Fine Structure of Secondary Wall Thickening and a Role of Microtubules in Primary Xylem Cells of Poplar

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました。Secondary wall thickening and organization of the cytoplasm during development of primary xylem cells of poplar were investigated by sectioning and freeze etching technique. Microtubules usually aggregate only above the helical thickenings or bands throughout the the development of primary xylem cells but not above the areas where no secondary wall deposition occurs, and run parallel to the micronbrils within the bands. In view of their general distribution throughout cell organelles, plasmalemma particles of primary xylem cells visible by freeze etching technique are questionable to be considered as the enzyme complex involved in the synthesis and orientation of cellulose micronbrils of secondary wall. Thus, microtubules may be considered as the only organella to determine the orientation of micronbrils. A possible association of microtubules and Golgi-derived vesicles during wall thickening is assumed by the fact that the position and alignment of microtubules are closely related to those of Golgi-derived vesicles. It seems that the microtubules play a part for the incorporation of Golgi-derived vesicles .into the destined site of cell wall

The Composition of Tree Species in the Forest Buried by the Aso-4 Pyroclastic Flow : Identification of Wooden Remains Excavated from Yato Relics in Saga Prefecture

この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました

Evidence for the coexistence of two different mechanisms for the occurrence of anti-Kasha S2 (1 1Bu) fluorescence from α- ω diphenylpolyenes

Fluorescence, fluorescence excitation, and absorption spectra have been measured for diphenylpolyenes with the polyene double bond number (n) from three to seven in solvents with different polarizabilities at room temperature. These polyenes exhibit anti-Kasha S2 (1 1Bu) fluorescence beside conventional S1 (2 1Ag) fluorescence in room temperature solution. It is shown that there are two different mechanisms for occurrence of the S2 (1 1Bu) fluorescence of diphenylpolyenes. S2 fluorescence occurs through the thermal population of the S1 state for the shorter diphenylpolyenes (n = 3 and 4), while it occurs as prompt S2 fluorescence due to inefficient S2-->S1 internal conversion for the longer diphenylpolyenes (n = 6 and 7). With diphenyldecapentaene (n = 5), S2 fluorescence based on both mechanisms is observed depending on the polarizability of the solvent used. The present results provide deeper insight into the mechanism for the occurrence of anti-Kasha S2 fluorescence of polyenes

Franck-Condon analysis of the absorption and fluorescence spectra of all trans α,ω-diphenylpolyenes with one to seven polyene double bonds

Fluorescence and absorption spectra have been measured for all-trans α, ω -diphenylpolyenes with one to seven polyene double bonds in room-temperature solution, along with the fluorescence spectra of those with one to six polyene double bonds in n -alkane matrices at 77 K. All the spectral data were fitted by sums of Gaussians to treat the Franck-Condon envelopes of the measured spectra quantitatively. The Franck-Condon analyses of the spectra in the harmonic limit revealed that the displacements of the C=C and C-C stretching vibrational modes in the 2 Ag state relative to those in the ground state, 1 Ag1 (S0), increase, while those in the 1 Bu1 state show a slight decrease with the increase of the polyene chain length. It is also shown that the bandwidths of the absorption and fluorescence spectra exhibit a monotonic decrease with the increase of the chain length

Solvent-polarizability dependence of the relative 2 1Ag(S1)- and 1 1Bu(S2)-fluorescence intensities of 1,14-diphenyl-1,3,5,7,9,11,13-tetradecaheptaene

Emission, excitation, and absorption spectra of diphenyltetradecaheptaene (DP7) have been measured in solvents with different polarizabilities, together with the Raman spectrum at room temperature. DP7 exhibits dual fluorescence from the 2 1Ag(S1) and 1 1Bu(S2) states in room temperature solution. It is shown that the 2 1Ag/1 1Bu fluorescence intensity-ratio varies significantly depending on the solvent polarizability. This observation was interpreted on the basis of the coupling strength between the 2 1Ag/1 1Bu states which is determined mainly by the 2 1Ag–1 1Bu energy separation. Fitting of the spectra with sum of Gaussians reveals a significant difference in Franck–Condon envelop between the 2 1Ag and 1 1Bu fluorescence spectra, which is originating from the large difference in the C–C and C[Double Bond]C stretching mode displacements between the 2 1Ag and 1 1Bu states

The denyning of patient’s appeal for additional local anesthesia is related to post-traumatic stress disorder symptoms about dental treatment.

The aim of this study was to identify traumatic dental events that are related to post-traumatic stress disorder (PTSD) symptoms.At a dental clinic, first-time visitors were given a questionnaire that asked patients to indicate whether they felt fear in differentdental situations. Patients’ dental anxiety was assessed using the short version of the Dental Anxiety Inventory (S-DAI).Patients’ trauma from dental treatments was assessed using the Impact of Event Scale-Revised (IES-R). Scores indicated that16.5% of patients suffered from PTSD symptoms. A weak positive correlation was observed between S-DAI scores and IES-Rscores. In a logistic regression analysis, “Not being able to get an anesthetic injection despite reporting pain during treatment”had independent effects on the PTSD symptom group. Our results suggest that a past experience with a dentist who denied apatient’s appeal for additional local anesthesia is related to the patient’s PTSD symptoms about dental treatment

Periodicity of xylem growth of rubberwood (Hevea brasiliensis) grown in Malaysia

A study on the periodicity of xylem growth in rubberwood tree at a plantation at University Putra Malaysia, Serdang, Malaysia, was conducted using a dendrometer and, pinning and knife-cutting methods. From the dendrometer readings, actual radial growth showed no substantial increase during the first six months of the study period. Growth started in the seventh month (July) and continued until the end of the year, after which the tree once again entered a resting period; possibly due to wintering effects at the beginning and end of the year. These results were also supported by pinning and knife-cutting experiments where the scars from the first (January) to the fifth month (May) occurred on previous distinct rings. It can be concluded that the rubberwood studied here showed continuous growth over a year period with a resting stage at the beginning and the end of the growth cycle. This suggests that rubberwood trees produce one growth ring a year. The present study showed that pinning or knife-cutting methods coupled with dendrometer measurements are suitable for elucidating the correlation between growth rings and periodicity of xylem growth

Characterization of catalytic α-1,3-glucanase isozymes from Paenibacillus glycanilyticus FH11 by using Brevibacillus system; Essential for suppression of Streptococcus mutans biofilms

S. mutans has been implicated in the etiology of dental caries by facilizing the colonization of tooth surfaces and playing a key role in the development of the virulent dental plaque. α-1,3-Glucan, which is a key structural constituent of the biofilm matrix (dental plaque), synthesized by glucosyltransferase type B (gtfB) in the presence of ingested sucrose. α-1,3-Glucanases also called mutanases, which hydrolyze α-1,3-glucan, are classified into two families of glycoside hydrolases, fungal (type 71) and bacterial (type 87). Because of being considered to degrade α-1,3-glucan, α-1,3-glucanases have been purified and characterized from various microbial sources. However, there are few reports on S. mutans biofilm study. For the host cell expression, Brevibacillus system is an effective bacterial expression system for secretory proteins. B. choshinensis is a gram-positive bacterium and easy to handle non-sporulating bacterium, lacking extracellular protease, that has been already shown to provide a high level of recombinant protein expression. Recently, many proteins are produced from this expression system and use for medical treatment, research study (1). Therefore, in this study we attempted to use Brevibacillus expression system to express, purify, and characterize of α-1,3- glucanase. In addition, we aimed to investigate the effect of recombinant enzyme on α-1,3-glucan biofilm produced by S. mutans from the viewpoints of formation and the effect of toothpaste agent on enzyme activity. Two novel catalytic domains of α-1,3-glucanase isozyme genes were cloned from P. glycanilyticus strain FH11 and heterologously expressed in Brevibacillus system. The recombinant isozymes, in termed CatAgl-FH1 and CatAgl-FH2, were purified to homogeneity with specific activity 0.70 U/mg and 0.77 U/mg respectively. The molecular mass of catalytic domain was estimated 62 kDa by SDS-PAGE. Both recombinant enzymes exhibited the different properties. The optimal pH of CatAgl-FH1 and CatAgl-FH2 were 5.5 and 6.0, respectively. The pH stability of CatAgl-FH1 and CatAgl-FH2 were in a range of pH 4.0-11.0 and 4.5-9.0, respectively. The optimal temperature of CatAgl-FH1 and CatAgl-FH2 were 60°C and 55°C, respectively and they were stable until 60°C. Thin Layer chromatography revealed their mode of hydrolysis towards α-1,3-glucan was endo-cleavage pattern. The major products of CatAgl-FH1 were di- and trisaccharide but mainly trisaccharide was for CatAgl-FH2. Both enzymes showed high tolerance against high concentration of sodium fluoride. However, each enzyme activity on surfactants were stepped down when sodium dodecyl sulfate and benzethonium concentration were increased. Please click Additional Files below to see the full abstract