Quantum normal-to-inhomogeneous superconductor phase transition in nearly two-dimensional metals

In multi-band systems, electrons from different orbitals coexist at the Fermi surface. An attractive interaction among these quasi-particles gives rise to inter-band or hybrid pairs which eventually condense in a superconducting state. These quasi-particles have a natural mismatch of their Fermi wave-vectors, $\delta k_F$, which depends on the strength of the hybridization between their orbitals. The existence of this natural scale suggests the possibility of inhomogeneous superconducting ground states in these systems, even in the absence of an applied magnetic field. Furthermore, since hybridization $V$ depends on pressure, this provides an external parameter to control the wave-vectors mismatch at the Fermi surface. In this work, we study the phase diagram of a two-dimensional, two-band metal with inter-band pairing. We show that as the mismatch between the Fermi wave-vectors of the two hybrid bands is reduced, the system presents a normal-to-inhomogeneous superconductor quantum phase transition at a critical value of the hybridization $V_c=\Delta_0$. The superconducting ground state for $V<V_c$ is characterized by a wave-vector with magnitude $|\mathbf{q}_c|=q_c=2 \Delta_0/\bar{v}_f$. Here $\Delta_0$ is the superconducting gap in the homogeneous state and $\bar{v}_f$ the average Fermi velocity. We discuss the nature of the quantum critical point (QCP) at $V_c$ and obtain the associated quantum critical exponents.Comment: 6 pages, 4 figure

Efficacy and Safety of Direct-Acting Oral Anticoagulants Use in Acute Portal Vein Thrombosis Unrelated to Cirrhosis

In acute portal vein thrombosis (APVT) unrelated to cirrhosis, anticoagulant therapy is classically started with low molecular weight heparin or vitamin K antagonists. New direct-acting oral anticoagulants (DOACs) are used in the treatment of venous thrombosis outside the splanchnic vascular bed, but not in the latter. We report a young female with APVT occurring in a non-cirrhotic liver linked to heterozygosity of factor V-Leiden and prothrombin G20210A gene mutations. Rivaroxaban was started, with total recanalization of the left and partial recanalization of the right portal vein branches, without complications. New DOACs do not need daily subcutaneous injections nor routinely blood coagulation control tests, making its use attractive, eventually increasing patient's compliance. If proved to be safe and effective in the future studies, its use may be extended to PVT treatment. This case shows that rivaroxaban was safe, not only prevented the extension of thrombosis in the portal tract, but also resolved PVT, at least partially.info:eu-repo/semantics/publishedVersio

Effects of varying ruminally undegradable protein supplementation on forage digestion, nitrogen metabolism, and urea kinetics in Nellore cattle fed low-quality tropical forage

Citation: Batista, E. D., Detmann, E., Titgemeyer, E. C., Valadares, S. C., Valadares, R. F. D., Prates, L. L., . . . Paulino, M. F. (2016). Effects of varying ruminally undegradable protein supplementation on forage digestion, nitrogen metabolism, and urea kinetics in Nellore cattle fed low-quality tropical forage. Journal of Animal Science, 94(1), 201-216. doi:10.2527/jas2015-9493Effects of supplemental RDP and RUP on nutrient digestion, N metabolism, urea kinetics, and muscle protein degradation were evaluated in Nellore heifers (Bos indicus) consuming low-quality signal grass hay (5% CP and 80% NDF, DM basis). Five ruminally and abomasally cannulated Nellore heifers (248 +/- 9 kg) were used in a 5 x 5 Latin square. Treatments were the control (no supplement) and RDP supplementation to meet 100% of the RDP requirement plus RUP provision to supply 0, 50, 100, or 150% of the RUP requirement. Supplemental RDP (casein plus NPN) was ruminally dosed twice daily, and RUP supply (casein) was continuously infused abomasally. Jugular infusion of [(NN)-N-15-N-15]-urea with measurement of enrichment in urine was used to evaluate urea kinetics. The ratio of urinary 3-methylhistidine to creatinine was used to estimate skeletal muscle protein degradation. Forage NDF intake (2.48 kg/d) was not affected (P >= 0.37) by supplementation, but supplementation did increase ruminal NDF digestion (P < 0.01). Total N intake (by design) and N retention increased (P < 0.001) with supplementation and also linearly increased with RUP provision. Urea entry rate and gastrointestinal entry rate of urea were increased by supplementation (P < 0.001). Supplementation with RUP linearly increased (P = 0.02) urea entry rate and tended (P = 0.07) to linearly increase gastrointestinal entry rate of urea. Urea use for anabolic purposes tended (P = 0.07) to be increased by supplementation, and RUP provision also tended (P = 0.08) to linearly increase the amount of urea used for anabolism. The fraction of recycled urea N incorporated into microbial N was greater (P < 0.001) for control (22%) than for supplemented (9%) heifers. Urinary 3-methylhistidine: creatinine of control heifers was more than double that of supplemented heifers (P < 0.001). Control heifers reabsorbed a greater (P < 0.001) fraction of urea from the renal tubule than did supplemented heifers. Overall, unsupplemented heifers had greater mobilization of AA from myofibrillar protein, which provided N for urea synthesis and subsequent recycling. Supplemental RUP, when RDP was supplied, not only increased N retention but also supported increased urea N recycling and increased ruminal microbial protein synthesis

Cobertura vegetal e uso da terra nos solos arenosos das áreas de afloramento do Sistema Aquífero Urucuia-Brasil.

O Sistema Aquífero Urucuia (SAU) é um reservatório subterrâneo de água doce que contribui significativamente para a manutenção das vazões do Rio São Francisco e seus afluentes. Situa-se em uma área do Bioma Cerrado considerada como a nova ?fronteira agrícola nacional?, onde ocorrem vários meses anuais de estiagem, e a presença de água subterrânea tem estimulado o uso desta para suprir a crescente demanda na região, principalmente para a irrigação de culturas agrícolas produzidas com altos níveis tecnológicos. O solo influencia na manutenção da qualidade e da quantidade das águas subterrâneas, pelo que é necessária a proteção das áreas de recarga de aquíferos, evitando contaminação decorrente da ocupação com atividades antrópicas, bem como o comprometimento de sua recarga. Este trabalho analisou características da cobertura vegetal e uso da terra nos solos arenosos das áreas de afloramento do Sistema Aquífero Urucuia, contribuindo para a identificação de áreas com maior vulnerabilidade ambiental e potencial de contaminação de águas subterrâneas deste sistema. Solos arenosos representam 45,33% das áreas de afloramento do SAU. De acordo com o Projeto MapBiomas, em 2018, 93,08% dos solos arenosos do SAU apresentavam cobertura vegetal de origem natural: 46,30% com ?Formação savânica?, 42,11% com campo natural e 4,61% com ?Cerradão?. Também havia categorias de uso antrópico: 212.138 ha dos solos arenosos com culturas agrícolas, 145.256 ha com pastagem plantada, 8.284 ha com florestas plantadas, 311 ha com infraestrutura urbana e 1,31 ha com mineração. Nesta região, 84,77% da área do SAU situada em Unidades de Conservação (UCs) de proteção integral e 59,25% da situada em UCs de Uso Sustentável apresenta solos arenosos. De uma forma geral, nestas UCs predomina cobertura vegetal natural, mas há áreas de solos arenosos dentro de UCs de Proteção Integral com atividades de origem antrópica, ao contrário do que é estabelecido para esta categoria de UC no Sistema Nacional de Unidades de Conservação ? SNUC. Assim, a área relativa de solos arenosos do SAU com uso antrópico direto é de praticamente 400 mil ha (399.264 ha) de um total de 5.768.983 ha, sendo importante a adoção de práticas conservacionistas sustentáveis nessa região. Adicionalmente, a efetiva proteção de áreas situadas em unidades de conservação demanda a regularização fundiária, bem como estímulos econômicos e fiscalização ambiental efetiva, num momento em que há incentivos nacionais de expansão das áreas agrícolas e tendência de aumento da demanda pelo uso de água de qualidade na região.ODS-6

Supplementation levels for growing beef cattle grazing in the dry-rainy transition season.

The objective of this experiment was to study the effects of different levels of supplementation on the performance, intake, digestibility, pH and rumen ammonia concentration in growing bulls grazing Brachiaria decumbens Stapf. pasture, during the dry-rainy transition season. For evaluation of performance, intake and digestibility, it was used 25 non-castrated steers at 11 months of age and initial average body weight of 270 kg, grouped in five plots of five animals each, following a completely randomized design. Each plot received one of the following feeding treatments: mineral mixture and supplement at the proportion of 0.5, 1.0, 1.5 and 2.0 kg/animal/day, corresponding to 0.18, 0.36, 0.54 and 0.72% of the average body weight of the animals. The area designated for the animals was constituted of five 2.0-ha paddocks. For the evaluation of the pH and rumen ammonia concentration, five crossbred non-castrated steers were used, with average body weight of 240 kg, fistulated in the esophagus, rumen and abomasum, disposed in a 5 × 5 Latin square, with five treatments and five experimental periods. Animal performance behaved in a positive linear manner according to the supplementation levels, responding with an increase of more than 80% on weight gains of the animals. Intakes of total and pasture dry matter (DM), organic matter and neutral detergent fiber were not influenced by supplementation. Intakes of crude protein, nonfibrous carbohydrates, ether extract and total digestible nutrients as well as nutrient digestibility and rumen ammonia concentration showed a positive linear pattern in response to supplementation levels. Increasing levels of concentrate supplementation influence positively the performance of bulls growing on pastures during the dry-rainy transition season