Gold Nanoparticle Characterization: Improved Methods for Measuring Nanoparticle Surface Properties and Colloidal Stability

Plasmonic nanoparticles are used in a wide variety of applications over a broad array of fields including medicine, energy, and environmental chemistry. The continued successful development of this class of materials requires the accurate characterization of nanoparticle stability for a variety of solution-based conditions. Although a wide array of methods exist, there is an absence of a unified, quantitative means for complete nanoparticle characterization. This work focuses on the challenges inherent with current methods through a comparative analysis of the current gold standard characterization methods. I propose using capillary electrophoresis and micro-capillary electrophoresis as powerful tools for better quantifying the inherent polydispersity and differences in surface functionalization within a nanoparticle sample. I present the Particle Instability Parameter (PIP) as a robust, quantitative, and generalizable characterization technique based upon UV-Vis absorbance spectroscopy to characterize colloidal instability. I validate PIP performance with both traditional and alternative characterization methods by measuring gold nanorod instability in response to different salt (NaCl) concentrations and as a function of solution pH, salt, and buffer type. I contextualize these methods within the literature on gold nanoparticle characterization to establish a standardized methodology for nanoparticle analysis. Finally, I present a concept for an integrated biodiagnostics platform using gold nanorods based upon an integrated microfluidic microspectrophotometry system for the detection of pathogens

Marital satisfaction and Cherokee language fluency.

The Marital Satisfaction Inventory-Revised norms were compared with scores for 162 volunteer Cherokee participants. In addition, aspects of marital satisfaction were examined for participants classified as fluent or non-fluent in the Cherokee language. Data was collected through a demographic form and the Marital Satisfaction Inventory-Revised. Differences occurred on four of the thirteen scales on the MSI-R norms for the Cherokee participants. Differences were also found on the main effect of fluency on two scales. Differences were also detected on two interaction factors on personal fluency and spousal fluency

Relative Hypoglycemia in Diabetic Patients With Critical Illness

Objectives: Relative hypoglycemia is a decrease in glucose greater than or equal to 30% below prehospital admission levels (estimated by hemoglobin A1C) but not to absolute hypoglycemia levels. It is a recognized pathophysiologic phenomenon in ambulant poorly controlled diabetic patients but remains unexamined during critical illness. We examined the frequency, characteristics, and outcome associations of relative hypoglycemia in diabetic patients with critical illness. Design: Retrospective cohort study. Setting: ICU of a tertiary hospital. Patients: One-thousand five-hundred ninety-two critically ill diabetic patients between January 2013 and December 2017. Interventions: None. Measurements and Main Results: The median age of patients was 67 years (interquartile range, 60-75 yr). The median Acute Physiology and Chronic Health Evaluation III score was 53 (interquartile range, 40-68). Thirty-four percent of patients with diabetes experienced relative hypoglycemia (exposure) during their ICU admission. Such patients had higher glycemic lability, hemoglobin A1C levels, and Acute Physiology and Chronic Health Evaluation III scores. The hazard ratio for 28-day mortality of diabetic patients, censored at hospital discharge, for patients with relative hypoglycemia was 1.9 (95% CI, 1.3-2.8) and was essentially unchanged after adjustment for episodes of absolute hypoglycemia. After an episode of relative hypoglycemia, the hazard ratio for subsequent absolute hypoglycemia in the ICU was 3.5 (95% CI, 2.3-5.3). Conclusions: In ICU patients with diabetes, relative hypoglycemia is common, increases with higher hemoglobin A1C levels, and is a modifiable risk factor for both mortality and subsequent absolute hypoglycemia. These findings provide the rationale for future interventional studies to explore new blood glucose management strategies and to substantiate the clinical relevance of relative hypoglycemia

Does the addition of cone-beam CT to panoral imaging reduce inferior dental nerve injuries resulting from third molar surgery? A systematic review.

This systematic review aims to examine whether cone-beam CT (CBCT) assessment influences the incidence of nerve injury following high-risk mandibular third molar (MTM) surgery. Randomised controlled trials comparing two and three-dimensional imaging for assessing high-risk MTMs were included. MEDLINE, EMBASE, CENTRAL and the Dentistry and Oral Science Source (DOSS) were systematically searched along with extensive grey literature searches, hand searching of web sites, and detailed citation searching up to 3 September 2022. Risk of bias was assessed against the Cochrane Risk of Bias Tool (RoB 2.0). Certainty of the evidence was assessed using GRADE. Two authors independently screened 402 abstracts prior to full text screening of 27 articles, which culminated in seven RCTs for inclusion. Two studies were assessed as high risk of bias overall. The other five raised some concerns largely due to unblinded patients and lack of prior trial registration. Just one study reported significantly less nerve injuries following CBCT. The remaining six articles found no significant difference. The seven RCTs included in this systematic review offered moderate quality evidence that CBCT does not routinely translate to reduced incidence of nerve injury in MTM removal. A single study provided low quality evidence for a consequent change in the surgical approach. Low quality evidence from 3 studies suggested CBCT does not influence the duration of third molar surgery.This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Open access funding was provided by the Qatar National Library

A non-destructive method for estimating onion leaf area

peer-reviewedWe would like to thank to the CICYT for funding the national project (AGL2007-66716-CO3-03), and the Education Regional Government of C-LM for funding the project (PCI08-0117).Leaf area is one of the most important parameters for characterizing crop growth and development, and its measurement is useful for examining the effects of agronomic management on crop production. It is related to interception of radiation, photosynthesis, biomass accumulation, transpiration and gas exchange in crop canopies. Several direct and indirect methods have been developed for determining leaf area. The aim of this study is to develop an indirect method, based on the use of a mathematical model, to compute leaf area in an onion crop using non-destructive measurements with the condition that the model must be practical and useful as a Decision Support System tool to improve crop management. A field experiment was conducted in a 4.75 ha commercial onion plot irrigated with a centre pivot system in Aguas Nuevas (Albacete, Spain), during the 2010 irrigation season. To determine onion crop leaf area in the laboratory, the crop was sampled on four occasions between 15 June and 15 September. At each sampling event, eight experimental plots of 1 m2 were used and the leaf area for individual leaves was computed using two indirect methods, one based on the use of an automated infrared imaging system, LI-COR-3100C, and the other using a digital scanner EPSON GT-8000, obtaining several images that were processed using Image J v 1.43 software. A total of 1146 leaves were used. Before measuring the leaf area, 25 parameters related to leaf length and width were determined for each leaf. The combined application of principal components analysis and cluster analysis for grouping leaf parameters was used to reduce the number of variables from 25 to 12. The parameter derived from the product of the total leaf length (L) and the leaf diameter at a distance of 25% of the total leaf length (A25) gave the best results for estimating leaf area using a simple linear regression model. The model obtained was useful for computing leaf area using a non-destructive method.CICYTEducation Regional Government of C-L

Impact of ocean acidification on the intestinal microbiota of the marine sea bream (Sparus aurata L.)

Within a scenario of increasing atmospheric CO2 and ocean acidification (OA), it is highly relevant to investigate its impacts not only on fish performance but also on fish intestinal microbiome and how that reflects on host performance and health. The main objective of this study was to establish if the intestinal microbiota of the sea bream (Sparus aurata) was affected by high level of CO2 in line with the predictions for this century. The bacterial communities of the intestinal fluid were characterized in animals kept at the present-day level of CO2 (400 μatm) and in animals switched to high CO2 (1200 μatm) for 1 month. Bacterial taxa identification was based on molecular methods, using the DNA coding for the 16S ribosomal RNA and primers targeting the regions V1-V3. Amplicons obtained from DNA samples of animals in the same tank were combined, cloned to obtain a bacterial DNA library, and the clones were sequenced. No significant differences were found between the two treatments for alpha diversity. However, beta diversity analysis revealed distinct dysbiosis in response to hypercapnia, with phylum Firmicutes absent from the bacterial communities of fish exposed to 1200 μatm CO2, whereas Proteobacteria relative abundance was increased at elevated CO2, due to the presence of Gammaproteobacteria (Vibrionaceae and Alteromonadaceae), a class not present in the control samples. This study provides a first glimpse at the impact of OA in fish intestinal microbiota and highlights potential downstream effects to the general condition of fishes under hypercapnia.Funding Agency Portuguese Foundation for Science and Technology PTDC/MAR-BIO/3034/2014 Portuguese Foundation for Science and Technology UID/Multi/04326/2019 Ministry of Science and Higher Education, Polandinfo:eu-repo/semantics/publishedVersio

Cortical thickness, surface area and volume measures in Parkinson's disease, multiple system atrophy and progressive supranuclear palsy

OBJECTIVE Parkinson's disease (PD), Multiple System Atrophy (MSA) and Progressive Supranuclear Palsy (PSP) are neurodegenerative diseases that can be difficult to distinguish clinically. The objective of the current study was to use surface-based analysis techniques to assess cortical thickness, surface area and grey matter volume to identify unique morphological patterns of cortical atrophy in PD, MSA and PSP and to relate these patterns of change to disease duration and clinical features. METHODS High resolution 3D T1-weighted MRI volumes were acquired from 14 PD patients, 18 MSA, 14 PSP and 19 healthy control participants. Cortical thickness, surface area and volume analyses were carried out using the automated surface-based analysis package FreeSurfer (version 5.1.0). Measures of disease severity and duration were assessed for correlation with cortical morphometric changes in each clinical group. RESULTS Results show that in PSP, widespread cortical thinning and volume loss occurs within the frontal lobe, particularly the superior frontal gyrus. In addition, PSP patients also displayed increased surface area in the pericalcarine. In comparison, PD and MSA did not display significant changes in cortical morphology. CONCLUSION These results demonstrate that patients with clinically established PSP exhibit distinct patterns of cortical atrophy, particularly affecting the frontal lobe. These results could be used in the future to develop a useful clinical application of MRI to distinguish PSP patients from PD and MSA patients

Dissociating Inhibition, Attention, and Response Control in the Frontoparietal Network Using Functional Magnetic Resonance Imaging

Evidence suggests that the right inferior frontal cortex (IFC) plays a specialized role in response inhibition. However, more recent findings indicate a broader role for this region in attentional control. Here, we used functional magnetic resonance imaging to examine the functional role of the right IFC in attention, inhibition, and response control in 2 experiments that employed novel variations of the go/no-go task. Across the 2 experiments, we observed a graded response in the right insula/IFC, whereby increasing response control demands led to an increase in activation. The results are consistent with the hypothesis that this region plays a key role in the integration of bottom-up, sensory information with top-down, response-related information to facilitate flexible, goal-directed behavior