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1.
Nat Commun ; 15(1): 8698, 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39379349

RESUMO

When aiming at the direct use of CO2 for the preparation of advanced/value-added materials, the synthesis of CO2/olefin copolymers is very appealing but challenging. The δ-lactone 3-ethylidene-6-vinyltetrahydro-2H-pyran-2-one (EVP), synthesized by telomerization of CO2 with 1,3-butadiene, is a promising monomer. However, its chemoselective ring-opening polymerization (ROP) is hampered by unfavorable thermodynamics and the competitive polymerization of highly reactive C=C double bonds under usual conditions. Herein, we report the chemoselective ROP of EVP using a phosphazene/urea binary catalyst, affording exclusively a linear unsaturated polyester poly(EVP)ROP, with a molar mass (Mn) up to 16.1 kg·mol-1 and a narrow distribution (Ð < 1.6), which can be fully recycled back to the pristine monomer, thus establishing a monomer-polymer-monomer closed-loop life cycle. In these polyesters, the CO2 content reaches 33 mol% (29 wt%). The reasons for the unexpected chemoselectivity were investigated by Density-functional theory (DFT) calculations. The poly(EVP)ROP features two pendent C=C double bonds per repeating unit, which show distinct reactivity and thus can be properly engaged in sequential functionalizations towards the synthesis of bifunctional polyesters. We disclose here a methodology providing a facile access to bifunctional and recyclable polyesters from readily available feedstocks.

2.
Int J Mol Sci ; 25(19)2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39408894

RESUMO

As an important global food crop, rice is damaged by a variety of piercing-sucking pests. Identifying a broad-spectrum promoter induced by the physical signal of sucking pests and applying it to transgenic breeding to mitigate the damage caused by different sucking pests will significantly improve the efficiency of our breeding. This study compared the transcriptome changes in two rice varieties under needle-wounding stress to investigate their differential responses to mechanical damage. The results showed that the insect-susceptible variety TN1 exhibited more differentially expressed genes (DEGs) and greater changes in expression levels after needle treatment, indicating a more active internal gene regulatory network. GO and KEGG enrichment analysis further revealed that TN1 not only exhibited changes in genes related to the extracellular environment, but also mobilized more genes associated with stress response and defense. By screening the differentially expressed genes, we identified two promoters (P1 and P2) with inducible expression characteristics in both the resistant and susceptible rice varieties. These promoters were able to effectively drive the expression of the insect resistance gene OsLecRK1* and enhance the resistance of transgenic plants against the brown planthopper. This study provides promoter resources for the development of insect-resistant transgenic crops.


Assuntos
Regulação da Expressão Gênica de Plantas , Oryza , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas , Oryza/genética , Oryza/parasitologia , Plantas Geneticamente Modificadas/genética , Animais , Clonagem Molecular/métodos , Hemípteros/genética , Proteínas de Plantas/genética , Transcriptoma , Perfilação da Expressão Gênica
3.
Bioresour Technol ; 386: 129494, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37460018

RESUMO

This study evaluated the functional activity and microbial structure of a pre-denitrification and single-stage partial nitritation/anammox process (DB-SNAP) coupled system for effectively treating swine manure digestate (SMD). At influent ammonium concentrations of (1000 to 1500) mg/L, the pre-denitrification reactor increased the nitrogen removal efficiency (NRE) by 5%, resulting in an average NRE of 96%. The DB-SNAP and nitrogen-limited strategy facilitated the rapid adoption of anammox bacteria (AnAOB) in the SMD, maintaining a high specific rate of 0.3gN/gVSS/d. A high secretion of tightly bound extracellular polymeric substances (76 mg/gVSS to 102 mg/gVSS) promoted micro-granule aggregation and stability. Moreover, Ca. Kuenenia, an AnAOB genus, was highly enriched from 21% to (27 to 30) %, whereas Nitrospira, a nitrite-oxidizing bacteria, was significantly suppressed to (0 to 0.05) %. These findings will provide valuable guidance in implementing the anammox process in swine wastewater treatment.


Assuntos
Compostos de Amônio , Desnitrificação , Animais , Suínos , Esterco , Nitrogênio , Oxidação Anaeróbia da Amônia , Reatores Biológicos/microbiologia , Oxirredução , Bactérias , Esgotos
4.
BMC Geriatr ; 23(1): 281, 2023 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-37165340

RESUMO

BACKGROUND: Dietary-induced inflammation is potentially associated with sarcopenia. Nevertheless, few studies have investigated the structure of the inflammatory diet and its correlation with muscle function and performance in both the upper and lower limbs. This study was performed to explore the association of the dietary inflammatory index (DII) with sarcopenia and its diagnostic parameters. METHODS: We conducted a cross-sectional survey on a sample of 515 Chinese community-dwelling older adults selected through multistage cluster sampling from three districts in Shanghai. DII scores were calculated using a validated food frequency questionnaire. Sarcopenia and its diagnostic parameters were determined based on the definition set by the Asian Working Group on Sarcopenia (AWGS). RESULTS: The mean age of study participants was 71.31 ± 4.71 years. The prevalence of sarcopenia in the cohort was 12.4%. Older adults in the highest DII quartile had a 3.339 times increased risk of sarcopenia compared to those in the lowest quartile (OR Quartile4vs1:3.339, 95%CI: 1.232, 9.052, p-trend: 0.004) after adjusting for confounding factors. Additionally, a more pro-inflammatory diet was associated with lower appendicular skeletal muscle index (ASMI) (OR Quartile4vs1: 3.005, 95%CI: 1.275, 7.318, p-trend: 0.005), a higher 5-times sit-stand test time score (OR Quartile4vs1: 4.942, 95%CI: 1.745, 13.993, p-trend: 0.005), and lower gait speed (OR Quartile4vs1: 2.392, 95%CI: 1.104, 5.185, p-trend: 0.041) after adjusting for confounding factors. However, there was no significant association between DII, handgrip strength, and Short Physical Performance Battery (SPPB) score in either the unadjusted or adjusted model. CONCLUSION: This study found that the association between consuming a more pro-inflammatory diet and sarcopenia in Chinese community-dwelling older adults was mainly due to underlying low intakes of dietary energy, protein, and anti-inflammatory foods, and not due to the high intake of pro-inflammatory foods. Meanwhile, DII was more highly correlated with lower limb muscle strength and performance compared to upper limb muscle strength.


Assuntos
Sarcopenia , Idoso , Humanos , China , Estudos Transversais , Dieta/efeitos adversos , População do Leste Asiático , Força da Mão , Sarcopenia/diagnóstico , Sarcopenia/epidemiologia , Vida Independente
5.
J Microbiol Biotechnol ; 33(7): 973-979, 2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-37100763

RESUMO

Lycopene is a carotenoid widely used as a food and feed supplement due to its antioxidant, anti-inflammatory, and anti-cancer functions. Various metabolic engineering strategies have been implemented for high lycopene production in Escherichia coli, and for this purpose it was essential to select and develop an E. coli strain with the highest potency. In this study, we evaluated 16 E. coli strains to determine the best lycopene production host by introducing a lycopene biosynthetic pathway (crtE, crtB, and crtI genes cloned from Deinococcus wulumuqiensis R12 and dxs, dxr, ispA, and idi genes cloned from E. coli). The 16 lycopene strain titers diverged from 0 to 0.141 g/l, with MG1655 demonstrating the highest titer (0.141 g/l), while the SURE and W strains expressed the lowest (0 g/l) in an LB medium. When a 2 × YTg medium replaced the MG1655 culture medium, the titer further escalated to 1.595 g/l. These results substantiate that strain selection is vital in metabolic engineering, and further, that MG1655 is a potent host for producing lycopene and other carotenoids with the same lycopene biosynthetic pathway.


Assuntos
Carotenoides , Escherichia coli , Licopeno/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Carotenoides/metabolismo , Antioxidantes/metabolismo , Engenharia Metabólica
6.
Front Nutr ; 10: 1104255, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37081917

RESUMO

Background: Some studies have shown that a pro-inflammatory diet may be associated with cognitive function, but their conclusions have varied considerably. We here present a meta-analysis of the current published literature on DII score and its association with cognitive health. Methods: In this meta-analysis, the PubMed, Embase, Web of Science, and Cochrane databases were searched in September 2022. The reported indexes, specifically OR, RR, and ß, were extracted and analyzed using R version 3.1.0. Results: A total of 636 studies in databases were identified, and 12 were included in the meta-analysis. Higher DII was associated with an increased risk of AD and MCI (OR = 1.34; 95% CI = 1.21-1.49). Meanwhile, it may also cause global function impairment (categorical: OR = 1.63; 95% CI = 1.36-1.96) and verbal fluency impairment (continuous: OR = 0.18; 95% IC = 0.08-0.42). But there was no significant association between DII and executive function (categorical: OR = 1.12; 95% IC = 0.84-1.49; continuous: OR = 0.48; 95% IC = 0.19-1.21) or episodic memory (continuous: OR = 0.56; 95% IC = 0.30-1.03). Conclusion: A pro-inflammatory diet is related to AD, MCI, and the functions of some cognitive domains (specifically global function and verbal fluency). However, the current evidence on the role of diet-induced inflammation in different cognitive domains should be supported by further studies in the future.

7.
ACS Appl Mater Interfaces ; 15(10): 13380-13392, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36853974

RESUMO

As an attractive prototype for neuromorphic computing, the difficultly attained three-terminal platforms have specific advantages in implementing the brain-inspired functions. Also, in these devices, the most utilized mechanisms are confined to the electrical gate-controlled ionic migrations, which are sensitive to the device defects and stoichiometric ratio. The resultant memristive responses have fluctuant characteristics, which have adverse influences on the neural emulations. Herein, we designed a specific transistor platform with light-regulated ambipolar memory characteristics. Also, based on its gentle processes of charge trapping, we obtain the impressive memristive performances featured by smooth responses and long-term endurable characteristics. The optoelectronic samples were also fabricated on flexible substrates successfully. Interestingly, based on the optoelectronic signals of the flexible devices, we endow the desirable optical processes with the brain-inspired emulations. We can flexibly emulate the light-inspired learning-memory functions in a synapse and further devise the advanced synapse array. More importantly, through this versatile platform, we investigate the mutual regulation of excitation and inhibition and implement their sensitive-mode transformations and the homeostasis property, which is conducive to ensuring the stability of overall neural activity. Furthermore, our flexible optoelectronic platform achieves high classification accuracy when implemented in artificial neural network simulations. This work demonstrates the advantages of the optoelectronic platform in implementing the significant brain-inspired functions and provides an insight into the future integration of visible sensing in flexible optoelectronic transistor platforms.

8.
Lett Appl Microbiol ; 76(1)2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36688790

RESUMO

Microbially driven Fe(II) oxidation is vital for Fe-cycling processes. In the present study, a novel strain of nitrate-dependent Fe-oxidizing bacteria (FOB) was isolated from the riparian zone sediment of the Hanjiang River, China. It was identified as Comamonas terrigena strain HJ-2. The strain HJ-2 oxidized 2.80 mmol l-1 Fe(II) within 144 h to form Fe(III)/Fe(II) complex on the cell surface using 1.63 mmol l-1 nitrate as an electron acceptor. The formed nitrite from nitrate reduction chemically oxidized Fe(II). Surprisingly, this strain also reduced nitrilotriacetic iron to form 0.5 mmol l-1 Fe(II) in 120 h in anaerobic conditions primarily mediated by the NADH flavin oxidoreductase. Besides, the strain completely reduced 0.18 mmol l-1 nitrobenzene to aniline in 24 days and 15.6 µmol l-1 arsenate to arsenite in 7 days due to the existence of nitro and arsenate reductases. However, the Fe(II) inhibited the reduction of nitrate, nitrobenzene, and arsenate, possibly due to the impeding of transport of the solutes through the membrane or the synthesis of the related enzymes. These results provide new knowledge about the Fe(II)-cycling and the fate of some pollutants in the riparian zone. It also informed that some bacteria have universal functions on elements and contaminants transformation.


Assuntos
Comamonas , Nitratos , Nitratos/metabolismo , Arseniatos/metabolismo , Compostos Férricos/metabolismo , Compostos Ferrosos/metabolismo , Comamonas/metabolismo , Bactérias/metabolismo , Oxirredução
9.
Chemosphere ; 316: 137797, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36634713

RESUMO

Transition metal doped WO3 mixed oxides (named as W-M-O, M = Nb, Fe, Cr, Cu, Ti or Sn, respectively) with high structure stability were synthesized by modified sol-gel method using citric acid as organic crosslinking agent, and were evaluated for catalytic elimination of low-concentration toluene, monochlorobenzene and 1,2-dichloroethance with high toxicity and relatively stable molecule structure, as the typical examples for the pollutants of various volatile organic compounds (VOCs). Results of the structure-property-performance relationship research showed that mesoporous structure and nanocrystalline/amorphous state were formed, and binary metal components were dispersed into each other, which contributed to promoting the metal/metal electron interaction and adjusting the physicochemical properties of mixed metal oxides. The sequence of apparent catalytic activity for toluene degradation was: W-Nb-O>W-Fe-O>W-Cr-O, W-Cu-O>W-Ti-O>W-Sn-O>WO3, and the sequence for monochlorobenzene degradation was: W-Nb-O>W-Fe-O>W-Cr-O, W-Ti-O>W-Cu-O>W-Sn-O>WO3. There existed cooperative catalytic effect: mesopore and surface acid sites of catalysts facilitated adsorption, activation and breakage of the C-X bond, and then redox sites of catalysts promoted deep oxidation of a series of reaction intermediates to transform into CO2 and H2O. Especially, the optimized W-Nb-O catalyst deserved more attention, since it represented remarkable catalytic activity, selectivity and durability for three typical VOCs degradation along with good resistance to water vapor and corrosion of HCl.


Assuntos
Poluentes Ambientais , Elementos de Transição , Óxidos/química , Clorobenzenos , Oxirredução , Metais/química , Catálise , Tolueno/química
10.
Org Lett ; 25(1): 104-108, 2023 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-36583996

RESUMO

An asymmetric linear selective allylic alkylation of vinylaziridines with 3-aryl oxindoles has been developed by using a chiral oxamide-phosphine (COAP-Bn-OMe-p)/palladium complex in methanol, which furnished a wide variety of 3,3-disubstituted oxindole derivatives in good yields with excellent regio- and enantioselectivities.


Assuntos
Paládio , Oxindóis , Paládio/química , Catálise , Estereoisomerismo , Alquilação
11.
Bioresour Technol ; 367: 128229, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36332864

RESUMO

A novel two-stage process comprising pre-denitrification and single-stage partial nitritation/anammox was developed to treat swine manure digestate with a constant nitrogen loading rate of 1.0 gN/L/d. As the influent NH4+-N concentration increased from 500 to 1500 mg/L, a nitrogen removal efficiency of 88 %-96 % and 5-day biochemical oxygen demand removal efficiency of 93 %-97 % were achieved. Owing to the high influent chemical oxygen demand (COD)/nitrates and nitrites (NOX) ratio of 8.2-9.2 and high COD utilization of denitrifying bacteria (DB), the NO2--N and NO3--N removal efficiencies in the denitrification reactor reached 96 %-99 % and 97 %-99 %, respectively. The contribution of anammox bacteria to nitrogen removal was 70.9 %-84.3 %, whereas that of DB was 11.7 %-18.3 %. The contributions of DB and ordinary heterotrophic organisms to COD removal were 19.5 %-49.3 % and 17.9 %-39 %, respectively. This study will help guide the anammox process in swine wastewater treatment.


Assuntos
Desnitrificação , Nitrogênio , Suínos , Animais , Esterco , Reatores Biológicos/microbiologia , Oxidação Anaeróbia da Amônia , Oxirredução , Bactérias , Águas Residuárias/microbiologia , Esgotos
12.
Sci Total Environ ; 857(Pt 2): 159539, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36265633

RESUMO

The anammox-based process has been considered a promising biological nitrogen elimination method for the treatment of nitrogen-rich wastewater ever since its discovery 40 years ago. However, the slow growth rate of anammox bacteria and severe sludge washout result in a long startup period and limit its widespread industrial application. A membrane bioreactor (MBR) is considered an ideal reactor for the operation of the anammox-based process because the membranes allow for 100 % biomass retention. According to a systematic review of the literature, anammox-based MBR is becoming a research hotspot in the field of nitrogen wastewater treatment. The fundamental understanding of anammox-based MBR and its membrane fouling situation is essential for the development and application of anammox-based MBR. In this paper, the application of MBR in different kinds of anammox process are reviewed. The membrane fouling mechanism and strategies to control membrane fouling are also proposed. It is expected that this review will serve as an invaluable guide for future research and in the engineering applications of anammox-based MBR process.


Assuntos
Oxidação Anaeróbia da Amônia , Reatores Biológicos , Reatores Biológicos/microbiologia , Esgotos/microbiologia , Águas Residuárias , Nitrogênio , Membranas Artificiais
13.
Cell Biosci ; 12(1): 198, 2022 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-36476627

RESUMO

BACKGROUND: Disordered lipid metabolism plays an essential role in both the initiation and progression of alcoholic fatty liver disease (AFLD), and fatty acid ß-oxidation is increasingly considered as a crucial factor for controlling lipid metabolism. Hif-2α is a member of the Hif family of nuclear receptors, which take part in regulating hepatic fatty acid ß-oxidation. However, its functional role in AFLD and the underlying mechanisms remain unclear. RESULTS: Hif-2α was upregulated in EtOH-fed mice and EtOH-treated AML-12 cells. Inhibition or silencing of Hif-2α led to increased fatty acid ß-oxidation and BNIP3-dependent mitophagy. Downregulation of Hif-2α activates the PPAR-α/PGC-1α signaling pathway, which is involved in hepatic fatty acid ß-oxidation, by mediating BNIP3-dependent mitophagy, ultimately delaying the progression of AFLD. CONCLUSIONS: Hif-2α induces liver steatosis, which promotes the progression of AFLD. Here, we have described a novel Hif-2α-BNIP3-dependent mitophagy regulatory pathway interconnected with EtOH-induced lipid accumulation, which could be a potential therapeutic target for the prevention and treatment of AFLD.

14.
J Microbiol ; 60(9): 960-967, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35835960

RESUMO

In protein biotechnology, large soluble fusion partners are widely utilized for increased yield and solubility of recombinant proteins. However, the production of additional large fusion partners poses an additional burden to the host, leading to a decreased protein yield. In this study, we identified two highly disordered short peptides that were able to increase the solubility of an artificially engineered aggregation-prone protein, GFP-GFIL4, from 0.6% to 61% (D3-DP00592) and 46% (D4-DP01038) selected from DisProt database. For further confirmation, the peptides were applied to two insoluble E. coli proteins (YagA and YdiU). The peptides also enhanced solubility from 52% to 90% (YagA) and from 27% to 93% (YdiU). Their ability to solubilize recombinant proteins was comparable with strong solubilizing tags, maltose-binding protein (40 kDa) and TrxA (12 kDa), but much smaller (< 7 kDa) in size. For practical application, the two peptides were fused with a restriction enzyme, I-SceI, and they increased I-SceI solubility from 24% up to 75%. The highly disordered peptides did not affect the activity of I-SceI while I-SceI fused with MBP or TrxA displayed no restriction activity. Despite the small size, the highly disordered peptides were able to solubilize recombinant proteins as efficiently as conventional fusion tags and did not interfere with the function of recombinant proteins. Consequently, the identified two highly disordered peptides would have practical utility in protein biotechnology and industry.


Assuntos
Proteínas de Escherichia coli , Escherichia coli , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/metabolismo , Proteínas Ligantes de Maltose/genética , Proteínas Ligantes de Maltose/metabolismo , Peptídeos/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Solubilidade
15.
Small Methods ; 6(8): e2200332, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35689308

RESUMO

Although the high-energy-density lithium sulfur (Li-S) battery has been considered one of the most promising next-generation energy storage technology, the practical applications have been plagued by the sluggish reaction kinetics and the shuttle effect of lithium polysulfides intermediates. Here, to address the above issues, the authors report a novel separator modified by CeO2 -decorated porous carbon nanostructure (CeO2 /KB/PP). Benefiting from the strong polar surface and large specific surface area, (CeO2 -doped Ketjen Black) delivers efficient chemical adsorption toward lithium polysulfides. Moreover, rich oxygen vacancies of CeO2 provide abundant active sites to expedite lithium polysulfides conversion and regulate deposition and nucleation of Li2 S. Taking advantage of these merits, the battery with the CeO2 /KB/PP separator exhibits remarkable electrochemical performance, including low-capacity decay of only 0.06% per cycle over 1000 cycles at 2 C and superior rate capability of 627 mAh g-1 at 3 C. Even with a high sulfur loading of 6.6 mg cm-2 , the battery can achieve a high areal capacity of 3.6 mAh cm-2 after 100 cycles. This work provides a new application of rare-earth-based materials to facilitate Li-S batteries.

16.
Environ Sci Pollut Res Int ; 29(50): 76066-76077, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35665458

RESUMO

Groundwater level fluctuation is a common natural phenomenon that causes alternate changes in oxygen, moisture, and biogeochemical processes in sediments. Microbes are sensitive to these environmental changes. Therefore, a specific microbial community is proposed to form in the groundwater fluctuation zone (GFZ). The vertical distributions of microbial abundance, diversity, and functional microbes and genes in sediment profiles were investigated, focusing on the GFZ, using high-throughput 16S rRNA gene sequencing, qPCR, and the Functional Annotation of Prokaryotic Taxa (FAPROTAX) approach. The relationships between chemical variables and microbial community structure were investigated by redundancy analysis (RDA). Results showed that the microbial abundance and microbial community richness and diversity were higher in the sediments of the GFZ. The nitrate reducers prefer to stay just below the groundwater level in the GFZ. The predominant microbes in the GFZ functioned as nitrifiers and Fe-oxidizers. The specific community in the GFZ is mainly related to NO3- and Fe(III) in the sediment. Consequently, the biochemical processes nitrification and Fe- and Mn-oxidation sequentially happen above the nitrate-reduction zone near the groundwater level in the GFZ. These results provide new knowledge in the biogeochemistry cycle of the GFZ and its disturbance on the vertical distribution and transport of biogenic elements and contaminants.


Assuntos
Água Subterrânea , Microbiota , Compostos Férricos , Água Subterrânea/química , Nitratos , Oxigênio , RNA Ribossômico 16S/genética
17.
Bioresour Technol ; 355: 127199, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35460840

RESUMO

A simultaneous partial nitritation, anammox, denitrification, and COD oxidation (SNADCO) process was used to evaluate the nitrogen and biodegradable organic matter removal of swine manure digestate based on a nitrite limitation and ammonium surplus strategy. As influent ammonium concentration increased from 500 mg/L to 2100 mg/L, the 5 day biochemical oxygen demand (BOD5) maintained at a high removal efficiency of 95.4%. However, nitrogen removal efficiency (NRE) decreased from 90.9% to 68.2% due to the inhibition of AnAOB caused by an ammonium concentration of 2100 mg/L. The contribution of AnAOB to nitrogen removal was 75.6-86.5%, while that of denitrifying bacteria was 4.6-7.0%. In the case of COD removal, the contributions were from ordinary heterotrophic organisms and denitrifying bacteria, at 27.1-64.9% and 11.2-22.1%, respectively. The results of specific bacteria activity tests and microbial analysis showed that a highly efficient synergism between functional microorganisms is essential for the stability of the SNADCO process.


Assuntos
Compostos de Amônio , Nitrogênio , Animais , Bactérias , Reatores Biológicos/microbiologia , Desnitrificação , Esterco , Oxirredução , Esgotos/microbiologia , Suínos , Águas Residuárias/química
18.
Water Res ; 217: 118437, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35447572

RESUMO

Biofilm carriers can avoid microorganism washout while maintaining a high amount of biomass, but are also associated with a long biofilm formation period and biofilm aging. A single stage partial nitritation/anammox process (single stage PN/A) reactor was setup to study the biofilm growth characterization and treatment performance under an NLR of 0.53 to 0.90 gN/L/d over one year. Biofilm growth was divided into three stages: the formation stage, maturation stage and aging stage. The initial biofilm was observed at day 84. A nitrogen removal efficiency of 83.4% was achieved at an NLR of 0.90 gN/L/d during the mature biofilm stage. Starvation, nitrogen gas accumulation and hydroxyapatite formation resulted in biofilm aging. After mechanical stirring treatment, biofilm reactivation was achieved by biofilm re-formation within one month. There is clear potential for phosphorus recovery, as indicated by the 5.24% - 6.29% phosphorus content in the biofilm (similar to the 5%-7% phosphorus content in enhanced biological phosphate removal sludge). The AnAOB genera abundance in the biofilm maintained at a high level of 18.25%-32.31%, while the abundance of AnAOB increased from the initial 4.10% to 13.78% after mechanical stirring treatment in the suspended sludge ensured biofilm reactivation. The results of this study clearly show that mechanical stirring treatment can be used to achieve the biofilm reactivation as the biofilm fills with the hollow cylindrical carrier. This study has potential as a useful reference for the realization of the wide application of the biofilm single stage PN/A process in the future.


Assuntos
Compostos de Amônio , Esgotos , Oxidação Anaeróbia da Amônia , Biofilmes , Reatores Biológicos , Desnitrificação , Nitrogênio , Oxirredução , Fósforo , Águas Residuárias
19.
Front Immunol ; 13: 806825, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35250977

RESUMO

Porphyromonas gingivalis is a Gram-negative pathogenic bacterium associated with chronic periodontitis. The development of a chimeric peptide-based vaccine targeting this pathogen could be highly beneficial in preventing oral bone loss as well as other severe gum diseases. We applied a computational framework to design a multi-epitope-based vaccine candidate against P. gingivalis. The vaccine comprises epitopes from subunit proteins prioritized from the P. gingivalis reference strain (P. gingivalis ATCC 33277) using several reported vaccine properties. Protein-based subunit vaccines were prioritized through genomics techniques. Epitope prediction was performed using immunoinformatic servers and tools. Molecular modeling approaches were used to build a putative three-dimensional structure of the vaccine to understand its interactions with host immune cells through biophysical techniques such as molecular docking simulation studies and binding free energy methods. Genome subtraction identified 18 vaccine targets: six outer-membrane, nine cytoplasmic membrane-, one periplasmic, and two extracellular proteins. These proteins passed different vaccine checks required for the successful development of a vaccine candidate. The shortlisted proteins were subjected to immunoinformatic analysis to map B-cell derived T-cell epitopes, and antigenic, water-soluble, non-toxic, and good binders of DRB1*0101 were selected. The epitopes were then modeled into a multi-epitope peptide vaccine construct (linked epitopes plus adjuvant) to enhance immunogenicity and effectively engage both innate and adaptive immunity. Further, the molecular docking approach was used to determine the binding conformation of the vaccine to TLR2 innate immune receptor. Molecular dynamics simulations and binding free energy calculations of the vaccine-TLR2 complex were performed to highlight key intermolecular binding energies. Findings of this study will be useful for vaccine developers to design an effective vaccine for chronic periodontitis pathogens, specifically P. gingivalis.


Assuntos
Vacinas Bacterianas , Infecções por Bacteroidaceae , Porphyromonas gingivalis , Infecções por Bacteroidaceae/prevenção & controle , Periodontite Crônica/prevenção & controle , Biologia Computacional , Epitopos de Linfócito T , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Porphyromonas gingivalis/imunologia , Receptor 2 Toll-Like , Vacinas de Subunidades Antigênicas
20.
Macromol Rapid Commun ; 43(8): e2100854, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35254691

RESUMO

Photodetectors based on reduced graphene oxide (rGO) have attracted much attention owing to their simple and low-cost fabrication process. However, the aggregation and defects of rGO flakes still limit the performance of rGO photodetectors. Controlling the composition of rGO has become a vital factor for its prospective applications. For example, the interconnection between rGO and polymers for modified morphologies of rGO films leads to an enhanced performance of devices. In this work, a practical approach to engineer surface uniformity and enhance the performance of a photodetector by modifying the rGO film with hydrophilic polymers poly(vinyl alcohol) (PVA) is reported. Compared with the rGO photodetector, the on/off ratio for the PVA/rGO photodetector shows 3.5 times improvement, and the detectivity shows 53% enhancement even when the photodetector is operated at a low bias of 0.3 V. This study provides an effective route to realize PVA/rGO photodetectors with a low-power operation which shows promising opportunities for the future development of green systems.

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