Optimization Mechanism of Mechanical Properties of Basalt Fiber-Epoxy Resin Composites by Interfacially Enriched Distribution of Nano-Starch Crystals

Fibre reinforced polymer composites have become a new generation of structural materials due to their unique advantages such as high specific strength,designability,good dimensional stability and ease of large-area monolithic forming.However,the problem of interfacial bonding between the resin matrix and the fibres limits the direct use of reinforcing fibres and has become a central difficulty in the development of basalt fibre-epoxy composites.This paper proposes a solution for enhancing the strength of the fibre-resin interface using maize starch nanocrystals,which are highly yield and eco-friendly.Firstly,in this paper,corn starch nanocrystals(SNC)were prepared by hydrolysis,and were deposited on the surface of basalt fibers by electrostatic adsorption.After that,in order to maximize the modification effect of nano-starch crystals on the interface,the basalt fiber-epoxy resin composite samples were prepared by mixing in a pressureless molding method.The test results shown that the addition of basalt fibers alone led to a reduction in the strength of the sample.Deposition of 0.1 wt%SNC on the surface of basalt fibers can make the strength consistent with pure epoxy resin.When the adsorption amount of SNC reached 0.5 wt%,the tensile strength of the samples was 23.7%higher than that of pure epoxy resin.This is due to the formation of ether bond homopolymers between the SNC at the fibre-epoxy interface and the epoxy resin,which distorts the originally smooth interface,leading to increased stress concentration and the development of cracks.This enhances the binding of basalt fibers.The conclusions of this paper can provide an effective,simple,low-cost and non-polluting method of interfacial enhancement modification.

Towards adaptable synchrotron image restoration pipeline

Synchrotron microscopic data commonly suffer from poor image quality with degraded resolution incurred by instrumentation defects or experimental conditions.Image restoration methods are often applied to recover the reduced resolution,providing improved image details that can greatly facilitate scientific discovery.Among these methods,deconvolution techniques are straightforward,yet either require known prior information or struggle to tackle large experimental data.Deep learning(DL)-based super-resolution(SR)methods handle large data well,however data scarcity and model generalizability are problematic.In addition,current image restoration methods are mostly offline and inefficient for many beamlines where high data volumes and data complexity issues are encountered.To overcome these limitations,an online image-restoration pipeline that adaptably selects suitable algorithms and models from a method repertoire is promising.In this study,using both deconvolution and pretrained DL-based SR models,we show that different restoration efficacies can be achieved on different types of synchrotron experimental data.We describe the necessity,feasibility,and significance of constructing such an image-restoration pipeline for future synchrotron experiments.

Performance optimization of the neutron-sensitive image intensifier used in neutron imaging

As a non-destructive testing technology,neutron imaging plays an important role in various fields,including material science,nuclear engineering,and fundamental science.An imaging detector with a neutron-sensitive image intensifier has been developed and demonstrated to achieve good spatial resolution and timing resolution.However,the influence of the working voltage on the performance of the neutron-sensitive imaging intensifier has not been studied.To optimize the performance of the neutron-sensitive image intensifier at different voltages,experiments have been performed at the China Spallation Neutron Source(CSNS)neutron beamline.The change in the light yield and imaging quality with different voltages has been acquired.It is shown that the image quality benefits from the high gain of the microchannel plate(MCP)and the high accelerating electric field between the MCP and the screen.Increasing the accelerating electric field is more effective than increasing the gain of MCPs for the improvement of the imaging quality.Increasing the total gain of the MCP stack can be realized more effectively by improving the gain of the standard MCP than that of the n MCP.These results offer a development direction for image intensifiers in the future.

Large area^(3)He tube array detector with modular design for multi‑physics instrument at CSNS

The multi-physics instrument(MPI)is the first user cooperative instrument at the China Spallation Neutron Source(CSNS).It was designed to explore the structures of complex materials at multiple scales based on the neutron total scattering technique.This imposes the requirements for the detector,including a high detection efficiency to reduce the measurement time and a large solid angle coverage to cover a wide range of momentum transfers.To satisfy these demands,a large-area array of 3He-filled linear position-sensitive detectors(LPSDs)was constructed,each with a diameter of 1 inch and pressure of 20 atm.It uses an orbicular layout of the detector and an eight-pack module design for the arrangement of 3He LPSDs,covering a range of scattering angles from 3°to 170°with a total detector area of approximately 7 m2.The detector works in air,which is separated from the vacuum environment to facilitate installation and maintenance.The characteristics of the MPI detector were investigated through Monte Carlo(MC)simulations using Geant4 and experimental measurements.The results suggest that the detectors are highly efficient in the wavelength range of the MPI,and an efficiency over 25%is achievable for above 0.1 A neutrons.A minimal position resolution of 6.4 mm full width at half maximum(FWHM)along the tube length was achieved at a working voltage of 2200 V,and a deviation below 2 mm between the real and measured positions was attained in the beam experiment.The detector module exhibited good consistency and an excellent counting rate capacity of up to 80 kHz,which satisfied the requirements of experiments with a high event rate.Observations of its operation over the past year have shown that the detector works steadily in sample experiments,which allows the MPI to serve the user program successfully.

Maternal Vascular Dysfunction in Congenital Heart Defects

Background:Research on fetal congenital heart defect(CHD)mostly focuses on etiology and mechanisms.However,studies on maternal complications or pathophysiology are limited.Our objective was to determine whether vascular dysfunction exists in pregnant women carrying a fetus with congenital heart defects.Methods:We conducted a case-control study.27 cases of pregnant women carrying a fetus with major CHD admitted to our hospital for delivery between April 2021 and August 2022 were selected.Every case was matched with about 2 pregnant complication-free controls without fetal abnormalities.The proangiogenic and anti-angiogenic factors and pregnancy outcomes were compared.Results:The proangiogenic factors include vascular endothelial growth factor(VEGF)and placental growth factor(PlGF).The anti-angiogenic factors involve soluble fms-like tyrosine kinase 1(sFlt-1)and soluble endoglin(sEng).No differences were found in maternal plasma concentrations of PlGF,VEGF,and sFlt-1 between case-control groups when analyzed at 36 weeks≤gestational age(GA)<39 weeks and 39 weeks≤GA≤41 weeks.The concentrations of sEng in maternal plasma in the fetal CHD group were significantly higher than those in the control group:0.60(0.77)vs.0.32(0.26)ng/ml at 36 weeks≤GA<39 weeks,p=0.001 and 0.75(0.55)vs.0.28(0.27)ng/ml at 39 weeks≤GA≤41 weeks,p<0.001.Conclusion:Vascular dysfunction exists in pregnant women with fetal congenital heart defects,manifesting significantly elevated sEng concentration at delivery.

基于交联透明质酸的微针制备及性能

新型水凝胶微针具有安全包裹多相药物、药物持续、可控释放等优点,在微针透皮给药领域极具应用潜力。文中重点研究了交联透明质酸微针贴片的优化工艺,并对微针贴片进行了性能评价。在碱性条件下使用1,4-丁二醇二缩水甘油醚(BDDE)为交联剂对透明质酸进行交联,利用微浇注法制备交联透明质酸微针(cHA-MN),并优化其工艺。对所制备的微针贴片进行了外观形貌、力学性能、体外刺入性能及溶胀性能表征,验证其能否满足使用要求。实验结果表明,使用最优工艺制备的交联透明质酸微针贴片力学性能优良,可以顺利刺破皮肤,并实现溶胀功能。使用制备的微针搭载2.5%的右旋布洛芬药物,体外透皮扩散结果表明,微针在0~6 h释放出约38%药物,随后以一定速度缓慢释放至42 h,累计释放率约90%。

透皮给药实心微针阵列的紫外压印工艺方法

文中提出了一种紫外压印技术成型透皮给药实心微针的工艺方法,以C-coating光刻胶作为微针成型的原材料,采用微机电技术加工的聚二甲基硅氧烷(PDMS)微针模具,探究了紫外压印实验中影响微针成型质量的工艺条件。实验结果表明,利用C-coating光刻胶抽真空12 min以上,紫外曝光170~200 s时,制备的紫外压印微针的高度能达到230μm。通过纳米压痕力学测试和猪皮离体皮肤穿刺实验,证明这种紫外压印微针的针尖在承受50 mN的力时没有发生断裂破坏现象,并且能够顺利刺入猪皮达到良好的透皮给药效果,为紫外压印技术成型透皮给药微针提供了一定的技术参考。

Determination of Aromatic Components of Rosa davurica Pall. by Headspace Solid Phase Microextraction Combined with GC-MS

[Objectives] To determine the aromatic components of Rosa davurica Pall. [Methods] 42 kinds of aromatic components were identified from the flowers of R. davurica by headspace solid phase microextraction( HS-SPME) combined with gas chromatography-mass spectrometry( GC-MS). The main compounds were alcohols( 54. 88%) and aldehydes( 19. 55%). [Results] The top five components with the highest relative content were phenylethyl alcohol( 12. 69%),geraniol( 9. 85%),citronellol( 8. 80%),nerol( 7. 84%) and 2-n-pentylfuran( 7. 45%). [Conclusions] Headspace solid phase microextraction( HS-SPME) combined with gas chromatography-mass spectrometry( GC-MS) can provide basis for further development and utilization of R. davurica.

Prenatal congenital heart defects in southern China:detection rate and termination of preqnancy,2006-2016

Objective Congenital heart defect (CHD) is one of the most common birth anomalies with high morbidity and mortality. Previous studies of CHD mostly focus on the postnatal prevalence, mortality and successful rate of operation, etc. This study aimed to explore the detection rate of prenatal CHD and CHD factors that attribute to termination of pregnancy (TOP).

Screening Coarctation of Aorta with Clinical and Echocardiographic Profiles in Infants:A Pilot Study

Aim:To determine the profiles of clinical features including four-limb blood pressure(BP),saturations of peripheral oxygen(SpO2),and echocardiographic features in infants with coarctation of aorta(CoA)to facilitate congenital heart diseases screening.Methods:The charts of infants with CoA were retrospectively reviewed.All in-hospital infants suspected of congenital heart diseases by clinical teams were prospectively measured of four limbs BPs and SpO2 in a regional cardiac transferring center during 2013 and 2019.Echocardiography as a gold standard test was followed within 2 days after suspicion.All infants were divided into non-significant CoA group or significant CoA group based on the difference of BPs between right arm and lower limbs.Predictors of nonsignificant CoA were determined with multivariable logistic regression.Results:One hundred thirty-three infants with CoA were identified.The BPs on upper limbs were higher than those on lower limbs(P=0.001).No statistical difference in SpO2 was found between four limbs.Fifty-three(39.8%)infants presented with significant CoA.Thirty-four infants presented with low SpO2 and 26 of 34 presented with non-significant CoA.Small ascending aorta diameter[0.070(95%CI:0.005–0.136),P=0.036]was an independent risk factors for non-significant CoA.Eighteen(13.5%)infants with CoA didn’t present with any of the BP difference,low SpO2,murmur,or weak femoral pulse.Conclusion:Less than half of the infants with CoA presented with a significant BP difference.Another one fifth presented with low SpO2.Small ascending aorta diameter was an independent factor for non-significant CoA.

THE NMR CONFORMATIONAL STUDIES OF BACITRACIN A

Bacitracin consists of a mixture of several closely related polypeptide antibiotics produced from Bacillus licheniformis.The major component, Bacitracin A, is a cyclic dodecapeptide（Fig, 1）, which has strong bacteriocidal effect on the G+ bacteria. The bacteriocidal activity requires the presence of divalent cations such as Zn;, As we know, the biological function of ploypeptides and proteins are closely related to their three-dimensional structure. Bacitracin A is very important for the demonstration of the coordination site of metal and the relationship between

Effects of Different Seedling Raising Methods on Seedling Growth of Two Kinds of Fritillaria

[Objectives] To reveal the effects of film mulching and open ground seedling raising on the differences between Fritillaria przewalskii Maxim. and Fritillaria pallidiflora Schrenkf., find the optimal seedling raising method, and provide scientific basis for standard seedling raising technique and protecting wild resources of Fritillaria. [Methods] This experiment counted the seedling emergence number and calculated the seedling emergence indicator and the yield. [Results] The results showed that under the condition of film mulching and open ground seedling raising, the changes of Fritillaria seedlings showed an "S" curve, conforming to the Logistic equation, and the rapid growth period appeared 5-13 d after seedling emergence. Compared with the open ground seedling raising, the seedlings of F. przewalskii Maxim. and F. pallidiflora Schrenkf. raised through film mulching emerged 2-4 d earlier, and the yield increased by 56.8% and 21.71%, respectively, and the individual quality was excellent. [Conclusions] The film mulching of F. przewalskii Maxim. and F. pallidiflora Schrenkf. has great significance to protect the wild resources of Fritillaria in Eryin Mountain Area. It is recommended to adopt the film mulching method for Fritillaria seedling raising, to reduce the yield decline due to lodging, and adopt sun-shading net covering after sowing.

A Rare Case of Transcatheter Closure of Both Inlet and Outlet of a Left Coronary Artery-to-Left Ventricular Fistula with Giant Coronary Artery Aneurysm

A congenital coronary artery fistula(CCAF)combined with giant coronary aneurysm(CAA)is a rare congenital cardiac abnormality.We reported an 8-year-old patient who underwent transcatheter closure of both inlet and outlet of a proximal left coronary artery(LCA)-to-left ventricular(LV)fistula with CAA of 41 mm×28 mm in diameter,during which acute occlusion of left anterior descending coronary artery(LAD)occurred immediately after device implantation at the inlet of fistula.We managed to prevent the patient from major adverse cardiac events by conservative therapy with dual antiplatelet agents instead of surgical removal of the device.The patient recovered well and had been follow-up for 2 years with no late complications reported.

Optimizing strain response in lead-free(Bi_(0.5)Na_(0.5))TiO_(3)-BaTiO_(3)-NaNbO_(3)solid solutions via ferroelectric/(non-)ergodic relaxor phase boundary engineering

Lead-free bismuth sodium titanate(Bi_(0.5)Na_(0.5))TiO_(3)(BNT)and related solid solutions are potential piezoelectric materials for such applications as actuators and transducers if their excellent strain responses and piezoelectric properties can be optimized.In this work,a large strain response of 0.61%is achieved in lead-free(0.94-x%)(Bi_(0.5)Na_(0.5))TiO_(3)-0.06BaTiO_(3)-x%NaNbO_(3)(x=0 e6,BNT-6BT-xNN)ceramics with the composition of x=3.5 in a pseudo-cubic structure.Coexistence of ferroelectric(FE)and relaxor(RE)domain structures is observed in all the unpoled ceramics and the enhanced strain response is believed to be related to the evolution of the ergodic relaxor(ER)and non-ergodic(NR)states thanks to the substitution of antiferroelectric NN.BNT-6BT-3.5NN is a critical composition near the FE/NR/ER phase boundary close to room temperature(RT)and its high strain response arises from a synergistic combination of a reversible electric-field-induced phase transition and an active domain switching in the mixed NR/ER state.This work provides new insights into the dynamic interplay between mesoscopic domains and macroscopic electrical properties in the BNT-based piezoceramics.