- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Gas distribution mapping for indoor environments based on laser absorption spectroscopy: Development of an improved tomographic algorithm
摘要： Gas distribution mapping (GDM) is an important technology for the study of indoor environment, which can be used to evaluate the efficiency of environmental control system and identify pollutant sources. Most recent studies have implemented GDM through contact sensors or a sensor network, which is difficult to calibrate all the sensors and cover the whole space. In this study, we introduced the non-contact tunable diode laser absorption spectroscopy (TDLAS) technology for GDM in the indoor environment. An improved tomographic algorithm, namely Least Square with Tikhonov Regularization (LSTR), was proposed and compared with two available tomographic algorithms using four validated computational fluid dynamics (CFD) simulations. We also analyzed the effects of the laser emitter placements and optical path densities on the concentration field reconstruction quantitatively. The results showed that the LSTR method could reduce the average relative root mean square error (RRMSE) of tomography by 52%, and the laser emitter at the long edge middle (LEM) can achieve better tomographic performance. The degree of the concentration dispersion from the source would mainly impact the tomographic results: when the sector dispersion (SD) value of concentration distribution was about 2.3 times larger, the average RRMSE value would be decreased by about 40%. The intersection matrix with a higher path density achieved a more accurately reconstructed map due to its lower condition number. In addition, the optical path density was suggested to twice the number of grid cells considering the trade-off between scanning time and accuracy.
关键词： Non-contact sensing,Tunable diode laser absorption spectroscopy (TDLAS),Concentration measurement,Indoor air,Air pollution
更新于2025-09-23 15:19:57
-
685PA MULTICENTER PHASE II STUDY OF SALVAGE PHOTODYNAMIC THERAPY USING TALAPORFIN SODIUM AND A DIODE LASER FOR LOCAL FAILURE OF ESOPHAGEAL CANCER AFTER CHEMORADIOTHERAPY
摘要： We previously reported that photodynamic therapy (PDT) has a potential to cure local failure after chemoradiotherapy (CRT) for esophageal cancer (EC). However, first-generation PDT using porfimer sodium and an excimer dye laser has several problems: a high occurrence of skin phototoxicity, the requirement of a long light shielding period (6 weeks), and the need for an expensive and large laser generator. Talaporfin sodium (Laserphyrin?) is a second-generation photosensitizer that requires a shorter light shielding period (2 weeks) and induces less phototoxicity. We previously identified the optimum diode laser fluence (100 J/cm2) for PDT using talaporfin sodium in the phase I/IIA study. Therefore, in the present study, we conducted a multicenter phase IIB study to evaluate the efficacy and safety of PDT using talaporfin sodium as a salvage treatment for local failure after CRT or radiotherapy (RT) for EC. (UMIN000009184).
关键词： chemoradiotherapy,non-colorectal,esophageal cancer,photodynamic therapy,talaporfin sodium,diode laser,gastrointestinal tumours
更新于2025-09-23 15:19:57
-
Evaluation of adjunctive efficacy of diode laser in the treatment of peri-implant mucositis: a randomized clinical trial
摘要： Peri-implant disease may affect survival of dental implants. The aim of the study is to analyze the effectiveness of diode laser as a supportive modality to the non-surgical conventional treatment of peri-implant mucositis (PiM) and initial peri-implantitis (PI). Twenty-three patients with single implants suffering from PiM or initial PI were selected and randomly divided into two groups; control group (CG) received non-surgical conventional treatment, and test group (TG) received non-surgical conventional treatment and diode laser application with wavelength of 980 nm. Probing pocket depth (PPD) and bleeding on probing (BOP) were recorded at baseline (T0) and at 3 months follow-up (T1). The average of PPD value for TG was 4.04 ± 0.54 mm at T0 and it was 2.98 ± 0.70 mm at T1. In the CG, PPD average was 3.8 ± 1.24 mm at T0 and was 3.54 ± 0.35 mm at T1. In TG, the BOP was positive in 44 sites at T0 and in 6 sites at T1. In CG, the BOP was positively observed in 52 sites at T0 and in 28 sites at T1. The 980-nm diode laser may be considered an adjunct to the conventional non-surgical treatments of PiM and initial PI.
关键词： Mucositis,Debridement,Dental implants,Peri-implant,Diode laser
更新于2025-09-23 15:19:57
-
Effect of low power laser irradiation on bio-physical properties of wheat seeds
摘要： The production of quality food is indispensable and essential to overcome its global shortage. In order to exercise the facile route to acquire massive production, a laser irradiation treatment method was established. We have investigated the effects of diode laser irradiation on wheat seeds germination, its early growth and biochemical parameters. The variation in germination parameters, caused by laser treatment were monitored carefully. A comparison study was accomplished to examine the laser irradiation effects on treated and control seeds. The red laser indicated an enhancement of 25% in germination percentage, 4.68 cm in shoot length, and 0.64 cm in root length while green laser showed 6.25% less germination percentage than the untreated seeds. Further green laser showed 9.67 cm increase in shoot length, 5.39 cm in root length as compared to untreated seeds. It was found that the seeds which were irradiated with green laser showed an amount of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), of 11.9, 10, and 1.53 per mg of protein, respectively as compared to control seeds. Thus, these investigations are promising and suitable for upcoming research on a large scale.
关键词： Wheat,Biochemical parameters,Protein,Germination parameter,Diode laser
更新于2025-09-23 15:19:57
-
Membrane modification with semiconductor diode laser to reduce membrane biofouling for external MBR system and modelling study
摘要： Membrane biofouling is one of the major problem for membrane-based wastewater treatment. In this study, we used laser technology to modify ultrafiltration polyethersulfone (UP150) membrane in order to decrease membrane biofouling. Semiconductor laser diodes with different wavelengths of 405, 520, and 658 nm and different power density of 1.5, 2.0, 2.5 mW were used to improve membrane structure against biofouling. The pure water permeability (Lp), contact angle, porosity, and the average pore size were determined for pristine and modified membranes. Lp value of the pristine UP150 membrane (1102.0 L/(m2.h.bar)) was higher than modified membrane (19.2 L/(m2.h.bar)). The contact angle values were presented that hydrophilicity was decreased from 75.1° to 61.2° for 2 h at 2.5 mW laser irradiation. Membrane porosity increased from 63.2 to 67.7%; however, the average pore size decreased from 88 to 23 nm after laser modification. The impact of laser wavelength and irradiation time on the rejection of protein (bovine serum albumin, BSA) and the fractions of soluble microbial products (as protein and carbohydrate) was systematically investigated. A maximum rejection of 32.2% and 41.9% was obtained for carbohydrate and protein when activated sludge was filtrated through modified membrane. Moreover, 100% BSA rejection was obtained by the modified membrane when BSA solution was filtrated. The modified membranes were extensively characterized by AFM, FTIR, SEM, and mechanical strength test analyses to observe morphological changes of the membrane before and after modification. The results showed that laser irradiation was changed the membrane morphology. Our results presented that laser-modified membranes with red wavelength changed the pore size, porosity, hydrophilicity of the pristine membrane. Also, membrane surface melting was revealed with a study called “Thermal Analysis on Membrane Surface Modelled 3D” using Solidworks CAD/CAM software. The results obtained from Solidworks thermal analysis was presented with 98.7% ratio of successful approach.
关键词： membrane biofouling,Membrane modification,semiconductor diode laser,activated sludge filtration
更新于2025-09-23 15:19:57
-
Management of oral vascular anomalies with diode laser: report of 2 clinical cases
摘要： Purpose This article reports the usefulness of a 980-nm diode laser (Simpler, Dr Smile) for the treatment of oral cavity vascular abnormalities. Introduction Vascular abnormalities are common vascular lesions characterized by elevated, usually, dome-shaped papules. These range in color from dark blue to dark purple and are seen more frequently in elderly patients. They often occur as single lesions on the lips, cheeks, and tongue. Although these lesions are usually asymptomatic, they can bleed if injured. Case report The first case is about a 42-year-old woman referred for evaluation of a facial and oral bluish lesion. Clinically, we diagnosed this extensive lesion as an acquired hemangioma. Under local anesthesia (Mepivacaine), we performed a photocoagulation of the lesion using a 980-nm diode laser (Dr Smile) in noncontact mode (2 mm of focal distance) with a 300-nm fiber, continues mode, 1.5 W power, during 1 min. The session was repeated 15 days later. After 6 weeks, wound healing was completed uneventfully. The second case is about a woman, aged 54, sent by a colleague for a purplish lesion on the inner side of the left cheek. Clinically, we diagnosed venous malformation. With the same diode (980 nm), we worked 2–3 mm away from the surface of the lesion, with a power of 4 W in continuous mode, under local anesthesia (Mepivacaine). The patient received only one session. The following controls at 10, 20, and 30 days showed the persistence of an ulceration which healed after 40 days. Conclusion The patients had no complications during the laser sessions, and their postoperative period was uneventful. We, therefore, concluded that the diode is an excellent therapeutic alternative in the treatment of oral cavity venous malformations.
关键词： Venous malformation,Photocoagulation,Vascular abnormality,Hemangioma,Diode laser
更新于2025-09-23 15:19:57
-
Pulverized coal combustion application of laser-based temperature sensing system using computed tomography a?? Tunable diode laser absorption spectroscopy (CT-TDLAS)
摘要： The investigation of combustion phenomena in pulverized coal flames is significant for combustion optimization related to energy conservation and emission reduction. Real-time two dimensional (2D) temperature and concentration distributions play an important role for combustion analysis. The non-contact and fast response 2D temperature and concentration distribution measurement method was developed in this study. The method is based on a combination of computed tomography (CT) and tunable diode laser absorption spectroscopy (TDLAS). The accuracy evaluation of developed 32-path CT-TDLAS demonstrated its feasibility of 2D temperature measurement. 32-path CT-TDLAS was applied to CH4 and 5 kg/h coal combustion fields for 2D temperature measurement. The time-series 2D temperature distribution in coal combustion furnace was measured using 32-path CT-TDLAS measurement cell with kHz time resolution. The transient temperature field of combustion flame directly reflects the combustion mode and combustion stability. The measurement results demonstrate its applicability of CT-TDLAS to various types of combustor, especially the combustion fields with coal and ash particles. CT-TDLAS method with kHz response time enables the real-time 2D temperature measurement to be applicable for combustion analysis.
关键词： 2D temperature measurement,Computed tomography (CT),Tunable diode laser absorption spectroscopy (TDLAS),Time-series distribution,Coal combustion
更新于2025-09-23 15:19:57
-
A Cross-sectional, Multi-center Study on Treatment of Facial Acne Scars With Low-Energy Double-Pass 1450-nm Diode Laser
摘要： Objective: Acne scars is the ultimate outcome of acne vulgaris, a prevalent skin disorder affecting the pilo-sebaceous unit. Laser resurfacing has been demonstrated to be an efficient therapy option for acne scars. Hence, we adopted this concept and conducted a study to evaluate the safety and efficacy of low-energy double-pass 1450-nm diode laser on acne scars. Methods: This study was conducted on forty-eight patients with acne scars, treated at 4-week interval with low-energy double-pass 1450-nm diode laser. Patients were evaluated clinically and with photographs, at day 0, 1st month and 3rd month post the final treatment and during follow-up visit. Results: Five treatment sessions were completed by all patients. Approximately 79.2% of patients showed around 30% improvement. At the end of 3rd month follow-up, 92.9% of the patients demonstrated >30% improvement. Vesicle formation was observed in two cases, with no post-inflammatory hyperpigmentation (PIH) and transient hyperpigmentation was observed in one case, which vanished within 2 months. Conclusion: Our study showed that 1450-nm diode laser treatment was efficient and well endured in facial acne scars when used with double-pass at low-energy.
关键词： Improvement,1450-nm diode laser,Facial acne scars,Low-energy double-pass
更新于2025-09-23 15:19:57
-
Spectral Line Shape Analysis Using Hartmann-Tran Profile for Tunable Diode Laser Absorption Spectroscopy of Water Vapor at 1.39a????m
摘要： In this study, spectral line shape analysis was conducted for water vapor absorption at 1.39 μm with a Hartmann-Tran pro?le (HTP), which is capable of being ef?ciently and accurately reduced to (speed dependent) Voigt and (speed dependent) Rautian pro?les. The near-IR absorption lines of water vapor were measured using tunable diode laser absorption spectroscopy (TDLAS). The spectrum ?tting code was home-written based on the Trust region re?ective algorithm and the HTP. Voigt pro?le (VP), Rautian pro?le (RP), speed-dependent VP (SDVP), and speed-dependent Rautian pro?le (SDRP), which were reduced from the HTP, were used as model functions to test the validity of the near-IR absorption lines of water vapor in terms of line shape pro?le. With the SDVP, the standard deviation of the ?tting residuals was at a 10?3 level relative to the most intense peak height in a range of 1.39 μm at 2.5 Torr and room temperature, while the global standard deviation was less than 0.5 × 10?3, thus showing the best result among them. This suggests the need to consider the speed-dependent collision width in the self-broadening of water vapor.
关键词： Tunable diode laser absorption spectroscopy,Hartmann-Tran pro?le,Spectral lineshape analysis,Water vapor
更新于2025-09-23 15:19:57
-
Unusual exophytic gingival lesion in a newborn treated with diode laser
摘要： Gingival lesions rarely occur in newborns. However, when present, they commonly worry the parents and impair the infant’s feeding, thus affecting growth. Such lesions are usually nonneoplastic in nature, although malignancies may develop; therefore, specimens must be submitted for histopathologic examination. A 2-month-old girl presented with a 10-mm nodule on the anterior lower alveolar ridge in association with natal tooth extraction and neonatal tooth eruption. The lesion was excised with high-power laser under local anesthesia, and a histopathologic diagnosis of a peripheral ossifying ?broma was made. In addition to peripheral ossifying ?bromas being rare in newborns, the use of high-power lasers for surgical procedures in newborns have been proven to be safe, comfortable, and ef?cient.
关键词： natal tooth,diode laser,neonatal tooth,newborn,Peripheral ossifying ?broma
更新于2025-09-23 15:19:57