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Biological nitrification inhibitors (BNIs) are released from plant roots as exudates to repress nitrifier activity in agricultural soils, and this can improve nitrogen (N) recovery from fertilizer and enhance the N-use-efficiency (NUE). This review summarizes the current understanding of the regulatory mechanisms of BNIs release from roots of plants, such as Brachiaria humidicola (pasture grasses), Sorghum bicolor (hybrid sorghum) and Oryza sativa (paddy rice). BNIs can be categorized as hydrophilic- and hydrophobic-BNIs. Root systems can rapidly release hydrophilic-BNIs when NH4+ is present in rhizosphere in combination with low pH, which is associated with the activation of plasma membrane H+-ATPase. Since plasma membrane H+-ATPase is responsible for the establishment of membrane potential and generation of proton motive force for the secondary transport of various substances. The BNIs release may probably occur through the voltage-gated anion channels by the membrane potential variation or via secondary transporters, most likely MATE transporters, powered by the proton motive force. In addition, ATP-binding cassette (ABC) transporters may be also involved in the active efflux of hydrophilic-BNIs. On the contrary, the release of the hydrophobic BNIs, such as sorgoleone, from plant roots may be mediated by the vesicle traffic process and/or exocytosis. In addition, the possible effects of various environmental factors on the BNIs release in soils have been discussed. Future research should focus on the identification of the corresponding BNIs transporters in plants, and this may be helpful for the application of BNI crops in the agricultural practice via breeding and genetic modification.

This study is a starting point for the development of an efficient method for rare earths (REs) and transition metals (TMs) recovery from waste electrical and electronic equipment (WEEE) via a hydrometallurgical process. The capture and release capability of mineral clays (STx) and activated carbons (AC), pristine and modified (STx-L6 and AC-L6) with a linear penta-ethylene-hexamine (L6), towards solutions representative of the process, are assessed in the lab-scale. The solids were contacted with synthetic mono- and bi-ionic solutions containing Ni(II) and La(III) in a liquid/solid adsorption process. Contacting experiments were carried out at room temperature for 90 min by fixing a La concentration at 19 mM and varying the Ni one in the range of 19–100 mM. The four solids were able to capture Ni(II) and La(III), both in single- and bi-ionic solutions; however, the presence of the polyamine always results in a large improvement in the capture capability of the pristine sorbents. For all the four solids, capture behaviour is ascribable to an adsorption or ion-sorbent interaction process, because no formation of aquo- and hydroxy-Ni or La can be formed. The polyamine, able to capture Ni ions via coordination, allowed to differentiate ion capture behaviour, thus bypassing the direct competition between Ni and La ions for the capture sites found in the pristine solids. Release values in the 30–100% range were found upon one-step treatment with concentrated HNO3 solution. However, also, in this case, different metals recovery was found depending on both the sorbent and the ions, suggesting a possible selective recovery.

In the current research drug release kinetics and transport mechanisms of doxorubicin (DOX) from DOX, DOX/valspodar (PSC 833) and DOX/ᴅ-α- tocopheryl polyethylene glycol 1000 succinate (TPGS 1000) loaded polymeric micelle (PM) delivery systems were studied. Mathematical modeling has shown that the best suitability for release at pH 5.0 medium (R2 > 0.98) is provided by Korsmeyer-Peppas model and drug release kinetics are both anomalous transport (non-Fickian) and Super case II transport. The drug release was considered to fits in both the Korsmeyer-Peppas and Weibull models for DOX release from DOX-PM, DOX/PSC 833-PM, DOX/TPGS 1000-PM at pH 6.5 and pH 7.4 medium.

Near drainage culverts located in the Apalachicola National Forest, and particularly within the New River (HUC8) sub-basin, and the State of Florida Waterbody IDs (WBID) 1034B boundary, water quality commonly fails to attain designated minimum criteria for iron within surface waters established in the Surface Water Quality Standards (62-302, FAC), and the Impaired Waters Rule (IWR, 62-303, FAC). Three iron release mechanisms, i.e., organic decomposition coupled with Fe(III) reduction (IRM I), iron-related mineral decomposition (IRM II), and elemental iron corrosion (IRM III) were identified and found to be responsible for ferrous iron release. The soil and water samples were collected from eleven culvert sites within the Apalachicola National Forest and analyzed. Various statistical methods were used to identify the correlation of iron release mechanisms with measured parameters. Using partial least square regression, four components were found to capture the variances that significantly contributed to the various iron concentration, among which P1 and P2 were the two dominating contributors and were associated with IRM I and IRM II. P3 accounted for 6.5% of the variance and was attributed to IRM III. Based on IRM II, ferrous iron was released from pyrite decomposition, which was correlated with elevated sulfate concentration in the water. The soil samples were analyzed together by X-ray powder diffraction (XRD) and X-ray fluorescence (XRF), further evidenced that sulfate-related mineral contributed to this process. For IRM I, the decomposition of organics releases electrons, which eventually reduces iron oxides to mobile ferrous iron. Corresponding to the organic decomposition, low dissolved oxygen (DO) was also observed. Although IRM III was found to be responsible for a smaller portion of iron release, it was deemed not to be the dominating mechanism of iron release.

Three laboratory-scale digesters were operated in parallel under anaerobic, anoxic and aerobic conditions to reveal the release mechanisms of phosphorus when digesting enhanced biological phosphorus removal (EBPR) sludge. The variation rates of the parameters associated with phosphorus release were calculated and compared with that of a typical EBPR anaerobic process. The results show that both phosphorus-accumulating organisms (PAOs) and denitrifying phosphorus-accumulating organisms (DPAOs) played important roles in the phosphorus release during the digestion processes. Under anaerobic conditions, the PAOs hydrolyzed internal polyphosphorus (poly-P) into PO43−-P concurrent with synthesis of polyhydroxyalkanoates (PHA). Under anoxic or aerobic conditions, PAOs and/or DPAOs assimilated part of the PO43−-P from the digestive liquid using nitrate or oxygen as terminal electron acceptors. Nevertheless, the biological activities of PAOs under anaerobic conditions and DPAOs under anoxic conditions were limited. Moreover, it was the biomass hydrolysis degree that determined the phosphorus release capacity of the sludge, regardless of whether anaerobic, anoxic or aerobic conditions were adopted. Assuming that nitrate was the sole electron acceptor during anoxic digestion of EBPR biomass, the relationship between the consumption of nitrate and uptake of PO43−-P associated with the denitrifying phosphorus removal (DPR) can be expressed as ΔP = 0.11 × ΔN.

The sustained release of pharmaceutical substances remains the most convenient way of drug delivery. Hence, a great variety of reports can be traced in the open literature associated with drug delivery systems (DDS). Specifically, the use of microparticle systems has received special attention during the past two decades. Polymeric microparticles (MPs) are acknowledged as very prevalent carriers toward an enhanced bio-distribution and bioavailability of both hydrophilic and lipophilic drug substances. Poly(lactic acid) (PLA), poly(lactic-co-glycolic acid) (PLGA), and their copolymers are among the most frequently used biodegradable polymers for encapsulated drugs. This review describes the current state-of-the-art research in the study of poly(lactic acid)/poly(lactic-co-glycolic acid) microparticles and PLA-copolymers with other aliphatic acids as drug delivery devices for increasing the efficiency of drug delivery, enhancing the release profile, and drug targeting of active pharmaceutical ingredients (API). Potential advances in generics and the constant discovery of therapeutic peptides will hopefully promote the success of microsphere technology.

Recent developments in micro and nanoencapsulation are promising tools to encounter the different limitations of essential oil formulations, enhance their functionalities, and protect them from the external environmental conditions. This review addresses the current studies and progresses related to the development of encapsulated essential oils using different systems and carrier material types. It also focuses on the formation methods used with the subsequent physicochemical characterization of the developed particles. Moreover, this review considers the factors affecting the release of essential oils with the different physicochemical release models. The choice of the appropriate formation method as well as the carrier material types and system forms were shown to highly depend on the intended purpose of the encapsulated essential oil formulation. Micro and nanoencapsulation are used to control essential oils’ release properties, enhance the various characteristics of essential oils, and allow to expand applications in different fields. This review provides the optimal conditions for micro and nanoencapsulation of essential oil formulations based on the intended end uses.

Improving the safety efficacy ratio of existing drugs is a current challenge to be addressed rather than the development of novel drugs which involve much expense and time. The efficacy of drugs is affected by a number of factors such as their low aqueous solubility, unequal absorption along the gastrointestinal (GI) tract, risk of degradation in the acidic milieu of the stomach, low permeation of the drugs in the upper GI tract, systematic side effects, etc. This review aims to enlighten readers on the role of pH sensitive hydrogels in drug delivery, their mechanism of action, swelling, and drug release as a function of pH change along the GI tract. The basis for the selection of materials, their structural features, physical and chemical properties, the presence of ionic pendant groups, and the influence of their pKa and pKb values on the ionization, consequent swelling, and targeted drug release are also highlighted.

The slow/controlled release technology is effective in enhancing the utilization of pesticide and reducing the environment pollution caused by pesticide. In this study, the slow/controlled release carboxymethyl chitosan films were prepared by film casting method, and the pesticide release properties were investigated. The results showed that the pesticide-loaded carboxymethyl chitosan films were smooth and uniform. Different pesticide-loaded films had different film thicknesses, pesticide loading and encapsulation efficiency, but had the same pesticide release trend, which might be the result of multiple pesticide release mechanisms including the swelling and erosion of the carboxymethyl chitosan. This study would promote the application of slow/controlled release technologies in pesticides and accelerate the green and efficient development of agriculture.

Thermosensitive hydrogels, having unique sol–gel transition properties, have recently received special research attention. These hydrogels exhibit a phase transition near body temperature. This feature is the key to their applications in human medicine. In addition, hydrogels can quickly gel at the application site with simple temperature stimulation and without additional organic solvents, cross-linking agents, or external equipment, and the loaded drugs can be retained locally to improve the local drug concentration and avoid unexpected toxicity or side effects caused by systemic administration. All of these features have led to thermosensitive hydrogels being some of the most promising and practical drug delivery systems. In this paper, we review thermosensitive hydrogel materials with biomedical application potential, including natural and synthetic materials. We describe their structural characteristics and gelation mechanism and briefly summarize the mechanism of drug release from thermosensitive hydrogels. Our focus in this review was to summarize the application of thermosensitive hydrogels in disease treatment, including the postoperative recurrence of tumors, the delivery of vaccines, the prevention of postoperative adhesions, the treatment of nervous system diseases via nasal brain targeting, wound healing, and osteoarthritis treatment.