Facile and Reconfigurable Opaque Droplet-based Photomask for Photolithography.

Photolithography is a widely used technology in microfabrication, where photomasks are mostly indispensable. The fabrication of photomasks is generally costly, irreversible, and time-consuming, which limits the prompt delivery of photolithography especially in low-resource settings. Herein, we introduce a facile technique for green and reversible photomask fabrication with opaque droplets, termed as "droplet-based photomask.

Codetection of Proteins and RNAs on Extracellular Vesicles for Pancreatic Cancer Early Diagnosis.

Tumor-derived extracellular vesicles (EVs) carry tumor-specific proteins and RNAs, thus becoming prevalent targets for early cancer diagnosis. However, low expression of EV cargos and insufficient diagnostic power of individual biomarkers hindered EVs application in clinical practice. Herein, we propose a multiplex Codetection platform of proteins and RNAs (Co-PAR) for EVs.

SpiDe-Sr: blind super-resolution network for precise cell segmentation and clustering in spatial proteomics imaging.

Spatial proteomics elucidates cellular biochemical changes with unprecedented topological level. Imaging mass cytometry (IMC) is a high-dimensional single-cell resolution platform for targeted spatial proteomics. However, the precision of subsequent clinical analysis is constrained by imaging noise and resolution.

Photosensitive Hydrogel with Temperature-Controlled Reversible Nano-Apertures for Single-Cell Protein Analysis.

Single cell western blot (scWB) is one of the most important methods for cellular heterogeneity profiling. However, current scWB based on conventional photoactive polyacrylamide hydrogel material suffers from the tradeoff between in-gel probing and separation resolution. Here, a highly sensitive temperature-controlled single-cell western blotting (tc-scWB) method is introduced, which is based on a thermo/photo-dualistic-sensitive polyacrylamide hydrogel, namely acrylic acid-functionalized graphene oxide (AFGO) assisted, N-isopropylacrylamide modified polyacrylamide (ANP) hydrogel.

Multiplex Protein Profiling by Low-Signal-Loss Single-Cell Western Blotting with Fluorescent-Quenching Aptamers.

Single-cell western blotting (scWB) is a prevalent technique for high-resolution protein analysis on low-abundance cell samples. However, the extensive signal loss during repeated antibody stripping precludes multiplex protein detection. Herein, we introduce luorescent-quenching ptamer-based ingle-cell estern lotting (FAS-WB) for multiplex protein detection at single-cell resolution.

Dearomative (4 + 3) Cycloaddition Reactions of 3-Alkenylindoles and 3-Alkenylpyrroles to Afford Cyclohepta[]indoles and Cyclohepta[]pyrroles.

The dearomative (4 + 3) cycloaddition reactions of 3-alkenylindoles with in situ-generated oxyallyl cations furnish cyclohepta[]indoles, functionality-rich frameworks found in many bioactive compounds, including all pentacyclic ambiguine alkaloids. The analogous reactions between oxyallyl cations and 3-alkenylpyrroles afford cyclohepta[]pyrroles. The cycloadducts are generally formed in good to high yields and diastereoselectivities and can be readily transformed into useful derivatives.

Transferable, easy-to-use and room-temperature-storable PCR mixes for microfluidic molecular diagnostics.

As the outbreak of coronavirus disease 2019 (COVID-19), on-site molecular diagnosis is becoming increasingly important. In this study, a freeze-drying method was introduced for PCR reagents to meet the requirements of microfluidic molecular diagnosis. Using this method, PCR components were pre-mixed and freeze-dried as a bead, which could be transferred into microfluidic chips easily.

Accurate nucleic acid quantification in a single sample tube without the need for calibration.

Convenient and accurate nucleic acid quantification (NAQ) is crucial to clinical diagnosis, forensic medicine, veterinary medicine and food analysis. However, traditional NAQ relies on the preparation of a laborious, time-consuming and expensive calibration curve, which would also propagate pipette errors through serially dilutions. Besides, traditional NAQ is run in different tubes, which introduces bias from random tube-to-tube variations and is unable to detect inhibitors from biological samples.

[Application of paper-based microfluidics in point-of-care testing].

Point-of-care testing (POCT) is a test method performed on the sampling site or patient bedside. Accurate results can be achieved rapidly by the application of portable analytical instruments and compatible reagents. It has been widely used in the field of in vitro diagnosis (IVD).

Room-temperature-storable PCR mixes for SARS-CoV-2 detection.

Objectives: A novel coronavirus (severe acute respiratory syndrome coronavirus 2, SARS-CoV-2) emerged in late 2019, causing an outbreak of pneumonia [coronavirus disease 2019 (COVID-19)] globally. Although the use of ready-made reaction mixes can enable more rapid PCR-based diagnosis of COVID-19, the need to transport and store these mixes at low temperatures presents challenges to already overburdened logistics networks.

Methods: Here, we present an optimized freeze-drying procedure that allows SARS-CoV-2 PCR mixes to be transported and stored at ambient temperatures, without loss of activity.

A point of care platform based on microfluidic chip for nucleic acid extraction in less than 1 minute.

In view of the complex procedure of nucleic acid extraction, there exists a huge challenge for the widespread use of point-of-care diagnostics for nucleic acid testing. To achieve point-of-care applications in a more rapid and cost-efficient manner, we designed a snake pipe-shaped microfluidic chip so as to accomplish reagents-prestored, time-saving, operation-simple nucleic acid extraction. All reagents needed for this process, including lysis buffer, wash buffer, elution buffer, and so on, were preloaded in the snake pipe and securely isolated by membrane valves, without the need for using any specialized equipment.

Total Synthesis of (-)-Ambiguine P.

Described is a concise total synthesis of (-)-ambiguine P, a cycloheptane-containing member of the hapalindole alkaloids. The challenging pentacyclic framework of the natural product was assembled rapidly via a [4 + 3] cycloaddition reaction-inspired strategy, and the tertiary hydroxy group was introduced by an NBS-mediated bromination-nucleophilic substitution sequence.

Total Synthesis of (-)-N-Methylwelwitindolinone B Isothiocyanate.

The asymmetric synthesis of (-)-N-methylwelwitindolinone B isothiocyanate is reported. Critical challenges overcome through these studies include the stereoselective installation of the sterically congested C13 alkyl chloride and control of the wayward reactivity of the indole unit to standard oxidants. A Pt-catalyzed hydrosilylation helped stymie unwanted rearrangements facilitated by vinyl group participation during the chloride installation step, and a new Fe -catalyzed oxidation accomplished the problematic conversion of indole into 2-indolinone.