CONVERSION OF WOODY BIOMASS TO ENERGY, CHEMICALS AND MATERIALS

Conversion of renewable biomass to chemicals and energy is imperative to sustain our way of life as known to today. Fossil fuels have become the predominant energy source today. However, fossil deposits are limited and not renewable. Biomass is a reliable source of chemicals and energy that can be replenished at the rate of our needs. The biorefinery is a concept for the collection of processes used to convert biomass to chemicals and energy. The Biorefinery is a “catch and release” way of using carbon that is beneficial to the environment and the economy. Discussions are made for the elements of the wood-based biorefinery as proposed at SUNY ESF (College of Environmental Science and Forestry): hot-water extraction, hydrolysis, membrane separation / concentration, pulping, and biological conversion of sugars to biofuels, chemical, and biopolymers, conversion of residual woody biomass to reconstituted wood products. Hemicelluloses are the most easily separable main component of woody biomass and thus form the bulk of the extracts obtained in hot-water extraction of wood. Hydrolysis of hemicelluloses produces 5-carbon sugars (mainly xylose), 6-carbon sugars (mainly glucose and mannose), and acetic acid. Fermentation of wood extract hydrolysate can produce biofuel: ethanol and butanol. Brief discussions will also be presented on the utilization of the residual woodchips: pulp and paper, reconstituted wood products, wood pellets, and burning / gasification for energy. Hemicellulose contributes to the weight but not much to the strength of the material and thus hemicellulose-extracted woody biomass might produce lighter stronger particle board products

ETHANOL PRODUCTION FROM A MEMBRANE PURIFIED HEMICELLULOSIC HYDROLYSATE DERIVED FROM SUGAR MAPLE BY PICHIA STIPITIS NRRL Y-7124

In an effort to devise inexpensive and sustainable production of ethanol fuel, experiments were conducted to establish conditions for Pichia stipitis NRRL Y-7124 to ferment a membrane treated wood hydrolysate derived from sugar maple to produce ethanol. The degree of aeration required to effectively utilize xylose, produce ethanol, and minimize xylitol formation as well as the optimal hydrolysate concentration were the conditions examined. P. stipitis produced the highest concentrations of ethanol in shake flasks at 150 rpm (14.3 g/L in 71 h), and 50% hydrolysate maximized ethanol yield (12.4 g/L in 51.5 h). In the 50% hydrolysate cultures, P. stipitis produced ethanol at a rate of 0.24 g/Lh with a yield of 0.41 g ethanol/g wood-derived carbohydrate

Iodine-123 metaiodobenzylguanidine scintigraphic assessment of the transplanted human heart: Evidence for late reinnervation

Objectives.This study attempted to determine whether cardiac sympathetic reinnervation occurs late after orthotopic heart transplantation.Background.Metaiodobenzylguanidine (MIBG) is taken up by myocardial sympathetic nerves. Iodine-123 (I-123) MIBG cardiac uptake reflects intact myocardial sympathetic innervation of the heart. Cardiac transplant recipients do not demonstrate I-123 MIBG cardiac uptake when studied <6 months from transplantation. However, physiologic and biochemical studies suggest that sympathetic reinnervation of the heart can occur >1 year after transplantation.Methods.We performed serial cardiac I-123 MIBG imaging in 23 cardiac transplant recipients early (<-1 year) and late (>1 year) after operation. In 16 subjects transmyocardial norepinephrine release was measured late after transplantation.Results.No subject had visible I-123 MIBG uptake on imaging <1 year after transplantation. However, 11 (48%) of 23 subjects developed visible cardiac I-123 MIBG uptake 1 to 2 years after transplantation. Only 3 (25%) of 12 subjects with a pretransplantation diagnosis of idiopathic cardiomyopathy demonstrated I-123 MIBG uptake compared with 8 (73%) of 11 with a pretransplantation diagnosis of ischemic or rheumatic heart disease (p = 0.04). All 10 subjects with a net myocardial release of norepinephrine had cardiac I-123 MIBG uptake; all 6 subjects without a net release of norepinephrine had no cardiac I-123 MIBG uptake.Conclusions.Sympathetic reinnervation of the transplanted human heart can occur >1 year after operation, as assessed by I-123 MIBG imaging and the transmyocardial release of norepinephrine. Reinnervation is less likely to occur in patients with a pretransplantation diagnosis of idiopathic cardiomyopathy than in those with other etiologies of congestive heart failure

Controlled release of ethanehydroxy diphosphonate from polyurethane reservoirs to inhibit calcification of bovine pericardium used in bioprosthetic heart valves

Calcification (CALC) of bioprosthetic heart valves (BHVs) fabricated from either glutaraldehyde-pretreated bovine pericardial tissue or porcine aortic valves is the most frequent cause of clinical failure of these devices. Previous studies have demonstrated that calcification is inhibited by diphosphonate compounds released into the vicinity of bioprosthetic tissue implanted subcutaneously in rats. Controlled release of the anticalcification agent ethanehydroxy diphosphonate (EHDP), as a 1:1 mixture of Na2 EHDP and CaEHDP from cylindrical polyurethane (PU) reservoirs (o.d. = 0.36 cm i.d. = 0.33 cm, length = 4 cm) fabricated by solvent casting was assessed in vitro and in vivo. The diffusivity (D), determined independently using standard diffusion cells, for ionic EHDP diffusion across the PU membrane was 1.2 x 10 cm2/s. Volume influx of buffer into the reservoirs in vitro was observed experimentally to reach a maximum at 7.8 days (288 +/- 44 [mu]l) with a biexponential decline to 147 +/- 6 [mu]l at 70 days. The cumulative EHDP released in vitro after 70 days was 4.2 +/- 0.6% (4.8 +/- 0.7 mg) compared to 15.7 +/- 3.2% (18.1 +/- 3.7 mg) in vivo (subcutaneously in 3 week-old, male, CD rats) over 21 days. The release rate of EHDP from the reservoirs was not a zero-order process. Reservoir administration of EHDP effectively inhibited pericardial BHV-CALC in 21-day subdermal explants (Ca2+ = 4.5 +/- 1.4 [mu]g Ca2+/mg tissue; control, Ca2+ = 120 +/- 13 [mu]g Ca2+/mg tissue) without diphosphonate-related untoward effects at a dose of approx. 3 mg/kg per day.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28671/1/0000488.pd

Persistent elastic behavior above a megathrust rupture patch: Nias island, West Sumatra

We quantify fore-arc deformation using fossil reefs to test the assumption commonly made in seismic cycle models that anelastic deformation of the fore arc is negligible. Elevated coral microatolls, paleoreef flats, and chenier plains show that the Sumatran outer arc island of Nias has experienced a complex pattern of relatively slow long-term uplift and subsidence during the Holocene epoch. This same island rose up to 2.9 m during the Mw 8.7 Sunda megathrust rupture in 2005. The mismatch between the 2005 and Holocene uplift patterns, along with the overall low rates of Holocene deformation, reflects the dominance of elastic strain accumulation and release along this section of the Sunda outer arc high and the relatively subordinate role of upper plate deformation in accommodating long-term plate convergence. The fraction of 2005 uplift that will be retained permanently is generally <4% for sites that experienced more than 0.25 m of coseismic uplift. Average uplift rates since the mid-Holocene range from 1.5 to −0.2 mm/a and are highest on the eastern coast of Nias, where coseismic uplift was nearly zero in 2005. The pattern of long-term uplift and subsidence is consistent with slow deformation of Nias along closely spaced folds in the north and trenchward dipping back thrusts in the southeast. Low Holocene tectonic uplift rates provide for excellent geomorphic and stratigraphic preservation of the mid-Holocene relative sea level high, which was under way by ∼7.3 ka and persisted until ∼2 ka

Controlled release of 1-hydroxyethylidene diphosphonate: in vitro assessment and effects on bioprosthetic calcification in sheep tricuspid valve replacements

Calcification (CALC) is the most frequent cause of the clinical failure of bioprosthetic valves (BHV's). Controlled-release (paravalvar) administration of the anticalcification agent ethanehydroxydiphosphonate (EHDP), as either Na2EHDP or in combination (1:1) with the less soluble CaEHDP, from a silicone rubber matrix (20% w/w EHDP) was studied both in vitro and in vivo for the prevention of BHV CALC. Seventeen sheep (6-7 months old, male, Suffolk) underwent tricuspid valve replacement using Hancock I, 25 mm porcine aortic bioprostheses. BHV explant evaluation after 16-20 weeks revealed that two of the 7 control BHV were calcified (139 +/- 20.8 [mu]gCa2+/mg of tissue), while none of the 9 BHV retrieved from animals receiving controlled release EHDP demonstrated CALC (4.41 +/- 1.09 [mu]g Ca2+/mg of tissue). No adverse effects of EHDP on bone or calcium metabolism were noted. The cumulative percent of EHDP released per electron microprobe analysis was 40.4% +/- 9.68 (Na, CaEHDP) to 79.0% +/- 4.82 (Na2EHDP) in vivo compared to 35.7% +/- 7.72 and 78.6 +/- 11.1 in vitro, respectively. Assessment of the Young's modulus (Y) using thermomechanical analysis (TMA) revealed a 1.5-fold (Silastic Q7-4840) to 9.5-fold (Silastic 382) increase in Y following drug loading. The Y for explanted, Silastic Q7-4840 polymer matrices ranged from 2.84 x 104 to 5.57 x 105 dyne/cm2. In vitro osmotic related matrix swelling of the Na2EHDP loaded, unsealed matrices (20% w/w) after 75 days was minimized to a 35.8% increase in weight due to coincorporation of CaEHDP with Na2EHDP in a 1:1 ratio and was further reduced (22.2% increase in weight) by sealing 76% of the releasing surface, compared to Na2EHDP matrices which demonstrated a 414% and 141% increase in weight, respectively.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27902/1/0000322.pd

Controlled Crystallization of the Lipophilic Drug Fenofibrate During Freeze-Drying: Elucidation of the Mechanism by In-Line Raman Spectroscopy

We developed a novel process, “controlled crystallization during freeze-drying” to produce drug nanocrystals of poorly water-soluble drugs. This process involves freeze-drying at a relatively high temperature of a drug and a matrix material from a mixture of tertiary butyl alcohol and water, resulting in drug nanocrystals incorporated in a matrix. The aim of this study was to elucidate the mechanisms that determine the size of the drug crystals. Fenofibrate was used as a model lipophilic drug. To monitor the crystallization during freeze-drying, a Raman probe was placed just above the sample in the freeze-dryer. These in-line Raman spectroscopy measurements clearly revealed when the different components crystallized during freeze-drying. The solvents crystallized only during the freezing step, while the solutes only crystallized after the temperature was increased, but before drying started. Although the solutes crystallized only after the freezing step, both the freezing rate and the shelf temperature were critical parameters that determined the final crystal size. At a higher freezing rate, smaller interstitial spaces containing the freeze-concentrated fraction were formed, resulting in smaller drug crystals (based on dissolution data). On the other hand, when the solutes crystallized at a lower shelf temperature, the degree of supersaturation is higher, resulting in a higher nucleation rate and consequently more and therefore smaller crystals. In conclusion, for the model drug fenofibrate, a high freezing rate and a relatively low crystallization temperature resulted in the smallest crystals and therefore the highest dissolution rate

Magnetic hyperthermia controlled drug release in the GI tract : solving the problem of detection

Drug delivery to the gastrointestinal (GI) tract is highly challenging due to the harsh environments any drug- delivery vehicle must experience before it releases it’s drug payload. Effective targeted drug delivery systems often rely on external stimuli to effect release, therefore knowing the exact location of the capsule and when to apply an external stimulus is paramount. We present a drug delivery system for the GI tract based on coating standard gelatin drug capsules with a model eicosane- superparamagnetic iron oxide nanoparticle composite coating, which is activated using magnetic hyperthermia as an on-demand release mechanism to heat and melt the coating. We also show that the capsules can be readily detected via rapid X-ray computed tomography (CT) and magnetic resonance imaging (MRI), vital for progressing such a system towards clinical applications. This also offers the opportunity to image the dispersion of the drug payload post release. These imaging techniques also influenced capsule content and design and the delivered dosage form. The ability to easily change design demonstrates the versatility of this system, a vital advantage for modern, patient-specific medicine