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Room temperature phosphorescence (RTP) organic emitters have gained increasing attention in the fields of lighting, security and bioimaging. However, lack of clear mechanism and universal methods of regulating RTP property impeded the further development of RTP materials. Most importantly, the long lifetime and high quantum yield (QY) of RTP can hardly be achieved at the same time. Herein, we report a molecular design strategy to improve both lifetime and QY of RTP through intramolecular interaction. The enhancement of lifetime and QY were up to one order, respectively by introducing S···O noncovalent intramolecular interactions into the molecule. The X-ray single crystal analysis and theoretical calculations were performed together to give the solid evidence that the intramolecular interaction can not only suppress the nonradiative transition but also stabilize the triple states. This study provided a novel idea of developing high-performance RTP materials.

As a new rapid prototyping technology, the laser melting deposition technology not only has the advantages of fast forming, high efficiency, but also free control in the design and production chain. Therefore, it has drawn extensive attention from community.With the continuous improvement of steel performance requirements, high performance low-carbon alloy steel is gradually integrated into high-tech fields such as aerospace, high-speed train and armored equipment.However, it is necessary to further explore and optimize the difficult process of laser melting deposited alloy steel parts to achieve the performance and shape control.This article took the orthogonal experiment on alloy steel powder by laser melting deposition ,and revealed the influence rule of the laser power, scanning speed, powder gas flow on the quality of the sample than the dilution rate, surface morphology and microstructure analysis were carried out.Finally, under the optimum technological parameters, the Excellent surface quality of the alloy steel forming part with high density, no pore and cracks was obtained.

In the working process of one Beach-Cleaner snatch institution, the second knuckle arm angular speed was too high, which resulted in the pick-up device would crash into the basic arm in the fold process. The rational position of joint to reduce the second knuckle arm angular speed and the force along the axis direction of the most dangerous point can be obtained from the kinematics simulation of snatch institution in the code of Automatic Dynamic Analysis off Mechanical Systems (ADAAMS). The feasible of scheme was validated by analyzing the optimized model in the software of ANSYS. The analysis results revealed: the open angle between the basic arm and the second knuckle arm improved from 125.0° too 135.24°, thee second knuckle arm angular speed decreased from 990.74rad/s to 58.53 rad/s, Not only improved work efficiency of snatch institution, but also prolonged its operation smoothness.

Narrow-band time-frequency entangled biphotons are generated from spontaneous four-wave mixing in cold atom clouds. The coherence time of the entangled biphotons can be extended to sub-microseconds by the slow light effect. The temporal wavefunction of the biphotons can be manipulated through modulating the spectral or spatial mode of the controlling laser beams. Concerning a pair of entangled biphoton and the resulting heralded single photon, it was commonly believed that, time-frequency entanglement damages the temporal purity of the single photon. However, the case is totally different for biphotons with long coherence time which is far beyond the time resolution of single-photondetectors. We demonstrate that, the single photon heralded from these time-frequency entangled biphotons is in a pure temporal state. Therefore, single photons are able to be shaped through the time-frequency entanglement with their partner photons, while the single photons could be found to be still in a pure state and thus useful for quantum information processing and communication technology.

Immunotherapy of brain tumors involves the stimulation of an antitumor immune response. This type of therapy can be targeted specifically to tumor cells thus sparing surrounding normal brain. Due to the presence of the blood-brain barrier, the brain is relatively isolated from the systemic circulation and, as such, the initiation of significant immune responses is more limited than other types of cancers. The purpose of this study was to show that the efficacy of tumor primed antigen presenting macrophage vaccines could be increased by: (1) PDT of the priming tumor cells, and (2) injection of allogeneic glioma cells directly into brain tumors. Experiments were conducted in an in vivo brain tumor model using Fisher rats and BT4C (allogeneic) and F98 (syngeneic) glioma cells. Preliminary results showed that vaccination alone had significantly less inhibitory effect on F98 tumor growth compared to the combination of vaccination and allogeneic cell (BT4C) injection.

Macrophages loaded with gold nanoshells (AuNS), that convert near infrared light to heat, can be used as transport vectors for photothermal hyperthermia of tumors. The purpose of this study was to investigate the effects of combined macrophage mediated photothermal therapy (PTT) and PDT on head and neck squamous cell carcinoma (HNSCC). The results provide proof of concept for the use of macrophages as a delivery vector of AuNS for photothermal enhancement of the effects of PDT on squamous cell carcinoma. A significant synergy was demonstrated with combined PDT and PTT compared to each modality applied separately.

Background and Objective: We have evaluated the ability of ALA-mediated PDT to selectivly open the BBB in rats. This will permit access of chemotherapeutic agents to brain tumor cells remaining in the resection cavity wall, but limit their penetration into normal brain remote from the site of illumination. Study Design/Materials and Methods: ALA-PDT was performed on non-tumor bearing inbred Fischer rats at increasing fluence levels. Contrast T1-weighted high field (3 T) magnetic resonance imaging (MRI) scans were used to monitor the degree of BBB disruption. Results: PDT at increasing fluence levels between 9 and 17 J demonstrated an increasing contrast flow rate. The BBB was found to be disrupted 2 h following PDT and 80 - 100 % restored 72 h later at the lowest fluence level. No effect on the BBB was observed if 26 J of light was given in the absence of ALA. Conclusion: ALA-PDT was highly effective in opening the BBB in a localized region of the brain. The degradation of the BBB was temporary in nature at fluence levels of 9 J, opening rapidly following treatment and significantly restored during the next 72 h. No signs of permanent tissue damage were seen on histological sections at this fluence level.

Since the first report by Agarwal et al in 1991 on apoptotic induction by photodynamic therapy (PDT) with chloroaluminium phthalocyanine a large number of papers have come out to show that PDT can induce cell death through apoptosis. This finding may provide potential clinical impact on, for example, those tumor cells resistant to any cancer therapy. The present paper briefly reviews apoptosis with emphasis on PDT-induced apoptosis with hexaminolevulinate.

Introduction: Failure of treatment for high grade gliomas is usually due to local recurrence at the site of surgical resection indicating that a more aggressive form of local therapy, such as PDT, could be of benefit. PDT causes damage to tumor cells as well as degradation of the blood brain barrier (BBB). We have evaluated the ability of ALA mediated PDT to open the BBB in rats. This will permit access of chemotherapeutic agents to brain tumor cells remaining in the resection cavity wall, but limit their penetration into normal brain remote from the site of illumination. Materials and Methods: ALA-PDT was performed on non tumor bearing inbred Fisher rats at increasing fluence levels. T2 weighted MRI scans were used to evaluate edema formation and post-contrast T1 MRI scans were used to monitor the degree BBB disruption which could be inferred from the intensity and volume of the contrast agent visualized. Results. PDT at increasing fluence levels between 9J and 26J demonstrated an increasing contrast flow rate. No effect on the BBB was observed if 26J of light were given in the absence of ALA. A similar increased contrast volume was observed with increasing fluence rates. The BBB was found to be disrupted 2hrs. following PDT and 80-100% restored 72hrs later. Conclusion: PDT was highly effective in opening the BBB in a limited region of the brain. The degradation of the BBB was temporary in nature, opening rapidly following treatment and significantly restored during the next 72 hrs.© (2008) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Introduction: Failure of treatment for high grade gliomas is usually due to local recurrence at the site of surgical resec-tion indicating that a more aggressive form of local therapy could be of benefit. Photodynamic therapy (PDT) is a local form of treatment involving the administration of a tumor-localizing photosensitizing drug that is activated by light of a specific wavelength The results of in vitro experiments indicated that PDT, given at low fluence rates was substantially more effective at inhibiting glioma spheroid growth than short term high fluence rate regimes. This prompted the initia-tion of in vivo studies of low fluence rate 5-aminolevulinic acid (ALA) PDT in a rat glioma model. Methods:BT4C cell line tumors were established in the brains of inbred BD- IX rats. Eighteen days following tumor induction the animals were injected with 125 mg/kg ALA ip. and four hours later light treatment at various fluences and fluence rates were given after the introduction of an optical fiber. Tumor histology and animal survival were examined. Results: In vitro experiments verified that the cell line was sensitive to ALA PDT. Microfluorometry of frozen tissue sections showed that PpIX is produced with a greater than 20:1 tumor to normal tissue selectivity ratio four hours after ALA injection. Histological examination demonstrated neutrophil infiltration and tumor central necrosis in low fluence rate treated tumors. Conclusions: Low fluence rate long term ALA mediated PDT had a more pronounced effect on tumor histology than single shot short duration treatments at similar total fluence levels.

The distribution of protoporphyrin IX (Pp IX) was investigated in a novel animal model followng administration of 5-aminolevulinic acid (ALA) or its hexyl ester (h-ALA). Pre-cultured tumor spheroids prepared from cell lines or tumor biopsy fragments were injected into the brains of immunodeficient rats. Approximately 3 months after spheroid implantation, Rowett nude rats were injected intra-cranially with the maximum tolerable ALA or h-ALA dose. Animals were sacrificed 4 hours post-injection and their brains removed for fluorescence microscopy analysis. The primary finding of this study is that, in the tumor biopsy model, the tumor-to-normal brain PpIX fluorescence ratio is approximately 3 times higher following direct in situ h-ALA adminstration compared to ALA.

The probability of achieving local control with current single-shot, intraoperative PDT treatments of intracerebral gliomas seems improbable due to the length of time required to deliver adequate light fluences to depths of 1 - 2 cm in the resection margin. The results of in vitro experiments indicated that PDT, repeated at weekly intervals, was substantially more effective at inhibiting glioma spheriod growth than single treatment regimes. This prompted the initiation of in vivo studies of repetitive PDT in a rat glioma model. BT4C cell line tumors were established in the brains of inbred BD-IX rats. Three days following tumor induction, the animals were injected with 250 mg/kg ALA i.p. and four hours later, after the introduction of an optical fiber, light treatment at various radiant energies was given over a 10- to 30-minute interval. Two additional treatments were given at weekly intervals. In vitro experiments verified that spheroids derived from the cell line were sensitive to ALA PDT. Microfluorometry of frozen tissue sections showed that PpIX is produced with a 10 - 20:1 tumor to normal tissue selectivity ratio four hours after 250 mg/kg ALA i.p. Toxic radiant energy levels for ALA PDT have been determined.

Photodynamic therapy (PDT)-induced kinetics of apoptosis were studied in V79 cells using several differently localized photosensitizing dyes, mostly tetraphenylporphine derivatives. Apoptotic fractions were quantified by flow cytometry after staining the samples by the terminal deoxynucleotidyl transferase (TdT)-assay. Methylene blue derivative (MBD), a new dye for PDT, and 5-aminolevulinic acid (ALA)-induced protoporphyrin IX that are both localized in mitochondria, induced apoptosis rapidly within hours after PDT. With MBD it was shown that rapid apoptosis was induced only with dye concentration above a certain threshold. With a lower dye concentration apoptosis was delayed more than one day and was induced due to inhibition of oxidative phosphorylation. After PDT with two membrane localized dyes, tetra(3- hydroxyphenyl)porphyrin (3THPP) and Photofrin, maximal induction of apoptosis took about 12 h. With two lysosomal localized sulfonated meso-tetraphenylporphines (TPPS2a and TPPS4) no apoptosis was induced until more than 12 h after PDT. The results are discussed in relation to evidence in the literature on the nature of possible pathways involved.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The initial clinical performance of a research prototype digital radiographic system based on a large-field (2016-channel) kinestatic charge detector and data acquisition system is discussed. The first clinical images from the large-field system are compared with images of the same patients taken with commercial systems. Future directions are discussed.

Some key data concerning the pharmacokinetics of PCT photosensitizers are reviewed. The following topics are discussed: The binding of photosensitizers to serum proteins, and the significance of LDL binding for tumor localization, the distribution of sensitizers among different tissue compartments and the significance of extracellular proteins and other stromal elements, such as macrophages, low tumor pH, leaky vasculature and poor lymphatic drainage for tumor selectivity of drugs, the retention and excretion of sensitizers, and intracellular pharmacokinetics. Furthermore, the usefulness of fluorescence measurements in the study of sensitizer pharmacokinetics is briefly discussed. A key observation is that 1O2 has a short radius of action. Since practically all PCT sensitizers act via the 1O2 pathway, only targets with significant sensitizer concentrations can be damaged. A given number of 1O2 entities generated in different organelles (mitochondria, lysosomes, plasma membrane, etc.) may lead to widely different effects with respect to cell inactivation. Similarly, sensitizers localizing in different compartments of tissues may have different photosensitizing efficiencies even under conditions of a similar 1O2 yield.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

All photosensitizers applied in experimental and clinical photochemotherapy (PCT) of cancer are degraded during light exposure. Under certain conditions this may be a disadvantage since larger light fluences are needed to destroy the malignant tissue. However, photodegradation may also offer an advantage: if the applied dose of sensitizer is so low that most of it is photodegraded before normal tissue is destroyed, but still large enough to sensitize the tumor to destruction, one may achieve a larger tumor to normal tissue therapeutic ratio than when using a higher dose of sensitizer. Tumors usually contain two to ten times higher concentrations of sensitizers than do the surrounding normal tissues. We have studied the photodegradation of a number of sensitizers, including Photofrin (PII), benzoporphyrin derivative mono acid ring A (BPD), chlorin e6 (Chle6) 5-aminolevulinic acid (ALA)- induced protoporphyrin IX (PpIX), meso-tetrahydroxyphenyl-chlorin (m-THPC), meso- tetrahydroxyphenyl-porphyrin (m-THPP) tetraphenylporphine tetrasulfonated (TPPS4), aluminum phthalocyanine disulfonated (AlPcS2), tetrasulfonated (AlPcS4) and zinc phthalocyanine (ZnPc) in liposomes. The sensitizers were injected in Balb/c nude mice and exposed to light from an argon pumped dye laser, tuned to the appropriate therapeutic wavelength at a fluence rate of 100 mW/cm2. The sensitizer fluorescence in the laser- exposed skin was monitored by a fiberoptic probe coupled to a fluorescence spectrometer. The kinetics of the fluorescence decay during PCT were, in all cases, nonexponential but differed from dye to dye. Chle6 and m-THPC were found to be the most photolabile sensitizers. AlPcS4 and AlPcS2 and, to a minor degree, TPPS4 showed a peculiar fluorescence increase during PCT, similar to what we have found earlier for these sensitizers in cells in vitro. The fluorescence increase is indicative of lysosomal localization and perforation of the lysosomes during PCT.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Topically applied ALA-PDT for human nodular basal cell carcinoma has encountered some problems, one of which is that the concentration of ALA-induced PpIX is in some cases too low to sensitize complete tumor destruction. Our present study, by means of an optical-fiber based point monitoring system in situ, has shown that the fluorescence intensity of PpIX was significantly higher in the normal skin of nude mice after topical application of ALA and desferrioxamine (DF) or in combination with DMSO than that of ALA alone or ALA plus DMSO. These data indicate that DF has an effect on enhancing the production of ALA- induced PpIX in the mouse skin. Thus, there may clinically be advantages of using ALA and DF over ALA alone in PDT of superficial skin lesions.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

By means of scanning and transmission electron microscopy the subcellular target sites of photodynamic therapy (PDT) with derivatives of sulfonated aluminum phthalocyanine (AlPcS 1 , AlPcS 2 , AlPcS 3 , and AlPcS 4 ) were studied in a human melanoma LOX cell line. It was found that PDT with AlPcS 1 or AlPcS 2 damaged mainly the biomembraneous system of the cells, such as cytoplasmic membrane, mitochondria, endoplasmic reticulum, etc., while AlPcS 3 - or AlPcS 4 - induced PDT largely destroyed the lysosomes. However, none of the AlPcS n s led to nuclear damage at an early stage after PDT. The subcellular photodynamic targets of the derivatives of AlPcS n are related to the subcellular localization pattern of the dye in the LOX cells.

The initial performance of a digital radiographic system incorporating a large-field (2016- channel) kinestatic charge detector and data acquisition electronics is discussed. The measured modulation transfer function of the system is 20% at 4 cy/mm. The measured detective quantum efficiency is 40 - 60%. These results are comparable with or better than those of current clinical (rare-earth film-screen and storage phosphor) systems. First images from the large-field system are shown and compared with those from commercial systems. Future system improvements in process or in planning are discussed.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The ultrastructural changes that occurred in CaD2 mouse mammary carcinoma at 1, 24, and 96 h after photodynamic therapy (PDT) with meso-tetra(m-hydroxyphenyl)porphyrin (m- THPP, 5 mg/kg b.w.) or its corresponding chlorin (m-THPC, 1 mg/kg b.w.) were investigated. The destruction of the tumors occurred at a faster rate and was more severe by m-THPC-PDT than m-THPP-PDT, although the dose of m-THPC used was 5 times lower than that of m-THPP. The ultrastructral alterations of the tumors after PDT with m-THPP or m-THPC were qualitatively similar: direct damage to both microvasculature and neoplastic cells of the tumors.

An ordinary fluorescence spectrometer equipped with a dichroic mirror and fiber optics can be used to measure sensitizer fluorescence in tumors and normal tissues. Our findings with such an instrument showed that after oral administration of 60 mg/kg 5-aminolevulinic acid (ALA) mucosas and rectal adenomas fluoresced stronger than normal skin. Also basal cell carcinomas (BCCs) showed a stronger porphyrin fluorescence than skin after topical application of ALA. The porphyrin fluorescence of BCCs decayed rapidly during standard laser irradiation at 630 nm. The degradation rate of porphyrins in the tumor was approximately constant down to at least 0.3 mm below the tumor surface, in agreement with an optical penetration depth of more than 1 mm.

Seven hundred sixty three basal cell carcinomas (BCCs) in 122 patients were treated by photodynamic therapy by 5-aminolevulinic acid (ALA) in cream topically applied, either alone, in combination with dimethyl sulphoxide (DMSO) and ethylenediaminetetraacetic acid disodium salt (EDTA), or with DMSO as a pretreatment. After 3 hours cream exposure 40 - 200 Joules/cm2 of 630 nm laser light was given. Fluorescence imaging of biopsies showed highly improved ALA penetration depth and doubled ALA-induced porphyrin production using DMSO/EDTA. Treatment response was recorded after 3 months. After a single treatment 90% of 393 superficial lesions responded completely, independent of using DMSO/EDTA. In 363 nodulo-ulcerative lesions the complete response rate increased from 67% to above 90% with DMSO/EDTA for lesions less than 2 mm thickness and from 34% to about 50% for lesions thicker than 2 mm. Recurrence rate observed during a follow-up period longer than 12 months was 2 - 5%. PDT of superficial thin BCCs with ALA-induced porphyrins and DMSO/EDTA equals surgery and radiotherapy with respect to cure rate and recurrence. Cosmetic results of ALA-based PDT seemed to be better than those after other therapies. In patients with the nevoid BCC syndrome the complete response rate after PDT was far lower.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Nine patients with malignant pleural mesothelioma underwent extensive surgery followed by intra-operative photodynamic therapy. Two mg/kg Photofrin was given 48 hours prior to surgery. The thoracic cavity and eventual remaining lung were exposed to 15 - 30 Joules/cm2 of 630 nm laser light. Tumor tissue was analyzed by microscopic photometrical techniques. Five patients with mixed or epithelioid tumors with fluorescence intensity > 100 gray level/pixel seemed to benefit from the given therapy. One patient was free of disease 18 months after treatment. Two patients were treated for metastasis after 12 months with no sign of intrathoracic recurrence. Both are still alive, one without further sign of disease 32 months after initial treatment. Two patients presented generalized disease after 9 and 13 months and intrathoracic recurrence several months later. Two patients with poorly differentiated tumors and 2 patients with moderate to highly differentiated tumors, but with fluorescence intensity < 100 gray level/pixel, presented recurrences after 4 months. PDT-efficiency seems to be predicted by the intensity and distribution of drug-induced fluorescence in tumor tissue. PDT may enhance the possibility to achieve complete local tumor control after excision. Multimodal therapeutic approach of local and systemic disease seems mandatory to further improve survival.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In this paper, modulation transfer function and image noise measurements are presented for Kinestatic Charge Detectors employing high-pressure Kr gas doped with NH3 and CO2. Kr improves spatial resolution over Xe because, at equal x-ray mean free path, it has both reduced fluorescence reabsorption and reduced electron range. NH3 eliminates mobility dispersion (disparate ionic mobilities from multiple charge carriers) caused by gas impurities. CO2 reduces electron attachment and thus ion-ion recombination because it lowers the electron temperature, thereby increasing electron drift velocity via the Ramsauer effect.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The effect of sulfonations on the PDT efficiency of aluminum phthalocyanines and meso- tetraphenylporphines was studied in the CaD2 mouse mammary carcinoma. The PDT efficiencies were found to decrease in the following order: AlPCS2 > AlPCS4 > Photofrin > TPPS2a > AlPCS1 > TPPS4 > TPPS2o > TPPS1. Apparently, the degree of sulfonations of both families of dyes strongly affects the photobiological properties. It was found to be of great importance whether the sulfonate groups were located adjacently or opposite positions on the molecules.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Photodynamic therapy has been used for treatment of malignant cutaneous lesions. Photosensitizer has been topically applied, 5-aminolevulinic acid, with light delivered at 630 nm. A study of response rate to varying light doses was performed, it might seem that light doses of 40 - 50 J/cm2 is sufficient for superficial lesions. For nodular lesions higher light doses are needed. Some patients with tumors in the gastrointestinal tract have been treated with systemic administration of 5-aminolevulinic acid and re-treated with Photofrin in case of unsatisfactory results. From the preliminary material available 5-aminolevulinic acid seems less promising as a photosensitizer for internal lesions compared to dermal lesions.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

By using confocal laser scanning microscopy (CLSM), intracellular and intratumoral fluorescence localization of several promising photosensitizing fluorophores, such as the derivatives of sulfonated aluminum phthalocyanines (AlPCS n , n equals 1-4), meso- tetra(hydroxyphenyl)porphine (m-THPP) and its chlorin (m-THPC) was studied in several cancer cell lines in vitro and in tumor models in vivo. The correlation of the subcellular and intratumoral localization patterns of the potent photosensitizers with the targets of photodynamic action is discussed. Also, the advantages of using CLSM for studying the fluorescence properties of the photosensitizing fluorochromes in a biological system is emphasized.