Supported molybdenum oxides as effective catalysts for the catalytic fast pyrolysis of lignocellulosic biomass

The catalytic fast pyrolysis (CFP) of pine was investigated over 10 wt% MoO[subscript 3]/TiO[subscript 2] and MoO[subscript 3]/ZrO[subscript 2] at 500 °C and H[subscript 2] pressures ≤0.75 bar. The product distributions were monitored in real time using a molecular beam mass spectrometer (MBMS). Both supported MoO[subscript 3] catalysts show different levels of deoxygenation based on the cumulative biomass to MoO[subscript 3] mass ratio exposed to the catalytic bed. For biomass to MoO[subscript 3] mass ratios <1.5, predominantly olefinic and aromatic hydrocarbons are produced with no detectable oxygen-containing species. For ratios ≥1.5, partially deoxygenated species comprised of furans and phenols are observed, with a concomitant decrease of olefinic and aromatic hydrocarbons. For ratios ≥5, primary pyrolysis vapours break through the bed, indicating the onset of catalyst deactivation. Product quantification with a tandem micropyrolyzer–GCMS setup shows that fresh supported MoO[subscript 3] catalysts convert ca. 27 mol% of the original carbon into hydrocarbons comprised predominantly of aromatics (7 C%), olefins (18 C%) and paraffins (2 C%), comparable to the total hydrocarbon yield obtained with HZSM-5 operated under similar reaction conditions. Post-reaction XPS analysis on supported MoO[subscript 3]/ZrO[subscript 2] and MoO[subscript 3]/TiO[subscript 2] catalysts reveal that ca. 50% of Mo surface species exist in their partially reduced forms (i.e., Mo5[superscript +] and Mo3[superscript +]), and that catalyst deactivation is likely associated to coking.BP (Firm) (MIT Energy Initiative. Advanced Conversion Research Program)National Science Foundation (U.S.) (Award 1454299

Correlation of Serum Insulin-Like Growth Factor-1 and Hand Wrist Radiographs as Skeletal Maturity Indicators: An ex-vivo Study

Introduction: Conventional Hand and Wrist radiographs, have certain drawbacks of exposing orthodontic patients to unnecessary radiation hazards and subjectivity to errors. Serum insulin-like growth factor 1 (IGF-1) levels have been reported to increase until the pubertal peak in literature. The present study aims to assess the relationship between serum IGF-1 and skeletal maturity indicators Materials and Methods: Lateral cephalograms of 60 patients were assigned SMI stage according to Fishman’s classification system. The serum IGF-1 levels of the patients were also evaluated. Correlation between the serum IGF-1 levels, age of the patient, and their SMI stage was analyzed. Results: Pearson's coefficient of correlation revealed a non-significant weak positive correlation (p=0.69; &gt;0.05) between age and IGF-1 levels, and a non-significant weak negative correlation (p =0.52; &gt;0.05) between SMI stages and IGF-1 levels. Results of the ANOVA test indicated that there was no significant difference between mean IGF-1 levels across the different age groups and eleven SMI groups. However, there was a significant difference noted in the mean IGF-1 levels and the restructured SMI categories and groups. Conclusion: The moderate correlation between age and serum IGF-1 fluctuations during puberty underscores the hormone's pivotal role in adolescent growth. This positions serum IGF-1 as a potentially specific and reliable marker for assessing mandibular growth modifications, offering a radiation-free alternative to conventional radiographic methods

Accidental separation and lodgment of rotary endodontic file into the dentist's thumb

Separation of the endodontic instrument within the root canal system and sharp injuries to the dentist is not an uncommon event in endodontic practice. Although root canal instruments can fracture at any stage of endodontic treatment, its fracture within the dentist's hand is a very rare event. An unusual case of accidental separation and lodgment of rotary endodontic file in the dentist's thumb is presented along with its management. A 33-year-old dentist reported with an accidental lodgment of rotary endodontic file into his thumb. The fractured instrument was removed successfully by a surgeon. The present case describes a rare event of occupational risk in endodontic practice

Structural Properties and Reactivity Trends of Molybdenum Oxide Catalysts Supported on Zirconia for the Hydrodeoxygenation of Anisole

Vapor-phase hydrodeoxygenation (HDO) of anisole was investigated at 593 K and H₂ pressures of ≤1 bar over supported MoO₃/ZrO₂ catalysts with MoO₃ loadings ranging from 1 to 36 wt % (i.e., 0.5–23.8 Mo/nm²). Reactivity studies showed that HDO activity increased proportionally with MoO₃ coverage up to a monolayer coverage (∼15 wt %) over the ZrO₂ surface. Specific rates declined for catalysts with high loadings exceeding the monolayer coverage, because of a decreasing amount of redox-active species, as confirmed by oxygen chemisorption experiments. For low catalyst loadings (1 and 5 wt %), the selectivities toward fully deoxygenated aromatics were 13 and 24% on a C-mol basis, respectively, while at intermediate and high loadings (10–36 wt %), the selectivity was ∼40%. Post-reaction characterization of the spent catalysts using X-ray diffraction and X-ray photoelectron spectroscopy showed that the catalysts with 25 and 36 wt % MoO₃ loadings were over-reduced, as evidenced by the prevalence of Mo⁴⁺ and Mo³⁺ oxidation states summing to 54 and 67%, respectively. In contrast, catalysts with low and intermediate Mo loadings exhibited a prevalence of Mo⁶⁺ species (∼60%). We hypothesize that Mo⁵⁺ species are more easily stabilized in oligomeric and isolated forms over the zirconia support. The catalysts with intermediate loadings feature HDO and alkylation rates higher than those of catalysts with low loadings because the latter feature a higher proportion of isolated species. Once the monolayer coverage is exceeded, MoO₃ crystallites are formed, which can undergo facile reduction to less reactive MoO₂

Dysbiosis of the beneficial gut bacteria in patients with Parkinson's disease from India

Objectives: Recent advancement in understanding neurological disorders has revealed the involvement of dysbiosis of the gut microbiota in the pathophysiology of Parkinson's disease (PD). We sequenced microbial DNA using fecal samples collected from PD cases and healthy controls (HCs) to evaluate the role of gut microbiota. Methods: Full-length bacterial 16S rRNA gene sequencing of fecal samples was performed using amplified polymerase chain reaction (PCR) products on the GridION Nanopore sequencer. Sequenced data were analyzed using web-based tools BugSeq and MicrobiomeAnalyst. Results: We found that certain bacterial families like Clostridia UCG 014, Cristensenellaceae, and Oscillospiraceae are higher in abundance, and Lachinospiracea, Coriobacteriaceae and genera associated with short-chain fatty acid production, Faecalibacterium, Fusicatenibacter, Roseburia and Blautia, are lower in abundance among PD cases when compared with the HC. Genus Akkermansia, Dialister, Bacteroides, and Lachnospiraceae NK4A136 group positively correlated with constipation in PD. Conclusion: Observations from this study support the other global research on the PD gut microbiome background and provide fresh insight into the gut microbial composition of PD patients from a south Indian population. We report a higher abundance of Clostridia UCG 014 group, previously not linked to PD

Encapsulation of Molybdenum Carbide Nanoclusters inside Zeolite Micropores Enables Synergistic Bifunctional Catalysis for Anisole Hydrodeoxygenation

Molybdenum carbide (MoC_<i>x</i>) nanoclusters were encapsulated inside the micropores of aluminosilicate FAU zeolites to generate highly active and selective bifunctional catalyst for the hydrodeoxygenation of anisole. Interatomic correlations obtained with differential pair distribution function analysis confirmed the intraparticle structure and the uniform size of the MoC_<i>x</i> nanoclusters. The reactivity data showed the preferential production of alkylated aromatics (such as toluene and xylene) over benzene during the hydrodeoxygenation of anisole as well as the minimization of unwanted CH₄ formation. Control experiments demonstrated the importance of MoC_<i>x</i> encapsulation to generate an efficient bifunctional catalyst with superior carbon utilization and on-stream stability