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Find video protocols related to scientific articles indexed in Pubmed.
N-acetyltransferase 2 gene polymorphism as a biomarker for susceptibility to bladder cancer in Bangladeshi population.
Asia Pac J Clin Oncol
PUBLISHED: 09-07-2014
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To investigate the association between the three most common single nucleotide polymorphisms of the N-acetyltransferase 2 gene together with cigarette smoking and the risk of developing bladder cancer and its aggressiveness.
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Changes in cell density and morphology of selected cells of the ageing human dental pulp.
Gerodontology
PUBLISHED: 08-15-2014
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The aim of this study was to determine the changes in cell density and morphology of selected cells of the ageing human dental pulp.
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Comparison of values of traditionally measured venous bicarbonate with calculated arterial bicarbonate in intensive care unit patients of a hospital in a third-world country.
Niger Med J
PUBLISHED: 08-13-2014
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Measurement of serum or plasma bicarbonate (HCO3 (-)) from a sample of peripheral venous blood is routinely practiced in hospital patient managements. HCO3 (-) status can also be obtained by a simple calculation during blood gas analysis requiring arterial blood as sample which is cumbersome for both patient and doctor. This study compared the measured bicarbonate levels with calculated arterial values in intensive care unit (ICU) patients to determine whether traditionally measured venous HCO3 (-) and calculated HCO3 (-) values [from arterial blood gas (ABG) analyzers] can be used interchangeably.
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Orally active osteoanabolic agent GTDF binds to adiponectin receptors, with a preference for AdipoR1, induces adiponectin-associated signaling, and improves metabolic health in a rodent model of diabetes.
Diabetes
PUBLISHED: 05-21-2014
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Adiponectin is an adipocytokine that signals through plasma membrane-bound adiponectin receptors 1 and 2 (AdipoR1 and -2). Plasma adiponectin depletion is associated with type 2 diabetes, obesity, and cardiovascular diseases. Adiponectin therapy, however, is yet unavailable owing to its large size, complex multimerization, and functional differences of the multimers. We report discovery and characterization of 6-C-?-D-glucopyranosyl-(2S,3S)-(+)-5,7,3',4'-tetrahydroxydihydroflavonol (GTDF) as an orally active adiponectin mimetic. GTDF interacted with both AdipoRs, with a preference for AdipoR1. It induced adiponectin-associated signaling and enhanced glucose uptake and fatty acid oxidation in vitro, which were augmented or abolished by AdipoR1 overexpression or silencing, respectively. GTDF improved metabolic health, characterized by elevated glucose clearance, ?-cell survival, reduced steatohepatitis, browning of white adipose tissue, and improved lipid profile in an AdipoR1-expressing but not an AdipoR1-depleted strain of diabetic mice. The discovery of GTDF as an adiponectin mimetic provides a promising therapeutic tool for the treatment of metabolic diseases.
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Effect of cellulose nanowhiskers on surface morphology, mechanical properties, and cell adhesion of melt-drawn polylactic Acid fibers.
Biomacromolecules
PUBLISHED: 03-28-2014
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Polylactic acid (PLA) fibers were produced with an average diameter of 11.2 (± 0.9) ?m via a melt-drawing process. The surface of the PLA fibers was coated with blends of cellulose nanowhiskers (CNWs) (65 to 95 wt %) and polyvinyl acetate (PVAc). The CNWs bound to the smooth PLA fiber surface imparted roughness, with the degree of roughness depending on the coating blend used. The fiber tensile modulus increased 45% to 7 GPa after coating with 75 wt % CNWs compared with the uncoated PLA fibers, and a significant increase in the fiber moisture absorption properties at different humidity levels was also determined. Cytocompatibility studies using NIH-3T3 mouse fibroblast cells cultured onto CNWs-coated PLA surface revealed improved cell adhesion compared with the PLA control, making this CNW surface treatment applicable for biomedical and tissue engineering applications. Initial studies also showed complete cell coverage within 2 days.
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WNK4 is the major WNK positively regulating NCC in the mouse kidney.
Biosci. Rep.
PUBLISHED: 03-25-2014
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By analysing the pathogenesis of a hereditary hypertensive disease, PHAII (pseudohypoaldosteronism type II), we previously discovered that WNK (with-no-lysine kinase)-OSR1/SPAK (oxidative stress-responsive 1/Ste20-like proline/alanine-rich kinase) cascade regulates NCC (Na-Cl co-transporter) in the DCT (distal convoluted tubules) of the kidney. However, the role of WNK4 in the regulation of NCC remains controversial. To address this, we generated and analysed WNK4-/- mice. Although a moderate decrease in SPAK phosphorylation and a marked increase in WNK1 expression were evident in the kidneys of WNK4-/- mice, the amount of phosphorylated and total NCC decreased to almost undetectable levels, indicating that WNK4 is the major WNK positively regulating NCC, and that WNK1 cannot compensate for WNK4 deficiency in the DCT. Insulin- and low-potassium diet-induced NCC phosphorylation were abolished in WNK4-/- mice, establishing that both signals to NCC were mediated by WNK4. As shown previously, a high-salt diet decreases phosphorylated and total NCC in WNK4+/+ mice via AngII (angiotensin II) and aldosterone suppression. This was not ameliorated by WNK4 knock out, excluding the negative regulation of WNK4 on NCC postulated to be active in the absence of AngII stimulation. Thus, WNK4 is the major positive regulator of NCC in the kidneys.
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Involvement of astroglial glutamate-glutamine shuttle in modulation of the jaw-opening reflex following infraorbital nerve injury.
Eur. J. Neurosci.
PUBLISHED: 02-17-2014
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To evaluate the mechanisms underlying orofacial motor dysfunction associated with trigeminal nerve injury, we studied the astroglial cell activation following chronic constriction injury (CCI) of the infraorbital nerve (ION) immunohistochemically, nocifensive behavior in ION-CCI rats, and the effect of the glutamine synthase (GS) blocker methionine sulfoximine (MSO) on the jaw-opening reflex (JOR), and also studied whether glutamate-glutamine shuttle mechanism is involved in orofacial motor dysfunction. GFAP-immunoreactive (IR) cells were observed in the trigeminal motor nucleus (motV) 3 and 14 days after ION-CCI, and the nocifensive behavior and JOR amplitude were also strongly enhanced at these times. The number of GS- and GFAP-IR cells was also significantly higher in ION-CCI rats on day 7. The amplitude and duration of the JOR were strongly suppressed after MSO microinjection (m.i.) into the motV compared with that before MSO administration in ION-CCI rats. After MSO administration, the JOR amplitude was strongly suppressed, and the duration of the JOR was shortened. Forty minutes after m.i. of glutamine, the JOR amplitude was gradually returned to the control level and the strongest attenuation of the suppressive effect of MSO was observed at 180 min after glutamine m.i. In addition, glutamine also attenuated the MSO effect on the JOR duration, and the JOR duration was extended and returned to the control level thereafter. The present findings suggest that astroglial glutamate-glutamine shuttle in the motV is involved in the modulation of excitability of the trigeminal motoneurons affecting the enhancement of various jaw reflexes associated with trigeminal nerve injury.
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Role of accumulated calcium in alleviating aluminum injury in wheat plants.
ScientificWorldJournal
PUBLISHED: 01-01-2014
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Aluminum (Al) sensitive wheat cultivar kalyansona was grown for 14 d in a range of Ca solution (125, 625, and 2500 ?M) plus other nutrients without Al. At 14 d after Ca treatment, half of these plants were harvested (H1), and the rest of the plants were exposed to 100 ?M Al for additional 6 d and harvested (H2). Severe Al injury was found only in the plants with the lowest supply of Ca before Al treatment. Aluminum concentration in the apoplastic fluid was very high at 125 ?M Ca probably because the plasma membrane of some of the cells was destroyed due to the attack of 100 ?M Al. Aluminum content in roots decreased with increasing supply of Ca before Al treatment. Calcium content decreased drastically at harvest (H2) in the plants with 100 ?M Al. Under Al stress conditions, the plant responded to Al in different ways due to not only the different Ca supply but also the variation of Ca content in the plant tissues. Actually, the plants having the largest Ca content in the roots before Al treatment can receive less Al injury during Al treatment. To substantiate this idea, a companion study was conducted to investigate the effects of 2500 ?M Ca supply during, before, and after 100 ?M Al treatment on root growth. The results indicated clearly that exogenous Ca supply before Al treatment is able to alleviate Al injury but less effective than Ca supply during Al treatment.
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Pancreastatin is an endogenous peptide that regulates glucose homeostasis.
Physiol. Genomics
PUBLISHED: 09-24-2013
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Pancreastatin (PST) is a regulatory peptide containing 49 amino acids, first isolated from porcine pancreas. Intracellular and extracellular processing of the prohormone Chromogranin A (Chga) results various bioactive peptides of which PST has dysglycemic activity. PST regulates glucose, lipid, and protein metabolism in liver and adipose tissues. It also regulates the secretion of leptin and expression of leptin and uncoupling protein 2 in adipose tissue. In Chga knockout mice, PST induces gluconeogenesis in the liver. PST reduces glucose uptake in mice hepatocytes and adipocytes. In rat hepatocytes, PST induces glycogenolysis and glycolysis and inhibits glycogen synthesis. In rat adipocytes, PST inhibits lactate production and lipogenesis. These metabolic effects are confirmed in humans. In the dual signaling mechanism of PST receptor, mostly PST activates G?q/11 protein leads to the activation of phospholipase C ?3-isoform, therefore increasing cytoplasmic free calcium and stimulating protein kinase C. PST inhibits the cell growth in rat HTC hepatoma cells, mediated by nitric oxide and cyclic GMP production. Elevated levels of PST correlating with catecholamines have been found in gestational diabetes and essential hypertension. Rise in the blood PST level in Type 2 diabetes suggests that PST is a negative regulator of insulin sensitivity and glucose homeostasis.
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Fecal carriage of multi-drug resistant and extended spectrum ?-lactamases producing E. coli in household pigeons, Bangladesh.
Vet. Microbiol.
PUBLISHED: 08-17-2013
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Antibiotic resistance and ESBL constitute a risk to human and animal health. Birds residing close to humans could mirror the spectrum of human associated antibiotic resistance. Household pigeons were screened in Bangladesh to shed light on human associated, as well as, environmental antibiotic resistance. Escherichia coli from pigeons (n=150) were tested against 11 antibiotics. 89% E. coli isolates were resistant to one or more critically important human antibiotics like ampicillin, cefadroxil, mecillinam, ciprofloxacin, gentamicin and tigecycline. No carbapenamase-producers were detected and the lower ESBL prevalence (5%) in pigeons. ESBL-producing E. coli isolates had blaCTX-M-15 genes. Pigeons shared some bacterial clones and had bird associated sequence types like E. coli ST1408. Fecal carriage of bacteria resistance of critically important human antibiotics, together with examples of shared genotypes among pigeons, indicate the human-birds and bird to bird transmissions are important in the epidemiology of antibiotic resistance.
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A genetic and developmental pathway from STAT3 to the OCT4-NANOG circuit is essential for maintenance of ICM lineages in vivo.
Genes Dev.
PUBLISHED: 06-22-2013
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Although it is known that OCT4-NANOG are required for maintenance of pluripotent cells in vitro, the upstream signals that regulate this circuit during early development in vivo have not been identified. Here we demonstrate, for the first time, signal transducers and activators of transcription 3 (STAT3)-dependent regulation of the OCT4-NANOG circuitry necessary to maintain the pluripotent inner cell mass (ICM), the source of in vitro-derived embryonic stem cells (ESCs). We show that STAT3 is highly expressed in mouse oocytes and becomes phosphorylated and translocates to the nucleus in the four-cell and later stage embryos. Using leukemia inhibitory factor (Lif)-null embryos, we found that STAT3 phosphorylation is dependent on LIF in four-cell stage embryos. In blastocysts, interleukin 6 (IL-6) acts in an autocrine fashion to ensure STAT3 phosphorylation, mediated by janus kinase 1 (JAK1), a LIF- and IL-6-dependent kinase. Using genetically engineered mouse strains to eliminate Stat3 in oocytes and embryos, we firmly establish that STAT3 is essential for maintenance of ICM lineages but not for ICM and trophectoderm formation. Indeed, STAT3 directly binds to the Oct4 and Nanog distal enhancers, modulating their expression to maintain pluripotency of mouse embryonic and induced pluripotent stem cells. These results provide a novel genetic model of cell fate determination operating through STAT3 in the preimplantation embryo and pluripotent stem cells in vivo.
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Automated SPME-GC-MS monitoring of headspace metabolomic responses of E. coli to biologically active components extracted by the coating.
Anal. Chim. Acta
PUBLISHED: 02-18-2013
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Monitoring extracellular metabolites of bacteria is very useful for not only metabolomics research but also for assessment of the effects of various chemicals, including antimicrobial agents and drugs. Herein, we describe the automated headspace solid-phase microextraction (HS-SPME) method coupled with gas chromatography-mass spectrometry (GC-MS) for the qualitative as well as semi-quantitative determination of metabolic responses of Escherichia coli to an antimicrobial agent, cinnamaldehyde. The minimum inhibitory concentration of cinnamaldehyde was calculated to be 2 g L(-1). We found that cinnamaldehyde was an important factor influencing the metabolic profile and growth process. A higher number of metabolites were observed during the mid-logarithmic growth phase. The metabolite variations (types and concentrations) induced by cinnamaldehyde were dependent on both cell density and the dose of cinnamaldehyde. Simultaneously, 25 different metabolites were separated and detected (e.g., indole, alkane, alcohol, organic acids, esters, etc.) in headspace of complex biological samples due to intermittent addition of high dose of cinnamaldehyde. The study was done using an automated system, thereby minimizing manual workup and indicating the potential of the method for high-throughput analysis. These findings enhanced the understanding of the metabolic responses of E. coli to cinnamaldehyde shock effect and demonstrated the effectiveness of the SPME-GC-MS based metabolomics approach to study such a complex biological system.
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?-Cyclodextrin conjugated magnetic, fluorescent silica core-shell nanoparticles for biomedical applications.
Carbohydr Polym
PUBLISHED: 02-07-2013
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We present synthesis of highly uniform magnetic nanocomposite material possessing an assortment of important functionalities: magnetism, luminescence, cell-targeting, and hydrophobic drug delivery. Magnetic particle Fe3O4 is encapsulated within a shell of SiO2 that ensures biocompatibility of the nanocomposite as well as act as a host for fluorescent dye (FITC), cancer-targeting ligand (folic acid), and a hydrophobic drug storage-delivering vehicle (?-cyclodextrin). Our preliminary results suggest that such core-shell nanocomposite can be a smart theranostic candidate for simultaneous fluorescence imaging, magnetic manipulation, cancer cell-targeting and hydrophobic drug delivery.
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Photosystem II protein clearance and FtsH function in the diatom Thalassiosira pseudonana.
Photosyn. Res.
PUBLISHED: 01-28-2013
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All oxygenic photoautotrophs suffer photoinactivation of their Photosystem II complexes, at a rate driven by the instantaneous light level. To maintain photosynthesis, PsbA subunits are proteolytically removed from photoinactivated Photosystem II complexes, primarily by a membrane-bound FtsH protease. Diatoms thrive in environments with fluctuating light, such as coastal regions, in part because they enjoy a low susceptibility to photoinactivation of Photosystem II. In a coastal strain of the diatom Thalassiosira pseudonana growing across a range of light levels, active Photosystem II represents only about 42 % of the total Photosystem II protein, with the remainder attributable to photoinactivated Photosystem II awaiting recycling. The rate constant for removal of PsbA protein increases with growth light, in parallel with an increasing content of the FtsH protease relative to the substrate PsbA. An offshore strain of Thalassiosira pseudonana, originating from a more stable light environment, had a lower content of FtsH and slower rate constants for removal of PsbA. We used this data to generate the first estimates for in vivo proteolytic degradation of photoinactivated PsbA per FtsH6 protease, at ~3.9 × 10(-2) s(-1), which proved consistent across growth lights and across the onshore and offshore strains.
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Sphingoid bases from sea cucumber induce apoptosis in human hepatoma HepG2 cells through p-AKT and DR5.
Oncol. Rep.
PUBLISHED: 01-04-2013
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Biofunctional marine compounds have recently received substantial attention for their nutraceutical characteristics. In this study, we investigated the apoptosis-inducing effects of sphingoid bases prepared from sea cucumber using human hepatoma HepG2 cells. Apoptotic effects were determined by cell viability assay, DNA fragmentation assay, caspase-3 and caspase-8 activities. The expression levels of apoptosis-inducing death receptor-5 (DR5) and p-AKT were assayed by western blot analysis, and mRNA expression of bax, GADD45 and PPAR? was assayed by quantitative RT-PCR analysis. Sphingoid bases from sea cucumber markedly reduced the cell viability of HepG2 cells. DNA fragmentation indicative of apoptosis was observed in a dose-dependent manner. The expression levels of the apoptosis inducer protein Bax were increased by the sphingoid bases from sea cucumber. GADD45, which plays an important role in apoptosis-inducing pathways, was markedly upregulated by sphingoid bases from sea cucumber. Upregulation of PPAR? mRNA was also observed during apoptosis induced by the sphingoid bases. The expression levels of DR5 and p-AKT proteins were increased and decreased, respectively, as a result of the effects of sphingoid bases from sea cucumber. The results indicate that sphingoid bases from sea cucumber induce apoptosis in HepG2 cells through upregulation of DR5, Bax, GADD45 and PPAR? and downregulation of p-AKT. Our results show for the first time the functional properties of marine sphingoid bases as inducers of apoptosis in HepG2 cells.
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?-Galactosidase-based colorimetric paper sensor for determination of heavy metals.
Anal. Chem.
PUBLISHED: 10-27-2011
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We demonstrate a novel approach for rapid, selective, and sensitive detection of heavy metals using a solid-phase bioactive lab-on-paper sensor that is inkjet printed with sol-gel entrapped reagents to allow colorimetric visualization of the enzymatic activity of ?-galactosidase (B-GAL). The bioactive paper assay is able to detect a range of heavy metals, either alone or as mixtures, in as little as 10 min, with detection limits as follows: Hg(II) = 0.001 ppm; Ag(I) = 0.002 ppm, Cu(II) = 0.020 ppm; Cd(II) = 0.020 ppm; Pb(II) = 0.140 ppm; Cr(VI) = 0.150 ppm; Ni(II) = 0.230 ppm. The paper-based assay was immune to interferences from nontoxic metal ions such as Na(+) or K(+), could be used to detect heavy metals that were spiked into tap water or lake water, and provided quantitative data that was in agreement with values obtained by atomic absorption. With the incorporation of standard chromogenic metal sensing reagents into a multiplexed bioactive paper sensor, it was possible to identify specific metals in mixtures, albeit with much lower detection limits than were obtained with the enzymatic assay. The paper-based sensor should be valuable for rapid, on-site screening of trace levels of heavy metals in resource limited areas and developing countries.
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Real-space observation of local anisotropic correlation between buckled dimers on Si(100) induced by a bidentate adsorbed molecule.
Chem. Commun. (Camb.)
PUBLISHED: 08-11-2011
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The anisotropic correlation between buckled dimers on Si(100) was investigated by scanning tunneling microscopy. A bidentate ligand molecule was used to pin two neighboring dimers at 300 K. The chemically pinned dimer induces antiferromagnetic interaction along the dimer rows. Observed results agree well with Monte-Carlo simulations semi-quantitatively.
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DIMINUTO 1 affects the lignin profile and secondary cell wall formation in Arabidopsis.
Planta
PUBLISHED: 08-01-2011
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Brassinosteroids (BRs) play a crucial role in plant growth and development and DIMINUTO 1 (DIM1), a protein involved in BR biosynthesis, was previously identified as a cell elongation factor in Arabidopsis thaliana. Through promoter expression analysis, we showed that DIM1 was expressed in most of the tissue types in seedlings and sectioning of the inflorescence stem revealed that DIM1 predominantly localizes to the xylem vessels and in the interfascicular cambium. To investigate the role of DIM1 in cell wall formation, we generated loss-of-function and gain-of-function mutants. Disruption of the gene function caused a dwarf phenotype with up to 38 and 23% reductions in total lignin and cellulose, respectively. Metabolite analysis revealed a significant reduction in the levels of fructose, glucose and sucrose in the loss-of-function mutant compared to the wild type control. The loss-of-function mutant also had a lower S/G lignin monomer ratio relative to wild type, but no changes were detected in the gain-of-function mutant. Phloroglucinol and toluidine blue staining showed a size reduction of the vascular apparatus with smaller and disintegrated xylem vessels in the inflorescence stem of the loss-of-function mutant. Taken together, these data indicate a role for DIM1 in secondary cell wall formation. Moreover, this study demonstrated the potential role of BR hormones in modulating cell wall structure and composition.
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Nickel nanowires induced and reactive oxygen species mediated apoptosis in human pancreatic adenocarcinoma cells.
Int J Nanomedicine
PUBLISHED: 07-13-2011
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The ability to evade apoptosis is one of the key properties of cancer. The apoptogenic effect of nickel nanowires (Ni NWs) on cancer cell lines has never been adequately addressed. Due to the unique physicochemical characteristics of Ni NWs, we envision the development of a novel anticancer therapeutics specifically for pancreatic cancer. Thus, we investigated whether Ni NWs induce ROS-mediated apoptosis in human pancreatic adenocarcinoma (Panc-1) cells.
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Neural mechanisms of swallowing and effects of taste and other stimuli on swallow initiation.
Biol. Pharm. Bull.
PUBLISHED: 11-05-2010
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Swallowing involves several motor processes such as bolus formation and intraoral transport of a food bolus (oral stage) and a series of visceral events that occur in a relatively fixed timed sequence but are to some degree modifiable (pharyngeal stage or swallow reflex). Reflecting the progressive aging of society, patients with swallowing disorders (i.e., dysphagia) are increasing. Therefore, there is expanding social demand for the development of better rehabilitation treatment of dysphagic patients. To date, many dysphagia diets have been developed and are available commercially to help bring back the pleasure of mealtimes to dysphagia patients. Texture modification of food to make the food bolus easier to swallow with less risk of aspiration is one of the important elements in dysphagia diets from the viewpoint of safety assurance. However, for the further development of dysphagia diets, new attempts based on new concepts are needed. One of the possible approaches is to develop dysphagia diets that facilitate swallow initiation. For this approach, an understanding of the mechanisms of swallow initiation and identification of factors that facilitate or suppress swallow initiation are important. In this review, we first summarize the neural mechanisms of swallowing and effects of taste and other inputs on swallow initiation based on data mainly obtained from experimental animals. Then we introduce a recently established technique for eliciting swallowing using electrical stimulation in humans and our ongoing studies using this technique.
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Scanning tunneling microscopy, spectroscopy, and nanolithography of epitaxial graphene chemically modified with aryl moieties.
J. Am. Chem. Soc.
PUBLISHED: 10-12-2010
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The reduction of diazonium salts has recently been proposed as a robust covalent modification scheme for graphene surfaces. While preliminary studies have provided indirect evidence that this strategy decorates graphene with aryl moieties, the molecular ordering and conformation of the resulting adlayer have not been directly measured. In this Article, we report molecular-resolution characterization of the adlayer formed via the spontaneous reduction of 4-nitrophenyl diazonium (4-NPD) tetrafluoroborate on epitaxial graphene on SiC(0001) using ultrahigh vacuum (UHV) scanning tunneling microscopy (STM) and spectroscopy (STS). An atomically flat inhomogeneous layer of covalently bonded organic molecules is observed after annealing the chemically treated surface at ?500 °C in UHV. STM and STS results indicate that the adlayer consists predominantly of aryl oligomers that sterically prevent uniform and complete covalent modification of the graphene surface. The adsorbed species can be selectively desorbed by the STM tip above a threshold sample bias of -5 V and tunneling current of 1 nA, thus enabling the fabrication of a diverse range of graphene nanopatterns at the sub-5 nm length scale.
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Modulation of spindle discharge from jaw-closing muscles during chewing foods of different hardness in awake rabbits.
Brain Res. Bull.
PUBLISHED: 04-21-2010
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The relationships between jaw-closing muscle spindle unit discharge and the hardness of foods were evaluated during chewing in awake rabbits. Spindle unit discharges recorded from the left mesencephalic trigeminal nucleus were correlated with the simultaneous recording of jaw movements and electromyographic (EMG) activities of the left masseter (jaw-closing) muscle during chewing soft and hard foods. A chewing cycle was divided into the fast-closing (FC), slow-closing (SC) and opening (OP) phases according to jaw movements. The chewing was classified as ipsilateral and contralateral chewing according to ipsilateral and contralateral to the recording side of the neuron, respectively. Spindle unit discharge was significantly higher during the FC and SC phases of the hard food than the soft food during both ipsilateral and contralateral chewing. The discharge was observed to be higher when the masseter muscle activity was higher. A comparison between the chewing sides reveals that the discharge was significantly higher during the slow-closing phase of ipsilateral chewing than contralateral chewing. From the above findings, the relationship of the spindle unit discharge with the hardness of foods was observed. Moreover, this relationship exists even when an animal chews food on the contralateral side suggesting the significance of the muscle spindle information for smooth chewing. In addition, the phase dependent difference of the spindle unit discharge between chewing sides suggests the distinct roles of the spindle information on the chewing and non-chewing sides.
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Reagentless bidirectional lateral flow bioactive paper sensors for detection of pesticides in beverage and food samples.
Anal. Chem.
PUBLISHED: 10-01-2009
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A reagentless bioactive paper-based solid-phase biosensor was developed for detection of acetylcholinesterase (AChE) inhibitors, including organophosphate pesticides. The assay strip is composed of a paper support (1 x 10 cm), onto which AChE and a chromogenic substrate, indophenyl acetate (IPA), were entrapped using biocompatible sol-gel derived silica inks in two different zones (e.g., sensing and substrate zones). The assay protocol involves first introducing the sample to the sensing zone via lateral flow of a pesticide-containing solution. Following an incubation period, the opposite end of the paper support is placed into distilled deionized water (ddH(2)O) to allow lateral flow in the opposite direction to move paper-bound IPA to the sensing area to initiate enzyme catalyzed hydrolysis of the substrate, causing a yellow-to-blue color change. The modified sensor is able to detect pesticides without the use of any external reagents with excellent detection limits (bendiocarb approximately 1 nM; carbaryl approximately 10 nM; paraoxon approximately 1 nM; malathion approximately 10 nM) and rapid response times (approximately 5 min). The sensor strip showed negligible matrix effects in detection of pesticides in spiked milk and apple juice samples. Bioactive paper-based assays on pesticide residues collected from food samples showed good agreement with a conventional mass spectrometric assay method. The bioactive paper assay should, therefore, be suitable for rapid screening of trace levels of organophosphate and carbamate pesticides in environmental and food samples.
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Development of a bioactive paper sensor for detection of neurotoxins using piezoelectric inkjet printing of sol-gel-derived bioinks.
Anal. Chem.
PUBLISHED: 06-05-2009
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There is an increasing interest in new strategies to rapidly detect analytes of clinical and environmental interest without the need for sophisticated instrumentation. As an example, the detection of acetylcholinesterase (AChE) inhibitors such as neurotoxins and organophosphates has implications for neuroscience, drug assessment, pharmaceutical development, and environmental monitoring. Functionalization of surfaces with multiple reagents, including enzymes and chromogenic reagents, is a critical component for the effective development of "dipstick" or lateral flow biosensors. Herein, we describe a novel paper-based solid-phase biosensor that utilizes piezoelectric inkjet printing of biocompatible, enzyme-doped, sol-gel-based inks to create colorimetric sensor strips. For this purpose, polyvinylamine (PVAm, which captures anionic agents) was first printed and then AChE was overprinted by sandwiching the enzyme within two layers of biocompatible sol-gel-derived silica on paper. AChE inhibitors, including paraoxon and aflatoxin B1, were detected successfully using this sensor by measuring the residual activity of AChE on paper, using Ellmans colorimetric assay, with capture of the 5-thio-2-nitrobenzoate (TNB(-)) product on the PVAm layer. The assay provided good detection limits (paraoxon, approximately 100 nM; aflatoxin B1, approximately 30 nM) and rapid response times (<5 min). Detection could be achieved either by eye or using a digital camera and image analysis software, avoiding the need for expensive and sophisticated instrumentation. We demonstrate that the bioactive paper strip can be used either as a dipstick or a lateral flow-based biosensor. The use of sol-gel-based entrapment produced a sensor that retained enzyme activity and gave reproducible results after storage at 4 degrees C for at least 60 days, making the system suitable for storage and use in the field.
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Growth inhibition and induction of apoptosis of colon cancer cell lines by applying marine phospholipid.
Nutr Cancer
PUBLISHED: 01-01-2009
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Polyunsaturated fatty acids (PUFAs) exhibit beneficial biological functions in carcinogenic processes. We examined the effects of PUFAs in the acid and phospholipid forms on three colon cancer cell lines (HT-29, Caco-2, and DLD-1). Docosahexaenoic acid (DHA) and eicosapentaenoic (EPA) in both acid and phospholipid forms showed growth inhibition effects on experimental colon cancer cell lines. But these PUFAs had the strongest growth-inhibitory effect on HT-29 than Caco-2 and DLD-1. Combined application of PUFAs and sodium butyrate (NaBt) increased the growth inhibition. Growth inhibition was apparently caused by increased lipid peroxidation. DHA or EPA in combination with NaBt significantly increased caspase-3 activity compared to control. DHA and DHA-rich phosphatidylcholine decreased Bcl-2 level in HT-29 and Caco-2 cells.
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Cannabinoids facilitate the swallowing reflex elicited by the superior laryngeal nerve stimulation in rats.
PLoS ONE
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Cannabinoids have been reported to be involved in affecting various biological functions through binding with cannabinoid receptors type 1 (CB1) and 2 (CB2). The present study was designed to investigate whether swallowing, an essential component of feeding behavior, is modulated after the administration of cannabinoid. The swallowing reflex evoked by the repetitive electrical stimulation of the superior laryngeal nerve in rats was recorded before and after the administration of the cannabinoid receptor agonist, WIN 55-212-2 (WIN), with or without CB1 or CB2 antagonist. The onset latency of the first swallow and the time intervals between swallows were analyzed. The onset latency and the intervals between swallows were shorter after the intravenous administration of WIN, and the strength of effect of WIN was dose-dependent. Although the intravenous administration of CB1 antagonist prior to intravenous administration of WIN blocked the effect of WIN, the administration of CB2 antagonist did not block the effect of WIN. The microinjection of the CB1 receptor antagonist directly into the nucleus tractus solitarius (NTS) prior to intravenous administration of WIN also blocked the effect of WIN. Immunofluorescence histochemistry was conducted to assess the co-localization of CB1 receptor immunoreactivity to glutamic acid decarboxylase 67 (GAD67) or glutamate in the NTS. CB1 receptor was co-localized more with GAD67 than glutamate in the NTS. These findings suggest that cannabinoids facilitate the swallowing reflex via CB1 receptors. Cannabinoids may attenuate the tonic inhibitory effect of GABA (gamma-aminobuteric acid) neurons in the central pattern generator for swallowing.
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Creating fast flow channels in paper fluidic devices to control timing of sequential reactions.
Lab Chip
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This paper reports the development of a method to control the flow rate of fluids within paper-based microfluidic analytical devices. We demonstrate that by simply sandwiching paper channels between two flexible films, it is possible to accelerate the flow of water through paper by over 10-fold. The dynamics of this process are such that the height of the liquid is dependent on time to the power of 1/3. This dependence was validated using three different flexible films (with markedly different contact angles) and three different fluids (water and two silicon oils with different viscosities). These covered channels provide a low-cost method for controlling the flow rate of fluid in paper channels, and can be added following printing of reagents to control fluid flow in selected fluidic channels. Using this method, we redesigned a previously published bidirectional lateral flow pesticide sensor to allow more rapid detection of pesticides while eliminating the need to run the assay in two stages. The sensor is fabricated with sol-gel entrapped reagents (indoxyl acetate in a substrate zone and acetylcholinesterase, AChE, in a sensing zone) present in an uncovered "slow" flow channel, with a second, covered "fast" channel used to transport pesticide samples to the sensing region through a simple paper-flap valve. In this manner, pesticides reach the sensing region first to allow preincubation, followed by delivery of the substrate to generate a colorimetric signal. This format results in a uni-directional device that detects the presence of pesticides two times faster than the original bidirectional sensors.
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Tools to kill: genome of one of the most destructive plant pathogenic fungi Macrophomina phaseolina.
BMC Genomics
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Macrophomina phaseolina is one of the most destructive necrotrophic fungal pathogens that infect more than 500 plant species throughout the world. It can grow rapidly in infected plants and subsequently produces a large amount of sclerotia that plugs the vessels, resulting in wilting of the plant.
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Expression of TRPV1 channels after nerve injury provides an essential delivery tool for neuropathic pain attenuation.
PLoS ONE
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Increased expression of the transient receptor potential vanilloid 1 (TRPV1) channels, following nerve injury, may facilitate the entry of QX-314 into nociceptive neurons in order to achieve effective and selective pain relief. In this study we hypothesized that the level of QX-314/capsaicin (QX-CAP)--induced blockade of nocifensive behavior could be used as an indirect in-vivo measurement of functional expression of TRPV1 channels. We used the QX-CAP combination to monitor the functional expression of TRPV1 in regenerated neurons after inferior alveolar nerve (IAN) transection in rats. We evaluated the effect of this combination on pain threshold at different time points after IAN transection by analyzing the escape thresholds to mechanical stimulation of lateral mental skin. At 2 weeks after IAN transection, there was no QX-CAP mediated block of mechanical hyperalgesia, implying that there was no functional expression of TRPV1 channels. These results were confirmed immunohistochemically by staining of regenerated trigeminal ganglion (TG) neurons. This suggests that TRPV1 channel expression is an essential necessity for the QX-CAP mediated blockade. Furthermore, we show that 3 and 4 weeks after IAN transection, application of QX-CAP produced a gradual increase in escape threshold, which paralleled the increased levels of TRPV1 channels that were detected in regenerated TG neurons. Immunohistochemical analysis also revealed that non-myelinated neurons regenerated slowly compared to myelinated neurons following IAN transection. We also show that TRPV1 expression shifted towards myelinated neurons. Our findings suggest that nerve injury modulates the TRPV1 expression pattern in regenerated neurons and that the effectiveness of QX-CAP induced blockade depends on the availability of functional TRPV1 receptors in regenerated neurons. The results of this study also suggest that the QX-CAP based approach can be used as a new behavioral tool to detect dynamic changes in TRPV1 expression, in various pathological conditions.
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Evaluation of an arsenic test kit for rapid well screening in Bangladesh.
Environ. Sci. Technol.
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Exposure to arsenic in groundwater via drinking remains unabated for millions of villagers in Bangladesh. Since a blanket testing campaign using test kits almost a decade ago, millions of new wells have been installed but not tested; thus affordable testing is needed. The performance of the Arsenic Econo-Quick (EQ) kit was evaluated by blindly testing 123 wells in Bangladesh and comparing with laboratory measurements; 65 wells were tested twice. A subset of the same 123 wells was also tested using the Hach EZ kit in the field and the Digital Arsenator in the laboratory in Bangladesh. The EQ kit correctly determined the status of 110 (89%) and 113 (92%) out of 123 wells relative to the WHO guideline (10 ?g/L) and the Bangladesh standard (50 ?g/L), respectively. Relative to the WHO guideline, all misclassifications were underestimates for wells containing between >10 and 27 ?g/L As. Relative to the Bangladesh As standard, over- and underestimates were evenly distributed. Given its short reaction time of 10 min relative to the Hach EZ and its lower cost compared to the Arsenator, the EQ kit appears to have several advantages for well testing in Bangladesh and elsewhere.
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Phosphorylation of Na-Cl cotransporter by OSR1 and SPAK kinases regulates its ubiquitination.
Biochem. Biophys. Res. Commun.
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Na-Cl cotransporter (NCC) is phosphorylated in its amino terminus based on salt intake under the regulation of the WNK-OSR1/SPAK kinase cascade. We have observed that total protein abundance of NCC and its apical membrane expression varies in the kidney based on the phosphorylation status. To clarify the mechanism, we examined NCC ubiquitination status in mice fed low, normal and high salt diets, as well as in a model mouse of pseudohypoaldosteronism type II (PHAII) where NCC phosphorylation is constitutively elevated. Low-salt diet decreased NCC ubiquitination, while high-salt diet increased NCC ubiquitination in the kidney, and this was inversely correlated with total and phosphorylated NCC abundance. In the PHAII model, the ubiquitination of NCC in kidney was also lower when compared to that in wild-type littermates. To evaluate the relationship between phosphorylation and ubiquitination of NCC, we expressed wild-type, phospho-deficient and -mimicking NCC in COS7 cells, and the ubiquitination of immunoprecipitated total and biotinylated surface NCC was evaluated. NCC ubiquitination was increased in the phospho-deficient NCC and decreased in phospho-mimicking NCC in both total and surface NCC. Thus, we demonstrated that NCC phosphorylation decreased NCC ubiquitination, which may contribute to the increase of NCC abundance mostly on plasma membranes.
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Prospects and applications of nanobiotechnology: a medical perspective.
J Nanobiotechnology
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Nanobiotechnology is the application of nanotechnology in biological fields. Nanotechnology is a multidisciplinary field that currently recruits approach, technology and facility available in conventional as well as advanced avenues of engineering, physics, chemistry and biology.
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Multiplexed paper test strip for quantitative bacterial detection.
Anal Bioanal Chem
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Rapid, sensitive, on-site detection of bacteria without a need for sophisticated equipment or skilled personnel is extremely important in clinical settings and rapid response scenarios, as well as in resource-limited settings. Here, we report a novel approach for selective and ultra-sensitive multiplexed detection of Escherichia coli (non-pathogenic or pathogenic) using a lab-on-paper test strip (bioactive paper) based on intracellular enzyme (?-galactosidase (B-GAL) or ?-glucuronidase (GUS)) activity. The test strip is composed of a paper support (0.5 × 8 cm), onto which either 5-bromo-4-chloro-3-indolyl-?-D: -glucuronide sodium salt (XG), chlorophenol red ?-galactopyranoside (CPRG) or both and FeCl(3) were entrapped using sol-gel-derived silica inks in different zones via an ink-jet printing technique. The sample was lysed and assayed via lateral flow through the FeCl(3) zone to the substrate area to initiate rapid enzyme hydrolysis of the substrate, causing a change from colorless-to-blue (XG hydrolyzed by GUS, indication of nonpathogenic E. coli) and/or yellow to red-magenta (CPRG hydrolyzed by B-GAL, indication of total coliforms). Using immunomagnetic nanoparticles for selective preconcentration, the limit of detection was ~5 colony-forming units (cfu) per milliliter for E. coli O157:H7 and ~20 cfu/mL for E. coli BL21, within 30 min without cell culturing. Thus, these paper test strips could be suitable for detection of viable total coliforms and pathogens in bathing water samples. Moreover, inclusion of a culturing step allows detection of less than 1 cfu in 100 mL within 8 h, making the paper tests strips relevant for detection of multiple pathogens and total coliform bacteria in beverage and food samples.
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The effect of minocycline on the masticatory movements following the inferior alveolar nerve transection in freely moving rats.
Mol Pain
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To determine the effects of inferior alveolar nerve transection (IAN-X) on masticatory movements in freely moving rats and to test if microglial cells in the trigeminal principal sensory nucleus (prV) or motor nucleus (motV) may be involved in modulation of mastication, the effects of microglial cell inhibitor minocycline (MC) on masticatory jaw movements, microglia (Iba1) immunohistochemistry and the masticatory jaw movements and related masticatory muscle EMG activities were studied in IAN-X rats.
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Chemically homogeneous and thermally reversible oxidation of epitaxial graphene.
Nat Chem
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With its exceptional charge mobility, graphene holds great promise for applications in next-generation electronics. In an effort to tailor its properties and interfacial characteristics, the chemical functionalization of graphene is being actively pursued. The oxidation of graphene via the Hummers method is most widely used in current studies, although the chemical inhomogeneity and irreversibility of the resulting graphene oxide compromises its use in high-performance devices. Here, we present an alternative approach for oxidizing epitaxial graphene using atomic oxygen in ultrahigh vacuum. Atomic-resolution characterization with scanning tunnelling microscopy is quantitatively compared to density functional theory, showing that ultrahigh-vacuum oxidization results in uniform epoxy functionalization. Furthermore, this oxidation is shown to be fully reversible at temperatures as low as 260 °C using scanning tunnelling microscopy and spectroscopic techniques. In this manner, ultrahigh-vacuum oxidation overcomes the limitations of Hummers-method graphene oxide, thus creating new opportunities for the study and application of chemically functionalized graphene.
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Induction of the Swallowing Reflex by Electrical Stimulation of the Posterior Oropharyngeal Region in Awake Humans.
Dysphagia
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We designed an electrical stimulation system to safely and reliably evoke the swallowing reflex in awake humans, and then examined the neural control of reflex swallowing initiated by oropharyngeal stimulation. A custom-made electrode connected to a flexible stainless-steel coil spring tube was introduced into the pharyngeal region through the nasal cavity and placed against the posterior wall of the oropharynx. Surface electrodes placed over the suprahyoid muscles recorded the electromyogram during swallowing. Swallowing reflexes were induced several times by 30 s of repetitive electrical pulse stimulation (intensity: 0.2-1.2 mA, frequency: 10-70 Hz, pulse duration: 1.0 ms). The onset latency of the swallowing reflex was measured over the 10-70 Hz frequency range. In addition, the two time intervals between the first three swallows were measured. The onset latency of the swallowing reflex became shorter as the stimulus frequency increased up to ?30 Hz. Once the frequency exceeded 30 Hz, there was no further reduction in the latency. This finding was consistent with those of previous studies in anesthetized animals. The time intervals between successive swallowing reflexes did not change with increased stimulus frequencies. Furthermore, prolonged stimulation often failed to elicit multiple swallowing reflexes. The frequency dependence of onset latency suggests that temporal summation of pharyngeal afferents is required to activate the medullary swallowing center. This reliable stimulation method may help in rehabilitation of dysphagic patients without causing aspiration.
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The translation elongation factor eEF-1B?1 is involved in cell wall biosynthesis and plant development in Arabidopsis thaliana.
PLoS ONE
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The eukaryotic translation elongation factor eEF-1B?1 (EF1B?) is a guanine nucleotide exchange factor that plays an important role in translation elongation. In this study, we show that the EF1B? protein is localized in the plasma membrane and cytoplasm, and that the transcripts should be expressed in most tissue types in seedlings. Sectioning of the inflorescence stem revealed that EF1B? predominantly localizes to the xylem vessels and in the interfascicular cambium. EF1B? gene silencing in ef? caused a dwarf phenotype with 38% and 20% reduction in total lignin and crystalline cellulose, respectively. This loss-of-function mutant also had a lower S/G lignin monomer ratio relative to wild type plants, but no changes were detected in a gain-of-function mutant transformed with the EF1B? gene. Histochemical analysis showed a reduced vascular apparatus, including smaller xylem vessels in the inflorescence stem of the loss-of-function mutant. Over-expression of EF1B? in an eli1 mutant background restored a WT phenotype and abolished ectopic lignin deposition as well as cell expansion defects in the mutant. Taken together, these data strongly suggest a role for EF1B? in plant development and cell wall formation in Arabidopsis.
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What Does Islam Say About Dieting?
J Relig Health
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Dieting is very important to maintain a healthy and peaceful life. Today, most of the health problems are related with dieting. Thus, the modern health science recommends a number of suggestions regarding dieting for better health such as learning the five basic food groups (grains, vegetables, fruits, dairy, and meat); eating three times a day; decreasing the amount of fat; increasing the amount of fruits, vegetables and grains; including an adequate amount of iron; and avoiding excessive rich food, salt, sugar, and fat. Religion can also play a vital role for our good health and lifestyle. The main concern of this paper was to present an analytical justification regarding what Islam as a religion advocates about dieting along with the modern food and nutrition sciences.
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