Hysteresis in the Physisorption of CO₂ and N₂ in a Flexible Pillared Layer Nickel Cyanide

Rare hysteretic adsorption/desorption isotherms are reported for CO2 and N2 on a pillared Ni(1,2-bis(4-pyridyl)ethylene)[Ni(CN)4] compound (NiBpeneNiCN). The hysteresis occurs under moderate pressure and at temperatures above the critical temperatures of the respective gases. Powder X-ray diffraction measurements indicate that the material is an extended three-dimensional analogue of the well-known Hofmann clathrates which is formed through axial bridging of the in-plane octahedral Ni sites by the bidentate 1,2-bis(4-pyridyl)ethylene. The hysteretic behavior toward guest adsorption and desorption is attributed to a structural phase transition in the material resulting from a variation in the tilt angle of the 1,2-bis(4-pyridyl)ethylene pillars. Kinetics studies on the desorption of acetone from the material show two first-order processes with two rate constants yielding activation energies of 68 and 55 kJ/mol when loadings are greater than 1 equiv of acetone per formula unit. The CO2 adsorption/desorption isotherms on the series of structurally similar Ni(L)[Ni(CN)4] compounds, where L = pyrazine, 4,4′-bipyridine, 1,2-bis(4-pyridyl)ethane, and dipyridylacetylene, are also reported. In contrast to NiBpeneNiCN, the rigid members of this series show normal type I isotherms with no measureable hysteresis and no significant structural changes during the adsorption/desorption cycle, while the flexible 1,2-bis(4-pyridyl)ethane-bridged sample collapses in the guest-free state and shows no significant adsorption of CO2

Hydrogen Storage Properties of Rigid Three-Dimensional Hofmann Clathrate Derivatives: The Effects of Pore Size

The effects of pore size on the hydrogen storage properties of a series of pillared layered solids based on the M(L)[M‘(CN)4] structural motif, where M = Co or Ni, L = pyrazine (pyz), 4,4‘-bipyridine (bpy), or 4,4‘-dipyridylacetylene (dpac), and M‘ = Ni, Pd, or Pt, has been investigated. The compounds all possess slitlike pores with constant in-plane dimensions and similar organic functionality. The pore heights vary as a function of L and provide a means for a systematic investigation of the effects of pore dimension on hydrogen storage properties in porous materials. Hydrogen isotherms were measured at 77 and 87 K up to a pressure of 1 atm. The pyz pillared materials with the smallest pore dimensions store hydrogen at a pore density similar to that of liquid hydrogen. The adsorbed hydrogen density drops by a factor of 2 as the relative pore size is tripled in the dpac material. The decreased storage efficiency diminishes the expected gravimetric gain in capacity for the larger pore materials. The heats of adsorption were found to range from 6 to 8 kJ/mol in the series and weakly correlate with pore size

MOESM6 of Effect of nitric oxide on postoperative acute kidney injury in patients who underwent cardiopulmonary bypass: a systematic review and meta-analysis with trial sequential analysis

Additional file 6. Forest plot for the length of ICU stay. MD, mean difference. SD, standard deviation; CI, confidential interval; NO, nitric oxide

MOESM2 of Effect of nitric oxide on postoperative acute kidney injury in patients who underwent cardiopulmonary bypass: a systematic review and meta-analysis with trial sequential analysis

Additional file 2. Risk of bias graph

MOESM8 of Effect of nitric oxide on postoperative acute kidney injury in patients who underwent cardiopulmonary bypass: a systematic review and meta-analysis with trial sequential analysis

Additional file 8. Forest plot for the risk of postoperative hemorrhage, i.e., requiring blood transfusion after the operation or reoperation. RR, risk ratio. CI, confidential interval; NO, nitric oxide

MOESM3 of Effect of nitric oxide on postoperative acute kidney injury in patients who underwent cardiopulmonary bypass: a systematic review and meta-analysis with trial sequential analysis

Additional file 3. Funnel plot for the primary outcome

MOESM5 of Effect of nitric oxide on postoperative acute kidney injury in patients who underwent cardiopulmonary bypass: a systematic review and meta-analysis with trial sequential analysis

Additional file 5. Forest plot for sensitivity analysis including studies that had lower risk of bias and reported AKI using KDIGO criteria. RR, risk ratio. CI, confidential interval; AKI, acute kidney injury; NO, nitric oxide

MOESM4 of Effect of nitric oxide on postoperative acute kidney injury in patients who underwent cardiopulmonary bypass: a systematic review and meta-analysis with trial sequential analysis

Additional file 4. Forest plot for the Peto method. OR, odds ratio. CI, confidential interval; AKI, acute kidney injury; NO, nitric oxide

MOESM1 of Effect of nitric oxide on postoperative acute kidney injury in patients who underwent cardiopulmonary bypass: a systematic review and meta-analysis with trial sequential analysis

Additional file 1. Search strategy

MOESM9 of Effect of nitric oxide on postoperative acute kidney injury in patients who underwent cardiopulmonary bypass: a systematic review and meta-analysis with trial sequential analysis

Additional file 9. Forest plot for levels of methemoglobin at the end of CPB, %. MD, mean difference. SD, standard deviation; CI, confidential interval; NO, nitric oxide; CPB, cardiopulmonary bypass