PubMed Health⌕ Search

Biomedical subjects

B Rubio

Publications and source records attributed to B Rubio.

At least 19 recordsLinked to original sources
PubMed2026

Sympatric European white oaks species display contrasting epigenetic response to soil water availability.

In the context of climate change plants have to cope with adverse conditions, among which water scarcity is a major threat for their survival. They have developed diverse regulatory processes to face drought that may differ depending on their ecological niche. The two sympatric oaks species (Quercus robur L. and Quercus petraea (Matt.). Liebl) have different levels of drought tolerance. We have investigated their strategies to face drought stress by analysing the transcriptome, small RNAome and methylome dynamics of young plants grown under control and drought stress conditions. Data indicate that cell wall remodeling is most likely involved in the better tolerance Q. petraea than of Q. robur. Furthermore, major methylation differences were identified between both oak species that were in part associated to their difference in drought stress responses. Integration of the three datasets revealed genomic co-locations of potential importance for forest tree adaptation to drought stress. Our data are consistent with species-specific molecular responses of oak to drought stress related to their ecological niches.

Forest trees- Omics- ecological niche↗
PubMed2006

Observation of 54Ni: cross-conjugate symmetry in f7/2 mirror energy differences.

Gamma decays from excited states up to Jpi=6+ in the N=Z-2 nucleus 54Ni have been identified for the first time. Level energies are compared with those of the isobars 54Co and 54Fe and of the cross-conjugate nuclei of mass A=42. The good but puzzling f7/ cross-conjugate symmetry in mirror and triplet energy differences is analyzed. Shell model calculations reproduce the new data but the necessary nuclear charge-dependent phenomenology is not fully explained by modern nucleon-nucleon potentials.

Journal Article↗
PubMed2006

Beach morphodynamics forcements in oiled shorelines: Coupled physical and chemical processes during and after fuel burial.

In November 2002, the sinking of the Prestige oil tanker off the Galician coast (N.W. Spain) caused the largest ecological catastrophe in the history of Spain, affecting the coast called the 'Costa da Morte' (Galicia, N.W. Spain). This work is focused on the study of the oil contamination of the intertidal area of two beaches located on this stretch of coast. The study of twenty cores extracted from both beaches has identified fuel embedded in the sedimentary column up to a depth of 2.38 m (this being the maximum depth of extraction). This, along with the presence of oil below the groundwater indicates the existence of a new factor which determines the burial of oil: the morphodynamic behaviour of the beach. Furthermore, this morphodynamic variation conditions the physical appearance of the buried oil. Four different types have been identified: tar-balls (cm), particles (mm), oil coatings on sediment grains and on emulsion, with distribution patterns conditioned by the degree of wave exposure. The analysis of the information obtained have permitted the development of a conceptual model of the burial and oil evolution in the sedimentary column in relation to wave exposure, and thus to the morphodynamic variability of the beach.

Accidents, Occupational↗
PubMed2005

Gamow-teller strengths in proton-rich exotic nuclei deduced in the combined analysis of mirror transitions.

Isospin symmetry is expected for the T(z)=+/-1-->0 isobaric analogous transitions in isobars with mass number A, where T(z) is the z component of isospin T. Assuming this symmetry, strengths of analogous Gamow-Teller (GT) transitions within A = 50 isobars were determined from a high energy-resolution study at 0 degrees in combination with the decay Q value and lifetime from the beta decay. This method can be applied to other pf-shell nuclei and can be used to study GT strengths of astrophysical interest.

Journal Article↗
PubMed2004

Deformation of the N=Z nucleus 76Sr using beta-decay studies.

A novel method of deducing the deformation of the N=Z nucleus 76Sr is presented. It is based on the comparison of the experimental Gamow-Teller strength distribution B(GT) from its beta decay with the results of quasi-random-phase approximation calculations. This method confirms previous indications of the strong prolate deformation of this nucleus in a totally independent way. The measurement has been carried out with a large total absorption gamma spectrometer, "Lucrecia," newly installed at CERN-ISOLDE.

Journal Article↗
PubMed2001

Coulomb energy differences in t = 1 mirror rotational bands in (50)Fe and (50)Cr.

Gamma rays from the N = Z-2 nucleus (50)Fe have been observed, establishing the rotational ground state band up to the state J(pi) = 11+ at 6.994 MeV excitation energy. The experimental Coulomb energy differences, obtained by comparison with the isobaric analog states in its mirror (50)Cr, confirm the qualitative interpretation of the backbending patterns in terms of successive alignments of proton and neutron pairs. A quantitative agreement with experiment has been achieved by exact shell model calculations, incorporating the differences in radii along the yrast bands, and properly renormalizing the Coulomb matrix elements in the pf model space.

Journal Article↗
PubMed2001

A phase II study of gemcitabine in gallbladder carcinoma.

BACKGROUND: Due to the high mortality rates from gallbladder carcinoma in Chile, we conducted a phase II trial to test the efficacy and safety of gemcitabine in patients with locally advanced or metastatic gallbladder carcinoma. PATIENTS AND METHODS: From January 1998 to February 2000, 26 patients with metastatic or unresectable gallbladder carcinoma and no prior chemotherapy received gemcitabine 1,000 mg/m2 over 30 minutes weekly for three weeks followed by a week of rest. RESULTS: Patients received a median of 4.2 cycles (range 1-10). Out of the 25 patients whose response could be evaluated, 9 went into partial remission, an overall response rate of 36% (95% confidence interval (95% CI): 17.1% to 57.9%). In six (25.0%) patients, the cancer remained stable, and in 10 (40%) it progressed. Median survival time was 30 weeks (range 7-80+. Hematological toxicities were mild, with no cases of febrile neutropenia or hemorrhage. However, four and one patient(s) had grades 1-2 and 3-4 neutropenia, respectively, and two patients had grade 2 thrombocytopenia. Nine patients experienced grade 1-2 nausea/vomiting, but were able to continue treatment. There were no toxic deaths. CONCLUSIONS: In this phase II trial, gemcitabine is an active chemotherapy in metastatic or inoperable gallbladder carcinoma, with a manageable toxicity profile.

Adult↗
PubMed2001

Influence of the activation temperature on the SO2 removal capacity and mechanical performance of pelletized activated chars.

The influence of steam activation temperature on the SO2 removal capability of subbituminous coal char pellets (SCCP) as well as the changes in their mechanical properties, were studied. The SCCP were prepared by pressing at 125 MPa a blend of a char, obtained by carbonization at 850 degrees C, and a commercial coal tar pitch. After a curing stage in air at 200 degrees C and a heat treatment at 900 degrees C in nitrogen, the SCCP were activated with steam (10g H2O min(-1)) for two hours at several temperatures: 600, 700, 750 and 800 degrees C. The SO2 adsorption capacity tests carried out at simulated flue gas conditions (100 degrees C, 10% H2O, 6% O2, 1s space velocity) show an important increase in the amount of adsorbed SO2 of the activated SCCP with respect to parent ones, whereas their mechanical performance decreases in the same proportion, mainly in the interval 700-750 degrees C. Increasing the temperature of activation, the SCCP undergo significant changes in textural features (total surface area measured in N2 and CO2, pore volume) as well as in surface oxygenated groups, as shown by TPD experiments. There is an optimum ratio between both parameters (around 8 micromol g(-1)) for the SO2 conversion at the studied conditions.

Adsorption↗
PubMed2001

[Gemcitabine in the treatment of 4 patients with cholangiocarcinoma].

Cholangiocarcinoma is a biliary tree cancer of unknown etiology, whose symptoms are unspecific and is usually detected in advanced stages. Surgery continues to be the only curative therapy. Median survival in patients with inoperable tumors ranges between 5 and 8 months. There are few studies on the effects of chemotherapy, with a very small response. We report four patients with advanced cholangiocarcinoma, treated with gemcitabine 1000 mg/m2, weekly for 3 weeks every 28 days. There was a stabilization of tumor size and symptoms were alleviated. Toxicity was low and there was a probable prolongation of survival.

Aged↗
PubMed2001

[MALT lymphoma of the bladder. Report of a case].

OBJECTIVE: To describe and discuss primary malignant lymphoreticular proliferative tumors of the bladder. METHODS: A case of a 70-year-old woman with hematuria, dysuria, malaise and 5-kg weight loss is presented. RESULTS: Pelvic ultrasound examination showed an 8 x 7 x 8 cm solid and cystic mass adjacent to the bladder and uterus. Cystoscopic biopsy disclosed a low grade B cell non-Hodgkin lymphoma. Disappearance of the mass was achieved with 6 cycles of chemotherapy and radiotherapy. Four years thereafter the patient remains free of disease. CONCLUSIONS: Primary malignant lymphoma of the bladder is uncommon. The anatomopathological study is essential to differential diagnosis from other diseases. The response to chemotherapy and radiotherapy are excellent and permits bladder preservation.

Aged↗
PubMed2000

[Efficacy of gemcitabine in the gallbladder cancer. Initial experience in 4 cases].

Surgery continues to be the only curative therapy for gallbladder cancer, but useful in very few patients. Mean survival of patients with gallbladder cancer, that are out of the reach of surgery, is 3 months. The few clinical trials of chemotherapy for this disease, report very low success rates. We report four patients with advanced gallbladder cancer, treated with gemcitabine in an intravenous dose of 1000 mg/m2, given in 30 min, once a week during three consecutive weeks, every 28 days. There was a partial response that lasted 40.3 23.2 weeks with a mean survival of 59.75 17 weeks. One patient survives without evidences of disease after 17 months of the diagnosis of an advanced cancer. In all patients, symptoms were alleviated, functional status and quality of life improved. Toxicity was mild and did not require reduction in doses or delay in therapy. Therefore, this medication deserves further investigation for the treatment of gallbladder cancer.

Adenocarcinoma↗
PubMed1998

Effect of focal cerebellar lesions on procedural learning in the serial reaction time task.

Prior studies have shown that procedural learning is severely impaired in patients with diffuse cerebellar damage (cortical degeneration) as measured by the serial reaction time task (SRTT). We hypothesize that focal cerebellar lesions can also have lateralized effects on procedural learning. Our objective was to assess the effects of focal cerebellar lesions in procedural learning as measured by the SRTT. We studied 14 patients with single, unilateral vascular lesions in the territory of the posterior-inferior or superior cerebellar artery, who were compared with ten age- and sex-matched controls in a one-handed version of the SRTT. Patients with lesions at any other level of the brain or posterior fossa were excluded by cranial magnetic resonance imaging. Our results show that patients do not acquire procedural knowledge when performing the task with the hand ipsilateral to the lesion, but show normal learning with the contralateral hand. No correlation was found with the side, size, or vascular territory of the lesion. We conclude that procedural learning is impaired in hemispheric cerebellar lesions and involves only the hand ipsilateral to the lesion, which suggests a critical role for the cerebellum and/or crossed cerebellar-prefrontal connections in this type of learning.

Adult↗
PubMed1996

Rapid-rate transcranial magnetic stimulation of left dorsolateral prefrontal cortex in drug-resistant depression.

BACKGROUND: Lesion and neuroimaging studies suggest that left prefrontal lobe dysfunction is pathophysiologically linked to depression. Rapid-rate transcranial magnetic stimulation (rTMS) to prefrontal structures has a lateralised effect on mood in normal volunteers, and several preliminary studies suggest a beneficial effect of rTMS on depression. However, adequately controlled studies have not been conducted. METHODS: We have studied the effects of focal rTMS on the depressive symptoms in 17 patients with medication-resistant depression of psychotic subtype. The study was designed as a multiple cross-over, randomised placebo-controlled trial. Sham rTMS and stimulation of different cortical areas were used as controls. FINDINGS: Left dorsolateral prefrontal cortex rTMS resulted in a significant decrease in scores on the Hamilton depression rating scale HDRS (from 25.2 to 13.8) and the self-rated Beck questionnaire BQ (from 47.9 to 25.7). 11 of the 17 patients showed pronounced improvement that lasted for about 2 weeks after 5 days of daily rTMS sessions. No patient experienced any significant undesirable side-effects. INTERPRETATION: Our findings emphasise the role of the left dorsolateral prefrontal cortex in depression, and suggest that rTMS of the left dorsolateral prefrontal cortex might become a safe, non-convulsive alternative to electroconvulsive treatment in depression.

Adult↗
PubMed1980

Vulvo-vaginal candidosis and its treatment with the new fungicidal substance econazole.

Thirty-five patients suffering from vulvo-vaginal candidosis were treated with econazole vaginal suppositories for 3 consecutive days, on a once-a-day schedule. In 80% of the cases clinical symptoms subsided and the mycological findings became negative. No side-effects were observed or reported, and the tolerability was excellent.

Candidiasis, Vulvovaginal↗