Search

Introduction The objective of this study was to evaluate the cell viability of layered cell sheets, irradiated with 222 nm UV light. Methods UV transmittance of 222 nm and 254 nm was evaluated when the cell sheets of NCTC Clone 929 cells were irradiated UV light. Cell viability was evaluated after irradiation of 222 nm using 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay. Following irradiation of two layered cell sheets at 500 mJ/cm2, the cell damage of lower layers was evaluated by a colony formation and MTT assays. Results The UV transmittance of 222 nm was 10 times less than that of 254 nm. A MTT assay revealed that cells of cell sheets irradiated at 222 nm was less damaged than those at 254 nm, when irradiated at 5 mJ/cm2. Cell colonies were formed for cells of lower layers irradiated at 222 nm whereas no colony formation was observed for those irradiated at 254 nm. Significantly higher MTT activity was observed for cells of lower layers irradiated at 222 nm than at 254 nm. Conclusions It is concluded that 222 nm irradiation is biologically safe for cell viability., Highlights • The cell viability of two-layered cell sheets was evaluated after irradiation of UV light at 222 nm. • UV light at 222 nm is safer to the lower layer than the conventional UV light at 254 nm. • The reason can be attributed to the lower transmission of UV light at 222 nm through cell sheets. • UV light at 222 nm could be one of promising tools to be required for the sterilization in the field of regenerative therapy.

Fe3O4@TiO2 magnetic photocatalytic particles were synthesized and characterized. A composite PVDF separation membrane blended with Fe3O4@TiO2 particles was prepared by the phase inversion method. The main purpose was to explore the effect of magnetic fields on the performance of membranes during coagulation bath. The structure characterization, permeability, interception ability, and anti-pollution performance of inorganic particle blend membranes were then tested. Results showed that magnetic field coagulation baths have little effect on the pore structure and hydrophilicity of the membrane surface. When the liquid membranes was condensed under a magnetic field, the magnetic photocatalytic particles could migrate at a greater rate to the surface of the membrane. Through performance tests of the PVDF modified membranes, it was found that a magnetic coagulation bath could promote more Fe3O4@TiO2 to aggregate on the surface of the membrane, which led to the blend membrane formed under the magnetic coagulation bath had better antifouling performance against humic acid solution under ultraviolet light irradiation. Membranes with 0.5 wt% magnetic photocatalytic particles in a magnetic field coagulation bath performed best. When filtered under the condition of ultraviolet light, its pure water flux was 1752 L/(m2 h), and the rejection rate of 20 mg/L humic acid solution was 67.17%. The flux attenuation before and after filtration was 38.84%, the flux recovery rate was 91.10%, and the irreversible pollution index was only 8.90%.

Most of TiO2 particles can be used as a photocatalyst for the selective oxidation of cyclohexane under ultraviolet light illumination. In this paper, Ti3+ self-doped TiO2 submicron-sized particles (i.e., Ti3+/TiO2 SMP) were used as a catalyst for visible-light driven photocatalytic cyclohexane oxidation. The microstructure and properties of the Ti3+/TiO2 SMP were characterized by X-ray diffraction (XRD), UV–visible diffuse reflection (UV–Vis DRS), scanning electron microscopy (SEM), electron paramagnetic resonance (EPR), solid-state photoluminescence spectroscopy (PLS) and X-ray photoelectron spectroscopy (XPS). The Ti3+/TiO2 SMP exhibits good visible-light driven photocatalytic performances for cyclohexane oxidation with cyclohexanone as a dominate product. Effects of solvent, reaction temperature, reaction time and oxygen pressure on the formation of cyclohexanone were investigated. The cyclohexane oxidation over the Ti3+/TiO2 SMP photocatalyst using carbon tetrachloride as a solvent under the optimal conditions presents a greater selectivity to cyclohexane (i.e., 95.1%). Based on the controlled experimental results with different radical scavengers, the hole (h+) is critical for the activation of cyclohexane. Keywords: Ti3+ self-doped TiO2, Cyclohexane oxidation, Photocatalysis, Selectivity

Boron carbon nitride (BCN) is an emerging metal-free catalyst for CO2 photocatalytic reduction. However, the fast electron-hole recombination as well as the weak absorption for ultraviolet-visible (UV-vis) light are still challenging for the activity upgrading of BCN. In this paper, a BCN/CeO2 heterostructure via N-O-Ce bonding was fabricated by a urea-assistant heat-precipitation technique and confirmed by XRD, FT-IR, SEM, TEM and XPS characterizations. For CO2 photoreduction with H2O as reducing agent, the BCN/CeO2 heterostructure delivered an obviously enhanced catalytic performance with CO yield of ca. 6-fold that of BCN. UV-vis diffuse reflectance spectrophotometer (DRS), electrochemical impedance spectroscopy (EIS) and transient photocurrent response measurements revealed that the electron-hole separation efficiency and charge transfer are efficiently promoted on CeO2/BCN heterostructure, along with the boosted light harvesting in visible and ultraviolet light range. Furthermore, based on the photo(electro)chemical and photocatalytic results, a possible CO2 photocatalytic reduction mechanism was proposed.

Purpose To evaluate the effect of magnesium on cellular adhesion and proliferation of human subacromial bursal tissue (SBT), osteoblasts, and tenocytes on nonabsorbable suture tape commonly used in rotator cuff surgery. Methods Human SBT cells, primary human osteoblasts (HOBs), and primary human tenocytes were isolated from tissue samples and cultured in growth media. Commercially available collagen-coated nonabsorbable suture tape was cut into one-inch pieces, placed into 48-well culture dishes, sterilized under ultraviolet light, and treated with (+) or without (–) magnesium. For the (+) magnesium group, a one-time dose of 5 mM sterile magnesium chloride was added. Subsequently, cells were plated at a density of 20,000 cells/cm2. For each cell source (SBT, HOBs, tenocytes) cellular proliferation and adhesion assays on suture tape treated (+) or (–) magnesium were performed. Results SBT, HOBs, and tenocytes each demonstrated the ability to adhere and proliferate on suture tape. Augmenting suture tape with magnesium resulted in a significantly increased cellular adhesion of SBT compared with nonaugmented sutures (P = .001), whereas no significant differences were observed for HOBs (P = .081) and tenocytes (P = .907). Augmentation with magnesium demonstrated no significant difference in cellular proliferation of SBT (P = .856), HOBs (P = .672), and tenocytes (P = .251) compared with nonaugmented sutures. Conclusions SBT, osteoblasts, and tenocytes each demonstrated the ability to adhere and proliferate on suture tape. In addition, augmenting the suture with magnesium resulted in a significantly increased cellular adhesion of SBT compared with nonaugmented sutures, whereas no significant differences were observed for osteoblasts and tenocytes. Further, magnesium did not impair the proliferative activity of SBT, osteoblasts, and tenocytes on suture tape used in rotator cuff surgery. Clinical Relevance Modifying the surface of the suture used for repair with application of magnesium may be an inexpensive and technically feasible option to improve the use of SBT for biologic augmentation of rotator cuff repair.

Novel benzazole derivatives were synthesized and their photophysical properties were determined experimentally in different types of solvents also by theoretical calculations using Density Functional Theory (DFT). The results of the theoretical computational studies were well consistent with those observed experimentally, evidencing the type of electronic transitions that occurs between the frontiers orbitals. All synthesized derivatives are highly fluorescent in the violet-green region (363-536 nm) under ultraviolet light of 365 nm with large Stokes shift due to excited state intramolecular proton transfer (ESIPT) mechanism. Furthermore, the thermogravimetric and differential thermogravimetric analysis showed their good thermal stability, with decomposition temperature up to 250 degrees C. The fluorescent benzazole derivative was successfully entrapped into starch-based microparticles and applied for visualization of latent fingerprints on different types of surfaces common to forensic cases (metal, plastic, paper, wood, and ceramic). info:eu-repo/semantics/publishedVersion

Injectable hydrogels are promising candidates for tissue engineering because of their easy and minimally invasive manipulation, and their ability to mimic the features of the extracellular matrix. Hydrogels developed from water-soluble polyphosphazenes are attractive due to the unique flexibility of phosphazene chemistry. In this study, a photocrosslinkable water-soluble polyphosphazene was synthesized by introducing citronellol with a double bond and hydrophilic diethylene glycol monomethyl ether as cosubstituted side groups; the corresponding hydrogel was obtained by exposing the polyphosphazene aqueous solution to ultraviolet light. Benefiting from the elastic polyphosphazene backbone and the flexible ether side group, the hydrogel exhibited excellent injectability and mechanical stability. To improve the hydrogel's mechanical and biological properties targeting biomedical applications, photocrosslinkable methacrylate gelatin and inorganic calcium phosphate were incorporated. The resulting composite hydrogels were able to retain excellent injectability, deformability and fatigue resistance, and were evaluated to be excellent for biomedical applications via in vitro cell culture and in vivo subcutaneous implantation. Keywords: Injectable, Polyphosphazene, Gelatin, Calcium phosphate, Hydrogel

Tuning the charge carrier concentrations of graphene is a fundamental feature to obtain highly efficient electronic and optoelectronic devices. We investigate the carrier density modulation in graphene by exposure of ultraviolet (UV) light in O2 and N2 atmosphere. The upshift in charge neutrality point of graphene field-effect transistor is observed by UV irradiation with O2 environment which attributes to the enhancement in hole concentration, while carrier modulation of graphene reverses to pristine state in N2 environment under UV irradiation. Furthermore, we are able to interpret the absorption or dissociation mechanism of oxygen atoms on graphene and their recombination with nitrogen atoms to the formation of NO or NO2 molecules, using density functional theory computation in generalized gradient approximation and Bader charge analysis. In addition, charge carrier modulation of graphene by UV irradiation under gas environment show no degradation effect in mobility of device. The experimental results corroborated with computational analysis rectify the utilization of such promising technique for graphene applicability in electronic devices. Keywords: Graphene, Ultraviolet irradiation, Reversible modulation, First-principle calculations

Breast cancer is one of the leading causes of cancer-related deaths in women. Chemotherapy remains one of the main clinical treatments for breast cancer. However, this therapy has appreciable side effects. Nanoscale carriers, such as metal nanoparticles and liposomes, are being widely utilized as drug delivery vehicles to achieve precise targeting of tumor cells. In this study, we designed a novel upconversion nanocarriers (UCNCs) host-guest complexation system based on a photolabile capping-like molecule. UCNCs containing epirubicin (EPI) were grafted with a dimer-targeting peptide via cyclodextrin-adamantine host-guest complexation. After entering breast tumor cells with the guidance of the dimer-targeting peptide, the core of the UCNCs upconverted near-infrared light to ultraviolet light which subsequently triggered the intracellular on-demand release of epirubicin. The precise and efficient delivery and release of epirubicin inside breast cancer cells significantly inhibited cancer cells proliferation, migration, and invasion in vitro and decreased the tumor size in vivo. We believe that this UCNCs system is a promising platform for the precise and controllable delivery of various chemotherapy drugs for clinical cancer treatments.

In the United States, every year an average of 287.1 eggs are consumed per person, and over 14.1 billion eggs are set in hatchery incubators to produce chicks destined for the egg and meat bird industries. By reducing the microbial load on eggs, food-borne–associated outbreaks can be reduced while good chick health is maintained. Pulsed ultraviolet (PUV) light system delivers an energy-intense broad spectrum (100–1,100 nm) pulse derived from a xenon flashlamp. In recent years, PUV light has been shown to reduce microbial pathogens on the surface of shell eggs by using a static PUV light system. In this study, shell eggs were surface inoculated with Escherichia coli or Enterococcus faecium and treated with PUV light using a modified egg candling conveyor that provided complete rotation of eggs under a flashlamp. Pulsed UV light treatment inactivated both microbial strains, with greater energy resulting in a greater germicidal response (P < 0.05). Treatments of 1.0, 2.4, 3.1, and 4.9 J/cm2 resulted in microbial reductions (Log10 CFU/cm2) of 3.83, 4.26, 4.28, and 4.62 for E. coli and 2.04, 3.12, 3.11, and 3.82 for E. faecium, respectively. This study also evaluated the effects of PUV light treatment of hatching eggs (commercial Leghorn hybrids) on both embryo and chick growth parameters. Using the same system, 4 replicates of 125 fertile eggs per rep were treated with 0 (control), 4.9, 24.4, or 48.8 J/cm2 of PUV light. After processing, eggs were placed in a commercial incubator under normal incubation conditions. There was no significant effect of the PUV light treatment on percent fertility, hatchability, or hatch (P > 0.05). Furthermore, there were no significant effects on posthatch observations, including livability and average bird weight at hatch or at 42 d of age (P > 0.05). In conclusion, this study supports the application of PUV light as an effective antimicrobial intervention for both table and hatching eggs.

In recent times, there is a significant increase in concern for the availability of clean drinking water. Among others, one source of water pollution is different textile industries that release different coloring agents, that is, dyes in their effluent after use. Therefore, researchers are presently focusing their significant interest in finding efficient techniques for removing such dyes from wastewater due to their hazardous effects on public health and the environment. Among the different dye-degradation treatments for contaminated water, photocatalytic dye degradation is an effective process of degrading the pollutants. Significant amounts of research have been done in photocatalytic dye degradation. However, visible light-activated photocatalysts’ development is still a big challenge, as most of the commercially available semiconductor photocatalysts work under ultraviolet light irradiation. Hence, finding alternative visible-light active photocatalysts is another important research topic for the future generation. In this chapter, we have tried to highlight the latest developments in syntheses, characterizations, optical and catalytic properties of some semiconductor nanomaterials, including those of some 2D materials for visible-light-induced photocatalytic dye-degradation applications. Here we have also presented a comparison of photocatalytic dye degradation performances of some 1D–2D semiconducting nanomaterials. Some conclusions have also been made about the technique of syntheses of some nanomaterials for achieving optimum dye-degradation performance even under sunlight irradiation. The present research studies furnished in this chapter are expected to be very useful in identifying some appropriate nanomaterials for the development of visible-light-induced photocatalytic materials for water purification and environmental remediation.

Wide bandgap semiconductor aluminum gallium nitride (AlGaN) alloys have been identified as the key materials to build ultraviolet light emitting devices owing to its direct tunable bandgaps from 3.4 to 6.1 eV, covering wide range of ultraviolet spectrum from 360 to 210 nm. In this chapter, we present the recent progress on the development of AlGaN-based thin-film ultraviolet laser diodes as well as the light emitting diodes, including their past, current and future efforts devoted in this exciting field.

Abiotic stresses like high temperature, ultraviolet light, drought, salt stress, etc., are the most harmful and unavoidable factors on Earth that affect crop yield. Among these, salinity stress perturbs the homeostasis of the K+/Na+ ratio. Different plant species survive under salinity stress via effector ion transport channels that regulate the excess concentration of Na+ ions, so as to avoid its drastic effect on vital metabolic pathways. Ion channels play a wider role to minimize and retranslocate the Na+ from shoot to root. Na+ generally translocates from the apoplastic and symplastic routes through the root system. Three kinds of defense lines mainly play a wider role to avoid excess Na+ loading. The first line of defense channels is reported as plasma membrane (PM) H+-ATPase. Pyrophosphatase acts as a primary transporter and generates the proton motive force (H+) as a proton gradient for facilitating the ion exchange activity of SOS1 antiporter. The second line of defense channels is localized in the vacuolar membrane, V-H+-ATPase, vacuolar pyrophosphatase as a primary transporter generating the same proton motive force in vacuolar sap that helps to sequester the Na+ in vacuole through antiporter channels (NHXs) by its ion exchange activity. The third line of defense system has been reported as high-affinity potassium transporter (HKT) channels that retranslocate the Na+ from xylem to phloem to avoid the Na+ toxicity in the shoot. Such defense mechanisms are very important for maintaining the optimum ratio of K+/Na+. Recent research works emphasized that most of these ion channels are regulated through a phosphorylation mechanism in its regulatory domain for functional activity, e.g., PM H+-ATPase and SOS1. The present chapter provides an overview of the major transporters regulating K+/Na+ homeostasis during abiotic stress.

Base excision repair (BER) and nucleotide excision repair (NER) are two DNA-repair pathways that, like other DNA-repair pathways except for direct reversal of DNA damage, involve sequential activities of multiple repair proteins. The two DNA-repair pathways have been studied for more than four decades, and this investigation has elucidated their crucial roles in maintaining genomic integrity particularly in response to exposure to environmental genotoxicants including ultraviolet light, cigarette smoke carcinogens, and reactive oxygen species. This chapter introduces the history and the concepts of DNA excision repair, discusses types of DNA damage processed by BER and NER, and describes the repair mechanisms. The detailed steps in these repair pathways in cells are complex and they require the coordination of the enzymatic reactions. Recent evidence indicates that DNA-damage and excision-repair proteins are key signal transducers and play critical roles for DNA-damage responses and communications between nuclei and mitochondria. Precise knowledge of BER and NER reactions should help us understand the roles that these key DNA-repair pathways play in preserving normal physiology which in turn should improve understanding of how defects in these pathways contribute to human disease with a particular emphasis on cancer.

Extensive research has been done to exploit solar energy for energy conversion and environmental remediation. For this purpose, heterogeneous photocatalysis based on semiconductor binary and ternary compounds is being widely studied. Almost all binary compounds show photocatalytic activity when irradiated by ultraviolet light, but the photocatalytic efficiency is hindered due to their bandgap and this limits their use as potential photocatalysts under the visible light region. Ternary compounds including metal oxides and chalcogenides have been effectively utilized for degradation of recalcitrant pollutants under the visible light. Various approaches have been considered to design visible light photocatalysts One such approach includes the formation of new energy levels among bands of semiconductor materials using various dopant species. Doping with plasmonic metals is usually proposed to resolve less photocatalytic efficiency of ternary compounds and to enhance their visible light response. Silver and its nanoparticles have been used extensively for wastewater treatment. Herein, the latest progress in the development of novel silver-doped ternary compounds by various synthesis methods has been discussed in detail. Moreover, the possible doping mechanism, charge transfer mechanisms, and enhanced photocatalytic activity for degradation of recalcitrant dyes and other pollutants owing to the surface plasmon response have also been described systematically.

Nanotechnology is a rapidly developing field of science. Scientific results and obtained nanomaterials offer the opportunity for innovations, also in the food sector—nanofood, the usage of nano techniques to modify food and package, displaying new functional properties. In the food sector, FBOs are mainly interested in safe, fresh-keeping products, as well as in the safety of the consumers (integrated quality control systems). That is why one of the nanomaterials focused the attention of the food sector. Titanium dioxide, which was previously successfully used in cosmetics or paintings, based on its characteristic active properties, generates reliable oxidizing power under UV light treatment. Currently this utility potential is tested in many areas within food production sector, as an effective tool for self-cleaning and self-disinfecting actions (different surfaces coatings), improved active packaging or air and water purification. The goals are effectiveness, low costs, and competitiveness to traditional methods, also in environmental remediation. At the same time, it is essential to remember about correct risk assessments and the needs of appropriate law regulations.

This chapter introduces the existing methods for detection and chemical composition analysis of fluid inclusions. It starts by introducing general optical microscopy research on fluid inclusions, including preparation of inclusion sheets, identification of fluid inclusions in the sheets, morphology of fluid inclusions under the microscope, and the phase state of matter in fluid inclusions. It then gives an overview of the modern research techniques for identifying fluid inclusions, including ultraviolet light microscopy, infrared microscopy, scanning electron microscopy, and high-resolution X-ray computed tomography. After that, it introduces how to determine the salinity of fluid inclusions. At the end of the chapter, it introduces the main extraction and analysis methods of fluid inclusion components, including the issues to be aware of in composition analysis of inclusions and the analytical methods of the chemical composition of group inclusions and individual inclusion.

Biodiesel is known as the best candidate for the replacement of nonrenewable biodiesel. Currently, it has been produced from transesterification and esterification of triglycerides and fatty acids, respectively. However, the production of biodiesel from waste oils surrounded by numbers of obstacle such as saponification problem, complex purification process, high-cost production, and dual-step processes has made them the least choice feedstock. Recently, an advanced scientific finding in the catalysis technology has been reported for the reduction of free fatty acid (FFA) from waste oils. Photocatalysis is a light-induced catalytic process that involves oxidization and/or reduction of organic molecules via redox reactions activated through the electron-hole pair generated on the surface of semiconductors upon light irradiation. The esterification of FFA with ethanol is carried out according to the Langmuir Hinshelwood reaction path: when a photocatalyst is irradiated by ultraviolet light, the photogenerated electrons (e−) in the valence band are excited and transferred to the conduction band, and the same number of holes (h+) will be produced. The methanol adsorbed on the catalyst surface reacts with photogenerated hole (h+) to generate H+ and radical methanol. At the same time, fatty acid molecules adsorbed on the surface of the catalyst is reduced to form free radical by accepting the photogenerated electron (e−) on the surface. Then, the reaction between radicals and protons will react to form methyl ester and water. In this chapter, we successfully studied, analyzed, and discussed the classical technique of biodiesel production, and fundamental, theories, concept, and potential of advanced photocatalysis technology in the biodiesel production.

Based on the first-principle calculations, we systematically study the electronic property, carrier mobility and optical absorption spectra in the monohydrogen(H), dihydrogen(2H) and Al edge-modified pristine sawtooth penta-graphene nanoribbons (SSPGNRs), respectively. Our results show that the SSPGNRs have suitable band gap, high carrier mobility and good optical absorption. The charge carrier mobility of SSPGNRs can be as high as 104 cm2 V−1 s−1, behave like n-type semiconductor, the different edge modifications enable SSPGNRs to convert from n-type to p-type semiconductor, and specifically, spin-splitting occurs in the band structure of the 2H-SSPGNR. Furthermore, the edge modifications can change the optical absorption that the absorption spectrum of Al-SSPGNR increases in visible and ultraviolet light regions obviously. The spin and optoelectronic properties of SSPGNRs with different edge modifications suggest its potential applications in spin electronics, optoelectronic devices and solar cells, which also provide some theoretical guidance for regulating the properties of SSPGNRs by edge modifications.

Ultraviolet (UV) irradiation induces physiological and morphological skin damage, resulting in skin dryness, wrinkle formation, and loss of elasticity. The basement membrane (BM) has been shown to play crucial roles in binding epidermis to dermis tightly, regulating cell differentiation and proliferation, and signaling protein production. Dietary flavonoids have been revealed to improve the damage caused by UV exposure. Immature Citrus unshiu is known to contain high concentrations of flavonoids such as hesperidin and narirutin. In this study, the effects of immature Citrus unshiu powder (ICP) on photoaged skin were demonstrated using UVB irradiated hairless mice. Oral administration of ICP improved loss of skin hydration and increase of transepidermal water loss. The histological analyses of hairless mice dorsal skin revealed that oral administration of ICP improved UVB-induced overgrowth of epidermal cell, suppressed epidermal cell mortality and BM destruction. Therefore, the administration of ICP could improve photoaging by protecting the tissues around BM., Biochemistry, Cell biology; Antioxidant; Phenolic compound; Food component analysis; Extracellular matrix; Aging; Citrus unshiu; Flavonoids; Hesperidin; Narirutin; Antioxidants; Photoaging; Ultraviolet light; Hairless mice; Basement membrane; Laminin.

HfO2 thin film is deposited on p-Si substrates by RF magnetron sputtering apparatus and annealed at 750 °C for 10 min with O2 atmosphere. Spectral analysis shows that HfO2 thin films have good transmittance to light, especially ultraviolet band. The HfO2 layers belong monoclinic phase and its thickness is about 50 nm. In the Au/HfO2/p-Si structure, photodiode characteristics were studied at room temperature and compared with the light current generated under white light, the response current generated under ultraviolet light is more prominent. The photocurrent reaches 80 μA and the repeatable response of device under 23.5 mW/cm2 ultraviolet illuminating is stable. It's found that the working mechanism of this photodiode could have three different states: the majority carrier stacking state of reverse bias, the majority carrier depletion state of forward bias with dark condition and the minority carrier inversion state of forward bias with ultraviolet illumination. The device also has a high damage threshold and its photocurrent is still not saturated at bias 8 V, indicating that it can be applied as a new type of UV detector. Keywords: HfO2 thin films, MOS device, Photodiode, Photocurrent, Free carriers

Background Ozone deterioration in the atmosphere has become a severe problem causing overexposure of ultraviolet light, which results in humans in melanin overproduction and can lead to many diseases, such as skin cancer and melasma, as well as undesirable esthetic appearances, such as freckles and hyperpigmentation. Although many compounds inhibit melanin overproduction, some of them are cytotoxic, unstable, and can cause skin irritation. Thus, searching for new natural compounds with antityrosinase activity and less/no side effects is still required. Here, bee pollen derived from sunflower (Helianthus annuus L.) was evaluated. Materials and methods Sunflower bee pollen (SBP) was collected from Apis mellifera bees in Lopburi province, Thailand in 2017, extracted by methanol and sequentially partitioned with hexane and dichloromethane (DCM). The in vitro antityrosinase activity was evaluated using mushroom tyrosinase and the half maximal inhibitory concentration (IC50) is reported. The antioxidation activity was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and reported as the half maximal effective concentration. Two pure compounds with antityrosinase activity were isolated by silica gel 60 column chromatography (SG60CC) and high performance liquid chromatography (HPLC), and their chemical structure deduced by Nuclear Magnetic Resonance (NMR) analysis. Results The DCM partitioned extract of SBP (DCMSBP) had an antityrosinase activity (IC50, 159.4 μg/mL) and was fractionated by SG60CC, providing five fractions (DCMSBP1–5). The DCMSBP5 fraction was the most active (IC50 = 18.8 μg/mL) and further fractionation by HPLC gave two active fractions, revealed by NMR analysis to be safflospermidine A and B. Interestingly, both safflospermidine A and B had a higher antityrosinase activity (IC50 of 13.8 and 31.8 μM, respectively) than kojic acid (IC50 of 44.0 μM). However, fraction DCMSBP5 had no significant antioxidation activity, while fractions DCMSBP1–4 showed a lower antioxidation activity than ascorbic acid. Conclusion Safflospermidine A and B are potential natural tyrosinase inhibitors., Biotechnology, Natural Product Chemistry, Pharmaceutical Chemistry, antityrosinase; Apis mellifera; Bee pollen; Purification; safflospermidine.

Diverse inorganic contaminants such as toxic heavy metals, nitrites, phosphates, chlorides, and other impurities consisting of pesticides, pharmaceuticals, perchlorates, halogenated and phenolic compounds, endocrine disrupting compounds, inorganic acids, herbicides, fertilizers, and numerous other compounds have been found in various ground, surface, and wastewater throughout the world. The critical sources amounting to water pollution consist of waste effluents ejected from different industrial units containing multifarious compounds, agricultural discharges containing plant nutrients, municipal wastewater containing surfactants, biodegradable matter and pathogens, improper radioactive and biomedical waste disposal, natural or geogenic seepages of elements such as arsenic, fluorides, selenium, and other heavy metals. The presence of these contaminants, even in trace amounts, are very threatening and hold humans, aquatic organisms, and flora and fauna vulnerable to various diseases and even death. The removal efficiency of these pollutants bank on the type of treatment method chosen, the concentration of impurities in water/wastewater, and environmental and geographical factors. The technologies utilized currently for water treatment include adsorption, photocatalysis, Fenton process, precipitation, flocculation, incineration, sedimentation, chlorination, coagulation, reverse osmosis, membrane filtration, electrochemical methods, activated carbon technologies, ion exchange, photo electrochemical techniques, ozonation and ultraviolet light, biodegradation, and sono-degradation. Adsorption technique has been established to be the most effective and economical method owing to its high efficiency and being inexpensive. Numerous natural and synthetic adsorbents such as agricultural waste, for example, bagasse, fruit peels, natural and modified clays, chitosan; industrial wastes, for example, dregs, grits and fly ash, biomass-based activated carbon, saw dust, nobel and precious metal-based nanomaterials, zeolites-based adsorbents, ferrite-based nanomaterials, nanocomposites, and dendritic polymers have been utilized as inexpensive adsorbents for treatment and removal of different contaminants from water and wastewater. Nanomaterials and carbon-based materials exhibit large number of distinct physical, structural, and chemical properties. Nano-zerovalent iron materials, metal–organic frameworks, carbon and graphene-based nanomaterials, biopolymers and hydrogel nanocomposite–based adsorbents and matrices are being utilized as upcoming technologies for water/wastewater purification. These nanomaterials are being utilized as sensors, effective adsorbents, and potential catalysts by virtue of their distinct physicochemical, electrical, structural, and mechanical properties. Low-cost adsorbents obtained from agricultural, biomass, and industrial residues and wastes can provide sustainable solution for treating wastewater. These adsorbents have required functionalities and characteristics, which allow the removal of harmful water pollutants from potable and wastewater, and at same time, these materials contribute toward minimization of wastes, their recovery, and reuse. The present chapter enumerates different type of adsorbents, their advantages, and disadvantages for water and wastewater treatment.

Development and improvement of nanosensors have been active research areas over the last few decades. Many materials and compounds have been investigated for their sensing properties. This work is concerned with developing a new sensing layer for gas sensors based on chitosan as a polymer enhanced with graphene as a nanofiller. The graphene used for preparing the chitosan solution was at 0.1, 0.5, and 1 wt%. Many characterizations (such as using different pore size, gas permeability, mechanical properties, and electrical resistance) were tested to give full insight into the nanocomposite. Oxygen was utilized as a sample gas for carrying out characterizing tests. The composite was found to demonstrate unique behavior: it was found to have a higher gas concentration gradient with decreasing graphene concentration, and higher electrical conductivity with increasing graphene concentration. These two criteria could be utilized to sense gases in two different ways, both mechanically and electrically. Further investigations were suggested to be carried out in the future to set the conditions (like air pressure, room temperature, ultraviolet light, etc.) for gas sensing.

This paper presents a new method for improvement of ultraviolet light driven photocatalytic activity of ZnO by immobilizing ZnO particles into Al2O3:Ce3+ coatings which emit intense radiation in the near ultraviolet region when excited by middle ultraviolet radiation. When Al2O3:Ce3+/ZnO coatings are illuminated by ultraviolet light in photocatalytic reactor, emitted ultraviolet radiation originating from Ce3+ ions synergistically participates in photocatalytic reactions on ZnO. Al2O3:Ce3+/ZnO coatings were formed by plasma electrolytic oxidation of aluminum in electrolyte containing 2 g/L of ZnO particles and up to 8 g/L of CeO2 particles. Structural, optical, photoluminescent, and photocatalytic properties of formed surface coatings were examined. All formed coatings feature virtually the same thickness, morphology, phase composition, and absorption properties. Concentration of incorporated Ce3+ ions into Al2O3 host and concentration of immobilized ZnO particles are the only parameters by which the coatings differ from each other resulting in difference in photocatalytic activity. Al2O3:Ce3+/ZnO coatings show better photodegradation of methyl orange with respect to Al2O3/ZnO coatings. The best photocatalytic activity is observed for the coating formed in electrolyte containing 4 g/L of CeO2 particles.

Conventional disinfection methods are limited by reliance on the operator to ensure appropriate selection, formulation, distribution, and contact time of the agent. Automated room disinfection (ARD) systems remove or reduce reliance on operators and so they have the potential to improve the efficacy of terminal disinfection. The most commonly used systems are hydrogen peroxide vapor (H2O2 vapor), aerosolized hydrogen peroxide (aHP), and ultraviolet (UV) light. These systems have important differences in their active agent, delivery mechanism, efficacy, process time, and ease of use. The choice of ARD system should be influenced by the intended application, the evidence base for effectiveness, practicalities of implementation, and cost considerations.

Portable water purification devices are needed to provide safe drinking water in rural communities, developing communities with low quality centralized water distribution, and military or recreational applications. Filtration, ultraviolet light, or chemical additives provide a spectrum of alternatives to remove pathogens from water. For the first time, we design, fabricate and demonstrate the performance of a small portable photoelectric point-of-use device, and document its performance on pathogen inactivation. The device utilizes a commercial teacup from which TiO2 nanotube photoanodes were produced in-situ and, with a small rechargeable battery powered 365 nm light emitting diode, was able to achieve 5-log inactivation of Escherichia coli in 10 s and 2.6-log of Legionella in 60 s of treatment in model water samples. Treatment of natural water achieved a 1-log bacteria inactivation after 30 s due to matrix effects. The electro-photocatalytic disinfection reactor in a kup (e-DRINK) can provide a feasible and affordable solution to ensure access to clean water. More broadly, this work demonstrates the potential for illumination to improve the efficiency of electrocatalytic surfaces.

Healthcare-acquired Legionnaires’ disease is caused by exposure to Legionella in hospital drinking water. Disinfecting the drinking water system is an effective preventive measure. The efficacy of any disinfection measures should be validated in a step-wise fashion from laboratory assessment to a controlled multihospital evaluation over a prolonged period of time. In this chapter, we describe long-term systemic disinfection methods (copper‑silver ionization, chlorine dioxide, monochloramine, ultraviolet light, hyperchlorination), a localized disinfection method (point-of-use filtration), and short-term disinfection methods in outbreak situations (superheat-and-flush plus or minus hyperchlorination). Controlled evaluations by other hospitals with experience with the system under consideration are the strongest evidentiary demonstration of efficacy. We also discuss the importance of risk assessment and infection preventionists in the selection of hospital disinfection strategies. The infection preventionist should be consulted in the selection of a commercial disinfection system. Their input will assure that healthcare facilities personnel make an evidence-based selection. Regulations and guidelines pertaining to Legionella control and Legionnaires’ disease prevention can affect the need for and choice of disinfectant. These disinfectant technologies have also demonstrated efficacy against other problematic waterborne pathogens. Routine surveillance cultures of water for Legionella and monitoring of disinfectant concentrations are necessary for long-term efficacy.

Eruptive lentiginosis confined to areas of resolving psoriatic plaques (ELRP) is a rare occurrence. Several previous reports described this phenomenon after the use of different treatment modalities to resolve psoriatic plaques, including topical, ultraviolet light, and biologic therapies. We present a case of ELRP after treatment with ustekinumab. We completed a review of the literature synthesizing all available reports describing lentiginous macules at the site of resolving psoriatic plaques to describe the patient population, treatments, and clinical characteristics associated with this entity.

Adult T-cell leukemia/lymphoma (ATL) is a non-Hodgkin lymphoma caused by the human T-lymphotropic virus type 1. The indolent variant manifests on the skin as pruritic papules and plaques. Current treatment regimens for cutaneous ATL include watchful waiting; skin directed therapy, such as radiation, topical steroids, or ultraviolet light; or the use of oral agents, including interferon-α or zidovudine. Multiagent chemotherapy, notably mogamulizumab, is used for aggressive variantes.1,2 Chemotherapeutic agents used in ATL can be costly and associated with significant adverse effects. Imiquimod is an immunomodulator approved for actinic keratosis, primary superficial basal cell carcinoma, and genital warts. Off-label use has been efficacious in mycosis fungoides, lentigo maligna melanoma, HIV-negative Kaposi sarcoma, and primary cutaneous anaplastic large-cell lymphoma.3, 4, 5 We present a patient in whom nearly complete resolution of ATL was achieved with topical imiquimod therapy.

Metal halide perovskites have attracted tremendous interest because of their unique properties. Among these materials, organic–inorganic metal halide perovskite solar cells (PSCs) exhibit a rapid development with the power conversion efficiency (PCE) increased from initially 3.8% to nowadays 25.5%. However, the inherent chemical instability of organic–inorganic metal halide perovskite materials against moisture, heat, and ultraviolet light hinders their commercialization. Therefore, by replacing organic cations with inorganic cations, all-inorganic metal halide (IMH) PSCs are regarded as promising alternatives, and their PCEs have exceeded 20% since the first report in 2015. In this review, we discuss the latest progress of IMH perovskites and their applications in solar cells, which is followed by a summary of existent challenges in the IMH-PSC field and an outlook on future development.

Cutaneous squamous cell carcinoma is a common global cancer with Ultraviolet light recognized as the most significant risk factor. The other definite or plausible risk factors include immunosuppression, infection with oncogenic viruses, exposure to toxins, chemicals, chronic inflammatory skin disease and a high body mass index. This case highlights the rarity of the pathology in terms of size, the subtle transition of verrucous hyperplasia to cutaneous squamous cell carcinoma over a period of time and the fallibility of the frozen section report in deciding the optimum resection margins. The initial innocuous presentation represented a diagnostic challenge as it can be mistaken for other benign entities. A correlation between the history, clinical presentation, tumor biology and the histopathological characteristics helped us to unlock the jigsaw puzzle of approaching a rare condition with a modification in the surgical approach.

Development of new effective biocontrol agents is largely based on the antagonistic capacity of candidate agents against targeted pathogens in vitro. Different mechanisms contribute to such capacity, including the activity of cell wall-degrading enzymes, secretion of antimicrobial secondary metabolites, growth vigour and resistance to exogenous and endogenous toxins. In this study, a series of laboratory experiments were designed to improve the antagonistic activities of Trichoderma spp. against two plant fungal pathogens, Sclerotium rolfsii and Rhizoctonia solani. A simple but efficient mutagenesis programme was carried out using ultraviolet light to induce modifications in the genetic structure of two Trichoderma biocontrol agents, T. virens and T. asperellum. The obtained mutants were subjected to a) initial screening for media-permeable antifungal metabolites using the cellophane membrane-based method, and b) selected mutants were subjected to a series of antagonistic tests. Results revealed that the antagonistic potential of selected mutants was significantly improved against the two plant pathogens. Genetic stability test results indicated that the UV-derived mutant Tv3, maintained its elevated performance after 12 rounds of sub-culture. Gene expression analysis for five antagonism-associated genes were examined using real-Time PCR. Results revealed that the gene expression of two genes, chitinase 33, a cell wall degrading enzyme and, polyketide synthase, which is responsible for polyketide biosynthesis, a class of secondary metabolites with antimicrobial roles, were significantly upregulated in one of the mutated T. virens strains. Results of our in vitro antagonistic studies along with our molecular analysis indicate that the UV mutagenesis could be an effective strategy to improve Trichoderma antagonistic potential.

Ultraviolet light (UV, UVC) disinfection is a well-established technology for air, water, and surfaces treatments. In the last decade, UV technology found more applications in food production chain because this is economic, effective, and versatile dry processing technology that can potentially improve safety and preservation quality of different categories of foods. Traditional way of generating UVC light is using high-voltage arc-discharge mercury or amalgam lamps that can generate photons solely at 253.7 nm. Light-emitting diodes or LEDs are semiconductor devices that can also emit UVC light, but depending on the material properties of the diodes, they can emit photons at multiple wavelengths in the UV range between 255 and 365 nm. The germicidal effects of UV LEDs against bacteria, viruses, and fungi already have been demonstrated and reported along with the first applications for disinfection of air, water, and surfaces made for the “point of use” integration. Despite the fact that there are no commercial applications in food production yet, the UV LEDs are the next wave in the LED revolution that can bring numerous advantages for food processing, safety, and plants facilities disinfection. This chapter will present the introduction in basics of LEDs technology and will discuss the unique advantages of this technology for food safety applications. Also, economical, energy saving, and sustainability aspects of UV LED applications are introduced.