without TiO2 nanoparticles doped and current density up to 2.48 A cm−2 at 2 V with 14.4 µg cm−2 (Ir) catalyst loading. This work provides a new hybrid ordered structure for MEA and exhibits the great potential of enhancing the interfacial contact between the catalyst layer and Nafion membrane to improve PEMWE performance. [ABSTRACT FROM AUTHOR]

The wearable device industry is on the rise, with technology applications ranging from wireless communication technologies to the Internet of Things. However, most of the wearable sensors currently on the market are expensive, rigid and bulky, leading to poor data accuracy and uncomfortable wearing experiences. Near-field communication sensors are low-cost, easy-to-manufacture wireless communication technologies that are widely used in many fields, especially in the field of wearable electronic devices. The integration of wireless communication devices and sensors exhibits tremendous potential for these wearable applications by endowing sensors with new features of wireless signal transferring and conferring radio frequency identification or near-field communication devices with a sensing function. Likewise, the development of new materials and intensive research promotes the next generation of ultra-light and soft wearable devices for healthcare. This review begins with an introduction to the different components of near-field communication, with particular emphasis on the antenna design part of near-field communication. We summarize recent advances in different wearable areas of near-field communication sensors, including structural design, material selection, and the state of the art of scenario-based development. The challenges and opportunities relating to wearable near-field communication sensors for healthcare are also discussed. [ABSTRACT FROM AUTHOR]

In the present study, a novel composite nanogel based on fluorescence resonance energy transfer (FRET) and its application for photodynamic therapy is reported. First of all, nanoparticles of silica doped with Nile Red (NR) were prepared by Stöber method, then they were decorated by γ-methacryloxypropyltrimethoxysilane (MPS) to prepare MPS decorated NR@SiO2 nanoparticles, and finally they were copolymerized with N-isopropylacrylamide (NIPAm) and Pyropheophorbide-a (Ppa) by free radical copolymerization, and composite nanogel of NR@SiO2/PNIPAm-co-Ppa was fabricated. The microstructure of the as-prepared nanogel was characterized by Fourier transform infrared spectrum (FTIR), photoluminescence (PL), UV–Visible spectrophotometer (UV–Vis), dynamic light scattering (DLS) and transmission electron microscopy (TEM). PL spectrum indicated that, under irradiation of visible light source, energy can be transferred from NR to Ppa. UV–Vis spectrum demonstrated that aggregation of Ppa is prevented efficiently and Ppa exists as "monomer" state in the composite nanogel. Under irradiation of laser, singlet oxygen (1O2) can be produced efficiently by excited nanogel. The in vitro cytotoxicity test showed that HeLa cells can be killed by the composite nanogel. [ABSTRACT FROM AUTHOR]

In the present study, a novel nanogel of HPC-PMAA/PpIX with thermo- and pH sensitive performance and its application in cancer photodynamic therapy is reported. HPC-PMAA/PpIX nanogels were prepared by free radical polymerization method with HPC as template, hydroxypropyl cellulose (HPC), methyl acrylic acid (MAA), protoporphyrin IX (PpIX) and N,N′-methylene bisacrylamide (BIS) as raw materials. The as-prepared nanogels were characterized by Fourier transform infrared (FTIR), photoluminescence (PL) and UV–visible spectrophotometer (UV–vis), dynamic light scattering (DLS) and transmission electron microscopy (TEM). PL and UV–vis spectra demonstrate that PpIX is incorporated into HPC-PMAA by covalent bonds, and its aggregation is prevented. Moreover, the as-prepared nanogels can be dispersed in water over 1 week, significant singlet oxygen can be produced under irradiation of laser. With tumor cell of HepG2 as model cell, the nanogels are biocompatible with cell viability of >85% even at high concentrations of the PpIX in vitro. In addition, the HPC-PMAA/PpIX nanogels show photo-dependent toxicity in the concentration range of 10 µg/mL of PpIX, suggesting that HPC-PMAA/PpIX nanogels have potential for the treatment of photodynamic therapy (PDT). [ABSTRACT FROM AUTHOR]

In this paper, novel multi stimuli‐responsive complex nanogels of hydroxypropylcellulose (HPC)‐PAA/Eu(acrylic acid [AA])3Phen were synthesized by radical polymerization method with HPC, rare earth complex (Eu(AA)3Phen) and AA as raw materials, and the 3‐aminophenylboronic acid (3‐APBA) decorated nanogels (HPC‐PAAPBA/Eu(AA)3Phen) were fabricated via condensation of 1‐(3‐dimethylaminopropyl)‐3‐ethylcarbodiimide hydrochloride with 3‐APBA. The microstructure, morphology and diameter of the nanogel were characterized by Fourier transform infrared spectrometer, UV–Visible spectrophotometer, transmission electron microscope, dynamic light scattering. Moreover, the fluorescence responsive performance of complex nanogels to temperature, pH value and glucose concentration was investigated by photoluminescence spectroscopy. The results showed that both of the as‐prepared nanogels were uniform in size and had good monodispersity. The temperature and pH value had significant effects on the particle size and the fluorescence emission intensity of the HPC‐PAA/Eu(AA)3Phen complex nanogels; after decoration with 3‐APBA, the obtained HPC‐PAAPBA/Eu(AA)3Phen nanogels showed excellent stimulus‐response to glucose concentration. [ABSTRACT FROM AUTHOR]

In this study, a novel strategy for manipulating fluorescence emission of organic dyes is reported, which is based on coupling optical properties of colloidal crystals (CCs) with responsive microgels. Firstly, SiO2 microspheres doped with three kinds of organic dyes (Rhodamine B, RhB; fluorescein isothiocyanate, FITC; commercial cationic Fluorescent Yellow, X-10GFF) were prepared and they were used as the cores to synthesize SiO2/PNIPAm complex microgels doped with organic dyes by free radical polymerization. Then 3D self-assembled CCs of the complex microgels were fabricated by centrifugation. The microstructure of the complex microgel was characterized by Fourier transform infrared (FTIR), transmission electron microscopy (TEM), thermogravimetric (TG), dynamic light scattering (DLS), and differential scanning calorimeter (DSC). Moreover, the effect of doping organic dyes and temperature on self-assembly of the microgels were investigated. Manipulation of fluorescence emission for organic dyes by CCs was studied by photoluminescence (PL) and UV-visible spectrophotometer (UV-Vis). The results indicate that, due to the soft and thermosensitive property of PNIPAm shell, continuous adjustment to the photonic bandgap (PBG) of the CCs can be achieved conveniently by varying concentrations of the complex microgels or ambient temperatures, and when PBG of the CCs overlaps with the fluorescence emission peak of the organic dye, fluorescence emission of the organic dye can be manipulated. [ABSTRACT FROM AUTHOR]

This study investigates the state feedback control laws for Markov jump linear systems with state and mode‐observation delays. An assumption in this study is that the delay of the mode observation obeys an exponential distribution. Also, the authors raise an unknown time‐varying state delay applied in the composition of the state feedback controller. A method of remodelling the closed‐loop system as a standard Markov jump linear system with state delay is shown. Furthermore, on the basis of this remodelling, several linear matrix inequalities for designing feedback gains for stabilisation and mixed H2/H∞ control are proposed. Finally, the authors apply a numerical simulation for examining the effectiveness of the proposed mixed H2/H∞ controller designing method. [ABSTRACT FROM AUTHOR]

Background: Ocotillol, RT5 and F11, the main active components of ocotillol type ginsenosides, have attracted a lot of attention due to their beneficial effects on neurodegenerative disease models of Alzheimer's disease. Pharmacokinetic (PK) is a bridge linking the herbal medicines and their pharmacological responses. However, few data are available regarding PK behaviors of ocotillol type ginsenosides. Methods: The liquid chromatography-tandem mass spectrometry methods were developed and validated to calculate the concentrations of 3 ginsenosides in different biological matrices. Rat and beagle dog plasma samples were deproteinized with methanol and separated on Shim-pack GIST C18 column. All of the analytes were detected in positive ion mode using multiple reaction monitoring. Results: The methods showed good linearity (r > 0.996) in the established concentration range. All validated data, such as specificity, intra- and inter-day precision, accuracy, extraction recovery, matrix effect, and stability were within required limits. The values of Cmax and AUC(0–t) indicated ocotillol type ginsenosides had low systemic exposure and poor absorption into blood. T1/2 and MRT(0–t) demonstrated the elimination process of ocotillol type ginsenosides might be slow. Double peaks were observed in the mean plasma concentration versus time profiles of ocotillol, RT5, and F11 after oral intake. Conclusions: This was the first PK investigation of the ocotillol type ginsenosides in rats and beagle dogs. The results we found here were helpful to our understanding of the absorption mechanism of ocotillol type ginsenosides and provided the scientific basis for further pre-clinical research. [ABSTRACT FROM AUTHOR]

Costunolide, a sesquiterpene lactone, a small molecular monomer extracted from Inula helenium, has been reported to possess antiproliferative effects on several cancer cell lines. The current study was designed to evaluate the effect of costunolide on sensitivity of K562/ADR chronic myeloid leukemia cells to doxorubicin. The antiproliferative effect of costunolide was assessed by CCK-8 assay. Flow cytometry and Western blot were used to examine the mechanisms of antileukemia action. Costunolide dramatically enhanced doxorubicin-induced antiproliferative activity against K562/ADR cells through inhibition of PI3K/Akt pathway, activation of caspases 3, cleavage of poly (ADP-ribose) polymerase, and downregulation of p-glycoprotein expression. These results demonstrate that costunolide may be a potent therapeutic agent against CML. [ABSTRACT FROM AUTHOR]

A single fluorescent signal output often does not satisfy the detection accuracy requirements for bioactive compounds in biological systems. It is of great interest to develop a dual-channel turn-on fluorescence sensing system for self-validated detection. Herein, we report a self-quenching nanoparticle composed of dual two-photon dyes of naphthalimides, displaying almost no fluorescence at both channels, owing to aggregation-caused quenching (ACQ). A dual two-photon-channel fluorescent probe for GSH was further developed by inserting a disulfide bond between two naphthalimides. Upon treatment with GSH, the disulfide bond was cleaved, and two napthalimide fluorophores were separated, leading to turn-on fluorescence at both channels. This dual-two-photon-channel design strategy can be easily extended to other analytes, simply by changing the linker molecules, which creates new opportunities to accurately monitor various biological processes in living cells. [ABSTRACT FROM AUTHOR]

Density functional study have been carried out to investigate the stereoselectivities in the Mannich-type reactions promoted by five typical amino acid catalysts with different scaffolds. The reverse diastereoselectivities in the cyclic and acyclic α- and β-amino acids-promoted Mannich reactions have been satisfactorily explained by the density functional theory (DFT) methods at the SMD/M06-2X/6-31G** computational level. The activation strain analysis has been used to account for the selectivity-switching for these selected bifunctional catalysts. © 2015 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Highlights: [•] We perform DFT study of aldol and Mannich reactions involving special electrophiles. [•] Opposite diastereoseletivities are reproduced for two secondary amine catalysts. [•] Origin of selectivity is due to different distance between amino and acid moiety. [ABSTRACT FROM AUTHOR]

Thechemo-, diastereo-, and enantioselectivities in proline and axiallychiral amino sulfonamide-catalyzed direct aldol reactions betweentwo enolizable aldehydes with different electronic nature have beenstudied with the aid of density functional theory (DFT) method. Thepotential energy profiles for the enamine formation between each aliphaticaldehyde and the catalyst confirm that two subject catalysts can successfullydifferentiate between 3-methylbutanal as an enamine component andα-chloroaldehydes as a carbonyl component. Transition statesassociated with the stereochemistry-determining C–C bond-formingstep with the enamine intermediate addition to the aldehyde acceptorfor proline and chiral amino sulfonamide-promoted aldol reactionsare reported. DFT calculations not only provide a good explanationfor the formation of the sole cross-aldol product between two aliphaticaldehydes both bearing α-methylene protons but also well reproducethe opposite syn vs anti diastereoselectivities in the chiral aminosulfonamide and proline-catalyzed aldol reactions. [ABSTRACT FROM AUTHOR]

The resilience and strength of bone is due to the orderly mineralization of a specialized extracellular matrix (ECM) composed of type I collagen (90%) and a host of non-collagenous proteins that are, in general, also found in other tissues. Biglycan (encoded by the gene Bgn) is an ECM proteoglycan that is enriched in bone and other non-skeletal connective tissues. In vitro studies indicate that Bgn may function in connective tissue metabolism by binding to collagen fibrils and TGF-ß (Refs 5,6), and may promote neuronal survival. To study the role of Bgn in vivo, we generated Bgn-deficient mice. Although apparently normal at birth, these mice display a phenotype characterized by a reduced growth rate and decreased bone mass due to the absence of Bgn. To our knowledge, this is the first report in which deficiency of a non-collagenous ECM protein leads to a skeletal phenotype that is marked by low bone mass that becomes more obvious with age. These mice may serve as an animal model to study the role of ECM proteins in osteoporosis. [ABSTRACT FROM AUTHOR]

Developing stable and efficient photothermal agents (PTAs) for the second near-infrared window (NIR-II, 1 000-1700 nm) photothermal therapy (PTT) is highly desirable but remains challenging. Herein, a facile strategy to prepare NIR-II nano-PTA based on the ionic N-doped nanographene hexapyrrolohexaazacoronene (HPHAC) is reported featuring a specific orbicular-donor-acceptor (O-D-A) structure. Oxidizing HPHAC 1 to dication 1 2+ causes a substantial decrease in its band gap, leading to a shift in absorption from the confined UV region to a broad absorption range that reaches up to 1400 nm. The dication 1 2+ exhibits global aromaticity and excellent stability. Theoretical investigation demonstrates that the strong NIR-II absorption of 1 2+ is attributed to a distinct inner-to-outer intramolecular charge transfer. Encapsulating 1 2+ with amphiphilic polymers results in water-soluble 1 2+ NPs with retained optical characteristics. The 1 2+ NPs exhibit exceptional biocompatibility, intense photoacoustic responses, and a high photothermal conversion efficiency of 72% under the 1064 nm laser irradiation, enabling efficient PTT of cancer cells. The "O-D-A" system on HPHAC, which is created by a simple redox approach, provides a novel strategy to construct efficient NIR-II photothermal materials through molecular engineering of nanographenes., (© 2024 Wiley‐VCH GmbH.)

Previously, we showed that substitution of HIV-1 Env residue 375-Ser by bulky aromatic residues enhances binding to rhesus CD4 and enables primary HIV-1 Envs to support efficient replication as simian-human immunodeficiency virus (SHIV) chimeras in rhesus macaques (RMs). Here, we test this design strategy more broadly by constructing SHIVs containing ten primary Envs corresponding to HIV-1 subtypes A, B, C, AE and AG. All ten SHIVs bearing wildtype Env375 residues replicated efficiently in human CD4 + T cells, but only one replicated efficiently in primary rhesus cells. This was a subtype AE SHIV that naturally contained His at Env375. Replacement of wildtype Env375 residues by Trp, Tyr, Phe or His in the other nine SHIVs led to efficient replication in rhesus CD4+ T cells in vitro and in vivo Nine SHIVs containing optimized Env375 alleles were grown large-scale in primary rhesus CD4 + T cells to serve as challenge stocks in preclinical prevention trials. These virus stocks were genetically homogeneous, native-like in Env antigenicity and tier-2 neutralization sensitivity, and transmissible by rectal, vaginal, penile, oral or intravenous routes. To facilitate future SHIV constructions, we engineered a simplified second-generation design scheme and validated it in RMs. Overall, our findings demonstrate that SHIVs bearing primary Envs with bulky aromatic substitutions at Env375 consistently replicate in RMs, recapitulating many features of HIV-1 infection in humans. Such SHIVs are efficiently transmitted by mucosal routes common to HIV-1 infection and can be used to test vaccine efficacy in preclinical monkey trials. Importance SHIV infection of Indian rhesus macaques is an important animal model for studying HIV-1 transmission, prevention, immunopathogenesis and cure. Such research is timely, given recent progress with active and passive immunization and novel approaches to HIV-1 cure. Given the multifaceted roles of HIV-1 Env in cell tropism and virus entry, and as a target for neutralizing and non-neutralizing antibodies, Envs selected for SHIV construction are of paramount importance. Until recently, it has been impossible to strategically design SHIVs bearing clinically relevant Envs that replicate consistently in monkeys. This changed with the discovery that bulky aromatic substitutions at residue Env375 confer enhanced affinity to rhesus CD4. Here, we show that 10 new SHIVs bearing primary HIV-1 Envs with residue 375 substitutions replicated efficiently in RMs and could be transmitted efficiently across rectal, vaginal, penile and oral mucosa. These findings suggest an expanded role for SHIVs as a model of HIV-1 infection., (Copyright © 2021 Li et al.)

Neutralizing antibodies elicited by HIV-1 coevolve with viral envelope proteins (Env) in distinctive patterns, in some cases acquiring substantial breadth. We report that primary HIV-1 envelope proteins-when expressed by simian-human immunodeficiency viruses in rhesus macaques-elicited patterns of Env-antibody coevolution very similar to those in humans, including conserved immunogenetic, structural, and chemical solutions to epitope recognition and precise Env-amino acid substitutions, insertions, and deletions leading to virus persistence. The structure of one rhesus antibody, capable of neutralizing 49% of a 208-strain panel, revealed a V2 apex mode of recognition like that of human broadly neutralizing antibodies (bNAbs) PGT145 and PCT64-35S. Another rhesus antibody bound the CD4 binding site by CD4 mimicry, mirroring human bNAbs 8ANC131, CH235, and VRC01. Virus-antibody coevolution in macaques can thus recapitulate developmental features of human bNAbs, thereby guiding HIV-1 immunogen design., (Copyright © 2021, American Association for the Advancement of Science.)

Objective: To investigate the clinical effect of ambroxol in the treatment of asthmatic bronchitis., Methods: One hundred and twenty patients with asthmatic bronchitis who were admitted to our hospital from June 2017 to August 2018 were selected as the research subjects and divided into a control group and an observation group according to random number table method, 60 in each group. The control group was treated with conventional treatment, while the observation group was treated with ambroxol in addition to conventional treatment. The therapeutic effect, disappearance time of symptoms and signs and the recovery of pulmonary function were compared between the two groups., Results: The total effective rate of the observation group was 96.7%, and that of the control group was 73.3%. The control effect of the observation group was significantly better than that of the control group, showing a significant difference (P<0.05). The disappearance time of symptoms of the observation group was shorter than that of the control group, and the recovery of pulmonary function was better; the differences were statistically significant (P<0.05)., Conclusion: For asthmatic bronchitis patients, addition of ambroxol to conventional treatment can improve the therapeutic effect, shorten the disappearance time of clinical signs and symptoms, and promote the recovery of patients, which is worth clinical application., (Copyright: © Pakistan Journal of Medical Sciences.)

Background: Ocotillol, RT5 and F11, the main active components of ocotillol type ginsenosides, have attracted a lot of attention due to their beneficial effects on neurodegenerative disease models of Alzheimer's disease. Pharmacokinetic (PK) is a bridge linking the herbal medicines and their pharmacological responses. However, few data are available regarding PK behaviors of ocotillol type ginsenosides., Methods: The liquid chromatography-tandem mass spectrometry methods were developed and validated to calculate the concentrations of 3 ginsenosides in different biological matrices. Rat and beagle dog plasma samples were deproteinized with methanol and separated on Shim-pack GIST C18 column. All of the analytes were detected in positive ion mode using multiple reaction monitoring., Results: The methods showed good linearity (r > 0.996) in the established concentration range. All validated data, such as specificity, intra- and inter-day precision, accuracy, extraction recovery, matrix effect, and stability were within required limits. The values of Cmax and AUC(0-t) indicated ocotillol type ginsenosides had low systemic exposure and poor absorption into blood. T1/2 and MRT(0-t) demonstrated the elimination process of ocotillol type ginsenosides might be slow. Double peaks were observed in the mean plasma concentration versus time profiles of ocotillol, RT5, and F11 after oral intake., Conclusions: This was the first PK investigation of the ocotillol type ginsenosides in rats and beagle dogs. The results we found here were helpful to our understanding of the absorption mechanism of ocotillol type ginsenosides and provided the scientific basis for further pre-clinical research., (© 2019 S. Karger AG, Basel.)

A single fluorescent signal output often does not satisfy the detection accuracy requirements for bioactive compounds in biological systems. It is of great interest to develop a dual-channel turn-on fluorescence sensing system for self-validated detection. Herein, we report a self-quenching nanoparticle composed of dual two-photon dyes of naphthalimides, displaying almost no fluorescence at both channels, owing to aggregation-caused quenching (ACQ). A dual two-photon-channel fluorescent probe for GSH was further developed by inserting a disulfide bond between two naphthalimides. Upon treatment with GSH, the disulfide bond was cleaved, and two napthalimide fluorophores were separated, leading to turn-on fluorescence at both channels. This dual-two-photon-channel design strategy can be easily extended to other analytes, simply by changing the linker molecules, which creates new opportunities to accurately monitor various biological processes in living cells., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Multi-threshold image segmentation is a powerful image processing technique that is used for the preprocessing of pattern recognition and computer vision. However, traditional multilevel thresholding methods are computationally expensive because they involve exhaustively searching the optimal thresholds to optimize the objective functions. To overcome this drawback, this paper proposes a flower pollination algorithm with a randomized location modification. The proposed algorithm is used to find optimal threshold values for maximizing Otsu's objective functions with regard to eight medical grayscale images. When benchmarked against other state-of-the-art evolutionary algorithms, the new algorithm proves itself to be robust and effective through numerical experimental results including Otsu's objective values and standard deviations.