In-situ construction of direct Z-scheme NiO/Bi2MoO6 heterostructure arrays with enhanced room temperature ether sensing properties under visible light irradiation

Light irradiation has emerged as a promising strategy to promote room temperature sensing of resistive-type semiconductor gas sensors recently. However, high recombination rate of photo-generated carriers and poor visible light response of conventional semiconductor sensing materials have greatly limited the further performance improvement. It is urgent to develop gas sensing materials with high photo-generated carrier separation efficiency and excellent visible light response. Herein, a novel direct Z-scheme NiO/Bi₂MoO₆ heterostructure arrays were designed and in-situ constructed on alumina flat substrate to form thin film sensors, which realized excellent room temperature gas response towards ether under irradiation of visible light for the first time, together with excellent stability and selectivity. Based on density functional theory calculation and experimental characterization, it was demonstrated that the construction of Z-scheme heterostructure could greatly promote the separation of photo-generated carriers and adsorption of ether. Moreover, the excellent visible light response characteristics of NiO/Bi₂MoO₆ could improve the utilization of visible light. In addition, the in-situ construction of array structure could avoid a series of problems caused by the conventional thick film devices. The work not only provides a promising guideline for Z-scheme heterostructure arrays in promoting the room temperature sensing performance of semiconductors gas sensors under visible light irradiation, but also clarifies the gas sensing mechanism of Z-scheme heterostructure at the atomic and electronic level.

Bygone Ether: Theriac to Obstinate Hiccups-Food for Thought!

How to cite this article: Hirolli D, Panda R, Baidya DK. Bygone Ether: Theriac to Obstinate Hiccups-Food for Thought! Indian J Crit Care Med 2022;26(7):884.

[175 years of anesthesia and narcosis-Towards a "human right to unconsciousness"]

The Ether Day, a key moment in the history of mankind, commemorates its 175th anniversary on 16 October 2021. On that day the dentist William T. G. Morton successfully gave the first public ether anesthesia in Boston. From then on it was possible to save people from pain with justifiable risk and at the same time to protect them from psychological damage by inducing unconsciousness. The German philosopher Peter Sloterdijk, one of the most renowned and effective philosophers of our times, deduced that from then on humans, to some extent, had a right to unconsciousness when in psychophysical distress. This postulate unfolded from his concept of "anthropotechnics" developed around 1997, meaning the idea of treating human nature as an object of possible improvements. According to Sloterdijk, in favorable cases a synthesis of man and technology can result in a significant improvement of human capabilities in the sense of "enhancement", i.e. an increase, an improvement or even an expansion of intellectual, physical or psychological possibilities, as it were in a transgression of the human (so-called transhumanism). Man should go into vertical tension, i.e. strive for higher aims and exploit his inherent potential, he should not dwell in the horizontal. This is not meant as an appeal but as an imperative: "You must change your life!". In this context modern anesthesia may prove helpful: be operated on by others in order to undergo an enhancement. Or, in its most extreme form, the operation in the "auto-operational curved space", a person can even operate on himself as has been dramatically demonstrated by Rogozov, a young Russian physician and trainee surgeon who successfully performed a self-appendectomy under local anesthesia at the Novolazarevskaya Antarctic Station in 1961; however, the implementation of this idea is a long way off. On the one hand, many countries lack qualified personnel in sufficiently large numbers to perform even vital operations with patients under anesthesia. On the other hand, over the decades it has become clear that anesthesia is obviously beneficial for mankind in that it offers relief from pain and psychological stress but that it can also often show its dark side: substance abuse, use of anesthetics in torture and in executions. In addition, the role of anesthetics in resuscitation, palliative care, and allaying executions is unclear or controversial. Finally, the necessary formal legal steps to acknowledge a "human right to unconsciousness" have not yet been implemented.

Killed by its own obituaries: Explaining the demise of the ether

In this paper I follow the demise of the ether in the first half of the twentieth century to show how the first obituaries of the ether were instrumental in creating an object with specific and largely simplified properties related to, but different from, nineteenth-century ethers. I suggest that writing the history of dead objects (or objects an author wants to be dead) is not epistemologically neutral but, on the contrary, it involves a reformulation of the object itself. I show that this was indeed the case with the ether: those arguing for its demise in the early twentieth century tended to overlook as irrelevant one of the ether's most important properties, namely being the seat for the transmission of electromagnetic waves. Instead, they emphasized the contradictions between other properties of previous ether(s), so as to advocate for its disappearance.

Morton's Letheon: When was the name Letheon chosen?

Letheon was the commercial name that Boston dentist William T. G. Morton chose for his ether-based "preparation" that was inhaled to produce insensibility during surgical and dental procedures. The multiple editions of Edward Warren's Some Account of the Letheon (1847) as well as Nathan P. Rice's Trials of a Public Benefactor (1859) provide the only known accounts of the meeting hosted by the physician Augustus A. Gould at which the name Letheon was chosen. Neither Warren nor Rice mentions when the meeting occurred. In all likelihood, it was held at some point in a three-week period from mid-November to just short of December 9, 1846, the publication date of the earliest known reference to the name. The absence of the word Letheon in Morton's public notices around the end of November 1846 or, indeed, in any document until his December 9 advertisement in The Boston Medical and Surgical Journal suggests a later date for the meeting than has been previously reported.

The Roots of Pressure Anesthesia and its Contemporary Similarities

For decades dentists have faced the challenge of achieving profound anesthesia in the presence of a severe tooth ache. Frequently this challenge was more acute when the tooth or teeth in question were mandibular molars. Over a 125 years ago this clinical dilemma was managed by using cocaine, both directly on an exposed dental pulp and often times using a solution of such injected directly into the pulp. Both clinical applications were considered as achieving "pressure anesthesia" sufficient to permit pulp extirpation. This historical perspective will focus on both the origins of this approach and its contemporary counterparts.

Sulfoethylation of polysaccharides-A comparative study

The heterogeneous sulfoethylation of cellulose, xylan, α-1,3-glucan, glucomannan, pullulan, curdlan, galactoglucomannan, and agarose was studied using sodium vinylsulfonate (NaVS) as reagent in presence of sodium hydroxide and iso-propanol (i-PrOH) as slurry medium. The influence of the concentration of polymer, water, and NaOH (solid or aqueous solution) on the degree of substitution (DS) was investigated. The sulfoethylation rendered the polysaccharides studied water-soluble. Sulfoethylation of heteropolysaccharides yielded products with higher DS compared to the conversion of homopolysaccharides. Structure characterization was carried out by means of ¹³C-NMR spectroscopy.

Aluminium nanoparticle modelling coupled with molecular dynamic simulation method to compare the effect of annealing rates on diethyl ether coating and oxidation behaviours

This study was conducted to examine the influence of annealing rates on coating and oxidation performances of Aluminium (Al) nanoparticle (ANP) by molecular dynamic (MD) simulations. Four levels of cooling rates were utilized on melted ANP to obtain annealed ANP models with different microstructures. Then those nanoparticles were placed into pure diethyl ether or oxygen gas environments to perform coating and oxidation simulations respectively. It was revealed that there was a relatively optimal annealing condition for ANP models to recover the initial microstructure of themselves as much as possible. The ether coating behaviour of annealed ANP model under this condition was better than other models. In contrast, the oxidation of all different models was almost the same. So, the factor of the annealing rate had little effect on the oxidation results. Along with the growth of the oxide layer, the core of ANP still kept its annealed microstructure.

Mechanism and catalytic performance for direct dimethyl ether synthesis by CO2 hydrogenation over CuZnZr/ferrierite hybrid catalyst

Direct synthesis of dimethyl ether (DME) by CO₂ hydrogenation has been investigated over three hybrid catalysts prepared by different methods: co-precipitation, sol-gel, and solid grinding to produce mixed Cu, ZnO, ZrO₂ catalysts that were physically mixed with a commercial ferrierite (FER) zeolite. The catalysts were characterized by N₂ physisorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), temperature programmed desorption of CO₂ (CO₂-TPD), temperature programmed desorption of NH₃ (NH₃-TPD), and temperature programmed H₂ reduction (H₂-TPR). The results demonstrate that smaller CuO and Cu crystallite sizes resulting in better dispersion of the active phases, higher surface area, and lower reduction temperature are all favorable for catalytic activity. The reaction mechanism has been studied using in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Methanol appears to be formed via the bidentate-formate (b-HCOO) species undergoing stepwise hydrogenation, while DME formation occurs from methanol dehydration and reaction of two surface methoxy groups.

Anesthetics influence concussive head injury induced blood-brain barrier breakdown, brain edema formation, cerebral blood flow, serotonin levels, brain pathology and functional outcome

Several lines of evidences show that anesthetics influence neurotoxicity and neuroprotection. The possibility that different anesthetic agents potentially influence the pathophysiological and functional outcome following neurotrauma was examined in a rat model of concussive head injury (CHI). The CHI was produced by an impact of 0.224N on the right parietal bone by dropping a weight of 114.6g from a 20cm height under different anesthetic agents, e.g., inhaled ether anesthesia or intraperitoneally administered ketamine, pentobarbital, equithesin or urethane anesthesia. Five hour CHI resulted in profound volume swelling and brain edema formation in both hemispheres showing disruption of the blood-brain barrier (BBB) to Evans blue and radioiodine. A marked decrease in the cortical CBF and a profound increase in plasma or brain serotonin levels were seen at this time. Neuronal damages were present in several parts of the brain. These pathological changes were most marked in CHI under ether anesthesia followed by ketamine (35mg/kg, i.p.), pentobarbital (50mg/kg, i.p.), equithesin (3mL/kg, i.p.) and urethane (1g/kg, i.p.). The functional outcome on Rota Rod performances or grid walking tests was also most adversely affected after CHI under ether anesthesia followed by pentobarbital, equithesin and ketamine. Interestingly, the plasma and brain serotonin levels strongly correlated with the development of brain edema in head injured animals in relation to different anesthetic agents used. These observations suggest that anesthetic agents are detrimental to functional and pathological outcomes in CHI probably through influencing the circulating plasma and brain serotonin levels, not reported earlier. Whether anesthetics could also affect the efficacy of different neuroprotective agents in CNS injuries is a new subject that is currently being examined in our laboratory.

Anaesthetic or "Antiaesthetic" or "Antaesthetic"? Correspondence From Andrew Buchanan, MD, to James Simpson, MD, Concerning a Name for the Agents Producing Insensibility

In November 1847, James Young Simpson, MD, of Edinburgh, Scotland, applied the word anaesthesia to the state of narcotism and insensibility produced by the inhaled vapors of sulfuric ether and chloroform, along with the word anaesthetic as an adjective to denote that state and as a generic term for agents capable of inducing the state of insensibility. In March 1848, Andrew Buchanan, MD, of Glasgow, Scotland, penned a letter to Simpson to suggest a more semantically precise word, the spelling of which is not clear in Buchanan's letter. We do not know whether Simpson replied to Buchanan. Simpson continued using the words anaesthesia and anaesthetic in his publications.

A Newly Discovered Manuscript of Charles T. Jackson, MD, on the Preparation and Administration of Anesthetics for Humans and Animals

A newly discovered handwritten manuscript of Charles T. Jackson, MD, contains instructions for the preparation and administration of sulfuric ether, information on Jackson's preferred mixture of ether and chloroform, an account of his experiments with other potential anesthetic agents, and his comments on etherizing cattle and other animals. Jackson's nine-page manuscript is believed to have been written in the autumn of 1851, around the time that he submitted his memorial on the discovery of etherization to Baron von Humboldt, and made a separate submission to the US Congress.

Morton Patented the "Ethereal Solution of Opium" of Elton Romeo Smilie

The Jackson-Morton 1846 patent for surgical insensibility by means of sulphuric ether states that opiates can be added to the ether and co-administered by inhalation. The erroneous concept that ether could carry opiates in its vapor phase at room temperature was proposed in Boston in 1846 by Elton Romeo Smilie (1819-1889), who believed that the opiates were more important than the ether vehicle.

Antidepressant-like effect of active fraction of Polyrhachisvicina Roger in a rat depression model

OBJECTIVE

To investigate the antidepressant-like effect of active fraction of Polyrhachis vicina Roger (AFPR) in a rat depression model, and to elucidate the underlying mechanism.

METHODS

AFPR was extracted with ethanol followed by petroleum ether. Its antidepressant-like effect was investigated in mice by tail suspension test (TST), forced swimming test (FST) and open field test (OPT). A repeated dose of reserpine (0.5 mg/kg, daily for 14 d) was used to establish a rat depression model. Fluoxetine was used as positive control agent. The effect of AFPR on reserpine-induced ptosis, hypothermia and akinesia, the levels of monoamines and their metabolites, and the activity of monoamine oxidase (MAO) in hippocampus and prefrontal cortex were determined.

RESULTS

Administration of AFPR by gavage at 160 and 320 mg/kg significantly reduced the duration of immobility in the FST and TST, and did not affect locomotor activity in the OPT. In the reserpine-induced depression model, AFPR attenuated anhedonia, demonstrated by reversing hypothermia, akinesia and sucrose consumption. AFPR significantly increased the concentration of monoamines, including dopamine, serotonin, noradrenaline and acetylcholine.

CONCLUSION

AFPR normalized the metabolism rates of noradrenaline, serotonin and dopamine, and the activity of MAO, which were altered by chronic reserpine exposure. The findings suggest that modulation of the monoaminergic neurotransmitter system likely underlies the antidepressant-like effect of AFPR.

John Snow and the First Second-Gas Effect

In 1847, British anesthesia pioneer John Snow (1813-1858) observed that patients did not manifest cyanosis during induction with hypoxic mixtures of ether vapor in air. He hypothesized a molecular mechanism that would be understood over a century later as the second gas effect.

Jackson, MD: "History of the Patenting of the Application of Sulphuric Ether for the Production of Insensibility"

In 2016, the Wood Library-Museum of Anesthesiology, Schaumburg, IL, acquired an unpublished 11-page manuscript written by Charles Thomas Jackson, MD, (1805-1880). The undated manuscript, now fully transcribed, provides Jackson's perspective of the first 6 weeks of the ether discovery, from early October 1846 to mid-November 1846. It chronicles Jackson's observations and discussions pertaining to United States Patent No. 4848, granted to him and William Thomas Green Morton, MD, (1819-1868). Jackson's manuscript did not yield new information on the discovery of surgical etherization or the subsequent dispute between him and Morton. The manuscript may, nevertheless, be one of the earliest documents on etherization known to have been written by Jackson.

Synthesis, surfactant properties and antimicrobial activities of methyl glycopyranoside ethers

A series of amphiphilic methyl glucopyranoside ethers incorporating various alkyl chain lengths has been synthesized from commercially available methyl glucopyranosides following an acetalisation/hydrogenolysis sequence. The amphiphilic properties of ethers and acetal intermediates were evaluated. Both families exhibit excellent surfactant properties with a maximum efficiency obtained for compounds bearing a linear dodecyl chain (CMC = 0.012 mM, γ_sat. = 30 mN m^-1). Antimicrobial activity studies revealed an efficient activity (0.03 < MIC < 0.12 mM) against Gram-positive bacteria such as Listeria monocytogenes, Enterococcus faecalis, Enterococcus faecium and Staphylococcus aureus. More importantly, these compounds were found to be active against multi-resistant strains such as vancomycin-, methicillin- and daptomycin-resistant strains. Finally, it was found that antimicrobial activities are closely related to physicochemical properties and are also influenced by the nature of the carbohydrate moiety.

Near infrared cavity enhanced absorption spectra of atmospherically relevant ether-1, 4-Dioxane

1, 4-Dioxane (DX) is a commonly found ether in industrially polluted atmosphere. The near infrared absorption spectra of this compound has been recorded in the region 5900-8230 cm(-1) with a resolution of 0.08 cm(-1) using a novel Fourier transform incoherent broadband cavity-enhanced absorption spectrometer (FT-IBBCEAS). All recorded spectra were found to contain regions that are only weakly perturbed. The possible combinations of fundamental modes and their overtone bands corresponding to selected regions in the measured spectra are tabulated. Two interesting spectral regions were identified as 5900-6400 cm(-1) and 8100-8230 cm(-1). No significant spectral interference due to presence of water vapor was observed suggesting the suitability of these spectral signatures for spectroscopic in situ detection of DX. The technique employed here is much more sensitive than standard Fourier transform spectrometer measurements on account of long effective path length achieved. Hence significant enhancement of weaker absorption lines above the noise level was observed as demonstrated by comparison with an available measurement from database.

A History of Intravenous Anesthesia in War (1656-1988)

The practice of anesthesia in war places significant restraints on the choice of anesthetic technique used; these include, but are not limited to, safety, simplicity, and portability. Ever since intravenous anesthesia became a practical alternative, there have been military doctors who felt that this technique was particularly suited to this environment. The challenge, as in civilian practice, has been to find the appropriate drugs as well as simple and safe delivery systems. The urgency of war has always stimulated innovation in medicine to counteract the ongoing development of weapons of war and their effects on the human body and to achieve improved survival as public expectations rise. This article traces the development of and the use of intravenous anesthesia by military physicians for battle casualties. The story starts long before the era of modern anesthesia, and the discussion concludes in the dog days of the cold war. The rapidly increasing interest in intravenous anesthesia in both civilian and military practice since the early 1990s is left for other authors to examine.

Effects of volatile organic compound ether on cell responses and gene expressions in Arabidopsis

BACKGROUND

The volatile organic compound ether is widely used as an industrial solvent and easily released to the environment. Our previous research indicated that ether triggers reactive oxygen species (ROS) production and activates ethylene biosynthetic genes and defense gene expressions in tomato. In the present study, we investigated the effect of ether on cell responses and gene expressions in Arabidopsis and compared the ROS and phytohormones produced in Arabidopsis and tomato plants in response to different air pollutants (O₃ vs. ether).

RESULTS

Ether induced the sequential production of superoxide anion and hydrogen peroxide in Arabidopsis. Ether also triggered expressions of ethylene, salicylic acid and jasmonic acid biosynthetic genes. The temporal expression patterns of MAP kinase and protein phosphatase genes are in good accordance with those of the ethylene and salicylic acid biosynthetic genes, suggesting that induction of these phytohormone biosynthesis were through signaling pathways including both phosphorylation and/or dephosphorylation. By contrast, expression pattern of protein phosphatase PP2A3&4 coincided well with the expression of jasmonic acid biosynthetic gene LOX4, suggesting that induction of jasmonic acid biosynthesis is through PP2A3&4. However, the production of ROS and temporal expression patterns of phytohormone biosynthetic genes in Arabidopsis in response to ether were different from those to O₃ and were different from those in tomato as well.

CONCLUSIONS

Different plants have different strategies to respond to the same abiotic stress, and each plant species possesses its own unique signaling pathways that regulate the responding process.

Evaluation of different inactivation methods for high and low pathogenic avian influenza viruses in egg-fluids for antigen preparation

In view of the emerging avian influenza (AI) viruses, it is important to study the susceptibility of AI viruses to inactivating agents for preparation of antigens and inactivated vaccines. The available information on susceptibility of both the high and low pathogenic AI viruses to different inactivating agents is inadequate and ambiguous. It has been shown that different subtypes of influenza viruses require different physical and chemical conditions for inactivation of infectivity. The present study was undertaken to evaluate the use of beta-propiolactone (BPL), formalin and ether for inactivation and its impact on antigenicity of AI viruses. A total of nine high and low pathogenic AI viruses belonging to four influenza A subtypes were included in the study. The H5N1 viruses were from the clades 2.2, 2.3.2.1 and 2.3.4. The H9N2 virus included in the study was of the G1 genotype, while the H11N1 and H4N6 viruses were from the Eurasian lineage. The viruses were treated with BPL, formalin and with ether. The confirmation of virus inactivation was performed by two serial passages of inactivated viruses in embryonated chicken eggs. The infectivity of all tested AI viruses was eliminated using 0.1% BPL and 0.1% formalin. Ether eliminated infectivity of all tested low pathogenic AI viruses; however, ether with 0.2% or 0.5% Tween-20 was required for inactivation of the highly pathogenic AI H5N1 viruses. Treatment with BPL, ether and formalin retained virus hemagglutination (HA) titers. Interestingly ether treatment resulted in significant rise in HA titers (P<0.05) of all tested AI viruses. This data demonstrated the utility of BPL, formalin and ether for the inactivation of infectivity of AI viruses used in the study for the preparation of inactivated virus antigens for research and diagnosis of AI.

Effect of different anesthesia methods on erythrocyte immune function in mice

OBJECTIVE

To explore effect of different anesthesia methods and different anesthetics on erythrocyte immune function in mice.

METHODS

The mice were anesthetized by isoflurane and ether inhalation, and also under intraperitoneal anesthesia with sodium pentobarbital and chloral hydrate. Blood was collected from the ventro-cardinal vein. Automatic blood cell analyzer was used for routine blood examination, and the canthine oxidase method was used to measure the superoxide dismutase (SOD) activity. Lipid peroxidation product malondialdehyde (MDA) was measured with TBA, and glutathione peroxidase (GSH-Px) was measured with DTNB, and then the effect of different anesthesia methods and different anesthetics on erythrocyte immune function in mice was observed.

RESULTS

Hct level of chloral hydrate intraperitoneal injection group was significantly higher than the other three groups (P<0.05). And the MDA levels in the pentobarbital sodium group were significantly higher than the other three groups (P<0.05). SOD and GSH-Px of the chloral hydrate and sodium pentobarbital intraperitoneal injection group were significantly lower than the other two groups; RBC-C 3bRR and RBC-ICR of the chloral hydrate and sodium pentobarbital intraperitoneal injection group were significantly lower than the other two groups.

CONCLUSIONS

Different drugs can induce changes in immune function of mice at different levels. Isoflurane and ether have less damage to animal body, while chloral hydrate and sodium pentobarbital intraperitoneal injection have a certain inhibitory effect on the animal body respiratory system and can cause greater damage to the body. Therefore, the reasonable selection and control of anesthetics are very important in order to avoid the experimental errors caused by anesthesia.