► Non-resonant detection of THz radiation using s-Si MODFETs at room temperature. ► Terahertz imaging by using strained-silicon MODFETs as sensors. ► Low temperature resonant detection of THz ...radiation emitted by s-Si MODFETs.
We report on non-resonant (broadband) and resonant detection of terahertz radiation using strained-Si modulation doped field effect transistors. The devices were excited at room temperature by two types of terahertz sources (an electronic source based on frequency multipliers at 0.292THz and a pulsed parametric laser at 1.5THz). In both cases, a non-resonant response with maxima around the threshold voltage was observed. Shubnikov-de Haas and photoresponse measurements were performed simultaneously and showed a phase-shift of π/2 in good agreement with the theory, which demonstrates that the observed response is related to the plasma waves oscillation in the channel. The non-resonant features were used to demonstrate the capabilities of such devices in terahertz imaging. We also cooled our device down to 4.2K to increase the quality factor and resonant detection was observed by using a tunable source of terahertz radiation.
We report on the clear evidence of massless Dirac fermions in two-dimensional system based on III-V semiconductors. Using a gated Hall bar made on a three-layer InAs/GaSb/InAs quantum well, we ...restore the Landau levels fan chart by magnetotransport and unequivocally demonstrate a gapless state in our sample. Measurements of cyclotron resonance at different electron concentrations directly indicate a linear band crossing at the \(\Gamma\) point of Brillouin zone. Analysis of experimental data within analytical Dirac-like Hamiltonian allows us not only determing velocity \(v_F=1.8\cdot10^5\) m/s of massless Dirac fermions but also demonstrating significant non-linear dispersion at high energies.
The digestibility of carbohydrates, protein and fat was studied in 8- to 12-week-old piglets fitted with a T-shaped cannula at the terminal ileum and fed two diets based on barley and wheat as the ...cereal source and with protein from soybean meal (diet CS) or pea, soybean meal and rapeseed cake (diet CPSR). The diets were fed either alone or supplemented with single enzymes (α-galactosidase, xylanase, β-glucanase, α-amylase, protease) or with a mixture of enzymes (α-galactosidase, xylanase and protease). After completing the digestibility trials, four piglets on each of the two basal diets were slaughtered and samples of digesta were taken along the gastrointestinal (GI) tract for additional measurements of carbohydrates and organic acids. Three hours after the meal the disappearance of raffinose oligosaccharides (raffinose, stachyose and verbascose) was about 39% as measured in the pooled digesta from the stomach and the small intestine. Digestibility of raffinose oligosaccharides at the terminal ileum was 86–90%. The relatively high digestibility in the upper intestine is most likely caused by endogenous plant and microbial α-galactosidases. The digestibility of starch at all sampling points along the GI tract was significantly higher with diet CS than with diet CPSR, while the digestibility of protein, fat and non-starch polysaccharides was similar for the two diets. In the large intestine, pectin was more rapidly and extensively digested than cellulose, arabinoxylans and xylan polysaccharides but the fermentation yielded similar proportions of acetate, propionate and butyrate. The supplementation of diet CS with xylanase or diet CPSR with the enzyme mixture, increased the digestibility of xylose of diet CS and xylose, arabinose and mannose and DM of diet CPSR. None of the other enzymes, however, improved the digestibility of nutrients.
Mean platelet volume (MPV) is a readily accessible and commonly tested hematological indicator. Recent studies revealed a significant impact of MPV on the course and prognosis of many diseases, ...including some types of cancer, as well as on the incidence of atrial fibrillation and bleeding. The study aimed to perform a retrospective analysis of MPV in terms of time to first treatment (TTFT) and to determine its prognostic value in the group of patients with chronic lymphocytic leukemia (CLL). Moreover, the study includes a retrospective analysis of platelet parameters in patients treated with ibrutinib concerning bleeding and atrial fibrillation.
The study included 523 patients with CLL, for 344 the most important cytogenetic aberrations were reported. The Mann-Whitney, Kruskal-Wallis, Kaplan-Meier, chi-squared, log‑rank tests and multivariate Cox proportional hazard regression model were used to analyze collected data.
The receiver operating characteristic curve analysis was performed to identify optimal cut-off value for MPV. The analysis of survival curves showed that in the group of patients with higher values of MPV TTFT was significantly longer than in the group with lower MPV (17.9 vs 36 months, p=0.0015, cut-off value for MPV= 10.4 fl). In multivariate Cox proportional hazard regression model low MPV, the presence of del11q and del13q provided independent prognostic value for TTFT (HR=0.69, 95%-CI, 0.5293 to 0.9081; p=0.0078; HR=1.76, 95%-CI, 1.3000 to 2.3882, p=0.0003, HR=0.74, 95%-Cl, 0.5674 to 0.9588, p=0.0229, respectively). In the group treated with ibrutinib, 59 patients had no significant correlation between MPV level and the incidence of therapy complications, although in the group of patients with low MPV there was a tendency for more frequent occurrence of atrial fibrillation (p=0.259).
Low MPV values are associated with unfavorable prognosis and might represent a novel, independent prognostic factor in CLL.
Data from 32 nucleus and multiplier herds in Germany was used to estimate variance components and breeding values for five maternal behaviour traits in sows. The estimation was performed univariately ...using an animal threshold model. About 31,000 farrowings recorded from December 2003 until July 2005 were included. The heritability coefficients were 0.07 (0.06) for group behaviour, 0.06 (0.03) for attitude to people, 0.05 (0.01) for maternal ability, 0.03 (0.01) for crushing of piglets and 0.02 (0.02) for savaging of piglets. Additionally, genetic correlations between the behaviour traits and between the behaviour traits and litter size, respectively, were estimated multivariately by REML with a linear model. Low heritability and weak genetic correlation to litter size at birth indicate that it may be difficult to genetically improve the maternal behaviour, and that selection for better mothering ability is not necessarily accompanied by reduced litter size at birth.
There is a paucity of data on the immune reconstitution inflammatory syndrome (IRIS) in the Central African region. We followed ART-naive HIV-infected patients initiating antiretroviral therapy in an ...HIV clinic in Gabon, for 6 months. Among 101 patients, IRIS was diagnosed in five. All IRIS cases were mucocutaneous manifestations. There were no cases of tuberculosis (TB) IRIS, but active TB (
n
= 20) was associated with developing other forms of IRIS (
p
= 0.02). Six patients died. The incidence of IRIS is low in Gabon, with mild, mucocutaneous manifestations.
Genetic parameters of piglet survival traits and birth weight were estimated on the first generation data of a selection experiment aimed at improving piglet survival using a multiple trait linear ...and threshold model. Data on 5293 piglets for survival at birth, at day one after birth and during the entire nursing period, as well as individual birth weight and litter size, were recorded in an outdoor production system. Genetic effects of piglet survival traits and birth weight were estimated based on threshold and Gaussian models, respectively, using a Bayesian approach. The statistical model included as fixed effects selection group, parity, gender, fostering, gestation length and month of farrowing and, alternatively, an adjustment for litter size. Direct genetic effects (i.e. the piglet's genetic potential) for piglet survival and birth weight were estimated separately, whereas maternal genetic and environmental effects could only be estimated for the given data structure in a combined litter effect. Posterior means of heritabilities for direct genetic effects of survival at birth, at first day after birth and the entire nursing period, as well as birth weight, were 0.08, 0.07, 0.08 and 0.20, respectively. Genetic correlations among survival traits were in the range of 0.29 to 0.40 and indicate that these traits were mainly attributable to different genetic effects. Genetic correlations between direct effects of survival traits and birth weight ranged between 0.18 and 0.23 and were reduced when weights of stillborn piglets were omitted in the analysis or the traits were adjusted for litter size. The magnitudes of direct genetic effects of survival traits are substantially higher than estimates in the literature, which may indicate that these traits have a higher genetic influence under outdoor conditions. The use of birth weight in the multiple trait estimation provided important information for the estimation of survival traits due to its favourable genetic correlations with survival, its high heritability and its high information content as a continuously measured trait.
Cathepsin B is a member of the papain superfamily of cysteine proteases and has been implicated in the pathology of numerous diseases, including arthritis and cancer. As part of an effort to identify ...potent, reversible inhibitors of this protease, we examined a series of dipeptidyl nitriles, starting with the previously reported Cbz−Phe−NH−CH2CN (19, IC50 = 62 μM). High-resolution X-ray crystallographic data and molecular modeling were used to optimize the P1, P2, and P3 substituents of this template. Cathepsin B is unique in its class in that it contains a carboxylate recognition site in the S2‘ pocket of the active site. Inhibitor potency and selectivity were enhanced by tethering a carboxylate functionality from the carbon α to the nitrile to interact with this region of the enzyme. This resulted in the identification of compound 10, a 7 nM inhibitor of cathepsin B, with excellent selectivity over other cysteine cathepsins.
We report on temperature-dependent magnetospectroscopy of two HgTe/CdHgTe quantum wells below and above the critical well thickness \(d_c\). Our results, obtained in magnetic fields up to 16 T and ...temperature range from 2 K to 150 K, clearly indicate a change of the band-gap energy with temperature. The quantum well wider than \(d_c\) evidences a temperature-driven transition from topological insulator to semiconductor phases. At the critical temperature of 90 K, the merging of inter- and intra-band transitions in weak magnetic fields clearly specifies the formation of gapless state, revealing the appearance of single-valley massless Dirac fermions with velocity of \(5.6\times10^5\) m\(\times\)s\(^{-1}\). For both quantum wells, the energies extracted from experimental data are in good agreement with calculations on the basis of the 8-band Kane Hamiltonian with temperature-dependent parameters.
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