MFC/NFC-Based Foam/Aerogel for Production of Porous Materials: Preparation,Properties and Applications

Nanofibrillated cellulose and microfibrillated cellulose are potential raw materials separated from plant fibers with a high aspect ratio and excellent mechanical properties, which can be applied in various fields (packaging, medicine, etc.). They have unique advantages in the preparation of aerogels and foams, and have attracted widespread attention in recent years. Cellulose-based porous materials have good biodegradability and biocompatibility, while high porosity and high specific surface area endow them with strong mechanical properties and liquid retention performance, which can be used in wall construction, sewage treatment and other fields. At present, the preparation method of this material has been widely reported, however, due to various process problems, the actual production has not been realized. In this paper, we summarize the existing technical problems and main solutions; in the meantime, two stable systems and several drying processes are described, and the application potential of cellulose-based porous materials in the future is described, which provides a reference for subsequent research.     

Dielectric ceramics/TiO2/single-crystalline silicon nanomembrane heterostructure for high performance flexible thin-film transistors on plastic substrates

A dielectric ceramics/TiO₂/single-crystalline silicon nanomembrane (SiNM) heterostructure is designed and fabricated for high performance flexible thin-film transistors (TFTs). Both the dielectric ceramics (Nb₂O₃–Bi₂O₃–MgO) and TiO₂ are deposited by radio frequency (RF) magnetron sputtering at room temperature, which is compatible with flexible plastic substrates. And the single-crystalline SiNM is transferred and attached to the dielectric ceramics/TiO₂ layers to form the heterostructure. The experimental results demonstrate that the room temperature processed heterostructure has high quality because: (1) the Nb₂O₃–Bi₂O₃–MgO/TiO₂ heterostructure has a high dielectric constant (∼76.6) and low leakage current. (2) The TiO₂/single-crystalline SiNM structure has a relatively low interface trap density. (3) The band gap of the Nb₂O₃–Bi₂O₃–MgO/TiO₂ heterostructure is wider than TiO₂, which increases the conduction band offset between Si and TiO₂, lowering the leakage current. Flexible TFTs have been fabricated with the Nb₂O₃–Bi₂O₃–MgO/TiO₂/SiNM heterostructure on plastic substrates and show a current on/off ratio over 10⁴, threshold voltage of ∼1.2 V, subthreshold swing (SS) as low as ∼0.2 V dec⁻¹, and interface trap density of ∼10¹² eV⁻¹ cm⁻². The results indicate that the dielectric ceramics/TiO₂/SiNM heterostructure has great potential for high performance TFTs.

Dielectric ceramics/TiO2/single-crystalline silicon nanomembrane heterostructure for high performance flexible thin-film transistors.     

An In Vivo Rat Model of Artery Buckling for Studying Wall Remodeling

Theoretical modeling and in vitro experiments have demonstrated that arterial buckling is a possible mechanism for the development of artery tortuosity. However, there has been no report of whether artery buckling develops into tortuosity, partially due to the lack of in vivo models for long-term studies. The objective of this study was to establish an in vivo buckling model in rat carotid arteries for studying arterial wall remodeling after buckling. Rat left carotid arteries were transplanted to the right carotid arteries to generate buckling under in vivo pressure and were maintained for 1 week to examine wall remodeling and adaptation. Our results showed that a significant buckling was achieved in the carotid arterial grafts with altered wall stress. Cell proliferation and matrix metalloprotinease-2 (MMP-2) expression in the buckled arteries increased significantly compared with the controls. The tortuosity level of the grafts also slightly increased 1 week post-surgery, while there was no change in vessel dimensions, blood pressure, and blood flow velocity. The artery buckling model provides a useful tool for further study of the adaptation of arteries into tortuous shapes.     

Preparation and characterization of a nanolignin phenol formaldehyde resin by replacing phenol partially with lignin nanoparticles

A new strategy for the preparation of a lignin phenol formaldehyde (LPF) resin has been developed. Nanolignin with high specific surface area and porous structure with an average particle size of about 300 nm was prepared, used as the raw material to substitute phenol partially, and combined with formaldehyde to produce a wood adhesive. The results show that the artificial board prepared with a nanolignin phenol formaldehyde (NLPF) resin with nanolignin substitution degree of 40% wt for phenol could give a dry bond strength of 1.30 ± 0.08 MPa, which is 1.85 times that of the Chinese national grade 1 plywood standard (0.7 MPa) and whose formaldehyde emission of 0.40 mg L⁻¹ meets the standard of GB/T 14732-2006 (E₀, 0.5 mg L⁻¹). TG and DSC analyses show that the replacement of phenol by nanolignin could improve the thermal stability and decrease the curing temperature of the prepared lignin-based resin, with the residual ratio of 40% NLPF being 45% wt at 800 °C and the curing exothermic peak being 145.4 °C, which are much better than that of the 40% LPF resin with the residual ratio being 40% wt and the exothermic peak being 186 °C, respectively. The present study provides a new thought for preparation of LPF resins.

A new strategy for the preparation of a lignin phenol formaldehyde (LPF) resin.     

宝鸡地区2007～2013年新生儿先天性甲状腺功能低下症检测分析

目的开展新生儿先天性甲状腺功能低下症（CH）筛查,对阳性患儿给予干预,以降低残疾儿的发生率,提高我市人口素质。方法应用ELISA时间分辨荧光（DELFIA）多标记免疫分析法检测新生儿促甲状腺素（TSH）浓度筛查CH。结果筛查新生儿TSH 203009例,确诊CH84例,阳性率为1／2417（84／203009）。结论应用DELFIA法检测新生儿促甲状腺素是我国新生儿筛查的主流检测方法,适用于我市目前新生儿筛查工作的发展。2013年我市CH阳性率为1：2288,接近全国水平。     

Alteration of fecal tryptophan metabolism correlates with shifted microbiota and may be involved in pathogenesis of colorectal cancer

BACKGROUNDGut tryptophan (Trp) metabolites are produced by microbiota and/or host metabolism. Some of them have been proven to promote or inhibit colorectal cancer (CRC) in vitro and animal models. We hypothesized that there is an alteration of gut Trp metabolism mediated by microbiota and that it might be involved in the pathogenesis of cancer in patients with CRC.AIMTo investigate the features of Trp metabolism in CRC and the correlation between fecal Trp metabolites and gut microbiota.METHODSSeventy-nine patients with colorectal neoplastic lesions (33 with colon adenoma and 46 with sporadic CRC) and 38 healthy controls (HCs) meeting the inclusion and exclusion criteria were included in the study. Their demographic and clinical features were collected. Fecal Trp, kynurenine (KYN), and indoles (metabolites of Trp metabolized by gut microbiota) were examined by ultraperformance liquid chromatography coupled to tandem mass spectrometry. Gut barrier marker and indoleamine 2,3-dioxygenase 1 (IDO1) mRNA were analyzed by quantitative real-time polymerase chain reaction. Zonula occludens-1 (ZO-1) protein expression was analyzed by immunohistochemistry. The gut microbiota was detected by 16S ribosomal RNA gene sequencing. Correlations between fecal metabolites and other parameters were examined in all patients.RESULTSThe absolute concentration of KYN [1.51 (0.70, 3.46) nmol/g vs 0.81 (0.64, 1.57) nmol/g, P = 0.036] and the ratio of KYN to Trp [7.39 (4.12, 11.72) × 10^-3 vs 5.23 (1.86, 7.99) × 10^-3, P = 0.032] were increased in the feces of patients with CRC compared to HCs, while the indoles to Trp ratio was decreased [1.34 (0.70, 2.63) vs 2.46 (1.25, 4.10), P = 0.029]. The relative ZO-1 mRNA levels in patients with CRC (0.27 ± 0.24) were significantly lower than those in HCs (1.00 ± 0.31) (P < 0.001), and the relative IDO1 mRNA levels in patients with CRC [1.65 (0.47-2.46)] were increased (P = 0.035). IDO1 mRNA levels were positively associated with the KYN/Trp ratio (r = 0.327, P = 0.003). ZO-1 mRNA and protein levels were positively correlated with the indoles/Trp ratio (P = 0.035 and P = 0.009, respectively). In addition, the genera Asaccharobacter (Actinobacteria) and Parabacteroides (Bacteroidetes), and members of the phylum Firmicutes (Clostridium XlVb, Fusicatenibacter, Anaerofilum, and Anaerostipes) decreased in CRC and exhibited a positive correlation with indoles in all subjects.CONCLUSIONAlteration of fecal Trp metabolism mediated by microbiota is associated with intestinal barrier function and tissue Trp metabolism, and may be involved in the pathogenesis of CRC.     

Liquid Crystalline Network Composites Reinforced by Silica Nanoparticles

Liquid crystalline networks (LCNs) are a class of polymers, which are able to produce mechanical actuation in response to external stimuli. Recent creation of LCNs with exchangeable links (xLCNs) makes LCNs easy moldable. As the xLCNs need to be shaped at a high temperature, it is important to enhance their thermal and mechanical properties. In this paper, a series of xLCNs/SiO₂ composites containing 1%–7% SiO₂ nanoparitcles (SNP) were prepared and their thermal and mechanical properties were examined. The results show that xLCNs/SNP composites have lower liquid crystalline-isotropic phase transition temperature and higher decomposition temperature than pure LCN. The tensile strength and the elongation at break of xLCNs at high temperatures were also enhanced due to the addition of SNPs.     

围术期护理在急性膝关节损伤关节镜手术中的应用价值体会

目的:观察并讨论在急性膝关节损伤关节镜手术中实施围术期护理的应用价值.方法:选取本院2017年10月-2018年10月期间收治的急性膝关节损伤患者114例,随机分为观察组和对照组各57例.对照组实施常规护理,观察实施围术期护理.对比2组护理效果.结果:观察组并发症总发生率、Lysholm评分、Judet膝关节屈曲度均优于对照组,对比存在差异,有统计学意义(P<0.05).结论:对急性膝关节损伤关节镜手术中采取围术期护理的效果显著,值得推广应用.