Can we improve the diagnostic yield of small bowel video-capsule endoscopy?

Video-capsule endoscopy has revolutionized the examination of small bowel mucosa.However,this modality is relatively young and its diagnostic yield is low.Herein,we discuss different approaches to improve examination's diagnostic yield.There are strong data supporting some of them while there is speculation about the rest.As capsule endoscopy continues to evolve there is also a strong belief that technology will overcome at least some of the obst acles that hamper capsule endoscopy's diagnostic yield sometime in the near future.

Diagnostic yield of small bowel capsule endoscopy depends on the small bowel transit time

AIM:To investigate whether the small bowel transit time(SBTT)influences the diagnostic yield of capsule endoscopy(CE).METHODS:Six hundred and ninety-one consecutive CE procedures collected in a database were analyzed.SBTT and CE findings were recorded.A running mean for the SBTT was calculated and correlated to the diagnostic yield with a Spearman's correlation test.Subgroup analyses were performed for the various indications for the procedure.RESULTS:There was a positive correlation between the diagnostic yield and SBTT(Spearman's rho 0.58,P <0.01).Positive correlations between diagnostic yield and SBTT were found for the indication obscure gastrointestinal bleeding(r=0.54,P<0.01),for polyposis and carcinoid combined(r=0.56,P<0.01)and for the other indications(r=0.90,P<0.01),but not for suspected Crohn's disease(r=-0.40).CONCLUSION:The diagnostic yield in small bowel capsule endoscopy is positively correlated with the small bowel transit time.This is true for all indications except for suspected Crohn's disease.

水稻小粒不育系新组合卓两优1126的高产特征

[目的]挖掘杂交水稻产量潜力,培育超高产品种,既是一道科学难题,也是“藏粮于技”安全战略。本研究旨在解析小粒不育系卓201S配组的杂交稻卓两优1126高产形成规律,为优质高效超级杂交稻培育提供理论支撑。[方法]2022年选用小粒不育系新组合卓两优1126和对照品种超级稻两优培九、Y两优900和湘两优900为试验材料,在湖南省隆回县统一高产栽培,系统比较卓两优1126与其他3个超级杂交稻产量及其产量构成、干物质积累、根系发育和抗倒性,探究小粒不育系新组合卓两优1126高产特征。[结果]卓两优1126产量极显著高于对照,较超级杂交稻第1期代表品种两优培九增产35.07%,较超级杂交稻第4期代表品种Y两优900增产17.84%,较超级杂交稻新代表品种湘两优900增产14.52%。卓两优1126产量的提高主要原因是在保持稳定千粒重和结实率基础上,通过平衡有效穗数与每穗粒数使群体总颖花数显著提升。与对照相比,卓两优1126单茎地上部干质量、根干质量和根冠比均极显著高于对照,表明卓两优1126根系具有显著的生长优势,能够很好地协调植株地下和地上部分的生长,有助于超高产的形成。卓两优1126株高适中,基部3节间总长和穗下节间长度都极显著高于对照,但基部第2节间的弯曲力矩和抗折力与湘两优900的差异未达到显著水平,卓两优1126在增加株高的同时保持了较强的抗倒性。卓两优1126耐低氮,稻米品质综合评级为部标优质2级,极端高温下较对照Y两优1928增产5.53%。[结论]卓两优1126在保持稳定的千粒重和结实率基础上,通过平衡有效穗数与每穗粒数使群体总颖花数显著提升,从而实现超高产。卓两优1126亲本间粒型存在显著差异,可以实现父母本混播混收的全程机械化制种,降低种子生产成本。另外,小粒型不育系千粒重仅为常规不育系的1/2,在制种产量保持不变的前提下,单位制种面积的杂交稻种子粒数比普通不育系多1倍,大幅降低杂交稻的用种成本。因此,以卓两优1126为代表的“小粒种高产稻”模式,能为解决杂交水稻当前困境提供新思路,是新的发展方向。

施氮量与移栽密度对小粒型杂交水稻产量形成的影响

【目的】明确小粒型杂交稻的产量形成特性。【方法】以卓两优0985(小粒型杂交稻)和丰两优4号(对照)为材料,在不同施氮量(0,N0;180 kg/hm^(2),N1;210 kg/hm^(2),N2)和密度(26.7 cm×20.0 cm,D1;20.0 cm×20.0 cm,D2;20.0 cm×16.7 cm,D3)条件下开展大田试验。【结果】两品种LAI、叶片SPAD值随施氮量增大而提高,N1与N2差异不显著,但显著高于N0处理;两品种茎鞘物质输出率随施氮量增大而下降,而叶片物质输出率表现相反;两品种产量随施氮量增加而提高,但N1与N2间差异不显著,不同密度处理下一般以D2处理较高;N0处理下卓两优0985产量显著高于对照品种,而施氮条件下两品种产量相当。【结论】卓两优0985产量形成特性为叶面积较小、穗粒数较多、库源比较大,灌浆中后期光合优势明显,花后物质积累量与茎叶物质转运率、经济系数较高,不施氮条件下具有较高产量等。本研究条件下,卓两优0985以N1D2(180 kg/hm^(2)、20 cm×20 cm)为最佳处理。

Implications of small-bowel transit time in the detection rate of capsule endoscopy: A multivariable multicenter study of patients with obscure gastrointestinal bleeding

AIM To define the role of small-bowel transit time in the detection rate of significant small-bowel lesions.METHODS Small-bowel capsule endoscopy records, prospectively collected from 30 participating centers in the Lombardy Registry from October 2011 to December 2013, were included in the study if the clinical indication was obscure gastrointestinal bleeding and the capsule reached the cecum. Based on capsule findings, we created two groups: P2(significant findings) and P0-1(normal/negligible findings). Groups were compared for age, gender, small-bowel transit time, type of instrument, modality of capsule performance(outpatients vs inpatients), bowel cleanliness, and center volume.RESULTS We retrieved and scrutinized 1,433 out of 2,295 capsule endoscopy records(62.4%) fulfilling the inclusion criteria. Patients were 67 ± 15 years old, and 815(57%) were males. In comparison with patients in the P0-1 group, those in the P2 group(n = 776, 54%) were older(P < 0.0001), had a longer small-bowel transit time(P = 0.0015), and were more frequently examined in low-volume centers(P < 0.001). Age and smallbowel transit time were correlated(P < 0.001), with age as the sole independent predictor on multivariable analysis. Findings of the P2 group were artero-venous malformations(54.5%), inflammatory(23.6%) and protruding(10.4%) lesions, and luminal blood(11.5%).CONCLUSION In this selected, prospectively collected cohort of small-bowel capsule endoscopy performed for obscure gastrointestinal bleeding, a longer small-bowel transit time was associated with a higher detection rate of significant lesions, along with age and a low center volume, with age serving as an independent predictor.

Role of small bowel capsule endoscopy in the diagnosis and management of iron deficiency anemia in elderly: A comprehensive review of the current literature

Iron deficiency anemia(IDA)is common and often under recognized problem in the elderly.It may be the result of multiple factors including a bleeding lesion in the gastrointestinal tract.Twenty percent of elderly patients with IDA have a negative upper and lower endoscopy and two-thirds of these have a lesion in the small bowel(SB).Capsule endoscopy(CE)provides direct visualization of entire SB mucosa,which was not possible before.It is superior to push enteroscopy,enteroclysis and barium radiography for diagnosing clinically significant SB pathology resulting in IDA.Angioectasia is one of the commonest lesions seen on the CE in elderly with IDA.The diagnostic yield of CE for IDA progressively increases with advancing age,and is highest among patients over 85 years of age.Balloon assisted enteroscopy is used to treat the lesions seen on CE.CE has some limitations mainly lack of therapeutic capability,inability to provide precise location of the lesion and false positive results.Overall CE is a very safe and effective procedure for the evaluation of IDA in elderly.

Sustainable Potato Production in the Mountain Area of Ecuador, an Approach to Increase Productivity with Small Scale Farmers

Ecuador potato crop is family based production system. Potato production has two roles in their economy, the first is providing food for their families and the second is a source of income for the household. However small scale farmers have limited access to local markets and most of the sales are through intermediates’ who purchase directly in the field at the lowest price possible. Potato production challenges for the small-scale farmers are among others availability of quality potato seed, direct sales, purchase of agrochemical inputs to maintain their crops and lack of education. In 2021, only 4% of potato farmers used certified seed. Potato yield is still low around 16.1 t·ha-1, in the last 10 years the total potato cultivated area was reduced by at least 50%. The farmers produce “Bokashi” and other organic fertilizer and these are effective to improve soil fertility and plant health. Homemade bio-pesticides reduce agrochemical pesticides. The Decision Support System (DSS) is a handheld device to control late blight, minimizes fungicide applications and improve fungicide rotation. In 2018 Candidatus Liberibacter solanacearum (Lso), the causal agent of zebra chip, and its vector, the potato psyllid Bactericera cockerelli, together created havoc for farmers and researchers. Promotion of early potato varieties INIAP—Libertad is an alternative to lower the impact of this newest pest.

油茶CLE基因家族的鉴定

CLE基因家族编码小分泌蛋白,参与调节植物的生长与发育;CLAVATA3(CLV3)是该家族中与作物产量相关的基因,其序列短、相似度低,鉴定该基因比较困难。本研究利用生物信息学的方法对油茶(Camellia oleifera)基因组数据进行了分析,从注释的蛋白质数据中鉴别出11个油茶CLE基因;开发了一套从基因组序列中预测CLV3基因的方法,鉴别出1个油茶CLV3基因;基因表达分析表明,CoCLV3在种仁、柱头、叶等部位的表达水平较高;利用CLE基因家族蛋白质序列的CLE基序进行比对分析并构建进化树,结果表明,CoCLV3是AtCLV3的同源基因。

Assessment of Sedimentation Impacts on Small Dams—A Case of Small Reservoirs in the Lotsane Catchment

Sedimentation is a major problem for agricultural dams in Botswana, as it reduces the storage capacity and life span of the reservoirs. The process of sedimentation starts from day one of the impounding of water in any given reservoir. Even though a provision is made for every reservoir during planning for a certain storage capacity, specifically for sediment deposition, called dead storage, a major portion of the sediment gets deposited for many years of the reservoir’s life in areas other than the dead storage, and this trend cannot be reversed at easy cost. This study is aimed at the analysis of prevailing sedimentation processes in the nearby dozens of dams found in the Lotsane catchment located within the Limpopo Basin of Botswana, and focuses on assessment of annual sedimentation rate. A spatial analysis and modelling study was conducted based on the Revised Universal Soil Loss Equation and GIS to determine sediment yield and degree of impact of each reservoir for a given landscape, rainfall and catchment heterogeneity. Field observations and soil sampling were carried out in order to determine the factors that lead to reservoir sedimentation. Spatial data on the dams in Lotsane catchment were also collected from Ministry of Agriculture, which were used for ground-truthing, GIS-based calculations and model validation. The average sediment rate and sediment delivery ratio were found to be 1.74 t/ha/year and 81%, respectively. These are useful parameters to estimate service life of the dams and plan remedial measures related to sedimentation problems.

小尾寒羊胴体产量等级评定研究

【目的】小尾寒羊是我国肉裘兼用型、高繁殖力绵羊。对成年去势小尾寒羊胴体进行产量等级划分,旨在合理地确定小尾寒羊胴体价格。【方法】对224只成年小尾寒羊胴体、前腿、后腿称质量,采集其全胴体图像与眼肌图像,基于Python的图像灰度化、Otsu二值化、中值滤波以及Canny边缘化算法等图像处理技术对小尾寒羊胴体结构指标进行处理,并提取具体数据;通过对胴体质量、体长、胸宽、正臀宽、后腿宽、腹部脂肪覆盖度和眼肌面积进行相关性分析、主成分分析(PCA)和多元线性回归分析,确定小尾寒羊产量分级指标为胴体质量和后腿宽,并建立产量预测模型,通过聚类分析和置信分析对小尾寒羊胴体进行产量等级划分。【结果】以胴体质量和后腿宽为分级指标将成年小尾寒羊分为4个产量等级,分别是A级:胴体质量>31.40 kg,后腿宽>16.8 cm;B级:胴体质量27.00~31.40 kg,后腿宽16.2~16.8 cm;C级:胴体质量21.80~27.00 kg,后腿宽15.6~16.2 cm;D级:胴体质量<21.8 kg,后腿宽<15.6 cm。【结论】建立了成年小尾寒羊产量等级划分标准,使其产量分级更加准确,为小尾寒羊胴体产业智能化自动分级提供理论基础及参考依据。

不同生物降解膜在西瓜生产上的应用分析

为研究不同生物降解膜在西瓜生产上的使用效果,推进西瓜绿色生产,开展了不同材质和厚度生物降解膜对比试验。试验以4种不同生物降解膜为材料,以普通PE膜覆盖为对照,以北京春大棚小型西瓜为研究对象,对其覆盖效果、降解速率以及成本效益开展调查分析。结果表明:在提温保温方面金发生物降解膜表现最好;在对西瓜生育期的影响方面,4种全生物降解膜差异不明显,均可以满足西瓜生产的覆盖需求;在西瓜产量和品质方面,金发全生物降解膜表现最好,折合667 m^(2)产量为2964 kg,较对照提高5.56%,中心可溶性固形物含量为11.83%,较对照提高1.10百分点;在降解速率方面,华盛、弘睿和金发全生物降解膜均较对照降解快。综上,金发和华盛2种生物降解膜综合效果较好,适合在北京地区春大棚西瓜生产中应用。

水肥耦合效应对小果型西瓜品质、产量及水分利用效率的影响

以小果型西瓜苏梦6号为材料,在设施栽培条件下探讨了不同施肥量、灌水量耦合对西瓜的品质、产量及水分利用效率的影响。试验结果表明:不同水肥耦合处理下,F_2W_2处理的茎粗最大,F_1W_2的茎粗最小,其他处理无显著差异,且肥料作用大于水肥耦合作用,叶绿素含量无明显差异;西瓜果实葡萄糖含量整体呈现先升高后降低的趋势,F_2W_1、F_2W_2处理的葡萄糖含量最高;果实果糖含量在同一肥料处理水平下,随着用水量的增多而显著下降,表现为稀释效应;西瓜果实的蔗糖、可溶性蛋白及番茄红素含量在不同水肥耦合处理中呈现出显著差异,但无明显规律,果实硝酸盐含量组间无明显差异;不同水肥耦合处理西瓜的单株产量及小区产量差异不大,其中F_3W_2处理的产量最高;不同处理水分利用效率的整体水平较高,在同一肥料处理水平下,水分利用效率随着灌水量增多而逐渐减小,且水分作用大于水肥耦合作用。综合考量植株的茎粗、品质、产量及水分利用效率等多方面因素,在不显著降低西瓜品质的情况下,选择F_1W_1处理为最优的水肥耦合条件。

大荔地区粉细砂地层成井措施的探讨

针对陕西省渭南市大荔地区粉细砂地层成井难的问题,本文对影响粉细砂地层成井质量的因素进行了讨论,在分析粉细砂地层成井产生涌砂及出水量小问题成因的基础上总结了以往解决粉细砂地层成井的方法。根据工程实践经验提出了取芯钻机及水文钻机相结合的方式成井、采用无缝钢管及双层缠丝过滤器成井、抽水填砾等新的举措,对该地区粉细砂地层成井具有工程借鉴意义。

基于小厚度小冲杆试验的管道钢力学性能表征

为解决常规力学性能测试手段无法对高钢级管道局部区域材料的力学性能进行精细表征的问题,对小厚度试样小冲杆试验表征管道钢材料力学性能的经验关联方法进行了研究。对不同钢级管道钢材料分别开展了单轴拉伸试验与标准厚度试样小冲杆试验,通过两者数据关联得到了标准厚度试样小冲杆试验确定高钢级管材屈服强度及抗拉强度的经验公式。在此基础上,以X80钢为例开展了系列非标小厚度试样小冲杆试验,对经验公式进行了厚度效应修正,最终形成了基于小厚度试样小冲杆试验的高钢级管材力学性能表征方法,并进行了适用性验证。研究结果表明:考虑厚度效应的力学性能经验关联公式对于不同批次的X80钢非标小厚度试样小冲杆试验结果适用性良好;关联所得屈服强度及抗拉强度与单轴拉伸试验结果相比最大误差分别为9.87%和5.61%,均满足工程需求。研究结果可为不同高钢级管材力学性能研究提供理论基础与技术支撑。

酒精废醪液体有机碳肥对小番茄根系生长、产量和品质的影响

为了验证酒精废醪液体有机碳肥在小番茄上的施用效果,采用盆栽随机区组试验,设置5个处理:CK(空白对照)、T1(常规施化肥)、T2(酒精废醪液体有机碳肥)、T3(商品液体肥A)和T4(商品液体肥B),液体肥施用量为100 mL/盆。通过测定小番茄的株高、茎粗、叶绿素相对含量(SPAD值)、根系形态、番茄产量、维生素C含量、硝酸盐含量、可溶性糖含量和有机酸含量,比较酒精废醪液体有机碳肥与化肥以及2种市售液体肥对小番茄农艺性状、根系形态、产量和品质的影响。结果表明,与T1处理相比,T2—T4处理可以显著促进小番茄的生长,单株产量提高幅度为8.3%~16.7%,其中T2处理最高;根长、根表面积、根平均直径在T3和T4处理分别降低2.8%和4.3%、0.8%和4.5%、2.0%和0.1%,T2处理分别提高25.7%、23.3%和18.8%;根体积在T2和T3处理分别提高29.4%和2.9%,T4处理下降8.8%;维生素C、可溶性糖含量在T2和T3处理分别增加21.5%和3.0%、15.1%和4.8%,其中均以T2处理最高;T2—T4处理硝酸盐含量降低幅度为15.4%~34.1%,其中以T3处理最低;有机酸含量降低幅度为29.7%~43.8%,其中以T2处理最低。相关性分析表明,小番茄的根长度、根表面积、根体积和根平均直径与产量、维生素C含量和可溶性糖含量均呈显著正相关关系,而根长和根表面积与有机酸含量呈显著负相关关系。由此可见,酒精废醪液体有机碳肥通过促进小番茄根系的生长来提高果实的产量和品质。

钾营养对日光温室小南瓜产量和贮藏特性的影响

研究了不同钾肥用量对日光温室小南瓜产量和贮藏特性的影响。结果表明:施用钾肥能够增加小南瓜叶片的叶绿素含量,提高光合速率;也能使茎秆粗壮,明显提高小南瓜的产量,延长小南瓜采收后的贮藏时间。在本试验范围内,小南瓜的田间适宜施钾量(K2O)为81 kg/hm2。

钾营养对地膜覆盖小南瓜产量和贮藏特性的影响

研究了不同钾肥用量对地膜覆盖小南瓜产量和贮藏特性的影响。结果表明,施用钾肥能够增加小南瓜叶片的叶绿素含量,提高叶片光合速率;使茎秆粗壮,明显提高小南瓜的产量,延长小南瓜采收后的贮藏时间,提高贮藏品质。在本试验范围内,小南瓜田间的适宜施钾量(K2O)为121.5 kg/hm2。

塑性区阻止效应对三维裂纹应力强度因子的影响研究

在应用片条合成法计算三维裂纹尖端应力强度因子基础上,推导了在小范围屈服情况下考虑塑性区影响时三维裂纹尖端应力强度因子的求解公式,讨论了塑性区大小对裂尖应力强度因子的影响,其中重点考虑了塑性区对裂纹发展的阻止效应.通过对结果进行分析和讨论,给出可供工程应用参考的依据.计算结果表明,在考虑了塑性区对裂纹发展的阻止效应后,大多数情况下塑性区修正使应力强度因子比未考虑塑性区修正的应力强度因子要小7%～30%.

武陵山区女儿寨小流域次降雨径流与产沙特征

以武陵山区女儿寨小流域为研究区,根据流域2004—2008年77场典型降雨径流观测资料,研究流域次降雨径流与产沙特征。结果表明:77场降雨中,以25.0～49.9 mm和50.0～100.0 mm的降雨为主,占降雨总数的67.53%,降雨强度以10～40 mm/h为主;降雨量与径流深和产沙模数呈现较为显著的线性相关性,降雨量、径流深及降雨侵蚀力对产沙模数均有明显影响,其中以径流深和产沙模数的拟合效果最好,R2达0.684 7;在对降雨、径流、产沙共12个指标进行相关性分析的基础上,对径流深、洪峰流量、产沙模数、降雨侵蚀力4个主要指标进行多元逐步回归拟合,R2均在0.85以上,并通过显著性检验,回归方程拟合效果较好,可用于相关指标的定量计算;流域的产沙量主要取决于几次大的暴雨,汛期的降雨决定流域的产流产沙状况。研究结果可为流域水土流失监测和预报、水土保持措施合理配置等提供相应参考。

偏最小二乘法与人工神经网络耦合的小流域产沙模型

针对小流域侵蚀产沙的复杂性,将偏最小二乘回归与人工神经网络耦合,建立了小流域降雨侵蚀产沙检验模型,并应用于小流域降雨侵蚀产沙预报.采用偏最小二乘法对多维自变量中的信息进行组合和提取,从而得到对因变量解释能力最强并可很好概括自变量信息的主成分,有效克服了变量之间的多重相关问题,实现了对高维数据的降维处理.把提取的主成分作为神经网络的输入,提高了网络的学习效率和稳健性.应用结果表明,偏最小二乘神经网络耦合模型的拟合和检验精度均优于偏最小二乘回归模型和人工神经网络模型精度.