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1.
Food Chem ; 356: 129684, 2021 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-33812194

RESUMO

In this study, we aim to develop a novel loop mediated isothermal amplification (LAMP) coupled with TaqMan (LAMP-TaqMan) method for quick qualitative detection of genetically modified organism (GMOs). We designed four LAMP primers and one TaqMan probe for the LAMP-TaqMan detection method to detect the nopaline synthase gene (NOS) terminator in GMOs. This assay enabled the amplification of DNA within ~20 min at a constant temperature of 65 °C. This assay detected as few as five copies of target sequences, which had a high specificity similar to the TaqMan qPCR method. Furthermore, the LAMP-TaqMan detection method was successfully used to amplify and detect DNA from food samples of the major crops (soybean, maize, rice, etc.). In summary, a novel LAMP-TaqMan assay has been developed, which has the similar sensitivity but takes less time than the TaqMan qPCR method. This method offers a novel approach for rapid detection of GMOs in foods.

2.
Water Res ; 195: 116956, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33676178

RESUMO

Due to the hydrophobicity and large specific surface area microplastics (MPs) have become the vector for the migration of environmental organic pollutants. Environmental aging process affects the physiochemical structure of MPs and their corresponding environmental behaviors, in which the effect of bisphenol A (BPA) binding mode within plastic matrix on aging behaviors of MPs is not reported. In this work, the structural properties and BPA sorption behaviors of low density polyethylene (LDPE) MPs with BPA additives and polycarbonate (PC) MPs with BPA monomers exposed to three types of artificial accelerated aging processes including UV/H2O, UV/H2O2, and UV/Cl2 systems were comparatively investigated. Virgin LDPE and PC exhibited obvious leakage of BPA additives or monomers. Aged LDPE had stronger sorption ability towards BPA in water environment with no observed leakage of BPA additives. While, aged PC had extremely high leakage of BPA monomers, which is similar to virgin PCs and was proved to be a persistent source of BPA release. The BPA sorption on aged LDPE or leaching from aged PC was influenced by aging processes, water pH, salinity, co-existing estradiol (E2), and water sources. This study reveals the potential ecological and environmental risks of MPs containing toxic additives/monomers during aging processes from a new perspective.


Assuntos
Microplásticos , Poluentes Químicos da Água , Adsorção , Compostos Benzidrílicos , Peróxido de Hidrogênio , Fenóis , Plásticos , Água , Poluentes Químicos da Água/análise
3.
Eur Urol ; 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33579577

RESUMO

BACKGROUND: Whether AR-V7 expression can predict the response in patients with metastatic hormone-sensitive prostate cancer (mHSPC) who receive androgen deprivation therapy (ADT) remains to be explored. OBJECTIVE: To evaluate the predictive value of AR-V7 expression in the prognosis of mHSPC patients receiving ADT. DESIGN, SETTING, AND PARTICIPANTS: In this multicenter prospective cohort study, 310 mHSPC patients commencing ADT were enrolled. Standard immunohistochemical staining was used to assess AR-V7 protein expression in biopsy tissues collected before initiation of ADT. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Kaplan-Meier survival estimates and Cox regression analyses were used to evaluate associations of AR-V7 status (positive vs negative) with progression-free survival (PFS) and overall survival (OS). RESULTS AND LIMITATIONS: Sixty-four (21%) patients were AR-V7-positive and 246 (79%) patients were AR-V7-negative. The median follow-up for patients not confirmed dead was 25 mo (interquartile range 10-30). Compared to AR-V7-negative patients, AR-V7-positive patients had significantly shorter PFS (hazard ratio [HR] 47.39, 95% confidence interval [CI] 25.83-86.94) and OS (HR 3.57, 95% CI 1.46-8.72). In multivariable analysis, AR-V7 was an independent predictive factor (HR 7.61, 95% CI 5.24-11.06) for shorter PFS. Limitations include the sample size and follow-up period. CONCLUSIONS: AR-V7 expression in primary cancer tissue is correlated with poor prognosis for mHSPC patients receiving ADT. PATIENT SUMMARY: In this study of men with metastatic hormone-sensitive prostate cancer, AR-V7 protein expression in primary cancer tissue was associated with poor outcomes on androgen deprivation therapy.

4.
J Pharm Biomed Anal ; 197: 113946, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33611089

RESUMO

Cetrorelix, a potent third generation of luteinizing hormone releasing hormone (LHRH) antagonist, is a synthetic decapeptide used for treatment of infertility, prostatic hypertrophy and sexual hormone-dependent tumors. The approved drug of cetrorelix (Cetrotide, Asta Medica AG, Frankfurt, Germany.), was used for prevention of premature ovulation in patients undergoing a controlled ovarian stimulation (COS), followed by oocyte pick-up and assisted reproductive techniques, and has been shown safe and effective in controlled ovarian stimulation. Nevertheless, the study of aggregation products of cetrorelix was rarely reported. A simple liquid chromatography mass spectrometry (LC-MS/MS) method was developed for separation, identification and characterization of a new cetrorelix methylene dimer impurity in cetrorelix. The chromatographic separation was achieved on an XSelect Peptide CSH ™C18 column (150 × 4.6 mm, 3.5 µm particle size) using gradient elution with a mobile phase of ammonium formate buffer (pH 3.0, 20 mM), acetonitrile at a flow rate 1.0 mL min-1, and an ultraviolet detection wavelength of 226 nm. The new cetrorelix methylene dimer impurity was characterized by LC-MS/MS and it characteristic fragment ions were summarized. A simple, fast and accurate method was established for the determination of the molecular weight and structure of the new cetrorelix methylene dimer impurity. In this study, the results showed that the cetrorelix was highly unstable in formaldehyde conditions. In addition, it is proposed that the impact of formaldehyde in the environment on the quality of cetrorelix acetate for Injection should be evaluated during the production process.

5.
J Cancer Res Clin Oncol ; 147(3): 767-777, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33389075

RESUMO

PURPOSE: Approximately 60% of patients with melanoma harbor BRAF mutation and targeting BRAF offers enormous advance in the treatment of those patients. Unfortunately, the efficacy of the BRAF inhibitors is usually restricted by the onset of drug resistance. Therefore, better understanding of the adaptive drug resistance mechanisms is essential for the development of alternative therapeutic strategies, and offers more promising measures to promote the short duration of response to BRAF inhibitors. METHODS: The levels of tumor suppressive long noncoding RNA on chromosome 8p12 (TSLNC8) were evaluated by qPCR. The MTT assay, colony formation assay, apoptosis assay, and in vivo xenograft tumor model were performed to assess the functions of TSLNC8 on drug resistance. Western blotting, RNA pull-down, and RNA immunoprecipitation (RIP) assays were applied to investigate the mechanisms of TSLNC8 in melanoma. RESULTS: Herein, our findings demonstrate that TSLNC8 is significantly downregulated in BRAF inhibitor-resistant melanoma tissues and cells. Moreover, downregulation of TSLNC8 in BRAF inhibitor sensitive cells reduces the toxicity response to BRAF inhibitor PLX4720, and inhibits apoptosis of melanoma cells-treated with PLX4720. Further assay elucidates that TSLNC8 can bind with the catalytic subunit of protein phosphatase 1α (PP1α) to regulate its distribution, and Downregulation of TSLNC8 results in PP1α cytoplasmic accumulation, thus re-activating the MAPK signaling. Eventually, the overexpression of TSLNC8 in BRAF inhibitor PLX4720-resistant melanoma cells restores the sensitive to BRAF inhibitor. CONCLUSION: Collectively, our research provides a compelling rationale for resistance to BRAF inhibitor in melanoma, and the patient might benefit from the combinatorial therapy of BRAF inhibitors and lncRNA TSLNC8.


Assuntos
Indóis/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Melanoma/tratamento farmacológico , Proteína Fosfatase 1/metabolismo , RNA Longo não Codificante/metabolismo , Sulfonamidas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos , Feminino , Células HEK293 , Humanos , Melanoma/genética , Melanoma/metabolismo , Melanoma/patologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , RNA Longo não Codificante/genética , Ensaios Antitumorais Modelo de Xenoenxerto
6.
J Ethnopharmacol ; 269: 113719, 2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33358856

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Hanchuan Zupa Granule (HCZP), a traditional Chinese ethnodrug, has the functions of supressing a cough, resolving phlegm, warming the lungs, and relieving asthma. In clinical practice employing traditional Chinese medicine (TCM), HCZP is commonly used to treat acute colds, cough and abnormal mucous asthma caused by a cold, or "Nai-Zi-Lai" in the Uygur language. Studies have confirmed the use of HCZP to treat cough variant asthma (CVA) and other respiratory diseases. However, the pharmacological mechanisms of HCZP remain unrevealed. AIM OF THE STUDY: To investigate the anti-tussive and anti-asthmatic effects and the possible pharmacological mechanisms of HCZP in the treatment of CVA. MATERIALS AND METHODS: A guinea pig CVA animal model was established by intraperitoneal injection of ovalbumin (OVA) combined with intraperitoneal injection of aluminium hydroxide adjuvant and atomized OVA. Meanwhile, guinea pigs with CVA received oral HCZP (at dosages of 0.571, 0.285 and 0.143 g/kg bodyweight). The number of coughs induced by aerosol capsaicin was recorded, and the airway hyperresponsiveness (AHR) of CVA guinea pigs was detected with the FinePointe series RC system. H&E staining of lung tissues was performed to observe pathological changes. ELISA was used to detect inflammatory cytokines. qRT-PCR and western blotting analyses were used to detect the expression of Th1-specific transcription factor (T-bet), Th2-specific transcription factor (GATA3), and Toll-like receptor 4 (TLR4) signal transduction elements. These methods were performed to assess the protective effects and the potential mechanisms of HCZP on CVA. RESULTS: Great changes were found in the CVA guinea pig model after HCZP treatment. The number of coughs induced by capsaicin in guinea pigs decreased, the body weights of guinea pigs increased, and inflammation of the eosinophilic airway and AHR were reduced simultaneously. These results indicate that HCZP has a significant protective effect on CVA. A pharmacological study of HCZP showed that the levels of interleukin-4 (IL-4) and IL-5 and tumour necrosis factor-α (TNF-α) in serum decreased. The amount of interferon-γ (IFN-γ) increased, mRNA and protein expression of TLR4 and GATA3 weakened, and mRNA and protein expression of T-bet increased. CONCLUSIONS: HCZP ameliorated the symptoms of guinea pigs with CVA induced by OVA by regulating the Th1/Th2 imbalance and TLR4 receptors.

7.
Chem Commun (Camb) ; 2020 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-33220663

RESUMO

We report the cyclic single-crystal-to-single-crystal transformation of three hydrogen-bonded organic frameworks (HOFs), induced by the change of temperature and humidity, which clearly reveals that the -SO3-and -NH2 groups in UPC-H7 and UPC-H8 facilitate the diffusion of water molecules into their anhydrous structures to form hydrous UPC-H9. Their proton conductivity was studied under different humidity at varying temperature, showing that the proton conductivity is closely related to water molecules entering the crystal structures arising from the hydrogen bonded reorganization in combination with the triaxial single-crystal proton conductivity tests.

8.
Dev Comp Immunol ; 116: 103928, 2020 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-33242568

RESUMO

Cathelicidins are an important family of antimicrobial peptides (AMPs), which play pivotal roles in vertebrate immune responses against microbial infections. They are regarded as potential drug leads for the development of novel antimicrobial agents and three related drugs have been developed into clinical trials. Thus, it is meaningful to identify more cathelicidins from vertebrate species. Cathelicidins from ranid frogs possess special structural characteristics and activities, but to date only 12 ranid frog cathelicidins have been identified. In the present study, two novel cathelicidins (PN-CATH1 and 2) were identified from the black-spotted frog, Pelophylax nigromaculata. PN-CATHs possess low sequence similarity with the known cathelicidins. They exhibited moderate, but broad-spectrum and rapid antimicrobial activities against the tested bacteria. They kill bacteria by mainly inducing bacterial membrane disruption and possibly generating intracellular ROS formation. They also possess potent anti-biofilm and persister cell killing activity, indicating their potential in combating infections induced by biofilms-forming bacteria. Besides direct antimicrobial activity, they exhibited potent anti-inflammatory activity by effectively inhibiting the LPS-induced production of pro-inflammatory cytokines in mouse macrophages, which could be partly ascribed to their direct LPS-neutralizing ability. Furthermore, PN-CATHs demonstrated powerful in vitro free radical scavenging activities. Ultraviolet radiation significantly increased their in vivo gene expression in frog skin. Meanwhile, they possess weak cytotoxic activity and extremely low hemolytic activity. PN-CATHs represent the first discovery of cathelicidins family AMPs with both potent anti-infective and antioxidant activities. The discovery of PN-CATHs provides potential peptide leads for the development of novel anti-infective and antioxidant drugs.

9.
J Opt Soc Am A Opt Image Sci Vis ; 37(11): 1806-1813, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-33175757

RESUMO

Free-space propagation and experimental generation of a partially coherent radially polarized (PCRP) vortex beam were studied recently [Opt. Express24, 13714 (2016)OPEXFF1094-408710.1364/OE.24.013714]. In this work, we explore the statistical properties of such a PCRP vortex beam propagating in a uniaxial crystal. We show that the anisotropy of the refractive index of the uniaxial crystal induces the asymmetrical distribution of the intensity, the degree and the state of polarization, as well as the degree of coherence of the beam during propagation. Further, by comparing the asymmetrical distribution of the statistical properties of the PRCP vortex beam with those of a PRCP beam without a vortex phase, we find that the asymmetrical features can be used for determining whether a PCRP beam carries the vortex phase. Further, we show that from the far-field distribution of the degree of coherence, we could quantify the topological charge and distinguish the handedness of the vortex phase. Our findings provide a novel approach for measuring the phase information of the partially coherent vortex beams.

10.
Onco Targets Ther ; 13: 9419-9428, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33061428

RESUMO

Purpose: The retinoblastoma binding protein RBP2 (KDM5A) is a histone demethylase that promotes cell growth in many human cancers. A series of functional experiments were conducted to explore the role of miR-421/KDM5A in ovarian cancer cells and their underlying molecular mechanisms. Materials and Methods: Public microarray databases were analyzed to assess KDM5A and miR-421 expression in ovarian cancer. KDM5A was predicted to be a target of miR-421 using software analysis. The expression of the miR-421/KDM5A regulatory axis in ovarian cancer and the mechanisms of its effects on proliferation, migration, and invasion of ovarian cancer cell lines were investigated. Results: Compared with normal ovarian tissues, the expression of KDM5A mRNA and protein was elevated (P<0.05), and miR-421 expression was reduced in ovarian cancer tissue (P<0.05). miR-421 was found to bind specifically to the KDM5A gene. Silencing KDM5A or overexpressing miR-421 significantly inhibited proliferation, migration, and invasion of OVCAR-8 and SKOV-3 cells. Similarly, compared with nude mice injected with cells transfected with empty capsids, the in vivo proliferation rate of OVCAR-8 cells after miR-421 overexpression was reduced significantly. Conclusion: The miR-421/KDM5A regulatory axis plays an important role in the development and progression of ovarian cancer cells.

11.
Plant Genome ; 13(2): e20020, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33016612

RESUMO

Long non-coding RNAs (lncRNAs) are essential regulators of a broad range of biological processes in plants. The spectacular progress made in next-generation sequencing technologies has enabled a genome-wide identification of lncRNAs in multiple plant species. In this study, a genome-wide lncRNA sequencing technology was used to identify cold-responsive lncRNAs at the booting stage in rice by comparing a tolerant variety, Kongyu131 (KY131) and a sensitive variety, Dongnong422 (DN422). A total of 1485 lncRNAs were identified, and 566 of these lncRNAs were defined as differential lncRNAs by comparing four samples. GO and KEGG enrichment analyses were performed, focusing on the cis- and trans- target genes of the differential lncRNAs. To identify cold-responsive genes, a meta-analysis was used to integrate 35 cold-tolerant QTLs at the booting stage. In summary, 12 candidate genes and their target lncRNAs were identified by qRT-PCR. LncTar was used to identify the interaction between lncRNAs and the candidate genes. In addition, 130 rice cultivars with rich genetic diversity were collected to verify the association of candidate genes with cold-resistance. The results revealed that five SNPs in LOC_Os07g42940, three SNP and one InDel in LOC_Os02g03410 were associated with cold-resistance at a significant level using association analysis. This study provides new gene resources and insights into cold-resistance research for rice.


Assuntos
Oryza , RNA Longo não Codificante , Mapeamento Cromossômico , Sequenciamento de Nucleotídeos em Larga Escala , Oryza/genética , Locos de Características Quantitativas , RNA Longo não Codificante/genética
12.
Anal Chem ; 92(20): 14153-14163, 2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-32955242

RESUMO

A compact multigas sensor system based on a single quartz crystal tuning fork (QCTF) and multifrequency synchronous modulation strategy is proposed for trace gas detection. To demonstrate the novel detection technique, three near-infrared continuous-wave (CW) distributed feedback (DFB) diode lasers with center wavelengths of near 1391, 1574, and 1653 nm and a standard 32 kHz QCTF were integrated for simultaneous detection of H2O, CO2, and CH4, respectively. Wavelength modulation spectroscopy with second harmonic detection (WMS-2f) was selected for enhancing sensitivity. Design of the sensor configuration and primary performance between the traditional single-frequency modulation and the proposed tri-frequency modulation were experimentally investigated and compared in detail. The results indicate that the proposed sensing technique has significant advantages of cost effectiveness, portability, and ease-of-use, and detection limits of 1.4, 353, and 3.1 ppm for simultaneously measuring H2O, CO2, and CH4, respectively, are obtained, corresponding to the normalized noise equivalent absorption (NNEA) coefficients of 2.65 × 10-10, 8.09 × 10-10, and 8.28 × 10-10 cm-1 W/√Hz, respectively. Moreover, the use of an erbium-doped fiber amplifier (EDFA) has been demonstrated as an effective method for sensitivity enhancement.

13.
Biomed Res Int ; 2020: 8916729, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32851091

RESUMO

AURKA, a cell cycle-regulated kinase, is associated with malignant transformation and progression in many cancer types. We analyzed the expression change of AURKA in pan-cancer and its effect on the prognosis of cancer patients using the TCGA dataset. We revealed that AURKA was extensively elevated and predicted a poor prognosis in most of the detected cancer types, with an exception in colon cancer. AURKA was elevated in colon cancer, but the upregulation of AURKA indicated better outcomes of colon cancer patients. Then we revealed that undermethylation of the AURKA gene and several transcription factors contributed to the upregulation of AURKA in colon cancer. Moreover, we demonstrated that AURKA overexpression promoted the death of colon cancer cells induced by Oxaliplatin, whereas knockdown of AURKA significantly weakened the chemosensitivity of colon cancer cells to Oxaliplatin. Mechanistically, AURKA inhibited DNA damage response by suppressing the expression of various DNA damage repair genes in a TP53-dependent manner, which can partly explain that ARUKA is associated with a beneficial outcome of colon cancer. This study provided a possibility to use AURKA as a biomarker to predict the chemosensitivity of colon cancer to platinum in the clinic.

14.
Biomed Res Int ; 2020: 5024942, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32802850

RESUMO

Growing evidence indicates that immune-related biomarkers play an important role in tumor processes. This study investigates immune-related gene expression and its prognostic value in lung squamous cell carcinoma (LUSC). A cohort of 493 samples of patients with LUSC was collected and analyzed from data generated by the TCGA Research Network and ImmPort database. The R coxph package was employed to mine significant immune-related genes using univariate analysis. Lasso and stepwise regression analyses were used to construct the LUSC prognosis prediction model, and clusterProfiler was used for gene functional annotation and enrichment analysis. The Kaplan-Meier analysis and ROC were used to evaluate the model efficiency in predicting and classifying LUSC case prognoses. We identified 14 immune-related genes to incorporate into our prognosis model. The patients were divided into two subgroups (Risk-H and Risk-L) according to their risk score values. Compared to Risk-L patients, Risk-H patients showed significantly improved overall survival (OS) in both training and testing sets. Functional annotation indicated that the 14 identified genes were mainly enriched in several immune-related pathways. Our results also revealed that a risk score value was correlated with various signaling pathways, such as the JAK-STA signaling pathway. Establishment of a nomogram for clinical application demonstrated that our immune-related model exhibited good predictive prognostic performance. Our predictive prognosis model based on immune signatures has potential clinical implications for assessing the overall survival and precise treatment for patients with LUSC.

15.
Materials (Basel) ; 13(16)2020 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-32784570

RESUMO

Although stimuli-responsive release systems have attracted great attention in medical applications, there has been no attempt at "precise" deep profile control based on such systems, which is greatly need to improve oil recovery. With this in mind, we provided a facile and simple strategy to prepare stimuli-responsive composite capsules of amphiphilic dendrimers-poly(styrene sulfonic acid) sodium/halloysite nanotubes (HNTs) via layer-by-layer (LbL) self-assembly technique, controlling the release crosslinking agent methenamine under different pH or salinity conditions. The release time of methenamine encapsulated in multilayer shells is about 40 h, which can be prolonged with the introduction of salt or shortened via the addition of acid, which accordingly induces the gelation of polyacrylamide (PAM) solutions, taking from a few hours to a dozen days. This study provided a novel approach for controllable release of chemical agents and controllable crosslinking of deep profiles in many application fields.

16.
ACS Infect Dis ; 6(9): 2451-2467, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32786271

RESUMO

Infections caused by drug-resistant pathogens are a worldwide challenge for public health. Antimicrobial peptides (AMPs) are regarded as promising antibiotic alternatives for the treatment of drug-resistant infections. In the present study, a series of small peptides were designed based on our previously reported sea snake AMP Hc-CATH. From them, the lead peptide HC1-D2, a truncated peptide entirely substituted by d-amino acids, was selected. HC1-D2 exhibited significantly improved stability and antibiofilm and anti-inflammatory activities. Meanwhile, HC1-D2 retained potent, broad-spectrum, and rapid antimicrobial properties against bacteria and fungi, especially drug-resistant bacteria. Moreover, HC1-D2 showed low propensity to induce bacterial resistance and low cytotoxicity and hemolytic activity. Notably, HC1-D2 showed potent in vivo anti-infective ability in mouse peritonitis models infected by both standard and drug-resistant bacteria. It significantly decreased the bacterial counts in the abdominal cavity and spleen of mice and apparently increased the survival rates of the mice. Acting through the MAPKs inflammatory pathway, HC1-D2 selectively induced the production of chemokine and the subsequent immune cell recruitment to the infection site, while inhibiting the production of pro-inflammatory cytokines with undesirable toxicities. These much improved properties make HC1-D2 a promising candidate for the development of novel peptide anti-infective agents against drug-resistant infections.

17.
Int J Biol Macromol ; 164: 184-192, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32679333

RESUMO

Xylosidases with tolerance to high concentration of salts, organic solvents, and enzyme hydrolytic products are preferential for industrial application but were rarely reported. In this study, a novel xylosidase XYL21 belong to glycoside hydrolase 39 was characterized with optimal temperature of 45 °C and optimal pH of 5.50. Different to other GH39 xylosidases, XYL21 had excellent tolerance to salts, the activity of which is not inhibited but slightly increased in 0.50-1.50 M NaCl. It is also tolerant to organic solvents, especially retaining 105.18% relative activity even in the presence of 15.00% (v/v) ethanol. Moreover, XYL21 was insensitive to the final lignocellulose hydrolysis products including glucose, xylose, arabinose, mannose and galactose, which retains 111.36% and 53.49% relative activity in 0.30 and 0.90 M xylose, respectively. Further structural modeling analysis indicated that its excellent tolerance may be attributed to its high structural flexibility caused by the high proportion of random coils. Furthermore, XYL21 had a wide substrate specificity to catalyze xylan and xylo-oligosaccharides, and it significantly cooperated with xylanase to improve the hydrolysis efficiency with 1.52-fold. Considering these unique properties, XYL21 is a good candidate for both basic research and various potential industrial applications such as seafood processing and bioethanol production.

18.
Cancer Cell Int ; 20: 223, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32528231

RESUMO

Background: Osteosarcoma (OS) is a common malignant bone cancer and is still a growing threat to young people. Circular RNAs (CircRNAs) are reported to be involved in the development of diverse human cancers. However, the role of circUBAP2 in OS progression is rarely reported. Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to detect the expression levels of circUBAP2 and miR-641 in OS tissues and cells. Cell Counting Kit-8 (CCK-8) assay was employed to check cell proliferation. The ability of cell invasion was evaluated by transwell assay. The protein levels of E-cadherin, Vimentin and Yes-associated protein 1 (YAP1) were measured by western blot. The starBase was used to predict binding sites between miR-641 and circUBAP2 or YAP1 and the dual-luciferase reporter assay was performed to verify the interaction. Results: The level of circUBAP2 was significantly upregulated in OS tissues and cells compared with normal tissues and cells, which was contrary to the expression of miR-641. Downregulation of circUBAP2 suppressed proliferation and invasion of OS cells and weakened the process of epithelial-mesenchymal transition (EMT). Moreover, miR-641 was a target of circUBAP2 and could bind to the 3'-untranslated region (3'UTR) of YAP1. In addition, overexpression of circUBAP2 or YAP1 reversed the inhibitory effects of miR-641 on proliferation and invasion of OS cells. Further research indicated that circUBAP2 regulated the expression of YAP1 by interacting with miR-641 in OS cells. Conclusion: Knockdown of circUBAP2 impeded proliferation and invasion of OS cells by downregulating the expression of YAP1 via sponging miR-641.

19.
Med Image Anal ; 64: 101717, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32492584

RESUMO

Although recent deep learning methodology has shown promising performance in fast imaging, the network needs to be retrained for specific sampling patterns and ratios. Therefore, how to explore the network as a general prior and leverage it into the observation constraint flexibly is urgent. In this work, we present a multi-channel enhanced Deep Mean-Shift Prior (MEDMSP) to address the highly under-sampled magnetic resonance imaging reconstruction problem. By extending the naive DMSP via integration of multi-model aggregation and multi-channel network learning, a high-dimensional embedding network derived prior is formed. Then, we apply the learned prior to single-channel image reconstruction via variable augmentation technique. The resulting model is tackled by proximal gradient descent and alternative iteration. Experimental results under various sampling trajectories and acceleration factors consistently demonstrated the superiority of the proposed prior.

20.
J Phys Chem A ; 124(29): 6119-6123, 2020 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-32589427

RESUMO

Heat capacity is an important and fundamental thermodynamic parameter in materials. The temperature-dependent heat capacity (HC) was studied extensively. Here, the universal correlation between the experimental heat capacity Cp and the coefficient of thermal expansion ß in reference solids at high temperatures: Cp = Co + Eß (C0 and E: constants) and the volume-dependent heat capacity CTE in the temperature range from several Kelvins to melting temperatures is quantitatively determined: CTE = Eß, and a new phenomenological model of the experimental heat capacity below the melting temperature in the volume dimension is established: Cp = CT + CTE (the non-volume-dependent heat capacity CT = C0fD, fD: Debye function). Previous harmonic and anharmonic HC models explain the HC at low temperatures and high temperatures, respectively. The new model successfully explains the HC at the whole temperature range below the melting temperature and quantitatively determines the change behavior of the temperature and volume in solids after absorbing the heat.

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