Shedding Light On An Undiscovered Aspect That Perfectly Mimics Cosmic Acceleration

The comparison of redshift-distance relationship for high and low-redshift supernovae revealed the surprising transition of the Universe’s expansion from deceleration to acceleration. As compared to local supernovae, remote supernovae appear 10% to 25% dimmer as they are further away than expected. The expansion rate obtained for local supernovae is higher with low redshifts as compared to the expansion rate obtained for remote supernovae with high redshifts. Since observed redshifts in an expanding Universe provide an estimate of recession velocities, therefore, it is very disturbing to find that low recession velocities (just 1% of speed of light) indicate a faster rate of expansion (acceleration), whereas high recession velocities (60% of speed of light) indicate a slower rate of expansion (deceleration). In this paper, I unravel an undiscovered aspect that perfectly mimics cosmic acceleration. Rather than “cosmic deceleration that preceded the current epoch of cosmic acceleration”, I show in this paper, that “consecutive expansion epochs of the Universe that preceded the current epoch of cosmic expansion” were responsible for placing remote supernovae further away than expected. As a consequence of consecutive expansion, expansion began for remote structures in preceding expansion epochs before it did for local structures in the current (or more recent) expansion epoch; remote supernovae, quasars, and gamma-ray bursts are therefore not only further away than expected, but they also happen to yield a slower rate of expansion, thereby suggesting their deceleration even with “superluminal expansion”. As a result of consecutive expansion, preceding expansion epochs appear to be decelerating as compared to the expansion epoch that succeeds them. The analysis is based on the redshift-distance relationship plotted for 580 type Ia supernovae from the Supernova Cosmology Project, 7 additional high-redshift type Ia supernovae discovered through the Advanced Camera for Surveys on the Hubble Space Telescope from the Great Observatories Origins Deep Survey Treasury program, and 1 additional very high-redshift type Ia supernova discovered with Wide Field and Planetary Camera 2 on the Hubble Space Telescope. The results obtained by the High-Z Supernova Search Team through observations of type Ia supernovae have also been analysed. Studies incorporating quasars and gamma-ray bursts to determine how the expansion of the Universe has changed over time have been taken into consideration as well. The results obtained in this paper have been confirmed by plotting velocity-distance relationship, expansion rate vs. time relationship, expansion factor vs. time relationship, scale factor vs. time relationship, scale factor vs. distance relationship, distance-redshift relationship, and distance modulus vs. redshift relationship, moreover, the deceleration parameter (q0) is also found to be negative (q0 < 0).

SN 2015bq: A Luminous Type Ia Supernova with Early Flux Excess

We present optical and ultraviolet (UV) observations of a luminous type Ia supernova (SN Ia) SN 2015bq characterized by early flux excess. This SN reaches a B-band absolute magnitude at M B = −19.68 ± 0.41 mag and a peak bolometric luminosity at L = (1.75 ± 0.37) × 1043 erg s−1, with a relatively small post-maximum decline rate [Δm 15(B) = 0.82 ± 0.05 mag]. The flux excess observed in the light curves of SN 2015bq a few days after the explosion, especially seen in the UV bands, might be due to the radioactive decay of 56Ni mixed into the surface. The radiation from the decay of the surface 56Ni heats the outer layer of this SN. It produces blue U − B color followed by monotonically reddening in the early phase, dominated iron-group lines, and weak intermediate-mass element absorption features in the early spectra. The scenario of enhanced 56Ni in the surface is consistent with a large amount of 56Ni ( M 56 Ni = 0.97 ± 0.20 M ☉) synthesized during the explosion. The properties of SN 2015bq are found to locate between SN 1991T and SN 1999aa, suggesting the latter two subclasses of SNe Ia may have a common origin.

Spatially resolved properties of supernova host galaxies in SDSS-IV MaNGA

We crossmatch galaxies from Mapping Nearby Galaxies at Apache Point Observatory with the Open Supernova Catalog, obtaining a total of 132 SNe within MaNGA bundle. These 132 SNe can be classified into 67 Type Ia and 65 Type CC. We study the global and local properties of supernova host galaxies statistically. Type Ia SNe are distributed in both star-forming galaxies and quiescent galaxies, while Type CC SNe are all distributed along the star-forming main sequence. As the stellar mass increases, the Type Ia/CC number ratio increases. We find: (1) there is no obvious difference in the interaction possibilities and environments between Type Ia SN hosts and a control sample of galaxies with similar stellar mass and SFR distributions, except that Type Ia SNe tend to appear in galaxies which are more bulge-dominated than their controls. For Type CC SNe, there is no difference between their hosts and the control galaxies in galaxy morphology, interaction possibilities as well as environments; (2) compared to galaxy centers, the SN locations have smaller velocity dispersion, lower metallicity, and younger stellar population. This is a natural result of radius gradients for all these parameters. The SN location and its symmetrical position relative to the galaxy center, as well as regions with similar effective radii have very similar [Mg/Fe], gas-phase metallicity, gas velocity dispersion and stellar population age.

Endoleak outcomes with different stent-graft generations in a 25-years thoracic endovascular aortic repair experience

Introduction To compare endoleak outcomes after thoracic endovascular aneurysm repair (TEVAR) with different stent-graft generations into long-term follow-up. Design retrospective, observational, and single-center cohort study. Methods TEVAR procedures performed between November 1995 and December 2020 were analyzed. The primary endpoint of this study was the freedom from endoleak (type I/III) in four stent-graft generations during the follow-up period. The first generation (GEN1) included: Vanguard; AneuRx and Talent; Stentor; Excluder; Endologix; EndoFit. The second generation (GEN2) included: TAG and TX. The third (GEN3) included: Relay Plus; Valiant Captivia; Zenith Alpha and custom-made. The fourth (GEN4) included: Relay Pro; Conformable C-TAG; Navion; E-Vita; Najuta; Nexus; standard and custom-made thoraco-abdominal devices. Nonaortic and aorta-related survival was considered as secondary outcome. Results A total of 509 TEVAR were included with a 44.3 ± 42.5 months mean follow-up. Freedom from endoleak at 5 years was 65.6%, 61.4%, 76.2%, and 69.1% for GEN1, GEN2, GEN3, and GEN4, respectively ( p = 0.368). The first two generations demonstrated a higher endoleak rate when compared with the two most recent ones (27.2 vs 18.2%, respectively; p = 0.043). GEN1 was an independent risk factor ( p = 0.014) and GEN4 was an independent protective factor ( p = 0.001) for endoleak. GEN1 was found to be a risk factor for type-Ia endoleak ( p = 0.059). GEN4 demonstrated a protective association regarding type-Ib endoleak ( p = 0.012). Overall survival was 75.3%, 44.4%, 27.2%, and 17.6% at 1, 5, 10, and 15 years, respectively. Survival distinguished as non-related versus aortic-related was 86.7% vs 23.5%, 52.7% vs 9.8%, 32.9% vs 2.0%, 21.2% vs 0% at 1, 5, 10, and 15 years, respectively ( p< 0.000). Conclusion Endoleak occurred in a non-negligible percentage of TEVAR patients. A significant reduction of endoleak incidence over evolving stent-grafts generations was registered. Newer stent-graft generations demonstrated better long-term endoleak. Data about long-term outcomes require ongoing updates to prove both the reliability and the durability of newer stent-graft generations.

Midterm outcomes of 455 patients receiving the AFX2 endovascular graft for the treatment of abdominal aortic aneurysm: A retrospective multi-center analysis

Since being introduced into clinical practice the AFX family of endografts has undergone labelling updates, design and manufacturing changes to address a Type III failure mode. The published literature on the performance of the current endograft–AFX2 –is limited to small series with limited follow up. The present study reports the largest series of patients implanted with AFX2 for the treatment of abdominal aortic aneurysms. The study was a retrospective, 5 center study of patients receiving an AFX2 endograft from January 2016 until Dec 2020. Electronic case report forms were provided to four of the centers, with one additional site providing relevant outcomes in an independent dataset. Relevant outcomes were reported via Kaplan-Meier analysis and included all-cause mortality, aneurysm-related mortality, post EVAR aortic rupture, open conversion, device related reinterventions and endoleaks. Among a cohort of 460 patients, 405 underwent elective repair of an AAA, 50 were treated for a ruptured AAA, and 5 were aorto-iliac occlusive disease cases. For the elective cohort (mean age 73.7y, 77% male, mean AAA diameter 5.4cm), the peri-operative mortality was 1.7%. Freedom from aneurysm-related mortality was 98.2% at 1,2,3 and 4 years post-operatively, there were no post-operative aortic ruptures, and 2 patients required open conversion. Freedom from Type Ia endoleaks was 99.4% at 1, 2, 3 and 4 years. Freedom from Type IIIa and Type IIIb endoleaks were 100% and 100% (year 1), 100% and 99.6% (year 2), 99.4% and 99.6% (year 3), 99.4% and 99.6% (year 4) respectively. Freedom from all device-related reintervention (including Type II endoleaks) at 4 y was 86.8%. The AFX2 endograft appears to perform to a satisfactory standard in terms of patient centric outcomes in mid-term follow up. The Type Ia and Type III endoleaks rates at 4y appear to be within acceptable limits. Further follow up studies are warranted.

Zenith AAA endovascular graft suprarenal bare metal stent separation with graft migration and type IA endoleak

Background The Zenith endovascular graft (Cook Medical, Bloomington, IN, USA) is a well-recognised device used in endovascular repair of abdominal aortic aneurysms (EVAR). After a small number of reported cases of suprarenal stent separation from the main body of the graft, modifications were made to the strength and durability of the suture line attachment of the proximal bare metal component prior to release in 2003. This report describes a further case of suprarenal stent separation and type IA endoleak in a patient who underwent an EVAR using the Zenith device in 2012. Methods We present a case report of a 77-year-old male with incidental finding of type IA endoleak on a background of elective endovascular repair for 50.4-mm infrarenal abdominal aortic aneurysm (AAA), with a Cook Zenith endograft. Computed tomography (CT) demonstrated separation of the suprarenal bare metal stent from the main body of the endograft, with resultant graft migration and increase in native aneurysm sac size. Results The patient underwent semi-urgent surgery with successful placement of a bridging thoracic stent graft between the lowest renal artery and main body of the pre-existing graft. Conclusions This case report describes a rare complication of Zenith devices, additionally emphasising the importance of regular surveillance imaging following EVAR.

Exosomal MicroRNAs as Potential Biomarkers of Hepatic Injury and Kidney Disease in Glycogen Storage Disease Type Ia Patients

Glycogen storage disease type Ia (GSDIa) is an inherited metabolic disorder caused by mutations in the enzyme glucose-6-phosphatase-α (G6Pase-α). Affected individuals develop renal and liver complications, including the development of hepatocellular adenoma/carcinoma and kidney failure. The purpose of this study was to identify potential biomarkers of the evolution of the disease in GSDIa patients. To this end, we analyzed the expression of exosomal microRNAs (Exo-miRs) in the plasma exosomes of 45 patients aged 6 to 63 years. Plasma from age-matched normal individuals were used as controls. We found that the altered expression of several Exo-miRs correlates with the pathologic state of the patients and might help to monitor the progression of the disease and the development of late GSDIa-associated complications.

Thoracic Spinal Angiolipomas: A Systematic Review

Background Spinal angiolipomas (SAs) are rare, benign tumors, representing 0.0004 to 1.2% of angiolipomas, usually located at the extradural and posterior thoracic level, with multimetameric extension. Methods A systematic literature review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The authors searched on PubMed and Scopus databases for published articles with the Mesh term “spinal angiolipoma” and pertinent associations. Language restriction to English papers was applied. The authors also reported three emblematic cases of patients who underwent surgical resection of spindle-shaped (type IA) and dumbbell-shaped (type II) SAs between 2014 and 2020. Results Of the 256 retrieved articles, 33 were included in the meta-analysis. These 33 studies, together with our 3 reported cases, included a total of 60 patients, 36 females (60%) and 24 males (40%), with a mean age of 53.12 ± 12.82 years (range: 12–77 years).T5 was the most represented level (22 patients). Usually, the localization of SA was extradural, with 53 patients suffering from spindle-shaped type IA SA (88.3%) and 7 patients from dumbbell-shaped type II SA (11.6%). Almost all patients underwent laminectomy (78.3%) and presented a full recovery of motor deficits (85%). Gross total removal (GTR) was performed in 93.3% of patients. The mean follow-up was of 22.71 ± 21.45 months (range: 2–80 months). There was no documented recurrence at follow-up magnetic resonance imaging in any of the patients. Conclusions SAs are rare, benign tumors with a great vascular component that presents a favorable outcome. GTR is the gold standard treatment and usually an adjuvant therapy is not required. Even infiltrative lesions, which are more complex, can be treated successfully with a good prognosis. Dumbbell-shaped SAs must be differentiated from schwannomas and meningiomas, and require different surgical techniques, given the profuse bleeding associated with the attempt of debulking. En block resection is the key to treat these common benign tumors with acceptable blood loss.

Treatment of a type Ia endoleak following EVAR using a custom-made inner branch device.

Objectives We represent two cases of late proximal type I endoleak following EVAR with aneurysm expansion that were treated with a custom-made graft with inner branches. Methods Two patients of 87 and 82 years old were operated by EVAR 6 and 8 years ago for abdominal aortic aneurysm. Both had proximal type I endoleak with aneurysm sac expansion. Open surgery had a high risk, and a proximal aortic extension with a simple aortic cuff was not possible neither because previous EVAR grafts were already at the level of the renal arteries. A custom-made endograft with inner branches was planned as a fenestrated graft was not technically possible. Results We successfully treated both patients using a custom-made graft with four inner branches from Jotec (Cryolife, Kennesaw, GA). Three months’ follow-up CT scan did not show any endoleaks. All target vessels were patent with good conformability of the bridging stents. Conclusion The treatment of proximal type I endoleak using inner branches’ endografts is feasible. This novel technology might broaden the indications for complex aortic repair in a group of patients where fenestrated endografts are not possible.