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1.
Sci Rep ; 14(1): 4062, 2024 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-38374163

RESUMEN

The negative effect of caponization on the structural, geometric and mechanical parameters of femur and tibia has been shown in a few studies. Nevertheless, its influence on tibia bone microarchitecture is still largely unknown. Therefore, this study aimed to assess the effect of castration on the microstructural parameters of the trabecular and compact bone of tibia bone in crossbred chickens. The experiment involved 96 roosters derived from crossing Yellowleg Partridge hens ([Formula: see text]-33) and Rhode Island Red cockerels (R-11) fattened until the 16th, 20th and 24th week of life. Animals were randomly divided into 2 groups of 48 each. Group I (control) consisted of intact roosters and group II (experimental) consisted of birds subjected to caponization at the 8th week of age. The castration surgery had no influence on some properties within compact bone such as osteon diameter On.Dm, osteon perimeter On.Pm, osteon area On.Ar, osteocyte lacunar number Ot.Lc.N, osteon bone area On.B.Ar, osteon wall thickness On.W.Th as well as thick-mature collagen content in all analyzed age groups of animals. Nevertheless, our results demonstrate that castration caused a decrease of Haversian canal area Hc.Ar, osteocyte lacunar area Ot.Lc.Ar and osteocyte lacunar porosity Ot.Lc.Po among the 16-week-old birds, decrease of Haversian canal perimeter Hc.Pm and increase of fraction of bone area On.B.Ar/On.Ar among 16- and 24-week-old individuals and also an increase of osteocyte lacunar density Ot.Lc.Dn in the osteons of the oldest roosters. Additionally, some microstructural parameters of trabecular bone show the negative effect of caponization. The youngest 16-week-old capons were characterized by thinnin the trabecular in the epiphysis part of tibia. Moreover, in the case of 24-week-old, there is an increase in the trabecular separation Tb.Sp with simultaneous decrease of trabecular number Tb.N compared to roosters, which may suggest the increase of the bone resorption among the oldest individuals. The increased bone turnover in the epiphysis part of the tibia bone also indicates changes in the collagen fibers distribution, where among 20-week-old animals there is a decrease in the content of immature thin collagen fibers with simultaneous increase in the content of mature thick collagen fibers. Furthermore, among the oldest 24-week-old individuals we can observe the increased thick-to-thin collagen ratio, which may be a sign of slowing down in bone formation.


Asunto(s)
Pollos , Tibia , Humanos , Masculino , Animales , Femenino , Fémur , Epífisis , Colágeno
2.
Sci Rep ; 13(1): 14512, 2023 09 04.
Artículo en Inglés | MEDLINE | ID: mdl-37667027

RESUMEN

The presented study focuses on assessing the effect of caponization on the densitometric, osteometric, geometric and biomechanical parameters of tibial bones in crossbred chickens. The study was carried out on 96 hybrids between Yellowleg Partridge hens (Z-33) and Rhode Island Red cockerels (R-11) aged 16 weeks, 20 weeks and 24 weeks. Birds were randomly assigned to 2 groups-the control group (n = 48; which consisted of intact roosters) and the experimental group (n = 48, which consisted of individuals subjected to caponization at the age of 8 weeks). The caponization had no effect on the densitometric, osteometric and geometric parameters (except the horizontal internal diameter of 16-week-old individuals) of tibia bone, as well as the content of calcium (Ca), phosphorus (P) and the Ca/P ratio in the bone mineral fraction in all analyzed age groups of animals. However, it contributes to a lower percentage of ash in the bones of capons at 20 and 24 weeks of age compared to cockerels. On the contrary, some mechanical and material parameters show the negative effect of caponization. Ultimate load and bending moment decreased in capons in all of the analyzed age groups of animals and yield load, stiffness and ultimate stress also decreased but only in the group of 20-week-old and 24-week-old individuals. This can contribute to the weakening of the capon bones, and in the perspective of prolonged maintenance to their deformation and even fracture.


Asunto(s)
Calcificación Fisiológica , Calcinosis , Animales , Femenino , Masculino , Calcio de la Dieta , Pollos , Homeostasis , Tibia
3.
Clin Lymphoma Myeloma Leuk ; 22(11): 847-852, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35985959

RESUMEN

The phase 1b 16-BCNI-001/CTRIAL-IE 16-02 CyBorD-DARA trial investigated the combination of Daratumumab with cyclophosphamide, bortezomib and dexamethasone in patients with newly diagnosed multiple myeloma (NDMM), followed by autologous stem cell transplantation and Daratumumab maintenance. CR/sCR rates were 50% after transplant and 62.5% at end of treatment. The overall percentage of patients achieving complete response or better was 77.8%. Progression-free survival rate at end of maintenance was 81.3% and estimated 2-year overall survival was 88.9%. 37.5% of patients demonstrated sustained MRD negativity to a level of 10-5 from transplant to analysis at EOT. In this phase 1b study, we have shown CyBorD-DARA to be an effective and well-tolerated immunomodulatory agent-free regiment in transplant-eligible NDMM.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica , Mieloma Múltiple , Humanos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Bortezomib/uso terapéutico , Ciclofosfamida/uso terapéutico , Dexametasona/uso terapéutico , Trasplante de Células Madre Hematopoyéticas/métodos , Mieloma Múltiple/tratamiento farmacológico , Trasplante Autólogo , Resultado del Tratamiento
4.
Poult Sci ; 100(3): 100863, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33516470

RESUMEN

The aim of the study was to determine shell quality of eggs laid by some strains of native breed hens of different ages, with special consideration of their effect on lysozyme concentration and enzymatic activity. Evaluation was made of the eggshells from 6 breeds/strains of laying hens covered by the gene pool protection program in Poland: Greenleg Partridge (Z-11), Yellowleg Partridge (Z-33), Rhode Island Red (R-11), Rhode Island White (A-33), Sussex (S-66), and Leghorn (H-22). Significant (P ≤ 0.01) differences were established for all the shell quality characteristics between hen strains. As the birds aged, shell weight and porosity increased, and shell compression strength decreased in all the experimental groups. Lysozyme content was lowest in white-shelled eggs (H-22) and highest in cream-colored and light brown eggs (Z-11, Z-33, and R-11). Furthermore, age of hens had a greater effect on lysozyme concentration and activity in the eggs than on shell quality traits. Regardless of the layer genotype, eggs from older hens showed higher lysozyme concentration and enzymatic activity.


Asunto(s)
Albúminas , Pollos , Cáscara de Huevo , Muramidasa , Óvulo , Albúminas/genética , Albúminas/metabolismo , Animales , Biodiversidad , Pollos/clasificación , Pollos/genética , Cáscara de Huevo/fisiología , Femenino , Genotipo , Muramidasa/genética , Muramidasa/metabolismo , Óvulo/química , Óvulo/enzimología , Polonia
5.
Blood Adv ; 3(12): 1815-1825, 2019 06 25.
Artículo en Inglés | MEDLINE | ID: mdl-31201169

RESUMEN

Daratumumab (DARA) has shown impressive activity in combination with other agents for the treatment of multiple myeloma (MM). We conducted a phase 1b study to assess the safety and preliminary efficacy, as well as potential mechanisms of action, of DARA (16 mg/kg) in combination with a weekly schedule of subcutaneous bortezomib (1.3-1.5 mg/m2), cyclophosphamide (150-300 mg/m2), and dexamethasone (40 mg) (CyBorD DARA) as initial induction before autologous stem cell transplantation (ASCT). Eligible patients were ≤70 years of age with untreated MM requiring treatment and who lacked significant comorbidities. A total of 18 patients were enrolled. Their median age was 56 years (range, 32-66 years), and all patients had Eastern Cooperative Oncology Group performance status ≤1. The International Staging System stages were I, II, and III in 78%, 17%, and 6% of patients, respectively; 28% of patients had high-risk genetic features. There was no dose-limiting toxicity, and the incidence of grade 3 or 4 infection or neutropenia was <10%. On an intention-to-treat basis, 94% achieved ≥very good partial response with ≥complete response in 44% of patients. Among 14 of 15 patients who underwent ASCT and were evaluable for response, all 14 achieved at least very good partial response, with 8 (57%) of 14 achieving complete response. After ASCT, 10 (83%) of 12 patients in whom minimal residual disease analysis was possible were negative at a sensitivity of 10-5 (56% on intention-to-treat/whole study population) according to next-generation sequencing. Flow cytometry analysis of patient samples indicated CyBorD DARA induced activation of macrophage-mediated antibody-dependent cellular phagocytosis. This trial was registered at www.clinicaltrials.gov as #NCT02955810.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Mieloma Múltiple/tratamiento farmacológico , Adulto , Anciano , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales/farmacología , Antineoplásicos Alquilantes/administración & dosificación , Antineoplásicos Alquilantes/uso terapéutico , Antineoplásicos Hormonales/administración & dosificación , Antineoplásicos Hormonales/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica , Bortezomib/administración & dosificación , Bortezomib/uso terapéutico , Ciclofosfamida/administración & dosificación , Ciclofosfamida/uso terapéutico , Dexametasona/administración & dosificación , Dexametasona/uso terapéutico , Femenino , Trasplante de Células Madre Hematopoyéticas , Humanos , Incidencia , Infecciones/inducido químicamente , Infecciones/epidemiología , Inyecciones Subcutáneas , Irlanda/epidemiología , Masculino , Persona de Mediana Edad , Neutropenia/inducido químicamente , Neutropenia/epidemiología , Inhibidores de Proteasoma/administración & dosificación , Inhibidores de Proteasoma/uso terapéutico , Trasplante Autólogo , Resultado del Tratamiento
6.
Br Poult Sci ; 60(4): 423-430, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30958027

RESUMEN

1. In this study, 240 ISA Brown hens were fed diets containing different levels of hybrid rye, and the influence of xylanase addition on laying performance and egg quality was evaluated. 2. Birds were allocated to 10 treatment groups with 12 replicates (cages) of two hens and were fed, from week 26 to 50, isocaloric and isonitrogenous experimental diets. A 5 × 2 experimental arrangement was applied, using diets with increasing level of rye (0%, 10%, 15%, 20% or 25%) with or without xylanase supplementation (200 mg/kg of feed; Ronozyme WX (CT) with minimum xylanase activity of 1,000 FXU/g). 3. Increasing dietary level of rye did not affect daily mass of eggs, mean egg weight or feed conversion ratio (P > 0.05). Laying rate decreased in all groups fed with rye. Egg and eggshell quality indices were unaffected by dietary rye grain (P > 0.05); however, rye inclusion significantly decreased yolk colour on the DSM scale (P < 0.05). In comparison with the control group, high dietary levels of rye (25%) significantly increased viscosity of small intestine content (P < 0.05). Diet supplementation with xylanase had no significant effect on egg production indices and egg quality (except for yolk colour) but decreased the viscosity of intestinal content in laying hens fed high levels of rye (P < 0.05). 4. The results of this experiment suggest that rye may be incorporated to a level of 25% in the diet of laying hens without any strong negative effect on egg performance, while xylanase added to high-rye grain reduced the viscosity of intestinal content; however, it did not positively affect the laying performance or egg quality.


Asunto(s)
Pollos/fisiología , Óvulo/efectos de los fármacos , Reproducción/efectos de los fármacos , Secale/química , Xilano Endo-1,3-beta-Xilosidasa/metabolismo , Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales/efectos de los fármacos , Animales , Dieta/veterinaria , Suplementos Dietéticos/análisis , Cáscara de Huevo/efectos de los fármacos , Cáscara de Huevo/fisiología , Femenino , Óvulo/fisiología , Reproducción/fisiología , Xilano Endo-1,3-beta-Xilosidasa/administración & dosificación
7.
Br Poult Sci ; 59(2): 245-249, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29235892

RESUMEN

1. The effects of changes in technical efficiency on the increase of broiler production are presented for the period 1994-2013 based on the panel data from seven farms located in southern and central Poland. A total of 766 cycles were analysed. 2. The Cobb-Douglas production function was used to assess the changes of output elasticities as well as technical changes in broiler production, for 5-year sub-periods separately. 3. Technical indices of broiler production significantly improved between years 1994-2013: feed conversion ratio decreased from 2.50 kg/kg to 1.78 kg/kg, mortality rate from 8.8% to 4.0% and daily weight gain increased from 37.1 g/d to 58.7 g/d, respectively. 4. Before accession to the EU, there was a substantial increase of fixed capital connected with modernisation of buildings and equipment. In the period 1994-2013, inputs of fixed capital per kilogram of livestock increased by 72% and at the same time the input of labour decreased by 56%. 5. Technical changes in years 1994-1998 contributed to a rapid production increase at a rate of 4.6% annually and only by up to 0.7% annually during 2009-2013. The slowdown of production rate increase after 2009 was partially caused by decreasing the stocking density.


Asunto(s)
Crianza de Animales Domésticos/métodos , Pollos , Crianza de Animales Domésticos/tendencias , Animales , Polonia , Aumento de Peso
8.
Ir J Med Sci ; 186(2): 345-347, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-27170271

RESUMEN

INTRODUCTION: Hairy cell leukemia (HCL) is an uncommon B cell lymphoproliferative disorder. The object of the present audit was to assess whether the investigation and management of HCL in University College Hospital Galway (UCHG) complies with the British Committee for Standards in Haematology (BCSH) guidelines. METHODS: Following a review of the records in our Haematology Department, 18 cases of HCL were identified between January 2006 and October 2014. RESULTS: Blood film examination had been performed in all cases. Flow cytometry of liquid material had been undertaken in 89 % (n = 16) of cases, of which only 31 % (n = 5) included all four hairy cell panel markers (CD11c, CD25, CD103, CD123). Although all initial trephine biopsies included CD20, none analyzed DBA44. Only 65 % (n = 11) of treated patients had a post-treatment bone marrow biopsy preformed. CONCLUSION: This audit highlights areas of improvement in the diagnosis and management of HCL in UCHG, which do not currently adhere to the BCSH recommendations.


Asunto(s)
Adhesión a Directriz , Leucemia de Células Pilosas/terapia , Guías de Práctica Clínica como Asunto , Adulto , Anciano , Linfocitos B , Femenino , Citometría de Flujo , Hematología , Hospitales Universitarios , Humanos , Masculino , Persona de Mediana Edad
9.
Skin Res Technol ; 21(2): 214-23, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25123912

RESUMEN

BACKGROUND/PURPOSE: The purpose of these studies was to determine the surface free energy of the human skin and its critical surface tension of wetting in the skin--surfactant aqueous solution--air system in relation to different types of surfactants. METHODS: The surface free energy of the skin and its components was calculated using the equilibrium advancing contact angle values of water, formamide, and diiodomethane on the forearm skin surface. Next, taking into account the measured values of the contact angle of aqueous solutions of SDDS, CTAB, TX-100 and TX-114 on the skin surface and data of their surface tension, the critical surface tension of the skin wetting was determined. RESULTS: We can classify the skin surface as low-energetic one. The critical surface tension of the skin wetting depends on the type of surfactant. CONCLUSION: It is possible to determine the critical surface tension of the human skin wetting on the basis of the values of the contact angle of aqueous solutions of surfactants and their surface tension. In this respect, nonionic surfactants seem to be the most appropriate.


Asunto(s)
Aire , Modelos Biológicos , Modelos Químicos , Piel/química , Tensoactivos/química , Agua/química , Adulto , Simulación por Computador , Femenino , Humanos , Masculino , Tensión Superficial , Humectabilidad
10.
Br Poult Sci ; 54(4): 478-85, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23826901

RESUMEN

1. A total of 192 ISA Brown hens were given diets containing a high concentration of maize dried distiller's grains with solubles (DDGS) and the effect of selected feed additives on laying performance and egg quality was determined. 2. Birds were allocated to 8 treatment groups with 12 replicates (cages) of two hens and were given, from week 26 to 55, iso-caloric and iso-nitrogenous experimental diets with or without a high concentration of DDGS (200 g/kg). The diet containing DDGS was not supplemented or supplemented with enzymes (xylanase and phytase), sodium butyrate, probiotic bacteria (Lactobacillus salivarius) and a mixture of herbal extracts (Taraxaci siccum, Urticae siccum and Salviae siccum), inulin or chitosan. 3. The inclusion of DDGS in the diet had no effect on number of eggs produced, total egg mass, mean egg weight, feed intake or feed conversion ratio. Egg and eggshell quality parameters were also unaffected by dietary DDGS. The yolk colour score (points in Roche scale) was significantly increased by DDGS inclusion. DDGS in the diet caused some changes in the yolk lipid profile that were rather unfavourable from a dietary perspective (an increase of cholesterol content, and PUFA n-6/PUFA n-3 ratio). 4. During the experimental period (26-55 weeks of age) supplementation of the diet containing a high concentration of DDGS with enzymes, inulin as well as chitosan, increased number of eggs produced and daily egg mass. In older hens (50 weeks of age) inulin positively affected eggshell quality parameters, i.e. shell percentage, thickness and density. Diet supplementation with herb extracts, inulin or chitosan, decreased the content of cholesterol in yolks. 5. The results of this study suggest that DDGS may be incorporated up to a concentration of 200 g/kg in the diet of laying hens without any negative effects on egg performance. Moreover, supplementation of xylanase and phytase, as well as inulin and chitosan, can positively affect the performance of layers given diets with a high concentration of DDGS.


Asunto(s)
Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Pollos/fisiología , Cáscara de Huevo/efectos de los fármacos , Reproducción/efectos de los fármacos , Animales , Pollos/microbiología , Dieta/veterinaria , Suplementos Dietéticos/análisis , Cáscara de Huevo/fisiología , Femenino , Zea mays/química
11.
Ir J Med Sci ; 182(3): 377-82, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23242576

RESUMEN

BACKGROUND: Acute lymphoblastic leukaemia (ALL), the commonest childhood malignancy has seen remarkable progress since the 1960s with cure rates now approaching 85%. To achieve this patients undergo intensive treatment that usually takes 2.5-3.5 years involving on average 15 different chemotherapeutic drugs. In 1971, Donald Pinkel reported Total Therapy-Protocol V that used 5 drugs and cranial radiation therapy over a similar time period. Today, one half of these patients (Pinkel's children) remain alive and free of leukaemia. AIM: The aim of this study was to evaluate the impact post-induction minimal residual disease (MRD) levels had on survival and its relationship with the more established clinical and biological prognostic predictors of outcome in the hope of identifying a subgroup of patients that are at very low risk of failure. METHODS: A retrospective review of 250 Irish children with ALL was carried out. MRD status after 28 days of induction chemotherapy and other known predictors of outcome were correlated with 5 year event-free survival (EFS). RESULTS: MRD status was the strongest predictor of outcome with 5 year EFS rates greater that 90% seen in those patients with low-risk MRD and this was associated with TEL/AML1 rearrangement, high hyperdiploidy (HH) karyotype and female gender. CONCLUSION: Both MRD and karyotype are powerful determinants of outcome in childhood ALL. Therefore, it is reasonable to conclude that the majority of children cured by Pinkel et al. in the late 1960s were most likely composed of low-risk MRD, TEL/AML1 and HH patients.


Asunto(s)
Neoplasia Residual/epidemiología , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiología , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Niño , Preescolar , Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Supervivencia sin Enfermedad , Femenino , Genotipo , Historia del Siglo XX , Humanos , Lactante , Estimación de Kaplan-Meier , Cariotipo , Masculino , Proteínas de Fusión Oncogénica/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/historia , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia
12.
Transplant Proc ; 43(8): 2954-6, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21996199

RESUMEN

INTRODUCTION: Maintenance of the target blood levels of immunosuppressive drugs is one of the main factors determining transplant function. The aim of this study was to assess the effect of the conversion of tacrolimus from twice daily (Tc) to the prolonged release form administered once daily (Tc-pr) including the variability of blood concentrations and glomerular filtration rates in kidney transplantation patients. MATERIALS AND METHODS: This retrospective analysis evaluated 52 patients including 23 females, and 29 males with established grafts who underwent a scheduled change of treatment from Tc to Tc-pr. We examined data from six consecutive visits before and six visits after conversion. RESULTS: The average daily dose of Tc was 3.8±2.6 mg/24 h, whereas mean coefficient of variation (CoV) calculated from the visits before conversion was 68%. After the conversion, the mean total daily dose of Tc-pr was not significantly lower (3.2±1.8 mg), as was the mean CoV at six subsequent visits 57% (P=ns). Blood concentrations in both analyzed periods remained in the target range (Tc-pr 6.7±2.9 ng/mL versus Tc-pr 5.0±1.11) with a lower CoV in the case of Tc-pr compared to Tc (22% versus 44%; P<.001). There was no difference in graft function in the analyzed periods. After conversion, lower blood glucose levels were observed: 103.4±28.3 mg/dL versus 95±25.9 mg/dL (P<.03). CONCLUSIONS: The slow-release form of tacrolimus provided greater stability of drug blood concentrations compared with the standard form administered twice daily. The change of the tacrolimus treatment from Tc to Tc-pr dosing did not effect organ function but seemed to improve glycemic control.


Asunto(s)
Inmunosupresores/administración & dosificación , Inmunosupresores/sangre , Trasplante de Riñón , Tacrolimus/administración & dosificación , Tacrolimus/sangre , Adulto , Glucemia/metabolismo , Creatinina/sangre , Preparaciones de Acción Retardada , Esquema de Medicación , Femenino , Tasa de Filtración Glomerular , Humanos , Trasplante de Riñón/fisiología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Tiempo
13.
Phys Chem Chem Phys ; 13(19): 8908-14, 2011 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-21678581

RESUMEN

The out-of-plane motion of the pyridinium cation in the bis-thiourea pyridinium chloride inclusion compound has been studied in a wide temperature range using (1)H NMR, dielectric spectroscopy and quasielastic neutron scattering. The geometry of this motion is obtained from the Q-dependence of the elastic incoherent structure factor determined from the quasielastic neutron scattering measurements. We find that the pyridinium cation performs out-of-plane reorientations around the axis passing through two opposite atoms of the ring. The correlation times as a function of temperature were measured in the three known crystallographic phases, finding a good agreement between the three techniques employed. The activation energy for this motion changes from 5 ± 1 kJ mol(-1) in the low-temperature phase to 1.2 ± 0.2 kJ mol(-1) in the intermediate and high-temperature phases.


Asunto(s)
Compuestos de Piridinio/química , Termodinámica , Cationes/química , Modelos Moleculares
14.
J Microsc ; 237(3): 411-5, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20500408

RESUMEN

Nickel is known to increase the resistance to cleavage fracture of iron and decrease a ductile-to-brittle transition temperature. The medium-carbon, low-alloy martensitic steels attain the best combination of properties in low-tempered condition, with tempered martensite, retained austenite and transition carbides in the microstructure. This paper is focused on the influence of Ni addition (from 0.35 to 4.00%) on the microstructure and fracture toughness of structural steels after tempering. In this research, four model alloys of different concentration of Ni and constant concentration of carbon and other elements were used. All samples were in as-quenched and tempered conditions. Quenching was performed in oil at room temperature. After quenching, samples were tempered at 200 degrees C for 2 h. The microstructure of the investigated steels was analyzed using JEM200CX transmission electron microscope. An increase of nickel content in the investigated structural steels causes a decrease of epsilon carbide concentration in their microstructure after tempering. In these steels, cementite precipitates independently in the boundaries of martensite needles and in the twin boundaries in the areas where the Fe(2.4)C carbide has been dissolved. These results will be used to design new technologies of tempering of structural steels with nickel addition.

15.
Phys Rev E Stat Nonlin Soft Matter Phys ; 79(3 Pt 1): 031912, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19391976

RESUMEN

We investigate a two-dimensional problem of an isolated self-interacting end-grafted polymer, pulled by one end. In the thermodynamic limit, we find that the model has only two different phases, namely a collapsed phase and a stretched phase. We show that the phase diagram obtained by Kumar [Phys. Rev. Lett. 98, 128101 (2007)] for small systems, where differences between various statistical ensembles play an important role, differs from the phase diagram obtained here in the thermodynamic limit.


Asunto(s)
Polímeros/química , Modelos Químicos , Método de Montecarlo , Transición de Fase , Temperatura , Termodinámica
16.
Phys Rev E Stat Nonlin Soft Matter Phys ; 76(5 Pt 1): 051904, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18233684

RESUMEN

We present results for a lattice model of polymers where the type of beta sheet formation can be controlled by different types of hydrogen bonds depending on the relative orientation of close segments of the polymer. Tuning these different interaction strengths leads to low-temperature structures with different types of orientational order. We perform simulations of this model and so present the phase diagram, ascertaining the nature of the phases and the order of the transitions between these phases.


Asunto(s)
Hidrógeno/química , Modelos Químicos , Modelos Moleculares , Proteínas/química , Proteínas/ultraestructura , Simulación por Computador , Enlace de Hidrógeno , Transición de Fase , Conformación Proteica
17.
Phys Rev Lett ; 96(24): 240603, 2006 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-16907227

RESUMEN

We introduce a new class of models for polymer collapse, given by random walks on regular lattices which are weighted according to multiple site visits. A Boltzmann weight omegal is assigned to each (l+1)-fold visited lattice site, and self-avoidance is incorporated by restricting to a maximal number K of visits to any site via setting omegal=0 for l>or=K. In this Letter we study this model on the square and simple cubic lattices for the case K=3. Moreover, we consider a variant of this model, in which we forbid immediate self-reversal of the random walk. We perform simulations for random walks up to n=1024 steps using FlatPERM, a flat histogram stochastic growth algorithm. We find evidence that the existence of a collapse transition depends sensitively on the details of the model and has an unexpected dependence on dimension.

18.
Peptides ; 26(5): 837-43, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15808914

RESUMEN

15 nM/kg b.m. of neurotensin (NT) caused a significant inhibition of LMA within 30 min of administration and this effect persisted up for to the 240 th minute of the experiment. A 15 nM/kgb.m. dose also caused a reduction in SLA which persisted up to the 120 th minute. Sixty minutes after an intraperitoneal administration of NT a decrease in the cholesterol and NEFA levels and an increase in the TG and glycerol levels were observed. These effects were inhibited by the NTR2-blocker (levocabastine) and were not subject to change after an in vivo application of SR 48692.


Asunto(s)
Metabolismo de los Lípidos , Movilización Lipídica/efectos de los fármacos , Neurotensina/farmacología , Animales , Lípidos/sangre , Masculino , Neurotensina/administración & dosificación , Ratas , Ratas Wistar
19.
Lett Appl Microbiol ; 40(4): 255-9, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15752214

RESUMEN

AIMS: Volatile compounds present in strawberries infected with Phytophthora cactorum, especially those responsible for the characteristic off-odour of such fruits were the subject of this study. METHODS AND RESULTS: Six strawberry varieties (Redgauntlet, Selva, Korona, Tenira, Real, Pegasus) inoculated with P. cactorum strain (PC-5), isolated from naturally infected fruit and one variety inoculated with 15 strains of P. cactorum in the laboratory were analysed. All the samples had a distinct, to a various degree, off-odour reminiscent of watercolour paint with phenolic notes. Volatile compounds were isolated by solid phase microextraction and simultaneous distillation extraction methods. To detect compounds responsible for the characteristic off-odour, gas chromatography-olfactometry was used. Two compounds were found to be responsible for the characteristic off-odour of strawberries infected by P. cactorum: 4-ethyl phenol and 4-ethyl-2-metoxy phenol (4-ethyl guaiacol). The content of these compounds in infected varieties ranged from 1.12 to 22.56 mg kg(-1) and 0.14-1.05 mg kg(-1) respectively. Other volatile compounds, not detected in noninoculated sound strawberries, were also identified: camphene, 1-octene-3-ol, 3-octanone, o-cymene, phenyl methanol, cis-linaloloxide, nonanal, phenyl ethyl alcohol, 2-undecanone and alpha-muurolene. SIGNIFICANCE AND IMPACT OF THE STUDY: Volatile compounds responsible for the characteristic off-odour of strawberries infected with P. cactorum were identified. Also compounds produced as a result of P. cactorum growth on strawberry fruit were characterized.


Asunto(s)
Fragaria/microbiología , Guayacol/análogos & derivados , Guayacol/aislamiento & purificación , Odorantes , Fenoles/aislamiento & purificación , Phytophthora/crecimiento & desarrollo , Phytophthora/metabolismo , Aldehídos/aislamiento & purificación , Alcoholes Bencílicos/aislamiento & purificación , Monoterpenos Bicíclicos , Cromatografía de Gases , Fragaria/química , Guayacol/análisis , Cetonas/aislamiento & purificación , Octanoles/aislamiento & purificación , Fenoles/análisis , Alcohol Feniletílico/aislamiento & purificación , Terpenos/aislamiento & purificación
20.
Acta Crystallogr B ; 59(Pt 3): 384-92, 2003 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12761408

RESUMEN

Crystals of uranium iodine phthalocyanine present an example of a disordered commensurate modulated structure of the intergrowth type. The short-range order of both uranium ions and iodine chains [I(3)(-)](n) has been analysed by Reverse Monte Carlo (RMC) simulation of X-ray diffuse scattering. The diffraction pattern of uranium iodine phthalocyanine contains diffuse superstructure reflections. In the routine crystal structure analysis diffuse superstructure reflections may be either omitted or measured and classified along with other Bragg reflections. The crystal structure of uranium iodine phthalocyanine is an example of such ambiguity. The crystal structures of two specimens of [U(1-x)Pc(2)]I(2-y) with slightly different composition have been published in the literature with different space groups and unit cells. We have shown that the structure of both specimens differs only in the degree of short-range order and is isostructural with [YbPc(2)]I(2). We have also shown that while the omission of diffuse reflections results in the average crystal structure, the treatment of these reflections as normal Bragg reflections is incorrect and produces the structure averaged over a limited small range.

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