Amide-Directed, Rhodium-Catalyzed Regio- and Enantioselective Hydroacylation of Internal Alkenes with Unfunctionalized Aldehydes.

Despite the current progress achieved in asymmetric hydroacylations, highly enantioselective catalytic addition of unfunctionalized aldehydes to internal alkenes remains an unsolved challenge. Here, using a coordination-assisted strategy, we developed a rhodium-catalyzed regio- and enantioselective addition of unfunctionalized aldehydes to internal alkenes such as enamides and ß,γ-unsaturated amides. Valuable α-amino ketones and 1,4-dicarbonyl compounds were directly obtained with high enantioselectivity from readily available materials.

One-Step Electrochemical Ethylene-to-Ethylene Glycol Conversion over a Multitasking Molecular Catalyst.

Ethylene glycol is an essential commodity chemical with high demand, which is conventionally produced via thermocatalytic oxidation of ethylene with huge fossil fuel consumption and CO2 emission. The one-step electrochemical approach offers a sustainable route but suffers from reliance on noble metal catalysts, low activity, and mediocre selectivity. Herein, we report a one-step electrochemical oxidation of ethylene to ethylene glycol over an earth-abundant metal-based molecular catalyst, a cobalt phthalocyanine supported on a carbon nanotube (CoPc/CNT). The catalyst delivers ethylene glycol with 100% selectivity and 1.78 min-1 turnover frequency at room temperature and ambient pressure, more competitive than those obtained over palladium catalysts. Experimental data demonstrate that the catalyst orchestrates multiple tasks in sequence, involving electrochemical water activation to generate high-valence Co-oxo species, ethylene epoxidation to afford an ethylene oxide intermediate via oxygen transfer, and eventually ring-opening of ethylene oxide to ethylene glycol facilitated by in situ formed Lewis acid site. This work offers a great opportunity for commodity chemicals synthesis based on a one-step, earth-abundant metal-catalyzed, and renewable electricity-driven route.

Rhodium-Catalyzed Highly Enantioselective Hydroboration of Acyclic Tetrasubstituted Alkenes Directed by an Amide.

Although progress has been made in enantioselective hydroboration of di- and trisubstituted alkenes over the past decades, enantioselective hydroboration of tetrasubstituted alkenes with high diastereo- and enantioselectivities continues as an unmet challenge since the 1950s due to its extremely low reactivity and the difficulties to simultaneously control the regio- and stereoselectivity of a tetrasubstituted alkene. Here, we report highly regio-, diastereo-, and enantioselective catalytic hydroboration of diverse acyclic tetrasubstituted alkenes. The delicate interplay of an electron-rich rhodium complex and coordination-assistance forms a highly adaptive catalyst that effectively overcomes the low reactivity and controls the stereoselectivity. The generality of the catalyst system is exemplified by its efficacy across various tetrasubstituted alkenes with diverse steric and electronic properties.

Visible-Light-Driven Germyl Radical Generation via EDA-Catalyzed ET-HAT Process.

We have established a facile and efficient protocol for the generation of germyl radicals by employing photo-excited electron transfer (ET) in an electron donor-acceptor (EDA) complex to drive hydrogen-atom transfer (HAT) from germyl hydride (R3GeH). Using a catalytic amount of EDA complex of commercially available thiol and benzophenone derivatives, the ET-HAT cycle smoothly proceeds simply upon blue-light irradiation without any transition metal or photocatalyst. This protocol also affords silyl radical from silyl hydride.

Reasons for Silicone Breast Implant Removal After Long-Term Implantation in Chinese Patients Without Complications: A Questionnaire-Based Study.

BACKGROUND: There are few studies of Chinese patients who request silicone breast implant removal after at least 10 years of implantation without any complications. This study aimed to study the characteristics of these patients, explore their reasons for breast implant removal and associate factors that affect their choice, so as to provide valuable information on clinical decision making. METHODS: A total of 55 eligible female patients (110 breasts) were enrolled from 2016 to 2022. A preoperative questionnaire survey before removal surgery and a telephone follow-up 1 year after removal surgery were conducted to collect data. RESULTS: The mean age of the patients was 40.6±8.8 years with the average time from breast augmentation to implant removal or replacement ranged from 10 to 15 years. Concerns about the aging of silicone gel-filled breast implant and the adverse effects of its long-term placement on body health were the top two reasons for breast implant removal. 63% of patients refused implant replacement, who were nearly 10 years older than those accepted implant replacement (p<0.05). Older age at implant removal (OR=0.67; 95%CI: 0.44-0.89) and a history of basic diseases (OR=0.02; 95%CI: 0.00-0.39) were statistically associated with lower rate of implant replacement. CONCLUSIONS: Concerns about the aging of silicone gel-filled breast implant were the main reason for uncomplicated patients to remove their breast implants. A comprehensive analysis based on patient's subjective choice and physical condition was suggested when an uncomplicated patient asks for implant removal. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Chin Augmentation and Treatment of Chin Retrusion with a Flexible Hyaluronic Acid Filler in Asian Subjects: A Randomized, Controlled, Evaluator-Blinded Study.

BACKGROUND: Aesthetic improvement of the chin is increasingly requested by patients, including those of Chinese origin. METHODS: A randomized, evaluator-blinded, no-treatment controlled study evaluated the effectiveness and safety of a flexible hyaluronic acid (HA) filler, Restylane® DefyneTM (HADEF), in the correction of chin retrusion in a Chinese adult population over 12 months after treatment. On Day 1, subjects were randomized 3:1 into two groups, HADEF or delayed-treatment controls, and those in the HADEF group were administered treatment. An optional touch-up treatment was administered 1 month after treatment to obtain optimal chin augmentation. The initially untreated control group was offered delayed-treatment after 6 months (including 1-month touch-up). RESULTS: HADEF was superior to no-treatment in improving chin retrusion according to the blinded evaluator at 6 months [Galderma Chin Retrusion Scale (GCRS) responder rate (≥ 1-point improvement from baseline) of 81% vs. 5% for untreated controls; p < 0.001, meeting the primary effectiveness objective. A majority of subjects maintained improvement at 12 months (61% in the HADEF group). All subjects reported satisfaction with results at 6 months after treatment with HADEF and aesthetic improvement rates per the global aesthetic improvement scale (GAIS) were high for 12 months following treatment, with an acceptable safety profile. CONCLUSIONS: These results demonstrated HADEF to be effective and safe for the correction of mild-to-moderate chin retrusion in Chinese subjects, confirming findings previously observed in a western population. LEVEL OF EVIDENCE I: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Application of magnetic resonance imaging with intraoperative color Doppler ultrasound in the treatment of patients with polyacrylamide hydrogel injected for breast augmentation: a retrospective study of 204 cases for 12 years.

Purpose: Polyacrylamide hydrogel (PAHG), which had been used widely for breast augmentation, has been banned for more than 15 years. Patients who had been injected PAHG for breast augmentation need evacuation surgery to remove as much as possible. To provide a series of diagnosis and treatment process MRI and intraoperative color Doppler ultrasound are combined for maximal removal of PAHG. Methods: The patients who received evacuation surgery in Peking University Third Hospital from 2010 to 2022 after PAHG injection for breast augmentation were included in this research. MR scanning was performed preoperatively and postoperatively in some of these patients and color Doppler ultrasound was applied to help evacuate PAHG intraoperatively. The mean clearance rate of PAHG was calculated according to the MRI outcomes. Results: Two hundred and 4 patients had received evacuation surgery after PAHG injection for breast augmentation with an average age of 42.8 years and an average body mass index of 21.2 kg/m2. The average PAHG retention time was 13.5 years. Among them, 52 patients underwent pre- and postoperative MRI scanning. The mean three-dimensional (3D) volume of PAHG was 684.8 mL (range, 350.0-1,123.9 mL), and the average residual 3D volume of PAHG was 53.7 mL (range, 12.4-98.3 mL). The mean clearance rate was 92.1%. Conclusion: MRI and intraoperative color Doppler ultrasound can provide effective and precise location information of PAHG for evacuation surgery, which is a reliable method to ensure the maximal removal of PAHG.

Theoretical Insights into N-Glycoside Bond Cleavage of 5-Carboxycytosine by Thymine DNA Glycosylase: A QM/MM Study.

Thymine DNA glycosylase (TDG)-mediated excision of 5-formylcytosine and 5-carboxylcytosine (5-caC) is a critical step in active DNA demethylation. Herein, we employed a combined quantum mechanics/molecular mechanics approach to investigate the reaction mechanism of TDG-catalyzed N-glycosidic bond cleavage of 5-caC. The calculated results show that TDG-catalyzed 5-caC excision follows a concerted (SN2) mechanism in which glycosidic bond dissociation is coupled with nucleophile attack. Protonation of the 5-caC anion contributes to the cleavage of the N-glycoside bond, in which the N3-protonated zwitterion and imino tautomers are more favorable than carboxyl-protonated amino tautomers. This is consistent with the experimental data. Furthermore, our results reveal that the configuration rearrangement process of the protonated 5-caC would lower the stability of the N-glycoside bond and substantially reduce the barrier height for the subsequent C1'-N1 bond cleavage. This should be attributed to the smaller electrostatic repulsion between the leaving base and the negative phosphate group as a result of the structural rearrangement.

Effect of an Airbag-selective Portal Vein Blood Arrester on the Liver after Hepatectomy: A New Technique for Selective Clamping of the Portal Vein.

OBJECTIVE: A novel technique was explored using an airbag-selective portal vein blood arrester that circumvents the need for an intraoperative assessment of anatomical variations in patients with complex intrahepatic space-occupying lesions. METHODS: Rabbits undergoing hepatectomy were randomly assigned to 4 groups: intermittent portal triad clamping (PTC), intermittent portal vein clamping (PVC), intermittent portal vein blocker with an airbag-selective portal vein blood arrester (APC), and without portal blood occlusion (control). Hepatic ischemia and reperfusion injury were assessed by measuring the 7-day survival rate, blood loss, liver function, hepatic pathology, hepatic inflammatory cytokine infiltration, hepatic malondialdehyde levels, and proliferating cell nuclear antigen levels. RESULTS: Liver damage was substantially reduced in the APC and PVC groups. The APC animals exhibited transaminase levels similar to or less oxidative stress damage and inflammatory hepatocellular injury compared to those exhibited by the PVC animals. Bleeding was significantly higher in the control group than in the other groups. The APC group had less bleeding than the PVC group because of the avoidance of portal vein skeletonization during hepatectomy. Thus, more operative time was saved in the APC group than in the PVC group. Moreover, the total 7-day survival rate in the APC group was higher than that in the PTC group. CONCLUSION: Airbag-selective portal vein blood arresters may help protect against hepatic ischemia and reperfusion injury in rabbits undergoing partial hepatectomy. This technique may also help prevent liver damage in patients requiring hepatectomy.

Historical context, process, and development trends of pediatric thyroid cancer research: a bibliometric analysis.

Objective: At present, the structure of knowledge in the field of childhood thyroid cancer is not clear enough, and scholars lack a sufficient understanding of the developing trends in this field, which has led to a shortage of forward-looking outputs. The purpose of this research is to help scholars construct a complete knowledge framework and identify current challenges, opportunities, and development trends. Methods: We searched the literature in the Web of Science Core Collection database on August 7, 2023 and extracted key information from the top 100 most cited articles, such as the countries, institutions, authors, themes, and keywords. We used bibliometric tools such as bibliometrix, VOSviewer, and CiteSpace for a visualization analysis and Excel for statistical descriptions. Results: The top 100 most cited articles fluctuated over time, and the research was concentrated in European countries, the United States, and Japan, among which scientific research institutions and scholars from the United States made outstanding contributions. Keyword analysis revealed that research has shifted from simple treatment methods for pediatric thyroid cancer (total thyroidectomy) and inducing factors (the Chernobyl power station accident) to the clinical applications of genetic mutations (such as the BRAF and RET genes) and larger-scale genetic changes (mutation studies of the DICER1 gene). The thematic strategy analysis showed an increasing trend towards the popularity of fusion oncogenes, while the popularity of research on traditional treatments and diagnostics has gradually declined. Conclusion: Extensive research has been conducted on the basic problems of pediatric thyroid cancer, and there has been significant outputs in the follow-up and cohort analysis of conventional diagnostic and treatment methods. However, these methods still have certain limitations. Therefore, scholars should focus on exploring fusion genes, the clinical applications of molecular targets, and novel treatment methods. This study provides a strong reference for scholars in this field.

Circ_0012152 Accelerates Acute Myeloid Leukemia Progression through the miR-652-3p/SOX4 Axis.

OBJECTIVE: Acute myeloid leukemia (AML) is an aggressive hematological malignancy characterized by abnormal myeloid blast expansion. Recent studies have demonstrated that circular RNAs play a role in AML pathogenesis. In this study, we aimed to investigate the clinical significance of circ_0012152 in AML and elucidate its underlying molecular mechanism in the pathogenesis of this condition. METHODS: Circ_0012152 expression was detected by quantitative real-time polymerase chain reaction in samples obtained from 247 patients with AML and 40 healthy controls. A systematic analysis of clinical characteristics and prognostic factors was also conducted. Cell growth was assessed using the Cell Counting Kit-8 (CCK-8) assay, and apoptosis and cell cycle progression were evaluated by flow cytometry. Moreover, RNA pull-down was performed to identify target microRNAs, and transcriptome RNA sequencing and bioinformatics analyses were utilized to identify downstream mRNA targets. RESULTS: Circ_0012152 was significantly upregulated in samples from patients with AML and served as an independent adverse prognostic factor for overall survival (OS) (hazard ratio: 2.357; 95% confidence interval 1.258-4.415). The circ_0012152 knockdown reduced cell growth, increased apoptosis, and inhibited cell cycle progression in AML cell lines. RNA pull-down and sequencing identified miR-652-3p as a target microRNA of circ_0012152. Cell growth inhibition by circ_0012152 knockdown was significantly relieved by miR-652-3p inhibitors. We suggested that miR-652-3p targeted SOX4, as the decrease in SOX4 expression resulting from circ_0012152 knockdown was upregulated by miR-652-3p inhibitors in AML cells. CONCLUSION: Circ_0012152 is an independent poor prognostic factor for OS in AML, and it promotes AML cell growth by upregulating SOX4 through miR-652-3p.

Multiomics of parkinsonism cynomolgus monkeys highlights significance of metabolites in interaction between host and microbiota.

The gut microbiota has been demonstrated to play a significant role in the pathogenesis of Parkinson's disease (PD). However, conflicting findings regarding specific microbial species have been reported, possibly due to confounding factors within human populations. Herein, our current study investigated the interaction between the gut microbiota and host in a non-human primate (NHP) PD model induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) using a multi-omic approach and a self-controlled design. Our transcriptomic sequencing of peripheral blood leukocytes (PBL) identified key genes involved in pro-inflammatory cytokine dysregulation, mitochondrial function regulation, neuroprotection activation, and neurogenesis associated with PD, such as IL1B, ATP1A3, and SLC5A3. The metabolomic profiles in serum and feces consistently exhibited significant alterations, particularly those closely associated with inflammation, mitochondrial dysfunctions and neurodegeneration in PD, such as TUDCA, ethylmalonic acid, and L-homophenylalanine. Furthermore, fecal metagenome analysis revealed gut dysbiosis associated with PD, characterized by a significant decrease in alpha diversity and altered commensals, particularly species such as Streptococcus, Butyrivibrio, and Clostridium. Additionally, significant correlations were observed between PD-associated microbes and metabolites, such as sphingomyelin and phospholipids. Importantly, PDPC significantly reduced in both PD monkey feces and serum, exhibiting strong correlation with PD-associated genes and microbes, such as SLC5A3 and Butyrivibrio species. Moreover, such multi-omic differential biomarkers were linked to the clinical rating scales of PD monkeys. Our findings provided novel insights into understanding the potential role of key metabolites in the host-microbiota interaction involved in PD pathogenesis.

Human-like adrenal features in Chinese tree shrews revealed by multi-omics analysis of adrenal cell populations and steroid synthesis.

The Chinese tree shrew ( Tupaia belangeri chinensis) has emerged as a promising model for investigating adrenal steroid synthesis, but it is unclear whether the same cells produce steroid hormones and whether their production is regulated in the same way as in humans. Here, we comprehensively mapped the cell types and pathways of steroid metabolism in the adrenal gland of Chinese tree shrews using single-cell RNA sequencing, spatial transcriptome analysis, mass spectrometry, and immunohistochemistry. We compared the transcriptomes of various adrenal cell types across tree shrews, humans, macaques, and mice. Results showed that tree shrew adrenal glands expressed many of the same key enzymes for steroid synthesis as humans, including CYP11B2, CYP11B1, CYB5A, and CHGA. Biochemical analysis confirmed the production of aldosterone, cortisol, and dehydroepiandrosterone but not dehydroepiandrosterone sulfate in the tree shrew adrenal glands. Furthermore, genes in adrenal cell types in tree shrews were correlated with genetic risk factors for polycystic ovary syndrome, primary aldosteronism, hypertension, and related disorders in humans based on genome-wide association studies. Overall, this study suggests that the adrenal glands of Chinese tree shrews may consist of closely related cell populations with functional similarity to those of the human adrenal gland. Our comprehensive results (publicly available at http://gxmujyzmolab.cn:16245/scAGMap/) should facilitate the advancement of this animal model for the investigation of adrenal gland disorders.