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1.
BMC Psychiatry ; 21(1): 14, 2021 01 07.
Artículo en Inglés | MEDLINE | ID: mdl-33413251

RESUMEN

BACKGROUND: Tic disorders are childhood-onset neuropsychiatric disorders characterized by multiple motor or vocal tics with frequent comorbidities and a broad spectrum of phenotypic presentations. In this study, we aimed to investigate the clinical characteristics and comorbid neuropsychiatric conditions in pediatric patients with tic disorders. METHODS: We retrospectively reviewed the medical records of 119 pediatric patients (89 males, 30 females) who were diagnosed with tic disorders according to the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) at Uijeongbu St. Mary's Hospital, Republic of Korea, between January 2012 and July 2019. RESULTS: The mean age of tic onset was 6.9 years (range, 1-14) and the mean age at diagnosis was 8 years (range, 1-17). The mean lag between tic onset and diagnosis was 13.3 months (range, 0.25-132). The most common, first-presenting tics were eye blinking (50.4%), followed by jaw or lip movement (29.4%) and throat clearing (29.4%). Thirty-seven (31.1%) patients had at least one co-occurring neuropsychiatric disorder at the time of tic diagnosis. Subtypes of tic disorders, types of initial tics, and presence of neuropsychiatric comorbidities were not associated with tic severity. Tic severity was associated with greater functional impairment and tic noticeability (p < 0.05). A relatively shorter time to diagnosis was associated with tic severity (Spearman's ρ = - 0.14, p = 0.11). CONCLUSIONS: The evolving nature of tic expression and severity, high prevalence of neuropsychiatric comorbidities, and associated functional impairments emphasize the importance of comprehensive assessment during the disease course for determining and prioritizing goals of treatment.


Asunto(s)
Trastorno Obsesivo Compulsivo , Trastornos de Tic , Tics , Síndrome de Tourette , Adolescente , Niño , Preescolar , Comorbilidad , Femenino , Humanos , Lactante , Masculino , Trastorno Obsesivo Compulsivo/epidemiología , República de Corea/epidemiología , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Trastornos de Tic/epidemiología , Tics/epidemiología
2.
Angew Chem Int Ed Engl ; 59(9): 3460-3464, 2020 02 24.
Artículo en Inglés | MEDLINE | ID: mdl-31863556

RESUMEN

Hierarchical self-assembly of building blocks over multiple length scales is ubiquitous in living organisms. Microtubules are one of the principal cellular components formed by hierarchical self-assembly of nanometer-sized tubulin heterodimers into protofilaments, which then associate to form micron-length-scale, multi-stranded tubes. This peculiar biological process is now mimicked with a fully synthetic molecule, which forms a 1:1 host-guest complex with cucurbit[7]uril as a globular building block, and then polymerizes into linear poly-pseudorotaxanes that associate laterally with each other in a self-shape-complementary manner to form a tubular structure with a length over tens of micrometers. Molecular dynamic simulations suggest that the tubular assembly consists of eight poly-pseudorotaxanes that wind together to form a 4.5 nm wide multi-stranded tubule.


Asunto(s)
Microtúbulos/química , Polímeros/química , Hidrocarburos Aromáticos con Puentes/química , Imidazoles/química , Microscopía de Fuerza Atómica , Microscopía Electrónica de Transmisión , Microtúbulos/metabolismo , Simulación de Dinámica Molecular , Rotaxanos/química
3.
J Korean Med Sci ; 30(1): 88-94, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25552888

RESUMEN

Efficacy and safety of bone cement augmentations for spinal pathologic fractures related to multiple myeloma, and usefulness of radionuclide studies for surgical decision were retrospectively evaluated. Forty eight vertebrae from 27 patients for bone cement augmentation procedures and 48 vertebrae from 29 patients for conservative treatment were enrolled. Clinical results using visual analogue scale (VAS) and Oswestry disability index (ODI), and radiologic results were assessed. For clinical decisions on treatment of spinal pathologic fracture, bone scan or single photon emission computed tomography was done for 20 patients who underwent surgery. Mean follow-up was 16.8 months. In terms of clinical results, immediate pain relief was superior in the operated group to that in the conservative group. ODI, maintenance of vertebral height and local kyphotic angle at the last follow-up were superior in the operated group in comparison to the conservative group. At one year follow-up, cumulative survival rate were 77.4% and 74.7% in the operated and conservative groups, respectively (log rank test> 0.05). Leakage of bone cement was noted at 10 treated vertebrae. Bone cement augmentations presented short-term pain relief for spinal pathologic fractures by myeloma with relative safety in highly selected patients, and radionuclide imaging studies were useful for the surgical decision on these procedures.


Asunto(s)
Cementos para Huesos/uso terapéutico , Mieloma Múltiple/patología , Fracturas de la Columna Vertebral/diagnóstico por imagen , Fracturas de la Columna Vertebral/cirugía , Columna Vertebral/cirugía , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Cintigrafía , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Columna Vertebral/diagnóstico por imagen , Resultado del Tratamiento
4.
Am J Orthod Dentofacial Orthop ; 145(4 Suppl): S125-35, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24680021

RESUMEN

To reduce a large amount of mandibular setback and to prevent pharyngeal airway space narrowing when correcting a severe anteroposterior skeletal discrepancy, a mandibular step osteotomy is often combined with 2-stage orthognathic surgery. This case report describes a successful 2-stage orthognathic treatment combined with a mandibular step osteotomy. A 20-year-old man had severe mandibular protrusion, facial asymmetry, and macroglossia. Phase 1 surgery included the mandibular step osteotomy and a partial glossectomy; then we performed phase 2 surgery with a 2-piece LeFort I segmental osteotomy and a bilateral intraoral vertical ramus osteotomy to correct the patient's mandibular protrusion and facial asymmetry. The total treatment period was 30 months, and the final result was improvement of the patient's facial appearance.


Asunto(s)
Maloclusión de Angle Clase III/cirugía , Osteotomía Mandibular/métodos , Osteotomía Le Fort/métodos , Osteotomía Sagital de Rama Mandibular/métodos , Glosectomía/métodos , Humanos , Masculino , Maloclusión de Angle Clase III/diagnóstico por imagen , Radiografía , Adulto Joven
5.
J Korean Med Sci ; 28(1): 120-7, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23341722

RESUMEN

In 2009, the first outbreak of hand, foot and mouth disease (HFMD) or herpangina (HP) caused by enterovirus 71 occurred in the Republic of Korea. This study inquired into risk factors associated with complications of HFMD or HP. A retrospective medical records review was conducted on HFMD or HP patients for whom etiologic viruses had been verified in 2009. One hundred sixty-eight patients were examined for this investigation. Eighty patients were without complications while 88 were accompanied by complications, and 2 had expired. Enterovirus 71 subgenotype C4a was the most prevalent in number with 67 cases (54.9%). In the univariate analysis, the disease patterns of HFMD rather than HP, fever longer than 4 days, peak body temperature over 39℃, vomiting, headache, neurologic signs, serum glucose over 100 mg/dL, and having an enterovirus 71 as a causative virus were significant risk factors of the complications. After multiple logistic analysis, headache (Odds ratio [OR], 10.75; P < 0.001) and neurologic signs (OR, 42.76; P < 0.001) were found to be the most significant factors. Early detection and proper management of patients with aforementioned risk factors would be necessary in order to attain a better clinical outcome.


Asunto(s)
Enfermedad de Boca, Mano y Pie/complicaciones , Herpangina/complicaciones , Adolescente , Adulto , Glucemia/análisis , Temperatura Corporal , Enterovirus Humano A/genética , Enterovirus Humano A/aislamiento & purificación , Femenino , Fiebre/etiología , Genotipo , Enfermedad de Boca, Mano y Pie/virología , Cefalea/etiología , Herpangina/virología , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , República de Corea , Estudios Retrospectivos , Factores de Riesgo , Vómitos/etiología , Adulto Joven
6.
J Hazard Mater ; 459: 132045, 2023 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-37480606

RESUMEN

Synthetic plastic is used throughout daily life and industry, threatening organisms with microplastic pollution. Polystyrene is a major plastic polymer and also widely found sources of plastic wastes and microplastics. Here, we report that Enterobacter hormaechei LG3 (CP118279.1), a facultative anaerobic bacterial strain isolated from the gut of Tenebrio molitor larvae (mealworms) can oxidize and depolymerize polystyrene under anaerobic conditions. LG3 performed biodegradation while forming a biofilm on the plastic surface. PS biodegradation was characterized by analyses of surface oxidation, change in morphology and molecular weights, and production of biodegraded derivative. The biodegradation performance by LG3 was compared with PS biodegradation by Bacillus amyloliquefaciens SCGB1 under both anaerobic and aerobic conditions. In addition, through nanopore sequencing technology, we identified degradative enzymes, including thiol peroxidase (tpx), alkyl hydroperoxide reductase C (ahpC) and bacterioferritin comigratory protein (bcp). Along with the upregulation of degradative enzymes for biodegradation, changes in lipid A and biofilm-associated proteins were also observed after the cells were incubated with polystyrene microplastics. Our results provide evidence for anaerobic biodegradation by polystyrene-degrading bacteria and show alterations in gene expression patterns after polystyrene microplastics treatment in the opportunistic pathogen Enterobacter hormaechei.


Asunto(s)
Microbioma Gastrointestinal , Tenebrio , Animales , Microplásticos , Poliestirenos , Plásticos , Anaerobiosis , Enterobacter , Biodegradación Ambiental
7.
World Neurosurg ; 171: e31-e37, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36528321

RESUMEN

OBJECTIVE: We investigated the long-term effects of bone cement-augmented instrumentation in multilevel lumbar fusions in a retrospective cohort study. The use of cement-augmented screws is one of the techniques used to reduce early mechanical failure in treating multilevel lumbar fusion, especially in the elderly. However, little information is available regarding the long-term effects. METHODS: A total of 51 patients who had undergone ≥3 levels of lumbar fusion were divided into two groups according to the use of bone cement-augmented screw fixation involving the upper instrumented vertebra: 22 patients in the cement-augmented group (group I) and 29 patients in the non-cement-augmented group (group II). Analysis of radiographic adjacent disc segment degeneration (ASD) revealed patients with lumbosacral fusion with a similar degree of osteoporosis. Radiologic ASD was defined as progression of >2 UCLA (University of California, Los Angeles) grades at 2 years postoperatively. Other sagittal parameters and the preoperative magnetic resonance imaging Pfirrmann grades at the adjacent levels, possibly related to ASD, were also analyzed. RESULTS: No significant differences were present in the preoperative demographic and radiographic parameters between the 2 groups. However, the postoperative kyphotic changes at 3 months were greater for the non-cement-augmented group. In terms of the long-term effects, the incidence of radiologic ASD (group I, n = 20 [95.2%]; vs group II, n = 15 [53.6%]) was significantly higher in the cement-augmented group. Logistic regression analysis of radiologic ASD, including other clinical and radiologic parameters, postoperative pelvic incidence-lumbar lordosis mismatch (odds ratio, 5.201; 95% confidence interval, 1.123-24.090; P = 0.035), and cement augmentation (odds ratio, 20.193; 95% confidence interval, 2.195-185.729; P = 0.008) showed a significant correlation with the development of radiologic ASD at 2 years postoperatively. CONCLUSIONS: Although bone cement-augmented screw implantation can prevent kyphotic deformation at the proximal junction of upper instrumented vertebra in the early postoperative stages of multilevel lumbar fusion, a careful selection of patients is required because of possibly accelerated degeneration of adjacent segments.


Asunto(s)
Degeneración del Disco Intervertebral , Lordosis , Fusión Vertebral , Humanos , Anciano , Cementos para Huesos , Estudios Retrospectivos , Vértebras Lumbares/cirugía , Degeneración del Disco Intervertebral/cirugía , Lordosis/etiología , Fusión Vertebral/métodos
8.
J Neurosurg ; : 1-9, 2022 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-36681991

RESUMEN

OBJECTIVE: Trigeminal schwannoma is a rare CNS tumor and involves the multicompartmental skull base. Recently, the endoscopic transorbital approach (ETOA) has emerged as a technique for minimally invasive surgery. The objective of this study was to evaluate the optimal indications and clinical outcomes of the ETOA for trigeminal schwannomas based on their tumor classification. METHODS: Between September 2016 and February 2022, the ETOA was performed in 50 patients with trigeminal schwannoma at four tertiary hospitals. There were 15 men and 35 women in the study, with a mean age of 46.9 years. All tumors were classified as type A (predominantly involving the middle cranial fossa), type B (predominantly involving the posterior cranial fossa), type C (dumbbell-shaped tumors involving the middle and posterior fossa), or type D (involvement of the extracranial compartment). Type D tumors were also subclassified by ophthalmic division (D1), maxillary division (D2), and mandibular division (D3). Clinical outcome was analyzed, including extent of resection and surgical morbidities. RESULTS: In this study, overall gross-total resection (GTR) was performed in 35 (70.0%) of 50 patients and near-total resection (NTR) in 9 patients (18.0%). The mean follow-up period was 21.9 (range 1-61.7) months. There was no tumor regrowth or recurrence during the follow-up period. Based on the classification, there were 17 type A tumors, 20 type C, and 13 type D. There were no type B tumors. Of the 13 type D tumors, 7 were D1, 1 D2, and 5 D3. For type A tumors, GTR or NTR was achieved using an ETOA in 16 (94.1%) of 17 patients. Eighteen (90.0%) of 20 patients with type C tumors attained GTR or NTR. Ten (76.9%) of 13 patients with type D tumors underwent GTR. Statistical analysis showed that there was no significant difference in the extent of resection among the tumor subtypes. Surgical complications included transient partial ptosis (n = 4), permanent ptosis (n = 1), transient diplopia (n = 7), permanent diplopia (n = 1), corneal keratopathy (n = 7), difficulties in mastication (n = 5), and neuralgic pain or paresthesia (n = 14). There were no postoperative CSF leaks or enophthalmos during follow-up. CONCLUSIONS: This study showed that trigeminal schwannomas can be effectively treated with a minimally invasive ETOA in all tumor types, except those predominantly involving the posterior fossa (type B). For the extracranial compartments, D2 or D3 tumor types often require an ETOA combined with the endoscopic endonasal approach, while D1 tumor types can be treated using an ETOA alone.

9.
Lab Chip ; 10(16): 2130-8, 2010 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-20532357

RESUMEN

Most microfluidic devices developed to date for the analysis of live cells incorporate channels with relatively simple constant rectangular or semi-circular cross-sections, relying on complex channel network geometries rather than alteration of the shapes of the channels themselves for development of diverse functional fluidic controls, e.g., spatial gradients of bioactive ligands. In this study we describe a simple alternative method to create highly defined and predictable gradients of surface bound molecules. This method relies on the generation of a considerable variation in the spatial distribution of flow velocities within a channel with a triangular cross-section. The triangular shape can be easily implemented by using bulk wet etching and polydimethylsiloxane (PDMS) replica molding techniques. By analytical modeling and simulation, we predict that the deposition of the solute onto a channel boundary depends on the local flow rate values, yielding gradient spanning the whole width of the channel. This prediction was validated by direct visualization of the flow rate and fibronectin-rhodamine deposition in a fabricated microchannel. Using this experimental platform, we assessed cell migration in response to a fibronectin gradient deposited in the microchannels. We find that this gradient could induce robust haptotaxis of Chinese Hamster Ovary (CHO) cells towards the areas of higher fibronectin surface density. We propose that the described simple gradient generation method can help to avoid complexity present in many current device designs, allowing to introduce more easily other potentially useful design features.


Asunto(s)
Movimiento Celular/fisiología , Técnicas Analíticas Microfluídicas/instrumentación , Técnicas Analíticas Microfluídicas/métodos , Modelos Biológicos , Animales , Células CHO , Moléculas de Adhesión Celular/química , Cricetinae , Cricetulus , Dimetilpolisiloxanos , Fibronectinas/química , Microscopía Fluorescente , Microscopía por Video , Nylons , Rodaminas/química
10.
Biochem Biophys Res Commun ; 379(2): 324-9, 2009 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-19103165

RESUMEN

Here, we characterized released-exopolysaccharides (r-EPS) from Lactobacillus acidophilus A4 with the goal of identifying natural compounds that represses biofilm formation. In plastic 96-well microplates that contained 1.0 mg/ml of r-EPS, enterohemorrhagic Escherichia coli (EHEC) biofilms were dramatically decreased by 87% and 94% on polystyrene and polyvinyl chloride (PVC) surfaces, respectively. In the presence of r-EPS, neither their growth rate nor their autoinducer-2-like activity was affected on the EHEC O157:H7. Importantly, consistent reduction in biofilm formation was also observed when r-EPS was applied to the continuous-flow chamber models. In addition, we found that adding r-EPS significantly repressed biofilm formation by affecting genes related to curli production (crl, csgA, and csgB) and chemotaxis (cheY) in transcriptome analysis. Furthermore, these r-EPS could prevent biofilm formation by a wide range of Gram-negative and -positive pathogens. This property may lead to the development of novel food-grade adjuncts for microbial biofilm control.


Asunto(s)
Biopelículas/crecimiento & desarrollo , Infecciones por Escherichia coli/inmunología , Escherichia coli O157/fisiología , Lactobacillus acidophilus/inmunología , Polisacáridos Bacterianos/inmunología , Probióticos , Proteínas Bacterianas/genética , Línea Celular Tumoral , Quimiotaxis/genética , Escherichia coli O157/genética , Escherichia coli O157/inmunología , Perfilación de la Expresión Génica , Regulación Bacteriana de la Expresión Génica , Humanos , Poliestirenos , Cloruro de Polivinilo
11.
World Neurosurg ; 127: 249-252, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30980972

RESUMEN

BACKGROUND: As the prevalence of spinal fusion surgery has increased, reliable and safe bone graft substitutes have been developed in response. Biocompatible osteoconductive polymer (BOP) has been used as a bone graft alternative for spine surgery. We present a case of cervical myelopathy due to extrusion of BOP 23 years after surgery and discuss the pathophysiology in terms of spinal fusion. CASE DESCRIPTION: A 65-year-old man presented with a 3-month history of cervical myelopathic symptoms. Twenty-three years earlier, the patient had undergone cervical surgery for a C6-7 herniated disc with the use of BOP. Imaging studies of the cervical spine showed cord compression due to extruded BOP at C6-7. He underwent corpectomy of the C7 vertebral body and removal of the BOP for the neural decompression, combined with interbody fusion by use of an iliac bone graft and plate fixation. During the operation, crumbly fibers of the BOP were easily removed. His myelopathic symptoms improved immediately after surgery. Postoperative magnetic resonance imaging also showed successful decompression of the spinal cord. Histologically, a foreign body reaction and bony degeneration were found around the synthetic fibers of the BOP. CONCLUSIONS: Spine surgeons should recognize the pathophysiology of the BOP used for spine fusion surgery. Although BOP is not currently used for spinal surgery, patients undergoing previous surgery with the BOP can present with related complications. Revision surgery is recommended to remove the unincorporated BOP and achieve solid spine fusion.


Asunto(s)
Metilmetacrilatos , Complicaciones Posoperatorias , Povidona , Enfermedades de la Médula Espinal/etiología , Fusión Vertebral , Anciano , Médula Cervical , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/patología , Vértebras Cervicales/cirugía , Humanos , Masculino , Complicaciones Posoperatorias/cirugía , Enfermedades de la Médula Espinal/diagnóstico por imagen , Enfermedades de la Médula Espinal/patología , Enfermedades de la Médula Espinal/cirugía
12.
Jpn J Infect Dis ; 71(3): 191-196, 2018 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-29491241

RESUMEN

Community-acquired brain abscesses are still encountered in clinical practice and cause considerable complications, despite improvements in hygiene in modernized societies. This study aimed to identify potential risk factors pertaining to predisposing infections and microorganisms to facilitate the effective treatment of brain abscesses. Of 121 surgically treated patients with brain abscesses, the most frequent predisposing condition was odontogenic infections (49/121 patients, 40.5%) followed by sinusitis (14/121, 11.6%). Of 121 patients, 51 (42.1%) had no identifiable predisposing infection. Viridans group streptococci (VGS) were the most frequently identified (47%) bacteria in all patients, and anaerobes were more frequently isolated in patients with odontogenic infections (36.7%, p=0.001) than aerobes. Among the patients with no identifiable predisposing infection, the most commonly isolated pathogen was VGS (38.3%); anaerobes occurred significantly less frequently (p=0.045), and old pulmonary tuberculosis was significantly more common (p=0.001) than in the group with identified predisposing infections. There was only one case of staphylococcal infection in 121 patients. The present study indicates that VGS should be the first target for antibiotic treatment when predisposing infections are not identifiable in patients with brain abscesses. Additionally, the association of old tuberculosis with community-acquired brain abscesses is common in these patients.


Asunto(s)
Absceso Encefálico/epidemiología , Absceso Encefálico/cirugía , Infecciones Comunitarias Adquiridas/epidemiología , Infecciones Comunitarias Adquiridas/cirugía , Adulto , Anciano , Absceso Encefálico/diagnóstico , Absceso Encefálico/microbiología , Infecciones Comunitarias Adquiridas/diagnóstico , Infecciones Comunitarias Adquiridas/microbiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
13.
Arch Pharm Res ; 40(12): 1455-1463, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29159581

RESUMEN

Tolterodine, a nonselective muscarinic antagonist available only as immediate release (IR) or extended release (ER) oral formulations, is used for the treatment of overactive bladder (OAB). This study aimed to compare the efficacy and extent of dry mouth adverse effects of tolterodine transdermal patch to the oral formulation. The two formulations have been examined through the muscarinic receptor binding tests conducted in bladder and salivary gland tissues and the salivary secretion tests conducted in rats. Comparable average tolterodine blood concentration levels were obtained 3 h after oral administration of tolterodine 25 mg/kg and 12 h after transdermal application of tolterodine patch 6 mg/8 cm2. While Kd in the bladder tissue increased to a similar degree in both formulations of tolterodine, Kd in the salivary gland increased to a greater degree in the oral formulation. These results indicate that similar degree of inhibitory effects were observed in the bladder for both formulations while less inhibitory effects were observed in the salivary gland with tolterodine transdermal formulation compared to the oral formulation. For assessment of salivary secretion, tolterodine transdermal patch 6 mg/8 cm2 application resulted in significantly less inhibitory effects than oral tolterodine 25 mg/kg. Therefore, this study suggests that tolterodine transdermal patch could be a useful formulation that provides uniform and consistent inhibitory effects to effectively control OAB symptoms with reduced severity of dry mouth in comparison to the oral formulation.


Asunto(s)
Glándulas Salivales/efectos de los fármacos , Glándulas Salivales/metabolismo , Tartrato de Tolterodina/administración & dosificación , Tartrato de Tolterodina/farmacología , Parche Transdérmico , Administración Oral , Animales , Masculino , Ratas , Ratas Sprague-Dawley
14.
Korean J Orthod ; 46(3): 155-62, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-27226961

RESUMEN

OBJECTIVE: The aim of this study was to investigate whether labial tooth inclination and alveolar bone loss affect the moment per unit of force (Mt/F) in controlled tipping and consequent stresses on the periodontal ligament (PDL). METHODS: Three-dimensional models (n = 20) of maxillary central incisors were created with different labial inclinations (5°, 10°, 15°, and 20°) and different amounts of alveolar bone loss (0, 2, 4, and 6 mm). The Mt/F necessary for controlled tipping (Mt/Fcont) and the principal stresses on the PDL were calculated for each model separately in a finite element analysis. RESULTS: As labial inclination increased, Mt/Fcont and the length of the moment arm decreased. In contrast, increased alveolar bone loss caused increases in Mt/Fcont and the length of the moment arm. When Mt/F was near Mt/Fcont, increases in Mt/F caused compressive stresses to move from a predominantly labial apical region to a palatal apical position, and tensile stresses in the labial area moved from a cervical position to a mid-root position. Although controlled tipping was applied to the incisors, increases in alveolar bone loss and labial tooth inclination caused increases in maximum compressive and tensile stresses at the root apices. CONCLUSIONS: Increases in alveolar bone loss and labial tooth inclination caused increases in stresses that might cause root resorption at the root apex, despite the application of controlled tipping to the incisors.

15.
Environ Sci Pollut Res Int ; 22(11): 8451-9, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25548010

RESUMEN

Currently, there is a growing emphasis on wastewater reclamation and reuse all over the world due to restricted water resources. Among a variety of wastewater reuse technologies, the use of microfiltration membranes (MF) is one of the popular processes because it has the ability to successfully eliminate particulates and colloidal matters. However, successful fouling control is not easy because effluents from the activated sludge process still contain small particulates and colloidal matters such as extracellular polymeric substance (EPS) and soluble microbial products (SMP). On the other hand, microbubbles have advantageous properties compared to common bubbles, but there hasn't been reporting of the use of microbubbles in physical cleaning instead of aeration. Encouraging results were obtained herein through the application of microbubbles for physical cleaning. In evaluation of the cleaning efficiency, the efficiency of microbubbles was observed to be twice as high as that of aeration, except during the course of the initial 30 min. Total organic carbon (TOC) concentration of the membrane tank after treatment with microbubbles was more than twice as high as that after aeration for physical cleaning. The membrane cleaned with microbubbles also had the smoothest surface, with a roughness of 42.5 nm. In addition, microbubbles were found to effectively remove EPS and make the structure of the gel layer loose. In particular, the microbubbles had the ability to remove proteins through the effect of pyrolytic decomposition. Therefore, in FT-IR spectra of the membrane surfaces taken before and after physical cleaning, while each treatment showed similar peak positions, the peak values of the membrane treated with microbubbles were the lowest. Through various analyses, it was confirmed that microbubbles can remove foulants on the gel layer in spite of their very low shear force. This means that microbubble cleaning has full potential for use as a physical cleaning method in the wastewater reclamation process.


Asunto(s)
Filtración/instrumentación , Membranas Artificiales , Microburbujas , Eliminación de Residuos Líquidos/métodos , Aguas Residuales/química , Purificación del Agua/instrumentación , Purificación del Agua/métodos , Fluorescencia , Microscopía de Fuerza Atómica , Microscopía Electrónica de Rastreo , Nefelometría y Turbidimetría , Espectrofotometría , Espectroscopía Infrarroja por Transformada de Fourier
16.
Int J Pharm ; 251(1-2): 23-32, 2003 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-12527172

RESUMEN

Diamine-terminated poly(ethylene glycol) (ATPEG) was hydrophobically modified with long-chain fatty acids (FAs) through a coupling reaction using N,N'-dicyclohexyl carbodiimide (DCC). FA-PEG-FA conjugates have different physico-chemical properties according to the chain length of the fatty acid (FA). Synthesized FA-PEG-FA conjugate was confirmed by Fourier transform-infrared (FT-IR). Since FA-PEG-FA conjugates have the amphiphilic characteristics in aqueous solution, polymeric nanoparticles of FA-PEG-FA conjugates were prepared using a simple dialysis method in water. The results of 1H nuclear magnetic resonance (NMR) spectroscopy and fluorescent spectroscopy suggest that the FA-PEG-FA conjugate has a typical core-shell type nanoparticle structure made by a self-assembling process. From the analysis of fluorescence excitation spectra, especially, the critical micelles concentration (CMC) of this conjugate was changed unpredictably, i.e. the critical association concentration (CAC) value was decreased below a FA carbon number of 16 but, above increased a FA carbon number of 16. Transmission electron micrograph readings showed the spherical morphologies of the polymeric nanoparticles. The particle size was continuously decreased until below a FA carbon number of 20, but it was increased above a FA carbon number of 20. Clonazepam (CNZ), as a model drug, was easy to entrap into polymeric nanoparticles of the FA-PEG-FA conjugates. The drug release behavior was changed according to the FA chain length and was mainly diffusion controlled from the core portion.


Asunto(s)
Ácidos Grasos/farmacología , Nanotecnología/métodos , Polietilenglicoles/farmacología , Polímeros/farmacología , Portadores de Fármacos/química , Portadores de Fármacos/farmacología , Ácidos Grasos/química , Polietilenglicoles/química , Polímeros/química
17.
Arch Pharm Res ; 27(5): 562-9, 2004 May.
Artículo en Inglés | MEDLINE | ID: mdl-15202564

RESUMEN

Self-assembling nanospheres of hydrophobized pullulan have been developed. Pullulan acetate (PA), as hydrophobized pullulan, was synthesized by acetylation. Carboxymethylated poly(ethylene-glycol) (CMPEG) was introduced into pullulan acetate (PA) through a coupling reaction using N,N'-dicyclohexyl carbodiimide (DCC). A synthesized PA-PEG-PA (abbreviated as PEP) conjugate was confirmed by Fourier transform-infrared (FT-IR) spectroscopy. Since PEP conjugates have amphiphilic characteristics in aqueous solution, polymeric nanoparticles of PEP conjugates were prepared using a simple dialysis method in water. From the analysis of fluorescence excitation spectra primarily, the critical association concentration (CAC) of this conjugate was found to be 0.0063 g/L. Observations by scanning electron microscopy (SEM) showed the spherical morphologies of the PEP nanoparticles. The particle size distribution of the PEP conjugates was determined using photon correlation spectroscopy (PCS) and the intensity-average particle size was 193.3 +/- 13.53 nm with a unimodal distribution. Clonazepam (CNZ), as a model drug, was easy to entrap into polymeric nanoparticles of the PEP conjugates. The drug release behavior was mainly diffusion controlled from the core portion.


Asunto(s)
Portadores de Fármacos/química , Glucanos/química , Nanoestructuras/química , Polietilenglicoles/química , Portadores de Fármacos/análisis , Portadores de Fármacos/farmacocinética , Glucanos/análisis , Glucanos/farmacocinética , Nanoestructuras/análisis , Polietilenglicoles/análisis , Polietilenglicoles/farmacocinética
18.
Korean J Pediatr ; 57(7): 323-8, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25114693

RESUMEN

PURPOSE: Adenoid hypertrophy is a physical alteration that may affect speech, and a speech disorder can have other negative effects on a child's life. Airway obstruction leads to constricted oral breathing and causes postural alterations of several oro-facial structures, including the mouth, tongue, and hyoid bone. The postural modifications may affect several aspects of speech production. METHODS: In this study, we compared articulation errors in 19 children with adenoid hypertrophy (subject group) to those of 33 children with functional articulation disorders independent of anatomical problems (control group). RESULTS: The mean age of the subject group was significantly higher (P=0.016). Substitution was more frequent in the subject group (P=0.003; odds ratio [OR], 1.80; 95% confidence interval [CI], 1.23-2.62), while omission was less frequent (P<0.001; OR, 0.43; 95% CI, 0.27-0.67). Articulation errors were significantly less frequent in the palatal affricative in the subject group (P=0.047; OR, 0.25; 95% CI, 0.07-0.92). The number of articulation errors in other consonants was not different between the two groups. Nasalization and aspiration were significantly more frequent in the subject group (P=0.007 and 0.014; OR, 14.77 and 0.014; 95% CI, [1.62-135.04] and NA, respectively). Otherwise, there were no differences between the two groups. CONCLUSION: We identified the characteristics of articulation errors in children with adenoid hypertrophy, but our data did not show the relationship between adenoid hypertrophy and oral motor function that has been observed in previous studies. The association between adenoid hypertrophy and oral motor function remains doubtful.

19.
Int J Food Microbiol ; 191: 129-34, 2014 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-25261831

RESUMEN

We investigated the efficacy of sequential treatments of aqueous chlorine and chlorine dioxide and drying in killing Escherichia coli O157:H7 in biofilms formed on stainless steel, glass, plastic, and wooden surfaces. Cells attached to and formed a biofilm on wooden surfaces at significantly (P ≤ 0.05) higher levels compared with other surface types. The lethal activities of sodium hypochlorite (NaOCl) and aqueous chlorine dioxide (ClO2) against E. coli O157:H7 in a biofilm on various food-contact surfaces were compared. Chlorine dioxide generally showed greater lethal activity than NaOCl against E. coli O157:H7 in a biofilm on the same type of surface. The resistance of E. coli O157:H7 to both sanitizers increased in the order of wood>plastic>glass>stainless steel. The synergistic lethal effects of sequential ClO2 and drying treatments on E. coli O157:H7 in a biofilm on wooden surfaces were evaluated. When wooden surfaces harboring E. coli O157:H7 biofilm were treated with ClO2 (200 µg/ml, 10 min), rinsed with water, and subsequently dried at 43% relative humidity and 22 °C, the number of E. coli O157:H7 on the surface decreased by an additional 6.4 CFU/coupon within 6 h of drying. However, when the wooden surface was treated with water or NaOCl and dried under the same conditions, the pathogen decreased by only 0.4 or 1.0 log CFU/coupon, respectively, after 12 h of drying. This indicates that ClO2 treatment of food-contact surfaces results in residual lethality to E. coli O157:H7 during the drying process. These observations will be useful when selecting an appropriate type of food-contact surfaces, determining a proper sanitizer for decontamination, and designing an effective sanitization program to eliminate E. coli O157:H7 on food-contact surfaces in food processing, distribution, and preparation environments.


Asunto(s)
Biopelículas/efectos de los fármacos , Compuestos de Cloro/farmacología , Desecación , Escherichia coli O157/efectos de los fármacos , Manipulación de Alimentos/instrumentación , Microbiología de Alimentos/métodos , Viabilidad Microbiana/efectos de los fármacos , Óxidos/farmacología , Antiinfecciosos/farmacología , Recuento de Colonia Microbiana , Escherichia coli/efectos de los fármacos , Vidrio , Plásticos , Hipoclorito de Sodio/farmacología , Acero Inoxidable , Agua , Madera/microbiología
20.
ACS Nano ; 7(1): 143-53, 2013 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-23214437

RESUMEN

A robust method for preparing nanocomposite multilayers was developed to facilitate the assembly of well-defined hydrophobic nanoparticles (i.e., metal and transition metal oxide NPs) with a wide range of functionalities. The resulting multilayers were stable in both organic and aqueous media and were characterized by a high NP packing density. For example, inorganic NPs (including Ag, Au, Pd, Fe3O4, MnO2) dispersed in organic media [corrected]were shown to undergo layer-by-layer assembly with amine-functionalized polymers to form nanocomposite multilayers while incurring minimal physical and chemical degradation of the inorganic NPs. In addition, the nanocomposite multilayer films formed onto flat and colloidal substrates could directly induce the adsorption of the electrostatically charged layers without the need for additional surface treatments. This approach is applicable to the preparation of electronic film devices, such as nonvolatile memory devices requiring a high memory performance (ON/OFF current ratio >10(3) and good memory stability).


Asunto(s)
Equipos de Almacenamiento de Computador , Compuestos Inorgánicos/química , Membranas Artificiales , Nanoestructuras/química , Nanoestructuras/ultraestructura , Diseño de Equipo , Análisis de Falla de Equipo , Interacciones Hidrofóbicas e Hidrofílicas , Ligandos , Ensayo de Materiales , Tamaño de la Partícula
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