bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two Wolf–Rayet stars at the heart of colliding-wind binary Apep
Authors: Callingham J R , Crowther P A , Williams P M , Tuthill P G , Han Y , Pope B J S , Marcote B 
Published: May 2020

ABSTRACT
Infrared imaging of the colliding-wind binary Apep has revealed a spectacular dust plume with complicated internal dynamics that challenges standard colliding-wind binary physics. Such challenges can be potentially resolved if a rapidly rotating Wolf–Rayet star is located at the heart of the system, implicating Apep as a Galactic progenitor system to long-duration gamma-ray bursts. One of the difficulties in interpreting the dynamics of Apep is that the spectral composition of the stars in the system was unclear. Here, we present visual to near-infrared spectra that demonstrate that the central component of Apep is composed of two classical Wolf–Rayet stars of carbon- (WC8) and nitrogen-sequence (WN4-6b) subtypes. We argue that such an assignment represents the strongest case of a classical Wolf–Rayet+Wolf–Rayet binary system in the Milky Way. The terminal line-of-sight wind velocities of the WC8 and WN4-6b stars are measured to be 2100 ± 200 and 3500 ± 100 km s−1, respectively. If the mass-loss rate of the two stars are typical for their spectral class, the momentum ratio of the colliding winds is expected to be ≈0.4. Since the expansion velocity of the dust plume is significantly smaller than either of the measured terminal velocities, we explore the suggestion that one of the Wolf–Rayet winds is anisotropic. We can recover a shock-compressed wind velocity consistent with the observed dust expansion velocity if the WC8 star produces a significantly slow equatorial wind with a velocity of ≈530 km s−1. Such slow wind speeds can be driven by near-critical rotation of a Wolf–Rayet star.
Cool-core cycles and Phoenix
Authors: Prasad Deovrat , Sharma Prateek , Babul Arif , Voit Gerard M , O’Shea Brian W 
Published: May 2020

ABSTRACT
Recent observations show that the star formation rate (SFR) in the Phoenix cluster’s central galaxy is ∼500 M⊙ yr−1. Even though Phoenix is a massive cluster (M200 ≈ 2.0 × 1015 M⊙; z ≈ 0.6) such a high central SFR is not expected in a scenario in which feedback from an active galactic nucleus (AGN) maintains the intracluster medium in a state of rough thermal balance. It has been argued that either AGN feedback saturates in very massive clusters or the central supermassive black hole is too small to produce enough kinetic feedback and hence is unable to quench the catastrophic cooling. In this work, we present an alternate scenario wherein intense short-lived cooling and star formation phases followed by strong AGN outbursts are part of the AGN feedback loop. Using results from a 3D hydrodynamic simulation of a standard cool-core cluster (M200 ∼ 7 × 1014 M⊙; z = 0), scaled to account for differences in mass and redshift, we argue that Phoenix is at the end of a cooling phase in which an AGN outburst has begun but has not yet arrested core cooling. This state of high cooling rate and star formation is expected to last for ≲100 Myr in Phoenix.
A binning-free method reveals a continuous relationship between galaxies’ AGN power and offset from main sequence
Authors: Grimmett L P , Mullaney J R , Bernhard E P , Harrison C M , Alexander D M , Stanley F , Masoura V A , Walters K 
Published: May 2020

ABSTRACT
Studies investigating the relationship between active galactic nucleus (AGN) power and the star formation rates (SFRs) of their host galaxies often rely on averaging techniques – such as stacking – to incorporate information from non-detections. However, averages, and especially means, can be strongly affected by outliers and can therefore give a misleading indication of the ‘typical’ case. Recently, a number of studies have taken a step further by binning their sample in terms of AGN power (approximated by the 2–10 keV luminosity of the AGN), and investigating how the SFR distribution differs between these bins. These bin thresholds are often weakly motivated, and binning implicitly assumes that sources within the same bin have similar (or even identical) properties. In this paper, we investigate whether the distribution of host SFRs – relative to the locus of the star-forming main sequence (i.e. RMS) – changes continuously as a function of AGN power. We achieve this by using a hierarchical Bayesian model that completely removes the need to bin in AGN power. In doing so, we find strong evidence that the RMS distribution changes with 2–10 keV X-ray luminosity. The results suggest that higher X-ray luminosity AGNs have a tighter physical connection to the star-forming process than lower X-ray luminosity AGNs, at least within the 0.8 &lt; z &lt; 1.2 redshift range considered here.
An obscured AGN population hidden in the VIPERS galaxies: identification through spectral energy distribution decomposition
Authors: Pouliasis E , Mountrichas G , Georgantopoulos I , Ruiz A , Yang M , Bonanos A Z 
Published: May 2020

ABSTRACT
The detection of X-ray emission constitutes a reliable and efficient tool for the selection of active galactic nuclei (AGNs), although it may be biased against the most heavily absorbed AGNs. Simple mid-infrared (IR) broad-band selection criteria identify a large number of luminous and absorbed AGNs, yet again host contamination could lead to non-uniform and incomplete samples. Spectral energy distribution (SED) decomposition is able to decouple the emission from the AGN versus that from star-forming regions, revealing weaker AGN components. We aim to identify the obscured AGN population in the VIMOS Public Extragalactic Redshift Survey in the Canada–France–Hawaii Telescope Legacy Survey W1 field through SED modelling. We construct SEDs for 6860 sources and identify 160 AGNs at a high confidence level using a Bayesian approach. Using optical spectroscopy, we confirm the nature of ∼85 per cent of the AGNs. Our AGN sample is highly complete (∼92 per cent) compared to mid-IR colour-selected AGNs, including a significant number of galaxy-dominated systems with lower luminosities. In addition to the lack of X-ray emission (80 per cent), the SED fitting results suggest that the majority of the sources are obscured. We use a number of diagnostic criteria in the optical, IR, and X-ray regimes to verify these results. Interestingly, only 35 per cent of the most luminous mid-IR-selected AGNs have X-ray counterparts suggesting strong absorption. Our work emphasizes the importance of using SED decomposition techniques to select a population of type II AGNs, which may remain undetected by either X-ray or IR colour surveys.
On the settling of small grains in dusty discs: analysis and formulae
Authors: Laibe Guillaume , Bréhier Charles-Edouard , Lombart Maxime 
Published: May 2020

ABSTRACT
Instruments achieve sharper and finer observations of micrometre-in-size dust grains in the top layers of young stellar discs. To provide accurate models, we revisit the theory of dust settling for small grains, when gas stratification, dust inertia, and finite correlation times for the turbulence should be handled simultaneously. We start from a balance of forces and derive distributions at steady state. Asymptotic expansions require caution since limits do not commute. In particular, non-physical bumpy distributions appear when turbulence is purely diffusive. This excludes very short correlation times for real discs, as predicted by numerical simulations.
The Relationship Between Vestibular Sensory Integration and Prosthetic Mobility in Community Ambulators With Unilateral Lower Limb Amputation
Authors: Lučarević Jennifer , Gaunaurd Ignacio , Clemens Sheila , Belsky Paulina , Summerton Lauren , Walkup Melody , Wallace Stephen Paden , Yokomizo Lori , Pasquina Paul , Applegate E Brooks , Schubert Michael C , Gailey Robert S 
Published: May 2020

Abstract

Objective
The modified Clinical Test of Sensory Interaction and Balance (mCTSIB) is used to clinically assess vestibular sensory integration (VSI), the process by which the central nervous system integrates vestibular afference to maintain balance. The rate and effects of impaired VSI (IVSI) on prosthetic mobility in people with lower limb amputation (LLA) is unknown. The objective of this study was to use the mCTSIB to classify VSI in active community ambulators with LLA and to examine the relationship between IVSI and prosthetic mobility, as measured by the Component Timed Up and Go (cTUG) test.

Methods
This was a cross-sectional study with a convenience sample of 130 community ambulators with unilateral LLA. Classification of VSI was determined based on a time-based pass/fail mCTSIB performance. Participants were classified as having normal sensory integration (NSI) if they could balance for 30 seconds in every mCTSIB condition. Participants who failed condition 4 exclusively were classified as IVSI. Prosthetic mobility, as measured by the cTUG, was compared between NSI and IVSI groups.

Results
Of the 130 participants, 29 (22%) were classified as IVSI and 95 (73%) were classified as having NSI. Prosthetic mobility significantly differed between IVSI and NSI groups, with IVSI participants performing all components of the cTUG significantly slower. Medium to large effect sizes were found between groups during cTUG.

Conclusions
These results suggest that 1 in 5 community ambulators with LLA have IVSI, with associated limitations in balance confidence and prosthetic mobility.

Impact
The ability to integrate vestibular information was found to have a strong relationship with prosthetic mobility in active community ambulators with LLA, especially with performing a 180-degree step turn. Physical therapists can use the mCTSIB to classify sensory integration during prosthetic rehabilitation and develop an appropriate balance intervention.

Lay Summary
Active adults with LLA can use information from their senses to maintain their standing balance. Adults with LLA who have difficulty balancing on foam with closed eyes were slower to get in and out of a chair, walk, and perform a 180-degree step turn.
Effect of Low Dose Insulin Therapy on Normoglycemic Critically Ill Patients in Intensive Care Units
Authors: Kamel A M , Hosny M R , Awad M O , Eid A M 
Published: May 2020

Abstract

Background
Insulin has anti-inflammatory effect and vasodilatory effect via endothelial NO release in arteries, veins and capillaries. Insulin inhibits release of inflammatory mediators like IL-6, TNF-α and enhances the immune function of monocytes. Stress-induced hyperglycemia is very common in the ICU, being detected in 50–85% of critically ill patients. It is defined as a blood glucose level &gt;140 mg/dL or glycated hemoglobin (HbA1c) &gt; 6.5 without a past history of pre-existing diabetes.

Aim of the Work
to evaluate the effect of low dose insulin therapy on the clinical progression of organ dysfunction and on the level of C-reactive protein (CRP), procalcitonin and lipid profile in patients known to be normoglycemic complaining of systemic inflammatory response syndrome (SIRS) or sepsis in intensive care unit.

Patients and Methods
The study was conducted on 60 patients which were randomized into 2 groups: 30 patients received moderate insulin therapy (group 1) and 30 patients received iv infusion of placebo (normal saline 0.9% NaCl) during the course of the study (group 2).

Results
There was an improvement in blood pressure, heart rate and body temperature in group 1 compared to group 2 and throughout the study period in group 1. CRP and lactate levels were declined in group 1 with better creatinine values. Triglycerides were decreased in group 1 and hypoxic index was higher in group 1 compared to group 2.

Conclusion
Insulin therapy with target blood glucose (120-140 mg/dL) has been found in our study that it reduces the complications of SIRS and organ failure, which was expressed by the gradual improvement in heart rate, means arterial blood pressure, body temperature, serum lactate level and urine output. These results support the hypothesis that insulin has a positive inotropic effect.

Recommendations
Future studies are required to compare between moderate insulin therapy with target blood glucose (120 – 140 mg/dL) and intensive insulin therapy with target blood glucose (80-110 mg/dL) as regard patients' mortality and morbidity.
Efficacy of perineural versus systemic dexamethasone in prolonging analgesia after ultrasound guided femoral and sciatic nerve block for patients undergoing below knee surgeries
Authors: Abdelaziz A A , Elzahaby H M , Elshebeiny A A , Heiba D M 
Published: May 2020

Abstract

Background
Poorly controlled acute pain after surgery is associated with a variety of unwanted postoperative consequences, including patient suffering, distress, myocardial ischemia, prolonged hospital stay and increase of chronic pain. Neuroaxial block is used for postoperative pain management and decrease analgesic use.

Objective
to compare the analgesic efficacy of both, intravenous and perineural administration of dexamethasone during femoral and sciatic nerve block using bupivacaine in patients undergoing below knee surgeries.

Patients and Methods
In our study, 50 patients were randomly divided into two equal groups: Group A (Perineural Dexamethasone group) [n = 25]: Those cases received 2ml volume of dexamethasone (8mg) combined with the 20 ml of bupivacaine of 0.5% concentration in each block, followed by injecting 5 ml saline intravenous. Group B (Systemic Dexamethasone group) [n = 25]: Those cases received 2 ml of dexamethasone (8mg) diluted over 3 cm saline in a 5 ml syringe following injection of the perineural 20 ml bupivacaine (0.5%) combined with 2 ml saline to have the same syringe volume for each block.

Results
Our study showed that onset time for sensory block was (25.39 ± 3.79) mins for systemic group and (18.85 ± 4.11) mins in perineural group with a significant statistical difference (P &lt; 0.001) between both groups as the onset of sensory block in perineural group was significantly shorter than the systemic group and the duration of sensory block was (650.00 ± 62.8) mins in systemic group and (718.52 ± 62.06) mins in perineural group. The duration of sensory block was significantly shorter in systemic group than in perineural group with statistically high significant difference between groups (P &lt; 0.001). Onset time for motor block was (30.61 ± 4.89) mins in systemic group and (27.59 ± 3.31) mins in perineural group. Perineural group had shorter time of onset than systemic dexamethasone group with a significant difference between groups (P = 0.013). The duration of analgesia was significantly longer in perineural group than systemic group (P &lt; 0.001)

Conclusion
Dexamethasone was seen to be a potent adjunct to local anesthetic to prolong post operative analgesia with negligible side effects & better outcome to the perineural route.
Dexamethasone with Local Anesthetics Versus Local Anesthetics Alone in Supraclavicular Brachial Plexus Block in Upper Limb Surgeries
Authors: Elshaer A N , Said S G A , Alawady D S , Reyad A M 
Published: May 2020

Abstract

Background
Poorly controlled acute pain after surgery is associated with a variety of unwanted postoperative consequences, including patient suffering, distress, myocardial ischemia, prolonged hospital stays and an increased likelihood of chronic pain. Systemic analgesics (opioids and non-opioids) have long been used for postoperative pain, then neuroaxial or peripheral nerve blocks were employed. Local anesthetics alone were used, then various adjuvants were added to achieve quick, dense and prolonged block.

Objective
The aim of this study was to study the effect of dexamethasone as an adjuvant to bupivacaine in supraclavicular brachial plexus block. The comparison included the onset and the duration of the sensory and motor blocks, the duration of analgesia of the block as well as their effects on the postoperative analgesic requirements. The effect of the drugs on hemodynamics and monitoring the occurrence of any complication were also done.

Patients and Methods
In our study, 60 patients were randomly divided into 2 equal groups. Control group received bupivacaine only (0.5%) and dexa group in which 8 mg of dexamethasone were added to bupivacaine. All patients received equal volumes of 20 milliliters.

Results
Our study showed that addition of 8 milligrams of dexamethasone to bupivacaine in ultrasound-guided supraclavicular nerve block shortened the onset times of motor blocks and significantly prolonged motor and sensory block durations. In addition, dexamethasone prolonged the duration of analgesia of the plexus block significantly, as proved by the time of request of analgesia. Moreover, in dexa group, postoperative analgesic requirements were greatly lesser than that of bupivacaine groups. Addition of dexamethasone also did not affect the hemodynamics to a significant level. This makes dexamethasone with bupivacaine more superior than the use of bupivacaine alone.

Conclusion
Addition of dexamethasone to bupivacaine in supraclavicular nerve block shortened the onset motor blocks. Addition of dexamethasone to bupivacaine significantly prolongs of both sensory and motor block durations.
Comparison between Bupivacaine with Neostigmine and Bupivacaine alone in Caudal Block for Pediatrics undergoing Lower Abdominal Surgery
Authors: Hassan B E E , Abdelhamid H S , Elderh M S , Sharaf A I A 
Published: May 2020

Abstract

Background
Peripheral nerve blocks provide prolonged analgesia restricted to the site of surgery e.g. penile block for circumcision or sciatic nerve block for pediatric surgery. The drawback is not all anesthesiologists are familiar with the necessary spectrum of peripheral nerve blocks in children. That is why Caudal block is preferred as all types of surgery below the umbilicus can be covered by it: ‘one technique fits all’. The main goal of caudal block is to provide postoperative pain relief, in addition it can be effective intraoperative and it is accepted that the block is performed in anesthetized children.

Objectives
The aim of this work is to compare Bupivacaine with Neostigmine and Bupivacaine alone as regard intraoperative hemodynamics and postoperative pain control for lower abdominal surgery in pediatrics.

Patients and Methods
Prospective randomized controlled clinical Trial.

Conclusion
In conclusion, caudal bupivacaine plus 2μg/kg neostigmine provided excellent analgesia lasting up to 24 hours post-operative, without serious side effects and minimal additional analgesics thus providing a safe, simple and effective postoperative analgesia for children undergoing lower abdominal surgery.
A Comparative Study Between Magnesium Sulfate Versus Morphine Added to Bupivacaine in Ultra-Sound Guided Transversus Abdominis Plane Block for Post-Operative Analgesia after Inguinal Herniorraphy
Authors: Kamaly A M , Khamies A M , Hassan R M , Tawfik H A H 
Published: May 2020

Abstract

Background
Inguinal hernia considered the third common disease in surgeries for adult after acute appendicitis and proctologic disorders. About 20 millions of inguinal hernia repairs are performed globally. Inguinal herniorrhaphy is frequently associated with persistent postoperative pain. A significant proportion of pain experienced by patients undergoing abdominal surgeries is related to somatic pain signals derived from the abdominal wall.

Aim of the Work
The aim of this study is to assess the postoperative analgesic efficacy of Magnesium sulfate added to Bupivacine verus Morphine to Bupivacaine in ultrasound guided transversus abdominis plane (TAP) block after inguinal herniorraphy regarding the pain relief and the amount of rescue analgesia used postoperative.

Patients and Methods
The study was conducted on 45 randomly chosen patients in Ain Shams University Hospitals after approval of the medical ethical committee. They were allocated in three groups of 15 patients each: Group - I (B): received TAP block with Bupivacaine only as a “Control Group”. Group - II (B-MO): received TAP Block with Bupivacaine plus Morphine. Group - III (B-Mg): received TAP block with Bupivacaine plus Magnesium Sulfate. The three groups were adequately monitored and assessed intra- and post-operatively and they were compared regarding analgesic outcome by using the visual analogue scaling system, besides, recording time for first call for rescue analgesia and total consumption of it in the 1st 24 postoperative hours. Demographic data and post-operative hemodynamics were also assessed.

Results
The results of the study revealed that Magnesium added to bupivacaine better than Morphine added to Bupivacaine in transversus abdominis plane block regarding the postoperative analgesia after inguinal Herniorraphy.

Conclusion
In Conclusion the addition of MgSo4 as an adjuvant to bupivacaine in TAP block has shown superiority over either mono-therapy with bupivacaine or bupivacaine-Morphine combination in many aspects such as postoperative analgesic outcome assessed by VAS score, 1st time of rescue analgesia and without the pronounced side effects of the conventional postoperative opioids and less side effect than Morphine.
Comparison between Intrathecal Nalbuphine and Bupivacaine versus Fentanyl and Bupivacaine For Postoperative Analgesia After Lower Abdominal Surgeries
Authors: Ibrahim S F , Ataallah R Y , Abdelmalek F A , Hamisa M M 
Published: May 2020

Abstract

The use of opioids in intrathecal or epidural anesthesia has become popular to optimize postoperative analgesia. However, opioid-induced side effects, such as respiratory depression, nausea, vomiting, urinary retention and pruritus, limit their use. Several investigations have shown that intrathecal or epidural administration of opioids produces a dose dependent modulation of spinal nociceptive processing in animals and humans and is not associated with sedation.

Aim of Study
The purpose of this study was to assess the spinally mediated analgesic effects postoperativally of intrathecal Nalbuphine plus bupivacaine after lower abdominal surgeries in comparison to intrathecal bupivacaine plus fentanyl
Patients & Methods : 60 patients came to Ain-shams Hospital for lower abdominal surgeries, They were randomly allocated into two equal groups (30 patients each) group F and group N. Group F :

Bupivacaine-Fentanyl
Patients received an intrathecal injection of 3 ml of 0.5% heavy (hyperbaric) bupivacaine plus 0.5 ml (25 µg) fentanyl. Group N: Bupivacaine-Nalbuphin Patients received an intrathecal injection of 3 ml of 0.5% heavy (hyperbaric) bupivacaine plus 0.5 ml (0.5 mg) Nalbuphine. All patients were assessed and monitored for: Hemodynamics: ECG for heart rate, and non-invasive arterial pressure, respiratory rate and arterial oxygen saturation, onset of sensory block, onset of motor block, duration of analgesia & 1st rescue analgesia, duration of motor block, adverse effects as: hypotension, bradycardia, respiratory depression, pruritus, shivering, nausea and vomiting were recorded.

Results & Conclusion
Addition of a small dose of nalbuphine or fentanyl to bupivacaine in spinal anesthesia moderately prolonged the time of postoperative analgesia the duration of postoperative analgesia is nearly the same in nalbuphine group & the fentanyl group. There is more rapid onset of motor block in fentanyl group than in nalbuphine group but with no difference in sensory or motor block regression. No respiratory depression or degree of sedation occurs in both groups. Hemodynamic stability & side effects incidence are the same in both groups