PtCl2 mediated peripheral transformation of carbatriphyrin(3.1.1) into a meso-fused β-β' dimer and its monomer analogue

An unprecedented formation of a meso-fused β-β' carbaporphyrin dimer and its monomer with a keto group was described. These analogues were synthesized from carbatriphyrin(3.1.1.) by a metal assisted strategy using PtCl2 salt in a single step without any prefunctionalized precursors. Upon dimerization, the monomeric ligand with a dianionic core is transformed into a dimeric structure with unique trianionic cores.

A semi-automated brain atlas-based analysis pipeline for c-Fos immunohistochemical data

BACKGROUND

The use of immunohistochemistry to quantify neural markers in various brain regions is a staple of neuroscience research. Numerous programs exist to automate quantification, but manual assignment of regions of interest (ROIs) within individual brain sections remains time consuming and can introduce interobserver variability.

NEW METHOD

We have developed a novel open source FIJI-based immunohistochemical data analysis pipeline, Atlas-Based Analysis (ABA). ABA uses landmark-based image warping to adjust the experimental image to closely align with a published rat brain atlas. c-Fos positive cells are then quantified within predetermined ROI coordinates derived from the brain atlas. Image warping adjusts for natural variation in brain sections to ensure reliable alignment of ROIs for data analysis. This pipeline can be adapted for new atlases, landmarks, ROIs, and quantification measurements.

RESULTS

ABA permits rapid quantification of immunoreactivity in multiple ROIs and produces results with high levels of interobserver consistency.

COMPARISON WITH EXISTING METHODS

Compared to manual ROI designation, ABA reduces total analysis time by ∼70%. With correct use of landmarks for image warping, ABA produces similar results to manually drawn ROIs, results in no interobserver variability, and maintains c-Fos+ pixel dimensions.

CONCLUSIONS

ABA reduces time to obtain reliable results when performing automated immunoreactivity quantification and allows multiple users to analyze data without compromising the reliability of data obtained.

Utility of Pre-Hematopoietic Cell Transplantation Sinus CT Screening in Children and Adolescents

BACKGROUND AND PURPOSE

The clinical benefit of pre-hematopoietic cell transplantation sinus CT screening remains uncertain, while the risks of CT radiation and anesthesia are increasingly evident. We sought to re-assess the impact of screening sinus CT on pretransplantation patient management and prediction of posttransplantation invasive fungal rhinosinusitis.

MATERIALS AND METHODS

Pretransplantation noncontrast screening sinus CTs for 100 consecutive patients (mean age, 11.9 ± 5.5 years) were graded for mucosal thickening (Lund-Mackay score) and for signs of noninvasive or invasive fungal rhinosinusitis (sinus calcification, hyperattenuation, bone destruction, extrasinus inflammation, and nasal mucosal ulceration). Posttransplantation sinus CTs performed for sinus-related symptoms were similarly graded. Associations of Lund-Mackay scores, clinical assessments, changes in pretransplantation clinical management (additional antibiotic or fungal therapy, sinonasal surgery, delayed transplantation), and subsequent development of sinus-related symptoms or invasive fungal rhinosinusitis were tested (exact Wilcoxon rank sums, Fisher exact test, significance P < .05).

RESULTS

Mean pretransplantation screening Lund-Mackay scores (n = 100) were greater in patients with clinical symptoms (8.07 ± 6.00 versus 2.48 ± 3.51, P < .001) but were not associated with pretransplantation management changes and did not predict posttransplantation sinus symptoms (n = 21, P = .47) or invasive fungal rhinosinusitis symptoms (n = 2, P = .59).

CONCLUSIONS

Pre-hematopoietic cell transplantation sinus CT does not meaningfully contribute to pretransplantation patient management or prediction of posttransplantation sinus disease, including invasive fungal rhinosinusitis, in children. The risks associated with CT radiation and possible anesthesia are not warranted in this setting.

Isosmaragdyrin with an N3C2 core: stabilization of Rh(i) and organo-Pt(ii) complexes

Isosmaragdyrin with an N₃C₂ core is successfully achieved by introducing a 2,6-di-m-phenylpyridine unit. The core is utilized to stabilize the Rh(i) ion in the N-Rh(i)-N bonding mode and the Pt(ii) ion in the (N^C)N fashion to form an unsymmetrical pincer-type organometallic complex.

Structurally Isomerized Bis-Biphenyl Moieties Embedded in Hexaphyrin(3.1.1.3.1.1) and Octaphyrin(1.1.1.0.1.1.1.0)

An o-p-biphenyl moiety-incorporated 32π hexaphyrin(3.1.1.3.1.1) is successfully achieved. Replacing ortho with meta connectivity in the biphenyl unit of hexaphyrin leads to the formation of its structural isomer, octaphyrin(1.1.1.0.1.1.1.0). Spectral and structural analyses reveal the lack of planarity in hexaphyrin and the presence of an m-arene unit in octaphyrin, thus affording nonaromatic characteristics.

Engineering diformyl diaryldipyrromethane into a molecular keypad lock

A diaryldipyrromethane-based acyclic system acts as a photolabile sequential chemosensor for both anions and cations via ESIDPT and deprotonation, which is engineered into a fluorescent molecular keypad lock system.

Protonation-Triggered Hückel and Möbius Aromatic Transformations in Nonaromatic Core-Modified [30]Hexaphyrin(2.1.1.2.1.1) and Annulated [28]Hexaphyrin(2.1.1.0.1.1)

Two 1,2-diphenyl-1,2-dithienylethene-embedded hexaphyrins 6 and 8 containing 30π and 28π electrons, respectively, in conjugation exhibit nonaromatic characteristics. Compound 6 shows an unusual bond length equalization in its electronic structure. However, on protonation, 6 exhibits Hückel aromatic characteristics while 8 shows Möbius aromatic characteristics. The changes in aromaticity are accompanied by change in conformation from a figure-eight/twisted structure to an open extended structure.