bluuebunny/crossref_metadata_2025_split huggingface dataset:
Darstellung chiraler heterocyclischer β-Aminosäureester / Preparation of Chiral Heterocyclic Esters of β-Amino Acids
Authors: Aurich Hans Günter , Gentes Christian , Sievers Ulrich 
Published: February 2015

Chiral β-amino alcohols were successively prone to N-benzylation, O-allylation and oxidation of the resulting benzylamino group to give nitrones 3 which on hydrolysis afforded chiral hydroxylamines HO-NH-CH(R)-CH2-O-CH2-CH=CH2 ((S)-4: R = Me, Bn, iPr. (R)-4: R = Et). Swern oxidation of methyl 2,2-dimethyl-3-hydroxypropionate (16) and treatment of the resulting aldehyde 17 with hydroxylamines (S)-4b (R = Bn) or (R)-4d (R = Et) provided nitrones 18 that underwent an intramolecular 1,3-dipolar cycloaddition on heating yielding the bicyclic β-amino-acid esters 19b and ent-19d, respectively.Reductive cleavage of the N,0- bond of compounds 19 afforded the eight-membered ring compounds 20b and ent-20d, respectively.
N-Benzylalaninol (22) was treated with /3-bromo-methacrylate to give the amino alcohol 23. Swern oxidation and subsequent treatment with N-ferf-butylhydroxylamine provided the bicyclic ester 26a (R = t-Bu) via the corresponding nitrone 24. Oxime 25 was prepared in an analogous way as 24 with unsubstituted hydroxylamine. It underwent an intramolecular 1.3- dipolar cycloaddition yielding 26b on heating in toluene. Reduction of 26a afforded the pyrrolidine-carboxylic ester 27a.
Some Organic-Inorganic Hybrid Compounds Based on iso– Thiuronium Cations and Lead Halide Anions
Authors: Papavassiliou G. C. , Mousdis G. A. , Koutselas I. B. 
Published: February 2015

Abstract
Using 1-chlorodecane (C10H21CI), benzyl chloride (C6H5CH2CI), a,a'-dichloro-p-xylene (CICH2C6H4CH2CI), 4-phenylbenzyl chloride (C6H5C6H4CH2CI), 2-bromomethyl-naphthal-ene (C10H7CH2Br), 4-bromomethyl-7-methoxycoumarin (C10H7O3CH2Br), 2-bromomethyl-anthraquinone (C14H7CH2Br), 9-chloromethyl-anthracene (C14H9CH2CI), thiourea and halides as starting materials, the organic-inorganic hybrid compounds [C10H21SC(NH2)2]2Pbl4, [C6H5CH2SC(NH2)2]4Pb3l10 [(H2N2)CSCH2C6H4CH2SC(NH2)2]0.5PbI3, [C6H5C6H4CH2S-C(NH2)2]PbI3, [C10H7CH2SC(NH2)2]Pbl3, [C14H7 O2CH2SC(NH2)2]Pbl3, [C14H9CH2SC(NH2)2]PbI3, and [C14H9CH2SC(NH2)2]PbBr4, were prepared and characterized analytically and spectroscopically.
Über Komplexe des Typs {(PhC=C)3P}3M(CO)3 (M = Cr, Mo, W) / On Complexes of the Type {(PhC=C)3P}3M(CO)3 (M = Cr, Mo, W)
Authors: Kuhn Norbert , Göhner Martin , Steimann Manfred 
Published: February 2015

Abstract
The tris(alkinyl)phosphine complexes {(PhC=C)3P}3M(CO)3, M = Cr (3a), Mo (3b), W (3c), are obtained from P(C=CPh)3 and (C6H15N3)M(CO)3 (C6H15N3 = 1,3,5-trimethyl-1,3,5-triazacyclohexane) as stable yellow solids in good yields. While IR data indicate significant acceptor properties of the phosphane ligands, the X-ray structure analysis of 3c also allows the discussion of weak donor interactions.
Preparation and Characterization of 4-[4-(Dimethylamino)styryl]-l-methyl- pyridinium Lead Triiodide and its Tribromide Analog
Authors: Papavassiliou G. C. , Mousdis G. A. , Koutselas I. B. 
Published: February 2015

Abstract
Using 4-[4-(dimethylamino)styryl]-l-methyl-pyridinium iodide, lead iodide, tetrabutylammon-ium bromide and lead bromide as starting materi­ als, the title compounds were prepared and characterized analytically and spectroscopically.
The Crystal and Molecular Structure of (μ-Oxo)bis{chloro(methyl)thienyl- tellurium(IV)}
Authors: Oilunkaniemi Raija , Laitinen Risto S. , Ahlgrén Markku 
Published: February 2015

Abstract
The formation and the crystal and molecular structure of (μ-oxo)bis{chloro(methyl)thienyl-tellurium(IV)}, [Me(Th)TeCl]20 , are described. The compound is orthorhombic, space group Pbcn, a = 1893.30(2), b = 891.96(2), c = 966.24(5) pm; Z =4. The tellurium atom shows trigonal bi-pyramidal coordination with chlorine and the bridging oxygen atoms in axial, and methyl and thienyl groups in equatorial positions. The two close intermolecular Te(1) ···Cl(1) contacts ex­pand the coordination sphere around tellurium to an almost regular octahedron.
[((C6H5)3P)2N ]O3 und [(((CH3 )2 N)3 PN)4 P]O3 , neue ionische Ozonide mit Phasentransfer-geeigneten Kationen
Authors: Klein Wilhelm , Jansen Martin 
Published: February 2015

Abstract
Ionic ozonides soluble in organic solvents have been synthesized. The crystal structures of bis(triphenylphosphine)iminium-ozonide bis(dimethylamine) (1/2) (P21/c, a = 969.9(2) pm, b = 2007.1(3) pm, c = 1852.4(4) pm, Z = 4, R1 = 14.34%, 3343 independent reflections), tetrakis[tris(dimethylamino)phosphoranylidenamino]phosphonium-ozonide (P21/n, a = 1120(1) pm, b = 3192(5) pm, c = 1162(1) pm, Z = 4, R1 = 9.18%, 1428 independent reflections) and tetrakis[tris(dimethylamino)phosphoranylidenamino]phosphonium-ozonide dimethylamine (1/1) (Pbcn, a = 1080.9(6) pm, b = 3560(5) pm, c = 1154(2) pm, Z = 4, R1 = 12.22%, 2624 independent reflections) have been solved. While these ozonides react with ethers and nitriles, stable solutions in amines and CH2Cl2 have been obtained.
New π -Donor Molecules with a Pyrazino Group and their Conducting Salts
Authors: Papavassiliou G. C. , Misaki Yohji , Takahashi Kazuko , Yamada Jun-ichi , Mousdis G. A. , Sharahata Takashi , Ise Toshihiro 
Published: February 2015

Abstract
The preparation and characterization of some π-donors with a pyrazine-edge-group as well as with tetrathiapentalene-, thiophene-, and dihydrobenzoselenophene-spacer-groups are de­ scribed. Some of these donors give conducting charge transfer complexes with TCNQ and/or cation radical salts with I3
-, BF4
-and PF6
-as counter anions.
Synthesis, Characterization, Crystal Structure and hybrid DFT Computation of the Chlorooxoarsenate(III), [NMe4]2[As4O2Cl10]·2 CH3CN
Authors: Klapötke Thomas M. , Schütt Thomas 
Published: February 2015

Abstract
[NMe4]2 [As4O2Cl10] · 2 CH3CN was recovered by the reaction of [NMe4][N3] with AsCl3 in CH3CN under aerobic conditions. This compound was also obtained directly by the reaction of AsCl3, AS2O3 and [NMe4][Cl] in acetonitrile. The structure was determined by X-ray diffraction. [NMe4]2 [As4O2Cl10] · 2 CH3CN crystallizes in theoorthorhombic space group Fmmm with a = 11.4144(8), b = 14.732(1) and c = 19.803(2) Å, with 4 formula units per unit cell. The frequencies obtained by Raman and infrared spectroscopy were assigned to the normal modes of the [As4O2Cl10]2- anion in comparison with computational results. The bonding situation in the [As4O2Cl10]2- anion was elucidated on the basis of an NBO analysis on the crystallographic data.
Synthese und Eigenschaften von α Aminocarbohydroximsäure-estern / Synthesis and Properties of α-Aminocarbohydroximic Esters
Authors: Thimann Wolfgang , Geffken Detlef 
Published: February 2015

Abstract
Cbz protected α-aminonitriles 1 or α-aminocarboxamides 2 were converted to imidates 3 either by Pinner reaction or by Meerwein’s reagent. Sulfhydrolysis of 3 produced α-aminothiocarboxylic O-esters 4 which in turn were reacted with hydroxylamine to give Cbz protected (E)-α-aminocarbohydroximic esters 5. Hydrogenolysis of 5 furnished the target compounds 6 .
A New Synthesis of Two Naturally Occurring Dihydrobenzo[b]furan-Type Neolignans of Potential Biological Activity
Authors: Juhász László , Dinya Zoltán , Antus Sándor , Gunda Tamás E. 
Published: February 2015

Abstract
A new synthesis of the racemates of two naturally occurring neolignans 1 and 2 was achieved via the 2,3-dihydrobenzo[b]furan derivative 3, starting from the commercially available materials o-vanillin (6) and acetovanillone (9).
Radikal-markierte Metallocene (M = Fe, Co). Metallocenylen verbrückte Bis(3-imidazolin-l-oxyle) / Radical Labeled M etallocenes (M = Fe, Co). M etallocenylene B ridged B is(3-im idazolin-l-oxyls)
Authors: Dialer Harald , Polbom Kurt , Beck Wolfgang 
Published: February 2015

Abstract
Radical Labeled M etallocenes (M = Fe, Co). M etallocenylene B ridged B is(3-im idazolin-l-oxyls) The addition of the lithium salt of the silyl protected hydroxylamine 1-hydroxy-2,2,4,5,5-pentamethyl-3-imidazoline (1) to 6 ,6 -dimethylfulvalene gives the lithium cyclopentadienide 2 from which the 1,1 '-substituted ferrocene and cobaltocinium derivatives 3 and 4 were obtained. Deprotection and oxidation of 3 and 4 afford the metallocenylene bridged bis(3-imidazolin-l-oxyls) 5 and 7. The ferrocene bridged diradical 5 forms with DDQ a charge transfer complex 8 . The complexes 5 and 7 were characterized by X-ray diffraction and by their EPR spectra. Magnetic measurements show at room temperature two independent spins for 5 and 7 and four unpaired electrons for 8 , the latter arising from three different sources [Fe(III) low spin d5, two nitroxides and DDQ- radical anion].
Methylated Ammonium and Hydrazinium Salts of 5,5′-Azotetrazolate
Authors: Hammerl Anton , Holl G. , Kaiser M. , Klapötke Thomas M. , Mayer Peter , Piotrowski Holger , Vogt Martin 
Published: February 2015

Abstract
Salts of the 5,5′-azotetrazolate dianion with methylated ammonium and hydrazinium cations were prepared. The compounds were characterized by elemental analysis, vibrational (IR, Raman) and multinuclear NMR spectroscopy (1H, 13C, 14N). The crystal structures of the di[ammonium], the bis[dimethylammonium] and the bis[trimethylhydrazinium] 5,5′-azo­ tetrazolate salts were determined. The thermal, shock and friction sensitivities of these com­ pounds were investigated and their explosion products were analysed.
Magnetic Properties and Crystal Structure of a Dinuclear Iron(III) Complex
Authors: Elmali A. , Elerman Y. , Svoboda I. 
Published: February 2015

Abstract
[FeL(MeOH)Cl]2 (L = N-(5-methylphenyl)-3-methoxysalicylaldimine) was synthesized and its crystal structure determined, [C30H26Cl2Fe2N2O6], triclinic, space group P1̄, a = 7.481(2), b = 9.436(2), c = 10.961(2) Å, α= 69.790(10), β= 82.440(10), γ= 83.690(10)°, V=718.1(3) Å3 , Z = 1. Two identical [FeLCl] fragments, related by an inversion centre, are connected by two bridging O atoms to form a binuclear unit. The iron(III) centers are separated by 3.196(2) Å and weakly antiferromagnetically coupled (J = -10.4(1) cm-1), which follows from temperature-dependent magnetic susceptibility measurements in the range 5.1 to 275.6 K. The magnetic moment at 275.6 K is ca. 7.02 B. M., but 0.99 B. M. at 5.1 K. The magnetic susceptibility is at a maximum near 80 K and decreases rapidly as the temperature is lowered to liquid helium temperature.
Neue Oxogermanate(IV) der schweren Alkalimetalle. Synthesen und Kristallstrukturen/New Oxogermanates(IV) of the Heavy Alkaline Metals. Preparation and Crystal Structure
Authors: Hoch Constantin , Röhr Caroline 
Published: February 2015

Abstract
The new germanates(IV) were synthesized via reaction of GeO2 with AO2 (A=K, Rb, Cs) and the elemental alkaline metals and their crystal structures have been determined from single crystal X-ray data. ß-K4GeO4 / Rb4GeO4 (monoclinic, P21/c , a = 1047.6(3)/1103.2(2), b = 646.5(1)/673.3(1), c = 1048.1(3)/1084.5(2) pm, ß = 112.291(5) / 112.676(4)°, Z = 4) and Cs10Ge2O9 (monoclinic, P21/c , a = 1293.7(2), b = 1148.6(2), c = 1926.4(2) pm, ß = 128.05(8)°, Z = 4) contain isolated, A6Ge3O9 (A = Rb / Cs: monoclinic, P 21/c , a = 663.0(1) / 696.3(2), b = 1346.8(2) / 1403.1(3), c = 1666.6(2) / 1742.8(6) pm, ß = 107.47(2) / 107.88(2)°, Z = 2) cyclotrigermanate ions. In Cs3AlGe2O7 (monoclinic, C2/c, a = 961.5(2), b = 1719.7(2), c = 761.7(1) pm, ß =126.5(1)°, Z = 4) digermanate ions are connected via [AIO4 ] tetrahedra to form ribbons.
Formation and Crystal Structure of Polymeric (MeTeCl3)n
Authors: Pietikäinen Jarkko , Laitinen Risto S. , Konu Jari , Valkonen Jussi 
Published: February 2015

Abstract
The reaction of hexamethyldisilane with tellu­rium tetrachloride in carbon disulfide afforded polymeric (MeTeCl3)n (1) that was characterized by TOF ES mass spectroscopy, 125Te NMR spectroscopy, and X-ray crystallography. Pale brown, air-and moisture-sensitive crystals of 1 are monoclinic, space group P21/n with a = 1030.69(5), b = 643.61(2), c = 1041.68(5) pm, ß = 119.236(5)°, V = 0.60299(5) nm3, and Z = 4. The crystal structure consists of infinite helical chains of the MeTeCl3 units linked by bridging chlorine atoms. The polymeric chains are linked together by Te···Cl and Cl···Cl close contacts. The pos­sible routes for the formation of (MeTeCl3)n are discussed.
BMI Curves for Preterm Infants
Authors: Olsen Irene E. , Lawson M. Louise , Ferguson A. Nicole , Cantrell Rebecca , Grabich Shannon C. , Zemel Babette S. , Clark Reese H. 
Published: February 2015

BACKGROUND AND OBJECTIVES:Preterm infants experience disproportionate growth failure postnatally and may be large weight for length despite being small weight for age by hospital discharge. The objective of this study was to create and validate intrauterine weight-for-length growth curves using the contemporary, large, racially diverse US birth parameters sample used to create the Olsen weight-, length-, and head-circumference-for-age curves.METHODS:Data from 391 681 US infants (Pediatrix Medical Group) born at 22 to 42 weeks’ gestational age (born in 1998–2006) included birth weight, length, and head circumference, estimated gestational age, and gender. Separate subsamples were used to create and validate curves. Established methods were used to determine the weight-for-length ratio that was most highly correlated with weight and uncorrelated with length. Final smoothed percentile curves (3rd to 97th) were created by the Lambda Mu Sigma (LMS) method. The validation sample was used to confirm results.RESULTS:The final sample included 254 454 singleton infants (57.2% male) who survived to discharge. BMI was the best overall weight-for-length ratio for both genders and a majority of gestational ages. Gender-specific BMI-for-age curves were created (n = 127 446) and successfully validated (n = 126 988). Mean z scores for the validation sample were ∼0 (∼1 SD).CONCLUSIONS:BMI was different across gender and gestational age. We provide a set of validated reference curves (gender-specific) to track changes in BMI for prematurely born infants cared for in the NICU for use with weight-, length-, and head-circumference-for-age intrauterine growth curves.
The European Spallation Source And Future Opportunities For Materials Science
Authors: Kirstein Oliver 
Published: February 2015

ABSTRACTThe European Spallation Source is Europe’s next generation high-power neutron source utilising a linear accelerator and a rotating tungsten target to produce neutrons that will be used for fundamental research and industrial applications. The facility is co-hosted by the states of Denmark and Sweden, and while the main site will be placed in Lund, Sweden, the Data Management and Software Centre will be located in Copenhagen, Denmark. The facility will cover a broad range of scientific applications in the fields of physics, chemistry, biology, or life sciences. A focus will also be materials science and engineering, and dedicated instruments will gradually become available to the user community once neutrons will be produced neutrons from 2019 onwards.
Simulating the Dynamic Effect of Land Use and Transport Policies on the Health of Populations
Authors: McClure Roderick J. , Adriazola-Steil Claudia , Mulvihill Christine , Fitzharris Michael , Salmon Paul , Bonnington C. Paul , Stevenson Mark 
Published: February 2015

Objectives. We identified the features of a land use–transportation system that optimizes the health and well-being of the population. Methods. We developed a quantitative system dynamics model to represent relationships among land use, transport, economic development, and population health. Simulation experiments were conducted over a 10-year simulation period to compare the effect of different baseline conditions and land use–transport policies on the number of motor vehicle crash deaths and disability-adjusted life years lost. Results. Optimal reduction in the public health burden attributable to land transport was demonstrated when transport safety risk reduction policies were combined with land use and transport polices that minimized reliance on individual motorized transport and maximized use of active transport modes. The model’s results were particularly sensitive to the level of development that characterized each city at the start of the simulation period. Conclusions. Local, national, and international decision-makers are encouraged to address transport, land use, and health as an integrated whole to achieve the desired societal benefits of traffic safety, population health, and social equity.
Economic Shocks and Public Health Protections in US Metropolitan Areas
Authors: Mays Glen P. , Hogg Rachel A. 
Published: February 2015

Objectives. We examined public health system responses to economic shocks using longitudinal observations of public health activities implemented in US metropolitan areas from 1998 to 2012. Methods. The National Longitudinal Survey of Public Health Systems collected data on the implementation of 20 core public health activities in a nationally representative cohort of 280 metropolitan areas in 1998, 2006, and 2012. We used generalized estimating equations to estimate how local economic shocks relate to the scope of activities implemented in communities, the mix of organizations performing them, and perceptions of the effectiveness of activities. Results. Public health activities fell by nearly 5% in the average community between 2006 and 2012, with the bottom quintile of communities losing nearly 25% of their activities. Local public health delivery fell most sharply among communities experiencing the largest increases in unemployment and the largest reductions in governmental public health spending. Conclusions. Federal resources and private sector contributions failed to avert reductions in local public health protections during the recession. New financing mechanisms may be necessary to ensure equitable public health protections during economic downturns.
Profile of the Public Health Workforce: Registered TRAIN Learners in the United States
Authors: Jones Jeffery A. , Banks Lois , Plotkin Ilya , Chanthavongsa Sunny , Walker Nathan 
Published: February 2015

Objectives: We analyzed data from the TrainingFinder Real-time Affiliate Integrated Network (TRAIN), the most widely used public health workforce training system in the United States, to describe the public health workforce and characteristics of individual public health workers. Methods: We extracted self-reported demographic data of 405 095 learners registered in the TRAIN online system in 2012. Results: Mirroring the results of other public health workforce studies, TRAIN learners are disproportionately women, college educated, and White compared with the populations they serve. TRAIN learners live in every state and half of all zip codes, with a concentration in states whose public health departments are TRAIN affiliates. TRAIN learners’ median age is 46 years, and one third of TRAIN learners will reach retirement age in the next 10 years. Conclusions: TRAIN data provide a limited but useful profile of public health workers and highlight the utility and limitations of using TRAIN for future research.
Étranges rencontres : Julius Zeyer et Marguerite Yourcenar [Strange Coincidences : Julius Zeyer and Marguerite Yourcenar]
Authors: Voisine-Jechová Hana 
Published: February 2015

Záhadná setkání Marguerite Yourcenarová a Julius Zeyer

Zeyerova próza Večer u Idalie vyšla v roce 1892, povídka Marguerite Yourcenarové Jak se Wang-Fô zachránil byla poprvé publikována v roce 1936. Přímý vztah mezi českým básníkem a francouzskou spisovatelkou nelze předpokládat a bylo by obtížné stanovit i jejich společný pramen. Ocítáme se před paralelami, které se v literatuře objevují častěji a které vždy nutí k zamyšlení. U Zeyera dílo malíře, který se dostává do konfliktu se světskou mocí, nádherná krajina zastírající holou zeď, zmizí. Umělec odchází do obrazu a s ním tam odchází i císařova dcera, která věřila v sílu umění. Ve francouzské povídce je starý malíř odsouzen k trestu smrti, neboť jeho dílo lhalo krásu, která ve skutečnosti neexistuje. Malíř však dokončí obraz představující moře a loďku, voda zaplaví sál, malíř nasedne do loďky, kde ho už čeká jeho věrný učedník, který, dříve popravený, obživne, a oba odplují do světa vytvořeného uměním. Voda ze sálu ustoupí a císař i jeho komonstvo se octnou znova v banální realitě. Jestliže však umění zachraňuje člověka, skrývá se v něm i nebezpečí. Učedník malíře Wang-Fô začal dávat přednost obrazu své ženy před ní samou – a ta ze zoufalství spáchala sebevraždu. A hrdina jiné Zeyerovy prózy dokonce prohlašuje, že
umění má něco společného se zločinem.
Emploi de la conjonction de coordination i « et » lors de la formation des déterminants numéraux composés en bosniaque, croate, monténégrin, serbe (BCMS) [The Use of the Conjunction i ‘and’ in the Formation of Compound Numerals Functioning as Determiners in Bosnian, Montenegrin, Croatian and Serbian (BCMS)]
Authors: Stefanovic Aleksandar 
Published: February 2015

The Use of the Conjunction i ‘ and’ in the Formation of Compound Numerals Functioning as Determiners in Bosnian, Montenegrin, Croatian and Serbian (BCMS)
The paper deals with the evolution of the use of the conjunction i ‘ and’ in the expression of compound numerals functioning as determiners (cardinal and collective numerals ; nominal numerals in -ica, derived from collective numerals and adjectival numerals). The author gives the historical and dialectological overview without which the state of the current written and oral languages cannot be judged. He also pays particular attention to the (few) views concerning that issue contained in language textbooks. One of the conclusions of the paper is that those views generally do not coincide with usage in modern languages.
Use of Neuraminidase Inhibitors in Primary Health Care during Pandemic and Seasonal Influenza between 2009 and 2013
Authors: Blanchon Thierry , Geffrier Félicité , Turbelin Clément , Daviaud Isabelle , Laouénan Cédric , Duval Xavier , Lambert Bruno , Hanslik Thomas , Mosnier Anne , Leport Catherine 
Published: February 2015

Background In a context of controversy about influenza antiviral treatments, this study assessed primary healthcare physicians’ prescription of neuraminidase inhibitors (NIs) in France during pandemic and seasonal influenza between 2009 and 2013. Methods This observational study, using data recorded in three national databases, estimated the rate of NI prescription among influenza-like illness (ILI) patients seen in GP and paediatrician consultations, and determined factors associated with this prescription according to a multivariate analysis. NI delivery by pharmacists was also evaluated. Results Rates of NI prescription were estimated to be 61.1% among ILI patients with a severe influenza risk factor seen in GP consultation during the A(H1N1)pdm2009 pandemic versus an average rate of 25.9% during the three following seasonal influenza epidemics. Factors associated with NI prescription were a chronic disease in patients under 65 years (OR 14.85; 95% CI 13.00, 16.97) and in those aged 65 and older (OR 7.54; 5.86, 9.70), an age ≥65 years in patients without chronic disease (OR 1.35; 1.04, 1.74), a pregnancy (OR 10.63; 7.67, 15.76), obesity (OR 4.67; 3.50, 6.22) and a consultation during the pandemic A(H1N1)pdm2009 (OR 3.19; 2.93, 3.48). The number of antiviral treatments delivered by pharmacists during the A(H1N1)pdm2009 pandemic was 835 per 100,000 inhabitants, and an average of 275 per 100,000 inhabitants during the three following seasonal influenza epidemics. Conclusions Although physicians seem to follow the recommended indications for NIs in primary health-care practice, this study confirms the low rate of NI prescription to ILI patients with a severe influenza risk factor, especially during seasonal epidemics.