Enhancement of triclocarban biodegradation: Metabolic division of labor in co-culture of Rhodococcus sp. BX2 and Pseudomonas sp. LY-1.

Triclocarban (TCC) and its metabolite, 3,4-dichloroaniline (DCA), are classified as emerging organic contaminants (EOCs). Significant concerns arise from water and soil contamination with TCC and its metabolites. These concerns are especially pronounced at high concentrations of up to approximately 20 mg/kg dry weight, as observed in wastewater treatment plants (WWTPs). Here, a TCC-degrading co-culture system comprising Rhodococcus rhodochrous BX2 and Pseudomonas sp. LY-1 was utilized to degrade TCC (14.5 mg/L) by 85.9% in 7 days, showing improved degradation efficiency compared with monocultures. A combination of high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), genome sequencing, transcriptomic analysis, and quantitative reverse transcription-PCR (qRT-PCR) was performed. Meanwhile, through the combination of further experiments involving heterologous expression and gene knockout, we proposed three TCC metabolic pathways and identified four key genes (tccG, tccS, phB, phL) involved in the TCC degradation process. Moreover, we revealed the internal labor division patterns and connections in the co-culture system, indicating that TCC hydrolysis products were exchanged between co-cultured strains. Additionally, mutualistic cooperation between BX2 and LY-1 enhances TCC degradation efficiency. Finally, phytotoxicity assays confirmed a significant reduction in the plant toxicity of TCC following synergistic degradation by two strains. The in-depth understanding of the TCC biotransformation mechanisms and microbial interactions provides useful information for elucidating the mechanism of the collaborative biodegradation of various contaminants.

Synthesis of the Ag2S/PANI@PES Composite Membrane and Its Antipollution Properties.

Membrane separation technology offers a sustainable and efficient solution to wastewater management; however, membrane fouling significantly impedes its application. Photocatalytic membranes, integrating photocatalytic and membrane separation technologies, enhance membrane separation efficacy while effectively mitigating organic and biological contaminations. In this work, Ag2S/PANI@PES composite membranes were prepared via a facile in situ polymerization and successive layer adsorption technique. The modified poly(ether sulfone) (PES) membrane demonstrated improved hydrophilicity and separation performance, and its heterostructure between polyaniline (PANI), Ag0, and Ag2S effectively addressed organic fouling issues. Moreover, Ag2S/PANI@PES exhibited outstanding antimicrobial properties, as well as chemical and mechanical stability.

Profiles of visual perceptual learning in feature space.

Visual perceptual learning (VPL), experience-induced gains in discriminating visual features, has been studied extensively and intensively for many years, its profile in feature space, however, remains unclear. Here, human subjects were trained to perform either a simple low-level feature (grating orientation) or a complex high-level object (face view) discrimination task over a long-time course. During, immediately after, and one month after training, all results showed that in feature space VPL in grating orientation discrimination was a center-surround profile; VPL in face view discrimination, however, was a monotonic gradient profile. Importantly, these two profiles can be emerged by a deep convolutional neural network with a modified AlexNet consisted of 7 and 12 layers, respectively. Altogether, our study reveals for the first time a feature hierarchy-dependent profile of VPL in feature space, placing a necessary constraint on our understanding of the neural computation of VPL.

Exploring the potential of a new marine bacterium associated with plastisphere to metabolize dibutyl phthalate and bis(2-ethylhexyl) phthalate by enrichment cultures combined with multi-omics analysis.

Phthalic acid esters (PAEs) plasticizers are virulent endocrine disruptors that are mixed into plastics while fabricating and can filter out once they release into the surrounding environments. Plastic surfaces serve as new habitats for microorganisms, referred to as 'plastisphere'. Previous metagenomic investigations of the 'plastisphere' indicated that marine plastic surfaces may harbor microbes that degrade PAEs plasticizers. To our knowledge, the potential of microorganisms in the marine 'plastisphere' to metabolize PAEs is poorly understood. In this study, by screening the natural microbial community on plastic debris that had been deployed in situ for up to 20 months, a novel marine bacterium, Microbacterium esteraromaticum DEHP-1, was successfully isolated, which could degrade and mineralize 10-200 mg/L dibutyl phthalate (DBP) and bis(2-ethylhexyl) phthalate (DEHP). According to the results of gas chromatography-mass spectrometry (GC-MS) and whole genome mining of strain DEHP-1, we found that strain DEHP-1 may metabolize DBP by successive removal of the ester side chain by esterase 2518 to produce mono-butyl phthalate (MBP) and phthalic acid (PA), whereas the degradation of DEHP may take place by the direct action of monooxygenase 0132 on the fatty acid side chain of the DEHP molecule to produce di-n-hexyl phthalate (DnHP) and DBP, and then the subsequent hydrolysis of DBP by de-esterification to PA and finally into the tricarboxylic acid (TCA) cycle. Non-targeted metabolomics results showed that intracellular degradation of PAEs did not happen. However, exposure to PAEs was found to significantly affect pathways such as arginine and proline, riboflavin, glutathione and lysine degradation. Therefore, the intracellular metabolic behavior of strain DEHP-1 exposed to PAEs was proposed for the first time. This study sheds light on the metabolic capacity and strategies of bacteria in the marine 'plastisphere' to effectively degrade PAEs and highlights the importance of marine microbes in mitigating plastic poisonousness.

A source for category-induced global effects of feature-based attention in human prefrontal cortex.

Global effects of feature-based attention (FBA) are generally limited to stimuli sharing the same or similar features, as hypothesized in the "feature-similarity gain model." Visual perception, however, often reflects categories acquired via experience/learning; whether the global-FBA effect can be induced by the categorized features remains unclear. Here, human subjects were trained to classify motion directions into two discrete categories and perform a classical motion-based attention task. We found a category-induced global-FBA effect in both the middle temporal area (MT+) and frontoparietal areas, where attention to a motion direction globally spread to unattended motion directions within the same category, but not to those in a different category. Effective connectivity analysis showed that the category-induced global-FBA effect in MT+ was derived by feedback from the inferior frontal junction (IFJ). Altogether, our study reveals a category-induced global-FBA effect and identifies a source for this effect in human prefrontal cortex, implying that FBA is of greater ecological significance than previously thought.

Biofilms retard the desorption of benzo(a)pyrene from polyethylene pellets in the marine environment.

Microplastics are emerging as vectors for the transport hydrophobic organic compounds (HOCs) in aquatic environments, however, their impact is poorly understood due to the lack of field studies. In this study, the pristine and benzo(a)pyrene (B[a]P) adsorbed polyethylene (PE) pellets were placed at Haihe Estuary (Tianjin, China) for 80 days to investigate desorption behavior. Combining laboratory and in situ experiments, this study firstly verified that the intra-particle diffusion was the rate-limiting step for the desorption process of B[a]P from PE microplastics under different environmental conditions. By hindering the desorption and modifying MPs surface, biofilm might play a key role in desorption process, leading to the apparent hysteresis of the field desorption process at our time scale. Potential degradation of the polymer and B[a]P by biofilms, however, would support continuing desorption. The study explored the interaction of biofilm and MPs-contaminants mixture and its implications for the environmental fate of HOCs.

A novel marine bacterium Exiguobacterium marinum a-1 isolated from in situ plastisphere for degradation of additive-free polypropylene.

As the ecological niche most closely associated with polymers, microorganisms in the 'plastisphere' have great potential for plastics degradation. Microorganisms isolated from the 'plastisphere' could colonize and degrade commercial plastics containing different additives, but the observed weight loss and surface changes were most likely caused by releasing the additives rather than actual degradation of the plastics itself. Unlike commercial plastics that contain additives, whether marine microorganisms in the 'plastisphere' have adapted to additive-free plastics as a surface to colonize and potentially degrade is not yet known. Herein, a novel marine bacterium, Exiguobacterium marinum a-1, was successfully isolated from mature 'plastisphere' that had been deployed in situ for up to 20 months. Strain a-1 could use additive-free polypropylene (PP) films as its primary energy and carbon source. After strain a-1 was incubated with additive-free PP films for 80 days, the weight of films decreased by 9.2%. The ability of strain a-1 to rapidly form biofilms and effectively colonize the surface of additive-free PP films was confirmed by Scanning Electron Microscopy (SEM), as reflected by the increase in roughness and visible craters on the surface of additive-free PP films. Additionally, the functional groups of -CO, -C-H, and -OH were identified on the treated additive-free PP films according to Fourier Transform Infrared (FTIR). Genomic data from strain a-1 revealed a suite of key genes involved in biosurfactant synthesis, flagellar assembly, and cellular chemotaxis, contributing to its rapid biofilm formation on hydrophobic polymer surfaces. In particular, key enzymes that may be responsible for the degradation of additive-free PP films, such as glutathione peroxidase, cytochrome p450 and esterase were also recognized. This study highlights the potential of microorganisms present in the 'plastisphere' to metabolize plastic polymers and points to the intrinsic importance of the new strain a-1 in the mitigation of plastic pollution.

An amidase and a novel phenol hydroxylase catalyze the degradation of the antibacterial agent triclocarban by Rhodococcus rhodochrous.

Triclocarban (TCC) is an emerging and intractable environmental contaminant due to its hydrophobicity and chemical stability. However, the antibacterial property of TCC limits its biodegradation, and only the functional enzyme TccA involved in TCC degradation has been characterized to date. In this study, we report a highly efficient TCC-degrading bacterium, Rhodococcus rhodochrous BX2, that could degrade and mineralize TCC (10 mg/L) by 76.8% and 56.5%, respectively, within 5 days. Subsequently, the TCC biodegradation pathway was predicted based on the detection of metabolites using modern mass spectrometry techniques. Furthermore, an amidase (TccS) and a novel phenol hydroxylase (PHIND) encoded by the tccS and PHIND genes, respectively, were identified by genomic and transcriptomic analyses of strain BX2, and these enzymes were further unequivocally proven to be the key enzymes responsible for the metabolism of TCC and its intermediate 4-chloroaniline (4-CA) by using a combination of heterologous expression and gene knockout. Our results shed new light on the mechanism of TCC biodegradation and better utilization of microbes to remediate TCC contamination.

The toxicity of cooking oil fumes on human bronchial epithelial cells through ROS-mediated MAPK, NF-κB signaling pathways and NLRP3 inflammasome.

Cooking oil fumes (COFs) are the main pollutants in kitchen and indoor air, which threaten human health. Exposure to COFs may lead to respiratory diseases and impair pulmonary function. To investigate the toxicity of COFs on human bronchial epithelial cells (Beas-2B) and explore the underlying mechanisms, MTT assay was conducted to detect the viability of Beas-2B. Intracellular reactive oxygen species (ROS) levels and nitric oxide (NO) levels were determined with DCFH-DA assay and DAF-FM assay. The expression of genes involved in inflammation were measured with quantitative real-time PCR (qRT-PCR). The phosphorylation and the expression of proteins related to Mitogen-activated protein kinase (MAPK), NF-κB signaling pathways were measured with western blot. Our results revealed that COFs decreased cell viability, increased the ROS levels and NO levels and induced apoptosis in Beas-2B cells. The results of qRT-PCR and western blot showed that the expression of NLRP3, p65, iNOS, IL-1ß, and the factors related to oxidative stress and inflammation increased, NF-κB signaling pathway and MAPK signaling pathway were activated. This study provided some useful information to evaluate the toxicity of COFs and revealed the possible mechanism for the damage on respiratory system induced by COFs.

Space optical communication system with a sub-second acquisition time.

Acquisition is the key technology in space laser communication and the nodus in communication-link establishment. Traditional laser communication demands too long an acquisition time to meet the requirements of a space optical communication network and real-time transmission of big data. One novel laser communication system which fuses a laser communication function with a star-sensitive function to achieve precise autonomous calibration of the open-loop pointing direction of line of sight (LOS) is proposed and developed. Theoretical analysis and field experiments proved that the novel, to the best of our knowledge, laser-communication system can achieve sub-second-level scanless acquisition.

A Series of Pentanary Salt-Inclusion Chalcogenoborates Containing a B12Q12 (Q = S, Se) Cluster Exhibiting a Kleinman-Forbidden Frequency-Doubling Effect.

A series of pentanary chalcogenoborates (A3X)[InB12(InQ4)3] (A = K, Rb, Cs; X = Cl, Br, I; Q = S, Se) were obtained by high-temperature solid-state reactions. These salt-inclusion chalcogenides crystallize in the hexagonal space group P6322, a type of Kleinman-forbidden noncentrosymmetric structure. Their structures feature a [InB12(InQ4)3] open framework built by InQ6 octahedra and InQ4 tetrahedra consolidated B12 cluster, which accomodates octahedral cavities for XA6 units. They are second-harmonic generation active, and their optical properties were studied experimentally and theoretically. This work can evoke more interest in chalcogenoborate-based second-order nonlinear optical materials.

Resveratrol protects human bronchial epithelial cells against nickel-induced toxicity via suppressing p38 MAPK, NF-κB signaling, and NLRP3 inflammasome activation.

Nickel is a common environmental pollutant that can impair the lung, but the underlying mechanisms have not yet been fully elucidated. Furthermore, natural products are generally used to inhibit cell damage induced by heavy metal. Resveratrol possesses wide biological activities, including anti-inflammation and antioxidative stress. This study was conducted to explore the toxicity of nickel on human bronchial epithelial (BEAS-2B) cells and evaluate the protective effect of resveratrol. The results showed that nickel could induce cell apoptosis, increase oxidative stress, and promote the expression of pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-1ß, IL-6, IL-8, C-reaction protein. Western blot analysis showed that nickel activated p38 mitogen-activated protein kinase (MAPK), nuclear factor-kappa B, and nucleotide-binding oligomerization domain-like receptor pyrin-domain-containing protein 3 pathways, while resveratrol could reverse these effects. Our results suggested that resveratrol could protect BEAS-2B cells from nickel-induced cytotoxicity. Therefore, resveratrol is a potential chemopreventive agent against nickel-induced lung disease.

Partial Congener Substitution Induced Centrosymmetric to Noncentrosymmetric Transformation Witnessed by K3Ga3(Ge7-xMx)Se20 (M = Si, Sn) and Their Nonlinear Optical Properties.

Crystallizing in a noncentrosymmetric (NCS) structure is the essential requirement for a crystal to be second-order nonlinear optical (NLO) active. Here, a simple strategy of partial congener substitution is introduced to induce transformation of the known centrosymmetric K3Ga3Ge7Se20 (P21/c) to the new isostructural NCS species K3Ga3(Ge6.17Sn0.83)Se20 (1) and K3Ga3(Ge4.95Si2.05)Se20 (2) (Pc). Their structures feature a {[Ga3(Ge7-xMx)Se20]3-}∞ (M = Si, Sn) polyanionic framework built from the basic functional motif M'Se4 (M' = Ga, Ge, M) tetrahedra, similar to but slightly distorted from that of K3Ga3Ge7Se20. Their NCS structures are verified by the NLO activities. The NLO response of 1 is ∼1/3 times that of the benchmark AgGaS2 under a 2.1 µm laser radiation, while 2 exhibits a weak effect, and both are NLO phase-matchable. Their optical band gaps are measured to be 2.02 and 2.12 eV, and they are transparent in the ranges of 0.61-25 and 0.58-25 µm, respectively.

Combination of a recombinant bacterium with organonitrile-degrading and biofilm-forming capability and a positively charged carrier for organonitriles removal.

The immobilization of organonitrile-degrading bacteria via the addition of biofilm-forming bacteria represents a promising technology for the treatment of organonitrile-containing wastewater, but biofilm-forming bacteria simply mixed with degrading bacteria may reduce the biodegradation efficiency. Nitrile hydratase and amidase genes, which play critical roles in organonitriles degradation, were cloned and transformed into the biofilm-forming bacterium Bacillus subtilis N4 to construct a recombinant bacterium B. subtilis N4/pHTnha-ami. Modified polyethylene carriers with positive charge was applied to promote bacterial adherence and biofilm formation. The immobilized B. subtilis N4/pHTnha-ami was resistant to organonitriles loading shocks and could remove organic cyanide ion with a initial concentration of 392.6 mg/L for 24 h in a moving bed biofilm reactor. The imputed quorum-sensing signal and the high-throughput sequencing analysis of the biofilm indicated that B. subtilis N4/pHTnha-ami was successfully immobilized and became dominant. The successful application of the immobilized recombinant bacterium offers a novel strategy for the biodegradation of recalcitrant compounds.

Treating organic cyanide-containing groundwater by immobilization of a nitrile-degrading bacterium with a biofilm-forming bacterium using fluidized bed reactors.

Organic cyanide are widely used as an ingredient in the production of plastics, synthetic rubbers, polymers, pharmaceuticals and pesticides or used in laboratories and industries as solvents. Although nitrile-containing wastewater is subjected to primary and secondary treatments, residual nitriles may slowly seep and further migrate through groundwater, resulting in the micropollution of groundwater by organic pollutants. In this study, water samples were collected from different study areas in North China during a period of 3y (from 2013 to 2015) and analyzed to evaluate organic cyanide (CN-) contamination in groundwater. Three parallel lab-scale fluidized bed reactors (FBRs) were tested for their ability to remove organic cyanide from groundwater. The organic cyanide concentration in groundwater increased significantly (P < 0.05) from 2013 to 2015. With an optimal hydraulic residence time (HRT) of 54 min, reactor R3 (inoculated with a nitrile-degrading bacterium, BX2, and a biofilm-forming bacterium, M1) effectively removed 99.8% of CN- under steady operation, which was better than that of other reactors. Short-term shutdowns of FBRs had no serious effects on the efficiency of treating organic cyanide. This work demonstrated that the biofilm-forming bacterium could facilitate the fixation of nitrile-degrading bacterium and enhance the efficiency of removing organic cyanide from groundwater.

Diversity of antibiotic resistance genes and encoding ribosomal protection proteins gene in livestock waste polluted environment.

The rapid development and increase of antibiotic resistance are global phenomena resulting from the extensive use of antibiotics in human clinics and animal feeding operations. Antibiotics can promote the occurrence of antibiotic resistance genes (ARGs), which can be transferred horizontally to humans and animals through water and the food chain. In this study, the presence and abundance of ARGs in livestock waste was monitored by quantitative PCR. A diverse set of bacteria and tetracycline resistance genes encoding ribosomal protection proteins (RPPs) from three livestock farms and a river were analyzed through denaturing gradient gel electrophoresis (DGGE). The abundance of sul(I) was 103 to 105 orders of magnitude higher than that of sul(II). Among 11 tet-ARGs, the most abundant was tet(O). The results regarding bacterial diversity indicated that the presence of antibiotics might have an evident impact on bacterial diversity at every site, particularly at the investigated swine producer. The effect of livestock waste on the bacterial diversity of soil was stronger than that of water. Furthermore, a sequencing analysis showed that tet(M) exhibited two genotypes, while the other RPPs-encoding genes exhibited at least three genotypes. This study showed that various ARGs and RPPs-encoding genes are particularly widespread among livestock.

miR-873 suppresses H9C2 cardiomyocyte proliferation by targeting GLI1.

MicroRNAs (miRNAs) are a class of endogenous, non-coding small RNAs that regulate the expression of target genes. Previous studies have suggested that miRNAs are key regulators in cardiovascular systems. This study investigated the role of miR-873 in H9C2 cardiomyocytes by targeting glioma-associated oncogene 1 (GLI1). miR-873 was significantly up-regulated in serum samples from congenital heart disease (CHD) patients compared with those from normal individuals. Furthermore, miR-873 over-expression suppressed H9C2 proliferation and induced cell cycle arrest. Bioinformatic algorithms revealed a predicted target site for miR-873 in the 3'-untranslated region (3'UTR) of GLI1, which was verified using a dual-luciferase reporter assay. qPCR and western blot analysis also showed that miR-873 negatively regulated GLI1 mRNA and protein expression in H9C2 cells. Conversely, GLI1 over-expression partially reversed the growth-inhibitory effect of miR-873. To summarize, our data suggest that miR-873 is a novel miRNA that regulates H9C2 cell proliferation via targeting GLI1, and miR-873 may serve as a new potential biomarker diagnosis in CHD in the future.

Silencing of TBX20 gene expression in rat myocardial and human embryonic kidney cells leads to cell cycle arrest in G2 phase.

Congenital heart diseases (CHDs) are the most common birth defects due to abnormal cardiac development. The T-box 20 (TBX20) gene is a member of the T­box family of transcription factors and encodes TBX20, which is essential for early heart development. In the present study, reduced TBX20 expression was observed in CHD tissue samples compared with normal tissues, and the function of TBX20 in Rattus norvegicus myocardial cells [H9c2(2-1)] and human embryonic kidney cells (HEK293) was investigated. TBX20 was silenced in H9c2 and HEK293 cells via transfection of small interfering RNA and short hairpin RNA duplexes, respectively, and TBX20 mRNA and protein levels were subsequently examined using reverse transcription­quantitative polymerase chain reaction (RT­qPCR) and western blot analysis. Cell proliferation was assessed using a cell counting kit and proliferating cell nuclear antigen expression was determined by western blotting. Analysis of cell apoptosis was achieved by annexin V­fluorescein isothiocyanate/propidium iodide staining and a fluorometric terminal deoxynucleotidyl transferase dUTP nick­end labeling system. Cell cycle analysis was achieved using fluorescence­activated cell sorting, and, an RT­qPCR array was used to profile the expression of TBX20­related genes. Silencing of TBX20 in H9c2 and HEK293 cells significantly inhibited cell proliferation, induced cell apoptosis and led to G2/M cell cycle arrest. A reduction in cyclin B1 mRNA levels and an increase in cyclin­dependent kinase inhibitor 1B mRNA levels was observed, which indicated that cells were arrested in G2 phase. Concurrently, the mRNA levels of GATA binding protein 4 were increased in both cell lines, which may provide an explanation for the abnormal cardiac hypertrophy observed in patients with congenital heart disease. These results suggest that TBX20 is required for heart morphogenesis, and inhibition of TBX20 expression may lead to the suppression of cell proliferation and cell cycle arrest.

Undiagnosed congenital hypothyroidism in a newborn treated with dopamine infusion.

Medications administered during the neonatal period may mask the diagnosis of congenital hypothyroidism. Herein, we report a case of undiagnosed congenital hypothyroidism while the infant was on treatment with dopamine. Given the inhibitory effect of dopamine on thyroid-stimulating hormone, a high index of suspicion for potential congenital hypothyroidism is needed in such neonates.