Valley-Polarized Quantum Hall Phase in a Strain-Controlled Dirac System.

In multivalley systems, the valley pseudospin offers rich physics going from encoding of information by its polarization (valleytronics), to exploring novel phases of matter when its degeneracy is changed. Here, by strain engineering, we reveal fully valley-polarized quantum Hall phases in the Pb_{1-x}Sn_{x}Se Dirac system. Remarkably, when the valley energy splitting exceeds the fundamental band gap, we observe a "bipolar quantum Hall phase," heralded by the coexistence of hole and electron chiral edge states at distinct valleys in the same quantum well. This suggests that spatially overlaid counterpropagating chiral edge states emerging at different valleys do not interfere with each other.

Assessment of flax and hemp fibres in terms of their impact on the growth performance and health status of weaned piglets.

Weaning is a critical phase in intensive piglet production marked by the frequent occurrence of digestive disorders posing health and economic burden. To stave off such weaning-related problems, antibiotics and supplements containing high levels of ZnO are often used. In this study, we investigated whether natural fibres obtained from two plants known for their dietary fibre profile and antioxidant properties: flax (Linum usitatissimum L.) and hemp (Cannabis sativa L.), can serve as a health-promoting diet supplement. The study was conducted on a total of 191 Polish Large White piglets from 18 L, from their birth to 56 days of age. Piglets were divided by litters into six groups: W1.5, F1.5, H1.5, W2.0, F2.0, and H2.0. Groups W1.5, F1.5, and H1.5 received feed supplemented with 1.5% fibre from wood cellulose (W), flax (F), and hemp (H), respectively, while groups W2.0, F2.0, and H2.0 received feed with a higher 2.0% content of the same fibres. Flax and hemp fibres were characterised by a complex composition, antioxidant properties due to the presence of phenolic acids, and low risk of mycotoxin contamination. Flax fibre resulted in best weight gains and feed conversion ratio (P ≤ 0.05) of piglets, while hemp fibre had higher positive effect on antioxidant status (P ≤ 0.05) compared to the other two fibre additives. Neither flax nor hemp fibres had any adverse effect on the haematological and biochemical blood parameters. Piglets receiving a diet with 1.5% added fibre showed better growth performance, while diet supplementation with 2% fibre had a beneficial effect on the content of butyric acid in the small intestinal chyme (P ≤ 0.05). The results suggested that both flax and hemp fibres can be innovative feed additives for weaned piglets. However, further studies should be conducted in commercial farms, as the effects of dietary fibre could vary in more challenging environmental conditions.

Electronic properties of TaAs2topological semimetal investigated by transport and ARPES.

We have performed electron transport and angle-resolved photo-emission spectroscopy (ARPES) measurements on single crystals of transition metal dipnictide TaAs2cleaved along the (2¯01) surface which has the lowest cleavage energy. A Fourier transform of the Shubnikov-de Haas oscillations shows four different peaks whose angular dependence was studied with respect to the angle between magnetic field and the [2¯01] direction. The results indicate elliptical shape of the Fermi surface cross-sections. Additionally, a mobility spectrum analysis was carried out, which also reveals at least four types of carriers contributing to the conductance (two kinds of electrons and two kinds of holes). ARPES spectra were taken on freshly cleaved (2¯01) surface and it was found that bulk states pockets at constant energy surface are elliptical, which confirms the magnetotransport angle dependent studies. First-principles calculations support the interpretation of the experimental results. The theoretical calculations better reproduce the ARPES data if the theoretical Fermi level (FL) is increased, which is due to a small n-doping of the samples. This shifts the FL closer to the Dirac point, allowing investigating the physics of the Dirac and Weyl points, making this compound a platform for the investigation of the Dirac and Weyl points in three-dimensional materials.

Histiocytic necrotising lymphadenitis in mediastinum mimicking thymoma or lymphoma - case presentation and literature review of Kikuchi Fujimoto disease.

Kikuchi Fujimoto disease (KFD) as a rare self-limiting lymphadenopathy of short and benign course concerns most frequently the lymph nodes of the neck. The most common symptoms are painfulness of the diseased area, fever and night sweating. The etiology is not well understood, but in the role of pathogenesis viral, autoimmune and genetic factors are taken into account. In the presented case of 37-year-old female it was necessary to exclude diseases such as lymphoma or thymoma because of atypical mediastinal location of Kikuchi Fujimoto disease. After multidisciplinary consultation the lymph node was resected from the mediastinum with videothoracoscopic approach. The diagnosis was difficult for the pathologist because of the large percentage of necrosis of the lymph node but the image was typical for histiocytic necrotizing lymphadenitis. Two cases of patients with KFD limited to the mediastinum have been previously reported in the literature. This article presents the world's first reported case of this disease in the topographic location of the thymus. Furthermore, a review of current literature was made.

High resolution LT-STM imaging of PTCDA molecules assembled on an InSb(001) c(8 × 2) surface.

The self-assembling of 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) molecules deposited on an InSb(001) c(8 × 2) surface at sub-monolayer quantities has been investigated at low temperature (77 K) using scanning tunnelling microscopy. Sub-molecular resolution was obtained on PTCDA molecules. The results reveal that individual PTCDA molecules are arranged on the substrate in chains parallel to the [110] crystallographic direction, correlated with characteristic features of the low temperature InSb(001) c(8 × 2) surface electronic structure. A structural model for PTCDA molecules adsorbed on InSb is proposed.

How flat is an air-cleaved mica surface?

Muscovite mica is an important mineral that has become a standard substrate, due to its easy cleavage along the {001} planes, revealing a very flat surface that is compatible with many biological materials. Here we study mica surfaces by dynamic atomic force microscopy (AFM) operated in the non-contact mode (NC-AFM) under ultra-high vacuum (UHV) conditions. Surfaces produced by cleaving in UHV cannot be imaged with NC-AFM due to large surface charges; however, cleavage in air yields much less surface charge and allows for NC-AFM imaging. We present highly resolved NC-AFM images of air-cleaved mica surfaces revealing a rough morphology originating from a high density of nanometre-sized particles. Among these particles, we find regularly shaped structures indicating the growth of crystallites on the surface. The contamination layer cannot be removed by degassing in UHV; even prolonged heating at a temperature of 560 K under UHV conditions does not yield an atomically flat surface.

PTCDA molecules on a KBr/InSb system: a low temperature STM study.

We have used scanning tunnelling microscopy (STM) at 77 K to investigate 3,4,9,10-perylene-tetracarboxylic dianhydride (PTCDA) molecules adsorbed on an ultrathin (1-2 monolayer (ML)) film of KBr grown on a c(8 × 2)InSb(001) substrate. The molecules are stabilized both at the KBr steps and on the terraces. On the 1 ML film the PTCDA molecules appear predominantly as single entities, whereas on the 2 ML film formation of molecular clusters is preferred. Differences in the adsorption configurations indicate that the interaction between the molecules and the surface differs significantly for the cases of 1 and 2 ML films. We present images of the molecules obtained with sub-molecular resolution for both filled and empty state sampling modes. We argue that the highest occupied molecular orbital (the lowest unoccupied molecular orbital) is responsible for intramolecular contrast in filled (empty) state images of the molecules, even though they are deformed due to strong interaction with the substrate.

One or two drains after lobectomy? A comparison of both methods in the immediate postoperative period.

BACKGROUND: The conventional method of double chest tube drainage after lobectomy is well established. The aim of the study was to compare the efficacy of the two-drain versus the single-drain approach after this procedure. METHODS: The data of 183 consecutive patients who underwent lobectomy between January 2000 and May 2005 were analyzed: 93 had two drains and 90 had a single, midposition drain. All patients were operated on by one surgeon with the same surgical technique. RESULTS: Patients with one drain had a shorter hospital stay (7.6 days vs. 9.0 days; P = 0.001). There were no significant differences in the amount of drainage, the necessity of redrainage or broncho-aspiration, and postoperative mortality or complications. The period in which opioids (4.8 days vs. 5.6 days; P = 0.0001) and nonsteroidal anti-inflammatory drugs (6.8 days vs. 7.7 days; P = 0.002) were required was shorter in patients with one drain. The fourth postoperative day was more painful for patients with a double drain. The cost savings in the one-drain group were approximately 125 Euros per patient. CONCLUSION: A single-drain method is effective, reduces hospitalization times and the cost of treatment in patients who undergo lobectomy.

PTCDA molecules on an InSb(001) surface studied with atomic force microscopy.

PTCDA (3,4,9,10-perylene-tetracarboxylic-dianhydride) molecular structures assembled on an InSb(001) c(8 × 2) reconstructed surface have been studied using frequency modulated atomic force microscopy. The high-resolution imaging of the structures is possible through repulsive interactions, using the constant height scanning mode. During initial stages of growth the [110] diffusion channel dominates as indicated by formation of long PTCDA molecular chains parallel to the [110] crystallographic direction on the InSb surface. For a single monolayer coverage a wetting layer of PTCDA is formed. Finally it is shown that the PTCDA/InSb is a promising system for building molecular nanostructures by manipulation of single molecules with the AFM tip.

Surgical treatment of lung cancer in patients under 45 years of age.

AIM: The aim of the study was to evaluate the characteristics and prognosis of radical surgical treatment in young patients under the age of 45 with lung cancer. METHODS: We retrospectively analysed the data of 85 young patients and 211 older patients who underwent anatomical lung resections in Wroclaw Thoracic Surgery Centre. RESULTS: Less lobectomies were performed (p = 0.048), the incidence of carcinoid was significantly higher (p < 0.0001), stage I of lung cancer was observed less frequently (p = 0.023), the frequency of metastasis to subcarinal lymph nodes was higher (p = 0.007), a bronchial stump was microscopically infiltrated more frequently, the complete resection was noted rarer (p = 0.016) and 3-year survival rate of squamous cell carcinoma patients was worse in younger group (p = 0.017). The statistical significance was not observed between the frequency of recurrences and overall survival. CONCLUSIONS: Lung cancer in younger patients seems to be more advanced at the time of surgery. It is probable that the group of younger patients with squamous cell carcinoma will require additional treatment after surgery.

Atomic structure of InSb(001) and GaAs(001) surfaces imaged with noncontact atomic force microscopy.

Noncontact atomic force microscopy (NC-AFM) has been used to study the c(8x2) InSb(001) and the c(8x2) GaAs(001) surfaces prepared by sputter cleaning and annealing. Atomically resolved tip-surface interaction maps display different characteristic patterns depending on the tip front atom type. It is shown that representative AFM maps can be interpreted consistently with the most recent structural model of A(III)B(V)(001) surface, as corresponding to the A(III) sublattice, to the B(V) sublattice, or to the combination of both sublattices.

Human lung fructose-1,6-bisphosphatase is localized in pneumocytes II.

The localization of fructose-1,6-bisphosphatase (Fru-1,6-Pase EC 3.1.3.11) in human alveolar epithelium was determined immunohistochemically using a polyclonal antibody raised against the enzyme purified from human liver. The immunohistochemical analysis revealed that the Fru-1,6-Pase was localized in pneumocytes II and was absent in pneumocytes I. Hypothetically Fru-1,6-Pase participating in glucose-6-phosphate synthesis from noncarbohydrate precursors increases NADPH level which is used for surfactant synthesis and for glutathione redox cycle.

Surface topography dependent desorption of alkali halides

Electron-stimulated desorption of the (100)KBr surface has been investigated in vacuum with noncontact atomic force microscopy and mass spectroscopy. It has been found that both desorption components (K and Br) show oscillatory dependence on the electron dose with the oscillation amplitude decaying gradually. These results correspond with periodically varying, as a result of a layer-by-layer desorption, surface topography. It is proposed that the surface terrace edges act as traps for excited F centers diffusing in the crystal. The oscillating density of terrace edges varies surface recombination/reflection rates for the F centers and modulates the balance between surface and bulk deexcitation of the crystal.

[Medico-legal certification of fatal cases after drug: abuse in the light of modern toxicological analysis]. / Opiniowanie sadowo-lekarskie w narkomanii w swietle nowoczesnej analityki toksykologicznej.

Introduction of modern instrumental methods for toxicological analysis make possible a detection and identification of xenobiotics in different kind of multicomponents biological samples (plant sources of narcotics, body fluids and tissues of abusers) on a low concentration level. In this way a range of possibilities for the interpretation of toxicological results was enlarged. General medicolegal trends are strictly connected with modern analytics and they can be discussed on the basis of drug--users and fatal cases of intoxications with narcotics. Toxicological findings of these cases were worked out by means of modern analytical method--liquid chromatography with mass detection (LC/MS).

cDNA sequence and kinetic properties of human lung fructose(1, 6)bisphosphatase.

A cDNA encoding fructose(1,6)bisphosphatase was isolated from total human lung RNA. The cDNA contained an open reading frame encoding 337 amino acids. The determined nucleotide sequence of the lung cDNA was significantly different from muscle cDNA and slightly differed from human liver cDNA in a single mutation (Gly-336 for Ala-336) and a T for C substitution in position 648. The human lung fructose(1, 6)bisphosphatase [Fru(1,6)Pase] was isolated and its kinetic parameters were compared with liver and muscle isoenzymes. Values of kcat for the lung Fru(1,6)Pase were lower than for the liver and muscle enzyme. Like the liver isoenzyme, lung Fru(1,6)Pase is significantly less inhibited by AMP than the muscle enzyme. The values of I0.5 were 9.5, 9.8, and 0.3 microM for the liver, lung, and muscle enzyme, respectively. The lung enzyme was slightly more sensitive to fructose(2,6)bisphosphate [Fru(2,6)P2] inhibition than the liver enzyme. Ki was 75 microM for the lung and 96 microM for the liver enzyme. The synergistic effect of AMP and Fru(2,6)P2 on the lung and liver Fru(1,6)Pase was also observed. In the presence of AMP the corresponding values of Ki for Fru(2,6)P2 were 16 microM for the lung and 10 microM for the liver enzyme.

Bombardment Induced Electron-Capture Processes at Sodium Halide Surfaces.

Discrete features observed in the energy distribution of electrons emitted from ion-bombarded sodium halide surfaces can be attributed to a new type of collisional deexcitation mechanism. Such a mechanism involves sodium atoms in bombardment-excited autoionizing states that are the result of cascade collisions within the crystal lattice. This deexcitation process, in contrast to that for a metal, is not simply a consequence of the inner-shell lifetime of the initial collisionally excited sodium Na+* ion. Rather, the deexcitation consists of a sequence of lattice collisions during which the excited Na+* ion captures an electron to form the inner-shell-excited Na0* states responsible for the observed transitions. The formation of such autoionizing Na0* states is described within the framework of a new model in which excitation processes and localized collisional electron-transfer mechanisms are taken into account. These localized electron-transfer processes make possible new channels for electronic deexcitation, chemical dissociation, and defect production; they are critical for understanding inelastic ion-surface collisions in solids.