Intermediate Intercluster Bond Orders. Electronic Communication in Au38(SR)24 Superatomic Molecules.

Ligand-protected gold clusters remain potential building blocks for envisaged molecular materials. The archetypal Au38(SR)24 cluster can be viewed as a robust template for the fusion of two Au25(SR)18- cluster units, retaining a bi-icosahedral Au23 core. Via electrochemical properties, the overall charge state can be selectively tuned, enabling the access of 14 valence electron (ve) species featuring a single intercluster bond and nearby charge from -1 to +3, achieving related species bearing 15- to 11-ve with variable intercluster bond orders. Here, we explore the characteristics of intermediate intercluster bond orders in order to provide insights into the plausible electron communication between the constituent building blocks, with Au38(SR)24, as a representative template. Our results denote a small structural variation along -1 to +3 charge states, provided by the core-protecting ligand interaction, which is enhanced towards more oxidized species. The remaining unpaired electron from intermediate intercluster bond orders of 1.5 for Au38(SR)241-, 1.5 for Au38(SR)241+, and 2.5 for Au38(SR)243+, holds delocalized characteristics between the building block units, favoring electron communication for conductive and cooperative cluster aggregates. Such features are relevant for the formation of molecular electronic device applications, favoring the rationalization prior to engaging in explorative synthesis of larger ligand-protected cluster aggregates.

On the halide aggregation into the [Au4(PPh3)4]4+ cluster core. Insights from structural, optical and interaction energy analysis in [(Ph3PAu)4X2]2+ and [(Ph3PAu)4X]3+ species (X = Cl-, Br-, I-).

The aggregation of halide atoms into gold clusters offers an interesting scenario for the development of novel metal-based cavities for anion recognition and sensing applications. Thus, further understanding of the different contributing terms leading to efficient cluster-halide aggregation is relevant to guide their synthetic design. In this report, we evaluate the formation of [(Ph3PAu)4X2]2+ and [(Ph3PAu)4X]3+ species (X = Cl-, Br-, I-) in terms of different energy contributions underlying the stabilization of the cluster-halide interaction, and the expected UV-vis absorption profiles as a result of the variation in frontier orbital arrangements. Our results denote that a non-planar Au4 core shape enables enhanced halide aggregation, which is similar for Cl-, Br-, and I-, in comparison to the hypothetical planar Au4 counterparts. The electrostatic nature of the interaction involves a decreasing ion-dipole term along with the series, and for iodine species, higher-order electrostatic contributions become more relevant. Hence, the obtained results help in gaining further understanding of the different stabilizing and destabilizing contributions to suitable cluster-based cavities for the incorporation of different monoatomic anions.

An intercontinental comparison of the influence of smoking on the occurrence of nonsyndromic cleft lip and palate: a meta-analysis and systematic review.

BACKGROUND: The influence of smoking on nonsyndromic clefts has been a topic of research for many years. However, few studies have investigated the effect of smoking on causing clefts in different gene pools. METHODS: A meta-analysis was conducted of case-control studies related to smoking. Keywords such as "clefts," "cleft lip," "cleft palate," "orofacial cleft," and "smoking" were used to search the MEDLINE, Embase, and Cochrane databases. RESULTS: In total, 51 articles were reviewed. The RevMan software was utilized for the analysis, and the Mantel-Haenszel method was employed to pool the odds ratios (ORs) and 95% confidence intervals. Although the overall OR, a measure of the association between exposure and outcome, was higher for smokers than for non-smokers, this association was significantly stronger in individuals from Asia and South America (1.73), and lowest in Europe (1.31). Among active and passive smokers in Asia, the OR was approximately 0.93, indicating an equivalent impact from both types of smoking. CONCLUSION: This analysis indirectly suggests that restriction measures targeting both active and passive smoking are crucial in Asia.

Masticatory function in edentulous patients wearing implant overdentures after graftless maxillary sinus membrane elevation.

BACKGROUND: Graftless sinus floor augmentation shows good results in bone gain, radiology and implant survival. Clinically, this technique can be recommended as an alternative to conventional procedures using augmentation materials. OBJECTIVES: This study aims to assess masticatory performance, masticatory ability and patient satisfaction after graftless sinus floor augmentation. METHODS: The study group consisted of patients who had received a graftless sinus lift procedure in a split-mouth design and was compared to patients with maxillary implant-supported overdentures without augmentation and a natural dentition group. To assess objective masticatory performance, the mixing ability test was performed. Three questionnaires were used to assess patient reported outcomes related to mastication and patient satisfaction. RESULTS: Each group included ten patients. Both the graftless sinus lift group and the edentulous control group had a worse masticatory performance compared to the natural dentition group. Masticatory ability, measured by patient reported outcomes, was not different between the graftless sinus floor augmentation group and implant-retained overdentures group without augmentation, but the natural dentition group showed better results. Thereby, the better the masticatory performance in patients with a graftless sinus membrane elevation the better the patient satisfaction for 'prosthesis', 'appearance of prostheses', 'speech' and 'mastication and eating'. CONCLUSIONS: Patients with implant-supported overdentures show inferior masticatory function compared to those with natural dentition. There were no significant differences in masticatory performance between patients with implant-retained overdentures, with or without graftless augmentation. The decision on the preferred procedure should consider additional factors such as anatomical, surgical-technical aspects and patient's preferences.

Ligand-free supermolecules: [Pd2@Ge18]4- and [Pd2@Sn18]4- as multiple-bonded Zintl-ion clusters based on Pd@Ge9 and Pd@Sn9 assembled units.

Understanding intercluster bonding interactions is important in the rational synthesis of building blocks for molecular materials. Such characteristics have been developed for coinage metal clusters resembling single-, double-, and triple-bonded species, coined as supermolecules. Herein, we extend such an approach for understanding main-group clusters, thus evaluating [Pd2@E18]4- clusters (E = Ge, Sn) involving the fusion of parent spherical aromatic [Pd@E12]2- building units. Our results indicate intercluster bonding provided by contribution from 2P and 1G shells centered at each building motif, leading to an overall bond order of 2.70 and 2.31 for [Pd2@Ge18]4- and [Pd2@Sn18]4-, respectively. In addition, 119Sn-NMR patterns were evaluated to complement the experimental characterization of a single peak owing to the insolution fluxional behavior of [Pd2@Sn18]4- as three peaks owing to the three sets of unique Sn atoms within the structure. Magnetic response properties revealed that spherical aromatic characteristics from parent [Pd@E12]2- building units are retained in the overall [Pd2@E18]4- oblate cluster as two spherical aromatic units. Hence, the notion of superatomic molecules is extended to Zintl-ion clusters, favoring further rationalization for the fabrication of cluster-assembled solids.

[Ag(Sn9-Sn9)]5- and [(η4-Sn9)Ag(η1-Sn9)]7-, as aggregates of spherical aromatic building blocks. Persistence of aromaticity upon cluster gathering.

Formation of cluster-based materials requires a fundamental understanding of the resulting cluster aggregation processes. The Sn94- Zintl-ion structure can be viewed as a building block featuring a spherical aromatic species, leading to a cluster gathering upon oxidative coupling and/or mediated by transition metals. Here, we evaluate the spherical aromatic properties of [Sn9-Sn9]6-, [Ag(Sn9-Sn9)]5- and [(η4-Sn9)Ag(η1-Sn9)]7-, as aggregates of two Sn9 building units held together via oxidative coupling and mediated by a Ag(I) transition metal center. Our results from magnetic criteria of aromaticity show that the inherent spherical aromatic characteristics of the parent Sn94- cluster are persistent in the overall aggregate where the enabled shielding cones ascribed to each Sn9 unit are able to interplay between them, leading to an overlap of the shielding regions. Hence, the two approaches for bringing cluster units together are able to retain the inherent spherical aromatic features for each Sn9 unit, leading to a cluster-based dimer where the parent properties remain. Thus, further cluster-based materials can be envisaged from aggregation upon oxidative coupling and/or mediated by transition metals, where the constituent building blocks retain their initial features, useful to guide the formation of more complex cluster-based aggregates.

3D Niche-Inspired Scaffolds as a Stem Cell Delivery System for the Regeneration of the Osteochondral Interface.

The regeneration of the osteochondral unit represents a challenge due to the distinct cartilage and bone phases. Current strategies focus on the development of multiphasic scaffolds that recapitulate features of this complex unit and promote the differentiation of implanted bone-marrow derived stem cells (BMSCs). In doing so, challenges remain from the loss of stemness during in vitro expansion of the cells and the low control over stem cell activity at the interface with scaffolds in vitro and in vivo. Here, this work scaffolds inspired by the bone marrow niche that can recapitulate the natural healing process after injury. The construct comprises an internal depot of quiescent BMSCs, mimicking the bone marrow cavity, and an electrospun (ESP) capsule that "activates" the cells to migrate into an outer "differentiation-inducing" 3D printed unit functionalized with TGF-ß and BMP-2 peptides. In vitro, niche-inspired scaffolds retained a depot of nonproliferative cells capable of migrating and proliferating through the ESP capsule. Invasion of the 3D printed cavity results in location-specific cell differentiation, mineralization, secretion of alkaline phosphatase (ALP) and glycosaminoglycans (GAGs), and genetic upregulation of collagen II and collagen I. In vivo, niche-inspired scaffolds are biocompatible, promoted tissue formation in rat subcutaneous models, and regeneration of the osteochondral unit in rabbit models.

On the structure and electronic properties of Ptn clusters: new most stable structures for n = 16-17.

The lowest energy structures and electronic properties of Ptn clusters up to n = 17 are investigated by using a genetic algorithm in combination with density functional theory calculations. There are several putative global minimum structures for platinum clusters which have been reported by using different approaches, but a comprehensive study for n = 15-17 has not been carried out so far. Herein, we perform a consensus using GGA (PBE), meta-GGA (TPSS) and hybrid (B3PW91, PBE0, PBEh-3c, M06-L) functionals in conjunction with the Def2-TZVP basis set. New most stable structures are found for Pt16 and Pt17, which are slightly lower in energy than the previously reported global minima. Molecular dynamics simulations show that the clusters are rigid at room temperature. We analyze the structural, electronic, energy and vibrational data of the investigated clusters in detail.

Antifungal activity of Co(II) and Cu(II) complexes containing 1,3-bis(benzotriazol-1-yl)-propan-2-ol on the growth and virulence traits of fluconazole-resistant Candida species: synthesis, DFT calculations, and biological activity.

Relevant virulence traits in Candida spp. are associated with dimorphic change and biofilm formation, which became an important target to reduce antifungal resistance. In this work, Co(II) complexes containing a benzotriazole derivative ligand showed a promising capacity of reducing these virulence traits. These complexes exhibited higher antifungal activities than the free ligands against all the Candida albicans and non-albicans strains tested, where compounds 2 and 4 showed minimum inhibitory concentration values between 15.62 and 125 µg mL-1. Moreover, four complexes (2-5) of Co(II) and Cu(II) with benzotriazole ligand were synthesized. These compounds were obtained as air-stable solids and characterized by melting point, thermogravimetric analysis, infrared, Raman and ultraviolet/visible spectroscopy. The analysis of the characterization data allowed us to identify that all the complexes had 1:1 (M:L) stoichiometries. Additionally, Density Functional Theory calculations were carried out for 2 and 3 to propose a probable geometry of both compounds. The conformer Da of 2 was the most stable conformer according to the Energy Decomposition Analysis; while the conformers of 3 have a fluxional behavior in this analysis that did not allow us to determine the most probable conformer. These results provide an important platform for the design of new compounds with antifungal activities and the capacity to attack other target of relevance to reduce antimicrobial resistance.

The extent of unnecessary tooth loss due to extractions prior to radiotherapy based on radiation field and dose in patients with head and neck cancer.

BACKGROUND AND PURPOSE: Prior to radiotherapy (RT), teeth with poor prognosis that pose a risk for post-RT osteoradionecrosis (ORN) are removed. To allow enough time for adequate wound healing prior to RT, decisions are made based on the estimated radiation dose. This study aimed to gain insight into (1) the overall number of teeth extracted and (2) the patient and tumor characteristics associated with the number of redundantly extracted teeth. MATERIALS AND METHODS: Patients with head and neck cancer (HNC), treated with RT between 2015 and 2019, were included in this cross-sectional study. For each extracted tooth the radiation dose was calculated retrospectively. The cut-off point for valid extraction was set at ≥ 40 Gy in accordance with the national protocol. Potential factors for doses ≥ 40 Gy were identified, including age, sex, tumor location, tumor (T) and nodal stage (N), overall tumor stage and number of teeth extracted. RESULTS: A total of 1759 teeth were removed from 358 patients. Of these 1759 teeth, 1274 (74%) appeared to have been removed redundantly, based on the mean dose (Dmean) of < 40 Gy. Using the maximum dose (Dmax) of < 40 Gy, 1080 teeth (61%) appeared to have been removed redundantly. Tumor location and N-classification emerged as the most important associative variables in the multivariable regression analysis. CONCLUSION: To our knowledge this is the first study to provide insight into the amount of teeth redundantly extracted prior to RT and represents a step forward in de-escalating the damage to the masticatory system prior to RT.

Cl@Si20X20 cages: evaluation of encapsulation nature, structural rigidity, and 29Si-NMR patterns using relativistic DFT calculations.

The experimental characterization of Cl@Si20 endohedral clusters, featuring different ligands such as [Cl@Si20H20]- (1) [Cl@Si20H12Cl8]- (2), and [Cl@Si20Cl20]- (3), provides insight into the variable encapsulation environment for chloride anions. The favorable formation of such species enables the evaluation of the encapsulation nature and the role of the inner anion in the rigidity of the overall cluster. Our results show a sizable interaction which increases as -66.7, -100.8, and -130.3 kcal mol-1 from 1 to 3, respectively, featuring electrostatic character. The orbital interaction involves 3p-Cl → Si20X20 and 3s-Cl → Si20X20 charge transfer channels and a slight contribution from London dispersion-type interactions. These results show that the inner bonding environment can be modified by the choice of exobonded ligands. Moreover, 29Si-NMR parameters are depicted in terms of the chemical shift anisotropy (CSA), leading to a strong variation of the three principal tensor components (δ11, δ22, δ33), unraveling the origin of the experimental 29Si-NMR chemical shift (δiso) differences along the given series. Thus, the Si20 cage is a useful template to further evaluate different environments for encapsulating atomic species.

Neural Correlates of Tooth Clenching in Patients with Bruxism and Temporomandibular Disorder-Related Pain.

AIMS: To measure brain activity in patients with bruxism and temporomandibular disorder (TMD)-related pain in comparison to controls using functional magnetic resonance imaging (fMRI) and to investigate whether modulations in jaw clenching led to different pain reports and/or changes in neural activity in motor and pain processing areas within and between both groups. METHODS: A total of 40 participants (21 patients with bruxism and TMD-related pain and 19 healthy controls) performed a tooth-clenching task while lying inside a 3T MRI scanner. Participants were instructed to mildly or strongly clench their teeth for brief periods of 12 seconds and to subsequently rate their clenching intensity and pain experience after each clenching period. RESULTS: Patients reported significantly more pain during strong clenching compared to mild clenching. Further results showed significant differences between patients and controls in activity in areas of brain networks commonly associated with pain processing, which were also correlated with reported pain intensity. There was no evidence for differences in activity in motor-related areas between groups, which contrasts with findings of previous research. CONCLUSIONS: Brain activity in patients with bruxism and TMD-related pain is correlated more with pain processing than with motoric differences.

Correction: Structure effects of Pt15 clusters for the oxygen reduction reaction: first-principles calculations.

Correction for 'Structure effects of Pt15 clusters for the oxygen reduction reaction: first-principles calculations' by Peter L. Rodríguez-Kessler et al., Phys. Chem. Chem. Phys., 2023, https://doi.org/10.1039/d2cp05188e.

Structure effects of Pt15 clusters for the oxygen reduction reaction: first-principles calculations.

In the present work, the lowest energy structures and electronic properties of Pt15 clusters are investigated using molecular dynamics simulations. The results showed that the most stable configuration is a capped pyramidal structure, which is 0.8 kal mol-1 lower in energy than a layered structure previously reported [V. Kumar and Y. Kawazoe, Evolution of Atomic and Electronic Structure of Pt Clusters: Planar, Layered, Pyramidal, Cage, Cubic, and Octahedral Growth, Phys. Rev. B: Condens. Matter Mater. Phys., 2008, 77, 205418.]. The result is further confirmed by using both the PW91/cc-pVDZ-PP and PBE/PW approaches including the other representative isomers for Pt15. Due to the interesting structure arrangements found, we have investigated the catalytic activities for the oxygen reduction reaction. We found that the most stable Pt15 clusters are plausible catalyts for the ORR according to their interaction with oxygen species, which is consistent with experiments of Pt clusters with atomicity below 20. The results of the structure, electronic, adsorption and vibrational properties of the clusters are provided.

RANKL inhibition for giant cell lesions of the jaw: A retrospective cohort analysis.

BACKGROUND: In all giant-cell-rich lesions (GCRL) occurring in bone, a common underlying excessive RANKL expression is held responsible for the osteolytic activity. Apart from giant cell tumour of bone (GCTB), systematic outcome analysis of RANKL inhibition in other GCRL is unavailable. The aim of this study is to assess the efficacy and safety of a 1-year denosumab protocol in giant cell lesions of the jaw (GCLJ). METHODS: A retrospective cohort study was conducted compromising patients treated with a 1-year protocol of monthly subcutaneously administered 120 mg denosumab. Objective tumour response based on histology and imaging was used to calculate objective tumour response rate, progression-free survival (PFS) and time to progression. Type, severity and frequency of adverse events were recorded in a standardised way to assess safety. RESULTS: Twenty patients, predominantly female (90%), were included. Fifty-five per cent of lesions were located in the mandible; most classified as aggressive lesions (90%). Thirty-five per cent (7/20) of cases were either recurrent after prior treatment or progressive, while on other drug treatment. Objective tumour response rate was 100% after 12 months of treatment. Median PFS was 50.4 months (95% CI 38.0-62.8) with a cumulative PFS rate of 22.6% (95% CI 1.8-43.4) at 5 years follow-up. Median time to progression was 38.4 months (95% CI 26.0-50.8). Treatment was well tolerated, and none of the patients had to interrupt therapy for toxicity. CONCLUSION: High-dose denosumab is effective and safe in achieving a complete response in GCLJ within 12 months. The high long-term relapse rate after treatment cessation is the main obstacle for denosumab to become standard treatment for GCLJ.

Tooth extractions prior to chemoradiation or bioradiation are associated with weight loss during treatment for locally advanced oropharyngeal cancer.

PURPOSE: Prior to radiotherapy combined with chemotherapy (CRT) or biotherapy (BRT) for oropharyngeal squamous cell carcinoma (OPSCC), teeth with poor prognosis that pose a risk for post-RT osteoradionecrosis (ORN) are removed. The effect of tooth loss on body weight loss and tube feeding (TF) dependency during CRT/BRT is unknown. This study aimed to evaluate the effect of incomplete dentition, tooth extractions prior to CRT/BRT, and the subsequent loss of functional units on (1) weight loss during CRT/BRT and (2) the need for TF during CRT/BRT for OPSCC. METHODS: OPSCC patients treated with CRT/BRT between 2013 and 2016 were included in this retrospective cohort study. Dental status was determined during the dental assessment at first visit and after tooth extractions prior to the start of CRT/BRT. Weight loss during CRT/BRT was scored dichotomously, comparing weight loss > 5% to stable or increased weight. Potential factors associated with weight loss were identified, including patient, tumor, and treatment characteristics. RESULTS: Seventy-seven OPSCC patients were included. Forty patients (52%) experienced weight loss > 5% during CRT/BRT. Extractions were performed in 66% of the OPSCC patients. The mean number of extracted teeth was 4.1 ± 5.6 per patient. Tooth extractions prior to CRT/BRT were associated with weight loss > 5% during CRT/BRT (HR 1.130 (95% CI 1.011-1.262), p = 0.031). None of the dental status-related parameters showed any significant associative value for TF during CRT/BRT. CONCLUSIONS: Pre-CRT/BRT tooth extractions intended to reduce the risk of ORN, are a risk factor for weight loss during CRT/BRT for OPSCC. TRIAL REGISTRATION NUMBER: This study was approved by the medical ethics committee of the MUMC + (METC 2020-1589) on July 28, 2020.

Structural and electronic properties for Be-doped Ptn (n = 1-12) clusters obtained by DFT calculations.

In this work, we have performed a computational study on the structure and electronic properties for Be-doped Ptn (n = 1-12) clusters in the framework of density functional theory (DFT). The most stable structures of the clusters are obtained by a structure search procedure based in simulated annealing. The results show that the PtnBe clusters adopt compact structure motifs with Be situated at the edge sites while only in Pt11Be the Be atom occupies the center site. The energetic parameters showed that Pt5Be, Pt7Be and Pt10Be are the most stable ones. The PtnBe clusters with (n = 5-7) have similar vertical ionization potential (vIP) and vertical electron affinity (vEA) parameters compared to the unary Pt clusters, while Pt9Be and Pt11Be have the higher vEA values. In particular, the d-band center is slightly higher for the doped clusters, suggesting an enhanced reactivity. The σ-holes are found more remarkable for the doped clusters, which are situated in the Be dopant and low coordinated Pt sites. The data on the infrared spectra of the clusters is also provided and showed a significant blue shift due to the vibrational modes of the Be atom. These results are useful for understanding the fundamental properties of Be-doped Ptn clusters in the subnanometer region.

Relative Populations and IR Spectra of Cu38 Cluster at Finite Temperature Based on DFT and Statistical Thermodynamics Calculations.

The relative populations of Cu38 isomers depend to a great extent on the temperature. Density functional theory and nanothermodynamics can be combined to compute the geometrical optimization of isomers and their spectroscopic properties in an approximate manner. In this article, we investigate entropy-driven isomer distributions of Cu38 clusters and the effect of temperature on their IR spectra. An extensive, systematic global search is performed on the potential and free energy surfaces of Cu38 using a two-stage strategy to identify the lowest-energy structure and its low-energy neighbors. The effects of temperature on the populations and IR spectra are considered via Boltzmann factors. The computed IR spectrum of each isomer is multiplied by its corresponding Boltzmann weight at finite temperature. Then, they are summed together to produce a final temperature-dependent, Boltzmann-weighted spectrum. Our results show that the disordered structure dominates at high temperatures and the overall Boltzmann-weighted spectrum is composed of a mixture of spectra from several individual isomers.

Nature of hydride and halide encapsulation in Ag8 cages: insights from the structure and interaction energy of [Ag8(X){S2P(OiPr)2}6]+ (X = H-, F-, Cl-, Br-, I-) from relativistic DFT calculations.

Unraveling the different contributing terms to an efficient anion encapsulation is a relevant issue for further understanding of the underlying factors governing the formation of endohedral species. Herein, we explore the favorable encapsulation of hydride and halide anions in the [Ag8(X){S2P(OPr)2}6]+ (X- = H, 1, F, 2, Cl, 3, Br, 4, and, I, 5) series on the basis of relativistic DFT-D level of theory. The resulting Ag8-X interaction is sizable, which decreases along the series: -232.2 (1) > -192.1 (2) > -165.5 (3) > -158.0 (4) > -144.2 kcal mol-1 (5), denoting a more favorable inclusion of hydride and fluoride anions within the silver cage. Such interaction is mainly stabilized by the high contribution from electrostatic type interactions (80.9 av%), with a lesser contribution from charge-transfer (17.4 av%) and London type interactions (1.7 av%). Moreover, the ionic character of the electrostatic contributions decreases from 90.7% for hydride to 68.6% for the iodide counterpart, in line with the decrease in hardness according to the Pearson's acid-base concept (HSAB) owing to the major role of higher electrostatic interaction terms related to the softer (Lewis) bases. Lastly, the [Ag8{S2P(OPr)2}6]2+ cluster is able to adapt its geometry in order to maximize the interaction towards respective monoatomic anion, exhibiting structural flexibility. Such insights shed light on the physical reasoning necessary for a better understanding of the different stabilizing and destabilizing contributions related to metal-based cavities towards favorable incorporation of different monoatomic anions.