Persistent alterations in gray matter in COVID-19 patients experiencing sleep disturbances:a 3-month longitudinal study

Sleep disturbances are among the most prevalent neuropsychiatric symptoms in individuals who have recovered from severe acute respiratory syndrome coronavirus 2 infections.Previous studies have demonstrated abnormal brain structures in patients with sleep disturbances who have recovered from coronavirus disease 2019(COVID-19).However,neuroimaging studies on sleep disturbances caused by COVID-19 are scarce,and existing studies have primarily focused on the long-term effects of the virus,with minimal acute phase data.As a result,little is known about the pathophysiology of sleep disturbances in the acute phase of COVID-19.To address this issue,we designed a longitudinal study to investigate whether alterations in brain structure occur during the acute phase of infection,and verified the results using 3-month follow-up data.A total of 26 COVID-19 patients with sleep disturbances(aged 51.5±13.57 years,8 women and 18 men),27 COVID-19 patients without sleep disturbances(aged 47.33±15.98 years,9 women and 18 men),and 31 age-and gender-matched healthy controls(aged 49.19±17.51 years,9 women and 22 men)were included in this study.Eleven COVID-19 patients with sleep disturbances were included in a longitudinal analysis.We found that COVID-19 patients with sleep disturbances exhibited brain structural changes in almost all brain lobes.The cortical thicknesses of the left pars opercularis and left precuneus were significantly negatively correlated with Pittsburgh Sleep Quality Index scores.Additionally,we observed changes in the volume of the hippocampus and its subfield regions in COVID-19 patients compared with the healthy controls.The 3-month follow-up data revealed indices of altered cerebral structure(cortical thickness,cortical grey matter volume,and cortical surface area)in the frontal-parietal cortex compared with the baseline in COVID-19 patients with sleep disturbances.Our findings indicate that the sleep disturbances patients had altered morphology in the cortical and hippocampal structures during the acute phase of infection and persistent changes in cortical regions at 3 months post-infection.These data improve our understanding of the pathophysiology of sleep disturbances caused by COVID-19.

The Self-assembling and Application of Inorganic Anti-bacterial Material Made of Natural Nanoporous Carrier

The inorganic antimicrobial material was inhibited to the microbes with the added metal ion,Zn.The primary wet product carrying 5%-10% zinc ion was generated under the following conditions：temperature was 95 ℃,solution zinc concentration was 1.2-2.0 mol/L,and the ratio of Zn solution to zeolite weight was 5：1.The final stable product was manufactured after baking in an oven for 1-3 h at the temperature of 500-900 ℃.The baked material was tested for its disinfection effectiveness and coloring effect when mixed with paint coating.Based on the final batch of tests,the zinc content of this anti-microbial product was further optimized.

Synthesis and Self-assembling of Coumarin-based Low-molecular Weight Organogelators

Four coumarin derivatives（4a-4d） with different alkoxy chains were synthesized. It was found that compound 4d showed a better gelation ability than the other compounds, for example, it could self-assemble into organogels in various organic fluids via ultrasound treatment or heating-cooling process, whereas compound 4c could only gel in a few mixed solvents and compounds 4a, 4b could not form organogel. The results from fluorescent and FT-IR spectra indicate that π-π interaction had an effect on the formation of the organogels of compound 4d besides H-bonding and van der Waals interaction, which were the driving forces for the self-assembling of compound 4c in gel state. The gel of compound 4d in toluene could emit strong fluorescence under UV irradiation and the [2＋2] cyclo-addition was suggested by ^1H NMR and fluorescence spectroscopy. This light-sensitive organogel might find application in optical materials.

A novel artificial nerve graft for repairing longdistance sciatic nerve defects:a self-assembling peptide nanofiber scaffold-containing poly (lactic-co-glycolic acid) conduit

In this study, we developed a novel artificial nerve graft termed self-assembling peptide nanofiber scaffold （SAPNS）-containing poly（lactic-co-glycolic acid） （PLGA） conduit （SPC） and used it to bridge a 10-mm-long sciatic nerve defect in the rat. Retrograde tracing, behavioral testing and histomorphometric analyses showed that compared with the empty PLGA conduit implantation group, the SPC implantation group had a larger number of growing and extending axons, a markedly increased diameter of regenerated axons and a greater thickness of the myelin sheath in the conduit. Furthermore, there was an increase in the size of the neuromuscular junction and myofiber diameter in the target muscle. These findings suggest that the novel artificial SPC nerve graft can promote axonal regeneration and remyelination in the transected peripheral nerve and can be used for repairing peripheral nerve injury.

Chondrogenesis of Precartilaginous Stem Cells in KLD-12 Self-assembling Peptide Nanofiber Scaffold Loading TGF-β3 Gene

The effect of culture in KLD-12 self-assembling peptide nanofiber scaffold containing TGF-β3 gene on differentiation of precartilaginous stem cells （PSCs） into chondrocytes was studied. KLD-12 was synthesized by solid-state method. After TGF-β3 plasmid was loaded into KLD-12 self-assembling peptide nanofiber scaffold, DNA release ability was investigated. PSCs and hTGF-β3 gene were loaded into KLD-12 3-D scaffold, and MTT assay was performed to investigate the cell proliferation, and ELASA assay was used to investigate the expression of TGF-β3. Specific cartilage matrix was examined by quantitative real-time PCR, immunohistochemistry and Alcian Blue staining. Compared with control group, DNA synthesis level of PSCs reached the peak within 3 days when PSCs were cultured in self-assembling peptide nanofiber scaffold loading TGF-β3 plasmid, and maintained this high level within 2 weeks. MTT results showed that the proliferation ability of experimental group was statistically higher than that in control group （P〈0.05）. Quantitative real-time PCR suggested that the percentage of TGF-β3 positive PSCs in experimental group was higher than that in control group （P〈0.01）. ELISA assay showed that the TGF-β3 protein level increased in supernatant of experimental group＇s PSCs, reached the peak after 72 h and then declined a little to the plateau phase. Compared with the control group, the specific gene of chondrocyte typical extracellular matrix significantly up-regulated （P〈0.01）. The results showed that PSCs differentiated into chondrocytes in self-assembling peptide nanofiber scaffold loading TGF-β3 plasmid, which provided a fresh approach to cartilage tissue engineering.

Self-assembling peptide nanofibrous hydrogel as a promising strategy in nerve repair after traumatic injury in the nervous system

Following injury in central nervous system（CNS）,there are pathological changes in the injured region,which include neuronal death,axonal damage and demyelination,inflammatory response and activation of glial cells.The proliferation of a large number of astrocytes results in the formation of glial scar.

Self-assembling Behavior of Amphiphilic Copolymer Containing Cross-linked Hydrophilic Block in Ethanol

The self-assembly behavior of the amphiphilic block copolymer poly（ methyl methacrylate） -block-poly（ lead dimethacrylate） （PMMA-b-PLDMA） with cross-linked hydrophilic block（PLDMA） in ethanol was investigated. The results show that the size and morphology of the resulting micelle or micellar aggregates are ascribed to the content of ethanol and the nature of the solvent mixture. PbS nanoparticles were formed in the micelle by in situ reaction with H2S gas. The morphology and size of the self-assembly objects were investigated using scanning electron microscopy （SEM） and transmission electron microscopy（TEM）.

SYNTHESIS OF A NOVEL SELF-ASSEMBLING NLO POLYMERIC FILM

By covalently binding chromophore NPP, N-(4-nitrophenyl)-(L)-prolinol, to a structurally controlled cage-like cross-linking polymer (SCCP), a modified nonlinear optical (NLO) polymeric film prepared by 'in situ poling and sol-gel' process successfully overcame the fundamental problem of NPP chromophores subliming out from the cages of the 'doped'' NLO polymeric film when heated or placed under UV light. Its d(33) (coefficient of second harmonic generation) is 2.0 X 10(-8) esu. measured by IR dichroism. The modified film has a low decay of the SHG signal and preserves 94% of the initial value after 50 days at room temperature These properties match that of the 'doped' film, indicating that the modified film also retains the main advantages of the 'doped' film.

In vivo 3-photon fluorescence microscopy of white matter in mouse brain excited at the 1700 nm window

White matter,a densely packed collection of myelinated axons,plays an essential part in neural networks.With high spatial resolution and deep penetration,multi-photon microscopy(MPM)is promising for white matter imaging in animal models in vivo.The third harmonic generation(THG)signal can be generated from white matter,but the bottom part of the white matter layer generates weak THG due to its high scattering.Here,we demonstrate an in vivo labeling and imaging technology,capable of visualizing the white matter layer in the mouse brain,combining°uorescence labeling with MitoTracker Red and three-photon°uorescence(3PF)microscopy excited at the 1700 nm window.3PF signals are several times higher than THG signals,resulting in deeper imaging of the white matter layer with the former.Our results indicate that 3PF microscopy is a promising technology for white matter imaging in the deep brain in vivo.

Third Generation Horseradish Peroxidase Biosensor Based on Self-assembling Carbon Nanotubes to Gold Electrode Surface

A third-generation horseradish peroxidase (HRP) biosensor has been developed by adsorbing HRP on multi-wall carbon nanotube (MWNTs) monolayer modified gold electrode surface. The assembly process was investigated by electrochemical and spectroscopic techniques. Results showed that the immobilized HRP exhibited direct electrochemical behavior toward the reduction of H2O2. The resulting biosensor shows a fast amperometric response (<2 s) to H2O2. The linear response range was from 5.0×10-7～1.0×10-5 mol/L with a detection limit of 1.0×10-7mol/L. Moreover, the biosensor has a good reproducibility, and long-term stability.

The Self-Assembling Growth of Copper Nanowires for Transparent Electrodes

Long(15-40 μm), thin(diameter of 20 ± 5 nm), and well-dispersed CuNWs Cu nanowires were prepared. The high-resolution TEM and selected area electron diffraction showed that the CuNWs were single-crystalline. To investigate the growth mechanism, we examined the microstructure of these CuNWs at different reaction time. It was found that the CuNWs were actually formed through the self-assembling of Cu nanoparticles along the [110] direction. The transparent electrodes fabricated using the CuNWs achieved a high transparency of 76 % at 31±5 Ω/□.

Ethyl acetate fraction of Sargassum pallidum extract attenuates particulate matter-induced oxidative stress and inflammation in keratinocytes and zebrafish

Objective:To evaluate the effect of the ethyl acetate fraction derived from Sargassum pallidum extract against particulate matter(PM)-induced oxidative stress and inflammation in HaCaT cells and zebrafish.Methods:HaCaT cells and zebrafish were used to evaluate the protective effects of the ethyl acetate fraction of Sargassum pallidum extract against PM-induced oxidative stress and inflammation.The production of nitric oxide(NO),intracellular ROS,prostaglandin E_(2)(PGE_(2)),and pro-inflammatory cytokines,and the expression levels of COX-2,iNOS,and NF-κB were evaluated in PM-induced HaCaT cells.Furthermore,the levels of ROS,NO,and lipid peroxidation were assessed in the PM-exposed zebrafish model.Results:The ethyl acetate fraction of Sargassum pallidum extract significantly decreased the production of NO,intracellular ROS,and PGE_(2) in PM-induced HaCaT cells.In addition,the fraction markedly suppressed the levels of pro-inflammatory cytokines and inhibited the expression levels of COX-2,iNOS,and NF-κB.Furthermore,it displayed remarkable protective effects against PM-induced inflammatory response and oxidative stress,represented by the reduction of NO,ROS,and lipid peroxidation in zebrafish.Conclusions:The ethyl acetate fraction of Sargassum pallidum extract exhibits a protective effect against PM-induced oxidative stress and inflammation both in vitro and in vivo and has the potential as a candidate for the development of pharmaceutical and cosmeceutical products.

Self-assembling Synthesis of Vanadium Oxide Nanotubes and Simple Determination of the Content of V(IV)

High-yielding low-cost vanadium oxide nanotubes were prepared by the hydrothermal self-assembling process from vanadium pentoxide and organic molecules as structure-directing templates.Moreover,a new method was discovered for determining the content of V (IV) in vanadium oxide nanotubes by thermogravimetric analysis (TGA).This method is simple,precise and feasible and can be extended to determine the content of low oxidation state in the other transition metal oxide nanomaterials.

Multiple enrichment mechanisms of organic matter in the Fengcheng Formation of Mahu Sag,Junggar Basin,NW China

Based on core and thin section data,the source rock samples from the Fengcheng Formation in the Mahu Sag of the Junggar Basin were analyzed in terms of zircon SIMS U-Pb geochronology,organic carbon isotopic composition,major and trace element contents,as well as petrology.Two zircon U-Pb ages of(306.0±5.2)Ma and(303.5±3.7)Ma were obtained from the first member of the Fengcheng Formation.Combined with carbon isotopic stratigraphy,it is inferred that the depositional age of the Fengcheng Formation is about 297-306 Ma,spanning the Carboniferous-Permian boundary and corresponding to the interglacial period between C4 and P1 glacial events.Multiple increases in Hg/TOC ratios and altered volcanic ash were found in the shale rocks of the Fengcheng Formation,indicating that multiple phases of volcanic activity occurred during its deposition.An interval with a high B/Ga ratio was found in the middle of the second member of the Fengcheng Formation,associated with the occurrence of evaporite minerals and reedmergnerite,indicating that the high salinity of the water mass was related to hydrothermal activity.Comprehensive analysis suggests that the warm and humid climate during the deposition of Fengcheng Formation is conducive to the growth of organic matter such as algae and bacteria in the lake,and accelerates the continental weathering,driving the input of nutrients.Volcanic activities supply a large amount of nutrients and stimulate primary productivity.The warm climate and high salinity are conducive to water stratification,leading to water anoxia that benefits organic matter preservation.The above factors interact and jointly control the enrichment of organic matter in the Fengcheng Formation of Mahu Sag.

Design of Self-Assembling Molecules and Boundary Value Problem for Flows on a Space of <i>n</i>-Simplices

Self-assembling molecules are ubiquitous in nature, among which are proteins, nucleic acids (DNA and RNA), peptides and lipids. Recognizing the ability of biomolecules to self-assemble into various 3D shapes at the nanoscale, researchers are mimicking the self-assembly strategy for engineering of complex nanostructures. However, the general principles underlying the design of self-assembled molecules have not yet been identified. The question is “How to obtain a well-defined shape with desired properties by folding a chain of subunits (such as amino acids and nucleic acids)”, where properties are determined by the precise spatial arrangement of the subunits on the surface. In this paper, we consider the question from the viewpoint of the discrete differential geometry of n-simplices. Self-assembling molecules are then represented as a union of trajectories of 3-simplices (i.e., tetrahedrons), and the question is rephrased as a “boundary value problem” for flows on a space of tetrahedrons. Also considered is a characterization of two types of surface flows of n-simplices. It is a rough classification of surface flows, but may be essential in characterizing important properties of biomolecules such as allosteric regulation. The author believes this paper not only provides a new perspective for the engineering of self-assembling molecules, but also promotes further collaboration between mathematics and other disciplines in life science.

SELF-ASSEMBLING AMPHIPHILIC POLYELECTROLYTES AND THEIR NANOSTRUCTURES

The self-assembling behavior of random copolymers of sodium 2-(acrylamido)-2-methylpropanesulfonate (AMPS)and hydrophobic comonomers possessing dodecyl groups linked by various spacer bonds was discussed with a focus on theeffect of the spacer. The characterization of association behavior of such polymers in water using quasielastic light scattering,capillary electrophoresis, NMR relaxation, various fluorescence, and viscoelastic methods was described. These copolymersform a variety of self-assembled nanostructures depending on the type of the spacer. Random copolymers of AMPS and N-dodecylmethacrylamide show a strong preference for intrapolymer self-association even in concentrated aqueous solutionsforming single-macromolecular self-assemblies (unimolecular micelles). In contrast, random copolymers of AMPS anddodecyl methacrylate are prone to undergo interpolymer associations yielding multipolymer micelles. In random copolymersof AMPS and a methacrylate substituted a nonionic surfactant (HO(CH_2CH_2O)_(25)C_(12)H_(25)) (C_(12)E_(25)), dodecyl groups are muchless restricted by the polymer backbone because they are linked via a long, flexible hydrophilic spacer. Thus, the polymer-bound C_(12)E_(25) surfactant moieties form micelles similar to those formed by discrete surfactants, but they are bridged bypolymer chains forming a network structure.

A Simple Deposition Method for Self-Assembling Single Crystalline Hybrid Perovskite Nanostructures

A sequential deposition method is developed, where the hybrid organic-inorganic halide perovskite （CH3NH3Pb （I1-xBrx）3 ） is synthesized using precursor solutions containing CH3NH3I and PbBr2 with different mole ratios and reaction times. The perovskite achieved here is quite stable in the atmosphere for a relatively long time without noticeable degradation, and the perovskite nanowires are proved to be single crystalline structure, based on transmission electron microscopy.Furthermore, strong red photoluminescence from perovskite is observed in the wavelength range from 746nm to 770nm with the increase of the reaction time, on account of the exchanges between I- ions and Br- ions in the perovskite crystal. Lastly, the influences of concentration and reaction time of the precursor solutions are discussed, which are important for evolution of hybrid perovskite from nanocuboid to nanowire and nanosheet.

SYNTHESIS OF A NOVEL AMPHIPHILE, 4-[4-(4-DECYLOXYPHENYLAZO) NAPHTHYLOXY] BUTYL TRIMETHYLAMMONIUM BROMIDE, AND ITS SELF-ASSEMBLING BEHAVIOR IN DILUTE AQUEOUS SOLUTION

A novel amphiphile of 4-[4-(4-decyloxyphenylazo) naphthyloxy] butyl trimethylammonium bromide has been synthesized. It can form the stable bilayer in dilute aqueous solution.

Thick Electrodes of a Self-Assembled MXene Hydrogel Composite for High-Rate Energy Storage

Supercapacitors based on two-dimensional MXene(Ti_(3)C_(2)T_(z))have shown extraordinary performance in ultrathin electrodes with low mass loading,but usually there is a significant reduction in high-rate performance as the thickness increases,caused by increasing ion diffusion limitation.Further limitations include restacking of the nanosheets,which makes it challenging to realize the full potential of these electrode materials.Herein,we demonstrate the design of a vertically aligned MXene hydrogel composite,achieved by thermal-assisted self-assembled gelation,for high-rate energy storage.The highly interconnected MXene network in the hydrogel architecture provides very good electron transport properties,and its vertical ion channel structure facilitates rapid ion transport.The resulting hydrogel electrode show excellent performance in both aqueous and organic electrolytes with respect to high capacitance,stability,and high-rate capability for up to 300μm thick electrodes,which represents a significant step toward practical applications.

Self-assembly of perovskite nanocrystals:From driving forces to applications

Self-assembly of metal halide perovskite nanocrystals(NCs)into superlattices can exhibit unique collective properties,which have significant application values in the display,detector,and solar cell field.This review discusses the driving forces behind the self-assembly process of perovskite NCs,and the commonly used self-assembly methods and different self-assembly structures are detailed.Subsequently,we summarize the collective optoelectronic properties and application areas of perovskite superlattice structures.Finally,we conclude with an outlook on the potential issues and future challenges in developing perovskite NCs.