Graft immaturity and safety concerns in transplanted human kidney organoids

Sun Ah Nam,Eunjeong Seo,Jin Won Kim,Hyung-Wook Kim,Hong Lim Kim,Kyuryung Kim,Tae-Min Kim,주지현,Ivan G. Gomez,Kohei Uchimura,Benjamin D. Humphreys,양철우,Jae Yeon Lee,김진,Dong Woo Cho,Benjamin S. Freedman,Yo 생화학분자생물학회 2019 Experimental and molecular medicine Vol.51 No.-

For chronic kidney disease, regeneration of lost nephrons with human kidney organoids derived from induced pluripotent stem (iPS) cells is proposed to be an attractive potential therapeutic option. It remains unclear, however, whether organoids transplanted into kidneys in vivo would be safe or functional. Here, we purified kidney organoids and transplanted them beneath the kidney capsules of immunodeficient mice to test their safety and maturity. Kidney organoid grafts survived for months after transplantation and became vascularized from host mouse endothelial cells. Nephron-like structures in grafts appeared more mature than kidney organoids in vitro, but remained immature compared with the neighboring mouse kidney tissue. Ultrastructural analysis revealed filtration barrier-like structures, capillary lumens, and tubules with brush border in the transplanted kidney organoids, which were more mature than those of the kidney organoids in vitro but not as organized as adult mammalian kidneys. Immaturity was a common feature of three separate differentiation protocols by immunofluorescence analysis and single cell RNA sequencing. Stroma of transplanted kidney organoid grafts were filled with vimentin-positive mesenchymal cells, and chondrogenesis, cystogenesis, and stromal expansion were observed in the long term. Transcription profiles showed that long-term maintenance after kidney organoid transplantation induced transcriptomic reprogramming with prominent suppression of cell-cycle-related genes and upregulation of extracellular matrix organization. Our data suggest that kidney organoids derived from iPS cells may be transplantable but strategies to improve nephron differentiation and purity are required before they can be applied in humans as a therapeutic option.

Capture and metathesis-based release of potassium salts by a multitopic ion receptor

Kim, Sung Kuk,Hay, Benjamin P.,Kim, Jong Seung,Moyer, Bruce A.,Sessler, Jonathan L. The Royal Society of Chemistry 2013 Chemical communications Vol.49 No.21

<P>The multitopic ion-pair receptor <B>2</B> is able to recognize and extract various cesium and potassium salts <I>via</I> three different ion recognition modes. Furthermore, it is capable of extracting and then releasing KNO<SUB>3</SUB><I>via</I> ion-pair metathesis with CsClO<SUB>4</SUB>, allowing KNO<SUB>3</SUB> recovery.</P> <P>Graphic Abstract</P><P>The multitopic ion-pair receptor <B>2</B> is capable of extracting and then releasing KNO<SUB>3</SUB><I>via</I> ion-pair metathesis with CsClO<SUB>4</SUB>. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c3cc39117e'> </P>

Quantum Confinement Induced Excitonic Mechanism in Zinc-Oxide-Nanowalled Microrod Arrays for UV-Vis Surface-Enhanced Raman Scattering

Kim, Jayeong,Glier, Tomke E.,Grimm-Lebsanft, Benjamin,Buchenau, Sö,ren,Teubner, Melissa,Biebl, Florian,Kim, Nam-Jung,Kim, Heehun,Yi, Gyu-Chul,Rü,bhausen, Michael,Yoon, Seokhyun American Chemical Society 2019 The Journal of Physical Chemistry Part C Vol.123 No.40

<P>We studied surface-enhanced Raman spectroscopy (SERS) in 4-mercaptopyridine (4-Mpy) deposited on zinc oxide (ZnO) nanostructures, by using resonance Raman scattering covering a range of incident photon energies from 1.7 to 5.7 eV. We investigated all primary routes of the energy-specific resonances that are associated with the electronic transitions between the ZnO valence band (VB) to the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) to the ZnO conduction band (CB), respectively. Two resonances at 5.55 and 5.15 eV in the ultraviolet (UV) spectral range can be associated with transitions into the CB and most importantly into an excitonic-related state below the ZnO CB, respectively. The energy difference between the UV resonances is 0.4 eV corresponding to the excitonic binding energy as a result of excitonic quantum confinement in the 10-20 nm thick ZnO nanowalls. The observed excitonic SERS resonance enhancement of the ring-breathing mode of 4-Mpy is about 15 times stronger than for the VB resonance observed at 2.43 eV and free of luminescence background. Hence, we outline new pathways of improving the detectability of molecules by chemical SERS due to tuning of the quantum confinement in the excitonic resonance enhancement.</P> [FIG OMISSION]</BR>

Controlling Cesium CationRecognition via Cation Metathesiswithin an Ion Pair Receptor

Kim, Sung Kuk,Vargas-Zú,ñ,iga, GabrielaI.,Hay, Benjamin P.,Young, Neil J.,Delmau, Lætitia H.,Masselin, Charles,Lee, Chang-Hee,Kim, Jong Seung,Lynch, VincentM.,Moyer, Bruce A.,Sessler, Jona American Chemical Society 2012 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.134 No.3

<P>Ion pair receptor 3 bearing an anion binding site and multiple cation binding sites has been synthesized and shown to function in a novel binding-release cycle that does not necessarily require displacement to effect release. The receptor forms stable complexes with the test cesium salts, CsCl and CsNO3, in solution (10% methanol-d(4) in chloroform-d) as inferred from H-1 NMR spectroscopic analyses. The addition of KClO4 to these cesium salt complexes leads to a novel type of cation metathesis in which the 'exchanged' cations occupy different binding sites. Specifically, K+ becomes bound at the expense of the Cs+ cation initially present in the complex. Under liquid liquid conditions, receptor 3 is able to extract CsNO3 and CsCl from an aqueous D2O layer into nitrobenzene-d(5) as inferred from H-1 NMR spectroscopic analyses and radiotracer measurements. The Cs+ cation of the CsNO3 extracted into the nitrobenzene phase by receptor 3 may be released into the aqueous phase by contacting the loaded nitrobenzene phase with an aqueous KClO4 solution. Additional exposure of the nitrobenzene layer to chloroform and water gives 3 in its uncomplexed, ion-free form. This allows receptor 3 to be recovered for subsequent use. Support for the underlying complexation chemistry came from single-crystal X-ray diffraction analyses and gas-phase energy-minimization studies.</P>

Rational Expectations , Risk Premia and the Efficiency of the Foreign Exchange Markets

Kim, Benjamin J C 한국경제학회 1985 The Korean Economic Review Vol.1 No.1

Mechanism of seasonal Arctic sea ice evolution and Arctic amplification

Kim, Kwang-Yul,Hamlington, Benjamin D.,Na, Hanna,Kim, Jinju Copernicus GmbH 2016 The cryosphere Vol.10 No.5

<P><p><strong>Abstract.</strong> Sea ice loss is proposed as a primary reason for the Arctic amplification, although the physical mechanism of the Arctic amplification and its connection with sea ice melting is still in debate. In the present study, monthly ERA-Interim reanalysis data are analyzed via cyclostationary empirical orthogonal function analysis to understand the seasonal mechanism of sea ice loss in the Arctic Ocean and the Arctic amplification. While sea ice loss is widespread over much of the perimeter of the Arctic Ocean in summer, sea ice remains thin in winter only in the Barents-Kara seas. Excessive turbulent heat flux through the sea surface exposed to air due to sea ice reduction warms the atmospheric column. Warmer air increases the downward longwave radiation and subsequently surface air temperature, which facilitates sea surface remains to be free of ice. This positive feedback mechanism is not clearly observed in the Laptev, East Siberian, Chukchi, and Beaufort seas, since sea ice refreezes in late fall (November) before excessive turbulent heat flux is available for warming the atmospheric column in winter. A detailed seasonal heat budget is presented in order to understand specific differences between the Barents-Kara seas and Laptev, East Siberian, Chukchi, and Beaufort seas.</p> </P>

마이크로서페이싱의 성공과 실패 사례

Kim, Hyun Hwan,Benjamin Broughton,Lee, Moon Sup,Lee, Soon Jae 한국도로학회 2015 한국도로학회논문집 Vol.17 No.2

PURPOSES: This study set out to investigate the current state of microsurfacing in Texas and compared the results with the current state of the practice nationwide. METHODS: For this study, case studies were extracted from the existing literature and compared with the data obtained both from site visits by the research team and data obtained from a survey by Texas Department of Transportation (TxDOT) personnel. The successes and failures of microsurfacing are detailed and explanations of different issues are outlined. Forensic studies from Texas are included in the descriptions of those microsurfacings that failed when configured as part of the cape seals. RESULTS : Microsurfacing has been shown to be an effective pavement preservation technique when applied to an appropriate road, at an appropriate timing, and as a remedy for certain issues. The failures experienced in Texas can mostly be attributed to cape seals and an inability to recognize structurally faulty pavement. CONCLUSIONS : When applied to an appropriate road, at an appropriate timing, and as a remedy for certain issues, microsurfacing has been shown to perform well in numerous case studies. The majority of microsurfacing failures are the result of poor project selection, usually involving the treatment being applied to structurally unsound pavement.

Ethylenediamine Promotes Cu Nanowire Growth by Inhibiting Oxidation of Cu(111)

Kim, Myung Jun,Flowers, Patrick F.,Stewart, Ian E.,Ye, Shengrong,Baek, Seungyeon,Kim, Jae Jeong,Wiley, Benjamin J. American Chemical Society 2017 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.139 No.1

<P>The synthesis of metal nanostructures usually requires a capping agent that is generally thought to cause anisotropic growth by blocking the addition of atoms to specific crystal facets. This work uses a series of electrochemical measurements with a quartz crystal microbalance and single-crystal electrodes to elucidate the facet-selective chemistry occurring in the synthesis of Cu nanowires. Contrary to prevailing hypotheses, ethylenediamine, a so-called capping agent in the synthesis of Cu nanowires, causes anisotropic growth by increasing the rate of atomic addition to (111) facets at the end of a growing nanowire relative to (100) facets on the sides of a nanowire. Ethylenediamine increases the reduction rate of Cu(OH)(2)(-) on a Cu(111) surface relative to Cu(100) by selectively inhibiting the formation of Cu oxide on Cu(111). This work demonstrates how studying facet-selective electrochemistry can improve the understanding of the processes by which atoms assemble to form anisotropic metal nanostructures.</P>

A Calix[4]arene Strapped Calix[4]pyrrole: An Ion-Pair Receptor Displaying Three Different Cesium Cation Recognition Modes

Kim, Sung Kuk,Sessler, Jonathan L.,Gross, Dustin E.,Lee, Chang-Hee,Kim, Jong Seung,Lynch, Vincent M.,Delmau, Lætitia H.,Hay, Benjamin P. American Chemical Society 2010 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.132 No.16

<P>An ion-pair receptor, the calix[4]pyrrole-calix[4]arene pseudodimer <B>2</B>, bearing a strong anion-recognition site but not a weak cation-recognition site, has been synthesized and characterized by standard spectroscopic means and <I>via</I> single-crystal X-ray diffraction analysis. In 10% CD<SUB>3</SUB>OD in CDCl<SUB>3</SUB> (v/v), this new receptor binds neither the Cs<SUP>+</SUP> cation nor the F<SUP>−</SUP> anion when exposed to these species in the presence of other counterions; however, it forms a stable 1:1 solvent-separated CsF complex when exposed to these two ions in concert with one another in this same solvent mixture. In contrast to what is seen in the case of a previously reported crown ether “strapped” calixarene−calixpyrrole ion-pair receptor <B>1</B> (J. Am. Chem. Soc. 2008, 130, 13162−<lpage>13166</lpage>), where Cs<SUP>+</SUP> cation recognition takes place within the crown, in <B>2</B>·CsF cation recognition takes place within the receptor cavity itself, as inferred from both single-crystal X-ray diffraction analyses and <SUP>1</SUP>H NMR spectroscopic studies. This binding mode is supported by calculations carried out using the MMFF94 force field model. In 10% CD<SUB>3</SUB>OD in CDCl<SUB>3</SUB> (v/v), receptor <B>2</B> shows selectivity for CsF over the Cs<SUP>+</SUP> salts of Cl<SUP>−</SUP>, Br<SUP>−</SUP>, and NO<SUB>3</SUB><SUP>−</SUP> but will bind these other cesium salts in the absence of fluoride, both in solution and in the solid state. In the case of CsCl, an unprecedented 2:2 complex is observed in the solid state that is characterized by two different ion-pair binding modes. One of these consists of a contact ion pair with the cesium cation and chloride anion both being bound within the central binding pocket and in direct contact with one another. The other mode involves a chloride anion bound to the pyrrole NH protons of a calixpyrrole subunit and a cesium cation sandwiched between two cone shaped calix[4]pyrroles originating from separate receptor units. In contrast to what is seen for CsF and CsCl, single-crystal X-ray structural analyses and <SUP>1</SUP>H NMR spectroscopic studies reveal that receptor <B>2</B> forms a 1:1 complex with CsNO<SUB>3</SUB>, with the ions bound in the form of a contact ion pair. Thus, depending on the counteranion, receptor <B>2</B> is able to stabilize three different ion-pair binding modes with Cs<SUP>+</SUP>, namely solvent-bridged, contact, and host-separated.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2010/jacsat.2010.132.issue-16/ja100715e/production/images/medium/ja-2010-00715e_0014.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja100715e'>ACS Electronic Supporting Info</A></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja100715e'>ACS Electronic Supporting Info</A></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja100715e'>ACS Electronic Supporting Info</A></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja100715e'>ACS Electronic Supporting Info</A></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja100715e'>ACS Electronic Supporting Info</A></P>

Pyrrole- and Naphthobipyrrole-Strapped Calix[4]pyrroles as Azide Anion Receptors

Kim, Seung Hyeon,Lee, Juhoon,Vargas-Zú,ñ,iga, Gabriela I.,Lynch, Vincent M.,Hay, Benjamin P.,Sessler, Jonathan L.,Kim, Sung Kuk American Chemical Society 2018 Journal of organic chemistry Vol.83 No.5

<P>The binding interactions between the azide anion (N<SUB>3</SUB><SUP>-</SUP>) and the strapped calix[4]pyrroles <B>2</B> and <B>3</B> bearing auxiliary hydrogen bonding donors on the bridging moieties, as well as of normal calix[4]pyrrole <B>1</B>, were investigated via <SUP>1</SUP>H NMR spectroscopic and isothermal titration calorimetry analyses. The resulting data revealed that receptors <B>2</B> and <B>3</B> have significantly higher affinities for the azide anion in organic media as compared with the unfunctionalized calix[4]pyrrole <B>1</B> and other azide receptors reported to date. Single crystal X-ray diffraction analyses and calculations using density functional theory revealed that receptor <B>2</B> binds CsN<SUB>3</SUB> in two distinct structural forms. As judged from the metric parameters, in the resulting complexes one limiting azide anion resonance contributor is favored over the other, with the specifics depending on the binding mode. In contrast to what is seen for <B>2</B>, receptor <B>3</B> forms a CsN<SUB>3</SUB> complex in 20% CD<SUB>3</SUB>OD in CDCl<SUB>3</SUB>, wherein the azide anion is bound only vertically to the NH protons of the calix[4]pyrrole and the cesium cation is complexed within the cone shaped-calix[4]pyrrole bowl. The bound cesium cation is also in close proximity to a naphthobipyrrole subunit present in a different molecule, forming an apparent cation-π complex.</P> [FIG OMISSION]</BR>