Magnetocaloric Effect of Micro- and Nanoparticles of Gd5Si4

Materials exhibiting a large magnetocaloric effect (MCE) at or near room temperature are critical for solid-state refrigeration applications. The MCE is described by a change in entropy (ΔSM) and/or temperature (ΔTad) of a material in response to a change in applied magnetic field. Ball milled materials generally exhibit smaller ΔSM values compared to bulk; however, milling broadens the effect, potentially increasing the relative cooling power (RCP). The as-cast Gd5Si4 is an attractive option due to its magnetic transition at 340 K and associated MCE. Investigation of effect of particles size and transition temperature in the binary material, Gd5Si4, can lead to development of functionally graded bulk material with higher MCE and RCP than the traditional bulk materials. A two-step ball-milling process, in which coarse powder of Gd5Si4 was first milled with poly(ethylene glycol) followed by milling in heptane was used to produce fine particles of Gd5Si4 that showed a broad distribution in particle size. Magnetic measurement on the milled sample obtained after washing with water show a decrease in Curie temperature and significant broadening of the magnetic transition. Compared to bulk Gd5Si4, the maximum MCE of the milled samples is also reduced and shifted down by close to 30 K, but the MCE remains substantial over a broader temperature range. The RCP of both milled samples increased 75% from the bulk material

Effect of anatomical variability in brain on transcranial magnetic stimulation treatment

Transcranial Magnetic Stimulation is a non-invasive clinical therapy used to treat depression and migraine, and shows further promise as treatment for Parkinson’s disease, Alzheimer’s disease, and other neurological disorders. However, it is yet unclear as to how anatomical differences may affect stimulation from this treatment. We use finite element analysis to model and analyze the results of Transcranial Magnetic Stimulation in various head models.A number of heterogeneous head models have been developed using MRI data of real patients, including healthy individuals as well as patients of Parkinson’s disease. Simulations of Transcranial Magnetic Stimulation performed on 22 anatomically different models highlight the differences in induced stimulation. A standard Figure of 8 coil is used with frequency 2.5 kHz, placed 5 mm above the head. We compare cortical stimulation, volume of brain tissue stimulated, specificity, and maximum E-field induced in the brain for models ranging from ages 20 to 60. Results show that stimulation varies drastically between patients of the same age and health status depending upon brain-scalp distance, which is not necessarily a linear progression with age

Effect of different pretreatments on egyptian sugar-cane bagasse saccharification and bioethanol production

AbstractSugar-cane processing generates large amount of bagasse. Disposal of bagasse is critical for both agricultural profitability and environmental protection. Sugar-cane bagasse is a renewable resource that can be used to produce ethanol.In this study, twelve microbial isolates, five bacteria, four yeasts and three filamentous fungi were isolated from sugar-cane bagasse. Bacterial and yeast isolates were selected for their ability to utilize different sugars and cellulose. Chipped and ground bagasse was subjected to different pretreatment methods; physically through steam treatment by autoclaving at 121°C and 1.5bar for 20min and/or different doses of gamma γ irradiation (50 and 70Mrad). Autoclaved pretreated bagasse was further biologically treated through the solid state fermentation process by different fungal isolates; F-66, F-94 and F-98 producing maximum total reducing sugars of 18.4., 26.1 and 20.4g/L, respectively.Separate biological hydrolysis and fermentation (SHF) process for bagasse was done by the two selected fungal isolates; Trichoderma viride F-94 and Aspergillus terreus F-98 and the two yeast isolates identified as Candida tropicalis Y-26 and Saccharomyces cerevisiae Y-39. SHF processes by F-94 and Y-26 produced 226kg of ethanol/ton bagasse while that of F-98 and Y-39 produced 185kg of ethanol/ton bagasse

Investigating the residual effect of silver nanoparticles gel as an intra-canal medicament on dental pulp stromal cells

Background The aim of this study was to evaluate the indirect effects of residual silver nanoparticles (AgNPs) gel on human dental pulp stromal cells (DPSCs). Methods Ninety-five dentin discs (4x4x1 mm) were prepared from freshly extracted human single-rooted teeth following institutional ethical approval and informed consent. Samples were cleaned, autoclaved, and treated with: 1.5%NaOCl, Saline and 17% EDTA then randomly assigned to 5 groups that received 50 μl of one of the following treatments: 0.01%AgNPs, 0.015%AgNPs, 0.02%AgNPs, Calcium hydroxide (Ca (OH)2) or no treatment for 1 week. Discs were washed with Saline and 17%EDTA then seeded with DPSCs and incubated for 3 and 7 days. At 24 hours unattached cells were collected and counted. At each time point cytotoxicity (LDH assay), cell viability (live/dead staining and confocal microscopy) and cell proliferation (WST1 assay) were assessed. All experiments were repeated a minimum of 3 times using DPSCs isolated from 3 different donors for each time point assessed (n = 9/group). Statistical analysis was done using One-Way ANOVA followed by Tukey’s test and Kruskal Wallis followed by post-hoc comparisons with significance set at p ≤ 0.05. Results After 24 hours, the percentage of DPSCs attachment ranged between 92.66% ±4.54 and 95.08% ±1.44 with no significant difference between groups (P = 0.126). Cell viability was ≥92% at 24 hours for all groups. However this percentage dropped to less than 60% at 3 days then started to rise again at 7 days. There was no significant difference in cytotoxicity between different groups at all time points except for 0.01%AgNPs group which had the highest cytotoxicity. DPSCs proliferation increased significantly from 3 to 7 days in all groups except for Ca (OH)2 which showed lower proliferation rates at both 3 (45.89%) and 7 days (79.25%). Conclusion Dentin discs treated for 7 days with concentrations of AgNPs gel (0.01–0.02%) allowed more than 90% DPSCs cell attachment after 24 hours. The cytotoxicity and proliferation of DPSCs in response to AgNPs gel were comparable to those with calcium hydroxide. This suggests that AgNPs gel may represent a promising future candidate for clinical use in regenerative endodontics. However, its effects may be concentration-dependent warranting further investigation

What the future holds for regenerative endodontics: novel antimicrobials and regenerative strategies

Regenerative/revitalisation endodontic techniques are increasingly used as a treatment approach for the management of immature permanent teeth with necrotic pulps. Different chemical irrigants and medicaments are routinely used clinically for intra-canal disinfection. However, despite remarkable progress in this field, coronal discolouration, cell cytotoxicity, difficulty of removal of organic biofilm from the root canal, development of sensitisation and antimicrobial resistance are still challenges to this line of treatment. This review critically discusses and challenges the current status quo of antimicrobials used in regenerative endodontics and sheds the light on future alternative antimicrobial materials with regenerative potential

Corrigendum: Insulin- like Growth Factor-Binding Protein Action in Bone Tissue: A Key Role for Pregnancy- Associated Plasma Protein-A

The insulin-like growth factor (IGF) axis is required for the differentiation, development, and maintenance of bone tissue. Accordingly, dysregulation of this axis is associated with various skeletal pathologies including growth abnormalities and compromised bone structure. It is becoming increasingly apparent that the action of the IGF axis must be viewed holistically taking into account not just the actions of the growth factors and receptors, but also the influence of soluble high affinity IGF binding proteins (IGFBPs). There is a recognition that IGFBPs exert IGF-dependent and IGF-independent effects in bone and other tissues and that an understanding of the mechanisms of action of IGFBPs and their regulation in the pericellular environment impact critically on tissue physiology. In this respect, a group of IGFBP proteinases (which may be considered as ancillary members of the IGF axis) play a crucial role in regulating IGFBP function. In this model, cleavage of IGFBPs by specific proteinases into fragments with lower affinity for growth factor(s) regulates the partition of IGFs between IGFBPs and cell surface IGF receptors. In this review, we examine the importance of IGFBP function in bone tissue with special emphasis on the role of pregnancy associated plasma protein-A (PAPP-A). We examine the function of PAPP-A primarily as an IGFBP-4 proteinase and present evidence that PAPP-A induced cleavage of IGFBP-4 is potentially a key regulatory step in bone metabolism. We also highlight some recent findings with regard to IGFBP-2 and IGFBP-5 (also PAPP-A substrates) function in bone tissue and briefly discuss the actions of the other three IGFBPs (-1, -3, and -6) in this tissue. Although our main focus will be in bone we will allude to IGFBP activity in other cells and tissues where appropriate

Breast Milk Macronutrients in Relation to Infants’ Anthropometric Measures

BACKGROUND: Breast milk (BM) is the main nutritional source for newborns before they are capable to eat and consume other foods. BM has carbohydrates, lipids, complex proteins, and other biologically active components which have a direct effect on infant growth. AIM: The aim of the study was to correlate anthropometric data of the infant to macronutrients in BM (fat, protein, and carbohydrates) and to find some modifiable issues affecting macronutrient contents of BM for the benefits of upcoming infants. METHODS: One hundred breastfeeding mothers participated in the study, they were recruited from the outpatient clinic, El Demerdash Hospital, Ain Shams University, from September 2019, to December 2019. BM was expressed by an electric pump, macronutrient content was assessed. Anthropometric data of the babies and mothers were obtained, gestational age, parity, age of the women, and the route of birth were recorded. RESULTS: For the macronutrients content of milk, a positive significant correlation was observed between BM fat, protein, and lactose. Infants’ body mass index (BMI) was negatively related to the fat content of BM, while no relation was found between BMI and protein or lactose content of the milk. BM fat content was negatively correlated with gestational age and maternal age. Positive correlations were found between BMI and protein, lactose and infant age. Protein content was negatively correlated with parity. No impact of infant’s sex on BM composition and as regards maternal diet, high protein consumption leading to increase BM protein content. CONCLUSIONS: The current study confirms that BM macronutrient composition has a wide variability; this variability is associated with each macronutrient, respectively. To improve BM composition, one could aim for improving the nutritional balance in lactating women, especially for protein intake. More well-designed longitudinal studies about factors that influence human milk compositions are warranted

Supramolecular macrocycles reversibly assembled by Te ⋯ O chalcogen bonding

Organic molecules with heavy main-group elements frequently form supramolecular links to electron-rich centres. One particular case of such interactions is halogen bonding. Most studies of this phenomenon have been concerned with either dimers or infinitely extended structures (polymers and lattices) but well-defined cyclic structures remain elusive. Here we present oligomeric aggregates of heterocycles that are linked by chalcogen-centered interactions and behave as genuine macrocyclic species. The molecules of 3-methyl-5-phenyl-1,2-tellurazole 2-oxide assemble a variety of supramolecular aggregates that includes cyclic tetramers and hexamers, as well as a helical polymer. In all these aggregates, the building blocks are connected by Te(…)O-N bridges. Nuclear magnetic resonance spectroscopic experiments demonstrate that the two types of annular aggregates are persistent in solution. These self-assembled structures form coordination complexes with transition-metal ions, act as fullerene receptors and host small molecules in a crystal

A bilayered tissue engineered in vitro model simulating the tooth periodontium

Due to the complexity of the structure of the tooth periodontium, regeneration of the full tooth attachment is not a trivial task. There is also a gap in models that can represent human tooth attachment in vitro and in vivo. Aim of the study: to develop a bilayered in vitro construct that simulates the tooth periodontium, for the purpose of tissue regeneration and investigation of physiologic and orthodontic loading. Methods: Two types of materials were used to develop this construct: Sol-Gel 60S10Mg scaffold (University of Erlangen) representing the hard tissue component of the and commercially available Geistlich Bio-Gide® collagen membrane representing the soft tissue component of the tooth attachment. Each scaffold was dynamically seeded with periodontal ligament cells. The seeded scaffolds were either cultured separately, or combined in a bilayered construct, for 2 weeks. Characterization of the individual scaffolds and the bilayered constructs included biological characterization: (cell viability, SEM imaging to confirm cell attachment and viability qRT-PCR expression for periodontium regeneration markers), and mechanical characterisation of scaffolds and constructs. Results: HPDLCs enjoyed a biocompatible 3D environment within the bi-layered construct components as demonstrated by live/dead images and LDH assay. Gene expression showed variation between individual scaffolds and constructs detached from the bilayer. Most genes showed a drop in expression in the construct except for markers of angiogenesis which showed their highest expression in Bio-Gide® detached constructs. Conclusion and clinical significance: the development of this model is important for physiologic simulation invitro and for tissue regeneration purposes of the tooth periodontium