Flexible Aluminum-Air Battery Based on High-Performance Three-Dimensional Dual-Network PVA/KC/KOH Composite Gel Polymer Electrolyte.

With a large theoretical capacity and high energy density, aluminum-air batteries are a promising energy storage device. However, the rigid structure and liquid electrolyte of a traditional aluminum-air battery limit its application potential in the field of flexible electronics, and the irreversible corrosion of its anode greatly reduces the battery life. To solve the above problems, a PVA/KC/KOH (2 M) composite gel polymer electrolyte (GPE) with a three-dimensional dual-network structure consisting of polyvinyl alcohol (PVA), kappa-carrageenan (KC), and potassium hydroxide was prepared in this paper by a simple two-step method and applied in aluminum-air batteries. At room temperature, the ionic conductivity of the PVA/KC/KOH (2 M) composite GPE was found to be up to 6.50 × 10-3 S cm-1. By utilizing this composite GPE, a single flexible aluminum-air battery was assembled and achieved a maximum discharge voltage of 1.2 V at 5 mA cm-2, with discharge time exceeding 3 h. Moreover, the single flexible aluminum-air battery maintains good electrochemical performance under various deformation modes, and the output voltage of the battery remains at about 99% after 300 cycles. The construction of flexible aluminum-air batteries based on a three-dimensional dual-network PVA/KC/KOH composite GPE provides excellent safety and high-multiplication capabilities for aluminum-air batteries, making them potential candidates for various flexible device applications.

Association between overall dietary quality and constipation in American adults: a cross-sectional study.

BACKGROUND: Constipation seriously affects people's life quality, and dietary adjustment has been one of the effective methods. Overall dietary quality has been reported to be associated with some diseases, while its association with constipation has not been reported. This study aims to explore the association between overall dietary quality and constipation. METHODS: A cross-sectional study was designed and data were extracted from National Health and Nutrition Examination Survey (NHANES). Overall dietary quality was assessed by healthy eating index-2015 (HEI-2015), and constipation was defined by either stool consistency or stool frequency. The association between overall dietary quality or components of HEI-2015 and constipation was assessed using logistic regression, with results expressed as odds ratio (OR) and 95% confidence intervals (95%CI). Subgroup analysis was conducted according to age and gender. RESULTS: A total of 13,945 participants were eligible, with 1,407 in constipation group and 12,538 in non-constipation group. Results showed that higher adherence to HEI-2015 was associated with reduced odds of constipation (OR: 0.98, 95%CI: 0.98-0.99) after adjusting potential confounders. Further, we found higher intake of total fruits, whole fruits, total vegetables, greens and beans, whole grains, total protein foods, seafood and plant proteins, and higher fatty acids ratio decreased the odds of constipation, while higher intake of sodium increased the odds (all P < 0.05). We also found negative association between HEI-2015 and constipation in participants with male sex, female sex, age ≥ 65 years, and age < 65 years (all P < 0.05). CONCLUSION: We found higher adherence to HEI-2015 decreased the odds of constipation, suggesting that increasing HEI-2015 adherence may be one of effective methods to alleviate constipation.

Open-tubular capillary electrochromatographic determination of ten sulfonamides in tap water and milk by a metal-organic framework-coated capillary column.

In this study, a metal-organic framework (MOF), [Mn(cam)(bpy)], was synthesized and characterized by thermogravimetric analysis, scanning electron microscopy, and Fourier transform infrared spectrometry. An open-tubular capillary column was fabricated from [Mn(cam)(bpy)] via the amide coupling method. Ten types of sulfonamides were separated through the fabricated capillary column, which showed a good limits of detection (<0.07 µg/mL) and linear ranges (1-100 or 5-100 µg/mL) with a high correlation coefficients (R2 > 0.9987). The intra-day, inter-day and column-to-column relative standard deviations (RSDs) in the migration times ranged from 0.44 to 4.87%, and the peak area RSDs ranged from 0.80 to 7.28%. The developed capillary electrochromatography method can be successfully utilized for the determination of sulfonamides in tap water and milk samples.

Co-location of the blaKPC-2, blaCTX-M-65, rmtB and virulence relevant factors in an IncFII plasmid from a hypermucoviscous Klebsiella pneumoniae isolate.

Hypervirulent variants of klebsiella pneumoniae (hvKP), which cause serious infections not only healthy individuals, but also the immunocompromised patients, have been increasingly reported recently. One conjugation of a hypermucoviscous strian SWU01 co-carried the resistance gene blaKPC-2 and virulence gene iroN by the PCR detection from three carbapenem-resistance hvKP. To know the genetic context of this plasmid. The whole genome of this strain was sequenced. We got a 162,552-bp plasmid (pSWU01) which co-carried the resistance gene blaKPC-2 and virulence gene iroN. It is composed of a typical IncFII-type backbone, five resistance genes including blaCTX-M-65, blaKPC-2, blaSHV-12, blaTEM-1 and rmtB, and several virulence relevant factors including iroN, traT and toxin-antitoxin systems. The plasmid pSWU01 co-carrying the multidrug resistance determinants and virulence relevant factors from the hypermucoviscous K. pneumoniae represents a novel therapeutic challenge.

A sensitive surface-enhanced Raman scattering method for chondroitin sulfate with Victoria blue 4R molecular probes in nanogold sol substrate.

Using silver nanoparticles (AgNPs) as the nanocatalyst, l-cysteine rapidly reduced HAuCl4 to make a stable gold nanoparticle sol (Ag/AuNP) that had a high surface-enhanced Raman scattering (SERS) activity in the presence of Victoria blue 4R (VB4r) molecular probes. Under the selected conditions, chondroitin sulfate (Chs) reacted with the VB4r probes to form associated complexes that caused the SERS effect to decrease to 1618 cm-1 . The decreased SERS intensity was linear to the Chs concentration in the range 3.1-500 ng/ml, with a detection limit of 1.0 ng/ml Chs. Accordingly, we established a simple and sensitive SERS quantitative analysis method to determine Chs in real samples, with a relative standard deviation of 1.47-3.16% and a recovery rate of 97.6-104.2%.

Aptamer based determination of Pb(II) by SERS and by exploiting the reduction of HAuCl4 by H2O2 as catalyzed by graphene oxide nanoribbons.

The authors report that graphene oxide nanoribbons exert a strong catalytic effect on the reduction of HAuCl4 by H2O2 to form gold nanoparticles which display nanoplasmonic surface enhanced Raman scattering (SERS) activity, Rayleigh scattering and absorption. If an aptamer against Pb(II) is present in solution, it will bind to the graphene oxide nanoribbons and thereby inhibit their catalytic activity. Upon addition of Pb(II), it will bind to the aptamer to form stable complexes and release free graphene oxide nanoribbon. These cause the surface enhanced Raman scattering intensity at 1615 cm-1 to increase in the presence of the molecular probe Victoria Blue B. The SERS signal increases linearly in the 0.002-0.075 µmol·L-1 Pb(II) concentration range, and the detection limit is 0.7 nmol·L-1. Toner samples were spiked and then analyzed for Pb(II) by this method. Relative standard deviations are between 6.2% and 12.2%, and recoveries range from of 86.7%-106.7%. Graphic abstract Based on Pb(II) binds to the aptamer to form stable G-quadruplex and release free graphene oxide nanoribbon, a sensitive and selective surface enhanced Raman scattering method was developed for detection of 0.002-0.075 µmol·L-1 Pb(II) by using the molecular probe Victoria Blue B.

[A Hydride Generation-Catalytic Resonance Rayleigh Scattering Method for Detection of Trace Arsenic].

Arsenic is a toxic metal element and the establishment of a highly sensitive and selective method for As has great significance to human health and environment protection. In sulfuric acid medium, As(Ⅲ) was reduced by NaBH4 to form AsH3 gas that was trapped by the Ce(Ⅳ)-I- catalytic absorption solution to cause Ce(Ⅳ) concentration decreased and As particle increased, which resulted in the resonance Rayleigh scattering (RRS) and fluorescence increased at 370 and 351 nm respectively. The increased RRS and fluorescence intensities were linear to As(Ⅲ) concentration in the range of 0.006~0.76 and 0.006~0.28 mg·L(-1) respectively, with a detection of As of 3.0 µg·L(-1). The new hydride generation-catalytic RRS method was applied for detection of trace As(Ⅲ) in milk samples, and the results were in agreement with that of hydride generation-atomic absorption spectrometry.

A nanogold resonance Rayleigh scattering method for determination of trace As based on the hydride nanoreaction.

In H2 SO4 solution, As(III) was reduced to arsine (AsH3 ) by NaBH4 , and was absorbed in HAuCl4 solution to form nanogold particles (NGs) that exhibited a resonance Rayleigh scattering (RRS) effect at 370 nm. Under the selected conditions, when the As(III) concentration increased the RRS peak also increased due to the formation of more NGs. There was a linear correlation between RRS intensity and As(III) concentration in the range 6-1000 ng/mL, with a detection limit of 3 ng/mL. This new hydride generation-nanogold reaction RRS (HG-NG RRS) method was applied to determine trace amounts of As in milk samples, with satisfactory results.

A simple and sensitive fluorescence method for the determination of trace ozone in air using acridine red as a probe.

The ozone in an air sample was trapped by H3 BO3 -LK solution to produce iodine (I2) that interacted with excess I(-) to form I3(-). In pH 4.0 acetate buffer solutions, the I3(-) reacted with acridine red to form acridine red-I3 ion association particles that resulted in the fluorescence peak decreased at 553 nm. The decreased value ΔF553 nm is linear to the O3 concentration in the range 0.08-53.3 × 10(-6) mol/L, with a detection limit of 4 × 10(-8) mol/L. This fluorescence method was used to determine ozone in air samples, and the results were in agreement with that of indigo carmine spectrophotometry.

A new and highly sensitive resonance Rayleigh scattering assay for lysozyme using aptamer-nanogold as a probe.

Gold nanoparticles (GN), 10 nm in size, were modified by using lysozyme aptamer (Apt) to obtain a stable Apt­GN probe in pH 8.05 Tris/HCl buffer solutions containing 0.04 mol/L NaCl. Upon addition of lysozyme (LYS), it reacted with the Apt of the probe to form a very stable Apt­LYS complex and to release GNs, which aggregated to form large clusters with a resonance Rayleigh scattering (RRS) peak at 368 nm. The enhanced peak intensity, ΔI, was linear to the LYS concentration in the range 0.2­5.2 nmol/L, with a detection limit of 0.05 nmol/L. The influence of foreign substance was tested, and the results showed that this RRS method has high selectivity. This Apt­GN RRS method was applied to the analysis of LYS in a real sample, with satisfactory results.

[Resonance Rayleigh scattering determination of trace tobramycin using aptamer-modified nanogold as probe ].

Nanogold (NG) was prepared using NaBH4 reduction of HAuCl4. The NG was modified by the tobramycin-aptamer to obtain a stable Apt-NG probe for tobramycin. The three aptamers containing 15, 21 and 27 bases were examined, and results showed that the aptamer with 21 bases was best and was chosen for use. In pH 6. 8 PBS buffer solution and in the presence of NaCl, the Apt-GN probes were not aggregated. When tobramycin was added, it reacted with the Apt of Apt-NG probe to form a very stable Apt-Tbc complex and released NGs that were aggregated into big particles under the action of NaCl with three resonance Rayleigh scattering peaks at 285, 368 and 525 nm respectively. The resonance Rayleigh scattering peak increased at 368 nm due to the formation of big NG particles from the probe. The effect of pH buffer solution, its volume, and Apt-GN probe concentration on the ΔI value was considered. A 200 µL pH 6. 8 PBS buffer solution and 19. 1 nmol · L(-3) Apt-GN, giving max ΔI value, were chosen for use. Under the chosen conditions, the increased resonance Rayleigh scattering intensity ΔI368 nm was linear with Tbc concentration in the range of 1.9-58.3 ng mL(-3), with a regress equation of ΔI = 35.3c-23 and a detection limit of 0.8 ng · mL(-3) Tbc. A 10.0, 20.0 and 30.0 ng mL-3 Tbc was determined five times respectively, and the relative standard deviations were 6.8%, 5.0% and 4.4%. The influence of some foreign substances was examined on the determination of 38.9 ng · mL(-3) Tbc, within ±10% related error. Results showed that a 80 times of Zn2+, 40 times of L-glutamic acid, Cu2+, Mg2+ and Ca2+, 20 times of glucose and terramycin, 10 times of L-phenylalanine and glycin, 2 times of L-aspartic acid, and 6 times of bovine serum albumin (BSA) and human serum albumin (HSA) do not interfere with the RRS determination of Tbc. The results showed that this aptamer-nanogold RRS method is of good selectivity. Tbc in real sample was analyzed, and the analytical result was in agreement with that of reference results, with a relative standard deviation of 6.5%-7.6% and a recovery of 95.0%-107%.

Preparation and application of curcumin loaded with citric acid crosslinked chitosan-gelatin hydrogels.

While oral administration offers safety benefits, its therapeutic efficacy is hindered by various physiological factors within the body. In this study, a novel approach was explored using a matrix consisting of 2 % chitosan and 2 % gelatin, with citric acid (CA) serving as a green cross-linking agent (ranging from 0.4 % to 1.0 %), and curcumin (Cur) as the model drug to formulate hydrogel carriers. The results showed that a 0.4 % CA concentration, the hydrogel (CGA0.4) reached swelling equilibrium in deionized water within 40 min, exhibiting a maximum swelling index was 539 g/g. The addition of Cur to the CGA hydrogel (CGACur) notably enhanced release efficiency, particularly in simulated intestinal fluid, where Cur release rates exceeded 40 % within 100 min compared to below 8 % in other solutions. Among these hydrogels, CGA0.4Cur exhibited the fastest degradation rate in the combined solution, reaching >90 % degradation after 7 days. Additionally, Cur and CA demonstrated positive effects on the tensile strength, antioxidant activity and antibacterial activity of hydrogels. Compare to the bioaccessibility of CGC (27 %), those of CGACur had increased to over 34 %. These findings offer provide theoretical support for CA-crosslinked chitosan/gelatin gels in delivering hydrophobic bioactive molecules and their application in intestinal drug delivery system.

Polyvinyl alcohol/kappa-carrageenan-based package film with simultaneous incorporation of ferric ion and polyphenols from Capsicum annuum leaves for fruit shelf-life extension.

Bio-based food packaging materials have elicited growing interests due to their great degradability, high safety and active biofunctions. In this work, by simultaneously introducing the polyphenolic extracts from Capsicum annuum leaves and ferric ion (Fe3+) into the Polyvinyl alcohol/kappa-carrageenan (PVA/κ-carrageenan)-based film-forming matrix, an active package film was developed, with the purpose to improve the food shelf life. The experimental results indicated that the existence of Fe3+ can not only improve the mechanical properties owing to the multiple dynamic coordinated interactions, but also endow the composite films with excellent fire-retardancy. Moreover, the composite films could display excellent UV resistant performance, water vapor/oxygen gas barrier properties and antioxidant activities with the corporation of polyphenols. In particular, the highest DPPH and ABTS radical scavenging capacities for composite film (PC-PLP7 sample) were evaluated to be 82.5 % and 91.1 %, respectively. Higher polyphenol concentration is favorable to the bio-functions of the materials. Benefitting from these features, this novel kind of films with a dense and steady micro-structure could be further applicated in fruit preservations, where the ripening bananas were ensured with the high storage quality. This integration as a prospective food packaging material provides an economic and eco-friendly approach to excavate the high added-values of biomass.

Assembly of single-stranded polydeoxyadenylic acid and ß-glucan probed by the sensing platform of graphene oxide based on the fluorescence resonance energy transfer and fluorescence anisotropy.

Based on the fluorescence resonance energy transfer (FRET) and fluorescence anisotropy (FA), the present study reported proof-of-principle for a highly sensitive and rapid detection technique that can be precisely utilized for investigating the self-assembly of polydeoxyadenylic acid (poly(dA)) and ß-glucan, and the interactions of the poly(dA)-ß-glucan complex on the surface of graphene oxide (GO). Due to the noncovalent assembly of fluorescein amidite (FAM)-labeled poly(dA) and GO via π-π stacking, the fluorescence of (FAM)-labeled poly(dA) as a molecular aptamer beacon (MAB) was completely quenched by GO. Conversely, the addition of single-stranded lentinan (s-LNT) resulted in the significant restoration of fluorescence due to the formation of poly(dA)-s-LNT complexes with a stiff rod-like structure, which had a weak affinity to GO and kept the dyes away from GO. However, relatively weak fluorescence restoration was observed by adding another single-stranded curdlan (s-CUR) for positive control, indicative of complex formation with higher binding ability to GO. The fluorescence anisotropy (FA) was also combined to confirm the occurrence with different increments of anisotropy relative to the free poly(dA), which could be conveniently extended for detecting the assembly of other biomolecules with higher sensitivity.

Low-cost preparation of photoluminescent carbon nanodots and application as peroxidase mimetics in colorimetric detection of H2O2 and glucose.

A low-cost and facile preparation of water-soluble photoluminescent carbon nanodots (CDs) with a quantum yield of approximately 12.4% by hydrothermal method utilizing the leaves of Olea Europaea, a large number of planted trees in southwest of China, as a carbon source is developed for the first time. The prepared photoluminescent CDs not only show favorable photoluminescent properties, but also possess intrinsic peroxidase-like activity for colorimetric and UV-Vis absorption detection of hydrogen oxide (H2O2) and glucose. This sensing system exhibits excellent sensitivity toward H2O2 and glucose with the limit of detection as low as 0.6 microM and 5.2 microM. The practical use of this system for glucose determination in serum samples is also demonstrated successfully. The stability and low cost of photoluminescent CDs make them a powerful tool for a wide range of potential applications in biochemical analysis.

Tough and stretchable all-κ-carrageenan hydrogel based on the cooperative effects between chain conformation transition and stepwise mechanical training.

The traditional κ-carrageenan (κCG)-based hydrogel obtained from hot water can rupture easily under mechanical loading. To address this vulnerability, here we presented a robust all-κCG hydrogel without employing the second synthetic network. By simply regulating the polymer chains from random coil to stiff chain conformation in NaOH/urea solvent system via the freeze-thawing process, the as-prepared hydrogel with homogeneous structure can display an enhanced stretchability from 42.1 to 156 %, while maintaining the similar fracture stress. Moreover, upon the stepwise mechanical training and subsequent incubation in KCl aqueous solution, more helical segments of κCG were aligned and involved into the association domains, thus leading to the increment in both the crystallinity and anisotropy. Consequently, a fast self-strengthening behavior occurred, and a more stretchable (fracture strain up to 396 %), strong (stress âˆ¼ 0.55 MPa) and tough (∼1.52 MJ m-3) κCG hydrogel was obtained. In comparison to the traditional one, the fracture strain and toughness are increased by 8.5 and 11.5 times, respectively. In addition, this κCG hydrogel can demonstrate good recovery and shape-memory behaviors under medium deformation. Hence, this tough all-κCG hydrogel is expected to be tailored into the biomaterials as the wearable device, artificial tendon, and cartilage in the future.

Preparation, physicochemical and application evaluation of raspberry anthocyanin and curcumin based on chitosan/starch/gelatin film.

Raspberry anthocyanin (RA) from Rubus idaeus L. (Rosaceae) and curcumin (Cur) from Curcuma longa L. (Zingiberaceae) can effectively improve the physicochemical properties of composite films, and as bioactive pigment components, they can impart pH-responsive properties to the film. In this study, RA and Cur were added to chitosan/starch/gelatin composite film (CSG) to prepare CSG-RA, CSG-Cur, CSG-RA/Cur82 and CSG-RA/Cur73 color films by solution casting method. The color films could change color under different pH conditions and had higher antioxidant activities using ABTS (2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)) assay. The results from fourier transform infrared spectroscopy and scanning electron microscopy showed that RA and Cur were well dispersed in the CSG matrix and improved the structure of the composite films. The hydrophobic Cur increased the tensile strength from 6 Mpa (CSG) to 14 Mpa (CSG-Cur), but reduced the elongation at break from 55 % (CSG) to 40 % (CSG-Cur). These color films had a good fresh-keeping effect and freshness monitoring, in particular, CSG-RA/Cur73, had the better opacity, water solubility, thickness, moisture content and water vapor permeability than the other films. Briefly, binary pigment films had the potential to become a pH-sensitive indicator/packing film.

Chitin/egg shell membrane@Fe3O4 nanocomposite hydrogel for efficient removal of Pb2+ from aqueous solution.

The development of adsorbents by using the byproducts or waste from large-scale industrial and agricultural production is of great significance, and is considered to be an economic and efficient strategy to remove the heavy metals from polluted water. In this work, a novel chitin/EM@Fe3O4 nanocomposite hydrogel was obtained from a NaOH/urea aqueous system, where the proteins of egg shell membrane and Fe3O4 nanoparticles were chemically bonded to chitin polymer chains with the help of epichlorohydrin. Due to the existence of a large number of -NH2, -OH, -CONH-, -COOH and hemiacetal groups, the adsorption efficiency for Pb2+ into the absorbent was dramatically enhanced. The experimental results revealed that the adsorption behavior strongly depends on various factors, such as initial pH, initial Pb2+ concentration, incubation temperature and contact time. The kinetic experiments indicated that the adsorption process for Pb2+ in water solution agreed with the pseudo-second-order kinetic equation. The film diffusion or chemical reaction is the rate limiting process in the initial adsorption stage, and the adsorption of Pb2+ into the nanocomposite hydrogel can well fit the Langmuir isotherm. Thermodynamic analysis demonstrated that such adsorption behaviors were dominated by an endothermic (ΔH° > 0) and spontaneous (ΔG° < 0) process.

Catalytic effect of ReAu nanoalloy on the Te particle reaction and its application to resonance scattering spectral assay of CA125.

ReAu nanoparticles with a molar ratio of 2:8 Re and Te nanoparticles were prepared by NaBH4 reduction. In HCl medium at 65°C, ultratrace Re, Te and ReAu bimetallic nanoparticles strongly catalyzed the slow reaction between Sn(II) and Te(VI) to form Te particles, which exhibited the strongest resonance scattering (RS) peak at 782 nm. As the amount of nanocatalyst increased, the RS intensity at 782 nm (I(782 nm) ) increased linearly, and the increase in intensity ΔI(782 nm) was linear to the ReAu, Re and Te concentrations in the ranges 0.07-9.0, 0.01-4.5 and 30-1200 nM, respectively. As a model, a ReAu immunonanoprobe catalytic Te-particle resonance scattering spectral (RSS) method was established for detection of CA125, using ReAu nanoparticle labeling CA125 antibody (CA125Ab) to obtain an immunonanoprobe (ReAuCA125Ab) for CA125. In pH 7.6 citric acid-Na2HPO4 buffer solution, ReAuCA125Ab aggregated nonspecifically. Upon addition of CA125, the immunonanoprobe reacted with it to form ReAuCA125Ab-CA125 dispersive immunocomplex in the solution. After the centrifugation, the supernatant containing the immunocomplex was used to catalyze the reaction of Te(VI)-Sn(II) to produce the Te particles that resulted in the I(782 nm) increasing. The ΔI(782 nm) was linear to CA125 concentration (C(CA125)) in the range 0.1-240 mU/mL. The regression equation, correlation coefficient and detection limit were ΔI(782 nm) = 1.61 C(CA125) + 1.5, 0.9978 and 0.02 mU/mL, respectively. The proposed method was applied to detect CA125 in serum samples, with satisfactory results.

A highly sensitive resonance scattering spectral assay for carcinoembryonic antigen using immunonanogold as probe and nanocatalyst of NH2(OH-Cu(II) particle reaction.

Nanogold of 10 nm was used to label carcinoembryonic antigen antibody (CEAAb) to prepare a probe (Au-CEAAb) for carcinoembryonic antigen (CEA). In a Na2HPO4-NaH2PO4 buffer solution of pH 6.8, CEA reacted with Au-CEAAb to form a big Au-CEAAb-CEA immunocomplex that can be removed by centrifugation. The unreacted Au-CEAAb in the centrifugal supernatant exhibited catalytic effect on the Cu2O particle reaction, and the Cu2O particles displayed a resonance scattering (RS) peak at 602 nm. When CEA increased, the RS intensity at 602 nm decreased, and the decreased RS intensity (ΔI (602 nm)) was linear to CEA concentration (C (CEA)) in the range of 0.02-12 ng mL(-1), with the regression equation of ΔI (602 nm) = 27.1 C (CEA) + 3.3, correlation coefficient of 0.9978 and detection limit of 3 pg mL(-1) CEA. The proposed method was applied to detect CEA in real samples, with satisfactory results.