The effect of laser sintering on the microstructure, relative density, and cracking of sol-gel-derived silica thin films

Combining sol-gel processing and laser sintering is a promising way for fabricating functional ceramic deposition with high dimensional resolution. In this work, crack-free silica tracks on a silica substrate with a thickness from ~360 nm to ~950 nm, have been obtained by direct exposure to a CO₂ laser beam. At a fixed scanning speed, the density and microstructures of the silica deposition can be precisely controlled by varying the laser output power. The porosity of the laser-sintered silica tracks ranged from close to 0% to ~60%. When the thickness of the silica deposition exceeded the critical thickness (eg, ~2.2 μm before firing), cracks occurred in both laser-sintered and furnace-sintered samples. Cracks propagated along the edge of the laser-sintered track, resulting in the crack-free track. However, for the furnace heat-treated counterpart, the cracks spread randomly. To understand the laser sintering effect, we established a finite element model (FEM) to calculate the temperature profile of the substrate during laser scanning, which agreed well with the one-dimensional analytical model. The FEM model confirmed that laser sintering was the main thermal effect and the calculated temperature profile can be used to predict the microstructure of the laser-sintered tracks. Combining these results, we were able to fabricate, predesigned patterned (Clemson tiger paw) silica films with high density using a galvo scanner.

Depiction of personal protective equipment in popular war films

Background. Personal protective equipment (PPE) is worn by military personnel to protect from combat trauma. War films may not represent PPE accurately, even when considered realistic. There is a risk that the subtle influence of films may subvert the understanding of PPE amongst military personnel and civilians. Methods. An observational study compared the depiction of PPE within popular war films to real-life. Films were included if they depicted land-based warfare. Depiction of helmets, body armour, eye protection, gloves, combat boots and hearing protection was compared to benchmarks. Trends in PPE over time were analysed using linear regression. Results. There were 73 combat scenes viewed from 16 films. Combat boots were the most depicted (72 scenes; 99%); hearing protection was the least (two scenes; 3%). There were statistically significant differences in PPE adherence between real life and films for all items of PPE (p < 0.05), except for combat boots (p = 0.621). There were improvements over time for all PPE except for hearing protection. Conclusions. PPE adherence in modern war films is poor, but has improved over time. There is a hypothetical risk that this has a negative impact on perceptions by both civilians and military personnel.

Artistic representations of infectious disease

Artistic representations of disease are widespread yet largely ignored in health psychology research. In this paper we use two infectious diseases, tuberculosis and the plague, as tracers to study how infectious diseases are represented in novels, films, paintings, and songs. They were represented especially in terms of their causes and seriousness. Studying how diseases are represented in various art forms extends our understanding of how they are socially constructed. This knowledge can also be incorporated into the training of health care providers to sensitize them to issues in patient care.

Assessment of critical material attributes of polyethylene oxide for formulation of prolonged-release tablets

Physicochemical evaluation of polyethylene oxide (PEO) polymers with various molecular weights was performed at molecular (polymeric dispersion) and bulk level (powders, polymeric films, and tablets) with the aim of specifying polymer critical material attributes with the main contribution to drug release from prolonged-release tablets (PRTs). For this purpose, grades of PEO with low, medium, and high viscosity were used for formulating PRTs with a good soluble drug substance (dose solubility volume 15 ml). The results revealed a good correlation (r²=0.88) between in vivo data (pharmacokinetic parameters: C_max and AUC) and the elastic property of PEO films determined with the nanoindentation method, demonstrating that film level can also be used for the in vivo prediction of drug dissolution. The study confirmed that polymer molecular weight and its viscosity are the most important critical material attributes affecting drug dissolution (in vitro) and in vivo bioavailability (e.g. C_max and AUC). Our research revealed that the nanoindentation technique can distinguish well between various types of polymers, classifying PEO as the most ductile and polyvinyl alcohol as the most brittle. Finally, our study provides an approach for the determination of exact physical attributes of PEO as a critical material attribute from clinically relevant data, and it therefore fulfills the basic principles of product development by Quality by Design.

Recombinant Spider Silk-Silica Hybrid Scaffolds with Drug-Releasing Properties for Tissue Engineering Applications

Fabricating biomaterials with antimicrobial activity to prevent the growth of detrimental microorganisms is of great scientific and practical interest. Here, composite materials comprising recombinant spider silk proteins and mesoporous silica nanoparticles (MSN) loaded with selected antibiotics and antimycotics are fabricated into films and hydrogels. The derived composite materials exhibit excellent antimicrobial properties with sustained release of antibiotics over the course of 15 days. Furthermore, antibiotics/antimycotics inclusion does not impair the cytocompatibility of the composite materials, all of which promote fibroblast cell adhesion and proliferation. Finally, processing of spider silk-MSN composite hydrogels using 3D printing is shown to enable the fabrication of patient-specific antimicrobial implants to prevent infection in the near future.

Applied Trace Alkali Metal Elements for Semiconductor Property Modulation of Perovskite Thin Films

With the rapid consumption of energy, clean solar energy has become a key study and development subject, especially the when new renewable energy perovskite solar cells (PSCs) are involved. The doping method is a common means to modulate the properties of perovskite film. The main work of this paper is to incorporate trace amounts of alkali metal elements into the perovskite layer and observe the effects on the properties of the perovskite device and the majority carrier type of the perovskite film. Comparative analysis was performed by doping with Na+, K+, and Rb+ or using undoped devices in the perovskite layer. The results show that the incorporation of alkali metal ions into the perovskite layer has an important effect on the majority carrier type of the perovskite film. The majority carrier type of the undoped perovskite layer is N-type, and the majority carrier type of the perovskite layer doped with the alkali metal element is P-type. The carrier concentration of perovskite films is increased by at least two orders of magnitude after doping. That is to say, we can control the majority of the carrier type of the perovskite layer by controlling the doping subjectively. This will provide strong support for the development of future homojunction perovskite solar cells. This is of great help to improve the performance of PSC devices.

Synthesis and Characterization of New Layered Double Hydroxide-Polyolefin Film Nanocomposites with Special Optical Properties

In this study, we have synthesized new double layered hydroxides to be incorporated to low density polyethylene thermoplastic matrix. These new composites present promising applications as materials to build greenhouses due to the enhancement of their optical properties. A characterization of the modified nanoclay has been performed by means of X-ray fluorescence (XRF), X-ray Diffraction (XRD), Thermogravimetric analysis (TGA), and Fourier-transform infrared spectroscopy (FTIR). We have prepared a series of polyolefin-based films to evaluate the effect of the addition of a whitening agent (disodium 2,2'-((1,1'-biphenyl)-4,4'-diyldivinylene)bis(benzenesulfonate)), the modified hydrotalcite-like material and a commercial dispersant. The rheological and mechanical characterization of the films have proved that the inclusion of the modified-layered double hydroxides (LDHs) do not substantially affect the processing and mechanical performance of the material. On the other hand, optical properties of the nanocomposites are improved by reducing the transmission in the UVA region.

Heterojunction α-Fe2 O3 /ZnO Films with Enhanced Photocatalytic Properties Grown by Aerosol-Assisted Chemical Vapour Deposition

Type I heterojunction films of α-Fe₂ O₃ /ZnO are reported here as a non-titania based photocatalyst, which shows remarkable enhancement in the photocatalytic properties towards stearic acid degradation under UVA-light exposure (λ=365 nm), with a quantum efficiency of ξ=4.42±1.54×10^-4 molecules degraded/photon, which was about 16 times greater than that of α-Fe₂ O₃ , and 2.5 times greater than that of ZnO. Considering that the degradation of stearic acid requires 104 electron transfers for each molecule, this represents an overall quantum efficiency of 4.60 % for the α-Fe₂ O₃ /ZnO heterojunction. Time-resolved transient absorption spectroscopy (TAS) revealed the charge-carrier behaviour responsible for this increase in activity. Photogenerated electrons, formed in the ZnO layer, were transferred into the α-Fe₂ O₃ layer on the pre-μs timescale, which reduced electron-hole recombination. This increased the lifetime of photogenerated holes formed in ZnO, which oxidise stearic acid. The heterojunction α-Fe₂ O₃ /ZnO films grown herein show potential environmental applications as coatings for self-cleaning windows and surfaces.

Biopolymeric Films of Amphiphilic Derivatives of Chitosan: A Physicochemical Characterization and Antifungal Study

The chemical modification of chitosan has been an active subject of research in order to improve the physicochemical and antifungal properties of chitosan-based films. The aim of this study was to evaluate the physiochemical and antifungal properties of films prepared with chitosan and its derivatives containing diethylaminoethyl (DEAE) and dodecyl groups (Dod). Chitosans and selected derivatives were synthesized and characterized, and their films blended with glycerol and sorbitol (5%, 10%, and 20%). They were studied by means of the evaluation of their mechanical, thermal, barrier, and antifungal properties. The collected data showed that molecular weight (Mw), degree of acetylation, and grafting with DEAE and Dod groups greatly affected the mechanical, thickness, color, and barrier properties, all of which could be tailored by the plasticizer percentage. The antifungal study against Aspergillus flavus, Alternaria alternata, Alternaria solani, and Penicillium expansum showed that the films containing DEAE and Dod groups exhibited higher antifungal activity than the non-modified chitosans. The mechanical properties of highly soluble films were improved by the plasticizers at percentages of 5% and 10%, indicating these derivatives as potential candidates for the coating of seeds, nuts and fruits of various crops.

Emotional Intelligence in Elementary School Children. EMOCINE, a Novel Assessment Test Based on the Interpretation of Cinema Scenes

The aim of the present study was to validate a new procedure, called EMOCINE test, to measure the perception and understanding branches of emotional intelligence (EI) in 1,448 children, aged between 8 and 13 years, from elementary schools. This new tool consists of watching 15 cartoon film clips and interpreting them according to children's own emotional perception and comprehension. After completing the test, the participants were classifie, according to their responses and by using the latent class analysis, as naïve (16.1%), over-interpretative (33.5%), and sensitive (50.4%). An increase in sensitive responses was observed depending on participants sex (girls higher than boys), and academic grade (increasing over the grades). Participants from the sensitive latent class had a significant better behavior in the school/classroom, compared with those from naïve and over-interpretative groups. Likewise, significant differences between latent classes were observed in many psychological, emotional, and behavioral problems (mainly between sensitive vs. insensitive by naivety) such as: depression, post-traumatic symptomatology, attention problems, aggression, family problems, problems at school, problems with classmates, integration and social competence. In conclusion, EMOCINE is a novel and promising tool for the measurement of the perception and comprehension components of EI. The test, employing film clips, is more realistic and motivating than others using static images or written descriptions. Moreover, the test can predict or identify emotional and behavior problems in children.

Effect of Bay Leaves Essential Oil Concentration on the Properties of Biodegradable Carboxymethyl Cellulose-Based Edible Films

Films containing bay leaves essential oils (BEOs) were prepared and evaluated for edible packaging applications. The BEOs were extracted by the Soxhlet method, using ethanol or methanol as organic solvent. Then, films were prepared by “solvent casting” technique using carboxymethyl cellulose (CMC), with different concentrations for the as-obtained BEOs (from 1% to 30% wt.). The resulting films were characterized to evaluate their physical (thickness, moisture content, water solubility and water vapor permeability), optical (transparency and UV-light barrier), mechanical (tensile strength and elongation at break), antioxidant and antimicrobiological properties Attractive films were obtained for food active packaging applications, as they presented a high antioxidant activity (up to 99%) and total phenolic content, and good barrier properties against water vapor (50% improved of CMC) in the case of CMC-film containing 15% wt. ethanolic extract. Related to optical properties, UV-light barrier effect was increased (almost 100% of protection) avoiding typical lipids oxidation in food systems. High water solubility (93%) was also found, ensuring also their biodegradability. Moreover, it was demonstrated that developed films inhibit microorganisms’ growth (Escherichia coli and Candida glabrata), this avoiding an early food oxidation.

Utilizing Recombinant Spider Silk Proteins To Develop a Synthetic Bruch's Membrane for Modeling the Retinal Pigment Epithelium

Spider silks are intriguing biomaterials that have a high potential as innovative biomedical processes and devices. The intent of this study was to evaluate the capacity of recombinant spider silk proteins (rSSps) as a synthetic Bruch's membrane. Nonporous silk membranes were prepared with comparable thicknesses (<10 μm) to that of native Bruch's membrane. Biomechanical characterization was performed prior to seeding cells. The ability of RPE cells (ARPE-19) to attach and grow on the membranes was then evaluated with bright-field and electron microscopy, intracellular DNA quantification, and immunocytochemical staining (ZO-1 and F-actin). Controls were cultured on permeable Transwell support membranes and characterized with the same methods. A size-dependent permeability assay, using FITC-dextran, was used to determine cell-membrane barrier function. Compared to Transwell controls, RPE cells cultured on rSSps membranes developed more native-like "cobblestone" morphologies, exhibited higher intracellular DNA content, and expressed key organizational proteins more consistently. Comparisons of the membranes to native structures revealed that the silk membranes exhibited equivalent thicknesses, biomechanical properties, and barrier functions. These findings support the use of recombinant spider silk proteins to model Bruch's membrane and develop more biomimetic retinal models.

Chitosan/Essential Oils Formulations for Potential Use as Wound Dressing: Physical and Antimicrobial Properties

Film-forming emulsions and films, prepared by incorporating different concentrations of clove essential oil (CEO) and melaleuca essential oil (MEO) into chitosan (CS) were obtained and their properties were evaluated. Film-forming emulsions were characterized in terms of qualitative assessment, hydrogen potential and in vitro antibacterial activity, that was carried by the agar diffusion method, and the growth inhibition effects were tested on the Gram-positive microorganism of Staphylococcus aureus, Gram-negative microorganisms of Escherichia coli, and against isolated fungi such as Candida albicans. In order to study the impact of the incorporation of CEO and MEO into the CS matrix, the appearance and thickness of the films were evaluated. Furthermore, Fourier transform infrared spectroscopy (FTIR), contact angle measurements, a swelling test, scanning electron microscopy and a tensile test were carried out. Results showed that the film-forming emulsions had translucent aspect with cloudy milky appearance and showed antimicrobial properties. The CEO had the highest inhibition against the three strains studied. As regards the films' properties, the coloration of the films was affected by the type and concentration of bioactive used. The chitosan/CEO films showed an intense yellowish coloration while the chitosan/MEO films presented a slightly yellowish coloration, but in general, all chitosan/EOs films presented good transparency in visible light besides flexibility, mechanical resistance when touched, smaller thicknesses than the dermis and higher wettability than chitosan films, in both distilled water and phosphate-buffered saline (PBS). The interactions between the chitosan and EOs were confirmed by. The chitosan/EOs films presented morphologies with rough appearance and with EOs droplets in varying shapes and sizes, well distributed along the surface of the films, and the tensile properties were compatible to be applied as wound dressings. These results revealed that the CEO and MEO have a good potential to be incorporated into chitosan to make films for wound-healing applications.

How Do Arabinoxylan Films Interact with Water and Soil?

Biodegradable materials made from cereal arabinoxylan could provide an alternative source of packaging to replace current nonbiodegradable plastics. The main purpose of this research was to determine how arabinoxylan (AX) films made from wheat bran (WB) AX, maize bran (MB) AX, and dried distillers grain (DDG) AX made with either glycerol or sorbitol at varying levels (10, 25 or 50%) interacts with soil and water. The biodegradability of all films ranged from 49.4% biodegradable (DDG AX with 10% sorbitol) to 67.7% biodegradable (MB AX with 50% glycerol). In addition, the MB AX films with 25% sorbitol had the lowest moisture content at 9.7%, the MB AX films with 10% glycerol had the highest water solubility at 95.6%, and the MB AX films with 50% glycerol had the highest water vapor transmission rate (WVTR) at 90.8 g h^-1 m^-2. Despite these extreme trends in the MB AX films, the WB AX films were the least hydrophilic on average while the DDG AX films were the most hydrophilic on average. The 18 materials developed in this research demonstrate varying affinities for water and biodegradation. These materials can be used for many different packaging materials, based on their unique characteristics.

Relevance of Interactions between Starch-based Coatings and Plum Fruit Surfaces: A Physical-Chemical Analysis

In order to extend the shelf life of the fruit, improve appearance, and to keep all nutrition properties of the plum from diminishing, edible coatings comprised of wheat starch and wheat starch-whey protein isolate (in ratio 80/20) were created. Stand-alone films were produced to assess properties which helped to understand the phenomena occurring on the surface level of coated plums. The properties of coatings based on starch are similar to starch coatings containing oil because the natural epicuticular wax layer of plums merges with coating materials. Adding oil doubled the contact angle value and the dispersive component of the surface tension. The workings of adhesion and cohesion, spreading coefficient, water absorption, water content, and solubility in water of the films decreased. Similar processes were observed on the fruits' surface. In appearance, the coating process is similar to polishing the plum surface for removing crystalline wax. The color parameters of coated fruits did not significantly change. Newly formed bonds or interactions established between starch, whey proteins, water, glycerol, and oil are displayed by Fourier transform infrared (FTIR) analysis. This work revealed how the interactions between the epicuticular wax on the fruit's surface and the hydrocolloid-based coatings affect the efficiency of the coatings.

Effect of Cellulose Nanocrystals from Different Lignocellulosic Residues to Chitosan/Glycerol Films

Interest in nanocellulose obtained from natural resources has grown, mainly due to the characteristics that these materials provide when incorporated in biodegradable films as an alternative for the improvement of the properties of nanocomposites. The main purpose of this work was to investigate the effect of the incorporation of nanocellulose obtained from different fibers (corncob, corn husk, coconut shell, and wheat bran) into the chitosan/glycerol films. The nanocellulose were obtained through acid hydrolysis. The properties of the different nanobiocomposites were comparatively evaluated, including their barrier and mechanical properties. The nanocrystals obtained for coconut shell (CS), corn husk (CH), and corncob (CC) presented a length/diameter ratio of 40.18, 40.86, and 32.19, respectively. Wheat bran (WB) was not considered an interesting source of nanocrystals, which may be justified due to the low percentage of cellulose. Significant differences were observed in the properties of the films studied. The water activity varied from 0.601 (WB Film) to 0.658 (CH Film) and the moisture content from 15.13 (CS Film) to 20.86 (WB Film). The highest values for tensile strength were presented for CC (11.43 MPa) and CS (11.38 MPa) films, and this propriety was significantly increased by nanocellulose addition. The results showed that the source of the nanocrystal determined the properties of the chitosan/glycerol films.

Degradation and Recycling of Films Based on Biodegradable Polymers: A Short Review

The environmental performance of biodegradable materials has attracted attention from the academic and the industrial research over the recent years. Currently, degradation behavior and possible recyclability features, as well as actual recycling paths of such systems, are crucial to give them both durability and eco-sustainability. This paper presents a review of the degradation behaviour of biodegradable polymers and related composites, with particular concern for multi-layer films. The processing of biodegradable polymeric films and the manufacturing and properties of multilayer films based on biodegradable polymers will be discussed. The results and data collected show that: poly-lactic acid (PLA), poly-butylene adipate-co-terephthalate (PBAT) and poly-caprolactone (PCL) are the most used biodegradable polymers, but are prone to hydrolytic degradation during processing; environmental degradation is favored by enzymes, and can take place within weeks, while in water it can take from months to years; thermal degradation during recycling basically follows a hydrolytic path, due to moisture and high temperatures (β-scissions and transesterification) which may compromise processing and recycling; ultraviolet (UV) and thermal stabilization can be adequately performed using suitable stabilizers.

Evaluation of Clay-Functionalized Wafers and Films for Nicotine Replacement Therapy via Buccal Mucosa

The functional physicochemical properties of nicotine (NIC)-loaded composite freeze-dried wafers and solvent-evaporated films comprising hydroxypropylmethylcellulose (HPMC) and sodium alginate (SA), stabilized with magnesium aluminium silicate (MAS), have been reported. The formulations were characterized for swelling capacity, mucoadhesion, in vitro drug dissolution properties in simulated saliva (SS) and PBS at pH 6.8, and ex vivo and in vitro permeation using pig buccal mucosa membrane and EpiOralTM buccal tissue culture, respectively; finally, the cell viability of the EpiOralTM tissues after contact with the NIC-loaded formulations was investigated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the functional characteristics compared with those of commercially available NIC strips. Swelling and NIC release from the HPMC⁻SA wafers were more prolonged (30 min) compared to the commercially available NIC strips which disintegrated rapidly and released the drug within 5 min. Generally, swelling, mucoadhesion, and drug release was faster in PBS than in SS, and the presence of MAS was essential for maintaining a high dose recovery compared to non-MAS formulations and commercial NIC strips, which showed lower percentage of NIC content, possibly due to evaporation during analysis. Permeation studies showed that the NIC released was able to cross both porcine buccal membrane and the EpiOralTM buccal tissue, with the latter showing higher permeation flux for all the formulations tested. All the NIC-loaded, MAS-stabilized formulations showed high tissue viability, with values above 80%, showing their great potential for use as buccal delivery platforms for NIC replacement therapy to aid smoking cessation.

Photothermal-Assisted Optical Stretching of Gold Nanoparticles

The synergy of photothermal energy and optical forces generated by tightly focused laser beams can be used to transform the shape of gold nanoparticles. Here, the combination of these two effects is demonstrated to be an effective way of elongating gold nanoparticles (Au NPs), massively tuning their plasmonic properties. The photothermal effect of the laser increases the temperature of Au NPs above the melting point, and optical forces deform the molten Au NPs. As a result, the shape of Au NPs transforms from nanospheres into nanorods or dimers, depending on the power and time of irradiation as well as the surface energy of the substrate. This process is reversible by using high laser power to transform nanorods back to nanospheres due to capillary dewetting. Such light-induced transformations of nanostructures not only provide a facile way to tune plasmon resonances but also shed light on how the synergistic effect of photothermal energy and optical forces works on plasmonic nanoparticles.

Poly(lactic acid)/Cellulose Films Produced from Composite Spheres Prepared by Emulsion-Solvent Evaporation Method

The compound of poly(lactic acid) (PLA) and cellulose was made by the emulsion-solvent evaporation technique in order to obtain spheres which are then compression molded to produce a biocomposite film. The effect of the dispersant (poly(vinyl alcohol)-PVA)/PLA ratio on the spheres yield was studied. Moreover, to evaluate the effect of cellulose particle size and surface chemistry on the process yield, unbleached eucalypt kraft pulp and microcrystalline cellulose (MCC), both unmodified and physically or chemically modified were used. PLA/cellulose spheres were characterized regarding its physical properties. It was found that the spheres yield is essentially determined by the PVA/PLA ratio and the percentage of cellulose incorporation is greatly affected by the surface chemistry of cellulose. Regarding the films, DSC runs showed a significant effect of the cellulose type incorporated into PLA matrix on the cold crystallization temperature and on the degree of crystallinity of the biocomposite films. The measurement of tensile properties of the biocomposite films revealed that the strength, elongation at break and toughness (tensile energy absorption at break) of the films incorporating unmodified and chemically modified MCC were substantially improved.

Film wound dressing containing dexpanthenol - preparation and evaluation

Currently, a wide variety of wound dressings of varying composition and effects is used to treat wounds. These include also film dressings where one of the promising materials for its preparation is sodium carboxymethylcellulose (NaCMC) as a material of natural origin with excellent film-forming properties. Its application is particularly in the field of absorbent dressings, films for wounds from this material are not used in practice yet. Hidden potential offers also dexpanthenol, a substance widely used in dermatological practice. Therefore, the aim of this research was to prepare films from textile NaCMC with dexpanthenol by the solvent evaporation method and their subsequent physicochemical evaluation. The presence of microfibrillar fibers of partially substituted carboxymethylcellulose together with HCMC has ensured optimal parameters for wound application such as pH, swelling and mechanical properties. The films showed satisfactory mass content uniformity and those with dexpanthenol also drug content uniformity.

The Structure and Mechanical Properties of the UHMWPE Films Modified by the Mixture of Graphene Nanoplates with Polyaniline

Highly oriented UHMWPE films were reinforced with functionalized graphene nanoplates (GNP). GNP was functionalized by deposition of polyaniline (PANI) on the GNP surface. The structure of GNP/PANI was studied by Raman spectroscopy, and the structure of xerogels and films based on UHMWPE was studied by DSC and SEM. PANI promotes the reduction of the GNP aggregation in the UHMWPE matrix and increases the degree of crystallinity due to heterogeneous crystallization. The new lamellar crystal structure has a high drawability. The highest value of the tensile strength 1330 MPa (an increase of 45%) was obtained with a filler content of 2 wt % GNP/PANI, and the highest value of Young's modulus 41 GPa (an increase of 32%) was obtained with a filler content of 1 wt % GNP/PANI. The effect of GNP with PANI fillers on the dynamic mechanical properties of the UHMWPE films was discussed.

Synthesis and Characterization of Konjac Glucomannan/Carrageenan/Nano-silica Films for the Preservation of Postharvest White Mushrooms

In this study, the konjac glucomannan (KGM)/carrageenan (KC)/nano-silica film was prepared and characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The preservation quality of white mushrooms (Agaricus bisporus) packed using the films was also determined. The nano-silica dosage was found to affect the properties of the nanocomposite KGM/KC films. The results indicated that the properties of the films were significantly improved with the addition of nano-silica. The water vapor permeability, water solubility, moisture absorption, and light transmittance of KGM/KC/nano-silica films were significantly affected by the nano-silica dosage. In this study, the optimal nano-silica dosage to incorporate into the film in order to achieve excellent performance was 0.3%. Strong intermolecular hydrogen bonds were also observed between KGM/KC and nano-silica in the KGM/KC/nano-silica film by FTIR. In addition, the KGM/KC/nano-silica film markedly reduced the browning index, delayed the weight loss and softening, and extended the shelf life of mushrooms during storage at 4 °C. The KGM/KC film modified using nano-silica can provide a potential method for improving the preservation quality of white mushrooms during storage.

Development and evaluation of flipped learning using film clips within a nursing informatics course

AIM

To develop flipped learning classes by using film clips for undergraduate nursing students in an online nursing informatics course, based on the Analysis, Design, Development, Implementation, and Evaluation model, and to evaluate the effectiveness and students' responses to this method of teaching.

METHODS

Sixty-four second-year nursing students participated in the course. The nursing students' knowledge was assessed at the beginning and end of each of the five classes. Moreover, their intention to recommend the classes to other students and additional comments were elicited by using semistructured questionnaires.

RESULTS

Knowledge about each core concept of nursing informatics reflected significant improvement. Regarding the intention to recommend the class to others, 62 (96.8%) students answered "strongly recommend" or "recommend."

CONCLUSION

Integrating flipped learning classes by using film clips in an online nursing informatics course improved the nursing students' knowledge and is a format that is desired by students.