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Purpose of Review: The management of histologically benign central airway obstruction (CAO) is complex. Published studies have focused on the diagnostic approaches and therapeutic options provided by specific specialties, but there has been no focus on multidisciplinary management of this disease. Our objective is to review the current diagnostic and therapeutic modalities available for managing nonmalignant CAO from a multidisciplinary perspective involving otolaryngology, thoracic surgery and interventional bronchoscopists., Recent Findings: For benign airway strictures, management is via medical and endoscopic therapy with surgical resection reserved for complex and recurrent stenoses. There is evidence and growing interest in intralesional corticosteroid injection in treating inflammation and potentially preventing recurrence. Airway specialists from distinct disciplines use different laser types, dilating balloons and anesthesia methods to manage benign CAO. Recent studies have demonstrated substantial improvements in patient breathlessness and quality of life following therapeutic airway interventions, highlighting the evolving landscape in this cross-disciplinary field., Summary: Nonmalignant CAO, arising from various mechanical, inflammatory, and infectious etiologies, poses significant morbidity and mortality risks. Current treatments include endoscopic resection, dilation, stent placement, and surgical resection which are selected based on lesion's complexity, extent, operability and patient's symptoms and goals. A multimodal and multidisciplinary approach to patient care could offer the best outcomes., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Background and Objective: Interstitial lung diseases (ILDs) encompass over 200 entities. Among them, fibrosing lung diseases, have recently generated special interest due to the emerging therapies for their management. However, it is important to deepen our knowledge of other less prevalent ILD, since many of them are associated with a poor prognosis. This narrative review aims to provide a practical and up-to-date description of some poorly recognized ILD. It covers rare idiopathic interstitial pneumonias and their histologic patterns, genetic disorders with interstitial lung involvement (Hermansky-Pudlak syndrome), and ILD associated with benign proliferation of pulmonary lymphoid tissue, namely follicular bronchiolitis and granulomatous-lymphocytic interstitial lung disease., Methods: Electronic searches of PubMed and Google Scholar using specific keywords were conducted. Articles underwent screening for relevance, covering review articles, meta-analyses, systematic reviews, case series, prospective studies, society guidelines, editorials in peer-reviewed journals; scientific books on the subject. The data included was limited to English and Spanish publications., Key Content and Findings: Despite the low prevalence of these diseases, the increased recognition of radiological patterns, pathological features, and diagnostic procedures, have permitted their better characterization. This review highlights epidemiology, clinical presentation, diagnosis, natural history, and treatment., Conclusions: Lesser-studied ILD represent a diagnostic and therapeutic challenge and can be frequently misdiagnosed. Also, due to the lack of randomized controlled trials, there are no well-established therapeutic options. Further studies or registries are needed to improve accurate diagnosis and management., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-24-450/coif). The authors have no conflicts of interest to declare., (2024 AME Publishing Company. All rights reserved.)

A series of six Mn(I) complexes with general formula [MnBr(bisNHC)(CO) 3 ], having a bidentate bis(N-heterocyclic carbene) ligand (bisNHC), has been developed by varying the bridging group between the NHC donors, the nitrogen wingtip substituents and the heterocyclic ring. The synthesis of the complexes has been accomplished by in situ transmetalation of the bisNHC from the corresponding silver(I) complexes. Removal of the bromide anion affords the corresponding solvento complexes [Mn(bisNHC)(CO) 3 (CH 3 CN)](BF 4 ). The influence of the bisNHC structure on its electron donor ability has been evaluated by FTIR and 13 C NMR spectroscopy, both in the neutral and cationic complexes. Finally, the isolated Mn(I)-bisNHC complexes have been employed as homogeneous catalysts in the reductive N-formylation and N-methylation of amines with CO 2 as C1 source and phenylsilane as reducing agent, showing a high selectivity for the N-methylated product. Preliminary mechanistic investigations suggest that, in the adopted reaction conditions, the formylated product can be formed via different reaction pathways, either metal-catalyzed or not, while the methylation reaction requires the use of the Mn(I) catalyst., (© 2023 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

Background: Antimicrobial resistance is one of the most pressing health issues of our time. The increase in the number of antibiotic-resistant bacteria allied to the lack of new antibiotics has contributed to the current crisis. It has been predicted that if this situation is not dealt with, we will be facing 10 million deaths due to multidrug resistant infections per year by 2050, surpassing cancer-related deaths. This alarming scenario has refocused attention into researching alternative drugs to treat multidrug-resistant infections., Aims: In this study, the antimicrobial activities of four manganese complexes containing 1,2,3,-triazole and clotrimazole ligands have been evaluated. It is known that azole antibiotics coordinated to manganese tricarbonyl complexes display interesting antimicrobial activities against several microbes. In this work, the effect of the introduction of 1,2,3,-triazole-derived ligands in the [Mn(CO) 3 (clotrimazole)] fragment has been investigated against one Gram-positive bacterium and five Gram-negative bacteria., Methods: The initial antimicrobial activity of the above-mentioned complexes was assessed by determining the minimum inhibitory and bactericidal concentrations using the broth microdilution method. Growth curves in the presence and absence of the complexes were performed to determine the effects of these complexes on the growth of the selected bacteria. A possible impact on cellular viability was determined by conducting the MTS assay on human monocytes., Results: Three of the Mn complexes investigated ( 4 - 6 ) had good antimicrobial activities against all the bacteria tested, with values ranging from 1.79 to 61.95 µM with minimal toxicity., Conclusions: Due to the increased problem of antibiotic resistance and a lack of new antibacterial drugs with no toxicity, these results are exciting and show that these types of complexes can be an avenue to pursue in the future.

Ruthenium(II) arene complexes exhibit promising chemotherapeutic properties. In this study, the effect of the counter anion in Ru(II) complexes was evaluated by analyzing the biological effect of two Ru(II) p -cymene derivatives with the 1,10-phenanthroline-5,6-dione ligand of general-formula [(η 6 -arene)Ru(L)Cl][X] X = CF 3 SO 3 (JHOR10) and PF 6 (JHOR11). The biological activity of JHOR10 and JHOR11 was examined in the ovarian carcinoma cell line A2780, colorectal carcinoma cell line HCT116, doxorubicin-resistant HCT116 (HCT116-Dox) and in normal human dermal fibroblasts. Both complexes JHOR10 and JHOR11 displayed an antiproliferative effect on A2780 and HCT116 cell lines, and low cytotoxicity in fibroblasts. Interestingly, JHOR11 also showed antiproliferative activity in the HCT116-Dox cancer cell line, while JHOR10 was inactive. Studies in A2780 cells showed that JHOR11 induced the production of reactive oxygen species (ROS) that trigger autophagy and cellular senescence, but no apoptosis induction. Further analysis showed that JHOR11 presented no tumorigenicity, with no effect in the cellular mobility, as evaluated by thye wound scratch assay, and no anti- or pro-angiogenic effect, as evaluated by the ex-ovo chorioallantoic membrane (CAM) assay. Importantly, JHOR11 presented no toxicity in chicken and zebrafish embryos and reduced in vivo the proliferation of HCT116 injected into zebrafish embryos. These results show that these are suitable complexes for clinical applications with improved tumor cell cytotoxicity and low toxicity, and that counter-anion alteration might be a viable clinical strategy for improving chemotherapy outcomes in multidrug-resistant (MDR) tumors.

The ornithine-urea cycle (urea cycle) makes a significant contribution to the metabolic responses of lower photosynthetic eukaryotes to episodes of high nitrogen availability. In this study, we compared the role of the plant urea cycle and its relationships to polyamine metabolism in ammonium-fed and nitrate-fed Medicago truncatula plants. High ammonium resulted in the accumulation of ammonium and pathway intermediates, particularly glutamine, arginine, ornithine, and putrescine. Arginine decarboxylase activity was decreased in roots, suggesting that the ornithine decarboxylase-dependent production of putrescine was important in situations of ammonium stress. The activity of copper amine oxidase, which releases ammonium from putrescine, was significantly decreased in both shoots and roots. In addition, physiological concentrations of ammonium inhibited copper amine oxidase activity in in vitro assays, supporting the conclusion that high ammonium accumulation favors putrescine synthesis. Moreover, early supplementation of plants with putrescine avoided ammonium toxicity. The levels of transcripts encoding urea-cycle-related proteins were increased and transcripts involved in polyamine catabolism were decreased under high ammonium concentrations. We conclude that the urea cycle and associated polyamine metabolism function as important protective mechanisms limiting ammonium toxicity in M. truncatula. These findings demonstrate the relevance of the urea cycle to polyamine metabolism in higher plants., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Society for Experimental Biology.)

Several metal-based carbon monoxide-releasing molecules (CORMs) are active CO donors with established antibacterial activity. Among them, CORM conjugates with azole antibiotics of type [Mn(CO) 3 (2,2'-bipyridyl)(azole)] + display important synergies against several microbes. We carried out a structure-activity relationship study based upon the lead structure of [Mn(CO) 3 (Bpy)(Ctz)] + by producing clotrimazole (Ctz) conjugates with varying metal and ligands. We concluded that the nature of the bidentate ligand strongly influences the bactericidal activity, with the substitution of bipyridyl by small bicyclic ligands leading to highly active clotrimazole conjugates. On the contrary, the metal did not influence the activity. We found that conjugate [Re(CO) 3 (Bpy)(Ctz)] + is more than the sum of its parts: while precursor [Re(CO) 3 (Bpy)Br] has no antibacterial activity and clotrimazole shows only moderate minimal inhibitory concentrations, the potency of [Re(CO) 3 (Bpy)(Ctz)] + is one order of magnitude higher than that of clotrimazole, and the spectrum of bacterial target species includes Gram-positive and Gram-negative bacteria. The addition of [Re(CO) 3 (Bpy)(Ctz)] + to Staphylococcus aureus causes a general impact on the membrane topology, has inhibitory effects on peptidoglycan biosynthesis, and affects energy functions. The mechanism of action of this kind of CORM conjugates involves a sequence of events initiated by membrane insertion, followed by membrane disorganization, inhibition of peptidoglycan synthesis, CO release, and break down of the membrane potential. These results suggest that conjugation of CORMs to known antibiotics may produce useful structures with synergistic effects that increase the conjugate's activity relative to that of the antibiotic alone., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

The antiproliferative activity of [Mn(CO) 3 (N^N)Br] (N^N = phendione 1, bipy 3) and of the two newly synthesized Mn complexes [Mn(CO) 3 (acridine)(phendione)]OTf (2) and [Mn(CO) 3 (di-triazole)Br] (4) has been evaluated by MTS against three tumor cell lines A2780 (ovarian carcinoma), HCT116 (colorectal carcinoma), HCT116doxR (colorectal carcinoma resistant to doxorubicin), and in human dermal fibroblasts. The antiproliferative assay showed a dose-dependent effect higher in complex 1 and 2 with a selectivity toward ovarian carcinoma cell line 21 times higher than in human fibroblasts. Exposure of A2780 cells to IC 50 concentrations of complex 1 and 2 led to an increase of reactive oxygen species that led to the activation of cell death mechanisms, namely via intrinsic apoptosis for 2 and autophagy and extrinsic apoptosis for 1. Both complexes do not target DNA or interfere with cell cycle progression but are able to potentiate cell migration and neovascularization (for 2) an indicative that their application might be directed for initial tumor stages to avoid tumor invasion and metastization and opening a new avenue for complex 2 application in regenerative medicine. Interestingly, both complexes do not show toxicity in both in vivo models (CAM and zebrafish)., (© 2021. The Author(s), under exclusive licence to Society for Biological Inorganic Chemistry (SBIC).)

A series of new fac -[Mn(L)(CO) 3 Br] complexes where L is a bidentate chelating ligand containing mixed mesoionic triazolylidene-pyridine (MIC^py, 1 ), triazolylidene-triazole (MIC^trz, 2 ), and triazole-pyridine (trz^py, 3 ) ligands have been prepared and fully characterized, including the single crystal X-ray diffraction studies of 1 and 2 . The abilities of 1 - 3 and complex fac -[Mn(MIC^MIC)(CO) 3 Br] ( 4 ) to catalyze the electroreduction of CO 2 has been assessed for the first time. It was found that all complexes displayed a current increase under CO 2 atmosphere, being 3 and 4 the most active complexes. Complex 3 , bearing a N^N-based ligand exhibited a good efficiency and an excellent selectivity for reducing CO 2 to CO in the presence of 1.0 M of water, at low overpotential. Interestingly, complex 4 containing the strongly electron donating di-imidazolylidene ligand exhibited comparable activity to 3 , when the experiments were performed in neat acetonitrile at slightly higher overpotential (-1.86 vs. -2.14 V).

Cisplatin and its derivatives are commonly used in chemotherapeutic treatments of cancer, even though they suffer from many toxic side effects. The problems that emerge from the use of these metal compounds led to the search for new complexes capable to overcome the toxic side effects. Here, we report the evaluation of the antiproliferative activity of Fe(II) cyclopentadienyl complexes bearing n -heterocyclic carbene ligands in tumour cells and their in vivo toxicological profile. The in vitro antiproliferative assays demonstrated that complex Fe1 displays the highest cytotoxic activity both in human colorectal carcinoma cells (HCT116) and ovarian carcinoma cells (A2780) with IC 50 values in the low micromolar range. The antiproliferative effect of Fe1 was even higher than cisplatin. Interestingly, Fe1 showed low in vivo toxicity, and in vivo analyses of Fe1 and Fe2 compounds using colorectal HCT116 zebrafish xenograft showed that both reduce the proliferation of human HCT116 colorectal cancer cells in vivo.

Background: The role of bronchoscopy in coronavirus disease 2019 (COVID-19) is a matter of debate., Patients and Methods: This observational multicentre study aimed to analyse the prognostic impact of bronchoscopic findings in a consecutive cohort of patients with suspected or confirmed COVID-19. Patients were enrolled at 17 hospitals from February to June 2020. Predictors of in-hospital mortality were assessed by multivariate logistic regression., Results: A total of 1027 bronchoscopies were performed in 515 patients (age 61.5±11.2 years; 73% men), stratified into a clinical suspicion cohort (n=30) and a COVID-19 confirmed cohort (n=485). In the clinical suspicion cohort, the diagnostic yield was 36.7%. In the COVID-19 confirmed cohort, bronchoscopies were predominantly performed in the intensive care unit (n=961; 96.4%) and major indications were: difficult mechanical ventilation (43.7%), mucus plugs (39%) and persistence of radiological infiltrates (23.4%). 147 bronchoscopies were performed to rule out superinfection, and diagnostic yield was 42.9%. There were abnormalities in 91.6% of bronchoscopies, the most frequent being mucus secretions (82.4%), haematic secretions (17.7%), mucus plugs (17.6%), and diffuse mucosal hyperaemia (11.4%). The independent predictors of in-hospital mortality were: older age (OR 1.06; p<0.001), mucus plugs as indication for bronchoscopy (OR 1.60; p=0.041), absence of mucosal hyperaemia (OR 0.49; p=0.041) and the presence of haematic secretions (OR 1.79; p=0.032)., Conclusion: Bronchoscopy may be indicated in carefully selected patients with COVID-19 to rule out superinfection and solve complications related to mechanical ventilation. The presence of haematic secretions in the distal bronchial tract may be considered a poor prognostic feature in COVID-19., Competing Interests: Conflict of interest: M. Arenas-De Larriva reports a travel grant from Novartis and lecture fees from Ferrer outside the submitted work. Conflict of interest: R. Martín-DeLeon has nothing to disclose. Conflict of interest: B. Urrutia Royo has nothing to disclose. Conflict of interest: I. Fernández-Navamuel has nothing to disclose. Conflict of interest: A. Gimenez Velando has nothing to disclose. Conflict of interest: L. Nuñez García has nothing to disclose. Conflict of interest: C. Centeno Clemente has nothing to disclose. Conflict of interest: F. Andreo García has nothing to disclose. Conflict of interest: A. Rafecas Codern has nothing to disclose. Conflict of interest: C. Fernández-Arias has nothing to disclose. Conflict of interest: V. Pajares Ruiz has nothing to disclose. Conflict of interest: A. Torrego Fernández has nothing to disclose. Conflict of interest: O. Rajas has nothing to disclose. Conflict of interest: G. Iturricastillo has nothing to disclose. Conflict of interest: R. Garcia Lujan has nothing to disclose. Conflict of interest: L. Comeche Casanova has nothing to disclose. Conflict of interest: A. Sánchez-Font has nothing to disclose. Conflict of interest: R. Aguilar-Colindres has nothing to disclose. Conflict of interest: R. Larrosa-Barrero has nothing to disclose. Conflict of interest: R. García García has nothing to disclose. Conflict of interest: R. Cordovilla has nothing to disclose. Conflict of interest: A. Núñez-Ares has nothing to disclose. Conflict of interest: A. Briones-Gómez has nothing to disclose. Conflict of interest: E. Cases Viedma reports lecture fees from Ambu outside the submitted work. Conflict of interest: J. Franco has nothing to disclose. Conflict of interest: J. Cosano Povedano reports a travel grant from Izasa scientific outside the submitted work. Conflict of interest: M.L. Rodríguez-Perálvarez reports lecture fees from Novartis, Astellas and Intercept outside the submitted work. Conflict of interest: J.J. Cebrian Gallardo has nothing to disclose. Conflict of interest: M. Nuñez Delgado has nothing to disclose. Conflict of interest: M. Pavón-Masa has nothing to disclose. Conflict of interest: M. Valdivia Salas has nothing to disclose. Conflict of interest: J. Flandes has nothing to disclose., (Copyright ©The authors 2021.)

In this work, an environment-friendly enzymatic strategy was developed for the valorisation of dye-containing wastewaters. We set up biocatalytic processes for the conversion of azo dyes representative of the main classes used in the textile industry into valuable aromatic compounds: aromatic amines, phenoxazinones, phenazines, and naphthoquinones. First, purified preparations of PpAzoR azoreductase efficiently reduced mordant, acid, reactive, and direct azo dyes into aromatic amines, and CotA-laccase oxidised these compounds into phenazines, phenoxazinones, and naphthoquinones. Second, whole cells containing the overproduced enzymes were utilised in the two-step enzymatic conversion of the model mordant black 9 dye into sodium 2-amino-3-oxo-3 H -phenoxazine-8-sulphonate, allowing to overcome the drawbacks associated with the use of expensive purified enzymes, co-factors, or exquisite reaction conditions. Third, cells immobilised in sodium alginate allowed recycling the biocatalysts and achieving very good to excellent final phenoxazine product yields (up to 80%) in water and with less impurities in the final reaction mixtures. Finally, one-pot systems using recycled immobilised cells co-producing both enzymes resulted in the highest phenoxazinone yields (90%) through the sequential use of static and stirring conditions, controlling the oxygenation of reaction mixtures and the successive activity of azoreductase (anaerobic) and laccase (aerobic)., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Fernandes, Pinto, Bonardo, Royo, Robalo and Martins.)

A new series of half-sandwich ruthenium(II) compounds [(η 6 -arene)Ru(L)Cl][CF 3 SO 3 ] bearing 1,2,3-triazole ligands (arene = p -cymene, L = L1 ( 1 ); arene = p -cymene, L = L2 ( 2 ); arene = benzene, L = L1 ( 3 ); arene = benzene, L2 ( 4 ); L1 = 2-[1-( p -tolyl)-1 H -1,2,3-triazol-4-yl]pyridine and L2 = 1,1'-di- p -tolyl-1 H ,1' H -4,4'-bi(1,2,3-triazole) have been synthesized and fully characterized by 1 H and 13 C NMR and IR spectroscopy, mass spectrometry, and elemental analysis. The molecular structures of 1 , 2 , and 4 have been determined by single-crystal X-ray diffraction. The cytotoxic activity of 1 - 4 was evaluated using the MTS assay against human tumor cells, namely ovarian carcinoma (A2780), colorectal carcinoma (HCT116), and colorectal carcinoma resistant to doxorubicin (HCT116dox), and against normal primary fibroblasts. Whereas compounds 2 and 4 showed no cytotoxic activity toward tumor cell lines, compounds 1 and 3 were active in A2780, while showing no antiproliferative effect in human normal dermal fibroblasts at the IC 50 concentrations of the A2780 cell line. Exposure of ovarian carcinoma cells to IC 50 concentrations of compound 1 or 3 led to an accumulation of reactive oxygen species and an increase of apoptotic and autophagic cells. While compound 3 displayed low levels of angiogenesis induction, compound 1 showed an ability to induce cell cycle delay and to interfere with cell migration. When the in vivo toxicity studies using zebrafish and chicken embryos are considered, compounds 1 and 3 , which were not lethal, are promising candidates as anticancer agents against ovarian cancer due to their good cytotoxic activity in tumor cells and their low toxicity both in vitro and in vivo .

New manganese complexes bearing di-triazolylidene (di-trz) ligands are described. Depending on the wingtip substituents of the triazolylidene ligand and the synthetic procedure, two different ligand coordination modes were observed, i.e, bridging and chelating. A series of Mn(i) complexes of the general type fac-[Mn(di-trzR)(CO)3Br] (R = Me, Et, Mes) with a chelating di-trz ligand were prepared via Ag-transmetalation. In contrast, the in situ deprotonation of the triazolium salts with KOBut yielded the bimetallic Mn(0) complexes [Mn2(CO)8(μ-di-trzR)] with a bridging di-trz ligand when short alkyl chains (Me, Et, i-Pr) are present as the N1 substituents of the triazolylidene ligand. The molecular structures of monometallic and bimetallic complexes were determined by X-ray diffraction studies. In addition, the cationic fac-[Mn(di-trzEt)(CO)2(PPh3)2]Br complex, a rare example of a dicarbonyl Mn(i) N-heterocyclic carbene, was obtained when fac-[Mn(di-trzEt)(CO)3Br] was irradiated with visible light in the presence of PPh3. The crystal structure revealed a slightly distorted octahedral geometry around the Mn(i) centre, with the chelating di-triazolylidene ligand situated in trans position to the two CO ligands in the equatorial plane, and the two phosphine ligands occupying the axial positions. Cyclic voltammetry studies show reversible redox processes for the monometallic Mn(i) complexes, and a quasi-reversible EC mechanism for the oxidation of the bimetallic complexes. Infrared spectroelectrochemical studies along with DFT calculations for fac-[Mn(di-trzEt)(CO)3Br] suggest that the observed two consecutive reductions both occur at the metal centre.

Background: Eosinophilic granulomatosis with polyangiitis (EGPA) is a disease that is associated with severe uncontrolled eosinophilic asthma. Eosinophils play an important pathogenic role in the development of both diseases. Benralizumab is an antieosinophilic monoclonal antibody that binds to the α subunit of the human interleukin 5 receptor that is expressed on the surface of the eosinophil and basophil. We present the first case of rapid improvement in symptoms and lung function during admission for exacerbation of a severe eosinophilic asthma associated with EGPA., Case Presentation: A 57-year-old man diagnosed with severe eosinophilic asthma associated to EGPA was admitted to the Pulmonology Department due to severe bronchospasm. At admission he presented 2300 eosinophils/µl. Despite intensive bronchodilator treatment, intravenous methylprednisolone at a dose of 80 mg/d, oxygen therapy, and budesonide nebulization, the patient continued to present daily episodes of bronchospasm. Ten days after admission, with blood eosinophil levels of 1700 cells/µl, benralizumab 30 mg sc was administered. That day, the Forced Expiratory Volume in the first second (FEV1) was 28% of the theoretical value (1150 ml). AT three days, FEV1 increased to 110 ml (31%). On the 9th day FEV1 was 51% (2100 ml). The blood eosinophil level on the 9th day was 0 cells/µl., Conclusions: The rapid improvement of FEV1 is in line with studies based on clinical trials that found improvement after two days in peak flow and one phase II study that showed rapid response in exacerbation of asthma in the emergency room. The antieosinophilic effect at 24 h and the effect in different tissues determine the rapid improvement and the potential advantage of benralizumab in the treatment of EGPA. This case suggests the usefulness of benralizumab in patients with EGPA and eosinophilic severe asthma who show bronchospasm refractory to conventional treatment during a hospitalization due to asthma exacerbation.

The synthesis and structural modulation of five pro-ligand salts was achieved using alternative sustainable synthetic strategies, the use of microwaves being the method of choice, with an 81% yield and an E factor of 43 for 3d . After complexation with Fe 3 (CO) 12 by direct reaction with the appropriate pro-ligands at 130 °C, a set of iron(II) N-heterocyclic carbene (NHC) complexes were isolated and fully characterized (via 1 H and 13 C NMR and IR spectroscopy and elemental analysis). The antibacterial activities of the iron(II)-NHC complexes were tested against standard World Health Organization priority bacterial strains: Staphylococcus aureus ATCC 29213 and Escherichia coli ATCC 25922. The results showed a significant effect of the Fe(II)-NHC side-chain on the antibacterial activity against both Gram-negative and Gram-positive bacteria. Among all compounds, the most lipophilic iron complex, 3b , was found to be the most active one, with a minimum inhibitory concentration of 8 µg/mL. Pioneering mechanistic studies suggested an alternative mechanism of action (OH· formation), which opens the way for the development of a new class of antibiotics.

We report here the first purely organometallic fac-[Mn I (CO) 3 (bis- Me NHC)Br] complex with unprecedented activity for the selective electrocatalytic reduction of CO 2 to CO, exceeding 100 turnovers with excellent faradaic yields (η CO ≈95 %) in anhydrous CH 3 CN. Under the same conditions, a maximum turnover frequency (TOF max ) of 2100 s -1 was measured by cyclic voltammetry, which clearly exceeds the values reported for other manganese-based catalysts. Moreover, the addition of water leads to the highest TOF max value (ca. 320 000 s -1 ) ever reported for a manganese-based catalyst. A Mn I tetracarbonyl intermediate was detected under catalytic conditions for the first time., (© 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.)

Chelating bis-N-heterocyclic carbene (bis-NHC) complexes of iron(ii) containing pyridyl ligands have been prepared by the reaction of [FeCl2L] [L = bipy (1), phen (2)] with [LiN(SiMe3)2] and a bis(imidazolium) salt. The [Fe(bis-NHC)L(I)2] complexes were active pre-catalysts in the oxidation of 1-phenylethanol with tert-butyl hydroperoxide in neat conditions, affording a quantitative yield of acetophenone in 4.5 h. The catalyst could be reused up to six cycles giving a turnover number (TON) of 1500. Various secondary alcohols, both aromatic and aliphatic were selectivity oxidised to the corresponding ketones in excellent yields. Compound 1 is stable in acetonitrile solution for ca. 4 h, although after 16 h, it evolves to a mixture of [Fe(bis-NHC)(bipy)2]I2 (3), [Fe(bipy)3](2+) and bis-imidazolium salt. The molecular structure of 3 has been determined by X-ray diffraction studies.

We aimed to identify the early stress response and plant performance of Medicago truncatula growing in axenic medium with ammonium or urea as the sole source of nitrogen, with respect to nitrate-based nutrition. Biomass measurements, auxin content analyses, root system architecture (RSA) response analyses, and physiological parameters were determined. Both ammonium and ureic nutrition severely affected the RSA, resulting in changes in the main elongation rate, lateral root development, and insert position from the root base. The auxin content decreased in both urea- and ammonium-treated roots; however, only the ammonium-treated plants were affected at the shoot level. The analysis of chlorophyll a fluorescence transients showed that ammonium affected photosystem II, but urea did not impair photosynthetic activity. Superoxide dismutase isoenzymes in the plastids were moderately affected by urea and ammonium in the roots. Overall, our results showed that low N doses from different sources had no remarkable effects on M. truncatula, with the exception of the differential phenotypic root response. High doses of both ammonium and urea caused great changes in plant length, auxin contents and physiological measurements. Interesting correlations were found between the shoot auxin pool and both plant length and the "performance index" parameter, which is obtained from measurements of the kinetics of chlorophyll a fluorescence. Taken together, these data demonstrate that both the indole-3-acetic acid pool and performance index are important components of the response of M. truncatula under ammonium or urea as the sole N source.

The coordination versatility of a 1,3,5-triphenylbenzene-tris-mesoionic carbene ligand is illustrated by the preparation of complexes with three different metals: rhodium, iridium and nickel. The rhodium and iridium complexes contained the [MCl(COD)] fragments, while the nickel compound contained [NiCpCl]. The preparation of the tris-MIC (MIC = mesoionic carbene) complex with three [IrCl(CO)2] fragments, allowed the estimation of the Tolman electronic parameter (TEP) for the ligand, which was compared with the TEP value for a related 1,3,5-triphenylbenzene-tris-NHC ligand. The electronic properties of the tris-MIC ligand were studied by cyclic voltammetry measurements. In all cases, the tris-MIC ligand showed a stronger electron-donating character than the corresponding NHC-based ligands. The catalytic activity of the tri-rhodium complex was tested in the addition reaction of arylboronic acids to α,β-unsaturated ketones.

Phosphate starvation compromises electron flow through the cytochrome pathway of the mitochondrial electron transport chain, and plants commonly respond to phosphate deprivation by increasing flow through the alternative oxidase (AOX). To test whether this response is linked to the increase in nitric oxide (NO) production that also increases under phosphate starvation, Arabidopsis thaliana seedlings were grown for 15 d on media containing either 0 or 1mM inorganic phosphate. The effects of the phosphate supply on growth, the production of NO, respiration, the AOX level and the production of superoxide were compared for wild-type (WT) seedlings and the nitrate reductase double mutant nia. Phosphate deprivation increased NO production in WT roots, and the AOX level and the capacity of the alternative pathway to consume electrons in WT seedlings; whereas the same treatment failed to stimulate NO production and AOX expression in the nia mutant, and the plants had an altered growth phenotype. The NO donor S-nitrosoglutathione rescued the growth phenotype of the nia mutants under phosphate deprivation to some extent, and it also increased the respiratory capacity of AOX. It is concluded that NO is required for the induction of the AOX pathway when seedlings are grown under phosphate-limiting conditions., (© The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.)