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1.
Proc Natl Acad Sci U S A ; 119(50): e2122494119, 2022 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-36469777

RESUMEN

Physical interfaces widely exist in nature and engineering. Although the formation of passive interfaces is well elucidated, the physical principles governing active interfaces remain largely unknown. Here, we combine simulation, theory, and cell-based experiment to investigate the evolution of an active-active interface. We adopt a biphasic framework of active nematic liquid crystals. We find that long-lived topological defects mechanically energized by activity display unanticipated dynamics nearby the interface, where defects perform "U-turns" to keep away from the interface, push the interface to develop local fingers, or penetrate the interface to enter the opposite phase, driving interfacial morphogenesis and cross-interface defect transport. We identify that the emergent interfacial morphodynamics stems from the instability of the interface and is further driven by the activity-dependent defect-interface interactions. Experiments of interacting multicellular monolayers with extensile and contractile differences in cell activity have confirmed our predictions. These findings reveal a crucial role of topological defects in active-active interfaces during, for example, boundary formation and tissue competition that underlie organogenesis and clinically relevant disorders.


Asunto(s)
Cristales Líquidos , Cristales Líquidos/química , Simulación por Computador
2.
Phys Rev Lett ; 132(13): 138401, 2024 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-38613297

RESUMEN

Chirality is an essential nature of biological systems. However, it remains obscure how the handedness at the microscale is translated into chiral morphogenesis at the tissue level. Here, we investigate three-dimensional (3D) tissue morphogenesis using an active fluid theory invoking chirality. We show that the coordination of achiral and chiral stresses, arising from microscopic interactions and energy input of individual cells, can engender the self-organization of 3D papillary and helical structures. The achiral active stress drives the nucleation of asterlike topological defects, which initiate 3D out-of-plane budding, followed by rodlike elongation. The chiral active stress excites vortexlike topological defects, which favor the tip spheroidization and twisting of the elongated rod. These results unravel the chiral morphogenesis observed in our experiments of 3D organoids generated by human embryonic stem cells.


Asunto(s)
División Celular , Humanos , Morfogénesis
3.
Chemistry ; 30(35): e202401150, 2024 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-38639722

RESUMEN

In this study, a series of H-bonded arylamide foldamers bearing benzoselenadiazole ends with solvent-responsive properties have been synthesized. In dichloromethane or dimethyl sulfoxide solvents, the molecules exhibit meniscus or linear structures, respectively, which can be attributed to the unique intramolecular hydrogen bonding behavior evidenced by 1D 1H NMR and 2D NOESY spectra. UV-vis spectroscopy experiments show that the absorption wavelength of H-bonded arylamide foldamers are significantly red-shifted due to the presence of benzoselenadiazole group. In addition, the crystal structures reveal that effective intermolecular dual Se ⋅ ⋅ ⋅ N interactions between benzoselenadiazole groups induce further assembly of the monomers. Remarkably, supramolecular linear and double helices structures are constructed under the synergistic induction of intramolecular hydrogen bonding and intermolecular chalcogen bonding. Additionally, 2D DOSY diffusion spectra and theoretical modelling based on density functional theory (DFT) are performed to explore the persistence of intermolecular Se ⋅ ⋅ ⋅ N interactions beyond the crystalline state.

4.
Soft Matter ; 18(38): 7348-7359, 2022 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-36124977

RESUMEN

Skyrmions are topologically protected vortex-like excitations that hold promise for applications such as information processing and electron manipulation. Here we combine theoretical analysis and numerical simulations to show that skyrmions can spontaneously emerge in chiral active matter without external confinements or regulation. Strikingly, these activity-driven skyrmions can either self-organize into a periodic, stable square lattice consisting of half Néel skyrmions and antiskyrmions, where the in-plane flows display an antiferromagnetic vortex array, or undergo phase separation between skyrmions with different topological numbers. We identify that the emerging skyrmion dynamics stems from the competition between the chiral and polar coherence length scales dictated by the interplay of intrinsic chirality, polarity, and elasticity in the system. Our results reveal unanticipated topological excitations, self-organization, and phase separation in non-equilibrium systems and also suggest a potential way towards engineering complicated bespoke skyrmionic structures through manipulating active matter.

5.
BMC Cardiovasc Disord ; 22(1): 575, 2022 12 30.
Artículo en Inglés | MEDLINE | ID: mdl-36581799

RESUMEN

BACKGROUNDS: Remarkable interindividual variability in clopidogrel response is observed, genetic polymorphisms in P2RY12 and its signal pathway is supposed to affect clopidogrel response in CHD patients. METHODS: 539 CHD patients treated with clopidogrel were recruited. The platelet reaction index (PRI) indicated by VASP-P level were detected in 12-24 h after clopidogrel loading dose or within 5-7 days after initiation of maintain dose clopidogrel. A total of 13 SNPs in relevant genes were genotyped in sample A (239 CHD patients). The SNPs which have significant differences in PRI will be validated in another sample (sample B, 300 CHD patients). RESULTS: CYP2C19*2 increased the risk of clopidogrel resistance significantly. When CYP2C19*2 and CYP2C19*3 were considered, CYP2C19 loss of function (LOF) alleles were associated with more obviously increased the risk of clopidogrel resistance; P2RY12 rs6809699C > A polymorphism was also associated with increased risk of clopidogrel resistance (AA vs CC: P = 0.0398). This difference still existed after stratification by CYP2C19 genotypes. It was also validated in sample B. The association was also still significant even in the case of stratification by CYP2C19 genotypes in all patients (sample A + B). CONCLUSION: Our data suggest that P2RY12 rs6809699 is associated with clopidogrel resistance in CHD patients. Meanwhile, the rs6809699 AA genotype can increase on-treatment platelet activity independent of CYP2C19 LOF polymorphisms.


Asunto(s)
Clopidogrel , Enfermedad Coronaria , Inhibidores de Agregación Plaquetaria , Receptores Purinérgicos P2Y12 , Humanos , Clopidogrel/farmacología , Enfermedad Coronaria/tratamiento farmacológico , Enfermedad Coronaria/genética , Citocromo P-450 CYP2C19/genética , Genotipo , Inhibidores de Agregación Plaquetaria/farmacología , Polimorfismo de Nucleótido Simple , Antagonistas del Receptor Purinérgico P2Y/farmacología , Receptores Purinérgicos P2Y12/genética
6.
BMC Urol ; 22(1): 2, 2022 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-35012527

RESUMEN

OBJECTIVES: To describe the influence of the socioeconomic development on worldwide age-standardized incidence and mortality rates, as well as mortality-to-incidence ratio (MIR) and 5-year net survival of urologic cancer patients in recent years. METHODS: The Human Development Index (HDI) values were obtained from the United Nations Development Programme, data on age-standardized incidence/mortality rates of prostate, bladder and kidney cancer were retrieved from the GLOBOCAN database, 5-year net survival was provided by the CONCORD-3 program. We then evaluated the association between incidence/MIR/survival and HDI, with a focus on geographic variability as well as temporal patterns during the last 6 years. RESULTS: Urologic cancer incidence rates were positively correlated with HDIs, and MIRs were negatively correlated with HDIs. Prostate cancer survival also correlated positively with HDIs, solidly confirming the interrelation among cancer indicators and socioeconomic factors. Most countries experienced incidence decline over the most recent 6 years, and a substantial reduction in MIR was observed. Survival rates of prostate cancer have simultaneously improved. CONCLUSION: Development has a prominent influence on urologic cancer outcomes. HDI values are significantly correlated with cancer incidence, MIR and survival rates. HDI values have risen along with increased incidence and improved outcomes of urologic caner in recent years.


Asunto(s)
Desarrollo Económico , Cambio Social , Neoplasias Urológicas/epidemiología , Correlación de Datos , Desarrollo Económico/tendencias , Salud Global , Humanos , Incidencia , Factores Socioeconómicos , Tasa de Supervivencia
7.
Phys Rev Lett ; 125(9): 098002, 2020 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-32915620

RESUMEN

Many biological systems display intriguing chiral patterns and dynamics. Here, we present an active nematic theory accounting for individual spin to explore the collective handedness in chiral rod-shaped aggregations. We show that coordinated individual spin and motility can engender a vortex-array pattern with chirality and drive ordering of topological defects. During this chiral process, the stationary trefoil-like defects self-organize into a periodic, hexagon-dominated polygonal network, which segregates persistently rotating cometlike defects in pairs within each polygon, leading to a translation symmetry at the global scale while a broken reflection symmetry at the local scale. Such defect ordering agrees exactly with the Voronoi tiling of two-dimensional space and the emergence of the hexagonal symmetry is deciphered in analogy with topological charge neutralization. We calculate energy barriers to the topological transition of the defect ordering and explain the existing metastable states with nonhexagonal polygons. Our findings shed light on the chiral morphodynamics in life processes and also suggest a potential route towards tuning self-organization in active materials.


Asunto(s)
Flagelos/fisiología , Modelos Biológicos , Espermatozoides/fisiología , Animales , Fenómenos Fisiológicos Bacterianos , Masculino , Movimiento/fisiología , Erizos de Mar
8.
Endocr J ; 66(7): 587-595, 2019 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-30982795

RESUMEN

Polycystic ovary syndrome (PCOS) represents a serious reproductive and endocrine condition and is associated with high incidence rates. H19 is a compelling long noncoding RNA (lncRNA) which carries out a range of biological functions. However, prior to this study, little was known as to whether there was an association between lncRNA H19 and PCOS. In the current study, we used quantitative real-time polymerase chain reaction (qRT-PCR) to determine lncRNA H19 expression levels in peripheral blood leukocytes from patients with PCOS and compared this data with that derived from normal controls. We also screened data for potential relationships between lncRNA H19 and a range of endocrine variables in PCOS. The expression of lncRNA H19 was significantly higher in cases of PCOS than in controls. Individuals exhibiting higher expression levels of lncRNA H19 were associated with a significantly higher risk of PCOS than those with lower expression levels. Moreover, lncRNA H19 expression was positively correlated with fasting plasma glucose levels; this was the case with both raw data, and after adjustment for age and BMI in the PCOS group. However, lncRNA H19 expression showed no significant correlation with total testosterone or insulin resistance in either PCOS cases or the controls. In conclusion, we demonstrate the first evidence to indicate that lncRNA H19 is associated with PCOS, suggesting that elevated lncRNA H19 levels are a risk factor for PCOS. For susceptible individuals, lncRNA H19 may represent a useful biomarker of the early stages of endocrine and metabolic disorders in PCOS.


Asunto(s)
Síndrome del Ovario Poliquístico/genética , ARN Largo no Codificante/genética , Adulto , Pueblo Asiatico/genética , Pueblo Asiatico/estadística & datos numéricos , Estudios de Casos y Controles , China/epidemiología , Femenino , Expresión Génica , Predisposición Genética a la Enfermedad , Humanos , Proyectos Piloto , Síndrome del Ovario Poliquístico/epidemiología , Datos Preliminares , Factores de Riesgo
9.
Mikrochim Acta ; 186(2): 57, 2019 01 07.
Artículo en Inglés | MEDLINE | ID: mdl-30617909

RESUMEN

Disposable syringes were used in a novel point-of-care visual test for detecting pathogenic bacteria (Escherichia coli O157:H7 and Salmonella typhimurium). Hybrid nanoflowers composed of platinum nanoparticles and concanavalin A (Pt-nanoflowers) were prepared through a one-pot reaction and were found to be viable catalase mimics. They catalyze the decomposition of hydrogen peroxide (H2O2) to generate O2. When used as labels in immunoassays, they integrate both the functions of biological recognition and signal amplification. The disposable syringe pressure readout was combined with Pt-nanoflower signal conversion and successfully applied to a visual bacteria detection scheme. Both Escherichia coli O157:H7 and Salmonella typhimurium can be quantified with detection limits of as low as 15 and 7 CFU·mL-1, respectively. Graphical abstract One-pot synthetic platinum nanoparticle (PtNP)-concanavalin A hybrid nanoflowers (Pt-nanoflowers), have been used as ideal signal labels for immunoassays and integrating both essential functions of biological recognition and signal amplification. Disposable syringes were used as a readout to detect pathogenic bacteria.


Asunto(s)
Escherichia coli O157/aislamiento & purificación , Peróxido de Hidrógeno/química , Inmunoensayo/métodos , Nanopartículas del Metal/química , Salmonella typhimurium/aislamiento & purificación , Jeringas , Animales , Anticuerpos/inmunología , Concanavalina A/química , Escherichia coli O157/química , Escherichia coli O157/inmunología , Microbiología de Alimentos/instrumentación , Microbiología de Alimentos/métodos , Inmunoensayo/instrumentación , Límite de Detección , Leche/microbiología , Platino (Metal)/química , Presión , Salmonella typhimurium/química , Salmonella typhimurium/inmunología
10.
Bioorg Med Chem Lett ; 28(23-24): 3802-3807, 2018 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-30392778

RESUMEN

Rapid, sensitive and point-of-care detection of foodborne pathogenic bacteria is essential for food safety. In this study, we found that hemin-concanavalin A hybrid nanoflowers (HCH nanoflowers), as solid mimic peroxidase, could catalyze oxidation of 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS) in the presence of H2O2 to a green-colored product. HCH nanoflowers, integrating the essential functions of both biological recognition and signal amplification, meet the requirements of signal labels for colorimetric immunoassay of bacteria. In view of the excellent peroxidase mimetic catalytic activity of HCH nanoflowers, a colorimetric biosensing platform was newly constructed and applied for sensitive detection of foodborne Escherichia coli O157:H7 (E. coli O157:H7). The corresponding detection limits was as low as 4.1 CFU/mL with wide linear ranges (101-106 CFU/mL).


Asunto(s)
Materiales Biomiméticos/química , Técnicas Biosensibles/métodos , Colorimetría/métodos , Infecciones por Escherichia coli/microbiología , Escherichia coli O157/aislamiento & purificación , Hemina/química , Nanoestructuras/química , Animales , Benzotiazoles/química , Enfermedades Transmitidas por los Alimentos/microbiología , Humanos , Peróxido de Hidrógeno/química , Inmunoensayo/métodos , Límite de Detección , Leche/microbiología , Peroxidasa/química , Ácidos Sulfónicos/química
11.
BMC Genomics ; 18(1): 24, 2017 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-28056779

RESUMEN

BACKGROUND: Soil alkalinity shows significant constraints to crop productivity; however, much less attention has been paid to analyze the effect of soil alkalinity on plant growth and development. Shanrong No. 4 (SR4) is an alkalinity tolerant bread wheat cultivar selected from an asymmetric somatic hybridization between the bread wheat cultivar Jinan 177 (JN177) and tall wheatgrass (Thinopyrum ponticum), which is a suitable material for studying alkalinity tolerant associate genes. RESULTS: The growth of SR4 plant seedlings was less inhibited than that of JN177 when exposed to alkalinity stress conditions. The root cytosolic Na+/K+ ratio in alkalinity stressed SR4 was lower than in JN177, while alkalinity stressed SR4 contained higher level of nutrient elements than in JN177. SR4 plant seedlings accumulated less malondialdehyde (MDA) and reactive oxygen species (ROS), it also showed higher activity of ROS scavenging enzymes than JN177 under alkalinity stress. The root intracellular pH decreased in both alkalinity stressed JN177 and SR4, however, it was much lower in SR4 than in JN177 under alkalinity stress. The transcriptomes of SR4 and JN177 seedlings exposed to alkalinity stress were analyzed by digital gene expression tag profiling method. Alkalinity stress conditions up- and down-regulated a large number of genes in the seedling roots that play the functions in the categories of transcription regulation, signal transduction and protein modification. CONCLUSIONS: SR4 expresses a superior tolerance to alkaline stress conditions which is due to its strong absorbing ability for nutrient ions, a strong regulating ability for intracellular and rhizosphere pH and a more active ROS scavenging ability.


Asunto(s)
Adaptación Biológica/genética , Perfilación de la Expresión Génica , Concentración de Iones de Hidrógeno , Estrés Fisiológico/genética , Transcriptoma , Triticum/genética , Raíces de Plantas/genética , Especies Reactivas de Oxígeno/metabolismo , Plantones/genética , Suelo/química
12.
J Orthop Sci ; 21(1): 24-31, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26686771

RESUMEN

OBJECTIVE: A systematic review and meta-analysis was conducted to compare the relative effectiveness of bridging external fixation and non-bridging external fixation for distal radius fractures treatment. METHOD: Relevant literature were comprehensively searched using the PubMed, Springer Link, Karger Medical and Scientific Publishers, Chinese Biomedical Database (CBM) and Chinese National Knowledge Infrastructure (CNKI) databases without any language restrictions. STATA Version 12.0 software and Comprehensive Meta-analysis 2.0 were applied. RESULTS: A total of 905 patients with distal radius fracture from six eligible cohort studies were selected for statistical analysis. Our meta-analysis results indicate that the non-bridging cases had a higher risk of pin track infection, rupture of the extensor pollicis longus and nerve injury than the bridging cases. Subgroup analysis stratified by country indicated non-bridging patients showed evidence of an increased risk of pin track infection and higher risk of rupture of the extensor pollicis longus compared with the patients treated with bridging external fixation in the UK population. The follow-up results showed flexion degree of patients treated with non-bridging external fixation was slightly better than that of patients treated with bridging external fixation (P < 0.05). CONCLUSION: There is evidence in our systematic review and meta-analysis to support that bridging external fixation can reduce the incidence of pin tract infections and nerve injury compared to non-bridging external fixation, but have no significant difference in other complications and the recovery of wrist joint function. Bridging external fixation could therefore be a better choice in patients with distal radius fractures.


Asunto(s)
Fijación de Fractura/métodos , Fracturas del Radio/cirugía , Humanos , Articulación de la Muñeca
13.
Biochem Biophys Res Commun ; 464(4): 1107-1112, 2015 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-26212439

RESUMEN

Benign prostatic hyperplasia (BPH) is emerging as one of the most common diseases seriously threatening the health of elderly men. Accumulating evidences indicate that hypoxia could induce BPH. However, the underlying mechanism of BPH induced by hypoxia is not clear. In the study, hypoxia-induced autophagy could promote cell survival and endoplasmic reticula stress (ER stress) in WPMY-1 cells. Cell viability induced by hypoxia could been decreased by autophagy inhibitors (3-methyladenine, bafilomycin A1) or siRNA interference in two autophagy genes (Beclin1, ATG5) in WPMY-1 cells. Furthermore, ER stress was present in hypoxia-treated WPMY-1 cells, while autophagy and cell survival could been inhibited by C/EBP-homologous protein siRNA (CHOP), which is an important protein of ER stress pathway. Taken together, our data support a novel model that autophagy as a cytoprotective response promotes cell survival via ER stress under hypoxia in human prostate stromal cells.


Asunto(s)
Autofagia/fisiología , Retículo Endoplásmico/fisiología , Próstata/citología , Próstata/fisiología , Estrés Fisiológico/fisiología , Células del Estroma/fisiología , Hipoxia de la Célula/fisiología , Línea Celular , Supervivencia Celular/fisiología , Humanos , Masculino , Células del Estroma/citología
14.
Chem Commun (Camb) ; 60(47): 6063-6066, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38780308

RESUMEN

In this study, a benzoselenadiazole- and pyridine-bifunctionalized hydrogen-bonded arylamide foldamer was synthesized. A co-crystallization experiment with 1,4-diiodotetrafluorobenzene showed that a new type of supramolecular double helices, which were induced by three orthogonal interactions, namely, three-center hydrogen bonding (O⋯H⋯O), I⋯N halogen bonding and Se⋯N chalcogen bonding, have been constructed in the solid state. This work presents a novel instance of multiple non-covalent interactions that work together to construct supramolecular architectures.

15.
Dalton Trans ; 52(46): 17273-17278, 2023 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-37937453

RESUMEN

The exploitation of highly active and stable catalysts for reduction of CO2 and water oxidation is one of the approaches to facilitate scalable and sustainable CO2 reduction potentially at the industrial scale. Herein, a feasible strategy to rationally build an overall CO2 + H2O electrocatalytic reaction device is the preparation and matchup of a high-performance CO2 reduction catalyst and low-cost and highly active oxygen anode catalyst. A heterostructured nanosheet, γ-NiOOH/NiCO3/Ni(HCOO)2, exhibited superior catalytic activity in the oxygen evolution reaction, and was integrated with CoPc/Fe-N-C to build an overall CO2 + H2O cell with a current density of 10 mA cm-2 at a very low cell voltage of 1.97 V, and the faradaic deficiency of CO2 to CO was maintained at greater than 90% at 1.9 V.

16.
J Phys Chem Lett ; 14(16): 3844-3852, 2023 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-37067200

RESUMEN

Cobalt phthalocyanine anchored on carbon material has attracted an enormous amount of attention due to its superior performance in electrocatalytic CO2 reduction. However, the interaction between cobalt phthalocyanine and the carbon substrate remains problematic, and the role of intrinsic carbon defects is unfortunately ignored in the anchoring of cobalt phthalocyanine on carbon. Herein, new interactions between the bridging N atoms of cobalt phthalocyanine and the edge defects of carbon have been discovered, which result in a novel model of anchoring of cobalt phthalocyanine on ketjen black carbon. Such anchored cobalt phthalocyanine has been found to be responsible for superior catalysis for electrochemical reduction of CO2 to CO with high selectivity and low overpotential.

17.
Chem Commun (Camb) ; 59(77): 11580-11583, 2023 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-37691557

RESUMEN

In this paper, two types of solid phase 2D and 3D XBOFs were selectively constructed from identical building blocks of tetraphenylmethane tetrapyridine derivative and 1,4-diiodotetrafluorobenzene by changing the crystallization solvent. This 3D XBOF is a novel hybrid supramolecular organic framework with the synergistic control of hydrogen and halogen bonds.

18.
Phys Rev E ; 105(6-1): 064607, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35854599

RESUMEN

Chirality can endow nonequilibrium active matter with unique features and functions. Here, we explore the chiral dynamics in biphasic active nematics composed of self-rotating units that continuously inject energy and angular momentum at the microscale. We show that the self-rotation of units can regularize the boundaries between two phases, rendering sinusoidal-like interfaces, which allow lateral wave propagation and are characterized by chains of ordered antiferromagnetic cross-interface flow vortices. Through the spontaneous coordination of counter-rotating units across the interfaces, topological defects excited by activity are sorted spatiotemporally, where positive defects are locally trapped at the interfaces but, unexpectedly, are transported laterally in a unidirectional rather than wavy mode, whereas inertial negative defects remain spinning in the bulks. Our findings reveal that individual chirality could be harnessed to modulate interfacial morphodynamics in active systems and suggest a potential approach toward controlling topological defects for programmable microfluidics and logic operations.

19.
Artículo en Inglés | MEDLINE | ID: mdl-35793359

RESUMEN

Phthalic acid esters (PAEs) are typical endocrine disruptors which are ubiquitous contaminants. Human exposure to PAEs is through multiple routes of which the diet is recognised as the main source of daily intake. The aim of this study was to evaluate the dietary exposure to PAEs of residents in Shenzhen (China) through a total diet study and assess the potential health risk. A total of 16 different phthalate esters in samples of 12 composite food groups were determined by GC-MS. The main dietary sources of PAE exposure among adult residents in Shenzhen were potatoes (21%), eggs (21%), meat (15%) and aquatic products (14%). The median total dietary exposure to PAEs in Shenzhen residents was 7780 ng kg-1 bw d-1, and the hazard quotients (HQ) of dimethyl phthalate (DMP), diethyl phthalate (DEP), di-isobutyl phthalate (DIBP), dibutyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP) were 0.09, 0.06, 0.07, 0.10 and 0.03, respectively. Therefore, the risks from dietary PAE exposure were low. However, with the increasing use of PAEs and their accumulation in the environment, the probability of PAEs entering the food chain is gradually increasing and, therefore, PAEs should be strictly controlled and regularly monitored.


Asunto(s)
Exposición Dietética , Ácidos Ftálicos , Adulto , China , Dibutil Ftalato , Dieta , Ésteres , Humanos , Medición de Riesgo
20.
Chin J Dent Res ; 23(3): 183-189, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32974618

RESUMEN

OBJECTIVE: To design and fabricate 3D-printed rigid constraint guides for the tooth preparation for laminate veneers and to evaluate the accuracy of guide-assisted preparation. METHODS: Twenty maxillary right central incisor resin artificial teeth were randomly divided into two equal groups and prepared for laminate veneers. Tooth preparations were performed, assisted by guides in the test group and by depth gauge burs in the control group, and both were finished by freehand operation. The typodonts were 3D scanned before preparation, after initial preparation and after final preparation. The tooth preparation depths at each step, including initial preparation depth, final preparation depth and loss of tooth tissue during polishing, were measured by 3D deviation analysis. Statistical analyses were conducted to investigate differences. RESULTS: The initial preparation depth was 0.488 mm (median, quartile 0.013 mm) in the test group and 0.521 mm (median, quartile 0.013 mm) in the control group. A statistically significant difference was found between them (P < 0.05). The final preparation depth in the test group (0.547 ± 0.029 mm) was significantly less than that in the control group (0.599 ± 0.051 mm) (P < 0.05), and closer to the predesigned value (0.5 mm). There was no statistically significant difference in the loss of tooth tissue during polishing between the test group (0.072 ± 0.023 mm) and the control group (0.089 ± 0.038 mm) (P > 0.05). CONCLUSION: In maxillary central incisors, the tooth preparation for laminate veneers could be conducted using 3D-printed rigid constraint guides, the accuracy of which is better than that of depth gauge burs.


Asunto(s)
Porcelana Dental , Coronas con Frente Estético , Incisivo , Rayos Láser , Preparación del Diente
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