Molybdenum Carbide Nanocatalysts at Work in the in Situ Environment: A Density Functional Tight-Binding and Quantum Mechanical/Molecular Mechanical Study

Heterogeneous reactions catalyzed by transition-metal-containing nanoparticles represent a crucial type of reaction in chemical industry. Because of the existing gap in understanding heterogeneous catalysis between a cluster of a few atoms and a bulk model of periodic slabs, reactions catalyzed by transition-metal-containing nanoparticles are still not well understood. Herein, we provide a multiscale modeling approach to study the benzene hydrogenation reactions on molybdenum carbide nanoparticles (MCNPs) in the process of in situ heavy oil upgrading. By coupling the quantum mechanical (QM) density functional tight-binding (DFTB) method with a molecular mechanical (MM) force field, a QM/MM model was built to describe the reactants, the nanoparticles and the surroundings. Umbrella sampling (US) was used to calculate the free energy profiles of the benzene hydrogenation reactions in a model aromatic solvent in the in situ heavy oil upgrading conditions. By comparing with the traditional method in computational heterogeneous catalysis, the results reveal new features of the metallic MCNPs. Rather than being rigid, they are very flexible under working condition due to the entropic contributions of the MCNPs and the solvent, which greatly affect the free energy profiles of these nanoscale heterogeneous reactions

Surface Activation of Transition Metal Nanoparticles for Heterogeneous Catalysis: What We Can Learn from Molecular Dynamics

Many heterogeneous reactions catalyzed by nanoparticles occur at relatively high temperatures, which may modulate the surface morphology of nanoparticles during reaction. Inspired by the discovery of dynamic formation of active sites on gold nanoparticles, we explore theoretically the nature of the highly mobile atoms on the surface of nanoparticles of various sizes for 11 transition metals. Using molecular dynamics simulations, on a 3 nm Fe nanoparticle as an example, the effect of surface premelting and overall melting on the structure and physical properties of the nanoparticles is analyzed. When the nanoparticle is heated up, the atoms in the outer shell appear amorphous already at 900 K. Surface premelting is reached at 1050 K, with more than three liquid atoms, based on the Lindemann criterion. The activated atoms may transfer their extra kinetic energy to the rest of the nanoparticle and activate other atoms. The dynamic studies indicate that the number of highly mobile atoms on the surface increases with temperature. Those atoms with a high Lindemann index, usually located on the edges or vertices, attain much higher kinetic energy than other atoms and potentially form different active sites in situ. When the temperature passes the surface premelting temperature, a drastic change in the coordination number (SCN) of the surface atoms occurs, with attendant dramatic broadening of the distribution of the SCN, suppling active sites with more diverse atomic coordination numbers. The electronic density of states of a nanoparticle tends to “equalize”, due to the breaking of the translational symmetry of the atoms in the nanoparticle, and the d-band center of the nanoparticle moves further away from the Fermi level as the temperature increases. Besides Au, other nanoparticles of the transition metals, such as Pt, Pd, and Ag, may also have active sites easily formed in situ

DataSheet_3_Nasal and cutaneous mucormycosis in two patients with lymphoma after chemotherapy and target therapy: Early detection by metagenomic next-generation sequencing.xlsx

Mucormycosis is a conditionally pathogenic fungal disease with high morbidity that mainly affects patients with decreased immunity. Diagnosis relies on the histopathological examination of microorganisms with the typical structure of mucormycetes in tissues and subsequent confirmation via culture. Early detection of causative microorganisms is critical to rapidly administer appropriately targeted antibiotics. Metagenomic next-generation sequencing (mNGS) is an innovative and sensitive technique used to identify pathogenic strains. Here we used mNGS to timely diagnose an infection with Lichtheimia ramosa and Mucor irregularis in two patients with hematologic malignancies; the infections manifested as nasal and cutaneous infections and developed after chemotherapy and small molecule targeted therapy. Following treatment with amphotericin B cholesteryl sulfate complex, the symptoms were reduced significantly, and both patients obtained successful outcomes. Additionally, we searched and summarized the current medical literature on the successful diagnosis of mucormycosis using mNGS. These cases indicated that mNGS, a novel culture-independent method, is capable of rapid, sensitive, and accurate identification of pathogens. mNGS may be a complementary method for the early identification of mucormycosis, allowing for appropriate and timely antibiotic administration and thus improving patient outcomes.</p

DataSheet_1_Nasal and cutaneous mucormycosis in two patients with lymphoma after chemotherapy and target therapy: Early detection by metagenomic next-generation sequencing.xls

Mucormycosis is a conditionally pathogenic fungal disease with high morbidity that mainly affects patients with decreased immunity. Diagnosis relies on the histopathological examination of microorganisms with the typical structure of mucormycetes in tissues and subsequent confirmation via culture. Early detection of causative microorganisms is critical to rapidly administer appropriately targeted antibiotics. Metagenomic next-generation sequencing (mNGS) is an innovative and sensitive technique used to identify pathogenic strains. Here we used mNGS to timely diagnose an infection with Lichtheimia ramosa and Mucor irregularis in two patients with hematologic malignancies; the infections manifested as nasal and cutaneous infections and developed after chemotherapy and small molecule targeted therapy. Following treatment with amphotericin B cholesteryl sulfate complex, the symptoms were reduced significantly, and both patients obtained successful outcomes. Additionally, we searched and summarized the current medical literature on the successful diagnosis of mucormycosis using mNGS. These cases indicated that mNGS, a novel culture-independent method, is capable of rapid, sensitive, and accurate identification of pathogens. mNGS may be a complementary method for the early identification of mucormycosis, allowing for appropriate and timely antibiotic administration and thus improving patient outcomes.</p

DataSheet_4_Nasal and cutaneous mucormycosis in two patients with lymphoma after chemotherapy and target therapy: Early detection by metagenomic next-generation sequencing.xlsx

Mucormycosis is a conditionally pathogenic fungal disease with high morbidity that mainly affects patients with decreased immunity. Diagnosis relies on the histopathological examination of microorganisms with the typical structure of mucormycetes in tissues and subsequent confirmation via culture. Early detection of causative microorganisms is critical to rapidly administer appropriately targeted antibiotics. Metagenomic next-generation sequencing (mNGS) is an innovative and sensitive technique used to identify pathogenic strains. Here we used mNGS to timely diagnose an infection with Lichtheimia ramosa and Mucor irregularis in two patients with hematologic malignancies; the infections manifested as nasal and cutaneous infections and developed after chemotherapy and small molecule targeted therapy. Following treatment with amphotericin B cholesteryl sulfate complex, the symptoms were reduced significantly, and both patients obtained successful outcomes. Additionally, we searched and summarized the current medical literature on the successful diagnosis of mucormycosis using mNGS. These cases indicated that mNGS, a novel culture-independent method, is capable of rapid, sensitive, and accurate identification of pathogens. mNGS may be a complementary method for the early identification of mucormycosis, allowing for appropriate and timely antibiotic administration and thus improving patient outcomes.</p

DataSheet_2_Nasal and cutaneous mucormycosis in two patients with lymphoma after chemotherapy and target therapy: Early detection by metagenomic next-generation sequencing.xls

Mucormycosis is a conditionally pathogenic fungal disease with high morbidity that mainly affects patients with decreased immunity. Diagnosis relies on the histopathological examination of microorganisms with the typical structure of mucormycetes in tissues and subsequent confirmation via culture. Early detection of causative microorganisms is critical to rapidly administer appropriately targeted antibiotics. Metagenomic next-generation sequencing (mNGS) is an innovative and sensitive technique used to identify pathogenic strains. Here we used mNGS to timely diagnose an infection with Lichtheimia ramosa and Mucor irregularis in two patients with hematologic malignancies; the infections manifested as nasal and cutaneous infections and developed after chemotherapy and small molecule targeted therapy. Following treatment with amphotericin B cholesteryl sulfate complex, the symptoms were reduced significantly, and both patients obtained successful outcomes. Additionally, we searched and summarized the current medical literature on the successful diagnosis of mucormycosis using mNGS. These cases indicated that mNGS, a novel culture-independent method, is capable of rapid, sensitive, and accurate identification of pathogens. mNGS may be a complementary method for the early identification of mucormycosis, allowing for appropriate and timely antibiotic administration and thus improving patient outcomes.</p

Additional file 1 of Chimeric antigen receptor T-cell therapy for relapsed and refractory thyroid cancer

Additional file 1: Detailed methods and result

Hydrogen Evolution Reaction on Hybrid Catalysts of Vertical MoS₂ Nanosheets and Hydrogenated Graphene

Two-dimensional (2D) molybdenum sulfide (MoS₂) is an attractive noble-metal-free electrocatalyst for hydrogen evolution (HER) in acids. Tremendous effort has been made to engineer MoS₂ catalysts with either more active sites or higher conductivity to enhance their HER activity. However, little attention has been paid to synergistically structural and electronic modulations of MoS₂. Herein, 2D hydrogenated graphene (HG) is introduced into MoS₂ ultrathin nanosheets for the construction of a highly efficient and stable catalyst for HER. Owing to synergistic modulations of both structural and electronic benefits to MoS₂ nanosheets via HG support, such a catalyst has improved conductivity, more accessible catalytic active sites, and moderate hydrogen adsorption energy. On the optimized MoS₂/HG hybrid catalyst, HER occurs with an overpotential of 124 mV at 10 mA cm^–2, a Tafel slope of 41 mV dec^–1, and a stable durability for 24 h continuous operation at 30 mA cm^–2 without observable fading. The high performance of the optimized MoS₂/HG hybrid catalyst for HER was interpreted with density functional theory calculations. The simulation results reveal that the introduction of HG modulates the electronic structure of MoS₂ to increase the number of active sites and simultaneously optimizes the hydrogen adsorption energy at S-edge atoms, eventually promoting HER activity. This study thus provides a strategy to design and develop high-performance HER electrocatalysts by employing different 2D materials

Morphologic analysis of BMSCs.

<p>Many RBCs were observed under phase-microscopy, after cells were seeded in cell culture flasks. RBCs in: untreated samples > after 3 volumes of RBC lysis > after 6 volumes of RBC lysis≈Ficoll samples. Fusiform adherent cells of four groups of BMSCs were observed after 24 h cultivation. Cells from four groups yielded many CFU-F colonies, when cells were cultured for 4–10 days, but the CFU-F count of the untreated sample was the greatest. At day 13, the four groups of BMSCs all had uniform spindle morphology, and reached about 100% confluence. Scale bar  = 100 µm, applies to all images.</p

Scheme of BMSC isolation.

<p>BM-PBS aspirate was divided into four fractions for comparative isolation of BMSCs: 1) untreated whole BM aspirate, 2) 3 volumes of RBC lysis with ammonium chloride, 3) 6 volumes of RBC lysis, or 4) Ficoll density-gradient centrifugation. Finally, BM-PBS mixtures were added to the cell culture medium.</p