Objective To explore the relationship between human cytomegalovirus (HCMV) UL144 sequence variability and clinical disease. Methods HCMV UL144 open reading frame (ORF) was amplified by PCR assay in 72 lowpassage isola...Objective To explore the relationship between human cytomegalovirus (HCMV) UL144 sequence variability and clinical disease. Methods HCMV UL144 open reading frame (ORF) was amplified by PCR assay in 72 lowpassage isolates [65 con-genitally infective children and 7 healthy children who were HCMV-DNA positive by quantitative PCR (qPCR)]. All positive PCR products were analyzed by heteroduplex mobility assay and single-stranded conformation polymorphism (HMA-SSCP) and 32 of them were sequenced. Results Fifty-five patient isolates and five healthy children isolates were HCMV-UL144 positive by PCR. Sequencing and HMA-SSCP analysis showed that significant strain-specific variability was present in the UL144 ORF. Phylogenetic analysis indicated that the nucleotide sequences could be separated into 3 major genotypes. Comparing between UL144 se-quences and the corresponding symptoms showed that genotype 2 did not exist in megacolon isolates. And genotype 1 and 3 were the major types among microcephaly and jaundice isolates respectively. Conclusions HCMV-UL144 existed in most of low passage isolates and sequences were hypervariable. The UL144 ORF and its predicted product with the high level of sequence variability in different kinds of isolates suggest that UL144 ORF might play a role in HCMV infectivity and subsequent diseases.展开更多
Framed structures are usually infilled with masonry walls. They may cause a significant increase in both stiffness and strength, reducing the deformation demand and increasing the energy dissipation capacity of the sy...Framed structures are usually infilled with masonry walls. They may cause a significant increase in both stiffness and strength, reducing the deformation demand and increasing the energy dissipation capacity of the system. On the other hand, irregular arrangements of the masonry panels may lead to the concentration of damage in some regions, with negative effects; for example soft story mechanisms and shear failures in short columns. Therefore, the presence ofinfill walls should not be neglected, especially in regions of moderate and high seismicity. To this aim, simple models are available for solid infills walls, such as the diagonal no-tension strut model, while infilled frames with openings have not been adequately investigated. In this study, the effect of openings on the strength and stiffness of infilled frames is investigated by means of about 150 experimental and numerical tests. The main parameters involved are identified and a simple model to take into account the openings in the infills is developed and compared with other models proposed by different researchers. The model, which is based on the use of strength and stiffness reduction factors, takes into account the opening dimensions and presence of reinforcing elements around the opening. An example of an application of the proposed reduction factors is also presented.展开更多
Steel 20Mn23AlV is a type of high aluminum steel with a very low ladle free-opening rate. The aluminum composition of 20Mn23AlV ranges from 1.6% to 2.45% ,which is significantly higher than other types of steel. Accor...Steel 20Mn23AlV is a type of high aluminum steel with a very low ladle free-opening rate. The aluminum composition of 20Mn23AlV ranges from 1.6% to 2.45% ,which is significantly higher than other types of steel. According to the real condition of 40 t ladle in steel-making plant of Baosteel Special Steel Company, previous works show that the key factors affecting the ladle free-opening rate of high aluminum steel in continuous casting are：sand material, accessories baking, ladle nozzle cleaning, the process and amount of adding sand, and the rate of argon stirring during refining. Therefore, improving the ladle filler sand quality, baking all of the raw materials, controlling the addition of ladle filler sand, cleaning the ladle nozzle, and optimizing argon stirring during the refining process can resolve the problem of a low ladle free-opening rate of high aluminum steel caused by the long ladle time of liquid steel.展开更多
BACKGROUND Severe open tibia fractures are challenging to treat with a lack of published clear management strategies.Our aim was to provide an overview of the largest singlecenter experience in the literature,with min...BACKGROUND Severe open tibia fractures are challenging to treat with a lack of published clear management strategies.Our aim was to provide an overview of the largest singlecenter experience in the literature,with minimum 1-year follow-up,of adult type 3 open tibial shaft fractures at Cambridge University Hospitals(a United Kingdom major trauma center).We sought to define patient characteristics and our main outcome measures were infection,union and re-fracture.AIM To retrospectively define patient and injury characteristics,present our surgical methods and analyze our outcomes–namely infection,union and re-fracture rates.METHODS Consecutive series of 74 patients with 75 open tibial fractures treated between 2014 and 2020(26 classified as Gustilo-Anderson 3A,47 were 3B and two were 3C).Nine patients underwent intramedullary nailing(IMN),61 underwent Taylor spatial frame(TSF)fixation and 5 were treated with Masquelet technique(IMN and subsequent bone grafting).RESULTS Mean follow-up was 16 mo(IMN)and 25 mo(TSF).We had an infection rate of 6.7%(5),non-union rate of 4%(3)and re-fracture rate of 2.7%(2).Average time to union was 22 wk for IMN and 38.6 wk for TSF.Thirty-three cases had a bone defect with a mean of 5.4 cm(2-11).Patient age,sex,diabetes,smoking status or injury severity did not have a significant effect on union time with either fixation method.Our limb salvage rate was 98.7%.CONCLUSION Grade 1 to 3A injuries can effectively be treated with reamed or unreamed IMN.Grade 3B/C injuries are best treated by circular external fixators as they provide good,reproducible outcomes and allow large bone defects to be addressed via distraction osteogenesis.展开更多
Objective: To evaluate the effectiveness of the damage control, in emergency to treat the open tibial pilon fractures with Dolphix? External Fixator Frame(CITIEFFE?, Calderara di Reno, Bologna, Italy). Methods: From J...Objective: To evaluate the effectiveness of the damage control, in emergency to treat the open tibial pilon fractures with Dolphix? External Fixator Frame(CITIEFFE?, Calderara di Reno, Bologna, Italy). Methods: From January 2017 to August 2017, at the Department of Orthopedics and Traumatology of Vito Fazzi Hospital Lecce, we treated 23 open tibial pilon fractures with Dolphix? External Fixator Frame(CITIEFFE?, Calderara di Reno, Bologna, Italy). The evaluation criteria of the case series were: the time needed to assemble the external fixator;the time taked to treat the ankle associated lesions;the time of skin healing;the ankle alignment;the subjective/objective Ovadia and Beals score;and complications. The Endpoint assessment was set at the days of the definitive surgery. Results: The results in terms of alignment, biomechanical stability of the frame, healing of soft tissue, complications were as good as the objective and subjective results according Ovadia and Beals score. Conclusion:Pilon fractures are complex and often present complications;the damage control treatment, in emergency, with Dolphix? External Fixator Frame(CITIEFFE?, Calderara di Reno, Bologna, Italy) permits a stable osteotaxis with minimal soft tissue damage and permit the repair of muscles, blood vessels and nerves with a stable bone and the soft tissue healing with vaccum therapy.展开更多
The Xuyi Schmidt Telescope Photometric Survey of the Galactic Anti-center（XSTPS-GAC）is a photometric sky survey that covers nearly 6000 deg^2 towards the Galactic Anti-center（GAC） in the g,r,i bands. Half of its s...The Xuyi Schmidt Telescope Photometric Survey of the Galactic Anti-center（XSTPS-GAC）is a photometric sky survey that covers nearly 6000 deg^2 towards the Galactic Anti-center（GAC） in the g,r,i bands. Half of its survey field is located on the Galactic Anti-center disk,which makes XSTPSGAC highly suitable to search for new open clusters in the GAC region. In this paper,we report new open cluster candidates discovered in this survey,as well as properties of these open cluster candidates,such as age,distance and reddening,derived by isochrone fitting in the color-magnitude diagram（CMD）.These open cluster candidates are stellar density peaks detected in the star density maps by applying the method from Koposov et al. Each candidate is inspected in terms of its true color image composed from three XSTPS-GAC band images. Then its CMD is checked,in order to identify whether the central region stars have a clear isochrone-like trend differing from background stars. The parameters derived from isochrone fitting for these candidates are mainly based on three band photometry of XSTPS-GAC.Moreover,when these new candidates are able to be seen clearly in 2 MASS data,their parameters are also derived based on the 2 MASS（J-H,J） CMD. There are a total of 320 known open clusters rediscovered and 24 new open cluster candidates discovered in this work. Furthermore,the parameters of these new candidates,as well as another 11 previously known open clusters,are properly determined for the first time.展开更多
It has been found that there are marked errors in the value of valid opening size of heat-bonded nonwoven fabrics between theoretical calculations and engineering measurements. A new modified theoretical model is adva...It has been found that there are marked errors in the value of valid opening size of heat-bonded nonwoven fabrics between theoretical calculations and engineering measurements. A new modified theoretical model is advanced in this paper. The equivalent diameter of the pore of a fibre web is used to calculate the valid opening size instead of the maximum diameter of inscribed circle used, because the fibres in practical fibre webs are flexible elastomers with definite diameters and the pore of fibre web may produce deformation in screening teat and engineering usage. The results show that the theoretical calculations coincide well with the engineering measurements. This method offers a theoretical basis for computer simulation to the performance of filters of heatbonded nonwoven fabrics.展开更多
This paper presents a preliminary test of the k-th nearest neighbor distance （KNND） method for detecting nearby open clusters based on Gaia-DR1. We select 38 386 nearby stars （〈 100 pc） from the Gaia-DR1 catalog,...This paper presents a preliminary test of the k-th nearest neighbor distance （KNND） method for detecting nearby open clusters based on Gaia-DR1. We select 38 386 nearby stars （〈 100 pc） from the Gaia-DR1 catalog, and then use the KNND method to detect overdense regions in three-dimensional space. We find two overdense regions （the Hyades and Coma Berenices （Coma Ber） open clusters）, and obtain 57 reliable cluster members. Based on these cluster members, the distances to the Hyades and Coma Ber clusters are determined to be 46.0±0.2 and 83.5±0.3 pc, respectively. Our results demonstrate that the KNND method can be used to detect open clusters based on a large volume of astrometry data.展开更多
Open clusters are the basic building blocks that serve as a laboratory for the study of young stellar populations in the Milky Way.Variable stars in open clusters provide a unique way to accurately probe the internal ...Open clusters are the basic building blocks that serve as a laboratory for the study of young stellar populations in the Milky Way.Variable stars in open clusters provide a unique way to accurately probe the internal structure,temporal and dynamical evolutionary stages of individual stars and the host cluster.The most powerful tool for such studies is time-domain photometric observations.This paper follows the route of our previous work,concentrating on a photometric search for variable stars in NGC 884.The target cluster is the companion of NGC869,forming the well-known double cluster system that is gravitationally bound.From the observation run in 2016 November,a total of 9247 B-band CCD images and 8218Ⅴ-band CCD images were obtained.We detected a total of 15 stars with variability in visual brightness,including five Be stars,three eclipsing binaries,and seven of unknown types.Two new variable stars were discovered in this work.We also compared the variable star content of NGC 884 with its companion NGC 869.展开更多
目的探讨长散在核元件1读码框2基因(L1-ORF2)对GES-1细胞衰老的影响及分子调控机制。方法采用高糖诱导法构建GES-1细胞衰老模型,构建L1-ORF2 si RNA载体,脂质体法将其瞬时转染正常及衰老的GES-1细胞,转染48h后用细胞计数法绘制细胞生长...目的探讨长散在核元件1读码框2基因(L1-ORF2)对GES-1细胞衰老的影响及分子调控机制。方法采用高糖诱导法构建GES-1细胞衰老模型,构建L1-ORF2 si RNA载体,脂质体法将其瞬时转染正常及衰老的GES-1细胞,转染48h后用细胞计数法绘制细胞生长曲线,流式细胞仪分析细胞周期,β-半乳糖苷酶染色检测细胞衰老情况,Western blotting检测转染细胞中L1-ORF2、P53、P21蛋白表达水平。结果成功构建了稳定的GES-1细胞衰老模型及L1-ORF2si RNA载体。与转染了阴性对照载体的细胞相比,转染L1-ORF2 si RNA载体的正常及衰老GES-1细胞的L1-ORF2表达均下降(P<0.05)。与转染阴性对照载体的衰老GES-1细胞相比,转染L1-ORF2 si RNA载体的衰老GES-1细胞增殖速度变快(P<0.05),G0/G1期比例明显减少(34.2%vs 39.3%,P<0.05),β-半乳糖苷酶染色比例下降(56%vs 69%,P<0.05),而转染阴性对照载体和L1-ORF2 si RNA载体的正常GES-1细胞相比则无明显差异(P>0.05)。P53蛋白仅在衰老GES-1细胞中有表达,在正常GES-1细胞中无表达,而P21蛋白在正常和衰老的GES-1细胞中均有表达,且后者表达更高(P<0.05)。与转染阴性对照载体的细胞相比,转染L1-ORF2 si RNA载体的GES-1细胞P53、P21蛋白表达量明显下降(P<0.05)。结论L1-ORF2 si RNA载体可使正常及衰老的GES-1细胞中L1-ORF2表达下调,促进衰老GES-1细胞的生长和增殖,而对正常GES-1细胞无明显影响。P53、P21蛋白参与了L1-ORF2调控细胞衰老的过程。展开更多
基金Supported by the National Natural Science Foundation of China (30170986).
文摘Objective To explore the relationship between human cytomegalovirus (HCMV) UL144 sequence variability and clinical disease. Methods HCMV UL144 open reading frame (ORF) was amplified by PCR assay in 72 lowpassage isolates [65 con-genitally infective children and 7 healthy children who were HCMV-DNA positive by quantitative PCR (qPCR)]. All positive PCR products were analyzed by heteroduplex mobility assay and single-stranded conformation polymorphism (HMA-SSCP) and 32 of them were sequenced. Results Fifty-five patient isolates and five healthy children isolates were HCMV-UL144 positive by PCR. Sequencing and HMA-SSCP analysis showed that significant strain-specific variability was present in the UL144 ORF. Phylogenetic analysis indicated that the nucleotide sequences could be separated into 3 major genotypes. Comparing between UL144 se-quences and the corresponding symptoms showed that genotype 2 did not exist in megacolon isolates. And genotype 1 and 3 were the major types among microcephaly and jaundice isolates respectively. Conclusions HCMV-UL144 existed in most of low passage isolates and sequences were hypervariable. The UL144 ORF and its predicted product with the high level of sequence variability in different kinds of isolates suggest that UL144 ORF might play a role in HCMV infectivity and subsequent diseases.
基金The financial support of the Ministry of the Instruction, University and Research of Italy (MIUR)
文摘Framed structures are usually infilled with masonry walls. They may cause a significant increase in both stiffness and strength, reducing the deformation demand and increasing the energy dissipation capacity of the system. On the other hand, irregular arrangements of the masonry panels may lead to the concentration of damage in some regions, with negative effects; for example soft story mechanisms and shear failures in short columns. Therefore, the presence ofinfill walls should not be neglected, especially in regions of moderate and high seismicity. To this aim, simple models are available for solid infills walls, such as the diagonal no-tension strut model, while infilled frames with openings have not been adequately investigated. In this study, the effect of openings on the strength and stiffness of infilled frames is investigated by means of about 150 experimental and numerical tests. The main parameters involved are identified and a simple model to take into account the openings in the infills is developed and compared with other models proposed by different researchers. The model, which is based on the use of strength and stiffness reduction factors, takes into account the opening dimensions and presence of reinforcing elements around the opening. An example of an application of the proposed reduction factors is also presented.
文摘Steel 20Mn23AlV is a type of high aluminum steel with a very low ladle free-opening rate. The aluminum composition of 20Mn23AlV ranges from 1.6% to 2.45% ,which is significantly higher than other types of steel. According to the real condition of 40 t ladle in steel-making plant of Baosteel Special Steel Company, previous works show that the key factors affecting the ladle free-opening rate of high aluminum steel in continuous casting are：sand material, accessories baking, ladle nozzle cleaning, the process and amount of adding sand, and the rate of argon stirring during refining. Therefore, improving the ladle filler sand quality, baking all of the raw materials, controlling the addition of ladle filler sand, cleaning the ladle nozzle, and optimizing argon stirring during the refining process can resolve the problem of a low ladle free-opening rate of high aluminum steel caused by the long ladle time of liquid steel.
文摘BACKGROUND Severe open tibia fractures are challenging to treat with a lack of published clear management strategies.Our aim was to provide an overview of the largest singlecenter experience in the literature,with minimum 1-year follow-up,of adult type 3 open tibial shaft fractures at Cambridge University Hospitals(a United Kingdom major trauma center).We sought to define patient characteristics and our main outcome measures were infection,union and re-fracture.AIM To retrospectively define patient and injury characteristics,present our surgical methods and analyze our outcomes–namely infection,union and re-fracture rates.METHODS Consecutive series of 74 patients with 75 open tibial fractures treated between 2014 and 2020(26 classified as Gustilo-Anderson 3A,47 were 3B and two were 3C).Nine patients underwent intramedullary nailing(IMN),61 underwent Taylor spatial frame(TSF)fixation and 5 were treated with Masquelet technique(IMN and subsequent bone grafting).RESULTS Mean follow-up was 16 mo(IMN)and 25 mo(TSF).We had an infection rate of 6.7%(5),non-union rate of 4%(3)and re-fracture rate of 2.7%(2).Average time to union was 22 wk for IMN and 38.6 wk for TSF.Thirty-three cases had a bone defect with a mean of 5.4 cm(2-11).Patient age,sex,diabetes,smoking status or injury severity did not have a significant effect on union time with either fixation method.Our limb salvage rate was 98.7%.CONCLUSION Grade 1 to 3A injuries can effectively be treated with reamed or unreamed IMN.Grade 3B/C injuries are best treated by circular external fixators as they provide good,reproducible outcomes and allow large bone defects to be addressed via distraction osteogenesis.
文摘Objective: To evaluate the effectiveness of the damage control, in emergency to treat the open tibial pilon fractures with Dolphix? External Fixator Frame(CITIEFFE?, Calderara di Reno, Bologna, Italy). Methods: From January 2017 to August 2017, at the Department of Orthopedics and Traumatology of Vito Fazzi Hospital Lecce, we treated 23 open tibial pilon fractures with Dolphix? External Fixator Frame(CITIEFFE?, Calderara di Reno, Bologna, Italy). The evaluation criteria of the case series were: the time needed to assemble the external fixator;the time taked to treat the ankle associated lesions;the time of skin healing;the ankle alignment;the subjective/objective Ovadia and Beals score;and complications. The Endpoint assessment was set at the days of the definitive surgery. Results: The results in terms of alignment, biomechanical stability of the frame, healing of soft tissue, complications were as good as the objective and subjective results according Ovadia and Beals score. Conclusion:Pilon fractures are complex and often present complications;the damage control treatment, in emergency, with Dolphix? External Fixator Frame(CITIEFFE?, Calderara di Reno, Bologna, Italy) permits a stable osteotaxis with minimal soft tissue damage and permit the repair of muscles, blood vessels and nerves with a stable bone and the soft tissue healing with vaccum therapy.
基金supported by the National Natural Science Foundation of China (NSFC,Grant Nos.11473001,11233004,11078006,11633009 and 11273067)the Minor Planet Foundation of Purple Mountain Observatory+2 种基金supported by the National Key Basic Research Program of China (2014CB845700)the China Postdoctoral Science Foundation (Grant No.2017M610695)supported by Special Funding for Advanced Users,budgeted and administrated by the Center for Astronomical Mega-Science,Chinese Academy of Sciences
文摘The Xuyi Schmidt Telescope Photometric Survey of the Galactic Anti-center（XSTPS-GAC）is a photometric sky survey that covers nearly 6000 deg^2 towards the Galactic Anti-center（GAC） in the g,r,i bands. Half of its survey field is located on the Galactic Anti-center disk,which makes XSTPSGAC highly suitable to search for new open clusters in the GAC region. In this paper,we report new open cluster candidates discovered in this survey,as well as properties of these open cluster candidates,such as age,distance and reddening,derived by isochrone fitting in the color-magnitude diagram（CMD）.These open cluster candidates are stellar density peaks detected in the star density maps by applying the method from Koposov et al. Each candidate is inspected in terms of its true color image composed from three XSTPS-GAC band images. Then its CMD is checked,in order to identify whether the central region stars have a clear isochrone-like trend differing from background stars. The parameters derived from isochrone fitting for these candidates are mainly based on three band photometry of XSTPS-GAC.Moreover,when these new candidates are able to be seen clearly in 2 MASS data,their parameters are also derived based on the 2 MASS（J-H,J） CMD. There are a total of 320 known open clusters rediscovered and 24 new open cluster candidates discovered in this work. Furthermore,the parameters of these new candidates,as well as another 11 previously known open clusters,are properly determined for the first time.
文摘It has been found that there are marked errors in the value of valid opening size of heat-bonded nonwoven fabrics between theoretical calculations and engineering measurements. A new modified theoretical model is advanced in this paper. The equivalent diameter of the pore of a fibre web is used to calculate the valid opening size instead of the maximum diameter of inscribed circle used, because the fibres in practical fibre webs are flexible elastomers with definite diameters and the pore of fibre web may produce deformation in screening teat and engineering usage. The results show that the theoretical calculations coincide well with the engineering measurements. This method offers a theoretical basis for computer simulation to the performance of filters of heatbonded nonwoven fabrics.
基金supported by the National Natural Science Foundation of China(NSFC,Grant No.11403004)
文摘This paper presents a preliminary test of the k-th nearest neighbor distance （KNND） method for detecting nearby open clusters based on Gaia-DR1. We select 38 386 nearby stars （〈 100 pc） from the Gaia-DR1 catalog, and then use the KNND method to detect overdense regions in three-dimensional space. We find two overdense regions （the Hyades and Coma Berenices （Coma Ber） open clusters）, and obtain 57 reliable cluster members. Based on these cluster members, the distances to the Hyades and Coma Ber clusters are determined to be 46.0±0.2 and 83.5±0.3 pc, respectively. Our results demonstrate that the KNND method can be used to detect open clusters based on a large volume of astrometry data.
基金the National Natural Science Foundation of China(NSFC)through grants 12003022,12373035,12233009 and 12173047support from the Youth Innovation Promotion Association of the CAS(grant No.2022055)。
文摘Open clusters are the basic building blocks that serve as a laboratory for the study of young stellar populations in the Milky Way.Variable stars in open clusters provide a unique way to accurately probe the internal structure,temporal and dynamical evolutionary stages of individual stars and the host cluster.The most powerful tool for such studies is time-domain photometric observations.This paper follows the route of our previous work,concentrating on a photometric search for variable stars in NGC 884.The target cluster is the companion of NGC869,forming the well-known double cluster system that is gravitationally bound.From the observation run in 2016 November,a total of 9247 B-band CCD images and 8218Ⅴ-band CCD images were obtained.We detected a total of 15 stars with variability in visual brightness,including five Be stars,three eclipsing binaries,and seven of unknown types.Two new variable stars were discovered in this work.We also compared the variable star content of NGC 884 with its companion NGC 869.
文摘目的探讨长散在核元件1读码框2基因(L1-ORF2)对GES-1细胞衰老的影响及分子调控机制。方法采用高糖诱导法构建GES-1细胞衰老模型,构建L1-ORF2 si RNA载体,脂质体法将其瞬时转染正常及衰老的GES-1细胞,转染48h后用细胞计数法绘制细胞生长曲线,流式细胞仪分析细胞周期,β-半乳糖苷酶染色检测细胞衰老情况,Western blotting检测转染细胞中L1-ORF2、P53、P21蛋白表达水平。结果成功构建了稳定的GES-1细胞衰老模型及L1-ORF2si RNA载体。与转染了阴性对照载体的细胞相比,转染L1-ORF2 si RNA载体的正常及衰老GES-1细胞的L1-ORF2表达均下降(P<0.05)。与转染阴性对照载体的衰老GES-1细胞相比,转染L1-ORF2 si RNA载体的衰老GES-1细胞增殖速度变快(P<0.05),G0/G1期比例明显减少(34.2%vs 39.3%,P<0.05),β-半乳糖苷酶染色比例下降(56%vs 69%,P<0.05),而转染阴性对照载体和L1-ORF2 si RNA载体的正常GES-1细胞相比则无明显差异(P>0.05)。P53蛋白仅在衰老GES-1细胞中有表达,在正常GES-1细胞中无表达,而P21蛋白在正常和衰老的GES-1细胞中均有表达,且后者表达更高(P<0.05)。与转染阴性对照载体的细胞相比,转染L1-ORF2 si RNA载体的GES-1细胞P53、P21蛋白表达量明显下降(P<0.05)。结论L1-ORF2 si RNA载体可使正常及衰老的GES-1细胞中L1-ORF2表达下调,促进衰老GES-1细胞的生长和增殖,而对正常GES-1细胞无明显影响。P53、P21蛋白参与了L1-ORF2调控细胞衰老的过程。
