Sensitization with Fungal Protease Allergen Establishes Long-Lived, Allergenic Th Cell Memory in the Lung.

Allergic asthma is a chronic inflammatory disease that affects millions of individuals worldwide. Exposure to allergens produced by a variety of otherwise harmless microbes, including fungi, predisposes individuals to immunopathologic disease upon subsequent encounters with allergen. We developed a mouse model that employs a purified protease produced by Aspergillus (Asp f 13) to investigate the contributions of CD4+ Th cells to recurrent lung inflammation. Notably, memory CD4+ T cells enhanced the eosinophil response of sensitized/rechallenged animals. In addition, memory CD4+ T cells maintained allergenic features, including expression of GATA-binding protein 3 and IL-5. Th2 memory T cells persisted in the peribronchiolar interstitium of the lung and expressed markers of tissue residence, such as CD69, CCR8, and IL-33R. Lastly, we identified a peptide epitope contained within Asp f 13 and generated a peptide-MHC class II tetramer. Using these tools, we further demonstrated the durability and exquisite sensitivity of memory T cells in promoting lung eosinophilia. Our data highlight important features of memory T cells that strengthen the notion that memory T cells are principal drivers of eosinophilic disease in murine models of allergic sensitization and episodic airway inflammation.

Magnetically driven molecular orientational ordering in plastic crystals: The case of d-camphor.

Many solid crystals exhibit a structural phase transition where a subset of its ions or entire molecules become orientationally ordered. As to why such ordering occurs remains mostly unresolved. We consider the extremely weak magnetic elements arising from the reorientations of the molecules experiencing mutual resonance to play the chief role. Two new features are identified in d-camphor: (1) the magnetic susceptibility abruptly changes when crossing the order-disorder phase transition at TII-III = 239.8 K during cooling and at TIII-II = 245.2 K during warming and (2) the complex dielectric constant exhibits two successive discontinuities only 0.2 K apart near the critical temperatures when the sweeping rate is only 0.1 K/min. We discuss how the change in entropy associated with order-disorder transitions in plastic crystals represents temporal changes rather than spatial changes in the system. Our findings may be extended to study why many other crystalline solids exhibit orientational ordering and irreversibility.

A non-neutralizing antibody broadly protects against influenza virus infection by engaging effector cells.

Hemagglutinin (HA) is the immunodominant protein of the influenza virus. We previously showed that mice injected with a monoglycosylated influenza A HA (HAmg) produced cross-strain-reactive antibodies and were better protected than mice injected with a fully glycosylated HA (HAfg) during lethal dose challenge. We employed a single B-cell screening platform to isolate the cross-protective monoclonal antibody (mAb) 651 from mice immunized with the HAmg of A/Brisbane/59/2007 (H1N1) influenza virus (Bris/07). The mAb 651 recognized the head domain of a broad spectrum of HAs from groups 1 and 2 influenza A viruses and offered prophylactic and therapeutic efficacy against A/California/07/2009 (H1N1) (Cal/09) and Bris/07 infections in mice. The antibody did not possess neutralizing activity; however, antibody-dependent cellular cytotoxicity and antibody-dependent cellular phagocytosis mediated by natural killer cells and alveolar macrophages were important in the protective efficacy of mAb 651. Together, this study highlighted the significance of effector functions for non-neutralizing antibodies to exhibit protection against influenza virus infection.

Real-Time Observation for Dynamic Oscillation during Self-Assembly and Clearance of Aß42.

The dynamic oscillation implicated in structural heterogeneity during the self-assembly of amyloid peptide 1-42 (Aß42) may play a crucial role in eliciting cellular responses. We developed a real-time monitoring platform to observe an oscillatory non-equilibrium interaction that dominated the Aß42 clearance by neuronal cells during interplay with an oscillator (lipopolysaccharide, LPS). Molecular dynamics studies indicated that the electrostatic and hydrophobic segments of LPS involved in the temporary heteromolecular association and slightly decelerated the intrinsic thermally-induced protein dynamics of Aß42. A bait-specific intervention strategy could temporarily slow down the self-propagation of Aß42 to extend the lifetime of autonomous oscillation and augment Aß42 clearance of neuronal cells. The lifetime increment of oscillation shows a bait concentration-dependent manner to reflect the non-equilibrium binding strength. This relationship may serve as a predictor for Alzheimer's disease drug discovery.

Intracellular Galectin-9 Enhances Proximal TCR Signaling and Potentiates Autoimmune Diseases.

Galectin-9 is a risk gene in inflammatory bowel disease. By transcriptomic analyses of ileal biopsies and PBMCs from inflammatory bowel disease patients, we identified a positive correlation between galectin-9 expression and colitis severity. We observed that galectin-9-deficient T cells were less able to induce T cell-mediated colitis. However, several mouse-based studies reported that galectin-9 treatment induces T cell apoptosis and ameliorates autoimmune diseases in an exogenously modulated manner, indicating a complicated regulation of galectin-9 in T cells. We found that galectin-9 is expressed mainly inside T cells, and its secreted form is barely detected under physiological conditions. Endogenous galectin-9 was recruited to immune synapses upon T cell activation. Moreover, proximal TCR signaling was impaired in galectin-9-deficient T cells, and proliferation of these cells was decreased through an intracellularly modulated manner. Th17 cell differentiation was downregulated in galectin-9-deficient T cells, and this impairment can be rescued by strong TCR signaling. Taken together, these findings suggest that intracellular galectin-9 is a positive regulator of T cell activation and modulates the pathogenesis of autoimmune diseases.

Superconductivity in Pristine 2H_{a}-MoS_{2} at Ultrahigh Pressure.

As a follow-up of our previous work on pressure-induced metallization of the 2H_{c}-MoS_{2} [Chi et al., Phys. Rev. Lett. 113, 036802 (2014)PRLTAO0031-900710.1103/PhysRevLett.113.036802], here we extend pressure beyond the megabar range to seek after superconductivity via electrical transport measurements. We found that superconductivity emerges in the 2H_{a}-MoS_{2} with an onset critical temperature T_{c} of ca. 3 K at ca. 90 GPa. Upon further increasing the pressure, T_{c} is rapidly enhanced beyond 10 K and stabilized at ca. 12 K over a wide pressure range up to 220 GPa. Synchrotron x-ray diffraction measurements evidenced no further structural phase transition, decomposition, and amorphization up to 155 GPa, implying an intrinsic superconductivity in the 2H_{a}-MoS_{2}. DFT calculations suggest that the emergence of pressure-induced superconductivity is intimately linked to the emergence of a new flat Fermi pocket in the electronic structure. Our finding represents an alternative strategy for achieving superconductivity in 2H-MoS_{2} in addition to chemical intercalation and electrostatic gating.

Molecular Dynamics of Hexamethylbenzene at Low Temperatures: Evidence of Unconventional Magnetism Based on Rotational Motion of Protons.

The types of magnetism known to date are all mainly based on contributions from electron motion. We show how rotational motion of protons (H+ ) within the methyl groups in hexamethylbenzene (C6 (CH3 )6 ) also contribute significantly to the magnetic susceptibility. Starting from below 118 K, as the rotational motion of the methyl groups set in, an associated magnetic moment positive in nature due to charge of the protons renders the susceptibility to become anomalously dependent on temperature. Starting from 20 K, the susceptibility diverges with decreasing temperature indicative of spin-spin interactions between methyl groups aligned in a previously unclassified type of anti-ferromagnetic configuration. Complementary dielectric constant measurements also show the existence of magneto-dielectric coupling. Our findings allow for the study of strongly correlated systems that are based on a species that possesses much slower dynamics.

Proton ordering dynamics of H2O ice.

From high precision measurements of the complex dielectric constant of especially prepared samples of H2O, we identify the onset temperatures of the phase transition into and out of ice XI from ice Ih to occur at TIh-XI = 58.9 K and TXI-Ih = 73.4 K. For D2O, TIh-XI = 63.7 K and TXI-Ih = 78.2 K. A triple point is identified to exist at 0.07 GPa and 73.4 K for H2O and 0.08 GPa and 78.2 K for D2O where ices Ih, II and XI coexist. A first order phase transition with kinetic broadening associated with proton ordering dynamics is identified at 100 K.

Backbone NxH compounds at high pressures.

Optical and synchrotron x-ray diffraction diamond anvil cell experiments have been combined with first-principles theoretical structure predictions to investigate mixtures of N2 and H2 up to 55 GPa. Our experiments show the formation of structurally complex van der Waals compounds [see also D. K. Spaulding et al., Nat. Commun. 5, 5739 (2014)] above 10 GPa. However, we found that these NxH (0.5 < x < 1.5) compounds transform abruptly to new oligomeric materials through barochemistry above 47 GPa and photochemistry at pressures as low as 10 GPa. These oligomeric compounds can be recovered to ambient pressure at T < 130 K, whereas at room temperature, they can be metastable on pressure release down to 3.5 GPa. Extensive theoretical calculations show that such oligomeric materials become thermodynamically more stable in comparison to mixtures of N2, H2, and NH3 above approximately 40 GPa. Our results suggest new pathways for synthesis of environmentally benign high energy-density materials. These materials could also exist as alternative planetary ices.

Interaction of daptomycin with lipid bilayers: a lipid extracting effect.

Daptomycin is the first approved member of a new structural class of antibiotics, the cyclic lipopeptides. The peptide interacts with the lipid matrix of cell membranes, inducing permeability of the membrane to ions, but its molecular mechanism has been a puzzle. Unlike the ubiquitous membrane-acting host-defense antimicrobial peptides, daptomycin does not induce pores in the cell membranes. Thus, how it affects the permeability of a membrane to ions is not clear. We studied its interaction with giant unilamellar vesicles (GUVs) and discovered a lipid-extracting phenomenon that correlates with the direct action of daptomycin on bacterial membranes observed in a recent fluorescence microscopy study. Lipid extraction occurred only when the GUV lipid composition included phosphatidylglycerol and in the presence of Ca(2+) ions, the same condition found to be necessary for daptomycin to be effective against bacteria. Furthermore, it occurred only when the peptide/lipid ratio exceeded a threshold value, which could be the basis of the minimal inhibitory concentration of daptomycin. In this first publication on the lipid extracting effect, we characterize its dependence on ions and lipid compositions. We also discuss possibilities for connecting the lipid extracting effect to the antibacterial activity of daptomycin.

Visual detection of copper(II) ions in blood samples by controlling the leaching of protein-capped gold nanoparticles.

We have developed a simple, low-cost, paper-based probe for the selective colorimetric detection of copper ions (Cu(2+)) in aqueous solutions. The bovine serum albumin (BSA)-modified 13.3-nm Au nanoparticle (BSA-Au NP) probe was designed to detect Cu(2+) ions using lead ions (Pb(2+)) and 2-mercaptoethanol (2-ME) as leaching agents in a glycine-NaOH (pH 12.0) solution. In addition, a nitrocellulose membrane (NCM) was used to trap the BSA-Au NPs, leading to the preparation of a nanocomposite film consisting of a BSA-Au NP-decorated membrane (BSA-Au NPs/NCM). The BSA-Au NPs probe operates on the principle that Cu deposition on the surface of the BSA-Au NPs inhibits their leaching ability, which is accelerated by Pb(2+) ions in the presence of 2-ME. Under optimal solution conditions (5 mM glycine-NaOH (pH 12.0), Pb(2+) (50 µM), and 2-ME (1.0 M)), the Pb(2+)/2-ME-BSA-Au NPs/NCM enabled the detection of Cu(2+) at nanomolar concentrations in aqueous solutions by the naked eye with high selectivity (at least 100-fold over other metal ions). In addition, this cost-effective probe allowed for the rapid and simple determination of Cu(2+) ions in not only natural water samples but also in a complex biological sample (in this case, blood sample).

Magnetic Properties of NH4H2PO4 and KH2PO4: Emergence of Multiferroic Salts.

We observe sharp step-down discontinuities in the magnetic susceptibility of NH4H2PO4 and NH4H2PO4-d60 (60% deuterated) along the a- and c-axes occurring exactly at their antiferroelectric transition temperatures. For the case of KH2PO4, less pronounced discontinuities occur at the ferroelectric transition temperature. To explain this, we treat the acid protons as individual oscillators that generate current elements that translate to magnetic forces in near resonance with each other. With decreasing temperature, the resonant forces become more commensurate, which amplifies a disproportionate drop off of two types of magnetic forces to eventually trigger the structural phase transitions. For the case of NH4H2PO4, the associated internal magnetic field appears to aid the NH4+ to order at a higher temperature. At 49 K, a shoulder-like anomaly in both NH4H2PO4 and KH2PO4 is attributed to a possible onset of macroscopic quantum tunneling of protons. Our findings bring forth a new category of intrinsic multiferroic systems.

Characteristics and mechanical properties of titanium-containing diamond like carbon films deposited by cathodic arc evaporation.

Depositions of titanium-containing diamond-like carbon (Ti-DLC) films were conducted by mixing C+ and Ti+ plasma streams originated from cathodic arc plasma sources in argon (Ar). The deposition was processed at Ti target current ranging from 20 Amp to 70 Amp. Film characteristics were investigated using Raman spectroscopy, X-ray photoelectron spectroscopy (XPS). Film microstructures were evaluated using field emission scanning electron microscopy (FEGSEM), an atomic force microscope (AFM), X-ray diffractometry (XRD) and high-resolution transmission electron microscopy (HRTEM). Mechanical properties were investigated by using a nanoindentation tester and ball on disc wear test. Results shows that surface roughness (Ra) of the films ranged between 2.4 and 7.2 nm and roughness increased relative to the increase in Ti target current. The FESEM studies showed that the surface micrographs of Ti-DLC films revealed a cauliflower-like microstructure and the cross-sectional micrograph revealed a snake-skin like structure. HRTEM studies showed that the Ti-DLC films consisted of nano scale TiC particles which were comparable with low angle XRD and XPS results. XPS analysis established that the Ti2p spectrum is present when the Ti target current reaches 30 Amp or higher. Ti concentration increased as the Ti target current was increased. An extremely thin TiO2 layer exists on the top of the Ti-DLC films which was comparable with the AES results. The film thickness which could be deposited for Ti-DLC is much higher than that of conventional DLC films. Nanoindentation tests show that the nanohardness of the films ranging 15-22 GPa, with Er values ranging from 145 to 175 GPa. The wear test demonstrates the friction coefficient of the 420SS substrate, DLC and Ti-DLC films were about 0.8, 0.3 and 0.2, respectively. Obviously, the friction coefficients of the Ti-DLC films were lower than that of the DLC films.

Pharmacokinetics of gastrodin and its metabolite p-hydroxybenzyl alcohol in rat blood, brain and bile by microdialysis coupled to LC-MS/MS.

Gastrodin is a pharmacologically active substance isolated from Gastrodia elata Blume with sedation, anti-convulsion and anti-epilepsy activities. A rapid and sensitive liquid chromatography technique coupled to tandem mass spectrometry (LC-MS/MS) system was developed to determine gastrodin and its metabolite p-hydroxybenzyl alcohol (HBA) in rat blood, brain and bile collected using microdialysis technique. The analytes were separated using a reversed phase column (4.6 mm x 150 mm, 5 microm). The mobile phase for column separation was 30% methanol with a flow rate of 0.6 mL/min. As a post-column addition, 1% ammonium hydroxide solution (in methanol) was additionally pumped via a T-connection using a chromatographic pump (BAS PM-80, USA) at a flow rate of 0.2 mL/min after the column separation. A LC-MS/MS system equipped with a negative electrospray ionization (ESI) source in multiple reaction monitoring (MRM) mode was used to monitor m/z 285.0-->122.9 and m/z 123.0-->105.0 transitions for gastrodin and HBA, respectively. The lower limit of quantification (LLoQ) for gastrodin and HBA were 0.5 and 2 ng/mL, respectively. The calibration curves were linear over the range of 0.5-5,000 ng/mL and 2-1,000 ng/mL for gastrodin and HBA with a coefficient of determination >0.995, respectively. This selective and sensitive method is useful for the determination of gastrodin and HBA and in the pharmacokinetic studies of these compounds.

Modulation of Abnormal Poisson's Ratios and Electronic Properties in Mixed-Valence Perovskite Manganite Films.

Epitaxy and misfit strain imposed by underlying substrates have been intensively used to tailor the microstructure and electronic properties of oxide films, but this approach is largely restricted by commercially limited substrates. In contrast to the conventional epitaxial misfit strains with a positive Poisson's constant, we show here a tunable Poisson's ratio with anomalous values from negative, zero, to positive. This permits effective control over the out-of-plane lattice parameters that strongly correlate the magnetic and transport properties in perovskite mixed-valence La1- xSr xMnO3 thin films. Our results provide an unconventional approach to better modulation and understanding of elastic-mediated microstructures and physical properties of oxide films by engineering the Poisson's ratios.

Bioavailability of salvianolic acid B in conscious and freely moving rats.

Salvianolic acid B is an herbal ingredient isolated from Salvia miltiorrhiza. The aim of this study was to apply an automated blood sampling system coupled to a simple liquid chromatographic system to determine the bioavailability of salvianolic acid B in stress-free rats. The plasma sample (25 microl) was vortex-mixed with 50 microl of internal standard solution (chloramphenicol 10 microg/ml in acetonitrile) to achieve protein precipitation. Salvianolic acid B in the rat plasma was separated using a reversed-phase C18 column (250 mm x 4.6 mm, 5 microm) with a mobile phase of acetonitrile-methanol-20mM NaH(2)PO(4) (adjusted to pH 3.5 with H(3)PO(4)) (20:10:70 v/v/v) containing 0.1mM 1-octanesulfonic acid, and the flow-rate of 1 ml/min. The UV detection wavelength was 286 nm. The concentration-response relationship from the present method indicated linearity over a concentration range of 0.5-200 microg/ml. Intra- and inter-assay precision and accuracy of salvianolic acid B fell well within the predefined limits of acceptability (<15%). The plasma sample of salvianolic acid B was further identified by LC-MS/MS in the negative ion mode using mass transition m/z 358.2 to the product ion m/z 196.9. After salvianolic acid B (100mg/kg, i.v.; 500 mg/kg, p.o.) was given in conscious and freely moving rats, the AUC were 5030+/-565 and 582+/-222 min microg/ml for intravenous (100 mg/kg) and oral (500 mg/kg) doses, respectively. The oral bioavailability of salvianolic acid B in freely moving rats was calculated to be 2.3%.

Determination and pharmacokinetic analysis of salvianolic acid B in rat blood and bile by microdialysis and liquid chromatography.

Salvianolic acid B is an herbal ingredient isolated from Salvia miltiorrhiza. An in vivo microdialysis sampling method coupled to high-performance liquid chromatography has been developed for continuous monitoring of protein-unbound salvianolic acid B in rat blood and bile. Microdialysis probes were inserted into the jugular vein/right atrium and bile duct of Sprague-Dawley rats, and a dose of 100 mg/kg salvianolic acid B was then administered via the femoral vein. Dialysates were collected and directly injected into a liquid chromatographic system. Salvianolic acid B was eluted using a microbore reversed-phase ODS 5 microm (150 mm x 1 mm I.D.) column. Isocratic elution of salvianolic acid B was achieved within 10 min using the liquid chromatographic system. The chromatographic mobile phase consisted of acetonitrile-methanol-20 mM monosodium phosphoric acid (pH 3.5) (10:30:60, v/v/v) containing 0.1 mM 1-octanesulfonic acid with 0.05 ml/min. The wavelength of the UV detector was set at 290 nm. Salvianolic acid B in both blood and bile dialysates was adequately determined using the liquid chromatographic conditions described, although the blank bile pattern was more complex. The retention times of salvianolic acid B in rat blood and bile dialysates were found to be 7.2 min. Peak-areas of salvianolic acid B were linear (r2 > 0.995) over a concentration range of 0.1-50 microg/ml. In vivo recoveries of microdialysis probes of salvianolic acid B in rat blood and bile averaged 22 +/- 2% and 41 +/- 1%, respectively. This study indicates that salvianolic acid B undergoes hepatobiliary excretion.

Measurement of daphnoretin in plasma of freely moving rat by liquid chromatography.

Daphnoretin (7-hydroxyl-6-methoxy-3,7'-dicoumaryl ether), isolated from Wikstronemia indica C.A. Mey. (Thymelaceae), has been reported to induce rabbit platelet aggregation through protein kinase C activation and anticancer activity. In this study, we developed an automated blood sampling system coupled to a simple and sensitive HPLC system to determine plasma concentration of daphnoretin in rats. This method was applied to investigate the pharmacokinetics of daphnoretin in a freely moving rat. Separation of daphnoretin in the rat plasma was achieved using a reversed-phase C18 column (250 mm x 4.6 mm, 5 microm) with a mobile phase of methanol-10 mM NaH2PO4 (adjusted to pH 3.0 with H3PO4) (55:45, v/v), and the flow rate of 1.0 ml/min. The UV detector was set at 345 nm. The automated blood sampling system (DR-II has been applied for blood sampling in a conscious and freely moving rat. The blood samples were centrifuged at 3000 x g for 10 min and the plasma samples were then deproteinized by acetonitrile containing an internal standard (khellin 1 microg/ml). After centrifugation (8000 x g for 10 min), the aliquot of supernatant was injected into the HPLC system for analysis. The concentration-response relationship from the present method indicated linearity over a concentration range of 0.05-1.00 and 1.00-100 microg/ml. Intra- and inter-assay precision and accuracy of daphnoretin fell well within the predefined limits of acceptability (< or = 15%). After daphnoretin (500 mg/kg) was given orally, the maximum concentration was 0.17 microg/ml at the time of 5 min. The oral bioavailability was about 0.15%.

Dielectric Anomaly in Ice near 20 K: Evidence of Macroscopic Quantum Phenomena.

H2O is one of the most important substances needed in sustaining life; but not much is known about its ground state. Here a previously unidentified anomaly is identified in the form of a minimum in the imaginary part of the dielectric constant with respect to temperature near 20 K, while the real part remains monotonic. Isothermal dispersion and absorption measurements show coinciding results. For the case of heavy ice (D2O), no anomaly was identified, confirming an apparent isotope effect. Concerted quantum tunneling of protons is believed to be the main cause behind the reported anomaly. Our findings identify another system that exhibits macroscopic quantum phenomena that rarely occur in nature.

Pressure-driven dome-shaped superconductivity and electronic structural evolution in tungsten ditelluride.

Tungsten ditelluride has attracted intense research interest due to the recent discovery of its large unsaturated magnetoresistance up to 60 T. Motivated by the presence of a small, sensitive Fermi surface of 5d electronic orbitals, we boost the electronic properties by applying a high pressure, and introduce superconductivity successfully. Superconductivity sharply appears at a pressure of 2.5 GPa, rapidly reaching a maximum critical temperature (Tc) of 7 K at around 16.8 GPa, followed by a monotonic decrease in Tc with increasing pressure, thereby exhibiting the typical dome-shaped superconducting phase. From theoretical calculations, we interpret the low-pressure region of the superconducting dome to an enrichment of the density of states at the Fermi level and attribute the high-pressure decrease in Tc to possible structural instability. Thus, tungsten ditelluride may provide a new platform for our understanding of superconductivity phenomena in transition metal dichalcogenides.