Search results for "Activity"
showing 10 items of 7178 documents
ChemInform Abstract: On the Reactivity of Nitrosoimidazoles with Acids (the Cusmano-Ruccia Reaction): A Continuous Source of New Ring-into-Ring Inter…
2014
Abstract An extension of the ‘Cusmano–Ruccia’ reaction is reported. 6-(4-chlorophenyl)-3-methyl-5-nitrosoimidazo[2,1- b ]oxazole by the action of hydrochloric acid gives 3-(4-chlorobenzoyl)-5-methyl-1,2,4-oxadiazole ( 13 ); presumably via ammonium ion, CO 2 and methanol elimination. The relevance of the nature of the atom of the B -ring linked to C-2 of the imidazole for the occurrence of the ring-into-ring interconversion has been once more confirmed.
Transamidation reactions of 2-(2-sulfonylguanidino)acetamides
2007
Abstract The reactivity of a series of sulfonylguanidinoacetamides 2A–E towards amines is reported. Guanidinoacetamides 2A–C, containing the arylsulfonylimino moiety, undergo a facile transamidation to give substituted carboxamides 4A–C, through the imidazolidinone intermediate 3. Acetamide 2D, having a methanesulfonylimino substituent, affords the imidazolidinone 3D and no transamidated carboxamides 4 are detected. In the case of guanidinoacetamide 2E, with a p-nitrobenzenesulfonylimino substituent, a Smiles rearrangement was observed.
ChemInform Abstract: Reactivity and Selectivity of ortho-Metalated Rhodium(II) Complexes in C-H Insertion Reactions of α-Diazo Compounds.
2010
Regioselective intramolecular C−H insertion reactions of α-diazo β-keto esters and α-diazo ketones are mediated by Rh2[OOCR]4-x[PC]x (x = 1, 2; PC = ortho-metalated phosphine; R = CH3, C3F7). In particular, the intramolecular transformation of 1-diazo-5-methyl-3-propyl-2-hexanone catalyzed by Rh2[OOCCH3]2[PC]2 (PC = (C6H4)P(C6H5)2, head-to-tail (H−T) configuration) afforded only the tertiary C−H insertion product. By comparison, no C−H insertion reaction was promoted by doubly metalated complexes with a head-to-head (H−H) configuration. Rh2[OOCR]3[PC] compounds were found to be less suited for these type of reactions.
New Optically Active 4-Alkoxyprolinol Ethers Derived from trans-4-Hydroxy-L-proline
2011
(2S,4R)-trans-4-Hydroxy-L-proline has been used as thechiral-pool source in the efficient syntheses of optically active protected 4-hydroxyprolinols. After N-acyl protection andester formation, the first ether moiety was introduced maintaining the chiral centre adjacent to the ester. Then, reduction of the ester delivered the corresponding carbinol, which had to be alkylated selectively to avoid side reactions with the N-protecting group. Finally, the N-acyl function was removed to generate the target methyl and tert-butyl ethers displaying defined substitution patterns. The so-formed optically active 4-alkoxyprolinol ethers can be used as core fragments in biologically active compounds or …
The Aluminyl Anion : A New Generation of Aluminium Nucleophile
2020
Trivalent aluminium compounds are well known for their reactivity as Lewis acids/electrophiles, a feature that is exploited in many pharmaceutical, industrial and laboratory-based reactions. Recently, a series of isolable aluminium(I) anions ('aluminyls') have been reported, which offer an alternative to this textbook description: these reagents behave as aluminium nucleophiles. This minireview covers the synthesis, structure and reactivity of aluminyl species reported to date, together with their associated metal complexes. The frontier orbitals of each of these species have been investigated using a common methodology to allow for a like-for-like comparison of their electronic structure a…
Maturation of a Key Resource – The Germanium-68/Gallium-68 Generator: Development and New Insights
2011
(68)Ge/(68)Ga radionuclide generators have been investigated for almost fifty years, since the cyclotron-independent availability of positron emitting (68)Ga via the (68)Ge/(68)Ga system had always attracted researches working in basic nuclear chemistry as well as radiopharmaceutical chemistry. However, it took decades and generations of research (and researchers) to finally reach a level of (68)Ge/(68)Ga radionuclide generator designs adequate to the modern requirements of radiometal labelling chemistry. Nevertheless, most of the existing commercial generator systems address aspects of (68)Ge breakthrough and safe synthesis of (68)Ga radiopharmaceuticals by adopting eluate post-processing …
ChemInform Abstract: Unique Reactivity of Fluorinated Molecules with Transition Metals
2015
Organofluorine and organometallic chemistry by themselves constitute two potent areas in organic synthesis. Thus, the combination of both offers many chemical possibilities and represents a powerful tool for the design and development of new synthetic methodologies leading to diverse molecular structures in an efficient manner. Given the importance of the selective introduction of fluorine atoms into organic molecules and the effectiveness of transition metals in C-C and C-heteroatom bond formation, this review represents an interesting read for this aim.
Novel Lymphocyte-Independent Antitumor Activity by PD-1 Blocking Antibody against PD-1+ Chemoresistant Lung Cancer Cells
2022
Abstract Purpose: Antibodies against the lymphocyte PD-1 (aPD-1) receptor are cornerstone agents for advanced non–small cell lung cancer (NSCLC), based on their ability to restore the exhausted antitumor immune response. Our study reports a novel, lymphocyte-independent, therapeutic activity of aPD-1 against NSCLC, blocking the tumor-intrinsic PD-1 receptors on chemoresistant cells. Experimental Design: PD-1 in NSCLC cells was explored in vitro at baseline, including stem-like pneumospheres, and following treatment with cisplatin both at transcriptional and protein levels. PD-1 signaling and RNA sequencing were assessed. The lymphocyte-independent antitumor activity of aPD-1 was explored in…
Pedagoģiskais process vecākā pirmsskolas vecuma bērnu fiziskās aktivitātes sekmēšanai
2018
Tēma: Pedagoģiskais process vecākā pirmsskolas vecuma bērnu fiziskās aktivitātes sekmēšanai. Darba autore – Karlīna Kvēpa Darba mērķis: Teorētiski un praktiski noskaidro vai bērniem apmeklējot PII tiek piedāvātas pietiekamas fiziskās aktivitātēs. Pētījuma jautājums: Vai pirmsskolas izglītības iestādes piedāvāto fizisko aktivitāšu intenstitāte, nodrošina bērniem vajadzīgo kustību daudzumu? Pētījuma metodes: Tika izanalizēta literatūra par bērna attīstību, fiziskajām aktivitātēm, pirmsskolas izglītības iestādes lomu bērnu fiziskajā audzināšanā. Pētījums tika veikts pirmsskolas izglītības iestādē X. Tajā piedalījās 6-7 gadus veci bērni-12 puiši un 12 meitenes- kuri ikdienā apmeklē pirmsskolas …
Associations of age, body size, and maturation with physical activity intensity in different laboratory tasks in children
2021
We investigated the associations of age, sex, body size, body composition, and maturity with measures of physical activity (PA) intensity in children. PA intensity was assessed using VO2 as % of VO2reserve or VO2 at ventilatory threshold (VT), muscle activity measured by textile electromyography, mean amplitude deviation (MAD) measured by accelerometry, and metabolic equivalent of task (MET) during laboratory activities.Age, stature, and muscle mass were inversely associated with VO2 as % of VO2reserve and % of VT, during walking or running on a treadmill for 4, 6, and 8 km/h (Spearman r = -0.645 to -0.358). Age was inversely associated with MAD during walking on treadmill for 4 km/h (r = -…