Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 6.278
Filtrar
1.
Sci Total Environ ; 782: 146824, 2021 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-33839651

RESUMEN

Biochar application into the soils has been reported to have huge carbon sequestration potential, although it remains unclear that how the biochar aging in the soil affects its mechanical properties and soil CO2 and N2O emissions. This work assessed the impact of soil biochar aging on its physicochemical properties, microbiota community in the biochar, and soil CO2 and N2O emissions. Various characterizations (e.g., SEM-EDS, XRD, and FTIR) of fresh and aged biochar indicated that soil minerals accumulated on the biochar during the field aging process, forming organo-mineral complexes and blocking the cracks and channels on the biochar. The measured hardness and compressive strength of aged biochar were significantly higher than those of fresh biochar, consistent with the presence of soil minerals on the aged biochar. The soil CO2 and N2O emissions were significantly decreased after the addition of aged biochar particles, as compared to fresh biochar particles. This was probably because that the improved mechanical properties could inhibit the fragmentation of biochar particles, reducing the release of labile fractions from the biochar and the subsequent CO2 and N2O emissions. Moreover, the presence of CO2-fixing bacteria (e.g., Chloroflexi) and inhibited nitrification and ammonia oxidation in aged biochar particles might also reduce CO2 and N2O emissions. These findings suggest aged biochar particles with improved physical stability to the soil could enhance soil carbon sequestration and greenhouse gas emission reduction.

2.
EBioMedicine ; : 103319, 2021 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-33840632

RESUMEN

BACKGROUND: Host determinants of severe coronavirus disease 2019 include advanced age, comorbidities and male sex. Virologic factors may also be important in determining clinical outcome and transmission rates, but limited patient-level data is available. METHODS: We conducted an observational cohort study at seven public hospitals in Singapore. Clinical and laboratory data were collected and compared between individuals infected with different SARS-CoV-2 clades. Firth's logistic regression was used to examine the association between SARS-CoV-2 clade and development of hypoxia, and quasi-Poisson regression to compare transmission rates. Plasma samples were tested for immune mediator levels and the kinetics of viral replication in cell culture were compared. FINDINGS: 319 patients with PCR-confirmed SARS-CoV-2 infection had clinical and virologic data available for analysis. 29 (9%) were infected with clade S, 90 (28%) with clade L/V, 96 (30%) with clade G (containing D614G variant), and 104 (33%) with other clades 'O' were assigned to lineage B.6. After adjusting for age and other covariates, infections with clade S (adjusted odds ratio (aOR) 0·030 (95% confidence intervals (CI): 0·0002-0·29)) or clade O (B·6) (aOR 0·26 (95% CI 0·064-0·93)) were associated with lower odds of developing hypoxia requiring supplemental oxygen compared with clade L/V. Patients infected with clade L/V had more pronounced systemic inflammation with higher concentrations of pro-inflammatory cytokines, chemokines and growth factors. No significant difference in the severity of clade G infections was observed (aOR 0·95 (95% CI: 0·35-2·52). Though viral loads were significantly higher, there was no evidence of increased transmissibility of clade G, and replicative fitness in cell culture was similar for all clades. INTERPRETATION: Infection with clades L/V was associated with increased severity and more systemic release of pro-inflammatory cytokines. Infection with clade G was not associated with changes in severity, and despite higher viral loads there was no evidence of increased transmissibility.

3.
J Adolesc ; 89: 28-40, 2021 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-33845339

RESUMEN

INTRODUCTION: The risk and protective factors of cyberbullying perpetration have been widely investigated. Less attention is paid to explore the effects of personal and situational factors, internal states, and external states in an integrated framework. This study aims to fill this void by developing an integrated framework to investigate the effects of power imbalance, the online disinhibition effect, internal states, and parental mediation on cyberbullying among Chinese adolescents. METHODS: Multistage cluster random sampling was employed with 1103 adolescents (Mage = 15.3, 52.5% girls) who responded to the questionnaire. Structural equation modeling (SEM) was conducted. RESULTS: Proficiency in technology use was directly related to cyberbullying. Social status among peers was found to be not only directly related to cyberbullying but also to operate through low self-control to predict cyberbullying. The online disinhibition effect did not directly correlate to cyberbullying but operated through moral disengagement and low self-control to predict cyberbullying. Notably, the results showed that physical power was neither directly correlated to cyberbullying nor aligned with moral disengagement or low self-control to predict cyberbullying. The multiple-group comparison analysis revealed that parental mediation moderated the effects of the online disinhibition effect on cyberbullying. However, this study found that parental mediation had no buffering effects when examining the relationships between physical power, social status, technology use, and cyberbullying. CONCLUSIONS: Findings suggest that cyberbullying prevention should consider the effects of both internal states and external factors. The study has provided theoretical and practical implications for understanding and tackling the widespread problem of cyberbullying among adolescents.

4.
Cell Death Dis ; 12(4): 391, 2021 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-33846303

RESUMEN

The biological function of TRIM39, a member of TRIM family, remains largely unexplored in cancer, especially in colorectal cancer (CRC). In this study, we show that TRIM39 is upregulated in tumor tissues compared to adjacent normal tissues and associated with poor prognosis in CRC. Functional studies demonstrate that TRIM39 deficiency restrains CRC progression in vitro and in vivo. Our results further find that TRIM39 is a positive regulator of autophagosome-lysosome fusion. Mechanistically, TRIM39 interacts with Rab7 and promotes its activity via inhibiting its ubiquitination at lysine 191 residue. Depletion of TRIM39 inhibits CRC progression and autophagic flux in a Rab7 activity-dependent manner. Moreover, TRIM39 deficiency suppresses CRC progression through inhibiting autophagic degradation of p53. Thus, our findings uncover the roles as well as the relevant mechanisms of TRIM39 in CRC and establish a functional relationship between autophagy and CRC progression, which may provide promising approaches for the treatment of CRC.

5.
Biol Trace Elem Res ; 2021 Apr 13.
Artículo en Inglés | MEDLINE | ID: mdl-33846929

RESUMEN

Rice and rice products are the main sources of Cd contamination in humans. The total and bioaccessible concentrations of Cd and three divalent nutrients, Mn, Cu, and Zn, in locally grown rice grains from Hunan and Guangdong Provinces in China were investigated. An in vitro physiologically based extraction test method was introduced to evaluate the bioaccessibility of the target metals in the rice grains. The mean concentrations of Cd in the rice grains were 0.245 mg/kg and 0.235 mg/kg from Hunan and Guangdong Provinces, respectively. Large variations were observed in the Cd concentrations, indicating a heterogeneous distribution of Cd contamination throughout the study areas. The bioaccessibility of Cd, Mn, and Zn in the gastrointestinal fractions was significantly lower than that in the gastric fractions. In contrast, the bioaccessibility of Cu at the intestinal phase was detected in the rice grains from both provinces. The correlation analysis showed significant relationships between total Cd concentrations and bioaccessible Cd fractions, indicating that higher total Cd in rice grains always resulted in higher bioaccessible Cd. Consistent correlations in the rice grains were observed between Zn and Mn. However, a lack of correlation was found between Cd and Zn in the current study. Risk assessment according to bioaccessible Cd would significantly reduce the exposure risk to Cd from rice consumption.

6.
Res Vet Sci ; 136: 377-384, 2021 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-33799167

RESUMEN

BACKGROUND: Osteoarthritis is currently one of the most common chronic diseases. As life expectancy increases, its prevalence and incidence are expected to rise. At present, more and more evidences prove the correlation between the complement system and osteoarthritis (OA). This study aims to investigate complement C5's influence on the effect of MK801 on osteoarthritis synovial fibroblasts (OA-SFs). METHODS: We used IL-1b to induce OA-SFs derived from mice to obtain OA-SFs. And we performed RT-PCR and Western Blot assays to evaluate the expression levels of associated mRNA and protein. The alteration of MAC expression on OA-SFs cell membrane was evaluated by immunofluorescence assay. The expression of related inflammatory factors of OA-SFs was evaluated by ELISA experiment. RESULTS: MK801 could significantly inhibit the expression of osteoarthritis (OA) marker factors, such as: membrane attack complex (MAC), tumor necrosis factor-α (TNF-α) and matrix metalloproteinase-13 (MMP13). Meanwhile, MK801 can significantly inhibit the expression of complement C5 (C5) in OA-SFs. Immunofluorescence assay showed that MAC expression on OA-SFs cell membrane was significantly inhibited by MK801. The nucleo-plasmic separation experiment demonstrated that MK801 could significantly inhibit the activation of Nuclear factor-κB (NF-κB) signaling pathway in OA-SFs. Futhermore, koncking down the expression of C5 reversed the inhibition MK801 on the expression of OA-SFs inflammatory factors. CONCLUSIONS: These results illustrated two points: first, MK801 inhibited the generation of MAC and the release of inflammation factors in OA-SFs through C5; second: MK801 inhibited the activation of NF-κB signaling pathway in OA-SFs.

8.
Artículo en Inglés | MEDLINE | ID: mdl-33792289

RESUMEN

Organic-inorganic halide perovskites have excellent intrinsic properties, such as long carrier lifetime, high photoluminescence quantum yield, and high gain, in whispering gallery mode (WGM) cavities by facile vapor self-assembly or solution process, which make them competitive for high-performance microlasers. However, the performance of perovskite-based microlasers is severely limited by the fabrication of microcavities, which results in poor reproducibility and uncontrolled morphology. Herein, we explore a reproducible method which combined thermal co-evaporation with femtosecond (fs) laser direct writing for formamidinium lead iodide (FAPbI3) perovskite polygon-shaped WGM microcavities. The microlasers pumped with the fs laser had a low threshold of 4.0-12.3 µJ/cm2 and narrow full width at half-maximum of 0.62-1.05 nm. Moreover, size- and shape-dependent WGM lasing performances are also investigated systematically. The results prove that FAPbI3 polygonal microcavities can serve as promising WGM lasers and have great potential for practical optoelectronic applications.

9.
Sensors (Basel) ; 21(7)2021 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-33800530

RESUMEN

In smart homes, the computational offloading technology of edge cloud computing (ECC) can effectively deal with the large amount of computation generated by smart devices. In this paper, we propose a computational offloading strategy for minimizing delay based on the back-pressure algorithm (BMDCO) to get the offloading decision and the number of tasks that can be offloaded. Specifically, we first construct a system with multiple local smart device task queues and multiple edge processor task queues. Then, we formulate an offloading strategy to minimize the queue length of tasks in each time slot by minimizing the Lyapunov drift optimization problem, so as to realize the stability of queues and improve the offloading performance. In addition, we give a theoretical analysis on the stability of the BMDCO algorithm by deducing the upper bound of all queues in this system. The simulation results show the stability of the proposed algorithm, and demonstrate that the BMDCO algorithm is superior to other alternatives. Compared with other algorithms, this algorithm can effectively reduce the computation delay.

10.
Artículo en Inglés | MEDLINE | ID: mdl-33834755

RESUMEN

Efficiently assessing the invasive capability of tumor cells is critical both for the research and treatment of cancer. Here, we report a novel method called the electrochemical trans-channel assay for efficient evaluation of tumor cell invasiveness. A bioinspired extracellular matrix degradation model (EDM) has been first fabricated on a porous anodic alumina (PAA) membrane to construct the electrochemical apparatus. Upon contacting the invasive tumor cells, invasive capability can be sensitively evaluated by the degree of EDM impairment, which is recorded by the electrochemical trans-channel ionic currents in a label-free manner. Compared to the most commonly used trans-well migration method, this assay can be accomplished in an efficient way that is significantly faster (20 min) and more convenient. Besides, quantitation can also be realized for monitoring the invasion process, which cannot be achieved by other currently used methods. Our proposed electrochemical trans-channel assay method has shown a synergistic effect for the evaluation of tumor cell invasiveness, providing a promising method for clinical assessment or prognostic applications of tumor metastasis.

11.
Public Health Nutr ; : 1-26, 2021 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-33821782

RESUMEN

OBJECTIVE: To explore the relationship between parameters of sodium and potassium excretion using 24-hour urine sample and Mild cognitive impairment (MCI) in general population. DESIGN: This is a cross-sectional study. SETTING: Community-based general population in Emin China. PARTICIPANTS: Totally 1,147 subjects aged ≥18 years were selected to complete the study, with a multistage proportional random sampling method. Cognitive status was assessed with Mini Mental State Examination (MMSE) questionnaire and timed 24-hour urine specimens were collected. Finally, 561 participants aged ≥35 years with complete urine sample and MMSE data were included for the current analysis and divided into groups by tertiles of 24-hour urinary sodium to potassium ratio (24-h UNa/K) as lowest (T1), middle (T2), and highest (T3) groups. RESULTS: The MMSE score was significantly lower in T3, compared with the T1 group (26.0 vs 25.0, P=0.002) and the prevalent MCI was significantly higher in T3 than in T1 group (11.7% vs 25.8%, P>0.001). In multiple linear regression, 24-UNa/K [ß: -0.184, 95%CI: (-0.319, -0.050), p=0.007] were negatively associated with MMSE score. In multivariable logistic regression, compared with T1 group, 24-h UNa/K in the T2 and T3 group showed 2.01 (95%CI: 1.03-3.93, P=0.041) and 3.38 (95%CI: 1.77-6.44, P<0.001) fold odds for presence of MCI, even after adjustment for confounders. More augmented results were demonstrated in sensitivity analysis by excluding individuals taking anti-hypertensive agents. CONCLUSIONS: Higher 24-h UNa/K is in an independent association with prevalent MCI.

12.
Front Cell Infect Microbiol ; 11: 643968, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33791245

RESUMEN

Thyroid nodules are found in nearly half of the adult population. Accumulating evidence suggests that the gut microbiota plays an important role in thyroid metabolism, yet the association between gut microbiota capacity, thyroid nodules, and thyroid function has not been studied comprehensively. We performed a gut microbiome genome-wide association study in 196 patients with thyroid nodules and 283 controls by using whole-genome shotgun sequencing. We found that participants with high-grade thyroid nodules have decreased number of gut microbial species and gene families compared with those with lower grade nodules and controls. There are also significant alterations in the overall microbial composition in participants with high-grade thyroid nodules. The gut microbiome in participants with high-grade thyroid nodules is characterized by greater amino acid degradation and lower butyrate production. The relative abundances of multiple butyrate producing microbes are reduced in patients with high-grade thyroid nodules and the relative abundances of L-histidine metabolism pathways are associated with thyrotropin-releasing hormone. Our study describes the gut microbiome characteristics in thyroid nodules and a gut-thyroid link and highlight specific gut microbiota as a potential therapeutic target to regulate thyroid metabolism.

13.
Inorg Chem ; 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33794094

RESUMEN

Two novel layered compounds BaCuSi2Pn3 (Pn = P, As) adopting new structure types are reported. As revealed by single-crystal X-ray diffraction, both compounds are composed of unique Cu-Si-Pn layers featuring CuPn3 and Si2Pn6 structural motifs found in other archetypal pnictide materials. The stacking of the isostructural Cu-Si-Pn layers is different for phosphide and arsenide compounds. Synthesis from elements aided by in situ synchrotron powder X-ray diffraction resulted in the obtainment of bulk powders with a minimized amount of admixtures. Experimentally measured physical properties of BaCuSi2As3 unexpectedly showed metal-like behavior at temperatures above 15 K, despite the fact that density functional theory calculations predict a small band gap of 0.4 eV. BaCuSi2As3 exhibits ultralow thermal conductivity, which can be explained by the combination of a layered crystal structure with alternating covalent and ionic bonding, which feature rattling of Cu atoms similar to that in tetrahedrites.

14.
J Natl Cancer Inst ; 2021 Apr 08.
Artículo en Inglés | MEDLINE | ID: mdl-33830214

RESUMEN

BACKGROUND: For nonmetastatic castration-resistant prostate cancer (nmCRPC), three drugs under patent protection-apalutamide, enzalutamide, and darolutamide-were approved based on randomized, placebo-controlled trials; one drug with generic availability-abiraterone acetate-showed efficacy in a single-arm trial and is commonly prescribed. Lacking head-to-head trials, the optimal treatment for nmCRPC is unknown, despite widely varied treatment costs. We compared the efficacy and safety of nmCRPC treatments. METHODS: We searched bibliographic databases, regulatory documents, and trial registries for nmCRPC trials. We included published results and, when available original data. We performed matching-adjusted indirect comparison and network meta-analysis and compared treatments regarding metastasis-free survival (MFS), overall survival (OS), and serious adverse events (SAE). RESULTS: We analyzed five trials with a total of 4,360 participants. Compared with placebo, abiraterone acetate engendered the lowest hazard of metastasis/death (hazard ratio [HR] = 0.22, 95% credible interval [CrI] = 0.12 to 0.41), followed by apalutamide (HR = 0.28, 95% CrI=0.23 to 0.34), enzalutamide (HR = 0.30, 95% CrI=0.25 to 0.36), darolutamide (HR = 0.41, 95% CrI=0.34 to 0.49); darolutamide led to the lowest hazard of death (HR = 0.69, 95% CrI= 0.53 to 0.90), followed by enzalutamide (HR = 0.73, 95% CrI=0.61 to 0.87) and apalutamide (HR = 0.75, 95% CrI=0.59 to 0.95); darolutamide resulted in the lowest odds of SAEs (odds ratio [OR] = 1.32, 95% CrI= 1.02 to 1.70), followed by enzalutamide (OR = 1.43, 95% CrI=1.08 to 1.89), apalutamide (OR = 1.58, 95% CrI=1.23 to 2.03), and abiraterone acetate (OR = 1.94, 95% CrI=1.17 to 3.22). CONCLUSIONS: For nmCRPC, darolutamide offered optimal efficacy and safety among approved drugs, abiraterone acetate may offer comparable MFS benefit with cost-savings from generic availability. Future research is needed to more fully examine abiraterone acetate's benefit.

15.
Arch Oral Biol ; 126: 105116, 2021 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-33831734

RESUMEN

OBJECTIVE: Herein, we aimed to identify biomarkers that affect lymphatic metastasis of oral squamous cell carcinoma (OSCC) through bioinformatic analysis, and clinicopathological and in vitro verifications. DESIGN: The OSCC-related gene expression dataset was retrieved from The Cancer Genome Atlas (TCGA) and analyzed to identify differentially expressed genes (DEGs), which were subjected to pathway analysis. Weighted gene co-expression network analysis (WGCNA) and protein-protein interaction (PPI) network analysis were performed to identify hub genes. Expression of potential biomarkers was examined using quantitative real-time polymerase chain reaction, immunohistochemistry, and western blotting. Statistical analyses were performed to determine the association between biomarker expression and clinicopathological characteristics of patients with OSCC. Effects of selected biomarkers on proliferation, migration, and invasion were evaluated using in vitro assays. RESULTS: For DEGs, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed potential lymphatic metastasis-related biological processes and signaling pathways. Eight hub genes - ALOXE3, CSTA, PLA2G4E, PPL, SPRR1A, SPRR2A, SPRR2D, and SPRR2E, were identified via WGCNA and PPI analyses. CSTA expression was markedly downregulated in primary OSCC tissues, and low CSTA expression significantly correlated with high tumor grade (P =  0.001), nodal metastasis (P =  0.028), and poor overall survival (P <  0.001). CTSA overexpression inhibited OSCC cell migration and invasion in vitro, with little effect on OSCC cell proliferation. CONCLUSIONS: Our study revealed that CSTA is a promising biomarker and therapeutic target with prognostic implications in patients with OSCC. CSTA may play an essential role in OSCC lymphatic metastasis and tumor differentiation.

16.
Eur J Med Chem ; 218: 113401, 2021 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-33831779

RESUMEN

Alzheimer's disease (AD) is the most common progressive neurodegenerative disorder characterized by neuronal loss and cognitive impairment that harshly affect the elderly individuals. Currently, the available anti-AD pharmacological approaches are purely symptomatic to alleviate AD symptoms, and the curative effects of novel anti-AD drugs focused on Aß target are disappointing. Hence, there is a tremendous need to adjust AD therapeutic targets and discover novel anti-AD agents. In AD, mitochondrial dysfunction gradually triggers neuronal death from different aspects and worsens the occurrence and progress of AD. Consequently, it has been proposed that the intervention of impaired mitochondria represents an attractive breakthrough point for AD treatments. Due to chemical diversity, poly-pharmacological activities, few adverse effects and multiple targeting, natural products (NPs) have been identified as a valuable treasure for drug discovery and development. Multiple lines of studies have scientifically proven that NPs display ameliorative benefits in AD treatment in relation to mitochondrial dysfunction. This review surveys the complicated implications for mitochondrial dysregulation and AD, and then summarizes the potentials of NPs and their underlying molecular mechanisms against AD via reducing or improving mitochondrial dysfunction. It is expected that this work may open the window to speed up the development of innovative anti-AD drugs originated from NPs and improve upcoming AD therapeutics.

17.
J Cell Mol Med ; 2021 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-33837638

RESUMEN

Chronic ethanol consumption is a well-established independent risk factor for type 2 diabetes mellitus (T2DM). Recently, increasing studies have confirmed that excessive heavy ethanol exerts direct harmful effect on pancreatic ß-cell mass and function, which may be a mechanism of pancreatic ß-cell failure in T2DM. In this study, we evaluated the effect of Lentinan (LNT), an active ingredient purified from the bodies of Lentinus edodes, on pancreatic ß-cell apoptosis and dysfunction caused by ethanol and the possible mechanisms implicated. Functional studies reveal that LNT attenuates chronic ethanol consumption-induced impaired glucose metabolism in vivo. In addition, LNT ameliorates chronic ethanol consumption-induced ß-cell dysfunction, which is characterized by reduced insulin synthesis, defected insulin secretion and increased cell apoptosis. Furthermore, mechanistic assays suggest that LNT enhances ß-cell antioxidant capacity and ameliorates ethanol-induced oxidative stress by activating Nrf-2 antioxidant pathway. Our results demonstrated that LNT prevents ethanol-induced pancreatic ß-cell dysfunction and apoptosis, and therefore may be a potential pharmacological agent for preventing pancreatic ß-cell failure associated with T2DM and stress-induced diabetes.

18.
J Clin Epidemiol ; 2021 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-33838274

RESUMEN

OBJECTIVE: While several prescription drug-based risk indices have been developed, their design, performance, and application has not previously been synthesized. STUDY DESIGN AND SETTING: We searched Ovid MEDLINE, CINAHL and Embase from inception through March 3, 2020 and included studies that developed or updated a prescription drug-based risk index. Two reviewers independently performed screening and extracted information on data source, study population, cohort sizes, outcomes, study methodology and performance. Predictive performance was evaluated using C statistics for binary outcomes and R2 for continuous outcomes. The PROSPERO ID for this review is CRD42020165498. RESULTS: Of 19,112 articles that were retrieved, 124 were full-text screened and 25 were included, each of which represented a de novo or updated drug-based index. The indices were customized to varied age groups and clinical populations and most commonly evaluated outcomes including mortality (36%), hospitalization (24%) and healthcare costs (24%). C statistics ranged from 0.62 to 0.92 for mortality and 0.59 to 0.72 for hospitalization, while adjusted R2 for healthcare costs ranged from 0.06 to 0.62. Seven of the 25 risk indices included used global drug classification algorithms. CONCLUSIONS: More than two-dozen prescription drug-based risk indices have been developed and they differ significantly in design, performance and application.

19.
J Cell Biol ; 220(6)2021 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-33836043

RESUMEN

The chromosomes in the oocytes of many animals appear to promote bipolar spindle assembly. In Drosophila oocytes, spindle assembly requires the chromosome passenger complex (CPC), which consists of INCENP, Borealin, Survivin, and Aurora B. To determine what recruits the CPC to the chromosomes and its role in spindle assembly, we developed a strategy to manipulate the function and localization of INCENP, which is critical for recruiting the Aurora B kinase. We found that an interaction between Borealin and the chromatin is crucial for the recruitment of the CPC to the chromosomes and is sufficient to build kinetochores and recruit spindle microtubules. HP1 colocalizes with the CPC on the chromosomes and together they move to the spindle microtubules. We propose that the Borealin interaction with HP1 promotes the movement of the CPC from the chromosomes to the microtubules. In addition, within the central spindle, rather than at the centromeres, the CPC and HP1 are required for homologous chromosome bi-orientation.

20.
Metabolites ; 11(3)2021 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-33804103

RESUMEN

Nitrogen fixing-cyanobacteria can significantly improve the economic feasibility of cyanobacterial production processes by eliminating the requirement for reduced nitrogen. Anabaena sp. ATCC 33047 is a marine, heterocyst forming, nitrogen fixing cyanobacteria with a very short doubling time of 3.8 h. We developed a comprehensive genome-scale metabolic (GSM) model, iAnC892, for this organism using annotations and content obtained from multiple databases. iAnC892 describes both the vegetative and heterocyst cell types found in the filaments of Anabaena sp. ATCC 33047. iAnC892 includes 953 unique reactions and accounts for the annotation of 892 genes. Comparison of iAnC892 reaction content with the GSM of Anabaena sp. PCC 7120 revealed that there are 109 reactions including uptake hydrogenase, pyruvate decarboxylase, and pyruvate-formate lyase unique to iAnC892. iAnC892 enabled the analysis of energy production pathways in the heterocyst by allowing the cell specific deactivation of light dependent electron transport chain and glucose-6-phosphate metabolizing pathways. The analysis revealed the importance of light dependent electron transport in generating ATP and NADPH at the required ratio for optimal N2 fixation. When used alongside the strain design algorithm, OptForce, iAnC892 recapitulated several of the experimentally successful genetic intervention strategies that over produced valerolactam and caprolactam precursors.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...