A density functional theory study on the mechanism of toluene from dimethylcyclopentane catalyzed by the [GaH]2+ active site of Ga-ZSM-5.

The ONIOM (ωb97xd/6-31G(d,p):pm6) method was used to study the reaction mechanism of dimethylcyclopentane to toluene by the [GaH]2+ active site of Ga-ZSM-5. The results showed that the rate-determining step in the dimethylcyclopentane aromatization process is the ring expansion process. Compared to those of methylcyclopentane to benzene (D. D. Zhang, H. Y. Liu, L. X. Ling, H. R. Zhang, R. G. Zhang, P. Liu and B. J. Wang, Phys. Chem. Chem. Phys., 2021, 23, 10988-11003.), the free energy barriers of dimethylcyclopentane to toluene are significantly decreased, indicating that toluene is easier to produce than benzene, which confirmed the experimental results that a higher proportion of toluene than benzene is produced in the MTA process.

Detection of cell-surface sialic acids and photodynamic eradication of cancer cells using dye-modified polydopamine-coated gold nanobipyramids.

A nanoprobe based on polydopamine-coated gold nanobipyramids surface modified with molecules of a phenylboronic acid-substituted distyryl boron dipyrromethene has been fabricated and characterised using various physical and spectroscopic methods. It serves as an ultrasensitive sensor for sialic acids on the surface of cancer cells based on its dual surface-enhanced Raman scattering and fluorescence response. This biomarker can also trigger the photodynamic activity of these nanobipyramids, effectively eradicating the cancer cells mainly through apoptosis as shown by various bioassays.

Oxygen Vacancy-Rich Mixed-Valence Cerium MOF: An Efficient Separator Coating to High-Performance Lithium-Sulfur Batteries.

Mixed-valence metal-organic frameworks (MOFs) have exhibited unique potential in fields such as catalysis and gas separation. However, it is still an open challenge to prepare mixed-valence MOFs with isolated Ce(IV, III) arrays due to the easy formation of CeIII under the synthetic conditions for MOFs. Meanwhile, the performance of Li-S batteries is greatly limited by the fatal shuttle effect and the slow transmission rate of Li+ caused by the inherent characteristics of sulfur species. Here, we report a mixed-valence cerium MOF, named CSUST-1 (CSUST stands for Changsha University of Science and Technology), with isolated Ce(IV, III) arrays and abundant oxygen vacancies (OVs), synthesized as guided by the facile and elaborate kinetic stability study of UiO-66(Ce), to work as an efficient separator coating for circumventing both issues at the same time. Benefiting from the synergistic function of the Ce(IV, III) arrays (redox couples), the abundant OVs, and the open Ce sites within CSUST-1, the CSUST-1/CNT composite, as a separator coating material in the Li-S battery, can remarkably accelerate the redox kinetics of the polysulfides and the Li+ transportation. Consequently, the Li-S cell with the CSUST-1/CNT-coated separator exhibited a high initial specific capacity of 1468 mA h/g at 0.1 C and maintained long-term stability for a capacity of 538 mA h/g after 1200 cycles at 2 C with a decay rate of only 0.037% per cycle. Even at a high sulfur loading of 8 mg/cm2, the cell with the CSUST/CNT-coated separator still demonstrated excellent performance with an initial areal capacity of 8.7 mA h/cm2 at 0.1 C and retained the areal capacity of 6.1 mA h/cm2 after 60 cycles.

Influence of graphene on the multiple metabolic pathways of Zea mays roots based on transcriptome analysis.

Graphene reportedly exerts positive effects on plant root growth and development, although the corresponding molecular response mechanism remains to be elucidated. Maize seeds were randomly divided into a control and experimental group, and the roots of Zea mays L. seedlings were watered with different concentrations (0-100 mg/L) of graphene to explore the effects and molecular mechanism of graphene on the growth and development of Z. mays L. Upon evaluating root growth indices, 50 mg/L graphene remarkably increased total root length, root volume, and the number of root tips and forks of maize seedlings compared to those of the control group. We observed that the contents of nitrogen and potassium in rhizosphere soil increased following the 50 mg/L graphene treatment. Thereafter, we compared the transcriptome changes in Z. mays roots in response to the 50 mg/L graphene treatment. Transcriptional factor regulation, plant hormone signal transduction, nitrogen and potassium metabolism, as well as secondary metabolism in maize roots subjected to graphene treatment, exhibited significantly upregulated expression, all of which could be related to mechanisms underlying the response to graphene. Based on qPCR validations, we proposed several candidate genes that might have been affected with the graphene treatment of maize roots. The transcriptional profiles presented here provide a foundation for deciphering the mechanism underlying graphene and maize root interaction.

A nomogram to predict lymph node metastasis before resection in intrahepatic cholangiocarcinoma.

BACKGROUND: In this study, we developed and validated a nomogram to predict lymph node metastasis before surgery in patients with intrahepatic cholangiocarcinoma (ICC). METHODS: Using the data from January 2006 to January 2015, we enrolled a total of 218 eligible patients with clinicopathologically confirmed ICC as a primary cohort to develop the nomogram. After various variables before surgery were analyzed by multivariable logistic regression, we combined the preoperative carbohydrate antigen 19-9, primary site of tumor, lymphonodus size on computed tomography imaging, tumor growth pattern, and (if applicable) histologic grade to make two different predictive nomograms. Then, the results were validated in 62 consecutive ICC patients from February 2015 to December 2016. We also compared the performance of the different nomograms via calibration, discrimination, and clinical use. RESULTS: The nomogram displayed fine discrimination (the concordance index, 0.761) and fine calibration in the primary cohort. When applied to the validation cohort, the nomogram also showed fine discrimination (concordance index, 0.794) and fine calibration. After adding the histologic grade to the nomogram, the integrated discrimination for predictive performance improved significantly. Finally, the clinical usefulness of predictive nomogram was proven via the decision curve analysis. CONCLUSIONS: The proposed nomograms can be selectively used to achieve more accurate lymph node metastasis predictions before surgery in patients with ICC, and this information can help with clinical management.

Risk Factors for Cholangiocarcinoma After Initial Hepatectomy for Intrahepatic Stones.

BACKGROUND: Aggressive hepatectomy is effective in treating intrahepatic stones and may minimize the deleterious consequences of subsequent cholangiocarcinoma (S-CCA). The risk factors of S-CCA after different methods of hepatectomy may vary with the resection scope of stone-affected segments. METHODS: We reviewed the records of 981 patients of primary intrahepatic stones with elective hepatectomy from January 2000 to December 2010. The clinical characteristics of patients in the S-CCA group (n = 55) and the control group (n = 926) were compared. The uniformity between extent of liver resection (ELR) with stone-affected segments (SAS) was segmented into 2 varieties: ELR = SAS with ELR < SAS according to the different hepatic resection scopes. Cox regression model with forward selection was used to identify the risk factors of S-CCA. RESULTS: In the univariate analysis, significant differences were observed between the S-CCA and control groups concerning stone location (unilateral 43.6 and 65.2 %, bilateral 56.4 and 34.8 %), residual stones (32.7 and 11.6 %), hepaticojejunostomy (43.6 and 30.9 %), and uniformity between ELR with SAS (ELR = SAS 20.0 and 42.6 %, ELR < SAS 80.0 and 57.4 %). Residual stones [hazard ratio (HR) 2.101, P = 0.016], hepaticojejunostomy (HR 1.837, P = 0.026) and uniformity between ELR and SAS (HR 2.442, P = 0.013) were independent prognostic factors for S-CCA by a Cox regression analysis with forward selection. In the subsection of ELR = SAS group, the 5- and 10-year postoperative tumor occurrence rates of unilateral and bilateral stones group were 0.9 versus 1.9 % and 3.0 versus 4.1 %, respectively (P = 0.663, log-rank). In the other subsection of ELR < SAS group, the 5- and 10-year postoperative tumor occurrence rates of unilateral and bilateral stones group were 3.4 versus 3.9 % and 6.8 versus 13.2 %, respectively (P = 0.047, log-rank), and the 5- and 10-year postoperative tumor occurrence rates of residual stones and non-residual stones group were 5.8 versus 3.0 % and 16.0 versus 7.9 %, respectively (P = 0.015, log-rank). CONCLUSIONS: Patients who underwent aggressive hepatectomy and had ELR = SAS had better outcomes than those with ELR < SAS. In the patients with ELR = SAS, the S-CCA rates of unilateral and bilateral stones were low and comparable. However, patients with ELR < SAS and bilateral intrahepatic or residual stones should be monitored more carefully for high-risk factors of S-CCA.

Multicolor Amplified Spontaneous Emissions Based on Organic Polymorphs That Undergo Excited-State Intramolecular Proton Transfer.

Two polymorphs emitting near-infrared (1 R form: α phase, λem =702 nm, Φf =0.41) and orange-red fluorescence (1 O form: ß phase, λem =618 nm, Φf =0.05) were synthesized by finely controlling the crystallization conditions of compound 1, a structurally simple excited-state intramolecular proton transfer (ESIPT)-active molecule. Multicolor amplified spontaneous emissions (ASEs) were realized, for the first time, based on these polymorphs. Notably, the 1 O crystal underwent heating-induced phase transformation from the ß phase to the α form in a single-crystal to single-crystal (SCSC) manner accompanied with an unprecedented ASE changing. The ASE behavior of polymorphs 1 R, 1 O as well as the ASE changing during SCSC was investigated. The feasibility of multicolor lasing based on the present organic polymorphs was confirmed, which may provide a new development strategy for organic laser science and technology.

Emission behaviors of unsymmetrical 1,3-diaryl-ß-diketones: a model perfectly disclosing the effect of molecular conformation on luminescence of organic solids.

A series of unsymmetrical 1,3-diaryl-ß-diketones 1-6 displaying molecular conformation-dependent fluorescence quantum yields have been synthesized. Crystals with planar molecular conformation such as 1, 2, 3 and 4 are highly fluorescent (φf: 39-53%), and the one holding slightly twisted conformation (5) is moderately luminescent (φf = 17%), while crystal 6 possessing heavily bent structure is completely nonluminous (φf ~ 0). The distinct fluorescence efficiencies are ascribed to their different molecular conformations, since all the crystals hold the same crystal system, space group and crystal packing structures. Additionally, the fluorescent crystals 1-5 display low threshold amplified spontaneous emission (ASE) with small full widths at half-maximum (FWHM: 3-7 nm), indicating their potential as candidates for organic crystal lasing devices.

Surgical treatment of a patient with peliosis hepatis: a case report.

This report describes a case of a space-occupying lesion in the right liver in a 38-year-old man who was found to have peliosis hepatis. Clinical data of this patient were presented, including medical history, laboratory test and imaging results, and postoperative pathological findings (hematoxylin and eosin staining). Review of his medical history showed that the patient had been bitten by a dog three years earlier. B-mode ultrasonography revealed an uneven echo mass in the right hemiliver, and magnetic resonance imaging scans also showed a mass in the anterior segment of the right liver. Upon surgical removal, the mass was found to be 4.0 cm × 3.8 cm × 3.8 cm in size and located in segment VI. The mass had a dark and soft appearance, with an irregular edge on intraoperative ultrasonography. Postoperative pathological findings revealed many small capsules filled with blood cells. The patient was diagnosed with peliosis hepatis based on his medical history of having been bitten by a dog, presence of mild anemia, and lack of characteristic symptoms, including fever of unknown origin, abdominal pain, and hepatosplenomegaly, combined with intraoperative and postoperative pathologic findings. The operation was successful, and after being treated with anti-infection agents, the patient had a good recovery.

Diagnosis and treatment of xanthogranulomatous cholecystitis: a report of 39 cases.

This study focuses on providing diagnosis and treatment for xanthogranulomatous cholecystitis (XGC). Clinical data from 39 patients diagnosed with XGC by pathological examination between 2002 and 2010 were analyzed retrospectively. As a result, in this group of patients, the male to female ratio was 30:9 and the average age of XGC onset was 62.2 years. Clinical manifestation of the disease was similar to general cholecystitis and preoperative CT examination showed that there were only 4 XGC cases, while the others were possibly misdiagnosed. Intraoperative observations showed that all the patients had gallbladder wall thickening. This was associated with gallbladder stones in 37 patients (94.9 %), choledocholith in 11 patients (28.2 %), and Mirizzi syndrome in 5 patients (12.8 %). In this study, intraoperative frozen section pathology was conducted in 14 patients and no gallbladder cancer was found. Laparoscopic cholecystectomy was performed on 7 patients, of which two were transferred to laparotomy. Of the remaining 32 cases, 25 were subjected to open cholecystectomy, 3 to partial cholecystectomy, and 4 to the cholecystectomy and partial liver wedge resection. It was concluded that XGC is a unique type of cholecystitis with atypical clinical manifestations and is often difficult to diagnose preoperatively. Pathological examination is a key to diagnose XGC and cholecystectomy is the primary surgical treatment. In patients with choledochectasia or jaundice, for whom we cannot exclude calculus of common bile duct, common bile duct exploration should be considered. The prognosis of XGC appears to be good with the above approaches.

Vascular endothelial growth factor-D promotes growth, lymphangiogenesis and lymphatic metastasis in gallbladder cancer.

Lymph node metastasis is a major prognostic factor for patients with gallbladder cancer (GBC), and greater understanding of the molecule mechanism of lymph node metastasis in GBC is needed to improve prognosis. VEGF-D has been implicated in the control of lymphangiogenesis in many carcinomas, but the biological function of VEGF-D in human GBC remains unclear. In this study, we analyzed the role of the VEGF-D in human GBC cells and addressed the functional role of VEGF-D using a xenograft mouse model. We examined the expression of VEGF-D in three human gallbladder cancer cell lines. A lentivirus-based effective VEGF-D siRNA vector was infected into GBC NOZ cells. The effect of VEGF-D siRNA on GBC NOZ cells was investigated by cell proliferation assay and invasion assay. Furthermore, we examined the role of VEGF-D-SiRNA on GBC NOZ cells in the mice of subcutaneous and orthotopic xenograft tumor. Our results are as follows: VEGF-D mRNA and protein were expressed in all three GBC cell lines (GBC-SD, NOZ, and SGC-996). We successfully selected D-3/siRNA as the most effective siRNA to silence VEGF-D expression after four VEGF-D siRNA plasmid transfection in NOZ cells. VEGF-D mRNA and protein expression were suppressed by lentivirus-mediated D-3/siRNA. D-3-RNAi-LV inhibited NOZ cells proliferation and invasion ability in vitro. D-3-RNAi-LV inhibited tumor growth and lymphangiogenesis in the NOZ cell subcutaneous xenograft model. D-3-RNAi-LV inhibited lymphangiogenesis and lymphatic metastasis in the NOZ cell orthotopic xenograft model. Furthermore, D-3-RNAi-LV inhibited tumor ascites and hepatic invasion in the NOZ cell orthotopic xenograft model. In conclusion, VEGF-D is involved and plays an important role in GBC progression, suggesting that VEGF-D may be a potential molecular target in the treatment of GBC.

SNCG gene silencing in gallbladder cancer cells inhibits key tumorigenic activities.

We recently determined that synuclein-gamma (SNCG) is highly expressed in human gallbladder cancer (GBC), and its abnormal expression is associated with tumor aggressiveness. To investigate the effects of SNCG gene silencing on the tumorigenic profiles of the GBC cell line, NOZ, short-hairpin RNA (shRNA) interference was employed. Specifically, the SNCG transcript was targeted by SNCG-shRNA lentiviral particles designed to silence SNCG gene expression. Following selection of NOZ cells stably expressing SNCG-shRNA, SNCG expression was examined by western blot and semi-quantitative RT-PCR analyses. Phenotypic hallmarks of gallbladder carcinogenesis were assayed by CCK-8, soft agar (colony formation), modified Boyden-Chamber (invasion), and flow cytometry (cell-cycle and apoptosis) assays. Our results showed that SNCG gene silencing in NOZ cells inhibited cell growth, colony formation, and invasion. In addition, it directly increased the effectiveness of paclitaxel in inducing G2/M cell-cycle arrest and cell apoptosis. Data from our in vivo study showed a decrease in tumor growth and weight in mice injected with SNCG-silenced NOZ cells. Together, these findings suggest that SNCG plays an important role in the progression of GBC.

Vascular endothelial growth factor-C promotes the growth and invasion of gallbladder cancer via an autocrine mechanism.

Vascular endothelial growth factor-C (VEGF-C) has a well-defined action on neoplastic lymphangiogenesis and angiogenesis through VEGF receptor-3 (VEGFR-3) and VEGFR-2, respectively, which are generally expressed in endothelial cells. The function of the VEGF-C/receptors pathway in tumor cell types is largely unknown. In this study, we examined the expression and role of VEGF-C/receptors in gallbladder cancer (GBC) cells. We examined the expression of VEGF-C in 50 surgical specimens from gallbladder cancer and three human gallbladder cancer cell lines. Both siRNA and neutralizing antibody to deplete the expression of VEGF-C were used to characterize the biological effect of VEGF-C in GBC NOZ cells. Furthermore, we examined the expression of its receptors, VEGFR-3 and VEGFR-2, in three human GBC cell lines. Our results are as follows: The expression of VEGF-C in the invasive marginal portion was significantly higher than the expression in the central portions. All the three GBC cell lines expressed VEGF-C. Treatment of NOZ cells with VEGF-C siRNA or a neutralizing antibody suppressed cell proliferation and invasion. Moreover, all the three GBC cell lines expressed VEGFR3, but only the NOZ cells expressed VEGFR-2 mRNA. Treatment of NOZ cells with a VEGFR-3 neutralizing antibody suppressed cell invasion, but treatment of NOZ cells with a VEGFR-2 neutralizing antibody suppressed cell proliferation and invasion. In conclusion, GBC cells express both VEGF-C and its receptors. VEGF-C may have a role in the progressive growth and invasion of human GBC through an autocrine mechanism.