Tuning the Liquid Crystallinity and Electroluminescence via Sulfonation of S-Annulated Perylene Tetraester.

This study presents a comparative analysis of S-annulated perylene tetraester (PTE-S) and its sulfone (PTE-SO2) analogue. This sulfone modification reduced melting point and stabilized a room temperature columnar rectangular (Colr) phase in contrast to its parent PTE-S which showed a crystalline behaviour at room temperature. This molecular design also leads to red-shifted absorbance and emission in comparison to PTE-S, along with a tuning of photoluminescence from sky blue to green, achieving an impressive quantum yield of 85 %. OLED devices fabricated using PTE-SO2 as emitter material at concentrations of 0.2, 0.5, and 1 wt.% in CBP as host material. A maximum external quantum efficiency (EQE) of 2.9 % was observed with the 0.5 wt.% PTE-SO2 in CBP with CIE coordinates of (0.45, 0.35), accompanied by an orange luminance of 848 cd/m2. Notably, a device with a 0.5 wt% doping concentration of PTE-S demonstrates an EQE of 3.5 %, and cyan luminance of 2,598 cd/m2.

Highly Soluble Ambipolar anti-Perylene-3,4 : 9,10-bis(benzimidazole)s Stabilize a Room-Temperature Columnar Hexagonal Phase.

A new series of highly soluble perylene anti-bis(4,5-dialkoxybenzimidazole)s bearing branched flexible chains stabilizing room temperature columnar hexagonal phase and with balanced ambipolar charge carrier mobility is reported for the first time. Only the anti isomer was successfully separated and characterized. These compounds have a high extinction coefficient, small optical band gap and wide absorption range, thus making them a promising class of ambipolar organic semiconductors capable of self-organizing.

First example of ambipolar naphthalene diimide exhibiting a room temperature columnar phase.

A self-assembled ambipolar organic semiconductor based on naphthalene diimide with low clearing temperature, solution processability, and high molar extinction coefficient, exhibiting a room temperature columnar hexagonal liquid crystalline phase is reported.

Ambipolar Columnar Self-assembled Organic Semiconductors based on Heteroatom bay-Annulated Perylene Bisimides.

Highly electron-deficient heteroatom (N, S, Se) bay-annulated PBIs exhibiting ordered columnar phase over a wide mesomorphic range including ambient temperature are reported in this manuscript. These compounds with six peripheral n-decyloxy chains exhibited absorption spectra with high molar extinction coefficients, electron-deficient nature and self-assembling behaviour. A detailed comparison with the PBIs bearing six peripheral n-decyl chains was also carried out to get the valuable insights on the structure-property relations in this important class of organic semiconductors. Both of the PBI series were tested for their charge carrier mobility by space charge limited current method and found that they exhibit ambipolar conductivity. This is in contrary to the vast body of literature, where most of the PBI based semiconductors exhibit electron transport behaviour. In general, PBIs derived from tri-n-alkyl anilines exhibit higher mobility values than the PBIs derived from tri-n-alkoxy anilines. Especially, the ambipolar S-annulated PBI derived from tri-n-alkyl aniline exhibited highest hole (8.39×10-3  cm2 /V.s) and electron (1.5×10-2  cm2 /V.s) mobility values and promising for the application in organic electronics.

Reproducibility of Cytomorphological Diagnosis and Assessment of Risk of Malignancy of Thyroid Nodules Based on the Bethesda System for Reporting Thyroid Cytopathology: A Tertiary Cancer Center Perspective.

Introduction: The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) was introduced for unifying the terminology and morphologic criteria along with the corresponding risk of malignancy, leading to more consistent management approaches. The aim of this study was to study the utility and reproducibility of TBSRTC in reporting thyroid cytology in a referral cancer center. Methods: The fine-needle aspiration (FNA) of all thyroid nodules were included for a period of 5 years, from January 2016 to December 2021, in this cancer center. They were retrospectively reviewed and recategorized according to TBSRTC by two experienced pathologists. Cytohistopathological correlation was done for the cases which underwent surgical resection. Results: 522 fine-needle aspiration cytology (FNAC) of thyroid swellings were evaluated and categorized according to TBSRTC. There was agreement in the cytological diagnosis of 512 cases, of which 260 (50.78%) were benign lesions, 189 (36.91%) were malignant, 5 (0.97%) were unsatisfactory/nondiagnostic, 41 (8.01%) were follicular neoplasm/suspicious for neoplasm, 13 (2.53%) were suspicious for malignancy, and 4 (0.78%) cases were reported as atypia of undetermined significance. Two cytopathologists were in agreement in 512 cases (98%) of cases. Almost complete concordance was noted in the malignant (99%) and benign categories (98%). Disagreement was seen in 10 cases. Histological follow-up was available in 201 cases with an overall malignancy rate of 62.68% (126/201). Conclusion: TBSRTC proved to be a very simple and effective reporting system for thyroid FNAC, especially in the setting of a cancer center. This enables proper triaging of cases with thyroid masses into those who require surgical intervention and those who can avoid it, thereby preventing unnecessary morbidity.

A Plausible Proposition of CCL20-Related Mechanism in Fusobacterium nucleatum-Associated Oral Carcinogenesis.

OBJECTIVE: The objective of this prospective observational case-control study is to evaluate the prevalence of Fusobacterium nucleatum in the tissues of oral squamous cell carcinoma (OSCC). Reconnoitering the CCL20-related mechanism of carcinogenesis in Fusobacterium nucleatum-positive OSCC is another objective. METHODOLOGY: Tissues from 50 OSCC patients and 30 healthy oral tissues were collected. The prevalence of Fusobacterium nucleatum was evaluated in both tumour and healthy tissue by polymerase chain reaction. The immunohistochemistry of OSCC tissues was conducted to evaluate the difference in the expression of CCL20 between Fusobacterium nucleatum-positive and -negative OSCC tissues. RESULTS: Fusobacterium nucleatum was significantly (p < 0.001) prevalent in OSCC tissues (74%), compared to healthy tissues (26%). No association of Fusobacterium nucleatum or CCL20 immuno-expression with any clinical or histopathological features of OSCC was observed. While the intensity of CCL20 immuno-expression did not differ (p = 0.053), the CCL20-positive cell population was significantly different (p = 0.034) between Fusobacterium nucleatum-positive and -negative OSCC. CONCLUSION: Fusobacterium nucleatum is possibly prevalent in oral cancer tissues in the Indian population. By using immunohistochemistry, this is the first study to propose that the carcinogenesis in Fusobacterium nucleatum-positive OSCC may be CCL20-related. The findings enrich the knowledge of mechanisms involved in Fusobacterium nucleatum-mediated oral carcinogenesis.

Differences in the bacteriome of swab, saliva, and tissue biopsies in oral cancer.

Microbial dysbiosis has been implicated in the pathogenesis of oral cancer. We analyzed the compositional and metabolic profile of the bacteriome in three specific niches in oral cancer patients along with controls using 16SrRNA sequencing (Illumina Miseq) and DADA2 software. We found major differences between patients and control subjects. Bacterial communities associated with the tumor surface and deep paired tumor tissue differed significantly. Tumor surfaces carried elevated abundances of taxa belonging to genera Porphyromonas, Enterobacteriae, Neisseria, Streptococcus and Fusobacteria, whereas Prevotella, Treponema, Sphingomonas, Meiothermus and Mycoplasma genera were significantly more abundant in deep tissue. The most abundant microbial metabolic pathways were those related to fatty-acid biosynthesis, carbon metabolism and amino-acid metabolism on the tumor surface: carbohydrate metabolism and organic polymer degradation were elevated in tumor tissues. The bacteriome of saliva from patients with oral cancer differed significantly from paired tumor tissue in terms of community structure, however remained similar at taxonomic and metabolic levels except for elevated abundances of Streptococcus, Lactobacillus and Bacteroides, and acetoin-biosynthesis, respectively. These shifts to a pro-inflammatory profile are consistent with other studies suggesting oncogenic properties. Importantly, selection of the principal source of microbial DNA is key to ensure reliable, reproducible and comparable results in microbiome studies.

Influence of inter- and intramolecular H-bonding on the mesomorphic and photoswitching behaviour of (E)-4-((4-(hexyloxy)phenyl)diazenyl)-N-phenyl benzamides.

We report on the synthesis, phase behaviour and photoswitching studies of new azo linked rod-shaped molecules. These novel materials consist of three phenyl rings separated by a diazo, amide linkage with a hexyloxy tail and 2,4-substituents at either end of the phenyl ring. The mesomorphic behaviours, phase transition temperature including the enthalpies were characterized by polarizing optical microscope (POM) and differential scanning calorimetry (DSC). The influence of inter- and intramolecular hydrogen bonding on mesomorphic and photoisomerization was studied. Photoisomerization studies carried out both in the solid and liquid phase show the quick E-Z transition with prolonged thermal back relaxation (Z-E) by using UV-Visible spectroscopy. This interesting behaviour could be attributed to the presence of the hexyloxy tail, lateral electron withdrawing group and the influence of inter- or intramolecular hydrogen bonding. Excellent bright and dark states were accomplished using one of these materials in optical storage device. Further tuning is necessary to employ them for real applications.

Salivary bacterial shifts in oral leukoplakia resemble the dysbiotic oral cancer bacteriome.

Objective: While some oral carcinomas appear to arise de novo, others develop within long-standing conditions of the oral cavity that have malignant potential, now known as oral potentially malignant disorders (OPMDs). The oral bacteriome associated with OPMD has been studied to a lesser extent than that associated with oral cancer. To characterize the association in detail we compared the bacteriome in whole mouth fluid (WMF) in patients with oral leukoplakia, oral cancer and healthy controls. Methods: WMF bacteriome from 20 leukoplakia patients, 31 patients with oral cancer and 23 healthy controls were profiled using the Illumina MiSeq platform. Sequencing reads were processed using DADA2, and taxonomical classification was performed using the phylogenetic placement method. Sparse Partial Least Squares Regression Discriminant Analysis model was used to identify bacterial taxa that best discriminate the studied groups. Results: We found considerable overlap between the WMF bacteriome of leukoplakia and oral cancer while a clearer separation between healthy controls and the former two disorders was observed. Specifically, the separation was attributed to 14 taxa belonging to the genera Megaspheara, unclassified enterobacteria, Prevotella, Porphyromonas, Rothia and Salmonella, Streptococcus, and Fusobacterium. The most discriminative bacterial genera between leukoplakia and oral cancer were Megasphaera, unclassified Enterobacteriae, Salmonella and Prevotella. Conclusion: Oral bacteria may play a role in the early stages of oral carcinogenesis as a dysbiotic bacteriome is associated with oral leukoplakia and this resembles that of oral cancer more than healthy controls. Our findings may have implications for developing oral cancer prevention strategies targeting early microbial drivers of oral carcinogenesis.