Nd:YAG water mist laser treatment for giant gestational gingival tumor: A case report

BACKGROUND This case of gestational gingival tumor is huge and extremely rare in clinical practice.As the growth location of this gingival tumor is in the upper anterior tooth area,it seriously affects the pregnant woman's speech and food,causing great pain to the patient.The use of Nd:YGA water mist laser to remove the gingival tumor resulted in minimal intraoperative bleeding,minimal adverse reactions,and good postoperative healing,which is worthy of clinical promotion and application.CASE SUMMARY The patient,a pregnant woman,reported a large lump in her mouth on the first day of postpartum treatment.Based on medical history and clinical examination,the diagnosis was diagnosed as gestational gingival tumor.Postoperative pathological biopsy also confirmed this diagnosis.The use of Nd:YAG water mist laser to remove the tumor resulted in minimal intraoperative bleeding,clear surgical field of view,short surgical time,and good postoperative healing.CONCLUSION In comparison to traditional surgery,Nd:YAG water mist laser surgery is minimally invasive,minimizes cell damage,reduces bleeding,ensures a clear field of vision,and virtually eliminates postoperative edema,carbonization,and the risk of cross infection.It has unique advantages in oral soft tissue surgery for pregnant patients.Therefore,the clinical application of Nd:YAG water mist laser for the treatment of gestational gingival tumors is an ideal choice.

Ureteroscopy with Holmium: YAG Laser—A Initial Study in the Urology Department of the Pr Bocar Sidy Sall University Hospital of Kati

Introduction: Ureteroscopy is a minimally invasive endoscopic surgery which provides access to the ureter, pyelon and calyceal cavities via the urethra and the bladder. Laser ureteroscopy uses the laser as an energy source to treat the stone and eliminate it naturally. Minimally invasive endoscopic methods are struggling to become popular in sub-Saharan African countries, especially for the upper urinary tract. The objective of our work was to report the results of our first laser ureteroscopy experience in the department. Materials and Methods: This was a prospective and descriptive study running from December 1, 2023 to February 19, 2024. Included in our study was any case of upper urinary tract stone operated by Laser ureteroscopy. The characteristics of the lithiasis were determined by CT scan. Sterilization of urine was verified by carrying out a cytobacteriological examination of urine. Ureteral lithiasis was approached by semi-rigid ureteroscopy. Renal lithiasis was immediately addressed by flexible ureteroscopy. Ureteroscopy was coupled with a Holmium YAG laser. A double J ureteral catheter was placed after the operation. A 230 µm laser fiber was used in each case with a generator with a power of 35 watts (Storz Calculase III type). An access sheath was used in all cases of flexible ureteroscopy. The parameters studied were: sociodemographic characteristics, lithiasis (site, size, number, density, topography), type of anesthesia, duration of laser use, duration of intervention, postoperative outcomes. Data entry and analysis were carried out using the software (Word 2016 and SPSS). Result: We collected 30 cases of laser ureteroscopy. The average age was 37 years with extremes of 9 and 79 years. The male gender was more represented. The most common age group was 24-39 years old. Renal colic was the most frequent reason for admission, 12 patients (40%). On physical examination, lumbar tenderness was present in 47% (14 patients). ECBU was positive in 4 patients (13%). CT scan was performed in all our patients before the intervention. The average stone size was 12 mm and the largest was 23 mm. The majority of stones, i.e. 59% (18 patients), had a density greater than 1000 HU. The stone was unique in 19 patients (63%). The location of the stone was pyelic in 8 patients or 27%. An impact on the upper urinary tract was found in 16 of our patients or 53%. General anesthesia was used in 25 patients (83%). A digital flexible ureteroscopy was used in 24 patients and a semi-rigid ureteroscopy (URS) in 6 patients. Full-course fragmentation was the most used therapeutic method, 9 patients or 32%. The average duration of interventions was 61 minutes. Drainage by double J catheter at the end of the procedure was performed in all our patients. The length of hospitalization was 24 hours. Only one case of failure in the USSR was recorded, and one case of failure was in the semi-rigid URS. Conclusion: Laser ureteroscopy is an effective minimally invasive surgery in the management of lithiasis of the upper urinary tract. It significantly reduces the length of hospitalization. Mastery of this technique and the acquisition of the equipment necessary for its implementation is an undeniable asset in the management of renal and ureteral lithiasis.

铌酸锂用于灯泵Cr-Tm:YAG激光器的调Q与调谐(英文)

为了简化激光器结构,减少腔内损耗,首次提出利用LiNbO3电光晶体较高的色散特性,实现2μm波段可调谐激光器的调Q与调谐。将LiNbO3晶体加工成单块特殊形状的棱镜,作为主动调Q器件,用于2μm波段灯泵Cr!Tm:YAG激光器,以产生巨脉冲,该棱镜还同时具有调谐的功能。将该棱镜插入室温灯泵的Cr!Tm:YAG激光器中,实现了1.95～2.08μm范围的调Q、调谐运转,重复频率为1～5 Hz。实验结果表明,所提出的方法可行。

A Laser-Diode-Pumped Nd:YAG Laser Q-Switched with a YAG Color Center Chip

A laser-diode-pumped Nd: YAG laser Q-switched Passively with a YAG colorcenter chip has been deveolped. The Q-switched pulse output has a duration of 25-70ns,an energy of about 7.9 μJ and a repetition frequency of 1.25-5.0kHz when the laser cavityparameters and pump power are changed. The Q-switched dynamics is analyzed with therate equation theorry. The theoretical and experimental results agree well.

水平定向结晶法生长浓度渐变Yb∶YAG激光晶体及光谱性能研究

本文采用水平定向结晶(HDC)法成功生长出180 mm×81 mm×16 mm的浓度渐变Yb∶YAG激光晶体,从放肩部位和尾部分别获取了尺寸为40 mm×40 mm×7 mm、70 mm×70 mm×7 mm的Yb∶YAG激光晶体板条各两件。采用632 nm激光、偏光应力仪对晶体板条的光学性质进行检测,实验结果发现靠近晶坯自由表面的板条内部通透,无散射光路,应力较小且分布均匀,表明该晶体板条具有优异的光学质量。进一步测试分析了晶体板条不同位置处的吸收光谱,根据935 nm波长处的吸收系数计算出Yb^(3+)的掺杂浓度,发现40 mm×40 mm×7 mm的激光晶体板条中Yb^(3+)掺杂浓度沿晶体生长方向逐步增加,浓度梯度约为0.42%/cm;而70 mm×70 mm×7 mm的激光晶体板条中Yb^(3+)掺杂浓度几乎保持不变,约为4.50%。

芪参补气活血养颜汤联合Q开关Nd∶YAG激光治疗女性黄褐斑的美学效果观察

目的:探讨芪参补气活血养颜汤联合Q开关Nd∶YAG激光治疗女性黄褐斑的美学效果。方法:选取笔者医院2019年1月-2022年1月收治的80例黄褐斑女性作为研究对象,按照随机数字表法分为观察组42例(采用芪参补气活血养颜汤联合Q开关Nd∶YAG 1064 nm激光治疗)和对照组38例(采用Q开关Nd∶YAG 1064 nm激光治疗)。观察两组的临床疗效,中医症状积分,皮肤状况,黄褐斑面积及颜色,不良反应发生率。结果:治疗后,观察组患者的总有效率为97.62%,高于对照组患者的84.21%(P<0.05)。治疗后,观察组患者情绪低落、胸胁胀痛、经行乳胀、口苦咽干等上述中医症状积分均低于对照组患者(P<0.05)。治疗后,观察组黑素指数、红斑指数及皱纹指数均低于对照组(P<0.05)。治疗后,观察组黄褐斑面积及颜色评分均低于对照组(P<0.05)。治疗后,观察组患者的总不良反应发生率与对照组患者比较差异无统计学意义(P>0.05)。结论:芪参补气活血养颜汤联合Q开关Nd∶YAG1064 nm激光能够提高黄褐斑治疗的临床疗效,改善患者临床症状,改善皮肤状况,减少黄褐斑面积及颜色,安全性较高,值得临床推广。

新型Nd:YAG激光治疗中老年玻璃体混浊患者的视觉质量评价研究

目的通过新型Nd:YAG激光治疗中老年玻璃体混浊患者的视觉质量评价研究,评估新型Nd:YAG激光治疗玻璃体混浊的疗效及应用价值。方法本研究为前瞻性观察性队列研究,本研究共筛选入组47例患者54只眼,其中男性20例,女性27例,年龄30~81岁,平均年龄(58.32±10.38)岁。所有患者术前进行最佳矫正视力(BCVA)、眼压、眼B超、超广角扫描激光眼底照相、裂隙灯散瞳眼底检查、光相干断层扫描(OCT),评估患者玻璃体混浊的位置及玻璃体后脱离情况。术后2周、4周随访,记录BCVA、眼压、眼底情况。采用配对t检验方法比较治疗前后BCVA、眼压的变化,P<0.05为差异有统计学意义的标准。结果Nd:YAG激光术前患者BCVA为0~1.0,平均为(0.18±0.27),眼压为10~20mmHg,平均为(14.84±2.22)mmHg。术后4周患者BCVA为0~1.0,平均为(0.17±0.25),眼压为9~19mmHg,平均为(14.30±2.39)mmHg。统计学分析发现,术前术后视力变化无显著性差异(P=0.129),但术后眼压轻度下降,差异有统计学意义(P=0.015)。术后4周患者视觉质量满意度评价平均分为5~10分,平均为(8.10±1.18)分。82%的患者术后3天内黑点增多,98%的患者术后2周眼前遮挡黑影消失,96%的患者术后4周视觉质量明显改善。结论经新型Nd:YAG激光治疗后的中老年玻璃体混浊患者,飞蚊症症状改善明显,患者视觉质量满意度高,尤其是伴有明显weiss环患者,患者的视觉质量改善显著。

YAG laser welding with surface activating flux

YAG laser welding with surface activating flux has been investigated, and the influencing factors and mechanism are discussed. The results show that both surface activating flux and surface active element S have fantastic effects on the YAG laser weld shape, that is to obviously increase the weld penetration and D/W ratio in various welding conditions. The mechanism is thought to be the change of weld pool surface tension temperature coefficient, thus, the change of fluid flow pattern in weld pool due to the flux.

Thulium：YAG VapoEnucleation of the prostate in large glands： a prospective comparison using 70- and 120-W 2-μm lasers

This study compared the efficacy of 70- and 120-w 2-μm thulium：YAG VapoEnucleation of the prostate （ThuVEP） for patients with benign prostatic obstruction （BPO）. A prospective analysis of 84 patients with symptomatic BPO and prostatic enlargement （t〉 60 ml） who underwent either 70-w （n=44） or 120-w ThuVEP （n=40） non-randomly was carried out. Patient demographics and perioperative and 12-month follow-up data were analysed. The mean prostate volume was 79.90---27.49 ml in patients who had received 70-w ThuVEP, which was less than in those who had received 120-w ThuVEP （88.53＋-25.10; P=0.033）. The mean enucleation （resected weight/laser time, 2.16±1.21 g min-1 vs. 1.23±0.60 g min-1; P=-0.013）, operation efficiency （resected weight/total operation time, 0.76±0.35 g min-1 vs. 0.42＋-0.27 g min-1; P=-0.000） and percentage of resected tissue （66.93%±22.79% vs. 45.41%±23.33%; P=-0.000） were higher with 120-w treatment compared to 70-w ThuVEP. One patient （1.2% of total patients） （in the 120-w group） required a blood transfusion postoperatively. Sixty-one patients （73%） were available for review at the 12-month follow-up time point. The quality of life （QoL）, International Prostate Symptom Score （IPSS）, maximum urinary flow rate （Qmax）, postvoiding residual urine （PVR） and prostate volume improved significantly after treatment （P≤ 0.035） and were not significantly different between those treated with the different devices （70- and 120-w）. The median prostate volume reduction was 81.70% and 82.19% with 70- and 120-w ThuVEP, respectively. The incidence of complications was low and did not differ between groups treated with the different devices. Two patients （2.4%） （one per group） had a bladder neck contracture at the follow-up. ThuVEP is a safe and efficacious procedure for the treatment of symptomatic BPO. The incidence of complications was low with both devices. The 120-w thulium：YAG device enhances the effectiveness of Th,VEP with reeard to the oercentaee of resected tissue and the enucleation/ooeration efficiency.

A new technique for Nd:YAG laser posterior capsulotomy

AIM:To investigate the effects of a new opening pattern in neodymium:yttrium-aluminum-garnet(Nd:YAG)laser posterior capsulotomy on visual function.METHODS:This technique was conducted along a circular pattern.The energy ranged between 0.8 and1.2 mJ/pulse was consumed and mean total energy levels were 74±21 mJ(mean±standard deviation:SD,from 40 to167)and laser shots aimed at 150μm away behind a datum point and went along an imaginary line which extends 0.5 mm inside from optic margin and into the circular en bloc pattern.Vitreous stands were attached with fragment and then they were cut off by the laser after circular application.The circular fragment was completely separated from vitreous,and then this fragment was quickly sunk in intravitreal space.RESULTS:The follow-up period ranges from at least a week to 40mo,making 15.8mo on average.The procedural outcome showed 96%(74 eyes out of the 77eyes)enhancement in patients’visual acuity.Cystoid macular edema or retinal detachment was not observed in any of the patients during follow-up periods.CONCLUSION:This new technique is expected to improve the weaknesses that the conventional procedures have by adding the process to cut off vitreous stands attached with the fragment by the laser to the circular application.

Clinical usefulness of transpapillary removal of common bile duct stones by frequency doubled double pulse Nd:YAG laser

AIM: To study the efficacy and the safety of laser lithotripsy without direct visual control by using a balloon catheter in patients with bile duct stones that could not be extracted by standard technique. METHODS: The seventeen patients (7 male and 10 female; mean age 67.8 years) with difficult common bile duct (CBD) stones were not amenable for conventional endoscopic maneuvers such as sphincterotomy and mechanical lithotripsy were included in this study. Laser wavelengths of 532 nm and 1064 nm as a double pulse were applied with pulse energy of 120 mJ. The laser fiber was advanced under fluoroscopic control through the ERCP balloon catheter. Laser lithotripsy was continued until the fragment size seemed to be less than 10 mm. Endoscopic extraction of the stones and fragments was performed with the use of the Dormia basket and balloon catheter. RESULTS: Bile duct clearance was achieved in 15 of 17 patients (88%). The mean number of treatment sessions was 1.7 ± 0.6. Endoscopic stone removal could not be achieved in 2 patients (7%). Adverse effects were noted in three patients (hemobilia, pancreatitis, and cholangitis). CONCLUSION: The Frequency Doubled Double Pulse Nd:YAG (FREDDY) laser may be an effective and safe technique in treatment of difficult bile duct stones.

Role of Removing Stasis and Reducing Heat Formula in Clearance of Proximal Ureteral Calculi after Ureteroscopic Ho:YAG Laser Lithotripsy: A Prospective Randomized Study

Objective To prospectively evaluate the efficacy of Removing Stasis and Reducing Heat Formula in accelerating calculus clearance and improving lower urinary tract symptoms of patients with proximal ureteral calculi after ureteroscopic Ho:YAG laser lithotripsy. Methods A total of 138 patients with proximal ureteral calculi underwent ureteroscopic Ho:YAG laser lithotripsy by a single endocrinologist. Stone size varied from 10 to 15 mm. After operation, the patients were randomly divided into three groups: the control group(group A), tamsulosin group(group B), and Removing Stasis and Reducing Heat Formula group(group C). The treatment lasted for 4 weeks or until stone clearance. The primary and secondary outcomes of the three groups at follow-up were assessed. Results Of the 131 patients available for follow-up, 44 cases were in the group A, 45 in the group B, and 42 in the group C, respectively. The stone free rate at 2 weeks in the groups B and C were significantly higher than that in the group A(95.56%, 97.62% vs. 79.55%; all P<0.05). The ureteral colic rate and mean time of fragment expulsion were significantly reduced in the groups B(4.44% and 7.86±4.99 days) and C(2.43% and 6.76±4.37 days) compared with the group A(22.73% and 11.54±9.89 days, all P<0.05). On the day of double-J ureteric stent removal, the group C differed significantly from the group A in the total International Prostate Symptom Score, irritative subscore, obstructive subscore, and quality of life score(all P<0.05). Conclusion Removing Stasis and Reducing Heat Formula in the medical expulsive therapy might be an effective modality for patients with calculus in the proximal uretera after ureteroscopic Ho:YAG laser lithotripsy.

Comparison of laser iridotomy using short duration532-nm Nd: YAG laser (PASCAL) vs conventional laser in dark irides

AIM: To evaluate the outcome of laser iridotomy using532-nm Nd: YAG laser(PASCAL) with short pulse duration and Nd: YAG laser compared to conventional combined laser iridotomy.METHODS: Retrospective, nonrandomized, comparative case series. Forty-five eyes of 34 patients underwent laser iridotomy. Twenty-two eyes underwent iridotomy using short duration PASCAL and Nd: YAG laser, and 23 eyes underwent iridotomy using conventional combined laser method. The average settings of PASCAL were60 μm and 700-900 m W with a short duration of 0.01 s to reduce the total applied energy. The conventional laser was 50 μm and 700-900 m W for 0.1s. After photocoagulation with these laser, the Nd: YAG laser was added in each group. Endothelial cell counts of preiridotomy and 2mo after iridotomy were measured and compared.RESULTS: All eyes completed iridotomy successfully.The total energy used in the PASCAL group was 1.85 ±1.17 J. Compared to conventional laser 13.25 ±1.67 J, the energy used was very small due to the short exposure time of PASCAL. Endothelial cell counts were reduced by0.88% in the PASCAL group and 6.72% in the conventional laser group(P =0.044). The change in corneal endothelial cell counts before and after iridotomy was significant in conventional combined laser iridotomy group(P =0.004).CONCLUSION: Combined PASCAL and Nd:YAG laseriridotomy is an effective and safe technique in the dark brown irides of Asians. Furthermore, the short duration of exposure in PASCAL offers the advantages of reducing the total energy used and minimizing the corneal damage.

Microstructure,properties and first principles calculation of titanium alloy/steel by Nd: YAG laser self-fluxing welding

The experiment of Nd： YAG pulsed laser self-fluxing welding for 304 stainless steel/Ti6Al4V titanium alloy dissimilar metal was carried out. The microstructure properties of welded joint were analyzed by SEM, EDS and XRD. The equilibrium lattice constants, enthalpies of formation, cohesive energies, mechanical properties, Debye temperatures and valence electron structures of Ti-Fe intermetallic compounds （IMCs） were calculated by the first principle pseudopotential plane wave method based on density functional theory （DFT）. According to the thermodynamic data of Ti-Fe-Cr compounds, the Gibbs free energy per mole of compound at different temperatures was calculated and their thermal stability was compared. The results show that there are no macroscopic cracks in the welded joints, and the IMCs distributed evenly along the welding interface exhibits 3 distinct layers of microstructure with different colors. The welds interface generates IMCs of TiFe, TiFe 2 and a small amount of Ti 5Cr 7Fe 17 IMCs. Ti-Fe IMCs with high thermodynamic stability and easy alloying formation. The results of Gibbs free energies show that the sequence of precipitates in the interface is Ti 5Cr 7Fe 17 , TiFe 2 and TiFe in high temperature during the metallurgical reaction. The G/B values of Ti-Fe IMCs are greater than the critical value of 0.5, indicating that it is an intrinsic brittleness.

A high-power high-stability Q-switched green laser with intracavity frequency doubling using a diode-pumped composite ceramic Nd:YAG laser

We successfully obtain a high-average-power high-stability Q-switched green laser based on diode-side-pumped composite ceramic Nd：YAG in a straight piano-concave cavity. The temperature distribution in composite ceramic Nd：YAG crystal is numerically analyzed and compared with that of conventional Nd：YAG crystal. By using a composite ceramic Nd：YAG rod and a type-II high gray track resistance KTP （HGTR-KTP） crystal, a green laser with an average output power of 165 W is obtained at a repetition rate of 25 kHz, with a diode-to-green optical conversion of 14.68%, and a pulse width of 162 ns. To the best of our knowledge, both the output power and optical-to-optical efficiency are the highest values for green laser systems with intracavity frequency doubling of this novel composite ceramic Nd：YAG laser to date. The power fluctuation at around 160 W is lower than 0.3% in 2.5 hours.

Treatment of Special Renal Colic with Ureteroscope and Holmium YAG Laser

Objective To investigate the method of emergent relief of special renal colic and treatment of ureter diseases causing renal colic. Methods By analyzing 63 cases of special renal colic treated with ureteroscope and Holmium YAG laser. Results 61 cases of renal colic were relieved in a short period of time and the original ureter diseases causing renal colic were cured. Conclusion Special renal colic could be treated with ureteroscope and Holmium YAG laser in a quick and effective manner.

PRESS FORMABILITY OF YAG LASER WELDED TRIP STEEL SHEETS

The effects of YAG laser welding conditions on mechanical properties andpress formability (bendability, stretch-formability and deep drawability) of high-strengthtransformation-induced plasticity-aided dual-phase (TDP) steel were investigated. Tensile tests andpress forming tests have been conducted for laser butt welded joints between two pieces of the samesteel. The tensile property and press formability were affected by the welding speed of 100 to1100mm/min and the energy of 6 to 9J/pulse. Excellent press formability was obtained with the energyof 6J/pulse and the welding speed of 300mm/min. It was concluded that the excellent weldability ofthe TDP steel can be ascribed to the weld joint formation.

Ureteroscopic Holmium:YAG Laser Lithotripsy for Managing Ureteral Calculi (A Report of 168 Cases)

Summary: The effectiveness and safety of ureteroscopic holmium:YAG laser lithotripsy for managing ureteral calculi was evaluated. Ureteroscopic holmium:YAG laser lithotripsy was performed in 168 ureteral calculi (upper 27 cases, middle 33 cases and lower 108 cases). The results showed that the stone-free rate was 92.6 % in the upper ureteral calculi, 93.9 % in the middle ureteral calculi and 94.4 % in the lower ureteral calculi, respectively. The complication rate was 4.8 % (8 cases). It was suggested that ureteroscopic holmium:YAG laser lithotripsy is a highly effective and safe treatment modality for managing ureteral calculi.

Pulsed Nd:YAG laser cladding of high silicon content coating on low silicon steel

A pulsed Nd：YAG （yttrium aluminum garnet） laser-based technique was employed to clad low silicon steel with preplaced Si and Fe mixed powders for high Si content. The surface morphology, microstructural evolution, phase composition, and Si distribution, within the obtained cladding coatings, were characterized by optical microscopy （OM）, field emission scanning electron microscopy （FE-SEM）, with associated energy dispersive spectroscopy （EDS）, transmission electron microscopy （TEM）, and X-ray diffraction （XRD）. The microhardness was also measured along the depth direction of the specimens, A crack- and pore-free cladding coating through excellent metallurgical bonding with the substrate was successfully prepared on low silicon steel by means of optimized single-track and multi-track laser cladding. The phases of the coating are a-Fe, T-Fe, and FeSi. The high microhardness of the lasercladding zone is considered as an increase in Si content and as the refined microstructure produced by the laser treatment. The Si contents of the cladding coatings were about 5.8wt% in the single-track cladding and 6.5wt% in the multi-track cladding, respectively.

Circular cladding waveguides in Pr:YAG fabricated by femtosecond laser inscription:Raman,luminescence properties and guiding performance

We report on the fabrication of circular cladding waveguides with cross-section diameters of 60−120μm in Pr:YAG crystal by applying femtosecond laser inscription.The fabricated waveguides present 2D guidance on the cross-section and fairly low propagation losses.Multiple high-order guiding modes are observed in waveguides with different diameters.Corresponding simulation results reveal the origin of a specific kind of guiding modes.Confocal micro-Raman(μ-Raman)experiments demonstrate the modification effects in femtosecond laser affected areas and ascertain the refractive index induced guiding mechanism.In addition,luminescence emission properties of Pr3+ions at waveguide volume are well preserved during the femtosecond laser inscription process,which may result in a potential high-power visible waveguide laser.