Non-contact elasticity contrast imaging using photon counting.

Significance: Tissues' biomechanical properties, such as elasticity, are related to tissue health. Optical coherence elastography produces images of tissues based on their elasticity, but its performance is constrained by the laser power used, working distance, and excitation methods. Aim: We develop a new method to reconstruct the elasticity contrast image over a long working distance, with only low-intensity illumination, and by non-contact acoustic wave excitation. Approach: We combine single-photon vibrometry and quantum parametric mode sorting (QPMS) to measure the oscillating backscattered signals at a single-photon level and derive the phantoms' relative elasticity. Results: We test our system on tissue-mimicking phantoms consisting of contrast sections with different concentrations and thus stiffness. Our results show that as the driving acoustic frequency is swept, the phantoms' vibrational responses are mapped onto the photon-counting histograms from which their mechanical properties-including elasticity-can be derived. Through lateral and longitudinal laser scanning at a fixed frequency, a contrast image based on samples' elasticity can be reliably reconstructed upon photon level signals. Conclusions: We demonstrated the reliability of QPMS-based elasticity contrast imaging of agar phantoms in a long working distance, low-intensity environment. This technique has the potential for in-depth images of real biological tissue and provides a new approach to elastography research and applications.

Comparison of laser and traditional lancing devices for capillary blood sampling in patients with diabetes mellitus and high bleeding risk.

PURPOSE: Despite the importance of self-monitoring blood glucose (SMBG) for management of diabetes mellitus (DM), frequent blood sampling is discouraged by bleeding risk due to dual-antiplatelet agent therapy (DAPT) or thrombocytopenia. METHODS: We compared the bleeding time (BT) of sampling by using a laser-lancing-device (LMT-1000) and a conventional lancet in patients with DM and thrombocytopenia or patients undergoing DAPT. BT was measured using the Duke method, and pain and satisfaction scores were assessed using numeric rating scale (NRS) and visual analog scale (VAS). The consistency in the values of glucose and glycated-hemoglobin (HbA1c) sampled using the LMT-1000 or lancet were compared. RESULTS: The BT of sampling with the LMT-1000 was shorter than that with the lancet in patients with thrombocytopenia (60s vs. 85s, P = 0.024). The NRS was lower and the VAS was higher in laser-applied-sampling than lancet-applied sampling in the DAPT-user group (NRS: 1 vs. 2, P = 0.010; VAS: 7 vs. 6, P = 0.003), whereas the group with thrombocytopenia only showed improvement in the VAS score (8 vs. 7, P = 0.049). Glucose and HbA1c sampled by the LMT-1000 and lancet were significantly correlated in both the DAPT-user and the thrombocytopenia groups. CONCLUSION: The LMT-1000 can promote SMBG by shortening BT in subject with thrombocytopenia and by increasing satisfaction score, as well as by showing reliable glucose and HbA1c value.

Unusual case of Reinke's oedema.

This case report describes a man in his mid 40s, with a history of chronic smoking, who presented with dysphonia. He underwent microlaryngoscopy and biopsy for a suspicious lesion on the anterior right vocal cord. Mask ventilation proved difficult on induction of general anaesthesia due to a solid lesion acting as a ball valve into the glottis. This mass was LASER debulked and sent for histopathology. This demonstrated a haematoma, likely traumatic in origin, with some polypoidal features, consistent with advanced Reinke's oedema. Reinke's oedema is a benign condition where chronic inflammation causes fluid accumulation within the vocal cords. Long-standing inflammation leads to disarrangement of the vocal cord lamina propria, causing fluid accumulation and thereby resulting oedema of the vocal cords. This process can subsequently lead to polyp formation and can cause gravelly voice. This case report describes the potential airway sequelae of this benign condition.

Fixed-target pump-probe SFX: eliminating the scourge of light contamination.

X-ray free-electron laser (XFEL) light sources have enabled the rapid growth of time-resolved structural experiments, which provide crucial information on the function of macromolecules and their mechanisms. Here, the aim was to commission the SwissMX fixed-target sample-delivery system at the SwissFEL Cristallina experimental station using the PSI-developed micro-structured polymer (MISP) chip for pump-probe time-resolved experiments. To characterize the system, crystals of the light-sensitive protein light-oxygen-voltage domain 1 (LOV1) from Chlamydomonas reinhardtii were used. Using different experimental settings, the accidental illumination, referred to as light contamination, of crystals mounted in wells adjacent to those illuminated by the pump laser was examined. It was crucial to control the light scattering from and through the solid supports otherwise significant contamination occurred. However, the results here show that the opaque MISP chips are suitable for defined pump-probe studies of a light-sensitive protein. The experiment also probed the sub-millisecond structural dynamics of LOV1 and indicated that at Δt = 10 µs a covalent thioether bond is established between reactive Cys57 and its flavin mononucleotide cofactor. This experiment validates the crystals to be suitable for in-depth follow-up studies of this still poorly understood signal-transduction mechanism. Importantly, the fixed-target delivery system also permitted a tenfold reduction in protein sample consumption compared with the more common high-viscosity extrusion-based delivery system. This development creates the prospect of an increase in XFEL project throughput for the field.

Efficacy of photobiomodulation following L-PRF application for recovery of mental nerve neurosensory disturbances caused by genioplasty: A randomized triple-blind clinical trial.

The present study assessed the efficacy of photobiomodulation (PBM) following leukocyte-platelet rich fibrin (L-PRF) application for recovery of mental nerve neurosensory disturbances (NSDs) caused by genioplasty. This randomized triple-blind split-mouth clinical trial was conducted on 20 female patients (40 quadrants) requiring genioplasty. In each patient, one random side of the mandible served as the intervention (laser), and the other side as the control group. After genioplasty and L-PRF application, the intervention side underwent GaAIAs diode laser irradiation (880 nm, 500 mW, 15 J/cm2, 0.5 cm2 spot size, continuous-wave). Each point was laser irradiated for 15 s. Unilateral extraoral PBM was performed at 1, 3, 7, 14, 21, and 28 days, postoperatively. Laser in off mode (sham laser) was used for the control side. A visual analog scale (VAS) was used for general sensitivity, and 2-point discrimination, directional discrimination, pain discrimination, and thermal discrimination tests were used to assess the neurosensory recovery at 2 days, 2 weeks, 4 weeks, and 2 months, postoperatively. Statistical analyses were performed using two-way repeated measures ANOVA, Bonferroni test, and generalized estimating equation (alpha = 0.05). Time had a significant effect on improvement of all sensory variables (P < 0.05). Neurosensory recovery was significantly better in the intervention than the control group at all time points according to the two-point discrimination test (P = 0.0135) and brush test (P = 0.025) results. The interaction effect of time and intervention was not significant on any dependent variable (P > 0.05). Application of L-PRF + PBM resulted in significantly greater sensorineural recovery according to the two-point discrimination and brush test results.

Clinical outcomes of holmium laser enucleation of the prostate: A large prospective registry-based patient cohort study under regular follow-up protocol.

PURPOSE: To evaluate the efficacy and safety of holmium laser enucleation of the prostate (HoLEP) in a large prospective cohort of patients with benign prostatic hyperplasia (BPH) through systematic follow-up at a single institution. MATERIALS AND METHODS: Clinical outcomes were analyzed between August 2008 and June 2022. Patients were followed-up at 2 weeks, 3 months and 6 months postoperatively. RESULTS: A total of 3,000 patients (mean age, 69.6±7.7 years) underwent HoLEP. Baseline total International Prostate Symptom Score (IPSS) was 19.3±7.7 and maximum flow rate (Qmax) was 9.4±4.8 mL/s. Mean total prostate volume was 67.7±3.4 mL. Total operation time was 60.7±31.5 minutes, and catheterization time was 1.0 days (range, 1.0-1.0 days). At 6 months postoperatively, the total IPSS decreased to 6.6±5.8 and Qmax increased to 22.2±11.3 mL/s. Complications at 6 months postoperatively included stress urinary incontinence (SUI) in 36 patients (1.9%), urgency urinary incontinence (UUI) in 25 (1.3%), bladder neck contracture (BNC) requiring transurethral incision (TUI) in 16 (0.5%), and urethral stricture in 29 (1.0%). Eleven patients (0.4%) with prostatic fossa stones required stone removal. Sixty-one patients (2.0%) required secondary surgery (transurethral coagulation, 16 [0.5%]; TUI for BNC, 16 [0.5%]; stone removal for prostatic fossa stones, 11 [0.4%]; and endoscopic internal urethrotomy for urethral stricture, 18 [0.6%]). CONCLUSIONS: Mid-term follow-up results after HoLEP in BPH patients showed excellent efficacy and low complication rates. Unlike previous reports, the incidence of SUI and UUI after HoLEP was low, but the occurrence of de novo stone formation in prostatic fossa was notable.

A predicted model-aided reconstruction algorithm for X-ray free-electron laser single-particle imaging.

Ultra-intense, ultra-fast X-ray free-electron lasers (XFELs) enable the imaging of single protein molecules under ambient temperature and pressure. A crucial aspect of structure reconstruction involves determining the relative orientations of each diffraction pattern and recovering the missing phase information. In this paper, we introduce a predicted model-aided algorithm for orientation determination and phase retrieval, which has been tested on various simulated datasets and has shown significant improvements in the success rate, accuracy and efficiency of XFEL data reconstruction.

Progress and trends in photodynamic therapy research in oral science: A bibliometric analysis.

BACKGROUND: Photodynamic therapy is garnering increasing attention in oral science. Despite its promising potential, further exploration is warranted to delve into the research paradigms and evolving trends within oral science. Therefore, this study aimed to conduct a comprehensive bibliometric analysis of photodynamic therapy in oral science (PDTOS), investigating research landscapes, identifying key contributors, analyzing collaborative networks, pinpointing emerging research directions, and exploring factors influencing high citations. METHODS: Research and review articles in PDTOS were retrieved from the Web of Science Core Collection database up to December 31, 2023. The R package "bibliometrix" and VOSviewer were utilized for visualizing collaboration networks and keyword co-occurrence, alongside trend analysis. Negative binomial regression was used to model factors affecting citation counts. RESULTS: A total of 2784 articles with significant international collaboration (23.14 %) were analyzed. Brazil, China, the USA, Iran, and Italy led in publications, with predominant USA-European collaborations. The University of Sao Paulo in Brazil was the most published institution in the field. Photodiagnosis and Photodynamic Therapy was the core journal in the field and has the highest number of publications. The main research fields included photodynamic therapy, antibacterial and anticancer treatment, management, and peri­implant periodontitis, with a recent focus on peri­implantitis. Factors such as international cooperation, funding, article age, type, author count, and references significantly influenced citations. CONCLUSIONS: This research provided valuable insights into PDTOS trends and knowledge structures. These findings underscored a significant increase in the number of PDTOS publications, urging strengthened international cooperation. Emerging research has focused on peri­implantitis and nano-photosensitizer materials. Authors should consider various citation-related factors in their research endeavors.

Hard X-ray operation of X-ray gas monitors at the European XFEL.

X-ray gas monitors (XGMs) are operated at the European XFEL for non-invasive single-shot pulse energy measurements and average beam-position monitoring. The underlying measurement principle is the photo-ionization of rare gas atoms at low gas pressures and the detection of the photo-ions and photo-electrons created. These are essential for tuning and sustaining self-amplified spontaneous emission (SASE) operation, machine radiation safety, and sorting single-shot experimental data according to pulse energy. In this paper, the first results from XGM operation at photon energies up to 30 keV are presented, which are far beyond the original specification of this device. Here, the Huge Aperture MultiPlier (HAMP) is used for single-shot pulse energy measurements since the standard X-ray gas monitor detectors (XGMDs) do not provide a sufficient signal-to-noise ratio, even at the highest operating gas pressures. A single-shot correlation coefficient of 0.98 is measured between consecutive XGMs operated with HAMP, which is as good as measuring with the standard XGMD detectors. An intra-train non-linearity of the HAMP signal is discovered, and operation parameters to mitigate this effect are studied. The upper repetition rate limit of HAMP operation at 2.25 MHz is also determined. Finally, the possibilities and limits for future XGM operation at photon energies up to 50 keV are discussed.

Enhanced X-ray free-electron laser performance with optical klystron and helical undulators.

This article presents a demonstration of the improved performance of an X-ray free-electron laser (FEL) using the optical klystron mechanism and helical undulator configuration, in comparison with the common planar undulator configuration without optical klystron. The demonstration was carried out at Athos, the soft X-ray beamline of SwissFEL. Athos has variable-polarization undulators, and small magnetic chicanes placed between every two undulators to fully exploit the optical klystron. It was found that, for wavelengths of 1.24 nm and 3.10 nm, the required length to achieve FEL saturation is reduced by about 35% when using both the optical klystron and helical undulators, with each effect accounting for about half of the improvement. Moreover, it is shown that a helical undulator configuration provides a 20% to 50% higher pulse energy than planar undulators. This work represents an important step towards more compact and high-power FELs, rendering this key technology more efficient, affordable and accessible to the scientific community.

Cutaneous Sarcoidosis Induced by Laser Therapy: Case Report and Review of the Literature.

BACKGROUND: Sarcoidosis, characterized by non-caseating epithelioid granulomas, presents diagnostic and therapeutic challenges. METHOD: Here we present a 38-year-old woman who exhibited erythematous and infiltrated skin lesions on her facial region following fractional laser treatment. RESULTS: Histological analysis confirmed cutaneous sarcoidosis. Initial interventions with topical clobetasol and oral chloroquine provided transient relief. Subsequent outpatient management comprised topical tacrolimus and clobetasol, as well as systemic methotrexate, later substituted with prednisone. Gradual tapering resulted in lesion reduction. CONCLUSIONS: This case underscores the intricate nature of cutaneous sarcoidosis and the necessity for personalized therapeutic approaches. The association with cosmetic procedures highlights the importance of understanding potential triggers. The presented case highlights and reminds the medical community that lasers are not only used for therapeutic purposes but can also induce specific responses through laser therapy. Notably, while laser therapy is frequently employed in treating cutaneous sarcoidosis, its role in inducing sarcoidosis warrants further investigation.

Power Enhancement and Spot Homogenization Design for Arrayed Semiconductor Lasers.

Improving the spot brightness and uniformity of arrangement of the array laser is conducive to ensuring the beam quality of the fiber laser. Based on the light tracing principle, the optical model performance of two common fiber lasers was first analyzed. Then, a novel rotationally polarized optical model with high power and spot uniformity was designed and optimized on the basis of the aforementioned analysis. The results of the evaluation metrics of the multi-indicator optical model show that the spot uniformity of our proposed model improved by 24.03%, the power improved by 0.55%, and the maximum light distance was shortened from 120 mm to 82.58 mm. Further, the results of the coupling tolerance analysis of the optical elements show that the total coupling efficiency was 89.04%. The coupling power and tolerance relationships did not produce degradation compared with the traditional model. Extensive comparative results show that the designed rotationally polarized optical path model can effectively improve the optical coupling efficiency and spot uniformity of arrayed semiconductor lasers.

Complications of dermatologic lasers in high Fitzpatrick phototypes and management: an updated narrative review.

This article explores the intricacies of laser surgery, acknowledging inherent risks and complications. Patients with higher Fitzpatrick phototypes, characterized by unique biological traits, face heightened vulnerability during laser treatments. Limited experience with darker skin tones necessitates a higher level of laser expertise and a conservative approach. The study aims to comprehensively review laser therapy's side effects and complications, with a specific focus on Fitzpatrick phototypes IV through VI. We searched the MEDLINE database from 1972 to 2023 to consolidate knowledge. Results illuminate nuanced challenges associated with laser surgery in higher phototypes. In conclusion, this research emphasizes the need for enhanced expertise and caution in laser procedures for individuals with darker skin, offering valuable insights to optimize patient safety and outcomes.

Reversal of Peripheral Anterior Synechiae After Trabeculectomy With Argon Laser Synechiolysis.

We report a case of successful argon laser synechiolysis as a non-invasive alternative for peripheral anterior synechiae release after trabeculectomy in a young patient with steroid-induced ocular hypertension. Steroid-induced ocular hypertension is a known complication of vernal keratoconjunctivitis due to prolonged treatment with steroids. In refractive conditions, augmented trabeculectomy becomes the surgery of choice in these patients. In this article, we report successful treatment of iris tissue plugging the internal ostium with an argon laser and reinstatement of aqueous flow.

Management of androgenic alopecia: a systematic review of the literature.

We aimed to determine the efficacy of the various available oral, topical, and procedural treatment options for hair loss in individuals with androgenic alopecia. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review of the National Library of Medicine was performed. Overall, 141 unique studies met our inclusion criteria. We demonstrate that many over the counter (e.g. topical minoxidil, supplements, low-level light treatment), prescription (e.g. oral minoxidil, finasteride, dutasteride), and procedural (e.g. platelet-rich plasma, fractionated lasers, hair transplantation) treatments successfully promote hair growth, highlighting the superiority of a multifaceted and individualized approach to management.

Comparison of conventional (basketing + dusting) and Moses (pop-dusting) holmium lasers during flexible ureteroscopy in the treatment of renal stones between 2 and 3 cm: a randomized clinical trial.

To investigate the feasibility of conventional (basketing + dusting) and Moses (pop-dusting) holmium lasers during flexible ureteroscopy (FURS) in the treatment of 2-3 cm renal calculi and to compare the efficiency and safety of the two methods, a total of 230 patients with 2-3 cm kidney stones who underwent FURS were randomly divided into the conventional group and the Moses group. The mode of lithotripsy in the conventional group was fragmentation and dusting. The mode of lithotripsy in the Moses group was dusting and pop-dusting. Clinical and perioperative variables and complications were compared between the two cohorts. Multivariate analyses of factors contributing to the stone-free rate (SFR) and operation time were performed. No statistically significant differences were found in the demographics, renal stone-related data, SFR, or complications between the cohorts. The laser energy was higher in the Moses cohort than in the conventional cohort (119.3 ± 15.2 vs. 92.8 ± 15.1 kJ; P < 0.001), and the operation time was shorter in the Moses cohort than in the conventional cohort (99.5 ± 18.9 vs. 105.3 ± 13.7 min; P = 0.009). When there was isolated stone, the operation time was shorter in the Moses cohort than in the conventional cohort (99.6 ± 17.5 vs. 111.4 ± 10.7 min; P < 0.001), while there was no significant difference between the two cohorts when there were multiple stones (99.5 ± 20 vs. 101.2 ± 14 min; P = 0.415). Multivariate analyses found that an increase in stone volume can decrease the SFR and prolong the operation time, and use of a Moses laser can shorten the operation time. Both holmium laser modes during FURS can effectively treat 2-3 cm renal calculi. The Moses mode is recommended as the first choice for the treatment of isolated 2-3 cm renal stones. When treating multiple stones, the efficiency of these two laser modalities is the same. TRIAL REGISTRATION: ChiCTR2200056091.

Laser and Lights in Psoriasis.

Psoriasis is a chronic inflammatory skin condition affecting millions of individuals worldwide. Over the years, various treatment modalities have been explored to alleviate the symptoms and improve the quality of life for patients with psoriasis. Among these treatment options, lasers and lights have emerged as promising non-invasive approaches with significant efficacy. This review aims to provide an overview of the current understanding and clinical applications of lasers and lights in the management of psoriasis. We have discussed the mechanisms of action behind different laser and light therapies and their impact on psoriatic plaques. Additionally, we discuss the various types of lasers and lights utilized, including excimer lasers, pulsed dye lasers, and narrowband ultraviolet B (NB-UVB) phototherapy, highlighting their unique properties and clinical outcomes. Moreover, we have addressed important considerations related to patient selection, treatment protocols, and potential side effects associated with lasers and lights. We emphasize the need for proper evaluation, monitoring, and customization of treatment plans to ensure optimal outcomes and minimize adverse events.