Current research in meat color Mancini, R.A.; Hunt, M.C.
Meat science,
09/2005, Letnik:
71, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
This review surveyed recent literature focused on factors that affect myoglobin chemistry, meat color, pigment redox stability, and methodology used to evaluate these properties. The appearance of ...meat and meat products is a complex topic involving animal genetics, ante- and postmortem conditions, fundamental muscle chemistry, and many factors related to meat processing, packaging, distribution, storage, display, and final preparation for consumption. These factors vary globally, but the variables that affect basic pigment chemistry are reasonably consistent between countries. Essential for maximizing meat color life is an understanding of the combined effects of two fundamental muscle traits, oxygen consumption and metmyoglobin reduction. In the antemortem sector of research, meat color is being related to genomic quantitative loci, numerous pre-harvest nutritional regimens, and housing and harvest environment. Our knowledge of postmortem chilling and pH effects, atmospheres used for packaging, antimicrobial interventions, and quality and safety of cooked color are now more clearly defined. The etiology of bone discoloration is now available. New color measurement methodology, especially digital imaging techniques, and improved modifications to existing methodology are now available. Nevertheless, unanswered questions regarding meat color remain. Meat scientists should continue to develop novel ways of improving muscle color and color stability while also focusing on the basic principles of myoglobin chemistry.
To assess the effects of aging time (0, 15, 30, and 45 d) and temperature (0 or 5°C) on beef mitochondria and steak color, vacuum packaged longissimus (n=15) and cardiac muscles were assigned to 1 of ...6 temperature×time combinations. As time increased, initial red color intensity increased whereas both mitochondrial oxygen consumption and color stability decreased. The decrease in mitochondrial oxygen consumption associated with longer aging times will increase initial color intensity. However, this improvement in color development will be negated by the decreased color stability that results from the effects of storage on mitochondria.
•Decreased mitochondrial function during aging influences beef color.•Decreased mitochondrial oxygen consumption will increase initial color intensity.•The negative effects of aging on mitochondria will decrease beef color stability.
Nearly a century ago it was recognized that radiation absorption by stellar matter controls the internal temperature profiles within stars. Laboratory opacity measurements, however, have never been ...performed at stellar interior conditions, introducing uncertainties in stellar models. A particular problem arose when refined photosphere spectral analysis led to reductions of 30-50 per cent in the inferred amounts of carbon, nitrogen and oxygen in the Sun. Standard solar models using the revised element abundances disagree with helioseismic observations that determine the internal solar structure using acoustic oscillations. This could be resolved if the true mean opacity for the solar interior matter were roughly 15 per cent higher than predicted, because increased opacity compensates for the decreased element abundances. Iron accounts for a quarter of the total opacity at the solar radiation/convection zone boundary. Here we report measurements of wavelength-resolved iron opacity at electron temperatures of 1.9-2.3 million kelvin and electron densities of (0.7-4.0) × 10(22) per cubic centimetre, conditions very similar to those in the solar region that affects the discrepancy the most: the radiation/convection zone boundary. The measured wavelength-dependent opacity is 30-400 per cent higher than predicted. This represents roughly half the change in the mean opacity needed to resolve the solar discrepancy, even though iron is only one of many elements that contribute to opacity.
The first systematic study of opacity dependence on atomic number at stellar interior temperatures is used to evaluate discrepancies between measured and modeled iron opacity J. E. Bailey et al., ...Nature (London) 517, 56 (2015)NATUAS0028-083610.1038/nature14048. High-temperature (>180 eV) chromium and nickel opacities are measured with ±6%-10% uncertainty, using the same methods employed in the previous iron experiments. The 10%-20% experiment reproducibility demonstrates experiment reliability. The overall model-data disagreements are smaller than for iron. However, the systematic study reveals shortcomings in models for density effects, excited states, and open L-shell configurations. The 30%-45% underestimate in the modeled quasicontinuum opacity at short wavelengths was observed only from iron and only at temperature above 180 eV. Thus, either opacity theories are missing physics that has nonmonotonic dependence on the number of bound electrons or there is an experimental flaw unique to the iron measurement at temperatures above 180 eV.
The interpretation of x-ray spectra emerging from x-ray binaries and active galactic nuclei accreted plasmas relies on complex physical models for radiation generation and transport in photoionized ...plasmas. These models have not been sufficiently experimentally validated. We have developed a highly reproducible benchmark experiment to study spectrum formation from a photoionized silicon plasma in a regime comparable to astrophysical plasmas. Ionization predictions are higher than inferred from measured absorption spectra. Self-emission measured at adjustable column densities tests radiation transport effects, demonstrating that the resonant Auger destruction assumption used to interpret black hole accretion spectra is inaccurate.
The actual SARS-CoV-2 outbreak caused a highly transmissible disease with a tremendous impact on elderly people. So far, few studies focused on very elderly patients (over 80 years old). In this ...study we examined the clinical presentation and the outcome of the disease in this group of patients, admitted to our Hospital in Rome.
This is a single-center, retrospective study performed in the Sant'Andrea University Hospital of Rome. We included patients older than 65 years of age with a diagnosis of COVID-19, from March 2020 to May 2020, divided in two groups according to their age (Elderly: 65-80 years old; Very Elderly > 80 years old). Data extracted from the each patient record included age, sex, comorbidities, symptoms at onset, the Pneumonia Severity Index (PSI), the ratio of the partial pressure of oxygen in arterial blood (PaO2) to the inspired oxygen fraction (FiO2) (P/F) on admission, laboratory tests, radiological findings on computer tomography (CT), length of hospital stay (LOS), mortality rate and the viral shedding. The differences between the two groups were analyzed by the Fisher's exact test or the Wilcoxon signed-rank test for categorical variables and the Mann-Whitney U test for continuous variables. To assess significance among multiple groups of factors, we used the Bonferroni correction. The survival time was estimated by Kaplan-Meier method and Log Rank Test. Univariate and Multivariate logistic regression were performed to estimate associations between age, comorbidities, provenance from long-stay residential care homes (LSRCH) s and clinical outcomes.
We found that Very Elderly patients had an increased mortality rate, also due to the frequent occurrence of multiple comorbidities. Moreover, we found that patients coming from LSRCHs appeared to be highly susceptible and vulnerable to develop severe manifestations of the disease.
We demonstrate that there were considerable differences between Elderly and Very Elderly patients in terms of inflammatory activity, severity of disease, adverse clinical outcomes. To establish a correct risk stratification, comorbidities and information about provenience from LSRCHs should be considered.
The purpose of this project was to survey radiation oncology chief residents to define their residency experience and readiness for independent practice.
During the academic years 2013 to 2014 and ...2014 to 2015, the Association of Residents in Radiation Oncology (ARRO) conducted an electronic survey of post-graduate year-5 radiation oncology residents in the United States during the final 3 months of training. Descriptive statistics are reported.
Sixty-six chief residents completed the survey in 2013 to 2014 (53% response rate), and 69 completed the survey in 2014 to 2015 (64% response rate). Forty to 85% percent of residents reported inadequate exposure to high-dose rate and low-dose rate brachytherapy. Nearly all residents in both years (>90%) reported adequate clinical experience for the following disease sites: breast, central nervous system, gastrointestinal, genitourinary, head and neck, and lung. However, as few as 56% reported adequate experience in lymphoma or pediatric malignancies. More than 90% of residents had participated in retrospective research projects, with 20% conducting resident-led prospective clinical trials and 50% conducting basic science or translational projects. Most chief residents reported working 60 or fewer hours per week in the clinical/hospital setting and performing fewer than 15 hours per week tasks that were considered to have little or no educational value. There was more than 80% compliance with Accreditation Council for Graduate Medical Education (ACGME) work hour limits. Fifty-five percent of graduating residents intended to join an established private practice group, compared to 25% who headed for academia. Residents perceive the job market to be more competitive than previous years.
This first update of the ARRO chief resident survey since the 2007 to 2008 academic year documents US radiation oncology residents' experiences and conditions over a 2-year period. This analysis may serve as a valuable tool for those seeking to improve training of the next generation of oncology leaders.
He β spectral line shapes are important for diagnosing temperature and density in many dense plasmas. This work presents He β line shapes measured with high spectral resolution from solid-density ...plasmas with minimized gradients. The line shapes show hallmark features of Stark broadening, including quantifiable redshifts and double-peaked structure with a significant dip between the peaks; these features are compared to models through a Markov chain Monte Carlo framework. Line shape theory using the dipole approximation can fit the width and peak separation of measured line shapes, but it cannot resolve an ambiguity between electron density ne and ion temperature Ti, since both parameters influence the strength of quasistatic ion microfields. Here a line shape model employing a full Coulomb interaction for the electron broadening computes self-consistent line widths and redshifts through the monopole term; redshifts have different dependence on plasma parameters and thus resolve the ne − Ti ambiguity. The measured line shapes indicate densities that are 80–100% of solid, identifying a regime of highly ionized but well-tamped plasma. This analysis also provides the first strong evidence that dense ions and electrons are not in thermal equilibrium, despite equilibration times much shorter than the duration of x-ray emission; cooler ions may arise from nonclassical thermalization rates or anomalous energy transport. The experimental platform and diagnostic technique constitute a promising new approach for studying ion-electron equilibration in dense plasmas.
Purpose
This series was aimed to analyze feasibility, safety and postoperative quality of life of trans-abdominal pre-peritoneal repair in incarcerated hernia; the rationale was a safe hernia ...reduction, more accurate abdomen exploration, diagnosis and treatment of contralateral unknown hernia.
Methods
With a minimum follow-up of 30 months, 20 urgent incarcerated inguinal hernia patients were submitted to TAPP. Signs of strangulation, peritonitis and major comorbidity were exclusion criteria. Feasibility and safety were evaluated by ability to hernia reduction, conversion rate, operative time, perioperative mortality, morbidity, hospital stay, prosthesis infection and recurrence. Finally, quality of life was assessed by acute and chronic pain score, recovery of normal activities, return to work and patients’ satisfaction survey.
Results
Under vision sac reduction was always achieved, incision of internal ring during the reduction manoeuvre was necessary in 40% of pts, intraoperative complications, conversions or perioperative mortality were not observed. In one case (5%) partial omentectomy was necessary. Contralateral hernia was diagnosed and repaired in 20%. Median operative time was 81.3 min, postoperative minor complications were recorded in 5 patients (25%), median in hospital stay was 2 days. After a median follow-up of 39 months, 1 patient recurred (5%). Acute pain, was scored 3 as median value (range 1–5), only one patient scored 2 as chronic pain during follow-up.
Conclusions
Laparoscopic approach for incarcerated inguinal hernia repair is not the standard treatment. In our experience, with the limit of a single-surgeon series, selected patients showed satisfactory results in terms of feasibility, safety, postoperative quality of life and patients’ satisfaction were observed. Few series about this topic were published. More prospective trials are needed.
Stereotactic body radiotherapy (SBRT) has been increasingly utilized for medically inoperable early stage non–small-cell lung cancer. However, a lower biological equivalent dose (BED) is often used ...for central tumors given toxicity concerns, potentially leading to decreased local control (LC). We compared survival, LC, and toxicity outcomes for SBRT patients with centrally versus peripherally located tumors.
We included patients with primary cT1-2N0M0 non–small-cell lung cancer treated with SBRT at our institution from September 2007 to August 2013 with follow-up through August 2014. Central tumor location was defined as within 2 cm of the proximal bronchial tree, heart, great vessels, trachea, or other mediastinal structures. Kaplan–Meier analysis and multivariable Cox regression modeling were used for overall survival (OS) and LC, and the χ2 test and multivariable logistic regression modeling were used for toxicity.
We included 251 patients (111 central, 140 peripheral) with median follow-up of 31.2 months. Patients with central tumors were more likely to be older (mean 75.8 versus 73.5 years; p = 0.04), have larger tumors (mean 2.5 cm versus 1.9 cm; p < 0.001), and be treated with a lower BED (mean 120.2 Gy versus 143.5 Gy; p < 0.001). Multivariable analysis revealed that tumor location was not associated with worse OS, LC, or toxicity. Patients with central tumors were less likely to have acute grade greater than or equal to three toxicity than those with peripheral tumors (odds ratio: 0.24; p = 0.02).
Central tumor location did not predict for inferior OS, LC, or toxicity following SBRT when a lower mean BED was utilized.
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