BACKGROUND Juvenile polyps(JPs)are non-neoplastic polyps.In adults,JPs present with hematochezia in only approximately half the patients and are often found incidentally during endoscopic screening.JPs have no mucosal...BACKGROUND Juvenile polyps(JPs)are non-neoplastic polyps.In adults,JPs present with hematochezia in only approximately half the patients and are often found incidentally during endoscopic screening.JPs have no mucosal fascia at the tip,and spontaneous shedding and massive gastrointestinal hemorrhage may occur.Thus,the JP bleeding detected in this case by extravascular contrast leakage on computed tomography scans and treated with endoscopic clipping is rare.CASE SUMMARY A previously healthy 31-year-old male patient presented with a 2-day history of bloody stools.Upon hospital arrival,rectal examination revealed fresh blood,and abdominal computed tomography scans showed extravascular contrast leakage from the lower rectum’s left-side wall.His blood pressure was slightly low at 104/62 mmHg.However,his pulse rate(69 bpm)and oxygen level(99%on room air)were within normal limits.Emergency endoscopy revealed a pedunculated lesion in the rectum covered by a non-neoplastic mucosal epithelium.No neoplastic lesions were observed at the tip of the polyp;however,pulsatile bleeding was detected at the distal end.We performed endoscopic hemostasis by clipping the stem and then performed a polypectomy above the stem to examine the lesion tissue.Histopathological evaluation revealed a cystically dilated gland without neoplastic lesions.A subsequent total colonoscopy revealed two JPs with characteristic edematous,smooth,and reddish surfaces close to the hemorrhagic lesion.Subsequent histopathological evaluation indicated findings characteristic of JP,such as severe inflammatory cell infiltration of the stroma and cystic dilatation of the glandular ducts.CONCLUSION There are no reports of adult JPs presenting with contrast extravasation where endoscopic hemostasis was successful,as in this case.展开更多
Community detection is one of the most fundamental applications in understanding the structure of complicated networks.Furthermore,it is an important approach to identifying closely linked clusters of nodes that may r...Community detection is one of the most fundamental applications in understanding the structure of complicated networks.Furthermore,it is an important approach to identifying closely linked clusters of nodes that may represent underlying patterns and relationships.Networking structures are highly sensitive in social networks,requiring advanced techniques to accurately identify the structure of these communities.Most conventional algorithms for detecting communities perform inadequately with complicated networks.In addition,they miss out on accurately identifying clusters.Since single-objective optimization cannot always generate accurate and comprehensive results,as multi-objective optimization can.Therefore,we utilized two objective functions that enable strong connections between communities and weak connections between them.In this study,we utilized the intra function,which has proven effective in state-of-the-art research studies.We proposed a new inter-function that has demonstrated its effectiveness by making the objective of detecting external connections between communities is to make them more distinct and sparse.Furthermore,we proposed a Multi-Objective community strength enhancement algorithm(MOCSE).The proposed algorithm is based on the framework of the Multi-Objective Evolutionary Algorithm with Decomposition(MOEA/D),integrated with a new heuristic mutation strategy,community strength enhancement(CSE).The results demonstrate that the model is effective in accurately identifying community structures while also being computationally efficient.The performance measures used to evaluate the MOEA/D algorithm in our work are normalized mutual information(NMI)and modularity(Q).It was tested using five state-of-the-art algorithms on social networks,comprising real datasets(Zachary,Dolphin,Football,Krebs,SFI,Jazz,and Netscience),as well as twenty synthetic datasets.These results provide the robustness and practical value of the proposed algorithm in multi-objective community identification.展开更多
Vehicle Edge Computing(VEC)and Cloud Computing(CC)significantly enhance the processing efficiency of delay-sensitive and computation-intensive applications by offloading compute-intensive tasks from resource-constrain...Vehicle Edge Computing(VEC)and Cloud Computing(CC)significantly enhance the processing efficiency of delay-sensitive and computation-intensive applications by offloading compute-intensive tasks from resource-constrained onboard devices to nearby Roadside Unit(RSU),thereby achieving lower delay and energy consumption.However,due to the limited storage capacity and energy budget of RSUs,it is challenging to meet the demands of the highly dynamic Internet of Vehicles(IoV)environment.Therefore,determining reasonable service caching and computation offloading strategies is crucial.To address this,this paper proposes a joint service caching scheme for cloud-edge collaborative IoV computation offloading.By modeling the dynamic optimization problem using Markov Decision Processes(MDP),the scheme jointly optimizes task delay,energy consumption,load balancing,and privacy entropy to achieve better quality of service.Additionally,a dynamic adaptive multi-objective deep reinforcement learning algorithm is proposed.Each Double Deep Q-Network(DDQN)agent obtains rewards for different objectives based on distinct reward functions and dynamically updates the objective weights by learning the value changes between objectives using Radial Basis Function Networks(RBFN),thereby efficiently approximating the Pareto-optimal decisions for multiple objectives.Extensive experiments demonstrate that the proposed algorithm can better coordinate the three-tier computing resources of cloud,edge,and vehicles.Compared to existing algorithms,the proposed method reduces task delay and energy consumption by 10.64%and 5.1%,respectively.展开更多
Improving the efficacy of phytoextraction is critical for its successful application in metal contaminated soils. Mineral nutrition affects plant growth and metal absorption and subsequently the accumulation of heavy ...Improving the efficacy of phytoextraction is critical for its successful application in metal contaminated soils. Mineral nutrition affects plant growth and metal absorption and subsequently the accumulation of heavy metal through hyper-accumulator plants. This study assessed the effects of di-hydrogen phosphates （KH2PO4, Ca（H2PO4）2, NaH2PO4 and NH4H2PO4） application at three levels （22, 88 and 352 mg P/kg soil） on Sedum alfredii growth and metal uptake by three consecutive harvests on aged and Zn/Cd combined contaminated paddy soil. The addition of phosphates （P） significantly increased the amount of Zn taken up by S. alfredii due to increased shoot Zn concentration and dry matter yield （DMY） （P 〈 0.05）. The highest phytoextraction of Zn and Cd was observed in KH2PO4 and NH4H2PO4 treatment at 352 mg P/kg soil. The amount of Zn removed by phytoextraction increased in the order of 1st clipping 〈 2nd clipping 〈 3rd clipping, and for Cd extraction the order was 2nd clipping 〈 1st clipping 〈 3rd clipping. These results indicate that the application of P fertilizers coupled with multiple cuttings can enhance the removal of Zn and Cd from contaminated soils by S. alfredii, thus shortening the time needed for accomplishing remediation goals.展开更多
Plain reservoirs are shallow, and have low dams and widespread water surfaces.Therefore, wind-wave-induced damage to the dam is one of the important factors affecting the safety of the reservoir.To improve upon unsati...Plain reservoirs are shallow, and have low dams and widespread water surfaces.Therefore, wind-wave-induced damage to the dam is one of the important factors affecting the safety of the reservoir.To improve upon unsatisfactory plain reservoir wave-clipping schemes, a numerical method is proposed to predict and analyze waves in the reservoir in the presence of artificial islands, constructed from dredged sediment.The MIKE21 SW model is applied to a specific plain reservoir for finding the optimal artificial island parameters.The simulated wave height attenuation results are seen to agree well with empirically predicted values.Thus, the validity and reliability of the numerical model are established.Artificial islands at suitable locations in the reservoir can attenuate the wave heights by approximately 10%e30%, which justifies the efficacy of the clipping scheme making use of dredging and island construction.展开更多
With advances in endoscopic technologies,endoscopic clips have been used widely and successfully in the treatment of various types of oesophageal perforations,anastomosis leakages and fistulas. Our aim was to summariz...With advances in endoscopic technologies,endoscopic clips have been used widely and successfully in the treatment of various types of oesophageal perforations,anastomosis leakages and fistulas. Our aim was to summarize the experience with two types of clips: The through-the-scope(TTS) clip and the over-the-scope clip(OTSC). We summarized the results of oesophageal perforation closure with endoscopic clips. We processed the data from 38 articles and 127 patients using PubM ed search. Based on evidence thus far,it can be stated that both clips can be used in the treatment of early(< 24 h),iatrogenic,spontaneous oesophageal perforations in the case of limited injury or contamination. TTS clips are efficacious in the treatment of 10 mm lesions,while bigger(< 20 mm) lesions can be treated successfully with OTSC clips,whose effectiveness is similar to that of surgical treatment. However,the clinical success rate is significantly lower in the case of fistulas and in the treatment of anastomosis insufficiency. Tough prospective randomized multicentre trials,which produce the largest amount of evidence,are still missing. Based on experience so far,endoscopic clips represent a possible therapeutic alternative to surgery in the treatment of oesophageal perforations under well-defined conditions.展开更多
Prompt diagnosis and therapy of aneurysms are critical for patients with nontraumatic subarachnoid hemorrhage （SAH）.The aim of our study was to assess the clinical usefulness of multislice computed tomography angiog...Prompt diagnosis and therapy of aneurysms are critical for patients with nontraumatic subarachnoid hemorrhage （SAH）.The aim of our study was to assess the clinical usefulness of multislice computed tomography angiography （CTA） in the surgical and endovascular treatment of intracranial aneurysms.A total of 195 cases with 206 intracranial aneurysms underwent CTA.Fifty （24%） aneurysms underwent surgical clipping while 156 （76%） aneurysms underwent endovascular coiling.In the five missed aneurysms at digital substraction angiography and the nine aneurysms with mass intracerebral hematomas,surgical treatment was successfully performed based on 16-slice CTA alone,and the other 36 aneurysms were clipped on the main basis of the CTA.The intraoperative findings correlated well with the CTA findings and all aneurysms were clipped successfully.Sixteen-slice CTA image information has been shown to determine the choice of aneurysm therapy and assist the surgical and endovascular treatment of intracranial aneurysms.展开更多
Predicting how human activity will influence the response of alpine grasslands to future warming has many uncertainties.In this study, a field experiment with controlled warming and clipping was conducted in an alpine...Predicting how human activity will influence the response of alpine grasslands to future warming has many uncertainties.In this study, a field experiment with controlled warming and clipping was conducted in an alpine meadow at three elevations（4313 m, 4513 m and 4693 m） in Northern Tibet to test the hypothesis that clipping would alter warming effect on biomass production.Open top chambers（OTCs） were used to increase temperature since July,2008 and the OTCs increased air temperature by approximately 0.9o C ~ 1.8o C during the growing in2012.Clipping was conducted three times one year during growing season and the aboveground parts of all live plants were clipped to approximately 0.01 m in height using scissors since 2009.Gross primary production（GPP） was calculated from the Moderate-Resolution Imaging Spectroradiometer GPP algorithm and aboveground plant production was estimated using the surface-measured normalized difference vegetation index in 2012.Warming decreased the GPP, aboveground biomass（AGB） and aboveground net primary production（ANPP） at all three elevations when clipping was not applied.In contrast, warming increased AGB at all three elevations, GPP at the two lower elevations and ANPP at the two higher elevations when clipping was applied.These findings show that clipping reduced the negative effect of warming on GPP, AGB and ANPP, suggesting that clipping may reduce the effect of climate warming on GPP, AGB and ANPP in alpine meadows on the Tibetan Plateau, and therefore, may be a viable strategy for mitigating the effects of climate change on grazing and animal husbandry on the Tibetan Plateau.展开更多
Aiming at the problem of the peak to average power ratio(PAPR)in coherent optical orthogonal frequency division multiplexing(CO-OFDM),a hybrid PAPR reduction technique of the CO-OFDM system by combining iterative part...Aiming at the problem of the peak to average power ratio(PAPR)in coherent optical orthogonal frequency division multiplexing(CO-OFDM),a hybrid PAPR reduction technique of the CO-OFDM system by combining iterative partial transmit sequence(IPTS)scheme with modified clipping and filtering(MCF)is proposed.The simulation results show that at the complementary cumulative distribution function(CCDF)of 10^(-4),the PAPR of proposed scheme is optimized by 1.86 d B and 2.13 d B compared with those of IPTS and CF schemes,respectively.Meanwhile,when the bit error rate(BER)is 10^(-3),the optical signal to noise ratio(OSNR)are optimized by 1.57 dB and 0.66 d B compared with those of CF and IPTS-CF schemes,respectively.展开更多
Orthogonal frequency division multiplex/offset QAM (OFDM/OQAM) has been proven to be a promising multi-carrier modulation (MCM) technique for the transmission of signals over multipath fading channels. However, OFDM/O...Orthogonal frequency division multiplex/offset QAM (OFDM/OQAM) has been proven to be a promising multi-carrier modulation (MCM) technique for the transmission of signals over multipath fading channels. However, OFDM/OQAM has also the intrinsic disadvantage of high peak-to-average-power ratio (PAPR) that should be alleviated. This paper focuses on the reduction of the clipping noise and out-of band radiation caused by the clipping process. The basic principle is to estimate the clipping noise and then eliminate it from the received signal. Analysis and simulation results show that, with one time iteration, the proposed method can effectively improve the bit error ratio (BER) performance.展开更多
AIM To determine if prophylactic clipping of post-polypectomy endoscopic mucosal resection(EMR) mucosal defects of large,flat,right sided polyps prevents perforations.METHODS IRB approved review of all colonoscopies,a...AIM To determine if prophylactic clipping of post-polypectomy endoscopic mucosal resection(EMR) mucosal defects of large,flat,right sided polyps prevents perforations.METHODS IRB approved review of all colonoscopies,and prospective data collection of grasp and snare EMR performed by 2 endoscopists between January 1,2010 and March 31,2014 in a community ambulatory endoscopy center.The study consisted of two phases.In the first phase,all right-sided,flat polyps greater than or equal to 1.2 cm in size were removed using the grasp and snare technique.Clipping was done at the discretion of the endoscopist.In the second phase,all mucosal defects were closed using resolution clips.Phase 2 of the study was powered to detect a statistically significant difference in perforation rate with 148 EMRs,if less than or equal to 2 perforations occurred.RESULTS In phase 1 of the study,2121 colonoscopies were performed.Seventy-five patients had 95 large polyps removed.There were 4 perforations in 95 polypectomies(4.2%).The perforations occurred in polyps ranging in size from 1.5 cm to 2.5 cm.In phase 2,there were 2464 colonoscopies performed.One hundred and sixteen patients had 151 large polyps removed,and all mucosal defects were clipped.There were no perforations(P=0.0016).There were no post-polypectomy hemorrhages in either phase.An average of 2.15 clips were required to close the mucosal defects.The median time to perform the polypectomy and clipping was 13 min,and the median procedure duration was 40 min.Five percent of all patients undergoing colonoscopy in our community based,ambulatory endoscopy center had flat,right sided polyps greater than or equal to 1.2 cm in size.CONCLUSION Prophylactic clipping of the mucosal resection defect of large,right-sided,flat polyps reduces the incidence of perforation.展开更多
Blood samples have traditionally been used as the main source of DNA for genetic analysis. How-ever, this source can be difficult in terms of collection, transportation, and long-term storage. In this study, we invest...Blood samples have traditionally been used as the main source of DNA for genetic analysis. How-ever, this source can be difficult in terms of collection, transportation, and long-term storage. In this study, we investigated whether human nail clippings could be used as a source of DNA for SNP genotyping, null-allele detection, and whole-genome amplification. From extracted nail DNA, we achieved amplicons up to a length of ~400 bp and >96% concordance for SNP genotyping and 100% concordance for null-allele detection compared to DNA derived from matched blood sam-ples. For whole-genome amplification, OmniPlex performed better than Multiple Displacement Amplification with a success rate of 89.3% and 76.8% for SNP genotyping and null-allele detection, respectively. Concordance was ~98% for both methods. When combined with OmniPlex whole-genome amplification, human nail clippings could potentially be used as an alternative to whole blood as a less invasive and more convenient source of DNA for genotyping studies.展开更多
A new algorithm for clipping line segments by a rectangular window on rectangular coordinate system is presented in this paper. The algorithm is very different to the other line clipping algorithms. For the line segme...A new algorithm for clipping line segments by a rectangular window on rectangular coordinate system is presented in this paper. The algorithm is very different to the other line clipping algorithms. For the line segments that cannot be identified as completely inside or outside the window by simple testings, this algorithm applies affine transformations (the shearing transformations) to the line segments and the window, and changes the slopes of the line segments and the shape of the window. Thus, it is clear for the line segment to be outside or inside of the window. If the line segments intersect the window, the algorithm immediately (no solving equations) gets the intersection points. Having applied the inverse transformations to the intersection points, the algorithm has the final results. The algorithm is successful to avoid the complex classifications and computations. Besides, the algorithm is effective to simplify the processes of finding the intersection points. Comparing to some classical algorithms, the algorithm of this paper is faster for clipping line segments and more efficient for calculations.展开更多
文摘BACKGROUND Juvenile polyps(JPs)are non-neoplastic polyps.In adults,JPs present with hematochezia in only approximately half the patients and are often found incidentally during endoscopic screening.JPs have no mucosal fascia at the tip,and spontaneous shedding and massive gastrointestinal hemorrhage may occur.Thus,the JP bleeding detected in this case by extravascular contrast leakage on computed tomography scans and treated with endoscopic clipping is rare.CASE SUMMARY A previously healthy 31-year-old male patient presented with a 2-day history of bloody stools.Upon hospital arrival,rectal examination revealed fresh blood,and abdominal computed tomography scans showed extravascular contrast leakage from the lower rectum’s left-side wall.His blood pressure was slightly low at 104/62 mmHg.However,his pulse rate(69 bpm)and oxygen level(99%on room air)were within normal limits.Emergency endoscopy revealed a pedunculated lesion in the rectum covered by a non-neoplastic mucosal epithelium.No neoplastic lesions were observed at the tip of the polyp;however,pulsatile bleeding was detected at the distal end.We performed endoscopic hemostasis by clipping the stem and then performed a polypectomy above the stem to examine the lesion tissue.Histopathological evaluation revealed a cystically dilated gland without neoplastic lesions.A subsequent total colonoscopy revealed two JPs with characteristic edematous,smooth,and reddish surfaces close to the hemorrhagic lesion.Subsequent histopathological evaluation indicated findings characteristic of JP,such as severe inflammatory cell infiltration of the stroma and cystic dilatation of the glandular ducts.CONCLUSION There are no reports of adult JPs presenting with contrast extravasation where endoscopic hemostasis was successful,as in this case.
文摘Community detection is one of the most fundamental applications in understanding the structure of complicated networks.Furthermore,it is an important approach to identifying closely linked clusters of nodes that may represent underlying patterns and relationships.Networking structures are highly sensitive in social networks,requiring advanced techniques to accurately identify the structure of these communities.Most conventional algorithms for detecting communities perform inadequately with complicated networks.In addition,they miss out on accurately identifying clusters.Since single-objective optimization cannot always generate accurate and comprehensive results,as multi-objective optimization can.Therefore,we utilized two objective functions that enable strong connections between communities and weak connections between them.In this study,we utilized the intra function,which has proven effective in state-of-the-art research studies.We proposed a new inter-function that has demonstrated its effectiveness by making the objective of detecting external connections between communities is to make them more distinct and sparse.Furthermore,we proposed a Multi-Objective community strength enhancement algorithm(MOCSE).The proposed algorithm is based on the framework of the Multi-Objective Evolutionary Algorithm with Decomposition(MOEA/D),integrated with a new heuristic mutation strategy,community strength enhancement(CSE).The results demonstrate that the model is effective in accurately identifying community structures while also being computationally efficient.The performance measures used to evaluate the MOEA/D algorithm in our work are normalized mutual information(NMI)and modularity(Q).It was tested using five state-of-the-art algorithms on social networks,comprising real datasets(Zachary,Dolphin,Football,Krebs,SFI,Jazz,and Netscience),as well as twenty synthetic datasets.These results provide the robustness and practical value of the proposed algorithm in multi-objective community identification.
基金supported by Key Science and Technology Program of Henan Province,China(Grant Nos.242102210147,242102210027)Fujian Province Young and Middle aged Teacher Education Research Project(Science and Technology Category)(No.JZ240101)(Corresponding author:Dong Yuan).
文摘Vehicle Edge Computing(VEC)and Cloud Computing(CC)significantly enhance the processing efficiency of delay-sensitive and computation-intensive applications by offloading compute-intensive tasks from resource-constrained onboard devices to nearby Roadside Unit(RSU),thereby achieving lower delay and energy consumption.However,due to the limited storage capacity and energy budget of RSUs,it is challenging to meet the demands of the highly dynamic Internet of Vehicles(IoV)environment.Therefore,determining reasonable service caching and computation offloading strategies is crucial.To address this,this paper proposes a joint service caching scheme for cloud-edge collaborative IoV computation offloading.By modeling the dynamic optimization problem using Markov Decision Processes(MDP),the scheme jointly optimizes task delay,energy consumption,load balancing,and privacy entropy to achieve better quality of service.Additionally,a dynamic adaptive multi-objective deep reinforcement learning algorithm is proposed.Each Double Deep Q-Network(DDQN)agent obtains rewards for different objectives based on distinct reward functions and dynamically updates the objective weights by learning the value changes between objectives using Radial Basis Function Networks(RBFN),thereby efficiently approximating the Pareto-optimal decisions for multiple objectives.Extensive experiments demonstrate that the proposed algorithm can better coordinate the three-tier computing resources of cloud,edge,and vehicles.Compared to existing algorithms,the proposed method reduces task delay and energy consumption by 10.64%and 5.1%,respectively.
基金supported by the National Natural Science Foundation of China (No. 30630046, 40701074)the National High Technology Research and Development Program of China (No. 2009AA06Z316)+1 种基金the Ministry of Environmental Protection Program of China(No. 2011467057)the Shanghai Tongji Gao Tingyao Environmental Science & Technology Development Foundation (7th Winner, 2010)
文摘Improving the efficacy of phytoextraction is critical for its successful application in metal contaminated soils. Mineral nutrition affects plant growth and metal absorption and subsequently the accumulation of heavy metal through hyper-accumulator plants. This study assessed the effects of di-hydrogen phosphates （KH2PO4, Ca（H2PO4）2, NaH2PO4 and NH4H2PO4） application at three levels （22, 88 and 352 mg P/kg soil） on Sedum alfredii growth and metal uptake by three consecutive harvests on aged and Zn/Cd combined contaminated paddy soil. The addition of phosphates （P） significantly increased the amount of Zn taken up by S. alfredii due to increased shoot Zn concentration and dry matter yield （DMY） （P 〈 0.05）. The highest phytoextraction of Zn and Cd was observed in KH2PO4 and NH4H2PO4 treatment at 352 mg P/kg soil. The amount of Zn removed by phytoextraction increased in the order of 1st clipping 〈 2nd clipping 〈 3rd clipping, and for Cd extraction the order was 2nd clipping 〈 1st clipping 〈 3rd clipping. These results indicate that the application of P fertilizers coupled with multiple cuttings can enhance the removal of Zn and Cd from contaminated soils by S. alfredii, thus shortening the time needed for accomplishing remediation goals.
基金supported by the National Key Research and Development Program of China(Grants No.2016YFC0401603,2016YFC0401605,and 2016YFC0401607)the Central Public-interest Scientific Institution Basal Research Fund(Grants No.Y717012 and Y718007)
文摘Plain reservoirs are shallow, and have low dams and widespread water surfaces.Therefore, wind-wave-induced damage to the dam is one of the important factors affecting the safety of the reservoir.To improve upon unsatisfactory plain reservoir wave-clipping schemes, a numerical method is proposed to predict and analyze waves in the reservoir in the presence of artificial islands, constructed from dredged sediment.The MIKE21 SW model is applied to a specific plain reservoir for finding the optimal artificial island parameters.The simulated wave height attenuation results are seen to agree well with empirically predicted values.Thus, the validity and reliability of the numerical model are established.Artificial islands at suitable locations in the reservoir can attenuate the wave heights by approximately 10%e30%, which justifies the efficacy of the clipping scheme making use of dredging and island construction.
文摘With advances in endoscopic technologies,endoscopic clips have been used widely and successfully in the treatment of various types of oesophageal perforations,anastomosis leakages and fistulas. Our aim was to summarize the experience with two types of clips: The through-the-scope(TTS) clip and the over-the-scope clip(OTSC). We summarized the results of oesophageal perforation closure with endoscopic clips. We processed the data from 38 articles and 127 patients using PubM ed search. Based on evidence thus far,it can be stated that both clips can be used in the treatment of early(< 24 h),iatrogenic,spontaneous oesophageal perforations in the case of limited injury or contamination. TTS clips are efficacious in the treatment of 10 mm lesions,while bigger(< 20 mm) lesions can be treated successfully with OTSC clips,whose effectiveness is similar to that of surgical treatment. However,the clinical success rate is significantly lower in the case of fistulas and in the treatment of anastomosis insufficiency. Tough prospective randomized multicentre trials,which produce the largest amount of evidence,are still missing. Based on experience so far,endoscopic clips represent a possible therapeutic alternative to surgery in the treatment of oesophageal perforations under well-defined conditions.
基金supported by grant of Changzhou science and technology projects of social development (No. CS2007203)
文摘Prompt diagnosis and therapy of aneurysms are critical for patients with nontraumatic subarachnoid hemorrhage （SAH）.The aim of our study was to assess the clinical usefulness of multislice computed tomography angiography （CTA） in the surgical and endovascular treatment of intracranial aneurysms.A total of 195 cases with 206 intracranial aneurysms underwent CTA.Fifty （24%） aneurysms underwent surgical clipping while 156 （76%） aneurysms underwent endovascular coiling.In the five missed aneurysms at digital substraction angiography and the nine aneurysms with mass intracerebral hematomas,surgical treatment was successfully performed based on 16-slice CTA alone,and the other 36 aneurysms were clipped on the main basis of the CTA.The intraoperative findings correlated well with the CTA findings and all aneurysms were clipped successfully.Sixteen-slice CTA image information has been shown to determine the choice of aneurysm therapy and assist the surgical and endovascular treatment of intracranial aneurysms.
基金funded by the National Natural Science Foundation of China(Grant No.41171084)the Natural Science Foundation of Tibet Autonomous Region(Response of species richness and aboveground biomass to warming in the alpine meadows of Tibet)
文摘Predicting how human activity will influence the response of alpine grasslands to future warming has many uncertainties.In this study, a field experiment with controlled warming and clipping was conducted in an alpine meadow at three elevations（4313 m, 4513 m and 4693 m） in Northern Tibet to test the hypothesis that clipping would alter warming effect on biomass production.Open top chambers（OTCs） were used to increase temperature since July,2008 and the OTCs increased air temperature by approximately 0.9o C ~ 1.8o C during the growing in2012.Clipping was conducted three times one year during growing season and the aboveground parts of all live plants were clipped to approximately 0.01 m in height using scissors since 2009.Gross primary production（GPP） was calculated from the Moderate-Resolution Imaging Spectroradiometer GPP algorithm and aboveground plant production was estimated using the surface-measured normalized difference vegetation index in 2012.Warming decreased the GPP, aboveground biomass（AGB） and aboveground net primary production（ANPP） at all three elevations when clipping was not applied.In contrast, warming increased AGB at all three elevations, GPP at the two lower elevations and ANPP at the two higher elevations when clipping was applied.These findings show that clipping reduced the negative effect of warming on GPP, AGB and ANPP, suggesting that clipping may reduce the effect of climate warming on GPP, AGB and ANPP in alpine meadows on the Tibetan Plateau, and therefore, may be a viable strategy for mitigating the effects of climate change on grazing and animal husbandry on the Tibetan Plateau.
基金supported by the National Natural Science Foundation of China(No.61475118)the State Key Laboratory on Integrated Optoelectronics of China(No.IOSKL2015KF06)the National High-Tech Research and Development Program of China(No.2013AA014201)
文摘Aiming at the problem of the peak to average power ratio(PAPR)in coherent optical orthogonal frequency division multiplexing(CO-OFDM),a hybrid PAPR reduction technique of the CO-OFDM system by combining iterative partial transmit sequence(IPTS)scheme with modified clipping and filtering(MCF)is proposed.The simulation results show that at the complementary cumulative distribution function(CCDF)of 10^(-4),the PAPR of proposed scheme is optimized by 1.86 d B and 2.13 d B compared with those of IPTS and CF schemes,respectively.Meanwhile,when the bit error rate(BER)is 10^(-3),the optical signal to noise ratio(OSNR)are optimized by 1.57 dB and 0.66 d B compared with those of CF and IPTS-CF schemes,respectively.
文摘Orthogonal frequency division multiplex/offset QAM (OFDM/OQAM) has been proven to be a promising multi-carrier modulation (MCM) technique for the transmission of signals over multipath fading channels. However, OFDM/OQAM has also the intrinsic disadvantage of high peak-to-average-power ratio (PAPR) that should be alleviated. This paper focuses on the reduction of the clipping noise and out-of band radiation caused by the clipping process. The basic principle is to estimate the clipping noise and then eliminate it from the received signal. Analysis and simulation results show that, with one time iteration, the proposed method can effectively improve the bit error ratio (BER) performance.
文摘AIM To determine if prophylactic clipping of post-polypectomy endoscopic mucosal resection(EMR) mucosal defects of large,flat,right sided polyps prevents perforations.METHODS IRB approved review of all colonoscopies,and prospective data collection of grasp and snare EMR performed by 2 endoscopists between January 1,2010 and March 31,2014 in a community ambulatory endoscopy center.The study consisted of two phases.In the first phase,all right-sided,flat polyps greater than or equal to 1.2 cm in size were removed using the grasp and snare technique.Clipping was done at the discretion of the endoscopist.In the second phase,all mucosal defects were closed using resolution clips.Phase 2 of the study was powered to detect a statistically significant difference in perforation rate with 148 EMRs,if less than or equal to 2 perforations occurred.RESULTS In phase 1 of the study,2121 colonoscopies were performed.Seventy-five patients had 95 large polyps removed.There were 4 perforations in 95 polypectomies(4.2%).The perforations occurred in polyps ranging in size from 1.5 cm to 2.5 cm.In phase 2,there were 2464 colonoscopies performed.One hundred and sixteen patients had 151 large polyps removed,and all mucosal defects were clipped.There were no perforations(P=0.0016).There were no post-polypectomy hemorrhages in either phase.An average of 2.15 clips were required to close the mucosal defects.The median time to perform the polypectomy and clipping was 13 min,and the median procedure duration was 40 min.Five percent of all patients undergoing colonoscopy in our community based,ambulatory endoscopy center had flat,right sided polyps greater than or equal to 1.2 cm in size.CONCLUSION Prophylactic clipping of the mucosal resection defect of large,right-sided,flat polyps reduces the incidence of perforation.
文摘Blood samples have traditionally been used as the main source of DNA for genetic analysis. How-ever, this source can be difficult in terms of collection, transportation, and long-term storage. In this study, we investigated whether human nail clippings could be used as a source of DNA for SNP genotyping, null-allele detection, and whole-genome amplification. From extracted nail DNA, we achieved amplicons up to a length of ~400 bp and >96% concordance for SNP genotyping and 100% concordance for null-allele detection compared to DNA derived from matched blood sam-ples. For whole-genome amplification, OmniPlex performed better than Multiple Displacement Amplification with a success rate of 89.3% and 76.8% for SNP genotyping and null-allele detection, respectively. Concordance was ~98% for both methods. When combined with OmniPlex whole-genome amplification, human nail clippings could potentially be used as an alternative to whole blood as a less invasive and more convenient source of DNA for genotyping studies.
文摘A new algorithm for clipping line segments by a rectangular window on rectangular coordinate system is presented in this paper. The algorithm is very different to the other line clipping algorithms. For the line segments that cannot be identified as completely inside or outside the window by simple testings, this algorithm applies affine transformations (the shearing transformations) to the line segments and the window, and changes the slopes of the line segments and the shape of the window. Thus, it is clear for the line segment to be outside or inside of the window. If the line segments intersect the window, the algorithm immediately (no solving equations) gets the intersection points. Having applied the inverse transformations to the intersection points, the algorithm has the final results. The algorithm is successful to avoid the complex classifications and computations. Besides, the algorithm is effective to simplify the processes of finding the intersection points. Comparing to some classical algorithms, the algorithm of this paper is faster for clipping line segments and more efficient for calculations.
