[Expression of LIAS and NRF2 in PBMCs from patients with silicosis and their correlation with silicosis].

Objective: To investigate the expression of lipoic acid synthase gene (LIAS) and nuclear factor-erythroid 2-related factor 2 gene (NRF2) in peripheral blood mononuclear cells (PBMCs) from patients with silicosis and their correlation with silicosis. Methods: A total of 45 healthy controls and 107 patients with silicosis were randomly selected in this study in May 2019. PBMCs were isolated from peripheral blood and NRF2 protein expression was detected by immunofluorescence. The mRNA levels of LIAS and NRF2 in PBMCs were determined by real-time PCR. The dose-response relationship beween LIAS and NRF2 mRNA expression levels and their association with silicosis were analyzed by restricted cubic spline (RCS) and logistic regression. Results: Compared with the control group, the number of monocytes in the case group was significantly increased, and the forced expiratory volume in the first second (FEV(1.0)) decreased, the difference was statistically significant (P<0.05) . The positive expression rate of NRF2 in PBMCs of silicosis patients in stage Ⅰ group was significantly higher than that in the control group, and the positive expression rate of NRF2 in silicosis patients in stageⅡ and Ⅲ groups was lower than that in silicosis patients in control group and stage Ⅰ group (P<0.01) . Results of RCS showed that there was a linear dose-response relationship between LIAS and NRF2 mRNA expression (overall correlation test, χ(2)=213.710, P<0.01; non-linear test, χ(2)=1.340, P=0.511) . There was a positive correlation between mRNA expression of LIAS and that of NRF2 (r=0.651, P<0.01) . The results of multivariate analysis showed that LIAS and NRF2 were increased the risk of incidence in silicosis patients with stageⅠ (OR=11.184, 4.332, P<0.05) and NRF2 was the protective factor in silicosis patients with stage Ⅱ and Ⅲ (OR=0.225, 0.208, P<0.05) after adjusting for potential confounding factors including age, education level, BMI and smoking. Conclusion: There is a linear dose-response relationship between the expression of LIAS and NRF2 mRNA in PBMCs of silicosis patients, LIAS and NRF2 are involved in the pathogenesis of silicosis.

Molecular cloning and differential expression of the glucocorticoid receptorgene in the estuarine tapertail anchovy Coilia nasus.

To understand the regulation of the glucocorticoid receptor gene (Gcr) during loading and transport stress in fish, the Gcr gene of Coilia nasus was cloned. Gcr in C. nasus is expressed strongly in the liver and muscle, and less stronglyin the gills, brain, spleen, intestine, trunk kidney, and head kidney. Gcr expression in both the liver and muscle was increased by loading and transport stress. NaCl reduced the death rate caused by loading and transport stress, and the expression of Gcr in liver and muscle differed significantly between the NaCl and non-NaCl groups. To investigate whether the elevated Gcr transcripts were translated into protein, proteins extracted from the liver and muscle were analyzed. In both tissues, C. nasus GCR protein expression patterns paralleled those of Gcr mRNA during stress.

[Research advances on the mechanism of nerve regeneration-related protein in skin fibrosis].

The healing process after skin injury is a dynamic process of interaction between various cells, cytokines, and extracellular matrix. Fibrosis is one of the main ways of skin injury repair. The process of fibrosis involves the regulation of many factors. Studies have shown that nerve regeneration-related protein (NREP) plays a key role in the fibrosis of skin tissue and organs. Based on the mechanism of skin fibrosis, this paper discusses the construction of tertiary structure of NREP, summarizes the effects of NREP and different cells in the skin on skin fibrosis and the research progress of mechanism of NREP in skin fibrosis, thus providing new ideas for the treatment of skin fibrosis diseases.

MiR-34a affects G2 arrest in prostate cancer PC3 cells via Wnt pathway and inhibits cell growth and migration.

OBJECTIVE: To investigate the effect and mechanism of miRNA-34a overexpression on proliferation and migration of PC3 prostate cancer cells. PATIENTS AND METHODS: Benign prostatic hyperplasia tissue (30 cases), prostate cancer tissue (30 cases), and prostate paracancerous tissue (30 cases) were collected. Levels of miRNA-34a in these fresh tissues were measured by fluorescence quantitative PCR. PC3 cells were divided into non-loaded group and overexpression group. Cells in the non-loaded group were transfected with non-loaded plasmid. Cells in the overexpression group were transfected with miRNA-34a plasmid, and the miRNA-34a level was determined by fluorescence quantitative PCR to confirm the overexpression. Cell proliferation was analyzed by CCK-8 assay. Cell migration rate was measured by cell scratch assay. Flow cytometry was used to detect apoptosis and analyze cell cycle. Western blot was used to measure the expression levels of ß-catenin, E-cadherin and Vimentin. RESULTS: The expression level of miRNA-34a in prostate cancer tissue was significantly lower than that in prostate paracancerous tissue. Dual-Luciferase reporter gene assay was used to analyze the transcriptional activity of Wnt1 gene. The proliferation and migration of PC3 cells were significantly decreased after overexpression of miRNA-34a, and the differences were statistically significant compared with those in the non-loaded group (p<0.05). Flow cytometry analysis showed that in the overexpression group, the apoptotic rate, as well as the proportion of cells in the G2 phase, was significantly higher than that in the non-loaded group (p<0.05). The ß-catenin level in the nucleus of PC3 cells was significantly reduced after overexpression of miRNA-34a. The total protein levels of ß-catenin and Vimentin were significantly decreased, whereas the level of E-cadherin in the overexpression group was apparently increased, compared with that in the non-loaded group. The Dual-Luciferase reporter gene showed a decrease in the relative fluorescence intensity of Wnt1 after overexpression of miR-34a (p<0.05). CONCLUSIONS: Overexpression of miRNA-34a inhibits Wnt/ß-catenin pathway by regulating the transcriptional activity of Wnt1, thereby regulating the proliferation and migration of PC3 cells and promoting apoptosis.

[Research on feasibility of in vitro inflammatory wound microenvironment simulated by using inflammatory wound tissue homogenate of mice].

Objective: To investigate the feasibility of in vitro inflammatory wound microenvironment simulated by using inflammatory wound tissue homogenate of mice. Methods: (1) Ten eight-week-old C57BL/6 male mice were collected and full-thickness skin tissue with diameter of 1.0 cm on both sides of the midline of the back was taken with a perforator to make the normal skin tissue homogenate supernatant. At 48 h after the full-thickness skin defect wound was established, the wound tissue within 2 mm from the wound edge was taken to make inflammatory wound tissue homogenate supernatant. Two kinds of tissue homogenate supernatant were taken to adjust the total protein concentration to 1 mg/mL, and the tumor necrosis factor α (TNF-α) content was detected by enzyme-linked immunosorbent assay. The number of sample was 6. (2) The primary passage of human umbilical cord mesenchymal stem cells (hUCMSCs) were collected and cultured to the 3rd passage with the normal exosomes being extracted from the hUCMSCs after cultured for 48 h. Another batch of hUCMSCs in the 3rd passage was collected and stimulated with inflammatory wound tissue homogenate supernatant of 30, 50, and 100 µg/mL total protein and normal skin tissue homogenate supernatant of 30, 50, and 100 µg/mL total protein, respectively. After cultured for 48 h, the exosomes stimulated with normal protein of 30, 50, and 100 µg/mL and exosomes stimulated with inflammatory protein of 30, 50, and 100 µg/mL were extracted. Normal exosomes, exosomes stimulated with 30 µg/mL normal protein, and exosomes stimulated with 30 µg/mL inflammatory protein were collected, the morphology was observed by transmission electron microscope, the particle size was detected by nanoparticle tracking analyzer, and the expressions of CD9 and CD63 were detected by Western blotting. (3) Twenty one-day-old C57BL/6 mice were taken to isolate the primary passage of fibroblasts (Fbs) and the 3rd passage of Fbs, whose morphology was observed under the inverted phase contrast microscope. The Fbs of 3rd passage were collected to observe the expression of vimentin by cell crawling method combined with immunofluorescence method at culture hour (CH) 2. (4) The Fbs of 3rd passage were divided into control group, normal exosome group, 30, 50, 100 µg/mL normal protein stimulating exosome group, and 30, 50, 100 µg/mL inflammatory protein stimulating exosome group according to the random number table, with 4 wells in each group. Cells in control group received no treatment, and cells in the other 7 groups were respectively added with normal exosomes, exosomes stimulated with normal protein of 30, 50, and 100 µg/mL, and exosomes stimulated with inflammatory protein of 30, 50, and 100 µg/mL prepared in experiment (2). The final mass concentration of exosomes was adjusted to 10 µg/mL. The cell viability was detected by cell count kit 8 at CH 48. (5) Two batches of Fbs in the 3rd passage were divided and treated as those in experiment (4), with 4 wells in each group, and the final mass concentration of exosomes was adjusted to 1 and 10 µg/mL, respectively. The cell mobility was detected by cell scratch test at CH 6, 12, and 24. (6) Two batches of the Fbs of 3rd passage were collected, divided, and treated as those in experiment (4) except with no control group, with 3 wells in each group, and the final mass concentration of exosomes was respectively adjusted to 1 and 10 µg/mL. The mRNA expression levels of transforming growth factor ß(1) (TGF-ß(1)), TGF-ß(3), and α smooth muscle actin (α-SMA) were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction at CH 48. Data were statistically analyzed with analysis of variance for repeated measurement, one-way analysis of variance, and Bonferroni method. Results: (1) The content of TNF-α in inflammatory wound tissue homogenate supernatant of mice was (116±3) pg/mL, significantly higher than (97±5) pg/mL in normal skin tissue homogenate supernatant at post injury hour 48 (t=3.306, P<0.05). (2) Normal exosomes, exosomes stimulated with 30 µg/mL normal protein, and exosomes stimulated with 30 µg/mL inflammatory protein of hUCMSCs showed the typical saucer-like shape. The particle sizes of the three exosomes of hUCMSCs were 30-150 nm, which were all within the normal particle size range of exosome. Three exosomes of hUCMSCs positively expressed CD9 and CD63. (3) The primary passage of cells were clearly defined and showed protruding spindle shape, irregular polygon shape, or slender strip shape. The morphology of the 3rd and the primary passage of cells is similar. At CH 2, vimentin in cells was positively expressed, and the cells were identified as Fbs. (4) At CH 48, the cell viability was (137.4±2.8)% in 30 µg/mL inflammatory protein stimulating exosome group, obviously higher than 100%, (107.5±2.4)%, (113.3±3.2)%, (104.0±2.0)%, and (101.9±1.5)% in control group, normal exosome group, 30 µg/mL normal protein stimulating exosome group, and 50 and 100 µg/mL inflammatory protein stimulating exosome groups, respectively (P<0.01), and cell viability in 30 µg/mL normal protein stimulating exosome group was obviously higher than that in control group, normal exosome group, and 50 and 100 µg/mL normal protein stimulating exosome groups [(103.4±2.2)% and (102.5±1.4)%], respectively (P<0.01). (5) At CH 6, 12, and 24, the mobility rate of cells in 30 µg/mL inflammatory protein stimulating exosome group was significantly higher than that in control group, normal exosome group, 30 µg/mL normal protein stimulating exosome group, and 50 and 100 µg/mL inflammatory protein stimulating exosome groups, respectively, when the final mass concentrations of exosome was 1 µg/mL (P<0.05) . At CH 12, the mobility rate of cells in 30 µg/mL normal protein stimulating exosome group was obviously higher than that in control group, normal exosome group, and 50 and 100 µg/mL normal protein stimulating exosome groups, respectively, when the final mass concentration of exosome was 1 µg/mL (P<0.05). At CH 6, the mobility rate of cells in 30 µg/mL inflammatory protein stimulating exosome group was significantly higher than that in control group and normal exosome group (P<0.05), and the mobility rate of cells in 30 µg/mL normal protein stimulating exosome group was significantly higher than that in 50 and 100 µg/mL normal protein stimulating exosome groups, respectively, when the final mass concentration of exosome was 10 µg/mL (P<0.05). At CH 12 and 24, the mobility rate of cells in 30 µg/mL inflammatory protein stimulating exosome group was significantly higher than that in control group, normal exosome group, and 50 and 100 µg/mL inflammatory protein stimulating exosome groups (P<0.05), and the mobility rate of cells in 30 µg/mL normal protein stimulating exosome group was significantly higher than that in control group, normal exosome group, and 50 and 100 µg/mL normal protein stimulating exosome groups, respectively, when the final mass concentration of exosome was 10 µg/mL (P<0.05). (6) There were no statistically significant differences in mRNA expression levels of TGF-ß(1), TGF-ß(3), and α-SMA of cells among the 7 groups at CH 48 when the final mass concentration of exosome was 1 µg/mL (F=1.123, 1.537, 1.653, P>0.05). There were no statistically significant differences in mRNA expression levels of TGF-ß(1) and α-SMA of cells among the 7 groups at CH 48 when the final mass concentration of exosome was 10 µg/mL (F=1.487, 1.308, P>0.05), and mRNA expression level of TGF-ß(3) of cells in 50 µg/mL inflammatory protein stimulating exosome group at CH 48 was significantly higher than that in normal exosome group, 50 µg/mL normal protein stimulating exosome group, and 30 and 100 µg/mL inflammatory protein stimulating exosome groups when the final mass concentration of exosome was 10 µg/mL (P<0.05). Conclusions: The pretreatment with inflammatory wound tissue homogenate supernatant of mice has no significant effect on the total protein of hUCMSCs exosomes. The hUCMSCs exosomes stimulated by low concentration inflammatory wound tissue homogenate supernatant can significantly promote the proliferation and migration ability of Fbs. The content of inflammatory mediators in the wound tissue homogenate supernatant during the inflammatory phase is extremely low, which may be the reason that the anti-inflammation and tissue repair paracrine effects of mesenchymal stem cell cannot be effectively started.

[Advances in the research of effects of epithelial-mesenchymal interaction on wound healing and scar formation].

Wound healing is a dynamic process which involves interaction of various types of cells, cytokines, and extracellular matrix. Among them, epithelial cells and mesenchymal cells are the key components which involve in wound healing and scar formation. Related scholars had done a great number of studies about the functions of epithelial cells and fibroblasts(Fbs) in wound healing and scar formation. The results showed that under the stimulation of complex microenvironment, epithelial cells would lose their epithelial characteristics and acquire the typical characteristics and migration ability of mesenchymal cells. At the same time, with the complex changes of cell structure and cell behavior, they would participate in the process of tissue wound repair, including normal or fibrotic repair, by covering the wound with migration. Fbs are the key cells for the wound fibrotic repair, and play important roles in the process of wound healing, including excessive wound healing or delayed wound healing. In the recent years, the researchers realized that the cross-talk between epithelial cells and Fbs in wound healing, which is referred to as epithelial-mesenchymal interaction, significantly changes the biological behaviors of these two cell types, which affects the dermal remodeling and re-epithelialization quality of wound. Epithelial-mesenchymal interaction plays an important role in skin morphogenesis during embryonic development and maintaining the structural integrity of adult skin. In the process of re-epithelialization, Fbs could promote the proliferation and migration of keratinocytes, meanwhile keratinocytes would receive the signals from Fbs to reconstruct functional epithelium, which has become a hot topic in the field of wound healing at present. In this paper, a comprehensive analysis of the literature on the role of epithelial-mesenchymal interaction in wound healing and scar formation at home and abroad in recent years is presented for the reference of relevant scholars.

[Influence of human amniotic mesenchymal stem cells on macrophage phenotypes and inflammatory factors in full-thickness skin wounds of mice].

Objective: To explore the influence of human amniotic mesenchymal stem cells (hAMSCs) on the in vivo and in vitro regulation of macrophage phenotypes and inflammatory factors associated with wound healing of full-thickness skin wounds in mice. Methods: Fresh amniotic membrane discarded from full-term delivery by 5 healthy pregnant women in the Department of Obstetrics and Gynecology of the Affiliated Hospital of Zunyi Medical University was used for the isolation and culture of hAMSCs by enzyme digestion method. The third passage of cells was used for identification of adipogenic and osteogenic differentiation. The fourth passage of cells was used for identification of hAMSCs surface markers. Ten C57BL/6 mice (all male, aged 6 to 8 weeks, the same gender and age below) were selected for extracting mouse peritoneal macrophages by intraperitoneal lavage, and M1-type macrophages were induced by Dulbecco's modified eagle medium (DMEM) medium containing interferon-γ. The M1-type macrophages were divided into hAMSCs+ macrophage group and macrophage alone group. Then 1×10(4) hAMSCs/per well of fourth passage were added to macrophage in hAMSCs+ macrophage group and cultured in 2 mL DMEM medium for routine culture. In macrophage alone group, each well was only added with 2 mL DMEM medium for routine culture. On day 1 and 7 in culture, the content of interleukin-12 (IL-12), arginase 1, and IL-10 in the cell culture supernatant of the 2 groups were detected by enzyme-linked immunosorbent assay with sample number of 6/per group. (2) Full-thickness skin wound model was reproduced in the back of 56 C57BL/6 mice, which were divided into hAMSCs group and phosphate buffer solution (PBS) group using the random number table, with 28 mice in each group. Mice in hAMSCs group were subcutaneously injected with 100 µL of cell suspension containing 1×10(7) hAMSCs per mL in PBS suspension along the wound edge. While mice in PBS group were only subcutaneously injected with 100 µL PBS along the wound edge. On post injection day (PID) 1, 3, 7, and 14, 7 mice in the two groups were sacrificed respectively. Histopathological observation was performed with hematoxylin-eosin staining. The expressions of macrophage surface markers [CD68 and inducible nitric oxide synthase (iNOS) double positive cells and CD68 and arginase 1 double positive] in the wounds were detected by immunofluorescent staining. The mRNA expressions of IL-10, macrophage inflammatory protein 1α (MIP-1α), and MIP-2 in the wounds were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were statistically analyzed with analysis of variance for factorial design, t test, and Bonferroni correction. Results: (1) On day 1 in culture, the content of IL-12 and arginase 1 in the cell culture supernatant of the two groups were similar (t=0.448, 0.536, P>0.05), and the content of IL-10 in the cell culture supernatant of hAMSCs+ macrophage group was significantly lower than that in macrophage alone group (t=14.722, P<0.01). On day 7 in culture, the content of IL-12 in the cell culture supernatant of hAMSCs+ macrophage group was significantly lower than that in macrophage alone group (t=13.226, P<0.01), and the content of arginase 1 and IL-10 was significantly higher than that in macrophage alone group (t=30.172, 31.406, P<0.01). (2) On PID 1, a large number of inflammatory cells infiltration were observed in the skin wounds of both groups. On PID 3, the inflammatory cells infiltration in the skin wounds increased in both groups, and the inflammatory cells infiltration in hAMSCs group was less than that in the PBS group. On PID 7, the inflammatory cells infiltration in the wounds decreased in both groups, and the inflammatory cells infiltration in hAMSCs group was less than that in the PBS group. On PID 14, no obvious inflammatory cells infiltration was observed in the wounds in the two groups. (3) On PID 1 and 14, the percentages of CD68 and iNOS double positive cells and CD68 and arginase 1 double positive cells in the wounds were similar in the two groups (t(1 d)=0.134, 0.693, t(14 d)=1.146, 2.585, P>0.05). On PID 3 and 7, the percentages of CD68 and iNOS double positive cells in the wounds in hAMSCs group were significantly lower than those of PBS group (t=6.396, 4.787, P<0.01), while the percentages of CD68 and arginase 1 double positive cells were significantly higher than those of PBS group (t=3.928, 4.473, P<0.01). (4) On PID 1, the mRNA expressions of IL-10 in the wounds of mice in the two groups were similar (t=2.005, P>0.05). On PID 3, 7, and 14, the mRNA expressions of IL-10 in the wounds of mice in hAMSCs group were significantly higher than those of PBS group (t=7.758, 124.355, 80.823, P<0.01). On PID 1, 3, 7, and 14, the mRNA expressions of MIP-1α and MIP-2 in the wounds of mice in hAMSCs group (0.341±0.212, 0.648±0.004, 0.611±0.106, 0.763±0.049, 1.377±0.099, 1.841±0.042, 1.181±0.035, 0.553±0.028) were significantly lower than those of PBS group (3.853±0.035, 6.914±0.163, 3.648±0.113, 2.250±0.046, 11.119±0.495, 8.634±0.092, 5.722±0.021, 4.862±0.036, t=43.198, 101.904, 51.845, 58.231, 51.074, 177.501, 291.752, 251.614, P<0.01). Conclusions: hAMSCs demonstrates biological effects of promoting the transformation of M1-type macrophages into M2-type macrophages in full-thickness skin wounds of mice. They can up-regulate the expression of anti-inflammatory and anti-fibrotic factor IL-10, and down-regulate the expression of important inflammation mediated factors MIP-1α and MIP-2.

Safety evaluation studies of SGF gum--a potential food additive from the seed of Sesbania cannabina.

SGF gum, derived from the plant Sesbania cannabina, has properties very similar to those of guar gum. Because it is much cheaper than guar, SGF gum is of interest as a possible new food additive. It has therefore been tested in rats for acute, short-term and subchronic toxicity, teratogenicity and effects on reproductive performance, and a 1% concentration in the diet has been identified as the no-effect level. The tests complied with the guidelines issued by the Chinese authorities. Mutagenicity studies, Ames tests and a micronucleus test gave negative results, and a dominant lethal test in mice was negative at the 1% dietary level, although at 5 and 10% the results were equivocal. No adverse changes were elicited in 23 human volunteers who consumed a total of 960 mg SGF gum during a 30-day period during which they consumed, daily, 80 g ice-cream containing 0.04% SGF gum instead of the usual thickener. On the basis of applying a 100-fold safety factor to the findings in the animal studies, an acceptable human daily intake of 6 mg/kg is suggested.

[Clinical study on tongxinluo capsule in treatment of patients with angina pectoris caused by coronary heart disease].

OBJECTIVE: To observe the effects of Tongxinluo capsule (TXLC) in treating angina pectoris (AP) caused by coronary heart disease (CHD) and evaluate its safety. METHODS: Randomized single-blind controlled design were adopted. Three hundred and forty two patients were treated with TXLC (4 capsules, three times daily), and 150 patients in the control group done with Shuxin oral liquor (SXOL, 20 ml, two times daily). After 4 weeks of treatment, the data of AP, ECG, main symptoms, total effects were collected and evaluated. RESULTS: TXLC appeared to be more effective than SXOL for patients with mild, moderate, severe AP (P < 0.01), except with mild stomach discomfort for a few patients, TXLC has no side effect and toxicity. CONCLUSION: TXLC is an effective drug in treating AP and has no side effects and toxicity.

[Antiarrhythmic effects of Cordyceps sinensis (Berk.) Sacc].

The administration of 65% alcohol extracts of Cordyceps sinensis can counteract the arrhythmias induced by aconitine or BaCl2 in rats, and increase the tolerant dose of ouabain to produce the arrhythmias in guinea pigs. The drug can reduce the heart rate of anesthetic rats, decreasing the contractility of isolated papillary muscle or atria in guinea pigs, but showing no effect on the automatic rhythmicity and the functional refractory period of the atria.

Two-dimensional optical grating produced on a poly-p-phenylene vinylene/V(2)O(5)-gel film by ultrashort pulsed laser radiation.

A two-dimensional permanent transmission grating was formed on a novel polymer-gel composite film by ultrashort ( approximately 0.5-ps) and visible ( approximately 602-nm) pulsed laser radiation. With an arrangement of three noncoplanar coherent laser beams, we used two approaches to produce direct formation of a two-dimensional grating on the film. One approach is to expose the sample twice to different combinations of two beams, and the other is to expose the sample to three laser beams simultaneously. The diffraction patterns and the relative intensity distributions for different order diffraction of the two-dimensional gratings formed on the poly-p-phenylene vinylene/V(2)O(5)-gel films are analyzed for the different two-beam combinations and relative orientations among the three laser beams. The total diffraction efficiency for the incident probe laser beam into all the non-zero-order diffraction beams reaches 48%.

Difference of spectral superbroadening behavior in Kerr-type and non-Kerr-type liquids pumped with ultrashort laser pulses.

The spectral superbroadening behavior of forward coherent radiation from a 10-cm-long liquid-filled cell is investigated by using an ultrashort (∼0.5 ps) and intense (∼10 GW/cm(2)) laser pulse as the pump source. Five different transparent liquids (heavy water, water, carbon tetrachloride, benzene, and carbon disulfide) have been studied with a special experimental design that can distinguish the predominant contributions from the various possible mechanisms. Under the same pump condition, a very wide and symmetrical superbroadening (continuum) is observed on both the Stokes and the anti-Stokes side of the pump line for non-Kerr-type liquids such as heavy water and water, whereas only a red-shifted spectral broadening can be observed on the Stokes side for Kerr-type liquids such as carbon disulfide and benzene. For an explanation of the latter behavior, the dominant contributions from stimulated Rayleigh-Kerr and Raman-Kerr scattering are proposed.

Free electron laser induces specific immobilization of heparin on polysulfone films.

Covalent immobilization of heparin has been developed to reduce the amount of heparin administered systematically during long-term dialysis. Recently, it was doubted partially because of the complexion during immobilization process. In this study, we investigated a novel method for specific immobilization of heparin on polysulfone (PSF) via free electron laser (FEL) irradiation. Laser wavelengths of 6.18 or 6.31 microm, the typical absorption bands of carboxyl groups of heparin and aromatic rings in PSF, respectively, were chosen to irradiate the thin heparin membrane formed on PSF surfaces. The amount of heparin immobilized on PSF was measured by the toluidine blue method. The binding of heparin on PSF was analyzed by X-ray photoelectron spectroscopy (XPS). The immobilization of heparin resulted in a hydrophilic surface on which decreased platelet adhesion was observed. The efficiency differences, depending on laser wavelengths, were discussed from the point of view of structural and environmental differences of light-absorbing groups.

Two-photon absorption and optical-limiting properties of novel organic compounds.

The optical-limiting behavior and two-photon absorption properties of four novel organic compound solutions in tetrahydrofuran have been investigated. An ultrashort laser source with 0.5-ps pulse width and 602-nm wavelength was employed. The transmissivities of the various 1-cm-thick solution samples have been measured as a function of the beam intensity as well as of the solute concentration. The measured results can be fitted on the assumption that two-photon absorption is the only predominant mechanism causing the observed opticallimiting behavior. Based on the intensity-dependent transmissivity measurements, the molecular two-photon absorption coefficients for the four compounds are presented.