Computed versus experimental energy barriers in solution: Influence of the type of the density functional approximation.

Mechanistic investigations at the density functional theory level of organic and organometallic reactions in solution are now broadly accessible and routinely implemented to complement experimental investigations. The selection of an appropriate functional among the plethora of developed ones is the first challenge on the way to reliable energy barrier calculations. To provide guidelines for the choice of an initial and reliable computational level, the performances of commonly used non-empirical (PBE, PBE0, PBE0-DH) and empirical density functionals (BLYP, B3LYP, B2PLYP) were evaluated relative to experimental activation enthalpies. Most reactivity databases to assess density functional performances are primarily based on high level calculations, here a set of experimental activation enthalpies of organic and organometallic reactions performed in solution were selected from the literature. As a general trend, the non-empirical functionals outperform the empirical ones. The most accurate energy barriers are obtained with hybrid PBE0 and double-hybrid PBE0-DH density functionals, both providing similar performance. Regardless of the functional under consideration, the addition of the GD3-BJ empirical dispersion correction does not enhance the accuracy of computed energy barriers.

Multiple pregnancy with complete hydatidiform mole and coexisting normal fetus in a retrospective cohort of 141 patients.

BACKGROUND: Multiple pregnancy with a complete hydatidiform mole and a normal fetus is prone to severe obstetrical complications and malignant transformation after birth. Prognostic information is limited for this rare form of gestational trophoblastic disease. OBJECTIVE: This study aimed to determine obstetrical outcomes and the risk of gestational trophoblastic neoplasia in women with multiple pregnancy with complete hydatidiform mole and coexisting normal fetus, and to identify risk factors for poor obstetrical and oncological outcomes to improve patient information and management. STUDY DESIGN: This was a retrospective national cohort study of 11,411 records from the French National Center for Trophoblastic Disease registered between January 2001 and January 2022. RESULTS: Among 11,411 molar pregnancies, 141 involved histologically confirmed multiple pregnancy with complete hydatidiform mole and coexisting normal fetus. Roughly a quarter of women (23%; 33/141) decided to terminate pregnancy because of presumed poor prognosis or by choice. Among the 77% of women (108/141) who continued their pregnancy, 16% of pregnancies (17/108) were terminated because of maternal complications, and 37% (40/108) ended in spontaneous miscarriage before 24 weeks' gestation. The median gestational age at delivery in the remaining 47% of pregnancies (51/108) was 32 weeks. The overall neonatal survival rate at day 8 was 36% (39/108; 95% confidence interval, 27-46) after excluding elective pregnancy terminations. Patients with free beta human chorionic gonadotropin levels <10 multiples of the median were significantly more likely to reach 24 weeks' gestation compared with those with free beta human chorionic gonadotropin levels >10 multiples of the median (odds ratio, 7.0; 95% confidence interval, 1.3-36.5; P=.022). A lower free beta human chorionic gonadotropin level was also associated with better early neonatal survival (the median free beta human chorionic gonadotropin level was 9.4 multiples of the median in patients whose child was alive at day 8 vs 20.0 multiples of the median in those whose child was deceased; P=.02). The overall rate of gestational trophoblastic neoplasia after a multiple pregnancy with complete hydatidiform mole and a normal fetus was 26% (35/136; 95% confidence interval, 19-34). All 35 patients had low-risk International Federation of Gynecology and Obstetrics scores, and the cure rate was 100%. Termination of pregnancy on patient request was not associated with lower risk of gestational trophoblastic neoplasia. Maternal complications such as preeclampsia and postpartum hemorrhage were not associated with higher risk of gestational trophoblastic neoplasia, and neither were high human chorionic gonadotropin levels or newborn survival at day 8. CONCLUSION: Multiple pregnancy with complete hydatidiform mole and coexisting fetus carries a high risk of obstetrical complications. In patients who continued their pregnancy, approximately one-third of neonates were alive at day 8, and roughly 1 in 4 patients developed gestational trophoblastic neoplasia. Therefore, the risk of malignant transformation appears to be higher compared with singleton complete moles. Low levels of free beta human chorionic gonadotropin may be indicative of better early neonatal survival, and this relationship warrants further study.

Dose-response relationships of intravenous and perineural dexamethasone as adjuvants to peripheral nerve blocks: a systematic review and model-based network meta-analysis.

BACKGROUND: Superiority of perineural over intravenous dexamethasone at extending nerve block analgesia has been suggested but without considering the dose-response relationships for each route of administration. METHODS: Randomised control studies that evaluated intravenous or perineural dexamethasone as an adjuvant to unilateral peripheral nerve blocks in adults were searched up to October 2023 in MEDLINE, Central, Google Scholar, and reference lists of previous systematic reviews. The Cochrane Risk-of-Bias tool was used. A maximum effect (Emax) model-based network meta-analysis was undertaken to evaluate the dose-response relationships of dexamethasone. RESULTS: A total of 118 studies were selected (9284 patients; 35 with intravenous dexamethasone; 106 with perineural dexamethasone; dose range 1-16 mg). Studies with unclear or high risk of bias overestimated the effect of dexamethasone. Bias-corrected estimates indicated a maximum fold increase in analgesia duration of 1.7 (95% credible interval (CrI) 1.4-1.9) with dexamethasone, with no difference between perineural and intravenous routes. Trial simulations indicated that 4 mg of perineural dexamethasone increased the mean duration of analgesia for long-acting local anaesthetics from 11.1 h (95% CrI 9.4-13.1) to 16.5 h (95% CrI 14.0-19.3) and halved the rate of postoperative nausea and vomiting. A similar magnitude of effect was observed with 8 mg of intravenous dexamethasone. CONCLUSIONS: Used as an adjuvant for peripheral nerve block, intravenous dexamethasone can be as effective as perineural dexamethasone in prolonging analgesic duration, but is less potent, hence requiring higher doses. The evidence is limited because of the observational nature of the dose-response relationships and the quality of the included studies. SYSTEMATIC REVIEW PROTOCOL: PROSPERO CRD42020141689.

Electrochemically Driven Nickel-Catalyzed Halogenation of Unsaturated Halide and Triflate Derivatives.

A robust electrochemically driven nickel-catalyzed halogen exchange of unsaturated halides and triflates (Br to Cl, I to Cl, I to Br, and OTf to Cl) is reported. A combination of NiCl2 ⋅ glyme as the precatalyst, 2,2'-bipyridine as a ligand, NMP as the solvent, and electrochemistry allowed the generation of a nickel species that promotes reductive elimination of the desired product. This paired electrochemical halogenation is compatible with a range of unsaturated halides and triflates, including heterocycles, dihaloarenes, and alkenes with good functional-group tolerance. Joint experimental and theoretical mechanistic investigations highlighted three catalytic events: i) oxidative addition of the aryl halide to a Ni(0) species to deliver a Ni(II) intermediate; ii) halide metathesis at Ni(II); iii) electrochemical oxidation of Ni(II) to Ni(III) to enable the formation of the desired aryl halide upon reductive elimination. This methodology allows the replacement of heavy halogens (I or Br) or polar atoms (O) with the corresponding lighter and more lipophilic Cl group to block undesired reactivity or modify the properties of drug and agrochemical candidates.

Shedding Light on the Hidden Roles of Lithium in the Nickel-Catalyzed Cross-Coupling of Aryl Ethers.

The Ni-catalyzed cross-coupling of aryl ethers is a powerful synthetic tool to transform widely available phenol derivatives into functionalized aromatic molecules. Recent theoretical and experimental mechanistic studies have identified the involvement of heterobimetallic nickelates as key intermediates that facilitate the challenging transformation under mild conditions and often without the need for external ligands or additives. In this work, based on calculations performed at the density functional theory (DFT) level and by comparison with spectroscopic and kinetic data, we investigate the mechanism of the Ni(COD)2-catalyzed cross-coupling of 2-methoxynaphthalene with PhLi and assess the speciation of lithium nickelate intermediates. The crucial role of solvent on the reaction is explained, and the multiple roles played by lithium are unveiled. Experimental studies have identified key lithium nickelate species which support and help to evolve the calculated reaction mechanism and ultimately complete the catalytic cycle. Based on this new mechanistic knowledge, a well-known experimental challenge of these transformations, the so-called "naphthalene problem" which restricts the use of electrophilic coupling partners to π-extended systems, can be addressed to enable the cross-coupling of unbiased aryl ethers under mild conditions.

Molecular Analyses of Chorionic-Type Intermediate Trophoblastic Lesions: Atypical Placental Site Nodules are Closer to Placental Site Nodules Than Epithelioid Trophoblastic Tumors.

Gestational trophoblastic diseases derived from the chorionic-type intermediate trophoblast include benign placental site nodule (PSN) and malignant epithelioid trophoblastic tumor (ETT). Among PSNs, the World Health Organization classification introduced a new entity named atypical placental site nodule (APSN), corresponding to an ETT precursor, for which diagnostic criteria remain unclear, leading to a risk of overdiagnosis and difficulties in patient management. We retrospectively studied 8 PSNs, 7 APSNs, and 8 ETTs to better characterize this new entity and performed immunohistochemical analysis (p63, human placental lactogen, Cyclin E, and Ki67), transcriptional analysis using the NanoString method to quantify the expression of 760 genes involved in the main tumorigenesis pathways, and RNA sequencing to identify fusion transcripts. The immunohistochemical analysis did not reveal any significant difference in Cyclin E expression among the 3 groups (P = .476), whereas the Ki67 index was significantly (P < .001) higher in ETT samples than in APSN and PSN samples. None of the APSN samples harbored the LPCAT1::TERT fusion transcripts, in contrast to 1 of 6 ETT samples, as previously described in 2 of 3 ETT samples. The transcriptomic analysis allowed robust clustering of ETTs distinct from the APSN/PSN group but failed to differentiate APSNs from PSNs. Indeed, only 7 genes were differentially expressed between PSN and APSN samples; CCL19 upregulation and EPCAM downregulation were the most distinguishing features of APSNs. In contrast, 80 genes differentiated ETTs from APSNs, establishing a molecular signature for ETT. Gene set analysis identified significant enrichments in the DNA damage repair, immortality and stemness, and cell cycle signaling pathways when comparing ETTs and APSNs. These results suggested that APSN might not represent a distinct entity but rather a transitional stage between PSN and ETT. RNA sequencing and the transcriptional signature of ETT described herein could serve as triage for APSN from curettage or biopsy material, enabling the identification of cases that need further clinical investigations.

Regime Switch in the Dual-Catalyzed Coupling of Alkyl Silicates with Aryl Bromides.

Metallaphotoredox catalyzed cross-coupling of an arylbromide (Ar-Br) with an alkyl bis(catecholato)silicate (R-Si⊖ ) has been analyzed in depth using a continuum of analytical techniques (EPR, fluorine NMR, electrochemistry, photophysics) and modeling (micro-kinetics and DFT calculations). These studies converged on the impact of four control parameters consisting in the initial concentrations of the iridium photocatalyst ([Ir]0 ), nickel precatalyst ([Ni]0 ) and silicate ([R-Si⊖ ]0 ) as well as light intensity I0 for an efficient reaction between Ar-Br and R-Si⊖ . More precisely, two regimes were found to be possibly at play. The first one relies on an equimolar consumption of Ar-Br with R-Si⊖ smoothly leading to Ar-R, with no side-product from R-Si⊖ and a second one in which R-Si⊖ is simultaneously coupled to Ar-Br and degraded to R-H. This integrative approach could serve as a case study for the investigation of other metallaphotoredox catalysis manifolds of synthetic significance.

Avelumab in patients with gestational trophoblastic tumors with resistance to polychemotherapy: Cohort B of the TROPHIMMUN phase 2 trial.

PURPOSE: There is a need for innovative treatments in women with gestational trophoblastic tumors (GTT) resistant to chemotherapy. The TROPHIMMUN trial assessed the efficacy of avelumab in patients with resistance to single-agent chemotherapy (cohort A), or to polychemotherapy (cohort B). Cohort B outcomes are reported here. METHODS: In the cohort B of this phase 2 multicenter trial (NCT03135769), women with GTT progressing after polychemotherapy received avelumab 10 mg/kg intravenously every 2 weeks until human chorionic gonadotropin (hCG) normalization, followed by 3 consolidation cycles. The primary endpoint was the rate of hCG normalization enabling treatment discontinuation (2-stage Simon design). RESULTS: Between February 2017 and August 2020, 7 patients were enrolled. Median age was 37 years (range: 29-47); disease stage was I or III in 42.9% and 57.1%; FIGO score was 9-10 in 28.6%, 11 in 28.6%, and 16 in 14.3%, respectively. Median follow-up was 18.2 months. One patient (14.3%) experienced hCG normalization enabling treatment discontinuation. However, resistance to avelumab was observed in the remaining 6 patients (85.7%). The cohort B was stopped for futility. Grade 1-2 treatment-related adverse events occurred in 57.1%, most commonly fatigue (42.9%), nausea, diarrhea, infusion-related reaction, muscle pains, dry eyes (each 14.3%). The median resistance-free survival was 1.4 months (95% CI 0.7-5.3). CONCLUSIONS: Although avelumab is active in patients with single-agent chemotherapy-resistant GTT (cohort A), it was associated with limited efficacy in patients with resistance to polychemotherapy (cohort B). The prognosis of patients with polychemotherapy resistance remains poor, and innovative immunotherapy-based therapeutic combinations are needed.

Prognostic impact of cytoreductive surgery conducted with primary intent, versus cytoreductive surgery after neoadjuvant chemotherapy, in the management of patients with advanced epithelial ovarian cancers: a multicentre, propensity score-matched study from the FRANCOGYN group.

OBJECTIVE: To compare survival and morbidity rates between primary cytoreductive surgery (pCRS) and interval cytoreductive surgery (iCRS) for epithelial ovarian cancer (EOC), using a propensity score. DESIGN: We conducted a propensity score-matched cohort study, using data from the FRANCOGYN cohort. SETTING: Retrospective, multicentre study of data from patients followed in 15 French department specialized in the treatment of ovarian cancer. SAMPLE: Patients included were those with International Federation of Gynaecology and Obstetrics (FIGO) stage III or IV EOC, with peritoneal carcinomatosis, having undergone CRS. METHODS: The propensity score was designed using pre-therapeutic variables associated with both treatment allocation and overall survival (OS). MAIN OUTCOME MEASURES: The primary outcome was OS. Secondary outcomes included recurrence-free survival (RFS), quality of CRS and other variables related to surgical morbidity. RESULTS: A total of 513 patients were included. Among these, 334 could be matched, forming 167 pairs. No difference in OS was found (hazard ratio, HR = 0.8, p = 0.32). There was also no difference in RFS (median = 26 months in both groups) nor in the rate of CRS leaving no macroscopic residual disease (pCRS 85%, iCRS 81.4%, p = 0.76). The rates of gastrointestinal tract resections, stoma, postoperative complications and hospital stay were significantly higher in the pCRS group. CONCLUSIONS: Analysis of groups of patients made comparable by propensity score matching showed no difference in survival, but lower postoperative morbidity in patients treated with iCRS.

European multidisciplinary tumor boards support cross-border networking and increase treatment options for patients with rare gynecological tumors.

OBJECTIVE: To evaluate outcomes of European cross-border multidisciplinary tumor boards in terms of participation, adherence to treatment recommendations, and access to novel treatment strategies. METHODS: The European reference network for rare gynecological tumors (EURACAN G2 domain) aims to improve the diagnosis, management, and treatment of patients with these cancers. Cross-border multidisciplinary tumor boards were initiated to facilitate intercollegiate clinical discussions across Europe and increase patients' access to specialist treatment recommendations and clinical trials. All G2 healthcare providers were invited to participate in monthly multidisciplinary meetings. Patient data were collected using a standardized form and case summaries were distributed before each meeting. After each tumor board, a meeting summary with treatment recommendations was sent to all participants and the project manager at the coordinating center. The multidisciplinary tumor board format and outcomes were regularly discussed at G2 domain meetings. Anonymized clinical data and treatment recommendations were registered in a prospective database. For this report, clinical data were collected between November 2017 and December 2020 and follow-up data retrieved until May 2021. RESULTS: During the 3-year period, 31 multidisciplinary tumor boards were held with participants from 10 countries and 20 centers. 91 individual patients were discussed between one and six times for a total of 109 case discussions. Follow-up data were retrieved from 64 patients and 80 case discussions. Adherence to treatment recommendations was 99%. Multidisciplinary tumor board recommendations resulted in 11 patients getting access to off-label treatment and one patient being enrolled in a clinical trial in another European country. 14/91 patients were recommended for surveillance only when additional treatment had been considered locally. CONCLUSION: Cross-border multidisciplinary tumor boards enable networking and clinical collaboration between healthcare professionals in different countries. Surveillance strategies, off-label drug use, and increased participation in clinical trials are possible benefits to patients with rare gynecological tumors.

Non-Hermitian Hamiltonians for linear and nonlinear optical response: A model for plexcitons.

In polaritons, the properties of matter are modified by mixing the molecular transitions with light modes inside a cavity. Resultant hybrid light-matter states exhibit energy level shifts, are delocalized over many molecular units, and have a different excited-state potential energy landscape, which leads to modified exciton dynamics. Previously, non-Hermitian Hamiltonians have been derived to describe the excited states of molecules coupled to surface plasmons (i.e., plexcitons), and these operators have been successfully used in the description of linear and third order optical response. In this article, we rigorously derive non-Hermitian Hamiltonians in the response function formalism of nonlinear spectroscopy by means of Feshbach operators and apply them to explore spectroscopic signatures of plexcitons. In particular, we analyze the optical response below and above the exceptional point that arises for matching transition energies for plasmon and molecular components and study their decomposition using double-sided Feynman diagrams. We find a clear distinction between interference and Rabi splitting in linear spectroscopy and a qualitative change in the symmetry of the line shape of the nonlinear signal when crossing the exceptional point. This change corresponds to one in the symmetry of the eigenvalues of the Hamiltonian. Our work presents an approach for simulating the optical response of sublevels within an electronic system and opens new applications of nonlinear spectroscopy to examine the different regimes of the spectrum of non-Hermitian Hamiltonians.

Immunotherapy for GTN: a new paradigm.

Background Immune checkpoint immunotherapy (CPI) targeting PD1/PD-L1 has been shown to be an effective treatment for gestational trophoblastic neoplasia (GTN). This includes those with multidrug resistance, ultra-high risk disease and ETT/PSTT subtypes that are inherently chemotherapy resistant, but there is also emerging evidence in low-risk disease. Objectives We set out to generate an overview of the current data supporting the use of CPI for GTN in both high risk and low risk disease and to consider future research goals and directions in order to implement CPI in current treatment guidelines. Methods We identified and reviewed the published data on the use of CPI agents in GTN. Outcome 133 patients were identified who had been treated with CPI for GTN with pembrolizumab (23), avelumab (22), camrelizumab (57), toripalimab (15) or other anti-PD-1 agents (16), of whom 118 had high risk disease, relapse or multi drug resistant disease, and 15 low risk disease. Overall 85 patients achieved complete remission, 77 (of 118) with high risk disease and 8 (of 15) with low risk disease. 1 patient with complete remission in the high risk group developed a relapse 22 months after anti-PD-1 treatment had been stopped. Treatment was generally well tolerated across studies. Conclusions and Outlook The majority of high risk patients (77/118) treated with CPI are cured and this is particularly relevant amongst those with chemotherapy resistant disease who otherwise have very limited treatment options. Priorities for future research include determining whether these agents have a role earlier in the disease course, the utility of combination with chemotherapy, and effects on future fertility. Treatment availability remains a concern due to the high price of these agents.

Management of patients with advanced epithelial ovarian cancer: a European survey.

BACKGROUND: The aim of this study was to assess current European practices in the management of patients with advanced epithelial ovarian cancer in 2021. METHODS: A 58-question electronic survey was distributed anonymously to the members of six European learned societies. Initial diagnostic workup and staging, pathological data, surgical data, treatments and follow-up strategies were assessed. RESULTS: A total of 171 participants from 17 European countries responded to emailed surveys. Most participants were experienced practitioners (superior than 15 years of experience) specializing in gynecology-obstetrics (29.8%), surgical oncology (25.1%), and oncogynecology (21.6%). According to most (64.8%) participants, less than 50% of patients were eligible for primary debulking surgery. Variations in the rate of primary debulking surgery depending on the country of origin of the practitioners were observed in this study. The LION study criteria were applied in 70.4% of cases during PDS and 27.1% after chemotherapy. In cases of BRCA1-2 mutations, olaparib was given by 75.0-84.8% of respondents, whereas niraparib was given in cases of BRCA wild-type diseases. CONCLUSIONS: This study sheds light on current practices and attitudes regarding the management of patients with advanced epithelial ovarian cancer in Europe in 2021.

Lithium Promotes Acetylide Formation on MgO During Methane Coupling Under Non-Oxidative Conditions.

A prototypical material for the oxidative coupling of methane (OCM) is Li/MgO, for which Li is known to be essential as a dopant to obtain high C2 selectivities. Herein, Li/MgO is demonstrated to be an effective catalyst for non-oxidative coupling of methane (NOCM). Moreover, the presence of Li is shown to favor the formation of magnesium acetylide (MgC2 ), while pure MgO promotes coke formation as evidenced by solid-state 13 C NMR, thus indicating that Li promotes C-C bond formation. Metadynamic simulations of the carbon mobility in MgC2 and Li2 C2 at the density functional theory (DFT) level show that carbon easily diffuses as a C2 unit at 1000 °C. These insights suggest that the enhanced C2 selectivity for Li-doped MgO is related to the formation of Li and Mg acetylides.

A Robust and Efficient Propane Dehydrogenation Catalyst from Unexpectedly Segregated Pt2Mn Nanoparticles.

The increasing demand for short chain olefins like propene for plastics production and the availability of shale gas make the development of highly performing propane dehydrogenation (PDH) catalysts, robust toward industrially applied harsh regeneration conditions, a highly important field of research. A combination of surface organometallic chemistry and thermolytic molecular precursor approach was used to prepare a nanometric, bimetallic Pt-Mn material (3 wt % Pt, 1.3 wt % Mn) supported on silica via consecutive grafting of a Mn and Pt precursor on surface OH groups present on the support surface, followed by a treatment under a H2 flow at high temperature. The material exhibits a 70% fraction of the overall Mn as MnII single sites on the support surface; the remaining Mn is incorporated in segregated Pt2Mn nanoparticles. The material shows great performance in PDH reaction with a low deactivation rate. In particular, it shows outstanding robustness during repeated regeneration cycles, with conversion and selectivity stabilizing at ca. 37 and 98%, respectively. Notably, a material with a lower Pt loading of only 0.05 wt % shows an outstanding catalytic performance─initial productivity of 4523 gC3H6/gPt h and an extremely low kd of 0.003 h-1 under a partial pressure of H2, which are among the highest reported productivities. A combined in situ X-ray absorption spectroscopy, scanning transmission electron microscopy, electron paramagnetic resonance, and metadynamics at the density functional theory level study could show that the strong interaction between the MnII-decorated support and the unexpectedly segregated Pt2Mn particles is most likely responsible for the outstanding performance of the investigated materials.

Impact of vulvar reconstruction on the accuracy of a nomogram for predicting local recurrence after surgery for vulvar cancer.

BACKGROUND DATA: Vulvar carcinoma is a rare disease accounting for 3%-5% of all gynaecological cancers. Although surgery is the standard treatment at an early stage, the outcomes are highly correlated with clear resection margins. Therefore, surgical defects can be important and require reconstruction. The aim of this study was to evaluate vulvar reconstructions using a previously validated nomogram predicting the risk of local recurrence at 2 years. METHODS: Patients who underwent surgery for vulvar cancer between 1998 and 2017 were extracted from eight FRANCOGYN centres. We estimated the probability of local recurrence at 2 years using a previously validated nomogram and compared it with actual relapse in patients with or without vulvar reconstruction. Patients were clustered into tiertiles according to their nomogram score: low-, intermediate-, and high-risk for local relapse probability. RESULTS: We reviewed 254 patients, of whom 49 underwent immediate vulvar reconstruction. The predicted and actual probability of two-year local relapse were 20.1% and 15.7%, respectively, with a concordance index of 0.75. In the low- and intermediate-risk groups, the difference between predicted and observed recurrence was less than 10% in patients with or without vulvar reconstruction. For the high-risk group, the difference reached 25% and observed recurrence probability was lower in patients who underwent vulvar plasty compared with those who did not (20.0% vs. 36.2%, respectively). Local recurrence-free survival rates following vulvar reconstruction were comparable at two years (82.1% vs. 84.8%, respectively, p = 0.26). CONCLUSION: Vulvar reconstruction after surgical resection for vulvar cancer is safe. Vulvar reconstruction should be considered in aggressive cases to decrease local recurrence.

Salt-Enhanced Oxidative Addition of Iodobenzene to Pd: An Interplay Between Cation, Anion, and Pd-Pd Cooperative Effects.

Halide salts facilitate the oxidative addition of organic halides to Pd(0). This phenomenon originates from a combination of anionic, cationic, and Pd-Pd cooperative effects. Exhaustive computational exploration at the density functional theory level of the complexes obtained from [Pd0(PPh3)2] and a salt (NMe4Cl or LiCl) showed that chlorides promote phosphine release, leading to a mixture of mononuclear and dinuclear Pd(0) complexes. Anionic Pd(0) dinuclear complexes exhibit a cooperativity between Pd(0) centers, which favors the oxidative addition of iodobenzene. The higher activity of Pd(0) dimers toward oxidative addition rationalizes the previously reported kinetic laws. In the presence of Li+, the oxidative addition to mononuclear [Pd0L(Li2Cl2)] is estimated barrierless. LiCl coordination polarizes Pd(0), enlarging both the electrophilicity and the nucleophilicity of the complex, which promotes both coordination of the substrate and the subsequent insertion into the C-I bond. These conclusions are paving the way to the rational use of the salt effects in catalysis for the activation of more challenging bonds.

Outcomes after acute coronary syndrome in patients with inflammatory bowel disease.

BACKGROUND: Patients with chronic inflammatory conditions are at an increased risk of developing atherothrombotic events. We aimed to assess the 1-year prognosis after myocardial infarction (MI) in patients with inflammatory bowel disease (IBD). METHODS: From the PMSI (Program de Medicalisation des Systèmes d'informatique) database, 246 out of 39,835 consecutive MI patients, hospitalized between 2012 and 2017, were diagnosed with IBD and followed up for 1 year after discharge. A matched cohort was built matching each MI patient with IBD to patient without IBD using age and sex (n = 1,470, matching ratio 1:5). RESULTS: Compared with MI patients without IBD, MI patients with IBD were younger (aged 69 vs. 70.8 years, p = 0.04) with a higher rate of increased body mass index (BMI) (21.5% vs 15%, p = 0.004), previously diagnosed ischemic cardiopathy (18.3% vs 12.6%, p < 0.0008) and chronic renal disease (8.9% vs 5.6%, p = 0.02). In our age- and sex-matched cohort, we found that all-cause mortality (9% vs 8.3, p = 0.729), stroke (0.8% vs 0.6%, p = 0.656) and hospitalization resulting from heart failure (3ool, .3% vs 3.5%, p = 0.846) did not significantly differ between the IBD and non-IBD groups within the first year after initial admission whereas the risk of recurrent MI was increased by 50% (2.9% vs 1.9%, p = 0.33) in the IBD group without reaching statistical significance. Moreover, a significant increase in the blood transfusion rate at the 1-year follow-up was observed in MI patients with IBD compared with MI patients without IBD (15.1% vs 9.4%, p < 0.001). CONCLUSION: Our findings suggest that both residual MI risk and bleeding events should be carefully monitored in MI patients diagnosed with chronic inflammation such as that observed in IBD.

Heterogeneous alkane dehydrogenation catalysts investigated via a surface organometallic chemistry approach.

The selective conversion of light alkanes (C2-C6 saturated hydrocarbons) to the corresponding alkene is an appealing strategy for the petrochemical industry in view of the availability of these feedstocks, in particular with the emergence of Shale gas. Here, we present a review of model dehydrogenation catalysts of light alkanes prepared via surface organometallic chemistry (SOMC). A specific focus of this review is the use of molecular strategies for the deconvolution of complex heterogeneous materials that are proficient in enabling dehydrogenation reactions. The challenges associated with the proposed reactions are highlighted, as well as overriding themes that can be ascertained from the systematic study of these challenging reactions using model SOMC catalysts.

Copper-Catalyzed Homocoupling of Boronic Acids: A Focus on B-to-Cu and Cu-to-Cu Transmetalations.

Controlling and understanding the Cu-catalyzed homocoupling reaction is crucial to prompt the development of efficient Cu-catalyzed cross-coupling reactions. The presence of a coordinating base (hydroxide and methoxide) enables the B-to-Cu(II) transmetalation from aryl boronic acid to CuIICl2 in methanol, through the formation of mixed Cu-(µ-OH)-B intermediates. A second B-to-Cu transmetalation to form bis-aryl Cu(II) complexes is disfavored. Instead, organocopper(II) dimers undergo a coupled transmetalation-electron transfer (TET) allowing the formation of bis-organocopper(III) complexes readily promoting reductive elimination. Based on this mechanism some guidelines are suggested to control the undesired formation of homocoupling product in Cu-catalyzed cross-coupling reactions.