Natural nerve tissue is composed of nerve bundles with multiple aligned assembles, and matrix electroconductivity is beneficial to the transmission of intercellular electrical signals, or effectively deliver external electrical cues to cells. Herein, aiming at the biomimetic design of the extracellular matrix for neurons, we first synthesized electroconductive polypyrrole (PPy) nanoparticles with modified hydrophilicity to improve their uniformity in collagen hydrogel. Next, cell-laden collagen−PPy hybrid hydrogel microfibers with highly oriented microstructures were fabricated via a microfluidic chip. The hydrogel microfibers formed a biomimetic three-dimensional microenvironment for neurons, resulting from the native cell adhesion domains, oriented fibrous structures, and conductivity. The oriented fibrous microstructures enhanced neuron-like cells aligning with fibers' axon; the matrix conductivity improved cell extension and upregulated neuralrelated gene expression; moreover, external electrical stimulation further promoted the neuronal functional expression. This mechanism was attributed to the electroconductive matrix and its delivered electrical stimulation to cells synergistically upregulated the expression of an L-type voltage-gated calcium channel, resulting in an increase in the intracellular calcium level, which in turn promoted neurogenesis. This approach has potential in constructing the biomimetic microenvironment for neurogenesis.

BackgroundThis study aimed to explore the effect of retaining inferomedial cortical bone contact and fixation with calcar screws on the dynamic and static mechanical stability of proximal humerus fractures treated with a locking plate.MethodsTwelve Synbone prosthetic humeri (SYNBONE-AG, Switzerland) were used for a wedge osteotomy model at the proximal humerus, in four groups. In the cortex contact + screw fixation group and cortex contact group, the inferomedial cortical bone contact was retained. In the screw fixation group and control group, the inferomedial cortical bone contact was not retained. Calcar screw fixation was implemented only in the screw fixation groups. The dynamic and static mechanical stability of the models were tested with dynamic fatigue mechanics testing, quasi-static axial compression, three-point bending, and torsion testing.ResultsThe cortex contact + screw fixation group showed the longest fatigue life and the best stability. There was 35% difference in fatigue life between the cortex contact + screw fixation group and the cortex contact group, 43%between the cortex contact + screw fixation group and screw fixation group, and 63% between the cortex contact + screw fixation group and screw fixation group (P < 0.01). The cortex contact + screw fixation group showed the best axial compressive stiffness, bending stiffness, and torsion stiffness; these were successively decreased in the other three groups (P < 0.01).ConclusionRetaining inferomedial cortical bone contact and fixation with two calcar screws maintained fracture stability with the highest strength and minimum deformation. Of the two methods, restoration of the inferomedial cortical bone support showed better dynamic and static biomechanical properties than placement of calcar screws alone.

Enamine and imine represent two of the most common reaction intermediates in syntheses, and the imine intermediates containing α-hydrogen often exhibit the similar reactivity to enamines due to their rapid tautomerization to enamine tautomers. Herein, we report that the minor structural difference between the enamine and the enamine tautomer derived from imine tautomerization results in the different chemo- and regioselectivity in the reaction of cyclohexanones, amines and TEMPO: the reaction of primary amines furnishes the formal oxygen 1,2-migration product, α-amino-enones, while the reaction of secondary amines under similar conditions generates exclusively arylamines via consecutive dehydrogenation on the cyclohexyl rings. The 18O-labeling experiment for α-amino-enone formation revealed that TEMPO served as oxygen transfer reagent. Experimental and computational studies of reaction mechanisms revealed that the difference in chemo- and regioselectivity could be ascribed to the flexible imine-enamine tautomerization of the imine intermediate containing an α-hydrogen.

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Nanostructured lithium-manganese-rich nickel-manganese-oxide xLi 2 MnO 3 Á(1-x)LiNi 0.5 Mn 0.5 O 2 (0.3 x 0.6) composite materials were synthesized via spray pyrolysis using mixed nitrate precursors. All the materials showed a composite structure consisting of Li 2 MnO 3 (C2/m) and LiNi 0.5 Mn 0.5 O 2 ðR3mÞ components, and the amount of Li 2 MnO 3 -phase appeared to increase with x, as observed from XRD analysis. These composite materials showed a high-discharge capacity of about 250 mAhg 21 . In the range of x considered, the layered 0.5Li 2 MnO 3 Á0.5LiNi 0.5 Mn 0.5 O 2 materials displayed the highest capacity and superior cycle stability. Nonetheless, voltage suppression from a layered-spinel phase transition was observed for all the composites produced. This voltage suppression was dependent of the amount of Li 2 MnO 3 phase present in the composite structure. V C 2013 American Institute of Chemical Engineers AIChE J, 60: 443-450, 2014 Keywords: Li-Mn-rich cathode, xLi 2 MnO 3 Á(1-x)LiNi 0.5 Mn 0.5 O 2 , spray pyrolysis, high-energy, Li-ion battery

OBJECTIVES Our goal was to assess the influence of working hours and working at night on intraoperative complications on surgeons conducting video-assisted pulmonary resections. METHODS We identified all patients who underwent video-assisted thoracoscopic surgery (VATS) in Shanghai Chest Hospital from January 2015 to April 2017. Univariable and multivariable logistic analyses were used to analyse independent risk factors for intraoperative complications. A 1:4 propensity score matching analysis was conducted to verify those results. RESULTS A total of 15 767 patients who underwent VATS pulmonary resection were included in this study. Among them, 15 280 patients (96.1%) were operated on during daytime working hours and 487 (3.1%) at night. A total of 203 (1.3%) intraoperative complications occurred. Vascular injury was the main cause of intraoperative complications, accounting for 92.1% (187/203). Multivariable logistic regression indicated that age [odds ratio (OR) = 1.68, 95% confidence interval (CI) 1.43–1.98; P < 0.001], gender (OR = 1.71, 95% CI 1.26–2.32; P = 0.001), surgical experience (OR = 2.07, 95% CI 1.56–2.75; P < 0.001), type of surgery (OR = 0.31, 95% CI 0.20–0.49; P < 0.001) and operative periods (OR = 2.69, 95% CI 1.61–4.86; P < 0.001) were independent predictors for intraoperative complications. The incidence of intraoperative complications during night-time surgery was significantly higher than that during daytime working hours. A 1:4 propensity score matching-based results verification showed that night-time surgery was still an independent risk factor after propensity score matching (OR = 2.76, 95% CI 1.47–5.15; P = 0.002). CONCLUSIONS The incidence of intraoperative complications from VATS pulmonary resection performed during night hours was significantly higher than that performed during working hours. In the present labour environment, thoracic surgeons should avoid night-time surgery whenever possible.