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The Analyst Oct 2023We report a fiber optofluidic laser (FOFL) using an RhB-doped ionic liquid (BmimPF) as the gain medium and explore its application for large dynamic range highly...
We report a fiber optofluidic laser (FOFL) using an RhB-doped ionic liquid (BmimPF) as the gain medium and explore its application for large dynamic range highly sensitive pH sensing. Due to the high -factor of the FOFL and the unique merits of BmimPF, lasing emission presents a threshold of only 0.61 μJ mm. Particularly, lasing emission behaviors are strongly dependent on the pH value of the gain medium, , in the pH range 4.28-6.37, the lasing central wavelength blue-shifts monotonically with a sensitivity as high as 5.02 nm per pH unit, which we attribute to the conversion of the cationic form of RhB to the zwitterionic form caused by the deprotonation of the COOH group. Under alkaline conditions (pH 7.20-11.17), the lasing emission intensity exhibits a significant decrease and the corresponding lasing central wavelength is also blue-shifted due to the solvent effect. The sensitivity based on the wavelength shift is 3.03 nm per pH unit, which is 4-fold higher than that of fluorescence-based sensing, while the sensitivity based on the variation of the lasing emission intensity is almost three orders of magnitude higher than that of fluorescence-based sensing. Our work presents a novel dual sensing paradigm in response to different pH conditions, which can greatly improve the reliability and discrimination of pH sensing.
PubMed: 37668015
DOI: 10.1039/d3an01156a -
ACS Omega Aug 2023The degradation of organic dye pollutants is a critical environmental issue that has garnered significant attention in recent years. To address this problem, we...
The degradation of organic dye pollutants is a critical environmental issue that has garnered significant attention in recent years. To address this problem, we investigated the potential of CaCrO chromite (CCO) as a photocatalyst for the degradation of cationic and anionic dye solutions under sunlight irradiation. CaCrO was synthesized via a sol-gel auto-combustion route and sintered at 900 °C. The Rietveld refined XRD profile confirmed the zircon-type structure of CaCrO crystallized in the tetragonal unit cell with 41/ space group symmetry. The surface morphology of the sample was investigated by field emission scanning electron microscopy (FESEM), which revealed the polyhedral texture of the grains. Energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) studies were carried out to analyze the elemental composition and chemical states of the ions present in the compound. Fourier transform infrared (FT-IR) spectroscopy analysis revealed the vibrational modes corresponding to the tetrahedral and dodecahedral metal oxide bonds. The optical band gap was approximated to be in the range of 1.928 eV by using the Tauc relation. The CaCrO catalyst with different contents (5, 20, 35, and 50 mg) was investigated for its photocatalytic performance for the degradation of RhB dye solution under sunlight irradiation using a UV-Vis spectrometer over the experimental wavelength range of 450-600 nm. The degradation efficacy increased from 70.630 to 93.550% for 5-35 mg and then decreased to 68.720% for 50 mg in 140 min under visible light illumination. The comparative study demonstrates that a higher degradation rate was achieved for cationic than anionic dyes in the order RhB > MB > MO. The highest deterioration (93.80%) was achieved for the RhB dye in 140 min. Equilibrium and kinetic studies showed that the adsorption process followed the Langmuir isotherm and pseudo-second-order models, respectively. The maximum adsorption capacity of 21.125 mg/g was observed for the catalyst concentration of 35 mg. From the cyclic test, it has been observed that the synthesized photocatalyst is structurally and morphologically stable and reusable. The radical trapping experiment demonstrated that superoxide and hydroxyl radicals were the primary species engaged in the photodegradation process. A possible mechanism for the degradation of RhB has been proposed. Hence, we conclude that CaCrO can be used as an efficient photocatalyst for the remediation of organic dye pollutants from the environment.
PubMed: 37636959
DOI: 10.1021/acsomega.3c02457 -
Skin Research and Technology : Official... Aug 2023The Flash-lamp pulsed dye laser (FPDL) is nowadays considered the most precise laser currently on the market for treating superficial vascular lesions. In this study, we...
INTRODUCTION
The Flash-lamp pulsed dye laser (FPDL) is nowadays considered the most precise laser currently on the market for treating superficial vascular lesions. In this study, we gathered data from 10 years of experience regarding dye laser treatment of patients presenting vascular malformations such as telangiectasia, rhinophyma, port-wine stain, cherry and spider angioma and vascular tumours.
METHODS
Subjects were enrolled from 2013 to 2023 based on the vascular anomalies they presented. They underwent different treatment sessions with the FPDL device.
RESULTS
The age-range distribution by vascular anomaly confirmed that haemangiomas are typical in children while rhinophyma is a condition very common in older adults. A difference in sex distribution showed that pathologies such as telangiectasias typically affect women whereas rhinophyma is more frequent in men. Most of the treatments interested the face area but no permanent side effects were registered.
CONCLUSIONS
Our 10 years of experience with FPDL demonstrated good results in a wide range of applications for the treatment of different vascular anomalies. The absence of long-term side effects and bearable pain during the treatment makes it a valuable solution for the resolution of benign tumours also in very young patients.
Topics: Female; Humans; Male; Lasers, Dye; Retrospective Studies; Rhinophyma; Hemangioma; Vascular Malformations
PubMed: 37632184
DOI: 10.1111/srt.13427 -
Lab on a Chip Sep 2023Flow-based microfluidic biochips (FMBs) have been rapidly commercialized and deployed in recent years for biological computing, clinical diagnostics, and...
Flow-based microfluidic biochips (FMBs) have been rapidly commercialized and deployed in recent years for biological computing, clinical diagnostics, and point-of-care-tests (POCTs). However, outsourcing FMBs makes them susceptible to material-level attacks by malicious actors for illegitimate monetary gain. The attacks involve deliberate material degradation of an FMB's polydimethylsiloxane (PDMS) components by either doping with reactive solvents or altering the PDMS curing ratio during fabrication. Such attacks are stealthy enough to evade detection and deteriorate the FMB's function. Furthermore, material-level attacks can become prevalent in attacks based on intellectual property (IP) theft, such as counterfeiting, overbuilding, , which involve unscrupulous third-party manufacturers. To address this problem, we present a dynamic material-level watermarking scheme for PDMS-based FMBs with microvalves using a perylene-labeled fluorescent dye. The dyed microvalves show a unique excimer intensity peak under 405 nm laser excitation. Moreover, when pneumatically actuated, the peak shows a predetermined downward shift in intensity as a function of mechanical strain. We validated this protection scheme experimentally using fluorescence microscopy, which showed a high correlation ( = 0.971) between the normalized excimer intensity change and the maximum principal strain of the actuated microvalves. To detect curing ratio-based attacks, we adapted machine learning (ML) models, which were trained on the force-displacement data obtained from a mechanical punch test method. Our ML models achieved more than 99% accuracy in detecting curing ratio anomalies. These countermeasures can be used to proactively safeguard FMBs against material-level attacks in the era of global pandemics and diagnostics based on POCTs.
Topics: Microfluidics; Dimethylpolysiloxanes; Fluorescent Dyes; Lasers
PubMed: 37605818
DOI: 10.1039/d3lc00335c -
Journal of Lasers in Medical Sciences 2023Despite the advanced formulations of resin composites, microleakage is still among the commonest causes of clinical failure of these restorations. We evaluated the...
Despite the advanced formulations of resin composites, microleakage is still among the commonest causes of clinical failure of these restorations. We evaluated the effect of surface coating and laser pretreatment on the microleakage of Class V resin composite restorations in primary teeth. Sixty extracted primary molar teeth having intact lingual or facial surfaces were randomly allocated into the control, G-Coat Plus surface coating, and erbium-doped yttrium aluminum garnet (Er:YAG) laser pretreatment groups. Class V cavities were provided with the coronal and gingival margins in the dentin and enamel, respectively. Restoration of the cavities was done with Z250 resin composite and they were thermocycled, followed by immersing in 2% basic Fuchsin dye for 24 hrs. Samples underwent sectioning occlusogingivally and the microleakage was assessed under a stereomicroscope (40×). Statistical analysis was done via SPSS and Kruskal-Wallis test (α=0.05). The control and G-Coat plus groups were significantly different regarding the microleakage (<0.001), and G-Coat Plus and laser pretreatment groups (<0.001) at both gingival and occlusal margins. However, it showed no significant difference between the laser and the control group on the enamel (=0.063) and dentin margins (=0.757). Microleakage at the gingival margins was significantly greater compared to the occlusal margins in the control and laser groups (<0.001), but not in the G-Coat Plus group (=0.051). G-Coat plus coating significantly reduced microleakage at dentin and enamel margins of Class V composite restorations in primary teeth, in comparison with other groups of the study. Also, dentin margins showed more significant amounts of microleakage versus enamel margins in all groups, except for the G-Coat Plus group.
PubMed: 37583502
DOI: 10.34172/jlms.2023.11 -
Pediatric Dermatology 2024Port wine birthmarks (PWB) are capillary vascular malformations within the papillary and reticular dermis, most commonly occurring on the head and neck and may darken...
Port wine birthmarks (PWB) are capillary vascular malformations within the papillary and reticular dermis, most commonly occurring on the head and neck and may darken and thicken with age. Pulsed dye laser (PDL) is the gold standard of treatment for PWB as it selectively targets involved vessels. Sirolimus is a macrolide antibiotic that selectively inhibits mammalian target of rapamycin, thereby suppressing the angiogenesis pathways that can be activated by PDL. Sirolimus and PDL may be used together to treat PWB. We present a case series describing three cases of delayed ulceration and systemic sirolimus absorption following combination therapy, highlighting a potential complication and patient safety concern.
Topics: Humans; Sirolimus; Lasers, Dye; Immunosuppressive Agents; Port-Wine Stain; Administration, Topical; Treatment Outcome; Laser Therapy; Capillaries; Vascular Malformations
PubMed: 37571864
DOI: 10.1111/pde.15409 -
Journal Der Deutschen Dermatologischen... Oct 2023
Topics: Humans; Port-Wine Stain; Lasers, Dye; Laser Therapy; Health Services; Germany; Treatment Outcome
PubMed: 37550854
DOI: 10.1111/ddg.15181 -
Polymers Jul 2023Due to the increased application of lasers in different fields (industry, medicine, etc.), there is a growing need for new laser sources with good beam quality and...
Due to the increased application of lasers in different fields (industry, medicine, etc.), there is a growing need for new laser sources with good beam quality and variable emission wavelength. At the same time, for environmental reasons, the obtaining of novel eco-friendly active optical materials, such as those based on the deoxyribonucleic acid (DNA) biopolymer, with optimal light emission properties, is of high interest. The results obtained in this study of the temporal dependence of the transmittance and of the light emission in thin films of DNA-CTMA-Rhodamine 610 (at different Rhodamine concentrations) (DNA-CTMA-Rh610), when they are illuminated with continuous wave laser light at 532 nm (frequently used in the optical pumping of dye lasers), are presented and discussed. The transmittance results obtained for thin film samples are compared to those obtained for the DNA-CTMA-Rh610 solutions in butanol, from which the films have been made, and also with those obtained for Rh610 solutions in butanol with the same concentrations. The investigation was performed in order to assess the influence of the DNA-CTMA and of the green laser light at 532 nm wavelength on relevant chromophore properties such as light transmission and fluorescence emission. The results obtained revealed that the DNA-CTMA matrix has an active influence on the Rhodamine 610 emission, in the whole range of concentrations of the investigated samples.
PubMed: 37514494
DOI: 10.3390/polym15143105