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1.
Inorg Chem ; 63(27): 12498-12505, 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38912702

RESUMEN

Dimension and solvent molecules affect the performance of energetic metal-organic frameworks (EMOFs). High-dimensional EMOFs are usually characterized by high stability and low sensitivity due to their complex network structure. However, solvent molecules affect the detonation performance of EMOFs, and these molecules may be removed at low temperatures, resulting in structural collapse and affecting the stability of EMOFs. In this work, zero-dimensional (0D) Co(AFTO)2·(H2O)2 (EMOF 1) and Ni(AFTO)2·(H2O)2 (EMOF 2) with coordinated water molecules and [Co(AFTO)2]n·EtOH (EMOF 3) and [Ni(AFTO)2]n (EMOF 4) (AFTO = 5-(4-amino-furazan-3-yl)-1-hydroxytetrazole) with high-dimensional structure were synthesized using hydrothermal and self-assembly methods in ethanol, respectively. Structural and performance tests show that EMOF 3 and 4 exhibit remarkable thermal stability and low mechanical sensitivity. This method is a simple, effective, and green technique for synthesizing high-dimensional EMOFs with high stability through self-assembly in ethanol solution. In addition, EMOF 3 and 4 can be used as primary green laser explosives.

2.
Nat Commun ; 15(1): 946, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38297005

RESUMEN

Parity-time (PT) symmetry has been unveiling new photonic regimes in non-Hermitian systems, with opportunities for lasing, sensing and enhanced light-matter interactions. The most exotic responses emerge at the exceptional point (EP) and in the broken PT-symmetry phase, yet in conventional PT-symmetric systems these regimes require large levels of gain and loss, posing remarkable challenges in practical settings. Floquet PT-symmetry, which may be realized by periodically flipping the effective gain/loss distribution in time, can relax these requirements and tailor the EP and PT-symmetry phases through the modulation period. Here, we explore Floquet PT-symmetry in an integrated photonic waveguide platform, in which the role of time is replaced by the propagation direction. We experimentally demonstrate spontaneous PT-symmetry breaking at small gain/loss levels and efficient control of amplification and suppression through the excitation ports. Our work introduces the advantages of Floquet PT-symmetry in a practical integrated photonic setting, enabling a powerful platform to observe PT-symmetric phenomena and leverage their extreme features, with applications in nanophotonics, coherent control of nanoscale light amplification and routing.

3.
Front Genet ; 14: 1219894, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37600656

RESUMEN

Objectives: Bone immune disorders are major contributors to osteoporosis development. This study aims to identify potential diagnostic markers and molecular targets for osteoporosis treatment from an immunological perspective. Method: We downloaded dataset GSE56116 from the Gene Expression Omnibus database, and identified differentially expressed genes (DEGs) between normal and osteoporosis groups. Subsequently, differentially expressed immune-related genes (DEIRGs) were identified, and a functional enrichment analysis was performed. A protein-protein interaction network was also constructed based on data from STRING database to identify hub genes. Following external validation using an additional dataset (GSE35959), effective biomarkers were confirmed using RT-qPCR and immunohistochemical (IHC) staining. ROC curves were constructed to validate the diagnostic values of the identified biomarkers. Finally, a ceRNA and a transcription factor network was constructed, and a Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis was performed to explore the biological functions of these diagnostic markers. Results: In total, 307 and 31 DEGs and DEIRGs were identified, respectively. The enrichment analysis revealed that the DEIRGs are mainly associated with Gene Ontology terms of positive regulation of MAPK cascade, granulocyte chemotaxis, and cytokine receptor. protein-protein interaction network analysis revealed 10 hub genes: FGF8, KL, CCL3, FGF4, IL9, FGF9, BMP7, IL17RA, IL12RB2, CD40LG. The expression level of IL17RA was also found to be significantly high. RT-qPCR and immunohistochemical results showed that the expression of IL17RA was significantly higher in osteoporosis patients compared to the normal group, as evidenced by the area under the curve Area Under Curve of 0.802. Then, we constructed NEAT1-hsa-miR-128-3p-IL17RA, and SNHG1-hsa-miR-128-3p-IL17RA ceRNA networks in addition to ERF-IL17RA, IRF8-IL17RA, POLR2A-IL17RA and ERG-IL17RA transcriptional networks. Finally, functional enrichment analysis revealed that IL17RA was involved in the development and progression of osteoporosis by regulating local immune and inflammatory processes in bone tissue. Conclusion: This study identifies the immune-related gene IL17RA as a diagnostic marker of osteoporosis from an immunological perspective, and provides insight into its biological function.

4.
Opt Lett ; 48(14): 3765-3768, 2023 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-37450745

RESUMEN

Recently, there has been a surge of interest in square-root higher-order topological insulators (HOTIs) due to their unique topological properties inherited from their squared Hamiltonian. Different from conventional HOTIs, square-root HOTIs support paired corner states that exist in different bandgaps. In this work, we experimentally establish a series of two-dimensional photonic decorated Su-Schrieffer-Heeger (SSH) lattices by using the femtosecond-laser writing technique and thereby directly observe paired topological corner states. Interestingly, the higher-order topological properties of such square-root HOTIs are inherited from the parent Hamiltonian, which contains the celebrated 2D SSH lattice. The dynamic evolution of square-root corner states indicates that they exist in different bandgaps. This work not only provides a new platform to study higher-order topology in optics, it also brings about new possibilities for future studies of other novel HOTIs.


Asunto(s)
Fotones , Escritura
5.
Phys Rev Lett ; 130(10): 103801, 2023 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-36962047

RESUMEN

Frequent observations to a quantum system modify its coherent evolution through the Zeno effect and Zeno dynamics. Generally, the measurement process destroys the evolution environment of the monitored system, making repeated observations remain a challenge. Here, using the quantum analogy experiments, we realize and engineer the Zeno effect and Zeno dynamics in optical waveguide arrays, where the optical modes correspond to distinct quantum states, and the temporal evolution is mapped into the spatial propagation. We propose a new, extensible experimental strategy for realizing an optical analog of stroboscopic measurements, which are performed by the build-in, on-demand segmented waveguide portions. The weak-to-strong stroboscopic measurements are realized, where the monitored system undergoes a transition from free evolution to optical Zeno freezing. Setting the measurements in the strong regime, the optical Zeno effect and optical Zeno dynamics are successfully generated, and their relationship is demonstrated in optics. We then propose a novel quantum Zeno slicing approach, which allows us to dynamically engineer the Hilbert space of the monitored system. This generic approach is verified by generating a series of Zeno subspaces with different measurement projectors, based on the quantum-optical analogy. The complexity of light dynamics is largely increased, providing full control of the propagation via steering Zeno dynamics. Our results pave the way for manipulation of quantum states by harnessing Zeno dynamics in integrated photonics.

6.
Spectrochim Acta A Mol Biomol Spectrosc ; 293: 122439, 2023 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-36773425

RESUMEN

In this study, terahertz time-domain spectroscopy (THz-TDS) was used to obtain the terahertz absorption spectra of three free anthraquinones (Chrysophanol, Emodin, Physcion) in the frequency range of 0.2-4.3 THz. The results show that terahertz spectroscopy is an effective detecting such compounds. Meanwhile, the theoretical spectrum using density functional theory calculations agrees well with the experimental spectrum. A modal decoupling method was used to identify each low-frequency vibrational mode and determine the average contribution of different atoms and groups. Modal decoupling provides a better understanding of molecules' mixed vibrational modes and enables quantifying the atoms' vibrational contributions. Results show that the substituent group facilitates the transition between the fundamental vibrational modes; subsequently, the substituent group shifts the vibrational centre of gravity of the three molecules and affects the vibrational contribution of hydrogen bonds. Furthermore, insignificant Emodin absorption is related to the nearly symmetrical structure formed by the substituents. The feasibility of terahertz analysis of differential molecular structures has also been confirmed.

7.
Sensors (Basel) ; 23(2)2023 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-36679372

RESUMEN

Tea polyphenols, amino acids, soluble sugars, and other ingredients in fresh tea leaves are the key parameters of tea quality. In this research, a tea leaf ingredient estimation sensor was developed based on a multi-channel spectral sensor. The experiment showed that the device could effectively acquire 700-1000 nm spectral data of tea tree leaves and could display the ingredients of leaf samples in real time through the visual interactive interface. The spectral data of Fuding white tea tree leaves acquired by the detection device were used to build an ingredient content prediction model based on the ridge regression model and random forest algorithm. As a result, the prediction model based on the random forest algorithm with better prediction performance was loaded into the ingredient detection device. Verification experiment showed that the root mean square error (RMSE) and determination coefficient (R2) in the prediction were, respectively, as follows: moisture content (1.61 and 0.35), free amino acid content (0.16 and 0.79), tea polyphenol content (1.35 and 0.28), sugar content (0.14 and 0.33), nitrogen content (1.15 and 0.91), and chlorophyll content (0.02 and 0.97). As a result, the device can predict some parameters with high accuracy (nitrogen, chlorophyll, free amino acid) but some of them with lower accuracy (moisture, polyphenol, sugar) based on the R2 values. The tea leaf ingredient estimation sensor could realize rapid non-destructive detection of key ingredients affecting tea quality, which is conducive to real-time monitoring of the current quality of tea leaves, evaluating the status during tea tree growth, and improving the quality of tea production. The application of this research will be helpful for the automatic management of tea plantations.


Asunto(s)
Clorofila , , Té/química , Clorofila/análisis , Aminoácidos/análisis , Hojas de la Planta/química , Polifenoles/análisis , Polifenoles/metabolismo , Nitrógeno/análisis , Azúcares/análisis
8.
Front Mol Biosci ; 10: 1296782, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38187091

RESUMEN

Objectives: This study aims to identify the key senescence genes and potential regulatory mechanisms that contribute to the etiology of intervertebral disc degeneration (IDD). Method: We analyzed GSE34095 and GSE70362 datasets, identifying key senescence-related differentially expressed genes (DEGs) in IDD using lasso regression. Risk scores classified patients into high- and low-risk groups. We compared pathways, functions, and immune infiltration between these groups. Diagnostic ability was assessed using ROC curves and a nomogram predicted IDD incidence. In single-cell dataset GSE165722, we evaluated expression of key senescence-related DEGs. Results: We identified 12 key senescence-related DEGs distinguishing high- and low-risk IDD patients. Enrichment analysis revealed cellular stress response, apoptotic signaling pathway, and protein kinase activation differences. Immune cell analysis showed elevated eosinophils in low-risk group and increased effector memory CD8 T, central memory CD4 T, myeloid-derived suppressor, natural killer, monocyte, Type 1 T helper, plasmacytoid dendritic, and natural killer T cells in high-risk group. A nomogram using AUC >0.75 genes (CXCL8, MAP4K4, MINK1, and TNIK) predicted IDD incidence with good diagnostic power. High senescence scores were observed in neutrophils. Conclusion: Our diagnostic model, based on key senescence-related DEGs and immune cell infiltration, offers new insights into IDD pathogenesis and immunotherapy strategies.

9.
Appl Opt ; 61(24): 7119-7124, 2022 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-36256329

RESUMEN

Devices employed for optical polarization conversion are widely used in the areas of optical focusing, optical imaging, and microscopy. To circumvent the problems of traditional optical polarization conversion devices, such as a narrow bandwidth, bulky size, and integration difficulties, a linear-radial polarization converter (LRPC) method based on optical metasurfaces is proposed. For a visible wavelength, i.e., λ=632.8nm, an all-dielectric half-wave plate and a LRPC with a size of 40λ (25.312 µm) are designed. The simulated results demonstrate that the LRPC creates a radially polarized wave from a linearly polarized wave in the wavelength range of 620-680 nm. In addition, a cylindrical vectorial wave with different polarizations can be generated via an adjustment of the polarization direction of the incident wave. These types of polarization converters have the important advantage of high transmittance, while also being ultra-thin and easy to integrate. They are expected to be suitable for miniaturized and integrated optical devices.

10.
Inorg Chem ; 61(41): 16248-16255, 2022 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-36179063

RESUMEN

Herein, we provide an efficient strategy for constructing three-dimensional (3D) energetic coordination polymers (ECPs), namely, metal-organic frameworks (EMOFs), avoiding solvent coordination without changing the organic ligands or metal nodes. Three ECPs with the same ligand and metal center, namely, two-dimensional (2D) layer ECP [Pb(HOBTT)(H2O)2]n (1), 3D solvent-free EMOFs [Pb(HOBTT)]n (2), and dense [Pb3(OBTT)2]n (3) (H3OBTT = 4,5-bis(1-hydroxytetrazol-5-yl)-2H-1,2,3-triazole), were rationally designed and synthesized via free protons. As expected, the theoretical density of 3 (4.080 g·cm-3) is greater than those of 2 (3.299 g·cm-3) and 1 (3.055 g·cm-3). Thermal stabilities indicate that their decomposition temperature exceeds 300 °C. Theoretical calculations show that the detonation performance of 3 is better than that of 1 and 2. The detonation performance of 1-3 was further proven by laser irradiation.

11.
Artículo en Inglés | MEDLINE | ID: mdl-35858108

RESUMEN

Fumonisin B1 (FB1) has the highest natural contamination rate among all fumonisin analogs and can inhibit food intake and weight gain of pigs. Under laboratory conditions, carboxylesterase FumDSB has a high FB1 degradation rate and excellent pH and thermal stability. The present study sought to estimate the effects of FumDSB on growing pigs from the perspective of a brain-intestinal axis. Twenty-four growing pigs of similar weight were divided into Control, FB1 (5 mg FB1/kg feed), and FumDSB (5 mg FB1/kg and 0.1% FumDSB in the feed) groups. After 42 days of feeding, hypothalamus and jejunum samples were collected for quantitative real-time fluorescence, western blotting, and immunohistochemistry. The results showed that FB1 consumption can destruct the tissue structure of hypothalamus and jejunum, affect the expression and distribution of several appetite-related neuropeptides and inflammatory cytokines, thereby inducing neuroinflammatory responses and affecting food intake and weight gain. However, these anorexia effects and inflammatory responses are alleviated when FumDSB is added to the feed. In short, FumDSB can alleviate the inflammatory response induced by FB1 in growing pigs.


Asunto(s)
Fumonisinas , Alimentación Animal/análisis , Animales , Fumonisinas/química , Porcinos , Aumento de Peso
12.
Opt Lett ; 47(11): 2883-2886, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35648955

RESUMEN

We report on the experimental observation of the topological Anderson phase in one-dimensional quasi-periodical waveguide arrays produced by femtosecond laser writing. The evanescently coupled waveguides are with alternating coupling constants, constructing photonic lattices analogous to the Su-Schrieffer-Heeger model. Dynamic tuning of the interdimer hopping amplitudes of the waveguide array generates the quasi-periodic disorder of the coupling constants for the model. As light propagates in the corresponding photonic waveguides, it exhibits different modes depending on the magnitude of the disorder. The topological Anderson phase is observed as the disorder is sufficiently strong, which corresponds to the zero-energy mode in its spectrum. The experimental results are consistent with the theoretical simulations, confirming the existence of the disorder-driven topological phase from a trivial band in the photonic lattice.

13.
Toxins (Basel) ; 13(12)2021 12 07.
Artículo en Inglés | MEDLINE | ID: mdl-34941712

RESUMEN

Fumonisin B1 (FB1) is the most common food-borne mycotoxin produced by the Fusarium species, posing a potential threat to human and animal health. Pigs are more sensitive to FB1 ingested from feed compared to other farmed livestock. Enzymatic degradation is an ideal detoxification method that has attracted much attention. This study aimed to explore the functional characteristics of the carboxylesterase FumDSB in growing pigs from the perspective of brain-gut regulation. A total of 24 growing pigs were divided into three groups. The control group was fed a basal diet, the FB1 group was supplemented with FB1 at 5 mg/kg feed, and the FumDSB group received added FumDSB based on the diet of the FB1 group. After 35 days of animal trials, samples from the hypothalamus and jejunum were analyzed through HE staining, qRT-PCR and immunohistochemistry. The results demonstrated that the ingestion of FB1 can reduce the feed intake and weight gain of growing pigs, indicating that several appetite-related brain-gut peptides (including NPY, PYY, ghrelin and obestatin, etc.) play important roles in the anorexia response induced by FB1. After adding FumDSB as detoxifying enzymes, however, the anorexia effects of FB1 were alleviated, and the expression and distribution of the corresponding brain-gut peptides exhibited a certain degree of regulation. In conclusion, the addition of FumDSB can reduce the anorexia effects of FB1 by regulating several brain-gut peptides in both the hypothalamus and the jejunum of growing pigs.


Asunto(s)
Carboxilesterasa/metabolismo , Fumonisinas/metabolismo , Fumonisinas/toxicidad , Crecimiento y Desarrollo/efectos de los fármacos , Hipotálamo/efectos de los fármacos , Yeyuno/efectos de los fármacos , Proteolisis/efectos de los fármacos , Porcinos/crecimiento & desarrollo , Animales , Hipotálamo/metabolismo , Yeyuno/metabolismo , Venenos/metabolismo , Venenos/toxicidad
14.
Aging (Albany NY) ; 13(19): 23284-23307, 2021 10 11.
Artículo en Inglés | MEDLINE | ID: mdl-34633991

RESUMEN

OBJECTIVES: This study aimed to identify specific diagnostic as well as predictive targets of primary myelofibrosis (PMF). METHODS: The gene expression profiles of GSE26049 were obtained from Gene Expression Omnibus (GEO) dataset, WGCNA was constructed to identify the most related module of PMF. Subsequently, Gene Ontology (GO), Kyoto Encyclopedia Genes and Genomes (KEGG), Gene Set Enrichment Analysis (GSEA) and Protein-Protein interaction (PPI) network were conducted to fully understand the detailed information of the interested green module. Machine learning, Principal component analysis (PCA), and expression pattern analysis including immunohistochemistry and immunofluorescence of genes and proteins were performed to validate the reliability of these hub genes. RESULTS: Green module was strongly correlated with PMF disease after WGCNA analysis. 20 genes in green module were identified as hub genes responsible for the progression of PMF. GO, KEGG revealed that these hub genes were primarily enriched in erythrocyte differentiation, transcription factor binding, hemoglobin complex, transcription factor complex and cell cycle, etc. Among them, EPB42, CALR, SLC4A1 and MPL had the most correlations with PMF. Machine learning, Principal component analysis (PCA), and expression pattern analysis proved the results in this study. CONCLUSIONS: EPB42, CALR, SLC4A1 and MPL were significantly highly expressed in PMF samples. These four genes may be considered as candidate prognostic biomarkers and potential therapeutic targets for early stage of PMF. The effects are worth expected whether in the diagnosis at early stage or as therapeutic target.


Asunto(s)
Biología Computacional/métodos , Mielofibrosis Primaria , Transcriptoma/genética , Biomarcadores , Bases de Datos Genéticas , Perfilación de la Expresión Génica , Humanos , Aprendizaje Automático , Mielofibrosis Primaria/genética , Mielofibrosis Primaria/metabolismo , Mapas de Interacción de Proteínas/genética
15.
Artículo en Inglés | MEDLINE | ID: mdl-34500088

RESUMEN

The main toxic effects of deoxynivalenol (DON) are the result of long-term accumulation, and there are no obvious clinical signs at the early stage. Specific metabolites in blood and urine can be used as biomarkers and become an important diagnostic indicator for DON poisoning monitoring. This study aimed to reveal the differences in DON-induced metabolites in the serum and urine of weaned rabbits. Thirty-two weaned rabbits were divided into two groups: control group and DON group. Both groups of rabbits were fed a basic diet. Rabbits in the DON group were administered 1.5 mg/kg b.w. DON by intraperitoneal injection on an empty stomach in the morning every two days. Rabbits in the control group were injected with the same amount of saline every two days in the same way. After the 25-day trial, serum and urine samples from different experimental periods were collected. The results based on the LC-MS/MS method showed that DON can be metabolized rapidly in blood, and urine is the main metabolic pathway for DON. Data based on metabolomics illustrated that underlying biomarkers in serum were mainly involved in glycerophospholipid metabolism, tryptophan metabolism and pentose and glucuronate interconversions, while those in urine samples were involved in caffeine metabolism, glycine, serine and threonine metabolism, and terpenoid backbone biosynthesis. Correlation analysis suggested that DON can induce changes in certain disease-related metabolites in serum and urine. In conclusion, the pathogenic mechanism of DON includes multiple levels, indicating that DON poisoning is caused by multiple factors acting on multiple links.


Asunto(s)
Conejos/sangre , Conejos/orina , Tricotecenos/farmacología , Animales , Biomarcadores/sangre , Biomarcadores/orina , Cromatografía Liquida , Dieta , Metaboloma , Espectrometría de Masas en Tándem , Destete
16.
Front Vet Sci ; 8: 632599, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33604367

RESUMEN

Deoxynivalenol (DON) can activate related signaling pathways and induce gastrointestinal disorders. Based on the results of previous studies, this study tried to explore the relationship between DON-induced intestinal inflammation of weaned rabbits and the ERK-p38 signaling pathway. Forty-five weaned rabbits were divided into three treatments: control, LD and HD group. All rabbits were treated with diet containing a same nutrient content, but animals in the LD and HD groups were additionally administered DON via drinking water at 0.5 and 1.5 mg/kg b.w./d, respectively. The protocol consisted of a total feeding period of 31 days, including a pre-feeding period of 7 days. Western blotting, qRT-PCR, and immunohistochemistry were applied for analysis the expression of protein and mRNA of extracellular signal-regulated kinase (ERK), p38, double-stranded RNA-activated protein kinase (PKR), and hematopoietic cell kinase (Hck) in the duodenum, jejunum, and ileum of rabbits, as well as the distribution of positive reactants. The results proved that DON intake could enhance the levels of inflammatory factors in serum and damage the intestinal structure barrier of rabbits. Meanwhile, DON addition can stimulate the protein and mRNA expression for ERK, p38, PKR, and Hck in the intestine of rabbits, especially in the duodenum, as well as expand the distribution of positive reactants, in a dose-dependent manner.

17.
J Hazard Mater ; 409: 124923, 2021 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-33482478

RESUMEN

Mercury (Hg) is one of the chemicals that bring serious adverse effects to the environment and human beings. Methylmercury (MeHg) is a neurotoxin while inorganic Hg (IHg) is not. Early screening of the neurotoxicity of chemicals may help reduce the occurrence of neurological disorders by minimizing chemical exposure. This work proposed the combined application of gut microbiome, metabolomics and metallomics to differentiate the neurotoxicity between MeHg and IHg in rats. It was found that MeHg caused down-regulated Bacteroides, Firmicutes and Proteobacteria, and up-regulated Actinobacteria and Verrucomicrobia at phylum level, while MeHg caused up-regulated Verrucomicrobiaceae, Desulfovibrionaceae, Helicobacteraceae, Lachnospiraceae and down-regulated Rikenellaceae, Erysipelotrichaceae, Sutterellaceae, Anaeroplasmataceae and Coriobacteriaceae in feces than IHg did at family level; Besides, MeHg brought metabolites change in activation of gut-brain axis pathway than IHg did, such as Glutamate, γ-aminobutyric acid (GABA), Dopamine (DA) and Tryptophan. These differences between MeHg and IHg were further confirmed by the distribution of Hg in the intestine, as well as the level of brain-derived neurotrophic factor (BDNF) in the intestine, brain and serum. Therefore, the difference of toxicity between MeHg and IHg can be well distinguished through feces after exposure for only 24 h, which may be used for the screening of neurotoxicity of other chemicals.


Asunto(s)
Microbioma Gastrointestinal , Mercurio , Compuestos de Metilmercurio , Animales , Heces , Mercurio/toxicidad , Metabolómica , Compuestos de Metilmercurio/toxicidad , Ratas
18.
Nano Today ; 36: 101037, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33250930

RESUMEN

The coronavirus disease 2019 (COVID-19) pandemic represents a severe global health threat. Selenium (Se), as one of the essential trace elements in human body, is well known for its antioxidant and immunity-boosting capabilities that induce a strong antiviral effect. In response to the global pandemic, we highlight here the current status of Se in combating different viruses, as well as the potential application of nano-selenium (nanoSe) in combating COVID-19.

19.
Ecotoxicol Environ Saf ; 208: 111460, 2021 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-33120263

RESUMEN

Mercury (Hg) is one of the most toxic heavy metals. It can migrate around the globe and magnify through the food chain, ultimately harming human health. Urinary Hg reflects recent exposure of Hg, which reflects the status of environmental contamination by Hg. This review summarized the levels and presented temporal trends of urinary Hg in Chinese people (both the general public and the occupationally exposed people) reported from 1970s to 2010s. It was found that urinary Hg levels in 92.3% of the reported population were less than the reference value (10.0 µg/L) recommended by Chinese health authority, while 76.9% were less than the reference value (4.0 µg/L) recommended by World Health Organization (WHO) in the general public in China. For the temporal trend from 1970s to 2010s, the urinary Hg levels in the general public in China were found to decrease gradually. In the occupationally exposed people, the urinary Hg levels generally exceeded the reference value (10.0 µg/L) for the general public, and about half of them were higher than the occupational exposure limit (35.0 µg/g creatinine) set by Chinese Occupational Health Standard (WS/T 265 - 2006). From 1970s to 2010s, the urinary Hg levels in occupationally exposed population increased first and then decreased slowly. Hg miners in Guizhou were found to have the highest urinary Hg levels, while workers in Anhui, Chongqing, Qinghai and Shanxi also had high levels of urinary Hg. In all, the urinary Hg levels in both the general public and the occupationally exposed people decreased from 1970s to 2010s, especially in recent decades. Attention should be paid to occupationally exposed people since high levels of urinary Hg were found in them. The message provided in this review can help better understand the situation of Hg burden in Chinese people and lay a basis for the coming effectiveness evaluation on the implementation of Minamata Convention on Mercury. Capsule abstract: The urinary Hg levels in both the general public and the occupationally exposed people in China are decreasing.


Asunto(s)
Exposición a Riesgos Ambientales/estadística & datos numéricos , Contaminantes Ambientales/orina , Mercurio/orina , Adulto , Pueblo Asiatico , China , Humanos , Mercurio/análisis , Exposición Profesional/análisis , Valores de Referencia
20.
Anal Methods ; 12(47): 5684-5690, 2020 12 21.
Artículo en Inglés | MEDLINE | ID: mdl-33201938

RESUMEN

Due to the instability of α type HMX at low concentrations, it belongs to the impurity crystal form. To ensure the functional effectiveness, operational reliability and management safety of HMX, it is necessary to quantify the low content of the unstable α-HMX crystal form in the composite explosive. In this study, low-concentration α-HMX is quantitatively analyzed in a mixture of α- and ß-HMX. First, terahertz time-domain spectroscopy (THz-TDS) is used to obtain the absorption spectrum of the α/ß-HMX element in the frequency range of 0.2-2.0 THz, and the characteristic frequency is selected. The absorption coefficient data in the frequency band of 0.7-1.3 THz are considered as the sample data for quantitative analysis. Finally, support vector machine (SVM) algorithm is used to establish a regression model, and principal component analysis (PCA) is employed for feature extraction. Grid search (GS), genetic algorithm (GA) and particle swarm optimization (PSO) are utilized for parameter optimization in support vector regression (SVR). These algorithms are combined to establish six regression models, and their effectiveness is assessed. The experimental results show that all the six methods can predict the content of α-HMX components with a small error and a high prediction accuracy. Compared to GA-SVR and PSO-SVR models, the PCA-GA-SVR and PCA-PSO-SVR models exhibit higher prediction accuracy and stability. The test set of the PCA-GA-SVR model reveals an average absolute error of 0.880%. It has the highest prediction accuracy, and the coefficient of determination (R2) reaches 0.9996. This indicates that PCA and SVR can be effectively used in the detection of low-concentration HMX components and can serve as a reliable basis for the quantitative analysis of other explosives.

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