Insight into the Varying Reactivity of Different Catalysts for CO2 Cycloaddition into Styrene Oxide: An Experimental and DFT Study.

The cycloaddition of CO2 into epoxides to form cyclic carbonates is a highly sought-after reaction for its potential to both reduce and use CO2, which is a greenhouse gas. In this paper, we present experimental and theoretical studies and a mechanistic approach for three catalytic systems. First, as Lewis base catalysts, imidazole and its derivatives, then as a Lewis acid catalyst, ZnI2 alone, and after that, the combined system of ZnI2 and imidazole. In the former, we aimed to discover the reasons for the varied reactivities of five Lewis base catalysts. Furthermore, we succeeded in reproducing the experimental results and trends using DFT. To add, we emphasized the importance of non-covalent interactions and their role in reactivity. In our case, the presence of a hydrogen bond was a key factor in decreasing the reactivity of some catalysts, thus leading to lower conversion rates. Finally, mechanistically understanding this 100% atom economy reaction can aid experimental chemists in designing better and more efficient catalytic systems.

Negotiation of Calcified Canals.

The gradual formation of hard tissue along the root canal walls is a natural process associated with aging, typically progressing slowly over time. In reaction to tooth wear, operative procedures, vital pulp treatments, or regenerative endodontic procedures, hard tissue may also accumulate within the pulp canal space at a slow rate. In certain cases, such as dental trauma, autotransplantation, or orthodontic treatment, this deposition of hard tissue can accelerate unexpectedly, resulting in rapid narrowing or complete closure of the root canal space. This situation is called calcific metamorphosis (CM), root canal calcification, or pulp canal obliteration (PCO). Performing conventional endodontic therapy on severely calcified canals presents significant challenges and increases the risk of procedural accidents. Calcified canals introduce such complexity that dedicated negotiation concepts and specially designed instruments have been developed to deal with the challenge. This article seeks to review the existing methods for effectively navigating calcified canals and to introduce the buckling resistance activation test (BRAT) technique.

Livestock-Forest integrated system attenuates deleterious heat stress effects in bovine oocytes.

Global warming poses significant challenges to the fertility of tropical dairy cattle. One promising approach to mitigate heat stress effects on reproductive function and reduce the carbon footprint is the use of integrated livestock-forest (ILF) systems. The aim of this study was to investigate the effects of two different systems, namely Full Sun (FS) and ILF, on maternal hyperthermia and oocyte quality of Holstein and Girolando heifers during the tropical summer season. The temperature-humidity index (THI) data revealed intense heat stress during the experiment. Both the system (P<0.01) and the breed (P<0.01) factors had a significant impact on vaginal temperature, being hyperthermia more pronounced in the FS system and in the Holstein breed. Over the five time points collected at a 33-day interval, we observed distinct patterns for ILF (P=0.65) and FS (P<0.001) systems, suggesting an adaptive response in animals kept in FS systems. Furthermore, oocyte quality assessment revealed an effect of the system for oocyte diameter (P<0.001) and levels of IGFBP2 (P<0.001), and caspase 3 levels showed a decrease in ILF compared to FS for both Holstein (P<0.001) and Girolando (P<0.001) breeds. Collectively, these parameters indicate that oocyte quality during the summer months was superior in animals maintained in the ILF system. In conclusion, the ILF system demonstrated promising results in attenuating maternal hyperthermia and mitigating its effects on oocyte quality. Additionally, our observations suggest that animals in the FS system may exhibit an adaptive response to heat stress.

Reproductive development of dairy heifers in an integrated livestock-forest system during the summer.

This study aimed to assess the cortisol, body and reproductive development of prepubertal Holstein and Holstein-Gir ¾ heifers at 27 months of age maintained in an integrated livestock-forest (ILF) system for 60 summer days compared to the monoculture system in full sun (FS). The ILF system promoted changes (P=0.02) in the cortisol levels of Holstein-Gir ¾ heifers and did not affect weight gain in any of the breed groups studied. Animals in ILF system presented a lower (P=0.006) vulvar development for the rima height parameter and similar for the vulva width parameter. The ovarian follicular population of Holstein-Gir ¾ heifers in the ILF system was lower (P=0.004); however, for the Holstein heifers, no statistical difference was found, and numbers were higher (P=0.08) in the ILF system. None of the other ovarian parameters studied had any changes, and we also found important racial differences. Weight gain (P=0.003), vulvar development (P<0.001), and mean follicular size (P=0.008) were higher in the Holstein-Gir ¾ animals. Based on such results, the effect of the ILF system at 27 months of age on stress and reproductive parameters in the Holstein breed is considered positive, although negative effects have been detected on reproductive parameters in the Holstein-Gir ¾ breed.

Application of computer-assisted dynamic navigation in complex root canal treatments: Report of two cases of calcified canals.

Root canal treatment and non-vital bleaching of teeth with pulp canal obliteration may represent a complex challenge to the clinician. This report describes the usefulness of the computer-assisted dynamic navigation system for the root canal treatment of two cases of teeth with a history of traumatic injury, extensively obliterated root canals and crown discoloration. Clinical and cone-beam computed tomographic evaluations were completed prior to procedures and 12 months after treatment. Both cases were treated using a computer-assisted dynamic navigation system coupled to a high-speed handpiece in order to establish the location and orientation of the partially obliterated canal and endodontic access route planning. The system allowed an accurate localisation of the root canal with a conservative access cavity. At the 12-month recall examination, the patients continue to be symptom-free, with a normal appearance of the mucogingival complex, adequate restoration of the tooth colour and intact periapical structures.

Methodological development of a quality index for agricultural operations, for corn cultivation using multi-criterion analysis.

One of the major problems in the Brazilian agriculture is related to the production loss in the field, which, due to many factors, is not being considered. This article has the objective to develop a methodology to identify a quality index which integrates some crop quality variables which are able to indicate how the crop is developing in terms of loss in the field. The results have showed that the strategy of multi-criterion analysis and Fuzzy logic proved to be important tools for the assessment and preparation of a quality index for corn production. The index proposed performed well in representing the quality of agricultural operations when compared with reality.

Effect of Subgingival Irrigation with Different Substances in the Treatment of Periodontal Disease. A Histometric Study in Rats.

The aim of this study was to evaluate the histometric effects of subgingival irrigation with different solutions as adjuvant for the treatment of periodontal disease in rats. Periodontal disease was induced by ligature in the first lower molars of 91 Wistar rats over the course of 28 days. After removal of the ligatures, the animals were subjected to scaling and root planing, followed by subgingival irrigation with different solutions (0.9% saline, 0.2% chlorhexidine, 0.1% and 0.5% sodium hypochlorite and 11% propolis extract). The animals were sacrificed 7 and 14 days after the treatment and tissue was processed for histometric analysis for evaluation of bone support and epithelial migration. The histometric analysis showed no statistically significant differences between the group treated with scaling and groups treated with subgingival irrigation (p > 0.05) regarding bone support and epithelial migration. Similarly, significant differences were not found among the different solutions used for subgingival irrigation. This study agrees with the position of the American Academy of Periodontology, which states that there is insufficient evidence to indicate the routine use of subgingival irrigation as adjuvant to periodontal treatment.

Integrated Monitoring of Mola mola Behaviour in Space and Time.

Over the last decade, ocean sunfish movements have been monitored worldwide using various satellite tracking methods. This study reports the near-real time monitoring of fine-scale (< 10 m) behaviour of sunfish. The study was conducted in southern Portugal in May 2014 and involved satellite tags and underwater and surface robotic vehicles to measure both the movements and the contextual environment of the fish. A total of four individuals were tracked using custom-made GPS satellite tags providing geolocation estimates of fine-scale resolution. These accurate positions further informed sunfish areas of restricted search (ARS), which were directly correlated to steep thermal frontal zones. Simultaneously, and for two different occasions, an Autonomous Underwater Vehicle (AUV) video-recorded the path of the tracked fish and detected buoyant particles in the water column. Importantly, the densities of these particles were also directly correlated to steep thermal gradients. Thus, both sunfish foraging behaviour (ARS) and possibly prey densities, were found to be influenced by analogous environmental conditions. In addition, the dynamic structure of the water transited by the tracked individuals was described by a Lagrangian modelling approach. The model informed the distribution of zooplankton in the region, both horizontally and in the water column, and the resultant simulated densities positively correlated with sunfish ARS behaviour estimator (rs = 0.184, p<0.001). The model also revealed that tracked fish opportunistically displace with respect to subsurface current flow. Thus, we show how physical forcing and current structure provide a rationale for a predator's fine-scale behaviour observed over a two weeks in May 2014.

CHMP1A encodes an essential regulator of BMI1-INK4A in cerebellar development.

Charged multivesicular body protein 1A (CHMP1A; also known as chromatin-modifying protein 1A) is a member of the ESCRT-III (endosomal sorting complex required for transport-III) complex but is also suggested to localize to the nuclear matrix and regulate chromatin structure. Here, we show that loss-of-function mutations in human CHMP1A cause reduced cerebellar size (pontocerebellar hypoplasia) and reduced cerebral cortical size (microcephaly). CHMP1A-mutant cells show impaired proliferation, with increased expression of INK4A, a negative regulator of stem cell proliferation. Chromatin immunoprecipitation suggests loss of the normal INK4A repression by BMI in these cells. Morpholino-based knockdown of zebrafish chmp1a resulted in brain defects resembling those seen after bmi1a and bmi1b knockdown, which were partially rescued by INK4A ortholog knockdown, further supporting links between CHMP1A and BMI1-mediated regulation of INK4A. Our results suggest that CHMP1A serves as a critical link between cytoplasmic signals and BMI1-mediated chromatin modifications that regulate proliferation of central nervous system progenitor cells.

Methodological development of a quality index for agricultural operations, for corn cultivation using multi-criterion analysis

One of the major problems in the Brazilian agriculture is related to the production loss in the field, which, due to many factors, is not being considered. This article has the objective to develop a methodology to identify a quality index which integrates some crop quality variables which are able to indicate how the crop is developing in terms of loss in the field. The results have showed that the strategy of multi-criterion analysis and Fuzzy logic proved to be important tools for the assessment and preparation of a quality index for corn production. The index proposed performed well in representing the quality of agricultural operations when compared with reality.

Um dos maiores problemas na agricultura brasileira refere-se à perda da produção no campo que, devido a vários fatores, não é considerada. Este artigo tem o objetivo de desenvolver uma metodologia para identificar um índice de qualidade que integre algumas variáveis qualitativas da cultura que são capazes de mostrar como está o desenvolvimento em termos de perda no campo. Os resultados mostraram que a análise de multicritério e lógica fuzzy são ferramentas importantes na verificação e confecção de um índice de qualidade de perdas, para a cultura do milho. O índice calculado representou bem a qualidade das operações agrícolas, quando comparado com a realidade.