81 research outputs found
DataSheet1_Optimization and preparation of a compound cod liver oil film former agent: an orthogonal design.docx
Background: Cod liver oil has anti-inflammatory properties and could help regulate recurrent aphthous stomatitis (RAS). An orthogonal experiment was used to evaluate and improve the dosage form of compound cod liver oil, which has replaced the previously used liniment preparation based on film method.Methods: An orthogonal experiment was adopted, and the appearance and film-forming time of the film coating agents were used as indicators. The optimal ratio in the preparation process for the compound cod liver oil film agent was then optimized. A method for determination of compound cod liver oil film was established using High-Performance Liquid Chromatography (HPLC).Results: The results indicate that the blank films prepared using 55Â mg polyvinyl alcohol (PVA) (PVA low), 45Â mg of PVA (PVA medium), and 10Â mg glycerol had the optimal performance, which was defined as PVAa. The drug-carrying film prepared from 3Â mL PVAa (i.e., film-forming material with the optimal proportion), 30Â mg dexamethasone acetate, and 30Â mg metronidazole had the optimal performance. The verified sample has a complete and smooth appearance, uniform thickness and color, and no evident bubbles, which meets the requirements for a film agent defined in the Chinese Pharmacopoeia, 2020 edition. HPLC was used to determine the major components: dexamethasone acetate, metronidazole, and dyclonine hydrochloride, and the optimal separation effect was obtained. The method has advantages of good specificity, good linear results, high recovery rate, and good repeatability.Conclusion: This study proposes an optimized compound cod liver oil film former agent and preparation method. The results indicate that the compound cod liver oil film former agent had good performance, reflecting the high feasibility of this research method. The detection method of compound cod liver oil film was established by HPLC. The method was feasible, and the validity and stability of the formulation and preparation technology were guaranteed. The role of the newly developed agent in patients with RAS should be investigated further.</p
Reusable and Dual-Potential Responses Electrogenerated Chemiluminescence Biosensor for Synchronously Cytosensing and Dynamic Cell Surface N‑Glycan Evaluation
A novel reusable
and dual-potential responsive electrogenerated
chemiluminescence (ECL) biosensor was fabricated for synchronous detection
of cancer cells and their surface N-glycan. In this strategy, a cancer
cell recognized aptamer hybridized with a capture DNA was immobilized
on electrochemically reduced MoS<sub>2</sub> nanosheets, and RuÂ(phen)<sub>3</sub><sup>2+</sup> as ECL probes was intercalated into the grooves
of the double-strand DNA. In the presence of target cells, the capture
DNA and RuÂ(phen)<sub>3</sub><sup>2+</sup> were released from the electrode
interface owing to the specific interaction between cancer cells and
the aptamer. Meanwhile, concanavalin A (Con A), a mannose binding
protein, and a conjugated gold nanoparticle modified graphite-C<sub>3</sub>N<sub>4</sub> (Con A@Au-C<sub>3</sub>N<sub>4</sub>) was used
as a negative ECL nanoprobe and applied for the cell surface N-glycan
evaluation owing to the excellent ECL properties of g-C<sub>3</sub>N<sub>4</sub> at negative potential. The cytosensing and cell surface
N-glycan evaluation could be simultaneously realized with high sensitivity
and excellent selectivity based on the ratio of ECL intensity between
the negative potential and positive potential (ΔECL<sub>n</sub>/ΔECL<sub>p</sub>), avoiding the traditional routing cell counting
procedures. Moreover, the aptamer modified electrode can be regenerated
in the presence of capture DNA solutions for cyclic utilization. As
a proof-of-concept, the ECL cytosensor showed excellent performances
for the analysis of the MCF-7 cancer cell and its surface N-glycan
evaluation in human serum samples. The reusable and dual potential
response ECL biosensor endows a feasibility tool for clinical diagnosis
and drug screening especially in complex biological systems
Intrinsic Point Defects in Inorganic Cesium Lead Iodide Perovskite CsPbI<sub>3</sub>
Cesium lead iodide
(CsPbI<sub>3</sub>) has recently emerged as
a promising solar photovoltaic absorber. However, the cubic perovskite
(α-phase) remains stable only at high temperature and reverts
to a photoinactive nonperovskite (δ-phase) CsPbI<sub>3</sub> at room temperature. In this work, the formation energies and transition
energy levels of intrinsic point defects in γ- (more stable
than α-phase) and δ-phases have been studied systematically
by first-principles calculations. It is found that CsPbI<sub>3</sub> exhibits a unipolar self-doping behavior (p-type conductivity),
which is in contrast to CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub>. Most of the intrinsic defects induce deeper transition energy levels
in δ-phase than in γ-phase. This is due to the small Pb–I–Pb
bond angles in δ-phase that results in the weak antibonding
character of valence band maximum (VBM). However, the strong antibonding
character of VBM plays a critical role in keeping defect tolerance
in semiconductors. Therefore, these results indicate the importance
of the large metal–halide–metal bond angle for the performance
of perovskite solar cells
Simulation Studies on Robust Contacts in V<sub>2</sub>CT<sub>2</sub>/MoSi<sub>2</sub>N<sub>4</sub> (TO, F, OH) van der Waals Heterojunction Nanostructures: Implications for Optoelectronic Devices
Research on metal electrode–semiconductor contacts
has primarily
focused on adjusting the Schottky barrier height (SBH), with little
attention paid to the stability of electronic properties upon contact.
Herein, we comprehensively investigate the sensitivity of contact
properties to the external electric field (ΔE), out-plane strain (Δd), and in-plane biaxial
strain (Δδ) taking the V2C(T2)/MoSi2N4 (TO, OH, F) van der Waals heterojunction
(vdWH) as an example. Our findings suggest that surface functionalization
(-T termination) is a powerful tool for controlling contact characteristics.
Importantly, when ΔE0.3 V/nm, Δd = −0.1 Å, and Δδ < 0%, the
intrinsic contact properties of V2C/MoSi2N4 may be changed. However, V2CT2/MoSi2N4 can maintain the intrinsic contact properties
over a wider range of ΔE, Δd, and Δδ. Furthermore, we design a p–i–n
optoelectronic transistor (V2CO2/MoSi2N4/V2CO2H2), which has
excellent tunneling probability (100%), photocurrent density (11.336
A/m2), responsivity (0.322 AW–1), and
external quantum efficiency (71.061%). Our work not only serves as
a reference for eliminating the error of information transmission
and the degradation of device performance caused by contact property
sensitivity to electric field and strain but also provides theoretical
guidance for the experimental design of high-performance MoSi2N4-based optoelectronic devices
Additional file 1: of Relationship between serum uric acid level and mild cognitive impairment in Chinese community elderly
Appendix Tables (appendix Table S1 and S2). Multiple linear and logistic regression of SUA level for MMSE score and MCI prevalence for participants without cerebral vascular disease or without kidney diseases. We ascertained the association of SUA level with MMSE score and MCI prevalence in the sensitivity analysis (Appendix Table S1 and S2). When participants with cerebral vascular disease (n = 267, 12.7%) and kidney disease (n = 105, 5.0%) were excluded, the βs and ORs were similar with that in the Table 4 (all participants). (DOC 62 kb
DNA Assembled Gold Nanoparticles Polymeric Network Blocks Modular Highly Sensitive Electrochemical Biosensors for Protein Kinase Activity Analysis and Inhibition
A highly sensitive electrochemical
biosensor was built for the
detection of kinase activity based on the DNA induced gold nanoparticles
(AuNPs) polymeric network block signal amplification. In this strategy,
the DNA<sub>1</sub> conjugated AuNPs were integrated with the phosphorylated
peptide by Zr<sup>4+</sup> and assembled into DNA-AuNPs polymeric
network block by the hybridization of cDNA with each side sequences
of DNA<sub>1</sub> and joint DNA<sub>2</sub>. The kinase activity
was determined by the amperometric responses of [RuÂ(NH<sub>3</sub>)<sub>6</sub>]<sup>3+</sup> absorbed on the network block by electrostatic
interaction. Due to its excellent electroactivity and high accommodation
of the DNA-AuNPs polymeric network block for [RuÂ(NH<sub>3</sub>)<sub>6</sub>]<sup>3+</sup>, the current signal was significantly amplified,
affording a highly sensitive electrochemical analysis of kinase activity.
The as-proposed biosensor presents a low detection limit of 0.03 U
mL<sup>–1</sup> for protein kinase A (PKA) activity, wide linear
range (from 0.03 to 40 U mL<sup>–1</sup>), and excellent stability
even in cell lysates and serum samples. This biosensor can also be
applied for quantitative kinase inhibitor screening. Finally, the
PKA activities from BE4S-2B, A549, and MCF-7 cell lysates were further
analyzed, which provided a valuable strategy in developing a high-throughput
assay of in vitro kinase activity and inhibitor screening for clinic
diagnostics and therapeutics
Reusable Silicon-Based Surface-Enhanced Raman Scattering Ratiometric Aptasensor with High Sensitivity, Specificity, and Reproducibility
Rapid,
sensitive, and accurate detection of adenosine triphosphate
(ATP), the primary energy molecule, is critical for the elucidation
of its unique roles in cell signaling and many cellular reactions.
Up to date, a major challenge is still remaining for fabricating surface-enhanced
Raman scattering (SERS) aptamer sensors (aptasensors) suitable for
accurate and reliable quantification of ATP. Herein, we develop the
ratiometric silicon SERS aptasensor for ATP detection, which is made
of uniform silver nanoparticles (Ag NPs)-modified silicon wafer (Ag
NPs@Si), followed by the functionalization with double-stranded DNA
(dsDNA I). The dsDNA I is formed by the aptamer and its complementary
DNA (cDNA), which contains two independent segments (e.g., 5′-Cy3-labeled
DNA-C1, 3′-ROX-labeled DNA-C2). In the presence of ATP, ROX–DNA-C2
is dissociated from dsDNA I due to the formation of aptamer/ATP complex,
leading to the attenuation of ROX signals, and meanwhile, Cy3 signals
remain constant ascribed to the formation of dsDNA II caused by the
supplementation of aptamer. As a result, ratiometric signals of the
ratio of ROX intensity to Cy3 intensity (<i>I</i><sub>ROX</sub>/<i>I</i><sub>Cy3</sub>) can be achieved. Of particular
significance, the developed ATP aptasensor features excellent reproducibility
[e.g., the relative standard deviation (RSD) is less than ∼4%,
comparable or superior to that of previously reported aptasensors],
ultrahigh sensitivity [e.g., the detection of limit (LOD) reaches
9.12 pM, lower than that of other reported ATP SERS aptasensors],
as well as good recyclability (e.g., ∼9.3% of RSD values of
ratiometric signals within three cycles)
Silk Nanofibers as Robust and Versatile Emulsifiers
Peptides have been
extensively studied as emulsifiers due to their sequence and size
control, biocompatibility, versatility, and stabilizing capacity.
However, cost and mass production remain the challenges for broader
utility for these emulsifiers. Here we demonstrate the utility of
silk fibroin nanofibers as emulsifiers, with superior functions to
the more traditional peptide emulsifiers. This silk nanofiber system
is universal for different oil phases with various polarities and
demonstrates control of microcapsule size through tuning the ratio
of silk fibroin nanofiber solutions to oils. Besides the improved
stabilizing capacity to peptides, these silk fibroin nanofibers endow
additional stability to the emulsions formed under high salt concentration
and low pH. Highly efficient encapsulation of biomarkers through interfacial
networks suggests potential applications in therapeutics, food, and
cosmetics. Compared to peptide emulsifiers, these silk fibroin nanofibers
offer advantages in terms of cost, purification, and production scale,
without compromising biocompatibility, stabilizing capacity, and versatility
In Situ Live-Cell Nucleus Fluorescence Labeling with Bioinspired Fluorescent Probes
Fluorescent imaging
techniques for visualization of nuclear structure
and function in live cells are fundamentally important for exploring
major cellular events. The ideal cellular labeling method is capable
of realizing label-free, in situ, real-time, and long-term nucleus
labeling in live cells, which can fully obtain the nucleus-relative
information and effectively alleviate negative effects of alien probes
on cellular metabolism. However, current established fluorescent probes-based
strategies (e.g., fluorescent proteins-, organic dyes-, fluorescent
organic/inorganic nanoparticles-based imaging techniques) are unable
to simultaneously realize label-free, in situ, long-term, and real-time
nucleus labeling, resulting in inevitable difficulties in fully visualizing
nuclear structure and function in live cells. To this end, we present
a type of bioinspired fluorescent probes, which are highly efficacious
for in situ and label-free tracking of nucleus in long-term and real-time
manners. Typically, the bioinspired polydopamine (PDA) nanoparticles,
served as fluorescent probes, can be readily synthesized in situ within
live cell nucleus without any further modifications under physiological
conditions (37 °C, pH ∼7.4). Compared with other conventional
nuclear dyes (e.g., propidium iodide (PI), Hoechst), superior spectroscopic
properties (e.g., quantum yield of ∼35.8% and high photostability)
and low cytotoxicity of PDA-based probes enable long-term (e.g., 3
h) fluorescence tracking of nucleus. We also demonstrate the generality
of this type of bioinspired fluorescent probes in different cell lines
and complex biological samples
One-Dimensional Fluorescent Silicon Nanorods Featuring Ultrahigh Photostability, Favorable Biocompatibility, and Excitation Wavelength-Dependent Emission Spectra
We
herein report a kind of one-dimensional biocompatible fluorescent
silicon nanorods (SiNRs) with tunable lengths ranging ∼100–250
nm, which can be facilely prepared through one-pot microwave synthesis.
In addition to the strong fluorescence (quantum yield value: ∼15%)
and negligible toxicity, the resultant SiNRs exhibit excitation wavelength-dependent
photoluminescence whose maximum emission wavelength ranges from ∼450
to ∼600 nm under serial excitation wavelengths from 390 to
560 nm, providing feasibility for multicolor biological imaging. More
significantly, the SiNRs are ultrahighly photostable, preserving strong
and nearly unchanged fluorescence under 400 min high-power UV irradiation,
which is in sharp contrast to severe fluorescence quenching of organic
dyes (e.g., FITC) or II–VI quantum dots (QDs) (e.g., CdTe QDs
and CdSe/ZnS QDs) within 15 or 160 min UV treatment under the same
experiment conditions, respectively. Taking advantage of these attractive
merits, we further exploit the SiNRs as a novel type of color converters
for the construction of white light-emitting diodes (LED), which is
the first proof-of-concept demonstration of LED device fabricated
using the one-dimensional fluorescent silicon nanostructures
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