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Selective Observations of Chemical Structures of Heat-treated Poly(acrylonitrile) Films at The Surface and Core Regions by Solid-state NMRMa, Jiayang 26 June 2019 (has links)
No description available.
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TIME TO STABILIZATION AS A PREDICTIVE VALUE OF ANTERIOR CRUICATE LIGAMENT AND MEDIAL ANKLE LIGAMENTOUS COMPLEX INJURY IN COLLEGIATE SOCCERKoehler, Matthew David 30 May 2019 (has links)
No description available.
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Assessment of gentle remediation options for trace element-contaminated agricultural land under semi-controlled and field conditionsNeu, Silke 16 September 2020 (has links)
The global soil resources are significantly threatened by pollution. In addition to the existing burden of contaminants in agricultural soils, the increasing anthropogenic input of metal(loid)s, further referred to as trace elements (TE), presents a major public health concern, since it endangers the food security of a rising human population. However, the growing demand for agricultural commodities will increase the pressure on fertile soils. In this context, steering the needed agricultural extensification towards arable TE-contaminated soils (TECS) could protect highly biodiverse or carbon stock land and, thereby, help reach global sustainability targets. The sustainable crop production on TECS requires effective and non-destructive measures to control relevant pollutant linkages. These are offered by gentle remediation options (GRO), the practical adoption of which is scarce across Europe as yet. This study provides different approaches of GRO applied to an agricultural soil in a characteristic post-mining region (Freiberg, Saxony (Germany)) in practical adoption (chapter 2) and under semi-controlled conditions (chapters 3 and 4). Due to severe topsoil contamination by metals (Cd, Pb, and Zn) and As, the pollutant linkages of concern at the study site are food-chain transfer, leaching to the groundwater, and tilling-related dust emissions. The overall aim was to find best management practices for coupling soil remediation with the production of marketable biomass. This was attempted via (i) in situ stabilization, alone (chapter 4.1) or combined with phytoexclusion (chapter 2), (ii) labile TE phytoextraction (chapter 3), and (iii) (aided) phytostabilization (chapter 4.2).
Soil remediation by GRO was assessed with scientifically established (DGT, soil solution; chapter 4.1) and/or legally relevant chemical soil extractions (NH4NO3-solution; chapters 2 to 4) and pH measurements. Additionally, earthworms served as ecotoxicological endpoints (chapter 4.1). Initial soils, earthworms, vegetative and generative biomass produced from each approach, as well as the investigated soil additives, including fertilizers, were microwave-assisted chemically digested (HNO3, H2O2, aqua regia) prior to analysis. All environmental samples were analyzed for TE by inductively coupled plasma mass spectrometry (ICP-MS). Nutrient concentrations in soil additives and selected plant samples were analyzed by inductively coupled plasma optical emission spectrometry (ICP-OES). The measured TE concentrations were evaluated against applicable European and/or national thresholds.
At field (chapter 2), the repeated fertilization with superphosphate and/or lime marl basically attenuated the chemical TE availability over a three years crop rotation of Brassica napus, Triticum aestivum, and Hordeum vulgare. In turn, the simultaneous phytoexclusion by low-accumulating cultivars (LAC) effectively decreased the Cd concentrations in cereal grains (by averagely 21 % in wheat and 39 % in barley). However, straw metals´ accumulation or grain As uptake partly revealed opposing trends among LAC and high-accumulating cultivars (HAC). As investigated under semi-controlled conditions (chapter 3), a sunflower (Helianthus annuus L. mutant inbred line M7 (R3B-F-U/R13M10A; test series R13F-MP)), modified towards enhanced labile TE phytoextraction by chemical mutagenesis, proved less advantageous as pre-crop for winter wheat (Triticum aestivum L. cv. Tiger) than the regionally common winter oilseed rape (Brassica napus L. cv. Lorenz). This resulted from soil alkalinization by rape, whereas sunflower mobilized more TE than it depleted from the rhizosphere. Within in situ stabilization approaches under semi-controlled conditions, a Fe- /Al-rich drinking water treatment residue (WTR), soil-applied at a rate of 1 % (m/m) prior to cultivation of wheat (Triticum aestivum L. cv. Tiger; chapter 4.1) or Szarvasi-1 (Elymus elongatus subsp. ponticus cv. Szarvasi-1; chapter 4.2), decreased the chemical availability of As, Cd, and Pb by up to 77 % , 46 %, and 61 %, respectively. Thereby, it immobilized these hazardous TE increasingly effective over time and better than a Mn-rich WTR or lime marl. The bioassays with wheat and earthworms (Dendrobaena veneta L.) showed, however, that the habitat function for biocenoses benefited more from the Fe-/Al-rich WTR when it was applied at a lower application rate (0.5 % m/m). This resulted from dose-dependent P fixation and TE entries induced by the WTR, to which Szarvasi-1 appeared insensitive. Unlike As, the availability of Cd and Zn to biota in amended soils could not be predicted by any of the applied chemical methods due to endpoint-specific binding of competing cations to the biotic ligand (plant roots, earthworm tissue), and a preferential translocation of Zn over Cd in planta. Among all studied plants, the perennials Szarvasi-1 and cup plant (Silphium perfoliatum L.; chapter 4.2) best excluded the present mixture of TE in shoots, whereby the latter exhibited growth depression. However, only grain biomass of barley and rape, and partly of low-accumulating wheat, produced at the study site presented legally compliant animal feed based on European limit values for Cd and As.
Given the investigated measures´ restricted efficacy to assure forage safety, a land-use change e.g. towards the perennial Szarvasi-1, which provides a continuous plant cover at low tillage and input requirements, possibly accompanied by the monitored reuse of an Fe- /Al-rich WTR, could most promisingly control all above-stated pollutant linkages. Revenues could be generated from energy conversion or valorization in the fibrous material sector. The waste recycling of WTR in TECS, though promising, requires proper characterization, eventual process optimization, and further studies regarding long-term stability to ensure legal compliance and environmental safety. Future research and breeding efforts regarding low Cd cultivars in particular could greatly contribute to safe food or forage production at the majority of moderately contaminated sites.:Table of contents
Danksagung VI
Abstract VII
Zusammenfassung X
List of Figures XIV
List of Tables XVIII
Abbreviations XXII
1 Introduction 1
1.1 The contamination of agricultural soils with trace elements - a global challenge to be tackled at local scale 1
1.2 The study site 5
1.3 Objectives 7
1.4 Structure of the thesis 8
2 Field assessment of conventional fertilizers and cultivars of annual plants 11
2.1 Management of trace element-contaminated agricultural land by in situ stabilization combined with phytoexclusion over a three years crop rotation 11
3 Exploring pre-crop effects of annual oilseeds 37
3.1 Trace elements bioavailability to winter wheat (Triticum aestivum L.) grown subsequent to high biomass plants in a greenhouse study 37
4 The potentials of drinking water treatment residues and/or perennialplants 53
4.1 Trace elements bioavailability to Triticum aestivum and Dendrobaena veneta in a multielement-contaminated agricultural soil amended with drinking water treatment residues 53
4.2 (Aided) phytostabilization of trace elements using cup plant (Silphium perfoliatum L.), or tall wheatgrass (Elymus elongatus subsp. ponticus cv. Szarvasi-1) and soilapplied drinking water treatment residues 77
5 Synthesis 91
5.1 The potential of crop management practices to mitigate food chain transfer of trace elements 91
5.2 The in situ stabilization efficacy under differential experimental conditions 96
6 Future perspectives 101
References 104
List of publications 121
Erklärung 123
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Do Living Shorelines Contribute to the Accumulation of Nutrients, Sediment, and Organic Matter Needed for the Maintenance of Coastal Wetlands?Dutta, Saranee 12 August 2016 (has links)
Living shorelines are designed to address coastal erosion and their use is encouraged over that of hard structures such as sea walls and bulkheads because they provide habitat, improve water quality and stabilize shorelines. Objectives of this study were to: (i) Compare soil Nitrogen [N], Phosphorus [P], Organic Carbon [OC], organic matter (SOM) and soil bulk density between living, hardened and natural shoreline to determine if soil present within living shorelines is comprised of higher SOM and lower bulk density, that encourage marsh growth, as compared to hardened shorelines. (ii) Use an experimental mesocosm to test the effect of shoreline substrate types (living vs hardened vs natural) and nitrogen loading (at four concentration 0, 12, 24, 36 ml) on the growth of Spartina alterniflora. No previous study has documented the growth of Spartina in response to inorganic N loading at various shoreline substrate types. My results show living shoreline has significantly lower soil bulk density [F 2, 138 = 10.79, p <0.01] and higher SOM content than hardened shoreline [F 2, 138 = 10.26, p <0.01]. Combinations of N addition decreased plant’s root-shoot ratio and resulted in increased dry shoot weight. These results indicate that living shoreline is capable of trapping sediments within the nearshore environment, contributing to vertical marsh accretion by accumulation of organic matter, in the face of sea level rise. Findings from this research provide insights to local government, planners, developers and consultants on the benefits of living shoreline structures for the purpose of best shoreline management practice.
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Chest Compression-Related Flail Chest Is Associated with Prolonged Ventilator Weaning in Cardiac Arrest SurvivorsKunz, Kevin, Petros, Sirak, Ewens, Sebastian, Yahiaoui-Doktor, Maryam, Denecke, Timm, Struck, Manuel Florian, Krämer, Sebastian 09 June 2023 (has links)
Chest compressions during cardiopulmonary resuscitation (CPR) may be associated with iatrogenic chest wall injuries. The extent to which these CPR-associated chest wall injuries contribute to a delay in the respiratory recovery of cardiac arrest survivors has not been sufficiently explored. In a single-center retrospective cohort study, surviving intensive care unit (ICU) patients, who had undergone CPR due to medical reasons between 1 January 2018 and 30 June 2019, were analyzed regarding CPR-associated chest wall injuries, detected by chest radiography and computed tomography. Among 109 included patients, 38 (34.8%) presented with chest wall injuries, including 10 (9.2%) with flail chest. The multivariable logistic regression analysis identified flail chest to be independently associated with the need for tracheostomy (OR 15.5; 95% CI 2.77–86.27; p = 0.002). The linear regression analysis identified pneumonia (β 11.34; 95% CI 6.70–15.99; p < 0.001) and the presence of rib fractures (β 5.97; 95% CI 1.01–10.93; p = 0.019) to be associated with an increase in the length of ICU stay, whereas flail chest (β 10.45; 95% CI 3.57–17.33; p = 0.003) and pneumonia (β 6.12; 95% CI 0.94–11.31; p = 0.021) were associated with a prolonged duration of mechanical ventilation. Four patients with flail chest underwent surgical rib stabilization and were successfully weaned from the ventilator. The results of this study suggest that CPR-associated chest wall injuries, flail chest in particular, may impair the respiratory recovery of cardiac arrest survivors in the ICU. A multidisciplinary assessment may help to identify patients who could benefit from a surgical treatment approach.
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Behandling av käkledssjukdomar med stabiliseringsskena eller botulinumtoxin : - En litteraturstudie / Treatment of temporomandibular joint disorders with stabilization appliance or botulinum toxin : - A literature studyPedraza Burian, Irene, Åkesson, Malin January 2022 (has links)
Syfte Syftet med föreliggande litteraturstudie är att jämföra behandlingseffekten av kliniska studier som utgår från patienter med käkledssjukdomar, temporomandibulär dysfunktion, TMD och bruxism där behandlingsalternativen stabiliseringsskena och/eller läkemedlet botulinumtoxin (botox) inkluderats. Material och metod Litteraturstudien genomfördes via PICO-systemet, med litteratursökning i databaserna Medline/PubMed, Web of Science och Scopus. Insamlad data bearbetades genom en granskningsprocess på titel-, sammanfattnings- och slutligen fulltextnivå, utifrån förutbestämda inklusions- och exklusionskriterier. Resultat Två studier uppfyllde urvalskriterierna. Behandlingsterapin med botox och stabiliseringsskena kunde följas under sex månaders tid i båda studierna. Ena studien bestod av 40 patienter som delades in i två grupper, en för varje behandlingsmetod med fyra uppföljnings- och behandlingstillfällen. Den andra studien bestod av 73 patienter som delades in i tre grupper, en för respektive behandlingsmetod och en grupp som inkluderade båda behandlingsmetoderna, med tre uppföljningstillfällen. Antal enheter och placering av botoxinjektioner skilde sig åt i studierna, tillika antal timmars användning av stabiliseringsskena. Studierna presenterade trots skillnader liknande resultat. Slutsats Behandling med stabiliseringsskena är inte nödvändig för patienter som behandlats med botulinumtoxin, eftersom de statistiska resultaten inte påvisade någon större skillnad i effekt. Behandling med botulinumtoxin och dess effekt på patientens besvär beror på antal enheter av läkemedlet och placering vid injektion samt i jämförelse med omfattningen av hur mycket patienten använder stabiliseringsskenan. Botulinumtoxin kan användas som behandlingsmetod när patienten av olika anledningar inte kan använda stabiliseringsskena. / Purpose The purpose of this literature study is to compare clinical studies that have included the treatment options of using stabilization appliances and/or medication with botulinum toxin. The included studies must have included and treated patients with temporomandibular disorders, temporomandibular dysfunction, TMD and bruxism. Material and method The literature study was executed based on the PICO system and through searches in the databases Medline/PubMed, Web of Science and Scopus. Subsequently, a review process was carried out at title, abstract and finally full text level, based on predetermined inclusion and exclusion criteria. Results Two studies met the selection criteria. The treatment therapy could be followed for a period of six months in both studies. One study consisted of 40 patients who were divided into two groups, one for each treatment method with four follow-up and treatment sessions. The second study consisted of 73 patients who were divided into three groups, one for each treatment method and one group that included both treatment methods and three follow-up sessions. Units and location of botulinum toxin injections and the hours of use of the stabilization appliance differed slightly in the two studies. However, the studies reported similar outcomes. Conclusion The treatment with stabilization appliance is not necessary for patients who are being treated with botulinum toxin due to non-statistical significance reported. The outcome of botulinum toxin treatment may depend on the location and number of units of the medication in comparision to the extent to which the patient uses the stabilization appliance. Botulinum toxin may gain as a treatment method when the patient is unable to use a stabilization appliance for various reasons.
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Testování posturální stabilizace motoriky ve vztahu k bolesti zad a evaluace dysfunkce posturálního řízení motoriky metodou posturální somatooscilografie / Testing the postural stabilization of the movement system and evaluating the dysfunction of the postural cybernetic of the movement system by a new method postural somatooscilographyRašev, Eugen January 2011 (has links)
Testing the postural stabilization of the movement system and evaluating the dysfunction of the postural cybernetic of the movement system by a new method postural somatooscillography Abstract: Introduction: For the objectification of the structural damages in the musculoskeletal system there are many research methods and imaging techniques. For the investigation of the stabilization of the locomotion system a simple, reliable method for the clinical and instrumental evaluation of the pain-body is missing so far. These methods probably would include the cause of the dysfunction of the stabilizing mechanisms in vertically integrated persons. Therefore I introduce a Postural Somatooscillography in this work, which is a new kind of posturography on a Posturomed surface that can be unstable in a metered way. Second, a new technique of "provocation test" (Step/Stand) is introduced here. In this test, standardized claims to the increased postural stability and so on the nature of the cooperation of the intersegmental muscles and the superficial polysegmental muscles are made evident. Either caused by a good segmental stabilizing a good economic posture, without pain, or non- economic activation of polysegmental muscles caused postural related pain in these congested superficial muscles. Objectives: My aim is the...
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Mechanical properties of excavated sulfur rich soil stabilized with cement - A laboratory and field experimentZiagharib, Alaleh January 2023 (has links)
Sulfide soils are silty soils, often found in saturated conditions, under the groundwater level. Characteristics of these soils, including particle size distribution and consistency limits along with chemical composition and environmental properties, cause excavation to be necessary for construction purposes. The excavated sulfide soil usually is transported and deposited in landfills. These soils are either deposited in saturated conditions or chemical buffers are added to the soil to prevent acidification. Special conditions of these landfills complicate the disposal procedure and the landfill maintenance which makes those financially expensive. Reusing sulfide soil in construction is a solution to reduce the expenses related to the management of sulfide soils. Since the mechanical properties of these soils are not suitable for construction purposes, the first step is to improve soil characteristics to the level that fulfills the needs of construction applications. One solution to improve the mechanical properties of the soil is adding a binder to the soil. The main focus of the research was to improve the mechanical properties of soil. The research activities were divided into two parts. The first part was conducted in a laboratory environment to develop mixtures, while the second focused on transferring the results to field conditions. The laboratory tests included mixing soil and binder i.e., cement was added to the soil at different percentages to evaluate the soil improvement. An unconfined compressive strength (UCS) test was conducted on the stabilized sample to evaluate the efficiency of the stabilization. The resultsof UCS for the stabilized samples were compared. Since the soil contains a high amount of water, the traditional sample preparation was not suitable. Therefore, an alternative method was developed and evaluated. Moreover, the effect of curing time on the strength and consistency limit of stabilized samples was evaluated. At last, the effect of different variables, including porosity, binder content and initial water content, on the UCS of soil was investigated to identify potential correlation between UCS and different soil variables. The results of the tests showed that adding a binder, regardless of the type of sulfide soil, positively affects the UCS of prepared samples and increasing the curing time increased the UCS of the samples. At higher cement content, the effect of curing time was more significant. Also, it was shown that at higher water content, the effect of binder is lower in comparison with the same soil at lower water content. By lowering the water content, the strength of stabilized soil reaches a maximum and drying further the soil, below the optimum water content, led to strength reduction. A correlation between UCS of sample and porosity/binder ratio was employed to predict the strength behavior of stabilized soil based on variables such as porosity, initial water content and binder dosage. In order to evaluate if laboratory results can be applied to geotechnical applications, the second part of this research included a field mixing experiment for a large-scale mixture of soil and cement. The effect of the mixing procedure with common equipment on the homogeneity of industrial-size mixture was investigated. A sampling strategy for collecting representative samples of mixture was selected and assessed. the number of mixing steps and the effect of binder dosage on the uniformity of samples were studied. Results of UCS of samples prepared from field and laboratory mixture were compared and evaluated. A field evaluation was conducted to determine the quality of the mixture and how many mixing steps are required to reduce variability between samples. Two different percentages of binder were added to the 5 Tons of soil. The UCS test samples were prepared from the soil-cement mixture in the same way as they were prepared in the laboratory and cured for a specific time. The UCS test was conducted on cured samples. The test results were compared to evaluate the mixture homogeneity in the field. The results showed that homogeneous mixtures can be obtained in the field with the available equipment. Assessing the sampling strategy showed that increasing the sampling sections from 5 to 12 and preparing single UCS sample from the collected soil provides representative samples from the soil mixture pile. Additionally, it was shown that by increasing mixing steps from 2 to 3, it was possible to eliminate samples with notable lower strength than average UCS. A greater number of mixing steps improves homogeneity while reducing the average UCS. It was found that mixing soil and binder in the laboratory improves strength better than mixing them in the field. When applying laboratory results to field design, this point must be taken into account.
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Cement Stabilization of Aggregate Base Materials Blended with Reclaimed Asphalt PavementBrown, Ashley Vannoy 12 May 2006 (has links) (PDF)
The purpose of this research was to investigate the effects of reclaimed asphalt pavement (RAP) content and cement content on the strength and durability of recycled aggregate base materials. Specifically, the unconfined compressive strength (UCS) and final dielectric value in the Tube Suction Test (TST) were measured in a full-factorial experimental design including five RAP contents, five cement contents, and three replicate specimens of each possible treatment. Specimen mixtures consisted of 0, 25, 50, 75, or 100 percent RAP and 0.0, 0.5, 1.0, 1.5, or 2.0 percent Type I/II Portland cement. Both the RAP and base materials were sampled from the I-84 pavement reconstruction project performed in Weber Canyon near Morgan, Utah, during the summers of 2004 and 2005. The laboratory testing procedures consisted of material characterizations, specimen preparation, and subjection of the specimens to strength and durability testing, and the data were evaluated using analysis of variance (ANOVA) testing. Both the RAP and base materials included in this research were determined to be non-plastic, and the AASHTO and Unified soil classifications for the RAP material were determined to be A-1-a and SM (well-graded sand with gravel), respectively, and for the base material they were A-1-a and SW-SM (well-graded sand with silt and gravel), respectively. The optimum moisture contents (OMCs) for the blended materials were between 5.6 and 6.6 percent, and maximum dry density (MDD) values were between 129.7 and 135.5 lb/ft3. In both cases, decreasing values were associated with increasing RAP contents. The results of the ANOVA performed on the UCS data indicate that UCS decreases from 425 to 208 psi as RAP content increases from 0 to 100 percent and increases from 63 to 564 psi as cement content increases from 0.0 to 2.0 percent. Similarly, the final dielectric value decreases from 14.9 to 6.1 as RAP content increases from 0 to 100 percent and decreases from 14.0 to 5.8 as cement content increases from 0.0 to 2.0 percent. With design criteria requiring 7-day UCS values between 300 and 400 psi and final dielectric values less than 10 in the TST, the results of this research suggest that milling plans should be utilized to achieve RAP contents in the range of 50 to 75 percent, and a cement content of 1.0 percent should be specified for this material. Cement contents less than 1.0 percent are not sufficient to stabilize the material, and greater cement contents may cause cracking. Because control of the actual cement content in the field depends on the contractor's equipment and skill, inspection protocols should be implemented during construction to ensure high-quality work. Additional recommendations are associated with the construction process. The specimens prepared in this research were compacted to relative densities of 100 percent using modified Proctor energy. Therefore, field compaction levels must approach these density values if the same material properties are to be achieved. In addition, all specimens tested in this study were cured at 100 percent relative humidity. Following compaction in the field, cement-treated layers should be moistened frequently during the first few days after construction or promptly sealed with a prime coat or wearing surface to ensure that the cement continues to hydrate. Variability in RAP and cement contents should also be minimized to achieve consistent material properties.
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Assessment of the Tube Suction Test for Identifying Non-Frost-Susceptible Soils Stabilized with CementCrook, Amy Lyn 21 October 2006 (has links) (PDF)
Frost heave is a primary mechanism of pavement distress in cold regions. The distress exhibited is dependent on the frost susceptibility of the soil within the depth of frost penetration, the availability of subsurface water, and the duration of freezing surface temperatures. Cement stabilization is one technique used to mitigate the effects of frost heave. The tube suction test (TST) is one possible method for determining the frost susceptibility of soils in the laboratory. The purpose of this research was to assess the utility of the TST for identifying non-frost-susceptible (NFS) materials stabilized with cement. This research investigated two aggregate base materials from Alaska that have exhibited negligible frost susceptibility in the field. The unconfined compressive strength (UCS), final dielectric value in the TST, and frost heave at three levels of cement treatment and in the untreated condition were evaluated for both materials. The data collected in this research indicate that, for the two known NFS materials included in this study, the TST is a good indicator of frost heave behavior. The total heave of the untreated materials was approximately 0.15 in. at the conclusion of the 10-day freezing period, which classifies these materials as NFS according to the U.S Army Corp of Engineers. Both materials had final dielectric values of less than 10 in the TST, indicating a superior moisture susceptibility rating. The results of this research suggest that the TST should be considered for identifying NFS materials, including those stabilized with cement. Additional testing should be performed on known NFS materials stabilized with cement and other additives to further assess the validity of using the TST to differentiate between frost-susceptible and NFS materials. Consistent with previous studies, this research indicates that, once a sufficient amount of cement has been added to significantly reduce frost heave, additional cement has only a marginal effect on further reduction. Therefore, to avoid unnecessary expense in construction, the minimum cement content required for preventing frost heave should be identified through laboratory testing and specified by the engineer. In this work, UCS values ranging between 200 psi and 400 psi after a 7-day cure were typically associated with this minimum cement content. Because the scope of this research is limited to two aggregate base materials, further testing is also necessary to validate this finding.
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