Successful reconstruction of an ankle defect with free tissue transfer in a hemophilia A patient with repetitive hemoarthrosis:A case report

BACKGROUND Hemophilia, an uncommon yet consequential hereditary bleeding disorder, manifests as two clinically indistinguishable forms that hinder the normal functioning of the coagulation cascade. This impairment renders individuals more susceptible to excessive bleeding during significant surgical interventions. Moreover, individuals with severe hemophilia frequently encounter recurring hemarthrosis, resulting in progressive joint destruction and, subsequently, the need for hip and knee replacement surgeries.CASE SUMMARY The patient was a 53-year-old man with hemophilia A as the underlying disease and had self-injected factor Ⅷ twice weekly for several decades. He had undergone ankle fusion surgery for recurrent hemarthrosis at the Department of Orthopedic Surgery 1 mo prior and was referred to our department because of skin necrosis after a hematoma at the surgical site. An anterolateral thigh perforator free flap was created after three cycles of factor Ⅷ administration in addition to the concomitant administration of tranexamic acid(TXA)(Transamin 250 mg cap, 1 cap tid, q8h). After the operation, from postoperative days(PODs) 1-5, the factor Ⅷ dose and interval were maintained, and q12h administration was tapered to q24h administration after POD 6. Because the patient’s flap was stable 12 d after the operation, factor Ⅷ administration was tapered to twice a week. At 6 mo follow-up, the patient recovered well without any complications.CONCLUSION To the best of our knowledge, there are very few reports of successful free flaps in patients with hemophilia, and none have been reported in patients with hemophilia A. Moreover, there are several reports on the efficacy of TXA in free flaps in general patients;however, there are no case reports of combining factor Ⅷ and TXA in patients with hemophilia. Therefore, we report this case to contribute to future academic research.

MHD flow and heat transfer from continuous surface in uniform free stream of non-Newtonian fluid

An analysis is carried out to study the steady flow and heat transfer characteristics from a continuous flat surface moving in a parallel free stream of an electrically conducting non-Newtonian viscoelastic fluid. The flow is subjected to a transverse uniform magnetic field. The constitutive equation of the fluid is modeled by that for a second grade fluid. Numerical results are obtained for the distribution of velocity and temperature profiles. The effects of various physical parameters like viscoelastic parameter, magnetic parameter and Prandtl number on various momentum and heat transfer characteristics are discussed in detail and shown graphically.

SYNTHESIS OF HETEROARM STAR-SHAPED POLYMER BY THE USE OF POLYFUNCTIONAL CHAIN-TRANSFER AGENT via CONVENTIONAL FREE RADICAL POLYMERIZATION

Heteroarm star-shaped polymers were synthesized by conventional free radical polymerization in two steps by the use of polyfunctional chain transfer agent.In the first step,free radical polymerization of methyl methacrylate was carried out in the presence of a polyfunctional chain transfer agent,pentaerythritol tetrakis(3-mercaptopropinate).At appropriate monomer conversions,two-arm PMMA having two residual thiol groups at the chain center or three-arm PMMA having one residual thiol group at the core were o...

Zero-Magnetic-Field Oscillation of Spin Transfer Nano-Oscillator with a Second-Order-Perpendicular-Anisotropy Free Layer

The zero-magnetic-field oscillation behavior of spin torque nano-oscillator （STNO） with a perpendicularly mag- netized free layer with second-order uniaxial anisotropy is studied theoretically based on the Landau-Lifshitz- Cilbert-Slonczewski equation. It is demonstrated numerically that the second-order uniaxial anisotropy plays a significant role in the occurrence of a zero-magnetic-field steady-state precession, which can be understood in terms of the energy balance between the energy accumulation due to the spin torque and the energy dissipation due to the Gilbert damping. In particular, a relatively large zero-magnetic-field-oscillation current region, in which the corresponding microwave frequency is increased while the threshold current still maintains an almost constant value, can be obtained by modulating the second-order uniaxial anisotropy of the free layer. These results suggest a tunable zero-magnetic-field STNO, and it may be a promising configuration for STNO＇s applications in future wireless communications.

Nonequilibrium Solvent Free Energy Curve from Molecular Theory in Electron Transfer Reaction

The microscopic moleeular theory for electron transfer in a model solvent ishahr developed. The nonlinear response of the solvent molecules is be computedquanitatively in a new way. Adopting computer simulation daa and choosingappropriate reaction coordinae, a reasonable free energy dinram is constructed and thercorganhaion energy for the product state is calculated.

PHOTOCATALYTIG DECOMPOSITION OF METHANOL BY VC1_2 AND TRANSFER OF HYDROGEN AND METHYL FREE RADICALS

The photocatalytic decomposition of methanol in the presence of vanadium dichloride and the transfer of hydrogen and methyl free radicals to the additives and dinitrogen were reported.

Heat transfer of liquid metal alloy on copper plate deposited with film of different surface free energy

Liquid metal alloys(LMAs) are the potential candidates of thermal interface materials(TIMs) for electronics cooling.In the present work, buffer layers of Ag, Ti, Cu, Ni, Mo, and W were deposited on polished Cu plates by DC magnetron sputtering, the contact angles of de-ionized water and diiodomethane on the buffer layers were measured by an easy drop shape analyzer and the surface free energies(SFEs) of the buffer layers were calculated by the Owens–Wendt–Kaelble equation. Samples were prepared by sandwiching the filmed Cu plates and LMAs. The thermal properties of the samples were measured by laser flash analysis method. The SFE of the buffer layer has a strong influence on the interface heat transfer, whereas the measurement temperature has no obvious effect on the thermal properties of the samples. As the SFE of the buffer layer increases, the wettability, thermal diffusivity, and thermal conductivity are enhanced, and the thermal contact resistance is decreased.

Modeling of unsteady MHD free convection flow with radiative heat transfer in a rotating fluid

In this paper, a numerical simulation has been carried out on unsteady hydromagnetic free convection near a moving infinite flat plate in a rotating medium. The temperatures involved are assumed to be very high so that the radiative heat transfer is significant, which renders the problem highly non-linear even with the assumption of a differential approximation for the radiative heat flux. A numerical method based on the Nakamura scheme has been employed to obtain the temperature and velocity distributions which are depicted graphically. The effects of the different parameters entering into the problem have been discussed extensively.

水液相下Eda酮式异构体与超氧化氢自由基反应的DFT理论计算

在M06-2X/SMD/6-311+G(d,p)理论水平下,研究水液相1个大气压、 310.15 K温度下依达拉奉(Eda)酮式异构体与超氧化氢自由基(·HO_(2))的反应机理.结果表明:Eda酮式异构体与·HO_(2)的反应有抽H、加成和单电子转移3个过程;抽H反应主要通过·HO_(2)抽取杂环H和甲基H实现,反应的自由能垒为77.1~78.7 kJ/mol;加成反应可通过·HO_(2)加成不饱和C的过程实现,加成自由能垒为48.2~95.0 kJ/mol;加成到杂环上与甲基相连的C原子的放热反应最具优势,自由能垒为48.2 kJ/mol;单电子转移的自由能垒为141.1 kJ/mol,该过程不能实现.可见,水液相下Eda酮式异构体可通过抽H和加成反应消除·HO_(2).

基于SWIPT的无小区大规模MIMO-NOMA系统能量效率研究

无小区大规模多输入多输出(Multiple-Input Multiple-Output,MIMO)与非正交多址接入(Non-Orthogonal Multiple Access,NOMA)都是未来6G的使能技术。无线携能通信(Simultaneous Wireless Information and Power Transfer,SWIPT)技术在进行信息解码的同时收集能量,与无小区大规模MIMO-NOMA优势互补。文中基于SWIPT研究无小区大规模MIMO-NOMA系统中的能量效率问题,通过联合优化功率分配系数和SWIPT的时隙切换(Time Switching,TS)系数,提高系统的能量效率。为了最大化能量效率,采用布谷鸟算法设计功率分配系数。考虑一种特殊情况,将所有终端的TS系数设置相同,进而推导了最佳TS系数的封闭表达式。仿真结果表明,相较于几种已有方案,文中提出的优化方案可以显著提升系统的能量效率。

基于多绕组变压器的高压无线充电自由定位系统

针对电动车辆无线电能传输(wireless power transfer,WPT)系统存在的半导体性能有限和定位困难的问题,提出了一种多对一高压无线充电自由定位系统。该系统采用逆变器串联输入的设计来适应高压应用场景,同时利用多绕组变压器实现逆变器的等效并联输出和向多路发射回路传输电能的功能,并采用了多对一的设计以扩大电动车的定位范围以实现无线充电的自由定位功能。为分析多绕组变压器的工作机理和研究多对一拓扑的能量传输特性,进行了等效电路分析和MATLAB仿真,并制作实验室原型样机进行了实验验证。基于实验和仿真结果,提出了一种基于多对一WPT拓扑的混合工作模式,可以有效地扩大电动车辆无线充电时的定位范围。研究和分析表明,文中所提出的拓扑结构可以有效地提高系统的输入电压以应用于高压场景,并能有效扩大电动车辆无线充电时的定位范围以实现自由定位。

金属催化辅助无转移石墨烯薄膜制备技术研究进展

作为一种原子级别厚度的二维碳材料,石墨烯已经被证明具有优异的电学、光学、热学等综合物化性能。但是如何制备高质量、大面积晶圆级别的石墨烯薄膜仍然是激发人们进行科学研究以及器件集成领域的一大热点问题。传统过渡金属催化合成石墨烯薄膜的化学气相沉积工艺往往需要复杂费时的后处理转移工序,会对石墨烯薄膜本征性能造成巨大破坏,因此研究如何在介电基底上直接制备高质量大面积的石墨烯薄膜具有重大意义。基于此目的而兴起的无转移石墨烯薄膜制备研究已经取得了显著的科学成就,其中金属催化辅助合成无转移石墨烯薄膜的研究尤其引人注目,并且基于原位合成石墨烯薄膜性能测试及器件验证均取得了不错的效果。尽管如此,由于催化剂种类、形态以及结构设计等因素的不同,针对金属催化剂在无转移石墨烯薄膜合成过程中的工艺策略,不同的研究有不同的设计。本文基于无转移石墨烯薄膜制备的最新研究结果,对金属在催化转化获得无转移石墨烯过程中的作用机理和设计策略进行了系统全面的分析,对促进高质量晶圆级石墨烯薄膜的合成及在电子、光电子等功能器件领域的应用具有重要的指导意义。

半自由声场下车辆开闭件的时频优化

乘用车关门工况下半自由声场测量需要在整车制造完成之后才能进行,因此对关门声辐射的提前预测与优化分析显得至关重要。首先,通过设计整车试验和台架试验获取加速度振动响应和频率响应函数,实现关门工况下瞬态冲击载荷的离散化,进一步联合传递路径分析(TPA)与连续小波变换(CWT)提出TPA-CWT方法进行离散化瞬态冲击载荷时频分析。其次,根据关门工况下车门的动力学特性,将求取的离散化瞬态冲击载荷输入至已建立的车门有限元模型中,进而将车门有限元瞬态加速度振动响应映射至车身时域边界元模型预测半自由声场辐射噪声,并与整车试验中麦克风处的实测结果进行对比,声压曲线整体趋势与局部峰值的一致性证明了时域边界元仿真可以精准捕捉到关门工况下瞬态声压特性;最后,通过等效辐射声功率选取低频噪声贡献量前3的部件作为设计变量,再利用多目标粒子群优化对车门质量与关门声辐射进行优化,优化后车门质量减小1.8%,关门声辐射减小1.7%,达到了多目标优化的目的。结果表明,仿真数据与试验结果一致性较好,验证了通过将车门关闭瞬态载荷离散化处理方式和声固耦合分析在关门工况下多目标优化中的可行性,并为后续改款车型的车门设计提供一定的指导方向。

一种基于无转移PMMA和PI的渗透性标准漏孔的氦气渗透性能研究

研制了一种基于无转移聚甲基丙烯酸甲酯(PMMA)或聚酰亚胺(PI)的漏孔元件。通过在铜箔上旋涂PMMA或PI,另一面旋涂光刻胶,并利用紫外光刻打孔,在铜箔上刻蚀出了不同阵列的直径约10μm的小孔。基于差压法测量了氦气通过该标准漏孔元件的流导。结果表明:在从5 kPa到105 Pa压力范围内,各测试样品均表现出分子流动状态;无转移PMMA或PI的流导和有效渗透面积呈线性关系,可通过控制小孔数量来控制PMMA或PI的有效渗透面积,从而获得不同的流导;所开发的无转移PMMA或PI为优良的低渗透漏孔理想材料。

基于光诱导电子转移的比率型发光传感器定量检测生物样本中的多巴胺

长余辉发光材料是一种光致发光材料,在激发停止后以光的形式将储存的能量缓慢释放出来,因其优异的光学性能而在生物传感和生物成像领域得到广泛应用.本文将发光性能优异的双发射长余辉纳米粒子Sr_(2.992)Mg_(0.9)Si_(2)O_(8)∶0.008Eu^(2+),0.10Mn^(2+)(SEM)和酪氨酸酶(Tyrosinase,TYR)共价偶联,开发了一种比率型发光传感器(SEM-TYR),其可避免自发荧光干扰和外部干扰,可用于高灵敏、高选择性检测生物样本中的多巴胺(DA).当DA存在时,酪氨酸酶将其氧化生成多巴醌,依据光诱导电子转移(PET)原理,SEM-TYR光致激发的电子部分转移至电子受体多巴醌,导致SEM-TYR中680 nm红色余辉猝灭.在最优实验条件下,双发射余辉猝灭比值Δ(I680/I460)与DA浓度呈良好的线性关系,线性范围为0.2~10μmol/L(R^(2)=0.9965),检出限为40 nmol/L.将该方法用于生物样本血清、尿液及汗液中DA的检测,回收率分别为94.8%~104.0%,91.3%~101.6%和97.4%~105.2%,RSD<6.8%(n=10).所开发的比率型发光传感器用于生物样本中DA的检测具有潜在的应用前景.

粤港澳大湾区轨道交通票务清分系统互联互通及一体化方案探索

粤港澳大湾区轨道交通票务清分系统一体化的建设成为促进城市群经济深度融合、推动区域交通网络高效协同和提升区域交通服务水平的关键环节。为响应干线铁路、城际铁路、市域(郊)铁路、城市轨道交通“四网融合”战略要求,结合粤港澳大湾区轨道交通票务清分系统现状及存在问题,阐述粤港澳大湾区轨道交通区域间、区域内一体化票务需求,剖析轨道交通票务清分系统互联互通方案。在此基础上,建立“1+M+N”3级一体化票务清分系统架构,提出新建1级中心方案、改造2级中心方案、改造线路中心及车站设备方案,为轨道交通票务清分系统一体化提供有力支撑,实现地铁与城际铁路无障碍换乘,促进粤港澳大湾区轨道交通高效协同,推动区域经济的一体化发展。

基于国有企业同一控制下的特殊税务重组路径和方法

国有企业作为国民经济的支柱,伴随着国民经济发展取得了丰硕成果,但在不断发展壮大过程中也出现了企业法人户数多、法人链条长、管理层级多、管理效率低等问题。基于国有企业推动现代化治理体系建设的目标要求,结合国有企业推动压缩管理层级、减少法人户数改革的实际,通过论证国有企业同一控制下企业间采用特殊税务重组压减法人的路径和方法,为国有企业完成改革任务、降低运营管理成本、提高管理效率提供参考。

基于一磷酸腺苷的RAFT接枝棉织物的结构和阻燃性能

采用可逆加成断裂链转移自由基聚合(RAFT)方法,基于纤维基二硫代酸酯类RAFT链转移剂(Cell-CTA),以偶氮二异丁腈为引发剂,以改性一磷酸腺苷(AAMP)为阻燃单体,在纯棉织物上进行RAFT接枝聚合改性,制备了接枝阻燃棉织物(Cell-g-PAAMP)。采用红外光谱、扫描电镜、拉曼光谱等方法对Cell-g-PAAMP的化学结构、表面形貌及其燃烧后残炭的形态和石墨化程度进行了表征。采用热重分析仪、数显氧指数测定仪、织物强力仪、透气性能测试仪对Cell-g-PAAMP的阻燃性能和物理机械性能进行了分析。Cell-g-PAAMP红外光谱中,1199 cm^(-1)处新出现P=O双键的伸缩振动峰,说明已成功制备Cell-g-PAAMP。扫描电镜和拉曼光谱结果表明,Cell-g-PAAMP表面粗糙,有颗粒状物质附着于表面,燃烧后残炭形态保持基本完整且结构致密,石墨化程度提高。与纯棉织物对比,Cell-g-PAAMP初始分解温度降低,热稳定性提高,极限氧指数提高,获得了良好的阻燃效果。Cell-g-PAAMP透气性和断裂强力下降,但断裂伸长率却大幅增加。

无阿片化麻醉在肿瘤手术中的应用进展

外科手术是实体肿瘤治疗的主要方式,围术期麻醉和镇痛管理与术后康复密切相关,甚至有可能影响肿瘤的复发、转移和患者的远期预后。与阿片化麻醉相比,无阿片化麻醉(opioid free anesthesia,OFA)可以降低术后恶心、呕吐等相关不良反应的发生率,改善术后创伤应激反应导致的免疫功能抑制状态,提高机体抗肿瘤的免疫能力,并促进患者术后快速康复。现就OFA在肿瘤手术临床应用进展进行综述,为围手术期麻醉管理提供参考。

无线能量传输技术在机械循环支持装置中的应用研究进展

机械循环支持(MCS)装置已广泛用于心力衰竭(HF)患者的治疗,但能量传输经皮电缆导致的感染问题严重降低了患者长期生存率。将无线能量传输(WPT)技术应用于MCS装置,实现装置的无线供电和完全植入是降低感染的有效手段。WPT技术无需借助经皮电缆传输能量,避免经皮电缆导致的感染,提高患者生活质量,是MCS装置更为理想的能量传输方式。综述经皮能量传输(TET)、自由范围谐振电能传输(FREE-D)、共面能量传输(CET)和超声经皮能量传输(UTET)4种WPT技术的研究进展及其在18种MCS装置中的应用情况,讨论现有WPT技术的优劣和应用于MCS装置的瓶颈并展望未来发展方向,为后续MCS装置的WPT研究提供参考。