julilili42/papers huggingface dataset:
Application of an optimized system for the well-defined exposure of human lung cells to trichloramine and indoor pool air
2011-05-11

In this study an in vitro exposure test to investigate toxicological effects of the volatile disinfection by-product trichloramine and of real indoor pool air was established. For this purpose a set-up to generate a well-defined, clean gas stream of trichloramine was combined with biotests. Human alveolar epithelial lung cells of the cell line A-549 were exposed in a CULTEX® device with trichloramine concentrations between 0.1 and 40 mg/m3 for 1 h. As toxicological endpoints the cell viability and the inflammatory response by the cytokines IL-6 and IL-8 were investigated. A decreasing cell viability could be observed with increasing trichloramine concentration. An increase of IL-8 release could be determined at trichloramine concentrations higher than 10 mg/m3 and an increase of IL-6 release at concentrations of 20 mg/m3. Investigations of indoor swimming pool air showed similar inflammatory effects to the lung cells although the air concentrations of trichloramine of 0.17 and 0.19 mg/m3 were much lower compared with the laboratory experiments with trichloramine as the only contaminant. Therefore it is assumed that a mixture of trichloramine and other disinfection by-products in the air of indoor pool settings contribute to that effect.
An ethics of body scanners: requirements and future challenges from an ethical point of view
2011-05-11

At the moment, body scanners based on terahertz and millimeter-wave technologies are implemented at airports around the world. Thus, challenges of acceptance and acceptability become pressing. In this context, we present the results of an ethical research project on the development and implementation of body scanners. We will show which requirements concerning the system, its developers, and its users should be met in order that the scanners can be acceptable from an ethical point of view. These requirements involve, among others, questions of privacy, health, data protection, and security processes. A special ethical challenge for body scanners, however, still remains: Automatic anonymization processes are based on the assumption of "normal" bodies. Certain groups of persons with "deviant bodies" (e.g. persons with hidden disabilities, persons with aberrant sex characteristics, etc.) are affected in a special way: Their deviation from the standard (for instance their disability) is socially hidden, but eventually exposed by body scanners, even (and even more) if the produced pictures are anonymized. Here, we address the question how the possible discrimination against and exclusion of people with "deviant bodies" could be mitigated or prevented.
NOA‐05 phase 2 trial of procarbazine and lomustine therapy in gliomatosis cerebri
2011-05-12

Abstract Objective: The NOA‐05 multicenter trial was performed to analyze the efficacy of primary chemotherapy with procarbazine and lomustine (PC) in patients with gliomatosis cerebri (GC) and to define clinical, imaging, and molecular factors influencing outcome. Methods: Thirty‐five patients with previously untreated GC were treated with up to six 56‐day courses of 110mg/m 2 lomustine on day 1 and 60mg/m 2 procarbazine on days 8 to 21. The primary endpoint was the rate of patients without therapy failure (defined as progressive disease, death from any cause, or termination of PC therapy before the end of course 4) at 8 months after the beginning of PC chemotherapy. Results: The failure‐free survival rate at 8 months was 50.3%. Median progression‐free survival was 14 months. At progression, 12 patients received salvage radiotherapy. Median overall survival was 30 months. Multivariate analysis revealed isocitrate dehydrogenase 1 ( IDH1 ) gene mutation (hazard ratio [HR], 0.11; 95% confidence interval [CI], 0.02–0.58) and initial presentation without a bilateral symmetrical infiltration pattern on magnetic resonance imaging (HR 0.07, 95%CI 0.01‐0.54) as independent prognostic factors associated with prolonged survival. IDH1 mutation was significantly associated with MGMT promoter methylation and an oligodendroglial tumor component. Interpretation: PC chemotherapy is effective in GC. With the NOA‐05 trial being the first prospective multicenter trial in GC, PC chemotherapy can be regarded as a promising option for the primary therapy of these tumors. Ann Neurol 2011;
Freeze-fracture replica immunolabelling reveals human WIPI-1 and WIPI-2 as membrane proteins of autophagosomes
2011-05-12

Autophagy defines the lifespan of eukaryotic organisms by ensuring cellular survival through regulated bulk clearance of proteins, organelles and membranes. Pathophysiological consequences of improper autophagy give rise to a variety of age-related human diseases such as cancer and neurodegeneration. Rational therapeutic implementation of autophagy modulation remains problematic, as fundamental molecular details such as the generation of autophagosomes, unique double-membrane vesicles formed to permit the process of autophagy, are insufficiently understood. Here, freeze-fracture replica immunolabelling reveals WD-repeat protein interacting with phosphoinositides 1 and 2 (WIPI-1 and WIPI-2) as membrane components of autophagosomes and the plasma membrane (PM). In addition, WIPI-1 is also present in membranes of the endoplasmic reticulum (ER) and WIPI-2 was further detected in membranes close to the Golgi cisternae. Our results identify WIPI-1 and WIPI-2 as novel protein components of autophagosomes, and of membrane sites from which autophagosomes might originate (ER, PM, Golgi area). Hence therapeutic modulation of autophagy could involve approaches that functionally target human WIPI proteins.
Increased Resting-State Perfusion after Repeated Encoding Is Related to Later Retrieval of Declarative Associative Memories
2011-05-12

Electrophysiological studies in animals have shown coordinated reactivation of neuronal ensembles during a restricted time period of behavioral inactivity that immediately followed active encoding. In the present study we directly investigated off-line processing of associative memory formation in the human brain. Subjects' regional cerebral blood flow (rCBF) as a surrogate marker of neural activity during rest was measured by MR-based perfusion imaging in a sample of 14 healthy male subjects prior to (Pre2) and after (Post) extensive learning of 24 face-name associations within a selective reminding task (SR). Results demonstrated significant Post-Pre2 rCBF increases in hippocampal and temporal lobe regions, while in a control comparison of two perfusion scans with no learning task in-between (Pre2-Pre1) no differences in rCBF emerged. Post perfusion scanning was followed by a surprise cued associative recall task from which two types of correctly retrieved names were obtained: older names already correctly retrieved at least once during one of the SR blocks, and recent names acquired during the last SR block immediately prior to the Post scan. In the anterior hippocampus individual perfusion increases were correlated with both correct retrievals of older and recent names. By contrast, older but not recently learned names showed a significant correlation with perfusion increases in the left lateral temporal cortex known to be associated with long-term memory. Recent, but not older names were correlated with dopaminergic midbrain structures reported to contribute to the persistence of memory traces for novel information. Although the direct investigation of off-line memory processing did not permit concomitant experimental control, neither intentional rehearsal, nor substantial variations in subjects' states of alertness appear to contribute to present results. We suggest that the observed rCBF increases might reflect processes that possibly contribute to the long-term persistence of memory traces.
Motivation losses in teamwork
2011-05-12

Team diversity may lead to a categorization of teammates as ingroup versus outgroup members. Therefore, the question arises whether there would be more permissiveness in reaction to ingroup free-riders than outgroup free-riders. To test this hypothesis, subjects were randomly assigned to one of two reward conditions (equity versus equality) and had to work with a partner who obviously underachieved and supposedly belonged to the same or a different group with regard to cognitive style. In addition, we assessed subjects’ individual sensitivity to equity norms, assuming that this would be a further moderator of the sucker effect. As expected, significant interaction effects on individual performance occurred for both variables.
Hydrothermal Oxidation Behavior of Bulk Titanium Aluminum Carbide
2011-05-12

Hydrothermal oxidation of bulk Ti 3 AlC 2 in continuous water flow was studied at 500°–700°C under a hydrostatic pressure of 35 MPa. During hydrothermal oxidation, titanium and aluminum were oxidized and selectively removed from Ti 3 AlC 2 with the survival of carbon. Reaction kinetics obeyed a linear time‐law. The hydrothermal oxidation rates were sluggish at 500– 600°C and faster at 700°C accompanied with the formation of cracks in oxides. This study clarified that the resistance of bulk Ti 3 AlC 2 against hydrothermal oxidation was high up to 700°C.
1,1,1‐Tris(distanna‐closo‐dodecaborate)stannate: A Tripodal Tin Ligand
2011-05-12

Tin tripod: Starting from 1,2-distanna-closo-dodecaborate and tin(II) chloride, the first tripodal tin ligand was prepared. It is made up of three clusters and one central tin atom that build a frame of seven tin atoms. The coordination ability is illustrated by reaction with [Cu(CH3CN)4]PF6: a binuclear copper complex is formed surrounded by two Sn7 ligands (see picture).
Urinary ammonia excretion increases acutely during living donor liver transplantation
2011-05-12

Abstract Introduction: Arterial ammonia concentrations increase acutely during the anhepatic phase of a liver transplantation (LTx) and return to baseline within 1 h after reperfusion of a functioning liver graft. So far, this return to baseline has solely been attributed to hepatic ammonia clearance. No data exist on the potential contribution of altered renal ammonia handling to peritransplantation ammonia homoeostasis. Aim: The present study investigated the consequences of a hepatectomy and subsequent implantation of a partial liver graft on arterial ammonia concentrations and urinary ammonia excretion during a living donor liver transplantation (LDLTx). Methods: Patients with end‐stage liver disease undergoing LDLTx were selected. Samples of arterial blood and urine were taken before, during and 2 h after the anhepatic phase. Differences were tested using Wilcoxon's test. Results are given as median and range. Results: Eleven adult patients undergoing an LDLTx were included. Before hepatectomy, arterial ammonia concentrations were 89 μM (40–156 μM), increasing to 146 μM (102–229 μM) ( P &lt;0.001) during the anhepatic phase and returning to 79 μM (46–111 μM) ( P &lt;0.01) after reperfusion. Urinary ammonia excretion was initially 1.06 mmol/h (0.02–6.00 mmol/h), increasing to 3.81 mmol/h (0.32–12.55 mmol/h) ( P =0.004) during the anhepatic phase and further increasing to 4.00 mmol/h (0.79–9.51 mmol/h) ( P =0.013) after reperfusion. Conclusion: The kidney significantly increased urinary ammonia excretion during the anhepatic phase, which was sustained after reperfusion, contributing to the rapid decrease of ammonia concentrations. Accordingly, the plasma ammonia concentrations measured directly after LTx cannot simply be used as a read‐out of initial liver graft function.
NCO-sP(EO-stat-PO) Coatings on Gold Sensors—a QCM Study of Hemocompatibility
2011-05-13

The reliability of implantable blood sensors is often hampered by unspecific adsorption of plasma proteins and blood cells. This not only leads to a loss of sensor signal over time, but can also result in undesired host vs. graft reactions. Within this study we evaluated the hemocompatibility of isocyanate conjugated star shaped polytheylene oxide—polypropylene oxide co-polymers NCO-sP(EO-stat-PO) when applied to gold surfaces as an auspicious coating material for gold sputtered blood contacting sensors. Quartz crystal microbalance (QCM) sensors were coated with ultrathin NCO-sP(EO-stat-PO) films and compared with uncoated gold sensors. Protein resistance was assessed by QCM measurements with fibrinogen solution and platelet poor plasma (PPP), followed by quantification of fibrinogen adsorption. Hemocompatibility was tested by incubation with human platelet rich plasma (PRP). Thrombin antithrombin-III complex (TAT), β-thromboglobulin (β-TG) and platelet factor 4 (PF4) were used as coagulation activation markers. Furthermore, scanning electron microscopy (SEM) was used to visualize platelet adhesion to the sensor surfaces. Compared to uncoated gold sensors, NCO-sP(EO-stat-PO) coated sensors revealed significant better resistance against protein adsorption, lower TAT generation and a lower amount of adherent platelets. Moreover, coating with ultrathin NCO-sP(EO-stat-PO) films creates a cell resistant hemocompatible surface on gold that increases the chance of prolonged sensor functionality and can easily be modified with specific receptor molecules.
Rapid Assessment of Longitudinal Relaxation Time in Materials and Tissues With Extremely Fast Signal Decay Using UTE Sequences and the Variable Flip Angle Method
2011-05-14

: To develop suitable strategies for quantification of longitudinal relaxation time (T1) by means of ultrashort echo time (UTE) sequences and the variable flip-angle approach in materials and tissues with extremely fast signal decay.: A recently published modified Ernst equation, which correctly accounts for in-pulse relaxation of transverse magnetization, was used to numerically determine optimal flip angles for reliable assessment of T1 in case of extremely short effective transverse relaxation time (T2*). Various ratios of repetition time (TR) to T1 and radiofrequency (RF) pulse duration (TRF) to T2* were evaluated. Theoretical considerations were applied to solid polymeric material (T2* = 0.295 milliseconds), and T1 quantification was performed using various optimized flip-angle approaches at different RF pulse durations (TRF = 0.1-0.4 milliseconds). Furthermore, in vivo measurement of T1 in cortical bone was exemplarily performed in 3 healthy volunteers to test the applicability of the proposed method in vivo. For in vitro and in vivo studies, MR imaging was performed on a 3 T whole-body MR system using a 3D UTE sequence with a rectangular excitation pulse and centric radial readout.: Optimal flip angles were shown to be strongly dependent on TR/T1 and TRF/T2* ratios. Exemplarily, longitudinal relaxation time of the investigated solid polymeric material was determined to T1 = 223.1 ± 3.1 milliseconds with RF pulse duration of TRF = 0.2 milliseconds, and 12 acquired flip angles ranging from 5 to 60 degrees. Using only 2 optimized flip angles (8 degrees, 44 degrees), T1 of the same material was determined to T1 = 223.8 ± 4.2 milliseconds in a markedly less acquisition time. In vivo evaluation of cortical bone was feasible and showed T1 values of 80.4 ± 25.1 milliseconds, exemplarily.: Using the modified Ernst equation, it seems possible to rapidly evaluate 3D distribution of longitudinal relaxation time in materials and tissues with extremely fast signal decay by means of UTE sequences and only 2 measurements with optimized flip angles.
Common Input Explains Higher-Order Correlations and Entropy in a Simple Model of Neural Population Activity
2011-05-17

Simultaneously recorded neurons exhibit correlations whose underlying causes are not known. Here, we use a population of threshold neurons receiving correlated inputs to model neural population recordings. We show analytically that small changes in second-order correlations can lead to large changes in higher-order redundancies, and that the resulting interactions have a strong impact on the entropy, sparsity, and statistical heat capacity of the population. Our findings for this simple model may explain some surprising effects recently observed in neural population recordings.
Light Microscopy with Doughnut Modes: A Concept to Detect, Characterize, and Manipulate Individual Nanoobjects
2011-05-17

Abstract Higher order laser modes, mainly called doughnut modes (DMs) have use in many different branches of research, such as, bio‐imaging, material science, single‐molecule microscopy, and spectroscopy. The main reason of their increasing importance is that recently, the techniques to generate well‐defined DMs have been refined or rediscovered. Although their potential is still not fully utilized, their specifically polarized field distribution gives rise to a wide field of applications. They are contributing to complete our fundamental knowledge of the optical properties of single emitting species, such as molecules, nanoparticles, or quantum dots, offering insight into the three‐dimensional dipole or particle orientation in space. The perfect zero intensity in the focus center qualifies some DMs for stimulated emission depletion (STED) microscopy. For the same reason, they have been suggested for trapping and tweezing applications.
The Cell Adhesion Molecule Neurofascin Stabilizes Axo-axonic GABAergic Terminals at the Axon Initial Segment
2011-05-17

Cell adhesion molecules regulate synapse formation and maintenance via transsynaptic contact stabilization involving both extracellular interactions and intracellular postsynaptic scaffold assembly. The cell adhesion molecule neurofascin is localized at the axon initial segment of granular cells in rat dentate gyrus, which is mainly targeted by chandelier cells. Lentiviral shRNA-mediated knockdown of neurofascin in adult rat brain indicates that neurofascin regulates the number and size of postsynaptic gephyrin scaffolds, the number of GABA(A) receptor clusters as well as presynaptic glutamate decarboxylase-positive terminals at the axon initial segment. By contrast, overexpression of neurofascin in hippocampal neurons increases gephyrin cluster size presumably via stimulation of fibroblast growth factor receptor 1 signaling pathways.
Fate of neuron-glia synapses during proliferation and differentiation of NG2 cells
2011-05-17

Progenitor cells expressing proteoglycan NG2 (also known as oligodendrocyte precursor cells or polydendrocytes) are widespread in the grey and white matter of the CNS; they comprise 8-9% of the total cell population in adult white matter, and 2-3% of total cells in adult grey matter. NG2 cells have a complex stellate morphology, with highly branched processes that may extend more than 100 μm around the cell body. NG2 cells express a complex set of voltage-gated channels, AMPA/kainate and/or γ-aminobutyric acid (GABA)(A) receptors, and receive glutamatergic and/or GABAergic synaptic input from neurons. In every region of the brain NG2 cells are found as proliferative cells, and the fraction of actively cycling NG2 cells is quite high in young as well as in adult animals. During development NG2 cells either differentiate into myelinating oligodendrocytes (and possibly also few astrocytes and neurons) or persist in the brain parenchyma as NG2 cells. This review highlights new findings related to the morphological and electrophysiological changes of NG2 cells, and the fate of synaptic input between neurons and NG2 cells during proliferation and differentiation of these cells in the neonatal and adult nervous system of rodents.
Why is it crucial to reintegrate pathology into cancer research?
2011-05-17

Abstract The integration of pathology with molecular biology is vital if we are to enhance the translational value of cancer research. Pathology represents a bridge between medicine and basic biology, it remains the gold standard for cancer diagnosis, and it plays an important role in discovery studies. In the past, pathology and cancer research were closely associated; however, the molecular biology revolution has shifted the focus of investigators toward the molecular alterations of tumors. The reductionist approach taken in molecular studies is producing great insight into the inner workings of neoplasia, but it can also minimize the importance of histopathology and of understanding the disease as a whole. In turn, pathologists can underestimate the role of molecular studies in developing new ancillary techniques for clinical diagnosis. A multidisciplinary approach that integrates pathology and molecular biology within a translational research system is needed. This process will require overcoming cultural barriers and can be achieved through education, a more effective incorporation of pathology into biological research, and conversely an integration of biological research into the pathology laboratory.
Point and period prevalences of eczema in rural and urban schoolchildren in Ghana, Gabon and Rwanda
2011-05-17

Abstract Background Eczema is a growing problem in Africa, particularly amongst children. Objectives To investigate the point‐prevalences of eczema by physical examination in schoolchildren living in rural and urban areas and with different socioeconomic backgrounds in Ghana, Gabon and Rwanda. In Ghana period‐prevalences were also estimated by questionnaire and compared with the point‐prevalences. Methods In total, 4839 schoolchildren in Ghana, Gabon and Rwanda were seen by at least one dermatologist. The point‐prevalences of eczema were estimated on the basis of physical examination. Period‐prevalences were measured in Ghana with questionnaire based‐interviews adapted from the International Study of Asthma and Allergies in Childhood (ISAAC). Results The point‐prevalences were 1.5% and 1.6% in the two Ghanaian studies; 4% in Gabon and 0.8% in Rwanda. The period‐prevalences were 2.6% and 4.4% in the two Ghanaian studies. The prevalences of eczema were not significantly different when comparing the urban and rural groups as well as the different socioeconomic levels. The sensitivity and positive predictive value to identify eczema cases based on the questionnaires compared to the diagnoses by physical examination were only 33% and 22% in the first Ghanaian study and 10% and 4% in the second Ghanaian study respectively. Conclusions The point‐prevalences of eczema in the three African countries studied were low compared with industrialized countries. Physical examination by a dermatologist is still the gold standard to identify eczema cases because the sensitivity and the positive predictive value to identify eczema cases with questionnaires were low in the two Ghanaian studies.
Sitagliptin and metformin combination therapy for the treatment of Type 2 diabetes
2011-05-17

Insulin secretion and insulin sensitivity are impaired in Type 2 diabetes. Metformin improves insulin sensitivity by inhibiting hepatic glucose release. It is the preferred drug for first-line treatment in Type 2 diabetes. Sitagliptin, the first marketed dipeptidyl peptidase-IV inhibitor, improves insulin and glucagon secretions of the pancreatic β- and α-cells, respectively, in a strictly glucose-dependent manner by raising endogenous active glucagon-like peptide-1 concentrations. The combination of metformin and sitagliptin thus offers a beneficial and complementary addition of important drug actions on insulin resistance and insulin secretion. Metformin and sitagliptin are also available as a fixed-dose combination. This article reviews the published clinical studies on both substances and their combination, and evaluates the potential benefit of the metformin plus sitagliptin combination.