Academic Senate - Meeting Minutes, 4/18/2017

<p>All values are presented with SD. Differences between <i>LDLR−/−</i> and the other two genotypes are significant where indicated, ANOVA: *p<0.05, **p<0.01.</p

Table1_Analyzing the Spatial Distribution of LST and Its Relationship With Underlying Surfaces in Different Months by Classification and Intersection.pdf

Urban heat islands (UHIs) have become one of the most critical issues around the world, especially in the context of rapid urbanization and global climate change. Extensive research has been conducted across disciplines on the factors related to land surface temperature (LST) and how to mitigate the UHI effect. However, there remain deficiencies in the exploration of LST changes across time and their relationship with underlying surfaces in different temperature ranges. In order to fill the gap, this study compared the LST of each month by using the quantile classification method taking the Landsat 8 images of Nanjing on May 18th, July 21st, and October 9th in 2017 as the subject and then calculated the differences between July and May as well as that between July and October by an intersection tool taking the LST classes of July as the baseline. Additionally, the spatial pattern of each temperature class and intersection area was analyzed with the help of several landscape metrics, and the land contribution index (LCI) was utilized to better quantify the thermal contribution of each underlying surface to the area. The results indicated that the difference between months mainly reflected in the medium temperature area, especially between July and October, in which landscape patterns illustrated a trend of fragmentation and decentralization. The proportions of underlying surfaces in different types of intersection revealed the distinction of their warming and cooling degrees over time, in which the warming degree of other rigid pavement was higher in the warming process from May to July, and the cooling degree of buildings was greater in the cooling process from July to October. The LCI of each underlying surface in the entire study area was different from that in each temperature class, indicating that underlying surfaces had distinguished thermal contributions in different temperature ranges. This study is expected to fill the gap in previous studies and provide a new perspective on the mitigation of UHI.</p

ENC1-mediated down-regulation of Nrf2 was independent of proteasomal or lysosomal degradation.

<p>A. MDA-MB-231 cells were transfected with an empty vector or a vector for ENC1-Myc. Transfected cells were treated with proteasome inhibitors MG132 (M) (10 µM), clasto-lactacystin β-lactone (Lac) (10 µM) or epoxomicin (Ep) (1 µM), or lysosome inhibitors chloroquine (Ch) (50 µM) or ammonium chloride (Ac) (50 mM) for 4 hr before cells were lysed at 48 hr post-transfection. Cell lysates were subjected to immunoblot analysis with anti-HA, anti-Myc and anti-β-actin antibodies. B. MDA-MB-231 cells were transfected with HA-Nrf2 and with an empty vector or ENC1-Myc. Transfected cells were treated with proteasome and lysosome inhibitors as described above. Immunoblot analysis was performed. C. <i>In vivo</i> ubiquitination assay was performed in MDA-MB-231 cells transfected with plasmids for HA-Ub and Gal4-Neh2, along with either ENC1-Myc or Keap1-CBD. Transfected cells were treated with 10 µM MG132 for 4 hr prior to cell lysis. Cell lysates were denatured by heating and subjected to immunoprecipitation with anti-Gal4 antibodies. The precipitated protein complexes were subjected to immunoblot analysis with anti-HA antibodies for detecting ubiquitin-conjugated Gal4-Neh2 (top panel). Small aliquots of total cell lysates were immunoblotted with the indicated antibodies (bottom three panels).</p

ENC1 down-regulated Nrf2 at the translational level.

<p>A. Pulse-chase assay was conducted with MDA-MB-231 cells transfected with either an empty vector or an expression vector for ENC1-Myc. Cells were incubated for 30 minutes with medium containing [³⁵S]-methionine and [³⁵S]-cysteine to label proteins. Cells were then washed and incubated in normal complete medium for the indicated time periods prior to cell lysis. Cell lysates were subjected to immunoprecipitation with anti-Nrf2 antibodies and immunoprecipitates were resolved in SDS-PAGE gel and detected by autoradiography. B. Nrf2 band intensities were quantified using Quantity One (BIO-RAD) and the half-life was plotted and calculated. C. Pulse-chase assay was conducted in the same way, except that cells were treated with 100 µM tBHQ for 4 hr. D. Quantified data of Fig. 5C.</p

Keap1 was not essential in ENC1-mediated down-regulation of Nrf2.

<p>A. MDA-MB-231 cells were transfected with an expression vector for ENC1-Myc, along with an empty vector or an expression vector for Keap1-CBD. Cell lysates were subjected to chitin pull-down assay. Precipitated proteins were subjected to immunoblot analysis with anti-Myc and anti-CBD antibodies for detection of Keap1-CBD and ENC1-Myc (top panel). Small aliquots of total lysates were analyzed by immunoblot with the indicated antibodies (bottom panel). B. Cell lysates from MDA-MB-231 cells were immunoprecipitated with anti-Keap1 antibody. The precipitated protein complexes were subjected to immunoblot analysis with anti-Nrf2 and anti-ENC1 antibodies. IgG was included in the immunoprecipitation analysis as a negative control. C. Plasmids for full-length ENC1 (E-FL) and two ENC1 deletion mutants E320 and E570, Nrf2 and Luciferase (Luc) were used for <i>in vitro</i> transcription/translation to synthesize [³⁵S]-labeled proteins. The proteins were incubated with Keap1-His purified from <i>E. Coli</i>. Protein complexes containing Keap1 were pulled-down with nickel beads and resolved in SDS-PAGE and detected by autoradiography. Nrf2 and Luciferase were used as a positive and a negative control. 20% of [³⁵S]-labeled proteins were resolved by SDS-PAGE gel to show equivalent input of each protein (right panel). D. Keap1-/- and wild-type MEF cells were transfected with plasmids for HA-Nrf2 and ENC1-Myc. Cells were lysed at 48 hr post-transfection. Cell lysates were analyzed by immunoblot with anti-HA, anti-Myc and anti-β-actin. E. Cell lysates from MDA-MB-231 cells transfected with plasmids for Keap1-CBD, HA-Nrf2, and ENC1-Myc were used for pull-down assay with chitin beads Precipitated proteins were subjected to immunoblot analysis with anti-HA and anti-CBD antibodies (left figure, top two panels). Small aliquots of total lysates were analyzed by immunoblot with the indicated antibodies (left figure, bottom four panels). Nrf2 and β-Actin band intensities were quantified using Quantity One (BIO-RAD). The intensity of Nrf2 was normalized to that of β-actin (right graph).</p

Modulating Affinities of Di-2-picolylamine (DPA)-Substituted Quinoline Sensors for Zinc Ions by Varying Pendant Ligands

We have developed a series of di-2-picolylamine (DPA)-substituted quinoline sensors, HQ1–4, bearing a pendant ligand at the 8 position of quinoline. UV–vis spectra of HQ1–4 showed similar variations to that of HQ5 but with different varying extents upon the titration of zinc ions. Fluorescence intensities of HQ1, HQ3, and HQ4 were enhanced 4–6 times upon the addition of 1 equiv of zinc ions under an aqueous buffer. Somewhat unexpectedly, HQ2 is nonfluorescent in the presence of metal ions, including zinc ions. The affinities of HQ sensors are distributed in a broad range from nanomolarity to femtomolarity by varying the pendant ligands near the coordination unit. More importantly, these new sensors exhibited very high selectivity for Zn2+ over Na+, K+, Mg2+, and Ca2+ at the millimolar level and over other transition metal ions at the micromolar level, except for Cd2+. These findings indicated that the incorporations of the pendant groups exerted no effect on the spectroscopic properties and selectivity of the parent fluorescent sensor, with the exception of HQ2. Finally, X-ray crystal structures of ZnHQʼs revealed that the auxiliary pendant groups at the 8 position participated in zinc coordination and were able to tune the affinities of HQ sensors

Light-Controllable Cucurbit[7]uril-Based Molecular Shuttle

The design and construction of novel artificial molecular machines can be categorized as a currently important field of modern chemistry. In the present work, a novel photoresponsive [3]­rotaxane containing two cucurbit[7]­uril (CB[7]) rings and a dumbbell component consisting of one <i>trans</i>-azobenzene unit along with two viologen units was developed. Each viologen group was encircled by a CB[7] ring with a rapid shuttling equilibration distribution extended to the <i>trans</i>-azobenzene unit located in the middle of the dumbbell component. Upon the <i>trans</i>-to-<i>cis</i> photoisomerization of the azobenzene unit under UV light irradiation, a shuttling restriction of the CB[7] rings along the dumbbell component was observed. The equilibration distribution of the macrocycles on the dumbbell component can be recovered by the <i>cis</i>-to-<i>trans</i> photoisomerization of the azobenzene unit under visible light irradiation. Such a controllable shuttling process was fully characterized by ¹H NMR spectroscopy and was easily indicated by fluorescent changes of the [3]­rotaxane

Modulating Affinities of Di-2-picolylamine (DPA)-Substituted Quinoline Sensors for Zinc Ions by Varying Pendant Ligands

We have developed a series of di-2-picolylamine (DPA)-substituted quinoline sensors, HQ1–4, bearing a pendant ligand at the 8 position of quinoline. UV–vis spectra of HQ1–4 showed similar variations to that of HQ5 but with different varying extents upon the titration of zinc ions. Fluorescence intensities of HQ1, HQ3, and HQ4 were enhanced 4–6 times upon the addition of 1 equiv of zinc ions under an aqueous buffer. Somewhat unexpectedly, HQ2 is nonfluorescent in the presence of metal ions, including zinc ions. The affinities of HQ sensors are distributed in a broad range from nanomolarity to femtomolarity by varying the pendant ligands near the coordination unit. More importantly, these new sensors exhibited very high selectivity for Zn2+ over Na+, K+, Mg2+, and Ca2+ at the millimolar level and over other transition metal ions at the micromolar level, except for Cd2+. These findings indicated that the incorporations of the pendant groups exerted no effect on the spectroscopic properties and selectivity of the parent fluorescent sensor, with the exception of HQ2. Finally, X-ray crystal structures of ZnHQʼs revealed that the auxiliary pendant groups at the 8 position participated in zinc coordination and were able to tune the affinities of HQ sensors

Data collection and Statistics from crystallographic analyses.

<p>Values in parentheses are for the highest resolution shell.</p>a<p><i>R</i>_sym  = ∑|<i>I</i>_obs_<i>I</i>_avg|/∑<i>I</i>_obs.</p>b<p><i>R</i>_{work, free}  = ∑||<i>F</i>_obs|_|<i>F</i>_calc|| / ∑|<i>F</i>_obs|.</p>c<p><i>R</i>_free values are calculated for a randomly selected 5% of the data that was excluded from the refinement.</p>d<p>Root mean square deviation from ideal/target geometries.</p

Tris(2,4-difluorophenyl)borane/Triisobutylphosphine Lewis Pair: A Thermostable and Air/Moisture-Tolerant Organic Catalyst for the Living Polymerization of Acrylates

Lewis pair polymerization (LPP) has emerged as a powerful tool for the efficient polymerization of polar vinyl monomers. However, air/moisture, highly sensitive metal-based catalysts, and low reaction temperatures are necessary for achieving highly active LPP with a high degree of control. In this contribution, we report the development of a robust Lewis pair (LP) organic catalyst based on tris­(2,4-difluorophenyl)­borane and triisobutylphosphine, which not only renders efficient and living LPP of acrylates for the first time at ambient or even industrially relevant temperature (60–80 °C) but also allows the polymerization under an open-air condition. Accordingly, well-defined multiblock acrylic copolymers have been synthesized successfully over a broad reaction temperature range. Good thermal stability, appreciable air/moisture tolerance, high efficiency, and precise controllability of this LP organic catalyst thus establish LPP as a truly green/sustainable and practical polymerization methodology