258 research outputs found
An ovulating follicle presenting as a testicular mass in a teenage patient with ovotesticular DSD
Redox-controlled potassium intercalation into two polyaromatic hydrocarbon solids
Alkali metal intercalation into polyaromatic hydrocarbons (PAHs) has been studied intensely after reports of superconductivity in a number of potassium- and rubidium-intercalated materials. There are, however, no reported crystal structures to inform our understanding of the chemistry and physics because of the complex reactivity of PAHs with strong reducing agents at high temperature. Here we present the synthesis of crystalline K2Pentacene and K2Picene by a solid–solid insertion protocol that uses potassium hydride as a redox-controlled reducing agent to access the PAH dianions, and so enables the determination of their crystal structures. In both cases, the inserted cations expand the parent herringbone packings by reorienting the molecular anions to create multiple potassium sites within initially dense molecular layers, and thus interact with the PAH anion π systems. The synthetic and crystal chemistry of alkali metal intercalation into PAHs differs from that into fullerenes and graphite, in which the cation sites are pre-defined by the host structure
Ratio of carbon dioxide veno-arterial difference to oxygen arterial-venous difference is not associated with lactate decrease after fluid bolus in critically ill patients with hyperlactatemia: results from a prospective observational study
Background: High ratio of the carbon dioxide veno-arterial difference to the oxygen arterial-venous difference (PvaCO2/CavO2) is associated with fluid bolus (FB) induced increase in oxygen consumption (VO2). This study investigated whether PvaCO2/CavO2 was associated with decreases in blood-lactate levels FB in critically ill patients with hyperlactatemia. Methods: This prospective observational study examined adult patients in the intensive care unit (ICU) with lactate levels > 1.5 mmol/L who received FBs. Blood-lactate levels were measured before and after FB under unchanged metabolic, respiratory, and hemodynamic conditions. The primary outcome was blood-lactate levels after FB. Significant decreases in blood-lactate levels were considered as blood-lactate levels < 1.5 mmol/L or a decrease of more than 10% compared to baseline. Results: The study enrolled 40 critically ill patients, and their median concentration of blood lactate was 2.6 [IQR:1.9 − 3.8] mmol/L. There were 27 (68%) patients with PvaCO2/CavO2 ≥ 1.4 mmHg/ml, and 10 of them had an increase in oxygen consumption (dVO2) ≥ 15% after FB, while 13 (32%) patients had PvaCO2/CavO2 < 1.4 mmHg/ml before FB, and none of them had dVO2 ≥ 15% after FB. FB increased the cardiac index in patients with high and low preinfusion PvaCO2/CavO2 (13.4% [IQR: 8.3 − 20.2] vs. 8.8% [IQR: 2.9 − 17.4], p = 0.34). Baseline PvaCO2/CavO2 was not found to be associated with a decrease in blood lactate after FB (OR: 0.88 [95% CI: 0.39 − 1.98], p = 0.76). A positive correlation was observed between changes in blood lactate and baseline PvaCO2/CavO2 (r = 0.35, p = 0.02). Conclusions: In critically ill patients with hyperlactatemia, PvaCO2/CavO2 before FB cannot be used to predict decreases in blood-lactate levels after FB. Increased PvaCO2/CavO2 is associated with less decrease in blood-lactate levels
Time evolution of ground motion-dependent depolarisation at linear colliders
Future linear colliders plan to collide polarised beams and the planned
physics reach requires knowledge of the state of polarisation as precisely as
possible. The polarised beams can undergo depolarisation due to various
mechanisms. In order to quantify the uncertainty due to depolarisation, spin
tracking simulations in the International Linear Collider (ILC) Beam Delivery
System (BDS) and at the Interaction Point (IP) have been performed. Spin
tracking in the BDS was achieved using the BMAD subroutine library, and the
CAIN program was used to do spin tracking through the beam-beam collision.
Assuming initially aligned beamline elements in the BDS, a ground motion model
was applied to obtain realistic random misalignments over various time scales.
Depolarisation at the level of 0.1% occurs within a day of ground motion at a
noisy site. Depolarisation at the IP also exceeds 0.1% for the nominal
parameter sets for both the ILC and for the Compact Linear Collider (CLIC).
Theoretical work is underway to include radiative corrections in the
depolarisation processes and simulation of the depolarisation through the
entire collider is envisaged.Comment: 8 pages, 4 figures, PST09 proceedings; Proceedings of the 13th
International Workshop on Polarised Sources, Targets and Polarimetry 2009,
World Scientific 201
Disrupted-in-schizophrenia 1 overexpression disrupts hippocampal coding and oscillatory synchronization
Aberrant proteostasis of protein aggregation may lead to behavior disorders including chronic mental illnesses (CMI). Furthermore, the neuronal activity alterations that underlie CMI are not well understood. We recorded the local field potential and single‐unit activity of the hippocampal CA1 region in vivo in rats transgenically overexpressing the Disrupted‐in‐Schizophrenia 1 (DISC1) gene (tgDISC1), modeling sporadic CMI. These tgDISC1 rats have previously been shown to exhibit DISC1 protein aggregation, disturbances in the dopaminergic system and attention‐related deficits. Recordings were performed during exploration of familiar and novel open field environments and during sleep, allowing investigation of neuronal abnormalities in unconstrained behavior. Compared to controls, tgDISC1 place cells exhibited smaller place fields and decreased speed‐modulation of their firing rates, demonstrating altered spatial coding and deficits in encoding location‐independent sensory inputs. Oscillation analyses showed that tgDISC1 pyramidal neurons had higher theta phase locking strength during novelty, limiting their phase coding ability. However, their mean theta phases were more variable at the population level, reducing oscillatory network synchronization. Finally, tgDISC1 pyramidal neurons showed a lack of novelty‐induced shift in their preferred theta and gamma firing phases, indicating deficits in coding of novel environments with oscillatory firing. By combining single cell and neuronal population analyses, we link DISC1 protein pathology with abnormal hippocampal neural coding and network synchrony, and thereby gain a more comprehensive understanding of CMI mechanisms
Genome-wide linkage and association study implicates the 10q26 region as a major genetic contributor to primary nonsyndromic vesicoureteric reflux
Abstract Vesicoureteric reflux (VUR) is the commonest urological anomaly in children. Despite treatment improvements, associated renal lesions – congenital dysplasia, acquired scarring or both – are a common cause of childhood hypertension and renal failure. Primary VUR is familial, with transmission rate and sibling risk both approaching 50%, and appears highly genetically heterogeneous. It is often associated with other developmental anomalies of the urinary tract, emphasising its etiology as a disorder of urogenital tract development. We conducted a genome-wide linkage and association study in three European populations to search for loci predisposing to VUR. Family-based association analysis of 1098 parent-affected-child trios and case/control association analysis of 1147 cases and 3789 controls did not reveal any compelling associations, but parametric linkage analysis of 460 families (1062 affected individuals) under a dominant model identified a single region, on 10q26, that showed strong linkage (HLOD = 4.90; ZLRLOD = 4.39) to VUR. The ~9Mb region contains 69 genes, including some good biological candidates. Resequencing this region in selected individuals did not clearly implicate any gene but FOXI2, FANK1 and GLRX3 remain candidates for further investigation. This, the largest genetic study of VUR to date, highlights the 10q26 region as a major genetic contributor to VUR in European populations
The impact of COVID-19 on research
This article is made available for unrestricted research re-use and secondary analysis in any form or be any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.Coronavirus disease 2019 (COVID-19) has swept across the globe causing hundreds of thousands of deaths, shutting down economies, closing borders and wreaking havoc on an unprecedented scale. It has strained healthcare services and personnel to the brink in many regions and will certainly deeply mark medical research both in the short and long-term
Radiographic abnormalities, bladder interventions, and bladder surgery in the first decade of life in children with spina bifida
Background
Spina bifida (SB) patients are at increased risk for hydronephrosis, bladder storage and emptying problems, and renal failure that may require multiple bladder surgeries.
Methods
We retrospectively reviewed patients born with SB 2005–2009, presenting to our institution within 1 year of birth. Outcomes at 8–11 years old included final renal/bladder ultrasound (RBUS) results, clean intermittent catheterization (CIC) use, anticholinergic use, surgical interventions, and final renal function. We excluded those without follow-up past age 8 and/or no RBUS or fluoroscopic urodynamic images (FUI) within the first year of life. Imaging was independently reviewed by four pediatric urologists blinded to radiologists’ interpretation and initial findings compared with final outcomes.
Results
Of 98 children, 62 met inclusion criteria (48% male, 76% shunted). Median age at last follow-up was 9.6 years. Upon initial imaging, 74% had hydronephrosis (≥ SFU grade 1), decreasing to 5% at 10 years (p < 0.0001). Initially, 9% had ≥ SFU grade 3 hydronephrosis, decreasing to 2% (p = 0.13). CIC and anticholinergic use increased from 61% and 37% to 87% and 86%, respectively (p = 0.001 and p < 0.0001, respectively). With follow-up, 55% had surgical intervention and 23% had an augmentation. Of children with a serum creatinine/cystatin-C at 8–11 years old, one had confirmed chronic kidney disease (stage 2).
Conclusions
Despite initial high incidence of hydronephrosis, this was low grade and resolved in the first decade of life. Additionally, the 8–11-year incidence of kidney disease and upper tract changes was low due to aggressive medical management
Canvas: A case report
CANVAS is an acronym for cerebellar ataxia, neuropathy andvestibular areflexia syndrome that was recently described in2011. This paper reports a case of a 69 years old female thatpresented a history of dizziness for 9 years, associated withaltered vestibulo-ocular reflex (VVOR) and bilateral hypofunctiomat video head impulse test (vHIT), wicth confirmedCANVA syndrome. Imbalance is a consistent symptom ofCANVAS and, in most cases, it is the first to manifest. Itspresentation demonstrates the importance of the specialist’sneed for knowledge of this clinical condition to enable anassertive diagnosis
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