Hyperon Polarization along the Beam Direction Relative to the Second and Third Harmonic Event Planes in Isobar Collisions at sqrt[s_{NN}]=200 GeV

The polarization of Λ and Λ[over ¯] hyperons along the beam direction has been measured relative to the second and third harmonic event planes in isobar Ru+Ru and Zr+Zr collisions at sqrt[s_{NN}]=200  GeV. This is the first experimental evidence of the hyperon polarization by the triangular flow originating from the initial density fluctuations. The amplitudes of the sine modulation for the second and third harmonic results are comparable in magnitude, increase from central to peripheral collisions, and show a mild p_{T} dependence. The azimuthal angle dependence of the polarization follows the vorticity pattern expected due to elliptic and triangular anisotropic flow, and qualitatively disagrees with most hydrodynamic model calculations based on thermal vorticity and shear induced contributions. The model results based on one of existing implementations of the shear contribution lead to a correct azimuthal angle dependence, but predict centrality and p_{T} dependence that still disagree with experimental measurements. Thus, our results provide stringent constraints on the thermal vorticity and shear-induced contributions to hyperon polarization. Comparison to previous measurements at RHIC and the LHC for the second-order harmonic results shows little dependence on the collision system size and collision energy.

Evolution of point defects in pulsed-laser-melted Ge1-xSnxprobed by positron annihilation lifetime spectroscopy

Direct-band-gap Germanium-Tin alloys (Ge1-xSnx) with high carrier mobilities are promising materials for nano- and optoelectronics. The concentration of open volume defects in the alloy, such as Sn and Ge vacancies, influences the final device performance. In this article, we present an evaluation of the point defects in molecular-beam-epitaxy grown Ge1-xSnxfilms treated by post-growth nanosecond-range pulsed laser melting (PLM). Doppler broadening - variable energy positron annihilation spectroscopy and variable energy positron annihilation lifetime spectroscopy are used to investigate the defect nanostructure in the Ge1-xSnxfilms exposed to increasing laser energy density. The experimental results, supported with ATomic SUPerposition calculations, evidence that after PLM, the average size of the open volume defects increases, which represents a raise in concentration of vacancy agglomerations, but the overall defect density is reduced as a function of the PLM fluence. At the same time, the positron annihilation spectroscopy analysis provides information about dislocations and Ge vacancies decorated by Sn atoms. Moreover, it is shown that the PLM reduces the strain in the layer, while dislocations are responsible for trapping of Sn and formation of small Sn-rich-clusters.

Humic acid-dependent respiratory growth of Methanosarcina acetivorans involves pyrroloquinoline quinone

Although microbial humus respiration plays a critical role in organic matter decomposition and biogeochemical cycling of elements in diverse anoxic environments, the role of methane-producing species (methanogens) is not well defined. Here we report that a major fraction of humus, humic acid reduction enhanced the growth of Methanosarcina acetivorans above that attributed to methanogenesis when utilizing the energy sources methanol or acetate, results which showed both respiratory and fermentative modes of energy conservation. Growth characteristics with methanol were the same for an identically cultured mutant deleted for the gene encoding a multi-heme cytochrome c (MmcA), results indicating MmcA is not essential for respiratory electron transport to humic acid. Transcriptomic analyses revealed that growth with humic acid promoted the upregulation of genes annotated as cell surface pyrroloquinoline quinone (PQQ)-binding proteins. Furthermore, PQQ isolated from the membrane fraction was more abundant in humic acid-respiring cells, and the addition of PQQ improved efficiency of the extracellular electron transport. Given that the PQQ-binding proteins are widely distributed in methanogens, the findings extend current understanding of microbial humus respiration in the context of global methane dynamics.

Identifying the role of array electrodes in improving the compost quality of food waste during electric field-assisted aerobic composting

Low composting temperature and long maturation periods are two major problems during food waste composting. In this study, a novel array-based electric field-assisted aerobic composting (Pin-EAC) process was tested on food waste compost. Pin-EAC increase the composting temperature to 69.3 °C, and improved the germination index by 15%. The Pin-EAC took at least 40% less time to reach the standard compost maturity. The fluorescent spectroscopy results showed that Pin-EAC could increase humic acid and fulvic acid by 33% and 37%, respectively. Pin-EAC could increase the diversity of thermophilic bacteria during composting. The co-occurrence network shown that Pin-EAC are more closely related to oxygen and temperature. This work has initially shown that the use of an electric field could improve food waste composting quality, suggesting that the Pin-EAC process is an effective strategy for high-water and high-oil organic solid waste aerobic composting.

Vanadium in the Environment: Biogeochemistry and Bioremediation

Vanadium(V) is a highly toxic multivalent, redox-sensitive element. It is widely distributed in the environment and employed in various industrial applications. Interactions between V and (micro)organisms have recently garnered considerable attention. This Review discusses the biogeochemical cycling of V and its corresponding bioremediation strategies. Anthropogenic activities have resulted in elevated environmental V concentrations compared to natural emissions. The global distributions of V in the atmosphere, soils, water bodies, and sediments are outlined here, with notable prevalence in Europe. Soluble V(V) predominantly exists in the environment and exhibits high mobility and chemical reactivity. The transport of V within environmental media and across food chains is also discussed. Microbially mediated V transformation is evaluated to shed light on the primary mechanisms underlying microbial V(V) reduction, namely electron transfer and enzymatic catalysis. Additionally, this Review highlights bioremediation strategies by exploring their geochemical influences and technical implementation methods. The identified knowledge gaps include the particulate speciation of V and its associated environmental behaviors as well as the biogeochemical processes of V in marine environments. Finally, challenges for future research are reported, including the screening of V hyperaccumulators and V(V)-reducing microbes and field tests for bioremediation approaches.

[Predictive value of plasma exosomal miR-124-3p for the risk of chronic cerebral hypoperfusion]

Objective: To investigate the predictive value of plasma exosomal microRNA (miR)-124-3p in the risk of chronic cerebral hypoperfusion (CCH). Methods: A case-control study. Thirty patients who were diagnosed with CCH (CCH group) based on cranial artery spin labeling (ASL) in the neurology outpatient clinic of Sichuan Provincial People's Hospital from March 2022 to June 2022 and 30 healthy volunteers (control group) were included. Age, gender, smoking history, alcohol consumption history, diabetes history, hypertension, hyperlipidemia history, uric acid, fasting blood glucose, homocysteine and plasma exosomal miR-124-3p expression level were compared between the two groups. Comparisons of categorical variables were analyzed by either χ2 test or Fisher's exact test. If the data of continuous variables followed a normal distribution, they were expressed as mean±standard deviation (SD) and compared by t-test for two independent samples; otherwise, the data were expressed as M(Q1, Q3), and analyzed by Mann-Whitney U test for comparison between two groups. The correlation between cerebral blood flow and exosomal miR-124-3p levels was analyzed by Pearson's correlation. Binary multifactorial logistic regression analysis was used to determine the risk factors associated with CCH, and corresponding odds ratios (OR) and 95% confidence intervals (CI) were calculated. P<0.05 was considered significant. Results: There was no significant difference in age (64±8 vs. 60±8 years old), gender (33.3% vs. 30.0%), history of smoking (20.0% vs. 3.3%), alcohol consumption (20.0% vs. 6.7%), diabetes mellitus (13.3% vs. 13.3%), hypertension (53.3% vs. 30.0%), history of hyperlipidemia (46.7% vs. 36.7%), uric acid (288±60 vs.319±67 μmol/L), and fasting glucose [4.99(4.63, 5.91) vs. 5.28(5.09, 6.05) mmol/L] and homocysteine [11.35(10.18, 13.08) vs.11.00(9.78, 13.03) μmol/L] between the CCH and control groups (P>0.05). Plasma exosomal miR-124-3p expression was significantly higher in the CCH group than in the control group [13.08 (8.59, 21.55) vs. 2.85 (1.44, 5.10), respectively; U=169.50, P<0.001]. Pearson's correlation test showed that the level of exosomal miR-124-3p was negatively correlated with cerebral blood flow in the hypoperfused region in patients with CCH (r=-0.932, P<0.001). Multi-factor logistic regression analysis showed that plasma exosomal miR-124-3p was independently associated with the risk of CCH (OR=1.169,95%CI 1.063-1.286,P=0.001). Conclusions: The expression of plasma exosomal miR-124-3p is negatively correlated with cerebral blood flow in areas of low perfusion and is an independent risk factor for CCH. Plasma exosomal miR-124-3p may thus serve as a valid biomarker for CCH risk prediction.

[Construction of a schistosomiasis transmission risk assessment system in Wuhan City based on analytic hierarchy process]

OBJECTIVE

To construct a schistosomiasis transmission risk assessment system in Wuhan City and preliminary evaluate its application effect, so as to promote the rational allocation of schistosomiasis control resources and accelerate the progress towards schistosomiasis elimination.

METHODS

The schistosomiasis risk assessment indicators were collected through referring schistosomiasis surveillance data of Wuhan City from 2014 to 2020, literature review and expert interviews. Indicators within each criterion and sub-criterion were screened using the Delphi method, and a hierarchical structure model was created based on analytic hierarchy process. Quantitative assignment of each indicator was conducted according to relative importance, and the weight and combination weight of each criterion were calculated in each analytic hierarchy framework to create a schistosomiasis transmission risk assessment system, which was used for the schistosomiasis transmission risk assessment in 12 national schistosomiasis surveillance sites in Wuhan City.

RESULTS

A three-level schistosomiasis transmission risk assessment system was preliminarily constructed, which included a target layer, 5 criterion layers and 21 sub-criterion layers. Of all indicators in the criterion layer, transmission route had the highest weight (0.433), followed by source of Schistosoma japonicum infection (0.294); and among all indicators in the sub-criterion layer, S. japonicum infection in Oncomelania hupensis and sentinel mice had the highest combination weight (0.125), followed by prevalence of S. japonicum infection in humans (0.091) and bovines (0.053), snail control by chemical treatment (0.049), positive rate of inquiry examinations (0.048), allocation of schistosomiasis control professionals (0.045), and areas of submerged snail-infested settings (0.041). Of the 12 national schistosomiasis surveillance sites in Wuhan City, there were 5 sites with weights of > 0.8, 4 sites with weights of 0.6 to 0.8, and 3 sites with weights of < 0.6 in 2020.

CONCLUSIONS

A schistosomiasis transmission risk assessment system has been constructed based on analytic hierarchy process in Wuhan City, which may provide a evidence-based basis for health resource allocation and decision-making for schistosomiasis control.

Microbial biofilm-based hydrovoltaic technology

Hydrovoltaic electricity generation (HEG) utilizes the latent environmental heat stored in water, and subsequently harvests the electrical energy. However, sustainable HEG has remained extremely challenging due either to complex fabrication and high cost, or to restricted environmental compatibility and renewability. Electroactive microorganisms are environmentally abundant and viable in performing directional electron transport to produce currents. These distinctive features have inspired microbial HEG systems that can convert environmental energy into hygroelectricity upon water circulation from raindrops, waves, and water moisture, and has recently succeeded as proof of concept for becoming a cutting-edge biotechnology. In this review, recent advances in microbial biofilm-based hydrovoltaic technology are highlighted to better understand a promising method of electricity generation from environmental energy with the aim of practical applications.

Information-based continuous nursing on pregnant women with gestational diabetes mellitus

OBJECTIVE

Gestational diabetes mellitus (GDM) is a serious pregnancy complication, and women with undiagnosed diabetes mellitus can develop chronic hyperglycemia during pregnancy. The purpose of this study is to investigate the impact of information-based continuity of care on glucose levels, health awareness, and maternal and infant outcomes in pregnant women with GDM, thereby providing a basis for the clinical implementation of effective interventions for GDM to reduce or avoid adverse outcomes due to GDM.

PATIENTS AND METHODS

One hundred and sixty cases of pregnant women with GDM who underwent treatment in the obstetrics and gynecology department of our hospital from June 2019 to September 2021 were randomly selected as the study population and divided into the control group (n=80) and the study group (n=80). Women in the control group were received with conventional nursing intervention, and those in the study group were obtained with information-based continuity of care on the basis of the control group. Basic clinical data were collected. The levels of fasting blood glucose (FBG), 2h postprandial glucose (2hPG), knowledge of health education, treatment compliance scores, and changes in delivery outcomes were compared between the two groups. According to the maternal blood glucose control level, 160 pregnant women with GDM were divided into the better control group (143 cases) and the poor control group (17 cases). The risk factors affecting the level of maternal glycemic control in gestational diabetes were analyzed.

RESULTS

After the intervention, the levels of FBG and 2hPG were significantly lower in both groups than those before the intervention, while the levels of FBG and 2hPG in the study group were notably lower than those in the control group. The health education knowledge score and treatment compliance score after the intervention were significantly higher than those before the intervention, and the health education knowledge score and treatment compliance score in the study group were observably higher than those in the control group (p<0.01). The adverse pregnancy outcomes of pregnant women in the study group were significantly reduced compared with those in the control group (p<0.05). Logistic regression analysis showed that body mass index (BMI), dietary control, literacy, and information-based continuity of care were all influential factors for maternal glycemic control level (p<0.05). Among the influencing factors, dietary control and continuity of care had clinical value in predicting maternal glycemic control levels in gestational diabetes.

CONCLUSIONS

Continuous nursing based on informatization can effectively control the blood glucose level of pregnant women with GDM, improve the treatment compliance of pregnant women and the awareness rate of gestational diabetes knowledge so as to reduce the occurrence of adverse pregnancy outcomes and improve the health level. In addition, BMI and dietary control are independent risk factors that affect the blood glucose control level of pregnant women. Relevant intervention measures should be formulated according to the relevant influencing factors to effectively control the blood glucose level of pregnant women with GDM and improve maternal and infant outcomes.

Black soldier fly pretreatment promotes humification and phosphorus activation during food waste composting

Black soldier fly (BSF) and thermophilic composting (TC) treatments are commonly adopted to manage food waste. In this study, 30 days of TC of food waste following seven days BSF pretreatment (BC) was compared to 37 days of TC of food waste (TC, the control). Fluorescence spectrum and 16S rRNA high-throughput sequencing analysis were used to compare the BC and TC treatments. Results showed that BC could decrease protein-like substances and increase humus substances more quickly, and that the humification index of compost products was 106.8% higher than that of TC, suggesting that the humification process was accelerated by BSF pretreatment resulting in a 21.6% shorter maturity time. Meanwhile, the concentrations of total and available phosphorus rose from 7.2 and 3.3 g kg-1 to 44.2 and 5.5 g kg-1, respectively, which were 90.5% and 118.8% higher in compost products from BC as compared to those in TC. Furthermore, BC had higher richness and diversity of humus synthesis and phosphate-solubilizing bacteria (PSB), with Nocardiopsis (53.8%) and Pseudomonas (47.0%) being the dominant PSB. Correlation analysis demonstrated that the introduction of BSF gut bacteria contributed to the effectiveness of related functional bacteria, resulting in a rapid humification process and phosphorus activation. Our findings advance understanding of the humification process and provide novel perspectives on food waste management.

Combining biological denitrification and electricity generation in methane-powered microbial fuel cells

Methane has been demonstrated to be a feasible substrate for electricity generation in microbial fuel cells (MFCs) and denitrifying anaerobic methane oxidation (DAMO). However, these two processes were evaluated separately in previous studies and it has remained unknown whether methane is able to simultaneously drive these processes. Here we investigated the co-occurrence and performance of these two processes in the anodic chamber of MFCs. The results showed that methane successfully fueled both electrogenesis and denitrification. Importantly, the maximum nitrate removal rate was significantly enhanced from (1.4 ± 0.8) to (18.4 ± 1.2) mg N/(L·day) by an electrogenic process. In the presence of DAMO, the MFCs achieved a maximum voltage of 610 mV and a maximum power density of 143 ± 12 mW/m². Electrochemical analyses demonstrated that some redox substances (e.g. riboflavin) were likely involved in electrogenesis and also in the denitrification process. High-throughput sequencing indicated that the methanogen Methanobacterium, a close relative of Methanobacterium espanolae, catalyzed methane oxidation and cooperated with both exoelectrogens and denitrifiers (e.g., Azoarcus). This work provides an effective strategy for improving DAMO in methane-powered MFCs, and suggests that methanogens and denitrifiers may jointly be able to provide an alternative to archaeal DAMO for methane-dependent denitrification.

[Comparison of the effects and safety of dydrogesterone and medroxyprogesterone acetate on endometrial hyperplasia without atypia: a randomized controlled non-inferior phase Ⅲ clinical study]

Objective: To compare the effects and safety of dydrogesterone (DG) and medroxyprogesterone acetate (MPA) on the treatment in patients with endometrial hyperplasia without atypia (EH). Methods: This was a single-center, open-label, prospective non-inferior randomized controlled phase Ⅲ trial. From February 2019 to November 2021, patients with EH admitted to the Obstetrics and Gynecology Hospital of Fudan University were recruited. Enrolled patients were stratified according to the pathological types of simple hyperplasia (SH) or complex hyperplasia (CH), and were randomised to receive MPA or DG. Untill May 14, 2022, the median follow-up time after complete response (CR) was 9.3 months (1.1-17.2 months). The primary endpoint was the 6-month CR rate (6m-CR rate). The secondary endpoints included the 3-month CR rate (3m-CR rate), adverse events rate, recurrence rate, and pregnancy rate in one year after CR. Results: (1) A total of 292 patients with EH were enrolled in the study with the median age of 39 years (31-45 years). A total of 135 SH patients were randomly assigned to MPA group (n=67) and DG group (n=68), and 157 CH patients were randomly assigned to MPA group (n=79) and DG group (n=78). (2) Among 292 patients, 205 patients enrolled into the primary endpoint analysis, including 92 SH patients and 113 CH patients, with 100 patients in MPA group and 105 in DG group, respectively. The 6m-CR rate of MPA group and DG group were 90.0% (90/100) and 88.6% (93/105) respectively, and there were no statistical significance (χ²=0.11, P=0.741), with the rate difference (RD) was -1.4% (95%CI:-9.9%-7.0%). Stratified by the pathology types, the 6m-CR rate of SH patients was 93.5% (86/92), and MPA group and DG group were respectively 91.1% (41/45) and 95.7% (45/47); and the 6m-CR rate of CH patients was 85.8% (97/113), and MPA group and DG group were 89.1% (49/55) and 82.8% (48/58) respectively. The 6m-CR rates of the two treatments had no statistical significance either (all P>0.05). A total of 194 EH patients enrolled into the secondary endpoint analysis, including 88 SH patients and 106 CH patients, and 96 patients in MPA group and 98 in DG group, respectively. The 3m-CR rate of SH patients were 87.5% (77/88), while the 3m-CR rates of MPA group and DG group were 90.7% (39/43) and 84.4% (38/45), respectively; the 3m-CR rate of CH patients was 66.0% (70/106), and MPA group and DG group had the same 3m-CR rate of 66.0% (35/53). No statistical significance was found between the two treatments both in SH and CH patients (all P>0.05). (3) The incidence of adverse events between MPA group and DG group had no statistical significance (P>0.05). (4) A total of 93 SH patients achieved CR, and the cumulative recurrence rate in one year after CR were 5.9% and 0 in MPA group and DG group, respectively. While 112 CH patients achieved CR, and the cumulative recurrence rate in one year after CR were 8.8% and 6.5% in MPA group and DG group, respectively. There were no statistical significance between two treatment groups (all P>0.05). Among the 93 SH patients, 10 patients had family planning but no pregnancy happened during the follow-up period. Among the 112 CH patients, 21 were actively preparing for pregnancy, and the pregnancy rate and live-birth rate in one year after CR in MPA group were 7/9 and 2/7, while in DG group were respectively 4/12 and 2/4, and there were no statistical significance in pregnancy rate and live-birth rate between the two treatment groups (all P>0.05). Conclusions: Compared with MPA, DG is of good efficacy and safety in treating EH. DG is a favorable alternative treatment for EH patients.

May microbial ecological baseline exist in continental groundwater?

BACKGROUND

Microbes constitute almost the entire biological community in subsurface groundwater and play an important role in ecological evolution and global biogeochemical cycles. Ecological baseline as a fundamental reference with less human interference has been investigated in surface ecosystems such as soils, rivers, and ocean, but the existence of groundwater microbial ecological baseline (GMEB) is still an open question so far.

RESULTS

Based on high-throughput sequencing information derived from national monitoring of 733 newly constructed wells, we find that bacterial communities in pristine groundwater exhibit a significant lateral diversity gradient and gradually approach the topsoil microbial latitudinal diversity gradient with decreasing burial depth of phreatic water. Among 74 phyla dominated by Proteobacteria in groundwater, Patescibacteria act as keystone taxa that harmonize microbes in shallower aquifers and accelerate decline in bacterial diversity with increasing well-depth. Decreasing habitat niche breadth with increasing well-depth suggests a general change in the relationship among key microbes from closer cooperation in shallow to stronger competition in deep groundwater. Unlike surface-water microbes, microbial communities in pristine groundwater are predominantly shaped by deterministic processes, potentially associated with nutrient sequestration under dark and anoxic environments in aquifers.

CONCLUSIONS

By unveiling the biogeographic patterns and mechanisms controlling the community assembly of microbes in pristine groundwater throughout China, we firstly confirm the existence of GMEB in shallower aquifers and propose Groundwater Microbial Community Index (GMCI) to evaluate anthropogenic impact, which highlights the importance of GMEB in groundwater water security and health diagnosis. Video Abstract.

Southern ocean carbon and heat impact on climate

The Southern Ocean greatly contributes to the regulation of the global climate by controlling important heat and carbon exchanges between the atmosphere and the ocean. Rates of climate change on decadal timescales are therefore impacted by oceanic processes taking place in the Southern Ocean, yet too little is known about these processes. Limitations come both from the lack of observations in this extreme environment and its inherent sensitivity to intermittent processes at scales that are not well captured in current Earth system models. The Southern Ocean Carbon and Heat Impact on Climate programme was launched to address this knowledge gap, with the overall objective to understand and quantify variability of heat and carbon budgets in the Southern Ocean through an investigation of the key physical processes controlling exchanges between the atmosphere, ocean and sea ice using a combination of observational and modelling approaches. Here, we provide a brief overview of the programme, as well as a summary of some of the scientific progress achieved during its first half. Advances range from new evidence of the importance of specific processes in Southern Ocean ventilation rate (e.g. storm-induced turbulence, sea-ice meltwater fronts, wind-induced gyre circulation, dense shelf water formation and abyssal mixing) to refined descriptions of the physical changes currently ongoing in the Southern Ocean and of their link with global climate. This article is part of a discussion meeting issue 'Heat and carbon uptake in the Southern Ocean: the state of the art and future priorities'.

Measurements of the Elliptic and Triangular Azimuthal Anisotropies in Central ^{3}He+Au, d+Au and p+Au Collisions at sqrt[s_{NN}]=200 GeV

The elliptic (v_{2}) and triangular (v_{3}) azimuthal anisotropy coefficients in central ^{3}He+Au, d+Au, and p+Au collisions at sqrt[s_{NN}]=200  GeV are measured as a function of transverse momentum (p_{T}) at midrapidity (|η|<0.9), via the azimuthal angular correlation between two particles both at |η|<0.9. While the v_{2}(p_{T}) values depend on the colliding systems, the v_{3}(p_{T}) values are system independent within the uncertainties, suggesting an influence on eccentricity from subnucleonic fluctuations in these small-sized systems. These results also provide stringent constraints for the hydrodynamic modeling of these systems.

Structure, stability, and potential function of groundwater microbial community responses to permafrost degradation on varying permafrost of the Qinghai-Tibet Plateau

The ongoing permafrost degradation under climate warming has modified aboveground biogeochemical processes mediated by microbes, yet groundwater microbial structure and function as well as their response to permafrost degradation remain poorly understood. We separately collect 20 and 22 sub-permafrost groundwater samples from Qilian Mountain (alpine and seasonal permafrost) and Southern Tibet Valley (plateau isolated permafrost) on the Qinghai-Tibet Plateau (QTP) to investigate the effects of permafrost groundwater characteristics on the diversity, structure, stability, and potential function of bacterial and fungal communities. Regional discrepancy of groundwater microbes between two permafrost regions reveals that permafrost degradation might reshape microbial community structure, increase community stability and potential functions relevant to carbon metabolism. Bacterial community assembly in permafrost groundwater is governed by deterministic processes, whereas fungal communities are mainly controlled by stochastic processes, suggesting that bacterial biomarkers might provide the better 'early warning signals' to permafrost degradation in deeper layers. Our study highlights the importance of groundwater microbes in ecological stability and carbon emission on the QTP.

Observation of Directed Flow of Hypernuclei _{Λ}^{3}H and _{Λ}^{4}H in sqrt[s_{NN}]=3 GeV Au+Au Collisions at RHIC

We report here the first observation of directed flow (v_{1}) of the hypernuclei _{Λ}^{3}H and _{Λ}^{4}H in mid-central Au+Au collisions at sqrt[s_{NN}]=3  GeV at RHIC. These data are taken as part of the beam energy scan program carried out by the STAR experiment. From 165×10^{6} events in 5%-40% centrality, about 8400 _{Λ}^{3}H and 5200 _{Λ}^{4}H candidates are reconstructed through two- and three-body decay channels. We observe that these hypernuclei exhibit significant directed flow. Comparing to that of light nuclei, it is found that the midrapidity v_{1} slopes of _{Λ}^{3}H and _{Λ}^{4}H follow baryon number scaling, implying that the coalescence is the dominant mechanism for these hypernuclei production in the 3 GeV Au+Au collisions.

Sunlight Significantly Enhances Soil Denitrification via an Interfacial Biophotoelectrochemical Pathway

Denitrification is an essential step of the nitrogen cycle in soil. However, although sunlight is an important environmental factor for soil, the investigation of the influence of sunlight on soil denitrification is limited to plant photosynthesis-mediated processes. Herein, a new pathway, denoted as a biophotoelectrochemical process, which is induced by the direct photoexcitation of soil, was found to greatly enhance soil denitrification. Using red soil as the research object, the soil with irradiation showed nitrate reduction that was 2.6-4.7 times faster than that without irradiation. The irradiation of soil accelerated the reduction of nitrite and enhanced the conversion of nitrous oxide to nitrogen, indicating that more electron sources were generated. This resulted from the photoinduced generation of ferrous substrates and photoelectrons. The contribution of irradiation to soil denitrification was almost half (45.4%), of which 30.9% was from photoinduced ferrous substrates and 14.5% was from photoelectrons. Moreover, a designed biophotoelectrochemical cell provided solid evidence for direct photoelectron transfer from soil photosensitive substrates to microorganisms. Irradiation promoted the enrichment of Alicyclobacillus, which participates in iron oxidation and electroautotrophy. This finding reveals a role of sunlight in soil denitrification that has been thus seriously overlooked and provides solid evidence for the natural occurrence of photoelectrotrophic effects.

Beam Energy Dependence of Triton Production and Yield Ratio (N_{t}×N_{p}/N_{d}^{2}) in Au+Au Collisions at RHIC

We report the triton (t) production in midrapidity (|y|<0.5) Au+Au collisions at sqrt[s_{NN}]=7.7-200  GeV measured by the STAR experiment from the first phase of the beam energy scan at the Relativistic Heavy Ion Collider. The nuclear compound yield ratio (N_{t}×N_{p}/N_{d}^{2}), which is predicted to be sensitive to the fluctuation of local neutron density, is observed to decrease monotonically with increasing charged-particle multiplicity (dN_{ch}/dη) and follows a scaling behavior. The dN_{ch}/dη dependence of the yield ratio is compared to calculations from coalescence and thermal models. Enhancements in the yield ratios relative to the coalescence baseline are observed in the 0%-10% most central collisions at 19.6 and 27 GeV, with a significance of 2.3σ and 3.4σ, respectively, giving a combined significance of 4.1σ. The enhancements are not observed in peripheral collisions or model calculations without critical fluctuation, and decreases with a smaller p_{T} acceptance. The physics implications of these results on the QCD phase structure and the production mechanism of light nuclei in heavy-ion collisions are discussed.

Lysogenic bacteriophages encoding arsenic resistance determinants promote bacterial community adaptation to arsenic toxicity

Emerging evidence from genomics gives us a glimpse into the potential contribution of lysogenic bacteriophages (phages) to the environmental adaptability of their hosts. However, it is challenging to quantify this kind of contribution due to the lack of appropriate genetic markers and the associated controllable environmental factors. Here, based on the unique transformable nature of arsenic (the controllable environmental factor), a series of flooding microcosms was established to investigate the contribution of arsM-bearing lysogenic phages to their hosts' adaptation to trivalent arsenic [As(III)] toxicity, where arsM is the marker gene associated with microbial As(III) detoxification. In the 15-day flooding period, the concentration of As(III) was significantly increased, and this elevated As(III) toxicity visibly inhibited the bacterial population, but the latter quickly adapted to As(III) toxicity. During the flooding period, some lysogenic phages re-infected new hosts after an early burst, while others persistently followed the productive cycle (i.e., lytic cycle). The unique phage-host interplay contributed to the rapid spread of arsM among soil microbiota, enabling the quick recovery of the bacterial community. Moreover, the higher abundance of arsM imparted a greater arsenic methylation capability to soil microbiota. Collectively, this study provides experimental evidence for lysogenic phages assisting their hosts in adapting to an extreme environment, which highlights the ecological perspectives on lysogenic phage-host mutualism.

Reactive Oxygen Species Triggered Oxidative Degradation of Polystyrene in the Gut of Superworms (Zophobas atratus Larvae)

Oxidative decomposition of polystyrene (PS) by insects has been previously demonstrated, yet little is known about the oxidation mechanism and its effect on the metabolism of plastics within the insect gut. Here, we demonstrate the generation of reactive oxygen species (ROS) in the gut of superworms (Zophobas atratus larvae) under different feeding trails, which in turn induced the oxidative decomposition of ingested PS. The ROS were commonly generated in the larva gut, and PS consumption resulted in a significant increase of ROS with a maximum ·OH of 51.2 μmol/kg, which was five times higher than in the bran feeding group. Importantly, scavenging of ROS significantly decreased the oxidative depolymerization of PS, indicating a vital role of ROS in effective PS degradation in the gut of superworms. Further investigation suggested that the oxidative depolymerization of PS was caused by the combinatorial effect of ROS and extracellular oxidases of gut microbes. These results demonstrate that ROS were extensively produced within the intestinal microenvironment of insect larvae, which greatly favored the digestion of ingested bio-refractory polymers. This work provides new insights into the underlying biochemical mechanisms of plastic degradation in the gut.

Enhanced degradation of microplastics during sludge composting via microbially-driven Fenton reaction

It has been increasingly documented that the hydroxyl radical (•OH) can promote the transformation of organic contaminants such as microplastics (MPs) in various environments. However, few studies have sought to identify an ideal strategy for accelerating in situ MPs degradation through boosting the process of •OH production in practical applications. In this work, iron-mineral-supplemented thermophilic composting (imTC) is proposed and demonstrated for enhancing in situ degradation of sludge-based MPs through strengthening •OH generation. The results show that the reduction efficiency of sludge-based MPs abundance was about 35.93% in imTC after treatment for 36 days, which was 38.99% higher than that of ordinary thermophilic composting (oTC). Further investigation on polyethylene-microplastics (PE-MPs) suggested that higher abundance of •OH (the maximum value was 408.1 μmol·kg^-1) could be detected on the MPs isolated from imTC through microbially-mediated redox transformation of iron oxides, as compared to oTC. Analyses of the physicochemical properties of the composted PE-MPs indicated that increased •OH generation could largely accelerate the oxidative degradation of MPs. This work, for the first time, proposes a feasible strategy to enhance the reduction efficiency of MPs abundance during composting through the regulation of •OH production.

Biophotoelectrochemical process co-driven by dead microalgae and live bacteria

Anaerobic reduction processes in natural waters can be promoted by dead microalgae that have been attributed to nutrient substances provided by the decomposition of dead microalgae for other microorganisms. However, previous reports have not considered that dead microalgae may also serve as photosensitizers to drive microbial reduction processes. Here we demonstrate a photoelectric synergistic linkage between dead microalgae and bacteria capable of extracellular electron transfer (EET). Illumination of dead Raphidocelis subcapitata resulted in two-fold increase in the rate of anaerobic bioreduction by pure Geobacter sulfurreducens, suggesting that photoelectrons generated from the illuminated dead microalgae were transferred to the EET-capable microorganisms. Similar phenomena were observed in NO3- reduction driven by irradiated dead Chlorella vulgaris and living Shewanella oneidensis, and Cr(VI) reduction driven by irradiated dead Raphidocelis subcapitata and living Bacillus subtilis. Enhancement of bioreduction was also seen when the killed microalgae were illuminated in mixed-culture lake water, suggesting that EET-capable bacteria were naturally present and this phenomenon is common in post-bloom systems. The intracellular ferredoxin-NADP+-reductase is inactivated in the dead microalgae, allowing the production and extracellular transfer of photoelectrons. The use of mutant strains confirmed that the electron transport pathway requires multiheme cytochromes. Taken together, these results suggest a heretofore overlooked biophotoelectrochemical process jointly mediated by illumination of dead microalgae and live EET-capable bacteria in natural ecosystems, which may add an important component in the energetics of bioreduction phenomena particularly in microalgae-enriched environments.