Late mortality among 5-year survivors of childhood cancer: A systematic review and meta-analysis.

BACKGROUND: Childhood cancer survivors are at increased risk of late mortality (death ≥5 years after diagnosis) from cancer recurrence and treatment-related late effects. The authors conducted a systematic review and meta-analysis to provide comprehensive estimates of late mortality risk among survivors internationally and to investigate differences in risk across world regions. METHODS: Health sciences databases were searched for cohort studies comprised of 5-year childhood cancer survivors in which the risk of mortality was evaluated across multiple cancer types. Eligible studies assessed all-cause mortality risk in survivors relative to the general population using the standardized mortality ratio (SMR). The absolute excess risk (AER) was assessed as a secondary measure to examine excess deaths. Cause-specific mortality risk was also assessed, if reported. SMRs from nonoverlapping cohorts were combined in subgroup meta-analysis, and the effect of world region was tested in univariate meta-regression. RESULTS: Nineteen studies were included, and cohort sizes ranged from 314 to 77,423 survivors. Throughout survivorship, SMRs for all-cause mortality generally declined, whereas AERs increased after 15-20 years from diagnosis in several cohorts. All-cause SMRs were significantly lower overall in North American studies than in European studies (relative SMR, 0.63; 95% confidence interval, 0.49-0.80). SMRs for subsequent malignant neoplasms and for cardiovascular, respiratory, and external causes did not vary significantly between world regions. CONCLUSIONS: The current findings suggest that late mortality risk may differ significantly between world regions, but these conclusions are based on a limited number of studies with considerable heterogeneity. Reasons for regional differences remain unclear but may be better elucidated through future analyses of individual-level data.

MultiCenter Study of Intra-Abdominal Abscess Formation After Major Operative Hepatic Trauma.

INTRODUCTION: One of the significant complications of operative liver trauma is intra-abdominal abscesses (IAA). The objective of this study was to determine risk factors associated with postoperative IAA in surgical patients with major operative liver trauma. METHODS: A retrospective multi-institutional study was performed at 13 Level 1 and Level 2 trauma centers from 2012 to 2021. Adult patients with major liver trauma (grade 3 and higher) requiring operative management were enrolled. Univariate and multivariate analyses were performed. RESULTS: Three hundred seventy-two patients were included with 21.2% (n = 79/372) developing an IAA. No difference was found for age, gender, injury severity score, liver injury grade, and liver resections in patients between the groups (P > 0.05). Penetrating mechanism of injury (odds ratio (OR) 3.42, 95% confidence interval (CI) 1.54-7.57, P = 0.02), intraoperative massive transfusion protocol (OR 2.43, 95% CI 1.23-4.79, P = 0.01), biloma/bile leak (OR 2.14, 95% CI 1.01-4.53, P = 0.04), hospital length of stay (OR 1.04, 95% CI 1.02-1.06, P < 0.001), and additional intra-abdominal injuries (OR 2.27, 95% CI 1.09-4.72, P = 0.03) were independent risk factors for IAA. Intra-abdominal drains, damage control laparotomy, total units of packed red blood cells, number of days with an open abdomen, total abdominal surgeries, and blood loss during surgery were not found to be associated with a higher risk of IAA. CONCLUSIONS: Patients with penetrating trauma, massive transfusion protocol activation, longer hospital length of stay, and injuries to other intra-abdominal organs were at higher risk for the development of an IAA following operative liver trauma. Results from this study could help to refine existing guidelines for managing complex operative traumatic liver injuries.

Artificial Graphene Spin Polarized Electrode for Magnetic Tunnel Junctions.

2D materials offer the ability to expose their electronic structure to manipulations by a proximity effect. This could be harnessed to craft properties of 2D interfaces and van der Waals heterostructures in devices and quantum materials. We explore the possibility to create an artificial spin polarized electrode from graphene through proximity interaction with a ferromagnetic insulator to be used in a magnetic tunnel junction (MTJ). Ferromagnetic insulator/graphene artificial electrodes were fabricated and integrated in MTJs based on spin analyzers. Evidence of the emergence of spin polarization in proximitized graphene layers was observed through the occurrence of tunnel magnetoresistance. We deduced a spin dependent splitting of graphene's Dirac band structure (∼15 meV) induced by the proximity effect, potentially leading to full spin polarization and opening the way to gating. The extracted spin signals illustrate the potential of 2D quantum materials based on proximity effects to craft spintronics functionalities, from vertical MTJs memory cells to logic circuits.

Oral squamous cell carcinomas and oral potentially malignant disorders: A Latin American study.

OBJECTIVE: To determine the frequency of oral squamous cell carcinoma (OSCC) associated or not with oral potentially malignant disorders (OPMD), and the epidemiological profile and traditional risk factors in Latin America. METHODS: A retrospective observational study was conducted in 17 Latin American centres. There were included cases of OSCC, analysing age, gender, OSCC and their association with previous OPMD. Clinicopathological variables were retrieved. The condition of sequential-OSCC versus OSCC-de novo (OSCC-dn) was analysed concerning the aforementioned variables. Quantitative variables were analysed using Student's t-test, and qualitative variables with chi-square. RESULTS: In total, 2705 OSCC were included with a mean age of 62.8 years old. 55.8% were men. 53.75% of the patients were smokers and 38% were common drinkers. The lateral tongue border was the most affected site (24.65%). There were regional variations in OPMD, being leukoplakia the most frequent. Of the overall 2705 OSCC cases, 81.4% corresponded to OSCC-dn, while s-OSCC were 18.6%. Regarding lip vermillion SCC, 35.7% corresponded to de novo lip SCC and 64.3% were associated with previous OPMD. CONCLUSIONS: In Latin America, OSCC-dn seems to be more frequent with regional variations of some clinical and histopathological features. Further prospective studies are needed to analyse this phenomenon.

Transcriptomic alterations in hypertrophy of the ligamentum flavum: interactions of Rho GTPases, RTK, PIK3, and FGF.

PURPOSE: To analyze the differential transcriptome expression in hypertrophic ligaments flavum (HLF) compared to normal ligaments. METHODS: A case-control study was conducted that included 15 patients with hypertrophy of LF and 15 controls. Samples of LF were obtained through a lumbar laminectomy and analyzed by DNA microarrays and histology. The dysregulated biological processes, signaling pathways, and pathological markers in the HLF were identified using bioinformatics tools. RESULTS: The HLF had notable histological alterations, including hyalinosis, leukocyte infiltration, and disarrangement of collagen fibers. Transcriptomic analysis showed that up-regulated genes were associated with the signaling pathways of Rho GTPases, receptor tyrosine kinases (RTK), fibroblast growth factors (FGF), WNT, vascular endothelial growth factor, phosphoinositide 3-kinase (PIK3), mitogen-activated protein kinases, and immune system. The genes PIK3R1, RHOA, RPS27A, CDC42, VAV1, and FGF5, 9, 18, and 19 were highlighted as crucial markers in HLF. The down-expressed genes in the HLF had associations with the metabolism of RNA and proteins. CONCLUSION: Our results suggest that abnormal processes in hypertrophied LF are mediated by the interaction of the Rho GTPase, RTK, and PI3K pathways, which have not been previously described in the HLF, but for which there are currently therapeutic proposals. More studies are required to confirm the therapeutic potential of the pathways and mediators described in our results.

Clinical Health Outcomes of Siblings of Children with Chronic Conditions: A Systematic Review and Meta-Analysis.

OBJECTIVE: The objective of the study was to assess clinical mental and physical health outcomes of siblings of children with chronic health condition(s) compared with siblings of healthy children or normative data. STUDY DESIGN: We searched Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials, PsycINFO, and CINAHL through August 9, 2021. We included English-language studies that reported clinically diagnosable mental or physical health outcomes among siblings of children (<18 years old) with a chronic health condition, included a comparison group, and used an experimental or observational study design. Two reviewers extracted data and independently assessed risk of bias using the Newcastle Ottawa Scale. RESULTS: Of 9899 screened studies, 34 were included; 28 studies reported on mental health, 3 reported on physical health, and 3 reported on mortality. Siblings of children with chronic conditions had greater depression rating scale scores than their comparison groups (standardized mean difference = 0.53; 95% CI = 0.38-0.68; P < .001 [6 studies]), whereas anxiety scores were not substantially increased (standardized mean difference = 0.21; 95% CI = -0.02 to 0.43; P = .07 [7 studies]). The effects for confirmed psychiatric diagnoses (7 studies), mortality (3 studies), or physical health outcomes (3 studies) could not be meta-analyzed given the limited number of studies and between-study heterogeneity. CONCLUSION: Siblings of children with chronic health conditions may be at an increased risk of depression. Our findings suggest the need for targeted interventions to support the psychological well-being of siblings of children with chronic health conditions.

[Prescription of antibiotics in acute respiratory infections non-pneumonia in a private outpatient practice]. / Prescripción de antibióticos en las infecciones respiratorias agudas no neumonías en atención ambulatoria en la práctica privada.

BACKGROUND: The over prescription of antibiotics for acute respiratory infections is a major public health problem worldwide. AIM: To evaluate the frequency of prescription of antibiotics for non-pneumonia acute respiratory infections in private outpatient clinics in individuals without chronic diseases or immunosuppression. MATERIAL AND METHODS: All medical records of adult consultants in a national network of private ambulatory medical centers during May 2018 whose primary diagnosis corresponded to acute respiratory infections not pneumonia (ICD10) were identified and retrospectively analyzed, excluding those with chronic respiratory conditions or states of immunosuppression. RESULTS: Of the 38,072 consultants (aged 36 years, 63% women) who met this criterion, 54% (n = 20,499) received a prescription for at least one antibiotic. The diagnoses that most frequently received this prescription were acute bronchitis (28.7%), acute sinusitis (16.5%) and acute tonsillitis (16.2%). The most frequently prescribed antibiotic globally was azithromycin (37.4%), followed by amoxicillin (20.1%) and amoxicillin plus clavulanic acid (17.7%). Levofloxacin prescription reached 12.5% of total prescriptions. CONCLUSIONS: An antibiotic was prescribed in more than half of the non-pneumonia outpatient acute respiratory infections. Azithromycin was the most prescribed antibiotic, while levofloxacin exceeded 10% of prescriptions. These results reinforce the need to implement an antibiotic prescription surveillance system at the outpatient level.

Aqueous Chemical Solution Deposition of Functional Double Perovskite Epitaxial Thin Films.

Double perovskite structure (A2 BB'O6 ) oxides exhibit a breadth of multifunctional properties with a huge potential range of applications in fields as diverse as spintronics, magneto-optic devices, or catalysis, and most of these applications require the use of thin films and heterostructures. Chemical solution deposition techniques are appearing as a very promising methodology to achieve epitaxial oxide thin films combining high performance with high throughput and low cost. In addition, the physical properties of these materials are strongly dependent on the ordered arrangement of cations in the double perovskite structure. Thus, promoting spontaneous cationic ordering has become a relevant issue. In this work, our recent achievements by using polymer-assisted deposition (PAD) of environmentally friendly, water-based solutions for the growth of epitaxial ferromagnetic insulating double perovskite La2 CoMnO6 and La2 NiMnO6 thin films on SrTiO3 and LaAlO3 single-crystal substrates are presented. It is shown that the particular crystallization and growth process conditions of PAD (very slow rate, close to thermodynamic equilibrium conditions) promote high crystallinity and quality of the films, as well as favors spontaneous B-site cationic ordering.

Efficacy and safety of Dentoxol® in the prevention of radiation-induced oral mucositis in head and neck cancer patients (ESDOM): a randomized, multicenter, double-blind, placebo-controlled, phase II trial.

PURPOSE: The aim of this study was to assess the efficacy and safety of Dentoxol mouthrinse in reducing the severity of oral mucositis (OM) secondary to radiation therapy (RT) for head and neck cancer. METHODS: A randomized, double-blind, placebo-controlled, multicenter phase II clinical trial was conducted. Subjects were asked to use Dentoxol (n = 55) or control (n = 53) mouthrinse 5 times/day during RT. Twice a week, OM was assessed clinically using the WHO scale and the Oral Mucositis Daily Questionnaire (OMDQ) was completed. RESULTS: The incidence of severe OM was 40.7% in the Dentoxol group and 51% in the control group (p = 0.265). Comparing all recorded clinical assessments, severe OM was seen in 13.3% of all assessments in the Dentoxol group vs. 21.8% in the control group (p = 0.000). There was a statistically significant lower proportion of assessments showing severe OM in the Dentoxol group at weeks 4, 5, and 6 of RT. The mean duration of severe OM was 11.95 days in the Dentoxol group vs. 14.59 days in the control group (p = 0.502). There was no difference between groups in mouth pain and its impact on function. The use of Dentoxol was safe and was not linked to any serious adverse events. CONCLUSION: The use of Dentoxol 5 times/day is safe and resulted in significantly fewer time-points with severe OM and a delay in the onset of severe OM, compared with a control rinse. A phase III clinical trial is warranted to confirm efficacy and address the limitations of this study.

Combining autologous particulate dentin, L-PRF, and fibrinogen to create a matrix for predictable ridge preservation: a pilot clinical study.

OBJECTIVES: The aim of this study was to describe the histological and clinical outcome of "dentin block" (a mixture of autologous particulate dentin, leukocyte- and platelet-rich fibrin (L-PRF), and liquid fibrinogen) in alveolar ridge preservation. MATERIAL AND METHODS: Ten extraction sockets were grafted with "dentin block," a mixture of particulate autologous dentin with chopped leukocyte-platelet-rich fibrin (L-PRF) membranes at a 1:1 ratio, and liquid fibrinogen as a binder. Two grafted sites were followed at 4 and 5 months, and 6 sites at 6 months. Biopsies were taken from the core of the grafted site for histologic and histo-morphometric analysis. RESULTS: All patients completed the study without any adverse event. The vertical and horizontal dimensions of the alveolar ridge were preserved or even increased after 4, 5, or 6 months and remained stable after 6 months of the implant placement. The histological examination revealed a median relative percentage of bone, dentin, and connective tissue of 57.0, 0.9, and 39.3%, respectively. A comparison of samples at different time points (4, 5, and 6 months) showed a progressive increase in the proportion of bone with a decrease in the proportion of dentin. The bone was compact with normal osteocytes and moderate osteoblastic activity. In 4 out of 10 samples, no dentin was observed; in the other samples, it represented 1-5% (with geometric fragments). CONCLUSIONS: Dentin block showed to be a suitable bone substitute in an alveolar ridges preservation model. CLINICAL RELEVANCE: The promising results of dentin block as a bone substitute in alveolar ridge preservation could have an important clinical impact considering this biomaterial brings together the regenerative potential of three autologous products with excellent biological and clinical behavior, low risk of adverse effects, and feasible acquisition.

Cavity Ring-Down Methane Sensor for Small Unmanned Aerial Systems.

We present the development, integration, and testing of an open-path cavity ring-down spectroscopy (CRDS) methane sensor for deployment on small unmanned aerial systems (sUAS). The open-path configuration used here (without pump or flow-cell) enables a low mass (4 kg) and low power (12 W) instrument that can be readily integrated to sUAS, defined here as having all-up mass of <25 kg. The instrument uses a compact telecom style laser at 1651 nm (near-infrared) and a linear 2-mirror high-finesse cavity. We show test results of flying the sensor on a DJI Matrice 600 hexacopter sUAS. The high sensitivity of the CRDS method allows sensitive methane detection with a precision of ~10-30 ppb demonstrated for actual flight conditions. A controlled release setup, where known mass flows are delivered, was used to simulate point-source methane emissions. Examples of methane plume detection from flight tests suggest that isolated plumes from sources with a mass flow as low as ~0.005 g/s can be detected. The sUAS sensor should have utility for emissions monitoring and quantification from natural gas infrastructure. To the best of our knowledge, it is also the first CRDS sensor directly deployed onboard an sUAS.

Open-path cavity ring-down methane sensor for mobile monitoring of natural gas emissions.

We present the design, development, and testing results of a novel laser-based cavity ring-down spectroscopy (CRDS) sensor for methane detection. The sensor is specifically oriented for mobile (i.e. vehicle deployed) monitoring of natural gas emissions from oil and infrastructure. In contrast to most commercial CRDS sensors, we employ an open-path design which allows higher temporal response and a lower power and mass package more suited to vehicle integration. The system operates in the near-infrared (NIR) at 1651 nm with primarily telecom components and includes cellular communication for wireless data transfer. Along with basic sensor design and lab testing, we present results of field measurements showing performance over a range of ambient conditions and examples of methane plume detection.

Relationship Between Nostril, Nasal Valve and Minimal Cross-Sectional Area in Functional Upper Airway.

PURPOSE: To propose a three-dimensional cephalometric analysis of upper airway (UA) related to its functionality, defining normal reference values in healthy individuals and the relationship between nostril, nasal valve, and minimal cross-sectional area (MCS) in functional upper airway. MATERIALS AND METHODS: The UAs of 20 Class I patients were analyzed with CBCT using Nemoceph 3D-OS and HOROS software, determining linear distances, volumes and cross-sectional areas, including MCS. RESULTS: MCS was mostly located in the middle-upper oropharynx and high hypopharynx. MCS showed moderate correlation with the area of both nares (BNA) (r = 0.60, P = 0.004) and high correlation with the area of both internal nasal valves (BNV) (r = 0.66, P = 0.0016). BNA and BNV showed a moderate correlation (r = 0.445, P = 0.049). A total upper airway (TUA) and functional upper airway (FUA) volumes were established. TUA and FUA showed the strongest statistical correlation (r = 0.82, P = 0.00). A paired samples t test compared the measurement as absolute values of MCS with BNA (t = 0.781, P = 0.44), with BNV (t = -0.12, P = 0.90); and BNA with BNV (t = -0.76, P = 0.45), showed no significant differences. CONCLUSIONS: A functional cephalometric analysis of the UA with stable parameters in cervical spine and normal reference values has been proposed. BNA and BNV could be used as reference to establish the MCS compatible with respiratory health.

[Frequency of oral squamous cell carcinoma and oral epithelial dysplasia in oral and oropharyngeal mucosa in Chile]. / Frecuencia de displasia epitelial y carcinoma escamoso en mucosa oral y orofaríngea en Chile, entre los años 1990 y 2009.

BACKGROUND: Oral cancer in Chile corresponds approximately to 1.6% of all cancer cases. There are few studies about oral epithelial dysplasia and oral squamous cell carcinoma in the Chilean population. AIM: To determine the frequency of hyperkeratosis, mild, moderate and severe oral epithelial dysplasia, in situ carcinoma and squamous cell carcinoma of the oral and oropharyngeal mucosa in a registry of the Oral Pathology Reference Institute of the Faculty of Dentistry, Universidad de Chile, in a ten years period. MATERIAL AND METHODS: Review of clinical records and pathological plates of 389 patients, obtained between 1990 and 2009. Cases were selected according to their pathological diagnosis, including hyperkeratosis, oral epithelial dysplasia, in situ carcinoma, squamous cell carcinoma and verrucous carcinoma. RESULTS: Forty four percent of cases were squamous cell carcinoma, followed by hyperkeratosis in 37% and mild epithelial dysplasia in 11%. Squamous cell carcinoma was more common in men aged over 50 years. Most of the potentially malignant disorders presented clinically as leukoplakia and squamous cell carcinoma were clinically recognized as cancer. CONCLUSIONS: In this study, men aged over 50 years are the highest risk group for oral cancer. Early diagnosis is deficient since most of these lesions were diagnosed when squamous cell carcinoma became invasive. Leukoplakia diagnosis is mostly associated with hyperkeratosis and epithelial dysplasia, therefore biopsy of these lesions is mandatory to improve early diagnosis.

Effect of periodontal treatment on preterm birth rate: a systematic review of meta-analyses.

Preterm birth is a major cause of neonatal morbidity and mortality in both developed and developing countries. Preterm birth is a highly complex syndrome that includes distinct clinical subtypes in which many different causes may be involved. The results of epidemiological, molecular, microbiological and animal-model studies support a positive association between maternal periodontal disease and preterm birth. However, the results of intervention studies carried out to determine the effect of periodontal treatment on reducing the risk of preterm birth are controversial. This systematic review critically analyzes the methodological issues of meta-analyses of the studies to determine the effect of periodontal treatment to reduce preterm birth. The quality of the individual randomized clinical trials selected is of highest relevance for a systematic review. This article describes the methodological features that should be identified a priori and assessed individually to determine the quality of a randomized controlled trial performed to evaluate the effect of periodontal treatment on pregnancy outcomes. The AMSTAR and the PRISMA checklist tools were used to assess the quality of the six meta-analyses selected, and the bias domain of the Cochrane Collaboration's Tool was applied to evaluate each of the trials included in the meta-analyses. In addition, the methodological characteristics of each clinical trial were assessed. The majority of the trials included in the meta-analyses have significant methodological flaws that threaten their internal validity. The lack of effect of periodontal treatment on preterm birth rate concluded by four meta-analyses, and the positive effect of treatment for reducing preterm birth risk concluded by the remaining two meta-analyses are not based on consistent scientific evidence. Well-conducted randomized controlled trials using rigorous methodology, including appropriate definition of the exposure, adequate control of confounders for preterm birth and application of effective periodontal interventions to eliminate periodontal infection, are needed to confirm the positive association between periodontal disease and preterm birth.

Reconstruction of Temporomandibular Joint With a Fibula Free Flap: A Case Report With a Histological Study.

Reconstruction of the temporomandibular joint (TMJ) for congenital or acquired deformities is a major challenge for maxillofacial surgeons. The alternatives for reconstructing the TMJ include free grafts (costochondral, iliac crest, clavicle, or metatarsus), free flaps (fibula), osteogenic distraction, and alloplastic grafts. The lack of biological knowledge of cartilaginous grafts and their reaction to the environment of the TMJ is largely responsible for the inability to predict growth. This report describes the use of a free flap for TMJ reconstruction.

The communities of helminth parasites of Heterandria bimaculata (Teleostei: Poeciliidae) from the upper Río La Antigua basin, east-central Mexico show a predictable structure.

We investigated a basic generalization in parasite community ecology stating that stochastic processes played a major part in determining the composition of helminth communities of freshwater fish, or on the contrary, if these communities are predictable, diverse and structured species assemblages. We determined the species pool of helminth parasites of a tropical freshwater fish Heterandria bimaculata in its heartland, the upper Río La Antigua basin in east-central Mexico. Approaching our data from the metapopulation standpoint we studied the spatial patterns, and examined the variation in composition and richness of the component communities across different locations. We tested the prediction that helminth species may be recognized as common or rare; and also two hypotheses anticipating depauperate communities and decay of similarity between component communities with increasing distance. We found these communities composed by a highly structured and predictable set of specialist autogenic helminth species that are constant and abundant, dominating all components throughout space. The prediction that it is possible to recognize common and rare species was met. Richer than expected communities were found, as well as highly homogeneous component communities, where neighbouring components were more similar than distant ones. We speculated that the processes shaping the development of these component communities include stable, predictable habitats through time, allowing for a slow gradual dispersion process limited by host and parasite species capabilities. Our study suggests that metapopulation theory can assist in the prediction of community composition and in the understanding of spatial and temporal community variability.

Evaluation of Sputtering Processes in Strontium Iridate Thin Films.

The growth of epitaxial thin films from the Ruddlesden-Popper series of strontium iridates by magnetron sputtering is analyzed. It was found that, even using a non-stoichiometric target, the films formed under various conditions were consistently of the perovskite-like n = ∞ SrIrO3 phase, with no evidence of other RP series phases. A detailed inspection of the temperature-oxygen phase diagram underscored that kinetics mechanisms prevail over thermodynamics considerations. The analysis of the angular distribution of sputtered iridium and strontium species indicated clearly different spatial distribution patterns. Additionally, significant backsputtering was detected at elevated temperatures. Thus, it is assumed that the interplay between these two kinetic phenomena is at the origin of the preferential nucleation of the SrIrO3 phase. In addition, strategies for controlling cation stoichiometry off-axis have also been explored. Finally, the long-term stability of the films has been demonstrated.

Taxonomic distinctness and diversity patterns of a polychaete (Annelida) community on the continental shelf of the Southern Gulf of Mexico.

The spatial patterns of taxonomic diversity of annelid polychaete species from the continental shelf in the Southern Gulf of Mexico were examined in this study. We used taxonomic distinctness and its spatial variations to explore the diversity patterns and how they change between Southern Gulf of Mexico regions. In addition, using taxonomic distinctness as a dissimilarity measure and Ward's Clustering, we characterized three distinct faunal assemblages. We also investigated patterns of richness, taxonomic distinctness, and distance decay of similarity between sampling stations as a ß-diversity measure. Finally, we examined the spatial relationships between polychaete assemblages and environmental variables to test the relative importance of spatial and environmental components in annelid polychaete community structure from the Southern Gulf of Mexico. We used a combination of eigenvector-based multivariate analyses (dbMEMs) and distance-based redundancy analysis (dbRDA) to quantify the relative importance of these explanatory variables on the spatial variations of taxonomic distinctness. The significance level of spatial and environmental components to the distribution of polychaete species showed that the combined effect of spatial processes and sediment characteristics explained a higher percentage of the variance than those parameters could alone.

Unraveling the role of internal-external metal substitution in Zn3[Co(CN6)]2 for the styrene oxide-CO2 cycloaddition reaction.

We investigated the influence of the structural and textural properties along with the chemical environment of pure Zn3[Co(CN)6]2 in comparison with the modified phases on the catalytic performance in the cycloaddition reaction between styrene oxide and CO2. We relate these to the proposed reaction pathways and mechanisms. The natural cubic phase (ZnCoCn) was dehydrated to obtain the rhombohedral phase (ZnCoRn), while the stabilized cubic phase (ZnCoCs) was synthesized by substituting external zinc atoms with cadmium atoms. The rhombohedral stabilized phase (ZnCoRs) was achieved by the internal cobalt change with iron. All the materials were extensively characterized using X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray photoelectron spectroscopy (XPS), and N2 adsorption. The catalytic behavior of the four phases was tested. The crystalline structure of each phase was obtained, and by XPS, it was demonstrated that the chemical environments of all elements conforming to the rhombohedral stabilized phase are different from those of all other materials owing to the exchange of internal metals. The bulk textural properties were similar; only the ZnCoRs presented more micropore area but did not exceed the total surface area of the other materials. The product distribution and yield at reaction times of 2 h and 6 h were closer to those of the cubic phases. The natural rhombohedral phase exhibits the best performance. The tetrabutylammonium bromide (TBAB) and rhombohedral stabilized phase work together to yield a bigger copolymer quantity at the expense of the styrene carbonate (StCO3) production. From the proposed mechanism, the TBAB cation (TBA+) has a "protection" function that drives the closing of the StCO3 ring; however, the charge distribution anisotropy in the four nitrogen atoms generated by Co replacement in ZnCoRs could hold TBA+ as the reaction time progressed, causing an unavailability that triggered the copolymerization propagation step.