The Schwinger Variational Method

Variational methods have proven invaluable in theoretical physics and chemistry, both for bound state problems and for the study of collision phenomena. For collisional problems they can be grouped into two types: those based on the Schroedinger equation and those based on the Lippmann-Schwinger equation. The application of the Schwinger variational (SV) method to e-molecule collisions and photoionization has been reviewed previously. The present chapter discusses the implementation of the SV method as applied to e-molecule collisions

Pancreatic islet autotransplantation with total pancreatectomy for chronic pancreatitis

Achieving pain relief and improving the quality of life are the main targets of treatment for patients with chronic pancreatitis. The use of total pancreatectomy to treat chronic pancreatitis is a radical and in some ways ideal strategy. However, total pancreatectomy is associated with severe diabetic control problems. Total pancreatectomy with islet autotransplantation can relieve severe pain and prevent the development of postsurgical diabetes. With islet autotransplantation, patients with chronic pancreatitis receive their own islet cells and therefore do not require immunosuppressive therapy. In the future, total pancreatectomy with islet autotransplantation may be considered a treatment option for chronic pancreatitis patients

CpG-creating mutations are costly in many human viruses

Mutations can occur throughout the virus genome and may be beneficial, neutral or deleterious. We are interested in mutations that yield a C next to a G, producing CpG sites. CpG sites are rare in eukaryotic and viral genomes. For the eukaryotes, it is thought that CpG sites are rare because they are prone to mutation when methylated. In viruses, we know less about why CpG sites are rare. A previous study in HIV suggested that CpG-creating transition mutations are more costly than similar non-CpG-creating mutations. To determine if this is the case in other viruses, we analyzed the allele frequencies of CpG-creating and non-CpG-creating mutations across various strains, subtypes, and genes of viruses using existing data obtained from Genbank, HIV Databases, and Virus Pathogen Resource. Our results suggest that CpG sites are indeed costly for most viruses. By understanding the cost of CpG sites, we can obtain further insights into the evolution and adaptation of viruses

Características morfofuncionais do trânsito orofaríngeo na bulimia: revisão de literatura Morphofunctional characteristics of the oropharyngeal tract in bulimia: review of literature

TEMA: deglutição e bulimia. OBJETIVO: apresentar e discutir os achados científicos descritos na literatura quanto às características orofaríngeas relacionadas à deglutição em portadores de bulimia nervosa do tipo purgativa. CONCLUSÃO: a bulimia nervosa acarreta uma série de alterações em estruturas e funções que compõem o trânsito orofaríngeo, como erosão dentária, hipersensibilidade, enfraquecimento e fratura dos dentes, problemas de oclusão, cáries, doenças periodontais, dessensibilização intra-oral, hipogeusia, úlceras, granulomas, queilite angular, hipertrofia das glândulas parótidas, tosse e odinofagia. Existe um predomínio na literatura científica de relatos sobre alterações morfológicas em detrimento das funcionais. Poucos relatos abordaram diretamente a relação entre a bulimia e deglutição, apenas mencionando superficialmente as possibilidades de desencadeamento da disfagia orofaríngea.<br>BACKGROUND: deglutition and bulimia. PURPOSE: to submit and discuss the scientific research concerning oropharyngeal characteristics related to deglutition in patients with purging type bulimia nervosa. CONCLUSIONS: bulimia nervosa entails a series of changes in structures and functions that compose the oropharyngeal tract, such as dental erosion, hypersensitivity, weakness and fracture of the teeth, occlusion problems, caries, periodontal diseases, intraoral desensitization, hypogeusia, ulceration, granulomas, angular cheilitis, enlargement of the parotid glands, coughs and odynophagia. There is a prevalence in the scientific literature of reports about morphologic alterations on the detriment of the functional ones. Few reports discussed the relationship between bulimia and deglutition, superficially mentioning the possibilities for triggering oropharyngeal dysphagia