Can venture capital shareholding improve M&A performance? An empirical study based on Chinese GEM-listed companies.

Existing studies have explored the impact of venture capital shareholding on the GEM-listed companies before and after listing from multiple perspectives. However, there has been limited research on the influence of venture capital shareholding on these companies' mergers and acquisitions(M&A) activities and performance. Additionally, two conflicting research findings have been presented in limited relevant studies.

Spectrum-effect relationship between HPLC fingerprints and antioxidant activity of Qi-Fu-Yin based on multiple statistical correlation analysis.

Introduction: Qi-Fu-Yin has been used to treat Alzheimer's disease (AD) in China. Oxidative stress has been recognized as a factor in AD progress. To date, there is no quality control method to ensure batch-to-batch consistency of Qi-Fu-Yin, and the potential antioxidant compounds in Qi-Fu-Yin remain uncertain.

A Facile and Green Approach for the Preparation of Amine-Functionalized Poly(ethylene glycol) by Reducing Poly(ethylene glycol) Azide with Dithiothreitol.

A facile and green approach for the preparation of PEG-NHs from PEG-Ns in water with DTT as the reduction reagent has been developed, avoiding the introduction of metal ions and difficulties in purification compared to the traditional synthesis process of PEG-NHs. A series of high-purity linear and multiarm PEG-NHs with different molecular weights were synthesized, demonstrating the versatility of this method. Additionally, HS-PEG-NH with high fidelity of thiol and amine was easily prepared through the one-step two functional group conversion of N-PEG-S-S-PEG-N, and the PEG-based NH-PEG@AuNPs were also prepared.

Iterative Synthesis of Stereo- and Sequence-Defined Polymers via Acid-Orthogonal Deprotection Chemistry.

Absolute control over polymer stereo- and sequence structure is highly challenging in polymer chemistry. Here, an acid-orthogonal deprotection strategy is proposed for the iterative synthesis of a family of unimolecular polymers starting with enantiopure serines, featuring precise sequence, stereoconfiguration and side-chain functionalities that cannot be achieved using traditional polymerization techniques. Acid-orthogonal deprotections proceed independently of one another by the selection of protecting groups that feature the respective acid-lability.

S-Carboxyanhydrides: Ultrafast and Selective Ring-Opening Polymerizations Towards Well-defined Functionalized Polythioesters.

Aliphatic polythioesters are popular polymers because of their appealing performance such as metal coordination ability, high refractive indices, and biodegradability. One of the most powerful approaches for generating these polymers is the ring-opening polymerization (ROP) of cyclic monomers. However, the synthesis of precisely controlled polythioesters via ROP of thiolactones still faces formidable challenges, including the minimal functional diversity of available thiolactone monomers, as well as inevitable transthioesterification side reactions.

A versatile strategy for the synthesis of sequence-defined peptoids with side-chain and backbone diversity amino acid building blocks.

Designing artificial macromolecules with absolute sequence order is still a long-term challenge in polymer chemistry as opposed to natural biopolymers with perfectly defined sequences like proteins and DNA. Herein, we combined amino acid building blocks and iterative Ugi reactions for the design and synthesis of sequence-defined peptoids. The highly efficient strategy provided excellent yields and enables multigram-scale synthesis of perfectly defined peptoids.

Synthesis of Y-Shaped OEGylated Poly(amino acid)s: The Impact of OEG Architecture.

OEGylation is an attractive approach to modifying poly(amino acid)s. OEG conjugation improves water-solubility of poly(amino acid)s, and confers possible thermal-responsive functionality for the conjugated poly(amino acid)s. Nevertheless, the impact of OEG architecture and the manner in which the OEG moiety interferes with the performances of poly(amino acid)s remain a work in progress.

Synthesis and Properties of Alternating Polypeptoids and Polyampholytes as Protein-Resistant Polymers.

Alternating polypeptoids are particularly appealing because alternating sequence may impart highly ordered structure and special functions, while their simple synthesis still remains a key challenge. We describe that natural amino acid monomers can be polymerized via Ugi reaction in a step-growth fashion as an AA' BB' system, which leads to alternating polypeptoids with molecular weight up to 15 kg/mol. These alternating polypeptoids are thermally responsive and exhibit cloud points ( T) between 27 and 37 °C.

Ugi Reaction of Natural Amino Acids: A General Route toward Facile Synthesis of Polypeptoids for Bioapplications.

Polypeptoids represent a significant class of synthetic analogues of natural polypeptides with potential biomimetic applications in materials, catalysis, and pharmaceuticals, but their simple and general synthesis still remains a key challenge. Herein, we demonstrate that Ugi reaction of natural amino acids leads to structurally diverse polypeptoids, including γ- and δ-, as well as poly(ε-peptoid)s, under mild conditions (open to air, room temperature, and catalyst free). Moreover, this strategy also offers manifold opportunities to introduce functional groups such as fluorescent and clickable alkenes groups into polypeptoids.

New chemosynthetic route to linear ε-poly-lysine.

ε-Poly-lysine (ε-PL) is an uncommon cationic, naturally-occurring homopolymer produced by the fermentation process. Due to its significant antimicrobial activity and nontoxicity to humans, ε-PL is now industrially produced as an additive, for food and cosmetics. However, the biosynthetic route can only make polymers with a molecular weight of about 3 kDa.

Formal [3+3] cycloaddition of indol-2-yl carbinol with azadiene and the oxidative ring expansion reaction for the synthesis of indole azepinones.

We present the unprecedented reaction of a [3+3] cyclization of indol-2-yl carbinol with azadiene for the construction of a six-membered ring and the subsequent oxidative ring expansion reaction for the construction of indole azepinones.