Optimisation of Cu+ impregnation of MOF-74 to improve CO/N2 and CO/CO2 separations

Carbon monoxide (CO) purification from syngas impurities is a highly energy and cost intensive process. Adsorption separation using metal–organic frameworks (MOFs) is being explored as an alternative technology for CO/nitrogen (N₂) and CO/carbon dioxide (CO₂) separation. Currently, MOFs'' uptake and selectivity levels do not justify displacement of the current commercially available technologies. Herein, we have impregnated a leading MOF candidate for CO purification, i.e. M-MOF-74 (M = Co or Ni), with Cu⁺ sites. Cu⁺ allows strong π-complexation from the 3d electrons with CO, potentially enhancing the separation performance. We have optimised the Cu loading procedure and confirmed the presence of the Cu⁺ sites using X-ray absorption fine structure analysis (XAFS). In situ XAFS and diffuse reflectance infrared Fourier Transform spectroscopy analyses have demonstrated Cu⁺–CO binding. The dynamic breakthrough measurements showed an improvement in CO/N₂ and CO/CO₂ separations upon Cu impregnation. This is because Cu sites do not block the MOF metal sites but rather increase the number of sites available for interactions with CO, and decrease the surface area/porosity available for adsorption of the lighter component.

We present an in situ study of CO adsorption on Cu impregnated MOF-74 and study the competitive adsorption of CO vs. CO₂ and N₂.     

Molecular fragile X screening in normal populations

In December, 1993, we initiated a pilot project in which DNA fragile X (fraX) testing was offered during routine prenatal or genetic counseling to all pregnant women seen at the Genetics & IVF Institute, most of whom were referred for the indication of advanced maternal age. A brochure on fragile X syndrome was sent to each patient prior to her appointment and was reviewed by a counselor or physician during the counseling session. As of June 1995, 3,345 patients were offered testing; 474 women with no identified family history of mental retardation or learning disability and 214 women with a positive family history accepted the test on a self-pay basis. The second population screened was 271 potential donors in our anonymous egg donor program. DNA from blood was tested by Southern blot using EcoRI/EagI and StB12.3. If an expansion was detected, CGG repeat number was determined by PCR-based analysis. Among the 474 patients with unremarkable family histories, three fraX carriers were identified (repeat sizes = 60+), whereas none were found in the 214 patients with a positive family history. Among the potential egg donors, two high borderline patients were identified (repeat sizes = between 50 and 59). Our ongoing study indicates that screening of pregnant or preconceptual populations for fraX carrier status using DNA testing is accepted by many patients and is an important addition to current medical practice. © 1996 Wiley-Liss, Inc.     

Cephalic phase insulin release in bulimia

Cephalic phase secretions are associated with the sight, smell, and taste of food, as opposed to its postingestional consequences. These secretions are thought to influence metabolism and eating behavior. Cephalic phase insulin release (CPIR), in particular, might be related to hunger and overeating. It was hypothesized that bulimics, who often show endocrine abnormalities, may have an altered CPIR that, in turn, might be related to the precipitation and maintenance of binges. This study investigated whether (1) the profile or magnitude of the CPIR in bulimics differs from that of non-eating disordered controls, (2) food ingestion alters subsequent CPIR, and (3) mood and desire to binge are related to CPIR. Findings indicated little abnormality in bulimics' profile of insulin secretion. Although biological variables were not related to hunger or desire to binge, for bulimics, dysphoric moods were. The results may suggest more complex determinants of binge eating than physiological state alone. © 1993 by John Wiley & Sons, Inc.     

Comparing once-weekly semaglutide to incretin-based therapies in patients with type 2 diabetes: a systematic review and meta-analysis

Aims

Our aim was to compare once-weekly semaglutide to incretin-based therapies – defined as either dipeptidyl peptidase-4 inhibitors (DPP-4i) or other glucagon-like peptide-1 receptor agonist (GLP-1RA) – in patients with type 2 diabetes.

A high-efficiency Cre/loxP-based system for construction of adenoviral vectors

Adenovirus (Ad) vectors provide a highly efficient means of mammalian gene transfer and are widely used for high-level protein expression in mammalian cells, as recombinant vaccines and for gene therapy. A commonly used method for constructing Ad vectors relies on in vivo homologous recombination between two Ad DNA-containing bacterial plasmids cotransfected into 293 cells. While the utility of this two-plasmid approach is well established, its efficiency is low owing to the inefficiency of homologous recombination. To address this, we have developed an improved method for Ad vector construction based on Cre-mediated site-specific recombination between two bacterial plasmids, each bearing a loxP site. Ad vectors are generated as a result of Cre-mediated site-specific recombination between the two plasmids after their cotransfection into 293 cells expressing Cre recombinase. The frequency of Ad vector rescue by Cre-mediated site-specific recombination is significantly higher (approximately 30-fold) than by in vivo homologous recombination. The efficiency and reliability of this method should greatly simplify and expedite the construction of recombinant Ad vectors for mammalian gene transfer. Ad vectors are commonly constructed by homologous recombination between two plasmids cotransfected into 293 cells. This method has numerous advantages but results in low numbers of plaques owing to inefficient recombination. We have developed an improved method based on Cre-mediated site-specific recombination, which results in vector rescue at frequencies approximately 30-fold higher than by homologous recombination. This method should greatly simplify and expedite the construction of recombinant Ad vectors for mammalian gene transfer.     

CHALLENGING BEHAVIOUR AND COMMUNITY SERVICES: 5. Structuring staff and client activity

This paper describes important programmatic components of small, community based, residential services for people with severe mental handicaps and challenging behaviours. The approach described advocates the use of procedures to plan staff activity in considerable detail in order to achieve goals in the areas of supporting people's engagement in functional, age-appropriate activities and managing inappropriate behaviour.     

Discordant expression of selectin ligands and sialyl Lewis x-related epitopes on murine myeloid cells

Murine leukocytes are thought to express alpha2-3-sialylated and alpha1-3-fucosylated selectin ligands such as sialyl Lewis x (sLe(x)), although monoclonal antibodies (mAbs) to sLe(x) or Le(x) reportedly do not bind to murine leukocytes. We observed that P- and E-selectin bound to pronase-sensitive ligands on murine monocytic WEHI-3 cells and murine neutrophils, indicating that the ligands for both selectins are glycoproteins. CSLEX-1, HECA-452, and other widely used mAbs to sLe(x) and Le(x) did not bind to WEHI-3 cells and bound at very low levels to murine neutrophils. Only the anti-sLe(x) mAbs 2H5 and KM93, which also recognize nonfucosylated glycans, bound to WEHI-3 cells. 2H5 and KM93 bound to pronase-resistant structures, indicating that the mAbs did not identify selectin ligands. Treatment of WEHI-3 cells with glycosidases or chlorate demonstrated that sialic acid modifications, alpha1-3-galactosylation, or sulfation did not mask epitopes for mAbs to sLe(x) or Le(x). Compared to human promyelocytic HL-60 cells, WEHI-3 cells and murine neutrophils expressed low alpha1-3-fucosyltransferase activities. Consistent with very low endogenous fucosylation, forced fucosylation of intact WEHI-3 cells or murine neutrophils by exogenous alpha1-3-fucosyltransferase FTVI and GDP-fucose created many new epitopes for anti-sLe(x) mAbs such as HECA-452 and CSLEX-1. Nevertheless, forced fucosylation of intact cells did not significantly augment their ability to bind to fluid-phase P- or E-selectin or to roll on immobilized P- or E-selectin under flow. These data suggest that murine myeloid leukocytes fucosylate only a few specific glycans, which interact preferentially with P- and E-selectin.     

The economic cost of Alzheimer's disease and related dementias to the California Medicaid program ("Medi-Cal") in 1995.

Although state Medicaid programs may bear a large portion of the costs of Alzheimer's disease (AD), current information on spending is not available. Using a health insurance claims database for a 10% random sample of California Medicaid ("Medi-Cal") recipients 60+ years of age, the authors estimated the excess cost of AD to Medi-Cal in 1995 as the difference in expenditures between an AD cohort (those with AD or related dementias) and an age- and sex-matched cohort without AD. Among 62,450 recipients, 2,575 (4.1%) were found to have AD or related dementias, and their average payments were approximately $7,700 higher (P<0.01) than those for the comparison group. These estimates suggest that Medi-Cal spends about $200 million on AD and related dementias annually, a burden that represents nearly 10% of state spending on elderly patients.