Application of apical negative pressure irrigation in the nonsurgical treatment of radicular cysts:A case report

BACKGROUND Radicular cysts are one of the most common odontogenic cystic lesions found in the jaw.Nonsurgical treatment of large radicular cysts is a topic of ongoing debate,and there is still no clear consensus on the most effective therapies.The apical negative pressure irrigation system aspirates the cystic fluid and releases the static pressure in the radicular cyst,representing a minimally invasive approach for decompression.In this case,the radicular cyst was in close proximity to the mandibular nerve canal.We used nonsurgical endodontic treatment with a homemade apical negative pressure irrigation system and the prognosis was good.CASE SUMMARY A 27-year-old male presented to our Department of General Dentistry with complaints of pain in the mandibular right molar when chewing.The patient had no history of drug allergies or systemic disease.A multidisciplinary management approach was designed and included root canal retreatment with a homemade apical negative pressure irrigation system,deep margin elevation and prosthodontic treatment.According to a 1-year follow-up period,the patient showed a favorable outcome.CONCLUSION This report reveals that nonsurgical treatment with an apical negative pressure irrigation system may provide new insights into the treatment of radicular cysts.

Two-way coupling of unsaturated-saturated flow by integrating the SWAT and MODFLOW models with application in an irrigation district in arid region of West China

This paper presents the realization of two-way coupling of the unsaturated-saturated flow interactions of the SWAT2000 and MODFLOW96 models on the basis of the integrated surface/groundwater model SWATMOD99, and its application in Hetao Irrigation District （HID）, Inner Mongolia, China. Major revisions and enhancements were made to the SWAT2000 and MODFLOW models for simulating the detailed hydrologic budget and coupled unsaturated and saturated interactions, and irrigation canal hydrology for the HID. The simulation results of seasonal groundwater recharge to and evaporate from the shallow groundwater, and the annual water budget over the district are presented and discussed. The results implied the necessity of two-way coupling of the unsaturated-saturated interactions when groundwater is shallow, and the feasibility of making comprehensive use of the information coming from both the surface water and groundwater models to make a more physically-based assessment of the coupled interactions.

The Role of Traditional Irrigation Canals in a Long Term Environmental Perspective A Case Study in Southern France： The Durance Basin

The agricultural sector is often considered to be the largest water consumer and the policy aimed at saving irrigation water exists across Europe. The flip-side of such policy, however, is the disappearance of traditional irrigation canals since farmers are encouraged to turn to drip irrigation and overhead irrigation gradually. Given this, we would like to argue that traditional irrigation canals need to be reexamined. Such canals are not only built aquatic infrastructure, they are also the product of a culture and social relationship with water in the Mediterranean region. Canals form a complex system which is driven by environmental, economic and social factors. Our sociological and environmental research in Provence （and around the Durance basin more specifically） points up how the very dense territorial network of gravity-fed canals is useful in water management, as well as in other shared uses over the long-term. The findings underscore the positive environmental role played by these historical and anthropogenic constructions. They contribute to refilling the aquifer and also act as a valuable environmental good and service （e.g., run-off regulation, biodiversity, landscape, recreation, etc.）. Further, several local actors have underscored their role as part of an intangible cultural heritage and as important for the area＇s economic and social development. Such canals play a central role in sustainable development since beyond their productive role in agriculture, they play a social role （new uses） and an ecological role （as reservoirs for biodiversity and ecological corridors）.

Effect of Reference Conveyance Parameter Usage on Real Time Canal Performance: The Case of Fentale Irrigation Scheme in Ethiopia

In designing a canal system, a major problem is to decide what conveyance parameter to apply in the calculations. Since basic knowledge on this subject is lacking, it is usually taken from literatures. Most of the irrigation projects in Ethiopia are found to work below their expectation. One of the main reasons is the conveyance parameters variation from the expected (design) value which ultimately affects the envisioned conveyance efficiency. To evaluate this variation, Fentale irrigation scheme was used as case study. The conveyance efficiency used at the design stage was 80%, which was within Food and Agricultural Organization of the united nations recommendations;while the field survey value was 17%. Such huge variation was due to the fact that the assigned conveyance parameter values (roughness coefficient, hydraulic radius and bed slope) no longer represent the current situation of the scheme. Such variation has resulted in increase in the depth and top width of the water surface which further resulted in 13% and 3% increase in wetted perimeter and top width of the canal, respectively. Thus this study suggests that conveyance parameters shall be derived from history of existing irrigation schemes in a country, rather than adopting it from standard literatures. As such construction quality, maintenance activities and technological transfer activities in a country shall be seen in deciding the conveyance parameters. The study also suggests that the ever increasing water shortage in an irrigation project could be managed by proper maintenance of the entire irrigation system.

Balance of Irrigation Water in Jinghui Canal Irrigation District of China

Jinghuiqu Canal Irrigation District is an old irrigation area with a long history.Due to natural and man-made factors,the inflow and rainfall of the irrigation area are decreasing,which seriously affects agricultural production water in the irrigation area and constantly threatens the safety of irrigation water in irrigation area.In this paper,natural and man-made factors of affecting irrigation water in irrigation area are analyzed,and it is proposed that main channels of solving safety of irrigation water are enhancing the utilization of canal water and optimizing the allocation of canals and wells.

WELL-CANAL MIXED IRRIGATION REGULATION MODEL FOR AMELIORATING SOIL SALINIZATION

It is an important way for salinized soil amelioration to practise comprehensive irriga-tion-drainage scheme with canal,well and drain togather and to utilize surface and groundwaters jointly. In more serious salinized region, well-canal mixed irrigation can improvethe irrigated water quality. To fulfil water quality requirements, it is necessary to

Determination of Irrigation Supply Efficiency in Challenging Environment Case Study of Bal’ad District, Middle Shabelle Region in Somalia

The paper aims to determine the irrigation water supply efficiency of different irrigation methods used in the challenging environment of Bal’ad district in Somalia. Data was collected from the literature, field visits using field records and scheduled interviews, GPS coordinates and from ancillary information, such as remote sensing images and existing national maps. A comparison was done by use of secondary sources, such as academic journals using information from authorities on irrigation and water loss. Sampling was done by use of Snow balling. The results highlighted response rate for farmers being 80% while that of NGO employees is 75.76%. According to the results, the main ways through which irrigation water is lost is through: evaporation;seepage through the canal bunds;overtopping the bunds;overflow losses and overwatering with the average field application efficiency of 25% and conveyance efficiency of 30%. These generated a scheme irrigation efficiency of 7.5% which is poor for surface irrigation prevalent in the study area. The loss of irrigation water was found to be reduced by the following: daily supervision;proper maintenance;water allocation to farmers;good management;lining of canals;management of irrigation methods;ongoing evaluation;good land preparation;and training farmers.

Integrated Water Resource Assessment of Irrigation System of Haryana

Agriculture is the major activity in the state of Haryana and large volume of water is required to meet the irrigation demands of the crops grown. But, there is limited water availability in the state. Haryana receives water from Yamuna River and Bhakra system. Sowmelt, rainfall and groundwater are main sources of water in the catchment. It is essential to integrate the manmade canal system with hydrological system. This paper focuses on integrated hydrological modeling framework to conceptualize the system and to assess the Water Resources of the state. Snowmelt and Rainfall runoff modeling using GR4JSG model were combined to model the inflows to the irrigation system of Haryana. Irrigator canal model of eWater Source has been used to generate water demands from crops grown. The water balance and water use efficiency have been worked out for each district of Haryana. The hydro climate input data, stream flows, crop data and soil data have been used in the study. The flows modeled at Tuini (P), Yashwant Nagar, Bausan, Haripur, Poanta and HKB sites were compared with the observed flows. The objective function of NSE Daily and log Flow duration was used for model calibration and validation at various locations up to Mathura, the outlet of the study area. The value of the objective function at Mathura was 0.54, a fairly good value. The results of the Irrigator canal model have shown that all the Inflows, Outflows and the Utilizations of water have been properly balanced for each district. The water use efficiency of districts varies from 27% to 59%. The overall water use efficiency for Haryana canal system has been calculated as 39%. This is low value indicating excess water is being extracted to meet the water demands.

Frequent Breaches in Irrigation Canals in Sindh Pakistan

Every year, a number of breach failures occur in Irrigation Canals in Sindh. Those failures cause displacement of thousands of people, destruction of properties, land, and damage to costly crops that worth millions Rupees. In addition to that, breach failures also can cause water shortages when the failure occurs during the peak demand period. There are various causes of embankment failures which include overtopping, internal erosion, structural defects and piping. State of art for breach failures is presented in this paper and suggestions for prediction of breaches in context to canals in Sindh are discussed. Seepage and slope stability analyses are recommended for a long-term breach predictions.

An in vitro study on the efficacy of removing calcium hydroxide from curved root canal systems in root canal therapy

To compare the efficacy of various irrigants(citric acid, ethylenediaminetetraacetic acid(EDTA) and Na OCl) and techniques in removing Ca(OH)2in two types of curved root canal systems, simulated root canals with specific curvatures were used to investigate the effects of different irrigants and instruments on Ca(OH)2removal. The optimal methods were verified on extracted human teeth. Simulated root canals were assigned to one of two groups based on the irrigation solution: 10% citric acid or2.5% Na OCl. Each group was divided into four subgroups according to the technique used to remove Ca(OH)2. The percentage of Ca(OH)2removal in different sections of root canals was calculated. On the basis of the results obtained for the simulated canals, 10% citric acid and 17% EDTA were applied to remove Ca(OH)2from the extracted human teeth with curved root canal systems. The teeth were scanned by micro computed tomography to calculate the percentage of Ca(OH)2removal in the canals.In simulated root canals, we found that 10% citric acid removed more Ca(OH)2than 2.5% NaOCl in the 0–1 mm group from the apex level(Po0.05). Ultrasonic and Endo Activator activation significantly removed more Ca(OH)2than a size 30 K file in the apical third(Po0.05). However, there were no significant differences in any sections of the canals for 10% citric acid or 17%EDTA in removing Ca(OH)2in extracted human teeth. We concluded that it was effective to remove residual Ca(OH)2using the decalcifying solution with Endo Activator or Passive Ultrasonic Irrigation in a curved root canal system. A protocol for Ca(OH)2removal was provided based on the conclusions of this study and the methods recommended in previous studies.

Efficacy of Solution Form of Ethylenediaminetetraacetic Acid on Removing Smear Layer of Root Canal at Different Exposure Time In Vitro

Summary： This study was aimed to evaluate the effectiveness of solution form of 17% ethylenediaminetetraacetic acid （EDTA） on removing smear layer of root canals at different exposure time periods and to provide scientific basis for EDTA as a choice of root canal irrigation in clinical practice. Twenty-five single-rooted teeth were randomly divided into 5 groups： control group （group A） was given 2.5% NaOC1, and 4 experimental groups were given 2.5% NaOC1 and 17% EDTA, including groups B, C, D and E with exposure time of 1, 3, 5 and 7 min, respectively. After preparation of the root canals, the teeth were split along their longitudinal axis, and the root sections were examined under scanning elec- tron microscope for evaluation of smear layer removal and erosion on the surface of the root canal walls. The specimens in group B showed presence of smear layer on the walls of the root canal with no statistical difference from that in group A （P〉0.05）. In groups C and D, partial removal of smear layer was obtained, and there was no significant difference between the two groups （P〉0.05）, but there was significant difference in removal of smear layer between group C and group B （P〈0.05）. Root canal walls in group E specimens showed almost complete removal of smear layer, and the removal of smear layer was significantly different from that in group D （P〈0.01）. There was no significant change in the structure of the surface of root canal for each sample. It was concluded that combined irrigation with 17% EDTA and 2.5% NaOC1 could remove the smear layer with no significant alteration in dentinal structure when the chelating agent was applied for 7 min. At 3 and 5 min of application, partial removal of smear layer was observed and at 1 min negligible removal of smear layer was achieved.

Effect of Water Resources Allocation on Groundwater Environment and Soil Salinity Accumulation under Climate Change

The combined surface and groundwater allocation practice by wells and canals had contributed to the safety of groundwater environment and agriculture sustainable production. The typical area in the People＇s Victory Canal irrigation district was taken as a case, drawing together the irrigation district agriculture water consumption and precipitation from 1954 to 2014 in the People＇s Victory Canal irrigation district, ratios of surface to groundwater irrigation amount, dynamic of groundwater depth and hydrochemical characteristic of groundwater from 2008 to 2014 in the research area, the relationship between groundwater depth and ratio of surface to groundwater irrigation amount was analyzed, in order to ascertain the influence of precipitation on ratios of surface to groundwater irrigation amount and its effect on soil and groundwater environment. The results indicated that positive correlation between the ratios of surface to groundwater irrigation amount and annual precipitation was appeared, affected by climate change, average irrigation amount from surface in the recent 5 years was 2.90 x 108 cubic meters, accounted for 75.52% of total irrigation amount, on the other hand, decreasing tendency of precipitation was obvious, and groundwater depth dynamic in upstream of the branch canals was more dramatic than downstream because of surface water irrigation infiltration, under the unified condition of water use efficiency, ratio of surface to groundwater irrigation amount was negative correlation with area of the groundwater depth beyond 11 m, meanwhile, groundwater depth demonstrated negative correlation with the ratio of surface to groundwater irrigation amount, moreover, alkaline trend of groundwater hydrochemistry during the normal season in the research area was obvious because of phreatic evaporation and the agricultural irrigation from wells, along with irrigation from surface inflow of Yellow River, quality of groundwater hydrochemistry during the dry season was ameliorative greatly. Consequently, it was very important to the agriculture sustainable production that well-canal combined irrigation patterns alleviated extremely alkaline trend of the groundwater hydrochemistry and played a positive role of root layer soil salinity leaching.

井渠双灌模式下黄河下游灌区水资源优化配置

【目的】探究井渠双灌模式下黄河下游灌区水平衡特征,分析渠水和地下水补灌的利用量和利用时机对作物水分消耗和产量的影响,为黄河下游灌区多水源综合利用和优化配置提供科学依据。【方法】基于散耗型水文模型对井渠双灌模式下的黄河下游灌区水平衡特征进行模拟,结合作物水分生产函数Jensen模型分析不同水源优化配置下冬小麦和夏玉米产量变化。【结果】在现状井渠双灌模式下,4月上旬、5月中下旬、6月上旬、7月下旬和8月上旬存在显著的水分亏缺,现状模式下10月中旬抽取地下水补灌的利用效果不佳,现有灌溉模式与纯渠水灌溉模式对作物产量的影响差别不大。冬小麦拔节期的相对产量对地下水补灌的响应最为敏感,夏玉米在抽穗期的相对产量对地下水补灌的响应最为敏感。对于冬小麦,在拔节期抽取70 mm地下水进行1次补灌即可实现显著增产,地表水与地下水适宜的利用比例为5.25∶1;对于夏玉米,在抽穗期抽取70mm地下水进行1次补灌即可实现显著增产,地表水和地下水适宜的利用比例约为4.4∶1。【结论】黄河下游灌区适宜的地下水补灌时机和利用量会对作物产量产生影响,建议在冬小麦拔节期抽取70 mm地下水进行1次补灌,在夏玉米抽穗期抽取70 mm地下水进行1次补灌,最适宜提升作物产量。

70%乙醇去除弯曲根管内氢氧化钙的效果评价

目的:应用显微CT(micro-computed tomography,Micro-CT)评价不同冲洗液联合声波荡洗对后牙弯曲根管内氢氧化钙的清除效率。方法:收集2023年10月—2024年2月在上海交通大学医学院附属第九人民医院口腔综合科门诊拔除的磨牙20颗(根管数n=48),按照根管治疗标准流程,使用镍钛器械完成预备后,在根管内置入氢氧化钙。1周后,根据不同冲洗方法将样本随机分入6组(n=8),即先分为次氯酸钠组、17%EDTA组和70%乙醇组3组,每组再分为使用或不使用声波荡洗2个亚组。冲洗前、后使用Micro-CT重建根管系统,使用不同颜色标记独立根管,计算根管各段氢氧化钙体积,比较各组氢氧化钙清除率。采用SPSS 19.0软件包对数据进行统计学分析。结果:6组均无法去净根管内氢氧化钙,70%乙醇组去除氢氧化钙后剩余体积显著小于其余2组(P<0.05)。在乙醇亚组内,声波震荡组与注射器组去除效率无显著差异(P>0.05)。结论:70%乙醇能增加弯曲根管内氢氧化钙去除效率。

掺气摇臂喷头喷灌的综合性能评价与配置优化

掺气摇臂喷头具备气液两相射流、低压喷灌性能好等特性。为得到20PY2型该喷头的最优参数配置,基于组合喷灌试验,通过主成分分析法进行综合评价与配置优化。配置参数为工作压力、掺气管伸缩量和组合间距倍数,评价指标为平均喷灌强度、组合喷灌均匀度、喷洒能耗等。结果表明:平均喷灌强度与组合喷灌均匀度、喷洒能耗呈正相关,与有效喷灌面积和水利用系数呈负相关,其中,相关性最强的指标为平均喷灌强度和组合喷灌均匀度;选择特征根分别为2.534、1.322的两个主成分,第一主成分受平均喷灌强度、组合喷灌均匀度和有效喷洒面积影响大,第二主成分受喷洒能耗影响大;掺气摇臂喷头应选择相对较高的工作压力;最优的参数配置方案:工作压力250 kPa、掺气管伸缩量2 cm和组合间距倍数1.1,为掺气摇臂喷头的田间应用提供指导。

折射式微喷头水力性能试验及工作参数优选

为探究折射式微喷头水力性能并确定其适宜的工作参数,开展微喷头水力性能测试,明晰不同工况下单个微喷头水量分布特征,分析其流量、射程、喷灌强度随工作压力和喷嘴直径的变化趋势。探究在正方形和正三角形组合方式下,工作压力和组合间距变化对喷灌均匀系数CU的影响,基于主成分分析方法,统一相关评价指标,建立折射式微喷头工作参数综合评价模型。结果表明:单喷头的流量、喷灌强度均与工作压力呈正相关,而射程随压力的变化并不明显;正方形和正三角形两种组合方式下,组合间距变化对CU产生的影响明显大于工作压力和组合方式;依据各工况评分高低,对微喷头最优工况做出合理选择,实例应用的结果表明:折射式微喷头最优工况为正三角形组合,工作压力0.25 MPa,组合间距0.4 m。

刚性约束下人民胜利渠灌区水资源优化配置方案研究

为解决人民胜利渠灌区水资源利用的“瓶颈”制约问题,创新性地构建了基于刚性水资源约束的灌区水资源优化配置模型,并引入高效的改进型非支配遗传算法(NSGA-II)求解,生成规划水平年2035年不同供水保证率的100组优化配置方案。采用结合层次分析法(AHP)与CRITIC权重法的综合权重计算方法,利用TOPSIS法进行方案排序与优选,从众多可行方案中遴选出最优配置方案,为人民胜利渠灌区水资源节约集约利用提供参考,并有助于实现水资源的可持续利用。

人民胜利渠灌区水资源安全综合评价

基于灌区水资源安全理论,构建水量、用水效率、生态3个准则层,选取水资源总量、每公顷农田灌溉水量、万元工业增加值用水量、生态用水量占比等10个指标,并依据人民胜利渠灌区2015—2020年社会、自然、经济和水资源等相关数据及统计资料,采用熵权法-层次分析法评价模型,对人民胜利渠灌区水资源安全进行综合评价。结果表明:2015年、2016年和2020年人民胜利渠灌区水资源处于基本安全状态,2018年和2019年处于安全状态,2017年处于不安全状态。通过深入辨识分析影响人民胜利渠灌区水资源安全的各项指标,发现提升水资源利用效率、推广节水灌溉技术以及实现水资源供需均衡,是确保人民胜利渠灌区水资源安全的关键。

Effects of irrigation water regime, soil clay content and their combination on growth,yield,and water use efficiency of rice grown in South China

To investigate the effect of irrigation regime,soil clay content and their combination on growth,yield,and water productivity of rice,a shelter experiment was conduct using Randomized Complete Block Design(RCBD)with a factorial arrangement of treatments with four replications.Irrigation regime was the main treatment investigated,set in three levels as R(30 mm-100%)(100%of saturation and 30 mm flooded),R(30 mm-90%)(90%of saturation and 30 mm flooded)and R(30 mm-70%)(70%saturation and 30 mm flooded),respectively.The sub-treatment was soil type,set in three levels as 40%,50%and 60%clay content,respectively.Results showed that irrigation regime and soil clay content had significant effects on growth,yield and water productivity of rice.However,their combination showed no significant impact on panicles number,root biomass,harvest index and irrigation water productivity.Higher soil clay content results in increase in growth,yield,and water productivity of rice.The total water consumption during R(30 mm-100%)was higher than that during R(30 mm-90%)and R(30 mm-70%)because the latter two saturation levels led to the cracking of soil and decrease of total number of irrigations.Cracks were consistently getting more serious with the reduction in soil water content and the increase in soil clay content.Cracks in soil will preferentially become the major routes of water losses,thus water percolation during R(30 mm-70%)was higher than that during R(30 mm-90%)and R(30 mm-100%)after each irrigation event.The total water use under R(30 mm-70%)exceeded the water consumption under R(30 mm-90%)due to the great amount of soil cracking as well as the excessive volume of standing water depth.Considering water consumption and grain yield,the following conclusion can be reached:(i)The reduction in water consumption was greater than the reduction in grain yield in the case of drying soil 10%below saturation before reflooding.(ii)The reduction in water consumption was less than the reduction in grain yield in the case of drying soil 30%below saturation before reflooding;(iii)The increase in water use was greater than the increase in grain yield in the case of maintaining soil moisture at 100%of saturation before reflooding.Therefore,the water use efficiency was recorded in the order of R(30 mm-90%)>R(30 mm-100%)>R(30 mm-70%).

Coupling model and optimal combination scheme of water,fertilizer,dissolved oxygen and temperature in greenhouse tomato under drip irrigation

Water-fertilizer coupling technology has been widely used in the world.Poor soil aeration,low temperature or high temperature can affect the rate of nutrient uptake by crop roots.Aiming at the interaction between water,fertilizer,dissolved oxygen and temperature(WFOT)coupling model and irrigation flux of tomato in greenhouse,using these four factors with a five-level uniform-precision rotatable central composite design,a mathematical model was established among the four factors affecting tomato yield in a greenhouse,and the optimal combination scheme of WFOT was obtained.Within the test range,tomato yields increased with increasing irrigation quotas(X_(1)),fertilization amount(X_(2)),dissolved oxygen(X_(3))and geothermal pipe water temperature(X_(4)).The magnitude of the effect of each factor of WFOT on tomato yield was in the following order:X_(1),X_(2),X_(4),X_(3)(spring and summer),and X_(1),X_(3),X_(2),X_(4)(autumn and winter).The interaction between high water-low heat and low water-high heat were beneficial for yield increase(spring and summer),the high fertilizer-low heat and low fertilizer-high heat interactions were beneficial to yield increase(autumn and winter).If WFOT agronomic measures were adopted according to the 95%confidence interval,there was a 95%probability that the spring-summer tomato yield will be higher than 89902 kg/hm^(2).The WFOT coupling scheme was X_(1)of 4808-5091 m3/hm^(2),X_(2)(N-P_(2)O_(5)-K_(2)O)of 171-57-84 to 186-62-89 kg/hm^(2),X_(3)of 7.9-8.2 mg/L,and X_(4)of 34.9°C-37.0°C.There was a 95%probability of tomato yield higher than 85209 kg/hm^(2)in autumn and winter,and the WFOT coupling scheme was X_(1)of 5270-5416 m3/hm^(2),X_(2)(N-P_(2)O_(5)-K_(2)O)of 151-50-76 to 167-56-82 kg/hm^(2),X_(3)of 8.0-8.2 mg/L,and X_(4)of 34.1°C-36.2°C.Overall,and the model had a very good simulation effect,with application value.The relative error between spring-summer and autumn-winter yields ranged from 1.12%to 25.34%.The results of the study can provide a theoretical basis for improving the quality and efficiency of greenhouse tomatoes.