Spin-degree manipulation for one-dimensional room-temperature ferromagnetism in a haldane system.

The intricate correlation between lattice geometry, topological behavior and charge degrees of freedom plays a key role in determining the physical and chemical properties of a quantum-magnetic system. Herein, we investigate the introduction of the unusual oxidation state as an alternative pathway to modulate the magnetic ground state in the well-known S = 1 Haldane system nickelate Y2BaNiO5 (YBNO). YBNO is topologically reduced to incorporate d9-Ni+ (S = 1/2) in the one-dimensional Haldane chain system. The random distribution of Ni+ for the first time results in the emergence of a one-dimensional ferromagnetic phase with a transition temperature far above room temperature. Theoretical calculations reveal that the antiferromagnetic interplay can evolve into ferromagnetic interactions with the presence of oxygen vacancies, which promotes the formation of ferromagnetic order within one-dimensional nickel chains. The unusual electronic instabilities in the nickel-based Haldane system may offer new possibilities towards unconventional physical and chemical properties from quantum interactions.

Voltage activation induced MoO42- dissolution to enhance performance of iron doped nickel molybdate for oxygen evolution reaction.

Transition metal-based precatalysts are typically voltage-activated before electrochemical testing in the condition of alkaline oxygen evolution reaction. Nevertheless, the impact of voltage on the catalyst and the anion dissolution is frequently disregarded. In this study, Fe-doped NiMoO4 (Fe-NiMoO4) was synthesized as a precursor through a straightforward hydrothermal method, and MoFe-modified Ni (oxygen) hydroxide (MoFe-NiOxHy) was obtained via cyclic voltammetry (CV) activation. The effects of voltage on Fe-NiMoO4 and the dissolved inactive MoO42- ions in the process were examined in relation to OER performance. It has demonstrated that the crystallinity of the catalyst is reduced by voltage, thereby enhancing its electrocatalytic activity. The electron distribution state can be adjusted during the application of voltage, leading to the generation of additional active sites and an acceleration in the reaction rate. Additionally, MoO42- exhibits potential dependence during its dissolution. In the OER process, the dissolution of MoO42- enhances the reconstruction degree of Fe-NiMoO4 into the active substance and expedites the formation of active Ni(Fe)OOH. Hence, the optimized MoFe-NiOxHy exhibited exceptional electrocatalytic performance, with a current density of 100 mA cm-2 achieved at an overpotential of only 256 mV. This discovery contributes to a more comprehensive understanding of alkaline OER performance under the influence of applied voltage and the presence of inactive oxygen ions, offering a promising avenue for the development of efficient electrocatalysts.

A Doping-Induced SrCo0.4 Fe0.6 O3 /CoFe2 O4 Nanocomposite for Efficient Oxygen Evolution in Alkaline Media.

Perovskite and spinel oxides are promising alternatives to noble metal-based electrocatalysts for oxygen evolution reaction (OER). Herein, a novel perovskite/spinel nanocomposite comprised of SrCo0.4 Fe0.6 O3 and CoFe2 O4 (SCF/CF) is prepared through a simple one-step method that incorporates iron doping into a SrCoO3- δ matrix, circumventing complex fabrication processes typical of these materials. At a Fe dopant content of 60%, the CoFe2 O4 spinel phase is directly precipitated from the parent SrCo0.4 Fe0.6 O3 perovskite phase and the number of active B-site metals (Co/Fe) in the parent SCF can be maximized. This nanocomposite exhibits a remarkable OER activity in alkaline media with a small overpotentional of 294 mV at 10 mA cm-2 . According to surface states analysis, the parent SCF perovskite remains in its pristine form under alkaline OER conditions, serving as a stable substrate, while the second spinel CF is covered by 5/8 monolayer (ML) O*, exhibiting considerable affinity toward the oxygen species involved in the OER. Analysis based on advanced OER microkinetic volcano model indicates that a 5/8 ML O* covered-CF is the origin for the remarkable activity of this nanocomposite. The results reported here significantly advance knowledge in OER and can boost application, scale-up and commercialisation of electrocatalytic technologies toward clean energy devices.

Oxyanion Engineering Suppressed Iron Segregation in Nickel-Iron Catalysts Toward Stable Water Oxidation.

Nickel-iron catalysts represent an appealing platform for electrocatalytic oxygen evolution reaction (OER) in alkaline media because of their high adjustability in components and activity. However, their long-term stabilities under high current density still remain unsatisfactory due to undesirable Fe segregation. Herein, a nitrate ion (NO3 - ) tailored strategy is developed to mitigate Fe segregation, and thereby improve the OER stability of nickel-iron catalyst. X-ray absorption spectroscopy combined with theoretical calculations indicate that introducing Ni3 (NO3 )2 (OH)4 with stable NO3 - in the lattice is conducive to constructing the stable interface of FeOOH/Ni3 (NO3 )2 (OH)4 via the strong interaction between Fe and incorporated NO3 - . Time of flight secondary ion mass spectrometry and wavelet transformation analysis demonstrate that the NO3 - tailored nickel-iron catalyst greatly alleviates Fe segregation, exhibiting a considerably enhanced long-term stability with a six-fold improvement over FeOOH/Ni(OH)2 without NO3 - modification. This work represents a momentous step toward regulating Fe segregation for stabilizing the catalytic performances of nickel-iron catalysts.

Multiple chemical valences induced interface regulation in perovskite nickelate/carbon nitride for boosting photocatalytic hydrogen evolution.

Recent developments in transition metal-based photocatalysts have heightened the need for superior solar utilization. Evidence suggests that properly adjusting the chemical valence of the transition metal elements could simultaneously achieve broad-spectrum absorption and efficient charge separation for the photocatalysts. However, the understanding and application of this strategy remain a significant challenge. Herein, a series of La0.9Ni0.8Co0.2O3-α/g-C3N4 (LNCO/CN) composites were synthesized employing a mild reduction procedure in the H2/Ar atmosphere. Experimental studies reveal that the composites regulated by interfacial coordination unsaturation Ni2+ and metal Ni0 possess accelerated Z-scheme charge transfer through the interfacial bond between Ni2+ and N. Besides, the localized-surface-plasmon-resonance-induced "hot electrons" injection process of in situ grown Ni0 nanoparticle is confirmed, which can efficiently quench the photoinduced holes and create hole vacancies around the interface. Due to the synergistic effect between Ni2+ and Ni0, the lifetime of the photo-excited electrons is prolonged with inhibited recombination behavior. After modulation, optimal LNCO/CN Z-scheme hybrid exhibits 9-fold promotion of photocatalytic hydrogen evolution rate compared to pristine LNCO/CN. This study gives valuable insight into the purposeful utilization of the chemical valence modulating strategy, which alters the chemical valence of transition metal elements to enhance the performance of perovskite-based photocatalysts dramatically.

Sulfur vacancy and p-n junction synergistically boosting interfacial charge transfer and separation in ZnIn2S4/NiWO4 heterostructure for enhanced photocatalytic hydrogen evolution.

Constructing a p-n heterojunction with vacancy is advantageous for speeding up carrier separation and migration due to the synergy of the built-in electric field and electron capture of the vacancy. Herein, a sulfur vacancy riched-ZnIn2S4/NiWO4 p-n heterojunction (VZIS/NWO) photocatalyst was rationally designed and fabricated for photocatalytic hydrogen evolution. The composition and structure of VZIS/NWO were characterized. The existence of sulfur vacancy was confirmed through X-ray photoelectron spectroscopy, high-resolution transmission electron microscope, and electron paramagnetic resonance technology. The p-n heterojunction formed by ZnIn2S4 and NiWO4 was proved to provide a convenient channel to boost interfacial charge migration and separation. By reducing the band gap, the vacancy engineer can improve light absorption as well as serve as an electron trap to improve photo-induced electron-hole separation. Benefiting from the synergy of p-n heterojunction and vacancy, the optimal VZIS/NWO-5 catalyst exhibits dramatically enhanced H2 generation performance, which is about 10-fold that of the pristine ZnIn2S4. This work emphasizes the synergy between p-n heterojunction and sulfur vacancy for enhancing photocatalytic hydrogen evolution performance.

Axial Ligand as a Critical Factor for High-Performance Pentagonal Bipyramidal Dy(III) Single-Ion Magnets.

The choice of axial ligands is of great importance for the construction of high-performance Dy-based single-molecule magnets (SMMs). Here, combining axial ligands Ph3SiO- (anion of triphenylsilanol) and 2,6-dichloro-4-nitro-PhO- (the anion of 2,6-dichloro-4-nitrophenol) with a neutral macrocyclic ligand 2,14-dimethyl-3,6,10,13,19-pentaazabicyclo[13.3.1]nonadeca-1(19),2,13,15,17-pentaene (L2N5) generates two new pentagonal bipyramidal Dy(III) complexes [DyIII(L2N5) (X)2](BPh4) (X = Ph3SiO-, 1; 2,6-dichloro-4-nitro-PhO-, 2) with strong axial ligand fields. Magnetic characterizations show that 1 possesses a large energy barrier above 1000 K and a magnetic hysteresis up to 9 K, whereas 2 only displays field-induced peaks of alternating-current susceptibilities without the hysteresis loop, even though 2 has a similar coordination geometry with 1. Detailed Ab initio calculations indicate an apparent difference in the axial negative charge between both complexes, which is caused by the diverse electron-donating properties of the axial ligands. The present work provides an efficient strategy to enhance the SMMs' properties, which highlights that the electron-donating property of the axial ligands is especially important for constructing the high-performance Dy-based SMMs.

Structural-Functional Pluralistic Modification of Silk Fibroin via MOF Bridging for Advanced Wound Care.

Silk fibroin (SF) is widely used to fabricate biomaterials for skin related wound caring or monitoring, and its hydrogel state are preferred for their adaptability and easy to use. However, in-depth development of SF hydrogel is restricted by their limited mechanical strength, increased risk of infection, and inability to accelerate tissue healing. Therefore, a structure-function pluralistic modification strategy using composite system of metal organic framework (MOF) as bridge expanding SF's biomedical application is proposed. After developing the photocuring and bonding SF hydrogel, a MOF drug-loading system is utilized to enhance hydrogel's structural strength while endowing its antibacterial and angiogenic properties, yielding a multifunctional SF hydrogel. The synergy between the MOF and SF proteins at the secondary structure level gives this hydrogel reliable mechanical strength, making it suitable for conventional wound treatment, whether for closing incisions quickly or acting as adhesive dressings (five times the bonding strength of ordinary fibrin glue). Additionally, with the antibacterial and angiogenic functions getting from MOF system, this modified SF hydrogel can even treat ischemic trauma with cartilage exposure. This multiple modification should contribute to the improvement of advanced wound care, by promoting SF application in the production of tissue engineering materials.

Boosting hydrogen and oxygen evolution of porous CoP nanosheet arrays through electronic modulating with oxygen-anion-incorporation.

The exploration of earth-abundant single catalyst with high-efficiency bifunctional catalytic active sites for accelerated hydrogen and oxygen evolution reactions (HER and OER) is highly desirable but challenging. Herein, the synthesis of self-supported directional flake oxygen-incorporated cobalt phosphide arrays (O-CoP) with efficient bifunctional catalytic active sites was achieved by in situ oxidation followed by phosphorization of cobalt metal-organic framework nanosheet arrays (Co-MOF). By controlling the phosphating time, the P/O atomic ratio in the oxygen-incorporated cobalt phosphide could be adjusted, leading to the change of Co3+/Co2+ couples, and thus affecting the electronic environment of the cobalt active site. Benefiting from the tunable electronic structure and unique array architecture, the synthesized catalysts exhibited excellent electrocatalytic water decomposition for both HER and OER. Moreover, in the HER and OER couple system (HER||OER), the optimal O-CoP-40 catalyst delivers a low overpotential of only 1.54 V to obtain the 10 mA cm-2 and stably-running for 36 h. Theoretical calculations demonstrated that the electron-rich P-3p and O-2p orbitals could co-modulate the electronic environment of Co sites, which boosted water dissociation in the HER process and balanced the adsorption/desorption of intermediates in the OER pathway, resulting in a good overall water splitting. This research provides an effective strategy for the construction of efficient bifunctional phosphide electrocatalysts, as well as contributes to the understanding of anion incorporating to regulate the electronic structure of phosphides.

Ultrafast interfacial charge evolution of the Type-II cadmium Sulfide/Molybdenum disulfide heterostructure for photocatalytic hydrogen production.

The interfacial charge dynamics was crucial for semiconductor heterostructure photocatalysis. Through the rational design of the heterostructure interface, heterojunction expressed variable recombination and migration dynamics for excited carriers. Herein, followed by a typical chemical bath strategy with the hexagonal cadmium sulfide (CdS) overlapped on the exfoliated molybdenum disulfide (MoS2) film, we developed a cadmium sulfide/molybdenum disulfide (CdS-MoS2) nano-heterojunction and investigated the interfacial charge dynamics for photocatalytic hydrogen evolution. Photoelectron spectroscopy detected an energetic offset between CdS and MoS2, revealing the formation of an interfacial electric field with efficient charges separation. Through transient absorption spectra, we demonstrated the type-II contact at the CdS-MoS2 interface. Driven by the electric field, the excited carriers separated and rapidly migrated to sub-band defects of CdS within the first 500 fs. The carriers-restricted defects provided catalytic active sites, endowing CdS-MoS2 a highly efficient photocatalytic capability. Consequentially, the CdS-MoS2 achieved an enhanced hydrogen evolution rate of 2.3 mmol·g-1·h-1 with significantly stronger photocurrent density. This work gave an insight to the channel of interfacial separation and migration for excited carriers, which could contribute to the interfacial engineering of advanced heterojunction photocatalysts.

Highly clean and efficient iron phosphates modified by Ru nanocrystals for water oxidation.

Optimizing the architecture of non-polluting, highly efficient, robust, and cost-effective electrocatalysts for the oxygen evolution reaction (OER) is extremely crucial for accelerating the application of water splitting. Herein, a highly green and active OER electrocatalyst composed of Ru nanocrystal modified iron-rich phosphates is successfully developed via a hydrothermal and post-annealing approach. The eco-friendly phosphorus source of lecithin is employed to fabricate transition metal phosphates for the first time, which avoids the use of toxic and dangerous phosphorus sources. Meanwhile, it is found that Ru nanocrystals could form heterostructures with iron phosphates and induce conversion to iron-rich phosphates, which would greatly enhance the conductivity of the substrate and elevate the catalytic activity. As a result, overpotentials of only 250 mV and 290 mV are required to deliver 10 and 100 mA cm-2 using this typical electrocatalyst. Also, the j-t curve shows no distinct variations in current over 45 h at a constant overpotential of 334 mV, indicating the outstanding activity and durability of the catalyst. Furthermore, nickel/cobalt-rich phosphates and phosphides were also acquired using similar experimental procedures, manifesting the wide applicability of Ru actuation. Hence, this work offers a convenient and scalable method for designing highly efficient, green, clean, and cost-effective electrocatalysts for water splitting.

Controlled preparation of hollow Zn0.3Cd0.7S nanospheres modified by NiS1.97 nanosheets for superior photocatalytic hydrogen production.

Developing durable and efficient photocatalysts for H2 evolution is highly desirable to expedite current research on solar-chemical energy conversion. In this work, a novel photocatalytic H2 evolution system based on Zn0.3Cd0.7S/NiS1.97 nanocomposite was rationally designed for the first time. In this advanced composite structure, NiS1.97 nanosheets as a co-catalyst were intimately coupled to the inner surface of the hollow spherical Zn0.3Cd0.7S. The construction of the hollow spherical shell shortened the distance of charge migration to the surface site and increased the multiple absorption of incident light. The introduction of NiS1.97 nanosheets increased the light absorption capacity of the composite system and also greatly improved the separation and migration behavior of photo-generated carriers due to its narrower band gap and relatively low conduction band position, which had been confirmed by DRS, EIS and PL. As a result, the hollow Zn0.3Cd0.7S/NiS1.97 composite material exhibited excellent photocatalytic activity. At the loading amount of NiS1.97 up to 15 at.%, the hollow Zn0.3Cd0.7S/NiS1.97 composite exhibited the best photocatalytic activity with a corresponding H2 production rate of 22.637 mmol g-1h-1, which was 1.42 times and 1.85 times that of hollow Zn0.3Cd0.7S and solid Zn0.3Cd0.7S, respectively. Moreover, this novel catalyst also displayed a long-term stability without apparent debasement in H2 evolution activity. It is expected that this work could provide new inspiration to the design and development of other highly active photocatalytic systems for water splitting.

Microbial synthesis of efficient palladium electrocatalyst with high loadings for oxygen reduction reaction in acidic medium.

Whereas limited amount of precious metal adsorbed by bacteria conflicting the needs of high loadings for better catalytic performances, cell disruption technology was adopted to smash Shewanella cells in this work, releasing abundant oxygen functional groups inside the cells for better adsorption of palladium ion. Then palladium catalysts were synthesized in two ways: 1) Pd catalyst supported on carbonized-broken-bacterial (Pd/FHNC) was obtained after direct carbonization and reduction; 2) Electrospinning technology was used to spin the broken Shewanella into fibers, and Pd nanoparticles supported on nitrogen-doped carbon nanofiber (Pd/NCNF) was prepared following carbonization and hydrogen reduction. The as-prepared catalysts exhibit excellent oxygen reduction reaction (ORR) electrocatalytic performance in the acid medium. The mass specific activities at 0.7 V of Pd/FHNC and Pd/NCNF were 0.213 A mg-1 and 0.121 A mg-1 which were 5.92 and 3.36 times than those of commercial Pd/C(0.036 A mg-1) respectively, and they also displayed higher stability than Pd/C. Furthermore, the Pd loadings of Pd/FHNC and Pd/NCNF were 21.52% and 17.13% respectively. An explanation for the improved performance is the co-doping of nitrogen and phosphorus, also the tight integration of Pd and broken-bacterial. Herein, we propose a novel and effective method for synthesis of ORR electrocatalysts.

Investigating the active sites in molybdenum anchored nitrogen-doped carbon for alkaline oxygen evolution reaction.

Developing durable and efficient non-precious-metal based catalysts for oxygen evolution reaction (OER) is highly desirable in the field of electrocatalysis. In this work, a series of novel Mo anchored N-doped carbon catalysts (denoted as Mo/NC-T) were prepared starting from the zeolitic imidazolate framework 8 (ZIF-8) precursor. Firstly, Mo doped ZIF-8 precursor (Mo/ZIF-8) with a regular polyhedron structure was formed through a simple ion-exchange method process between molybdenum pentachloride (MoCl5) and ZIF-8. Afterward, Mo/ZIF-8 was converted to Mo/NC-T through a two-step calcination process in nitrogen (N2) and ammonia (NH3). The as-synthesized Mo/NC-T samples exhibited superior electrocatalytic OER properties. The optimal sample at 650 °C (Mo/NC-650) presented a low overpotential of 320 mV at 10 mA cm-2, a Tafel slope of 71 mV dec-1, and an outstanding long-term stability for 30 h in 1 M KOH solution. The remarkable OER activity of Mo/NC-T could be ascribed to the structural stability of carbon matrix and the synergistic effect between Mo3+ (derived from Mo-C bonds) and pyridinic N. This work provides a novel perspective on the roles of Mo species in the N-doped carbon electrocatalysts for OER.

Preparation and Performance Evaluation of Antibacterial Melt-Spun Polyurethane Fiber Loaded with Berberine Hydrochloride.

(1) Background: Bacterial infections have long threatened global public safety; hence, it is significant to continuously develop antibacterial fibers that are closely related to people's daily lives. Berberine hydrochloride is a natural antibacterial agent that has application prospects in the preparation of antibacterial fibers. (2) Methods: This study firstly verified the antibacterial properties of berberine hydrochloride and its possible antibacterial mechanism. Thereafter, berberine hydrochloride was introduced into the self-made melt-spun polyurethane fiber through optimized coating technology. The performance of coating modified polyurethane fiber has been systematically evaluated, including its antibacterial properties, mechanical properties, and surface wettability. (3) Results: Results show that the antibacterial polyurethane fiber with desirable comprehensive properties is expected to be used in the biomedical fields. (4) Conclusions: The research also provides a reference for the development and application of other natural antibacterial ingredients in fiber fields.

Polymeric antibacterial materials: design, platforms and applications.

Over the past decades, the morbidity and mortality caused by pathogen invasion remain stubbornly high even though medical care has increasingly improved worldwide. Besides, impacted by the ever-growing multidrug-resistant bacterial strains, the crisis owing to the abuse and misuse of antibiotics has been further exacerbated. Among the wide range of antibacterial strategies, polymeric antibacterial materials with diversified synthetic strategies exhibit unique advantages (e.g., their flexible structural design, processability and recyclability, tuneable platform construction, and safety) for extensive antibacterial fields as compared to low molecular weight organic or inorganic antibacterial materials. In this review, polymeric antibacterial materials are summarized in terms of four structure styles and the most representative material platforms to achieve specific antibacterial applications. The superiority and defects exhibited by various polymeric antibacterial materials are elucidated, and the design of various platforms to elevate their efficacy is also described. Moreover, the application scope of polymeric antibacterial materials is summarized with regard to tissue engineering, personal protection, and environmental security. In the last section, the subsequent challenges and direction of polymeric antibacterial materials are discussed. It is highly expected that this critical review will present an insight into the prospective development of antibacterial functional materials.

Insight into the amorphous nickel-iron (oxy)hydroxide catalyst for efficient oxygen evolution reaction.

The specific roles of Ni and Fe in nickel-iron (oxy)hydroxide catalyst (NiFeOx(OH)y) are extensively discussed during oxygen evolution reaction (OER). However, there still remains controversy about whether Ni or Fe species as the dominate active site. In this work, we reported the NiFeOx(OH)y catalysts with varied atomic ratio of nickel and iron for OER to explore the dominate active site during OER processes. From the electrochemical performances, the similar Tafel slopes of catalysts with Fe species can achieve at a level of 40 mV dec-1, outperforming the Tafel slopes of catalysts without Fe species. Thus, it can be concluded that the present Fe site can serve as the dominant active site in NiFeOx(OH)y for OER. Meanwhile, the Ni species is proved as the OH- adsorption site, which is beneficial to the Fe site to deliver a better OER performance. As a result, the catalyst with an optimal Ni/Fe interface (atomic ratio of 1 : 1.18) displays outstanding OER performances. It only requires a low overpotential of 250 mV to deliver current density of 10 mA cm-2 and exhibits a small Tafel slope of 39 mV dec-1. This catalyst also shows remarkable stability with negligible potential decay after 50 h at a current density of 50 mA cm-2. This work offers a new sight into the specific roles of Ni and Fe in NiFeOx(OH)y for OER.

Catalytic Cleavage of the C-O Bond in 2,6-dimethoxyphenol Without External Hydrogen or Organic Solvent Using Catalytic Vanadium Metal.

Hydrogenolysis of the C-O bonds in lignin, which promises to be able to generate fuels and chemical feedstocks from biomass, is a particularly challenging and important area of investigation. Herein, we demonstrate a vanadium-catalyzed cleavage of a lignin model compound (2,6-dimethoxyphenol). The impact of the catalyst in the context of the temperature, reaction time, and the solvent, was examined for the cleavage of the methyl ethers in 2,6-dimethoxyphenol. In contrast to traditional catalytic transfer hydrogenolysis, which requires high pressure hydrogen gas or reductive organic molecules, such as an alcohol and formic acid, the vanadium catalyst demonstrates superior catalytic activity on the cleavage of the C-O bonds using water as a solvent. For example, the conversion of 2,6-dimethoxyphenol is 89.5% at 280°C after 48 h using distilled water. Notably, the vanadium-catalyzed cleavage of the C-O bond linkage in 2,6-dimethoxyphenol affords 3-methoxycatechol, which undergoes further cleavage to afford pyrogallol. This work is expected to provide an alternative method for the hydrogenolysis of lignin and related compounds into valuable chemicals in the absence of external hydrogen and organic solvents.

Study on the release behaviors of berberine hydrochloride based on sandwich nanostructure and shape memory effect.

Nanofibrous drug delivery systems (DDSs) recently have attracted remarkable interest, especially their potential to program dosage of the encased drug intelligently. Despite this, the exploration of efficient strategy to precisely program drug release from nanofibrous DDS still remains a significant challenge. In this study, we electrospun a near-body temperature (Ttrans ≈ 42 °C) sensitive shape memory polyurethane in three stages through sequential electrospinning technology, and prepared a sort of sandwich structural membrane, comprising of top, inner and bottom layers, wherein a natural antibacterial agent, berberine hydrochloride (BCH), was imbedded inside the middle layer. As demonstrated by the results obtained from tensile testing and morphology characterization, the prepared sandwich structural membrane and the nanofibrous membrane with homogenous structure exhibited not only desirable mechanical properties but also surface morphologies. In addition, the release period can be significantly prolonged in virtue of the sandwich structure. As revealed by the experiment of in vitro drug release, it took nearly 144 h to release 80 wt% BCH from sandwich structural membrane, while as little as 72 h was observed to release the same amount of BCH from that with homogenous structure. More interestingly, the encapsulated BCH is capable to be released in a controlled manner owning to the thermo-sensitive shape memory effect, and the release rate of BCH can be accelerated by stretching and fixing the nanofibrous membranes into certain ratios prior to release. Collectively, this study provides a facile strategy to design and prepare a reliable and smart DDS, i.e. sandwich structural membrane, which may enhance the availability of BCH and also intelligently avoid the bacterial infection.

A novel approach for detection of brucella using a real-time recombinase polymerase amplification assay.

Brucella, the etiological agent of brucellosis, is an important zoonosis pathogen worldwide. Brucella infects humans and various domestic and wild animals, and represents a great threat to public health and animal husbandry. In the present study, we developed a real-time recombinase polymerase amplification (RPA) assay for the detection of Brucella. The assay targeted the bcsp31 gene of Brucella, and an RPA exo probe and a pair of primers were selected for assay validation. RPA sensitivity and specificity were evaluated using plasmid standards, Brucella representative strains, and non-Brucella strains. The RPA assay achieved a detection limit of 17 molecules in 95% of cases based on probit analysis, and could successfully distinguish 18 representative Brucella strains (B. abortus biovars 1, 2, 3, 4, 5, 6, 7 and 9, B. melitensis biovars 1, 2 and 3, B. suis biovars 1, 2, 3 and 4, B. canis, B. neotomae and B. ovis), and four Brucella vaccine strains (A19, S19, S2 and M5). A total of 52 Brucella field strains were detected by real-time PCR and RPA in parallel, and compared with real-time PCR, the sensitivity of the RPA assay was 94% (49/52). Thus, this RPA assay may be a rapid, sensitive, and specific tool for the prevention and control of Brucellosis.