Enhancing water quality and ecosystems of reclaimed water-replenished river: A case study of Dongsha River, Beijing, China

The use of reclaimed water for urban river replenishment has raised concerns regarding its impact on water quality and aquatic ecosystems. This study aims to reveal the improvements seen in an urban river undergoing a practical water eco-remediation after being replenished with reclaimed water. A one-year monitoring of water quality, phytoplankton, and zooplankton was carried out in Dongsha River undergoing eco-remediation in Beijing, China. The results showed that compared to the unrestored river, the concentrations of COD, NH4+-N, TP, and TN decreased by 28.22 ± 7.88 %, 40.24 ± 11.77 %, 44.17 ± 17.29 %, and 28.66 ± 10.39 % in the restoration project area, respectively. The concentration of Chlorophyll-a in the restoration area was maintained below 40 μg/L. During summer, when algal growth is vigorous, the density of Cyanophyta in the unrestored river decreased from 46.84 × 104cells/L to 16.32 × 104cells/L in the restored area, while that of Chlorophyta decreased from 41.61 × 104cells/L to 11.87 × 104cells/L, a reduction of 65.16 % and 71.47 %, respectively. The dominant phytoplankton species were replaced with Bacillariophyta, such as Synedra sp. and Nitzschia sp., indicating that the restoration of aquatic plants reduces the risk of Cyanophyta blooms. Zooplankton species also changed in the restoration area, especially during summer. The density of pollution-tolerant Rotifer and Protozoa decreased by 31.06 % and 27.22 %, while the density of clean water indicating Cladocera increased by 101.19 %. We further calculated the diversity and evenness index of phytoplankton and zooplankton within and outside the restoration area. The results showed that the Shannon-Weaver index for phytoplankton and zooplankton in the restoration area was 2.1 and 1.91, which was higher than those in the river (1.84 and 1.82). This further confirmed that aquatic plant restoration has positive effects. This study can provide a practical reference and theoretical basis for the implementation of water ecological restoration projects in other reclaimed water rivers in China.

A novel electro-Fenton hybrid system for enhancing the interception of volatile organic compounds in membrane distillation desalination

Membrane distillation (MD) is a promising alternative desalination technology, but the hydrophobic membrane cannot intercept volatile organic compounds (VOCs), resulting in aggravation in the quality of permeate. In term of this, electro-Fenton (EF) was coupled with sweeping gas membrane distillation (SGMD) in a more efficient way to construct an advanced oxidation barrier at the gas-liquid interface, so that the VOCs could be trapped in this layer to guarantee the water quality of the distillate. During the so-called EF-MD process, an interfacial interception barrier containing hydroxyl radical formed on the hydrophobic membrane surface. It contributed to the high phenol rejection of 90.2% with the permeate phenol concentration lower than 1.50 mg/L. Effective interceptions can be achieved in a wide temperature range, even though the permeate flux of phenol was also intensified. The EF-MD system was robust to high salinity and could electrochemically regenerate ferrous ions, which endowed the long-term stability of the system. This novel EF-MD configuration proposed a valuable strategy to intercept VOCs in MD and will broaden the application of MD in hypersaline wastewater treatment.

Mechanistic Investigation into Single-Electron Oxidative Addition of Single-Atom Cu(I)-N4 Site: Revealing the Cu(I)-Cu(II)-Cu(I) Catalytic Cycle in Photochemical Hydrophosphinylation

Understanding the valency and structural variations of metal centers during reactions is important for mechanistic studies of single-atom catalysis, which could be beneficial for optimizing reactions and designing new protocols. Herein, we precisely developed a single-atom Cu(I)-N4 site catalyst via a photoinduced ligand exchange (PILE) strategy. The low-valent and electron-rich copper species could catalyze hydrophosphinylation via a novel single-electron oxidative addition (OA) pathway under light irradiation, which could considerably decrease the energy barrier compared with the well-known hydrogen atom transfer (HAT) and single electron transfer (SET) processes. The Cu(I)-Cu(II)-Cu(I) catalytic cycle, via single-electron oxidative addition and photoreduction, has been proven by multiple in situ or operando techniques. This catalytic system demonstrates high efficiency and requires room temperature conditions and no additives, which improves the turnover frequency (TOF) to 1507 h-1. In particular, this unique mechanism has broken through the substrate limitation and shows a broad scope for different electronic effects of alkenes and alkynes.

An improved differential evolution algorithm for multi-modal multi-objective optimization

Multi-modal multi-objective problems (MMOPs) have gained much attention during the last decade. These problems have two or more global or local Pareto optimal sets (PSs), some of which map to the same Pareto front (PF). This article presents a new affinity propagation clustering (APC) method based on the Multi-modal multi-objective differential evolution (MMODE) algorithm, called MMODE_AP, for the suit of CEC'2020 benchmark functions. First, two adaptive mutation strategies are adopted to balance exploration and exploitation and improve the diversity in the evolution process. Then, the affinity propagation clustering method is adopted to define the crowding degree in decision space (DS) and objective space (OS). Meanwhile, the non-dominated sorting scheme incorporates a particular crowding distance to truncate the population during the environmental selection process, which can obtain well-distributed solutions in both DS and OS. Moreover, the local PF membership of the solution is defined, and a predefined parameter is introduced to maintain of the local PSs and solutions around the global PS. Finally, the proposed algorithm is implemented on the suit of CEC'2020 benchmark functions for comparison with some MMODE algorithms. According to the experimental study results, the proposed MMODE_AP algorithm has about 20 better performance results on benchmark functions compared to its competitors in terms of reciprocal of Pareto sets proximity (rPSP), inverted generational distances (IGD) in the decision (IGDX) and objective (IGDF). The proposed algorithm can efficiently achieve the two goals, i.e., the convergence to the true local and global Pareto fronts along with better distributed Pareto solutions on the Pareto fronts.

Occurrence of iodinated contrast media (ICM) in water environments and their control strategies with a particular focus on iodinated by-products formation: A comprehensive review

Iodinated contrast media (ICM), one of the pharmaceutical and personal care products (PPCPs), are frequently detected in various water bodies due to the strong biochemical stability and recalcitrance to conventional water treatment. Additionally, ICM pose a risk of forming iodinated by-products that can be detrimental to the aquatic ecosystem. Consequently, effectively removing ICM from aqueous environments is a significant concern for environmental researchers. This article provides a comprehensive review of the structural characteristics of ICM, their primary source (e.g., domestic and hospital wastewater), detected concentrations in water environments, and ecological health hazards associated with them. The current wastewater treatment technologies for ICM control are also reviewed in detail with the aim of providing a reference for future research. Prior researches have demonstrated that traditional treatment processes (such as physical adsorption, biochemical method and chemical oxidation method) have inadequate efficiencies in the removal of ICM. Currently, the application of advanced oxidation processes to remove ICM has become extensive, but there are some issues like poor deiodination efficiency and the risk of forming toxic intermediates or iodinated by-products. Conversely, reduction technologies have a high deiodination rate, enabling the targeted removal of ICM. But the subsequent treatment issues related to iodine (such as I- and OI-) are often underestimated, potentially generating iodinated by-products during the subsequent treatment processes. Hence, we proposed using combined reduction-oxidation technologies to remove ICM and achieved synchronous control of iodinated by-products. In the future, it is recommended to study the degradation efficiency of ICM and the control efficiency of iodinated by-products by combining different reduction and oxidation processes.

Unequivocal Identification of Spin-Triplet and Spin-Singlet Superconductors with Upper Critical Field and Flux Quantization

Spin-triplet superconductors play central roles in Majorana physics and quantum computing but are difficult to identify. We show the methods of kink-point upper critical field and flux quantization in superconducting rings can unequivocally identify spin-singlet, spin-triplet in centrosymmetric superconductors, and singlet-triplet admixture in noncentrosymmetric superconductors, as realized in γ-BiPd, β-Bi_{2}Pd, and α-BiPd, respectively. Our findings are essential for identifying triplet superconductors and exploring their quantum properties.

Synthesis of Multiple Emission Carbon Dots from Dihydroxybenzoic Acid via Decarboxylation Process

Carbon dots (CDs), as a new zero-dimensional carbon-based nanomaterial with desirable optical properties, exhibit great potential for many application fields. However, the preparation technique of multiple emission CDs with high yield is difficult and complex. Therefore, exploring the large-scale and straightforward synthesis of multicolor CDs from a simple carbon source is necessary. In this work, the solvent-free method prepares a series of multicolor emission CDs from dihydroxybenzoic acid (DHBA). The maximum emission wavelengths are 408, 445, 553, 580, and 610 nm, respectively, covering the visible light region. The 2,4- and 2,6-CDs possess the longer emission wavelength caused by the 2,4-, and 2,6-DHBA easily undergo decarboxylation to form the larger sp² domain graphitized structure. These CDs incorporated with g-C₃N₄ can significantly improve the photocatalytic water-splitting hydrogen production rate by extending the visible light absorption and enhancing the charge separation efficiency. The long-wavelength emission CDs can further enhance photocatalytic activity primarily by improving visible light absorption efficiency.

A new insight into the low membrane fouling tendency of liquid-liquid hollow fiber membrane contactor capturing ammonia from human urine

To unravel the low membrane fouling tendency and underlying membrane fouling mechanism of liquid-liquid hollow fiber membrane contactor (LL-HFMC) capturing ammonia from human urine, the ammonia flux decline trend, membrane fouling propensity, foulant-membrane thermodynamic interaction energy and microscale force analysis at different feed urine pH were comprehensively investigated. The 21-d continuous experiments showed that the ammonia flux decline trend and membrane fouling propensity significantly strengthened with the decrease of feed urine pH. The calculated foulant-membrane thermodynamic interaction energy decreased with the decreasing feed urine pH and agreed with the ammonia flux decline trend and membrane fouling propensity. The microscale force analysis showed that the absence of hydrodynamic water permeate drag force resulted in the foulant located at long distance from the membrane were difficult to approach the membrane surface, thus considerably alleviating membrane fouling. Additionally, the vital thermodynamic attractive force near the membrane surface increased with the decrease of feed urine pH, which made the membrane fouling further relieved at high pH condition. Therefore, the absence of water permeate drag force and operating at high pH condition minimized the membrane fouling during the LL-HFMC ammonia capture process. The obtained results provide a new insight into the low membrane tendency mechanism of LL-HFMC.

The Formation Process and Mechanism of Carbon Dots Prepared from Aromatic Compounds as Precursors: A Review

Fluorescent carbon dots are a novel type of nanomaterial. Due to their excellent optical properties, they have extensive application prospects in many fields. Studying the formation process and fluorescence mechanism of CDs will assist scientists in understanding the synthesis of CDs and guide more profound applications. Due to their conjugated structures, aromatic compounds have been continuously used to synthesize CDs, with emissions ranging from blue to NIR. There is a lack of a systematic summary of the formation process and fluorescence mechanism of aromatic precursors to form CDs. In this review, the formation process of CDs is first categorized into three main classes according to the precursor types of aromatic compounds: amines, phenols, and polycyclics. And then, the fluorescence mechanism of CDs synthesized from aromatic compounds is summarized. The challenges and prospects are proposed in the last section.

Perchlorate removal by a combined heterotrophic and bio-electrochemical hydrogen autotrophic system

Here, a novel combined heterotrophic and bio-electrochemical hydrogen autotrophic (CHBHA) system was developed to remove perchlorate under low chemical dosages and energy consumption. The perchlorate removal performance at various hydraulic retention times (HRTs) and acetate dosages was investigated. For influent containing 10 ± 0.10 mg/L perchlorate, the optimal removal efficiency by the CHBHA system was 98.96 ± 1.62 %, 92.99 ± 2.99 %, 97.85 ± 0.41 %, and 98.24 ± 1.56 % at different operating stages. Perchlorate was mainly removed in the heterotrophic part (H-part) at a sufficient HRT (6 h) and acetate dosage (14.75 mg/L). At other stages, perchlorate was synergistically removed by the H-part and electrochemical hydrogen autotrophic part (E-part). Since the H-part removed some perchlorate, the E-part's applied current decreased, thus reducing energy costs. The maximum current efficiency of CHBHA system was 22.09 %. Compared with the single E-part system, the combined system used 65 % less energy. Perchlorate was converted into active chlorine in the E-part, which improved the effluent quality. The bacterial community structures of the two parts were significantly different. Comamonas, Dechloromonas, Acinetobacter, and Chryseobacterium were enriched in the H-part, and the dominant genera in the E-part were Thauera, Azonexus, Hydrogenophaga, and Tissierella.

Formation and fluorescent mechanism of red emissive carbon dots from o-phenylenediamine and catechol system

Carbon dots (CDs) as the advancing fluorescent carbon nanomaterial have superior potential and prospective. However, the ambiguous photoluminescence (PL) mechanism and intricate structure-function relationship become the greatest hindrances in the development and applications of CDs. Herein, red emissive CDs were synthesized in high yield from o-phenylenediamine (oPD) and catechol (CAT). The PL mechanism of the CDs is considered as the molecular state fluorophores because 5,14-dihydroquinoxalino[2,3-b] phenazine (DHQP) is separated and exhibits the same PL properties and behavior as the CDs. These include the peak position and shape of the PL emission and PL excitation and the emission dependence on pH and solvent polarity. Both of them display close PL lifetime decays. Based on these, we deduce that DHQP is the fluorophore of the red emissive CDs and the PL mechanism of CDs is similar to DHQP. During the PL emission of CDs, the electron of the molecule state can transfer to CDs. The formation process of DHQP is further confirmed by the reaction intermediates (phthalazine, dimers) and oPD. These findings provide insights into the PL mechanism of this type of CDs and may guide the further development of tunable CDs for tailored properties.

Effects of airflow rate distribution and nitrobenzene removal in an aquifer with a low-permeability lens during surfactant-enhanced air sparging

The application of surfactant-enhanced air sparging (SEAS) in heterogeneous aquifers has received increasing attention. In this study, a two-dimensional laboratory visualization device was used to study the migration and distribution mechanism of airflow and the nitrobenzene removal effect in an aquifer with a low-permeability lens during AS and SEAS. Experimental results showed that the surfactant significantly reduced the blocking effect of the geological interface on airflow, and the ΔP_e (the air entry pressure difference between the background media and the lens) value of the geological interface decreased from 1.1 kPa to 0.3 kPa when the surfactant concentration was 800 mg/L. When the surfactant injection location was at the center of the lens and the injection volume was 1 PV (pore volume of the lens), part of the airflow entered the lens through its below interface, which clearly improved the nitrobenzene removal inside and above the lens compared with AS remediation. However, when SEAS remediation was 24 h, the surfactant redistribution caused by air sparging resulted in the airflow entering the lens to bypass the lens again, which changed the spatial distribution of airflow rate and was not conducive to the continuous removal of nitrobenzene inside the lens.

Restoration of Autophagic Flux Improves Endothelial Function in Diabetes Through Lowering Mitochondrial ROS-Mediated eNOS Monomerization

Endothelial nitric oxide synthase (eNOS) monomerization and uncoupling play crucial roles in mediating vascular dysfunction in diabetes, although the underlying mechanisms are still incompletely understood. Increasing evidence indicates that autophagic dysregulation is involved in the pathogenesis of diabetic endothelial dysfunction; however, whether autophagy regulates eNOS activity through controlling eNOS monomerization or dimerization remains elusive. In this study, autophagic flux was impaired in the endothelium of diabetic db/db mice and in human endothelial cells exposed to advanced glycation end products or oxidized low-density lipoprotein. Inhibition of autophagic flux by chloroquine or bafilomycin A1 were sufficient to induce eNOS monomerization and lower nitric oxide bioavailability by increasing mitochondrial reactive oxygen species (mtROS). Restoration of autophagic flux by overexpressing transcription factor EB (TFEB), a master regulator of autophagy and lysosomal biogenesis, decreased endothelial cell oxidative stress, increased eNOS dimerization, and improved endothelium-dependent relaxations (EDRs) in db/db mouse aortas. Inhibition of mammalian target of rapamycin kinase (mTOR) increased TFEB nuclear localization, reduced mtROS accumulation, facilitated eNOS dimerization, and enhanced EDR in db/db mice. Moreover, calorie restriction also increased TFEB expression, improved autophagic flux, and restored EDR in the aortas of db/db mice. Taken together, the findings of this study reveal that mtROS-induced eNOS monomerization is closely associated with the impaired TFEB-autophagic flux axis leading to endothelial dysfunction in diabetic mice.

[Clinical characteristics of human adenovirus infection in hospitalized children with acute respiratory infection in Beijing]

Objective: To compare the clinical characteristics of different types of human adenovirus (HAdV) infection in hospitalized children with acute respiratory infection in Beijing, and to clarify the clinical necessity of adenovirus typing. Methods: In a cross-sectional study, 9 022 respiratory tract specimens collected from hospitalized children with acute respiratory infection from November 2017 to October 2019 in Affiliated Children's Hospital, Capital Institute of Pediatrics were screened for HAdV by direct immunofluorescence (DFA) and (or) nucleic acid detection. Then the Penton base, Hexon and Fiber gene of HAdV were amplified from HAdV positive specimens to confirm their HAdV types by phylogenetic tree construction. Clinical data such as laboratory results and imaging data were analyzed for children with predominate type HAdV infection using t, U, or χ² test. Results: There were 392 cases (4.34%) positive for HAdV among 9 022 specimens from hospitalized children with acute respiratory infection. Among those 205 cases who were successfully typed, 131 were male and 74 were female, age of 22.6 (6.7, 52.5) months,102 cases (49.76%) were positive for HAdV-3 and 86 cases (41.95%), HAdV-7, respectively, while 17 cases were confirmed as HAdV-1, 2, 4, 6, 14 or 21. In comparison of clinical characteristics between the predominate HAdV type 7 and 3 infection, significant differences were shown in proportions of children with wheezing (10 cases (11.63%) vs. 25 cases (24.51%)), white blood cell count >15 ×10⁹/L (4 cases (4.65%) vs.14 cases (13.73%)), white blood cell count <5×10⁹/L (26 cases (30.23%) vs.11 cases (10.78%)), procalcitonin level>0.5 mg/L (43 cases (50.00%) vs. 29 cases (28.43%)), multilobar infiltration (45 cases (52.33%) vs.38 cases (37.25%)), pleural effusion (23 cases (26.74%) vs. 10 cases (9.80%)), and severe adenovirus pneumonia (7 cases (8.14%) vs. 2 cases (1.96%)) with χ²=5.11, 4.44, 11.16, 9.19, 4.30, 9.25, 3.91 and P=0.024, 0.035, 0.001, 0.002, 0.038, 0.002, 0.048, respectively, and also in length of hospital stay (11 (8, 15) vs. 7 (5, 13) d, Z=3.73, P<0.001). Conclusions: HAdV-3 and 7 were the predominate types of HAdV infection in hospitalized children with acute respiratory tract infection in Beijing. Compared with HAdV-3 infection, HAdV-7 infection caused more obvious inflammatory reaction, more severe pulmonary symptoms, longer length of hospital stay, suggesting the clinical necessity of further typing of HAdVs.

The design of multi-stage open-loop hollow fiber membrane contactor and its application in ammonia capture from hydrolyzed human urine

Hollow fiber membrane contactor (HFMC) is a promising technology for removing or recovering wastewaters' volatile components. Developing a rational design method is very important for guiding its further application. In this study, we proposed a method to design the multi-stage open-loop hollow fiber membrane contactor (HFMC) employing shell-side influent. In addition, a three-stage HFMC was designed to capture ammonia from real hydrolyzed human urine. A continuous 1344 h performance was conducted. The results showed that the experimental effluent total ammonium nitrogen (TAN) concentration and ammonia mass transfer coefficient matched the predicted results well, which indicated that the design method was feasible and accurate. The three-stage HFMC showed excellent ammonia capture capacity with a TAN recovery efficiency of 93.29%, and the final effluent TAN concentration was 30.98±14.70 mg/L which met our design requirement (lower than 50 mg/L). More than 98.92% of the inorganic ions and 96.85% of the organic matter were retained in the effluent. The stripping solution after ammonia capture was the high-purity ammonium sulfate solution with low concentration of small molecular weight hydrophilic organic substances. The inorganic and organic membrane fouling was mild and randomly distributed. The inorganic membrane fouling was attributed to the deposition of calcium-, magnesium-, phosphate-related inorganic compounds, while the organic membrane fouling was mainly protein and carbohydrate. After the ammonia capture process, the surface hydrophobicity and pore properties of the membranes had no significant changes. These results demonstrated that the multi-stage open-loop HFMC could be a potential alternative for ammonia recovery from the high concentration of ammonium nitrogen wastewater.

[Clinical characteristics of children infected with different subtypes/genotypes of human respiratory syncytial virus in Beijing from 2009 to 2017]

Objective: To explore the different clinical characteristics of children infected with different subtype/genotype of human respiratory syncytial virus (HRSV) in Beijing. Methods: Respiratory specimens for positive HRSV were randomly collected from children with acute respiratory tract infection (ARTI) in the epidemic season of HRSV from November of each year to January of the next year during 2009 and 2017. G genes of HRSV were amplified and sequenced for subtyping and genotyping by bioinformatics analysis. Clinical data were collected and analyzed. Results: Out of 590 children, 376 (63.7%) with subtype A, and 214 (36.3) with subtype B. The annual dominant subtypes of HRSV from 2009 to 2017 were B-A-A-B-AB-A-A-B-A, respectively, whilst a total of 10 genotypes were detected with 95.8% assigned to genotype ON1 and NA1 of subtype A, and genotype BA9 of subtype B. Children infected with subtype B (96 cases, 44.9%) were more likely aged 0-3 month old than those with subtype A (118 cases, 31.4%) (P=0.001), and more likely to be admitted to Intensive Care Unit(ICU) ((124 cases, 57.9%) than those with subtype A (172 cases, 45.7%)) (P=0.005). Statistical significance were shown among children infected with genotype ON1, NA1 or BA9, in the possibility of infection in children aged 0-3 month (P=0.003), proportion of admission into ICU (P=0.007), length of stay in hospital (P=0.001), and clinical outcome (P=0.001), respectively. Conclusion: Children infected with different subtype or genotype of HRSV have different clinical characteristics, which stresses the important role of the monitoring HRSV subtypes and genotypes among children.

Rapid and accurate diagnosis of brain abscess caused by Nocardia asiatica with a combination of Ziehl-Neelsen staining and metagenomics next-generation sequencing

BACKGROUND AND PURPOSE

Early and accurate diagnosis is vital in cerebral nocardiosis, a very rare and infectious disease associated with a high mortality rate. Herein, we report a case that a patient with brain abscess was swiftly diagnosed and successfully treated.

METHODS

We report a case of a 61-year-old woman with a brain abscess caused by Nocardia asiatica, diagnosed by a combination of Ziehl-Neelsen staining and metagenomics next-generation sequencing (mNGS).

RESULTS

A 61-year-old woman with left breast cancer resection, diabetes mellitus and a 7-month discontinuous cough and fever was admitted to our hospital. On the third day of hospitalization, she experienced a sudden loss of consciousness and was diagnosed with a brain abscess and a pathological change in cerebral mass on brain magnetic resonance imaging (MRI). Due to the failure of culturing any microorganisms from the pup, the dissected sample from the patient with Ziehl-Neelsen staining tested positive for acid-fast bacilli and was subjected to mNGS. The pathogen was identified as N. asiatica and the patient was treated accordingly with linezolid and trimethoprim-sulfamethoxazole until complete recovery was confirmed by the follow-up cerebral MRI.

CONCLUSIONS

This is the first case report of a brain abscess caused by N. asiatica being swiftly diagnosed by a combination of Ziehl-Neelsen staining and mNGS. This rapid diagnosis allowed us to successfully treat this rare infection.

Circularly Polarized Laser with Chiral Nematic Cellulose Nanocrystal Cavity

Circularly polarized (CP) lasers derived from low-cost and renewable raw sources are attracting increasing attention in photonics and material science. Here, we present a facile and effective approach to fabricate CP lasers by the evaporation-induced assembly of cellulose nanocrystals (CNCs) and a laser dye. The obtained laser exhibits a controlled chiral nematic structure, which acts as a chiral optical cavity, and varied chiral coupling interactions. It is shown that the CNC-based laser can modify the polarization state of the laser into left-handed polarization, leading to strong CP laser emission (CPLE) with a dissymmetry factor up to 0.35. The chiral nematic CNC structure proves to be a versatile yet straightforward strategy to generate strong and tailored CPLE.

Ammonia capture from human urine to harvest liquid N-P compound fertilizer by a submerged hollow fiber membrane contactor: Performance and fertilizer analysis

In this study, we developed a submerged hollow fiber membrane contactor (HFMC) to recover ammonia from human urine to get compound N-P fertilizers. The ammonia capture performance, water vapor transmembrane performance, ion rejection performance and the liquid fertilizer components using 1-4 mol/L H₃PO₄ as the stripping solution was comprehensively investigated. Increasing H₃PO₄ concentration did not significantly affect the ammonia capture performance but the water vapor transfer and fertilizer components. The ammonia mass transfer coefficients were in a range of 1.95×10^-6±4.77×10^-8 to 2.28×10^-6±6.71×10^-8 m/s and the ammonia flux fluctuated between 17.80 and 20.80 g/m²·h. The water vapor flux increased with the increase of stripping solution concentration and the time elapsed. The N content (21.29-55.24 g/L) was in the range of the commercial products while the P₂O₅ content (99.41-281 g/L) was slightly higher, which can be used in the soils or plants with a high demand for phosphorus. The liquid fertilizers were all mixtures of (NH₄)₂HPO₄ and NH₄H₂PO_4, but the distribution ratio slightly changed with the different initial H₃PO₄ concentration. The economic assessment showed that harvesting liquid N-P fertilizer from human urine using HFMC can make a profit of $7.089/L.

A Position Weighted Information Based Word Embedding Model for Machine Translation

Deep learning technology promotes the development of neural network machine translation (NMT). End-to-End (E2E) has become the mainstream in NMT. It uses word vectors as the initial value of the input layer. The effect of word vector model directly affects the accuracy of E2E-NMT. Researchers have proposed many approaches to learn word representations and have achieved significant results. However, the drawbacks of these methods still limit the performance of E2E-NMT systems. This paper focuses on the word embedding technology and proposes the PW-CBOW word vector model which can present better semantic information. We apply these word vector models on IWSLT14 German-English, WMT14 English-German, WMT14 English-French corporas. The results evaluate the performance of the PW-CBOW model. In the latest E2E-NMT systems, the PW-CBOW word vector model can improve the performance.

Language Model Pre-training Method in Machine Translation Based on Named Entity Recognition

Neural Machine Translation (NMT) model has become the mainstream technology in machine translation. The supervised neural machine translation model trains with abundant of sentence-level parallel corpora. But for low-resources language or dialect with no such corpus available, it is difficult to achieve good performance. Researchers began to focus on unsupervised neural machine translation (UNMT) that monolingual corpus as training data. UNMT need to construct the language model (LM) which learns semantic information from the monolingual corpus. This paper focuses on the pre-training of LM in unsupervised machine translation and proposes a pre-training method, NER-MLM (named entity recognition masked language model). Through performing NER, the proposed method can obtain better semantic information and language model parameters with better training results. In the unsupervised machine translation task, the BLEU scores on the WMT’16 English–French, English–German, data sets are 35.30, 27.30 respectively. To the best of our knowledge, this is the highest results in the field of UNMT reported so far.

The regulatory effects of phytosterol esters (PSEs) on gut flora and faecal metabolites in rats with NAFLD

Recent studies have shown that the occurrence and progression of nonalcoholic fatty liver disease (NAFLD) can be aggravated by dysregulation of intestinal flora. We previously found that phytosterol esters (PSEs) could effectively prevent the progression of NAFLD. Here, we further investigated the regulatory effect that PSEs have on gut flora and faecal metabolites in rats with NAFLD. Adult SD (Sprague Dawley) rats were randomized into four groups: the normal chow diet (NC), high-fat diet (HFD), low-dose PSE (0.05 g per 100 g BW, PSEL) and high-dose PSE (0.10 g per 100 g BW, PSEH) groups. PSEs were intragastrically administered once a day for 12 consecutive weeks. Our work indicated that high-dose PSE treatment effectively inhibited the increase in liver and abdominal fat indexes (P < 0.01) and hepatic lipids (P < 0.01); a high dose PSE treatment effectively corrected the HFD-induced intestinal flora imbalance by changing the diversity. The relative abundances of the four phyla (Firmicutes, Proteobacteria, Actinobacteria and Verrucomicrobia) and partial bacteria at the genus level (Faecalibacterium, Akkermansia, etc.) in the PSEH group were closer to those in the NC group. High-dose PSE intervention significantly increased the relative abundance of Bacteroidetes and Anaerostipes. Compared with the HFD, PSEH treatment significantly decreased the ionic strengths of bile acid metabolism products (P < 0.05), which were positively correlated with hepatic steatosis. In conclusion, PSE treatment exerts a beneficial effect on NAFLD that is associated with its regulatory action on intestinal flora and faecal metabolites, which might present a new opportunity to develop effective and safe preventive strategies against NAFLD.

Focal TLR4 activation mediates disturbed flow-induced endothelial inflammation

AIMS

Disturbed blood flow at arterial branches and curvatures modulates endothelial function and predisposes the region to endothelial inflammation and subsequent development of atherosclerotic lesions. Activation of the endothelial Toll-like receptors (TLRs), in particular TLR4, contributes to vascular inflammation. Therefore, we investigate whether TLR4 can sense disturbed flow (DF) to mediate the subsequent endothelial inflammation.

METHODS AND RESULTS

En face staining of endothelium revealed that TLR4 expression, activation, and its downstream inflammatory markers were elevated in mouse aortic arch compared with thoracic aorta, which were absent in Tlr4mut mice. Similar results were observed in the partial carotid ligation model where TLR4 signalling was activated in response to ligation-induced flow disturbance in mouse carotid arteries, and such effect was attenuated in Tlr4mut mice. DF in vitro increased TLR4 expression and activation in human endothelial cells (ECs) and promoted monocyte-EC adhesion, which were inhibited in TLR4-knockdown ECs. Among endogenous TLR4 ligands examined as candidate mediators of DF-induced TLR4 activation, fibronectin containing the extra domain A (FN-EDA) expressed by ECs was increased by DF and was revealed to directly interact with and activate TLR4.

CONCLUSION

Our findings demonstrate the indispensable role of TLR4 in DF-induced endothelial inflammation and pinpoint FN-EDA as the endogenous TLR4 activator in this scenario. This novel mechanism of vascular inflammation under DF condition may serve as a critical initiating step in atherogenesis.

Electro-responsive Liquid Crystalline Nanocelluloses with Reversible Switching

Liquid crystalline cellulose nanocrystals (CNCs) which can change their structural and optical properties in an electric field could be a new choice for advanced optoelectronic devices. Unfortunately, the exploration of its performance in an electric field is underdeveloped. Hence, we reveal some interesting dielectric coupling activities of liquid crystalline CNC in an electric field. The CNC tactoid is shown to orient its helix axis normal to the electric field direction. Then, as a function of the electric field strength and frequency, the tactoid can be stretched along with a pitch increase, with a deformation mechanism significantly differing at varied frequencies, and finally untwists the helix axis to form a nematic structure upon increasing the electric field strength. Moreover, a straightforward method to visualize the electric field is demonstrated, by combining the CNC uniform lying helix textures with polarized optical microscopy. We envision these understandings could facilitate the development of liquid crystalline CNC in the design of electro-optical devices.

The Structural, Electronic, and Optical Properties of Ge/Si Quantum Wells: Lasing at a Wavelength of 1550 nm

The realization of a fully integrated group IV electrically driven laser at room temperature is an essential issue to be solved. We introduced a novel group IV side-emitting laser at a wavelength of 1550 nm based on a 3-layer Ge/Si quantum well (QW). By designing this scheme, we showed that the structural, electronic, and optical properties are excited for lasing at 1550 nm. The preliminary results show that the device can produce a good light spot shape convenient for direct coupling with the waveguide and single-mode light emission. The laser luminous power can reach up to 2.32 mW at a wavelength of 1550 nm with a 300-mA current. Moreover, at room temperature (300 K), the laser can maintain maximum light power and an ideal wavelength (1550 nm). Thus, this study provides a novel approach to reliable, efficient electrically pumped silicon-based lasers.

Structural Arrest and Phase Transition in Glassy Nanocellulose Colloids

From drying blood to oil paint, the developing of a glassy phase from colloids is observed on a daily basis. Colloidal glass is solid soft matter that consists of two intertwined phases: a random packed particle network and a fluid solvent. By dispersing charged rod-like cellulose nanoparticles into a water-ethylene glycol cosolvent, here we demonstrate a new kind of colloidal glass with a high liquid crystalline order, namely, two general superstructures with nematic and cholesteric packing states are preserved and jammed inside the glass matrix. During the glass formation process, structural arrest and phase transition occur simultaneously at high particle concentrations, yielding solid-like behavior as well as a frozen liquid crystal texture that is because of caging of the charged colloids through neighboring long-ranged repulsive interactions.

When nanocellulose meets diffraction grating: freestanding photonic paper with programmable optical coupling

Photonic crystals based on plasmonic or dielectric periodic structures have attracted considerable interest owing to their capabilities to control light-matter interactions with tailored precision. By using a nanocellulose derived chiral liquid crystal as a building block, here we demonstrate a bio-inspired dual photonic structure that contains the combination of microscopic periodic 1D surface grating and nanoscopic helical organization, giving rise to programmable colour mixing and polarization rotation. We show that a variation in the photonic band-gap in the bulk matrix leads to simultaneous control over the reflection and diffraction of light with controllable iridescence.

Absence of Evidence of Electrical Switching of the Antiferromagnetic Néel Vector

Much theoretical and experimental attention has been focused on the electrical switching of the antiferromagnetic (AFM) Néel vector via spin-orbit torque. Measurements employing multiterminal patterned structures of Pt/AFM show recurring signals of the supposedly planar Hall effect and magnetoresistance, implying AFM switching. We show in this Letter that similar signals have been observed in structures with and without the AFM layer, and of an even larger magnitude using different metals and substrates. These may not be the conclusive evidence of spin-orbit torque switching of AFM, but the thermal artifacts of patterned metal structure on substrate. Large current densities in the metallic devices, beyond the Ohmic regime, can generate unintended anisotropic thermal gradients and voltages. AFM switching requires unequivocal detection of the AFM Néel vector before and after SOT switching.

MiR-378 promotes the cell proliferation of non-small cell lung cancer by inhibiting FOXG1

OBJECTIVE

To identify the functioning mode of miR-378 on non-small cell lung cancer (NSCLC) and provide therapeutic targets for NSCLC.

PATIENTS AND METHODS

Expression levels of miR-378 in human NSCLC tissue samples and NSCLC-derived cell lines were measured by using quantitative Real-time polymerase chain reaction (PCR). Cell proliferation capacity was assessed by methyl thiazolyl tetrazolium (MTT) assay and colony formation assay. Cell apoptosis and cell cycle distribution were identified by flow cytometry. Downstream target gene was confirmed by using luciferase and Western blotting assays.

RESULTS

MiR-378 was significantly elevated in NSCLC tissues when compared with para-carcinoma tissues (n=42). Decreased-miR-378 could attenuate cell proliferation capacity, as well as promoted cell apoptosis and induced cell cycle arrest at G0/G1 phase. FOXG1 was chosen as the target gene of miR-378 by bioinformatics analysis and luciferase reporter assay. Moreover, restoration of miR-378 could impair the tumor suppression role of downregulated-miR-378 on NSCLC growth.

CONCLUSIONS

Decreased-miR-378 exerted tumor-suppressive effects on NSCLC growth via targeting FOXG1 in vitro, which provided an innovative and candidate target for diagnosis and treatment of NSCLC.

Modulating the Structural Orientation of Nanocellulose Composites through Mechano-Stimuli

It is of great interest to dynamically manipulate the optical property by controlling nanostructures under external stimuli. In this work, chiral photonic cellulose nanocrystal (CNC) and elastic polyurethane (PU) composite films demonstrate reversible optical tunability arising from structural transition between the chiral nematic and layered pseudonematic order. The composite films exhibit impressive water resistance and mechanical adaptability. Reversible modulation of the optical property of the composite CNC/PU film is enabled during mechanical stretching and water absorption. Film stretching is accompanied by CNC transition from a chiral nematic to layered pseudonematic structure. After fixation, shape recovery takes place when exposed to water, and the CNC structure reverts to the initial chiral nematic order. These reversibly switchable shape and optical properties further advance the study and design of smart optical and mechanical sensors.

White Emissive Carbon Dots Actuated by the H-/J-Aggregates and Förster Resonance Energy Transfer

Carbon dots (CDs) have been demonstrated to be fluorescent materials for the new phosphor-free white light-emitting diodes (WLEDs). Herein, we synthesized a novel white CDs (WCDs). The spectrum highly matches the solar light spectrum (AM 1.5), which is a potentially high-color-quality lighting source material. The CDs contain blue, green, and red emissive centers produced from catechol, o-phenylenediamine, and their complexes, respectively. In addition, the photoluminescence mechanism had been revealed; three emission centers could be excited by a single UV source actuated by the formation of H- and J-aggregates and FRET between the CDs. Then the phosphor-free WLEDs were fabricated with a UV chip encapsulated with silicon resin containing the as-obtained CDs, which exhibit CIE coordinates of (0.33,0.33), a color rendering index (CRI) of 93, and a correlated color temperature (CCT) of 5453 K. The WLEDs show super stability and a high solar spectrum matching degree of 85-114%, protecting the eyesight. This provides a new way to design healthy lighting materials.

Enhanced photocatalytic N2 fixation by promoting N2 adsorption with a co-catalyst

Photocatalytic N₂ fixation involves a nitrogen reduction reaction on the surface of the photocatalyst to convert N₂ into ammonia. Currently, the adsorption of N₂ is the limiting step for the N₂ reduction reaction on the surface of the catalyst. Based on the concept of photocatalytic water splitting, the photocatalytic efficiency can be greatly enhanced by introducing a co-catalyst. In this report, we proposed a new strategy, namely, the loading of a NiS co-catalyst on CdS nanorods for photocatalytic N₂ fixation. Theoretical calculation results indicated that N₂ was effectively adsorbed onto the NiS/CdS surface. Temperature programmed desorption studies confirmed that the N₂ molecules preferred to adsorb onto the NiS/CdS surface. Linear sweep voltammetry results revealed that the overpotential of the N₂ reduction reaction was reduced by loading NiS. Furthermore, transient photocurrent and electrochemical impedance spectroscopy indicated that the charge separation was enhanced by introducing NiS. Photocatalytic N₂ fixation was carried out in the presence of the catalyst dispersed in water without any sacrificial agent. As a result, 1.0 wt% NiS/CdS achieved an ammonia production rate of 2.8 and 1.7 mg L^-1 for the first hour under full spectrum and visible light (λ > 420 nm), respectively. The catalyst demonstrated apparent quantum efficiencies of 0.76%, 0.39% and 0.09% at 420, 475 and 520 nm, respectively. This study provides a new method to promote the photocatalytic efficiency of N₂ fixation.

Effective treatment of reverse osmosis concentrate from incineration leachate using direct contact membrane distillation coupled with a NaOH/PAM pre-treatment process

Reverse osmosis is frequently used to process biologically treated leachate from municipal solid waste incineration plants. Reverse osmosis concentrate from incineration leachate (ROCIL) contains extremely high concentrations of monovalent and divalent ions (e.g. Na⁺, K⁺, Mg²⁺, and Ca²⁺) and some refractory organic pollutants (e.g. humic substances). In this study, lab-scale direct contact membrane distillation (DCMD) coupled with pre-treatment was applied to treat ROCIL. NaOH and polyacrylamide (PAM) chemical precipitation and coagulation pretreatment effectively removed Ca²⁺ and Mg²⁺ (>99%) from the ROCIL, which also significantly improved the treatment efficiency of DCMD and slowed down membrane fouling caused by Mg₅(CO₃)₄(OH)₂·4H₂O and CaCO₃ scaling on the membrane surface. During the long-term operation of DCMD, ROCIL was concentrated 21 times and nearly all of the inorganic ions (>99.9%) and organic matter (>99%) were removed from the pre-treated ROCIL. A strong interaction occurred due to the accumulation of humic substances and metal ions in the feed solution, which lead to inorganic and organic scaling deposited on the membrane surface and pores, but the wetting phenomenon was not serious. These results demonstrated that DCMD coupled with NaOH/PAM pre-treatment can be a potential alternative for further treatment and concentration of ROCIL to obtain high quality water.

Endothelial TFEB (Transcription Factor EB) Restrains IKK (IκB Kinase)-p65 Pathway to Attenuate Vascular Inflammation in Diabetic db/db Mice

Objective—

TFEB (transcription factor EB) was recently reported to be induced by atheroprotective laminar flow and play an anti-atherosclerotic role by inhibiting inflammation in endothelial cells (ECs). This study aims to investigate whether TFEB regulates endothelial inflammation in diabetic db/db mice and the molecular mechanisms involved.

Approach and Results—

Endothelial denudation shows that TFEB is mainly expressed in ECs in mouse aortas. Western blotting shows TFEB total protein level decreases whereas the p-TFEB S142 (phosphorylated form of TFEB) increases in db/db mouse aortas, suggesting a decreased TFEB activity. Adenoviral TFEB overexpression reduces endothelial inflammation as evidenced by decreased expression of vascular inflammatory markers in db/db mouse aortas, and reduced expression of a wide range of adhesion molecules and chemokines in human umbilical vein ECs. Monocyte attachment assay shows TFEB suppresses monocyte adhesion to human umbilical vein ECs. RNA sequencing of TFEB-overexpressed human umbilical vein ECs suggested TFEB inhibits NF-κB (nuclear factor-kappa B) signaling. Indeed, luciferase assay shows TFEB suppresses NF-κB transcriptional activity. Mechanistically, TFEB suppresses IKK (IκB kinase) activity to protect IκB-α from degradation, leading to reduced p65 nuclear translocation. Inhibition of IKK by PS-1145 abolished TFEB silencing-induced inflammation in human umbilical vein ECs. Lastly, we identified KLF2 (Krüppel-like factor 2) upregulates TFEB expression and promoter activity. Laminar flow experiment showed that KLF2 is required for TFEB induction by laminar flow and TFEB is an anti-inflammatory effector downstream of laminar flow-KLF2 signaling in ECs.

Conclusions—

These findings suggest that TFEB exerts anti-inflammatory effects in diabetic mice and such function in ECs is achieved by inhibiting IKK activity and increasing IκBα level to suppress NF-κB activity. KLF2 mediates TFEB upregulation in response to laminar flow.

Bacterial Cellulose: A Versatile Chiral Host for Circularly Polarized Luminescence

Materials capable of circularly polarized luminescence (CPL) have attracted considerable attention for their promising potential applications. Bacterial cellulose (BC) was characterized as having a stable right-handed twist, which makes it a potential chiral host to endow luminophores with CPL. Then, the CPL-active BC composite film was constructed by simply impregnating bacterial cellulose pellicles with dilute aqueous solutions of luminophores (rhodamine B, carbon dots, polymer dots) and drying under ambient conditions. Simple encapsulation of luminophores renders BC with circularly polarized luminescence with a dissymmetry factor of up to 0.03. The multiple chiral centers of bacterial cellulose provide a primary asymmetric environment that can be further modulated by supramolecular chemistry, which is responsible for its circular polarization ability. We further demonstrate that commercial grade paper may endow luminophores with CPL activity, which reifies the universality of the method.

Competitive interaction on dual-species biofilm formation by spoilage bacteria, Shewanella baltica and Pseudomonas fluorescens

AIMS

This study aims to characterize the biofilm produced by mono- and dual-species of Shewanella baltica and Pseudomonas fluorescens as fish spoilers at the different incubation temperature, and to elucidate the interactive behaviour of dual-species biofilm development.

METHODS AND RESULTS

The mono- and dual-species biofilm formation and adhesion characteristics of S. baltica and P. fluorescens were evaluated by using crystal violet staining, scanning electron microscopy and confocal laser scanning microscopy. Results showed that P. fluorescens had significantly higher biofilm biomass and polysaccharides production than S. baltica, and two isolates reached the maximum biofilm biomass during the early stationary phase. Lower biomass and polysaccharides in dual-species biofilms were observed compared to mono-species of P. fluorescens. Meanwhile, S. baltica and P. fluorescens formed fragile and viscous pellicles with different spatial architectures respectively. In dual-species pellicle few large microcolonies were dominated by P. fluorescens. Compared to mono-species of PF07, adherent cell population and biofilm thickness at the developing phase significantly decreased, and biofilm-forming cycle prolonged in the dual-species biofilms. Biofilm formation and adhesion of mono- and dual-species at 4 or 15°C were significantly higher than at 30°C during the same phase. The culture supernatant extracts of the two spoilage strains greatly inhibited biofilm development to each other.

CONCLUSIONS

Shewanella baltica and P. fluorescens had different biofilm and pellicle characteristics, and the inhibitory development on dual-species biofilm was associated with the competitive interaction by the two psychrotrophic spoilage bacteria.

SIGNIFICANCE AND IMPACT OF THE STUDY

This work contributes to a better understanding of interactive behaviour of multispecies biofilm communities by psychrotrophic spoilage bacteria at low temperature, which could contribute to further control contamination of spoilage organism during the preservation and processing of aquatic products.

Chiral nematic mesoporous silica films enabling multi-colour and on–off switchable circularly polarized luminescence

Chiral nematic mesoporous silica films encapsulating luminophores enabled R-CPL and multi-colour CPL with g_lum values of up to −0.38.

Enhancing bacterial transport with saponins in saturated porous media for the bioaugmentation of groundwater: visual investigation and surface interactions

The success of bioaugmentation processes for the remediation of groundwater contamination relies on effective transport of the injected microorganisms in a subsurface environment. Biosurfactants potentially affect bacterial attachment and transport behavior in porous media. Although saponins as biosurfactants are abundant in nature, their influence on bacterial transport in groundwater systems remains unknown. In this research, tank visual-transport experiments, breakthrough curve monitoring, and surface property measurement were performed to evaluate the effects of saponins on the transport of Pseudomonas migulae AN-1 cells, which were used as a model bacterium in saturated sand. Results show that the 0.1% saponins could effectively facilitated the AN-1 secondary transport and the addition of saponins decreased the hydrophobicity of AN-1 and sand. The role of the promotion of saponins was more dominant than that of the inhibition of ions on AN-1 transport in a saturated porous medium when ions and saponins coexisted. The interactions between AN-1 and sand grains with saponins and ions were explained in accordance with the Derjaguin-Landau-Verwey-Overbeek theory.

Enhancing photocatalytic performance by constructing ultrafine TiO2 nanorods/g-C3N4 nanosheets heterojunction for water treatment

Photocatalysis is considered to be a clean, green and efficient method to purify water. In this report, we first developed a highly efficient ultrafine TiO₂ nanorods/g-C₃N₄ nanosheets (TiO₂ NR/CN NS) composites via a simple hydrothermal method. Tiny TiO₂ nanorods (diameter: ∼1.5 nm and length: ∼8.3 nm) were first loaded in situ on the CN NS by adding graphitic carbon nitride (g-C₃N₄) to the reaction solution. The TiO₂ NR/CN NS composites present high charge separation efficiency and broader light absorbance than P25 TiO₂. Furthermore, we illustrate that the TiO₂ NR/CN NS catalyst possesses high performance for the photocatalytic degradation of the common and stubborn pollutants in water, such as the rhodamine B (RhB) dye and phenol. Under visible light (λ > 420 nm) irradiation, the apparent rate of the TiO₂ NR/CN NR is 172 and 41 times higher than that of the P25 TiO₂ and TiO₂ NR, respectively. Additionally, we speculated that the heterojunction formed between TiO₂ NR and CN NS, which is the basis for the experiments we have designed and the corresponding results. We demonstrated that reactive oxidative species such as superoxide anion radical and holes play critical roles in the degradation, and the hydroxyl radical contributes nothing to the degradation.