Temporal and Spatial Distribution Characteristics of Crosstalk Lines Generated by Irradiating Progressive Scan Charge-Coupled Device Camera with Continuous Laser.

To study the interference effect of the laser in motion mode on a CCD, the continuous laser with the wavelength of 532 nm at different motion speeds was used to scan the CCD. The experimental results show that the crosstalk phenomenon produced by static and dynamic irradiation is significantly different. When the continuous laser statically radiates the CCD, the vertical crosstalk line is observed in the output image. The gray values of the crosstalk line are divided into two stages, with the increase of the laser fluence: linear increase and saturation, which correspond to different formation mechanisms of the crosstalk lines, respectively. In addition, when the irradiation duration of the static laser is less than the integration time of CCD, the effect of delay time on the spatial distribution of the crosstalk line is identified. In addition, when the laser irradiates the CCD at different scanning speeds, crosstalk lines with certain slopes are observed. The slope of the crosstalk line is determined by the scanning speed of the continuous laser and the integration time of the CCD. The results show that the delay time and the irradiation position have important effects on the spatial distribution of the laser spot and crosstalk lines.

Continuous Laser Versus Micropulse Laser in the Treatment of Central Serous Chorioretinopathy: A Retrospective Study.

BACKGROUND: Central serous chorioretinopathy (CSCR) is a retinal disorder characterized by complex mechanisms leading to abnormal fluid accumulation under the retina. While management remains controversial, laser therapy has been successfully used. This study compares the efficacy of continuous laser (CL) and micropulse laser (ML) therapy in treating CSCR, focusing on reduction in macular thickness and improvement in visual acuity. METHODS: A retrospective cohort study was conducted, including patients with CSCR treated with either CL or ML. The primary outcome measured was the reduction in average macular thickness (AMT), alongside secondary outcomes like changes in best corrected visual acuity (BCVA), subfoveal choroidal thickness (SFCT), and resolution of subretinal fluid (SRF). RESULTS: The study evaluated 121 patients with CSCR, treated either with CL or ML. The primary outcome showed that the mean reduction in AMT was 51.14 µm (±20) in the CL group and 29.88 µm (±22) in the ML group, without a statistically significant difference (p=0.10). For the secondary outcomes, the improvement in BCVA was comparable in both groups, with CL at 0.15 (±0.1) and ML at 0.12 (±0.1) and no significant difference (p=0.41). However, in SFCT reduction, CL showed greater efficacy with a mean reduction of 32.19 µm (±15) compared to ML's 4.85 µm (±18), which was statistically significant (p=0.0004). The degree of SRF resolution showed no significant difference between the treatments (p=0.065). CONCLUSIONS: Both CL and ML are effective in the management of CSCR, with CL being more effective in reducing SFCT. These findings suggest the need for personalized treatment strategies based on individual patient characteristics and underline the complexity of CSCR management.

Rapid Fabrication of High-Performance Flexible Pressure Sensors Using Laser Pyrolysis Direct Writing.

The fabrication of flexible pressure sensors with low cost, high scalability, and easy fabrication is an essential driving force in developing flexible electronics, especially for high-performance sensors that require precise surface microstructures. However, optimizing complex fabrication processes and expensive microfabrication methods remains a significant challenge. In this study, we introduce a laser pyrolysis direct writing technology that enables rapid and efficient fabrication of high-performance flexible pressure sensors with a micro-truncated pyramid array. The pressure sensor demonstrates exceptional sensitivities, with the values of 3132.0, 322.5, and 27.8 kPa-1 in the pressure ranges of 0-0.5, 0.5-3.5, and 3.5-10 kPa, respectively. Furthermore, the sensor exhibits rapid response times (loading: 22 ms, unloading: 18 ms) and exceptional reliability, enduring over 3000 pressure loading and unloading cycles. Moreover, the pressure sensor can be easily integrated into a sensor array for spatial pressure distribution detection. The laser pyrolysis direct writing technology introduced in this study presents a highly efficient and promising approach to designing and fabricating high-performance flexible pressure sensors utilizing micro-structured polymer substrates.

A residual heat compensation based scan strategy for powder bed fusion additive manufacturing.

Typical scan strategies for laser powder bed fusion (LPBF) additive manufacturing systems apply a constant laser power and scan speed. Localized preheating from adjacent scan paths (residual heat) result in inconsistent melt-pool morphology. A new control approach is proposed which compensates the residual heat through laser power adjustment. A model called residual heat factor (RHF) is developed to 'quantify' the residual heat effect, and laser power is controlled proportional to this RHF. Experiments are conducted on a custom-controlled LPBF testbed on nickel-alloy (IN625) bare plate, and the effects of this unique scan strategy are investigated by in-situ melt-pool monitoring.

Light source is critical to induce glioblastoma cell death by photodynamic therapy using chloro-aluminiumphtalocyanine albumin-based nanoparticles.

Selection of an efficient light source is fundamental in the development of photodynamic therapy (PDT) protocols. However, few studies provide a comparison of different light sources with regard to phototoxic effects. Here, we compared the cell death induced by photoactivation of chloro-aluminiumphtalocyanine (AlClPc)-loaded human serum albumin nanoparticles under irradiation with different light sources: continuous laser (CL), pulsed laser (PL), and light-emitting diode (LED). Cells were exposed to three different AlClPc concentrations (1, 3, and 5µM) and three different light doses (200, 500, and 700mJ/cm2) for each light source. Cell death and differentiation of apoptosis and necrosis pathway were measured by flow cytometry. CL was the best light source for improving the photodynamic action of AlClPc-loaded albumin nanoparticles in glioblastoma cells and avoiding undesirable side effects, especially at low photosensitizer doses (200mJ/cm2). In addition, apoptosis was the main cell death pathway in all evaluated cases (70% for CL, and greater than 50% for PL and LED). In conclusion, the search for optimal light sources and light/photosensitizer doses is a crucial step in improving PDT outcomes and enhancing the clinical translation of PDT.

The efficacy and safety of 2-µm continuous laser in the treatment of high-risk patients with benign prostatic hyperplasia.

Two-micrometer laser resection of prostate-tangerine technique dissects whole prostatic lobes off the surgical capsular, similar to peeling a tangerine. The present study aimed to evaluate the safety and efficacy of 2-µm continuous laser vaporization in the treatment of high-risk patients with benign prostatic hyperplasia (BPH) during the 24-month follow-up. The study included 248 patients with moderate to severe lower urinary tract symptoms who underwent 2-µm continuous laser vaporization of the prostate. All patients were accompanied with different degree comorbidities and 94 patients were taking oral anticoagulants. BPH was successfully treated with 2-µm continuous laser vaporization in all patients. Mean pre-operative prostate volume was 76 ± 25.3 ml and mean operative time was 49.8 ± 16.5 min. There were no major complications intra-operatively or postoperatively, and no blood transfusions were needed. About 20 patients (8.1%) needed bladder irrigation postoperatively. Average catheterization time was 2.0 ± 1.8 days (range 1-5 days). Four patients required reoperation due to enlarged prostates from residual adenoma. At 3-, 6-, 12-, and 24-month follow-ups, maximum urinary flow rates (Qmax) increased from 6.9 ± 1.7 to 19.1 ± 4.2, 19.5 ± 4.6, 19.4 ± 4.6, and 19.5 ± 4.1 ml/s, respectively. Mean International Prostate Symptom Scores (IPSS) decreased from 27.6 ± 5.1 (pre-operation) to 9.2 ± 2.6, 7.12 ± 1.42, 6.18 ± 1.32, and 6.25 ± 1.30 at 3-, 6-, 12-, and 24-month post-operation, respectively. Two-micrometer continuous laser vaporization is a safe and effective surgical endoscopic technique associated with low complication rate in BPH patients at high risk and those on anticoagulation therapy who have severe LUTS caused by BPH.

Thulium laser treatment for bladder cancer.

Recent innovations in thulium laser techniques have allowed application in the treatment of bladder cancer. Laser en bloc resection of bladder cancer is a transurethral procedure that may offer an alternative to the conventional transurethral resection procedure. We conducted a review of basic thulium laser physics and laser en bloc resection procedures and summarized the current clinical literature with a focus on complications and outcomes. Literature evidence suggests that thulium laser techniques including smooth incision, tissue vaporization, and en bloc resection represent feasible, safe, and effective procedures in the treatment of bladder cancer. Moreover, these techniques allow improved specimen orientation and accurate determination of invasion depth, facilitating correct diagnosis, restaging, and re-evaluation of the need for a second resection. Nonetheless, large-scale multicentre studies with longer follow-up are warranted for a robust assessment. The present review is meant as a quick reference for urologists.