Semiconducting two-dimensional (2D) transition metal dichalcogenides (TMDCs) are promising gas-sensing materials due to their large surface-to-volume ratio. However, their poor gas-sensing performance resulting from the low response, incomplete recovery, and insufficient selectivity hinders the realization of high-performance 2D TMDC gas sensors. Here, we demonstrate the improvement of gas-sensing performance of large-area tungsten disulfide (WS) nanosheets through surface functionalization using Ag nanowires (NWs). Large-area WS nanosheets were synthesized through atomic layer deposition of WO followed by sulfurization. The pristine WS gas sensors exhibited a significant response to acetone and NO but an incomplete recovery in the case of NO sensing. After AgNW functionalization, the WS gas sensor showed dramatically improved response (667%) and recovery upon NO exposure. Our results establish that the proposed method is a promising strategy to improve 2D TMDC gas sensors.

Recent studies suggest that the intracoronary administration of bone marrow (BM)-derived mesenchymal stem cells (MSCs) may improve left ventricular function in patients with acute myocardial infarction (AMI). However, there is still argumentative for the safety and efficacy of MSCs in the AMI setting. We thus performed a randomized pilot study to investigate the safety and efficacy of MSCs in patients with AMI. Eighty patients with AMI after successful reperfusion therapy were randomly assigned and received an intracoronary administration of autologous BM-derived MSCs into the infarct related artery at 1 month. During follow-up period, 58 patients completed the trial. The primary endpoint was changes in left ventricular ejection fraction (LVEF) by single-photon emission computed tomography (SPECT) at 6 month. We also evaluated treatment-related adverse events. The absolute improvement in the LVEF by SPECT at 6 month was greater in the BM-derived MSCs group than in the control group (5.9%±8.5% vs 1.6%±7.0%; P=0.037). There was no treatment-related toxicity during intracoronary administration of MSCs. No significant adverse cardiovascular events occurred during follow-up. In conclusion, the intracoronary infusion of human BM-derived MSCs at 1 month is tolerable and safe with modest improvement in LVEF at 6-month follow-up by SPECT. (ClinicalTrials.gov registration number: NCT01392105)

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The synthesis, coordination chemistry, and reactivity of two diphosphines containing the cyclic triaminoborane 1,8,10,9-triazaboradecalin (TBD) are described. To evaluate the ligand-centered reactivity of TBDPhos andTBDPhos, the complexes (TBDPhos)MCl and (TBDPhos)MCl, where M = Ni and Pd, were prepared and characterized by elemental analysis, multinuclear NMR spectroscopy (H, C,P, and B), and single-crystal X-ray diffraction (XRD). Despite very low boron Lewis acidity in the TBD backbone, (TBDPhos)NiCl (1) and (TBDPhos)PdCl (3) react with HO, alcohols, and hydrated fluoride reagents in the presence of NEt to yield trans H-O or H-F addition across the bridgehead N-B bond. In contrast, TBDPhos shows no appreciable reactivity when bound to NiCl (2) and PdCl (4), which is attributed to the sterically-bulky isopropyl substituents blocking substrate access to boron in the TBD backbone. The new complexes {[(TBDPhos-HO)Ni](μ-OH)}Cl (5), {[(TBDPhos-HO)Pd](μ-OH)}Cl (6), (TBDPhos-MeOH)NiCl (7), (TBDPhos-MeOH)PdCl (8), (TBDPhos-CHOH)PdCl (9), and {[(TBDPhos-HF)Ni](μ-OH)}Cl (10) were isolated, and all but 6 were structurally characterized by single-crystal XRD. Multinuclear NMR studies revealed that isolated, crystallographically-authenticated samples of 5-9 lose ligand-bound water or alcohol with reappearance of starting materials 1 and 3 when dissolved in NMR solvents. Addition of NEt attenuated the water and alcohol loss from 5-9 to allow H,C, P, andB NMR data to be collected for all the compounds, confirming the determined structures. Additional reactivity experiments with NaOMe and fluoride reagents suggested that participation of the bridgehead nitrogen in the TBD backbone is important for promoting reactivity at boron when TBDPhos is bound to Ni and Pd. The term "cooperative ligand-centered reactivity" (CLR) is proposed to define chemical reactions that appear to require participation of more than one atom on the ligand, such as those reported here.

Constraining s 3 -P compounds in nontrigonal, entatic geometries has proven to be an effective strategy for promoting biphilic oxidative addition reactions more typical of transition metals.A lthough qualitative descriptions of the impact of structure and symmetry on s 3 -P complexes have been proposed, electronic structure variations responsible for biphilic reactivity have yet to be elucidated experimentally. Reported here are PK-edge XANES data and complementary TDDFT calculations for aseries of structurally modified P(N) 3 complexes that both validate and quantify electronic structure variations proposed to give rise to biphilic reactions at phosphorus.T hese data are presented alongside experimentally referenced electronic structure calculations that reveal nontrigonal structures predicted to further enhance biphilic reactivity in s 3 -P ligands and catalysts.