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Candidiasis is a common fungal infection, with Candida tropicalis infections being relatively rare. These infections develop into skin fungal infections under conditions such as broad-spectrum antibiotic use, diabetes, and immunosuppression. Traditionally, antifungal drugs have been the primary treatment; however, issues like hepatotoxicity and the need for long-term use persist. Consequently, new treatment approaches are essential. Most previous reports have focused on Candida albicans, with fewer addressing Candida tropicalis. This study reports a case where a patient with a skin Candida tropicalis infection was treated with a combination of surgery and ALA photodynamic therapy(635 nm, 120 J/cm2, 177 mW/cm2). After just one session of this combined treatment, the patient achieved significant clinical remission. Therefore, the combination of surgery and ALA-PDT may offer a safe and effective treatment option.
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We propose what we believe to be a novel nonlinear optical limiting (NOL) method with a low limiting threshold based on a light intensity-controlled polarizability inversion suspension (PIS). This suspension has negative polarizability under weak light, allowing stable propagation of weak light with a low loss. Nevertheless, the suspension reverses into positive polarizability due to the optical Kerr effect under strong light, resulting in enhanced scattering that rapidly attenuates the intense light. In a proof-of-concept experiment, PS (polystyrene)-CS2-CCl4 suspension is used as the example suspension. We experimentally verify the NOL performance of several samples. Among them, 4â g/L PS-CS2-CCl4 suspension with a volume ratio of 0.15 has the best optical limiting effect, with a high limiting capacity coefficient of 0.48 and a very low limiting threshold of 14.80â kW/cm2, which is an order magnitude lower than that of most common NOL materials. Therefore, the proposed method provides a new promising approach to achieve NOL of continuous wave laser with a low limiting threshold.
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The development of solid-state nonlinear optical limiting (NOL) materials is crucial for advancing the practicality in the field of optical limiting. In this paper, we innovatively prepare a new solid NOL material which is spiral carbon nanotubes doped epoxy resin (SCNTs-doped ER, SER) with a simple physical mixing method, and achieve an excellent nonlinear optical limiting performance. We experimentally measured optical limiting of SER with different SCNTs concentrations (0.14, 0.28, and 0.43â mg/mL) and obtained the nonlinear absorption coefficient, nonlinear refractive index, and third-order nonlinear susceptibility at the wavelength 1064â nm. Z-scan experiment results show that the SER exhibits a large nonlinear absorption coefficient (5.07 ± 0.38) × 10-9 m/W. We also measure the transmittance of the SER to evaluate its nonlinear optical limiting performance. For the SER with 0.43â mg/mL concentration, the linear transmittance and minimum transmittance with NOL effects at 1064â nm are 54.8% and 26.2%, respectively. In addition, the SER also has prominent features such as a high damage threshold and easy fabrication, indicating that the SER is a promising solid material for nonlinear optical limiting.
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To realize the high sensitivity polarization sensitive optical coherence tomography (PS-OCT) imaging, a fiber-based full-range depth-encoded swept source PS-OCT (SS-PS-OCT) method is proposed. The two OCT images corresponding to the orthogonal polarized input light are located on the high sensitivity imaging region of the opposite sides relative to the zero optical path difference position. The full-range OCT images can be obtained by implementing the spatial phase modulation in the reference arm. The detection sensitivity of the system was measured experimentally to be 67â dB when the imaging depth approaching to 2 mm. The imaging of the biological tissue verifies that the proposed full-range depth-encoded SS-PS-OCT system has the higher detection sensitivity compared with the conventional depth encoded SS-PS-OCT system. Finally, we demonstrated the full-range high sensitivity phase retardation image of the bovine tendon and skin of human fingertip. The fiber-based full-range depth-encoded SS-PS-OCT method can realize the high sensitivity birefringence imaging in the medical diagnosis scenes with the requirements for long imaging range and high detection sensitivity.
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BACKGROUND: Dermatofibrosarcoma Protuberans (DFSP) is a rare, low-grade malignant tumor of the dermis with a high recurrence rate post-surgery. Current treatments, including surgery, radiotherapy, and targeted therapy, have limitations. Photodynamic therapy (PDT) with 5-aminolevulinic acid (5-ALA) is a promising non-invasive approach, but its efficacy in DFSP treatment remains underexplored. METHODS: This study aimed to evaluate the anti-tumor efficacy of 5-ALA PDT using an in vitro model derived from a recurrent DFSP patient. The cells were treated with varying concentrations of 5-ALA and exposed to red light, followed by assessments of cell viability, proliferation, apoptosis, migration, invasion, angiogenesis, and expression of DFSP-related genes and proteins. RESULTS: 5-ALA PDT significantly reduced DFSP cell viability in a dose-dependent manner and induced apoptosis. It also effectively inhibited cell proliferation, migration, and invasion, as well as suppressed angiogenic activity in conditioned media. Furthermore, 5-ALA PDT downregulated the expression of COL1A1 and PDGFRB, key genes in DFSP pathogenesis. CONCLUSIONS: The findings provide the first evidence of 5-ALA PDT's in vitro anti-tumor efficacy against DFSP, suggesting its potential as a novel therapeutic approach for DFSP. Further studies are warranted to explore the clinical utility of 5-ALA PDT in preventing DFSP recurrence.
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Ácido Aminolevulínico , Proliferación Celular , Supervivencia Celular , Dermatofibrosarcoma , Fotoquimioterapia , Fármacos Fotosensibilizantes , Ácido Aminolevulínico/farmacología , Ácido Aminolevulínico/uso terapéutico , Fotoquimioterapia/métodos , Humanos , Dermatofibrosarcoma/tratamiento farmacológico , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/uso terapéutico , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Apoptosis/efectos de los fármacos , Recurrencia Local de Neoplasia , Neoplasias Cutáneas/tratamiento farmacológico , Neoplasias Cutáneas/patología , Relación Dosis-Respuesta a Droga , Movimiento Celular/efectos de los fármacosRESUMEN
Lissajous micro scanners are very attractive in compact laser scanning applications for biomedical endoscopic imaging, such as confocal microscopy, endomicroscopy or optical coherence tomography. The scanning frequencies have a very important effect on the quality of the resulting Lissajous scanning imaging. In this paper, we propose a frequency selection rule for high definition and high frame-rate (HDHF) Lissajous scanning imaging, by deriving the relationship among the scanning field of view (FOV), actuation frequencies and pixel size based on the characteristics of the scanning trajectory. The minimum sampling rate based on the proposed frequency selection rule is further discussed. We report a lead zirconate titanate piezoelectric ceramic (PZT) based Lissajous fiber scanner to achieve HDHF Lissajous scanning imaging. Based on the frequency selection rule, different frequency combinations are calculated, under which the Lissajous fiber scanner can work at the frame rate (FR) of 10â Hz, 20â Hz, 40â Hz and 52â Hz. The trajectory evolution of the Lissajous scanning at the frame rate of 10â Hz has been obtained to verify the applicability of the proposed rule. The measured resolution of the scanner is 50.8 lp/mm at the unit optical magnification, and the measured FOV at the FR of 10â Hz and 40â Hz are 1.620 mm ×1.095 mm and 0.405 mm ×0.27 mm, respectively. HDHF Lissajous scanning images of the customized spatial varying binary pattern are obtained and reconstructed at the FR of 10â Hz and 40â Hz, demonstrating the practicability of the frequency selection rule.
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BACKGROUND: Keloids are aggressive fibroproliferative disorders that cause aesthetic and functional damage. Photodynamic therapy (PDT) has shown promise as a novel treatment for keloids. However, the limited penetration of 5-aminolevulinic acid (ALA) and unsatisfactory outcomes in dense scars hinder its effectiveness as a monotherapy. The objective of this study is to assess the efficacy and safety of fractional CO2 laser followed by 5-ALA PDT for keloids. METHODS: A total of 12 patients with keloid were included in our study. Each lesion was pretreated by fractional CO2 laser with 26-28 W to create microthermal zones. After topical application of 5-ALA solution, an irradiation of 635 nm red light with 120 J/cm2 was performed. The treatment was repeated at least every 2 weeks. Efficacy and safety were evaluated using the Vancouver Scar Scale (VSS), the Visual Analogue Scale (VAS) for keloid-related symptoms and documentation of postoperative complications. Statistical analysis was performed to compare VSS and keloid-related symptom VAS scores of the baseline and final treatment sessions. RESULTS: The final treatment resulted in a statistically significant decrease in all parameters of VSS and VAS for pruritus and pain compared to the baseline. Except for postoperative hyperpigmentation, no infections, scar aggravation, or recurrence were observed during at least 6 months of follow-up. Overall, patients expressed a high level of satisfaction with the treatment outcome. CONCLUSIONS: Fractional CO2 laser followed by 5-ALA PDT is a promising method for treating keloids. However, its synergetic effects need to be validated through clinical trials involving larger patient cohorts.
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Queloide , Láseres de Gas , Fotoquimioterapia , Humanos , Queloide/tratamiento farmacológico , Ácido Aminolevulínico/uso terapéutico , Dióxido de Carbono , Láseres de Gas/uso terapéutico , Fármacos Fotosensibilizantes/uso terapéutico , Fotoquimioterapia/métodosRESUMEN
BACKGROUND: Previously, albendazole (ABZ) has been reported as an anti-parasitic drug rather than anti-tumor drug. Our study aim to investigate whether ABZ also has a potential anti-tumor effect by shaping the tumor immune microenvironment and interrogate whether ABZ could synergize with the PD-L1 blockade. METHODS: C57BL/6 mice (C57) were intravenously injected with B16F10-luciferase (B16-luc) cells to establish a lung metastatic melanoma model and subcutaneously inoculated with B16-luc cells to establish a subcutaneous tumor model. The tumor volume and tumor metastasis loci of the mice were measured by a vernier caliper and in vivo imaging. RNA sequencing was performed to analyze the different genes and pathways of immune cells in the tumors. Flow cytometry and immunofluorescence were used to analyze the different subsets of tumor-infiltrating immune cells. RESULTS: The results suggested that ABZ significantly inhibited lung melanoma metastasis with decreased fluorescence intensity and nodule score and mediated the regression of subcutaneous melanoma in mice with decreased tumor volume. Moreover, RNA sequencing results showed that ABZ regulated the gene expression levels and pathways of immune cells in the tumor microenvironment (TME). Meanwhile, flow cytometry and immunofluorescence showed that the number and percentage of CD8+ T cells, CD4+ T cells, and TH1 cells were enhanced in tumors after ABZ treatment. Furthermore, the combination of ABZ and anti-PD-L1 treatment significantly potentiated anti-tumor efficacy in both lung metastasis and subcutaneous melanoma models and mediated an increase in the percentage of CD8+ T cells, CD4+ T cells, and TH1 cells as compared to the control group. CONCLUSION: ABZ inhibits melanoma growth and metastasis. Moreover, ABZ synergized with PD-L1 blockade mediates tumor regression.
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Neoplasias Pulmonares , Melanoma , Ratones , Animales , Linfocitos T CD8-positivos , Albendazol/farmacología , Antígeno B7-H1 , Ratones Endogámicos C57BL , Inmunoterapia/métodos , Melanoma/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Microambiente Tumoral , Línea Celular TumoralRESUMEN
Diet High in salt content have been associated with cardiovascular disease and chronic inflammation. We recently demonstrated that transient receptor potential canonical 3 (TRPC3) channels regulate myofibroblast transdifferentiation in hypertrophic scars. Here, we examined how high salt activation of TRPC3 participates in hypertrophic scarring during wound healing. In vitro, we confirmed that high salt increased the TRPC3 protein expression and the marker of myofibroblast alpha smooth muscle actin (α-SMA) in wild-type mice (WT) primary cultured dermal fibroblasts but not Trpc3-/- mice. Activation of TRPC3 by high salt elevated cytosolic Ca2+ influx and mitochondrial Ca2+ uptake in dermal fibroblasts in a TRPC3-dependent manner. High salt activation of TRPC3 enhanced mitochondrial respiratory dysfunction and excessive ROS production by inhibiting pyruvate dehydrogenase action, that activated ROS-triggered Ca2+ influx and the Rho kinase/MLC pathway in WT mice but not Trpc3-/- mice. In vivo, a persistent high-salt diet promoted myofibroblast transdifferentiation and collagen deposition in a TRPC3-dependent manner. Therefore, this study demonstrates that high salt enhances myofibroblast transdifferentiation and promotes hypertrophic scar formation through enhanced mitochondrial Ca2+ homeostasis, which activates the ROS-mediated pMLC/pMYPT1 pathway. TRPC3 deficiency antagonizes high salt diet-induced hypertrophic scarring. TRPC3 may be a novel target for hypertrophic scarring during wound healing.
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This work presents a new, to the best of our knowledge, porous graphene dispersion in ethanol that can achieve a good nonlinear optical limiting (NOL) effect at the wavelength of 1064 nm. Using the Z-scan system, the nonlinear absorption coefficient of the porous graphene dispersion with a concentration of 0.01 mg/mL was measured as 9.69×10-9 c m/W. The NOL of the porous graphene dispersions in ethanol under three different concentrations (0.01, 0.02, and 0.03 mg/mL) were measured. Among them, the 1-cm-thick porous graphene dispersion with a concentration of 0.01 mg/mL has the best optical limiting effect, in which the linear transmittance is 76.7%, and the lowest transmittance is 24.9%. By using the pump-probe technique, we detected the formation and annihilation times of the scatter when the suspension interacts with the pump light. The analysis shows that the NOL mechanisms of the novel porous graphene dispersion are mainly nonlinear scattering and nonlinear absorption.
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Keloids display many cancerous properties, including uncontrolled and invasive growth, high rates of recurrence as well as similar bioenergetics. 5-aminolevulinic acid-based photodynamic therapy (5-ALA-PDT) is an effective treatment that performs cytotoxic effects by producing reactive oxygen species (ROS), which is linked to lipid peroxidation and ferroptosis. Herein, we explored underlying mechanisms of 5-ALA-PDT against keloids. We identified that 5-ALA-PDT led to elevated levels of ROS and lipid peroxidation in keloid fibroblasts, accompanied by downregulation of xCT and GPX4, which are associated with anti-oxidation effects and ferroptosis inhibition. These results may indicate that 5-ALA-PDT treatment increases ROS while inhibiting xCT and GPX4, thus promoting lipid peroxidation to induce ferroptosis in keloid fibroblasts.
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Ferroptosis , Queloide , Fotoquimioterapia , Humanos , Ácido Aminolevulínico/farmacología , Ácido Aminolevulínico/uso terapéutico , Queloide/tratamiento farmacológico , Especies Reactivas de Oxígeno/metabolismo , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/uso terapéutico , Fotoquimioterapia/métodos , Regulación hacia Abajo , FibroblastosRESUMEN
We showed the local polarization properties extraction method for the single incident state, all-single-mode-fiber-based spectral domain polarization-sensitive optical coherence tomography (SD-PS-OCT) system that uses the single linear-in-wavenumber spectral camera. Polarization controllers are used in the single-mode-fiber-based SD-PS-OCT system to provide a compact structure with polarization state stability. The local polarization properties of the birefringent sample are extracted from the cumulative polarization properties iteratively. The reconstructed polarization images demonstrate the local polarization properties extraction ability of the system.
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Background and Objective: Acne vulgaris is a common skin disease around the world which affects the appearance of patients, as well as their physical and mental health. Cutibacterium acnes plays a vital role in the occurrence and development of acne vulgaris. Pattern recognition receptors (PRRs) are the first line of defense against external pathogens. The nucleotide oligomerization domain (NOD)-like receptor family pyrin containing 3 (NLRP3) inflammasome has recently been shown to contribute to the pathogenesis of acne vulgaris. The purpose of this review is to clarify the underlying mechanisms of NLRP3 inflammasome in the pathogenesis of acne vulgaris, and its potential as a therapeutic target for the condition. Methods: The PubMed database was searched for relevant articles published in English between January 2003 to December 2021 using keywords "acne vulgaris", "NLRP3 inflammasome", and "Cutibacterium acnes". The reference lists of retrieved articles were also reviewed to identify relevant articles. Key Content and Findings: Cutibacterium acnes infection can lead to a series of inflammatory reactions and the production of inflammatory factors such as interleukin (IL)-1ß. In vitro and in vivo studies demonstrated that the NLRP3 inflammasome plays essential roles in acne vulgaris. Further, innate immunity and adaptive immunity pervade the entire pathogenesis of acne vulgaris. Conclusions: The NLRP3 inflammasome may be a potential therapeutic target for acne vulgaris. Future studies are needed to investigate the potential therapeutic effects of NLRP3 inhibitors on acne vulgaris.
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Cancer is a major threat to human health because of its high mortality, easy recurrence, strong invasion, and metastasis. Photodynamic therapy (PDT) is a promising minimally invasive treatment for tumor. Compared with traditional treatment methods, PDT is less invasive and does not easily damage normal tissues. Most of the effects of this treatment are due to the direct effects of singlet oxygen together with reactive oxygen species. PDT can provide the source of active oxygen for the Fenton reaction, which enhances ferroptosis and also improves the efficacy of PDT in antitumor therapy. Additionally, in contrast to chemotherapy and radiotherapy, PDT has the effect of stimulating the immune response, which can effectively induce immunogenic cell death (ICD) and stimulate immunity. PDT is an ideal minimally invasive treatment method for tumors. In this paper, according to the characteristics of anti-tumor immunity of PDT, some tumor treatment strategies of PDT combined with anti-tumor immunotherapy are reviewed.
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Many researches have reported the air pollution impacts, either long term or short term, on inflammatory skin diseases, but there are few studies on the relation between PM2.5 and acne vulgaris. To determine the correlation between short-term PM2.5 exposure and acne outpatient visits, data for 120,842 acne vulgaris outpatient visits between December 2013 and December 2019 were obtained from three large hospitals in Chongqing, China. Both single-pollutant models and two-pollutant models were established to explore the relationship between PM2.5 exposure and acne outpatient visits. The stratified analyses were conducted through two-sample z-tests to investigate the possible gender (male or female) and age (< 25 years or ≥ 25 years) differences in PM2.5 effects. The results demonstrated positive correlations between PM2.5 concentrations and acne outpatient visits. A 10 µg/m3 increase in PM2.5 concentration was associated with a 1.71% (95% CI: 1.06-2.36%) increase in acne outpatient visits at lag 0-7 day. Stratified analyses showed that PM2.5 effects were greater in individuals aged ≥ 25 years than those aged < 25 years, but no gender difference was found. In conclusion, short-term PM2.5 exposure was positively associated with the risk of acne outpatient visits, especially for people ≥ 25 years old.
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Acné Vulgar , Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Ambientales , Acné Vulgar/epidemiología , Adulto , Contaminantes Atmosféricos/análisis , Contaminación del Aire/análisis , China/epidemiología , Exposición a Riesgos Ambientales/análisis , Contaminantes Ambientales/análisis , Femenino , Humanos , Masculino , Pacientes Ambulatorios , Material Particulado/análisisRESUMEN
BACKGROUND: Photodynamic diagnosis (PDD) is a technique that plays a role in visualizing tumor size during the assessment of surgery. Photodynamic therapy (PDT) is a treatment apart from surgery, chemotherapy, radiotherapy, and immunotherapy that is approved for several types of tumors and nonmalignant diseases. The purpose of this study was to illustrate the efficiency and safety of PDD-guided tumor excision combined with ALA-PDT in patients with extramammary Paget's disease (EMPD). METHODS: In our study, 7 cases of EMPD were treated with PDD-guided tumor excision combined with ALA-PDT. After removal of the tumor detected by PDD, each tumor region was irradiated with 177 J/cm2 using a 635 nm laser for 15 min. Two to four ALA-PDT cycles were applied during and after surgery. EMPD was confirmed by biopsy. RESULTS: PDD may forecast tumor margins in EMPD to guide surgery, and PDT has an inhibitory effect on tumor growth. There was no local recurrence in the follow-up of 2.9 years (range, 0.8-5 years). Only one patient experienced distant recurrence under the armpit. The patients with EMPD were able to complete the treatment protocol, with good results and no significant side effects. CONCLUSIONS: The present study demonstrated an effective protocol using PDD for diagnosis and PDT for multiple therapies, showing potential as a clinical treatment for EMPD.
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Enfermedad de Paget Extramamaria , Fotoquimioterapia , Ácido Aminolevulínico/uso terapéutico , Humanos , Márgenes de Escisión , Enfermedad de Paget Extramamaria/tratamiento farmacológico , Enfermedad de Paget Extramamaria/cirugía , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/uso terapéuticoRESUMEN
A novel frequency-domain image processing method is proposed, to the best of our knowledge, to filter the noise from data collected by distributed optical fiber sensors based on Brillouin optical time-domain sensing (BOTDS). In the proposed method, we first divide a data image into subimages, and then we filter the noisy subimages by retaining the useful frequency information corresponding to the Lorentz-shape frequency spectrum and Brillouin frequency shift (BFS) transitions. The denoising performance improvements are verified by simulation and experiment. The performances in terms of temperature/strain measurement uncertainty, spatial resolution, and processing time achieved by the proposed filter are then compared with those by using a Gaussian filter and a nonlocal means (NLM) filter. In a proof-of-concept experiment with a 5.2 km length G657 sensing fiber, we achieve a temperature measurement uncertainty improvement of 27% compared with the results obtained by using the Gaussian filtering method. Furthermore, the processing speed of the proposed method is 22 times faster than that of the NLM filter under the same temperature measurement uncertainty.
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BACKGROUND: Diabetic foot ulcers (DFUs) with infection is a major clinical issue, as the infection not only potentially devastate the wound healing, but also is the factor that most often leads to amputation. Nevertheless, traditional antibiotic treatment is often insufficient to clear the infection, which could lead to side effects. Photodynamic therapy (PDT) has broad-spectral antibacterial activity. Meanwhile, it is difficult to induce antibiotic resistance. Here, we aim to evaluate the safety and efficacy of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) in the treatment of DFUs with infection. METHODS: In our study, 5 diabetic patients with infectious DFUs were diagnosed by pathological examination and the depth of wound was examined by X-Ray. All patients' wounds were firstly irradiated with 20% ALA-PDT (635 nm, 100 J/cm2, 80 mW/cm2) using the red LED to control the infection. Treatment will be combined with debridement if there is granulation necrosis or secretion on the wound surface. PDT sessions were performed weekly in all patients until healing was achieved. All patients were followed up for 0.6-1.2 years after treatment. RESULTS: In 5 patients, the DFUs with infection was completely controlled by ALA-PDT. There was no recurrence of DFUs in the follow-up of 0.9 years (range, 0.6-1.2 years) after the treatment. CONCLUSIONS: ALA-PDT treatment for DFUs with infection show successful outcomes and might ultimately avoid amputation.
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Diabetes Mellitus , Pie Diabético , Fotoquimioterapia , Ácido Aminolevulínico/efectos adversos , Antibacterianos/uso terapéutico , Diabetes Mellitus/tratamiento farmacológico , Pie Diabético/tratamiento farmacológico , Humanos , Fotoquimioterapia/métodos , Cicatrización de HeridasRESUMEN
A novel distributed strain and temperature fast measurement method in Brillouin optical time-domain reflectometry (BOTDR) system based on double-sideband (DSB) modulation is proposed. The single-wavelength probe light is modulated into dual-wavelength probe light with a fixed phase difference by using carrier suppressed DSB modulation. The interaction between the Brillouin scattering signals corresponding to dual-wavelength probe light forms a Brillouin beat spectrum (BBS). The distributed temperature and strain are obtained by only measuring the peak power trace of the BBS and one of the slope power trace of the two Brillouin gain spectrum (BGS) corresponding to dual-wavelength probe light. The proposed method does not require scanning the Brillouin spectrum and does not require using optical fibers with multiple Brillouin scattering peaks as sensing fibers, and thus features fast measurement speed and wide variety of sensing fiber types. In a proof-of-concept experiment, the temperature uncertainty of 1.3 °C and the strain uncertainty of 36.3 µÎµ are respectively achieved over a 4.5-km G.657 fiber with 3 m spatial resolution and 30 s measurement time. The experimental measurement uncertainties of temperature and strain of the proposed method are almost equivalent to that of the method by using BGS scanning and special fibers.
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In this paper, we investigate the third-order nonlinearities and optical limiting effect of Tm: YAG crystal at a wavelength of 1064 nm. We experimentally measure different energy densities (6.4, 12.8, and 19.2J/cm2) and obtain the nonlinear absorption coefficient, nonlinear refractive index, and third-order nonlinear susceptibility of Tm: YAG crystal. Z-scan results show that Tm: YAG crystal exhibits a large nonlinear absorption coefficient (3.34×10-9m/W) at the wavelength of 1064 nm. We also measure the transmittance of Tm: YAG crystals of three different lengths (7, 15, and 20 mm) to evaluate its nonlinear optical limiting performance. For the 20 mm Tm: YAG crystal, the maximum transmittance without optical limiting effect and minimum transmittance with nonlinear optical limiting effect at a 1064 wavelength nm are 84.2% and 47.8%, respectively, which indicates that Tm: YAG crystal may be a solid material for nonlinear optical limiting at 1064 nm.