Inherited CHEK2 p.H371Y mutation in solitary rectal ulcer syndrome among familial patients:A case report

BACKGROUND Solitary rectal ulcer syndrome(SRUS)is a rare rectal disease with unknown etiology.Data on the genetic background in SRUS is lacking.CASE SUMMARY Here,we report the first case of SRUS in a mother-son relationship.Gene sequencing was conducted on the whole family,which revealed an inherited CHEK2 p.H371Y mutation.The experiment preliminarily revealed that the CHEK2 mutation did not affect the expression of CHEK2 protein,but affected the function of CHEK2,resulting in the expression level changes of downstream genes such as CDC25A.CONCLUSION SRUS is a genetic susceptibility disease where CHEK2 p.H371Y mutation may play a crucial role in the development and prognosis of SRUS.

Effect of long-term thermal exposure on microstructure of laser-welded UNS N10003 alloy

The evolution of the microstructure and tensile rupture mechanism of laser welds in UNS N10003 alloy exposed to 700℃are investigated.Fine M_(6)C carbides precipitate around the primary eutectic M_(6)C-carbides in the fusion zone after 100 h of exposure.During long-term thermal exposure,the size of the fine M_(6)C carbides increased.The eutectic M_(6)C-carbides in the as-welded fusion zone transformed into spherical M_(6)C carbides as the exposure time extends to 10000 h.Additionally,the spherical M_(6)C particles exhibit size coarsening with increasing exposure time.The tensile properties of the welded joints are not adversely affected by the evolution of eutectic M_(6)C-carbides and the coarsening of M_(6)C carbides.

Hepatitis B surface antigen-negative but hepatitis B envelope antigen-positive false occult hepatitis B virus infection:A case report

BACKGROUND Occult hepatitis B infection(OBI)is characterized by the detection of hepatitis B virus(HBV)DNA in serum(usually HBV DNA<200 IU/mL)or the liver but negativity for hepatitis B surface antigen(HBsAg).The diagnosis of OBI relies on the sensitivity of assays used in the detection of HBV DNA and HBsAg.HBsAg assays with inadequate sensitivity or inability to detect HBV S variants may lead to misdiagnosis of OBI in people with overt HBV infection.CASE SUMMARY We report a HBsAg-negative but hepatitis B envelope antigen-positive patient who had a significant HBV DNA level.The patient was initially diagnosed as having OBI.However,sequence analysis revealed a unique insertion of amino acid residues at positions 120-124 in the S protein,which affects the formation of a disulfide bond that is associated with the formation of a loop.It is well known that there is an overlap between the S protein and Pol protein.We found that this new insertion site occurred in polymerase/reverse transcriptase domain,indi-cating that this insertion might be involved in HBV pathogenicity.The patient was finally diagnosed with a false OBI.CONCLUSION An insertion of amino acid residues at positions 120-124 of the S protein affects the formation of immunodominant epitopes and results in negative HBsAg levels.

Synchrotron radiation-based materials characterization techniques shed light on molten salt reactor alloys

From a safety point of view, it is important to study the damages and reliability of molten salt reactor structural alloy materials, which are subjected to extreme environments due to neutron irradiation, molten salt corrosion, fission product attacks, thermal stress, and even combinations of these. In the past few years, synchrotron radiation-based materials characterization techniques have proven to be effective in revealing the microstructural evolution and failure mechanisms of the alloys under surrogating operation conditions. Here, we review the recent progress in the investigations of molten salt corrosion,tellurium(Te) corrosion, and alloy design. The valence states and distribution of chromium(Cr) atoms, and the diffusion and local atomic structure of Te atoms near the surface of corroded alloys have been investigated using synchrotron radiation techniques, which considerably deepen the understandings on the molten salt and Te corrosion behaviors. Furthermore, the structure and size distribution of the second phases in the alloys have been obtained, which are helpful for the future development of new alloy materials.

The copper polymetallic deposits and resource potential in the Tibet Plateau

Many large and super-large copper deposits have been discovered and explored in the Tibet Plateau,which makes it the most important copper resource reserve and development base in China.Based on the work of the research team,the paper summarizes the geological characteristics of the main copper deposits in Tibet and puts forward a further prospecting direction.A series of large accumulated metal deposits or ore districts from subduction of Tethys oceanic crust to India-Asia collisionhave been discovered,such as Duolong Cu(Au)ore district and Jiama copper polymetallic deposit.The ore deposits in the Duolong ore district are located in the lowstand domain,the top of lowstand domain,and the highstand domain of the same magmatic-hydrothermal metallogenic system,and their relative positions are the indicators for related deposits in the Bangong Co-Nujiang metallogenic belt.The polycentric metallogenic model of the Jiama copper polymetallic deposit is an important inspiration for the exploration of the porphyry mineralization related to collision orogeny.Further mineral exploration in the Tibet Plateau should be focused on the continental volcanic rocks related to porphyry-epithermal deposits,orogenic gold deposits,hydrothermal Pb-Zn deposits related to nappe structures,skarn Cu(Au)and polymetallic deposits,and the Miocene W-Sn polymetallic deposits.

Method for detector description transformation to Unity and application in BESⅢ

Detector and event visualization are essential parts of the software used in high-energy physics(HEP)experiments.Modern visualization techniques and multimedia production platforms such as Unity provide impressive display effects and professional extensions for visualization in HEP experiments.In this study,a method for automatic detector description transformation is presented,which can convert the complicated HEP detector geometry from GDML in offline software to 3D modeling in Unity.The method was successfully applied in the BESIII experiment and can be further developed into applications such as event displays,data monitoring,or virtual reality.It has great potential in detector design,offline software development,physics analysis,and outreach for next-generation HEP experiments as well as applications in nuclear techniques for the industry.

Investigation of regulating rheological properties of water-based drilling fluids by ultrasound

Regulating rheological properties of water-based drilling fluids has always been a hot topic.This paper proposed a new method for regulating rheological properties of water-based drilling fluids by ultrasonic field.The experimental results showed that the ultrasound increased the viscosity and yield point of bentonite suspension by reducing the particle size of clay,destroying the network structure between clay particles,increasing the mud yield and the cation exchange capacity of bentonite,and promoting the hydration dispersion of bentonite.The change of rheological property showed a memory effect at room temperature and high temperature.Besides,the ultrasonic energy affected the network structure between clays and polymer chains,thus regulating the rheological properties of the bentonite-polymer system.For two types of drilling fluids investigated,the rheology of the poly-sulfonate drilling fluid was regulated by damaging the grid structure between additives and clays by low-power ultrasound and reducing the clay particle size by high-power ultrasound,while the rheology of the deep-water drilling fluid was mainly regulated by disentangling the spatial grid structure between additives.Additionally,ultrasound showed no effect on the lubricity,inhibition and stability of drilling fluids,which proved the feasibility of ultrasound to regulate rheological properties of water-based drilling fluids.

Fine structure characterization of an explosively-welded GH3535/316H bimetallic plate interface

An explosion-welded technology was induced to manufacture the GH3535/316H bimetallic plates to provide a more cost-effective structural material for ultrahigh temperature,molten salt thermal storage systems.The microstructure of the bonding interfaces were extensively investigated by scanning electron microscopy,energy dispersive spectrometry,and an electron probe microanalyzer.The bonding interface possessed a periodic,wavy morphology and was adorned by peninsula-or island-like transition zones.At higher magnification,a matrix recrystallization region,fine grain region,columnar grain region,equiaxed grain region,and shrinkage porosity were observed in the transition zones and surrounding area.Electron backscattered diffraction demonstrated that the strain in the recrystallization region of the GH3535 matrix and transition zone was less than the substrate.Strain concentration occurred at the interface and the solidification defects in the transition zone.The dislocation substructure in 316H near the interface was characterized by electron channeling contrast imaging.A dislocation network was formed in the grains of 316H.The microhardness decreased as the distance from the welding interface increased and the lowest hardness was inside the transition zone.

Consensus statement on layout and delivery of automatic external defibrillator in China

1.Introduction Sudden cardiac death(SCD)refers to sudden death due to a variety of cardiac causes.It is manifested as a sudden loss of consciousness,cardiac arrest,and respiratory arrest and generally shows early symptoms that are atypical and not easily detected[1].According to a recent study,nearly 544000 patients suffer from SCD every year in China[2].

Firing activities in a fractional-order Hindmarsh–Rose neuron with multistable memristor as autapse

Considering the fact that memristors have the characteristics similar to biological synapses, a fractional-order multistable memristor is proposed in this paper. It is verified that the fractional-order memristor has multiple local active regions and multiple stable hysteresis loops, and the influence of fractional-order on its nonvolatility is also revealed. Then by considering the fractional-order memristor as an autapse of Hindmarsh–Rose(HR) neuron model, a fractional-order memristive neuron model is developed. The effects of the initial value, external excitation current, coupling strength and fractional-order on the firing behavior are discussed by time series, phase diagram, Lyapunov exponent and inter spike interval(ISI) bifurcation diagram. Three coexisting firing patterns, including irregular asymptotically periodic(A-periodic)bursting, A-periodic bursting and chaotic bursting, dependent on the memristor initial values, are observed. It is also revealed that the fractional-order can not only induce the transition of firing patterns, but also change the firing frequency of the neuron. Finally, a neuron circuit with variable fractional-order is designed to verify the numerical simulations.

Hopf bifurcation and phase synchronization in memristor-coupled Hindmarsh–Rose and FitzHugh–Nagumo neurons with two time delays

A memristor-coupled heterogenous neural network consisting of two-dimensional(2D)FitzHugh–Nagumo(FHN)and Hindmarsh–Rose(HR)neurons with two time delays is established.Taking the time delays as the control parameters,the existence of Hopf bifurcation near the stable equilibrium point in four cases is derived theoretically,and the validity of the Hopf bifurcation condition is verified by numerical analysis.The results show that the two time delays can make the stable equilibrium point unstable,thus leading to periodic oscillations induced by Hopf bifurcation.Furthermore,the time delays in FHN and HR neurons have different effects on the firing activity of neural network.Complex firing patterns,such as quiescent state,chaotic spiking,and periodic spiking can be induced by the time delay in FHN neuron,while the neural network only exhibits quiescent state and periodic spiking with the change of the time delay in HR neuron.Especially,phase synchronization between the heterogeneous neurons is explored,and the results show that the time delay in HR neurons has a greater effect on blocking the synchronization than the time delay in FHN neuron.Finally,the theoretical analysis is verified by circuit simulations.

Synchronization coexistence in a Rulkov neural network based on locally active discrete memristor

At present, many neuron models have been proposed, which can be divided into discrete neuron models and continuous neuron models. Discrete neuron models have the advantage of faster simulation speed and the ease of understanding complex dynamic phenomena. Due to the properties of memorability, nonvolatility, and local activity, locally active discrete memristors(LADMs) are also suitable for simulating synapses. In this paper, we use an LADM to mimic synapses and establish a Rulkov neural network model. It is found that the change of coupling strength and the initial state of the LADM leads to multiple firing patterns of the neural network. In addition, considering the influence of neural network parameters and the initial state of the LADM, numerical analysis methods such as phase diagram and timing diagram are used to study the phase synchronization. As the system parameters and the initial states of the LADM change, the LADM coupled Rulkov neural network exhibits synchronization transition and synchronization coexistence.

单通道双导管套鞘法经皮肾镜碎石术治疗复杂性输尿管中上段结石的疗效观察

目的评估单通道双导管套鞘法经皮肾镜碎石术(PCNL)治疗复杂性输尿管中上段结石的疗效及安全性。方法回顾性分析48例复杂性输尿管中上段结石患者的临床资料,其中18例合并同侧肾结石,1例合并重复肾畸形,结石位于上位肾的输尿管内。结果 48例患者在B超引导下顺利穿刺建立经皮肾通道,建立通道后置入双套鞘确定肾盂输尿管连接部时间为(18.0±5.0)min,手术时间为(59.0±6.0)min,结石清除率为96.6%;无感染性休克、大出血和周围脏器损伤等严重并发症,术后对患者随访3~6个月,肾积水程度明显减轻,未出现输尿管狭窄病变。结论对于复杂性输尿管中上段结石患者,单通道双导管套鞘法PCNL是一种安全有效的治疗方法。

右美托咪定预处理联合后处理对心肌缺血再灌注损伤的影响

目的观察右美托咪定预处理联合后处理对心肌缺血再灌注损伤的保护作用。方法选取天津医科大学总医院120例心脏瓣膜置换术患者。随机分为3组,右美托咪定预处理组(pre D组)、右美托咪定后处理组(pos D组)及右美托咪定预处理联合后处理组(pre-pos D组),每组40例。pre D组和pre-pos D组于阻断主动脉前30 min静脉输注右美托咪定1μg/kg,posD组输注等容量生理盐水;pos D组和pre-pos D组于开放主动脉前30 min灌注液中加入右美托咪定0.2～1.0μg/kg进行心脏灌注,pre D组灌注液中加入等容量生理盐水。观察麻醉诱导前5 min(T_0)、开放主动脉后15 min(T_1)、体外心肺转流(CPB)结束时(T_2)、术后4 h(T_3)、术后16 h(T_4)、术后36 h(T_5)、术后72 h(T_6)的心率(HR)、平均动脉压(MAP)及术中脑电双频指数(BIS)的变化,记录心脏复跳时间和心脏复跳情况,记录3组前并行循环时间(T_(pre))、主动脉阻断时间(T_(ab))及后并行循环时间(T_(pos))。检测各时间点血浆肿瘤坏死因子α(TNF-α)、白细胞介素-6(IL-6)、血清心肌肌钙蛋白(cTn I)浓度及肌酸激酶同工酶(CK-MB)活性。结果不同时间点3组HR、MAP值差异无统计学意义(P>0.05)。T_1～T_6时pre-posD组血浆TNF-α浓度低于preD和posD组(P<0.05)。T_2～T_6时pre-posD组血浆IL-6浓度低于preD组和posD组(P<0.05)。T_1～T_6时pre-posD组血浆CK-MB活性弱于preD组和posD组(P<0.05)。结论右美托咪定预处理联合后处理较单纯的预处理或单纯的后处理能更有效地抑制炎症因子的产生和释放,具有更好的心肌保护功能。

Distributions of crystals and gas bubbles in reservoir ice during growth period

In order to understand the dominant factors of the physical properties of ice in ice thermodynamics and mechanics, in-situ observations of ice growth and decay processes were carried out. Two samplings were conducted in the fast and steady ice growth stages. Ice pieces were used to observe ice crystals and gas bubbles in ice, and to measure the ice density. Vertical profiles of the type and size of ice crystals, shape and size of gas bubbles, and gas bubble content, as well as the ice density, were obtained. The results show that the upper layer of the ice pieces is granular ice and the lower layer is columnar ice; the average crystal size increases with the ice depth and remains steady in the fast and steady ice growth stages; the shape of gas bubbles in the upper layer of ice pieces is spherical with higher total content, and the shape in the middle and lower layers is cylinder with lower total content; the gas bubble size and content vary with the ice growth stage; and the ice density decreases with the increase of the gas bubble content.

XAFS and SRGI-XRD studies of the local structure of tellurium corrosion of Ni–18%Cr alloy

The speciation and atomic structures of corrosion products in Ni-based alloys could provide basic information for understanding the Te corrosion mechanism.In this paper,two-dimensional synchrotron-radiation-induced grazing incidence X-ray diffraction was used to characterize the corrosion products of a Ni–18%Cr binary alloy at temperatures from 600 to 1000℃.The results showed that a film of CrTe is preferentially formed when Te reacts with the Ni-based alloy at low temperatures(below 900℃),while CrTe and Ni3Te2 are formed at 900℃.Moreover,at a temperature of 1000℃,a solid solution is formed without any changes in the Ni–Cr substrate lattice parameters.Furthermore,X-ray absorption fine structure and wavelet transform analyses were used to investigate the atomic local structure of Te.The investigation indicated that Te atoms diffuse into the Ni–Cr substrate to form a substitutional Ni–Cr–Te solid solution at 1000℃.Notably,based on a discussion of the thermodynamics of the chemical reaction process,CrTe is considered to be the most stable and prevalent corrosion product due to its comparatively lower Gibbs free energy of formation.These results demonstrate that the Ni–18%Cr alloy is capable of resisting the diffusion of Te atoms.

重复肾输尿管畸形合并上尿路结石的腔内外科治疗体会

目的探讨重复肾输尿管畸形合并上尿路结石的腔内外科治疗方法和效果。方法回顾性分析26例腔内外科治疗的重复肾输尿管畸形合并上尿路结石患者的临床资料。结果应用输尿管硬镜碎石取石术(URL)治疗5例,输尿管软镜钬激光碎石术(RIRS)治疗15例,微创经皮肾镜碎石取石术(m PCNL)治疗6例。所有患者均成功完成手术,无感染性休克、大出血、输尿管损伤和气胸等严重并发症。23例获得随访的患者,随访2~24个月,未出现输尿管狭窄病变,肾积水均有不同程度的减轻。结论腔内外科技术治疗重复肾输尿管畸形合并上尿路结石具有创伤小、恢复快和安全性高等优点。

Fault Tolerant Control for Networked Control Systems with Packet Loss and Time Delay

In this paper,a fault tolerant control with the consideration of actuator fault for a networked control system （NCS） with packet loss is addressed.The NCS with data packet loss can be described as a switched system model.Packet loss dependent Lyapunov function is used and a fault tolerant controller is proposed respectively for arbitrary packet loss process and Markovian packet loss process.Considering a controlled plant with external energy-bounded disturbance,a robust H ∞ fault tolerant controller is designed for the NCS.These results are also expanded to the NCS with packet loss and networked-induced delay.Numerical examples are given to illustrate the effectiveness of the proposed design method.

Absorption effect of pure nickel on the corrosion behaviors of the GH3535 alloy in tellurium vapor

In this study,pure Ni was demonstrated to protect the GH3535 alloy from Te vapor corrosion because of its strong absorption capacity.Severe Te corrosion of a single GH3535 alloy sample occurred in Te vapor at 700C,which manifested as complex surface corrosion products and deep intergranular cracks.However,when pure Ni and the GH3535 alloy were put together in the vessel,the GH3535 alloy was completely protected from Te corrosion at the expense of the pure Ni.Thermodynamic calculations proved that the preferential reaction between pure Ni and Te vapor reduced the activity of Te vapor considerably,preventing the corrosion of the GH3535 alloy.Our study reveals one potential approach for protecting the alloys used in molten-salt reactors from Te corrosion.

Effect of thermal exposure time on tellurium-induced embrittlement of Ni–16Mo–7Cr–4Fe alloy

The embrittlement of nickel-based structural alloys by fission-produced tellurium(Te) is a major challenge for molten salt reactors(MSR). In this study, the effects of thermal exposure time on tellurium diffusion in a candidate MSR structural alloy(Ni–16 Mo–7 Cr–4 Fe) and the consequent mechanical property degradation of the alloy were investigated through surrogate diffusion experiments at 700 °C. The results show that some tellurium reacted with the alloy to form tellurides on the surface,while some tellurium diffused into the alloy along grain boundaries. Ni_3Te_2 and CrTe were the most stable reaction products at the tested temperature, and the formation of CrTe on the surface induced the Cr depletion at grain boundaries of the alloy. The diffusion depth of Te increased gradually with thermal exposure time, and thediffusion rate kept stable within the test duration of up to3000 h. The Te diffusion in the alloy caused the embrittlement of grain boundaries, inducing crack formation and strength degradation in tensile test at room temperature.