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1.
Environ Sci Pollut Res Int ; 31(10): 15973-15985, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38308782

RESUMO

Sustainability is a core topic for all sectors including geotechnical engineering (e.g., design of foundations, earthworks structures, and pavements for major infrastructure and building projects). Despite being comprised of environmental, economic, and social pillars, most sustainability studies in this area have focused on the first. Furthermore, social impacts and the three pillars integration are little explored. As a result, there is a lack of systemic and holistic assessments of innovative geotechnical alternatives. This research advances in this area by performing a complete sustainability assessment and integration of the environmental, economic, and social pillars of two expansive soil stabilization alternatives: (i) sugar cane bagasse ash combined with hydrated eggshell lime alkali-activated by sodium hydroxide (NaOH) and (ii) Portland cement. Individual analyses were carried out to determine the environmental, economic, and social impacts, and the single sustainability index. Alkali-activated binder dosages showed higher impacts in 4 out of 10 environmental categories. For both binders, high-density/low-binder dosages contributed to environmental and economic sustainability as they require lower quantities of raw materials and diesel for materials transportation. The total costs of alkali-activated binder dosages ($189.79 and $154.45) were higher than that of Portland cement ($72.49 and $54.04), mainly due to the high cost of NaOH acquisition. However, the alkali-activated binder dosages implied lower carbon dioxide (CO2) emissions and thus lower social cost of CO2. The alternative binder presented a higher positive social impact. The alkali-activated high-density/low binder dosage is the most sustainable soil stabilization strategy.


Assuntos
Celulose , Saccharum , Solo , Animais , Solo/química , Mudança Social , Dióxido de Carbono , Casca de Ovo , Hidróxido de Sódio , Álcalis
2.
Aust Endod J ; 50(1): 78-88, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37964493

RESUMO

This study aimed to assess the calcium (Ca2+) and hydroxyl (OH-) ion-releasing ability, namely the biointeractivity of eggshell-derived hydroxyapatite (ESDHA) in comparison with mineral trioxide aggregate (MTA) and calcium hydroxide (CH). ESDHA, MTA and CH samples (n = 10; 8 × 1.6 mm) were immersed in 10 mL of deionised water (37°C, pH 6.8). Ca2+ and OH- ion releases were detected in 1, 7 and 21 days. Scanning electron microscopy and Fourier transform infrared spectroscopy analyses were also conducted. IBM SPSS 20.0 was used for statistical analyses. The cumulative Ca2+ ions (56.22 ± 11.28 ppm) were detected as most significant in ESDHA (day 21; p < 0.05). The OH- ion values of the ESDHA group were statistically higher than MTA and CH (days 1 and 7; p < 0.05). ESDHA and CH showed a similar pattern with sharp peaks in Ca2+, oxygen and carbon elements. ESDHA being a sustainable material with a high ion-releasing ability may be a preferable alternative to the commercial vital pulp therapy agents.


Assuntos
Compostos de Cálcio , Capeamento da Polpa Dentária , Animais , Capeamento da Polpa Dentária/métodos , Casca de Ovo , Silicatos/farmacologia , Hidróxido de Cálcio , Durapatita , Óxidos , Combinação de Medicamentos , Compostos de Alumínio
3.
J Appl Biomater Funct Mater ; 21: 22808000231180390, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37688383

RESUMO

OBJECTIVES: Dentine hypersensitivity (DH) is a common concern in dentistry that has the potential to restrict daily activities and harm a person's quality of life. In this study, the remineralization characteristics of nano-hydroxyapatite (nHAp) extracted from waste eggshells and fish scales were comparatively assessed. MATERIALS AND METHODS: The extraction methods used to obtain nHAp from both fish scales and eggshells are also described. The effect of the extraction process and bio-waste source on the physicochemical characteristics of the nHAp such as Ca/P ratio, functional groups, crystallinity and phase change, and surface morphology are presented in the study. The remineralization properties were evaluated using dentine models (n = 15). A field scanning electron microscope was used to evaluate the effectiveness of the dentine tubules occlusion. The percentage occluded area for all the specimens was evaluated statistically using a one-way analysis of variance (α = 0.05). RESULTS: The results showed that there were variations in the physicochemical characteristics of the nHAp extracted, including the crystallinity, particle size, and surface morphology, and buffering effects against citric acids. The EnHAp extracted from eggshells had higher crystallinity, superior buffering effects, and smaller particle size compared to the nHAp extracted from fish scales, making it a more favourable material for remineralization of teeth. The statistical evidence showed that there were statistically significant differences in the dentine occluding properties measured in the nHAp (p < 0.001). The highest mean % occluded area was measured with the EnHAp group. CONCLUSIONS: The findings of this study provide insights into the use of bio-waste materials for the development of sustainable and effective products for oral health care.


Assuntos
Durapatita , Casca de Ovo , Animais , Humanos , Durapatita/química , Casca de Ovo/química , Qualidade de Vida , Microscopia Eletrônica de Varredura , Remineralização Dentária/métodos
4.
Poult Sci ; 102(10): 102934, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37499614

RESUMO

The objective of the current study was to conduct an initial comparison of commercial yeast products in layer hen diets on egg production parameters and the corresponding impact on the cecal microbiota. A short-term feeding study was conducted with 35 laying hens receiving either a control, or 1 of 4 different yeast fermentation products, Immunowall, Hilyses (both from ICC, São Paulo, Brazil), Citristim (ADM, Decatur, IL), and Maxi-Gen Plus (CBS Bio Platforms, Calgary, Canada) with 7 hens per treatment from 40 to 46 wk of age. At the end of the trial, hens were euthanized, the ceca removed and prepared for denatured gradient gel electrophoresis (DGGE) microbial compositional analyses. Although initial shell weight and shell thickness were similar among the treatment groups, hens fed Hilyses had lower shell weight and thickness at the end of the experiment. The most predominant DGGE bands with the strongest intensity were identified as Lactobacillus species and excised double bands were identified as Bacillus, Clostridium, or Lachnospiraceae. In this short-term feeding trial, the commercial yeast products tested had little effect on egg production and shell quality, and only moderately impacted the composition of mature layer hen cecal microbiota.


Assuntos
Galinhas , Fermento Seco , Animais , Feminino , Ração Animal/análise , Brasil , Ceco , Dieta/veterinária , Casca de Ovo
5.
ACS Biomater Sci Eng ; 9(8): 4673-4685, 2023 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-37399249

RESUMO

In this work, a titanium-doped hydroxyapatite (HAp) scaffold was produced from two different sources (natural eggshell and laboratory-grade reagents) to compare the efficacy of natural and synthetic resources of HAp materials on new bone regeneration. This comparative study also reports the effect of Ti doping on the physical, mechanical, and in vitro as well as in vivo biological properties of the HAp scaffold. Pellets were prepared in the conventional powder metallurgy route, compacted, and sintered at 900 °C, showing sufficient porosity for bony ingrowth. The physical-mechanical characterizations were performed by density, porosity evaluation, XRD, FTIR, SEM analysis, and hardness measurement. In vitro interactions were evaluated by bactericidal assay, hemolysis, MTT assay, and interaction with simulated body fluid. All categories of pellets showed absolute nonhemolytic and nontoxic character. Furthermore, significant apatite formation was observed on the Ti-doped HAp samples in the simulated body fluid immersion study. The developed porous pellets were implanted to assess the bone defect healing in the femoral condyle of healthy rabbits. A 2 month study after implantation showed no marked inflammatory reaction for any samples. Radiological analysis, histological analysis, SEM analysis, and oxytetracycline labeling studies depicted better invasion of mature osseous tissue in the pores of doped eggshell-derived HAp scaffolds as compared to the undoped HAp, and laboratory-made samples. Quantification using oxytetracycline labeling depicted 59.31 ± 1.89% new bone formation for Ti-doped eggshell HAp as compared to Ti-doped pure HAp (54.41 ± 1.93) and other undoped samples. Histological studies showed the presence of abundant osteoblastic and osteoclastic cells in Ti-doped eggshell HAp in contrast to other samples. Radiological and SEM data also showed similar results. The results indicated that Ti-doped biosourced HAp samples have good biocompatibility, new bone-forming ability, and could be used as a bone grafting material in orthopedic surgery.


Assuntos
Durapatita , Oxitetraciclina , Animais , Coelhos , Durapatita/farmacologia , Titânio/farmacologia , Casca de Ovo , Regeneração Óssea , Modelos Animais
6.
Molecules ; 28(12)2023 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-37375207

RESUMO

Engineering research has been expanded by the advent of material fusion, which has led to the development of composites that are more reliable and cost-effective. This investigation aims to utilise this concept to promote a circular economy by maximizing the adsorption of silver nanoparticles and silver nitrate onto recycled chicken eggshell membranes, resulting in optimized antimicrobial silver/eggshell membrane composites. The pH, time, concentration, and adsorption temperatures were optimized. It was confirmed that these composites were excellent candidates for use in antimicrobial applications. The silver nanoparticles were produced through chemical synthesis using sodium borohydride as a reducing agent and through adsorption/surface reduction of silver nitrate on eggshell membranes. The composites were thoroughly characterized by various techniques, including spectrophotometry, atomic absorption spectrometry, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy, as well as agar well diffusion and MTT assay. The results indicate that silver/eggshell membrane composites with excellent antimicrobial properties were produced using both silver nanoparticles and silver nitrate at a pH of 6, 25 °C, and after 48 h of agitation. These materials exhibited remarkable antimicrobial activity against Pseudomonas aeruginosa and Bacillus subtilis, resulting in 27.77% and 15.34% cell death, respectively.


Assuntos
Anti-Infecciosos , Nanopartículas Metálicas , Animais , Nanopartículas Metálicas/química , Casca de Ovo/química , Nitrato de Prata/química , Testes de Sensibilidade Microbiana , Prata/farmacologia , Prata/análise , Anti-Infecciosos/química , Espectroscopia de Infravermelho com Transformada de Fourier , Antibacterianos/química
7.
Int Endod J ; 56(9): 1129-1146, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37358385

RESUMO

AIM: Pulp vitality is essential for tooth integrity. Following pulp exposure, choosing a suitable pulp-capping material is crucial to maintain pulp vitality. However, the reparative dentine bridge created by calcium hydroxide (Ca(OH)2 ) is generally porous and incomplete. The aim of the current study is to assess the in vitro and in vivo bioactivities of nano eggshell-based slurry (NES), using NES as a direct pulp-capping material, compared with Ca(OH)2 in rabbit animal model. METHODOLOGY: Nano eggshell powder (NE) was characterized for particle morphology, chemical composition and ion release. In vitro bioactivity was tested by immersion in simulated body fluid (SBF) for 7 days. For histopathological evaluation, 36 adult New Zealand rabbits (72 pulp exposures) were divided into nine groups (n = 8) according to the pulp-capping material (NES, Ca(OH)2 and no capping as negative control group) and the animals were sacrificed after 7, 14 or 28 days. The pulps of the two lower central incisors were exposed and then directly capped by Ca(OH)2 or NES or left untreated. The cavities were then sealed with glass ionomer cement. Teeth were collected for histopathological evaluation using an optical microscope. Pulp haemorrhage, inflammation, fibrosis and calcific bridge formation were assessed. Results were statistically analysed using anova and Tukey's tests. RESULTS: Nano eggshell particles were spherical with a 20 nm diameter and were composed mainly of calcite. Statistical analysis showed that there was a significant increase in the release of all investigated ions between days 1 and 28, except for copper. NES group showed a significantly higher release of all elements as compared to Ca(OH)2 . Environmental scanning electron microscope micrographs of NES incubated for 7 days in SBF showed the formation of HAp with a Ca/P ratio (1.686). For histopathological evaluation, the difference between groups was statistically significant. At day 28, 75% of the pulps of the Ca(OH)2 group showed mild calcific bridge in comparison with 100% moderate calcific bridge in the NES group. The NES group showed significantly less inflammation at days 7 and 28, and higher fibrosis at day 7 compared with Ca(OH)2 . CONCLUSIONS: Nano eggshell-based slurry represents a promising novel direct pulp-capping material with favourable pulp tissue response.


Assuntos
Hidróxido de Cálcio , Capeamento da Polpa Dentária , Polpa Dentária , Casca de Ovo , Animais , Coelhos , Hidróxido de Cálcio/farmacologia , Polpa Dentária/efeitos dos fármacos , Capeamento da Polpa Dentária/métodos , Dentina Secundária , Inflamação , Modelos Animais
8.
J Environ Manage ; 329: 117092, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36571950

RESUMO

Artemia egg shell loaded with nano-magnesium (shell-Mg) can be used to recover phosphorus from wastewater. The exhausted Artemia egg shell-Mg (denoted as shell-Mg-P) can be used as a slow-release fertilizer for phosphorus reuse. However, due to the coexistence of heavy metal ions in the environment, the application of slow-release fertilizer for phosphorus removal and reuse may have potential risks. In this paper, the potential risks of Pb2+, Cd2+, Zn2+ and Cu2+ in phosphorus wastewater and soil were studied from the formation and application process of shell-Mg-P. The result showed that shell-Mg adsorbed Pb2+, Cd2+, Zn2+ and Cu2+ in phosphate wastewater during the formation of shell-Mg-P and became shell-Mg-P-metal hybrid biomaterial. Although the experiment proved that the existence of heavy metal ions did not affect the phosphorus slow-release behavior of slow-release fertilizer, but the heavy metal ions in the shell-Mg-P-metal were also slow released. The pot experiment results confirmed that the slow-release phosphorus fertilizers (shell-Mg-P and shell-Mg-P-metal) in the soil polluted in low concentration of heavy metals can reduce the amount of heavy metals in whole wheat seedlings and promote wheat seedling growth. However, the application of slow-release fertilizers increased the translocation efficiency (TFR to SL) of metal from root (R) to aboveground part (stem and leaves, SL), promoted the transportation of heavy metals from roots to the stems and leaves, and increased the safety risk of the wheat seedling edible. Therefore, besides the positive role of slow-release fertilizers in retaining heavy metals and reducing the amount of heavy metals in whole seedlings, the risk that it may aggravate the translocation of heavy metals to stems and leaves should be paid more attention, so as to ensure the safe and reliable application of slow-release fertilizers.


Assuntos
Metais Pesados , Poluentes do Solo , Animais , Fertilizantes/análise , Fósforo , Artemia , Cádmio , Águas Residuárias , Casca de Ovo/química , Chumbo , Poluentes do Solo/análise , Metais Pesados/análise , Medição de Risco , Solo , Triticum , Plântula/química
9.
Environ Sci Pollut Res Int ; 29(56): 84814-84826, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35790628

RESUMO

The eggshell powder (ESP) has been used as a partial cement replacement to reduce the cement content in concrete production. According to recent estimates, cement production contributes to 7% of global Carbon Dioxide (CO2) gas emissions. However, most of the studies so far have focused on the mechanical strength aspect of the concrete incorporating ESP; however, there is a lack of information on the influence of ESP on the sustainability of concrete in terms of embodied carbon and eco-strength efficiency. Therefore, this study aims at determining the influence of ESP on the sustainability and cost of an M40 grade concrete when different fineness ESP (50 µm and 100 µm) is utilized as partial cement replacement. The sustainability was assessed in terms of embodied carbon and eco-strength efficiency, while the cost-effectiveness was determined in terms of the overall cost of concrete and cost to produce unit compressive strength. It was observed that the control M40 concrete mix achieved a total embodied carbon of 482.88 kgCO2/m3. With 5 to 15% ESP of 100 µm fineness, the total embodied carbon was successfully reduced, ranging from 3.86 to 11.60%. While 5 to 15% of 50 µm fineness, the reduction ranged from 3.69 to 11.10%. The 50 µm fineness ESP exhibited slightly lower eco-strength efficiency compared to 100 µm fineness ESP; however, both achieved relatively higher eco-strength efficiency. In terms of cost, the inclusion of ESP resulted in a significant reduction in overall cost and was cheaper to produce 1 MPa compressive strength.


Assuntos
Materiais de Construção , Casca de Ovo , Animais , Pós , Análise Custo-Benefício , Força Compressiva
10.
Environ Sci Pollut Res Int ; 29(39): 58685-58697, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35366210

RESUMO

Cement production emits a significant carbon dioxide (CO2) gas, dramatically influencing the environment. Furthermore, a large amount of energy is consumed during the cement manufacturing process; since Pakistan is already facing an energy crisis, this high energy consumption by the cement industry puts further stress on Pakistan's energy sector. Hence, the price of cement is rising day by day. Furthermore, waste disposals and concrete ingredients' restoration after demolition have adversative effects on the environment. Therefore, using these wastes decreases cement manufacturing, thereby reducing energy consumption, but it also aids in safeguarding the environment. The study aimed to determine the concrete properties by partially replacing cement with only eggshell powder (ESP) and combining ESP and silica fume (SF) in a ternary binder system in the mixture. However, workability, water absorption, compressive strength, split tensile strength, and flexural strength were all investigated in this study. In this experimental study, cement was replaced as 5, 8, 11, 15, and 20% of ESP, along with 5, 10, and 15% of silica by weight of cement in concrete. Approximately 21 mixes were prepared, from which 01 control mix, 05 mixes of ESP alone, and 15 mixes designed with a blend of ESP and SF with a 1:1.25:3 mix ratio and 0.5 water-cement ratios. Study parameters advocate the substitution of 11% ESP and 10% SF as the optimal option for maximum strength. Furthermore, combining ESP and SF diminishes the composite concrete mixture's workability and dry density greatly.


Assuntos
Materiais de Construção , Dióxido de Silício , Animais , Casca de Ovo , Gases , Pós , Água
11.
Nucleosides Nucleotides Nucleic Acids ; 41(5-6): 566-578, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35337253

RESUMO

Due to human activity, climatic changes and habitat damage, the Chukar partridge (Alectoris chukar) is experiencing a population decrease. The goal of this work was to isolate and identify the inner eggshell microflora in order to learn more about their function in A. chukar embryo mortality and hatchability in semi-captive settings. During the egg-laying season, 204 eggs were gathered from the Balkasar Research Complex in Chakwal, Pakistan. These eggshells were divided into four categories after incubation: un-pricked with dead embryo, pricked with dead embryo, hatched, and unfertilized eggs. A total of 47 (23.03%) samples tested positive for gram-positive bacteria, which were then identified using 16S rRNA sequence analysis. Bacillus subtilis, Bacillus cereus, Bacillus amyloliquefaciens, Bacillus toyonensis, Bacillus thuringiensis and Staphylococcus sciuri were among the identified species. Hatched eggshells had the highest percentage of bacterial flora (36.17%), followed by un-pricked with dead embryo (23.40%) and pricked with death embryo (21.27%), and unfertilized eggshells had the lowest percentage (19.14%). As a result, the findings of this study revealed that microbial contamination of eggshells could be a cause of early embryonic stage degeneration and bird death.


Assuntos
Casca de Ovo , Galliformes , Animais , Galliformes/genética , Paquistão , RNA Ribossômico 16S/genética
12.
Poult Sci ; 101(2): 101589, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34933223

RESUMO

Egg quality parameters are very crucial for the egg industry as egg configuration affects grading, price, hatchability, chick weight, and consumer preference. Current study was undertaken to assess and compare the egg quality parameters in 2 important Indian breeds Aseel and Kadaknath reared under backyard system. Different parameters of external and internal egg quality were measured. Biochemical parameters of egg yolk estimated were egg yolk cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), and triacylglycerol. Means for external characters of Aseel eggs viz., egg weight, egg length, egg width, shape index, shell weight, shell thickness, and shell ratio were 41.7 g, 5.16 cm, 3.85 cm, 74.75%, 4.65 g, 0.35 mm, and 11.23%, and corresponding values for Kadaknath eggs were 40.59 g, 5.13 cm, 3.79 cm, 74.02%, 4.28 g, 0.34 mm, and 10.61%, respectively. Average albumin length, width, height, and albumin index were 83.73 mm, 65.4 mm, 6.02 mm, and 9.26% for Aseel eggs and 82.27 mm, 64.80 mm, 5.52 mm and 8.52% for Kadaknath eggs, respectively. Mean values for yolk length, width, height and yolk index were 43.32 mm, 40.10 mm, 15.30 mm, and 38.30% in Aseel and 42.15 mm, 38.97 mm, 14.26 mm and 36.66% in Kadaknath breed, respectively. Mean values for egg yolk cholesterol, HDL, LDL, and triacylglycerol were estimated as 9.38, 1.74, 0.17, and 1.94 mg/g in Aseel eggs and 8.38, 1.84, 0.11, and 1.76 mg/g in Kadaknath eggs, respectively. Biochemical analysis revealed that egg yolk quality of Kadaknath eggs was comparatively better than Aseel eggs.


Assuntos
Galinhas , Ovos , Aves Domésticas , Agricultura , Animais , Cruzamento , Casca de Ovo , Gema de Ovo , Índia
13.
J Contemp Dent Pract ; 22(5): 532-537, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34318773

RESUMO

AIM: This study aims to evaluate the efficacy of avian eggshell slurry as a desensitizing agent compared to casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) containing Tooth Mousse. MATERIALS AND METHODS: Eggshell powder was prepared and characterized using a scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX). Forty dentin disks were immersed in 6% citric acid for 2 min to simulate hypersensitive dentin (baseline). Disks were then divided into two groups (n = 20) according to treatment received: eggshell slurry and commercially available Tooth Mousse desensitizing agent. Each group was further divided into two subgroups (n = 10). In subgroup 1, dentin discs were immersed in artificial saliva for four weeks whereas, in subgroup 2, discs underwent acid challenge. Environmental scanning electron microscope (ESEM) analysis and hydraulic conductance test were utilized to calculate dentinal tubules occlusion and reduction of dentin permeability percentages, respectively. Statistical analysis was performed using SPSS 22.0 at a significance level p ≤ 0.05. RESULTS: After application of desensitizing agents, the eggshell slurry group showed a significantly higher percentage of dentinal tubules occlusion compared to the Tooth Mousse group, whereas no significant difference existed in the percentage reduction of dentin permeability between both groups. After both immersion protocols, the eggshell slurry significantly occluded more dentinal tubules compared to Tooth Mousse. On the contrary, results of percentage reduction of dentin permeability revealed no significant difference between both subgroups after acid challenge. After artificial saliva immersion, Tooth Mousse showed a significantly higher percentage reduction of dentin permeability compared to the eggshell slurry. CONCLUSION: Avian eggshell slurry can effectively occlude open dentinal tubules compared to commercially available Tooth Mousse desensitizing agent. CLINICAL SIGNIFICANCE: Avian eggshell slurry can be considered a promising material for the treatment of dentin hypersensitivity. How to cite this article: El Tahlawy AA, Saba DA, Bakir NG. Avian Eggshell Slurry as a Dentin Desensitizing Agent: An In Vitro Assessment Using Two Techniques. J Contemp Dent Pract 2021;22(5):532-537.


Assuntos
Dessensibilizantes Dentinários , Sensibilidade da Dentina , Animais , Dentina , Dessensibilizantes Dentinários/farmacologia , Permeabilidade da Dentina , Sensibilidade da Dentina/tratamento farmacológico , Casca de Ovo , Microscopia Eletrônica de Varredura
14.
Nature ; 592(7853): 248-252, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33790469

RESUMO

The archaeological record of Africa provides the earliest evidence for the emergence of the complex symbolic and technological behaviours that characterize Homo sapiens1-7. The coastal setting of many archaeological sites of the Late Pleistocene epoch, and the abundant shellfish remains recovered from them, has led to a dominant narrative in which modern human origins in southern Africa are intrinsically tied to the coast and marine resources8-12, and behavioural innovations in the interior lag behind. However, stratified Late Pleistocene sites with good preservation and robust chronologies are rare in the interior of southern Africa, and the coastal hypothesis therefore remains untested. Here we show that early human innovations that are similar to those dated to around 105 thousand years ago (ka) in coastal southern Africa existed at around the same time among humans who lived over 600 km inland. We report evidence for the intentional collection of non-utilitarian objects (calcite crystals) and ostrich eggshell from excavations of a stratified rockshelter deposit in the southern Kalahari Basin, which we date by optically stimulated luminescence to around 105 ka. Uranium-thorium dating of relict tufa deposits indicates sporadic periods of substantial volumes of fresh, flowing water; the oldest of these episodes is dated to between 110 and 100 ka and is coeval with the archaeological deposit. Our results suggest that behavioural innovations among humans in the interior of southern Africa did not lag behind those of populations near the coast, and that these innovations may have developed within a wet savannah environment. Models that tie the emergence of behavioural innovations to the exploitation of coastal resources by our species may therefore require revision.


Assuntos
Arqueologia , Carbonato de Cálcio/análise , Casca de Ovo , Pradaria , Invenções/história , Chuva , Struthioniformes , África Austral , Animais , Carbonato de Cálcio/química , Cavernas , História Antiga , Humanos , Magnésio , Tório , Urânio
15.
Environ Sci Pollut Res Int ; 28(27): 35887-35901, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33682053

RESUMO

In this study, the use of eggshells was suggested as an adsorbent for fluoride removal, and their mechanism of fluoride removal was investigated. The eggshells underwent thermal treatment to improve their adsorption capacity; 800 °C was found to be the optimal temperature for treatment. Eggshells thermally treated at 800 °C (ES-800) were mainly composed of Ca (82.4%) and C (15.9%), and the peaks of ES-800 obtained from X-ray diffraction (XRD) corresponded to calcite, portlandite, and lime. Fluorine adsorption by ES-800 reached 70% of the equilibrium adsorption amount within 15 min and gradually increased until 24 h. The maximum adsorption capacity of ES-800 at pH 7 and 25 °C was 258.28 mg/g, which is 18 times larger than that of activated alumina; this is classified as the best available technology by the United States Environmental Protection Agency. Both enthalpy and entropy increased in the process of fluoride adsorption onto ES-800. Fluoride adsorption of ES-800 decreased from 59.16 to 11.85 mg/g with an increase in pH from 3 to 11. Fluoride adsorption decreased in the presence of anions, whose impact follows the order: HPO43- > HCO3- >> SO42- > Cl-. XRD, and X-ray photoelectron spectroscopy analysis revealed that fluoride removal was achieved by the formation of calcium fluorite (CaF2). Thus, it can be concluded that eggshells can function as highly efficient adsorbents for fluoride removal, replacing bone char and activated alumina; further, their adsorption capacity can be improved by thermal treatment.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Adsorção , Animais , Casca de Ovo , Fluoretos , Concentração de Íons de Hidrogênio , Cinética
16.
Sci Total Environ ; 732: 139210, 2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32438180

RESUMO

Eggshell pigmentation has been assessed as an indicator of exposure to environmental pollutants in birds, but these studies have only used reflectance spectrophotometry to measure such pigmentation. The present study is the first one that measures eggshell pigments and pollutants in the same eggs to explore their use as biomarkers in birds. We have studied the concentration of organochlorine pesticides and polychlorinated biphenyls (PCBs) in the content of 97 deserted eggs of gull-billed terns (Gelochelidon nilotica) after the abandonment of the colony in Mesas de Asta (Cádiz, S Spain) in 2012. Eggshell thickness and stage of embryo development were studied together along with the concentrations of protoporphyrin IX and biliverdin in eggshells. p,p'-DDE concentrations were high when compared with other studies done with terns in the Mediterranean basin in the past. p,p'-DDE and PCB levels associated with reduced reproductive success were found in 5.1% and 2.1% of the eggs respectively. Eggshell index was largely affected by the embryo development stage, which highlights the need of knowing this information to avoid potential biases in the interpretation of results. The concentrations of protoporphyrin IX and biliverdin in the eggs of gull-billed terns were negatively associated with DDTs levels, which seems to confirm previous observations with phylogenetically related species.


Assuntos
Charadriiformes , Animais , Biomarcadores , Casca de Ovo , Poluentes Ambientais , Pigmentação , Bifenilos Policlorados , Espanha
17.
J Food Prot ; 83(5): 767-778, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32294762

RESUMO

ABSTRACT: According to the U.S. Food and Drug Administration's (FDA's) rule on "Prevention of Salmonella Enteritidis in Shell Eggs during Production, Storage, and Transportation," shell eggs intended for human consumption are required to be held or transported at or below 45°F (7.2°C) ambient temperature beginning 36 h after time of lay. Meanwhile, eggs in hatcheries are typically stored at a temperature of 65°F (18.3°C). Although most of those eggs are directed to incubators for hatching, excess eggs have the potential to be diverted for human consumption as egg products through the "breaker" market if these eggs are refrigerated in accordance with FDA's requirement. Combining risk assessment models developed by the U.S. Department of Agriculture's Food Safety and Inspection Service for shell eggs and for egg products, we quantified and compared Salmonella Enteritidis levels in eggs held at 65°F versus 45°F, Salmonella Enteritidis levels in the resulting egg products, and the risk of human salmonellosis from consumption of those egg products. For eggs stored 5 days at 65°F (following 36 h at 75°F [23.9°C] in the layer house), the mean level of Salmonella Enteritidis contamination is 30-fold higher than for eggs stored at 45°F. These increased levels of contamination lead to a 47-fold increase in the risk of salmonellosis from consumption of egg products made from these eggs, with some variation in the public health risk on the basis of the egg product type (e.g., whole egg versus whole egg with added sugar). Assuming that 7% of the liquid egg product supply originates from eggs stored at 65°F versus 45°F, this study estimates an additional burden of 3,562 cases of salmonellosis per year in the United States. A nominal range uncertainty analysis suggests that the relative increase in the risk linked to the storage of eggs at higher temperature estimated in this study is robust to the uncertainty surrounding the model parameters. The diversion of eggs from broiler production to human consumption under the current storage practices of 65°F (versus 45°F) would present a substantive overall increase in the risk of salmonellosis.


Assuntos
Casca de Ovo/microbiologia , Armazenamento de Alimentos/instrumentação , Intoxicação Alimentar por Salmonella , Salmonella enteritidis/crescimento & desenvolvimento , Animais , Galinhas , Ovos/microbiologia , Microbiologia de Alimentos , Inocuidade dos Alimentos , Humanos , Intoxicação Alimentar por Salmonella/etiologia , Estados Unidos
18.
Water Sci Technol ; 79(10): 1922-1933, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31294709

RESUMO

Hybrid adsorbents (ES) were prepared with mixing of eggshell and sericite as binders, and Pb(II) was removed from aqueous solutions. Sericite has the advantage of not only serving as a binder for hybrid adsorbent but also having a negative charge on the surface to improve the removal efficiency of heavy metals. Various parameters affecting the removal of Pb(II) from aqueous solutions were investigated using the optimal conditions derived. In addition, adsorption kinetics, adsorption isotherms and thermodynamic analyses were performed using the experimental results of each parameter. The ES had a more specific surface area and porosity than sericite or eggshell and contained a large number of OH groups favoring heavy metal adsorption. As a result of the adsorption of Pb(II) using the ES, the adsorption process was physical and suitable for the Freundlich isotherm. In addition, the adsorption process of Pb(II) by the ES was a spontaneous endothermic reaction. The ES can quickly reach the adsorption equilibrium and strong adsorption strength. In addition, the CaOH contained in the ES can neutralize the pH of wastewater, and it is possible to treat heavy metal ions in industrial wastewater and acid mine wastewater without controlling the pH. ES adsorbents using waste eggshells are very economic because they recycle what would otherwise be waste and have great significance in terms of resource reuse.


Assuntos
Chumbo/análise , Poluentes Químicos da Água/análise , Adsorção , Animais , Casca de Ovo/química , Cinética , Dióxido de Silício/química , Termodinâmica , Purificação da Água/métodos
19.
Water Environ Res ; 91(12): 1600-1612, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31188507

RESUMO

A hybrid adsorbent (CES), coffee grounds, eggshell powder and sericite as a binder, was prepared to remove Pb(II) from aqueous solution. The Fourier-transform infrared spectroscopy analysis showed that the CES contained a large amount of OH groups and had a favorable structure for adsorbing heavy metals. The value of pHpzc of CES was estimated at 7.08. In the neutral pH region, the surface of CES is negatively charged and favorable for adsorption of Pb(II). The maximum Langmuir adsorption amount was 155.67 mg/g, and the adsorption process of Pb(II) using CES fitted pseudo-second-order kinetic model and Langmuir isotherm model. Moreover, the analysis of adsorption energy, free energy, enthalpy, and entropy found that the adsorption of Pb(II) onto CES was physical and a spontaneous exothermic reaction. CES is a hybrid adsorbent using general municipal waste and has great advantages in terms of environmental conservation and sustainable environmental circulation. This allows it to compete with other adsorbents. PRACTITIONER POINTS: A hybrid adsorbent, coffee grounds, eggshell, and sericite (CES), was used to remove Pb(II) Adsorption of Pb(II) using CES in an aqueous solution was physical rather than chemical CES contained a large amount of OH groups and had a favorable structure for adsorbing heavy metals The reactivity and strength of the adsorption of Pb(II) onto CES was very good CES has great advantages in terms of environmental conservation and sustainable environmental circulation.


Assuntos
Café , Poluentes Químicos da Água , Adsorção , Animais , Casca de Ovo , Concentração de Íons de Hidrogênio , Cinética , Chumbo , Dióxido de Silício , Termodinâmica
20.
Top Curr Chem (Cham) ; 377(1): 6, 2019 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-30675643

RESUMO

A waste feedstock-derived economical basic alternative catalyst is described in this review. Eggshell is one of the household wastes created in tons of weight daily. Therefore, in order to reduce the environmental pollution-related problems, its use in heterogeneous catalysis can be attributed as a great contribution for the chemical and material science society to carry out several known reactions and for the much-needed energy alternative biodiesel production as low-cost catalytic system. Keeping green chemistry in mind, industrial use of these catalysts may also reduce the use of other traditionally used high-cost chemical catalytic systems.


Assuntos
Biocombustíveis/economia , Biocombustíveis/provisão & distribuição , Catálise , Casca de Ovo/química , Resíduos de Alimentos , Reciclagem/economia , Animais
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