Intermolecular Acid-Base-Pairs Containing Poly(p-Terphenyl-co-lsatin Piperidinium)for High Temperature Proton Exchange Membrane Fuel Cells

How to optimize and regulate the distribution of phosphoric acid in matrix,and pursuing the improved electrochemical performance and service lifetime of high temperature proton exchange membrane(HT-PEMs)fuel cell are significant challenges.Herein,bifunctional poly(p-terphenyl-co-isatin piperidinium)copolymer with tethered phosphonic acid(t-PA)and intrinsic tertiary amine base groups are firstly prepared and investigated as HT-PEMs.The distinctive architecture of the copolymer provides a well-designed platform for rapid proton transport.Protons not only transports through the hydrogen bond network formed by the adsorbed free phosphoric acid(f-PA)anchored by the tertiary amine base groups,but also rely upon the proton channel constructed by the ionic cluster formed by the t-PA aggregation.Thorough the design of the structure,the bifunctional copolymers with lower PA uptake level(<100%)display prominent proton conductivities and peak power densities(99 mS cm^(-1),812 mW cm^(-2)at 160℃),along with lower PA leaching and higher voltage stability,which is a top leading result in disclosed literature.The results demonstrate that the design of intermolecular acid-base-pairs can improve the proton conductivity without sacrificing the intrinsic chemical stability or mechanical property of the thin membrane,realizing win-win demands between the mechanical robustness and electrochemical properties of HT-PEMs.

Intracoronary thrombolysis combined with drug balloon angioplasty in a young ST-segment elevation myocardial infarction patient:A case report

BACKGROUND The combination of acute ST-segment elevation myocardial infarction(STEMI)and gastric ulcers poses a challenge to primary percutaneous coronary intervention(PPCI),particularly for young patients.The role of drug-coated balloons(DCBs)in the treatment of de novo coronary artery lesions in large vessels remains unclear,especially for patients with STEMI.Our strategy is to implement drug balloon angioplasty following the intracoronary administration of low-dose prourokinase and adequate pre-expansion.CASE SUMMARY A 54-year-old male patient presented to the emergency department due to chest pain on June 24,2019.Within the first 3 minutes of the initial assessment in the emergency room,the electrocardiogram(ECG)showed significant changes.There was atrial fibrillation with ST-segment elevation.Subsequently,atrial fibrillation terminated spontaneously and reverted to sinus rhythm.Soon after,the patient experienced syncope.The ECG revealed torsades de pointes ventricular tachycardia.A few seconds later,it returned to sinus rhythm.High-sensitivity tropon in I was normal.The diagnosis was acute STEMI.Emergency coronary angiography revealed subtotal occlusion with thrombus formation in the proximal segment of the left anterior descending artery.Considering the patient's age and history of peptic ulcer disease,after the intracoronary injection of prourokinase,percutaneous transluminal coronary angioplasty and cutting balloon angioplasty were conducted for thorough preconditioning,and paclitaxel drug-eluting balloon angioplasty was performed without any stents,achieving favorable outcomes.CONCLUSION A PPCI without stents may be a viable treatment strategy for select patients with STEMI,and further research is warranted.

The application of intelligent sensors in medical research:a review

The rapid advancement of biomedicine in the twenty-first century has been facilitated by the constant innovation in biomedical technology.The most crucial issue in the field of medicine is to use sensor technology to gather information from primitive organisms,particularly the human body.Design,development,and application of biomedical sensors in the study of clinical diseases’diagnosis and therapy have all been significantly aided by the advancement of medicine.The interest in creating sensors significantly increased in the 1960s.Chemical and biological sensors have been swiftly created in response to an urgent practical necessity,enabling the creation of selective sensors for the direct detection of diverse ions and compounds.The traditional large-size sensors are quickly turning into miniature sensors and are rapidly applied in biological and medical fields.Currently,wearable electronic blood pressure monitors,home blood glucose meters,and quick body surface digital thermometers are commonly used.The advent of a wide variety of medical-grade wearable sensors that will enable real-time biometric data tracking of a large range of physiological characteristics will likely be one of the most revolutionary,exciting,and difficult changes to come to medicine over the next several years.For possible uses in the entertainment,health monitoring,and medical care industries,high-performance flexible strain sensors connected to clothing or human skin are necessary.The use of sensors in the development of biomedical diagnostic tools and medical equipment will enhance human quality of life in the twenty-first century.This article will introduce the current medical sensor field related to sensors for physical quantities,sensors for chemical quantities,sensors for biological quantities such as electronic nose,electronic tongue,and their applications.

类器官在肿瘤中的研究现状及应用前景

类器官是由正常组织或肿瘤的特异性干细胞,在体外三维培养条件下,形成的三维体外细胞结构,具有自我组织形成类似于原始组织的"微型器官"的能力,能够较好地概括来源组织的特征和细胞异质性。类器官作为肿瘤研究的临床前模型,可用于药物筛选,预测患者对治疗的反应,为患者选择最合适的治疗方案。此外,还可对其进行基因修饰,用于肿瘤的发生发展和转移机制的研究。类器官这一新颖的构建技术,能够为个性化医疗提供指导,具有广泛的应用前景。本文就类器官在肿瘤发生发展的机制研究、药物筛选和临床治疗中的作用以及其在肿瘤微环境中的应用进行综述。

Trillium tschonoskii maxim extract attenuates abnormal Tau phosphorylation

Large-scale epidemiological studies have found that hyperhomocysteinemia is a powerful, independent risk factor for Alzheimer＇s disease. Trillium tschonoskii maxim is a traditional Chinese medicine that is used to promote memory. However, scientific understanding of its mechanism of action is limited. This report studied the potential neuroprotective effects of Trillium tschonoskii maxim extract against homocysteine-induced cognitive deficits. Rats were intravenously injected with homocysteine（400 μg/kg） for 14 days to induce a model of Alzheimer＇s disease. These rats were then intragastrically treated with Trillium tschonoskii maxim extract（0.125 or 0.25 g/kg） for 7 consecutive days. Open field test and Morris water maze test were conducted to measure spontaneous activity and learning and memory abilities. Western blot assay was used to detect the levels of Tau protein and other factors involved in Tau phosphorylation in the hippocampus. Immunohistochemical staining was used to examine Tau protein in the hippocampus. Golgi staining was applied to measure hippocampal dendritic spines. Our results demonstrated that homocysteine produced learning and memory deficits and increased levels of Tau phosphorylation, and diminished the activity of catalytic protein phosphatase 2A. The total number of hippocampal dendritic spines was also decreased. Trillium tschonoskii maxim extract treatment reversed the homocysteine-induced changes. The above results suggest that Trillium tschonoskii maxim extract can lessen homocysteine-induced abnormal Tau phosphorylation and improve cognitive deterioration such as that present in Alzheimer＇s disease.

Analysis of a Propeller Wake Flow Field Using Viscous Fluid Mechanics

The computational fluid dynamics （CFD） method is used to numerically simulate a propeller wake flow field in open water. A sub-domain hybrid mesh method was adopted in this paper. The computation domain was separated into two sub-domains, in which tetrahedral elements were used in the inner domain to match the complicated geometry of the propeller, while hexahedral elements were used in the outer domain. The mesh was locally refined on the propeller surface and near the wake flow field, and a size function was used to control the growth rate of the grid. Sections at different axial location were used to study the spatial evolution of the propeller wake in the region ranging from the disc to one propeller diameter （D） downstream. The numerical results show that the axial velocity fluctuates along the wake flow; radial velocity, which is closely related to vortices, attenuates strongly. The trailing vortices interact with the tip vortex at the blades＇ trailing edge and then separate. The strength of the vortex shrinks rapidly, and the radius decreases 20% at one diameter downstream.

Thermodynamic analysis for separation of vanadium and chromium in V(Ⅳ)-Cr(Ⅲ)-H_2O system

To recycle vanadium and chromium from the V?Cr-bearing reducing slag,the thermodynamics of separating V(IV)and Cr(III)at 298 K was summarized in the form of potential-pH diagram and activity-pH diagram.The potential-pH diagrams of V-Mn-H2O and Cr-Mn-H2O systems show that the electrode potential of MnO2/Mn2+is higher than that of VO2+/VO2+but lower than that of Cr2O7 2-/Cr3+,which proves that it is feasible to selectively oxidize low valent vanadium using MnO2.The activity-pH diagrams of V(V)-H2O and Cr(III)-H2O systems show that the precipitation pH of V(V)is far lower than that of Cr(III),and therefore V(V)and Cr(III)can be separated through precipitation method.Based on the thermodynamic analysis,the flowsheet of recovery of vanadium and chromium from the V-Cr-bearing reducing slag is designed.

New design for multi-crystal data collection at SSRF

Data collection with microcrystals at synchrotron radiation facilities is challenging because it is difficult to harvest and locate microcrystals. Moreover,microcrystals are sensitive to radiation damage; thus, typically, a complete data set cannot be obtained with a single microcrystal. Herein, we report a new method for data collection with multiple microcrystals having a crystal size ranging from 1 to 30 lm. This method is suitable for not only low-temperature(100 K) data collection but also room-temperature data collection. Thin Kapton membranes were used to capture multiple crystals simultaneously. The microcrystals were visible under an optical microscope and easily located because the membrane was transparent and sufficiently thin. The film was fixed to a bracket that was prepared using a three-dimensional printer. The bracket was fixed on a magnetic base via screwing and employed by the goniometer system for data collection. Multiple data sets of fatty acid-binding protein 4(FABP4) and lysozyme microcrystals were collected using this novel designed device. Finally, the structures of protein FABP4 and lysozyme were obtained from these data via the molecule replacement method. The data statistics reveal that this method provides a comparable result to traditional methods such as a nylon loop.

Femtosecond laser fabrication of nanograting-based distributed fiber sensors for extreme environmental applications

The femtosecond laser has emerged as a powerful tool for micro-and nanoscale device fabrication. Through nonlinear ionization processes, nanometer-sized material modifications can be inscribed in transparent materials for device fabrication. This paper describes femtosecond precision inscription of nanograting in silica fiber cores to form both distributed and point fiber sensors for sensing applications in extreme environmental conditions. Through the use of scanning electron microscope imaging and laser processing optimization,high-temperature stable, Type II femtosecond laser modifications were continuously inscribed,point by point, with only an insertion loss at 1 d B m~(-1) or 0.001 d B per point sensor device.High-temperature performance of fiber sensors was tested at 1000℃, which showed a temperature fluctuation of ±5.5℃ over 5 days. The low laser-induced insertion loss in optical fibers enabled the fabrication of a 1.4 m, radiation-resilient distributed fiber sensor. The in-pile testing of the distributed fiber sensor further showed that fiber sensors can execute stable and distributed temperature measurements in extreme radiation environments. Overall, this paper demonstrates that femtosecond-laser-fabricated fiber sensors are suitable measurement devices for applications in extreme environments.

注射不同剂量康柏西普联合PRP及EX-PRESS引流钉植入术治疗NVG的疗效对比

目的:评估玻璃体腔注射三种剂量康柏西普联合全视网膜光凝(PRP)后行EX-PRESS引流钉植入术治疗新生血管性青光眼(NVG)的有效性及安全性。方法:前瞻性研究。收集我院2018-05/2020-09收治的NVG患者37例37眼,均接受玻璃体腔注射康柏西普3~5d后行PRP。术后1wk内接受EX-PRESS青光眼引流钉植入术。采用随机数字表法,将术前玻璃体腔注射三种剂量康柏西普分为低剂量组(13眼)、常规剂量组(12眼)、高剂量组(12眼),分别玻璃体腔注射10mg/mL康柏西普0.03、0.05、0.08mL(含康柏西普0.3、0.5、0.8mg)。观察三组患者玻璃体腔注药后虹膜及房角新生血管(NV)消退情况,比较三组患者术后眼压(IOP)、最佳矫正视力(BCVA)、并发症。结果:所有患者均完成随访。三组患者玻璃体腔注射后3~5d,虹膜及房角NV消退眼数高剂量组明显高于低剂量组(χ^(2)=0.132,P=0.003)、常规剂量组(χ^(2)=0.154,P=0.015)。三组术后1、3、6mo时,BCVA、IOP均较术前有所改善。术后12mo低剂量组、常规剂量组、高剂量组的IOP分别为14.12±2.63、13.37±2.18、12.15±1.43mmHg,高剂量组IOP均低于低剂量组及常规剂量组(均P<0.05)。术后12mo高剂量组BCVA均优于低剂量组及常规剂量组(均P<0.05)。术后12mo并发症发生率三组之间均无差异(P>0.05)。结论:玻璃体腔注射0.8mg高剂量康柏西普联合PRP及EX-PRESS引流钉植入术治疗NVG临床效果尤为显著。

IDSH: An Improved Deep Supervised Hashing Method for Image Retrieval

Image retrieval has become more and more important because of the explosive growth of images on the Internet.Traditional image retrieval methods have limited image retrieval performance due to the poor image expression abhility of visual feature and high dimension of feature.Hashing is a widely-used method for Approximate Nearest Neighbor(ANN)search due to its rapidity and timeliness.Meanwhile,Convolutional Neural Networks(CNNs)have strong discriminative characteristics which are used for image classification.In this paper,we propose a CNN architecture based on improved deep supervised hashing(IDSH)method,by which the binary compact codes can be generated directly.The main contributions of this paper are as follows:first,we add a Batch Normalization(BN)layer before each activation layer to prevent the gradient from vanishing and improve the training speed;secondly,we use Divide-and-Encode Module to map image features to approximate hash codes;finally,we adopt center loss to optimize training.Extensive experimental results on four large-scale datasets:MNIST,CIFAR-10,NUS-WIDE and SVHN demonstrate the effectiveness of the proposed method compared with other state-of-the-art hashing methods.

Synthesis, characterization and in vivo evaluation of honokiol bisphosphate prodrugs protects against rats’ brain ischemia-reperfusion injury

Honokiol(HK)usage is greatly restricted by its poor aqueous solubility and limited oral bioavailability.We synthesized and characterized a novel phosphate prodrug of honokiol(HKP)for in vitro and in vivo use.HKP greatly enhanced the aqueous solubility of HK(127.54±15.53 mg/ml)and the stability in buffer solution was sufficient for intravenous administration.The enzymatic hydrolysis of HKP to HK was extremely rapid in vitro(T 1/2=8.9±2.11 s).Pharmacokinetics studies demonstrated that after intravenous administration of HKP(32 mg/kg),HKP was converted rapidly to HK with a time to reach the maximum plasma concentration of^5 min.The prodrug HKP achieved an improved T 1/2(7.97±1.30 h)and terminal volume of distribution(26.02±6.04 ml/kg)compared with direct injection of the equimolar parent drug(0.66±0.01 h)and(2.90±0.342 ml/kg),respectively.Furthermore,oral administration of HKP showed rapid and improved absorption compared with the parent drug.HKP was confirmed to maintain the bioactivity of the parent drug for ameliorating ischemia-reperfusion injury by decreasing brain infarction and improving neurologic function.Taken together,HKP is a potentially useful aqueous-soluble prodrug with improved pharmacokinetic properties which may merit further development as a potential drug candidate.

Charge transfer modification of inverted planar perovskite solar cells by NiO_(x)/Sr:NiO_(x)bilayer hole transport layer

Perovskite solar cells(PSCs) are the most promising commercial photoelectric conversion technology in the future.The planar p–i–n structure cells have advantages in negligible hysteresis, low temperature preparation and excellent stability.However, for inverted planar PSCs, the non-radiative recombination at the interface is an important reason that impedes the charge transfer and improvement of power conversion efficiency. Having a homogeneous, compact, and energy-levelmatched charge transport layer is the key to reducing non-radiative recombination. In our study, NiO_(x)/Sr:NiO_(x)bilayer hole transport layer(HTL) improves the holes transmission of NiO_(x)based HTL, reduces the recombination in the interface between perovskite and HTL layer and improves the device performance. The bilayer HTL enhances the hole transfer by forming a driving force of an electric field and further improves J_(sc). As a result, the device has a power conversion efficiency of 18.44%, a short circuit current density of 22.81 m A·cm^(-2) and a fill factor of 0.80. Compared to the pristine PSCs, there are certain improvements of optical parameters. This method provides a new idea for the future design of novel hole transport layers and the development of high-performance solar cells.

Robustness Evaluation of a Novel Proton Beam Geometry for Head and Neck Patients Treated with Pencil Beam Scanning Therapy

Background: To evaluate the robustness of head and neck treatment using proton pencil beam scanning (PBS) technique with respect to range uncertainty (RU) and setup errors (SE), and to establish a robust PBS planning strategy for future treatment. Methods and Materials: Ten consecutive patients were planned with a novel proton field geometry (combination of two posterior oblique fields and one anterior field with gradient dose match) using single-field uniform dose (SFUD) planning technique and the proton plans were dosimetrically compared to two coplanar arc VMAT plans. Robustness of the plans, with respect to range uncertainties (RU = ± 3% for proton) and setup errors (SE = 2.25 mm for proton and VMAT), in terms of deviations to target coverage (CTV D98%) and OAR doses (max/mean), were evaluated and compared for each patient under worst case scenarios. Results: Dosimetrically, PBS plans provided better sparing to larynx (p = 0.005), oral cavity (p < 0.001) and contralateral parotid (p = 0.004) when compared to VMAT. CTV D98% variations were higher from SE than from RU for proton plans (-1.1% ± 1.3 % vs -0.4% ± 0.7% for nodal CTV and -1.4% ± 1.2 vs -0.4% ± 0.5% % for boost CTV). Overall, the magnitudes of variation of CTV D98% to combined SE and RU were found to be similar to the impact of the SE on the VMAT plans (-1.6% ± 1.9% vs -1.7% ± 1.4% for nodal CTV and -1.9% ± 1.6% vs -1.3% ± 1.5% for boost CTV). Compared to VMAT, a larger range of relative dose deviations were found for OARs in proton plans, but safe doses were maintained for cord (41.8 ± 3.6 Gy for PBS and 41.7 ± 3.9 Gy for VMAT) and brainstem (35.2 ± 8.4 Gy for PBS and 36.2 ± 5.1 Gy for VMAT) in worst case scenarios. Conclusions: Compared to VMAT, proton plans containing three SFUD fields with superior-inferior gradient dose matching had improved sparing to larynx, contralateral parotid and oral cavity, while providing similar robustness of target coverage. Evaluation of OAR dose robustness showed higher sensitivities to uncertainties for proton plans, but safe dose levels were maintained for cord and brainstem.

Discussion on Effective Strategies for Improving Enterprise Operation and Management Abilities

In the current socialist market economy,if an enterprise wants to grow and develop,it must do all kinds of management for its enterprise,and the most important thing for strengthening management of enterprises is to strengthen their own operation and management abilities.Whether it is financial management,management of personnel efficiency,or management of talents,it is necessary to protect from the infrastructure,so as to fundamentally improve the economic benefits of the enterprise,and vice versa if社is not properly managed,it will affect the development of the enterprise.Therefore,improving the operation and management abilities of enterprises at present is an important factor to promote the economic development of enterprises.This paper analyzes the management problems of enterprises and the definition of enterprise operation and management abilities,and analyzes how enterprises can reform and innovate,thus strengthening the operation and management abilities and economic benefits of enterprises.

Construction and Application of Knowledge Graph for Quality and Safety Supervision of Transportation Engineering

Knowledge graph technology play a more and more important role in various fields of industry and academia.This paper firstly introduces the general framework of the knowledge graph construction,which includes three stages:information extraction,knowledge fusion and knowledge processing.In order to improve the efficiency of quality and safety supervision of transportation engineering construction,this paper constructs a knowledge graph by acquiring multi-sources heterogeneous data from supervision of transportation engineering quality and safety.It employs a bottom-up construction strategy and some natural language processing methods to solve the problems of the knowledge extraction for transportation engineering construction.We use the entity relation extraction method to extract the entity triples from the multi-sources heterogeneous data,and then employ knowledge inference to complete the edges in the constructed knowledge graph,finally perform quality evaluation to add the valid triples to the knowledge graph for updating.Subgraph matching technology is also exploited to retrieve the constructed knowledge graph for efficiently acquiring the useful knowledge about the quality and safety of transportation engineering projects.The results show that the constructed knowledge graph provides a practical and valuable tool for the quality and safety supervision of transportation engineering construction.

青海省公路运输气象灾害风险分析

本文介绍了影响青海省公路运输的主要气象灾害风险,并分析了各类气象灾害风险的特点及时空分布规律,对于更好应对和防御各种气象灾害风险,提高我省公路运输安全和效率提供参考依据。

2D编织C/SiC孔边致密化结构多尺度混合模型与拉伸性能

针对一种开孔2D编织C/SiC复合材料在化学气相浸渗过程中出现的孔边致密化结构,提出了一种表征孔边致密化结构的建模方法。考虑孔隙的随机分布,建立了纤维束尺度代表体积元模型,实现了2D编织C/SiC复合材料等效弹性模量的计算。在此基础上,建立了具有孔边致密化结构的2D编织C/SiC复合材料宏-细观组合模型。基于3D hashin失效准则与修正的Von Mises失效准则,建立了2D编织C/SiC复合材料的渐进损伤模型,模拟了其单轴拉伸应力-应变行为。通过与实验数据的对比分析,验证了模型的有效性。计算不同孔隙率、致密带半径以及孔径的开孔2D编织C/SiC复合材料拉伸强度并分析其影响规律。计算结果表明:随着孔隙率的增大,材料刚度与拉伸强度不断减小,当孔隙率从5%上升到20%时,抗拉强度降低26.05%;随着致密带半径的增加,材料刚度下降越缓慢,失效强度越大,当致密带半径从0 mm增大到0.75 mm时,抗拉强度提高14.17%;随着孔径增大,孔边应力集中效应增强,孔边损伤程度加剧,材料损伤越快,当孔径从0.5 mm增大到2 mm时,抗拉强度降低35.01%。

二氧化碳基聚碳酸酯多元醇及聚氨酯的合成与应用

二氧化碳(CO_(2))是一种来源丰富、价格低廉、无毒的可再生资源,以其为原料合成高附加值产品是二氧化碳固定领域备受关注的课题.其中,利用二氧化碳与环氧化物的共聚反应合成二氧化碳基聚碳酸酯多元醇,进而制备二氧化碳基聚氨酯材料,这一路线作为绿色高分子化学的重要组成部分,正成为符合国家碳中和目标的前沿热点.本文主要介绍了近年来二氧化碳基聚碳酸酯多元醇的合成方法,着重关注链转移剂存在下二氧化碳和环氧化物不朽聚合成聚碳酸酯多元醇的研究进展,从非均相催化剂、均相金属催化剂和均相非金属催化剂三个方面进行分类和综述,并比较了它们的优缺点.同时,重点探讨了二氧化碳基多元醇在环保型热塑性聚氨酯、水性聚氨酯、发泡材料等领域的广泛应用,并对其未来发展趋势进行了预测.

Stress sensitivity analysis for a wide-chord fan blade using an adjoint method

High-performance compressor design is best achieved with a good trade-off between aerodynamic and structural considerations,which requires efficient and accurate multidisciplinary design and optimization tools.As advanced compressors are defined with a large design space,their optimization is most efficiently achieved using a gradient-based approach,where the gradient can be computed using an adjoint method,at a cost nearly independent of the dimension of the design space.While the adjoint method has been widely used for aerodynamic shape optimization,its use for structural shape optimizations of compressor blades has not been as well studied.This paper discussed a discrete adjoint solver for structural sensitivity analysis developed within the opensource Computational Structural Mechanics(CSM)software CalculiX,and proposed an efficient stress sensitivity analysis method based on the Finite Element Method(FEM)using adjoint.The proposed method is applied to compute the stress sensitivity of a wide-chord fan blade in a highbypass-ratio engine.The accuracy of the adjoint-based stress sensitivity is verified against central finite differences.In terms of computational efficiency,the adjoint approach is about 4.5 times more efficient than the conventional approach using finite differences.This works marks an important step towards fluid-structural coupled adjoint optimization of wide-chord fan blades.