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Micromachines Dec 2023Optofluidic dye lasers integrated into microfluidic chips are promising miniature coherent light sources for biosensing. However, achieving the accurate and efficient...
Optofluidic dye lasers integrated into microfluidic chips are promising miniature coherent light sources for biosensing. However, achieving the accurate and efficient tuning of lasers remains challenging. This study introduces a novel pneumatically tunable optofluidic distributed feedback (DFB) dye laser in a multilayer microfluidic chip. The dye laser device integrates microfluidic channels, grating structures, and vacuum chambers. A second-order DFB grating configuration is utilized to ensure single-mode lasing. The application of vacuum pressure to the chambers stretches the soft grating layer, enabling the sensitive tuning of the lasing wavelength at a high resolution of 0.25 nm within a 7.84 nm range. The precise control of pressure and laser tuning is achieved through an electronic regulator. Additionally, the integrated microfluidic channels and optimized waveguide structure facilitate efficient dye excitation, resulting in a low pump threshold of 164 nJ/pulse. This pneumatically tunable optofluidic DFB laser, with its high-resolution wavelength tuning range, offers new possibilities for the development of integrated portable devices for biosensing and spectroscopy.
PubMed: 38258186
DOI: 10.3390/mi15010068 -
BioRxiv : the Preprint Server For... Jul 2023The small size and flexibility of G protein-coupled receptors (GPCRs) have long posed a significant challenge to determining their structures for research and...
The small size and flexibility of G protein-coupled receptors (GPCRs) have long posed a significant challenge to determining their structures for research and therapeutic applications. Single particle cryogenic electron microscopy (cryoEM) is often out of reach due to the small size of the receptor without a signaling partner. Crystallization of GPCRs in lipidic cubic phase (LCP) often results in crystals that may be too small and difficult to analyze using X-ray microcrystallography at synchrotron sources or even serial femtosecond crystallography at X-ray free electron lasers. Here, we determine the previously unknown structure of the human vasopressin 1B receptor (V1BR) using microcrystal electron diffraction (MicroED). To achieve this, we grew V1BR microcrystals in LCP and transferred the material directly onto electron microscopy grids. The protein was labeled with a fluorescent dye prior to crystallization to locate the microcrystals using cryogenic fluorescence microscopy, and then the surrounding material was removed using a plasma-focused ion beam to thin the sample to a thickness amenable to MicroED. MicroED data from 14 crystalline lamellae were used to determine the 3.2 Å structure of the receptor in the crystallographic space group 1. These results demonstrate the use of MicroED to determine previously unknown GPCR structures that, despite significant effort, were not tractable by other methods.
PubMed: 37461729
DOI: 10.1101/2023.07.05.547888 -
The Journal of Dermatological Treatment Dec 2023Although pulsed dye laser (PDL) is the treatment of choice for port-wine stains (PWS), clinical resistance to PDL has been observed in 20-30% of cases. Several... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Although pulsed dye laser (PDL) is the treatment of choice for port-wine stains (PWS), clinical resistance to PDL has been observed in 20-30% of cases. Several alternative treatment modalities have been introduced; however, there is still a lack of definite recommendations regarding the optimal treatment for difficult-to-treat PWS.
OBJECTIVE
We aimed to systematically review and analyze the comparative effectiveness among treatments for problematic PWS.
METHODS & MATERIALS
We systematically searched for comparative studies assessing treatments for patients with difficult-to-treat PWS through relevant biomedical databases until August 2022. A Network Meta-Analysis (NMA) was conducted to estimate the odds ratio (OR) for all pairwise comparisons. The primary outcome is the improvement of lesions of more than 25%.
RESULTS
Of the 2498 studies identified, six treatments from five studies were available for NMA. Compared with 585 nm short-pulsed dye laser (SPDL), intense pulsed light (IPL) was the most effective in clearing lesions (OR 11.81, 95% CI 2.15 to 64.89, very low confidence rating), followed by 585 nm long-pulsed dye laser (LPDL) (OR 9.95, 95% CI 1.75 to 56.62, very low confidence rating). The 1064 nm NdYAG, 532 nm NdYAG, and LPDL >585 nm exhibited potential superiority over SPDL 585 nm, although statistical significance was not observed.
CONCLUSIONS
IPL and 585 nm LPDL are likely to be more effective than 585 nm SPDL for treating difficult-to-treat PWS. Well-designed clinical trials are warranted to confirm our findings.
Topics: Humans; Lasers, Dye; Low-Level Light Therapy; Network Meta-Analysis; Port-Wine Stain; Treatment Outcome
PubMed: 37424384
DOI: 10.1080/09546634.2023.2231582 -
Scientific Reports Oct 2023Integrated optofluidic devices have become subjects of high interest for rapid biosensor devices due to their unique ability to combine the fluidic processing of small...
Integrated optofluidic devices have become subjects of high interest for rapid biosensor devices due to their unique ability to combine the fluidic processing of small volumes of microfluidics with the analysis capabilities of photonic structures. By integrating dynamically reconfigurable optofluidic lasers on-chip, complex coupling can be eliminated while further increasing the capabilities of sensors to detect an increasing number of target biomarkers. Here, we report a polydimethylsiloxane-based device with two on-chip fluidic distributed feedback (DFB) laser cavities that are integrated with an orthogonal analyte channel for multiplexed fluorescence excitation. One DFB grating is filled with 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran dissolved in dimethyl sulfoxide. The second grating is filled with rhodamine 6G dissolved in a diluted ethylene glycol solution. We present characterization of both lasers through analysis of the lasing spectra for spectral narrowing along with a power series to observe threshold behavior. We then demonstrate simultaneous detection of two different fluorescent microbeads as a proof of concept for scalable, single biomarker analysis using on-chip optofluidic lasers.
Topics: Humans; Lasers, Dye; Feedback; Optics and Photonics; Coloring Agents; Microfluidics
PubMed: 37803034
DOI: 10.1038/s41598-023-42671-4 -
Optics Letters Sep 2023Stable and miniaturized orange lasers at 591 nm are in urgent demand for ophthalmology and dermatological treatment. However, at present, traditional dye lasers and...
Stable and miniaturized orange lasers at 591 nm are in urgent demand for ophthalmology and dermatological treatment. However, at present, traditional dye lasers and nonlinear sum-frequency lasers are limited by their complex setup and high cost, whereas semiconductor laser diodes (LDs) emitting in the yellow-orange range suffer from low output power. Here, we propose a new, to the best of our knowledge, route to create self-frequency-doubling (SFD) orange laser with a combination of multiphonon-assisted lasing and nonlinear frequency-doubling in one crystal. Using Yb-doped YCaO(BO) (Yb:YCOB) crystal, we first realize a widely tunable laser beyond the fluorescence spectrum in the wavelength range of 1175-1248 nm. Then, by selecting the laser polarization and crystal angle to satisfy phase-matching conditions, we obtained a directly diode-pumped orange laser at 591.8 nm with 3.07-W output power and an optical-to-optical conversion efficiency of 13%. This work represents a new step forward for portable high-power solid-state orange lasers and provides an intriguing platform for electron-phonon coupled lasing.
PubMed: 37707935
DOI: 10.1364/OL.501045 -
Skin Research and Technology : Official... Oct 2023Studies on pulsed dye laser (PDL) have shown the best efficacy and safety data for treating vascular anomalies among the various lasers used and the 595-nm PDL has been...
BACKGROUND
Studies on pulsed dye laser (PDL) have shown the best efficacy and safety data for treating vascular anomalies among the various lasers used and the 595-nm PDL has been used to treat cutaneous vascular anomalies for about 30 years. The purpose of this study was to assess the efficacy of 595 nm Pulsed Dye Laser in the management of facial flat angiomas present in the form of Port-Wine Stain.
MATERIALS AND METHODS
Seven cases of PWS in Fitzpatrick skin type ranged from I to III and colour ranging from pink to purple, were treated with 595 nm pulse Dye Laser. Patients underwent to 6-8 laser sessions at 20-30 days intervals. Results obtained were judged by dermatologist, by comparing pre-treatment and post-treatment photographs, 6 months after the last session and a quartile scale of lesion clearance (4-point Investigator Global Assessment scale): 1 = no or low results (0%-25% of the lesion area improved), 2 = slight improvement (25%-50% of the lesion area cleared), 3 = moderate-good improvement (50%-75%), and 4 = excellent improvement (75%-100%) was used. Possible side effects such as blisters, hyper/hypopigmentation, and scarring were monitored.
RESULTS
All patients observed global improvements. 71% of patients achieved excellent clearance and 29% patients achieved good-moderate clearance of their angioma. Patients were asked for a subjective evaluation of the results: 57% of patients were very satisfied, 29% were satisfied, and 14% patients were not very satisfied with the results. No patients were dissatisfied. No significant side effects were noted.
CONCLUSION
This research confirms the efficacy of the 595 nm PDL for flat angioma management, without considerable side effects.
Topics: Humans; Treatment Outcome; Lasers, Dye; Port-Wine Stain; Cicatrix; Hemangioma
PubMed: 37881052
DOI: 10.1111/srt.13494 -
JAMA Dermatology Jun 2024Early treatment of port-wine birthmark (PWB) can be life-altering and is often associated with improved outcomes and quality of life. There is growing evidence that...
IMPORTANCE
Early treatment of port-wine birthmark (PWB) can be life-altering and is often associated with improved outcomes and quality of life. There is growing evidence that shorter treatment intervals may play a role in more rapid PWB clearance; however, the optimal treatment interval has not been established.
OBJECTIVE
To describe the outcomes of once-weekly pulsed dye laser (PDL) treatments for PWB in infants.
DESIGN, SETTING, AND PARTICIPANTS
This case series analyzed the medical records of patients with PWB who received once-weekly PDL treatments between January 1, 2022, and December 31, 2023, at the Laser & Skin Surgery Center of New York. These patients were younger than 6 months. Before-and-after treatment photographs were independently assessed and graded 2 months after initiation of treatment.
INTERVENTION
Once-weekly PDL treatments.
MAIN OUTCOMES AND MEASURES
The primary outcome was the percentage improvement of PWB, which was graded using the following scale: 0% (no improvement), 1% to 25% (mild improvement), 26% to 50% (moderate improvement), 51% to 75% (marked improvement), 76% to 95% (near-total clearance), and 96% to 100% (total clearance).
RESULTS
Of the 10 patients (6 males [60%]; median [range] age at first treatment, 4 [<1 to 20] weeks) included, 7 (70%) had experienced either near-total clearance (76%-95%) or total clearance (96%-100%) of their PWB with once-weekly PDL treatments after 2 months. The other 3 patients all saw marked improvement (51%-75%) and subsequently went on to achieve near-total clearance with additional treatments. The median (range) duration of treatment and number of treatments to achieve near-total or total clearance in all patients were 2 (0.2-5.1) months and 8 (2-20) treatments, respectively. No adverse events were noted.
CONCLUSION AND RELEVANCE
This case series found that once-weekly PDL treatments for PWB in the first few months of life was associated with near-total or total clearance of PWB with no reported adverse events, suggesting improved outcomes can be achieved with shorter overall treatment duration. Further investigation into this novel decreased treatment interval of 1 week is warranted.
Topics: Humans; Port-Wine Stain; Lasers, Dye; Infant; Male; Female; Treatment Outcome; Retrospective Studies; Infant, Newborn; Time Factors; Quality of Life; Low-Level Light Therapy
PubMed: 38630490
DOI: 10.1001/jamadermatol.2024.0293 -
Experimental Dermatology Jul 2023Pulsed dye laser (PDL) therapy can be effective in treating psoriasis, with a long duration of remission. Although PDL therapy, albeit on a modest scale, is being used...
Pulsed dye laser (PDL) therapy can be effective in treating psoriasis, with a long duration of remission. Although PDL therapy, albeit on a modest scale, is being used for decades now, the underlying mechanisms responsible for the long-term remission of psoriasis remain poorly understood. The selective and rapid absorption of energy by the blood causes heating of the vascular wall and surrounding structures, like perivascular nerves. Several studies indicate the importance of nerves in psoriatic inflammation. Interestingly, denervation leads to a spontaneous remission of the psoriatic lesion. Among all dermal nerves, the perivascular nerves are the most likely to be affected during PDL treatment, possibly impairing the neuro-inflammatory processes that promote T-cell activation, expression of adhesion molecules, leukocyte infiltration and cytokine production. Repeated PDL therapy could cause a prolonged loss of innervation through nerve damage, or result in a 'reset' of neurogenic inflammation after temporary denervation. The current hypothesis provides strong arguments that PDL treatment affects nerve fibres in the skin and thereby abrogates the persistent and exaggerated inflammatory process underlying psoriasis, causing a long-term remission of psoriasis.
Topics: Humans; Lasers, Dye; Treatment Outcome; Psoriasis; Skin; Low-Level Light Therapy
PubMed: 37083107
DOI: 10.1111/exd.14816 -
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 -
Nano Letters Apr 2024Hampered by their susceptibility to nucleophilic attack and chemical bleaching, electron-deficient squaraine dyes have long been considered unsuitable for biological...
Hampered by their susceptibility to nucleophilic attack and chemical bleaching, electron-deficient squaraine dyes have long been considered unsuitable for biological imaging. This study unveils a surprising twist: in aqueous environments, bleaching is not irreversible but rather a reversible spontaneous quenching process. Leveraging this new discovery, we introduce a novel deep-red squaraine probe tailored for live-cell super-resolution imaging. This probe enables single-molecule localization microscopy (SMLM) under physiological conditions without harmful additives or intense lasers and exhibits spontaneous blinking orchestrated by biological nucleophiles, such as glutathione or hydroxide anion. With a low duty cycle (∼0.1%) and high-emission rate (∼6 × 10 photons/s under 400 W/cm), the squaraine probe surpasses the benchmark Cy5 dye by 4-fold and Si-rhodamine by a factor of 1.7 times. Live-cell SMLM with the probe reveals intricate structural details of cell membranes, which demonstrates the high potential of squaraine dyes for next-generation super-resolution imaging.
PubMed: 38588010
DOI: 10.1021/acs.nanolett.4c00595