Modelling and Control of Corticotropin Permeation from Hydrogels across a Natural Membrane in the Presence of Albumin

(1) Background: Skin is a difficult barrier to overcome, especially for molecules with masses greater than 500 Da. It has been suggested that albumin may contribute to more effective penetration of many therapeutic substances. In this study, an attempt was made to use albumin in semi-solid formulations to increase the skin penetration of another peptide—corticotropin (ACTH). (2) Methods: Hydrogels were prepared at two concentrations: 15 mg/g and 20 mg/g corticotropin, then albumin was added to them in different stoichiometric ratios. The degree of ACTH release from hydrogels, both with and without albumin addition, was investigated. For selected hydrogels the process of corticotropin permeation through a model membrane, i.e., pig skin, was examined. (3) Results: The study of corticotropin release showed that the addition of albumin, depending on its amount, may delay or increase the release process. Similarly, a study of ACTH permeation through porcine skin showed that albumin can delay or increase and accelerate ACTH permeation. (4) Conclusions: Hydrogel, applicated on the skin surface, may prove to be a beneficial and convenient solution for patients. It is an innovative way of application ACTH that bypasses the gastrointestinal tract and may result in increased availability of the peptide and its efficacy.

Integration of green nanotechnology with silica for corrosion inhibition

Silica is a chemically inert molecule with an ability of adsorption on the metal to form a layer of barrier for preventing it from the atmospheric damage. However, a larger amount of silica is required for producing the impactful anticorrosive activity, leading to toxic and carcinogenic effects in the environment, and thus limiting the applications of silica. Application of nanotechnology in the synthesis of silica nanocomposites provides, for example, the advantages of better biocompatibility, systemic stability, ineffective response towards pH changes large multifunctionality. However, uses of harmful solvent, low penetration and toxicity, remain the major concerns for silica nanoparticles. Synthesis of silica nanocomposites with green technology will be an attractive approach to offer reduction in toxicity associated with the silica, higher surface area, effective penetration, easy spreadability, better adsorption over the metal surface and also provided the controlled release of chemical agents on contact with metal surface. The present article enlightens the use of green syntheses in the formulation of silica nanocomposites for corrosion inhibition in comparison to conventional synthetic method and provides the insights of various green nanocarriers such as nanocontainers, sol-to-gel nanoparticles, metallic nanostructures and silica nanocomposites for enhancing the proficiency of corrosion inhibition.

Fractional Current Flow in the Subsurface Using Electrical Resistivity Method: A Laboratory Approach

The authors describe electrical resistivity method using a laboratory experiment, which was conducted in order to calculate the percentage of current that penetrated each layer of soil arranged in a container using Schlumberger array. Four soil samples arranged in three different set-ups were used. The apparent resistivity obtained was interpreted using curve matching techniques and WinResist iteration yielding types A curve, H curve and A curve, respectively. The interpreted data gave the resistivity of each layer and its thicknesses. The thicknesses obtained from the interpretation were at variance with the actual thicknesses arranged in the container. A multiplier was obtained which serves as a constant in other to obtain the actual thickness. The effective penetration depth of current was determined through the calculated thickness of each layer and the known electrode spacing (AB). The percentage of current that penetrates the layers was found to depend on the electrode spacing as well as the thickness of that layer. Thus, a layer with relatively small thickness has a small percentage of current passing through it compared to a thicker layer.

Evaluating the efficiency of using different variants of background models for inversion calculations

The use of the method of seismic data acoustic inversion, in the presence of thick gas cap, can lead to difficulties when building background models of elastic parameters. In this regard, in the conditions of acoustically contrast thin environments within the perimeter of the Russkoye oil and gas condensate field, in addition to the standard version based on the well data, the authors considered a number of modified techniques ("block", "flat", and background models). The use of these background models provided the best results and made it possible to significantly improve the quality of predicting rock properties; based on the drilling results, effective penetration was ensured at 66 %, which was 102 % of the plan. Also, based on the inversion results, it became possible to predict reservoir properties using the Bayesian lithotype classification method.

Experimental and Theoretical Determination of the Effective Penetration Depth of Ultrafast Laser Radiation in Stainless Steel

This study intends to present a simple two-temperature model (TTM) for the fast calculation of the ablation depth as well as the corresponding effective penetration depth for stainless steel by considering temperature-dependent material parameters. The model is validated by a comparison of the calculated to the experimentally determined ablation depth and the corresponding effective penetration depth in dependence on the pulse duration (200 fs up to 10 ps) and the fluence. The TTM enables to consider the interaction of pulsed laser radiation with the electron system and the subsequent interaction of the electrons with the phonon system. The theoretical results fit very well to the experimental results and enable the understanding of the dependence of the ablation depth and of the effective penetration depth on the pulse duration. Laser radiation with a pulse duration in the femtosecond regime results in larger ablation depths compared to longer-pulsed laser radiation in the picosecond regime. Analogously to the ablation depth, larger effective penetration depths are observed due to considerably higher electron temperatures for laser radiation with pulse durations in the femtosecond regime.

Ground Penetrating Radar Attenuation Expressions in Shallow Groundwater Research

The electromagnetic-wave attenuation coefficient determines the overall resolution and effective penetration depth of ground penetrating radar (GPR) surveys. Despite this relevance to the design of proper GPR surveys, the attenuation expressions are rarely used in the applied shallow groundwater research (SGR) literature. This work examines the status of the attenuation expressions in SGR. For this, 73 GPR case studies (in 47 papers), including some information concerning the attenuation variables and parameters, were selected to build a database. From these, 18 cases (in 10 papers) provided attenuation expressions and only 11 cases (in 4 papers) used those expressions. Two types of expressions were identified, physically based global ones that try to solve a broad (but not complete) range of environmental and field technical conditions, and non-global ones adapted for specific geological environments and resolution needed. The database analysis showed that both global and non-global expressions were used exclusively in low-loss media to report an attenuation range of 0.1–21.5 dB m −1 by using common antenna frequencies in the 25–900 MHz range. The range of the attenuation expressions validity in SGR is biased because no surveys in variable-loss heterogeneous media and wider antenna frequency intervals could be compiled. The attenuation database generated seeks to improve the design of GPR surveys in SGR.

Hybrid mesoporous nanorods with deeply grooved lateral faces toward cytosolic drug delivery

Hybrid mesoporous nanorods with six twisted sharp edges can induce effective penetration of intracellular barriers and cytosolic delivery of membrane-impermeable drugs through curvature effects.