Raffinose family oligosaccharides (RFOs) are non-structural, water-soluble carbohydrates widely distributed in the plant kingdom, and include the trisaccharide raffinose, the tetrasaccharide stachyose and the pentasaccharide verbascose. RFOs have been suggested to play a major role in storing carbohydrates in seeds and vegetative tissues, and in conferring osmoprotection against abiotic stresses, such as high salinity and drought. However, the high polarity nature of RFOs makes their analysis with typical reversed phase liquid chromatography (RP-LC) generally difficult, with these compounds eluting very close to the void volume with minimal retention. Moreover, carbohydrate-related compounds lack an inherent chromophore in the ultraviolet-visible (UV) region to make them suitable for UV detection. To overcome these issues, alternative analytical methods based on LC coupled to mass spectrometry (MS) have been developed and porous graphitic carbon (PGC) stationary phases described in the literature as good alternative to typical RP columns for retaining these highly polar compounds were used. In addition, PGC stationary phases allow the use of MS-compatible mobile phases for efficient on-line coupling with electrospray ionization (ESI), and when coupled to tandem MS (MSn) techniques, powerful structural information can be obtained. The present work focuses on the application of a PGC-ESI-QIT-MSn method for the quantitative analysis of RFOs in Casuariana glauca plant tissues under salt stress conditions. In addition, we describe the structural characterization of RFOs through collision induced dissociation (CID) and MSn experiments using a quadrupole ion trap mass spectrometer (QIT-MS) in the ESI positive ion mode.
This randomized controlled trial examined serum and macular (in vivo measured macular pigment optical density [MPOD]) responses to supplemental lutein and zeaxanthin in Chinese subjects with early age-related macular degeneration.One hundred and eight patients with early age-related macular degeneration older than 50 y were randomized to low lutein (LL; 10 mg/d), high lutein (HL; 20 mg/d), lutein plus zeaxanthin (LZ; each 10 mg/d), or placebo during a 48-wk intervention. Serum concentrations were quantified by C30 high-performance liquid chromatography (at baseline and 4, 12, 24, and 48 wk), and MPOD was measured by analysis of autofluorescence images (at baseline and 24 and 48 wk).Serum lutein levels in the LL, LZ, and HL groups increased significantly in the first 4 wk and then increased 4.24-, 4.66-, and 6.23-fold during the trial, respectively (all P < 0.001). The serum lutein level in the HL group was significantly higher than that in the LL or LZ group at 48 wk (P < 0.05). Similarly, the serum zeaxanthin concentration in the LZ group increased 3.11-fold at 48 wk. MPOD increased smoothly in all treated groups, and the increase from baseline was greatest in the HL group at 24 and 48 wk (both P < 0.05). MPOD and serum lutein levels increased linearly with the dosage and their increasing rates were statistically correlated (all P < 0.05). No notable changes were detected in the placebo group for MPOD and serum concentrations.Xanthophyll supplementation significantly increased serum concentrations and MPOD in patients with early age-related macular degeneration, and a higher lutein supplementation (20 mg/d) might be more effective in increasing these two biochemical markers in Chinese patients without significant side effects.
Many high-flexible structures with circular sections (chimneys, etc.) tend to be damaged by vortex-induced vibration (VIV in short). As the direct guidance of wind-resistant design of circular high structures, the wind load code is responsible for wind-induced damage. In view of so many failure cases of circular high structures, it is necessary to study the applicability of current wind load codes. In this paper, the VIV displacements of six chimneys are calculated using European (approach 1, 2), Chinese, Japanese, Canadian, and American wind load codes/recommendations, respectively, and the calculated displacements are compared with the full-scale measured results. The comparison shows that for steel chimneys, the displacements calculated by Japanese recommendation and Chinese code are about only 30% of the full-scale measured value, and those calculated by Canadian code and approach 1 of European code are about 70% of the measured value. For reinforced concrete (RC) chimneys, the calculated displacements of Chinese codes are smaller than the full-scale measured values, while the calculated values of other codes are far greater than the full-scale measured results, with the difference between them even more than ten times. On the whole, there is a significant difference between the results of the VIV displacement calculated by the wind load codes/recommendations and the actual measured value, and the calculated results of current codes/recommendations are differ from one another, thus giving rise to a contradictory phenomenon of “the same structure, but different design wind load” and making the wind-resistant design of circular high structure kind of blind. The purpose of this discussion is to clarify the objective problems of current wind load codes of circular tall structures, which can provide a reference for further research.
Disclosure of personal substance use often places people who use drugs (PWUD) at risk, both personally and professionally. Yet disclosure can positively influence governmental and organizational policies as well as improve programs meant to serve PWUD. Through numerous autobiographical conversations, six researchers and professionals in their thirties and forties who live in the Appalachian region of the United States examined what it meant for us to discuss our illicit substance use publicly. We examined the limitations of the term “lived experience” and detailed our non-problematic use. Most of us have, at times, experienced negative consequences of substance use, but these consequences are as tied to society's negative responses to substance use as to use itself. When disclosing use, we have often found that others are keen to portray PWUD as resilient, but are less willing to highlight the contributions of PWUD while they are using. We agree that making disclosure more acceptable as well as acknowledging the positive aspects of drug use would alter societal responses to use to be more effective at preventing harm. We conclude by highlighting societal and institutional policy changes that will increase the ability of PWUD to openly disclose use.
