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1.
ACS Appl Mater Interfaces ; 16(15): 19003-19013, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38566322

RESUMO

The development of heterogeneous chiral dirhodium catalysts for fabricating important bioactive substances and reducing the loss of noble metals has long been of significant interest. However, there still remains formidable synthetic challenges since it requires multiple steps of the synthetic process, and rhodium is easily leached from solid materials during the reaction. Here, we demonstrated a self-supported strategy based on the Suzuki-Miyaura coupling reaction to construct two chiral dirhodium organic frameworks for heterogeneous asymmetric catalysis. The synthetic approach is simple and efficient since it requires only a small number of preparation steps and does not require any catalyst supporting materials. The obtained chiral dirhodium materials can be highly efficient and recyclable heterogeneous catalysts for asymmetric cyclopropanation between diazooxindole and alkenes. Importantly, Rh2-MOCP-2 exhibited almost similar catalytic performance compared to homogeneous catalyst Rh2(S-Br-NTTL)4. The afforded catalytic performance (93.9% yield with 80.9% ee) highly surpasses previous heterogeneous dirhodium catalysts reported to date.

2.
Angew Chem Int Ed Engl ; 63(7): e202318850, 2024 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-38169147

RESUMO

Due to the demanding depolymerization conditions and limited catalytic efficiency, enhancing lignin valorization remains challenging. Therefore, lowering the bond dissociation energy (BDE) has emerged as a viable strategy for achieving mild yet highly effective cleavage of bonds. In this study, a photocatalytic semi-hydrogenation/reduction strategy utilizing CsPbBr3 quantum dots (CPB-QDs) and Hantzsch ester (HEH2 ) as a synergistic catalytic system was introduced to reduce the BDE of Cß -O-Ar, achieving effective cleavage of the Cß -O-Ar bond. This strategy offers a wide substrate scope encompassing various ß-O-4 model lignin dimers, preoxidized ß-O-4 polymers, and native oxidized lignin, resulting in the production of corresponding ketones and phenols. Notably, this approach attained a turnover frequency (TOF) that is 17 times higher than that of the reported Ir-catalytic system in the photocatalytic depolymerization of the lignin model dimers. It has been observed via meticulous experimentation that HEH2 can be activated by CPB-QDs via single electron transfer (SET), generating HEH2 ⋅+ as a hydrogen donor while also serving as a hole quencher. Moreover, HEH2 ⋅+ readily forms an active transition state with the substrates via hydrogen bonding. Subsequently, the proton-coupled electron transfer (PCET) from HEH2 ⋅+ to the carbonyl group of the substrate generates a Cα ⋅ intermediate.

3.
Life (Basel) ; 13(10)2023 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-37895372

RESUMO

BACKGROUND: Post-hepatectomy liver failure (PHLF) remains a complication with the potential risk of mortality for hepatocellular carcinoma (HCC) patients. The systemic inflammatory response (SIR) has been demonstrated to be associated with a bad prognosis of liver cirrhosis and tumors. This study aims to evaluate the incremental prognostic value of inflammatory markers in predicting PHLF in patients with HCC. METHODS: Clinical characteristics and variables were retrospectively collected in 2824 patients diagnosed with HCC who underwent radical hepatectomy from the First Medical Center of the General Hospital of the People's Liberation Army. A recently published prognostic model for PHLF was used as the reference model. The increase in AUC (ΔAUC), integrated discrimination improvement (IDI), and the continuous version of the net reclassification improvement (NRI) were applied for quantifying the incremental value of adding the inflammatory markers to the reference model. A p value < 0.05 was considered statistically significant. RESULTS: The reference PHLF model showed acceptable prediction performance in the current cohort, with an AUC of 0.7492 (95%CI, 0.7191-0.7794). The calculated ΔAUC associated with procalcitonin (PCT) was the only one that was statistically significant (p < 0.05), with a value of 0.0044, and demonstrated the largest magnitude of the increase in AUC. The continuous NRI value associated with the systemic immune-inflammation index (SII) was 35.79%, second only to GPS (46.07%). However, the inflammatory markers of the new models with statistically significant IDI only included WBC count, lymphocyte count, and SII. IDI associated with SII, meanwhile, was the maximum (0.0076), which was consistent with the performance of using the ΔAUC (0.0044) to assess the incremental value of each inflammatory variable. CONCLUSIONS: Among a wide range of inflammatory markers, only PCT and SII have potential incremental prognostic value for predicting PHLF in patients with radical resectable HCC.

4.
Artigo em Inglês | MEDLINE | ID: mdl-36350487

RESUMO

PURPOSE: Doxorubicin is an important cancer chemotherapeutic agent with severe cardiotoxic effects that eventually lead to dilated cardiomyopathy (DCM). Calsyntenin-1(CLSTN1) plays a critical role in the nervous system, but its relevance in cardiovascular diseases is unknown. We investigated the significance of CLSTN1 in doxorubicin-induced DCM. METHODS: CLSTN1 expression in doxorubicin-induced DCM rats and H9c2 cells was determined using western blotting. To further explore the functions of CLSTN1, a cardiac-specific CLSTN1 overexpression rat model was constructed. The rats were subjected to analysis using echocardiographic, hemodynamic, and electrocardiographic parameters. Potential downstream molecules in CLSTN1 overexpression heart tissue were investigated using proteomics and western blotting. Finally, a knockdown of CLSTN1 was constructed to investigate the rescue function on doxorubicin-induced cell toxicity. RESULTS: CLSTN1 protein expression increased drastically in doxorubicin-induced DCM rats and H9c2 cells. Under doxorubicin treatment, CLSTN1 protein-specific overexpression in the heart muscle promoted cardiac chamber enlargement and heart failure, while the knockdown of CLSTN1 reduced doxorubicin-induced cardiomyocyte toxicity in vitro. At the mechanistic level, overexpression of CLSTN1 downregulated SERCA2 expression and increased the phosphorylation levels of PI3K-Akt and CaMK2. CONCLUSION: Our findings demonstrated that CLSTN1 promotes the pathogenesis of doxorubicin-induced DCM. CLSTN1 could be a therapeutic target to prevent the development of doxorubicin-induced DCM.

5.
Front Cardiovasc Med ; 9: 945451, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36267636

RESUMO

Background: Coronary artery disease (CAD) is a progressive disease of the blood vessels supplying the heart, which leads to coronary artery stenosis or obstruction and is life-threatening. Early diagnosis of CAD is essential for timely intervention. Imaging tests are widely used in diagnosing CAD, and artificial intelligence (AI) technology is used to shed light on the development of new imaging diagnostic markers. Objective: We aim to investigate and summarize how AI algorithms are used in the development of diagnostic models of CAD with imaging markers. Methods: This scoping review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guideline. Eligible articles were searched in PubMed and Embase. Based on the predefined included criteria, articles on coronary heart disease were selected for this scoping review. Data extraction was independently conducted by two reviewers, and a narrative synthesis approach was used in the analysis. Results: A total of 46 articles were included in the scoping review. The most common types of imaging methods complemented by AI included single-photon emission computed tomography (15/46, 32.6%) and coronary computed tomography angiography (15/46, 32.6%). Deep learning (DL) (41/46, 89.2%) algorithms were used more often than machine learning algorithms (5/46, 10.8%). The models yielded good model performance in terms of accuracy, sensitivity, specificity, and AUC. However, most of the primary studies used a relatively small sample (n < 500) in model development, and only few studies (4/46, 8.7%) carried out external validation of the AI model. Conclusion: As non-invasive diagnostic methods, imaging markers integrated with AI have exhibited considerable potential in the diagnosis of CAD. External validation of model performance and evaluation of clinical use aid in the confirmation of the added value of markers in practice. Systematic review registration: [https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022306638], identifier [CRD42022306638].

6.
ACS Org Inorg Au ; 2(4): 351-358, 2022 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-36855591

RESUMO

Here, we report a one-pot Stadler-Ziegler reaction toward the synthesis of 1-thioglycosides in good yield from commercially available anilines and (un)protected 1-glycosyl thiols. This simple and mild approach employs the photoredox catalyst [Ru(bpy)3](PF6)2 under visible light.

7.
Org Lett ; 22(16): 6584-6589, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32806176

RESUMO

A general protocol for functionalization of an anomeric selonate anion at room temperature has been reported. By using the PdG3 XantPhos catalyst, the cross-coupling between the in situ-generated glycosyl selenolate and a broad range of (hetero)aryl and alkenyl iodides furnished a series of functionalized selenoglycosides in excellent yields with perfect control of the anomeric configuration.

8.
Chem Commun (Camb) ; 56(32): 4464-4467, 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-32196023

RESUMO

Here we report a simple route towards the synthesis of thioglycosides, in which electrochemical cross-coupling is used to form a S-C glycosidic bond from protected and unprotected thiosugars with functionalized aryl bromides under base free conditions. The reaction manifold that we report here demonstrates the power of electrochemistry to access highly complex glycosides under mild conditions.

9.
Org Lett ; 22(1): 57-61, 2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-31860311

RESUMO

An efficient and selective C-H activation method of readily available ß-N-aryl glycosides with various alkynes has been established. Using [Cp*RhCl2]2 as a catalyst and AgSbF6 in DCE, this protocol proved to be general to prepare a variety of 2,3-substituted N-glycosyl indoles in good yields.

10.
Org Lett ; 21(13): 5132-5137, 2019 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-31247796

RESUMO

A general protocol for functionalization of glycosyl thiols has been reported. This protocol is based on a single-electron Ni/photoredox dual-catalyzed cross coupling between 1-thiosugars and a broad range of aryl bromides and iodides as well as alkenyl and alkynyl halides. This base-free method gives access to a series of functionalized thioglycosides in moderate to excellent yields with a perfect control of the anomeric configuration. Moreover, it has been shown that this methodology may be transposed successfully to the continuous-flow photoredox chemistry.

11.
Org Biomol Chem ; 16(11): 1807-1811, 2018 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-29465725

RESUMO

The first O-difluorodeuteromethylation of phenols using commercial diethyl bromodifluoromethylphosphonate and deuterium oxide to prepare various difluorodeuteromethyl aryl ethers is reported. This facile method affords a convenient way to introduce OCF2D groups into organic molecules.

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