Unbiased image segmentation assessment toolkit for quantitative differentiation of state-of-the-art algorithms and pipelines.

BACKGROUND: Image segmentation pipelines are commonly used in microscopy to identify cellular compartments like nucleus and cytoplasm, but there are few standards for comparing segmentation accuracy across pipelines. The process of selecting a segmentation assessment pipeline can seem daunting to researchers due to the number and variety of metrics available for evaluating segmentation quality. RESULTS: Here we present automated pipelines to obtain a comprehensive set of 69 metrics to evaluate segmented data and propose a selection methodology for models based on quantitative analysis, dimension reduction or unsupervised classification techniques and informed selection criteria. CONCLUSION: We show that the metrics used here can often be reduced to a small number of metrics that give a more complete understanding of segmentation accuracy, with different groups of metrics providing sensitivity to different types of segmentation error. These tools are delivered as easy to use python libraries, command line tools, Common Workflow Language Tools, and as Web Image Processing Pipeline interactive plugins to ensure a wide range of users can access and use them. We also present how our evaluation methods can be used to observe the changes in segmentations across modern machine learning/deep learning workflows and use cases.

Methanol as a Potential Hydrogen Source for Reduction Reactions Enabled by a Commercial Pt/C Catalyst.

Catalytic reduction reactions using methanol as a transfer hydrogenating agent is gaining significant attention because this simple alcohol is inexpensive and produced on a bulk scale. Herein, we report the catalytic utilization of methanol as a hydrogen source for the reduction of different functional organic compounds such as nitroarenes, olefins, and carbonyl compounds. The key to the success of this transformation is the use of a commercially available Pt/C catalyst, which enabled the transfer hydrogenation of a series of simple and functionalized nitroarenes-to-anilines, alkenes-to-alkanes, and aldehydes-to-alcohols using methanol as both the solvent and hydrogen donor. The practicability of this Pt-based protocol is showcased by demonstrating catalyst recycling and reusability as well as reaction upscaling. In addition, the Pt/C catalytic system was also adaptable for the N-methylation and N-alkylation of anilines via the borrowing hydrogen process. This work provides a simple and flexible approach to prepare a variety of value-added products from readily available methanol, Pt/C, and other starting materials.

Challenges and recent advancements in the transformation of CO2 into carboxylic acids: straightforward assembly with homogeneous 3d metals.

The transformation of carbon dioxide (CO2) into useful chemicals, advanced materials, and energy is a long-standing challenge in both fundamental science and industry. In recent years, utilization of CO2 in the presence of inexpensive and non-negligible environmentally friendly 3d metal-based catalysts (Fe, Mn, Co, Ni, Cu and Ti) has become one of the most attractive topics. Particular attention has been given to the synthesis of carboxylic acids and their derivatives since these molecules serve as key intermediates in the chemical, fertilizer, and pharmaceutical sectors. Considering numerous challenges linked with CO2 reactivity, a number of research groups have recently focused on the transformation of CO2 into carboxylic acids by following thermo-, photo-, and electrochemical strategies. However, facile access to such acids remains a vital challenge in catalysis and in organic synthesis owing to the high stability of the CO2 molecule in which the carbon atom has the highest oxidation state. Another hurdle is to solve the selectivity issue caused by the reaction of different catalytic systems with CO2 in the presence of reactive functional group-containing molecules. Despite all these issues, a wide range of transition metal-based catalysts have been applied in this direction, but owing to their cheaper price and inherent reactivity, 3d metals are at the forefront in the CO2 utilization domain. Considering these, we aim to summarise recent advances (over the past five years) of 3d-metal complexes and their reactivity towards the activation of CO2 for the synthesis of carboxylic acids. Furthermore, we discuss current research trends, knowledge gaps, and invigorating perspectives on future advances.

Commercial Pd/C-Catalyzed N-Methylation of Nitroarenes and Amines Using Methanol as Both C1 and H2 Source.

Herein, we report commercially available carbon-supported-palladium (Pd/C)-catalyzed N-methylation of nitroarenes and amines using MeOH as both a C1 and a H2 source. This transformation proceeds with high atom-economy and in an environmentally friendly way via borrowing hydrogen mechanism. A total of >30 structurally diverse N-methylamines, including bioactive compounds, were selectively synthesized with isolated yields of up to 95%. Furthermore, selective N-methylation and deuteration of nimesulide, a nonsteroidal anti-inflammatory drug, were realized through the late-stage functionalization.