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1.
J Environ Manage ; 314: 115021, 2022 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-35483277

RESUMEN

The UK food system is reliant on imported phosphorus (P) to meet food production demand, though inefficient use and poor stewardship means P is currently accumulating in agricultural soils, wasted or lost with detrimental impacts on aquatic environments. This study presents the results of a detailed P Substance Flow Analysis for the UK food system in 2018, developed in collaboration with industry and government, with the key objective of highlighting priority areas for system interventions to improve the sustainability and resilience of P use in the UK food system. In 2018 the UK food system imported 174.6 Gg P, producing food and exportable commodities containing 74.3 Gg P, a P efficiency of only 43%. Three key system hotspots for P inefficiency were identified: Agricultural soil surplus and accumulation (89.2 Gg P), loss to aquatic environments (26.2 Gg P), and waste disposal to landfill and construction (21.8 Gg P). Greatest soil P accumulation occurred in grassland agriculture (85% of total accumulation), driven by loadings of livestock manures. Waste water treatment (12.5 Gg P) and agriculture (8.38 Gg P) account for most P lost to water, and incineration ashes from food system waste (20.3 Gg P) accounted for nearly all P lost to landfill and construction. New strategies and policy to improve the handling and recovery of P from manures, biosolids and food system waste are therefore necessary to improve system P efficiency and reduce P accumulation and losses, though critically, only if they effectively replace imported mineral P fertilisers.


Asunto(s)
Fertilizantes , Fósforo , Agricultura , Estiércol , Fósforo/análisis , Suelo , Reino Unido
2.
Philos Trans A Math Phys Eng Sci ; 372(2008): 20120036, 2014 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-24379426

RESUMEN

Zeolites are microporous crystalline aluminosilicate materials whose atomic structures can be usefully modelled in purely mechanical terms as stress-free periodic trusses constructed from rigid corner-connected SiO4 and AlO4 tetrahedra. When modelled this way, all of the known synthesized zeolite frameworks exhibit a range of densities, known as the flexibility window, over which they satisfy the framework mechanical constraints. Within the flexibility window internal stresses are accommodated by force-free coordinated rotations of the tetrahedra about their apices (oxygen atoms). We use rigidity theory to explore the folding mechanisms within the flexibility window, and derive an expression for the configurational entropic density throughout the flexibility window. By comparison with the structures of pure silica zeolite materials, we conclude that configurational entropy associated with the flexibility modes is not a dominant thermodynamic term in most bulk zeolite crystals. Nevertheless, the presence of a flexibility window in an idealized hypothetical tetrahedral framework may be thermodynamically important at the nucleation stage of zeolite formation, suggesting that flexibility is a strong indicator that the topology is realizable as a zeolite. Only a small fraction of the vast number of hypothetical zeolites that are known exhibit flexibility. The absence of a flexibility window may explain why so few hypothetical frameworks are realized in nature.

3.
J Bone Miner Res ; 14(6): 1003-12, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10352110

RESUMEN

Urinary prothrombin fragment 1 (UPTF1) is the principal protein in calcium oxalate (CaOx) crystals precipitated from human urine and is a potent inhibitor of CaOx crystallization, a property that should depend, at least in part, upon the extent of gamma-carboxylation of the 10 glutamic residues in its N-terminal region. Warfarin therapy limits full gamma-carboxylation of vitamin K-dependent proteins, including UPTF1. The aims of this study were to determine the effect of warfarin therapy on UPTF1, its occlusion into CaOx urinary crystals, and its influence on the crystallization of CaOx in undiluted human urine. In the first part of the study, urines were collected from six men prior to cardiac surgery and after stabilization on long-term warfarin treatment. Proteins in the urines and in the matrix of CaOx crystals precipitated from them were analyzed by two-dimensional SDS-PAGE and Western blotting. In urine, at least two charge variants of UPTF1 with low isoelectric point (pI) values were detected before and during warfarin therapy, but additional higher pI forms of the protein were also seen during anticoagulation. Nonetheless, the majority of UPTF1 was present in the more fully gamma-carboxylated state. CaOx crystals precipitated from the same urine samples contained only low pI forms of UPTF1. The effect of warfarin treatment on CaOx crystallization in urine was tested by collecting two consecutive 24-h urine samples from 16 men prior to cardiac surgery and during subsequent warfarin treatment. CaOx crystallization was induced in each sample by the addition of sodium oxalate. The size and volume of the particles deposited were determined using a Coulter counter, and the crystals were examined by scanning electron microscopy (SEM). There were no significant differences between the urinary metastable limits before or during warfarin treatment or in the total volume of crystals precipitated. A slight increase in the mean diameter of the crystalline particles precipitated from the urines during anticoagulant therapy was not significant. SEM showed little evidence of changes in overall particle size, although individual crystals of CaOx tended to be larger during warfarin treatment. It was concluded from these studies that the binding of UPTF1 to CaOx crystal surfaces is related to the degree of gamma-carboxylation of its Gla domain, which would also influence the protein's inhibitory effects on CaOx crystallization. However, during warfarin therapy the majority of UPTF1 exists in a highly charged state, indicating that it is completely, or almost completely, gamma-carboxylated, which would explain the lack of any difference between CaOx crystallization parameters in the urine of subjects before and during warfarin administration. We conclude that physiologically significant reductions in the inhibitory potency of UPTF1 would be likely to occur only as a result of proscription of gamma-carboxylation more extensive than that induced by warfarin.


Asunto(s)
Anticoagulantes/uso terapéutico , Oxalato de Calcio/orina , Fragmentos de Péptidos/orina , Precursores de Proteínas/orina , Protrombina/orina , Warfarina/uso terapéutico , Adulto , Anciano , Western Blotting , Cristalización , Humanos , Masculino , Persona de Mediana Edad , Cuidados Preoperatorios/métodos , Estudios Retrospectivos
4.
Appl Nurs Res ; 11(4): 174-82, 1998 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9852660

RESUMEN

Split-thickness skin grafting (STSG) is a frequently used reconstructive technique but is associated with a large variation in practice. The purposes of this article are to integrate and synthesize the available empirical evidence regarding STSG donor site dressings, identify which dressings are associated with the best outcomes, and provide practice recommendations. This review of 33 studies found transparent film to be the best dressing for the care of STSG donor site wounds. Transparent film was associated with one of the fastest healing rates (9.47 days), a smooth epithelialized surface, a low infection rate (10 out of 394 patients or 3%), the least amount of pain (1.59 on 0 to 10 scale), and minimal cost ($.005 per square inch) when compared with other dressings.


Asunto(s)
Vendajes/normas , Medicina Basada en la Evidencia , Investigación en Enfermería , Cuidados Posoperatorios/métodos , Cuidados de la Piel/métodos , Trasplante de Piel , Vendajes/efectos adversos , Vendajes/clasificación , Vendajes/economía , Humanos , Dolor Postoperatorio/prevención & control , Cuidados Posoperatorios/enfermería , Cuidados de la Piel/enfermería , Infección de la Herida Quirúrgica/prevención & control , Resultado del Tratamiento , Cicatrización de Heridas
5.
Clin Sci (Lond) ; 95(2): 187-93, 1998 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9680501

RESUMEN

1. A broad spectrum of proteins has been detected within calcium stones. A newcomer to the field of urolithiasis is the blood protein inter-alpha-inhibitor. Inter-alpha-inhibitor comprises three protein chains linked by chondroitin sulphate: two heavy chains, H1 (65 kDa) and H2 (70 kDa) and a light chain (approx. 30 kDa) most commonly known as bikunin. The physiological function of the two heavy chains is unknown; nor has their presence been reported in urine. However, bikunin has been implicated in various renal diseases, including urolithiasis. 2. This study was undertaken to determine which chains of inter-alpha-inhibitor are actually present in calcium kidney stones. Organic extracts were obtained from 10 calcium stones and analysed by SDS/PAGE and Western blotting. The H1 and H2 chains of inter-alpha-inhibitor were detected in 9 of the 10 stones, but only one stone contained a protein with a molecular mass close to that of bikunin (30-35 kDa). 3. These results demonstrate for the first time that H1 and H2 are present in stones and show that the bikunin chain of inter-alpha-inhibitor may not be the only part of the molecule implicated in stone formation.


Asunto(s)
alfa-Globulinas/análisis , Cálculos Renales/química , Inhibidores de Serina Proteinasa/análisis , Inhibidores de Tripsina/análisis , Adulto , Anciano , alfa-Globulinas/química , Western Blotting , Electroforesis en Gel de Poliacrilamida , Femenino , Humanos , Masculino , Persona de Mediana Edad , Conformación Proteica , Inhibidores de Serina Proteinasa/química , Inhibidores de Tripsina/química
6.
Otolaryngol Head Neck Surg ; 118(2): 211-20, 1998 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9482555

RESUMEN

The objectives of this study were to investigate potential relationships between pretreatment patient-mix characteristics, treatment modalities, and costs generated during the pretreatment work-up, treatment, and 1-year follow-up periods for patients with oral cavity cancer (OCC). Another objective was to identify potential areas for cost reduction and improved resource allocation in the management of OCC patients. Using a retrospective cohort of 73 patients with OCC, pretreatment patient-mix characteristics and treatment modalities were evaluated in relation to university-based charges incurred during the pretreatment evaluation, treatment, and 1-year follow-up periods. Simple regression and stepwise multiple regression analyses were used to develop predictive models for cost based on independent variables, including age, AJCC TNM clinical stage, smoking history, American Society of Anesthesiologists (ASA) class, comorbidity as defined by the Kaplan-Feinstein grade and treatment modality. The dependent measurements included all physician, office, and hospital charges incurred at the University of Iowa Hospitals and Clinics during the pretreatment evaluation, treatment, and follow-up periods, as well as the total pretreatment through 1-year follow-up management costs. Independent variables that were identified as being significantly associated with treatment costs included T classification, N classification, TNM stage, unimodality versus multimodality treatment, and the Kaplan-Feinstein comorbidity grade. Age, smoking status, and ASA class were not significantly associated with costs. The majority of the OCC management costs were incurred during the treatment period. The most substantial decreases in management costs for OCC will be realized through measures that allow identification and treatment of disease at an early stage, in which single-modality treatment may effectively be used. Resource allocation for OCC should support the investigation of measures through which the diagnosis and treatment of OCC at the earliest possible stage is facilitated. The presence of comorbid illness is a significant component in the determination of management costs for OCC and should be included in analyses of resource allocation for OCC. The singular diagnosis of OCC encompasses a wide range of patient illness severity, and diagnosis-related reimbursement schemes for OCC treatment should optimally differentiate between early and advanced stage disease.


Asunto(s)
Carcinoma de Células Escamosas/economía , Carcinoma de Células Escamosas/terapia , Costos de la Atención en Salud , Neoplasias Orofaríngeas/economía , Neoplasias Orofaríngeas/terapia , Anciano , Carcinoma de Células Escamosas/complicaciones , Carcinoma de Células Escamosas/mortalidad , Terapia Combinada/economía , Costos y Análisis de Costo , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasias Orofaríngeas/complicaciones , Neoplasias Orofaríngeas/mortalidad , Estudios Retrospectivos , Tasa de Supervivencia , Tabaquismo/complicaciones
7.
Br J Urol ; 81(1): 20-6, 1998 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9467471

RESUMEN

OBJECTIVE: To determine which chains of inter-alpha-inhibitor (I alpha I) are present in urine and whether they are also found in calcium oxalate (CaOx) crystals generated in human urine. MATERIALS AND METHODS: Fresh urine specimens were collected from five women and five men with no previous history of stone disease. An aliquot of each urine was retained for analysis, the remainder treated with a standard load of oxalate and the CaOx crystals precipitated from each specimen demineralized with ethylenediamine tetracetic acid. The resulting organic extracts from crystals and their corresponding urine samples were subjected to sodium dodecyl sulphate gel electrophoresis analysis and Western blotting using a commercial polyclonal antibody to I alpha I. RESULTS: Heavy chain 1 (H1) and 2 (H2) of I alpha I were commonly found in every urine sample, and in the CaOx crystals precipitated from those urine samples. Several protein bands were visible in urine samples from both sexes in the molecular mass range 25-70 kDa, which may be bikunin or its fragments. As well as H1 and H2, the crystals from both sexes contained a protein band at approximately 33 kDa. In many cases there appeared to be no direct relationship between the proteins detected in the crystals and the urine samples from which they were derived, which probably reflects the well known instability of I alpha I and the occurrence of a range of bikunin fragments in urine. CONCLUSION: These results show for the first time that H1 and H2 are present in human urine and urinary CaOx crystals, that the bikunin chain of I alpha I is not the only part of the molecule capable of participating in CaOx crystallization in urine, and in theory at least, in the regulation of crystallization events in stone formation. It is also apparent that significant fragmentation of I alpha I occurs both in vivo and in vitro, and this must be considered in any study attempting to elucidate the influence of this protein in the formation of CaOx stones.


Asunto(s)
alfa-Globulinas/orina , Oxalato de Calcio/orina , Inhibidores de Serina Proteinasa/orina , Adulto , Western Blotting , Oxalato de Calcio/química , Cristalización , Femenino , Humanos , Masculino , Persona de Mediana Edad
8.
Head Neck ; 19(8): 675-83, 1997 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9406746

RESUMEN

BACKGROUND: It is a common perception that the overall health of patients with head and neck cancer (HNC) is likely to be poor compared with the general population. This project was undertaken to investigate the pre- and post-treatment, global health status of HNC patients in comparison with age-matched, U.S. population norms using a self-administered general health status survey. METHODS: Between July 1, 1993, and May 1, 1996, 180 patients underwent pretreatment and 6 month follow-up evaluation with the standard version of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). The SF-36 scale scores, means, standard deviations, and 95% confidence intervals were calculated for each SF-36 scale as well as for physical-health-component summary scores (PCS) and mental-health-component summary scores (MCS). Comparisons of these scores were made to U.S. population normative data. Pretreatment and 6-month follow-up SF-36 scores were compared. RESULTS: In the 45-54-year age group, all 8 SF-36 scale scores, the PCS, and MCS scores were significantly worse for the HNC patients in comparison with age-matched norms (p < .05). In the 55-64-year age group, the HNC patients were worse in 5 of the 8 SF-36 scale scores and the MCS score in comparison with age-matched norms (p < .05). In the 65-74-year age group, the HNC patients scored significantly worse in the mental health scale. In the comparison of pretreatment and 6-month follow-up scores, the HNC patients had significant decreases in the physical functioning scale (p = .003) and the PCS score (p = .047). The HNC patients showed significant improvement in the mental health scale (p = .049) and improvement in the bodily-pain scale, which approached significance (p = .053) at 6-month follow-up. The HNC patients showed a marked decrease in general health status with increasing stage of HNC. CONCLUSIONS: This work provides objective support for the perception that many HNC patients are initially seen for treatment with baseline health status functioning significantly below their age-matched contemporaries in the general population. An educated evaluation of global health outcomes following treatment in the HNC patient population must begin with an accurate pretreatment assessment of these parameters. Self-reported health-status assessment (HSA) is a useful means of evaluating global health status in this patient population.


Asunto(s)
Neoplasias de Cabeza y Cuello , Estado de Salud , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Neoplasias de Cabeza y Cuello/complicaciones , Neoplasias de Cabeza y Cuello/terapia , Humanos , Persona de Mediana Edad , Valores de Referencia , Estados Unidos
10.
Kidney Int ; 49(3): 880-8, 1996 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8648933

RESUMEN

The fact that organic material is always present and distributed throughout each renal calculus suggests that it may play a role in stone formation. The organic matrix of calcium oxalate (CaOx) crystals freshly generated in urine in vitro contains urinary prothrombin fragment 1 (UPTF1) as the principal protein. In this initial study, matrix was extracted from 12 renal calculi and evaluated for the presence of UPTF1 using Western blotting. UPTF1 was present in all eight stones whose principal component was CaOx, and in one of two stones which consisted mainly of calcium phosphate (CaP). UPTF1 was absent from the two struvite calculi examined. The relationship between CaP and UPTF1 was explored further. Matrix harvested from CaP crystals freshly generated in urine in vitro was also shown to contain UPTF1 as its principal component. Our inability to detect UPTF1 in one mixed CaOx/CaP stone may be related to our methods of matrix retrieval, while its absence from two struvite stones argues against it being present in the other stones merely as a consequence of passive inclusion. This absence may be related to the alkaline environment typical of struvite stone growth. The finding that UPTF1 is present in some renal stones provides the first direct evidence that links blood coagulation proteins with urolithiasis.


Asunto(s)
Coagulación Sanguínea/fisiología , Fragmentos de Péptidos/análisis , Precursores de Proteínas/análisis , Protrombina/análisis , Cálculos Urinarios/química , Adulto , Anciano , Anticuerpos Monoclonales , Western Blotting , Fosfatos de Calcio/análisis , Fosfatos de Calcio/inmunología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fragmentos de Péptidos/inmunología , Precursores de Proteínas/inmunología , Proteínas/análisis , Protrombina/inmunología , Cálculos Urinarios/sangre
11.
ORL Head Neck Nurs ; 14(4): 15-7, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-8970337

RESUMEN

Diarrhea following tube feedings in postoperative head and neck oncology patients is a significant problem. The existing tube feeding protocol was evaluated and clarified. A study was also undertaken to reduce the incidence of diarrhea in this patient population.


Asunto(s)
Nutrición Enteral/enfermería , Planificación de Atención al Paciente , Diarrea/etiología , Diarrea/prevención & control , Nutrición Enteral/efectos adversos , Nutrición Enteral/métodos , Neoplasias de Cabeza y Cuello/cirugía , Humanos
12.
Urol Res ; 23(1): 53-62, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-7618236

RESUMEN

Demineralization of calcium oxalate (CaOx) crystals precipitated from human urine in vitro yields an organic crystal matrix extract (CME) consisting predominantly of a single protein which we originally named crystal matrix protein but have subsequently shown to be a urinary form of prothrombin activation peptide fragment 1 (F1). The aim of this study was to determine whether CME is a promoter or inhibitor of CaOx crystallization. The effect of CME on CaOx crystal growth and aggregation was tested using a standard seeded crystallization system, and its effect quantified by use of particle size analysis and a computer model. In addition, the effect of CME on the crystallization of CaOx was tested in undiluted, ultrafiltered human urine using Coulter Counter analysis and scanning electron microscopy. It was shown that CME is a potent inhibitor of CaOx crystal growth and aggregation in a seeded metastable solution. However, of greater significance is that at a concentration of 10 mg/l it completely reversed the formation of large crystalline aggregates that form upon the removal of urinary macromolecules from undiluted urine. It was concluded that CME is the most potent macromolecular urinary inhibitor yet to be tested in urine in vitro. By preventing the aggregation of newly formed crystals, the components of CME may significantly reduce the probability of particle retention in vivo and therefore the occurrence of urolithiasis.


Asunto(s)
Oxalato de Calcio/orina , Cristalización , Humanos
13.
N Z Med J ; 95(716): 663-6, 1982 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-6813780

RESUMEN

Intravenous nitroglycerin (IVNG) was used in 12 instances (11 patients) to relieve pain, following myocardial infarction or unstable angina. The strength of IVNG infusion could be easily controlled and relief of pain was prompt and satisfactory. Excessive tachycardia or severe headache was not encountered and marked hypotension was seen in one patient only. This patient had three vessel coronary artery disease, extensive myocardial damage and vein graft closure. Cardiovascular stability was provided by IVNG, prior to and during cardiac catheterisation and cineangiography, transportation to another hospital and vein graft surgery. IVNG appears to be a safe and effective drug in the management of patients with acute coronary artery disease (unstable angina and myocardial infarction). In those with both right and left ventricular wall infarction, however, the usefulness of IVNG needs to be established.


Asunto(s)
Angina de Pecho/tratamiento farmacológico , Infarto del Miocardio/tratamiento farmacológico , Nitroglicerina/administración & dosificación , Enfermedad Aguda , Adulto , Anciano , Femenino , Humanos , Infusiones Parenterales , Masculino , Persona de Mediana Edad , Nitroglicerina/uso terapéutico
14.
J Lipid Res ; 17(6): 565-71, 1976 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1033261

RESUMEN

The sterol content of two Myxomycetes, Physarum polycephalum and P. flavicomum has been examined. The sterols of the two species are apparently identical, the two major sterols in each being poriferasterol and 22-dihydroporiferasterol. Threee minor sterols are probably delta5-ergostenol, ergostanol, and poriferastanol. The triterpenoids of the two species differ in that, though lanosterol was identified in both, 22-dihydrolanosterol was indicated only in P. flavicomum. The occurrence of lanosterol together with a typical mixture of plant sterols is somewhat unusual.


Asunto(s)
Mixomicetos/análisis , Physarum/análisis , Esteroles/análisis , Cromatografía de Gases , Lanosterol/análisis , Especificidad de la Especie , Terpenos/análisis
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