A route to high surface area, porosity and inclusion of large molecules in crystals

One of the outstanding challenges in the field of porous materials is the design and synthesis of chemical structures with exceptionally high surface areas(1). Such materials are of critical importance to many applications involving catalysis, separation and gas storage. The claim for the highest surface area of a disordered structure is for carbon, at 2,030 m(2) g(-1) (ref. 2). Until recently, the largest surface area of an ordered structure was that of zeolite Y, recorded at 904 m(2) g(-1) (ref. 3). But with the introduction of metal-organic framework materials, this has been exceeded, with values up to 3,000 m(2) g(-1) (refs 4-7). Despite this, no method of determining the upper limit in surface area for a material has yet been found. Here we present a general strategy that has allowed us to realize a structure having by far the highest surface area reported to date. We report the design, synthesis and properties of crystalline Zn4O(1,3,5-benzenetribenzoate)(2), a new metal-organic framework with a surface area estimated at 4,500 m(2) g(-1). This framework, which we name MOF-177, combines this exceptional level of surface area with an ordered structure that has extra-large pores capable of binding polycyclic organic guest molecules-attributes not previously combined in one material.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62609/1/nature02311.pd

Dependent and problem drinking over 5 years: a latent class growth analysis

Understanding the long-term course of problematic drinking is a fundamental concern for health services research in the alcohol field. The stability of, or change in, the course of drinking-especially heavy drinking-has both theoretical and applied relevance to alcohol research. We explore the application of latent class growth modeling to 5 years of survey data collected from dependent and problem drinkers-some not in treatment at baseline-in an attempt to uncover prototypical longitudinal drinking patterns. Results indicated that five profiles of drinkers can be used to represent their longitudinal course of alcohol consumption: early quitters (N = 88), light/non-drinkers (N = 76), gradual improvers (N = 129), moderate drinkers (N = 229), and heavy drinkers (N = 572). Significant baseline factors included ASI drug severity, dependence symptoms, and marital status. Attendance at AA meetings, the size of one's heavy drinking and drug using social network, past treatment, receiving suggestions about one's drinking, and contacts with the medical system were significant influences. The size of heavy drinking and drug using social networks was noticeably larger for the heavy drinkers. Findings also support the usefulness of a semi-parametric latent group-based approach as a tool for analyzing alcohol-related behaviors. (C) 2004 Elsevier Ireland Ltd. All rights reserved

MOFâ 5â Polystyrene: Direct Production from Monomer, Improved Hydrolytic Stability, and Unique Guest Adsorption

An unprecedented mode of reactivity of Zn4Oâ based metalâ organic frameworks (MOFs) offers a straightforward and powerful approach to polymerâ hybridized porous solids. The concept is illustrated with the production of MOFâ 5â polystyrene wherein polystyrene is grafted and uniformly distributed throughout MOFâ 5 crystals after heating in pure styrene for 4â 24â h. The surface area and polystyrene content of the material can be fineâ tuned by controlling the duration of heating styrene in the presence of MOFâ 5. Polystyrene grafting significantly alters the physical and chemical properties of pristine MOFâ 5, which is evident from the unique guest adsorption properties (solvatochromic dye uptake and improved CO2 capacity) as well as the dramatically improved hydrolytic stability of composite. Based on the fact that MOFâ 5 is the best studied member of the structure class, and has been produced at scale by industry, these findings can be directly leveraged for a range of current applications.MOFs packed with polystyrene: An unprecedented mode of reactivity of one of the best studied metalâ organic frameworks, MOFâ 5, offers a powerful approach to polymerâ hybridized porous solids. A MOFâ 5â polystyrene (MOFâ 5â PS) composite was directly produced from the monomer styrene. In the MOFâ 5â PS composites, polystyrene is grafted and uniformly distributed throughout, which leads to enhanced hydrolytic stability and unique guest adsorption.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134282/1/anie201606926_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134282/2/anie201606926-sup-0001-misc_information.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134282/3/anie201606926.pd

MOFâ 5â Polystyrene: Direct Production from Monomer, Improved Hydrolytic Stability, and Unique Guest Adsorption

An unprecedented mode of reactivity of Zn4Oâ based metalâ organic frameworks (MOFs) offers a straightforward and powerful approach to polymerâ hybridized porous solids. The concept is illustrated with the production of MOFâ 5â polystyrene wherein polystyrene is grafted and uniformly distributed throughout MOFâ 5 crystals after heating in pure styrene for 4â 24â h. The surface area and polystyrene content of the material can be fineâ tuned by controlling the duration of heating styrene in the presence of MOFâ 5. Polystyrene grafting significantly alters the physical and chemical properties of pristine MOFâ 5, which is evident from the unique guest adsorption properties (solvatochromic dye uptake and improved CO2 capacity) as well as the dramatically improved hydrolytic stability of composite. Based on the fact that MOFâ 5 is the best studied member of the structure class, and has been produced at scale by industry, these findings can be directly leveraged for a range of current applications.Mit Polystyrol gepackte MOFs: Eine bisher unbekannte Reaktivität eines der am besten untersuchten Metallâ organischen Gerüstmaterialien, MOFâ 5, bietet Zugang zu polymerhybridisierten porösen Festkörpern. Ein MOFâ 5â Polystyrol(MOFâ 5â PS)â Komposit wurde direkt aus dem Monomer Styrol hergestellt. Das Polystyrol ist im MOFâ 5â PSâ Gerüst einheitlich verteilt und bewirkt eine erhöhte Hydrolysestabilität.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134159/1/ange201606926.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134159/2/ange201606926-sup-0001-misc_information.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134159/3/ange201606926_am.pd

Combinatorial approaches to the synthesis of vapor detector arrays for use in an electronic nose

The technology of “electronic noses”, i.e., devices that functionally mimic the sense of olfaction, is rapidly evolving, driven by the practical demand for objective analysis of odors as well as by the intellectual challenge of mimicking th

Accelerating typhoid conjugate vaccine introduction: what can be learned from prior new vaccine introduction initiatives?

The health consequences of typhoid, including increasing prevalence of drug-resistant strains, can stress healthcare systems. While vaccination is one of the most successful and cost-effective health interventions, vaccine introduction can take years and require considerable effort. The Typhoid Vaccine Acceleration Consortium (TyVAC) employs an integrated, proactive approach to accelerate the introduction of a new typhoid conjugate vaccine to reduce the burden of typhoid in countries eligible for support from Gavi, the Vaccine Alliance. TyVAC and its partners are executing a plan, informed by prior successful vaccine introductions, and tailored to the nuances of typhoid disease and the typhoid conjugate vaccine. The iterative process detailed herein summarizes the strategy and experience gained from the first 2 years of the project

Reduction of Thrombosis and Bacterial Infection via Controlled Nitric Oxide (NO) Release from S‑Nitroso‑N‑acetylpenicillamine (SNAP) Impregnated CarboSil Intravascular Catheters

Nitric oxide (NO) has many important physiological functions, including its ability to inhibit platelet activation and serve as potent antimicrobial agent. The multiple roles of NO in vivo have led to great interest in the development of biomaterials that can deliver NO for specific biomedical applications. Herein, we report a simple solvent impregnation technique to incorporate a nontoxic NO donor, S-nitroso-N-acetylpenicillamine (SNAP), into a more biocompatible biomedical grade polymer, CarboSil 20 80A. The resulting polymer-crystal composite material yields a very stable, long-term NO release biomaterial. The SNAP impregnation process is carefully characterized and optimized, and it is shown that SNAP crystal formation occurs in the bulk of the polymer after solvent evaporation. LC-MS results demonstrate that more than 70% of NO release from this new composite material originates from the SNAP embedded CarboSil phase, and not from the SNAP species leaching out into the soaking solution. Catheters prepared with CarboSil and then impregnated with 15 wt % SNAP provide a controlled NO release over a 14 d period at physiologically relevant fluxes and are shown to significantly reduce long-term (14 day) bacterial biofilm formation against Staphylococcus epidermidis and Pseudonomas aeruginosa in a CDC bioreactor model. After 7 h of catheter implantation in the jugular veins of rabbit, the SNAP CarboSil catheters exhibit a 96% reduction in thrombus area (0.03 ± 0.01 cm2/catheter) compared to the controls (0.84 ± 0.19 cm2/catheter) (n = 3). These results suggest that SNAP impregnated CarboSil can become an attractive new biomaterial for use in preparing intravascular catheters and other implanted medical devices