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Biomedical subjects

J Lobo

Publications and source records attributed to J Lobo.

At least 19 recordsLinked to original sources
PubMed2006

Electronic structure of C60 on Au(887).

We present an analysis of the electronic structure of C60 adsorbed on a vicinal Au(111) surface at different fullerene coverages using photoemission, x-ray absorption, and scanning tunneling microscopy/spectroscopy (STS). STS provides a straightforward determination of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) levels with respect to the Fermi energy. At C60 coverages of 0.5 and 1 ML a 2.7 eV wide HOMO-LUMO gap is found. The near-edge x-ray absorption fine structure (NEXAFS) spectrum for the 0.5 ML C60 nanomesh structure displays a significant intensity at the low energy side of the LUMO exciton peak, which is explained as due to absorption into HOMO-LUMO gap states localized at individual C60 cluster edges. From 0.5 to 1 ML we observe a rigid shift of the HOMO-LUMO peaks in the STS spectra and an almost complete quenching of the gap states feature in NEXAFS.

Journal Article↗
PubMed2006

Observation of a Mott insulating ground state for Sn/Ge(111) at low temperature.

We report an investigation on the properties of 0.33 ML of Sn on Ge(111) at temperatures down to 5 K. Low-energy electron diffraction and scanning tunneling microscopy show that the (3x3) phase formed at approximately 200 K, reverts to a new ((square root 3)x(square root 3))R30 degrees phase below 30 K. The vertical distortion characteristic of the (3x3) phase is lost across the phase transition, which is fully reversible. Angle-resolved photoemission experiments show that, concomitantly with the structural phase transition, a metal-insulator phase transition takes place. The ((square root 3)x(square root 3))R30 degrees ground state is interpreted as the formation of a Mott insulator for a narrow half-filled band in a two-dimensional triangular lattice.

Journal Article↗
PubMed2004

Tuning the surface state dimensionality of Cu nanostripes.

Stepped Cu nanostripes with varying terrace widths are self-assembled during Ag-induced periodic faceting of vicinal Cu(111). By changing Ag coverage the average terrace size within individual Cu stripes is readily tuned, making it possible to select the one-dimensional or two-dimensional character of surface states. Furthermore, the average terrace size can be smoothly switched from 10 to 30 A, thereby tracking the transition from step-lattice, quasi-two-dimensional umklapp bands to terrace-confined one-dimensional quantum well states.

Journal Article↗
PubMed2004

Perception of severity of acute respiratory tract infections and diarrhoea in children under the age of five in rural India: utilization pattern of health services.

A cross-sectional survey of 970 children under the age of 5 in 870 households showed a biweekly incidence of acute respiratory tract infections (ARIs) and diarrhoea of 9 and 8.7%, respectively. Ninety per cent of the mothers, irrespective of their educational status, could identify correctly the severe forms of the illness. When perceived as severe the majority (75%) of them went to unqualified indigenous practitioners and only when perceived as mild did they use the government services. This shows that the user preferences for acute healthcare services vary with their perception of the illness and unqualified practitioners are the main source of healthcare providers especially in the rural areas.

Adult↗
PubMed2003

Phonon softening, chaotic motion, and order-disorder transition in Sn/Ge(111).

The phonon dynamics of the Sn/Ge(111) interface is studied using high-resolution helium atom scattering and first-principles calculations. At room temperature we observe a phonon softening at the Kmacr; point in the (sqrt[3]xsqrt[3])R30 degrees phase, associated with the stabilization of a (3x3) phase at low temperature. That phonon band is split into three branches in the (3x3) phase. We analyze the character of these phonons and find out that the low- and room-temperature modes are connected via a chaotic motion of the Sn atoms. The system is shown to present an order-disorder transition.

Journal Article↗
PubMed2000

Size-specific defensive structures in a horned weevil confirm a classic battle plan: avoid fights with larger opponents.

A rigid sheath that extends deep into the prothorax of male Parisoschoenus expositus serves to receive the horns of opponents in battles over females. The male cannot use his own horn unless he receives his opponent's horn in his sheath. The length of a male's sheath is always approximately equal to the length of his own horns, so his body design is appropriate only for horn-locking battles with males whose horns are equal to or shorter than his own. Horn length and sheath length are dimorphic with respect to each other and to an indicator of body size. The switch points between morphs are very nearly the same for several relationships, so the different aspects of fighting morphology are tightly coordinated.

Aggression↗
PubMed2000

Factors predicting the non-utilisation of immunisation services using logistic regression technique.

A cross sectional study was conducted to determine the variables which have an individual predictive power on nonutilization of immunisation services using logistic regression model. Children between 12 and 23 months of age were assessed and enrolled using a pretested interview schedule. Statistical analysis was done using descriptive statistics, univariate analysis using Chi Square tests and multivariate logistic regression analysis. Of the 200 children studied 56% were fully immunised. Only illiterate mothers (p < 0.05) and poor access (> 3 km) to health facility (p < 0.001) were found to have an independent predictive power on the nonutilization of immunisation services. Sex of the child, parity levels, socioeconomic status did not independently influence the utilisation pattern. It is possible to identify these still existing small pockets of nonusers of immunisation services through the predictive variables and target them through special efforts.

Health Services Accessibility↗
PubMed2000

Endoscopic plantar fascia release.

An anatomic exploration showed that reliable landmarks could allow a safe division of the plantar fascia. The reference line was the posterior border of the medial malleolus, 1 cm from the plantar skin. A clinical study on 53 patients (65 feet) showed that, at follow-up of over 2 years, the procedure effectively relieved heel pain in 89% of patients, morning stiffness in 92%, and allowed 71% to return to unrestricted sports activity. There were 2 complications with lateral heel pain. Patients must be properly selected, and must have had the full range of conservative treatment. Symptoms should have been intractable for approximately 1 year. In this group, good results can be expected with minimum short-term morbidity.

Adult↗
PubMed1999

[Human diphyllobothriasis by Diphyllobothrium pacificum. A new case in Antofagasta, Chile].

We report a 26 years old asymptomatic female that expelled spontaneously a 39 proglottid strobila. The taxonomic study of proglottids and eggs found in the stool examination concluded that the patient was infected by Diphyllobothrium pacificum. This infection was probably acquired by the ingestion of raw fish (Sciaena deliciosa) with lemon in a traditional plate called "cebiche". She was treated with a single dose of praziquantel in a dose of 10 mg/kg body weight. After 24 h of treatment there were no scolices on feces. The patient did not have anemia. All eight family members studied, did not have the infection. A follow up stool examination three months later remained negative.

Adult↗
PubMed1994

Assigning function to CDS through qualified query answering: beyond alignment and motifs.

In this paper, we show how to use qualitative query answering to annotate CDS-to-function relationships with confidence in the score, confidence in the tool, and confidence in the decision about the function. The system, implemented in Prolog, provides users with a powerful tool to analyze large quantities of data that have been produce by multiple sequence analysis programs. Using qualified query answering techniques, users can easily change the criteria for how tools reinforce each other and for how numbers of occurrences of particular functions reinforce each other. They can also alter how different scores for different tools are categorized.

Animals↗
PubMed1994

[Sjögren's syndrome].

This paper consists the theorical review and the current concepts of the subject and the second includes the casuistry of the Stomatology Department of the Pulido Valente Hospital. From April 1989 to 1991 (2 years), a study was made on Sjögren Syndrome (Primary and Secondary) of multiple character with the particular co-operation of the Portuguese Institute of Rheumatology. With this paper we wish to point out the importance of the oral evaluation of the study of the plurisystemic diseases as well as to establish criterions of diagnosis for the Portuguese population. Eighty cases of suspected Sjögren's Syndrome have been assessed, 66 of which have been fully. The reason for the consultation was dry mouth, dry eyes and enlargement of parotid glands. The symptoms were isolated or in association with other pathologies after other causes had been excluded. We had to establish the salivary reference values for the Portuguese population in 22 healthy volunteers. The xerostomia was evaluated by the Sialochemistry, Sialography, Cintigraphy and biopsies of the lower lip and of the sublingual gland. The ophthalmologic examination took place in the Ophthalmology Department of Santo António dos Capuchos Hospital by means of Shirmer test, Rosa Bengala and B.U.T. In spite of Sjögren's Syndrome being, up to now, so remotely determined in connection with the treatment, these patients need medical care and Stomatology plays a fundamental role as far as the diagnosis and the therapeutic points of view are concerned. We maintain the notion that the Syndrome is not as infrequent as one would believe and the evaluation of the oral field is important to establish the degree of the disease and its treatment.

Female↗
PubMed1994

Are diarrheal incidence and malnutrition related in under five children? A longitudinal study in an area of poor sanitary conditions.

This study was conducted in Atali and Garkhera villages of Faridabad district of Haryana to assess the relationship between diarrheal incidence and malnutrition. Two hundred and fifty children in the age group of 6-47 months were followed up for one year from June 1988. History of diarrheal episodes was ascertained by fortnightly home visits. Nutritional status (weight for age) of the children was assessed at the beginning of the study and at every four monthly interval. The mean diarrheal incidence was 2.88 +/- 1.28 episodes per child year. The pre-valence of moderate to severe malnutrition in the children was 35% out of which 8.8% were severely malnourished. Although severely malnourished children had 0.56 more episodes of diarrhea in a year compared to normally nourished, the difference was not statistically significant. Similarly, number of episodes of diarrhea also did not affect the subsequent nutritional status of the children. The possible reason for this could be that in areas of poor sanitary conditions, nutritional status may not play an important role in increasing the susceptibility of children to diarrhea.

Child, Preschool↗
PubMed1992

Effect of physical training on breathing pattern during progressive exercise.

It has been suggested that physical training causes a slower, deeper breathing pattern at a given level of ventilation, but there is no convincing evidence to support this. We examined breathing pattern during maximal incremental exercise on a cycle ergometer in 7 males before and after 3-4 weeks of cycle endurance training (TRAINING), and in 6 males before and after a similar period of unaltered physical activity (CONTROL); all subjects were healthy and previously sedentary. After physical training there was a significant increase in peak oxygen uptake, and significant reductions in carbon dioxide output, heart rate (fHR) and minute ventilation (VI) at submaximal workloads; peak VI was significantly increased whereas peak fHR was unchanged. At matched VI levels (moderate, moderately-high, high) the TRAINING subjects' breathing pattern was not significantly altered; there was a power of at least 80% to detect a significant (> 0.30 L) increase in tidal volume (P < 0.05) at moderately high and high ventilation levels. There was no change in the CONTROL subjects' maximal exercise performance, or breathing pattern at matched VI levels, over the same period. Short-term, activity-specific physical training does not significantly affect the breathing pattern adopted by normal humans during progressive exercise.

Adult↗
PubMed1992

Rat atrial muscle responses with caffeine: dose-response, force frequency, and postrest contractions.

Caffeine has been reported to have a positive and (or) a negative inotropic effect on cardiac muscle. In this study, the force-frequency and postrest characteristics of rat atrium were studied in the presence of caffeine (1.0-10 mM) to see if the interval between beats affected the response of cardiac muscle to caffeine. When stimulation frequency was 0.5 or 2.0 Hz, there was a positive followed by a negative inotropic response with 1, 5, or 10 mM caffeine. Incomplete relaxation occurred under these circumstances, giving rise to contracture. At low frequency of stimulation (0.1 Hz) caffeine had only a negative inotropic effect, and this effect was greater with 1 mM caffeine than with 5 mM caffeine. In the absence of caffeine, when stimulation at 0.5 or 3 Hz was interrupted, a pause of 2-20 s resulted in potentiation. When caffeine was present (2.0 mM), postrest potentiation was severely attenuated, but the steady-state contraction amplitude within the range 0.5-3.0 Hz was not different. These results are consistent with the hypothesis that caffeine induces a leak of Ca2+ from the sarcoplasmic reticulum, and this Ca2+ is extruded from the cell, possibly by Na+/Ca2+ exchange. Sarcoplasmic reticular uptake of Ca2+ and the translocation to release sites appear not to be affected by caffeine within 1-5 mM concentrations.

Animals↗
PubMed1989

Haemodialysis efficiency after long-term treatment with recombinant human erythropoietin.

In 11 chronic haemodialysis patients we investigated whether the increase in haematocrit during recombinant human erythropoietin (rHuEPO) treatment might alter the long-term efficiency of haemodialysis. After correction of anaemia with rHuEPO (mean Ht 35 +/- 2% vs 19 +/- 2% at baseline) (p 0.001), mean predialysis creatinine and urea did not change, while predialysis phosphate (1.77 +/- 0.38 vs 1.51 +/- 0.29 mmol/l) were significantly increased (p 0.01). In six of the 11 rHuEPO treated patients a post- versus pre-dialysis haemoconcentration (haematocrit 44% vs 35%) not attributable to different ultrafiltration regimes, was observed. In these 6 patients mean predialysis phosphate, creatinine and urea tended to be higher, but not significantly, in comparison to he remaining 5 patients who did not haemoconcentrate. Dialyser clearances and total extractions for urea, creatinine, phosphate and inulin were compared to those of 11 matched haemodialysis patients with anaemia. No differences were observed either for small and middle molecule clearances or their extractions between rHuEPO and anaemic patients. In conclusion, dialysis efficiency is not affected if haematocrit values are kept about 35%.

Adult↗
PubMed1989

[Polyfructosan and para-aminohippuric acid clearance, comparison of 2 methods for determining glomerular filtration and plasma renal flow].

Glomerular Filtration Rate (GFR) and Renal Plasma Flow (RPF) were measured respectively, Polyfructosan and Para-aminohippuric acid clearances, in 13 patients with different degrees of renal insufficiency. Two different methods were used, the standard method and one without urine collection. The mean GFR (66.4 +/- 27.8 vs. 72.2 +/- 19.0 ml/m, r = 0.74) and RPF (431 +/- 204 vs 490 +/- 188 ml/m, r = 0.76) as well as Filtration Fraction (17.7 +/- 8.3 vs. 16.6 +/- 6.6%) were well correlated. These data show that within the normal range of GRF and RPF the method determining only plasma levels is as reliable as the standard method, giving the advantage to be less troublesome for patients and staff, requiring no bladder catheterization.

Adult↗