Med23 deficiency reprograms the tumor microenvironment to promote lung tumorigenesis.

BACKGROUND: Lung cancer is the leading cause of cancer-related death worldwide. We previously found that Mediator complex subunit 23 (MED23) is important for the tumourigenicity of lung cancer cells with hyperactive Ras activity in vitro, although the in vivo function of MED23 in lung tumourigenesis remains to be explored. METHODS: In this study, we utilized well-characterized KrasG12D-driven non-small cell lung cancer mouse model to investigate the role of MED23 in lung cancer. The lung tumour progression was evaluated by H&E and IHC analysis. Western blotting and qRT-PCR assays were performed to detect changes in gene expression. Immune cells were analyzed by FACS technology. RNA-seq and reporter assays were conducted to explore the mechanism. RESULTS: We observed that lung epithelial Med23 deletion by adeno-Cre resulted in a significant increase in KrasG12D tumour number and size, which was further verified with another mouse model with Med23 specifically deleted in alveolar type II cells. Mice with lung-specific Med23 deficiency also exhibited accelerated tumourigenesis, and a higher proliferation rate for tumour cells, along with increased ERK phosphorylation. Notably, the numbers of infiltrating CD4+ T cells and CD8+ T cells were significantly reduced in the lungs of Med23-deficient mice, while the numbers of myeloid-derived suppressor cells (MDSCs) and Treg cells were significantly increased, suggesting the enhanced immune escape capability of the Med23-deficient lung tumours. Transcriptomic analysis revealed that the downregulated genes in Med23-deficient lung tumour tissues were associated with the immune response. Specifically, Med23 deficiency may compromise the MHC-I complex formation, partially through down-regulating B2m expression. CONCLUSIONS: Collectively, these findings revealed that MED23 may negatively regulate Kras-induced lung tumourigenesis in vivo, which would improve the precise classification of KRAS-mutant lung cancer patients and provide new insights for clinical interventions.

Safety and efficacy of self-expandable metallic stent combined with 125I brachytherapy for the treatment of malignant obstructive jaundice.

BACKGROUND: Several previous studies demonstrated that the combination of self-expandable metallic stents (SEMS) and 125I seed implantation might prolong stent patency and obtain survival benefits for malignant obstructive jaundice (MOJ) patients. However, these studies rarely mentioned a comparison between CT-guided intratumoral 125I seed implantation and intraluminal 125I seed strand insertion combined with stenting for the management of MOJ. This study aimed to further evaluate the safety and efficacy of SEMS combined with 125I brachytherapy in the management of unresectable MOJ. METHODS: Fifty-nine patients with unresectable MOJ were retrospectively included from March 2018 to June 2021. The main therapeutic outcomes were evaluated in terms of stent patency, and overall survival. Cumulative stent patency and overall survival rates were calculated by Kaplan-Meier survival analysis. Both clinical and treatment factors associated with survival were analyzed. RESULTS: Technical success was achieved in all patients. The clinical success rate was 94% (32/34) in the seeds group and 92% (23/25) in the control group, no significant difference was found (p =1.000). The median duration of stent patency was significantly longer in the 125I brachytherapy group compared with the control group (289 days vs. 88 days, respectively, p =0.001). The 125I brachytherapy group demonstrated a significantly better median overall survival rate than the control group (221 days vs. 78 days, respectively, p =0.001). In multivariate analysis, stents with 125I brachytherapy (p =0.004) was a significant favorable prognostic factor that affected patient survival. No significant difference was observed between CT-guided 125I seed implantation and 125I seed strand insertion in stent patency (p =0.268), and overall survival (p =0.483). CONCLUSION: SEMS combined with 125I brachytherapy is safe and effective for treating MOJ. 125I brachytherapy may help to maintain stent patency and prolong overall survival. There was no significant difference between CT-guided 125I seed implantation with SEMS and 125I seed strand insertion with SEMS in stent patency and overall survival.

CT-guided 125I brachytherapy for hepatocellular carcinoma in high-risk locations after transarterial chemoembolization combined with microwave ablation: a propensity score-matched study.

BACKGROUND: This study aimed to evaluate the safety and efficacy of 125I brachytherapy combined with transarterial chemoembolization (TACE) and microwave ablation (MWA) for unresectable hepatocellular carcinoma (HCC) in high-risk locations. PATIENTS AND METHODS: After 1:2 propensity score matching (PSM), this retrospectively study analyzed 49 patients who underwent TACE +MWA+125I brachytherapy (group A) and 98 patients who only received TACE +MWA (group B). The evaluated outcomes were progression-free survival (PFS), overall survival (OS), and treatment complications. Cox proportional hazards regression analysis survival was used to compare the two groups. RESULTS: The patients in group A showed a longer PFS than group B (7.9 vs. 3.3 months, P = 0.007). No significant differences were observed in median OS between the two groups (P = 0.928). The objective response rate (ORR), disease control rate of tumors in high-risk locations, and the ORR of intrahepatic tumors were 67.3%, 93.9%, and 51.0%, respectively, in group A, and 38.8%, 79.6% and 29.6%, respectively, in group B (P < 0.001, P = 0.025 and P = 0.011, respectively). TACE-MWA-125I (HR = 0.479, P < 0.001) was a significant favorable prognostic factor that affected PFS. The present of portal vein tumor thrombosis was an independent prognostic factor for PFS (HR = 1.625, P = 0.040). The Barcelona clinic liver cancer (BCLC) stage (BCLC C vs. B) was an independent factor affecting OS (HR = 1.941, P = 0.038). The incidence of complications was similar between the two groups, except that the incidence of abdominal pain was reduced in the group A (P = 0.007). CONCLUSIONS: TACE-MWA-125I resulted in longer PFS and better tumor control than did TACE-MWA in patients with unresectable hepatocellular carcinoma in high-risk locations.

Outcomes of two types of iodine-125 seed delivery with metal stents in treating malignant biliary obstruction: a systematic review and meta-analysis.

PURPOSE: To conduct a meta-analysis comparing the efficacy and safety of two types of iodine-125 (I-125) seed delivery with metal stents (the study group) versus conventional metal stents (the control group) in patients with malignant biliary obstruction (MBO). METHODS: Our team systematically searched the PubMed, Embase, and Cochrane Library databases for relevant studies published from January 2012 up to July 2021. Survival time and stent dysfunction were the primary measured outcomes. Subgroup analyses were conducted according to the type of I-125 seed delivery. RESULTS: Eleven studies, including 1057 patients in total, were pooled for stent dysfunction. The study group showed a lower risk of stent dysfunction than the control group [odds ratio (OR): 0.61, 95% confidence interval (CI) 0.46-0.81, P = 0.001]. The pooled results of six studies reporting overall survival (OS) showed that the study group had a better survival outcome than the control group [hazard ratio (HR): 0.34, 95% CI: 0.28-0.42, P < 0.001]. In the subgroup analyses, the I-125 seed stent group had significantly less stent dysfunction than the control group (OR: 0.49, 95% CI: 0.31-0.76, P = 0.002). Meanwhile, the metal stents + I-125 radioactive seed strand group showed significantly more improvement in OS than the control group (HR: 0.33, 95% CI: 0.26-0.42, P < 0.001). Moreover, our analysis suggests that using I-125 seeds did not result in increasing related adverse events compared with using metal stents alone (all P > 0.05). The study group was significantly superior to the control group, with better survival and decreased stent dysfunction. Meanwhile, the delivery of I-125 seeds did not increase adverse events. CONCLUSION: The delivery of I-125 with metal stents may be considered a preferable technique for MBO.

Effect of percutaneous stenting strategy of unresectable malignant hilar biliary obstruction by three-dimensional reconstruction volumetry.

PURPOSE: To explore clinical outcomes of percutaneous stent implantation using volumetric criteria for unresectable malignant hilar biliary obstruction (MHBO). Additionally, aimed to identify the predictors of patients' survival. METHODS: Seventy-two patients who were initially diagnosed with MHBO between January 2013 to December 2019 in our center were retrospectively included. Patients were stratified according to the drainage achieved ≥50%, <50% of the total liver volume. Patients were divided into two groups: Group A (≥50% drainage), and Group B (<50% drainage). The main outcomes were evaluated in terms of relief of jaundice, effective drainage rate, and survival. Related factors that affect survival were analyzed. RESULTS: 62.5% of the included patients reached effective biliary drainage. The successful drainage rate was significantly higher in Group B than in Group A (p < 0.001). The median overall survival (mOS) of included patients was 6.4 months. Patients who received drainage ≥50% of hepatic volume achieved longer mOS than those who received drainage <50% of hepatic volume (7.6 months vs. 3.9 months, respectively, p = 0. 011). Patients who received effective biliary drainage had longer mOS than those who received ineffective biliary drainage (10.8 months vs. 4.4 months, respectively, p < 0.001). Patients who received anticancer treatment had longer mOS than those who only received palliative therapy (8.7 months vs. 4.6 months, respectively, p = 0.014). In the multivariate analysis, KPS Score ≥ 80 (p = 0.037), ≥50% drainage achieved (p = 0.038), and effective biliary drainage (p = 0.036) were protective prognostic factors that affected patients' survival. CONCLUSION: Drainage achieved ≥50% of the total liver volume by percutaneous transhepatic biliary stenting seemed to have a higher effective drainage rate in MHBO patients. Effective biliary drainage may create chances for these patients to receive anticancer therapies that seem to provide survival benefits.

Effect of Biliary Tract Invasion with Obstructive Jaundice on the Prognosis of Patients With Unresectable Hepatocellular Carcinoma.

RATIONALE AND OBJECTIVES: Biliary tract invasion (BTI) is associated with poor outcomes in patients with hepatocellular carcinoma (HCC). However, the presence of a BTI is a neglected variable for staging in the current guidelines. This study aimed to explore the effects of BTI with obstructive jaundice on the prognosis of patients with unresectable HCC. METHODS: We retrospectively included 205 patients initially diagnosed with unresectable HCC who presented with obstructive jaundice due to BTI between January 2010 and June 2021. BTI was classified into four types according to the location of the biliary obstruction. Both clinical and treatment factors that affect median overall survival (mOS) were analyzed. RESULTS: The mOS of patients with Barcelona Clinic Liver Cancer (BCLC) stages B, C, and D was 9.2 months, 3.4 months, and 1.8 months, respectively (p<.001). The mOS of BTI type I patients was superior to that of BTI type II patients (7.1 months vs. 3.2 months, p=.002). Patients who underwent successful biliary drainage had a longer mOS than those who underwent unsuccessful biliary drainage (10.4 months vs. 2.9 months, p<.001). In the multivariate analysis, BTI type I (p=.009), successful biliary drainage (p=.005), and HCC treatment (p<.001) were significant favorable prognostic factors that affected patient survival. CONCLUSION: HCC patients with BTI type II may have a poorer prognosis than those with BTI type I. Effective biliary drainage and anti-cancer treatment may provide survival benefits to these patients. A more detailed staging system for HCC based on the state of BTI is needed.

Sevoflurane reverses cisplatin resistance in neuroblastoma cells through the linc00473/miR-490-5p/AKT1 axis.

OBJECTIVES: To determine whether sevoflurane regulates cisplatin resistance in neuroblastoma cells. METHODS: The SH-SY5Y cell line with cisplatin-resistant phenotype (SH-SY5Y-SR) was generated. Cells were co-treated with sevoflurane and cisplatin to seek the sevoflurane function on cisplatin resistance. Key targets of sevoflurane treatment were determined using sequencing (ribonucleic acid [RNA-seq]). Cells were then transfected with specific vectors. Linc00473 and microRNA-490-5p (miR-490-5p) levels were detected using reverse transcriptase quantitative real-time reverse transcription PCR (RT-qPCR). Linc00473-miR-490-5p binding was confirmed using a luciferase reporter-gene assay. After treatment, cell proliferation, viability, and caspase-3 activity were measured to determine the effects of treatment on tumor cells. Each experimental result is based on three independent experiments. RESULTS: Co-treatment with sevoflurane and cisplatin markedly improved the sensitivity of SH-SY5Y-SR cells to cisplatin, which inhibited the occurrence of cisplatin resistance. The RNA-sequencing analysis and RT-qPCR showed that sevoflurane inhibited linc00473 expression. Overexpression of linc00473 promoted cell proliferation, inhibited apoptosis, and promoted cisplatin resistance. The linc00473/miR-490-5p/V-akt murine thymoma viral oncogene homolog 1 (AKT1) axis was found to mediate the regulatory effects of sevoflurane on cisplatin resistance. CONCLUSION: Sevoflurane has great clinical potential against cisplatin-resistant tumors. Further animal experiments and clinical trials are required to achieve this goal.

Improve the Interfacial Properties between Poly(arylene sulfide sulfone) and Carbon Fiber by Double Polymeric Grafted Layers Designed on a Carbon Fiber Surface.

Double polymeric grafted layer is constructed by two steps of chemical reaction, in which two polymers had been used, respectively polydopamine (PDA) film and modified PASS (NH2-PASS) resin containing amine group, as the interphase in carbon fiber reinforced poly(arylene sulfide sulfone) (PASS) composite (CF/PASS) to work on enhancing the interfacial property. All the test results of chemical components and chemical structures on the carbon fiber surface show that the double polymeric grafted layer was constructed successfully with PDA and NH2-PASS chains. And obvious characteristics of thin PDA film and a polymer layer can be clearly seen in the morphology of modified carbon fiber. In addition to this, the obvious interphase and change in the thickness of interphase have been observed in the modulus distribution images of CF/PASS. The final superb performance is achieved by PASS composites with a double polymeric grafted layer, 27.2% and 198.6% superior to the original PASS composite for IFSS and ILSS, respectively. Moreover, the result also indicates that constructing a double polymeric grafted layer on a carbon fiber surface is a promising technique to modify carbon fiber for processing high-performance advanced thermoplastic composites and is more environmental friendly as well as convenient.

High Capacitive Antimonene/CNT/PANI Free-Standing Electrodes for Flexible Supercapacitor Engaged with Self-Healing Function.

In virtue of the high electrochemical activity and inherent flexibility, polyaniline (PANI) is an ideal electrode material for flexible supercapacitors (SCs). However, in practical applications, the inevitable agglomeration of PANI leads to low capacitance, poor rate performance, and cycling stability. Here, antimonene (Sb) nanosheets with ultrathin thickness, excellent mechanical strength, and flexibility are introduced into the carbon nanotube (CNT) framework for PANI electrodeposition via simple vacuum filtration, which enables the continuous and uniform growth of PANI. The resultant free-standing Sb/CNT/PANI electrode can thus exhibit a high specific capacitance of 578.57 F g-1 together with a high rate capability. Besides, thanks to the introduction of Sb nanosheets, the agglomeration of PANI during the electrodeposition is improved, which correspondingly alleviates the structural deterioration of PANI during repeated charge/discharge. Thus, the flexible SC assembled by Sb/CNT/PANI electrodes demonstrates both an impressive specific capacitance of 416 F g-1 and outstanding cycling stability over 12 000 cycles. Moreover, this SC device can have a practical self-healing function by employing self-healable polyurethane. The facile strategy reported herein sheds light on the design of high-performance flexible SCs, catering to the needs of portable and wearable electronics.

Studies on transmittance modulation and ions transfer kinetic based on capacitive-controlled 2D V2O5inverse opal film for electrochromic energy storage application.

Two-dimensional vanadium pentoxide inverse opal (2D V2O5IO) architecture was fabricated by polystyrene (PS) sphere template assisted electrodeposition process. In comparison to the un-templated V2O5film, the 2D V2O5IO film exhibited a highly ordered hexagonal close-packed bowel-like array, as well as noticeable electrochromism, such as transmittance modulation up to 42.6% at 800 nm, high coloration efficiency (28.6 cm2 · C-1), fast ions transfer kinetic (tb = 7.2 s,tc = 2.5 s). These improvements of electrochromic performance were attributed to the ordered morphology with larger surface areas, which considerably shortened the ions diffusion paths and accelerated ions migration. An electrochromic energy storage device assembled from the 2D V2O5IO film with simultaneous electrochromic and pseudocapacitive performance could not only show transmittance modulation accompanied by multicolor variations but also powered an LCD screen and an LED bulb, demonstrating a promising potential for practical applications.

Efficient Na+-storage in a Li4Ti5O12 anode to expand the voltage-window for full SIBs of high energy density.

The stable storage of sodium ions always presents some difficulties for sodium-based dual-ion batteries (S-DIBs), such as the irreversibility of guest-storage and kinetic hindrance in the anode. Based on the low strain volume and stable phase structure, herein, lithium titanate (LTO, Li4Ti5O12) was developed to store sodium ions between the working potential (∼0.8 V), which expands the lower plateau over than that of lithium ion storage (∼1.55 V) to obtain a high energy density of full batteries. The spinel lithium titanate shows negligible volume change and extremely stable structure under Na+-storage, which completely overcomes the shortage problems of the Na+-host. Additionally, by the detection of the transfer state of anions and cations in dual-ion batteries, the diffusion coefficient of the sodium ion in the LTO electrode is higher than that of the cathode, which shows that the transport process of sodium ions can meet the kinetic demands of full batteries. Such S-DIBs exhibit a large working voltage of 2.0-4.6 V and stable electrochemical performance over 1280 cycles, which is superior to conventional sodium-based systems, and further exhibit many advantages such as high energy density, environmental friendliness, and low cost.

Selective Catalytic Oxidation of Benzyl Alcohol to Benzaldehyde by Nitrates.

In this paper, ferric nitrate was used to oxidize benzyl alcohol in a mild condition and demonstrated its better performance compared to HNO3. In the reaction, the conversion rate and product selectivity could be both as high as 95% in N2 atmosphere, while the benzaldehyde yield also reached 85% in air. Similar to Fe(NO3)3·9H2O, the other metallic nitrates such as Al(NO3)3·9H2O and Cu(NO3)2·3H2O could also oxidize the benzyl alcohol with high activity. The applicability of Fe(NO3)3·9H2O for other benzylic alcohol was also investigated, and the reaction condition was optimized at the same time. The results showed the Fe(NO3)3·9H2O would be more conducive in oxidizing benzyl alcohol under the anaerobic condition. The experiments in N2 or O2 atmospheres were conducted separately to study the catalytic mechanism of Fe(NO3)3. The results showed the co-existence of Fe3+ and NO 3 - will generate high activity, while either was with negligible oxidation property. The cyclic transformation of Fe3+ and Fe2+ provided the catalytic action to the benzyl alcohol oxidation. The role of NO 3 - was also an oxidant, by providing HNO2 in anaerobic condition, while NO 3 - would be regenerated from NO in aerobic condition. O2 did not oxidize the benzyl alcohol conversion directly, while it could still be beneficial to the procedure by eliminating the unwelcome NO and simultaneously reinforcing the circulation of Fe2+ and Fe3+, which therefore forms a green cyclic oxidation. Hence, the benzyl alcohol oxidation was suggested in an air atmosphere for efficiency and the need of green synthesis.

Intrinsic acid resistance and high removal performance from the incorporation of nickel nanoparticles into nitrogen doped tubular carbons for environmental remediation.

Nitrogen doped tubular magnetic carbons embedded with nickel nanoparticles (Ni@NTMCs) were prepared via a simple pyrolysis process and employed as the effective adsorbents for the Cr(VI) removal. Ni@NTMCs with as high as 10.63 at.% N doping exhibited the excellent Cr(VI) removal capacities of 24.4 and 250 mg g-1 in neutral and acidic solution, respectively. Adsorption kinetics and isotherm study revealed that the monolayer chemical adsorption was the rate-controlling step for the Cr(VI) removal. The high removal performance can be ascribed to the combination of adsorption and reduction reaction between Cr(VI) ions, and Ni nanoparticles. N dopant and edge carbons acted as the Cr(VI) adsorption site. The surface Ni nanoparticles mainly made contributions to the reduction process. The embedded Ni nanoparticles steadily provided magnetism for the separation and helpful for the recycles stability, showing a high acid corrosion resistance in this study.

Percutaneous intratumoral injection of gemcitabine plus cisplatin mixed with fibrin glue for advanced pancreatic carcinoma: Case Report.

RATIONALE: The aim of this study was to determine the effectiveness of intratumoral injection of chemotherapeutics in improving the quality of life and survival of patients with pancreatic carcinoma. PATIENT CONCERNS: We present a case series of 5 patients with unresectable pancreatic adenocarcinoma. DIAGNOSES: Patients diagnosed with unresectable poorly differentiated pancreatic ductal adenocarcinoma by intraoperative frozen biopsyor percutaneous biopsy. INTERVENTIONS: Five patients with unresectable pancreatic adenocarcinoma received a computed tomography-guided percutaneous intratumoral injection of gemcitabine plus cisplatin mixed with fibrin glue. OUTCOMES: Mean overall survival was 16.2 ±â€Š3.7 months. Local control rates were 100% and 80% at postoperative 3 and 6 months, respectively. Mean Visual Analogue Scale pain score decreased from 7.2 ±â€Š.84 preoperatively to 2 ±â€Š1.22 at postoperative 4 weeks. There were no complications associated with the procedure. LESSONS: Percutaneous intratumoral injection of gemcitabine plus cisplatin mixed with fibrin glue for advanced pancreatic may be safe and effective.

Design, synthesis, and biological evaluation of novel quinazolinyl-diaryl urea derivatives as potential anticancer agents.

Through a structure-based molecular hybridization approach, a series of novel quinazolinyl-diaryl urea derivatives were designed, synthesized, and screened for their in vitro antiproliferative activities against three cancer cell lines (HepG2, MGC-803, and A549). Six compounds (7 g, 7 m, 7 o, 8 e, 8 g, and 8 m) showed stronger activity against a certain cell line compared with the positive reference drugs sorafenib and gefitinib. Among the six compounds, 8 g exhibited the strongest activity. In particular, compound 8 g induced A549 apoptosis, arrested cell cycle at the G0/G1 phase, elevated intracellular reactive oxygen species level, and decreased mitochondrial membrane potential. This compound can also effectively regulate the expression of apoptosis- and cell cycle-related proteins, and influence the Raf/MEK/ERK pathway. Molecular docking and structure-activity relationship analyses revealed that it can bind well to the active site of the receptor c-Raf, which was consistent with the biological data. Therefore, compound 8 g may be a potent antitumor agent, representing a promising lead for further optimization.

Synthesis, Fluorescence Properties, and Antiproliferative Potential of Several 3-Oxo-3H-benzo[f]chromene-2-carboxylic Acid Derivatives.

In this study, two series of 3-oxo-3H-benzo[f]chromene-2-carboxylic acid derivatives (compounds 5a-i and 6a-g) were synthesized. Their in vitro proliferation inhibitory activities against the A549 and NCI-H460 human non-small cell lung cancer (NSCLC) cell lines were evaluated. Their photophysical properties were measured. Among these target compounds, 5e exhibited the strongest antiproliferative activity by inducing apoptosis, arresting cell cycle, and elevating intracellular reactive oxygen species (ROS) level, suggesting that it may be a potent antitumor agent. In addition, compound 6g with very low cytotoxicity, demonstrated excellent fluorescence properties, which could be used as an effective fluorescence probe for biological imaging.

Preparation of halloysite nanotube-supported gold nanocomposite for solvent-free oxidation of benzyl alcohol.

Gold nanoparticles supported on halloysite nanotubes (Au/HNTs) were prepared by a homogeneous deposition-precipitation method. The specific characteristics of the catalyst were characterized in detail, in relation to their performance for solvent-free oxidation of benzyl alcohol. The particular structure of the catalyst resulted in high catalytic activity and stability compared with other supported gold catalysts. The enhanced catalytic activity of the Au/HNTs catalyst was mainly attributed to the presence of a higher amount of oxidized gold species and the tubular structure of the HNTs.

A microalgae residue based carbon solid acid catalyst for biodiesel production.

Biodiesel production from microalgae is recognized as one of the best solutions to deal with the energy crisis issues. However, after the oil extraction from the microalgae, the microalgae residue was generally discarded or burned. Here a novel carbon-based solid acid catalyst derived from microalgae residue by in situ hydrothermal partially carbonization were synthesized. The obtained catalyst was characterized and subjected to both the esterification of oleic acid and transesterification of triglyceride to produce biodiesel. The catalyst showed high catalytic activity and can be regenerated while its activity can be well maintained after five cycles.

4-Dimethyl-amino-N'-(4-nitro-benzyl-idene)benzohydrazide methanol monosolvate.

In the title compound, C(16)H(16)N(4)O(3)·CH(3)OH, the aromatic rings form a dihedral angle of 0.4 (2)°. The nitro group is twisted from the attached benzene ring by 7.5 (2)°. In the crystal, N-H⋯O and O-H⋯O hydrogen bonds link alternating hydrazone and methanol mol-ecules into chains in [100]. The crystal packing exhibits π-π inter-actions between aromatic rings from neighbouring chains [centroid-centroid distances = 3.734 (3) and 3.903 (3) Å].

Room temperature synthesis of a novel gamma-MnO2 hollow structure for aerobic oxidation of benzyl alcohol.

A novel gamma-MnO(2) hollow structure has been synthesized at room temperature using a simple chemical reaction between MnSO(4) and KMnO(4) in aqueous solution without using any templates, surfactants, catalysts, calcination and hydrothermal processes. The synthesized gamma-MnO(2) hollow structure was characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and BET analysis. It was found that the hollow structure consisting of short gamma-MnO(2) nanorods with diameters of 5-10 nm and lengths of 50-100 nm could form when the MnSO(4)/KMnO(4) mole ratio was equal to or larger than 2.3. The excess amount of Mn(2+) in solution was observed to promote the crystallization of gamma-MnO(2) nanorods and the formation of the gamma-MnO(2) hollow structure. In addition, the evolution of microstructure and morphology of the products obtained with a MnSO(4)/KMnO(4) mole ratio of 2.3 at different reaction times revealed that the hollow structure was formed via an Ostward ripening process. Furthermore, the obtained gamma-MnO(2) hollow structure was found to exhibit a better catalytic performance than conventional gamma-MnO(2) in the aerobic oxidation of benzyl alcohol to benzaldehyde, demonstrating its possible application in alcohol oxidation.