scholarly journals Survey of Gravitationally lensed Objects in HSC Imaging (SuGOHI)

2020 ◽  
Vol 636 ◽  
pp. A87 ◽  
Author(s):  
James H. H. Chan ◽  
Sherry H. Suyu ◽  
Alessandro Sonnenfeld ◽  
Anton T. Jaelani ◽  
Anupreeta More ◽  
...  
Keyword(s):  
Galaxy Evolution ◽  
Emission Lines ◽  
High Grade ◽  
Upper Limit ◽  
Powerful Means ◽  
Flux Intensity ◽  
Modeling Software ◽  
Lens Modeling ◽  
Strategic Program

Strong gravitationally lensed quasars provide a powerful means to study galaxy evolution and cosmology. We use CHITAH, which is an algorithm used to hunt for new lens systems, particularly lensed quasars, in the Hyper Suprime-Cam Subaru Strategic Program (HSC SSP) S16A. We present 46 lens candidates, of which 3 are previously known. We select four high-grade candidates from CHITAH for spectroscopic follow-up observations, and include two additional lenses found by YATTALENS, an algorithm used to classify lensed galaxies. We obtain X-shooter spectra of these six promising candidates for lens confirmation and redshift measurements. We report new spectroscopic redshift measurements for both the lens and source galaxies in four lens systems. We apply the lens modeling software GLEE to model our six X-shooter lenses uniformly. Through our analysis of the HSC images, we find that HSCJ022622−042522, HSCJ115252+004733, and HSCJ141136−010216 have point-like lensed images, and that the lens light distribution is well aligned with the lens mass distribution within 6 deg. We estimate the fluxes of the lensed source emission lines using X-shooter spectra, and use line ratio as a diagnostic on the Baldwin-Phillips-Terlevich (BPT) diagram. As a result, we find that HSCJ022622−042522 has a probable quasar source based on the upper limit of the [N II] flux intensity. We also measure the FWHM of Lyα emission of HSCJ141136−010216 to be ∼233 km s−1, showing that it is a probable Lyman-α emitter.

scholarly journals High-grade astrocytoma with piloid features (HGAP): the Charité experience with a new central nervous system tumor entity

2021 ◽  
Author(s):  
Katja Bender ◽  
Eilís Perez ◽  
Mihaela Chirica ◽  
Julia Onken ◽  
Johannes Kahn ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Central Nervous System ◽  
Nervous System ◽  
World Health ◽  
Central Nervous System Tumor ◽  
High Grade ◽  
Thoracic Spinal Cord ◽  
High Grade Astrocytoma ◽  
Tumor Entity

Abstract Purpose High-grade astrocytoma with piloid features (HGAP) is a recently described brain tumor entity defined by a specific DNA methylation profile. HGAP has been proposed to be integrated in the upcoming World Health Organization classification of central nervous system tumors expected in 2021. In this series, we present the first single-center experience with this new entity. Methods During 2017 and 2020, six HGAP were identified. Clinical course, surgical procedure, histopathology, genome-wide DNA methylation analysis, imaging, and adjuvant therapy were collected. Results Tumors were localized in the brain stem (n = 1), cerebellar peduncle (n = 1), diencephalon (n = 1), mesencephalon (n = 1), cerebrum (n = 1) and the thoracic spinal cord (n = 2). The lesions typically presented as T1w hypo- to isointense and T2w hyperintense with inhomogeneous contrast enhancement on MRI. All patients underwent initial surgical intervention. Three patients received adjuvant radiochemotherapy, and one patient adjuvant radiotherapy alone. Four patients died of disease, with an overall survival of 1.8, 9.1, 14.8 and 18.1 months. One patient was alive at the time of last follow-up, 14.6 months after surgery, and one patient was lost to follow-up. Apart from one tumor, the lesions did not present with high grade histology, however patients showed poor clinical outcomes. Conclusions Here, we provide detailed clinical, neuroradiological, histological, and molecular pathological information which might aid in clinical decision making until larger case series are published. With the exception of one case, the tumors did not present with high-grade histology but patients still showed short intervals between diagnosis and tumor progression or death even after extensive multimodal therapy.

Discovery of five new Galactic symbiotic stars in the VPHAS+ survey

2021 ◽  
Vol 502 (2) ◽  
pp. 2513-2517
Author(s):  
Stavros Akras ◽  
Denise R Gonçalves ◽  
Alvaro Alvarez-Candal ◽  
Claudio B Pereira
Keyword(s):  
Spectroscopic Data ◽  
Selection Criterion ◽  
Optical Spectra ◽  
Emission Lines ◽  
High Rate ◽  
Symbiotic Stars ◽  
Selection Of

ABSTRACT We report the validation of a recently proposed infrared (IR) selection criterion for symbiotic stars (SySts). Spectroscopic data were obtained for seven candidates, selected from the SySt candidates of Akras et al. by employing the new supplementary IR selection criterion for SySts in the VST/OmegaCAM Photometric H-Alpha Survey. Five of them turned out to be genuine SySts after the detection of H α, He ii, and [O iii] emission lines as well as TiO molecular bands. The characteristic O vi Raman-scattered line is also detected in one of these SySts. According to their IR colours and optical spectra, all five newly discovered SySts are classified as S-type. The high rate of true SySts detections of this work demonstrates that the combination of the H α emission and the new IR criterion improves the selection of target lists for follow-up observations by minimizing the number of contaminants and optimizing the observing time.

scholarly journals Cumulative incidence and risk factors for radiation induced leukoencephalopathy in high grade glioma long term survivors

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Robert Terziev ◽  
Dimitri Psimaras ◽  
Yannick Marie ◽  
Loic Feuvret ◽  
Giulia Berzero ◽  
...  
Keyword(s):  
Risk Factors ◽  
Cumulative Incidence ◽  
High Grade Glioma ◽  
High Grade ◽  
Nucleotide Polymorphisms ◽  
Increased Risk ◽  
Radiation Induced ◽  
Long Term Survivors

AbstractThe incidence and risk factors associated with radiation-induced leukoencephalopathy (RIL) in long-term survivors of high-grade glioma (HGG) are still poorly investigated. We performed a retrospective research in our institutional database for patients with supratentorial HGG treated with focal radiotherapy, having a progression-free overall survival > 30 months and available germline DNA. We reviewed MRI scans for signs of leukoencephalopathy on T2/FLAIR sequences, and medical records for information on cerebrovascular risk factors and neurological symptoms. We investigated a panel of candidate single nucleotide polymorphisms (SNPs) to assess genetic risk. Eighty-one HGG patients (18 grade IV and 63 grade III, 50M/31F) were included in the study. The median age at the time of radiotherapy was 48 years old (range 18–69). The median follow-up after the completion of radiotherapy was 79 months. A total of 44 patients (44/81, 54.3%) developed RIL during follow-up. Twenty-nine of the 44 patients developed consistent symptoms such as subcortical dementia (n = 28), gait disturbances (n = 12), and urinary incontinence (n = 9). The cumulative incidence of RIL was 21% at 12 months, 42% at 36 months, and 48% at 60 months. Age > 60 years, smoking, and the germline SNP rs2120825 (PPARg locus) were associated with an increased risk of RIL. Our study identified potential risk factors for the development of RIL (age, smoking, and the germline SNP rs2120825) and established the rationale for testing PPARg agonists in the prevention and management of late-delayed radiation-induced neurotoxicity.

scholarly journals Survey of Gravitationally Lensed Objects in HSC Imaging (SuGOHI) – VII. Discovery and confirmation of three strongly lensed quasars†

2021 ◽  
Vol 502 (1) ◽  
pp. 1487-1493
Author(s):  
Anton T Jaelani ◽  
Cristian E Rusu ◽  
Issha Kayo ◽  
Anupreeta More ◽  
Alessandro Sonnenfeld ◽  
...  
Keyword(s):  
Spectroscopic Data ◽  
Point Sources ◽  
Sloan Digital Sky Survey ◽  
Early Type ◽  
Blue Point ◽  
X Ray ◽  
Quasar Spectra ◽  
Strategic Program ◽  
Early Type Galaxy

ABSTRACT We present spectroscopic confirmation of three new two-image gravitationally lensed quasars, compiled from existing strong lens and X-ray catalogues. Images of HSC J091843.27–022007.5 show a red galaxy with two blue point sources at either side, separated by 2.26 arcsec. This system has a source and a lens redshifts zs = 0.804 and zℓ = 0.459, respectively, as obtained by our follow-up spectroscopic data. CXCO J100201.50+020330.0 shows two point sources separated by 0.85 arcsec on either side of an early-type galaxy. The follow-up spectroscopic data confirm the fainter quasar has the same redshift with the brighter quasar from the Sloan Digital Sky Survey (SDSS) fiber spectrum at zs = 2.016. The deflecting foreground galaxy is a typical early-type galaxy at a redshift of zℓ = 0.439. SDSS J135944.21+012809.8 has two point sources with quasar spectra at the same redshift zs = 1.096, separated by 1.05 arcsec, and fits to the HSC images confirm the presence of a galaxy between these. These discoveries demonstrate the power of the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP)’s deep imaging and wide sky coverage. Combined with existing X-ray source catalogues and follow-up spectroscopy, the HSC-SSP provides us unique opportunities to find multiple-image quasars lensed by a foreground galaxy.

scholarly journals Oral Abstract

2016 ◽  
Author(s):  
Dharma Ram
Keyword(s):  
Survival Data ◽  
Eligible Patient ◽  
Stage Iv ◽  
Endometrial Stromal Sarcoma ◽  
Uterine Sarcoma ◽  
Low Grade ◽  
Uterine Leiomyosarcoma ◽  
High Grade ◽  
Lost To Follow Up

Introduction: Uterine sarcoma accounts for nearly 3% of all uterine malignancies. They have 4 major pathology includes endometrial stromal sarcoma high grade, ESS low grade, uterine leiomyosarcoma (uLMS) and undifferentiated uterine sarcoma (UUS). Recent WHO classification 2014, recognizes low grade ESS and high grade ESS as distinct entity. They differ from endometrial carcinoma in their aggressive nature and poor prognosis. We review our database and found total 44 eligible patient treated at our institute. Materials and Methods: Its retrospective analysis of computer based database of our institute from January 2009 to December 2015. We analyzed demographic, pathological, treatment and survival data. Results: Total 44 patient treated for uterine sarcoma at our institute. Among these 16 were operated at our institute during study period. Here we reporting results of operated patients at our institute. The histological diagnosis LMS (5/16), ESS-L (4/16), MMMT (3/16), UUS (3/16) and ESS-H (1/16). Stage distribution was stage I, (6/16) stage II, (5/16) stage III, (3/16) stage IV, (0/16) and unknown stage (2/16). Two patients underwent completion surgery for outside myomectomy. The adjuvant treatment was CT in 3/16, CT with RT in 7/16, HT in 4/16 and one lost to follow up with one was put on observation. Median follow up is 30 month with 14 patients alive and one lost to follow up. At last follow up 4 patients alive with metastatic disease and 10 patients alive with no evidence of disease. Conclusion: Uterine sarcoma are uncommon disease with

Enhanced Fiber Tractography Using Edema Correction: Application and Evaluation in High-Grade Gliomas

Neurosurgery ◽  
2021 ◽  
Author(s):  
Fraser Henderson Jr ◽  
Drew Parker ◽  
Anupa A Vijayakumari ◽  
Mark Elliott ◽  
Timothy Lucas ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Diffusion Tensor ◽  
Free Water ◽  
High Grade Glioma ◽  
Fiber Tracking ◽  
High Grade ◽  
Peritumoral Edema ◽  
Fiber Tractography ◽  
Motor Pathways

Abstract BACKGROUND A limitation of diffusion tensor imaging (DTI)-based tractography is peritumoral edema that confounds traditional diffusion-based magnetic resonance metrics. OBJECTIVE To augment fiber-tracking through peritumoral regions by performing novel edema correction on clinically feasible DTI acquisitions and assess the accuracy of the fiber-tracks using intraoperative stimulation mapping (ISM), task-based functional magnetic resonance imaging (fMRI) activation maps, and postoperative follow-up as reference standards. METHODS Edema correction, using our bi-compartment free water modeling algorithm (FERNET), was performed on clinically acquired DTI data from a cohort of 10 patients presenting with suspected high-grade glioma and peritumoral edema in proximity to and/or infiltrating language or motor pathways. Deterministic fiber-tracking was then performed on the corrected and uncorrected DTI to identify tracts pertaining to the eloquent region involved (language or motor). Tracking results were compared visually and quantitatively using mean fiber count, voxel count, and mean fiber length. The tracts through the edematous region were verified based on overlay with the corresponding motor or language task-based fMRI activation maps and intraoperative ISM points, as well as at time points after surgery when peritumoral edema had subsided. RESULTS Volume and number of fibers increased with application of edema correction; concordantly, mean fractional anisotropy decreased. Overlay with functional activation maps and ISM-verified eloquence of the increased fibers. Comparison with postsurgical follow-up scans with lower edema further confirmed the accuracy of the tracts. CONCLUSION This method of edema correction can be applied to standard clinical DTI to improve visualization of motor and language tracts in patients with glioma-associated peritumoral edema.

Intervention for unruptured high-grade intracranial dural arteriovenous fistulas: a multicenter study

2021 ◽  
pp. 1-9
Author(s):  
Ching-Jen Chen ◽  
Thomas J. Buell ◽  
Dale Ding ◽  
Ridhima Guniganti ◽  
Akash P. Kansagra ◽  
...  
Keyword(s):  
Arteriovenous Fistula ◽  
Dural Arteriovenous Fistula ◽  
Intervention Group ◽  
Group Versus ◽  
Symptomatic Improvement ◽  
High Grade ◽  
Type Ii ◽  
Risk Of Death ◽  
All Cause Mortality

OBJECTIVE The risk-to-benefit profile of treating an unruptured high-grade dural arteriovenous fistula (dAVF) is not clearly defined. The aim of this multicenter retrospective cohort study was to compare the outcomes of different interventions with observation for unruptured high-grade dAVFs. METHODS The authors retrospectively reviewed dAVF patients from 12 institutions participating in the Consortium for Dural Arteriovenous Fistula Outcomes Research (CONDOR). Patients with unruptured high-grade (Borden type II or III) dAVFs were included and categorized into four groups (observation, embolization, surgery, and stereotactic radiosurgery [SRS]) based on the initial management. The primary outcome was defined as the modified Rankin Scale (mRS) score at final follow-up. Secondary outcomes were good outcome (mRS scores 0–2) at final follow-up, symptomatic improvement, all-cause mortality, and dAVF obliteration. The outcomes of each intervention group were compared against those of the observation group as a reference, with adjustment for differences in baseline characteristics. RESULTS The study included 415 dAVF patients, accounting for 29, 324, 43, and 19 in the observation, embolization, surgery, and SRS groups, respectively. The mean radiological and clinical follow-up durations were 21 and 25 months, respectively. Functional outcomes were similar for embolization, surgery, and SRS compared with observation. With observation as a reference, obliteration rates were higher after embolization (adjusted OR [aOR] 7.147, p = 0.010) and surgery (aOR 33.803, p < 0.001) and all-cause mortality was lower after embolization (imputed, aOR 0.171, p = 0.040). Hemorrhage rates per 1000 patient-years were 101 for observation versus 9, 22, and 0 for embolization (p = 0.022), surgery (p = 0.245), and SRS (p = 0.077), respectively. Nonhemorrhagic neurological deficit rates were similar between each intervention group versus observation. CONCLUSIONS Embolization and surgery for unruptured high-grade dAVFs afforded a greater likelihood of obliteration than did observation. Embolization also reduced the risk of death and dAVF-associated hemorrhage compared with conservative management over a modest follow-up period. These findings support embolization as the first-line treatment of choice for appropriately selected unruptured Borden type II and III dAVFs.

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