Low Absorption Rate Research Articles

Construction of a Novel Barium‐Free Green‐Light Emitting Illuminant Based on Boron Carbide

AbstractGreen‐light emitting illuminant and green pearls that are currently being used for pyrotechnics are mainly composed of barium carbonate and polyvinyl chloride (PVC), which lead inevitably to the substantial generation of abundant harmful products for environmental pollution. There is thus considerable scope for the development of a novel emitting illuminant with an improved “green” composition instead of compositions incorporating barium based oxidants and polyvinyl chloride for environmental protection. For this purpose, a new composition composed of boron carbide, potassium perchlorate, and guanidine nitrate with a suitable burning rate of 5∼15 mm/s required for fireworks, the high luminous intensity of 34665 Cd and spectral purity of 67.1 % at a primary wavelength of 562 nm was developed. Notably, PM10 data demonstrated that the new composition generated less than half the amount of the smoke relative to the original one. More importantly, all of the safety parameters of this new formulation meet well with the standards’ requirements, i. e., a remarkable low sensitivity to friction (0 %) and impact (8 %), relative stability to electric discharge (374.4 mJ), flame (14.0 cm) and heating (unburned, unexploded at 75 °C for 48 h), as well as a high ignition temperature of 504.0 °C and a low moisture absorption rate (0.66 %). Taken together, the new emitting illuminant developed herein showed great potential to be used for fireworks and signal flare in both military and civilian applications.

Micro and Nanoencapsulation of Natural Colors: a Holistic View.

The applications of natural plant pigments are growing rapidly with the increasing awareness of the negative health impacts of synthetic colorants. Additionally, natural pigments possess various biological properties and therapeutic activities. But their functions are hindered by their poor bioavailability, bioaccessibility, low absorption rate, and susceptibility to destructive environmental changes during processing and delivery. Encapsulation is a method of entrapment of bioactive ingredients within suitable carriers to provide protection and for the appropriate delivery into the targeted site by the formation of particles or capsules in micrometer or nanometer scales. Encapsulation imparts several benefits including improved thermal and chemical stability, preserves or masks flavor, taste, or aroma, controlled and targeted release, and enhanced bioavailability of pigments. Micro and nanoencapsulation of pigments will provide extensive and intensive platforms for the development of a new stage in the production of novel and healthy foods. This review mainly focuses on the advanced developments in the fields of micro and nanoencapsulation of pigments.

Physical, chemical, and biological characterization of ginsenoside F1 incorporated in nanostructured lipid carrier.

This study was aimed to determine the physical property and thermodynamic stability of nanostructured lipid carrier suspension incorporating ginsenoside F1 (GF1_NLC), and to evaluate its transport and antioxidant properties. GF1_NLC suspension possessed spherical particles with an average size of 98.9nm, and the encapsulation efficiency reached approximately 90%. There was a good compatibility between ginsenoside F1 (GF1) and the nanostructured lipid carrier (NLC) formulation, giving no contribution to the changes in the structural organization and crystallization behavior of lipid particles. However, the incorporation of GF1 reduced the thermodynamic stability of the lipid particles. The permeability of GF1_NLC (39.2%) across Caco-2 cell monolayer was higher than that of free GF1 (26.0%); however, no significant differences were observed in the radical scavenging activity (84.1% and 85.5%, respectively). In conclusion, NLC could be a potential candidate for the delivery of GF1 into the living body due to its small particle size, high encapsulation efficiency, and improved permeability. PRACTICAL APPLICATIONS: Poor water solubility in an aqueous solution and low absorption rate of ginsenoside F1 in the intestinal track limit its practical application in food systems. In this study, ginsenoside F1 was encapsulated in nanostructured lipid carrier to enhance its water solubility and absorption rate. The results of the encapsulated ginsenoside F1 showed high encapsulation efficiency of 90% with fine particle size of 98.9nm that could correspond to the enhancement of water solubility in an aqueous solution and permeability across Caco-2 cell monolayer. The results may encourage the food industry to utilize this encapsulation technique for the enhancement of the functional properties of poorly water-soluble bioactive compounds.

Performance of Ti6Al4V fabricated by electron beam and laser hybrid preheating and selective melting strategy

Electron beam selective melting (EBM) and selective laser melting (SLM) are regarded as significant manufacturing processes for near-net-shaped Ti6Al4V components. Generally, in the conventional EBM process, preheating is necessitated to avoid “smoke” caused by the charging of electrons. In the conventional SLM process, laser as an energy source without the risk of “smoke” can be employed to melt metal powder at low temperatures. However, because of the low absorption rate of laser, the powder bed temperature cannot reach a high level. It is difficult to obtain as-built TiAl4V with favorable comprehensive properties via conventional EBM or SLM. Hence, two types of electron beam and laser hybrid preheating (EB-LHP) combined with selective melting strategies are proposed. Using laser to preheat powder allows EBM to be performed at a low powder bed temperature (EBM-LT), whereas using an electron beam to preheat powder allows SLM to be performed at a high powder bed temperature (SLM-HT). Ti6Al4V samples are fabricated using two different manufacturing strategies (i.e., EBM-LT and SLM-HT) and two conventional processes, i.e., EBM at a high powder bed temperature (EBM-HT) and SLM at a low powder bed temperature (SLM-LT). The temperature-dependent surface quality, microstructure, density, and mechanical properties of the as-built Ti6Al4V samples are characterized and compared. Results show that EBM-LT Ti6Al4V exhibits a higher ultimate tensile strength (981±43 MPa) and a lower elongation (12.2%±2.3%) than EBM-HT Ti6Al4V owing to the presence of α′ martensite. The SLM-HT Ti6Al4V possesses the highest ultimate tensile strength (1,059±62 MPa) and an elongation (14.8%±4.0%) comparable to that of the EBM-HT Ti6Al4V (16.6%±1.2%).

Hygrothermal Aging Characteristics of Silicone-Modified Aging-Resistant Epoxy Resin Insulating Material.

To study the improvement effect of silicone materials on the hygrothermal resistance of epoxy resin and the aging mechanism of silicone-modified insulation materials under hygrothermal conditions, diphenylsilanediol was added to epoxy resin as a modifier in various quantities to synthesize silicone-modified epoxy resin, and a hygrothermal aging test was carried out. Water sorption, surface contact angles and dielectric properties of the insulation material were measured, and scanning electron microscope (SEM), Fourier-transform infrared spectrometry (FT-IR) and frequency domain spectroscopy (FDS) were used to analyze the results. The results showed that under 10 wt%, the silicone-modified insulation materials exhibited lower absorption rate and better dielectric properties, including lower dissipation factors and lower dielectric constant during the hygrothermal aging process, while epoxy resin modified with excessive silicone material tend to show worse dielectric performance. Closer analysis found that diphenylsilanediol decreases the size of the cracks within the material during hygrothermal aging, indicating that cracks generated during the hygrothermal aging process may be the reason for the worse dielectric performance, and diphenylsilanediol improves the hygrothermal aging resistance mainly by slowing down the generation and growth rate of cracks. FT-IR results confirmed the existence of hydrolysis and found that the rate of hydrolysis does not change with the content of diphenylsilanediol. FDS results also indicated that modified materials contain less dipoles after hygrothermal aging.

Natural cellulosic material characteristics: A possibility to develop antimicrobial active fiber-based packaging

Coconut husk, rubberwood sawdust, and palm leaf base are cellulosic agricultural wastes that have potential to be processed to fiber as absorbing material. This study investigated characteristics (morphological, physiological properties, chemical composition, absorption capacity, and water absorption isotherms) of coconut, rubberwood, and palm fiber. Also, the study aimed to develop an antimicrobial sachet packaging to resist against foodborne pathogens (Listeria monocytogenes, Staphylococcus aureus, Salmonella spp., and Escherichia coli) by adding lime oil (LO) emulsion or Litsea cubeba (LC) oil at 50 to 700 µL into the material (1 g) before, and then dried and placed in the 1-L seal box. Results showed that among the three, coconut performed the best in terms of releasing the essential oil (EO) emulsion against bacteria. Coconut could adsorb and release volatile LO or LC at the lowest concentrations (LO, 500 µL/L; LC, 300 µL/L) to inhibit bacteria compared with the other fibers (700 µL/L) at 35 °C. Results indicated that coconut has a low water absorption rate, which influenced the faster adsorption of EO emulsion in the beginning of the process; therefore, using low concentrations of EO in coconut for bacterial inhibition is possible. Coconut contains 34.5% lignin, 68.7% holocellulose, 37.6% cellulose, and 31.2% hemicellulose. Coconut is suitable as an alternative to the biocomposite material in developing a new antimicrobial packaging design.

Heat transfer modelling of semi-suspension biomass fired industrial watertube boiler at full- and part-load using CFD

In the current work, a computational fluid dynamics model is presented of a semi-suspension fired bagasse boiler which pays special attention to resolving the heat transfer to the furnace walls, superheater tubes and evaporator tube bank. The boiler CFD model includes custom-developed sub-models programmed in the C language which captures the fuel particle grate interaction, cylindrical fuel particle drag effects, superheater steam side heat transfer and evaporator heat exchange using a porous media approach. The model is applied to simulate the case study boiler for 100% and 65% load cases. The CFD model results are verified using a steady-state process model which utilizes well-known empirical heat transfer correlations. The CFD model results are also validated using plant measurements. The results of the CFD model show that it can accurately predict the outlet steam temperatures of the superheaters with relative errors of between 0.89 and 1.6% compared to the site data. The model is also capable of accurately predicting the evaporator outlet gas temperatures with a relative error of approximately 1.4%. Once the model is verified and validated it is used to investigate heat flux and metal temperature distributions in the various heat exchangers. The results show that at part load conditions the combustion occurs much closer to the furnace rear wall due to deeper spreading of the fuel particles, which results in the front wall having a relatively low heat absorption rate compared to the side and rear walls.

Vacuum laser beam welding characteristics for aluminum alloys and its effects on plasma plume generation and laser weldability

The laser weldability of aluminum alloy is unstable due to low laser beam absorption rate, low viscosity, and high thermal diffusivity. As a result, defects such as porosity and sagging are easily formed in the fusion zone. Vacuum laser beam welding (VLBW) has been introduced to ensure better weldability by using a relatively low ambient pressure. This allows for deep penetration depth and stable keyhole behavior compared to welding under atmospheric conditions. To evaluate the effects of ambient pressure on laser welding characteristics, VLBW was performed with similar and dissimilar aluminum alloys. Varying the pressure inside the vacuum chamber affected the welding characteristics. It is inferred that variation in ambient pressure changes the interactions between the laser source and substrate, such as the laser energy transfer, plasma plume generation, and the behavior of keyhole and molten pool. The penetration depth increased with decreasing ambient pressure for the same heat input conditions. Also, decreasing the ambient pressure reduced the formation of defects such as sagging, underfill, and porosity. Plasma plume generation was also varied depending on the ambient pressure, and plasma plume height and intensity were compared using a CCD camera. In this experiment, an ambient pressure of 10 mbar was sufficient to ensure good welding properties and stability. Below 10 mbar, the VLBW system is considered an effective alternative to processes that require high vacuum environments.

High-performance broadband photodetector with in-situ-grown Bi2Se3 film on micropyramidal Si substrate

Topological insulators have broad applications in the new generation of electronic devices and optoelectronic devices. Due to its narrow bandgap of 0.3 eV, Bi2Se3 film is a promising material for applications regarding visible light and infrared photodetection. However, the performance of photodetectors based on Bi2Se3 film is usually limited by the low absorption rate and the poor junction quality. In this work, we directly grew Bi2Se3 film onto the micropyramidal silicon by low-cost physical vapor deposition (PVD) method. Due to the light trapping of the micropyramidal substrate, and the high junction quality resulted from in-situ grown interface, the Bi2Se3/Si heterostructure has good photoresponse under broadband laser illumination of wavelengths from 635 to 2700 nm, which includes an excellent photo-to-dark ratio of 1.01 × 104, dark current of 0.11 nA, specific detectivity of 1.24 × 1011 Jones, and a fast response speed of microseconds. The etching process is found to be critical for the improvement of photoresponse. Our studies show a promising way to develop simple-technology, low-cost, high-efficiency heterojunction.

Jellyfish ( Aurelia aurita ) collagen scaffolds potential in alveolar bone regeneration

Background: Collagen scaffold is one of the most important parts of bone engineering especially for the alveolar bone regeneration. Jellyfish Aurelia aurita is one of the marine animals with the most potential for the development of collagen scaffold due to its high content of collagen and amino acid. This research aimed to evaluate the potential of jellyfish A. aurita collagen scaffold as a supporter for alveolar bone regeneration. Methods: Collagen was extracted from jellyfish by sonication method while scaffold was prepared by freeze-drying method, and chemical cross-linking with N-(3-dimethyl aminopropyl)-N’-ethyl-carbodiimide hydrochloride (EDC). Scaffold was characterized using Scanning Electron Microscope (SEM), Energy Dispersive X-Ray (EDX) spectroscopy, Fourier Transformed Infra-Red (FTIR), Cytotoxicity test with human mesenchymal stem cells (hMSCs), and biodegradability test. Results: The scaffold has a porous surface with a slightly rough texture and it has pores with size 159.9mm – 325.6mm. Carbon and oxygen are the highest elements in the scaffold. Based on FTIR results, the collagen scaffold with EDC has a lower infrared absorption rate compared to collagen scaffold without EDC. The result in cytotoxicity test showed that collagen scaffold that had been combined with EDC was not toxic to human mesenchymal stem cells (hMSCs) and even able to increase the cells growth. The scaffold with EDC has been degraded slower compared to the scaffold without EDC. Conclusion: The collagen scaffold is appropriate with the requirements as the biomaterial in supporting the alveolar bone regeneration, by fulfilling the following criteria, such as biocompatible, biodegradable, ideal porous interconnection, non-toxic, and cell viability support.

Recent advances in development of nanostructured photodetectors from ultraviolet to infrared region: A review

Herein, we aim to evaluate the photodetector performance of various nanostructured materials (thin films, 2-D nanolayers, 1-D nanowires, and 0-D quantum dots) in ultraviolet (UV), visible, and infrared (IR) regions. Specifically, semiconductor-based metal oxides such as ZnO, Ga2O3, SnO2, TiO2, and WO3 are the majority preferred materials for UV photodetection due to their broad band gap, stability, and relatively simple fabrication processes. Whereas, the graphene-based hetero- and nano-structured composites are considered as prominent visible light active photodetectors. Interestingly, graphene exhibits broad band spectral absorption and ultra-high mobility, which derives graphene as a suitable candidate for visible detector. Further, due to the very low absorption rate of graphene (2%), various materials have been integrated with graphene (rGO-CZS, PQD-rGO, N-SLG, and GO doped PbI2). In the case of IR photodetectors, quantum dot IR detectors prevails significant advantage over the quantum well IR detectors due to the 0-D quantum confinement and ability to absorb the light with any polarization. In such a way, we discussed the most recent developments on IR detectors using InAs and PbS quantum dot nanostructures. Overall, this review gives clear view on the development of suitable device architecture under prominent nanostructures to tune the photodetector performance from UV to IR spectral regions for wide-band photodetectors.

Liposomal azelaic acid 20% cream vs hydroquinone 4% cream as adjuvant to oral tranexamic acid in melasma: a comparative study

Background Melasma negatively impacts patient’s quality of life (QoL). Although hydroquinone 4% is the most prescribed treatment, several side effects had been reported. The traditionally used azelaic acid 20% has poor tolerability and low skin absorption rate. Aim To assess the efficacy and tolerability of the liposomal form of azelaic acid 20% as an adjuvant to oral tranexamic acid in the treatment of melasma. Patients and methods Fifty females suffering from melasma were divided into two equal groups. The first group used a liposomal form of azelaic acid 20%, and the second group used hydroquinone 4%. Oral tranexamic acid 250 mg was taken by both groups as a single oral daily dose. Melasma severity and the patient’s QoL were assessed. Results A significant improvement of melasma was detected in females who used the liposomal form of azelaic acid 20% than those who used hydroquinone 4%. This was associated with a significant positive effect on their QoL. Furthermore, the liposomal form of azelaic acid 20% was more significantly tolerable than hydroquinone 4%. Conclusion The use of the liposomal form of azelaic acid provides an effective and well-tolerated addition to the treatment of melasma.

Modeling and analysis of CO2 capture by aqueous ammonia + piperazine blended solution in a spray column

Chemical scrubbing using NH3/PZ solution is a promising pathway for mitigating CO2 emission from fossil-fuel combustion. Herein, we developed an advanced model that can predict CO2 absorption using the blended solvent in a spray column. The model was established in the computational fluid dynamics framework coupled with the properties of the blended solvent. The blended properties were evaluated using the linear combination of each single solvent. The established model was also verified by our previous experimental results. The deviations were found to be within ±15%. Further case studies revealed crucial characteristics of the scrubbing process. Due to the entrainment effect, intensive back-mixing behavior was observed in the gas flow. Energy analysis showed that the heat for water warming-up and evaporation mainly comes from the heat released by the CO2 absorption. The profiles of the gaseous species demonstrated that gaseous concentrations of NH3 and H2O vapor quickly approached their equilibrium values, whereas gaseous CO2 concentration exhibited different variation trends along the column. We also found that the gas-side mass-transfer coefficient was two orders of magnitude greater than the liquid-side. Moreover, the spatial separation of the maximum mass-transfer coefficients and the driving force led to a low CO2 absorption rate. The comparisons of the upward and downward spraying schemes indicated that the upward spraying can mitigate the spatial separation and increase droplet residence time and volume fraction, significantly improving the CO2 removal efficiency from 48.2% to 55.9%.

An innovative multi-zone configuration to enhance the charging process of magnesium based metal hydride hydrogen storage tank

High-temperature metal hydride (MH), such as magnesium hydride, is considered as one of the most promising technology to store hydrogen. However, there are two main bottlenecks, including the low rate of hydrogen absorption and low capacity of the MH reactor. In this regard, heat removal from the MH tank plays a crucial role in the hydrogen storage process. In the present study, to increase the hydrogen absorption performance, a novel configuration of the MH reactor is proposed and simulated using computational fluid dynamics (CFD). The study aims to assess the geometrical parameters of the proposed heat exchanger. Besides, a sensitivity analysis of the operating parameters of the reactor, including the Reynolds number and temperature of the air as well as hydrogen supply pressure is performed. The results indicate that the charging time drops significantly by increasing the number of air passages since the heat transfer rate improves dramatically. By raising the heat transfer fluid initial temperature, the charging time increases; however, as the heat transfer fluid Reynolds number and the inlet pressure of hydrogen increase, the absorption process accelerates. The recommended configuration is introduced by considering both charging time and manufacturing limitations. It is shown that the loading is approximately 30 minutes for the new multi-zone hydrogen energy storage using four passages for the air which provides a more applicable hydrogen fuel system.

Preparation and Characterization of Polyvinyl Alcohol‐Chitosan/Cerium Hydrogel with Significant Antibacterial Activity

AbstractTraditional wound dressings have some major deficiencies, including poor antibacterial ability, low exudate absorption rate and dry environment. These defects can be addressed by the prepared hydrogels in this study, which can provide a moist and cool environment for wound healing. Polyvinyl alcohol‐chitosan/cerium (PVA‐Cs/Ce) composite hydrogels are prepared by a freeze‐thaw method and characterized by x‐ray diffraction (XRD) and scanning electron microscopy (SEM). In addition, the effects of chitosan/cerium (Cs/Ce) complexes with different contents on properties, including mechanical properties, water vapor permeability, swelling ratio, and thermal stability are investigated. SEM images indicate that the composite hydrogels have a good three‐dimensional pore structure. Compared with the pure PVA hydrogel, the composite hydrogels show better swelling properties and more suitable water vapor transmission rate (2504 g m‐2·day) by adding Cs/Ce complexes. And the elongation at break of the hydrogel with a ratio of 5:3 (PVA: Cs/Ce) is the highest value of 567%. In the bacteriostatic circle experiment, PVA‐Cs/Ce composite hydrogels exhibit a pronounced inhibitory effect against two bacteria (Staphylococcus aureus and Escherichia coli). These results suggest that these composite hydrogels have great potential as wound dressings.

Factors affecting labour absorption in South Africa

Orientation: South Africa’s continually growing unemployment rates appear to be acute if measured by means of labour absorption. The country’s labour continues to struggle being absorbed in the labour market, let alone finding good and sustainable employment, hindering potential economic growth and development. Research purpose: The study aims to analyse and understand factors affecting labour absorption in South Africa. Motivation for the study: South Africa is characterised by limited job opportunities and a rapidly expanding labour force. Therefore, critically understanding factors contributing to low absorption rates could assist in harnessing and re-evaluating the effectiveness of existing labour policies. Research approach/design and method: The study uses quarterly time series data from 2008Q2 to 2019Q1. The Autoregressive Distributed Lag (ARDL) model was used to estimate the long-run and short-run relationships between the chosen variables. Main findings: The study found a long-run relationship between the selected variables and labour absorption. One main finding is that in the long run, the number of male work-seekers leads to a declining labour absorption rate, whilst the number of female work-seekers results in an increase in labour absorption. Practical/managerial implications: For many years, females have endured negative employment outcomes as a result of existing inequalities in the labour market. The findings of this study reveal the potential effectiveness of South Africa’s employment policy in reversing such statistics. A further study with a more defined focus on labour absorption, employment policy and gender should be undertaken to enhance the understanding on labour’s absorptiveness in the labour market. Contribution/value-add: Labour absorption is a broader measure of labour market performance than unemployment, because it comprises the labour force participation behaviour. Therefore, this study takes a much broader angle than most studies on unemployment.

Cost-Effective Nanoporous Hypercross-linked Polymers Could Drastically Promote the CO2 Absorption Rate in Amine-Based Solvents, Improving Energy-Efficient CO2 Capture

Energy-efficient solvents with favorable thermodynamic properties that offer significantly low regeneration energy to the state-of-the-art CO2 capture technologies are typically limited by slow reactivity with CO2. To compensate for low absorption rates, herein, we report that the nonporous hypercross-linked polymeric (HCP) networks as rate promoters are capable of drastically accelerating CO2 absorption in N-methyldiethanolamine (MDEA) sorbents. It is a new topic toward the application of HCPs. Two HCPs were synthesized from cost-effective monomers: polystyrene (HCP-S) and benzene (HCP-B), and then the novel slurry solvents were prepared by suspending HCP-S and HCP-B in MDEA solutions. Benefiting from the inherent properties, HCP-S and HCP-B increased the overall rates of CO2 absorption in the MDEA solution by 253 and 130%, respectively, compared to the blank MDEA. The effect of temperature and amine concentration on the promoting performance of HCP-B was investigated. HCP-B promotes CO2 sorption in the whole temperature range from 25 to 80 °C, and at 2 to 4 molar concentrations of MDEA. The promoting effect of HCP-B was also observed in the DEA solvent, demonstrating that it is not unique to MDEA. Moreover, 13C NMR analysis was used to confirm the promoting effect of the network on CO2 sorption, and a possible mechanism was investigated.

Dual-layer graphene based tunable broadband terahertz absorber relying on the coexistence of hybridization and stacking effects

With the fast development of terahertz (THz) techniques, THz absorbers have a variety of applications. However, current designs have a series of shortcomings, such as low absorption rate and a fixed and narrow absorption bandwidth. To solve such problems, in this paper, we design a tunable broadband THz absorber, which consists of two layers of graphene structures: the top layer is arrayed with the graphene concentric hexagonal rings and the bottom layer is arrayed with regular graphene hexagon rings; therefore, both layers support hybridization and stacking effects. The coexistence of both effects achieves the absorption rate of over 90% in a broad band from 0.93 THz to 1.80 THz. Moreover, the absorption spectrum can be tuned by adjusting the graphene chemical potential, which is insensitive to both incident angle and polarization. Considering advantages such as a tunable broad absorption band, a high absorption rate and insensitive incident angle and polarization, the proposed dual-layer graphene based tunable broadband THz absorber can be a useful reference for absorber design even in other electromagnetic wavebands.

Nanotechnology-Based Strategies for Berberine Delivery System in Cancer Treatment: Pulling Strings to Keep Berberine in Power.

Cancer is a multifactorial disease characterized by complex molecular landscape and altered cell pathways that results in an abnormal cell growth. Natural compounds are target-specific and pose a limited cytotoxicity; therefore, can aid in the development of new therapeutic interventions for the treatment of this versatile disease. Berberine is a member of the protoberberine alkaloids family, mainly present in the root, stem, and bark of various trees, and has a reputed anticancer activity. Nonetheless, the limited bioavailability and low absorption rate are the two major hindrances following berberine administration as only 0.5% of ingested berberine absorbed in small intestine while this percentage is further decreased to 0.35%, when enter in systemic circulation. Nano-based formulation is believed to be an ideal candidate to increase absorption percentage as at nano scale level, compounds can absorb rapidly in gut. Nanotechnology-based therapeutic approaches have been implemented to overcome such problems, ultimately promoting a higher efficacy in the treatment of a plethora of diseases. This review present and critically discusses the anti-proliferative role of berberine and the nanotechnology-based therapeutic strategies used for the nano-scale delivery of berberine. Finally, the current approaches and promising perspectives of latest delivery of this alkaloid are also critically analyzed and discussed.

Phytosterols: From Preclinical Evidence to Potential Clinical Applications.

Phytosterols (PSs) are plant-originated steroids. Over 250 PSs have been isolated, and each plant species contains a characteristic phytosterol composition. A wide number of studies have reported remarkable pharmacological effects of PSs, acting as chemopreventive, anti-inflammatory, antioxidant, antidiabetic, and antiatherosclerotic agents. However, PS bioavailability is a key issue, as it can be influenced by several factors (type, source, processing, preparation, delivery method, food matrix, dose, time of administration into the body, and genetic factors), and the existence of a close relationship between their chemical structures (e.g., saturation degree and side-chain length) and low absorption rates has been stated. In this sense, the present review intends to provide in-depth data on PS therapeutic potential for human health, also emphasizing their preclinical effects and bioavailability-related issues.