Synergistic Copper-Aminocatalysis for Direct Tertiary α-Alkylation of Ketones with Electron-Deficient Alkanes.

In this study, a novel approach for the tertiary α-alkylation of ketones using alkanes with electron-deficient C─H bonds is presented, employing a synergistic catalytic system combining inexpensive copper salts with aminocatalysis. This methodology addresses the limitations of traditional alkylation methods, such as the need for strong metallic bases, regioselectivity issues, and the risk of over alkylation, by providing a high reactivity and chemoselectivity without the necessity for pre-functionalized substrates. The dual catalytic strategy enables the direct functionalization of C(sp3)─H bonds, demonstrating remarkable selectivity in the presence of conventional C(sp3)─H bonds that are adjacent to heteroatoms or π systems, which are typically susceptible to single-electron transfer processes. The findings contribute to the advancement of alkylation techniques, offering a practical and efficient route for the construction of C(sp3)─C(sp3) bonds, and paving the way for further developments in the synthesis of complex organic molecules.

Safety of nighttime elective hepatectomy for hepatocellular carcinoma patients: a retrospective study.

Purpose: This study aimed to investigate whether nighttime elective surgery influenced the short-term outcomes and prognosis of hepatocellular carcinoma (HCC) patients. Methods: The 1,339 HCC patients who underwent hepatectomy were divided into the daytime surgery group (8 a.m.-6 p.m., n = 1,105) and the nighttime surgery group (after 6 p.m., n = 234) based on the start time of surgery. The 1:2 propensity score matching (PSM) analysis was used to control confounding factors. The short-term outcomes of HCC patients in the 2 groups were compared before and after PSM. Factors associated with major complications (Clavien-Dindo grade, ≥III) and textbook oncologic outcomes (TOO) were separately identified by multivariable logistic regression based on variables screened via least absolute shrinkage and selection operator (LASSO). The Kaplan-Meier method was used to analyze overall survival (OS) and recurrence-free survival (RFS). Results: TOO was achieved after surgery in 897 HCC patients. HCC patients in the nighttime surgery group had a higher body mass index (P = 0.010). After 1:2 PSM, the baseline characteristics of patients between the 2 groups were similar. Short-term outcomes in HCC patients were comparable both before and after PSM (all Ps > 0.05), as were TOO in the 2 groups before (P = 0.673) and after PSM (P = 0.333). In our LASSO-logistic regression, nighttime surgery was not an independent factor associated with major complications or TOO. Both groups also had similar OS (P = 0.950) and RFS (P = 0.740) after PSM. Conclusion: Our study revealed the safety of nighttime elective hepatectomy for HCC patients.

PIVKA-II combined with tumor burden score to predict long-term outcomes of AFP-negative hepatocellular carcinoma patients after liver resection.

BACKGROUND: This study aimed to establish a simple prognostic scoring model based on tumor burden score (TBS) and PIVKA-II to predict long-term outcomes of α-fetoprotein (AFP)-negative hepatocellular carcinoma (HCC) patients. METHODS: 511 patients were divided into the training cohort (n = 305) and the validation cohort (n = 206) at a ratio of 6:4. Receiver operating characteristic curves (ROC) were established to identify cutoff values of TBS and PIVKA-II. Kaplan-Meier curves were used to analyze survival outcomes. The multivariable Cox regression was used to identify variables independently associated with survival outcomes. The predictive performance of the TBS-PIVKA II score (TPS) model was compared with Barcelona clinic liver cancer (BCLC) stage and American Joint Committee on Cancer (AJCC TNM) stage. RESULTS: The present study established the TPS model using a simple scoring system (0, 1 for low/high TBS [cutoff value: 4.1]; 0, 1 for low/high PIVKA-II [cutoff value: 239 mAU/mL]). The TPS scoring model was divided into three levels according to the summation of TBS score and PIVKA-II score: TPS 0, TPS 1, and TPS 2. The TPS scoring model was able to stratify OS (training: p < 0.001, validation: p < 0.001) and early recurrence (training: p < 0.001; validation: p = 0.001) in the training cohort and the validation cohort. The TPS score was independently associated with OS (TPS 1 vs. 0, HR: 2.28, 95% CI: 1.01-5.17; TPS 2 vs. 0, HR: 4.21, 95% CI: 2.01-8.84) and early recurrence (TPS 1 vs. 0, HR: 3.50, 95% CI: 1.71-7.16; TPS 2 vs. 0, HR: 3.79, 95% CI: 1.86-7.75) in the training cohort. The TPS scoring model outperformed BCLC stage and AJCC TNM stage in predicting OS and early recurrence in the training cohort and the validation cohort. But the TPS scoring model was unable to stratify the late recurrence in the training cohort (p = 0.872) and the validation cohort (p = 0.458). CONCLUSIONS: The TPS model outperformed the BCLC stage and AJCC TNM stage in predicting OS and early recurrence of AFP-negative HCC patients after liver resection, which might better assist surgeons in screening AFP-negative HCC patients who may benefit from liver resection.

Surface Modification of ZnO Nanocrystals with Conjugated Polyelectrolytes Carrying Different Counterions for Inverted Perovskite Light-Emitting Diodes.

In this work, bromide ions (Br-) on the conjugated polyelectrolytes (CPEs) were converted to tetrafluoroborate (BF4-) or hexafluorophosphate (PF6-) ions through anion exchange. The three CPEs (PFN-Br, PFN-BF4, and PFN-PF6) were utilized solely for surface modification of zinc oxide nanocrystals (ZnO NCs). The ionic groups on CPEs can form permanent dipoles to facilitate charge injection from ZnO NCs to cesium lead bromide (CsPbBr3) NC emitters, therefore promoting luminescent properties of inverted perovskite light-emitting diodes (PeLEDs). The experimental results reveal that ZnO NC films were smoothened by CPEs that allowed flat deposition of the perovskite active layers; moreover, the improved contact between ZnO and perovskite layers was beneficial for reducing leakage current, as verified in the dark current measurement of devices. In addition, the incorporation of CPEs helped to passivate the defects of ZnO NC films and prolong the carrier lifetime of CsPbBr3 NCs. PeLEDs based on different CPEs were then constructed and evaluated. The device based on PFN-Br showed the highest brightness and current efficiency, and the one based on PFN-BF4 exhibited better current efficiency over PFN-Br under the low current density below 160 mA/cm2. This is the first report using fluorene-based CPEs with Br-, BF4-, or PF6- groups to modify the properties of ZnO and CsPbBr3 NCs for the construction of inverted PeLEDs so far. Our experiments explored new kinds of CPEs on the surface modification of ZnO NCs and device performance of PeLEDs.

Preparation of Nickel Oxide Nanoflakes for Carrier Extraction and Transport in Perovskite Solar Cells.

Hole transport layers (HTLs) with high conductivity, charge extraction ability, and carrier transport capability are highly important for fabricating perovskite solar cells (PSCs) with high power conversion efficiency and device stability. Low interfacial recombination between the HTL and perovskite absorber is also crucial to the device performance of PSCs. In this work, we developed a three-stage method to prepare NiOx nanoflakes as the HTL in the inverted PSCs. Due to the addition of the nanoflake layer, the deposited perovskite films with larger grain sizes and fewer boundaries were obtained, implying higher photogenerated current and fill factors in our PSCs. Meanwhile, the downshifted valence band of the NiOx HTL improved hole extraction from the perovskite absorber and open-circuit voltages of PSCs. The optimized device based on the NiOx nanoflakes showed the highest efficiency of 14.21% and a small hysteresis, which outperformed the NiOx thin film as the HTL. Furthermore, the device maintained 83% of its initial efficiency after 60 days of storage. Our results suggest that NiOx nanoflakes provide great potential for constructing PSCs with high efficiency and long-term stability.

Efficient and stable perovskite solar cells using manganese-doped nickel oxide as the hole transport layer.

Organic/inorganic hybrid perovskite solar cells (PSCs) have represented a promising field of renewable energy in recent years due to the compelling advantages of high efficiency, facile fabrication process and low cost. The development of inorganic p-type metal oxide materials plays an important role in the performance and stability of PSCs for commercial purposes. Herein a facile and effective way to improve hole extraction and conductivity of NiO x films by manganese (Mn) doping is demonstrated in this study. A Mn-doped NiO x layer was prepared by the sol-gel process and served as the hole transport layer (HTL) in inverted PSCs. The results suggest that Mn-doped NiO x is helpful for the growth of perovskite layers with larger grains and higher crystallinity compared with the pristine NiO x . Furthermore, the perovskite films deposited on Mn-doped NiO x exhibit lower recombination and shorter carrier lifetime. The device based on 0.5 mol% Mn-doped NiO x as the HTL displayed the best power conversion efficiency (PCE) of 17.35% and a high fill factor (FF) of 81%, which were significantly higher than those of the one using the pristine NiO x HTL (PCE = 14.71%, FF = 73%). Moreover, the device retained 70% of its initial efficiency after 35 days' storage under a continuous halogen lamp matrix exposure with an illumination intensity of 1000 W m-2. Our results widen the development of PSCs for future production.

Inkjet-Printed High-Performance Flexible Micro-Supercapacitors with Porous Nanofiber-Like Electrode Structures.

Flexible planar micro-supercapacitors (MSCs) with unique loose and porous nanofiber-like electrode structures are fabricated by combining electrochemical deposition with inkjet printing. Benefiting from the resulting porous nanofiber-like structures, the areal capacitance of the inkjet-printed flexible planar MSCs is obviously enhanced to 46.6 mF cm-2 , which is among the highest values ever reported for MSCs. The complicated fabrication process is successfully averted as compared with previously reported best-performing planar MSCs. Besides excellent electrochemical performance, the resultant MSCs also show superior mechanical flexibility. The as-fabricated MSCs can be highly bent to 180° 1000 times with the capacitance retention still up to 86.8%. Intriguingly, because of the remarkable patterning capability of inkjet printing, various modular MSCs in serial and in parallel can be directly and facilely inkjet-printed without using external metal interconnects and tedious procedures. As a consequence, the electrochemical performance can be largely enhanced to better meet the demands of practical applications. Additionally, flexible serial MSCs with exquisite and aesthetic patterns are also inkjet-printed, showing great potential in fashionable wearable electronics. The results suggest a feasible strategy for the facile and cost-effective fabrication of high-performance flexible MSCs via inkjet printing.

Proteomic analysis of apoptosis induction by lariciresinol in human HepG2 cells.

Lariciresinol (LA) is a traditional Chinese medicine possessing anticancer activity, but its mechanism of action remains unclear. The present study explored the effects of LA on human HepG2 cells and the underlying mechanism. Our data indicated that LA inhibited cell proliferation and induced cell cycle arrest in S phase, subsequently resulting in apoptosis in HepG2 cells. Using a proteomics approach, eight differentially expressed proteins were identified. Among them, three proteins, glyceraldehyde-3-phosphate, UDP-glucose 4-epimerase, and annexin A1, were upregulated, while the other five proteins, heat shock protein 27, haptoglobin, tropomodulin-2, tubulin alpha-1A chain, and brain acid soluble protein 1, were downregulated; all of these proteins are involved in cell proliferation, metabolism, cytoskeletal organization, and movement. Network analysis of these proteins suggested that the ubiquitin-conjugating enzyme (UBC) plays an important role in the mechanism of LA. Western blotting confirmed downregulation of heat shock protein 27 and upregulation of ubiquitin and UBC expression levels in LA-treated cells, consistent with the results of two-dimensional electrophoresis and a STRING software-based analysis. Overall, LA is a multi-target compound with anti-cancer effects potentially related to the ubiquitin-proteasome pathway. This study will increase our understanding of the anticancer mechanisms of LA.