Electrospun meta-aramid/polysulfone-amide nanocomposite membranes for the filtration of industrial PM2.5 particles.

Filtering of industrial PM2.5 is a major challenge for global environmental and animal protection. Filtering of materials with excellent thermal stability and other comprehensive performances is required for the removal of fine particles in high-temperature operating industries such as steel, cement, metallurgy, incineration, etc. In this study, a meta-aramid/polysulfone-amide (PMIA/PSA) composite nanofibrous filtration membrane is prepared via solution electrospinning for the development of high-temperature-resistant filtering products. To maximize the merits of each component, PMIA/PSA composite nanofibrous membranes with different mass blending ratios are prepared to determine the optimal balance. It is found that the PMIA/PSA composite nanofibrous membranes show excellent thermal stability and thermal shrinkage performance. They also maintain superb mechanical retention ratios after 200 h treatment at 200 °C. In addition, they exhibit excellent removal efficiency of polystyrene aerosol (PSL) particles of various sizes. It is found that the removal efficiency of PMIA/PSA (3/7) is 96.7% for 0.1 µm, 98.3% for 0.2 µm and 99.6% for 0.3 µm particles and it possesses optimal filtration resistance (79 Pa), while other composite membranes can reach a removal efficiency of over 99.7%. Our experimental results illustrate that the filtration efficiency for PM2.5 of PMIA/PSA (7/3), (5/5) composite nanofibrous membranes is still kept as high as 99.9% even after being treated at 200 °C for 120 h. It indicates that the prepared composite nanofibrous membranes have potential for applications where high-efficiency filtration is desired, such as bag dust filters for use under high temperatures.

Glucagon-Like Peptide-1 (GLP-1) Treatment Ameliorates Cognitive Impairment by Attenuating Arc Expression in Type 2 Diabetic Rats.

BACKGROUND Glucagon-like peptide-1 (GLP-1) has been reported to exert some beneficial effects on the central nervous system (CNS). However, the effect of GLP-1 on cognitive impairment associated with type 2 diabetes is not well known. This study investigated the effect of GLP-1 on ameliorating memory deficits in type 2 diabetic rats. MATERIAL AND METHODS Type 2 diabetic rats were induced by a high-sugar, high-fat diet, followed by streptozotocin (STZ) injection and then tested in the Morris Water Maze (MWM) 1 week after the induction of diabetes. The mRNA expression of Arc, APP, BACE1, and PS1 were determined by real-time quantitative PCR, and the Arc protein was analyzed by immunoblotting and immunohistochemistry. RESULTS Type 2 diabetic rats exhibited a significant decline in learning and memory in the MWM tests, but GLP-1 treatment was able to protect this decline and significantly improved learning ability and memory. The mRNA expression assays showed that GLP-1 treatment markedly reduced Arc, APP, BACE1, and PS1 expressions, which were elevated in the diabetic rats. Immunoblotting and immunohistochemistry results also confirmed that Arc protein increased in the hippocampus of diabetic rats, but was reduced after GLP-1 treatment. CONCLUSIONS Our findings suggest that GLP-1 treatment improves learning and memory deficits in type 2 diabetic rats, and this effect is likely through the reduction of Arc expression in the hippocampus.

Nanofiber-reinforced self-healing polysaccharide-based hydrogel dressings for pH discoloration monitoring and treatment of infected wounds.

The escalating global health concern arises from chronic wounds induced by bacterial infections, posing a significant threat to individuals. Consequently, an imperative exist for the development of hydrogel dressings to facilitate prompt wound monitoring and efficacious wound management. To this end, pH-sensitive bromothymol blue (BTB) and pH-responsive drug tetracycline hydrochloride (TH) were introduced into the polysaccharide-based hydrogel to realize the integration of wound monitoring and controlled treatment. Polysaccharide-based hydrogels were formed via a Schiff base reaction by cross-linking carboxymethyl chitosan (CMCS) on an oxidized sodium alginate (OSA) skeleton. BTB was used as a pH indicator to monitor wound infection through visual color changes visually. TH could be dynamically released through the pH response of the Schiff base bond to provide effective treatment and long-term antibacterial activity for chronically infected wounds. In addition, introducing polylactic acid nanofibers (PLA) enhanced the mechanical properties of hydrogels. The multifunctional hydrogel has excellent mechanical, self-healing, injectable, antibacterial properties and biocompatibility. Furthermore, the multifaceted hydrogel dressing under consideration exhibits noteworthy capabilities in fostering the healing process of chronically infected wounds. Consequently, the research contributes novel perspectives towards the advancement of intelligent and expeditious bacterial infection monitoring and dynamic treatment platforms.

A ZIF-8-encapsulated interpenetrated hydrogel/nanofiber composite patch for chronic wound treatment.

Designing wound dressings necessitates the crucial considerations of maintaining a moist environment and implementing effective bacterial control. Furthermore, developing a three-dimensional framework emulating the extracellular matrix (ECM) confers advantages in fostering cellular migration and proliferation. Inspired by this, hydrogel/nanofiber composites have been demonstrated as promising materials for wound dressings. The composites also overcome the disadvantages of poor mechanical properties and rapid release of traditional pure hydrogels. In this study, we constructed a calcium alginate hydrogel/polylactic acid nanofiber (CAH/PLANF) composite with an interpenetrated network. Additionally, the synthesis of zeolitic imidazolate framework-8 (ZIF-8) incorporated into the composite system endowed the system with enhanced mechanical properties and photodynamic antibacterial attributes. The obtained composite patch (ZIF-8@CAH/PLANF) exhibited excellent swelling, strong mechanical properties, low cytotoxicity, and durable photodynamic antibacterial effect with an antibacterial efficacy of higher than 99.99%. Finally, bacterial infection and wound healing properties were investigated in vivo, and the ZIF-8@CAH/PLANF patch was proven to have the ability to fight infection and accelerate wound healing.

Effect of Fabric Substrate and Introduction of Silk Fibroin on the Structural Color of Photonic Crystals.

Monodispersed polystyrene (PS) particles were prepared and deposited onto various kinds of textile fabrics using a gravity sedimentation method. The monodispersed PS particles were self-assembled on fabrics to form a photonic crystal, which has an iridescent structural color. The structural color of fabrics was determined by the bandgaps of photonic crystals. Moreover, the effect of the fabric substrate, including the raw materials, base color, and fabric weave, etc., on the structural color of the photonic crystals was studied. Scanning electron microscopy and UV-vis spectrometry were adopted to characterize the structure and optical performance of photonic crystals. The results indicate that the silk fabric with a black base color and satin weave contribute to a bright and pure textile structural color. In order to solve the problem of low color fastness of the structural color on the fabric surface, silk fibroin (SF) was introduced to the PS microsphere solution. Results show that the addition of SF slightly affects the brightness of the structural color, while it has a certain reinforcing effect on the structural color fastness to rubbing and washing.

Progress of Hydrogel Dressings with Wound Monitoring and Treatment Functions.

Hydrogels are widely used in wound dressings due to their moisturizing properties and biocompatibility. However, traditional hydrogel dressings cannot monitor wounds and provide accurate treatment. Recent advancements focus on hydrogel dressings with integrated monitoring and treatment functions, using sensors or intelligent materials to detect changes in the wound microenvironment. These dressings enable responsive treatment to promote wound healing. They can carry out responsive dynamic treatment in time to effectively promote wound healing. However, there is still a lack of comprehensive reviews of hydrogel wound dressings that incorporate both wound micro-environment monitoring and treatment functions. Therefore, this review categorizes hydrogel dressings according to wound types and examines their current status, progress, challenges, and future trends. It discusses various wound types, including infected wounds, burns, and diabetic and pressure ulcers, and explores the wound healing process. The review presents hydrogel dressings that monitor wound conditions and provide tailored treatment, such as pH-sensitive, temperature-sensitive, glucose-sensitive, pressure-sensitive, and nano-composite hydrogel dressings. Challenges include developing dressings that meet the standards of excellent biocompatibility, improving monitoring accuracy and sensitivity, and overcoming obstacles to production and commercialization. Furthermore, it provides the current status, progress, challenges, and future trends in this field, aiming to give a clear view of its past, present, and future.

3D Modelling for Photonic Crystal Structure in Papilio maackii Wing Scales.

As a typical representative of natural structural colors, the wings of butterflies living in different zones present colors due to different chromogenic mechanisms. In this work, Papilio maackii, a common species of butterfly living in China, was studied in order to clarify the photophysics of its wing scales. A FESEM was applied to observe the microstructure of the scales, and we found that they have a periodic photonic crystal structure. X-ray photoelectron spectroscopy was applied to clarify the wings' chemical composition. Additionally, the optical properties of the scales were investigated using a UV-vis-NIR microspectrophotometer. Then, a simplified three-dimensional photonic crystal model was built according to the microstructure of the wing scales, and the plane-wave expansion method was used to calculate the band gap. The correlation between the calculated band gap and the practical reflective spectrum was also established for the wing scales of Papilio maackii.

Maximizing the performance of n-type Mg3Bi2 based materials for room-temperature power generation and thermoelectric cooling.

Although the thermoelectric effect was discovered around 200 years ago, the main application in practice is thermoelectric cooling using the traditional Bi2Te3. The related studies of new and efficient room-temperature thermoelectric materials and modules have, however, not come to fruition yet. In this work, the electronic properties of n-type Mg3.2Bi1.5Sb0.5 material are maximized via delicate microstructural design with the aim of eliminating the thermal grain boundary resistance, eventually leading to a high zT above 1 over a broad temperature range from 323 K to 423 K. Importantly, we further demonstrated a great breakthrough in the non-Bi2Te3 thermoelectric module, coupled with the high-performance p-type α-MgAgSb, for room-temperature power generation and thermoelectric cooling. A high conversion efficiency of ~2.8% at the temperature difference of 95 K and a maximum temperature difference of 56.5 K are experimentally achieved. If the interfacial contact resistance is further reduced, our non-Bi2Te3 module may rival the long-standing champion commercial Bi2Te3 system. Overall, this work represents a substantial step towards the real thermoelectric application using non-Bi2Te3 materials and devices.

Exploring Hydrogen Incorporation into the Nb4AlC3 MAX Phases: Ab Initio Calculations.

The Nb4AlC3 MAX phase can be regarded as a TMC structure with stacking faults, which has great potential as a novel solid hydrogen storage material. Herein, we used ab initio calculations for understanding the hydrogen incorporation into Nb4AlC3 MAX phases, including equilibrium structural characteristics, energy changes, electronic structures, bonding characteristics, and diffusion paths. According to the calculated results, H has thermal stability in the interstice of the Nb-Al layer, and the most probable insertion site is an octahedron (3-site) composed of three Nb atoms and three Al atoms. When C vacancies are introduced, the Nb-C layer has a specific storage capacity for H. In addition, Al vacancies can also be used as possible sites for H incorporation. Moreover, the introduction of vacancies significantly increase the hydrogen storage capacity of the MAX phase. According to the electronic structure and bonding characteristics, the excellent hydrogen storage ability of the Nb4AlC3 structure may be due to the formation of ionic bonds between H and Nb/Al. It is worth noting that the H-Al bond in the 1-site is a covalent bond and an ionic bond key mixture. The linear synchronous transit optimization study shows that only H diffusion in Al vacancies is not feasible. In conclusion, the Nb-Al layer in Nb4AlC3 can provide favorable conditions for the continuous insertion and subsequent extraction of H, while the vacancy structure is more suitable for H storage. Our work provides solid theoretical results for understanding the hydrogen incorporation into Nb4AlC3 MAX phases that can be helpful for the design of advanced hydrogen storage materials.

Electrospun sandwich polysulfonamide/polyacrylonitrile/polysulfonamide composite nanofibrous membranes for lithium-ion batteries.

The demands for novel approaches that ensure stability in lithium-ion batteries are increasing and have led to the development of new materials and fabrication strategies. In this study, sandwich structure-like polysulfonamide (PSA)/polyacrylonitrile (PAN)/polysulfonamide (PSA) composite nanofibrous membranes were prepared via an electrospinning method and used as a separator in lithium-ion batteries. The spinning time of each polymer nanofiber layer of the composite membranes was respectively and precisely controlled to maximize the merits of each component. It was found that the PSA/PAN/PSA composite nanofibrous membranes exhibited superior thermal stability and excellent porosity, liquid electrolyte uptake and ionic conductivity, showing obvious enhancement as compared to those of the commercial microporous polyolefin separator (Celgard 2400), pure PSA and pure PAN membranes. In addition, they were evaluated in the assembled Li/LiFePO4 cells with an electrolyte solution, and good cycling performance and C-rate capacity were obtained; especially for the case of the PP6P membrane, the first discharge capacity of the battery reached 152 mA h g-1, and the discharge capacity retention ratio was 85.94% from 0.2C to 2C; moreover, the battery displayed highest capacity retention ratio after 70 cycles, which was found to be 96.2% of its initial discharge capacity. Therefore, the PSA/PAN/PSA composite nanofibrous membranes can be regarded as a promising candidate for application in lithium-ion batteries.

Penta-aqua-(1H-benzimidazole-5,6-di-carboxyl-ato-κN)copper(II) penta-hydrate.

The title compound, [Cu(C(9)H(4)N(2)O(4))(H(2)O)(5)]·5H(2)O, contains one crystallographically independent Cu(II) atom and one 1H-benzimidazole-5,6-dicarboxyl-ate (bdc) ligand, along with five coordinated and five uncoordinated water mol-ecules. The Cu(II) atom is six-coordinated by one N atom from the bdc ligand and five O atoms from water mol-ecules, giving an octa-hedral coordination geometry. Hydrogen bonds link the mononuclear complex and uncoordinated water mol-ecules into a three-dimensional network.

Extraordinary Thermoelectric Performance Realized in Hierarchically Structured AgSbSe2 with Ultralow Thermal Conductivity.

Thermoelectric conversion from low-grade heat to electricity is regarded as the highly reliable and environmentally friendly technology in energy-harvesting area. However, how to develop efficient thermoelectric materials using a simple fabrication method is still a critical challenge in thermoelectric community. Here, we first fabricate the high thermoelectric performance of Ca-doped AgSbSe2 with a hierarchical microstructure using a facile approach, namely, mechanical alloying (for only 30 min) and a quick hot-pressing method. The hierarchical microstructure, including point defects (atomic scale), dislocations, and nanoprecipitates (nanoscale) as well as grain boundaries (microscale), strongly scatters phonons with comparable sizes without deterioration of carrier mobility. Because of the higher carrier concentration of nanostructured AgSbSe2 than that of coarse-grain AgSbSe2, power factor can also be improved slightly after nanostructuring. Ca doping further optimizes the carrier concentration and creates the point-defect scattering of phonons, leading to the ultralow lattice thermal conductivity ∼0.27 W m-1 K-1 at 673 K and thus largely improving the peak ZT up to 1.2. The high thermoelectric performance in combination with a facile fabrication method highlights AgSbSe2-based materials as robust thermoelectric candidates for energy harvesting.

The structural coloration of textile materials using self-assembled silica nanoparticles.

The work presented investigates how to produce structural colours on textile materials by applying a surface coating of silica nanoparticles (SNPs). Uniform SNPs with particle diameters in a controlled micron size range (207-350 nm) were synthesized using a Stöber-based solvent varying (SV) method which has been reported previously. Photonic crystals (PCs) were formed on the surface of a piece of textile fabric through a process of natural sedimentation self-assembly of the colloidal suspension containing uniform SNPs. Due to the uniformity and a particular diameter range of the prepared SNPs, structural colours were observed from the fabric surface due to the Bragg diffraction of white light with the ordered structure of the silica PCs. By varying the mean particle diameter, a wide range of spectral colours from red to blue were obtained. The comparison of structural colours on fabrics and on glasses suggests that a smooth substrate is critical when producing materials with high colour intensity and spatial uniformity. This work suggested a promising approach to colour textile materials without the need for traditional dyes and/or pigments. Graphical abstract.

Pre-RC Protein MCM7 depletion promotes mitotic exit by Inhibiting CDK1 activity.

MCM7, a subunit of mini-chromosome maintenance proteins (MCM) complex, plays an important role in initiating DNA replication during the G1 phase and extending DNA strands during the S phase. Here, we demonstrated that MCM7 is not only sustained but maintains association with chromatin during M phase. Remarkably, MCM7 siRNA can accelerate mitotic exit. MCM7 depletion leads to CDK1 inactivation and promotes subsequent cohesin/RAD21 cleavage, which eventually leads to sister chromatin segregation. Moreover, MCM7 is co-localized with tubulin in the mitotic cells and MCM7 depletion results in aberrant mitosis. Our results indicate that MCM7 may exert certain functions on spindle formation to prevent cytokinesis during early mitosis by regulating CDK1 activity.

Facile control of silica nanoparticles using a novel solvent varying method for the fabrication of artificial opal photonic crystals.

In this work, the Stöber process was applied to produce uniform silica nanoparticles (SNPs) in the meso-scale size range. The novel aspect of this work was to control the produced silica particle size by only varying the volume of the solvent ethanol used, whilst fixing the other reaction conditions. Using this one-step Stöber-based solvent varying (SV) method, seven batches of SNPs with target diameters ranging from 70 to 400 nm were repeatedly reproduced, and the size distribution in terms of the polydispersity index (PDI) was well maintained (within 0.1). An exponential equation was used to fit the relationship between the particle diameter and ethanol volume. This equation allows the prediction of the amount of ethanol required in order to produce particles of any target diameter within this size range. In addition, it was found that the reaction was completed in approximately 2 h for all batches regardless of the volume of ethanol. Structurally coloured artificial opal photonic crystals (PCs) were fabricated from the prepared SNPs by self-assembly under gravity sedimentation. Figureᅟ .

[Glucagon-like peptide 1 improves learning and memory abilities of rats with type 2 diabetes].

OBJECTIVE: To investigate the effect of glucagon-like peptide 1 (GLP-1) on cognitive dysfunction in diabetic rats. METHODS: Male SD rats were randomly divided into normal control group, diabetes mellitus (DM) group, and GLP-1 treatment group. Rat models of type 2 diabetes were established by high-sugar and high-fat feeding and streptozotocin (STZ) injection, and 25 days after the onset of diabetes, GLP-1 was infused in GLP-1 treatment group at the rate of 30 pmol·kg-1·min-1 via a subcutaneous osmotic pump for 7 days. The learning and cognitive ability of the rats was assessed with Morris water maze test, and the expression of cognition-related genes in the hippocampus tissue was detected with real-time PCR, Western blotting and immunohistochemical staining. RESULTS: Compared with the normal control group, the diabetic rats showed significantly decreased learning and memory abilities (P<0.05) with increased hippocampal expressions of APP, BACE1, Arc, ERK1/2, PKA, and PKC mRNAs (P<0.05) and Arc protein. Compared with diabetic rats, GLP-1-treated rats showed significantly improvements in the learning and memory function (P<0.05) with decreased expressions of APP, BACE1, Arc, ERK1/2, and PKA mRNAs (P<0.05) and Arc protein. CONCLUSION: GLP-1 can improve cognitive dysfunctions in diabetic rats possibly by regulating the PKC, PKA, and ERK1/2 pathways and inhibiting Arc expression in the hippocampus.

[Effect of different techniques in root canal preparation on coronal microleakage of endodontically treated teeth].

OBJECTIVE: To compare the effect of three techniques in root canal preparation on coronal microleakage of endodontically treated teeth. METHODS: Forty-eight human single-rooted teeth were divided into 4 groups randomly and subjected to different techniques on removal of smear layer. Group A, the control group, irrigation with hydrogen peroxide (H2O2) and normal saline (NS); group B, smear cleared with 5.25% sodium hypochlorite (NaClO) and ethylenediamine tetraacetis (EDTA) gel; group C, irrigation with Odontoson-M ultrasonics; group D, smear layer removed with Nd: YAG laser irradiation. Two specimens of every group were split longitudinally into equal segments and canal walls at coronal portion were examined under scanning electron microscope (SEM). Then ten teeth of every group were filled with warm vertical condensation by Obtura II thermoplasticized gutta-perch injection technique and sealed with zinc oxide eugenol (ZOE). The teeth were immersed in 20 g x L(-1) methylene blue for 7 days, then were demineralized, dehydrated and cleared. Linear dye penetration was determined under a steremicroscope. The data were statistically analyzed. RESULTS: In group A, there were smear layer and debris remained and dentinal tubules were covered. In group B and group C, the smear layer of root canals were removed and dentinal tubules were open. In group D, the root canal dentinal tubules were sealed or semi-sealed and the smear layer were melted and ablated. The mean length of coronal microleakage for group A, B, C, D were (2.15 +/- 0.38), (1.75 +/- 0.28), (2.04 +/- 0.40), (1.73 +/- 0.36) mm. The analysis showed that the linear in group A was longer than that in group B and group D clearly (P < 0.05). CONCLUSION: The coronal microleakage following root canal treatment could be reduced by removing smear layer with different techniques in root canal preparation.

[Effect of nerve growth factor on the promotion of sensory recovery of large skin graft in patients].

OBJECTIVE: To analyze the influence of topical application of nerve growth factor (NGF) on nerve ending regeneration of large skin grafts in patients. METHODS: Sixty wounds from 48 adult patients with small or moderate burn area and scar excision were randomly divided into NGF and control groups, with 30 wounds in each group. The wounds in control group were treated with simple saline solution, while those in NGF group, the graft was first wrapped in a piece of gauze holding 100 ml saline solution containing 9000 AU NGF before operation, and then flushed with same amount of NGF saline underneath skin after application of the graft. From 20 post-operative day on, NGF was injected at multiple points every other day for one month. In control group, only normal saline was used. The texture of the graft, pain sensation, temperature and two - point discrimination, BMRC grade were observed for 12 months. Skin specimens were obtained from 6 wounds in control group, 5 wounds in NGF group, and 4 specimens from normal skin for immunohistological examination of protein gene product 9.5 (PGP 9.5), synaptophysin (SYN), and neuron specific enolase (NSE). The nerve endings regeneration and distribution were also observed. RESULTS: Compared with those in control group, each index of feeling recovered earlier and better in NGF group, with better two - point discrimination ratio and BMRC grade. One year after operation, 17 skin grafts in NGF group reached S4 grade, with two - point discrimination ratio of 1.11 +/- 0.14, while only 5 grafts in control group reached S4 grade, with two - point discrimination ratio of 1.56 +/- 0.73. Six months after operation, rich nerve endings, with integral adnexae were observed in microvascular bed of skin - graft region and tissue interspace around fibromas tissue in subcutaneous tissue in NGF group, while nerve endings were found to be scanty and slender in subcutaneous tissue in control group. CONCLUSION: Local application of NGF can promote nerve regeneration and sensory recovery of grafted skin.