ALMA observations of the outflow from the Source I in the Orion-KL region

In this {\it Letter}, we present sensitive millimeter SiO (J=5-4; $\nu$=0) line observations of the outflow arising from the enigmatic object Orion Source I made with the Atacama Large Millimeter/Submillimeter Array (ALMA). The observations reveal that at scales of a few thousand AU, the outflow has a marked "butterfly" morphology along a northeast-southwest axis. However, contrary to what is found in the SiO and H$_2$O maser observations at scales of tens of AU, the blueshifted radial velocities of the moving gas are found to the northwest, while the redshifted velocities are in the southeast. The ALMA observations are complemented with SiO (J=8-7; $\nu$=0) maps (with a similar spatial resolution) obtained with the Submillimeter Array (SMA). These observations also show a similar morphology and velocity structure in this outflow. We discuss some possibilities to explain these differences at small and large scales across the flow.Comment: Accepted to ApJ

Commentary: The History of Neurosurgery at Albany Medical College and Albany Medical Center Hospital, Albany, New York.

The origins of the Department of Neurosurgery at Albany Medical College closely parallel the development of early America and the establishment of modern health care.The tales of Washington Irving, the works of the Hudson River School of painters, and summers in the Catskill Mountains or Adirondacks are the stories that color the history of Upstate New York (Figure1). As a social, industrial, and political hub of the American colonies, New England’s need for centers providing structured medicine led to the creation of Albany Medical College in1839, one of the earliest such institutions in the young nation.1 Rapid progress in nearly every other realm of life required medical advancements as well, prompting subspecialization and the development of neurosurgery in the region

Rescue stenting for failed mechanical thrombectomy procedures

Background: Mechanical thrombectomy (MT) has dramatically changed the natural history of acute ischemic stroke. The disease that was associated with high morbidity, mortality, and significant cost on the health care system became a treatable disease. One of the most important variables to improve outcomes is time to revascularize the ischemic tissue. Rescue stenting (RS) is an option for patients who fail MT. Methods: A retrospective chart review for patients who underwent a MT procedure and either failed (defined as TICI 0-2a) or required a RS from 2015 – 2019 composed the study population. IRB approval was obtained and the consent was waived due to the study design. Medical charts and imaging were reviewed for baseline characteristics, stroke characteristics, complications, and functional outcome. Comparison was performed between the rescue group and the failed group to analyze outcomes. Results: From 2015-2019, 96 patients failed a MT procedure, and 26 patients required an intracranial stent. Initial NIHSS scores were comparable between the groups, (16.1 ± 7.2 vs. 15.2 ± 8.0, p = 0.552). Patients received comparable pre-procedure care as indicated by similar rate of tPA administration (38.5% vs. 34.6%, p = 0.804) and symptom onset to procedure time (1043.5 ± 3556 vs. 1505.3 ± 5183, p = 0.652). While receiving an intracranial stent led to a longer procedure time (66.1 ± 43.4 vs. 86.6 ± 36.2, p = 0.040), patients receiving a stent had a reduced mortality (32 (36.0%) vs. 3 (12.0%), p = 0.027) and NIHSS at discharge (23.0 ± 14.7 vs. 14.5 ± 13.6, p = 0.034). In the RS group, 4 patients had symptomatic intracranial hemorrhage as opposed to 2 in the non-RS group (3.6% vs 15.4%, p = 0.08). Conclusion: Rescue stenting was associated with good outcomes as indicated by decreased mortality and NIHSS at discharge

Comparative Observational Study for Bifurcating aneurysm treatment; open versus endovascular approaches and classical versus new techniques.

Introduction: Aneurysm occur in approximately 3.2% of the population with a mean age of 50 years, a 1:1 gender ratio, and an estimate mortality rate of 70%. Aneurysms develop at branch points with elevated intravascular turbulence and vessel wall shear stress. we aim to compare the efficacy and safety of different surgical treatment modalities for bifurcating intracranial aneurysms. Methods: A retrospective review of 398 patients who underwent surgical management of a bifurcating aneurysm at Thomas Jefferson University hospital from 2010 to 2020. Aneurysm size, location, modality of treatment, and treatment complications were assessed. Results: Data analysis is expected to return from the statistician in early to mid-December. Data analysis has not been returned to date. Discussion: We hypothesize that those treated with endovascular techniques have better outcomes than those who received intracranial clippings. Additionally, we expect that coil embolization will have better results for saccular aneurysms, while balloon assisted stenting or stent assisted coiling of aneurysm will provide better outcomes for fusiform aneurysms. If these hypotheses hold true, then our data will suggest that there are specific surgical treatment modalities that improve patient outcomes based upon aneurysm type

Abell 1451 and 1RXS J131423.6-251521: a multi-wavelength study of two dynamically perturbed clusters of galaxies

We present results from optical, X-ray and radio observations of two X-ray bright (L_X ~ 10^{45} erg/s) galaxy clusters. A1451 is at redshift z=0.1989 and has line-of-sight velocity dispersion sigma_v = 1330 km/s as measured from 57 cluster galaxies. It has regular X-ray emission without signs of substructure, a Gaussian velocity distribution, lack of a cooling flow region and significant deviations from the observed scaling laws between luminosity, temperature and velocity dispersion, indicating a possible merging shock. There is only one spectroscopically confirmed cluster radio galaxy, which is close to the X-ray peak. 1RXS J131423.6-251521 has z=0.2474 and sigma_v = 1100 km/s from 37 galaxies. There are two distinct galaxy groups with a projected separation of \~700 kpc. The velocity histogram is bi-modal with a redshift-space separation of ~1700 km/s, and the X-ray emission is double peaked. Although there are no spectroscopically confirmed cluster radio galaxies, we have identified a plausible relic source candidate.Comment: 16 pages, 12 figures, some in colour; A&A accepte

Stroke Centers of Excellence in the United States: Certification, Access and Outcomes

Introduction: Stroke is a leading cause of morbidity, mortality and healthcare costs in the United States. Evidence suggests that certified stroke centers have improved patient outcomes relative to non-certified hospitals. Our study explains the process, associated cost, quality and geographic proclivities of different certifying organizations. Methods: Data was collected from published literature, information on certifying organizations’ websites and through direct communication with representatives of The Joint Commission (TJC), Det Norske Veritas and Germanischer Lloyd (DNV-GL), and Healthcare Facilities Accreditation Program (HFAP). Geographic mapping of thrombectomy capable centers and comprehensive stroke centers was performed with the ArcGIS online tool. Results: Among the three certifying organizations, standards for recognition as acute, primary, thrombectomy capable and comprehensive stroke centers are not standardized. At the time of this review, there were 1406 TJC-certified stroke centers, 241 DNV-GL certified stroke centers and 66 HFAP-certified stroke centers in the United States. Cost for certification was similar with price scaled by complexity of capabilities. Quality metrics revealed a significantly higher rate of tPA administration and shorter door-to-needle time for TJC and DNV-GL centers than HFAP. All primary stroke centers exhibited improved in-hospital, 30-day and 1-year mortality when compared to non-stroke centers. Discussion: Despite lack of standardization of criteria between organizations, certification provides a mechanism for ensuring hospitals deliver higher standards of stroke care. Understanding variations in quality and scope of different organizations enables targeting of at-risk regions to maximize access and availability of care

Management of patients with isolated acute cervical carotid artery occlusion and normal neurological exam: Technical note and case series

Objectives Limited data exists on the management and outcome of patients with isolated acute cervical internal carotid artery (cICA) occlusion presenting with normal neurologic exam after experiencing a period of neurological deficits. These patients are at risk for progressive neurologic deterioration but have not yet progressed to stroke. Current management is no intervention due to intervention risk of embolization. We aim to determine the optimal management of patients with isolated acute cICA occlusion presenting with a normal neurological exam after experiencing neurological deficits. Patients and methods Data was collected on 3 patients with acute cICA occlusion that presented with a normal neurological exam to our institution. Patient 1 was treated according to standard protocol, while patients 2 and 3 were treated according to the management discussed. Associations between perfusion imaging studies and clinical outcome were analyzed to determine stroke risk. A revascularization technique to minimize risk of distal embolization is described. Results A total of 3 consecutive patients with acute cICA occlusion were successfully revascularized. Patients 2 and 3 (66.67%) were neurologically intact post-operatively, while patient 1 (33.33%) had residual hemiparesis. It seems that MTT ≥ 200% or Tmax \u3e 6 s is the optimal penumbra threshold predicting infarction and neurologic deterioration. There were no embolic complications as a result of endovascular therapy (EVT). Conclusion Cerebral perfusion imaging of patients presenting with normal neurological exam after experiencing neurological deficits is warranted to help identify patients at risk for stroke due to collateral failure. These patients should be monitored in the ICU for neurologic deterioration and given the option of intervention if mismatch is noted on CT perfusion imaging. Perfusion studies identifying penumbra and delayed MTT ≥ 200% or Tmax \u3e 6 s are indicators for possible collateral failure. In patients undergoing intervention, we suggest a technique using proximal flow arrest to minimize risk of shower emboli. Further studies are needed to verify our findings

Improving Serial Imaging Protocols in Spontaneous Intracerebral Hemorrhage

There is no universally agreed upon protocol to image patient presenting with intra-parenchymal hemorrhage of non-traumatic etiology (sICH). At our institution, it is common practice for a patient to have 3 CT’s done within 24 hours. They are often at onset of symptoms or presentation, 6 hours post onset of symptoms, and finally 24 hours post bleed onset. The goal of this project will be to assess the safety and efficacy of obtaining this repeat imaging in our patients in the hopes that limiting unnecessary CT head studies will decrease resource utilization, decrease patient radiation, expedite movement of stable patients out of the ICU and/or disposition

Pressure versus concentration tuning of the superconductivity in Ba(Fe(1-x)Cox)2As2

In the iron arsenide compound BaFe2As2, superconductivity can be induced either by a variation of its chemical composition, e.g., by replacing Fe with Co, or by a reduction of the unit-cell volume through the application of hydrostatic pressure p. In contrast to chemical substitutions, pressure is expected to introduce no additional disorder into the lattice. We compare the two routes to superconductivity by measuring the p dependence of the superconducting transition temperature Tc of Ba(Fe(1-x)Cox)2As2 single crystals with different Co content x. We find that Tc(p) of underdoped and overdoped samples increases and decreases, respectively, tracking quantitatively the Tc(x) dependence. To clarify to which extent the superconductivity relies on distinct structural features we analyze the crystal structure as a function of x and compare the results with that of BaFe2As2 under pressure.Comment: 14 pages, 4 figures, to be published in JPSJ Vol. 79 No. 12. The copyright is held by The Physical Society of Japa

Risk of mechanical thrombectomy recanalization failure: Intraoperative nuances and the role of intracranial atherosclerotic disease

Objective: To present intraoperative observations that when recognized may facilitate the identification of patients at high risk of MT recanalization failure. We illustrate 4 cases of successful recanalization via rescue treatment with balloon angioplasty and/or stenting when such observations were noted. We also discuss the role of intracranial atherosclerotic disease in recanalization failure. Patients and methods: We conducted a retrospective review of a prospectively maintained database for 450 stroke patients and identified 122 patients who underwent MT that failed to achieve recanalization. Operative notes were reviewed, and intraoperative nuances were discussed amongst neurointerventionalists. Results: Intraoperative observations that may suggest a high risk of MT recanalization failure include resistance to microwire advancement, significant resistance to microcatheter advancement, temporary antegrade flow upon stent retriever (SR) deployment, temporary retrograde flow upon SR deployment with simultaneous aspiration, restricted SR expansion (“pinched device”), moderate resistance to total impedance of SR removal causing vessel/SR stretch on angiographic roadmap, and minimal recanalization after ≥3 device passes. Conclusion: Intraoperative observations may facilitate early recognition of patients at high risk of MT recanalization failure. We suggest considering rescue treatment when such observations are noted to avoid prolonged procedure times, futile reperfusion, and reocclusion post-MT. Intracranial balloon angioplasty and/or stenting may be a safe and effective treatment in this patient subgroup. Stent placement may be considered depending on the patient\u27s antiplatelet status, angioplasty success, and concern for intracranial hemorrhage. Further studies amongst larger patient cohorts are needed