Enzyme Aided Peeling and Membrane Removal of Local Mandarins (Citrus Suhuiensis)

A combination of pectinases and cellulases are able to selectively alter the albedo and segment membrane structure of citrus fruits and, hence, aid the removal of the peel, adhering albedo layer and also the segment membrane. This study was camed out to determine the optimum conditions needed to peel local mandarins using pectinases (PeelzymB IV, Novozyme, Switzerland) and cellulases (CelluclastB 1 SL, Novozyme, Switzerland). The experiment variables were enzyme concentration, vacuum pressure and vacuum infusion time. In the first part of the experiment, the local mandarins were first scored fiom stem end to the blossom end followed by immersion in 1000 ml of enzyme solution at a set vacuum pressure and ambient temperature (27 f 1 OC). Only one parameter was varied in any one experiment. The latter part of the experiment was carried out using Response Surface Methodology (RSM) to determine the optimum combinations of enzyme concentration, vacuum pressure and vacuum infusion time to aid enzymatic segment membrane removal. Echip software was employed in the experimental design, calculate equations and statistical analysis. PeelzymB IV at 0.4 % vlw, 650 mm Hg vacuum and 16 minutes of vacuum time were found to be optimal for peel removal.The enzyme-peeled h i t s were judged by the panellists using three different sensory tests to ascertain its appeal to consumers. A significant (P< 0.05) difference between enzyme-peeled and hand-peeled segments was found, with the panelists preferring the enzyme-peeled segments. Celluclast@ 1.5L at 4.52 % vlw, vacuum pressure at 370 mm Hg for 9 minutes was found to be optimal. After segment membrane removal, the membraneless local mandarin segments were then placed in different concentrations of sugar solutions to gauge consumer acceptance. Different sugar concentrations were used to emulate commercially available canned mandarin segments. Although varying concentrations of sugar solutions were used, the colour, odour, firmness, presence of adhering segment membrane and segment integrity were not affected as there was no significant (P<0.05) difference among the samples. It was also observed that local mandarins stored in 15 %rix was the preferred sugar concentration. As an overview, enzyme-peeled segments were found to be much more appealing as it had a much more intense orange colour, was firm with no loss of segment integrity, hence, was very well accepted by the panelists. Thus, enzyme aided peeling has a great potential as an alternative method to replace conventional methods of peeling

The value of kinetic glomerular filtration rate estimation on medication dosing in acute kidney injury.

BackgroundIn acute kidney injury (AKI), medication dosing based on Cockcroft-Gault creatinine clearance (CrCl) or Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) estimated glomerular filtration rates (eGFR) are not valid when serum creatinine (SCr) is not in steady state. The aim of this study was to determine the impact of a kinetic estimating equation that incorporates fluctuations in SCrs on drug dosing in critically ill patients.MethodsWe used data from participants enrolled in the NIH Acute Respiratory Distress Syndrome Network Fluid and Catheters Treatment Trial to simulate drug dosing category changes with the application of the kinetic estimating equation developed by Chen. We evaluated whether kinetic estimation of renal function would change medication dosing categories (≥60, 30-59, 15-29, and &lt;15mL/min) compared with the use of CrCl or CKD-EPI eGFR.ResultsThe use of kinetic CrCl and CKD-EPI eGFR resulted in a large enough change in estimated renal function to require medication dosing recategorization in 19.3% [95 CI 16.8%-21.9%] and 23.4% [95% CI 20.7%-26.1%] of participants, respectively. As expected, recategorization occurred more frequently in those with AKI. When we examined individual days for those with AKI, dosing discordance was observed in 8.5% of total days using the CG CrCl and 10.2% of total days using the CKD-EPI equation compared with the kinetic counterparts.ConclusionIn a critically ill population, use of kinetic estimates of renal function impacted medication dosing in a substantial proportion of AKI participants. Use of kinetic estimates in clinical practice should lower the incidence of medication toxicity as well as avoid subtherapeutic dosing during renal recovery

Development of LSPR-based optical biosensors for the label-free detection of biomolecular interactions in high-density peptide arrays

Peptide or protein chips which can track hundreds or thousands of distinct proteins from a blood or urine sample at a single step are highly desired. It will allow the diagnosis of diseases in their formative, treatable stages just by detecting proteins that are markers for these specific diseases. To simultaneously and efficiently detect where blood´s proteins bind on the grid, label-free detection methods are favorable in order to reduce time and cost demands and facilitate the detection of low-affinity binding events. In this work, a label-free biosensor based on localized surface plasmon resonance (LSPR) was developed and specifically optimized regarding its application as a solid substrate in the synthesis of high-density peptide arrays, and in the detection of molecular interactions occurring on the sensor surface. Three main issues which are crucial in achieving this goal have been covered in this work: (i) development and optimization of the LSPR biosensor, (ii) Synthesis of a protein resistant layer on the LSPR biosensor, (iii) Label-free detection of biomolecular interactions on the polymer coated LSPR biosensors. For this purpose, a LSPR-based biosensor was first constructed. It consists of two gold layers and an intermediate dielectric layer in-between. The LSPR biosensor shows several pronounced resonance peaks in the UV-visible region of the electromagnetic spectrum, which are highly sensitive to changes in the refractive index of the surrounding medium. The LSPR biosensor was optimized in terms of plasmon resonance line shape, optical homogeneity, and sensitivity to facilitate its application in the label-free detection of biomolecular interactions in array format. In a second step, a poly(ethylene glycol) based polymer was synthesized on the sensor surface at mild reaction conditions by using Atom Transfer Radical Polymerization (ATRP). The sensor was first coated with a silica gel to stabilize the sensor and provide a sufficiently high number of functional groups. ATRP initiators were immobilized on the silica gel surface in 2 steps by silanization and esterification to enhance the coupling efficiency. Subsequently, polymerization was carried out with oligo(ethylene glycol) methacrylate (OEGMA) as the monomer resulting in a poly(ethylene glycol) methacrylate (PEGMA) polymer film. In the second approach, a graft copolymer film was synthesized on the sensor surface with methyl methacrylate (MMA) as the diluting monomer in order to reduce the protein-resistance of the sensor coating and further enhance the sensor stability. Graft copolymer films with 10% PEGMA/ 90% MMA and a thickness of 50-60 nm were successfully synthesized by setting the polymerization time between 9.5 and 10.5 hours. This thickness regime is required to ensure a high-loading of amino functional groups, which serve as the starting point for the subsequent peptide array synthesis. At the same time, this film thickness does not exceed the surface sensitivity regime of the LSPR biosensor. To test the performance of the LSPR biosensor, an array of fluorescent-labeled antibodies was formed on its surface by a spotting robot. The LSPR image displays an array of spots which corresponds to the fluorescence image. Moreover, the quantity of antibody bound to the sensor surface was correctly predicted based on the measured wavelength shifts in the quadrupole regime and a mass sensitivity factor known from literature. This shows that the LSPR biosensor described in this thesis has the potential to allow the detection of molecular interactions in a miniaturized array format in a quantitative manner. In the final part of this thesis, the polymer-coated LSPR biosensor was successfully utilized as the solid substrate in the synthesis of a peptide array via a novel laser printing technique developed at the Cancer Research Center Heidelberg (DKFZ). An array with 9x20 variants of hemagglutinin/HA (YPYDVPDYA) epitope was synthesized on a polymer-coated LSPR biosensor and incubated with IR-dye conjugated specific antibody. The LSPR image was generated by evaluating the wavelength shift in the octapole resonance peak and has successfully displayed the entire peptide array formed on the sensor surface. In a separate study, the potential of single, small particles for biosensing applications in miniaturized format was investigated. Whispering gallery modes (WGM) of fluorescence-doped sulfonated polystyrene (PS) particles with a diameter of 2 µm were studied with respect to their resonance shift after adsorption of polyelectrolyte multilayers. The resonance shifts were plotted as a function of the film thickness and a slope of 0.038 nm/ Å was obtained from a linear fit to the experimental data. This sensitivity factor can be translated into a detection limit of 3 fg by assuming a spectral resolution of 0.1 nm and a polyelectrolyte mass density17 of 0.81 g/cm3

Regularized Learning for Domain Adaptation under Label Shifts

We propose Regularized Learning under Label shifts (RLLS), a principled and a practical domain-adaptation algorithm to correct for shifts in the label distribution between a source and a target domain. We first estimate importance weights using labeled source data and unlabeled target data, and then train a classifier on the weighted source samples. We derive a generalization bound for the classifier on the target domain which is independent of the (ambient) data dimensions, and instead only depends on the complexity of the function class. To the best of our knowledge, this is the first generalization bound for the label-shift problem where the labels in the target domain are not available. Based on this bound, we propose a regularized estimator for the small-sample regime which accounts for the uncertainty in the estimated weights. Experiments on the CIFAR-10 and MNIST datasets show that RLLS improves classification accuracy, especially in the low sample and large-shift regimes, compared to previous methods

Increased Expression of Cytotoxic T-Lymphocyte-Associated Protein 4 by T Cells, Induced by B7 in Sera, Reduces Adaptive Immunity in Patients With Acute Liver Failure.

BACKGROUND & AIMS: Patients with acute liver failure (ALF) have defects in innate immune responses to microbes (immune paresis) and are susceptible to sepsis. Cytotoxic T-lymphocyte-associated protein 4 (CTLA4), which interacts with the membrane receptor B7 (also called CD80 and CD86), is a negative regulator of T-cell activation. We collected T cells from patients with ALF and investigated whether inhibitory signals down-regulate adaptive immune responses in patients with ALF. METHODS: We collected peripheral blood mononuclear cells from patients with ALF and controls from September 2013 through September 2015 (45 patients with ALF, 20 patients with acute-on-chronic liver failure, 15 patients with cirrhosis with no evidence of acute decompensation, 20 patients with septic shock but no cirrhosis or liver disease, and 20 healthy individuals). Circulating CD4+ T cells were isolated and analyzed by flow cytometry. CD4+ T cells were incubated with antigen, or agonist to CD3 and dendritic cells, with or without antibody against CTLA4; T-cell proliferation and protein expression were quantified. We measured levels of soluble B7 molecules in supernatants of isolated primary hepatocytes, hepatic sinusoidal endothelial cells, and biliary epithelial cells from healthy or diseased liver tissues. We also measured levels of soluble B7 serum samples from patients and controls, and mice with acetaminophen-induced liver injury using enzyme-linked immunosorbent assays. RESULTS: Peripheral blood samples from patients with ALF had a higher proportion of CD4+ CTLA4+ T cells than controls; patients with infections had the highest proportions. CD4+ T cells from patients with ALF had a reduced proliferative response to antigen or CD3 stimulation compared to cells from controls; incubation of CD4+ T cells from patients with ALF with an antibody against CTLA4 increased their proliferative response to antigen and to CD3 stimulation, to the same levels as cells from controls. CD4+ T cells from controls up-regulated expression of CTLA4 after 24-48 hours culture with sera from patients with ALF; these sera were found to have increased concentrations of soluble B7 compared to sera from controls. Necrotic human primary hepatocytes exposed to acetaminophen, but not hepatic sinusoidal endothelial cells and biliary epithelial cells from patients with ALF, secreted high levels of soluble B7. Sera from mice with acetaminophen-induced liver injury contained high levels of soluble B7 compared to sera from mice without liver injury. Plasma exchange reduced circulating levels of soluble B7 in patients with ALF and expression of CTLA4 on T cells. CONCLUSIONS: Peripheral CD4+ T cells from patients with ALF have increased expression of CTLA4 compared to individuals without ALF; these cells have a reduced response to antigen and CD3 stimulation. We found sera of patients with ALF and from mice with liver injury to have high concentrations of soluble B7, which up-regulates CTLA4 expression by T cells and reduces their response to antigen. Plasma exchange reduces levels of B7 in sera from patients with ALF and might be used to restore antimicrobial responses to patients

Quasiparticle characteristics of the weakly ferromagnetic Hund's metal MnSi

Hund's metals are multi-orbital systems with $3d$ or $4d$ electrons exhibiting both itinerant character and local moments, and they feature Kondo-like screenings of local orbital and spin moments, with suppressed coherence temperature driven by Hund's coupling $J_H$. They often exhibit magnetic order at low temperature, but how the interaction between the Kondo-like screening and long-range magnetic order is manifested in the quasiparticle spectrum remains an open question. Here we present spectroscopic signature of such interaction in a Hund's metal candidate MnSi exhibiting weak ferromagnetism. Our photoemission measurements reveal renormalized quasiparticle bands near the Fermi level with strong momentum dependence: the ferromagnetism manifests through possibly exchange-split bands (Q1) below $T_C$ , while the spin/orbital screenings lead to gradual development of quasiparticles (Q2) upon cooling. Our results demonstrate how the characteristic spin/orbital coherence in a Hund's metal could coexist and compete with the magnetic order to form a weak itinerant ferromagnet, via quasiparticle bands that are well separated in momentum space and exhibit distinct temperature dependence. Our results imply that the competition between the spin/orbital screening and the magnetic order in a Hund's metal bears intriguing similarity to the Kondo lattice systems.Comment: accepted by PR

Ground Water Chemistry Changes before Major Earthquakes and Possible Effects on Animals

Prior to major earthquakes many changes in the environment have been documented. Though often subtle and fleeting, these changes are noticeable at the land surface, in water, in the air, and in the ionosphere. Key to understanding these diverse pre-earthquake phenomena has been the discovery that, when tectonic stresses build up in the Earth’s crust, highly mobile electronic charge carriers are activated. These charge carriers are defect electrons on the oxygen anion sublattice of silicate minerals, known as positive holes, chemically equivalent to O− in a matrix of O2−. They are remarkable inasmuch as they can flow out of the stressed rock volume and spread into the surrounding unstressed rocks. Travelling fast and far the positive holes cause a range of follow-on reactions when they arrive at the Earth’s surface, where they cause air ionization, injecting massive amounts of primarily positive air ions into the lower atmosphere. When they arrive at the rock-water interface, they act as •O radicals, oxidizing water to hydrogen peroxide. Other reactions at the rock-water interface include the oxidation or partial oxidation of dissolved organic compounds, leading to changes of their fluorescence spectra. Some compounds thus formed may be irritants or toxins to certain species of animals. Common toads, Bufo bufo, were observed to exhibit a highly unusual behavior prior to a M6.3 earthquake that hit L’Aquila, Italy, on April 06, 2009: a few days before the seismic event the toads suddenly disappeared from their breeding site in a small lake about 75 km from the epicenter and did not return until after the aftershock series. In this paper we discuss potential changes in groundwater chemistry prior to seismic events and their possible effects on animals

Nox2-deficient Tregs improve heart transplant outcomes via their increased graft recruitment and enhanced potency.

Nox2 is a ROS-generating enzyme, deficiency of which increases suppression by Tregs in vitro and in an in vivo model of cardiac remodelling. Since Tregs have emerged as a candidate therapy in autoimmunity and transplantation, we hypothesised that Nox2 deficiency in Tregs in recipient mice may improve outcomes in a heart transplant model. A novel B6129 mouse model with Treg-targeted Nox2 deletion (Nox2fl/flFoxP3Cre+) was generated and transplanted with hearts from CB6F1 donors. As compared to littermate controls, Nox2fl/flFoxP3Cre+ mice had lower plasma levels of alloantibodies and troponin-I, reduced levels of IFN-γ in heart allograft homogenates and diminished cardiomyocyte necrosis and allograft fibrosis. Single cell analyses of allografts revealed higher absolute numbers of Tregs and lower CD8+ T cell infiltration in Nox2-deficient recipients compared to Nox2-replete mice. Mechanistically, in addition to a greater suppression of CD8+CD25- T effector cell proliferation and IFN-γ production, Nox2-deficient Tregs expressed higher levels of CCR4 and CCR8, driving cell migration to allografts; this was associated with increased expression of miR214-3p. These data indicate that Nox2 deletion in Tregs enhances their suppressive ability and migration to heart allografts. Therefore, Nox2 inhibition in Tregs may be a useful approach to improve their therapeutic efficacy

The preparation of graft copolymers of cellulose and cellulose derivatives using ATRP under homogeneous reaction conditions

In this comprehensive review, we report on the preparation of graft-copolymers of cellulose and cellulose derivatives using atom transfer radical polymerization (ATRP) under homogeneous conditions. The review is divided into four sections according to the cellulosic material that is graft-copolymerised; (i) cellulose, (ii) ethyl cellulose, (iii) hydroxypropyl cellulose and (iv) other cellulose derivatives. In each section, the grafted synthetic polymers are described as well as the methods used for ATRP macro-initiator formation and graft-copolymerisation. The physical properties of the graft-copolymers including their self-assembly in solution into nanostructures and their stimuli responsive behaviour are described. Potential applications of the self-assembled graft copolymers in areas such as nanocontainers for drug delivery are outline