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1.
BMC Musculoskelet Disord ; 25(1): 42, 2024 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-38195509

RESUMEN

BACKGROUND: Mutations of the COL2A1 gene have been identified in patients with Perthes' disease. Several studies have hypothesised a connection between Perthes' disease and collagen synthesis disorders, especially COL2A1-related disorders, but no large studies on the subject have been made. The aim of this study was thus to discover if there is a connection between patients presenting with Perthes' disease, and collagen synthesis disorders. A secondary aim was to see if the children with both disorders had less optimal birth characteristics than the rest. METHODS: Swedish national registers were used to collect data on children diagnosed with Perthes' disease or a collagen synthesis disorder. These registers include all births in Sweden, and data from both outpatient and in-hospital visits. A wide range of data is included besides diagnoses. All children with follow-up data to the age of 15 years were included. Pearson's chi-square was used for analysis. Statistical significance was further analysed with Fisher's Exact Test. RESULTS: In total, 3488 children with either diagnosis were included. 1620 children had only Perthes disease, while 1808 children had only a collagen synthesis disorder. Five children were found to have both the diagnosis Perthes' disease and a collagen synthesis disorder. One child was large for their gestational age and none of the children had a low birthweight. Two of the children were moderately preterm. CONCLUSIONS: The distinct lack of overlap in such a large body of material raises doubt about a connection between the presentation of Perthes' disease and collagen synthesis disorders, either COL2A1-related or not. We could not find an overrepresentation of less optimal birth characteristics either.


Asunto(s)
Enfermedad de Legg-Calve-Perthes , Niño , Recién Nacido , Humanos , Adolescente , Enfermedad de Legg-Calve-Perthes/epidemiología , Enfermedad de Legg-Calve-Perthes/genética , Suecia/epidemiología , Emociones , Edad Gestacional , Colágeno
2.
Phys Rev Lett ; 121(5): 052001, 2018 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-30118290

RESUMEN

Exclusive measurements of the quasifree pp→ppπ^{+}π^{-} reaction have been carried out at WASA@COSY by means of pd collisions at T_{p}=1.2 GeV. Total and differential cross sections have been extracted covering the energy region T_{p}=1.08-1.36 GeV, which is the region of N^{*}(1440) and Δ(1232)Δ(1232) resonance excitations. Calculations describing these excitations by t-channel meson exchange are at variance with the measured differential cross sections and underpredict substantially the experimental total cross section. An isotensor ΔN dibaryon resonance with I(J^{P})=2(1^{+}) produced associatedly with a pion is able to overcome these deficiencies.

3.
Phys Rev Lett ; 120(2): 022002, 2018 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-29376676

RESUMEN

Taking advantage of the high acceptance and axial symmetry of the WASA-at-COSY detector, and the high polarization degree of the proton beam of COSY, the reaction p[over →]p→ppη has been measured close to threshold to explore the analyzing power A_{y}. The angular distribution of A_{y} is determined with the precision improved by more than 1 order of magnitude with respect to previous results, allowing a first accurate comparison with theoretical predictions. The determined analyzing power is consistent with zero for an excess energy of Q=15 MeV, signaling s-wave production with no evidence for higher partial waves. At Q=72 MeV the data reveal strong interference of Ps and Pp partial waves and cancellation of (Pp)^{2} and Ss^{*}Sd contributions. These results rule out the presently available theoretical predictions for the production mechanism of the η meson.

4.
Mycorrhiza ; 27(4): 383-396, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28066872

RESUMEN

Hydrophobins are small secreted proteins that are present as several gene copies in most fungal genomes. Their properties are now well understood: they are amphiphilic and assemble at hydrophilic/hydrophobic interfaces. However, their physiological functions remain largely unexplored, especially within mycorrhizal fungi. In this study, we identified hydrophobin genes and analysed their distribution in eight mycorrhizal genomes. We then measured their expression levels in three different biological conditions (mycorrhizal tissue vs. free-living mycelium, organic vs. mineral growth medium and aerial vs. submerged growth). Results confirmed that the size of the hydrophobin repertoire increased in the terminal orders of the fungal evolutionary tree. Reconciliation analysis predicted that in 41% of the cases, hydrophobins evolved from duplication events. Whatever the treatment and the fungal species, the pattern of expression of hydrophobins followed a reciprocal function, with one gene much more expressed than others from the same repertoire. These most-expressed hydrophobin genes were also among the most expressed of the whole genome, which suggests that they play a role as structural proteins. The fine-tuning of the expression of hydrophobin genes in each condition appeared complex because it differed considerably between species, in a way that could not be explained by simple ecological traits. Hydrophobin gene regulation in mycorrhizal tissue as compared with free-living mycelium, however, was significantly associated with a calculated high exposure of hydrophilic residues.


Asunto(s)
Proteínas Fúngicas/genética , Duplicación de Gen , Genoma Fúngico , Micorrizas/genética , Genómica , Micelio
5.
Epidemiol Infect ; 142(11): 2261-9, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24476659

RESUMEN

In 2010, a marked increase in listeriosis incidence was observed in Finland. Listeria monocytogenes PFGE profile 96 was responsible for one-fifth of the reported cases and a cluster of PFGE profile 62 was also detected. Investigations revealed two fishery production plants with persistent Listeria contamination. It appears likely that the plants were at least partly responsible for the increase of listeriosis. Epidemiological investigation revealed that 57% (31/54) of cases with underlying immunosuppressive condition or medication reported eating gravad or cold-smoked fish. Two public notices were issued by THL and Evira informing which groups were most at risk from the effects of listeriosis and should therefore be cautious in consuming certain products. Systematic sampling of foods and adequate epidemiological investigation methods are required to identify the sources of Listeria infections. Continuous control measures at fishery production plants producing risk products are essential.


Asunto(s)
Explotaciones Pesqueras , Contaminación de Alimentos/estadística & datos numéricos , Listeria/clasificación , Listeriosis/epidemiología , Animales , Brotes de Enfermedades , Femenino , Finlandia/epidemiología , Contaminación de Alimentos/prevención & control , Microbiología de Alimentos , Industria de Procesamiento de Alimentos , Humanos , Incidencia , Listeria/patogenicidad , Listeriosis/diagnóstico , Masculino , Sistema de Registros , Medición de Riesgo
6.
Phys Chem Chem Phys ; 16(27): 13718-25, 2014 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-24728264

RESUMEN

We have prepared an yttrium modified Pt(111) single crystal under ultra-high vacuum conditions, simulating a bulk alloy. A Pt overlayer is formed upon annealing the crystal above 800 K. The annealed structure binds CO weaker than Pt(111), with a pronounced peak at 295 K in the temperature programmed desorption of CO. When depositing a large amount of yttrium at 1173 K, a (1.88 × 1.88)R30° structure relative to Pt(111) was observed by low energy electron diffraction. Such an electron diffraction pattern could correspond to a (2 × 2)R30° structure under 6% compressive strain. This structure is in agreement with the structure of the vacancies in a Pt Kagomé layer in Pt5Y rotated 30° with respect to the bulk of the Pt(111). The Pt overlayer is relatively stable in air; however, after performing oxygen reduction activity measurements in an electrochemical cell, a thick Pt overlayer was measured by the angle resolved X-ray photoelectron spectroscopy depth profile. The activity of the annealed Y/Pt(111) for the oxygen reduction reaction was similar to that of polycrystalline Pt3Y.

7.
Int J Dent Hyg ; 12(1): 48-54, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23730835

RESUMEN

The immune response is influenced by genetic and epigenetic factors, as well as disease and environmental factors. The term 'epigenetics' describes changes in the genome that influence the gene expression without altering the DNA sequence. In contrast to genetic changes in the DNA, epigenetic changes are reversible and are influenced by environmental factors. The aim of this study is to review the literature on epigenetic modifications with respect to oral health and inflammatory conditions in the oral cavity and to discuss the potential use of this new research field for the dental hygienists' and/or dentists' clinical work. Relevant publications were identified using the PubMed database without limits. The searches were conducted during January to March 2012 and resulted in articles published between 1912 and 2012. Key factors such as environment, diet, smoking, bacteria and inflammation were identified to be relevant to oral health. The result of this review article shows that there is a void in the research on epigenetics in relation to oral health. Identification of epigenetic modifications correlating with oral health may not only present a link between the influence of genetics and that of the environment on oral diseases but also provide new treatment models and tools for the dental professionals.


Asunto(s)
Epigénesis Genética/genética , Interacción Gen-Ambiente , Enfermedades de la Boca/genética , Salud Bucal , Fenómenos Fisiológicos Bacterianos , Dieta , Ambiente , Epigenómica , Gingivitis/etiología , Gingivitis/genética , Humanos , Enfermedades de la Boca/etiología , Periodontitis/etiología , Periodontitis/genética , Fumar
8.
Epidemiol Infect ; 141(8): 1640-6, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23068603

RESUMEN

In 2010, 7/44 (16%) reported foodborne outbreaks in Finland were linked with raw beetroot consumption. We reviewed data from the national outbreak registry in order to hypothesize the aetiology of illness and to prevent further outbreaks. In the seven outbreaks, 124 cases among 623 respondents were identified. Consumption of raw beetroot was strongly associated with gastrointestinal illness (relative risk 8∙99, 95% confidence interval 6∙06-13∙35). The illness was characterized by sudden onset of gastrointestinal symptoms; the median incubation time was 40 min and duration of illness 5 h. No common foodborne pathogens or toxins were found in either clinical or beetroot samples, but all tested beetroot samples were of poor quality according to total bacterial counts. Beta-haemolytic Pseudomonas fluorescens was detected in several beetroot samples but its effect on human health is unknown. No outbreaks were reported after the Finnish Food Safety Authority Evira advised against serving raw beetroot in institutional canteens.


Asunto(s)
Beta vulgaris/envenenamiento , Brotes de Enfermedades , Microbiología de Alimentos , Enfermedades Transmitidas por los Alimentos/epidemiología , Gastroenteritis/epidemiología , Adolescente , Adulto , Anciano , Beta vulgaris/microbiología , Estudios de Cohortes , Femenino , Finlandia/epidemiología , Enfermedades Transmitidas por los Alimentos/microbiología , Gastroenteritis/microbiología , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Estaciones del Año , Adulto Joven
9.
Br J Anaesth ; 110(6): 926-39, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23578861

RESUMEN

Elective surgery is usually preceded by preoperative diagnostics to minimize risk. The results are assumed to elicit preventive measures or even cancellation of surgery. Moreover, physicians perform preoperative tests as a baseline to detect subsequent changes. This systematic review aims to explore whether preoperative testing leads to changes in management or reduces perioperative mortality or morbidity in unselected patients undergoing elective, non-cardiac surgery. We systematically searched all relevant databases from January 2001 to February 2011 for studies investigating the relationship between preoperative diagnostics and perioperative outcome. Our methodology was based on the manual of the Ludwig Boltzmann Institute for Health Technology Assessment, the Scottish Intercollegiate Guidelines Network (SIGN) handbook, and the PRISMA statement for reporting systematic reviews. One hundred and one of the 25 281 publications retrieved met our inclusion criteria. Three test grid studies used a randomized controlled design and 98 studies used an observational design. The test grid studies show that in cataract surgery and ambulatory surgery, there are no significant differences between patients with indicated preoperative testing and no testing regarding perioperative outcome. The observational studies do not provide valid evidence that preoperative testing is beneficial in healthy adults undergoing non-cardiac surgery. There is no evidence derived from high-quality studies that supports routine preoperative testing in healthy adults undergoing non-cardiac surgery. Testing according to pathological findings in a patient's medical history or physical examination seems justified, although the evidence is scarce. High-quality studies, especially large randomized controlled trials, are needed to explore the effectiveness of indicated preoperative testing.


Asunto(s)
Procedimientos Quirúrgicos Electivos , Cuidados Preoperatorios , Proteína C-Reactiva/análisis , Hematócrito , Hemoglobinas/análisis , Humanos , Pruebas de Función Renal , Recuento de Leucocitos , Pruebas de Función Hepática , Ensayos Clínicos Controlados Aleatorios como Asunto
10.
Epidemiol Psychiatr Sci ; 32: e39, 2023 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-37303201

RESUMEN

AIM: Research on the effect of oral contraceptive (OC) use on the risk of depression shows inconsistent findings, especially in adult OC users. One possible reason for this inconsistency is the omission of women who discontinue OCs due to adverse mood effects, leading to healthy user bias. To address this issue, we aim to estimate the risk of depression that is associated with the initiation of OCs as well as the effect of OC use on lifetime risk of depression. METHODS: This is a population-based cohort study based on data from 264,557 women from the UK Biobank. Incidence of depression was addressed via interviews, inpatient hospital or primary care data. The hazard ratio (HR) between OC use and incident depression was estimated by multivariable Cox regression with OC use as a time-varying exposure. To validate causality, we examined familial confounding in 7,354 sibling pairs. RESULTS: We observed that the first 2 years of OC use were associated with a higher rate of depression compared to never users (HR = 1.71, 95% confidence interval [CI]: 1.55-1.88). Although the risk was not as pronounced beyond the first 2 years, ever OC use was still associated with an increased lifetime risk of depression (HR = 1.05, 95% CI: 1.01-1.09). Previous OC use were associated with a higher rate of depression compared to never users, with adolescent OC users driving the increased hazard (HR = 1.18, 95% CI: 1.12-1.25). No significant association were observed among adult OC users who had previously used OCs (HR = 1.00, 95% CI: 0.95-1.04). Notably, the sibling analysis provided further evidence for a causal effect of OC use on the risk of depression. CONCLUSIONS: Our findings suggest that the use of OCs, particularly during the first 2 years, increases the risk of depression. Additionally, OC use during adolescence might increase the risk of depression later in life. Our results are consistent with a causal relationship between OC use and depression, as supported by the sibling analysis. This study highlights the importance of considering the healthy user bias as well as family-level confounding in studies of OC use and mental health outcomes. Physicians and patients should be aware of this potential risk when considering OCs, and individualized risk-benefit assessments should be conducted.


Asunto(s)
Depresión , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Adolescente , Adulto , Humanos , Femenino , Estudios de Cohortes , Depresión/epidemiología , Cognición , Anticonceptivos Orales/efectos adversos
11.
Phys Rev Lett ; 106(24): 242302, 2011 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-21770567

RESUMEN

We report on an exclusive and kinematically complete high-statistics measurement of the basic double-pionic fusion reaction pn→dπ(0)π(0) over the full energy region of the ABC effect, a pronounced low-mass enhancement in the ππ-invariant mass spectrum. The measurements, which cover also the transition region to the conventional t-channel ΔΔ process, were performed with the upgraded WASA detector setup at COSY. The data reveal the Abashian-Booth-Crowe effect to be uniquely correlated with a Lorentzian energy dependence in the integral cross section. The observables are consistent with a narrow resonance with m=2.37 GeV, Γ≈70 MeV and I(J(P))=0(3(+)) in both pn and ΔΔ systems. Necessary further tests of the resonance interpretation are discussed.

12.
J Appl Microbiol ; 108(3): 956-964, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19735331

RESUMEN

AIMS: The aim of this study was to evaluate the efficiency of four isolation methods for the detection of pathogenic Yersinia enterocolitica from pig intestinal content. METHODS AND RESULTS: The four methods comprised of 15 isolation steps using selective enrichments (irgasan-ticarcillin-potassium chlorate and modified Rappaport broth) and mildly selective enrichments at 4 or 25 degrees C. Salmonella-Shigella-desoxycholate-calcium chloride agar, cefsulodin-irgasan-novobiocin agar were used as plating media. The most sensitive method detected 78% (53/68) of the positive samples. Individual isolation steps using cold enrichment as the only enrichment or as a pre-enrichment step with further selective enrichment showed the highest sensitivities (55-66%). All isolation methods resulted in high numbers of suspected colonies not confirmed as pathogenic Y. enterocolitica. CONCLUSIONS: Cold enrichment should be used in the detection of pathogenic Y. enterocolitica from pig intestinal contents. In addition, more than one parallel isolation step is needed. SIGNIFICANCE AND IMPACT OF THE STUDY: The study shows that depending on the isolation method used for Y. enterocolitica, the detected prevalence of Y. enterocolitica in pig intestinal contents varies greatly. More selective and sensitive isolation methods need to be developed for pathogenic Y. enterocolitica.


Asunto(s)
Recuento de Colonia Microbiana/métodos , Intestinos/microbiología , Porcinos/microbiología , Yersinia enterocolitica/aislamiento & purificación , Animales , Medios de Cultivo , Datos de Secuencia Molecular , Valor Predictivo de las Pruebas , Sensibilidad y Especificidad , Serotipificación , Enfermedades de los Porcinos/microbiología , Yersinia enterocolitica/clasificación
13.
Science ; 208(4444): 557-63, 1980 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-17732829

RESUMEN

The project "Energy and Society," sponsored by the Swedish Secretariat for Futures Studies, has studied different indigenous energy sources as alternatives to imported oil in Sweden. One alternative is nuclear energy, antoer is renewable energy. Large uncertainties are associated with both alternatives today. The main characteristics of an energy policy for the rest of the century that does not foreclose either of these options have been identified. Such a policy will have to be based on an understanding of similarities and differences between the alternatives. A nuclear and a solar energy system have been outlined as a basis for an analysis of technical, economic, and institutional issues.

14.
Science ; 219(4583): 355-61, 1983 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-17815302

RESUMEN

Technology now being introduced in industry, buildings, and transportation is much more energy-efficient than today's average technology. Changes in production and consumption are tending to decrease the intensity of energy use. By applying available economic technology, it may be possible to reduce energy use in Sweden from the present 1400 petajoules per year to about 900 petajoules per year soon after the turn of the century, even with a 50 percent increase in the consumption of goods and services. Technology now being developed could reduce energy demand even further.

15.
J Appl Microbiol ; 106(6): 1976-85, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19228254

RESUMEN

AIM: To screen and characterize toxic, heat-stable substances produced by food borne strains from Bacillus subtilis group. METHODS AND RESULTS: Using the boar sperm motility inhibition assay, six isolates from two outbreaks, out of the 94 isolates from 26 foods, were found to produce ethanol-soluble heat-stable substances that were toxic to sperm cells by depleting the mitochondrial membrane potentials. The toxic isolates were identified as Bacillus subtilis and B mojavensis. Colon carcinoma cells (Caco-2) were used to model the contact with the human digestive tract. The extract of B. subtilis F 2564/96 depolarized the mitochondria in intact Caco-2 cells similarly as in sperm cells. The substance responsible for these effects was purified using HPLC and identified by electron spray ionization ion trap mass spectrometry analysis as amylosin. The temperature requirement for amylosin production was 21-37 degrees C for B. subtilis and 11-21 degrees C for B. mojavensis. Both species produced amylosin in air as well as in 7-8% CO(2) with 8-9% O(2). CONCLUSIONS: Food borne illness related strains of B. subtilis and B. mojavensis, produced the heat-stable toxin amylosin. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report that suggests a role for the heat-stable, ion-channel forming toxin amylosin, as a virulence factor in food borne Bacillus.


Asunto(s)
Bacillus/metabolismo , Toxinas Bacterianas/metabolismo , Enterotoxinas/genética , Leche/microbiología , Microbiología del Suelo , Animales , Bacillus/genética , Bacillus/aislamiento & purificación , Bacillus subtilis/genética , Bacillus subtilis/aislamiento & purificación , Bacillus subtilis/metabolismo , Proteínas Bacterianas/genética , Toxinas Bacterianas/toxicidad , Células CACO-2/efectos de los fármacos , Cromatografía Líquida de Alta Presión , ADN Bacteriano/análisis , ADN Bacteriano/genética , Electroforesis en Gel de Campo Pulsado , Enterotoxinas/aislamiento & purificación , Enterotoxinas/toxicidad , Enfermedades Transmitidas por los Alimentos/microbiología , Proteínas de Choque Térmico/genética , Humanos , Masculino , ARN Ribosómico 16S/genética , Proteínas de Unión al ARN/genética , Espermatozoides/efectos de los fármacos , Porcinos , Temperatura
16.
Insect Mol Biol ; 17(1): 73-85, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18237286

RESUMEN

Moths generally rely on pheromone communication for mate finding. The pheromone components of most moths are produced by a common pathway of fatty-acid biosynthesis coupled with species-specific modifications of the final products. Some genes involved in moth pheromone production have previously been described, whereas others remain to be characterized and thus the molecular mechanisms accounting for the production of species-specific blends are far from understood. The turnip moth, Agrotis segetum, has a multicomponent pheromone, consisting of at least four components derived from palmitic and stearic acid. Different populations produce and respond to different pheromone blends, which makes this species an excellent model for research on genes and molecular mechanisms involved in moth pheromone production. For this purpose, we performed an expressed sequence tag (EST) analysis of two cDNA libraries, one representing the female pheromone gland and the other representing the remainder of the insect body. Among 2285 ESTs analysed altogether, we identified a unigene set of 707 putative gene representatives. The comparative distribution of those in the two libraries showed the transcriptomes of the tissues to be clearly different. One third of the gene representatives were exclusively found in the pheromone gland. From sequence homology to public database information we assigned putative functional roles for a majority of the unigenes and then compared functional profiles of the two tissues. In the set of ESTs more abundant in the pheromone gland library, we found homologues of an acyl-CoA Delta11-desaturase, a G-protein subunit, a chemosensory protein as well as a juvenile hormone binding protein.


Asunto(s)
Etiquetas de Secuencia Expresada , Mariposas Nocturnas/metabolismo , Atractivos Sexuales/biosíntesis , Animales , Femenino , Biblioteca de Genes , Mariposas Nocturnas/genética , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Atractivos Sexuales/genética , Transcripción Genética
17.
Int J Food Microbiol ; 124(2): 154-63, 2008 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-18472176

RESUMEN

A collaborative study was organised to define the performance characteristics of the revised NMKL Method No.136 "Listeria monocytogenes. Detection and enumeration in foods". Chromogenic L. monocytogenes specific plating medium, Agar Listeria according to Ottaviani and Agosti (ALOA) was introduced in the revised method in order to improve the sensitivity and specificity of the method, and to shorten the analysis time. Efficacy of ALOA One Day from AES (ready-to-use agar in bottles), Listeria Chromogenic Agar (Agosti and Ottaviani Listeria agar) from Lab M (LCA) (dehydrated powder), Chromogenic Listeria Agar Plates from Oxoid (OCLA) (ready-to-use plates) and L. monocytogenes blood agar medium LMBA from Lab M (dehydrated powder) were tested. Three types of food matrices (vacuum-packed hot-smoked salmon, soft cheese and cooked ham) and one feed matrix (wheat grain) inoculated with two levels of L. monocytogenes with or without L. innocua were used in the study. A total of 24 samples were analysed both in the detection and enumeration part of the study by 18 and 17 Nordic laboratories, respectively. The sensitivities of ALOA, LCA, OCLA and LMBA in the detection of L. monocytogenes in food samples after one-step enrichment (Half-Fraser) were 94.4-96.4% and after two-step enrichment (Half-Fraser followed by Fraser) 97.7-100%. For wheat grain the respective figures were 84.7-88.9% and 90.3-93.1%, respectively. The precision characteristics were generally good for the enumeration of L. monocytogenes in the food samples with high levels of inoculation. Several poor values obtained from the food samples with low levels of inoculation probably reflect high uncertainty of measurement when less than 10 cfu/g was counted. Poor values obtained from the wheat grain samples by any of the media evaluated were due to poor precision for feed samples. According to the study, the revised NMKL Method No.136, 4th ed. showed excellent results in the detection and satisfactory results in the enumeration of L. monocytogenes in foods. The results for the detection of L.monocytogenes in wheat grain were good, but the method cannot be recommended for the enumeration of L. monocytogenes in feed-stuffs. Any one of the media evaluated can interchangeably be used as an obligatory isolation medium for the detection and enumeration of L. monocytogenes in foods, and for the detection in feed-stuffs. The L. monocytogenes specific plating media that were evaluated shorten the time of analysis and significantly reduce the work load. The detection of positive samples mostly after Half-Fraser enrichment, reduces the analysis time further, and makes it possible to skip the secondary enrichment. However, secondary enrichment cannot be totally left out, because samples with low levels of L. monocytogenes, with high levels of competing flora, and with injured L. monocytogenes, do need secondary enrichment.


Asunto(s)
Técnicas de Laboratorio Clínico/normas , Recuento de Colonia Microbiana/normas , Contaminación de Alimentos/análisis , Microbiología de Alimentos , Listeria monocytogenes/aislamiento & purificación , Agar , Alimentación Animal/análisis , Alimentación Animal/microbiología , Compuestos Cromogénicos , Recuento de Colonia Microbiana/métodos , Seguridad de Productos para el Consumidor , Reacciones Falso Negativas , Reacciones Falso Positivas , Humanos , Sensibilidad y Especificidad , Factores de Tiempo
18.
Spectrochim Acta A Mol Biomol Spectrosc ; 69(5): 1294-300, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18006375

RESUMEN

Two types of automatic fitting procedures for EPR spectra of disordered systems have been developed, one based on matrix diagonalization of a general spin Hamiltonian, the other on 2nd order perturbation theory. The first program is based on a previous Fortran code complemented with a newly written interface in Java to provide user-friendly in and output. The second is intended for the special case of free radicals with several relatively weakly interacting nuclei, in which case the general method becomes slow. A least squares' fitting procedure utilizing analytical or numerical derivatives of the theoretically calculated spectrum with respect to the g- and hyperfine structure (hfs) tensors was used to refine those parameters in both cases. 'Rigid limit' ESR spectra from radicals in organic matrices and in polymers, previously studied experimentally at low temperature, were analyzed by both methods. Fluorocarbon anion radicals could be simulated, quite accurately with the exact method, whereas automatic fitting on, e.g. the c-C(4)F(8)(-) anion radical is only feasible with the 2nd order approximative treatment. Initial values for the (19)F hfs tensors estimated by DFT calculations were quite close to the final. For neutral radicals of the type XCF(2)CF(2)* the refinement of the hfs tensors by the exact method worked better than the approximate. The reasons are discussed. The ability of the fitting procedures to recover the correct magnetic parameters of disordered systems was investigated by fittings to synthetic spectra with known hfs tensors. The exact and the approximate methods are concluded to be complementary, one being general, but limited to relatively small systems, the other being a special treatment, suited for S=1/2 systems with several moderately large hfs.


Asunto(s)
Espectroscopía de Resonancia por Spin del Electrón/métodos , Fluorocarburos/química , Compuestos Inorgánicos/química , Simulación por Computador
19.
Handb Exp Pharmacol ; (178): 315-45, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17203661

RESUMEN

In the postgenomic era, a primary focus of mouse genetics is to elucidate the role of individual genes in vivo. However, in the nervous system, studying the contribution of specific genes to brain functions is difficult because the brain is a highly complex organ with multiple neuroanatomical structures, orchestrating virtually every function in the body. Further, higher-order brain functions such as learning and memory simultaneously recruit several signaling cascades in different subcellular compartments and have highly fine-tuned spatial and temporal components. Conditional transgenic and gene targeting methodologies, however, now offer valuable tools with improved spatial and temporal resolution for appropriate studies of these functions. This chapter provides an overview of these tools and describes how they have helped gain better understanding of the role of candidate genes such as the NMDA receptor, the protein kinase CaMKIIIalpha, the protein phosphatases calcineurin and PP1, or the transcription factor CREB, in the processes of learning and memory. This review illustrates the broad and innovative applicability of these methodologies to the study of brain plasticity and cognitive functions.


Asunto(s)
Encéfalo/metabolismo , Técnicas de Transferencia de Gen , Memoria , Plasticidad Neuronal/genética , Recombinación Genética/genética , Animales , Receptores de N-Metil-D-Aspartato/metabolismo
20.
J Phys Chem B ; 110(33): 16567-74, 2006 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-16913791

RESUMEN

We present sum frequency generation vibrational spectroscopy data on monolayer films of pure stearonitrile and mixed films of stearonitrile and ferric stearate deposited by the Langmuir Blodgett technique. Films ranging in composition from pure stearonitrile to 65% stearonitrile/35% ferric stearate deposit in a head-to-tail, Z-type architecture while films of composition <65% stearonitrile deposit in a head-to-head, tail-to-tail, Y-type structure. The vibrational spectra of the monolayer films corresponding to these two different architectures show distinct and characteristic features in their CH stretching regions. Spectral analysis indicates little difference in the modes associated with the terminal methyl groups but large differences in the methylene CH(2) vibrational modes. These spectral differences are consistent with alkyl chains that possess uncompensated methylene oscillator strength arising from portions of the chain that are bent. This behavior is consistent with the energetics expected from a close-packed monolayer of stearonitrile molecules whose CN headgroups possess sizable dipole moments and are expected to adopt a large center-to-center angle to minimize electrostatic, dipole-dipole repulsive interactions.

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