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1.
Opt Express ; 32(7): 12092-12103, 2024 Mar 25.
Article in English | MEDLINE | ID: mdl-38571042

ABSTRACT

To achieve an autonomously controlled reconfigurable microwave waveform generator, this study proposes and demonstrates a self-adjusting synthesis method based on a photonic delay reservoir computer with ring resonator. The proposed design exploits the ring resonator to configure the reservoir, facilitating a nonlinear transformation and providing delay space. A theoretical analysis is conducted to explain how this configuration addresses the challenges of microwave waveform generation. Considering the generalization performance of waveform generation, the simulations demonstrate the system's capability to produce six distinct representative waveforms, all exhibiting a highly impressive root mean square error (RMSE) of less than 1%. To further optimize the system's flexibility and accuracy, we explore the application of various artificial intelligence algorithms at the reservoir computer's output layer. Furthermore, our investigation delves deeply into the complexities of system performance, specifically exploring the influence of reservoir neurons and micro-ring resonator parameters on calculation performance. We also delve into the scalability of reservoirs, considering both parallel and cascaded arrangements.

2.
Psicothema ; 36(1): 1-14, 2024.
Article in English | MEDLINE | ID: mdl-38227295

ABSTRACT

BACKGROUND: Applying a three-level meta-analysis, the goal of our investigation was to examine the relationship between parental homework involvement and students' achievement, and to investigate whether certain study features could have resulted in the inconsistent results relating to this relationship from prior studies. METHOD: We identified a total of 28 studies (32 independent samples) with 252 effect sizes for a total of 378222 participants. RESULTS: Our meta-analysis revealed an overall weak negative relationship between parental homework involvement and students' achievement ( r = −0.064, p < 0.001). The overall relationship was moderated by the dimension of parental homework involvement. Specifically, students' achievement was positively related to autonomy support, but largely unrelated to content support, parental control, frequency, and mixed. Additionally, the overall relationship was moderated by achievement measure, grade level, and parent gender. CONCLUSIONS: Given that parental autonomy support was the only dimension that was positively related to students' achievement, it would be important to conduct qualitative research that provides longitudinal descriptions of parent-child interactions relating to homework tasks as children make their transition from elementary to middle and high school.


Subject(s)
Academic Success , Humans , Schools , Parent-Child Relations , Parents , Students
3.
J Am Chem Soc ; 146(2): 1635-1643, 2024 Jan 17.
Article in English | MEDLINE | ID: mdl-38182551

ABSTRACT

Creating a perfect catalyst to operate enzyme-like chiral recognition has been a long-sought aim. A challenging example in this context is constructing acyclic all-carbon quaternary stereogenic centers by transition metal-catalyzed enantioselective C-H activation. We now report highly enantioselective iridium-catalyzed primary C-H borylation of α-all-carbon substituted 2,2-dimethyl amides enabled by a tailor-made chiral bidentate boryl ligand (CBL). The success of the current transformation is attributed to the CBL/iridium catalyst, which has a confined chiral pocket. This protocol provides a diverse array of acyclic all-carbon quaternary stereocenters with excellent enantiocontrol and distinct structural features. Computational study reveals that steric hindrance of CBL could regulate the type of dominant orbital interaction between the catalyst and substrate, which is crucial to conferring high chiral induction.

4.
Psicothema (Oviedo) ; 36(1): 1-14, 2024. ilus, tab, graf
Article in English | IBECS | ID: ibc-229717

ABSTRACT

Background: Applying a three-level meta-analysis, the goal of our investigation was to examine the relationship between parental homework involvement and students’ achievement, and to investigate whether certain study features could have resulted in the inconsistent results relating to this relationship from prior studies. Method: We identified a total of 28 studies (32 independent samples) with 252 effect sizes for a total of 378222 participants. Results: Our meta-analysis revealed an overall weak negative relationship between parental homework involvement and students’ achievement (r = −0.064, p < 0.001). The overall relationship was moderated by the dimension of parental homework involvement. Specifically, students’ achievement was positively related to autonomy support, but largely unrelated to content support, parental control, frequency, and mixed. Additionally, the overall relationship was moderated by achievement measure, grade level, and parent gender. Conclusions: Given that parental autonomy support was the only dimension that was positively related to students’ achievement, it would be important to conduct qualitative research that provides longitudinal descriptions of parent-child interactions relating to homework tasks as children make their transition from elementary to middle and high school.(AU)


Antecedentes: Mediante un meta-análisis de tres niveles, el objetivo de esta investigación fue examinar la relación entre la participación de los padres en los deberes escolares y el rendimiento académico de los estudiantes, así como estudiar el rol mediador en esta relación de ciertas variables que podrían haber estado relacionadas con algunos resultados inconsistentes en estudios primarios. Método: Se identificaron 28 estudios, con 252 tamaños del efecto, para un total de 378222 participantes. Resultados: Los resultados revelaron una débil relación negativa entre la implicación de los padres en los deberes y el rendimiento de los estudiantes (r = −0,064, p < 0,001). Esta relación fue moderada por el tipo de implicación parental. Específicamente, el rendimiento de los estudiantes se relacionó positivamente con el apoyo a la autonomía, pero no con el apoyo al contenido, el control de los padres, la frecuencia y la combinación de estas dimensiones. Además, dicha relación fue moderada por la medida de rendimiento, el curso de los estudiantes y el género de los padres. Conclusiones: Es necesaria más investigación cualitativa sobre lo que ocurre en torno a las interacciones entre padres e hijos a la hora de la realización de los deberes escolares.(AU)


Subject(s)
Humans , Male , Female , Child , Adolescent , Parenting , Academic Performance , Students/psychology , Psychology
5.
Infect Med (Beijing) ; 2(3): 212-223, 2023 Sep.
Article in English | MEDLINE | ID: mdl-38073882

ABSTRACT

Background: West Nile virus is a severe zoonotic pathogen that can cause severe central nervous system symptoms in humans and horses, and is fatal for birds, chickens and other poultry. With no specific drugs or vaccines available, antibody-based therapy is a promising treatment. This study aims to develop neutralizing antibodies against West Nile virus and assess their cross-protective potential against Japanese encephalitis virus. Methods: Monoclonal antibodies against WNV and JEV were isolated by hybridoma technology. The therapeutic efficacy of these antibodies was evaluated using a mouse model, and a humanized version of the monoclonal antibody was generated for potential human application. Results: In this study, we generated eight monoclonal antibodies that exhibit neutralizing activity against WNV. Their therapeutic effects against WNV were validated both in vivo and in vitro. Among these antibodies, C9-G11-F3 also exhibited cross-protective activity against JEV. We also humanized the antibody to ensure that it could be used for WNV infection treatment in humans. Conclusion: This study highlights the importance of neutralizing antibodies as a promising approach for protection against West Nile virus infection and suggests their potential utility in the development of therapeutic interventions.

6.
Opt Express ; 31(1): 211-226, 2023 Jan 02.
Article in English | MEDLINE | ID: mdl-36606961

ABSTRACT

We report on a quantitative quasi-distributed vibration sensing (DVS) system enabled by phase-sensitive optical frequency domain reflectometry (φ-OFDR), which allows for multiple vibration events over consecutive spatial resolutions. To achieve effective crosstalk suppression and mitigation of the instability during the phase extraction, fiber with embedded ultra-weak grating arrays has been adopted as the sensing fiber. It exhibits a particularly customized low spatial duty cycle, that is, high ratio between the size of the gratings and their spacing and the spacing is additionally designed to match the integer multiple of the theoretical spatial resolution. In combination with a rectified frequency-modulated continuous-wave optical probe enabled by the optical phase-locked loop, it allows to achieve quantitative quasi-DVS for multiple events over consecutive sensing spatial resolution as high as ∼2.5 cm along the distance over ∼2200 m. The ability to simultaneously retrieve arbitrary multi-point vibration events over spatially consecutive sensing spatial resolutions with consistently linear response and sensitivity up to a few nano-strain level even at long distances has shown great potentials for the application of φ-OFDR from a practical point of view.

7.
J Ethnopharmacol ; 298: 115643, 2022 Nov 15.
Article in English | MEDLINE | ID: mdl-36031105

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: The Jieduquyuziyin prescription (JP), a traditional Chinese medicine (TCM) formula, has been used as an approved hospital prescription to improve the efficacy of prednisone (Pred) in systemic lupus erythematosus (SLE) and lupus nephritis (LN) treatment. Although the synergistic effect of JP and Pred is prominent, the underlying mechanisms require further investigation. AIM OF THE STUDY: To explore the key therapeutic targets of JP in improving the role of Pred in the treatment of LN. MATERIALS AND METHODS: Lupus-prone female MRL/lpr mice were administered JP, Pred, or JP combined with Pred. The effect of JP on LN was estimated by evaluating renal function and inflammation levels in the kidneys. On this basis, RNA sequencing of kidney tissues was performed, and the differentially expressed genes were analyzed and summarized. The role of JP in the expression of nuclear factor erythroid 2-related factor 2 (NFE2L2 or Nrf2) in the kidneys was further confirmed by real-time PCR, immunohistochemistry, and western blotting. RESULTS: JP combined with Pred exhibited the most remarkable therapeutic effect compared with JP or Pred alone. Transcriptome analysis indicated that Nrf2, a central mediator of the antioxidative response, was significantly upregulated by JP. Based on these results, we speculated that Nrf2 is a critical factor for JP, improving the efficacy of Pred in treating LN by notably suppressing the oxidative stress level in the kidneys. Furthermore, we found that Nrf2 expression decreased with the exacerbation of LN in MRL/lpr mice. In addition, the downregulated Nrf2 was notably restored after JP treatment, accompanied by suppressed oxidative stress levels in the kidneys. It includes inhibited accumulation of reactive oxygen species (ROS) and malondialdehyde (MDA), restored mitochondrial membrane potential (MMP) levels, and increased antioxidant enzyme activity of superoxide dismutase (SOD). CONCLUSIONS: Our findings show that JP increases Pred efficacy by increasing Nrf2 expression, implying that Nrf2 may be a promising therapeutic target for the treatment of LN.


Subject(s)
Lupus Nephritis , Animals , Drugs, Chinese Herbal , Female , Kidney/metabolism , Lupus Nephritis/drug therapy , Lupus Nephritis/metabolism , Mice , Mice, Inbred MRL lpr , Prednisone/pharmacology , Prednisone/therapeutic use , Prescriptions
8.
Opt Express ; 30(9): 14886-14896, 2022 Apr 25.
Article in English | MEDLINE | ID: mdl-35473222

ABSTRACT

We report on an enhanced photonic generation of frequency-modulated continuous-wave (FMCW) signals by injection-locking a semiconductor laser operating in period-one (P1) nonlinear dynamic with an intensity modulated electro-optic frequency comb. When the cavity mode is injection-locked with respect to any of the comb modes, through linearly sweeping the frequency of the injected comb mode while synchronously modulating the injected intensity, the center wavelength of the cavity mode can be tuned following the injected comb mode. This way, it allows maintaining the phase-locking between the cavity mode and comb mode even if beyond the original locking bandwidth of the cavity mode, since it is tuned accordingly. It thus leads to the generation of FMCW signal with efficient phase noise suppression and improved achievable sweep range compared with the limited original injection-locking bandwidth. Such injection enhanced phase-locking is investigated and a demonstration with the injection of -4th order comb mode has realized photonic FMCW generation with enhanced sweep range and suppressed phase noise. Thanks to the flexibility in sweep parameters, this method can also be readily applied for the generation of arbitrary waveforms.

9.
Opt Express ; 30(2): 1994-2005, 2022 Jan 17.
Article in English | MEDLINE | ID: mdl-35209349

ABSTRACT

We present and establish a versatile analytical model that allows overall analysis and optimization for the phase noise performance of the delay interferometer based optical phase-locked loop (OPLL). It allows considering any type of lasers with arbitrary frequency noise properties while taking into account the contributions from various practical noise sources, thus enabling comprehensive investigation for the complicated interaction among underlying limiting factors. The quantitative analysis for their evolution along with the change of the delay of the interferometer unveils the resulting impact on the fundamental limit and dynamics of the output phase noise, leading to a well-balanced loop bandwidth and sensitivity thus enabling the overall optimization in terms of closed-loop noise performance. The tendencies observed and the results predicted in terms of coherence metrics in numerical verification with different lasers have testified to the precision and effectiveness of the proposed model, which is quite capable of acting as a design tool for the insightful analysis and overall optimization with guiding significance for practical applications.

10.
Acta Pharmacol Sin ; 43(6): 1521-1533, 2022 Jun.
Article in English | MEDLINE | ID: mdl-34552214

ABSTRACT

Systemic lupus erythematosus (SLE) is a devastating autoimmune disorder associated with severe organ damage. The abnormality of T cell apoptosis is considered as an important pathogenetic mechanism of SLE. Norcantharidin (NCTD), a derivative of Cantharidin, is an efficacious anti-cancer drug by inhibiting cell proliferation and inducing cell apoptosis. Besides, NCTD has also been proved to protect the function of kidneys, while damaged renal function is the most important predictor of morbidity and mortality in SLE. All these suggest the potential effects of NCTD in SLE treatment. In this study we investigated whether NCTD exerted therapeutic effects in a mouse SLE model. Lupus prone female MRL/lpr mice were treated with NCTD (1, 2 mg·kg-1·d-1, ip) for 8 weeks. We showed that NCTD administration significantly decreased mortality rate, diminished the expression of anti-dsDNA IgG antibody, a diagnostic marker for SLE, as well as restored renal structure and function in MRL/lpr mice. Moreover, NCTD administration dose-dependently inhibited lymphoproliferation and T cell accumulation in the spleens of MRL/lpr mice. We further revealed that NCTD specifically inhibited DN T cell proliferation and Th17 cell differentiation both via blocking activation of signal transducer and activator of transcription 3 (STAT3) signaling pathway. On the other hand, NCTD did not affect T cell apoptosis in MRL/lpr mice. Taken together, our data suggest that NCTD may be as a promising therapeutic drug through targeting T cells for the treatment of SLE.


Subject(s)
Interleukin-17 , Lupus Erythematosus, Systemic , Animals , Bridged Bicyclo Compounds, Heterocyclic , Disease Models, Animal , Female , Lupus Erythematosus, Systemic/drug therapy , Lupus Erythematosus, Systemic/pathology , Mice , Mice, Inbred MRL lpr , Th17 Cells
11.
Chem Sci ; 12(12): 4353-4360, 2021 Jan 26.
Article in English | MEDLINE | ID: mdl-34163698

ABSTRACT

A new strategy of asymmetric carbonyl catalysis via a chiral Lewis acid-bonded aldehyde has been developed for the direct Mannich/condensation cascade reaction of glycine ester with aromatic aldimines. The co-catalytic system of 2-picolinaldehyde and chiral YbIII-N,N'-dioxides was identified to be efficient under mild conditions, providing a series of trisubstituted imidazolidines in moderate to good yields with high diastereo- and enantioselectivities. Enantiodivergent synthesis was achieved via changing the sub-structures of the chiral ligands. The reaction could be carried out in a three-component version involving glycine ester, aldehydes, and anilines with equally good results. Based on control experiments, the X-ray crystal structure study and theoretical calculations, a possible dual-activation mechanism and stereo-control modes were provided to elucidate carbonyl catalysis and enantiodivergence.

12.
Opt Lett ; 46(9): 2103-2106, 2021 May 01.
Article in English | MEDLINE | ID: mdl-33929429

ABSTRACT

We present a dual-frequency laser Doppler velocimeter (DF-LDV) relying on a DF laser source (DFLS) generated by optical phase-locking two individual lasers to a common unbalanced Mach-Zehnder interferometer, which allows achieving high stability regardless of the DF separation of the lasers. This DFLS is evaluated using an optical frequency comb, testifying to the generation of DFLS with large DF separation up to terahertz with flexible tunability and high stability. Demonstration of DF-LDV using the DFLS of ${\sim}1.024\; {\rm THz}$ separation has achieved $1.62 \times {10^{- 2}}$ mm/s velocity resolution even for a slow velocity of $1.8\; {\rm mm}/{\rm s}$ in a mere 5 s acquisition time, confirming the high resolution and efficient speckle noise suppression enabled by the proposed DF-LDV. Featuring high precision, flexibility, and robustness, this method is particularly attractive from the practical point of view.

13.
Opt Express ; 29(2): 604-614, 2021 Jan 18.
Article in English | MEDLINE | ID: mdl-33726293

ABSTRACT

We report on the generation of a highly coherent broadband optical linear frequency sweep (LFS) using mode-spacing swept comb and multi-loop composite optical phase-locked loop (OPLL). We exploit a specially designed agile opto-electronic frequency comb as a sweeping reference, whose mode-spacing is capable of arbitrary frequency sweep while preserving a stable phase and power distribution per mode. By locking a continuous-wave (CW) laser to any of its modes using composite OPLL with a large loop bandwidth, it allows the extraction of the optical LFS at high-order modes in a coherent manner with a multiplied sweep range and rate. With such capability, only intermediate frequency LFS with smaller bandwidth is required to yield a broadband LFS while inheriting the coherence and precision from the comb. We achieve optical LFS of 60 GHz at 6 THz/s sweep rate with a nine-folded sweep bandwidth of the driving signal. Fourier transform-limited spatial resolution at more than 80 times of the intrinsic coherence length of the CW laser is demonstrated in an OFMCW interferometry, verifying the high coherence with more than 4 orders of magnitude improvement in spatial resolution. The characteristics in terms of agility, coherence, and precision are discussed together with the potential limitations. The proposed method is capable of generating arbitrary frequency-modulated optical waveforms with a multiplied bandwidth, showing attractive potential in future metrology applications.

14.
Sensors (Basel) ; 21(4)2021 Feb 23.
Article in English | MEDLINE | ID: mdl-33672175

ABSTRACT

The development of information technology has brought great convenience to our lives, but at the same time, the unfairness and privacy issues brought about by traditional centralized systems cannot be ignored. Blockchain is a peer-to-peer and decentralized ledger technology that has the characteristics of transparency, consistency, traceability and fairness, but it reveals private information in some scenarios. Secure multi-party computation (MPC) guarantees enhanced privacy and correctness, so many researchers have been trying to combine secure MPC with blockchain to deal with privacy and trust issues. In this paper, we used homomorphic encryption, secret sharing and zero-knowledge proofs to construct a publicly verifiable secure MPC protocol consisting of two parts-an on-chain computation phase and an off-chain preprocessing phase-and we integrated the protocol as part of the chaincode in Hyperledger Fabric to protect the privacy of transaction data. Experiments showed that our solution performed well on a permissioned blockchain. Most of the time taken to complete the protocol was spent on communication, so the performance has a great deal of room to grow.

15.
Front Pharmacol ; 11: 583171, 2020.
Article in English | MEDLINE | ID: mdl-33123015

ABSTRACT

Rheumatoid arthritis (RA) is an autoimmune disease mainly characterized by chronic polyarthritis. Many types of cells play pivotal roles in the pathogenicity of RA, such as T cells, B cells, macrophages, dendritic cells (DCs), osteoclasts (OCs), and fibroblast-like synoviocytes (FLS). Tripterygium wilfordii Hook f. (TwHf) and its ingredients are able to control disease activity by regulating the functions of cells mentioned above, and the clinical studies have highlighted the importance of TwHf ingredients in RA treatment. They have been demonstrated to improve the RA symptoms of animal models and patients. In this review, we discussed the effect of TwHf ingredients on pathogenicity cells, including disease/cell phenotypes and molecular mechanisms. Here, we constructed a cell-cell interaction network to visualize the effect of TwHf ingredients. We found that TwHf ingredients could inhibit the differentiation and proliferation of the pathogenicity cells. Besides, the components could decrease the levels of pathogenicity cytokines [i.e., interleukin-6 (IL-6), interleukin-1ß (IL-1ß), and tumor necrosis factor-α (TNF-α)]. Many signaling pathways are involved in the underlying mechanisms, such as PI3K, NF-κB, and MAPK signaling pathways.

16.
Anal Chim Acta ; 1087: 113-120, 2019 Dec 09.
Article in English | MEDLINE | ID: mdl-31585559

ABSTRACT

A highly sensitive fluorescence turn-off biosensor for the detection of ochratoxin A (OTA) was developed based on graphene oxide (GO) and an aptamer-induced detachable nanoladders. In this assay, two types of ssDNA (H1 and H2) were involved in the assembly of the DNA nanoladders, in which H1 was labeled with fluorophore, and H2 was the OTA binding aptamer. Self-assembly of the DNA nanoladders with the addition of GO weakened its adsorption and the fluorescence intensity remained strong. In the presence of OTA, the aptamer was specifically recognized and an aptamer-OTA complex was formed, leading to the detached of DNA nanoladders. With the addition of GO, the released H1 was adsorbed on the GO surface, thus efficiently quenching the fluorescence signal (turning off). The detection limit of OTA in this assay was 4.59 nM. To improve the sensitivity of this strategy, we creatively developed an alternative strategy to replace the sturdy nanoladders with frail nanoladders. More precisely, the sequences of H1 had mismatched bases, which, when hybridized with H2 could be used to create long non-perfect complementary nanoladders. For the mismatched bases-based frail nanoladders, it was easier for OTA to bind its aptamer sequence, thus enabling a more thorough and faster detachment of the nanoladders, along with a greater degree of fluorescence quenching. The detection limit for OTA was estimated to be 0.1 nM. The biosensors we developed were sensitive, specific, enzyme-free, cost-effective and can be applied in red wine samples spiked with known concentration of OTA.


Subject(s)
Aptamers, Nucleotide/chemistry , DNA, Single-Stranded/chemistry , Food Contamination/analysis , Graphite/chemistry , Nanostructures/chemistry , Ochratoxins/analysis , Biosensing Techniques/methods , DNA, Single-Stranded/genetics , Fluorescent Dyes/chemistry , Limit of Detection , Nucleic Acid Hybridization , Spectrometry, Fluorescence/methods , Wine/analysis
17.
Chem Commun (Camb) ; 55(30): 4436, 2019 04 09.
Article in English | MEDLINE | ID: mdl-30933199

ABSTRACT

Correction for 'Mercury nanoladders: a new method for DNA amplification, signal identification and their application in the detection of Hg(ii) ions' by Yuxiang Feng et al., Chem. Commun., 2018, 54, 8036-8039.

18.
Mikrochim Acta ; 186(2): 111, 2019 01 14.
Article in English | MEDLINE | ID: mdl-30637507

ABSTRACT

A rapid method for identification and typing of lipopolysaccharides (LPS) was developed by utilizing the different binding affinities between two kinds of gold nanoparticles (AuNPs) functionalized with two aptamers. Aptamers against ethanolamine and E. coli O111:B4 LPS were used to functionalize the AuNPs. The AuNPs functionalized with ethanolamine aptamer can bind to ethanolamine and are termed general probe (G-probe). The G-probe can recognize any type of LPS because ethanolamine is a component of every type of LPS. This causes a sandwich-mediated aggregation of the AuNPs and a color change from red to blue. The AuNPs functionalized with aptamer against the LPS of E. coli O111:B4 specifically bind to O111:B4 LPS and are termed specific probe (S-probe). By using these two probes, a logic typing method was developed. It can detect LPS in concentrations between 2.5 and 20 µg·mL-1 and with a 1 µg·mL-1 detection limit. In the authors' perception, the use of a dual aptamer-based colorimetric method has a large potential in terms of selective detection of microorganisms. Graphical abstract Two aptamer functionalized AuNP probes, G-probe and S-probe, were prepared for LPS typing and detecting. E. coli O111:B4 LPS was easily distinguished from O55:B5 LPS according to the signal output configurations (On & On Vs On & Off) of a general probe (G-probe) and a specific probe (S-probe).


Subject(s)
Aptamers, Nucleotide/chemistry , Aptamers, Nucleotide/metabolism , Colorimetry/methods , Escherichia coli , Gold/chemistry , Lipopolysaccharides/analysis , Metal Nanoparticles/chemistry , Aptamers, Nucleotide/genetics , Base Sequence , Buffers , Ethanolamine/chemistry , Limit of Detection , Lipopolysaccharides/metabolism
19.
Chem Commun (Camb) ; 54(58): 8036-8039, 2018 Jul 17.
Article in English | MEDLINE | ID: mdl-29926051

ABSTRACT

A biosensor based on Hg(ii) nanoladders integrated with graphene oxide (GO) for Hg(ii) detection was developed. Nanoladders were essentially DNA sandwich structures supported by T-Hg(ii)-T and were used for Hg(ii) trapping and signal translation. GO was used to differentiate the fluorescence generated by Hg(ii) nanoladders from a background signal.


Subject(s)
Biosensing Techniques/methods , DNA/chemistry , Mercury/analysis , Nanostructures/chemistry , Nucleic Acid Amplification Techniques/methods , Fluorescence , Graphite/chemistry , Limit of Detection , Mercury/chemistry , Oxides/chemistry
20.
Molecules ; 23(2)2018 Jan 30.
Article in English | MEDLINE | ID: mdl-29385683

ABSTRACT

The objectives of the present study were to characterize the chemical composition, antioxidant activity and hepatoprotective effect of the polysaccharides from Taishan Pinus massoniana pollen (TPPPS). HPLC analysis showed that TPPPS was an acidic heteropolysaccharide with glucose and arabinose as the main component monosaccharides (79.6%, molar percentage). Fourier transform-infrared spectroscopy (FT-IR) analysis indicated that the spectra of TPPPS displayed infrared absorption peaks characteristic of polysaccharides. In in vitro assays TPPPS exhibited different degrees of dose-dependent antioxidant activities , and this was further verified by suppression of CCl4-induced oxidative stress in the liver with three tested doses of TPPPS (100, 200, and 400 mg/kg bw) in rats. Pretreatment with TPPPS significantly decreased the levels of alanine aminotransferase (AST), aspartate aminotransferase (ALT), alkaline phosphatase (ALP), lactic dehydrogenase (LDH) and malondialdehyde (MDA) against CCl4 injuries, and elevated the activities of superoxide dismutase (SOD) as well as glutathione peroxidase (GSH-Px). Histopathological observation further confirmed that TPPPS could protect the liver tissues from CCl4-induced histological alternation. These results suggest that TPPPS has strong antioxidant activities and significant protective effect against acute hepatotoxicity induced by CCl4. The hepatoprotective effect may partly be related to its free radical scavenging effect, increasing antioxidant activity and inhibiting lipid peroxidation.


Subject(s)
Antioxidants , Carbon Tetrachloride Poisoning/prevention & control , Liver/metabolism , Pinus/chemistry , Pollen/chemistry , Polysaccharides , Animals , Antioxidants/chemistry , Antioxidants/pharmacology , Carbon Tetrachloride Poisoning/metabolism , Carbon Tetrachloride Poisoning/pathology , Dose-Response Relationship, Drug , Liver/pathology , Male , Polysaccharides/chemistry , Polysaccharides/pharmacology , Rats , Rats, Wistar
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