The NF-κB/Relish Activates miR-308 to Negatively Regulate Imd Pathway Immune Signaling in Drosophila.

The strength and duration of the NF-κB signaling response must be tightly modulated to avoid an inadequate or excessive immune response. Relish, a core NF-κB transcription factor of the Drosophila Imd pathway, can control the expression of antimicrobial peptides, including Dpt and AttA, to defend against Gram-negative bacterial infections, but whether Relish may regulate miRNA expression to participate in the immune response remains unclear. In this study, taking advantage of Drosophila S2 cells and different overexpression/knockout/knockdown flies, we first found that Relish could directly activate the expression of miR-308 to negatively regulate the immune response and promote the survival of Drosophila during Enterobacter cloacae infection. Second, our results demonstrated that Relish-mediated expression of miR-308 could suppress target gene Tab2 to attenuate the Drosophila Imd pathway signal during the middle and late stages of the immune response. Third, we detected the dynamic expression patterns of Dpt, AttA, Relish, miR-308, and Tab2 in wild-type flies after E. coli infection, which further revealed that the feedback regulatory loop of Relish-miR-308-Tab2 plays a crucial role in the immune response and homeostasis maintenance of the Drosophila Imd pathway. Overall, our present study not only illustrates an important mechanism by which this Relish-miR-308-Tab2 regulatory axis can negatively control the Drosophila immune response and participate in homeostasis maintenance but also provides new insights into the dynamic regulation of the NF-κB/miRNA expression network of animal innate immunity.

Real-World Emission Characteristics of Full-Volatility Organics Originating from Nonroad Agricultural Machinery during Agricultural Activities.

Nonroad agricultural machinery (NRAM) emissions constitute a significant source of air pollution in China. Full-volatility organics originating from 19 machines under 6 agricultural activities were measured synchronously. The diesel-based emission factors (EFs) for full-volatility organics were 4.71 ± 2.78 g/kg fuel (average ± standard deviation), including 91.58 ± 8.42% volatile organic compounds (VOCs), 7.94 ± 8.16% intermediate-volatility organic compounds (IVOCs), 0.28 ± 0.20% semivolatile organic compounds (SVOCs), and 0.20 ± 0.16% low-volatility organic compounds (LVOCs). Full-volatility organic EFs were significantly reduced by stricter emission standards and were the highest under pesticide spraying activity. Our results also demonstrated that combustion efficiency was a potential factor influencing full-volatility organic emissions. Gas-particle partitioning in full-volatility organics could be affected by multiple factors. Furthermore, the estimated secondary organic aerosol formation potential based on measured full-volatility organics was 143.79 ± 216.80 mg/kg fuel and could be primarily attributed to higher-volatility-interval IVOCs (bin12-bin16 contributed 52.81 ± 11.58%). Finally, the estimated emissions of full-volatility organics from NRAM in China (2021) were 94.23 Gg. This study provides first-hand data on full-volatility organic EFs originating from NRAM to facilitate the improvement of emission inventories and atmospheric chemistry models.

Nuclear Quantum Effects on the Charge-Density Wave Transition in NbX2 (X = S, Se).

Understanding the origin of charge-density wave (CDW) instability is important for manipulating novel collective electronic states. Many layered transition metal dichalcogenides (TMDs) share similarity in the structural and electronic instability, giving rise to diverse CDW phases and superconductivity. It is still puzzling that even isostructural and isoelectronic TMDs show distinct CDW features. For instance, bulk NbSe2 exhibits CDW order at low temperature, while bulk NbS2 displays no CDW instability. The CDW transitions in single-layer NbS2 and NbSe2 are also different. In the classic limit, we investigate the electron correlation effects on the dimensionality dependence of the CDW ordering. By performing ab initio path integral molecular dynamics simulations and comparative analyses, we further revealed significant nuclear quantum effects in these systems. Specifically, the quantum motion of sulfur anions significantly reduces the CDW transition temperature in both bulk and single-layer NbS2, resulting in distinct CDW features in the NbS2 and NbSe2 systems.

The clinical characteristics and prognosis of COVID-19 patients with cerebral stroke: A retrospective study of 113 cases from one single-centre.

To explore the clinical characteristics and prognosis of COVID-19 patients with cerebral stroke. A total of 2,474 COVID-19 patients from February 10th to March 24th, 2020 were admitted and treated in two branches (Optic Valley and Sino-French New City branch) of the Tongji Hospital. Data on the clinical characteristics, laboratory parameters and prognosis of COVID-19 patients with or without cerebral stroke were collected and comparatively analysed. Of the 2,474 COVID-19 patients, 113 (4.7%) patients had cerebral stroke and 25 (1.0%) patients had new-onset stroke. Eighty-eight (77.9%) patients in the previous-stroke group had cerebral ischaemia, while 25 (22.1%) patients in the new-onset stroke group had cerebral ischaemia. Most COVID-19 patients with stroke were elderly with more comorbidities such as hypertension, diabetes and heart diseases than patients without stroke. Laboratory examinations showed hypercoagulation and elevated serum parameters such as IL-6, cTnI, NT pro-BNP and BUN. Consciousness disorders, a long disease course and poor prognosis were also more commonly observed in stroke patients. The mortality rate of stroke patients was almost double (12.4% vs. 6.9%) that of patients without stroke. In addition, age, male sex and hypertension were independent predictors for new cerebral stroke in COVID-19 patients. In conclusion, the high risk of new-onset stroke must be taken into consideration when treating COVID-19 patients with an elderly age combined with a history of hypertension. These patients are more vulnerable to multiorgan dysfunction and an overactivated inflammatory response, in turn leading to an unfavourable outcome and higher mortality rate.

Sodium houttuyfonate attenuates neurological defects after traumatic brain injury in mice via inhibiting NLRP3 inflammasomes.

Sodium houttuyfonate (SH) is a chemical compound synthesized by houttuynin and sodium bisulfite. As it has antinflammatory effects, SH has been widely used to treat autoimmune diseases, including post events following traumatic brain injury (TBI). Meanwhile, NOD-like receptor with pyrin domain containing-3 (NLRP3) inflammasomes in microglia may play a central role in TBI. But to date, the intracellular mechanisms involved in the anti-inflammatory effects of SH in TBI remain unknown, especially whether regulating NLRP3. To gain an insight into this possibility, we conducted cell culture and biochemical studies on the effect of SH on NLRP3 inflammasome in microglia. The results showed that SH inhibited TLR4 and NLRP3 inflammasome activation in the microglia cell. In parallel, phosphorylation of ERK and NF-κB p65, which play a key role in NLRP3 inflammasome formation, was decreased. Intraperitoneal injection of SH into TBI mice significantly reduced the modified neurological severity score (mNSS), as well as the degree of microglia apoptosis post-controlled cortical impact (CCI). Immunohistochemistry, Western blot analysis, and reverse-transcription polymerase chain reaction (RT-PCR) revealed that SH markedly reduced NLRP3 inflammasome activation, TLR4 activity, phosphorylation of ERK and NF-κB. Moreover, SH significantly inhibited microglia activation post-CCI, but effectively promoted the astrocyte activation and angiopoiesis. Taken together, our research provides evidence that SH attenuated neurological deficits post TBI through inhibiting NLRP3 inflammasome activation, via influencing the TLR4/NF-κB signaling pathway. These findings explain the intracellular mechanism of the anti-inflammatory activity caused by SH treatment following TBI.

First-Principles Study on Electron-Induced Excitations of Atomic Layer Deposition Precursors: Inelastic Electron Wave Packet Scattering with Cobalt Tricarbonyl Nitrosyl Co(CO)3NO Using Time-Dependent Density Functional Theory.

A quantitative study on inelastic electron scattering with a molecule is of significant importance for understanding the essential mechanisms of electron-induced gas-phase and surface chemical reactions in their excited electronic states. A key issue to be addressed is the quantitatively detailed inelastic electron collision processes with a realistic molecular target, associated with electron excitation that leads to potential ionization and dissociation reactions of the molecule. Using the real-time time-dependent density functional theory (TDDFT) modeling, we present quantitative findings on the energy transfers and internal excitations for the low energy (up to 270 eV) electron wave packet impact with the molecular target cobalt tricarbonyl nitrosyl (CTN, Co(CO)3NO) that is used as a precursor in electron-enhanced atomic layer deposition (EE-ALD) growth of Co films. Our modeling shows the quantitative dependence of the wave packet sizes, target molecule orientations, and impact parameters on the energy transfer in this inelastic electron scattering process. It is found that the wave packet sizes have little effect on the overall profile of the internal multiple excited states, whereas different target orientations can cause significantly different internal excited states. To evaluate the quantitative prediction capability, the inelastic scattering cross-section of a hydrogen atom is calculated and compared with the experimental data, leading to a constant scaling factor over the whole energy range. The present study demonstrates the remarkable potential of TDDFT for simulating the inelastic electron scattering process, which provides critical information for future exploration of electronic excitations in a wide range of electron-induced chemical reactions in current technological applications.

The biological pump effects of phytoplankton on the occurrence and benthic bioaccumulation of hydrophobic organic contaminants (HOCs) in a hypereutrophic lake.

The distribution of hydrophobic organic contaminants (HOCs) in eutrophic ecosystems has been widely studied, but how phytoplankton blooms affect their occurrence and benthic bioaccumulation is poorly understood. To fill this knowledge gap, the biological pump effects of phytoplankton on the fate of organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) in sediments and benthos (Corbicula fluminea) from Lake Taihu, a hypereutrophic lake in China, were identified. The spatial-temporal distribution of HOCs suggests that higher phytoplankton biomass, coupled with sediment organic matter (SOM) content, greatly increased the concentration of HOCs in sediments in both winter and summer seasons. This could be attributed to the biological pump effects sequestering more HOCs from water to sediments with settling phytoplankton, especially during the summer. The biological pump effects further promoted the uptake of sediment-bound HOCs by benthos. The significant positive relationships between concentrations of HOCs in sediments and benthos were observed during the winter dormancy phase of benthos. Furthermore, the benthic bioaccumulation of HOCs could be strengthened by phytoplankton, due to their contribution to SOM and the following increased bioavailability of HOCs in sediments. Further research is needed to elucidate the phytoplankton biological pump effects on the fate of HOCs in benthic food chain, especially for hypereutrophic waters.

The Drosophila miR-959-962 Cluster Members Repress Toll Signaling to Regulate Antibacterial Defense during Bacterial Infection.

MicroRNAs (miRNAs) are a class of ~22 nt non-coding RNA molecules in metazoans capable of down-regulating target gene expression by binding to the complementary sites in the mRNA transcripts. Many individual miRNAs are implicated in a broad range of biological pathways, but functional characterization of miRNA clusters in concert is limited. Here, we report that miR-959-962 cluster (miR-959/960/961/962) can weaken Drosophila immune response to bacterial infection evidenced by the reduced expression of antimicrobial peptide Drosomycin (Drs) and short survival within 24 h upon infection. Each of the four miRNA members is confirmed to contribute to the reduced Drs expression and survival rate of Drosophila. Mechanically, RT-qPCR and Dual-luciferase reporter assay verify that tube and dorsal (dl) mRNAs, key components of Toll pathway, can simultaneously be targeted by miR-959 and miR-960, miR-961, and miR-962, respectively. Furthermore, miR-962 can even directly target to the 3' untranslated region (UTR) of Toll. In addition, the dynamic expression pattern analysis in wild-type flies reveals that four miRNA members play important functions in Drosophila immune homeostasis restoration at the late stage of Micrococcus luteus (M. luteus) infection. Taken together, our results identify four miRNA members from miR-959-962 cluster as novel suppressors of Toll signaling and enrich the repertoire of immune-modulating miRNA in Drosophila.

Superinfection Exclusion by p28 of Turnip Crinkle Virus Is Separable from Its Replication Function.

We recently reported that the p28 auxiliary replication protein encoded by turnip crinkle virus (TCV) is also responsible for eliciting superinfection exclusion (SIE) against superinfecting TCV. However, it remains unresolved whether the replication function of p28 could be separated from its ability to elicit SIE. Here, we report the identification of two single amino acid mutations that decouple these two functions. Using an Agrobacterium infiltration-based delivery system, we transiently expressed a series of p28 deletion and point mutants, and tested their ability to elicit SIE against a cointroduced TCV replicon. We found that substituting alanine (A) for valine (V) and phenylalanine (F) at p28 positions 181 and 182, respectively, modestly compromised SIE in transiently expressed p28 derivatives. Upon incorporation into TCV replicons, V181A and F182A decoupled TCV replication and SIE diametrically. Although V181A impaired SIE without detectably compromising replication, F182A abolished TCV replication but had no effect on SIE once the replication of the defective replicon was restored through complementation. Both mutations diminished accumulation of p28 protein, suggesting that p28 must reach a concentration threshold in order to elicit a strong SIE. Importantly, the severe reduction of F182A protein levels correlated with a dramatic loss in the number of intracellular p28 foci formed by p28-p28 interactions. Together, these findings not only decouple the replication and SIE functions of p28 but also unveil a concentration dependence for p28 coalescence and SIE elicitation. These data further highlight the role of p28 multimerization in driving the exclusion of secondary TCV infections.

Astrocyte-derived exosomes enriched with miR-873a-5p inhibit neuroinflammation via microglia phenotype modulation after traumatic brain injury.

BACKGROUND: The interaction between astrocytes and microglia plays a vital role in the damage and repair of brain lesions due to traumatic brain injury (TBI). Recent studies have shown that exosomes act as potent mediators involved in intercellular communication. METHODS: In the current study, the expression of inflammatory factors and miR-873a-5p in the lesion area and oedema area was evaluated in 15 patients with traumatic brain injury. Exosomes secreted by astrocytes were detected by immunofluorescence, Western blot and electron microscopy. A mouse model of TBI and an in vitro model of LPS-induced primary microglia were established to study the protective mechanism of exosomes from miR-873a-5p overexpressing in TBI-induced nerve injury. RESULTS: We discovered that exosomes derived from activated astrocytes promote microglial M2 phenotype transformation following TBI. More than 100 miRNAs were detected in these astrocyte-derived exosomes. miR-873a-5p is a major component that was highly expressed in human traumatic brain tissue. Moreover, miR-873a-5p significantly inhibited LPS-induced microglial M1 phenotype transformation and the subsequent inflammation through decreased phosphorylation of ERK and NF-κB p65. This effect also greatly improved the modified neurological severity score (mNSS) and attenuated brain injury in a strictly controlled cortical impact mouse model. CONCLUSIONS: Taken together, our research indicates that miRNAs in the exosomes derived from activated astrocytes play a key role in the astrocyte-microglia interaction. miR-873a-5p, as one of the main components of these astrocyte-derived exosomes, attenuated microglia-mediated neuroinflammation and improved neurological deficits following TBI by inhibiting the NF-κB signalling pathway. These findings suggest a potential role for miR-873a-5p in treating traumatic brain injury.

Real-time ab initio simulation of inelastic electron scattering using the exact, density functional, and alternative approaches.

To investigate inelastic electron scattering, which is ubiquitous in various fields of study, we carry out ab initio study of the real-time dynamics of a one-dimensional electron wave packet scattered by a hydrogen atom using different methods: the exact solution, the solution provided by time-dependent density functional theory (TDDFT), and the solutions given by alternative approaches. This research not only sheds light on inelastic scattering processes but also verifies the capability of TDDFT in describing inelastic electron scattering. We revisit the adiabatic local-density approximation (ALDA) in describing the excitation of the target during the scattering process along with a self-interaction correction and spin-polarized calculations. Our results reveal that the ALDA severely underestimates the energy transferred in the regime of low incident energy particularly for a spin-singlet system. After demonstrating alternative approaches, we propose a hybrid ab initio method to deal with the kinetic correlation alongside TDDFT. This hybrid method would facilitate first-principles studies of systems in which the correlation of a few electrons among many others is of interest.

Interleukin 4 inhibits high mobility group box-1 protein-mediated NLRP3 inflammasome formation by activating peroxisome proliferator-activated receptor-γ in astrocytes.

High mobility group box-1 protein (HMGB-1) is one of the most important DAMPs and has been previously shown to promote the formation of the NOD-like receptor with pyrin domain containing-3 (NLRP3) inflammasome in microglia. Interleukin 4 (IL4) is a Th2-derived cytokine that plays a significant role in the function of various immune cells. However, the underlying molecular mechanism by which IL4 signaling antagonizes NLRP3 inflammasome is poorly characterized. In particular, whether IL4 could modulate NLRP3 inflammasome in astrocytes remains unknown. In the present study, we elucidated this phenomenon and the mechanism by which IL4 inhibits HMGB1-mediated NLRP3 inflammasome formation in astrocytes. For this purpose, we cultured and extracted primary astrocytes, setup different concentrations of HMGB1, and used immunofluorescence and western blotting to detect NLRP3 inflammasome formation, including NLRP3, ASC and caspase-1, and signaling changes in the nuclear factor κB (NF-κB). Meanwhile, BAY 11-7082 and IL4 were added with HMGB1 to observe the NLRP3 inflammasome and changes in NF-κB expression. Our data showed that HMGB1 could effectively promote NLRP3 inflammasome formation by activating NF-κB in astrocytes. This effect can be inhibited by BAY 11-7082, a NF-κB inhibitor. Meanwhile, IL4 could activate PPARγ via the STAT6 singling pathway and inhibit NF-κB activation, significantly decreasing formation of the NLRP3 inflammasome complex. Our study demonstrated that the NLRP3 inflammasome complex is also expressed in astrocytes, and IL4 could inhibit HMGB1-mediated NLRP3 inflammasome formation, through negative regulation of NF-κB activity and promotion of PPARγ activation.

Variability in Dissolved Organic Matter Composition and Biolability across Gradients of Glacial Coverage and Distance from Glacial Terminus on the Tibetan Plateau.

Globally, alpine glaciers hold a large quantity of dissolved organic matter (DOM) and are headwaters of numerous rivers supporting downstream heterotrophic metabolism. However, it remains unclear how glacial coverage and distance from the glacial terminus affect the fate of DOM. Here, we elucidate DOM variability in glacial-fed streams on the Tibetan Plateau using field sampling and bioincubation experiments and compare our findings with the existing literature. We found that dissolved organic carbon, DOM absorption a(254), DOM aromaticity, and the relative abundance of lignin compounds in glacial-fed streams and rivers all increased with increasing distance from the glacial terminus and with decreasing glacial coverage. We also found that contribution of protein-like components, the relative abundance of aliphatic compounds, and DOM biolability increased with increasing glacial coverage and with decreasing distance from the glacial terminus. The ratio of glacial coverage to the logarithmic transformed distance from the glacial terminus was better than that of actual glacial coverage and distance from the glacial terminus in tracing the variability of glacial-fed stream DOM. Microbes in surface ice can produce biolabile DOM that is exported downstream with meltwater. This glacial-fed stream and river DOM is an important source of the highly bioavailable material fueling downstream heterotrophic activity.

Accumulation of Terrestrial Dissolved Organic Matter Potentially Enhances Dissolved Methane Levels in Eutrophic Lake Taihu, China.

Inland waters play an important role for the storage of chromophoric dissolved organic matter (CDOM) and outgassing of methane (CH4). However, to date, linkages between the optical dynamics of CDOM and dissolved CH4 levels remain largely unknown. We used multi-year (2012-2014) seasonal data series collected from Lake Taihu and 51 connecting channels to investigate how CDOM optical dynamics may impact dissolved CH4 levels in the lake. High dissolved CH4 in the northwestern inflowing river mouths coincided with high underwater UV-vis light availability, dissolved organic carbon (DOC), chemical oxygen demand (COD), DOM aromaticity, terrestrial humic-rich fluorescence, in situ measured terrestrial CDOM, depleted dissolved oxygen (DO), stable isotopic δ2H, and δ18O compared with other lake regions. Our results further revealed positive relationships between dissolved CH4 and CDOM absorption at 350 nm, i.e. a(350), COD, DOC, terrestrial humic-rich fluorophores, and DOM aromaticity, and negative relationships between dissolved CH4 and DO, δ2H, and δ18O. The central lake samples showed a major contribution of terrestrial-sourced molecular formulas to the ultrahigh resolution mass spectrometry data, suggesting the presence of allochthonous DOM sources even here. We conclude that an elevated terrestrial CDOM input likely enhances dissolved CH4 levels in Lake Taihu.

A bibliometric review of nitrogen research in eutrophic lakes and reservoirs.

The global application of nitrogen is far greater than phosphorus, and it is widely involved in the eutrophication of lakes and reservoirs. We used a bibliometric method to quantitatively and qualitatively evaluate nitrogen research in eutrophic lakes and reservoirs to reveal research developments, current research hotspots, and emerging trends in this area. A total of 2695 articles in the past 25years from the online database of the Scientific Citation Index Expended (SCI-Expanded) were analyzed. Articles in this area increased exponentially from 1991 to 2015. Although the USA was the most productive country over the past 25years, China achieved the top position in terms of yearly publications after 2010. The most active keywords related to nitrogen in the past 25years included phosphorus, nutrients, sediment, chlorophyll-a, carbon, phytoplankton, cyanobacteria, water quality, modeling, and stable isotopes, based on analysis within 5-year intervals from 1991 to 2015 as well as the entire past 25years. In addition, researchers have drawn increasing attention to denitrification, climate change, and internal loading. Future trends in this area should focus on: (1) nutrient amounts, ratios, and major nitrogen sources leading to eutrophication; (2) nitrogen transformation and the bioavailability of different nitrogen forms; (3) nitrogen budget, mass balance model, control, and management; (4) ecosystem responses to nitrogen enrichment and reduction, as well as the relationships between these responses; and (5) interactions between nitrogen and other stressors (e.g., light intensity, carbon, phosphorus, toxic contaminants, climate change, and hydrological variations) in terms of eutrophication.

Origin of OER catalytic activity difference of oxygen-deficient perovskites A2Mn2O5 (A = Ca, Sr): A theoretical study.

Mn-based oxygen-deficient perovskite catalysts A2Mn2O5 (A = Ca, Sr) have been experimentally proved high oxygen evolution reaction (OER) activities for replacing Pt in oxygen electrocatalysis. Nevertheless, the correlation between the fundamental electronic structure at room temperature and the corresponding electrocatalysis is not fully accessible. In this paper, we combine the ground state density functional theory (DFT) method and dynamic mean-field theory (DFT+DMFT) at room temperature to investigate the origin of the OER difference for electrocatalysts A2Mn2O5 (A = Ca, Sr). We find that at room temperature the highest occupied Mn dz2 orbital in the square pyramidal crystal field of oxygen-deficient perovskites A2Mn2O5 with insulating properties can provide a moderate bonding strength with intermediate hydroxyl OH*, leading to a high OER catalytic activity. According to the electronic structure analysis, we observe that replacing the A-site element Ca by Sr with the larger ionic radii would result in a higher OER activity due to the weakened hybridization between the Mn dz2 orbital and the O pσ orbital of OH*. This insight could provide hints for the screening metal oxide electrocatalysts in the applications of the energy storage and conversion.

Dissolved nitrous oxide and emission relating to denitrification across the Poyang Lake aquatic continuum.

Most aquatic ecosystems contribute elevated N2O to atmosphere due to increasing anthropogenic nitrogen loading. To further understand the spatial heterogeneity along an aquatic continuum from the upriver to wetland to lake to downriver, the study was conducted on spatial variations in N2O emission along Poyang Lake aquatic continuum during the flood season from 15 July 2013 to 10 August 2013. The results showed the N2O concentrations, the ratio of N2O/dinitrogen (N2) gases production, N2O emission and denitrification rates ranged from 0.10 to 1.11µgN/L, -0.007% to 0.051%, -9.73 to 127µgN/m2/hr and 1.33×104 to 31.9×104µgN2/m2/hr, respectively, across the continuum. The average N2O concentrations, the ratio of N2O/N2 and N2O emission was significantly lower in wetlands as compared to the rivers and lake (p<0.01). The significantly high denitrification rate and low N2O emission together highlighted that most N2O can be converted into N2 via near complete denitrification in the Poyang Lake wetlands. Our study suggests that the wetlands might impact N2O budget in an integrated aquatic ecosystems. Moreover, N2O emission from different aquatic ecosystem should be considered separately when quantifying the regional budget in aquatic ecosystem.

Recovery of elemental sulfur from zinc concentrate direct leaching residue using atmospheric distillation: a pilot-scale experimental study.

UNLABELLED: Recovery of elemental sulfur from zinc concentrate direct leaching residue (DLR) using atmospheric distillation was systematically investigated on a pilot-scale system for the first time. Batch operating mode was suggested for recovery of elemental sulfur from water-rich DLR using atmospheric distillation. Elemental sulfur with purity higher than 99% was obtained under certain conditions in batch operating mode. With an appropriate feed amount of 1,200 kg, batch experiment conducted at 460 degrees C resulted in sulfur purity of 96.22% and a recovery rate higher than 85%. Only 0.59 and 1.24 kWh power was needed to handle 1.0 kg DLR and produce 1.0 kg elemental sulfur, respectively. The results suggest that recovery of elemental sulfur from zinc concentrate DLR using atmospheric distillation is technologically and economically feasible. Moreover, other metal elements such as zinc were enriched in the distillation concentrate, which could be used for metal refining. Technologies could effectively lower the moisture content of DLR, and lowering the distillation temperature would be of great value for recovery of elemental sulfur from DLR using a distillation method. IMPLICATIONS: Distillation is a promising solution for recovery of elemental sulfur from DLRs. This work revealed the possibility of separation of elemental sulfur from zinc concentrate DLR using atmospheric distillation. Such knowledge is of fundamental importance in developing field-scale separation and purification technologies and devices in which simultaneous sulfur recovery and precious metal enrichment are possible. Important tasks for follow-up research are also suggested.

miR-190 restores the innate immune homeostasis of Drosophila by directly inhibiting Tab2 in Imd pathway.

The Drosophila Imd pathways are well-known mechanisms involved in innate immunity responsible for Gram-negative (G-) bacterial infection. The intensity and durability of immunity need to be finely regulated to keep sufficient immune activation meanwhile avoid excessive immune response. In this study, we firstly demonstrated that miR-190 can downregulate the expression levels of antimicrobial peptides (AMPs) in the Imd immune pathway after Escherichia coli infection using the miR-190 overexpression flies and the miR-190KO/+ flies. Secondly, miR-190 overexpression significantly reduces while miR-190 KO increases Drosophila survival rates upon lethal Enterobacter cloacae infection. Thirdly, we further demonstrated that miR-190 negatively regulates innate immune responses by directly targeting both RA/RB and RC isoforms of Tab2. In addition, the dynamic expression pattern of AMPs (Dpt, AttA, CecA1), miR-190 and Tab2 in the wild-type flies reveals that miR-190 play an important role in Drosophila immune homeostasis restoration at the late stage of E. coli infection. Collectively, our study reveals that miR-190 can downregulate the expression of AMPs by targeting Tab2 and promote immune homeostasis restoration in Drosophila Imd pathway. Our study provides new insights into the regulatory mechanism of animal innate immune homeostasis.

Microbial nitrogen nutrition links to dissolved organic matter properties in East African lakes.

East African lakes, especially soda lakes, are home habitats for massive numbers of wildlife such as flamingos, mammals, and fishes. These lakes are known for their high primary production due to local high temperatures, light intensities, and alkalinity (inorganic carbon). However, these lakes, normally within remote areas, receive low nutrient inputs. Ammonium (NH4+) recycling and/or nitrogen fixation can become the major N supply mechanisms for phytoplankton. However, the driving forces on microbial N nutrition in lakes with minimal anthropogenic disturbance remain poorly understood. Using stable isotope tracer techniques, NH4+ recycling rates were measured in 18 lakes and reservoirs in East Africa (Tanzania and Kenya) during the dry season in early 2020. Three functional genes (nifH, gdh, and ureC) relating to microbial N nutrition were also measured. The regeneration of NH4+ supported up to 71 % of the NH4+ uptake. Positive community biological NH4+ demands (CBAD) for all lakes and reservoirs indicate an obvious N demand from microbial community. Our study provides clear evidence that microbial NH4+ uptake rates linked closely to the dissolved organic matter (DOM) properties (e.g., the absorption coefficient at 254 nm, percents of total fluorescence intensity contributed by microbial humic-like and protein-like components) and that water residence time drives microbial NH4+ recycling by regulating the duration of in-lake DOM processing and influencing algal growth. Phytoplankton, especially those of Cyanophyceae, showed maximum biomass and higher NH4+ recycling rates at a certain range of water residence time (e.g., 5-8 years). However, CBAD showed a decreasing trend with longer water residence time, which may be influenced by changes in the algal community composition (e.g., % Cyanophyceae vs. % Bacillariophyceae). These results indicate that DOM dynamics and the water residence time have the potential to facilitate the understanding of microbial nitrogen supply status in East African lakes.