[Orthopaedic robot assisted closed reduction and cannulated screw internal fixation for the treatment of femoral neck fractures].

OBJECTIVE: To investigate the preliminary clinical effect of closed reduction and cannulated nail internal fixation for femoral neck fracture assisted by robot navigation and positioning system. METHODS: From July 2019 to January 2020, 16 cases of femoral neck fracture （navigation group） were treated with closed reduction and internal fixation guided by robot system, including 7 males and 9 females, aged 25 to 72 years old with an average of （53.61±5.45） years old；Garden classification of fracture：3 cases of typeⅠ, 3 cases of typeⅡ, 8 cases of type Ⅲ, 2 cases of type Ⅳ. Non navigation group （control group）：20 cases of femoral neck fracture were treated with closed reduction and hollow nail internal fixation, 8 males and 12 females, aged 46 to 70 years old with an average of （55.23±4.64） years old；Garden typeⅠin 2 cases, typeⅡin 4 cases, type Ⅲ in 11 cases, type Ⅳ in 3 cases. The operation time, fluoroscopy times, guide needle drilling times, screw adjustment times, intraoperative bleeding volume and other indicators of two groups were evaluated. RESULTS: Both groups were followed up for 12 to 18 months with an average of （15.6±2.8） months. The fractures of both groups were healed without delayed union and nonunion. There was no significant difference in healing time between two groups（P=0.782）. There was no significant difference in Harris scores between two groups at the last follow-up（P=0.813）. There was no significant difference in operation time between two groups（P>0.05）. There were significant differences between two groups in fluoroscopy times, guide needle drilling times, hollow screw replacement times, and intraoperative bleeding volume（P<0.05）. CONCLUSION: Closed reduction and hollow screw internal fixation assisted by robot navigation system for femoral neck fracture has the advantages of minimally invasive operation, precise screw placement, and reduction of X-ray radiation damage during operation.

Mechanism-based ligand design for copper-catalysed enantioconvergent C(sp3)-C(sp) cross-coupling of tertiary electrophiles with alkynes.

In contrast with the well-established enantioconvergent radical C(sp3)-C cross-coupling of racemic secondary alkyl electrophiles, the corresponding coupling of tertiary electrophiles to forge all-carbon quaternary stereocentres remains underexplored. The major challenge arises from the steric hindrance and the difficult enantio-differentiation of three distinct carbon substituents of prochiral tertiary radicals. Here we demonstrate a general copper-catalysed enantioconvergent C(sp3)-C(sp) cross-coupling of diverse racemic tertiary alkyl halides with terminal alkynes (87 examples). Key to the success is the rational design of chiral anionic N,N,N-ligands tailor-made for the computationally predicted outer-sphere radical group transfer pathway. This protocol provides a practical platform for the construction of chiral C(sp3)-C(sp/sp2/sp3) bonds, allowing for expedient access to an array of synthetically challenging quaternary carbon building blocks of interest in organic synthesis and related areas.

Copper-Catalyzed anti-Selective Radical 1,2-Alkylarylation of Terminal Alkynes.

A copper-catalyzed highly anti-selective radical 1,2-alkylarylation of terminal alkynes with aryl boronic acids and alkyl bromides has been established. The reaction exhibits high compatibility with a wide range of terminal alkynes and diverse aryl boronic acids, thus providing facile access to various stereodefined trisubstituted alkenes in high yield under mild reaction conditions. Preliminary mechanistic investigations support the formation of alkyl radicals and their subsequent addition to alkynes in the reaction.

A novel self-assembled nano micelle as a highly efficient artificial peroxidase based on hexadecyl trimethyl ammonium bromide and cytochrome c.

A novel artificial peroxidase (AP) with highly catalytic efficiency was designed using hexadecyl trimethyl ammonium bromide (CTAB, 3 mM) nano-micelles and bovine heart cytochrome c (Cyt c, 0.5 µM) in 100 mM, pH 8.0 phosphate buffer at 25°C. The catalytic rate (kcat) and Michaelis-Menten (Km) of the AP were determined to be 0.311 ± 0.013 s(-1) and 8.64 ± 0.6 µM. The catalytic efficiency was 0.0360 ± 0.0020 µM(-1)s(-1) (about 50% the efficiency of native horseradish peroxidase). The Ultraviolet-visible spectrophotometer and Circular Dichroism techniques were applied to study the properties of the CTAB-Cyt c nano-micelle. Designed AP can be applied instead of native horseradish peroxidase.

Glucose biosensing using glassy carbon electrode modified with polyhydroxy-C60, glucose oxidase and ionic-liquid.

Direct electrochemistry of glucose oxidase (GOD) was achieved when an ionic liquid/GOD-Polyhydroxy-C60 functional membrane was confined on a glassy carbon electrode (GCE). The cyclic voltammograms (CVs) of the modified GCE showed a pair of redox peaks with a formal potential (E°') of - 329 ± 2 mV. The heterogeneous electron transfer constant (k(s)) was 1.43 s-1. The modified GCE response to glucose was linear in the range from 0.02 to 2.0 mM. The detection limit was 1 µM. The apparent Michaelis-Menten constant (K(m)(app)) was 1.45 mM.

Direct electrochemistry of glucose oxidase and glucose biosensing on a hydroxyl fullerenes modified glassy carbon electrode.

Direct electrochemistry of glucose oxidase (GOD) was achieved when GOD-hydroxyl fullerenes (HFs) nano-complex was immobilized on a glassy carbon (GC) electrode and protected with a chitosan (Chit) membrane. The ultraviolet-visible absorption spectrometry (UV-vis), transmission electron microscopy (TEM), and circular dichroism spectropolarimeter (CD) methods were utilized for additional characterization of the GOD, GOD-HFs and Chit/GOD-HFs. Chit/HFs may preserve the secondary structure and catalytic properties of GOD. The cyclic voltammograms (CVs) of the modified GC electrode showed a pair of well-defined quasi-reversible redox peaks with the formal potential (E°') of 353 ± 2 mV versus Ag/AgCl at a scan rate of 0.05 V/s. The heterogeneous electron transfer constant (ks) was calculated to be 2.7 ± 0.2s(-1). The modified electrode response to glucose was linear in the concentrations ranging from 0.05 to 1.0mM, with a detection limit of 5 ± 1 µM. The apparent Michaelis-Menten constant (Km(app)) was 694 ± 8 µM. Thus, the modified electrode could be applied as a third generation biosensor for glucose with high sensitivity, selectivity and low detection limit.