Search

This article explores emerging science and technology advances relevant to the 1972 Biological and Toxin Weapons Convention (BWC), and existing and needed frameworks for their identification, risk ...

This study used the National Surgical Quality Improvement Program to evaluate octogenarians who underwent total shoulder arthroplasty (TSA). Specifically, we evaluated: (1) patient demographics; (2) perioperative factors; and (3) 30-day postoperative complications. Compared to controls, the octogenarians had more females, white patients, lower BMIs, fewer smokers, less functionally independent, higher ASA scores, shorter operative times, and longer LOS. Octogenarians had greater odds for developing any (OR = 2.05; 95%CI, 1.70–2.46), any major (OR = 2.28; 95%CI, 1.66–3.13), and any minor (OR = 1.99; 95%CI, 1.63–2.45) complications. Perioperative risk management strategies for elective TSA in the elderly may help mitigate the increased perioperative risks associated with age.

Background The biologic factors associated with shoulder osteoarthritis (OA) have not been elucidated. The purpose of this study was to investigate osteoarthritic biomarkers of the shoulder. To our knowledge, this is the first study to analyze shoulder cartilage for OA-associated genes and to examine human shoulder cartilage for a possible biomarker, connexin 43 (Cx43). Materials and methods Cartilage from 16 osteoarthritic and 10 nonosteoarthritic humeral heads was assessed for expression of the following genes by real-time polymerase chain reaction: types I, II, and X collagen; matrix metalloproteinases (MMPs); tissue inhibitors of MMP (TIMPs); interleukins; versican; cyclooxygenase 2 (Cox-2); inducible nitric oxide synthase (iNOS); tumor necrosis factor α (TNF-α); aggrecanase 2 (ADAMTS5); and Cx43. Results In osteoarthritic shoulders, Cx43, Cox-2, versican, collagen type I, ADAMTS5, MMP-3, and TNF-α expressions were significantly increased compared with controls. TIMP-3 and iNOS trended toward significance, with robust expression in osteoarthritic shoulders and low expression in nonosteoarthritic shoulders. In osteoarthritic shoulders, gene expression of Cx43, ADAMTS5, collagen type I, Cox-2, versican, and TIMP-3 showed predominance (85-, 33-, 13-, 12-, 11.5-, and 3-fold increases, respectively) relative to nonosteoarthritic controls. Spearman correlation analysis showed significant correlations between Cx43 and collagen (types I, II, and X), MMP-9, TIMP-2 and TIMP-3, versican, Cox-2, iNOS, and ADAMTS5. Conclusions Certain genes are markedly upregulated in osteoarthritic shoulders compared with nonosteoarthritic shoulders, with Cx43, Cox-2, versican, collagen type I, ADAMTS5, MMP-3, and TNF-α expression being significantly increased. These genes might be useful biomarkers for examining shoulder OA. Clinical relevance Identification of osteoarthritic biomarkers can help us better understand shoulder OA and build the foundation for future research on disease progression and treatments.

This study investigates the CBM generation and CO2 storage capacity of the coal-bearing Permian age Rio Bonito Formation in the Santa Terezinha Coalfield, Paraná Basin, Brazil. In order to assess the volumetrics of the coal seams a fourth-order sequence stratigraphic framework of the coal-bearing succession was established based on parasequence boundaries. A 3D geometric model based on data from 36 well logs was developed, and enabled subdivision of the study area into regions with very different CBM potential, due to variable cumulative coal thickness, depths and presence/absence of diabase. Strata of the coal-bearing Rio Bonito Formation were penetrated in well CBM001-ST-RS at a depth of 575.70 to 638.35 m, from which twelve coal seams and carbonaceous shales, ranging in thickness from 0.15 to 1.77 m, were retrieved for analysis. Gas desorption values range from 0.3 to 2.2 cm3/g. Gas composition is dominated by methane (> 94 Vol%). Gas isotopic analyses suggest a mixed biogenic and thermogenic origin. Vitrinite reflectance indicate a rank of high volatile A bituminous coal, with semi-anthracite occurring in contact with igneous rocks. The majority of the samples has vitrinite group contents > 50 Vol%, mineral matter-free basis. Ash yields range from 42.1 to 92.8 wt.%, whereas sulphur contents range from 0.1 to 7.7 wt.%. Volatile matter and calorific values (dry ash-free) range from 37.6 to 79.4 wt.%, and 2352 to 8107 kcal/kg, respectively. Mineral composition of the samples is dominated by quartz and kaolinite, whereas major element analyses show that SiO2 is most abundant. The 3D model allowed volumetric calculation for the coal seams and formed the basis for calculations of gas content and CO2 storage capacity. According to the 3D model the four coal-bearing parasequences of the study area contain a coal volume on the order of 3212 × 10 6 m3 suggesting a resource base of 5.5 × 109 m3 of methane associated with the coal seams and carbonaceous shales of the study area. The methane and carbon dioxide sorption capacities show a high positive correlation with TOC content. The coal seams appear to be undersaturated, since sorption capacity is significantly higher than the desorbed gas volume. The CO2 sorption capacity at mean reservoir pressure was up to 7 times higher than the methane sorption capacity. Based upon sorption capacities and reservoir conditions, a storage potential of 13.8 Gt CO2 in coal seams and carbonaceous shales of the study area is estimated.

Purpose Increased ulnar variance has been shown to lead to diminished load borne by the distal radius. The purpose of this study was to determine the correlations among ulnar variance, bone mineral density, and load to failure at the distal radius. Methods Posteroanterior radiographs and computed tomographic scans were taken of 12 cadaveric forearms in neutral rotation. Ulnar variance was measured for each wrist by the method of perpendiculars. Measurements of cortical, trabecular, and combined bone density were made at the distal radius. We performed linear regression analysis and correlation analysis to determine the relationship between bone densities and ulnar variance measurements. Next, we loaded the 12 cadaveric radii to failure under axial compression. Linear regression analysis and correlation analysis were then performed to determine the relationship between load to failure and both ulnar variance and cortical density. Results Increased ulnar variance was significantly correlated with decreased cortical bone density at the distal radius and both were correlated with decreased load to failure. We found no correlation between ulnar variance and trabecular density or combined trabecular and cortical bone density at the distal radius. Conclusions Our study found that increased ulnar variance and decreased cortical bone mineral density correlates with decreased load to failure under axial compression. Clinical relevance Ulnar variance is linked to both bone quality and load to failure at the distal radius.

INTRODUCAO: As bioproteses valvares cardiacas estao relacionadas a eventos tromboembolicos, infecciosos e degenerativos. Seu desgaste e atribuido principalmente a desnaturacao do colageno. O glutaraldeido, metodo predominante de preservacao de bioproteses, favorece o processo de calcificacao e limita sua durabilidade. Diversas tecnicas tentam conter o processo degenerativo das bioproteses. OBJETIVO: Avaliar o processo de calcificacao, in vivo, de heteroenxertos pulmonares valvados, preservados em meio nao-aldeidico (L-Hydro®). METODOS: Dezessete carneiros foram submetidos a substituicao do tronco da arteria pulmonar por enxerto tubular valvado de pericardio bovino. Os animais foram distribuidos em dois grupos: Grupo L-Hydro® (teste / n=14) e Grupo Glutaraldeido (controle /n=3). Cerca de 150 dias pos-implante os animais foram sacrificados, necropsiados e as proteses submetidas a estudo anatomopatologico, avaliacao radiologica e dosagem do calcio por espectrofotometria de absorcao atomica. A analise estatistica foi obtida por meio dos testes exato de Fisher, T de Student ou Mann-Whitney (significância: 5%). RESULTADOS: A avaliacao radiologica, macroscopia, microscopia e dosagem de calcio por espectrofotometria de absorcao atomica demonstraram maior calcificacao nas proteses do Grupo Glutaraldeido, quando comparadas as proteses do Grupo L-Hydro® (P=0,001). Sete animais do Grupo L-Hydro® (50%) apresentaram aderencia das cuspides a parede do tubo (P=0,228). CONCLUSOES: As proteses preservadas em L-Hydro® demonstraram-se mais resistentes a calcificacao, quando comparadas as preservadas em glutaraldeido.

OBJETIVOS: A necessidade de substituição da valva, aorta ascendente e reimplante coronariano em pacientes onde a anticoagulação é indesejável, é crescente. Avaliamos em animais o comportamento hemodinâmico de um conduto valvado aórtico feito com pericárdio bovino tratado pelo glutaraldeído (CVAP). MÉTODOS: Para isto, implantamos CVAPs em oito ovinos e os explantamos após 150 dias de pós-operatório. Realizouse estudo angiográfico e hemodinâmico no pré-operatório e antes do explante. EcoDopplercardiogramas foram realizados nos dias 30 e 150 de pós-operatório (teste) e também em cinco ovinos não operados. Após explantados, submetemos os CVAPs à avaliação macroscópica, radiológica e histológica por microscopia óptica. RESULTADOS: Na análise hemodinâmica, as pressões arterial e capilar pulmonar aumentaram (P

Calcification of glutaraldehyde-treated bioprosthetic heart valves is a major cause of long-term failure. We studied porcine aortic valves treated by the L-Hydro process and implanted into 14 juvenile sheep (group 1). Another 10 sheep were implanted with glutaraldehyde-treated porcine bioprostheses (group 2). The animals were sacrificed after 150 days and the explanted valves were analyzed for calcification. Hemodynamic measurements by echocardiography and angiography were carried out prior to sacrifice. Macroscopic analysis showed calcification and loss of mobility of the leaflets in all group 2 implants and in one group 1 implant. Light microscopy showed foci of calcification in all group 2 implants and in 3 valves from group 1. A significant reduction in the level of calcification was found in porcine bioprostheses treated by the L-Hydro process and implanted into the juvenile sheep model.

Background Humeral loosening is an uncommon etiology for revision shoulder arthroplasty. We aimed to evaluate the radiographic and clinical outcomes of a short-stem press-fit humeral component after primary total shoulder arthroplasty. Methods We reviewed our patient database, from January 2008 to December 2011, for primary total shoulder arthroplasties performed with a short-stem press-fit humeral component. Radiographs and clinical outcomes were evaluated in the immediate postoperative period and at the most recent follow-up, with at least 24 months of data for all patients. Results There were 73 shoulders that met our inclusion criteria, but 4 underwent revision before 2 years' follow-up. Only 1 of these 4 was revised for aseptic humeral loosening. Sixty-nine shoulders had at least 24 months of radiographic follow-up, and 62 had radiographic and clinical follow-up. Of the 69 shoulders, 5 underwent revision for humeral loosening: 1 for aseptic loosening and 4 for infection. Two other shoulders with humeral loosening were asymptomatic, and the patients refused revision surgery. The overall revision rate for humeral loosening was 8.2% (6 of 73 shoulders). Radiolucent zones of any size were seen in 71.0%, with 8.7% of these shoulders identified as having humeral stems at risk of future loosening. Significant improvements were made in most of the measured clinical outcomes. Conclusions A high percentage of radiolucency was seen around the short-stem press-fit humeral components evaluated in this study at short-term follow-up. The overall rates of loosening and revision for the humeral implant examined in this study are higher than those noted in other recent studies evaluating press-fit stems. The cause of radiolucency and humeral loosening for this implant is not fully understood.

Background Glenoid components often cause total shoulder arthroplasty failure. This study examines short-term to midterm radiographic and clinical results of a hybrid glenoid component with 3 cemented peripheral pegs and a central peg, which allows biologic fixation with use of native humeral head autograft. Methods In 4 years, 80 glenoid components were implanted during primary total shoulder arthroplasty with at least 2-year follow-up data. Within 12 months, 4 shoulders were revised and excluded from final analyses. Seven patients did not complete their questionnaires. Outcomes data included the American Shoulder and Elbow Surgeons (ASES) questionnaire, Constant score, and satisfaction score. A shoulder and elbow fellowship-trained surgeon, not involved in the care of these patients, analyzed radiographs for radiolucent lines, glenoid seating, and radiodensity in between the flanges of the central peg. Results Only 1 of 80 shoulders was revised for aseptic glenoid loosening. At final follow-up, 81.6% had a radiolucency grade of 0 or 1. Nearly 90% had a glenoid seating grade of A or B. Grade 2 or 3 bone around the central peg was seen in 88.2%. No statistical association existed between Walch glenoid types and radiolucency grades, bone grades around the central peg, perfect radiolucency grade, seating grade, and grade 3 bone around the central peg. There was significant improvement in mean ASES score, adjusted ASES pain score, Constant score, and satisfaction score as well as in forward flexion, abduction, and external rotation. Conclusions The hybrid glenoid can produce stable radiographic and clinical outcomes at short- to medium-term follow-up.

OBJETIVO: O revestimento endotelial in vitro das biopróteses com células do hospedeiro parece ter ação protetora contra a calcificação, trombose, inflamação e o desgaste mecânico. O objetivo deste estudo é analisar o potencial para endotelização in vivo com um processo alternativo de preservação tecidual (L-HydroTM). MÉTODO: A preservação L-Hydro consiste na extração controlada de substâncias antigênicas pela ação do polietilenoglicol e na incorporação de um agente antiinflamatório e antitrombótico. Para testar a re-endotelização in vivo, foram implantadas em posição mitral de ovelhas jovens sete próteses porcinas L-Hydro (grupo teste) e três convencionais preservadas com glutaraldeído (GA - grupo controle). Estas próteses foram explantadas com 150 dias após avaliação ecocardiográfica e angiográfica. A avaliação histológica consistiu em microscopia de varredura e transmissão, e imuno-histoquímica (von Willebrand) para detecção da presença e viabilidade das células endoteliais, respectivamente. Utilizou-se o teste-t não pareado para análise estatística. RESULTADOS: Não houve diferença hemodinâmica significativa nos dois grupos (p>0.05). Entretanto, a microscopia mostrou no grupo teste um revestimento endotelial quase completo formado por células confluentes, viáveis com expressão do fator vW, as quais encontravam-se em contato direto com a matriz colagênica subjacente. No grupo controle (GA), as superfícies valvulares estavam recobertas por fibrina, macrófagos, cálcio, material trombótico e células endoteliais esparsas com expressão fraca do fator vW, e com pouco contato direto com o colágeno. CONCLUSÕES: Estes dados indicam que o processo L-HydroTM permite endotelização espontânea com boa adesividade celular à matriz colagênica, o que favoreceria maior durabilidade às biopróteses porcinas. OBJECTIVE: A protective layer of endothelial cells (EC) of host origin on the entire surface of bioprosthetic heart valves has never been reported. Current commercial bioprosthetic heart valves are commonly preserved in glutaraldehyde (GA) and are cytotoxic to host cells preventing spontaneous endothelialization. The aim of this study is to demonstrate the potential for in vivo endothelialization of heart valves treated by the L.-Hydro™ preservation process. METHOD: L-Hydro™ preservation process consists of mild extraction of antigenic substances by the action of polyethyleneglycol and incorporation of an anti-inflammatory and a anti-thrombotic agent. Seven stented porcine valves treated by the L-Hydro™ process and three GA-fixed porcine valves were implanted in the mitral position of juvenile sheep. The valves were evaluated by echocardiography and angiography prior to sacrifice at five months. Recovered valves were also histologically and histo-chemically evaluated. RESULTS: There were no hemodynamic differences between the groups. However, scanning and transmission electron microscopy showed a nearly complete coverage of EC on the surfaces of all leaflets in the L-Hydro™ treated valves. The EC were in direct contact with the underlying collagen layer and expressed von Willebrand-related antigens (vW). The surfaces of the GA-treated valves were covered by fibrin deposition, macrophages, calcium and thrombotic material. Only sparse EC were observed and contact of the EC where the underlying tissue was incomplete. CONCLUSION: These data indicate that L-Hydro™ treated porcine valve tissues are capable of inducing spontaneous endothelialization with evidence of strong cell attachment of the new endothelium to the collagen matrix.

INTRODUCTION: Often, studies on aortic prosthetic valves analyze their performance not at the primitive position, but using tricuspid and mitral ones or inserting it in the descending aortic area. Taking that into account, it would be relevant to observe results in those studies in which the conclusions are based on their original implantation. MATERIAL AND METHODS: Thirty young sheep, 28 males and 2 females, were operated on. Ages ranged 4.4 to 6.3 months and weights 25 to 37 Kg. Extra corporeal circulation (ECC) was applied to all the animals, always guided by the conventional criteria, that is to say, the arterial cannula was inserted in the thoracic aorta just past the arterious ducts and the venous cannulae, a single one, was placed in the right atrium. The operation was performed according to the principle of moderately low body temperature- 29oC- and cold cristalloid cardioplegia, in the aortic root, to induce; but otherwise was utilized blood to the maintenance. Following with the technique proposed, the aortic valve of the animal heart was completely excised and finally implanted the valved tube stentless, not forgetting the refixation of the coronary main. The sheep were kept in clinical and laboratorial observation during thirty days in what was included a echocardiogram in the end. RESULTS: The results demonstrated 8 intraoperatory deaths (26.6%), and 6 during the following (27.7%). The mean time of ECC was 98 minutes. The dimension of the majority prothetics valves were 21 and 23. Only two valves evoluted with mild insufficiency, none denoted evidences of the endocarditis neither of leaflets perfuration, the mean fraction of ejection was 74%, the left ventricle had its wall preserved in all cases. CONCLUSION: This experimental model can certainly reproduce nearly the reality, confirming good parameters of prothetics stentless evaluation in the aortic position. And the sheep declared itself to be pleasant, which helps us its control during the whole study.

Objective: To present long-term results after mitral valve replacement with stent mounted glutaraldehyde preserved aortic allografts in patients older than 15 years. The clinical support for this study was to combine the glutaraldehyde technique of biological tissue preservation with the advantages of allografts when compared to xenografts. This was demonstrated in previous studies using other methods of tissue processing. Methods: Between September 1984 and November 1994, 70 patients aged 16‐77 years (mean 35.4 years) underwent mitral valve replacement with this preserved and mounted allograft. Of these, 40 patients (57.2%) were aged 16‐35 years and 15 (21.4%) were 20 years old or younger; 46 (65.7%) were females and 24 (34.3%) males. Single mitral valve replacement was performed in 60 patients and 10 were also subjected to other combined cardiac procedures. Human aortic valves were obtained during routine autopsy, processed in glutaraldehyde and mounted into flexible stents, using the same technique as that used for porcine bioprostheses. Results: Hospital mortality was 1.4%. Total follow-up was 543.1 patient-years, corresponding to a mean follow-up of 7.9 years per patient. Echocardiography demonstrated a hemodynamic performance similar to porcine bioprostheses. Late mortality was 0.79 0.6% per patient-year and the causes were congestive heart failure in 2, prosthetic endocarditis in 1 and acute myocardial infarction in 1. The 12-year actuarial survival was 92.49 3.2%. The incidence of late complications was 5.291.2% per patient-year, including congestive heart failure, prosthetic endocarditis, periprosthetic leak, thromboembolic episodes, recurrence of rheumatic disease, coronary artery disease and allograft failure. Complications related to heart disease represented 2.89 0.6% and allobioprosthesis-related 2.49 0.5% per patient-year. The 12-year actuarial freedom from primary valve failure was 81.09 15.0%. The incidence of reoperations was 1.59 0.8% per patient-year and the main indication was prosthetic endocarditis. Other causes were periprosthetic leak, aortic insufficiency in the native aortic valve and allobioprosthesis dysfunction. Functional results demonstrated a significant improvement in patients clinical condition. Conclusion: This 12-year follow-up shows a very low incidence of primary allograft failure for patients older than 15 years undergoing mitral valve replacement, and much superior than our results with porcine bioprosthesis in the same age group. This supports our assumption that this investigational valve represents a new advance in cardiac valve surgery. © 1998 Elsevier Science B.V. All rights reserved.

OBJETIVO: Buscando novas formas de preservação de tecidos utilizamos o polietileno-glicol, método L-Hydro (LH), que consiste na extração controlada de substâncias antigênicas e incorporação de agente antinflamatório e antitrombótico. MÉTODOS: Em dez carneiros jovens, substituímos o tronco pulmonar, em sete, por homoenxertos pulmonares (HP) tratados pelo processo L-H e, em três, por HP a fresco, implantados ortotopicamente, seguidos por 320 dias. Os carneiros foram avaliados por exames laboratoriais e ecocardiográficos. Ao cabo dos 320 dias foram sacrificados, procedendo-se à avaliação hemodinâmica, radiológica, macro/microscópica, óptica e eletrônica, varredura e transmissão. Resultados foram analisados pelo teste t de Student de amostras independentes para dados contínuos, análise de variância para medidas repetidas, pelo teste exato de Fisher para dados categóricos. RESULTADOS: Evolução clínica e exames laboratoriais não conseguiram estabelecer diferenças significativas entre os grupos. Ecocardiograma revelou diferença quanto ao gradiente médio pulmonar, significativa aos 10 meses, maior no grupo controle. Avaliação radiológica e macroscópica não estabeleceu diferenças. Na avaliação microscópica, óptica/eletrônica, células de revestimento e intersticiais foram encontradas nos dois grupos igualmente. O porcentual de revestimento celular calculado nos dois grupos foi semelhante. Nódulos de celularidade foram observados somente no grupo de homoenxertos a fresco. CONCLUSÕES: Estes dados indicam que os dois grupos apresentaram desempenho clínico e hemodinâmico semelhante. Ao ecocardiograma o grupo LH apresentou melhor desempenho, e evidências histológicas de repopulação celular intersticial e endotelial. Na análise macro/microscópica, óptica/eletrônica, o grupo L-Hydro apresentou macroscopia, estrutura histológica e ultraestrutural semelhante ao homoenxerto fresco, à exceção de nódulos de maior celularidade intersticial, presentes apenas no homoenxerto a fresco. OBJECTIVE: In an effort to make available homografts preserved in a simpler and less costly way, we evaluated the polyethyleneglycol, L-Hydro (LH) method, that consists in the controlled extraction of antigenic substances and the incorporation of anti-inflammatory and anti-thrombotic agent. METHODS: We substituted the pulmonary trunk in ten ovines, seven received LH treated pulmonary homografts and three, fresh pulmonary homografts, orthotopically implanted and followed-up for 320 days. Ovines where evaluated by means of laboratory tests, echocardiographic exams. At the 320 days, were euthanized, hemodynamic, radiology, macroscopic, optic/electronic microscopic, scanning/transmission evaluations were performed. Results were analyzed by Student t test of independent samples for continuous data, by variance analysis of repeated measures, and by Fisher exact test for categorical data. RESULTS: We couldn't establish relevant differences in clinical evolution and laboratory tests between groups. Echocardiogram revealed difference in pulmonary medium gradient, which was significant 10 months follow-up, higher in the control group. Radiologic and macroscopic evaluations didn't established differences. In the optic/electronic microscopic evaluation, liner and interstitial cells were equally found in both groups. The cell liner percent calculated in both groups was similar. Cellularity nodules were observed only infresh homograft group. CONCLUSIONS: These data indicate that both groups presented similar clinical/hemodynamic performances. The LH group's echocardiogram presented a better performance. It also presented histological evidences of interstitial and endothelial cell repopulation. In the macro/optic and electronic microscopic analysis, group L-H presented macroscopy/histological structure and ultra-structural similar to the fresh group, with the exception of nodules with higher interstitial cellularity, present only in the fresh homograft group.

We report precision 1H(e,e′π+)n measurements in the Δ(1232) resonance at Q2=0.127(GeV/c)2 obtained at the MIT-Bates out-of-plane scattering facility. These are the lowest, but nonzero, Q2 measurements in the π+ channel. The data offer tests of the theoretical calculations, particularly of the background amplitude contributions. The chiral effective field theory and Sato-Lee model calculations are not in agreement with this experiment. © 2011 American Physical Society.

Experimental details of a virtual Compton scattering (VCS) experiment performed on the proton at the MIT-Bates out-of-plane scattering facility are presented. The VCS response functions PLL-PTT/P TT and PLT have been measured at Q2=0.057GeV2/c2. The generalized electric and magnetic polarizabilities, α(Q2) and β(Q2), and the mean-square electric polarizability radius rα2 are obtained from a dispersion analysis of the data. The results are in good agreement with O(p3) heavy baryon chiral perturbation and indicate the dominance of mesonic effects in the polarizabilities. © 2011 American Physical Society.

As there is currently no suitable valved pulmonary conduit for small children, porcine conduits treated by the L-Hydro process were implanted into 9 newborn lambs to investigate growth potential. Of the 8 survivors, 7 were kept alive for 12 months after implantation. The diameter of the conduit and gradient across the valve were evaluated at surgery and at 3 and 9 months postoperatively using bidirectional echocardiographic and angiographic methods. After sacrifice, histological and radiological analyses were performed. The mean weight of the animals was 4.2 ± 1.1 kg at implantation and 43.1 ± 6.2 kg at sacrifice. There was a significant increase in mean valve area from 139.9 ± 18.0 mm2 at implantation to 443.5 ± 89.2 mm2 at 12 months. Pre-sacrifice angiography showed no transvalvular gradient, and radiographic analysis did not reveal significant conduit wall or leaflet calcification in any of the animals. Histological examination of the grafts demonstrated total integration, with native-like intact valve leaflets. Thus functional evaluation, echocardiography, and histology demonstrated growth of the grafts with completely endothelialized and apparently normal pulmonary valve leaflets without calcification.

Peat cores from three aquatic environments (freshwater, brackish and marine have been analyzed for organic, pyritic and sulfatic sulfur contents and isotope ratios. Peat collected from each environment has a unique combination of sulfur content, distribution and isotope ratio. Freshwater peat from the Okefenokee Swamp contains the least sulfur (0.26 to 0.48%, primarily organic sulfur) and is vertically uniform in sulfur content and isotope ratio. The organic sulfur isotope ratio of the Okefenokee pear (+ 12.3 to + 12.8 per mil) is similar to that of sulfate in associated surface waters. Cores from presently brackish and marine peats from the Florida Everglades have high organic, pyritic and sulfatic sulfur contents with vertical variability in sulfur content and isotope ration. The isotope ratio of organic sulfur in the brackish and marine peat is lighter than that of sulfate associated with their respective peat-forming environments. Organic sulfur in the marine peat is isotopically lighter than in the brackish peat. Freshwater peats subsequently overlain by sediment associated with brackish to marine waters may have a sulfur content, distribution and isotopic ratio indistinguishable from peats derived under brackish or marine conditions. The primary source of sulfur in peats is dissolved sulfate associated with the peat-forming system. The sulfate concentration of the waters in which a peat forms is of major importance in determining the isotopic composition of the sulfur form found in peat. The content, distribution and isotopic ratio of low and high sulfur peats are similar to those reported for coals, indicating that the fundamental sulfur geochemistry of coals may have been established during the peat-forming stage of coalification. The organic sulfur content and isotope ratio of a coal may be useful in estimating the relative sulfate ion concentration of the waters present during the peat-forming stage of coalification where transgressive sequences are not involved. The sulfate ion concentration of paleowaters could be used to interpret the paleoenvironment during the peat-forming stage of coalification and thus, information about the organic sulfur content and isotope ratio of coals may prove useful in helping to assess coal quality in advance of mining.

The mean square polarizability radii of the proton have been measured for the first time in a virtual-Compton-scattering experiment performed at the MIT-Bates out-of-plane scattering facility. Response functions and polarizabilities obtained from a dispersion analysis of the data at Q(2)=0.057 GeV2/c(2) are in agreement with O(p(3)) heavy baryon chiral perturbation theory. The data support the dominance of mesonic effects in the polarizabilities.

Commercial bioprosthetic heart valves are commonly preserved in glutaraldehyde and are cytotoxic to host cells, preventing spontaneous endothelialization. The aim of this study was to demonstrate the potential for in vivo endothelialization of bioprostheses treated by the L-Hydro process which consists of mild extraction of antigenic substances and incorporation of antiinflammatory and antithrombotic agents. Seven stented porcine heart valves treated by the L-Hydro process and 3 glutaraldehyde-fixed porcine heart valves were implanted in the mitral position in juvenile sheep. The valves were evaluated by echocardiography, angiography, histology, and histochemistry. No hemodynamic differences were observed, but scanning and transmission electron microscopy showed nearly complete coverage by endothelial cells of all leaflets in the L-Hydro-treated valves after 5 months of implantation. The endothelial cells were in direct contact with the underlying collagen and expressed von Willebrand-related antigens. The surfaces of the glutaraldehyde-treated valves were covered by fibrin, macrophages, calcium, and thrombotic material; only sparse endothelial cells were observed and contact with the underlying tissue was incomplete. These data indicate that L-Hydro-treated porcine valves are capable of inducing spontaneous endothelialization.

We report new precise H(e,e(’)p)pi(0) measurements at the Delta(1232) resonance at Q(2)=0.127 (GeV/c)(2) obtained at the MIT-Bates out-of-plane scattering facility which are particularly sensitive to the transverse electric amplitude (E2) of the gamma(*)N–>Delta transition. The new data have been analyzed together with those of earlier measurements to yield precise quadrupole to dipole amplitude ratios: Re(E-1+(3/2)/M-1+(3/2))=(-2.3+/-0.3(stat+syst)+/-0.6(model))% and Re(S-1+(3/2)/M-1+(3/2))=(-6.1+/-0.2(stat+syst)+/-0.5(model))% for M-1+(3/2)=(41.4+/-0.3(stat+syst)+/-0.4(model))(10(-3)/m(pi)(+)). The derived amplitudes give credence to the conjecture of deformation in hadrons favoring, at low Q(2), the dominance of mesonic effects.

Quadrupole amplitudes in the [Formula Presented] transition are associated with the issue of nucleon deformation. A search for these small amplitudes has been the focus of a series of measurements undertaken at Bates/MIT by the OOPS Collaboration. We report on results from [Formula Presented] data obtained at [Formula Presented] and invariant mass of [Formula Presented] using the out-of-plane detection technique with the OOPS spectrometers. The [Formula Presented] and [Formula Presented] response functions were isolated. These results, along with those of previous measurements at [Formula Presented] and [Formula Presented] aim in elucidating the interplay between resonant and nonresonant amplitudes. © 2003 The American Physical Society.

Accurate measurements of the p(→e, e′p)π0 reaction were performed at Q2 = 0.127 (GeV/c)2 in the A resonance energy region. The experiments at the MIT-Bates Linear Accelerator used an 820 MeV polarized electron beam with the out-of-plane magnetic spectrometer system (OOPS). In this Letter we report the first simultaneous determination of both the TL and TL′ ("fifth" or polarized) cross sections at low Q2 where the pion cloud contribution is predicted to dominate the quadrupole amplitudes (E2 and C2). These are the real and imaginary parts of the transverse-longitudinal interference amplitudes and provide a sensitive determination of the Coulomb quadrupole amplitude and a test of reaction calculations. Comparisons with model calculations are presented. The empirical MAID calculation gives the best overall agreement with this accurate data. The parameters of this model for the values of the resonant multipoles are [M1+(I = 3/2)| = (40.9 ± 0.3) × 10-3/mπ, CMR = C2/M1 = -6.5 ± 0.3%, EMR = E2/M1 = -2.2 ± 0.9%, where the errors are due to the experimental uncertainties. © 2003 Elsevier Science B.V. All rights reserved.

We report on the design and performance of compact detector packages currently installed in the four magnetic out-of-plane spectrometers for electron scattering experiments at the MIT-Bates Linear Accelerator Center. The detector packages have been designed to meet the mechanical requirements arising from out-of-plane particle detection. They offer good trajectory and momentum reconstruction, particle identification and time-of-flight measurements for electrons, pions, protons, and deuterons with large momentum bites and in broad kinematical ranges and high luminosities. The detectors have so far been used with great success in out-of-plane measurements of 12C(e→,e′p), 2H(e→,e′p), virtual Compton scattering below pion threshold and in studies of the N→Δ transition in both exclusive reaction channels 1H(e→,e′p)π0 and 1H(e→,e′π+)n. © 2002 Elsevier Science B.V. All rights reserved.

No período de outubro de 1989 a maio de 1997, 40 pacientes portadores de dissecção aórtica, aneurisma da aorta, coarctação da aorta ou doença oclusiva aorto-ilíaca foram submetidos a reconstrução da aorta utilizando-se conduto de pericárdio bovino corrugado processado em glutaraldeído. A reconstrução total da aorta ascendente com substituição da valva aórtica e reimplante das artérias coronárias foi realizada em 9 pacientes, a simples substituição da aorta ascendente em 6, aorta torácica descendente em 2, arco aórtico em 1, aorta toracoabdominal em 1 e a aorta abdominal foi reconstruída em 21, incluindo pacientes submetidos a reconstrução aorto-ilíaca ou aorto-femoral. A mortalidade hospitalar foi de 8 (20%) pacientes e as causas de óbito foram baixo débito cardíaco, recidiva da dissecção aórtica, falência de múltiplos órgãos e sangramento. O seguimento total foi de 128,4 pacientes-anos, com um seguimento médio de 4 anos por paciente. Complicações tardias relacionadas ao conduto vascular foram observadas em 4 pacientes, incluindo obstrução de um dos ramos do tubo bifurcado utilizado para reconstrução aorto-femoral e infecção em 3, resultando em degeneração secundária do conduto e formação de pseudo-aneurisma. Os 4 pacientes foram submetidos a reoperações, correspondendo a uma incidência de 3,1% ± 1,6% por paciente/ano. Ocorreram 5 óbitos tardios e as causas foram morte súbita, doença coronariana, pneumonia, septicemia e complicações metabólicas resultantes de diabetes e insuficiência renal crônica, correspondendo a uma incidência de 3,9% ± 1,7% por paciente/ano. A sobrevida atuarial em 9 anos foi 61,5% ± 9,2%, incluindo a mortalidade cirúrgica e a sobrevida atuarial livre de degeneração tissular estrutural primária do conduto biológico foi de 100%. O corrugamento do pericárdio, resultante da incorporação do princípio crimping utilizado nas próteses vasculares sintéticas, proporciona um conduto circular, que facilita a realização da anastomose, mantém a forma tubular mesmo quando fletido e evita o acotovelamento. O pericárdio é muito macio, fácil de ser manipulado, suturado e coapta muito bem nas linhas de sutura, resultando uma anastomose hemostática. O seguimento de 9 anos demonstrou um desempenho satisfatório deste substituto vascular biológico, não ocorrendo casos de fibrose, calcificação ou dilatação aneurismática.From October 1989 to May 1997, 40 patients with aortic dissection, aortic aneurysm, aortic coarctation or aorto-iliac occlusive disease, underwent reconstruction of their aorta using crimped bovine pericardial conduits processed in glutaraldehyde. Total reconstruction of ascending thoracic aorta and aortic valve with reimplantation of coronary arteries was performed in 9 patients, single ascending thoracic aorta in 6, descending thoracic aorta in 2, aortic arch in 1, thoracoabdominal aorta in 1 and the abdominal aorta was reconstructed in 21, also including patients undergoing aortoiliac or aortofemoral bypass. Hospital mortality was 20% (8 patients) and causes of death were low cardiac output, recurrence of aortic dissection, multiple organ failure and bleeding. Total follow-up was 128.4 patient-years with a mean follow-up of 4 years per patient. Late complications related to the conduit were observed in 4 patients, including a limb obstruction in 1 patient subjected to aorto-femoral bypass and infection in 3, resulting in pseudoaneurysm. All of them underwent reoperations, corresponding to an incidence of 3.1% ± 1.6% per patient-year. There were 5 late deaths and the causes were sudden death, coronary artery disease, pneumonia, septicemia, and metabolic complications of diabetes and renal failure, corresponding to an incidence of 3.9% ± 1.7% per patient-year. The 9-year actuarial survival was 61.5% ± 9.2%, including the surgical mortality, and the 9-year actuarial freedom from conduit failure due to primary tissue structural degeneration was 100%. The crimping design, similar to that used for synthetic vascular prosthesis, provides a circular tube which makes the construction of the anastomosis easier, retains its shape with bending and avoids kinking. The pericardium is very soft, easy to handle and suture, coapts nicely to suture lines resulting in a hemostatic anastomosis. The 9-year follow-up demonstrated a satisfactory performance, without any evidence of fibrosis, calcification or aneurysmal dilatation.

A rotura de parede livre do ventrículo esquerdo (VE) e a comunicação interventricular (CIV) por rotura de septo são dois eventos catastróficos que podem complicar a evolução do infarto agudo do miocárdio (IAM). A oportunidade do tratamento cirúrgico, o acesso à CIV e a técnica cirúrgica ideal para o tratamento desta complicação são muito discutidos na literatura (1-5). Os resultados, porém, são quase unânimes: alta taxa de mortalidade. A rotura da parede posterior do ventrículo esquerdo pós troca da valva mitral (disjunção atrioventricular) não é uma complicação rara, sendo quase sempre fatal (6, 7). O objetivo de nosso trabalho é discutir a alternativa de tratamento cirúrgico destas graves lesões, sem o manuseio direto do músculo cardíaco friável, necrozado. Desenvolvemos e testamos em animais (carneiros) o dispositivo de isolamento ventricular (DIV). No período de 12/7/95 a 10/1/96, operamos 12 carneiros adultos para o implante do DIV. No primeiro período de aprendizado da técnica de implante e de desenvolvimento da prótese, operamos 7 animais, sem sucesso. No segundo período operamos 5 animais, já com o DIV completamente desenvolvido e com a técnica cirúrgica já padronizada; obtivemos sucesso com todos os animais, sobrevivendo com bom débito cardíaco, constatado ao ecocardiograma e à ventriculografia. Após 20 dias de sobrevida, os animais foram submetidos a ventriculografia e ecocardiografia. Observamos o completo isolamento da cavidade ventricular com o emprego do DIV, obtendo o tratamento provisório destas graves lesões.The rupture of the ventricular free wall, and the ventricular septal rupture are two catastrophic events that can complicate the outcome of acute myocardial infarction. The opportunity to use surgical treatment, the access to the ventricular septal rupture as well as the ideal surgical technique are very much discussed in the literature but the results are almost unanimous: an elevated mortality. The rupture of the posterior wall of the left ventricle after mitral valve replacement is not a rare complication and it is almost always fatal. Our objective is to discuss a new alternative for surgical treatment of those serious pathologies without the direct handling of the necrotic cardiac muscle. We developed and tested in animals (sheeps) the Ventricular Isolation Device. From 7/12/95 to 1/10/96, we implanted this device in 12 adult sheeps. During the first period of learning the surgical technique and developing the device, we operated on 7 animals, without success. On a second turn, we performed the procedure in 5 animals and by then the Ventricular Isolation Device was completely developed and the surgical technique already standardized, resulting in the survival of all animals with normal cardiac output, as shown by echocardiography and ventriculography. We observed the complet isolation of the ventricular cavity with the use of Ventricular Isolation Device and obtained the temporary treatment of those fatal pathologies.

The publication since the middle 1970s of scholarly editions of Hardy’s letters, notebooks, and autobiography, as well as of critical editions of his poems and certain of his novels, makes possible a closer look than before into Hardy’s day-to-day life as a working writer, particularly his sense of his readers and the effect of their responses on his writing.2 For the student of Hardy’s creative process, these documents reveal three important shifts in his sixty years of professional writing. Each shift was a clear response to readers’ tastes and opinions, and each marked a turning point in his career as novelist and poet. Furthermore, each revealed Hardy’s continuing need to mediate between two kinds of novelty: what in 1868 he termed ‘novelty of position and view in relation to a known subject’ and ‘absolute novelty of subject’.3

To Kill the Voice? To make it recede, at least into a ‘presque disparition vibratoire’ a Mallarmean or diacritical poetics. Or to have the notion of the author — and with it, possibly, of authority — disappear. No wonder that obverse simplifications assert themselves: on the one hand, the insistence that there is no meaning without a certifiable authorial intention; and, on the other, that there is no authority except by imposition. There is also the device of shifting much of the burden onto a reader who now becomes a co-author, as in the recent revival of Rezeptionsgeschichte on a structural basis. I am myself guilty of simplifying here, but I wish to suggest how troubled the contemporary spectrum of aesthetic theories is by the often unacknowledged issue of literary or spiritual authority. (Geoffrey Hartman, ‘The Fate of Reading’, 1975)

Near-surface sediments of the Black Sea were found to contain a wide variety of tetrapyrrole pigments; significant quantities occur in homologous series closely related to petroporphyrins. The homologous series of pigments had each homolog differing by 14 amu. Within a sediment sample a number of homologous series were observed: 1. (1) one containing mass 476 (DPEP series); 2. (2) another containing mass 478 (Etio series); and 3. (3) a series having homologs above mass 600. Spectrally, the tetrapyrroles appeared to contain significant proportions of chlorins, indicating that some of the compounds may be dihydro DPEP and associated homologous members.

The peat-forming systems of the Okefenokee Swamp are viewed as modern progenitors of coal. Taxodium and Nymphaea-derived peat-forming systems were characterized in terms of (1) organic fractions and (2) the distribution of organic/inorganic sulfur in each organic fraction (water soluble, benzene/methanol soluble, humin, humic acid, fulvic acid). The humin fraction is the largest organic fraction in both environments, approaching 70% of the total organic matter in the Nymphaea-derived environment. Humin origins are discussed in terms of a humic acid precursor, and undecomposed plant material. It is suggested that each depth of peat represents a diagenetic history of events which the authors believe occurred primarily when the currently buried peat was at the surface. The sulfur content of both peat-forming areas is low (0.23–0.27%); organic sulfur is the dominant sulfur form. Humin contains 50–80% of the total sulfur and of this, 80% is organic sulfur. Ester-sulfate appears to be especially prevalent in the fulvic acid fraction. The sulfur content of freshwater-derived peats is similar in quantity and distribution to that found in low sulfur coals.

Six sulfur forms were investigated in profiles of freshwater- and marine-derived peat-forming systems of the Okefenokee Swamp, Georgia and Everglades Swamp, Florida. Total sulfur levels of 0.1–10% were found, thus indicating a major incorporation of sulfur in the very early stages of coal formation. The quantities of hydrogen sulfide and elemental sulfur observed appeared to be indicative of whether marine or freshwater conditions prevailed at the site of deposition. Carbon-bonded sulfur accounted for 70% of the total sulfur in the freshwater peat and 50% of the total sulfur in the marine peat. Over 15% of the total sulfur was in pyritic combination in the marine environment, while levels of pyrite in the freshwater peats were an order of magnitude lower. An ester-sulfate fraction represented 25% of the total sulfur in both freshwater and marine peats. The levels of sulfur forms in the peat profiles are compared to those observed in living plants and to various coals; levels of pyrite and organic sulfur in the peat are similar to those found by other investigators in freshwater-derived and marine-derived coals.

Ba, Ca, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, Pb and Zn were studied in cores of peat from two major vegetational areas of the Okefenokee Swamp, Georgia; both total peat and organic fractions were investigated. Except for Hg and Pb, metal concentrations were either higher or equal to Clarke values. The sandy bedrock is not an important contributor to metal concentrations found in peat. Levels of metals in a given peat sample were related to plant materials which gave rise to the peat; it does not appear that vegetational environment plays a critical role in determining trace metal distribution, but does play a role in determining the amount of humic or pre-vitrinitic constituents that eventually are found in coal.

Distributions of amino acids in some Florida peats have been compared with distributions in plants living now at the surface of the peats and in surface litter. Quantitative determinations were made by gas chromatography of volatile derivatives of both protein and non-protein amino acids. The latter. found also in mineral soils, are believed to represent bacterial cell constituents and/or anabolites. α,ϵ-diaminopimelic acid, a constituent of the mureide complex of bacterial cell walls, was found in peats and surface litter, as were other acids believed in soil ecosystems to result from the living processes of microorganisms. The protein amino acids in peats do not show a distinctive signature of any particular kind of organism, but the nature and concentrations of the non-protein acids support the inference that the higher plant constituents are extensively re-worked and that essentially all of the amino acid material in peats is microbial in proximate origin. Thus microbial amino acids appear to be quite significant participants in the input to coalification.

Amino acids have been isolated from peats and fractions thereof at two sites in different environments in the Florida Everglades. For comparison, amino acids were also obtained by hydrolysis of organs of the plants now providing the surface cover at the sites and of discarded plant parts in surface litter. The amino acids, including a number of non-protein acids, were analyzed by GLC of volatile derivatives. There is a marked tendency for the total amino acid concentrations to increase in the order plant material

Crude oils generally contain at least one symmetrical homologous series of porphyrins, which is usually centered at m/e 476 (DPEP) or m/e 478 (etioporphyrin). Simulated geochemical conditions in the present study resulted in decarboxylations and alkylations which ultimately led to the synthesis of homologous porphyrins from a single porphyrin. In several series of closed tube experiments, mesoporphyrin IX dimethylester (MPDME) was mixed with a variety of constituents including benzene, acetic acid, propionic acid, water and clay; the experiments were performed at temperatures between 135°C and 400°C at time intervals up to 80 days. Dealkylation, alkylation, hydrolysis, decarboxylation and metallation products were observed. An unsymmetrical homologous series of porphyrins was produced from MPDME. The dominant mass was m/e 478 (corresponding to a double deoarboxylation). Dealkylation products in multiples of 14 amu below the m/e 478 peak comprised the other members of the series. Cu-MPDME also produced homologous porphyrins. These, however, exhibited symmetry about the dominant members, similar to the symmetry found for the porphyrins of most petroleums and oil shales.