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1.
Chem Commun (Camb) ; 59(39): 5866-5869, 2023 May 11.
Article in English | MEDLINE | ID: mdl-37089062

ABSTRACT

We report on the synthesis and spectroscopic evidence for a sequence of structural transformations of a new defect-cubane type copper complex, [Cu4(pyalk)4(OAc)4](ClO4)(HNEt3), which acts as a pre-catalyst for water oxidation. In situ and post-catalytic studies showed that the tetrameric complex undergoes a structural transformation into dimeric and monomeric species, induced by water molecules and carbonate anions, respectively. Further, the observed electrocatalytic water oxidation activity has been confirmed to arise from in situ-generated Cu(II) oxidic nanostructures at the electrode interface.

2.
Chem Rev ; 123(9): 6257-6358, 2023 May 10.
Article in English | MEDLINE | ID: mdl-36944098

ABSTRACT

The oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are core steps of various energy conversion and storage systems. However, their sluggish reaction kinetics, i.e., the demanding multielectron transfer processes, still render OER/ORR catalysts less efficient for practical applications. Moreover, the complexity of the catalyst-electrolyte interface makes a comprehensive understanding of the intrinsic OER/ORR mechanisms challenging. Fortunately, recent advances of in situ/operando characterization techniques have facilitated the kinetic monitoring of catalysts under reaction conditions. Here we provide selected highlights of recent in situ/operando mechanistic studies of OER/ORR catalysts with the main emphasis placed on heterogeneous systems (primarily discussing first-row transition metals which operate under basic conditions), followed by a brief outlook on molecular catalysts. Key sections in this review are focused on determination of the true active species, identification of the active sites, and monitoring of the reactive intermediates. For in-depth insights into the above factors, a short overview of the metrics for accurate characterizations of OER/ORR catalysts is provided. A combination of the obtained time-resolved reaction information and reliable activity data will then guide the rational design of new catalysts. Strategies such as optimizing the restructuring process as well as overcoming the adsorption-energy scaling relations will be discussed. Finally, pending current challenges and prospects toward the understanding and development of efficient heterogeneous catalysts and selected homogeneous catalysts are presented.

3.
ACS Appl Mater Interfaces ; 15(1): 806-817, 2023 Jan 11.
Article in English | MEDLINE | ID: mdl-36542810

ABSTRACT

Identifying thermodynamically favorable and stable non-stoichiometric metal oxides is of crucial importance for solar thermochemical (STC) fuel production via two-step redox cycles. The performance of a non-stoichiometric metal oxide depends on its thermodynamic properties, oxygen exchange capacity, and its phase stability under high-temperature redox cycling conditions. Perovskite oxides (ABO3-δ) are being considered as attractive alternatives to the state-of-the-art ceria (CeO2-δ) due to their high thermodynamic and structural tunability. However, perovskite oxides often exhibit low entropy change compared to ceria, as they generally have one only redox active site, leading to lower mass-specific fuel yields. Herein, we investigate cation-deficient Ce-substituted perovskite oxides as a new class of potential redox materials combining the advantages of perovskites and ceria. We newly synthesized the (CexSr1-x)0.95Ti0.5Mn0.5O3-δ (x = 0, 0.10, 0.15, and 0.20; CSTM) series, with dual-redox active sites comprising Ce (at the A-site) and Mn (at the B-site). By introducing a cation deficiency (∼5%), CSTM perovskite oxides with both phase purity (x ≤ 0.15) and high-temperature structural stability under STC redox cycling conditions are obtained. Thermodynamic properties are evaluated by measuring oxygen non-stoichiometry in the temperature range T = 700-1400 °C and the oxygen partial pressure range pO2 = 1-10-4 bar. The results demonstrate that CSTM perovskite oxides exhibit a composition-dependent simultaneous increase of enthalpy and entropy change with increasing Ce-substitution. (Ce0.20Sr0.80)0.95Ti0.5Mn0.5O3-δ (CSTM20) showed a combination of large entropy change of ∼141 J (mol-O)-1 K-1 and moderate enthalpy change of ∼238 kJ (mol-O)-1, thereby creating favorable conditions for thermochemical H2O splitting. Furthermore, the oxidation states and local coordination environment around Mn, Ce, and Ti sites in the pristine and reduced CSTM samples were extensively studied using X-ray absorption spectroscopy. The results confirmed that both Ce (at the A-site) and Mn (at the B-site) centers undergo simultaneous reduction during thermochemical redox cycling.

4.
ACS Nano ; 16(9): 15318-15327, 2022 Sep 27.
Article in English | MEDLINE | ID: mdl-36069492

ABSTRACT

In-depth insights into the structure-activity relationships and complex reaction mechanisms of oxygen evolution reaction (OER) electrocatalysts are indispensable to efficiently generate clean hydrogen through water electrolysis. We introduce a convenient and effective sulfur heteroatom tuning strategy to optimize the performance of active Ni and Fe centers embedded into coordination polymer (CP) catalysts. Operando monitoring then provided the mechanistic understanding as to how exactly our facile sulfur engineering of Ni/Fe-CPs optimizes the local electronic structure of their active centers to facilitate dioxygen formation. The high OER activity of our optimized S-R-NiFe-CPs outperforms the most recent NiFe-based OER electrocatalysts. Specifically, we start from oxygen-deprived Od-R-NiFe-CPs and transform them into highly active Ni/Fe-CPs with tailored sulfur coordination environments and anionic deficiencies. Our operando X-ray absorption spectroscopy analyses reveal that sulfur introduction into our designed S-R-NiFe-CPs facilitates the formation of crucial highly oxidized Ni4+ and Fe4+ species, which generate oxygen-bridged NiIV-O-FeIV moieties that act as the true OER active intermediates. The advantage of our sulfur-doping strategy for enhanced OER is evident from comparison with sulfur-free Od-R-NiFe-CPs, where the formation of essential high-valent OER intermediates is hindered. Moreover, we propose a dual-site mechanism pathway, which is backed up with a combination of pH-dependent performance data and DFT calculations. Computational results support the benefits of sulfur modulation, where a lower energy barrier enables O-O bond formation atop the S-NiIV-O-FeIV-O moieties. Our convenient anionic tuning strategy facilitates the formation of active oxygen-bridged metal motifs and can thus promote the design of flexible and low-cost OER electrocatalysts.

5.
Energy Environ Sci ; 15(2): 727-739, 2022 Feb 16.
Article in English | MEDLINE | ID: mdl-35308298

ABSTRACT

The rational design of efficient electrocatalysts for industrial water splitting is essential to generate sustainable hydrogen fuel. However, a comprehensive understanding of the complex catalytic mechanisms under harsh reaction conditions remains a major challenge. We apply a self-templated strategy to introduce hierarchically nanostructured "all-surface" Fe-doped cobalt phosphide nanoboxes (Co@CoFe-P NBs) as alternative electrocatalysts for industrial-scale applications. Operando Raman spectroscopy and X-ray absorption spectroscopy (XAS) experiments were carried out to track the dynamics of their structural reconstruction and the real catalytically active intermediates during water splitting. Our operando analyses reveal that partial Fe substitution in cobalt phosphides promotes a structural reconstruction into P-Co-O-Fe-P configurations with low-valence metal centers (M0/M+) during the hydrogen evolution reaction (HER). Results from density functional theory (DFT) demonstrate that these in situ reconstructed configurations significantly enhance the HER performance by lowering the energy barrier for water dissociation and by facilitating the adsorption/desorption of HER intermediates (H*). The competitive activity in the oxygen evolution reaction (OER) arises from the transformation of the reconstructed P-Co-O-Fe-P configurations into oxygen-bridged, high-valence CoIV-O-FeIV moieties as true active intermediates. In sharp contrast, the formation of such CoIII/IV-O-FeIII/IV moieties in Co-FeOOH is hindered under the same conditions, which outlines the key advantages of phosphide-based electrocatalysts. Ex situ studies of the as-synthesized reference cobalt sulfides (Co-S), Fe doped cobalt selenides (Co@CoFe-Se), and Fe doped cobalt tellurides (Co@CoFe-Te) further corroborate the observed structural transformations. These insights are vital to systematically exploit the intrinsic catalytic mechanisms of non-oxide, low-cost, and robust overall water splitting electrocatalysts for future energy conversion and storage.

6.
Nat Commun ; 12(1): 5589, 2021 Sep 22.
Article in English | MEDLINE | ID: mdl-34552084

ABSTRACT

Single-atom catalysts with maximum metal utilization efficiency show great potential for sustainable catalytic applications and fundamental mechanistic studies. We here provide a convenient molecular tailoring strategy based on graphitic carbon nitride as support for the rational design of single-site and dual-site single-atom catalysts. Catalysts with single Fe sites exhibit impressive oxygen reduction reaction activity with a half-wave potential of 0.89 V vs. RHE. We find that the single Ni sites are favorable to promote the key structural reconstruction into bridging Ni-O-Fe bonds in dual-site NiFe SAC. Meanwhile, the newly formed Ni-O-Fe bonds create spin channels for electron transfer, resulting in a significant improvement of the oxygen evolution reaction activity with an overpotential of 270 mV at 10 mA cm-2. We further reveal that the water oxidation reaction follows a dual-site pathway through the deprotonation of *OH at both Ni and Fe sites, leading to the formation of bridging O2 atop the Ni-O-Fe sites.

7.
J Am Chem Soc ; 143(37): 15022-15038, 2021 09 22.
Article in English | MEDLINE | ID: mdl-34499506

ABSTRACT

The oxygen evolution reaction (OER) is a key bottleneck step of artificial photosynthesis and an essential topic in renewable energy research. Therefore, stable, efficient, and economical water oxidation catalysts (WOCs) are in high demand and cobalt-based nanomaterials are promising targets. Herein, we tackle two key open questions after decades of research into cobalt-assisted visible-light-driven water oxidation: What makes simple cobalt-based precipitates so highly active-and to what extent do we need Co-WOC design? Hence, we started from Co(NO3)2 to generate a precursor precipitate, which transforms into a highly active WOC during the photocatalytic process with a [Ru(bpy)3]2+/S2O82-/borate buffer standard assay that outperforms state of the art cobalt catalysts. The structural transformations of these nanosized Co catalysts were monitored with a wide range of characterization techniques. The results reveal that the precipitated catalyst does not fully change into an amorphous CoOx material but develops some crystalline features. The transition from the precipitate into a disordered Co3O4 material proceeds within ca. 1 min, followed by further transformation into highly active disordered CoOOH within the first 10 min. Furthermore, under noncatalytic conditions, the precursor directly transforms into CoOOH. Moreover, fast precipitation and isolation afford a highly active precatalyst with an exceptional O2 yield of 91% for water oxidation with the visible-light-driven [Ru(bpy)3]2+/S2O82- assay, which outperforms a wide range of carefully designed Co-containing WOCs. We thus demonstrate that high-performance cobalt-based OER catalysts indeed emerge effortlessly from a self-optimization process favoring the formation of Co(III) centers in all-octahedral environments. This paves the way to new low-maintenance flow chemistry OER processes.

8.
Angew Chem Int Ed Engl ; 60(34): 18380-18396, 2021 Aug 16.
Article in English | MEDLINE | ID: mdl-33761172

ABSTRACT

We review the current understanding of charge carriers in model hematite photoanodes at different stages. The origin of charge carriers is discussed based on the electronic structure and absorption features, highlighting the controversial assignment of the electronic transitions near the absorption edge. Next, the dynamic evolution of charge carriers is analyzed both on the ultrafast and on the surface reaction timescales, with special emphasis on the arguable spectroscopic assignment of electrons/holes and their kinetics. Further, the competitive charge transfer centers at the solid-liquid interface are reviewed, and the chemical nature of relevant surface states is updated. Finally, an overview on the function of widely employed surface cocatalysts is given to illustrate the complex influence of physiochemical modifications on the charge carrier dynamics. The understanding of charge carriers from their origin all the way to their interfacial transfer is vital for the future of photoanode design.

9.
Nat Commun ; 12(1): 255, 2021 Jan 11.
Article in English | MEDLINE | ID: mdl-33431853

ABSTRACT

Understanding the function of surface states on photoanodes is crucial for unraveling the underlying reaction mechanisms of water oxidation. For hematite photoanodes, only one type of surface states with higher oxidative energy (S1) has been proposed and verified as reaction intermediate, while the other surface state located at lower potentials (S2) was assigned to inactive or recombination sites. Through employing rate law analyses and systematical (photo)electrochemical characterizations, here we show that S2 is an active reaction intermediate for water oxidation as well. Furthermore, we demonstrate that the reaction kinetics and dynamic interactions of both S1 and S2 depend significantly on operational parameters, such as illumination intensity, nature of the electrolyte, and applied potential. These insights into the individual reaction kinetics and the interplay of both surface states are decisive for designing efficient photoanodes.

10.
ACS Nano ; 14(10): 13279-13293, 2020 Oct 27.
Article in English | MEDLINE | ID: mdl-33048543

ABSTRACT

Single atom catalysts (SACs) are ideal model systems in catalysis research. Here we employ SACs to address the fundamental catalytic challenge of generating well-defined active metal centers to elucidate their interactions with coordinating atoms, which define their catalytic performance. We introduce a soft-landing molecular strategy for tailored SACs based on metal phthalocyanines (MPcs, M = Ni, Co, Fe) on graphene oxide (GO) layers to generate well-defined model targets for mechanistic studies. The formation of electronic channels through π-π conjugation with the graphene sheets enhances the MPc-GO performance in both oxygen evolution and reduction reactions (OER and ORR). Density functional theory (DFT) calculations unravel that the outstanding ORR activity of FePc-GO among the series is due to the high affinity of Fe atoms toward O2 species. Operando X-ray absorption spectroscopy and DFT studies demonstrate that the OER performance of the catalysts relates to thermodynamic or kinetic control at low- or high-potential ranges, respectively. We furthermore provide evidence that the participation of ligating N and C atoms around the metal centers provides a wider selection of active OER sites for both NiPc-GO and CoPc-GO. Our strategy promotes the understanding of coordination-activity relationships of high-performance SACs and their optimization for different processes through tailored combinations of metal centers and suitable ligand environments.

11.
Rev. colomb. nefrol. (En línea) ; 7(1): 97-112, ene.-jun. 2020. tab, graf
Article in Spanish | LILACS, COLNAL | ID: biblio-1144377

ABSTRACT

Resumen La acidosis tubular renal distal es causada por un defecto en la excreción de iones de hidrogeno a nivel tubular distal, lo que aumenta el pH de la orina y disminuye el pH plasmático; esta es una enfermedad con varias manifestaciones clínicas asociadas. En este artículo se hace una revisión profunda sobre la acidosis tubular renal distal y se presenta el caso de tres hermanos (dos hombres y una mujer) con la entidad, siendo este uno de los primeros casos familiares reportados en Colombia. Los tres pacientes recibieron el diagnóstico durante el período de lactancia, presentaron nefrocalcinosis y tuvieron buena respuesta a la terapia con álcali iniciada de forma temprana, logrando eventualmente su suspensión. De manera curiosa, uno de los pacientes también presentó deficiencia de mevalonato quinasa con hiperinmunoglobulinemia D, una alteración no descrita con anterioridad. Esta asociación y la aparente falta de necesidad de continuar el manejo con álcali son atípicas a la luz del conocimiento actual, mereciendo especial consideración.


Abstract The distal renal tubular acidosis presents due to a defect in the excretion of hydrogen ions at the distal tubular level, causing an increase in the pH of the urine and a decrease in the plasma pH, with several associated clinical manifestations. This article makes a thorough review of distal renal tubular acidosis and presents the case of three siblings with the entity, two men and one woman, this being one of the first family cases reported in Colombia. All three received the diagnosis during the lactation period, presented nephrocalcinosis and good response to the alkali therapy started early, eventually achieving their suspension. Interestingly, one of them also presented deficiency mevalonate-kinase with hiperinmunoglobulinemia D, alteration not previously described. This association and the apparent lack of need for continued management with alkali are atypical in the light of current knowledge, deserving special consideration.


Subject(s)
Humans , Male , Female , Acidosis, Renal Tubular , Patients , Colombia , Siblings , Genetics , Nephrocalcinosis
12.
Rev. Fac. Med. (Bogotá) ; 68(1): 143-147, Jan.-Mar. 2020. tab, graf
Article in English | LILACS-Express | LILACS | ID: biblio-1125618

ABSTRACT

Abstract Introduction: Henoch Schönlein purpura (HSP) is the most common type of vasculitis in childhood. HSP affects small blood vessels, and it rarely leads to serious complications such as bullous small vessel vasculitis, as it occurred in the case presented here. Case presentation: 5-year-old male who was brought to a primary healthcare center due to having arthralgia and purple skin lesions on his lower limbs. After the patient was diagnosed with HSP, he developed bullous lesions, so he was hospitalized and analgesic and topical management was started. During his hospital stay, the patient's renal function was monitored, and since he did not experience other complications, he was discharged. Conclusion: The available literature on HSP suggests that its cutaneous bullous manifestation rarely occurs in pediatric population and that, unlike normal HSP cases, it is not always associated with renal and/or gastrointestinal involvement. However, regardless of the dermatological severity of this type of vasculitis, the function of the gastrointestinal and renal systems must be always monitored in these patients.


Resumen Introducción. La púrpura Henoch-Schönlein (PHS) es la forma más común de vasculitis en la infancia; esta se da en pequeños vasos sanguíneos y no es frecuente que genere complicaciones graves como la vasculitis bullosa, tal como sucedió en el caso que se presenta a continuación. Presentación del caso. Paciente masculino de cinco años que fue traído a un centro de atención primaria con un cuadro clínico consistente en artralgias y aparición de lesiones purpúricas en miembros inferiores. Luego de ser diagnosticado con PHS, presentó lesiones bullosas, por lo que fue hospitalizado y se inició manejo analgésico y tópico; durante su estadía en el hospital se vigiló su función renal y, ya que no presentó otras complicaciones, se dio de alta. Conclusión. Las publicaciones disponibles sobre PHS sugieren que su presentación cutánea bullosa en pediatría no es frecuente y que no siempre se relaciona con un compromiso renal y/o gastrointestinal como la variante clásica; sin embargo, siempre debe vigilarse la función de estos sistemas sin importar la gravedad dérmica de esta vasculitis.

13.
Rev. Fac. Med. (Bogotá) ; 67(4): 715-718, Oct.-Dec. 2019. graf
Article in English | LILACS-Express | LILACS | ID: biblio-1092002

ABSTRACT

Abstract Disseminated staphylococcal disease comprises a set of clinical manifestations secondary to multiple organ invasion that may range from cellulitis to sepsis. In pediatrics, the most common complications are osteoarticular and cutaneous infection; however, this article presents rare manifestations such as glomerulonephritis and thrombotic phenomena. This is the report of two cases of previously healthy adolescents: one presented with osteomyelitis and kidney injury, and the other, with lower limb cellulitis and respiratory deterioration with septic pulmonary embolism. The diagnostic process and additional management are described, highlighting the role of oxacillin in therapy. This article aims to highlight the importance of considering the rare manifestations of S. aureus infection, when the clinical evolution is abnormal, in order to initiate a timely treatment and get a better prognosis.


Resumen La enfermedad diseminada por Staphylococcus aureus comprende un conjunto de manifestaciones clínicas secundarias a su invasión multiorgánica que van desde celulitis hasta sepsis. En pediatría, las complicaciones más comunes son las infecciones osteoarticular y cutánea; sin embargo, este artículo presenta algunas manifestaciones poco frecuentes, tales como la glomerulonefritis y los fenómenos trombóticos. Se presentan dos casos de pacientes adolescentes previamente sanos: el primero cursó con osteomielitis y lesión renal, y el segundo, con celulitis de miembro inferior, deterioro respiratorio y embolismo pulmonar séptico documentado. Se describe el proceso diagnóstico y manejos adicionales, y se resalta el papel de la oxacilina en la terapia. Este artículo pretende destacar la importancia de considerar las manifestaciones infrecuentes de la infección por S. aureus cuando la evolución clínica sea anormal para instaurar el tratamiento oportuno y propender por un mejor pronóstico.

14.
Arch Plast Surg ; 46(3): 262-266, 2019 May.
Article in English | MEDLINE | ID: mdl-30931553

ABSTRACT

Transsexual individuals with gender dysphoria or gender identity disorder are rare, with a prevalence reported to range from 0.002% to 0.014%. Studies have shown that mastectomy yields significant improvements in body image and self-esteem in female-to-male transsexual patients. In patients with grade III breast ptosis, mastectomy with a nipple-areolar complex (NAC) graft is the most commonly used technique, although it has several disadvantages. In the case described herein, a bilateral mastectomy preserving the NAC in an inferior pedicle was performed. Additionally, a thin superior thoracic dermal-fat flap was preserved and eventually sutured at the previous inframammary fold, preventing an inverted T scar. This case shows the advantage of this technique for preserving the blood supply and innervation of the NAC, with a low hypopigmentation risk. Furthermore, in this technique, the patch effect does not impair the results of the NAC graft, and there is no need to use an inverted T scar that may result in thoracic feminization.

15.
Rev. Fac. Med. (Bogotá) ; 66(1): 125-128, ene.-mar. 2018. graf
Article in Spanish | LILACS | ID: biblio-896834

ABSTRACT

Resumen Se presenta el caso de un paciente masculino de 14 años de edad, con antecedente de dos intervenciones quirúrgicas debidas a la presencia de una masa a nivel sublingual -la primera a los 8 meses de edad y la segunda a los 13 años- y sin información de estudios histopatológicos. Cerca de 8 meses después de la última intervención quirúrgica es valorado por el Servicio de Cirugía Maxilofacial de la Fundación Hospital Pediátrico de La Misericordia en Bogotá D.C., Colombia, por crecimiento acelerado de la misma lesión y por problemas en la deglución y el lenguaje. En la revisión del paciente se encuentra una masa importante sublingual, dificultad en el lenguaje, deformidad mandibular y alteraciones en la mordida, por lo que se decide intervenir quirúrgicamente de nuevo. El resultado de la biopsia es un tumor mesenquimal benigno característico de neurofibroma, que por su ubicación sugiere probable compromiso del nervio hipogloso.


Abstract This article presents the case of a 14-year-old male patient, with a history of two surgical procedures due to the presence of a mass at sublingual level -the first performed at the age of 8 months and the second at 13 the age of years- and without information of histopathological studies. About 8 months after the last surgical procedure, the patient was assessed by the Maxillofacial Surgery Service of the Fundación Hospital Pediátrico de La Misericordia, in Bogotá D.C. - Colombia, due to the rapid growth of the same lesion and swallowing and language disorders. On physical examination, a significant sublingual mass, difficulty in language, mandibular deformity and malocclusion were observed, so a new surgical intervention was indicated. The result of the biopsy revealed a benign mesenchymal tumor, typically seen in neurofibroma, which suggested a possible involvement of the hypoglossal nerve due to its location.

16.
Rev. Fac. Med. (Bogotá) ; 65(4): 679-682, Dec. 2017. graf
Article in Spanish | LILACS | ID: biblio-896780

ABSTRACT

Resumen Los abscesos renales y perirrenales hacen parte de un grupo de infecciones poco frecuentes en pediatría que comprometen el parénquima renal y el espacio perinefrítico. Estas entidades no tienen una clínica específica y, por lo tanto, se deben sospechar en todos los pacientes con infección urinaria que no respondan a la terapia antimicrobiana adecuada. De su apropiado diagnóstico dependerá la evolución y el pronóstico del paciente. Si bien el drenaje percutáneo mediante radiología intervencionista es un procedimiento descrito para el tratamiento de esta patología en los adultos, este puede hacer parte del manejo en pediatría. En este artículo, se presenta el caso clínico de un niño de tres años con diagnóstico de absceso renal y su manejo en un centro pediátrico de Bogotá, junto a una revisión actualizada de esta patología.


Abstract Renal and perinephric abscesses are part of a group of rare pediatric infections that compromise the renal parenchyma and the perinephritic space. These entities do not have a specific clinical picture and, therefore, should be suspected in all patients with urinary tract infection that does not respond to antimicrobial therapy. The evolution and prognosis of the patient depend on appropriate diagnosis. Although percutaneous abscess drainage by interventional radiology is indicated for the treatment of this pathology in adults, it could also be considered for pediatric management. This article reports the clinical case of a three-year-old child diagnosed with renal abscess, who was treated in a pediatric center of Bogotá, as well as an updated review of this pathology.

17.
Rev. Fac. Med. (Bogotá) ; 65(3): 531-535, July-Sept. 2017. tab, graf
Article in English | LILACS | ID: biblio-896755

ABSTRACT

Abstract This paper reports the case of a toddler with chronic stridor of four months of evolution, treated several times by micro-nebulization (MNB) with beta 2, adrenergics, O2 and corticosteroids with partial improvement. The patient did not have complementary studies nor a clear history of foreign body aspiration (FB). During the last visit to the ER, a neck X-ray revealed a stippling sign in the upper airway. A bronchoscopy was performed, and a sharp foreign body (fishbone) was found in the upper airway, which was subsequently removed. This case is reported due to the unusual evolution of the foreign body in the upper airway, which manifested as a chronic stridor that resolved without further complications.


Resumen Se presenta el caso de una paciente prescolar con estridor crónico de 4 meses de evolución, tratada varias veces mediante micronebulizaciones (MNB) con beta 2, adrenérgicos, O2 y corticoides con mejoría parcial, sin estudios complementarios ni antecedentes claros de atoramiento con cuerpo extraño (CE). Además, se realizó una radiografía de cuello (Rx) que reveló la presencia de imagen en punta de lápiz traqueal y una broncoscopia que comprobó la existencia de un cuerpo extraño puntiagudo (espina de pescado) en la vía aérea superior. Este caso se reportó por su inusual presentación, pues es un CE en la vía aérea superior que se manifestó con estridor crónico, sin mayores complicaciones.

18.
Rev. Fac. Med. (Bogotá) ; 64(3): 551-553, July-Sept. 2016. tab
Article in English | LILACS | ID: biblio-956768

ABSTRACT

Abstract This paper presents the case of an 11 year-old male who attended the Internal Medicine Service at a high complexity pediatric hospital. Initially, the patient attended due to a clinical profile consisting of autoimmune hemolytic anemia that was partially responsive to steroid treatment and, after exhaustive complimentary analysis, was associated to a Hodgkin lymphoma. Similar cases found in the scientific literature were reviewed in order to analyze this case. Through this paper, the authors intend to remind the medical community about the importance of a prompt and deep study of all autoimmune hemolytic anemia cases found in pediatric patients, without overlooking possible malignant causes related to this condition such as a lymphoproliferative disorder. Thus, before diagnosing a hemolytic anemia as idiopathic, the practitioner must be certain that the condition is not a clinical manifestation of an underlying disease.


Resumen Se presenta el caso de un niño de 11 años atendido en el servicio de Medicina Interna de una institución pediátrica de alto nivel de complejidad. El paciente consultó por un cuadro de anemia hemolítica autoinmune que respondió parcialmente al tratamiento con esteroides y luego de los estudios complementarios se encontró asociada a un linfoma Hodgkin. Se revisaron casos similares en la literatura y se hizo un análisis al respecto. A través de este artículo se recuerda e insiste en que toda anemia hemolítica en niños se debe estudiar de forma pronta, profunda y sin descuidar posibles causas malignas relacionadas como una enfermedad linfoproliferativa; por lo tanto, antes de declarar una anemia hemolítica como idiopática, se debe estar seguro de que no se trata de una expresión clínica de otra enfermedad de base.

19.
Rev. Fac. Med. (Bogotá) ; 64(1): 137-147, ene.-mar. 2016. ilus, tab
Article in Spanish | LILACS | ID: lil-779675

ABSTRACT

El examen general de orina (EGO) es una biopsia líquida renal que ofrece excelente información acerca de la función renal y de los equilibrios ácido-base e hidroelectrolítico; también puede aportar datos sobre alteraciones metabólicas y de patologías renales y extra-renales. El propósito de esta revisión es describir los contenidos más importantes del examen general de orina para que el médico pediatra los utilice, interprete sus resultados correctamente y logre establecer un diagnóstico y tratamiento adecuado y oportuno de las patologías.


Urinalysis (EGO for its acronym in Spanish) is a renal liquid biopsy that provides excellent information on renal function and acid-base and electrolyte balances. It can also provide data on metabolic alterations and renal and extra-renal diseases. The purpose of this review is to describe the most important contents of urinalysis so the pediatrician can correctly interpret its results and establish an appropriate and timely diagnosis and treatment of diseases.

20.
Rev. Fac. Med. (Bogotá) ; 64(1): 151-154, ene.-mar. 2016. ilus, tab
Article in Spanish | LILACS | ID: lil-779677

ABSTRACT

El absceso del músculo psoas es una piomiositis infrecuente en la población pediátrica, convirtiéndose en un gran reto diagnóstico. Esta condición debe sospecharse en todo niño con fiebre, malestar general o dolor abdominal, lumbar o de cadera con evolución mayor a una semana. Suele confundirse con artritis séptica u otras enfermedades osteomusculares, por lo que se requiere de la realización de imágenes diagnósticas; el desconocimiento de esta patología retrasa el inicio del tratamiento y genera gran morbimortalidad. Se presenta un caso atendido en un centro hospitalario pediátrico de tercer nivel de Bogotá, D.C. y se hace una revisión de la literatura enfatizando sus claves diagnósticas y el manejo terapéutico.


Psoas Abscess is a pyomyositis rarely present, which in turn makes its diagnosis a real challenge. This condition must be a differential diagnosis in children presenting fever, general malaise, lumbalgia, abdominal or hip pain for more than a week. It is frequently confused with septic arthritis or other musculoskeletal diseases, which is why radiographic studies or ultrasonography are necessary. Unawareness of this pathology delays its treatment, thus producing high levels of morbidity and mortality. A clinical case treated in a pediatric hospital from Bogotá, Colombia, is presented, as well as a literature review emphasizing in Psoas Abscess key issues and treatment.

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