Continuous positive airway pressure for treating hypoxemia due to pulmonary vein injury:A case report

BACKGROUND Vascular injury during thoracoscopic surgery for esophageal cancer is a rare but life-threatening complication that can lead to severe hypotension and hypoxemia.Anesthesiologists need to provide rapid and effective treatment to save patients'lives.CASE SUMMARY A 54-year-old male patient was scheduled to undergo a thoracoscopic-assisted radical resection of esophageal cancer through the upper abdomen and right chest.While dissociating the esophagus from the carina through the right chest,unexpected profuse bleeding occurred from a suspected pulmonary vascular hemorrhage.While the surgeon attempted to achieve hemostasis,the patient developed severe hypoxemia.The anesthesiologist implemented continuous positive airway pressure(CPAP)using a bronchial blocker(BB),which effectively improved the patient’s oxygenation and the operation was completed success-fully.CONCLUSION CPAP using a BB can resolve severe hypoxemia caused by accidental injury of the left inferior pulmonary vein during surgery.

后腹腔镜肾实质切开取石术治疗肾脏铸形结石(附23例报告)

目的探讨后腹腔镜技术处理肾脏铸形结石的手术要点与临床应用价值。方法 2013年8月-2017年10月,对23例不适合经皮肾镜取石术(PCNL)的患者给予后腹腔镜肾实质切开取石,结石均为单侧,至少占据一个肾盏和全部肾盂,平均直径2.8(2.3~3.8)cm。术中阻断肾动脉后,经吸引器注入冰水给予肾表面降温,沿Brodel线切开肾实质取出结石,根据肾实质厚度以QuillTM双向倒刺线进行全层或分层连续缝合关闭创缘。结果 23例手术均获成功。手术时间75~135 min,中位数95 min;肾脏热缺血时间17~35 min,中位数25 min;术中估计失血量25~350 ml,中位数105 ml,术中术后均未输血。术后5例出现血尿,均在3.0 d后消失;另有3例出现漏尿,于术后3.0~5.0 d消失。术后复查无明显残石。术后平均随访10(2~18)个月,静脉尿路造影(IVU)显示患肾梗阻程度明显减轻。结论后腹腔镜肾实质切开取石术是一种安全、有效的微创手术方法,对于不适合行PCNL的患者,有望作为PCNL的替代治疗措施,但需进一步增加例数并观察远期疗效。

吸电子和亲水性Co-卟啉促进电催化氧还原反应的研究

研究影响电催化氧还原反应活性的因素对于合理设计高效的氧还原反应催化剂至关重要。调节催化剂电子结构通常被用于精确调控电催化氧还原反应活性。然而,该反应发生在液/气/固界面,很少有报道调控分子催化剂的亲疏水性来提高其催化活性。在此,我们报道了两种钴卟啉NO_(2)-CoP(5,10,15,20-四(4-硝基苯基)钴卟啉)和5F-CoP(5,10,15,20-四(五氟苯基)钴卟啉)并研究了其电催化氧还原反应性能。通过同时调控meso-位取代基的电子结构和亲水性能,NO_(2)-CoP显示出比5F-CoP更高的电催化氧还原反应活性,其半波电位向阳极方向移动近60 mV。NO_(2)-CoP比5F-CoP具有更好的亲水性。理论计算表明,NO_(2)-CoP比5F-CoP更容易有效地与O_(2)分子结合形成Co^(Ⅲ)-O_(2)^(·-)。这项工作提供了一个简单而有效的策略,通过使用吸电子和亲水取代基来提高钴卟啉的氧还原反应活性。该策略对于设计和开发其他用于电催化的分子催化剂体系也具有重要的启发意义。

Processing of a low-costγ-γ'NiPtAl coating with improved oxidation resistance

A novelγ-γ'(Ni solid solution—Ni_(3)Al)NiPtAl coating was produced on advanced single-crystal(SC)superalloy N5 by electroplating of a thin Pt coating with~3μm in thickness followed by heat treatment at 1000℃in vacuum.For comparison,a traditionalγ-γ'NiPtAl coating was also produced by electroplating of a thick Pt coating with~6μm in thickness followed by heat treatment at 1100℃in vacuum.The novel coating has a mass gain of~0.5 mg·cm^(-2)after 100 h 1-h cyclic oxidation at 1150℃,showing better oxidation resistance than the traditional coating.An oxide scale mostly consisting ofα-Al_(2)O_(3)grew on the novel coating because the element Cr from the SC alloy substrate contributes to the formation ofα-Al_(2)O_(3).Pt content in the novel coating has significant effect on the oxidation resistance.The optimized Pt content in the coating is about 16 at%,which is helpful to reduce the diffusion of harmful elements from the substrate into the coating but also to reduce the cost of the coating.

Cyclic oxidation behavior of electron beam physical vapor deposition NiAlHf and NiAlHfCrSi coatings at 1150℃

NiAlHf and NiAlHfCrSi coatings were deposited by electron beam physical vapor deposition(EBPVD).The grain size and orientation of NiAlHf and NiAlHfCrSi coatings were determined by electron backscatter diffraction(EBSD).The NiAlHf coating reveals a more uniform grain size compared to NiAlHfCrSi coating,while the NiAlHfCrSi coating shows a<111>preferential orientation which is parallel to the normal direction of the surface of the coating.The cyclic oxidation behavior of NiAlHf and NiAlHfCrSi coatings at 1150℃was investigated.Compared to NiAlHf coating,the NiAlHfCrSi coating shows improved resistance to cyclic oxidation and scale spallation.The effect of grain size and orientation on the cyclic oxidation behavior of NiAlHf and NiAlHfCrSi coatings were investigated at 1150℃.

High-temperature oxidation behaviour of minor Hf-dopedβ-NiAI single crystals in dry and humid atmospheres

Oxidation behaviour of undopedβ-NiAl andβ-NiAl-0.05Hf single crystals were investigated at 1100℃in 20 vol%O_(2)+Ar and 15 vol%H2O+Ar,respectively.On contrary to the well-known beneficial effect of Hf additions on the oxidation behaviour of polycrystallineβ-NiAl,severe-scale spallation is observed forβ-NiAl-0.05Hf single-crystal alloy,especially in dry atmosphere.It is proposed that the presence of the grain boundaries in the polycrystalline substrate enables proper content of Hf segregating at the grain boundaries of the oxide scale and at the scale-substrate interface,which promotes the conditions required for reactive element effect.Once the reactive element effect of Hf does not work,its strong affinity with oxygen will accelerate the process of high-temperature oxidation.However,the absence of the grain boundaries as fast diffusion paths partially compromises the adverse influence of water vapour on cyclic oxidation resistance ofβ-NiAl single crystal,resulting in considerable suppression of the oxidation rate and less loss of protection compared with that in dry atmosphere.In addition,interfacial cavities are observed in dry and humid atmospheres,which may eventually result in the spallation of the oxide scale.

Oxidation behaviour of electron beam physical vapour deposition β-NiAlHf coatings at 1100℃ in dry and humid atmospheres

NiA1 intermetallic compounds attract increas- ing attention for high-temperature applications due to their combination of excellent properties, especially as metallic protective coatings on superalloys or as bond coats in thermal barrier coatings （TBCs）. Oxidation behaviour of the β-NiA1Hf coatings prepared by electron beam physical vapour deposition （EB-PVD） was investigated at 1100 ℃ for short time and 100h in 20% 02＋Ar and 15 % H20 ＋ Ar, respectively. The results of mass changes re- veal that the addition of minor reactive element Hf sig- nificantly improves the cyclic oxidation resistance of the 13- NiA1 coatings in both dry and humid atmospheres. During the initial oxidation stage, water vapour retards the phase transformation from 0-A1203 to a-A1203. Moreover, com- pared with the case in dry atmosphere, water vapour sig- nificantly reduces the surface roughness of the oxide scales formed on EB-PVD β-NiA1Hf coatings after 100 h cyclic oxidation, which corresponds with the difference of surface morphologies of the oxide scales.

Deposition of TiN/TiAlN multilayers by plasma-activated EB-PVD:tailored microstructure by jumping beam technology

Plasma-activated electron beam-physical vapor deposition（EB-PVD）was used for depositing nitride multilayer coatings in this work.Different from the conventional coating methods,the multilayers were obtained by manipulating electron beam（EB）to jump between two different evaporation sources alternately with variable frequencies（jumping beam technology）.The plasma activation was generated by a hollow cathode plasma unit.The deposition process was demonstrated by means of tailoring TiN/TiAlN multilayers with different modulation periods（M1：26.5 nm,M2：80.0 nm,M3：6.0 nm,M4：4.0 nm）.The microstructure and hardness of the multilayer coatings were comparatively studied with TiN and TiAlN singlelayer coatings.The columnar structure of the coatings（TiN,TiAlN,M1,M2）is replaced by a glassy-like microstructure when the modulation period decreases to less than 10 nm（M3,M4）.Simultaneously,superlattice growth occurs.With the decrease of modulation period,both the hardness and the plastic deformation resistance（H^3/E^2,H-hardness and E-elastic modulus）increase.M4coating exhibits the maximum hardness of（49.6±2.7）GPa and the maximum plastic deformation resistance of^0.74 GPa.

Novel long laminar plasma sprayed hybrid structure thermal barrier coatings for high-temperature anti-sintering and volcanic ash corrosion resistance

1.Introduction The artificial-designed segmentation cracks in the ceramic layer of the thermal barrier coatings is an excellent choice by using the atmospheric plasma spray(APS)method under a low cost on the applications of aircraft engines or gas turbine engines.The residual thermal stress energy of the coatings with a certain inter-space of vertical cracks during the thermal cycling test is released through the cracks.

Thermal cycling performance of La_(2)Ce_(2)O_(7)/YSZ TBCs with Pt/Dy co-doped NiAl bond coat on single crystal superalloy

Thermal barrier coatings(TBCs) consisting ofLa_(2)Ce_(2)O_(7)(LCO) and Y_(2)O_(3)-stabilized-ZrO_(2)(YSZ) doubleceramic layer and Dy/Pt co-doped NiAl bond coat were produced by electron beam physical vapor deposition(EBPVD). Thermal cyclic performance of the TBCs was evaluated by flame shock testing at 1300 ℃. For comparison, the TBCs with a undoped NiAl bond coat were also studied. The microstructural evolution and failure mechanisms of the above TBCs during thermal cycling were investigated. Spallation failure of the TBCs with the undoped bond coat occurs after around 500 cycles by cracking at the interface between YSZ ceramic layer and thermally grown oxides(TGO) layer. The TBCs with Pt/Dy modified bond coat reveal improved interface bonding even after 1200 thermal cycles, whereas some delamination cracks are presented in the LCO layer. On the other hand,the Pt/Dy modified bond coat effectively suppresses the formation of the needle-like topologically closed packed phases(TCP) in the single crystal superalloy.

Surface roughness affects metastable non-wetting behavior of silicate melts on thermal barrier coatings

Airborne silicate pollutants in flight corridors pose a serious threat to aviation safety whose severity is directly linked to the wettability of molten silicates on thermal barrier coatings(TBCs)at high temperatures(1200–2000℃).Despite its importance,the wettability of silicate melt on TBCs has not been well investigated.In particular,the surface morphology characteristics of TBCs can be expected to have a first-order effect on the wettability of silicate melt on such TBCs.Here,a series of atmospheric plasma spray(APS)yttria-stabilized zirconia(YSZ)TBCs with varying surface roughness were generated through the application of mechanical polishing.The metastable nonwetting behavior of three representative types of airborne silicate ash(volcanic ash,fly ash and a synthetic calcium–magnesium–aluminum–silicates(CMAS)powder)on these TBCs with varying surface roughness was investigated.It was observed that the smoother the surface of TBCs was,the larger the contact angle was with the molten silicate melts,and consequently,the smaller the area of damage was on the TBCs.Thus,the reduction in TBCs surface roughness(here via mechanical polishing)led to an improvement in the wetting and spreading resistance of TBCs to silicate melts at high temperature.In support of these observations and conclusions,the surface morphology of the TBC(both before and after polishing)had been characterized,and the mechanism of the surface roughness-dependence of wettability had been discussed.These results should contribute to reducing the deposition rate of silicate melt on TBCs,thus extending the lifetime of turbine blades and reducing maintenance costs.

Processing and oxidation behavior of Pt-diffused coatings

Pt-diffused coatings were synthesized on Ni10 Al alloy by electroplating a thin layer of Pt(1-5μm)followed by a diffusion treatment in vacuum at 1000-1100℃.Effects of processing parameters(Pt thickness and vacuum diffusion temperature)on the microstructures and chemical composition of Pt-diffused coatings were investigated.Also,the oxidation behavior of the coatings was studied at1100℃.Pt film reveals nano-sized grain size of 93-113 nm.Vacuum diffusion treatment leads to the grain growth.1-μm Pt film with 1000℃/1 h vacuum diffusion fabricates nano-sized Pt-diffused coating which exhibits the best oxidation resistance.And a single continuous Al2O3 scale forms on the coating with low Al(~9 at%)and Pt(~6 at%)contents.Increasing initial Pt thickness would introduce more defects and cracks,leading to a duplex scale and decreasing the oxidation resistance of Ptdiffused coatings.

Existence patterns of Dy in β-NiAl from first-principles calculations

Intermetallic compound β-NiA1 is a promising material in high temperature applications due to its high melting temperature, high strength, low density, and good oxidation resistance. However, its application remains limited because of its relatively poor cyclic oxidation resistance. Addition of reactive element （RE） Dy can improve the cyclic oxidation of NiA1 alloys significantly. However, the mechanism of Dy addition is not clear. Even the existence pattern of Dy in NiA1 is unspecified. Therefore, in the present study, the impurity formation energies of Dy in stoichiometric NiA1, Ni-rich, and Al-rich NiA1 for the substitution cases were studied by first-principles density functional theory. The results show that Dy could hardly substitute for either Ni or A1 atoms in NiA1. However, calculations for dissolution energies show that Dy could be easily dissolved in AI vacancies in all three types of NiA1, which provides a new existence pattern of Dy in NiA1 beyond experimental detection.

Cyclic oxidation behavior of Cr-/Si-modified NiAlHf coatings on single-crystal superalloy produced by EB-PVD

The Cr-/Si-modified Ni Al Hf coatings were produced on single-crystal（SC） superalloy N5 by electron beam physical vapor deposition（EB-PVD）. The cyclic oxidation behavior of the coatings at 1100 °C was investigated. The microstructures of the oxide scales grown on the coatings were characterized by scanning electron microscope（SEM） with energy-dispersive X-ray spectrum（EDX）,electron probe micro-analyzer（EPMA） and X-ray diffraction（XRD）. The effects of Cr and Si on the cyclic oxidation behavior of the Ni Al Hf coatings were discussed. The addition of Si to the Ni Al Hf Cr coating not only reduces the oxidation rate but also enhances the oxide scale adherence.Owing to the addition of Si in the coating, the segregation of Cr and Mo beneath the oxide scale is effectively avoided,which contributes to enhancing oxide scale adherence.

Microstructure, mechanical and corrosion properties of electron-beam-melted and plasma-transferred arc-welded WC_P/NiBSi metal matrix composites

As one of the new additive manufacturing processes,electron beam melting(EBM)has seen its promising potential in the fabrication of metal matrix composites(MMCs)components with complex geometries.In this work,WC_P/NiBSi MMCs were fabricated by EBM and plasma-transferred arc welding(PTAW)for a comparative study.The microstructures of both samples were examined using a scanning electron microscope(SEM)equipped with an electron backscattered diffraction(EBSD)detector.The macrohardness was tested using a Rockwell hardness method(Type C),while the microhardness was measured using different loadings(0.5-1.0 N)based on different phases.The anti-abrasion performance was tested as per the ASTM G105 standard.The corrosion behavior of the MMCs was also assessed by potentiodynamic polarization.The results indicate that the EBM bulk and the PTAW cladding MMCs exhibit different microstructures due to the different local solidification conditions.This is believed to lead to the varied mechanical properties and corrosion resistance of the MMCs,and the possible mechanisms were also discussed.

Microstructure stability of γ’+β Ni-Al coated single-crystal superalloy N5 annealed at 1100℃

γ’+β Binary-phase Ni-Al coatings were prepared on second-generation single-crystal superalloy Rene N5(N5) substrates by electron beam physical vapor deposition.Inter-diffusion behavior between coatings and substrates at 1100℃ and its effects on microstructure stability of the substrates were investigated.A 3-μm-thick substrate diffusion zone(SDZ) layer forms beneath the coating/substrate interface after 5-h heat treatment.The SDZ layer is composed of γ’-Ni_(3) Al phases and needle-like precipitates growing along(100)(110) or(100) <■> direction.After100-h annealing,the thickness of the SDZ layer increases to~17 μm,much lower than that of the single β-NiAl-coated substrate,while keeping single-crystal microstructure.

Sub-micron Co-Al_(2)O_(3) composite powders prepared by room-temperature ultrasonic-assisted electroless plating

Sub-micron Co-Al_(2)O_(3)composite powders were synthesized by ultrasonic-assisted electroless plating process at room temperature with a one-step activating method pretreatment.The effect of process parameters on plating rate,Co content,and the uniformity of cobalt layer was analyzed by transmission electron microscopy(TEM).The results show that as the initial pH values of plating bath increase,the plating rate increases.The plating rate declines as the load increases when the load of powders is less than 12 g·L^(-1),but increases when the load is greater than 12 g·L^(-1).The relative Co content of the Co-Al_(2)O_(3) powder declines with the powder load increasing.

Microstructural evolution,mechanical properties and degradation mechanism of PS-PVD quasi-columnar thermal barrier coatings exposed to glassy CMAS deposits

Thermal barrier coatings(TBCs) applied in aeroengines tend to be attacked by molten calcia-magnesiaalumino-silicate(CMAS) at high operating temperatures.Yttria-stabilized zirconia(YSZ) coatings with quasicolumnar microstructure were fabricated by plasma spray physical vapor deposition(PS-PVD) technique.The chemic al changes,micros tructural transform ation,mechanical properties and degradation mechanisms of the CM AS-interacted TBCs in the thermal cycling tests were investigated.Feathered YSZ grains were dissolved in the CMAS melts,and then the ZrO_(2) grains were reprecipitated with spherical shape,accompanying with phase transformation from tetragonal(t) to monoclinic(m).The thermal cycling tests reveal that the YSZ coating fails at the early stage due to the attack of CMAS.The fractures in intracolumns lead to partial spallation of the coatings.The failure of the coating occurs at the interfaces between thermally grown oxides(TGO) layer and YSZ topcoat;especially,the hardness and Young's modulus of the YSZ coatings increase intensively,as the coatings were infiltrated by the CMAS for a long time.