Filter Results
44321 results
  • miRNAs are integral for maintaining immune homeostasis and self-tolerance. The influence of miRNAs on T-cell differentiation and plasticity are critical in the development of chronic rejection of transplanted hearts. In this study, we sought to determine whether the knockout of miR-155 affects the development of cardiac allograft vasculopathy (CAV) in a murine model.
    Data Types:
    • Image
    • Tabular Data
    • File Set
  • The construction of beaver dams facilitates a suite of hydrologic, hydraulic, geomorphic, and ecological feedbacks that increase stream complexity and channel–floodplain connectivity that benefit aquatic and terrestrial biota. Depending on where beaver build dams within a drainage network, they impact lateral and longitudinal connectivity by introducing roughness elements that fundamentally change the timing, delivery, and storage of water, sediment, nutrients, and organic matter. While the local effects of beaver dams on streams are well understood, broader coverage network models that predict where beaver dams can be built and highlight their impacts on connectivity across diverse drainage networks are lacking. Here we present a capacity model to assess the limits of riverscapes to support dam-building activities by beaver across physiographically diverse landscapes. We estimated dam capacity with freely and nationally-available inputs to evaluate seven lines of evidence: (1) reliable water source, (2) riparian vegetation conducive to foraging and dam building, (3) vegetation within 100m of edge of stream to support expansion of dam complexes and maintain large colonies, (4) likelihood that channel-spanning dams could be built during low flows, (5) the likelihood that a beaver dam is likely to withstand typical floods, (6) a suitable stream gradient that is neither too low to limit dam density nor too high to preclude the building or persistence of dams, and (7) a suitable river that is not too large to restrict dam building or persistence. Fuzzy inference systems were used to combine these controlling factors in a framework that explicitly also accounts for model uncertainty. The model was run for 40,561km of streams in Utah, USA, and portions of surrounding states, predicting an overall network capacity of 356,294 dams at an average capacity of 8.8dams/km. We validated model performance using 2852 observed dams across 1947km of streams. The model showed excellent agreement with observed dam densities where beaver dams were present. Model performance was spatially coherent and logical, with electivity indices that effectively segregated capacity categories. That is, beaver dams were not found where the model predicted no dams could be supported, beaver avoided segments that were predicted to support rare or occasional densities, and beaver preferentially occupied and built dams in areas predicted to have pervasive dam densities. The resulting spatially explicit reach-scale (250m long reaches) data identifies where dam-building activity is sustainable, and at what densities dams can occur across a landscape. As such, model outputs can be used to determine where channel–floodplain and wetland connectivity are likely to persist or expand by promoting increases in beaver dam densities.
    Data Types:
    • Software/Code
    • Image
    • Tabular Data
    • Document
    • File Set
  • Reaction of fac-[RuCl3(NO)(P–N)] (1) with the triarylphosphines PR3 in MeOH allows for isolation of the monocationic Ru(II) complexes [RuCl2(NO)(P–N)(PR3)]PF6; P–N=o-diphenylphosphino-N,N-dimethylaniline, and R=p-MeO-C6H4 (complex 2), p-Me-C6H4 (3), Ph (4), and p-F-C6H4 (5). The complexes were characterized by elemental analysis, 31P{1H}, 1H NMR and IR spectroscopies, ESI-MS, CV, and X-ray structural data for complexes 3–5. The 31P{1H} spectra display two doublets with 2Jpp values consistent with cis P-atoms. The ESI-MS spectra reveal the molecular ion [RuCl2(NO)(P–N)(PR3)]+ and the fragmentation ions [M−PR3]+, [M−PR3−Cl]+, and [M−PR3−2Cl]+. CV data show a one-electron, quasi-reversible reduction process centred at the Ru–NO unit that depends on the pKa of the PR3. The IR spectra reveal νNO bands for coordinated NO+. A known, empirical inverse correlation between the δP value and the Ru–P bond length of the P–N ligand that exists for a series of cis- and trans-RuX2(L)(P–N)(PR3) complexes (X=Cl or Br), where L is a range of small molecules, is extended with L=NO+ and now covers the respective ranges of about 30–80ppm and 2.39–2.17Å.
    Data Types:
    • Image
    • Tabular Data
    • Document
    • File Set
  • A series of soluble in common organic solvents nickel(II) 14,28-dialkoxy-substituted phthalocyanines is synthesized by reaction of nickel acetate tetrahydrate with 1,2-dicyanobenzene in the presence of an alcohol under solvothermal conditions. Single crystal X-ray diffraction analyses reveal that the two alkoxy groups are added in a syn-conformation mode in all the studied cases. The use of microwave irradiation leads to decomposition of the nickel(II) 14,28-dialkoxy-substituted phthalocyanines.
    Data Types:
    • Image
    • Tabular Data
    • Document
    • File Set
  • A novel bis(pyrazolyl)methane ligand bearing alkyne substituents (CCtBu) in the C-4 position of the pyrazole rings has been synthesized together with its Pd(II) dichloride and diacetate complexes. Both the Pd(II) complexes are monomeric species stable in the solid state and in organic solution. The crystal structure of the Pd(II) dichloride complex displays a slightly distorted square-planar geometry and the molecules tend to form dimers associated through π–π stacking interactions between the pyrazolyl rings. The in vitro antitumor activities of the free ligand and of its corresponding Pd(II) complexes toward some human cancer cell lines, such as HeLa, SHSY-5Y and K562, have shown to be lower than cisplatin but with a better response in comparison to their parent free ligand.
    Data Types:
    • Image
    • Tabular Data
    • File Set
  • Herein we report that oxalate serves as a template in the formation of di-zinc macrocycles featuring bis(imino)pyridine chelating units linked by p-xylylene or m-xylylenes linkers. The resulting complexes were characterized by NMR spectroscopy, mass spectrometry, elemental analysis, and X-ray crystallography. NMR spectroscopy indicates highly symmetrical (C2v or D2h) structures of the macrocyclic complexes in solution. Solid-state structures, determined by X-ray crystallography (obtained only for the m-xylylene bridged macrocycles), revealed hexa-coordinate zinc centers with μ2-κ2,κ2-bound oxalate, meridional NNN chelates, and an additional ligand (DMF or H2O) bound to zinc centers. Cyclic voltammetry demonstrates series of reductions associated with the redox-active bis(imino)pyridine chelates; no oxidation was observed up to 1V. We have attempted to extract oxalate from the macrocycle using calcium bromide, ethylenediaminetetraacetic acid (EDTA), trimethyl silyl chloride (TMSCl), acetic acid, or hydrochloric acid (HCl). Of the above, EDTA, TMSCl, acetic acid, and HCl in ether failed to remove oxalate or to form a new isolable product, while calcium bromide transformed μ2-κ2,κ2-bound oxalate into the μ2-κ1,κ2-bound form. The addition of aqueous HCl enables observation of the oxalate-free complex by mass spectrometry as one of the major products.
    Data Types:
    • Image
    • Document
    • File Set
  • Taenia solium is an endemic parasite in India which occurs in two forms in humans: cysticercosis (infection of soft tissues) and taeniosis (intestinal infection). Neurocysticercosis (NCC) is the most severe form of cysticercosis in which cysts develop in the central nervous system. This study was conducted to estimate health and economic impact due to human NCC-associated active epilepsy in India. Input data were sourced from published research literature, census data and other official records. Economic losses due to NCC-associated active epilepsy were estimated based on cost of treatment, hospitalisation and severe injury as well as loss of income. The disability-adjusted life years (DALYs) due to NCC were estimated by combining years of life lost due to early death and the number of years compromised due to disability taking the disease incidence into account. DALYs were estimated for five age groups, two genders and four regions, and then combined. To account for uncertainty, probability distributions were used for disease incidence data and other input parameters. In addition, sensitivity analyses were conducted to determine the impact of certain input parameters on health and economic estimates. It was estimated that in 2011, human NCC-associated active epilepsy caused an annual median loss of Rupees 12.03 billion (uncertainty interval [95% UI] Rs. 9.16–15.57 billion; US $ 185.14 million) with losses of Rs. 9.78 billion (95% UI Rs. 7.24–13.0 billion; US $ 150.56 million) from the North and Rs. 2.22 billion (95% UI Rs. 1.58–3.06 billion; US $ 34.14 million) from the South. The disease resulted in a total of 2.10 million (95% UI 0.99–4.10 million) DALYs per annum without age weighting and time discounting with 1.81 million (95% UI 0.84–3.57 million) DALYs from the North and 0.28 million (95% UI 0.13–0.55 million) from the South. The health burden per thousand persons per year was 1.73 DALYs (95% UI 0.82–3.39). The results indicate that human NCC causes significant health and economic impact in India. Programs for controlling the disease should be initiated to reduce the socio-economic impact of the disease in India.
    Data Types:
    • Image
    • Tabular Data
    • File Set
  • Surface-tension-driven capillary systems (CSs) enable self-powered delivery of samples and reagents for bioassays and thus are especially suitable for point-of-care applications. Current silicon and polymer based CSs require extensive work in professional cleanroom for the fabrication of either the silicon device itself or the micromold for polymer processing. In this work, we fabricated a PEG-based CS in a one-step photopolymerization process without the requirement of any cleanroom work. Water, buffer and serum can flow autonomously in this CS and the liquid flow rate can be tuned by modification with surfactant solution of different concentrations. We further integrated an antibody-coated microbead array into this CS for the autonomous immunoassay of two tumor markers, prostate specific antigen (PSA) and human chorionic gonadotropin (hCG), in serum samples with a total assay time of less than 10min. The detection limits for the two tumor markers were at sub-nanogram per milliliter range which is lower than their clinical threshold concentrations for cancer diagnosis. Moreover, simultaneous and multiplex detection of the two tumor markers was also achieved by using spatially encoded microbeads. This low cost and easy-fabricated CS enables fast, multiplex and autonomous immunoassay for protein markers and has the potential to be applied for point-of-care diagnostics on real clinical samples.
    Data Types:
    • Image
    • Video
    • Tabular Data
    • Document
  • The effects of building orientation and post-fabrication heat treatment (solution annealing plus peak-aging) on fully-reversed strain-controlled fatigue behavior of 17-4 precipitation hardening (PH) stainless steel (SS) fabricated via Selective Laser Melting (SLM) is investigated. For this particular alloy, post-SLM heat treatment was found to be necessary in order to improve its tensile strength and fatigue behavior in low cycle fatigue (LCF), where the effects of microstructural impurities are less pronounced. However, the selected heat treatment was found to have detrimental influence on the SLM 17-4 PH SS high cycle fatigue (HCF) performance. The heat treatment resulted in precipitation hardening, allowing the SLM parts to become more sensitive to impurities in HCF, where the crack initiation stage dominates the total fatigue lifetime. Building orientation played a significant role on fatigue behavior in both LCF and HCF, owing to the relative orientation of deposited layers with respect to applied load. Un-melted regions (i.e. inter-layer cavities/voids), resulting from insufficient fusion or low laser penetration depth, were found to be the most detrimental type of defects on fatigue strength of SLM 17-4 PH SS due to their relatively large size and irregular shape. These specific regions that formed during fabrication of vertically-orientated samples were more detrimental than those of horizontally-built ones as they provided more stress concentration under loading, leading to lower fatigue strength. Although the process parameters were optimized based on maximizing density, the results of this study imply that this criterion is not sufficient for improving fatigue behavior, as the split-shaped un-melted regions, containing a large area with small volume, cannot be taken into account through conventional density measurements.
    Data Types:
    • Image
    • Video
    • Tabular Data
  • Hierarchically porous anatase TiO2 microspheres composited with carbonaceous species (TCS) have been successfully fabricated by a one-step template-free solvothermal method, combined with subsequent low temperature dried process. In this configuration, the TCS microspheres are constructed by the interconnected porous nanosheets, which are further assembled with abundant nanoparticles and carbonaceous species. Such composite microspheres possess a large specific surface area of 337 m2 g–1, uniform mesopores of 3.37 nm and high total pore volumes of 0.275 cm3 g–1. The materials exhibit the enhanced photocatalytic properties and stability for degradation of rhodamine B (RhB) under visible-light irradiation. The enhanced photocatalytic degradation performance may be ascribed to their abundant porous structure, large specific surface area and the unique assist-function of the carbonaceous species.
    Data Types:
    • Image
    • Tabular Data
    • File Set
6