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1.
BMC Palliat Care ; 21(1): 7, 2022 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-34996428

RESUMEN

BACKGROUND: In acute-care hospitals, patients treated in an ICU for surgical reasons or sudden deterioration are treated in an outpatient ward, ICU, and other multiple departments. It is unclear how healthcare providers are initiating advance care planning (ACP) for such patients and assisting them with it. The purpose of this study is to clarify healthcare providers' perceptions of the ACP support provided to patients receiving critical care in acute-care hospitals. METHODS: A cross-sectional study was conducted using questionnaires. In this study, 400 acute-care hospitals with ICUs in Japan were randomly selected, and 1490 subjects, including intensivists, surgeons, ICU nurses, surgical floor nurses, and surgical outpatient nurses, participated. Survey items examined whether ICU patients received ACP support, the participants' degree of confidence in providing ACP support, the patients' treatment preferences, and the decision-making process, and whether any discussion was conducted on change of values. RESULTS: Responses were obtained from 598 participants from 157 hospitals, 41.4% of which reportedly supported ACP provision to ICU patients. The subjects with the highest level of ACP understanding were surgeons (45.8%), and differences in understanding were observed across specialties (P < 0.001). Among the respondents, physicians and nurses expressed high levels of confidence in providing ACP support to patients requiring critical care. However, 15.2% of all the subjects mentioned that they would not attempt to resuscitate the patients. In addition, 25.7% of the participants handed over patients' values to other departments or hospitals, whereas 25.3% handed over the decision-making process. CONCLUSIONS: Among the participating hospitals, 40% provided ACP support to patients receiving critical care. The low number is possibly because support providers lack understanding of the content of patients' ACP or about how to support and use ACP. Second, it is sometimes too late to start providing ACP support after ICU admission. Third, healthcare providers differ in their perception of ACP, widely considered an ambiguous concept. Finally, in acute-care hospitals with different healthcare settings, it is necessary to confirm and integrate the changes in feelings and thoughts of patients.


Asunto(s)
Planificación Anticipada de Atención , Enfermedad Crítica , Estudios Transversales , Personal de Salud , Hospitales , Humanos , Percepción
2.
BMC Palliat Care ; 21(1): 179, 2022 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-36224540

RESUMEN

BACKGROUND: Patients undergoing high-risk surgery are at a risk of sudden deterioration of their health. This study aimed to examine the feasibility of the development of two patient decision aids (PtDAs) to assist patients undergoing high-risk surgeries in informed decision-making about their medical care in a crisis. METHODS: This field testing implemented two PtDAs that met the international criteria developed by the researchers for patients before surgery. Study participants were patients scheduled to be admitted to the intensive care unit after surgery at one acute care hospital in Japan and their families. The study used a mixed-methods approach. The primary outcome was patients' decision satisfaction evaluated by the SURE test. Secondary outcomes were the perception of the need to discuss advance care planning (ACP) before surgery and mental health status. The families were also surveyed on their confidence in proxy decision-making (NRS: 0-10, quantitative data). In addition, interviews were conducted after discharge to assess the acceptability of PtDAs. Data were collected before (preoperative outpatients, baseline: T0) and after providing PtDAs (in the hospital: T1) and following discharge (T2, T3). RESULTS: Nine patients were enrolled, of whom seven agreed to participate (including their families). The SURE test scores (mean ± SD) were 2.1 ± 1.2 (T0), 3.4 ± 0.8 (T2), and 3.9 ± 0.4 (T3). The need to discuss ACP before surgery was 8.7 ± 1.3 (T1) and 9.1 ± 0.9 (T2). The degree of confidence in family surrogate decision-making was 6.1 ± 2.5 (T0), 7.7 ± 1.4 (T1), and 8.1 ± 1.5 (T2). The patients reported that using PtDAs provided an opportunity to share their thoughts with their families and inspired them to start mapping their life plans. Additionally, patients wanted to share and discuss their decision-making process with medical professionals after the surgery. CONCLUSIONS: PtDAs supporting ACP in patients undergoing high-risk surgery were developed, evaluated, and accepted. However, they did not involve any discussion of patients' ACP treatment wishes with their families. Medical providers should be coached to provide adequate support to patients. In the future, larger studies evaluating the effectiveness of PtDAs are necessary.


Asunto(s)
Planificación Anticipada de Atención , Técnicas de Apoyo para la Decisión , Directivas Anticipadas , Humanos , Satisfacción del Paciente , Apoderado , Procedimientos Quirúrgicos Operativos
3.
Proc Natl Acad Sci U S A ; 111(10): E914-23, 2014 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-24567380

RESUMEN

Radiation dose rates were evaluated in three areas neighboring a restricted area within a 20- to 50-km radius of the Fukushima Daiichi Nuclear Power Plant in August-September 2012 and projected to 2022 and 2062. Study participants wore personal dosimeters measuring external dose equivalents, almost entirely from deposited radionuclides (groundshine). External dose rate equivalents owing to the accident averaged 1.03, 2.75, and 1.66 mSv/y in the village of Kawauchi, the Tamano area of Soma, and the Haramachi area of Minamisoma, respectively. Internal dose rates estimated from dietary intake of radiocesium averaged 0.0058, 0.019, and 0.0088 mSv/y in Kawauchi, Tamano, and Haramachi, respectively. Dose rates from inhalation of resuspended radiocesium were lower than 0.001 mSv/y. In 2012, the average annual doses from radiocesium were close to the average background radiation exposure (2 mSv/y) in Japan. Accounting only for the physical decay of radiocesium, mean annual dose rates in 2022 were estimated as 0.31, 0.87, and 0.53 mSv/y in Kawauchi, Tamano, and Haramachi, respectively. The simple and conservative estimates are comparable with variations in the background dose, and unlikely to exceed the ordinary permissible dose rate (1 mSv/y) for the majority of the Fukushima population. Health risk assessment indicates that post-2012 doses will increase lifetime solid cancer, leukemia, and breast cancer incidences by 1.06%, 0.03% and 0.28% respectively, in Tamano. This assessment was derived from short-term observation with uncertainties and did not evaluate the first-year dose and radioiodine exposure. Nevertheless, this estimate provides perspective on the long-term radiation exposure levels in the three regions.


Asunto(s)
Radioisótopos de Cesio/análisis , Exposición a Riesgos Ambientales/análisis , Accidente Nuclear de Fukushima , Neoplasias/epidemiología , Dosis de Radiación , Monitoreo de Radiación/estadística & datos numéricos , Predicción , Geografía , Humanos , Japón/epidemiología , Factores de Riesgo
4.
Cureus ; 16(2): e54175, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38496091

RESUMEN

INTRODUCTION: Efforts to enhance support for advance care planning (ACP) in patients requiring emergency and intensive care are currently being explored. In addition, few studies have reported the effects and impact of support for these patients and their families. The researcher developed a patient decision aid to initiate support for ACP for patients who plan to enter the intensive care unit after surgery and their families. This study aimed to provide ACP support to patients before high-risk surgery and to determine its impact. METHODS: The study design was qualitative. The participants included 10 patients who were scheduled to be admitted to the intensive care unit after high-risk surgery at an acute-care hospital in Japan, and the patients' families. The researcher used decision aids to implement ACP support before the patients were admitted. Participants were interviewed in a semi-structured manner regarding their experiences and the impact of receiving ACP support after discharge. Interviews were recorded using an integrated circuit recorder, followed by verbatim transcripts. The analysis was performed in a qualitative descriptive manner. RESULTS: ACP support prior to treatment initiation led patients to think about life-sustaining treatments and consider ideal living. By understanding the risks of treatment, patients can calmly assume complications and discuss their mortality and life after surgery. Patients perceived receiving ACP support as a valuable benefit prior to undergoing treatment in the intensive care unit. After discharge, they wanted to promote shared decision-making among their physicians. On the other hand, family members were more anxious about ACP topics than patients. In addition, the patients and their families felt that it was difficult to discuss their thoughts and wishes regarding ACP before surgery. CONCLUSION: It is suggested that pretreatment ACP support could serve as an introductory phase for patients anticipating the need for intensive care, allowing them to contemplate their preferences regarding life-sustaining treatment. However, it is difficult for patients and their family members to openly discuss their thoughts on life-sustaining treatment, even if they are aware of the risk of a sudden crisis. Therefore, when patients and their families discuss ACP, the inclusion of healthcare coaching and counseling may be more effective. These measures of ACP support could add to increased family discussions, concordance, and shared decision-making with physicians.

5.
J Perioper Pract ; 33(10): 308-317, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-36113431

RESUMEN

Discussing advanced care planning tends to be complex and difficult for patients. Nonetheless, the subject should be briefed prior to high-risk surgery. Patient decision aids have the potential to facilitate the discussions of advanced care planning. This study aimed to develop and validate such patient decision aids in patients who are scheduled for high-risk surgery. Two patient decision aids were developed based on systematic processes and international standards. Their content quality was evaluated, both by health care providers and patients postoperatively admitted to the intensive care unit in Japan. Survey content included comprehensibility, length and suggested improvements to each patient decision aid, which were assessed via questionnaires, free descriptions and interviews. The patient decision aids considered were accepted by both patients and health care providers. However, there was concern among physicians regarding preoperative anxiety increases observed in patients who used them, suggesting that their clinical implementation may be challenging.


Asunto(s)
Planificación Anticipada de Atención , Humanos , Encuestas y Cuestionarios , Pacientes , Personal de Salud , Técnicas de Apoyo para la Decisión , Toma de Decisiones
6.
J Nurs Res ; 30(2): e202, 2022 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-35323135

RESUMEN

BACKGROUND: Interdisciplinary collaboration in the intensive care unit (ICU) is crucial for improving the quality of patient care. Furthermore, interdisciplinary team members need to establish team leadership to function effectively in solving problems. However, the influence of improving leadership ability in nurses on interdisciplinary collaboration efficacy is uncertain. PURPOSE: This study was designed to clarify the relationship between nursing leadership ability and interdisciplinary collaboration. METHODS: This cross-sectional study included 3,324 nurses with > 3 years of experience working in an ICU in Japan as participants. The investigation period was from April to September 2016. The developed questionnaire addressed leadership ability (Self-Assessment Inventory of Leadership role for staff nurses) and activities and perceptions related to multidisciplinary collaboration (Collaboration and Satisfaction About Care Decisions). The questionnaires were then collected and mailed. RESULTS: The 2,063 valid questionnaire responses gave a valid response rate of 61%. Nursing leadership ability was found to be significantly higher in advanced practice nurses (APNs; 78.8 ± 9.5, p < .001) and nurses in higher positions (74.9 ± 8.9, p < .001) than in non-APNs. However, no differences were found in terms of ICU management systems (p = .116). In addition, higher levels of nursing leadership were associated with greater team coordination (ß = .212), higher levels of interdisciplinary collaboration in the ICU (ß = .196), and the perception of many medical staff members, as well as patients and family members, to be team members (ß = .140) and APNs (ß = .128; p < .001). CONCLUSIONS/IMPLICATIONS FOR PRACTICE: Improving the leadership ability of critical care nurses may impact interdisciplinary collaboration positively. Leadership ability in nurses was shown to be related to a high level of cooperation among multiple healthcare providers. To enhance leadership ability in critical care nurses, nurses must increase their level of knowledge and ability. However, examining and implementing educational methods, including the improvement of coordination ability mainly by APNs, remain a challenge.


Asunto(s)
Unidades de Cuidados Intensivos , Liderazgo , Cuidados Críticos , Estudios Transversales , Humanos , Encuestas y Cuestionarios
7.
Nurs Open ; 8(2): 997-1001, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33570270

RESUMEN

AIM: This scoping review aims to elucidate the effectiveness of advance care planning interventions for patients entering the intensive care unit and their families. DESIGN: Scoping review of relevant literature from January 2000-March 2020. METHODS: This review includes studies undertaken in intensive care units that focus on patients older than 18 years or their families. The review will be conducted in accordance with the PRISMA-P guideline. The PubMed, EMBASE, CINAHL, BNI, PsycINFO and ICHUSHI databases and the Cochrane Library will be searched for both published and unpublished articles. Two independent reviewers will examine the list of remaining titles and summarize and identify articles that meet the inclusion criteria. RESULTS: It has long been taboo to consider end-of-life care when in intensive care unit. However, promoting advance care planning, even in patients who are in the intensive care unit, is important and it may help support the patient's need for autonomy.


Asunto(s)
Planificación Anticipada de Atención , Cuidado Terminal , Humanos , Unidades de Cuidados Intensivos , Literatura de Revisión como Asunto , Revisiones Sistemáticas como Asunto
8.
SAGE Open Nurs ; 7: 23779608211038845, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34632057

RESUMEN

INTRODUCTION: Patients in intensive care units (ICUs) may transition into an end-of-life phase during treatment. Advance care planning (ACP) for this population has not been studied comprehensively, and support for its implementation is insufficient. OBJECTIVE: This study aims to clarify the ACP support needs among critical perioperative patients. METHODS: In this qualitative descriptive study, semistructured interviews were conducted with patients previously admitted to the ICU. The survey was conducted from September to November 2019. Participants comprised 13 individuals, who were admitted to the ICU for a period of 3 months to 2 years after surgery. RESULTS: The average age of the participants was 63.8 years. The average mechanical ventilation duration following surgery was 24.5 h. The interviews focused on the ACP needs from the preoperative period to discharge. About 90% of the patients thought about the possibility of death before surgery and considered giving advance orders (e.g., "I don't want life-sustaining treatment"). The participants discussed inheritance, work-related matters, and household issues with their families but rarely spoke about treatment and care. Although they examined the content of the advance directives, the medical staff was not informed about them. Patients revealed that they wanted to understand the distinction between life-prolonging and life-saving treatments and discuss it with the medical staff, apart from being educated on ACP. Many patients previously admitted to the ICU are unclear about the difference between life-prolonging and life-saving treatments; this is also true for medical staff. CONCLUSION: Patients who had been admitted to the ICU after high-risk surgery thought they needed help with ACP before surgery. Therefore, patients have the right to know about treatment risks; however, medical staff believes that this is difficult to communicate. Thus, medical staff should consider ways to communicate clearly with patients, including discussing the risks associated with surgery.

9.
J Phys Chem B ; 122(29): 7233-7242, 2018 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-29956543

RESUMEN

We have evaluated the strength of intramolecular hydrogen bond in a protein based on molecular dynamics and quantum chemical calculation. To estimate the intramolecular hydrogen bond strength in okadaic acid (OA), we analyzed the influence of solvent and protonation states on the hydrogen bond and the entire structure. We performed molecular dynamics calculation and analyzed the strength of the hydrogen bond by measuring bond length and bond angle. The stable structure differs depending on the kind of solvent used and the protonation state of OA. Using the mean interaction energy from the quantum chemical calculation, hydrogen bond length and angle were investigated against bond energy. Although dielectric constant slightly depends on bond energy, the estimation of the intramolecular hydrogen bond strength in OA is possible even in a protein environment. The Coulomb interaction between OA and surrounding arginine produced a more negatively charged O1 in OA. The hydrogen bond energy in the deprotonated state is larger than that in the protonated state.


Asunto(s)
Simulación de Dinámica Molecular , Ácido Ocadaico/química , Teoría Cuántica , Enlace de Hidrógeno , Termodinámica , Agua/química
10.
World J Crit Care Med ; 7(1): 1-8, 2018 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-29430402

RESUMEN

AIM: To evaluate the effects of mineralocorticoid receptor (MR) antagonists on mortality and inflammatory responses after hemorrhagic shock (HS) in rats. METHODS: One hundred and two male Sprague-Dawley rats were randomly assigned to one of the following three groups: Control, spironolactone (SPL), and eplerenone (EP) groups. HS was induced by the removal of blood. One half of rats were evaluated to determine mortality, hemodynamics, plasma tumor necrosis factor-alpha (TNF-α) concentrations, and arterial blood gas at 8 h after HS recovery. In the remainder of rats, the expression levels of genes encoding cytokines were evaluated in liver tissue samples at 1 h after HS recovery. RESULTS: The survival rates 8 h after HS recovery were 71%, 94%, and 82% in the control, SPL, and EP groups, respectively. There were no significant differences in survival rates among the three groups (P = 0.219). Furthermore, there were no significant differences in gene expression levels in the liver or plasma TNF-α concentrations among the three groups (P = 0.888). CONCLUSION: Pretreatment with MR antagonists did not improve mortality or cytokine responses in the liver after HS recovery in rats.

11.
Biomed Res ; 27(2): 61-7, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16707844

RESUMEN

CD98 is a widely expressed cell surface heterodimeric protein of 125 kDa. Its expression is upregulated during lymphocyte activation induced by mitogen, superantigen, conventional antigen, and a combination of phorbol myristate acetate (PMA) and ionomycin. However, the role of CD98 in the immune system is not so well understood. The role of CD98 in murine T lymphocyte proliferation was investigated, especially in correlation with the interleukin 2 (IL-2)/interleukin 2 receptor (IL-2R) system. Monoclonal antibody (mAb) directed against murine CD98 heavy chain (mCD98HC) suppressed the proliferation of lymphocytes stimulated with concanavalin A (Con A). Anti-mCD98HC mAb did not suppress the expression of IL-2Ralpha. Anti-IL-2Ralpha mAb, which suppressed DNA synthesis, did not inhibit the expression of CD98HC. Murine IL-2 (recombinant), which induced considerable DNA synthesis by lymphocytes stimulated with a sub-optimal dose of Con A, did not induce CD98HC expression in lymphocytes. In addition, anti-mCD98HC mAb did not inhibit the production of IL-2 by lymphocyte stimulated with Con A. Taken together with these findings, it was speculated that the CD98 system is independent of the IL-2/IL-2R system in murine T lymphocyte activation.


Asunto(s)
Cadena Pesada de la Proteína-1 Reguladora de Fusión/inmunología , Interleucina-2/inmunología , Activación de Linfocitos , Receptores de Interleucina-2/inmunología , Linfocitos T/inmunología , Animales , Anticuerpos Monoclonales/metabolismo , Concanavalina A/farmacología , Masculino , Ratones , Ratones Endogámicos C57BL , Linfocitos T/efectos de los fármacos
12.
Biofactors ; 22(1-4): 255-8, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15630293

RESUMEN

A great deal of effort has been made on the effect of oxidative stress for smokers. What seems to be lacking, however, is its evidence. Analyzing 1076 participants (age 35.9 +/- 12.9, urinary8-OHdG Mean +/- S.D., 11.4 +/- 6.7, n = 1076), our study found the significant increase in a biomarker of DNA damage urinary 8-OHdG/creatinine among smokers (7.75 +/- 2.8 ng/ml x CRE (n = 154) and 7.36 +/- 2.5 ng/ml x CRE (n = 627) (p < 0.05), Relative Risk = 2.9 (1.4-6.2) sex and age +/- 2 matching 105 male smokers and non-smokers. There was no significance on the comparison between female smokers and non-smokers. Smokers have significantly decreased serum alpha-tocopherol (1012 +/- 455, 1152 +/- 857, p < 0.03). The amount of serum ascorbate did not change. Smokers lowered serum HDL-cholesterol compared to non-smokers (59.3 +/- 11.8, 63.9 +/- 13.3, p < 0.05). The result of oxidative stress profile (OSP) also indicated that the increase of oxidative stress to smokers (p < 0.05). The calculated value of oxygen radical absorbance capacity (ORAC) of the meal for subjects was 1600 ORAC units.


Asunto(s)
Biomarcadores/orina , Daño del ADN , Desoxiguanosina/análogos & derivados , Desoxiguanosina/orina , Estrés Oxidativo , Fumar/orina , 8-Hidroxi-2'-Desoxicoguanosina , Adulto , Humanos , Masculino , Valores de Referencia , Análisis de Regresión , Fumar/efectos adversos
13.
Hypertens Res ; 35(3): 287-94, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22113355

RESUMEN

Aldosterone is implicated in the pathogenesis of several cardiovascular diseases, including ischemia reperfusion (I/R) and myocardial infarction, and also causes oxidative stress and inflammation in cardiovascular systems. Benidipine, a long-acting T- and L-type calcium channel blocker, reduces infarct size following myocardial I/R in rabbits. Benidipine also inhibits the production of aldosterone in vitro. However, the precise mechanism of this phenomenon in vivo remains unknown. We therefore evaluated whether benedipine has a beneficial role through the regulation of oxidative stress in myocardial I/R. C57BL/6J mice were subjected to 30 min of left ascending coronary I/R. Benidipine was administered orally at 3 mg kg(-1) daily for 3 weeks without any changes in hemodynamic variables. Benidipine significantly reduced infarction size (13.4±2.5%) compared with controls (25.5±3.6%). Urinary 8-hydroxy-2' deoxyguanosine (8-OHdG), a marker of oxidative DNA damage, increased significantly after I/R. I/R induced increases in 8-OHdG were significantly lower with benidipine. Local myocardial 8-OHdG was also elevated in I/R, but this augmentation was significantly suppressed with benidipine. The plasma aldosterone concentration (PAC) significantly increased 2 days after I/R and remained elevated at least 7 days after I/R. Treatment with benidipine significantly decreased I/R-induced elevation of the PAC. I/R-induced markers of fibrosis in hearts also reduced in benidipine. These results suggest that the administration of benidipine reduces myocardial infarct size as well as systemic oxidative stress after I/R. These phenomena are partially linked to reduced plasma aldosterone levels.


Asunto(s)
Aldosterona/sangre , Dihidropiridinas/farmacología , Daño por Reperfusión Miocárdica/complicaciones , Daño por Reperfusión Miocárdica/fisiopatología , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/fisiología , Animales , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Bloqueadores de los Canales de Calcio/farmacología , Modelos Animales de Enfermedad , Regulación hacia Abajo/efectos de los fármacos , Hemodinámica/efectos de los fármacos , Hemodinámica/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Infarto del Miocardio/patología , Disfunción Ventricular Izquierda/fisiopatología
14.
Anim Sci J ; 83(5): 367-74, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22574788

RESUMEN

Genetic improvement of resistance to infectious diseases is a challenging goal in animal breeding. Infection resistance involves multiple immunological characteristics, including natural and acquired immunity. In the present study, we developed an experimental model based on genetic selection, to improve immunological phenotypes. We selectively established three mouse lines based on phagocytic activity, antibody production and the combination of these two phenotypes. We analyzed the immunological characteristics of these lines using a lipopolysaccharide (LPS), which is one of the main components of Gram-negative bacteria. An intense immunological reaction was induced in each of the three mouse lines. Severe loss of body weight and liver damage were observed, and a high level of cytokine messenger RNA was detected in the liver tissue. The mouse line established using a combination of the two selection standards showed unique characteristics relative to the mouse lines selected on the basis of a single phenotype. Our results indicate that genetic selection and breeding is effective, even for immunological phenotypes with a relatively low heritability. Thus, it may be possible to improve resistance to infectious diseases by means of genetic selection.


Asunto(s)
Inmunidad Adaptativa , Inmunidad Innata , Lipopolisacáridos/inmunología , Selección Genética , Animales , Formación de Anticuerpos/fisiología , Infecciones Bacterianas , Citocinas/análisis , Susceptibilidad a Enfermedades , Predisposición Genética a la Enfermedad/genética , Ratones , Fagocitosis , Fenotipo , Reacción en Cadena en Tiempo Real de la Polimerasa , Transaminasas/metabolismo
15.
Bioresour Technol ; 100(2): 791-7, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18657419

RESUMEN

An analytical scheme for the separation of humic substances (HSs) and non-humic substances (non-HSs) was established to estimate the humification index (HI), which was defined as the ratio of HS carbon content to non-HS carbon content. The alkaline compost-extract contained a mixture of HSs and non-HSs, while acidification of the compost-extract resulted in precipitation of humic acid (HA). The acidified supernatant contained fulvic acid (FA) and non-HSs. In the present study, DAX-8 resin was used to separate FA and non-HSs. HI values, which were estimated to evaluate the maturity of wood waste compost, increased with composting duration. To determine the effects of compost maturity on HA structural features, correlations between HI and indicators of the degree of HA humification (atomic ratios, acidic functional group contents, spectroscopic parameters and molecular weight) were investigated. HI values were significantly related to the indicators of the extent of HA humification during composting.


Asunto(s)
Sustancias Húmicas , Residuos Industriales/análisis , Modelos Químicos , Suelo/análisis , Madera/química , Simulación por Computador , Ensayo de Materiales , Factores de Tiempo
16.
Biosci Biotechnol Biochem ; 66(12): 2573-7, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12596850

RESUMEN

Synthesized PCs containing docosahexaenoic acid (DHA), arachidonic acid (AA), linoleic acid (LA), and palmitic acid (PA) at known positions in the glycerol moiety were oxidized in liposomes, bulk, and organic solvent. In bulk and organic solvent, the oxidative stability of PC decreased with increasing degrees of unsaturation. However, the degree of unsaturation had little effect on the stability of PC in liposomes. The oxidative stability of PC in liposomes would be affected by the chemical reactivity based on the degree of unsaturation and by the conformation of fatty acyl component in PC bilayers. When the oxidative stability of 1-PA-2-LA-PC or 1-PA-2-AA-PC was compared with that of a 1:1 (mol ratio) mixture of 1,2-diPA-PC + 1,2-diLA-PC, or 1,2-diPA-PC + 1,2-diAA-PC, respectively, the former PC was more oxidatively stable than that of the latter PC mixture in all oxidation systems, although the degree of unsaturation of 1-PA-2-PUFA-PC was the same as that of the corresponding mixture of diPA-PC + diPUFA-PC. The higher oxidative stability of 1-PA-2-PUFA-PC than that of a corresponding mixture of diPA-PC + diPUFA-PC in liposomes was suggested to be due to the different conformation of PC bilayers and the different rate of hydrogen abstraction by free radicals from intermolecular and intramolecular acyl groups.


Asunto(s)
Ácidos Grasos Insaturados/química , Liposomas/química , Fosfatidilcolinas/química , Ácido Araquidónico/química , Ácidos Docosahexaenoicos/química , Oxidación-Reducción , Ácido alfa-Linolénico/química
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