Handheld Co-Axial Bioprinting: Application to in situ surgical cartilage repair

Three-dimensional (3D) bioprinting is driving major innovations in the area of cartilage tissue engineering. Extrusion-based 3D bioprinting necessitates a phase change from a liquid bioink to a semi-solid crosslinked network achieved by a photo-initiated free radical polymerization reaction that is known to be cytotoxic. Therefore, the choice of the photocuring conditions has to be carefully addressed to generate a structure stiff enough to withstand the forces phisiologically applied on articular cartilage, while ensuring adequate cell survival for functional chondral repair. We recently developed a handheld 3D printer called Biopen . To progress towards translating this freeform biofabrication tool into clinical practice, we aimed to define the ideal bioprinting conditions that would deliver a scaffold with high cell viability and structural stiffness relevant for chondral repair. To fulfill those criteria, free radical cytotoxicity was confined by a co-axial Core/Shell separation. This system allowed the generation of Core/Shell GelMa/HAMa bioscaffolds with stiffness of 200KPa, achieved after only 10seconds of exposure to 700mW/cm2 of 365nm UV-A, containing \u3e90% viable stem cells that retained proliferative capacity. Overall, the Core/Shell handheld 3D bioprinting strategy enabled rapid generation of high modulus bioscaffolds with high cell viability, with potential for in situ surgical cartilage engineering

Herbarium X-ray fluorescence screening for nickel, cobalt and manganese hyperaccumulator plants in the flora of Sabah (Malaysia, Borneo Island)

Sabah (Malaysia) on the Island of Borneo has high plant diversity (>8000 species) occurring on a wide range of soils, including ultramafic soils which are known to host hyperaccumulator plants. In this study a new approach (“Herbarium X-ray Fluorescence Ionomics”) was used to obtain elemental data from herbarium specimens using non-destructive X-ray Fluorescence spectroscopy analysis. In total ~7300 specimens were thus analysed for nickel, cobalt, and manganese concentrations at the Herbarium of the Forest Research Centre (FRC) in Sepilok, Sabah. The measurements led to recording a total of 759 specimens (originating from 17 families in 30 genera and 74 species) as trace element hyperaccumulators, including 28 nickel hyperaccumulator species (in 10 families, 17 genera), 12 cobalt hyperaccumulator species (in 3 families, 7 genera), and 51 manganese hyperaccumulator species (in 12 families, 24 genera). The outcomes of this research demonstrate that handheld XRF is highly useful approach for hyperaccumulator plant discovery in herbarium collections that has the potential to add vast numbers of hyperaccumulating taxa to the global inventory

The HIF1α/JMY pathway promotes glioblastoma stem-like cell invasiveness after irradiation

Human glioblastoma (GBM) is the most common primary malignant brain tumor. A minor subpopulation of cancer cells, known as glioma stem-like cells (GSCs), are thought to play a major role in tumor relapse due to their stem cell-like properties, their high resistance to conventional treatments and their high invasion capacity. We show that ionizing radiation specifically enhances the motility and invasiveness of human GSCs through the stabilization and nuclear accumulation of the hypoxia-inducible factor 1α (HIF1α), which in turn transcriptionally activates the Junction-mediating and regulatory protein (JMY). Finally, JMY accumulates in the cytoplasm where it stimulates GSC migration via its actin nucleation-promoting activity. Targeting JMY could thus open the way to the development of new therapeutic strategies to improve the efficacy of radiotherapy and prevent glioma recurrence.The authors thank members of the LRP for helpful discussions and are indebted to V. Barroca and the staff of the animal facilities and to N. Deschamps and J. Baijer for cell sorting. We also thanks I. Naguibneva for the gift of the pTRIP shHIF1α plasmid. MS is the recipient of a doctoral fellowship from the Ministère de la Recherche. This work was supported by grants from CEA (Segment Radiobiologie), La Ligue contre le Cancer (Comité d’Ile de France), Electricité de France (EDF), Fondation de France (N° Engt: 2013-00042632) and Ramón y Cajal program (RYC-2013-13450)

UV-driven Chemistry as a Signpost for Late-stage Planet Formation

The chemical reservoir within protoplanetary disks has a direct impact on planetary compositions and the potential for life. A long-lived carbon-and nitrogen-rich chemistry at cold temperatures (<=50K) is observed within cold and evolved planet-forming disks. This is evidenced by bright emission from small organic radicals in 1-10 Myr aged systems that would otherwise have frozen out onto grains within 1 Myr. We explain how the chemistry of a planet-forming disk evolves from a cosmic-ray/X-ray-dominated regime to an ultraviolet-dominated chemical equilibrium. This, in turn, will bring about a temporal transition in the chemical reservoir from which planets will accrete. This photochemical dominated gas phase chemistry develops as dust evolves via growth, settling and drift, and the small grain population is depleted from the disk atmosphere. A higher gas-to-dust mass ratio allows for deeper penetration of ultraviolet photons is coupled with a carbon-rich gas (C/O > 1) to form carbon-bearing radicals and ions. This further results in gas phase formation of organic molecules, which then would be accreted by any actively forming planets present in the evolved disk.Comment: Accepted to Nature Astronomy, Published Dec 8th 202

Ursinus College Alumni Journal, August 1967

Exposure \u2767 Ursinus • Viewpoint at commencement time: Means to an end; Toward freedom; Liberal morality; Open-minded attitude; Quality vs. quantity • From the President • What makes Suzy a language dud? • The paradox of urbia: an interview • Negro voices of the city • Springtime was alumni time • Dr. Myers wins alumni award • Dr. Wessel speaks on urbia • Alumni giving climbs in 1967 • Campus clippings: Collegeville area grows; Staigers tour world; Color film; Miss congeniality; New Board members; Placement service; Schultze promoted; Humble gift; Include Ursinus in your will • Sporting scene: Tennis; Baseball; Track • Anatomy of medical school life • Class notebook • Faculty members speak at spring regional meetings • Weddings • Births • In memoriam • Physicians Club meets •https://digitalcommons.ursinus.edu/alumnijournal/1089/thumbnail.jp

Molecules with ALMA at Planet-forming Scales (MAPS). XI. CN and HCN as tracers of photochemistry in disks

Funding: I.C. was supported by NASA through the NASA Hubble Fellowship grant HST-HF2-51405.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. A.S.B. acknowledges the studentship funded by the Science and Technology Facilities Council of the United Kingdom (STFC). J.D.I. acknowledges support from the Science and Technology Facilities Council of the United Kingdom (STFC) under ST/T000287/1. C.W. acknowledges financial support from the University of Leeds, STFC, and UKRI (grant Nos. ST/R000549/1, ST/T000287/1, MR/T040726/1).UV photochemistry in the surface layers of protoplanetary disks dramatically alters their composition relative to previous stages of star formation. The abundance ratio CN/HCN has long been proposed to trace the UV field in various astrophysical objects; however, to date the relationship between CN, HCN, and the UV field in disks remains ambiguous. As part of the ALMA Large Program MAPS (Molecules with ALMA at Planet-forming Scales), we present observations of CN N = 1-0 transitions at 0.″3 resolution toward five disk systems. All disks show bright CN emission within ~50-150 au, along with a diffuse emission shelf extending up to 600 au. In all sources we find that the CN/HCN column density ratio increases with disk radius from about unity to 100, likely tracing increased UV penetration that enhances selective HCN photodissociation in the outer disk. Additionally, multiple millimeter dust gaps and rings coincide with peaks and troughs, respectively, in the CN/HCN ratio, implying that some millimeter substructures are accompanied by changes to the UV penetration in more elevated disk layers. That the CN/HCN ratio is generally high (>1) points to a robust photochemistry shaping disk chemical compositions and also means that CN is the dominant carrier of the prebiotically interesting nitrile group at most disk radii. We also find that the local column densities of CN and HCN are positively correlated despite emitting from vertically stratified disk regions, indicating that different disk layers are chemically linked. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement.Publisher PDFPeer reviewe

Molecules with ALMA at Planet-forming Scales (MAPS). VI. Distribution of the small organics HCN, C2H, and H2CO

Funding: I.C. was supported by NASA through the NASA Hubble Fellowship grant HST-HF2-51405.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. C.W. acknowledges financial support from the University of Leeds, STFC, and UKRI (grant Nos. ST/R000549/1, ST/T000287/1, and MR/T040726/1). J.D.I. acknowledges support from the Science and Technology Facilities Council of the United Kingdom (STFC) under ST/T000287/1.Small organic molecules, such as C2H, HCN, and H2CO, are tracers of the C, N, and O budget in protoplanetary disks. We present high-angular-resolution (10-50 au) observations of C2H, HCN, and H2CO lines in five protoplanetary disks from the Molecules with ALMA at Planet-forming Scales (MAPS) ALMA Large Program. We derive column density and excitation temperature profiles for HCN and C2H, and find that the HCN emission arises in a temperate (20-30 K) layer in the disk, while C2H is present in relatively warmer (20-60 K) layers. In the case of HD 163296, we find a decrease in column density for HCN and C2H inside one of the dust gaps near ~83 au, where a planet has been proposed to be located. We derive H2CO column density profiles assuming temperatures between 20 and 50 K, and find slightly higher column densities in the colder disks around T Tauri stars than around Herbig Ae stars. The H2CO column densities rise near the location of the CO snowline and/or millimeter dust edge, suggesting an efficient release of H2CO ices in the outer disk. Finally, we find that the inner 50 au of these disks are rich in organic species, with abundances relative to water that are similar to cometary values. Comets could therefore deliver water and key organics to future planets in these disks, similar to what might have happened here on Earth. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement.Publisher PDFPeer reviewe

Molecules with ALMA at Planet-forming Scales (MAPS). VIII. CO gap in AS 209-gas depletion or chemical processing?

Funding: I.C. was supported by NASA through the NASA Hubble Fellowship grant HST-HF2-51405.001-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract NAS5-26555. J.D.I. acknowledges support from the Science and Technology Facilities Council of the United Kingdom (STFC) under ST/T000287/1. C.W. acknowledges financial support from the University of Leeds, SFTC, and UKRI (grant Nos. ST/R000549/1, ST/T000287/1, and MR/T040726/1).Emission substructures in gas and dust are common in protoplanetary disks. Such substructures can be linked to planet formation or planets themselves. We explore the observed gas substructures in AS 209 using thermochemical modeling with RAC2D and high-spatial-resolution data from the Molecules with ALMA at Planet-forming Scales (MAPS) program. The observations of C18O J = 2-1 emission exhibit a strong depression at 88 au overlapping with the positions of multiple gaps in millimeter dust continuum emission. We find that the observed CO column density is consistent with either gas surface-density perturbations or chemical processing, while C2H column density traces changes in the C/O ratio rather than the H2 gas surface density. However, the presence of a massive planet (>0.2 MJup) would be required to account for this level of gas depression, which conflicts with constraints set by the dust emission and the pressure profile measured by gas kinematics. Based on our models, we infer that a local decrease of CO abundance is required to explain the observed structure in CO, dominating over a possible gap-carving planet present and its effect on the H2 surface density. This paper is part of the MAPS special issue of the Astrophysical Journal Supplement.Publisher PDFPeer reviewe

The first tropical ‘metal farm’: some perspectives from field and pot experiments

Agromining is the chain of processes of phytoextraction of economically valuable elements by selected hyperaccumulator plants, and subsequent processing of biomass to produce targeted metals or commercial compounds of high value. Although substantial unrealized opportunities exist for developing economic nickel (Ni) agromining in the tropics, this technology has remained relatively unexplored. This study investigated the soil chemistry of a newly established tropical ‘metal farm’ and elucidated the performance of a prospective ‘metal crop’ species (Phyllanthus rufuschaneyi) to be used in a large-scale tropical Ni agromining program on ultramafic soils in Sabah (Malaysia). We found that a major portion of the site (>90%) had high total Ni concentrations (>2000 μg g) in the soil (shallow Eutric Cambisol Magnesic). This study also recorded high phytoavailable soil Ni concentrations in the field site, which is a desired property of soils intended for Ni agromining. Moreover, the average soil pH of the field (pH 6.4) is ideal for maximum Ni uptake in the local candidate species. We recorded low concentrations of Ca, K and P, suggesting the need for a fertilizer regime in the farm. The extraordinary shoot Ni concentrations (>2 wt%), coupled with the high purity of the ‘bio-ore’ derived from Phyllanthus rufuschaneyi, confirm its high potential for economic Ni agromining. The success of our first field trial is critical to provide ‘real-life’ evidence of the value of large-scale tropical ‘metal farming’. Research priorities include the need to intensify the search for candidate species, determine their agronomy, develop mass propagation methods, and to test technologies to process the biomass to recover valuable products