Air-stable, efficient electron doping of monolayer MoS2 by salt–crown ether treatment

To maximize the potential of transition-metal dichalcogenides (TMDCs) in device applications, the development of a sophisticated technique for stable and highly efficient carrier doping is critical. Here, we report the...

Anaesthesia with diethyl ether impairs jasmonate signalling in the carnivorous plant Venus flytrap (Dionaea muscipula)

Background and Aims General anaesthetics are compounds that induce loss of responsiveness to environmental stimuli in animals and humans. The primary site of action of general anaesthetics is the nervous system, where anaesthetics inhibit neuronal transmission. Although plants do not have neurons, they generate electrical signals in response to biotic and abiotic stresses. Here, we investigated the effect of the general volatile anaesthetic diethyl ether on the ability to sense potential prey or herbivore attacks in the carnivorous plant Venus flytrap (Dionaea muscipula). Methods We monitored trap movement, electrical signalling, phytohormone accumulation and gene expression in response to the mechanical stimulation of trigger hairs and wounding under diethyl ether treatment. Key Results Diethyl ether completely inhibited the generation of action potentials and trap closing reactions, which were easily and rapidly restored when the anaesthetic was removed. Diethyl ether also inhibited the later response: jasmonic acid (JA) accumulation and expression of JA-responsive genes (cysteine protease dionain and type I chitinase). However, external application of JA bypassed the inhibited action potentials and restored gene expression under diethyl ether anaesthesia, indicating that downstream reactions from JA are not inhibited. Conclusions The Venus flytrap cannot sense prey or a herbivore attack under diethyl ether treatment caused by inhibited action potentials, and the JA signalling pathway as a consequence.

Anaesthesia with diethyl ether impairs jasmonate signalling in the carnivorous plant Venus flytrap (Dionaea muscipula)

SummaryGeneral anaesthetics are compounds that induce loss of responsiveness to environmental stimuli in animals and humans. The primary site of general anaesthetic action is the nervous system, where anaesthetics inhibit neuronal transmission. Although plants do not have neurons, they generate electrical signals in response to biotic and abiotic stresses. Here, we investigated the effect of the general volatile anaesthetic diethyl ether on the ability to sense potential prey or herbivore attacks in the carnivorous plant Venus flytrap (Dionaea muscipula). We monitored trap movement, electrical signalling, phytohormone accumulation and gene expression in response to the mechanical stimulation of trigger hairs and wounding under diethyl ether treatment. Diethyl ether completely inhibited the generation of action potentials and trap closing reactions, which were easily and rapidly restored when the anaesthetic was removed. Diethyl ether also inhibited the later response: jasmonate (JA) accumulation and expression of JA-responsive genes. However, external application of JA bypassed the inhibited action potentials and restored gene expression under diethyl ether anaesthesia, indicating that downstream reactions from JA are not inhibited. Thus, the Venus flytrap cannot sense prey or a herbivore attack under diethyl ether treatment. This is an intriguing parallel to the effect of anaesthesia on animals and humans.HighlightCarnivorous plant Venus flytrap (Dionaea muscipula) is unresponsive to insect prey or herbivore attack due to impaired electrical and jasmonate signalling under general anaesthesia induced by diethyl ether.

Synthesis of N-(3-Fluoro-2-phosphonomethoxypropyl) (FPMP) Derivatives of Heterocyclic Bases

A new group of compounds has been prepared: N-(3-fluoro-2-phosphonomethoxypropyl) (FPMP) derivatives of purine and pyrimidine bases which exhibit a significant selective activity against a broad spectrum of retroviruses. Racemic N-(3-fluoro-2-phosphonomethoxypropyl) derivatives of adenin (V), guanine (IX), cytosine (XIII), 2,6-diaminopurine (XXI), 3-deazaadenin e(XVII), xanthine (X) and hypoxanthin (VI) were prepared from the corresponding N-(3-fluoro-2-hydroxypropyl) derivatives after protection of amino group at the heterocyclic ring by selective benzoylation, reaction with diisopropyl p-toluenesulfonyloxymethylphosphonate (II), and subsequent removal of the protecting groups. Chiral FPMP derivatives were prepared by reaction of heterocyclic base with the corresponding chiral synthon (XXX, XXXVII) followed by deprotection. The required chiral synthons were obtained from enantiomeric 3-fluoro-1,2-propanediols by two methods. In the first, the primary hydroxyl group was tritylated, the obtained derivative was reacted with compound II, the trityl group was removed and the product was mesylated to give synthon XXXVII. The second pathway consisted in selective tosylation of the primary hydroxyl group and conversion of the secondary hydroxyl into the acetoxymethyl ether via the methoxymethyl ether; treatment of the acetoxy compound with bromotrimethylsilane and triisopropyl phosphite afforded the desired synthon XXX.

The HI test modified by ether treatment in the sero-epidemiological surveillance of influenza B

SUMMARYEther-treated influenza B haemagglutination inhibition (HI) antigen was used in a study of serum collections from three different epidemic seasons.For diagnostic purposes, ether treatment increased the efficacy of the HI test by about 50 % over the conventional HI technique, raising it to the same level of sensitivity as the complement fixation (CF) test. The treatment reduced the specificity of the HI test, but its reliability in the diagnosis of influenza B infections was only slightly diminished. With regard to evaluation of the immune status of a given population, an HI test using ether-treated antigen from the epidemic influenza B strain seems to give more relevant information about the antibody level associated with protection than a conventional HI test using untreated virus antigen.

Hormonal activation of type-L hormone-sensitive lipase measured in defatted heart powders

Adrenaline, 3-isobutyl-1-methylxanthine (MIX) and dibutyryl cyclic AMP (Bt2 cyclic AMP) stimulated type-L hormone-sensitive lipase (HSL) activity when measurements were made on defatted rat heart powders. These lipolytic agents stimulated the activity of this enzyme in a time- and dose-dependent manner. This activation was reversible, because removal of adrenaline from the perfusate was accompanied by the return of type-L HSL activity to control levels. We have reported [Palmer, Caruso & Oscai (1981) Biochem. J. 198, 159-166] that perfusion with low levels of adrenaline, MIX or Bt2 cyclic AMP reduced type-L HSL activity below control levels when measurements were made in aqueous homogenates. However, in the present study, when activities were measured in acetone/diethyl ether heart powders, all concentrations of these agents studied stimulated enzyme activity, and at no concentration was there enzyme inhibition. These data suggest that acetone/diethyl ether treatment may remove a factor that plays a role in type-L HSL regulation. Type-L HSL activity measured in acetone/diethyl ether powders of control and stimulated rat heart exhibited properties that include alkaline pH optimum, serum requirement, activation by heparin and inhibition by high salt and protamine sulphate. These characteristics, in addition to the stability of the enzyme to treatment with organic solvents, fulfil the requirements for the type-L HSL classification.