All laser-assisted heteroepitaxial growth of Si0.8Ge0.2 on Si(100): Pulsed laser deposition and laser induced melting solidification

3 pages, 3 figures.The growth of heteroepitaxial Si0.8Ge0.2 films on Si(100) by a novel all laser-assisted technique using only ArF excimer laser radiation is demonstrated. Amorphous 30 nm thick films are grown by pulsed laser deposition from alternating pure Si and Ge targets on clean Si substrates. Melting and rapid solidification is then induced by pulsed irradiation (0.54 J/cm2), promoting epitaxial growth.This work has been partially supported by CICYT under project MAT93-0053 and the JNICT-CSIC agreement for traveling finances.Peer reviewe

Estudio del veneno de serpientes: tipos y tratamientos

Los venenos de las serpientes constituyen una mezcla de más de 20 polipéptidos distintos, donde se incluyen enzimas, toxinas y pequeños péptidos. Su inoculación mediante mordedura puede producir diversos tipos de intoxicación, cuyos síntomas se resumen en dos cuadros patológicos: neurotóxico y hemotóxico. La gravedad del proceso depende de factores propios del veneno, de la propia mordedura y de la presa y las lesiones, en algunos casos, pueden ser permanentes. El protocolo de actuación en caso de envenenamiento se basa en tres puntos: actuaciones de primeros auxilios (extracción del veneno, corte del riego linfático), tratamiento etiológico (administración de sueros antiofídicos) y tratamiento sintomático (farmacológico o quirúrgico).Snake venoms are mixtures of more than 20 different polypeptides where enzymes, toxins and small peptides are included. Snakes inoculate their venom during the bite and then different envenomations can occur. The symptoms are described by two pathological processes: neurotoxic and haemotoxic. The gravity of the intoxication depends on some venom, bite and catch factors and sometimes the injuries can be everlasting. When a human being is bitten by a venomous snake, three steps must be taken: first aid (venom extraction and lymphatic circulation cut) and etiological (specific anti-venom serum administration) and symptomatic (pharmacological or surgical) treatment

MINERALIZACIÓN Y/O SOLUBILIZACIÓN DEL FÓSFORO CONTENIDO EN LODOS PROVENIENTES DE RESIDUOS SALMONÍCOLAS MARINOS BIOAUMENTADOS CON CEPAS DE Aspergillus niger Y Trichoederma pseudokoningi

Se evaluó un lodo salmonícola, proveniente de centros de cultivo marinos, con el objetivo de evaluar el aumento en la mineralización y/o solubilización del fósforo del lodo salmonícola tratado con la inoculación de cepas chilenas de hongos. El lodo fue pretratado mediante esterilización, pasteurización y sin pretratar. Posteriormente, fue inoculado con cepas nativas de Aspergillus niger y Trichoderma pseudokoningii, usando dos controles: sin adición de inóculo y otro, con la cepa control A. niger ANC. Estas muestras fueron incubadas por 60 días, determinándose el pH y la disponibilidad de fósforo (P) en los lodos pretratados. Luego de esta primera fase, las muestras fueron incubadas en tubos de lixiviación a temperatura controlada durante 6 semanas evaluando la cinética de mineralización de P de los lodos. Los pretratamientos aplicados al lodo aumentaron la disponibilidad de P con la disminución del pH. La esterilización del lodo influyó en la colonización microbial, presentando la mayor colonización de las cepas inoculadas y la mayor liberación de P a la solución. El pretratamiento de esterilización inoculado con la cepa control A. niger presentó el mayor potencial de mineralización de P, siendo significativamente mayor a las cepas nativas y al control evaluado

Bose-Einstein condensation in multilayers

The critical BEC temperature $T_{c}$ of a non interacting boson gas in a layered structure like those of cuprate superconductors is shown to have a minimum $T_{c,m}$, at a characteristic separation between planes $a_{m}$. It is shown that for $a<a_{m}$, $T_{c}$ increases monotonically back up to the ideal Bose gas $T_{0}$ suggesting that a reduction in the separation between planes, as happens when one increases the pressure in a cuprate, leads to an increase in the critical temperature. For finite plane separation and penetrability the specific heat as a function of temperature shows two novel crests connected by a ridge in addition to the well-known BEC peak at $T_{c}$ associated with the 3D behavior of the gas. For completely impenetrable planes the model reduces to many disconnected infinite slabs for which just one hump survives becoming a peak only when the slab widths are infinite.Comment: Four pages, four figure

Scintillation Counters for the D0 Muon Upgrade

We present the results of an upgrade to the D0 muon system. Scintillating counters have been added to the existing central D0 muon system to provide rejection for cosmic ray muons and out-of-time background, and to provide additional fast timing information for muons in an upgraded Tevatron. Performance and results from the 1994-1996 Tevatron run are presented.Comment: 30 pages, 25 postscript figure

Resultados del tratamiento quirúrgico del dolor lumbar con instrumentación diapasón

Se presenta un estudio sobre 23 pacientes con patología lumbosacra tratados quirúrgicamente mediante artrodesis e instrumentación vertebral transpedicular tipo diapasón. El promedio de seguimiento ha sido de 25 meses (18-38). El dolor lumbar estaba relacionado en 10 casos con estenosis de canal, en 6 con espondilolistesis y en 7 con hernia discal y artrosis secundaria. Todos fueron instrumentados por vía posterior mediante fijación transpedicular y artrodesados posterolateralmente con injerto autólogo. Se consiguió una artrodesis sólida en un 96%. No se han presentado complicaciones preoperatorias. Ocho pacientes presentaron complicaciones en el postoperatorio inmediato. Observamos un desplazamiento de barra y un desanclaje del tornillo fuera del pedículo. Siguiendo los criterios de valoración de Henderson se ha conseguido un 96% de excelentes y buenos resultados.A series of 23 patient with lumbosacral pathology, surgically treated by posterior arthrodesis and vertebral diapason transpedicular fixation was retrospectively review. The average follow-up period was 25 months (18-38). The diagnosis was spinal stenosis in 10 cases, spondylolisthesis in 6, and disc herniation with secondary osteoartrhitis in 7 cases. Apart from transpedicular fixation all cases underwent posterolateral fusion with autogenous bone graft. A solid arthrodesis was achieved in a 96% of patients. There were no per-operative complication. Eight cases showed complications in the immediate postoperative period. We observed displacement of a bar and detachement of a screw out off the pedicle. According to Henderson's assessment criteria we obtained 96% of excellent and good results

Variable order Mittag-Leffler fractional operators on isolated time scales and application to the calculus of variations

We introduce new fractional operators of variable order on isolated time scales with Mittag-Leffler kernels. This allows a general formulation of a class of fractional variational problems involving variable-order difference operators. Main results give fractional integration by parts formulas and necessary optimality conditions of Euler-Lagrange type.Comment: This is a preprint of a paper whose final and definite form is with Springe

Edible films based on black chia (Salvia hispanica l.) seed mucilage containing Rhus microphylla fruit phenolic extract

Functional films based on black chia (Salvia hispanica L.) seed mucilage (BCm) containing Rhus microphylla (Rm) fruit phenolic extract were built and characterized. A hydro-alcohol extract (HAE) of Rm was incorporated as the bioactive agent due to its noteworthy phenolic profile, and good antioxidant and antifungal activities. The effects of the BCm concentration (0.2% and 0.4%, w/v), HAE incorporation, and their interaction with glycerol (1.0%, w/v) and calcium chloride (0.05%, w/v) on the films physicochemical properties were evaluated. The filmogenic solutions successfully fitted to the HerschelBulkley model (R2 0.05) changed by the HAE addition, but their surface tension was enhanced (p < 0.05), which could favor their coating ability. The polyanionic nature of the systems (zeta potential-Zp values from 26.9 to 33.3 mV) allowed them to interact with Ca2+ cations, thus forming stable and resistant films. All the films showed low water solubility (15.0% to 22.3%) and high permeability (3.7 to 4.0 × 1010 g m1 s1 Pa1), as well as high biodegradability (moisture content from 66.0% to 80.9%); although the moisture content was reduced (p < 0.05) with HAE addition. The combination of higher BCm ratio and HAE addition (BCm0.4+Rm) led to a more resistant, thick, opaque, and dark film compared with the others obtained. This study reveals the BCm-based films potential, highlighting those with HAE, representing a novel alternative to improve the quality of food products.Financial support from Universidad Autónoma Agraria Antonio Narro (UAAAN) is gratefully acknowledged by the authors. Zlatina Genisheva thanks to Foundation for Science and Technology (FCT) for the financial support (ref. SFRH/BPD/108868/2015) and to the project COMPETE 2020 (POCI-01-0145-FEDER-029145). This study was supported by FCT under the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. The authors would also like to thank to Pablo Virgen of Biocampo S.A. de C.V. and MSc Fidel Peña-Ramos from UAAAN, for their assistance during this study.info:eu-repo/semantics/publishedVersio

Boson gas in a periodic array of tubes

We report the thermodynamic properties of an ideal boson gas confined in an infinite periodic array of channels modeled by two, mutually perpendicular, Kronig-Penney delta-potentials. The particle's motion is hindered in the x-y directions, allowing tunneling of particles through the walls, while no confinement along the z direction is considered. It is shown that there exists a finite Bose- Einstein condensation (BEC) critical temperature Tc that decreases monotonically from the 3D ideal boson gas (IBG) value $T_{0}$ as the strength of confinement $P_{0}$ is increased while keeping the channel's cross section, $a_{x}a_{y}$ constant. In contrast, Tc is a non-monotonic function of the cross-section area for fixed $P_{0}$. In addition to the BEC cusp, the specific heat exhibits a set of maxima and minima. The minimum located at the highest temperature is a clear signal of the confinement effect which occurs when the boson wavelength is twice the cross-section side size. This confinement is amplified when the wall strength is increased until a dimensional crossover from 3D to 1D is produced. Some of these features in the specific heat obtained from this simple model can be related, qualitatively, to at least two different experimental situations: $^4$He adsorbed within the interstitial channels of a bundle of carbon nanotubes and superconductor-multistrand-wires Nb$_{3}$Sn.Comment: 9 pages, 10 figures, submitte

Use of social audits to examine unofficial payments in government health services: experience in South Asia, Africa, and Europe

<p>Abstract</p> <p>Background</p> <p>Unofficial payments in health services around the world are widespread and as varied as the health systems in which they occur. We reviewed the main lessons from social audits of petty corruption in health services in South Asia (Bangladesh, Pakistan), Africa (Uganda and South Africa) and Europe (Baltic States).</p> <p>Methods</p> <p>The social audits varied in purpose and scope. All covered representative sample communities and involved household interviews, focus group discussions, institutional reviews of health facilities, interviews with service providers and discussions with health authorities. Most audits questioned households about views on health services, perceived corruption in the services, and use of government and other health services. Questions to service users asked about making official and unofficial payments, amounts paid, service delivery indicators, and satisfaction with the service.</p> <p>Results</p> <p>Contextual differences between the countries affected the forms of petty corruption and factors related to it. Most households in all countries held negative views about government health services and many perceived these services as corrupt. There was little evidence that better off service users were more likely to make an unofficial payment, or that making such a payment was associated with better or quicker service; those who paid unofficially to health care workers were not more satisfied with the service. In South Asia, where we conducted repeated social audits, only a minority of households chose to use government health services and their use declined over time in favour of other providers. Focus groups indicated that reasons for avoiding government health services included the need to pay for supposedly free services and the non-availability of medicines in facilities, often perceived as due to diversion of the supplied medicines.</p> <p>Conclusions</p> <p>Unofficial expenses for medical care represent a disproportionate cost for vulnerable families; the very people who need to make use of supposedly free government services, and are a barrier to the use of these services. Patient dissatisfaction due to petty corruption may contribute to abandonment of government health services. The social audits informed plans for tackling corruption in health services.</p