Atmospheric Reanalyses-Recent Progress and Prospects for the Future. A Report from a Technical Workshop, April 2010

In April 2010, developers representing each of the major reanalysis centers met at Goddard Space Flight Center to discuss technical issues - system advances and lessons learned - associated with recent and ongoing atmospheric reanalyses and plans for the future. The meeting included overviews of each center s development efforts, a discussion of the issues in observations, models and data assimilation, and, finally, identification of priorities for future directions and potential areas of collaboration. This report summarizes the deliberations and recommendations from the meeting as well as some advances since the workshop

Pressure Induced Crossover between a Ferromagnetic and a Canted Antiferromagnetic State for [Bis(pentamethylcyclopentadienyl)-iron(III)][Tetracyanoethenide], [FeCp₂*][TCNE]

The reversible hydrostatic pressure dependent DC magnetic behavior of the ferromagnetically ordered electron transfer salt [Fe^IIICp₂*]^•+[TCNE]^•– (Cp* = pentamethylcyclopentadienide; TCNE = tetracyanoethylene) was studied up to 12.2 kbar. A significant departure from the ambient pressure ferromagnetic behavior was observed under pressure. The temperature dependent magnetization data were typical of a ferromagnet at ambient pressure but exhibited an extreme reduction with increasing applied pressure, while metamagnetic-like behavior was evident in the field dependent magnetization data at 4.2 kbar and above. Hence, the decrease of the intermolecular separations due to increasing pressure enhances the nearest neighbor couplings, leading to an increase in magnetic ordering temperature, <i>T</i>_c. Furthermore, the presence of a metamagnetic-like behavior suggests an increase of the antiferromagnetic contribution to the interchain interactions. The low field magnetization data indicate that spin canting is induced by pressure, leading to a canted antiferromagnetic phase with a much lower magnetization than the low-pressure ferromagnetic state. This unprecedented magnetic behavior is consistent with the field, temperature, and pressure dependences of the magnetization below 20 K

A Mean-Field Analysis of the Exchange Coupling (<i>J</i>) for Noncubic Prussian Blue Analogue Magnets

Mean field expressions based on the simple Heisenberg model were derived to correlate the intra- and interlayer exchange couplings to the critical temperatures, <i>T</i>_c, for three metallocyanide-based magnets with extended 2- and 3-D structure types. These expressions were used to estimate the exchange coupling, <i>J</i>, for 2-D ferrimagnetic [NEt₄]₂Mn^II₃(CN)₈, 3-D antiferromagnetic [NEt₄]­Mn^II₃(CN)₇, and 3-D antiferromagnetic interpenetrating 3-D Mn^II(CN)₂. The type and magnitude of the exchange coupling are in accord with the previously reported magnetic data

Low temperature structures and magnetic interactions in the organic-based ferromagnetic and metamagnetic polymorphs of decamethylferrocenium 7,7,8,8-tetracyano- p-quinodimethanide, [FeCp*2]¿+[TCNQ]¿−

To identify the genesis of the differing magnetic behaviors for the ferro- (FO) and metamagnetic (MM) polymorphs of [FeCp*2][TCNQ] (Cp* = pentamethylcyclopentadienide; TCNQ = 7,7,8,8-tetracyano-p-quinodimethane) the low temperature (18 ± 1 K) structures of each polymorph were determined from high-resolution synchrotron powder diffraction data. Each polymorph possesses chains of alternating S = 1/2 [FeCp*2]˙+ cations and S = 1/2 [TCNQ]˙+, but with differing relative orientations. These as well as an additional paramagnetic polymorph do not thermally interconvert. In addition, the room and low (<70 ± 10 K) temperature structures of the MM polymorph, MMRT and MMLT, respectively, differ from that previously reported at 167 K (−106 °C) MM structure, and no evidence of either phase transition was previously noted even from the magnetic data. This transition temperature and enthalpy of this phase transition for MMRT ⇌ MM was determined to be 226.5 ± 0.4 K (−46.7 ± 0.4 °C) and 0.68 ± 0.04 kJ mol−1 upon warming, respectively, from differential calorimetry studies (DSC). All three MM phases are triclinic (P[1 with combining macron]) with the room temperature phase having a doubled unit cell relative to the other two. The lower temperature phase transition involves a small rearrangement of the molecular ions and shift in lattice parameters. These three MM and FO polymorphs have been characterized and form extended 1-D chains with alternating S = 1/2 [FeCp*2]˙+ cations, and S = 1/2 [TCNQ]˙− anions, whereas the fifth, paramagnetic (P) polymorph possesses S = 0 π-[TCNQ]22− dimers. At 18 ± 1 K the intrachain Fe⋯Fe separations are 10.738(2) and 10.439(3) Å for the FO and MMLT polymorphs, respectively. The key structural differences between FO and MMLT at 18 ± 1 K are the 10% shorter interchain N⋯N and the 2.8% shorter intrachain Fe⋯Fe separation present for MMLT. Computational analysis of all nearest-neighbor spin couplings for the 18 K structures of FO and MMLT indicates that the intrachain [FeCp*2]˙+⋯[TCNQ]˙− spin couplings (H = −2Si·Sj) are the strongest (4.95 and 6.5 cm−1 for FO and MMLT, respectively), as previously hypothesized, and are ferromagnetic due to their S = 1/2 spins residing in orthogonal orbitals. The change in relative [TCNQ]˙−⋯[TCNQ]˙− orientations leads to a computed change from the ferromagnetic interaction (0.2 cm−1) for FO to an antiferromagnetic interaction (−0.1 cm−1) for MMLT in accord with its observed antiferromagnetic ground state. Hence, the magnetic ground state cannot be solely described by the dominant magnetic interactions

Pressure Induced Crossover between a Ferromagnetic and a Canted Antiferromagnetic State for [Bis(pentamethylcyclopentadienyl)- iron(III)][Tetracyanoethenide], [FeCp2*][TCNE]

The reversible hydrostatic pressure dependent DC magnetic behavior of the ferromagnetically ordered electron transfer salt [FeIIICp2*]*+[TCNE]*− (Cp* = pentamethylcyclopentadienide; TCNE = tetracyanoethylene) was studied up to 12.2 kbar. A significant departure from the ambient pressure ferromagnetic behavior was observed under pressure. The temperature dependent magnetization data were typical of a ferromagnet at ambient pressure but exhibited an extreme reduction with increasing applied pressure, while metamagnetic-like behavior was evident in the field dependent magnetization data at 4.2 kbar and above....

Vascular Problems of the Pelvis

Regardless of the gender, the human pelvis represents a complex anatomic region shared by the organs of the gastrointestinal and genitourinary tracts and the reproductive system. All these structures are included in a rigid bone case which also harbors the intricate neurovascular network that crosses over the pelvic area in direction to the lower limbs. The adequate approach of the diseases arising in the pelvic vascular network is difficult requiring precise anatomical knowledge and often the collaboration of interdisciplinary teamwork. The present chapter describes in detail the pelvic vascular anatomy and also provides a full discussion of both the tumor-related and tumor-unrelated diseases affecting these vascular structures

Sparsentan in patients with IgA nephropathy: a prespecified interim analysis from a randomised, double-blind, active-controlled clinical trial

Background: Sparsentan is a novel, non-immunosuppressive, single-molecule, dual endothelin and angiotensin receptor antagonist being examined in an ongoing phase 3 trial in adults with IgA nephropathy. We report the prespecified interim analysis of the primary proteinuria efficacy endpoint, and safety. Methods: PROTECT is an international, randomised, double-blind, active-controlled study, being conducted in 134 clinical practice sites in 18 countries. The study examines sparsentan versus irbesartan in adults (aged ≥18 years) with biopsy-proven IgA nephropathy and proteinuria of 1·0 g/day or higher despite maximised renin-angiotensin system inhibitor treatment for at least 12 weeks. Participants were randomly assigned in a 1:1 ratio to receive sparsentan 400 mg once daily or irbesartan 300 mg once daily, stratified by estimated glomerular filtration rate at screening (30 to 1·75 g/day). The primary efficacy endpoint was change from baseline to week 36 in urine protein-creatinine ratio based on a 24-h urine sample, assessed using mixed model repeated measures. Treatment-emergent adverse events (TEAEs) were safety endpoints. All endpoints were examined in all participants who received at least one dose of randomised treatment. The study is ongoing and is registered with ClinicalTrials.gov, NCT03762850. Findings: Between Dec 20, 2018, and May 26, 2021, 404 participants were randomly assigned to sparsentan (n=202) or irbesartan (n=202) and received treatment. At week 36, the geometric least squares mean percent change from baseline in urine protein-creatinine ratio was statistically significantly greater in the sparsentan group (-49·8%) than the irbesartan group (-15·1%), resulting in a between-group relative reduction of 41% (least squares mean ratio=0·59; 95% CI 0·51-0·69; p<0·0001). TEAEs with sparsentan were similar to irbesartan. There were no cases of severe oedema, heart failure, hepatotoxicity, or oedema-related discontinuations. Bodyweight changes from baseline were not different between the sparsentan and irbesartan groups. Interpretation: Once-daily treatment with sparsentan produced meaningful reduction in proteinuria compared with irbesartan in adults with IgA nephropathy. Safety of sparsentan was similar to irbesartan. Future analyses after completion of the 2-year double-blind period will show whether these beneficial effects translate into a long-term nephroprotective potential of sparsentan. Funding: Travere Therapeutics