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1.
Front Plant Sci ; 15: 1310346, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38444537

RESUMO

Wolfberry, also known as goji berry or Lycium barbarum, is a highly valued fruit with significant health benefits and nutritional value. For more efficient and comprehensive usage of published L. barbarum genomic data, we established the Wolfberry database. The utility of the Wolfberry Genome Database (WGDB) is highlighted through the Genome browser, which enables the user to explore the L. barbarum genome, browse specific chromosomes, and access gene sequences. Gene annotation features provide comprehensive information about gene functions, locations, expression profiles, pathway involvement, protein domains, and regulatory transcription factors. The transcriptome feature allows the user to explore gene expression patterns using transcripts per kilobase million (TPM) and fragments per kilobase per million mapped reads (FPKM) metrics. The Metabolism pathway page provides insights into metabolic pathways and the involvement of the selected genes. In addition to the database content, we also introduce six analysis tools developed for the WGDB. These tools offer functionalities for gene function prediction, nucleotide and amino acid BLAST analysis, protein domain analysis, GO annotation, and gene expression pattern analysis. The WGDB is freely accessible at https://cosbi7.ee.ncku.edu.tw/Wolfberry/. Overall, WGDB serves as a valuable resource for researchers interested in the genomics and transcriptomics of L. barbarum. Its user-friendly web interface and comprehensive data facilitate the exploration of gene functions, regulatory mechanisms, and metabolic pathways, ultimately contributing to a deeper understanding of wolfberry and its potential applications in agronomy and nutrition.

2.
Sensors (Basel) ; 24(1)2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38203125

RESUMO

For ultrasound multi-angle plane wave (PW) imaging, the coherent PW compounding (CPWC) method provides limited image quality because of its conventional delay-and-sum beamforming. The delay-multiply-and-sum (DMAS) method is a coherence-based algorithm that improves image quality by introducing signal coherence among either receiving channels or PW transmit angles into the image output. The degree of signal coherence in DMAS is conventionally a global value for the entire image and thus the image resolution and contrast in the target region improves at the cost of speckle quality in the background region. In this study, the adaptive DMAS (ADMAS) is proposed such that the degree of signal coherence relies on the local characteristics of the image region to maintain the background speckle quality and the corresponding contrast-to-noise ratio (CNR). Subsequently, the ADMAS algorithm is further combined with minimum variance (MV) beamforming to increase the image resolution. The optimal MV estimation is determined to be in the direction of the PW transmit angle (Tx) for multi-angle PW imaging. Our results show that, using the PICMUS dataset, TxMV-ADMAS beamforming significantly improves the image quality compared with CPWC. When the p value is globally fixed to 2 as in conventional DMAS, though the main-lobe width and the image contrast in the experiments improve from 0.57 mm and 27.0 dB in CPWC, respectively, to 0.24 mm and 38.0 dB, the corresponding CNR decreases from 12.8 to 11.3 due to the degraded speckle quality. With the proposed ADMAS algorithm, however, the adaptive p value in DMAS beamforming helps to restore the CNR value to the same level of CPWC while the improvement in image resolution and contrast remains evident.

3.
Anticancer Res ; 43(4): 1843-1851, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36974811

RESUMO

BACKGROUND/AIM: The effect of pelvic neoadjuvant radiotherapy (nRT) for stage M1a rectal adenocarcinoma patients treated with systemic therapy followed by proctectomy and metastasectomy was scarcely investigated in the literatures. PATIENTS AND METHODS: The eligible rectal cancer patients diagnosed between 2011-2019 were identified via the Taiwan Cancer Registry. In the primary analysis, we used propensity score weighting to balance observable potential confounders and compared the hazard ratio (HR) of death for the nRT group vs. without RT group. We also compared the incidence of rectal cancer mortality (IRCM) and performed various supplementary analyses. RESULTS: Our primary analyses included 145 patients. nRT was associated with improved OS (HR=0.51, p=0.01). The numerical trends remained similar for IRCM and in supplementary analyses. CONCLUSION: nRT was associated with improved OS in our study population.


Assuntos
Adenocarcinoma , Metastasectomia , Protectomia , Neoplasias Retais , Humanos , Terapia Neoadjuvante , Estudos Retrospectivos , Resultado do Tratamento , Neoplasias Retais/radioterapia , Neoplasias Retais/cirurgia , Adenocarcinoma/cirurgia , Adenocarcinoma/patologia , Estadiamento de Neoplasias
4.
Ecol Evol ; 12(1): e8525, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35136563

RESUMO

Density dependence and habitat heterogeneity have been recognized as important driving mechanisms that shape the patterns of seedling survival and promote species coexistence in species-rich forests. In this study, we evaluated the relative importance of density dependence by conspecific, heterospecific, and phylogenetically related neighbors and habitat heterogeneity on seedling survival in the Lienhuachih (LHC) Forest, a subtropical, evergreen forest in central Taiwan. Age-specific effects of different variables were also studied. We monitored the fates of 1,642 newly recruited seedlings of woody plants within a 25-ha Forest Dynamics Plot for 2 years. The effects of conspecific, heterospecific, and phylogenetically related neighbors and habitat heterogeneity on seedling survival were analyzed by generalized linear mixed models. Our results indicated that conspecific negative density dependence (CNDD) had a strong impact on seedling survival, and the effects of CNDD increased with seedling age. Heterospecific positive density dependence (HPDD) and phylogenetic positive density dependence (PPDD) had a significant influence on the survival of seedlings, and stronger HPDD and PPDD effects were detected for older seedlings. Furthermore, seedling survival differed among habitats significantly. Seedling survival was significantly higher in the plateau, high-slope, and low-slope habitats than in the valley. Overall, our results suggested that the effects of CNDD, HPDD, PPDD, and habitat heterogeneity influenced seedling survival simultaneously in the LHC subtropical forest, but their relative importance varied with seedling age. Such findings from our subtropical forest were slightly different from tropical forests, and these contrasting patterns may be attributed to differences in abiotic environments. These findings highlight the importance to incorporate phylogenetic relatedness, seedling age, and habitat heterogeneity when investigating the impacts of density dependence on seedling survival that may contribute to species coexistence in seedling communities.

5.
Mitochondrial DNA B Resour ; 6(12): 3369-3371, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34805514

RESUMO

The plastid genome of the deep-shade plant Selaginella erythropus, which has highly unusual chloroplasts, was characterized using Illumina pair-end sequencing. This plastome is 140,151 bp in length with a large single-copy region (LSC) of 56,133 bp, a small single-copy region (SSC) of 61,268 bp, and two direct repeats (DRs) of 11,375 bp. The overall GC content is 50.68%, while those of LSC, SSC, and DR are 48.96%, 50.3%, and 55.96%, respectively. The plastome contains 102 genes, including 76 protein-coding, 15 tRNA (12 tRNA species), and 8 rRNA genes (4 rRNA species). The phylogenetic analysis shows that S. erythropus is closely related to S. moellendorffii and S. doederleinii. This result is consistent with the previous phylogenetic relationship inferred from multiple plastid and nuclear loci. However, only S. erythropus has the two-zoned giant chloroplast, the bizonoplast. The plastome provides an excellent reference for understanding the unique chloroplast differentiation in Selaginellaceae.

6.
Biomedicines ; 9(8)2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34440230

RESUMO

Mutated channelopathy could play important roles in the pathogenesis of aldosterone-producing adenoma (APA). In this study, we identified a somatic mutation, KCNJ5 157-159delITE, and reported its immunohistological, pathophysiological and pharmacological characteristics. We conducted patch-clamp experiments on HEK293T cells and experiments on expression of aldosterone synthase (CYP11B2) and aldosterone secretion in HAC15 cells to evaluate electrophysiological and functional properties of this mutated KCNJ5. Immunohistochemistry was conducted to identify expressions of several steroidogenic enzymes. Macrolide antibiotics and a calcium channel blocker were administrated to evaluate the functional attenuation of mutated KCNJ5 channel in transfected HAC15 cells. The interaction between macrolides and KCNJ5 protein was evaluated via molecular docking and molecular dynamics simulation analysis. The immunohistochemistry analysis showed strong CYP11B2 immunoreactivity in the APA harboring KCNJ5 157-159delITE mutation. Whole-cell patch-clamp data revealed that mutated KCNJ5 157-159delITE channel exhibited loss of potassium ion selectivity. The mutant-transfected HAC15 cells increased the expression of CYP11B2 and aldosterone secretion, which was partially suppressed by clarithromycin and nifedipine but not roxithromycin treatment. The docking analysis and molecular dynamics simulation disclosed that roxithromycin had strong interaction with KCNJ5 L168R mutant channel but not with this KCNJ5 157-159delITE mutant channel. We showed comprehensive evaluations of the KCNJ5 157-159delITE mutation which revealed that it disrupted potassium channel selectivity and aggravated autonomous aldosterone production. We further demonstrated that macrolide antibiotics, roxithromycin, could not interfere the aberrant electrophysiological properties and gain-of-function aldosterone secretion induced by KCNJ5 157-159delITE mutation.

7.
Cell Death Dis ; 12(5): 409, 2021 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-33866326

RESUMO

The levels of fibroblast growth factor 23 (FGF23) rapidly increases after acute kidney injury (AKI). However, the role of FGF23 in AKI is still unclear. Here, we observe that pretreatment with FGF23 protein into ischemia-reperfusion induced AKI mice ameliorates kidney injury by promoting renal tubular regeneration, proliferation, vascular repair, and attenuating tubular damage. In vitro assays demonstrate that SDF-1 induces upregulation of its receptor CXCR4 in endothelial progenitor cells (EPCs) via a non-canonical NF-κB signaling pathway. FGF23 crosstalks with the SDF-1/CXCR4 signaling and abrogates SDF-1-induced EPC senescence and migration, but not angiogenesis, in a Klotho-independent manner. The downregulated pro-angiogenic IL-6, IL-8, and VEGF-A expressions after SDF-1 infusion are rescued after adding FGF23. Diminished therapeutic ability of SDF-1-treated EPCs is counteracted by FGF23 in a SCID mouse in vivo AKI model. Together, these data highlight a revolutionary and important role that FGF23 plays in the nephroprotection of IR-AKI.


Assuntos
Injúria Renal Aguda/metabolismo , Células Progenitoras Endoteliais/metabolismo , Fatores de Crescimento de Fibroblastos/metabolismo , Receptores CXCR4/metabolismo , Injúria Renal Aguda/patologia , Animais , Células Progenitoras Endoteliais/patologia , Fator de Crescimento de Fibroblastos 23 , Masculino , Camundongos , Camundongos SCID
8.
Am J Bot ; 107(4): 562-576, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32227348

RESUMO

PREMISE: Unique among vascular plants, some species of Selaginella have single giant chloroplasts in their epidermal or upper mesophyll cells (monoplastidy, M), varying in structure between species. Structural variants include several forms of bizonoplast with unique dimorphic ultrastructure. Better understanding of these structural variants, their prevalence, environmental correlates and phylogenetic association, has the potential to shed new light on chloroplast biology unavailable from any other plant group. METHODS: The chloroplast ultrastructure of 76 Selaginella species was studied with various microscopic techniques. Environmental data for selected species and subgeneric relationships were compared against chloroplast traits. RESULTS: We delineated five chloroplast categories: ME (monoplastidy in a dorsal epidermal cell), MM (monoplastidy in a mesophyll cell), OL (oligoplastidy), Mu (multiplastidy, present in the most basal species), and RC (reduced or vestigial chloroplasts). Of 44 ME species, 11 have bizonoplasts, cup-shaped (concave upper zone) or bilobed (basal hinge, a new discovery), with upper zones of parallel thylakoid membranes varying subtly between species. Monoplastidy, found in 49 species, is strongly shade associated. Bizonoplasts are only known in deep-shade species (<2.1% full sunlight) of subgenus Stachygynandrum but in both the Old and New Worlds. CONCLUSIONS: Multiplastidic chloroplasts are most likely basal, implying that monoplastidy and bizonoplasts are derived traits, with monoplastidy evolving at least twice, potentially as an adaptation to low light. Although there is insufficient information to understand the adaptive significance of the numerous structural variants, they are unmatched in the vascular plants, suggesting unusual evolutionary flexibility in this ancient plant genus.


Assuntos
Selaginellaceae , Traqueófitas , Evolução Biológica , Cloroplastos , Filogenia , Folhas de Planta
9.
Sci Rep ; 7(1): 5341, 2017 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-28706224

RESUMO

Genetic variation evolves during postglacial range expansion of a species and is important for adapting to varied environmental conditions. It is crucial for the future survival of a species. We investigate the nuclear DNA sequence variation to provide evidence of postglacial range expansion of Musa basjoo var. formosana, a wild banana species, and test for adaptive evolution of amplified fragment length polymorphic (AFLP) loci underlying local adaptation in association with environmental variables. Postglacial range expansion was suggested by phylogeographical analyses based on sequence variation of the second intron of copper zinc superoxide dismutase 2 gene. Two glacial refugia were inferred by the average F ST parameter (mean F ST of a population against the remaining populations). Using variation partitioning by redundancy analysis, we found a significant amount of explained AFLP variation attributed to environmental and spatially-structured environmental effects. By combining genome scan methods and multiple univariate logistic regression, four AFLP loci were found to be strongly associated with environmental variables, including temperature, precipitation, soil moisture, wet days, and surface coverage activity representing vegetation greenness. These environmental variables may have played various roles as ecological drivers for adaptive evolution of M. basjoo var. formosana during range expansion after the last glacial maximum.


Assuntos
Ecossistema , Musa/crescimento & desenvolvimento , Dispersão Vegetal , Adaptação Biológica , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Clima , DNA de Plantas/genética , Variação Genética , Genética Populacional , Musa/classificação , Musa/genética , Filogeografia
10.
Anticancer Res ; 36(11): 6155-6160, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27793945

RESUMO

BACKGROUND/AIM: Capecitabine is the current standard oral chemotherapy used in neoadjuvant concurrent chemoradiotherapy (NCCRT) for locally advanced rectal cancer (LARC) in North America. We compared the effectiveness of another oral chemotherapy agent, UFT (an oral combination of uracil and tegafur), to that of capecitabine. MATERIALS AND METHODS: We identified LARC patients diagnosed from 2007 to 2011 using a population-based registry in Taiwan (Health and Welfare Data Science Center, HWDC) and constructed a propensity score matched cohort to balance observable potential confounders. We compared the hazard ratio (HR) of death between the UFT and capecitabine groups. We performed supplementary analysis (SA) to evaluate the robustness of our finding regarding potential unobserved confounders (SA-1) and the robustness of the result in a subgroup when an additional potential confounder was taken into account (SA-2). RESULTS: Our study population comprised of 200 patients balanced with respect to observed co-variables. UFT lowered the hazard of death significantly more than capecitabine (HR=0.58, 95% confidence interval (CI)=0.35-0.95, p=0.03). Our result was moderately sensitive in SA-1 but not significant in SA-2. CONCLUSION: The effectiveness of UFT in NCCRT for LARC is probably non-inferior to that of capecitabine.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Retais/tratamento farmacológico , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Capecitabina/administração & dosagem , Quimioterapia Adjuvante , Feminino , Humanos , Masculino , Indução de Remissão , Taxa de Sobrevida , Tegafur/administração & dosagem , Uracila/administração & dosagem
11.
Ecol Evol ; 6(17): 6085-96, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27648227

RESUMO

A fundamental goal in ecology is to link variation in species function to performance, but functional trait-performance investigations have had mixed success. This indicates that less commonly measured functional traits may more clearly elucidate trait-performance relationships. Despite the potential importance of leaf vein traits, which are expected to be related to resource delivery rates and photosynthetic capacity, there are few studies, which examine associations between these traits and demographic performance in communities. Here, we examined the associations between species traits including leaf venation traits and demographic rates (Relative Growth Rate, RGR and mortality) as well as the spatial distributions of traits along soil environment for 54 co-occurring species in a subtropical forest. Size-related changes in demographic rates were estimated using a hierarchical Bayesian approach. Next, Kendall's rank correlations were quantified between traits and estimated demographic rates at a given size and between traits and species-average soil environment. Species with denser venation, smaller areoles, less succulent, or thinner leaves showed higher RGR for a wide range of size classes. Species with leaves of denser veins, larger area, cheaper construction costs or thinner, or low-density wood were associated with high mortality rates only in small size classes. Lastly, contrary to our expectations, acquisitive traits were not related to resource-rich edaphic conditions. This study shows that leaf vein traits are weakly, but significantly related to tree demographic performance together with other species traits. Because leaf traits associated with an acquisitive strategy such as denser venation, less succulence, and thinner leaves showed higher growth rate, but similar leaf traits were not associated with mortality, different pathways may shape species growth and survival. This study suggests that we are still not measuring some of key traits related to resource-use strategies, which dictate the demography and distributions of species.

12.
Sci Rep ; 5: 15127, 2015 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-26456472

RESUMO

To determine how well DNA barcodes from the chloroplast region perform in forest dynamics plots (FDPs) from global CTFS-ForestGEO network, we analyzed DNA barcoding sequences of 1277 plant species from a wide phylogenetic range (3 FDPs in tropics, 5 in subtropics and 5 in temperate zone) and compared the rates of species discrimination (RSD). We quantified RSD by two DNA barcode combinations (rbcL + matK and rbcL + matK + trnH-psbA) using a monophyly-based method (GARLI). We defined two indexes of closely-related taxa (Gm/Gt and S/G ratios) and correlated these ratios with RSD. The combination of rbcL + matK averagely discriminated 88.65%, 83.84% and 72.51% at the local, regional and global scales, respectively. An additional locus trnH-psbA increased RSD by 2.87%, 1.49% and 3.58% correspondingly. RSD varied along a latitudinal gradient and were negatively correlated with ratios of closely-related taxa. Successes of species discrimination generally depend on scales in global FDPs. We suggested that the combination of rbcL + matK + trnH-psbA is currently applicable for DNA barcoding-based phylogenetic studies on forest communities.


Assuntos
Código de Barras de DNA Taxonômico/métodos , DNA de Plantas/genética , Filogenia , Árvores/genética , Cloroplastos/genética , Clima , Endorribonucleases/genética , Florestas , Expressão Gênica , Loci Gênicos , Histidina-tRNA Ligase/genética , Nucleotidiltransferases/genética , Complexo de Proteína do Fotossistema II/genética , Ribulose-Bifosfato Carboxilase/genética , Análise de Sequência de DNA , Especificidade da Espécie , Árvores/classificação
13.
BMJ ; 351: h4848, 2015 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-26399967

RESUMO

OBJECTIVE: To evaluate the use of prospective screening for the HLA-B*58:01 allele to identify Taiwanese individuals at risk of severe cutaneous adverse reactions (SCARs) induced by allopurinol treatment. DESIGN: National prospective cohort study. SETTING: 15 medical centres in different regions of Taiwan, from July 2009 to August 2014. PARTICIPANTS: 2926 people who had an indication for allopurinol treatment but had not taken allopurinol previously. Participants were excluded if they had undergone a bone marrow transplant, were not of Han Chinese descent, and had a history of allopurinol induced hypersensitivity. DNA purified from 2910 participants' peripheral blood was used to assess the presence of HLA-B*58:01. MAIN OUTCOME MEASURES: Incidence of allopurinol induced SCARs with and without screening. RESULTS: Participants who tested positive for HLA-B*58:01 (19.6%, n=571) were advised to avoid allopurinol, and were referred to an alternate drug treatment or advised to continue with their prestudy treatment. Participants who tested negative (80.4%, n=2339) were given allopurinol. Participants were interviewed once a week for two months to monitor symptoms. The historical incidence of allopurinol induced SCARs, estimated by the National Health Insurance research database of Taiwan, was used for comparison. Mild, transient rash without blisters developed in 97 (3%) participants during follow-up. None of the participants was admitted to hospital owing to adverse drug reactions. SCARs did not develop in any of the participants receiving allopurinol who screened negative for HLA-B*58:01. By contrast, seven cases of SCARs were expected, based on the estimated historical incidence of allopurinol induced SCARs nationwide (0.30% per year, 95% confidence interval 0.28% to 0.31%; P=0.0026; two side one sample binomial test). CONCLUSIONS: Prospective screening of the HLA-B*58:01 allele, coupled with an alternative drug treatment for carriers, significantly decreased the incidence of allopurinol induced SCARs in Taiwanese medical centres.


Assuntos
Alopurinol/efeitos adversos , Toxidermias/prevenção & controle , Supressores da Gota/efeitos adversos , Antígenos HLA-B/genética , Doença Crônica , Toxidermias/genética , Exantema/induzido quimicamente , Feminino , Testes Genéticos , Genótipo , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Prurido/induzido quimicamente , Taiwan
14.
J Control Release ; 213: 69-78, 2015 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-26164036

RESUMO

A novel nanovesicle carrier, phosphatiosomes, was developed to enhance the targeting efficiency of phosphodiesterase 4 (PDE4) inhibitor to the lungs for treating acute lung injury (ALI) by intravenous administration. Phosphatiosomes were the basis of a niosomal system containing phosphatidylcholine (PC) and distearoylphosphatidylethanolamine polyethylene glycol (DSPE-PEG). Rolipram was used as the model drug loaded in the phosphatiosomes. Bioimaging, biodistribution, activated neutrophil inhibition, and ALI treatment were performed to evaluate the feasibility of phosphatiosomes as the lung-targeting carriers. An encapsulation percentage of >90% was achieved for rolipram-loaded nanovesicles. The vesicle size and zeta potential of the phosphatiosomes were 154 nm and -34 mV, respectively. Real-time imaging in rats showed a delayed and lower uptake of phosphatiosomes by the liver and spleen. Ex vivo bioimaging demonstrated a high accumulation of phosphatiosomes in the lungs. In vivo biodistribution exhibited increased lung accumulation and reduced brain penetration of rolipram in phosphatiosomes relative to the control solution. Phosphatiosomes improved the lungs/brain ratio of the drug by more than 7-fold. Interaction with pulmonary lipoprotein surfactants and the subsequent aggregation may be the mechanisms for facilitating lung targeting by phosphatiosomes. Rolipram could continue to inhibit active neutrophils after inclusion in the nanovesicles by suppressing O2(-) generation and elevating cAMP. Phosphatiosomes significantly alleviated ALI in mice as revealed by examining their pulmonary appearance, edema, myeloperoxidase (MPO) activity, and histopathology. This study highlights the potential of nanovesicles to deliver the drug for targeting the lungs and attenuating nervous system side effects.


Assuntos
Lesão Pulmonar Aguda/tratamento farmacológico , Portadores de Fármacos/química , Pulmão/efeitos dos fármacos , Fosfatidilcolinas/química , Fosfatidiletanolaminas/química , Inibidores da Fosfodiesterase 4/administração & dosagem , Rolipram/administração & dosagem , Lesão Pulmonar Aguda/patologia , Adulto , Animais , Células Cultivadas , Sistemas de Liberação de Medicamentos , Humanos , Pulmão/patologia , Masculino , Camundongos Endogâmicos C57BL , Inibidores da Fosfodiesterase 4/farmacocinética , Inibidores da Fosfodiesterase 4/uso terapêutico , Polietilenoglicóis/química , Ratos Sprague-Dawley , Rolipram/farmacocinética , Rolipram/uso terapêutico , Distribuição Tecidual , Adulto Jovem
15.
Opt Express ; 23(9): 11205-10, 2015 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-25969216

RESUMO

We propose and demonstrate a passively Q-switched 1900-nm thulium all-fiber laser using the mode-field-area mismatch method. A thulium fiber laser was core-pumped at 1590 nm and saturable-absorber Q-switched at 1900 nm through the use of a thulium saturable absorber fiber that had a relatively smaller mode field area than the gain medium. Sequential pulsing with a pulse energy of 12 µJ and a pulse duration of 160 ns was obtained. The pulse repetition rate was increased linearly with the applied pump power. With a pump power of 4.5 W, an average output power of 0.61 W and a pulse repetition rate of 50.7 kHz were achieved.

16.
J Mater Chem B ; 3(4): 651-664, 2015 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-32262348

RESUMO

Here, we report the development of a multifunctional nanocarrier consisting of paramagnetic graphene quantum dots (GQDs), folate, and doxorubicin (Dox), used as delivery vehicles, a targeting ligand, and a chemotherapeutic drug, respectively. The paramagnetic GQDs, named folate-GdGQDs, were successfully prepared by covalently conjugating diethylenetriaminepentaacetic acid gadolinium and folic acid onto the surface of GQDs. The resultant folate-GdGQDs, which showed a longitudinal relaxivity r1 of 11.49 mM-1 s-1, greatly enhanced the brightness of the T1-weighted magnetic resonance (MR) images, indicating their potential for use as positive contrast agents for MR imaging (MRI). The feasibility of utilizing the folate-GdGQDs with strong luminescence emissions for targeted imaging of HeLa cells was also evaluated. An in vitro cell (HeLa and HepG2 cells) viability assay and in vivo evaluation of toxicity to the embryonic development of zebrafish showed that these folate-GdGQDs exhibited negligible cytotoxicity and excellent biocompatibility within the given range of concentrations. More importantly, strong therapeutic activity was achieved by loading Dox onto the surfaces of folate-GdGQDs through π-π stacking and hydrophobic interactions, leading to the formation of folate-GdGQD/Dox multifunctional nanocarriers. Approximately 80% of the loaded Dox was released from the folate-GdGQD/Dox nanocarriers under mild acidic conditions (pH 5.0), whereas only 20% of Dox was released at pH 7.0 after 48 h. Furthermore, these multifunctional nanocarriers could efficiently induce an inhibitory effect on HeLa cells, as confirmed by an in vitro cytotoxicity assay. The combined flow cytometry analysis and confocal laser scanning microscopic observation showed that these nanocarriers were efficiently taken up by the cancer cells overexpressing folate receptors. Taken together, these results suggested that the multifunctional nanocarriers could be used as promising targeted drug delivery vehicles for the diagnosis and image-guided chemotherapy of various cancers.

17.
Front Genet ; 5: 358, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25414723

RESUMO

Forest dynamics plots, which now span longitudes, latitudes, and habitat types across the globe, offer unparalleled insights into the ecological and evolutionary processes that determine how species are assembled into communities. Understanding phylogenetic relationships among species in a community has become an important component of assessing assembly processes. However, the application of evolutionary information to questions in community ecology has been limited in large part by the lack of accurate estimates of phylogenetic relationships among individual species found within communities, and is particularly limiting in comparisons between communities. Therefore, streamlining and maximizing the information content of these community phylogenies is a priority. To test the viability and advantage of a multi-community phylogeny, we constructed a multi-plot mega-phylogeny of 1347 species of trees across 15 forest dynamics plots in the ForestGEO network using DNA barcode sequence data (rbcL, matK, and psbA-trnH) and compared community phylogenies for each individual plot with respect to support for topology and branch lengths, which affect evolutionary inference of community processes. The levels of taxonomic differentiation across the phylogeny were examined by quantifying the frequency of resolved nodes throughout. In addition, three phylogenetic distance (PD) metrics that are commonly used to infer assembly processes were estimated for each plot [PD, Mean Phylogenetic Distance (MPD), and Mean Nearest Taxon Distance (MNTD)]. Lastly, we examine the partitioning of phylogenetic diversity among community plots through quantification of inter-community MPD and MNTD. Overall, evolutionary relationships were highly resolved across the DNA barcode-based mega-phylogeny, and phylogenetic resolution for each community plot was improved when estimated within the context of the mega-phylogeny. Likewise, when compared with phylogenies for individual plots, estimates of phylogenetic diversity in the mega-phylogeny were more consistent, thereby removing a potential source of bias at the plot-level, and demonstrating the value of assessing phylogenetic relationships simultaneously within a mega-phylogeny. An unexpected result of the comparisons among plots based on the mega-phylogeny was that the communities in the ForestGEO plots in general appear to be assemblages of more closely related species than expected by chance, and that differentiation among communities is very low, suggesting deep floristic connections among communities and new avenues for future analyses in community ecology.

19.
Pharm Res ; 31(10): 2664-76, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24906596

RESUMO

PURPOSE: Here we report the development of quantiosomes, niosomes formed from Span 60, cholesterol, and quantum dots (QDs), for achieving sensitive bioimaging and anticancer drug delivery. METHODS: The nanocarriers were further modified by incorporating soy phosphatidylcholine (SPC), polyethylene glycol (PEG), or cationic surfactant to display different efficiencies. Carboplatin was used as the model drug. The cellular uptake, cytotoxicity, and migration inhibition of quantiosomes for treating melanoma cells were described. Finally, intratumoral carboplatin accumulation and in-vivo bioimaging were examined. RESULTS: The average diameters of quantiosomes ranged between 151 and 173 nm, depending on the composition selected. Approximately 50% of the drug was entrapped in quantiosomes. Electron microscopy confirmed the bilayer structure of quantiosomes and the presence of QDs in the vesicular surface. The nanodispersions showed a significant internalization into cells, especially the cationic formulations. Quantiosomes increased cytotoxicity against melanoma by 3 ~ 4-fold as compared to free carboplatin. In-vivo intratumoral administration demonstrated an increased drug depot in melanoma from 6 to 10 ng/mg by SPC-loaded and PEGylated quantiosomes relative to aqueous control. In-vivo fluorescence imaging showed that quantiosomes reduced leakage of QDs from melanoma. A fluorescence signal confined in tumors could be sustained for at least 24 h. Quantiosomes also exhibited a sensitive and prolonged fluorescence in ovarian tumors. CONCLUSION: Niosomes containing QDs and carboplatin as a multifunctional nanosystems provide a non-expensive and efficient strategy to prolong drug retention and fluorescence signal in tumors.


Assuntos
Antineoplásicos/administração & dosagem , Carboplatina/administração & dosagem , Diagnóstico por Imagem/métodos , Portadores de Fármacos/química , Pontos Quânticos/química , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Carboplatina/farmacocinética , Carboplatina/farmacologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Colesterol/química , Composição de Medicamentos , Liberação Controlada de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Hexoses/química , Lipossomos , Melanoma/patologia , Camundongos Nus , Transplante de Neoplasias , Imagem Óptica/métodos , Neoplasias Ovarianas/patologia , Tamanho da Partícula , Propriedades de Superfície
20.
Guang Pu Xue Yu Guang Pu Fen Xi ; 33(1): 190-5, 2013 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-23586254

RESUMO

The retrieval of snow grain size is one of the important research directions for cryosphere snow remote sensing. In the present study, we designed the measurement plan of different snow grain size by different snow layer. A SVC HR-1024 ground-based spectral radiometer was used for measuring the spectral property of different snow grain size in northern Xinjiang, China. At the same time, the snow grain size and shape were measured by a hand-loupe with scale. Then the DSPP method was used to calculate the equivalent snow grain size. Finally, the asymptotic radiative transfer (ART) theory was applied to retrieve the snow grain size from measured snow spectral reflectance of different snow layer by optimizing the inversion band and the snow grain size factor "b". The retrieved snow grain size was validated by the measured snow grain size from DSPP method. The results showed that the DSPP method is an effective means of measuring the equivalent snow grain size. However, there is a large deviation of the snow grain size sample in the same snow layer. It is necessary to improve the measurement method of the single snow grain size sample; The study showed that the near-infrared bands are the most effective selection for retrieval of snow grain size. The retrieval algorithm from ART is feasible. When the snow is dry, the authors optimize the inversion band and the snow grain size factor b in the Northern Xinjiang, China. The optimal band wavelength is 1.20 microm and b is 3.62.

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