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1.
Bioresour Technol ; 394: 130232, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38141881

ABSTRACT

Microalgae, known for rapid growth and lipid richness, hold potential in biofuels and high-value biomolecules. The symbiotic link with bacteria is crucial in large-scale open cultures. This study explores algal-bacterial interactions using a symbiotic model, evaluating acid-resistant Lactic acid bacteria (LAB), stress-resilient Bacillus subtilis and Bacillus licheniformis, and various Escherichia coli strains in the Aurantiochytrium sp. SW1 system. It was observed that E. coli SUC significantly enhanced the growth and lipid production of Aurantiochytrium sp. SW1 by increasing enzyme activity (NAD-IDH, NAD-ME, G6PDH) while maintaining sustained succinic acid release. Optimal co-culture conditions included temperature 28 °C, a 1:10 algae-to-bacteria ratio, and pH 8. Under these conditions, Aurantiochytrium sp. SW1 biomass increased 3.17-fold to 27.83 g/L, and total lipid content increased 2.63-fold to 4.87 g/L. These findings have implications for more efficient microalgal lipid production and large-scale cultivation.


Subject(s)
Microalgae , Escherichia coli , Succinic Acid , Biomass , Symbiosis , NAD , Lipids , Biofuels
2.
Medicine (Baltimore) ; 102(51): e36714, 2023 Dec 22.
Article in English | MEDLINE | ID: mdl-38134107

ABSTRACT

BACKGROUND: Nirmatrelvir plus ritonavir (Paxlovid) have been used in the treatment of adult patients with mild-to-moderate coronavirus disease 2019 (COVID-19). This study aimed to evaluate the impact of Paxlovid on in-hospital outcomes and post-COVID-19 condition in Chinese adult patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant. METHODS: This non-randomized clinical controlled trial recruited patients infected with SARS-CoV-2 Omicron variant from the designated hospital for treating COVID-19 between November 5 and November 28, 2022, in Shijiazhuang, China. Participants were administered Paxlovid (300 mg of nirmatrelvir and 100 mg of ritonavir orally) or standard treatment. The primary outcome was the nucleic acid shedding time and post-COVID-19 condition. RESULTS: A total of 320 patients infected with SARS-CoV-2 Omicron variant were included, with mean age of 29.10 ±â€…7.34 years old. Two hundred patients received Paxlovid. Compared to patients in the standard treatment group, those in Paxlovid group had a significantly shorter nucleic acid shedding time (3.26 ±â€…1.80 vs 7.75 ±â€…3.68 days, P < .001), shorter days until negative swab test (1.74 ±â€…1.15 vs 5.33 ±â€…2.91, P < .001), shorter days of first symptoms resolution (4.86 ±â€…1.62 vs 7.45 ±â€…2.63, P < .001), higher in nucleic acid test negative rate within 3 days [138 (70.77%) vs 14 (11.67%), P < .001], higher negative rate within 5 days [174 (89.23%) vs 26 (21.67%), P < .001], negative rate within 7 days [185 (94.87%) vs 78 (65.00%), P < .001], and were less likely to have post-COVID-19 condition [32 (18.60%) vs 30 (31.57%), P = .016]. There was no significant difference in duration of post-COVID-19 condition (43.00 ±â€…26.00 vs 49.00 ±â€…26.34 days, P = .354) between the 2 groups. CONCLUSION: Compared to standard treatment, Paxlovid significantly reduced nucleic acid shedding time, days until negative swab test, and days of first symptoms resolution, as well as improved nucleic acid test negative rate and post-COVID-19 condition.


Subject(s)
COVID-19 , Nucleic Acids , Adult , Humans , Young Adult , SARS-CoV-2 , Ritonavir/therapeutic use , Hospitals , COVID-19 Drug Treatment
3.
Rev Sci Instrum ; 94(10)2023 Oct 01.
Article in English | MEDLINE | ID: mdl-37791858

ABSTRACT

Neutron scattering instruments play an important role in studying the inner structure of materials. A neutron beam monitor is a detector commonly used in a neutron scattering instrument. The detection efficiency for most neutron beam monitors is quite low (10-4-10-6). However, in some experiments with a low neutron flux, such as small angle neutron scattering (SANS) and inelastic neutron scattering experiments, a neutron beam monitor with a higher detection efficiency (∼1% for thermal neutrons) is required to reduce the duration of the experiment. To meet this requirement, a ceramic gas electron multiplier-based neutron beam monitor equipped with a 1 µm 10B4C neutron converter was developed in this study. Its performance was determined both experimentally and in simulations. The detection efficiency in the wavelength range of 1.8-5.5 Å was measured experimentally and was confirmed by the simulation results. An algorithm based on event selection and position reconstruction was developed to improve the spatial resolution to about 1 mm full-width-half-maximum. The wavelength spectrum was measured in beamline 20 (BL20) and agreed well with the results obtained using a commercial monitor. The maximum counting rate was 1.3 MHz. The non-uniformity over the whole 100 × 100 mm2 active area was determined to be 1.4%. Due to the excellent performance of this monitor, it has been used in several neutron instruments, such as the SANS and the High-Energy Direct-Geometry Inelastic Spectrometer instruments in the China spallation neutron source.

4.
Front Microbiol ; 14: 1161983, 2023.
Article in English | MEDLINE | ID: mdl-37275141

ABSTRACT

Microbial diversity is an important indicator of soil fertility and plays an indispensable role in farmland ecosystem sustainability. The short-term effects of fertilization and rhizobium inoculation on soil microbial diversity and community structure have been explored extensively; however, few studies have evaluated their long-term effects. Here, we applied quantitative polymerase chain reaction (qPCR) and amplicon sequencing to characterize the effect of 10-year fertilizer and rhizobium inoculation on bacterial communities in soybean bulk and rhizosphere soils at the flowering-podding and maturity stages. Four treatments were examined: non-fertilization control (CK), phosphorus and potassium fertilization (PK), nitrogen and PK fertilization (PK + N), and PK fertilization and Bradyrhizobium japonicum 5821 (PK + R). Long-term co-application of rhizobium and PK promoted soybean nodule dry weight by 33.94% compared with PK + N, and increased soybean yield by average of 32.25%, 5.90%, and 5.00% compared with CK, PK, and PK + N, respectively. The pH of PK + R was significantly higher than that of PK and PK + N at the flowering-podding stage. The bacterial abundance at the flowering-podding stage was positively correlated with soybean yield, but not at the maturity stage. The significant different class Gemmatimonadetes, and the genera Gemmatimonas, and Ellin6067 in soil at the flowering-podding stage were negatively correlated with soybean yield. However, the bacterial community at class and genus levels at maturity had no significant effect on soybean yield. The key bacterial communities that determine soybean yield were concentrated in the flowering-podding stage, not at maturity stage. Rhizosphere effect, growth period, and treatment synergies resulted in significant differences in soil bacterial community composition. Soil organic matter (OM), total nitrogen (TN), pH, and available phosphorus (AP) were the main variables affecting bacterial community structure. Overall, long-term co-application of rhizobium and fertilizer not only increased soybean yield, but also altered soil bacterial community structure through niche reconstruction and microbial interaction. Rhizobium inoculation plays key role in reducing nitrogen fertilizer application and promoting sustainable agriculture practices.

5.
Helicobacter ; 28(4): e12984, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37186092

ABSTRACT

PURPOSE: To characterize the serum metabolism in patients with Helicobacter pylori-positive and H. pylori-negative gastritis. METHODS: Clinical data and serum gastric function parameters, PGI (pepsinogen I), PGII, PGR (PGI/II), and G-17 (gastrin-17) of 117 patients with chronic gastritis were collected, including 57 H. pylori positive and 60 H. pylori negative subjects. Twenty cases in each group were randomly selected to collect intestinal mucosa specimens and serum samples. The gut microbiota profiles were generated by 16S rRNA gene sequencing, and the serum metabolites were analyzed by a targeted metabolomics approach based on liquid chromatography-mass spectrometry (LC-MS) technology. RESULTS: Altered expression of 20 metabolites, including isovaleric acid, was detected in patients with HPAG. Some taxa of Bacteroides, Fusobacterium, and Prevotella in the gut microbiota showed significant correlations with differentially expressed metabolites between H. pylori positive and H. pylori negative individuals. As a result, an H. pylori-gut microbiota-metabolism (HGM) axis was proposed. CONCLUSION: Helicobacter pylori infection may influence the progression of mucosal diseases and the emergence of other complications in the host by altering the gut microbiota, and thus affecting the host serum metabolism.


Subject(s)
Gastritis , Gastrointestinal Microbiome , Helicobacter Infections , Helicobacter pylori , Humans , Helicobacter Infections/microbiology , RNA, Ribosomal, 16S/genetics , Gastritis/microbiology , Gastric Mucosa/microbiology , Inflammation
6.
Sci Rep ; 13(1): 8234, 2023 05 22.
Article in English | MEDLINE | ID: mdl-37217543

ABSTRACT

Ammonia-oxidizing archaea and bacteria (AOA and AOB, respectively) are important intermediate links in the nitrogen cycle. Apart from the AOA and AOB communities in soil, we further investigated co-occurrence patterns and microbial assembly processes subjected to inorganic and organic fertilizer treatments for over 35 years. The amoA copy numbers and AOA and AOB communities were found to be similar for the CK and organic fertilizer treatments. Inorganic fertilizers decreased the AOA gene copy numbers by 0.75-0.93-fold and increased the AOB gene copy numbers by 1.89-3.32-fold compared to those of the CK treatment. The inorganic fertilizer increased Nitrososphaera and Nitrosospira. The predominant bacteria in organic fertilizer was Nitrosomonadales. Furthermore, the inorganic fertilizer increased the complexity of the co-occurrence pattern of AOA and decreased the complexity pattern of AOB comparing with organic fertilizer. Different fertilizer had an insignificant effect on the microbial assembly process of AOA. However, great difference exists in the AOB community assembly process: deterministic process dominated in organic fertilizer treatment and stochastic processes dominated in inorganic fertilizer treatment, respectively. Redundancy analysis indicated that the soil pH, NO3-N, and available phosphorus contents were the main factors affecting the changes in the AOA and AOB communities. Overall, this findings expanded our knowledge concerning AOA and AOB, and ammonia-oxidizing microorganisms were more disturbed by inorganic fertilizers than organic fertilizers.


Subject(s)
Ammonia , Fertilizers , Fertilizers/analysis , Soil Microbiology , Oxidation-Reduction , Phylogeny , Bacteria/genetics , Archaea/genetics , Soil/chemistry , Fertilization
7.
Life (Basel) ; 13(3)2023 Mar 13.
Article in English | MEDLINE | ID: mdl-36983929

ABSTRACT

Indigenous soil microbial biomass (ISMB) plays a key role in maintaining essential functions and biodiversity of soil health. One of the critical unknowns is how the indigenous microorganisms respond to different fertilizers which is directly related to agricultural production. Therefore, we used Mi-Seq sequencing and network analyses to compare the response of ISMB to biogas residue and chemical fertilizers. The results showed that crop production was profoundly influenced by levels of ISMB present and is further dependent on the strategy of fertilizer application. Higher ISMB primarily manifests through retention of richer microbial abundance, a balanced community structure, and tightened co-occurrence within a certain proportion of Nitrospirae, Rhizophlyctidaceae, and Gemmatimonadetes. Compared to chemical fertilizer, biogas residue resulted in higher production with more strongly linked nodes such as Actinobacteria, Chloroflexi and Gemmatimonadetes. Under the same level of ISMB, the microbial diversity was richer and co-occurrence was tighter when biogas residues were applied compared with chemical fertilizer. In addition, the higher level of ISMB with biogas residue applied had a lower abundance of potential fungal pathogens in both bulk and rhizosphere soil compared with chemical fertilizer. This study provides critical data to understand the influence of ISMB and biogas residue on soil ecological system.

8.
Genes (Basel) ; 13(11)2022 10 22.
Article in English | MEDLINE | ID: mdl-36360159

ABSTRACT

Plant growth-promoting rhizobacteria (PGPR) are widely used to improve soil nutrients and promote plant growth and health. However, the growth-promoting effect of a single PGPR on plants is limited. Here, we evaluated the effect of applying rhizobium Bradyrhizobium japonicum 5038 (R5038) and two PGPR strains, Bacillus aryabhattai MB35-5 (BA) and Paenibacillus mucilaginosus 3016 (PM), alone or in different combinations on the soil properties and rhizosphere bacterial community composition of soybean (Glycine max). Additionally, metagenomic sequencing was performed to elucidate the profile of functional genes. Inoculation with compound microbial inoculant containing R5038 and BA (RB) significantly improved nodule nitrogenase activity and increased soil nitrogen content, and urease activity increased the abundance of the nitrogen cycle genes and Betaproteobacteria and Chitinophagia in the rhizosphere. In the treatment of inoculant-containing R5038 and PM (RP), significant changes were found for the abundance of Deltaproteobacteria and Gemmatimonadetes and the phosphorus cycle genes, and soil available phosphorus and phosphatase activity were increased. The RBP inoculants composed of three strains (R5038, BA and PM) significantly affected soybean biomass and the N and P contents of the rhizosphere. Compared with RB and RP, RBP consistently increased soybean nitrogen content, and dry weight. Overall, these results showed that several PGPR with different functions could be combined into composite bacterial inoculants, which coordinately modulate the rhizosphere microbial community structure and improve soybean growth.


Subject(s)
Bacillus , Bradyrhizobium , Paenibacillus , Bradyrhizobium/genetics , Glycine max , Plant Roots/microbiology , Soil/chemistry , Paenibacillus/genetics , Phosphorus , Nitrogen
9.
Arch Esp Urol ; 75(4): 346-353, 2022 May 28.
Article in English | MEDLINE | ID: mdl-35818915

ABSTRACT

OBJECTIVES: Clear cell renal cell carcinoma (ccRCC) is a type of kidney cancer that has a poor prognosis. microRNA-487a (miR-487a) plays a role in the prognosis of gastric cancer, liver cancer, and other cancers. The purpose of this study is to explore the role of miR-487a in the generation and progression of ccRCC. MATERIALS AND METHODS: The RT-qPCR technology was used to detect the expression levels of miR-487a in ccRCC tissues and cell lines. The association between miR-487a and clinical-pathological characteristics of patients was analyzed using the chi-square test. Kaplan-Meier survival analysis and Cox regression analysis were used to analyze the prognostic significance of miR-487a in ccRCC. CCK-8 and Transwell assays were used to analyze the influences of miR-487a on cell proliferation, migration, and invasion. RESULTS: miR-487a was significantly up-regulated in ccRCC tissues and cell lines. The high expression of miR-487a is related to lymph node metastasis and TNM staging and may be used as an independent prognostic factor related to lower overall survival and disease-free survival rate. Increased expression of miR-487a accelerated the proliferation, migration, and invasion of ccRCC cells. CONCLUSION: The enhanced expression of miR-487a was related to the prognosis of ccRCC, and it also facilitated cell proliferation, migration, and invasion.


Subject(s)
Carcinoma, Renal Cell , Kidney Neoplasms , MicroRNAs , Carcinoma, Renal Cell/genetics , Carcinoma, Renal Cell/pathology , Gene Expression Regulation, Neoplastic , Humans , Kidney Neoplasms/genetics , Kidney Neoplasms/pathology , MicroRNAs/genetics , Prognosis
10.
Front Microbiol ; 13: 846359, 2022.
Article in English | MEDLINE | ID: mdl-35369449

ABSTRACT

Rhizosphere microbial communities are vital for plant growth and soil sustainability; however, the composition of rhizobacterial communities, especially the assembly process and co-occurrence pattern among microbiota after the inoculation of some beneficial bacteria, remains considerably unclear. In this study, we investigated the structure of rhizomicrobial communities, their assembly process, and interactions contrasting when Bradyrhizobium japonicum 5038 and Bacillus aryabhattai MB35-5 are co-inoculated or Bradyrhizobium japonicum 5038 mono-inoculated in black and cinnamon soils of soybean fields. The obtained results indicated that the Chao and Shannon indices were all higher in cinnamon soil than that in black soil. In black soil, the co-inoculation increased the Shannon indices of bacteria comparing with that of the mono-inoculation. In cinnamon soil, the co-inoculation decreased the Chao indices of fungi comparing with that of mono-inoculation. Compared with the mono-inoculation, the interactions of microorganisms of co-inoculation in the co-occurrence pattern increased in complexity, and the nodes and edges of co-inoculation increased by 10.94, 40.18 and 4.82, 16.91% for bacteria and fungi, respectively. The co-inoculation of Bradyrhizobium japonicum 5038 and Bacillus aryabhattai MB35-5 increased the contribution of stochastic processes comparing with Bradyrhizobium japonicum 5038 inoculation in the assembly process of soil microorganisms, and owing to the limitation of species diffusion might restrict the direction of pathogenic microorganism movement. These findings support the feasibility of rebuilding the rhizosphere microbial system via specific microbial strain inoculation and provide evidence that the co-inoculation of Bradyrhizobium japonicum 5038 and Bacillus aryabhattai MB35-5 can be adopted as an excellent compound rhizobia agent resource for the sustainable development of agriculture.

11.
J Evid Based Med ; 15(1): 30-38, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35416437

ABSTRACT

OBJECTIVE: To evaluate the effectiveness and safety of Qingjin Yiqi granules (QJYQ) on post-COVID-19 condition (PCC). METHOD: Patients who met the inclusion criteria were randomly assigned to two groups, the QJYQ group received QJYQ combined with standard rehabilitation treatments (SRTs) and the control group only received SRTs. The treatment course was 14 days. The primary outcomes were modified Medical Research Council (mMRC) scale and Borg scale, while the secondary outcomes included symptoms score and 6-minute walking distance (6MWD). The safety outcome was the incidence of adverse events. RESULTS: A total of 388 patients with PCC were enrolled and randomly assigned to the QJYQ group (n = 194) and the control group (n = 194). Compared to the controls, the mMRC scale was improved in the QJYQ group, which was better than that of the control group [ß (95%CI): -0.626 (-1.101, -0.151), p = 0.010]. A significant improvement in Borg scale was also observed in the QJYQ group compared to the control group [ß (95%CI): -0.395(-0.744, -0.046), p = 0.026]. There was no statistically significant difference in symptoms score and 6MWD between the two groups (p = 0.293, p = 0.724). No treatment-related adverse events were observed in either group. CONCLUSIONS: QJYQ can bring benefits to patients with PCC, mainly in the improvement of breathlessness and fatigue.


Subject(s)
COVID-19 Drug Treatment , Humans , Treatment Outcome
12.
Ultramicroscopy ; 235: 113497, 2022 May.
Article in English | MEDLINE | ID: mdl-35193073

ABSTRACT

The development of ultrafast electron microscopy (UEM), specifically stroboscopic imaging, has brought the study of structural dynamics to a new level by overcoming the spatial limitations of ultrafast spectroscopy and the temporal restrictions of traditional TEM simultaneously. Combining the concepts governing both techniques has enabled direct visualization of dynamics with spatiotemporal resolutions in the picosecond-nanometer regime. Here, we push the limits of imaging using a pulsed electron beam via RF induced transverse deflection based on the newly developed 200 keV frequency-tunable strip-line pulser. We demonstrate a 0.2 nm spatial resolution and elucidation of magnetic spin induction maps using the phase-microscopy method. We also present beam coherence measurements and expand our study using the breathing modes of a silicon interdigitated comb under RF excitation which achieves improved temporal synchronization between the electron pulse-train and electric field. A new RF holder has also been developed with impedance matching to the RF signal to minimize transmission power loss to samples and its performance is compared with a conventional sample holder.

13.
Bioresour Technol ; 348: 126778, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35104655

ABSTRACT

Dry-wet combined anaerobic digestion is a novel approach for treating lignocellulosic waste by increasing the organic load of reactor while accelerating the conversion of organic acids. Here, we investigated the effect of regulated substrate ratios and initial pH in the dry acidogenesis stage on the bioconversion efficiency of dry-wet combined anaerobic digestion. Our data revealed microbial interactions and further identified key microbes based on microbial co-occurrence network analysis. On day three of acidification, the kinetic hydrolysis rate and acidification yield reached 1.66 and 60.07%, respectively; this was attributed to enhancement of the synergistic effect between Clostridiales and Methanosaeta, which increased the proportion of corn straw in the substrate or lowered the initial spray slurry pH to 5.5-6.5. With increased acidification capacity, acetoclastic methanogens were enriched in the wet methanogenesis stage; the syntrophic effect of Syntrophomonadales, Syntrophobacterales and Methanospirillum, meanwhile, was enhanced, leading to an overall improvement in biogas production.


Subject(s)
Biofuels , Bioreactors , Anaerobiosis , Lignin , Methane
14.
Acupunct Herb Med ; 2(2): 91-98, 2022 Jun.
Article in English | MEDLINE | ID: mdl-37808251

ABSTRACT

Objective: To describe patterns of utilization of traditional Chinese medicine (TCM) in the treatment of patients with coronavirus disease 2019 (COVID-19). Methods: Adult patients with COVID-19 who received TCM treatment were divided into a non-serious group (mild and moderate types) and a serious group (severe and critical types) according to their admission conditions. The medical records and prescriptions of these patients were investigated to determine their TCM utilization patterns. Results: In all, 3,872 COVID-19 patients were included. Oral Chinese traditional patent medicine (CPM) was the most commonly used type of TCM, followed by decoction. The proportion of multi-drug combinations was higher than single drug use (55.0% vs. 45.0%). Decoction combined with oral CPM was the most common combination (39.1%, 1,514/3,872). Orally administered, injected, and externally applied CPM were significantly more common in the serious group than in the non-serious, while decoction and non-drug TCM treatments were more common in the non-serious than in the serious group. Multi-drug combinations were used for the majority of patients in both groups, mainly in the form of decoctions combined with oral CPM. Among the serious patients, injected CPM was more often used in patients who died during treatment (35.0%, 36/103). The two most common medication patterns were decoction combined with oral CPM and oral CPM alone in the two finally discharged groups. Oral CPM alone or used in combination with injected CPM were seen most commonly in the death group. Significant differences were established in TCM utilization and medication patterns among patients in three groups who had different prognoses and outcomes. Conclusions: The treatment measures and medication patterns of TCM commonly used in COVID-19 patients with the range of conditions found in this study should be further explored in the future to provide a more complete reference for COVID-19 treatment.

15.
J Cancer ; 12(21): 6531-6542, 2021.
Article in English | MEDLINE | ID: mdl-34659544

ABSTRACT

Hepatocellular carcinoma (HCC) is one of the most common types of cancer worldwide. Circular RNAs (circRNAs) have been reported to regulate many types of cancers, including HCC. The purpose of this study was to investigate the potential roles of hsa_circ_0001306 in HCC. Firstly, the downregulation of hsa_circ_0001306 was identified by high­throughput RNA sequencing and further verified by qRT-PCR. Secondly, we evaluated the effects of hsa_circ_0001306 on HCC cell proliferation, invasion, cell cycle. Finally, we used an animal model to validate the in vitro experimental results. The expression of hsa_circ_0001306 was closely related to tumor size. Knockdown of hsa_circ_0001306 could downregulate F-box and WD repeat domain containing 7(FBXW7), a target of miR-527, thereby promoting HCC cell proliferation and invasion. Furthermore, hsa_circ_0001306 siRNA increased the multiplication rate of HCC tumors. Mechanistic studies indicated that hsa_circ_0001306 acts as a ceRNA for miR-527, which resulted in the reduction of its endogenous target, FBXW7. Hsa_circ_001306 is significantly downregulated in HCC, and the hsa_circ_0001306/miR-527/FBXW7 axis plays an important role in HCC progression.

16.
Langmuir ; 37(3): 1183-1193, 2021 Jan 26.
Article in English | MEDLINE | ID: mdl-33434433

ABSTRACT

The existing defects on the surface of CsPbX3 nanocrystals (NCs) resulted in the decrease of the photoluminescence quantum yields (PLQYs) of NCs. In this study, we developed a simple strategy, which can make the treated CsPbX3 NCs exhibit high PLQYs and better stability by CdX2 post-treatment at room temperature. The treated CsPbX3 NCs were characterized by X-ray diffraction (XRD) patterns and PL spectra. The shape, size, and crystal structure of the NCs remained unchanged after Cd ion treatment. The PLQYs of CsPbCl3 increased from 24 to 73% and the PLQYs of CsPbBr3 NCs increased from 85 to 92% after treatment. The significant enhancement of PLQYs is ascribed to the effective passivation of surface defects, in which Cd2+ and X- ions occupied the Pb-X vacancies existing on the surface of the NCs. In addition, this strategy was also applied to a mixed halide perovskite. The practical application of CsPbX3 NCs will be extended by this method.

17.
Water Res ; 188: 116466, 2021 Jan 01.
Article in English | MEDLINE | ID: mdl-33027695

ABSTRACT

The carbon/nitrogen ratio (C/N) is a key parameter that affects the performance of anaerobic digestion (AD). Recent AD research has focused on optimizing the C/N of feedstock. The so-called "inhibited steady-state" refers to a special state of ammonia inhibition of AD that often occurs at low-C/N (below 25) when degradable nitrogen-rich substrates, such as livestock manure, are used as feedstock. However, the mechanism behind the "inhibited steady-state" is still unknown. In the current study, co-digestion and recirculation were used to create a C/N gradient in the influent to explore the relationship between substrates, metabolites, and microorganisms in the "inhibited steady-state." Data were collected at the macro, microbial, and genetic levels. Three CSTRs were successfully made run into the "inhibited steady-state" using influent C/Ns of 10-12. Digestion performance levels of R10-R12 were low and stable, transitioning from an aceticlastic methane-producing pathway to a hydrogenotrophic pathway as the C/N gradually decreased. As the abundance of the hydrogenophilic methanogens increased, the abundance of syntrophic acetate-oxidizing bacteria (SAOB) also increased. The succession between populations of Methanosaeta and Methanosarcina may be used as a microbiological indicator of ammonia inhibition. Under high-C/Ns, cooperation among bacteria was high, while under low-C/Ns, competition among bacteria was high. These results clarify the processes underlying the "inhibited steady-state," which is a condition often faced in actual large-scale biogas facilities that use degradable nitrogen-rich substrates. Moreover, practical guidelines for evaluating ammonia inhibition are provided, and strategies to alleviate ammonia suppression are developed.


Subject(s)
Bioreactors , Nitrogen , Ammonia , Anaerobiosis , Biofuels , Carbon , Methane
18.
Sci Adv ; 6(40)2020 Oct.
Article in English | MEDLINE | ID: mdl-33008895

ABSTRACT

Integrating femtosecond lasers with electron microscopies has enabled direct imaging of transient structures and morphologies of materials in real time and space. Here, we report the development of a laser-free ultrafast electron microscopy (UEM) offering the same capability but without requiring femtosecond lasers and intricate instrumental modifications. We create picosecond electron pulses for probing dynamic events by chopping a continuous beam with a radio frequency (RF)-driven pulser with the pulse repetition rate tunable from 100 MHz to 12 GHz. As a first application, we studied gigahertz electromagnetic wave propagation dynamics in an interdigitated comb structure. We reveal, on nanometer space and picosecond time scales, the transient oscillating electromagnetic field around the tines of the combs with time-resolved polarization, amplitude, and local field enhancement. This study demonstrates the feasibility of laser-free UEM in real-space visualization of dynamics for many research fields, especially the electrodynamics in devices associated with information processing technology.

19.
Sci Total Environ ; 736: 139159, 2020 Sep 20.
Article in English | MEDLINE | ID: mdl-32485390

ABSTRACT

The mechanisms and enhancing effects of different biochar loadings on the digesters receiving low and high excess (or anaerobic) sludge loadings were thoroughly examined in the present study. This was done to explore an efficient method for converting excess sludge to anaerobic sludge. Biochar had an obvious effect on the anaerobic digestion of excess sludge but not on the anaerobic sludge. When the amount of biochar added was equivalent to 100% of the sludge TS, the cumulative methane yields of anaerobic digestion inoculated with small and large amounts of excess sludge were respectively 30.2 and 1.7 times that of those without biochar. The number of methanogens in the digesters that received small and large inoculations of excess sludge with 100% biochar, were respectively 105.4% and 20.6% higher than those without biochar. The biochar enhanced the systems performance because it selectively enriched the Trichococcus and Methanomicrobiales tightly attach to it. This enhanced the synergy and overall activity of the system by promoting biofilm development. Ultimately, the integration of 100% biochar and excess sludge can be used as a substitute for anaerobic sludge as an inoculum by giving similar overall performance.


Subject(s)
Charcoal , Sewage , Anaerobiosis , Bioreactors , Methane
20.
J Nanosci Nanotechnol ; 20(10): 6334-6343, 2020 10 01.
Article in English | MEDLINE | ID: mdl-32384983

ABSTRACT

On the basis of maintaining the original characteristics of each component, the composite material obtains the properties that the single component does not have through the synergy between the components. It is of great significance to understand the synergy between the components for the development of the composite. First of all, we prepared different emitting CdTe quantum dots (QDs), and then fabricated CdTe QDs@reduced graphene oxide (rGO) composites by a simple ultrasonic method. It is found that the fluorescence of QDs quenched, the photocurrent significantly improved, but the growth rate different from each other because of the different QDs. Afterwards, on the basis of naked QDs, hybrid SiO2-coated QDs were fabricated by a two-step method. After that, hybrid SiO2-coated CdTe QDs@rGO composites were prepared by the same method. It is found that the existence of the hybrid SiO2 shell leads to the decrease of photocurrent of the composites before and after coating, but the specific capacitance significantly improved, and the cycle stability also better than the naked QDs. This research will make grapheme-based composites have broad application prospects in energy storage equipment.

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