Bond Strength Degradation for Prestressed Steel and Carbon FRP Bars in High-Performance Self-Consolidating Concrete at Elevated Temperatures and in Fire

Novel structures are emerging utilizing high performance, self-consolidating, fibre-reinforced concrete (HPSCC) reinforced with high-strength, lightweight, and non-corroding prestressed reinforcement. One example of this is a new type of precast carbon fibre reinforced polymer (CFRP) pretensioned HPSCC panel intended as load-bearing panels for building envelopes. As for all load-bearing structural members in building applications, the performance of these members in fire must be understood before they can be used with confidence. In particular, the bond performance of CFRP prestressing reinforcement at elevated temperatures is not well known. This paper examines the fire performance of these new types of structural elements, placing particular emphasis on the bond performance of CFRP and steel wire prestressing reinforcement at elevated temperatures. The results of large-scale fire tests and transient high temperature tensile and bond-pullout tests on CFRP and steel prestressing bars embedded in HPSCC cylinders are presented and discussed to shed light on the fire performance of these structural elements

Improve the potato crop

8 pages; includes photographs. This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu

Hemisynthesis and Absolute Configuration of novel 6-pentyl-2H-pyran- 2-one derivatives from Trichoderma spp

A comparative study of the secondary metabolism of two Trichoderma spp. with that of the Thctf1 transcription factor gene null mutant of Trichoderma harzianum 34 was carried out in order to deepen our knowledge of the biosynthetic pathway and mode of action of 6-pentyl-2H-pyran-2-one (1) and its derivatives as biocontrol agents. New isolated metabolites have shed light on the detoxification mechanism of 6-pentyl-pyranone by Trichoderma spp. All new compounds were synthesized and their stereoisomer characterized. The absolute configuration of 6-[(10R,20S)-dihydroxypentyl]-2H-pyran-2-one and 6-((10S,20R)-20-propyloxiran-1-yl)-2H-pyran-2-one was determined by NMR analysis of the corresponding Mosher’s esters

Ultrafast vibrational spectroscopic Studies on the photoionization of the α-Tocopherol analogue Trolox C

The initial events after photoexcitation and photoionization of α-tocopherol (vitamin E) and the analogue Trolox C have been studied by femtosecond stimulated Raman spectroscopy, transient absorption spectroscopy and time-resolved infrared spectroscopy. Using these techniques it was possible to follow the formation and decay of the excited state, neutral and radical cation radicals and the hydrated electron that are produced under the various conditions examined. α Tocopherol and Trolox C in methanol solution appear to undergo efficient homolytic dissociation of the phenolic –OH bond to directly produce the tocopheroxyl radical. In contrast, Trolox C photochemistry in neutral aqueous solutions involves intermediate formation of a radical cation and the hydrated electron which undergo geminate recombination within 100 ps in competition with deprotonation of the radical cation. The results are discussed in relation to recently proposed mechanisms for the reaction of α-tocopherol with peroxyl radicals, which represents the best understood biological activity of this vitamin

The use of phylogeny to interpret cross-cultural patterns in plant use and guide medicinal plant discovery: an example from Pterocarpus (Leguminosae)

The study of traditional knowledge of medicinal plants has led to discoveries that have helped combat diseases and improve healthcare. However, the development of quantitative measures that can assist our quest for new medicinal plants has not greatly advanced in recent years. Phylogenetic tools have entered many scientific fields in the last two decades to provide explanatory power, but have been overlooked in ethnomedicinal studies. Several studies show that medicinal properties are not randomly distributed in plant phylogenies, suggesting that phylogeny shapes ethnobotanical use. Nevertheless, empirical studies that explicitly combine ethnobotanical and phylogenetic information are scarce.In this study, we borrowed tools from community ecology phylogenetics to quantify significance of phylogenetic signal in medicinal properties in plants and identify nodes on phylogenies with high bioscreening potential. To do this, we produced an ethnomedicinal review from extensive literature research and a multi-locus phylogenetic hypothesis for the pantropical genus Pterocarpus (Leguminosae: Papilionoideae). We demonstrate that species used to treat a certain conditions, such as malaria, are significantly phylogenetically clumped and we highlight nodes in the phylogeny that are significantly overabundant in species used to treat certain conditions. These cross-cultural patterns in ethnomedicinal usage in Pterocarpus are interpreted in the light of phylogenetic relationships.This study provides techniques that enable the application of phylogenies in bioscreening, but also sheds light on the processes that shape cross-cultural ethnomedicinal patterns. This community phylogenetic approach demonstrates that similar ethnobotanical uses can arise in parallel in different areas where related plants are available. With a vast amount of ethnomedicinal and phylogenetic information available, we predict that this field, after further refinement of the techniques, will expand into similar research areas, such as pest management or the search for bioactive plant-based compounds

Controlled Release from Cleavable Polymerized Liposomes upon Redox and pH Stimulation

A gallate derivative with three propargyl groups was coupled to palmitoyl oleoyl phosphoethanolamine (POPE). The resulting anionic lipid was formulated with common lipids such as palmitoyl oleoyl phosphatidyl choline (POPC) to form large unilamellar vesicles (LUVs). Polymerization of the LUVs was accomplished by the Cu(I)-catalyzed click reaction between the propargyl groups and the azide groups in the cross-linker. When the cross-linker contained a disulfide or ketal group, the resulting polymerized liposomes depolymerized and released entrapped contents upon the addition of a reducing thiol or under weakly acidic conditions. The click reaction allowed simultaneous multivalent surface functionalization during cross-linking, making these cleavable polymerized liposomes (CPLs) potentially very useful in the delivery and controlled release of pharmaceutical agents

Effect of Interlaminar Epidural Steroid Injection in Acute and Subacute Pain Due to Lumbar Disk Herniation: A Randomized Comparison of 2 Different Protocols

In order to assess the efficacy of epidural steroid injections (ESI) in acute and subacute pain due to lumbar spine disk herniation, we conducted a randomized trial, comparing 2 different protocols. Fourty patients with radicular pain due to L4-L5 and L5-S1 disc herniation were assigned to receive either 3 consecutive ESI every 24 hours through a spinal catheter (group A) or 3 consecutive ESI every 10 days with an epidural needle (group B). All patients had improved Oswestry Disabilty Index (ODI) and the Visual Analog Scale (VAS) for pain scores at 1 month of follow-up compared to baseline, while no significant differences were observed between the 2 groups. The scores for group B were statistically significant lower at 2 months of follow-up compared to those of group A. The improvement in the scores of group B was continuous since the mean scores at 2 months of follow up were lower compared to the respective scores at 1 month. Protocol B (3 consecutive ESI every 10 days) was found more effective in the treatment of subacute pain compared to Protocol A (3 consecutive ESI every 24 hours) with statistically significant differences in the ODI and VAS scores at 2 months of follow-up

A Review of Sociological Issues in Fire Safety Regulation

This paper presents an overview of contemporary sociological issues in fire safety. The most obviously social aspects of fire safety—those that relate to the socioeconomic distribution of fire casualties and damage—are discussed first. The means that society uses to mitigate fire risks through regulation are treated next; focusing on the shift towards fire engineered solutions and the particular challenges this poses for the social distribution and communication of fire safety knowledge and expertise. Finally, the social construction of fire safety knowledge is discussed, raising questions about whether the confidence in the application of this knowledge by the full range of participants in the fire safety design and approvals process is always justified, given the specific assumptions involved in both the production of the knowledge and its extension to applications significantly removed from the original knowledge production; and the requisite competence that is therefore needed to apply this knowledge. The overarching objective is to argue that the fire safety professions ought to be more reflexive and informed about the nature of the knowledge and expertise that they develop and apply, and to suggest that fire safety scientists and engineers ought to actively collaborate with social scientists in research designed to study the way people interact with fire safety technology

Design and Synthesis of Potent in Vitro and in Vivo Anticancer Agents Based on 1-(3′,4′,5′-Trimethoxyphenyl)-2-Aryl-1H-Imidazole

A novel series of tubulin polymerization inhibitors, based on the 1-(3',4',5'-trimethoxyphenyl)-2-aryl-1H-imidazole scaffold and designed as cis-restricted combretastatin A-4 analogues, was synthesized with the goal of evaluating the effects of various patterns of substitution on the phenyl at the 2-position of the imidazole ring on biological activity. A chloro and ethoxy group at the meta- and para-positions, respectively, produced the most active compound in the series (4o), with IC50 values of 0.4-3.8 nM against a panel of seven cancer cell lines. Except in HL-60 cells, 4o had greater antiproliferative than CA-4, indicating that the 3'-chloro-4'-ethoxyphenyl moiety was a good surrogate for the CA-4 B-ring. Experiments carried out in a mouse syngenic model demonstrated high antitumor activity of 4o, which significantly reduced the tumor mass at a dose thirty times lower than that required for CA-4P, which was used as a reference compound. Altogether, our findings suggest that 4o is a promising anticancer drug candidate that warrants further preclinical evaluation

Triterpene Saponins from the Aerial Parts of Trifolium medium L. var. sarosiense

Seven previously unreported triterpene glycosides (1−7) were isolated from methanol extract of the aerial parts of Trifolium medium var. sarosiense (zigzag clover). Their structures were established by the extensive use of 1D and 2D NMR experiments along with ESI-MS and HRMS analyses. Compounds 1−7 are oleanane derivatives characterized by the presence of a keto group at C-22 of an aglycone and a primary alcoholic function at C-24 and differing functions at C-30. Among these, compounds 1−3 and 6 showed a secondary alcoholic function at C-11, which is methoxylated in compounds 4 and 7. Compound 5 was shown to possess a known aglycone, wistariasapogenol A; however, it is described here for the first time as a saponin constituent of the Trifolium genus. Some aspects of taxonomic classification of zigzag clover are also discussed