bluuebunny/crossref_metadata_2025_split huggingface dataset:
Strukturuntersuchungen an Diaryldichalkogeniden: Die Molekülstrukturen von [2,4,6-(CF3)3C6H2S]2,[2,4,6-Me3C6H2Te]2 und [2-Me2N-4,6-(CF3)2C6H2Te]2 / Structural Investigations of Diaryl Dichalcogenides: The Molecular Structures of [2,4,6-(CF3)3C6H2S]2, [2,4,6-Me3C6H2Te]2 and [2-Me2N-4,6-(CF3)2C6H2Te]2
Authors: Edelmann Anja , Brooker Sally , Bertel Norbert , Noltemeyer Mathias , Roesky Herbert W. , Sheldrick George M. , Edelmann Frank T. 
Published: March 2015

Abstract
The Molecular Structures of [2,4,6-(CF3)3C6H2S]2 (1) [2,4,6-Me3C6H2Te]2 and [2-Me2N-4,6-(CF3)2C6H2Te]2 (3) have been determined by X-ray diffraction. Crystal data: 1: orthorhombic, space group P212121, Z = 4, a = 822.3(2), b = 1029.2(2), c = 2526.6(5) pm (2343 observed independent reflexions, R = 0.042); 2: orthorhombic, space group Iba 2, Z = 8, a = 1546.5(2), b = 1578.4(2), c = 1483.9(1) pm (2051 observed independent reflexions, R = 0.030); 3: monoclinic, space group P 21/c, Z = 4, a = 1118.7(1), b = 1536.5(2), c = 1492.6(2) pm, β = 98.97(1)° (3033 observed independent reflexions, R = 0.025).
Darstellung von Difluormethanimin F2C = NH und F2C = ND durch Hydrolyse von CF3NCO / Preparation of Difluoromethanimine F2C = NH and F2C = ND by Hydrolyses of CF3NCO
Authors: Pawelke Gottfried , Dammei Ralph , Poll Wolfgang 
Published: March 2015

Abstract
The title compounds have been prepared by controlled hydrolysis of CF3NCO in NEt3. Their 13C, 19F and 1H NMR spectra are reported and their I R gas and I R matrix spectra are discussed in terms of a normal coordinate analysis. The photoelectron spectrum of F2C = NH is compared with those of F2C = NF and H2C = NH revealing a strong fluoro effect. In the solid state F2C = NH is aggregated to infinite zig-zag chains by N • • • H hydrogen bonding.
Über die Wechselwirkung des Vanadyl(IV)-Kations mit Calcium-Hydroxylapatit / The Interaction of the Vanadyl(IV) Cation with Calcium Hydroxylapatite
Authors: Narda G.E. , Vega E. D. , Pedregosa J. C. , Etcheverry S. B. , Baran E. J. 
Published: March 2015

Abstract
Solid products obtained from calcium hydroxylapatite suspensions in diluted VO2+ solutions, under different experimental conditions, were investigated by means of X-ray powder diffractometry and IR and ESR spectroscopy. It is demonstrated that the VO2+ cation cannot be incorporated into the apatite-lattice but is strongly adsorbed on the surface of the material. Different aspects of this adsorption were thoroughly investigated. The ESR spectra suggest an inhomogeneous distribution of the adsorbed species and the generation of O = V (O)4 moieties, which show a high stability towards oxidation.
Polysulfonylamine, XXXI. Kristallstruktur von (1-Trichlormethylthio- 4-dimethylaminopyridinium)dimesylamid bei -95 °C / Polysulfonylamines, XXXI. Crystal Structure of 1-Trichloromethylthio- 4-dimethylaminopyridinium Dimesylamide at -95 °C
Authors: Jones Peter G. , Näveke Martina , Blaschette Armand 
Published: March 2015

Abstract
The crystal structure of the title compound was determined at -9 5 °C. It crystallizes in space group P1̄ with a = 577.5(3), b = 820.2(3), c = 1916.6(8) pm, α = 83.34(2), β = 82.83(2), γ = 83.61(2)° and Z = 2. The final R value was 0.034 for 3019 unique observed reflections. The presence of aggregates of four ions (two cations and two an­ ions) in the solid state is observed, with short cat-ion-anion contacts SII ⋯ O (290 pm) and Cl ⋯ O (298 pm). The bond lengths of the 4-dimethylaminopyridinium moiety of the cation suggest a semiquinoid resonance form with a double bond to the nitrogen of the dimethylamino group and two localized double bonds in the ring. The ring, the dimethylamino group (except H atoms) and the Sn atom are coplanar. The SII -N bond length is 170.3 pm, the N -SII -C angle 99.6°. The SII -C bond is approximately perpendicular to the ring plane.
The Final Structures of the Lichen Chromones Galapagin, Lobodirin, Mollin, and Roccellin
Authors: Huneck Siegfried , Jakupovic Jasmin , Follmann Gerhard 
Published: March 2015

Abstract
The structures of the lichen chromones galapagin, lobodirin, mollin, and roccellin, specific com­ pounds of Roccellaceae (lichens), have been es­ tablished as 1, 2, 3, and 4, respectively, by NOE difference spectroscopoy.
Synthese und Kristallstruktur von Bis(m-aminobenzonitril)- diquecksilber(I)-dinitrat/Synthesis and Crystal Structure of Bis(m-aminobenzonitrile)dimercury(I)-dinitrate
Authors: Brodersen Klaus , Hofmann Jürgen 
Published: March 2015

The structure of bis(m-aminobenzonitrile)dimercury(I) dinitrate, [Hg2(m -NH2C6H4CN)2](NO3)2 has been determined by single crystal X-ray diffraction techniques and refined to an Rw-value of 0.022. The crystals are triclinic, space group P1 with a = 5.4878(1) Å, b = 8.4085(1) Å, c = 9.6062(1) Å, α = 92.599(3)°, β = 94.763(3)°, γ = 89.614(3)° and Z = 1.
The Hg2
2+-ion [Hg-Hg 2.524(1) Å] is approximately axially coordinated to amino nitrogen atoms [Hg - N 2.209(4) Å, Hg - Hg - N 169.5(3)°]. Additional amino hydrogen bonds to oxygen are building chains along the b-axis containing units of L - Hg - Hg - L groups.
Kohlenwasserstoffverbrückte Metallkomplexe, XXIV. Pentacarbonylrhenio-substituierte Thiophen-, Cyclohexadienyl-und Benzol-Komplexe von Mangan, Rhenium und Eisen/Hydrocarbon Bridged Complexes, XXIV. Pentacarbonylrhenio Substituted Thiophene, Cyclohexadienyl and Benzene Complexes of Manganese, Rhenium and Iron
Authors: Niemer Burkhard , Weidmann Torsten , Beck Wolfgang 
Published: March 2015

Abstract
The addition of pentacarbonylrhenate to [(OC)3Mn(thiophene)]+, [(OC)3M(η6-C6H4R2)]+ (M = Mn, Re; R = H, Me, Cl) yields the σ,π-hydrocarbon bridged complexes (OC)3Mn(μ-η4:η1-C4H4S)Re(CO)5 and (OC)3M(μ-η6:η1-C6H4R2)Re(CO)5, respectively. The latter complexes have also been obtained from (OC)5MFBF3 (M = Mn, Re) and C6H5Re(CO)5. The fluxional behaviour of the cyclohexadienyl bridged complexes is probably due to a 1,2-shift of the Re(CO)5 group. The reaction of [Re(CO)5]-with [(η5-C5H5)Fe(η6-p-C6H4(R)Cl)]+ (R = H, Me, Cl) proceeds with substitution of chlorine to give the heterobimetallic compounds [(η5-C5H5)Fe[μ-η6:η1-C6H4(R)]Re(CO)5]+.
Synthesis and Ligand Exchange Reaction of Some Organotin(IV) Bis(N-arylsulphonyl-N-arylhydroxylaminates)
Authors: Das Mrinal K. , Nath Matilal , De Somnath 
Published: March 2015

Abstract
Several diorganotin(IV)-bis(N-arylsulphonyl-N-arylhydroxylaminates) of the general formula R2Sn[ON(R1)SO2R2]2 have been synthesized and characterized by elemental analyses and by IR and 1H NMR spectra. A representative ligand exchange reaction with N-benzoyl- N-phenylhydroxylamine has been carried out.
Metallkomplexe von Farbstoffen, IV [1]. Übergangsmetallverbindungen mit den Dianionen von Epindolidion und 2.8-Dimethylepindolidion als Bis(chelat)-Liganden / Metal Complexes of Dyes, IV [1]. Transition Metal Compounds of the Dianions of Epindolidione and 2.8-Dimethylepindolidione as Bis(chelate) Ligands
Authors: Schmidt Christoph , Beck Wolfgang , Schmidt Christoph , Beck Wolfgang 
Published: March 2015

Abstract
The dianions of epindolidione and dimethylepindolidione act as bis(chelate) ligands (L) and form deep red polymeric complexes [L′ML]n (M = Ni(II), Co(II); L′ = DMF, PEt3). They react with chloro bridged complexes [(R3P)MCl2]2 (M = Pd, Pt) and [(η5-C5Me5)MCl2]2 (M = Rh, Ir) to give red bis-N,O-chelate complexes (R3P)(Cl)M-μ-L-M (Cl)(PR3) and (η5-C5H5)(Cl)M -μ-L-M(Cl)(η5-C5H5).
Synthese und Einkristall-Strukturanalyse des Oxidnitrits K5AgO2(NO2)2 / Synthesis and Single Crystal Structure Analysis of the Oxide Nitrite K5AgO2(NO2)2
Authors: Bremm Thomas , Jansen Martin 
Published: March 2015

Abstract
The title compound has been characterized by X-ray powder and single crystal diffraction: Pbam. a = 715.8(1), b = 1393.1(2), c = 539.4(1) pm; Z = 2; 1088 diffractometer data; R = 0.087, Rw = 0.083. The crystal structure is a variant of the anti-perovskite type of structure. The NO2
- anion is rotationally disordered.
Über die Reaktion von protonierter Stickstoffwasserstoffsäure mit Schwefeldichiorid und die Kristallstruktur von N(SCl)2
+SbCl6
- / On the Reaction of Protonated Hydrazoic Acid with Sulfurdichloride and the Crystal Structure of N(SCl)2
+SbCl6
-
Authors: Minkwitz Rolf , Budde Uwe , Bäck Birgit , Preut Hans 
Published: March 2015

Abstract
H2N3
+SbCl6
- reacts in SO2 as a solvent with SCl2 to give N(SCl)2
+SbCl6
-. The yellow salt crys­tallizes in the monoclinic space group P21/c with a = 729.7(7), b = 1122.1(8), c = 1575.6(11) pm, and β = 99.43(6)° at 169 K with 4 formula units per unit cell. The vibrational spectra are reported.
Habitual coffee intake, genetic polymorphisms, and type 2 diabetes
Authors: Lee Jae Kyung , Kim Kyunga , Ahn Younjhin , Yang Mihi , Lee Jung Eun 
Published: March 2015

BackgroundThe association between coffee intake and type 2 diabetes may be modulated by common genetic variation.ObjectiveThe purpose of this study was to examine the association between habitual coffee intake and the risk of type 2 diabetes and to determine whether this association varied by genetic polymorphisms related to type 2 diabetes in Korean adults.Design and methodsA population-based cohort study over a follow-up of 4 years was conducted. A total of 4077 Korean men and women aged 40–69 years with a normal glucose level at baseline were included. Coffee intake was assessed using a validated food frequency questionnaire, and incident type 2 diabetes or prediabetes was defined by oral glucose tolerance test or fasting blood glucose test. The genomic DNA samples were genotyped with the Affymetrix Genome-Wide Human SNP Array 5.0, and nine single-nucleotide polymorphisms related to type 2 diabetes in East Asian populations were extracted.ResultsA total of 120 cases of type 2 diabetes and 1128 cases of prediabetes were identified. After adjustment for potential confounding factors, we observed an inverse association, but without any clear linear trend, between coffee intake and the combined risk of type 2 diabetes and prediabetes. We found that inverse associations between habitual coffee intake and the combined risk of type 2 diabetes and prediabetes were limited to those with the T-allele (GT/TT) of rs4402960 inIGF2BP2, those with the G-allele (GG/GC) of rs7754840 inCDKAL1, or those with CC of rs5215 inKCNJ11.ConclusionWe found a lower risk of prediabetes and type 2 diabetes combined with coffee intake among individuals with the GT/TT ofIGF2BP2rs4402960, GG/GC ofCDKAL1rs7754840, or CC ofKCNJ11rs5215, which are known to be related to type 2 diabetes in East Asians.
Etiology of Childhood Bacteremia and Timely Antibiotics Administration in the Emergency Department
Authors: Irwin Adam D. , Drew Richard J. , Marshall Philippa , Nguyen Kha , Hoyle Emily , Macfarlane Kate A. , Wong Hoying F. , Mekonnen Ellen , Hicks Matthew , Steele Tom , Gerrard Christine , Hardiman Fiona , McNamara Paul S. , Diggle Peter J. , Carrol Enitan D. 
Published: March 2015

BACKGROUND:
Bacteremia is now an uncommon presentation to the children’s emergency department (ED) but is associated with significant morbidity and mortality. Its evolving etiology may affect the ability of clinicians to initiate timely, appropriate antimicrobial therapy.

METHODS:
A retrospective time series analysis of bacteremia was conducted in the Alder Hey Children’s Hospital ED between 2001 and 2011. Data on significant comorbidities, time to empirical therapy, and antibiotic susceptibility were recorded.

RESULTS:
A total of 575 clinical episodes were identified, and Streptococcus pneumoniae (n = 109), Neisseria meningitidis (n = 96), and Staphylococcus aureus (n = 89) were commonly isolated. The rate of bacteremia was 1.42 per 1000 ED attendances (95% confidence interval: 1.31–1.53). There was an annual reduction of 10.6% (6.6%–14.5%) in vaccine-preventable infections, and an annual increase of 6.7% (1.2%–12.5%) in Gram-negative infections. The pneumococcal conjugate vaccine was associated with a 49% (32%–74%) reduction in pneumococcal bacteremia. The rate of health care–associated bacteremia increased from 0.17 to 0.43 per 1000 ED attendances (P = .002). Susceptibility to empirical antibiotics was reduced (96.3%–82.6%; P &lt; .001). Health care–associated bacteremia was associated with an increased length of stay of 3.9 days (95% confidence interval: 2.3–5.8). Median time to antibiotics was 184 minutes (interquartile range: 63–331) and 57 (interquartile range: 27–97) minutes longer in Gram-negative bacteremia than in vaccine-preventable bacteremia.

CONCLUSIONS:
Changes in the etiology of pediatric bacteremia have implications for prompt, appropriate empirical treatment. Increasingly, pediatric bacteremia in the ED is health care associated, which increases length of inpatient stay. Prompt, effective antimicrobial administration requires new tools to improve recognition, in addition to continued etiological surveillance.
Using Quality Improvement to Reduce Continuous Pulse Oximetry Use in Children With Wheezing
Authors: Schondelmeyer Amanda C. , Simmons Jeffrey M. , Statile Angela M. , Hofacer Kelsey E. , Smith Rebecca , Prine Lori , Brady Patrick W. 
Published: March 2015

BACKGROUND AND OBJECTIVES:
Clinicians commonly use continuous pulse oximetry (CPOx) for hospitalized children with respiratory illnesses. The Choosing Wisely initiative recommended discontinuing CPOx for children on room air. We used quality improvement methods to reduce time on CPOx in patients with wheezing.

METHODS:
Our project took place on 1 unit of a children’s hospital. We developed consensus-based criteria for CPOx discontinuation. Interventions included education, a checklist used during nurse handoff, and discontinuation criteria incorporated into order sets. We collected data on a second unit where we did not actively intervene to assess for secular trends and negative consequences of shorter monitoring. We followed time until medically ready, ICU transfers, hospital revisits, and medical emergency team calls on both units. We tracked the impact of interventions by using run charts and statistical process control charts.

RESULTS:
Median time per week on CPOx after meeting goals decreased from 10.7 hours to 3.1 hours on the intervention unit. Median time per week on CPOx on the control unit decreased from 11.5 hours to 6.9 hours. There was no decrease in time until medically ready on either unit. The percentage of patients needing transfer, revisit, or medical emergency team call was similar on both units.

CONCLUSIONS:
With interventions focused on clarity and awareness of CPOx discontinuation criteria, we decreased time on CPOx; however, we saw no impact on time until medically ready. We expect that other centers could use analogous methods to standardize and reduce oxygen monitoring to meet Choosing Wisely recommendations.
Prediction Models for Neonatal Health Care–Associated Sepsis: A Meta-analysis
Authors: Verstraete Evelien Hilde , Blot Koen , Mahieu Ludo , Vogelaers Dirk , Blot Stijn 
Published: March 2015

BACKGROUND AND OBJECTIVES:
Blood culture is the gold standard to diagnose bloodstream infection but is usually time-consuming. Prediction models aim to facilitate early preliminary diagnosis and treatment. We systematically reviewed prediction models for health care–associated bloodstream infection (HABSI) in neonates, identified superior models, and pooled clinical predictors. Data sources: LibHub, PubMed, and Web of Science.

METHODS:
The studies included designed prediction models for laboratory-confirmed HABSI or sepsis. The target population was a consecutive series of neonates with suspicion of sepsis hospitalized for ≥48 hours. Clinical predictors had to be recorded at time of or before culturing. Methodologic quality of the studies was assessed. Data extracted included population characteristics, total suspected and laboratory-confirmed episodes and definition, clinical parameter definitions and odds ratios, and diagnostic accuracy parameters.

RESULTS:
The systematic search revealed 9 articles with 12 prediction models representing 1295 suspected and 434 laboratory-confirmed sepsis episodes. Models exhibit moderate-good methodologic quality, large pretest probability range, and insufficient diagnostic accuracy. Random effects meta-analysis showed that lethargy, pallor/mottling, total parenteral nutrition, lipid infusion, and postnatal corticosteroids were predictive for HABSI. Post hoc analysis with low-gestational-age neonates demonstrated that apnea/bradycardia, lethargy, pallor/mottling, and poor peripheral perfusion were predictive for HABSI. Limitations include clinical and statistical heterogeneity.

CONCLUSIONS:
Prediction models should be considered as guidance rather than an absolute indicator because they all have limited diagnostic accuracy. Lethargy and pallor and/or mottling for all neonates as well as apnea and/or bradycardia and poor peripheral perfusion for very low birth weight neonates are the most powerful clinical signs. However, the clinical context of the neonate should always be considered.
Off-Label Use of Inhaled Nitric Oxide After Release of NIH Consensus Statement
Authors: Ellsworth Marc A. , Harris Malinda N. , Carey William A. , Spitzer Alan R. , Clark Reese H. 
Published: March 2015

BACKGROUND:Inhaled nitric oxide (iNO) therapy is an off-label medication in infants &lt;34 weeks’ gestational age. In 2011, the National Institutes of Health released a statement discouraging routine iNO use in premature infants. The objective of this study was to describe utilization patterns of iNO in American NICUs in the years surrounding the release of the National Institutes of Health statement. We hypothesized that iNO prescription rates in premature infants have remained unchanged since 2011.METHODS:The Pediatrix Medical Group Clinical Data Warehouse was queried for the years 2009–2013 to describe first exposure iNO use among all admitted neonates stratified by gestational age.RESULTS:Between 2009 and 2013, the rate of iNO utilization in 23- to 29-week neonates increased from 5.03% to 6.19%, a relative increase of 23% (confidence interval: 8%–40%; P = .003). Of all neonates who received iNO therapy in 2013, nearly half were &lt;34 weeks’ gestation, with these infants accounting for more than half of all first exposure iNO days each year of the study period.CONCLUSIONS:The rates of off-label iNO use in preterm infants continue to rise despite evidence revealing no clear benefit in this population. This pattern of iNO prescription is not benign and comes with economic consequences.
A global-local approach to the design of dynamic vibration absorber for damped inverted pendulum structures
Authors: Anh N. D. , Nguyen N. X. 
Published: March 2015

In practice, an inverted pendulum can be used to model many real structures as the arms of robots, soil structures, or fluid structures. However, the study on the design of dynamic vibration absorber for inverted pendulum structures is very limited in the literature. To the best knowledge of the authors, however, there has been no study on the dynamic vibration absorber when the primary inverted pendulum structure is damped. This paper deals with the optimization problem of dynamic vibration absorber for inverted pendulum structures. Two novel findings of the present study are summarized as follows. First, the optimal parameters of dynamic vibration absorber for undamped inverted pendulum structures are given by using \(H_{\infty }\) optimization. Second, the authors suggest a so-called global-local approach to determine approximate expressions for optimal parameters of a pendulum type absorber attached to a damped inverted pendulum structure. Finally, a numerical simulation is done for an example of the articulated tower in the ocean to validate the effectiveness of the results obtained in this work.
Ousadia e redenção: o Instituto de Pesquisa Histórica de José Honório Rodrigues
Authors: Freixo Andre De Lemos 
Published: March 2015

Este artigo analisa um “futuro pretérito”: o Instituto de Pesquisa Histórica (IPH), idealizado por José Honório Rodrigues entre meados da década de 1940 e inícios de 1950. Trata-se de um horizonte não concretizado. Em meio às tensões que marcaram o processo de constituição de uma historiografia profissionalizada no país, o IPH visava inaugurar uma nova fase da história no Brasil. Esse lugar social e institucional centralizaria quase todas as etapas da produção de conhecimento histórico, concorrendo, inclusive, com as Faculdades de Filosofia no que toca à pesquisa e formação de historiadores. Avalio aqui sua proposta bem como o que estaria em jogo para seu idealizador no momento em que formulou seu projeto.
Memórias de um profissional de história
Authors: Ribeiro Júnior José 
Published: March 2015

Dentro do quadro de proposições deste número da revista História da Historiografia, relata-se, de forma concisa, a trajetória de um professor universitário de história. Trata-se de alguém que narra sua licenciatura na USP, sua participação em inícios de cursos de graduação e pós-graduação numa cidade do interior do Estado de São Paulo, inclusive fazendo parte dos primórdios da Universidade Estadual Paulista (UNESP). O autor aborda, também, aspectos de sua vida acadêmica e institucional, relatando, ainda, o processo de sua inserção em linha historiográfica definida. Observe-se, introdutoriamente, que o leitor nem sempre encontrará uma ordem cronológica linear, por força da multifacetada natureza das atividades de um professor universitário de história. Advirto, também, não terem sido feitas as citações bibliográficas completas por entender que escrevo para especialistas do métier de l’historien.
História e memória: origens e desenvolvimento do programa de pós-graduação em História da Universidade Federal Fluminense
Authors: Falcon Francisco 
Published: March 2015

A convite da revista História da Historiografia, Francisco José Calazans Falcon elaborou esta narrativa sobre o desenvolvimento do programa de pós-graduação em história da Universidade Federal Fluminense (UFF). Conjugando história e memória, este exercício de contextualização foi desenvolvido por um profissional que colaborou na criação de diversos programas de pós-graduação no Rio de Janeiro, uma parte significativa do processo de construção da pós-graduação em história no Brasil.
Combates na história atlântica: a historiografia de Joseph E. Inikori
Authors: Lopes Gustavo Acioli 
Published: March 2015

O presente artigo aborda a historiografia do nigeriano Joseph E. Inikori, destacando sua análise de três temas clássicos da história atlântica moderna: o aspecto quantitativo do tráfico transatlântico de escravos, o impacto do tráfico de escravos na África e a relação entre o capitalismo e a escravidão moderna. Apresentam-se os seus argumentos em contraposição a outras abordagens que aqui denominamos “revisionistas”, de forma a ressaltar os principais pontos de discordância que têm marcado os debates no campo referido e a posição de Inikori nele. Argumenta-se, enfim, que suas análises constituem uma tese mais ampla sobre a formação do mundo atlântico desde o séc. XVI até o advento da Revolução Industrial.
El fin de la historia en Hegel y Marx
Authors: Barros Israel Sanmartín 
Published: March 2015

En este trabajo nos centraremos en las construcciones teóricas de Hegel y Marx alrededor de la idea de “fin de la historia” y también en la opinión que han suscitado en los diferentes autores sus ideas finalistas. Jugaremos, así, con las ideas de fin en Hegel y Marx, pero también con las de toda una serie de estudiosos que han polemizado sobre el tema en los últimos años. Partiendo de esas premisas teóricas, el objetivo fundamental de esta investigación es mostrar qué fines de la historia presentan Hegel y Marx y cómo se imbrican el uno en el otro. La idea es mostrar la tradición teórica del término y su genealogía en esos dos autores. Para ello recurriremos a una matriz de análisis descriptiva a fin de localizar cómo y dónde expresan los dos autores la idea de fin de la historia. Tras presentar sus ideas, buscaremos similitudes y diferencias en la arquitectura histórica y teórica de los conceptos de fin de la historia, todo ello partiendo de la idea de que Hegel es el iniciador de dicho concepto y Marx, su continuador. Analizaremos dichas ideas desde una perspectiva teórica.