Research advances on encapsulation of probiotics with nanomaterials and their repair mechanisms on intestinal barriers

Probiotics participate in various physiological activities and contribute to body health.However,their viability and bioefficacy are adversely affected by gastrointestinal harsh conditions,such as gastric acid,bile salts and various enzymes.Fortunately,encapsulation based on various nanomaterials shows tremendous potential to protect probiotics.In this review,we introduced some novel encapsulation technologies involving nanomaterials in view of predesigned stability and viability,selective adhesion,smart release and colonization,and efficacy exertion of encapsulated probiotics.Furthermore,the interactions between encapsulated probiotics and the gastrointestinal tract were summarized and analyzed,with highlighting the regulatory mechanisms of encapsulated probiotics on intestinal mechanical barrier,chemical barrier,biological barrier and immune barrier.This review would benefit the food and pharmaceutical industries in preparation and utilization of multifunctional encapsulated probiotics.

EphA3 deficiency in the hypothalamus promotes high-fat diet-induced obesity in mice

Erythropoietin-producing hepatocellular carcinoma A3(EphA3)is a member of the largest subfamily of tyrosine kinase receptors-Eph receptors.Previous studies have shown that EphA3 is associated with tissue development.Recently,we have found that the expression of EphA3 is elevated in the hypothalamus of mice with diet-induced obesity(DIO).However,the role of EphA3 in hypothalamic-controlled energy metabolism remains unclear.In the current study,we demonstrated that the deletion of EphA3 in the hypothalamus by CRISPR/Cas9-mediated gene editing promotes obesity in male mice with high-fat diet feeding rather than those with normal chow diet feeding.Moreover,the deletion of hypothalamic EphA3 promotes high-fat DIO by increasing food intake and reducing energy expenditure.Knockdown of EphA3 leads to smaller intracellular vesicles in GT1-7 cells.The current study reveals that hypothalamic EphA3 plays important roles in promoting DIO.

A Review on Strengthening of Timber Beams Using Fiber Reinforced Polymers

Fiber reinforced polymer(FRP)has been used in the construction industry because of its advantages such as high strength,light weight,corrosion resistance,low density and high elasticity.This paper presents a review of bonding techniques adopted to strengthen timber beams using FRP to achieve larger spans.Different methods of bonding between FRP and timber beams have been summarized with a focus on the influencing factors and their effects as well as relevant bond-slip models proposed for fundamental understanding.Experimental investigations to evaluate the flexural performance of timber beams strengthened by FRP bars,sheets and wraps have also been critically reviewed to identify key influencing parameters.Limited research available on the shear performance of FRP reinforced timber beams have been analyzed to determine the influencing factors of the shear performance in timber-FRP beams.The paper finally presents an overall summary of the current-state-of-the-art and proposes some future research directions in the field.

Mild stir-assisted membrane dispersion for enhancing propionic acid extraction

Mild stir-assisted membrane dispersion extraction(MDE) method was employed to enhance propionic acid(HA)extraction and compared to the mechanical stirred extraction(MSE) method. Triocylamine(TOA) and tributyl phosphate(TBP) were chosen as model extractant to extract HA. Firstly, droplet size and the size distribution of organic phase were analyzed, and then the effects of phase ratio, extractant and HA concentration on extraction performance were investigated. Comparing the two extraction methods, the results show mild stir-assisted MDE method reduced the mass transfer equilibrium time compared to MSE method. The mass transfer mechanism was explored by analyzing mass transfer resistance. Mild stir-assisted MDE had less total mass transfer resistance than MSE. When the extractant concentration was 40%, the extraction process was controlled by organic phase mass transfer process with HA volume fraction was 1% and controlled by both of reaction process and organic phase mass transfer process when HA concentration increased to 5%. This work may provide a new type of extraction method for the recovery of organic carboxylic acid.

Application of Five-in-One Community Management Mode plus Wuhan’s Regional WeChat Platform in the Novel Coronavirus Control

In this study, the five-in-one community mass prevention and mass treatment group established in Wuhan to curb novel coronavirus outbreak in 2019 to 2020 is introduced. Various public health propaganda methods are used, including community loudspeakers and community bulletin boards. In the meantime, WeChat platform account named “Wuhan neighborhood on WeChat” is registered and opened, and a Group Chat on WeChat is created for grid management. A diversity of on-line and off-line countermeasures against the novel coronavirus outbreak are implemented via the WeChat platform: three-early measures (early discovery, early reporting, and early treatment), centralized management, community-based reporting, hierarchical diagnosis, and treatment system, isolation of mild patients at designated facilities, diagnosis and treatment appointment system for patients with fever, patient transferral in special vehicles, terminal disinfection at homes, psychological support and daily caring plan for special populations. This WeChat platform allows for an all-region, all-around, all-time and entire population-coverage control of novel coronavirus outbreak, with the extension and strengthening of health propaganda, guidance for seeking medical assistance, mass prevention and mass treatment, and health self-management among the community residents. Great effect has been achieved in novel coronavirus control so far. The five-in-one community management mode of Wuhan plus “Wuhan neighborhood on WeChat” plays an important role in relieving the shortage of health service resources and resolving the problem of limited service scope of professional medical staff in Wuhan, and ultimately contributes to the overall novel coronavirus control.

Multifunctional hydrogel combined with electrical stimulation therapy for promoting diabetic wound healing

Diabetic wounds, as a complication of diabetes, are slow to heal and seriously affect the quality of life of patients. Functional hydrogel dressing is an effective approach to improve diabetic wound healing. Electrical stimulation (ES) therapy is conducive to promoting cell migration and wound healing. In this work, a multifunctional PPTZ hydrogel wound dressing was developed by freeze-thaw method with polyvinyl alcohol (PVA), phytic acid (PA), tannic acid (TA), and Zinc chloride. The obtained PPTZ hydrogel has good mechanical properties (stress and strain of 700.03 kPa and 575.08%), light transmittance (close to 100%) and antibacterial rate (over 75%). With good biocompatibility, antioxidant abilities and conductivity, the PPTZ hydrogel could effectively promote the healing of diabetic wounds with two weeks under the action of electric field, which provides an auxiliary treatment strategy for diabetic patients.

Unveiling size-fluorescence correlation of organic nanoparticles and its use in nanoparticle size determination

Quantitatively establishing the correlation between nanoparticle size and fluorescence is essential for understanding the behavior and functionality of fluorescent nanoparticles(FNPs).However,such exploration focusing on organic FNPs has not been achieved to date.Herein,we employ the use of supramolecular polymeric FNPs prepared from tetraphenylethylene-based bis-ureidopyrimidinone monomers(bis-UPys)to relate the size to the fluorescence of organic nanoparticles.At an equal concentration of bis-UPys,a logarithmic relationship between them is built with a correlation coefficient higher than 0.96.Theoretical calculations indicate that variations in fluorescence intensity among FNPs of different sizes are attributed to the distinct molecular packing environments at the surface and within the interior of the nanoparticles.This leads to different nonradiative decay rates of the embedded and exposed bis-UPys and thereby changes the overall fluorescence quantum yield of nanoparticles due to their different specific surface areas.The established fluorescence intensity-size correlation possesses fine universality and reliability,and it is successfully utilized to estimate the sizes of other nanoparticles,including those in highly diluted dispersions of FNPs.This work paves a new way for the simple and real-time determination of nanoparticle sizes and offers an attractive paradigm to optimize nanoparticle functionalities by the size effect.

A head-mounted photoacoustic fiberscope for hemodynamic imaging in mobile mice

A miniaturized photoacoustic fiberscope has been developed, featuring a lateral resolution of 9 microns and a lightweight design at 4.5 grams. Engineered to capture hemodynamic processes at single-blood-vessel resolution at a rate of 0.2 Hz, this device represents an advancement in head-mounted tools for exploring intricate brain activities in mobile animals.

Antimicrobial hydrogel with multiple pH-responsiveness for infected burn wound healing

Burns are a common medical problem globally,and wound infection is one of the major causes of inducing related complications.Although antibiotics effectively prevent wound infections,the misuse of antibiotics has created a new problem of superbugs.Herein,we propose a new strategy to obtain pH-responsive antimicrobial P-ZIF(ZIF:zeolitic imidazolate framework)by loading polyhexamethylenebiguanide(PHMB)into the framework of ZIF-8 nanoparticles.This will enable PHMB to be released in the weak acid environment of an infected wound.To address burn infections,P-ZIF nanoparticles were loaded into a hydrogel system made of sodium alginate(SA)and 3-aminophenylboronic acid modified human-like collagen(H-A)through borate ester bonds.The resulting H-A/SA/P-ZIF(HASPZ)hydrogel dressing not only possesses antibacterial and wound healing properties but also has dual pH responsiveness to prevent the overuse of medication while effectively treat deep second-degree burns.Therefore,P-ZIF nanoparticles and the corresponding HASPZ hydrogel dressing are considered of significant importance in antimicrobial,drug delivery,and wound repair.

A scaffold with zinc-whitlockite nanoparticles accelerates bone reconstruction by promoting bone differentiation and angiogenesis

The therapy of bone defects based on advanced biological scaffolds offers the most promising therapeutic strategy for bone reconstruction.It is still challenging to develop scaffolds with the mechanical,osteogenic,angiogenic,and antibacterial properties required for bone defect reconstruction.Here,a novel organic/inorganic composite scaffold(zinc-whitlockite(ZnWH)/G/H)was synthesized using gellan gum(GG),human-like collagen(HLC),and ZnWH nanoparticles.The scaffold had excellent mechanical properties,adjustable swelling ratio,and interconnected pore structure.In addition to its excellent biocompatibility,it could promote osteogenic differentiation by releasing ZnWH nanoparticles to stimulate human bone marrow mesenchymal stem cells(hBMSCs)to upregulate the levels of alkaline phosphatase(ALP),osteocalcin(OCN),and osteopontin(OPN).In addition,this study showed that ZnWH nanoparticles could also promote angiogenesis by upregulating the paracrine secretion of vascular endothelial growth factor(VEGF)in hBMSCs.At the same time,the scaffold could inhibit the proliferation of bacteria.After 12 weeks of treatment in the rabbit femoral defect model,the ZnWH/G/H scaffold significantly accelerated the process of bone reconstruction.Therefore,these results demonstrate that the prepared novel nanocomposite scaffold,ZnWH/G/H,offers a promising candidate for bone regeneration.

Ce and Se co-doped MBG/SA/HLC microgel bone powder for repairing tumor bone defects

The repair and treatment of tumor bone defects is a difficult problem to solve urgently in clinical medicine.After tumor resection,patients are not only faced with a large area of bone defect,but also may have the risk of tumor recurrence,which can easily cause huge physical and mental harm to patients.In this study,we successfully designed and constructed an organic/inorganic composite microgel bone powder(S-H-M3%Ce/3%Se)based on cerium(Ce)and selenium(Se)elements co-doped mesoporous bioactive glass(M3%Ce/3%Se),sodium alginate(SA),and recombinant human-like collagen(HLC).The obtained S-H-M3%Ce/3%Se could inhibit the growth of osteoma cells and promote the growth of normal cells,and effectively promote the repair of defect bone.The integration of the“treatment and repair”organic/inorganic composite microgel bone powder provided a new strategy for the treatment of cancerous bone defects.

Wide-range color-tunable afterglow emission by the modulation of triplet exciton transition processes based on buckybowl structure

Buckybowl structures as non-uniform electrostatic potential distributions of poly-cyclic aromatic materials show a unique photoelectric performance.In this work,OTC was utilized for dynamic modulation of triplet exciton transition processes.Five host molecules with different functional units were selected,thus providing dif-ferent intermolecular interactions in the host/guest systems.Therefore,the delayed emissions were regulated from 536 to 624 nm via the tuning of the triplet exciton transition processes of OTC in different hosts.Experimental data and theoretical calculations revealed that the varied triplet transition behaviors resulted from the competition between the intersystem crossing(ISC)process of OTC-monomer and the reverse intersystem crossing(RISC)process of OTC-aggregates.This work proves the superior structure of buckybowl-based luminophore for controlling triplet exciton transition processes and supplies a new perspective for persistent afterglow luminophore design.

共热解法制备方解石/生物炭复合材料及其吸附Pb(II)性能和机制

为了制备一种高效吸附含Pb(II)废水的生物炭材料,以椰壳(CS)和方解石(CAL)为原料,采用共热解法分别在500℃、600℃、700℃制备了方解石/生物炭(CAL/BC)复合材料。通过SEM、ICP-MS、BET、XRD、FTIR等方法对CAL/BC复合材料的表面微观形态和结构进行了表征。结果发现,三种热解温度条件下,CAL均能够与CS紧密结合,而且CAL/BC具有较大的比表面积,表面含有丰富的官能团。批量吸附实验结果表明,CAL和CS质量比为1∶2,pH值为5.5,吸附剂添加量为1.5 g·L^(−1),此时CAL/BC复合材料对Pb(II)的吸附量分别为95.24 mg·g^(−1)(500℃)、99.01 mg·g^(−1)(600℃)、185.19 mg·g^(−1)(700℃),可见热解温度为700℃时,吸附效果最佳。吸附过程符合二级动力学模型和Langmuir等温线模型。CAL/BC复合材料吸附Pb(II)的主要机制是沉淀、离子交换、阳离子-π作用、孔隙填充和静电引力。此外,CAL/BC复合材料在4次吸附-解吸循环后仍能保持较高的Pb(II)去除率。因此,共热解法制备的CAL/BC复合材料在处理废水中的Pb(II)方面具有广阔的应用前景。

两亲性体系自组装机制的多尺度模拟及动力学网络模型分析

两亲性构筑基元自组装在制备纳米功能材料中有着不可替代的重要性.在微观和介观尺度上对自组装过程内在机制的认识对实现纳米自组装结构的精准调控起着关键作用.多尺度模拟可实现在微观和介观尺度上对构筑基元自组装过程的动力学模拟,获取亚稳态、稳态的组装构型及动力学轨迹.基于所得动力学轨迹,可进一步构建动力学网络模型,获得自组装过程的动力学转移路径,为设计新的自组装构筑基元和调控自组装结构提供理论依据.本文主要综述了我们近期通过多尺度模拟结合动力学网络模型分析来研究两亲性构筑基元(如有机小分子、嵌段共聚物和补丁粒子)自组装内在机理方面的研究进展.

Comparative Study of ROCK1 and ROCK2 in Hippocampal Spine Formation and Synaptic Function

Rho-associated kinases(ROCKs)are serinethreonine protein kinases that act downstream of small Rho GTPases to regulate the dynamics of the actin cytoskeleton.Two ROCK isoforms(ROCK1 and ROCK2)are expressed in the mammalian central nervous system.Although ROCK activity has been implicated in synapse formation,whether the distinct ROCK isoforms have different roles in synapse formation and function in vivo is not clear.Here,we used a genetic approach to address this long-standing question.Both Rock1^+/- and Rock2^+/- mice had impaired glutamatergic transmission,reduced spine density,and fewer excitatory synapses in hippocampal CA1 pyramidal neurons.In addition,both Rockl^+/- and Rock2^+/- mice showed deficits in long-term potentiation at hippocampal CA1 synapses and were impaired in spatial learning and memory based on the water maze and contextual fear conditioning tests.However,the spine morphology of CA1 pyramidal neurons was altered only in Rock2^+/- but not Rock1^+/- mice.In this study we compared the roles of ROCK1 and ROCK2 in synapse formation and function in vivo for the first time.Our results provide a better understanding of the functions of distinct ROCK isoforms in synapse formation and function.

A temperature responsive adhesive hydrogel for fabrication of flexible electronic sensors

Flexible electronics are playing an increasingly important role in human health monitoring and healthcare diagnosis.Strong adhesion on human tissue would be ideal for reducing interface resistance and motion artifacts,but arising problems such as skin irritation,rubefaction,and pain upon device removal have hampered their utility.Here,inspired by the temperature reversibility of hydrogen bonding,a skin-friendly conductive hydrogel with multiple-hydrogen bonds was designed by using biocompatible poly(vinyl alcohol)(PVA),phytic acid(PA),and gelatin(Gel).The obtained PVA/PA/Gel(PPG)hydrogel with temperature-triggered tunable mechanic could reliably adhere to skin and detect electrophysiological signals under a hot compress while be readily removed under a cool compress.Furthermore,the additional advantages of transparency,breathability,and antimicrobial activity of the PPG hydrogel ensure its long-time wearable value on the skin.It is both environmentally friendly and cost saving for the waste PPG hydrogel during production can be recycled based on their reversible physical bonding.The PPG hydrogel sensor is expected to have good application prospects to record electrophysiological signals in human health monitoring.

Ultralong organic room-temperature phosphorescence of electrondonating and commercially available host and guest molecules through efficient Förster resonance energy transfer

Ultralong organic room-temperature phosphorescence(RTP)materials have attracted tremendous attention recently due to their diverse applications.Several ultralong organic RTP materials mimicking the host-guest architecture of inorganic systems have been exploited successfully.However,complicated synthesis and high expenditure are still inevitable in these studies.Herein,we develop a series of novel host-guest organic phosphorescence systems,in which all luminophores are electron-rich,commercially available and halogen-atom-free.The maximum phosphorescence efficiency and the longest lifetime could reach 23.6%and 362 ms,respectively.Experimental results and theoretical calculation indicate that the host molecules not only play a vital role in providing a rigid environment to suppress non-radiative decay of the guest,but also show a synergistic effect to the guest through Förster resonance energy transfer(FRET).The commercial availability,facile preparation and unique properties also make these new host-guest materials an excellent candidate for the anti-counterfeiting application.This work will inspire researchers to develop new RTP systems with different wavelengths from commercially available luminophores.

Donor strategy for promoting nonradiative decay to achieve an efficient photothermal therapy for treating cancer

Photothermal therapy(PTT)is emerging as an effective treatment for superficial carcinoma.A key challenge to the effectiveness of PTT is to develop photosensitizers with high photothermal conversion efficiency.Aiming to address this challenge,we develop a series of multi-arylpyrrole derivatives with different donors that contain different multi-rotor structures to explore highly efficient PTT photosensitizers.Among these multi-arylpyrrole derivatives,MAP4-FE nanoparticles with a small size of their donor groups and better-donating ability exhibit a high photothermal conversion efficiency(up to 72%)when they are encapsulated by an amphiphilic polymer.As a result,the MAP4-FE nanoparticles have shown satisfactory PTTeffects on in vivo tumor eradication under the guidance of photoacoustic signals.The findings of this study provide significant insights for the development of high-efficiency PTT photosensitizers for cancer treatment by making full use of the nonradiative decay of small size donors as rotors.

Biochemical responses of the freshwater microalga Dictyosphaerium sp. upon exposure to three sulfonamides

Sulfonamides(SAs)are common antimicrobial drugs,which are frequently detected in surface water systems,and are difficult to degrade,posing a potential threat to the aquatic environment.However,little is known about the potential adverse effects of SAs on nontarget organisms(e.g.,microalgae)in the aquatic ecosystem.In this study,the effect of SAs(sulfadiazine(SD),sulfamerazine(SM1),and sulfamethazine(SM2)at 1,5,20,and 50 mg/L concentrations,respectively)on the freshwater microalga Dictyosphaerium sp.was investigated,with respect to changes of biomass and chlorophyll a content and induction of extracellular polymer substances(EPS),including protein and polysaccharide contents.At the same time,the residue of SAs was determined.The results showed that Dictyosphaerium sp.was tolerant to the three SAs,and the chlorophyll a content in Dictyosphaerium sp.significantly decreased on day 7,followed by a"compensation phenomena".The increase in protein and polysaccharide contents played a defensive role in Dictyosphaerium sp.against antibiotic stress,and there was a strong positive correlation between polysaccharide contents and antibiotic concentrations.Dictyosphaerium sp.exhibited 35%–45%,30%–42%,and 26%–51%removal of SD,SM1,and SM2,respectively.This study is helpful to understand the changes of EPS in the defense process of microalgae under the action of antibiotics,and provides a new insight for the ecological removal of antibiotic pollution in natural surface water system.

Eu^(3+)/Tb^(3+)-doped whitlockite nanocrystals:Controllable synthesis,cell imaging,and the degradation process in the bone reconstruction

Whitlockite(WH,Ca_(18)Mg_(2)(HPO_(4))_(2)(PO_(4))_(12))is an important inorganic phase in human bones and has positive significance for participating in the bone reconstruction process.In this paper,we report different doping strategies to prepare WH and WH-Ln(Eu/Tb)nanocrystals,and have successfully synthesized WH-Ln(Eu/Tb)nanoparticles(NPs)with bright red or green fluorescence based on ions exchange doping by two-step hydrothermal reaction.WH-5%Ln(Eu/Tb)NPs with the best fluorescence properties were successfully applied to live cell imaging,and WH-5%Eu NPs were implanted into the bone defect site in rabbit femoral condyles to visually observe its degradation process.The related results would help us understand WH nanocrystals and further expand their potential applications in tissue engineering and related fields.