763 research outputs found
Alien Registration- Morrill, Huch M.,Sr. (Greenville, Piscataquis County)
https://digitalmaine.com/alien_docs/11410/thumbnail.jp
Isolation and culture of adult intestinal, gastric, and lver organoids for cre-recombinase-mediated gene deletion
The discovery of Lgr5 as a marker of adult stem cells meant that stem cell populations could be purified and studied in isolation. Importantly, when cultured under the appropriate conditions these stem cells form organoids in tissue culture that retain many features of the tissue of origin. The organoid cultures are accessible to genetic and biochemical manipulation, bridging the gap between in vivo mouse models and conventional tissue culture. Here we describe robust protocols to establish organoids from gastrointestinal tissues (stomach, intestine, liver) and Cre-recombinase mediated gene manipulation in vitro
Cyclische Diazastannylene. - XXIV : Zur Umsetzung von (tert-Butylimino)stannylen mit Chlorwasserstoff
(tert-Butylimino)stannylen (1) reagiert mit Chlorwasserstoff zu [tBuN(H)-SnCl]2 (2a), tBuNH2 · SnCl2 (3) und tBuNH3 SnCl3 (4). Da die Trennung der kristallinen Produkte Schwierigkeiten macht, ist man auf Alternativsynthesen von 2a, 3 und 4 angewiesen. Me2Si[N(tBu)H][N(tBu)]SnX (6a: X = Cl, 6b: X = Br, 6c: X = I) stellt eine Ausgangsstufe dar, die mit tert-Butylamin zu 2a (X = Cl) und 2b (X = Br) quantitativ umgesetzt werden kann. 3 und 4 entstehen aus 2a u.a. durch HCl-Addition. 6a, b und c zeigen unterschiedliche 1H-NMR-Spektren in Abhängigkeit von der Temperatur, was auf eine intramolekulare Ligandenumordnung hinweist. Die Röntgenstrukturanalysen von 6a (orthorhombisch, Raumgruppe P112121), 3 (monoklin, P21/c, und triklin, P) und 4 (triklin, P) weisen 6a als Molekül mit einer intramolekularen Donor-Akzeptor-Bindung [Sn-N = 2.347(6) Å], 3 in beiden Modifikationen als Addukt von SnCl2 an tBuNH2 [Sn-N = 2.334(4) Å (monoklin) bzw. 2.338(4) Å (triklin)] und 4 als Ionenpaar tBuNH3 SnCl3- mit H-Cl-Brücken im Kristall aus [Sn-Cl = 2.542 (Mittelwert), C-N = 1.515(6) Å]
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Gallium and Indium Alkoxides with Hydride, Cyclopentadienediide and Copper(I) tert-Butoxide as further Components
Gallium hydride stabilized by the base quinonuclidine reacts with acetone under addition of the Ga-H function to the carbon–oxygen double bond yielding (HGa)5(OiPr)8O (1) as isolable compound. (HGa)5(OiPr)8O may be formally split in to four entities of HGa(OiPr)2 and one entity HGaO. The inner atomic skeleton of 1 is a novel Ga5O9 heterocluster with gallium atoms occupying the corners of a distorted trigonal bi-pyramid, an oxygen atom in the center and the remaining alcoholate oxygen atoms bridging eight of the nine edges of the bi-pyramid (X-ray diffraction analysis). Potassium indium alkoxide KIn(OtBu)4 has been used to synthesize several new compounds like In4(OtBu)8(C5H4)2 (2), (py)2CuIn(OtBu)4 (3), and [CuIn(OtBu)4]2 (4) by reaction with TiCl2cp2 (2) and CuCl (3, 4). All compounds were characterized by spectroscopic means and by X-ray structure analyses revealing novel polycyclic structures. © 2019 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA
Novel C-35 terpenoids from the Panamarian liverwort Plagiochila Moritziana
A new class of C-35 terpenoids is described from Hepaticae: plagiospirolide A and plagiospirolide B, two novel heptacyclic spiro-terpenes were isolated from the Panamanian liverwort Plagiochila moritziana Lindbg. & Gott. Structures were determined by MS, extensive NMR studies and X-ray crystallographic analysis. The compounds may be biosynthesized by condensation of a sesquiterpenoid and a diterpenoid unit in a Diels-Alder like reaction
Maternal serum interleukin-1β, -6 and -8 levels and potential determinants in pregnancy and peripartum
Aims: To measure maternal serum interleukins (IL) in pregnancy, delivery and early puerperium, and to identify their potential determinants. Methods: Prospective longitudinal measures of serum IL-1β, IL-6 and IL-8 in 38 healthy pregnant women at antenatal visits, through labor and delivery, with clinical correlates (infection, vaginal hemorrhage and anemia) recorded by questionnaire. Results: Pregnancy IL levels remained consistently low. IL-1β increased shortly before delivery, then returned to pregnant levels, except where blood loss exceeded 500 ml. IL-6 and IL-8 rose at labor onset and exceeded pregnancy levels through postpartum day three. Postpartum IL-6 was higher after non-elective cesarean section than after spontaneous delivery (P < 0.0001), and where blood loss exceeded 500 ml. IL-6 and IL-8 were higher with systemic infection during delivery (P < 0.0001) and on postpartum day one (P < 0.05); IL-8 was higher in anemia (delivery: P < 0.005; postpartum day 1: P < 0.05). Differences due to delivery mode and systemic infection remained significant after correction for other conditions. Conclusions: Labor-dependent inflammation increases all IL levels at delivery. Further studies with larger sample sizes are required to establish reference values differentiating physiology from pathology as an aid to peripartum managemen
Culture and establishment of self-renewing human and mouse adult liver and pancreas 3D organoids and their genetic manipulation.
Adult somatic tissues have proven difficult to expand in vitro, largely because of the complexity of recreating appropriate environmental signals in culture. We have overcome this problem recently and developed culture conditions for adult stem cells that allow the long-term expansion of adult primary tissues from small intestine, stomach, liver and pancreas into self-assembling 3D structures that we have termed 'organoids'. We provide a detailed protocol that describes how to grow adult mouse and human liver and pancreas organoids, from cell isolation and long-term expansion to genetic manipulation in vitro. Liver and pancreas cells grow in a gel-based extracellular matrix (ECM) and a defined medium. The cells can self-organize into organoids that self-renew in vitro while retaining their tissue-of-origin commitment, genetic stability and potential to differentiate into functional cells in vitro (hepatocytes) and in vivo (hepatocytes and endocrine cells). Genetic modification of these organoids opens up avenues for the manipulation of adult stem cells in vitro, which could facilitate the study of human biology and allow gene correction for regenerative medicine purposes. The complete protocol takes 1-4 weeks to generate self-renewing 3D organoids and to perform genetic manipulation experiments. Personnel with basic scientific training can conduct this protocol.LB is supported by an EMBO Postdoctoral fellowship (EMBO ALTF 794-2014). CH is supported by a Cambridge Stem Cell Institute Seed Fund award and the Herchel Smith Fund. BK is supported by a Sir Henry Dale Fellowship from the Wellcome Trust and the Royal Society. MH is a Wellcome Trust Sir Henry Dale Fellow and is jointly funded by the Wellcome Trust and the Royal Society (104151/Z/14/Z).This is the author accepted manuscript. The final version is available from Nature Publishing Group via http://dx.doi.org/10.1038/nprot.2016.097
Reactivity of Phenylacetylene toward Unsymmetrical Disilenes: Regiodivergent [2+2] Cycloaddition vs. CH Addition
We report the regiodivergent reaction of phenylacetylene with a selection of disilenes Tip2Si=SiTipR as well as bridged tetrasiladienes Tip2Si=SiTip−LU−SiTip=SiTip2 (Tip=2,4,6-iPr3C6H2, R=aryl groups; LU=arylene linkers). The regioselectivity of the [2+2] cycloaddition as determined by NMR spectroscopy and X-ray crystallography is shown to strongly depend on the nature of the substituent R. The small size of the substituents compared to the Tip groups in both cases suggests a change in mechanism between the substrates with only hydrogen in the ortho-positions of R and LU and those with either ortho-methyl groups or condensed aromatic rings. In contrast, the presence of catalytic quantities of base completely suppresses cycloaddtion in favor of the formal CH addition of phenylacetylene. Quenching reactions with either MeI or MeOH after the stoichiometric application of deprotonated phenylacetylene as well as NMR studies at low temperature prove the intermediacy of an alkynyl-substituted disilanyl lithium and thus suggest a carbolithiation pathway for the net CH addition
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