Adaptable leadership for arid/semi-arid wetlands conservation under climate change: Using Analytical Hierarchy Process (AHP) approach.

Adverse socio-economic and environmental impacts of climate change on wetlands have enforced the international community and many nations to develop adaptive policies for wetland management, which require effective leadership to influence relevant stakeholders. This study identifies and prioritizes leadership functions and theories for climate change adaptation (CCA) in wetlands ecosystems, particularly in arid and semi-arid regions. A mixed qualitative-quantitative research methodology was applied through focus groups and a survey with a sample of national, sub-national, and local experts on wetlands management and climate change in Iran. The Analytic Hierarchy Processing (AHP) technique identified the political-administrative (weight = 0.245), adaptive (W = 0.244), and enabling (W = 0.237) functions for CCA, respectively, as three prioritized leadership functions, followed by the dissemination function (W = 0.102), which emphasizes the necessity of applying and enhancing leaders' social capacities, knowledge, communication skills, and personal networks to facilitate social learning and actions regarding CCA in local communities and among relevant organizations. It is necessary to overcome structural and functional barriers for leaders and their followers to information access and involvement in participatory decision-making platforms. Moreover, network and communication leadership theories (W = 0.368) and sustainable leadership perspectives (W = 0.362), respectively, have the highest priority among leadership theories and are crucial for establishing participatory decision-making among relevant stakeholders and applying adaptive strategies for wetlands governance under climate change conditions. The reconceptualization of leadership as a complex adaptive notion draws attention to the social complexities and emerging characteristics of leadership in contemporary societies and organizations. The understanding of leaders' and followers' networks and identifying the core role of leaders provides a foundation for developing leadership functions and theories beyond hierarchical, individualistic, and one-way concepts of leadership.

Veneer crowns in anterior endodontically-treated teeth: A case report with 1-year follow-up.

Key Clinical Message: Veneer crowns can be used in anterior endodontically-treated teeth with light occlusal force and enamel substrate consideration as a more conservative approach instead of conventional all ceramic crowns. Abstract: All-ceramic anterior crowns and veneers have been used widely in dentistry with high clinical success rate. The development of new reinforced ceramics in recent years has led to more use of extended defect-oriented preparation designs, that is, extended veneers, instead of full crown preparations which are less invasive. A veneer crown is simply a veneer that covers the entire tooth. The preparation preserves remaining enamel and uses a conservative preparation design. Its indication should be carefully raised taking into consideration various factors. The preparation design is crucial to ensure longevity of such restoration. The balance is between sufficient preparation for the material thickness and adequate strength against occlusal load and the enamel preservation. A 24-year-old man referred to the restorative department of the Dentistry School of Tehran University of Medical Sciences complaining from his poor esthetics in the maxillary incisors. In clinical and radiographic evaluation, he had open bite, composite discoloration due to corrosion of the pre-fabricated posts in all four incisors, a periapical lesion in tooth 21 and under-filled root canal therapy in tooth 22. All four posts and composite restorations were removed and teeth 21 and 22 were retreated. Although the amount of remaining tooth tissue was low, it had enough enamel thickness, especially in the buccal area. Taking into consideration this mixed enamel and dentin substrate, endodontics access, esthetics needs and canine guidance occlusion with no parafunction history, bonded lithium disilicate veneer crowns were selected to restore the maxillary incisors. A 12-month follow-up showed promising clinical (healthy gingival tissue and successful restorations) and radiographic (reduced periapical lesion) outcomes.

Effect of Laser and Conventional Office Bleaching and Polishing on the Color Change of Stained Nanohybrid and Microhybrid Composite Resin.

Aim: The present study investigated the effects of laser and conventional in-office bleaching, and polishing on the color of stained composite resin. Materials and Methods: A microhybrid composite (Clearfil AP-X) and a nanohybrid composite (Grandio) were selected. Twenty-four discs (2 × 10 mm) for each composite were prepared. The samples were immersed in coffee solution (25 g of coffee in 250 mL water) for seven days. Then the samples were divided into three groups (n = 8) and the stains were removed using bleaching (with Opalescence Xtra Boost), diode laser irradiation with Heydent material and a Sof-Lex polishing kit. The L ∗a ∗b ∗ color parameters were determined using a spectrophotometer before and after immersion and after stain removal procedures, and the overall color changes (ΔE) were calculated. The data were analyzed with two-way analysis of variance. Results: In the Clearfil composite resin group, the mean ΔE compared to the baseline using in-office bleaching, laser irradiation, and Sof-Lex polishing kit were 3.31, 3.35, and 4.93, respectively. These values with the Grandio composite resin were 3.31, 6.35, and 4.57, respectively. The highest capacity to remove stains was related to the conventional in-office bleaching method. Grandio composite resin underwent more color changes than Clearfil composite resin significantly (P-value < 0.05). Conclusion: Both composite resins exhibited color changes after immersion in the discoloring solution. However, after staining-removing procedures, the ΔE values decreased. Decreases in the ΔE values were not sufficient to restore the color to that before immersion in the discoloring solution with any stain-removing methods.

Effect of Wet and Dry Finishing and Polishing Technique on Microhardness and Flexural Strength of Nanocomposite Resins.

Objectives: This in vitro study was aimed to assess the effect of wet and dry finishing and polishing techniques on the flexural strength and microhardness of different commercial nanoparticle contained composite resins. Methods and Materials: The samples were made of Z250 (microhybrid), Z350 XT (nanofilled), and Z550 (nanohybrid) resin composites. Each group was subdivided into 2 subgroups according to polishing protocols. Subgroup 1 for each composite underwent wet polishing, and subgroup 2 was subject to dry polishing technique. Flexural strength and microhardness of the samples were measured at two different times of polishing (T 0 and T 24). The flexural strength test and microhardness test were measured by a 3-point bending test using a universal testing machine, and a Vickers machine, respectively. Data were analyzed by Kolmogorov-Smirnov, two-way ANOVA, and Tukey HSD tests. Results: ANOVA showed that the type of composite has a significant effect on flexural strength. Two-way ANOVA showed that, at T 0, flexural strength of all composites in the dry technique was higher than in the wet technique (p = 0.019). At T 24, Z350 XT had the lowest, and Z250 had the highest flexural strength in both techniques. The time and technique of polishing were also significantly effective on hardness. At T 0, hardness was higher in the wet compared to the dry method (p = 0.008). Tukey test showed that, at T 24, the hardness of Z350 XT was significantly higher than the other materials in both techniques. Conclusion: Immediate wet finishing and polishing presented lower flexural strength. Delayed dry/wet finishing and polishing significantly enhanced the hardness of the samples.

Dental care provision for people with neurodevelopmental disorders in Iran; a qualitative study of barriers.

INTRODUCTION: One of the most underserved populations among dental patients is the people with Neurodevelopmental Disorders (PNDs). This study aimed to explore the barriers to dental care provision for PNDs from the viewpoint of stakeholders in provision in Iran. METHODS: We arranged a qualitative study based on an individual in-depth, semi-structured interview between October 2019 and February 2020. We interviewed 30 participants using a snowball sampling strategy with three groups: dentists who provided dental care for PNDs, dental public health professionals, and policymakers/managers in dental care provision in Iran. The interviewer used an interview framework based on Levesque's model of patient-centered access. The main question was: "How do you assess the barriers to the provision of dental services to PNDs in Iran?" The data were analyzed by the qualitative content analysis method described by Graneheim and Lundman. RESULTS: From the 30 interviewees (11 women), there were 11 dentists, nine dental public health professionals, and 10 participants who worked as policymakers/managers. They were aged 35-62 years and had working experience between 4 and 25 years. In the content analysis, 60 meanings units were extracted, and later classified into 14 subthemes, and four main themes. CONCLUSION: Four main barriers were traced regarding access, financial, competency-related, and policy-making aspects.

Color match of high translucency monolithic zirconia restorations with different thicknesses and backgrounds.

OBJECTIVE: To assess the effects of ceramic thickness and background type on the color match of high translucency monolithic zirconia restorations. MATERIALS AND METHODS: Fifty A2 shade high translucency zirconia disk specimens with five different thicknesses (0.7, 0.9, 1.1, 1.4, 1.6 mm) were placed on 12 backgrounds: A1, A2, A3, A3.5, B1, and B2 shade composite resin, A3 shade zirconia, nonprecious gold-colored alloy, nickel-chromium alloy, amalgam, and A2 and A3 shade tooth. Color measurements were performed to determine the specimens' CIELab values. CIEDE2000 formula was used to determine ΔE00 color differences between specimens and A2 VITA classical shade (target). The ΔE00 values were compared with perceptibility (0.8) and acceptability (1.8) thresholds to assess color matches. Data were analyzed using repeated measures ANOVA, Bonferroni, and 1-sample t tests (P < .05). RESULTS: Mean ΔE00 values ranged between 1.3 and 5.7. Ceramic thickness, background type, and their interaction significantly affected the ΔE00 (P < .001). Ceramic thicknesses of ≥1.1 mm with the A2 or A3 shade tooth background showed 0.8 < ΔE00 ≤ 1.8 producing acceptable color matches. CONCLUSIONS: High translucency monolithic zirconia restorations with a minimum thickness of 1.1 mm on tooth backgrounds could create acceptable color matches; however, with other backgrounds tested, they could not. CLINICAL SIGNIFICANCE: Ceramic thickness and background type affect the color of high translucency monolithic zirconia restorations. A minimum zirconia thickness of 1.1 mm and normal color tooth structures, as a background, are essential for achieving the acceptable color match of these restorations.

Second generation analogues of the cancer drug clinical candidate tipifarnib for anti-Chagas disease drug discovery.

We previously reported that the cancer drug clinical candidate tipifarnib kills the causative agent of Chagas disease, Trypanosoma cruzi, by blocking ergosterol biosynthesis at the level of inhibition of lanosterol 14alpha-demethylase. Tipifarnib is an inhibitor of human protein farnesyltransferase. We synthesized tipifarnib analogues that no longer bind to protein farnesyltransferase and display increased potency for killing parasites. This was achieved in a structure-guided fashion by changing the substituents attached to the phenyl group at the 4-position of the quinoline ring of tipifarnib and by replacing the amino group by OMe. Several compounds that kill Trypanosoma cruzi at subnanomolar concentrations and are devoid of protein farnesyltransferase inhibition were discovered. The compounds are shown to be advantageous over other lanosterol 14alpha-demethylase inhibitors in that they show only modest potency for inhibition of human cytochrome P450 (3A4). Since tipifarnib displays high oral bioavailability and acceptable pharmacokinetic properties, the newly discovered tipifarnib analogues are ideal leads for the development of drugs to treat Chagas disease.

Structurally simple inhibitors of lanosterol 14alpha-demethylase are efficacious in a rodent model of acute Chagas disease.

We report structure-activity studies of a large number of dialkyl imidazoles as inhibitors of Trypanosoma cruzi lanosterol-14alpha-demethylase (L14DM). The compounds have a simple structure compared to posaconazole, another L14DM inhibitor that is an anti-Chagas drug candidate. Several compounds display potency for killing T. cruzi amastigotes in vitro with values of EC(50) in the 0.4-10 nM range. Two compounds were selected for efficacy studies in a mouse model of acute Chagas disease. At oral doses of 20-50 mg/kg given after establishment of parasite infection, the compounds reduced parasitemia in the blood to undetectable levels, and analysis of remaining parasites by PCR revealed a lack of parasites in the majority of animals. These dialkyl imidazoles are substantially less expensive to produce than posaconazole and are appropriate for further development toward an anti-Chagas disease clinical candidate.

Rational modification of a candidate cancer drug for use against Chagas disease.

Chagas disease is one of the major neglected diseases of the world. Existing drug therapies are limited, ineffective, and highly toxic. We describe a novel strategy of drug discovery of adapting an existing clinical compound with excellent pharmaceutical properties to target a pathogenic organism. The protein farnesyltransferase (PFT) inhibitor tipifarnib, now in phase III anticancer clinical trials, was previously found to kill Trypanosoma cruzi by blocking sterol 14 alpha-demethylase (14DM). We rationally developed tipifarnib analogues that display reduced affinity for human PFT to reduce toxicity while increasing affinity for parasite 14DM. The lead compound has picomolar activity against cultured T. cruzi and is efficacious in a mouse model of acute Chagas disease.