盐生植物海马齿离体再生

建立盐生植物海马齿（Sesuvium portulacastrum）的离体再生体系,为其生物技术改良奠定基础。以海马齿叶片、茎和腋芽为外植体, 在不同激素配比的培养基上进行愈伤组织诱导、继代培养以及不定芽的分化和生根培养。结果表明： 最适愈伤组织诱导的外植体为叶片, 其次为幼嫩的茎段和腋芽。以叶片为外植体, 愈伤组织诱导率最高的培养基为MS＋2.0mg·L^–12, 4-D ＋ 0.5 mg·L^–16-BA ＋ 3%sucrose; 芽分化最适培养基为MS ＋ 1.0 mg·L^–1 2, 4-D ＋ 0.2 mg·L^–1 6-BA ＋ 3% sucrose;生根最适培养基为MS ＋ 3%sucrose ＋ 0.1%AC。炼苗移栽后, 成活率可达80%。     

The mechanism for the radioprotective effects of zymosan‐A in mice

It proved that Zymosan‐A protected the haematopoietic system from radiation‐induced damage via Toll‐Like Receptor2 in our previous study. In this study, we investigated the potential mechanism for the radioprotective effects of Zymosan‐A. The mice were treated with Zymosan‐A (50 mg/kg, dissolved in NS) via peritoneal injection 24 and 2 hours before ionizing radiation. Apoptosis of bone marrow cells and the levels of IL‐6, IL‐12, G‐CSF and GM‐CSF were evaluated by flow cytometry assay. DNA damage was determined by γ‐H2AX foci assay. In addition, RNA sequencing was performed to identify differentially expressed genes (DEGs). Zymosan‐A protected bone marrow cells from radiation‐induced apoptosis, up‐regulated IL‐6, IL‐12, G‐CSF and GM‐CSF in bone marrow cells. Zymosan‐A also protected cells from radiation‐induced DNA damage. Moreover, RNA sequencing analysis revealed that Zymosan‐A induced 131 DEGs involved in the regulation of immune system process and inflammatory response. The DEGs were mainly clustered in 18 KEGG pathways which were also associated with immune system processes. Zymosan‐A protected bone marrow cells from radiation‐induced apoptosis and up‐regulated IL‐6, IL‐12, G‐CSF and GM‐CSF. Moreover, Zymosan‐A might also exhibit radioprotective effects through regulating immune system process and inflammatory response. These results provided new knowledge regarding the radioprotective effect of Zymosan‐A.     

酚类物质对两种潜伏炭疽菌生长和繁殖的影响

通过测定丹宁、间苯二酚、邻苯二酚、绿原酸和咖啡因,作者对潜伏侵染在香蕉果实中的芭蕉炭疽菌Colletotrichum musae(Berk & Curt)Arx和芒果果实中的胶孢炭疽菌C.gloeosporioides Penz.的分生孢子萌发,附着胞和分生孢子的形成,以及菌丝体生长的影响进行了研究。结果表明,这几种酚类物质,在一定浓度下,可抑制两种炭疽菌的生长和发育,其中邻苯二酚对芭蕉炭疽菌的作用浓度最低,而间苯二酚对胶孢炭疽菌的作用浓度最低,丹宁则对两种菌的作用浓度最高,在一定浓度下影响着附着胞的形成。     

The glycosyltransferase UGT76B1 modulates N-hydroxy-pipecolic acid homeostasis and plant immunity

The tradeoff between growth and defense is a critical aspect of plant immunity. Therefore, the plant immune response needs to be tightly regulated. Salicylic acid (SA) is an important plant hormone regulating defense against biotrophic pathogens. Recently, N-hydroxy-pipecolic acid (NHP) was identified as another regulator for plant innate immunity and systemic acquired resistance (SAR). Although the biosynthetic pathway leading to NHP formation is already been identified, how NHP is further metabolized is unclear. Here, we present UGT76B1 as a uridine diphosphate-dependent glycosyltransferase (UGT) that modifies NHP by catalyzing the formation of 1-O-glucosyl-pipecolic acid in Arabidopsis thaliana. Analysis of T-DNA and clustered regularly interspaced short palindromic repeats (CRISPR) knock-out mutant lines of UGT76B1 by targeted and nontargeted ultra-high performance liquid chromatography coupled to high-resolution mass spectrometry (UHPLC-HRMS) underlined NHP and SA as endogenous substrates of this enzyme in response to Pseudomonas infection and UV treatment. ugt76b1 mutant plants have a dwarf phenotype and constitutive defense response which can be suppressed by loss of function of the NHP biosynthetic enzyme FLAVIN-DEPENDENT MONOOXYGENASE 1 (FMO1). This suggests that elevated accumulation of NHP contributes to the enhanced disease resistance in ugt76b1. Externally applied NHP can move to distal tissue in ugt76b1 mutant plants. Although glycosylation is not required for the long-distance movement of NHP during SAR, it is crucial to balance growth and defense.     

BAC- and oligo-FISH mapping reveals chromosome evolution among Vigna angularis,V. unguiculata,and Phaseolus vulgaris

Chromosoma - Cytogenomic resources have accelerated synteny and chromosome evolution studies in plant species, including legumes. Here, we established the first cytogenetic map of V. angularis (Va,...     

Boosting the Activity of BaCo0.4Fe0.4Zr0.1Y0.1O3−δ Perovskite for Oxygen Reduction Reactions at Low‐to‐Intermediate Temperatures through Tuning B‐Site Cation Deficiency

Doped perovskite oxides with the general formula of A_xA′_1?xB_yB′_1?yO₃ have been extensively exploited as the cathode materials of solid oxide fuel cells (SOFCs), but the performance at low‐to‐medium temperatures still needs improvement. BaCo_0.4Fe_0.4Zr_0.1Y_0.1O_3?δ (BCFZY) has been recently reported to show promising oxygen reduction reaction (ORR) activity under SOFCs' operating conditions. Here, it is reported that the activity of BCFZY can be further boosted via introducing a slight B‐site cation deficiency into the oxide lattice, and such an improvement is assigned to an increase in oxygen mobility that brings enhancement in both surface exchange and bulk diffusion kinetics. Specifically, materials with the nominal composition of Ba(Co_0.4Fe_0.4Zr_0.1Y_0.1)_0.975O_3?δ and Ba(Co_0.4Fe_0.4Zr_0.1Y_0.1)_0.95O_3?δ show significantly improved activity for ORR at reduced temperatures with the area specific resistances of 0.011 and 0.024 Ω cm² at 600 °C, as a comparison of 0.042 Ω cm² for the cation stoichiometric BCFZY. Excessive B‐site deficiencies, however, lead to the formation of impurity phases, which cause a block for charge transfer and, consequently, a reduction in electrode performance. Introducing a B‐site cation deficiency is a promising way to optimize the activity of perovskite oxides for ORR at reduced temperatures, but the degree of deficiency shall be carefully tuned.     

A data-driven multi-fidelity simulation optimization for medical staff configuration at an emergency department in Hong Kong

Flexible Services and Manufacturing Journal - Overcrowding at emergency departments in Hong Kong has been a critical issue for hospital managers recently. In this study, we focus on optimizing the...     

Immunocytochemistry of Kaposi's sarcoma-like tumor cells from pigtailed macaques with simian AIDS

Some macaques infected with SRV-2 developed SAIDS and RF, a Kaposi's sarcoma (KS)-like tumor. We investigated the immunophenotypic markers of this SAIDS-associated retroperitoneal fibromatosis (RF). RF tumor is characterized by proliferation of spindle cells accompanying inflammatory cell infiltrates, fibroblasts, and endothelial cells. RF spindle cells in tumor tissues revealed several immunobiologic characteristics similar to vascular smooth-muscle cells or myofibroblasts based on positive immunoreactivity of smooth-muscle α-actin and desmin. The majority of cultured RF spindle cells also expressed specific markers for vascular smooth muscle. These results suggest that the RF spindle cells are derived from vascular smooth-muscle cells. Furthermore, RF tissues and cells were persistently infected with SRV-2, which may play an important role in viral etiology of AIDS-associated neoplasm in this macaque model.