A Study on Auto-Catalysis and Product Inhibition: A Nucleophilic Aromatic Substitution Reaction Catalysed within the Cavity of an Octanuclear Coordination Cage.

The ability of an octanuclear cubic coordination cage to catalyse a nucleophilic aromatic substitution reaction on a cavity-bound guest was studied with 2,4-dinitrofluorobenzene (DNFB) as the guest/substrate. It was found that DNFB undergoes a catalysed reaction with hydroxide ions within the cavity of the cubic cage (in aqueous buffer solution, pH 8.6).

Studying manganese carbonyl photochemistry in a permanently porous metal-organic framework.

Mn(diimine)(CO)X (X = halide) complexes are critical components of chromophores, photo- and electrocatalysts, and photoactive CO-releasing molecules (photoCORMs). While these entities have been incorporated into metal-organic frameworks (MOFs), a detailed understanding of the photochemical and chemical processes that occur in a permanently porous support is lacking. Here we site-isolate and study the photochemistry of a Mn(diimine)(CO)Br moiety anchored within a permanently porous MOF support, allowing for not only the photo-liberation of CO from the metal but also its escape from the MOF crystals.

MOF matrix isolation: cooperative conformational mobility enables reliable single crystal transformations.

Obtaining structural information for highly reactive metal-based species can provide valuable insight into important chemical transformations or catalytic processes. Trapping these metal-based species within the cavities of porous crystalline hosts, such as metal-organic frameworks (MOFs), can stabilise them, allowing detailed structural elucidation by single crystal X-ray diffraction. Previously, we have used a bespoke flexible MOF, [Mn3L2L'] (MnMOF-1, where L = bis-(4-carboxyphenyl-3,5-dimethylpyrazolyl)methane and L = L', but L' has a vacant N,N'-chelation site), which has a chelating site capable of post-synthetically binding metal ions, to study organometallic transformations and fundamental isomerisation processes.

Isolating reactive metal-based species in Metal-Organic Frameworks - viable strategies and opportunities.

Structural insight into reactive species can be achieved strategies such as matrix isolation in frozen glasses, whereby species are kinetically trapped, or by confinement within the cavities of host molecules. More recently, Metal-Organic Frameworks (MOFs) have been used as molecular scaffolds to isolate reactive metal-based species within their ordered pore networks. These studies have uncovered new reactivity, allowed observation of novel metal-based complexes and clusters, and elucidated the nature of metal-centred reactions responsible for catalysis.

Characterisation of two self-sufficient CYP102 family monooxygenases from Ktedonobacter racemifer DSM44963 which have new fatty acid alcohol product profiles.

Background: Two self-sufficient CYP102 family encoding genes (Krac_0936 and Krac_9955) from the bacterium Ktedonobacter racemifer DSM44963, which possesses one of the largest bacterial genomes, have been identified.

Methods: Phylogenetic analysis of both the encoded cytochrome P450 enzymes, Krac0936 and Krac9955. Both enzymes were produced and their turnovers with fatty acid substrates assessed in vitro and using a whole-cell oxidation system.

A retrospective, case-control pilot study of the natural history of pediatric gastroesophageal reflux.

The duration of gastroesophageal reflux disease (GERD) is an important factor in the development of esophageal complications. The objective of this study was to examine in a retrospective, case-controlled manner the prevalence of GERD in adults who were diagnosed with GERD in infancy or early childhood. Infants and children with nonsyndromic GERD diagnosed by an experienced pediatric gastroenterologist from 1976 to 1980 and control subjects seen for well-child care from 1980 to 1985 were included in this study.

Diagnosis and management of gastrointestinal polyps: pediatric considerations.

Painless, bright red, rectal bleeding with normal stool frequency and consistency is the hallmark presentation of colorectal polyps at any age. Most polyps in children are sporadic, usually isolated, colorectal juvenile polyps that do not require any further surveillance after they are removed. There is, however, increasing recognition of syndromes, including familial adenomatous polyposis, juvenile polyposis coli, Peutz-Jeghers syndrome, and infrequent conditions, such as PTEN hamartoma and hereditary mixed polyposis syndromes.

Enteric microbial flora, bacterial overgrowth, and short-bowel syndrome.

Small intestinal bacterial overgrowth (SIBO) occurs commonly in short-bowel syndrome (SBS) and, in some instances, may result in significant problems. SIBO is characterized by a variety of signs and symptoms resulting from nutrient malabsorption caused by an increased number and/or type of bacteria in the small intestine. The anatomic and physiologic changes that occur in SBS together with medications commonly used in these patients facilitate the development of SIBO.

Overview of considerations for the pediatric patient receiving home parenteral and enteral nutrition.

Pediatric home nutrition support is a common practice used to provide children with impaired gastrointestinal function and their caregivers a therapeutic environment for the delivery of needed nutrition for proper growth and development. Specialized teams and equipment are now available to make this a successful experience for all involved. This paper will review items specific to the care of infants and children receiving both enteral and parenteral nutrition.

Neonatal and infant feeding: effect on bone density at 4 years.

Objective: The aim of this study was to determine whether the type of feeding during the first 4 months of life affects bone mineral density at 4 years of age.

Methods: Healthy 4-year-old children were recruited from the offices of primary health care providers. After confirming the type of infant feeding by history, dual energy x-ray absorptiometry analysis was obtained at the University of Nebraska Medical Center and evaluated by a radiologist blinded as to feeding type.

Current and potential uses of probiotics.

Objective: To present data that support the current and potential use of probiotics in treating or preventing allergic disorders of the gastrointestinal tract and other disorders.

Data Sources: Case reports, double-blind studies, and animal studies were reviewed.

Study Selection: Studies were selected based on the expert opinion of the authors.

Intestinal rehabilitation and the short bowel syndrome: part 2.

The management of patients with intestinal failure due to short bowel syndrome is complex, requiring a comprehensive approach that frequently necessitates long-term, if not life-long, use of parenteral nutrition. Despite tremendous advances in the provision of parenteral nutrition over the past three decades, which have allowed significant improvements in the survival and quality of life of these patients, this mode of nutritional support carries with it significant risks to the patient, is very costly, and ultimately, does not attempt to improve the function of the remaining bowel. Intestinal rehabilitation refers to the process of restoring enteral autonomy, and thus, allowing freedom from parenteral nutrition, usually by means of dietary, medical, and occasionally, surgical strategies.

Intestinal rehabilitation and the short bowel syndrome: part 1.

The management of patients with intestinal failure due to short bowel syndrome (SBS) is complex, requiring a comprehensive approach that frequently necessitates long-term, if not life-long, use of parenteral nutrition (PN). Despite tremendous advances in the provision of PN over the past three decades, which have allowed significant improvements in the survival and quality of life of these patients, this mode of nutritional support carries with it significant risks to the patient, is very costly and, ultimately, does not attempt to improve the function of the remaining bowel. Intestinal rehabilitation refers to the process of restoring enteral autonomy and, thus, allowing freedom from parenteral nutrition, usually by means of dietary, medical, and, occasionally, surgical strategies.

Enteral and parenteral nutrition in the care of patients with short-bowel syndrome.

Short-bowel syndrome is a challenging entity for the gastroenterologist, requiring integration of medical, nutritional, surgical and psychological therapies. Treatment must be based on the patient's age, remaining gastrointestinal anatomy, baseline nutritional status and underlying general health as well as the numerous complications which may arise. This chapter reviews physiological alterations that occur with short-bowel syndrome and how therapies can be tailored to most adequately meet the needs of these patients.

Probiotic use in children.

Interest in nutritional supplements and functional foods has risen significantly in recent years. Many of the products that are marketed to consumers tout the benefits of probiotics for general good health and for a wide variety of conditions and situations. Although most of these products have been used safely for years, careful analysis of scientific research should be conducted before routinely recommending these products, especially for children.

New and emerging therapies for short bowel syndrome in children.

This review provides an overview of traditional as well as emerging therapies useful in the management of pediatric short bowel syndrome. Pediatric short bowel syndrome is relatively uncommon; however, when it does occur, it presents a unique challenge to medical care providers. The use of parenteral and enteral nutrition to maximize growth and enhance intestinal adaptation so as to increase absorptive surface area has been the primary focus of therapy.

Role of probiotics in the management of patients with food allergy.

Objective: This review will concentrate on the potential use of probiotics in treating or preventing allergic disorders of the gastro-intestinal tract. In small infants, most reactions to foods are manifested in the gastro-intestinal tract. As children get older, cutaneous and even systemic or respiratory manifestations of food intolerances may be more common.