儿童难治性食管狭窄应用全覆膜支架治疗的并发症及处理对策

目的探讨应用镍钛合金全覆膜食管支架治疗儿童难治性食管狭窄的并发症及处理对策。方法回顾性分析2009年5月-2016年12月于该院应用镍钛合金网格编织型的覆膜支架治疗9例难治性食管狭窄患儿的临床资料,支架置入术后定期随访,观察患儿支架置入后的效果及并发症等。结果 9例患儿均成功行支架置入术,所有患儿置入后狭窄梗阻症状均得到明显缓解;术后1~7 d所有患儿均有呕吐及不同程度的胸痛症状;1例患儿置入后因哭闹不安不能忍受于术后36 h取出支架;2例于支架取出3个月后出现再狭窄,其中1例并发肉芽组织增生;1例食管穿孔患儿支架置入术1周出现支架移位贴壁不良,原支架取出后重置新支架,2个月后再行支架取出,瘘口愈合。结论镍钛合金全覆膜金属支架治疗儿童难治性良性食管狭窄安全有效,但与支架置入相关的并发症不容忽视,支架个体化设计与并发症的及时处理对提高临床疗效至关重要。

磁控胶囊内镜在儿童再发性腹痛中的诊断价值

目的探讨磁控胶囊内镜在儿童再发性腹痛(RAP)中的应用价值。方法回顾性分析2021年1月-2021年6月上海交通大学医学院附属儿童医院内镜中心125例行磁控胶囊内镜检查的RAP患儿的临床资料,分析镜下病变检出情况和胶囊内镜在消化道各部位运行时间等。结果125例患者中,35例拟行全小肠检查(1例因吞服失败而未完成),90例在磁控条件下行食管及胃部检查。磁控胶囊内镜在食管内的中位运行时间为8.5 (5.3,12.5) s,在胃内的中位运行时间为49.0 (17.7,94.0) min,行全小肠检查的患儿,胶囊内镜在小肠内的中位运行时间为252.0 (192.5,340.0) min,全小肠检查完成率为97.1%(34/35),检查完成后所有胶囊内镜均顺利排出体外。上消化道病变检出率为71.8%(89/124),小肠病变检出率为68.6%(24/35)。磁控胶囊内镜对儿童RAP的总体病变检出率为73.4%(91/124)。结论磁控胶囊内镜在RAP患儿胃肠道病变检查中有较高的病变检出率,且安全无痛苦,具有一定的临床应用价值。

C/C-SiC-ZrB_(2)-ZrC复合材料在等离子体高频脉冲达2000次过程中的烧蚀特性

研究等离子体单次毫秒级加载条件下C/C-SiC-ZrB_(2)-ZrC复合材料在不同次数高频脉冲过程中的烧蚀行为与机理。烧蚀试验在自研台架上进行,测试过程中等离体子体-空气射流交替冲击试样表面。结果表明,随冲击次数增加,前1000次内烧蚀率迅速下降,随后在达2000次过程中烧蚀率缓慢降低。微结构、物相及烧蚀表面温度特征说明烧蚀试样表面形成一层不完整的混合陶瓷烧蚀产物层,且裸露的碳含量在1000次冲击烧蚀以后趋于稳定。烧蚀产物层削弱了热应力诱发的机械剥蚀并保护其亚层的碳不被侵蚀,进而导致烧蚀率的演变。

Dynamic alterations in early intestinal development,microbiota and metabolome induced by in ovo feeding of L-arginine in a layer chick model

Background:Prenatal nutrition is crucial for embryonic development and neonatal growth,and has the potential to be a main determinant of life-long health.In the present study,we used a layer chick model to investigate the effects of in ovo feeding(IOF)of L-arginine(Arg)on growth,intestinal development,intestinal microbiota and metabolism.The treatments included the non-injected control,saline-injected control,and saline containing 2,6,or 10 mg Arg groups.Results:IOF Arg increased early intestinal index and villus height,and enhanced uptake of residual yolk lipid,contributing to subsequent improvement in the early growth performance of chicks.Prenatal Arg supplementation also increased the early microbialα-diversity,the relative abundance of Lactobacillales and Clostridiales,and decreased the relative abundance of Proteobacteria of cecum in chicks.Furthermore,the shift of cecal microbiota composition and the colonization of potential probiotics were accelerated by IOF of Arg.Simultaneously,metabolomics showed that metabolisms of galactose,taurine-conjugated bile acids and lipids were modulated to direct more energy and nutrients towards rapid growth of intestine at the beginning of post-hatch when embryos received IOF of Arg.Conclusions:Prenatal Arg supplementation showed beneficial effects on the early intestinal development,cecal microbiota and host metabolism of layer chicks,contributing to subsequent improvement in the early growth performance.These findings provide new insight into the role of IOF of Arg in the establishment of the gut microbiota of newly-hatched layer chicks,and can expand our fundamental knowledge about prenatal nutrition,early bacterial colonization and intestinal development in neonate.

Pure squamous cell carcinoma of the gallbladder locally invading the liver and abdominal cavity: A case report and review of the literature

BACKGROUND Gallbladder squamous cell carcinoma(GBSCC)is a rare subtype of malignancy and accounts for only 2%-3%of gallbladder malignancies.Due to its rapid development,most patients with GBSCC initially present with an advanced stage of the disease and hence a poor prognosis.The clinicopathological and biological features of SCC remain to be fully elucidated,owing to its uncommon occurrence.The majority of currently available data only described individual case reports or series analyses of trivial cases.CASE SUMMARY A 64-year-old man was admitted for progressively poor abdominal distension and pain.Liver computed tomography(CT)showed infiltration of gallbladder carcinoma into the adjacent liver,and enlarged retroperitoneal lymph nodes.The patient underwent radical cholecystectomy.Part of the mass was grey and soft,and the neoplastic section showed a purulent-necrotic lesion.Hematoxylin and eosin staining revealed a moderately differentiated SCC.Immunohistochemical studies showed strong staining of the tumor for AE1/3 and CK5/6.Staining for CK19,CK7,and CAM5.2 was positive in the cytoplasm.Systemic chemotherapy was not administered because of the patient’s poor physical condition.After five months,CT and magnetic resonance cholangiopancreatography showed multiple metastases in the liver and abdominal cavity.CONCLUSION Squamous components of GBSCC may explain the complex biological behavior,and CD109 may be involved in the pathogenesis.

Microvesicles with mitochondrial content are increased in patients with sepsis and associated with inflammatory responses

BACKGROUND Endothelial activation plays an important role in sepsis-mediated inflammation,but the triggering factors have not been fully elucidated.Microvesicles carrying mitochondrial content(mitoMVs)have been implicated in several diseases and shown to induce endothelial activation.AIM To explore whether mitoMVs constitute a subset of MVs isolated from plasma of patients with sepsis and contribute to endothelial activation.METHODS MVs were isolated from human plasma and characterized by confocal microscopy and flow cytometry.Proinflammatory cytokines,including interleukin(IL)-6,IL-8 and tumour necrosis factor(TNF)-α,and soluble vascular cell adhesion molecule(sVCAM)-1 were detected by ELISA.Human umbilical vein endothelial cells(HUVECs)were stimulated with the circulating MVs to evaluate their effect on endothelial activation.RESULTS MitoMVs were observed in plasma from patients with sepsis.Compared with those in healthy controls,expression of MVs,mitoMVs,proinflammatory cytokines and sVCAM-1 was increased.The number of mitoMVs was positively associated with TNF-αand sVCAM-1.In vitro,compared with MVs isolated from the plasma of healthy controls,MVs isolated from the plasma of patients with sepsis induced expression of OAS2,RSAD2,and CXCL10 in HUVECs.MitoMVs were taken up by HUVECs,and sonication of MVs significantly reduced the uptake of mitoMVs by HUVECs and expression of the above three type I IFNdependent genes.CONCLUSION MitoMVs are increased in the plasma of patients with sepsis,which induces elevated expression of type I IFN-dependent genes.This suggests that circulating mitoMVs activate the type I IFN signalling pathway in endothelial cells and lead to endothelial activation.

Effect of the microporous structure of ammonium perchlorate on thermal behaviour and combustion characteristics

Ammonium perchlorate(AP)is the component with the highest content in composite propellants,and it plays a crucial role in propellant performance.In view of the effects of low-temperature AP thermal decomposition on thermal safety and combustion characteristics,porous ammonium perchlorate(PAP)samples with different mass losses were first prepared by thermal convection heating,and the structures were characterized and analysed.Second,the effects of decomposition degree on the thermal decomposition characteristics of PAP were studied by DSC-TG.Finally,the combustion characteristics of AP/Al binary mixtures were tested with high-speed photography and in a sealed bomb.The results showed that low-temperature decomposition of AP resulted in formation of porous structures for AP particles.The pores first appeared near the surfaces of the particles and began from multiple points at the same time.The pores increased in size to approximately 5 mm and then expanded,and finally,the AP particles were full of pores.After partial decomposition,the crystal structure of AP remained unchanged,but the low and high decomposition temperatures decreased obviously.The decomposition rate accelerated.Due to the porous structure of PAP,the combustion rate of the AP/Al system increased obviously with increasing decomposition of AP.The relationship between the combustion rate and the mass loss was approximately linear under open conditions,and it was exponential for a high-pressure environment.A computational model of the combustion process for the AP/Al binary system was established to explain the effects of pore structure and pressure on the combustion process.

Preparation and properties of ZrO_(2)-strengthened porous mullite insulation materials using Y_(2)O_(3) additive

ZrO_(2)-strengthened porous mullite insulation materials were prepared by foaming technology utilizing ZrSiO_(4) and Al_(2)O_(3) as primary materials and Y_(2)O_(3) as an additive.The effects of Y_(2)O_(3) contents on the phase composition,microstructure,mechanical properties,and heat conductivity of the porous mullite insulation materials were investigated.A suitable Y_(2)O_(3) content could promote phase transition of monoclinic ZrO_(2)(m-ZrO_(2))to tetragonal ZrO_(2)(t-ZrO_(2)),reduce pore size,and improve the strengths of as-prepared specimens.The cold crushing strength and bending strength of as-prepared specimens with a 119µm spherical pore size using 6 wt.%Y_(2)O_(3) were 35.2 and 13.0 MPa,respectively,with a heat conductivity being only 0.248 W/(m K).

High-temperature wetting behavior between slag and refractory

Slag corrosion is one of the main factors of the damage of refractory,and its primary manifestations involve the melting of refractory in slag and the slag penetration into refractory,both of which are highly related to the wetting behavior between slag and refractory.The high-temperature wettability could be characterized by parameters including the surface tension,adhesion work,and spreading coefficient of the slag on refractory surface,and it could be suppressed by altering the slag/refractory interface,thus resulting in an improved anti-corrosion performance.From this,the key knowledges of the slag corrosion,theory of wetting behavior and test of high-temperature contact angle were firstly summarized.Then,the major factors influencing the high-temperature slag wetting behavior were discussed based on the aspects of slag composition,refractory composition,and surface microstructure.Finally,the future research direction was proposed in this field.

Permanent lining castable with low bulk density and thermal conductivity:bauxite castable for tundish obtained by adding pearlescent sand

The low thermal conductivity and light mass of castables for tundish permanent linings are crucial for minimizing the heat loss of molten steel.In consideration of the low bulk density and thermal conductivity of pearlescent sand,the thermal insulation performance of castables was attempted to be improved by adding pearlescent sand.Pearlescent sand was modified to prevent the strength of its porous structure from deteriorating.The modification mechanism of pearlescent sand and the effect of pearlescent sand on the performance of bauxite castables were studied.The results suggested that the addition of the modified pearlescent sand significantly raised the apparent porosity and decreased the bulk density of bauxite castable.At 1000℃,the bulk density of more than 60%of the modified pearlescent sand-bauxite castable was only 2.03 g/cm^(3).The mechanical properties and thermal shock resistance of the modified pearlescent sand-bauxite castable were inferior to those of conventional bauxite castable but were adequate to meet the use conditions of casta-bles for tundish permanent linings.At high temperatures of 200-800℃,the thermal conductivity of more than 60%of the modified pearlescent sand-bauxite castable was smaller than that of conventional bauxite castable.The addition of the modified pearlescent sand can greatly reduce the thermal conductivity and bulk density of bauxite castable.

High-performance hot-warm rolled Zn-0.8Li alloy with nano-sized metastable precipitates and sub-micron grains for biodegradable stents

Fabricated through a newly developed hot-warm rolling process,Zn-0.8 Li(wt%)alloy has ideal strength and ductility far beyond the mechanical benchmark of materials for biodegradable stents.Precipitation of needle-like Zn in primary p-LiZn4 phase is observed in Zn-Li alloy for the first time.Orientation relationship between them can be described as[1-213]β//[2-1-10](Zn),(10-10)βabout 4.5°from(0002)(Zn).Zn grains with an average size of 640 nm exhibit strong basal texture,detected by transmission electron back-scatter diffraction.Li distribution is determined by three-dimensional atom probe,which reveals the formation of nano-sized metastableα-Li2Zn3 precipitates with a number density of 7.16×10^22 m^-3.The fine lamellar Zn+β-LiZn4 structure,sub-micron grains and the nano-sized precipitates contribute to the superior mechanical properties.

Design biodegradable Zn alloys: Second phases and their significant influences on alloy properties

Alloying combined with plastic deformation processing is widely used to improve mechanical properties of pure Zn.As-cast Zn and its alloys are brittle.Beside plastic deformation processing,no effective method has yet been found to eliminate the brittleness and even endow room temperature super-ductility.Second phase,induced by alloying,not only largely determines the ability of plastic deformation,but also influences strength,corrosion rate and cytotoxicity.Controlling second phase is important for designing biodegradable Zn alloys.In this review,knowledge related to second phases in biodegradable Zn alloys has been analyzed and summarized,including characteristics of binary phase diagrams,volume fraction of second phase in function of atomic percentage of an alloying element,and so on.Controversies about second phases in Zn-Li,Zn-Cu and Zn-Fe systems have been settled down,which benefits future studies.The effects of alloying elements and second phases on microstructure,strength,ductility,corrosion rate and cytotoxicity have been neatly summarized.Mg,Mn,Li,Cu and Ag are recommended as the major alloying elements,owing to their prominent beneficial effects on at least one of the above properties.In future,synergistic effects of these elements should be more thoroughly investigated.For other nutritional elements,such as Fe and Ca,refining second phase is a matter of vital concern.

Effects of rarefaction on the characteristics of micro gas journal bearings

Given the definition of the reference Knudsen number for micro gas journal bearings,the range in the number is related to the viscosity of air at different temperatures. A modified Reynolds equation for micro gas journal bearings based on Burgdorfer's first-order slip boundary condition is proposed that takes into account the gas rarefaction effect. The finite difference method (FDM) is adopted to solve the modified Reynolds equation to obtain the pressure profiles,load capacities and attitude angles for micro gas journal bearings at different reference Knudsen numbers,bearing numbers and journal eccentricity ratios. Numerical analysis shows that pressure profiles and non-dimensional load capacities decrease markedly as gas rarefaction in-creases. Attitude angles change conversely,and when the eccentricity ratio is less than 0.6,the attitude angles rise slightly and the influence of the reference Knudsen number is not marked. In addition,the effect of gas rarefaction on the non-dimensional load capacity and attitude angle decreases with smaller bearing numbers.

Hierarchical microstructure and two-stage corrosion behavior of a high-performance near-eutectic Zn-Li alloy

In order to improve mechanical and corrosion properties of biodegradable pure Zn,a knowledge-based microstructure design is performed on Zn-Li alloy system composed of hard β-LiZn_(4) and soft Zn phases.Precipitation and multi-modal grain structure are designed to toughen β-LiZn_(4) while strengthen Zn,resulting in high strength and high ductility for both the phases.Needle-like secondary Zn precipitates form in β-LiZn4,while fine-scale networks of string-like β-LiZn4 precipitates form in Zn with a tri-modal grain structure.As a result,near-eutectic Zn-0.48 Li alloy with an outstanding combination of high strength and high ductility has been fabricated through hot-warm rolling,a novel fabrication process to realize the microstructure design.The as-rolled alloy has yield strength(YS) of 246 MPa,the ultimate tensile strength(UTS) of 395 MPa and elongation to failure(EL) of 47 %.Immersion test in simulated body fluid(SBF) for 30 days reveals that Li-rich products form preferentially at initial stage,followed by Zn-rich products with prolonged time.Aqueous insoluble Li_(2) CO_(3) forms a protective passivation film on the alloy surface,which suppresses the average corrosion rate from 81.2 μm/year at day one down dramatically to 18.2 μm/year at day five.Afterwards,the average corrosion rate increases slightly with decrease of Li2 CO_(3) content,which undulates around the clinical requirements on corrosion resistance(i.e.,20 μm/year) claimed for biodegradable metal stents.

Foam-gelcasting preparation of porous Si C ceramic for high-temperature thermal insulation and infrared stealth

Porous SiC ceramics(PSCs)are promising lightweight and efficient thermal insulators that can evade infrared detection by reducing the surface temperature of the protected object,which plays a crucial role in the development of new military equipment.However,the controllable synthesis of PSCs with both hierarchical pore structure and thermal/mechanical stability remains challenging.In this work,such PSCs were prepared by a facile foam-gelcasting/solid-state reaction method,using silicon powders and glucose-derived carbon as starting materials.The favorable dispersibility and wettability of hydrophilic carbon microspheres and the in-situ formed SiC guarantee the highly porous structure(92.8%porosity),comparable bulk density(0.20 g·cm^(-3))and reasonable mechanical property of the product.The designed PSCs performed outstanding high-temperature performance,especially thermal insulation in both oxidizing and inert atmospheres.More importantly,the composite architecture of PSCs and low emissivity layer(Al foil)exhibited desirable infrared stealth property(at a temperature up to 1100℃),significantly extending the operating temperature range of thermal camouflage material.The unique combination of excellent properties would make PSCs a potential candidate material for future thermal protection and infrared stealth applications in an extreme environment.

The calcium-sensing receptor participates in testicular damage in streptozotocin-induced diabetic rats

Male infertility caused by testicular damage is one of the complications of diabetes mellitus. The calcium-sensing receptor （CaSR） is expressed in testicular tissues and plays a pivotal role in calcium homeostasis by activating cellular signaling pathways, but its role in testicular damage induced by diabetes remains unclear. A diabetic model was established by a single intraperitoneal injection of streptozotocin （STZ, 40 mg kg-1） in Wistar rats. Animals then received GdCl3 （an agonist of CaSR, 8.67 mg kg-1）, NPS-2390 （an antagonist of CaSR, 0.20 g kg-~）, or a combination of both 2 months after STZ injection. Diabetic rats had significantly lower testes weights and serum levels of testosterone compared to healthy rats, indicating testicular damage and dysfunction in STZ-induced diabetic rats. Compared with healthy controls, the testicular tissues of diabetic rats overexpressed the CaSR protein and had higher levels of malondialdehyde （MDA）, lower superoxide dismutase （SOD） and glutathione peroxidase （GSH-Px） activity, and higher numbers of apoptotic germ cells. The testicular tissues from diabetic rats also expressed lower levels of Bcl-2 and higher levels of Bax and cleaved caspase-3 in addition to higher phosphorylation rates of c-Jun NH2-terminal protein kinase （JNK）, p38, and extracellular signaling-regulated kinase （ERK） 1/2. The above parameters could be further increased or aggravated by the administration of GdCI3, but could be attenuated by injection of NPS-2390. In conclusion, the present results indicate that CaSR activation participates in diabetes-induced testicular damage, implying CaSR may be a potential target for protective strategies against diabetes-induced testicular damage and could help to prevent infertility in diabetic men.

Catalytic Asymmetric Mannich-Type Reaction Enabled by Efficient Dienolization of α,β-Unsaturated Pyrazoleamides

(E)-α,β-Unsaturated pyrazoleamides undergo facile dienolization to furnish copper(I)-(1Z,3Z)-dienolates as the major in the presence of a copper(I)-(R)-DTBM-SEGPHOS catalyst and EtgN,which react with aldimines to afford syn-vinylogous products as the major dia-stereoisomers in high regio-and enantioselectivities.In some cases,the diastereoselectivity is low,possibly due to the low ratio of copper(I)-(1Z,3Z)-dienolates to copper(I)-(1Z,3E)-dienolates.

New numerical solution for self-acting gas journal bearings

Taking a small pressure change in the gas film of self-acting gas-lubricated journal bearings into account, the corresponding nonlinear Reynolds equation is linearized through appropriate approximation and a modified Reynolds equation is derived and solved by means of the finite difference method (FDM). The gas film pressure distribution of a self-acting gas-lubricated journal bearing is attained and the load capacity is calculated. The numerical solution has a better agreement with experimental data than a direct numerical solution for different values of the bearing number. It is of interest to note that the eccentricity ratio, at which the new numerical solution is in better agreement with experimental data, is different when the bearing number is changing. The new numerical solution is slightly larger when the eccentricity ratio is smaller, and becomes slightly smaller when the eccentricity ratio is larger.

One-way quantum deficit and quantum coherence in the anisotropic X Y chain

In this study, we investigate pairwise non-classical correlations measured using a one-way quantum deficit as well as quantum coherence in the XY spin-1/2 chain in a transverse magnetic field for both zero and finite temperatures. The analytical and numerical results of our investigations are presented. In the case when the temperature is zero, it is shown that the one-way quantum deficit can characterize quantum phase transitions as well as quantum coherence. We find that these measures have a clear critical point at λ = 1. When λ 1, the one-way quantum deficit has an analytical expression that coincides with the relative entropy of coherence. We also study an XX model and an Ising chain at the finite temperatures.

Recurrent panic attack and bilateral hippocampus lesions as main manifestation in an autoimmune encephalitis associated with primary biliary cirrhosis

To the Editor:Autoimmune encephalitis(AE)is a group of autoantibodies-mediated central nervous system(CNS)inflammatory diseases with a wide spectrum of neuropsychiatric symptoms?1*Cogn让ive impairment,epileptic seizures,and mental behavior disorder,along with both limbic and extra-limbic brain structures lesions in radiologic imaging,are the most common manifestation.Of late years,AE has been widely recognized and could be combined with multiple autoimmune diseases;however,little has been described about co-existence of the AE and primary biliary cirrhosis(PBC).