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.     

A Murine Rp1 Missense Mutation Causes Protein Mislocalization and Slowly Progressive Photoreceptor Degeneration

Mutations in the RP1 gene can cause retinitis pigmentosa. We identified a spontaneous L66P mutation caused by two adjacent point mutations in the Rp1 gene in a colony of C57BL/6J mice. Mice homozygous for the L66P mutation exhibited slow, progressive photoreceptor degeneration throughout their lifespan. Optical coherence tomography imaging found abnormal photoreceptor reflectivity at 1 month of age. Histology found shortening and disorganization of the photoreceptor inner and outer segments and progressive thinning of the outer nuclear layer. Electroretinogram a- and b-wave amplitudes were decreased with age. Western blot analysis found that the quantity and size of the mutated retinitis pigmentosa 1 (RP1) protein were normal. However, immunohistochemistry found that the mutant Rp1 protein partially mislocalized to the transition zone of the shortened axonemes. This mutation disrupted colocalization with cytoplasmic microtubules in vitro. In conclusion, the L66P mutation in the first doublecortin domain of the Rp1 gene impairs Rp1 protein localization and function, leading to abnormalities in photoreceptor outer segment structure and progressive photoreceptor degeneration. This is the first missense mutation in Rp1 shown to cause retinal degeneration. It provides a unique, slowly progressive photoreceptor degeneration model that mirrors the slow degeneration kinetics in most patients with retinitis pigmentosa.As the most common inherited form of blindness, retinitis pigmentosa (RP) affects >100,000 persons in the United States and 1.5 million worldwide.¹ Clinically, it is characterized by night blindness, progressive loss of peripheral vision, and bone spicule-shaped pigmentary retinopathy. Mutations in the RP1 gene are a common cause of autosomal dominant RP and a less common cause of autosomal recessive RP.^2–5 Most pathological mutations in RP1 are either nonsense or frameshift mutations and are located at the beginning of exon 4 of the RP1 gene. A few missense variants in RP1, such as T373I,⁶ A669T,⁶ K663N,⁷ L1808P,⁷ D984G,⁸ R1652L,⁹ and K1370E,⁹ have been reported in patients with RP, but it is unclear whether they are disease-causing mutations.The RP1 gene located on chromosome 8q12 consists of four exons with an open reading frame of 6468 bp, which is primarily contained within exon 4 (788 to 6468 bp), and it encodes a predicted protein of 2156 amino acids. It has been determined by Northern blot analysis^3,10,11 and in situ hybridization³ that RP1 is expressed exclusively in rod and cone photoreceptor cells of the retina. In mice, retinitis pigmentosa 1 (Rp1) is localized to the axoneme of both rod and cone photoreceptors.¹² Targeted disruption of the Rp1 gene in mice results in disorganization of outer segments (OS) with progressive degeneration of photoreceptors.¹³ Further studies reported that Rp1 plays a role in controlling the orientation and organization of disks in the OS.¹⁴ The photoreceptor axoneme begins at the basal body in the inner segment (IS), passes through the transition zone between the IS and OS, and continues into the OS.¹⁵ It was suggested that the axoneme has a role in stabilizing the stack of disk membranes.¹⁵The N-terminus of RP1 shares significant homology with the protein doublecortin (DCX), whose mutation is associated with cerebral cortical abnormalities.^16,17 This domain binds microtubules and promotes their assembly.¹⁸ Our data show that the homozygous L66P substitution in the first DCX domain of the Rp1 gene alters axoneme binding and causes axoneme shortening, disorganization of OS, and slowly progressive photoreceptor death.     

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。