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1.
Opt Express ; 32(11): 19252-19264, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38859064

RESUMO

Faced with growing demands for high-speed and reliable communication systems, optical intelligent reflecting surfaces (OIRS) have recently attracted a lot of interest in visible light communication (VLC). With potential applications in a variety of scenarios, including indoor wireless communications and the Internet of Things (IoT), OIRS is expected to have a transformative impact on optical wireless communications. However, current research is predominantly theoretical, and the hardware implementation of OIRS is insufficient. Therefore, this paper introduces an OIRS prototype based on a mirror array, which is capable of adjusting the reflected lightwave by manipulating the orientation of individual OIRS units to realize an adjustable optical wireless communication environment. Additionally, a hardware platform with a configurable control system for OIRS-based VLC has been developed in this paper. Finally, experimental results demonstrate significant improvements in the amplitude of the received signal and the signal-to-noise ratio of the developed prototype, thereby verifying the enhancement of communication efficiency and the potential of practical OIRS deployment.

2.
Appl Opt ; 63(3): 617-623, 2024 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-38294372

RESUMO

We propose an equivalent circuit model of the traveling wave electrode for lithium niobate thin film (TFLN) Mach-Zehnder modulators, in which the distributed capacitance and conformal mapping techniques are applied to calculate the microwave refractive index, microwave loss, and characteristic impedance. Their accuracies are verified by comparing with the results of the finite element method, and the relative errors are less than 3.282%, 1.776%, and 5.334%, respectively. The influence of the electrode's structural parameters on the modulation performances is analyzed, and a 3 dB modulation bandwidth around 84 GHz with an 8-mm-long traveling wave electrode is obtained.

3.
Environ Res ; 214(Pt 1): 113775, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35830912

RESUMO

The solidification/stabilization of phosphogypsum using cemented paste backfill (OCPB) provides a low-cost and alternative in-situ technique for recycling phosphogypsum stockpiles. But the OCPB is far from obtaining steady states in which the pollutants would redistribute as a response to dynamic environmental conditions. Further, the associated chemical interactions and the mineralogy information of the solubility-controlling phases of contaminants (fluorine and phosphorus) have not been thoroughly studied or fully understood. In this study, a framework coupling the chemical, mineralogical, and morphological analyses is used to determine the fluoride and phosphate retention mechanisms of immobilized OCPB. Then the pH-dependent leaching tests and numerical simulation is applied as a useful tool to identify the minerals controlling stabilized OCPB leaching behavior. The overall findings proved that aluminate-rich calcium silicate hydrates play an essential role in fluoride and phosphate retention. Both experimental and simulational acid neutralization and leaching curves indicate that the cementitious matrix works as a strong buffering material ensuring high pH conditions that are necessary for fluorine and phosphorus retention. Although discrepancies were observed in absolute fluorine and phosphorus leaching values at highly acidic conditions, the simulations are able to describe highly amphoteric leaching behavior. The simulation suggests that the aluminum species and calcium phosphates governed the solubility of fluorine and phosphorus, respectively. The results of this work would have implications for predicting the leaching behavior of OCPB in detrimental and multiple environments.


Assuntos
Fluoretos , Flúor , Sulfato de Cálcio , Fosfatos , Fósforo
4.
Phytochem Anal ; 33(6): 879-885, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35668032

RESUMO

OBJECTIVES: Acanthopanax senticosus (Rupr. & Maxim.) Harms is a medicinal and edible plant which is clinically used for the recovery and treatment of cardiovascular and central diseases. As a characteristic active pharmaceutical ingredient of Acanthopanax senticosus, eleutheroside E is the core of the therapeutic effect. Organic solvent extraction has low selectivity, low extraction rate, difficulty in separation and purification and safety risks. The purpose of this study was to extract the effective component of Acanthopanax senticosus with a new green solvent. METHODS: In this article, two kinds of deep eutectic solvents (DESs) (DES-1 and DES-2) were synthesised by heating and stirring methods. Eleutheroside E was extracted by ultrasonic extraction with two kinds of DES as extractants and quantitatively analysed by Orbitrap-tandem mass spectrometry (MS/MS). RESULTS: The main results showed that the initial polarity of the DES was similar to that of 60 to 80% ethanol and hydrogen bond donors were the main factors affecting the polarity of DES. In the test, the viscosity of DES was higher than that of ethanol, and even the addition of a small amount of water (10%) caused intermolecular hydrogen bond disruption and redistribution of the solvent, resulting in a significant decrease in solvent viscosity. The solvents in the test group were stable after standing at 5°C in the dark for 100 days. The extraction rate of eleutheroside E by DES solvent was 5-6 times higher than that by ethanol. DES-1 and DES-2 can efficiently extract eleutheroside E. CONCLUSION: This study developed a new method for the application of the green extraction of eleutheroside E with certain practical significance.


Assuntos
Eleutherococcus , Eleutherococcus/química , Etanol , Glucosídeos , Lignanas , Solventes , Espectrometria de Massas em Tandem , Tecnologia
5.
Sports Med ; 2024 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-38874898

RESUMO

BACKGROUND: Currently, most studies on the health benefits of traditional Chinese exercises on type 2 diabetes mellitus have explored the effects of a single type of traditional Chinese exercise on type 2 diabetes. Although a previous study evaluated the combined clinical effects of traditional Chinese exercises on type 2 diabetes, the studies included in that review were deficient in their study design. In addition, previous studies have not explored the ideal exercise dose that should be taken by patients with type 2 diabetes when performing traditional Chinese exercises. OBJECTIVE: To understand whether the findings of previous systematic reviews and meta-analyses are still applicable and to try to address the deficiencies in the previous review, this review conducted a meta-analysis of existing randomized controlled trials to investigate the impact of traditional Chinese exercises on glycemic control with type 2 diabetes. METHODS: The literature was searched in seven Chinese and English databases. Randomized controlled trials published in English and Chinese, from database inception to March 2023, were included in this review. Two reviewers independently reviewed the search results, extracted the data, and assessed the risk of bias. A meta-analysis of the included studies was conducted using Rev Man 5.4 and Stata 15.1 software. Heterogeneity was investigated using a sensitivity analysis, a subgroup analysis, and a meta-regression analysis. Pre-determined subgroups included the duration of the intervention, frequency of exercise, and duration of the single exercise session. RESULTS: A total of 31 randomized controlled trials (2077 subjects) were selected in this review. The meta-analysis revealed that traditional Chinese exercises were more effective than control groups in lowering glycated hemoglobin (Z = 6.06; mean difference [MD] = - 0.64, 95% confidence interval [CI] - 0.85, - 0.44; P < 0.00001), fasting blood glucose (Z = 7.81; MD = - 0.82, 95% CI - 1.03, - 0.62; P < 0.00001), 2-h plasma glucose (Z = 5.61; MD = - 1.03, 95% CI - 1.39, - 0.67; P < 0.00001), total cholesterol (Z = 4.23; MD = - 0.37, 95% CI - 0.54, - 0.20; P < 0.0001), high-density lipoprotein cholesterol (Z = 5.94; MD = 0.12, 95% CI 0.08, 0.16; P < 0.00001), low-density lipoprotein cholesterol (Z = 6.20; MD = - 0.34, 95% CI - 0.44, - 0.23; P < 0.00001), and triglyceride levels (Z = 3.74; MD = - 0.44, 95% CI - 0.67, - 0.21; P = 0.0002) among patients with type 2 diabetes. CONCLUSIONS: Traditional Chinese exercises can significantly improve blood glucose and lipid levels in patients with type 2 diabetes. When performing traditional Chinese exercise interventions for type 2 diabetes, it is recommended that exercise programs are designed for 30-50 min/session, 4-5 sessions/week for at least 3 months.

6.
J Pharm Biomed Anal ; 240: 115929, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38147703

RESUMO

A quantitative structure retention relationship (QSRR) method was developed to identify flavonoid isomers auxiliary using an ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method based on the linear relationships between the Ln(k') values of flavonoids and their hydrogen bonding energy (XAH) and dissolution energy (ES). Chromatographic separation was achieved with a Hypersil GOLD C18 (100 mm × 2.1 mm, 1.9 µm) column and Agilent SB-C18 (2.1 ×50 mm, 1.8 µm) column on a Dionex Ultimate 3000 RSLC chromatograph. Compounds were eluted isocratically using a mobile phase containing 0.1% formic acid/water solution and methanol at a ratio of 55:45 (v/v). Mass spectrometry was performed in the negative and positive ionization modes on a Thermo Fisher Q Exactive Orbitrap mass spectrometer equipped with an electrospray ionization interface. The established QSRR model was Ln(k') = 5.6163 + 0.0469ES - 0.0984XAH, with a determination coefficient (R2) of 0.9981, adjusted determination coefficient (adjR2) of 0.9976, and corrected root mean square error of 0.0682. The determination coefficient of the leave-one-out (LOO) cross-validation (Q2LOO) was 0.9976, and the cross-verification root mean square error was 0.0754. Simulated samples containing 7 flavonoids were used to validate the feasibility of the method. The classical method (UHPLC-MS/MS combined the CD software and the mzCloud, mzVault and Chemspider databases) was used to identify the seven flavonoids in the simulated samples. This classic identification strategy cannot provide accurate identification results, which provided multiple identification results for each compound in the simulated samples. On the basis of the results, the 7 flavonoids were accurately identified by the established QSRR model, and the reference standards were used to validate it. The relative error of retention time(RE(tR)) between the model calculation and experimental results was less than 10%. This method effectively complements and improves the classical methods, that UHPLC-MS/MS combined the CD software and the mass spectra databases were used to identify flavonoids identification.


Assuntos
Medicamentos de Ervas Chinesas , Espectrometria de Massas em Tandem , Espectrometria de Massas em Tandem/métodos , Flavonoides , Cromatografia Líquida de Alta Pressão/métodos , Padrões de Referência
7.
Chemosphere ; 313: 137412, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36455381

RESUMO

In-situ remediating phosphogypsum (PG) for cemented paste backfill (CPB) in the contaminated site is economic management for promoting sustainable developments in the phosphate industry. This study concerns the combined use of NaOH pretreatment and ground-granulated blast furnace slag (GGBFS) additives to promote the solidification/stabilization of PG with a lower carbon footprint pathway. According to physico-chemical analyses, the NaOH pretreatment effectively removed approximately 95% of F within the PG, which may originally be present as sparingly soluble fluorides or coexisting with silicates. The micro mineralogical characterization illustrates that the pretreatment can accelerate the early age hydration, with more hydration products observed, including calcium silicate hydrates and ettringite, effective F and P retention candidates. Whereas the incorporation of GGBFS plays an essential role in promoting the generation of additional cement hydrates at the following stages. The macro mechanical performance analysis indicates that the mixtures of pretreated-PG-OPC-GGBFS exhibit an excellent mechanical performance satisfying the design criteria. Subsequent elemental mapping and toxicity characteristic leaching procedures demonstrate that this combined approach has a competitive F and P immobilization ability compared to the typical OPC binder and individual GGBFS addition. The newly formed phases effectively controlled the concentration of F and P through adsorption, incorporation, or encapsulation. Objectively, the proposed methodology can be a promising candidate pathway for extrapolating the in-situ immobilization of PG. This study opens up new perspectives for synergetically recycling PG and GGBFS in a profitable and low carbon footprint way.


Assuntos
Sulfato de Cálcio , Hidróxido de Sódio
8.
Diabetol Metab Syndr ; 15(1): 232, 2023 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-37957775

RESUMO

BACKGROUND: Most studies about exercise interventions for patients with type 2 diabetes mellitus (T2DM) have been conducted in hospitals or labs, but it is unclear whether study findings from this specific condition can be generalised to real-life T2DM communities. If patients with T2DM can exercise on their own or with family members, it may also reduce the need for patient supervision by medical staff, thereby reducing the burden of medical treatment and improving condition management's cost-effectiveness and practicability. Much of the current research on exercise interventions for T2DM was focused on the type of exercise and less on the mode of management, so we aimed to examine the effect of exercise interventions based on family management or self-management on glycaemic control in patients with T2DM. METHODS: Articles were searched from eight Chinese and English databases. Randomized control trials (RCTs) published in English and Chinese, from inception to October 17, 2022, were included in this review. The methodological quality of the included studies was assessed using the RCT risk of bias assessment tool provided by the Cochrane Collaboration's tool. Meta-analysis was performed using Rev Man 5.4 and Stata 15.0 software. Heterogeneity was investigated using sensitivity analysis and subgroup analyses. Publication bias was tested by funnel plot and Egger's asymmetry tests. RESULTS: A total of 10 studies with a total of 913 subjects were finally included in this review. The Meta-analysis showed that exercise interventions based on family management or self-management were more effective than control groups in reducing HbA1c (Z = 3.90; 95% CI MD = - 0.81; - 1.21 to - 0.40; P < 0.0001), fasting glucose (Z = 4.63; 95% CI MD = - 1.17; - 1.67 to - 0.68; P < 0.00001), 2-h plasma glucose (Z = 5.53; 95% CI MD = - 1.84; - 2.50 to - 1.19; P < 0.00001), and Low-density lipoproteins levels (Z = 3.73; 95% CI MD = - 0.38; - 0.58 to - 0.18; P = 0.0002). CONCLUSIONS: Exercise interventions based on family management or self-management can significantly reduce glycosylated haemoglobin, fasting glucose, 2-h plasma glucose, and Low-density lipoproteins levels in patients with T2DM, which can effectively delay disease progression and reduce the risk of developing complications. In the future, for exercise interventions based on family or self-management, this review recommended that exercise intervention programmes should be formulated according to 30-60 min per session, more than three times per week, for more than six months of aerobic exercise or aerobic combined with resistance exercise.

9.
J Mass Spectrom ; 55(5): e4496, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31914483

RESUMO

Coumarin is one of the basic structures of naturally oxygen heterocyclic compound, which was investigated in this paper for its gas-phase fragmentation behaviors using electrospray quadrupole extractive orbitrap mass spectrometry in the positive mode. The possible fragmentation pathways were proposed based on electrospray ionization (ESI)- mass spectrometry (MS)/MS data and theory calculation. The elimination of two CO and CO2 was observed for protonated coumarin, which was followed by the formation of a stabilized seven-, six-, and five-membered ring carbocation by loss of C2H2. The possible protonation sites occurred at Oxygen 11 atom of coumarin were the main fragmentation pathways. The relative abundance of characteristic fragment ions and the energy-resolved breakdown curves were used to confirm the cleavage mechanism of protonated coumarin. The methodology and results of present work would contribute to the chemical structure identification of other coumarins.

10.
J Mater Chem B ; 3(16): 3195-3200, 2015 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-32262313

RESUMO

A pH-sensitive acyclic enediyne (1) was synthesized for efficient DNA-cleavage and tumor cell suppression. Unlike other acyclic enediynes, this novel enediyne transforms into a highly reactive enediyne (2) in an acidic environment only, which undergoes Bergman cyclization spontaneously at ambient temperature. An EPR study on the enediyne 2 confirmed the generation of free radicals through Bergman cyclization. The activated enediyne induced DNA-cleavage and exhibited cytotoxicity towards various tumor cells under the action of diradicals arising from spontaneous Bergman cyclization at physiological temperature. These findings suggest a novel strategy of anticancer drug design, where the activation of the silent compound takes place under the acidic environment inside the tumor cells.

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