Presence Of Laser Irradiation Research Articles

NH2-MIL-88B@TP-TA@CuS for photothermal catalytic synergistic antibacterial activity

Reactive oxygen species (ROS) provide a promising way to fight bacterial infection and meet the persistent challenge of antibiotic resistance. Nanoenzyme mimics natural enzyme and becomes an effective regulator of ROS level. In this study, NH2-MIL-88B with high specific surface area was selected as the core, and the covalent organic skeleton material TP-TA COF was wrapped by "sequential growth" technology. Subsequently, through the second hydrothermal treatment, the inorganic material CuS with excellent photothermal performance was integrated into the outer layer, and the NH2-MIL-88B@TP-TA@CuSX composite nanoenzyme was synthesized. Different from the traditional nano-enzyme, NH2-MIL-88B@TP-TA@CuSX nano-enzyme still has good catalytic effect under neutral conditions (pH=7). In addition, NH2-MIL-88B@TP-TA@CuSX has good near infrared (NIR) absorption rate and high photothermal conversion efficiency (PTCE is 48.7 %), which can be used for photothermal treatment (PTT) of bacteria. Mild photothermal effect can further enhance the enzyme-like catalytic activity of NH2-MIL-88B@TP-TA@CuSX, so that H2O2 can be more efficiently catalyzed to produce a large number of ROS. The experimental results in vitro show that NH2-MIL-88B@TP-TA@CuSX can effectively kill Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in the presence of laser irradiation and H2O2.

Simultaneous effect of medicinal plants as natural photosensitizers and low-level laser on photodynamic inactivation.

Photodynamic inactivation (PDI) technology is a promising alternative to antibiotics. This technology is defined as the inhibition of bacterial growth with photosensitizers while irradiated with low-level laser light in the wavelength of 532 ± 2.08nm. A challenging area in this field is selecting photosensitizers with antibacterial potential. In this paper, to enhance the antibacterial efficiency, the photosensitizers (the selected plant extracts) with a high absorption peak at the selected laser frequency, 532nm, were prepared. Low-concentration ethanolic plant extracts of Hibiscus sabdariffa and Opuntia ficus-indica were found to exhibit significant antibacterial activity against, Acinetobacter baumannii ATCC 19606 and, Staphylococcus aureus ATCC 33591 as two important human pathogenic bacteria. The effectiveness of these natural photosensitizers was measured by determining their Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values and by performing a time-killing assay in the absence and the presence of laser irradiation. Our results showed that the combination of low-level laser irradiation and the selected photosensitizers had excellent potential for treating in vitro bacterial infections. Therefore, PDI technology has great potential as a viable alternative to traditional antibiotics for combating bacterial infections. This study presents a promising avenue for further exploration of PDI and the use of laser technology in medical science.

Nano-Photosensitizer Directed Targeted Phototherapy Effective Against Oral Cancer in Animal Model.

Photodynamic therapy (PDT) has emerged as a promising strategy for oral cancer treatment. Verteporfin is a powerful photosensitizer and widely used in the treatment of macular degeneration. However, rare work has reported its potential in the treatment of oral cancer. In this study, we introduce an innovative approach of nano-photosensitizer based on Verteporfin, which was prepared by utilizing macrophage membrane to coat Verteporfin-loaded zeolitic imidazolate framework 8 (ZIF-8) for effective photodynamic therapy against oral cancer. Nanoparticle characteristics were assessed including size, zeta potential, and PDI. Cellular uptake studies were conducted using CAL-27 cells. Furthermore, inhibitory effects in both in vitro and in vivo settings were observed, ensuring biosafety. Assessment of anticancer efficacy involved tumor volume measurement, histological analyses, and immunohistochemical staining. In vitro experiments indicated that the nano-photosensitizer showed efficient cellular uptake in the oral cancer cells. Upon the laser irradiation, the nano-photosensitizer induced the generation of reactive oxygen species (ROS), leading to cancer cell apoptosis. The in vivo experiments indicated that the coating with cell membranes enhanced the circulation time of nano-photosensitizer. Moreover, the specificity of the nano-photosensitizer to the cancer cells was also improved by the cell membrane-camouflaged structure in the tumor-bearing mouse model, which inhibited the tumor growth significantly by the photodynamic effect in the presence of laser irradiation. Overall, our findings demonstrate the potential of macrophage membrane-coated ZIF-8-based nanoparticles loaded with Verteporfin for effective photodynamic therapy in oral cancer treatment. This nano-system holds promise for synergistic cancer therapy by combining the cytotoxic effects of PDT with the activation of the immune system, providing a novel therapeutic strategy for combating cancer.

Combined photodynamic therapy with chloroaluminum phthalocyanine and doxorubicin nanoemulsions in breast cancer model

Breast cancer is the most common neoplasm among women but thanks to innovative therapies, patients' prognosis has considerably improved. In this aspect, nanotechnology has been applied for cancer therapy aiming to reduce its usual side effects. In this study we aimed to evaluate the effects of nanoemulsions containing photosensitizer and chemotherapeutic agents associated with photodynamic therapy in a breast cancer in vivo model. Our results showed that synergistic treatments in which chloroaluminum phthalocyanine (NE-Pc) administered together with Doxorubicin (Dox) in the presence of laser irradiation (NE-PcDoxo + PDT) led to a reduction of 4 T1 induced breast cancer in mice, decline of tumor VEGF expression, increase in Caspase-3 expression, tissue necrosis and massive decrease in proliferative cells, as shown by Ki67 immunostaining. Furthermore, this associated treatment induced overexpression of apoptotic genes ABL1, CD70, CRADD, FASL, and NME5 and a reduction in expression of anticancer drug target genes CDK2, ERBB2, FIGF, IGF2, PARP4 and PGR. These results validate this treatment as a promising alternative to improve the currently applied anticancer strategies.

Effects of photo-stimulation with laser or LED on the composition of Xanthan gum produced in media containing distilled water or dialyzed or not produced water by means of Raman spectroscopy

Oil is expected to continue to be one of the most important sources of energy in the world and world's energy matrix for the foreseeable future. However, high demand for energy and the decline of the production of oil fields makes oil recovery a challenge. Most techniques used for the recovery process are expensive, non-sustainable and technically difficult to implement. In this context, microbial enhanced oil recovery (MEOR) represents an attractive alternative. It employs products derived from the metabolism of microorganisms that produce biopolymers. Certain bacteria species (e.g., Xanthomonas campestris) produce polysaccharides (exopolysaccharides – EPS) such as the well-known Xanthan gum (XG). We hypothesized that the use of produced water (PW) water in combination photo-stimulation with laser/LED could influence the production and composition of XG. Raman spectroscopy has been used for qualitative and quantitative evaluation of the biochemical composition of XG biopolymer under light stimulation. X. campestris cultures in either distilled water or dialysis-produced water were studied under the absence or presence of laser irradiation (λ = 660 nm, CW, spot size 0.040 cm2, 40 mW, 444 s, 8.0 J/cm2) or LED (λ = 630 nm ± 2 nm, CW, spot size 0.50 cm2, 140 mW, 500 s, 12 J/cm2). XG produced by these cultures was analyzed by Raman spectroscopy at 1064 nm excitation and subjected to principal component analysis (PCA). Results of the exploratory analysis and ANOVA general linear model (GLM) suggested that the extent of XG and pyruvate (pyruvyl mannose) production was affected differentially in X. campestris when cultured in distilled water plus LED photo-stimulation versus dialysis-produced water plus LED photo-stimulation. XG production increased in the distilled water culture. In contrast, both pyruvate acetyl mannose content went up in the dialysis-water culture. These results open a wide field of opportunities in the use of metal-enriched cultures in combination with photo-biomodulation to direct and optimize bacterial production of compounds (i.e., XG) that may be of great benefit in the implementation of sustainable practices for oil extraction.

Hydroxyapatite nanocomposite as a potential agent in osteosarcoma PDT.

Using Nanoplatforms as a hauler for photosensitizers is a bespoke paradigm to improve its bioavailability and to boost the PDT efficacy. Herein, the photodynamic cytotoxicity of methylene blue (MB) loaded on hydroxyapatite nanoparticles (HA-NPs) was tested against human osteosarcoma-derived cells (Saos-2 cell line). HA-NPs and HA-NPs loaded with MB (HA-NPs-MB) were prepared by a chemical precipitation method and characterized by TEM, Zeta potential, FTIR, and XRD. TEM images revealed that HA-NPs have a rod shape with a diameter of 14-17 nm and length around 46-64 nm. FTIR and Zeta potential confirmed the adsorption of cationic MB on HA-NPs. XRD pattern was identical to the standard XRD pattern of HA-NPs. Incubation of Saos-2 cells (24 h) with HA-NPs-MB then irradiation of cells (5 min) with a diode laser (808 nm), causes a higher decrement of cell viability (determined by MTT assay) than that caused by free MB. The LC50 was 57.53 µg/mL and 86.99 µg/mL for HA-NPs-MB and free MB, respectively. Thus, the nanoformulation of MB greatly reduced the dose of MB required for effective PDT. This study also investigated the mode of cell death after incubation of cells with free MB or HA-NPs-MB composite then exposure to laser radiation. The results revealed that the majority of cells died by apoptosis while a minor fraction of cells died by necrosis, especially in the case of HA-NPs-MB. Levels of caspase-3 and death receptor-4 (DR-4) were more elevated in the case of HA-NPs-MB than free MB. The effect of the prepared nanocomposite and free MB on Raw murine macrophage (RAW 264.7) viability was also examined using the MTT assay. The results indicated that HA-NPs-MB in the presence of laser has a great cytotoxic effect on macrophage cells compared to other treatments. This may present an advantage through decreasing macrophage that promotes tumor growth. In conclusion, HA-NPs-MB nanocomposite surmounts free MB and HA-NPs in destroying macrophage cells and Saos-2 cells through apoptosis in the presence of laser irradiation. This study introduces a thorough and new insight on osteosarcoma (cancer cell line Saos-2) PDT using HA-NPs-MB exploiting the biosafety of HA-NPs.

Colloidal synthesis of tunably luminescent AgInS-based/ZnS core/shell quantum dots as biocompatible nano-probe for high-contrast fluorescence bioimaging.

Tremendous demands for simultaneous imaging of biological entities, along with the drawback of photobleaching in fluorescent dyes, have encouraged scientists to apply novel and non-toxic colloidal quantum dots (QDs) in biomedical researches. Herein, a novel aqueous-phase approach for the preparation of multicomponent In-based QDs is reported. Absorption and photoluminescence emission spectra of the as-prepared QDs were tuned by alteration of QDs' composition as Zn-Ag-In-S/ZnS, Ag-In-S/ZnS and Cu-Ag-In-S/ZnS core/shell QDs. In order to reach reproducibly intense and tunable light-emissive colloidal QDs with green, amber, and red color, various optimization steps were carefully performed. The structural characterizations such as EDX, ICP-AES, XRD, TEM and FT-IR measurements were also carried out to demonstrate the success of the present method to prepare extremely quantum-confined QDs capped with functional groups. Then, to ensure their promising biomedical applications, the generated intracellular reactive oxygen species (ROS) by QDs were quantitatively and qualitatively measured in dark conditions and under 405nm laser irradiation. Our results verified an enhancement in the generation of reactive oxygen species (ROS) and cytotoxic effects in the presence of laser irradiation while their muted toxic effects in dark conditions confirmed biocompatible properties of un-excited In-based QDs. Moreover, bioimaging analysis revealed strong merits of the suggested synthetic route to achieve ideal fluorescent QDs as bright/multi-color optical nano-probes in imaging and transporting pumps in the cell membrane. This further emphasized the potential ability of the present AgInS-based/ZnS QDs in obtaining required results as theranostic agents for simultaneous treatment and imaging of cancer. The harmonized advantages in simplicity and effectiveness of synthesis procedure, excellent structural/optical properties enriched with confirmed biomedical merits in high contrast imaging and potential treatment highlight the present work.

Core-matched nanoassemblies for targeted co-delivery of chemotherapy and photosensitizer to treat drug-resistant cancer

Emergence of drug resistance in tumors causes therapeutic failure or tumor relapse. Combination of chemotherapy and photodynamic therapy holds significant promise to treat drug-resistant tumors. However, stubborn hydrophobicity of photosensitizer (PS), low encapsulation efficiency and leaking problem of PS in organic carrier, and disparate physicochemical properties of PS and chemotherapeutics make the combination unachievable. Thus how to efficiently co-deliver the two functional agents to enable photo-chemotherapy seems to be one of the key challenges. Here, core-matched technology (CMT) was developed to realize efficient co-delivery of PS and chemotherapeutics, in which PS verteporfin (VP), tumor angiogenesis-targeting iNGR peptide and poly(lactic acid) (PLA) were respectively pre-modified with D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), and the conjugates self-assembled into iNGR-modified and VP conjugated nanoassemblies (iNGR-VP-NA) with chemotherapeutic agent docetaxel (DTX) loaded in the hydrophobic core. The obtained iNGR-VP-NA-DTX was characterized by mean size of 166.0 ± 9.2 nm and morphology of uniformly spherical shape. In vitro, with the assistance of laser, iNGR-VP-NA-DTX exhibited higher cellular uptake, stronger cytotoxicity in HUVEC cells, drug-resistant HCT-15 tumor cells and more effective inhibition of tube formation than iNGR-VP-NA-DTX without laser or VP-NA-DTX with laser. After intravenously injected into mice, through the near-infrared light emitted by VP, iNGR-VP-NA exhibited improved accumulation compared to VP-NA in drug-resistant HCT-15 tumor. Besides, iNGR-VP-NA-DTX with laser enhanced inhibition of angiogenesis and induced severe apoptosis and necrosis in tumor tissues along with minimal impact to normal areas. These evidences demonstrated that iNGR-VP-NA-DTX was of great potential to treat drug-resistant tumors via efficient angiogenesis-targeted photo-chemotherapy. Statement of SignificanceCombination of chemotherapy and photodynamic therapy is thought to be a potential approach to treat drug-resistant cancer. However, it is difficult to realize optimized photo-chemotherapy in one nano-system. Here, iNGR-modified nanoassemblies is created based on core-matched nanotechnology to realize targeted photo-chemotherapy. In this study, the improved co-loading of chemotherapy and photosensitizer in the nanoassemblies exerted a synergistic anti-tumor effect and the decoration with iNGR enhanced tumor-targeting efficiency. In the presence of laser irradiation, the nanoassemblies exhibited enhanced and targeted anti-tumor efficacy in drug-resistant HCT-15 tumor both in vitro and in vivo.

Preparation of multifunctional nanoparticles targeting tongue cancer and in vitro study

This study aims to prepare docetaxel (DOC)-loaded multifunctional nanoparticles containing indocyanine green (ICG) and perfluorohexane (PFH) as targeted drug delivery system, which is supplemented with stromal cellderived factor-1 (SDF-1), and characterize their properties. Multifunctional nanoparticles were prepared by using the double emulsion method. SDF-1 was covalently conjugated to the surface of the nanoparticles through thioether bonding. Their particle size, distribution, and surface potential were determined with the Malvern measuring instrument. The conjugation of SDF-1 was evaluated by confocal laser scanning microscope. Encapsulation efficiency (ELC), drug loading capacity (DLC), and release regularity of the nanoparticles were determined by high-performance liquid chromatography (HPLC). In vitro photothermal property was recorded by a thermal imager. The in vitro imaging capacity was observed by a photoacoustic instrument and an ultrasonic diagnostic apparatus. Targeting capability was assessed by flow cytometry. The cell activity on SCC-15 cells was checked by CCK-8 method. The targeted multifunctional nanoparticles showed regularly sphericity. The diameter was (502.88±17.92) nm. The zeta potential was (-11.5±3.15) mV. ELC was 54.12%±1.74%. DLC was 1.08 mg·mL-1. In vitro drug release was initially fast and subsequently slow. The photothermal characteristics were related to the concentration; the higher the concentration, the higher the temperature. Nanoparticles could detect significant photoacoustic and ultrasound signals. The in vitro targeting rate was 89.99%. No significant differences of cell viability in the SINPs groups were observed at each concentration (P>0.05). The inhibition effect of DOC-SINPs was stronger than that of SINPs whether or not in the presence of laser irradiation among the groups of 150 and 200 μg·mL-1 (P< 0.05). Multifunctional nanoparticles for diagnosis and treatment were successfully prepared and displayed dualmode ultrasound/photoacoustic imaging and antitumor effects of chemotherapy and photothermal therapy.

Gum Arabic-encapsulated gold nanoparticles for a non-invasive photothermal ablation of lung tumor in mice.

In our previous work, we have extensively evaluated the physiochemical characteristics of Gum Arabic-encapsulated gold nanoparticles (GA-AuNPs; 15-18nm) and reported their effectiveness in stopping the tumor initiation via inhibiting the pre-neoplastic lesions in liver. The rationale of this study is to detect the efficiency of using GA-AuNPs in photothermal application as a non-invasive technique against lung tumor. We investigated the cytotoxicity of GA-AuNPs on A549 cells, and then studied their apoptotic, anti-inflammatory, lipid peroxidation and anti-neovascular effect in in vivo model using a chemically-induced lung cancer in mice. The histopathological changes due to GA-AuNPs were investigated. In the presence of laser irradiation, GA-AuNPs had a considerable cytotoxicity against A549 cells. The treatment of lung tumor-bearing mice with GA-AuNPs followed by laser exposure enhanced the apoptotic pathway and this was obvious from the histopathological investigations and the elevations in cytochrome-c, death receptor 5 and the subsequent upregulation of caspase-3, we also reported a significant reduction in the levels of the inflammatory mediator TNF-α and the angiogenesis inducer VEGF. An induction of lipid peroxidation was also reported upon treatment with either GA or GA-AuNPs. GA-AuNPs showed no cytotoxicity in the absence of light, however the combination of GA-AuNPs with laser induced cell death in lung tumor tissues with a reduction in the inflammation and angiogenesis together with an elevation in lipid peroxidation, suggesting the potential use of these functionalized nanoparticles as a promising photothermal non-invasive treatment modality.

Immunohistochemical evaluation of vascular endothelial growth factor and transforming growth factor-beta on osseointegration of CpTi implant radiated by low level laser therapy

Background: Dental implants provide a unique treatment modality for the replacement of lost dentition .This is accomplished by the insertion of relatively inert material (a biomaterial) into the soft and hard tissue of the jaws, there by providing support and retention for dental prostheses. Low level laser therapy (LLLT) is an effective tool used to prompt bone repair and modeling post surgery; this has referred to the biostimulation effect of LLLT. The aims of this study were to evaluate the immmunohistochemical expression of vascular endothelial growth factor (VEGF) and transforming growth factor -beta (TGF-β) in experimental and control groups with mechanical test. Materials and Methods: Thirty two adult New Zealand white rabbits used, screw titanium implants inserted in the tibia. The right side is considered as experimental groups and the left side considered as control groups. Low power diode laser (GaAlAs) with wave length (904nm) and (5mW) power applied with the right screw implants. The sample divided into four groups, eight rabbits are sacrificed at four interval 4days, 1 weeks, 2weeks, and 6weeks respectively. immunohistochemical (VEGF&TGF-β), were done for each interval with mechanical test in 2 and 6 weeks . Results: Immunohistochemical findings revealed high positive expression for VEGF and TGF-β in experimental implant in comparison to control one and the acceleration of bone formation and more rapid healing process in the screw implant with laser irradiation than in the control implant. Removal torque test showed dramatic increase with the presence of laser irradiation especially with advancing time. Conclusion: This study was illustrated that the LLLT applications enhance bone formation and increase osseointegration.

P0131 Efficacy of gum arabic-conjugated gold nanoparticles as a photothermal therapy for lung cancer: In vitro and in vivo approaches

Background Gum arabic-conjugated gold nanoparticles (GA-AuNPs; 15–18 nm) have been previously well characterised in vitro and in vivo for their stability; however, their cytotoxicity and pharmacological effects, with and without laser exposure, is largely unknown. Methods We investigated the cytotoxicity of GA-AuNPs in A549 lung cancer cells and the change in inflammatory cytokine, death receptors, lipid peroxidation, apoptosis mediators, and histopathological changes in lung tumour-bearing mice with or without laser irradiation. Findings In-vitro studies showed that GA-AuNPs with laser irradiation had significant cytotoxicity against A549 cells, while they had no cytotoxicity in the absence of laser. Gum arabic is cellularly safe in the absence or presence of laser irradiation. In-vivo studies showed that GA-AuNPs with laser resulted in significant alterations in lung tumours in mice, inducing apoptosis through upregulation of caspase-3, death receptor (DR5), and enhanced release of cytochrome C. Treatment with GA-AuNPs and laser inhibited the induction of TNF- α and VEGF in tumour-bearing mice and increased lipid peroxidation. Gum arabic was biologically inactive expect when combined with laser irradiation in healthy and in tumour-bearing mice, where it led to elevated lipid peroxidation. Interpretation Gum arabic and GA-AuNPs separately are safe. Co-administration of GA-AuNPs with laser irradiation induced cytotoxicity, apoptosis, decreased inflammation and angiogenesis, and enhanced lipid peroxidation.

Polyethylene Glycol and Polyethylenimine Dual‐Functionalized Nano‐Graphene Oxide for Photothermally Enhanced Gene Delivery

Graphene oxide (GO) has been extensively explored in nanomedicine for its excellent physiochemical, electrical, and optical properties. Here, polyethylene glycol (PEG) and polyethylenimine (PEI) are covalently conjugated to GO via amide bonds, obtaining a physiologically stable dual-polymer-functionalized nano-GO conjugate (NGO-PEG-PEI) with ultra-small size. Compared with free PEI and the GO-PEI conjugate without PEGylation, NGO-PEG-PEI shows superior gene transfection efficiency without serum interference, as well as reduced cytotoxicity. Utilizing the NIR optical absorbance of NGO, the cellular uptake of NGO-PEG-PEI is shown to be enhanced under a low power NIR laser irradiation, owing to the mild photothermal heating that increases the cell membrane permeability without significantly damaging cells. As the results, remarkably enhanced plasmid DNA transfection efficiencies induced by the NIR laser are achieved using NGO-PEG-PEI as the light-responsive gene carrier. More importantly, it is shown that our NGO-PEG-PEI is able to deliver small interfering RNA (siRNA) into cells under the control of NIR light, resulting in obvious down-regulation of the target gene, Polo-like kinase 1 (Plk1), in the presence of laser irradiation. This study is the first to use photothermally enhanced intracellular trafficking of nanocarriers for light-controllable gene delivery. This work also encourages further explorations of functionalized nano-GO as a photocontrollable nanovector for combined photothermal and gene therapies.

The influence of Nd:YAG laser irradiation on Fluoroptic® temperature measurement: an experimental evaluation

The aim of this study was to experimentally evaluate temperature monitoring with a Fluoroptic® temperature probe in the presence of laser irradiation from a Nd:YAG laser, which is mainly used for clinical MR-guided laser-induced interstitial thermotherapy. Temperature measurements were performed using a Fluoroptic® probe in comparison to a thermocouple probe in a gel phantom and an ex vivo pig liver at distances of 6.5 to 14 mm to the laser applicator (laser energy of 30.8 W). To evaluate the artifacts in the temperature measurement, the laser was turned on and off three times during the entire experiment. A comparison of the fiber-optic measurements with MR thermometry was also performed in pig liver by means of the proton resonance frequency method at a distance of 6 mm. Depending on the distance, the temperature measured by the fiber-optic probe deviated from the thermocouple probe temperature. The phantom deviations of 0.4 to 34.3 % were observed. The differences in the liver were smaller and ranged from 1.6 to 5.2 %. The Bland-Altman mean of differences between MR and fiber-optic temperature measurements was 0.02 °C and the 95 % limits of agreement value was ± 2.25°C. During laser application, considerable artifacts occurred in the Fluoroptic® measurements in short distances which was induced by laser energy absorption by the probe coating. No artifacts were verifiable at a distance of 14 mm in both mediums. The good conformity with MR thermometry resulted from the shorter turn-on times of the laser since the laser irradiation had only a minor effect on the measurements.

Observation of Single Molecular Motion About Biological Supramolecular Enantiodifferentiating Photoreaction using Diffracted X-Ray Tracking

Serum Albumin (SA) is one of the transport proteins which were discovered in plasma. SA have chiral environment where bind to various molecules such as organic molecule, amid acid, metal ion etc. Delivering 1,1’-bi-2-naphthol (Binol) by drops into Bovine Serum Albumin (BSA) and Human Serum Albumin (HSA) shows red shift upon absorption spectra and induced circular dichroism upon circular dichroism spectra over the 300 nm wavelength range and induced chirality.[1] Furthermore, (S)-Binol had more selectivity than (R)-Binol in binding to SA. Irradiating at 365 nm, Binol is photoinversed in high enantiomeric excess (ee) in the presence of BSA or HSA. Achiral 2-Anthracenecarboxylicacid (AC) is induced chirality in the presence of various SA.[2] As in the case of Binol and SA complexes, AC and SA complexes undergo photocyclodimerization in high ee.Moreover, the movement of AC in 2nd and 3rd site of HSA was observed.In this study, we measured Brownian motion on biological supramolecular reaction using Diffracted X-ray Tracking (DXT) at beam lines of NW14A, PF-AR and BL40XU, SPring8. We tracked diffracted spots from gold nanocrystals (φ50-80 nm) labeled on each SA as host in real time. We also used Quartz Crystal Microbalance (QCM) and Dynamic Light Scattering (DLS) to explore the size of complexes. We measured motions of Binol within SA and AC within SA in various conditions such as presence of laser irradiation or varied composition ratio upon complexes. in this presentation, we report the dynamics of photoinduced biological supramolecular reaction in SA with Binol and AC.[1] N. Levi-Miniz and M. Zandomeneghi, J. Am. Chem. Soc. 114, 9300 (1992).[2] M, Nishijima; T, Wada; T, Mori; T, C. S. Pace; C, Bohne; Y, Inoue, J. Am. Chem. Soc. 2007, 129, 3478.

Energy dissipation of ion beam in two-component plasma in the presence of laser irradiation

AbstractWe use a two-dimensional particle-in-cell simulation to investigate the dynamic polarization and stopping power for an ion beam propagating through a two-component plasma, which is simultaneously irradiated by a strong laser pulse. Compared to the laser-free case, we observe a reduction in the instantaneous stopping power that initially follows the shape of the laser pulse and becomes particularly large as the laser frequency approaches the plasma electron frequency. We attribute this large reduction in the ion stopping power to an increase in plasma temperature due to the energy absorbed in the plasma from the laser pulse through the process of wave heating. In addition, dynamic polarization of the plasma by the ion is found to be strongly modulated by the laser field.

Photoacoustic analysis of bone osteogenesis to different doses of laser irradiation

The photoacoustic analysis of fractured bone callus to different consolidation times in the presence of laser irradiation was performed. In this study we take into account the fractured tibias of sacrified Wistar rats. By using the photoacoustic spectroscopy technique it was possible to determine, for different doses of laser irradiation (doses of 25Jcm−2) the presence of characteristic absorption band of p-Nitrophenylphosphatase (p-Npp) in the fractured bone callus. The evolution of bone consolidation was accelerated by laser radiation when compared with nonirradiated fractured bones.

Generalized electron fluid equations in the presence of laser irradiation

Generalized fluid models have become increasingly popular for incorporating kinetic effects in hydrodynamic studies of laser–plasma interactions. However, their transport coefficients depend on the source of the thermal perturbation, which leads to difficulties, since both inverse-bremsstrahlung heating and pdV work drive these perturbations. Treating these sources separately using a model with two energy equations is proposed. Tested against electron Fokker–Planck simulations, this model reproduces both Landau damping of ion-sound waves and the correct response to inverse bremsstrahlung.