Uncertainties of size measurements in electron microscopy characterization of nanomaterials in foods

Electron microscopy is a recognized standard tool for nanomaterial characterization, and recommended by the European Food Safety Authority for the size measurement of nanomaterials in food. Despite this, little data have been published assessing the reliability of the method, especially for size measurement of nanomaterials characterized by a broad size distribution and/or added to food matrices. This study is a thorough investigation of the measurement uncertainty when applying electron microscopy for size measurement of engineered nanomaterials in foods. Our results show that the number of measured particles was only a minor source of measurement uncertainty for nanomaterials in food, compared to the combined influence of sampling, sample preparation prior to imaging and the image analysis. The main conclusion is that to improve the measurement reliability, care should be taken to consider replications and matrix removal prior to sample preparation

Radioautographic Evidence of 3H-Tryptophan Incorporation in Secretory Cells of Rat Submandibular Glands

Tritiated tryptophan was injected intravenously into male rats, and the submandibular glands were removed at time intervals up to three hours after injection. Grain counts were made on light and electron microscope radioautographs to determine the effects on the amino acid.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67201/2/10.1177_00220345710500064601.pd

Relationships among musical aptitude, digit ratio and testosterone in men and women

Circulating adult testosterone levels, digit ratio (length of the second finger relative to the fourth finger), and directional asymmetry in digit ratio are considered sexually dimorphic traits in humans. These have been related to spatial abilities in men and women, and because similar brain structures appear to be involved in both spatial and musical abilities, neuroendocrine function may be related to musical as well as spatial cognition. To evaluate relationships among testosterone and musical ability in men and women, saliva samples were collected, testosterone concentrations assessed, and digit ratios calculated using standardized protocols in a sample of university students (N = 61), including both music and non-music majors. Results of Spearman correlations suggest that digit ratio and testosterone levels are statistically related to musical aptitude and performance only within the female sample: A) those females with greater self-reported history of exposure to music (p = 0.016) and instrument proficiency (p = 0.040) scored higher on the Advanced Measures of Music Audiation test, B) those females with higher left hand digit ratio (and perhaps lower fetal testosterone levels) were more highly ranked (p = 0.007) in the orchestra, C) female music students exhibited a trend (p = 0.082) towards higher testosterone levels compared to female non-music students, and D) female music students with higher rank in the orchestra/band had higher testosterone levels (p = 0.003) than lower ranked students. None of these relationships were significant in the male sample, although a lack of statistical power may be one cause. The effects of testosterone are likely a small part of a poorly understood system of biological and environmental stimuli that contribute to musical aptitude. Hormones may play some role in modulating the phenotype of musical ability, and this may be the case for females more so than males

Biotoxic effects of the herbicides on growth, seed yield, and grain protein of greengram

We studied the effects of atrazine, isoproturon, metribuzin and sulfosulfuron on plant vigour, nodulation, chlorophyll content, seed yield and protein content in seeds, in greengram inoculated with Bradyrhizobium sp. (vigna). The pre-emergence application of the four herbicides at 400 µg kg-1 of soil adversely affected the measured parameters. The average maximum increase of 10 % in seed yield occurred at 200 µg kg-1 of sulfosulfuron, while atrazine at 200 and 400 µg kg-1 of soil decreased the seed yield by 25 % and 40%, respectively. The average maximum chlorophyll content of 1.2 mg g-1 was obtained at 200 µg kg-1 of sulfosulfuron which declined consistently for all herbicides and increasing dose rates. Sulfosulfuron at 200 µg kg-1 increased the number of nodules found per plant by 7 % at 45 days after seeding the greengram. In contrast, the tested dose rates of atrazine, isoproturon and metribuzin significantly reduced the nodulation (nodule number and dry mass). The average maximum grain protein of 182 mg g-1 was obtained for sulfosulfuron at 400 µg kg-1, while minimum grain protein was obtained at 400 µg kg-1- of isoproturon (124 mg g-1) and atrazine (125 mg g-1) application. Among the herbicides tested, atrazine and metribuzin showed a large degree of phytotoxicity to the crop, inhibiting its vegetative growth and was thus incompatible with greengram. Journal of Applied Sciences and Environmental Management Vol. 10(3) 2006: 141-14

The effect of post-meal walking on 24-hour central blood pressure in young women with and without excess adiposity

Post-meal walking (PMW) performed after breakfast, lunch, and dinner has been demonstrated to reduce blood glucose. However, no studies have examined the potential additive benefits of post-meal walking exercise on daytime central blood pressure (BP) in young women. METHODS: Thirteen physically inactive, non-hypertensive women (Age: 20±1 years; percent body fat: 28.2±13%) completed the study during the early follicular or placebo phase of their contraceptive cycle. Participants completed a control day (CON; no exercise/excess physical activity) and PMW day (3 bouts x 15 minutes of brisk walking) over five days in random order. Daytime ambulatory BP and accelerometry data (to estimate METs) were measured and compared. RESULTS: PMW increased metabolic expenditure (PMW= 35.8±1.44 vs. CON= 33.7±0.94 METs, p0.05 for all). CONCLUSION: PMW does not lead to reductions in central BP in young, physically inactive women

A bibliometric study of the top 100 most-cited randomized controlled trials, systematic reviews and meta-analyses published in endodontic journals

Aim To identify and analyse the main features of the top 100 most‐cited randomized controlled trials, systematic reviews and meta‐analyses published in endodontic journals from 1961 to 2018. Methodology The Clarivate Analytics’ Web of Science ‘All Databases’ was used to search and analyse the 100 most frequently cited randomized controlled trials, systematic reviews and meta‐analyses having ‘randomized’, ‘randomised’, ‘randomized controlled’, ‘randomised controlled’, ‘randomized controlled trial’, ‘randomized controlled trials’, ‘clinical trial’, ‘systematic’, ‘systematic review’, ‘meta‐analysis’, and ‘meta‐analyses’ in the title section. The ‘International Endodontic Journal’, ‘Journal of Endodontics’, ‘Oral Surgery Oral Medicine Oral Pathology Oral Radiology and Endodontology’, ‘Australian Endodontic Journal’, ‘Endodontics & Dental Traumatology’, ‘Endo‐Endodontic Practice Today’ and ‘European Endodontic Journal’ were included in the publication name section. After ranking the articles in a descending order based on their citation counts, each article was cross‐matched with the citation counts in Elsevier's Scopus and Google Scholar. The articles were analysed, and information on citation counts, citation density, year of publication, contributing authors, institutions and countries, journal of publication, study design, topic of the article and keywords was extracted. Results The citation counts of the 100 most‐cited articles varied from 235 to 20 (Web of Science), 276 to 17 (Scopus) and 696 to 1 (Google Scholar). The year in which the top 100 articles were published was 2010 (n = 13). Among 373 authors, the greatest number of articles was associated with three individuals namely Reader A (n = 5), Beck M (n = 5) and Kvist T (n = 5). Most of the articles originated from the United States (n = 24) with the greatest contribution from Ohio State University (USA) (n = 5). Randomized controlled trials were the most frequent study design (n = 45) followed by systematic reviews (n = 30) with outcome studies of root canal treatment being the major topic (n = 35). The Journal of Endodontics published the largest number of included articles (n = 70) followed by the International Endodontic Journal (n = 27). Among 259 unique keywords, meta‐analysis (n = 23) and systematic review (n = 23) were the most frequently used. Conclusion This study has revealed that year of publication had no obvious impact on citation count. The bibliometric analysis highlighted the quantity and quality of research, and the evolution of scientific advancements made in the field of Endodontology over time. Articles before 1996, that is prior to the CONSORT statement that encouraged authors to include specific terms in the title and keywords, may not have been included in this electronic search

Decoherence control: Universal protection of two-qubit states and two-qubit gates using continuous driving fields

A field configuration utilizing local static and oscillating fields is constructed to achieve universal (but low-order) protection of two-qubit states. That is, two-qubit states can be protected against arbitrary system-environment coupling if the driving field frequency, as compared with the cutoff frequency of the environment, is sufficiently large. Equally important, we show that it is possible to construct driving fields to protect two-qubit entangling gates against decoherence, without assuming any particular form of system-environment coupling. Using a non-Markovian master equation, we further demonstrate the effectiveness of our continuous dynamical decoupling fields in protecting entanglement and the excellent performance of protected two-qubit gates in generating entanglement. The results are complementary to current studies of entanglement protection using universal dynamical decoupling pulse sequences.Comment: 16 pages, 6 figures (improved introduction, made connections with early studies of dynamically corrected quantum gates