ABSTRACT
PURPOSE: There is currently no consensus on the optimal drilling direction of the fibular bone tunnel for anterior talofibular ligament (ATFL) reconstruction, and few studies have investigated the potential injury to the peroneus longus and brevis tendons and the possibility of fibular fractures during the drilling process. The aim of this study was to assess the potential risk of drilling the tunnel from different directions and determine the most appropriate tunnel direction. The hypothesis was that drilling the tunnel in the 45-degree direction would be the safest and most suitable for the fibular tunnel. METHODS: Forty-eight fibular tunnels were drilled on fresh ankle specimens using a K-wire guide and a 5.0 mm hollow drill. Three tunnel orientations were created, parallel to the sagittal plane of the long axis of the fibula and angled 30°, 45°, and 60° to the coronal plane. The length of the fibular tunnel and the distances from the outlet of the K-wire to the peroneus longus and brevis tendons were measured. The occurrence of a fibula fracture was also observed. RESULTS: The lengths of the bone tunnels in the three groups were 32.9 ± 6.1 mm (30°), 27.2 ± 4.4 mm (45°) and 23.6 ± 4.0 mm (60°). The length of the tunnel drilled at 30° was the longest when compared with that of the tunnels drilled at 45° and 60° (all p values < 0.05). The distances from the outlet of the K-wire to the peroneus longus tendon were 3.0 ± 3.8 mm (30°), 3.8 ± 3.2 mm (45°) and 5.3 ± 1.8 mm (60°), and the distances to the peroneus brevis tendon were 4.2 ± 4.0 mm (30°), 6.1 ± 3.8 mm (45°), 7.9 ± 3.5 mm (60°). In terms of protecting the peroneus longus and brevis tendons, drilling in the 60° direction was better than drilling in the 30° and 45° directions (all p values < 0.05). The risk of injury to the peroneal longus and brevis tendons was 62.5% (30°), 31.3% (45°), and 0% (60°). Although no fibular fractures were observed in any of the three directions, drilling the bone tunnel in the 60° direction disrupted the lateral cortex of the fibula. CONCLUSION: This study shows that drilling the tunnel in the 45° direction is less likely to cause injury to the peroneus longus and brevis tendons, while ensuring that the tunnel has a sufficient length and avoiding fracturing the distal fibula. Drilling a fibular bone tunnel in a 45° direction is safer and recommended for ATFL reconstruction.
Subject(s)
Fibula , Lateral Ligament, Ankle , Humans , Fibula/surgery , Lateral Ligament, Ankle/surgery , Ankle Joint/surgery , Tendons/surgery , AnkleABSTRACT
Although synthesis of oligoaniline (OANI) by persulfate and aniline has been investigated in the recent years, the impact of phenol on the synthesized soluble OANI is still not clear. In this study, our results indicate that phenol and pH mediate the production of the blue water-soluble OANI (OANIblue) in the reaction between sodium persulfate (SPS) and aniline under alkaline conditions, and the yields of OANIblue increase with increasing concentrations of phenol and pH values. Quenching experiments rule out the contributions of SO4Ë- and ËOH to aniline oxidation and imply that the non-radical activation of SPS is an important pathway in the formation of OANIblue. MALDI-TOF-MS analysis indicates that phenol apparently inhibits the polymerization degree of aniline in that the molecular weights of OANIblue gradually decrease from 1586.4 to 684.6 when phenol is increased from 0 to 2.0 mM. FTIR and Raman analyses confirm the structure of aniline oligomers in OANIblue and indicate that phenol inhibits the phenazine-like structure in OANIblue and facilitates the transformation of benzenoid rings to quinoid rings in the oxidation products. However, simultaneous activation of SPS by phenol and aniline is likely to occur in the reaction system with the formation of PhNHË, as indicated by DFT calculations. The high scavenging reactivity of phenol towards both PhNH2Ë+ and PhNHË implies that PhNH2Ë+ and PhNHË are not the intermediates in the formation of OANIblue. DFT calculations also reveal that apart from the one-electron transfer pathway between aniline and SPS, the two-electron transfer pathway is also likely to occur in the presence of phenol, resulting in the formation of PhNH+/PhNËË without producing PhNH2Ë+ and PhNHË. The produced PhNH+/PhNËË intermediates then couple with aniline, PhNH+, aminophenyl sulfate and its hydrolysate to form dimers, trimers, oligomers, and eventually OANIblue. This study not only describes a novel method to prepare water-soluble OANI, but also gives new insight on the importance of phenol in the production of OANIblue.
Subject(s)
Water Pollutants, Chemical , Water Purification , Aniline Compounds/chemistry , Oxidation-Reduction , Phenol/chemistry , Phenols , Sulfates/chemistry , Water , Water Pollutants, Chemical/chemistry , Water Purification/methodsABSTRACT
BACKGROUND: The clinical staging systems for adenocarcinoma of the esophagogastric junction (AEG) are controversial. We aimed to propose a prognostic nomogram based on real-world data for predicting survival of Siewert type II/III AEG patients after surgery. METHODS: A total of 396 patients with Siewert type II/III AEG diagnosed and treated at the Center for Gastrointestinal Surgery, the First Affiliated Hospital, Sun Yat-sen University, from June 2009 to June 2017 were enrolled. The original data of 29 variables were exported from the electronic medical records system. The nomogram was established based on multivariate Cox regression coefficients, and its performance was measured using Harrell's concordance index (C-index), receiver operating characteristic (ROC) curve analysis and calibration curve. RESULTS: A nomogram was constructed based on nine variables. The C-index for overall survival (OS) prediction was 0.76 (95% CI, 0.72 to 0.80) in the training cohort, in the validation-1 cohort was 0.79 (95% CI, 0.72 to 0.86), and 0.73 (95% CI, 0.67 to 0.80) in the validation-2 cohort. Time-dependent ROC curves and calibration curves in all three cohorts showed good prognostic predictive accuracy. We further proved the superiority of the nomogram in predictive accuracy for OS to pathological TNM (pTNM) staging system and other independent prognostic factors. Kaplan-Meier survival curves demonstrated the pTNM stage, grade of differentiation, positive lymph node, log odds of positive lymph node and organ invasion were prognostic factors with good discriminative ability. CONCLUSION: The established nomogram demonstrated a more precise prognostic prediction for patients with Siewert type II/III AEG.
Subject(s)
Adenocarcinoma/mortality , Esophageal Neoplasms/mortality , Esophagogastric Junction , Nomograms , Stomach Neoplasms/mortality , Adenocarcinoma/pathology , Adult , Aged , Aged, 80 and over , Esophageal Neoplasms/pathology , Female , Humans , Male , Middle Aged , Neoplasm Staging , Prognosis , Stomach Neoplasms/pathologyABSTRACT
A novel two-dimensional Cd-based metal-organic framework (MOF), [Cd(pddb)H2O]n (Cd-MOF), has been hydrothermally synthesized using the V-shaped ligand 4,4'-(pyridine-2,6-diyl)-dibenzoic acid (H2pddb) and structurally characterized. The framework exhibits fascinating one-dimensional in-plane channels functionalized with active pyridine-N sites. The as-synthesized Cd-MOF exhibits excellent water and chemical stability. Furthermore, a simple and nondestructive coordinated postsynthetic modification method has been applied to Cd-MOF to obtain a class of MOF hybrids functionalized by lanthanide ions. More interestingly, Eu3+@Cd-MOF can act as a dual-emissive ratiometric fluorescent probe for 2-(2-methoxyethoxy) acetic acid (MEAA), a metabolite of 2-(2-methoxyethoxy) ethanol, which could result in DNA damage and teratogenic and developmental toxicity. During the sensing process, the fluorescence sensor exhibits notable water tolerance, reusability, and a low detection limit (8.5 µg mL-1). In addition, the chemical substances in human urine and serum do not interfere with the fluorescence quenching process, which makes it possible for the fluorescent probe to be applied in the detection of MEAA in human urine and serum systems. The possible sensing mechanism is also studied and discussed in detail.
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PURPOSE: BTB domain-containing 7 (BTBD7) has been found to regulate epithelial tissue remodeling and branched organ formation and has been reported to modulate the biological behavior of several cancers. However, its role in breast cancer has not been identified. This study investigated the biological role and prognostic value of BTBD7 in breast cancer. METHODS: We identified the BTBD7 expression pattern using the GENT2 database and assessed its expression in breast cancer tissue and cell lines using quantitative reverse transcription polymerase chain reaction, western blot, and immunohistochemistry. We conducted a clinical relevance and survival analysis on a cohort of 121 breast cancer cases from our follow-up and validated it in a Kaplan-Meier plotter. The gain-loss effect of BTBD7 on cell proliferation, invasion, and migration was detected in vitro. We employed a xenograft mouse metastatic model for in vivo validation and performed a Cignal Finder Cancer 10-Pathway Reporter Array, western blot, immunofluorescence, Cell Counting Kit-8, and transwell invasion/migration assays to analyze the potential mechanism. RESULTS: BTBD7 was downregulated in human breast cancer cell lines and tissues. Decreased BTBD7 expression correlated with a positive lymph node status, lymphovascular invasion, and TNM stage, while high BTBD7 expression correlated with low breast cancer recurrence. BTBD7 suppressed cell proliferation, invasion/migration, and tumor metastasis in breast cancer. The mechanism studied suggested that the inhibitory role of BTBD7 was through the deactivation of Notch1 signaling in breast cancer. CONCLUSION: BTBD7 suppresses tumor progression, and its high expression correlates with low recurrence in breast cancer.
Subject(s)
BTB-POZ Domain , Breast Neoplasms , Adaptor Proteins, Signal Transducing , Animals , Breast Neoplasms/genetics , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation , Female , Gene Expression Regulation, Neoplastic , Humans , Mice , Neoplasm Recurrence, Local/genetics , Receptor, Notch1/genetics , Receptor, Notch1/metabolismABSTRACT
The fast development of solid-liquid phase change materials calls for nanomaterials with large specific surface area for rapid heat transfer and encapsulation of phase change materials to prevent potential leakage. Here we report a combined miniemulsion/emulsion polymerization method to prepare poly(styrene-co-acrylic acid)-encapsulated paraffin (paraffin@P(St-co-AA)) nanocapsules. The method could suppress the shortcomings of common miniemulsion polymerization (such as evaporation of monomer and decomposition of initiator during ultrasonication). The paraffin@P(St-co-AA) nanocapsules are uniform in size and the polymer shell can be controlled by the weight ratio of St to paraffin. The phase change behavior of the nanocapsules is similar to that of pure paraffin. We believe our method can also be utilized to synthesize other core-shell phase change materials.
ABSTRACT
Previous studies show that vanadium oxides suffer from severe capacity loss during cycling in the liquid electrolyte, which has hindered their applications in electrochemical energy storage. The electrochemical instability is mainly due to chemical dissolution and structural pulverization of vanadium oxides during charge/discharge cyclings. In this study the authors demonstrate that amorphous mixed-valence vanadium oxide deposited on exfoliated carbon cloth (CC) can address these two limitations simultaneously. The results suggest that tuning the V4+ /V5+ ratio of vanadium oxide can efficiently suppress the dissolution of the active materials. The oxygen-functionalized carbon shell on exfoliated CC can bind strongly with VO x via the formation of COV bonding, which retains the electrode integrity and suppresses the structural degradation of the oxide during charging/discharging. The uptake of structural water during charging and discharging processes also plays an important role in activating the electrode material. The amorphous mixed-valence vanadium oxide without any protective coating exhibits record-high cycling stability in the aqueous electrolyte with no capacitive decay in 100 000 cycles. This work provides new insights on stabilizing vanadium oxide, which is critical for the development of vanadium oxide based energy storage devices.
ABSTRACT
Calcium-dependent protein kinases (CDPKs) and CDPK-related kinases (CRKs) play multiple roles in plant. Nevertheless, genome-wide identification of these two families is limited to several plant species, and role of CRKs in disease resistance remains unclear. In this study, we identified the CDPK and CRK gene families in genome of the economically important crop tomato (Solanum lycopersicum L.) and analyzed their function in resistance to various pathogens. Twenty-nine CDPK and six CRK genes were identified in tomato genome. Both SlCDPK and SlCRK proteins harbored an STKc_CAMK type protein kinase domain, while only SlCDPKs contained EF-hand type Ca(2+) binding domain(s). Phylogenetic analysis revealed that plant CRK family diverged early from CDPKs, and shared a common ancestor gene with subgroup IV CDPKs. Subgroup IV SlCDPK proteins were basic and their genes contained 11 introns, which were distinguished from other subgroups but similar to CRKs. Subgroup I SlCDPKs generally did not carry an N-terminal myristoylation motif while those of the remaining subgroups and SlCRKs universally did. SlCDPK and SlCRK genes were differently responsive to pathogenic stimuli. Furthermore, silencing analyses demonstrated that SlCDPK18 and SlCDPK10 positively regulated nonhost resistance to Xanthomonas oryzae pv. oryzae and host resistance to Pseudomonas syringae pv. tomato (Pst) DC3000, respectively, while SlCRK6 positively regulated resistance to both Pst DC3000 and Sclerotinia sclerotiorum in tomato. In conclusion, CRKs apparently evolved from CDPK lineage, SlCDPK and SlCRK genes regulate a wide range of resistance and SlCRK6 is the first CRK gene proved to function in plant disease resistance.
Subject(s)
Calmodulin-Binding Proteins/genetics , Plant Diseases/genetics , Protein Kinases/genetics , Solanum lycopersicum/genetics , Amino Acid Sequence , Disease Resistance/genetics , Gene Expression Regulation, Plant , Genome, Plant , Solanum lycopersicum/microbiology , Multigene Family/genetics , Phylogeny , Plant Diseases/microbiology , Pseudomonas syringae/pathogenicityABSTRACT
Fatty acid-binding protein 5 (FABP5) was found in our previous study to be a potential biomarker for lymph node metastasis of cervical cancer. However, the roles of FABP5 in cervical cancer remain unclear. In the present study, FABP5 expression was found to be significantly upregulated in cervical cancer tissues, and high FABP5 expression was significantly correlated with lymph node metastasis, lymphovascular space invasion, the International Federation of Gynecology and Obstetrics (FIGO) stage, and tumor size. Moreover, FABP5 was an independent factor for poor prognosis in cervical cancer patients. Silencing of FABP5 inhibited cell proliferation, colony formation, cell migration, and invasion in vitro. Furthermore, FABP5 silencing significantly reduced tumor growth and lung metastases in a murine allograft model in vivo. In addition, FABP5 silencing decreased the expression of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) in vitro and in vivo. Collectively, these findings indicated that FABP5 plays an important role in the carcinogenesis and metastasis of cervical cancer, and FABP5 may be a novel predictor for prognostic assessment of cervical cancer patients.
Subject(s)
Biomarkers, Tumor/genetics , Carcinogenesis/genetics , Cell Proliferation/genetics , Fatty Acid-Binding Proteins/genetics , Uterine Cervical Neoplasms/pathology , Adult , Animals , Cell Line, Tumor , Cell Movement/genetics , Female , HeLa Cells , Humans , Lung Neoplasms/secondary , Lymphatic Metastasis , Matrix Metalloproteinase 2/biosynthesis , Matrix Metalloproteinase 9/biosynthesis , Mice , Mice, Nude , Neoplasm Invasiveness/genetics , Prognosis , RNA Interference , RNA, Small Interfering , Uterine Cervical Neoplasms/mortalityABSTRACT
OBJECTIVE: The aim of the study was to investigate the long-term oncological outcomes of laparoscopic radical hysterectomy (LRH) and abdominal radical hysterectomy (ARH) for treatment of stage IA2 to IIA2 cervical cancer. METHODS: We matched stage IA2 to IIA2 cervical cancer patients with known risk factors for recurrence who underwent ARH or LRH. RESULTS: After matching, a total of 203 patient pairs (LRH-ARH) were included. The LRH and ARH group had similar 5-year recurrence-free survival (RFS) rates (91.3% vs 90.4%, P = 0.83) and overall survival (OS) rates (93.2% vs 92.1%, P = 0.94). Patients with different tumor size (≤2, 2-4, >4 cm) had similar 5-year OS and RFS. Even in patients with pelvic lymph node metastasis, the 5-year RFS (69.20% vs 69.20%, P = 0.87) and OS (77.4% vs 76.3%, P = 0.83) did not differ statistically between the 2 groups. The LRH and ARH group had similar mean time to recurrence (16.29 vs 22.15 months, P = 0.68) and pattern of recurrence (P = 0.63). Compared with ARH, LRH resulted in significantly shorter operating time, less blood loss, and shorter hospital stay. The intraoperative complications rate was similar between the 2 groups (P = 0.72). The rate of postoperative complications was significantly lower in the LRH group than in the ARH group (P = 0.004). CONCLUSIONS: Laparoscopic radical hysterectomy was associated with fewer operating time, blood loss, postoperative complication, and earlier recovery. Laparoscopic radical hysterectomy is an oncologically safe alternative to ARH.
Subject(s)
Carcinoma/surgery , Hysterectomy/statistics & numerical data , Postoperative Complications/epidemiology , Uterine Cervical Neoplasms/surgery , Adult , Carcinoma/mortality , China/epidemiology , Cohort Studies , Female , Humans , Hysterectomy/adverse effects , Hysterectomy/methods , Laparoscopy/adverse effects , Laparoscopy/statistics & numerical data , Middle Aged , Postoperative Complications/etiology , Uterine Cervical Neoplasms/mortalityABSTRACT
Ammonium ylides have a long history in organic synthesis, but their application in asymmetric catalysis is still underdeveloped in regard to both substrate scope and reaction pathways compared with phosphorus and sulfur ylides. Here a previously unreported asymmetric [4 + 1] annulation reaction of 3-bromooxindoles and electron-deficient 1-azadienes has been developed through ammonium ylide catalysis of a newly designed 2'-methyl α-isocupreine (α-MeIC), efficiently delivering spirocyclic oxindole compounds incorporating a dihydropyrrole motif in excellent enantioselectivity (up to 99% ee). To the best of our knowledge, this work represents the first example of asymmetric catalysis of ammonium ylides bearing α-substitutions, and the catalytic [4 + 1] annulation pathway of ammonium ylides is also unprecedented. Moreover, (1)H NMR, mass spectroscopy, and computational calculation studies were conducted, and the catalytic cycle and a tentative explanation of the enantioselective mechanism have been successfully elucidated.
Subject(s)
Ammonium Compounds/chemistry , Indoles/chemistry , Catalysis , Models, Molecular , Molecular Conformation , Oxindoles , StereoisomerismABSTRACT
Bufalin, a major digoxin-like immunoreactive component of the Chinese medicine Chan Su, has been shown to exert a potential for anticancer activity against various human cancer cell lines in vitro. However, no detailed studies have so far been reported on its action on human gallbladder carcinoma cells. In this study, bufalin remarkably inhibited growth in human gallbladder cancer cells by decreasing cell proliferation, inducing cell cycle arrest and apoptosis in a dose-dependent manner. Bufalin also disrupted the mitochondrial membrane potential (ΔΨm) and regulated the expression of cell cycle and apoptosis regulatory molecules. Activation of caspase-9 and the subsequent activation of caspase-3 indicated that bufalin may be inducing mitochondria apoptosis pathways. Intraperitoneal injection of bufalin for 3 weeks significantly inhibited the growth of gallbladder carcinoma (GBC-SD) xenografts in athymic nude mice. Taken together, the results indicate that bufalin may be a potential agent for the treatment of gallbladder cancer.
Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , Bufanolides/pharmacology , Cell Cycle Checkpoints/drug effects , Gallbladder Neoplasms/pathology , Animals , Blotting, Western , Caspases/metabolism , Cell Proliferation/drug effects , Gallbladder Neoplasms/drug therapy , Gallbladder Neoplasms/metabolism , Humans , Male , Membrane Potential, Mitochondrial/drug effects , Mice , Mice, Nude , Signal Transduction/drug effects , Tumor Cells, Cultured , Xenograft Model Antitumor AssaysABSTRACT
Gallbladder carcinoma is the most common malignancy of the biliary tract, with a very low 5-year survival rate and extremely poor prognosis. Thus, new effective treatments and drugs are urgently needed for the treatment of this malignancy. In this study, for the first time we investigated the effects of triptolide on gallbladder cancer cells and identified the mechanisms underlying its potential anticancer effects. The MTT assay showed that triptolide decreased cell viability in a dose- and time-dependent manner. The results of the colony formation assay indicated that triptolide strongly suppressed colony formation ability in GBC-SD and SGC-996 cells. Flow cytometric analysis revealed that triptolide induced S phase arrest in gallbladder cancer cells. In addition, triptolide induced apoptosis, as shown by the results of annexin V/propidium iodide double-staining and Hoechst 33342 staining. Furthermore, triptolide decreased mitochondrial membrane potential (ΔΨm) in a dose-dependent manner. Finally, western blot analysis of triptolide-treated cells revealed the activation of caspase-3, caspase-9, PARP, and Bcl-2; this result demonstrated that triptolide induced apoptosis in gallbladder cancer cells by regulating apoptosis-related protein expression, and suggests that triptolide may be a promising drug to treat gallbladder carcinoma.
Subject(s)
Apoptosis/drug effects , Diterpenes/chemistry , Gallbladder Neoplasms/drug therapy , Phenanthrenes/chemistry , S Phase/drug effects , Caspase 3/biosynthesis , Caspase 9/biosynthesis , Cell Cycle Checkpoints/drug effects , Cell Line, Tumor , Diterpenes/administration & dosage , Epoxy Compounds/administration & dosage , Epoxy Compounds/chemistry , Gallbladder Neoplasms/pathology , Gene Expression Regulation, Neoplastic/drug effects , Humans , Phenanthrenes/administration & dosage , Proto-Oncogene Proteins c-bcl-2/biosynthesisABSTRACT
Objective: This prospective study is to explore the role of specific circRNAs in predicting the development of bronchopulmonary dysplasia (BPD). Methods: From July 1, 2021 to December 1, 2021, peripheral blood samples were collected from 62 premature infants with gestational age (GA) ≤32 weeks on the 7th, 14th, and 28th day after birth. Then, on the 28th day, the included infants were divided into the BPD group and the non-BPD group according to the definition of BPD. Serum exosomal circRNAs from peripheral blood were identified, sequenced, and compared between the BPD and non-BPD groups at different time points. Specific differentially expressed circRNAs were further verified from another 42 enrolled premature infants (GA ≤32 weeks). The classical lung biological markers in serum were also measured simultaneously. Results: Hsa_circ_0001359 in serum exosomes showed continuous differential expression between the BPD group and the non-BPD group on the 7th, 14th, and 28th day. Compared with that, classical lung biological markers like IL-6, IL-33, KL-6, and ET-1 did not exhibit continuous differences. Moreover, the expression of hsa_circ_0001359 on day 7 had a higher predictive value in predicting BPD (area under curve:0.853, 95% CI:0.738-0.968; adjusted odds ratio:6.033, 95% CI:2.373-13.326). The calibration curve further showed the mean absolute error = 0.033, mean squared error = 0.00231, and quantile of absolute error = 0.058. Conclusion: Hsa_circ_0001359 in serum exosomes is a promising marker for predicting BPD in preterm infants with gestational age ≤32 weeks.
ABSTRACT
Codonopsis pilosula is a famous edible and medicinal plants, in which polysaccharides are recognized as one of the important active ingredients. A neutral polysaccharide (CPP-1) was purified from C. pilosula. The structure was characterized by HPSEC-MALLS-RID, UV, FT-IR, GC-MS, methylation analysis, and NMR. The results showed that CPP-1 was a homogeneous pure polysaccharide, mainly containing fructose and glucose, and a small amount of arabinose. Methylation analysis showed that CPP-1 composed of â1)-Fruf-(2â, Fruf-(1â and Glcp-(1â residues. Combined the NMR results the structure of CPP-1 was confirmed as α-D-Glcp-(1 â [2)-ß-D-Fruf-(1 â 2)-ß-D-Fruf-(1]26 â 2)-ß-D-Fruf with the molecular weight of 4.890 × 103 Da. The model of AML12 hepatocyte fat damage was established in vitro. The results showed that CPP-1 could increase the activity of SOD and CAT antioxidant enzymes and reduce the content of MDA, thus protecting cells from oxidative damage. Subsequently, the liver protective effect of CPP-1 was studied in the mouse model of nonalcoholic fatty liver disease (NAFLD) induced by the high-fat diet. The results showed that CPP-1 significantly reduced the body weight, liver index, and body fat index of NAFLD mice, and significantly improved liver function. Therefore, CPP-1 should be a potential candidate for the treatment of NAFLD.
Subject(s)
Codonopsis , Non-alcoholic Fatty Liver Disease , Animals , Mice , Non-alcoholic Fatty Liver Disease/drug therapy , Codonopsis/chemistry , Spectroscopy, Fourier Transform Infrared , Polysaccharides/pharmacology , Polysaccharides/therapeutic use , Polysaccharides/chemistry , Antioxidants/pharmacologyABSTRACT
In the first successful catalytic asymmetric Diels-Alder reaction in 1979, Koga and colleagues used a chiral aluminum complex as a Lewis acid catalyst, but since then, researchers have developed numerous catalytic systems for these reactions. By 2000, several chiral organic compounds, such as the salts of imidazolidinones or TADDOLs, emerged as robust catalysts in the asymmetric Diels-Alder reactions. According to frontier molecular orbital theory, most of these catalysts employ a LUMO-lowering strategy as a means of activating electron-deficient dienophiles. Only rarely do chiral catalysts take advantage of the alternative strategy of activating the HOMO. In this Account we will discuss the development of asymmetric Diels-Alder reactions based on the HOMO-raising effects of chiral amines. First, we show that enamine intermediates formed in situ between an amine catalyst and enolizable aliphatic aldehydes can act as electron-rich dienophiles in inverse-electron-demand Diels-Alder reactions. We describe the preparation of a variety of oxygen- or nitrogen-containing heterocycles with high optical purity. Then, we demonstrate that the dienamine species from α,ß-unsaturated aldehydes can act either as electron-rich dienes in normal-electron-demand Diels-Alder reactions or as dienophiles in inverse-electron-demand Diels-Alder reactions. These reactions generally occur with high chemo-, regio-, and stereoselectivity. Finally, we introduce a new activation mode for Diels-Alder reactions, in which reactive trienamine intermediates derived from 2,4-dienals or even 2,4-dienones play a key role. Notably, we observe remarkable ß,ε-regioselectivity and obtain excellent stereocontrol even at the very remote ε-reactive center-up to seven bonds away from the chiral center of the amine catalyst. These results demonstrate that a HOMO-activation strategy via aminocatalysis could become a significant tool in asymmetric Diels-Alder reactions. In addition, these reactions using enamine, dienamine, or trienamine intermediates produce a diverse array of densely functionalized cyclic scaffolds, which may serve as valuable structures in drug discovery and natural product synthesis.
Subject(s)
Amines/chemistry , Quantum Theory , Aldehydes/chemistry , Amines/chemical synthesis , Catalysis , Molecular StructureABSTRACT
BACKGROUND: Gallbladder carcinoma is a malignant tumor with a very low 5-year survival rate because of the difficulty with its early diagnosis and the very poor prognosis of the advanced cancer state. The aims of this study were to determine whether curcumin could induce the apoptosis of a gallbladder carcinoma cell line, GBC-SD, and to clarify its related mechanism. METHODS: First, the anti-proliferative activities of curcumin-treated and untreated GBC-SD cells were determined using the MTT and colony formation assays. Then, the early apoptosis of cells was detected by the annexin V/propidium iodide double-staining assay and Hoechst 33342 staining assay. Detection of mitochondrial membrane potential was used to validate the ability of curcumin on inducing apoptosis in GBC-SD cells. Cell cycle changes were detected by flow cytometric analysis. Finally, the expressions of the apoptosis-related proteins or genes caspase-3, PARP, Bcl-2, and Bax were analyzed by western blot and quantitative real time PCR assay. Statistical analyses were performed using the Student's t-test for comparison of the results obtained from cells with or without curcumin treatment. RESULTS: The MTT assay revealed that curcumin had induced a dose- and a time-dependent decrease in cell viability. Colony counting indicated that curcumin had induced a dose-dependent decrease in the colony formation ability in GBC-SD cells. Cells treated with curcumin were arrested at the S phase, according to the flow cytometric analysis. A significant induction of both the early and late phases of apoptosis was shown by the annexin V-FITC and PI staining. Morphological changes in apoptotic cells were also found by the Hoechst 33342 staining. After treatment with curcumin fluorescence shifted from red to green as ΔΨm decreased. Furthermore, western blot and quantitative real time PCR assays demonstrated that the curcumin induced apoptosis in GBC-SD cells by regulating the ratio of Bcl-2/Bax and activating the expression of cleaved caspase-3. CONCLUSIONS: Taken together, the results indicate that curcumin may be a potential agent for the treatment of gallbladder cancer.
ABSTRACT
Chiral Lewis basic tertiary amines or phosphines can enable properly modified Morita-Baylis-Hillman (MBH) adducts to undergo asymmetric allylic substitutions with a wide range of nucleophiles. In addition, assisted by a Brønsted base, chiral Lewis bases can also catalytically convert modified MBH adducts into allylic ylides, which can be engaged in a variety of asymmetric annulation reactions. This tutorial review will focus on such chiral Lewis base-catalysed asymmetric transformations of MBH adducts, especially those developed over the past five years, allowing for the rapid construction of densely functionalised chiral molecules with high levels of regio- and stereoselectivities.
Subject(s)
Lewis Bases/chemistry , Alkylation , Amines/chemistry , Catalysis , Cyclization , Phosphines/chemistry , StereoisomerismABSTRACT
OBJECTIVES: Currently, most colorectal neoplasia (CRN) screening strategies target asymptomatic individuals. However, studies on patients with non-specific gastrointestinal symptoms (NSGS) are limited. We aimed to develop a CRN risk score specifically for patients with NSGS. METHODS: We prospectively enrolled patients who underwent initial colonoscopy between June 2020 and June 2021. A new risk scoring system was constructed and its applicability was evaluated. RESULTS: A total of 1522 consecutive patients were enrolled, among whom 1016 symptomatic patients were randomly divided into a training cohort and a validation cohort at a ratio of 7:3. The constructed Symptomatic Patients Colorectal Screening (SPCS) score showed higher diagnostic efficacy and sensitivity than several previous scoring systems. Using the SPCS score, the patients were divided into a low-risk group (-2 to 3 points) and a high-risk group (4-10 points) for CRN. Additionally, the detection rate of CRN in the training and validation cohorts of the high-risk group were 41.7% and 37.0%, respectively. The SPCS score detected 79.3% (188/237) of CRN and 87.5% (42/48) of advanced CRN in the high-risk group, which reduced the workload of colonoscopy to 45.9% (466/1016). CONCLUSION: An effective CRN risk scoring system was established and validated for symptomatic patients, which accurately classified individuals into low-risk and high-risk groups for CRN and might be used to optimize colonoscopic resource allocation.
Subject(s)
Colonoscopy , Colorectal Neoplasms , Humans , Colorectal Neoplasms/diagnosis , Early Detection of Cancer , Risk FactorsABSTRACT
2D lead halide perovskites (LHPs) show strong excitonic and spin-orbit coupling effects, generating a facile spin injection. Besides, they possess a polaron character due to the soft crystal lattice, which can prolong the spin lifetime, making them favorable materials for spintronic applications. Here, the spin dynamics of 2D PEA2 PbI4 (MAPbI3 )n -l thin films with different layers by temperature- and pump fluence-dependent circularly polarization-resolved transient absorption (TA) measurements is studied. These results indicate that the spin depolarization mechanism is gradually converted from the Maialle-Silva-Sham (MSS) mechanism to the polaronic states protection mechanism with the layer number increasing from