Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Electrostatic Control of Orbital Ordering in Noncubic Crystals

In noncubic insulating crystals where active orbitals are not degenerate the usual models to describe orbital ordering, Kugel–Khomskii and Jahn–Teller, are, in principle, not valid. For these materials we show, by means of first-principles calculations, that a key driving force behind orbital ordering is the electrostatic potential, <i>V</i>_R(<b>r</b>), created by the rest of lattice ions over the magnetic complex where active electrons are localized. In order to illustrate the key influence of <i>V</i>_R(<b>r</b>), often ignored in a true microscopic approach, we focus on K₂CuF₄ and La₂CuO₄ as model crystals since they have very similar electronic structure but, surprisingly, contrasting orbital orderings, antiferrodistortive and ferrodistortive, respectively. Considering the parent K₂NiF₄ structure (tetragonal space group <i>I</i>4/<i>mmm</i>) of both lattices, it is shown that in K₂CuF₄ the hole in a CuF₆^4– complex is forced by the anisotropy of <i>V</i>_R(<b>r</b>) to be in a 3<i>z</i>² – <i>r</i>² orbital, while for La₂CuO₄ the shape of <i>V</i>_R(<b>r</b>) forces the hole to be placed in the planar <i>x</i>² – <i>y</i>² orbital. As a salient feature, it is found that in the parent structure the orbitals of K₂CuF₄ are ferrodistortively ordered in contrast to the Kugel–Khomskii prediction. At the same time, it is also shown that in K₂CuF₄ this state is unstable and distorts to the experimental antiferrodistortive state where, despite the significant in-plane distortion, the hole is still found to be in a mainly 3<i>z</i>² – <i>r</i>² orbital, a fact in agreement with experimental magnetic resonance data. For this compound, it is found that <i>V</i>_R(<b>r</b>) induces changes on the energy of 3d levels, which are 2 orders of magnitude higher than those due to superexchange interactions. The present results stress that in insulating transition metal compounds with electrons localized on complexes the rest of the lattice ions play a key role for understanding the electronic and structural properties that is, in many cases, overlooked. The present ideas are also shown to account for the orbital ordering in other noncubic materials, like Na₃MnF₆, NaCrF₄, or Sr₂La₂CuTi₃O₁₂, and thus open a window in the design of magnetic materials

Origin of the Exotic Blue Color of Copper-Containing Historical Pigments

The study of chemical factors that influence pigment coloring is a field of fundamental interest that is still dominated by many uncertainties. In this Article, we investigate, by means of ab initio calculations, the origin of the unusual bright blue color displayed by historical Egyptian Blue (CaCuSi₄O₁₀) and Han Blue (BaCuSi₄O₁₀) pigments that is surprisingly not found in other compounds like BaCuSi₂O₆ or CaCuO₂ containing the same CuO₄^6– chromophore. We show that the differences in hue between these systems are controlled by a large red-shift (up to 7100 cm^–1) produced by an electrostatic field created by a lattice over the CuO₄^6– chromophore from the energy of the 3<i>z</i>²-<i>r</i>² → <i>x</i>²-<i>y</i>² transition, a nonlocal phenomenon widely ignored in the realm of transition metal chemistry and strongly dependent upon the crystal structure. Along this line, we demonstrate that, although SiO₄^4– units are not involved in the chromophore itself, the introduction of sand to create CaCuSi₄O₁₀ plays a key role in obtaining the characteristic hue of the Egyptian Blue pigment. The results presented here demonstrate the opportunity for tuning the properties of a given chromophore by modifying the structure of the insulating lattice where it is located

Strain-Induced Ferromagnetic to Antiferromagnetic Crossover in d⁹‑Ion (Cu²⁺ and Ag²⁺)‑Layered Perovskites

A characteristic aspect of undoped high-temperature layered copper oxide superconductors is their strong in-plane antiferromagnetic coupling. This state is markedly different from that found in other chemically similar copper- or silver-layered fluorides, which display a ferromagnetic ground state. The latter has been connected in the literature with the presence of an orthorhombic deformation of the lattice that shifts the intermediate ligand between two metal ions to be closer to one and further from the other. This distortion is completely absent in the oxides, which are essentially tetragonal. However, no quantitative information exists about how this distortion influences the antiferromagnetic state and its relative stability with respect to the ferromagnetic state. Here, we carry out first-principles simulations to show that the fluorides in the parent tetragonal phase are also antiferromagnetic and that the antiferromagnetic-to-ferromagnetic transition is only triggered for a large enough distortion, with a typical ligand shift of 0.1 Å. Moreover, we employ a valence-bond model and second-principles simulations to show that the factor in superexchange that favors the antiferromagnetic state reduces as the ligand moves away from the symmetric metal–metal position. Importantly, we find that this distortion is sensitive to the application of an epitaxial strain which, in turn, allows controlling the difference of energy between ferromagnetic and antiferromagnetic states and thus the Curie or Néel temperatures. In fact, for compressive strains larger than 5.1%, this piezomagnetic effect makes K2CuF4 and Cs2AgF4 antiferromagnetic, making these two lattices close chemical analogs of oxide superconductors

Exploring the effect of composting technologies on the recovery of hydrocarbon contaminated soil post chemical oxidative treatment

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous organic pollutants that contaminate large areas. They are mainly released to environment by anthropogenic activities principally due to the petrochemical industry. The low biodegradation rate characteristic of PAHs in aged contaminated soils could be overcome trough the chemical oxidation. In this study, composting with the soil and stimulation with mature compost were the strategies applied in soil microcosms after chemical oxidation with ammonium persulfate in a PAHs chronically contaminated soil. A 29% of PAHs elimination and an increase of their bioavailability were found after chemical oxidation with ammonium persulfate. Due to the oxidative treatment the total bacterial and the gram-positive population PAH dioxygenase genes were significantly reduced and no gram-negative PAHs degraders were detected. The following application of organic amendments produced a higher increase in total bacteria and recovery of the degrading population of GP PAH after one year of treatment, in comparison with the pre-oxidized soil bioremediation, only promoted by irrigation and aeration. Also a significant increase in the content of bioavailable PAHs was observed. However, from both composting strategies only the stimulation with mature compost led to a net PAHs removal. Taking into account the residual dissolved total carbon and humification degree (E4/E6 ratio), it was attributed to the preferential consumption of more easily degradable compounds than hydrocarbons the low removal efficiency observed after one year of treatment. Due to the high bioavailable content of PAH and the residual sulfate, long-term treatments will require careful monitoring to reduce environmental risk

Diaminogermylene and Diaminostannylene Derivatives of Gold(I): Novel AuM and AuM₂ (M = Ge, Sn) Complexes

The reactions of [AuCl­(THT)] (THT = tetrahydrothiophene) with 1 equiv of the group 14 diaminometalenes M­(HMDS)₂ [M = Ge, Sn; HMDS = N­(SiMe₃)₂] lead to [Au­{MCl­(HMDS)₂}­(THT)] [M = Ge (<b>1</b>), Sn (<b>2</b>)], which contain a metalate­(II) ligand that arises from insertion of the corresponding M­(HMDS)₂ reagent into the Au–Cl bond of the gold­(I) reagent. While compound <b>1</b> reacts with more Ge­(HMDS)₂ to give the germanate–germylene derivative [Au­{GeCl­(HMDS)₂}­{Ge­(HMDS)₂}] (<b>3</b>), which results from substitution of Ge­(HMDS)₂ for the THT ligand of <b>1</b>, an analogous treatment of compound <b>2</b> with Sn­(HMDS)₂ gives the stannate–stannylene derivative [Au­{SnCl­(HMDS)₂}­{Sn­(HMDS)₂(THT)}] (<b>4</b>), which has a THT ligand attached to the stannylene tin atom and which, in solution at room temperature, participates in a dynamic process that makes its two Sn­(HMDS)₂ fragments equivalent (on the NMR time scale). A similar dynamic process has not been observed for the AuGe₂ compound <b>3</b> or for the AuSn₂ derivatives [Au­{SnR­(HMDS)₂}­{Sn­(HMDS)₂(THT)}] [R = Bu (<b>5</b>), HMDS (<b>6</b>)], which have been prepared by treating complex <b>4</b> with LiR. The structures of compounds <b>1</b> and <b>3</b>–<b>6</b> have been determined by X-ray diffraction

Diaminogermylene and Diaminostannylene Derivatives of Gold(I): Novel AuM and AuM₂ (M = Ge, Sn) Complexes

The reactions of [AuCl­(THT)] (THT = tetrahydrothiophene) with 1 equiv of the group 14 diaminometalenes M­(HMDS)₂ [M = Ge, Sn; HMDS = N­(SiMe₃)₂] lead to [Au­{MCl­(HMDS)₂}­(THT)] [M = Ge (<b>1</b>), Sn (<b>2</b>)], which contain a metalate­(II) ligand that arises from insertion of the corresponding M­(HMDS)₂ reagent into the Au–Cl bond of the gold­(I) reagent. While compound <b>1</b> reacts with more Ge­(HMDS)₂ to give the germanate–germylene derivative [Au­{GeCl­(HMDS)₂}­{Ge­(HMDS)₂}] (<b>3</b>), which results from substitution of Ge­(HMDS)₂ for the THT ligand of <b>1</b>, an analogous treatment of compound <b>2</b> with Sn­(HMDS)₂ gives the stannate–stannylene derivative [Au­{SnCl­(HMDS)₂}­{Sn­(HMDS)₂(THT)}] (<b>4</b>), which has a THT ligand attached to the stannylene tin atom and which, in solution at room temperature, participates in a dynamic process that makes its two Sn­(HMDS)₂ fragments equivalent (on the NMR time scale). A similar dynamic process has not been observed for the AuGe₂ compound <b>3</b> or for the AuSn₂ derivatives [Au­{SnR­(HMDS)₂}­{Sn­(HMDS)₂(THT)}] [R = Bu (<b>5</b>), HMDS (<b>6</b>)], which have been prepared by treating complex <b>4</b> with LiR. The structures of compounds <b>1</b> and <b>3</b>–<b>6</b> have been determined by X-ray diffraction

Diaminogermylene and Diaminostannylene Derivatives of Gold(I): Novel AuM and AuM₂ (M = Ge, Sn) Complexes

The reactions of [AuCl­(THT)] (THT = tetrahydrothiophene) with 1 equiv of the group 14 diaminometalenes M­(HMDS)₂ [M = Ge, Sn; HMDS = N­(SiMe₃)₂] lead to [Au­{MCl­(HMDS)₂}­(THT)] [M = Ge (<b>1</b>), Sn (<b>2</b>)], which contain a metalate­(II) ligand that arises from insertion of the corresponding M­(HMDS)₂ reagent into the Au–Cl bond of the gold­(I) reagent. While compound <b>1</b> reacts with more Ge­(HMDS)₂ to give the germanate–germylene derivative [Au­{GeCl­(HMDS)₂}­{Ge­(HMDS)₂}] (<b>3</b>), which results from substitution of Ge­(HMDS)₂ for the THT ligand of <b>1</b>, an analogous treatment of compound <b>2</b> with Sn­(HMDS)₂ gives the stannate–stannylene derivative [Au­{SnCl­(HMDS)₂}­{Sn­(HMDS)₂(THT)}] (<b>4</b>), which has a THT ligand attached to the stannylene tin atom and which, in solution at room temperature, participates in a dynamic process that makes its two Sn­(HMDS)₂ fragments equivalent (on the NMR time scale). A similar dynamic process has not been observed for the AuGe₂ compound <b>3</b> or for the AuSn₂ derivatives [Au­{SnR­(HMDS)₂}­{Sn­(HMDS)₂(THT)}] [R = Bu (<b>5</b>), HMDS (<b>6</b>)], which have been prepared by treating complex <b>4</b> with LiR. The structures of compounds <b>1</b> and <b>3</b>–<b>6</b> have been determined by X-ray diffraction