bluuebunny/crossref_metadata_2025_split huggingface dataset:
An entry into the novel tetracyclic system 6H‐pyrido[1′,2′:4,5]pyrazino[1,2‐a]benzimidazole. Synthesis and conformational study of the 1,2,3,4,13,13a‐hexahydro‐3,3‐ethylenedioxy and 3‐ketone derivatives
Authors: Compernolle Frans , Saleh M.‐Ashty , Toppet Suzanne , De Buysser Wim , Hoornaert Georges 
Published: May 2009

AbstractThe synthesis of the tetracyclic title compounds, acetal 5 and ketone 6, is presented. The key step, formation of the imidazole ring to give compound 5, involved the acid catalysed dehydration of the 2‐(o‐aminophenyl)lactam 7b. This was generated from lactam 4 via N‐substitution with o‐nitrofluorobenzene and reduction of the nitro group. Deprotection of acetal 5 afforded ketone 6 which through a temperature dependence study of vicinal coupling constants was shown to occur as an equilibrium of trans‐ and cis‐fused forms A and B.
2‐Aryl‐substituted 4H‐3,1‐benzoxazin‐4‐ones as novel active substances for the cardiovascular system
Authors: Rose Ulrich 
Published: May 2009

Abstract4H‐3,1‐Benzoxazin‐4‐ones of the structural types 3 and 4 are accessible by cyclization reactions. The introduction of the phosphonate group was achieved by way of Wohl‐Ziegler bromination and subsequent Michaelis‐Arbuzow reaction with a trialkyl phosphite. Pharmacological investigations on isolated left atria, ileum specimens, and Langendorff hearts as well as in vivo circulatory studies on anesthetized rats revealed that the phosphonates 4 exert calcium antagonistic effects. Whereas 2‐(arylvinyl)benzoxazinones gave rise to pronounced negative inotropic effects, compound 3e exhibited relaxing effects on smooth musculature in particular and markedly increased the coronary flow through Langendorff hearts.
Improved syntheses of thieno[2,3‐b]‐ and [3,2‐b]‐fused naphthyridines
Authors: Björk Patrick , Aakermann Torunn , Hörnfeldt Anna‐Britta , Gronowitz Salo 
Published: May 2009

AbstractThe preparation of eight isomeric thieno[2,3‐b]‐ and [3,2‐b]‐fused naphthyridines [1] was improved through the Pd(0) catalyzed cross‐coupling of 3‐formyl‐4‐iodopyridine, 2‐formyl‐3‐iodopyridine, 3‐bromo‐4‐formylpyridine and 2‐bromo‐3‐formylpyridine with t‐butyl N‐(2‐trimethylstannyl‐3‐thienyl)car‐bamate and t‐butyl N‐(3‐trimethylstanny‐2‐thienyl)carbamate.
Synthesis of 2H‐pyrano[2,3‐b]quinolines. Part II. Preparation and 1H‐nmr investigations of 4‐hydroxy‐2‐methyl‐3,4‐dihydro‐2H‐pyrano[2,3‐b]quinolines
Authors: Cziáky Zoltán , Szabó Zoltán 
Published: May 2009

AbstractDiastereoisomers of 4‐hydroxy‐2‐methyl‐3,4‐dihydro‐2H‐pyrano[2,3‐b]quinolines 8 and 9 were synthesized starting from the appropriate 2‐chloroquinoline‐3‐carboxaldehydes 1. The relative configuration of the 1,3‐diol intermediates 4 and 5 was determined on the basis of the 13C‐nmr spectra of their acetonides. The relative stereochemistry of title compounds was confirmed by using homonuclear NOE and selective decoupling experiments, as well as by analysis of the coupling patterns observed in their 1H‐nmr spectra.
A versatile synthesis of functionalised 2‐aminoquinolines by mercury controlled cyclisation of 2‐vinylphenylthioureas
Authors: Wiggall Kenneth J. , Richardson Stewart K. 
Published: May 2009

Abstract4‐(4‐Hydroxyphenyl)‐2‐phenylamino‐1,8‐naphthyridine was prepared via cyclisation of N‐phenyl‐N′‐3‐(4‐hydroxyphenethen‐1‐yl)pyridin‐2‐ylthiourea in the presence of mercuric oxide. Derivatives of 4‐methyl‐2‐aminoquinolines were prepared in a similar manner from 2‐vinylphenylthioureas.
Syntheses of new 2‐hydroxythiazol‐5‐yl and 3‐hydroxy‐1,2,4‐triazol‐5‐ylphosphonic acids as potential cyclic spatial mimics of glyphosate
Authors: Anderson D. Keith , Deuwer David L. , Sikorski James A. 
Published: May 2009

AbstractA low temperature lithiation/phosphorylation procedure has been successfully applied to 2‐methoxythia‐zole and 1‐substituted 3‐alkoxy or 3‐silyloxy‐1H‐1,2,4‐triazoles to provide a series of novel hydroxy‐substituted heterocyclic phosphonates and phosphonic acids as potental cyclic spatial mimies of glyphosate.
The potential utility of homoacylation through the pummerer rearrangement‐intermediates. A direct approach to the 1‐benzene‐sulfonyl‐4‐keto‐8‐methoxy‐1,2,2a,3,4,5‐hexahydrobenz‐[cd]indole via intra‐homoacylation
Authors: Stamos Ioannis K. , Kotzamani Heleni K. 
Published: May 2009

AbstractA convenient synthesis of tricyclic ketone 7 is described based on an intra‐homoacylation via a Pummerer intermediate. The indole 3, was both annelated and functionalized for the next step through its protected indoline 4 using the single reagent dimsyllithium. The produced sulfoxide 5 generated the thionium ion intermediate upon treatment with trifluoroacetic anhydride, which subsequently underwent intramolecular cyclization to ketone 6 in the presence of a Lewis acid.
Synthesis of some new imidazo[1,2‐a]pyrimidin‐5(1H)‐ones as potential antineoplastic agents
Authors: Badawey El‐Sayed , Kappe Thomas 
Published: May 2009

AbstractSome substituted imidazo[1,2‐a]pyrimidin‐5(1H)‐ones have been synthesized via the reaction of 2‐aminoimidazole sulfate with some β‐keto esters, diethyl ethoxymethylenemalonate and ethyl ethoxymethylenecyanoacetate. Several compounds were screened for their in vitro antineoplastic and anti‐HIV activity but were inactive.
Regioselective conversion of 3‐cyano‐6‐hydroxy‐2‐pyridones into 3‐cyano‐6‐amino‐2‐pyridones
Authors: Katritzky Alan R. , Rachwal Stanislaw , Smith Terrance P. 
Published: May 2009

AbstractThe reaction of a tautomeric mixture of 1‐butyl‐1,2‐dihydro‐6‐hydroxy‐4‐methyl‐2‐oxopyridine‐3‐carbonitrile and its 2‐hydroxy‐6‐oxo analog with phosphorus oxychloride gave 1‐butyl‐6‐chloro‐1,2‐dihydro‐4‐methyl‐2‐oxopyridine‐3‐carbonitrile (68%) and 1‐butyl‐2‐chloro‐1,6‐dihydro‐4‐methyl‐6‐pyridine‐3‐car‐bonitrile (3%). Both chloropyridones were converted to their corresponding aminopyridones by reaction with liquid ammonia. Strong support for the molecular structure of 6‐amino‐1‐butyl‐1,2‐dihydro‐4‐methyl‐2‐oxopyridine‐3‐carbonitrile was obtained on the basis of nmr techniques.
Antineoplastic anthraquinones. II. Design and synthesis of 1,2‐Heteroannelated anthraquinones
Authors: Chang Pong , Chen Chia‐Fu 
Published: May 2009

AbstractBased on the “2‐phenyinaphthalene‐type” structural pattern hypothesis, a number of heterocycle‐fused anthraquinones were designed by taking morindaparvin‐A (2a) as the lead structure. The compounds we synthesized and tested for antineoplastic activity include 1,2‐alkylenedioxyanthraquinone, naphtho [2,3‐f]‐quinoxaline‐7,12‐dione, anthra[1,2‐d]imidazole‐6,11‐dione and naphtho[2,3‐f]quinoxaline‐7,12‐dione derivatives. Most of the synthesized anthraquinones possessed various degrees of anticancer activity. One of these compounds, 2‐chloromethyl‐1H‐anthra[1,2‐d]imidazole‐6,11‐dione (4b), exhibited cytotoxic activity against all tested human carcinoma cell lines.
Streptonigrin and related compounds. 6. Synthesis and activity of some quinoxaline analogues
Authors: Rao Koppaka V. , Rock Charles P. 
Published: May 2009

AbstractStreptonigrin is an antitumor antibiotic with significant in vitro and in vivo antitumor activity spectrum. Besides the total syntheses, numerous syntheses of the partial structures have been carried out in order to assess the structural requirements for the activity. The present publication deals with the synthesis of selected quinoxalinequinones to study the effect of changes in the B‐ring of streptonigrin.A convenient 3‐step synthesis of the required quinoxaline starting material that provides the necessary control of the desired substituent pattern is described. A series of 7‐amino‐6‐methoxy‐quinoxalinequinones were prepared in which substitution at 3‐ was varied (from H to Cl, OCH3, CN, COOCH3 and OH). A few selected 6‐aminoquinones (with 6‐NH2 and 6‐piperidinyl) were also prepared for comparison. The quinones (18) were tested in three different in vitro test systems: cytotoxicity to mouse leukemia (L‐1210) cells, antibacterial activity against Bacillus subtilis and inhibition of root growth. Several of the aminoquinones showed significant activity in comparison to that shown by streptonigrin.
Synthesis of 3‐methyl‐substituted pyrazolotriazolopyrimidin‐4‐one and pyrazolothiazolopyrimidin‐4‐one derivatives
Authors: Guccione Salvatore , Scolaro Luigi Monsù , Russo Filippo 
Published: May 2009

AbstractAs a part of a research on anti‐inflammatory analgesic compounds 3‐methyl substituted pyrazolotria‐zolopyrimidin‐4‐one and pyrazolothiazolopyrimidin‐4‐one derivatives were prepared by previously reported procedures. None of the compounds showed improved activity when compared with the previously reported unsubstituted analogs.
Synthesis and fluorescence properties of novel benzo[a]phenoxazin‐5‐one derivatives
Authors: Long Jiang , Wang Yong‐Mei , Matsuura Teruo , Meng Ji‐Ben 
Published: May 2009

AbstractThirteen, benzo[a]phenoxazin‐5‐one derivatives 3a‐m were synthesized from 4‐nitrosoaniline hydrochlorides 1a‐m and ethyl 1,3‐dihydroxynaphthoate 2 and their fluorescence properties were discussed in terms of the electronic effect of substituents. A coupling reaction was carried out with 6‐carbethoxy‐9‐N‐(2‐hydroxyethyl)‐N‐methylamino‐5H‐benzo[a]phenoxazin‐5‐one (3k) and acetyl‐DL‐alanine to afford N‐[(6‐carbethoxy‐5‐oxo‐5H‐benzo[a]phenoxazin)‐9‐yl]‐N‐methylaminoethylene acetyl‐DL‐alanine ester (4).
Synthesis and complete1Hand13C assignments of thiazolo[3,2‐a]quinolinium derivatives
Authors: Cox Osvaldo , Prieto José A. , Ramírez Lorna , Rodríguez Margarita , Martínez José R. 
Published: May 2009

AbstractSeveral hitherto unknown thiazolo[3,2‐a]quinolinium salts derivatives were prepared and characterized. Two‐dimensional high field nmr methods were employed to make complete assignments of the proton and carbon nmr spectra for these compounds.
Electrochemical and electron spin resonance studies of selected benzazolo[3,2‐a]quinolinium salts
Authors: Cox Osvaldo , Dumas José A. , Rivera Luis A. , García Carmelo , Alegria Antonio E. 
Published: May 2009

AbstractThe electrochemical reduction of the chloride or perchlorate salts of benzazolo[3,2‐a]quinolinium ion and several of its analogues is reported. The compounds studied are the perchlorate salt of 3‐nitrobenzothiazolo‐and 3‐nitro‐9‐methoxybenzothiazolo[3,2‐a]quinolinium, and the chloride salts of 7‐ethyl‐, 3‐nitro‐7‐methyl‐, 3‐nitro‐7‐ethyl‐, 3‐nitro‐7‐isopropyl‐, 3‐nitro‐7‐butyl‐ and 3‐nitro‐7‐benzylbenzimidazolo[3,2‐a]‐quinolinium, respectively. Cyclic voltammetry of the corresponding 3‐nitrobenzothiazolo[3,2‐a]quinolinium derivatives inN,N‐dimethylformamide shows an irreversible peak potential at ‐0.6 and a quasi‐reversible peak at ‐(1.2–1.3) volts, respectively, relative to the standard calomel electrode. In contrast, the corresponding 3‐nitrobenzimidazolo[3,2‐a]quinolinium derivatives show, in general, reversible peaks at near ‐0.8 and ‐(1.2–1.4) volts, respectively. Upon electrolytic reduction, only the nitro‐substituted derivatives produced observable electron paramagnetic resonance electron spin resonance spectra. This observation is explained in terms of the stabilization of the radicals produced by the nitro group. Theoretical MM+/AM1/UHF calculations support the idea that the larger nitrogen splitting is caused by N‐12 and the minor splittings by N‐7 in the benzimidazolo[3,2‐a]quinolinium ion series.
A new synthesis of symmetrical 2,5‐disubstituted 1,3,4‐oxadiazoles
Authors: Bentiss Fouad , Lagrenée Michel 
Published: May 2009

AbstractSeveral new 2,5‐disubstituted 1,3,4‐oxadiazoles have been synthesized in good yields by reaction of aromatic acids with hydrazine dihydrochloride in a mixture of orthophosphoric acid, phosphorus pentoxide and, in general, with addition of phosphorus oxychloride to the reaction mixture. The structures of new oxadiazoles derivatives were confirmed by analytical and spectral data.
The basicity of pyridine and its tendency towards cationic homoconjugation in non‐aqueous media
Authors: Chmurzyński Lech 
Published: May 2009

AbstractAcid dissociation constant, pKa, of protonated pyridine, determined in the polar protophobic aprotic solvent, acetone, has been compared with pKa values of the pyridinium ion in a variety of other polar solvents including aprotic protophobic ones, acetonitrile, benzonitrile, nitrobenzene, nitromethane, and propylene carbonate, in the protophilic aprotic dimethyl sulfoxide and N,N‐dimethylformamide, as well as in the amphiprotic methanol. On the basis of the set of these pKa values, the effect of the medium on the basicity of pyridine is discussed. Further, based on the cationic homoconjugation constants of pyridine conjugated with the pyridinium cation in the non‐aqueous solvents, the tendency of pyridine towards homoconjugation reactions has also been discussed. Finally, both the basicity of pyridine and its tendency towards cationic homoconjugation has been compared with analogous properties of pyridine N‐oxide.
1,3‐Dipolar cycloaddition of nitrile oxides to methyl 3‐(p‐nitrobenzoyloxy)acrylate: Methyl 3‐(p‐nitrobenzoyloxy)acrylate as a methyl propiolate equivalent with reverse regioselectivity
Authors: Zong Kyukwan , Shin Seung Il , Jeon Dong Ju , Lee Jung No , Ryu Eung K. 
Published: May 2009

Abstract3‐Aryl‐4‐methoxycarbonylisoxazoles were prepared from the reaction of a variety of substituted benzonitrile oxides with methyl 3‐(p‐nitrobenzoyloxy)acrylate in moderate to good yields.
Synthesis of some polycyclic 1,2,4‐triazines disposing of acidic N‐H group
Authors: Hlaváč Jan , Slouka Jan , Hradil Pavel , Lemr Karel 
Published: May 2009

Abstract7‐(6‐Azauracil‐5‐yl)‐isatin 1 was converted through its thiosemicarbazone 2 to 6‐(6‐azauracil‐5‐yl)‐2,3‐dihydro‐5H‐1,2,4‐triazino[5,6‐b]indol‐3‐thione 3 and through the thiosemicarbazone of appropriate isatinic acid to 2‐(2‐thio‐6‐azauracil‐5‐yl)‐6‐(6‐azauracil‐5‐yl)‐aniline 4. The course of the cyclocondensation of this compound was studied and the reaction was found to proceed in both possible ways, resulting in a mixture of compound 3 and regioisomer 6‐(2‐thio‐6‐azauracil‐5‐yl)‐2,3‐dihydro‐5H‐1,2,4‐triazino[5,6‐b]‐indol‐3‐one 5. Substituted aniline 4 was oxidized to 2,6‐bis‐(6‐azauracil‐5‐yl)‐aniline 7, which served for the preparation of hydrazone 8, cyclization of which led to 1‐[2,6‐bis‐(6‐azauracil‐5‐yl)‐phenyl]‐6‐azauracil‐5‐carbonitrile 9. This is the first tricyclic 6‐azauracil with vicinal arrangement of 6‐azauracil rings.
Efficient synthesis of 1‐alkyl(aralkyl)‐3‐methyl(ethyl)imidazolium halides: Precursors for room‐temperature ionic liquids
Authors: Dzyuba Sergei V. , Bartsch Richard A. 
Published: May 2009

AbstractFacile preparation of 1‐alkyl(aralkyl)‐3‐methyl(ethyl)imidazolium bromides and chlorides is reported. With short reaction times, the desired salts are obtained without purification in high yields from equimolar amounts of reactants.
Influence of bone adaptation on tendon‐to‐bone healing in bone tunnel after anterior cruciate ligament reconstruction in a rabbit model
Authors: Wen Chun‐Yi , Qin Ling , Lee Kwong‐Man , Wan‐Nar Wong Margaret , Chan Kai‐Ming 
Published: May 2009

AbstractAnterior cruciate ligament (ACL) reconstruction with placement of grafted tendon in bone tunnel is a common surgical procedure. Bone tunnel creation may result in stress shielding of postero‐lateral regions of tibial tunnel. The present study was designed to characterize the changes of peri‐graft bone and compare with tendon‐to‐bone (T‐B) healing in spatial and temporal manners after ACL reconstruction in rabbit. Surgical reconstruction using digital extensor tendon in bone tunnel was performed on 48 rabbits. Twelve rabbits were sacrificed at 0, 2, 6, and 12 weeks postoperatively for radiological and histological examinations. Bone mass and microarchitecture at the anterior, posterior, medial, and lateral regions of tunnel wall at distal femur and proximal tibia were evaluated. Using peripheral quantitative computed tomography, a 26, 22, and 42% decrease in bone mineral density (BMD) relative to baseline was present in the medial region of the femoral tunnel and the posterior and lateral regions of the tibial tunnel, respectively, at week 12 postoperatively (p < 0.05). It was accompanied by a decrease in trabecular number and increase in trabecular spacing, the shift of platelike to rodlike trabeculae, and loss of anisotropy under micro‐computed tomography evaluation. This finding was echoed by histology showing increased osteoclastic activities and poor T‐B healing in these regions. In conclusion, the postoperative bone loss and associated poor T‐B healing was region‐dependent, which may result from adaptive changes after tunnel creation. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1447–1456, 2009
Irbesartan: FTIR and Raman spectra. Density functional study on vibrational and NMR spectra
Authors: Franca Carlos A. , Etcheverry Susana B. , Pis Diez Reinaldo , Williams Patricia A. M. 
Published: May 2009

AbstractArterial hypertension is a very common disease, which is treated with different medications such as Irbesartan. This compound is a nonpeptide antagonist of the receptor of the enzyme angiotensin II. The infrared and Raman spectra of this compound were recorded and discussed assisted with density functional theory using the 6‐31G** basis set and animated pictures. Irbesartan exists in two tautomeric forms which can be isolated in the solid state. The vibrational study has been recorded using a mixture of both forms. 13C, 15N and 1H NMR theoretical studies have been performed and compared with previously reported experimental data. Theoretical calculations allowed the determination of the main features of the A and B tautomers of Irbesartan both in the vibrational studies and in the NMR spectroscopy. Copyright © 2009 John Wiley & Sons, Ltd.
Shear‐reversibly Crosslinked Alginate Hydrogels for Tissue Engineering
Authors: Park Honghyun , Kang Sun‐Woong , Kim Byung‐Soo , Mooney David J. , Lee Kuen Yong 
Published: May 2009

AbstractInjectable delivery vehicles in tissue engineering are often required for successful tissue formation in a minimally invasive manner. Shear‐reversibly crosslinked hydrogels, which can recover gel structures from shear‐induced breakdown, can be useful as an injectable, because gels can flow as a liquid when injected but re‐gel once placed in the body. In this study, injectable and shear‐reversible alginate hydrogels were prepared by combination crosslinking using cell‐crosslinking and ionic crosslinking techniques. The addition of a small quantity of calcium ions decreased the number of cells that were required to form cell‐crosslinked hydrogels without changing the shear reversibility of the system. The physical properties and gelation behavior of the gels were dependent on the concentration of both the cells and the calcium ions. We found that gels crosslinked by combination crosslinking methods were effective to engineer cartilage tissues in vivo. Using both ionic and cell‐crosslinking methods to control the gelation behavior may allow the design of novel injectable systems that can be used to deliver cells and other therapeutics for minimally invasive therapy, including tissue engineering.magnified image
Self‐Assembled Polythiophene‐Based Nanostructures: Numerical Studies
Authors: Gus'kova Olga A. , Khalatur Pavel G. , Khokhlov Alexei R. 
Published: May 2009

AbstractThis review highlights recent advances achieved by different groups with various molecular simulation approaches for the prediction and fine‐tuning of the supramolecular organization of thiophene derivatives, oligo‐ and polythiophenes. The focus is on functionalized oligo‐ and polythiophenes, including bio‐inspired thiophene/peptide copolymers (“molecular chimeras”). The subject matter of the article is divided up into subsections covering electronic and structural properties of single molecules, solution and solid‐state self‐assembly, amorphous polythiophene and polymer blends, thiophene‐based nanomechanical devices, self‐organization on substrates and applications. A number of examples are used to provide experimental data with which to compare the theoretical predictions.magnified image
k‐Splittable delay constrained routing problem: A branch‐and‐price approach
Authors: Truffot Jérôme , Duhamel Christophe , Mahey Philippe 
Published: May 2009

AbstractRouting problems, which include a QoS‐based path control, play a key role in broadband communication networks. We analyze here an algorithmic procedure based on branch‐and‐price algorithm and on the flow deviation method to solve a nonlinear k‐splittable flow problem. The model can support end‐to‐end delay bounds on each path and we compare the behavior of the algorithm with and without these constraints. The trade‐off between QoS guarantees and CPU time is clearly established and we show that minimizing the average delay on all arcs will yield solutions close to the optimal one at a significant computational saving. © 2009 Wiley Periodicals, Inc. NETWORKS, 2010
Phenoxy radical detection using31P NMR spin trapping
Authors: Zoia Luca , Argyropoulos Dimitris S. 
Published: May 2009

AbstractRecent work in our laboratory has allowed the development of quantitative31P NMR spin trapping techniques. These methods have been demonstrated to be effective tools for the detection and absolute quantification of many oxygen‐ and carbon‐centered free radical species. Our methods rest on the fact that a free radical reacts with the nitroxide phosphorus compound, 5‐diisopropoxy‐phosphoryl‐5‐methyl‐1‐pyrroline‐N‐oxide (DIPPMPO), to form stable radical adducts, which are suitably detected and accurately quantified using31P NMR in the presence of phosphorus containing internal standards. This system was applied for the detection of phenoxy radicals, as an alternative to traditional EPR techniques. More specifically, the phenoxy radicals were produced via the oxidation of different phenols by K3Fe(CN)6. The31P NMR signals for the radical adducts of phenoxy radicals (PhO·) were assigned and found to be located at 25.2 ppm. Subsequently, this spin trapping system was applied to the oxidation of various phenols in the presence of peroxidases and 1‐hydroxybenzotriazole (HBT) as a mediator: the 2,4,6‐trichlorophenol and 2,4,6‐tri‐tert‐butylphenol were oxidized and only phenoxy radical adducts were detected, whereas during the oxidation of 2,4‐dimethylphenol and isoeugenol, other adducts were detected and related to radical delocalization. These preliminary efforts demonstrate the efficacy of our methodologies, so that a variety of radical species can now be readily detected and quantified using quantitative31P NMR spin trapping techniques. Copyright © 2009 John Wiley & Sons, Ltd.
Modeling of Capacitively Coupled RF Plasmas in H2
Authors: Longo Savino , Diomede Paola 
Published: May 2009

AbstractHydrogen is the main component of many feeding mixtures used for plasma processing. Despite this, the physics and chemistries of the parallel plate, capacitively coupled, radio frequency discharges in pure hydrogen are not yet fully understood. The state of the art of the modeling of this system is analyzed, including the problems posed by the electron and ion reactions, the ion heating, the chemistry of excited molecules, the non‐equilibrium distributions, the surface catalytic reactions, the double frequency discharge effects. Specific points are illustrated using new results obtained by a self‐consistent kinetic model developed in the last 10 years. A concluding discussion summarizes the achievements and open problems of the field.magnified image