Nitrate transporters in leaves and their potential roles in foliar uptake of nitrogen dioxideâ€

While plant roots are specialized organs for the uptake and transport of water and nutrients, the absorption of gaseous or liquid mineral elements by aerial plant parts has been recognized since more than one century. Nitrogen (N) is an essential macronutrient which generally absorbed either as nitrate (NO(−)(3)) or ammonium (NH(+)(4)) by plant roots. Gaseous nitrogen pollutants like N dioxide (NO(2)) can also be absorbed by plant surfaces and assimilated via the NO(−)(3) assimilation pathway. The subsequent NO(−)(3) flux may induce or repress the expression of various NO(−)(3)-responsive genes encoding for instance, the transmembrane transporters, NO(−)(3)/NO(−)(2) (nitrite) reductase, or assimilatory enzymes involved in N metabolism. Based on the existing information, the aim of this review was to theoretically analyze the potential link between foliar NO(2) absorption and N transport and metabolism. For such purpose, an overview of the state of knowledge on the NO(−)(3) transporter genes identified in leaves or shoots of various species and their roles for NO(−)(3) transport across the tonoplast and plasma membrane, in addition to the process of phloem loading is briefly provided. It is assumed that a NO(2)-induced accumulation of NO(−)(3)/NO(−)(2) may alter the expression of such genes, hence linking transmembrane NO(−)(3) transporters and foliar uptake of NO(2). It is likely that NRT1/NRT2 gene expression and species-dependent apoplastic buffer capacity may be also related to the species-specific foliar NO(2) uptake process. It is concluded that further work focusing on the expression of NRT1 (NRT1.1, NRT1.7, NRT1.11, and NRT1.12), NRT2 (NRT2.1, NRT2.4, and NRT2.5) and chloride channel family genes (CLCa and CLCd) may help us elucidate the physiological and metabolic response of plants fumigated with NO(2)

Silica-supported quinolinium tribromide: a recoverable solid brominating reagent for regioselective monobromination of aromatic amines

Silica-supported quinolinium tribromide was synthesized and found to be an efficient, stable, and recoverable solid brominating reagent for the regioselective monobromination of aromatic amines. This protocol has advantages of high yield, mild condition and simple work-up procedure

Bifidobacterium mitigates autoimmune hepatitis by regulating IL-33-induced Treg/Th17 imbalance via the TLR2/4 signaling pathway

The present work aims to evaluate the efficacy of Live Combined Bifidobacterium, Lactobacillus and Enterococcus Capsules (LCBLECs), a probiotic drug containing Bifidobacterium, in the treatment of autoimmune hepatitis (AIH). In this study, a mouse model of experimental autoimmune hepatitis (EAH) was established to investigate the effects of LCBLECs on AIH. The results showed that LCBLECs improved dysbiosis of gut microbiota, reduced liver injury, restored liver function, and maintained Treg/Th17 balance in EAH mice. In addition, LCBLECs restored Treg/Th17 balance in EAH mice by downregulating IL-33 production. Besides, LCBLECs also suppress IL-33 upregulation in EAH mice by inhibiting the TLR2/4 signaling pathway. Furthermore, LCBLECs also mitigated dysbiosis of gut microbiota and enhanced the efficacy of conventional treatment for AIH patients. To sum up, our findings revealed that LCBLECs exerted therapeutic effects on EAH mice by improving Treg/Th17 imbalance in an IL-33-dependent manner via the TLR2/4 signaling pathway and relieved the clinical symptoms of AIH patients, indicating Bifidobacterium supplementation with LCBLECs might be a potential adjuvant therapy for AIH treatment

Effective and Robust Detection of Adversarial Examples via Benford-Fourier Coefficients

Adversarial examples have been well known as a serious threat to deep neural networks (DNNs). In this work, we study the detection of adversarial examples, based on the assumption that the output and internal responses of one DNN model for both adversarial and benign examples follow the generalized Gaussian distribution (GGD), but with different parameters (i.e., shape factor, mean, and variance). GGD is a general distribution family to cover many popular distributions (e.g., Laplacian, Gaussian, or uniform). It is more likely to approximate the intrinsic distributions of internal responses than any specific distribution. Besides, since the shape factor is more robust to different databases rather than the other two parameters, we propose to construct discriminative features via the shape factor for adversarial detection, employing the magnitude of Benford-Fourier coefficients (MBF), which can be easily estimated using responses. Finally, a support vector machine is trained as the adversarial detector through leveraging the MBF features. Extensive experiments in terms of image classification demonstrate that the proposed detector is much more effective and robust on detecting adversarial examples of different crafting methods and different sources, compared to state-of-the-art adversarial detection methods

Lipopolysaccharide-induced immune stress negatively regulates broiler chicken growth via the COX-2-PGE2-EP4 signaling pathway

AimsImmune stress in broiler chickens is characterized by the development of persistent pro-inflammatory responses that contribute to degradation of production performance. However, the underlying mechanisms that cause growth inhibition of broilers with immune stress are not well defined.MethodsA total of 252 1-day-old Arbor Acres(AA) broilers were randomly allocated to three groups with six replicates per group and 14 broilers per replicate. The three groups comprised a saline control group, an Lipopolysaccharide (LPS) (immune stress) group, and an LPS and celecoxib group corresponding to an immune stress group treated with a selective COX-2 inhibitor. Birds in LPS group and saline group were intraperitoneally injected with the same amount of LPS or saline from 14d of age for 3 consecutive days. And birds in the LPS and celecoxib group were given a single intraperitoneal injection of celecoxib 15 min prior to LPS injection at 14 d of age.ResultsThe feed intake and body weight gain of broilers were suppressed in response to immune stress induced by LPS which is an intrinsic component of the outer membrane of Gram-negative bacteria. Cyclooxygenase-2 (COX-2), a key enzyme that mediates prostaglandin synthesis, was up-regulated through MAPK-NF-κB pathways in activated microglia cells in broilers exposed to LPS. Subsequently, the binding of prostaglandin E2 (PGE2) to the EP4 receptor maintained the activation of microglia and promoted the secretion of cytokines interleukin-1β and interleukin-8, and chemokines CX3CL1 and CCL4. In addition, the expression of appetite suppressor proopiomelanocortin protein was increased and the levels of growth hormone-releasing hormone were reduced in the hypothalamus. These effects resulted in decreased expression of insulin-like growth factor in the serum of stressed broilers. In contrast, inhibition of COX-2 normalized pro-inflammatory cytokine levels and promoted the expression of Neuropeptide Y and growth hormone-releasing hormone in the hypothalamus which improved the growth performance of stressed broilers. Transcriptomic analysis of the hypothalamus of stressed broilers showed that inhibition of COX-2 activity significantly down-regulated the expression of the TLR1B, IRF7, LY96, MAP3K8, CX3CL1, and CCL4 genes in the MAPK-NF-κB signaling pathway.ConclusionThis study provides new evidence that immune stress mediates growth suppression in broilers by activating the COX-2-PGE2-EP4 signaling axis. Moreover, growth inhibition is reversed by inhibiting the activity of COX-2 under stressed conditions. These observations suggest new approaches for promoting the health of broiler chickens reared in intensive conditions

Analysis of Tidal Current Energy Technology and Industry in China

The tidal resource is abundant and the research, development and demonstration of tidal current energy technology have made great progress in China. The accumulated installed capacity of tidal turbines is more than 3MW, which is leading internationlly. The carbon emissions peak and carbon neutrality strategy put forward in China requires the transition of energy structure, brings an important opportunity for the development of tidal current energy. The representative tidal current energy technologies are analyzed according to the research focus based on CNKI database. And the patents on tidal current energy technologies are also analyzed. Then, the current and forcast of the levelized cost of energy (LCOE) for tidal current energy in China are given. Finally, the pathway and incentive policies needed are suggested

Self-assembly of versatile tubular-like In 2 O 3 nanostructures

Abstract Versatile indium oxide tubular nanostructures (well-aligned nanotube arrays, flower-like tubular structures, and square nanotubes) were fabricated by a facile and reliable chemical vapor deposition (CVD) technique, taking advantage of the self-assembly property and substrate-induced epitaxial growth mechanism. The technique has a few advantages, such as low growth temperature, nonexistence of catalyst, template-free synthesis, direct bonding to the semiconductor substrates, etc. This strategy might extend the approach of synthesizing desirable nanostructures of other important low-melting metal oxides for potential applications