Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

A Blend of Ethanol and (−)-α-Pinene were Highly Attractive to Native Siricid Woodwasps (Siricidae,Siricinae) Infesting Conifers of the Sierra Nevada and the Allegheny Mountains

Woodwasps in Sirex and related genera are well-represented in North American conifer forests, but the chemical ecology of native woodwasps is limited to a few studies demonstrating their attraction to volatile host tree compounds, primarily monoterpene hydrocarbons and monoterpene alcohols. Thus, we systematically investigated woodwasp-host chemical interactions in California’s Sierra Nevada and West Virginia’s Allegheny Mountains. We first tested common conifer monoterpene hydrocarbons and found that (?)-α-pinene, (+)-3-carene, and (?)-β-pinene were the three most attractive compounds. Based on these results and those of earlier studies, we further tested three monoterpene hydrocarbons and four monoterpene alcohols along with ethanol in California: monoterpene hydrocarbons caught 72.3% of all woodwasps. Among monoterpene hydrocarbons, (+)-3-carene was the most attractive followed by (?)-β-pinene and (?)-α-pinene. Among alcohols, ethanol was the most attractive, catching 41.4% of woodwasps trapped. Subsequent tests were done with fewer selected compounds, including ethanol, 3-carene, and ethanol plus (?)-α-pinene in both Sierra Nevada and Allegheny Mountains. In both locations, ethanol plus (?)-α-pinene caught more woodwasps than other treatments. We discussed the implications of these results for understanding the chemical ecology of native woodwasps and invasive Sirex noctilio in North America. In California, 749 woodwasps were caught, representing five species: Sirex areolatus Cresson, Sirex behrensii Cresson, Sirex cyaneus Fabricius, Sirex longicauda Middlekauff, and Urocerus californicus Norton. In West Virginia 411 woodwasps were caught representing four species: Sirex edwardsii Brullé, Tremex columba Linnaeus, Sirex nigricornis F., and Urocerus cressoni Norton.     

Enantiomeric Composition of Monoterpene Hydrocarbons in Some Conifers and Receptor Neuron Discrimination of α-Pinene and Limonene Enantiomers in the Pine Weevil, Hylobius abietis

The enantiomeric composition of seven monoterpene hydrocarbons in headspace volatiles of spruce sawdust and seedlings (Picea abies), pine seedlings (Pinus sylvestris), and branches of juniper (Juniperus communis) was determined by gas chromatographic separation on a -Cyclodextrin column. For the six monoterpenes, -pinene, camphene, -pinene, sabinene, limonene, and -phellandrene, both enantiomers were present, whereas for 3-carene only the (+)-configuration was found. The amount of each enantiomer varied considerably both in relation to total amount of all of them, and for the six pairs also in relation to the opposite enantiomer. One olfactory receptor neuron in the pine weevil (Hylobius abietis) showed a strong response to -pinene when stimulated with all four headspace materials via a GC equipped with a DB-WAX column. The same neuron was subsequently tested with repeated stimulations via the GC effluent containing the (+)- or (–)-enantiomer. A marked better response to (+)- than to (–)--pinene was elicited. Another olfactory receptor neuron that responded strongly to limonene when stimulated with the spruce volatiles was tested for enantiomers of limonene. This neuron responded more strongly to (–)- than to (+)-limonene, when stimulated alternately with each of the limonene enantiomers. Discrimination between enantiomers by plant olfactory receptor neurons suggests that the enantiomeric ratios of volatile compounds may be important in host location by the pine weevil.     

Some Aspects in the Development of High Performance Refractories for Iron and Steel Making in China

In the past 25 years in China, to meet with the rapid increase in steel production accompanied by adoption of advanced metallurgical technologies, there has been fast development of China＇ s refractories industry in production capacity, in quality improvement and in development of new products. Sophisticated high performance refractory materials mainly based on our rich reserves of magncsite, bauxite and flake graphite have been developed, such as carbon-bonded products, high purity oxide products, bauxite-based low creep and high strength high alumina bricks and LC, ULC and ZC castables. They have been used in blast furnaces, BOFs, EAFs, secondary refining and continuous casting with considerable improvement in service pecformance.     

Discrepancy Between Antennal and Behavioral Responses for Enantiomers of α-Pinene: Electrophysiology and Behavior of Helicoverpa armigera (Lepidoptera)

The ability of adult cotton bollworm, Helicoverpa armigera (Hübner), to distinguish and respond to enantiomers of alpha-pinene was investigated with electrophysiological and behavioral methods. Electroantennogram recordings using mixtures of the enantiomers at saturating dose levels, and single unit electrophysiology, indicated that the two forms were detected by the same receptor neurons. The relative size of the electroantennogram response was higher for the (-) compared to the (+) form, indicating greater affinity for the (-) form at the level of the dendrites. Behavioral assays investigated the ability of moths to discriminate between, and respond to the (+) and (-) forms of alpha-pinene. Moths with no odor conditioning showed an innate preference for (+)-alpha-pinene. This preference displayed by naive moths was not significantly different from the preferences of moths conditioned on (+)-alpha-pinene. However, we found a significant difference in preference between moths conditioned on the (-) enantiomer compared to naive moths and moths conditioned on (+)-alpha-pinene, showing that learning plays an important role in the behavioral response. Moths are less able to distinguish between enantiomers of alpha-pinene than different odors (e.g., phenylacetaldehyde versus (-)-alpha-pinene) in learning experiments. The relevance of receptor discrimination of enantiomers and learning ability of the moths in host plant choice is discussed.     

Using dilatometry in the reversible addition fragmentation transfer polymerization of N-(S)-(−)-α-methylbenzyl methacryloylamine

Optically active polymers were prepared using reversible addition-fragmentation chain transfer polymerization (RAFT) of N-(S)-α-methylbenzylmethacryloylamine (N-(S)-α-MBMA), a functional optically active monomer. RAFT polymerizations were carried out at 70 °C in ethanol using AIBN as a thermal initiator and benzyl or (1-phenyl)ethyl dithiobenzoate (BDB and PEDB, respectively) as the RAFT agents. The kinetic study was performed by dilatometry. Plots of conversion vs time indicated that the polymerizations followed first order kinetics. ¹H NMR, IR, and UV–vis spectrophotometric studies confirmed the presence of thiocarbonylthio moieties (−SCS-) in the polymer chains. The molecular weight distributions (MWDs) were moderately narrow with polydispersity indices between 1.3 and 1.6, which indicated that the control of the reaction was not completely achievement using BDB or PEDB as RAFT agents. The optical activity [α]_D²⁵ measurements of synthesized polymers by RAFT did not show a noticeably linear increase dependence with respect to molecular weight, as was previously reported for another controlled free radical polymerization (CRP) system.     

Some Nonparametric Tests for Change-Point Detection Based on the ℙ-ℙ and ℚ-ℚ Plot Processes

Abstract

We propose nonparametric procedures for testing change-point by using the ?-? and ?-? plots processes. The limiting distributions of the proposed statistics are characterized under the null hypothesis of no change and also under contiguous alternatives. We give an estimator of the change-point coefficient and obtain its strong consistency. We introduce the bootstrapped version of ?-? and ?-? processes, requiring the estimation of quantile density, and obtain their limiting laws. Finally, we propose and investigate the exchangeable bootstrap of the empirical ?-? plot and ?-? plot processes which avoids the problem of the estimation of quantile density, which is of its own interest. These results are used for calculating p-values of the proposed test statistics. Emphasis is placed on the explanation of the strong approximation methodology.     

Structure,Function and Mechanism of N-Glycan Processing Enzymes: endo-α-1,2-Mannanase and endo-α-1,2-Mannosidase

While most glycosidases that act on N-linked glycans remove a single sugar residue at a time, endo-α-1,2-mannosidases and endo-α-1,2-mannanases of glycoside hydrolase family GH99 cut within a chain and remove two or more sugar residues. They are stereochemically retaining enzymes that use an enzymatic mechanism involving an epoxide intermediate. Human endo-α-1,2-mannosidase (MANEA) trims glucosylated mannose residues; the endomannosidase pathway provides a glucosidase-independent pathway for glycoprotein maturation. Cell-active MANEA inhibitors alter N-glycan processing and reduce infectivity of dengue virus, demonstrating that MANEA has potential as a host-directed antiviral target. Sequence-related enzymes from gut Bacteroides spp. exhibit endo-α-1,2-mannosidase activity and are a fruitful test bed for structure-guided inhibitor development. The genes encoding the Bacteroides spp. enzymes sit within polysaccharide utilization loci and are preferential endo-α-1,2-mannanases.     

Highly stereoselective epoxidation of (−)-α-pinene over chiral transition metal (salen) complexes occluded in zeolitic hosts

Various transition metal complexes of seven different salen ligands have been incorporated in specially modified zeolitic host materials. The thus immobilized sterically demanding complexes have been tested in the diastereoselective epoxidation of (–)--pinene in the liquid phase in an autoclave at room temperature and elevated pressure using O₂ as oxidant. In most cases conversions of 100% could be achieved. Best results so far – 100% conversion, 96% epoxide chemoselectivity and 91% diastereomeric excess – have been obtained in the presence of the entrapped [(R,R)-(N,N)-bis(3,5-di-tert-butylsalicylidene)-1,2-diphenylethylenediamino]cobalt(II) = Co(salen-5) complex. Computer simulations were done in order to prove that the reaction can take place inside the pore system, i.e., (–)--pinene is able to diffuse through the microporous entrances of the carrier material.     

Thermo-responsive block copolymer micelle-supported (S)-α,α-diphenylprolinol trimethylsilyl ether for asymmetric Michael addition of nitroalkenes and aldehydes in water

An amphiphilic block copolymer PNIPAM₅₃-b-(PS₃₀-co-P4AMS₁₀) was facilely prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization. The immobilization of (S)-α,α-diphenylprolinol trimethylsilyl ether onto the block copolymers was then performed through using copper-catalyzed alkyne-azide cycloaddition (CuAAC), and the generating amphiphilic diblock copolymer supported chiral catalyst PNIPAM₅₃-b-(PS₃₀-co-P4AMS₁₀)/proTMS was self-assembled into micelles with regular diameters about 50 nm in aqueous solution. The micellar catalyst was further used for the asymmetric Michael reaction between propanal and trans-β-nitrostyrene in water. Using only 1 mol% micellar catalyst, the corresponding Michael addition products could be obtained in good yields and high enantioselectivities as well as good diastereoselectivities. In addition, this micellar catalyst could be reused at least for four times. Moreover, the micellar catalyst could be applied for the asymmetric addition reaction of 4-chlorocinnamyl aldehyde and nitromethane, and thus constructing the baclofen pharmaceutical intermediate.     

α- and γ-tocotrienols are metabolized to carboxyethyl-hydroxychroman derivatives and excreted in human urine

Limited information is available regarding metabolism of vitamin E forms, especially the tocotrienols. Carboxyethyl-hydroxychromans (α-and γ-CEHC) are human urinary metabolites of α- and γ-tocopherols, respectively. To evaluate whether tocotrienols are also metabolized and excreted as urinary CEHC, urine was monitored following tocotrienol supplementation. Complete (24 h) urine collections were obtained for 2 d prior to (baseline), the day of, and 2 d after human subjects (n=6) ingested tocotrienol supplements. The subjects consumed 125 mg γ-tocotrienyl acetate the first week, then the next week 500 mg; then 125 mg α-tocotrienyl acetate was administered the third week, followed by 500 mg the fourth week. Urinary α- and γ-CEHC were measured by high-performance liquid chromatography with electrochemical detection. Urinary γ-CEHC levels rose about four- to sixfold in response to the two doses of γ-tocotrienol and then returned to baseline the following day. Significant (P<0.0001) increases in urinary α-CEHC were observed only following ingestion of 500 mg α-tocotrienyl acetate. Typically, 1–2% of α-tocotrienyl acetates or 4–6% of γ-tocotrienyl acetates were recovered as their respective urinary CEHC metabolites. A γ-CEHC excretion time course showed an increase in urinary γ-CEHC at 6 h and a peak at 9 h following ingestion of 125 mg γ-tocotrienyl acetate. In summary, tocotrienols, like tocopherols, are metabolized to CEHC; however, the quantities excreted in human urine are small in relation to dose size.     

Developemnt and Application of Al2O3—MgO Castable for Large Ladles in Con—casting System

Using Al2O3-MgO castable in large ladle can avoid containation of molten steel from carbon-containing refractories and increas ladle servic life remarkably,The addition of magnesia and fine powder,the effect of grain size on the proper-ties of the castable,especially linear change and structure spalling have been studied,Castable pro-dued for large ladle with small weare rate has got good applicatio result.     

Radiolabelled Cyclic Bisarylmercury: High Chemical and in vivo Stability for Theranostics

We show the synthesis of an in vivo stable mercury compound with functionality suitable for radiopharmaceuticals. The designed cyclic bisarylmercury was based on the water tolerance of organomercurials, higher bond dissociation energy of Hg−Ph to Hg−S, and the experimental evidence that acyclic structures suffer significant cleavage of one of the Hg−R bonds. The bispidine motif was chosen for its in vivo stability, chemical accessibility, and functionalization properties. Radionuclide production results in ^197(m)HgCl₂(aq), so the desired mercury compound was formed via a water-tolerant organotin transmetallation. The Hg-bispidine compound showed high chemical stability in tests with an excess of sulfur-containing competitors and high in vivo stability, without any observable protein interaction by human serum assay, and good organ clearance demonstrated by biodistribution and SPECT studies in rats. In particular, no retention in the kidneys was observed, typical of unstable mercury compounds. The ^natHg analogue allowed full characterization by NMR and HRMS.     

αVβ6 Integrin: An Intriguing Target for COVID-19 and Related Diseases

The outbreak of SARS-CoV-2 has been an extraordinary event that constituted a global health emergency. As the novel coronavirus is continuing to spread over the world, the need for therapeutic agents to control this pandemic is increasing. α_Vβ₆ Integrin may be an intriguing target not only for the inhibition of SARS-CoV-2 entry, but also for the diagnosis/treatment of COVID-19 related fibrosis, an emerging type of fibrotic disease which will probably affect a significant part of the recovered patients. In this short article, the possible role of this integrin for fighting COVID-19 is discussed on the basis of recently published evidence, showing how its underestimated involvement may be interesting for the development of novel pharmacological tools.     

Rh–Fe/Ca–Al2O3: A Unique Catalyst for CO-Free Hydrogen Production in Low Temperature Ethanol Steam Reforming

Low temperature ethanol steam reforming (ESR) was studied over a series of 1 wt% Rh–x % Fe catalysts with various Fe loading (x = 0–10 wt%) and on different supports (Ca–Al₂O₃, SiO₂ and ZrO₂). The results show that close interaction between Rh and Fe is required to reduce the CO selectivity to almost negligible values. In addition, Rh–Fe supported on Ca–Al₂O₃ exhibits the best performance in terms of CO selectivity and hydrogen yield as compared to other supports. Characterization by XPS and XANES indicates the presence of Fe_xO_y species upon reduction, resulting in the formation of coordinatively unsaturated ferrous (CUF) active sites along the Rh–Fe_xO_y interface. These CUF sites promote water–gas shift reaction during low temperature ESR. Temperature programmed oxidation and Raman spectroscopy of spent catalysts also indicate that the addition of iron oxide reduces coke deposition and forms more reactive coke. Hence, the catalyst lifespan is significantly extended.     

Heat conduction in multiphase systems—I: Theory and experiment for two-phase systems

The method of volume averaging is applied to the process of transient heat conduction in two- and three-phase systems, and a closure scheme is developed that allows for direct determination of the thermal conductivity tensor. Previous experimental studies have been extended to cover a wide range of parameters and for two-phase systems values of the effective thermal conductivity have been measured for conductivity ratios as high as κ = k_σ/k_β = 8000. Here k_σ is the conductivity of the discontinuous phase and k_β is the conductivity of the continuous phase. For large values of κ a combined numerical and perturbation method was used to predict the effective thermal conductivity. Good agreement between theory and experiment is obtained; however, the particle-particle contact was treated in an empirical manner.