Regulating Lewis Acidic Sites of 1T-2H MoS2 Catalysts for Solar-Driven Photothermal Catalytic H2 Production from Lignocellulosic Biomass.

Solar-driven photothermal catalytic H2 production from lignocellulosic biomass was achieved by using 1T-2H MoS2 with tunable Lewis acidic sites as catalysts in an alkaline aqueous solution, in which the number of Lewis acidic sites derived from the exposed Mo edges of MoS2 was successfully regulated by both the formation of an edge-terminated 1T-2H phase structure and tunable layer number. Owing to the abundant Lewis acidic sites for the oxygenolysis of lignocellulosic biomass, the 1T-2H MoS2 catalyst shows high photothermal catalytic lignocellulosic biomass-to-H2 transformation performance in polar wood chips, bamboo, rice straw corncobs, and rice hull aqueous solutions, and the highest H2 generation rate and solar-to-H2 (STH) efficiency respectively achieves 3661 µmol·h-1·g-1 and 0.18% in the polar wood chip system under 300 W Xe lamp illumination. This study provides a sustainable and cost-effective method for the direct transformation of renewable lignocellulosic biomass to H2 fuel driven by solar energy.

A Water-Soluble Highly Oxidizing Cobalt Molecular Catalyst Designed for Bioinspired Water Oxidation.

Herein, we present a stable water-soluble cobalt complex supported by a dianionic 2,2'-([2,2'-bipyridine]-6,6'-diyl)bis(propan-2-ol) ligand scaffold, which is a rare example of a high-oxidation species, as demonstrated by structural, spectroscopic and theoretical data. Electron paramagnetic resonance (EPR) spectroscopy and magnetic susceptibility measurements revealed that the CoIV center of the mononuclear complex in the solid state resides in the high spin state (sextet, S=5/2). The complex can effectively catalyze water oxidation via a single-site water nucleophilic attack pathway with an overpotential of only 360 mV in a phosphate buffer with a pH of 6. The key intermediate toward water oxidation was speculated based on theoretical calculations and was identified by in situ spectroelectrochemical experiments. The results are important regarding the accessibility of high-oxidation state metal species in synthetic models for achieving robust and reactive oxidation catalysis.

Accuracy of detecting residual disease after neoadjuvant chemoradiotherapy for esophageal squamous cell carcinoma (preSINO trial): a prospective multicenter diagnostic cohort study.

BACKGROUND: After neoadjuvant chemoradiotherapy (nCRT) for esophageal cancer, high pathologically complete response (pCR) rates are being achieved especially in patients with squamous cell carcinoma (SCC). An active surveillance strategy has been proposed for SCC patients with clinically complete response (cCR) after nCRT. To justify omitting surgical resection, patients with residual disease should be accurately identified. The aim of this study is to assess the accuracy of response evaluations after nCRT based on the preSANO trial, including positron emission tomography with computed tomography (PET-CT), endoscopy with bite-on-bite biopsies and endoscopic ultrasonography (EUS) with fine-needle aspiration (FNA) in patients with potentially curable esophageal SCC. METHODS: Operable esophageal SCC patients who are planned to undergo nCRT according to the CROSS regimen and are planned to undergo surgery will be recruited from four Asian centers. Four to 6 weeks after completion of nCRT, patients will undergo a first clinical response evaluation (CRE-1) consisting of endoscopy with bite-on-bite biopsies. In patients without histological evidence of residual tumor (i.e. without positive biopsies), surgery will be postponed another 6 weeks. A second clinical response evaluation (CRE-2) will be performed 10-12 weeks after completion of nCRT, consisting of PET-CT, endoscopy with bite-on-bite biopsies and EUS with FNA. Immediately after CRE-2 all patients without evidence of distant metastases will undergo esophagectomy. Results of CRE-1 and CRE-2 as well as results of the three single diagnostic modalities will be correlated to pathological response in the resection specimen (gold standard) for calculation of sensitivity, specificity, negative predictive value and positive predictive value. DISCUSSION: If the current study shows that major locoregional residual disease (> 10% residual carcinoma or any residual nodal disease) can be accurately (i.e. with sensitivity of 80.5%) detected in patients with esophageal SCC, a prospective trial will be conducted comparing active surveillance with standard esophagectomy in patients with a clinically complete response after nCRT (SINO trial). TRIAL REGISTRATION: The preSINO trial has been registered at ClinicalTrials.gov as NCT03937362 (May 3, 2019).

Polyoxometalate-Bridged Cu(I)- and Ag(I)-Thiacalix[4]arene Dimers for Heterogeneous Catalytic Oxidative Desulfurization and Azide-Alkyne "Click" Reaction.

Two remarkable polyoxometalate-bridged Cu(I)- and Ag(I)-thiacalix[4]arene dimers, namely, [Cu4(SiW12O40)(L)2(DMF)2]·2EtOH·DMF (1-Cu) and [Ag4(PMo12O40)(L)2]·OH (1-Ag), were prepared by using a new thiacalix[4]arene, metal cation and polyoxometalate (L = tetra[2-(ethylthio)-1-methyl-1H-imidazole]-thiacalix[4]arene). In 1-Cu and 1-Ag, two thiacalix[4]arenes were linked together by one [SiW12O40]4- or [PMo12O40]3- anion via two metal cations to give a molecular dimer. Further, adjacent dimers were extended into a high-dimensional supramolecular architecture through hydrogen bonds. Markedly, these molecular dimers are exceedingly stable in organic solvents and then were employed as efficient catalysts for catalytic oxidation desulfurization as well as the azide-alkyne "click" reaction.

Metal-complex chromophores for solar hydrogen generation.

Solar H2 generation from water has been intensively investigated as a clean method to convert solar energy into hydrogen fuel. During the past few decades, many studies have demonstrated that metal complexes can act as efficient photoactive materials for photocatalytic H2 production. Here, we review the recent progress in the application of metal-complex chromophores to solar-to-H2 conversion, including metal-complex photosensitizers and supramolecular photocatalysts. A brief overview of the fundamental principles of photocatalytic H2 production is given. Then, different metal-complex photosensitizers and supramolecular photocatalysts are introduced in detail, and the most important factors that strictly determine their photocatalytic performance are also discussed. Finally, we illustrate some challenges and opportunities for future research in this promising area.

High Body Mass Index Worsens Survival in Patients with Esophageal Squamous Cell Carcinoma after Esophagectomy.

AIMS: To investigate the prognostic significance of body mass index (BMI) on the survival of patients with esophageal squamous cell carcinoma (ESCC) after esophagectomy. METHODS: Between 2005 and 2008, 291 patients with ESCC who met the inclusion criteria were included in the study. The BMI cut-off values were as follows: 18.5-23 kg/m2 for normal weight; 23-27.5 kg/m2 for overweight; and ≥27.5 kg/m2 for those with obesity. Univariate and multivariate analyses were performed to identify prognostic factors for long-term survival. RESULTS: Patients were divided into 3 groups: normal weight (n = 138), overweight (n = 103), and obese (n = 50). The median survival time was 56 months. The 5-year overall survival (OS) rates were 40.8, 44.7, and 20.8% for normal weight, overweight, and obese patients respectively (p < 0.05). Multivariate analysis identified BMI as an independent prognostic factor for OS (p < 0.05). For 179 patients without lymph node metastasis, the 5-year OS rates were 46.5, 50.7, and 27.0% for normal weight, overweight, and obese patients respectively (p < 0.05). CONCLUSIONS: A BMI ≥27.5 kg/m2 has a distinctly adverse impact on the long-term survival of ESCC patients after esophagectomy. High BMI is a potential predictor of worse prognosis in ESCC patients, particularly in patients without lymph node metastasis.

Long-Term Survival After Surgical Treatment of Thymic Carcinoma: A Retrospective Analysis from the Chinese Alliance for Research of Thymoma Database.

BACKGROUND: Thymic carcinoma is a type of rare and highly malignant tumor that originates from the thymic epithelium. Treatment and prognosis of thymic carcinoma remain controversial. We retrospectively analyzed survival data from a large-sample multicenter database in China. METHODS: The Chinese Alliance for Research of Thymoma constructed a retrospective database of patients with thymic epithelial tumors, which enrolled 1930 patients from January 1996 to August 2013, including 329 with thymic carcinomas. In this study, we analyzed clinical, pathologic, and treatment information, measured long-term survival rates, and identified relevant prognostic factors. RESULTS: Of 329 patients, R0 resection was performed in 211 (57.7 %), R1 in 34 (9.2 %), and R2 in 84 (22.5 %).The 3-, 5-, and 10-year survival rates were 78.3, 67.1, and 47.9 %, respectively. In univariate analysis, early Masaoka-Koga stage, R0 resection, and postoperative radiotherapy were associated with better overall survival.Early Masaoka-Koga stage and postoperative radiotherapy were also associated with disease-free survival. In multivariate analyses, R0 resection, Masaoka-Koga stage, and postoperative radiotherapy were significant prognostic factors of survival. CONCLUSIONS: Complete resection is the preferred primary treatment for thymic carcinoma. R0 resection, early Masaoka-Koga stage, and postoperative radiotherapy are significant predictors of improved survival.

Energy Transfer in a Hybrid Ir(III) Carbene-Pt(II) Acetylide Assembly for Efficient Hydrogen Production.

A new heterometallic supramolecular complex, consisting of an iridium carbene-based unit appended to a platinum terpyridine acetylide unit, representing a new Ir(III) -Pt(II) structural motif, was designed and developed to act as an active species for photocatalytic hydrogen production. The results also suggested that a light-harvesting process is essential to realize the solar-to-fuel conversion in an artificial system as illustrated in the natural photosynthetic system.

A Noble-Metal-Free Nickel(II) Polypyridyl Catalyst for Visible-Light-Driven Hydrogen Production from Water.

The complex [Ni(bpy)3](2+) (bpy=2,2'-bipyridine) is an active catalyst for visible-light-driven H2 production from water when employed with [Ir(dfppy)2 (Hdcbpy)] [dfppy=2-(3,4-difluorophenyl)pyridine, Hdcbpy=4-carboxy-2,2'-bipyridine-4'-carboxylate] as the photosensitizer and triethanolamine as the sacrificial electron donor. The highest turnover number of 520 with respect to the nickel(II) catalyst is obtained in a 8:2 acetonitrile/water solution at pH 9. The H2 -evolution system is more stable after the addition of an extra free bpy ligand, owing to faster catalyst regeneration. The photocatalytic results demonstrate that the nickel(II) polypyridyl catalyst can act as a more effective catalyst than the commonly utilized [Co(bpy)3 ](2+). This study may offer a new paradigm for constructing simple and noble-metal-free catalysts for photocatalytic hydrogen production.

Changes in the recent three decades and survey on the current status of surgical treatment for esophageal cancer in China.

BACKGROUND: To review the changes and survey on status quo of the surgical treatment for esophageal cancer in China. The differences in diagnosis and treatment for esophageal cancer among hospitals in different regions across China were also investigated. METHODS: We sent questionnaires to 46 hospitals across China, investigating the volume of esophageal cancer surgeries, surgical procedures, and perioperative management under the guidance of esophageal surgery chiefs. RESULTS: A total of 46 questionnaires were sent out and collected. The survey results showed that in the past 5 years, the volume of surgeries for esophageal cancer remained stable by 23.9% of those hospitals, increased by 30.4%, and decreased by 45.7%. Of those patients treated by surgery, 19.1% were in the early stages, and 80.9% were in locally advanced stages. In terms of surgical procedures, 73.4% of the patients were treated by minimally invasive surgery and 85.7% of esophageal substitutes were a gastric conduit, 93.1% of the substitutes were pulled to the neck through the esophageal bed. For the lymph node dissection, 78.5% of the patients had a complete two-field lymph node dissection including the para-recurrent laryngeal nerve lymph nodes. Of the patients with neoadjuvant therapy, 53.5% received chemotherapy or chemotherapy plus immunotherapy (47.0%), and 43.5% had chemoradiation. CONCLUSIONS: Currently, in China, minimally invasive surgery-oriented multimodality treatment, including complete two-field lymph node dissection, has become the standard approach for esophageal cancer management. Over the past decade, this standardized approach has significantly improved prognosis compared to previous decades.

Obesity, adipokines and hepatocellular carcinoma.

Obesity is rapidly becoming pandemic and is associated with increased carcinogenesis, especially hepatocellular carcinoma (HCC). Adipose tissue is considered as an endocrine organ because of its capacity to secrete a variety of adipokines, such as leptin, adiponectin and resistin. Recently, adipokines have been demonstrated to be associated with kinds of chronic liver diseases including fibrosis, cirrhosis and carcinogenesis. Direct evidence is accumulating rapidly supporting the inhibitory and/or activating role of adipokines in the process of carcinogenesis and progression of human HCC. This review aims to provide important insight into the potential mechanisms of adipokines in the development of HCC.

Charge-neutral amidinate-containing iridium complexes capable of efficient photocatalytic water reduction.

Two new charge-neutral iridium complexes, [Ir(tfm-ppy)(2)(N,N'-diisopropyl-benzamidinate)] (1) and [Ir(tfm-ppy)(2)(N,N'-diisopropyl-4-diethylamino-3,5-dimethyl-benzamidinate)] (2) (tfm-ppy=4-trifluoromethyl-2-phenylpyridine) containing an amidinate ligand and two phenylpyridine ligands were designed and characterised. The photophysical properties, electrochemical behaviours and emission quenching properties of these species were investigated. In concert with the cobalt catalyst [Co(bpy)(3)](2+), members of this new class of iridium complexes enable the photocatalytic generation of hydrogen from mixed aqueous solutions via an oxidative quenching pathway and display long-term photostability under constant illumination over 72 h; one of these species achieved a relatively high turnover number of 1880 during this time period. In the case of complex 1, the three-component homogeneous photocatalytic system proved to be more efficient than a related system containing a charged complex, [Ir(tfm-ppy)(2)(dtb-bpy)](+) (3, dtb-bpy=4,4'-di-tert-butyl-2,2'-dipyridyl). In combination with a rhodium complex as a water reduction catalyst, the performances of the systems using both complexes were also evaluated, and these systems exhibited a more efficient catalytic propensity for water splitting than did the cobalt-based systems that have been studied previously.

Tricyclometalated iridium complexes as highly stable photosensitizers for light-induced hydrogen evolution.

The development of an efficient and stable artificial photosensitizer for visible-light-driven hydrogen production is highly desirable. Herein, a new series of charge-neutral, heteroleptic tricyclometalated iridium(III) complexes, [Ir(thpy)2(bt)] (1-4; thpy = 2,2'-thienylpyridine, bt = 2-phenylbenzothiazole and its derivatives), were systematically synthesized and their structural, photophysical, and electrochemical properties were established. Three solid-state structures were studied by X-ray crystallographic analysis. This design offers the unique opportunity to drive the metal-to-ligand charge-transfer (MLCT) band to longer wavelengths for these iridium complexes. We describe new molecular platforms that are based on these neutral iridium complexes for the production of hydrogen through visible-light-induced photocatalysis over an extended period of time in the presence of [Co(bpy)3](2+) and triethanolamine (TEOA). The maximum amount of hydrogen was obtained under constant irradiation over 72 h and the system could regenerate its activity upon the addition of cobalt-based catalysts when hydrogen evolution ceased. Our results demonstrated that the dissociation of the [Co(bpy)3](2+) catalyst contributed to the loss of catalytic activity and limited the long-term catalytic performance of the systems. The properties of the neutral complexes are compared in detail to those of two known non-neutral bpy-type complexes, [Ir(thpy)2(dtb-bpy)](+) (5) and [Ir(ppy)2(dtb-bpy)](+) (6; ppy = 2-phenylpyridine, dtb-bpy = 4,4'-di-tert-butyl-2,2'-dipyridyl). This work is expected to contribute toward the development of long-lasting solar hydrogen-production systems.

Extranodal metastasis is a powerful prognostic factor in patients with adenocarcinoma of the esophagogastric junction.

BACKGROUND AND OBJECTIVES: The purpose of this study is to estimate the effect of extranodal metastasis (EM) on recurrence and survival in patients with adenocarcinoma of the esophagogastric junction (AEG) after curative resection. METHODS: Clinical data from 284 node-positive AEG patients who underwent curative resection were reviewed. Univariate and multivariate analyses were conducted to elucidate the effect of EM on recurrence-free survival (RFS) and overall survival (OS). RESULTS: EM was detected in 70 (24.6%) of the 284 cases. It had a significant correlation with tumor size, Lauren type, histopathological grading, depth of tumor invasion, number of metastatic nodes, lymph node ratio, and TNM stage. The 5-year RFS and OS rates were 22.2% and 24.3%, respectively. Patients with EM had a significantly decreased RFS (16 vs. 36 months, P < 0.001) and OS (23 vs. 41 months, P < 0.001) compared with those without EM. Multivariate analyses identified EM as an independent prognostic factor (P = 0.003 and 0.001, respectively). CONCLUSION: The presence of EM increases recurrence probability and reduces OS probability of AEG patients with lymph node metastasis. EM is a powerful prognostic factor reflecting a particularly aggressive biological behavior. Better understanding of EM status can help clinicians with regard to treatment decision and prognosis evaluation.

[Risk factors of early recurrence and prognosis for patients with adenocarcinoma of gastroesophageal junction after curative resection].

OBJECTIVE: To investigate the risk factors for early recurrence of gastroesophageal junction adenocarcinoma (Siewert type II/III) after curative resection and the prognosis of these patients. METHODS: Retrospective analysis was performed for the 170 patients with recurrent AEG after curative resection in our hospital.Univariate and multivariate analysis were applied to investigate risk factors for early recurrence ( < 24 month), the prognosis of these patients were also analyzed. RESULTS: The rate of early recurrence of AEG after curative resection was 75.3%. Univariate analysis showed that tumor Borrmann type, invasive depth, lymph node metastasis, metastasis lymph node ratio (LNR) and TNM stage were significant factors associated with early recurrence after curative resection (P < 0.05). Multivariate analysis identified that only LNR and tumor invasive depth were independent risk factors for early recurrence (P < 0.05). The median disease free survival time (9, 20 months, P < 0.01), 5-year survival rate (2.4%, 12.6%, P < 0.01) and the median survival time after recurrence(5, 8 months, P = 0.004) between patients with high-LNR group and low-LNR group were significantly difference. CONCLUSIONS: LNR and tumor invasive depth were determined to be independent risk factors associate with early recurrence after curative resection for AEG. The patients with high-LNR have a poorer survival compared with those with low-LNR; For the patients with serosa invaded and high LNR should be closely followed up to detect recurrence and take effective treatment timely to improve patients outcomes.

[Analysis of the clinicopathologic characters and prognostic impact of extranodal metastasis in gastric cardia patients].

OBJECTIVE: To investigate the correlation between extranodal metastasis (EM) and clinicopathologic features as well as the effect of EM on the prognosis in gastric cardia patients. METHODS: Retrospective analysis was performed for the 323 cases with histologically proven adenocarcinoma of gastric cardia who underwent curative resection from January 2000 to January 2007. There were 272 male patients and 51 female patients with their median age of 63 (22 to 85) years. The relationship between clinicopathological features and extranodal metastasis was studied. The effects of the EM on the recurrence and survival of these patients were also analyzed. RESULTS: EM positive was detected in 67 (20.7%) of the 323 patients. The incidence of EM was correlated with tumor Lauren typing, differentiation degree, invasive depth and lymph node metastasis (χ(2) = 4.647-27.216, P < 0.05). The 5-year survival rate and media survival time between patients with EM and those without EM were 12.3%, 34.1% and 20, 39 months, there was a statistically significantly difference (χ(2) = 23.936, P = 0.000) in 5-year survival rate. Multivariate analysis identified that invasive depth, lymph node metustasis and EM as an independent prognostic factor of all the patients. To the last follow up, the cumulative probability of recurrence of EM-positive patients was significant higher than EM-negative patients (59.7% vs. 35.9%; χ(2) = 12.409, P = 0.000). To study furthermore, stratified analysis showed that, in the node-positive patients, the cumulative recurrence rate of EM-positive patients was higher than EM-negative patients (60.9% vs. 40.0%; χ(2) = 8.410, P = 0.004) and the 5-year survival rate of EM-positive patients was less than the EM-negative patients (12.9% vs. 30.1%; χ(2) = 12.939, P = 0.000), the differences were statistically significant. CONCLUSIONS: EM positive is determined to be an independent prognosis factor of gastric cardia after curative resection. EM-positive patients have a high risk for recurrence and a short time to live.

Impact of ligand modification on hydrogen photogeneration and light-harvesting applications using cyclometalated iridium complexes.

To explore structure-activity relationships with respect to light-harvesting behavior, a family of bis-cyclometalated iridium complexes [Ir(C^N)(2)(Hbpdc)] 2-5 (where C^N = 2-phenylbenzothiazole and its functionalized derivatives, and H(2)bpdc =2,2'-bipyridine-4,4'-dicarboxylate) was synthesized using a facile method. The photophysical and electrochemical properties of these complexes were investigated and compared to those of analogue 1 (C^N = (4-trifluoromethyl)-2-phenylbenzothiazole); they were also investigated theoretically using density functional theory. The molecular structures of complexes 2-4 were determined by X-ray crystallography, which revealed typical octahedral coordination geometry. The structural modifications involved in the complexes were accomplished through the attributes of electron-withdrawing CF(3) and electron-donating NMe(2) substituents. The UV-vis spectra of these species, except for that of 5, displayed a broad absorption in the low-energy region, which originated from metal-to-ligand charge-transfer transitions. These complexes were found to exhibit visible-light-induced hydrogen production and light-to-electricity conversion in photoelectrochemical cells. The yield of hydrogen production from water using these complexes was compared, which revealed substantial dependences on their structures, particularly on the substituent of the cyclometalated ligand. Among the systems, the highest turnover number of 1501 was achieved with complex 2, in which the electron-withdrawing CF(3) substituent was connected to a phenyl ring of the cyclometalated ligand. The carboxylate anchoring groups made the complexes highly suitable for grafting onto TiO(2) (P25) surfaces for efficient electron transfer and thus resulted in an enhancement of hydrogen evolution compared to the unattached homogeneous systems. In addition, the combined incorporation of the electron-donating NMe(2) group and the electron-withdrawing CF(3) substituent on the cyclometalated ligand caused complex 5 to not work well for hydrogen production. Their incorporation, however, enhanced the performance of 5 in the light-harvesting application in nanocrystalline TiO(2) dye-sensitized solar cells, which was attributed to the intense absorption in the visible region.

[Effect of HMGB1 on the VEGF-C expression and proliferation of esophageal squamous cancer cells].

OBJECTIVE: To explore the effect of HMGB1 on the VEGF-C expression and proliferation of esophageal squamous cancer cells as well as its possible mechanism. METHODS: A cassette encoding siRNA targeting HMGB1 mediated by rAAV was constructed, the rAAV-siHMGB1-hrGFP, and a vector encoding siRNA mismatching HMGB1 was constructed, the rAAV-miHMGB1-hrGFP. This experiment in vitro included three groups, namely, the blank control group (group A) of KYSE150 cells transfected by rAAV-hrGFP, negative mismatch control group (group B) of KYSE150 cells transfected with rAAV-miHMGB1-hrGFP, and RNA interference group (group C) of KYSE150 cells transfected with rAAV-siHMGB1-hrGFP. We examined the expression of HMGB1 mRNA and protein in the three group cells by real-time PCR and Western blot after 24 h and 48 h, respectively. Then, VEGF-C expression and cell proliferation in the three group cells with or without sRAGE, as an inhibitor of RAGE signal pathway, were assayed by ELISA and MTT after 24 h. RESULTS: The expression of HMGB1 mRNA and protein in KYSE150 cells in vitro in the group C transfected with rAAV-siHMGB1-hrGFP at the final concentration of 2×10(6) v.g/cell was significantly lower than that of the group A or B after 24 h and 48 h (P < 0.01). The VEGF-C expression of KYSE150 cells was (502.43 ± 13.10) pg/ml in the group C, significantly reduced in comparison with that of the group A (686.40 ± 10.94) pg/ml or group B (682.31 ± 9.61) pg/ml after 24 h (P < 0.05). At the same time, the proliferation of KYSE150 cells in the group C was significantly inhibited compared with that of groups A and B after 24 h (P < 0.01). Moreover, sRAGE at the final concentration of 0.2 µg/ml inhibited the VEGF-C expression and proliferation of KYSE150 cells compared with the corresponding group without sRAGE after 24 h (P < 0.01 or P < 0.05). However, there was no significant difference of the VEGF-C expression and proliferation of KYSE150 cells with sRAGE in the group C compared with that of cells with sRAGE of the group A or group B after 24 h (P > 0.05). CONCLUSIONS: In esophageal squamous cell carcinoma, HMGB1 can promote the VEGF-C expression and proliferation of the cancer cells through RAGE signal pathway, and HMGB1-RAGE may become a potential target for cell proliferation and lymph node metastasis of this cancer.

Association and prognostic significance of alpha-L-fucosidase-1 and matrix metalloproteinase 9 expression in esophageal squamous cell carcinoma.

BACKGROUND: Alpha-L-fucosidase-1 (FUCA1) has been demonstrated to play opposing regulatory roles in adenocarcinoma and non-adenocarcinoma. Moreover, recent studies reported that FUCA1 could decrease the invasion capability by downregulating matrix metalloproteinase 9 (MMP-9) expression. However, the potential role and prognostic significance of FUCA1 in esophageal squamous cell carcinoma (ESCC) have not yet been explored. AIM: To evaluate the status, association, and prognostic value of FUCA1 and MMP-9 expression in ESCC. METHODS: Patients who underwent esophagectomy for ESCC between January 1, 2014, and December 31, 2014 at Sun Yat-Sen University Cancer Center were enrolled. The expression status of FUCA1 and MMP-9 in cancerous tissues was detected using immunohistochemistry. In addition, the expression profiles of the FUCA1 and MMP-9 genes in non-metastatic ESCC were extracted from The Cancer Genome Atlas (TCGA) database. RESULTS: High expression of FUCA1 and MMP-9 was found in 90 patients (75.6%) and 62 patients (52.1%), respectively. In the high FUCA1 expression group, the constituent ratios of patients with stage III disease (61.1% vs 37.9%, P = 0.029), lymphatic invasion (62.2% vs 31.0%, P = 0.003), and high MMP-9 expression (60.0% vs 27.6%, P = 0.002) were significantly higher than those in the low FUCA1 expression group. In Kaplan-Meier univariate analysis, advanced tumor-node-metastasis stage (III, P = 0.001), positive regional lymph node metastasis (N+, P = 0.002), high FUCA1 expression (P = 0.001), and high MMP-9 expression (P = 0.002) were potential predictors of shorter overall survival (OS), which was similar to the results analyzed based on the TCGA database. Further Cox multivariate regression analyses still demonstrated that FUCA1 and MMP-9 expression levels were independent prognostic factors of OS [hazard ratio (HR): 0.484, 95% confidence interval (CI): 0.239-0.979; P = 0.044; and HR: 0.591, 95%CI: 0.359-0.973, P = 0.039, respectively]. CONCLUSION: FUCA1 cooperation with MMP-9 may have a major role in affecting the ESCC invasion and metastatic capability, and serve as a valuable prognostic biomarker in ESCC.

Iron-N-heterocyclic carbene complexes as efficient electrocatalysts for water oxidation under acidic conditions.

The development of stable, Earth-abundant, and high-activity molecular water oxidation catalysts under acidic and neutral conditions remains a great challenge. Here, the use of N-heterocyclic carbene (NHC)-based iron(III) complex 1 {[phenyl(tris(3-methylimidazol-1-ylidene))borate]2Fe(III)}+ as a catalyst for water oxidation under acidic and neutral conditions was investigated. Two iron(II) carbene complexes, 2 {[2,6-bis(3-methylimidazolium-1-yl)pyridine]2Fe}2+ and 3 {[2,6-bis(3-methylimidazolium-1-yl)pyridine-4-carboxylic acid]2Fe}2+, were also used for comparison. A series of experiments demonstrate that complex 1 has excellent performance in terms of both catalytic activity and stability. In addition, the faradaic efficiency and turnover frequency (TOF) reach 95.0% and 2.8 s-1, respectively. An overpotential of ca. 490 mV is obtained at pH 1.5. Density functional theory (DFT) calculations indicate that dehydrogenation is the potential-determining step (PDS) in water oxidation. Complex 1 has a lower free energy barrier in this process than 2 and 3. High-valent Fe species are further proven in 1 by spectroelectrochemical measurements, which are crucial in promoting water oxidation. This study is expected to contribute to the development of homogeneous water oxidation catalysis under acidic and neutral conditions.