956 resultados para GEOSCIENCES, MULTIDISCIPLINARY
Resumo:
Polyvinylpyrollidone (PVP)-capped platinum nanoparticles (NPs) are found to change shape from spherical to flat when deposited on mesoporous silica substrates (SBA-15). Transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), and extended X-ray absorption fine structure (EXAFS) analyses are used in these studies. The SAXS results indicate that, after deposition, the 2 nm NPs have an average gyration radius 22% larger than in solution, while the EXAFS measurements indicate a decrease in first neighbor co-ordination number from 9.3 to 7.4. The deformation of these small capped NPs is attributed to interactions with the surface of the SBA-15 support, as evidenced by X-ray absorption near-edge structure (XANES).
Resumo:
The decision-making process for the treatment of esthetic areas is based on the achievement of a healthy, harmonious, and pleasant smile. These conditions are directly associated with a solid knowledge of tooth anatomy and proportions, as well as the smile line, soft tissue morphology, and osseous architecture. To achieve these objectives, a multidisciplinary approach may be necessary to create long-term harmony between the final restoration and the adjacent teeth, and the health of the surrounding soft and hard tissues. This case report describes the application of a minimally invasive therapy on a 33-year-old woman seeking esthetic treatment. Minimally invasive periodontal plastic surgery associated with porcelain laminate veneers yielded satisfactory esthetics and minimal trauma to dental and periodontal tissues. Such a combined approach may be considered a viable option for the improvement of "white" and "red" esthetics.
Resumo:
Many potential diltiazem related L-VDCC blockers were developed using a multidisciplinary approach. This current study was to investigate and compare diltiazem with to the newly developed compounds by mouse Langendorff-perfused heart, Ca2+-transient and on recombinant L-VDCC. Twenty particular compounds were selected by the ligand-based virtual screening procedure (LBVS). From these compounds, five of them (5b, M2, M7, M8 and P1) showed a potent and selective inotropic activity on guinea-pig left atria driven 1 Hz. Further assays displayed an interesting negative inotropic effect of M2, M8, P1 and M7 on guinea pig isolated left papillary muscle driven at 1 Hz, a relevant vasorelaxant activity of 5b, M2, M7, M8 and P1 on K+-depolarized guinea-pig ileum longitudinal smooth muscle and a significant inhibition of contraction of 5b, M2, M8 and P1 on carbachol stimulated ileum longitudinal smooth muscle. Wild-type human heart and rabbit lung α1 subunits were expressed (combined with the regulatory α2δ and β3 subunits) in Xenopus Leavis oocytes using a two-electrode voltage clamp technique. Diltiazem is a benzothiazepine Ca2+ channel blocker used clinically for its antihypertensive and antiarrhythmic effects. Previous radioligand binding assays revealed a complex interaction with the benzothiazepine binding site for M2, M7 and M8. (Carosati E. et al. J. Med Chem. 2006, 49; 5206). In agreement with this findings, the relative order of increased rates of contraction and relaxation at lower concentrations s(≤10-6M) in unpaced hearts was M7>M2>M8>P1. Similar increases in Ca2+ transient were observed in cardiomyocytes. Diltiazem showed negative inotropic effects whereas 5b had no significant effect. Diltiazem blocks Ca2+current in a use-dependent manner and facilitates the channel by accelerating the inactivation and decelerating the recovery from inactivation. In contrast to diltiazem, the new analogs had no pronounced use-dependence. Application of 100 μM M8, M2 showed ~ 10% tonic block; in addition, M8, M2 and P1 shifted the steady state inactivation in hyperpolarized direction and the current inactivation time was significantly decreased compared with control (219.6 ± 11.5 ms, 226 ± 14.5 vs. 269 ± 12.9 vs. 199.28 ± 8.19 ms). Contrary to diltiazem, the recovery from the block by M8 and M2 was comparable to control. Only P1 showed a significantly decrease of the time for the recovery from inactivation. All of the compounds displayed the same sensitivity on the Ca2+ channel rabbit lung α1 except P1. Taken together, these findings suggest that M8, M2 and P1 might directly decrease the binding affinity or allow rapid dissociation from the benzothiazepine binding site.
Resumo:
It is well known that ageing and cancer have common origins due to internal and environmental stress and share some common hallmarks such as genomic instability, epigenetic alteration, aberrant telomeres, inflammation and immune injury. Moreover, ageing is involved in a number of events responsible for carcinogenesis and cancer development at the molecular, cellular, and tissue levels. Ageing could represent a “blockbuster” market because the target patient group includes potentially every person; at the same time, oncology has become the largest therapeutic area in the pharmaceutical industry in terms of the number of projects, clinical trials and research and development (R&D) spending, but cancer remains one of the leading causes of mortality worldwide. The overall aim of the work presented in this thesis was the rational design of new compounds able to modulate activity of relevant targets involved in cancer and aging-related pathologies, namely proteasome and immunoproteasome, sirtuins and interleukin 6. These three targets play different roles in human cells, but the modulation of its activity using small molecules could have beneficial effects on one or more aging-related diseases and cancer. We identified new moderately active and selective non-peptidic compounds able to inhibit the activity of both standard and immunoproteasome, as well as novel and selective scaffolds that would bind and inhibit SIRT6 selectively and can be used to sensitize tumor cells to commonly used anticancer agents such gemcitabine and olaparib. Moreover, our virtual screening approach led us also to the discovery of new putative modulators of SIRT3 with interesting in-vitro and cellular activity. Although the selectivity and potency of the identified chemical scaffolds are susceptible to be further improved, these compounds can be considered as highly promising leads for the development of future therapeutics.
Resumo:
The treatment of amelogenesis imperfecta (AI) with an anterior open bite (AOB) is a challenge for the clinician and often requires a multidisciplinary team of specialists. Most often, patients suffering from these conditions are young and a good functional and esthetic long-term result must be aspired. This clinical report illustrates the orthodontic, maxillofacial, restorative, and prosthodontic rehabilitation of a 20-year-old woman with a hypoplastic form of AI and an AOB malocclusion, having received treatment for the last 6 years. It included adhesive resin composite restorations, orthodontical and maxillofacial surgery with a one-piece Le Fort I osteotomy, and a genioplasty. Subsequent prosthodontic therapy consisted of 28 all-ceramic crowns whereby a solid interdigitation, a canine guidance, and consistent and regular contacts between tooth crowns could be achieved to assure a good functional and esthetic oral situation. The tooth preparation techniques guaranteed minimally invasive treatment. The patient was affected very positively. CLINICAL SIGNIFICANCE: This article describes an interdisciplinary approach to the successful treatment of a patient with a hypoplastic form of amelogenesis imperfecta over a period of 6 years. It starts with a discussion of the conservative steps taken during adolescence and concludes with the final prosthetic rehabilitation with all-ceramic crowns after reaching adulthood.
Resumo:
Courses in the Advanced Trauma Life Support are a well-accepted concept throughout the world for training in the emergency treatment of polytraumatized patients. Switzerland, a multilingual country with a long tradition of multidisciplinary collaboration in trauma care, introduced its first student courses in 1998. Unlike some countries where the courses are attended only by surgeons, instructors and students in Switzerland include surgeons, anaesthetists and physicians from other specialties.
Resumo:
INTRODUCTION: It has been shown that early central venous oxygen saturation (ScvO2)-guided optimization of hemodynamics can improve outcome in septic patients. The early ScvO2 profile of other patient groups is unknown. The aim of this study was to characterize unplanned admissions in a multidisciplinary intensive care unit (ICU) with respect to ScvO2 and outcome. METHODS: Ninety-eight consecutive unplanned admissions to a multidisciplinary ICU (median age 63 [range 19 to 83] years, median Simplified Acute Physiology Score [SAPS II] 43 [range 11 to 92]) with a clinical indication for a central venous catheter were included in the study. ScvO2 was assessed at ICU arrival and six hours later but was not used to guide treatment. Length of stay in ICU (LOSICU) and in hospital (LOShospital) and 28-day mortality were recorded. RESULTS: ScvO2 was 70% +/- 12% (mean +/- standard deviation) at admission and 71% +/- 10% six hours later (p = 0.484). Overall 28-day mortality was 18%, LOSICU was 3 (1 to 28) days, and LOShospital was 19 (1 to 28) days. Patients with an ScvO2 of less than 60% at admission had higher mortality than patients with an ScvO2 of more than 60% (29% versus 17%, p < 0.05). Changes in ScvO2 during the first six hours were not predictive of LOSICU, LOShospital, or mortality. CONCLUSION: Low ScvO2 in unplanned admissions and high SAPS II are associated with increased mortality. Standard ICU treatment increased ScvO2 in patients with a low admission ScvO2, but the increase was not associated with LOSICU or LOShospital.