117 research outputs found
Asymptotic analysis of the Gunn effect with realistic boundary conditions
A general asymptotic analysis of the Gunn effect in n-type GaAs under general boundary conditions for
metal-semiconductor contacts is presented. Depending on the parameter values in the boundary condition of
the injecting contact, different types of waves mediate the Gunn effect. The periodic current oscillation typical
of the Gunn effect may be caused by moving charge-monopole accumulation or depletion layers, or by low- or
high-field charge-dipole solitary waves. A new instability caused by multiple shedding of ~low-field! dipole
waves is found. In all cases the shape of the current oscillation is described in detail: we show the direct
relationship between its major features ~maxima, minima, plateaus, etc.! and several critical currents ~which
depend on the values of the contact parameters!. Our results open the possibility of measuring contact parameters
from the analysis of the shape of the current oscillationPeer ReviewedPostprint (published version
Asymptotic analysis of the Gunn effect with realistic boundary conditions
A general asymptotic analysis of the Gunn effect in n-type GaAs under general boundary conditions for metal-semiconductor contacts is presented. Depending on the parameter values in the boundary condition of the injecting contact, different types of waves mediate the Gunn effect. The periodic current oscillation typical of the Gunn effect may be caused by moving charge-monopole accumulation or depletion layers, or by low- or high-field charge-dipole solitary waves. A new instability caused by multiple shedding of (low-field) dipole waves is found. In all cases the shape of the current oscillation is described in detail: we show the direct relationship between its major features (maxima, minima, plateaus, etc.) and several critical currents (which depend on the values of the contact parameters). Our results open the possibility of measuring contact parameters from the analysis of the shape of the current oscillation
Accumulation of symetric dimethylarginine in hepatorenal syndrome.
In patients with cirrhosis, nitric oxide (NO), asymmetric dimethylarginine (ADMA), and possibly symmetric dimethylarginine (SDMA) have been linked to the severity of the disease. We investigated whether plasma levels of dimethylarginines and NO are elevated in patients with hepatorenal syndrome (HRS), compared with patients with cirrhosis without renal failure (no- HRS). Plasma levels of NO, ADMA, SDMA, and L-arginine were measured in 11 patients with HRS, seven patients with no-HRS, and six healthy volunteers. SDMA concentration in HRS was higher than in no-HRS and healthy subjects (1.47 6 0.25 vs. 0.38 6 0.06 and 0.29 6 0.04 lM, respectively; P , 0.05). ADMA and NOx concentrations were higher in HRS and no-HRS patients than in healthy subjects (ADMA, 1.20 6 0.26, 1.11 6 0.1, and 0.53 6 0.06 lM, respectively; P , 0.05; NOx, 94 6 9.1, 95.5 6 9.54, and 37.67 6 4.62 lM, respectively; P , 0.05). In patients with HRS there was a positive correlation between serum creatinine and plasma SDMA (r2¼0.765, P , 0.001) but not between serum creatinine and ADMA or NOx. The results suggest that renal dysfunction is a main determinant of elevated SDMA concentration in HRS. Accumulation of ADMA as a result of impaired hepatic removal may be the causative factor initiating renal vasoconstriction and SDMA retention in the kidney. Exp Biol Med 231:7075, 200
Primary Intraosseous Carcinoma and Odontogenic Cyst : Three new cases and review of the Literature
Introduction: The Odontogenic Primary Intraosseous Carcinoma (PIOC) are a rare group of malignant tumours with strict clinic and anatomy pathological diagnosis criteria. The different classification suggested for these tumours and the small amount of cases described in literature makes it hard to know exactly how many of the cases published until now are real. Material and methods: We present three new cases of PIOC originated from a previous cystic lesion that where treated in our Hospital. Two of them in the posterior jaw region where is more frequent, and the third in the upper jaw. We explain the procedure we used in each case and the aesthetic-functional reconstruction used witches are two fibula osseomiocutaneous free flaps and a bone graft of iliac crest and further placing of implants. The classification, the clinical and radiological diagnosis, the treatment and its survival are discussed. Results: in all three cases we were able to see in the anatomy pathological study an epithelial, exclusively without surrounding oral mucosa affectation or tissues near the lesion as well as the lack of tumorous pathology in other parts of the body. One of the patients died because of premature massive cervical recidiva while the other two patients are currently free form illness, for ten years one of them and fifteen months the other. Conclusions: the anatomy pathological study of all of the lesions of cystic characteristics at jaw level is very important because of the risk of coexisting with carcinomatous cells. The treatment of these tumours consists in practising aggressive surgery and, in some cases, radio and/or chemotherapy post intervention
Nikkei: japanese diaspora through comic
Nikkei es el término con que se denomina a los japoneses que se han ido de su país por
trabajo y a sus descendientes. Posiblemente esta sea la faceta menos conocida del
pueblo nipón, ya que el estereotipo en torno a esta nacionalidad nos dice que son
poco dados a relacionarse con foráneos, y menos a vivir en el extranjero.
Posiblemente el peso de la cerrazón a influencias extranjeras del Periodo Edo (24 de
marzo de 1603 - 3 de mayo de 1868) tiene mucho que ver con esta percepción.
No pocos cómics han tratado el tema desde diferentes perspectivas. Sin
embargo, tan solo unos cuantos han profundizado en la situación de los emigrantes
japoneses en el extranjero. En este trabajo se va a analizar precisamente dicha
condición humana a través de estas tres obras: El manga de los cuatros inmigrantes
(1931), de Henry Yoshitaka Kiyama; Casualmente (2014), de Fumio Obata; y Monster
(1999-2002), de Naoki Urasawa, las cuales ofrecen perspectivas diferentes de los
nikkei. No obstante, para ello, también se realizará una aproximación terminológica a
los diferentes conceptos relacionados con tal condición y se repasará la historia de las
migraciones niponas
Recomendación para la determinación de HER2 en cáncer de mama : Consenso nacional de la sociedad española de anatomía patológica (SEAP) y de la sociedad española de oncología médica (SEOM)
La identificación de los carcinomas de mama con amplificación/sobreexpresión de HER2 es crítica en la práctica clínica diaria ya que estas neoplasias requieren un tratamiento específico que incluye el uso de terapias dirigidas. Tanto las técnicas de hibridación in situ como las técnicas inmunohistoquímicas son métodos apropiados para la identificación de cánceres de mama HER2 positivos. Sin embargo, numerosos estudios, incluidos los desarrollados por la Asociación para la Garantía de Calidad en Patología de la SEAP (AGCP) y la experiencia de centros de referencia nacionales en la determinación de HER2 han puesto de manifiesto importantes problemas de reproducibilidad entre laboratorios. Por estos motivos, patólogos expertos en la determinación de HER2 de estos centros de referencia, así como oncólogos médicos con una contrastada actividad en cáncer de mama, en representación de las sociedades respectivas (SEAP y SEOM), han trabajado para debatir y consensuar las recomendaciones nacionales de determinación de HER2. Estas recomendaciones se basan no sólo en la experiencia de los participantes en el consenso, sino también en la experiencia internacional publicada en recientes guías de distintos países, tales como Estados Unidos, Reino Unido y Canadá.
En este consenso, se recomiendan los requisitos mínimos que un laboratorio de Anatomía Patológica debe cumplir para garantizar la adecuada determinación de HER2 en la práctica diaria. Aquellos laboratorios que carezcan de los estándares mínimos expuestos en esta guía deberían trabajar en alcanzarlos y durante este proceso remitir a laboratorios de referencia las muestras en las que la determinación de HER2 tenga implicaciones clínicas para las pacientes.Breast cancers with HER2 alterations are critical to identify because such tumors require unique treatment, including the use of targeted therapies. HER2 alterations at the DNA (amplification) and protein (overexpression) level usually occur in concert, and both in situ hybridization and immunohistochemistry can be accurate methods to assess these alterations. However, recent studies including those conducted by the Association for Quality Assessment of the Spanish Society of Pathology and the experience of several national reference centres for HER2 testing have suggested that serious reproducibility issues exist with both techniques. To address this, a joint committee of both the Spanish Society of Pathology and the Spanish Society of Medical Oncology has met to review guidelines for HER2 testing. Consensus recommendation are based not only on panellist’s experience but also in those consensus guidelines previously reported in several countries, such as United Stated, United Kingdom and Canada.
These guidelines include minimal requirements that Pathology Department must meet in order to guarantee appropriate HER2 testing in breast cancer. Pathology laboratories that do not meet these standards must put effort to reach them and, in the meantime, send clinical cases to reference centres.Vera Sempere, Fco Jose, [email protected] ; Lluch Hernandez, Ana, [email protected]
Lemierre Syndrome associated with dental infections : report of one case and review of the literature
The first publication on Lemierre Syndrome appears in 1936 by Lemierre. It is defined as an ?oropharynx bacterial infection characterized by the thrombophlebitis in the internal jugular vein, derived in a systemic septic embolism?. In 81% of the cases, the Fusobacterium necrophorum is the most frequent etiologic agent. Fever is the most common symptom, but it can depending on the primary infection, tonsillitis, mastoiditis or odontogenic infection. According to the literature the mortality is very low, but with a significant morbidity, that is why the diagnosis and early treatment is very important. The diagnosis it´s clinical, even though the CT scan and other diagnosis methods (echography, MRI) help to determine the extent of the infection. It?s necessary to administrate the antibiotics endovenous at high dose, (keeping in mind that the most frequent micro organism is anaerobic), and vital support measures if neccessary. We present a case report of Lemierre Syndrome associated to an odonthogenic infection caused by the 4.8 molar
Nursing intervention to improve positive mental health and self-care skills in people with chronic physical health conditions
The exponential increase in the number of people suffering chronic illness has become a problem for which healthcare services need a response. The inclusion of self-care and positive mental health as part of a strategy to promote health offers an opportunity for a reorganization oriented towards community spaces and group interventions. This study undertook the assessment of an intervention designed to optimize the agency of and capacity for self-care and positive mental health by utilizing activities drawn from the Nursing Intervention Classification (NIC), specifically from Field 3 (Behavioral), and organized as a program called PIPsE. A quasi-experimental design was prepared with an intervention group (n = 22) and a control group (n = 22), in a primary care center in the Barcelona metropolitan area. The instruments used were two ad hoc questionnaires to collect sociodemographic and satisfaction information and two scales: the Appraisal of Self-care Agency Scale (ASA) and the Positive Mental Health Questionnaire (PMHQ). The results obtained showed a significant increase in self-care capacity and both overall positive mental health and mental health by factors in the intervention group
Effectiveness of the online 'Dialogue Circles' nursing intervention to increase positive mental health and reduce the burden of caregivers of patients with complex chronic conditions. Randomized clinical trial
The personal demands involved in caring for a chronically ill person can lead to emotional and physical exhaustion in caregivers. The aim of this study was to evaluate the effectiveness of an online nursing intervention called 'dialogue circles' designed to reduce caregiver overload and enhance positive mental health (PMH) in family caregivers. We used a pre-post design. The sample consisted of 86 family caregivers of patients with complex chronic conditions, randomly assigned to the intervention group (n = 43) or the control group (n = 43). All participants completed the Zarit scale and the Positive Mental Health Questionnaire 15 days before starting the intervention and 30 days after its completion. Comparison of the post-test changes revealed statistically significant differences between the two groups in PMH and overload, with the intervention group showing greater positive changes in all dimensions of PMH after the intervention and lower scores on overload. In conclusion, the results suggest that incorporating dialogue circles as an online nursing intervention in the caregivers of patients with complex chronic conditions can enhance PMH and decrease caregiver overload, especially in settings where face-to-face encounters are not possible
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