A Highly Active Cobalt Catalyst for the General and Selective Hydrogenation of Aromatic Heterocycles

Nanostructured earth abundant metal catalysts that mediate important chemical reactions with high efficiency and selectivity are of great interest. This study introduces a synthesis protocol for nanostructured earth abundant metal catalysts. Three components, an inexpensive metal precursor, an easy to synthesize N/C precursor, and a porous support material undergo pyrolysis to give the catalyst material in a simple, single synthesis step. By applying this catalyst synthesis, a highly active cobalt catalyst for the general and selective hydrogenation of aromatic heterocycles could be generated. The reaction is important with regard to organic synthesis and hydrogen storage. The mild reaction conditions observed for quinolines permit the selective hydrogenation of numerous classes of N-, O- and S-heterocyclic compounds such as: quinoxalines, pyridines, pyrroles, indoles, isoquinoline, aciridine amine, phenanthroline, benzofuranes, and benzothiophenes

Evaluation of the consistency ratios of cervical smear, cervical biopsy and conization results

Objectives: Possible discrepancies between the cervical smear, biopsy histology and loop electrosurgical excision procedure (LEEP) results of the same patient is a matter of debate in the literature. In this study, we investigate the degree to which these results differ, and the clinical reasons for these differences. Material and methods: With a retrospective design, cervical smear, cervical biopsy and LEEP results of patients were compared in terms of consistency. One hundred sixty-four patients who underwent till LEEP procedure due to pathologic initial smear and biopsy results between January 2015 and March 2020 were included in the study. Results: Exact diagnosis discrepancy and high grade squamous intraepithelial lesion (HSIL) discrepancy were 78.9% and 50.0% between smear and cervical biopsy, 64.6% and 31.7% between cervical smear and LEEP and 43.8% and 28.1% between cervical biopsy and LEEP results, respectively. Age did not affect the consistency rates of pathologic results between smear-biopsy (p = 0.408) and biopsy-LEEP (p = 0.590). However, the probability of the consistency of smear and LEEP results exhibited a statistically significant linear relation with age (OR = 1.043, p = 0.015). HPV infections did not affect the discrepancy between smear-biopsy (p = 0.533), smear-LEEP (p = 1.000) and biopsy-LEEP (p = 0.529) Conclusions: Smear technique has a serious discrepancy and under-diagnosis problem when its results are compared with biopsy and LEEP. The consistency between smear and LEEP results appears to improve with age. When HSIL is evaluated in terms of detection, this discrepancy decreases. A smear test can detect HSIL and carcinoma with a higher accuracy than low-grade lesions

Ultrafast dissolution and creation of bonds in IrTe2 induced by photodoping

The observation and control of interweaving spin, charge, orbital, and structural degrees of freedom in materials on ultrafast time scales reveal exotic quantum phenomena and enable new active forms of nanotechnology. Bond- ing is the prime example of the relation between electronic and nuclear degrees of freedom. We report direct evidence illustrating that photoexcitation can be used for ultrafast control of the breaking and recovery of bonds in solids on unprecedented time scales, near the limit for nuclear motions. We describe experimental and theoretical studies of IrTe2 using femtosecond electron diffraction and density functional theory to investigate bonding instability. Ir-Ir dimerization shows an unexpected fast dissociation and recovery due to the filling of the antibonding dxy orbital. Bond length changes of 20% in IrTe2 are achieved by effectively addressing the bonds directly through this relaxation process. These results could pave the way to ultrafast switching between metastable structures by photoinduced manipulation of the relative degree of bonding in this manner

İstabul Üniversitesi gözlemevi odak düzlemi aygıtı test ve karakterizasyon laboratuvarı

Doğu Anadolu Gözlemevi Odak Düzlemi Aygıtları ve Adaptif Optik Sistemi başlıklı, 2016K121370 numaralı T.C. Kalkınma Bakanlığı projesi ve İstanbul Üniversitesi Rektörlüğü desteğinde yürüyen çalışmalar kapsamında İstanbul Üniversitesi Astronomi ve Uzay Bilimleri Bölümü’nde teleskop odak düzlemi aygıtı test ve karakterizasyon laboratuvarı kurulum çalışmaları başlatılmıştır. Başta DAG Teleskobu olmak üzere ülkemizdeki tüm gözlemevlerine hizmet verebilecek şekilde tasarlanan laboratuvar, CCD kamera, filtre ve odak düzlemi aygıtları için bir test masasına sahip olacaktır. Bu sunumda, laboratuvarın kurulumu ve alımlarında gelinen son noktanın yanı sıra, İstanbul Üniversitesi Fizik Bölümü Nano-Optoelektronik Araştırma Laboratuvarları ile birlikte yapılması planlanan çalışmalar sunulacaktır.Publisher's Versio

Graphene Enclosure of Chemically Fixed Mammalian Cells for Liquid-Phase Electron Microscopy

A protocol is described for investigating the human epidermal growth factor receptor 2 (HER2) in the intact plasma membrane of breast cancer cells using scanning transmission electron microscopy (STEM). Cells of the mammalian breast cancer cell line SKBR3 were grown on silicon microchips with silicon nitride (SiN) windows. Cells were chemically fixed, and HER2 proteins were labeled with quantum dot nanoparticles (QDs), using a two-step biotin-streptavidin binding protocol. The cells were coated with multilayer graphene to maintain a hydrated state, and to protect them from electron beam damage during STEM. To examine the stability of the samples under electron beam irradiation, a dose series experiment was performed. Graphene-coated and non-coated samples were compared. Beam induced damage, in the form of bright artifacts, appeared for some non-coated samples at increased electron dose D, while no artifacts appeared on coated samples

The association of Neuromedin U levels and non-alcoholic fatty liver disease: A comparative analysis

This comprehensive study delves into the potential link between Neuromedin U (NmU) serum levels and the development of non-alcoholic fatty liver disease (NAFLD), a condition of increasing global prevalence and significant public health concern. The research provides a nuanced understanding of the disease's etiology by examining a cohort of 112 participants, including individuals with and without NAFLD. The study meticulously considers a spectrum of variables such as demographic factors, body composition metrics, and blood parameters. Advanced diagnostic tools like Fibroscan® are employed to ascertain NAFLD presence, ensuring accurate and reliable results.The investigation reveals a noteworthy correlation between NAFLD and several risk factors, notably obesity, increased waist and neck circumferences, hypertriglyceridemia, and insulin resistance. These findings underscore the multifactorial nature of NAFLD and its intricate connection with metabolic syndromes. Intriguingly, the study observes lower NmU levels in individuals diagnosed with NAFLD. However, the role of NmU as an independent risk factor for NAFLD remains inconclusive, warranting further investigation. Although triglyceride level was observed to be an independent risk factor for NAFLD, this relationship was not associated with NmU.This research contributes significantly to the existing knowledge on NAFLD, highlighting the disease's complexity and the interplay of various risk factors. It also opens up new avenues for future research, particularly in exploring the role of NmU within the metabolic pathways associated with NAFLD. The insights gained from this study could guide the development of novel diagnostic and therapeutic strategies for NAFLD, addressing a crucial need in contemporary healthcare.In conclusion, the findings of this study not only enhance the understanding of NAFLD's pathophysiology but also emphasize the importance of comprehensive risk factor analysis in the management and prevention of this growing health concern