We describe the fabrication and characterization of photoconductors in which an ensemble of indium phosphide nanoneedles was utilized. DC electrical transport properties of the fabricated ...photoconductors were characterized under illumination with monochromatic light at 633 nm. This is the first demonstration of III-V compound semiconductor nanometerscale structures monolithically integrated on non-single crystalline silicon-based materials as an optoelectronic device that can be fabricated by a simple and flexible process not limited by single crystal substrates.
Objective: Patients with aortic dissection were studied to define (1) anatomic and physiologic derangements in renal artery blood flow, (2) differences in clinically suspected renal malperfusion and ...true functional malperfusion, and (3) variations in endovascular interventions for the treatment of renal malperfusion. Methods: The cohort comprised 165 patients (mean age, 58 years) with dissections who were thought to have malperfusion sufficient to require arteriography. They were treated from 1996 to 2004 for acute (n = 115) or chronic (n = 50) aortic dissections (75 had type A, 90 had type B lesions). All patients had suspected peripheral vascular malperfusion (ie, cerebral, spinal, mesenteric, renal, or lower extremity vascular beds). Renal malperfusion was suspected in 88 patients secondary to worsening hypertension (n = 34), evolving renal insufficiency (n = 37), computed tomography evidence of impaired renal blood flow (n = 13), or a combination of factors (n = 4). Patients underwent angiographic and intravascular ultrasound studies. Renal malperfusion was confirmed with a systolic gradient between the aortic root and renal hilum (average, 44 mm Hg). Results: Right renal arteries arose exclusively from the true lumen in 115 patients (70%), the false lumen in 11 (7%), and both lumens in 37 (23%). Left renal arteries arose exclusively from the true lumen in 69 patients (42%), the false lumen in 32 (20%), and both lumens in 62 (38%). Angiographic confirmation of malperfusion existed in 59 patients (67%) of the 88 suspected of such, and in 31 patients (39%) of the 79 with suspected malperfusion of nonrenal tissues. Of the 90 patients with confirmed renal malperfusion, 71 underwent endovascular therapy, including isolated renal artery stenting (n = 31), as well as proximal aortic fenestration with or without aortic stenting (n = 24), or both renal and aortic intervention (n = 16). Residual pressure gradients averaged 8.1 mm Hg after these interventions. Five procedure-related complications (7%) occurred. The periprocedural postintervention mortality rate was 21% (n = 15), including multisystem organ failure (n = 7), false lumen rupture (n = 3), reperfusion injury (n = 2), cerebral ischemia (n = 1), cardiac arrest (n = 1), and unknown (n = 1). Conclusions: Percutaneous aortic fenestration and renal artery stenting are both technically feasible and associated with an acceptable complication rate. Most patients respond well symptomatically, obviating the need for immediate surgical relief of renal artery obstruction and allowing for renal malperfusion recovery.
Reinforcement contingencies defined by the response deprivation hypothesis were evaluated in two multiple-response contexts. In one context a high probability response was freely available, and in ...the other context a low probability response was freely available. In the presence of the low probability, freely available response, a consistent reinforcement effect was evident for all 3 moderately mentally retarded participants; however, in the presence of the high probability response, the reinforcement effect was attenuated. Results were qualitatively consistent with several recent mathematical descriptions of behavior emphasizing the importance of the context in which reinforcement contingencies are introduced.
Blood vessels provide supportive microenvironments for maintaining tissue functions. Age-associated vascular changes and their relation to tissue aging and pathology are poorly understood. Here, we ...perform 3D imaging of young and aging vascular beds. Multiple organs in mice and humans demonstrate an age-dependent decline in vessel density and pericyte numbers, while highly remodeling tissues such as skin preserve the vasculature. Vascular attrition precedes the appearance of cellular hallmarks of aging such as senescence. Endothelial VEGFR2 loss-of-function mice demonstrate that vascular perturbations are sufficient to stimulate cellular changes coupled with aging. Age-associated tissue-specific molecular changes in the endothelium drive vascular loss and dictate pericyte to fibroblast differentiation. Lineage tracing of perivascular cells with inducible PDGFRβ and NG2 Cre mouse lines demonstrated that increased pericyte to fibroblast differentiation distinguishes injury-induced organ fibrosis and zymosan-induced arthritis. To spur further discoveries, we provide a freely available resource with 3D vascular and tissue maps.
A minimum number of index procedures is required for graduation. Without thresholds for surgical technique, it is unclear if robotic and open learning is balanced. We assessed the distribution of ...robotic and open surgeries performed by residents upon graduation.
Voluntary Accreditation Council for Graduate Medical Education resident case logs from 11 institutions were de-identified and trends in robotic and open major surgeries were compared using Wilcoxon rank sum and 2-sample t-tests.
A total of 89,199 major cases were recorded by 209 graduates from 2011 to 2017. The median proportion of robotic cases increased from 2011 to 2017 in reconstruction (4.7% to 15.2%), oncology (27.5% to 54.2%) and pediatrics (0% to 10.9%) (all values p <0.001). Robotic and open cases remained most divergent in reconstruction, with a median of 12 robotic (IQR 9-19) to 70 open cases (IQR 55-106) being performed by residents in 2017. Similar observations occurred in pediatrics. In oncology the number of robotic procedures superseded that of open in 2016 and rose to a median of 148 robotic (IQR 108-214) to 121 open cases (IQR 90-169) in 2017, with the driver being robotic prostatectomy. Substantial differences in surgical technique were observed between institutions and among graduates from the same institution.
Although robotic volume is increasing, the balance of surgical technique and the pace of change differ in reconstruction, oncology and pediatrics, as well as among individual institutions and graduates themselves. This raises questions about whether more specific guidelines are needed to ensure equity and standardization in training.
A strong motivation for undertaking psychiatric gene discovery studies is to provide novel insights into unknown biology. Although attention-deficit hyperactivity disorder (ADHD) is highly heritable, ...and large, rare copy number variants (CNVs) contribute to risk, little is known about its pathogenesis and it remains commonly misunderstood. We assembled and pooled five ADHD and control CNV data sets from the United Kingdom, Ireland, United States of America, Northern Europe and Canada. Our aim was to test for enrichment of neurodevelopmental gene sets, implicated by recent exome-sequencing studies of (a) schizophrenia and (b) autism as a means of testing the hypothesis that common pathogenic mechanisms underlie ADHD and these other neurodevelopmental disorders. We also undertook hypothesis-free testing of all biological pathways. We observed significant enrichment of individual genes previously found to harbour schizophrenia de novo non-synonymous single-nucleotide variants (SNVs; P=5.4 × 10(-4)) and targets of the Fragile X mental retardation protein (P=0.0018). No enrichment was observed for activity-regulated cytoskeleton-associated protein (P=0.23) or N-methyl-D-aspartate receptor (P=0.74) post-synaptic signalling gene sets previously implicated in schizophrenia. Enrichment of ADHD CNV hits for genes impacted by autism de novo SNVs (P=0.019 for non-synonymous SNV genes) did not survive Bonferroni correction. Hypothesis-free testing yielded several highly significantly enriched biological pathways, including ion channel pathways. Enrichment findings were robust to multiple testing corrections and to sensitivity analyses that excluded the most significant sample. The findings reveal that CNVs in ADHD converge on biologically meaningful gene clusters, including ones now established as conferring risk of other neurodevelopmental disorders.
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