Microscopy and chemical analyses reveal flavone-based woolly fibres extrude from micron-sized holes in glandular trichomes of Dionysia tapetodes.

BACKGROUND: Dionysia tapetodes, a small cushion-forming mountainous evergreen in the Primulaceae, possesses a vast surface-covering of long silky fibres forming the characteristic "woolly" farina. This contrasts with some related Primula which instead form a fine powder. Farina is formed by specialized cellular factories, a type of glandular trichome, but the precise composition of the fibres and how it exits the cell is poorly understood. Here, using a combination of cell biology (electron and light microscopy) and analytical chemical techniques, we present the principal chemical components of the wool and its mechanism of exit from the glandular trichome. RESULTS: We show the woolly farina consists of micron-diameter fibres formed from a mixture of flavone and substituted flavone derivatives. This contrasts with the powdery farina, consisting almost entirely of flavone. The woolly farina in D. tapetodes is extruded through specific sites at the surface of the trichome's glandular head cell, characterised by a small complete gap in the plasma membrane, cell wall and cuticle and forming a tight seal between the fibre and hole. The data is consistent with formation and thread elongation occurring from within the cell. CONCLUSIONS: Our results suggest the composition of the D. tapetodes farina dictates its formation as wool rather than powder, consistent with a model of thread integrity relying on intermolecular H-bonding. Glandular trichomes produce multiple wool fibres by concentrating and maintaining their extrusion at specific sites at the cell cortex of the head cell. As the wool is extensive across the plant, there may be associated selection pressures attributed to living at high altitudes.

Impact of audiovisual biofeedback on interfraction respiratory motion reproducibility in liver cancer stereotactic body radiotherapy.

INTRODUCTION: Irregular breathing motion exacerbates uncertainties throughout a course of radiation therapy. Breathing guidance has demonstrated to improve breathing motion consistency. This was the first clinical implementation of audiovisual biofeedback (AVB) breathing guidance over a course of liver stereotactic body radiotherapy (SBRT) investigating interfraction reproducibility. METHODS: Five liver cancer patients underwent a screening procedure prior to CT sim during which patients underwent breathing conditions (i) AVB, or (ii) free breathing (FB). Whichever breathing condition was more regular was utilised for the patient's subsequent course of SBRT. Respiratory motion was obtained from the Varian respiratory position monitoring (RPM) system (Varian Medical Systems). Breathing motion reproducibility was assessed by the variance of displacement across 10 phase-based respiratory bins over each patient's course of SBRT. RESULTS: The screening procedure yielded the decision to utilise AVB for three patients and FB for two patients. Over the course of SBRT, AVB significantly improved the relative interfraction motion by 32%, from 22% displacement difference for FB patients to 15% difference for AVB patients. Further to this, AVB facilitated sub-millimetre interfraction reproducibility for two AVB patients. CONCLUSION: There was significantly less interfraction motion with AVB than FB. These findings demonstrate that AVB is potentially a valuable tool in ensuring reproducible interfraction motion.

Two new species of the genus Laena Dejean (Coleoptera: Tenebrionidae: Lagriinae) from Hong Kong.

Two new species of the genus Laena Dejean, 1821 (Coleoptera: Tenebrionidae: Lagriinae) are described from Hong Kong: Laena hongkongica sp. n. and Laena walkeri sp. n. These constitute the first record of the genus from Hong Kong, as a species previously described from nearby area Laena ovipennis Schuster, 1926, in fact originated from Zhejiang province nearby Shanghai. Both species from Hong Kong possess a wide variation in body length, which is quite unusual for this genus.

Catalogue and Bibliography of the Hong Kong Carabidae Latreille, 1802 (Coleoptera: Adephaga), with notes on the historic boundaries of Hong Kong as related to zoological collections.

A complete list of Carabidae species historically collected in Hong Kong combined with more recent records and notes on their biology is given. Notes on the historic boundaries of Hong Kong through the colonial period are given, as this is an important element relating to our understanding of the origins of historic zoological collections made in the region. Likewise a list of collectors in Hong Kong up to the outbreak of hostilities in the Second World War is given. A full bibliography of Hong Kong Carabidae is included.

First clinical implementation of audiovisual biofeedback in liver cancer stereotactic body radiation therapy.

This case report details a clinical trial's first recruited liver cancer patient who underwent a course of stereotactic body radiation therapy treatment utilising audiovisual biofeedback breathing guidance. Breathing motion results for both abdominal wall motion and tumour motion are included. Patient 1 demonstrated improved breathing motion regularity with audiovisual biofeedback. A training effect was also observed.

Review of the Chinese species of the genus Coelostoma Brullé, 1835 (Coleoptera: Hydrophilidae: Sphaeridiinae).

The Chinese species of the genus Coelostoma Brullé, 1835 are revised and diagnosed. Five new species are described: Coelostoma bifidum sp. nov. (Jiangxi, Guangdong, Hong Kong), C. hajeki sp. nov. (Guangdong, Guangxi), C. hongkongense sp. nov. (Hong Kong), C. huangi sp. nov. (Guangxi, Jiangxi), and C. gentilii sp. nov. (Xizang). Coelostoma coomani Orchymont, 1932, C. orbiculare (Fabricius, 1775) and C. vividum Orchymont, 1936 are reported for the first time from China. Coelostoma sulcatum Pu, 1963, syn. nov. is synonymized with C. stultum (Walker, 1858). Additional faunistic data from China are provided for C. phallicum Orchymont, 1940, C. vagum Orchymont, 1940, C. turnai Hebauer, 2006, C. wui Orchymont, 1940, C. stultum (Walker, 1858), C. vitalisi Orchymont, 1923, C. fallaciosum Orchymont, 1936 and C. horni (Régimbart, 1920). Coelostoma fabricii (Montrouzier, 1860) is not considered as member of Chinese fauna as all previous records are dubious and no new material was found during our study. The distribution of C. horni in China is discussed in detail, with records from Hong Kong here considered dubious. An updated identification key to the Chinese species of Coelostoma is provided.

Development of a competitive immunoassay for the determination of N-(2-hydroxyethyl)valine adducts in human haemoglobin and its application in biological monitoring.

Ethylene oxide (EO) is an important industrial compound and a directly acting mutagen. Human exposure to it can be monitored by the determination of haemoglobin (Hb) adducts. An immunoassay that quantifies the N-terminal adduct N-(2-hydroxyethyl)valine in whole blood was developed, and its potential usefulness as a tool for biologically monitoring occupational exposure demonstrated. Analytical reliability was confirmed in a comparative study with gas chromatography-mass spectrometry (range 0.040-589 nmol g(-1) Hb, correlation coefficient 0.98, n=10). The assay was configured as a competitive enzyme-linked immunosorbent assay to facilitate the rapid throughput of samples. The assay uses a whole blood matrix and has a working range of 10-10000 pmol N-(2-hydroxyethyl)valine g(-1) hB. The assay does not appear to be affected by structurally similar metabolites and has been used to determine adducts in human blood samples. The first results from potentially exposed workers indicate the assay might be a powerful tool for the routine occupational biomonitoring of EO exposure.