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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

The adjunctive effect for left pulmonary vein isolation of vein of Marshall ethanol infusion in persistent atrial fibrillation

Abstract Objective This study sought to assess the effect of ethanol infusion into the vein of Marshall (EIVOM) on the acute success of left pulmonary vein (LPV) isolation in persistent atrial fibrillation (PeAF). Methods and results A total of 313 patients with drug-resistant PeAF were enrolled (135 in Group 1 and 178 in Group 2). In Group 1, EIVOM was firstly performed, followed by radiofrequency ablation (RFA) including bilateral pulmonary vein isolation (PVI) and linear ablation at roofline, cavotricuspid isthmus, and mitral isthmus (MI). In Group 2, PVI and linear ablations were completed with RFA. First-pass isolation of the LPV was achieved in 119 (88.1%) and 132 (74.2%) patients in Groups 1 and 2, respectively (P = 0.002). The rate of acute pulmonary vein reconnection (PVR) was significantly lower in Group 1 (9.6% vs. 22.5%, P = 0.003). About half of acute PVR occurred in the carina with or without EIVOM. Conclusion EIVOM is effective in achieving a higher first-pass isolation and a lower acute PVR of LPV in PeAF.

Huang, Lihong (ORCID:000000027261316X)↗
DOE OSTI2021

Wide-blocky veins explained by dependency of crystal growth rate on fracture surface type: Insights from phase-field modeling

Vein microstructures contain a wealth of information on coupled chemical and mechanical processes of fracturing, fluid transport, and crystal growth. Numerical simulations have been used for exploring the factors controlling the development of vein microstructures; however, they have not been quantitatively validated against natural veins. Here we combined phase-field modeling with microtextural analysis of previously unexplained wide-blocky calcite veins in natural limestone and of the fresh fracture surface in this limestone. Results show that the wide-blocky vein textures can only be reproduced if ~10%–20% of crystals grow faster than the rest. This fraction corresponds to the amount of transgranularly broken grains that were observed on the experimental fracture surfaces, which are dominantly intergranular. We hypothesize that transgranular fractures allow faster growth of vein minerals due to the lack of clay coatings and other nucleation discontinuities that are common along intergranular cracks. Our simulation results show remarkable similarity to the natural veins and reproduce the nonlinear relationship between vein crystal width and vein aperture. This allows accurate simulations of crystal growth processes and related permeability evolution in fractured rocks.

Geology↗
DOE OSTI2019

Feasibility of Helical I-125 Seed Implant in the Portal Vein

Purpose: To evaluate the feasibility of helical iodine-125 (I-125) seed portal vein implantation. Materials and Methods: Helical I-125 seed implants were placed into the portal vein of healthy pigs through the transjugular (n = 3) or percutaneous transhepatic (n = 3) route. Six pigs received follow-up at 9 weeks after implantation. Blood tests were performed preimplantation, and at 1 and 9 weeks after implantation. Contrast-enhanced computed tomography (CT) and single-photon emission computed tomography combined with CT (SPECT-CT) were acquired after implantation. Post-implantation CT was imported to the treatment planning system (TPS) for dose verification. At 9 weeks after implantation, another CT was performed before histopathological examination. Results: All implantations were successful, and the helical implants were fixed to the portal vein. CT showed no implant migration or portal vein thrombosis. The average dose to 90% of the target volume calculated from TPS was 68.4 Gy. SPECT-CT revealed an irregular isodose around the implant, in which the hottest spot was near the central portal vein lumen. All pigs were in good condition at the 9-week follow-up. Histopathology studies confirmed no portal vein thrombosis. Pigs showed no signs of bleeding, necrosis, or perforation of the peripheral tissue or organs. Intimal hyperplasia was observed at the two ends of the implant. A mild inflammatory response was detected in the bile duct and adjacent liver tissues, yet there was no apparent inflammation of the hepatic arteries. Conclusion: The helical I-125 seed implants can be inserted into the portal veins of healthy pigs.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2020

Boron and Lithium in Calcium Sulfate Veins: Tracking Precipitation of Diagenetic Materials in Vera Rubin Ridge, Gale Crater

The NASA Curiosity rover's ChemCam instrument suite has detected boron in calcium-sulfate-filled fractures throughout the sedimentary strata of Gale crater including Vera Rubin ridge. The presence of elevated B concentration provides insights into Martian subsurface aqueous processes. Here, we extend the data set of B in Ca-sulfate veins across Gale crater, comparing the detection frequency and relative abundances with Li. We report 33 new detections of B within veins analyzed between Sols 1548 and 2311 where detections increase in Pettegrove Point and Jura members, which form Vera Rubin ridge. The presence of B and Li in the Ca-sulfate veins is possibly due to dissolution of preexisting B in clays of the bedrock by acids or neutral water and redistribution of the elements into the veins. Elevated frequency of B detection in veins of Gale crater correlates with presence of dehydration features such as desiccation cracks, altered clay minerals and detections of evaporites such as Mg-sulfates and chloride salts in the host rocks. The increased observations of B also coincide with decreased Li concentration in the veins (average Li concentration of veins drops by ~15 ppm). Boron and Li have varying solubilities, and Li does not form salts as readily upon dehydration as B, causing it to remain in the solution. So the weak negative correlation between B and Li may reflect the crystallization sequence during dehydration on Vera Rubin ridge.

58 GEOSCIENCES↗
DOE OSTI2023

Genetics of varicose veins reveals polygenic architecture and genetic overlap with arterial and venous disease

Varicose veins represent a common cause of cardiovascular morbidity, with limited available medical therapies. Although varicose veins are heritable and epidemiologic studies have identified several candidate varicose vein risk factors, the molecular and genetic basis remains uncertain. Here we analyzed the contribution of common genetic variants to varicose veins using data from the Veterans Affairs Million Veteran Program and four other large biobanks. Among 49,765 individuals with varicose veins and 1,334,301 disease-free controls, we identified 139 risk loci. We identified genetic overlap between varicose veins, other vascular diseases and dozens of anthropometric factors. Using Mendelian randomization, we prioritized therapeutic targets via integration of proteomic and transcriptomic data. Finally, topological enrichment analyses confirmed the biologic roles of endothelial shear flow disruption, inflammation, vascular remodeling and angiogenesis. Further, these findings may facilitate future efforts to develop nonsurgical therapies for varicose veins.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2021

MicroRNA-92a -mediated endothelial to mesenchymal transition controls vein graft neointimal lesion formation

Highlights: • TGF-β triggers microRNA-92a mediated EndMT by targeting ITGA5 is key role in vein graft vascular remodeling. • Silencing of microRNA-92a-mediated endothelial to mesenchymal transition inhibits vein graft neointimal hyperplasia. • Local adeno-associated virus delivery gene therapy deregulation of microRNA-92a-mediated EndMT may represent promising therapeutic approach for vein grafts failure. Long-term failure of vein grafts due to neointimal hyperplasia remains an important problem in coronary artery bypass graft surgery. Endothelial to mesenchymal transition (EndMT) contributes to vein graft vascular remodeling. However, there is little study on microRNA-mediated EndMT contributions to neointimal formation in vein graft. We hypothesized that microRNA-92a (miR-92a) might play an important role in determining EndMT contributions to neointimal formation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2020

Formation of wide-blocky calcite veins by extreme growth competition

Liassic limestones on the coast of Somerset in the UK contain dense arrays of calcite microveins with a common, but poorly understood microstructure, characterized by laterally wide crystals that form bridges across the vein. We investigated the mechanisms of formation and evolution of these ‘wide-blocky’ vein microstructures using a combination of high-resolution analytical methods, including virtual petrography, optical cathodoluminescence and scanning electron microscopy techniques (e.g. energy-dispersive X-ray spectrometry, back-scattered electron imaging, cathodoluminescence and electron back-scattered diffraction), laboratory experiments and multiphase field modelling. Our results indicate that the studied veins formed in open, fluid-filled fractures, each in a single opening and sealing episode. As shown by the optical and electron back-scattered diffraction images, the vein crystals grew epitaxially on grains of the wall rock and we hypothesize that their growth rates differed depending on whether the crystals were on a wall rock grain substrate that fractured intergranularly (slow growth rates) or transgranularly (rapid growth rates). Our multiphase field models support this hypothesis, showing that wide, blocky crystals only form where there are significant differences in the growth rate and are dependent on the type of seed grain. These results provide strong evidence for extreme growth competition, a process that we propose controls vein-filling in many micritic carbonate reservoirs, as well as demonstrate that the characteristics of the fracture wall can affect the filling processes in syntaxial veins. Supplementary material: The description and images of the studied thin sections are available at https://doi.org/10.6084/m9.figshare.c.5172371 . High-resolution optical microscopy mosaics (under plane-polarized- and crossed polarized light) of the thin section collection in PetroScan file format are available on request from the authors.

Geology↗
DOE OSTI2019

Endovascular Treatment of Post-thrombotic Venous Ilio-Femoral Occlusions: Prognostic Value of Venous Lesions Caudal to the Common Femoral Vein

Objectives: To propose a scale of severity for post-thrombotic venous lesions (PTVLs) after ilio-femoral deep venous thrombosis and to compare the grade with the results of endovascular treatment of ilio-femoral PTVLs. Methods: In this retrospective monocentric observational study, we included 95 patients treated for ilio-femoral PTVLs. We proposed a four-grade scale evaluating the severity of PTVLS caudal to the common femoral vein based on CT phlebography and per-operative phlebography. For most patients, venous patency was assessed with color duplex ultrasonography and the clinical efficacy of the intervention using the Villalta and CIVIQ scores. Results: Recanalization was successful in 100% of patients with a morbidity rate of 4%. After a mean follow-up of 21 months, the overall primary patency was 75%, the assisted primary patency 82%, and the secondary patency 93%. Secondary patency was 100% for grade 0–1, 90% for grade 2, and 63% for grade 3 (p < 0.002). There was no correlation between the extension of stenting caudally of the common femoral vein and venous patency. The mean improvements in the Villalta and CIVIQ-20 scores were, respectively, 4.6 (p < 0.0001) and 18 (p < 0.0001); scores were not correlated with the grade of PTVLs in the thigh. Conclusion: Venous patency after endovascular treatment of ilio-femoral PTVLs was strongly linked to the severity of PTVLs caudal to the common femoral vein but not to the extent of stenting.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Intraabdominal Hemorrhage from Ruptured Ectopic Varices Treated by Antegrade Embolization via a Recanalized Paraumbilical Vein

A 49-year-old man with alcoholic liver cirrhosis was admitted to our hospital with abdominal pain. Contrast-enhanced CT demonstrated massive hemorrhagic ascites and ectopic varices fed by right colic and ileocolic veins. The varices were treated with selective embolization via a recanalized paraumbilical vein using N-butyl cyanoacrylate. Currently, no complications and rebleeding have occurred for 7 months. Antegrade embolization via a recanalized paraumbilical vein is feasible and less-invasive in a patient with massive ascites. Flow reduction may be effective for intraabdominal hemorrhage from ruptured ectopic varices. Level of Evidence: Level 5, case report.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Safety and Feasibility of Helical I-125 Seed Implants Combined with Transcatheter Arterial Chemoembolization in Hepatocellular Carcinomas with Main Portal Vein Tumor Thrombus

Purpose: To investigate the feasibility and safety of a helical iodine-125 (I-125) seed implant combined with transcatheter arterial chemoembolization (TACE) for the treatment of hepatocellular carcinoma (HCC) with main portal vein tumor thrombus (MPVTT). Methods: From December 2016 to February 2018, 26 cases of HCC with MPVTT patients were enrolled in this prospective study. Helical I-125 seed implants were placed into the portal vein through the percutaneous transhepatic route. Subsequently, TACE was performed. Follow-up with enhanced CT was performed every 6–8 weeks and TACE was repeated if the residual or recurrent tumor was found. Treatment response was measured with the modified response evaluation criteria in solid tumors. Complication rates and overall survival were also evaluated. Results: Implantation and TACE were successful in all patients. There were no grade ≥ 3 complications observed in the patients. The objective response rates (ORR) and disease control rates (DCR) of MPVTT at 3 months after implantation were 42.3% and 84.6%, respectively, whereas ORR and DCR of the liver lesions were 34.6% and 46.2%, respectively. The median overall survival was 10.7 months (95% CI 6.2–15.2 months). Conclusion: Helical I-125 seed implants can be safely placed into the human main portal vein. Helical I-125 seed implants combined with TACE for HCC with MPVTT are safe and feasible.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2023

Aperture size distribution, length, and preferential location of bed-parallel veins in shale

Bed-parallel, calcite-filled veins (BPVs) are common in shale formations, and although they have been widely described in other studies, little is known about their population aperture size distribution. To address this knowledge gap, we analyzed BPV sizes in outcrops and cores from the Vaca Muerta Formation, Neuquén Basin, Argentina; in two cores from the Marcellus Formation, Appalachian Basin, northeast Pennsylvania; and in one core from the Wolfcamp Shale, Delaware Basin, West Texas. Nine out of ten aperture size populations follow a negative exponential distribution, with one following a weak power law. Bed-parallel vein size distribution and intensity vary among formations and within the same shale. We define three groups of distributions: (1) Vaca Muerta outcrops, with the highest BPV intensity and the largest BPVs (cumulative frequency of 4.9 BPVs per meter [BPVs/m] for apertures 0.265 mm to 8.7 cm); (2) Vaca Muerta cores with a similar BPV intensity overall but with no apertures wider than 1.2 cm; and (3) Vaca Muerta, Wolfcamp, and Marcellus cores with the fewest BPVs (cumulative frequency up to 0.63 BPVs/m) and very few wider than 1 cm. Aperture and length in two outcrop data sets are weakly positively correlated and follow power laws with exponents of 0.44 and 0.49. Mechanical interfaces at boundaries between different lithologies exert a strong control on BPV location, with 65–75% of observed interfaces having BPVs along them. Only 25–30% of the BPVs occur at observed material interfaces, however, and unless subtle, unobserved mechanical layering is present, other factors must also control location. BPV intensity and organic richness (TOC) from Vaca Muerta well logs are correlated in some instances but not in others, indicating TOC is not always a good proxy for BPV location or intensity. Furthermore, these findings provide useful information for modeling of hydraulic fracture treatments where BPVs may influence development of the stimulated fracture network, for example by limiting height growth.

58 GEOSCIENCES↗
DOE OSTI2019

Interventional Treatment Strategy for Primary Budd–Chiari Syndrome with Both Inferior Vena Cava and Hepatic Vein Involvement: Patients from Two Centers in China

Objective: This retrospective study evaluated interventional treatments (recanalization, balloon dilation, and/or stent placement) for Budd–Chiari syndrome (BCS), caused by combined obstruction of the inferior vena cava (IVC) and hepatic veins (HVs). Methods: Before and after interventional therapy, patients with BCS (n = 162; asymptomatic 105.2 ± 103.3 mo; follow-up 15 [6–24] mo) underwent imaging studies (color Doppler ultrasound, CT, or MRI), and inferior vena cavography and manometry. Venous lesions were characterized by occlusion features, and presence of thrombosis and peripheral collateral vessels. Results: One, 2, and 3 main HV occlusions were observed, respectively, in 25 (15.4%), 61 (37.7%), and 76 (46.9%) patients. Eighty-three (51.2%), 98 (60.5%), and 104 (64.2%) patients had, respectively, large accessory HVs, venous collaterals formed between the HVs, or venous communicating branches between the HV and the peritoneal veins. The middle, left, and right HV was patent in 32 (19.8%), 35 (21.6%), and 44 (27.2%) patients. Recanalization of both hepatic and caval occlusions was successful in 96% (51/53) of those attempted; recanalization of IVC occlusion was successful in 97% (106/109). Among 157 patients successfully treated, 146 were cured and 11 showed clinical improvement. Clinical symptoms were relieved in 82.4% after the initial intervention, and 94.2% after the second intervention. Conclusion: Recanalization and balloon angioplasty was effective for the management of BCS with concurrent HV and IVC occlusions. The majority of patients required only IVC recanalization. The outcome of patients treated only by IVC intervention was similar to that of patients given combined HV and IVC intervention.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Value of {sup 18}F-FDG PET/CT in the diagnosis of portal vein tumor thrombus in patients with hepatocellular carcinoma

Objective: The aim of this study was to evaluate the usefulness of {sup 18}F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) for the diagnosis of a portal vein tumor thrombus (PVTT) in patients with hepatocellular carcinoma (HCC). Methods: One hundred fifty-four patients with histologically proven HCC underwent {sup 18}F-FDG PET/CT imaging. The maximum standardized uptake value (SUVmax) was calculated, and the change in SUVmax (retention index, RI) was defined as the ratio of the increase in SUVmax between early and delayed scans to the SUVmax in the early scan. The circular region of interest was placed on the transaxial images according to the corresponding CT images. The final diagnoses of a PVTT were confirmed by histopathology. Results: Of the patients examined, 101 (65.6%) had no confirmed instances of a PVTT, whereas 53 (34.4%) had a confirmed PVTT. The sensitivity of {sup 18}F-FDG PET/CT imaging was 62.3%, the specificity was 97.0%, the accuracy was 85.1%, the positive predictive value was 91.7%, and the negative predictive value was 83.1%. The SUVmax of the PVTT was 4.32 ± 1.96 and the SUVmax of the HCC lesions for these patients was 5.38 ± 2.79, but these differences were insignificant (t = 1.78, p = 0.08). For dual-time-point imaging, the SUV1 of the PVTT lesions was 3.75 ± 1.48, and SUV2 was 3.63 ± 1.41, but these differences were insignificant (t = 0.82, p = 0.42). The SUV1 of the HCC lesions was 4.47 ± 2.03, and the SUV2 was 4.90 ± 2.07, which were both also insignificant (t = − 1.81, p = 0.09). The RI of the PVTT lesions was − 2.05 ± 19.96%, and the RI of the HCC lesions was 11.87 ± 26.20%, with no significant differences between them (t = 1.58, p = 0.13). Conclusions: {sup 18}F-FDG PET/CT may potentially improve the accurate diagnoses of a PVTT in patients with HCC.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Segment 2/3 Hypertrophy is Greater When Right Portal Vein Embolisation is Extended to Segment 4 in Patients with Colorectal Liver Metastases: A Retrospective Cohort Study

Background: In patients with colorectal cancer liver metastases (CRLM), right portal vein embolisation (RPVE) is used to increase the volume of the future remnant liver (FRL) before major hepatic resection. It is not established whether embolisation of segment 4 in addition RPVE (RPVE + 4) induces greater hypertrophy of the FRL. Limitations of prior studies include heterogenous populations and use of hypertrophy metrics sensitive to baseline variables. Methods: From 2010 to 2015, consecutive patients undergoing RPVE or RPVE + 4 for CRLM, who had not undergone prior major hepatic resection and in whom imaging was available, were included in a retrospective study. Data were extracted from hospital electronic records. Volumetric assessments of segments 2–3 were made on cross-sectional imaging before and after embolisation and corrected for standardised liver volume. Results: Ninety-nine patients underwent PVE, and 60 met the inclusion criteria. Thirty-eight patients underwent RPVE, and 22 underwent RPVE + 4. Forty-five patients had undergone median 6 cycles of prior chemotherapy. Eighteen patients had FRL metastases at PVE, and 16 had undergone subsegmental metastasectomy in the FRL. Assessments of the degree of hypertrophy (DH) of segments 2/3 were made at median 35 (interquartile range 30–49) days after PVE. RPVE + 4 resulted in a significantly greater increase in DH than RPVE (7.7 ± 1.8% vs 11.3 ± 2.6%, p = 0.011). No confounding association between baseline variables and the decision to undertake RPVE or RPVE + 4 was identified. Median survival was 2.4 years and was not influenced by segment 4 embolisation. Conclusion: RPVE + 4 results in greater DH of segments 2/3 than RPVE in people with CLRM.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2018

Future Liver Remnant Indocyanine Green Plasma Clearance Rate as a Predictor of Post-hepatectomy Liver Failure After Portal Vein Embolization

PurposeTo evaluate the utility of future liver remnant plasma clearance rate of indocyanine green (ICGK-F) for predicting post-hepatectomy liver failure (PHLF) compared with percentage future liver remnant volume-to-total liver volume ratio (%FLR) after portal vein embolization (PVE).Materials and MethodsPVE procedures in 20 patients (15 patients underwent PVE with absolute ethanol; 5 patients with gelatin particles) from 2010 to 2017 were analyzed. %FLR = future liver remnant volume (ml)/[total liver volume (ml) − tumor volume (ml)] × 100; ICGK-F = plasma clearance rate of indocyanine green (ICGK) × %FLR/100 were calculated before and after PVE. PHLF was categorized according to the criteria of the International Study Group of Liver Surgery. For predicting PHLF, we compared the ICGK-F and %FLR after PVE between the grade A PHLF group and the non-grade A PHLF (grades B and C) group.ResultsAll PVE procedures were successful. While the ICGK-F of the grade A PHLF group (median 0.073, n = 16) was about twice that of the non-grade A PHLF group (median 0.043, n = 4), showing a significant difference (Mann–Whitney U test: P = 0.002), there was no significant difference in %FLR between the grade A PHLF group and the non-grade A PHLF group (Mann–Whitney U test: P = 0.335).ConclusionICGK-F was significantly higher in the grade A PHLF group than in the non-grade A PHLF group (grades B and C), and ICGK-F was more useful for predicting PHLF than %FLR.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Hydrodissection of the Retrohepatic Space: A Technique to Physically Separate a Liver Tumour from the Inferior Vena Cava and the Ostia of the Hepatic Veins

Objective: To report a technique of percutaneous retrohepatic hydrodissection, highlighting its potential to physically separate liver tumours from the inferior vena cava (IVC) and the ostia of the hepatic veins (HV). Materials and Methods: Between December 2017 and April 2018, hydrodissection of the retrohepatic IVC was performed in 5 patients (5 females; mean age 64.5 years) undergoing percutaneous ablation of 5 liver metastases (mean size: 3.6 cm) located adjacent to the IVC. Number of hydrodissection needles, volume of hydrodissection, separation of tumour/liver parenchyma from IVC/HV post-hydrodissection; technical success of ablation; and complications were tabulated. Results: Two to three 22G spinal needles were required per case for adequate dissection. Mean volume to obtain sufficient hydrodissection was 410 ml on average. Physical separation of the IVC and tumour/hepatic parenchyma was successful in all cases, by 9 mm on average (range 5–12 mm). It also leaded to physical separation of the ostia of the right and middle HV in all cases. There was no early or delayed complication, notably no venous thrombosis in the post-operative period. All lesions but one were completely ablated after one session at 3-month follow-up. The patient with residual tumour was successfully retreated. Conclusion: Retrohepatic hydrodissection is a feasible technique to separate a tumour from the IVC and/or ostia of the HV. This could potentially limit the heat-sink effect/reduce the risk of thrombosis. Larger follow-up studies are required to assess efficacy on a long-term basis.

62 RADIOLOGY AND NUCLEAR MEDICINE↗