A Multi-scale Biophysical Approach to Develop Structure-Property Relationships in Oral Biofilms

Over the last 5-10 years, optical coherence tomography (OCT) and atomic force microscopy (AFM) have been individually applied to monitor the morphological and mechanical properties of various single-species biofilms respectively. This investigation looked to combine OCT and AFM as a multi-scale approach to understand the role sucrose concentration and age play in the morphological and mechanical properties of oral, microcosm biofilms, in-vitro. Biofilms with low (0.1% w/v) and high (5% w/v) sucrose concentrations were grown on hydroxyapatite (HAP) discs from pooled human saliva and incubated for 3 and 5 days. Distinct mesoscale features of biofilms such as regions of low and high extracellular polymeric substances (EPS) were identified through observations made by OCT. Mechanical analysis revealed increasing sucrose concentration decreased Young's modulus and increased cantilever adhesion (p < 0.0001), relative to the biofilm. Increasing age was found to decrease adhesion only (p < 0.0001). This was due to mechanical interactions between the indenter and the biofilm increasing as a function of increased EPS content, due to increasing sucrose. An expected decrease in EPS cantilever contact decreased adhesion due to bacteria proliferation with biofilm age. The application OCT and AFM revealed new structure-property relationships in oral biofilms, unattainable if the techniques were used independently

Adverse events in radiation oncology: A case series from wake up safe, the pediatric anesthesia quality improvement initiative

BackgroundRadiation therapy in pediatric patients often requires anesthesia and poses environmental challenges. Monitoring must be done remotely to limit radiation exposure to the provider. Airway access can be limited by masks or frames. Care is often delivered in relatively inaccessible locations in the hospital. While individual institutions have reported their outcomes, this case series aims to review a multicenter registry of significant adverse events and make recommendations for improved care.MethodsWake Up Safe: The Pediatric Quality Improvement Initiative maintains a multisite, voluntary registry of pediatric perianesthetic significant adverse events. This was queried for reports from radiation oncology from January 1, 2010 to May 10, 2018. The database contained 3,379 significant adverse events from approximately 3.3 million anesthetics. All 33 institutions submitted data on a standardized form to a central data repository (Axio Research, Seattle Washington). Prior to each significant adverse events case submission, three anesthesiologists who were not involved in the event analyzed the event using a standardized root cause analysis method to identify the causal or contributing factor(s).ResultsSix significant adverse events were identified. In three, incorrect programming of a propofol infusion resulted in overdose. In case one, the 3â yearâ old female became hypotensive, requiring vasopressors and volume resuscitation. In the second, the 2â yearâ old female experienced airway obstruction and apnea requiring chin lift. In case three, the child suffered no consequences despite a noted overdose of propofol infusion. In case four, a 2â yearâ old female with recent respiratory infection suffered laryngospasm during an unmonitored transport to the recovery area. She developed profound oxygen desaturation with bradycardia treated with succinylcholine and chest compressions. In case five, a 6â yearâ old former premature child suffered laryngospasm at the conclusion of mask creation under general anesthesia with a laryngeal mask airway. The radiation mask delayed recognition of copious secretions. Finally, in case six, a 6â yearâ old undergoing stereotactic radiosurgery in a head halo suffered bronchospasm and unintended extubation during therapy which required multiple attempts at reintubation by multiple providers ultimately requiring cancellation of the treatment and transport to the intensive care unit.ConclusionThere were few radiation oncology significant adverse events, but analysis has led to the identification of several specific opportunities for improvement in pediatric anesthesia for radiation oncology.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148238/1/pan13567_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148238/2/pan13567.pd

Time and dose dependency of bone-sarcomas in patients injected with radium-224

The time course and dose dependency of the incidence of bone-sarcomas among 900 German patients treated with high doses of radium-224 is analysed in terms of a proportional hazards model with a log-normal dependency of time to tumor and a linear-quadratic dose relation. The deduced dose dependency agrees well with a previous analysis in terms of a non-parametric proportional hazards model, and confirms the temporal distribution which has been used in the Radioepidemiological Tables of NIH. However, the linear-quadratic dose-response model gives a risk estimate for low doses which is somewhat less than half that obtained under the assumption of linearity. Dedicated to Prof. W. Jacobi on the occasion of his 60th birthday Work performed under Euratom contracts BI6-D-083-D, BI6-F-111-D, U.S. Department of Energy contract DE-AC 02-76 EV-00119, the U.S. National Cancer Institut

Disruption of the autoinhibited state primes the E3 ligase parkin for activation and catalysis

The PARK2 gene is mutated in 50% of autosomal recessive juvenile parkinsonism (ARJP) cases. It encodes parkin, an E3 ubiquitin ligase of the RBR family. Parkin exists in an autoinhibited state that is activated by phosphorylation of its N‐terminal ubiquitin‐like (Ubl) domain and binding of phosphoubiquitin. We describe the 1.8 Å crystal structure of human parkin in its fully inhibited state and identify the key interfaces to maintain parkin inhibition. We identify the phosphoubiquitin‐binding interface, provide a model for the phosphoubiquitin–parkin complex and show how phosphorylation of the Ubl domain primes parkin for optimal phosphoubiquitin binding. Furthermore, we demonstrate that the addition of phosphoubiquitin leads to displacement of the Ubl domain through loss of structure, unveiling a ubiquitin‐binding site used by the E2~Ub conjugate, thus leading to active parkin. We find the role of the Ubl domain is to prevent parkin activity in the absence of the phosphorylation signals, and propose a model for parkin inhibition, optimization for phosphoubiquitin recruitment, release of inhibition by the Ubl domain and engagement with an E2~Ub conjugate. Taken together, this model provides a mechanistic framework for activating parkin

Remanent Magnetic Measurements on Perpendicular Recording Materials with Compensation for Demagnetizing Fields

Existing techniques for characterization of longitudinal recording media using remanence measurements are extended to perpendicular media, in particular to Alumite, and correction for demagnetizing fields is taken into account. It is found that these techniques have limited value because of the sensitivity of the analysis to the correction factor used. Measurement of the recoil lines is investigated as an alternative method of probing the reversal processes

Normalization factors for magnetic relaxation of small particle systems in non-zero magnetic field

We critically discuss relaxation experiments in magnetic systems that can be characterized in terms of an energy barrier distribution, showing that proper normalization of the relaxation data is needed whenever curves corresponding to different temperatures are to be compared. We show how these normalization factors can be obtained from experimental data by using the $T \ln(t/\tau_0)$ scaling method without making any assumptions about the nature of the energy barrier distribution. The validity of the procedure is tested using a ferrofluid of Fe_3O_4 particles.Comment: 5 pages, 6 eps figures added in April 22, to be published in Phys. Rev. B 55 (1 April 1997

Classification and characterisation of magmatic-hydrothermal tourmaline by combining field observations and microanalytical techniques

Tourmaline from the St. Byron lobe of the Land’s End granite, SW England, was assessed by macroscopic, optical and quantitative microanalytical methods. In total, seven types of tourmaline were distinguished. The seven types reflect different crystallisation environments and stages in the magmatic-hydrothermal transition. Types 1-3 are interpreted to represent a gradual transition from tourmaline crystallising from a silicate melt to precipitation from magmatic aqueous fluids. Types 5-7 crystallised at subsolidus conditions from a different fluid generation than types 1-3. These fluids may be magmatic or mixed with other fluids (e.g., meteoric or formation waters). The Sn-mineralisation in the area is mostly related to the latter fluid generation, and the mineralising potential is reflected by the tourmaline composition.This is an open access article, available to all readers online, published under a creative commons licensing Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Published under licence by IOP Publishing Lt

The utility of upper urinary tract urine cytology before and after application of the Paris system

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149260/1/dc24127_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149260/2/dc24127.pd

Predictors of multidomain decline in health‐related quality of life after stereotactic body radiation therapy (SBRT) for prostate cancer

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136687/1/cncr30519_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136687/2/cncr30519.pd