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1.
Appl Opt ; 60(26): 8206-8212, 2021 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-34613085

RESUMO

Direct absorption spectroscopy (DAS) is an extremely practical and effective technology to detect gas concentration in site applications. Dual-beam subtraction is one of the most common demodulation methods in DAS, yet this method cannot solve the problem of absolute absorption curve nonlinearization in a wide optical thickness range. A real-time and practical dual-logarithmic demodulation method is proposed and proved to be robust when the optical thickness is much greater than linear region. Moreover, the error of optical thickness peak is only 1.18% between the dual-logarithmic demodulation system and simulation after correcting the dual-beam subtraction demodulation system under a 300 K, 1 atm, and 3 m absorption path. When the range of optical thickness peak of acetylene is from 0.0252 to 2.5335 at 1532.83 nm, the peak voltages always maintain satisfactory linearity (R-square=0.9989).

2.
Age Ageing ; 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34510170

RESUMO

BACKGROUND: Globally, geriatric patients are the dominant population requiring global medical care. We established a frailty index for geriatric trauma patients by retrospectively analysing electronic hospital records to identify patients with frailty characteristics and poor prognostic outcomes. METHOD: Data were obtained from 2016 US National Emergency Department Sample and Shanghai Trauma Emergency Medical Association (2015-18). Overall, 141,267 hospitalised geriatric trauma patients (age ≥ 65 years) were included. We used a three-step method to construct geriatric trauma frailty index (GTFI) based on the International Statistical Classification of Diseases and Related Health Problems, Tenth Revision diagnostic codes. Systematic cluster analysis was used. The accuracy of GTFI was verified in national validation cohort, and its applicability to Chinese patients was assessed in local validation cohort. RESULTS: In development cohort (n = 28,179), frail patients had longer lengths of stay and higher Charlson co-morbidity index than non-frail patients (18.2 ± 12.4 days, 5.59 ± 2.0 versus 5.3 ± 5.3 days, 5.33 ± 1.8, respectively). In national validation cohort (n = 113,089), frail patients had longer lengths of stay (8.5 ± 8.8 days versus 4.5 ± 3.1 days) and higher in-hospital mortality than non-frail patients (2,795, 11.69% versus 589, 0.66%). Areas under the curves for GTFI for length of stay (>14 days) and in-hospital mortality were 0.848 (0.841, 0.854) and 0.885 (0.880, 0.891) in national validation cohort, and were 0.791 (0.779, 0.804) and 0.903 (0.885, 0.922) in local validation cohort (n = 14,827). CONCLUSIONS: The GTFI helps hospitals and emergency departments to identify geriatric trauma patients with poor prognostic outcomes, and has been proven to be useful in China.

3.
ACS Nano ; 2021 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-34409833

RESUMO

It is a challenge to regulate charge flow synergistically at the atomic level to modulate gradient hydrogen migration (H migration) for boosting photocatalytic hydrogen evolution. Herein, a self-adapting S vacancy (Vs) induced with atomic Cu introduction into ZnIn2S4 nanosheets was fabricated elaborately, which can tune charge separation and construct a gradient channel for H migration. Detailed experimental results and theoretical simulations uncover the behavior mechanism of Vs generation with Cu introduction after substituting a Zn atom tendentiously. Cu-S bond shrinkage and Zn-S bond distortion are presented around Vs areas. Besides, Vs induced by Cu introduction lowers the internal electric field to restrain electron transmission between layers, which are enriched on the Vs area because of the lower surface electrostatic potential. Atomic Cu and Vs show a synergistic effect for regulating regional charge separation due to the Cu dopant being a hole trap and Vs being an electron trap. The channels for H migration with gradient ΔGH0 are constructed by different S atom sites, which are modulated by Vs. Gradient H migration driven by a photothermal effect occurs on an identical surface without striding across a heterogeneous interface, which is a valid pathway with lower resistance for boosting H2 release. Ultimately, 5 mol % Cu confined in ZnIn2S4 nanosheets achieves an optimum photocatalytic hydrogen evolution activity of 9.8647 mmol g-1 h-1, which is 14.8 times higher than 0.6640 mmol g-1 h-1 for ZnIn2S4, and apparent quantum efficiency reaches 37.11% at 420 nm. This work demonstrates the behavior mechanism of atomic substitution and provides cognition for hydrogen evolution mechanism deeply.

4.
Bioresour Technol ; 340: 125718, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34388660

RESUMO

Screening of microorganisms with broad-spectrum adaptability to extreme acid-base conditions and highperformance is essential for the construction of high-efficient biochemical wastewater treatment system. Herein, an acid-tolerant fungus isolated from acid medium was successfully identified through micromorphological observation and molecular characterization. The isolated fungus matched well with the filamentous fungus and was eventually identified as Talaromyces cellulolyticus. Considering the wide-range adaptability to pH condition (2.0-9.0), high cellulase activity (11.25 U mL-1), ideal biofilm-forming property (17.87 mg cm-3) on the surface of ceramsites, high tolerance to metal ions, and potential adsorption performance for aniline dyes, T. cellulolyticus issuitable for the construction of biofilm treatment system and treatment of textile wastewater based on the investigation of the removal efficiency of chemical oxygen demand and chromaticity of the synthetic textile wastewater. A promising candidate filamentous fungus for the treatment of textile wastewater was provided.


Assuntos
Talaromyces , Biofilmes , Indústria Têxtil , Têxteis , Águas Residuárias
5.
Stem Cell Res Ther ; 12(1): 387, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34233723

RESUMO

AIMS: Neointimal hyperplasia remains a major obstacle in vascular regeneration. Sca-1-positive progenitor cells residing within the vascular adventitia play a crucial role in the assemblage of vascular smooth muscle cell (VSMC) and the formation of the intimal lesion. However, the underlying mechanisms during vascular injury are still unknown. METHODS AND RESULTS: Aneointimal formation rat model was prepared by carotid artery injury using 2F-Forgaty. After vascular injury, Meox1 expressions time-dependently increased during the neointima formation, with its levels concurrently increasing in the adventitia, media, and neointima. Meox1 was highly expressed in the adventitia on the first day after vascular injury compared to the expression levels in the media. Conversely, by the 14th day post-injury, Meox1 was extensively expressed more in the media and neointima than the adventitia. Analogous to the change of Meox1 in injured artery, Sca-1+ progenitor cells increased in the adventitia wall in a time-dependent manner and reached peak levels on the 7th day after injury. More importantly, this effect was abolished by Meox1 knockdown with shRNA. The enhanced expression of SDF-1α after vascular injury was associated with the markedly enhanced expression levels of Sca1+ progenitor cell, and these levels were relatively synchronously increased within neointima by the 7th day after vascular injury. These special effects were abolished by the knockdown of Meox1 with shRNA and inhibition of CXCR4 by its inhibitor, AMD3100. Finally, Meox1 concurrently regulated SDF-1α expressions in VSMC via activating CDC42, and CDC42 inhibition abolished these effects by its inhibitor, ZCL278. Also, Meox1 was involved in activation of the CXCR4 expression of Sca-1+ progenitor cells by CDC42. CONCLUSIONS: Spatio-temporal model of Meox1 expression regulates theSca-1+progenitor cell migration during the formation of the neointima through the synergistic effect of Rho/CDC42 and SDF-1α/CXCR4.


Assuntos
Proteínas de Homeodomínio/genética , Neointima , Células-Tronco , Fatores de Transcrição/genética , Animais , Lesões das Artérias Carótidas/genética , Movimento Celular , Células Cultivadas , Quimiocina CXCL12/genética , Miócitos de Músculo Liso , Ratos , Receptores CXCR4/genética , Proteína cdc42 de Ligação ao GTP
6.
Appl Environ Microbiol ; 87(17): e0092821, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34190611

RESUMO

Fungi are key components of microbial communities in mangrove wetlands, with important roles in the transformation of nutrients and energy. However, existing studies typically focus on cultivable fungi and seldom on the structure and driving factors of entire fungal communities. The compositions, community assembly, and interaction patterns of mangrove fungal communities on a large scale remain elusive. Here, biogeography, assembly, and co-occurrence patterns of fungal communities in mangroves across eastern to southern China were systematically analyzed by targeting the entire internal transcribed spacer (ITS) region with high-throughput Pacific Biosciences single-molecule real-time sequencing. The analysis revealed a high level of fungal diversity, including a number of basal fungal lineages not previously reported in mangroves, such as Rozellomycota and Chytridiomycota. Beta nearest-taxon index analyses suggested a determinant role of dispersal limitation on fungal community in overall and most individual mangroves, with support from the strong distance-decay patterns of community similarity. Further, nonmetric multidimensional scaling analyses revealed similar biogeographies of dominant and rare fungal communities. A minor role of environmental selection on the fungal community was noted, with geographical location and sediment depth as crucial factors driving the distribution of both, the dominant and rare taxa. Finally, network analysis revealed high modularized co-occurrence patterns of fungal community in mangrove sediments, and the keystone taxa might play important roles in microbial interactions and ecological functions. The investigation expands our understanding of biogeography, assembly patterns, driving factors, and co-occurrence relationships of mangrove fungi and will spur the further functional exploration and protection of fungal resources in mangroves. IMPORTANCE As key components of microbial community in mangroves, fungi have important ecological functions. However, the fungal community in mangroves on a large scale is generally elusive, and mangroves are declining rapidly due to climate change and anthropogenic activities. This work provides an overview of fungal community structure and biogeography in mangrove wetlands along a >9,000-km coastline across eastern to southern China. Our study observed a high number of basal fungal lineages, such as Rozellomycota and Chytridiomycota, in mangrove sediments. In addition, our results highlight a crucial role of dispersal limitation and a minor role of environmental selections on fungal communities in mangrove sediments. These novel findings add important knowledge about the structure, assembly processes, and driving factors of fungal communities in mangrove sediments.


Assuntos
Fungos/isolamento & purificação , Sedimentos Geológicos/microbiologia , Micobioma , Fungos/classificação , Fungos/genética , Filogenia , Áreas Alagadas
7.
BMC Infect Dis ; 21(1): 565, 2021 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-34120601

RESUMO

BACKGROUND: Rhodococcus kroppenstedtii is an aerobic, gram-positive bacterium firstly identified in the environment, which has not been reported in human-related infection. Herein, we reported the first case of peritoneal dialysis (PD)-associated peritonitis caused by R. kroppenstedtii which was identified by whole genome sequencing. CASE PRESENTATION: A 69-year-old man was admitted to hospital with abdominal pain and fever. Over the last 2 years, he had been undergoing continuous ambulatory peritoneal dialysis (CAPD) due to end-stage renal disease. Clinical symptom and sign in combination with laboratory examinations supported the clinical diagnosis of PD-associated peritonitis. Thus, ceftizoxime and teicoplanin were empirically used after PD effluent was collected for bacterial culture. A gram-positive bacterium was found from the PD effluent culture, which could not be identified by either Vitek 2 Compact ANC card or matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The strain was finally confirmed to be R. kroppenstedtii by whole genome sequencing (WGS) through the average nucleotide identity (ANI) analysis. With a continuous treatment with teicoplanin and imipenem for 15 days and intraperitoneal catheter removed, the infection symptom was improved evidenced by a normal body temperature, also with white blood cell count (WBC), procalcitonin (PCT) and C-reactive protein (CRP) dropped to normal levels. Peritoneal dialysis effluent culture showed a negative result. Then, hemodialysis and arteriovenous fistula angioplasty were performed, but the patient developed a progressive blood pressure loss, accompanied by multiple organ disorder, and died on Feb 25, 2020. CONCLUSIONS: To the best of our knowledge, this is the first time to report a peritoneal dialysis-associated peritonitis caused by R. kroppenstedtii which was identified by average nucleotide identity analysis based on WGS.


Assuntos
Infecções por Actinomycetales/microbiologia , Diálise Peritoneal Ambulatorial Contínua/efeitos adversos , Peritonite/microbiologia , Rhodococcus , Idoso , Proteína C-Reativa/metabolismo , Evolução Fatal , Humanos , Falência Renal Crônica/complicações , Falência Renal Crônica/terapia , Contagem de Leucócitos , Masculino , Peritonite/etiologia
8.
mSystems ; : e0138120, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34128692

RESUMO

Archaea are a major part of Earth's life. They are believed to play important roles in nutrient biogeochemical cycling in the mangrove. However, only a few studies on the archaeal community in mangroves have been reported. In particular, the assembly processes and interaction patterns that impact the archaeal communities in mangroves have not been investigated to date. Here, the biogeography, assembly patterns, and driving factors of archaeal communities in seven representative mangroves across southeastern China were systematically analyzed. The analysis revealed that the archaeal community is more diverse in surface sediments than in subsurface sediments, and more diverse in mangroves at low latitudes than at high latitudes, with Woesearchaeota and Bathyarchaeota as the most diverse and most abundant phyla, respectively. Beta nearest-taxon index analysis suggested a determinant role of homogeneous selection on the overall archaeon community in all mangroves and in each individual mangrove. In addition, the conditionally rare taxon community was strongly shaped by homogeneous selection, while stochastic processes shaped the dominant taxon and always-rare taxon communities. Further, a moderate effect of environmental selection on the archaeal community was noted, with the smallest effect on the always-rare taxon community. Mangrove location, mean annual temperature, and salinity were the major factors that greatly affected the community composition. Finally, network analysis revealed comprehensive cooccurrence relationships in the archaeal community, with a crucial role of Bathyarchaeota. This study expands the understanding of the biogeography, assembly patterns, driving factors, and cooccurrence relationships of the mangrove archaeal community and inspires functional exploration of archaeal resources in mangrove sediments. IMPORTANCE As a key microbial community component with important ecological roles, archaea merit the attention of biologists and ecologists. The mechanisms controlling microbial community diversity, composition, and biogeography are central to microbial ecology but poorly understood. Mangroves are located at the land-ocean interface and are an ideal environment for examining the above questions. We here provided the first-ever overview of archaeal community structure and biogeography in mangroves located along an over-9,000-km coastline of southeastern China. We observed that archaeal diversity in low-latitude mangroves was higher than that in high-latitude mangroves. Furthermore, our data indicated that homogeneous selection strongly controlled the assembly of the overall and conditionally rare taxon communities in mangrove sediments, while the dominant taxon and always-rare taxon communities were mainly controlled by dispersal limitation.

10.
Phytochem Anal ; 2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-33977596

RESUMO

INTRODUCTION: The genus Aster plants have been widely used for thousands of years in the Qinghai-Tibetan Plateau for the clearing of heat, detoxification, and the treatment of seasonal pandemic diseases. Although the presence of several flavonoid compounds in Aster has been reported by previous studies, the diversity of secondary metabolites within and among species is relatively unknown. OBJECTIVE: The metabolite profile of one Aster species was systematically compared with those of other taxa to find potential chemotaxonomic markers, delimit species, and assess chemodiversity. METHOD: Samples of the above-ground parts of 11 Aster species were collected and their metabolites were analysed by ultra-high performance liquid chromatography with photodiode array detection and quadrupole time-of-flight tandem mass spectrometry. Unsupervised principal component analysis, supervised orthogonal partial least-squares discriminant analysis, heatmap analysis, and hierarchical cluster analysis were employed to analyse 95 representative samples from 11 Aster species and determine species-specific chemical markers based on a metabolomics database. RESULTS: Six phenolic acids and flavonoids were detected and quantified in all Aster species, suggesting that these compounds may be common constituents in the Aster genus. Metabolite analysis showed terpenoid compounds to be potential chemical markers for interspecies differentiation. Ent-kaurane-type diterpenoid glycosides were the main class of compounds in all Aster species except for A. farreri, which mainly contained oleanane-type pentacyclic triterpenoids. Diterpenoid glycosides were low-content chemotaxonomic markers and were detected for the first time in Aster species from the Qinghai-Tibetan Plateau. CONCLUSION: Chemotaxonomy and metabolomics were used to support the phylogenic relationships of the Aster genus.

11.
Molecules ; 26(8)2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-33924693

RESUMO

As a consequence of recent progression in biomedicine and nanotechnology, nanoparticle-based systems have evolved as a new method with extensive applications in responsive therapy, multimodal imaging, drug delivery and natural product separation. Meanwhile, the magnetic nanoparticulate system has aroused great interest for separation and purification because of its excellent magnetic properties. Phospholipase A2 (PLA2) is a highly expressed regulator to promote the growth of various cancers and is an ideal target to treat cancers. In this study, a novel strategy based on ligand-receptor interactions to discover novel PLA2 inhibitors was established, in which PLA2-functionalized Fe3O4@PLGA-PEG-NH2 magnetic nanoparticles were used as a supporting material combined with high-performance liquid chromatography-mass spectrometry, aiming to accelerate the discovery of novel PLA2 inhibitors from natural sources such as mangrove endophytic fungi. Under the optimized ligand fishing conditions, six target compounds were ultimately fished and identified to be cyclic peptides (1-3) and sterols (4-6), which compounds 1, 2 and 4-6 have well-documented cytotoxicities. Compound 3 exerted better inhibitory effect on A549 cells by experiment. In conclusion, PLA2-functionalized Fe3O4@PLGA-PEG-NH2 magnetic nanoparticles-based ligand fishing provided a feasible, selective and effective platform for the efficient screening and identification of antitumor components from natural products.


Assuntos
Enzimas Imobilizadas/química , Extratos Vegetais/química , Células A549 , Cromatografia Líquida de Alta Pressão , Humanos , Fosfolipases A2/metabolismo , Espectrometria de Massas em Tandem
12.
Science ; 372(6540): 403-408, 2021 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-33888640

RESUMO

The nonlinear scaling of complexity with the increased number of components in integrated photonics is a major obstacle impeding large-scale, phase-locked laser arrays. Here, we develop a higher-dimensional supersymmetry formalism for precise mode control and nonlinear power scaling. Our supersymmetric microlaser arrays feature phase-locked coherence and synchronization of all of the evanescently coupled microring lasers-collectively oscillating in the fundamental transverse supermode-which enables high-radiance, small-divergence, and single-frequency laser emission with a two-orders-of-magnitude enhancement in energy density. We also demonstrate the feasibility of structuring high-radiance vortex laser beams, which enhance the laser performance by taking full advantage of spatial degrees of freedom of light. Our approach provides a route for designing large-scale integrated photonic systems in both classical and quantum regimes.

13.
Materials (Basel) ; 14(6)2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33803948

RESUMO

The requirements of high-strength, wear-resistance and lightweight of brake drums have been continually increasing in recent years and any specific aluminum alloy or particle-reinforced aluminum matrix composites may not satisfy all the demands. Combining dissimilar materials to play their respective advantages is a solution to this problem. In this study, a compound casting method was used to combine solid SiCp/A357 composite and a liquid 7050 aluminum alloy to prepare an aluminum matrix composite with a layered structure. The ProCAST numerical simulation software was used to predict the heat transfer in compound casting process and guide the preheating temperature of the wear-resistant ring in the experiment. An Optical Microscope (OM) and Scanning Electron Microscope (SEM) were used to observe microstructures around the solid-liquid bonding interface, the element distribution and phase component of which were analyzed by Energy Dispersive Spectroscopy (EDS) and mechanical properties were evaluated by microhardness and shear tests. The results showed that the interface of the layered aluminum matrix composite prepared by this method achieved complete metallurgical bonding and a transition zone formed on the solid surface. After T6 heat treatment, the average shear strength of the interface increased from 19.8 MPa to 33.8 MPa.

14.
Anal Biochem ; 623: 114171, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-33775668

RESUMO

Discrimination and detection of specific metal ions that belong to the same metallic element with different valence states in a complex matrix is challenging. In the present work, a fluorescence method using polyvinylpyrrolidone stabilized copper nanocluster (CuNCs@PVP) as a probe for discriminating detection of ferrous (Fe3+) and ferric (Fe2+) ions was developed. The CuNCs@PVP exhibited an excellent selective response to Fe3+ ions in contrast to Fe2+ ions and other metal ions when the pH value of solution was less than 4.0. Furthermore, the fluorescence of the CuNCs@PVP could be more sensitively quenched by Fe2+ ions by virtue of Fenton reaction. The different response of CuNCs@PVP towards Fe3+ and Fe2+ ions under different conditions offered the potential for the discriminating detection of Fe3+ and Fe2+ ions. Based on detailed optimization of detection conditions, an excellent linear relationship between the fluorescence quenching efficiency (F/F0) of the CuNCs@PVP and the concentration of Fe3+ ions over the range of 0.4-20.0 µM and of Fe2+ ions in the range of 0.01-0.4 µM were obtained, respectively. The detection limits for the Fe3+ and Fe2+ ions were 0.14 µM and 0.008 µM, respectively. The developed probe showed good selectivity and presented an alternative strategy for discriminating detection of Fe3+ and Fe2+ ions in complex samples.


Assuntos
Cobre/química , Corantes Fluorescentes/química , Ferro/análise , Nanopartículas Metálicas/química , Espectrometria de Fluorescência/métodos , Cátions/química , Fluorescência , Ferro/química , Limite de Detecção , Povidona/química
15.
Artigo em Inglês | MEDLINE | ID: mdl-33549829

RESUMO

Hydrogen sulfide is a natural, widely distributed, poisonous substance and sulfide: quinone oxidoreductase (SQR) is responsible for oxidizing hydrogen sulfide to less toxic sulfur compounds. The increase of SQR mRNA level is an important mechanism for organisms to adapt to hydrogen sulfide-rich environments. However, its transcriptional regulation mechanism is not very clear. In this study, a mitochondrial 28S ribosomal protein S27 (MRPS27), which has never been reported as a transcription factor, was screened by yeast one-hybrid experiment from the echiuran worm Urechis unicinctus, a benthic organism living in marine sediments. Western blotting indicated that UuMRPS27 contents increased significantly in the nuclear extract of hindgut under exposed to 150 µM sulfide. ChIP and EMSA assays demonstrated that UuMRPS27 did bind to the sqr proximal promoter, the key binding sequence was CTAGAG (+12 to +17 of the promoter) detected by DNase I footprinting assay as well as transient transfection experiments. Furthermore, UuMRPS27, as a transcription activator, exhibited the highest transcription activity compared with other reported sqr transcription factors. Our data revealed for the first time the role of MRPS27 acting as a transcription factor which expanded the understanding of sqr transcriptional regulation in sulfide metabolism mechanism.


Assuntos
Proteínas Mitocondriais/fisiologia , Poliquetos/metabolismo , Quinona Redutases/metabolismo , Proteínas Ribossômicas/fisiologia , Sulfetos/metabolismo , Fatores de Transcrição/fisiologia , Animais , Regulação da Expressão Gênica , Poliquetos/genética , Quinona Redutases/genética , Ativação Transcricional
16.
J Agric Food Chem ; 69(6): 1852-1863, 2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-33550805

RESUMO

Stevia (Stevia rebaudiana Bertoni) possesses substantial value for its unique sweet compounds-steviol glycosides (SGs). In the metabolic glycosylation grid of SGs, SrUGT91D2 has been shown to catalyze formation of 1,2-ß-d-glucoside linkages at the C13- and C19-positions and play a crucial role in the synthesis of SGs, including the formation of stevioside (ST), rebaudioside E (RE), and rebaudioside D (RD). However, the key residues of the SrUGT91D2 enzyme and how SrUGT91D2 affects the accumulation of SGs in S. rebaudiana remain unclear. In the present study, cloning and functional analysis of full-length SrUGT91D2 gene sequences were performed in 10 different S. rebaudiana genotypes with divergent SG compositions. After sequence analysis, it was found that most of the sequences of this gene (more than 50%) in each genotype were consistent with the UGT91D2e_No.5 allele, which has been reported to exert catalytic activity on 1,2-ß-d-glucoside. Moreover, six variants (UGT91D2e_No.5, SrUGT91D2-11-14, SrUGT91D2-110, SrUGT91D2-023, SrUGT91D2-N01, and SrUGT91D2-N04) of this gene were obtained, and their activities were identified. Although there were some differences among these variants, the only type of mutation was partial base substitution at a very low level. In addition, the expression analysis of SrUGT91D2 in each genotype showed that the expression level of the gene was significantly different among genotypes, and a significant positive correlation was found between the content of RD (which was closely influenced by SrUGT91D2) and the expression level of SrUGT91D2 in each genotype (correlation coefficient = 0.91). Thus, it was indicated that SrUGT91D2 was relatively conserved in S. rebaudiana, and the differential effect of SrUGT91D2 on the accumulation of related SGs mainly derived from its expression level. Furthermore, based on homologous modeling and molecular docking analysis, T84, T144, A194, S284, E285, V286, G365, E369, R404, and G409 were predicted to be key residues in the glucosylation of SGs by SrUGT91D2. After site-mutation and enzyme assays, it was confirmed that T84, T144, R404, A194, and G409 are the key residues in the SrUGT91D2 protein, especially T144 and G409. This work provided valuable information for understanding the structure-activity relationship of the SrUGT91D2 protein and the molecular mechanism of SG accumulation in stevia.


Assuntos
Diterpenos do Tipo Caurano , Stevia , Glucosídeos , Glicosídeos , Glicosiltransferases/genética , Simulação de Acoplamento Molecular , Folhas de Planta , Stevia/genética , Difosfato de Uridina
17.
J Chemother ; : 1-10, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33583364

RESUMO

Fatigue was a frequently reported adverse event associated with the use of PARP inhibitors. We performed a systematic review and meta-analysis to fully investigate the fatigue of PARP inhibitors in cancer patients. Databases were searched for randomized controlled trials (RCTs) treated with PARP inhibitors till July 2020. Twenty-nine RCTs and 9479 patients were included. This meta-analysis suggests that the use of PARP inhibitors significantly increase the risk of developing all-grade (RR, 1.25; 95%CI, 1.20-1.31; p < 0.00001; I2 = 48%) and high-grade fatigue (RR, 1.92; 95%CI, 1.51-2.45; p < 0.00001; I2 = 11%). Veliparib was associated with a relatively lower risk of fatigue. Patients with ovarian cancer tend to be associated with a higher risk of fatigue than those with non-ovarian cancer. Longer duration of therapy was associated with a higher risk of all-grade fatigue. Patients receiving PARP inhibitor monotherapy tends to be associated with a higher risk of all-grade fatigue than those receiving combination treatment.

18.
Sci Rep ; 11(1): 3130, 2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33542300

RESUMO

For pre-operative osteoarthritis (OA) patients with varus knee, previous studies showed inconsistent results. Therefore, we conducted this study to better identify the association of Hospital for Special Surgery (HSS) score and mechanical alignment. 44 patients (51 knees) with constitutional varus knee caused by combined deformities (LDFA (lateral distal femoral angle) > 90°and MPTA (medial proximal tibial angle) < 85°)) were selected and analyzed with a mean follow-up period of 14 months after total knee arthroplasty (TKA). From January 2015 to December 2016, patients were collected consecutively after primary TKA. After filtering, fifty-one knees (44patients) were analyzed with a mean follow-up period of 14 months. All patients were divided into two groups based on post-operative hip-knee-ankle (HKA) acute angle: varus mechanical alignment (VMA) group (HKA < - 3°) and neutral mechanical axis (NMA) group (- 3° ≤ HKA ≤ 3°). 30 knees were included in the NMA group, and 21 knees in the VMA group. Comparisons of HSS between NMA group and VMA group were performed. After adjusting for age and Body Mass Index (BMI) confounders, Compared with NMA group, the HSS score in VMA group decreased by 0.81 units (95% CI, - 3.37 to 1.75) p = 0.5370). For pre-operative constitutional varus knee caused by combined deformities in chinese populations, no significant association between post-operative lower limb mechanical alignment and HSS score was found.

19.
Biomed Mater ; 2021 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-33571984

RESUMO

Three-dimensional (3D) printing technology is increasingly being employed in biochemical as well as clinical applications and more importantly in fabrication of microfluidic devices. However, the microfluidic community mainly relies on photolithography for fabrication of a defined mask, which is both tedious and expensive requiring clean room settings as well as limited to the generation of two-dimensional (2D) features. In this work, we 3D printed nanoclay-reinforced Pluronic ink as a sacrificial material, which exhibited shear thinning behavior and superior printability allowing the fabrication of unsupported or overhanging templates of channels with uniform diameter and circular cross-sections. To highlight the potential and effectiveness of the presented approach, we fabricated a human blood vessel-on-a-chip model with curved as well as straight channels. These channels were then lined with Human Umbilical Vein Endothelial cells (HUVECs) and subjected to a dynamic culture for 10 days to explore the effect of shear stress on HUVEC morphology based on the location of HUVECs in the devices. Overall, we presented a highly affordable, useful, and practical approach in fabrication of closed microfluidic channels in PDMS based devices, which holds great potential for numerous applications, such as but not limited to tissue/organ-on-chip, microfluidics, point-of-care devices and drug screening platforms.

20.
Angew Chem Int Ed Engl ; 60(18): 10056-10063, 2021 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-33624367

RESUMO

Oxygen redox in Li-rich oxides may boost the energy density of lithium-ion batteries by incorporating oxygen chemistry in solid cathodes. However, oxygen redox in the bulk usually entangles with voltage hysteresis and oxygen release, resulting in a prolonged controversy in literature on oxygen transformation. Here, we report spectroscopic evidence of peroxo species formed and confined in silicate cathodes amid oxygen redox at high voltage, accompanied by Co2+ /Co3+ redox dominant at low voltage. First-principles calculations reveal that localized electrons on dangling oxygen drive the O-O dimerization. The covalence between the binding cation and the O-O dimer determines the degree of electron transfer in oxygen transformation. Dimerization induces irreversible structural distortion and slow kinetics. But peroxo formation can minimize the voltage drop and volume expansion in cumulative cationic and anionic redox. These findings offer insights into oxygen redox in the bulk for the rational design of high-energy-density cathodes.

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