Hematochezia due to rectal invasion by an internal iliac artery aneurysm: A case report

BACKGROUND This case report presents the rare occurrence of hematochezia due to an internal iliac artery aneurysm leading to an arterioenteric fistula,expanding the differential diagnosis for gastrointestinal bleeding.It emphasizes the importance of considering vascular origins in cases of atypical hematochezia,particularly in the absence of common gastrointestinal causes,and highlights the role of imaging and multidisciplinary management in diagnosing and treating such unusual presentations.CASE SUMMARY A 75-year-old man with a history of hypertension presented with 12 d of hematochezia,experiencing bloody stools 7-8 times per day.Initial computed tomography(CT)scans revealed an aneurysmal rupture near the right internal iliac artery with suspected hematoma development.Hemoglobin levels progressively decreased to 7 g/dL.Emergency arterial angiography and iliac arterycovered stent placement were performed,followed by balloon angioplasty.Despite initial stabilization,minor rectal bleeding and abdominal pain persisted,leading to further diagnostic colonoscopy.This identified a neoplasm and potential perforation at the proximal rectum.An exploratory laparotomy confirmed the presence of a hematoma and an aneurysm invading the rectal wall,necessitating partial rectal resection,intestinal anastomosis,and ileostomy.Postoperative recovery was successful,with no further bleeding incidents and normal follow-up CT and colonoscopy results after six months.CONCLUSION In cases of unusual gastrointestinal bleeding,it is necessary to consider vascular causes for effective diagnosis and intervention.

Intelligent extraction of road cracks based on vehicle laser point cloud and panoramic sequence images

In light of the limited efficacy of conventional methods for identifying pavement cracks and the absence of comprehensive depth and location data in two-dimensional photographs,this study presents an intelligent strategy for extracting road cracks.This methodology involves the integration of laser point cloud data obtained from a vehicle-mounted system and a panoramic sequence of images.The study employs a vehicle-mounted LiDAR measurement system to acquire laser point cloud and panoramic sequence image data simultaneously.A convolutional neural network is utilized to extract cracks from the panoramic sequence image.The extracted sequence image is then aligned with the laser point cloud,enabling the assignment of RGB information to the vehicle-mounted three dimensional(3D)point cloud and location information to the two dimensional(2D)panoramic image.Additionally,a threshold value is set based on the crack elevation change to extract the aligned roadway point cloud.The three-dimensional data pertaining to the cracks can be acquired.The experimental findings demonstrate that the use of convolutional neural networks has yielded noteworthy outcomes in the extraction of road cracks.The utilization of point cloud and image alignment techniques enables the extraction of precise location data pertaining to road cracks.This approach exhibits superior accuracy when compared to conventional methods.Moreover,it facilitates rapid and accurate identification and localization of road cracks,thereby playing a crucial role in ensuring road maintenance and traffic safety.Consequently,this technique finds extensive application in the domains of intelligent transportation and urbanization development.The technology exhibits significant promise for use in the domains of intelligent transportation and city development.

Nursing Practice for a Case of Acute Left Heart Failure Complicated with Colonic Impaction

Research Background: Heart failure is a type of organic heart disease caused by excessive ventricular load, leading to insufficient myocardial contractility and decreased cardiac output in the body. With the progression of the patient's condition, gastrointestinal dysfunction is frequently complicated. At the same time, the accumulation of feces in the body (colonic impaction) can also increase the burden on the patient’s heart, triggering or exacerbating the occurrence or progression of heart failure. Purpose: this article focuses on the correlation between colonic impaction and heart failure, using the nursing experience of a case of acute left heart failure complicated by colonic impaction as an example, in order to provide clinical evidence for the care of patients with colonic impaction combined with heart failure in the future. Method: By using innovative thinking, the stomach tube is used to replace the enema tube, which is inserted through the anus to reach the end of the colon. By combining acupressure at points such as Zhongwan, Tianzhu, and Guanyuan, it helps promote the elimination of fecal impaction. Conclusion: This case reflects the innovative thinking and adaptability of nurses, providing a new clinical approach for the aggravation of the condition of long-term heart failure patients due to constipation issues. Further research in clinical practice is warranted.

基于顶板结构断裂特征的煤矿结构充填关键位置确定方法

充填开采是控制岩层移动并降低地表沉降与环境损害的重要途径,而充填材料来源不足和充填成本高昂现成为制约井工煤矿充填开采推广应用的主要瓶颈。探寻重点区域的低充填率靶向充填新方法与配套技术是充填开采的研究热点之一。为解决上述问题,结合煤矿井下结构充填的学术思想,深入研究了顶板岩层断裂特征,明确了顶板岩层破断块体尺寸及铰接形态,识别了破断铰接块体主沉降区域,判定出结构充填的关键位置。结合关键位置确定方法,提出重点控制基本顶最大挠度位置,即板结构潜在张拉断裂位置(塑性铰发育位置)的“工字型”结构充填新方法。结合新阳矿岩层地质参数,借助FLAC^(3D)数值模拟软件,深入分析了工作面采宽和推进方向上顶板岩层内应力、竖直沉降、塑性区分布规律,揭示了不同方案下充填体稳定性演变特征。结果表明:“工字型”充填在节省充填用量的基础上,较垮落式开采减少初采期直接顶沉降量33.47%,与全部充填仅相差2.3%。同时,关键位置充填体能有效应对顶板回转下沉引起的应力集中,保持自身稳定性,实现对顶板的长效支撑。综合分析得到了新阳矿首采工作面初采期“工字型”结构充填最佳充填方案为中部条带长度72 m,宽度7 m,两侧条带长度18 m,宽度6 m,较全部充填可减少充填材料成本33.86万元。该方案形成的密闭空间为1980 m^(3),占总采出空间的44%,可用来储能或碳封存,助力实现零碳绿色开采,推动双碳目标的实现。

热处理污泥联合间歇梯度曝气实现短程硝化

提出了一种结合热处理污泥和间歇梯度曝气的新策略.在为期120d的实验中,探索了联合策略对氨氧化细菌(AOB)和亚硝酸盐氧化细菌(NOB)的影响.并在此基础上,以排泥比为主要变量,进一步优化短程硝化运行的长期稳定性.结果显示,在未添加外部碳源的条件下,间歇梯度曝气(DO:2.0mg/L//DO:1.2mg/L//DO:0.5mg/L)可以快速恢复因热处理而活性降低的AOB,并在5d内亚硝酸盐氮积累率(NAR)达到80%以上.在稳定运行阶段,比氨氧化速率(SAOR)和比亚硝酸盐氧化速率(SNPR)分别为30.12和6.69mg N/(gVSS⋅h),氨氮出水浓度低于0.1mg/L,亚硝酸盐和硝酸盐的出水浓度分别为53.42和8.01mg/L.进一步研究表明,排泥比设置为1%的反应器相较于排泥比分别为0.5%和1.5%的反应器,展现出更高的NAR(88.96%)和稳定性.

Biosynthesis and Immunological Evaluation of a Dual-Antigen Nanoconjugate Vaccine Against Brucella melitensis

Brucellosis,caused by Brucella,is one of the most common zoonosis.However,there is still no vaccine for human use.Although some live attenuated vaccines have been approved for animals,the protection effect is not ideal.In this study,we developed a dual-antigen nanoconjugate vaccine containing both polysaccharide and protein antigens against Brucella.First,the antigenic polysaccharide was covalently coupled to the outer membrane protein Omp19 using protein glycan coupling technology,and then it was successfully loaded on a nano-carrier through the SpyTag/SpyCatcher system.After confirming the efficient immune activation and safety performance of the dual-antigen nanoconjugate vaccine,the potent serum antibody response against the two antigens and remarkable protective effect in non-lethal and lethal Brucella infection models were further demonstrated through different routes of administration.These results indicated that the dual-antigen nanoconjugate vaccine enhanced both T helper 1 cell(Th1)and Th2 immune responses and protected mice from Brucella infection.Furthermore,we found that this protective effect was maintained for at least 18 weeks.To our knowledge,this is the first Brucella vaccine bearing diverse antigens,including a protein and polysaccharide,on a single nanoparticle.Thus,we also present an attractive technology for co-delivery of different types of antigens using a strategy applicable to other vaccines against infectious diseases.

Rare synchronous colorectal carcinoma with three pathological subtypes: A case report and review of the literature

BACKGROUND Synchronous colorectal carcinomas(SCRC)are two or more primary colorectal carcinomas identified simultaneously or within 6 mo of the initial presentation in a single patient.Their incidence is low and the number of pathological types of SCRC is usually no more than two.It is very unusual that the pathological findings of a patient with SCRC show more than two different pathological subtypes.Here,we report a rare case of SCRC with three pathological subtypes.CASE SUMMARY A 75-year-old woman who had no previous medical history or family history was admitted to the hospital because of intermittent hematochezia for more than a month.Colonoscopy displayed an irregularly shaped neoplasm of the rectum,a tumor-like lesion causing intestinal stenosis in the descending colon,and a polypoidal neoplasm in the ileocecum.Subsequently,she underwent total colectomy,abdominoperineal resection for rectal cancer,and ileostomy.After operation,the pathological report showed three pathological subtypes including well-differentiated adenocarcinoma of the ascending colon,moderately differen-tiated adenocarcinoma of the descending colon,and mucinous adenocarcinoma of the rectum.She is now recovering well and continues to be closely monitored during follow-up.CONCLUSION Preoperative colonoscopy examination,imaging examination,and extensive intraoperative exploration play important roles in reducing the number of missed lesions.

Electron-Exciton Coupling in 1T-TiSe_(2)Bilayer

Excitons in solid state are bosons generated by electron-hole pairs as the Coulomb screening is sufficiently reduced.The exciton condensation can result in exotic physics such as super-fluidity and insulating state.In charge density wave(CDW)state,1T-TiSe_(2) is one of the candidates that may host the exciton condensation.However,to envision its excitonic effect is still challenging,particularly at the two-dimensional limit,which is applicable to future devices.Here,we realize the epitaxial 1T-TiSe_(2) bilayer,the two-dimensional limit for its 2×2×2 CDW order,to explore the exciton-associated effect.By means of high-resolution scanning tunneling spectroscopy and quasiparticle interference,we discover an unexpected state residing below the conduction band and right within the CDW gap region.As corroborated by our theoretical analysis,this mysterious phenomenon is in good agreement with the electron-exciton coupling.Our study provides a material platform to explore exciton-based electronics and opto-electronics.

密云水库流域降水径流非平稳特征识别及归因

为更准确揭示和认识变化环境下密云水库流域水文过程的非平稳特征,选取该流域1960—2019年降水和径流资料,采用多种时间序列分析方法综合诊断其趋势、突变点和周期等非平稳特征并进行成因分析。结果显示:该流域降水变化主要表现出较明显的随机特性,径流相比降水的下降趋势更显著,且在1979年发生了向下跳跃的强变异;相比气候变异影响,人类活动是密云水库流域径流减少的主导因素;1980—1998年流域水土保持措施与水利工程兴建对径流变化的贡献率为-111.40%,抵消了气候变异11.4%的增水效应;1999—2019年,塘坝建造和用地类型转变对径流变化的贡献率为-66.60%,同时叠加气候变异-33.40%的减水效应,导致近20年来该流域径流呈现显著减少的态势。研究结果可为密云水库安全运行、洪水调度以及流域水资源管理决策提供科学支撑。

适应新型电力系统的多维协同电力市场体系

构建适应新型电力系统的电力市场体系,既是实现能源电力转型的必然要求,也是实现“碳达峰·碳中和”目标的重要途径。在全面分析新型电力系统结构改变给电力系统带来的变化与挑战的基础上,构建了适应新型电力系统的目标、时间、空间、价值、主体多维协同的电力市场体系。围绕安全保供、低碳转型与经济的多目标协同,中长期、现货与实时运行的多时间协同,多层次全国统一电力市场的多空间协同,安全-绿色-经济的多价值协同,新型市场主体快速发展下的多主体协同五方面关键问题,提出了多维协同的市场设计思路和核心机制。最后,给出了建设全国统一电力市场的实施路径和建议。

滇东地质高背景区土壤镉的伴矿景天修复及其对后茬水稻的影响

云南是我国典型的重金属元素地球化学高背景区,超积累植物能否有效修复镉(Cd)地质高背景土壤,从而实现农产品安全生产,尚鲜见报道。以云南石林、富源和罗平等三地的典型Cd地质高背景农田土壤为对象,开展温室盆栽试验,探究Cd、锌(Zn)超积累植物伴矿景天对土壤Cd的吸取修复效果,及对后茬水稻生长和Cd吸收的作用。结果表明,种植三季伴矿景天使三地土壤全量Cd分别下降24.8%、30.9%和58.8%;伴矿景天在富源玄武岩风化物母质发育的土壤上长势最好,与富源土壤肥力相对最高有关;伴矿景天在罗平石灰岩风化物发育的土壤上重金属吸取修复效果最佳,与罗平土壤呈中性、酸化作用更为明显有关,这些差异由土壤母质、养分与重金属有效性等综合影响所致。经伴矿景天吸取修复三季后,全生育期淹水种稻,其糙米和秸秆Cd浓度均大幅降低,可实现糙米Cd安全生产。未经植物吸取修复,旱作处理下水稻糙米Cd存在超标风险。植物吸取修复后种植水稻,再结合水分管理措施,可进一步降低稻米中Cd浓度,实现稻米安全生产,为Cd地质高背景区土壤的农作物安全生产提供理论依据和技术支撑。

厚朴酚环氧树脂涂层的制备及综合防护性能研究

采用联苯结构的生物质原料厚朴酚合成生物基环氧树脂,以柔性聚醚胺固化剂(D230、D400、D2000及T403)进行固化制备生物基环氧抗冲蚀涂层,探究聚醚胺分子量与官能度对厚朴酚环氧树脂力学性能、防腐性能以及抗冲蚀防护性能的影响,阐述厚朴酚环氧涂层抗冲蚀磨损机理。结果表明:D230固化的厚朴酚环氧涂层在3.5%(质量分数)NaCl溶液中浸泡15 d后仍具有较高的阻抗值(1.25×10^(11)Ω·cm^(2));以T403固化可获得高拉伸强度(26.59 MPa)、低摩擦系数(0.373)和磨损率[0.0183 mm^(3)/(N·m)]涂层;D2000固化的厚朴酚环氧涂层在抗冲蚀测试中表现出较低质量损失(244.74 mg)与体积损失(157 mm^(3))。在固/液/气三相流冲蚀作用下,D2000较长的柔性链段,赋予厚朴酚环氧涂层更好的弹性和柔韧性,降低了冲蚀介质的冲击作用,从而表现出优异的抗冲蚀性能。

吸湿解吸循环过程中木材水分吸附特性

【目的】探究吸湿解吸循环过程中木材水分吸附特性,阐释湿度循环对木材细胞壁及其吸着水分子的影响机制,为木材的实际使用和合理开发提供理论依据和数据参考。【方法】以杉木和马尾松木材为试验材料,采用动态水分吸附分析仪在3或5次吸湿解吸循环(0%→95%→0%)过程中实时测定木材水分吸附数据,绘制水分吸着-解吸等温线,借助H-H模型对其吸湿平衡含水率进行非线性拟合分析。【结果】1)吸湿解吸循环前后,木材平衡含水率最大值呈降低趋势,其差值范围为0.21%~1.76%;初次循环过程木材吸湿平衡含水率低于后续循环过程,相对湿度40%~95%时尤为明显;2)随着吸湿解吸循环次数增加,木材单次循环所需时间减少,且降低幅度也明显变小;与块状试样相比,粉末状试样单次循环所需时间较少;3)初次循环过程木材吸湿滞后现象相比后续循环过程更明显,随着循环次数增加,吸湿滞后最大值减小,吸湿滞后率均值增大;4)H-H模型可用于分析吸湿解吸循环过程中木材水分等温吸附,其拟合度(R2)均高于0.996;随着循环次数增加,代表含有单位摩尔吸附位点的绝干木材质量(W)参数呈降低趋势,木材单分子层吸附水最大质量分数呈增大趋势,多分子层吸附水最大质量分数和吸附水总质量分数最大值均呈降低趋势。【结论】随着吸湿解吸循环次数增加,湿度循环对木材细胞壁的影响减弱:木材吸湿性能降低,其平衡含水率最大值呈降低趋势;单次循环所需时间减少;吸湿滞后现象减弱。

考虑电力中长期及现货市场衔接的月内融合交易模式及统一限价研究

在电力市场“中长期+现货”背景下,针对电力中长期与现货衔接问题,探寻高比例新能源入市下月内融合交易市场边界,研究统一限价对社会福利与曲线分解的影响,分析月内融合交易模式对市场衔接的作用。首先,考虑市场中存在的问题,探讨可行的解决方式。其次基于市场预测,构建市场主体的报价与目标函数,结合不平衡电量,构建社会福利最大化市场出清模型,采用A-NSGA-Ⅲ算法进行求解,得到市场出清情况与对应的最优限价范围。最后通过算例验证了统一限价与细分时段的优势,给出了统一限价设定的市场化途径,同时保证了市场主体利益与市场活力,表明了统一限价模式下月内融合交易市场有利于市场主体灵活交易,促进了中长期与现货市场的衔接。

基于事件驱动深度强化学习的建筑热舒适控制

住宅暖通空调系统通常耗用大量能源,同时也极大地影响居住者的热舒适性。目前,强化学习广泛应用于优化暖通空调系统,然而这一方法需要投入大量时间和数据资源。为了解决该问题,提出了一个新的基于事件驱动的马尔可夫决策过程(event-driven Markov decision process,ED-MDP)框架,并在此基础上,提出了基于事件驱动的深度确定性策略梯度(event-driven deep deterministic policy gradient,ED-DDPG)方法,通过事件触发优化控制,结合强化学习算法求解最优控制策略。实验结果显示,与基准方法相比,ED-DDPG在提升学习速度和减少决策频率方面表现出色,并在节能和维持热舒适方面取得了显著成果。经过实验验证,该方法在优化住宅暖通空调控制方面展现出强大的鲁棒性和适应性。

基于多因素分析的密云水库流域径流变化归因

为准确揭示密云水库流域径流变化的物理成因,基于降水、径流非平稳特征诊断结果,采用SWAT(soil and water assessment tool)水文模型,基于Budyko理论的弹性系数法和水量平衡法揭示该流域径流变化原因;对比验证各模型归因结果差异,进一步探究归因方法和基准期选择对流域径流变化归因结果的影响。结果表明:基于Budyko理论的水量平衡方法更适用于水利工程众多、跨流域调水活动频繁的密云水库流域径流变化归因计算;利用该方法进行分析,当基准期长度达到16年及以上时,流域径流变化归因分析结果逐渐趋于稳定,而基准期选取过短会高估人类活动对径流的减水效应;此外,基准期选取靠近研究初始时段时,计算得到人类活动的减水效应相对较大。综合考虑上述各因素的影响,认为人类活动是密云水库流域径流变化的主导因素;在变化期Ⅰ,其减水效应在-128.32%~-119.56%波动,在变化期Ⅱ,其对径流的削减作用为-75.58%~-70.70%。研究结果有助于提升对密云水库流域径流复杂演变规律和物理成因的科学认识。

红笛鲷免疫器官发育组织学观察

【目的】研究红笛鲷(Lutjanus sanguineus)免疫器官发育,为其健康养殖和疾病预防提供理论基础。【方法】从红笛鲷卵出膜开始取样,至出膜62 d,通过石蜡连续切片,H-E染色,进行红笛鲷3个主要免疫器官胸腺、头肾、脾脏发育的组织学研究。【结果与结论】红笛鲷出膜1 d时出现前肾,3 d肾管之间可见造血干细胞;出膜18 d,胸腺和头肾间出现细胞桥,头肾淋巴化;出膜62 d,肾小球仍存在于头肾中,表明头肾既是淋巴器官也是泌尿器官。红笛鲷出膜8 d时出现脾脏原基和红细胞发育;出膜22 d时观察到淋巴细胞;出膜24 d时淋巴细胞显著变多。胸腺是最后一个出现的器官,红笛鲷出膜12 d时出现胸腺原基;15 d时发现胸腺淋巴化。

聚苯胺-氮化硼纳米颗粒复合水性环氧涂层的制备与防腐性能研究

为了提升水性环氧涂层在高盐、高湿海洋环境中的防腐性能和耐久性能,在羟基化的六方氮化硼表面通过原位聚合生长聚苯胺(PANI)得到聚苯胺/氮化硼纳米颗粒(PBN),将PBN作为防腐填料来增强水性环氧涂层的防腐性能。通过傅里叶变换红外光谱(FT-IR)和电子扫描电镜(SEM)对纳米颗粒的结构与微观形貌进行表征,采用电化学测试和中性盐雾试验(NSS)探究氮化硼、PANI改性水性环氧涂层和PBN添加量对水性环氧涂层的防腐性能的影响。结果表明:PANI在BN纳米片表面原位生长形成珊瑚状结构,向水性环氧涂层中添加0.50%(质量分数,下同)PBN后的粘结强度达到6.05 MPa,在3.5%NaCl溶液中浸泡120 h后的腐蚀电流密度(1.99×10^(-9) A/cm^(2))比纯环氧涂层(1.01×10^(-6) A/cm^(2))降低约3个数量级。这归因于添加的0.50%PBN能均匀分散在环氧树脂中,填补涂层的微小空隙并提升对腐蚀介质的阻隔作用,同时PANI具有缓蚀作用,二者协同提高纯环氧涂层的防腐性能。

高比例新能源下电能量与平衡调节服务联合运营与出清机制

随着规模化新能源的接入,电网安全保供形势日益严峻。在此背景下,计及新能源的安全外部成本,提出了电能量与平衡调节服务的联合运营与出清机制。将电能量成本与安全外部成本耦合叠加,通过联合出清,以市场化方式精准组织平衡调节服务;以合理的价格体现电能的能量价值与安全价值,从而给出明确的价格信号促进平衡责任的分担。最后,通过算例分析,验证了所提运营机制在经济性与鲁棒性方面均具有显著优势。

水热环境中马尾松早材和晚材的轴向拉伸力学行为

【目的】探究水热环境中马尾松早材(EW)和晚材(LW)的轴向拉伸力学行为,在生长轮尺度上揭示木材软化行为发生规律,为木材弯曲、塑化、大变形加工等实际应用中工艺参数的选择和优化提供参考。【方法】以马尾松心材区域第17生长轮的早材和晚材为研究对象,采用X射线剖面密度仪测定早材和晚材的绝干密度;利用轮转式切片机在早材和晚材区域的径切面(LR)制取LR-EW和LR-LW组织切片,在早材与晚材区域的弦切面(LT)制取LT-EW和LT-LW组织切片;应用X射线衍射仪和动态力学分析仪在30、40、50、60、70和80℃条件下测定LREW、LR-LW、LT-EW和LT-LW组织切片的微纤丝角、拉伸弹性模量、拉伸强度和拉伸应变速率。【结果】1)晚材的绝干密度(0.836 g·cm^(3))是早材(0.388 g·cm^(3))的2.2倍。任一温度时,早材的微纤丝角大于晚材,弦切面的微纤丝角大于径切面;饱水早材和晚材在径切面或弦切面的微纤丝角均随温度升高而减小。2)30℃时,晚材径切面的拉伸弹性模量是早材的2.1倍,晚材弦切面的拉伸弹性模量是早材的3.3倍。在4种组织切片中,LT-LW的拉伸强度最大,LR-LW的拉伸强度是LR-EW的2.0倍。绝干密度和微纤丝角是影响早材和晚材径切面、弦切面拉伸力学行为的2个关键因子。3)当温度由30℃升至80℃时,早材和晚材在径切面、弦切面的拉伸弹性模量和拉伸强度呈降低趋势,其降幅均为早材大于晚材、弦切面大于径切面。早材和晚材在径切面或弦切面拉伸弹性模量和拉伸强度降幅的拐点温度均为60℃,与木材细胞壁中木质素发生软化有关。4)任一加载速率(0.5、1.0和2.0 N·min^(−1))时,饱水早材和晚材在径切面、弦切面的拉伸应变速率均随温度升高而增大;当温度和加载速率一定时,早材径切面的拉伸应变速率是晚材的2.0倍,早材弦切面的拉伸应变速率是晚材的3.3倍。当加载速率倍增时,早材和晚材径切面、弦切面的拉伸应变速率均呈倍增变化趋势。【结论】饱水早材和晚材在径切面或弦切面的微纤丝角、拉伸弹性模量和拉伸强度均随温度升高而减小(或降低)。与晚材相比,温度变化对早材拉伸弹性模量和拉伸强度的影响更大。温度升高引起微纤丝角变小,抑制拉伸弹性模量和拉伸强度降低,但在60℃及以上水热环境中,木质素软化是引起拉伸弹性模量和拉伸强度降低的主要因素。