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
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
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.
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.
