Measuring the Berry phase of graphene from wavefront dislocations in Friedel oscillations.

Electronic band structures dictate the mechanical, optical and electrical properties of crystalline solids. Their experimental determination is therefore crucial for technological applications. Although the spectral distribution in energy bands is routinely measured by various techniques1, it is more difficult to access the topological properties of band structures such as the quantized Berry phase, γ, which is a gauge-invariant geometrical phase accumulated by the wavefunction along an adiabatic cycle2. In graphene, the quantized Berry phase γ = π accumulated by massless relativistic electrons along cyclotron orbits is evidenced by the anomalous quantum Hall effect4,5. It is usually thought that measuring the Berry phase requires the application of external electromagnetic fields to force the charged particles along closed trajectories3. Contradicting this belief, here we demonstrate that the Berry phase of graphene can be measured in the absence of any external magnetic field. We observe edge dislocations in oscillations of the charge density ρ (Friedel oscillations) that are formed at hydrogen atoms chemisorbed on graphene. Following Nye and Berry6 in describing these topological defects as phase singularities of complex fields, we show that the number of additional wavefronts in the dislocation is a real-space measure of the Berry phase of graphene. Because the electronic dispersion relation can also be determined from Friedel oscillations7, our study establishes the charge density as a powerful observable with which to determine both the dispersion relation and topological properties of wavefunctions. This could have profound consequences for the study of the band-structure topology of relativistic and gapped phases in solids.

Cyclonic and anticyclonic rotation in a cylinder cooled inhomogeneously on the top.

In this work, we study the development of vortical structures generated in a rotating cylinder non-homogeneously cooled on the top. In the axisymmetric regime, for moderate vertical temperature differences and any rotation rate, cyclonic and anticyclonic rotations coexist in the flow: a counterclockwise motion at upper levels, giving place to a vertical top-down vortex, and a clockwise rotation at lower levels that generates a spin up motion. For lower rotation rates and high enough vertical temperature differences, only cyclonic top-down vortices survive and get stronger. We perform a force balance analysis to explain the phenomena. In the non-axisymmetric regime, no anticyclonic rotation at the bottom is reported and the cyclonic top-down vortex either disappears or splits up in two top-down vortices, depending on the ambient rotation rate. The intensity of the cooling on the top and how localized this cool region is affect the flow developed. When the horizontal temperature difference on the top is larger than the vertical temperature difference between top and bottom, stable axisymmetric top-down vortices with an inner updraft of warmer air are reported. The more localized the cooling above, the more difficult the development of the inner updraft becomes. Results may contribute to the understanding of the relevance of thermal processes in tornadogenesis.

Thermoconvective vortices in a cylindrical annulus with varying inner radius.

This paper shows the influence of the inner radius on the stability and intensity of vertical vortices, qualitatively similar to dust devils and cyclones, generated in a cylindrical annulus non-homogeneously heated from below. Little relation is found between the intensity of the vortex and the magnitude of the inner radius. Strong stable vortices can be found for both small and large values of the inner radius. The Rankine combined vortex structure, that characterizes the tangential velocity in dust devils, is clearly observed when small values of the inner radius and large values of the ratio between the horizontal and vertical temperature differences are considered. A contraction on the radius of maximum azimuthal velocity is observed when the vortex is intensified by thermal mechanisms. This radius becomes then nearly stationary when frictional force balances the radial inflow generated by the pressure drop in the center, despite the vortex keeps intensifying. These results connect with the behavior of the radius of the maximum tangential wind associated with a hurricane.

Analysis of invasive diagnostic techniques for pathological confirmation of pleural mesothelioma.

BACKGROUND AND OBJECTIVES: Mesothelioma is an infrequent neoplasm with a poor prognosis that is related to exposure to asbestos and whose peak incidence in Europe is estimated from 2020. Its diagnosis is complex; imaging techniques and the performance of invasive pleural techniques being essential for pathological confirmation. The different diagnostic yields of these invasive techniques are collected in the medical literature. The present work consisted of reviewing how the definitive diagnosis of mesothelioma cases in our centre was reached to check if there was concordance with the data in the bibliography. MATERIALS AND METHODS: Retrospective review of patients with a diagnosis of pleural mesothelioma in the period 2019-2021, analysing demographic data and exposure to asbestos, the semiology of the radiological findings and the invasive techniques performed to reach the diagnosis. RESULTS: Twenty-six mesothelioma cases were reviewed. 22 men and 4 women. Median age 74 years. 9 patients had a history of asbestos exposure. Moderate-severe pleural effusion was the most frequent radiological finding (23/26). The sensitivity of the invasive techniques was as follows: Cytology 13%, biopsy without image guidance 11%, image-guided biopsy 93%, surgical biopsy 67%. CONCLUSIONS: In our review, pleural biopsy performed with image guidance was the test that had the highest diagnostic yield, so it should be considered as the initial invasive test for the study of mesothelioma.

Unraveling the intrinsic and robust nature of van Hove singularities in twisted bilayer graphene by scanning tunneling microscopy and theoretical analysis.

Extensive scanning tunneling microscopy and spectroscopy experiments complemented by first-principles and parametrized tight binding calculations provide a clear answer to the existence, origin, and robustness of van Hove singularities (vHs) in twisted graphene layers. Our results are conclusive: vHs due to interlayer coupling are ubiquitously present in a broad range (from 1° to 10°) of rotation angles in our graphene on 6H-SiC(000-1) samples. From the variation of the energy separation of the vHs with the rotation angle we are able to recover the Fermi velocity of a graphene monolayer as well as the strength of the interlayer interaction. The robustness of the vHs is assessed both by experiments, which show that they survive in the presence of a third graphene layer, and by calculations, which test the role of the periodic modulation and absolute value of the interlayer distance. Finally, we clarify the role of the layer topographic corrugation and of electronic effects in the apparent moiré contrast measured on the STM images.

Effects of thermal gradients on the intensity of vortices generated in a cylindrical annulus.

This paper shows the influence of horizontal and vertical temperature gradients on the intensity of vertical vortices, qualitatively similar to dust devils, generated by a convective instability in a cylindrical annulus non-homogeneously heated. The behavior of the vortices formed is studied, showing that the increase of the temperature gradients intensifies the strength of the vortical structures developed and vice versa, small horizontal and vertical temperature gradients lead to weaker vortices or even make them disappear. Consequently, the intensity of the vortices can be controlled thermally by cooling or heating adequately the bottom boundary.

Rhabdomyolysis in a patient with McArdle's disease. / Rabdomiólisis en un paciente con enfermedad de McArdle.

INTRODUCTION: McArdle's disease or glycogenosis type V is a rare disease due to deficiency of muscle myophosphorylase leading to inability to degrade glycogen at this level. Patients have fatigue, pain, and cramps on a regular basis. In addition, after intense exercise or stressful situation, they are exposed to cellular lysis. This can occur in the form of rhabdomyolysis and myoglobinuria, a potentially serious clinical syndrome if not treated quickly. CASE EVALUATION: We present the care plan of a 38-year-old man with McArdle's disease and secondary rhabdomyolysis on physical exercise, which required attention in the Emergency Department for 24 hours, as well as his subsequent admission to the ward. A nursing evaluation was performed following the care model of Virginia Henderson. DIAGNOSIS: Priority was given to nurse diagnoses: (00016) deterioration of urinary elimination, (00092) activity intolerance, (00093) fatigue and (00132) acute pain; and potential complication: risk of acute renal failure. PLANNING: The Care Plan is developed following the NANDA-NIC-NOC methodology, with special attention to alterations in the elimination and musculoskeletal system. The diuresis is monitored. Fluid replenishment is performed, and analgesic medication is given. DISCUSSION: There is little literature on the nursing care of patients with McArdle's disease, which has limited the comparison of our results with those of other authors. However, given the good response of the subject through fluid replacement, optimal pain control and rest, they made a rapid recovery.

[Efficacy of hydrotherapy versus gym treatment in primary total knee prosthesis due to osteoarthritis: a randomized controlled trial].

BACKGROUND: Physiotherapy is postulated as an effective treatment after total knee arthroplasty (TKA). The objective of the study was to assess the efficacy of hydrotherapy versus gym kinesitherapy during the second phase of treatment in TKA patients, with regard to the improved gait test, pain, stiffness, joint balance, muscle strength and inflammation. METHODS: A controlled and randomized trial was carried out. TKA patients received a first rehabilitative phase (15 60-minutes sessions) at the gym. In the second phase (15 40-minute sessions), one group performed physiotherapy in a gym and another in a swimming pool. Different variables were assessed (basal, after 15 and after 30 ses-sions): functional capacity, pain and stiffness with WOMAC index, joint balance with goniometer; muscle strength with Lovett scale, and result of 6-minute gait test. RESULTS: A total of 115 patients participated, 59 (51.3%) in the gym group and 56 (48.7?%) in the pool group. After the second phase of re-habilitation, higher clinical improvements were observed in the pool group, with statistically significant differences in pain (p?=?0.005), stiffness (p?=?0.010), joint balance (p?=?0.027) and muscle strength (p?=?0.049) in the operated knee, and in the result of the 6-minute gait test (p?=?0.002). CONCLUSIONS: In TKA patients, hydrotherapy during the second phase of rehabilitative treatment was more effective than gym physiother-apy in terms of improved pain, stiffness, joint balance, muscle strength and gait testing.

Generation of a magnetic field by a double vortex in a rotating cylinder.

In this paper we use simulations of the magnetohydrodynamic equations coupled with heat to show the generation of magnetic field by the dynamical interaction of a pair of vortices in a fluid electrically conducting within a cylindrical domain nonhomogeneously heated from below, setting in a rotation frame. For large enough rotation rates we show that the formation of a pair of vortices inside the primary whirl gives rise to a magnetic field. The magnetic field has a strong horizontal component, and the magnetic lines go from one vortex to the other.

Effects of optimal control over thermoconvective patterns.

This paper shows that optimal control techniques can be used to avoid some pattern formation in a Rayleigh-Bénard problem with horizontal temperature gradient. Appropriate thermal boundary conditions determined by these techniques lead to new strong controlled basic states with reduced pattern and for which the thermoconvective instability is avoided.

[Childhood cholelithiasis in a district hospital]. / Colelitiasis en la infancia en un Hospital de Area.

Cholelithiasis is a rare finding in children, even though recent series show increased detection of this disease. A retrospective study was performed in children with a diagnosis of cholelithiasis between 1993 and 2005 in the Reina Sofia Hospital in Tudela (Spain). Eighteen patients with cholelithiasis and three with biliary sludge were detected. Predisposing factors for cholelithiasis were prematurity and parenteral nutrition (one patient), sepsis (two patients), obesity (one patient), and a family history of the disease (one patient). The disease was idiopathic in 11 patients. Gallstones were detected in two patients presenting with appendicular symptoms. One child with biliary sludge had received treatment with ceftriaxone as a predisposing factor. All patients were diagnosed by ultrasound. Plain abdominal X-ray detected lithiasis in 12 of the 15 patients (80 %) with cholelithiasis who underwent this procedure. The most frequent symptoms were abdominal pain (seven patients), abdominal pain and vomiting (five patients), and diarrhea (one patient). Two patients presented with appendicular symptoms. Fourteen patients underwent surgery (open cholecystectomy in two and laparoscopic cholecystectomy in 12). None of the patients required emergency surgery. Cholelithiasis in children is an unusual finding, but is not exceptional and is associated with nonspecific symptoms. Plain abdominal X-ray is useful in diagnosis but the main diagnostic technique is ultrasonography.

Evolution of secondary whirls in thermoconvective vortices: Strengthening, weakening, and disappearance in the route to chaos.

The appearance, evolution, and disappearance of periodic and quasiperiodic dynamics of fluid flows in a cylindrical annulus locally heated from below are analyzed using nonlinear simulations. The results reveal a route of the transition from a steady axisymmetric vertical vortex to a chaotic flow. The chaotic flow regime is reached after a sequence of successive supercritical Hopf bifurcations to periodic, quasiperiodic, and chaotic flow regimes. A scenario similar to the Ruelle-Takens-Newhouse scenario is verified in this convective flow. In the transition to chaos we find the appearance of subvortices embedded in the primary axisymmetric vortex, flows where the subvortical structure strengthens and weakens, that almost disappears before reforming again, leading to a more disorganized flow to a final chaotic regime. Results are remarkable as they connect to observations describing formation, weakening, and virtual disappearance before revival of subvortices in some atmospheric swirls such as dust devils.

Bifurcation diversity of dynamic thermocapillary liquid layers.

We study, from the theoretical point of view, instabilities appearing in a liquid layer, where a dynamic flow is imposed through a nonzero temperature gradient at the bottom. Experimentally many interesting dynamical behaviors have been discovered in this system. In this Brief Report we prove that the basic solution can display great richness of bifurcations which are controlled by heat related parameters. Different kinds of spatially extended and localized structures appear, which are both stationary or oscillatory. These last ones can present amazing patterns such as squares or spirals. Also competing solutions at codimension-two bifurcation points have been found: stationary radial rolls with different wave numbers, radial rolls with hydrothermal waves, and hydrothermal waves with different wave numbers. Remarkably our results recover many features of numerous reported experiments, predict new instabilities, and by giving a deeper insight into how physical parameters contribute to bifurcations, open a gateway to control those instabilities.

[Arachnoid metastasis of renal cell carcinoma: review of forms of tumor dissemination and review of its metastasis in the nervous system]. / Metástasis aracnoideas de un carcinoma de células renales: repaso de formas de diseminación del tumor y revision de sus metastásis en el sistema nervioso.

Contribution of one case of renal cells carcinoma, in an adult man, that during evolution developed arachnoid metastasis. The patient was first seen for a brain haemorrhage due to a bleeding metastasis. In later studies, a renal cells carcinoma was found to be the primary site of the brain condition. The evolution showed neurological manifestations in the limbs, and the arachnoid metastasis was detected. The paper includes imaging studies of the referred disease both al brain, renal and spinal level with CT and NMR studies. A revision is made of the different dissemination forms of renal cells tumours, as well as a review of the existing literature with regard to the nervous system metastasis. No case has been found in this review relative to spinal arachnoid dissemination.

[Pruritus in chronic kidney insufficiency]. / Prurito en la insuficiencia renal crónica.

Itching is the dermatologic symptom more often found in patients with chronic renal failure. We have studied 80 patients with end-stage renal disease; itching was present in 56.3% of the cases. We didn't detected in this study any correlation between itching, long term hemodialysis, high calcium, phosphorus, alkaline phosphatase or phosphocalcic product levels. We have seen: 1. Those patients with itching were older than the rest. 2. Itching was important in those patients with residual diuresis less than 500 ml/day (p greater than 0.01). 3. Those men without itching had higher hematocrit levels (p greater than 0.01). 4. Histologic findings on optic and electronic microscopy were more frequent in patients who presented this symptom.

Top-down vortices developed in a cylindrical annulus cooled on the top.

In this paper we study the generation of top-down vortices by thermoconvective mechanisms in a cylindrical annulus nonhomogeneously cooled on the top. Assuming axisymmetry we study the structure of the vortices, characterized by a spiral downward motion, similar to that observed in tornadoes generated in supercell storms.

[Nephrotoxicity due to iodine contrasts in computerized tomography studies of diabetic outpatients on metformin]. / Nefrotoxicidad por contrastes yodados en estudios de tomografía computarizada a pacientes ambulatoriso diabéticos en tratamiento con metformina.

BACKGROUND: To determine the incidence of contrast-induced nephropathy (CIN) among diabetic patients treated with Metformin who underwent computerized tomography (CT) scan with iodinated contrast media. METHODS: Prospective study of diabetic patients enrolled in a lactic acidosis prevention protocol in whom clinical and analytical follow up after CT scan with intravenous contrast was performed. RESULTS: In this study, 98 cases were collected. The incidence of CIN in diabetic patients without prior renal failure was 0%. In patients with previous renal failure the incidence of CIN was 4.7%. CONCLUSIONS: The risk of CIN in diabetic patients with no renal failure undergoing intravenous contrast administration is minimal. Recommendations to stop Metformin to avoid lactic acidosis in patients undergoing intravenous contrast administration may be restricted to patients with abnormal renal function.

Model of lymphoma from stochastic analysis.

In this work, the authors introduce a stochastic model of lymphoma. Two clonotypes of T cells of the immune system compete with each other and with other clonotypes for survival stimuli. One of the clonotypes is normal and the other is tumourous. To model the tumourous clonotype the authors include a rate of influx of new naive T cells (descendants of mutated precursor cells) from the thymus. The authors obtain a deterministic approximation to the stochastic model and analyse eight cases of competition between the two clonotypes of T cells. The authors obtain two possible scenarios, depending on the values of parameters: either both clonotypes survive in the repertoire or the clonotype of the normal T cells becomes extinct, meanwhile the clonotype of the tumourous T cells is maintained, after achieving some maximum level of growth. The authors show that if the income of the new tumourous T cells from the thymus is augmented, then the tumourous clonotype, would never be removed from the repertoire; meanwhile the normal clonotype could become extinct if it was not specialised enough to compete effectively for survival stimuli provided by professional cells.