Application of lesser trochanteric reduction fixator in the treatment of unstable intertrochanteric fractures

BACKGROUND Closed reduction and internal fixation with intramedullary nails has been widely accepted for treating intertrochanteric fractures.AIM To focus on how to avoid displacement of the lesser trochanter in unstable intertrochanteric fractures.METHODS We developed a lesser trochanteric reduction fixator for treating intertrochanteric fractures through fixing the lesser trochanter by combining the loop plate through the fixator after reduction by the reducer.Five patients with intertrochanteric fractures treated with the newly developed lesser trochanteric reduction fixator and loop plate combined with intramedullary nails,and 20 patients with intertrochanteric fractures treated with simple intramedullary nails were selected from December 2020 to March 2021.RESULTS The postoperative Harris hip score was significantly higher in patients treated with the lesser trochanteric reduction fixator than in patients treated without the lesser trochanteric reduction fixator,which indicated that this lesser trochanteric reduction fixator had a positive impact on rehabilitation of the hip joint after surgery and could significantly improve the quality of life of patients.CONCLUSION We fully realize the significance of trochanteric reduction and fixation,namely,reconstruction of structures under pressure,in the treatment of intertrochanteric fractures.As long as the general condition of patients is favorable and they are willing to undergo surgery,fixation of the main fracture end should be performed and the lesser trochanter should be reduced and fixed at the same time.

右美托咪定-罗哌卡因混合液颈神经根阻滞在肩关节镜术后镇痛中的应用

目的观察右美托咪定-罗哌卡因混合液选择性颈神经根阻滞对肩关节镜手术术后镇痛效果的影响及安全性分析。方法选取厦门大学附属中山医院择期行肩关节镜手术患者60例,ASAⅠ或Ⅱ级,随机分为右美托咪定-罗哌卡因混合液组(DR组)和罗哌卡因组(R组),每组30例。两组均于术前30 min行C5、C6神经根阻滞,DR组每个神经根分别予以右美托咪定0.5μg/kg复合0.5%罗哌卡因混合液共4 ml,R组每个神经根分别予以0.5%罗哌卡因4 ml。所有患者均复合喉罩全身麻醉。记录感觉、运动阻滞起效时间及感觉、运动阻滞持续时间;记录术后不同时间点的视觉模拟评分(VAS评分);记录术后48 h纳布啡补救镇痛的用量;记录患者满意度和不良反应情况。结果 DR组感觉、运动阻滞起效时间短于R组(P <0.05);DR组感觉、运动阻滞持续时间较R组长(P<0.05);DR组术后12、18、24和36 h的VAS评分及术后48 h纳布啡用量较R组低(P<0.05);与R组比较,DR组术后满意度较高(P<0.05);DR组有2例发生心动过缓,两组呼吸困难、声音嘶哑等不良反应差异无统计学意义(P>0.05)。结论右美托咪定-罗哌卡因混合液颈神经根阻滞能明显缩短神经阻滞起效时间,延长肩关节镜手术术后镇痛时间,减少术后镇痛药物的用量,可在肩关节镜手术镇痛中安全运用。

High Conduction Band Inorganic Layers for Distinct Enhancement of Electrical Energy Storage in Polymer Nanocomposites

Dielectric polymer nanocomposites are considered as one of the most promising candidates for high-power-density electrical energy storage applications.Inorganic nanofillers with high insulation property are frequently introduced into fluoropolymer to improve its breakdown strength and energy storage capability.Normally,inorganic nanofillers are thought to introducing traps into polymer matrix to suppress leakage current.However,how these nanofillers effect the leakage current is still unclear.Meanwhile,high dopant(>5 vol%)is prerequisite for distinctly improved energy storage performance,which severely deteriorates the processing and mechanical property of polymer nanocomposites,hence brings high technical complication and cost.Herein,boron nitride nanosheet(BNNS)layers are utilized for substantially improving the electrical energy storage capability of polyvinylidene fluoride(PVDF)nanocomposite.Results reveal that the high conduction band minimum of BNNS produces energy barrier at the interface of adjacent layers,preventing the electron in PVDF from passing through inorganic layers,leading to suppressed leakage current and superior breakdown strength.Accompanied by improved Young’s modulus(from 1.2 GPa of PVDF to 1.6 GPa of nanocomposite),significantly boosted discharged energy density(14.3 J cm^(-3)) and charge-discharge efficiency(75%)are realized in multilayered nanocomposites,which are 340 and 300% of PVDF(4.2 J cm^(-3),25%).More importantly,thus remarkably boosted energy storage performance is accomplished by marginal BNNS.This work offers a new paradigm for developing dielectric nanocomposites with advanced energy storage performance.

Core-shell structured silk Fibroin/PVDF piezoelectric nanofibers for energy harvesting and self-powered sensing

The development of wearable and portable electronics calls for flexible piezoelectric materials to fabricate selfpowered devices.However,a big challenge in piezoelectric material design is to boost the output performance while ensuring its flexibility and biocompatibility.Here,all-organic and core-shell structured silk fibroin(SF)/poly(vinylidene difluoride)(PVDF)piezoelectric nanofibers(NFs)with excellent flexibility are fabricated using a simple electrospinning strategy.The strong intermolecular interaction between SF and PVDF promotes theβ-phase nucleation in the core-shell structure,which significantly enhances the output performance.An output of 16.5 V was achieved in SF/PVDF NFs,which is more than 6-fold enhancement compared with that of pure PVDF NFs.In addition,the piezoelectric device can sensitively detect the mechanical stimulation from joint bending,demonstrating its great potential in self-powered sensor.Otherwise,the piezoelectric device can be also applied to control the movement of a smart car,successfully,achieving its application in the human-machine interaction.

Transcranial sonography in differential diagnosis of Parkinson disease and other movement disorders

Background:Reports evaluating the efficacy of transcranial sonography(TCS)for the differential diagnosis of Parkinson disease(PD)and other movement disorders in China are scarce.Therefore,this study aimed to assess the application of TCS for the differential diagnosis of PD,multiple system atrophy(MSA),progressive supranuclear palsy(PSP),and essential tremor(ET)in Chinese individuals.Methods:From 2017 to 2019,500 inpatients treated at the Department of Dyskinesia,Beijing Tiantan Hospital,Capital Medical University underwent routine transcranial ultrasound examination.The cross-sections at the midbrain and thalamus levels were scanned,and the incidence rates of substantia nigra(SN)positivity and the incidence rates of lenticular hyperechoic area were recorded.The echo of the SN was manually measured.Results:Of the 500 patients,125 were excluded due to poor signal in temporal window sound transmission.Among the 375 individuals with good temporal window sound transmission,200 were diagnosed with PD,90 with ET,50 with MSA,and 35 with PSP.The incidence rates of SN positivity differed significantly among the four patient groups(χ^(2)=121.061,P<0.001).Between-group comparisons were performed,and the PD group showed a higher SN positivity rate than the ET(χ^(2)=94.898,P<0.017),MSA(χ^(2)=57.619,P<0.017),and PSP(χ^(2)=37.687,P<0.017)groups.SN positivity showed a good diagnostic value for differentiating PD from the other three movement diseases,collectively or individually.The incidences of lenticular hyperechoic area significantly differed among the four patient groups(χ^(2)=38.904,P<0.001).Next,between-group comparisons were performed.The lenticular hyperechoic area was higher in the PD group than in the ET(χ^(2)=6.714,P<0.017)and MSA(χ^(2)=18.680,P<0.017)groups but lower than that in the PSP group(χ^(2)=0.679,P>0.017).Conclusion:SN positivity could effectively differentiate PD from ET,PSP,and MSA in a Chinese population.

Dielectric Manipulated Charge Dynamics in Contact Electrification

Surface charge density has been demostrated to be sigiantly impacted by the detric properties of tibomaterals.However,the ambiguous physical mechanism of dielectric manipulated charge behavior still restricts the construction of high performance tribomaterials.Here,using the atomic force microscopy and Kelvin probe force microscopy,an in situ method was conducted to investigate the contact letrification and charge dynamics on a typical tribomaterial(ie,BaTiOj/PVDF-TrFE nanocomposite)at nanoscale.Combined with the characterization of triboelectric device at macroscale,it is found that the number of transferred electrons increases with contact force/area and tends to reach saturation under increased friction cycles.The incorporated high permittivity BaTiO,nanoparticles enhance the capacitance and electron trapping capability of the nanocomposites,eficiently inhibiting the lateral difusion of electrons and improving the output performance of the triboelectric devices.Exponential decay of the surface potential is observed over monitoring time for all dielectric samples.At high BaTiO,loadings,more electrons can drift into the bulk and combine with the induced charges on the back electrode,forming a large leakage current and accordingly accelerating the electron dissipation.Hence,the charge trapping/storing and dissipating,as well as the charge attracting properties,should be comprehensively considered in the design of high-performance tribomateras.