Novel Vanadia/meso-Co3O4 catalysts for the conversion of benzene-toluene-xylene to environmental friendly components via catalytic oxidation

Three - dimensional meso-porous Co₃O₄ was prepared by nanocasting pathway based on the use of mesoporous silica (KIT-6) as hard template with different Cobalt concentrations (0.5-2.5 mol ratio based on mesoporous silica KIT-6). The prepared samples was used as supports for preparing V₂O₅/Co₃O₄ (1, 6 wt% of V₂O₅) catalysts. The prepared samples were characterized by different techniques. The catalytic activity of the prepared samples were evaluated in the complete oxidation reaction of toluene, benzene, and/or p-xylene; (as model reactants of volatile organic compounds) in terms of CO₂. The catalytic reaction was carried out in a fixed-bed micro-reactor operated under atmospheric pressure and within the reaction temperature range of 200-400 °C. The data confirmed that the three dimensional-mesoporous Co₃O₄ (1.0 mole ratio) replicated sample possessed improved different parameters compared to those of the Co₃O₄ sample with other mole ratios. The data reflected the yield of Co2 is decreased upon the increase in reaction temperature to 400°C. 1 wt.% V₂O₅/m-Co₃O₄ catalyst shows a reverse direction, the CO₂ yield slowly increased in the range 150-250 °C, then jumped at 300 °C until maximum yield (100%) is observed at 400 °C. 1 wt.% V₂O₅/m-Co₃O₄ catalyst was found to be the active and selective promised catalyst for the complete oxidation of either individual aromatic volatile organic compounds (benzene, toluene, and/or xylene) and/or their mixtures to 100% CO₂.

Hybrid Nanoarchitectonics with Cr, Fe-MOF/ Graphene Nanocomposite for Removal of Organic Sulfur Compounds from Diesel Fuel

Metal–organic frameworks (Cr-MOF and Fe-MOF) and their graphene hybride nano-composites were prepared via green solvo-themal method. The prepared samples were characterized by XRD, FTIR spectroscopy, N2 adsorption–desorption isotherm and XPS. The composites were used for the adsorption of thiophenic sulfur compound (thiophene, dibenzothiophene, 4,6-dimethyldibenzothiophene) in a model fuel oil. It was found that, graphene in the MOF composite has positive effect on sulfur removal. The removal efficiency increase from 62% to % 95.6 using Fe-MOF and Fe-MOF/Gr (9:1), respectively. This enhancement effect is attributed to a greater number of coordinatively unsaturated sites (CUS) in the composites. The results indicated that the adsorption reach to 96.6% for DBT adsorption from model diesel oil and 62% for diesel fuel on using Cr-MOF/Gr composite.

Cr, Fe-MOF/ Graphene Hybrid Nanocomposite for Ultra Removal of Organic Sulfur Compounds from Diesel Fuel.. [DOI: 10.21203/rs.3.rs-1704462/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Metal-organic frameworks (Cr-MOF and Fe-MOF) and their graphene hybrid nano-composites were prepared via the green solvo-thermal method. The prepared samples were characterized by XRD, FTIR spectroscopy, N2 adsorption-desorption isotherm, and XPS. The composites were used for the adsorption of thiophenic sulfur compound (thiophene, dibenzothiophene, 4,6-dimethyldibenzothiophene) in a model fuel oil. It was found that graphene in the MOF composite has a positive effect on sulfur removal. The removal efficiency increase from 62 % to % 95.6 using Fe-MOF and Fe-MOF/Gr (9:1), respectively. This enhancement effect is attributed to a higher number of coordinatively unsaturated sites (CUS) in the composites. The results indicated that the adsorption reaches to 96.6% for DBT adsorption from model diesel oil and 62% for diesel fuel on using Cr-MOF/Gr composite.

Diamondites: evidence for a distinct tectono-thermal diamond-forming event beneath the Kaapvaal craton

The petrogenesis and relationship of diamondite to well-studied monocrystalline and fibrous diamonds are poorly understood yet would potentially reveal new aspects of how diamond-forming fluids are transported through the lithosphere and equilibrate with surrounding silicates. Of 22 silicate- and oxide-bearing diamondites investigated, most yielded garnet intergrowths (n = 15) with major element geochemistry (i.e. Ca-Cr) classifying these samples as low-Ca websteritic or eclogitic. The garnet REE patterns fit an equilibrium model suggesting the diamond-forming fluid shares an affinity with high-density fluids (HDF) observed in fibrous diamonds, specifically on the join between the saline-carbonate end-members. The δ¹³C values for the diamonds range from - 5.27 to - 22.48‰ (V-PDB) with δ¹⁸O values for websteritic garnets ranging from + 7.6 to + 5.9‰ (V-SMOW). The combined C-O stable isotope data support a model for a hydrothermally altered and organic carbon-bearing subducted crustal source(s) for the diamond- and garnet-forming media. The nitrogen aggregation states of the diamonds require that diamondite-formation event(s) pre-dates fibrous diamond-formation and post-dates most of the gem monocrystalline diamond-formation events at Orapa. The modelled fluid compositions responsible for the precipitation of diamondites match the fluid-poor and fluid-rich (fibrous) monocrystalline diamonds, where all grow from HDFs within the saline-silicic-carbonatitic ternary system. However, while the nature of the parental fluid(s) share a common lithophile element geochemical affinity, the origin(s) of the saline, silicic, and/or carbonatitic components of these HDFs do not always share a common origin. Therefore, it is wholly conceivable that the diamondites are evidence of a distinct and temporally unconstrained tectono-thermal diamond-forming event beneath the Kaapvaal craton.

Metal organic framework-graphene nano-composites for high adsorption removal of DBT as hazard material in liquid fuel

Nowadays, one of the most important energy issues is how to deal with the sulfur removal from liquid fuels in a simple and inexpensive ways. Adsorptive desulphurization process can solve this issue when use highly effective adsorbent like metal organic frameworks (MOFs) and its nano-composites. In this context, this study uses the green solvo-themal method for the preparation of MOF (Cu-BTC) and MOF/Graphene hybrid nano-composite to be used as an effective DBT adsorbent from the model fuels. The prepared adsorbents were characterized by using different analytical techniques like: XRD, FTIR, BET, and TEM. Adsorption experimental results demonstrated that the composite material MOF/Gr (9:1 wt ratio) exhibited extra ordinary high dibenzothiophene adsorption with adsorption capacity (46.2 mg S/g) under the optimum experimental conditions. Kinetic and Langmuir and Freundlich isotherm were also studied.

Outcomes of nutritional interventions to treat dysphagia in esophageal cancer: a population-based study

Esophageal cancer (EC) is increasing in prevalence due to rising incidence and improved treatment strategies. Dysphagia is a significant morbidity in patients with EC requiring nutritional intervention. We sought to evaluate outcomes of nutritional interventions for EC patients hospitalized with dysphagia at a population level. The National Inpatient Sample (2002-2012) was utilized to include all adult inpatients (≥18 years of age) with EC and presence of dysphagia and stricture that underwent nutritional interventions including feeding tube (FT) placement, esophageal stenting, or parenteral nutrition (PN). Temporal trends were examined with multivariate analysis performed for mortality, length of stay (LOS), and cost of hospitalization. A total of 509,593 EC patients had 12,205 hospitalizations related to dysphagia. The hospitalization rates doubled over the study period (1.52% vs. 3.28%, p < 0.001). The most common nutritional intervention was FT (27%), followed by esophageal stenting (13%), and PN (11%). PN was more frequently associated with a diagnosis of sepsis (6.1%, p = 0.023) compared to FT (2.5%) or esophageal stenting (1.8%). Multivariate analysis demonstrated FT and esophageal stenting had comparable mortality (OR 1.06, 95% CI: 0.49, 2.32); however, PN was associated with higher mortality (OR 2.37, 95% CI: 1.22, 4.63), cost of hospitalization ($5,510, 95% CI: 2,262, 8,759), and LOS (2.13 days, 95% CI: 0.72, 3.54). This study shows that hospitalizations for EC with dysphagia and related nutritional interventions are increasing. As a single modality, parenteral nutrition should be avoided. Among our esophageal stent and FT population, further studies are necessary to determine adequate interventions based on disease stage.

The geobiological nitrogen cycle: From microbes to the mantle

Nitrogen forms an integral part of the main building blocks of life, including DNA, RNA, and proteins. N₂ is the dominant gas in Earth's atmosphere, and nitrogen is stored in all of Earth's geological reservoirs, including the crust, the mantle, and the core. As such, nitrogen geochemistry is fundamental to the evolution of planet Earth and the life it supports. Despite the importance of nitrogen in the Earth system, large gaps remain in our knowledge of how the surface and deep nitrogen cycles have evolved over geologic time. Here, we discuss the current understanding (or lack thereof) for how the unique interaction of biological innovation, geodynamics, and mantle petrology has acted to regulate Earth's nitrogen cycle over geologic timescales. In particular, we explore how temporal variations in the external (biosphere and atmosphere) and internal (crust and mantle) nitrogen cycles could have regulated atmospheric pN₂ . We consider three potential scenarios for the evolution of the geobiological nitrogen cycle over Earth's history: two in which atmospheric pN₂ has changed unidirectionally (increased or decreased) over geologic time and one in which pN₂ could have taken a dramatic deflection following the Great Oxidation Event. It is impossible to discriminate between these scenarios with the currently available models and datasets. However, we are optimistic that this problem can be solved, following a sustained, open-minded, and multidisciplinary effort between surface and deep Earth communities.

A phase II and pharmacodynamic study of sunitinib in relapsed/refractory oesophageal and gastro-oesophageal cancers

BACKGROUND

Blockade of the vascular endothelial growth factor (VEGF) pathway shows evidence of activity in gastro-oesophageal (GE) and oesophageal cancer. We investigated the efficacy of sunitinib, a multikinase VEGF inhibitor, in patients with relapsed/refractory GE/oesophageal cancer.

METHODS

This was a single-stage Fleming phase II study. The primary end point was progression-free survival (PFS) at 24 weeks. If five or more patients out of a total of 25 were free of progressive disease at 24 weeks, sunitinib would be recommended for further study. Patients received sunitinib 37.5 mg orally daily and imaged every 6 weeks. Exploratory correlative analysis included serum growth factors, tumour gene expression and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI).

RESULTS

Twenty-five evaluable patients participated in the study. Progression-free survival at 24 weeks was 8% (n=2 patients; confidence interval (CI): 95% 1.4-22.5%), and the duration of best response for the patients was 23 and 72 weeks. Ten patients (42%) had stable disease (SD) for >10 weeks. Overall response rate is 13%. Median PFS is 7 weeks (95% CI: 5.6-11.4 weeks) and the median overall survival is 17 weeks (95% CI: 8.9-25.3 weeks). Most common grade 3/4 toxicities included fatigue (24%), anaemia (20%) thrombocytopenia (16%), and leucopenia (16%). No patients discontinued therapy due to toxicity. Serum VEGF-A and -C levels, tumour complement factor B (CFB) gene expression, and DCE-MRI correlated with clinical benefit, defined as SD or better as best response.

CONCLUSION

Sunitinib is well tolerated but only a select subgroup of patients benefited. Serum VEGF-A and -C may be early predictors of benefit. On this study, patients with clinical benefit from sunitinib had higher tumour CFB expression, and thus has identified CFB as a potential predictor for efficacy of anti-angiogenic therapy. These findings need validation from future prospective trials.

An unusual presentation of late oesophagojejunal anastomotic leak after total D2 gastrectomy

Oesophagojejunal anastomotic leak usually presents in the early post-operative period with abdominal pain and sepsis. We report a case of late anastomotic leak presenting as epigastric pain with hyperamylasaemia and discuss the differential diagnosis.

The prevalence of disorders of haemostasis in adolescents with menorrhagia referred to a haemophilia treatment centre

Menorrhagia at the time of menarche is relatively common and historically attributed primarily to immaturity of the pituitary-ovarian-uterine axis. Intuitively, a proportion of these patients should have an underlying disorder of haemostasis, given the 5-20% prevalence of von Willebrand's disease and the > or =20% prevalence of platelet dysfunction in light of recent epidemiological studies in menorrhagia, although the average age of the patients in those studies has been approximately 35 years. However, there are a few comprehensive studies in the adolescent population determining whether widespread haemostasis evaluation should be carried out in adolescents presenting with menorrhagia. A retrospective chart review study of disorders of haemostasis was carried out in 61 consecutive adolescent patients, ages 11-19 at the time of evaluation referred to the Hemophilia Treatment Center (HTC)/Hematology unit. The mean and median ages were 15 +/- 2.2 and 14 years (11, 19), respectively. Standard evaluation included complete blood count, prothrombin time, partial thromboplastin time, von Willebrand factor (VWF) levels and platelet aggregation. The proportion of patients with VWF deficiency was 22/61 (36%) [95% confidence interval (CI), 24-49%]; the proportion of patients with platelet aggregation abnormalities was 4/61 (7%) (95% CI, 2-16%). There was no difference in the frequency of additional muco-cutaneous bleeding symptoms. A relatively high proportion of adolescents are identified with an underlying disorder of haemostasis when referred to an HTC for evaluation of menorrhagia. This involves in part a selective referral bias, but underscores the role of the HTC in evaluating adolescents referred with menorrhagia for an underlying bleeding disorder, given the relatively high yield of haemostatic disorders detected in this setting.