Plant-inspired multifunctional fluorescent cellulose nanocrystals intelligent nanocomposite hydrogel.

Intelligent hydrogel has great application potentials in flexible sensing and artificial intelligence devices due to its intrinsic characteristics. However, developing an intelligent hydrogel with favorable properties including high strength, superior toughness, excellent conductivity and ionic sensing via a facile route is still a challenge. Herein, inspired by biologically chelating interactions of phytic acid (PA) in plants, a plant-inspired versatile intelligent nanocomposite hydrogel was readily fabricated by incorporating PA into the interface of fluorescent cellulose nanocrystals (F-CNC). Under PA "molecular bridge", the hydrogel simultaneously realized superflexibility (1000 %), high strength, superb self-healing ability, remarkable fluorescence and chloride ion sensibility as well as good ionic conductivity (2.4 S/m). The hydrogel could be assembled as a flexible sensor for real-time monitoring of human motion with excellent sensitivity and stability since high sensitivity toward both strain and pressure. F-CNC acted as a functional trigger could confer the hydrogel good fluorescence and high sensitivity toward chloride ion. This design confirms the synergy of F-CNC in boosting strength, ionic sensing, and ionic conductivity, addressing a long-standing dilemma among strength, stretchability, and sensitivity for intelligent hydrogel. The one-step incorporating tactic under mild ambient conditions may open an innovative avenue for the construction of intelligent hydrogel with novel properties.

Macrophage migration inhibitory factor takes part in the lumbar ligamentum flavum hypertrophy.

The present study aimed to observe the content difference of macrophage migration inhibitory factor [MIF; novoprotein recombinant human MIF (n­6his) (ch33)], TGFß1 and MMP13 in patients with and without ligamentum flavum (LF) hypertrophy and investigate the roles of MIF in LF hypertrophy. The concentration of MIF, TGFß1 and MMP13 in LF were detected by ELISA in a lumbar spinal stenosis (LSS) group and a lumbar disc herniation (LDH) group. Culture of primary LFs and identification were performed for the subsequent study. Cell treatments and cell proliferation assay by CCK­8 was performed. Western blot and quantitative PCR analysis were used to detect the expression of TGFß1, MMP13, type I collagen (COL­1) and type III collagen (COL­3) and Src which were promoted by MIF. The concentration of MIF, TGFß1 and MMP13 were higher in the LSS group compared with the LDH group. Culture of primary LFs and identification were performed. Significant difference in LFs proliferation occurred with treatment by MIF at a concentration of 40 nM for 48 h (P<0.05). The gene and protein expression of TGFß1, MMP13, COL­1, COL­3 and Src were promoted by MIF (P<0.05). Proliferation of LFs was induced by MIF and MIF­induced proliferation of LFs was inhibited by PP1 (a Src inhibitor). MIF may promote the proliferation of LFs through the Src kinase signaling pathway and can promote extracellular matrix changes by its pro­inflammatory effect. MIF and its mediated inflammatory reaction are driving factors of LF hypertrophy.

One-Pot Synthesis of UPy-Functionalized Nanocellulose under Mechanochemical Synergy for High-Performance Epoxy Nanocomposites.

The high strength, high specific surface area, excellent biocompatibility, and degradability of nanocellulose (NCC) make it a potential reinforcing phase for composite materials. However, the polyhydroxyl property of NCC renders it prone to self-aggregation and it has weak interfacial compatibility with non-polar substrates, limiting its enhancement performance for composite materials. Therefore, based on the high reactivity of NCC, the chemical modification of NCC to introduce functional groups is the basis for effectively reducing its self-aggregation, improving its interfacial compatibility with the polymer matrix, and creating nanocellulose-based functional materials. The existing functional modifications of NCC have limitations; they require cumbersome steps, generate low yields, and are environmentally unfriendly. Herein, ureido-pyrimidinone (UPy) was introduced to NCC through a sustainable and high-efficiency avenue formed by the mechanochemical synergy of microwaves and ultrasonication. The obtained UPy-modified nanocellulose (NCC-UPy) exhibited a rod-like shape, with a length of 200−300 nm and a width of 20−30 nm, which presented oriented and stable dispersion in an aqueous medium, and the zeta potential reached −40 mV. Moreover, NCC-UPy had good thermostability (>350 °C) and high crystallinity (82.5%) within the crystal type of cellulose I. Using the as-prepared NCC-UPy as a molecular bridge, it was organically combined with epoxy resin through multiple hydrogen bonds to construct a nanocomposite membrane with superior mechanical strength and thermal stability. The results revealed that NCC-UPy dispersed uniformly in the epoxy matrix without aggregating and that the interfacial compatibility was good, leading to an 87% increase in the tensile strength of the formed nanocomposite membrane when 0.5 wt.% NCC-UPy was loaded. It was proved that NCC-UPy had remarkable reinforcing potential and effective stress transfer capacity for composites. Consequently, this study may open the door to the development of a one-pot green approach for undertaking the functional modification of NCC, and it is of great significance for the development of NCC-based nanocomposites.

One-pot synthesis of aminated cellulose nanofibers by "biological grinding" for enhanced thermal conductivity nanocomposites.

Aminated cellulose nanofibers (A-CNF) with high thermostability (>350 ℃), high crystallinity (81.25 %), and high dispersion stability were extracted from "biological grinding" biomass through one-pot microwave-hydrothermal synthesis. Worm-eaten wood powder (WWP) as the product of "biological grinding" by borers is a desirable lignocellulose for fabricating A-CNF in a green and cost-effective way since it is a well-milled fine powder with dimension of dozens of microns, which can be used directly, saving energy and labor. Generated A-CNF proved to be an excellent reinforcing and curing agent for constructing high performance epoxy nanocomposites. The nanocomposites exhibited a thermal conductivity enhancement of about 120 %, coefficient of thermal expansion reduction of 78 %, and Young's modulus increase of 108 % at a low A-CNF loading of 1 wt.%, demonstrating their remarkable reinforcing potential and effective stress transfer behavior. The process proposed herein might help to bridge a closed-loop carbon cycle in the whole production-utilization of biomass.

[Treatment of old acetabular posterior wall fracture with 3D printing combined with composite plate internal fixation].

OBJECTIVE: To explore the application value and clinical effect of three-dimensional printing combined with composite plate internal fixation in the treatment of old acetabular posterior wall fracture. METHODS: From May 2010 to October 2016, Mimics 19.0 software was used to plan preoperatively according to a 1:1 print pelvic 3D model. At the same time, 23 patients with old acetabular posterior wall fractures were treated with combined plate internal fixation, including 15 males and 8 females, aged 20 to 63 (43.0±5.1) years old, and the time from injury to operation was 23 to 101(47.0±10.5) days. According to Letournel-Judet classification, 11 cases were posterior wall fracture, 7 cases were transverse with posterior wall fracture, and 5 cases were posterior column with posterior wall fracture. All patients were treated with single Kocher-Langenbeck approach combined plate internal fixation, and the evaluation indexes were recorded during operation, after operation and during follow-up. RESULTS: The operation time of 23 patients was (113.5±11.5) min, bleeding was (550.0±104.7) ml and fluoroscopy was (12.7±0.8) s. Matta radiographic reduction criteria were used: excellent in 14 cases, good in 7 cases and poor in 2 cases; 23 patients were followed up for 10 to 24 (16.0±5.6) months. The hip function was evaluated according to the modified Merle d'Aubingne and Postal scoring system at the last follow-up: excellent in 11 cases, good in 8 cases, fair in 3 cases and poor in 1 case. There were 3 cases of traumatic arthritis, 1 case of femoral head necrosis, 2 cases of heterotopic ossification and 5 cases of sciatic nerve irritation. CONCLUSIONS: 3D printing technique is an effective and fast method for the treatment of old acetabular posterior wall fractures. In addition, the printing model can provide three-dimensional morphological structure for the operator, combined with preoperative simulation, facilitate intraoperative reduction, and effectively improve the efficiency of surgery.

Comparison of Efficacy between 3D Navigation-Assisted Percutaneous Iliosacral Screw and Minimally Invasive Reconstruction Plate in Treating Sacroiliac Complex Injury.

The clinical efficacy was compared between 3D navigation-assisted percutaneous iliosacral screw (3DPS) and minimally invasive reconstruction plate (MIRP) in treating sacroiliac complex injury and the surgical procedures of 3DPS were introduced. A retrospective analysis was performed on 49 patients with sacroiliac complex injury from March 2013 to May 2017. Twenty-one cases were treated by 3DPS, and 28 cases by MIRP. Intraoperative indexes as operative time, blood loss, incision length, length of hospital stay and postoperative complications were respectively documented. Quality of reduction was postoperatively evaluated by Matta radiological criteria, and clinical effect was assessed by Majeed scoring criteria at the last follow-up. Operative time and hospital stay were significantly shortened, and blood loss, and incision length were significantly reduced in 3DPS group as compared with those in MIRP group (P<0.05). No statistically significant difference was found between 3DPS group and MIRP group in the assessment of reduction and function (P>0.05). It was concluded that both 3DPS and MIRP can effectively treat the sacroiliac complex injury, and 3DPS can provide an accurate, safe and minimally invasive fixation with shorter operative time and hospital stay.

[Determination of benzoyl peroxide in wheat flour by high performance liquid chromatography].

An improved method for the determination of benzoyl peroxide in wheat flour is reported. Benzoyl peroxide was extracted with petroleum ether, and then analysed by reversed-phase high performance liquid chromatography on a Shim-Pack VP-ODS column (0.46 cm i.d. x 15 cm, 5 microm - 6 microm) using a mobile phase of acetonitrile-0.3% H3PO4 aqueous solution (4:1 in volume ratio) with a flow rate of 1.0 mL/min, and UV-236 nm detection. A linear correlation was observed between 0.002 g/L- 0.012 g/L of benzoyl peroxide. The detection limit was 0.005 g/kg. This proposed method without redox reaction is superior to colorimetric determination. This method is characterized with simplicity, convenience, reproducibility and accuracy.