Mechanism of strong quenching of photosystem II chlorophyll fluorescence under drought stress in a lichen, Physciella melanchla, studied by subpicosecond fluorescence spectroscopy

AbstractThe mechanism of the severe quenching of chlorophyll (Chl) fluorescence under drought stress was studied in a lichen Physciella melanchla, which contains a photobiont green alga, Trebouxia sp., using a streak camera and a reflection-mode fluorescence up-conversion system. We detected a large 0.31 ps rise of fluorescence at 715 and 740 nm in the dry lichen suggesting the rapid energy influx to the 715–740 nm bands from the shorter-wavelength Chls with a small contribution from the internal conversion from Soret bands. The fluorescence, then, decayed with time constants of 23 and 112 ps, suggesting the rapid dissipation into heat through the quencher. The result confirms the accelerated 40 ps decay of fluorescence reported in another lichen (Veerman et al., 2007 [36]) and gives a direct evidence for the rapid energy transfer from bulk Chls to the longer-wavelength quencher. We simulated the entire PS II fluorescence kinetics by a global analysis and estimated the 20.2 ns−1 or 55.0 ns−1 energy transfer rate to the quencher that is connected either to the LHC II or to the PS II core antenna. The strong quenching with the 3–12 times higher rate compared to the reported NPQ rate, suggests the operation of a new type of quenching, such as the extreme case of Chl-aggregation in LHCII or a new type of quenching in PS II core antenna in dry lichens

Visualization of pilot flame of an optically-accessible coaxially-staged aero-engine lean-burn fuel injector

[EN] The visualization of the pilot flame of a coaxially-staged aero-engine lean-burn fuel injector, not only downstream but also inside of the pilot nozzle, was successfully performed at realistic aero-engine conditions. Optical access toward the inside of the nozzle was achieved through the inner and outer shrouds, both of which were made of transparent quartz. The image distortion caused by complex contours of the two shrouds was corrected by a method based on optical ray tracing, which realized precise determination of spatial intensity distribution of optical signals. Line-of-sight OH chemiluminescence, cross-sectional OH-LIF, kerosene LIF and kerosene Mie scattering were employed as diagnostic tools. The effects of pilot local air-to-fuel ratio on spray flame structure were revealed, both inside and downstream of the pilot nozzle under stable combustions. As the pilot mixture got rich, the main reaction zone moved from inside of the pilot nozzle to the region near the injector lip downstream of the injector exit. The OH-LIF signal was detected near the central axis surrounded by the fuel spray. It was also observed near the back-step of the pilot nozzle for the rich cases. The experiments under combustion oscillation were also conducted and the correlation of phenomena inside and downstream of the pilot nozzle was captured. It was clarified that the reaction enhancement in the outer part of the lip vortex region was caused by the convection of rich mixture, which appeared near the pilot atomizer lip at 150~210deg earlier oscillation phase angle.Matsuura, K.; Uesaka, S.; Iwasaki, T.; Kurosawa, Y.; Yamada, H.; Yamamoto, T.; Hayashi, S. (2017). Visualization of pilot flame of an optically-accessible coaxially-staged aero-engine lean-burn fuel injector. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 855-872. https://doi.org/10.4995/ILASS2017.2017.475285587

Relationship of Chinese Tungusic ethnic minorities with Okhotsk cultural people in regard to dental metric traits

We used crown measurements to analyze the anthropological characteristics of three Tungusic tribes, Ewenki, Hezhen, and Oroqen, residing in the Amur River basin of China. Previous findings suggest that Amur River basin populations were involved in the population structure of Tungusic people. We then compared our findings with those of individuals with a north Asian ethnic background to examine the distribution of those characteristics in north Asian Mongoloids (1). The total crown area was classified as Sinodont (2). A deviation diagram showed scant differences among Hezhen, Oroqen, and Okhotsk individuals, indicating the closeness of those populations (3). Q-mode correlation coefficients and 2-dimensional expression suggested that Tungusic individuals were the Central Asia type. Hezhen and Oroqen were plotted closer to Okhotsk cultural people, and closely related. Race mixture occurred among the Baikal, then spread from Lake Baikal and Central Asia from the south in the post-Neolithic Era, and the groups gradually diffused to the lower Amur region. Therefore, it is reasonable to conclude that a different degree of miscegenation occurred between the Baikal and Central Asian regions in the area from Lake Baikal to lower Amur in accordance with the geographical features

Orally administered low-molecular weight agaro-oligosaccharides are absorbed into the plasma of healthy humans

Agaro-oligosaccharides (AOSs) are known to have biological activities, such as anti-inflammatory, anti-tumor, and anti-obesity effects. Although existing evidence suggests the presence of AOSs in peripheral tissues after oral administration, whether AOSs permeate into the blood circulation remains unknown. Thus, we hypothesized that AOSs with low-molecular weight can permeate the human gastrointestinal tract. To test this hypothesis, the time course of absorption was examined by analyzing plasma samples before and 1, 2, and 4 h after ingestion. Analysis was performed using liquid chromatography/mass spectrometry after labeling with p-aminobenzoic ethyl ester. Our results showed that the plasma concentration of agarobiose (Abi) was higher than that of agarotetraose (Ate); however, agarohexaose was not detected. Additionally, plasma levels of Abi and Ate were proportional to the dose. These results suggest that permeation efficiency is dependent on the molecular weight and that the systemic absorption of Abi via the gastrointestinal tract is better than that of Ate. These findings will contribute to a better understanding of the bioactivity of orally administered AOSs in peripheral tissues

Increased serum HO-1 in hemophagocytic syndrome and adult-onset Still's disease: use in the differential diagnosis of hyperferritinemia

Heme oxygenase-1 (HO-1), an inducible heme-degrading enzyme, is expressed by macrophages and endothelial cells in response to various stresses. Because ferritin synthesis is stimulated by Fe(2+), which is a product of heme degradation, we examined the relation between HO-1 and ferritin levels in the serum of patients with hemophagocytic syndrome (HPS), adult-onset Still's disease (ASD), and other diseases that may cause hyperferritinemia. Seven patients with HPS, 10 with ASD, 73 with other rheumatic diseases, 20 with liver diseases, 10 recipients of repeated blood transfusion because of hematological disorders, and 22 healthy volunteers were enrolled. Serum HO-1 and ferritin levels were determined by ELISA. Expression of HO-1 mRNA and protein by peripheral blood mononuclear cells (PBMCs) was determined by real-time PCR and immunocytochemical techniques, respectively. Serum levels of HO-1 were significantly higher in patients with active HPS and ASD than in the other groups (P < 0.01). HO-1 levels were not elevated in patients with other causes of hyperferritinemia but were moderately elevated in patients with dermatomyositis/polymyositis. Among patients with HPS and ASD, serum HO-1 levels correlated closely with serum ferritin levels, and the levels of both returned to normal after therapy had induced remission. Increased expression of HO-1 mRNA was confirmed in PBMCs from some patients with HPS and ASD. Hyperferritinemia correlated closely with increased serum HO-1 in patients with HPS and ASD but not other conditions, indicating that measurement of serum HO-1 and ferritin levels would be useful in the differential diagnosis of hyperferritinemia and perhaps also in monitoring disease activity in HPS and ASD

Endoscopic submucosal dissection of a minute intramucosal adenocarcinoma in Barrett\u27s esophagus.

A 73-year-old man with short segmental Barrett\u27s esophagus underwent esophagoscopy, and a slightly depressed, discolored lesion was found on the anterior wall of the lower esophagus. Under a provisional diagnosis of differentiated adenocarcinoma without local lymph node metastasis, endoscopic submucosal dissection (ESD) was carried out. En bloc resection with tumor-free lateral/basal margins was accomplished without complication. The resected area was 12 x 15 mm in size, whereas the neoplastic lesion was 4 x 4 mm. Histopathological examination confirmed intramucosal well-differentiated tubular adenocarcinoma without angiolymphatic invasion adjacent to the muscularis mucosae. Repeated esophagoscopy 6 months after ESD showed neither locally recurrent nor metachronous lesions. Considering that Barrett\u27s esophagus is a precancerous condition, one may recommend eradication of both the neoplastic and non-neoplastic lesion with using ESD.Without Figure