Realizing the high loading amount of active Cu on Al2O3 to boost its CO catalytic oxidation.

Catalytic oxidation of carbon monoxide (CO) by Cu/Al2O3 has garnered increasing interest in recent years due to its promising application prospects. Numerous investigations conducted on the Cu/Al2O3 system, but its catalytic performance for CO oxidation is still not as promising as that of precious metal catalysts. Increasing the loading amount of the active Cu on Al2O3 surface is a feasible method for improving its activity. However, with the increase of Cu loading, the agglomeration and enlargement of Cu particles is inevitable, which reduces the active Cu amount. Therefore, the utilization rate of Cu atoms is not high and the catalytic performance often can not further rise. Enhancing active Cu loading amount as high as possible is a prerequisite to further enlarge the activity of Cu/Al2O3 catalyst. Herein, self-synthesized Al2O3 nanofibers (Al2O3-nf) with high specific surface area and abundant penta-coordinated aluminum (AlV) are used as the support to maximize the Cu loading amount by chemical vapor deposition (CVD). And commercially available α-Al2O3 is used for comparative experiment. The high specific surface area could make Cu high dispersion on Al2O3, even at 20 wt% Cu loads, which is beneficial to high concentration load of active Cu. The catalytic activity of Cu/Al2O3-nf-CVD gradually increases with the increase of Cu loading from 2 wt% to 20 wt%, exhibiting a clear linear correlation with the surface content of Cu0 on the catalyst. Meanwhile, this result confirms that Cu0 plays a crucial role in CO oxidation of Cu/Al2O3. However, commercial α-Al2O3 reaches its highest activity when the Cu load is 5%, and then its activity begins to decrease due to the agglomeration of particles. Moreover, Cu/Al2O3-nf-CVD also exhibits remarkable thermal stability for CO oxidation. This work highlights a new strategy to synthesis of high Cu loading amount, high activity and thermostable Cu/Al2O3 catalyst for low-temperature oxidation of CO.

The efficient uptake of uranium by amine-functionalized ß-cyclodextrin supported fly ash composite from polluted water.

A novel polyethyleneimine/polydopamine-functionalized ß-cyclodextrin supported fly ash adsorbent (PEI/PDA/ß-CD/FA) had been synthesized to uptake uranium from polluted water. At pH = 5.0 and T = 298 K, the uranium uptake efficiency and capacity of PEI/PDA/ß-CD/FA reached to 98.7 % and 622.8 mg/g, respectively, which were much higher than those of FA (71.4 % and 206.7 mg/g).The excellent uranium uptake properties of PEI/PDA/ß-CD/FA could be explained by three points: (1) using ß-CD as a supporting material could effectively avoid the aggregation of FA and improve the hydrophily of FA; (2) the unique cavity structure of ß-CD could form chelates with uranyl ions; (3) the formation of PEI/PDA co-deposition coating on FA further enhanced the affinity of FA to UO22+. With the presence of interfering ions, the uptake efficiency of PEI/PDA/ß-CD/FA for uranium was still up to 94.5 % after five cycles, indicating the high selectively and recoverability of PEI/PDA/ß-CD/FA. In terms of the results of characterizations, uranium was captured by PEI/PDA/ß-CD/FA via electrostatic attraction, hydrogen bond, coordination and complexation. To sum up, PEI/PDA/ß-CD/FA was expected to be used for actual sewage treatment owing to its excellent uranium uptake efficiency/capacity, selectivity, cycle stability and feasibility of actual application.

Luminescence of Mn4+ in a Zero-Dimensional Organic-Inorganic Hybrid Phosphor [N(CH3)4]2ZrF6 for Dual-Mode Temperature Sensing.

Searching for new low-dimensional organic-inorganic hybrid phosphors is of great significance due to their unique optical properties and wide applications in the optoelectronic field. In this work, we report a Mn4+ doped zero-dimensional organic-inorganic hybrid phosphor [N(CH3)4]2ZrF6, which was synthesized by a wet chemical method. The crystal structure, thermal stability, and optical properties were systemically investigated by means of XRD, SEM, TG-DTA, FTIR, DRS, emission spectra, excitation spectra, as well as decay curves. Narrow red emission with high color purity can be observed from [N(CH3)4]2ZrF6:Mn4+ phosphor, which maintains effective emission intensity even at room temperature, indicating its potential practical application in WLEDs. In the temperature range of 13-295 K, anti-Stokes and Stokes sidebands of Mn4+ ions exhibit different temperature responses. By applying the emission intensity ratio of anti-Stokes vs. Stokes sidebands as temperature readout, an optical thermometer with a maximum absolute sensitivity of 2.13% K-1 and relative sensitivity of 2.47% K-1 can be obtained. Meanwhile, the lifetime Mn4+ ions can also be used for temperature sensing with a maximum relative sensitivity of 0.41% K-1, demonstrating its potential application in optical thermometry.

A Water-Stable Zn-MOF Used as Multiresponsive Luminescent Probe for Sensing Fe3+/Cu2+, Trinitrophenol and Colchicine in Aqueous Medium.

A water-stable Zn-MOF was constructed based on H2PBA and 1, 10-phenanthroline under solvothermal conditions. The compound exhibited a 3D (2,3,8)-connected (43)2(46.66.815.12)(8) topology framework. The crystal structure and phase purity of the compound was verified by single crystal X-ray diffraction. Subsequently, some studies on the morphology, structure, and luminescent properties were carried out. The results showed that this compound could be used as a versatile chemosensor for Fe3+/Cu2+, trinitrophenol and colchicine via a luminescence quenching effect in an aqueous medium.

A Multifunctional 3D Supermolecular Co Coordination Polymer With Potential for CO2 Adsorption, Antibacterial Activity, and Selective Sensing of Fe3+/Cr3+ Ions and TNP.

A 3D supermolecular structure [Co3(L)2 (2,2'-bipy)2](DMF)3(H2O)3 1) (H3L = 4,4',4″-nitrilotribenzoic acid) has been constructed based on H3L, and 2,2'-bipy ligands under solvothermal conditions. Compound 1 can be described as a (3, 6)-connected kgd topology with a Schläfli symbol (43)2(46.66.83) formed by [Co3(CO2)6] secondary building units. The adsorption properties of the activated sample 1a has been studied; the result shows that 1a has a high adsorption ability: the CO2 uptakes were 74 cm3·g-1 at 273 K, 50 cm3·g-1 at 298 K, the isosteric heat of adsorption (Qst) is 25.5 kJ mol-1 at zero loading, and the N2 adsorption at 77 K, 1 bar is 307 cm3 g-1. Magnetic measurements showed the existence of an antiferromagnetic exchange interaction in compound 1, besides compound 1 exhibits effective luminescent performance for Fe3+/Cr3+ and TNP.

Efficacy of small-volume simethicone given at least 30 min before gastroscopy.

AIM: To evaluate the efficacy of 5 mL simethicone solution in decreasing gastric foam if given at least 30 min before gastroscopy. METHODS: This was a randomized, placebo controlled, endoscopist blinded study performed at Changi General Hospital. Patients were at least 21 years old, had no prior surgical resection of the upper gastrointestinal tract, and scheduled for elective diagnostic gastroscopies. The primary outcome was the total mucosal visibility score (TMVS) which was evaluated using McNally score. The sample size was calculated to be 24 per group (SD 2.4, 80% power, P < 0.05, 2-sample t test). RESULTS: Fifty-four patients were randomised to receive either simethicone [1 mL liquid simethicone (100 mg) in 5 mL of water] or placebo (5 mL of water) at least 30 min before their gastroscopy. Six accredited consultants conducted the gastroscopy, and the interobserver agreement of scoring TMVS was good with a Kappa statistic of 0.73. The simethicone group had significantly better mean TMVS compared to placebo (5.78 ± SD 1.65 vs 8.89 ± SD 1.97, P < 0.001). The improvement was statistically significant for the duodenum and the gastric antrum, angularis, body, and fundus. Percent 51.9 of patients in the simethicone group had a TMVS of 4 (no bubbles at all) to 5 (only 1 area with minimal bubbles), while in the placebo group 3.7% of patients had TMVS of 4 or 5. The number needed to treat was 2.1 to avoid a TMVS of 6 and more. The simethicone group also had a significantly shorter procedure time with less volume of additional flushes required during gastroscopy to clear away obscuring gastric foam. CONCLUSION: With a premedication time of at least 30 min, 5 mL simethicone can significantly decrease gastric foam, decrease the volume of additional flushes, and shorten gastroscopy time.

Comparative study of strategies for preventing post-ERCP pancreatitis after early precut sphincterotomy for biliary access.

OBJECTIVE: Needle knife precut sphincterotomy (PS) during endoscopic retrograde cholangiopancreatography (ERCP) has been associated with a high risk of post-ERCP pancreatitis (PEP). This study aimed to examine the effect of no prophylaxis, somatostatin, rectal diclofenac and pancreatic duct (PD) stenting in reducing rates of PEP in patients who underwent early PS. METHODS: This was a retrospective comparative study and the study period was from January 2006 to December 2015. A standardized approach to early PS was used: (i) inadvertent guidewire cannulation of the PD > thrice; (ii) impacted bile duct stone; (iii) inability to achieve deep cannulation within 10 min. PEP prophylactic measures included: (i) none when there was minimal papilla trauma; (ii) somatostatin infusion; (iii) rectal diclofenac; (iv) PD stent. The difference in rates of PEP between the different strategies was analysed. RESULTS: During the study period, PS was performed in 191 ERCP patients (mean age 66 years; 56.5% males). The ERCP success rate after PS was 93.2% (178/191). Overall the PEP rate was 3.1% (6/191) and the severity in all cases was mild. PEP occurred in 6.1% of patients with PD cannulation but not in those without (P = 0.016). PEP rates were 1.8%, 7.3%, 1.8% and 0% in control, somatostatin, diclofenac and PD stenting groups, respectively (P = 0.209). CONCLUSIONS: There was no significant difference in PEP rates after early PS whether or not prophylactic measures were adopted if there was minimal papilla trauma. A trend towards lower PEP rates was observed in patients who had either rectal diclofenac or PD stenting, compared to somatostatin.

Enhanced Electrocatalytic Activity for Water Splitting on NiO/Ni/Carbon Fiber Paper.

Large-scale growth of low-cost, efficient, and durable non-noble metal-based electrocatalysts for water splitting is crucial for future renewable energy systems. Atomic layer deposition (ALD) provides a promising route for depositing uniform thin coatings of electrocatalysts, which are useful in many technologies, including the splitting of water. In this communication, we report the growth of a NiO/Ni catalyst directly on carbon fiber paper by atomic layer deposition and report subsequent reduction and oxidation annealing treatments. The 10-20 nm NiO/Ni nanoparticle catalysts can reach a current density of 10 mA·cm-2 at an overpotential of 189 mV for hydrogen evolution reactions and 257 mV for oxygen evolution reactions with high stability. We further successfully achieved a water splitting current density of 10 mA·cm-2 at 1.78 V using a typical NiO/Ni coated carbon fiber paper two-electrode setup. The results suggest that nanoparticulate NiO/Ni is an active, stable, and noble-metal-free electrocatalyst, which facilitates a method for future water splitting applications.

Carotid artery inflammation associated with gemcitabine-based therapy: a special report.

Vasculitis is an inflammation that can present as acute or chronic in nature, which causes changes in the walls of blood vessels, including thickening, weakening, narrowing and scarring. Gemcitabine, an antimetabolite chemotherapeutic agent, is generally well tolerated with a favorable side effect profile. However, there is increasing evidence that it is associated with vasculitis, which can affect small and large vessels. In this case report, we report a patient who has experienced fever with severe tenderness over right carotid artery, which occurred on the fifth day after the administration of gemcitabine. The exact mechanism of gemcitabine-induced vasculitis is unknown but cessation of gemcitabine and initiation of anti-inflammatory treatment appears to aid in the resolution of the clinical syndrome.

Ten-day triple therapy versus sequential therapy versus concomitant therapy as first-line treatment for Helicobacter pylori infection.

BACKGROUND AND AIM: Clarithromycin-based triple therapy (TT) is the first-line treatment for Helicobacter pylori infection in Singapore. There is awareness that TT may no longer be effective due to increased clarithromycin resistance rates. Sequential therapy (ST) and concomitant therapy (CT) are alternative treatment regimens. This study aimed to compare the efficacy of 10-day TT, ST, and CT as first-line treatment for H. pylori infection. METHODS: A randomized study conducted in a teaching hospital. Patients aged 21 years and older with newly diagnosed H. pylori infection were randomized to 10-day TT, ST, or CT. Treatment outcome was assessed by 13-carbon urea breath test at least 4 weeks after therapy. Intention to treat (ITT), modified ITT (MITT), and per protocol (PP) analyses of the eradication rates were performed. RESULTS: A total of 462 patients were enrolled (ST: 154; TT 155; CT 153). Patient demographics were similar. Eradication rates for ST versus TT versus CT: ITT analysis: 84.4% versus 83.2% versus 81.7% (P = not significant [NS]); MITT analysis: 90.3% versus 92.1% versus 94.7% (P = NS); PP analysis: 94.1% versus 92.8% versus 95.4% (P = NS). Antibiotic resistance rates for amoxicillin, clarithromycin, and metronidazole were 4.7%, 17.9%, and 48.1%, respectively. Dual clarithromycin and metronidazole resistance occurred in 7.5%. Dual resistance and lack of compliance were predictors of treatment failure. CONCLUSIONS: TT, ST, and CT all achieved eradication rates above 80% on ITT and above 90% on MITT and PP analyses. Dual resistance and lack of compliance were predictors of treatment failure (clinicaltrials.gov: NCT02092506).

Second and third line treatment options for Helicobacter pylori eradication.

Helicobacter pylori is a highly successful bacterium with a high global prevalence and the infection carries significant disease burden. It is also becoming increasingly difficult to eradicate and the main reason for this is growing primary antibiotic resistance rates in a world where antibiotics are frequently prescribed and readily available. Despite knowing much more about the bacterium since its discovery, such as its genomic makeup and pathogenesis, we have seen declining treatment success. Therefore, clinicians today must be prepared to face one, two or even multiple treatment failures, and should be equipped with sufficient knowledge to decide on the appropriate salvage therapy when this happens. This article discusses the factors contributing to treatment failure and reviews the second and third-line treatment strategies that have been investigated. Established empiric second line treatment options include both bismuth based quadruple therapy and levofloxacin based triple therapy. Antibiotic testing is recommended prior to initiating third line treatment. In the event that antibiotic susceptibility testing is unavailable, third line treatment options include rifabutin, rifaximin and sitafloxacin based therapies.

Crystal Growth and Spectroscopic Investigations of Tm3+:Li3Ba2Gd3(MoO4)8 Crystal.

Tm3+:Li3Ba2Gd3(MoO4)8 crystal has been grown by the top seeded solution growth (TSSG) method from a Li2MoO4 flux. The room temperature polarized absorption spectra, fluorescence spectra, and fluorescence decay curves of the crystal were measured. Based on the Judd-Ofelt (J-O) theory, the main spectroscopic parameters of the crystal, including the spontaneous emission probabilities, fluorescence branching ratios, and radiative lifetimes were calculated and analyzed. The broad and strong absorption bands of the crystal show that it can be efficiently pumped by the diode laser, while the large emission cross-sections of the ³F4 → ³H6 transition indicate that the crystal is a promising candidate for tunable and short pulse lasers.

A greedy algorithm for gene selection based on SVM and correlation.

Microarrays serve scientists as a powerful and efficient tool to observe thousands of genes and analyse their activeness in normal or cancerous tissues. In general, microarrays are used to measure the expression levels of thounsands of genes in a cell mixture. Gene expression data obtained from microarrays can be used for various applications. One such application is that of gene selection. Gene selection is very similar to the feature selection problem addressed in the machine-learning area. In a nutshell, gene selection is the problem of identifying a minimum set of genes that are responsible for certain events (for example the presence of cancer). Informative gene selection is an important problem arising in the analysis of microarray data. In this paper, we present a novel algorithm for gene selection that combines Support Vector Machines (SVMs) with gene correlations. Experiments show that the new algorithm, called GCI-SVM, obtains a higher classification accuracy using a smaller number of selected genes than the well-known algorithms in the literature.

2-(4H-1,2,4-Triazol-4-yl)phenol.

In the title compound, C(8)H(7)N(3)O, the dihedral angle between the benzene and triazole rings is 41.74 (12)°.