Microporous Polyelectrolyte Complexes by Hydroplastic Foaming.

Polyelectrolyte complexes (PECs) have emerged as an attractive category of materials for their water processability and some similarities to natural biopolymers. Herein, we employ the intrinsic hydroplasticity of PEC materials to enable the generation of porous structures with the aid of gas foaming. Such foamable materials are fabricated by simply mixing polycation, polyanion, and a UV-initiated chemical foaming agent in an aqueous solution, followed by molding into thin films. The gas foaming of the PEC films can be achieved upon exposure to UV illumination under water, where the films are plasticized and the gaseous products from the photolysis of foaming agents afford the formation, expanding, and merging of numerous bubbles. The porosity and morphology of the resulting porous films can be customized by tuning film composition, foaming conditions, and especially the degree of plasticizing effect, illustrating the high flexibility of this hydroplastic foaming method. Due to the rapid initiation of gas foaming, the present method enables the formation of porous structures via an instant one-step process, much more efficient than those existing strategies for porous PEC materials. More importantly, such a pore-forming mechanism might be extended to other hydroplastic materials (e.g., biopolymers) and help to yield hydroplasticity-based processing strategies.

First Report of the Colletotrichum siamense species complex causing Anthracnose on Photinia × fraseri Dress in China.

Photinia × fraseri Dress is mainly distributed in the southeast and east of Asia and North America and has been widely cultivated in China. In summer 2018, an anthracnose disease of P. × fraseri Dress was found in a park in Nanjing City, China. Disease leaves showed small, round, light reddish brown spots in the early stage of infection that gradually expanded into round spots, with light gray in centers and brown edges. Fresh lesions were cut into 2-3 mm2 sections, sterilized with 75% ethanol for 30 s, followed by 1% NaClO for 90 s, washed with sterile water 3 times, and placed on potato dextrose agar (PDA) with 0.1 mg/mL ampicillin at 25°C. Colonies of a representative strain "HDSN2-1" were white to greenish grey, and the daily growth rate was 9.5 to10.5 mm/day. Aerial mycelium was grayish white, dense, and cottony, with visible conidial masses at the inoculum point. Conidia were one-celled, smooth-walled, hyaline, with obtuse to rounded ends, with a size of 12.8 to 18.4 × 4.5 to 6.8 µm. Appressoria were one-celled, brown, thick-walled, ellipsoidal, and 7.3 to 10.3 × 5.4 to 6.97µm. The morphological characteristics of HDSN2-1 matched those of the Colletotrichum gloeosporioides species complex (Weir et al. 2012). For further identification, DNA was extracted from HDSN2-1 mycelium and the internal transcribed spacer (ITS) region and partial sequences of ß-tubulin (TUB2), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), chitin synthase (CHS-1) and calmodulin genes(CAL) were amplified by PCR, and sequenced with primers ITS1/ITS4, TubF1/TubR1, GDF/GDR, CHS-79F/CHS-345R, and CAL1C/CAL2C, respectively(Weir et al. 2012). The sequences were deposited in GenBank [Accession nos: MN889417, MN894596, MN894597, MN894598, MN894599]. A phylogenetic tree was constructed using the maximum likelihood/span>method with concatenated sequences (ITS, TUB2, GAPDH, CHS and CAL) (Zhu et al. 2019). Analyses conducted in MEGA7 placed HDSN2-1 in the C. siamense clade, which includes ex-type ICMP 18578. Pathogenicity of HDSN2-1 was verified on leaves from 7 healthy 8-year-old P. × fraseri and inoculated with either 5-mm mycelial plugs from the edge of 5-day old cultures on PDA or 10 µL of spore suspension (106 conidia/mL),15 healthy plants（8-year-old）were used in 5 repetitions (5 for control, and 10 for the pathogenicity test) in the same way. Controls were treated with PDA plugs or sterile dH2O. The leaves were incubated at 25 ℃ and the inoculated plants were kept in a greenhouse (relative humidity > 85%, 25 ± 1°C). Symptoms were not observed on control plants. Fungal isolates from the symptomatic plants showed the same morphological characteristics with HDSN2-1. C. siamense is a common fungal pathogen of many plants. For example, it was previously reported infecting apples and citrus fruits ( Abirammi et al. 2019). This is the first report of anthracnose of P. × fraseri caused by C. siamense in China. References: Weir B.S., et al. 2012. Stud. Mycol. 73:115. https://doi.org/10.3114/sim0011 Zhu, L. H. et al. 2019. Plant Dis.103: 1431. https://doi.org/10.1094/PDIS-12-18-2265-PDN. Abirammi, K., et al. 2019. Plant Dis.103:768. https://doi.org/10.1094/PDIS-09-18-1489-PDN Funding: This research was financially supported by the National Key Research and Development Programme of China (2017YFD0600104).

Cordycepin inhibits glioma growth by downregulating PD-L1 expression via the NOD-like receptor/NFKB1/STAT1 axis.

Glioma is a serious primary malignant tumor of the human central nervous system with a poor prognosis and a high recurrence rate; however, inhibition of immune checkpoints can greatly improve the survival rate of patients. The purpose of this study was to investigate the regulation of PD-L1 by cordycepin and the mechanism of its anti-tumor action. The results of previous studies indicate that cordycepin has good anti-proliferative and anti-migratory activities and can induce apoptosis in U251 and T98G cells in vitro. Here, transcriptome sequencing showed that cordycepin may exert anti-tumor effects through the NOD-like receptor signaling pathway. Further intervention with BMS-1, a small molecule inhibitor of PD-L1, was used to explore whether inhibition of PD-L1 affected the regulation of the NOD-like receptor signaling pathway by cordycepin. Mechanistically, on the one hand, cordycepin regulated the expression of NFKB1 and STAT1 through the NOD-like receptor signaling pathway, thereby inhibiting the expression of PD-L1. In addition, inhibition of PD-L1 enhanced the regulation by cordycepin of the NOD-like receptor signaling pathway. On the other hand, cordycepin directly upregulated expression of STAT1 and downregulated that of PD-L1. In vivo studies further showed that cordycepin could downregulate expression of PD-L1 and NFKB1 and upregulate that of STAT1 in glioma xenograft tumor tissues, consistent with the results of in vitro studies. The results suggest that cordycepin may down-regulate the expression of PD-L1 through NOD-like receptor signaling pathway and NFKB signaling pathway, thereby inhibiting the immune escape of glioma, and can be developed as a PD-L1 inhibitor. Our results therefore provide a theoretical foundation for the use of cordycepin in treatment of glioma and enrich our understanding of its pharmacological mechanism.

Characteristics and pathogenesis of chemokines in the post-stroke stage.

Chemokines, as small molecular proteins, play a crucial role in the immune and inflammatory responses after stroke. A large amount of evidence showed chemokines and their receptors were increasingly recognized as potential targets for stroke treatment, which were involved in the processing of neovascularization, neurogenesis, and neural network reconstruction. In this review, we summarized the characteristics of chemokine alterations throughout the post-stroke nerve repair phase to gain insight into the pathological mechanisms of chemokines and find effective therapeutic targets for stroke.

Development and Utilization of Corn Processing by-Products: A Review.

As an important food crop, corn has an important impact on people's lives. The processing of corn produces many by-products, such as corn gluten meal, corn husk, and corn steep liquor, which are rich in protein, oil, carbohydrates, and other nutrients, all of which are inexpensive. Their accumulation in large quantities during the production process not only results in a burden on the environment but also the loss of potentially valuable food materials that can be processed. In fact, the by-products of corn processing have been partially used in functional foods, nutrients, feed, and other industries. There is no doubt that the secondary utilization of these by-products can not only solve the problem of waste pollution caused by them, but also produce high value-added products and improve the economic benefits of corn. This paper describes in detail the processing and higher-value utilization of the five main by-products: corn gluten meal, corn husks, corn steep liquor, corn germ, and fuel ethanol by-product. The utilization status of corn processing by-products was discussed roundly, and the development trend of corn processing by-products in China and other countries was analyzed, which provided the reference for the development of the corn deep processing industry.

An experimental and theoretical study of optimized selection and model reconstruction for ammonium nitrate pyrolysis.

Ammonium nitrate (AN) is a commonly-used industrial raw material in industrial explosives and fertilizers areas. However, as an energetic material, its danger exists during the production, transportation, and storage, resulting in a large number of accidents involving personal injury and property loss. To obtain the accurate kinetic triplet parameters of AN thermal decomposition, a series of thermogravimetry analysis (TGA) experiments was conducted with four different heating rates. Activation energies were calculated by different isoconversional methods Then the kinetic triplet of AN pyrolysis was optimized using a combination of experimental and simulant methods. Combined with the traditional model-free and model-fitting approaches, the experimental kinetic model for AN pyrolysis was optimized and then reconstructed. Through the pyrolysis reaction of AN, a reliable methodology for processing TGA data of hazardous material is proposed in the paper, and the kinetic parameters can be accurately obtained by using such a kinetics method.

Application of optical tweezers in the research of molecular interaction between lymphocyte function associated antigen-1 and its monoclonal antibody.

Lymphocyte function associated antigen-1 (CD11a/CD18, LFA-1) plays an important role in the structure of the immunological synapse and is required for efficient lysis of cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. To study the activation mode of LFA-1 on the NK cell surface, optical tweezers were used in the work. As an emerging technology, optical tweezers are widely used to manipulate microscopic objects and measure the forces of molecular interactions in the field of biological research. In our study, a new platform was constructed to study the single molecular behavior of receptor on cell surface using optical tweezers. Based on the platform, the interaction between an NK cell and a polystyrene microsphere coated with anti-LFA-1 antibody was observed. The result confirmed that the adhesion forces between an NK cell and a polystyrene bead were time-dependent. According to our findings, we propose that anti-LFA-1 antibody may cause the clustering of LFA-1 on NK cell surface.