| 1. |
- Ade, Peter, et al.
(författare)
-
The Simons Observatory : science goals and forecasts
- 2019
-
Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; :2
-
Tidskriftsartikel (refereegranskat)abstract
- The Simons Observatory (SO) is a new cosmic microwave background experiment being built on Cerro Toco in Chile, due to begin observations in the early 2020s. We describe the scientific goals of the experiment, motivate the design, and forecast its performance. SO will measure the temperature and polarization anisotropy of the cosmic microwave background in six frequency bands centered at: 27, 39, 93, 145, 225 and 280 GHz. The initial con figuration of SO will have three small-aperture 0.5-m telescopes and one large-aperture 6-m telescope, with a total of 60,000 cryogenic bolometers. Our key science goals are to characterize the primordial perturbations, measure the number of relativistic species and the mass of neutrinos, test for deviations from a cosmological constant, improve our understanding of galaxy evolution, and constrain the duration of reionization. The small aperture telescopes will target the largest angular scales observable from Chile, mapping approximate to 10% of the sky to a white noise level of 2 mu K-arcmin in combined 93 and 145 GHz bands, to measure the primordial tensor-to-scalar ratio, r, at a target level of sigma(r) = 0.003. The large aperture telescope will map approximate to 40% of the sky at arcminute angular resolution to an expected white noise level of 6 mu K-arcmin in combined 93 and 145 GHz bands, overlapping with the majority of the Large Synoptic Survey Telescope sky region and partially with the Dark Energy Spectroscopic Instrument. With up to an order of magnitude lower polarization noise than maps from the Planck satellite, the high-resolution sky maps will constrain cosmological parameters derived from the damping tail, gravitational lensing of the microwave background, the primordial bispectrum, and the thermal and kinematic Sunyaev-Zel'dovich effects, and will aid in delensing the large-angle polarization signal to measure the tensor-to-scalar ratio. The survey will also provide a legacy catalog of 16,000 galaxy clusters and more than 20,000 extragalactic sources.
|
|
| 2. |
- Fischer, Hubertus, et al.
(författare)
-
Palaeoclimate constraints on the impact of 2 °C anthropogenic warming and beyond
- 2018
-
Ingår i: Nature Geoscience. - : Springer Science and Business Media LLC. - 1752-0894 .- 1752-0908. ; 11:7, s. 474-485
-
Tidskriftsartikel (refereegranskat)abstract
- Over the past 3.5 million years, there have been several intervals when climate conditions were warmer than during the pre-industrial Holocene. Although past intervals of warming were forced differently than future anthropogenic change, such periods can provide insights into potential future climate impacts and ecosystem feedbacks, especially over centennial-to-millennial timescales that are often not covered by climate model simulations. Our observation-based synthesis of the understanding of past intervals with temperatures within the range of projected future warming suggests that there is a low risk of runaway greenhouse gas feedbacks for global warming of no more than 2 °C. However, substantial regional environmental impacts can occur. A global average warming of 1–2 °C with strong polar amplification has, in the past, been accompanied by significant shifts in climate zones and the spatial distribution of land and ocean ecosystems. Sustained warming at this level has also led to substantial reductions of the Greenland and Antarctic ice sheets, with sea-level increases of at least several metres on millennial timescales. Comparison of palaeo observations with climate model results suggests that, due to the lack of certain feedback processes, model-based climate projections may underestimate long-term warming in response to future radiative forcing by as much as a factor of two, and thus may also underestimate centennial-to-millennial-scale sea-level rise.
|
|
| 3. |
- Pisu, Francesco, et al.
(författare)
-
Machine learning detects symptomatic patients with carotid plaques based on 6-type calcium configuration classification on CT angiography
- 2024
-
Ingår i: European Radiology. - : Springer. - 0938-7994 .- 1432-1084. ; 34:6, s. 3612-3623
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: While the link between carotid plaque composition and cerebrovascular vascular (CVE) events is recognized, the role of calcium configuration remains unclear. This study aimed to develop and validate a CT angiography (CTA)–based machine learning (ML) model that uses carotid plaques 6-type calcium grading, and clinical parameters to identify CVE patients with bilateral plaques.Material and methods: We conducted a multicenter, retrospective diagnostic study (March 2013–May 2020) approved by the institutional review board. We included adults (18 +) with bilateral carotid artery plaques, symptomatic patients having recently experienced a carotid territory ischemic event, and asymptomatic patients either after 3 months from symptom onset or with no such event. Four ML models (clinical factors, calcium configurations, and both with and without plaque grading [ML-All-G and ML-All-NG]) and logistic regression on all variables identified symptomatic patients. Internal validation assessed discrimination and calibration. External validation was also performed, and identified important variables and causes of misclassifications.Results: We included 790 patients (median age 72, IQR [61–80], 42% male, 64% symptomatic) for training and internal validation, and 159 patients (age 68 [63–76], 36% male, 39% symptomatic) for external testing. The ML-All-G model achieved an area-under-ROC curve of 0.71 (95% CI 0.58–0.78; p <.001) and sensitivity 80% (79–81). Performance was comparable on external testing. Calcified plaque, especially the positive rim sign on the right artery in older and hyperlipidemic patients, had a major impact on identifying symptomatic patients.Conclusion: The developed model can identify symptomatic patients using plaques calcium configuration data and clinical information with reasonable diagnostic accuracy.Clinical relevance: The analysis of the type of calcium configuration in carotid plaques into 6 classes, combined with clinical variables, allows for an effective identification of symptomatic patients.Key Points: • While the association between carotid plaques composition and cerebrovascular events is recognized, the role of calcium configuration remains unclear. • Machine learning of 6-type plaque grading can identify symptomatic patients. Calcified plaques on the right artery, advanced age, and hyperlipidemia were the most important predictors. • Fast acquisition of CTA enables rapid grading of plaques upon the patient’s arrival at the hospital, which streamlines the diagnosis of symptoms using ML. Graphical Abstract: [Figure not available: see fulltext.].
|
|
| 4. |
- Sugai, H., et al.
(författare)
-
Updated Design of the CMB Polarization Experiment Satellite LiteBIRD
- 2020
-
Ingår i: Journal of Low Temperature Physics. - : Springer Science and Business Media LLC. - 0022-2291 .- 1573-7357. ; 199:3-4, s. 1107-1117
-
Tidskriftsartikel (refereegranskat)abstract
- Recent developments of transition-edge sensors (TESs), based on extensive experience in ground-based experiments, have been making the sensor techniques mature enough for their application on future satellite cosmic microwave background (CMB) polarization experiments. LiteBIRD is in the most advanced phase among such future satellites, targeting its launch in Japanese Fiscal Year 2027 (2027FY) with JAXA's H3 rocket. It will accommodate more than 4000 TESs in focal planes of reflective low-frequency and refractive medium-and-high-frequency telescopes in order to detect a signature imprinted on the CMB by the primordial gravitational waves predicted in cosmic inflation. The total wide frequency coverage between 34 and 448 GHz enables us to extract such weak spiral polarization patterns through the precise subtraction of our Galaxy's foreground emission by using spectral differences among CMB and foreground signals. Telescopes are cooled down to 5 K for suppressing thermal noise and contain polarization modulators with transmissive half-wave plates at individual apertures for separating sky polarization signals from artificial polarization and for mitigating from instrumental 1/f noise. Passive cooling by using V-grooves supports active cooling with mechanical coolers as well as adiabatic demagnetization refrigerators. Sky observations from the second Sun-Earth Lagrangian point, L2, are planned for 3 years. An international collaboration between Japan, the USA, Canada, and Europe is sharing various roles. In May 2019, the Institute of Space and Astronautical Science, JAXA, selected LiteBIRD as the strategic large mission No. 2.
|
|
| 5. |
- Torsello, Giovanni Federico, et al.
(författare)
-
One-Year Results From the SURPASS Observational Registry of the CTAG Stent-Graft With the Active Control System
- 2020
-
Ingår i: Journal of Endovascular Therapy. - : Sage Publications. - 1526-6028 .- 1545-1550. ; 27:3, s. 421-427
-
Tidskriftsartikel (refereegranskat)abstract
- Purpose: To report the outcomes from the observational SURPASS registry, which was created to assess the performance of the Conformable TAG (CTAG) stent-graft with the Active Control System (ACS) in patients undergoing thoracic endovascular aortic repair (TEVAR) in a real-world setting.Materials and Methods: The SURPASS registry (ClinicalTrials.gov; identifier NCT03286400) was an observational, prospective, single-arm, post-market, international study that enrolled patients undergoing TEVAR using the CTAG with ACS for both acute and chronic thoracic aortic disease between October 2017 and July 2018. The CTAG with ACS features 2-stage deployment of the stent-graft and an optional angulation mechanism that modifies only the proximal end of the stent-graft. During the observation period, 127 patients (mean age 67.1±12.1 years, range 27-86; 92 men) were enrolled and treated for an array of aortic pathologies, including chronic and acute lesions and 4 ruptured descending thoracic aneurysms. The primary outcome of this study was technical success; secondary outcomes were clinical success and major adverse events at 30 days and 12 months. The numbers of 2-stage device deployments and applications of the angulation mechanism were recorded, along with the reasons for use.Results: Technical success of the TEVAR was 97.6% owing to unintentional partial coverage of supra-aortic branches in 3 cases (the vessels were patent on imaging). The stent-graft was repositioned at its intermediate diameter in 79 patients (62.2%), and the angulation feature was applied in 64 cases (50.4%), mainly to improve proximal wall apposition and orthogonality in the aorta. The desired effect was achieved in 60 cases (93.8%). There was no device compression, bird-beak configuration, fracture, or graft occlusion. The 30-day and 12-month clinical success rates were 97.6% and 92.9%, respectively. There were 3 aorta-related deaths at 30 days and a further 3 at 12 months. Fatalities were due to a retrograde type A dissection (0.8%), paraplegia, bowel ischemia, sepsis in the setting of a mycotic aneurysm, aneurysm rupture post aortoesophageal fistula, and multiorgan dysfunction syndrome. Three endoleaks (2 type Ia and 1 type III) required reintervention.Conclusion: In the SURPASS registry, the use of the CTAG device with ACS showed promising outcomes despite the challenging pathologies. The new delivery system enables a controlled staged delivery with in situ adjustments during positioning, facilitating the treatment of complex aortic disease.
|
|
| 6. |
- Tsilimparis, Nikolaos, et al.
(författare)
-
Transatlantic multicenter study on the use of a modified preloaded delivery system for fenestrated endovascular aortic repair
- 2023
-
Ingår i: Journal of Vascular Surgery. - 0741-5214. ; 78:4, s. 3-873
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: Analyze the outcomes of endovascular complex abdominal and thoracoabdominal aortic aneurysm repair using the Cook fenestrated device with the modified preloaded delivery system (MPDS) with a biport handle and preloaded catheters. Methods: A multicenter retrospective single arm cohort study was performed, including all consecutive patients with complex abdominal aortic aneurysm repair and thoracoabdominal aortic aneurysms treated with the MPDS fenestrated device (Cook Medical). Patient clinical characteristics, anatomy, and indications for device use were collected. Outcomes, classified according to the Society for Vascular Surgery reporting standards, were collected at discharge, 30 days, 6 months, and annually thereafter. Results: Overall, 712 patients (median age, 73 years; interquartile range [IQR], 68-78 years; 83% male) from 16 centers in Europe and the United States treated electively were included: 35.4% (n = 252) presented with thoracoabdominal aortic aneurysms and 64.6% (n = 460) with complex abdominal aortic aneurysm repair. Overall, 2755 target vessels were included (mean, 3.9 per patient). Of these, 1628 were incorporated via ipsilateral preloads using the MPDS (1440 accessed from the biport handle and 188 from above). The mean size of the contralateral femoral sheath during target vessel catheterization was 15F ± 4, and in 41 patients (6.7%) the sheath size was ≤8F. Technical success was 96.1%. Median procedural time was 209 minutes (IQR, 161-270 minutes), contrast volume was 100 mL (IQR, 70-150mL), fluoroscopy time was 63.9 minutes (IQR, 49.7-80.4 minutes) and median cumulative air kerma radiation dose was 2630 mGy (IQR, 838-5251 mGy). Thirty-day mortality was 4.8% (n = 34). Access complications occurred in 6.8% (n = 48) and 30-day reintervention in 7% (n = 50; 18 branch related). Follow-up of >30 days was available for 628 patients (88%), with a median follow-up of 19 months (IQR, 8-39 months). Branch-related endoleaks (type Ic/IIIc) were observed in 15 patients (2.6%) and aneurysm growth of >5 mm was observed in 54 (9.5%). Freedom from reintervention at 12 and 24 months was 87.1% (standard error [SE],1.5%) and 79.2% (SE, 2.0%), respectively. Overall target vessel patency at 12 and 24 months was 98.6% (SE, 0.3%) and 96.8% (SE, 0.4%), respectively, and was 97.9% (SE, 0.4%) and 95.3% (SE, 0.8%) for arteries stented from below using the MPDS, respectively. Conclusions: The MPDS is safe and effective. Overall benefits include a decrease in contralateral sheath size in the treatment of complex anatomies with favorable results.
|
|
| 7. |
- Usai, Marco, V, et al.
(författare)
-
Systematic review of atherectomy of inguinal arteries for atherosclerotic lesions
- 2022
-
Ingår i: Journal of Cardiovascular Surgery. - : Edizioni Minerva Medica. - 0021-9509 .- 1827-191X. ; 63:1, s. 2-7
-
Forskningsöversikt (refereegranskat)abstract
- INTRODUCTION: Surgical endarterectomy represents the gold standard for the treatment of atherosclerotic lesions of the groin vessels. Endovascular treatment such as atherectomy with or without drug coated angioplasty (DCA) of the so called no stenting zones, i.e. inguinal and popliteal vessels, is gaining growing acceptance as alternative option to open surgery. This systematic review aims to scrutiny the current clinical evidence regarding atherectomy and DCA for the common artery (CFA).EVIDENCE ACQUISITION: We conducted an exhaustive research in multiple platforms (Medline, PubMed, Cochrane, Google Scholar, Em base) on studies over atherectomy and angioplasty for inguinal atherosclerotic lesions published between 2000 and 2021. As search strategy we used a wide list of MeSH items, words, synonyms. Bibliographies of review articles were checked for further relating studies regarding atherectomy of CFA. A qualitative and quantitative data analysis was carried out.EVIDENCE SYNTHESIS: Fifteen studies were included in the qualitative review. Not all studies were focused only on atherectomy of inguinal vessels, despite including such treatment. Hence, data regarding this treatment were not exhaustive. A fairly homogeneous data analysis was possible in 7 of 15 studies. The remaining 8 studies were qualitatively analyzed but not included in the statistical analysis. In all 7 included studies directional atherectomy and DCA under filter protection were carried out. In this subgroup, overall, 497 patients were treated with atherectomy. Sixty-eight percent of the patients were males. Rutherford class from 1-3 dominated against 4-6 (63% vs. 37%). Mean technical success rate was 96%, with a primary and secondary patency rate of 92% and 98% respectively at one year. Procedure related vascular complications ranged from 1% to 6%.CONCLUSIONS: Current literature about atherectomy for inguinal arteries is scant, data are inhomogeneous and so are treatment modalities. Nevertheless, the results of this systematic review suggest that this endovascular strategy is feasible with good short and midterm results. Prospective trials with larger patient cohorts are necessary to confirm these preliminary results.
|
|
| 8. |
- Vacirca, Andrea, et al.
(författare)
-
The optimal operative protocol to accomplish CO2-EVAR resulting from a prospective interventional multicenter study
- 2023
-
Ingår i: Journal of Vascular Surgery. - : Elsevier BV. - 0741-5214. ; 77:5, s. 1-1412
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: Carbon dioxide (CO2) angiography for endovascular aortic repair (CO2-EVAR) is used to treat abdominal aortic aneurysms (AAAs), especially in patients with chronic kidney disease or allergy to iodinated contrast medium (ICM). However, some technical issues regarding the visualization of the lowest renal artery (LoRA) and the best quality image through angiographies performed from pigtail or introducer sheath are still unsolved. The aim of this study was to analyze different steps of CO2-EVAR to create an operative standardized protocol. Methods: Patients undergoing CO2-EVAR were prospectively enrolled in five European centers from 2019 to 2021. CO2-EVAR was performed using an automated injector (pressure, 600 mmHg; volume, 100 cc); a small amount of ICM was injected in case of difficulty in LoRA visualization. LoRA visualization and image quality (1 = low, 2 = sufficient, 3 = good, 4 = excellent) were analyzed at different procedure steps: preoperative CO2 angiography from pigtail and femoral introducer sheath (first step), angiographies from pigtail at 0%, 50%, and 100% of proximal main body deployment (second step), contralateral hypogastric artery (CHA) visualization with CO2 injection from femoral introducer sheath (third step), and completion angiogram from pigtail and femoral introducer sheath (fourth step). Intraoperative and postoperative CO2-related adverse events were also evaluated. χ2 and Wilcoxon tests were used for statistical analysis. Results: In the considered period, 65 patients undergoing CO2-EVAR were enrolled (55/65 [84.5%] male; median age, 75 years [interquartile range (IQR), 11.5 years]). The median ICM injected was 17 cc (IQR, 51 cc); 19 (29.2%) of 65 procedures were performed with 0 cc ICM. Fifty-five (84.2%) of 65 patients underwent general anesthesia. In the first step, median image quality was significantly higher with CO2 injected from femoral introducer (pigtail, 2 [IQR, 3] vs introducer, 3 [IQR, 3]; P = .008). In the second step, LoRA was more frequently detected at 50% (93% vs 73.2%; P = .002) and 100% (94.1% vs 78.4%; P = .01) of proximal main body deployment compared with first angiography from pigtail; similarly, image quality was significantly higher at 50% (3 [IQR, 3] vs 2 [IQR, 3]; P ≤ .001) and 100% (4 [IQR, 3] vs 2 [IQR, 3]; P = .001) of proximal main body deployment. CHA was detected in 93% cases (third step). The mean image quality was significantly higher when final angiogram (fourth step) was performed from introducer (pigtail, 2.6 ± 1.1 vs introducer, 3.1 ± 0.9; P ≤ .001). The intraoperative (7.7%) and postoperative (12.5%) adverse events (pain, vomiting, diarrhea) were all transient and clinically mild. Conclusions: Preimplant CO2 angiography should be performed from femoral introducer sheath. Gas flow impediment created by proximal main body deployment can improve image quality and LoRA visualization with CO2. CHA can be satisfactorily visualized with CO2 alone. Completion CO2 angiogram should be performed from femoral introducer sheath. This operative protocol allows performance of CO2-EVAR with 0 cc or minimal ICM, with a low rate of mild temporary complications.
|
|
