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Oxychalcogenides are increasingly attracting wide attention because they contain multiple anions that may combine the advantages of oxides and chalcogenides. In this work, two new pentanary oxythiogermanates, Ba3MGe3O2S8 [M = Ca (1), Zn (2)], were synthesized by a high-temperature solid-state reaction. They crystallize in the orthorhombic space group Pnma, and their structures contain isolated [Ge3O2S8]8- units constructed by one [GeO2S2] and two [GeOS3] tetrahedra that link with M2+ ions to build the {[MGe3O2S8]6-}∞ chain, representing a new type of oxythiogermanate. Notably, a [ZnS5] square pyramid exists in 2. Their structural chemistry and relationship with relevant structures are analyzed. 1 and 2 exhibit wide band gaps of 3.93 and 2.63 eV, birefringences of 0.100 and 0.089 at 2100 nm, respectively, and also obvious photocurrent responses. This work may be extended to a family of AE3MIIMIV3O2Q8 (AE = alkali-earth metal; MII = Ca, Zn, Cd, Hg; MIV = Si, Ge, Sn; Q = S, Se), and further systematic survey on them can be performed to enrich the study of multifunctional oxychalcogenides.
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Oxygen vacancies can change the physical and chemical properties of oxide semiconductors, which is applied to the field of ph otocatalysis, including water splitting, carbon dioxide reduction, and organic synthesis. However, the mechanism of oxygen vacancies in photocatalytic organic synthesis is still unclear. Herein, oxygen vacancies constructed on spinel CuFe2O4 nanoparticles were found to trigger the photocatalytic synthesis of an unsaturated amide with high conversion and selectivity. Such superior performance was attributed to the fact that the enriched surface oxygen vacancies could increase the charge separation efficiency and optimize the reaction path, which has been demonstrated both experimentally and theoretically.
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The development of fluorescent probe for hydrazine (N2H4) detection has attracted much attention due to the important role of N2H4 plays in the fields of medicine, agriculture, biology and environments. In this paper, the optical properties and water solubility of two novel two-photon fluorescent molecular probes (Probe1 and Probe2) before and after the reaction with N2H4 are studied by using the density function theory. The results show that electronic distribution and transition dipole moment of the probes are obviously changed after the reaction with N2H4, thus the optical properties of the molecules are influenced and the detection of N2H4 are realized. In addition, photoinduced electron transfer processes for Probe1 and Probe2 in the presence of N2H4 are theoretically characterized, which explains the experimental observations from the microscopic mechanism. Special attention has been paid on the analysis of the two-photon absorption for the probes with the absence and presence of N2H4 by the response theory method. Both probes with good water solubility show large variation on the two-photon absorption cross section when reacts with N2H4. In particular, the two-photon absorption response of Probe2 is more obvious, so it possesses preferable two-photon fluorescence microscopic imaging ability. More importantly, the receptor effect on the sensing performances of the probes are demonstrated, providing a theoretical reference for the design and synthesis on more efficient two-photon fluorescence N2H4 probes. Our study provides necessary information on the response mechanism of the studied chemosensors and helps to establish the relationship between the structure and optical properties of two-photon fluorescence N2H4 probes.
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BACKGROUND: Maxillary hypoplasia is common in patients with cleft lip and palate. In this study, the authors investigated the soft tissue changes in midfacial regions after anterior maxillary segmental distraction osteogenesis (AMSDO) in patients with cleft. METHODS: Eight patients with cleft lip and palate who underwent AMSDO were enrolled in this study. Spiral computed tomographic images were taken before surgery and 6-12 months after surgery to evaluate soft tissue changes after AMSDO. The midfacial area was divided into 6 regions of interest according to anatomical subunits. The average movements of each region were calculated using volumetric changes and preoperative region surface areas. RESULTS: The upper lip on both sides has the most anterior movement (5.22±0.86 and 5.14±0.84 mm), supracommissural regions have a little less movement (4.11±0.55 and 3.81±0.67 mm), paranasal regions have the least movement (3.37±0.47 and 3.15±0.36 mm). The corresponding regions of interest showed no significant difference on the cleft side versus the noncleft side. CONCLUSIONS: Anterior maxillary segmental distraction osteogenesis can improve the soft tissue profile in patients with cleft, and there was no significant difference in soft tissue changes between the cleft side and the noncleft side.
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Fenda Labial , Fissura Palatina , Osteogênese por Distração , Humanos , Fenda Labial/cirurgia , Fissura Palatina/cirurgia , Osteogênese por Distração/métodos , Resultado do Tratamento , Maxila/cirurgia , Osteotomia de Le Fort/métodos , CefalometriaRESUMO
PURPOSE: This study proposes a high-precision surgical technique that combines both computer-aided design/computer-aided manufacturing (CAD/CAM) and the screw-track transfer technique for condylar and occlusal reconstruction. MATERIALS AND METHODS: A 43-year-old male patient with facial asymmetry, limited mouth opening, and malocclusion underwent condylar and occlusal reconstruction surgery. An autogenous cor-onoid process graft was performed by combining CAD/CAM and the screw-track transfer technique. RESULTS: The surgical plan was transformed successfully from preoperative virtual surgical planning to actual surgery; this was confirmed by merging the postoperative computed tomography images with the preoperative three-dimensional surgical design. The patient recovered well and had better occlusion and facial symmetry, as well as an increased degree of mouth opening post-surgery. No complications were observed. CONCLUSIONS: CAD/CAM combined with the screw-track transfer technique is a precise and feasible method that can be applied to autogenous coronoid process grafts. This approach can be used to reconstruct the condylar process and achieve a good occlusal relationship.
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Desenho Assistido por Computador , Cirurgia Assistida por Computador , Adulto , Computadores , Oclusão Dentária , Assimetria Facial/cirurgia , Humanos , Masculino , Osteotomia , Cirurgia Assistida por Computador/métodosRESUMO
PURPOSE: This study aimed to introduce an innovative method for mandibular condylectomy. A customized three-dimensional (3D) printed template is used to perform precise condylectomy in an intraoral approach. METHODS: Condylectomy combined with orthognathic surgery was used for the treatment of facial asymmetry secondary to unilateral condylar hyperplasia. The customized 3D printed osteotomy guide was placed with an intraoral approach under endoscopy, in order to perform a precise condylectomy. RESULT: With the customized 3D printed template, the condylectomy was performed more precisely, and the conventional extraoral incision was avoided. The osteotomy line was accurately transferred from the virtual surgical plan to the real surgery, which assured the precise resection. CONCLUSIONS: The intraoral approach combined with a 3D printed template provides a novel solution to perform the condylectomy precisely.
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Má Oclusão , Procedimentos Cirúrgicos Ortognáticos , Assimetria Facial/diagnóstico por imagem , Assimetria Facial/patologia , Assimetria Facial/cirurgia , Humanos , Hiperplasia/patologia , Hiperplasia/cirurgia , Má Oclusão/patologia , Côndilo Mandibular/diagnóstico por imagem , Côndilo Mandibular/patologia , Côndilo Mandibular/cirurgia , Procedimentos Cirúrgicos Ortognáticos/métodosRESUMO
While multiple bond metathesis reactions, for example olefin metathesis, have seen considerable recent progress, direct metathesis of traditionally inert C-O single bonds is extremely rare and particularly challenging. Undoubtedly, metathesis reaction of C-O bonds is one of the most ideal routes for the value-added upgrading of molecules involving C-O bonds. Reported here is a new protocol to achieve the formal C-O/O-H cross-metathesis via alternating current electrolysis. Featuring mild reaction conditions, the protocol allows readily available 4-alkoxy anilines and alcohols to be converted into a wide range of valuable products in highly regioselective and chemoselective manner. Moreover, the present strategy can be used in the late-stage modification of pharmaceuticals as well as biologically active compounds, which demonstrated the potential application.
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Álcoois , Compostos de Anilina , Álcoois/química , Alcenos/química , EletróliseRESUMO
This in situ transmission electron microscopy work presents a nanoscale characterization of the microstructural evolution in 3D-printed Inconel 718 (IN718) while exposed to elevated temperature and an associated change in the mechanical property under tensile loading. Here, we utilized a specially designed specimen shape that enables tensile testing of nano-sized thin films without off-plane deformations. Additionally, it allows a seamless transition from the in situ heating to tensile experiment using the same specimen, which enables a direct correlation of the microstructure and the mechanical property of the sample. The method was successfully used to observe the residual stress relaxation and the formation of incoherent γ' precipitates when temperature was increased to 700°C. The subsequent in situ tensile test revealed that the exposure of the as-printed IN718 to a high temperature without full heat treatment (solutionizing and double aging) leads to loss of ductility.
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PURPOSE: Pruzansky-Kaban III hemifacial microsomia (HFM) is a rare congenital facial deformity, and it is challenging to reconstruct the facial appearance. The aim of the present study was to describe a technique of application of virtual planning for three-dimensional (3D) guided maxillofacial reconstruction of Pruzansky-Kaban III HFM using custom made fixation plate. METHODS: With the help of 3D models, a preoperative virtual planning and surgical simulation were performed. Computer-aided design/computer-aided manufacture (CAD/CAM) patient customized guides and custom fixation plates were designed to reconstruct the maxillofacial skull intraoperatively. Assessment was achieved through evaluation of the postoperative effects, such as imaging, facial appearance recovery and operation time. RESULTS: Five patients with Pruzansky-Kaban III HFM were enrolled into this study. The results showed an exceptional accuracy between the preoperative virtual planning and the outcomes actually achieved postoperatively. Intraoperative measurements were no longer needed and the different surgical steps became more simple and easier. The total time was distributed as: 160 minutes for the surgical time, 40 minutes for preoperative virtual plan, and 80 minutes for designing the patient specific cutting guides and custom fixation plates. The operating time and tissue damage were reduced. All cases underwent uneventful healing without any complications. CONCLUSION: The technique of patient specific guides and custom fixation plates is a reliable method of conveying the virtual plan to the operative field with higher efficiency in patients with Pruzansky-Kaban III HFM.
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Síndrome de Goldenhar , Procedimentos Cirúrgicos Ortognáticos , Cirurgia Assistida por Computador , Placas Ósseas , Desenho Assistido por Computador , Síndrome de Goldenhar/diagnóstico por imagem , Síndrome de Goldenhar/cirurgia , Humanos , Imageamento TridimensionalRESUMO
Novel Eu8In17.33S34 (1) is obtained by a solid state reaction and its structure features three parallel slabs of [In9.33S18]∞, [Eu8]∞, and [In8S16]∞, together with defects in specific lattice sites. It is the first monoclinic ternary M8- mIn18- n Q34 ( M = Pb, Sn, Eu; Q = S, Se) phase member, and the modulation from the ultralong In-S bond and lattice site with strong antibonding effect results in the unique structure feature. Its single crystals show anisotropic conductivity and photoconductivity.
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The physical properties of doped multifunctional compounds are commonly tuned by controlling the amount of dopants, but this control is limited because all the properties are influenced simultaneously by this single parameter. Here, we present a strategy that enables the fine-tuning of a specific combination of properties by controlling the reduction of dopants. The feasibility of this approach was demonstrated by optimizing the near-IR photoluminescence of strontium titanate SrTiO3 :Ni for potential applications in biomedicine for a range of absorbance in the visible/near-IR region. We discussed how material properties, such as luminescence, conductivity, or photocatalytic properties can be designed by carefully controlling the ratio of dopants in different oxidation states.
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An original concept for the property tuning of semiconductors is demonstrated by the synthesis of a p-type zinc oxide (ZnO)-like metal-organic framework (MOF), (ZnC2O3H2)n, which can be regarded as a possible alternative for ZnO, a natural n-type semiconductor. When small oxygen-rich organic linkers are introduced to the Zn-O system, oxygen vacancies and a deep valence-band maximum, the two obstacles for generating p-type behavior in ZnO, are restrained and raised, respectively. Further studies of this material on the doping and photoluminescence behaviors confirm its resemblance to metal oxides (MOs). This result answers the challenges of generating p-type behavior in an n-type-like system. This concept reveals that a new category of hybrid materials, with an embedded continuous metal-oxygen network, lies between the MOs and MOFs. It provides concrete support for the development of p-type hybrid semiconductors in the near future and, more importantly, the enrichment of tuning possibilities in inorganic semiconductors.
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Nickel carbodiimide (NiCN2) was synthesized using a two-step precipitation-decomposition route leading to a brown powder with gypsum-flower-like morphology and a large specific surface area (75 m2/g). This layered material crystallizes in the 2H structure type of delafossite (space group P63/mmc), which is built upon infinite 2/∞[NiN2] layers connected by linear carbodiimide ([NâCâN]2-) bridges. An X-ray diffraction Rietveld refinement and thermal analyses pointed out some nickel deficiencies in the material, and band structure calculations carried out on the defect compound predicted p-type conductivity in relation to a slight amount of N2-. This p-type conductivity was demonstrated by electrochemical impedance spectroscopy measurements, and a flat band potential of 0.90 V vs SCE at pH 9.4 was measured. This value, which is more positive than those of CuGaO2 and CuCrO2 delafossite oxides and NiO, prompted us to test NiCN2 nanoparticles as a photocathode in p-type dye-sensitized solar cells.
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Optical and electrical characteristics of solid materials are well-known to be intimately related to the presence of intrinsic or extrinsic defects. Hence, the control of defects in semiconductors is of great importance to achieve specific properties, for example, transparency and conductivity. Herein, a facile and controllable reduction method for modulating the defects is proposed and used for the case of p-type delafossite CuCrO2 nanoparticles. The optical absorption in the infrared region of the CuCrO2 material can then be fine-tuned via the continuous reduction of nonstoichiometric Cu(II), naturally stabilized in small amounts. This reduction modifies the concentration of positive charge carriers in the material, and thus the conductive and reflective properties, as well as the flat band potential. Indeed, this controllable reduction methodology provides a novel strategy to modulate the (opto-) electronic characteristics of semiconductors.
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Agar is a polysaccharide extracted from the cell walls of some macro-algaes. Among the reported agarases, most of them come from marine environment. In order to better understand different sources of agarases, it is important to search new non-marine native ones. In this study, seven agar-degrading bacteria were first isolated from the tissues of plants, belonging to three genera, i.e., Paenibacillus sp., Pseudomonas sp., and Klebsiella sp. Among them, the genus Klebsiella was first reported to have agarolytic ability and the genus Pseudomonas was first isolated from non-marine environment with agarase activity. Besides, seven strains were characterized by investigating the growth and agarase production in the presence of various polysaccharides. The results showed that they could grow on several polysaccharides such as araban, carrageenan, chitin, starch, and xylan. Besides, they could also produce agarase in the presence of different polysaccharides other than agar. Extracellular agarases from seven strains were further analyzed by SDS-PAGE combined with activity staining and estimated to be 75 kDa which has great difference from most reported agarases.
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Ágar/metabolismo , Bactérias/classificação , Bactérias/metabolismo , Endófitos/classificação , Endófitos/metabolismo , Plantas/microbiologia , Bactérias/genética , Bactérias/isolamento & purificação , Endófitos/genética , Endófitos/isolamento & purificação , Glicosídeo Hidrolases/metabolismo , Dados de Sequência Molecular , Filogenia , Polissacarídeos/metabolismo , RNA Ribossômico 16SRESUMO
Ni-doped CdS nanowires were synthesized by a simple one-step method. X-ray diffraction, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy confirmed that light Ni doping can form shallow surface states due to the presence of substitutional Ni ions, and heavy Ni doping can form deep surface states due to the presence of interstitial Ni ions. Surface photovoltage spectroscopy and transient photovoltage measurements revealed that the shallow surface states can prolong the lifetime of the photogenerated charge carriers, whereas the deep surface states lead to recombination of the photogenerated charge carriers. The relationship between different surface states and the photocatalytic performance of CdS nanocrystals are discussed. The enhanced density of shallow surface states due to light Ni doping significantly promotes photocatalytic H2 production.
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A series of novel 4-substituted-2-{[(1H-benzo[d]imidazol-2-yl)methyl] thio}-6-methylpyrimidine derivatives were designed, synthesized and evaluated for their cytotoxic activities against four human cancer cell lines and inhibitory activities against five type culture strains in vitro. Some of synthetic pyrimidine-benzimidazol combinations showed good inhibitory activities against Stenotrophomonas maltophilia, especially compounds 7b and 7c. Compounds 7a and 7d exhibited enhanced activities against MGC-803 in vitro, when compared to 5-Fu.
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Benzimidazóis/síntese química , Benzimidazóis/farmacologia , Pirimidinas/síntese química , Pirimidinas/farmacologia , Anti-Infecciosos/síntese química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Benzimidazóis/química , Candida albicans/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Química Combinatória , Humanos , Concentração Inibidora 50 , Testes de Sensibilidade Microbiana , Estrutura Molecular , Pirimidinas/químicaRESUMO
As important quantitative traits, the growth rate and backfat thickness are controlled by multiple genes. The aim of this investigation was to evaluate the effect of the single and multiple SNPs of four candidate genes (IGF2, JHDM1A, COPB1 and TEF-1) on growth rate and backfat thickness. The four candidate genes were mapped on the p arm of SSC 2, and there are several QTLs, such as average daily gain, backfat thickness, an imprinted QTLs affecting muscle mass and fat deposition have been reported in this region. The polymorphisms of these genes were detected using PCR-RFLP methods, mixed procedure was used to analyze the single marker association with the growth and backfat thickness traits, and the gene-gene combination was investigated using multiple-markers analysis. The single marker association analysis indicated that the IGF2 intron-3 g.3072G > A and the substitution g.93G > A of TEF-1 gene were significantly associated with the age at 100 kg (P < 0.05). The JHDM1A 3'UTR g.224C > G, the c.3096C > T polymorphism of COPB1 gene and the substitution g.93G > A of TEF-1 gene were all significantly associated with the backfat at the shoulder (P < 0.05), backfat at the last rib, backfat at the lumbar, and the average backfat thickness, respectively. The multiple-markers analysis indicated that IGF2 and TEF-1 integrated gene networks for the age at 100 kg. Therefore, we can suggest that the polymorphism of IGF2 and TEF-1 gene could be used in marker-assisted selection for the age at 100 kg in Large White pigs.
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Proteína Coatomer/genética , Fator de Crescimento Insulin-Like II/genética , Histona Desmetilases com o Domínio Jumonji/genética , Polimorfismo de Nucleotídeo Único , Sus scrofa/genética , Fatores de Transcrição/genética , Adiposidade/genética , Animais , Dorso/crescimento & desenvolvimento , Peso Corporal , Cromossomos de Mamíferos/genética , Frequência do Gene , Estudos de Associação Genética , Marcadores Genéticos , Locos de Características Quantitativas , Gordura Subcutânea/crescimento & desenvolvimento , Sus scrofa/crescimento & desenvolvimentoRESUMO
Bi-doped Sn-Ag-Cu (SAC) microelectronic solder is gaining attention for its utility as a material for solder joints that connect substrates to printed circuit boards (PCB) in future advanced packages, as Bi-doped SAC is reported to have a lower melting temperature, higher strength, higher wettability on conducting pads, and lower intermetallic compound (IMC) formation at the solder-pad interface. As solder joints are subjected to aging during their service life, an investigation of aging-induced changes in the microstructure and mechanical properties of the solder alloy is needed before its wider acceptance in advanced packages. This study focuses on the effects of 1 to 3 wt.% Bi doping in an Sn-3.0Ag-0.5Cu (SAC305) solder alloy on aging-induced changes in hardness and creep resistance for samples prepared by high cooling rates (>5 °C/s). The specimens were aged at ambient and elevated temperatures for up to 90 days and subjected to quasistatic nanoindentation to determine hardness and nanoscale dynamic nanoindentation to determine creep behavior. The microstructural evolution was investigated with a scanning electron microscope in tandem with energy-dispersive spectroscopy to correlate with aging-induced property changes. The hardness and creep strength of the samples were found to increase as the Bi content increased. Moreover, the hardness and creep strength of the 0-1 wt.% Bi-doped SAC305 was significantly reduced with aging, while that of the 2-3 wt.% Bi-doped SAC305 increased with aging. The changes in these properties with aging were correlated to the interplay of multiple hardening and softening mechanisms. In particular, for 2-3 wt.% Bi, the enhanced performance was attributed to the potential formation of additional Ag3Sn IMCs with aging due to non-equilibrium solidification and the more uniform distribution of Bi precipitates. The observations that 2-3 wt.% Bi enhances the hardness and creep strength of the SAC305 alloy with isothermal aging to mitigate reliability risks is relevant for solder samples prepared using high cooling rates.
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The self-assembled carbon nitride quantum dots (CNQDs) has been largely advanced owing to the structure-relative photocatalytic activities, especially its electronic structure, which can be regulated by defects, functional groups, and doping. However, there are still issues such as wide band gaps for the assembles and severe recombination of photoinduced charges. Herein, we demonstrate the self-assembly of CNQDs into fusiform hollow superstructures (CNFHs), induced by hydrogen bonding between the terminal functional groups (-OH, -COOH, and -NH2). During the top-down assembly process, the hydrogen bonding dominates and initiates lateral cross-linking between adjacent CNQDs, which further twist into fusiform hollow structures. Benefitted greatly from the ultrathin and hollow nature of the superstructure that provides more exposed active sites, coupled with the introduction of phosphorus doping atoms into the framework induced narrowed band gap, CNFHs exhibits an 18-fold higher activity than the bulk counterpart toward photocatalytic hydrogen evolution after loading the CoP co-catalyst. This work presents a new platform to design and manipulate carbon nitride superstructures.