Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 35
Filter
1.
Sci Rep ; 14(1): 15417, 2024 07 04.
Article in English | MEDLINE | ID: mdl-38965334

ABSTRACT

Virtual reality self-counseling (VR-SC) is considered an effective approach for addressing mental health problems. Previous studies have shown the effectiveness of VR-SC using Sigmund Freud's avatar as the counselor. However, considering that virtual reality (VR) enables embodied perspective-taking of another person, VR-SC using the avatar of a person who cares about the participant (an intimate person), such as a family member or friend, is considered effective because it could create warm attitudes toward the participants themselves. In this study, 60 undergraduate and graduate students were split into three conditions: VR-SC with intimate persons, VR-SC with Freud, and a control group. The intervention effects were then compared. The results showed that VR-SC with an intimate person was the most effective in improving anxiety symptoms. These results may be attributed to accepting and affirming oneself from the perspective of the intimate person's avatar and counseling oneself. This study is significant in that it is the first to conduct VR-SC with the avatar of an intimate person and compare the effects with Freud's avatar. More importantly, it showed that the same VR-SC method could have different effects depending on the avatar of the counseling partner.


Subject(s)
Counseling , Virtual Reality , Humans , Female , Male , Counseling/methods , Adult , Anxiety/psychology , Young Adult , Avatar
2.
Nutrients ; 15(14)2023 Jul 22.
Article in English | MEDLINE | ID: mdl-37513666

ABSTRACT

Diabetic nephropathy (DN) is a major complication of diabetes. Nonalcoholic fatty liver disease (NAFLD) is common in diabetes, and liver fibrosis is a prognostic risk factor for NAFLD. The interaction between DN and liver fibrosis in NAFLD remains unclear. In 189 patients with DN and NAFLD who received an education course about diabetic nephropathy, liver fibrosis was evaluated using the fibrosis-4 (FIB-4) index. The association between the outcome of DN and changes in liver fibrosis was examined. The FIB-4 index was maintained at the baseline level in patients with improved DN, while it was increased in other patients. The ΔFIB-4 index was positively correlated with changes in albuminuria and proteinuria (ρ = 0.22, p = 0.004). In a multivariate analysis, changes in albuminuria and proteinuria were associated with the ΔFIB-4 index (p = 0.002). Patients with a progressive FIB-4 index category from baseline to 5 years showed a lower event-free survival rate after 5 years than patients with an improved FIB-4 index category (p = 0.037). The outcome of DN is associated with changes in liver fibrosis in patients with diabetes, NAFLD and DN. Developing a preventive and therapeutic approach for these conditions is required.


Subject(s)
Diabetes Mellitus , Diabetic Nephropathies , Non-alcoholic Fatty Liver Disease , Humans , Non-alcoholic Fatty Liver Disease/pathology , Diabetic Nephropathies/pathology , Albuminuria , Liver Cirrhosis/etiology , Risk Factors , Liver/pathology , Diabetes Mellitus/pathology
3.
Biochem Biophys Res Commun ; 643: 24-29, 2023 Feb 05.
Article in English | MEDLINE | ID: mdl-36586155

ABSTRACT

Recent studies revealed behaviorally defined sleep is conserved across broad species from insect to human. For evolutional analysis, it is critical to determine how homologous genes regulate the homologous function among species. Drosophila melanogaster shares numerous sleep related genes with mammals including Sik3, salt-inducible kinase 3, whose mutation caused long sleep both in mouse and fruit fly. The Drosophila rdgB (retinal degeneration B) encodes a membrane-associated phosphatidylinositol transfer protein and its mutation caused light-induced degeneration of photoreceptor cells. rdgB mutation also impaired phototransduction and olfactory behavior, indicating rdgB is involved in the normal neural transmission. Mammalian rdgB homologue, Pitpnm2 (phosphatidylinositol transfer protein membrane-associated 2) was discovered as one of SNIPPs (sleep-need index phosphoproteins), suggesting its role in sleep. Here, we show that rdgB is involved in sleep regulation in Drosophila. Pan-neuronal and mushroom body (MB) specific rdgB knockdown decreased nocturnal sleep. MB neurons play a dominant role, since the rescue of rdgB expression only in MB neurons in pan-neuronal knockdown reversed the sleep reducing effect of rdgB knockdown. These results revealed the sleep-related function of rdgB in Drosophila which may be conserved across species.


Subject(s)
Drosophila Proteins , Drosophila melanogaster , Animals , Drosophila/genetics , Drosophila melanogaster/genetics , Drosophila Proteins/genetics , Mammals , Phospholipid Transfer Proteins , Photoreceptor Cells , Protein Serine-Threonine Kinases , Sleep/genetics
5.
Psychol Res ; 86(3): 858-870, 2022 Apr.
Article in English | MEDLINE | ID: mdl-34095970

ABSTRACT

Previous findings on relationships between inhibition that is a core executive function, and trait rumination have been inconsistent. This inconsistency could be overcome by investigating the association between rumination and the two subcomponents of inhibition: response inhibition and attentional inhibition. This study examined whether and how response inhibition and attentional inhibition were related to rumination as well as worry. University students in Japan (N = 213) conducted the Go/No-Go Task and the Modified Stroop Task. They also completed self-report measures of depression, trait rumination, trait worry, stressors, and aggressive behaviors. Results indicated that response inhibition deficits were positively associated with trait rumination, and this association was mediated by increases in aggressive behaviors and interpersonal stressors. The associations between these variables remained significant even after controlling for depression level. There were no significant direct or indirect associations between attentional inhibition deficits and rumination. These results suggest that response inhibition deficits, among the subcomponents of inhibition, have an indirect positive association with rumination through interpersonal processes. Results also showed nonsignificant differences between rumination and worry in the magnitude of correlation coefficients with the two subcomponents of inhibition. Therefore, it remains unclear whether the positive association with response inhibition is unique to rumination.


Subject(s)
Attention , Inhibition, Psychological , Anxiety , Attention/physiology , Executive Function , Humans , Self Report
6.
Front Psychol ; 12: 535980, 2021.
Article in English | MEDLINE | ID: mdl-34858241

ABSTRACT

Emotional contagion is a phenomenon by which an individual's emotions directly trigger similar emotions in others. We explored the possibility that perceiving others' emotional facial expressions affect mood in people with subthreshold depression (sD). Around 49 participants were divided into the following four groups: participants with no depression (ND) presented with happy faces; ND participants presented with sad faces; sD participants presented with happy faces; and sD participants presented with sad faces. Participants were asked to answer an inventory about their emotional states before and after viewing the emotional faces to investigate the influence of emotional contagion on their mood. Regardless of depressive tendency, the groups presented with happy faces exhibited a slight increase in the happy mood score and a decrease in the sad mood score. The groups presented with sad faces exhibited an increased sad mood score and a decreased happy mood score. These results demonstrate that emotional contagion affects the mood in people with sD, as well as in individuals with ND. These results indicate that emotional contagion could relieve depressive moods in people with sD. It demonstrates the importance of the emotional facial expressions of those around people with sD such as family and friends from the viewpoint of emotional contagion.

7.
Plant Cell Physiol ; 62(3): 528-537, 2021 Jul 17.
Article in English | MEDLINE | ID: mdl-33439267

ABSTRACT

The liverwort Marchantia polymorpha possesses oil bodies in idioblastic oil body cells scattered in its thallus. Oil bodies are subcellular organelles in which specific sesquiterpenes and bisbibenzyls are accumulated. Therefore, a specialized system for the biosynthesis and accumulation of these defense compounds specifically in oil bodies has been implied. A recent study on M. polymorpha genome sequencing revealed 10 genes that shared high similarities with fungal-type terpene synthases (TPSs). Eight of these fungal-type TPS-like genes in M. polymorpha (MpFTPSL1-6, -9 and -10) are located within a 376-kb stretch on chromosome 6 and share similarities of over 94% at the nucleotide level. Therefore, these genes have likely originated from recent gene duplication events. The expression of a subset of MpFTPSLs was induced under non-axenic growth on vermiculite, which increased the amounts of sesquiterpenes and number of oil bodies. The tdTomato fluorescent protein-based in-fusion reporter assay with MpFTPSL2 promoter revealed fluorescent signals specifically in oil body cells of the thallus, indicating that MpFTPSL2 functions in oil body cells. Recombinant MpFTPSL2 expression in Escherichia coli led to sesquiterpene synthesis from farnesyl pyrophosphate. Moreover, suppression of a subset of MpFTPSLs through RNA interference reduced sesquiterpene accumulation in thalli grown on vermiculite. Taken together, these results suggest that at least a subset of MpFTPSLs is involved in sesquiterpene synthesis in oil body cells.


Subject(s)
Alkyl and Aryl Transferases/metabolism , Lipid Droplets/metabolism , Marchantia/metabolism , Plant Proteins/metabolism , Sesquiterpenes/metabolism , Alkyl and Aryl Transferases/genetics , Genes, Plant/genetics , Marchantia/cytology , Marchantia/enzymology , Marchantia/genetics , Plant Proteins/genetics
8.
Scand J Psychol ; 62(2): 118-124, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33011995

ABSTRACT

Young, Sutherland, and McCoy indicated that a Go/No-Go Task (GNG) becomes more difficult as the inter-stimulus intervals (ISIs) becomes shorter. However, is the number of commission errors under extremely short ISIs a useful metric for assessing response inhibition? This study challenges the assumption that a shorter ISI in the GNG enables better assessment of response inhibition. University students (N = 213) completed the GNG, the Conners Continuous Performance Test 3rd Edition (CCPT), and the Modified Stroop Task. The GNG comprised four blocks of 400, 600, 800, and 1000 ms ISIs, whereas the stimulus presentation was fixed at 250 ms. Consistent with Young et al., shorter ISIs in the GNG resulted in more commission errors. In the block with the shortest ISI, participants also failed more frequently in responses in go trials than in the other blocks, which appears to increase in error variance of commission errors. Consistent with this interpretation, the association between the number of commission errors in the block with 400 ms ISI and CCPT performance was weaker than those between the number of commission errors in other blocks and CCPT performance. It is concluded that using the number of commission errors in the condition with extremely short ISIs in the GNG might be inappropriate for assessing response inhibition.


Subject(s)
Neuropsychological Tests/statistics & numerical data , Reaction Time/physiology , Adolescent , Adult , Female , Humans , Japan , Male , Stroop Test/statistics & numerical data , Students/statistics & numerical data , Time Factors , Young Adult
9.
Blood Adv ; 4(19): 4607-4617, 2020 10 13.
Article in English | MEDLINE | ID: mdl-32991720

ABSTRACT

Acute graft-versus-host disease (aGVHD) is a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Therefore, management of aGVHD is important for successful transplantation. Mucosal damage and alteration of the gut microbiota after allo-HSCT are key factors in the development of aGVHD. We conducted a prospective study to evaluate the ability of prebiotics, which can alleviate mucosal damage and manipulate the gut microbiota, to mitigate posttransplantation complications, including aGVHD. Resistant starch (RS) and a commercially available prebiotics mixture, GFO, were administered to allo-HSCT recipients from pretransplantation conditioning to day 28 after allo-HSCT. Prebiotic intake mitigated mucosal injury and reduced the incidence of all aGVHD grades combined and of aGVHD grades 2 to 4. The cumulative incidence of skin aGVHD was markedly decreased by prebiotics intake. Furthermore, the gut microbial diversity was well maintained and butyrate-producing bacterial population were preserved by prebiotics intake. In addition, the posttransplantation fecal butyrate concentration was maintained or increased more frequently in the prebiotics group. These observations indicate that prebiotic intake may be an effective strategy for preventing aGVHD in allo-HSCT, thereby improving treatment outcomes and the clinical utility of stem cell transplantation approaches. This study was registered on the University Hospital Medical Information Network (UMIN) clinical trials registry (https://www.umin.ac.jp/ctr/index.htm) as #UMIN000027563.


Subject(s)
Gastrointestinal Microbiome , Graft vs Host Disease , Hematopoietic Stem Cell Transplantation , Graft vs Host Disease/prevention & control , Humans , Prebiotics , Prospective Studies
10.
Zoolog Sci ; 36(1): 82-94, 2019 02 01.
Article in English | MEDLINE | ID: mdl-31116542

ABSTRACT

To elucidate the genetic population structure of two coastal weevils, Scepticus griseus and S. tigrinus, we conducted molecular phylogenetic analyses of the mitochondrial DNA cytochrome c oxidase subunit I (COI) region (1308 bp) and cytochrome c oxidase subunit II (COII) region (584 bp). A total of 650 individuals (S. griseus, 444 individuals; S. tigrinus, 206 individuals) were obtained from 64 sites. The haplotype networks of both species showed three major lineages with roughly regional distribution. However, the two species show quite different genetic structures; S. griseus has a complicated structure while that of S. tigrinus is simple. We hypothesize that the genetic structure of each of these two weevil species reflects climatic oscillations during the Pleistocene, and the differences in genetic structure between S. griseus and S. tigrinus may represent a unique evolutionary history scenario in each species.


Subject(s)
Weevils/classification , Weevils/genetics , Animals , Biological Evolution , Climate Change , DNA, Mitochondrial/genetics , Ecosystem , Electron Transport Complex IV/genetics , Japan , Phylogeny , Sequence Analysis, DNA
11.
Nihon Koshu Eisei Zasshi ; 64(11): 664-671, 2017.
Article in Japanese | MEDLINE | ID: mdl-29249777

ABSTRACT

Objective We examined effective exercise adherence support methods for persons experienced in the Medical Fitness (MF) program to clarify the relation of personality traits with exercise adherence and the factors that improve exercise adherence.Methods Subjects were 283 adults who had registered as members in the MF program at an affiliate of Hospital A. We implemented an anonymous self-administered questionnaire by postal mail. Using the Japanese version of the Ten Item Personality Inventory (which contains 10 items that measure the Big Five personality traits), we evaluated the following characteristics: "Extraversion", "Agreeableness", "Conscientiousness", "Neuroticism", and "Openness". The subjects who reported exercising regularly at the time of survey were considered persons with subjective exercise adherence.Results In persons with subjective exercise adherence, "Conscientiousness" was significantly lower (P=0.003) among men and "Neuroticism" was significantly higher (P=0.018) among women when compared to persons with subjective exercise adherence. There was no correlation between the things that emphasize exercise adherence and "Conscientiousness" among men. There was a negative correlation between "can achieve goal" and "Neuroticism" among women.Conclusions It is essential to consider personality and gender differences when devising exercise adherence support measures for the MF program. Our results suggest that women with high neuroticism do not need "can achieve goal" to maintain their exercise habits; therefore, it is necessary to examine teaching methods that do not focus on only goal achievement as part of exercise adherence support for MF.


Subject(s)
Patient Compliance , Personality , Physical Fitness , Adult , Female , Humans , Male , Surveys and Questionnaires
12.
Eur J Pharmacol ; 720(1-3): 363-75, 2013 Nov 15.
Article in English | MEDLINE | ID: mdl-24120658

ABSTRACT

This study aimed to pharmacologically identify and characterize α2-adrenoceptors and imidazoline (I) receptors (I1- and I2-subtype) on canine, feline, bovine, equine, murine, and leporine platelet membranes. Saturation binding studies with both (3)H-yohimbine and (3)H-clonidine showed that α2-adrenoceptors were expressed on canine, leporine, feline, and murine platelets but not on bovine and equine platelets. In competition studies, the rank order of affinity of 6 compounds for canine platelet α2-adrenoceptors was similar to that of potency at α2A-subtype reported in human platelets. Saturation binding studies in the presence of norepinephrine showed that canine, feline, bovine, and equine platelets had I1-receptors defined by (3)H-clonidine binding, but neither murine nor leporine platelets had I1-receptors; whereas, platelets of all species had I2-receptors defined by (3)H-idazoxan binding. In competition studies, more potent compounds displayed biphasic competition curves with (3)H-clonidine. The rank orders of affinity of I1 compounds for high-affinity components of I1-receptors of canine, feline, bovine, and equine platelets and I2-receptors of all species platelets were similar to those of compounds for high-affinity components reported in human I1- and I2-receptors, respectively. Guanine nucleotides inhibited the high-affinity component of naphazoline binding to canine I1-receptors, but not to I2-receptors. Furthermore, guanine nucleotides dose-dependently inhibited (3)H-clonidine binding to I1-receptors; whereas, they did not interfere with (3)H-idazoxan binding to I2-receptors, supporting the notion that Il-receptors may belong to a G protein-coupled receptor superfamily in canine platelets. Interspecific variations of platelet α2-adrenoceptor and imidazoline receptor expressions may explain different platelet responses to catecholamines and imidazoline α-adrenergic agents.


Subject(s)
Blood Platelets/metabolism , Imidazoline Receptors/metabolism , Receptors, Adrenergic, alpha-2/metabolism , Animals , Binding, Competitive , Cats , Cattle , Dogs , Female , Horses , Male , Rabbits , Radioligand Assay , Rats
13.
J Integr Plant Biol ; 55(8): 775-84, 2013 Aug.
Article in English | MEDLINE | ID: mdl-23621526

ABSTRACT

Plants produce jasmonic acid (JA) and its amino acid conjugate, jasmonoyl-L-isoleucine (JA-Ile) as major defense signals in response to wounding and herbivory. In rice (Oryza sativa), JA and JA-Ile rapidly increased after mechanical damage, and this increase was further amplified when the wounds were treated with oral secretions from generalist herbivore larvae, lawn armyworms (Spodoptera mauritia), revealing for the first time active perception mechanisms of herbivore-associated elicitor(s) in rice. In the rice genome, two OsJAR genes can conjugate JA and Ile and form JA-Ile in vitro; however, their function in herbivory-induced accumulation of JA-Ile has not been investigated. By functional characterization of TOS17 retrotransposon-tagged Osjar1 plants and their response to simulated herbivory, we show that OsJAR1 is essential for JA-Ile production in herbivore-attacked, field-grown plants. In addition, OsJAR1 was required for normal seed development in rice under field conditions. Our results suggest that OsJAR1 possesses at least two major functions in rice defense and development that cannot be complemented by the additional OsJAR2 gene function, although this gene previously showed overlapping enzyme activity in vitro.


Subject(s)
Cyclopentanes/metabolism , Herbivory , Isoleucine/analogs & derivatives , Oryza/physiology , Oxylipins/metabolism , Animals , Gene Expression Regulation, Plant , Genes, Plant , Isoleucine/biosynthesis , Retroelements , Seedlings/metabolism , Seeds/growth & development , Spodoptera
14.
Front Psychol ; 4: 57, 2013.
Article in English | MEDLINE | ID: mdl-23450824

ABSTRACT

The purpose of this study was to explore developmental changes, in terms of spectral fluctuations and temporal periodicity with Japanese- and English-learning infants. Three age groups (15, 20, and 24 months) were selected, because infants diversify phonetic inventories with age. Natural speech of the infants was recorded. We utilized a critical-band-filter bank, which simulated the frequency resolution in adults' auditory periphery. First, the correlations between the power fluctuations of the critical-band outputs represented by factor analysis were observed in order to see how the critical bands should be connected to each other, if a listener is to differentiate sounds in infants' speech. In the following analysis, we analyzed the temporal fluctuations of factor scores by calculating autocorrelations. The present analysis identified three factors as had been observed in adult speech at 24 months of age in both linguistic environments. These three factors were shifted to a higher frequency range corresponding to the smaller vocal tract size of the infants. The results suggest that the vocal tract structures of the infants had developed to become adult-like configuration by 24 months of age in both language environments. The amount of utterances with periodic nature of shorter time increased with age in both environments. This trend was clearer in the Japanese environment.

15.
J Exp Bot ; 63(14): 5223-32, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22791834

ABSTRACT

The awn, an apical extension from the lemma of the spikelet, plays important roles in seed dispersal, burial, and photosynthesis. Barley typically has long awns, but short-awn variants exist. The short awn 2 (lks2) gene, which produces awns about 50% shorter than normal, is a natural variant that is restricted to Eastern Asia. Positional cloning revealed that Lks2 encodes a SHI-family transcription factor. Allelism tests showed that lks2 is allelic to unbranched style 4 (ubs4) and breviaristatum-d (ari-d), for which the phenotypes are very short awn and sparse stigma hairs. The gene identity was validated by 25 mutant alleles with lesions in the Lks2 gene. Of these, 17 affected either or both conserved regions: the zinc-binding RING-finger motif and the IGGH domain. Lks2 is highly expressed in awns and pistils. Histological observations of longitudinal awn sections showed that the lks2 short-awn phenotype resulted from reduced cell number. Natural variants of lks2 were classified into three types, but all shared a single-nucleotide polymorphism (SNP) that causes a proline-to-leucine change at position 245 in the IGGH domain. All three lks2 natural variants were regarded as weak alleles because their awn and pistil phenotypes are mild compared with those of the 25 mutant alleles. Natural variants of lks2 found in the east of China and the Himalayas had considerably different sequences in the regions flanking the critical SNP, suggesting independent origins. The available results suggest that the lks2 allele might have a selective advantage in the adaptation of barley to high-precipitation areas of Eastern Asia.


Subject(s)
Flowers/genetics , Gene Expression Regulation, Plant , Hordeum/genetics , Plant Proteins/genetics , Transcription Factors/genetics , Amino Acid Sequence , Chromosome Mapping , Chromosome Walking , Cloning, Molecular , Flowers/anatomy & histology , Flowers/chemistry , Flowers/growth & development , Gene Expression Regulation, Developmental , Hordeum/anatomy & histology , Hordeum/chemistry , Hordeum/growth & development , Molecular Sequence Data , Phylogeny , Plant Proteins/chemistry , Real-Time Polymerase Chain Reaction , Reverse Transcriptase Polymerase Chain Reaction , Transcription Factors/chemistry
16.
Rinsho Byori ; 56(3): 221-7, 2008 Mar.
Article in Japanese | MEDLINE | ID: mdl-18411806

ABSTRACT

We have established the assay conditions of midkine (MK) measurement, the reference intervals and evaluation for clinical significance of blood MK measurement. MK is a kind of cytokines and basic protein which is a heparin-binding growth factor of various cells. The increase of MK expression suggests a prognostic value in early stage on cancers or inflammation. But significant problems in the MK measurement are alterations resulting from standing time and temperature instability after blood collection. Assay of MK was performed with solid phase human MK immunoassay recently developed sensitive enzyme linked immunosorbent method. The assay condition of MK was required to be separated immediately after blood sampling within 24 hrs at 4 degrees C or within 2 hrs at room temperature-standing. Plasma sample obtained with EDTA-2Na or citric acid-Na, and serum obtained from plain tube container showed good results. Linearity was obtained up to 1500 pg/ml and repeatability and reproducibility were within 10% as CV%. The recovery of MK was 101.1+/-3.8% with 10 specimens ranged 97-105%. Addition of interfering substances showed no effect on assay results when hemoglobin, EDTA-Na, citrate and turbidity check, but conjugated bilirubin (over 0.68 mmol/l) and gave negative errors within 10% in the assay results and heparin gave negative errors. The reference interval was 550 +/- 160 pg/ml in healthy individuals serum.


Subject(s)
Cytokines/blood , Adult , Blood Chemical Analysis/methods , Enzyme-Linked Immunosorbent Assay , Female , Humans , Male , Midkine
17.
Biol Pharm Bull ; 28(10): 2000-2, 2005 Oct.
Article in English | MEDLINE | ID: mdl-16204965

ABSTRACT

The extract of licorice (Glycyrrhiza uralensis FISHER, Leguminosae) showed CYP3A4 inhibitory activity with the IC50 value of 0.022 mg/ml. Bioassay-guided purification afforded nine compounds, 3-(p-hydroxyphenyl)propionic acid (1), isoliquiritigenin (2), (3R)-vestitol (3), licopyranocoumarin (4), 4-hydroxyguaiacol apioglucoside (5), liquiritin (6), liquiritigenin 7,4'-diglucoside (7), liquiritin apioside (8), and glucoliquiritin apioside (9). Among these compounds, 3, 7, and 5 showed potent CYP3A4 inhibitory activities with IC50 values of 3.6, 17, and 20 microM, respectively. Glycyrrhizin (10), a main constituent of licorice, however, was inactive for CYP3A4 inhibition.


Subject(s)
Cytochrome P-450 CYP3A Inhibitors , Enzyme Inhibitors/pharmacology , Glycyrrhiza/chemistry , Enzyme Inhibitors/isolation & purification , Humans
18.
Chemistry ; 11(21): 6212-20, 2005 Oct 21.
Article in English | MEDLINE | ID: mdl-16075447

ABSTRACT

A novel alpha-diketone precursor of pentacene, 6,13-dihydro-6,13-ethanopentacene-15,16-dione, was prepared and converted successfully to pentacene in 74 % yield by photolysis of the precursor in toluene: Irradiation of the diketone solution in toluene with light of 460 nm under an Ar atmosphere caused the solution to change from yellow to fluorescent orange-pink within a few minutes, after which, purple precipitates appeared. After 35 min, the solution changed to colorless and the purple precipitates were filtered to give pentacene in 74 % yield. By contrast, in the presence of oxygen, the color of the solution changed from yellow to pale yellow, and only 6,13-endoperoxide of pentacene was quantitatively obtained. The rate of the reaction upon photolysis was measured by observing the decay of n-pi* absorption of the precursor at 460 nm, and was found to be similar in both the presence and absence of oxygen. Therefore, the photoreaction of the alpha-diketone precursor seemed to occur via the singlet excited state. Because the T-T absorption of pentacene was observed upon photolysis of the precursor in the nanosecond transient absorption measurement under an Ar atmosphere, the excited triplet state of the pentacene generated singlet oxygen by sensitization, and it reacted with the ground-state pentacene to give the 6,13-endoperoxide. The alpha-diketone deposited on glass was also converted successfully to pentacene film by photoirradiation. In addition, diketone precursors of a mixture of 2,8- and 2,9-dibromopentacene and 2,6-trianthrylene were also prepared and their photoconversion was performed.

19.
Org Biomol Chem ; 3(3): 448-53, 2005 Feb 07.
Article in English | MEDLINE | ID: mdl-15678182

ABSTRACT

X-Ray analyses of free base, zinc, and nickel complexes of 2,3;7,8;12,13;17,18-tetrakis(6,13-dihydro-6,13-pentaceno)-21H,23H-porphine revealed that the porphyrin chromophores adopted a heavily-saddled conformation by interlocking of the biconcave porphyrins in the crystals containing halobenzenes as crystalline solvents, while the ring was almost flat in the crystals obtained from benzene or from chlorobenzene and isopropanol.


Subject(s)
Heterocyclic Compounds, 4 or More Rings/chemistry , Organometallic Compounds/chemistry , Porphyrins/chemistry , Crystallization , Heterocyclic Compounds, 4 or More Rings/chemical synthesis , Metals, Heavy/chemistry , Models, Molecular , Molecular Structure , Organometallic Compounds/chemical synthesis , Porosity , Stereoisomerism , X-Ray Diffraction
20.
Biochim Biophys Acta ; 1667(1): 1-6, 2004 Nov 17.
Article in English | MEDLINE | ID: mdl-15533300

ABSTRACT

We have investigated the stability of giant unilamellar vesicles (GUVs) and large unilamellar vesicles (LUVs) of lipid membranes in the liquid-ordered phase (lo phase) against a detergent, Triton X-100. We found that in the presence of high concentrations of Triton X-100, the structure of GUVs and LUVs of dipalmitoyl-PC (DPPC)/cholesterol (chol) and sphingomyelin (SM)/chol membranes in the lo phase was stable and no leakage of fluorescent probes from the vesicles occurred. We also found that ether-linked dihexadecylphosphatidylcholine (DHPC) membranes containing more than 20 mol% cholesterol were in the lo phase, and that DHPC/chol-GUV and DHPC/chol-LUV in the lo phase were stable and no leakage of internal contents occurred in the presence of Triton X-100. In contrast, octylglucoside solution could easily break these GUVs and LUVs of the lo phase membranes and induced internal contents leakage. These data indicate that GUVs and LUVs of the lo phase membranes are very valuable for practical use.


Subject(s)
Liposomes/chemistry , Octoxynol/pharmacology , Cholesterol , Permeability/drug effects , Phase Transition , Phosphatidylcholines , Sphingomyelins
SELECTION OF CITATIONS
SEARCH DETAIL
...