julilili42/papers huggingface dataset:
Latest news on Arabidopsis brassinosteroid perception and signaling
2011-01-01

Brassinosteroids (BRs) are plant hormones regulating growth and development. In interaction with other hormones, they are involved in environmental cue responses. The present model of the BR response pathway in Arabidopsis includes the perception of the hormone by the plasma membrane (PM) receptor brassinosteroid insensitive 1 (BRI1) and its hetero-oligomerization with the co-receptor BRI1-associated receptor kinase 1 (BAK1), followed by the activation of a signaling-cascade finally resulting in the expression of BR-responsive genes. New findings have shed light on the receptor density in the PM and on the molecular mechanism of BR perception, which includes the hormone-induced formation of a platform in the BRI1 extracellular domain for interaction with BAK1. Furthermore, new knowledge on early, BRI1-initiated signaling events at the PM-cytoplasm interface has recently been gained. In addition, a fast BR response pathway that modifies the membrane potential and the expansion of the cell wall - both crucial processes preceding cell elongation growth - have been identified. In this review, these latest findings are summarized and discussed against the background of the present model of BRI1 signaling.
Upward Geometric Graph Embeddings into Point Sets
2011-01-01

We study the problem of characterizing the directed graphs with an upward straight-line embedding into every point set in general or in convex position. We solve two questions posed by Binucci et al. [Computational Geometry: Theory and Applications, 2010]. Namely, we prove that the classes of directed graphs with an upward straight-line embedding into every point set in convex position and with an upward straight-line embedding into every point set in general position do not coincide, and we prove that every directed caterpillar admits an upward straight-line embedding into every point set in convex position. Further, we provide new partial positive results on the problem of constructing upward straight-line embeddings of directed paths into point sets in general position.
New insights into the mineralogy and weathering of the Meridiani Planum meteorite, Mars
2011-01-01

Abstract– Meridiani Planum is the first officially recognized meteorite find on the surface of Mars. It was discovered at and named after the landing site of the Mars Exploration Rover Opportunity. Based on its composition, it was classified as a IAB complex iron meteorite. Mössbauer spectra obtained by Opportunity are dominated by kamacite (α‐Fe‐Ni) and exhibit a small contribution of ferric oxide. Several small features in the spectra have been neglected to date. To shed more light on these features, five iron meteorite specimens were investigated as analogs to Meridiani Planum with a laboratory Mössbauer setup. Measurements were performed on (1) their metallic bulk, (2) troilite (FeS) inclusions, (3) cohenite ((Fe,Ni,Co) 3 C) and schreibersite ((Fe,Ni) 3 P), and (4) corroded rims. In addition to these room‐temperature measurements, a specimen from the Mundrabilla IAB‐ungrouped meteorite was measured at Mars‐equivalent temperatures. Based on these measurements, the features in Meridiani Planum spectra can be explained with the presence of small amounts of schreibersite and/or cohenite and iron oxides. The iron oxides can be attributed to a previously reported coating on Meridiani Planum. Their presence indicates weathering through the interaction of the meteorite with small amounts of water.
The intestinal factor Tff3 and a miRNA network regulate murine caloric metabolism
2011-01-01

Genetic impairment of the genes coding for three mammalian trefoil peptides resulted in severe gastrointestinal malfunctions. The trefoil peptides also appear involved in caloric metabolism. Monitoring global miRNA expression of Tff3 deficient mice points to an interplay of Tff3 with a miRNA regulatory network. We identified 21 miRNAs that were deregulated when compared to the wild type strain. In silico evaluation indicated that the majority of the 21 miRNA were connected with the metabolic pathway "glycolysis/gluconeogenesis'' (p=0.032), a signaling pathway including nine target genes Aldh9a1, Aldh2, Pck1, Aldoc, Pgam2, Pck2, Adh4, Adh5, and Fbp1. Association of Tff3 with this metabolic pathway is further supported by the observation that the body mass of adult Tff3 KO mice (five months) showed a clearly reduced weight. Furthermore, the majority of the identified 21 miRNA genes are localized on murine chromosomes 2 and 5 in three clusters (2A1, 2B, 5B3) suggesting a coordinated expression control and function.
Functionalization of MCM-41 and SBA-1 with titanium(iv) (silyl)amides
2011-01-01

The surface organometallic chemistry (SOMC) of Ti(NMe2)4 and Ti(NMe2)3[N(SiHMe2)2] on periodic mesoporous silica (PMS) materials MCM-41 and SBA-1 was examined. While the smaller titanium amide gave the highest titanium loadings (e.g., Ti(NMe2)4@MCM-41: 12.1 wt%), a ligand-promoted silylation reaction competes effectively with Ti–N bond protonolysis for the tailor-made complex Ti(NMe2)3[N(SiHMe2)2]. Pre-functionalized materials SiMePh2@PMS and [Mg{N(SiHMe2)2}2]2@SBA-1 were employed for further control of the titanium load. Amido ligand exchange with R-(+)-1,1′-bi-2-naphthol (R-H2BINOL) was observed only on channel-like material Ti(NMe2)4@MCM-41, whereas size-selective grafting seems to be prominent on cage-like Ti(NMe2)4@SBA-1. All materials were characterized by DRIFT spectroscopy, nitrogen physisorption and elemental analysis.
Point-of-Care Tests for Bladder Cancer: The Influencing Role of Hematuria
2011-01-01

Introduction . Several point-of-care tests (POCT) are available for the diagnosis of bladder cancer (BC). We evaluate the impact of HU (hematuria) on performance of POCTs. Materials and Methods . Urine from 10 donors was diluted with blood from 0.5 to 0.00625%. BladderCheck R , BTAstat R , BCM R , and BTA R tests were applied. Tests were additionally conducted in 54 patients with HU. HU was stratified according to the amount of erythrocytes (RBC)/ μ L using two systems: (1) no HU; mild microscopic HU; severe microscopic HU; gross HU; (2) I &lt;25 RBCs; &lt;250 II; ≥250 III. Results were compared to HU status and histopathology. Results . Gross HU became evident between 2090 RBCs/ μ L and 1065/ μ L. Addition of blood led to default tests in all 4: BladderCheck R 0.25%; BCM 0.025%, BioNexia 0.00625%, and BTAstat &lt;0.00625%. Rates of false positives for BladderCheck, BTAstat, BCM, and BioNexia were 5.9, 11.8, 0, and 1.8% without HU and 0, 66.7, 44.4, and 66.7% with HU. BTAstat, BCM, and BioNexia were independently influenced by HU (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mrow><mml:mi>P</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>0.0002</mml:mn></mml:mrow></mml:math>). Conclusions . NMP22-BladderCheck was most resistant to blood. The diagnostic yield of all others was significantly influenced by HU. A well-defined HU grading helps to define limits of HU for a reliable interpretation of BC-POCTs.
Transduction in Semiconducting Metal Oxide Based Gas Sensors - Implications of the Conduction Mechanism
2011-01-01

Abstract For chemoresistive sensors based on semiconducting metal oxides the conduction mechanism in the sensing layer has a very large impact on the magnitude and even on the direction of the sensor signal. That means that for very similar surface reactivity (reception function) the translation of the surface charge transfer processes into sensor resistance changes (transduction function) can be very different. This idea is illustrated with the example of the different sensor signals for different conduction types, n and p and with the example of the change of sensor signal direction determined by the change of the conduction type under various ambient atmospheres.
Pex11pβ-mediated maturation of peroxisomes
2011-01-01

Peroxisomes are highly dynamic, multifunctional organelles that display remarkable changes in morphology, number and enzyme content. Peroxisomes multiply by growth and division of pre-existing organelles, but they can also form de novo from the ER. Growth and division of peroxisomes in mammalian cells involves elongation, membrane constriction and final fission and requires the peroxisome biogenesis Pex11 proteins as well as the recruitment of Dynamin-like protein DLP1/Drp1. We recently exploited the division-inhibiting properties of a unique Pex11pβ-YFP fusion protein to further dissect the process of peroxisomal growth and division. By applying life cell imaging and the HaloTag technology, our study revealed that Pex11pβ-mediated growth (elongation) and division of peroxisomes follows a multistep maturation pathway, which is initiated by the formation of an early peroxisomal membrane compartment from a pre-existing peroxisome and its stepwise conversion into a mature, metabolically active peroxisome compartment. Our observations support the view that peroxisomes formed by growth and division of pre-existing ones contain new membrane and matrix components. Peroxisome division is an asymmetric process, which is more complex than simple (symmetric) division of a preexisting organelle and equal distribution of the protein content. Our findings are in favor of Pex11pβ acting as a peroxisomal membrane shaping protein.
Direct observation of step-edge barrier effects and general aspects of growth processes: morphology and structure in diindenoperylene thin films deposited on Au(100) single crystals
2011-01-01

We investigate thin films of diindenoperylene deposited on Au(100) single crystals by using real time in situlow energy electron microscopy (LEEM) in synergy with X-ray photoelectron spectroscopy (XPS), and near edge X-ray absorption fine structure (NEXAFS) spectroscopy. We find evidence for Stranski–Krastanov growth, with island nucleation prevalently at step bunches, and a lower probability of island nucleation at terraces. We also directly observe the effect of the Ehrlich–Schwoebel barrier at the substrate and in the film morphology, in particular inside the islands that show a non-homogeneous thickness due to a rough front growth, because of the additional energy required for the diffusing molecules to surmount a downward step.
3D Chemical and Elemental Imaging by STXM Spectrotomography
2011-01-01

Spectrotomography based on the scanning transmission x‐ray microscope (STXM) at the 10ID‐1 spectromicroscopy beamline of the Canadian Light Source was used to study two selected unicellular microorganisms. Spatial distributions of sulphur globules, calcium, protein, and polysaccharide in sulphur‐metabolizing bacteria (Allochromatium vinosum) were determined at the S 2p, C 1s, and Ca 2p edges. 3D chemical mapping showed that the sulphur globules are located inside the bacteria with a strong spatial correlation with calcium ions (it is most probably calcium carbonate from the medium; however, with STXM the distribution and localization in the cell can be made visible, which is very interesting for a biologist) and polysaccharide‐rich polymers, suggesting an influence of the organic components on the formation of the sulphur and calcium deposits. A second study investigated copper accumulating in yeast cells (Saccharomyces cerevisiae) treated with copper sulphate. 3D elemental imaging at the Cu 2p edge showed that Cu(II) is reduced to Cu(I) on the yeast cell wall. A novel needle‐like wet cell sample holder for STXM spectrotomography studies of fully hydrated samples is discussed.
Wavelet analysis of skin blood flow in dermatosurgery using primary closure with tension
2011-01-01

Primary closure in dermatologic surgery is state of the art in small lesions at the head, but also in larger lesions at the trunk or the extremities. Microcirculatory effects on the skin blood flow near to the wound edges affected by primary closure. Forty three patients were investigated. Before and after surgery, skin blood flow was measured using Laser Doppler Fluxmetry (LDF). During primary closure, tension in the suture was measured and the tension on the wound edges was calculated. Times series were analyzed using continuous wavelet analyses, before, after 2 h and 24 h after surgery. After three months, the cosmetic results were requested. Median horizontal diameter was 22 mm (quartiles 20/48 mm), median vertical diameter was 44 mm (quartiles 26/60 mm). Mean string force was 12.0 SD 10.2 N. During the whole course of investigation, we found no change of microcirculatory parameters such as mean LDF or any scaling level following wavelet analysis caused by primary closure. Average of the cosmetic result was 1.8. It is a relative small number of patients and the defects are located in different areas. Skin blood flow and the microcirculatory pattern is not affected in the area by the tension on wound edges and provides therefore a fast healing process without any vegetatively induced complications even if the string force is high. In dermatosurgery, wounds can be closed directly without changing the microcirculatory pattern in the direct area of the wound margins.
Reduced-Intensity Conditioning in Allogeneic Stem Cell Transplantation for Hematological Malignancies: A Historical Perspective
2011-01-01

Allogeneic hematopoietic stem cell transplantation represents a curative treatment approach for a large range of hematologic malignancies. Traditionally, high-dose radiochemotherapy as preparative regimen has been thought to be necessary for successful allogeneic stem cell transplantation. However, high-dose conditioning often results in considerable medullary and extramedullary toxicity, contributing to high rates of treatment-related mortality. This limits the use of this procedure to patients below 60 years of age without significant comorbidities. Since the peak incidence of most hematological malignancies is beyond the 5th decade of life, the majority of patients are not eligible for high-dose treatment. During the last 15 years, several dose-reduced or even non-myeloablative conditioning regimens have been developed, offering a curative treatment option for these patients. This review summarizes the history of reduced-intensity conditioning (RIC) transplantations, depicts the differences among regimens, highlights significant patient factors, and describes the impact on selected hematological malignancies.
The ESF Meeting on „The Proteomics, Epigenetics and Pharmacogenetics of Pendrin“
2011-01-01

Human pendrin (SCL26A4, PDS) is a 780 amino acid integral membrane protein with transport function. It acts as an electroneutral, sodium-independent anion exchanger for a wide range of anions, such as iodide, chloride, formate, bicarbonate, hydroxide and thiocyanate. Pendrin expression was originally described in the thyroid gland, kidney and inner ear. Accordingly, pendrin mutations with reduction or loss of transport function result in thyroid and inner ear abnormalities, manifested as syndromic (Pendred syndrome) and non-syndromic hearing loss with an enlarged vestibular aqueduct (ns-EVA). Pendred syndrome, the most common form of syndromic deafness, is an autosomal recessive disease characterized by sensorineural deafness due to inner ear malformations and a partial iodide organification defect that may lead to thyroid goiter. Later, it became evident that not only pendrin loss of function, but also up-regulation could participate in the pathogenesis of human diseases. Indeed, despite the absence of kidney dysfunction in Pendred syndrome patients, evidence exists that pendrin also plays a crucial role in this organ, with a potential involvement in the pathogenesis of hypertension. In addition, recent data underscore the role of pendrin in exacerbations of respiratory distresses including bronchial asthma and chronic obstructive pulmonary disease (COPD). Pendrin expression in other organs such as mammary gland, testis, placenta, endometrium and liver point to new, underscored pendrin functions that deserve to be further investigated.
Selection criteria for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in gastric cancer
2011-01-01

Peritoneal carcinomatosis in gastric cancer is associated with a dismal prognosis. Systemic chemotherapy is not effective because of the existence of a blood-peritoneal barrier. Cytoreductive surgery and intraperitoneal chemotherapy can improve survival and quality of life in selected patients. Patient selection for this multimodal approach is one of the most critical issues, and calls for interdisciplinary evaluation by radiologists, medical and surgical oncologists, and anaesthetists. This article sets forth criteria for selection of gastric cancer patients suffering from peritoneal carcinomatosis.
Do We Have a “Mental Syllabary” in the Brain? An fMRI Study
2011-01-01

The present study combines functional magnetic resonance imaging (fMRI) and reaction time (RT) measurements to further elucidate the influence of syllable frequency and complexity on speech motor control processes, i.e., overt reading of pseudowords. Tying in with a recent fMRI-study of our group we focused on the concept of a mental syllabary housing syllable sized ready-made motor plans for high- (HF), but not low-frequency (LF) syllables. The RT-analysis disclosed a frequency effect weakened by a simultaneous complexity effect for HF-syllables. In contrast, the fMRI data revealed no effect of syllable frequency, but point to an impact of syllable structure: Compared with CV-items, syllables with a complex onset (CCV) yielded higher hemodynamic activation in motor “execution” areas (left sensorimotor cortex, right inferior cerebellum), which is at least partially compatible with our previous study. We discuss the role of the syllable in speech motor control.
Dynamic Production of Soluble Extracellular Polysaccharides byStreptococcus mutans
2011-01-01

Caries development in the presence of Streptococcus mutans is associated not only with the production of extracellular water-insoluble polymers but also is based on water-soluble polysaccharides. The aim of this study was the evaluation of a novel glucan-specific Lectin assay for monitoring water-soluble EPS produced by S. mutans during several growth periods in different media. S. mutans cultures were grown for 24 h, 48 h, and 144 h in medium deficient of sucrose (A) and medium supplemented with 5% sucrose (B). Microtiter well plates were coated with cell-free supernatants followed by the addition of labeled Concanavalin-A and enzyme substrate. The substrate reactions were kinetically detected at 405 nm. The validation of the assay was performed using carbohydrates dextran, xanthan, and sucrose as reference. This new Concanavalin-A-based assay showed the highest sensitivity for dextran and revealed that the glucan production of S. mutans reached its maximum at 144 h in medium B according to bacterial maturation.
Prediction of Birth Weight Discordance in Twin Pregnancies by Second- and Third- Trimester Ultrasound
2011-01-01

&lt;i&gt;Introduction:&lt;/i&gt; Our purpose was to examine whether the prenatal prediction of a critical birth weight discordance (BWD) in twin pregnancies can be improved by using either different formulae for prenatal fetal weight estimation or single biometric measurements or by assessing the intertwin discordance in the second trimester rather than shortly before birth. &lt;i&gt;Material and Methods:&lt;/i&gt; We conducted a retrospective study involving 196 twin pregnancies with an ultrasound examination between 18 and 25 weeks of gestation and one within 14 days prior to delivery. The accuracy was assessed by comparing the prenatal intertwin discordance (PID) with the BWD. PID was estimated by 5 common fetal weight estimation formulae and by single biometric measurements prior to delivery and in the second trimester. &lt;i&gt;Results:&lt;/i&gt; The fetal weight estimation accuracy was similar in mono- and dichorionic pregnancies and the smaller and the larger twin. PID was most accurate with the fetal weight estimation formulae prior to delivery. The second-trimester measurements resulted in an underestimation of the BWD. Detection and false-positive rates for a BWD ≧20% were about 65 and 15%. &lt;i&gt;Discussion:&lt;/i&gt; About two thirds of the twin pregnancies with a relevant BWD can be detected prior to delivery. An optimal detection rate requires fetal weight estimation close to delivery.
Rapamycin-Induced Impaired Wound Healing Is Associated with Compromised Tissue Lactate Accumulation and Extracellular Matrix Remodeling
2011-01-01

&lt;i&gt;Introduction:&lt;/i&gt; Extracellular matrix (ECM) remodeling involving matrix metalloproteinases (MMPs) and wound lactate accumulation are essential elements of tissue repair. The aim of this study was to investigate whether rapamycin-induced impaired healing is associated with compromised wound fluid lactate accumulation and altered ECM remodeling. &lt;i&gt;Methods:&lt;/i&gt; Polyvinyl alcohol sponges were subcutaneously implanted in male C57/BL6 mice. Animals were randomized to daily intraperitoneal treatment with either vehicle or 1.5 mg/kg rapamycin. After 7 or 14 days, sponges were harvested to collect wound fluid for subsequent analyses. Wounds were excised for assessment of tensile strength. &lt;i&gt;Results:&lt;/i&gt; After 7 days, wound hydroxyproline content was significantly decreased due to rapamycin therapy, whereas the observed difference in tensile strength marginally failed to show statistical significance. In addition, rapamycin reduced wound lactate accumulation and enhanced MMP-2 protein expression, and both MMP-2 and MMP-9 activity. At day 14, wound tensile strength and hydroxyproline content were significantly lower along with an increase in MMP-2 and MMP-9 activity in rapamycin-treated mice. Similarly, wound fluid lactate concentration and MMP-2 protein expression were found to be persistently decreased and increased, respectively. &lt;i&gt;Conclusions:&lt;/i&gt; Rapamycin affects tissue repair by interfering with fundamental mechanisms involved in healing, namely lactate accumulation and ECM remodeling.
Current Status and New Developments in Breast MRI
2011-01-01

SUMMARY: Breast magnetic resonance imaging (MRI) is the most sensitive imaging modality for the detection of breast cancer. Its specificity is equivalent to that of mammography. Nowadays, breast MRI is an absolutely essential breast imaging method. Technical innovations allow dynamic contrast-enhanced (DCE) MRI of both breasts with high image quality. Thereby, DCE breast MRI should always be performed with regard to current standards. New quantitative techniques such as diffusion-weighted MRI are promising. However, they still have potential pitfalls, in particular with regard to the diagnosis of non-mass lesions and small breast lesions. Ongoing technical innovations can possibly help to further optimize breast MRI.