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1.
Appl Opt ; 59(3): 607-613, 2020 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-32225184

RESUMO

We present a dual-channel mobile lidar system based on laser-induced fluorescence (LIF) for real-time standoff detection and concentration distribution analysis of tryptophan. The system employs an ultraviolet laser excitation source and signal detectors for receiving fluorescence signals within two different wavelength bands. The performed experiments measured tryptophan aerosols at two different standoff distances. Moreover, distilled water and ethanol solutions were also detected for comparison. The results show that the system can detect LIF signals of tryptophan, give early warnings, locate the diffusion sources, and monitor the variation of the aerosol concentration distribution in real time.

2.
Sci Adv ; 6(8): eaay5154, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32128407

RESUMO

By hijacking endogenous E3 ligase to degrade protein targets via the ubiquitin-proteasome system, PROTACs (PRoteolysis TArgeting Chimeras) provide a new strategy to inhibit protein targets that were regarded as undruggable before. However, the catalytic nature of PROTAC potentially leads to uncontrolled degradation that causes systemic toxicity issues, limiting the application of PROTAC in the clinic. Here, we introduce a light-inducible switch on PROTACs, thereafter termed as opto-PROTAC, to enable the degradation of protein targets in a spatiotemporal manner. By adding a photolabile caging group on pomalidomide as a parental compound and two additional PROTACs, dBET1 and dALK, we demonstrated light-inducible protein degradation. These opto-PROTACs display no activities in the dark, while the restricted degradation can be induced at a specific time and rate by ultraviolet A irradiation. Our approach provides a generalizable platform for the development of light-controlled PROTACs and enables PROTAC to be a precision medicine.

3.
Clin Rheumatol ; 2020 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-32144624

RESUMO

OBJECTIVE: To analyze the clinical features and outcomes of the patients with anti-glycyl tRNA synthetase (anti-EJ) syndrome in a large Chinese cohort. METHODS: The medical records, imaging, and serologic data of patients with anti-EJ antibodies from the China-Japan Friendship Hospital database were retrospectively investigated. Anti-EJ antibodies were identified using immunoblot assay. Long-term follow-up was conducted. RESULTS: Anti-EJ antibodies were present in 46 (19.7%) of the 234 patients with antisynthetase syndrome (ASS), preceded by anti-Jo-1 and anti-PL-7 antibodies. The mean age of disease onset was 51.2 ± 15.9 years, and 69.6% of these patients were female. The most prevalent clinical feature was interstitial lung disease (ILD) (96.7%), which was also the most common initial manifestation, followed by fever (60.9%), mechanic's hands (56.5%), muscle involvement (50%), and Raynaud phenomenon (8.7%). Ten (21.7%) patients developed rapidly progressive ILD (RP-ILD). Organizing pneumonia (OP) on high-resolution computed tomography (HRCT) scans (OR = 37.5, p = 0.006) and a higher C-reactive protein-to-albumin ratio (CAR) (OR = 28.3, p = 0.01) were independent risk factors for RP-ILD. Muscular pathological features were heterogeneous. Concomitant infection was noted in 63.0% of the patients during the disease course. Hypoalbuminemia (OR = 0.759, p = 0.002) was an independent risk factor for concomitant infection. Patients responded well to glucocorticoid therapy. The 5- and 10-year survival rates of the patients with anti-EJ were 97.8% and 88%, respectively. CONCLUSION: Anti-EJ syndrome was found to be a relatively common ASS subtype, with a favorable outcome. A notable proportion of the patients experienced RP-ILD, which was prone to OP on HRCT and a higher CAR, and needed aggressive management.Key Points• ILD was the most common initial manifestation of anti-glycyl tRNA synthetase syndrome.• RP-ILD was notable in anti-EJ positive patients.• Anti-EJ positive patients possessed a favorable long-term prognosis, but easily relapsed.

4.
Pathol Res Pract ; : 152910, 2020 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-32139257

RESUMO

PURPOSE: Protein phosphatase 4 catalytic subunit (PP4C) has been shown to play crucial regulatory roles in biological process and is frequently upregulated in cancer such as breast and colorectal carcinoma. However, the function and potential molecular mechanism of PP4C in lung cancer remains unclear. METHODS: Bioinformatic analysis was used to detect the expression level and prognosis of patients. Western blot, quantitative real-time PCR (qRT-PCR), CCK8, 5-Ethynyl-2'-deoxyuridine (Edu) proliferation assay and flow cytometric were used to explore the function in lung cancer cells. RESULTS: In this study, we found that PP4C was upregulated in lung cancer tissues as compared with that in normal lung tissues. Furthermore, patients with high expression level of PP4C were correlated with a poor prognosis in lung cancer patients. In vitro, CCK8, Edu proliferation assays and flow cytometry analysis showed that PP4C could promote lung cancer cell growth and inhibit apoptosis. Mechanistic investigations revealed that PP4C may interact with PP4R1 and promote ERK activation. Additionally, PP4C depletion resulted in lower tumor growth in vivo. CONCLUSIONS: Taken together, these data showed the oncogenic of PP4C in NSCLC tumorigenesis and provide a new insight of PP4C in the progression of NSCLC.

5.
Org Biomol Chem ; 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32195526

RESUMO

Xylarilongipins A (1) and B (2), two diterpenes each with an unusual cage-like bicyclo[2.2.2]octane moiety, along with their biosynthetic precursor hymatoxin L (3), were isolated from the culture broth of the fungicolous fungus Xylaria longipes HFG1018 inhabiting in the medicinal fungus Fomitopsis betulinus. The structures and absolute configurations of the three compounds were established by extensive spectroscopic analysis and single-crystal X-ray diffraction analysis. Xylarilongipin A (1) displayed moderate inhibitory activity against the cell proliferation of concanavalin A-induced T lymphocytes and lipopolysaccharide-induced B lymphocytes with IC50 values of 13.6 and 22.4 µM, respectively. Additionally, the biosynthetic pathways for compounds 1-3 are discussed. This work not only corroborates the structure of the 9,16-cyclo-(18-nor-)isopimarane skeleton by single-crystal X-ray diffraction analysis for the first time, but also provides new insights into the biosynthetic origin of the unusual diterpene skeletons.

6.
Sci Total Environ ; 723: 137909, 2020 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-32222498

RESUMO

Imidacloprid is the most widely used neonicotinoid insecticide and has been reported to pose a threat to ecological security and human health. Therefore, simple-to-operate and highly sensitive methods for the detection of trace levels of imidacloprid are necessary. Here, we isolated two phage-borne peptides that compete with imidacloprid to bind the monoclonal antibody (mAb) 3D11 from phage display peptide libraries. A phage-enzyme-linked immunosorbent assay (P-ELISA) and two phage time-resolved fluoroimmunoassays (P-TRFIAs) for the detection of imidacloprid were developed using the phage-borne peptides as substitutes for chemically synthesized antigens. After systematic optimization, the half-maximum inhibition concentrations (IC50) of the P-ELISA, P-TRFIA-1, and P-TRFIA-2 were 0.067 ng mL-1, 0.085 ng mL-1, and 0.056 ng mL-1, respectively. Based on their IC50 values, the sensitivities of the P-ELISA and P-TRFIAs were more than four times greater than those of previous immunoassays. Additionally, the immunoassays showed satisfactory recovery in the detection of spiked samples and good correlation with high performance liquid chromatography (HPLC) for the detection of samples containing incurred residues.

7.
Artigo em Inglês | MEDLINE | ID: mdl-32040033

RESUMO

Resveratrol (Res) was recently reported to ameliorate hypoxia/reoxygenation (H/R)-caused oxidative stress in H9c2 cardiomyocytes through promoting the mitochondrial translocation of DJ-1 protein and subsequently preserving the activity of mitochondrial complex I. However, it is noteworthy that DJ-1 possesses no mitochondria-targeting sequence. Therefore, how Res induces DJ-1 mitochondrial translocation is an important and interesting question for further exploration. Glucose regulated protein 75 (Grp75), whose N-terminus contains a 51-amino acid long mitochondrial-targeting signal peptide, is a cytoprotective chaperone that partakes in mitochondrial import of several proteins. Here, the contribution of Grp75 to mitochondrial import of DJ-1 by Res was investigated in a cellular model of H/R. Our results showed that Res upregulated the expression of DJ-1 protein, enhanced the interaction of DJ-1 and Grp75, and promoted DJ-1 translocation to mitochondria from cytosol in H9c2 cardiomyocytes undergoing H/R. Importantly, knockdown of Grp75 markedly reduced the interaction of DJ-1 with Grp75 and subsequent DJ-1 mitochondrial translocation induced by Res. Furthermore, Res pretreatment promoted the association of DJ-1 with ND1 and NDUFA4 subunits of complex I, preserved the activity of complex I, decreased mitochondria-derived reactive oxygen species production, and eventually ameliorated H/R-caused oxidative stress damage. Intriguingly, these effects were largely prevented also by siRNA targeting Grp75. Overall, these results suggested that Grp75 interacts with DJ-1 to facilitate its translocation from cytosol to mitochondria, which is required for Res-mediated preservation of mitochondria complex I and cardioprotection from H/R-caused oxidative stress injury.

8.
Nanotechnology ; 31(20): 205201, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-31952059

RESUMO

We present a systematic study on the effects of CF4 plasma immersion ion implantation (PIII) in Si on the phase evolution of ultra-thin Ni silicides. For 3 nm Ni, NiSi2 was formed on Si substrates with and without CF4 PIII at temperature as low as 400 °C. For 6 nm Ni, NiSi was formed on pure Si, while epitaxial NiSi2 was obtained on CF4 PIII Si. The incorporation of C and F atoms in the thin epitaxial NiSi2 significantly reduces the layer resistivity. Increasing the Ni thickness to 8 nm results in the formation of NiSi, where the thermal stability of NiSi, the NiSi/Si interface and Schottky contacts are significantly improved with CF4 PIII. We suggest that the interface energy is lowered by the F and C dopants present in the layer and at the interface, leading to phase evolution of the thin Ni silicide.

9.
J Nat Prod ; 83(2): 401-412, 2020 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-31961677

RESUMO

Eighteen new nor-isopimarane diterpenes, xylarinorditerpenes A-R (1-18), along with two previously reported compounds, 14α,16-epoxy-18-norisopimar-7-en-4α-ol (19) and the labdane-type diterpene agatadiol (20), were isolated from cultures of the fungicolous fungus Xylaria longipes HFG1018 isolated from the wood-rotting basidiomycete Fomitopsis betulinus. The structure elucidation and relative configuration assignments of 1-18 were accomplished by interpretation of spectroscopic data and through computational methods. The absolute configurations of 1, 4, and 16 were determined by single-crystal X-ray diffraction. Compounds 1-16 possess an 18- or 19-nor-isopimarane skeleton, and compounds 17 and 18 possess an 18,19-dinor-isopimarane skeleton. Compounds 2-5, 9, 14, 19, and 20 showed immunosuppressive activity but were devoid of cytotoxicity against the cell proliferation by concanavalin A-induced T lymphocytes and lipopolysaccharide-induced B lymphocytes, with IC50 values varying from 1.0 to 27.2 µM and from 16.1 to 51.8 µM, respectively.

10.
Clin Otolaryngol ; 45(1): 47-54, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31623021

RESUMO

OBJECTIVE: Neutrophil infiltration in patients with sinonasal inverted papilloma (SNIP) is significantly high. Whether IL-17, which is a potent factor mediating neutrophilic inflammation, is involved in the neutrophilic phenotype of SNIP is investigated in the current study. STUDY DESIGN: Laboratorial study. PARTICIPANTS: Nasal papilloma and inferior turbinate were collected from patients with SNIP (n = 50) and control subjects with septal deviation (n = 15). METHODS: IL-17 + cells were evaluated in tissues obtained from patients with SNIP and control subjects with septal deviation, by immunohistochemistry and flow cytometry. MAIN OUTCOME MEASURES: The IL-17 + cells were mainly localised in mononuclear cells and neutrophils, and were up-regulated in the SNIP samples compared with those in the controls. The IL-17 + T-cell subsets mainly included CD4+ (Th17, 60.0%) and CD8+ (Tc17, 30.0%), and both subsets were enhanced in the SNIP samples than controls. The total level of IL-17 + cells was significantly correlated with neutrophil infiltration in the SNIP tissues. Furthermore, the SNIP homogenates could significantly promote IL-17 production in peripheral blood mononuclear cells. CONCLUSIONS: An increase in IL-17 + cells is evident in SNIP and may be involved in neutrophil infiltration in local tissues. IL-17 could be a potential therapeutic target to relieve the neutrophilic pathological change in SNIP.

11.
Surg Endosc ; 34(1): 417-428, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30972622

RESUMO

BACKGROUND: Submucosal tunneling endoscopic resection (STER) and endoscopic submucosal excavation (ESE) were recently introduced to cure submucosal tumors (SMTs) originating from the muscularis propria (MP) layer. This study aimed to compare clinical performance and safety of STER and ESE in treating esophageal SMTs originating from the MP layer. METHODS: From January 2011 to December 2017, retrospective data collection and follow-up were applied for all STER or ESE cases with esophageal SMTs originating from the MP layer in our endoscopy center, including clinical characteristics, procedure success, efficacy, and adverse events. Subgroup analysis was further done based on tumor size and origin. RESULTS: 90 STER and 77 ESE were enrolled in this study. There were no significant difference for patient characteristics, procedure performance, and complications for ESE and STER intervention (P > 0.05). STER was faster than ESE (3.90 mm2/min vs 2.82 mm2/min, P < 0.05). For large tumors (≥ 20 mm), both techniques had the similar performance (P > 0.05), while STER led to the shorter hospitalization (4.0d vs 7.0d, P < 0.05) and lower postoperative complication (16.3% vs 45.5%, P < 0.05). For small tumors (< 20 mm), STER achieved faster operation (STER vs ESE, 2.57 mm2/min vs 1.83 mm2/min, P < 0.05). Regardless of tumor origin, there were no significant difference for both techniques, but STER resulted in short hospitalization for SMTs from the deep MP layer (STER vs ESE, 5.0d vs 7.0d, P < 0.05). During the follow-up, 2 residual and 4 recurrence occurred in the STER group, as well as 1 residual and 2 recurrence in the ESE group. CONCLUSIONS: Both STER and ESE were effective for treating esophageal SMTs originating from the MP layer. STER might be better due to its faster operation, less complications, and shorter hospitalization.

12.
Artif Cells Nanomed Biotechnol ; 48(1): 180-187, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31852309

RESUMO

Food-originated angiotensin-I-converting enzyme (ACE)-inhibitory peptides to preserve hypertension are widely investigated over the past decade. Our research aims to discovery novel ACE-inhibitory peptides from bovine milk by couple of complex proteases (alcalase and protease). By means of response surface methodology with the conditions of pH 9.01, 61.81 °C and 6.5% ratio of enzyme to substrate, the hydrolysis model contributes to best-performing ACE-inhibitory activity of 85.02%. Through the further purification by consequent ultrafiltration, macroporous resin and gel chromatography, fraction G2-2 is eventually obtained with ACE-inhibitory activity as high as 92.7%. Two novel peptides of VLPVPQ and VAPFPE are identified by Q-Exactive LC-MS/MS. The molecular docking study further suggests that two novel peptides have good combinations of the S1 and S2 active site pockets and Zn(II) of ACE. Our study provides a fitted mathematical model to produce two novel milk-derived ACE-inhibitory peptides, potentially developing the functional foods, especially for hypertension therapy as initial treatment.

13.
Sci Total Environ ; 700: 134492, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31627046

RESUMO

Graphene oxide (GO) is a carbon-based engineered nanomaterial (ENM). Using Caenorhabditis elegans as an animal model, we investigated the effect of GO exposure on protein-protein interactions. In nematodes, NLG-1/Neuroligin, a postsynaptic protein, acted only in the neurons to regulate the GO toxicity. In the neurons, DLG-1, a PSD-95 protein, and MAGI-1, a S-SCAM protein, were identified as the downstream targets of NLG-1 in the regulation of GO toxicity. PKC-1, a serine/threonine protein kinase C, further acted downstream of neuronal DLG-1 and MAGI-1 to regulate the GO toxicity. Co-immunoprecipitation analysis demonstrated the protein-protein interaction between NLG-1 and DLG-1 or MAGI-1. After GO expression, this protein-protein interaction between NLG-1 and DLG-1 or MAGI-1 was significantly inhibited. Therefore, our data raised the evidence to suggest the potential of GO exposure in disrupting protein-protein interactions in organisms.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/fisiologia , Grafite/toxicidade , Substâncias Perigosas/toxicidade , Animais , Moléculas de Adesão Celular Neuronais/metabolismo , Guanilato Quinases
14.
Food Chem ; 309: 125669, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31683148

RESUMO

The fluorescence spectra of oil samples were obtained by laser-induced fluorescence spectroscopy and thermal oxidation stoichiometry at room temperature and 80 °C respectively. The Support Vector Machine, combined with Principal Component Analysis-Linear Discriminant Analysis (PCA-LDA), could distinguish pure extra virgin olive oils (EVOO) from oils adulterated with 2% soybean oil, with a recognition rate of 100%. Besides, as the intensity of the fluorescence spectra and concentration of the adulterants showed a non-linear relationship, linear dimension reduction methods may lead to overlapping of the different adulterated concentrations features, resulting in large errors in quantifying adulteration. In this paper, Kernel Principal Component Analysis-Linear Discriminant Analysis (KPCA-LDA) was applied instead of PCA-LDA to extract fluorescence spectra features, and a Partial Least Squares Regression model was established, which could quantify adulterants such as low percentages of soybean oil in EVOO. The coefficient of determination and root mean squared error were 0.92 and 2.72%, respectively.


Assuntos
Contaminação de Alimentos/análise , Lasers , Azeite de Oliva/química , Espectrometria de Fluorescência/métodos , Análise Discriminante , Análise dos Mínimos Quadrados , Oxirredução , Análise de Componente Principal , Óleo de Soja/química , Temperatura Ambiente
15.
Molecules ; 25(1)2019 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-31878239

RESUMO

DJ-1 was recently reported to be involved in the cardioprotection of hypoxic preconditioning (HPC) against hypoxia/reoxygenation (H/R)-induced oxidative stress damage, by preserving mitochondrial complex I activity and, subsequently, inhibiting mitochondrial reactive oxygen species (ROS) generation. However, the molecular mechanism by which HPC enables mitochondrial translocation of DJ-1, which has no mitochondria-targeting sequence, to preserve mitochondrial complex I, is largely unknown. In this study, co-immunoprecipitation data showed that DJ-1 was associated with glucose-regulated protein 75 (Grp75), and this association was significantly enhanced after HPC. Immunofluorescence imaging and Western blot analysis showed that HPC substantially enhanced the translocation of DJ-1 from cytosol to mitochondria in H9c2 cells subjected to H/R, which was mimicked by DJ-1 overexpression induced by pFlag-DJ-1 transfection. Importantly, knockdown of Grp75 markedly reduced the mitochondrial translocation of DJ-1 induced by HPC and pFlag-DJ-1 transfection. Moreover, HPC promoted the association of DJ-1 with mitochondrial complex I subunits ND1 and NDUFA4, improved complex I activity, and inhibited mitochondria-derived ROS production and subsequent oxidative stress damage after H/R, which was also mimicked by pFlag-DJ-1 transfection. Intriguingly, these effects of HPC and pFlag-DJ-1 transfection were also prevented by Grp75 knockdown. In conclusion, these results indicated that HPC promotes the translocation of DJ-1 from cytosol to mitochondria in a Grp75-dependent manner and Grp75 is required for DJ-1-mediated protection of HPC on H/R-induced mitochondrial complex I defect and subsequent oxidative stress damage.

16.
J Oral Pathol Med ; 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31841247

RESUMO

OBJECTIVE: The aim of this study was to explore the potential role and regulatory mechanism of microRNA (miR)-222-3p in oral squamous cell carcinoma (OSCC). METHODS: The expression level and prognostic significance of miR-222-3p was detected in OSCC tissues. CCK-8, transwell, and flow cytometry assays were used to explore the effect of miR-222-3p on cell proliferation, migration, invasion, and apoptosis. The influence of miR-222-3p on cyclin-dependent kinase inhibitor 1B (CDKN1B) expression was evaluated by luciferase assays, real-time polymerase chain reaction, and Western blot. RESULTS: We found that miR-222-3p was overexpressed in OSCC tissues, comparing with normal tissues. Kaplan-Meier curves showed that OSCC patients with high expression of miR-222-3p (P = .003) showed worse overall survival than those patients with low expression of miR-222-3p. Multivariate analysis showed that miR-222-3p (P = .037) expression was an independent prognostic factor of OSCC patients. miR-222-3p promoted cell proliferation, migration and invasion and induced the apoptosis of SCC-15 and Tca-83 cells. Furthermore, luciferase reporter assays indicated that CDKN1B is targeted by miR-222-3p in OSCC cells. Overexpression of CDKN1B inhibited OSCC cell proliferation, migration, and invasion and promoted cell apoptosis rate. CONCLUSIONS: miR-222-3p affects OSCC cell proliferation, migration, invasion, and apoptosis through targeting CDKN1B, and may be a potential prognostic biomarker for OSCC patients.

17.
Appl Opt ; 58(28): 7789-7794, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31674462

RESUMO

Conventional Czerny-Turner spectrometers exhibit keystone distortion due to astigmatism, which affects their performance when a linear array photomultiplier tube (LaPMT) is used as the detector. We propose a novel optical design of a crossed Czerny-Turner spectrometer with a 32-channel LaPMT detector. We use convergent illumination of the grating to modify the astigmatism of the off-axis spherical mirrors, and the image spot radius at the central wavelength in the sagittal plane is matched with the width of the LaPMT. A first-order equation is derived for the elimination of the broadband keystone distortion. After optimization, the image size over the entire bandwidth matches well with the LaPMT size, which is consistent with the theory, and the spectral resolution is ∼4 nm per channel.

18.
Pain Res Manag ; 2019: 5930627, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31781318

RESUMO

Objectives: To review the evidence of acupuncture for acute and preventive treatment of migraine for further awareness of the effect of acupuncture for migraine. Design: An overview of systematic reviews and meta-analyses (SR/MAs) for randomized controlled trials. Material and Methods: We searched PubMed, Embase, the Cochrane Library, China Knowledge Resource Integrated Database, VIP Chinese Journal Full Text Database, WANFANG Data, and China Biology Medicine disc from their establishment to May 27, 2018. SR/MAs of randomized controlled trials comparing the effect of the acupuncture intervention with another treatment control in migraine patients were included. Results: 428 SRs were identified, and 15 of them were included. Only 4 SR/MAs were assessed by GRADE, which showed certainty of most evidence being low or very low. Assessed by AMSTAR-2, fourteen was critically low rating overall confidence in the results, and 1 was low rating overall confidence in the results. Evidence suggested that acupuncture has a significant advantage of pain improvement, efficacy, and safety relative to blank control, sham acupuncture, or drug treatment, but some of these results are contradictory. Conclusions: We found that acupuncture on treating migraine has the advantage for pain improvement and safety, but the quality of SR/MAs of acupuncture for migraine remains to be improved.

19.
Math Biosci Eng ; 16(6): 6350-6366, 2019 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-31698566

RESUMO

Secret image sharing has been widely applied in numerous areas, such as military imaging systems, remote sensing, and so on. One of the problems for image sharing schemes is to efficiently recover original images from their shares preserved by the shareholders. However, most of the existing schemes are based on the assumption that the shares are distortion-free. Moreover, the correspondence between secret images and their shares is definite. To overcome these shortcomings, we propose a novel secret sharing scheme using multiple share images based on the generalized Chinese remainder theorem (CRT) in this paper, where all of the shares are needed to recover the original images. Two categories of distortions are considered. In the first category, some pairs of shares with the same moduli are exchanged, while in the second category, some of pixels in the pairs of shares with the same moduli are exchanged. Based on these two sharing methods, we propose a generalized CRT based recovery method. Compared with the existing CRT based methods as well as combinatorial based methods, the proposed approach is much more efficient and secure. Furthermore, the conditions for successful recovery of two images from the given distorted shares are obtained. Simulations are also presented to show the efficiency of the proposed scheme.

20.
Fitoterapia ; 139: 104362, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31629052

RESUMO

Ochracines A-E, five previously undescribed norsesquiterpenes featured by unusual scaffolds biogenetically related to chamigrane, were isolated from the cultures of Steccherinum ochraceum. Ochracines A (1) and B (2) represent the first examples of norsesquiterpenes with an unprecedented 1,2-6,7-diseco-1,8-cyclochamigrane scaffold. Ochracines C-D (3-5) possess an unusual 1,2-6,7-diseco-chamigrane skeleton. Their structures were elucidated by analysis of spectroscopic data. The absolute configuration of ochracine A (1), and the relative configuration of ochracine B (2) were determined by ECD and/or NMR calculations. The biosynthetic pathways for the norsesquiterpenes were proposed. All isolates were evaluated for their cytotoxicity against the five human cancer cell lines HL-60, SMMC-7721, A549, MCF-7, and SW-480.


Assuntos
Polyporales/química , Sesquiterpenos/farmacologia , Linhagem Celular Tumoral , China , Humanos , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Sesquiterpenos/isolamento & purificação
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