Psoriasis is a chronic inflammatory disease involving multiple organ systems and affecting approximately 3.2% of the world's population. In this section of the guidelines of care for psoriasis, we ...will focus the discussion on ultraviolet (UV) light–based therapies, which include narrowband and broadband UVB, UVA in conjunction with photosensitizing agents, targeted UVB treatments such as with an excimer laser, and several other modalities and variations of these core phototherapies, including newer applications of pulsed dye lasers, intense pulse light, and light-emitting electrodes. We will provide an in-depth, evidence-based discussion of efficacy and safety for each treatment modality and provide recommendations and guidance for the use of these therapies alone or in conjunction with other topical and/or systemic psoriasis treatments.
In this work, the degradation of cefalexin, norfloxacin, and ofloxacin was examined via various advanced oxidation processes (AOPs). Direct photolysis by ultraviolet (UV) and vacuum ultra violet ...(VUV) was less effective for the degradation of fluoroquinolone antibiotics such as norfloxacin and ofloxacin than that of cefalexin. Both hydrogen peroxide (H
O
) and potassium persulfate (K
S
O
) assisted UV/VUV process remarkably enhanced fluoroquinolone degradation. The addition of K
S
O
was superior to H
O
under VUV irradiation, with the best removal efficiency of norfloxacin and ofloxacin being almost 100% within 3 min in the presence of VUV/K
S
O
. The ofloxacin degradation rate was accelerated as concentrations of H
O
and K
S
O
was increased to 3 mM, but the degradation rate was slightly decreased with excess H
O
(>3 mM). The performance of modified VUV processes (i.e., VUV/H
O
and VUV/K
S
O
) was inhibited at highly alkaline condition (pH 11). The co-existence of halides (Cl
and Br
) enhanced antibiotics degradation via the modified VUV processes, but the reaction was almost unaffected in the presence of single halides. This study demonstrated that modified VUV processes (especially VUV/K
S
O
) are efficient for eliminating fluoroquinolone antibiotics from water, which can be considered as a clean and green method for the treatment of antibiotics-containing industrial wastewater.
The growth of single‐crystal III‐nitride films with a low stress and dislocation density is crucial for the semiconductor industry. In particular, AlN‐derived deep‐ultraviolet light‐emitting diodes ...(DUV‐LEDs) have important applications in microelectronic technologies and environmental sciences but are still limited by large lattice and thermal mismatches between the epilayer and substrate. Here, the quasi‐van der Waals epitaxial (QvdWE) growth of high‐quality AlN films on graphene/sapphire substrates is reported and their application in high‐performance DUV‐LEDs is demonstrated. Guided by density functional theory calculations, it is found that pyrrolic nitrogen in graphene introduced by a plasma treatment greatly facilitates the AlN nucleation and enables fast growth of a mirror‐smooth single‐crystal film in a very short time of ≈0.5 h (≈50% decrease compared with the conventional process), thus leading to a largely reduced cost. Additionally, graphene effectively releases the biaxial stress (0.11 GPa) and reduces the dislocation density in the epilayer. The as‐fabricated DUV‐LED shows a low turn‐on voltage, good reliability, and high output power. This study may provide a revolutionary technology for the epitaxial growth of AlN films and provide opportunities for scalable applications of graphene films.
Guided by density functional theory (DFT) calculations, a N2‐plasma‐treated graphene buffer layer is developed to grow high‐quality AlN for deep‐ultraviolet light‐emitting diode (DUV‐LED) applications. The plasma treatment of graphene can facilitate AlN nucleation, thus increasing the growth rate of the AlN film and improving the film quality. The as‐fabricated LED shows a low turn‐on voltage, good reliability, and high output power.
•Ultraviolet-induced NO removal by Fe(II)EDTA with exposed (001) facets nF-TiO2.•NO was removed through catalytic oxidation-complexation synergism.•NO is mainly converted into NO3–, NO2–, NH4+, N2, ...and N2O.•UV/Fe(Ⅱ)EDTA/5F-TiO2 system shows great potential for practical applications.
Ferrous ethylenediaminetetraacetate (Fe(II)EDTA) accompanied by regeneration is thought to be a very efficient method to remove nitric oxide (NO) from flue gas. However, Fe(II)EDTA regeneration requires a large amount of regenerant consumption. For this purpose, anatase titanium dioxide with exposed (001) facets by fluorination (nF-TiO2) was synthesized and combined with Fe(II)EDTA solution for NO removal with ultraviolet light (UV). The result showed that 5F-TiO2 with approximately 30 % (001) facets exposed can significantly promote NO removal of Fe(II)EDTA under UV irradiation, with an average removal efficiency of up to 94.83 % over a 60-minute period. The mechanism study indicated that the excellent removal performance of 5F-TiO2 was mainly because the moderate co-exposure of its (001) and (101) facets could greatly suppress the electron hole recombination rate, accelerate the Fe(Ⅱ)EDTA/Fe(III)EDTA cycle, and form catalytic oxidation-complexation synergism denitrification. Under this synergistic effect, NO from simulated flue gas was mainly transformed to NO3–, NO2–, NH4+, N2, and N2O. Subsequently, NO removal performance using UV/Fe(Ⅱ)EDTA/5F-TiO2 under different parameters demonstrated that appropriate oxygen concentration (3 vol%), suitable 5F-TiO2 mass (0.5 g), low temperature (30 ℃), and weak acidic environment (pH = 4) were favorable for NO removal. The kinetics demonstrated that NO removal by the UV/Fe(Ⅱ)EDTA/5F-TiO2 system was a pseudo-first-order process. Finally, UV/Fe(II)EDTA/5F-TiO2 denitrification technology shows great potential in practical applications. This work offers a new route for the greenandlow-costapplication of Fe(Ⅱ)EDTA denitrification in flue gas treatment.
This study was designed to develop a cold plasma +222 nm ultraviolet (CP + UV) sterilization device in the food industry. Response surface methodology was applied to evaluate the effects of three ...treatment conditions on the antibacterial activity of CP + UV. The optimum treatment conditions (plasma gas flow: 4 m3/min, irradiation distance: 4 cm, treatment time: 60 s) were selected to optimize the reactor parameters of CP and 222 nm UV sterilization equipment, and its effects against the growth of S. aureus on different food contact materials were investigated. Results showed that the antibacterial activity against S. aureus was strongest when the plasma was operated at 8.5 kHz, 2.5 W/cm2 with two net layers of electrodes arranged transversely at a distance of 5 cm between the plasma outlet plane and UV centerline plane. After 60 s of CP + UV treatment, the number of S. aureus on the glass sheet, polypropylene film, corrugated paper, and kraft paper decreased by 4.5, 4.1, 1.5, and 2.4, respectively (p < 0.05). In summary, a novel CP + UV device was developed, which can be used for sterilization on different food surfaces, which potentially contributes to the development of the food industries.
•Combination of CP and UV treatment was used for sterilization.•Staphylococcus aureus on the glass sheet decreased by 5.40 Log CFU/cm2 after 60s treatment.•The order of sterilization was glass sheet > OPP film > kraft paper > corrugated paper.•A novel CP + UV device was developed to sterilize different food surfaces.
•Synthesis of a low molecular weight PS incorporating a photostabilizer additive.•The synthesized copolymer was used as a macroadditive in films of PS, HIPS and ABS.•The macroadditive did not cause ...significant changes in mechanical properties.•A mitigation of UV accelerated degradation process was observed for PS and ABS films.•The macroadditive offers a promising alternative to conventional stabilizers.
Photostabilizer additives are employed to shield polymer materials from ultraviolet (UV) degradation. One category of such additives includes ultraviolet light absorbers (UVA), which absorb radiation and dissipate it within the polymer network as heat. These additives are typically incorporated into the polymer during processing, but they can pose challenges such as low miscibility and migration of the additive to the polymer's surface. A viable solution to these issues is the synthesis of polymers with additives chemically connected to the polymer chain. This work investigates the copolymerization of styrene with the additive 2-3-(2H-benzotriazol-2-yl)-4-hydroxyphenylethyl methacrylate (BHEM), resulting in the formation of PS-BHEM. This copolymer was then utilized in commercial polymers (PS, HIPS, and ABS) to mitigate degradation, with a comparative analysis of its effectiveness against the commercial stabilizer Tinuvin P. The copolymerization process yields a 92 % product, and the presence of BHEM is confirmed through SEC analysis. Accelerated weather degradation tests indicate that the incorporation of PS-BHEM enhances the UV stabilization of commercial ABS without altering the mechanical properties of the polymers.
KBe2BO3F2 (KBBF) is still the only practically usable crystal that can generate deep‐ultraviolet (DUV) coherent light by direct second harmonic generation (SHG). However, applications are hindered by ...layering, leading to difficulty in the growth of thick crystals and compromised mechanical integrity. Despite efforts, it is still a great challenge to discover new nonlinear optical (NLO) materials that overcome the layering while keeping the DUV SHG available. Now, two new DUV NLO beryllium borates have been successfully designed and synthesized, NH4Be2BO3F2 (ABBF) and γ‐Be2BO3F (γ‐BBF), which not only overcome the layering but also can be used as next‐generation DUV NLO materials with the shortest type I phase‐matching second‐harmonic wavelength down to 173.9 nm and 146 nm, respectively. Significantly, γ‐BBF is superior to KBBF in all metrics and would be the most outstanding DUV NLO crystal.
Two excellent deep‐UV nonlinear optical crystals, NH4Be2BO3F2 (ABBF) and γ‐Be2BO3F (γ‐BBF), have been synthesized based on first‐principles design. They not only effectively overcome the layering habit of KBBF, but also can generate deep‐UV (DUV) coherent light with wavelengths down to 173.9 nm and 146 nm, thus indicating that they are superior to KBBF.
Susceptibility of SARS-CoV-2 to UV irradiation Heilingloh, Christiane Silke; Aufderhorst, Ulrich Wilhelm; Schipper, Leonie ...
American journal of infection control,
10/2020, Volume:
48, Issue:
10
Journal Article
Peer reviewed
Open access
•SARS-CoV-2 is highly susceptible to irradiation with ultraviolet light.•High viral loads of 5 * 106 TCID50/ml SARS-CoV-2 can be inactivated in 9 minutes by UVC irradiation.•UVC irradiation ...represents a suitable disinfection method for SARS-CoV-2.
The coronavirus SARS-CoV-2 pandemic became a global health burden. We determined the susceptibility of SARS-CoV-2 to irradiation with ultraviolet light. The virus was highly susceptible to ultraviolet light. A viral stock with a high infectious titer of 5 × 106 TCID50/mL was completely inactivated by UVC irradiation after nine minutes of exposure. The UVC dose required for complete inactivation was 1,048 mJ/cm2. UVA exposure demonstrated only a weak effect on virus inactivation over 15 minutes. Hence, inactivation of SARS-CoV-2 by UVC irradiation constitutes a reliable method for disinfection purposes in health care facilities and for preparing SARS-CoV-2 material for research purpose.
Diamond has attracted extensive attention from many scholars because of its unique properties. However, there are still bottlenecks in how to achieve high efficiency polishing and global flattening ...of diamond which restrict its application. The aim of this study is to obtain a globally homogeneous flattened diamond surface in macro dimension by introducing a compound motion of the polished workpiece. It is shown that ultra-smooth diamond surface machining with global flattening can be realized by UV-assisted low-speed dynamic friction polishing technique, and the typical roughness is 0.175 nm as measured by 3D optical surface profiler. These experimental results demonstrate that the catalytic phase transition process of UV light is the underlying mechanism to realize the diamond surface polishing under low rotational speed conditions. Additionally, the composite motion of the diamond sample with the metal disk brings large enhancement to the effect of polishing global flattening on the sample surface. The theoretical and experimental studies in this paper provide novel ideas for achieving efficient and polished global flattening of diamond.
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•Our team previously proposed a diamond polishing technique, which was optimized and improved according to 3DM-DFP in this paper.•Ultrasmooth diamond surfaces with surface roughness Rq=0.218 nm and Ra=0.173 nm were obtained.•The comprehensive polishing mechanism is discussed, and the theory of diamond diffusion removal is expanded.•The kinematic analysis of the composite motion process was carried out, and the optimal motion parameters were theoretically obtained.
Given the high demand for miniaturized optoelectronic circuits, plasmonic devices with the capability of generating coherent radiation at deep subwavelength scales have attracted great interest for ...diverse applications such as nanoantennas, single photon sources, and nanosensors. However, the design of such lasing devices remains a challenging issue because of the long structure requirements for producing strong radiation feedback. Here, a plasmonic laser made by using a nanoscale hyperbolic metamaterial cube, called hyperbolic metacavity, on a multiple quantum‐well (MQW), deep‐ultraviolet emitter is presented. The specifically designed metacavity merges plasmon resonant modes within the cube and provides a unique resonant radiation feedback to the MQW. This unique plasmon field allows the dipoles of the MQW with various orientations into radiative emission, achieving enhancement of spontaneous emission rate by a factor of 33 and of quantum efficiency by a factor of 2.5, which is beneficial for coherent laser action. The hyperbolic metacavity laser shows a clear clamping of spontaneous emission above the threshold, which demonstrates a near complete radiation coupling of the MQW with the metacavity. This approach shown here can greatly simplify the requirements of plasmonic nanolaser with a long plasmonic structure, and the metacavity effect can be extended to many other material systems.
Deep‐ultraviolet laser action is demonstrated using a specific hyperbolic metacavity. This metacavity provides a tight mode confinement (i.e., ultrasmall mode volume) and thus increases the light–matter interactions. Meanwhile, a unique radiation flow is induced to assist the consolidation of plasmon resonances within the metacavity, which provides strong radiation feedback for laser operation.
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