The characteristics of soil salinization effects on nitrogen mineralization and nitrification in upland fields

The influence of soil salinization on nitrogen (N) transformation is largely unknown, which impedes the reasonable management of N in saline fields. A comprehensive meta-analysis was thus conducted to evaluate the effects of salinity and relative soil physicochemical properties on net N mineralization and nitrification in upland soils. Results showed that effects of salinity on the net-N mineralization rate (Min) and nitrification rate (Nit) changed with the salinity level and incubation time. Generally, the inhibitory effect of salt on Min and Nit decreased gradually with incubation time. At 14–16 days of soil incubation, significant stimulatory effects on Min were observed in middle-level (ECe: 12–16 dS m-1) and high-level (ECe >16 dS m-1) saline soils, and on Nit in low-level (ECe: 4–12 dS m-1) saline soils. Regression analysis revealed that the effects of soil organic carbon (SOC), total N (TN), C/N, pH, and clay content on Min and Nit were closely related to salinity levels. Nit at 5–7 days of soil incubation first enhanced and then decreased with C/N increase, and the threshold value was 34.7. The effect of pH on Nit changed with salinity levels, and shifted from stimulation to inhibition with increasing pH. Min at 5–7 days of soil incubation in middle-level group first increased with increasing pH, and decreased when pH was higher than 8.1. Salinization deeply affected soil properties, which further influenced N turnover via alteration of the availability of substrates and microbial biomass and activities. Our findings suggest that the influence of salinity on soil N turnover closely related with salinity level, and salinity level should be considered fully when optimizing N management in saline upland fields

Molecular dynamics investigations of structural and functional changes in Bcl-2 induced by the novel antagonist BDA-366

<p>Apoptosis is a fundamental biological phenomenon, in which anti- or proapoptotic proteins of the Bcl-2 family regulate a committed step. Overexpression of Bcl-2, the prototypical antiapoptotic protein in this family, is associated with therapy resistance in various human cancers. Accordingly, Bcl-2 inhibitors intended for cancer therapy have been developed, typically against the BH3 domain. Recent experimental evidences have shown that the antiapoptotic function of Bcl-2 is not immutable, and that BDA-366, a novel antagonist of the BH4 domain, converts Bcl-2 from a survival molecule to an inducer of cell death. In this study, the underlying mechanisms of this functional conversion were investigated by accelerated molecular dynamics simulation. Results revealed that Pro127 and Trp30 in the BH4 domain rotate to stabilize BDA-366 via π-π interactions, and trigger a series of significant conformational changes of the α3 helix. This rearrangement blocks the hydrophobic binding site (HBS) in the BH3 domain and further prevents binding of BH3-only proteins, which consequently allows the BH3-only proteins to activate the proapoptotic proteins. Analysis of binding free energy confirmed that BDA-366 cross-inhibits BH3-only proteins, implying negative cooperative effects across separate binding sites. The newly identified blocked conformation of the HBS along with the open to closed transition pathway revealed by this study advances the understanding of the Bcl-2 transition from antiapoptotic to proapoptotic function, and yielded new structural insights for novel drug design against the BH4 domain.</p> <p>Communicated by Ramaswamy H. Sarma</p> <p>The ability of the small molecule BDA-366 to convert Bcl-2 from an antiapoptotic to a proapoptotic molecule was investigated by accelerated molecular dynamics simulation. Results show that BDA-366 blocks or reduces the affinity of Bcl-2 for BH3-only proteins like Bid via negative cooperative effects, thereby releasing such proteins and unleashing their proapoptotic effects.</p

In Vivo Metabolic Response upon Exposure to Gold Nanorod Core/Silver Shell Nanostructures: Modulation of Inflammation and Upregulation of Dopamine

With the increasing applications of silver nanoparticles (Ag NPs), the concerns of widespread human exposure as well as subsequent health risks have been continuously growing. The acute and chronic toxicities of Ag NPs in cellular tests and animal tests have been widely investigated. Accumulating evidence shows that Ag NPs can induce inflammation, yet the overall mechanism is incomplete. Herein, using gold nanorod core/silver shell nanostructures (Au@Ag NRs) as a model system, we studied the influence on mice liver and lungs from the viewpoint of metabolism. In agreement with previous studies, Au@Ag NRs&rsquo; intravenous exposure caused inflammatory reaction, accompanying with metabolic alterations, including energy metabolism, membrane/choline metabolism, redox metabolism, and purine metabolism, the disturbances of which contribute to inflammation. At the same time, dopamine metabolism in liver was also changed. This is the first time to observe the production of dopamine in non-neural tissue after treatment with Ag NPs. As the upregulation of dopamine resists inflammation, it indicates the activation of antioxidant defense systems against oxidative stress induced by Au@Ag NRs. In the end, our findings deepened the understanding of molecular mechanisms of Ag NPs-induced inflammation and provide assistance in the rational design of their biomedical applications

A New Dataset and Boundary-Attention Semantic Segmentation for Face Parsing

Face parsing has recently attracted increasing interest due to its numerous application potentials, such as facial make up and facial image generation. In this paper, we make contributions on face parsing task from two aspects. First, we develop a high-efficiency framework for pixel-level face parsing annotating and construct a new large-scale Landmark guided face Parsing dataset (LaPa). It consists of more than 22,000 facial images with abundant variations in expression, pose and occlusion, and each image of LaPa is provided with an 11-category pixel-level label map and 106-point landmarks. The dataset is publicly accessible to the community for boosting the advance of face parsing.1 Second, a simple yet effective Boundary-Attention Semantic Segmentation (BASS) method is proposed for face parsing, which contains a three-branch network with elaborately developed loss functions to fully exploit the boundary information. Extensive experiments on our LaPa benchmark and the public Helen dataset show the superiority of our proposed method

Correction to: Highly sensitive and robust peroxidase-like activity of Au–Pt core/shell nanorod-antigen conjugates for measles virus diagnosis

After publication of the original article [1], an error was noted in the author affiliation. Lin Long is also affiliated to the College of Opto-electronic Engineering, Zaozhuang University, Zaozhuang, China, which is her first affiliation