Abstract Fresh fruits and vegetables (F&V), with their attractive sensory, flavors, and nutrients, occupy a highly valuable part of people's daily diet. Plenty of postharvest studies have focused on the effects of preservation techniques on the edible quality and nutrients of F&V. Therefore, it is crucial to summarize the research methods of those quality and nutritional indicators for F&V. This work reviews the measurement and analysis methods on these parameters of postharvest F&V which have been validated by numerous publications, including firmness, sugars/acids, pigments, phenols, etc. Importantly, some instruments are involved in these experimental methods, such as firmness tester, spectrophotometer, gas chromatograph, and so on. Furthermore, some promising analysis methods in the past decades combined with advanced technologies are also raised in our discussion. This work is expected to provide guidance and normative significance for future research on quality assessment, preservation, and processing characteristics of F&V.
Abstract The effects of temperature and duration of storage on the toxicity of estuarine sediments were investigated with the Crassostrea gigas oyster embryo bioassay. Sediments ranging from unpolluted (controls) to extremely polluted with heavy metals (>100 ppm Hg, Cu, Zn, and Pb) and total hydrocarbons (>1,000 ppm) were collected from sites in southwest France and northern Spain. Control sediments were toxic only at the highest concentrations tested and after freezing in liquid nitrogen (−196°C). Polluted sediments significantly reduced the success of oyster embryogenesis. Analysis of variance showed that the effect of storage temperature on toxicity increased with the prolongation of storage. Prolonged storage of fresh (4°C) sediments resulted in a loss of toxicity, which was more rapid in the less-polluted sediments. Deep-frozen sediments (−196°C) were highly toxic regardless of origin and storage time, and because deep-freezing causes spurious toxicity in the control samples, it cannot be recommended for toxicological studies. In the context of the assessment of sediment toxicity by embryo–larval bioassays, fresh (4°C) storage is recommended when sediments need to be stored for no longer than a few days. The advisable duration of fresh storage to avoid false-negative results is directly related to the degree of toxicity. Should the sediments require prolonged storage, freezing at −20°C appears to be the best choice.
Abstract A method was developed for the determination of tiamulin (TML), 14-deoxy-14-[(2-diethylaminoethyl)- mercaptoacetoxy]mutilin hydrogen fumarate, a semisynthetic derivative of the naturally occurring antibiotic pleuromutilin produced by the fungus Pleurotus mutilis. This drug, with high activity against Gram-positive bacteria, some Gram-negative bacteria, and several strains of mycoplasms is administered to animals in food, drinking water, or by injection; however, its chemical structure causes problems in analysis of feeds. Although the molecule is charged below pH 8, at-tempts to analyze TML-containing extracts on ion-exchange columns or other polar stationary phases have failed. Additionally, TML shows no fluorescence activity and only poor UV activity. The present method consists of organic solvent extraction followed by liquid chromatography with UV detection. A low wavelength (208 nm) was used for detection. Limits of detection and quantitation, as well as data for recovery and repeatability obtained during characterization of the method, are described. The applicability of the optimized method was tested by analyzing commercial blank feeds processed after TML-medicated feeds.
New information has become available since the ISC, AAMCC, and SECAC released their first extensive guidedelines to improve the diagnosis and treatment of adult arterial hypertension. A critical assessment of evidence and a comparison of what international guidelines now propose are the basis for the following statements, which update the recommendations first issued in 2013. Office blood pressure (BP) measurements should no longer be considered to be the "gold standard" for the diagnosis of hypertension and assessment of cardiovascular risk. Relying on office BP, even when supplemented with at-home wake-time self-measurements, to identify high-risk individuals, disregarding circadian BP patterning and asleep BP level, leads to potential misclassification of 50% of all evaluated persons. Accordingly, ambulatory BP monitoring is the recommended reference standard for the diagnosis of true hypertension and accurate assessment of cardiovascular risk in all adults ≥18 yrs of age, regardless of whether office BP is normal or elevated. Asleep systolic BP mean is the most significant independent predictor of cardiovascular events. The sleep-time relative SBP decline adds prognostic value to the statistical model that already includes the asleep systolic BP mean and corrected for relevant confounding variables. Accordingly, the asleep systolic BP mean is the recommended protocol to diagnose hypertension, assess cardiovascular risk, and predict cardiovascular event-free interval. In men, and in the absence of compelling clinical conditions, reference thresholds for diagnosing hypertension are 120/70 mmHg for the asleep systolic/diastolic BP means derived from ambulatory BP monitoring. However, in women, in the absence of complicating co-morbidities, the same thresholds are lower by 10/5 mmHg, i.e., 110/65 mmHg for the asleep means. In high-risk patients, including those diagnosed with diabetes or chronic kidney disease, and/or those having experienced past cardiovascular events, the thresholds are even lower by 15/10 mmHg, i.e., 105/60 mmHg. Bedtime treatment with the full daily dose of ≥1 hypertension medications is recommended as a cost-effective means to improve the management of hypertension and reduce hypertension-associated risk. Bedtime treatment entailing the full daily dose of ≥1 conventional hypertension medications must be the therapeutic regimen of choice for the elderly and those with diabetes, resistant and secondary hypertension, chronic kidney disease, obstructive sleep apnea, and medical history of past cardiovascular events, among others, given their documented high prevalence of sleep-time hypertension.
Abstract Inconsistencies between equations for the effective population size of populations with separate sexes obtained by two different approaches are explained. One approach, which is the most common in the literature, is based on the assumption that the sex of the progeny cannot be identified. The second approach incorporates identification of the sexes of both parents and offspring. The approaches lead to identical expressions for effective size under some situations, such as Poisson distributions of offspring numbers. In general, however, the first approach gives incorrect answers, which become particularly severe for sex-linked genes, because then only numbers of daughters of males are relevant. Predictions of the effective size for sex-linked genes are illustrated for different systems of mating.
To recognize the highly statistically significant circadian variability of lood pressure (BP) in pregnancy [Hermida et al. Hypertension 2000; 36:149-158] is to admit that the diagnosis of hypertensive complications in pregnancy should be based not just on whether a casual BP value is too high or too low, but rather on more pertinent questions: How long is BP elevated above a given time-varying threshold? What is the excess BP? When most of the excess occurs? Answers to these questions may be obtained by establishing, first, an adequate reference BP threshold and, second, a proper measurement of BP elevation [Hermida et al. Hypertension 1998;31:83-89]. Accordingly, we derived time-specified reference standards for BP as a function of gestational age. We analyzed 1404 BP series systematically sampled from 234 women with uncomplicated pregnancies. BP was measured every 20 minutes during the day and every 30 minutes during the night for 48 hours with an ambulatory device once every 4 weeks from the first visit to the hospital (usually within the first trimester of gestation) until delivery. Data from each BP series were synchronized according to the rest-activity cycle of each individual in order to avoid differences among subjects in actual times of daily activity. Data were then used to compute 90% circadian tolerance intervals for each trimester of pregnancy, in keeping with the trends in BP along gestation previously documented [Ayala et al. Hypertension 1997;30:611-618]. The method, derived on the basis of bootstrap techniques, does not need to assume normality or symmetry in the data and, therefore, it is highly appropriate to describe the circadian pattern of BP variability [Hermida et al. Biomed Instrum Technol 1996;30:257-266]. Results not only reflect expected changes in the tolerance limits as a function of gestational age, but also upper limits markedly below the thresholds currently used for diagnosing hypertension in pregnancy. The use of these time-dependent tolerance limits for the computation of a hyperbaric index as a measure of BP excess [Hermida et al. Hypertension 1998;31:83-89] has already been show to provide high sensitivity and specificity in the early identification of gestational hypertension and preeclampsia.
