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"Kuo, P. T"
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Are the floral morphology and anatomy of Galphimia australis, an atypical neotropical Malpighiaceae, associated to a new pollination syndrome?
2023
The flowers of the species of Malpighiaceae in the Neotropical Region are relatively uniform in their morphology due to their dependence on oil-collecting bees as their main pollinators. However, many species of the genus Galphimia seem to have acquired a different floral syndrome, lacking markedly zygomorphic flowers and developed elaiophores in the calyx. Likewise, these species present anthers with great development, probably in response to the selection of pollinators that collect pollen. Galphimia australis incorporated some of these traits but also retained some residual characteristics typical of species pollinated by oil bees. This leads to many questions on how these flowers ensure their pollination. Inquiring about the reduction or modification of these characteristics allows us to understand how G. australis achieves a different pollination syndrome. In this research, we carry out a detailed morphological and anatomical study of the flowers and pollen grain devolvement of G. australis and floral visitors were observed and captured. Results were analyzed in order to determine how this species changed from the oil-floral syndrome, typical of neotropical Malpighiaceae, to one syndrome with pollen as the main reward.
Journal Article
Addressable Cell Microarrays via Switchable Superhydrophobic Surfaces
In the areas of genomics and proteomics, there are increasing demands for the
development of novel patterning techniques to create arrays of functional biomolecules or cells on the miniaturized devices, which could be used in various
large-scale biomedical applications such as biosensing, proteomics, immunoassays
or drug screening [1, 2]. Several processes have been demonstrated which are capable of patterning biomolecules with very high degree of spatial control including
dip-pen lithography, inkjet printing, photolithography, nanoimprinting, etc. [3-10].
While the serial writing techniques provide individual addressability, the parallel
printing processes offer an easy and fast protein patterning. However, very few of
the above-mentioned techniques are capable of patterning cells. The cell microarrays, which provide the native environments for various biochemical reactions, are
often used to investigate the expression of genes and the function of proteins [11]. In
the past few years, many schemes have been proposed to fabricate cells microarrays[12]. One of the most popular approaches is to print biomolecules on a chip where
the desired types of cells are cultured. However, in such type of cell microarray,
the cells are not confined. The separation of different colonies sometime becomes
problematic. Another approach is to employ micro-contact printing where the extracellular matrix (ECM) molecules such as fibronectin, vitronecin and collagens
are first patterned on the surfaces [13]. Then the growth of cells on the surfaces
is guided through binding to these ECM molecules. However, in these two cases,
only one type of cells can be used on a chip. Here we report the use of switchable
superhydrophobic surfaces to create cell microarrays where two or more types of
cells can simultaneously be cultured on different areas of the same chip.
Book Chapter
The metabolome profiling and pathway analysis in metabolic healthy and abnormal obesity
2015
Objectives:
Mechanisms of the development of abnormal metabolic phenotypes among obese population are not yet clear. In this study, we aimed to screen metabolomes of both healthy and subjects with abnormal obesity to identify potential metabolic pathways that may regulate the different metabolic characteristics of obesity.
Methods:
We recruited subjects with body mass index (BMI) over 25 from the weight-loss clinic of a central hospital in Taiwan. Metabolic healthy obesity (MHO) is defined as without having any form of hyperglycemia, hypertension and dyslipidemia, while metabolic abnormal obesity (MAO) is defined as having one or more abnormal metabolic indexes. Serum-based metabolomic profiling using both liquid chromatography–mass spectrometry and gas chromatography–mass spectrometry of 34 MHO and MAO individuals with matching age, sex and BMI was performed. Conditional logistic regression and partial least squares discriminant analysis were applied to identify significant metabolites between the two groups. Pathway enrichment and topology analyses were conducted to evaluate the regulated pathways.
Results:
A differential metabolite panel was identified to be significantly differed in MHO and MAO groups, including L-kynurenine, glycerophosphocholine (GPC), glycerol 1-phosphate, glycolic acid, tagatose, methyl palmitate and uric acid. Moreover, several metabolic pathways were relevant in distinguishing MHO from MAO groups, including fatty acid biosynthesis, phenylalanine metabolism, propanoate metabolism, and valine, leucine and isoleucine degradation.
Conclusion:
Different metabolomic profiles and metabolic pathways are important for distinguishing between MHO and MAO groups. We have identified and discussed the key metabolites and pathways that may prove important in the regulation of metabolic traits among the obese, which could provide useful clues to study the underlying mechanisms of the development of abnormal metabolic phenotypes.
Journal Article
Overcoming Kerr-induced capacity limit in optical fiber transmission
2015
Nonlinear optical response of silica imposes a fundamental limit on the information transfer capacity in optical fibers. Communication beyond this limit requires higher signal power and suppression of nonlinear distortions to prevent irreversible information loss. The nonlinear interaction in silica is a deterministic phenomenon that can, in principle, be completely reversed. However, attempts to remove the effects of nonlinear propagation have led to only modest improvements, and the precise physical mechanism preventing nonlinear cancellation remains unknown. We demonstrate that optical carrier stability plays a critical role in canceling Kerr-induced distortions and that nonlinear wave interaction in silica can be substantially reverted if optical carriers possess a sufficient degree of mutual coherence. These measurements indicate that fiber information capacity can be notably increased over previous estimates.
Journal Article
Subnoise detection of a fast random event
Observation of random, nonrepetitive phenomena is of critical importance in astronomy, spectroscopy, biology, and remote sensing. Heralded by weak signals, hidden in noise, they pose basic detection challenges. In contrast to repetitive waveforms, a single-instance signal cannot be separated from noise through averaging. Here, we show that a fast, randomly occurring event can be detected and extracted from a noisy background without conventional averaging. An isolated 80-picosecond pulse was received with confidence level exceeding 99%, even when accompanied by noise. Our detector relies on instantaneous spectral cloning and a single-step, coherent field processor. The ability to extract fast, subnoise events is expected to increase detection sensitivity in multiple disciplines. Additionally, the new spectral-cloning receiver can potentially intercept communication signals that are presently considered secure.
Journal Article
Hypoxic lung cancer-secreted exosomal miR-23a increased angiogenesis and vascular permeability by targeting prolyl hydroxylase and tight junction protein ZO-1
Hypoxia plays a critical role during the evolution of malignant cells and tumour microenvironment (TME).Tumour-derived exosomes contain informative microRNAs involved in the interaction of cancer and stromal cells, thus contributing to tissue remodelling of tumour microenvironment. This study aims to clarify how hypoxia affects tumour angiogenesis through exosomes shed from lung cancer cells. Lung cancer cells produce more exosomes under hypoxic conditions than do parental cells under normoxic conditions. miR-23a was significantly upregulated in exosomes from lung cancer under hypoxic conditions. Exosomal miR-23a directly suppressed its target
prolyl hydroxylase 1 and 2
(PHD1 and 2), leading to the accumulation of hypoxia-inducible factor-1 α (HIF-1 α) in endothelial cells. Consequently, hypoxic lung cancer cells enhanced angiogenesis by exosomes derived from hypoxic cancer under both normoxic and hypoxic conditions. In addition, exosomal miR-23a also inhibits tight junction protein ZO-1, thereby increasing vascular permeability and cancer transendothelial migration. Inhibition of miR-23a by inhibitor administration decreased angiogenesis and tumour growth in a mouse model. Furthermore, elevated levels of circulating miR-23a are found in the sera of lung cancer patients, and miR-23a levels are positively correlated with proangiogenic activities. Taken together, our study reveals the clinical relevance and prognostic value of cancer-derived exosomal miR-23a under hypoxic conditions, and investigates a unique intercellular communication, mediated by cancer-derived exosomes, which modulates tumour vasculature.
Journal Article
Connective tissue growth factor modulates oral squamous cell carcinoma invasion by activating a miR-504/FOXP1 signalling
2012
Connective tissue growth factor (CTGF) is a multi-functional secreted protein, and it has been shown either to promote or suppress tumor progression among different kinds of cancers. Here, we investigated the role of CTGF in oral squamous cell carcinoma (OSCC) invasion and metastasis. In five OSCC cell lines, endogenous CTGF negatively correlated with invasiveness. Exogenous CTGF protein or forced expression of CTGF gene in the oral cancer cell line SAS significantly decreased their invasive and migratory abilities. MicroRNA (miRNA) microarray analysis was performed in CTGF-overexpressed SAS cells (SAS/CTGF-M3) versus control cells to investigate the mechanism of CTGF-mediated inhibition of OSCC invasion. Among the miRNAs regulated by CTGF, miR-504 and miR-346 were the top two miRNAs downregulated in CTGF transfectants, and the result was confirmed by quantitative reverse transcriptase–PCR. Ectopic miR-504 increased migration and invasion in SAS/CTGF-M3, however, miR-346 did not have such impact on migration/invasion. Furthermore, we identified
FOXP1
, a member of forkhead transcription factors, as a target gene that takes part in the miR-504-induced cellular invasion. Knockdown of FOXP1 increased invasiveness in SAS/CTGF-M3, confirming the signal axis of CTGF/miR-504/FOXP1 in OSCC. Animal experiments showed that SAS/CTGF-M3-formed orthotopic tumors were associated with a lesser invasive phenotype than control cells. Expression of miR-504 in SAS/CTGF-M3 increased lymph node metastasis, and co-expression of FOXP1 in miR-504-transfected SAS/CTGF-M3 alleviated miR-504-induced metastasis. In OSCC samples, high CTGF was associated with a lower clinical stage and a better outcome. A reverse correlation between CTGF and miR-504, miR-504 and FOXP1, and a positive correlation between CTGF and FOXP1 were shown. Our study discovers a novel signal pathway involving the regulation of miRNA machinery by a secreted cytokine, which will be beneficial for developing therapeutic strategy against advanced OSCC.
Journal Article
Boundary conformal field theory and a boundary central charge
by
Herzog, Christopher P.
,
Huang, Kuo-Wei
in
Anomalies in Field and String Theories
,
Boundary Quantum Field Theory
,
Classical and Quantum Gravitation
2017
A
bstract
We consider the structure of current and stress tensor two-point functions in conformal field theory with a boundary. The main result of this paper is a relation between a boundary central charge and the coefficient of a displacement operator correlation function in the boundary limit. The boundary central charge under consideration is the coefficient of the product of the extrinsic curvature and the Weyl curvature in the conformal anomaly. Along the way, we describe several auxiliary results. Three of the more notable are as follows: (1) we give the bulk and boundary conformal blocks for the current two-point function; (2) we show that the structure of these current and stress tensor two-point functions is essentially universal for all free theories; (3) we introduce a class of interacting conformal field theories with boundary degrees of freedom, where the interactions are confined to the boundary. The most interesting example we consider can be thought of as the infrared fixed point of graphene. This particular interacting conformal model in four dimensions provides a counterexample of a previously conjectured relation between a boundary central charge and a bulk central charge. The model also demonstrates that the boundary central charge can change in response to marginal deformations.
Journal Article
Effects of bihemispheric transcranial direct current stimulation on motor recovery in subacute stroke patients: a double-blind, randomized sham-controlled trial
by
Shyu, Kuo-Kai
,
Lee, I-Hui
,
Niddam, David M.
in
Biomarkers
,
Biomedical and Life Sciences
,
Biomedical Engineering and Bioengineering
2023
Background
Bihemispheric transcranial direct current stimulation (tDCS) of the primary motor cortex (M1) can simultaneously modulate bilateral corticospinal excitability and interhemispheric interaction. However, how tDCS affects subacute stroke recovery remains unclear. We investigated the effects of bihemispheric tDCS on motor recovery in subacute stroke patients.
Methods
We enrolled subacute inpatients who had first-ever ischemic stroke at subcortical regions and moderate-to-severe baseline Fugl-Meyer Assessment of Upper Extremity (FMA-UE) score 2–56. Participants between 14 and 28 days after stroke were double-blind, randomly assigned (1:1) to receive real (n = 13) or sham (n = 14) bihemispheric tDCS (with ipsilesional M1 anode and contralesional M1 cathode, 20 min, 2 mA) during task practice twice daily for 20 sessions in two weeks. Residual integrity of the ipsilesional corticospinal tract was stratified between groups. The primary efficacy outcome was the change in FMA-UE score from baseline (responder as an increase ≥ 10). The secondary measures included changes in the Action Research Arm Test (ARAT), FMA-Lower Extremity (FMA-LE) and explorative resting-state MRI functional connectivity (FC) of target regions after intervention and three months post-stroke.
Results
Twenty-seven participants completed the study without significant adverse effects. Nineteen patients (70%) had no recordable baseline motor-evoked potentials (MEP-negative) from the paretic forearm. Compared with the sham group, the real tDCS group showed enhanced improvement of FMA-UE after intervention (
p
< 0.01, effect size
η
2
= 0.211; responder rate: 77% vs. 36%,
p
= 0.031), which sustained three months post-stroke (
p
< 0.01), but not ARAT. Interestingly, in the MEP-negative subgroup analysis, the FMA-UE improvement remained but delayed. Additionally, the FMA-LE improvement after real tDCS was not significantly greater until three months post-stroke (
p
< 0.01). We found that the individual FMA-UE improvements after real tDCS were associated with bilateral intrahemispheric, rather than interhemispheric, FC strengths in the targeted cortices, while the improvements after sham tDCS were associated with predominantly ipsilesional FC changes after adjustment for age and sex (
p
< 0.01).
Conclusions
Bihemispheric tDCS during task-oriented training may facilitate motor recovery in subacute stroke patients, even with compromised corticospinal tract integrity. Further studies are warranted for tDCS efficacy and network-specific neuromodulation.
Trial registration
: This study is registered with ClinicalTrials.gov: (ID: NCT02731508).
Journal Article
A Phase 3 Trial of Luspatercept in Patients with Transfusion-Dependent β-Thalassemia
by
Thompson, Alexis
,
Aydinok, Yesim
,
Pazgal-Kobrowski, Idit
in
Activin Receptors, Type II - adverse effects
,
Activin Receptors, Type II - therapeutic use
,
Adolescent
2020
Patients with transfusion-dependent β-thalassemia were randomly assigned to receive luspatercept (a binder for TGF-β family member ligands) or placebo. During any 12-week period, a greater percentage of patients in the luspatercept group than in the placebo group had a reduction of at least 33% (70.5% vs. 29.5%) or at least 50% (40.2% vs. 6.3%) in the transfusion requirement.
Journal Article