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1.
J Insect Sci ; 22(6)2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36449010

RESUMO

The glucosinolates (GLs) and myrosinase defensive systems in cruciferous plants were circumvented by Plutella xylostella using glucosinolate sulfatases (PxGSSs) during pest-plant interaction. Despite identifying three duplicated GSS-encoding genes in P. xylostella, limited information regarding their spatiotemporal and induced expression is available. Here, we investigated the tissue- and stage-specific expression and induction in response to GLs of PxGSS1 and PxGSS2 (PxGSS1/2) at the protein level, which shares a high degree of similarity in protein sequences. Western blotting (WB) analysis showed that PxGSS1/2 exhibited a higher protein level in mature larvae, their guts, and gut content. A significantly high protein and transcript levels of PxGSS1/2 were also detected in the salivary glands using WB and qRT-PCR. The immunofluorescence (IF) and immunohistochemistry (IHC) results confirmed that PxGSS1/2 is widely expressed in the larval body. The IHC was more appropriate than IF when autofluorescence interference was present in collected samples. Furthermore, the content of PxGSS1/2 did not change significantly under treatments of GL mixture from Arabidopsis thaliana ecotype Col-0, or commercial ally (sinigrin), 4-(methylsulfinyl)butyl, 3-(methylsulfinyl)propyl, and indol-3-ylmethyl GLs indicating that the major GLs from leaves of A. thaliana Col-0 failed to induce the expression of proteins for both PxGSS1 and PxGSS2. Our study systemically characterized the expression properties of PxGSS1/2 at the protein level, which improves our understanding of PxGSS1/2-center adaptation in P. xylostella during long-term insect-plant interaction.


Assuntos
Glucosinolatos , Lepidópteros , Animais , Imunoglobulinas , Sequência de Aminoácidos , Larva/genética , Sulfatases
2.
Anal Chem ; 93(7): 3403-3410, 2021 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-33556238

RESUMO

Rapid, quantitative, and group-targeting detection of total benzodiazepines (BZDs) is critical to create an accurate judgement in emergent medical and forensic settings. Large-size (111) faceted Ag nanosheets decorated with small ZnO nanoparticles were designed as the prominent surface-enhanced Raman scattering substrate, which possessed advantages of specific metal facets and additional charge-transfer (CT) effect from the semiconductor. The vital and bridge role of ZnO in the CT effect was systematically studied via experimental investigations and molecular dynamics simulation, which proves the essentiality of an appropriate ZnO decoration density. Upon determining optimal Ag NS/ZnO hybrids, a calibration curve of estazolam was established with a 0.5 nM detection limit. Based on the obtained curve, group-targeting screening was achieved toward total concentrations of five BZDs (estazolam, oxazepam, alprazolam, triazolam, and lorazepam). Importantly, the total concentrations of BZDs in mice serum were accurately monitored with changing analytical time during the metabolic process, which was in agreement with the tendency measured by liquid chromatography with tandem mass spectrometry.

3.
BMC Cancer ; 20(1): 667, 2020 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-32680466

RESUMO

BACKGROUND: Lymph node metastasis in the cervical region posterior to level V (PLV) can occurs in patients with nasopharyngeal carcinoma (NPC), but the significance of lymph node metastasis in this region and the delineation of the radiotherapy target area have not been reported. We aimed to explore the distribution pattern and prognosis of metastatic lymph nodes in the PLV region in patients with NPC. METHODS: We retrospectively studied 605 cases of NPC diagnosed by pathological detection from December 2011 to November 2017. The nodal distribution at each level was assessed in accordance with the Radiation Therapy Oncology Group (RTOG) guidelines proposed in 2013. The central points of the metastatic lymph nodes of the PLV region in the patients were recreated proportionally on the CT images of a standard patient with N0 NPC in reference to the normal anatomy of the PLV area. The correlation between the PLV region and the other levels, the nodal location, and the characteristics and prognosis of the PLV region were analyzed. RESULTS: Lymph node metastasis occurred in 557 (92.06%) of 605 patients. There were 30 patients (4.95%) with lymph node metastasis in the PLV region. A total of 49 metastatic lymph nodes from the PLV region were counted, and the mean vertical distance of the central point of each lymph node from the anterior surface of the trapezius muscle was 14 mm. Linear regression correlation analysis suggested that lymph node metastasis in the PLV region was associated with ipsilateral level IVa (P = 0.018), level Va, level Vb, and level Vc lymph node metastasis (all P <  0.001). The 5-year OS, PFS, LRFS, and DMFS of 29 patients with lymph node metastasis in the PLV region were 41.6, 27.7, 89.1, and 47.3%, respectively. Multivariate analysis showed that lymph node metastasis in the PLV region was an independent prognostic factor for DMFS (P <  0.05). CONCLUSION: NPC patients with lymph node metastasis in the PLV region had a poor prognosis and a high risk of distant metastasis. We recommend that the margin of the PLV region may be a new cervical lymph node segment for NPC.


Assuntos
Metástase Linfática/diagnóstico , Carcinoma Nasofaríngeo/radioterapia , Neoplasias Nasofaríngeas/radioterapia , Recidiva Local de Neoplasia/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Intervalo Livre de Doença , Fracionamento da Dose de Radiação , Feminino , Seguimentos , Humanos , Linfonodos/diagnóstico por imagem , Linfonodos/patologia , Linfonodos/efeitos da radiação , Metástase Linfática/patologia , Metástase Linfática/radioterapia , Masculino , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/mortalidade , Carcinoma Nasofaríngeo/patologia , Neoplasias Nasofaríngeas/mortalidade , Neoplasias Nasofaríngeas/patologia , Pescoço , Estadiamento de Neoplasias , Prognóstico , Intervalo Livre de Progressão , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Estudos Retrospectivos , Taxa de Sobrevida , Tomografia Computadorizada por Raios X , Adulto Jovem
4.
Langmuir ; 36(13): 3558-3564, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32176502

RESUMO

Sharp branches of gold nanostars are critical in tuning the plasmonic properties of these nanostars and maximizing the activities in surface-enhanced Raman scattering (SERS). The interaction between the capping ligands and nanostars plays an essential role in determining the morphology of the branches on the gold nanostars. In this Article, we show that 4-mercapto benzoic acid can effectively control the morphology of branched gold nanostars, and these gold nanostars can be used for the colloidal SERS detection of probe molecules at a nanomolar concentration. We also find that the sharp branches on gold nanostars will provide extra SERS activities as compared to the ones with a rough surface. Using the method of principal component analysis, we can easily distinguish the addition of 4-mercapto pyridine molecules at a concentration of 2 nM. Our work indicated the promising applications of these gold nanostars in colloidal SERS studies for various ultrasensitive chemical analyses.

5.
Anal Chem ; 90(16): 9805-9812, 2018 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-30051706

RESUMO

Clean cabbagelike (111) faceted silver crystals were synthesized via a facile galvanic replacement reaction of [Ag(NH3)2]OH and a commercial aluminum foil, a surfactant-free formation process. The cabbagelike silver crystals consisted of interconnected nanoplates and exhibited a single-crystal structure along with preferential (111) facet oriented growth. These silver crystals showed high and reliable surface-enhanced Raman scattering (SERS) activity due to electromagnetic mechanism, and they could be easily transferred onto other rigid or flexible surfaces, making their SERS applications more versatile. Since Ag (111) with low surface energy could preferentially adsorb papaverine molecules, which was verified by molecular dynamics simulation, the cabbagelike silver crystals were further employed as a promising SERS assay for efficient sensing of papaverine, a nonnarcotic alkaloid. A linear range of 0.1-1000 µM was achieved, along with a detection limit of 10 nM and good selectivity relative to other excitability drugs. This SERS assay has successfully been used to determine the concentration of papaverine in hot pot seasonings and drugs with satisfactory recoveries and relative standard deviations.

6.
Arch Virol ; 163(3): 731-735, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29214362

RESUMO

Jasmine virus H (JaVH) is a novel virus associated with symptoms of yellow mosaic on jasmine. The JaVH genome is 3,867 nt in length with five open reading frames (ORFs) encoding a 27-kDa protein (ORF 1), an 87-kDa replicase protein (ORF 2), two centrally located movement proteins (ORF 3 and 4), and a 37-kDa capsid protein (ORF 5). Based on genomic and phylogenetic analysis, JaVH is predicted to be a member of the genus Pelarspovirus in the family Tombusviridae.


Assuntos
Genoma Viral , Jasminum/virologia , Filogenia , RNA Viral/genética , Tombusviridae/genética , Sequência de Bases , Proteínas do Capsídeo/genética , Sequenciamento de Nucleotídeos em Larga Escala , Fases de Leitura Aberta , RNA Polimerase Dependente de RNA/genética , Tombusviridae/classificação , Tombusviridae/isolamento & purificação
7.
J Virol ; 90(2): 917-29, 2016 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-26537672

RESUMO

UNLABELLED: Numerous viruses are transmitted in a persistent manner by insect vectors. Persistent viruses establish their initial infection in the midgut epithelium, from where they disseminate to the midgut visceral muscles. Although propagation of viruses in insect vectors can be controlled by the small interfering RNA (siRNA) antiviral pathway, whether the siRNA pathway can control viral dissemination from the midgut epithelium is unknown. Infection by a rice virus (Southern rice black streaked dwarf virus [SRBSDV]) of its incompetent vector (the small brown planthopper [SBPH]) is restricted to the midgut epithelium. Here, we show that the siRNA pathway is triggered by SRBSDV infection in continuously cultured cells derived from the SBPH and in the midgut of the intact insect. Knockdown of the expression of the core component Dicer-2 of the siRNA pathway by RNA interference strongly increased the ability of SRBSDV to propagate in continuously cultured SBPH cells and in the midgut epithelium, allowing viral titers in the midgut epithelium to reach the threshold (1.99 × 10(9) copies of the SRBSDV P10 gene/µg of midgut RNA) needed for viral dissemination into the SBPH midgut muscles. Our results thus represent the first elucidation of the threshold for viral dissemination from the insect midgut epithelium. Silencing of Dicer-2 further facilitated the transmission of SRBSDV into rice plants by SBPHs. Taken together, our results reveal the new finding that the siRNA pathway can control the initial infection of the insect midgut epithelium by a virus, which finally affects the competence of the virus's vector. IMPORTANCE: Many viral pathogens that cause significant global health and agricultural problems are transmitted via insect vectors. The first bottleneck in viral infection, the midgut epithelium, is a principal determinant of the ability of an insect species to transmit a virus. Southern rice black streaked dwarf virus (SRBSDV) is restricted exclusively to the midgut epithelium of an incompetent vector, the small brown planthopper (SBPH). Here, we show that silencing of the core component Dicer-2 of the small interfering RNA (siRNA) pathway increases viral titers in the midgut epithelium past the threshold (1.99 × 10(9) copies of the SRBSDV P10 gene/µg of midgut RNA) for viral dissemination into the midgut muscles and then into the salivary glands, allowing the SBPH to become a competent vector of SRBSDV. This result is the first evidence that the siRNA antiviral pathway has a direct role in the control of viral dissemination from the midgut epithelium and that it affects the competence of the virus's vector.


Assuntos
Hemípteros/virologia , RNA Interferente Pequeno/metabolismo , Reoviridae/crescimento & desenvolvimento , Reoviridae/imunologia , Animais , Células Cultivadas , Epitélio/imunologia , Epitélio/virologia , Trato Gastrointestinal/imunologia , Trato Gastrointestinal/virologia
8.
Anal Chem ; 88(19): 9381-9385, 2016 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-27610708

RESUMO

Electrochemical Raman spectroscopy is a powerful molecular level diagnostic technique for in situ investigation of adsorption and reactions on various material surfaces. However, there is still a big room to improve the optical path to meet the increasing request of higher detection sensitivity and spatial resolution. Herein, we proposed a novel electrochemical Raman setup based on a water immersion objective. It dramatically reduces mismatch of the refractive index in the light path. Consequently, significant improvement in detection sensitivity and spatial resolution has been achieved from both Zemax simulation and the experimental results. Furthermore, the thickness of electrolyte layer could be expanded to 2 mm without any influence on the signal collection. Such a thick electrolyte layer allows a much normal electrochemical response during the spectroelectrochemical investigations of the methanol oxidation.

9.
Langmuir ; 32(26): 6674-81, 2016 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-27291864

RESUMO

Gold nanostars have unique plasmonic properties that are related to the highly branched nanostructures. However, it is challenging to precisely control these branches. Here we studied the reaction kinetics on the seed-mediated growth process of gold nanostars using in situ UV-vis spectroscopy. The impact of hydroquinone ligands on the formation and evolution of active intermediates was systematically explored. In addition, we improved the classical seed-mediated method to achieve a much better control on the final morphology of gold nanostars by a sudden addition of a high concentration ligand solution. Our method can significantly advance the syntheses of gold nanostars and provide numerous opportunities to prepare nanomaterials with unique morphology and plasmonic properties.

10.
Angew Chem Int Ed Engl ; 54(25): 7308-12, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-25939998

RESUMO

Quantitative analysis is a great challenge in surface-enhanced Raman scattering (SERS). Core-molecule-shell nanoparticles with two components in the molecular layer, a framework molecule to form the shell, and a probe molecule as a Raman internal standard, were rationally designed for quantitative SERS analysis. The signal of the embedded Raman probe provides effective feedback to correct the fluctuation of samples and measuring conditions. Meanwhile, target molecules with different affinities can be adsorbed onto the shell. The quantitative analysis of target molecules over a large concentration range has been demonstrated with a linear response of the relative SERS intensity versus the surface coverage, which has not been achieved by conventional SERS methods.

11.
Angew Chem Int Ed Engl ; 53(41): 10965-9, 2014 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-25156164

RESUMO

The orientation of metal-organic supercontainer (MOSC) molecules in Langmuir films was systematically studied at the air-water interface. The acidity of the aqueous subphases plays a significant role in tuning the orientation of MOSC molecules in the Langmuir films. Furthermore, Langmuir-Blodgett films of MOSCs were prepared and the uniform multilayer structures demonstrated various surface properties, depending on their conditions of fabrication. Our use of Langmuir films provides a novel approach to access tunable assemblies of MOSC molecules in two-dimensional thin films.

12.
Sci Rep ; 14(1): 2308, 2024 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-38280907

RESUMO

The lymph node involvement in the posterior to level V (PLV) region is mainly observed in nasopharyngeal carcinoma (NPC). Recently, we have reported the distribution of metastatic lymph nodes in the PLV region and there are correlations between the neck node levels (NNL) of NPC, but what is the boundary of the PLV region and how to delineate it remains unclear, and we further to elaborate whether the bilateral level Va should be covered as intermediate-risk nodal regions (CTVn2, about 60 Gy equivalent) for all T and N categories based on these correlations. A total of 1021 consecutive NPC patients with N1-3 stage from January 2012 to December 2020 were reviewed. The lymph node metastasis level of each patient was evaluated according to the updated guidelines proposed in 2013. According to the distribution pattern of lymph node metastasis and the anatomical structure in the PLV region, the boundaries of PLV region was delineated, and whether it is appropriate to cover the bilateral level Va as CTVn2 for all the NPC patients was further discussed. The correlations of level Va with other NNL were studied using logistic regression model. The cranial boundary of PLV region is the caudal border of cricoid cartilage, the caudal boundary is the plane serratus anterior muscle begins to appear, the anterior boundary is the anterior border of trapezius, and the posterior boundary is the convergence of levator scapulae and trapezius. Laterally, the PLV region is limited by the medial edge of trapezius and medially by the lateral surface of levator scapulae. The nodal spread in level Va is based on the lymph node metastasis of level IIb in NPC. The PLV region is a missing NNL of head and neck tumors, especially in NPC. The proposed boundaries of the PLV region can provide a preliminary proposal for the further revision of NNL in head and neck tumors. It is theoretically feasible to reduce the prophylactic irradiation dose of the bilateral level Va in patients with N0 stage or with isolated metastases in level VIIa.


Assuntos
Neoplasias Nasofaríngeas , Parede Torácica , Humanos , Carcinoma Nasofaríngeo/radioterapia , Carcinoma Nasofaríngeo/patologia , Neoplasias Nasofaríngeas/radioterapia , Neoplasias Nasofaríngeas/patologia , Metástase Linfática/patologia , Estudos de Viabilidade , Redução da Medicação , Pescoço/patologia , Linfonodos/patologia , Estadiamento de Neoplasias , Estudos Retrospectivos
13.
ACS Appl Mater Interfaces ; 16(13): 16418-16426, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38501759

RESUMO

Anticounterfeiting plays an essential role in authenticating genuine documents and combating forged products. To further advance the anticounterfeiting technology, there is a strong demand to design new functional materials with unique properties that will be appropriate for making multimode complex security labels. Recently, dynamic security labels have emerged as a new type of advanced anticounterfeiting method as they can hold a much higher security level than the traditional static ones. In this work, we report that calcium zinc germanate (CZGO) clinopyroxenes doped with lead ions have several interesting optical properties, such as dynamic fluorescence, long persistent luminescence, and photochromism. We find that the concentration of lead dopants can significantly impact the reaction kinetics as well as the crystallinity and luminescence properties of CZGO phosphors. By fully utilizing these unique properties, we have successfully fabricated several security labels with multilevel information encoding and dynamic optical performance. The combination of multimode and dynamic luminescence makes these labels extremely challenging to illegally duplicate. With further optimization, this lead-doped CZGO clinopyroxene can be well-integrated into modern anticounterfeiting techniques that will generate highly secure anticounterfeiting labels to combat fake products.

14.
MedComm (2020) ; 5(8): e660, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39015555

RESUMO

Exosomes are nanoscale vesicles of cellular origin. One of the main characteristics of exosomes is their ability to carry a wide range of biomolecules from their parental cells, which are important mediators of intercellular communication and play an important role in physiological and pathological processes. Exosomes have the advantages of biocompatibility, low immunogenicity, and wide biodistribution. As researchers' understanding of exosomes has increased, various strategies have been proposed for their use in diagnosing and treating diseases. Here, we provide an overview of the biogenesis and composition of exosomes, describe the relationship between exosomes and disease progression, and focus on the use of exosomes as biomarkers for early screening, disease monitoring, and guiding therapy in refractory diseases such as tumors and neurodegenerative diseases. We also summarize the current applications of exosomes, especially engineered exosomes, for efficient drug delivery, targeted therapies, gene therapies, and immune vaccines. Finally, the current challenges and potential research directions for the clinical application of exosomes are also discussed. In conclusion, exosomes, as an emerging molecule that can be used in the diagnosis and treatment of diseases, combined with multidisciplinary innovative solutions, will play an important role in clinical applications.

15.
Int J Radiat Oncol Biol Phys ; 120(2): 422-431, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38631536

RESUMO

PURPOSE: The standard treatment schedule for unresectable stage III non-small cell lung cancer (NSCLC) is chemotherapy with concurrent radiation therapy (60 Gy delivered in 30 fractions), although moderately hypofractionated radiation therapy (Hypo-RT) has also been considered as an alternative strategy. This study aimed to compare the efficacy and toxicity of moderately Hypo-RT with helical TomoTherapy versus conventionally fractionated radiation therapy (Con-RT) in patients with unresectable stage III NSCLC receiving concurrent chemotherapy. METHODS AND MATERIALS: In this randomized, multicenter, nonblinded phase 3 clinical trial, eligible patients were randomised at a 1:1 ratio to either the Hypo-RT group (60 Gy in 20 fractions) or Con-RT group (60 Gy in 30 fractions). All patients received 2 cycles of concurrent platinum-based chemotherapy plus 2 cycles of consolidation therapy. The primary endpoint was 3-year overall survival (OS) in the intention-to-treat population. The secondary endpoints were progression-free survival and treatment-related adverse events. RESULTS: A total of 146 patients were enrolled from July 27, 2018, to November 1, 2021. The median follow-up was 46 months. The 3-year OS rates in the Hypo-RT and Con-RT groups were 58.4% and 38.4%, respectively (P = .02). The median OS from randomisation was 41 months in the Hypo-RT group and 30 months in the Con-RT group (hazard ratio, 0.61; 95% confidence interval, 0.40-0.94; P = .02). There was no significant difference in the rates of grade ≥2 treatment-related adverse events between the 2 groups. CONCLUSIONS: Moderately Hypo-RT using helical TomoTherapy may improve OS in patients with unresectable stage III NSCLC, while maintaining toxicity rates.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Quimiorradioterapia , Neoplasias Pulmonares , Hipofracionamento da Dose de Radiação , Radioterapia de Intensidade Modulada , Humanos , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/tratamento farmacológico , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Radioterapia de Intensidade Modulada/efeitos adversos , Radioterapia de Intensidade Modulada/métodos , Quimiorradioterapia/efeitos adversos , Quimiorradioterapia/métodos , Intervalo Livre de Progressão , Estadiamento de Neoplasias , Adulto , Resultado do Tratamento , Fracionamento da Dose de Radiação
16.
Langmuir ; 28(1): 923-30, 2012 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-22103248

RESUMO

Gold nanorods have great potential in a variety of applications because of their unique physical properties. In this article, we present the layer-by-layer (LbL) assembly of thin films containing positively charged gold nanorods that are covalently functionalized by cationic thiol molecules. The cationic gold nanorods are uniformly distributed in ultrathin nanocomposite LbL thin films. We studied the collective surface plasmon resonance coupling in the LbL films via UV-visible spectroscopy and evaluated their application in the surface-enhanced Raman scattering detection of rhodamine 6G probe molecules. Furthermore, we successfully manufactured freestanding nanoscale thin films containing multilayers of gold nanorods with a total thickness of less than 50 nm. The surface morphology and their optical and mechanical properties were systematically investigated, and the polycationic gold nanorods were found to play an important role in manipulating the properties of the nanocomposite thin films. Our findings reveal that such nanorods are excellent building blocks for constructing functional LbL films with tunable plasmonic behavior and robust mechanical properties.


Assuntos
Ouro/química , Nanotubos , Cátions , Espectrofotometria Ultravioleta
17.
Langmuir ; 28(40): 14433-40, 2012 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-22974488

RESUMO

The development of novel nanomaterials with well-controlled morphologies/structures to achieve excellent activities/sensitivities in surface-enhanced Raman scattering (SERS) is crucial in advancing the high-performance SERS detections of chemical and biological species. In this study, amidoxime surface-functionalized polyacrylonitrile (ASFPAN) nanofibrous membranes surface-decorated with silver nanoparticles (Ag NPs) were prepared via the technique of electrospinning followed by the method of seed-mediated electroless plating. High SERS activities/sensitivities were observed from the ASFPAN-Ag NPs nanofibrous membranes, while the density and size of Ag NPs had an important impact on the SERS activity/sensitivity. The results confirmed that the enhancement of Raman signals is due to the presence of hot spots between/among Ag NPs on the nanofiber surfaces. Electrospun nanofibrous membranes surface-decorated with Ag NPs were mechanical flexible/resilient and could be used as highly active/sensitive SERS substrates for a broad range of applications.


Assuntos
Fenômenos Mecânicos , Membranas Artificiais , Nanopartículas Metálicas/química , Nanofibras/química , Nanotecnologia/métodos , Prata/química , Análise Espectral Raman/métodos , Propriedades de Superfície
18.
Phys Chem Chem Phys ; 14(29): 10168-77, 2012 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-22724125

RESUMO

Fluorescence intensity and its ratio mapping combined with time-dependent optical microscopy and atomic force microscopy (AFM) were used to understand morphology evolution of local aggregates and neighboring regions for organic solar cells. Three solvents with different boiling points including chlorobenzene (CB), 1,3-dichlorobenzene (1,3-DCB) and 1,2-dichlorobenzene (1,2-DCB) were used to engineer morphology. These solvents affected morphology evolution factors such as solvent evaporation rate, formation (e.g., growth rate, size and/or quantity) of (6,6)-phenyl-C61-butric-acid methyl ester (PCBM)-rich aggregates, and packing/ordering of poly(3-hexylthiophene) (P3HT). Three local regions (1, 2 and 3) including microscale aggregates and their surrounding areas were identified to explore the mechanism of morphology evolution. Region 1 was the PCBM-rich aggregates; region 2 was the PCBM-deficient area; and region 3 was the area composed of a relatively normal P3HT/PCBM composite beyond region 2 for each solvent. The intensity of fluorescence spectra decreased as region 1 > region 2 > region 3 in thermally annealed (140 °C, 20 min) P3HT/PCBM blend film from each solvent. The highest fluorescence intensity in region 1 was probably caused by the relatively poor phase separation where both PCBM and P3HT formed large isolated domains. The higher fluorescence intensity ratio (720 nm/650 nm) suggested a larger relative amount of PCBM molecules, supported by similar morphologies in fluorescence intensity ratio mapping compared to those in optical images. The fluorescence intensity ratio was with the order of region 1 > region 3 > region 2 in both CB and 1,3-DCB based films, but with region 1 > region 2 > region 3 for the 1,2-DCB based film. The order of effective area taken up by aggregates was CB > 1,3-DCB > 1,2-DCB in annealed (140 °C, 10 min) bulk blend films. The final solar cell performance agreed with morphology results. This work is imperative with regards to revealing the mechanism of morphology evolution in local aggregates and surrounding regions for organic photovoltaic films.

19.
Mitochondrial DNA B Resour ; 7(6): 944-945, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35692643

RESUMO

Complete chloroplast genome (cpDNA) sequence of Fagus hayatae Palib. is yet to be reported, and the phylogenetic position of this species is still under debate. In this study, the complete cpDNA sequence of F. hayatae was determined from Illumina NovaSeq pair-end sequencing data. Results revealed that it has a sequence length of 158,360 bp and contains 131 annotated genes, which consist of 83 protein-coding genes, 40 tRNA genes, and eight rRNA genes. The phylogenetic analysis of the complete cpDNA sequence indicates that Fagus represents a monophyletic clade within Fagaceae. The species relatedness between F. hayatae and F. engleriana is relatively close.

20.
Nanotechnology ; 22(27): 275712, 2011 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-21606566

RESUMO

Silver nanowires were synthesized with a green method and characterized with microscopic and diffractometric methods. The correlation between the colors of the nanowires deposited on a solid substrate and their diameters was explored. Silver nanowires that appear similar in color in the optical micrographs have very similar diameters as determined by atomic force microscopy. We have summarized the diameter-dependent coloration for these silver nanowires. An optical interference model was applied to explain such correlation. In addition, microreflectance spectra were obtained from individual nanowires and the observed spectra can be explained with the optical interference theory. This work provides a cheap, quick and simple screening method for studying the diameter distribution of silver nanowires, as well as the diameter variations of individual silver nanowires, without complicated sample preparation.

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