Analysis of Pollution in Dianchi Lake and Consideration of Its Application in Crop Planting

AbstractAfter investigating the distribution and composition of N-cycle-related bacteria of different sites and different depth of Dianchi sediment, we analyzed the longitudinal distribution, lateral distribution of N, its transportation and transformation in Dianchi sediment, as well as the involvement of these bacteria in nitrogen cycle. Conclusion was drawn as follows, (1) Azotobateria could be effectively used as indicative strains to track the changes of Dianchi pollution because the distribution of Azotobateria can not only indicate N contamination but also P enrichment, (2) ammoniate and nitrite is mainly existed in top sediment of Dianchi Lake while other forms of nitrogen mainly in deeper sediment, (3) due to the fact that Dianchi is rich in P, together with the mutual promotion between N pollution and P pollution, the pollution of south part will worsen rapidly, (4) if the south part is also polluted badly, the pollution distribution will appear as peaking at both ends (north and south), and the pollution will definitely extend toward the middle, and finally Dianchi Lake will totally be seriously polluted. Combining with the fact that 40% of Dianchi pollution was caused by abusive use of chemical fertilizer, we put forward the idea of “changing pollutants into things of value”, which could be specified as “using the sediment as agricultural fertilizer”. Such method can solve the problem of internal pollution, and what's more, it can develop agriculture, while cut down the use of chemical fertilizer and thus reduce relative pollution source

Tau-PET imaging in Parkinson's disease: a systematic review and meta-analysis

BackgroundPathological tau accumulates in the cerebral cortex of Parkinson's disease (PD), resulting in cognitive deterioration. Positron emission tomography (PET) can be used for in vivo imaging of tau protein. Therefore, we conducted a systematic review and meta-analysis of tau protein burden in PD cognitive impairment (PDCI), PD dementia (PDD), and other neurodegenerative diseases and explored the potential of the tau PET tracer as a biomarker for the diagnosis of PDCI.MethodsPubMed, Embase, the Cochrane Library, and Web of Science databases were systematically searched for studies published till 1 June 2022 that used PET imaging to detect tau burden in the brains of PD patients. Standardized mean differences (SMDs) of tau tracer uptake were calculated using random effects models. Subgroup analysis based on the type of tau tracers, meta-regression, and sensitivity analysis was conducted.ResultsA total of 15 eligible studies were included in the meta-analysis. PDCI patients (n = 109) had a significantly higher tau tracer uptake in the inferior temporal lobe than healthy controls (HCs) (n = 237) and had a higher tau tracer uptake in the entorhinal region than PD with normal cognition (PDNC) patients (n = 61). Compared with progressive supranuclear palsy (PSP) patients (n = 215), PD patients (n = 178) had decreased tau tracer uptake in the midbrain, subthalamic nucleus, globus pallidus, cerebellar deep white matter, thalamus, striatum, substantia nigra, dentate nucleus, red nucleus, putamen, and frontal lobe. Tau tracer uptake values of PD patients (n = 178) were lower than those of patients with Alzheimer's disease (AD) (n = 122) in the frontal lobe and occipital lobe and lower than those in patients with dementia with Lewy bodies (DLB) (n = 55) in the occipital lobe and infratemporal lobe.ConclusionIn vivo imaging studies with PET could reveal region-specific binding patterns of the tau tracer in PD patients and help in the differential diagnosis of PD from other neurodegenerative diseases.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/

Progress in electrolyte-free fuel cells

Solid oxide fuel cell (SOFC) represents a clean electrochemical energy conversion technology with characteristics of high conversion efficiency and low emissions. It is one of the most important new energy technologies in the future. However, the manufacture of SOFCs based on the structure of anode/electrolyte/cathode is complicated and time-consuming. Thus, the cost for the entire fabrication and technology is too high to be affordable, and challenges still hinder commercialization. Recently, a novel type of electrolyte-free fuel cell (EFFC) with single component was invented, which could be the potential candidate for the next generation of advanced fuel cells. This paper briefly introduces the EFFC, working principle, performance, and advantages with updated research progress. A number of key R&D issues about EFFCs have been addressed, and future opportunities and challenges are discussed

Impact of the COVID-19 lockdown on air pollution in an industrial city in Northeastern China

Many studies in China investigated how the lockdown following the coronavirus disease 2019 substantially affected air quality; however, few were conducted in Northeastern China. Here, the changes in six criteria air pollutants, including particulate matter (PM10 and PM2.5), nitrogen dioxide (NO2), carbon monoxide (CO), sulfur dioxide (SO2), and ozone (O3), were investigated in Shenyang from January to May 2015–2020. Compared with the pre-lockdown, the mass concentrations of PM2.5, PM10, SO2, NO2, and CO during the lockdown decreased by 40.3% to 48.6%, indicating a positive impact of lockdown policies on reducing pollutant emissions. The responses of PM2.5, PM10, and CO to the lockdown measures in downtown areas were more sensitive than in the suburbs. However, the O3 concentration showed the opposite trend, attributed to the drop in NOx and particulate matters. Compared to the same period in 2015–2019, the proportion of days with good air quality increased from 63.2% to 77.2% during the lockdown and Shenyang experienced no severe pollution. Our results suggest that reducing human activities can improve air quality; however, coordinated control policies of O3, PM2.5, and NO2 are imperative.

High PGL productivity in

Alkaline polygalacturonate lyase (PGL, EC 4.2.2.2) can catalyze the cleavage of a-1, 4-glycosidic bonds of polygalacturonate by a trans-elimination reaction and generate an unsaturated oligogalacturonates. As the critical enzyme of many environmental friendly processes, alkaline PGL has been widely used in many fields including paper, textile and beverage industries. At present, Bacillus subtilis is an ideal strain for producing PGL, but the yield is too low for industrial production. In this study, the effect of different SD sequences on the production of PGL was comparatively investigated, and the strong SD sequence (AGAGAACAAGGAGGG G) directed efficient PGL secretory expression and increased PGL yield to 264.5 U·mL-1 with a high productivity. As a result, the PGL yield in B. subtilis was effecively increased and laid the solid foundation for PGL industrial production

Synthesis of Novel Ternary Dual Z-scheme AgBr/LaNiO3/g-C3N4 Composite with Boosted Visible-Light Photodegradation of Norfloxacin

Promoting the separation of photogenerated charges and enhanced optical absorption capacity is the main means to modify photocatalytic capacities to advance semiconductor photocatalyst applications. For the first time, a novel ternary photocatalyst for dual Z-scheme system AgBr/LaNiO3/g-C3N4 (ALG) was prepared via a modest ultrasound-assisted hydrothermal method. The results indicated that LaNiO3 nanoballs and AgBr nanoparticles were successfully grown on the surface of g-C3N4 nanosheets. A dual Z-scheme photocatalytic reaction system could be constructed based on the energy band matching within AgBr, LaNiO3 and g-C3N4. Metallic Ag during the photocatalytic reaction process acted as the active electrons transfer center to enhance the photocatalytic charge pairs separation. The chemical composition of ALG was optimized and composites with 3% AgBr, 30% LaNiO3 and 100% g-C3N4 which was noted as 3-ALG displayed the best photocatalytic performance. A total of 92% of norfloxacin (NOR) was photodegraded within two hours over ALG and the photodegradation rate remained >90% after six cycles. The main active species during the degradation course were photogenerated holes, superoxide radical anion and hydroxyl radical. A possible mechanism was proposed based on the synergetic effects within AgBr, LaNiO3 and g-C3N4. This work would offer a credible theoretical basis for the application of dual Z-scheme photocatalysts in environment restoration

Increased production of alkaline polygalacturonate lyase in the recombinant WB43CB by optimizing the medium

Alkaline polygalacturonate lyase (PGL), which was the central enzyme of green environmental enzyme treatment technology, has been widely used in textile, papermaking and beverage production. In the previous work, Bacillus subtilis was used as the expression host, and the PGL gene derived from B. subtilis WSHB04-02 was successfully expressed in the engineered strain WB43CB by regulating of molecular elements such as signal peptide, promoter and SD sequence. In this study, the fermentation medium was optimized from four aspects of carbon source, nitrogen source, liquid volume and inoculum volume, and the extracellular PGL enzyme activity in WB43CB increased from 264.5 U·mL-1 to 461.96 U·mL-1, which laid a solid foundation for the industrial production of PGL

Screening and identification of desulfurization microorganisms

In recent years, biological desulfurization technology has attracted more and more attention from domestic and foreign researchers due to its mild reaction conditions, high efficiency, and environmental protection. In this study, bacteria were collected from oil depots, sewage treatment plants and sewage, and using a screening medium with DBT as the only sulfur source. Three strains that can degrade DBT were isolated, numbered 1, 2, and 3. Through the identification of morphological characteristics, physiological and biochemical identification and molecular identification, it is preliminarily determined that the bacteria No. 1 belongs to the genus Kinetococcus, the bacteria No. 2 is Micrococcus mutans, the bacteria No. 3 is Micrococcus luteus, and the desulfurization capacity of the three bacteria is No. 3. Bacteria > Bacteria No.1 > Bacteria No.2

World Conference on Acoustic Emission-2017

This volume collects the papers from the World Conference on Acoustic Emission 2017 (WCAE-2017) in Xi'an, China. The latest research and applications of acoustic emission (AE) are explored, with a particular emphasis on detecting and processing AE signals, the development of AE instrument and testing standards, AE of materials, engineering structures and systems, including the processing of collected data and analytical techniques. Numerous case studies are also included. This proceedings volume will appeal to students, professors and researchers working in these fields as physicists and/or engineers