Role of heterogenous microstructure and deformation behavior in achieving superior strength-ductility synergy in zinc fabricated via laser powder bed fusion

Zinc(Zn)is considered a promising biodegradable metal for implant applications due to its appropriate degradability and favorable osteogenesis properties.In this work,laser powder bed fusion(LPBF)additive manufacturing was employed to fabricate pure Zn with a heterogeneous microstructure and exceptional strength-ductility synergy.An optimized processing window of LPBF was established for printing Zn samples with relative densities greater than 99%using a laser power range of 80∼90 W and a scanning speed of 900 mm s−1.The Zn sample printed with a power of 80 W at a speed of 900 mm s−1 exhibited a hierarchical heterogeneous microstructure consisting of millimeter-scale molten pool boundaries,micrometer-scale bimodal grains,and nanometer-scale pre-existing dislocations,due to rapid cooling rates and significant thermal gradients formed in the molten pools.The printed sample exhibited the highest ductility of∼12.1%among all reported LPBF-printed pure Zn to date with appreciable ultimate tensile strength(∼128.7 MPa).Such superior strength-ductility synergy can be attributed to the presence of multiple deformation mechanisms that are primarily governed by heterogeneous deformation-induced hardening resulting from the alternative arrangement of bimodal Zn grains with pre-existing dislocations.Additionally,continuous strain hardening was facilitated through the interactions between deformation twins,grains and dislocations as strain accumulated,further contributing to the superior strength-ductility synergy.These findings provide valuable insights into the deformation behavior and mechanisms underlying exceptional mechanical properties of LPBF-printed Zn and its alloys for implant applications.

Toward understanding the microstructure characteristics,phase selection and magnetic properties of laser additive manufactured Nd-Fe-B permanent magnets

Nd-Fe-B permanent magnets play a crucial role in energy conversion and electronic devices.The essential magnetic properties of Nd-Fe-B magnets,particularly coercivity and remanent magnetization,are significantly infuenced by the phase characteristics and microstructure.In this work,Nd-Fe-B magnets were manufactured using vacuum induction melting(VIM),laser directed energy deposition(LDED)and laser powder bed fusion(LPBF)technologies.Themicrostructure evolution and phase selection of Nd-Fe-B magnets were then clarified in detail.The results indicated that the solidification velocity(V)and cooling rate(R)are key factors in the phase selection.In terms of the VIM-casting Nd-Fe-B magnet,a large volume fraction of theα-Fe soft magnetic phase(39.7 vol.%)and Nd2Fe17Bxmetastable phase(34.7 vol.%)areformed due to the low R(2.3×10-1?C s-1),whereas only a minor fraction of the Nd2Fe14B hard magnetic phase(5.15 vol.%)is presented.For the LDED-processed Nd-Fe-B deposit,although the Nd2Fe14B hard magnetic phase also had a low value(3.4 vol.%)as the values of V(<10-2m s-1)and R(5.06×103?C s-1)increased,part of theα-Fe soft magnetic phase(31.7vol.%)is suppressed,and a higher volume of Nd2Fe17Bxmetastable phases(47.5 vol.%)areformed.As a result,both the VIM-casting and LDED-processed Nd-Fe-B deposits exhibited poor magnetic properties.In contrast,employing the high values of V(>10-2m s-1)and R(1.45×106?C s-1)in the LPBF process resulted in the substantial formation of the Nd2Fe14B hard magnetic phase(55.8 vol.%)directly from the liquid,while theα-Fe soft magnetic phase and Nd2Fe17Bxmetastable phase precipitation are suppressed in the LPBF-processed Nd-Fe-B magnet.Additionally,crystallographic texture analysis reveals that the LPBF-processedNd-Fe-B magnets exhibit isotropic magnetic characteristics.Consequently,the LPBF-processed Nd-Fe-B deposit,exhibiting a coercivity of 656 k A m-1,remanence of 0.79 T and maximum energy product of 71.5 k J m-3,achieved an acceptable magnetic performance,comparable to other additive manufacturing processed Nd-Fe-B magnets from MQP(Nd-lean)Nd-Fe-Bpowder.

Effect of Different Laser Energy Nitriding on the Fretting Wear Performance of Zr Alloy

The zirconium(Zr)alloy fuel cladding is one of the key structural components of a nuclear reactor and the first and most important line of defense for accommodating fission products.During the operation of nuclear reactors,Zr alloy fuel cladding is subjected to extreme harsh environments,such as high temperature,high pressure and high flow rate for a long period of time.The wear and corrosion resistance of Zr alloys is important for the safe operation of nuclear reactors.Surface modification can effectively improve the corrosion and wear resistance of fuel cladding.Compared with coating technology,nitriding technology does not have problems for bonding between the coating and the substrate.Current research on surface nitriding of Zr alloys mainly focuses on plasma nitriding and ion implantation techniques.Research on laser nitriding of Zr alloy surfaces and their fretting wear characteristics is scarce.In this study,the surface of Zr alloy was treated with laser nitriding at different laser energies.The microstructure of Zr alloy treated with different laser energies and its fretting wear performance were studied.The results showed that after nitriding with different laser energies,the surface of the Zr alloy showed a typical molten state after melting,vaporizing and cooling under the thermal effect of the laser,and this state was more obvious with the increase of the laser energy.At the same time,doping of N atoms and formation of the ZrN phase led to different cooling rates in the molten zone that produced large tensile stresses after cooling.This led to cracks on the surface of Zr alloys after laser nitriding at different energies,and the crack density increased with increasing laser energy.This also led to an increase in the surface roughness of the Zr alloy with increasing laser energy after laser nitriding treatment.Due to the presence of water in the industrial nitrogen,nitrides were generated on the surface of the sample along with some oxides.When the laser energy was 100 mJ,there was no ZrN generation,and N existed mainly as a diffusion layer within the Zr alloy substrate.ZrN generated when the laser energy reached 200 mJ and above,which increased with the increase of laser energy.Due to the generation of ZrN phase and the presence of some oxides,the surface Vickers hardness of Zr alloys after laser nitriding treatment at different energies increased by 37.5%compared to Zr alloys.After laser nitriding treatment,the wear mechanism of Zr alloys changed.For the untreated Zr alloys,the wear mechanism was dominated by delamination and spalling wear,accompanied by oxidative and abrasive wear.The phenomenon of delamination and peeling decreased with the increase of laser energy.Wear mechanisms changed to predominantly abrasive wear with oxidative wear and delamination spalling.The wear volume of sample nitriding with laser energy 400 mJ was reduced by 46.5%compared with that of untreated Zr alloy.

Flexible ureteroscopic treatment of kidney stones: How do the new laser systems change our concepts?

Objective: Flexible ureteroscopy (fURS) has become a widely accepted and effective technique for treating kidney stones. With the development of new laser systems, the fURS approach has evolved significantly. This literature review aims to examine the current state of knowledge on fURS treatment of kidney stones, with a particular focus on the impact of the latest laser technologies on clinical outcomes and patient safety.Methods: We conducted a search of the PubMed/PMC, Web of Science Core Collection, Scopus, Embase (Ovid), and Cochrane Databases for all randomized controlled trial articles on laser lithotripsy in September 2023 without time restriction.Results: We found a total of 22 relevant pieces of literature. Holmium laser has been used for intracavitary laser lithotripsy for nearly 30 years and has become the golden standard for the treatment of urinary stones. However, the existing holmium laser cannot completely powder the stone, and the retropulsion of the stone after the laser emission and the thermal damage to the tissue have caused many problems for clinicians. The introduction of thulium fiber laser and Moses technology brings highly efficient dusting lithotripsy effect through laser innovation, limiting pulse energy and broadening pulse frequency.Conclusion: While the holmium:yttrium-aluminum-garnet laser remains the primary choice for endoscopic laser lithotripsy, recent technological advancements hint at a potential new gold standard. Parameter range, retropulsion effect, laser fiber adaptability, and overall system performance demand comprehensive attention. The ablation efficacy of high-pulse-frequency devices relies on precise targeting, which may pose practical challenges.

Kinetics of dense plasma in the field of short laser pulses:A generalized approach

A generalized kinetic model of atomic level populations in an optically dense plasma excited by laser pulses of arbitrary duration is formulated and studied.This model is based on a nonstationary expression for the probability of excitation of an atomic transition and takes into account the effects of laser pulse penetration into an optically dense medium.A universal formula for the excitation probability as a function of time and propagation length is derived and applied to the case of a Lorentzian spectral profile of an atomic transition excited by a laser pulse with a Gaussian envelope.The features of nonstationary excitation probabilities are presented for different optical depths of the plasma,laser pulse durations,and carrier frequencies.The formulas derived here will be useful for the description of atomic populations excited by laser pulses under realistic conditions of dense plasmas.

On the generation of high-quality Nyquist pulses in mode-locked fiber lasers

Nyquist pulses have wide applications in many areas,from electronics to optics.Mode-locked lasers are ideal platforms to generate such pulses.However,how to generate high-quality Nyquist pulses in mode-locked lasers remains elusive.We address this problem by managing different physical effects in mode-locked fiber lasers through extensive numerical simulations.We find that net dispersion,linear loss,gain and filter shaping can affect the quality of Nyquist pulses significantly.We also demonstrate that Nyquist pulses experience similariton shaping due to the nonlinear attractor effect in the gain medium.Our work may contribute to the design of Nyquist pulse sources and enrich the understanding of pulse shaping dynamics in mode-locked lasers.

A comprehensive review on the processing-property relationships of laser strengthened magnesium

Among the existing series of softer metals,magnesium(Mg)has attracted much attention due to its impressive strength-to-weight ratio.However,due to its ease of deformability,Mg tends to suffer from rapid degradation in a wide variety of abrasive and electrochemical environments.One method of improving its surface properties is through surface modification techniques.Among the existing techniques,laser shock peening(LSP)has been one of the most widely utilized processes due to its surface-hardening-like effects.Despite this understanding,a comprehensive review has yet to exist that encapsulates the strengthening mechanism of LSP for Mg and its influence in degradation environments.This review aims to encapsulate the existing research around the LSP field for Mg.Specifically,an understanding of the surface-strengthening effects in relation to its mechanical,tribological,corrosion,and tribo-corrosion characteristics is elucidated.Additionally,the feasibility of LSP for Mg materials in critical industries is also discussed.Through this work,a novel understanding of LSP for Mg can be understood,which can provide a future direction for research in this field.

Effect of Intrauterine Laser Therapy at the IVF Success Rate on Infertile Patients with a History of IVF Failure: A Pilot Non-Blinded Study

Backgrounds: While there’s developing proof aimed toward improving embryo implantation thru a focal point on great development, restrained studies have been performed on enhancing endometrial receptivity. Intrauterine Laser Therapy (LT) can be powerful in selling endometrial cell proliferation, therefore enhancing the achievement of assisted reproductive techniques (ART). The contemporary look at aimed to research the effectiveness of effective intrauterine lasers in growing endometrial thickness and the achievement of being pregnant rate. Materials and Methods: In the current clinical randomized trial (RTC) study, the infertile women (20 - 42 years old) referred to the infertility clinic in 2023-2024 who were candidates for IVF treatment with recurrent implantation failure (RIF) history were included. The patients were divided into two main groups: the intervention group;low level laser therapy (LLLT) after hormone administration) (n = 52) and the control group (hormone administration without LT) (n = 52). The IVF success rate and change in endometrial thickness before and after the LT were compared in groups. Results: There was a significant difference between groups (p Conclusion: It appears that the incorporation of Intrauterine LT in the realm of infertility could significantly impact as a novel supplementary treatment in improving endometrial receptivity and pregnancy rate.

Transperineal laser ablation of the prostate as a treatment for benign prostatic hyperplasia and prostate cancer: The results of a Delphi consensus project

Objective: To evaluate transperineal laser ablation (TPLA) with Echolaser® (Echolaser® TPLA, Elesta S.p.A., Calenzano, Italy) as a treatment for benign prostatic hyperplasia (BPH) and prostate cancer (PCa) using the Delphi consensus method.Methods: Italian and international experts on BPH and PCa participated in a collaborative consensus project. During two rounds, they expressed their opinions on Echolaser® TPLA for the treatment of BPH and PCa answering online questionnaires on indications, methodology, and potential complications of this technology. Level of agreement or disagreement to reach consensus was set at 75%. If the consensus was not achieved, questions were modified after each round. A final round was performed during an online meeting, in which results were discussed and finalized.Results: Thirty-two out of forty invited experts participated and consensus was reached on all topics. Agreement was achieved on recommending Echolaser® TPLA as a treatment of BPH in patients with ample range of prostate volume, from <40 mL (80%) to >80 mL (80%), comorbidities (100%), antiplatelet or anticoagulant treatment (96%), indwelling catheter (77%), and strong will of preserving ejaculatory function (100%). Majority of respondents agreed that Echolaser® TPLA is a potential option for the treatment of localized PCa (78%) and recommended it for low-risk PCa (90%). During the final round, experts concluded that it can be used for intermediate-risk PCa and it should be proposed as an effective alternative to radical prostatectomy for patients with strong will of avoiding urinary incontinence and sexual dysfunction. Almost all participants agreed that the transperineal approach of this organ-sparing technique is safer than transrectal and transurethral approaches typical of other techniques (97% of agreement among experts). Pre-procedural assessment, technical aspects, post-procedural catheterization, pharmacological therapy, and expected outcomes were discussed, leading to statements and recommendations.Conclusion: Echolaser® TPLA is a safe and effective procedure that treats BPH and localized PCa with satisfactory functional and sexual outcomes.

Developing a highly scalable synthetic strategy for 5-amino-4-nitrobenzo[1,2-c:3,4-c']bis([1,2,5]oxadiazole)1,b-dioxide(CL-18)and investigating the influence of crystal engineering and positional isomerization on its safety and laser ignition performance

5-amino-4-nitrobenzo[1,2-c:3,4-c']bis([1,2,5]oxadiazole)1,6-dioxide(CL-18)exhibits significant potential as an initiating explosive.However,its current synthesis process remains non-scalable due to low yields and safety risks.In this study,we have developed a simple and safe synthetic route for CL-18.It was synthesized from 3,5-dihaloanisole in a four-step reaction with an overall yield exceeding 60%,surpassing all reported yields in the literature.Subsequently,recrystallization of CL-18 was successfully achieved by carefully selecting appropriate solvents and antisolvents to reduce its mechanical sensitivity.Ultimately,when DMF-ethanol was employed as the recrystallization solvent system,satisfactory product yield(>90%)and reduced mechanical sensitivity(IS=15 J;FS=216 N)were obtained.Additionally,CL-18 is derived from the rearrangement of oxygen atoms on i-CL-18 furoxan,and a comparative analysis of their physicochemical properties was conducted.The thermal stability of both compounds is similar,with onset decomposition temperatures recorded at 186 and 182℃respectively.Similarly,they exhibit 5 s breaking point temperatures of 236 and 237℃.Additionally,we present novel insights into the positional-isomerization-laser-ignition performance of CL-18 and its isomer i-CL-18 using laser irradiation for the first time.Remarkably,our findings demonstrate that i-CL-18 exhibits enhanced laser sensitivity,as it can be directly ignited by a 1064 nm wavelength laser,whereas CL-18 lacks this characteristic.

Imaging through scattering layers using a near-infrared low-spatial-coherence fiber random laser

Optical memory effect-based speckle-correlated technology has been developed for reconstructing hidden objectsfrom disordered speckle patterns,achieving imaging through scattering layers.However,the lighting efficiency and fieldof view of existing speckle-correlated imaging systems are limited.Here,a near-infrared low spatial coherence fiberrandom laser illumination method is proposed to address the above limitations.Through the utilization of random Rayleighscattering within dispersion-shifted fibers to provide feedback,coupled with stimulated Raman scattering for amplification,a near-infrared fiber random laser exhibiting a high spectral density and extremely low spatial coherence is generated.Based on the designed fiber random laser,speckle-correlated imaging through scattering layers is achieved,with highlighting efficiency and a large imaging field of view.This work improves the performance of speckle-correlated imagingand enriches the research on imaging through scattering medium.

Influence of laser parameters on the microstructures and surface properties in laser surface modification of biomedical magnesium alloys

Biodegradable implants from magnesium(Mg)alloys have emerged in the biomedical field especially in the orthopedic and cardiovascular stent applications owing to their low density,high specific strength,excellent machinability,good biocompatibility,and biodegradability.The primary shortcoming of Mg-based implants is their low corrosion resistance in the physiological environment,which results in premature mechanical integrity loss before adequate healing and the production of excessive hydrogen gas,which is harmful to the body tissues and negatively affects the biocompatibility of the implant.Laser surface modification has recently received attention because it can improve the surface properties such as surface chemistry,roughness,topography,corrosion resistance,wear resistance,hydrophilicity,and thus cell response to the surface of the material.The composition and microstructures including textures and phases of laser-treated surfaces depend largely on the laser processing parameters(input laser power,laser scan velocity,frequency,pulse duration,pressure,gas circulation,working time,spot size,beam focal position,and laser track overlap)and the thermophysical properties of the substrate(solubility,melting point,and boiling point).This review investigates the impacts of various laser surface modification techniques including laser surface melting,laser surface alloying,laser cladding,laser surface texturing,and laser shock peening,and highlights their significance in improving the surface properties of biodegradable Mg alloys for implant applications.Additionally,we explore how different laser process parameters affect its composition,microstructure,and surface properties in each laser surface modification technique.

Laser speckle contrast imaging to predict the effect of temporary spinal cord stimulation in postherpetic neuralgia patients: A prospective observational study

Temporary spinal cord stimulation(tSCS)can effectively reduce the pain and severity of postherpetic neuralgia(PHN).However,there are no effective and objective methods for predicting the effects of tSCS on PHN.Laser speckle contrast imaging(LSCI)is frequently used in neurology to evaluate the effectiveness of treatment.To assess the accuracy of LSCI in predicting the impact of tSCS on PHN,14 adult patients receiving tSCS treatments for spinal nerve-innervated(C6-T2)PHN participated in this observational study.Visual analog scale(VAS)assessments and LSCI bloodflow images of the-ngers were recorded after the tSCS procedure.The results showed that the VAS scores of all patients decreased signi-cantly.Moreover,the bloodflow index(BFI)values were signi-cantly higher than they were before the procedure.Increased bloodflow and pain alleviation were positively correlated.The-ndings indicated that spinal nerve PHN(C6-T2)was signi-cantly reduced by tSCS.Pain alleviation by tSCS was positively correlated with increased bloodflow in the hand.The effect of tSCS on PHN may thus be predicted using an independent and consistent indicator such as LSCI.

Effect of three-volt moxibustion with helium-neon laser irradiation on quality of care in patients with lumbar radiculopathy spondylosis

BACKGROUND Lumbar radiculopathy spondylosis is a relatively common orthopedic disease with a high incidence rate.It most commonly occurs in the lumbar 4-5 and lumbar 5-sacral 1 vertebrae,which account for approximately 95%of cases.It mostly occurs in people aged 30-50 years old and greatly affects their quality of life.AIM To determine the effect of triple-voltage acupuncture combined with helium-neon laser irradiation on the quality of care and improvement of symptoms in patients with lumbar radiculopathy spondylolisthesis.METHODS In this study,we selected 120 patients with lumbar radiculopathy spondylosis who were treated at our hospital between June 2019 to June 2020.The patients were divided into control and observation groups according to the random number table method,with 60 patients in each group.Patients in the observation group were treated with three-volt moxibustion combined with helium-neon laser irradiation,and those in the control group were treated with lumbar traction.After 1 month of treatment,the lumbar pain scores,lumbar spine motor functions,clinical treatment effects,and nursing satisfaction of the two groups were compared.RESULTS The results showed that acupuncture combined with laser irradiation significantly improved the patients'clinical symptoms,i.e.,reduced their low back pain,significantly lower numerical rating scale pain scores in the observation group than in the control group,and better lumbar spine motility than in the control group,compared to lumbar traction.In addition,they were cared for.The treatment effectiveness rate of the observation group was 95.5%,which was significantly higher than that of the control group(81.67%).Satisfaction with care was higher than 90 points in both groups,but the difference was not statistically significant.CONCLUSION Our study provides a clinical rationale for the future treatment of patients with lumbar spine disease.However,further extensive research is needed for validation.

Bulging Distortion of Austenitic Stainless Steel Sheet on the Partially Penetrated Side of Non-Penetration Lap Laser Welding Joint

Non-penetration laser welding of lap joints in austenitic stainless steel sheets is commonly preferred in fields where the surface quality is of utmost importance.However,the application of non-penetration welded austenitic stainless steel parts is limited owing to the micro bulging distortion that occurs on the back surface of the partial penetration side.In this paper,non-penetration lap laser welding experiments,were conducted on galvanized and SUS304 austenitic stainless steel plates using a fiber laser,to investigate the mechanism of bulging distortion.A comparative experiment of DC01 galvanized steel-Q235 carbon steel lap laser welding was carried out,and the deflection and distortion profile of partially penetrated side of the sheets were measured using a noncontact laser interferometer.In addition,the cold-rolled SUS304 was subjected to heat holding at different temperatures and water quenching after bending to characterize its microstructure under tensile and compressive stress.The results show that,during the heating stage of the thermal cycle of laser lap welding,the partial penetration side of the SUS304 steel sheet generates compressive stress,which extrudes the material in the heat-affected zone to the outside of the back of the SUS304 steel sheet,thereby forming a bulge.The findings of these experiments can be of great value for controlling the distortion of the partial penetrated side of austenitic stainless steel sheet during laser non-penetration lap welding.

Effect of hydrogen fluoride and magnesium oxide on AZ31 Mg alloy/carbon fiber-reinforced plastic composite by thermal laser joining technique

Although hydrofluoric acid(HF)surface treatment is known to enhance the joining of metals with polymers,there is limited information on its effect on the joining of AZ31 alloy and carbon-fiber-reinforced plastics(CFRPs)through laser-assisted metal and plastic direct joining(LAMP).This study uses the LAMP technique to produce AZ31-CFRP joints.The joining process involves as-received AZ31,HFpretreated AZ31,and thermally oxidized HF-pretreated AZ31 alloy sheets.Furthermore,the bonding strength of joints prepared with thermally oxidized AZ31 alloy sheets is examined to ascertain the combined effect of HF treatment and thermal oxidation on bonding strength.The microstructures,surface chemical interactions,and mechanical performances of joints are investigated under tensile shear loading.Various factors,such as bubble formation,CFRP resin decomposition,and mechanical interlocking considerably affect joint strength.Additionally,surface chemical interactions between the active species on metal parts and the polar amide along with carbonyl groups of polymer play a significant role in improving joint strength.Joints prepared with surface-pretreated AZ31 alloy sheets show significant improvements in bonding strength.

Identification of Sudanese Sesame Oil Quality Using a 680 nm Semiconductor Laser Spectrometer and Other Techniques

This study investigates the optical properties of sesame oil from traditional and industrial sources using a custom-designed semiconductor laser spectrometer, UV-Vis spectroscopy, and FTIR spectroscopy. Six samples were collected from traditional presses and factories in Khartoum State and White Nile State. The spectrometer, constructed with a 680 nm semiconductor laser and various resistor values, measured the absorbance of sesame oil samples. UV-Vis spectroscopy identified absorbance peaks at 670 nm and 417 nm, corresponding to chlorophyll a and b. FTIR analysis showed nearly identical spectra among the samples, indicating similar chemical compositions. Laser spectrometer analysis revealed specific absorbance values for each sample. The results highlight the feasibility of using a 680 nm semiconductor laser for analyzing sesame oil, providing a cost-effective alternative to other wavelengths. This study demonstrates the potential of integrating traditional methods with modern spectroscopic techniques for the quality assessment of sesame oil.

Application of Endovenous Laser Treatment Combined with Foam Sclerotherapy for the Minimally Invasive Treatment of Great Saphenous Vein Varicosity

Objective:To evaluate the efficacy of endovenous laser treatment(EVLT)combined with foam sclerotherapy(FS)in the treatment of great saphenous vein varicosity(GSVV).Methods:A total of 50 patients with GSVV,treated between March 2021 and March 2024,were selected and randomly divided into two groups using a random number table.The combination group(25 cases)underwent EVLT combined with FS,while the conventional group(25 cases)underwent EVLT alone.The total effective rate,complication rate,disease severity score,and serological indicators were compared between the two groups.Results:The total effective rate in the combination group was higher,and the complication rate was lower compared to the conventional group(P<0.05).One week after surgery,the disease severity score in the combination group was lower,coagulation function indicators were better,and inflammatory factor levels were lower compared to the conventional group(P<0.05).Conclusion:EVLT combined with FS can improve the clinical efficacy in GSVV patients,prevent postoperative complications,reduce disease severity,protect patients’coagulation function,and alleviate postoperative inflammatory responses,showing significant advantages in combined surgery.

Anti-vascular endothelial growth factor drugs combined with laser photocoagulation maintain retinal ganglion cell integrity in patients with diabetic macular edema: study protocol for a prospective, non-randomized, controlled clinical trial

The integrity of retinal ganglion cells is tightly associated with diabetic macular degeneration that leads to damage and death of retinal ganglion cells,affecting vision.The major clinical treatments for diabetic macular edema are anti-vascular endothelial growth factor drugs and laser photocoagulation.However,although the macular thickness can be normalized with each of these two therapies used alone,the vision does not improve in many patients.This might result from the incomplete recovery of retinal ganglion cell injury.Therefore,a prospective,non-randomized,controlled clinical trial was designed to investigate the effect of anti-vascular endothelial growth factor drugs combined with laser photocoagulation on the integrity of retinal ganglion cells in patients with diabetic macular edema and its relationship with vision recovery.In this trial,150 patients with diabetic macular edema will be equally divided into three groups according to therapeutic methods,followed by treatment with anti-vascular endothelial growth factor drugs,laser photocoagulation therapy,and their combination.All patients will be followed up for 12 months.The primary outcome measure is retinal ganglion cell-inner plexiform layer thickness at 12 months after treatment.The secondary outcome measures include retinal ganglion cell-inner plexiform layer thickness before and 1,3,6,and 9 months after treatment,retinal nerve fiber layer thickness,best-corrected visual acuity,macular area thickness,and choroidal thickness before and 1,3,6,9,and 12 months after treatment.Safety measure is the incidence of adverse events at 1,3,6,9,and 12 months after treatment.The study protocol hopes to validate the better efficacy and safety of the combined treatment in patients with diabetic macula compared with the other two monotherapies alone during the 12-month follow-up period.The trial is designed to focus on clarifying the time-effect relationship between imaging measures related to the integrity of retinal ganglion cells and best-corrected visual acuity.The trial protocol was approved by the Medical Ethics Committee of the Affiliated Hospital of Beihua University with approval No.(2023)(26)on April 25,2023,and was registered with the Chinese Clinical Trial Registry(registration number:ChiCTR2300072478,June 14,2023,protocol version:2.0).

Curative observation and the influence on the mental status of the patients with acne scars treated with pixe12940 laser

目的：了解痤疮凹陷性瘢痕患者的心理健康状况，观察Pixel 2940激光治疗痤疮凹陷性瘢痕的疗效及对患者心理健康的影响。方法：2010年10月～2012年8月，笔者科室采用Pixel 2940激光治疗痤疮瘢痕患者39例，并在治疗前和治疗结束后1月用Cardiff痤疮心理评估量表评估患者心理状况。结果：Pixel 2940激光治疗痤疮凹陷性瘢痕有效率达94．9％，副反应少而轻；痤疮影响了患者的心理健康，患者常常感到焦虑、愤怒和自信心下降等，但治疗后心理明显好转。结论：用Pixel 2940激光治疗痤疮凹陷性瘢痕疗效稳定、副反应少，可改善患者心理健康状况。