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. Intrauterin...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.展开更多
Influence produced by the heat effect at work of the laser instrument crystal of the semiconductor, the text designs a kind of temperature control system to the crystal of the laser instrument, using the thought and m...Influence produced by the heat effect at work of the laser instrument crystal of the semiconductor, the text designs a kind of temperature control system to the crystal of the laser instrument, using the thought and method of the classical control theory to analyze this temperature control system, and establishes mathematics model. According to mathematics model the text demonstrated the system at S field and time- area, and proposed optimizing basis to the total mark of proportion and differential parameter to con- troller PID, thus proposed a kind of temperature control scheme. And the thermostatically system is simulated by MATLAB.展开更多
Photothermal therapy(PTT)using near-infrared(NIR)light for tumor treatment has triggered extensive attentions because of its advantages of noninvasion and convenience.The current research on PTT usually uses lasers in...Photothermal therapy(PTT)using near-infrared(NIR)light for tumor treatment has triggered extensive attentions because of its advantages of noninvasion and convenience.The current research on PTT usually uses lasers in the first NIR window(NIR-I;700–900 nm)as irradiation source.However,the second NIR window(NIR-II;1000–1700 nm)especially NIRIIa window(1300–1400 nm)is considered much more promising in diagnosis and treatment as its superiority in penetration depth and maximum permissible exposure over NIR-I window.Hereby,we propose the use of laser excitation at 1275 nm,which is approved by Food and Drug Administration for physical therapy,as an attractive technique for PTT to balance of tissue absorption and scattering with water absorption.Specifically,CuS-PEG nanoparticles with similar absorption values at 1275 and 808 nm,a conventional NIR-I window for PTT,were synthesized as PTT agents and a comparison platform,to explore the potential of 1275 and 808 nm lasers for PTT,especially in deep-tissue settings.The results showed that 1275 nm laser was practicable in PTT.It exhibited much more desirable outcomes in cell ablation in vitro and deep-tissue antitumor capabilities in vivo compared to that of 808 nm laser.NIR-IIa laser illumination is superior to NIR-I laser for deep-tissue PTT,and shows high potential to improve the PTT outcome.展开更多
Low-level laser therapy(LLLT) may have an effect on the pain associated with orthodontic treatment. The aim of this study was to evaluate the effect of LLLT on pain and somatosensory sensitization induced by orthodont...Low-level laser therapy(LLLT) may have an effect on the pain associated with orthodontic treatment. The aim of this study was to evaluate the effect of LLLT on pain and somatosensory sensitization induced by orthodontic treatment. Forty individuals(12–33 years old; mean ± standard deviations: 20.8 ± 5.9 years) scheduled to receive orthodontic treatment were randomly divided into a laser group(LG) or a placebo group(PG)(1:1). The LG received LLLT(810-nm gallium-aluminium-arsenic diode laser in continuous mode with the power set at 400 mW, 2 J·cm–2) at 0 h, 2 h, 24 h, 4 d, and 7 d after treatment, and the PG received inactive treatment at the same time points. In both groups, the non-treated side served as a control. A numerical rating scale(NRS) of pain, pressure pain thresholds(PPTs), cold detection thresholds(CDTs), warmth detection thresholds(WDTs), cold pain thresholds(CPTs), and heat pain thresholds(HPTs) were tested on both sides at the gingiva and canine tooth and on the hand. The data were analysed by a repeated measures analysis of variance(ANOVA). The NRS pain scores were significantly lower in the LG group(P = 0.01). The CDTs,CPTs, WDTs, HPTs, and PPTs at the gingiva and the PPTs at the canine tooth were significantly less sensitive on the treatment side of the LG compared with that of the PG(P < 0.033). The parameters tested also showed significantly less sensitivity on the nontreatment side of the LG compared to that of the PG(P < 0.043). There were no differences between the groups for any quantitative sensory testing(QST) measures of the hand. The application of LLLT appears to reduce the pain and sensitivity of the tooth and gingiva associated with orthodontic treatment and may have contralateral effects within the trigeminal system but no generalized QST effects. Thus, the present study indicated a significant analgesia effect of LLLT application during orthodontic treatment.Further clinical applications are suggested.展开更多
Traumatic brain injury is a major health concern worldwide with massive financial and social impact. Conventional treatments primarily focus on the prevention of further damage to the brain parenchyma, while failing t...Traumatic brain injury is a major health concern worldwide with massive financial and social impact. Conventional treatments primarily focus on the prevention of further damage to the brain parenchyma, while failing to address the already existent symptoms. Previous clinical studies have shown that Low Level Laser Therapy (LLLT) can significantly reduce pain and induce temporary vasodilation in capillaries, which the authors hypothesize can be used to improve the quality of life in TBI patients by treating their current symptoms, which are predominately migraine-like headaches. This case report illustrates the use of LLLT in the treatment of a patient with a TBI and the great clinical success achieved in the reduction of pain, as measured by VAS—achievable within five treatments of 10 minutes in duration.展开更多
Background : Osteoporosis can make bone repair difficult. Low-level laser therapy( LLLT) has been shown to be a promising tool for bone neoformation. This study aimed to analyze the effect of LLLT on calvaria bone def...Background : Osteoporosis can make bone repair difficult. Low-level laser therapy( LLLT) has been shown to be a promising tool for bone neoformation. This study aimed to analyze the effect of LLLT on calvaria bone defects of ovariectomized rats using stereology. Methods : Fifty-four Wistar rats were subjected to bilateral ovariectomy, and bone defects were created in calvaria after 150 days. The animals were divided into nine groups(n = ?6 per group), and 24 hours after the bone defects were created they received three, six or 12 sessions of LLLT at 0, 20 or 30 J/cm 2, using a 780-nm low-intensity GaAlAs laser. One-way ANOVA followed by Tukey ' s post hoc test was used for data processing. A difference of P < 0.05 was considered statistically significant. The parameters evaluated were osteocyte density( Nv_(ost)), total osteocyte number( Nto ost), trabecular surface density( Sv_t), and trabecular surface area( Sa_t). Results : Data obtained showed that Nto ost, Sv t, and Sa t in group G2 rats were significantly different from G1(0 J/cm^2)( P < 0.05). Compared to group G4, G5 presented higher values for the parameters Sv t and Sa t, and G6 presented significantly higher values for almost all the analyzed parameters( Nv _(ost), Nto_(ost), Sv_t, and Sa t)( P < 0.05). Compared to group G7, G8 showed a higher value only for the parameter Sa t, and G9 showed significantly higher values for parameters Nv ost, Nto ost, Sv_t, and Sa_t. Conclusion : We conclude that LLLT stimulated bone neoformation and contributed to an increase in the total number of osteocytes, especially with a laser energy density of 30 J/cm^2 given for six and 12 sessions.展开更多
BACKGROUND Routine preclinical interventions for patients with chronic periodontitis such as supragingival cleaning and subgingival curettage,establishing a balanced occlusal relationship,and irrigation with 3%hydroge...BACKGROUND Routine preclinical interventions for patients with chronic periodontitis such as supragingival cleaning and subgingival curettage,establishing a balanced occlusal relationship,and irrigation with 3%hydrogen peroxide can relieve the symptoms to some extent.However,there is room for improvement in the overall effect.For example,Er:YAG lasers can quickly increase the temperature of the irradiated tissue,effectively eliminate dental plaque and calculus,reduce periodontal pockets,adjust periodontal microecology,and reduce the gingival sulcus.The content of factors in the liquid,and then achieve the purpose of treatment.AIM The aim was evaluate the effect of Er:YAG laser-assisted routine therapy on the periodontal status in chronic periodontitis.METHODS Between October 2018 and January 2020,106 patients with chronic periodontitis in our hospital were randomly assigned to either the study or control group,with 53 patients in each group.The control group underwent routine therapy,and the study group underwent Er:YAG laser therapy in addition to routine therapy.We evaluated the treatment outcome in both groups.Periodontal status was determined by clinical attachment loss(CAL),gingival index(GI),periodontal probing depth(PD),dental plaque index(PLI),and sulcular bleeding index(SBI),inflammatory factors in the gingival crevicular fluid,tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),IL-8],and colony forming units(CFUs).RESULTS Total effectiveness in the study group(94.34%)was higher than that in the control group(79.25%,P<0.05).The clinical parameters in the study group(PD,5.28±1.08 mm;CAL,4.81±0.79 mm;SBI,3.37±0.59;GI,1.38±0.40;PLI,2.05±0.65)were not significantly different from those in the control group(PD,5.51±1.14 mm;CAL,5.09±0.83 mm;SBI,3.51±0.62;GI,(1.41±0.37;PLI,1.98±0.70)before treatment(P>0.05).However,after treatment,the parameters in the study group(PD,2.97±0.38 mm;CAL,2.71±0.64 mm;SBI,2.07±0.32;GI,0.51±0.11;PLI,1.29±0.34)were lower than those in the control group(PD,3.71±0.42 mm;CAL,3.60±0.71 mm;SBI,2.80±0.44;GI,0.78±0.23;PLI,1.70±0.51)(P<0.05).Differences in crevicular TNF-α,IL-6,and IL-8 levels in the study(TNF-α,7.82±3.43 ng/mL;IL-6,11.67±2.59 ng/mL;IL-8,12.12±3.19 pg/mL)and control groups(TNF-α,9.06±3.89 ng/ml,IL-6,12.13±2.97 ng/mL,IL-8,10.99±3.30 pg/mL)before therapy(P>0.05)were not significant.Following treatment,the parameters were significantly lower in the study group(TNF-α,2.04±0.89 ng/mL;IL-6,4.60±1.26 ng/mL;IL-8,3.15±1.08 pg/mL)than in the control group(TNF-α,3.11±1.07 ng/mL;IL-6,6.25±1.41 ng/mL;IL-8,4.64±1.23 pg/mL,P<0.05).The difference in the CFU of the study group[(367.91±74.32)×104/mL and control group(371.09±80.25)×104/mL]before therapy was not significant(P>0.05).The CFU decreased in both groups following therapy,however,the CFU values were lower in the study group[(36.09±15.26)×104/mL]than in the control group[(45.89±18.08)×104/mL](P<0.05).CONCLUSION Combining Er:YAG lasers with routine measures significantly improved the overall periodontal therapy outcomes by improving periodontal status and reducing oral levels of inflammatory factors and CFUs.展开更多
AIM: To validate the protocol described here to be used in future clinical trials related to the effect of laser therapy on dental pulp. METHODS: Histologically treated samples from eight human healthy premolar teeth ...AIM: To validate the protocol described here to be used in future clinical trials related to the effect of laser therapy on dental pulp. METHODS: Histologically treated samples from eight human healthy premolar teeth obtained from the middle root level were distributed in four groups: group 1(G1) absolute control; group 2(G2) only laser irradiation; group 3(G3) exposed only to orthodontics; and group 4(G4) treated with orthodontics and laser. Laser treatment was performed at 830 nm wavelength, 100 mW(energy 80 J/cm2, 2.2 J), for 22 s in the vestibular surface and 22 s in the palatal surface, 1 mm away from the dental root mucosa. Three staining methods were performed: hematoxylin-eosin(HE), Masson's Trichrome method and Gomori's method.RESULTS: The pulp histology parameters were evaluated and the results classified in to 3 parts: an inflammatory response, soft tissue response(dental pulp) and hard tissue response(dentin and predentin). There was no inflammation(chronic or acute) in any of the evaluated groups. The zones of pulp necrosis were found in one premolar of G3 and in one of G4; in groups G2 and G4 there was higher angiogenesis than in the other two groups. G4 group presented the highest level of vascularization. A reduced nerve density was observed in G3. A G2 specimen showed increased nerve density. A higher rate of calcification was observed in G1 compared to G2. Denticles, either real or false, were observed in G1, G2 and G3. Sclerosis of dentin and focal dentin loss was observed among all the groups. Secondary dentin was present in one sample in G1 and G2. A necrosis zone was found in one sample of G3 and G4. No differences between groups were observed in the odontoblast irregularity layer but the layer was wider in the group treated with laser only. A notable difference was detected in reduction of the cell-free layer between the groups G1 and G4. The findings in pulp tissue favor its adaptative response against dental movement induced by orthodontics. No definitive conclusions may be derived as this is a pilot study. CONCLUSION: The protocol described here was shown to be an effective method to evaluate changes in dental pulp submitted to low level laser in teeth under orthodontic movement.展开更多
At present, the only FDA approved treatment for ischemic strokes is intravenous administration of tissue plasminogen activator within 4.5 hours of stroke onset. Owing to this brief window only a small percentage of pa...At present, the only FDA approved treatment for ischemic strokes is intravenous administration of tissue plasminogen activator within 4.5 hours of stroke onset. Owing to this brief window only a small percentage of patients receive tissue plasminogen activator. Transcranial laser therapy has been shown to be effective in animal models of acute ischemic stroke, resulting in significant improvement in neurological score and function. NEST-1 and NEST-2 clinical trials in human patients have demonstrated the safety and positive trends in efficacy of transcranial laser therapy for the treatment of ischemic stroke when initiated close to the time of stroke onset. Combining intravenous tissue plasminogen activator treatment with transcranial laser therapy may provide better functional outcomes. Statins given within 4 weeks of stroke onset improve stroke outcomes at 90 days compared to patients not given statins, and giving statins following transcranial laser therapy may provide an effective treatment for patients not able to be given tissue plasminogen activator due to time constraints.展开更多
The majority of existing high-power laser therapeutic instruments employ a single wavelength for a single target;thus,they do not meet the requirements for clinical treatment.Therefore,this study designs an optical sy...The majority of existing high-power laser therapeutic instruments employ a single wavelength for a single target;thus,they do not meet the requirements for clinical treatment.Therefore,this study designs an optical system for a dual-wavelength high-power laser therapeutic device with a variable spot size.The waist of the short arm of the optical cavity and the G1G2 parameter(G-parameter equivalent cavity method)is calculated using MATLAB software,the spot size and divergence angle on the lens are calculated using an ABCD matrix,and the distance between the treatment spot at different spot sizes and the transformation lens is calculated in order to design the treatment handpiece.Experiments are conducted to analyze the stability at an output power of 532 nm before beam combination and the power loss after beam combination.The results show that the output power stability of the 532-nm beam varies by less than 2%over 150 min,and the loss of both wavelengths is less than 20%,which meets the clinical requirements of the system.The safety performance can meet the requirements of national general standards for medical electrical safety.The proposed dual-wavelength laser therapy instrument has both visible wave and near-infrared wave characteristics;thus,it can accurately target both superficial vessels and vessels with a larger diameter and deeper position.This therapeutic device has the advantages of simple operation,stable and reliable laser output,high security and strong anti-interference ability,and meets the comprehensive clinical treat-ment demands of vascular diseases.展开更多
Aggressive cytoreduction can prolong survival in patients with unresectable liver metastases(LM)from neuroendocrine neoplasms(NEN),and minimally invasive,liver-directed therapies are gaining increasing interest.Cathet...Aggressive cytoreduction can prolong survival in patients with unresectable liver metastases(LM)from neuroendocrine neoplasms(NEN),and minimally invasive,liver-directed therapies are gaining increasing interest.Catheter-based treatments are used in disseminated disease,whereas ablation techniques are usually indicated when the number of LM is limited.Although radiofrequency ablation(RFA)is by far the most used ablative technique,the goal of this opinion review is to explore the potential role of laser ablation(LA)in the treatment of LM from NEN.LA uses thinner needles than RFA,and this is an advantage when the tumors are in at-risk locations.Moreover,the multi-fiber technique enables the use of one to four laser fibers at once,and each fiber provides an almost spherical thermal lesion of 12-15 mm in diameter.Such a characteristic enables to tailor the size of each thermal lesion to the size of each tumor,sparing the liver parenchyma more than any other liver-directed therapy,and allowing for repeated treatments with low risk of liver failure.A recent retrospective study reporting the largest series of LM treated with LA documents both safety and effectiveness of LA,that can play a useful role in the multimodality approach to LM from NEN.展开更多
Acute renal failure has a 50% - 80% mortality rate. Currently, treatment options for this life-threatening disease are limited. Low-level laser therapy (LLLT) has been found to modulate biological activity. The aim of...Acute renal failure has a 50% - 80% mortality rate. Currently, treatment options for this life-threatening disease are limited. Low-level laser therapy (LLLT) has been found to modulate biological activity. The aim of the present study was to investigate the possible beneficial effects of laser application to stem cells in the bone marrow, on the kidneys of rats that had undergone ischemia-reperfusion injury (IRI). IRI was induced by occlusion of the renal artery to 3- and 7-month-old rats for 15 or 30 minutes. In an additional experiment IRI was applied to both kidneys for 20 min each in 2-3-month-old rats. Rats were then divided randomly into two groups of control and laser-treated. Laser therapy (Ga-Al-As 810 nm, 200 mW output for 2 min) was applied to the bone marrow 1 and 7 days post-IRI to the kidneys, and rats were sacrificed 2 weeks later. Histomorphometry and immunohistochemistry were performed on kidney sections and blood markers for kidney function. Quantitative histomorphometric analysis revealed a reduction in dilatation of the renal tubules, restored structural integrity of the renal tubules, and reduced necrosis in the laser-treated rats as compared to the control, non-laser-irradiated group. C-kit positive cell density in kidneys post-IRI and laser-treatment was significantly (p = 0.015) 3.2-fold higher compared to the control group. Creatinine and blood urea nitrogen content were significantly lower in the laser-treated rats as compared to control. It is concluded that LLLT application to the bone marrow (BM) causes a significant increase in the density of mesenchymal stem cells in the kidneys post-IRI, probably by induction of stem cells in the BM, which subsequently migrate to the IRI kidney, significantly reducing the pathological features of the kidney and increasing kidney function post IRI.展开更多
AIM:To compare the efficacy and safety between laser therapy and anti-vascular endothelial growth factor(VEGF)agents intravitreal injection monotherapy in type-1 retinopathy of prematurity(ROP)and aggressive posterior...AIM:To compare the efficacy and safety between laser therapy and anti-vascular endothelial growth factor(VEGF)agents intravitreal injection monotherapy in type-1 retinopathy of prematurity(ROP)and aggressive posterior retinopathy of prematurity(APROP).METHODS:A systematic literature search was performed in PubMed,Cochrane Library,and Embase for original comparable studies.We included studies that compare laser therapy and intravitreal injections of anti-VEGF agents monotherapy in ROP regardless of languages and publication types.RESULTS:Complication incidence was significantly higher in laser therapy group(OR:0.38;95%CI:0.19-0.75;P=0.005).Spherical equivalent(SE)was higher in laser therapy[weighted mean difference(WMD):2.40,95%CI:0.88-3.93;P=0.002].The time between treatment and retreatment was longer in laser therapy group(WMD:8.45,95%CI:5.35-11.55;P<0.00001).Recurrence incidence(OR:0.97;95%CI:0.45-2.09;P=0.93)and retreatment incidence(OR:1.24;95%CI:0.56-2.73;P=0.59)were similar in two approaches.Subgroup analysis between type-1 ROP and APROP was not significant except SE reported in the included studies(P<0.0001).CONCLUSION:This Meta-analysis outcome indicates anti-VEGF agents are as effective as laser treatment,and safer than laser in type-1 ROP and APROP.The degree of myopia in APROP is higher than type-1 ROP.More randomized controlled trials in large sample size should be conducted in the future.展开更多
Since carbon dioxide laser is excellent for incision, hemostasis, coagulation, and vaporization of soft tissues, it has been widely applied in clinical treatments as the laser knife. In these days, flexible thin hollo...Since carbon dioxide laser is excellent for incision, hemostasis, coagulation, and vaporization of soft tissues, it has been widely applied in clinical treatments as the laser knife. In these days, flexible thin hollow optical fibers transmitting mid-infrared light have been developed, and the application of carbon dioxide laser to endoscopic therapy has become possible. However, it is expected that the irradiation effect is influenced by the change in the laser power at the tip of the hollow optical fiber due to the change in the transmittance by the bending loss. The purpose of this research is to quantitatively evaluate the change in the output power and therapeutic effect by bending the hollow optical fiber in a gastrointestinal endoscope. The change in the transmittance of the hollow optical fiber due to the insertion of the fiber into the endoscope and bending of the head of the endoscope was measured. Then, the relationship between the irradiated laser power and the incision depth for a porcine stomach was investigated. As the results, the most significant decrease in the transmittance of the hollow optical fiber was caused by the insertion of the fiber into the instrument channel of the endoscope, and bending of the head of the endoscope with the angle of 90° decreased the output laser power and incision depth by 10% and 25%, respectively. Therefore, it was confirmed that the bending loss of the hollow optical fiber due to the bending of the head of the endoscope had no significant influence on the endoscopic therapy using the carbon dioxide laser.展开更多
Photothermal therapy (PTT), which utilizes light radiation to create localized heating effect in the targeted areas, is a promising solution for highly specific yet minimally invasive cancer therapy. PTT uses photothe...Photothermal therapy (PTT), which utilizes light radiation to create localized heating effect in the targeted areas, is a promising solution for highly specific yet minimally invasive cancer therapy. PTT uses photothermal agents, which are usually nanoparticles that absorb strongly in the near-infrared optical window where minimal tissue absorption occurs. Photothermal agents are also highly functionalized to target at specific tumor sites. Gold nanostar is an ideal candidate for photothermal agents, because it not only has a Surface Plasmon Resonance in the near-infrared, but also can be easily produced and purified, and is extremely versatile in the drug delivery process. In order to achieve maximum amount of localized heating, pulse lasers are usually used in laser ablation processes like photothermal therapy. However, intensive laser radiation can cause damage to regular tissues as well the nanostructures themselves. Therefore, identifying the optimal pulse duration to effectively generate localized heating in the tumorous tissues while keeping the normal tissues and the nanostructures intact is important to achieving optimal photo-therapeutic results. This manuscript provides a numerical calculation method with Comsol Multiphysics to optimize the pulse condition of the gold nanostars under photothermal therapy settings. Based on results, gold nanostar displays significant temperature heterogeneity under femtosecond and picosecond laser radiation, while nanosecond laser only induces rather uniform heating effects across the entire gold nanostar particle. This finding indicates that femtosecond laser, which is the most common type of laser used for ablation, is likely to melt the tip of the gold nanostar before the nanostar body reaches a reasonably high temperature. Picosecond and nanosecond lasers are much less likely to induce such dramatic morphology change. This study offers important insight into finding the optimal condition for photothermal therapy with maximal efficacy and minimal damage.展开更多
The use of laser therapy is one of the most effective tools in the prevention and treatment of skin ulcers. It is an effective treatment choice because it potentiates the trophic regenerative, anti inflammatory, and p...The use of laser therapy is one of the most effective tools in the prevention and treatment of skin ulcers. It is an effective treatment choice because it potentiates the trophic regenerative, anti inflammatory, and painkiller effects. This study aimed to assess the effectiveness of low level laser therapy in treating induced cutaneous ulcers in rats. An experimental study using 12 female Wistar rats (Rattus novergicus), weighing between 150 and 250 g, from the room of animal husbandry at the Center of Health Sciences of UNIFOR. Rats underwent surgery to induce cutaneous ulcer. Subsequently, the animals were divided into two randomized groups: 1) Control group;and 2) Experimental group. They received nine applications of AlGaInP laser treatment (power of 30 mW) with an intensity of 4 J/cm2, using the scan method, for 15 seconds over the entire ulcer. The cicatrization process was evaluated from the 1st to 19th postoperative (PO) day, but on alternate days. The results showed that animals treated with laser had less area of cutaneous wound than the control group from the 7th until the 17th postoperative day, highlighting the 7th and the 9th PO with a significant reduction in wound area of 28.8% (p = 0.00) and 23,5% (p = 0.01), respectively. Treatment with the AlGaInP laser was effective in the repair of cutaneous wound when compared to the control group—particularly on the 7th postoperative day.展开更多
Hyper thermal therapy using lasers is emerging as a new promising route for the cancer treatment. The tumor can be directly heated by the radiation or indirectly using gold nano particles based on plasmon resonance ph...Hyper thermal therapy using lasers is emerging as a new promising route for the cancer treatment. The tumor can be directly heated by the radiation or indirectly using gold nano particles based on plasmon resonance phenolmenon. These two possibilities are explored here by solving the space and time dependent bio-heat equation under different conditions. The knowledge of temperature profiles in the tumor region helps to bypass the painful placement of sensors for monitoring tumor’s heating by the laser. Important properties which could be useful for developing an efficient tumor therapy are introduced for the first time. It is found that the effects of metabolism consist essentially in a redefinition of the blood temperature which increases proportional to the heat of metabolism. Blood perfusion in a given tissue leads to a new characteristic length of order one or two centimeters and a blood convection parameter typically of order 30 W·m-1·K-1. Effects of these parameters are scrutinized within the resolution of the bio-heat equation under a variety of conditions. In general, space modulations of the temperature throughout biological tissues are weak but front kinetics are quite fast. Specific examples show the way to monitor the temperature rise taking into account the tumor’s nature and size.展开更多
Objective:To evaluate the effectiveness of endovenous laser therapy and conventional thera- py on the varicose of great saphenous vein.Methods:Thirty-two patients received endovenous laser thera- py and 32 patients we...Objective:To evaluate the effectiveness of endovenous laser therapy and conventional thera- py on the varicose of great saphenous vein.Methods:Thirty-two patients received endovenous laser thera- py and 32 patients were operated by conventional therapy(high ligation and stripping).The observation results of great saphenous vein(GSV)were recorded by clinical evaluation and duplex ultrasound examina- tion.And the operating time,intraoperative blood loss,time to become moveable,duration of hospitaliza- tion and degree of feeling pain were compared between the two groups.Results:Compared with conven- tional therapy,laser therapy had good curative effect with less complications and no scars and no pains. There were significant differences between the two groups(P<0.01).Conclusion:Laser therapy for varicose of great saphenous vein is better than the conventional therapy.It deserves to be widely used in clinical treatment.展开更多
In this study, we investigated the hypothesis that photobiostimulation by low-energy laser therapy (LLLT) applied to the bone marrow (BM) of myocardial infarcted rats may attenuate the scarring processes that follow m...In this study, we investigated the hypothesis that photobiostimulation by low-energy laser therapy (LLLT) applied to the bone marrow (BM) of myocardial infarcted rats may attenuate the scarring processes that follow myocardial infarction (MI). Wistar rats underwent experimental MI. LLLT (Ga-Al-As diode laser) was applied to the BM of the exposed tibia at different time intervals post-MI (4 hrs, 48 hrs and 5 days). Sham-operated infarcted rats served as control. Infarct size was significantly reduced (55%) in the laser-treated rats as compared to the control non-treated rats, at 2 weeks post-MI. A significant 3-fold increase was observed in the density of desmin immunopositive stained cells 14 days post-MI in the infarcted area of the laser-treated rats as compared to the non-laser-treated controls. The electron microscopy from the control infarcted rat hearts revealed a typical interphase area between the intact myocardium and the infarcted area, with conspicuous fibroblasts with collagen deposition dispersed among them. In rats that were laser treated (to BM), the interphase zone demonstrated cells with different intracellular structures. There was also a significant increase in the percentage of c-kit positive cells and macrophages in the circulating blood of the laser treated rats as compared to control non treated ones. In the majority of the cells clusters of myofibrils anchored to well-developed Z-lines and structures resembling the morphological characteristics of mature intact cardiomyocytes were evident. In conclusion, LLLT to the BM of rats post-MI induces cardiogenesis mainly at the borders of the infarcted area in the heart.展开更多
Low-level laser therapy(LLLT)has been clinically utilized for many indications in medicine requiring protection from el/issue death,stimulation of healing and repair of injuries,pain reduction,swelling and inflammatio...Low-level laser therapy(LLLT)has been clinically utilized for many indications in medicine requiring protection from el/issue death,stimulation of healing and repair of injuries,pain reduction,swelling and inflammation.Presently,the use of LLLT to treat stroke,traumnatic brain injury and cognitive dysfunction are attracting growing interest.Near infrared light is capable of penetrating into the cerebral cortex,allowing noninvasive treatments to be caried out with few treatment-related adverse events.Optimization of LLLT treatment flfect is a crucial isse of this field;however,only a few experimental tests on mice for wavelength selection have been reported.We addressed this ssue by low-ost,straightforward and quantitative comparisons on light dosage distribution within visible Chinese human head by Monte Carlo modeling of near infrared light propagation.Optimized selection in wavelength,beam type and size were given based on comparisons among frequently used setups(ie,wavelengths:660,810 and 980 nm;beam type:Gaussian and flat beamn;beam diameter:2,4 and 6 cm).This study provided an fficient way for guiding the optimization of LLLT setup and selection on wavelength,beam type and size for clinical brain LLLT.展开更多
文摘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.
文摘Influence produced by the heat effect at work of the laser instrument crystal of the semiconductor, the text designs a kind of temperature control system to the crystal of the laser instrument, using the thought and method of the classical control theory to analyze this temperature control system, and establishes mathematics model. According to mathematics model the text demonstrated the system at S field and time- area, and proposed optimizing basis to the total mark of proportion and differential parameter to con- troller PID, thus proposed a kind of temperature control scheme. And the thermostatically system is simulated by MATLAB.
基金supported,in part,by the Natural Science Foundation of China (Nos.81402043 and 81201141)the Clinical Capability Construction Project for Liaoning Provincial Hospitals (LNCCC-D50-2015+1 种基金LNCCC-C09-2015)the China postdoctoral science foundation Grant (2016T90233)
文摘Photothermal therapy(PTT)using near-infrared(NIR)light for tumor treatment has triggered extensive attentions because of its advantages of noninvasion and convenience.The current research on PTT usually uses lasers in the first NIR window(NIR-I;700–900 nm)as irradiation source.However,the second NIR window(NIR-II;1000–1700 nm)especially NIRIIa window(1300–1400 nm)is considered much more promising in diagnosis and treatment as its superiority in penetration depth and maximum permissible exposure over NIR-I window.Hereby,we propose the use of laser excitation at 1275 nm,which is approved by Food and Drug Administration for physical therapy,as an attractive technique for PTT to balance of tissue absorption and scattering with water absorption.Specifically,CuS-PEG nanoparticles with similar absorption values at 1275 and 808 nm,a conventional NIR-I window for PTT,were synthesized as PTT agents and a comparison platform,to explore the potential of 1275 and 808 nm lasers for PTT,especially in deep-tissue settings.The results showed that 1275 nm laser was practicable in PTT.It exhibited much more desirable outcomes in cell ablation in vitro and deep-tissue antitumor capabilities in vivo compared to that of 808 nm laser.NIR-IIa laser illumination is superior to NIR-I laser for deep-tissue PTT,and shows high potential to improve the PTT outcome.
基金funded by the Priority Academic Program Development of Jiangsu Higher Education Institution(Grant No.2014-37)the Jiangsu Provincial Health and Family Planning Commission(No.H201535)Orofacial Pain and TMD Research Unit,Institute of Stomatology,Affiliated Hospital of Stomatology,Nanjing Medical University,for their support
文摘Low-level laser therapy(LLLT) may have an effect on the pain associated with orthodontic treatment. The aim of this study was to evaluate the effect of LLLT on pain and somatosensory sensitization induced by orthodontic treatment. Forty individuals(12–33 years old; mean ± standard deviations: 20.8 ± 5.9 years) scheduled to receive orthodontic treatment were randomly divided into a laser group(LG) or a placebo group(PG)(1:1). The LG received LLLT(810-nm gallium-aluminium-arsenic diode laser in continuous mode with the power set at 400 mW, 2 J·cm–2) at 0 h, 2 h, 24 h, 4 d, and 7 d after treatment, and the PG received inactive treatment at the same time points. In both groups, the non-treated side served as a control. A numerical rating scale(NRS) of pain, pressure pain thresholds(PPTs), cold detection thresholds(CDTs), warmth detection thresholds(WDTs), cold pain thresholds(CPTs), and heat pain thresholds(HPTs) were tested on both sides at the gingiva and canine tooth and on the hand. The data were analysed by a repeated measures analysis of variance(ANOVA). The NRS pain scores were significantly lower in the LG group(P = 0.01). The CDTs,CPTs, WDTs, HPTs, and PPTs at the gingiva and the PPTs at the canine tooth were significantly less sensitive on the treatment side of the LG compared with that of the PG(P < 0.033). The parameters tested also showed significantly less sensitivity on the nontreatment side of the LG compared to that of the PG(P < 0.043). There were no differences between the groups for any quantitative sensory testing(QST) measures of the hand. The application of LLLT appears to reduce the pain and sensitivity of the tooth and gingiva associated with orthodontic treatment and may have contralateral effects within the trigeminal system but no generalized QST effects. Thus, the present study indicated a significant analgesia effect of LLLT application during orthodontic treatment.Further clinical applications are suggested.
文摘Traumatic brain injury is a major health concern worldwide with massive financial and social impact. Conventional treatments primarily focus on the prevention of further damage to the brain parenchyma, while failing to address the already existent symptoms. Previous clinical studies have shown that Low Level Laser Therapy (LLLT) can significantly reduce pain and induce temporary vasodilation in capillaries, which the authors hypothesize can be used to improve the quality of life in TBI patients by treating their current symptoms, which are predominately migraine-like headaches. This case report illustrates the use of LLLT in the treatment of a patient with a TBI and the great clinical success achieved in the reduction of pain, as measured by VAS—achievable within five treatments of 10 minutes in duration.
基金FAPESP(Sao Paulo Research Foundation),Grant/Award Number:2011/50686-0National Institute and Technology-Translational Medicine(INCT.TM)CNPq(National Council for Scientific and Technological Development)
文摘Background : Osteoporosis can make bone repair difficult. Low-level laser therapy( LLLT) has been shown to be a promising tool for bone neoformation. This study aimed to analyze the effect of LLLT on calvaria bone defects of ovariectomized rats using stereology. Methods : Fifty-four Wistar rats were subjected to bilateral ovariectomy, and bone defects were created in calvaria after 150 days. The animals were divided into nine groups(n = ?6 per group), and 24 hours after the bone defects were created they received three, six or 12 sessions of LLLT at 0, 20 or 30 J/cm 2, using a 780-nm low-intensity GaAlAs laser. One-way ANOVA followed by Tukey ' s post hoc test was used for data processing. A difference of P < 0.05 was considered statistically significant. The parameters evaluated were osteocyte density( Nv_(ost)), total osteocyte number( Nto ost), trabecular surface density( Sv_t), and trabecular surface area( Sa_t). Results : Data obtained showed that Nto ost, Sv t, and Sa t in group G2 rats were significantly different from G1(0 J/cm^2)( P < 0.05). Compared to group G4, G5 presented higher values for the parameters Sv t and Sa t, and G6 presented significantly higher values for almost all the analyzed parameters( Nv _(ost), Nto_(ost), Sv_t, and Sa t)( P < 0.05). Compared to group G7, G8 showed a higher value only for the parameter Sa t, and G9 showed significantly higher values for parameters Nv ost, Nto ost, Sv_t, and Sa_t. Conclusion : We conclude that LLLT stimulated bone neoformation and contributed to an increase in the total number of osteocytes, especially with a laser energy density of 30 J/cm^2 given for six and 12 sessions.
基金by Qiqihar Science and Technology Bureau Social Development General Instruction Project,No.SFGG-201965.
文摘BACKGROUND Routine preclinical interventions for patients with chronic periodontitis such as supragingival cleaning and subgingival curettage,establishing a balanced occlusal relationship,and irrigation with 3%hydrogen peroxide can relieve the symptoms to some extent.However,there is room for improvement in the overall effect.For example,Er:YAG lasers can quickly increase the temperature of the irradiated tissue,effectively eliminate dental plaque and calculus,reduce periodontal pockets,adjust periodontal microecology,and reduce the gingival sulcus.The content of factors in the liquid,and then achieve the purpose of treatment.AIM The aim was evaluate the effect of Er:YAG laser-assisted routine therapy on the periodontal status in chronic periodontitis.METHODS Between October 2018 and January 2020,106 patients with chronic periodontitis in our hospital were randomly assigned to either the study or control group,with 53 patients in each group.The control group underwent routine therapy,and the study group underwent Er:YAG laser therapy in addition to routine therapy.We evaluated the treatment outcome in both groups.Periodontal status was determined by clinical attachment loss(CAL),gingival index(GI),periodontal probing depth(PD),dental plaque index(PLI),and sulcular bleeding index(SBI),inflammatory factors in the gingival crevicular fluid,tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),IL-8],and colony forming units(CFUs).RESULTS Total effectiveness in the study group(94.34%)was higher than that in the control group(79.25%,P<0.05).The clinical parameters in the study group(PD,5.28±1.08 mm;CAL,4.81±0.79 mm;SBI,3.37±0.59;GI,1.38±0.40;PLI,2.05±0.65)were not significantly different from those in the control group(PD,5.51±1.14 mm;CAL,5.09±0.83 mm;SBI,3.51±0.62;GI,(1.41±0.37;PLI,1.98±0.70)before treatment(P>0.05).However,after treatment,the parameters in the study group(PD,2.97±0.38 mm;CAL,2.71±0.64 mm;SBI,2.07±0.32;GI,0.51±0.11;PLI,1.29±0.34)were lower than those in the control group(PD,3.71±0.42 mm;CAL,3.60±0.71 mm;SBI,2.80±0.44;GI,0.78±0.23;PLI,1.70±0.51)(P<0.05).Differences in crevicular TNF-α,IL-6,and IL-8 levels in the study(TNF-α,7.82±3.43 ng/mL;IL-6,11.67±2.59 ng/mL;IL-8,12.12±3.19 pg/mL)and control groups(TNF-α,9.06±3.89 ng/ml,IL-6,12.13±2.97 ng/mL,IL-8,10.99±3.30 pg/mL)before therapy(P>0.05)were not significant.Following treatment,the parameters were significantly lower in the study group(TNF-α,2.04±0.89 ng/mL;IL-6,4.60±1.26 ng/mL;IL-8,3.15±1.08 pg/mL)than in the control group(TNF-α,3.11±1.07 ng/mL;IL-6,6.25±1.41 ng/mL;IL-8,4.64±1.23 pg/mL,P<0.05).The difference in the CFU of the study group[(367.91±74.32)×104/mL and control group(371.09±80.25)×104/mL]before therapy was not significant(P>0.05).The CFU decreased in both groups following therapy,however,the CFU values were lower in the study group[(36.09±15.26)×104/mL]than in the control group[(45.89±18.08)×104/mL](P<0.05).CONCLUSION Combining Er:YAG lasers with routine measures significantly improved the overall periodontal therapy outcomes by improving periodontal status and reducing oral levels of inflammatory factors and CFUs.
文摘AIM: To validate the protocol described here to be used in future clinical trials related to the effect of laser therapy on dental pulp. METHODS: Histologically treated samples from eight human healthy premolar teeth obtained from the middle root level were distributed in four groups: group 1(G1) absolute control; group 2(G2) only laser irradiation; group 3(G3) exposed only to orthodontics; and group 4(G4) treated with orthodontics and laser. Laser treatment was performed at 830 nm wavelength, 100 mW(energy 80 J/cm2, 2.2 J), for 22 s in the vestibular surface and 22 s in the palatal surface, 1 mm away from the dental root mucosa. Three staining methods were performed: hematoxylin-eosin(HE), Masson's Trichrome method and Gomori's method.RESULTS: The pulp histology parameters were evaluated and the results classified in to 3 parts: an inflammatory response, soft tissue response(dental pulp) and hard tissue response(dentin and predentin). There was no inflammation(chronic or acute) in any of the evaluated groups. The zones of pulp necrosis were found in one premolar of G3 and in one of G4; in groups G2 and G4 there was higher angiogenesis than in the other two groups. G4 group presented the highest level of vascularization. A reduced nerve density was observed in G3. A G2 specimen showed increased nerve density. A higher rate of calcification was observed in G1 compared to G2. Denticles, either real or false, were observed in G1, G2 and G3. Sclerosis of dentin and focal dentin loss was observed among all the groups. Secondary dentin was present in one sample in G1 and G2. A necrosis zone was found in one sample of G3 and G4. No differences between groups were observed in the odontoblast irregularity layer but the layer was wider in the group treated with laser only. A notable difference was detected in reduction of the cell-free layer between the groups G1 and G4. The findings in pulp tissue favor its adaptative response against dental movement induced by orthodontics. No definitive conclusions may be derived as this is a pilot study. CONCLUSION: The protocol described here was shown to be an effective method to evaluate changes in dental pulp submitted to low level laser in teeth under orthodontic movement.
文摘At present, the only FDA approved treatment for ischemic strokes is intravenous administration of tissue plasminogen activator within 4.5 hours of stroke onset. Owing to this brief window only a small percentage of patients receive tissue plasminogen activator. Transcranial laser therapy has been shown to be effective in animal models of acute ischemic stroke, resulting in significant improvement in neurological score and function. NEST-1 and NEST-2 clinical trials in human patients have demonstrated the safety and positive trends in efficacy of transcranial laser therapy for the treatment of ischemic stroke when initiated close to the time of stroke onset. Combining intravenous tissue plasminogen activator treatment with transcranial laser therapy may provide better functional outcomes. Statins given within 4 weeks of stroke onset improve stroke outcomes at 90 days compared to patients not given statins, and giving statins following transcranial laser therapy may provide an effective treatment for patients not able to be given tissue plasminogen activator due to time constraints.
基金supported by the National Key R&D Program of China(No.2017YFB0403802)the Technology Cooperation High-tech Industriali-zation Program of Jilin Province of China and the Chinese Academy of Sciences(No.2018SYHZ0023)+2 种基金the Key Technology R&D Program of Jilin Prov-ince of China(No.20180201047YY)the Scientific Research Program of Shanghai Science and Tech-nology Commission(No.18441904300)the Technology Cooperation High-tech Industrializa-tion Program of Jilin Province of China and the Chinese Academy of Sciences(No.2019SYHZ0032)
文摘The majority of existing high-power laser therapeutic instruments employ a single wavelength for a single target;thus,they do not meet the requirements for clinical treatment.Therefore,this study designs an optical system for a dual-wavelength high-power laser therapeutic device with a variable spot size.The waist of the short arm of the optical cavity and the G1G2 parameter(G-parameter equivalent cavity method)is calculated using MATLAB software,the spot size and divergence angle on the lens are calculated using an ABCD matrix,and the distance between the treatment spot at different spot sizes and the transformation lens is calculated in order to design the treatment handpiece.Experiments are conducted to analyze the stability at an output power of 532 nm before beam combination and the power loss after beam combination.The results show that the output power stability of the 532-nm beam varies by less than 2%over 150 min,and the loss of both wavelengths is less than 20%,which meets the clinical requirements of the system.The safety performance can meet the requirements of national general standards for medical electrical safety.The proposed dual-wavelength laser therapy instrument has both visible wave and near-infrared wave characteristics;thus,it can accurately target both superficial vessels and vessels with a larger diameter and deeper position.This therapeutic device has the advantages of simple operation,stable and reliable laser output,high security and strong anti-interference ability,and meets the comprehensive clinical treat-ment demands of vascular diseases.
文摘Aggressive cytoreduction can prolong survival in patients with unresectable liver metastases(LM)from neuroendocrine neoplasms(NEN),and minimally invasive,liver-directed therapies are gaining increasing interest.Catheter-based treatments are used in disseminated disease,whereas ablation techniques are usually indicated when the number of LM is limited.Although radiofrequency ablation(RFA)is by far the most used ablative technique,the goal of this opinion review is to explore the potential role of laser ablation(LA)in the treatment of LM from NEN.LA uses thinner needles than RFA,and this is an advantage when the tumors are in at-risk locations.Moreover,the multi-fiber technique enables the use of one to four laser fibers at once,and each fiber provides an almost spherical thermal lesion of 12-15 mm in diameter.Such a characteristic enables to tailor the size of each thermal lesion to the size of each tumor,sparing the liver parenchyma more than any other liver-directed therapy,and allowing for repeated treatments with low risk of liver failure.A recent retrospective study reporting the largest series of LM treated with LA documents both safety and effectiveness of LA,that can play a useful role in the multimodality approach to LM from NEN.
文摘Acute renal failure has a 50% - 80% mortality rate. Currently, treatment options for this life-threatening disease are limited. Low-level laser therapy (LLLT) has been found to modulate biological activity. The aim of the present study was to investigate the possible beneficial effects of laser application to stem cells in the bone marrow, on the kidneys of rats that had undergone ischemia-reperfusion injury (IRI). IRI was induced by occlusion of the renal artery to 3- and 7-month-old rats for 15 or 30 minutes. In an additional experiment IRI was applied to both kidneys for 20 min each in 2-3-month-old rats. Rats were then divided randomly into two groups of control and laser-treated. Laser therapy (Ga-Al-As 810 nm, 200 mW output for 2 min) was applied to the bone marrow 1 and 7 days post-IRI to the kidneys, and rats were sacrificed 2 weeks later. Histomorphometry and immunohistochemistry were performed on kidney sections and blood markers for kidney function. Quantitative histomorphometric analysis revealed a reduction in dilatation of the renal tubules, restored structural integrity of the renal tubules, and reduced necrosis in the laser-treated rats as compared to the control, non-laser-irradiated group. C-kit positive cell density in kidneys post-IRI and laser-treatment was significantly (p = 0.015) 3.2-fold higher compared to the control group. Creatinine and blood urea nitrogen content were significantly lower in the laser-treated rats as compared to control. It is concluded that LLLT application to the bone marrow (BM) causes a significant increase in the density of mesenchymal stem cells in the kidneys post-IRI, probably by induction of stem cells in the BM, which subsequently migrate to the IRI kidney, significantly reducing the pathological features of the kidney and increasing kidney function post IRI.
基金Supported by the Basic Discipline Layout Foundation of the Shenzhen Science and Innovation Commission(No.JCYJ20170817112542555)。
文摘AIM:To compare the efficacy and safety between laser therapy and anti-vascular endothelial growth factor(VEGF)agents intravitreal injection monotherapy in type-1 retinopathy of prematurity(ROP)and aggressive posterior retinopathy of prematurity(APROP).METHODS:A systematic literature search was performed in PubMed,Cochrane Library,and Embase for original comparable studies.We included studies that compare laser therapy and intravitreal injections of anti-VEGF agents monotherapy in ROP regardless of languages and publication types.RESULTS:Complication incidence was significantly higher in laser therapy group(OR:0.38;95%CI:0.19-0.75;P=0.005).Spherical equivalent(SE)was higher in laser therapy[weighted mean difference(WMD):2.40,95%CI:0.88-3.93;P=0.002].The time between treatment and retreatment was longer in laser therapy group(WMD:8.45,95%CI:5.35-11.55;P<0.00001).Recurrence incidence(OR:0.97;95%CI:0.45-2.09;P=0.93)and retreatment incidence(OR:1.24;95%CI:0.56-2.73;P=0.59)were similar in two approaches.Subgroup analysis between type-1 ROP and APROP was not significant except SE reported in the included studies(P<0.0001).CONCLUSION:This Meta-analysis outcome indicates anti-VEGF agents are as effective as laser treatment,and safer than laser in type-1 ROP and APROP.The degree of myopia in APROP is higher than type-1 ROP.More randomized controlled trials in large sample size should be conducted in the future.
文摘Since carbon dioxide laser is excellent for incision, hemostasis, coagulation, and vaporization of soft tissues, it has been widely applied in clinical treatments as the laser knife. In these days, flexible thin hollow optical fibers transmitting mid-infrared light have been developed, and the application of carbon dioxide laser to endoscopic therapy has become possible. However, it is expected that the irradiation effect is influenced by the change in the laser power at the tip of the hollow optical fiber due to the change in the transmittance by the bending loss. The purpose of this research is to quantitatively evaluate the change in the output power and therapeutic effect by bending the hollow optical fiber in a gastrointestinal endoscope. The change in the transmittance of the hollow optical fiber due to the insertion of the fiber into the endoscope and bending of the head of the endoscope was measured. Then, the relationship between the irradiated laser power and the incision depth for a porcine stomach was investigated. As the results, the most significant decrease in the transmittance of the hollow optical fiber was caused by the insertion of the fiber into the instrument channel of the endoscope, and bending of the head of the endoscope with the angle of 90° decreased the output laser power and incision depth by 10% and 25%, respectively. Therefore, it was confirmed that the bending loss of the hollow optical fiber due to the bending of the head of the endoscope had no significant influence on the endoscopic therapy using the carbon dioxide laser.
文摘Photothermal therapy (PTT), which utilizes light radiation to create localized heating effect in the targeted areas, is a promising solution for highly specific yet minimally invasive cancer therapy. PTT uses photothermal agents, which are usually nanoparticles that absorb strongly in the near-infrared optical window where minimal tissue absorption occurs. Photothermal agents are also highly functionalized to target at specific tumor sites. Gold nanostar is an ideal candidate for photothermal agents, because it not only has a Surface Plasmon Resonance in the near-infrared, but also can be easily produced and purified, and is extremely versatile in the drug delivery process. In order to achieve maximum amount of localized heating, pulse lasers are usually used in laser ablation processes like photothermal therapy. However, intensive laser radiation can cause damage to regular tissues as well the nanostructures themselves. Therefore, identifying the optimal pulse duration to effectively generate localized heating in the tumorous tissues while keeping the normal tissues and the nanostructures intact is important to achieving optimal photo-therapeutic results. This manuscript provides a numerical calculation method with Comsol Multiphysics to optimize the pulse condition of the gold nanostars under photothermal therapy settings. Based on results, gold nanostar displays significant temperature heterogeneity under femtosecond and picosecond laser radiation, while nanosecond laser only induces rather uniform heating effects across the entire gold nanostar particle. This finding indicates that femtosecond laser, which is the most common type of laser used for ablation, is likely to melt the tip of the gold nanostar before the nanostar body reaches a reasonably high temperature. Picosecond and nanosecond lasers are much less likely to induce such dramatic morphology change. This study offers important insight into finding the optimal condition for photothermal therapy with maximal efficacy and minimal damage.
文摘The use of laser therapy is one of the most effective tools in the prevention and treatment of skin ulcers. It is an effective treatment choice because it potentiates the trophic regenerative, anti inflammatory, and painkiller effects. This study aimed to assess the effectiveness of low level laser therapy in treating induced cutaneous ulcers in rats. An experimental study using 12 female Wistar rats (Rattus novergicus), weighing between 150 and 250 g, from the room of animal husbandry at the Center of Health Sciences of UNIFOR. Rats underwent surgery to induce cutaneous ulcer. Subsequently, the animals were divided into two randomized groups: 1) Control group;and 2) Experimental group. They received nine applications of AlGaInP laser treatment (power of 30 mW) with an intensity of 4 J/cm2, using the scan method, for 15 seconds over the entire ulcer. The cicatrization process was evaluated from the 1st to 19th postoperative (PO) day, but on alternate days. The results showed that animals treated with laser had less area of cutaneous wound than the control group from the 7th until the 17th postoperative day, highlighting the 7th and the 9th PO with a significant reduction in wound area of 28.8% (p = 0.00) and 23,5% (p = 0.01), respectively. Treatment with the AlGaInP laser was effective in the repair of cutaneous wound when compared to the control group—particularly on the 7th postoperative day.
文摘Hyper thermal therapy using lasers is emerging as a new promising route for the cancer treatment. The tumor can be directly heated by the radiation or indirectly using gold nano particles based on plasmon resonance phenolmenon. These two possibilities are explored here by solving the space and time dependent bio-heat equation under different conditions. The knowledge of temperature profiles in the tumor region helps to bypass the painful placement of sensors for monitoring tumor’s heating by the laser. Important properties which could be useful for developing an efficient tumor therapy are introduced for the first time. It is found that the effects of metabolism consist essentially in a redefinition of the blood temperature which increases proportional to the heat of metabolism. Blood perfusion in a given tissue leads to a new characteristic length of order one or two centimeters and a blood convection parameter typically of order 30 W·m-1·K-1. Effects of these parameters are scrutinized within the resolution of the bio-heat equation under a variety of conditions. In general, space modulations of the temperature throughout biological tissues are weak but front kinetics are quite fast. Specific examples show the way to monitor the temperature rise taking into account the tumor’s nature and size.
文摘Objective:To evaluate the effectiveness of endovenous laser therapy and conventional thera- py on the varicose of great saphenous vein.Methods:Thirty-two patients received endovenous laser thera- py and 32 patients were operated by conventional therapy(high ligation and stripping).The observation results of great saphenous vein(GSV)were recorded by clinical evaluation and duplex ultrasound examina- tion.And the operating time,intraoperative blood loss,time to become moveable,duration of hospitaliza- tion and degree of feeling pain were compared between the two groups.Results:Compared with conven- tional therapy,laser therapy had good curative effect with less complications and no scars and no pains. There were significant differences between the two groups(P<0.01).Conclusion:Laser therapy for varicose of great saphenous vein is better than the conventional therapy.It deserves to be widely used in clinical treatment.
文摘In this study, we investigated the hypothesis that photobiostimulation by low-energy laser therapy (LLLT) applied to the bone marrow (BM) of myocardial infarcted rats may attenuate the scarring processes that follow myocardial infarction (MI). Wistar rats underwent experimental MI. LLLT (Ga-Al-As diode laser) was applied to the BM of the exposed tibia at different time intervals post-MI (4 hrs, 48 hrs and 5 days). Sham-operated infarcted rats served as control. Infarct size was significantly reduced (55%) in the laser-treated rats as compared to the control non-treated rats, at 2 weeks post-MI. A significant 3-fold increase was observed in the density of desmin immunopositive stained cells 14 days post-MI in the infarcted area of the laser-treated rats as compared to the non-laser-treated controls. The electron microscopy from the control infarcted rat hearts revealed a typical interphase area between the intact myocardium and the infarcted area, with conspicuous fibroblasts with collagen deposition dispersed among them. In rats that were laser treated (to BM), the interphase zone demonstrated cells with different intracellular structures. There was also a significant increase in the percentage of c-kit positive cells and macrophages in the circulating blood of the laser treated rats as compared to control non treated ones. In the majority of the cells clusters of myofibrils anchored to well-developed Z-lines and structures resembling the morphological characteristics of mature intact cardiomyocytes were evident. In conclusion, LLLT to the BM of rats post-MI induces cardiogenesis mainly at the borders of the infarcted area in the heart.
基金supported by the Research Start Fund (Grant No.Y02002010)the Central University Basic Scienti¯c Research Project Business Expenses (Grant No.ZYGX2012J114)the National Natural Science Foundation of China (Grant No.61308114).
文摘Low-level laser therapy(LLLT)has been clinically utilized for many indications in medicine requiring protection from el/issue death,stimulation of healing and repair of injuries,pain reduction,swelling and inflammation.Presently,the use of LLLT to treat stroke,traumnatic brain injury and cognitive dysfunction are attracting growing interest.Near infrared light is capable of penetrating into the cerebral cortex,allowing noninvasive treatments to be caried out with few treatment-related adverse events.Optimization of LLLT treatment flfect is a crucial isse of this field;however,only a few experimental tests on mice for wavelength selection have been reported.We addressed this ssue by low-ost,straightforward and quantitative comparisons on light dosage distribution within visible Chinese human head by Monte Carlo modeling of near infrared light propagation.Optimized selection in wavelength,beam type and size were given based on comparisons among frequently used setups(ie,wavelengths:660,810 and 980 nm;beam type:Gaussian and flat beamn;beam diameter:2,4 and 6 cm).This study provided an fficient way for guiding the optimization of LLLT setup and selection on wavelength,beam type and size for clinical brain LLLT.