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BACKGROUND: The production of succinic acid (SA) from biomass has attracted worldwide interest. Saccharomyces cerevisiae is preferred for SA production due to its strong tolerance to low pH conditions, ease of genetic manipulation, and extensive application in industrial processes. However, when compared with bacterial producers, the SA titers and productivities achieved by engineered S. cerevisiae strains were relatively low. To develop efficient SA-producing strains, it's necessary to clearly understand how S. cerevisiae cells respond to SA. RESULTS: In this study, we cultivated five S. cerevisiae strains with different genetic backgrounds under different concentrations of SA. Among them, KF7 and NBRC1958 demonstrated high tolerance to SA, whereas NBRC2018 displayed the least tolerance. Therefore, these three strains were chosen to study how S. cerevisiae responds to SA. Under a concentration of 20 g/L SA, only a few differentially expressed genes were observed in three strains. At the higher concentration of 60 g/L SA, the response mechanisms of the three strains diverged notably. For KF7, genes involved in the glyoxylate cycle were significantly downregulated, whereas genes involved in gluconeogenesis, the pentose phosphate pathway, protein folding, and meiosis were significantly upregulated. For NBRC1958, genes related to the biosynthesis of vitamin B6, thiamin, and purine were significantly downregulated, whereas genes related to protein folding, toxin efflux, and cell wall remodeling were significantly upregulated. For NBRC2018, there was a significant upregulation of genes connected to the pentose phosphate pathway, gluconeogenesis, fatty acid utilization, and protein folding, except for the small heat shock protein gene HSP26. Overexpression of HSP26 and HSP42 notably enhanced the cell growth of NBRC1958 both in the presence and absence of SA. CONCLUSIONS: The inherent activities of small heat shock proteins, the levels of acetyl-CoA and the strains' potential capacity to consume SA all seem to affect the responses and tolerances of S. cerevisiae strains to SA. These factors should be taken into consideration when choosing host strains for SA production. This study provides a theoretical basis and identifies potential host strains for the development of robust and efficient SA-producing strains.
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Regulação Fúngica da Expressão Gênica , Saccharomyces cerevisiae , Ácido Succínico , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Ácido Succínico/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , FermentaçãoRESUMO
Fluctuation disturbance of organic loading rate (OLR) is common in actual anaerobic digestion (AD), but its effects on AD of municipal sludge gets little attention. This study investigated the responses of reactor performance and active microbial community in mesophilic and thermophilic AD of municipal sludge before, during and after OLR periodic fluctuation disturbance. The performance of both reactors were similar before and after disturbance although some parameter values changed during the disturbance, which indicated their enough buffer capacity to OLR periodic fluctuation. Different microbial community at RNA level was observed in the two reactors. When the OLR disturbance commenced, the microbial community changed greatly in thermophilic AD. Error and attack tolerance of the microbial network was analyzed in order to learn the response mechanisms to OLR disturbance. The results assisted that the thermophilic microbial community was more vulnerable, but the reactor performance of which could be maintained using the functional redundancy strategy under OLR fluctuation disturbance.
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Microbiota , Esgotos , Anaerobiose , Reatores Biológicos , Metano , TemperaturaRESUMO
AIMS: The aim was to characterize indigenous micro-organisms in oil reservoirs after polymer flooding (RAPF). METHODS: The microbial communities in the crude oil phase (Oil) and in the filter-graded aqueous phases Aqu0.22 (>0.22 µm) and Aqu0.1 (0.1-0.22 µm) were investigated by 16S rRNA gene high-throughput sequencing. RESULTS: Indigenous micro-organisms related to hydrocarbon degradation prevailed in the three phases of each well. However, obvious differences in bacterial compositions were observed amongst the three phases of the same well and amongst the same phase of different wells. The crude oil and Aqu0.22 shared many dominant bacteria. Aqu0.1 contained a unique bacterial community in each well. Most bacteria in Aqu0.1 were affiliated to culturable genera, suggesting that they may adapt to the oil reservoir environment by reduction of cell size. Contrary to the bacterial genera, archaeal genera were similar in the three phases but varied in relative abundances. The observed microbial differences may be driven by specific environmental factors in each oil well. CONCLUSIONS: The results suggest an application potential of microbial enhanced oil recovery (MEOR) technology in RAPF. The crude oil and Aqu0.1 contain many different functional micro-organisms related to hydrocarbon degradation. Both should not be overlooked when investing and exploring the indigenous micro-organisms for MEOR. SIGNIFICANCE AND IMPACT OF THE STUDY: This work facilitates the understanding of microbial community structures in RAPF and provides information for microbial control in oil fields.
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Microbiota , Petróleo , Bactérias/genética , Hidrocarbonetos , Microbiota/genética , Campos de Petróleo e Gás , Polímeros , RNA Ribossômico 16S/genética , ÁguaRESUMO
Objective To prospectively evaluate the correlation between intravoxel incoherent motion (IVIM)-derived parameters and CT perfusion parameters as well as the pathological grade in insulinoma. Methods A total of 55 patients with suspected insulinoma undergoing IVIM and CT perfusion scans were prospectively enrolled. The images were post-processed to obtain IVIM parameters including apparent diffusion coefficient (ADC),diffusion (D),perfusion correlated diffusion (D*),and f,and CT perfusion parameters including blood flow (BF),blood volume (BV),and permeability (PM). The pathological specimens were stained to obtain pathological parameters including the grading,ki-67 index,and the mitotic count. The IVIM derived parameters of normal pancreas including head,body,and tail as well as that of the pancreatic insulinoma were compared. The correlation between IVIM parameters and CT perfusion parameters as well as the pathological parameters was analyzed. Results ADC and D values of pancreatic tail were significantly lower than those of the pancreatic head and neck (all P<0.001). There were significant differences in all IVIM parameters between insulinoma and normal pancreas (all P<0.001). The ADC and f value of the normal pancreas was positively correlated with BF (r=0.437,P=0.003;r=0.357,P=0.010). There is no correlation between the remaining IVIM parameters and the CT perfusion parameters as well as between IVIM parameters and pathological parameters (all P>0.05). Conclusions IVIM parameters differ at different anatomical parts of normal pancreas. IVIM parameters can distinguish normal pancreatic parenchyma from insulinoma. The ADC value is weakly correlated with BF.
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Insulinoma/diagnóstico por imagem , Neoplasias Pancreáticas/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética , Humanos , Movimento (Física) , Reprodutibilidade dos Testes , Tomografia Computadorizada por Raios XRESUMO
It is of utmost importance to construct industrial xylose-fermenting Saccharomyces cerevisiae strains for lignocellulosic bioethanol production. In this study, two xylose isomerase-based industrial S. cerevisiae strains, O7 and P5, were constructed by δ-integration of the xylose isomerase (XI) gene xylA from the fungus Orpinomyces sp. and from the bacterium Prevotella ruminicola, respectively. The xylose consumption of the strains O7 and P5 at 48-h fermentation was 17.71 and 26.10 g/L, respectively, in synthetic medium with xylose as the sole sugar source. Adaptive evolution further improved the xylose fermentation capacity of the two strains to 51.0 and 28.9% in average, respectively. The transcriptomes of these two strains before and after evolution were analyzed using RNA-Seq. The expression levels of the genes involved in cell integrity, non-optimal sugar utilization, and stress response to environment were significantly up-regulated after evolution and did not depend on the origin of xylA; the expression levels of the genes involved in transmembrane transport, rRNA processing, cytoplasmic translation, and other processes were down-regulated. The expression of genes involved in central carbon metabolism was fine-tuned after the evolution. The analysis of transcription factors (TFs) indicated that most of the genes with significant differential expression were regulated by the TFs related to cell division, DNA damage response, or non-optimal carbon source utilization. The results of this study could provide valuable references for the construction of efficient xylose-fermenting XI strains.
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Aldose-Cetose Isomerases/genética , Aldose-Cetose Isomerases/metabolismo , Neocallimastigales/enzimologia , Prevotella ruminicola/enzimologia , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Xilose/metabolismo , Meios de Cultura/química , Fermentação , Perfilação da Expressão Gênica , Engenharia Metabólica , Neocallimastigales/genética , Prevotella ruminicola/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Seleção Genética , Análise de Sequência de RNARESUMO
Production of ethanol from xylose by recombinant Saccharomyces cerevisiae is suboptimal with slow fermentation rate, compared with that from glucose. In this study, a strain-expressing Scheffersomyces stipitis xylose reductase-xylitol dehydrogenase (XR-XDH) pathway was subjected to adaptive evolution on xylose; this approach generated populations with the significantly improved cell growth and ethanol production rate. Mutants were isolated, and the best one was used for sporulation to generate eight stable mutant strains with improved xylose fermentation ability. They were used in a microarray assay to study the molecular basis of the enhanced phenotype. The enriched transcriptional differences among the eight mutant strains and the native strain revealed novel responses to xylose, which likely contributes to the improved xylose utilization. The upregulated vitamin B1 and B6 biosynthesis indicated that thiamine served as an important cofactor in xylose metabolism and may alleviate the redox stress. The increased expression of genes involved in sulfur amino acid biosynthesis and the decreased expression of genes related to Fe(II) transport may alleviate redox stress as well. Meanwhile, it was remarkable that several glucose-repressible genes, including genes of the galactose metabolism, gluconeogenesis, and ethanol catabolism, had a lower expression level after adaptive evolution. Concomitantly, the expression levels of two regulators of the glucose signaling pathway, Rgs2 and Sip4, decreased, indicating a reshaped signaling pathway to xylose after adaptive evolution. Our findings provide new targets for construction of a superior bioethanol producing strain through inverse metabolic engineering.
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Saccharomyces cerevisiae/genética , Transcriptoma/genética , Xilose/metabolismo , Evolução Biológica , Etanol/metabolismo , Saccharomyces cerevisiae/metabolismoRESUMO
A process for production of fuel ethanol from bamboo treated with concentrated sulfuric acid has been previously proposed. To improve efficiency of the process, we tested saccharification with 70 weight% (wt%) sulfuric acid, acid-sugar separation by ion exclusion, addition of nutrients to the ethanol fermentation, and bioconversion of xylose to xylitol. A high efficiency of both sugar recovery (82.5 %) and acid recovery (97.5 %) was achieved in the saccharification process and in the continuous acid-sugar separation using a modified anion exchange resin, respectively. Reduction of the amount of mineral salts added to the saccharified liquid after acid-sugar separation did not negatively affect performance of the continuous ethanol fermentation. The ethanol yield and productivity were 93.7 % and 6 g/l h, respectively, at 35 °C and pH 4.0. And the ethanol yield and productivity were almost the same even at pH 3.5. Moreover, the xylose remaining in the fermented mash was efficiently converted to xylitol in batch fermentation by Candida tropicalis strain 2.1776. These results demonstrate a more efficient process for the production of fuel ethanol from bamboo.
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Bambusa/metabolismo , Etanol/metabolismo , Candida tropicalis/metabolismo , Fermentação , Xilitol/metabolismo , Xilose/metabolismoRESUMO
OBJECTIVE: To compare the image quality of T1WI fat phase,T1WI water phase, short time inversion recovery (STIR) sequence, and diffusion weighted imaging (DWI) sequence in the evaluation of multiple myeloma (MM). METHODS: Totally 20MM patients were enrolled in this study. All patients underwent scanning at coronal T1WI fat phase, coronal T1WI water phase, coronal STIR sequence, and axial DWI sequence. The image quality of the four different sequences was evaluated. The image was divided into seven sections(head and neck, chest, abdomen, pelvis, thigh, leg, and foot), and the signal-to-noise ratio (SNR) of each section was measured at 7 segments (skull, spine, pelvis, humerus, femur, tibia and fibula and ribs) were measured. In addition, 20 active MM lesions were selected, and the contrast-to-noise ratio (CNR) of each scan sequence was calculated. RESULTS: The average image quality scores of T1WI fat phase,T1WI water phase, STIR sequence, and DWI sequence were 4.19 ± 0.70,4.16 ± 0.73,3.89 ± 0.70, and 3.76 ± 0.68, respectively. The image quality at T1-fat phase and T1-water phase were significantly higher than those at STIR (P=0.000 and P=0.001) and DWI sequence (both P=0.000); however, there was no significant difference between T1-fat and T1-water phase (P=0.723)and between STIR and DWI sequence (P=0.167). The SNR of T1WI fat phase was significantly higher than those of the other three sequences (all P=0.000), and there was no significant difference among the other three sequences (all P>0.05). Although the CNR of DWI sequences was slightly higher than those of the other three sequences,there was no significant difference among all of them (all P>0.05). CONCLUSION: Imaging at T1WI fat phase,T1WI water phase, STIR sequence, and DWI sequence has certain advantages,and they should be combined in the diagnosis of MM.
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Mieloma Múltiplo , Meios de Contraste , Imagem de Difusão por Ressonância Magnética , Fêmur , Cabeça , Humanos , Pescoço , Pelve , Razão Sinal-Ruído , Coluna Vertebral , Coxa da Perna , Tórax , ÁguaRESUMO
OBJECTIVE: To evaluate the feasibility of three-dimensional pseudo-continuous arterial spin label (3D pCASL) non-contrast enhanced perfusion imaging applied to head and neck tumors in high-field MR and detect the effects of different postlabeling delay (PLD) time on image quality and the reliability of repeated measurements of tumor blood flow (BF) in different 3D pCASL groups. METHODS: In this prospective study,all the 25 patients received neck 3D pCASL non-contrast enhanced perfusion examinations in a 3.0 T MR system by using an 8-channel head and neck joint coil. Conventional T1-weighted (TIWI) and T2-weighted imaging (T2WI) were performed firstly. Finally,three 3D pCASL with different PLD time [ASL1(PLD1=1525 ms),ASL2 (PLD2=2025 ms), ASL3(PLD3=2525 ms)] were acquired. Patients' perfusion-weighted images acquired from different 3D pCASL sequences underwent the analysis of signal to noise ratio (SNR) and contrast noise ratio (CNR) for tumors. Two observers performed the qualitative assessments on spiral artifacts and vascular artifacts of perfusion-weighted images from different 3D pCASL sequences. Blood flow (BF) of tumors from different 3D pCASL sequences were measured by the two observers respectively for the first time and by observer 2 for the second time. RESULTS: Seventeen enrolled patients (age:50.1 ± 12.7 years,M/F=10:7) with histopathologic. RESULTS: underwent the evaluation of image quality and measurements of BF values. The SNRs and CNRs of ASL1,ASL2, and ASL3 showed a descending trendency. SNRs (P=0.011) and CNRs (P=0.009) of ASL1 were significant higher than those of ASL3. There was no significant difference of scores of spiral artifacts among the three ASL groups (P=0.932). The scores of vascular artifacts of ASL1,ASL2,and ASL3 showed a descending trendency,also. And scores of ASL1 was significant higher than that of ASL3(P=0.000). The intraclass correlation coefficient (ICC) of intre-and intraobserver were high (ICC>0.9). Although the BF values of ASL1,ASL2, and ASL3 showed an ascending trendency,there was no significant difference among the three groups (P=0.977). CONCLUSIONS: The 3D pCASL no-contrast enhanced perfusion MR imaging can be used for head and neck tumor. The image quality of perfusion weighted images and reliability of BF measurements were satisfied. The 3D pCASL series with PLD of 1525 ms and 2025 ms have better image quality than PLD of 2525 ms. And BF values do not show significant statistic difference among the three groups. Therefore, 3D pCASL series with PLD of 1525 ms and 2025 ms are more suitable for the perfusion imaging of head and neck tumors
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Neoplasias de Cabeça e Pescoço , Artefatos , Feminino , Humanos , Aumento da Imagem , Imageamento Tridimensional , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Razão Sinal-Ruído , Marcadores de SpinRESUMO
OBJECTIVE: To investigate the value of diffusion-weighted imaging (DWI) in the differentiation of metastatic lymph nodes from non-metastatic lymph nodes in cervical cancer. METHODS: In 65 patients who underwent lymph node dissection for cervical cancer, conventional MRI and DWI examinations were performed before surgery. Of the 1590 total dissected pelvic lymph nodes, 392 enlarged nodes with a short-axis diameter (S )of 5 mm or greater were included for further analysis. Each of the size-based criteria [i.e., S, long-axis diameter (L), and S/L ratio] and apparent diffusion coefficient(ADC)-based criteria (i.e., ADCmin, ADCmean, rADCmin, rADCmean) were compared between metastatic lymph nodes and non-metastatic lymph nodes. RESULTS: There were statistically significant differences between metastatic and non-metastatic lymph nodes in S, L, S/L ratio, ADCmin, ADCmean, rADCmin, and rADCmean (all P<0.0001). The Az of the ADCmin (0.956) was greater than that of the other ADC-based criteria and all size-based criteria. Using ADCmin=759.0×10(-6) mm(2)/s, the sensitivity and specificity for differentiating metastatic from non-metastatic lymph nodes were 95.2% and 92.1%, respectively. CONCLUSION: DWI, particularly ADCmin, is feasible for differentiating metastatic from non-metastatic pelvic lymph nodes in patients with cervical cancer.
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Imagem de Difusão por Ressonância Magnética , Linfonodos/patologia , Metástase Linfática/diagnóstico , Neoplasias do Colo do Útero/patologia , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Sensibilidade e EspecificidadeRESUMO
To elucidate the mechanism of biochar addition on carbon and nitrogen retention during distilled grain (DGW) composting, this study investigated the losses of carbon and nitrogen and functional genes related to carbon and nitrogen metabolisms between biochar-treated and control composts. The addition of biochar significantly increased carbon and nitrogen retention by 13.5% and 33.8%, respectively. The difference in core carbon metabolism genes indicated that biochar addition inhibited CO2 release and promoted carbon fixation during the later composting phase, leading to improved carbon retention. Nitrogen metabolism analysis indicated that biochar addition suppressed early-phase ammoniation and late-phase denitrification and promoted nitrification and ammonia assimilation during the later stages of composting, thereby preserving nitrogen. During the later composting phase, biochar addition enhanced carbon-nitrogen coupling metabolism activity, leading to the synchronous retention of carbon and nitrogen. These findings elucidate the mechanism of biochar addition on carbon and nitrogen retention during DGW composting.
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Thermophilic semi-continuous composting (TSC) is effective for kitchen waste (KW) treatment, but large amounts of NH3-rich odorous gas are generated. This study proposes a TSC-biofiltration (BF) two-stage process. Compost from the front-end TSC was used as the packing material in the BF to remove NH3 from the exhaust gas. The BF process was effective in removing up to 83.7 % of NH3, and the NH3 content was reduced to < 8 ppm. Seven days of BF improved the quality of the product from TSC by enhancing the germination index to 134.6 %, 36.5 % higher than that in the aerated-only group. Microbial community analysis revealed rapid proliferation and eventual dominance in the BF of members related to compost maturation and the nitrogen cycle from Actinobacteria, Proteobacteria, Chloroflexi, and Bacteroidetes. The results suggest that the TSC-BF two-stage process is effective in reducing NH3 emissions from TSC and improving compost quality.
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Amônia , Compostagem , Fertilizantes , Compostagem/métodos , Filtração/métodos , Eliminação de Resíduos/métodos , Temperatura , Solo/química , Bactérias/metabolismoRESUMO
Anaerobic digestion (AD) is an effective and applicable technology for treating organic wastes to recover bioenergy, but it is limited by various drawbacks, such as long start-up time for establishing a stable process, the toxicity of accumulated volatile fatty acids and ammonia nitrogen to methanogens resulting in extremely low biogas productivities, and a large amount of impurities in biogas for upgrading thereafter with high cost. Microbial electrolysis cell (MEC) is a device developed for electrosynthesis from organic wastes by electroactive microorganisms, but MEC alone is not practical for production at large scales. When AD is integrated with MEC, not only can biogas production be enhanced substantially, but also upgrading of the biogas product performed in situ. In this critical review, the state-of-the-art progress in developing AD-MEC systems is commented, and fundamentals underlying methanogenesis and bioelectrochemical reactions, technological innovations with electrode materials and configurations, designs and applications of AD-MEC systems, and strategies for their enhancement, such as driving the MEC device by electricity that is generated by burning the biogas to improve their energy efficiencies, are specifically addressed. Moreover, perspectives and challenges for the scale up of AD-MEC systems are highlighted for in-depth studies in the future to further improve their performance.
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Fontes de Energia Bioelétrica , Biocombustíveis , Eletrólise , Anaerobiose , Fontes de Energia Bioelétrica/microbiologia , Reatores Biológicos , Metano/metabolismoRESUMO
Continuous thermophilic composting (CTC) is potentially helpful in shortening the composting cycle. However, its universal effectiveness and the microbiological mechanisms involved are unclear. Here, the physicochemical properties and bacterial community dynamics during composting of distilled grain waste in conventional and CTC models were compared. CTC accelerated the organic matter degradation rate (0.2 vs. 0.1 d-1) and shortened the composting cycle (24 vs. 65 d), mainly driven by the synergism of bacterial genera. Microbial analysis revealed that the abundance of Firmicutes was remarkably improved compared to that in conventional composting, and Firmicutes became the primary bacterial phylum (relative abundance >70 %) during the entire CTC process. Moreover, correlation analysis demonstrated that bacterial composition had a remarkable effect on the seed germination index. Therefore, controlling the composting process under continuous thermophilic conditions is beneficial for enhancing composting efficiency and strengthening the cooperation between bacterial genera.
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Compostagem , Solo , Bactérias , Firmicutes , EstercoRESUMO
OBJECTIVE: To evaluate subtraction images acquired with 3D true steady-state free-precession(SSFP)sequence combined with time-spatial labeling inversion pulse(T-SLIP)for selective and non-contrast-enhanced(non-CE)visualization of the portal venous system,and explore the optimization of this protocol. METHODS: Totally 13 healthy volunteers were recruited.Respiratory-triggered 3D true SSFP sequences on a 1.5T MRI system combined with T-SLIP placed on the spleen and mesenteric area were performed.The portographic images were generated from the subtraction between the pulse on and off images.According to the difference in inversion time(TI)of T-SLIP,four image groups group A(TI of 1300 ms),group B(TI of 1100 ms),group C(TI of 900 ms)and group D(TI of 700 ms),were assigned and compared to detect the optimal TI for portography.For quantitative analysis,the signal intensity(SI)of left and right liver lobe,the large vessels as main,right and left portal vein(MPV,RPV and LPV,respectively)and small vessels as branches of segments four(P4),six(P6)and eight(P8)were measured.The relative SI of MPV,RPV and LPV,as well as P4,P6 and P8 were also compared.For qualitative evaluation,the quality score of visualization was also evaluated using a 4-point scale.One-Way ANOVA and LSD test were used for comparison of quantitative data,and Friedman signed rank test was used for comparison of qualitative scores. RESULTS: In 52 sequences of 13 volunteers,the selective visualization of the portal vein was all successfully conducted.Quantitative evaluation showed significant increased SI at the left lobe between C and D groups and A and B groups(comparison of group C to group A and BP=0.004,0.011;comparison of group D to group A and BP=0.001,0.004),while relative SI of LPV of groups C and D were lower than groups A and B(comparison of group C to group A and BP=0.015,0.015;comparison of group D to group A and BP=0.000,0.000).The relative SI of MPV in group D were decreased than groups A(P=0.000),B(P=0.000),and C(P=0.019).There was no significant difference in relative SI of small vessels among four groups(P>0.05).The image score of portal vessels in four groups also showed no differences(P>0.05). CONCLUSIONS: 3D true SSFP scan with T-SLIP enabled selective non-CE visualization of the portal vein with digital subtraction method.A fixed TI of both 1300 and 1100 ms can be preferable.
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Meios de Contraste/administração & dosagem , Imageamento por Ressonância Magnética/métodos , Veia Porta/anatomia & histologia , Adulto , Feminino , Humanos , Angiografia por Ressonância Magnética , Masculino , Adulto JovemRESUMO
This study evaluated the compostability of rice straw as the main feedstock (75 % in dry weight), supplemented with three different nitrogen-rich wastes, namely food waste (FW), dairy manure (DM), and sewage sludge (SS). Organic matter (OM) degradation, maturity and fertility of the end-product, and bacterial community structure during the composting processes were compared. All composting processes generated mature end-product within 51 days. Notably, FW addition was more effective to accelerate rice straw OM degradation and significantly improved end-product fertility with a high yield of Chinese cabbage. The succession of the bacterial community was accelerated with FW supplementation. Genera Geobacillus, Chryseolinea, and Blastocatella were significantly enriched during the composting of rice straw with FW supplementation. Finally, temperature, total nitrogen, moisture, pH, and total carbon were the key factors affecting microorganisms. This study provides a promising alternative method to enhance the disposal of larger amounts of rice straw in a shorter time.
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Compostagem , Oryza , Eliminação de Resíduos , Nitrogênio/metabolismo , Oryza/metabolismo , Solo/química , Bactérias/metabolismo , Esterco/microbiologia , Suplementos Nutricionais , EsgotosRESUMO
To explore an effective decentralized kitchen waste (KW) treatment system, the performance and bacterial community succession of thermophilic semi-continuous composting (TSC) of KW followed by static stacking (SS) was studied. A daily feeding ratio of 10% ensured stable performance of TSC using an integrated automatic reactor; the efficiencies of organic matter degradation and seed germination index (GI) reached 80.88% and 78.51%, respectively. SS for seven days further promoted the quality of the compost by improving the GI to 91.58%. Alpha- and beta-diversity analyses revealed significant differences between the bacterial communities of TSC and SS. Firmicutes, Actinobacteria, Chloroflexi, Gemmatimonadetes, and Myxococcota were dominant during the TSC of KW, whereas the members of Proteobacteria and Bacteroidetes responsible for product maturity rapidly proliferated during the subsequent SS and ultimately dominated the compost with Firmicutes and Actinobacteria. These results provide new perspectives for decentralized KW treatment using TSC for practical applications.
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Compostagem , Solo , Fertilizantes , Bactérias , Firmicutes , Esterco/microbiologiaRESUMO
RATIONALE AND OBJECTIVES: Magnetic resonance imaging (MRI) has good diagnostic performance and causes no radiation damage, making it an ideal tool for the autoimmune pancreatitis (AIP) surveillance. However, its time cost is high. This study aimed to evaluate (1) whether a simplified protocol (SP) of MRI for AIP surveillance provides information equivalent to the comprehensive protocol (CP) and (2) the time cost reductions associated with using an SP. MATERIALS AND METHODS: This retrospective single-institutional study included 40 patients with AIP with at least two contrast-enhanced MRI/magnetic resonance cholangiopancreatography studies. Two radiologists evaluated two imaging sets (CP/SP) per patient, independently. Intra- and inter-observer agreement in the evaluation of the pancreas and extrapancreatic organs involvement using the SP/CP in addition to the time cost differences between the SP and CP were assessed. Intra- and inter-rater reliability were assessed using Cohen's kappa test, intraclass correlations, or the weighted kappa test. The differences in time costs between the CP and SP were compared using the Mann-Whitney U test or Wilcoxon signed-rank test. RESULTS: The SP had strong intra- and inter-observer agreement with the CP in evaluating MRI parameters (κ ï¼ 0.60, moderate to excellent) and disease activity status (κ ï¼ 0.80, all excellent). The overall image acquisition time cost for the SP was 49.2% of the CP. For the two radiologists, the image interpretation time cost of the SP was reduced by approximately 35% and 27% compared to the CP. CONCLUSION: For AIP surveillance, SP MRI provides information consistent with the CP and is less time-consuming.
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The effect of microplastics (MPs) retained in waste activated sludge (WAS) on anaerobic digestion (AD) performance has attracted more and more attention. However, their effect on thermophilic AD remains unclear. Here, the influence of polyvinyl chloride (PVC) MPs on methanogenesis and active microbial communities in mesophilic (37 °C) and thermophilic (55 °C) AD was investigated. The results showed that 1, 5, and 10 mg/L PVC MPs significantly promoted the cumulative methane yield in mesophilic AD by 5.62%, 7.36%, and 8.87%, respectively, while PVC MPs reduced that in thermophilic AD by 13.30%, 18.82%, and 19.99%, respectively. Moreover, propionate accumulation was only detected at the end of thermophilic AD with PVC MPs. Microbial community analysis indicated that PVC MPs in mesophilic AD enriched hydrolytic and acidifying bacteria (Candidatus Competibacter, Lentimicrobium, Romboutsia, etc.) together with acetoclastic methanogens (Methanosarcina, Methanosaeta). By contrast, most carbohydrate-hydrolyzing bacteria, propionate-oxidizing bacterium (Pelotomaculum), and Methanosarcina were inhibited by PVC MPs in thermophilic AD. Network analysis further suggested that PVC MPs significantly changed the relationship of key microorganisms in the AD process. A stronger correlation among the above genera occurred in mesophilic AD, which may promote the methanogenic performance. These results suggested that PVC MPs affected mesophilic and thermophilic AD of WAS via changing microbial activities and interaction.
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Microplásticos , Esgotos , Esgotos/microbiologia , Anaerobiose , Plásticos , Propionatos , Reatores Biológicos , Bactérias , Metano , TemperaturaRESUMO
OBJECTIVE: To investigate the value of magnetic resonance imaging (MRI) in the preoperative assessment of endometrial cancer. METHODS: Ninety-four patients with histopathologically confirmed endometrial carcinoma were retrospectively enrolled in this study. MRI findings were compared with the pathologic findings in all cases. The depth of myometrial invasion and lymph node metastasis were evaluated by T2 weighted imaging (T2WI) combined with contrast enhancement or diffusion weighted imaging (DWI). RESULTS: Among these 94 patients,62 had no or superficial myometrial involvement and 32 cases had deep myometrial involvement. Meanwhile, 24 groups of metastatic lymph nodes and 164 groups of non-metastatic lymph nodes were detected. The accuracy, specificity, sensitivity, negative predictive value, and positive predictive value of T2WI combined with contrast enhancement in discriminating no/superficial myometrial involvement from deep myometrial involvement were 88.3%, 90.3%, 84.4%, 91.8%, and 81.8%, whereas those of T2WI combined with DWI were 81.9%, 87.1%, 71.9%, 85.7%, and 74.2%, respectively. The accuracy, specificity, sensitivity, negative predictive value, and positive predictive value of T2WI combined with contrast enhancement in identifying metastatic lymph nodes were 89.4%, 96.8%, 54.5%, 90.9%, and 78.3%, whereas those of T2WI combined with DWI were 91.5%, 95.5%, 72.7%, 94.3%, and 77.4%, respectively. CONCLUSIONS: T2WI combined with contrast enhancement is superior to T2WI combined with DWI in evaluation of the depth of myometrial invasion. However, DWI is more sensitive in identifying lymph node metastasis than T2WI combined with contrast enhancement.