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This study validates a computational protocol to predict the stability of heterodinuclear complexes by varying ligands on both moieties and analyzing the reaction Gibbs free energy (Δ G r ) values. To this purpose, a series of Eu-Al complexes with the general formula [Eu( L Eu ) 3 Al( L Al ) 3 ], where L Eu is the ligand of europium and L Al is an oxygen donor ligand of aluminum, is used. The nature of the bridging bonds and thermochemical characteristics (Δ G r , enthalpy, and entropy) of the complexes were evaluated via DFT calculations. We demonstrated that both entropic and enthalpic effects play a relevant role in the stability. The analysis of the series allows us to identify three Δ G r ranges where heterodinuclear complexes are (i) stable and easy to characterize, (ii) fragile and difficult to characterize, and (iii) not observed (unreacted precursors are recovered). To rationalize the trend of the stability and correlate it with the chemical nature of the ligands, we investigated the condensed Fukui function on the Al fragment. Results suggest that to obtain stable heteronuclear complexes, it is necessary to consider ligands with small condensed Fukui function values. This corresponds to a less nucleophilic oxygen site, yet counterintuitively, it allows the ligand to delocalize the received electronic charge and stabilize the complex.

Sandwich d/f heterometallic complexes [(Ln(hfac) 3 ) 2 M(acac) 3 ] (Ln = La, Pr, Sm, Dy and M = Co; Ln = La and M = Ru) were prepared in strictly anhydrous conditions reacting the formally unsaturated fragment [Ln(hfac) 3 ] and [M(acac) 3 ] in a 2-to-1 molar ratio. These heterometallic complexes are highly sensitive to moisture. Spectroscopic observation revealed that on hydrolysis, these compounds yield dinuclear heterometallic compounds [Ln(hfac) 3 M(acac) 3 ], prepared here for comparison purposes only. Quantum mechanical calculations supported, on the one hand, the hypothesis on the geometrical arrangement obtained from ATR-IR and NMR spectra and, on the other hand, helped to rationalize the spontaneous hydrolysis reaction.

Rare-earth tris-diketonato [RE(dike) 3 pyterpy] metalloligands can be prepared reacting at room temperature [RE(dike) 3 dme] (dme = 1,2-dimethoxyethane; dike = tta with Htta = 2-thenoyltrifluoroacetone and RE = La, 1 ; Y, 2 ; Eu, 3 ; Dy, 4 ; or dike = hfac with Hhfac hexafluoroacetylacetone, and RE = Eu, 5 ; Tb, 6 ; Yb 7 ) with 4'-(4‴-pyridil)-2,2':6',2″-terpyridine (pyterpy). The molecular structures of 1 , 5 , 6 , and 7 have been studied through single-crystal X-ray diffraction showing mononuclear neutral complexes with the rare-earth ion in coordination number nine and with a muffin-like coordination geometry. [RE(tta) 3 pyterpy] promptly reacts with [M(tta) 2 dme] with formation of [Mpyterpy 2 ][RE(tta) 4 ] 2 (M = Zn, RE = Y, 8 ; M = Co, RE = Dy, 9 ). Consistently, [Zn(hfac) 2 dme] reacts at room temperature with 2 equiv of pyterpy yielding [Znpyterpy 2 ][hfac] 2 10 that easily can be transformed by reaction with 2 equiv of [Eu(hfac) 3 ] in [Znpyterpy 2 ][Eu(hfac) 4 ] 2 11 that has been structurally characterized. Finally, 1 , 2 , 3 , 5 , and 7 metalloligands react at room temperature in few minutes with [PtCl(μ-Cl)PPh 3 ] 2 yielding the heterometallic molecular complexes [RE(dike) 3 pyterpyPtCl 2 PPh 3 ] (dike = tta, RE = La, 12 ; Y, 13 ; Eu; 14 ; dike = hfac, RE = Eu, 15 ; Yb, 16 ).

A reaction in anhydrous toluene between the formally unsaturated fragment [Ln(hfac) 3 ] (Ln 3+ = Eu 3+ , Gd 3+ and Er 3+ ; Hhfac = hexafluoroacetylacetone) and [Al(qNO) 3 ] (HqNO = 8-hydroxyquinoline N -oxide), here prepared for the first time from [Al(O t Bu) 3 ] and HqNO, affords the dinuclear heterometallic compounds [Ln(hfac) 3 Al(qNO) 3 ] (Ln 3+ = Eu 3+ , Gd 3+ and Er 3+ ) in high yields. The molecular structures of these new compounds revealed a dinuclear species with three phenolic oxygen atoms bridging the two metal atoms. While the europium and gadolinium complexes show the coordination number (CN) 9 for the lanthanide centre, in the complex featuring the smaller erbium ion, only two oxygens bridge the two metal atoms for a resulting CN of 8. The reaction of [Eu(hfac) 3 ] with [Alq 3 ] (Hq = 8-hydroxyquinoline) in the same conditions yields a heterometallic product of composition [Eu(hfac) 3 Alq 3 ]. A recrystallization attempt from hot heptane in air produced single crystals of two different morphologies and compositions: [Eu 2 (hfac) 6 Al 2 q 4 (OH) 2 ] and [Eu 2 (hfac) 6 (µ-Hq) 2 ]. The latter compound can be directly prepared from [Eu(hfac) 3 ] and Hq at room temperature. Quantum mechanical calculations confirm (i) the higher stability of [Eu(hfac) 3 Al(qNO) 3 ] vs. the corresponding [Eu(hfac) 3 Alq 3 ] and (ii) the preference of the Er complexes for the CN 8, justifying the different behaviour in terms of the Lewis acidity of the metal centre.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), believed to have originated from a bat species, can infect a wide range of non-human hosts. Bats are known to harbor hundreds of coronaviruses capable of spillover into human populations. Recent studies have shown a significant variation in the susceptibility among bat species to SARS-CoV-2 infection. We show that little brown bats (LBB) express angiotensin-converting enzyme 2 receptor and the transmembrane serine protease 2, which are accessible to and support SARS-CoV-2 binding. All-atom molecular dynamics (MD) simulations revealed that LBB ACE2 formed strong electrostatic interactions with the RBD similar to human and cat ACE2 proteins. In summary, LBBs, a widely distributed North American bat species, could be at risk of SARS-CoV-2 infection and potentially serve as a natural reservoir. Finally, our framework, combining in vitro and in silico methods, is a useful tool to assess the SARS-CoV-2 susceptibility of bats and other animal species.

The interest for heterometallic lanthanide- d or- p metal (Ln-M) complexes is growing because of a potential cooperative or synergistic effect related to the proximity of two different metals in the same molecular architecture affording special tunable physical properties. To exploit the potentiality of Ln-M complexes, suitable synthetic approaches, and the in-depth understanding of the effect of each building block on their properties are mandatory. Here, we report the study on a family of heterometallic luminescent complexes [Ln(hfac) 3 Al(L) 3 ], Ln= Eu 3+ and Tb 3+ . Using different L ligands, we investigated the effect of the steric and electronic properties of the Al(L) 3 fragment, highlighting the general validity of the employed synthetic route. A marked difference in the light emission of [Eu(hfac) 3 Al(L) 3 ] and [Tb(hfac) 3 Al(L) 3 ] complexes has been observed. Thanks to photoluminescence experiments and Density Functional Theory calculations, Ln 3+ emissions are explained with a model involving two non-interacting excitation paths through hfac or Al(L) 3 ligands., Competing Interests: The authors declare no competing interests., (© 2023 The Author(s).)

The similar reactivity of lanthanides generally leads to statistically populated polynuclear complexes, making the rational design of ordered hetero-lanthanide compounds extremely challenging. Here we report on the site selectivity in hetero-lanthanide tetranuclear complexes afforded by the relatively simple ditopic pyterpyNO ligand (4'-(4-pyridil)-2,2':6',2"-terpyridine N-oxide). The sequential room temperature reaction of RE 2 (tta) 6 (pyterpyNO) 2 (where RE=Y, (1); Eu, (2), Dy, (3) Htta=2-thenoyltrifluoroacetone) with La(tta) 3 dme (dme=dimethoxyethane) yielded Y 2 La 2 (tta) 12 (pyterpyNO) 2 (4), Dy 2 La 2 (tta) 12 (pyterpyNO) 2 (5) and Eu 2 La 2 (tta) 12 (pyterpyNO) 2 (6). Single crystals X-ray diffraction studies showed that 4, 5 and 6 are isostructural, featuring a tetranuclear structure with two different metal coordination sites with coordination numbers 8 (CN8) and 9 (CN9). The two smaller cations are mainly bridged by the O-donor atoms of the NO groups of two pyterpyNO ligands (CN8), while the larger lanthanum centres are bound by a terpyridine unit (CN9). Size selectivity has been studied with structural and magnetic studies in the solid state and through 19 F NMR and photoluminescence studies in solution, showing a direct dependence on the difference of ionic radii of the ions and yielding a 91 % selectivity for 4. Furthermore, 19 F NMR, X-ray and PL studies pointed out that the nature of the product is independent from the synthetic route for compound Eu 2 Y 2 (tta) 12 (pyterpyNO) 2 (7), keeping the ion selectivity also for a self-assembly reaction. Unexpectedly, these studies have evidenced that selectivity is not exclusively governed by electrostatic interactions related to size dimensions., (© 2022 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.)

There is mounting evidence of SARS-CoV-2 spillover from humans into many domestic, companion, and wild animal species. Research indicates that humans have infected white-tailed deer, and that deer-to-deer transmission has occurred, indicating that deer could be a wildlife reservoir and a source of novel SARS-CoV-2 variants. We examined the hypothesis that the Omicron variant is actively and asymptomatically infecting the free-ranging deer of New York City. Between December 2021 and February 2022, 155 deer on Staten Island, New York, were anesthetized and examined for gross abnormalities and illnesses. Paired nasopharyngeal swabs and blood samples were collected and analyzed for the presence of SARS-CoV-2 RNA and antibodies. Of 135 serum samples, 19 (14.1%) indicated SARS-CoV-2 exposure, and 11 reacted most strongly to the wild-type B.1 lineage. Of the 71 swabs, 8 were positive for SARS-CoV-2 RNA (4 Omicron and 4 Delta). Two of the animals had active infections and robust neutralizing antibodies, revealing evidence of reinfection or early seroconversion in deer. Variants of concern continue to circulate among and may reinfect US deer populations, and establish enzootic transmission cycles in the wild: this warrants a coordinated One Health response, to proactively surveil, identify, and curtail variants of concern before they can spill back into humans.

Multiple domestic and wild animal species are susceptible to SARS-CoV-2 infection. Cattle and swine are susceptible to experimental SARS-CoV-2 infection. The unchecked transmission of SARS-CoV-2 in animal hosts could lead to virus adaptation and the emergence of novel variants. In addition, the spillover and subsequent adaptation of SARS-CoV-2 in livestock could significantly impact food security as well as animal and public health. Therefore, it is essential to monitor livestock species for SARS-CoV-2 spillover. We developed and optimized species-specific indirect ELISAs (iELISAs) to detect anti-SARS-CoV-2 antibodies in cattle, swine, and chickens using the spike protein receptor-binding domain (RBD) antigen. Serum samples collected prior to the COVID-19 pandemic were used to determine the cut-off threshold. RBD hyperimmunized sera from cattle ( n = 3), swine ( n = 6), and chicken ( n = 3) were used as the positive controls. The iELISAs were evaluated compared to a live virus neutralization test using cattle ( n = 150), swine ( n = 150), and chicken ( n = 150) serum samples collected during the COVID-19 pandemic. The iELISAs for cattle, swine, and chicken were found to have 100% sensitivity and specificity. These tools facilitate the surveillance that is necessary to quickly identify spillovers into the three most important agricultural species worldwide.

The cellular entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) involves the association of its receptor binding domain (RBD) with human angiotensin converting enzyme 2 (hACE2) as the first crucial step. Efficient and reliable prediction of RBD-hACE2 binding affinity changes upon amino acid substitutions can be valuable for public health surveillance and monitoring potential spillover and adaptation into non-human species. Here, we introduce a convolutional neural network (CNN) model trained on protein sequence and structural features to predict experimental RBD-hACE2 binding affinities of 8,440 variants upon single and multiple amino acid substitutions in the RBD or ACE2. The model achieves a classification accuracy of 83.28% and a Pearson correlation coefficient of 0.85 between predicted and experimentally calculated binding affinities in five-fold cross-validation tests and predicts improved binding affinity for most circulating variants. We pro-actively used the CNN model to exhaustively screen for novel RBD variants with combinations of up to four single amino acid substitutions and suggested candidates with the highest improvements in RBD-ACE2 binding affinity for human and animal ACE2 receptors. We found that the binding affinity of RBD variants against animal ACE2s follows similar trends as those against human ACE2. White-tailed deer ACE2 binds to RBD almost as tightly as human ACE2 while cattle, pig, and chicken ACE2s bind weakly. The model allows testing whether adaptation of the virus for increased binding with other animals would cause concomitant increases in binding with hACE2 or decreased fitness due to adaptation to other hosts., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Competing financial interests The authors declare no competing financial interests.

The high incidence of the resistance phenomenon represents one of the most important limitations to the clinical usefulness of cisplatin as an anticancer drug. Notwithstanding the considerable efforts to solve this problem, the circumvention of cisplatin resistance remains a challenge in the treatment of cancer. In this work, the synthesis and characterization of two trans -dichloro(triphenylarsino)( N , N -dialkylamino)platinum(II) complexes ( 1 and 2 ) were described. The trypan blue exclusion assay demonstrated an interesting antiproliferative effect for complex 1 in ovarian carcinoma-resistant cells, A2780cis. Quantitative analysis performed by ICP-AES demonstrated a scarce ability to platinate DNA, and a significant intracellular accumulation. The investigation of the mechanism of action highlighted the ability of 1 to inhibit the relaxation of supercoiled plasmid DNA mediated by topoisomerase II and to stabilize the cleavable complex. Cytofluorimetric analyses indicated the activation of the apoptotic pathway and the mitochondrial membrane depolarization. Therefore, topoisomerase II and mitochondria could represent possible intracellular targets. The biological properties of 1 and 2 were compared to those of the related trans -dichloro(triphenylphosphino)( N , N -dialkylamino)platinum(II) complexes in order to draw structure-activity relationships useful to face the resistance phenotype.

Mononuclear rare-earth tris-β-diketonato complexes RE(tta) 3 dme [RE = Y ( 1 ), La ( 2 ), Dy ( 3 ), or Eu ( 4 ); Htta = 2-thenoylacetone; dme = 1,2-dimethoxyethane] react cleanly at room temperature in a 1:1 molar ratio with the heteroditopic divergent ligand 4'-(4-pyridyl)-2,2':6',2″-terpyridine N -oxide (pyterpyNO) to yield RE 2 (tta) 6 (pyterpyNO) n , where n = 2 for RE = Y ( 5 ), Dy ( 6 ), or Eu ( 7 ) and n = 3 for RE = La ( 8 ). The crystal structure of 5 revealed a dinuclear compound with two pyterpyNO's bridging through the oxygen atom in a hypodentate mode leaving the terpyridine moieties uncoordinated. Using a metal:pyterpyNO molar ratio of 2 for RE = Y ( 9 ), Dy ( 10 ), or Eu ( 11 ), it was possible to isolate the molecular complexes RE 4 (tta) 12 (pyterpyNO) 2 , while using a 5:3 molar ratio, the product La 5 (tta) 12 (pyterpyNO) 3 ( 12 ) can be obtained. 89 Y nuclear magnetic resonance spectroscopy revealed two different yttrium centers at room temperature for 9 . An X-ray diffraction study of 10 showed a symmetrical tetranuclear structure resulting from the coordination of two Dy(tta) 3 fragments to the two hypodentate terpyridines of the dinuclear unit and presenting two different coordination sites for metals with coordination numbers of 8 and 9. Magnetic studies of 6 and 10 revealed the presence of an antiferromagnetic interaction between the two Dy(III) atoms bound by the NO bridges. These compounds displayed a slow relaxing magnetization through Orbach ( 6 ) and Raman ( 10 ) processes in the absence of an applied magnetic field; the rate increased upon application of a 1 kOe field. 7 and 11 showed a bright red emission typical of Eu 3+ . The two complexes have similar emission properties mainly determined by the employed β-diketonato ligands.

Two homometallic Coordination Polymers (CPs) with composition [Ln(hfac) 3 bipy] n (Ln 3+ = Eu 3+ , 1 , and Tb 3+ , 2 ; hfac = hexafluoroacetylacetonato, bipy = 4,4'-bipyridine) were used to develop a family of ratiometric luminescent thermometers containing Eu 3+ and Tb 3+ as red and green emitters, respectively. The thermometric properties of pure CPs and of their mixtures having an Eu 3+ /Tb 3+ molar ratio of 1:1, 1:3, 1:5, and 1:10 (samples: Eu1Tb1 , Eu1Tb3 , Eu1Tb5 , and Eu1Tb10 ) were studied in the 83-383 K temperature range. Irrespective of the chemical composition, we observed similar thermometric responses characterized by broad applicative temperature ranges (from 100 to 165 K wide), and high relative thermal sensitivity values (S r ), up to 2.40% K -1 , in the physiological temperature range (298-318 K). All samples showed emissions endowed with peculiar and continuous color variation from green (83 K) to red (383 K) that can be exploited to develop a colorimetric temperature indicator. At fixed temperature, the color of the emitted light can be tuned by varying composition and excitation wavelength.

Resistance to platinum-based anticancer drugs represents an important limit for their clinical effectiveness and one of the most important field of investigation in the context of platinum compounds. From our previous studies, Pt II complexes containing the triphenylphosphino moiety have been emerging as promising agents, showing significant cytotoxicity to resistant ovarian carcinoma cells. Two brominated triphenylphosphino trans-platinum derivatives were prepared and evaluated on human tumor cell lines, sensitive and resistant to cisplatin. The new complexes exert a notable antiproliferative effect on resistant ovarian carcinoma cells, showing a remarkable intracellular accumulation and the ability to interact with different intracellular targets. The interaction with DNA, the collapse of mitochondrial transmembrane potential, and the impairment of intracellular redox state were demonstrated. Moreover, a selectivity towards the selenocysteine of thioredoxin reductase was observed. The mechanism of action is discussed with regard to the resistance phenomenon in ovarian carcinoma cells., (© 2021 The Authors. ChemMedChem published by Wiley-VCH GmbH.)

A series of iminopyridine complexes of platinum(II), bearing a flexible diethereal, aryl terminated residue, where the size of aryl group is varied from phenyl to 9-anthracenyl, was synthesized. The new complexes are soluble and stable in DMSO/H 2 O mixtures. Besides the metal center, aryl groups are available for further interactions with DNA, due to the good side chain flexibility. The new aryl functionalized iminopyridine dichlorido platinum(II) complexes show a significant antiproliferative activity on ovarian carcinoma cells and notably, complex 13 is able to overcome cisplatin resistance. The study of the interaction mode of 13 with DNA highlighted the ability to form a molecular complex characterized by a dual (intercalative and groove binding) geometry. The complex is also able to covalently add to DNA even though interstrand cross-links appear significantly hampered with respect to cisplatin. The interactions with the macromolecule are discussed in view of the observed cell effect., (Copyright © 2020 Elsevier Inc. All rights reserved.)

A family of homodinuclear Ln 3+ (Ln 3+ = Gd 3+ , Eu 3+ ) luminescent complexes with the general formula [Ln 2 (β-diketonato) 6 ( N -oxide) y ] has been developed to study the effect of the β-diketonato and N -oxide ligands on their thermometric properties. The investigated complexes are [Ln 2 (tta) 6 (pyrzMO) 2 ] (Ln = Eu ( 1 ·C 7 H 8 ), Gd ( 5 )), [Ln 2 (dbm) 6 (pyrzMO) 2 ] (Ln = Eu ( 2 ), Gd ( 6 )), [Ln 2 (bta) 6 (pyrzMO) 2 ] (Ln = Eu ( 3 ), Gd ( 7 )), [Ln 2 (hfac) 6 (pyrzMO) 3 ] (Ln = Eu ( 4 ), Gd ( 8 )) (pyrzMO = pyrazine N -oxide, Htta = thenoyltrifluoroacetone, Hdbm = dibenzoylmethane, Hbta = benzoyltrifluoroacetone, Hhfac = hexafluoroacetylacetone, C 7 H 8 = toluene), and their 4,4'-bipyridine N -oxide (bipyMO) analogues. Europium complexes emit a bright red light under UV radiation at room temperature, whose intensity displays a strong temperature ( T ) dependence between 223 and 373 K. This remarkable variation is exploited to develop a series of luminescent thermometers by using the integrated intensity of the 5 D 0 → 7 F 2 europium transition as the thermometric parameter (Δ). The effect of different β-diketonato and N -oxide ligands is investigated with particular regard to the shape of thermometer calibration (Δ vs T ) and relative thermal sensitivity curves: i.e.. the change in Δ per degree of temperature variation usually indicated as S r (% K -1 ). The thermometric properties are determined by the presence of two nonradiative deactivation channels, back energy transfer (BEnT) from Eu 3+ to the ligand triplet levels and ligand to metal charge transfer (LMCT). In the complexes bearing tta and dbm ligands, whose triplet energy is ca. 20000 cm -1 , both deactivation channels are active in the same temperature range, and both contribute to determine the thermometric properties. Conversely, with bta and hfac ligands the response of the europium luminescence to temperature variation is ruled by LMCT channels since the high triplet energy (>21400 cm -1 ) makes BEnT ineffective in the investigated temperature range.

Platinum(II) complexes of the type [Pt(Cl)(PPh 3 ){(κ 2 -N,O)-(1{C(R)=N(OH)-2(O)C 6 H 4 })}] with R=Me, H, (1 and 2) were synthesized and characterized. Single-crystal X-ray diffraction confirmed the proposed (SP4-3) configuration for 1. Study of the antiproliferative activity, performed on a panel of human tumor cell lines and on mesothelial cells, highlighted complex 2 as the more effective. In particular, it showed a remarkable cytotoxicity in ovarian carcinoma cells (A2780) and interestingly, a significant antiproliferative effect on cisplatin resistant cells (A2780cis). Investigation into the intracellular mechanism of action demonstrated that 2 had a lower ability to platinate DNA than did cisplatin, which was taken as reference, and a notably higher uptake in resistant cells. A significant accumulation in mitochondria, along with the ability to induce concentration-dependent mitochondrial membrane depolarization and intracellular reactive oxygen species production, allowed us to propose a mitochondrion-mediated pathway as responsible for the interesting cytotoxic profile of complex 2., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Single-crystal-to-single-crystal post-synthetic modifications (PSMs) of Lanthanide Organic Frameworks (LOFs) {[Ln 2 (H 2 L) 3 (DMF) 4 ]·2DMF} n (Ln = Gd, 1 and Eu, 2; H 4 L = 2,5-dihydroxyterephthalic acid; DMF = dimethylformamide), carried out by treatment with (a) chloroform or (b) an imidazole solution in chloroform, yielded respectively isostructural {[Ln 2 (H 2 L) 3 (DMF) 4 ]·CHCl 3 } n (Ln = Gd, 3; Eu, 4) or {[Ln 2 (H 2 L) 3 (Im) 4 ][Ln 2 (H 2 L) 3 (Im) 2 (H 2 O) 2 ]·6Im·2CHCl 3 } n (Ln = Gd, 5; Eu, 6). Single crystal X-ray diffraction studies of 5 showed two different regularly alternating dimeric units in the LOF and two regularly alternating cavities with different guest molecules. All compounds revert to the parent LOF, 1 or 2, when treated with DMF at 90 °C for 8 h. Europium-LOFs (2, 4 and 6) showed a faint red emission that progressively gained intensity upon cooling from RT to liquid nitrogen temperature. This behaviour was exploited to develop a family of luminescent thermometers whose characteristics were affected by the structural and coordinative modifications induced by PSMs.

New pyridinimino complexes of platinum(II) [PtCl 2 (N^N-R)] (N^N = 2-pyridylmethanimino, R = -(CH 2 ) 2 O(CH 2 ) 2 OH, -(CH) 2 O(CH 2 ) 2 OCH 2 Pyr), Pyr = pyren-1-yl) have been prepared. They are characterized by a dioxygenated alkyl side chain and, in one case, by a fluorescent terminal 1-pyrenyl residue. The complexes were characterized by elemental analysis, IR, 1 H-, 13 C-and 195 Pt NMR spectroscopies. For [PtCl 2 (N^N-(CH 2 ) 2 O(CH 2 ) 2 OH] the molecular structure was determined by single crystal X-ray diffraction. The complexes are soluble and stable in DMSO/H 2 O (80/20, v/v). The pyrenyl terminated compound was tested as antiproliferative agent against selected human cancer cell lines. Comparable cytotoxic effect was obtained on human ovarian carcinoma A-2780 and A-2780cis cells, thus suggesting a certain ability to circumvent cisplatin resistance. The interaction of this complex with DNA was investigated by linear flow dichroism and by spectrophotometric (absorbance and fluorescence) titrations. Both techniques enlightened the presence of a complex mode of interaction with DNA, involving both groove binding and intercalation., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Heterotopic divergent ligand N-oxide-4,4'-bipyridine (bipyMO) has been herein exploited for the preparation of hetero-bimetallic coordination polymers where Ln(hfac)3 and M(hfac)2 nodes regularly alternate (Hhfac = 1,1,1,5,5,5-hexafluoro-2,4-pentanedione), bipyMO being able to selectively use its two potential coordination sites to discriminate the metal ions. The synthesis of three coordination polymers, [Ln(hfac)3M(hfac)2(bipyMO)2]n (Ln = Eu, M = Zn, 1; Ln = Eu, M = Cu, 2, Ln = Dy, M = Co, 3), was carried out by reacting the appropriate [M(hfac)2(bipyMO)]n and [Ln(hfac)3] precursors in toluene in the presence of a given stoichiometric amount of bipyMO. The products were characterized by elemental analysis, X-ray powder diffraction, and FTIR spectroscopy. Single crystal X-ray diffraction studies carried out on 2 showed that it was formed by chains containing the hexa-coordinated 3d metal (Cu(hfac)2[N]2) and the octa-coordinated lanthanide (Eu(hfac)3[O]2) nodes, where [N] and [O] stand for the donor atom of the bridging divergent ligand. The X-ray powder diffraction patterns of the three compounds and the comparison of their cell constant values allowed establishing that the derivatives were isotypic. Photoluminescence (PL) studies on microcrystalline sample powders evidenced a bright red emission for 1 with an absolute PL quantum yield of 0.24. The sensitized emission of Eu3+ can be excited in a wide wavelength range, from UV to visible, up to ≈450 nm. Conversely, europium emissions are not detectable in 2 due to the presence of Cu(hfac)2(bipyMO) moieties whose strong absorption overlaps Eu3+ transitions. Magnetic measurements conducted on 3 revealed the presence of a weak ferromagnetic interaction below 2.1 K. An ac susceptibility study highlighted a slow relaxation of the magnetization of 3 with an applied static magnetic field of 0.1 T, which could be equally fitted with a Orbach-direct or a Raman-direct mechanism. No relaxation dynamics was detected without the application of a static magnetic field.

We describe a new organic/inorganic material emitting circularly polarized luminescence (CPL). The hybrid system was obtained by the following steps: (i) preliminary grafting of the europium N,N-dibutylcarbamate [Eu(O 2 CNBu 2 ) 3 ] complex onto silica, (ii) substitution of the residual carbamato groups with anionic 1,3-diphenyl-1,3-propanedionato ligands (dbm), and (iii) subsequent introduction of the neutral tridentate chiral ligand 2,6-bis(isopropyl-2-oxazolin-2-yl)pyridine ( i Pr-PyBox) in the metal coordination sphere. The solid material is stable to air and does not leach either the metal or the ligand. Samples of both enantiomers have been studied, showing mirror-image CPL spectra. The molecular compounds [Eu(dbm) 3 -(S)-( i Pr-PyBox)] and [Eu(dbm) 3 -(R)-( i Pr-PyBox)] were prepared for comparison purposes and their molecular structures studied by single-crystal X-ray diffraction, showing mononuclear derivatives with a coordination number of 9 for europium. Powder X-ray diffraction showed a single crystalline phase. Photoluminescence and CPL evidenced the presence of a single emitting species.

Some new platinum(II) complexes have been prepared, of general formula trans-[PtCl2(PPh3){NH(Bu)CH2Ar}], where the dimension of the Ar residue in the secondary amines has been varied from small phenyl to large pyrenyl group. The obtained complexes, tested in vitro towards a panel of human tumor cell lines showed an interesting antiproliferative effect on both cisplatin-sensitive and -resistant cells. For the most cytotoxic derivative 2a the investigation on the mechanism of action highlighted the ability to induce apoptosis on resistant cells and interestingly, to inhibit the catalytic activity of topoisomerase II., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

In April 2024, ten cats died in a rural South Dakota (SD) residence, showing respiratory and neurological symptoms. Necropsy and laboratory testing of two cats confirmed H5N1 clade 2.3.4.4b infection. The viral genome sequences are closely related to recent SD cattle H5N1 sequences. Cat H5N1 genomes had unique mutations, including T143A in haemagglutinin, known to affect infectivity and immune evasion, and two novel mutations in PA protein (F314L, L342Q) that may affect polymerase activity and virulence, suggesting potential virus adaptation. Dead cats showed systemic infection with lesions and viral antigens in multiple organs. Higher viral RNA and antigen in the brain indicated pronounced neurotropism. Lectin-histochemistry revealed widespread co-expression of sialic acid α-2,6 and α-2,3 receptors, suggesting cats could serve as mixing vessels for reassortment of avian and mammalian influenza viruses. No differences in clade 2.2 or 2.3.4.4b H5 pseudoviruses binding to cat lung/brain tissues indicated the neurotropism is unlikely mediated by receptor binding affinity.

The grafting and the postgrafting functionalization of lanthanide ions on commercial amorphous silica have been herein carried out by using as a precursor the terbium N,N-dibutylcarbamato derivative [Tb(O2CNBu2)3]. The reaction of the complex with the surface silanols involved only a fraction of the carbamato ligands. The following protolytic substitution of the residual carbamato ligands was carried out by exploiting the Brønsted's acidity of the β-diketone dibenzoylmethane (Hdbm), in view of the antenna effect of the β-diketonato groups, which are commonly used in lanthanide photoluminescence studies. The reaction proceeded at room temperature in a clean and easy way affording the introduction of the chosen functionality in the lanthanide coordination sphere. The same procedure has been followed by using as a precursor the X-ray characterized heterometallic N,N-dibutylcarbamato complex [NH2Bu2]2[Ln4(CO3)(O2CNBu2)12] (Ln = Eu, Tb, Tm). In both cases, X-ray photoelectron spectroscopy evidenced the chemical implantation of the lanthanide ions on the silica surface, and photoluminescence studies pointed out the potentiality of the proposed synthetic approach in the preparation of highly luminescent materials.

Lanthanides are easily extracted as N,N-dibutylcarbamato complexes from aqueous solutions of their chlorides into heptane solutions of dibutylamine saturated with CO2. The products are recovered in high yields and are soluble in hydrocarbons. The derivatives [Ln(O2CNBu2)3]n [Ln = Nd (1), Eu (2), Tb (3)], [NH2Bu2]2[Ln4(CO3)(O2CNBu2)12] [Ln = Tb (4), Sm (5), Eu (6)], and [Sm4(CO3)(O2CNBu2)10], 7, have thus been obtained. The crystal and molecular structure of 4 has been solved; the samarium and europium complexes 5 and 6 were found to be isostructural. Mass spectra of the complexes 1-3, 4, and 7 (in MeCN/toluene) reveal that equilibria are present in solution. Compound 2 has been reacted in toluene with NHBz2 in the presence of CO2 affording [NH2Bz2][Eu(O2CNBz2)4], 8, through a ligand exchange process. By thermal treatment, 8 afforded [Eu(O2CNBz2)3]n, 9. With a similar procedure [Sm(O2CNBz2)3]n, 10, was obtained from 5. According to the photoluminescence study carried out on solid samples of 2, 4, 5, 7, and 8, the metal centered f-f transitions represent the only effective way to induce lanthanide luminescence in these complexes.

A convenient synthetic route and the characterization of complexes trans-[PtCl2(L)(PPh3)] (L=Et2NH (2), (PhCH2)2NH (3), (HOCH2CH2)2NH) (4) are reported. The antiproliferative activity was evaluated on three human tumor cell lines. The investigation on the mechanism of action highlighted for the most active complex 4 the capacity to affect mitochondrial functions. In particular, both the induction of the mitochondrial permeability transition phenomenon and an aspecific membrane damage occurred, depending on concentration., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

The syntheses of the complexes [PtCl(2)(NCR)L] [R = Me, Et; L = PPh(3); R = Et, L = Py, CO] and [PtCl{(κ(2)-P,C)P(OC(6)H(4))(OPh)(2)}(NCEt)] are described starting from the easily available [PtCl(2)(NCR)(2)]. The stability of the products under different experimental conditions is discussed as well as their use as precursors to dinuclear complexes [Pt(μ-Cl)ClL](2). The crystal and molecular structures of cis-[PtCl(2)(NCEt)(PPh(3))], [SP-4-2]-[PtCl{(κ(2)-P,C)P(OC(6)H(4))(OPh)(2)}(NCEt)] and trans-[Pt(μ-Cl){(κ(2)-P,C)P(OC(6)H(4))(OPh)(2)}](2) are reported.

Crystals of trans-Pt₂(μ-X)₂X₂(CO)₂ (X = Br, I) have been grown and their molecular and crystalline structures have been solved by X-ray diffraction methods. In both cases the dinuclear molecules are bent, with a bending angle of 164.6° and 156.5° for the bromide and the iodide, respectively. While the structure of the bromo-derivative is reported here for the first time, a modification of trans-Pt₂(μ-I)₂I₂(CO)₂ with planar centrosymmetric molecules is known. This appears to be a rare case of a platinum(II) halo-bridged derivative structurally characterized in both bent and planar forms.

N,N-di- iso-propylcarbamato derivatives of boron(III) have been synthesized from di-iso-propylamine and boron trichloride in the presence of carbon dioxide. With a large excess of amine, a single boron product was obtained, [NH2i)Pr2][B(O2CNiPr2)4], 1, while with a lower excess a mixture of 1 and of the dinuclear derivative [B2(O2CNiPr2)6], 2, was produced. By heating in vacuo at 60 degrees C, solid 1 slowly converted to 2. The transformation was reversible, 2 giving 1 back with di- iso-propylamine under carbon dioxide at atmospheric pressure. The molecular structure of both compounds was established by X-ray diffraction methods. Compound 1 is constituted by ion-pairs where the ammonium cation is hydrogen-bonded to the mononuclear anion. Compound 2 is a dinuclear species with two bridging carbamato ligands. In both derivatives, boron shows tetrahedral coordination. As IR- and 1H NMR spectra of the two species are well differentiated, it is possible to monitor the interconversion of 1 and 2 by both spectroscopic methods.

Reactions of perchlorates of iron(II), nickel(II), and zinc(II) with 2,2':6',2'':6'',2'"-quaterpyridine (qtpy) gave the first crystallographically established bis-qtpy metal complexes of formula [M(qtpy)(2)][ClO(4)](2) (M = Fe, Ni, Zn). Coordination of two terdentate quaterpyridines to the same center produces a distorted octahedron of six nitrogen atoms around the metal, leaving two pendant pyridyl groups, one for each quaterpyridine. For the diamagnetic zinc system, an NMR investigation has been carried out in order to establish the conditions to obtain the intermediate mono-qtpy complex, of formula [Zn(qtpy)(H(2)O)(2)][ClO(4)](2), which has also been crystallographically established. The corresponding hexafluorophosphate derivatives [M(qtpy)(2)][PF(6)](2) (M = Ni and Zn) were prepared in DMF at room temperature.

The octanuclear aggregates M(8)(mu(4)-O)(2)(O(2)CN(i)()Pr(2))(12) [M = Mn(II) 1, Co(II) 2, Ni(II) 3] have been prepared in good yields by controlled hydrolysis of the corresponding metal carbamate precursors [M(O(2)CN(i)()Pr(2))(2)](n)(). X-ray analysis has shown compounds 1-3 to be isostructural. The core of 2 contains two distorted [M(4)O] tetrahedra related by an inversion center. The hexanuclear carbamates M(6)(O(2)CNEt(2))(12) in toluene undergo a metal redistribution process with formation of the hexanuclear carbamates M'(x)M' '(6-x)(O(2)CNEt(2))(12), M' = Co, M' ' = Mn, as evidenced by mass-spectrometric data. In the presence of moisture, the mixed octanuclear carbamates Co(x)Mn(6-x)(MnO)(CoO)(O(2)CNEt(2))(12) were promptly formed and detected by DCI/MS measurements. Mass spectral data of Co(8)(mu(4)-O)(2)(O(2)CN(i)Pr(2))(12) are also reported.

Low-threshold, short-latency cutaneous reflexes evoked in ipsilateral hindlimb motor nerves were examined during fictive locomotion. Locomotion in 11 anaemically decerebrated spinal animals (1-3 weeks after transection at T13-L1) was induced by administration of clonidine, L-dopa and nialamide; by administration of the latter two drugs only; or by exteroceptive stimulation in the absence of any drugs. The caudal and lateral cutaneous sural, caudal cutaneous femoral, saphenous and superficial peroneal nerves were stimulated at low threshold (1.5-3 T). Pooled results from all combinations of cutaneous nerves stimulated and muscle nerves recorded show that the initial response was excitatory in 40 of 50 triceps surae and 17 of 20 semitendinosus (St) electroneurograms (ENGs). These excitatory responses occurred at latencies that ranged from 5 to 15 ms and tended to be maximal during the motor nerve's active period in the step cycle (i.e. they were modulated in a phase-dependent manner). Only three inhibitory responses (9-12 ms earliest latency) were encountered in total: in two St ENGs of one animal and in one lateral gastrocnemius-soleus ENG of a different animal. In two animals a "second" excitatory response (15-25 ms latency) was sometimes recorded in triceps surae and St nerves and, interestingly, could be modulated out of phase with the early response. Weak short-latency excitatory reflexes were also found in contralateral St ENGs when examined. Finally, among medial gastrocnemius, lateral gastrocnemius and soleus nerves, excitatory responses due to stimulation of any particular cutaneous nerve tended to be modulated similarly but were of consistently different amplitude among the three. This finding, together with the general observation that excitatory reflexes produced by stimulation of a particular cutaneous nerve were modulated similarly in extensors (or flexors) of different animals, suggests that spinal circuits generating locomotion may indeed exert a stereotypic control over interneurons in specific cutaneous reflex pathways to motoneurons. The results are primarily discussed in terms of the existing evidence for short-latency excitatory cutaneous reflexes in extensors in a variety of locomotive and non-locomotive preparations.

Adenosine deaminase (ADA) was detected immunohistochemically in neuronal cell bodies of dorsal root ganglia (DRG) of the rat. ADA-immunoreactivity was confined exclusively to small type B ganglion neurons in cervical, thoracic and lumbar sensory ganglia; large type A neurons in sensory ganglia were devoid of immunostaining for ADA. It was consistently found that only a small proportion of type B neurons in DRG contain immunohistochemically detectable ADA. It is suggested that the expression of high ADA levels is a distinguishing feature of a subpopulation of type B DRG neurons and, further, that ADA in these neurons may reflect their utilization of purines (adenosine or adenine nucleotides) as transmitters or cotransmitters.