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1.
Environ Sci Technol ; 56(7): 4121-4131, 2022 04 05.
Artículo en Inglés | MEDLINE | ID: mdl-35312300

RESUMEN

This study conducted saturated column experiments to systematically investigate deposition of 1 µm positively charged polystyrene latex micro-colloids (representing microplastic particles) on negatively charged rough sand, glass beads, and soil with pore water velocities (PWV) from 4.9 × 10-5 to 8.8 × 10-4 m/s. A critical value of PWV was found below which colloidal attachment efficiency (AE) increased with increasing PWV. The increase in AE with PWV was attributed to enhanced delivery of the colloids and subsequent attachment at concave locations of rough collector surfaces. The AE decreased with further increasing PWV beyond the threshold because the convex sites became unavailable for colloid attachment. By simulating the rough surfaces using the Weierstrass-Mandelbrot equation, the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) interaction energy calculations and torque analysis revealed that the adhesive torques could be reduced to be comparable or smaller than hydrodynamic torques even under the favorable conditions. Interestingly, scanning electron microscopic experiments showed that blocking occurred at convex sites at all ionic strengths (ISs) (e.g., even when the colloid-colloid interaction was attractive), whereas at concave sites, blocking and ripening (i.e., attached colloids favor subsequent attachment) occurred at low and high ISs, respectively. To our knowledge, our work was the first to show coexistence of blocking and ripening at high ISs due to variation of the collector surface morphology.


Asunto(s)
Coloides , Plásticos , Concentración Osmolar , Porosidad , Agua
2.
Environ Res ; 204(Pt C): 112177, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-34717945

RESUMEN

Reverse thermally induced separation (RTIPS) was used to obtain a separation membrane with a better internal structure for a higher water flux and a surface that could easily form a hydration layer. In comparison to the traditional modification method, this work focused on the aspect that the internal structure obtained by changing the membrane-making method provided easier adhesion conditions for the dopamine/TiO2 hybrid nanoparticles (DA/TiO2 HNPs) obtained by biomimetic mineralization. It provided a basis for exploring the variation in adhesion with the water bath temperature and the amount of titanium added through the study of turbidity point, SEM images, water contact angle, thermogravimetric test, EDX, AFM, XPS, FTIR and other test results. The SEM images proved that the membrane obtained through the RTIPS method had a porous surface and spongy internal structure, furthermore, additional polymers were adsorbed. Use of EDX demonstrated that biomimetic mineralization prevented the production of agglomerated titanium dioxide. XPS and FTIR spectra confirmed the introduction and immobilization of HNP aggregation. Moreover, a decrease in the surface roughness and water contact angle further suggested an improvement in the hydrophilicity of the modified membrane. The introduction of HNP at a higher water bath temperature helped increase the water flux up to ten times, moreover, the oil-water separation efficiency could still reach over 99.50%. Lastly, a cycle test of the modified membrane under the optimal conditions helped confirm that the membrane forming conditions at this time could provide a better environment for the formation of the hydrophilic layer, which was conducive to the recycling of the separation membrane. In summary, more fixed more hydrophilic particles could be obtained through the RTIPS method based on biomimetic mineralization to prevent the accumulation of titanium dioxide, thus helping improve permeability and anti-fouling of the membrane.


Asunto(s)
Biónica , Membranas Artificiales , Polímeros/química , Sulfonas
3.
Proc Natl Acad Sci U S A ; 116(20): 9820-9824, 2019 05 14.
Artículo en Inglés | MEDLINE | ID: mdl-31036653

RESUMEN

Middle to Late Pleistocene human evolution in East Asia has remained controversial regarding the extent of morphological continuity through archaic humans and to modern humans. Newly found ∼300,000-y-old human remains from Hualongdong (HLD), China, including a largely complete skull (HLD 6), share East Asian Middle Pleistocene (MPl) human traits of a low vault with a frontal keel (but no parietal sagittal keel or angular torus), a low and wide nasal aperture, a pronounced supraorbital torus (especially medially), a nonlevel nasal floor, and small or absent third molars. It lacks a malar incisure but has a large superior medial pterygoid tubercle. HLD 6 also exhibits a relatively flat superior face, a more vertical mandibular symphysis, a pronounced mental trigone, and simple occlusal morphology, foreshadowing modern human morphology. The HLD human fossils thus variably resemble other later MPl East Asian remains, but add to the overall variation in the sample. Their configurations, with those of other Middle and early Late Pleistocene East Asian remains, support archaic human regional continuity and provide a background to the subsequent archaic-to-modern human transition in the region.


Asunto(s)
Fósiles , Cráneo , China , Humanos , Diente
4.
Ecotoxicol Environ Saf ; 241: 113742, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35679726

RESUMEN

The application of plastic mulch films brings convenience to agricultural production, but also causes plastic waste that can be degraded into microplastics (MPs). However, little is known about the fate of plastic waste in agricultural ecosystem under freeze-thaw alternation in middle and high latitudes, as well as in highlands around the world. Whether the release of plasticizers, i.e. phthalate esters (PAEs), under such conditions would pose a potential risk to exposed organisms due to bioaccumulation is also unknown. To fill these data gaps, the agricultural fields in Liaoning of China with typical freeze-thaw alternation was selected as the study area. The transformation of plastic film was demonstrated by simulation freeze-thaw alternating from -30 to 20 â„ƒ. Soil samples were collected to investigate the patterns of MP composition, abundance, and distribution. Concurrently, the concentrations of two PAEs including bis(2-ethylhexyl) phthalate (DEHP) and diethyl phthalate (DEP) in soils were analyzed to provide information on the correlation between MPs abundance and PAEs concentrations as well as potential risks. The results showed that freeze-thaw alternating can accelerate the formation of MPs and release of PAEs from plastic waste. The abundance of MPs was positively correlated with the concentration of PAEs. Soil PAEs ranged from 3268 ± 213-6351 ± 110 µg/kg, indicating that over 40 % of the PAEs were transferred from plastic films to soils. Such residual amounts could pose risk for exposed organisms. Hence, the current study suggested that special concerns should be given to the release plasticizers in plastic waste of agricultural soils.


Asunto(s)
Ácidos Ftálicos , Contaminantes del Suelo , China , Dibutil Ftalato , Ecosistema , Ésteres , Plastificantes/análisis , Plásticos , Suelo , Contaminantes del Suelo/análisis
5.
Environ Res ; 196: 110964, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33675799

RESUMEN

In this study, to mitigate the permeability-selectivity trade-off effect, Pluronic F127 (F127) and HKUST-1 were employed to construct high-performance membranes based on the reverse thermally induced phase separation (RTIPS) method. F127, as a hydrophilic modifier, was applied to increase permeability and resist polyethersulfone (PES) membrane fouling, while the collapse of HKSUT-1 caused by its instability in pure water improved the permeability and selectivity of the membrane. Characterizations demonstrated the successful synthesis of HKUST-1, together with the successful introduction of HKSUT-1 and F127 in PES membranes. It was observed that the membrane prepared by the RTIPS process possessed a uniformly porous surface and sponge-like cross-section with excellent mechanical properties, higher permeability, and selectivity compared to the dense skin and finger-like cross-section of the membrane prepared by the nonsolvent induced phase separation (NIPS) method. Moreover, the permeation and bovine serum albumin (BSA) rejection rate of the optimal membrane reached 2378 L/m2 h and 89.3%, respectively, which were far higher than those of the pure membrane. Hydrophilic F127 and many microvoids formed by the collapse of HKUST-1, played an important role in excellent antifouling properties, high permeability, and selectivity by pure water flux (PWF), flux recovery rate (FRR), BSA flux, and COD removal rate tests. Overall, the membrane with F127 and HKSUT-1 prepared via the RTIPS method not only obtained excellent antifouling properties but also mitigated the permeability-selectivity trade-off.


Asunto(s)
Membranas Artificiales , Estructuras Metalorgánicas , Permeabilidad , Polietilenos , Polímeros , Polipropilenos , Sulfonas
6.
Huan Jing Ke Xue ; 44(3): 1244-1257, 2023 Mar 08.
Artículo en Zh | MEDLINE | ID: mdl-36922186

RESUMEN

As an emerging pollutant of global concern, microplastics (plastics with size<5 mm) and heavy metals are widely found in freshwater environments. Microplastics migrate easily, are difficult to degrade, and have large specific surface areas. They can enrich a variety of pollutants such as heavy metals and greatly increase their potential harm to the environment and ecology. Firstly, the special environmental behavior of microplastics carrying heavy metals and migrating together in freshwater environments was defined as the "Trojan-horse effect." Then, the Trojan-horse effect and its mechanism of microplastics and heavy metals in the freshwater environment were summarized and expounded from four aspects:the source and distribution of microplastics in the freshwater environment, the enrichment effect of microplastics on heavy metals, the impact of microplastics and the heavy metal Trojan-horse effect on its migration behavior, and the biological impact of microplastics and the heavy metal Trojan-horse effect. The results showed that, as a wide range of non-point source pollutants, microplastics widely existed in freshwater environments. In freshwater environments, the adsorption degree of single metals was different in different environments. It was mainly affected by microplastics, metals, and environmental factors. There was competitive adsorption in the presence of multiple metal ions. The Trojan-horse effect of microplastics and heavy metals could also affect their co-transport behavior. The Trojan-horse effect of microplastics and heavy metals in the freshwater environment frequently exacerbated their toxicity to aquatic organisms. This study provides references for comprehensively understanding the Trojan-horse effect and its mechanism in microplastics and heavy metals in the freshwater environment, which could effectively reduce the ecological risk and impact on human health of microplastics and heavy metals in the freshwater environment.


Asunto(s)
Contaminantes Ambientales , Metales Pesados , Contaminantes Químicos del Agua , Humanos , Microplásticos , Plásticos , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente , Agua Dulce
7.
Int J Biol Macromol ; 246: 125687, 2023 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-37406902

RESUMEN

To develop a greener and more efficient method for producing cellulose nanofibers (CNFs) from raw plants, an AlCl3-enhanced ternary deep eutectic solvent, DES2 (consisting of choline chloride, citric acid, and AlCl3·6H2O in a molar ratio of 1:0.4:0.08), was synthesized. Raw elephant grass (EG) was pretreated with DES2, followed by sodium chlorite (NaClO2) bleaching and ultrasonic disruption to extract high-performance CNFs. The DES2 and NaClO2 treatments effectively removed hemicellulose and lignin, achieving removal rates of 99.23 % and 99.62 %, respectively, while maintaining a cellulose content of 78.3 %. DES2 demonstrated easy recyclability and maintained excellent biomass pretreatment performance even after multiple cycles. Following a brief 30-min intermittent ultrasound treatment, the resulting CNFs demonstrated superior crystallinity, increased carboxyl content, and a narrower width distribution compared to CNFs obtained from AlCl3-free DES1. Optimized conditions at 110 °C yielded CNFs with 85.3 % crystallinity, 0.64 mmol/g carboxyl content, 5.15 nm width distribution, and excellent dispersion in water for at least six months. Additionally, CNFs enhanced the tensile strength of chia seed mucilage (CM) composite films, showing a significant improvement to 26.6 MPa, representing a 231.3 % increase over the control film. This study offers a promising approach for efficiently producing CNFs from raw plants.


Asunto(s)
Celulosa , Nanofibras , Solventes , Cloruro de Aluminio , Disolventes Eutécticos Profundos
8.
J Colloid Interface Sci ; 613: 368-375, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35042034

RESUMEN

Improving conductivity and optimizing interface contact are two primary targets to promote the development of solid-state electrolytes. Herein, maleic acid (MA) is introduced into normal PVDF-LLZTO(Li6.75La3Zr1.75Ta0.25O12) based composite polymer-ceramic electrolytes (CPEs). Benefiting the self-polymerization of MA, a core-shell structure is spontaneously formed with LLZTO as core and MA nano-film as shell, the MA shell builds a bridge to link LLZTO and PVDF. In addition, carboxyl groups in MA provide extra channels for Li+ transmission. As a proof, the optimized 25MA-75PVDF-LLZTO CPEs demonstrates an enhanced conductivity as high as 1.15 × 10-3 S cm-1 at 30 °C, an extended electrochemical window up to < 5.0 V, a raised Li+ transfer number of 0.596, and an improved compatibility with Li metal anode. The as-prepared Li‖25MA-75PVDF-LLZTO CPEs‖LiFePO4 full cell delivers an initial specific discharge capacity of 170.5 mAh g-1 at 0.2C, a high rate capability up to 1.0C with 138 mAh g-1 and an excellent long-term cycling stability of over 180cycles without capacity attenuation. The work provides a new strategy to optimize solid state lithium batteries by introducing unsaturated small organic molecules.


Asunto(s)
Electrólitos , Polímeros de Fluorocarbono , Maleatos , Polivinilos
9.
Water Res ; 222: 118877, 2022 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-35872518

RESUMEN

The presence of heavy metals alters the colloidal stability and deposition of nanoplastics (NPs) in urban waters. Such processes are important to assess the mobility and fate of NPs and their associated heavy metals. Up to date, few studies have reported the impact of heavy metals on the colloidal behaviors of NPs and the involved mechanisms. In the study, time-resolved dynamic light scattering (DLS) and quartz crystal microbalance with dissipation (QCM-D) methods were used to assess the aggregation and deposition kinetics of polystyrene nanospheres with divalent heavy metals. For comparison, carboxyl-modified polystyrene nanospheres were used. Results reveal that heavy metals destabilized NPs more significantly than calcium ions. Spectroscopy and transmission electron microscopy analysis propose that heavy metals destabilized NPs via inner-sphere coordination with carboxyl groups and cation-π interactions, further leading to the formation of different dimensional aggregates. QCM-D results suggest that the deposition rate, irreversibility, and film compactness of NPs on silica surfaces first increased but further decreased as heavy metal concentration increased. Such deposition behaviors depended on the bridging effects between NPs and silica and aggregation-induced diffusion limitation. In that case, the destabilization and retention ability of heavy metals for NPs were related to their electronegativity and hydration shell thickness. In urban waters, the presence of natural organic matter (NOM) decreased the destabilization and retention ability of heavy metals, whereas heavy metals with environmentally relevant concentrations still enhanced the aggregation and deposition of NPs compared with other environmental cations. This study highlights the impact of heavy metal property on the colloidal behaviors of NPs, thus deepening our understanding of the mobility and fate of NPs associated with heavy metals in urban waters.


Asunto(s)
Metales Pesados , Poliestirenos , Cationes , Cinética , Microplásticos , Poliestirenos/química , Dióxido de Silicio , Agua/química
10.
Bioresour Technol ; 266: 51-59, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29957290

RESUMEN

Membrane fouling mitigation was observed during the development of novel sponge membrane bioreactor coupled with fiber bundle anoxic bio-filter (AF-MBMBR). Soluble microbial product (SMP) was found to be positively correlated with membrane fouling. To further clarify the mechanism of fouling mitigation, the effects of bio-carriers (sponge and fiber bundles) on characteristics and fouling potential of SMP were investigated. Characterization of SMP implied that as a consequence of employing bio-carriers, tyrosine and tryptophan in SMP significantly decreased, instead relative proportions of humic and fulvic acids increased. Meanwhile, batch filtration tests demonstrated that fouling potential of SMP was significantly alleviated, flux decline caused by filtrating SMP decreased from 84.5% to 60.1%. Further analysis on foulants and filtrate revealed that proteins performed high adhesion propensity on membrane while humic and fulvic acids mainly can pass through the membrane; this finding could well explain the mitigation of SMP fouling potential induced by bio-carriers.


Asunto(s)
Reactores Biológicos , Aguas Residuales , Carbohidratos , Filtración , Membranas Artificiales
11.
Zhonghua Yan Ke Za Zhi ; 40(12): 800-3, 2004 Dec.
Artículo en Zh | MEDLINE | ID: mdl-15733429

RESUMEN

OBJECTIVE: To explore the surgical approaches to obtain good aesthetic and functional results in the management of orbital and periorbital fibrous dysplasia and related deformities. METHODS: Ten cases of orbital and periorbital fibrous dysplasia were treated surgically. The location, extension and shape of the lesions were identified based on X-ray examination and two and three dimensions CT examinations preoperatively. According to the type of the lesion, different approaches were used to excise the lesion and to reconstruct the orbit. The lesions were radically or partially excised through bicoronal, intraoral and subciliary approach; the orbit was reconstructed with autogenous outer or inner table of calvarium, outer table of mandible, Medpor and prefabricated individual titanic implants. RESULTS: In 10 cases treated surgically, radical excision was employed in 4 cases and partial excision in 6 cases. Autogenous inner table of calvarium was used in 2 cases, Medpor in 2 cases, outer table of mandible in 1 case, and titanic meshwork and prefabricated individual titanic implants in 4 cases to reconstruct the orbit. After the treatment, all patients obtained satisfactory aesthetic and functional results. CONCLUSIONS: Carefully planed surgical approaches with methods for preventing the complications can be used for the treatment of orbital and periorbital fibrous dysplasia and obtaining satisfactory aesthetic and functional results.


Asunto(s)
Displasia Fibrosa Ósea/cirugía , Órbita/cirugía , Enfermedades Orbitales/cirugía , Adolescente , Adulto , Niño , Femenino , Displasia Fibrosa Ósea/diagnóstico por imagen , Humanos , Masculino , Enfermedades Orbitales/diagnóstico por imagen , Radiografía , Procedimientos de Cirugía Plástica/métodos
12.
Biomaterials ; 35(37): 9789-9801, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25239039

RESUMEN

Acrylic bone cement has been an essential non-metallic implant used as fixing agent in the cemented total joint arthroplasty (THA). However, the currently available materials based mainly on polymethylmethacrylate (PMMA) still encounter certain limitations, such as time-consuming polymerization, thermal and chemical necrosis and troublesome revision procedure. Here from an alternative way, we proposed for the first time to adopt the injectable alloy cement to address such tough issues through introducing its unique liquid-solid phase transition mechanism. A typical cement along this way is thus made of an alloy Bi/In/Sn/Zn with a specifically designed low melting point 57.5 °C, which enables its rapid molding into various desired shapes with high plasticity and ultimate metallic behaviors. The fundamental characteristics including the mechanical strength, biocompatibility and phase transition-induced thermal effects have been clarified to demonstrate the importance of such alloy as unconventional cement with favorable merits. In addition, we also disclosed its advantage as an excellent contrast agent for radiation imaging on the bone interior structure which is highly beneficial for guiding the surgery and monitoring the therapeutic effects. Particularly, the proposed alloy cement with reversible phase transition feature significantly simplifies the revision of the cement and prosthesis. This study opens the way for employing the injectable alloy materials as reversible bone cement to fulfill diverse clinical needs in the coming time.


Asunto(s)
Aleaciones/química , Bismuto/química , Cementos para Huesos/química , Indio/química , Transición de Fase , Estaño/química , Zinc/química , Aleaciones/administración & dosificación , Animales , Células 3T3 BALB , Bismuto/administración & dosificación , Línea Celular , Indio/administración & dosificación , Inyecciones , Ensayo de Materiales , Ratones , Ratones Endogámicos BALB C , Osteoblastos/citología , Osteoblastos/efectos de los fármacos , Prótesis e Implantes , Temperatura , Estaño/administración & dosificación , Zinc/administración & dosificación
13.
Nan Fang Yi Ke Da Xue Xue Bao ; 29(2): 209-12, 2009 Feb.
Artículo en Zh | MEDLINE | ID: mdl-19246280

RESUMEN

OBJECTIVE: To prepare a porcine aortic valve (PAV) free of the cellular components. METHODS: The cellular components of porcine PAV were completely removed using trypsin and Triton X-100, and the acellular PAV was examined microscopically with HE staining with its physical and chemical properties assessed. Transmission electron microscopy was used to observe the integrity of the collagen and elastin and the DNA contents in the PAV was detected to confirm the total removal of the cellular components. With the fresh PAV as the control, small pieces of the acellular PAV were implanted into the subcutaneous tissues of 4 rabbits, and 4 weeks after the implantation, the implants were harvested for microscopic observation. RESULTS: The cellular components were effectively removed from the cusps and roots of the PAV by trypsin and TritonX-100, with marked soluble protein loss [(0.24-/+0.04)% vs (0.48-/+0.12)%] and significantly increased water content [(92.2-/+1.5)% vs (89.2-/+1.6)%]. The acellular PAV still maintained good fibrous scaffold structure and the shrinkage temperature and tension at fracture underwent no significantly changes [(67.9-/+1.0) degrees celsius; vs (68.8-/+0.8) degrees celsius; and (489.3-/+19.0) g/mm2 vs (540.7-/+19.5) g/mm2, respectively]. The PAVs implanted in rabbits showed only mild tissue reaction with a few infiltrating neutrophils, lymphocytes and plasmocytes observed 4 weeks later. The accelular PAV caused obviously milder inflammatory reactions than fresh PAV. CONCLUSIONS: The acellular PAV prepared by treatment with trypsin and Triton X-100 retains good fibrous scaffold structure and mechanical strength with low antigenicity.


Asunto(s)
Válvula Aórtica , Bioprótesis , Separación Celular/métodos , Ingeniería de Tejidos/métodos , Andamios del Tejido , Animales , Válvula Aórtica/citología , Válvula Aórtica/trasplante , Octoxinol , Diseño de Prótesis , Conejos , Porcinos , Trasplante Heterólogo
14.
Zhonghua Zheng Xing Wai Ke Za Zhi ; 23(6): 467-9, 2007 Nov.
Artículo en Zh | MEDLINE | ID: mdl-18269016

RESUMEN

OBJECTIVE: To investigate a technique for correction of severe microgenia. METHODS: The mandibular symphysis was exposed through intraoral mucous incision. Two parallel osteotomies were performed under mental foramen. The mobilized segments were advanced like two steps and fixed rigidly with miniplate. RESULTS: From June, 2004 to Dec, 2005, 10 cases with severe microgenia were treated with this technique. The duration of follow-up was six months. The mean chin advancement was 1.1 cm and the mean chin vertical increase was 0.7 cm. All the patients healed very well with satisfactory aesthetic result. CONCLUSIONS: With this two-step genioplasty, the chin can be moved to ideal position with a natural appearance. It is a reliable method for severe microgenia.


Asunto(s)
Mentón/anomalías , Mentón/cirugía , Mandíbula/cirugía , Osteotomía , Adulto , Femenino , Humanos , Mandíbula/anomalías , Adulto Joven
15.
Zhonghua Zheng Xing Wai Ke Za Zhi ; 22(1): 18-21, 2006 Jan.
Artículo en Zh | MEDLINE | ID: mdl-16573158

RESUMEN

OBJECTIVE: To investigate the causes and the prophylactic for the complications following mandibular distraction osteogenesis using internal distractors. METHODS: From 1997 to 2004, a total of 46 patients (61 sides) suffering from malformations or defects of mandible who underwent mandibular distraction osteogenesis were analyzed. The diseases included hemifacial microsomia in 27 cases, congenital or acquired mandibular hypoplasia and micrognathia bilateral in 8 cases and unilateral in 4 cases, electronical injury or postoperative mandibular defects in 3 cases, Treacher Collins syndrome in 2 cases, obstructive sleep apnea syndrome in 2 cases. RESULTS: Of them, 9 patients had postoperative complications, which included 3 patients had complications associated with distractors, local infection occurred in 2 cases, apertognathia of anterior teeth in 2 case, 2 patients had sinus of the skin of the lower lip. 9 patients had been aggressivly managed and obtained satisfactory results. CONCLUSIONS: The pivotal points to reduce complications are to understand the mechanism of mandibular distraction osteogenesis completely, and to be familiar with the anatomy of mandible and adjacent tissues. It is necessary to treat with it preoperatively and postoperatively.


Asunto(s)
Fijadores Internos , Mandíbula/cirugía , Osteogénesis por Distracción/efectos adversos , Osteogénesis por Distracción/métodos , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Complicaciones Intraoperatorias/prevención & control , Masculino , Mandíbula/anomalías , Osteogénesis por Distracción/instrumentación , Complicaciones Posoperatorias/prevención & control , Adulto Joven
16.
Artículo en Inglés | MEDLINE | ID: mdl-16685904

RESUMEN

A Computer Aided Dental X-rays Analysis (CADXA) framework is proposed to semi-automatically detect areas of bone loss and root decay in digital dental X-rays. In this framework, first, a new proposed competitive coupled level set method is proposed to segment the image into three pathologically meaningful regions using two coupled level set functions. Tailored for the dental clinical environment, the segmentation stage uses a trained support vector machine (SVM) classifier to provide initial contours. Then, based on the segmentation results, an analysis scheme is applied. First, the scheme builds an uncertainty map from which those areas with bone loss will be automatically detected. Secondly, the scheme employs a method based on the SVM and the average intensity profile to isolate the teeth and detect root decay. Experimental results show that our proposed framework is able to automatically detect the areas of bone loss and, when given the orientation of the teeth, it is able to automatically detect the root decay with a seriousness level marked for diagnosis.


Asunto(s)
Algoritmos , Inteligencia Artificial , Caries Dental/diagnóstico por imagen , Almacenamiento y Recuperación de la Información/métodos , Reconocimiento de Normas Patrones Automatizadas/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Radiografía Dental Digital/métodos , Análisis por Conglomerados , Humanos , Intensificación de Imagen Radiográfica/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
17.
Zhonghua Zheng Xing Wai Ke Za Zhi ; 19(4): 267-9, 2003 Jul.
Artículo en Zh | MEDLINE | ID: mdl-14628414

RESUMEN

OBJECTIVE: To study the surgical reconstruction of secondary fracture deformities of the nasal-orbital ethmoid area. METHODS: Typical bicoronal and subciliary incisions or the adjacent scar incision were employed to expose the fractured area. The flattened nasal bone was narrowed by curved osteotomy along the medial orbital rims and trimed with a bur. 2-3 pieces of cranial outer table were used to reconstruct the nasal framework, which were fixed to the frontal bone with mini-plates. After the medial orbital wall and orbital floor were exposed, the herniated orbital contents were released and reduced to the orbital cavity. The fractured orbital walls were repaired precisely with autogenous cranial outer table or Medpor. The medial canthal tendons were anchored superior-posteriorly to the lacrimal fossa with transnasal wires. RESULTS: From December 1996 to December 2001, 34 cases of severe nasal-orbital ethmoid fracture deformities were repaired with this technique. Of them, 12 cases had combined orbital-zygomatic fracture, 4 cases had fontal sinus fracture, 1 case had Le Fort II and 1 case had Le Fort III fracture. All the patients recovered well and their facial appearance improved greatly. CONCLUSIONS: The key points for surgical reconstruction of the periorbital post-fracture deformities are narrowing the flattened nasal root by curved osteotomy, the nasal framework reconstruction with autogenous bone graft, the orbital wall repair to correct enophthalmos, and most importantly, the medial canthal tendon reduction and canthal plasty.


Asunto(s)
Hueso Etmoides/lesiones , Hueso Nasal/lesiones , Fracturas Orbitales/cirugía , Fracturas Craneales/cirugía , Adolescente , Trasplante Óseo/métodos , Cicatriz/cirugía , Enoftalmia/cirugía , Humanos , Deformidades Adquiridas Nasales/cirugía , Órbita/cirugía , Osteotomía/métodos , Senos Paranasales/lesiones , Senos Paranasales/cirugía , Polietilenos , Procedimientos de Cirugía Plástica , Fracturas Craneales/etiología , Tendones/cirugía
18.
Zhonghua Zheng Xing Wai Ke Za Zhi ; 20(2): 104-5, 2004 Mar.
Artículo en Zh | MEDLINE | ID: mdl-15334929

RESUMEN

OBJECTIVE: To explore a new method for mentoplasty. METHODS: The bilateral prominent mandibular angle or outer lamina was resected through the intraoral approach. The resected bone fragments were shaped and rigid fixed to the chin with miniplates and screws. RESULTS: A total of 30 patients (28 females, 2 males) accepted chin augmentation with this method. The mandibular angle bone was used in 20 cases and the mandibular outer lamina was used in 10 cases. The operative results were satisfactory, and the patient's facial contour was improved substantially. CONCLUSION: No rejection reaction was found after this procedure. Chin augmentation with autogenous mandibular bone is an ideal method for genioplasty.


Asunto(s)
Trasplante Óseo/métodos , Mentón/cirugía , Mandíbula/cirugía , Procedimientos de Cirugía Plástica/métodos , Adulto , Femenino , Humanos , Masculino , Trasplante Autólogo , Resultado del Tratamiento
19.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 22(3): 201-3, 2004 Jun.
Artículo en Zh | MEDLINE | ID: mdl-15293463

RESUMEN

OBJECTIVE: To investigate the treatment of square face with compositive methods. METHODS A total of 71 patients with square-shape face were treated. According to the different face skeleton and desire of patient, mandible angle curved-osteotomy and mentoplasty were used as main methods and zygomatoplasty, buccal fat pad resecting and other aesthetic methods as assistant methods to recontour the whole face skeleton. RESULTS: The face skeleton of all patients was improved with satisfaction. The following-up period was 6 months to 2 years. In this patients group, massive haemorrhage was occurred during operation in one patient, mental nerve of of one side was injured in two patients, the lip mucosa was wounded in five patients. CONCLUSION: Mandible angle curve-osteotomy and mentoplasty combined with other assistant aesthetic operations were ideal methods to recontour square face. The result was satisfactory.


Asunto(s)
Mejilla/cirugía , Mandíbula/cirugía , Osteotomía , Adolescente , Adulto , Femenino , Estudios de Seguimiento , Humanos , Masculino , Cirugía Plástica , Resultado del Tratamiento
20.
Zhonghua Zheng Xing Wai Ke Za Zhi ; 20(3): 209-11, 2004 May.
Artículo en Zh | MEDLINE | ID: mdl-15449624

RESUMEN

OBJECTIVE: To study the applications of bone grafts from the cranium or mandible in the repair of posttraumatic deformities of the nose. METHODS: From 1997 to 2002, a total of 44 patients, who presented with secondary nose deformity as well as facial fractures, were reconstructed by autogeneous outer table grafts of the calvarial or mandibular bone after facial skeleton reposition. In this series, 32 cases used the calvarial bone, 12 cases used the mandible bone, which was harvested through a coronal incision and an oral approach respectively. RESULTS: The surgical incisions healed primarily in all patients with minimal scar. The facial appearance was greatly improved. No implant infection, extrusion and shift were observed in the postoperative follow-up of 6 months to 2 years. There was not obvious bone resorption, nor donor site morbidity. CONCLUSION: Autogeneous calvarial and mandibular bone was an ideal material of bone graft in reconstruction of severe posttraumatic deformities of the nose. Compared with other autogeneous and alloplastic materials, the outer table of the calvarial and mandibular bone produced less morbidity of the donor site, invisible scar, no rejection and less resorption.


Asunto(s)
Traumatismos Faciales/cirugía , Implantación de Prótesis Mandibular/métodos , Procedimientos de Cirugía Plástica/métodos , Adolescente , Adulto , Traumatismos Faciales/complicaciones , Femenino , Humanos , Masculino , Mandíbula/diagnóstico por imagen , Mandíbula/cirugía , Traumatismos Mandibulares/complicaciones , Traumatismos Mandibulares/cirugía , Persona de Mediana Edad , Nariz/lesiones , Satisfacción del Paciente , Radiografía , Cráneo/cirugía , Resultado del Tratamiento
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