Search

To work in space, it is necessary to create high-tech production facilities in orbit. It seems that they should include a universal, compact, powerful laser device to perform various tasks. The paper considers only one, relatively new, direction of laser use, designed to improve the fire safety of a spacecraft. An environmentally safe method of "dry" laser etching for the rapid detection of the structure of metals and semiconductors is proposed. • Nanosecond pulses of Nd:YAG laser were used for Ge and Cu surface modification. • Dry laser etching is proposed for quality control of space-grown Ge single crystals. • Laser etching is proposed for fatigue control of metal products of orbital stations. [ABSTRACT FROM AUTHOR]

Introduction: Laser technology has fundamentally transformed the landscape of dermatology, offering nuanced solutions for skin rejuvenation and resurfacing. This paper aims to explore the spectrum of laser technologies, from ablative to non‐ablative and fractional lasers, their mechanisms, benefits, and tailored applications for diverse skin conditions. As we delve into the intricacies of each technology, we also consider the scientific advancements that have made these treatments safer and more effective, promising a new horizon in skin rejuvenation. Objective: This comprehensive analysis seeks to evaluate recent advancements in laser technology for skin rejuvenation, focusing on efficacy, safety, and patient satisfaction. Methods: The selection criteria for studies in this publication focused on recent, peer‐reviewed articles from the last 20 years, emphasizing advancements in laser technologies for skin rejuvenation. Our comprehensive review involved searches in PubMed, Cochrane, Scopus and Google Scholar using keywords like "skin rejuvenation," "laser technology," "efficacy," "safety," and "dermatology." This approach focused on inclusion of recent research and perspectives on the efficacy and safety of laser treatments in the field of dermatology. Results: Our literature review reveals advancements in laser skin resurfacing technologies, notably fractional lasers for minimal downtime rejuvenation, ablative lasers for precise tissue vaporization, and non‐ablative lasers for coagulation effect promoting collagen with reduced recovery. Hybrid and picosecond lasers are highlighted for their versatility and effectiveness in addressing a wide array of skin concerns. The findings also emphasize the development of safer treatment protocols for ethnic skin, significantly reducing risks like hyperpigmentation and scarring, thus broadening the scope of effective dermatological solutions. Conclusion: This extensive review of advancements in laser technologies for skin rejuvenation underscores a remarkable evolution in dermatological treatments, offering an expansive overview of the efficacy, safety, and patient satisfaction associated with these interventions. Furthermore, the exploration of combination treatments and laser‐assisted drug delivery represents a frontier in dermatological practice, offering synergistic effects that could amplify the therapeutic benefits of laser treatments. [ABSTRACT FROM AUTHOR]

The results of experiments with a model of an optically pumped rare-gas laser are presented. Laser generation was produced simultaneously at three wavelengths (912.3, 893.1, and 877.7 nm) using a gas mixture consisting of 98% He (buffer gas), 1.5% Ar, and 0.5% Kr. Dependence of generation power and of the ratio of the intensities of individual lines in total generation on consumption of the gas mixture, on cuvette pressure, and on the discharge pulse repetition rate has been studied experimentally. The maximum laser power (the sum of all the wavelengths) was ~8 mW. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: Striae distensae (SD), or stretch marks, result from rapid stretching of the skin due to various factors. Conventional treatments often yield unsatisfactory results, leading to the exploration of alternative methods. Laser‐induced microjet technology offers a promising approach for drug delivery to target areas. This study investigates the efficacy of using a microjet injector with poly‐d,l‐lactic acid for treating SD. Methods: Four female participants with SD were treated with poly‐d,l‐lactic acid solution using a microjet injector over five sessions. Patients were assessed based on severity scales before and after treatment. Topical anesthetics were applied to minimize discomfort. Injection techniques were optimized to reduce side effects such as bleeding and pain. Results: All patients showed significant improvement in SD appearance after 5–7 treatments. Assessment scales indicated positive outcomes both immediately after treatment and at the 32‐week follow‐up. Minimal side effects, primarily petechiae, were observed. Discussion: Laser‐induced microjet technology offers several advantages, including rapid drug delivery and mechanotransduction effects, promoting skin regeneration. Poly‐d,l‐lactic acid injections demonstrated effectiveness in treating SD, particularly when delivered via microjet injectors. Patients expressed high satisfaction due to the procedure's minimal invasiveness and quick recovery. Conclusion: Utilizing a needleless microjet injector with poly‐d,l‐lactic acid shows promise as a treatment for SD, typically requiring 5–7 sessions for optimal results. Mild petechiae may occur as a common side effect. This approach offers an effective and minimally invasive alternative for addressing this common cosmetic concern. [ABSTRACT FROM AUTHOR]

Root canal therapy (RCT) is usually performed in Romania by general dentists (GDPs) because they are more readily available and more reasonably priced than endodontists. Concerns have been raised about the quality of RCTs performed by GDPs, possibly due to insufficient equipment or knowledge; therefore, this study aims to investigate current endodontic practices in Romania. Materials and Methods: A cross-sectional study was conducted via a questionnaire distributed to 400 randomly selected Romanian dentists, with 285 fully validated completed responses (71.25% response rate). Respondents were grouped by speciality, and statistical analysis, including cross-tabulation and the χ2 (chi-square) test, was used, with a significance level set at p ≤ 0.05 for all tests. Results: Significant differences were found in the use of magnification, rubber dam, sodium hypochlorite concentration, and bioceramics (p < 0.001). No significant differences were observed in preferences for measuring working length (p = 0.166) or rotary instrument motion (p = 0.289). Approximately 6% of the respondents used laser technology with no significant difference across specialities (p = 0.571). Additionally, 77.9% preferred using sodium hypochlorite, with no significant difference between groups (p = 0.006) regarding concentration. Conclusions: Most participants, including GDPs, use modern equipment and techniques during RCT, indicating their awareness and competence in current endodontic practices. [ABSTRACT FROM AUTHOR]

The transient temperature field during laser-directed energy deposition has a crucial impact on the quality of manufactured parts. In this study, in order to solve the problems that the transient temperature field is difficult to measure directly and the traditional numerical simulation data are not real time and the model is inaccurate, a transient temperature field twin method based on the optimization of measured parameters is proposed. First, based on heat transfer, a twin model of temperature-dependent thermophysical parameter fluctuations is built, and the model defines the time-dependent power parameters. In order to perform numerical simulations for the acquisition of the temperature field distribution and to verify the accuracy of the model through the comparison of synchronized lateral validation experiments, an integrated measurement-validation experimental system is constructed. A twin model validation method is proposed, in which the frontal measurement experiments are synchronized with the lateral validation experiments. The real-time radius of the molten pool and temperature parameters are extracted from the frontal measurement experiments and inputted into the twin model. In order to confirm the great realism of the built twin model, the simulation of the twin temperature field under various laser strengths is examined in the last step. The experimental findings demonstrate that the temperature field twin physical model developed in this work is capable of faithfully simulating temperature field variations brought about by real-time laser additive process parameter changes. This approach reduces the number and expense of actual tests, helps to adjust process parameters to ensure an improvement in product quality and performance, and makes up for the lack of real-time problems in traditional numerical simulation. It also improves the accuracy and real-time simulation model. Finally, it has the ability to instantly provide input and track the production process in real time. It helps to advance the application of digital-twin technology in the field of additive manufacturing. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Intelligent Agriculture Mechanization is the property of Nanjing Institute of Agricultural Mechanization and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study investigates the use of Transverse Electric (TE) and Transverse Magnetic (TM) modes in sophisticated optical systems, with a specific emphasis on their influence on fiber optic communications, laser technology, optical sensors, and photonics. Through the use of intricate simulations, we demonstrate how these modes increase transmission efficiency, improve the quality of laser beams, and augment sensor precision. The research emphasizes the crucial significance of TE and TM modes in enhancing the efficiency of optical devices and offers valuable insights for future advancements in optical systems. [ABSTRACT FROM AUTHOR]

Copyright of Arab International Journal of Digital Art & Designs is the property of Arab Institution of Knowledge Management and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The global decarbonization will have to be driven by the e-mobility sector to achieve the climate goals. End-of-life battery packs therefore need to be recycled efficiently and sustainably so that a cost-competitive circular economy can be adopted. In current process approaches, once the battery is discharged, disassembly is typically performed manually in a process that is not automated and dangerous to workers. To disassemble, first the battery cover must be removed, whereby current technological approaches focus on screw connections, which are difficult to loosen due to their condition after many years in the vehicle and cause poor automation capability. Another alternative is to mechanically mill the battery cover, which creates chips inside the battery pack that can cause short circuits. Waterjet cutting, which is also a process approach, faces the challenge of water getting into the battery pack, which can also lead to short circuits. Therefore, there is a need for new technological approaches which can dismantle an automotive battery pack productively with enhanced safety standards for workers and batteries. For this purpose, this paper performs a compact benchmark analysis of different separation technologies to identify initial potentials and challenges for laser-based disassembly of automotive battery packs. [ABSTRACT FROM AUTHOR]

Background: Pediatric dental procedures like pulpotomy and pulpectomy are commonly performed to treat pulp-related dental issues in primary teeth. The choice of instrumentation, such as traditional rotary instruments or laser technology, can impact the oral microbiota. This study aims to compare the changes in oral microbiota following pulpotomy/pulpectomy in pediatric patients treated with traditional rotary instruments versus laser technology. Materials and Methods: A total of 60 pediatric patients, aged 4–10 years, requiring pulpotomy or pulpectomy were randomly assigned to two groups: group A (traditional) and group B (laser). In group A, traditional rotary instruments were used for pulp removal, while in group B, a dental laser was utilized. Saliva and plaque samples were collected before the procedure (baseline), immediately after the procedure, and at the one-month follow-up. Microbial deoxyribonucleic acid (DNA) was extracted and analyzed using 16S ribosomal ribonucleic acid (rRNA) sequencing to assess changes in the oral microbiota. Results: At baseline, both groups exhibited similar microbial diversity and composition. However, immediate post-procedure results showed a significant decrease in microbial diversity in both groups, with group B (laser) demonstrating a more pronounced reduction. At the one-month follow-up, group A (traditional) showed a partial recovery of microbial diversity, while group B (laser) continued to exhibit lower microbial diversity compared to baseline. Notably, group B (laser) displayed a shift in microbial composition with a decrease in pathogenic species and an increase in beneficial bacteria compared to group A. Conclusion: This study highlights that both traditional rotary instruments and laser technology have a significant impact on the oral microbiota of pediatric patients following pulpotomy/pulpectomy. While both methods initially reduce microbial diversity, laser treatment appears to have a more sustained effect, favoring the growth of beneficial bacteria over time. Further research is needed to assess the long-term clinical implications of these microbiota changes for the oral health of pediatric patients.

Copper and its alloys have various applications in the metallurgical industry due to their good thermal conductance. Continuous casting mold, blast furnace tuyere cooler, and converter oxygen lance’s nozzle are the core components to ensure normal steel production. With increasingly severe service conditions and the goal of long component life, there is an urgent need to improve the surface properties of copper alloy components to curb premature component failure due to surface abrasion, corrosion, or oxidation. Therefore, the effective surface treatment of copper alloy parts is of great significance to the development of the steel industry, which combines the high thermal conductivity of copper alloys and the high strength, heat resistance, or corrosion resistance of the protective layer. There have been numerous attempts to apply surface technologies to metallurgical equipment and more reports on surface treatment technologies for copper and copper alloys. However, fewer reports have systematically sorted out the failure forms of key metallurgical components of copper alloys and the current state of research on surface treatment technology for copper alloys. Therefore, this paper first reviews the main surface failures of three key copper alloy components, namely the continuous casting crystallizer, the blast furnace air outlet bushing, the converter oxygen lance head, and the current technical methods to improve the overall performance of these components. Second, this paper reviews the current research and development status of several surface treatment technologies in the field of copper alloy surface modification, such as electroplating, thermal spraying and cold spraying, surface fusion coating, laser treatment, and alloy co-infiltration. Moreover, it highlights the emerging thermal spraying, cold spraying, surface fusion coating technology, and laser surface treatment technology; contrasts and analyzes the advantages and disadvantages of these surface treatment technologies; and provides an overview of the physical vapor deposition refractory high-entropy alloy film technology. The potential application of physical vapor deposition of refractory high-entropy alloy films in surface strengthening of copper alloys is prospected. Developing new coating materials, optimizing the physical vapor deposition technology coating process, and combining various surface treatment technologies (such as laser surface treatment and surface coating technology) are possible directions to improve surface properties and bond strength. They will enable a longer life of copper alloy components for metallurgical equipment.

• Laser and photochemistry were first used in restoring and transformation of PbS on painted cultural relics. • Targeted fast realization of restoring and transformation of PbS, and without damage to the base color. • Laser catalysis restoration has wide applicability to papers, the silks and other organic materials. Lead white darkening is a common disease in all kinds of painted cultural relics. In this study, a combination of laser and photodynamic technology was used to achieve controlled restoration of lead sulfide at the lead darkening site on the painted layer of cultural relics by laser catalysis with porphyrin to produce singlet oxygen. The chromatic change, micromorphology and chemical composition were systematically studied for a simulated sample with the lead darkening part of the painted layer. The results show that laser catalytic treatment can repair the color darkening that occurs by the PbS formation, while no obvious changes to the pore and microparticle structure of the painted layer and the base. In this study, the pollutant of lead sulfide was proved to be converted into lead sulfate by oxidation, and then was converted to lead white by precipitation, which was the original composition of the pigment. It is also found that the laser catalytic treatment method can effectively avoid basic layer damages of cultural relics, especially for the papers, the silks and other organic materials. This technology not only provides a new approach for the restoration and transformation of PbS on painted cultural relics, but also makes available new applications for the laser and photodynamic technology in the field of cultural relics protection. [ABSTRACT FROM AUTHOR]

Vortex beams are unique in that they have annular spatial profiles and carry orbital angular momentum. This has led to their use in applications including laser processing, microparticle manipulation and signal transmission. Off-axis vortex beams, which may be considered a subset of vortex beams, display a broader spectrum of physical characteristics in comparison with their conventional (integer-order) counterparts. In this work, we derive the equations which describe the intensity distribution of off-axis vortex beams and use these to theoretically model their spatial profile. These models are supported by experimental generation of both integer and off-axis vortex beams, and the presence of orbital angular momentum is investigated through the use of the cylindrical lens transformation method. [ABSTRACT FROM AUTHOR]

We review the literature concerning the effects of laser light on organisms (insects) and microorganisms (bacteria, viruses, fungi) present in agri-food systems. The evidence obtained shows that 1) Laser light is a sustainable technology that can be applied as a pesticide with the ability to annihilate and control insects. Higher annihilation rates are observed for more pigmented products, as determined by their thermal and optical properties. 2) The most frequently used laser beams to eliminate bacteria harmful to human health operate with a steady intensity in the visible domain (blue, green, and red light). 3) Laser beams are applied to control fungi (the most studied microorganism), viruses, as well as to increase plant resistance to them. Lasers with red beams, such as those emitted by He-Ne lasers, followed by diode lasers are most frequently reported in fungal control. Furthermore, antibacterial, and germicidal effects are increased by using photosensitizers. Finally, 4) laser light potentiates the metabolites and antimicrobial activity of some plants thereby improving their activity. Agri-food systems treated with laser beams have the potential to improve the quality of life of society. [ABSTRACT FROM AUTHOR]

In laser-based space technologies where laser beams are transmitted from a ground station, it is required for the ground station to avoid irradiating aircraft with high energy lasers. A simple, inexpensive acoustic positioning technique using four microphones is developed and its performance is evaluated. It is demonstrated to be sensitive to and effective in detecting aircraft flying at short ranges. Aircraft closer than 5 km can easily be detected and the maximum range is about 10 km. The time series of two-dimensional directional position estimates are harmonic with those of ADS-B (Automatic Dependent Surveillance-Broadcast), and the precision reaches 1 degree (standard deviation) in the best case. The processing time for data collection and computation is short enough to establish a realtime feedback mechanism to stop firing laser. With its advantages and disadvantages, effective combinations with existing methods are discussed to avoid injury to the eyes, in which the acoustic approach is found to be useful to enhance safety measures in particular of low-altitude aircraft with a large angular velocity. [ABSTRACT FROM AUTHOR]

Abstract:Key Words: Design - Ribbon- Art nouvea- Laser technology- Printing - Evening clothes.Decorative ribbons have developed remarkably over the ages, with the designer's new additions and what the era requires of innovations. Decorative ribbons add vitality and beauty to the garments to give them taste and beauty.The fashion designers were interested in quoting from different sources to elevate the designs of all kinds, and among these sources is Art Nouveau, which is characterized by individuality and creativity, which resulted in wonderful works that were created using new materials, and therefore it was used in the design of decorative strips.In an attempt to move away from the ordinary and integrate everything that is technological with everything that is ancient, whether it is art or culture, all this prompted the researcher to produce decorative tapes inspired by Art Nouveau using the combination of laser cutting technology and the effects of manual printing, as this is a kind of creative integration. , In order to enrich the aesthetic values of evening clothes for women.The research was conducted with the aim of reviving Art Nouveau art by proposing designs for modern and innovative decorative tapes characterized by uniqueness and elegance inspired by this ancient art, while producing decorative tapes of utilitarian and aesthetic value by combining laser cutting technology and manual printing techniques (direct drawing), and employing decorative tapes in A group of evening wear designs for women, implementing the nine best designs that were accepted by specialists, and identifying the degree of acceptance of the target group for the implemented research designs.The research followed the descriptive analytical method and the experimental method, due to its suitability to achieve the objectives of the research and verify its hypotheses.The research included two questionnaires and statistical analysis, one of them measuring several axes of the proposed designs, numbering (24) designs, which were presented to a group of specialists and implementing the best (9) proposed designs according to their opinions, and another measuring several axes of the implemented designs, which were presented to a group of consumers to express their opinions.The research found the possibility of designing decorative ribbons inspired by Art Nouveau using laser technology and printing, and using them in women's evening clothes.

Root canal therapy (RCT) is usually performed in Romania by general dentists (GDPs) because they are more readily available and more reasonably priced than endodontists. Concerns have been raised about the quality of RCTs performed by GDPs, possibly due to insufficient equipment or knowledge; therefore, this study aims to investigate current endodontic practices in Romania. Materials and Methods: A cross-sectional study was conducted via a questionnaire distributed to 400 randomly selected Romanian dentists, with 285 fully validated completed responses (71.25% response rate). Respondents were grouped by speciality, and statistical analysis, including cross-tabulation and the χ2 (chi-square) test, was used, with a significance level set at p ≤ 0.05 for all tests. Results: Significant differences were found in the use of magnification, rubber dam, sodium hypochlorite concentration, and bioceramics (p < 0.001). No significant differences were observed in preferences for measuring working length (p = 0.166) or rotary instrument motion (p = 0.289). Approximately 6% of the respondents used laser technology with no significant difference across specialities (p = 0.571). Additionally, 77.9% preferred using sodium hypochlorite, with no significant difference between groups (p = 0.006) regarding concentration. Conclusions: Most participants, including GDPs, use modern equipment and techniques during RCT, indicating their awareness and competence in current endodontic practices.

A nanosecond pulse laser is used to conduct laser cleaning experiments on the oxide after welding of 6061 aluminum alloy. Firstly, This paper analyzes the surface morphology and elemental composition of the solder joint before and after cleaning, and determines the composition of the oxide after welding. Secondly, based on the influence of different process parameters on cleaning quality obtained from previous experiments, orthogonal experiments are designed to delineate the range of each factor interval and analyze the weight of the influence of parameters on cleaning quality.By using the orthogonal experimental method, it is found that the order of parameters affecting the peak valley values of surface contour lines is： Laser power> pulse frequency>scanning speed>pulse width. The order of parameters that affect the weight percentage of o element is： Pulse width>scanning speed>laser power>pulse frequency. The optimal process parameter group is obtained through the comprehensive balance method： Scanning speed, laser power, pulse frequency, and pulse width are 2 950 mm/s，141 W，29 kHz, and 330 ns, respectively. The optimal parameters can ensure thorough oxide cleaning, no substrate damage, and high cleaning efficiency of aluminum alloy after welding. [ABSTRACT FROM AUTHOR]

Purpose of Review: In this review, the current literature available that evaluates the use of Moses pulse-modulated holmium technology for laser enucleation of the prostate will be addressed. Topics include safety and surgical case efficiency, length of post-operative foley catheter and hospital stay, surgical outcomes, and areas of future research. Recent Findings: Some early retrospective studies and select randomized control trials seek to determine if novel laser technologies can improve peri-operative outcome measures or reduce the morbidity of endoscopic enucleation of the prostate while maintaining or improving the safety profile of holmium laser enucleation of the prostate (HoLEP). Both objective and subjective outcomes of HoLEP are seen to be preserved in patients undergoing Moses laser enucleation of the prostate (MoLEP), with recent studies highlighting high rates of successful same-day catheter removal and same-day discharge in an increasingly wide range of patients. Summary: Initial studies focusing on Moses laser technology for prostate enucleation are promising. Further high-quality randomized controlled trials evaluating MoLEP are required to clarify the clinical impact of this laser technology on prostate enucleation outcomes as well as comparing to alternative novel benign prostate hyperplasia (BPH) treatments. [ABSTRACT FROM AUTHOR]

Vortex beams are unique in that they have annular spatial profiles and carry orbital angular momentum. This has led to their use in applications including laser processing, microparticle manipulation and signal transmission. Off-axis vortex beams, which may be considered a subset of vortex beams, display a broader spectrum of physical characteristics in comparison with their conventional (integer-order) counterparts. In this work, we derive the equations which describe the intensity distribution of off-axis vortex beams and use these to theoretically model their spatial profile. These models are supported by experimental generation of both integer and off-axis vortex beams, and the presence of orbital angular momentum is investigated through the use of the cylindrical lens transformation method.

Introduction: Recent decades have seen a move to minimally invasive techniques to manage urolithiasis. Trainees are expected to develop competency in common endourology procedures. Knowledge of ureter mechanics and the theory behind new technologies is important to ensure safe and efficient techniques. We aim to evaluate the exposure to endourology, self-reported competency in common techniques and knowledge of basic ureter biomechanics and technology in training urologists. Methods: An online survey was circulated to all training urologists in the Republic of Ireland. Questions focused on self-reported competency, clinical knowledge, ureter mechanical properties and laser technology. Results: Thirty responses were received with a range of 1-8 years of urology experience (mean = 4 years). The respondents reported high levels of exposure to endourology with the majority reporting competency in flexible ureterorenoscopy (FURS) (n = 18, 60%) and semi-rigid ureteroscopy (URS) (n = 21, 70%). The respondents demonstrated good clinical knowledge but variable knowledge of laser settings, laser thermodynamics and ureter mechanics. Half of the respondents (n = 15, 50%) correctly described fragmentation laser settings, with 10 trainees (n = 33%) accurately identifying both factors that increase ureteral access sheath (UAS) insertion force. Most of the respondents (n = 20, 67%) described the proximal ureter as the site with the greatest compliance, while the site of the greatest force during ureteroscope insertion was correctly identified by 17% (n = 5). Conclusion: To our knowledge, this represents the first study evaluating urologist understanding of laser technology and the mechanical properties of the human ureter. Despite trainees reporting high levels of experience in endourology, there is a variable understanding of the principles of laser technology and ureter mechanics. Further research and education are needed with a focus on laser safety, suitable laser settings and the safe limit of insertion forces. [ABSTRACT FROM AUTHOR]

Studies have been made on the development of military science and it has been established that for the modernization of the army and the defense industry it is necessary to develop and search for new innovative technological solutions in the field of laser technology and photonics. According to the trends in the use of laser technologies for military applications, the need to acquire knowledge in the field of “Laser Safety” has also been proven. The report substantiates the need to train cadets and students in a military university. A curriculum on “Laser Safety” is proposed and what knowledge and skills future officers should acquire are indicated. [ABSTRACT FROM AUTHOR]

According to the repair demand of aircraft 30CrMnSiA high-strength steel pull rod, the laser cladding process research and pull rod repair were carried out using gas atomized 30CrMnSiA powder as cladding material. The effects of different process parameters on forming quality were compared. The microstructure, mechanical properties and wear resistance of the cladding area under the optimal laser process were studied, and the damaged part of the pull rod was repaired by this process and dimensional measurement was carried out. The results show that using the optimal laser cladding process, the cladding layer with good metallurgical bonding with the base metal and dense microstructure can be obtained. The cladding layer is composed of columnar or honeycomb shaped ferrite and surrounding martensite. The microhardness of the cladding layer is about 475HV, about 36% higher than that of the base metal, and the average tensile strength of the joint is about 9% higher than that of the base metal. Compared with forged 30CrMnSiA steel, the depth of wear track of the cladding layer is reduced by 27.7%, and the width of wear track is also reduced by 35.2%, which means better wear resistance. By using this process, a repaired pull rod with good cladding quality, satisfactory dimensional accuracy and basically no thermal deformation is obtained, so the qualified products are delivered.

Abstract Background Glaucoma is a group of eye diseases that can damage the optic nerve and cause vision loss. A novel technology micropulse laser trabeculoplasty (MLT) can use duty-circle subvisible laser pulses to treat glaucoma. The aim of this study is to evaluate the efficacy of 360° MLT to alleviate intraocular pressure (IOP) in patients with glaucoma. Methods This was a single-center prospective study on patients treated with 360° MLT using a Diode True-Yellow 577-nm Laser with MicroPulse technology. All the patients were recruited from the Department of Ophthalmology. Follow-up visits were carried out at 1 day, 1 week, 1 month, 3 months, 6 months, 18 months, and 36 months after the procedure. Best-corrected visual acuity (BCVA), Intraocular pressure (IOP), and vertical cup-to-disc ratio (C/D ratio) were measured during the follow-up. Repeated-measures analysis of variance (ANOVA) and Kaplan–Meier analysis were performed to evaluate the outcomes. Results A total of 39 eyes from 25 patients were included in this study (10 men/15 women). The average age of patients was 41.47 ± 14.39 years old, and the baseline IOP was 21.13 ± 7.75 mmHg. MLT significantly reduced the IOP at 1 day (range 15.61–19.01, P = 0.0218), 3 months (range 16.47–19.22, P = 0.0390), and 6 months (range 15.38–18.56, P = 0.0332) compared with the baseline. However, by the end of the study, only 21.88% of patients demonstrated a ≥ 20% IOP reduction, while seven eyes needed further laser or surgical treatment. The IOP of glaucoma patients was significantly lower than the ocular hypertension patients at 1 month (P = 0.0124), 3 months (P = 0.0004), 18 months (P = 0.0061) and 36 months (P = 0.0119). Conclusions Micropulse laser trabeculoplasty reduce IOP in patients with glaucoma or ocular hypertension for a short period, but its lowering efficiency is limited up to 6 months of the follow-up period.

This paper is devoted to construction of a mathematical model for determining the distribution function of blood cells by size. After considering the problem of light scattering on a spheroidizied particle with a multilayer structure and arbitrary oriented in space, the reflection coefficient of a plane wave from the biostructure model with a smoothly irregular structure has been found. This approach made it possible to construct a model of the said structure with several layers. Based upon the reflection of a Gaussian beam from this structure the distribution function of blood cells by size was obtained. Some methods such as the T-matrices apparatus, the Huygens – Fresnel transform, the Tikhonov's regularization were involved. The mathematical model proposed for the first time allowed theoretical calculation of the size distribution functions of spheroidizied particles simulating blood cells for the case in vivo.

Repetition rate-tunable single-longitudinal-mode (SLM) lasers are in wide demand for light detection and ranging. This study proposes an SLM acoustic-optical Q-switched Nd:YVO4 laser based on a short-cavity scheme. The laser system consists of a laser diode (LD) pump source, coupling optics, input mirror coupler (IC), Nd:YVO4 crystal, acousto-optic Q-switching system (AOQS), and output mirror coupler (OC). The mode selection is theoretically analyzed and confirmed from the experimental setup. The laser output obtains a 10 ns pulse duration, SLM with a linewidth of 279.43 MHz, and good stability that is maintained in the range of 1 to 4 kHz. The results demonstrate that the proposed method is a simple and robust source-laser scheme for high-power systems.

Conventional farming practices can provide higher agricultural yields through the extensive use of fertilizers, pesticides, and other inputs. These practices have been associated with severe environmental effects, such as eutrophication, acidification, etc. Laser technology, among many other techniques, could be a viable option for environmental reduction if incorporated into agricultural production systems. However, the environmental performance of using lasers in agriculture practices needs to be investigated in order to provide sustainable management of the agriculture sector. Therefore, in this study, the life cycle assessment (LCA) of laser-induced maize production in bio-stimulated seeds was compared to conventional farming practices using the software SimaPro ver. 9.0. The study emphasized human toxicity, freshwater ecotoxicity, and marine ecotoxicity due to their significant contributions. The results demonstrated that laser technology was an environmentally friendly system for treating maize seeds before sowing. The study further identified the mineral fertilization process as the most critical threat to the environment. Based on normalization, maize production process-related toxicity accounts for the highest environmental impacts of 8.2 and 7.3 kg 1,4-DCB/ton of grain produced by conventional practices and laser maize production, respectively, on the general environmental profile. At the endpoint level, the irradiated maize seeds performed better than their non-irradiated counterpart impacting human health at 5.46 × 10−3 DALY, ecosystems at 1.86 × 10−5 species⋅year, and resources at 60.74 USD 2013. Soil management was also identified as the conventional maize production process with the most significant environmental impacts. The greatest observed impacts were on marine ecotoxicity (19.23 kg 1,4-DCB) and freshwater ecotoxicity (12.94 kg 1,4-DCB) per ton of grain produced. The evaluation of potential human toxicity concluded that zinc contributed more than 90% in ReCiPe 2016 Midpoint (H) and benzene contributed approximately 22% in CML 2000. The study concluded that improved environmental performance was obtained for laser-induced maize production compared to conventional farming practices. The LCA can provide information to policymakers and government agencies about shifting to more sustainable agricultural practices in arid regions, such as Iraq, prone to drought linked to water availability and soil salinity. [ABSTRACT FROM AUTHOR]

The effect of nanosecond-pulsed laser milling on the surficial microstructure of Al2O3 ceramics is studied in this work. The macrostructure, microstructure, surface roughness, and milling depth of the ceramics are analyzed via scanning electron microscopy and confocal laser scanning microscopy. The results reveal that the surface roughness and the milling depth of Al2O3 ceramics increase with increasing laser power, laser repetition rate, and scanning times. After nanosecond-pulsed laser milling, cavities as well as molten and granular solidified structures are observed on the Al2O3 ceramic surface, which indicate that the main mechanism of nanolaser milling is the melting and gasification caused by the interaction between the laser and the material. [ABSTRACT FROM AUTHOR]

In order to solve the difficulties with the observation of the ablation zone and the many factors that affect the dynamic evolution process of the ablation zone, the structural morphology and dynamic evolution process of the ablation zone in the process of water-jet assisted laser machining Korean pine (Pinus koraiensis) were studied. Based on the DFLUX subprogram, a compound heat source model was established. Under the comprehensive consideration of heat conduction, heat convection, heat radiation, and thermal physical properties varying with temperature, the three-dimensional (3D) finite element model of the Korean pine was numerically simulated by water-jet assisted laser machining. Through numerical simulation analysis, the cross-sectional morphology of Korean pine kerf was found to be screw-shaped, and the experimental results were in good agreement with the simulation results. The dynamic evolution law of water-jet assisted laser machining of Korean pine was obtained. In addition, as the laser power increased and the cutting speed decreased, the morphology of the Korean pine kerf remained unchanged, but the structure size of the Korean pine kerf showed an increasing change. [ABSTRACT FROM AUTHOR]

Background: Glaucoma is a group of eye diseases that can damage the optic nerve and cause vision loss. A novel technology micropulse laser trabeculoplasty (MLT) can use duty-circle subvisible laser pulses to treat glaucoma. The aim of this study is to evaluate the efficacy of 360° MLT to alleviate intraocular pressure (IOP) in patients with glaucoma.Methods: This was a single-center prospective study on patients treated with 360° MLT using a Diode True-Yellow 577-nm Laser with MicroPulse technology. All the patients were recruited from the Department of Ophthalmology. Follow-up visits were carried out at 1 day, 1 week, 1 month, 3 months, 6 months, 18 months, and 36 months after the procedure. Best-corrected visual acuity (BCVA), Intraocular pressure (IOP), and vertical cup-to-disc ratio (C/D ratio) were measured during the follow-up. Repeated-measures analysis of variance (ANOVA) and Kaplan-Meier analysis were performed to evaluate the outcomes.Results: A total of 39 eyes from 25 patients were included in this study (10 men/15 women). The average age of patients was 41.47 ± 14.39 years old, and the baseline IOP was 21.13 ± 7.75 mmHg. MLT significantly reduced the IOP at 1 day (range 15.61-19.01, P = 0.0218), 3 months (range 16.47-19.22, P = 0.0390), and 6 months (range 15.38-18.56, P = 0.0332) compared with the baseline. However, by the end of the study, only 21.88% of patients demonstrated a ≥ 20% IOP reduction, while seven eyes needed further laser or surgical treatment. The IOP of glaucoma patients was significantly lower than the ocular hypertension patients at 1 month (P = 0.0124), 3 months (P = 0.0004), 18 months (P = 0.0061) and 36 months (P = 0.0119).Conclusions: Micropulse laser trabeculoplasty reduce IOP in patients with glaucoma or ocular hypertension for a short period, but its lowering efficiency is limited up to 6 months of the follow-up period. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Aeronautical Materials is the property of Editorial Board of Journal of Aeronautical Materials and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A novel technique to design a low-cost frequency-selective surface (FSS) bandpass filter is presented in this article. Wideband polarization-independent FSS bandpass filters are predominantly made of multiple microwave dielectric substrates or noncommercially available composite materials with or without active components, contributing to a very high manufacturing cost. The presented FSS filter has neither microwave substrates, nor any active devices, while it has a large controllable operational frequency band, which can support all polarizations, due to its symmetrical configuration. To the best of our knowledge, such a polarization-independent wideband bandpass response has never been achieved by any low-cost fully metallic FSS filter. The proposed FSS filter is made of three thin metal sheets composed of an engineered metallic substrate (EMS) and a metallic orthogonal dipole resonator (ODR). The EMS is responsible for ensuring the mechanical integrity of the filter without imposing electromagnetic (EM) restrictions throughout the desired frequency band. The integration of EMS and ODRs realizes a fully controllable wideband bandpass verified thorough circuital and modal analyses. According to the predicted and measured results, the FSS filter has a large bandwidth of around 31%, extending from 8.76 to 11.96 GHz with sharp roll-offs for the normal incidence. Simulated and measured results show a low sensitivity of the FSS filter response to oblique angles of incidence for both TM and TE polarizations. [ABSTRACT FROM AUTHOR]

From a macro perspective, inventor networks tend to generate remarkably stable structures over time. At the same time, we observe highly dynamic processes at the micro level, in terms of inventor entries and exits as well as formations and terminations of collaborative relationships between them. In order to explain this—at least at the first glance—contradicting pattern, we investigate processes at the intermediate network level. Our analysis draws upon co-patenting data for the entire population of West German inventors in the field of laser technology research from the onset of the technology in the early 1960s over a period of 45 years. Our findings suggest that the key factor for maintaining structural stability of networks is that directly linked partners of inventors with stabilizing properties—so-called 'key players'—take over this function in a subsequent period. We show that processes at the intermediate network level provide new insights on the co-existence of micro fluidity and macro stability in complex adaptive systems. [ABSTRACT FROM AUTHOR]

Blood vessels are one of the most essential organs, which nourish all tissues in our body. Once there are intravascular plaques or vascular occlusion, other organs and circulatory systems will not work properly. Therefore, it is necessary to detect abnormal blood vessels by intravascular imaging technologies for subsequent vascular treatment. The emergence of lasers and fiber optics promotes the development of intravascular imaging and treatment. Laser imaging techniques can obtain deep vascular images owing to light scattering and absorption properties. Moreover, photothermal and photomechanical effects of laser make it possible to treat vascular diseases accurately. In this review, we present the research progress and applications of laser techniques in intravascular imaging and treatment. Firstly, we introduce intravascular optical coherent tomography and intravascular photoacoustic imaging, which can obtain various information of plaques. Multimodal intravascular imaging techniques provide more information about intravascular plaques, which have an essential influence on intravascular imaging. Secondly, two laser techniques including laser angioplasty and endovenous laser ablation are discussed for the treatment of arterial and venous diseases, respectively. Finally, the outlook of laser techniques in blood vessels, as well as the integration of laser imaging and treatment are prospected in the section of discussions. [ABSTRACT FROM AUTHOR]

Tissue engineering provides a new approach for the treatment of osteochondral defects. However, the lack of an ideal double-layer scaffold with osteochondral-biomimetic microenvironment and interface similar to native articular tissue greatly limits clinical translation. Our current study developed a double-layer acellular osteochondral matrix (AOM) scaffold with natural osteochondral-biomimetic microenvironment and interface by integrating ultraviolet (UV) laser and decellularization techniques. The laser parameters were optimized to achieve a proper pore depth close to the osteochondral interface, which guaranteed complete decellularization, sufficient space for cell loading, and relative independence of the chondrogenic and osteogenic microenvironments. Gelatin-methacryloyl (GelMA) hydrogel was further used as the cell carrier to significantly enhance the efficiency and homogeneity of cell loading in the AOM scaffold with large pore structure. Additionally, in vitro results demonstrated that the components of the AOM scaffold could efficiently regulate the chondrogenic/osteogenic differentiations of bone marrow stromal cells (BMSCs) by activating the chondrogenic/osteogenic related pathways. Importantly, the AOM scaffolds combined with BMSC-laden GelMA hydrogel successfully realized tissue-specific repair of the osteochondral defects in a knee joint model of rabbit. The current study developed a novel double-layer osteochondral biomimetic scaffold and feasible strategy, providing strong support for the tissue-specific repair of osteochondral defects and its future clinical translation.

In order to explore the capture of two types of particles with different refractive-indexes with focused partially coherent Lommel-Gaussian beam (PCLGB), we numerically derived the expressions of the intensity, and its distribution is also simulated. We found that the focused PCLGB is able to capture two high refractive-index particles at different positions on the focal plane and a low refractive-index particle at the focus, respectively. when the orbital angular momentum (OAM)quantum number, lens focal length, asymmetry parameter decreased, and the spatial correlation length and beam waist increased, the transverse gradient force of the focused PCLGB increased; when the OAM quantum number, lens focal length, asymmetry parameter, spatial correlation length decreased and the beam waist increased, the axial gradient force and scattering force of the focused PCLGB increased. We can choose the optimum optical and lens parameters, a large range and stable trapping can be achieved. The obtained results have certain reference value for the focused PCLGB applied in micromanipulation technology and biotechnology.

Background: Pediatric dental procedures like pulpotomy and pulpectomy are commonly performed to treat pulp-related dental issues in primary teeth. The choice of instrumentation, such as traditional rotary instruments or laser technology, can impact the oral microbiota. This study aims to compare the changes in oral microbiota following pulpotomy/pulpectomy in pediatric patients treated with traditional rotary instruments versus laser technology., Materials and Methods: A total of 60 pediatric patients, aged 4-10 years, requiring pulpotomy or pulpectomy were randomly assigned to two groups: group A (traditional) and group B (laser). In group A, traditional rotary instruments were used for pulp removal, while in group B, a dental laser was utilized. Saliva and plaque samples were collected before the procedure (baseline), immediately after the procedure, and at the one-month follow-up. Microbial deoxyribonucleic acid (DNA) was extracted and analyzed using 16S ribosomal ribonucleic acid (rRNA) sequencing to assess changes in the oral microbiota., Results: At baseline, both groups exhibited similar microbial diversity and composition. However, immediate post-procedure results showed a significant decrease in microbial diversity in both groups, with group B (laser) demonstrating a more pronounced reduction. At the one-month follow-up, group A (traditional) showed a partial recovery of microbial diversity, while group B (laser) continued to exhibit lower microbial diversity compared to baseline. Notably, group B (laser) displayed a shift in microbial composition with a decrease in pathogenic species and an increase in beneficial bacteria compared to group A., Conclusion: This study highlights that both traditional rotary instruments and laser technology have a significant impact on the oral microbiota of pediatric patients following pulpotomy/pulpectomy. While both methods initially reduce microbial diversity, laser treatment appears to have a more sustained effect, favoring the growth of beneficial bacteria over time. Further research is needed to assess the long-term clinical implications of these microbiota changes for the oral health of pediatric patients., Competing Interests: There are no conflicts of interest., (Copyright: © 2024 Journal of Pharmacy and Bioallied Sciences.)

Copyright of Electronic Processing of Materials / Elektronnaya Obrabotka Materialov is the property of Institute of Applied Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)