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1.
Sci Rep ; 9(1): 4142, 2019 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-30858461

RESUMO

We report a simple, single-cycle synthetic method for forming highly-crystalline, micron-sized monolayer domains of phase-pure MoS2. This method combines liquid chemistry with discrete, layer-by-layer deposition from a novel Mo precursor. Single-crystalline MoS2 with domain sizes up to 100 µm have been obtained and characterised by optical and electron microscopy as well as Raman and photoluminescence spectroscopy.

2.
ACS Appl Mater Interfaces ; 11(15): 14239-14248, 2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-30920198

RESUMO

Growth of the large-sized and high-quality MoS2 single crystals for high-performance low-power electronic applications is an important step to pursue. Despite the significant improvement made in minimizing extrinsic MoS2 contact resistance based on interfacial engineering of the devices, the electron mobility of field-effect transistors (FETs) made of a synthetic monolayer MoS2 is yet far below the expected theoretical values, implying that the MoS2 crystal quality needs to be further improved. Here, we demonstrate the high-performance two-terminal MoS2 FETs with room-temperature electron mobility up to ∼90 cm2 V-1 s-1 based on the sulfurization growth of the bifunctional precursor, sodium molybdate dihydrate. This unique transition-metal precursor, serving as both the crystalline Mo source and seed promotor (sodium), could facilitate the lateral growth of the highly crystalline monolayer MoS2 crystals (edge length up to ∼260 µm). Substrate surface treatment with oxygen plasma prior to the deposition of the Mo precursor is fundamental to increase the wettability between the Mo source and the substrate, promoting the thinning and coalescence of the source clusters during the growth of large-sized MoS2 single crystals. The control of growth temperature is also an essential step to grow a strictly monolayer MoS2 crystal. A proof-of-concept for thermoelectric device integration utilizing monolayer MoS2 sheds light on its potential in low-voltage and self-powered electronics.

3.
Small ; 15(8): e1803529, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30663255

RESUMO

A facile approach for the synthesis of Au- and Pt-decorated CuInS2 nanocrystals (CIS NCs) as sensitizer materials on the top of MoS2 bilayers is demonstrated. A single surfactant (oleylamine) is used to prepare such heterostructured noble metal decorated CIS NCs from the pristine CIS. Such a feasible way to synthesize heterostructured noble metal decorated CIS NCs from the single surfactant can stimulate the development of the functionalized heterostructured NCs in large scale for practical applications such as solar cells and photodetectors. Photodetectors based on MoS2 bilayers with the synthesized nanocrystals display enhanced photocurrent, almost 20-40 times higher responsivity and the On/Off ratio is enlarged one order of magnitude compared with the pristine MoS2 bilayers-based photodetectors. Remarkably, by using Pt- or Au-decorated CIS NCs, the photocurrent enhancement of MoS2 photodetectors can be tuned between blue (405 nm) to green (532 nm). The strategy described here acts as a perspective to significantly improve the performance of MoS2 -based photodetectors with the controllable absorption wavelengths in the visible light range, showing the feasibility of the possible color detection.

4.
Small ; 14(19): e1800032, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29635730

RESUMO

The formation of PtSe2 -layered films is reported in a large area by the direct plasma-assisted selenization of Pt films at a low temperature, where temperatures, as low as 100 °C at the applied plasma power of 400 W can be achieved. As the thickness of the Pt film exceeds 5 nm, the PtSe2 -layered film (five monolayers) exhibits a metallic behavior. A clear p-type semiconducting behavior of the PtSe2 -layered film (≈trilayers) is observed with the average field effective mobility of 0.7 cm2 V-1 s-1 from back-gated transistor measurements as the thickness of the Pt film reaches below 2.5 nm. A full PtSe2 field effect transistor is demonstrated where the thinner PtSe2 , exhibiting a semiconducting behavior, is used as the channel material, and the thicker PtSe2 , exhibiting a metallic behavior, is used as an electrode, yielding an ohmic contact. Furthermore, photodetectors using a few PtSe2 -layered films as an adsorption layer synthesized at the low temperature on a flexible substrate exhibit a wide range of absorption and photoresponse with the highest photocurrent of 9 µA under the laser wavelength of 408 nm. In addition, the device can maintain a high photoresponse under a large bending stress and 1000 bending cycles.

5.
ACS Appl Mater Interfaces ; 10(11): 9645-9652, 2018 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-29309121

RESUMO

Direct reduction of metal oxides into a few transition metal dichalcogenide (TMDCs) monolayers has been recently explored as an alternative method for large area and uniform deposition. However, not many studies have addressed the characteristics and requirement of the metal oxides into TMDCs by the selenization/sulfurization processes, yielding a wide range of outstanding properties to poor electrical characteristics with nonuniform films. The large difference implies that the process is yet not fully understood. In particular, the selenization/sulfurization at low temperature leads to poor crystallinity films with poor electrical performance, hindering its practical development. A common approach to improve the quality of the selenized/sulfurized films is by further increasing the process temperature, thus requiring additional transfer in order to explore the electrical properties. Here, we show that by finely tuning the quality of the predeposited oxide the selenization/sulfurization temperature can be largely decreased, avoiding major substrate damage and allowing direct device fabrication. The direct relationship between the role of selecting different metal oxides prepared by e-beam evaporation and reactive sputtering and their oxygen deficiency/vacancy leading to quality influence of TMDCs was investigated in detail. Because of its outstanding physical properties, the formation of tungsten diselenide (WSe2) from the reduction of tungsten oxide (WO x) was chosen as a model for proof of concept. By optimizing the process parameters and the selection of metal oxides, layered WSe2 films with controlled atomic thickness can be demonstrated. Interestingly, the domain size and electrical properties of the layered WSe2 films are highly affected by the quality of the metal oxides, for which the layered WSe2 film with small domains exhibits a metallic behavior and the layered WSe2 films with larger domains provides clear semiconducting behavior. Finally, an 8'' wafer scale-layered WSe2 film was demonstrated, giving a step forward in the development of 2D TMDC electronics in the industry.

6.
ACS Nano ; 11(9): 8768-8776, 2017 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-28753274

RESUMO

Integration of strain engineering of two-dimensional (2D) materials in order to enhance device performance is still a challenge. Here, we successfully demonstrated the thermally strained band gap engineering of transition-metal dichalcogenide bilayers by different thermal expansion coefficients between 2D materials and patterned sapphire structures, where MoS2 bilayers were chosen as the demonstrated materials. In particular, a blue shift in the band gap of the MoS2 bilayers can be tunable, displaying an extraordinary capability to drive electrons toward the electrode under the smaller driven bias, and the results were confirmed by simulation. A model to explain the thermal strain in the MoS2 bilayers during the synthesis was proposed, which enables us to precisely predict the band gap-shifted behaviors on patterned sapphire structures with different angles. Furthermore, photodetectors with enhancement of 286% and 897% based on the strained MoS2 on cone- and pyramid-patterned sapphire substrates were demonstrated, respectively.

7.
Adv Mater ; 28(44): 9831-9838, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27717140

RESUMO

The necessity for new sources for greener and cleaner energy production to replace the existing ones has been increasingly growing in recent years. Of those new sources, the hydrogen evolution reaction has a large potential. In this work, for the first time, MoSe2 /Mo core-shell 3D-hierarchical nanostructures are created, which are derived from the Mo 3D-hierarchical nanostructures through a low-temperature plasma-assisted selenization process with controlled shapes grown by a glancing angle deposition system.

8.
Nano Lett ; 16(4): 2463-70, 2016 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-26906714

RESUMO

Although chemical vapor deposition is the most common method to synthesize transition metal dichalcogenides (TMDs), several obstacles, such as the high annealing temperature restricting the substrates used in the process and the required transfer causing the formation of wrinkles and defects, must be resolved. Here, we present a novel method to grow patternable two-dimensional (2D) transition metal disulfides (MS2) directly underneath a protective coating layer by spin-coating a liquid chalcogen precursor onto the transition metal oxide layer, followed by a laser irradiation annealing process. Two metal sulfides, molybdenum disulfide (MoS2) and tungsten disulfide (WS2), are investigated in this work. Material characterization reveals the diffusion of sulfur into the oxide layer prior to the formation of the MS2. By controlling the sulfur diffusion, we are able to synthesize continuous MS2 layers beneath the top oxide layer, creating a protective coating layer for the newly formed TMD. Air-stable and low-power photosensing devices fabricated on the synthesized 2D WS2 without the need for a further transfer process demonstrate the potential applicability of TMDs generated via a laser irradiation process.

9.
Phys Chem Chem Phys ; 17(33): 21389-93, 2015 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-26220549

RESUMO

Germanene layers with lonsdaleite structure has been synthesized from a SiGe thin film for the first time using a N2 plasma-assisted process in this investigation. Multi-layered germanene can be directly observed, and the derived lattice parameters are nearly consistent with the theoretical results. Furthermore, large-scale multi-layered germanene has also been demonstrated for applications.

10.
ACS Appl Mater Interfaces ; 7(25): 13723-7, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-26070035

RESUMO

Two-dimensional layered materials such as graphene, transition metal dichalcogenides, and black phosphorus have demonstrated outstanding properties due to electron confinement as the thickness is reduced to atomic scale. Among the phosphorus allotropes, black phosphorus, and violet phosphorus possess layer structure with the potential to be scaled down to atomically thin film. For the first time, the plasma-assisted synthesis of atomically layered violet phosphorus has been achieved. Material characterization supports the formation of violet phosphorus/InN over InP substrate where the layer structure of violet phosphorus is clearly observed. The identification of the crystal structure and lattice constant ratifies the formation of violet phosphorus indeed. The critical concept of this synthesis method is the selective reaction induced by different variations of Gibbs free energy (ΔG) of reactions. Besides, the Hall mobility of the violet phosphorus on the InP substrate greatly increases over the theoretical values of InP bulk material without much reduction in the carrier concentration, suggesting that the mobility enhancement results from the violet phosphorus layers. Furthermore, this study demonstrates a low-cost technique with high compatibility to synthesize the high-mobility atomically layered violet phosphorus and open the space for the study of the fundamental properties of this intriguing material as a new member of the fast growing family of 2D crystals.

11.
ACS Nano ; 9(4): 4346-53, 2015 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-25768931

RESUMO

Recently, a few attempts to synthesize monolayers of transition metal dichalcogenides (TMDs) using the chemical vapor deposition (CVD) process had been demonstrated. However, the development of alternative processes to synthesize TMDs is an important step because of the time-consuming, required transfer and low thermal efficiency of the CVD process. Here, we demonstrate a method to achieve few-layers WSe2 on an insulator via laser irradiation assisted selenization (LIAS) process directly, for which the amorphous WO3 film undergoes a reduction process in the presence of selenium gaseous vapors to form WSe2, utilizing laser annealing as a heating source. Detailed growth parameters such as laser power and laser irradiation time were investigated. In addition, microstructures, optical and electrical properties were investigated. Furthermore, a patternable WSe2 concept was demonstrated by patterning the WO3 film followed by the laser irradiation. By combining the patternable process, the transfer-free WSe2 back gate field effect transistor (FET) devices are realized on 300 nm-thick SiO2/P(+)Si substrate with extracted field effect mobility of ∼0.2 cm(2) V(-1) s(-1). Similarly, the reduction process by the laser irradiation can be also applied for the synthesis of other TMDs such as MoSe2 from other metal oxides such as MO3 film, suggesting that the process can be further extended to other TMDs. The method ensures one-step process to fabricate patternable TMDs, highlighting the uniqueness of the laser irradiation for the synthesis of different TMDs.

12.
Small ; 11(25): 3017-27, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25808659

RESUMO

Despite the vast progress in chemical vapor deposition (CVD) graphene grown on metals, the transfer process is still a major bottleneck, being not devoid of wrinkles and polymer residues. In this paper, a structure is introduced to directly synthesize few layer graphene on insulating substrates by a laser irradiation heating process. The segregation of graphene layers can be manipulated by tuning the metal layer thickness and laser power at different scanning rates. Graphene deposition and submicrometer patterning resolution can be achieved by patterning the intermediate metal layer using standard lithography methods in order to overcome the scalability issue regardless the resolution of the laser beam. The systematic analysis of the process based on the formation of carbon microchannels by the laser irradiation process can be extended to several materials, thicknesses, and methods. Furthermore, hole and electron mobilities of 500 and 950 cm(2) V(-1) s(-1) are measured. The laser-synthesized graphene is a step forward along the direct synthesis route for graphene on insulators that meets the criteria for photonics and electronics.

13.
Nanoscale ; 7(5): 1678-87, 2015 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-25423257

RESUMO

Chemical vapour deposition of graphene was the preferred way to synthesize graphene for multiple applications. However, several problems related to transfer processes, such as wrinkles, cleanness and scratches, have limited its application at the industrial scale. Intense research was triggered into developing alternative synthesis methods to directly deposit graphene on insulators at low cost with high uniformity and large area. In this work, we demonstrate a new concept to directly achieve growth of graphene on non-metal substrates. By exposing an amorphous carbon (a-C) film in Cu gaseous molecules after annealing at 850 °C, the carbon (a-C) film surprisingly undergoes a noticeable transformation to crystalline graphene. Furthermore, the thickness of graphene could be controlled, depending on the thickness of the pre-deposited a-C film. The transformation mechanism was investigated and explained in detail. This approach enables development of a one-step process to fabricate electrical devices made of all carbon material, highlighting the uniqueness of the novel approach for developing graphene electronic devices. Interestingly, the carbon electrodes made directly on the graphene layer by our approach offer a good ohmic contact compared with the Schottky barriers usually observed on graphene devices using metals as electrodes.

14.
Nanoscale ; 6(22): 13861-9, 2014 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-25307846

RESUMO

Graphene, a two-dimensional material with honeycomb arrays of carbon atoms, has shown outstanding physical properties that make it a promising candidate material for a variety of electronic applications. To date, several issues related to the material synthesis and device fabrication need to be overcome. Despite the fact that large-area graphene films synthesised by chemical vapour deposition (CVD) can be grown with relatively few defects, the required transfer process creates wrinkles and polymer residues that greatly reduce its performance in device applications. Graphene synthesised on silicon carbide (SiC) has shown outstanding mobility and has been successfully used to develop ultra-high frequency transistors; however, this fabrication method is limited due to the use of costly ultra-high vacuum (UHV) equipment that can reach temperatures over 1500 °C. Here, we show a simple and novel approach to synthesise graphene on SiC substrates that greatly reduces the temperature and vacuum requirements and allows the use of equipment commonly used in the semiconductor processing industry. In this work, we used plasma treatment followed by annealing in order to obtain large-scale graphene films from bulk SiC. After exposure to N2 plasma, the annealing process promotes the reaction of nitrogen ions with Si and the simultaneous condensation of C on the surface of SiC. Eventually, a uniform, large-scale, n-type graphene film with remarkable transport behaviour on the SiC wafer is achieved. Furthermore, graphene field effect transistors (FETs) with high carrier mobilities on SiC were also demonstrated in this study.

15.
Nanoscale ; 6(15): 8635-41, 2014 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-24882359

RESUMO

Boron and nitrogen co-doping has been shown to be an effective way to induce a band gap in graphene for electrical applications but only a few theoretical studies have been done to understand the elastic and mechanical properties of the modified graphene. Until now, no experimental assessment of the mechanical modulus of boron-nitrogen-doped graphene (BNG) has been reported in the literature. Here, we demonstrate a novel non-contact approach to determine the in-plane stiffness of BNG at low BN concentrations. The in-plane stiffness of BNG with 2 at% BN concentration was estimated to be about 309 N m(-1), which is lower than that of pristine graphene, in good agreement with some theoretical studies. Moreover, we correlated the conductivity of BNG with induced strain and found the BNG to be more sensitive than pristine graphene in response to externally applied strain. This result indicates that BNG is a more suitable material than graphene for strain sensor applications.

16.
ACS Nano ; 8(1): 275-82, 2014 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-24369717

RESUMO

We present the fabrication and characterizations of novel electrical interconnect test lines made of a Cu/graphite bishell composite with the graphite cap layer grown by electron cyclotron resonance chemical vapor deposition. Through this technique, conformal multilayer graphene can be formed on the predeposited Cu interconnects under CMOS-friendly conditions. The low-temperature (400 °C) deposition also renders the process unlimitedly scalable. The graphite layer can boost the current-carrying capacity of the composite structure to 10(8) A/cm(2), more than an order of magnitude higher than that of bare metal lines, and reduces resistivity of fine test lines by ∼10%. Raman measurements reveal that physical breakdown occurs at ∼680-720 °C. Modeling the current vs voltage curves up to breakdown shows that the maximum current density of the composites is limited by self-heating of the graphite, suggesting the strong roles of phonon scattering at high fields and highlighting the significance of a metal counterpart for enhanced thermal dissipation.

17.
Rev. Soc. Peru. Med. Interna ; 26(2): 64-67, abr.-jun. 2013. tab
Artigo em Espanhol | PERNAL | ID: pnc-15696

RESUMO

Objetivo: Determinar la frecuencia de osteoporosis (OP) en pacientes mujeres postmenopáusicas mayores de 50 años con diagnóstico de artritis reumatoide (AR) y establecer indirectamente la presencia de fractura vertebral (FV) en estas a partir de la pérdida prospectiva de estatura (PPE). Material y Métodos: Es una serie de 30 casos y retrospectivo con pacientes que cumplían los criterios de elegibilidad. La densidad mineral ósea (DMO) se midió mediante densitometría ósea en columna lumbar (L2 L4) por absorciometría dual de rayos X. La OP fue definida con un score T < -2,5. La presencia de FV se estableció con PPE>2. resultados: Se halló una frecuencia de OP en el 77% de pacientes (edad promedio de 64,3 años) con índice de masa corporal (IMC) promedio de 28,4; aquellos sin OP tuvieron un IMC promedio de 27,5. Más pacientes con OP recibían corticoterapia crónica (91% vs. 86%). El porcentaje de pacientes con PPE >2cm fue mayor en los pacientes con OP (74%) que en aquellos sin OP (57%). Las medias de velocidad de sedimentación globular (VSG) y proteína C reactiva (PCR), los pacientes con historia de fractura no vertebral previa (35%), el uso de metotrexate (MTX) (96%) y la inactividad física (74%) fueron mayores en el grupo de pacientes con OP. Conclusión: Hubo una mayor frecuencia de osteoporosis en pacientes mujeres con artritis reumatoide y mayores de 50 años, y mayor probabilidad de fractura vertebral. (AU)


Objective. To determine the frequency of osteoporosis (OP) in postmenopausal women older than 50 year-old with rheumatoid arthritis (RA), and to establish the presence of vertebral fracture (VF) using the prospective loss of height (PLH). Material and Methods. It is a retrospective series of 30 cases of patients who met the eligibility criteria. Bone mineral density (BMD) was measured by bone densitometry at the lumbar spine (L2-L4), by dual x-ray absorptiometry. OP was defined with a T score < –2,5. The presence of VF was established by a PLH > 2 cm. results. We found OP in 77% of the patients (64,3 years old) who had an average body mass index (BMI) of 28,4; those without OP had an average BMI of 27,5. A greater number of OP patients were receiving corticosteroid therapy (91% vs. 86%). The percentage of patients with PPE > 2 cm was higher in the OP group (74%) than in those without OP (57%), 5 of them had lumbar spine X ray and 2 of these show VF. Moreover ESR and CRP average level, history of previous non vertebral fracture (35%), use of methotrexate (MTX) (96%) and physical inactivity (74%) were higher in the OP group. Conclusion. There was a higher frequency of osteoporosis in postmenopausal women older than 50 years old and with rheumatoid arthritis who also had more probability to suffer vertebral fractures. (AU)


Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Artrite Reumatoide , Osteoporose , Densidade Óssea , Estudos Retrospectivos , Estudos de Casos e Controles
18.
Rev. colomb. anestesiol ; 41(1): 57-60, ene.-mar. 2013. ilus, tab
Artigo em Espanhol | LILACS, COLNAL | ID: lil-675235

RESUMO

El síndrome de hipotensión endocraneana (SHE) es una patología causada por el descenso del cerebro debido a fuga de líquido cefalorraquídeo a partir de lesiones durales diagnósticas, terapéuticas o espontáneas. Tanto la fisiopatología como el enfoque clínico y terapéutico son similares a la cefalea pospunción dural, siendo esta ultima considerada como una forma leve del SHE. Se describen 2 pacientes con cefalea ortostática y alteraciones neurológicas severas luego de anestesia epidural y espinal que fueron diagnosticados y tratados como cefalea pospunción dural, pero que por su evolución anormal debieron recibir atención adicional. El SHE constituye una complicación seria que puede llevar al deterioro clínico y a la muerte, motivo por el cual requiere de un abordaje integral sobre sus factores desencadenantes, cuadro clínico, métodos diagnósticos, fisiopatología y manejo.


The intracranial hypotension syndrome (IHS) is a disorder caused by brain descent due to a CSF leak resulting from diagnostic, therapeutic or spontaneous lesions. The pathophysiology, the clinical and the therapeutic approach are similar as in post dural puncture headache, the latter being considered a mild form of IHS. This paper describes two patients with orthostatic headache and severe neurological involvement after epidural and spinal anesthesia, diagnosed and treated as post dural puncture headache, but who required additional care because of their abnormal course. IHS is a serious complication that may result in clinical decline and death; consequently, it requires a comprehensive approach to the various triggering factors, the clinical picture, diagnostic methods, pathophysiology and management.


Assuntos
Humanos
19.
Rev. colomb. anestesiol ; 40(1): 60-66, ene.-mar. 2012. ilus
Artigo em Espanhol | LILACS, COLNAL | ID: lil-650040

RESUMO

Introducción: El recurso del fibrobroncoscopio como instrumento para la intubación traqueal es relativamente reciente en nuestro medio. Su disponibilidad es cada vez mayor y por ello los anestesiólogos deben entrenarse suficientemente en el uso de este equipo. Conocer y dominar una técnica, respetando cada uno de sus pasos, es el primer paso para la realización exitosa de un procedimiento. Objetivo: En la presente guía se describe la técnica utilizada en para la intubación con Intubaciónfibrobroncoscopio en el Hospital Universitario del Valle Evaristo García. Metodología: El artículo se basa en la revisión de la literatura, la experiencia de los autores y un foro de discusión. Resultados: Se presenta la guía para la intubación con fibrobroncoscopio en el Hospital Universitario del Valle Evaristo García. Se describe la técnica para la construcción de una máscara para la ventilación del paciente durante el procedimiento de intubación traqueal con la utilización del fibrobroncoscopio.


Introduction: The use of fiberoptic bronchoscopy as a tool for tracheal intubation is relatively new in our setting. Its availability has been increasing, and hence the need for anesthetists to receive adequate training in the use of this device. Knowledge and mastery of this technique, following all the necessary steps, is the starting point for the successful performance of a procedure. Objective: These guidelines describe the technique for intubation using the fiberoptic bronchoscope at the Evaristo García University Hospital of the Colombian Department of Valle. Methodology: This paper is based on a review of the literature, the authors' experience, and a discussion forum. Results: Presentation of the guidelines for intubation using fiber optic bronchoscope at the Evaristo García University Hospital. Description of the technique for constructing a mask for patient ventilation during tracheal intubation under fiberoptic bronchoscopy.


Assuntos
Humanos
20.
Rev. neuropsiquiatr ; 73(3): 110-117, jul.-sept. 2010. ilus
Artigo em Espanhol | LILACS | ID: lil-589506

RESUMO

Presentamos 3 casos de pacientes que necesitaron cirugía a causa de un bezoar secundario a la ingesta de cabellos y otras sustancias no nutritivas (cerdas de cepillos) en el contexto de un trastorno de control de impulsos, en el que suele haber ansiedad previa a la ingesta, la misma que disminuye con el acto de ingerir estos elementos. Se revisa el concepto de impulsos irresistibles sistemáticos, la neurobiología y tratamiento de la impulsividad, y la relación de ésta con los denominados trastornos del espectro obsesivo-compulsivo. Por último, se resalta el papel del entorno familiar y social en el desarrollo y pronóstico del cuadro clínico de las pacientes.


We present 3 cases of patients who had to undergo surgery due to a bezoar that was secondary to the ingestion of hair and other non-nutritive substances (brush bristles) in the context of an impulse-control disorder, where there is often anxiety prior to intake that decreases with the act of eating these elements. We reviewed the concept of irresistible systematic impulses, the neurobiology and treatment of impulsivity, and the relation of this syndrome with the so-called obsessive-compulsive spectrum disorders. Finally, the role of the family and the social environment are highlighted in the development and prognosis of the patientsÆ clinical syndrome.


Assuntos
Humanos , Feminino , Criança , Adolescente , Bezoares , Comportamento Impulsivo , Transtorno Obsessivo-Compulsivo
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