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Materials (Basel, Switzerland) Jun 2024The low-pressure die casting (LPDC) process was experimentally and numerically studied to produce AlSi7Mg0.3 components such as steering knuckles. Steering knuckles are...
The low-pressure die casting (LPDC) process was experimentally and numerically studied to produce AlSi7Mg0.3 components such as steering knuckles. Steering knuckles are important safety components in the context of a vehicle's suspension system, serving as the mechanical interface that facilitates the articulation of the steering to control the front wheel's orientation, while simultaneously bearing the vertical load imposed by the vehicle's weight. This work focuses on the development of a numerical model in ProCAST, replicating the production of the aforementioned part. The model analyses parameters such as the filling dynamics, solidification process, and presence of shrinkage porosities. For the purpose of evaluating the quality of the castings, six parts were produced and characterised, both mechanically (tensile and hardness tests) and microstructurally (porosity and optical microscopy analysis). When correlating simulation results with the available experimental data, it is possible to conclude that the usage of the LPDC process is a viable alternative to the use of steels and other metals for the production of very high-quality castings while using lighter alloys such as aluminium and magnesium in more demanding applications.
PubMed: 38930205
DOI: 10.3390/ma17122835 -
Materials (Basel, Switzerland) Jun 2024Rapid corrosion in aqueous solutions of magnesium alloys is one of the major obstacles to their wide application, and coating plays a crucial role in their corrosion...
Rapid corrosion in aqueous solutions of magnesium alloys is one of the major obstacles to their wide application, and coating plays a crucial role in their corrosion protection. Recently, protection- and function-integrated coatings have attracted much attention in the research field of magnesium alloys. In this work, a simple chemical conversion process is proposed to fabricate a composite coating on a magnesium-neodymium alloy through immersion in an aqueous solution made of Ca(OH) and NaHCO. After the immersion process, a coating consisting of two spontaneously formed layers is acquired. The top flower-like layer is composed of Mg(OH)(CO)∙4HO, Mg(OH) and CaCO, and the inner dense layer is speculated to be Mg(OH). Electrochemical impedance spectroscopy, polarization tests, and hydrogen evolution are combined to evaluate the corrosion resistance in simulated body fluid, simulated seawater solution, and simulated concrete pore solution, which reveals that the coated sample has better corrosion resistance than the uncoated one. After the coated sample is modified with fluorinated silane, a water-repellent surface can be achieved with an average water contact angle of 151.74° and a sliding angle of about 4°. Therefore, our results indicate that effective corrosion protection and potential self-cleaning ability have been integrated on the surface of the magnesium alloy in this study. In addition, the formation mechanism of the self-layered coating is discussed from the viewpoint of the interaction between the substrate and its external solution.
PubMed: 38930185
DOI: 10.3390/ma17122815 -
Journal of Personalized Medicine Jun 2024Obesity is a worldwide epidemic, and bariatric surgery is considered the primary treatment for long-term weight loss and managing obesity-related health issues. Sleeve...
Obesity is a worldwide epidemic, and bariatric surgery is considered the primary treatment for long-term weight loss and managing obesity-related health issues. Sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) are the most performed procedures. Nutritional deficiencies are a significant concern following bariatric surgery and can have serious consequences. This study aims to compare the incidence of nutritional deficiencies in patients undergoing RYGB and SG. A retrospective analysis was conducted on the nutritional status of 505 consecutive patients who underwent either RYGB or SG between January and December 2019. Data were collected regarding vitamin B12, folic acid, vitamin D, calcium, PTH, magnesium, hemoglobin, iron, ferritin, and transferrin at preoperative, 6-month, and 12-month intervals post-surgery. The RYGB group showed significantly higher excess weight loss. Vitamin B12, hemoglobin, and ferritin levels were consistently higher in the SG group throughout the study. Vitamin D deficiency was prevalent, with no significant difference between the groups. Vitamin B12 deficiency was significantly more common in the RYGB group (6 months: 17.46% vs. 4.69%, < 0.001; 12 months: 16.74% vs. 0.93%, < 0.001). Despite differences in their mechanisms, bariatric surgeries were associated with nutritional deficiencies. It is crucial to efficiently assess, prevent, and manage these deficiencies tailored to each surgical procedure.
PubMed: 38929871
DOI: 10.3390/jpm14060650 -
Life (Basel, Switzerland) Jun 2024Divalent magnesium ions (Mg) serve a vital role in defining the structural and catalytic chemistry of a wide array of RNA molecules. The body of structural information...
Divalent magnesium ions (Mg) serve a vital role in defining the structural and catalytic chemistry of a wide array of RNA molecules. The body of structural information on RNA motifs continues to expand and, in turn, the functional importance of Mg is revealed. A combination of prior work on the structural characterization of magnesium binding ligands with inner- and outer-sphere coordination modes, with recorded experimental binding energies for inner- and outer-sphere contacts, demonstrates the relative affinity and thermodynamic hierarchy for these sites. In turn, these can be correlated with cellular concentrations of free available magnesium ions, allowing the prioritization of populating important functional sites and a correlation with physiological function. This paper summarizes some of the key results of that analysis and provides predictive rules for the affinity and role of newly identified Mg binding sites on complex RNA structures. The influence of crystal packing on magnesium binding to RNA motifs, relative to their solution form, is addressed and caveats made.
PubMed: 38929748
DOI: 10.3390/life14060765 -
Life (Basel, Switzerland) Jun 2024The production of citric acid, a vital agricultural commodity utilized across various industries such as food, beverages, pharmaceuticals, agriculture, detergents, and...
The production of citric acid, a vital agricultural commodity utilized across various industries such as food, beverages, pharmaceuticals, agriculture, detergents, and cosmetics, predominantly relies on microbial fermentation, with accounting for approximately 90% of global production. In this study, we aimed to optimize the key factors influencing citric acid production, with a focus on strains, fermentation techniques, and carbon sources, particularly sugarcane molasses. , sourced from the Botany department/Biotechnology laboratories at Govt. College of Science, Lahore, was employed for citric acid production. The process involved inoculum preparation through spore collection from 3 to 5 days of cultured PDA slants. The fermentation medium, comprising cane molasses with a 15% sugar concentration, was meticulously prepared and optimized for various factors, including magnesium sulfate, potassium ferrocyanide, time of addition of potassium ferrocyanide, ammonium oxalate, and calcium chloride. Our optimization results shed light on the significant impact of different factors on citric acid production. For instance, the addition of 0.4 g/L magnesium sulfate led to a maximum yield of 75%, while 2 g/L potassium ferrocyanide, added at 24 h, achieved a yield of 78%. Remarkably, ammonium oxalate, at a concentration of 10 g/L, resulted in a notable 77% yield. Conversely, the addition of calcium chloride exhibited negligible effects on citric acid production, with the control group yielding more at 78%. Our study underscores the potential for optimizing factors to enhance citric acid production by in submerged fermentation. These findings highlight the pivotal role of magnesium sulfate, potassium ferrocyanide, and ammonium oxalate in augmenting citric acid yields while emphasizing the minimal impact of calcium chloride. Ultimately, these insights contribute to advancing our understanding of microbial citric acid biosynthesis, providing valuable implications for industrial applications and future research endeavors.
PubMed: 38929739
DOI: 10.3390/life14060756 -
Animals : An Open Access Journal From... Jun 2024The objective of this study was to evaluate the possible use of spectrophotometric assays for the measurement of trace elements, including Zinc (Zn), Copper (Cu),...
The objective of this study was to evaluate the possible use of spectrophotometric assays for the measurement of trace elements, including Zinc (Zn), Copper (Cu), Magnesium (Mg), and iron (Fe) in the saliva of horses and study their possible changes in equine gastric ulcer syndrome (EGUS). EGUS is a highly prevalent disease, with a current high incidence due to the increase in intensive management conditions. There are two EGUS diseases: equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD), which can appear individually or together. For this purpose, automated spectrophotometric assays for measuring these analytes in horse saliva were analytically validated. Then, these analytes were measured in the saliva of horses with only ESGD, only EGGD, both ESGD and EGGD and a group of healthy horses. The methods used to measure the analytes were precise and accurate. Horses diagnosed with EGGD presented significantly lower levels of Zn and Mg. Fe concentrations were significantly lower in the saliva of horses with ESGD and EGGD. Overall, these results indicate that there are changes in trace elements in saliva in EGUS that could reflect the physiopathological mechanisms involved in this process and open the possibility of using trace elements as biomarkers of this syndrome.
PubMed: 38929343
DOI: 10.3390/ani14121724 -
Foods (Basel, Switzerland) Jun 2024Royal jelly is a substance secreted by the hypopharyngeal and mandibular glands of nurse honey bees, serving as crucial nutritional source for young larvae, queen honey...
Royal jelly is a substance secreted by the hypopharyngeal and mandibular glands of nurse honey bees, serving as crucial nutritional source for young larvae, queen honey bees, and also valuable product for humans. In this study, the effect of the feed supplements on the nutritional composition and qualities of royal jelly was investigated. Two types of royal jelly samples were acquired: one from honey bees fed with sugar syrup as a feed supplement and the other from honey bees fed with honey. The production, harvesting, and storage of all royal jelly samples followed standard procedures. Parameters for quality assessment and nutritional value, including stable carbon isotopic ratio, moisture content, 10-hydroxy-2-decenoic acid (10-HDA) level, carbohydrate composition, amino acid composition, and mineral contents, were analyzed. The results revealed that despite variability in moisture content and carbohydrate composition, fructose was lower (2.6 and 4.1 g/100 g as is for sugar-fed and honey-fed royal jelly, respectively) and sucrose was higher (7.5 and 2.7 g/100 g as is for sugar-fed and honey-fed royal jelly, respectively) in the sugar-fed group. The stable isotope ratio (-16.4608‱ for sugar-fed and -21.9304‱ for honey-fed royal jelly) clearly distinguished the two groups. 10-HDA, amino acid composition, and total protein levels were not significantly different. Certain minerals, such as potassium, iron, magnesium, manganese, and phosphorus were higher in the honey-fed group. Hierarchical analysis based on moisture, sugar composition, 10-HDA, and stable carbon isotopes categorized the samples into two distinct groups. This study demonstrated that the feed source could affect the nutritional quality of royal jelly.
PubMed: 38928885
DOI: 10.3390/foods13121942 -
Foods (Basel, Switzerland) Jun 2024The metabolic needs of the human body and preventing infections require a diet with sufficient amounts of essential nutrients. This study aimed to investigate the...
The metabolic needs of the human body and preventing infections require a diet with sufficient amounts of essential nutrients. This study aimed to investigate the importance of Baobab ( L.) dried leaves as a healthy food source by determining the content of macro and trace elements in different habitats and regions. This study was conducted in Sudan and covered three different habitats, wetland (W), plainland (P), and mountain (M), in two regions (Blue Nile and Kordofan). The dry matter (DM) of Baobab leaves was considered for analyzed menials, and the results showed that the mean values were significantly affected by habitats where Baobab trees grew. The highest contents of potassium K (1653 ± 34 mg/100 g) and sodium (Na) 7.67 ± 1.18 mg/100 g were found in the W zone, whereas the highest contents of calcium (Ca) 2903 ± 187 mg/100 g and magnesium (Mg) 529 ± 101 mg/100 g were detected in the M and P zones, respectively. In addition, the two regions showed significant differences in trace and macro elements, i.e., higher levels of iron (Fe) 17.17 ± 2.76 mg/100 g and magnesium (556 ± 55 mg/100 g) were found in the Kordofan region while higher levels of zinc (Zn) 2.548 ± 0.55 mg/100 g and calcium (2689 ± 305 mg/100) were in the Blue Nile region. These varying amounts of elements can be used in our daily diets because of their potentially healthy effects, especially in areas where access to nutrient-rich foods is limited.
PubMed: 38928879
DOI: 10.3390/foods13121938 -
Foods (Basel, Switzerland) Jun 2024Metals are integral components of the natural environment, and their presence in the food supply is inevitable and complex. While essential metals such as sodium,... (Review)
Review
Metals are integral components of the natural environment, and their presence in the food supply is inevitable and complex. While essential metals such as sodium, potassium, magnesium, calcium, iron, zinc, and copper are crucial for various physiological functions and must be consumed through the diet, others, like lead, mercury, and cadmium, are toxic even at low concentrations and pose serious health risks. This study comprehensively analyzes the presence, importance, and consequences of metals in the food chain. We explore the pathways through which metals enter the food supply, their distribution across different food types, and the associated health implications. By examining current regulatory standards for maximum allowable levels of various metals, we highlight the importance of ensuring food safety and protecting public health. Furthermore, this research underscores the need for continuous monitoring and management of metal content in food, especially as global agricultural and food production practices evolve. Our findings aim to inform dietary recommendations, food fortification strategies, and regulatory policies, ultimately contributing to safer and more nutritionally balanced diets.
PubMed: 38928831
DOI: 10.3390/foods13121890 -
International Journal of Molecular... Jun 2024Zr-50Ti alloys are promising biomaterials due to their excellent mechanical properties and low magnetic susceptibility. However, Zr-50Ti alloys do not inherently bond...
Zr-50Ti alloys are promising biomaterials due to their excellent mechanical properties and low magnetic susceptibility. However, Zr-50Ti alloys do not inherently bond well with bone. This study aims to enhance the bioactivity and bonding strength of Zr-50Ti alloys for orthopedic implant materials. Initially, the surface of Zr-50Ti alloys was treated with a sulfuric acid solution to create a microporous structure, increasing surface roughness and area. Subsequently, low crystalline calcium phosphate (L-CaP) precipitation was controlled by adding Mg and/or CO ions in modified simulated body fluid (m-SBF). The treated Zr-50Ti alloys were then subjected to cold isostatic pressing to force m-SBF into the micropores, followed by incubation to allow L-CaP formation. The apatite-forming process was tested in simulated body fluid (SBF). The results demonstrated that the incorporation of Mg and/or CO ions enabled the L-CaP to cover the entire surface of Zr-50Ti alloys within only one day. After short-term soaking in SBF, the L-CaP layer, modulated by Mg and/or CO ions, formed a uniform hydroxyapatite (HA) coating on the surface of the Zr-50Ti alloys, showing potential for optimized bone integration. After soaking in SBF for 14 days, the bonding strength between the apatite layer and alloy has the potential to meet the orthopedic application requirement of 22 MPa. This study demonstrates an effective method to enhance the bioactivity and bonding strength of Zr-50Ti alloys for orthopedic applications.
Topics: Alloys; Zirconium; Body Fluids; Calcium Phosphates; Surface Properties; Titanium; Biocompatible Materials; Materials Testing; Magnesium; Durapatite
PubMed: 38928293
DOI: 10.3390/ijms25126587