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Selection of Multifractal Scaling Breaks andSeparation of Geochemical andGeophysical Anomaly 被引量:8
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作者 Cheng Qiuming Department of Earth and Atmospheric Science, Department of Geography, York University, Toronto, Ontario, Canada, M3J 1P3 《Journal of China University of Geosciences》 SCIE CSCD 2001年第1期54-59,共6页
Spatially superimposed multiple processes such as multiplicative cascade processes often generate multifractal measures possessing so-called self-similarity or self-affinity that can be described by power- law type of... Spatially superimposed multiple processes such as multiplicative cascade processes often generate multifractal measures possessing so-called self-similarity or self-affinity that can be described by power- law type of functions within certain scale ranges The multifractalities can be estimated by applying multifractal modeling to the measures reflecting the characteristics of the physical processes such as the element concentration values analyzed in rock and soil samples and caused by the underlying mineralization processes and the other geological processes. The local and regional geological processes may result in geochemical patterns with distinct multifractalities as wall as variable scaling ranges. Separation of these multifractal measures on the basis of both the distinct multifractalities and the scaling ranges will be significant for both theoretical studies of multifractal modeling and its applications. Multifractal scaling breaks have been observed from various multifractal patterns. This paper introduces a technique for separating multifractal measures on the basis of scaling breaks. It has been demonstrated that the method is effective for decomposing geochemical and geophysical anomalies required for mineral exploration. A dataset containing the element concentration values of potassium and phosphorus in soil samples was employed for demonstrating the application of the method for studying the fertilizer and yield optimization in agriculture 展开更多
关键词 mineralization processes SELF-SIMILARITY geochemical anomaly separation multifractal scaling breaks.
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Short bouts of accumulated exercise:Review and consensus statement on definition,efficacy,feasibility,practical applications,and future directions 被引量:1
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作者 Mingyue Yin Yongming Li +43 位作者 Abdul Rashid Aziz Aidan Buffey David J.Bishop Dapeng Bao George P.Nassis Hashim Islam Hongying Wang Jackson J.Fyfe Jianfang Xu Jianxiu Liu Jiexiu Zhao Jingwei Cao Jonathan P.Little Junqiang Qiu Keith M.Diaz Lijuan Wang Liye Zou Max J.Western Meynard L.Toledo Min Hu Minghui Quan Neville Owen Niels B.J.Vollaard Olivier Girard Qingde Shi Richard S.Metcalfe Rodrigo Ramirez-Campillo Ru Wang Waris Wongpipit Weimo Zhu Wenfei Zhu Weigang Xu Xiaochun Wang Xiaoping Chen Xiong Wang Xu Wen Yang Liu Ying Gao Yue Fu Zhaowei Kong Zhenbo Cao Zhengzhen Wang Peijie Chen Lijuan Mao 《Journal of Sport and Health Science》 2026年第2期1-30,共30页
Background:Insufficient physical activity and prolonged sedentary behavior have emerged as major global public health challenges.Short bouts(≤10 min)of accumulated exercise(SBAE)throughout the day may be a promising ... Background:Insufficient physical activity and prolonged sedentary behavior have emerged as major global public health challenges.Short bouts(≤10 min)of accumulated exercise(SBAE)throughout the day may be a promising strategy to mitigate the adverse effects of prolonged sitting and promote physical activity,ultimately promoting overall health.However,previous ambiguity in defining this concept has resulted in a fragmented and inconsistent evidence base,impeding practical applications,the development of guidelines,and policymaking.The purpose of this study is to establish an operational definition of SBAE by synthesizing systematic reviews and research trials alongside an expert consensus.Additionally,it seeks to evaluate acute and long-term efficacy and feasibility,providing evidence-based recommendations for practice and future research directions.Methods:A literature search was performed across PubMed and Web of Science,followed by systematic screening and summarization of eligible studies based on predefined inclusion criteria.Inclusion criteria encompassed various modes/types of SBAE(bouts lasting≤10 min,performed multiple times daily with≥30 min intervals);both aerobic and resistance exercise were considered.Relevant systematic reviews and research trials were included.Methodological quality,risk of bias,and evidence certainty were assessed.Expert consensus was obtained through a survey to evaluate recommendations and agreement levels on findings.Results:After analyzing 27 systematic reviews,135 research studies,and an expert consensus involving 48 researchers from 11 countries,SBAE is defined as any exercise mode of activity,regardless of intensity,that is accumulated in either continuous or intermittent bouts lasting≤10 min per session(including multiple intermittent sets)that are performed multiple times(≥2 sessions/day)per day,with intervals of≥30 min between bouts or otherwise sufficient time for recovery.When used to interrupt prolonged periods of sedentary time,SBAE mitigates the acute adverse effects of sedentary behavior on more than 10 clinical biomarkers of endocrine,cardiovascular,and brain health/function among adults of diverse ages and conditions.Moreover,SBAE was superior for improving acute glycemic control compared to a single continuous exercise session.As a long-term intervention(average of 11 weeks),SBAE can improve over 20 health outcomes,including peak oxygen uptake,resting blood pressure,and metabolic health.Additionally,SBAE might be more effective than continuous exercise for improving longer-term glycemic control and body composition.Long-term completion rates for SBAE interventions are generally high(95%),with low dropout rates(12%)and high adherence rates even without supervision(85%),and its safety has been preliminarily validated.Conclusion:An operational definition of SBAE is provided along with its classification and acute and long-term efficacy.Practical exercise prescription recommendations and evidence-based strategies for various populations and contexts are provided.Future research should focus on generating high-quality evidence for SBAE in 5 key areas:quantification and monitoring,population-specific responses,optimization of exercise prescriptions,intervention efficacy,and practical implementation.Additionally,addressing policy,environmental,and promotional barriers is crucial for transitioning from expert consensus to public consensus,and for facilitating the application of this strategy in real-world environments. 展开更多
关键词 Short bouts of accumulated exercise Exercise snacks Consensus statement Sedentary breaks
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Laser-assisted full-size PDC bit:Drilling performance and parameter optimization
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作者 Bin Liu Bin Xu +3 位作者 Biao Li Bo Zhang Xinjie Huang Tongyuan Liu 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第2期971-985,共15页
Laser-assisted drilling combined with full-size polycrystalline diamond compact(PDC)bit is considered a feasible solution to enhance the drilling performance of engineering machinery.In this method,determining the opt... Laser-assisted drilling combined with full-size polycrystalline diamond compact(PDC)bit is considered a feasible solution to enhance the drilling performance of engineering machinery.In this method,determining the optimal collaborative control parameters that support rapid drilling is crucial for improving the combined performance.This study used average drilling speed,average torque,and total specificenergy for quantitative analysis to characterize the efficiencyand economy of combined rock breaking.Given the advantage of the response surface methodology in providing high-precision predictions with limited experimental data,regression models of the average drilling speed,average torque,and total specificenergy were established.The results showed that as the laser power and irradiation time increased,the average drilling speed firstincreased rapidly and then leveled off,while the average torque decreased sharply before decelerating.The total specificenergy initially decreased and then increased,with the combined drilling outperforming conventional mechanical drilling within specific parameter ranges.As the weight on bit increased,both the average torque and total specificenergy first decreased and then increased.With rising rotating speed,the average torque exhibited a trend of initial increase,then decrease,and finalincrease,whereas the total specificenergy increased slowly at firstand then sharply.Both parameters exhibited optimal values at which the average torque and total specific energy remained at minimal levels.For granite combined drilling,the optimal performance was achieved at a laser power of 3000 W,irradiation time of 31 s,the weight on bit of 2.4 kN,and the rotating speed of 97 r/min. 展开更多
关键词 Laser rock breaking Polycrystalline diamond compact(PDC) CUTTER Combined rock breaking Response surface methodology Parameter optimization
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Relax,Refresh,and Reset in Guizhou
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作者 LU YONGZHENG 《China Today》 2026年第1期52-55,共4页
It’s never too early in the year to start planning a break from the stress of city life,and southwest China’s charming Guizhou Province is a destination that should be right at the top of your list.
关键词 stress southwest China PROVINCE city life BREAK relax GUIZHOU REFRESH
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Numerical investigation of mixed-phase turbulence in flow past a partially merged plate
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作者 Junqi Tong Rong Li Zixuan Yang 《Acta Mechanica Sinica》 2026年第1期3-14,共12页
Large-eddy simulation(LES)is conducted to study the statistical properties of mixed-phase turbulence induced by the breaking of bow waves in flow past a partially submerged plate.The simulation is performed using a fi... Large-eddy simulation(LES)is conducted to study the statistical properties of mixed-phase turbulence induced by the breaking of bow waves in flow past a partially submerged plate.The simulation is performed using a finite difference method,with the air-water interface captured by a coupled level-set and volume-of-fluid method.Four cases are conducted to investigate the effects of Froude number on turbulent statistics,including the mean velocity,turbulence kinetic energy,and turbulence mass flux(TMF),which is an additional unclosed term in the Reynolds-averaged momentum equation.The TMF,especially its vertical component,shows a complex behaviour with respect to the Froude number.This property of the TMF imposes high demands on the robustness of the closure model of TMF.The present LES data is further used to examine a closure model of the TMF production term,which shows a high correlation with the data obtained from LES. 展开更多
关键词 Turbulent flows Multiphase flows Wave breaking
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Irradiation of granite surface by nanosecond pulsed laser:Optimal softening parameters and properties
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作者 LI Zi-kun ZHANG Xue-min +5 位作者 CHEN Jing OU Xue-feng ZHOU Xian-shun WU Chao-guang TANG Ke-lin ZHU Wen-yang 《Journal of Central South University》 2026年第1期317-334,共18页
Irradiating hard rocks by a high-power laser can reduce localized hardness in the rocks;however,continuous lasers produce a large amount of melt that inhibits further heat absorption.Pulsed lasers allow rocks to absor... Irradiating hard rocks by a high-power laser can reduce localized hardness in the rocks;however,continuous lasers produce a large amount of melt that inhibits further heat absorption.Pulsed lasers allow rocks to absorb and dissipate energy and avoid melt formation.In this study,200 W nanosecond pulsed laser was used to irradiate granite.The effects of laser parameters on the thermal cracking morphology,temperature field,warming pattern,and Leeb hardness of the granite surface were analyzed.The optimal laser parameters for softening granite were determined by performing objective optimization in MATLAB using granite's melting point as the reference.Nanoindentation techniques were employed to assess the softening characteristics of the granite surface along the longitudinal direction.The results showed that three main forms of thermal damage occurred on the granite surface:oxidative decomposition,spalling,and melting.The damage state was affected by the average laser power,with the pulse width and repetition frequency affecting surface damage differently.Appropriate laser parameters effectively controlled the melt damage on the granite surface,and irradiation with nanosecond pulsed lasers effectively reduced surface hardness.However,excessive power can generate large amounts of hard melts and weaken the softening effect. 展开更多
关键词 nanosecond pulsed laser assisted rock breaking warming characteristics Leeb hardness nanoindentation test softening characteristics
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Why record-breaking gale and nationwide dust in China in April 2025
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作者 Zhicong Yin Qianyi Huo +2 位作者 Dingzhu Hu Yanyan Huang Hujian Wang 《Science Bulletin》 2026年第3期463-465,共3页
An unprecedented extreme gale and dust event struck East Asia during 10-14 April2025.A record-breaking gale swept across most regions of China.It carried large amounts of dust from northern deserts,resulting in nation... An unprecedented extreme gale and dust event struck East Asia during 10-14 April2025.A record-breaking gale swept across most regions of China.It carried large amounts of dust from northern deserts,resulting in nationwide dust weather.Gales affected more than 3.5 million km^(2),and the windspeeds in North China were the strongest in April since 1940(Fig.1a,b). 展开更多
关键词 east asia windspeeds northern deserts record breaking gale unprecedented extreme gale dust event nationwide dust
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FOCUS
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《China Today》 2026年第1期6-15,共10页
PHOTO NEWS Unforgettable Winter Break Tourists take selfies in front of snow sculptures in the Fenghuang Mountain Scenic Area,Yakeshi City in Inner Mongolia Autonomous Region,on December 7,2025.
关键词 winter break selfies fenghuang mountain scenic area yakeshi city inner mongolia autonomous region TOURISTS snow sculptures december
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Changing Habits
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作者 Ruth Devlin 《空中英语教室(初级版.大家说英语)》 2026年第1期17-19,51,52,共5页
Many people have bad habits,and they are not good for you.Bad habits can be staying up too late,eating too many sweets or biting your nails.Bad habits aren't easy to break,but you can do it!First,notice when you d... Many people have bad habits,and they are not good for you.Bad habits can be staying up too late,eating too many sweets or biting your nails.Bad habits aren't easy to break,but you can do it!First,notice when you do the habit.Then,try to do something else,such as chewing gum or reading a book.Ask a friend to help you stop.They can watch you and remind you.Do your best and don't stop trying.Changing little by little can make a difference! 展开更多
关键词 biting nails breaking habits reading book biting your nailsbad habits eating too many sweets chewing gum staying up too late bad habits
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Monolithically Integrated Optical Convolutional Processors on Thin Film Lithium Niobate
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作者 Rui-Xue Liu Yong Zheng +5 位作者 Yuan Ren Bo-Yang Nan Yun-Peng Song Rong-Bo Wu Min Wang Ya Cheng 《Chinese Physics Letters》 2026年第1期49-63,共15页
Photonic neural networks(PNNs)of sufficiently large physical dimensions and high operation accuracies are envisaged as ideal candidates for breaking the major bottlenecks in the current artificial intelligence archite... Photonic neural networks(PNNs)of sufficiently large physical dimensions and high operation accuracies are envisaged as ideal candidates for breaking the major bottlenecks in the current artificial intelligence architectures in terms of latency,energy efficiency,and computational power.To achieve this vision,it is of vital importance to scale up the PNNs while simultaneously reducing the high demand on the dimensions required by them.The underlying cause of this strategy is the enormous gap between the scales of photonic and electronic integrated circuits.Here,we demonstrate monolithically integrated optical convolutional processors on thin film lithium niobate(TFLN)that harness inherent parallelism in photonics to enable large-scale programmable convolution kernels and,in turn,greatly reduce the dimensions required by subsequent fully connected layers.Experimental validation achieves high classification accuracies of 96%(86%)on the MNIST(Fashion-MNIST)dataset and 84.6%on the AG News dataset while dramatically reducing the required subsequent fully connected layer dimensions to 196×10(from 784×10)and 175×4(from 800×4),respectively.Furthermore,our devices can be driven by commercial field-programmable gate array systems;a unique advantage in addition to their scalable channel number and kernel size.Our architecture provides a solution to build practical machine learning photonic devices. 展开更多
关键词 photonic neural networks pnns artificial intelligence architectures breaking major bottlenecks monolithic integration LATENCY energy efficiency thin film lithium niobate photonic neural networks
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Auto-pick first breaks with complex raypaths for undulate surface conditions 被引量:1
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作者 安圣培 胡天跃 +2 位作者 崔永福 段文胜 彭更新 《Applied Geophysics》 SCIE CSCD 2015年第1期93-100,123,共9页
First-break picking is the key step in seismic data processing for surveying undulate surfaces, and directly infl uences the precision of near-surface modeling and effects of static corrections. The current first-brea... First-break picking is the key step in seismic data processing for surveying undulate surfaces, and directly infl uences the precision of near-surface modeling and effects of static corrections. The current first-break auto-picking methods may fail when the signalto-noise ratio(SNR) is low for seismic data in the undulate area, and require labor and time intensive manual picking. This study develops an improved super-virtual interferometry(SVI) method that combines multichannel and multidomain quality control(MMQC) techniques to achieve auto-picked first breaks. The improved SVI method extends the SVI application to enhance the SNR for near-surface scattered waves for the first time, which allows for the SVI method to adapt to first breaks with complex raypaths by linear combination of refractions and near-surface scattered waves. Methods of inverse and multidomain interferometry are developed to effectively enhance the virtual records extracted by the SVI method. The deconvolution filter for waveforms is used to increase resolution and reduce false picks, while the MMQC technique is designed to auto-correct false picks and increase the stability of auto-picking first breaks. The robust technique developed in this study enables stable processing of large 3D seismic datasets. Higher quality results are obtained using the approach presented in this paper to actual field data from the mountain areas in western China, when compared to some commonly used commercial software. 展开更多
关键词 3D undulate surface INTERFEROMETRY first breaks scattered waves multidomain
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XRCC1 and DNA polymerase β in cellular protection against cytotoxic DNA single-strand breaks 被引量:17
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作者 Julie K Horton Mary Watson +3 位作者 Donna F Stefanick Daniel T Shaughnessy Jack A Taylor Samuel H Wilson 《Cell Research》 SCIE CAS CSCD 2008年第1期48-63,共16页
Single-strand breaks (SSBs) can occur in cells either directly, or indirectly following initiation of base excision repair (BER). SSBs generally have blocked termini lacking the conventional 5'-phosphate and 3'-... Single-strand breaks (SSBs) can occur in cells either directly, or indirectly following initiation of base excision repair (BER). SSBs generally have blocked termini lacking the conventional 5'-phosphate and 3'-hydroxyl groups and require further processing prior to DNA synthesis and ligation. XRCC1 is devoid of any known enzymatic activity, but it can physically interact with other proteins involved in all stages of the overlapping SSB repair and BER pathways, including those that conduct the rate-limiting end-tailoring, and in many cases can stimulate their enzymatic activities. XRCC1^-/- mouse fibroblasts are most hypersensitive to agents that produce DNA lesions repaired by monofunctional glycosylase-initiated BER and that result in formation of indirect SSBs. A requirement for the deoxyribose phosphate lyase activity of DNA polymerase β (pol β) is specific to this pathway, whereas pol β is implicated in gap-filling during repair of many types of SSBs. Elevated levels of strand breaks, and diminished repair, have been demonstrated in MMS- treated XRCC1^-/-, and to a lesser extent in pol β^-/- cell lines, compared with wild-type cells. Thus a strong correlation is observed between cellular sensitivity to MMS and the ability of cells to repair MMS-induced damage. Exposure of wild-type and polβ^-/- cells to an inhibitor of PARP activity dramatically potentiates MMS-induced cytotoxicity. XRCC1^-/- cells are also sensitized by PARP inhibition demonstrating that PARP-mediated poly(ADP-ribosyl)ation plays a role in modulation of cytotoxicity beyond recruitment of XRCC 1 to sites of DNA damage. 展开更多
关键词 XRCC1 DNA polymerase β single-strand break repair base excision repair PARP inhibition
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Non-buckled vitrectomy for retinal detachment with inferior breaks and proliferative vitreoretinophathy 被引量:8
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作者 Yan Sheng, Wu Liu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2012年第5期591-595,共5页
AIM: To investigate the efficacy of non-buckled vitrectomy with classical endotamponade agents in the treatment of primary retinal detachment (RD) complicated by inferior breaks and proliferative vitreoretinophathy (P... AIM: To investigate the efficacy of non-buckled vitrectomy with classical endotamponade agents in the treatment of primary retinal detachment (RD) complicated by inferior breaks and proliferative vitreoretinophathy (PVR). METHODS: A retrospective, consecutive and case series study of 40 patients with inferior break RD and PVR >= C1 was conducted. All patients underwent a standard 3-port 20-gauge pars plana vitrectomy (PPV) with gas or silicone oil tamponade without supplementary scleral buckling. The vitreous and all proliferative membrane were completely removed, and retinectomy was performed when necessary. The mean follow-up was 12.5 months. The primary and final anatomic success rate, visual acuity and complications were recorded and analyzed. RESULTS: Primary anatomic success rate was achieved in 35 of 40 eyes (87.5%) and the final anatomic success rate was 100%. The most common cause of redetachment was recurrent PVR. The best-corrected visual acuity (BCVA) at final follow-up was improved in 34 eyes (85%), remained stable in 1 eye (2.5%), and worsened in 5 eyes (12.5%). The mean visual acuity at final follow-up was improved significantly (P=0.000). CONCLUSION: This retrospective study provides evidence that vitrectomy without scleral buckling seemed to be an effective treatment for inferior break RD with PVR. With complete removal of vitreous and proliferative membranes and timing of retinectomy, the inferior breaks which complicated with PVR could be dosed successfully without additional sclera! buckling. 展开更多
关键词 retinal detachment inferior retinal break proliferative vitreoretinophathy VITRECTOMY
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An Improved Convolutional Neural Network Based Indoor Localization by Using Jenks Natural Breaks Algorithm 被引量:4
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作者 Chengjie Hou Yaqin Xie Zhizhong Zhang 《China Communications》 SCIE CSCD 2022年第4期291-301,共11页
With the rapid growth of the demand for indoor location-based services(LBS),Wi-Fi received signal strength(RSS)fingerprints database has attracted significant attention because it is easy to obtain.The fingerprints al... With the rapid growth of the demand for indoor location-based services(LBS),Wi-Fi received signal strength(RSS)fingerprints database has attracted significant attention because it is easy to obtain.The fingerprints algorithm based on convolution neural network(CNN)is often used to improve indoor localization accuracy.However,the number of reference points used for position estimation has significant effects on the positioning accuracy.Meanwhile,it is always selected arbitraily without any guiding standards.As a result,a novel location estimation method based on Jenks natural breaks algorithm(JNBA),which can adaptively choose more reasonable reference points,is proposed in this paper.The output of CNN is processed by JNBA,which can select the number of reference points according to different environments.Then,the location is estimated by weighted K-nearest neighbors(WKNN).Experimental results show that the proposed method has higher positioning accuracy without sacrificing more time cost than the existing indoor localization methods based on CNN. 展开更多
关键词 indoor localization convolution neural network(CNN) Wi-Fi fingerprints Jenks natural breaks
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Comparison of Densiron 68 and 1 000 cSt silicone oil in the management of rhegmatogenous retinal detachment with inferior breaks 被引量:4
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作者 Ibrahim Kocak Haci Koc 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2013年第1期81-84,共4页
AIM:To compare success rates and complications of Densiron 68 and 1000cSt silicone oil (SO) in the management of rhegmatogenous retinal detachment (RRD) with inferior breaks (IBs). METHODS:Totally 61 eyes of 61 consec... AIM:To compare success rates and complications of Densiron 68 and 1000cSt silicone oil (SO) in the management of rhegmatogenous retinal detachment (RRD) with inferior breaks (IBs). METHODS:Totally 61 eyes of 61 consecutive patients with RRD with IBs were assigned to pars plana vitrectomy (PPV) with Densiron (n =31) or PPV with SO (n=30) in order of presentation. SO and Densiron removal was performed 3 months after initial surgery. Follow up visits were terminated 6 months after SO removal. ·RESULTS:With a single operation, the Densiron group showed 84% and SO 74% reattachment. With further surgery, both groups showed 90% reattachment. Complications such as cataract, raised intraocular pressure (IOP), inflammatory reaction, macular epiretinal membranes, and emulsification of SO were seen in both groups. CONCLUSION:Densiron and SO are found to have similar success rates and complications. 展开更多
关键词 retinal detachment silicone oil Densiron heavy silicone oil inferior break
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DNA Double-Strand Breaks,Potential Targets for HBV Integration 被引量:2
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作者 胡晓文 林菊生 +4 位作者 谢琼慧 任精华 常莹 吴文杰 夏羽佳 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2010年第3期265-270,共6页
Hepatitis B virus(HBV)-induced hepatocellular carcinoma(HCC) is one of the most fre-quently occurring cancers.Hepadnaviral DNA integrations are considered to be essential agents which can promote the process of the he... Hepatitis B virus(HBV)-induced hepatocellular carcinoma(HCC) is one of the most fre-quently occurring cancers.Hepadnaviral DNA integrations are considered to be essential agents which can promote the process of the hepatocarcinogenesis.More and more researches were designed to find the relationship of the two.In this study,we investigated whether HBV DNA integration occurred at sites of DNA double-strand breaks(DSBs),one of the most detrimental DNA damage.An 18-bp I-SceI homing endonuclease recognition site was introduced into the DNA of HepG2 cell line by stable DNA transfection,then cells were incubated in patients’ serum with high HBV DNA copies and at the same time,DSBs were induced by transient expression of I-SceI after transfection of an I-SceI expression vector.By using nest PCR,the viral DNA was detected at the sites of the break.It appeared that integra-tion occurred between part of HBV x gene and the I-SceI induced breaks.The results suggested that DSBs,as the DNA damages,may serve as potential targets for hepadnaviral DNA insertion and the integrants would lead to widespread host genome changes necessarily.It provided a new site to investi-gate the integration. 展开更多
关键词 DNA double-strand breaks hepatitis B virus INTEGRATION non-homologous end joining
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Double-stranded DNA breaks and gene functions in recombination and meiosis 被引量:1
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作者 Wuxing Li Hong Ma 《Cell Research》 SCIE CAS CSCD 2006年第5期402-412,共11页
Meiotic prophase I is a long and complex phase. Homologous recombination is an important process that occurs between homologous chromosomes during meiotic prophase I. Formation of chiasmata, which hold homologous chro... Meiotic prophase I is a long and complex phase. Homologous recombination is an important process that occurs between homologous chromosomes during meiotic prophase I. Formation of chiasmata, which hold homologous chromosomes together until the metaphase I to anaphase I transition, is critical for proper chromosome segregation. Recent studies have suggested that the SPO 11 proteins have conserved functions in a number of organisms in generating sites of double-stranded DNA breaks (DSBs) that are thought to be the starting points of homologous recombination. Processing of these sites of DSBs requires the function of RecA homologs, such as RAD5 1, DMC 1, and others, as suggested by mutant studies; thus the failure to repair these meiotic DSBs results in abnormal chromosomal alternations, leading to disrupted meiosis. Recent discoveries on the functions of these RecA homologs have improved the understanding of the mechanisms underlying meiotic homologous recombination. 展开更多
关键词 MEIOSIS homologous recombination double-stranded DNA breaks SPO11 RAD51 DMC 1
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Missed retinal breaks in rhegmatogenous retinal detachment 被引量:1
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作者 Brijesh Takkar Shorya Azad +3 位作者 Adarsh Shashni Amar Pujari Indrish Bhatia Rajvardhan Azad 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2016年第11期1629-1633,共5页
AIM: To evaluate the causes and associations of missed retinal breaks(MRBs) and posterior vitreous detachment(PVD) in patients with rhegmatogenous retinal detachment(RRD).METHODS: Case sheets of patients under... AIM: To evaluate the causes and associations of missed retinal breaks(MRBs) and posterior vitreous detachment(PVD) in patients with rhegmatogenous retinal detachment(RRD).METHODS: Case sheets of patients undergoing vitreo retinal surgery for RRD at a tertiary eye care centre were evaluated retrospectively. Out of the 378 records screened, 253 were included for analysis of MRBs and191 patients were included for analysis of PVD,depending on the inclusion criteria. Features of RRD and retinal breaks noted on examination were compared to the status of MRBs and PVD detected during surgery for possible associations.RESULTS: Overall, 27% patients had MRBs. Retinal holes were commonly missed in patients with lattice degeneration while missed retinal tears were associated with presence of complete PVD. Patients operated for cataract surgery were significantly associated with MRBs(P =0.033) with the odds of missing a retinal break being1.91 as compared to patients with natural lens. Advanced proliferative vitreo retinopathy(PVR) and retinal bullae were the most common reasons for missing a retinal break during examination. PVD was present in 52% of the cases and was wrongly assessed in 16%. Retinal bullae,pseudophakia/aphakia, myopia, and horse shoe retinal tears were strongly associated with presence of PVD.Traumatic RRDs were rarely associated with PVD. CONCLUSION: Pseudophakic patients, and patients with retinal bullae or advanced PVR should be carefully screened for MRBs. Though Weiss ring is a good indicator of PVD, it may still be over diagnosed in some cases. PVD is associated with retinal bullae and pseudophakia, and inversely with traumatic RRD. 展开更多
关键词 missed retinal breaks retinal detachment ocular examination posterior vitreous detachment retinalsurgery
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Gibberellin A_(3) Treatment Breaks Hypocotyl Dormancy of Paeonia anomala subsp.veitchii Seeds 被引量:3
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作者 HE Wei LI Hui-ping +5 位作者 GAO Ping HAN Qin LIU Bo JIANG Dong-ze LU Si-yu WANG Li-na 《Agricultural Science & Technology》 CAS 2022年第2期20-23,共4页
We studied the roles of different concentrations of gibberellin A_(3)(GA_(3))in breaking hypocotyl dormancy of Paeonia anomala subsp.veitchii,aiming to provide a theoretical basis for the efficient elimination of seed... We studied the roles of different concentrations of gibberellin A_(3)(GA_(3))in breaking hypocotyl dormancy of Paeonia anomala subsp.veitchii,aiming to provide a theoretical basis for the efficient elimination of seed dormancy.The seeds of P.anomala subsp.veitchii were treated with different concentrations of GA_(3)(0,100,200,300,and 400 mg/L)under dark conditions at 16℃,and then the rooting indicators including rooting rate,rooting vigor,rooting index and mold rot rate were determined.The treatment with 400 mg/L GA_(3) for 4 h showed the best performance in breaking the hypocotyl dormancy.Specifically,the treatment shortened the rooting time to 12 d,increased the rooting rate,rooting vigor,and rooting index to 84.00%±5.29%,80.67%±5.03%,and 2.25±0.16 respectively,and decreased the mold rot rate to 0.67%±1.16%.To sum up,there were germination inhibitors in the seeds of P.anomala subsp.veitchii,while the addition of exogenous hormone GA_(3) can release the inhibitory effect on the hypocotyl,which indicated that GA_(3) can promote the breaking of hypocotyl dormancy. 展开更多
关键词 Paeonia anomala subsp.veitchii GIBBERELLIN Breaking of hypocotyl dormancy
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Factor Vector Autoregressive Estimation of Heteroskedastic Persistent and Non Persistent Processes Subject to Structural Breaks 被引量:1
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作者 Claudio Morana 《Open Journal of Statistics》 2014年第4期292-312,共21页
In the paper, a general framework for large scale modeling of macroeconomic and financial time series is introduced. The proposed approach is characterized by simplicity of implementation, performing well independentl... In the paper, a general framework for large scale modeling of macroeconomic and financial time series is introduced. The proposed approach is characterized by simplicity of implementation, performing well independently of persistence and heteroskedasticity properties, accounting for common deterministic and stochastic factors. Monte Carlo results strongly support the proposed methodology, validating its use also for relatively small cross-sectional and temporal samples. 展开更多
关键词 Long and Short Memory Structural breaks Common Factors Principal Components Analysis Fractionally Integrated Heteroskedastic Factor Vector AUTOREGRESSIVE Model
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