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Find video protocols related to scientific articles indexed in Pubmed.
Hierarchical superstructures from a star-shaped molecule consisting of a cyclic oligosiloxane with cyanobiphenyl moieties.
Soft Matter
PUBLISHED: 11-20-2014
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Unconventional star-shaped liquid crystals (abbreviated as SiLCs) were successfully synthesized by chemically connecting four cyanobiphenyl anisotropic mesogens to the periphery of a super-hydrophobic and ultra-flexible cyclic tetramethyltetrasiloxane ring with flexible hexyl chains. Based on the combined experimental techniques of differential scanning calorimetry (DSC), cross-polarized optical microscopy (POM), solid-state carbon-13 ((13)C) nuclear magnetic resonance (NMR) spectroscopy and one-dimensional (1D) wide-angle X-ray diffraction (WAXD), it was found that the SiLC molecule exhibited the monotropic phase transition from a LC phase to a crystalline phase. The crystalline phase was only detected during slow heating processes above its glass transition temperature, while a LC phase was formed both during cooling and during heating processes. The hierarchical superstructures were identified from the structure-sensitive 2D WAXD of the macroscopically oriented SiLC film and confirmed by selected area electron diffraction (SAED) of the SiLC single crystals. The molecular packing symmetry in the monoclinic unit cell was further investigated by computer simulations on the real and reciprocal spaces. Macroscopically oriented SiLC hierarchical superstructures on the different length scales may provide the targeted physical properties, which can allow us to apply SiLC molecules in the fields of electro-optical devices and nonlinear optics.
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Dianthraceno[a,e]pentalenes: synthesis, crystallographic structures and applications in organic field-effect transistors.
Chem. Commun. (Camb.)
PUBLISHED: 11-20-2014
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Two soluble and stable dianthraceno[a,e]pentalenes with two () and six () phenyl substituents were synthesized. Both compounds possess a small energy band gap and show amphoteric redox behaviour due to intramolecular donor-accepter interactions. X-ray crystallographic analysis revealed that has a closely packed structure with multi-dimensional [C-H?] interactions although there are no ?-? interactions between the dianthraceno[a,e]pentalene cores. As a result, solution-processed field effect transistors based on exhibited an average hole mobility of 0.65 cm(2) V(-1) s(-1). Under similar conditions, showed an average field effect hole mobility of 0.001 cm(2) V(-1) s(-1).
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Low cord blood vitamin D levels are associated with increased milk sensitization in early childhood.
Pediatr Allergy Immunol
PUBLISHED: 11-13-2014
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The association between vitamin D status at birth and allergen sensitizations is uncertain. The aim of this study was to investigate the relationship of cord blood vitamin D status with allergen sensitizations and the development of atopic diseases in early childhood.
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Delayed-Onset Chylous Ascites After a Living-Donor Liver Transplant: First Case Successfully Treated With Conservative Treatment?
Exp Clin Transplant
PUBLISHED: 11-04-2014
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Chylous ascites is a rare complication in liver transplant. Few cases have been reported to date. In most cases, chylous ascites is diagnosed within 1 month after surgery because of intraoperative injury of the hilarlymphatic system. Preoperative massive ascites and use of a LigaSure vessel sealing system for hilar dissection have been reported as risk factors. We report a case of chylous ascites after a living-donor liver transplant that was diagnosed after 6 months of uneventful follow-up. Sirolimus was added to cyclosporine early (2 wk after the operation) owing to poor renal function and it was found to be high (> 22 ng/mL) when the chylous ascites occurred. The patient was treated with total parenteral nutrition in combination with Sandostatin and rapid tapering of sirolimus after the failed initial conservative treatment. Residual abdominal fullness after meals and lymphedema of the legs disappeared 1 month after discontinuing sirolimus. This is the first case of delayed-onset chylous ascites after a liver transplant that was successfully treated conservatively.
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Impact of LPS-Induced Cardiomyoblast Cell Apoptosis Inhibited by Earthworm Extracts.
Cardiovasc. Toxicol.
PUBLISHED: 09-25-2014
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Dilong is an earthworm extract with a dense nutritional content, widely used in Chinese herbal medicine to remove stasis and stimulate wound healing. Earthworm extracts are traditionally used by indigenous people throughout the world. How this Dilong inhibits Lipopolysaccharide (LPS)-induced cardiomyoblast cell apoptosis is still unclear. This study investigates the Dilong extract effect on LPS-induced apoptosis in H9c2 cardiomyoblast cells. LPS (1 ?g/ml) administration for 24 h induced apoptosis in H9c2 cells. Cell apoptosis was detected using MTT, LDH, TUNEL assay and JC-1 staining. Western blot analysis was used to detect pro-apoptotic and anti-apoptotic proteins. Dilong extract totally blocked the LPS impact, leading to the activation of anti-apoptotic proteins, Bcl-2 and Bcl-xL, stabilized the mitochondria membrane and down-regulated the extrinsic and intrinsic pro-apoptotic proteins, TNF-?, active caspase-8, t-Bid, Bax, active caspase-9 and active caspase-3. Dilong could potentially serve as a cardio protective agent against LPS-induced H9c2 cardiomyoblast cell apoptosis.
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Quantitative analysis of intrinsic skin aging in dermal papillae by in vivo harmonic generation microscopy.
Biomed Opt Express
PUBLISHED: 09-01-2014
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Chronological skin aging is associated with flattening of the dermal-epidermal junction (DEJ), but to date no quantitative analysis focusing on the aging changes in the dermal papillae (DP) has been performed. The aim of the study is to determine the architectural changes and the collagen density related to chronological aging in the dermal papilla zone (DPZ) by in vivo harmonic generation microscopy (HGM) with a sub-femtoliter spatial resolution. We recruited 48 Asian subjects and obtained in vivo images on the sun-protected volar forearm. Six parameters were defined to quantify 3D morphological changes of the DPZ, which we analyzed both manually and computationally to study their correlation with age. The depth of DPZ, the average height of isolated DP, and the 3D interdigitation index decreased with age, while DP number density, DP volume, and the collagen density in DP remained constant over time. In vivo high-resolution HGM technology has uncovered chronological aging-related variations in DP, and sheds light on real-time quantitative skin fragility assessment and disease diagnostics based on collagen density and morphology.
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Population-based cohort study on the risk of malignancy in East Asian children with juvenile idiopathic arthritis.
BMC Cancer
PUBLISHED: 08-29-2014
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To investigate the association and magnitude of risk between JIA, its associated treatment and cancer development in Taiwanese children.
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Persistent improper upregulation of Th17 and TReg cells in patients with juvenile idiopathic arthritis.
J Microbiol Immunol Infect
PUBLISHED: 08-28-2014
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Juvenile idiopathic arthritis (JIA) is the most common childhood rheumatic disease. A break in the balance between Th17 and TReg cells has been reported as an important factor in the development of autoimmune diseases. This study aimed to analyze peripheral Th17 and TReg cell levels in patients with JIA.
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Resveratrol enhanced FOXO3 phosphorylation via synergetic activation of SIRT1 and PI3K/Akt signaling to improve the effects of exercise in elderly rat hearts.
Age (Dordr)
PUBLISHED: 08-27-2014
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Exercise training is considered a benefit to heart function, but the benefit in aging hearts remains unknown. Activation of the PI3K-Akt survival pathway and suppression of Fas/FADD/caspase-8 apoptotic signaling by exercise training in hearts from young subjects have been described in our previous studies. However, the mechanisms are still unclear and need to be explored in aging hearts. Thus, 18-month-old rats were used as a model and underwent swimming exercise training, resveratrol treatment (15 mg/kg/day), or exercise training with resveratrol treatment for 1 month. The results showed that heart function in each group improved. However, the 18-month-old rats in the exercise-only group experienced the slightly inevitable impact of increased TNF-?, cell apoptosis, and fibrosis. In the protein analysis, the PI3K-Akt pathway was slightly increased with exercise training and resveratrol treatment, but Sirtuin 1 (SIRT1) was only highly activated with resveratrol treatment in the aged rat hearts. Moreover, the exercise training plus resveratrol group benefited from SIRT1 and PI3K-Akt dual pathways and blocked FOXO3 accumulation. Our experimental results strongly suggest that resveratrol treatment improves the beneficial effects of exercise training in aging rat hearts.
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Exercise training enhanced SIRT1 longevity signaling replaces the IGF1 survival pathway to attenuate aging-induced rat heart apoptosis.
Age (Dordr)
PUBLISHED: 08-23-2014
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Cardiovascular disease is the second leading cause of death (9.1 %) in Taiwan. Heart function deteriorates with age at a rate of 1 % per year. As society ages, we must study the serious problem of cardiovascular disease. SIRT1 regulates important cellular processes, including anti-apoptosis, neuronal protection, cellular senescence, aging, and longevity. In our previous studies, rats with obesity, high blood pressure, and diabetes exhibiting slowed myocardial performance and induced cell apoptosis were reversed via sports training through IGF1 survival signaling compensation. This study designed a set of experiments with rats, in aging and exercise groups, to identify changes in myocardial cell signaling transduction pathways. Three groups of three different aged rats, 3, 12, and 18 months old, were randomly divided into aging groups (C3, A12, and A18) and exercise groups (E3, AE12, and AE18). The exercise training consisted of swimming five times a week with gradual increases from the first week from 20 to 60 min for 12 weeks. After the sports training process was completed, tissue sections were taken to observe cell organization (hematoxylin and eosin (H&E) stain) and apoptosis (terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays) and to observe any changes in the myocardial tissues and proteins (Western blotting). The experimental results show that cardiomyocyte apoptotic pathway protein expression increased with age in the aging groups (C3, A12, and A18), with improvement in the exercise group (E3, AE12, and AE18). However, the expression of the pro-survival p-Akt protein decreased significantly with age and reduced performance. The IGF1R/PI3K/Akt survival pathway in the heart of young rats can indeed be increased through exercise training. As rats age, this pathway loses its original function, even with increasing upstream IGF1. However, levels of SIRT1 and its downstream target PGC-1? were found to increase with age and compensatory performance. Moreover, exercise training enhanced the SIRT longevity pathway compensation instead of IGF1 survival signaling to improve cardiomyocyte survival.
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The use of a well-defined surface organometallic complex as a probe molecule: [(?SiO)Ta(V)Cl2Me2] shows different isolated silanol sites on the silica surface.
Chem. Commun. (Camb.)
PUBLISHED: 08-22-2014
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Ta(V)Cl2Me3 reacts with silica(700) and produces two different [(?SiO)Ta(V)Cl2Me2] surface organometallic species, suggesting a heterogeneity of the highly dehydroxylated silica surface, which was studied with a combined experimental and theoretical approach.
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Trajectories of Sleep and Its Predictors in the First Year Following Traumatic Brain Injury.
J Head Trauma Rehabil
PUBLISHED: 08-12-2014
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To examine how sleep patterns change over the first year following traumatic brain injury (TBI) and to determine whether specific demographic and disease characteristics predict the trajectories of sleep.
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Applying T-cell receptor excision circles and immunoglobulin ?-deleting recombination excision circles to patients with primary immunodeficiency diseases.
Ann. Med.
PUBLISHED: 08-11-2014
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Abstract Background. Biomarkers of T-cell receptor excision circles (TRECs) and immunoglobulin ?-deleting recombination excision circles (KRECs) reflect naïve T and B cell emigrants. This study assessed the biomarkers in patients with primary immunodeficiency diseases (PIDs) to determine the lymphocyte output disturbance and the correlation to lymphocytes. Methods. A standard plasmid was constructed to calculate TRECs and KRECs in 250 ng genomic DNA from whole blood of PIDs patients. These were correlated to naïve and memory lymphocytes for further classification and adequate treatment. Results. In 69 studied patients, the low TRECs mainly included those with severe combined T and B immunodeficiency (SCID, 7/8), combined immunodeficiency (CID, 4/4), and common variable immunodeficiency (CVID, 6/7). The diminished KRECs was in SCID (4/8), CID (4/4), CVID (7/7), Bruton's tyrosine kinase mutation (Btk, 3/4), anti-B cell deletion (by anti-CD20 antibody in 1), and Behçet syndrome under steroid treatment (1). The TRECs and KRECs positively correlated to absolute naïve T (CD4 + CD45RA+) and naïve B (CD19 + CD27-), and to memory B (CD19 + CD27+) numbers, respectively. Conclusion. This study validates that low TRECs and KRECs values reflect low naïve T and B lymphocytes in 'combined immunodeficiencies' and in some CVID patients with the potential to develop the CID phenotype.
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Augmented cellular uptake of nanoparticles using tea catechins: effect of surface modification on nanoparticle-cell interaction.
Nanoscale
PUBLISHED: 07-29-2014
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Nanoparticles may serve as carriers in targeted therapeutics; interaction of the nanoparticles with a biological system may determine their targeting effects and therapeutic efficacy. Epigallocatechin-3-gallate (EGCG), a major component of tea catechins, has been conjugated with nanoparticles and tested as an anticancer agent. We investigated whether EGCG may enhance nanoparticle uptake by tumor cells. Cellular uptake of a dextran-coated magnetic nanoparticle (MNP) was determined by confocal microscopy, flow cytometry or a potassium thiocyanate colorimetric method. We demonstrated that EGCG greatly enhanced interaction and/or internalization of MNPs (with or without polyethylene glycol) by glioma cells, but not vascular endothelial cells. The enhancing effects are both time- and concentration-dependent. Such effects may be induced by a simple mix of MNPs with EGCG at a concentration as low as 1-3 ?M, which increased MNP uptake 2- to 7-fold. In addition, application of magnetic force further potentiated MNP uptake, suggesting a synergetic effect of EGCG and magnetic force. Because the effects of EGCG were preserved at 4 °C, but not when EGCG was removed from the culture medium prior to addition of MNPs, a direct interaction of EGCG and MNPs was implicated. Use of an MNP-EGCG composite produced by adsorption of EGCG and magnetic separation also led to an enhanced uptake. The results reveal a novel interaction of a food component and nanocarrier system, which may be potentially amenable to magnetofection, cell labeling/tracing, and targeted therapeutics.
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Characterization of four B-chromosome-specific RAPDs and the development of SCAR markers on the maize B-chromosome.
Mol. Genet. Genomics
PUBLISHED: 07-14-2014
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Understanding the molecular organization of the maize B-chromosome is hindered by its high homology with A-chromosomes. Recently, various approaches have been employed to overcome this hindrance, and several B-chromosome-specific sequences have been identified. Here, we cloned and characterized four previously published B-chromosome-specific RAPD fragments in detail. The results of sequence analysis, Southern hybridization and fluorescence in situ hybridization revealed that the four RAPD fragments are repetitive and present on both the B- and A-chromosomes, which supports an A-chromosome origin of the B-chromosome. We further developed four sequence-characterized amplified region (SCAR) markers derived from the four B-chromosome-specific RAPDs. These markers amplified PCR products exclusively in plants with B-chromosomes and were further mapped to definite distal heterochromatic regions of the B-chromosome by 15 B-A translocations. Furthermore, reverse transcriptase-PCR revealed that two of the four B-chromosome-specific RAPD fragments are transcriptionally active. These results demonstrate the feasibility of using B-chromosome-specific RAPD sequences to generate SCAR markers specific to the B-chromosome and might apply to other sequences of the maize B-chromosome.
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Stable 7,14-disubstituted-5,12-dithiapentacenes with quinoidal conjugation.
Org. Lett.
PUBLISHED: 07-14-2014
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Two 7,14-disubstituted-5,12-dithiapentacenes (1 and 2) with quinoidal conjugation were synthesized. Their ground-state quinoidal structures were proven by X-ray crystallographic analysis. They showed very different electronic and optical properties from those of the corresponding pentacene derivatives with diene conjugation, and their stability was significantly improved. Organic field effect transistors based on solution processed thin films of 1 and 2 exhibited a hole mobility of up to 0.032 cm(-2) V(-1) s(-1).
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Asymmetric NHC-catalyzed aza-Diels-Alder reactions: highly enantioselective route to ?-amino acid derivatives and DFT calculations.
Org. Lett.
PUBLISHED: 07-02-2014
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A facile N-heterocyclic carbene catalytic enantioselective aza-Diels-Alder reaction of oxodiazenes with ?-chloroaldehydes as dienophile precursors is reported, with excellent enantioselectivity (ee > 99%) and excellent yield (up to 93%). DFT study showed that cis-TSa, formed from a top face approach of oxodiazene to cis-IIa, is the most favorable transition state and is consistent with the experimental observations.
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Synthesis and characterization of bisoxazolines- and pybox-copper(II) complexes and their application in the coupling of ?-carbonyls with functionalized amines.
Org. Biomol. Chem.
PUBLISHED: 06-21-2014
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Binuclear complexes [{(DMOX)CuCl}2(?-Cl)2] (1), mononuclear complexes [(DMOX)CuBr2] (2) (DMOX = 4,5-dihydro-2-(4,5-dihydro-4,4-dimethyloxazol-2-yl)-4,4-dimethyloxazole) and the pybox Cu(II) complex [(Dm-Pybox)CuBr2] (3) (Dm-Pybox = 2,6-bis[4',4'-dimethyloxazolin-2'-yl]pyridine) were obtained by reactions of CuX2 (X = Cl, Br) with DMOX and Dm-Pybox ligands, respectively. The molecular structures of 1, 2 and 3 have been determined by single-crystal X-ray diffraction analyses. The complexes 2 and 3 are efficient in catalyzing ?-amination of ketones and esters through ?-bromo carbonyl intermediate. The procedures are environmentally benign methods using molecular oxygen as an oxidant with water as the only byproduct.
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A reusable magnetic graphene oxide-modified biosensor for vascular endothelial growth factor detection in cancer diagnosis.
Biosens Bioelectron
PUBLISHED: 06-05-2014
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Early cancer diagnosis is critical for the prevention of metastasis. However, simple and efficient methods are needed to improve the diagnosis and evaluation of cancer. Here, we propose a reusable biosensor based on a magnetic graphene oxide (MGO)-modified Au electrode to detect vascular endothelial growth factor (VEGF) in human plasma for cancer diagnosis. In this biosensor, Avastin is used as the specific biorecognition element, and MGO is used as the carrier for Avastin loading. The use of MGO enables rapid purification due to its magnetic properties, which prevents the loss of bioactivity. Moreover, the biosensor can be constructed quickly, without requiring a drying process, which is convenient for proceeding to detection. Our reusable biosensor provides the appropriate sensitivity for clinical diagnostics and has a wide range of linear detection, from 31.25-2000pgmL(-1), compared to ELISA analysis. In addition, in experiments with 100% serum from clinical samples, readouts from the sensor and an ELISA for VEGF showed good correlation within the limits of the ELISA kit. The relative standard deviation (RSD) of the change in current (?C) for reproducibility of the Au biosensor was 2.36% (n=50), indicating that it can be reused with high reproducibility. Furthermore, the advantages of the Avastin-MGO-modified biosensor for VEGF detection are that it provides an efficient detection strategy that not only improves the detection ability but also reduces the cost and decreases the response time by 10-fold, indicating its potential as a diagnosis product.
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Co-targeting of multiple microRNAs on factor-inhibiting hypoxia-inducible factor (FIH) gene for the pathogenesis of head and neck carcinomas.
Head Neck
PUBLISHED: 06-03-2014
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Background: MicroRNAs (miRNAs) are short, non-coding RNAs that inhibit the expression of target genes that play roles in tumorigenesis. miR-21, miR-31 and miR-184 are oncogenic miRNAs for head and neck squamous cell carcinoma (HNSCC). Factor-inhibiting hypoxia-inducible factor (FIH) is known to inactivate hypoxia induced downstream effectors and involved in HNSCC suppression. This study investigates whether miR-21, miR-31 and miR-184 target FIH in HNSCC. Methods: Reporter assays, Western blot analysis, quantitative reverse transcriptase-polymerase chain reaction analysis and phenotypic assays were used to prove that miR-21, miR-31 and miR-184 directly target FIH. Clinicopathological implications of the gene expression were also analyzed. Results: miR-21, miR-31 and miR-184 directly bind to various sites in the 3'UTR of FIH transcript, and this binding is associated with decreased FIH protein expression in HNSCC cells. Treatment with the precursors of these miRNAs increases the proliferation and migration of HNSCC cells. Concomitant treatment with precursors repressed FIH and enhanced oncogenicity most profoundly. Up-regulation of miR-21, miR-31 and miR-184 expression is found in more than 80% HNSCC tumors and 72% tumors have concordant up-regulation of these three oncogenic miRNAs. Highest expression of these miRNAs is present in T4b and Stage IVB tumors. Down-regulation of FIH mRNA expression is noted in 69% HNSCC tumors, and in tumors exhibiting high expression of these miRNAs, the FIH mRNA expression is consistently down-regulated. Conclusion: This study provides novel clues indicating that miR-21, miR-31 and miR-184 co-target FIH tumor suppressor during pathogenesis in the vast majority of HNSCC. Head Neck, 2014.
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Development of online diary and self-management system on e-Healthcare for asthmatic children in Taiwan.
Comput Methods Programs Biomed
PUBLISHED: 05-22-2014
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Many regional programs of the countries educate asthmatic children and their families to manage healthcare data. This study aims to establish a Web-based self-management system, eAsthmaCare, to promote the electronic healthcare (e-Healthcare) services for the asthmatic children in Taiwan. The platform can perform real time online functionality based upon a five-tier infrastructure with mutually supportive components to acquire asthma diaries, quality of life assessments and health educations.
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Serum 25-Hydroxyvitamin D Levels in Relation to Lung Function and Exhaled Nitric Oxide in Children.
J. Pediatr.
PUBLISHED: 05-09-2014
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To investigate the relationship of vitamin D status with lung function and fraction of exhaled nitric oxide (FeNO) in a population sample of children.
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Exclusive breastfeeding is associated with reduced cow's milk sensitization in early childhood.
Pediatr Allergy Immunol
PUBLISHED: 04-22-2014
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Although breastfed infants have consistently been reported as having fewer infections and respiratory morbidity during infancy, none have reached a definitive conclusion as to whether breastfeeding is an effective strategy to prevent allergic diseases. This study aims to investigate the relationship between exclusive breastfeeding and sequential changes of several biomarkers of allergy, such as absolute eosinophil count, total IgE level, and specific IgE level during the first 3 yrs of life.
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Comorbidities of pediatric systemic lupus erythematosus: A 6-year nationwide population-based study.
J Microbiol Immunol Infect
PUBLISHED: 04-14-2014
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Systemic lupus erythematous (SLE) is a systemic and complex disease that can involve multiple organs. To clarify the risk of developing associated comorbidities after a diagnosis of SLE in children, we used the National Health Insurance Research Database (NHIRD) in Taiwan to investigate diseases experienced in these patients. This is the first nationwide population-based study of the comorbidities of pediatric SLE patients.
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Protective effect of Danggui (Radix Angelicae Sinensis) on angiotensin II-induced apoptosis in H9c2 cardiomyoblast cells.
BMC Complement Altern Med
PUBLISHED: 04-11-2014
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Danggui (Radix Angelicae Sinensis) is an herb often used in Traditional Chinese medicine. It is used to promote blood flow and has been used in the treatment of myocardial ischemia-reperfusion injury in animal models. Angiotensin II (Ang II) has been shown to play important roles in mediating cardiovascular diseases, and may cause cardiac hypertrophy and apoptosis. This study aimed to investigate whether Danggui has protective effects on Ang II-induced apoptosis in H9c2 cardiomyoblast cells and study the mechanisms involved.
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para-Quinodimethane-bridged perylene dimers and pericondensed quaterrylenes: the effect of the fusion mode on the ground states and physical properties.
Chemistry
PUBLISHED: 03-29-2014
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Polycyclic hydrocarbon compounds with a singlet biradical ground state show unique physical properties and promising material applications; therefore, it is important to understand the fundamental structure/biradical character/physical properties relationships. In this study, para-quinodimethane (p-QDM)-bridged quinoidal perylene dimers 4 and 5 with different fusion modes and their corresponding aromatic counterparts, the pericondensed quaterrylenes 6 and 7, were synthesized. Their ground-state electronic structures and physical properties were studied by using various experiments assisted with DFT calculations. The proaromatic p-QDM-bridged perylene monoimide dimer 4 has a singlet biradical ground state with a small singlet/triplet energy gap (-2.97?kcal?mol(-1)), whereas the antiaromatic s-indacene-bridged N-annulated perylene dimer 5 exists as a closed-shell quinoid with an obvious intramolecular charge-transfer character. Both of these dimers showed shorter singlet excited-state lifetimes, larger two-photon-absorption cross sections, and smaller energy gaps than the corresponding aromatic quaterrylene derivatives 6 and 7, respectively. Our studies revealed how the fusion mode and aromaticity affect the ground state and, consequently, the photophysical properties and electronic properties of a series of extended polycyclic hydrocarbon compounds.
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Correlation of ovalbumin of egg white components with allergic diseases in children.
J Microbiol Immunol Infect
PUBLISHED: 03-26-2014
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Immunoglobulin E (IgE)-mediated food allergy, such as egg white allergy, is common in young children (<3 years old), but not all young children sensitive to egg white present with allergic symptoms. This study investigated the relationship between sensitization to egg white component allergens and clinical manifestations of allergic diseases in young children.
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Design and experimental evaluation of a 256-channel dual-frequency ultrasound phased-array system for transcranial blood-brain barrier opening and brain drug delivery.
IEEE Trans Biomed Eng
PUBLISHED: 03-25-2014
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Focused ultrasound (FUS) in the presence of microbubbles can bring about transcranial and local opening of the blood-brain barrier (BBB) for potential noninvasive delivery of drugs to the brain. A phased-array ultrasound system is essential for FUS-BBB opening to enable electronic steering and correction of the focal beam which is distorted by cranial bone. Here, we demonstrate our prototype design of a 256-channel ultrasound phased-array system for large-region transcranial BBB opening in the brains of large animals. One of the unique features of this system is the capability of generating concurrent dual-frequency ultrasound signals from the driving system for potential enhancement of BBB opening. A wide range of signal frequencies can be generated (frequency = 0.2-1.2 MHz) with controllable driving burst patterns. Precise output power can be controlled for individual channels via 8-bit duty-cycle control of transistor-transistor logic signals and the 8-bit microcontroller-controlled buck converter power supply output voltage. The prototype system was found to be in compliance with the electromagnetic compatibility standard. Moreover, large animal experiments confirmed the phase switching effectiveness of this system, and induction of either a precise spot or large region of BBB opening through fast focal-beam switching. We also demonstrated the capability of dual-frequency exposure to potentially enhance the BBB-opening effect. This study contributes to the design of ultrasound phased arrays for future clinical applications, and provides a new direction toward optimizing FUS brain drug delivery.
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Catalytic mechanisms of direct pyrrole synthesis via dehydrogenative coupling mediated by PNP-Ir or PNN-Ru pincer complexes: crucial role of proton-transfer shuttles in the PNP-Ir system.
J. Am. Chem. Soc.
PUBLISHED: 03-24-2014
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Kempe et al. and Milstein et al. have recently advanced the dehydrogenative coupling methodology to synthesize pyrroles from secondary alcohols (e.g., 3) and ?-amino alcohols (e.g., 4), using PNP-Ir (1) and PNN-Ru (2) pincer complexes, respectively. We herein present a DFT study to characterize the catalytic mechanism of these reactions. After precatalyst activation to give active 1A/2A, the transformation proceeds via four stages: 1A/2A-catalyzed alcohol (3) dehydrogenation to give ketone (11), base-facilitated C-N coupling of 11 and 4 to form an imine-alcohol intermediate (18), base-promoted cyclization of 18, and catalyst regeneration via H2 release from 1R/2R. For alcohol dehydrogenations, the bifunctional double hydrogen-transfer pathway is more favorable than that via ?-hydride elimination. Generally, proton-transfer (H-transfer) shuttles facilitate various H-transfer processes in both systems. Notwithstanding, H-transfer shuttles play a much more crucial role in the PNP-Ir system than in the PNN-Ru system. Without H-transfer shuttles, the key barriers up to 45.9 kcal/mol in PNP-Ir system are too high to be accessible, while the corresponding barriers (<32.0 kcal/mol) in PNN-Ru system are not unreachable. Another significant difference between the two systems is that the addition of alcohol to 1A giving an alkoxo complex is endergonic by 8.1 kcal/mol, whereas the addition to 2A is exergonic by 8.9 kcal/mol. The thermodynamic difference could be the main reason for PNP-Ir system requiring lower catalyst loading than the PNN-Ru system. We discuss how the differences are resulted in terms of electronic and geometric structures of the catalysts and how to use the features in catalyst development.
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Magnetic-resonance imaging for kinetic analysis of permeability changes during focused ultrasound-induced blood-brain barrier opening and brain drug delivery.
J Control Release
PUBLISHED: 03-13-2014
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Focused ultrasound (FUS) with the presence of microbubbles has been shown to induce transient and local opening of the blood-brain barrier (BBB) for the delivery of therapeutic molecules which normally cannot penetrate into the brain. The success of FUS brain-drug delivery relies on its integration with in-vivo imaging to monitor kinetic change of therapeutic molecules into the brain. In this study, we developed a dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) technique for kinetic analysis of delivered molecules during FUS-BBB opening. Three kinetic parameters (Ktrans, Ve, Kep) were characterized dynamically to describe BBB-permeability at two FUS exposure conditions (0.4 or 0.8MPa) over 24h. Ktrans, defined as the influx volume transfer constant from plasma to EES, and Ve, the EES volume fraction, were both found to be pressure-dependent. Ktrans and Ve showed a peak increase of 0.0086-0.0131min(-1) (for 0.4-0.8MPa pressure), and 0.0431-0.0692, respectively, immediately after FUS exposure. Both parameters subsequently decreased exponentially as a function of time, with estimated half-lives of decay of 2.89-5.3 and 2.2-4.93h, respectively. The kinetics of Kep, defined as the efflux rate constant from the extracellular extravascular space (EES) to the plasma, were complementary to Ktrans, with an initial decrease from 0.2010 to 0.1901min(-1) followed by a significantly longer recovery time (half-life of 17.39-99.92h). Our observations strongly supported the existence of imbalanced and mismatched kinetics of influx (Ktrans) and efflux (Kep) between the plasma and EES, indicating the existence of directional permeability during FUS-BBB opening. We further showed that kinetic change determined by DCE-MRI correlated well with the concentration of Evans Blue (EB)-albumin (coefficient of 0.74-0.89). These findings suggest that MRI kinetic monitoring may serve as an alternative method for in-vivo monitoring of pharmacokinetics and pharmacodynamics (PK/PD) change of therapeutic agents during drug delivery to the brain, and provide useful information for future optimization of FUS-BBB opening.
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Gadolinium-functionalized nanographene oxide for combined drug and microRNA delivery and magnetic resonance imaging.
Biomaterials
PUBLISHED: 03-13-2014
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The delivery of anti-cancer therapeutics to tumors at clinically effective concentrations, while avoiding nonspecific toxicity, remains a major challenge for cancer treatment. Here we present nanoparticles of poly(amidoamine) dendrimer-grafted gadolinium-functionalized nanographene oxide (Gd-NGO) as effective carriers to deliver both chemotherapeutic drugs and highly specific gene-targeting agents such as microRNAs (miRNAs) to cancer cells. The positively charged surface of Gd-NGO was capable of simultaneous adsorption of the anti-cancer drug epirubicin (EPI) and interaction with negatively charged Let-7g miRNA. Using human glioblastoma (U87) cells as a model, we found that this conjugate of Let-7g and EPI (Gd-NGO/Let-7g/EPI) not only exhibited considerably higher transfection efficiency, but also induced better inhibition of cancer cell growth than Gd-NGO/Let-7g or Gd-NGO/EPI. The concentration of Gd-NGO/Let-7g/EPI required for 50% inhibition of cellular growth (IC50) was significantly reduced (to the equivalent of 1.3 ?g/mL EPI) compared to Gd-NGO/EPI (3.4 ?g/mL EPI). In addition, Gd-NGO/Let-7g/EPI could be used as a contrast agent for magnetic resonance imaging to identify the location and extent of blood-brain barrier opening and quantitate drug delivery to tumor tissues. These results suggest that Gd-NGO/Let-7g/EPI may be a promising non-viral vector for chemogene therapy and molecular imaging diagnosis in future clinical applications.
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Thermal- and photo-induced phase-transition behaviors of a tapered dendritic liquid crystal with photochromic azobenzene mesogens and a bicyclic chiral center.
Chemistry
PUBLISHED: 02-10-2014
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A ribbon-shaped chiral liquid crystalline (LC) dendrimer with photochromic azobenzene mesogens and an isosorbide chiral center (abbreviated as AZ3 DLC) was successfully synthesized and its major phase transitions were studied by using differential scanning calorimetry (DSC) and linear polarized optical microscopy (POM). Its ordered structures at different temperatures were further identified through structure-sensitive diffraction techniques. Based on the experimental results, it was found that the AZ3 DLC molecule exhibited the low-ordered chiral smectic (Sm*) LC phase with 6.31?nm periodicity at a high-temperature phase region. AZ3 DLC showed the reversible photoisomerization in both organic solvents and nematic (N) LC media. As a chiral-inducing agent, it exhibited a good solubility, a high helical-twisting power, and a large change in the helical-twisting power due to its photochemical isomerization in the commercially available N LC hosts. Therefore, we were able to reversibly "remote-control" the colors in the whole visible region by finely tuning the helical pitch of the spontaneously formed helical superstructures.
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Adult supratentorial extra-pineal primitive neuro-ectodermal tumors.
J Clin Neurosci
PUBLISHED: 01-28-2014
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Primitive neuro-ectodermal tumors (PNET) are rare malignant brain tumors, mostly undifferentiated, that tend to spread through the cerebrospinal fluid (CSF). Extra-pineal supratentorial PNET in adults are very rare. Published guidelines for adult PNET were not available until 2011, and at our institute surgeons and oncologists did not have consensus on imaging evaluation or treatment protocols between 1994 to 2008. Twenty-two consecutive adult patients with extra-pineal supratentorial PNET from this period were reviewed in this retrospective study. Their clinical profiles and radiologic images were evaluated. A pathological review based on the 2007 World Health Organization criteria was also conducted. Prognostic factors were analyzed. The 1 and 3 year overall survival rates were 64% and 32% for adult extra-pineal supratentorial PNET, respectively. Limited by the small number of tumors in this series, we suggest that negative prognostic factors are multiplicity at onset, initial CSF seeding, and tumor differentiation. Although age of onset, extent of resection, radiation and chemotherapy were assumed to be good prognostic factors, the analysis did not reveal strong significance for overall survival with univariate and multivariate analysis. We believe more detailed investigations on the genetic/molecular basis of supratentorial PNET and their clinical outcomes are warranted.
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meso-Ester and carboxylic acid substituted BODIPYs with far-red and near-infrared emission for bioimaging applications.
Chemistry
PUBLISHED: 01-21-2014
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A series of meso-ester-substituted BODIPY derivatives 1-6 are synthesized and characterized. In particular, dyes functionalized with oligo(ethylene glycol) ether styryl or naphthalene vinylene groups at the ? positions of the BODIPY core (3-6) become partially soluble in water, and their absorptions and emissions are located in the far-red or near-infrared region. Three synthetic approaches are attempted to access the meso-carboxylic acid (COOH)-substituted BODIPYs 7 and 8 from the meso-ester-substituted BODIPYs. Two feasible synthetic routes are developed successfully, including one short route with only three steps. The meso-COOH-substituted BODIPY 7 is completely soluble in pure water, and its fluorescence maximum reaches around 650?nm with a fluorescence quantum yield of up to 15?%. Time-dependent density functional theory calculations are conducted to understand the structure-optical properties relationship, and it is revealed that the Stokes shift is dependent mainly on the geometric change from the ground state to the first excited singlet state. Furthermore, cell staining tests demonstrate that the meso-ester-substituted BODIPYs (1 and 3-6) and one of the meso-COOH-substituted BODIPYs (8) are very membrane-permeable. These features make these meso-ester- and meso-COOH-substituted BODIPY dyes attractive for bioimaging and biolabeling applications in living cells.
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Differentiation of Brain Abscesses from Glioblastomas and Metastatic Brain Tumors: Comparisons of Diagnostic Performance of Dynamic Susceptibility Contrast-Enhanced Perfusion MR Imaging before and after Mathematic Contrast Leakage Correction.
PLoS ONE
PUBLISHED: 01-01-2014
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To compare the diagnostic performance of dynamic susceptibility contrast-enhanced perfusion MRI before and after mathematic contrast leakage correction in differentiating pyogenic brain abscesses from glioblastomas and/or metastatic brain tumors.
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Transglutaminase 2 expression is increased as a function of malignancy grade and negatively regulates cell growth in meningioma.
PLoS ONE
PUBLISHED: 01-01-2014
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Most meningiomas are benign, but some clinical-aggressive tumors exhibit brain invasion and cannot be resected without significant complications. To identify molecular markers for these clinically-aggressive meningiomas, we performed microarray analyses on 24 primary cultures from 21 meningiomas and 3 arachnoid membranes. Using this approach, increased transglutaminase 2 (TGM2) expression was observed, which was subsequently validated in an independent set of 82 meningiomas by immunohistochemistry. Importantly, the TGM2 expression level was associated with increasing WHO malignancy grade as well as meningioma recurrence. Inhibition of TGM2 function by siRNA or cystamine induced meningioma cell death, which was associated with reduced AKT phosphorylation and caspase-3 activation. Collectively, these findings suggest that TGM2 expression increases as a function of malignancy grade and tumor recurrence and that inhibition of TGM2 reduces meningioma cell growth.
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Sensitization to food and inhalant allergens in relation to atopic diseases in early childhood: a birth cohort study.
PLoS ONE
PUBLISHED: 01-01-2014
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A correct interpretation of sensitization to common allergens is critical in determining susceptibility to allergic diseases. The aim of this study was to investigate the patterns of sensitization to food and inhalant allergens, and their relation to the development of atopic diseases in early childhood.
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Suboptimal vitamin D status in a population-based study of Asian children: prevalence and relation to allergic diseases and atopy.
PLoS ONE
PUBLISHED: 01-01-2014
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New evidence shows high prevalence of vitamin D deficiency in many countries and some studies suggest a possible link between vitamin D status and allergic diseases. The objectives of this study were to determine the prevalence of suboptimal vitamin D status in a population sample of Asian children and to investigate the relationship of vitamin D status with allergic diseases and atopy.
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Submicron-bubble-enhanced focused ultrasound for blood-brain barrier disruption and improved CNS drug delivery.
PLoS ONE
PUBLISHED: 01-01-2014
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The use of focused ultrasound (FUS) with microbubbles has been proven to induce transient blood-brain barrier opening (BBB-opening). However, FUS-induced inertial cavitation of microbubbles can also result in erythrocyte extravasations. Here we investigated whether induction of submicron bubbles to oscillate at their resonant frequency would reduce inertial cavitation during BBB-opening and thereby eliminate erythrocyte extravasations in a rat brain model. FUS was delivered with acoustic pressures of 0.1-4.5 MPa using either in-house manufactured submicron bubbles or standard SonoVue microbubbles. Wideband and subharmonic emissions from bubbles were used to quantify inertial and stable cavitation, respectively. Erythrocyte extravasations were evaluated by in vivo post-treatment magnetic resonance susceptibility-weighted imaging, and finally by histological confirmation. We found that excitation of submicron bubbles with resonant frequency-matched FUS (10 MHz) can greatly limit inertial cavitation while enhancing stable cavitation. The BBB-opening was mainly caused by stable cavitation, whereas the erythrocyte extravasation was closely correlated with inertial cavitation. Our technique allows extensive reduction of inertial cavitation to induce safe BBB-opening. Furthermore, the safety issue of BBB-opening was not compromised by prolonging FUS exposure time, and the local drug concentrations in the brain tissues were significantly improved to 60 times (BCNU; 18.6 µg versus 0.3 µg) by using chemotherapeutic agent-loaded submicron bubbles with FUS. This study provides important information towards the goal of successfully translating FUS brain drug delivery into clinical use.
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Lipid profiles alter from pro-atherogenic into less atherogenic and proinflammatory in juvenile idiopathic arthritis patients responding to anti TNF-? treatment.
PLoS ONE
PUBLISHED: 01-01-2014
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Dyslipidemia with higher inflammatory states, disease activity, and longer disease duration in juvenile idiopathic arthritis (JIA) patients seemed to increase the risks of atherosclerosis. Tumor necrosis factor- ? (TNF-?) receptor blocking agent etanercept has been proven to be effective in JIA. However, data about the correlation of anti-inflammatory treatment on lipid profiles and atherogenic index in JIA patients remains limited. This study aimed to investigate the longitudinal changes on lipid profiles and atherogenic index in JIA patients after etanercept treatment.
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N-Annulated Perylene as An Efficient Electron Donor for Porphyrin-Based Dyes: Enhanced Light-Harvesting Ability and High-Efficiency Co(II/III)-Based Dye-Sensitized Solar Cells.
J. Am. Chem. Soc.
PUBLISHED: 12-24-2013
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Porphyrin-based dyes recently have become good candidates for dye-sensitized solar cells (DSCs). However, the bottleneck is how to further improve their light-harvesting ability. In this work, N-annulated perylene (NP) was used to functionalize the Zn-porphyrin, and four "push-pull"-type NP-substituted and fused porphyrin dyes with intense absorption in the visible and even in the near-infrared (NIR) region were synthesized. Co(II/III)-based DSC device characterizations revealed that dyes WW-5 and WW-6, in which an ethynylene spacer is incorporated between the NP and porphyrin core, showed pantochromatic photon-to-current conversion efficiency action spectra in the visible and NIR region, with a further red-shift of about 90 and 60 nm, respectively, compared to the benchmark molecule YD2-o-C8. As a result, the short-circuit current density was largely increased, and the devices displayed power conversion efficiencies as high as 10.3% and 10.5%, respectively, which is comparable to that of the YD2-o-C8 cell (? = 10.5%) under the same conditions. On the other hand, the dye WW-3 in which the NP unit is directly attached to the porphyrin core showed a moderate power conversion efficiency (? = 5.6%) due to the inefficient ?-conjugation, and the NP-fused dye WW-4 exhibited even poorer performance due to its low-lying LUMO energy level and nondisjointed HOMO/LUMO profile. Our detailed physical measurements (optical and electrochemical), density functional theory calculations, and photovoltaic characterizations disclosed that the energy level alignment, the molecular orbital profile, and dye aggregation all played very important roles on the interface electron transfer and charge recombination kinetics.
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Dibenzoheptazethrene Isomers with Different Biradical Characters: An Exercise of Clars Aromatic Sextet Rule in Singlet Biradicaloids.
J. Am. Chem. Soc.
PUBLISHED: 11-20-2013
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Clars aromatic sextet rule has been widely used for the prediction of the reactivity and stability of polycyclic aromatic hydrocarbons with a closed-shell electronic configuration. Recent advances in open-shell biradicaloids have shown that the number of aromatic sextet rings plays an important role in determination of their ground states. In order to test the validity of this rule in singlet biradicaloids, the two soluble and stable dibenzoheptazethrene isomers DBHZ1 and DBHZ2 were prepared by different synthetic approaches and isolated in crystalline form. These two molecules have different numbers of aromatic sextet rings in their respective biradical resonance forms and thus are expected to exhibit varied singlet biradical character. This assumption was verified by different experimental methods, including nuclear magnetic resonance (NMR), electron spin resonance (ESR), superconducting quantum interference device (SQUID), steady-state and transient absorption spectroscopy (TA), and X-ray crystallographic analysis, assisted by unrestricted symmetry-broken density functional theory (DFT) calculations. DBHZ2, with more aromatic sextet rings in the biradical form, was demonstrated to possess greater biradical character than DBHZ1; as a result, DBHZ2 exhibited an intense one-photon absorption (OPA) in the near-infrared region (?abs(max) = 804 nm) and a large two-photon absorption (TPA) cross-section (?((2))max = 2800 GM at 1600 nm). This investigation together with previous studies indicates that Clars aromatic sextet rule can be further extended to the singlet biradicaloids to predict their ground states and singlet biradical characters.
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Bipodal Surface Organometallic Complexes with Surface N-Donor Ligands and Application to the Catalytic Cleavage of C-H and C-C Bonds in n-Butane.
J. Am. Chem. Soc.
PUBLISHED: 11-14-2013
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We present a new generation of "true vicinal" functions well-distributed on the inner surface of SBA15: [(?Si-NH2)(?Si-OH)] (1) and [(?Si-NH2)2] (2). From these amine-modified SBA15s, two new well-defined surface organometallic species [(?Si-NH-)(?Si-O-)]Zr(CH2tBu)2 (3) and [(?Si-NH-)2]Zr(CH2tBu)2 (4) have been obtained by reaction with Zr(CH2tBu)4. The surfaces were characterized with 2D multiple-quantum (1)H-(1)H NMR and infrared spectroscopies. Energy-filtered transmission electron microscopy (EFTEM), mass balance, and elemental analysis unambiguously proved that Zr(CH2tBu)4 reacts with these vicinal amine-modified surfaces to give mainly bipodal bis(neopentyl)zirconium complexes (3) and (4), uniformly distributed in the channels of SBA15. (3) and (4) react with hydrogen to give the homologous hydrides (5) and (6). Hydrogenolysis of n-butane catalyzed by these hydrides was carried out at low temperature (100 °C) and low pressure (1 atm). While (6) exhibits a bis(silylamido)zirconium bishydride, [(?Si-NH-)2]Zr(H)2 (6a) (60%), and a bis(silylamido)silyloxozirconium monohydride, [(?Si-NH-)2(?Si-O-)]ZrH (6b) (40%), (5) displays a new surface organometallic complex characterized by an (1)H NMR signal at 14.46 ppm. The latter is assigned to a (silylimido)(silyloxo)zirconium monohydride, [(?Si-N?)(?Si-O-)]ZrH (5b) (30%), coexistent with a (silylamido)(silyloxo)zirconium bishydride, [(?Si-NH-)(?Si-O-)]Zr(H)2 (5a) (45%), and a silylamidobis(silyloxo)zirconium monohydride, [(?Si-NH-)(?Si-O-)2]ZrH (5c) (25%). Surprisingly, nitrogen surface ligands possess catalytic properties already encountered with silicon oxide surfaces, but interestingly, catalyst (5) with chelating [N,O] shows better activity than (6) with chelating [N,N].
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TCNQ-embedded heptacene and nonacene: synthesis, characterization and physical properties.
Org. Biomol. Chem.
PUBLISHED: 08-15-2013
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Incorporation of 7,7,8,8-tetracyanoquinodimethane (TCNQ) moieties into the acene backbone has been successfully achieved and two heptacene-TCNQ derivatives and one nonacene-TCNQ derivative have been synthesized and well characterized. Two TCNQ moieties have been embedded into heptacene and nonacene backbones for the first time. All the three compounds have good stability and solubility due to the presence of TCNQ moieties. Single crystal analysis revealed a bent butterfly-like conformation of these molecules. Their charge transport properties have been characterized using organic field effect transistors (OFETs).
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Kinetic evidence of an apparent negative activation enthalpy in an organocatalytic process.
Sci Rep
PUBLISHED: 08-14-2013
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A combined kinetic and computational study on our tryptophan-based bifunctional thiourea catalyzed asymmetric Mannich reactions reveals an apparent negative activation enthalpy. The formation of the pre-transition state complex has been unambiguously confirmed and these observations provide an experimental support for the formation of multiple hydrogen bonding network between the substrates and the catalyst. Such interactions allow the creation of a binding cavity, a key factor to install high enantioselectivity.
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Tubercular temporalis abscess with skull and dural invasion.
Surg Infect (Larchmt)
PUBLISHED: 08-09-2013
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Mycobacterium tuberculosis infection rarely penetrates both skull and dura with temporalis muscle abscess formation.
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Donor-Derived Cryptococcus Infection in Liver Transplant: Case Report and Literature Review.
Exp Clin Transplant
PUBLISHED: 07-30-2013
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Cryptococcosis occurring within 30 days after transplant is unusual. We present a case of cryptococcosis diagnosed within 2 weeks of liver transplant and cryptococcal infection transmitted by liver transplant is considered as the cause. A 63-year-old woman with hepatitis C virus-related cirrhosis and hepatocellular carcinoma had an orthotopic liver transplant from a 45-year-old donor. The immediate postoperative course was smooth, although she was confused with a fever, tachycardia, respiratory failure of 1 weeks duration after the orthotopic liver transplant. A liver biopsy was performed for hyperbilirubinemia 2 weeks after the orthotopic liver transplant that showed a Cryptococcus-like yeast. Her blood culture was re-examined, and it was confirmed as Cryptococcus neoformans that had been misinterpreted as candida initially. At the time of the re-examination, her sputum was clear. We checked her preoperative blood sample, retrospectively, for serum cryptococcal antigen with negative result. She was on liposomal amphotericin treatment for 1 month when her blood culture became negative. She was discharged home, with good liver function and a low antigen titer for cryptococcal infection. Cryptococcal disease usually develops at a mean of 5.6 months after transplant. However an early occurrence is rare. Apart from that, its variable clinical presentations make early detection difficult. It might be an early reactivation or a donor-derived infection. The latter usually occurs in unusual sites (eg, the transplanted organ as the sole site of involvement). Our case presented as cryptococcoma and liver involvement was diagnosed by an unintentional liver biopsy.
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Anti-apoptotic and pro-survival effect of protocatechuic acid on hypertensive hearts.
Chem. Biol. Interact.
PUBLISHED: 07-27-2013
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Cardiac apoptosis was found in hearts from hypertensive animals, therefore in this study we aimed to evaluate the anti-apoptotic and pro-survival effects of protocatechuic acid (PCA) on hypertensive hearts. At first we found that, sedentary group (SHR)-PCA groups decreased TUNEL-positive apoptotic cells than SHR group alone. Protein levels of Fas ligand, Fas death receptor, Fas-associated death domain (FADD), Bid, t-Bid, Bax, cytochrome c, activated caspase-8, activated caspase 9 and activated caspase-3 were decreased in SHR-PCA group compared with SHR group. Moreover, SHR-PCA groups increased pro-survival pathway proteins like IGF1, pIGF1R, pPI3K, p-Akt, Bcl-xL, and Bcl-2 than SHR and sedentary normotensive group (WKY). All these finding suggest us that, Protocatechuic acid prevented hypertension-enhanced cardiac Fas-dependent and mitochondria-dependent apoptotic pathways and enhanced cardiac pro-survival pathway in rat models.
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Bisacenaphthopyrazinoquinoxaline derivatives: synthesis, physical properties and applications as semiconductors for n-channel field effect transistors.
Org. Biomol. Chem.
PUBLISHED: 07-26-2013
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Several bisacenaphthopyrazinoquinoxaline (BAPQ) based derivatives 1-3 were synthesized by condensation between the acenaphthenequinones and 1,2,4,5-tetraaminobenzene tetrahydrochloride. Their optical, electrochemical and self-assembling properties are tuned by different substituents. Among them, compound 3 possesses a homogeneously distributed low-lying LUMO due to the peripheral substitution with four cyano groups. The corresponding n-channel field effect transistors showed a field effect electron mobility of 5 × 10(-3) cm(2) V(-1) s(-1).
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Microfluidic integrated optoelectronic tweezers for single-cell preparation and analysis.
Lab Chip
PUBLISHED: 07-26-2013
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We report a novel microfluidic integrated optoelectronic tweezers (OET) platform for single-cell sample preparation and analysis. Integration of OET and microfluidics is achieved by embedding single-wall carbon nanotube (SWNT) electrodes into multilayer PDMS structures. This integrated platform allows users to selectively pick up individual cells from a population with light beams based on their optical signatures such as size, shape, and fluorescence, and transport them into isolated chambers using light induced dielectrophoretic forces. Isolated cells can be encapsulated into nanoliter liquid plugs and transported out of the platform for downstream molecule analysis using standard commercial instruments.
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From random coil polymers to helical structures induced by carbon nanotubes and supramolecular interactions.
Macromol Rapid Commun
PUBLISHED: 07-11-2013
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A simple method is reported for the preparation of double-helical structures through a series of achiral random and block copolymers poly(styrene-co-4-vinylbenzyl triazolylmethyl methylthymine) (PS-co-PVBT) with various T units on the side chains through click reactions of poly(styrene-co-4-vinylbenzyl azide) (PS-co-PVBN(3)) with propargyl thymine (PT) and also the synthesis of the A-appended pyrene derivative (A-Py) through click chemistry. This double-helical structure is observed from achiral random-coil polystyrene (PS) main chains, stabilized through the combination of multiple A-T hydrogen bonds, and ?-? stacking between pyrene units and single-walled carbon nanotubes (SWCNTs).
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Probiotic-fermented purple sweet potato yogurt activates compensatory IGF?IR/PI3K/Akt survival pathways and attenuates cardiac apoptosis in the hearts of spontaneously hypertensive rats.
Int. J. Mol. Med.
PUBLISHED: 07-09-2013
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Apoptosis is recognized as a predictor of adverse outcomes in subjects with cardiac diseases. The aim of this study was to explore the effects of probiotic-fermented purple sweet potato yogurt (PSPY) with high ?-aminobutyric acid (GABA) content on cardiac apoptosis in spontaneously hypertensive rat (SHR) hearts. The rats were orally adminsitered with 2 different concentrations of PSPY (10 and 100%) or captopril, 15.6 mg/kg, body weight (BW)/day. The control group was administered distilled water. DAPI and TUNEL staining were used to detect the numbers of apoptotic cells. A decrease in the number of TUNEL-positive cardiac myocytes was observed in the SHR-PSPY (10 and 100%) groups. In addition, the levels of key components of the Fas receptor- and mitochondrial-dependent apoptotic pathways were determined by western blot analysis. The results revealed that the levels of the key components of the Fas receptor- and mitochondrial-dependent apoptotic pathway were significantly decreased in the SHR-captopril, and 10 and 100% PSPY groups. Additionally, the levels of phosphorylated insulin-like growth factor?I receptor (p-IGF?IR) were increased in SHR hearts from the SHR-control group; however, no recovery in the levels of downstream signaling components was observed. In addition, the levels of components of the compensatory IGF-IR-dependent survival pathway (p-PI3K and p-Akt) were all highly enhanced in the left ventricles in the hearts form the SHR-10 and 100% PSPY groups. Therefore, the oral administration of PSPY may attenuate cardiomyocyte apoptosis in SHR hearts by activating IGF?IR-dependent survival signaling pathways.
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Molecular dynamics simulations on gate opening in ZIF-8: identification of factors for ethane and propane separation.
Langmuir
PUBLISHED: 06-28-2013
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Gate opening of zeolitic imidazolate frameworks (ZIFs) is an important microscopic phenomenon in explaining the adsorption, diffusion, and separation processes for large guest molecules. We present a force field, with input from density functional theory (DFT) calculations, for the molecular dynamics simulation on the gate opening in ZIF-8. The computed self-diffusivities for sorbed C1 to C3 hydrocarbons were in good agreement with the experimental values. The observed sharp diffusion separation from C2H6 to C3H8 was elucidated by investigating the conformations of the guest molecules integrated with the flexibility of the host framework.
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The origin of enantioselectivity in the L-threonine-derived phosphine-sulfonamide catalyzed aza-Morita-Baylis-Hillman reaction: effects of the intramolecular hydrogen bonding.
Org. Biomol. Chem.
PUBLISHED: 06-17-2013
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L-Threonine-derived phosphine-sulfonamide 4 was identified as the most efficient catalyst to promote enantioselective aza-Morita-Baylis-Hillman (MBH) reactions, affording the desired aza-MBH adducts with excellent enantioselectivities. Density functional theory (DFT) studies were carried out to elucidate the origin of the observed enantioselectivity. The importance of the intramolecular N-H···O hydrogen-bonding interaction between the sulfonamide and enolate groups was identified to be crucial in inducing a high degree of stereochemical control in both the enolate addition to imine and the subsequent proton transfer step, affording aza-MBH reactions with excellent enantioselectivity.
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Tunable mesoporous lamellar silicas prepared using poly(ethylene oxide-b-L-lactide) and poly(ethylene-b-ethylene oxide-b-L-lactide) block copolymers as templates.
J Nanosci Nanotechnol
PUBLISHED: 06-15-2013
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In this study, we synthesized poly(ethylene oxide-b-L-lactide) (PEO-PLLA) diblock copolymers and poly(ethylene-b-ethylene oxide-b-L-lactide) (PE-PEO-PLLA) triblock terpolymers as templates for the preparation of mesoporous lamellar silicas, possessing single, bimodal, or trimodal pore size distributions, through an evaporation-induced self-assembly (EISA) approach. As templates, we synthesized the diblock copolymers EO114LLA26 and EO114LLA130 and the triblock terpolymers E13EO42LLA26 and E13EO42LLA35 using simple ring-opening polymerization. Small-angle X-ray scattering, transmission electron microscopy, and N2 sorption measurements revealed that the mesoporous silicas displayed the morphologies of either lamellar silica walls featuring a distribution of many short cylindrical mesopores or pure lamellar structures. The morphology was greatly affected by the nature of the template (diblock or triblock copolymer) and the molecular weight of the PLLA segment in the block copolymer.
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Quantification of tumor necrosis factor-? and matrix metalloproteinases-3 in synovial fluid by a fiber-optic particle plasmon resonance sensor.
Analyst
PUBLISHED: 06-12-2013
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The availability of techniques for sensitive detection of early stage osteoarthritis is critical for improving patient health. This study illustrates the feasibility of a fiber-optic particle plasmon resonance (FOPPR) sensor with gold nanoparticles on the unclad region of optical fiber probes for analysis of osteoarthritis biomarkers, tumor necrosis factor-? (TNF-?) and matrix metalloproteinases-3 (MMP-3). Results show that the sensor can achieve a refractive index resolution of 5.18 × 10?? RIU and limits of detection for TNF-? and MMP-3 as low as 8.22 pg ml?¹ (0.48 pM) and 34.3 pg ml?¹ (1.56 pM), respectively. Additionally, the FOPPR sensor shows a good correlation in determining TNF-? and MMP-3 in synovial fluid with the clinically accepted enzyme-linked immunosorbent assay (ELISA) method. Finally, given the FOPPR sensors nature of being low-cost, label-free, highly sensitive, real-time, simple-to-operate, the FOPPR sensor could offer potential to monitor biomarkers of various diseases, and provide an ideal technical tool for point-of-care diagnostics.
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Interactive support interventions for caregivers of asthmatic children.
J Asthma
PUBLISHED: 05-13-2013
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Asthmatic children and their parents constantly need to adjust their lifestyles due to asthma attacks. We evaluated the effectiveness of a self-management interactive support (SMIS) program for caregivers of asthmatic children.
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Optoelectronic tweezers integrated with lensfree holographic microscopy for wide-field interactive cell and particle manipulation on a chip.
Lab Chip
PUBLISHED: 05-09-2013
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We demonstrate an optoelectronic tweezer (OET) coupled to a lensfree holographic microscope for real-time interactive manipulation of cells and micro-particles over a large field-of-view (FOV). This integrated platform can record the holographic images of cells and particles over the entire active area of a CCD sensor array, perform digital image reconstruction to identify target cells, dynamically track the positions of cells and particles, and project light beams to trigger light-induced dielectrophoretic forces to pattern and sort cells on a chip. OET technology has been previously shown to be capable of performing parallel single cell manipulation over a large area. However, its throughput has been bottlenecked by the number of cells that can be imaged within the limited FOV of a conventional microscope objective lens. Integrating lensfree holographic imaging with OET solves this fundamental FOV barrier, while also creating a compact on-chip cell/particle manipulation platform. Using this unique platform, we have successfully demonstrated real-time interactive manipulation of thousands of single cells and micro-particles over an ultra-large area of e.g., 240 mm(2) (i.e. 17.96 mm × 13.52 mm).
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GABA Tea Prevents Cardiac Fibrosis by Attenuating TNF-alpha and Fas/FasL-mediated apoptosis in Streptozotocin-Induced Diabetic Rats.
Food Chem. Toxicol.
PUBLISHED: 05-04-2013
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GABA tea is a tea product that contains a high level of gamma-aminobutyric acid (GABA). This study investigated the effects of GABA tea on the heart in a diabetic rat model. Male Wistar rats were injected with 55 mg/kg streptozotocin (STZ) to induce diabetes for 2 weeks and then orally given dosages of 4.55 and 45.5 mg/kg/day GABA tea extract for 6 weeks. The results revealed that fasting blood glucose levels returned to normal levels in GABA tea-treated diabetic rats, but not in the untreated diabetic rats. Additionally, GABA tea effectively inhibited cardiac fibrosis induced by STZ. Further experiments showed that the STZ-induced protein levels of tumor necrosis factor-alpha (TNFalpha), Fas, activated caspase-8 and caspase-3 were significantly inhibited by the GABA tea treatment. Therefore, our data suggest that the inhibiting effect of GABA tea on STZ-induced cardiac fibrosis in diabetic rats may be mediated by reducing blood glucose and further attenuating TNF-alpha expression and/or Fas/Fas ligand (FasL)-mediated apoptosis. These findings will provide implications for the potential anti-diabetic properties of GABA tea.
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Highly enantio- and diastereoselective allylic alkylation of Morita-Baylis-Hillman carbonates with allyl ketones.
J. Org. Chem.
PUBLISHED: 04-26-2013
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The asymmetric allylic alkylation of Morita-Baylis-Hillman (MBH) carbonates with allyl ketones has been developed. The ?-regioselective alkylation adducts, containing a hexa-1,5-diene framework with important synthetic value, were achieved in up to 83% yield, >99% ee, and 50:1 dr by using a commercially available Cinchona alkaloid as the catalyst. From the allylic alkylation adduct, a cyclohexene bearing two adjacent chiral centers was readily prepared.
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Strong magnetic enhancement in self-assembled multiferroic-ferrimagnetic nanostructures.
Nanoscale
PUBLISHED: 04-16-2013
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In the past decade, self-assembled vertical nano-heterostructures have drawn considerable attention because a high interface-to-volume ratio can be used to tailor or create functionalities. We have systematically investigated the magnetic properties of oxide heterostructures consisting of the CoFe2O4 nanopillars embedded in the BiFeO3 matrix using macroscopic magnetization measurements and element-selective soft X-ray absorption magnetic circular dichroism (XMCD) at the Co- and Fe-L2,3 edge. The magnetization and XMCD data show that the total ordered magnetic moment of Co(2+) in CoFe2O4-BiFeO3 nano-heterostructures is strongly enhanced. This study clearly indicates that the high interface-to-volume ratio vertical nanostructure creates a strong ferromagnetic and antiferromagnetic magnetic coupling via an interface. Furthermore, the magnetic coupling can be tuned in the multiferroic-ferrimagnetic self-assembled heterostructures by controlling the spacing between nanopillars.
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EGRF conjugated PEGylated nanographene oxide for targeted chemotherapy and photothermal therapy.
Biomaterials
PUBLISHED: 04-02-2013
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Low accumulation of chemotherapeutic agent in tumor tissue and multidrug resistance (MDR) present a major obstacle to curing cancer treatment. Therefore, how to combine several therapeutics in one system is a key issue to overcome the problem. Here, we demonstrate epidermal growth factor receptor (EGFR) antibody-conjugated PEGylated nanographene oxide (PEG-NGO) to carry epirubicin (EPI) for tumor targeting and triple-therapeutics (growth signal blocking, chemotherapy, photothermal therapy) in tumor treatment. This synergistic targeted treatment simultaneously enhances the local drug concentration (6.3-fold) and performs the ultra-efficient tumor suppression to significantly prolong the mice survival (over the course of 50 days).
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Clinical features and genetic analysis of Taiwanese patients with the hyper IgM syndrome phenotype.
Pediatr. Infect. Dis. J.
PUBLISHED: 03-30-2013
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Hyper IgM syndrome (HIGM), characterized by recurrent infections, low serum IgG and IgA, normal or elevated IgM, defective class switch recombination and somatic hypermutation, are heterogeneous disorders with at least 6 distinct molecular defects, including the CD40 ligand (CD40L) and the nuclear factor ?B essential modulator (NEMO, also known as IKK?) genes (both X-linked), the CD40, activation-induced cytidine deaminase (AICDA or AID), uracil-DNA glycosylase genes (autosomal recessive) and I?B? (IKBA) (autosomal dominant). Our objective was to determine the molecular basis and clinical features of Taiwanese patients with the HIGM phenotype.
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Kinetics and thermodynamics of small molecule binding to pincer-PCP rhodium(I) complexes.
Inorg Chem
PUBLISHED: 03-29-2013
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The kinetics and thermodynamics of the binding of several small molecules, L (L = N2, H2, D2, and C2H4), to the coordinatively unsaturated pincer-PCP rhodium(I) complexes Rh[(t)Bu2PCH2(C6H3)CH2P(t)Bu2] (1) and Rh[(t)Bu2P(CH2)2(CH)(CH2)2P(t)Bu2] (2) in organic solvents (n-heptane, toluene, THF, and cyclohexane-d12) have been investigated by a combination of kinetic flash photolysis methods, NMR equilibrium studies, and density functional theory (DFT) calculations. Using various gas mixtures and monitoring by NMR until equilibrium was established, the relative free energies of binding of N2, H2, and C2H4 in cyclohexane-d12 were found to increase in the order C2H4 < N2 < H2. Time-resolved infrared (TRIR) and UV-vis transient absorption spectroscopy revealed that 355 nm excitation of 1-L and 2-L results in the photoejection of ligand L. The subsequent mechanism of binding of L to 1 and 2 to regenerate 1-L and 2-L is determined by the structure of the PCP ligand framework and the nature of the solvent. In both cases, the primary transient is a long-lived, unsolvated species (? = 50-800 ns, depending on L and its concentration in solution). For 2, this so-called less-reactive form (LRF) is in equilibrium with a more-reactive form (MRF), which reacts with L at diffusion-controlled rates to regenerate 2-L. These two intermediates are proposed to be different conformers of the three-coordinate (PCP)Rh fragment. For 1, a similar mechanism is proposed to occur, but the LRF to MRF step is irreversible. In addition, a parallel reaction pathway was observed that involves the direct reaction of the LRF of 1 with L, with second-order rate constants that vary by almost 3 orders of magnitude, depending on the nature of L (in n-heptane, k = 6.7 × 10(5) M(-1) s(-1) for L = C2H4; 4.0 × 10(6) M(-1) s(-1) for L = N2; 5.5 × 10(8) M(-1) s(-1) for L = H2). Experiments in the more coordinating solvent, THF, revealed the binding of THF to 1 to generate 1-THF, and its subsequent reaction with L, as a competing pathway.
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MicroRNA-495 inhibits proliferation of glioblastoma multiforme cells by downregulating cyclin-dependent kinase 6.
World J Surg Oncol
PUBLISHED: 03-26-2013
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Glioblastoma multiforme (GBM) is the most aggressive type of glioma and carries the poorest chances of survival. There is therefore an urgent need to understand the mechanisms of glioma tumorigenesis and develop or improve therapeutics. The aim of this study was to assess the possible prognostic value of cyclin-dependent kinase 6 (CDK6) and the effects of microRNA-495 (miR-495) manipulation on CDK6 expression and cell survival in glioma cells.
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Maturation of Toll-like receptor 1-4 responsiveness during early life.
Early Hum. Dev.
PUBLISHED: 03-19-2013
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Toll-like receptors (TLRs) are part of the highly conserved components of the innate immune system, and have been investigated extensively; however, little is known about TLR function during early postnatal life, a critical period for immune maturation.
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Magnetic gold-nanorod/ PNIPAAmMA nanoparticles for dual magnetic resonance and photoacoustic imaging and targeted photothermal therapy.
Biomaterials
PUBLISHED: 03-13-2013
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Nanomedicine can provide a multi-functional platform for image-guided diagnosis and treatment of cancer. Although gold nanorods (GNRs) have been developed for photoacoustic (PA) imaging and near infra-red (NIR) photothermal applications, their efficiency has remained limited by low thermal stability. Here we present the synthesis, characterization, and functional evaluation of non-cytotoxic magnetic polymer-modified gold nanorods (MPGNRs), designed to act as dual magnetic resonance imaging (MRI) and PA imaging contrast agents. In addition, their high magnetization allowed MPGNRs to be actively localized and concentrated by targeting with an external magnet. Finally, MPGNRs significantly enhanced the NIR-laser-induced photothermal effect due to their increased thermal stability. MPGNRs thus provide a promising new theranostic platform for cancer diagnosis and treatment by combining dual MR/PA imaging with highly effective targeted photothermal therapy.
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Early predictors of outcomes in pediatric lupus nephritis: Focus on proliferative lesions.
Semin. Arthritis Rheum.
PUBLISHED: 03-07-2013
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Studies regarding the clinical features and outcomes of pediatric lupus nephritis are limited, and risk factors of poor outcome in the more severe form of renal involvement, proliferative lupus nephritis (PLN), are poorly understood. This study analyzed the data from a large prospective cohort of childhood systemic lupus erythematosus to determine such risk factors.
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Non-invasive synergistic treatment of brain tumors by targeted chemotherapeutic delivery and amplified focused ultrasound-hyperthermia using magnetic nanographene oxide.
Adv. Mater. Weinheim
PUBLISHED: 03-07-2013
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The combination of chemo-thermal therapy is the best strategy to ablate tumors, but how to heat deep tumor tissues effectively without side-damage is a challenge. Here, a systemically delivered nanocarrier is designed with multiple advantages, including superior heat absorption, highly efficient hyperthermia, high drug capacity, specific targeting ability, and molecular imaging, to achieve both high antitumor efficacy and effective amplification of hyperthermia with minimal side effects.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.