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1. Optimization of crystal packing in semiconducting spin-crossover materials with fractionally charged TCNQ ^δ− anions (0 < δ < 1)

   https://doi.org/10.1039/D1SC02843J  

   Üngör, Ökten; Choi, Eun Sang; Shatruk, Michael (August 2021, Chemical Science)

   Co-crystallization of the prominent Fe( ii ) spin-crossover (SCO) cation, [Fe(3-bpp) 2 ] 2+ (3-bpp = 2,6-bis(pyrazol-3-yl)pyridine), with a fractionally charged TCNQ δ − radical anion has afforded a hybrid complex [Fe(3-bpp) 2 ](TCNQ) 3 ·5MeCN (1·5MeCN, where δ = −0.67). The partially desolvated material shows semiconducting behavior, with the room temperature conductivity σ RT = 3.1 × 10 −3 S cm −1 , and weak modulation of conducting properties in the region of the spin transition. The complete desolvation, however, results in the loss of hysteretic behavior and a very gradual SCO that spans the temperature range of 200 K. A related complex with integer-charged TCNQ − anions, [Fe(3-bpp) 2 ](TCNQ) 2 ·3MeCN (2·3MeCN), readily loses the interstitial solvent to afford desolvated complex 2 that undergoes an abrupt and hysteretic spin transition centered at 106 K, with an 11 K thermal hysteresis. Complex 2 also exhibits a temperature-induced excited spin-state trapping (TIESST) effect, upon which a metastable high-spin state is trapped by flash-cooling from room temperature to 10 K. Heating above 85 K restores the ground-state low-spin configuration. An approach to improve the structural stability of such complexes is demonstrated by using a related ligand 2,6-bis(benzimidazol-2′-yl)pyridine (bzimpy) to obtain [Fe(bzimpy) 2 ](TCNQ) 6 ·2Me 2 CO (4) and [Fe(bzimpy) 2 ](TCNQ) 5 ·5MeCN (5), both of which exist as LS complexes up to 400 K and exhibit semiconducting behavior, with σ RT = 9.1 × 10 −2 S cm −1 and 1.8 × 10 −3 S cm −1 , respectively. 

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2. Administration of alendronate exacerbates ammonium chloride-induced acidosis in mice

   https://doi.org/10.1371/journal.pone.0291649  

   Moody, Mikayla; Schmidt, Tannin A.; Trivedi, Ruchir; Deymier, Alix (September 2023, PLOS ONE)

   Shah, Furqan A. (Ed.)

   Bone disease is highly prevalent in patients with chronic kidney disease (CKD), leading to an increased risk of bone fractures. This is due in part to metabolic acid-induced bone dissolution. Bisphosphonates (BPPs) are a potential treatment for inhibiting bone dissolution; however, there are limited studies observing the use of BPPs on acidotic patients. We aimed to determine efficacy of BPPs on maintaining bone health and pH regulation in acid-exposed mice. Using a diet-induced murine model of metabolic acidosis, we examined bone structure, composition, and mechanics as well as blood gases for three groups: control, acidosis, and acidosis + bisphosphonates (acidosis+BPP). Acidosis was induced for 14 days and alendronate was administered every 3 days for the acidosis+BPP group. The administration of BPP had little to no effect on bone structure, mechanics, and composition of the acidosis bones. However, administration of BPP did cause the mice to develop more severe acidosis than the acidosis only group. Overall, we discovered that BPPs may exacerbate acidosis symptoms by inhibiting the release of buffering ions from bone. Therefore, we propose that BPP administration should be carefully considered for those with CKD and that alkali supplementation could help minimize acidifying effects. 

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3. meso -Alkylidenyl dibenzihexaphyrins: synthesis and protonation studies

   https://doi.org/10.1039/c9cc04607k  

   Hong, Seong-Jin; Dutta, Ranjan; Kumar, Ravi; He, Qing; Lynch, Vincent M.; Sessler, Jonathan L.; Lee, Chang-Hee (August 2019, Chemical Communications)

   The synthesis and characterization of the alkylidenyl-dibenzihexaphyrins bearing four indanedionyl groups at the meso -positions linked via four meso -exocyclic double bonds is reported. Treatment with trifluoroacetic acid at 50 °C leads to C(α)-protonation of the two indanedionyl groups resulting increased macrocyclic conjugation with dramatic red shifted absorption spectra. 

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4. The Cosmic Ultraviolet Baryon Survey (CUBS) – VI. Connecting physical properties of the cool circumgalactic medium to galaxies at z ≈ 1

   https://doi.org/10.1093/mnras/stad1886  

   Qu, Zhijie; Chen, Hsiao-Wen; Rudie, Gwen_C; Johnson, Sean_D; Zahedy, Fakhri_S; DePalma, David; Boettcher, Erin; Cantalupo, Sebastiano; Chen, Mandy_C; Cooksey, Kathy_L; et al (June 2023, Monthly Notices of the Royal Astronomical Society)

   ABSTRACT This paper presents a newly established sample of 19 unique galaxies and galaxy groups at redshift z = 0.89–1.21 in six QSO fields from the Cosmic Ultraviolet Baryon Survey (CUBS), designated as the CUBSz1 sample. In this sample, nine galaxies or galaxy groups show absorption features, while the other 10 systems exhibit 2σ upper limits of $$\log N (\rm{He\,{\small I}})/\mbox{$${\rm cm^{-2}}$$}\lesssim 13.5$$ and $$\log N (\rm{O\,{\small V}})/\mbox{$${\rm cm^{-2}}$$}\lesssim 13.3$$. Environmental properties of the galaxies, including galaxy overdensities, the total stellar mass and gravitational potential summed over all neighbours, and the presence of local ionizing sources, are found to have a significant impact on the observed CGM absorption properties. Specifically, massive galaxies and galaxies in overdense regions exhibit a higher rate of incidence of absorption. The CGM absorption properties in galaxy groups appear to be driven by the galaxy closest to the QSO sightline, rather than by the most massive galaxy or by mass-weighted properties. We introduce a total projected gravitational potential ψ, defined as −ψ/G = ∑Mhalo/dproj summed over all group members, to characterize the galaxy environment. This projected gravitational potential correlates linearly with the maximum density detected in each sightline (i.e. a power-law slope of $$0.95_{-0.14}^{+0.15}$$), consistent with higher pressure gas being confined in deeper gravitational potential wells. In addition, we find that the radial profile of cool gas density exhibits a decline from the inner regions to the outskirts, and the amplitude is consistent with the cool gas being in pressure balance with the hot halo. Finally, we note that the ionizing flux from nearby galaxies can elevate the N(H i)/N(He i) ratio, which provides a unique diagnostic of possible local sources contributing to the ionizing radiation field. 

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5. Toward Basing Cryptography on the Hardness of EXP

   https://doi.org/10.1145/3587167  

   Liu, Yanyi; Pass, Rafael (May 2023, Communications of the ACM)

   Let Kt ( x ) denote the Levin-Kolmogorov Complexity of the string x , and let MKtP denote the language of pairs ( x , k ) having the property that Kt ( x ) ≤ k. We demonstrate that: • MKtP ∉ Heur neg BPP (i.e., MKtP is two-sided error mildly average-case hard) iff infinitely-often OWFs exist. • MKtP ∉ Avg neg BPP (i.e., MKtP is errorless mildly average-case hard) iff EXP ≠ BPP. Taken together, these results show that the only "gap" toward getting (infinitely-often) OWFs from the assumption that EXP ≠ BPP is the seemingly "minor" technical gap between two-sided error and errorless average-case hardness of the MKtP problem. 

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