Subtypes of renal cell carcinoma: MRI and pathological features

Renal cell carcinoma (RCC) is the most common malignant tumor involving the kidney. Determining the subtypes of renal cell carcinoma is among the major goals of preoperative radiological work-up. Among all modalities, magnetic resonance imaging (MRI) has several advantages, such as inherent soft tissue contrast, detection of lipid and blood products, and excellent sensitivity to detect small amounts of intravenous contrast, which facilitate the discrimination of subtypes of RCC. In this article, we review MRI and pathological features used for determining the main histologic subtypes of RCC, including clear cell, papillary, collecting duct, chromophobe, multilocular cystic, and unclassified RCC

Hierarchical Porous TiO₂ Embedded Unsymmetrical Zinc–Phthalocyanine Sensitizer for Visible-Light-Induced Photocatalytic H₂ Production

In this study, a novel visible-light-driven photocatalyst was designed based on unsymmetrical zinc–phthalocyanine photosensitizer on hierarchical porous TiO₂ (HPT) semiconductor. The HPT material has been prepared by a simple self-formation route. The present work successfully uses zinc phthalocyanine with spectral response extended to 700 nm triggers light harvesting center and HPT semiconductors for high photocatalytic H₂ production. This novel unsymmetrical zinc–phthalocyanine (PCH001) containing three <i>tert</i>-butyl and two carboxylic acid groups that act as “push” and “pull” electron transfer properties from the excited dye to the TiO₂ conduction band. The carboxylic group in the sensitizer serves as an anchoring group on to the surface of TiO₂ and to provide intimate electronic coupling between its excited-state wave function and the conduction-band manifold of the semiconductor. The excellent photophysical properties was governed further by choosing three <i>tert</i>-butyl groups which tuned the LUMO level of the sensitizer that provides directionality in the excited state in addition to low aggregation and high solubility. The Zn-PCH@TiO₂ composites exhibited promising activity and enhanced stability a photocatalytic system for visible-light-induced hydrogen production from water. The photocatalyst (HPT-0.25) shows H₂ production yield 2260 μmol and high turnover number (TON 18080) under visible/near IR light irradiation. Moreover, HPT-0.25 photocatalyst shows a broad visible/NIR light responsive range (400–800 nm) with high apparent quantum yields (AQY) of 7.15, 2.70, 11.57, 3.90, and 0.50% under λ = 420, 550, 690, 730, and 800 nm monochromatic light irradiation, respectively. The present work gives a new advance toward efficient solar energy conversion with promising visible/near IR light-driven photocatalytic activity

High-efficiency organic solar cells prepared using a halogen-free solution process

Although the power conversion efficiency (PCE) of organic photovoltaic (OPV) devices has recently improved to more than 16%, halogenated solution processes are typically employed to obtain optimal performance. However, halogenated processing is harmful to health and the environment, which can be a significant obstacle to commercialization. Therefore, development of active materials processable under halogen-free conditions is of great importance in this field. In this study, a 16.04% OPV device, processed under halogen-free conditions, is developed by employing a new active-blend system, PBDTTPD-HT:BTP-2F-BO. It is highly soluble in halogen-free solvents, forming a preferential bulk-heterojunction morphology. The PBDTTPD-HT:BTP-2F-BO device achieves a PCE comparable with current state-of-the-art devices based on PBDB-TF:BTP-4F (also known as PM6:Y6) using a conventional halogenated process (16.40% versus 16.33%). Furthermore, it demonstrates a significantly higher PCE than the PBDB-TF:BTP-4F device with a halogen-free process (16.04% versus 9.70%)

Near-infrared absorbing unsymmetrical Zn(II) phthalocyanine for dye-sensitized solar cells

Unsymmetrical Zn phthalocyanine consisting of six S-aryl groups at α-positions and a carboxy anchoring group at β-position has been designed and synthesized for dye-sensitized solar cells (DSCs) applications. The unsymmetrical phthalocyanine has been characterized by elemental, MALDI-MS, IR, 1H NMR, UV–Vis, fluorescence (steady-state & lifetime) and electrochemical (including spectroelectrochemical) methods. The Q-band absorption maxima of the unsymmetrical phthalocyanine was red-shifted due to the presence of S-aryl groups, which destabilizes the HOMO level consistent with electrochemical and in situ spectroelectrochemical studies. The redox processes are assigned to the macrocyclic ring-based electron transfer processes, the LUMO of the unsymmetrical phthalocyanines lies above the TiO2 conduction band, and the HOMO is well below the potential of the I−/I3− redox electrolyte. The experimental results are supported by DFT/TD-DFT studies. The new unsymmetrical phthalocyanines was tested in DSCs using I−/I3− redox electrolyte system

D–π–A system based on zinc porphyrin dyes for dye-sensitized solar cells: Combined experimental and DFT–TDDFT study

A series of four new porphyrin-furan dyads were designed and synthesized by having anchoring group either at meso-phenyl or pyrrole-β position of a zinc porphyrin based on donor–π–acceptor (D–π–A) approach. The porphyrin macrocycle acts as donor, furan hetero cycle acts as π-spacer and either cyanoacetic acid or malonic acid group acts as acceptor. These dyads were fully characterized by UV–Visible, 1H NMR, MALDI-MS and fluorescence spectroscopies and cyclic voltammetry. Both of the observed and TD-DFT simulated UV–Vis spectra has strong correlation which validate and confirm the synthesized dyads and theoretical method for this type of compounds. Both soret and Q-bands are red shifted in the case of pyrrole-β substituted dyads. The redox potentials of all four dyads are not altered in comparison with their individual constituents. The dyads were tested in dye sensitized solar cells and found pyrrole-β substituted zinc porphyrins are showing better performance in comparison with the corresponding meso-phenyl dyads. Optical band gap, Natural bonding, and Molecular bonding orbital (HOMO–LUMO) analysis are in favour of pyrrole-β substituted zinc porphyrins contrast to meso-phenyl dyads

D–π–A system based on zinc porphyrin dyes for dye-sensitized solar cells: Combined experimental and DFT–TDDFT study

A series of four new porphyrin-furan dyads were designed and synthesized by having anchoring group either at meso-phenyl or pyrrole-β position of a zinc porphyrin based on donor–π–acceptor (D–π–A) approach. The porphyrin macrocycle acts as donor, furan hetero cycle acts as π-spacer and either cyanoacetic acid or malonic acid group acts as acceptor. These dyads were fully characterized by UV–Visible, 1H NMR, MALDI-MS and fluorescence spectroscopies and cyclic voltammetry. Both of the observed and TD-DFT simulated UV–Vis spectra has strong correlation which validate and confirm the synthesized dyads and theoretical method for this type of compounds. Both soret and Q-bands are red shifted in the case of pyrrole-β substituted dyads. The redox potentials of all four dyads are not altered in comparison with their individual constituents. The dyads were tested in dye sensitized solar cells and found pyrrole-β substituted zinc porphyrins are showing better performance in comparison with the corresponding meso-phenyl dyads. Optical band gap, Natural bonding, and Molecular bonding orbital (HOMO–LUMO) analysis are in favour of pyrrole-β substituted zinc porphyrins contrast to meso-phenyl dyads