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1.
Sci Rep ; 11(1): 1546, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33452449

RESUMO

This study aimed to develop and validate a novel rabbit fixator made from a thermoplastic mask for awake imaging experiments. When heated in a hot-water bath at 65-70 °C for 2-5 min, the thermoplastic mask became soft and could be molded to fit over the entire body of an anesthetized rabbit (4 ml of 3% pentobarbital sodium solution by intramuscular injection). Twenty rabbits were randomly divided into fixator (n = 10) and anesthesia (n = 10) groups. The animals' vital signs, stress hormones (cortisol and adrenaline), and subjective image quality scores for the computed tomography (CT), positron emission tomography (PET), and magnetic resonance imaging (MRI) scanning were measured and compared. Phantom CT, MRI and PET studies were performed to assess the performance with and without the thermoplastic mask by using image agents at different concentrations or with different radioactivity. The respiration rate (RR), systolic blood pressure (SBP), diastolic blood pressure (DBP), peripheral capillary oxygen saturation (SpO2) and body temperature (T) decreased after anesthesia (all P < 0.05) but did not significantly decrease after fixation (all P > 0.05). The heart rate (HR), cortisol and adrenaline did not significantly decrease after either anesthesia or fixation (all P > 0.05). The subjective image quality scores for the CT and MRI images of the head, thorax, liver, kidney, intestines and pelvis and the subjective image quality scores for the PET images did not significantly differ between the two groups (all P > 0.05). For all examined organs except the muscle, 18F-FDG metabolism was lower after fixation than after anesthesia, and was almost identical of liver between two groups. The phantom study showed that the CT values, standard uptake values and MR T2 signal values did not differ significantly with or without the mask (all P > 0.05). A novel rabbit fixator created using a thermoplastic mask could be used to obtain high-quality images for different imaging modalities in an awake and near-physiological state.

2.
Sci Total Environ ; 768: 144470, 2021 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-33454470

RESUMO

The stable operation of the anaerobic digestion of waste activated sludge (WAS) is threatened by numerous emerging contaminants. Meanwhile, the extensive microplastic pollution increased the environmental exposure risk of plasticizer benzyl butyl phthalate (BBP), the BBP content has reached a substantial level in WAS. However, the effect of BBP on WAS anaerobic digestion is still unknown. Here we show that high-level BBP brings on anaerobic digestion upset. The presence of 10.0 mg/L BBP (in sludge with 17,640 ± 510 mg/L TSS) led to deferred cell lysis, which was confirmed by the results of continuous parallel factor analysis of dissolved organic matter and the liberation of lactate dehydrogenase. Further, the deferred cell rupture was confirmed associate with prophage activation during WAS anaerobic digestion. Besides solubilization, the hydrolysis, acetogenesis and methanogenesis were also affected by the addition of BBP. The long-term effects of BBP revealed that the dominant microbial structure in anaerobic digester was stable, but the abundance of many functional microorganisms was changed, including short chain fatty acid producers and consumers. This work highlights one of the susceptibility mechanisms for WAS anaerobic digestion processes and provides new perspectives for the comprehensive assessment of emerging contaminant's environmental risks.

3.
J Hazard Mater ; 403: 123682, 2021 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-33264880

RESUMO

In this work, the incorporation of Fe-bearing sludge-derived biochar greatly enhanced both biotic and abiotic reduction of nitrobenzene (NB) to aniline, which was attributed to the concomitant microbial dissimilatory iron reduction. Biogenic Fe(II) produced by Geobacter sulfurreducens dominated the anaerobic reduction of NB following the pseudo-first-order kinetic. Besides, the increase of pyrolysis temperature from 600 to 900 ℃ to generate biochar resulted in an accelerated removal rate of NB in Geobacter-biochar combined system. The morphology and structural characterization of biochar with G. sulfurreducens confirmed the formation of conductive bacteria-biochar aggregates. Electrochemical measurements suggested the presence of graphitized domains and quinone-like moieties in biochar as redox-active centers, which might play an important role in accelerating electron transfer for microbial dissimilatory iron reduction and NB degradation. This study provides a feasible way of using Fe-bearing sludge as a valuable feedstock for biochar generation and its application with electrochemically active bacteria for the bioremediation of nitroaromatic compounds-polluted wastewater.

4.
Nanotechnology ; 32(10): 105709, 2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33260168

RESUMO

We investigated the effect of an electric treatment on the wettability of aqueous solution on carbon nanotubes (CNT) and ion transport behaviors in superhydrophobic porous carbon nanotube sponges (CNTS). This electric activation treatment where an electric voltage was applied across highly porous CNT sponge induced an electrowetting effect. This effect significantly reduced interfacial tensions between CNT sidewalls and aqueous liquids. Meanwhile, polar functional groups were also introduced on CNTs. Both electrowetting effect and polar functional groups greatly improved the wettability of aqueous solutions on CNT sidewalls. After the electric treatment, we observed a dramatic increase in the overall rate of ion flow across porous CNT sponges. The formation of solution channels during the electric treatment is responsible for the enhanced ionic transport in porous CNT sponges. The overall rate of ion flow increased with the increases in electric treatment time and voltage. The crucial role of electric treatment parameters in the ion transport provides a new strategy for precisely controlling the ion transport across CNT sponges by tuning electric treatment time or voltage. Importantly, the good wettability of aqueous solution on CNT sidewalls greatly increased the effective surface area of CNT sponges and thus significantly improved the performance of CNTS-based supercapacitors after the electric treatment.

5.
J Hazard Mater ; 402: 123498, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32712366

RESUMO

N-doped nanoporous carbon (NC) with two-dimensional structure derived from Zn-ZIF-L via KCl exfoliation and carbonization at different temperature were prepared for adsorptive removal of tetracycline (TC). Characterizations revealed the effective dopant of N atoms and low degree of graphitization with more defects related to the enhanced adsorption capacity of the NC materials. Benefiting from the huge surface area (2195.57 m2 g-1), high porosity (1.34 cm3 g-1) and accessible sheeting structure, the NC-800 exhibited its fast and efficient adsorption of TC in 60 min. Meantime, the maximum adsorption of TC could reach 347.06 mg g-1. Effects of pH, humic acid (HA) and ionic strength (Na+, Ca2+) were studied along with the interactions among influencing factors investigated by response surface model (RSM). By optimizing experimental conditions from RSM, the adsorption capacity could increase to 427.41 mg g-1. Additionally, electrostatic interaction and hydrogen bond interaction might play a dominating role in adsorption reaction. The NC-800 could maintain a high adsorption level after four cycles. Therefore, the NC-800 with great adsorptive property and reusability could be considered as an effective adsorbent with promising potential in applications for water treatment.

6.
J Colloid Interface Sci ; 581(Pt A): 195-204, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32771731

RESUMO

Compared with the transition metal induced homogeneous catalytic system, the heterogeneous catalytic system based on transition metal-doped metal organic frameworks (MOFs) were stable for the efficient utilization of transition metal and avoiding the metal leaching. The aim of this work is to synthesize Co-doped MIL-53(Al) by one-step solvent thermal method and use it to activate peroxymonosulfate (PMS) to remove tetracycline (TC) in water. The successful synthesis of Co-MIL-53(Al) samples was demonstrated by XDR, SEM and FTIR characterizations. The 25% Co-MIL-53(Al)/PMS system showed the optimal TC removal effect compared to the PMS alone and MIL-53(Al)/PMS system. The catalytic performances of Co-MIL-53(Al)/PMS system in conditions of different pH, co-existing substances and water bodies were investigated. Quenching experiment and electron paramagnetic resonance (EPR) showed that the degradation mechanism by Co-MIL-53(Al) activation PMS was mainly attributed to sulfate radical (SO4•-) and singlet oxygen (1O2) non-radical. The degradation intermediates of TC were also identified and the possible degradation pathways were proposed. Co-MIL-53(Al) showed good activity after four cycles. These findings demonstrated that Co-MIL-53(Al) can be a promising heterogeneous catalyst for activating PMS to degrade TC.

7.
Oral Dis ; 2020 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-33188651

RESUMO

OBJECTIVE: Endoscopically assisted extracapsular dissection through a single incision along the cephaloauricular furrow has been adapted as a method of access for operating on benign parotid gland tumors. However, no study has compared the immune and stress responses after surgery between the endoscopic procedure and conventional open surgery. METHODS: Through a randomized method, 50 patients with benign parotid gland tumors were assigned to undergo either endoscopically assisted extracapsular dissection or open parotidectomy. The postoperative inflammatory changes and hormonal response in the patients were analyzed at serum level during the preoperative period and at 12, 24, and 72 hr after either surgery. RESULTS: Twenty-three patients received an endoscopic procedure, while 27 underwent open surgery. The size of the incision, amount of intraoperative bleeding, volume of drainage, postoperative pain score, and satisfaction with appearance were all improved in the endoscopic procedure group. Additionally, the serum levels of C-reactive protein, interleukin (IL)-6, IL-10, and cortisol were significantly lower in the endoscopy group in comparison with those in the open surgery group. CONCLUSION: Endoscopically assisted extracapsular dissection on patients with benign parotid gland tumors is associated with lower inflammatory changes and hormone responses than open surgery, thereby reducing perioperative pathophysiological disturbance and enhancing recovery after surgery.

8.
FEMS Microbiol Ecol ; 96(11)2020 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-32966565

RESUMO

Antimony mining has resulted in considerable pollution to the soil environment. Although studies on antinomy contamination have been conducted, its effects on vertical soil profiles and depth-resolved microbial communities remain unknown. The current study selected three vertical soil profiles (0-2 m) from the world's largest antimony mining area to characterize the depth-resolved soil microbiota and investigate the effects of mining contamination on microbial adaptation. Results demonstrated that contaminated soil profiles showed distinct depth-resolved effects when compared to uncontaminated soil profiles. As soil depth increased, the concentrations of antimony and arsenic gradually declined in the contaminated soil profiles. Acidobacteria, Chloroflexi, Proteobacteria and Thaumarchaeota were the most variable phyla from surface to deep soil. The co-occurrence networks were loosely connected in surface soil, but obviously recovered and were well-connected in deep soil. The metagenomic results indicated that microbial metabolic potential also changed with soil depth. Genes encoding C metabolism pathways were negatively correlated with antimony and arsenic concentrations. Abundances of arsenic-related genes were enriched by severe contamination, but reduced with soil depth. Overall, soil depth-resolved characteristics are often many meters deep and such effects affected the indigenous microbial communities, as well as their metabolic potential due to different contaminants along vertical depths.

9.
Phys Chem Chem Phys ; 22(37): 21297-21306, 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32935675

RESUMO

The glass transition behaviors of thin polymer films on the sidewalls of carbon nanotubes (CNTs) in CNT sponges (CNTSs) were studied. Due to the extremely large surface area of CNTS, the glass transition temperatures (Tg) of thin polystyrene (PS) and poly(methyl methacrylate) (PMMA) films were measured using a routine experimental method, differential scanning calorimetry (DSC). We thus provide a direct Tg comparison between the thin film and the bulk sample using the same DSC technique. For thin polymer films on the CNT sidewalls, free surface and polymer-substrate interfacial interactions co-exist. It is well-known that polymer chains at the liquid-like free surface tend to have a relatively high mobility, but the mobility in the interfacial layer near the substrate depends strongly on the polymer-substrate interaction strength. Accordingly, we tuned the polymer-substrate interaction strength by introducing an amphiphilic sodiumdodecylsulfate (SDS) molecule layer on the CNT sidewalls. The value and sign of Tg deviation were influenced by the competition between the free surface effect and the interfacial interactions. Strong polymer-substrate interactions led to a decrease in the mobility of polymer chains near the substrate and weak polymer-substrate interactions have little influence on the mobility of polymer chains near the substrate. When the polymer-substrate interactions are strong, both the free surface effect and the polymer-substrate interaction are key factors influencing the glass transition temperature. For thin polymer films having weak interactions with substrates, the free surface effect dominates the glass transition behavior and Tgs shows a large reduction. We also observed a double Tg behavior in the thin PS film and found the thickness of the PS film on the substrate was a deciding factor for controlling the spatial variation of Tg.

10.
Acad Radiol ; 27(10): 1363-1372, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32713715

RESUMO

RATIONALE AND OBJECTIVES: Chest CT is not suitable for critically ill patients with COVID-19 and lung ultrasound (LUS) may play an important role for these patients. In this study, we summarized the findings of LUS and explore the value of semiquantitative LUS scores in evaluation and follow-up of COVID-19 pneumonia. MATERIALS AND METHODS: Retrospectively studied the LUS and chest CT imaging of 128 critically ill patients with COVID-19. The imaging data were reviewed to acquire the LUS and CT scores. The correlation between LUS scores and CT scores were made to evaluate the accuracy of LUS. A cut-off point of LUS score was calculated to distinguish critical-type patients from severe-type patients. LUS follow-up of 72 patients were compared with the gold standard chest CT. RESULTS: The most common LUS features of COVID-19 pneumonia were crowded or coalescent B-lines with multifocal small consolidations in multi-zone. The mean LUS score was 8.1 points in severe-type patients and 15.7 points in critical-type patients (P<0.05). The correlation between LUS scores and CT scores was high (r=0.891, p<0.01) and it was higher in critical-type patients than that in severe-type patients. The LUS score higher than 10.5 points had a 97.4% sensitivity and 75.0% specificity to distinguish critical-type patients. The consistency of LUS and chest CT in follow-up was 0.596, with higher consistency in diagnosis of lesion progression (Kappa values was 0.774). CONCLUSION: Our scoring system provides a more quantitative use of LUS findings and accurate evaluation of lung damage for critically ill patients with COVID-19.


Assuntos
Betacoronavirus , Infecções por Coronavirus , Estado Terminal , Pandemias , Pneumonia Viral , Idoso , Infecções por Coronavirus/diagnóstico por imagem , Feminino , Seguimentos , Humanos , Pulmão , Masculino , Pessoa de Meia-Idade , Pneumonia Viral/diagnóstico por imagem , Estudos Retrospectivos , Ultrassonografia
11.
J Colloid Interface Sci ; 580: 470-479, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32711198

RESUMO

Herein, Mn-doped MIL-53(Fe) were fabricated via one-pot solvothermal method and used for peroxymonosulfate (PMS) activation towards tetracycline (TC) degradation from aqueous solution. The characterizations of SEM, FTIR and XRD were utilized to reveal the morphology and structure of the materials. The results showed that Mn-MIL-53(Fe)-0.3 displayed the optimal catalytic performance, the removal efficiency of TC could reach 93.2%. Moreover, the catalytic activity of Mn-MIL-53(Fe) towards TC under different initial pH values, co-existing anions (Cl-,CO32- and SO42-) and humic acid (HA) were investigated. The results of thermodynamic experiment suggested that the catalytic process was endothermic. In addition, integrated with capture experiments results and the characterization results of electron paramagnetic resonance (EPR), which revealed that SO4·- and HO- were the reactive radicals involving in the reaction. More importantly, the possible activation mechanism was discussed in detail based on the X-ray photoelectron spectroscopy results. The active species were generated by the active sites of Fe(II) and Mn(II) on Mn-MIL-53(Fe) effectively activated PMS. Furthermore, the degradation intermediates and possible degradation pathway were investigated by LC-MS. Finally, the catalyst also showed good performance in actual wastewater and demonstrated good recyclability. The Mn-MIL-53(Fe)/PMS system exhibited a promising application prospect for antibiotic-containing waste water treatment.

12.
Pestic Biochem Physiol ; 167: 104599, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32527443

RESUMO

As an ATP-dependent DNA helicase, RecG can repair DNA replication forks in many organisms. However, knowledge of recG in Bacillus thuringiensis (Bt) is limited. In our previous study, recG was found damaged in Bt LLP29-M19, which was more resistant to ultraviolet light (UV) after exposing Bt LLP29 to UV for 19 generations. To further understand the function of recG in the mechanism of Bt UV resistance, recG was knocked out and recovered with homologous recombination technology in Bt LLP29. Comparing the resistance of the different mutants to UVB, Bt ∆recG-LLP29 lacking recG was found more sensitive to UVB, hydroxyurea (HU) and H2O2 than LLP29 and the complementation strain. To compare the expression level of recG in the Bt strains under different UV treatments, Quantitative Real-time PCR (RT-qPCR) of recG was performed in the tested Bt strains, which showed that the expression level of recG in Bt ∆recG-LLP29 was substantially lower than that in the original strain and complementation strain. Interestingly, when exposed to UV for 20 min, RecG expression in both Bt LLP29 and Bt recG-R was the highest. The unwinding activity of recG in Bt LLP29 and the complementation strain were also found higher than that of the recG knockout strain, Bt ∆recG-LLP29. These results demonstrate that recG is involved with the resistance of Bt to UV. These findings not only enhance the understanding of the Bt UV resistance mechanism, but also provide an important theoretical basis for the application of Bt.


Assuntos
Bacillus thuringiensis , Praguicidas , Proteínas de Bactérias , Peróxido de Hidrogênio , Raios Ultravioleta
13.
Diagn Interv Radiol ; 26(6): 523-530, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32558647

RESUMO

PURPOSE: We aimed to differentiate tuberculous peritonitis (TBP) from peritoneal carcinomatosis (PC) using a visual positron-emission tomography/computed tomography (PET/CT) scoring system based on mesenteric fluorodeoxyglucose (FDG) uptake. METHODS: PET/CT scans from 31 patients with TBP and 92 patients with PC were retrospectively reviewed. A visual PET/CT scoring system for mesenteric FDG uptake was used according to the following characteristics: FDG uptake intensity (low = 0, moderate = 1, high = 2), FDG uptake deposits (uniform = 0, irregular = 1, ascitic = 2), FDG uptake focality (diffuse = 0, segmental = 1, focal = 2), nodularity on the corresponding CT (nonnodular = 0, micronodular = 1, macronodular = 2) and mesenteric lymphadenopathy (absent = 0, lymphadenopathy without FDG uptake = 1, lymphadenopathy with FDG uptake = 2). The FDG uptake intensity, deposits, focality, nodularity and mesenteric lymphadenopathy scores between TBP and PC were compared using chi-square tests. The diagnostic performance of this scoring system for differentiating TBP from PC was analyzed using a receiver operating characteristic (ROC) curve. P < 0.05 was considered statistically significant. RESULTS: Twenty-four patients with TBP (77.4%) and 56 patients with PC (60.9%) had mesenteric FDG uptake (P = 0.095) and were included for evaluation with the visual PET/CT scoring system. PC lesions scored higher than TBP lesions in FDG uptake deposits (P < 0.001), focality (P < 0.001) and nodularity (P < 0.001). No significant differences were observed between PC and TBP lesions in FDG uptake intensity (P = 0.396) and lymphadenopathy (P = 0.074). The total score that combined deposits, focality and nodularity had significant value for differentiating TBP from PC (area under the curve (AUC) = 0.869, P < 0.001), and a cutoff > 1 had a sensitivity (the accuracy for diagnosis of PC) of 80.4% and a specificity (the accuracy for diagnosis of TBP) of 75.0%. CONCLUSION: A visual PET/CT scoring system based on mesenteric FDG uptake performed well in differentiating between TBP and PC.

14.
Chemosphere ; 256: 127141, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32470738

RESUMO

To explore a green, low-cost, and efficient strategy to synthesis reduced graphene oxide (RGO), the process and mechanism of the graphene oxide (GO) reduction by a model electrochemically active bacteria (EAB), Geobacter sulfurreducens PCA, were studied. In this work, up to 1.0 mg mL-1 of GO was reduced by G. sulfurreducens within 0.5-8 days. ID/IG ratio in reduced product was similar to chemically RGO. After microbial reduction, the peak which corresponded to the reflection of graphene oxide (001) disappeared, while another peak considered as graphite spacing (002) appeared. The peak intensity of typical oxygen function groups, such as carboxyl C-O and >O (epoxide) groups, diminished in bacterially induced RGO comparing to initial GO. Besides, we observed the doping of nitrogen and phosphorus elements in bacterially induced RGO. In a good agreement with that, better electrochemical performance was noticed after GO reduction. As confirmed with differential pulse voltammetry (DPV) and cyclic voltammetry (CV) analysis, the maximum value of peak currents of bacterially induced RGO were significantly higher than those of GO. Our results showed the electron transfer at microbial cell/GO interface promoted the GO reduction, suggesting a broader application of EAB in biological mediated production of RGO.


Assuntos
Geobacter/metabolismo , Grafite/química , Produtos Biológicos , Elétrons , Grafite/síntese química , Óxidos
16.
Sci Total Environ ; 724: 138248, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32247117

RESUMO

In this work, we investigated the impact of iron nanoparticle, including magnetite nanoparticles (Fe3O4 NPs) and nanoscale zero-valent iron (nZVI), on the anaerobic digestion (AD) performance. Moreover, the evolutions of antibiotic resistance genes (ARGs), class 1 integrons-integrase (intI1) and potential hosts of ARGs were also investigated. The optimal addition of Fe3O4 NPs and nZVI to promote methane production was 0.5 g/L and 1 g/L, which led to 22.07% and 23.02% increase in methane yield, respectively. The degradation rate of organic matter was also enhanced with the addition of Fe3O4 NPs or nZVI. The results of high-throughput sequencing showed that the reactors with iron NPs exhibited significant differences in microbial community structure, compared to the reactors with the non­iron NPs. Iron NPs have caused the relative abundance of the dominant bacteria (Proteobacteria, Firmicutes and Actinobacteria) generally decreased, while the dominant archaea (Euryarchaeota) increased in AD sludge. Quantitative PCR results revealed that iron NPs accelerated the reductions in total absolute abundance of ARGs, especially a beta-lactamase resistance encoded gene (blaOXA). Network analysis displayed that the attenuation of ARGs was mainly attributed to the decline of potential hosts (Proteobacteria, Firmicutes and Actinobacteria). Meanwhile, environmental factors (such as pH, soluble chemical oxygen demand and heavy metals) were also strongly correlated with ARGs.


Assuntos
Integrons , Nanopartículas , Anaerobiose , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Genes Bacterianos/efeitos dos fármacos , Integrases/farmacologia , Ferro/farmacologia , Esgotos
17.
Artigo em Inglês | MEDLINE | ID: mdl-32244472

RESUMO

Consumers' food safety risk information-seeking behavior plays a vital role in improving their food quality and safety awareness and preventing food safety risks. Based on the Risk Information Seeking and Processing Model (RISP), this paper empirically analyzes the food safety risk information-seeking intention of consumers in WeChat and influencing factors under the impact of food safety incidents. We use data from 774 WeChat users and apply the Structural Equation Modeling (SEM) approach. We also conduct multigroup analysis with demographic characteristics as moderating variables. The results demonstrated that: (1) Risk perception (p ≤ 0.01) has direct significant positive effects on consumers' intention to seek food safety information. Besides, higher risk perception (p ≤ 0.01) regarding food safety risks will make people feel more anxious and threatened, and then expand the gap between the information they need and the relevant knowledge they actually have (p ≤ 0.1), which will further stimulate them to seek more information (p ≤ 0.05). (2) Informational subjective norms (p ≤ 0.01) can not only directly affect consumers' information-seeking about food safety, but also indirectly affect consumers' intention through information insufficiency (p ≤ 0.01). (3) The more consumers trust the relevant channels (p ≤ 0.01), the stronger their intention to search for food safety risk information. Moreover, the multiple-group analysis also shows that the effects of consumers' gender, age, educational background, and average monthly earnings are different among different groups. Furthermore, implications are put forward for food safety risk communication efforts in China.


Assuntos
Comportamento do Consumidor , Inocuidade dos Alimentos , Comportamento de Busca de Informação , Intenção , Mídias Sociais , China , Feminino , Humanos , Masculino
18.
Waste Manag ; 108: 1-12, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32334329

RESUMO

Insulating strategies are indispensable for laboratory-scale composting reactors, however, current insulation methods interfere with the aerobic fermentation behaviors related to composting. To address this issue, a centre-oriented real-time temperature compensation strategy was designed in this study. Five 9 L reactors (R1-R5) with different insulation strategies were used for the co-composting of dewatered sludge and Phragmites australis and compared. The process performance was assessed by monitoring the temperature, O2 and CO2 emissions, the physical-chemical properties of the composting materials were evaluated by measuring the organic matter (OM), carbon nitrogen ratio (C/N), pH, electrical conductivity (EC), and fluorescence excitation-emission matrix (EEM) spectra. And a 16S rDNA analysis was used to quantify the evolution of bacterial community. The main findings are as follows. Compared with R1 as a control, the insulating strategies can increase the maximum temperature and prolong the thermophilic phase of composting. Comparing R1 and R3 showed that real-time temperature compensation can better restore the real fermentation of the compost. The results showed that R5 had the best composting effect, reaching 69.8 °C, which was 25.1%, 29.7%, 19.3%, and 17.3% higher than R1, R2, R3, and R4, respectively, and remaining in the thermophilic phase for 4.24 d, which is 1.4, 1.5, 1.3, and 0.2 times longer than R1, R2, R3, and R4, respectively. Furthermore, it can significantly reduce the temperature difference between the centre and edge of the reactor, which improved the composting material allocation efficiency and composting process control accuracy, further providing a basis for the actual full-scale composting operation.


Assuntos
Compostagem , Bactérias , Nitrogênio , Esgotos , Solo , Temperatura
19.
Nature ; 580(7801): 106-112, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32238932

RESUMO

Radial glial progenitor cells (RGPs) are the major neural progenitor cells that generate neurons and glia in the developing mammalian cerebral cortex1-4. In RGPs, the centrosome is positioned away from the nucleus at the apical surface of the ventricular zone of the cerebral cortex5-8. However, the molecular basis and precise function of this distinctive subcellular organization of the centrosome are largely unknown. Here we show in mice that anchoring of the centrosome to the apical membrane controls the mechanical properties of cortical RGPs, and consequently their mitotic behaviour and the size and formation of the cortex. The mother centriole in RGPs develops distal appendages that anchor it to the apical membrane. Selective removal of centrosomal protein 83 (CEP83) eliminates these distal appendages and disrupts the anchorage of the centrosome to the apical membrane, resulting in the disorganization of microtubules and stretching and stiffening of the apical membrane. The elimination of CEP83 also activates the mechanically sensitive yes-associated protein (YAP) and promotes the excessive proliferation of RGPs, together with a subsequent overproduction of intermediate progenitor cells, which leads to the formation of an enlarged cortex with abnormal folding. Simultaneous elimination of YAP suppresses the cortical enlargement and folding that is induced by the removal of CEP83. Together, these results indicate a previously unknown role of the centrosome in regulating the mechanical features of neural progenitor cells and the size and configuration of the mammalian cerebral cortex.


Assuntos
Centrossomo/metabolismo , Córtex Cerebral/citologia , Córtex Cerebral/embriologia , Células Ependimogliais/citologia , Células-Tronco Neurais/citologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Proteínas de Ciclo Celular/metabolismo , Membrana Celular/metabolismo , Membrana Celular/patologia , Proliferação de Células , Centríolos/metabolismo , Córtex Cerebral/patologia , Feminino , Masculino , Camundongos , Proteínas Associadas aos Microtúbulos/deficiência , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Microtúbulos/metabolismo , Microtúbulos/patologia , Neurogênese
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