Conventional superelastic orthodontic wires are arch-shaped, have the same mechanical properties all along their length and are used to correct the position of teeth. The disadvantage of these ...archwires is that there are different types of teeth in the mouth and different forces are therefore needed to rectify their position. The aim of this work was to laser weld several types of NiTi orthodontic wires that had different chemical compositions and superelastic properties, in order to adjust their properties to different parts of the mouth. Microstructural changes, transformation stresses and temperatures, variations in corrosion behaviour and ion release were studied in the welded wires.
A set of forty-one surface sediment samples were collected in River Pánuco and its adjoining lagoon areas in NE Mexico to identify the enrichment pattern of trace elements. The samples were analyzed ...for sediment texture, carbonates, organic carbon and acid leachable trace elements (ALTEs) using autoclave method Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn, Cd, V, Be, Ba, Sr, As. Geochemical results of Fe, Cr, Ni, Co, V and Sr in zone 1 indicate that erosion in the upland region (Sierra Madre Oriental Mountains) is very high. The above feature is supported by the supremacy of finer sediments (82.12 %), carbonates (44.67 %) and organic carbon (10.74 %), which are brought down from the drainage basin. The overall average concentration of ALTEs Mn (607 μg g⁻¹), Cu (28.29 μg g⁻¹), Ni (16.56 μg g⁻¹), Pb (46.11 μg g⁻¹), Cd (1.81 μg g⁻¹) and Zn (92.18 μg g⁻¹) indicates higher values than the lowest effect level (LEL) and effects range low (ERL) of environmental indicators. The results suggest that they are due to the increase in oil refineries, metal based industries, shipping activities and the effluent input which could enter the biological cycle and might create human health problems.
The impenetrability of the blood–brain barrier (BBB) to most conventional drugs impedes the treatment of central nervous system (CNS) disorders. Interventions for diseases like brain cancer, ...neurodegeneration, or age-associated inflammatory processes require varied approaches to CNS drug delivery. Cystine-dense peptides (CDPs) have drawn recent interest as drugs or drug-delivery vehicles. Found throughout the phylogenetic tree, often in drug-like roles, their size, stability, and protein interaction capabilities make CDPs an attractive mid-size biologic scaffold to complement conventional antibody-based drugs. Here, we describe the identification, maturation, characterization, and utilization of a CDP that binds to the transferrin receptor (TfR), a native receptor and BBB transporter for the iron chaperone transferrin. We developed variants with varying binding affinities (KD as low as 216 pM), co-crystallized it with the receptor, and confirmed murine cross-reactivity. It accumulates in the mouse CNS at ~25% of blood levels (CNS blood content is only ~1%–6%) and delivers neurotensin, an otherwise non-BBB-penetrant neuropeptide, at levels capable of modulating CREB signaling in the mouse brain. Our work highlights the utility of CDPs as a diverse, easy-to-screen scaffold family worthy of inclusion in modern drug discovery strategies, demonstrated by the discovery of a candidate CNS drug delivery vehicle ready for further optimization and preclinical development.
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•Blood–brain barrier penetration is key to treating central nervous system diseases.•A drug-like cystine-dense peptide that binds transferrin receptor was identified.•Brain accumulation and pharmacodynamic effect of peptide cargo were seen.•This peptide represents a small (5 kDa) tag permitting CNS delivery of therapeutics.
We give a self-contained treatment of symmetric Banach sequence spaces and some of their natural properties. We are particularly interested in the symmetry of the norm and the existence of symmetric ...linear functionals. Many of the presented results are known or commonly accepted, but are not found in the literature.
Many diseases are mediated by targets that are not amenable to conventional small-molecule drug approaches. While antibody-based drugs have undeniable utility, peptides of the 1-9 kDa size range ...(10-80 amino acids) have drawn interest as alternate drug scaffolds This is born of a desire to identify compounds with the advantages of antibody-based therapeutics (affinity, potency, specificity, and ability to disrupt protein:protein interactions) without all of their liabilities (large size, expensive manufacturing, and necessity of humanization). Of these alternate scaffolds, cystine-dense peptides (CDPs) have several specific benefits. Due to their stable intra-chain disulfide bridges, CDPs often demonstrate resistance to heat and proteolysis, along with low immunogenicity. These properties do not require chemical modifications, permitting CDP screening by conventional genetic means. The cystine topology of a typical CDP requires an oxidative environment, and we have found that the mammalian secretory pathway is most effective at allowing diverse CDPs to achieve a stable fold. As such, high-diversity screens to identify CDPs that interact with targets of interest can be efficiently conducted using mammalian surface display. In this protocol, we present the theory and tools to conduct a mammalian surface display screen for CDPs that bind with targets of interest, including the steps to validate binding and mature the affinity of preliminary candidates. With these methods, CDPs of all kinds can be brought to bear against targets that would benefit from a peptide-based intervention.
Buenfil-López, L.A.; Rebollar-Plata, M.; Muñoz-Sevilla, N.P., and Juárez-León, B., 2012. Sea-level rise and subsidence uplift processes in the Mexican South Pacific coast. Along the Mexican South ...Pacific coast, seismic activity can generate a relative and instantaneous fall in sea-level with differential recovery times along the coast that, considering the occurrence of new coseismic coastal uplifts, can induce recurrent hydrodynamic behaviors. These behaviors could be important for coastal processes, such as tide inlet stability or beach erosion and accretion rates. To obtain a first approximation of this phenomenon, four tide gauge records were analyzed. Results showed a relative fall in sea-level at two tide gauge stations: Acapulco (25.3 cm) and Puerto Angel (14.6 cm). By applying derived sea-level trends, it was observed that the needed time to recover the mean sea level before the events occurred was 25.1 y for Acapulco and 82.9 y for Puerto Angel. If the apparent increment of global sea-level trends obtained from satellite altimetry is considered, recovery times could be reduced by 3.1 and 36.9 y for Acapulco and Puerto Angel, respectively. In Puerto Angel, this implies a significant reduction in the probability of the occurrence of a new coseismic uplift before the recovery of mean sea level. To make generalizations for the Mexican South Pacific coast, an auxiliary tool, the Recurrent Hydrodynamic Behavior Graph, was developed to facilitate analysis of the phenomenon and assist with decision making in coastal projects.
Invasive meningococcal disease, an uncommon but severe disease, imposes catastrophic health and economic burdens. Cost-utility analysis (CUA) assumes separability in lifetime health and economic ...variables and cannot capture the full value of preventing such burdens. We overcome these limitations with a retrospective societal perspective cost-benefit analysis (CBA) of meningococcal serogroup B vaccination (4CMenB) of one infant cohort in the United Kingdom using a health-augmented lifecycle model (HALM) incorporating health's interactions with consumption, earnings, non-market time and financial risk.
We used a static Markov model of vaccination's health impact and an HALM to estimate the private willingness to pay (PWTP) for the intrinsic and instrumental value of health under perfect capital markets, financial risk protection in the absence of insurance against permanent disability, parental spillovers, and acute phase disability. We estimated social WTP (SWTP) incorporating social severity preferences. We estimated rates of return that inform health payer reimbursement decisions, finance ministry budgeting decisions, and legislature taxation decisions. An expert Advisory Board investigated the validity of applying the HALM to infant 4CMenB.
The PWTP for a 2 + 1 vaccination schedule is £395, comprising £166 of disability insurance value, £79 of positive parental spillover value, £28 in the value of averting acute phase disability, and £122 in residual intrinsic and instrumental value of health. SWTP is £969.
HALM-based CBA provides an empirically richer, more utility-theoretically grounded approach to vaccine evaluation than CUA, demonstrating good value for money for legislatures (based on private values) and for all decision-makers (based on social values).
Activated carbon (AC) was obtained from the dry endocarp of coffee for the manufacture of electrodes for supercapacitors. Four different AC samples were prepared via chemical methods at different ...proportions of impregnation (Xp) and two temperatures of activation (600 and 700 °C). Scanning Electron Microscopy technology and the measurement of the adsorption of N
2
via the Brunauer–Emmett–Teller (BET) method were used to identify the morphological characteristics of AC, revealing high surface areas. Energy dispersive X-ray spectroscopy and Fourier-transform infrared spectroscopy techniques were applied for chemical composition analysis, identifying oxygenated functional groups which contribute to the increase in capacitance. The supercapacitor comprised two electrodes mounted on a tantalum cell, which was electrochemically evaluated by means of cyclic voltammetry and galvanostatic chronopotentiometry charge/discharge measurements. The maximum specific capacitance encountered was 186 Fg
−1
, which was obtained from the AC sample with a surface area of 734 m
2
g
−1
and prepared at an Xp of 150% and an activation temperature of 700 °C. All AC samples exhibited good electrochemical performance.
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•A DFT study reveals the feasibility to obtain biodiesel via a gold catalyst.•Triacetin is used a model of triglycerides to reduce computational time.•The triacetin ...transesterification is achieved by a van der Waals-driven attraction.•Despite its nobility, Au is capable of catalyzing reactions that produce biofuels.
A Density Functional study predicting a heterogeneous-catalyzed reaction to obtain biodiesel was performed. Triacetin simulated triglycerides in the presence of an Au(111) surface as the heterogeneous catalyst. Methoxy was implemented as alcohol solvent to understand the reaction trajectory along a three-step transesterification process. Reactants and products in the three-step process are adsorbed on the Au substrate through non-covalent interactions of the electrostatic-type, which are also mediated by a van der Waals attraction. Density of states indicated that the electronic structure nature of Au is preserved after the interaction with the organic moieties. This may be addressed to an enhanced stability of the Au(111) catalyst through the overall reaction. Charge transfer analysis revealed that the Au surface oxidation aids in the transesterification of triacetin and evidences that gold plays an important role in this catalytic process. Such results may provide fundamental insights into the design of heterogeneous catalysts for biodiesel production.
The coast of Oaxaca, along the southern Mexican Pacific coastline, is home to diverse ecosystems, which undergoes significant erosion and accretion due to natural and anthropogenic influences. This ...study aims in analysing the historical shoreline variations and predicting the future changes for better coastal management plans. In order to study the long-term variations in shoreline, Landsat time-series satellite imageries between 1973 and 2020 were evaluated. Overall, the results indicate that the coast is highly dominated by accretion (74%) process, with the most significant changes occurring at the estuarine areas and beaches. Linear Regression Rate (LRR) and Weighted Linear Regression (WLR) methods showed mean variations at rates of 1.2±2.5 and 0.4±2.5 m/yr for the long-term period. The analysis of seven short-term periods (for every 5 years between 1986–2020) identified the maximum mean erosion of −20.6 m during 2005–2010 and accretion of 18.7 m during 2000–2005. However, the forecasted rate of change for the period 2030 and 2040 using End Point Rate (EPR) statistics revealed that the northern region would continue to move seaward at a rate of +0.26 m/yr and the coastline of southern region would move landward at a possible rate of −0.45 m/yr. The natural factors such as rainfall, river discharge, hurricane, and wave dynamics are the main drivers of shoreline changes along the estuarine and wetland areas. Contrarily, the anthropogenic factors such as breakwaters and urbanization are responsible for coastline dynamics along the beaches and ports. Henceforth, the estuarine region, lagoon openings, and tourist beaches require utmost attention as the sediment flow in these regions are not monitored constantly.
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•Rate of erosion/accretion has been examined along the entire coast of Oaxaca using DSAS.•Evaluation of Short and Long-term shoreline evolution during 1973–2020.•Oceanographic and physiographic settings play a vital role in shoreline dynamics.•Chronic accretion has been observed in the study area.
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