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New medical risks affecting obstetrics after implementation of the two-child policy in China

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《医学前沿（英文）》 2017年 第11卷 第4期   页码 570-575 doi: 10.1007/s11684-017-0552-5

摘要：

China recently instituted a two-child policy in response to its aging population, declining workforce and demographic dividend, and the need to develop asocial economy. Additionally, women generally delay having a second child because of the overwhelming pressure in their lives. With the improvements in assisted fertility technologies in recent years, the number of elderly women attempting to bear children has increased. The quality of woman’s eggs and a man’s sperm declined dramatically with increasing age, leading to an increased risk of pregnancy-related complications among older women. Therefore, the types of fertility problems experienced by elderly females must be provided with considerable attention by obstetricians. This commentary article focuses on the medical problems faced by older second-child pregnant women. This work discusses their increased rates of infertility, spontaneous abortion, fetal malformation, gestational diabetes, cesarean section, placenta previa, postpartum hemorrhage, postpartum depression, and hypertensive disorders, which complicate pregnancy.

关键词： two-child policy     birth defects     cesarean delivery     placenta previa    

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连云港市病残儿童资料分析及孕前优生干预其父母再生育效果研究

赵玉凤,谢炜,裴丹,王其军,张立华,段玉秋,李 琴,刘艳丽,王 英

《中国工程科学》 2015年 第17卷 第6期   页码 36-40

摘要：

目的：分析连云港市病残儿童资料，通过孕前优生健康检查干预其近五年病残儿父母再生育，预防病残儿的发生风险。方法：对连云港市2008―2012年经过医学鉴定的病残儿的资料进行分析，比较其五年间数量、地区、性别分布、疾病顺位变化等，发放调查问卷了解其在生育病残儿之前的基本情况；再次怀孕后有无优生指导、超生排畸、唐筛、妊娠结局、分娩方式等调查，分析干预效果。结果：近五年通过医学鉴定符合病残儿童标准的1 046例五年间无明显变化；城区较农村多；男性较女性多；疾病顺位排序先天性心脏病位于第一位。通过干预，收回问卷中先天性心脏病父母再生育72例均为正常儿，其次脑瘫患儿父母再生育35例均为正常儿。结论：病残儿鉴定父母通过孕前优生健康检查，完成整个孕前保健、风险评估到个性化咨询指导一系列干预后再生育均为正常儿，干预效果明显，减少了不良妊娠结局的发生，对预防和降低再次生育病残儿的发生非常重要。

关键词： 病残儿；出生缺陷；孕前优生健康指导；再生育干预    

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乌鲁木齐市部分地区农牧民和流动人口孕前优生结果分析

于江,单湘婷,王军,谢金荣

《中国工程科学》 2014年 第16卷 第5期   页码 52-55

摘要：

为了解计划怀孕夫妇双方一般情况及健康状况，开展孕前健康教育及优生咨询指导工作，降低出生缺陷发生风险，本文对606 对符合生育政策、计划怀孕的农牧民和流动人口夫妇的孕前优生健康检查资料进行分析。实验结果表明：606 对夫妇男方吸烟人数为381 人，占男方受检总人数的62.87 %，女方被动吸烟的人数为324 人，占女方受检总人数的53.46 %；存在不良饮食习惯人数男女共计152 人；接触农药及新装修、油漆等人数男女共计228 人；女方检出疾病中以生殖系统炎症发病率最高。参检人员由于文化程度低，语言沟通障碍等因素，造成孕前优生知识缺乏，优生意识淡漠。因此，应根据孕前优生健康检查结果，为计划怀孕夫妇提供综合性指导，从而有效减少出生缺陷发生，提高人口素质。

关键词： 优生健康检查     风险因素     出生缺陷    

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Tomographic diagnosis of defects in hydraulic concrete structure

ZHAO Mingjie, XU Xibin

《结构与土木工程前沿（英文）》 2008年 第2卷 第3期   页码 226-232 doi: 10.1007/s11709-008-0027-5

摘要： The ultrasonic tomographic technology is applied to diagnose the defects in hydraulic concrete structure. In order to improve the precision of diagnoses, the wavelet transformation is used in the processing of ultrasonic signals. The influences of water, scale and orientation of defect, processing methods and theoretical model on image resolution are investigated. The experimental results indicate that the result of the tomographic diagnosis of a single defect is sensitive and the boundary can be clearly determined. However, the image resolution of multiple defects is not satisfactory. The water content and scale of a defect may significantly affect the imaging resolution. Defects with the orientation perpendicular to the direction of the diagnosis may have higher precision in diagnosing. The wavelet transformation technology can elevate the imaging resolution. The applied calculation model plays a very important role in improving the accuracy of detection.

关键词： satisfactory     processing     orientation     tomographic diagnosis     orientation perpendicular    

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Advancing pediatric care before birth

《医学前沿（英文）》 2023年 第17卷 第2期   页码 352-354 doi: 10.1007/s11684-022-0974-6

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Automated classification of civil structure defects based on convolutional neural network

Pierclaudio SAVINO, Francesco TONDOLO

《结构与土木工程前沿（英文）》 2021年 第15卷 第2期   页码 305-317 doi: 10.1007/s11709-021-0725-9

摘要： Today, the most commonly used civil infrastructure inspection method is based on a visual assessment conducted by certified inspectors following prescribed protocols. However, the increase in aggressive environmental and load conditions, coupled with the achievement of many structures of the life-cycle end, has highlighted the need to automate damage identification and satisfy the number of structures that need to be inspected. To overcome this challenge, this paper presents a method for automating concrete damage classification using a deep convolutional neural network. The convolutional neural network was designed after an experimental investigation of a wide number of pretrained networks, applying the transfer-learning technique. Training and validation were conducted using a database built with 1352 images balanced between “undamaged”, “cracked”, and “delaminated” concrete surfaces. To increase the network robustness compared to images in real-world situations, different image configurations have been collected from the Internet and on-field bridge inspections. The GoogLeNet model, with the highest validation accuracy of approximately 94%, was selected as the most suitable network for concrete damage classification. The results confirm that the proposed model can correctly classify images from real concrete surfaces of bridges, tunnels, and pavement, resulting in an effective alternative to the current visual inspection techniques.

关键词： concrete structure     infrastructures     visual inspection     convolutional neural network     artificial intelligence    

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“Charging” the cigarette butt: heteroatomic porous carbon nanosheets with edge-induced topological defects

《化学科学与工程前沿（英文）》 2023年 第17卷 第11期   页码 1755-1764 doi: 10.1007/s11705-023-2318-8

摘要： Owing to the complexity of electron transfer pathways, the sluggish oxygen evolution reaction process is defined as the bottleneck for the practical application of Zn–air batteries. In this effort, metal nanoparticles (Co, Ni, Fe, etc.) encapsulated within nitrogen-doped carbon materials with abundant edge sites were synthesized by one-step pyrolysis treatment using cigarette butts as raw materials, which can drastically accelerate the overall rate of oxygen evolution reaction by facilitating the adsorption of oxygenated intermediates by the edge-induced topological defects. The prepared catalyst of nitrogen-doped carbon porous nanosheets loaded with Co nanoparticles (Co@NC-500) exhibits enhanced catalytic activity toward oxygen evolution reaction, with a low overpotential of 350 mV at the current density of 10 mA·cm–2. Furthermore, the Zn–air battery assembled with Co@NC-500 catalyst demonstrates a desirable performance affording an open-circuit potential of 1.336 V and power density of 33.6 mW·cm–2, indicating considerable practical application potential.

关键词： oxygen evolution reaction     porous carbon nanosheets     Co nanoparticles     edge-induced topological defects     Zn–air batteries    

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Thermal reffusivity: uncovering phonon behavior, structural defects, and domain size

Yangsu XIE, Bowen ZHU, Jing LIU, Zaoli XU, Xinwei WANG

《能源前沿（英文）》 2018年 第12卷 第1期   页码 143-157 doi: 10.1007/s11708-018-0520-z

摘要： To understand the relation between different nanostructures and thermal properties, a simple yet effective model is in demand for characterizing the underlying phonons and electrons scattering mechanisms. Herein, we make a systematic review on the newly developed thermal reffusivity theory. Like electrical resistivity which has been historically used as a theory for analyzing structural domain size and defect levels of metals, the thermal reffusivity can also uncover phonon behavior, structure defects and domain size of materials. We highlight that this new theory can be used for not only metals, but also nonmetals, even for amorphous materials. From the thermal reffusivity against temperature curves, the Debye temperature of the material and the ideal thermal diffusivity of single perfect crystal can be evaluated. From the residual thermal reffusivity at the 0 K limit, the structural thermal domain (STD) size of crystalline and amorphous materials can be obtained. The difference of white hair and normal black hair from heat conduction perspective is reported for the first time. Loss of melanin results in a worse thermal protection and a larger STD size in the white hair. By reviewing the different variation of thermal reffusivity against decreasing temperature profiles, we conclude that they reflected the structural connection in the materials. Ultimately, the future application of thermal reffusivity theory in studying 2D materials and amorphous materials is discussed.

关键词： thermal reffusivity theory     phonon behavior     structure defects     structural thermal domain (STD) size     2D material     amorphous material    

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Determining casting defects in near-net shape casting aluminum parts by computed tomography

Jiehua LI, Bernd OBERDORFER, Daniel HABE, Peter SCHUMACHER

《机械工程前沿（英文）》 2018年 第13卷 第1期   页码 48-52 doi: 10.1007/s11465-018-0493-y

摘要：

Three types of near-net shape casting aluminum parts were investigated by computed tomography to determine casting defects and evaluate quality. The first, second, and third parts were produced by low-pressure die casting (Al-12Si-0.8Cu-0.5Fe-0.9Mg-0.7Ni-0.2Zn alloy), die casting (A356, Al-7Si-0.3Mg), and semi-solid casting (A356, Al-7Si-0.3Mg), respectively. Unlike die casting (second part), low-pressure die casting (first part) significantly reduced the formation of casting defects (i.e., porosity) due to its smooth filling and solidification under pressure. No significant casting defect was observed in the third part, and this absence of defects indicates that semi-solid casting could produce high-quality near-net shape casting aluminum parts. Moreover, casting defects were mostly distributed along the eutectic grain boundaries. This finding reveals that refinement of eutectic grains is necessary to optimize the distribution of casting defects and reduce their size. This investigation demonstrated that computed tomography is an efficient method to determine casting defects in near-net shape casting aluminum parts.

关键词： near-net shape casting     aluminum parts     casting defects     low pressure die casting     die casting     semi-solid casting     computed tomography    

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Detection of solder bump defects on a flip chip using vibration analysis

Junchao LIU, Tielin SHI, Qi XIA, Guanglan LIAO

《机械工程前沿（英文）》 2012年 第7卷 第1期   页码 29-37 doi: 10.1007/s11465-012-0314-7

摘要：

Flip chips are widely used in microelectronics packaging owing to the high demand of integration in IC fabrication. Solder bump defects on flip chips are difficult to detect, because the solder bumps are obscured by the chip and substrate. In this paper a nondestructive detection method combining ultrasonic excitation with vibration analysis is presented for detecting missing solder bumps, which is a typical defect in flip chip packaging. The flip chip analytical model is revised by considering the influence of spring mass on mechanical energy of the system. This revised model is then applied to estimate the flip chip resonance frequencies. We use an integrated signal generator and power amplifier together with an air-coupled ultrasonic transducer to excite the flip chips. The vibrations are measured by a laser scanning vibrometer to detect the resonance frequencies. A sensitivity coefficient is proposed to select the sensitive resonance frequency order for defect detection. Finite element simulation is also implemented for further investigation. The results of analytical computation, experiment, and simulation prove the efficacy of the revised flip chip analytical model and verify the effectiveness of this detection method. Therefore, it may provide a guide for the improvement and innovation of the flip chip on-line inspection systems.

关键词： flip chip     defect detection     ultrasonic excitation     vibration analysis    

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Diagnosis of sewer pipe defects on image recognition of multi-features and support vector machine in

Xiangyang Ye, Jian’e Zuo, Ruohan Li, Yajiao Wang, Lili Gan, Zhonghan Yu, Xiaoqing Hu

《环境科学与工程前沿（英文）》 2019年 第13卷 第2期 doi: 10.1007/s11783-019-1102-y

摘要：

An image-recognition-based diagnosis system of pipe defect types was established.

1043 practical pipe images were gathered by CCTV robot in a southern Chinese city.

The overall accuracy of the system is 84% and the highest accuracy is 99.3%.

The accuracy shows positive correlation to the number of training samples.

关键词： Sewer pipe defects     Defect diagnosing     Image recognition     Multi-features extraction     Support vector machine    

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Tuning nitrogen defects and doping sulfur in carbon nitride for enhanced visible light photocatalytic

《化学科学与工程前沿（英文）》 2023年 第17卷 第1期   页码 93-101 doi: 10.1007/s11705-022-2175-x

摘要： Defect construction and heteroatom doping are effective strategies for improving photocatalytic activity of carbon nitride (g-C3N4). In this work, N defects were successfully prepared via cold plasma. High-energy electrons generated by plasma can produce N defects and embed sulfur atoms into g-C3N4. The N defects obviously promoted photocatalytic degradation performance that was 7.5 times higher than that of pure g-C3N4. The concentration of N defects can be tuned by different power and time of plasma. With the increase in N defects, the photocatalytic activity showed a volcanic trend. The g-C3N4 with moderate concentration of N defects exhibited the highest photocatalytic activity. S-doped g-C3N4 exhibited 11.25 times higher photocatalytic activity than pure g-C3N4. It provided extra active sites for photocatalytic reaction and improved stability of N defects. The N vacancy-enriched and S-doped g-C3N4 are beneficial for widening absorption edge and improving the separation efficiency of electron and holes.

关键词： g-C3N4     nitrogen defect     sulfur doping     photodegradation     plasma    

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Loss of liver kinase B1 causes planar polarity defects in cochlear hair cells in mice

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《医学前沿（英文）》 2016年 第10卷 第4期   页码 481-489 doi: 10.1007/s11684-016-0494-3

摘要：

The tumor suppressor gene liver kinase B1 (LKB1), also called STK11, encodes a serine/threonine kinase. LKB1 plays crucial roles in cell differentiation, proliferation, and polarity. In this study, LKB1 conditional knockout mice (LKB1Pax2 CKO mice) were generated using Pax2-Cre mice to investigate the function of LKB1 in inner ear hair cells during early embryonic period. LKB1Pax2 CKO mice died perinatally. Immunofluorescence and scanning electron microscopy revealed that stereociliary bundles in LKB1Pax2 CKO mice were clustered and misoriented, respectively. Moreover, ectopic distribution of kinocilium bundles resulting from abnormal migration of kinocilium was observed in the mutant mice. The orientation of stereociliary bundles and the migration of kinocilia are critical indicators of planar cell polarity (PCP) of hair cells. LKB1 deficiency in LKB1Pax2 CKO mice thus disrupted hair cell planar polarity during embryonic development. Our results suggest that LKB1 is required in PCP formation in cochlear hair cells in mice.

关键词： LKB1     stereociliary bundles     kinocilium     planar cell polarity     hearing     mice    

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Comparison of birth weight and umbilical and placental characteristics of cloned and artificial insemination-derived

Zheng AO, Chengfa ZHAO, Yanmin GAN, Xiao WU, Junsong SHI, Enqin ZHENG, Dewu LIU, Gengyuan CAI, Zhenfang WU, Zicong LI

《农业科学与工程前沿（英文）》 2019年 第6卷 第1期   页码 54-60 doi: 10.15302/J-FASE-2018249

摘要：

Somatic cell nuclear transfer (SCNT)-derived piglets have significantly higher stillbirth rate and postnatal mortality rate than artificial insemination (AI)-generated piglets. The question whether the low survival rate of SCNT piglets was related to birth weight, umbilical cord or placenta development was investigated. In this study, stillbirth rate, neonatal death rate, birth weight, umbilical cord status, placental parameters and placental gene expression patterns were compared between SCNT and AI piglets. Results showed that mortality rates at birth and during the neonatal stage of SCNT piglets were significantly higher than those of AI piglets. The incidence of abnormal umbilical cord in SCNT and SCNT-liveborn (SCNT-LB) piglets was significantly higher than in AI and AI-liveborn (AI-LB) piglets. Birth weight, placental weight, placental surface area and placental efficiency in SCNT and SCNT-LB piglets were significantly lower than those of AI and AI-LB piglets. Placental expression profiles of imprinting, angiopoiesis and nutrient transport-related genes were defective in SCNT-LB piglets compared with those in AI-LB piglets. Thus, the low survival rate of SCNT piglets may be associated with abnormal umbilical cord and placenta development. These characteristics may have resulted from aberrant expression of angiogenesis, nutrient transport, and imprinting-related genes in the placentas.

关键词： cloned     pig     death     placenta     SCNT     umbilical cord    

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Highly uniform Ni particles with phosphorus and adjacent defects catalyze 1,5-dinitronaphthalene hydrogenation

Wei Xiong, Susu Zhou, Zeyong Zhao, Fang Hao, Zhihui Cai, Pingle Liu, Hailiang Zhang, Hean Luo

《化学科学与工程前沿（英文）》 2021年 第15卷 第4期   页码 998-1007 doi: 10.1007/s11705-020-1994-x

摘要： This work proposes a modified activated carbon support, with defects and heteroatoms (N,P-ACs) by nitrogen and phosphorus doping to load non-noble nickel to catalyze aromatic compound hydrogenation. The Ni/N,P-ACs-900 (prepared at 900 °C) showed promising catalytic activity in liquid-phase 1,5-dinitronaphthalene hydrogenation with a 1,5-diaminonaphthalene yield of 95.8% under the mild condition of 100 °C, which is comparable to the commercial Pd/C catalyst. The nitrogen species were burned off at 900 °C, causing more defects for nickel metal loading, facilitating the interaction between the supports and the nickel metal, and resulting in highly dispersed metal particles. The computational study of the nickel binding energy has been conducted using density functional theory. It exhibits that the defects formed by heteroatom doping are beneficial to nickel anchoring and deposition to form highly uniform nickel particles. The phosphorus species in combination with the defects are suitable for H adsorption and dissociation. These results reveal that the heteroatomic doping on the active carbon shows significant effects in the hydrogenation of the liquid-phase aromatic compounds. These findings could provide a promising route for the rational design of aromatic compound hydrogenation catalysts to significantly decrease the cost by instead using noble metal catalysts in the industry.

关键词： nitrogen and phosphorus doping     non-noble nickel catalyst     aromatic compounds hydrogenation    

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标题 作者 时间 类型 操作

New medical risks affecting obstetrics after implementation of the two-child policy in China

null

期刊论文

连云港市病残儿童资料分析及孕前优生干预其父母再生育效果研究

赵玉凤,谢炜,裴丹,王其军,张立华,段玉秋,李 琴,刘艳丽,王 英

期刊论文

乌鲁木齐市部分地区农牧民和流动人口孕前优生结果分析

于江,单湘婷,王军,谢金荣

期刊论文

Tomographic diagnosis of defects in hydraulic concrete structure

ZHAO Mingjie, XU Xibin

期刊论文

Advancing pediatric care before birth

期刊论文

Automated classification of civil structure defects based on convolutional neural network

Pierclaudio SAVINO, Francesco TONDOLO

期刊论文

“Charging” the cigarette butt: heteroatomic porous carbon nanosheets with edge-induced topological defects

期刊论文

Thermal reffusivity: uncovering phonon behavior, structural defects, and domain size

Yangsu XIE, Bowen ZHU, Jing LIU, Zaoli XU, Xinwei WANG

期刊论文

Determining casting defects in near-net shape casting aluminum parts by computed tomography

Jiehua LI, Bernd OBERDORFER, Daniel HABE, Peter SCHUMACHER

期刊论文

Detection of solder bump defects on a flip chip using vibration analysis

Junchao LIU, Tielin SHI, Qi XIA, Guanglan LIAO

期刊论文

Diagnosis of sewer pipe defects on image recognition of multi-features and support vector machine in

Xiangyang Ye, Jian’e Zuo, Ruohan Li, Yajiao Wang, Lili Gan, Zhonghan Yu, Xiaoqing Hu

期刊论文

Tuning nitrogen defects and doping sulfur in carbon nitride for enhanced visible light photocatalytic

期刊论文

Loss of liver kinase B1 causes planar polarity defects in cochlear hair cells in mice

null

期刊论文

Comparison of birth weight and umbilical and placental characteristics of cloned and artificial insemination-derived

Zheng AO, Chengfa ZHAO, Yanmin GAN, Xiao WU, Junsong SHI, Enqin ZHENG, Dewu LIU, Gengyuan CAI, Zhenfang WU, Zicong LI

期刊论文

Highly uniform Ni particles with phosphorus and adjacent defects catalyze 1,5-dinitronaphthalene hydrogenation

Wei Xiong, Susu Zhou, Zeyong Zhao, Fang Hao, Zhihui Cai, Pingle Liu, Hailiang Zhang, Hean Luo

期刊论文