Search results for "CoV"

Transpiration and Water Use of an Irrigated Traditional Olive Grove with Sap-Flow Observations and the FAO56 Dual Crop Coefficient Approach

2021

The SIMDualKc model was applied to evaluate the crop water use and the crop coefficient (Kc) of an irrigated olive grove (Olea europaea L.) located in Sicily, Italy, using experimental data collected from two crop seasons. The model applies the FAO56 dual Kc approach to compute the actual crop evapotranspiration (ETc act) and its components, i.e., the actual tree transpiration (Tc act), obtained through the basal crop coefficient (Kcb), and soil evaporation according to an evaporation coefficient (Ke). Model calibration was performed by minimizing the difference between the predicted Tc act and the observed daily tree transpiration measured with sap flow instrumentation (TSF field) acquired…

Acute cholecystitis during COVID-19 pandemic: a multisocietary position statement

2020

AbstractFollowing the spread of the infection from the new SARS-CoV2 coronavirus in March 2020, several surgical societies have released their recommendations to manage the implications of the COVID-19 pandemic for the daily clinical practice. The recommendations on emergency surgery have fueled a debate among surgeons on an international level.We maintain that laparoscopic cholecystectomy remains the treatment of choice for acute cholecystitis, even in the COVID-19 era. Moreover, since laparoscopic cholecystectomy is not more likely to spread the COVID-19 infection than open cholecystectomy, it must be organized in such a way as to be carried out safely even in the present situation, to gu…

Acute effects of cold pack on mechanical properties of the quadriceps muscle in healthy subjects.

2012

Purpose: To examine the effects of local cooling on mechanical properties of the quadriceps muscle in healthy subjects. Subjects: Thirty-nine healthy subjects (27 women, 12 men, mean age 39, range 20e62) volunteered. Methods: A cold gel pack was applied to the quadriceps muscle for 20 min. Properties were quantified by analyzing the frequency (tension), decrement (elasticity) and stiffness of damped oscillations and the compliance of the muscle before, immediately after and after 15-min after cooling. Results: The largest responses immediately after cooling were seen in the oscillation decrement parameter, 7.9 (3.7e12.1) %, and in the compliance parameter, � 7.5 (� 9.8 to � 5.3) %. Response…

Analgetische Wirkstoffe, 11. Mitt. Diacylderivate des Butyroguanamins

1986

Die Synthese vono-Acylamino-β-dimethylamino-propiophenonen. 4. Mitt.: Synthese der primären Mannich-Basen

1972

Das durch Umsetzung von 2-Acetamino-β-dimethylamino-propiophenon (IVb) mit Dibenzylamin darstellbare 2-Acetamino-β-dibenzylamino-propiophenon (XXVII) kann hydrogenolytisch mit tels Palladium-Aktivkohle in die entsprechende, nur am aromatischen Stickstoff acetylierte primare Mannich-Base ubergefuhrt werden. In analoger Weise sind auch in 5-Stellung substituierte Derivate des 2-Acetamino-β-amino-propiophenons (XXVIII) zuganglich. Synthesis of 2-Acylamino-β-amino-propiophenones 2-Acetamino-β-dibenzylamino-propiophenone (XXVII) and its derivatives, substituted in 5-position, can be synthetized by reaction of 2-acetamino-β-dimethylamino-propiophenone (IVb) with dibenzylamine. By hydrogenolysis i…

An efficient esterification of pullulan using carboxylic acid anhydrides activated with iodine

2010

Received August 9, 2009Accepted January 12, 2010Published online February 11, 2010Acylation of alcohols (esterification) with anhydride is an important and routinely utilizedtransformation in organic synthesis. Iodine is a cheap and one of the most powerful anhy-dride activating agents for the esterification of alcohols. Therefore, an efficient and cost ef-fective method was developed for the acylation of pullulan polysaccharide by using differentacid anhydrides activated with iodine. A series of organo-soluble pullulan esters were suc-cessfully synthesized, purified and characterized. Under solvent free conditions, it was feasi-ble to fabricate pullulan nonaacetate and pullulan stearate. A…

Antikonvulsiva, 1. Mitt. Thiocarbamoylbutyroguanamine

1986

Durch Anlagerung von Butyroguanamin (1) an die Isothiocyanate 2a-c sind die Thiocarbamoylbutyroguanamine 3a-c zuganglich. Auf dem Wege der Acylierung von 3 sind unsymmetrisch substituierte Butyroguanamine 4 erhaltlich. Unter den neu entwickelten Verbindungen zeichnet sich insbesondere 3c durch antikonvulsive, fungizide und die Magensauresekretion hemmende Wirkungen aus. Anticonvulsivic Agents, I: Thiocarbamoylbutyroguanamines The thiocarbamoylbutyroguanamines 3a-c are accessible by addition of butyroguanamine (1) to the isothiocyanates 2a-c. Unsymmetrically substituted butyroguanamines 4 are obtainable by acylation of 3. Among the newly prepared compounds, 3c in particular exhibits anticonv…

2014

Carbon-centered radicals represent highly useful reactive intermediates in organic synthesis. Their nucleophilic character is reflected by fast additions to electron deficient C=X double bonds as present in iminium ions or cationic heterocycles. This review covers diverse reactions of preformed or in situ-generated cationic substrates with various types of C-radicals, including alkyl, alkoxyalkyl, trifluoromethyl, aryl, acyl, carbamoyl, and alkoxycarbonyl species. Despite its high reactivity, the strong interaction of the radical’s SOMO with the LUMO of the cation frequently results in a high regioselectivity. Intra- and intermolecular processes such as the Minisci reaction, the Porta react…

Highly Diastereoselective Michael Reaction of (S)‐Mandelic Acid Enolate. Chiral Benzoyl Carbanion Equivalent Through an Oxidative Decarboxylation of …

2002

The reaction of the lithium enolate of the 1,3-dioxolan-4-one derived from optically active (S)-mandelic acid and pivalaldehyde with α,β-unsaturated carbonyl compounds proceeds readily to give the corresponding Michael adducts in good yields and high diastereoselectivity. Subsequent basic hydrolysis of the acetal and oxidative decarboxylation of the α-hydroxyacid moiety provides chiral 2-substituted 1,4-dicarbonyl compounds with very high enantiomeric excesses.

Enantioselective synthesis of 2-substituted-1,4-diketones from (S)-mandelic acid enolate and α,β-enones

2006

[EN] An approach for the synthesis of chiral non-racemic 2-substituted-1,4-diketones from (S)-mandelic acid and ¿,ß-enones has been developed. The reaction of lithium enolate of the 1,3-dioxolan-4-one derived from optically active (S)-mandelic acid and pivalaldehyde with ¿,ß-unsaturated carbonyl compounds proceeds readily to give the corresponding Michael adducts in good yields and with high diastereoselectivities. The addition of HMPA (3 equiv) reverses and strongly enhances the diastereoselectivity of the reaction. A change in the reaction mechanism from a lithium catalyzed to the one where catalysis has been suppressed by coordination of HMPA to lithium is proposed to explain these resul…