Reconciling results of 2019 and 2020 stellar occultations on Pluto's atmosphere. New constraints from both the 5 September 2019 event and consistency analysis

A stellar occultation by Pluto on 5 September 2019 yielded positive detections at two separate stations. Using an approach consistent with comparable studies, we derived a surface pressure of $11.478 \pm 0.55~\mathrm{\mu bar}$ for Pluto's atmosphere from the observations of this event. In addition, to avoid potential method inconsistancies highlighted by Sicardy et al. when comparing with historical pressure measurements, we reanalyzed the data by 15 August 2018 and 17 July 2019 events, respectively. All the new measurements provide a bridge between the two different perspectives on the pressure variation since 2015: a rapid pressure drop from previous studies of the 15 August 2018 and 17 July 2019 events and a plateau phase from that of the 6 June 2020 event. The pressure measurement from the 5 September 2019 event aligns with those from 2016, 2018, and 2020, supporting the latter perspective. While the measurements from the 4 June 2011 and 17 July 2019 events suggest probable V-shaped pressure variations unaccounted for by the volatile transport model (VTM) from Meza et al., the VTM remains applicable on average. And, the validity of the V-shaped variations is debatable due to the stellar faintness of the 4 June 2011 event and the grazing single-chord geometry of the 17 July 2019 event. To reveal and understand all significant pressure variations of Pluto's atmosphere, it is essential to provide constraints on both short-term and long-term evolutions of the interacting atmosphere and surface by continuous pressure monitoring through occultation observations, whenever possible, complemented by frequent spectroscopy and photometry of the surface.Comment: Accepted for publication in Astronomy & Astrophysics. 10 pages, 6 figure

Rapamycin Inhibits the Growth and Collagen Production of Fibroblasts Derived from Human Urethral Scar Tissue

Rapamycin can inhibit fibroblast proliferation, collagen accumulation, and urethral stricture in rabbits. Transforming growth factor-beta-1 (TGF-β1) signaling, with downstream recruitment of Smad2, is known to promote fibrosis. This in vitro study examined the effects of rapamycin on fibroblasts derived from human urethral scar tissue (FHUS) and investigated the possible mechanism with respect to regulation of TGF-β1 signaling. FHUS were cultured from urethral scar tissues collected from four patients with urethral stricture. The cells were exposed to different concentrations of rapamycin (0, 10, 20, 40, 80, or 160 ng/ml) for 24 or 48 hours. Cell growth was assessed by the MTT assay. Collagen content was measured based on hydroxyproline levels. The mRNA expressions of Smad2, eIF-4E, and alpha-1 chains of collagen types I and III (Col1α1 and Col3α1) were determined by semiquantitative reverse-transcription PCR. The protein expressions of Smad2, phospho-Smad2, and eIF-4E were evaluated by western blot. Rapamycin caused a concentration-dependent inhibition of FHUS growth at 24 and 48 hours (P<0.01). Rapamycin decreased total collagen content (P<0.01), collagen content per 105 cells (P<0.05), and mRNA expressions of Col1α1 and Col3α1 (P<0.05) in a concentration-dependent manner. Rapamycin elicited concentration-dependent reductions in the mRNA (P<0.05) and protein (P<0.01) expressions of Smad2 and eIF-4E. The two highest concentrations of rapamycin also enhanced phospho-Smad2 levels (P<0.01). In conclusion, the present study confirmed that rapamycin may reduce the growth and collagen production of FHUS, possibly through inhibition of TGF-β1 signaling

Urethral diameter and lumen reduction of rabbits in different treated groups.

<p>•Normal referred to diameter of urethra 1 cm distal to the injured site of all rabbits in this study.</p><p>*<i>P</i> = 0.218 compared to D_L, <i>P</i><0.01 compared to C and Normal.</p><p>**<i>P</i><0.01 compared to C and Normal.</p><p>***<i>P</i><0.01 compared to Normal.</p>#<p><i>P</i> = 0.010 compared to D_L, <i>P</i><0.01 compared to C.</p>##<p><i>P</i><0.01 compared to C.</p><p>Urethral diameter and lumen reduction of rabbits in different treated groups.</p

Representative microphotographs of urethral cross section at stricture site (stained by Sirius red).

<p>A Urethral cross section of rabbit in D_H group. Note a large urethral lumen with light submucosa collagen staining. B Urethral cross section of rabbit in D_L group. Note large urethral lumen with light submucosa collagen staining. C Urethral cross section of rabbit in C group. Note almost atresic urethra with deep collagen staining.</p

Urethral cross section at stricture sites (hematoxylin and eosin staining) Original magnifications, 400×.

<p>A Urethral cross section of rabbit in D_H group. Note little fibrosis tissue around urethral epithelium. B Urethral cross section of rabbit in D_L group. Note fibrosis formation around submucosa layer. C Urethral cross section of rabbit in C group. Note wide fibrous tissues distributed from epithelium to muscular layer.</p

Urethral stricture formation under urethroscopy.

<p>A Urethroscopy of rabbit in D_H group. Note no significant urethral stricture formation and F13 urethroscopy could easily pass through. B Urethroscopy of rabbit in D_L group. Note urethral stricture formation and F13 urethroscopy could hardly pass through. C Urethroscopy of rabbit in C group. Note severe urethral stricture formation, stopping F13 urethroscopy pass through.</p

Ferroelectric anomaly of perovskite layer structured Pb²⁺‐doped Sr₂Nb₂O₇ ceramics

From Crossref journal articles via Jisc Publications RouterHistory: received 2023-10-18, accepted 2023-12-15, epub 2024-01-09, issued 2024-01-09, published 2024-01-09Article version: VoRPublication status: PublishedFunder: National Key Research and Development Program of China; FundRef: https://doi.org/10.13039/10.13039/501100012166; Grant(s): 2022YFB3204000Funder: National Natural Science Foundation of China; FundRef: https://doi.org/10.13039/10.13039/501100001809; Grant(s): 51972322AbstractThe spontaneous polarization of perovskite layer structured Sr2Nb2O7 ferroelectrics (FEs) is originated from mainly the oxygen octahedral rotations and partially the displacement of Sr2+ ions. However, there is FE anomaly of showing the typical characteristics of antiferroelectric (AFE)‐like behavior with double polarization–electric field hysteresis loops of Sr2Nb2O7 ceramics by Pb doping. Here, combinations of low frequency and sub‐terahertz band dielectric measurements under applied DC field reveal field‐induced transition from AFE to FE structure. Temperature dependence of dielectric constant suggested a second‐order phase transition near 215°C, which further supported by the lattice parameters and thermal expansion coefficient extracted from the variable temperature X‐ray diffraction in the heating and cooling processes. The selected area electron diffraction results show no new superlattice spots are observed along [1 0 0] zone axis related to c direction. We proposed a model based on octahedral tilting/rotation that accounted for the incommensurate lattice modulation in the c direction for Sr2Nb2O7 system by Pb doping. All the results show AFE‐like behavior be likely to origin from the electron structures of Pb2+ with a 6s2 lone pair. Our results gave us a new concept provide possibilities for the design of AFE‐like materials in layer structured compounds with super high FE Curie point

Ferroelectric anomaly of perovskite layer structured Pb²⁺‐doped Sr₂Nb₂O₇ ceramics

From Crossref journal articles via Jisc Publications RouterHistory: received 2023-10-18, accepted 2023-12-15, epub 2024-01-09, issued 2024-01-09, published 2024-01-09Article version: VoRPublication status: PublishedFunder: National Key Research and Development Program of China; FundRef: https://doi.org/10.13039/10.13039/501100012166; Grant(s): 2022YFB3204000Funder: National Natural Science Foundation of China; FundRef: https://doi.org/10.13039/10.13039/501100001809; Grant(s): 51972322AbstractThe spontaneous polarization of perovskite layer structured Sr2Nb2O7 ferroelectrics (FEs) is originated from mainly the oxygen octahedral rotations and partially the displacement of Sr2+ ions. However, there is FE anomaly of showing the typical characteristics of antiferroelectric (AFE)‐like behavior with double polarization–electric field hysteresis loops of Sr2Nb2O7 ceramics by Pb doping. Here, combinations of low frequency and sub‐terahertz band dielectric measurements under applied DC field reveal field‐induced transition from AFE to FE structure. Temperature dependence of dielectric constant suggested a second‐order phase transition near 215°C, which further supported by the lattice parameters and thermal expansion coefficient extracted from the variable temperature X‐ray diffraction in the heating and cooling processes. The selected area electron diffraction results show no new superlattice spots are observed along [1 0 0] zone axis related to c direction. We proposed a model based on octahedral tilting/rotation that accounted for the incommensurate lattice modulation in the c direction for Sr2Nb2O7 system by Pb doping. All the results show AFE‐like behavior be likely to origin from the electron structures of Pb2+ with a 6s2 lone pair. Our results gave us a new concept provide possibilities for the design of AFE‐like materials in layer structured compounds with super high FE Curie point

Efficient production of Aschersonia placenta protoplasts for transformation using optimization algorithms

Aschersonia placenta is a highly effective pathogen of whiteflies and scale insects. Few genetic tools, however, are currently available for this organism. Here we report on the conditions for the production of transformable A. placenta protoplasts using an optimized protocol based on the response surface method (RSM). Critical parameters for protoplast production were modelled by using a Box-Behnken design (BBD) involving three levels of three variables, and subsequently experimentally verified in its predictability of protoplast production (R2 = 0.9465). The optimized conditions resulted in the highest yield of protoplasts (4.41 ± 0.02 ×107 cells/ml of culture, mean ± SE) when fungal cells were treated with 26.1 mg/ml of lywallzyme for 4 h of digestion, and subsequently allowed to recover for 64.6 h in 0.7 M NaCl-Tris buffer. The latter used as an osmotic stabilizer. The yield of protoplasts was approximately 10-fold higher than that of the non-optimized conditions. Generated protoplasts were transformed with vector PbarGPE containing bar gene as the selection marker. Transformation efficiency was 300 colonies/g DNA/107 protoplasts, and integration of the vector DNA was confirmed by PCR. The results show that rational design strategies (RSM and BBD methods) are useful to increase the production of fungal protoplasts for a variety of downstream applications.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author