Use of Nanoparticles for Environmental Remediation

Continuous release of contaminants into the environment and their toxic effects on the living world prompted public and scientific interests in the remediation of pollutants. The release of toxic pollutants not only hinders the soil environments but also disturbs the aquatic environments. The hindrance in soil and aquatic environments causes a serious warning to the productive environment and food security. Thus, excluding and counteracting the pollutants from the environment is necessary to develop a safe and productive environment. Currently, numerous techniques are used to remediate contaminants from the environment; moreover, nanoparticles are one of such most widely used techniques for environmental clean-up. This chapter briefly discusses the need for environmental remediation and nanoparticles for environmental clean-up, especially soil and water. Additionally, the complications and current research trends of using nanoparticles in environmental remediation are briefly discussed for determining future research prospects.

Calculation of crosswind integrated concentration by using different dispersion schemes

The Gaussian model is the most extensively used model for local dispersion. The Gaussian formula for a continuous release from a point source (GPM) is integrated to get crosswind integrated concentration. Different schemes such as Irwin, power law, Briggs, Standard method, and split sigma theta method can be used to obtain integrated concentration. Also downwind speed in power law, plume rise and Statistical measures are used in the model to know which is the best scheme agrees with the observed concentration data obtained from Copenhagen, Denmark.

Multi-point Sources Continuous Release Inversion Based on Improved Four-Dimensional Variation Method

the continuous release of multi-point sources is one of the most common cases in the field of air pollution. In order to solve the problem of multi-point sources continuous release inversion, a source intensity and location estimation method based on improved Four-Dimensional Variation is proposed. Firstly, by constructing the diffusion equation of multi-point sources continuous release and the monitoring concentration matrix, the source term inversion model of multi-point sources continuous release is formed. Secondly, the joint transformation method and Taylor series upwind difference method are used to solve the convection-diffusion equation of multi-point sources continuous release, and the numerical solution format of the forward problem is formed through simulation analysis. Furthermore, based on the numerical solution scheme of the forward problem, a four-dimensional variation inversion algorithm for multi-point sources continuous release is constructed, and the flower pollination algorithm is used to improve the inversion accuracy and computational efficiency. Finally, the applicability, feasibility, advantages and disadvantages of the improved four-dimensional variation algorithm are verified by numerical simulation analysis. It is found that the improved four-dimensional variation algorithm can realize the source term inversion under three conditions: the location is known and the intensity is unknown, the intensity is known and the location is unknown, the intensity and the location are all unknown, which the accuracy and computational efficiency can basically meet the actual needs.

Increasing the Transport of Celecoxib over a Simulated Intestine Cell Membrane Model Using Mesoporous Magnesium Carbonate

In the current work, mesoporous magnesium carbonate (MMC) was used to suppress crystallization of the poorly soluble drug celecoxib (CXB). This resulted in both a higher dissolution rate and supersaturation of the substance in vitro as well as an increased transfer of CXB over a Caco-2 cell membrane mimicking the membrane in the small intestine. The CXB flux over the cell membrane showed a linear behavior over the explored time period. These results indicate that MMC may be helpful in increasing the bioavailability and obtaining a continuous release of CXB, and similar substances, in vivo. Neusilin US2 was used as a reference material and showed a more rapid initial release with subsequent crystallization of the incorporated CXB in the release media. The presented results form the foundation of future development of MMC as a potential carrier for poorly soluble drugs.

Why are US military personnel prescribed transdermal fentanyl patches?

IntroductionTransdermal fentanyl is a continuous release opioid delivery system intended for use in opioid-tolerant patients requiring around-the-clock opioid therapy. The purpose of this study is to identify the most common indications for transdermal fentanyl prescriptions in active duty US military personnel, and determine whether these prescriptions meet US Food and Drug Administration (FDA) labelling.MethodsActive duty US military personnel initiating transdermal fentanyl therapy with prescriptions filled at Military Health System pharmacies between 2015 and 2019 were identified in the Military Data Repository. Electronic health records were searched for patient demographic information, clinical information and prescription data. A total of 225 patients with complete data were identified.ResultsThe most common reason for transdermal fentanyl initiation was chronic non-cancer musculoskeletal pain. Among patients with non-cancer pain, 36% received their initial prescription from an internal medicine/primary care provider, and 35% did not meet published US FDA criteria for opioid tolerance prior to treatment initiation. There was an 81% decrease in patients initiating therapy between 2015 and 2019.ConclusionsWhile a substantial minority of transdermal fentanyl prescriptions to US military personnel did not meet FDA guidelines on appropriate use, the overall number of prescriptions fell dramatically over the study period. This suggests that automated profile review or additional targeted policies to limit transdermal fentanyl prescribing are unnecessary at this time.

Thermo-sensitive electroactive hydrogel combined with electrical stimulation for repair of spinal cord injury

The strategy of using a combination of scaffold-based physical and biochemical cues to repair spinal cord injury (SCI) has shown promising results. However, integrating conductivity and neurotrophins into a scaffold that recreates the electrophysiologic and nutritional microenvironment of the spinal cord (SC) remains challenging. In this study we investigated the therapeutic potential of a soft thermo-sensitive polymer electroactive hydrogel (TPEH) loaded with nerve growth factor (NGF) combined with functional electrical stimulation (ES) for the treatment of SCI. The developed hydrogel exhibits outstanding electrical conductance upon ES, with continuous release of NGF for at least 24 days. In cultured nerve cells, TPEH loaded with NGF promoted the neuronal differentiation of neural stem cells and axonal growth, an effect that was potentiated by ES. In a rat model of SCI, TPEH combined with NGF and ES stimulated endogenous neurogenesis and improved motor function. These results indicate that the TPEH scaffold that combines ES and biochemical cues can effectively promote SC tissue repair.

Effects of Metformin on Reproductive, Endocrine, and Metabolic Characteristics of Female Offspring in a Rat Model of Letrozole-Induced Polycystic Ovarian Syndrome With Insulin Resistance

The beneficial effects of metformin, especially its capacity to ameliorate insulin resistance (IR) in polycystic ovary syndrome (PCOS), explains why it is widely prescribed. However, its effect on the offspring of patients with PCOS remains uncertain. This study investigated the impact of metformin treatment on the first- and second-generation female offspring born to letrozole-induced PCOS-IR rats. Forty-five female Wistar rats were implanted with continuous-release letrozole pellets or placebo and treated with metformin or vehicle control. Rats exposed to letrozole showed PCOS-like reproductive, endocrine, and metabolic phenotypes in contrast to the controls. Metformin significantly decreased the risk of body weight gain and increased INSR expression in F1 female offspring in PCOS-IR rats, contributing to the improvement in obesity, hyperinsulinemia, and IR. Decreased FSHR expression and increased LHCGR expression were observed in F1 female rats of the PCOS-IR and PCOS-IR+Metformin groups, suggesting that FSHR and LHCGR dysfunction might promote the development of PCOS. Nevertheless, we found no significant differences in INSR, FSHR, and LHCGR expression or other PCOS phenotypes in F2 female offspring of PCOS-IR rats. These findings indicated widespread reproductive, endocrine, and metabolic changes in the PCOS-IR rat model, but the PCOS phenotypes could not be stably inherited by the next generations. Metformin might have contributed to the improvement in obesity, hyperinsulinemia, and IR in F1 female offspring. The results of this study could be used as a theoretical basis in support of using metformin in the treatment of PCOS-IR patients.

Thermo-Sensitive Electroactive Hydrogel Combined With Electrical Stimulation For Repair of Spinal Cord Injury

The strategy of using a combination of scaffold-based physical and biochemical cues to repair spinal cord injury (SCI) has shown promising results. However, integrating conductivity and neurotrophins into a scaffold that recreates the electrophysiologic and nutritional microenvironment of the spinal cord (SC) remains challenging. In this study we investigated the therapeutic potential of a soft thermo-sensitive polymer electroactive hydrogel (TPEH) loaded with nerve growth factor (NGF) combined with functional electrical stimulation (ES) for the treatment of SCI. The developed hydrogel exhibits outstanding electrical conductance upon ES, with continuous release of NGF for at least 24 days. In cultured nerve cells, TPEH loaded with NGF promoted the neuronal differentiation of neural stem cells and axonal growth, an effect that was potentiated by ES. In a rat model of SCI, TPEH combined with NGF and ES stimulated endogenous neurogenesis and improved motor function. These results indicate that the TPEH scaffold that combines ES and biochemical cues can effectively promote SC tissue repair.

Microglia NLRP3 Inflammasomes Activation Involving Diabetic Neuroinflammation in Diabetic Mice and BV2 Cells

Background: Hyperglycemia-induced microglia activation can cause a continuous release of proinflammatory cytokines, which gradually damages neurons and contributes to central diabetic neuroinflammation. Objective: This study aimed to illustrate the possible mechanism related to NLRP3 inflammasome and the aggravation of diabetes neuroinflammation. Methods: The targeted proteins from BV2 cells and brain tissues were tested by Western blot or immunohistochemistry. Cytokines from cell supernatant and serum were detected by ELISA. Meanwhile, cytoplasm and mitochondria ROS were determined by DCFHDA and Mito sox Red, respectively. Results: In vitro, BV2 cells were stimulated by different glucose concentrations (5.5 to 65 mM/L) above physiological values and maintained for different periods (12 to 48h). The proinflammatory cytokines IL-1β，IL18，IL6，TNFα and cytoplasm ROS were significantly increased in a dose-dependent manner, while mitochondrial ROS was unaffected. NLRP3 inflammasomes, MAPKs, and NF-κB pathways were obviously activated at the concentration of 35 mM/L for 12h. Inhibition assay using specific inhibitors indicated that the treatment of glucose (35 mM/L for 12h) could stimulate NLRP3 inflammasome activation via ROS/JNK MAPKs/NF-κB pathway. In STZ induced diabetes mice models, microglia NLRP3, ASC, and caspase-1 proteins were highly expressed, and serum cytokines IL-1β, IL6, IL18, and TNFα were remarkably increased. Conclusion: Microglia NLRP3 inflammasomes activation involves diabetic neuroinflammation in diabetic mice and BV2 cells via ROS/JNK MAPKs/NF-κB pathways.