Use Of Diethyl Ether Research Articles

The Independent Inventions of General Anesthesia in 19th century Japan and United States

In October of 1804, surgeon Hanaoka Seishū performed the first documented surgery using general anesthesia. Hanaoka’s formulation, a mixture of plant extracts called tsūsensan, was commonly used in Japan, but it had minimal influence elsewhere. It was not until the 1840s that general anesthesia was used outside of Japan. In the eastern United States, four individuals, including dentist William Morton, were independently experimenting with the use of diethyl ether and nitrous oxide as general anesthetics. Unlike Hanaoka’s invention, Morton’s successful use of diethyl ether in a neck tumour removal surgery sparked the rapid development and proliferation of new anesthetic technologies and compounds throughout the world. This paper examines why Hanaoka’s work was not significantly influential outside of Japan, while the later American discoveries achieved global prominence despite being four decades later. Additionally, historical context behind both stories is included. Reasons for this disparity include Japan’s isolationist policy at the time (sakoku) and differences in 19th century Western and Japanese approaches to medical education and research.

Increase of efficiency and reduction of CO and NOx emissions in a stationary compression ignition engine run on Mesua ferrea Linn oil-diesel and diethyl ether

In this study, Mesua ferrea Linn oil (VO, 30% by volume)-diesel (70% by volume) blend (VO30) is used as the fuel to power a direct-injection (DI), single-cylinder compression ignition (CI) diesel engine. This study is focused on the effects of diethyl ether (DEE) as an additive on the performance, combustion and emission characteristics of the engine fuelled by the VO30 blend. DEE is added to the VO30 blend to form two types of ternary blend. One consists of 5% DEE and 95% VO30 by volume (VO30DEE05) and the other consists of 10% DEE and 90% VO30 by volume (VO30DEE10). The study reveals an improvement of 1% to 2.3% in engine thermal efficiency with the use of diethyl ether as additives to the VO-diesel blend. In the same line, both the CO and NOx emission also decreases with the use of DEE additives with the VO-diesel blend. A maximum reduction of 6.9% to 13% CO emission and 3.2% to 11.9% NOx has been achieved with DEE additives as compared to VO30 fuel. The work suggests that DEE can be used effectively as an additive to VO30 fuel which can run CI diesel engines with improved thermal efficiency and reduced emissions.

Heterogeneous Parahydrogen-Induced Polarization of Diethyl Ether for Magnetic Resonance Imaging Applications.

Magnetic resonance imaging (MRI) with the use of hyperpolarized gases as contrast agents provides valuable information on lungs structure and function. While the technology of 129 Xe hyperpolarization for clinical MRI research is well developed, it requires the expensive equipment for production and detection of hyperpolarized 129 Xe. Herein we present the 1 H hyperpolarization of diethyl ether vapor that can be imaged on any clinical MRI scanner. 1 H nuclear spin polarization of up to 1.3 % was achieved using heterogeneous hydrogenation of ethyl vinyl ether with parahydrogen over Rh/TiO2 catalyst. Liquefaction of diethyl ether vapor proceeds with partial preservation of hyperpolarization and prolongs its lifetime by ≈10 times. The proof-of-principle 2D 1 H MRI of hyperpolarized diethyl ether was demonstrated with 0.1×1.1 mm2 spatial and 120 ms temporal resolution. The long history of use of diethyl ether for anesthesia is expected to facilitate the clinical translation of the presented approach.

Effects of Diethyl Ether Introduction in Emissions and Performance of a Diesel Engine Fueled with Biodiesel-Ethanol Blends

Biofuels provide high oxygen content for combustion and do modify properties that influence the engine operation process such as viscosity, enthalpy of vaporization, and cetane number. Some requirements of performance, fuel consumption, efficiency, and exhaust emission are necessary for the validation of these biofuels for application in engines. This work studies the effects of the use of diethyl ether (DEE) in biodiesel-ethanol blends in a DI mechanical diesel engine. The blends used in the tests were B80E20 (biodiesel 80%-ethanol 20%) and B76E19DEE5 (biodiesel 76%-ethanol 19%-DEE 5%). Fossil diesel (D100) and biodiesel (B100) were evaluated as reference fuels. The results revealed similar engine efficiencies among tested fuels at all loads. The use of B100 increased CO and NOx and decreased THC compared to D100 at the three loads tested. B80E20 fuel showed an increase in NOx emission in comparison with all fuels tested, which was attributed to higher oxygen content and lower cetane number. THC and CO were also increased for B80E20 compared to B100 and D100. The use of B76E19DEE5 fuel revealed reductions in NOx and CO emissions, while THC emissions increased. The engine efficiency of B76E19DEE5 was also highlighted at intermediate and more elevated engine load conditions.

Azidophenylselenylation of glycals towards 2-azido-2-deoxy-selenoglycosides and their application in oligosaccharide synthesis

Abstract 2-Amino-2-deoxy-pyranosyl units are important structural components of cell-wall polymers in prokaryotes, fungi and mammals. With respect to the need for development of novel and efficient vaccines and tools for serodiagnosis of infectious diseases, of particular interest are the oligosaccharide cell-wall antigens of pathogenic bacteria and fungi, which comprise 2-amino-2-deoxy-D-glucopyranose and 2-amino-2-deoxy-D-galactopyranose units as α- or β-anomers. Synthesis of N-acylated α-GlcN and α-GalN containing oligosaccharides is a special challenge due to the presence of a participating group at C2 which favors the formation of β- rather than α-glycoside bond. Herein we overview the efficient two-step approach for preparation of 1,2-cis-glycosides of 2-amino-2-deoxy-D-glucopyranose and 2-amino-2-deoxy-D-galactopyranose, which was recently developed in our laboratory. In the first step, an efficient and straightforward azidophenylselenylation procedure of glycals gives phenyl 2-azido-2-deoxy-1-selenoglycosides as versatile glycosyl donors. In the second step, these donors can be efficiently transformed into α- or β-glycosides depending on the choice of the solvent. In acetonitrile, total β-stereocontrol was achieved, and the use of diethyl ether as a solvent favouring α-stereoselectivity of glycosylations with phenyl 2-azido-2-deoxy-1-selenoglycosides. Besides, it was shown, that low reactivity and nucleophilicity of glycosyl acceptors which are glycosylated with phenyl 2-azido-2-deoxy-1-selenogalactosides facilitated the formation of α-GalN derivatives. To date, homogenous azidophenylselenylation of glycals and glycosylation with phenyl 2-azido-2-deoxy-1-seleno-α-D-glycopyranosides can be regarded as most useful tool for introduction of 2-amino-2-deoxy-D-glycopyranoside residues into complex synthetic oligosaccharides.

Diethyl Ether as an Oxygenated Additive for Fossil Diesel/Vegetable Oil Blends: Evaluation of Performance and Emission Quality of Triple Blends on a Diesel Engine

The aim of this work is to analyze the effect of using diethyl ether (DEE) as an oxygenated additive of straight vegetable oils (SVOs) in triple blends with fossil diesel, to be used in current compression ignition (C.I.) engines, in order to implement the current process of replacing fossil fuels with others of a renewable nature. The use of DEE is considered taking into account the favorable properties for blending with SVO and fossil diesel, such as its very low kinematic viscosity, high oxygen content, low autoignition temperature, broad flammability limits (it works as a cold start aid for engines), and very low values of cloud and pour point. Therefore, DEE can be used as a solvent of vegetable oils to reduce the viscosity of the blends and to improve cold flow properties. Besides, DEE is considered renewable, since it can be easily obtained from bioethanol, which is produced from biomass through a dehydration process. The vegetable oils evaluated in the mixtures with DEE were castor oil, which is inedible, and sunflower oil, used as a standard reference for waste cooking oil. In order to meet European petrodiesel standard EN 590, a study of the more relevant rheological properties of biofuels obtained from the DEE/vegetable oil double blends has been performed. The incorporation of fossil diesel to these double blends gives rise to diesel/DEE/vegetable oil triple blends, which exhibited suitable rheological properties to be able to operate in conventional diesel engines. These blends have been tested in a conventional diesel engine, operating as an electricity generator. The efficiency, consumption and smoke emissions in the engine have been measured. The results reveal that a substitution of fossil diesel up to 40% by volume can be achieved, independently of the SVO employed. Moreover, a significant reduction in the emission levels of pollutants and better cold flow properties has been also obtained with all blends tested.

A Review Study on the Using of Diethyl Ether in Diesel Engines: Effects on HC Emissions

This study was compiled from the results of various researches performed on using diethyl ether as a fuel or fuel additive in diesel engines. Three different methods have been used the reduction of the harmful exhaust emissions of diesel engines. The first technique for the reduction of harmful emissions has improved the combustion by modification of engine design and fuel injection system, but this process is expensive and time-consuming. The second technique is the using various exhaust gas devices like catalytic converter and diesel particulate filter. However, the use of these devices affects negatively diesel engine performance. The final technique to reduce emissions and improve diesel engine performance is the use of various alternative fuels or fuel additives. The major pollutants of internal combustion engines are carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), particulate matter (PM) and smoke. The most researches declare that the best way to reduce is the use of various alternative fuels i.e. natural gas, biogas, biodiesel or using additives with alternative fuels or conventional fuels. Therefore, it is very important that the results of various studies on alternative fuels or fuel additives are evaluated together to practical applications. Especially, this study focuses on the use of diethyl ether in diesel engines as fuel or fuel additive in various diesel engine fuels. This review study investigates the effects of diethyl ether additive on the HC emissions.

Determination of δ-hexadecansultone in sodium α-olefinesulphonates and liquid detergents using gas chromatography-mass spectrometry (GC/MS)

Sultones are cyclic esters of hydroxysulfonic acids, which are formed in the process of sulfonation of α-olefins with sulfur trioxide gas. More stable sultones may be present in the final product — an anionic surfactant — sodium α-olefin sulfonate (AOC-Na). AOC-Na is widely used in the production of household chemicals and cosmetic products, including liquid dishwashing detergents. Sultones are strong skin sensitizers, their level in AOC-Na should be strictly controlled and not exceed 5 ppm. Operational and strict control of the sultone content upon AOC-Na production allows timely adjustment at the stage of hydrolysis, which leads to a more complete disclosure of the sultone cycle with the formation of the corresponding olefin sulfonates and hydroxyalkanesulfonates. We propose a method for determining δ-hexadecansultone in liquid dishwashing detergents and sodium α-olefinsulfonates obtained on the basis of α-olefins of C14 – C16 fractions using GC/MS, which provides shortening of sample preparation and keeps the sensitivity with a detection limit of 0.02 mg/kg. The effect of various weakly polar and non-polar organic solvents used for Sultone extraction from AOC-Na and liquid detergent on liquid extraction based on the dispersion of the extractant in an alcohol/water phase is studied. When selecting the solvent we have shown that the use of diethyl ether provided the best extraction of the analyte. Determination of the analyte extraction recovery was performed using the reaction of hydrolysis of the extracted mixture. We specified the operating mode of the device which provided complete separation of the components of the analyzed compounds including the samples of liquid detergent for dishes being a multicomponent mixture of complex composition.

A review study on using diethyl ether in diesel engines: Effects on fuel properties, injection, and combustion characteristics

This study was compiled from the results of various researches performed on using diethyl ether as a fuel or fuel additive in diesel engines. Three different techniques are used, the reduction of the harmful exhaust emissions of diesel engines. The first technique for the reduction of harmful emissions has improved the combustion by modification of engine design and fuel injection system, but this process is expensive and time-consuming. The second technique is the use of various exhaust gas devices like catalytic converter and diesel particulate filter. However, the use of these devices affects negatively diesel engine performance. The final technique to reduce emissions and also improve diesel engine performance is the use of various alternative fuels or fuel additives. The major pollutants of diesel engines are nitrogen oxides and particulate matter. It is very difficult to reduce nitrogen oxides and particulate matter emissions simultaneously in practice. Most researches declare that the best way to reduce these emissions is the use of various alternative fuels i.e. natural gas, biogas, biodiesel, or the use of fuel additives with these alternative fuels or conventional diesel fuel. Therefore, it is very important that the results of various studies on alternative fuels or fuel additives are evaluated together for practice applications. Especially, this study focuses on the use of diethyl ether in diesel engines as fuel or fuel additive in various diesel engine fuels. This review study investigates the effects of diethyl ether on the fuel properties, injection, and combustion characteristics.

Anti-solvent spin-coating for improving morphology of lead-free (CH3NH3)3Bi2I9 perovskite films

Methylammonium iodide bismuthate ((CH3NH3)3Bi2I9) (MIB) perovskite has attracted research attention because of its low toxicity and stability in air. However, MIB perovskite also has its inherent defects, e.g., MIB films have too many pinholes and large indirect band gap. Our group has also done some efforts to successfully improve the performance of MIB-based PSC. One of the recent works focused on the use of diethyl ether (DEE) as anti-solvent to improve film compactness and reduce pinhole defects. The characterization indicated that the films treated by DEE (DEE/MIB) were compact with fewer pinholes. The devices fabricated with DEE/MIB based on mesoporous TiO2 (mp-TiO2) architecture exhibited good performance in terms of Voc (885 mV), Jsc (0.807 mA cm−2), and FF (49.71%), with a power conversion efficiency of 0.343%, which were much higher than that of the contrast test and results of our previous work. The present devices also exhibited superior long-term stability in ambient air (approximately 30% humidity) of more than 200 days.

A review study on the using of diethyl ether in diesel engines: Effects on CO emissions

This study was compiled from the results of various researches performed on using diethyl ether as a fuel or fuel additive in diesel engines. Three different methods have been used the reduction of the harmful exhaust emissions of diesel engines. The first technique for the reduction of harmful emissions has improved the combustion by modification of engine design and fuel injection system, but this process is expensive and time-consuming. The second technique is the using various exhaust gas devices like catalytic converter and diesel particulate filter. However, the use of these devices affects negatively diesel engine performance. The final technique to reduce emissions and improve diesel engine performance is the use of various alternative fuels or fuel additives. The major pollutants of internal combustion engines are carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), particulate matter (PM) and smoke. The most researches declare that the best way to reduce is the use of various alternative fuels i.e. natural gas, biogas, biodiesel or using additives with alternative fuels or conventional fuels. Therefore, it is very important that the results of various studies on alternative fuels or fuel additives are evaluated together to practical applications. Especially, this study focuses on the use of diethyl ether in diesel engines as fuel or fuel additive in various diesel engine fuels. This review study investigates the effects of diethyl ether additive on the CO emissions.

Effect of Diethyl Ether (DEE) on Performances and Smoke Emission of Direct Injection Diesel Engine Fueled by Diesel and Jatropha Oil Blends with Cold EGR System

A widely use of diesel engines increases the scarcity of fossil fuels and air pollution. Jatropha was proved potentially to be used as alternative diesel fuel. However, adding jatropha to diesel fuel increases smoke emissions due to higher their viscosity than diesel fuel. Therefore diethyl ether is substituted into a mixture of diesel and jatropha fuel to solve the problem. However, the use of diethyl ether may have an impact on diesel engine performance. Therefore, the purpose of this study is to evaluate the effect of the addition of diethyl ether on thermal efficiency, exhaust gas temperature and smoke emissions from diesel engines. This study used Isuzu 4JB1 engine equipped with EGR system. The diethyl ether composition in the mixed fuel was varied at 5, 10 and 15% of the total fuel volume. Jatropha in this mixed fuel was set at only 10%. Based on the experimental results, the use of DJ10DEE15 fuel showed the highest increase of 16% in hot EGR systems compared to those without EGR and cold EGR using D100 fuel at full engine load. In addition, the use of DJ10DEE15 fuel with cold EGR system resulted in 8% reduction of exhaust gas temperature compared to the use of D100 fuel at full engine load, while smoke opacity was decreased to 33%.

METHODOLOGICAL RECEPTION FOR DETERMINATION OF DICAMBA RESIDUES IN SOYBEANS BY GC-MS

Introduction. In this paper, there are presented results of investigations on the development and validation of the method for the determination of dicamba residues in import foodstuff (soybeans). The identification and quantitative determination of dicamba are performed by capillary gas-liquid chromatography with mass-selective detection (ionization-electron impact). Material and methods. The stages of sample preparation include four steps as extraction with acidified acetonitrile, followed by the filtration and evaporation; freezing the sample with filtration and evaporation; dissolving the dry residue in a mixture of acetone: water (1:20); purification by repeated redistribution in a system of immiscible solvents under varying the pH of the aqueous medium (pH 9-10: dichloromethane, hexane, pH 2: hexane-tert-butyl methyl ether). The chromatographic measurement was preceded by the derivatization of the acid to the corresponding methyl ester by the treatment with a solution of diazomethane in diethyl ether Results. The lower limit of the quantitative evaluation of dicamba in samples of soybean beans is of 0.01 mg/kg, the signal-to-noise ratio at the detection limit accounts of 20:1. The completeness of extraction of dicamba, established on the basis of analysis of model samples with the introduction of a substance at four points within the defined range, amounted to 85-95%. The average quadratic deviation of the repetition varies in the range of 3.3-4.9%. Discussion. The use of diethyl ether containing dibutylhydroxytoluene (6 ppm) as a stabilizer, as well as the interfering effect of phthalates, led to the formation of poorly resolved peaks of the methyl ester of dicamba, dibutylhydroxytoluene, and dibutyl phthalate. The combination of the use of different methods of data collection (in the scanning mode and in the mode of recording individual ions) made it possible to identify these components. Replacement of the used diethyl ether, as well as variation of chromatographic conditions, for separation of dicamba and phthalate peaks, made it possible to achieve the necessary selectivity of detection of the analyte.

Modeling the effects of cosolvents on biodiesel production

In this study, a mathematical model is developed for predicting the effect of cosolvents on the biodiesel production, by taking into account the fact that the process consists of two liquid phases. The proposed model consists of a detailed chemical kinetic reaction mechanism and the phase equilibrium of the two phases. The experimental data for estimating the reaction rate constants consists of 1580 dynamic concentration data related to cosolvent-free systems. Then, the calculated reaction rate constants are used to model the biodiesel production process in systems containing cosolvents to investigate the cosolvent effects on the process. The average absolute relative deviation of 1.0% for all the experimental data points is a testament to the accuracy of the predictive model. Hence, the model was used to investigate the effect of methanol to oil ratio, the ratio of cosolvent to methanol, and the amount of catalyst on the biodiesel production rate and yield, in the presence of cosolvents tetrahydrofuran and diethyl ether. According to the results, the use of cosolvent leads to increase the reaction rates. In the other words, the process time is reduced; however, the final yield of biodiesel does not change. Comparison between two cosolvents shows that diethyl ether is more appropriate than tetrahydrofuran, because, in the use of diethyl ether, less cosolvent to methanol ratio is needed. Also, the effect of catalyst concentration is similar to the effect cosolvent.

Influence of diethyl ether blend in spark ignition engine performance and emissions operated with gasoline and ethanol

This paper investigates the performance and emission characteristics of single cylinder four stroke petrol engine using unleaded gasoline with combination of ethanol and diethyl ether. Exhaust emissions were analysed for CO, HC, NOx, and CO2 by varying engine torque and engine speed. The result showed that the blend of unleaded gasoline with diethyl ether increases the octane number which in turn increases the power output which leads to increase in the brake thermal efficiency of the engine. The CO, HC, and NOx emissions concentrations in the engine exhaust decreases while the CO2 concentration increases. The use of diethyl ether and ethanol blends as a fuel additive to unleaded gasoline causes an improvement in performance and significant reduction in exhaust emission.

Carving a 1D Co(II)-carboranylcarboxylate system by using organic solvents to create stable trinuclear molecular analogues: complete structural and magnetic studies.

This work presents a straightforward methodology to achieve small linear trinuclear molecules based on the Co(II)-carboranylcarboxylate system obtained by carving a 1D polynuclear analogous system with the use of diethylether. The reaction of the carboranylcarboxylic ligand, 1-CH3-2-CO2H-1,2-closo-C2B10H10 (LH) with different cobalt salts leads to the polynuclear compound [Co2(μ-H2O)(1-CH3-2-CO2-1,2-closo-C2B10H10)4(THF)4], and the polymeric [Co(μ-H2O)(1-CH3-2-CO2-1,2-closo-C2B10H10)2]n(H2O)n. This latter 1D chain has been obtained by an unprecedented synthetic strategy for the isolation of cobalt(ii) compounds. [Co3(μ-H2O)2(1-CH3-2-CO2-1,2-closo-C2B10H10)6(H2O)2(C4H10O)2], is formed by the dissociation of the polymeric structure that forms when a mild coordinating solvent such as diethylether is added. These compounds have been characterized by analytical and spectroscopic techniques. X-ray analysis of and revealed that presents a dinuclear structure whereas is trinuclear; in both cases a six-coordinated Co(II) compound with water molecules bridging each of the two Co(II) centres has been observed. The magnetic properties of and show a weak antiferromagnetic behaviour, respectively, between the Co(II) centres mediated by two carboxylate ligands and a molecule of water.

Impact of oxygenated additives to palm and jatropha biodiesel blends in the context of performance and emissions characteristics of a light-duty diesel engine

In recent years, palm and jatropha biodiesels have been considered as potential renewable energy sources in Malaysia. Therefore, this experimental investigation was conducted to improve the blend of these two biodiesels (20% biodiesel blend, named P20 and J20, respectively) with the help of oxygenated additives. The comparative improvement of P20 and J20 blends with ethanol, n-butanol, or diethyl ether as additives was evaluated in terms of performance and emissions characteristics of a four-stroke single cylinder diesel engine. The final blend consisted of 80% diesel, 15% biodiesel, and 5% additive. Tests were conducted at different speeds (1200–2400rpm) at constant full load conditions. Use of additives significantly improved brake power and brake thermal efficiency (BTE). Compared with P20 blend, the use of diethyl ether as additive increased brake power and BTE by about 4.10% and 4.4%, respectively, at 2200rpm. A similar improvement was observed for J20. The other two additives also improved performance. Although HC emission increased slightly, all blends with additives reduced more NOx and CO emissions than P20 and J20 almost throughout the entire engine test. The use of ethanol as additive reduced CO emission by up to 40%, while the use of diethyl ether as additive reduced NOx emissions by up to 13%. The additives’ oxygen content, volatility, and latent evaporation heat controlled the emissions characteristics of the blends. An analysis of the combustion chamber pressure, temperature and heat release rate of the modified blends revealed interesting features of combustion mechanism, which are indicative of the performance and emissions characteristics. This experiment reveals the potential improvement of palm and jatropha biodiesel blends with the addition of three promising additives.

Selective Synthesis of Glyceryl Tris[9,10‐(threo)‐dihydroxyoctadecanoate

AbstractElaborating novel triacylglyceride (TAG) based polyester hyperbranched unimolecular encapsulating agents represents an original and promising approach to the selective delivery of hydrophobic biologically active compounds. However, selective modification of double bonds in unsaturated TAG to obtain corresponding pure polyhydroxy derivatives with high yields is still a big challenge. Two novel approaches to synthesize the glyceryl tris[9,10‐(threo)‐dihydroxyoctadecanoate] were proposed and tested: (1) via the bromination and nucleophilic substitution of secondary halide functions by oxyacetyl groups followed by the hydrolysis of acetyls, and (2) direct transformation of the double bonds by the reaction with peroxoformic acid in an excess of formic acid, and the removal of formyl protective groups. Glycerol trioleate and natural olive oil were used as starting materials. The first synthetic route allowed for successful preparation of the corresponding polyhalide and polyoxyacetyl products; however, a more effective final deacetylation procedure is required. The second proposed approach showed a very good reproducibility in obtaining hydroxy‐oxyformyl derivatives. The optimal conditions of the reaction involve the use of diethyl ether as a cosolvent and stirring at room temperature for 30 min. To remove the formyl groups, three original procedures using organic solvent medium at room temperature were proposed: in the presence of cesium carbonate in chloroform–methanol mixture, and two methods using hydrochloric acid in chloroform–methanol mixture or in acetone. All three methods were efficient to carry out the deformylation; nevertheless, TAG esters remained stable only with 15–17 % hydrochloric acid in acetone. Simple isolation procedures and high overall yields (95.6 and 94.9 % for both triolein and olive oil, respectively) allow considering the second approach as a promising method to obtain threo‐polyhydroxy derivatives from unsaturated TAG.

Inhalative Anästhetika

Inhaled anesthetics are inhaled via the lungs. They subsequently pass through the alveolocapillary membrane and diffuse into the blood to finally target the central nervous system and induce anesthesia. This principle of anesthesia induction was first described for diethylether in 1847. Nevertheless, the use of diethylether for anesthesia is obsolete and even the use of nitrous oxide (introduced for anesthesia in 1847) is declining in Germany. Almost all modern volatile anesthetics are halogenated methylethylethers in which fluorine is used as a halogen. All of these anesthetics depress myocardial contractility and induce hypotension. Depression of CO2 and hypoxia-induced respiration are other serious side effects. Further side effects are liver and kidney related but they are rare and not induced by anesthetics per se but preferentially by toxic metobolites. Another promising inhalative anesthetic is xenon which fulfils many aspects of an ideal inhalative anesthetic.

Vinylferrocene-Terminated Si(111) Prepared in Diethyl Ether and Dibutyl Ether Grafting Media

Vinylferrocene-terminated Si(111) was prepared by illuminating visible light onto a hydrogen-terminated Si(111) surface that was immersed in either diethyl ether-vinylferrocene or dibutyl ether-vinylferrocene solution. The use of either diethyl ether or dibutyl ether as grafting medium yielded a neutral ferrocenyl monolayer that was electrically connected with the silicon substrate. Both preparation media produce samples that have good electrochemical characteristics e.g., low peak potential separation and linear plot of peak current density with scan rate. The use of dibutyl ether as grafting solution resulted to a fast grafting rate, in which the optimum grafting time for samples with n-type and p-type substrates were 0.5 h and 1 h, respectively. Meanwhile, the use of diethyl ether resulted to the presence of lumps of deposited materials on the grafted surface. Nevertheless, even if these materials may be considered as impurities, these did not distort significantly the electrochemical characteristics of the sample.