Back-Donation in High-Valent d0 Metal Complexes: Does It Exist? the Case of NbV

In the last years, some N-heterocyclic carbene (NHC) complexes of high-valent d0 transition-metal halides have been structurally characterized, showing a significant short distance between the carbene carbon and the cis-halide ligands (Clax). Some authors attributed this arrangement to a halide â\u86\u92 Ccarbene unusual "back-donation", whereas, according to others, the M-carbene bond is purely Ï\u83. More, in general, the ability of d0 metal centers to provide back-donation to suitable ligands is still debated, and detailed bond analyses for this class of systems are missing in the literature. In this contribution, we analyze in detail the NbV-L bond within neutral, cationic, and anionic derivatives of NbCl5, with L = NHC, CO, CNH, and CN-. In [NbVCl6-x(NHC)x]x-1 complexes, with NHC being either a model carbene (1,3-dimethylimidazol-2-ylidene, IMe) or a realistic one [1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, IPr], we demonstrate that the metal center is really capable of back-donation to the carbene ligand by a charge flux that involves the chloride in the trans position and, directly, the metal. In this case, a direct interaction between Clax and Ccarbene can be excluded, while if different Ï\u80-acceptor ligands, such as CO or CNH, are used (instead of NHC), the direct Clax â\u86\u92 L interligand interaction becomes predominant

Geomorphology of the central Po Plain, Northern Italy

A micro-relief map (1:90,000 scale) and a geomorphological map (1:25,000 scale) of the central sector of the Po Plain (northern Italy) are presented. The geomorphological map represents fluvial and anthropogenic landforms as well as the distribution of the textures of superficial alluvial deposits. It resulted from the integration of different study methods, including remote sensing data analysis, field surveys and grain size analysis of superficial deposits. The micro-relief map was a fundamental tool for identifying many inconspicuous landforms. The geomorphological map can provide local authorities with useful information for correct territorial management and planning, in particular for seismic and flood hazard assessment

Mixed valence triiron complexes from the conjugation of [FeIFeI] and [FeII] complexes via intermolecular carbyne/alkyne coupling

We present a new synthetic strategy for obtaining mixed-valence triiron complexes where the metal centers are bridged by a novel, highly functionalized hydrocarbyl ligand. The alkynyl-vinyliminium complexes [Fe2Cp2(CO)(mu-CO){mu-eta(1):eta(3)-C(X-C equivalent to CH)CHCNMe2}]CF3SO3 (X = 4-C6H4, [2a1]CF3SO3; X = (CH2)(3), [2a2]CF3SO3) were synthesized in almost quantitative yields from the aminocarbyne precursor [Fe2Cp2(CO)(2)(mu-CO){mu-CNMe2}]CF3SO3, [1a]CF3SO3, and the di-alkynes HC equivalent to C-X-C equivalent to CH. Then, the ferracycle [Fe(Cp)(CO){C(NMe2)CH=C(4-C6H4C equivalent to CH)C(O)}], 4a1, was produced in 47% yield from the cleavage of [2a1]CF3SO3 promoted by pyrrolidine. Subsequent reactions of the acetonitrile adducts [Fe2Cp2(CO)(mu-CO)(NCMe){mu-CNMe(R)}]CF3SO3 (R = Me, [1a(ACN)]CF3SO3; R = Xyl, [1b(ACN)]CF3SO3) ([(FeFeI)-Fe-I]) with 4a1 ([Fe-II]) at room temperature resulted in the formation of [(FeFeFeII)-Fe-I-Fe-I] complexes [Fe2Cp2(CO)(mu-CO){mu-eta(1):eta(3)-C(X-C=CHC(NMe2)=FeCp(CO)C=O)CHCNMe(R)}]CF3SO3 (R = Me, [5a1]CF3SO3; R = Xyl, [5b1]CF3SO3) in yields ranging from 56% to 64%. The new products were characterized by IR and multinuclear NMR spectroscopy, and the structures of [2a2]CF(3)SO(3 )and 4a1 were confirmed by single crystal X-ray diffraction. Cyclic voltammetry and spectroelectrochemical studies on [5a1](+) have revealed that reduction and oxidation events occur almost independently at the [(FeFeI)-Fe-I] and [Fe-II] units, respectively. This observation underscores a minimal electronic interaction between the two fragments within the triiron complex. Accordingly, DFT studies pointed out that the HOMO and LUMO orbitals are predominantly localized in the two distinct compartments of [5a1](+

Potent in vitro antiproliferative properties for a triplatinum cluster toward triple negative breast cancer cells

The trinuclear platinum cluster [Pt3(μ-PBut2)3(CO)3]CF3SO3 (I) was designed featuring the presence of a nearly equilateral platinum triangle bridged by three di-tert-butylphosphide ligands; in addition, each platinum center bears a terminal carbonyl ligand. This triplatinum cluster was initially developed in view of applications in the field of cluster-containing innovative materials. Yet, due to the large success of platinum complexes in cancer treatment, we also decided to explore its cytotoxic and anticancer properties. Accordingly, the solubility profile of this compound in several solvents was preliminarily investigated, revealing a conspicuous solubility in DMSO and DMSO/buffer mixtures; this makes the biological testing of I amenable. UV–Vis measurements showed that the triplatinum cluster is stable for several hours under a variety of conditions, within aqueous environments. No measurable reactivity was observed for I toward two typical model proteins, i.e. lysozyme and cytochrome c. On the contrary, a significant reactivity was evidenced when reacting I with small sulfur-containing ligands. In particular, a pronounced reactivity with reduced glutathione and cysteine emerged from ESI-MS experiments, proving complete formation of I-GSH and I-Cys derivatives, with the loss of a single carbonyl ligand. Starting from these encouraging results, the cytotoxic potential of I was assayed in vitro against a panel of representative cancer cell lines, and potent cytotoxic properties were disclosed. Of particular interest is the finding that the triplatinum species manifests potent antiproliferative properties toward Triple Negative Breast Cancer Cells, often refractory to most anticancer drugs. Owing to the reported encouraging results, a more extensive biological and pharmacological evaluation of this Pt cluster is now warranted to better elucidate its mode of action

Increasing biases can be more efficient than increasing weights

We introduce a novel computational unit for neural networks that features multiple biases, challenging the traditional perceptron structure. This unit emphasizes the importance of preserving uncorrupted information as it is passed from one unit to the next, applying activation functions later in the process with specialized biases for each unit. Through both empirical and theoretical analyses, we show that by focusing on increasing biases rather than weights, there is potential for significant enhancement in a neural network model's performance. This approach offers an alternative perspective on optimizing information flow within neural networks. See source code at https://github.com/CuriosAI/dac-dev.Comment: Major rewriting. Supersedes v1 and v2. Focusing on the fact that not all parameters are born equal: biases can be more important than weights. Accordingly, new title and new abstract, and many more experiments on fully connected architectures. This is the extended version of the paper published at WACV 202

Efficacy of the additional use of subgingival air‑polishing with erythritol powder in the treatment of periodontitis patients: a randomized controlled clinical trial. Part II: effect on sub‑gingival microbiome

Objectives. To date, scarce evidence exists around the application of subgingival air-polishing during treatment of severe periodontitis. The aim of this study was to evaluate the effect on the health-related and periodontitis-related subgingival microbiome of air-polishing during non-surgical treatment of deep bleeding pockets in stage III–IV periodontitis patients. Materials and methods. Forty patients with stage III–IV periodontitis were selected, and pockets with probing depth (PD) 5–9 mm and bleeding on probing were selected as experimental sites. All patients underwent a full-mouth session of erythritol powder supragingival air-polishing and ultrasonic instrumentation. Test group received additional subgingival air-polishing at experimental sites. Subgingival microbial samples were taken from the maxillary experimental site showing the deepest PD at baseline. Primary outcome of the first part of the present study was the 3-month change in the number of experimental sites. Additional analysis of periodontal pathogens and other sub-gingival plaque bacteria sampled at one experimental site at baseline and 3 months following treatment was performed through a real-time quantitative PCR microarray. Results. In the test group, a statistical increase of some health-related species was observed (Abiotropha defectiva, Capnocytophaga sputigena, and Lautropia mirabilis), together with the decrease of pathogens such as of Actinomyces israelii, Catonella morbi, Filifactor alocis, Porphyromonas endodontalis, Sele-nomonas sputigena, Tannerella forsythia, Treponema denticola, and Treponema socranskii. In the control group, statistical significance was found only in the decrease of Filifactor alocis, Tannerella forsythia, and Treponema socranskii. Conclusions. The addition of erythritol-chlorhexidine powder seems to cause a shift of the periodontal microbiome toward a more eubiotic condition compared to a conventional treatment. The study was registered on Clinical Trials.gov (NCT04264624). Clinical relevance. Subgingival air-polishing could help re-establishing a eubiotic microbioma in deep bleeding periodontal pockets after initial non-surgical treatment

A simplified genomic profiling approach predicts outcome in metastatic colorectal cancer

The response of metastatic colorectal cancer (mCRC) to the first-line conventional combination therapy is highly variable, reflecting the elevated heterogeneity of the disease. The genetic alterations underlying this heterogeneity have been thoroughly characterized through omic approaches requiring elevated efforts and costs. In order to translate the knowledge of CRC molecular heterogeneity into a practical clinical approach, we utilized a simplified Next Generation Sequencing (NGS) based platform to screen a cohort of 77 patients treated with first-line conventional therapy. Samples were sequenced using a panel of hotspots and targeted regions of 22 genes commonly involved in CRC. This revealed 51 patients carrying actionable gene mutations, 22 of which carried druggable alterations. These mutations were frequently associated with additional genetic alterations. To take into account this molecular complexity and assisted by an unbiased bioinformatic analysis, we defined three subgroups of patients carrying distinct molecular patterns. We demonstrated these three molecular subgroups are associated with a different response to first-line conventional combination therapies. The best outcome was achieved in patients exclusively carrying mutations on TP53 and/or RAS genes. By contrast, in patients carrying mutations in any of the other genes, alone or associated with mutations of TP53/RAS, the expected response is much worse compared to patients with exclusive TP53/RAS mutations. Additionally, our data indicate that the standard approach has limited efficacy in patients without any mutations in the genes included in the panel. In conclusion, we identified a reliable and easy-to-use approach for a simplified molecular-based stratification of mCRC patients that predicts the efficacy of the first-line conventional combination therapy

Complete genome sequence of a serotype 11A, ST62 Streptococcus pneumoniae invasive isolate

<p>Abstract</p> <p>Background</p> <p><it>Streptococcus pneumoniae </it>is an important human pathogen representing a major cause of morbidity and mortality worldwide. We sequenced the genome of a serotype 11A, ST62 <it>S. pneumoniae </it>invasive isolate (AP200), that was erythromycin-resistant due to the presence of the <it>erm</it>(TR) determinant, and carried out analysis of the genome organization and comparison with other pneumococcal genomes.</p> <p>Results</p> <p>The genome sequence of <it>S. pneumoniae </it>AP200 is 2,130,580 base pair in length. The genome carries 2216 coding sequences (CDS), 56 tRNA, and 12 rRNA genes. Of the CDSs, 72.9% have a predicted biological known function. AP200 contains the pilus islet 2 and, although its phenotype corresponds to serotype 11A, it contains an 11D capsular locus. Chromosomal rearrangements resulting from a large inversion across the replication axis, and horizontal gene transfer events were observed. The chromosomal inversion is likely implicated in the rebalance of the chromosomal architecture affected by the insertions of two large exogenous elements, the <it>erm</it>(TR)-carrying Tn<it>1806 </it>and a functional prophage designated ϕSpn_200. Tn<it>1806 </it>is 52,457 bp in size and comprises 49 ORFs. Comparative analysis of Tn<it>1806 </it>revealed the presence of a similar genetic element or part of it in related species such as <it>Streptococcus pyogenes </it>and also in the anaerobic species <it>Finegoldia magna, Anaerococcus prevotii </it>and <it>Clostridium difficile</it>. The genome of ϕSpn_200 is 35,989 bp in size and is organized in 47 ORFs grouped into five functional modules. Prophages similar to ϕSpn_200 were found in pneumococci and in other streptococcal species, showing a high degree of exchange of functional modules. ϕSpn_200 viral particles have morphologic characteristics typical of the <it>Siphoviridae </it>family and are capable of infecting a pneumococcal recipient strain.</p> <p>Conclusions</p> <p>The sequence of <it>S. pneumoniae </it>AP200 chromosome revealed a dynamic genome, characterized by chromosomal rearrangements and horizontal gene transfers. The overall diversity of AP200 is driven mainly by the presence of the exogenous elements Tn<it>1806 </it>and ϕSpn_200 that show large gene exchanges with other genetic elements of different bacterial species. These genetic elements likely provide AP200 with additional genes, such as those conferring antibiotic-resistance, promoting its adaptation to the environment.</p

Gastritis and gastroesophageal reflux disease are strongly associated with non-allergic nasal disorders

Gastroesophageal reflux disease (GERD) has been reported to be significantly associated with chronic rhinosinusitis, but the strength of the association is still debated

The Italian version of the Depressive Experiences Questionnaire: psychometric properties and validation in students, community, and clinical groups

The current study evaluated the psychometric properties of the Italian validation of the Depressive Experiences Questionnaire (DEQ), conceived as a measure of self-criticism and dependency, i.e. two personality factors acting, according to Blatt (2004), as risk factors for depression in particular and psychopathology in general. A series of standardized measures [Beck Depression Inventory-II (BDI-II), DEQ, Symptom Checklist-90-R (SCL-90-R), Millon Clinical Multiaxial Inventory, 3rd edition (MCMI-III)] was administered to three samples (i.e., students, community and clinical). Factorial validity was evaluated along with convergent and predictive validity. In order to evaluate the reliability and internal consistency, a specific subgroup of participants was retested on the DEQ and BDI-II. Results showed correlations between DEQ dimensions and some personality traits of the MCMI-III. The traditional three-factor model of the DEQ structure as identified by principal component analysis appears to be as stable factors as typically found in American samples, although some items showed elevated cross-loading or low loadings on any factor. Clinical and diagnostic implications of the findings will be discussed