This review examined the literature to spot uses, if any, of physiological solutions/media for the in situ synthesis of calcium phosphates (CaP) under processing conditions (i.e. temperature, pH, ...concentration of inorganic ions present in media) mimicking those prevalent in the human hard tissue environments. There happens to be a variety of aqueous solutions or media developed for different purposes; sometimes they have been named as physiological saline, isotonic solution, cell culture solution, metastable CaP solution, supersaturated calcification solution, simulated body fluid or even dialysate solution (for dialysis patients). Most of the time such solutions were not used as the aqueous medium to perform the biomimetic synthesis of calcium phosphates, and their use was usually limited to the in vitro testing of synthetic biomaterials. This review illustrates that only a limited number of research studies used physiological solutions or media such as Earle’s balanced salt solution, Bachra et al. solutions or Tris-buffered simulated body fluid solution containing 27mM HCO3- for synthesizing CaP, and these studies have consistently reported the formation of X-ray-amorphous CaP nanopowders instead of Ap-CaP or stoichiometric hydroxyapatite (HA, Ca10(PO4)6(OH)2) at 37°C and pH 7.4. By relying on the published articles, this review highlights the significance of the use of aqueous solutions containing 0.8–1.5 mMMg2+, 22–27mM HCO3-, 142–145mM Na+, 5–5.8mM K+, 103–133mM Cl−, 1.8–3.75mM Ca2+, and 0.8–1.67mM HPO42-, which essentially mimic the composition and the overall ionic strength of the human extracellular fluid (ECF), in forming the nanospheres of X-ray-amorphous CaP.
Front of pack nutrition labelling is part of United Kingdom government's programme of activities aiming to tackle diet-related diseases. There are several front of pack labelling formats available ...and they differ in the information they deliver. This study assessed the frequency of usage of front of pack food labelling systems on food products in the United Kingdom grocery market. It also measured the healthiness of some foods in the online market by categorising them according to their nutrient contents.
Five hundred food products in five categories (1) cereals and cereal products, (2) dairy products, (3) beverages, (4) packaged meats and meat products, and (5) pre-packaged fruits and vegetables from three main United Kingdom retail websites were investigated. A simple random sampling method was used for product selection according to the categories on the retailers' websites. The healthiness of foods was also assessed by categorising them into 'healthier', 'moderately healthy' and 'least healthy' based on fat, saturated fat, salt and sugar contents.
The total number of label types assessed comprises 19.6% of Guideline Daily Amounts or Reference Intakes and 43.8% had a combination of Traffic Light and Reference Intakes (hybrid label). Slightly over a quarter (27.4%) of products included nutritional information in a grid or table, 3.4% of the foods had two of any of the following: Health Logo, Reference Intakes and Traffic Light labels, and 5.8% did not have any Reference Intakes, Traffic Light, Health Logo or Hybrid label. Most of the foods assessed were manufactured in the United Kingdom with only 30.8% imported from 32 countries across four continents.
Traffic Light and Guideline Daily Amounts were the most used front of pack labelling formats on the assessed food product. A higher number of assessed products belonged to the "moderately healthy" and "healthier" categories than the "least healthy". The imported foods that were found in the United Kingdom retail market showed that food choices could be made from the diverse food types.
A straightforward process was developed to synthesize monetite (CaHPO4, dicalcium phosphate anhydrous) powders at room temperature (21°±1°C) in ethanol solutions. The process reported here ...constitutes an alternative to well‐publicized monetite synthesis procedures based on the dehydration of brushite (CaHPO4·2H2O, dicalcium phosphate dihydrate) powders either in acidic, hot (70°–95°C) aqueous solutions or in drying ovens (200°–225°C). Submicrometer monetite powders were synthesized in ethanol (ethyl alcohol) solutions containing small aliquots of concentrated H3PO4 (orthophosphoric acid, 85%). Precipitated CaCO3 (calcium carbonate, calcite form) powders with submicrometer particles were simply stirred in the above solutions in glass bottles for 3 h. The starting Ca/P molar ratio in the synthesis bottles was 0.50. Monetite powders obtained with a stacked‐nanosheets particle texture did not contain any unreacted CaCO3. Monetite powders were also found to have the ability to completely transform into apatitic (apatite‐like) calcium phosphate powders when soaked in calcium‐containing saline solutions (i.e., 142 mM Na+, 5 mM K+, and 50 mM Ca2+ in water) for 6 days at 37°C.
Brushite (dicalcium phosphate dihydrate, DCPD, CaHPO4·2H2O) and whitlockite WH, Ca9Mg(HPO4)(PO4)6 are usually found in the mammalian metabolism in the form of diverse pathological calcifications, ...dental calculi, urinary tract stones, salivary gland deposits, cardiovascular or pulmonary calcified deposits, and even as prostate or cartilage calcifications. The hydrothermal transformation of synthetic brushite crystals into single‐phase whitlockite, octacalcium phosphate, or apatitic calcium phosphate was observed over the time period of 1 to 21 d and at 37°C, 70°C, and 115°C in nonstirred physiologically relevant solutions developed for this work. The strong influence of the physiologically relevant ions such as Mg2+ and HCO3− on hydrothermal transformations is exposed. The formation of the nanoglobules and nanofibrils of X‐ray amorphous calcium phosphate or Mg‐doped calcium phosphate on the surfaces of brushite crystals are observed for the first time in biomimetic solutions containing 10 mm Mg2+ and/or 27 mm HCO3−. The experimental conditions leading to the formation of such nanofibrils on brushite crystal surfaces are also found to stop the further transformation of brushite into any other calcium phosphate (CaP) phases even at high solution temperatures. Samples were characterized by scanning electron microscopy and powder X‐ray diffraction.
There is substantial debate over whether visual working memory (VWM) and visual attention constitute a single system for the selection of task-relevant perceptual information or whether they are ...distinct systems that can be dissociated when their representational demands diverge. In the present study, we focused on the relationship between visual attention and the encoding of objects into VWM. Participants performed a color change-detection task. During the retention interval, a secondary object, irrelevant to the memory task, was presented. Participants were instructed either to execute an overt shift of gaze to this object (Experiments 1-3) or to attend it covertly (Experiments 4 and 5). Our goal was to determine whether these overt and covert shifts of attention disrupted the information held in VWM. We hypothesized that saccades, which typically introduce a memorial demand to bridge perceptual disruption, would lead to automatic encoding of the secondary object. However, purely covert shifts of attention, which introduce no such demand, would not result in automatic memory encoding. The results supported these predictions. Saccades to the secondary object produced substantial interference with VWM performance, but covert shifts of attention to this object produced no interference with VWM performance. These results challenge prevailing theories that consider attention and VWM to reflect a common mechanism. In addition, they indicate that the relationship between attention and VWM is dependent on the memorial demands of the orienting behavior.
An important inorganic phase for synthetic bone applications, calcium hydroxyapatite (HA, Ca
10(PO
4)
6(OH)
2), was prepared as a nano-sized (∼50
nm), homogeneous and high-purity ceramic powder from ...calcium nitrate tetrahydrate and diammonium hydrogen phosphate salts dissolved in modified synthetic body fluid (SBF) solutions at 37°C and pH of 7.4 using a novel chemical precipitation technique. The synthesized precursors were found to easily reach a phase purity >99% after 6
h of calcination in air atmosphere at 900°C, following oven drying at 80°C. There was observed, surprisingly, no decomposition of HA into the undesired
β-TCP phase even after heating at 1600°C in air for 6
h. This observation showed the superior high-temperature stability of such `biomimetic’ HA powders as compared to those reported in previous studies. The former powders were also found to contain trace amounts of Na and Mg ions, originating from the use of SBF solutions instead of pure water during their synthesis. Characterization and chemical analaysis of the synthesized powders were performed by X-ray powder diffraction, energy-dispersive X-ray spectroscopy, Fourier-transform infra-red spectroscopy, scanning electron microscopy, and inductively coupled plasma atomic emission spectroscopy.
Object-mediated overwriting across saccades Tas, A Caglar; Mordkoff, J Toby; Hollingworth, Andrew
Journal of vision (Charlottesville, Va.),
02/2021, Letnik:
21, Številka:
2
Journal Article
Recenzirano
Odprti dostop
How are visual sensory representations that are acquired peripherally from a saccade target related to sensory representations generated foveally after the saccade? We tested the hypothesis that, ...when the two representations are perceived to belong to the same object, the post-saccadic value tends to overwrite the pre-saccadic value. Participants executed a saccade to a colored target object, which sometimes changed during the saccade by ±15°, 30°, or 45° in color space. They were post-cued to report either the pre-saccadic or post-saccadic color in a continuous report procedure. Substantial overwriting of the pre-saccadic color by the post-saccadic color was observed. Moreover, the introduction of a brief post-saccadic blank interval (which disrupted the perception of object correspondence) led to a substantial reduction in overwriting. The results provide the first direct evidence for an object-mediated overwriting mechanism across saccades, in which post-saccadic values automatically replace pre-saccadic values.
Consumers' eating habits have changed significantly due to the anxiety and boredom from the reported cases and deaths of COVID-19, the change in work patterns, controlled food shopping, and the ...inability to meet loved ones during the lockdown. The magnitude of these changes in the eating behaviours and purchasing habits of consumers varies across different groups of people. This study provides empirical evidence of the effects of COVID-19 on the eating and purchasing behaviours of people living in England, which was assessed based on sociodemographic variables. A total of 911 participants were recruited by a market research company, while only 792 useable responses were included in this study. The participants, aged between 18 and 91 years, completed an online questionnaire, and the data were analysed using ordinal regression. Data were collected between October and December 2020. Male participants constituted 34.60%, females 63.89%, and others (other gender and those who prefer not to declare their gender) were 0.63%. The majority of participants' ages fell into the ranges of 23-38 and 39-54. Participants aged 23 to 38 years had the greatest effect of COVID-19 on their purchasing decision of healthier foods, while participants in the age groups 55-73 and 74-91 were least affected. The amount of foods purchased during the pandemic decreased with increasing age. The amount of foods purchased by students, people in employment, and people from minority ethnic groups were greatly affected by the pandemic. All participants who stated that taking food supplements is not important during the pandemic were from the White ethnic group. The effects of the pandemic on purchasing healthier foods were greater in younger generations and participants in full- or part-time employment than participants who were retired and who were aged above 55. The participants with higher educational qualifications and those from minority ethnic groups were also more affected by the pandemic. We suggest further studies to monitor any changes in the effects of the ongoing COVID-19 pandemic on the eating and purchasing behaviours of consumers.
With each saccade, visual information is disrupted, and the visual system is tasked with establishing object correspondence between the presaccadic and postsaccadic representations of the saccade ...target. There is substantial evidence that the visual system consults spatiotemporal continuity when determining object correspondence across saccades. The evidence for surface feature continuity, however, is mixed. Surface features that are integral to the saccade target object's identity (e.g., shape and contrast polarity) are informative of object continuity, but features that may only imply the state of the object (e.g., orientation) are ignored. The present study tested whether color information is consulted to determine transsaccadic object continuity. We used two variations of the intrasaccadic target displacement task. In Experiments 1 and 2, participants reported the direction of the target displacement. In Experiments 3 and 4, they instead reported whether they detected any target movement. In all experiments, we manipulated the saccade target's continuity by removing it briefly (i.e., blanking) and by changing its color. We found that large color changes can disrupt stability and increase sensitivity to displacements for both direction and movement reports, although not as strongly as long blank durations (250 ms). Interestingly, even smaller color changes, but not blanking, reduced response biases. These results indicate that disrupting surface feature continuity may impact the process of transsaccadic object correspondence more strongly than spatiotemporal disruptions by both increasing the sensitivity and decreasing the response bias.
Dysphagia is an underlying symptom of many health issues affecting a person's ability to swallow. Being unable to swallow correctly may limit food intake and subsequently micronutrient status. The ...elderly may be the most at risk group of suffering dysphagia as well as most likely to be deficient in micronutrients. The use of texture-modified meals is a common approach to increasing dysphagia sufferer's food intake. The modification of food may affect the micronutrient content and currently there is a limited number of studies focusing on micronutrient content of texture-modified meals. This review considers the prevalence of dysphagia within the elderly UK community whilst assessing selected micronutrients. Vitamin B
12
, C, D, folate, zinc and iron, which are suggested to be most likely deficient in the general elderly UK population, were reviewed. Each micronutrient is considered in terms of prevalence of deficiency, metabolic function, food source and processing stability to provide an overview with respect to elderly dysphagia sufferers.
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