bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of repeated x‐ray exposure on the resolution of amorphous selenium based x‐ray imagers
Authors: Kabir M. Z. , Chowdhury L. , DeCrescenzo G. , Tousignant O. , Kasap S. O. , Rowlands J. A.
Published: March 2010

Purpose:

A numerical model and the experimental methods to study the x‐ray exposure dependent change in the modulation transfer function (MTF) of amorphous selenium (a‐Se) based active matrix flat panel imagers (AMFPIs) are described. The physical mechanisms responsible for the x‐ray exposure dependent change in MTF are also investigated.

Methods:

A numerical model for describing the x‐ray exposure dependent MTF of a‐Se based AMFPIs has been developed. The x‐ray sensitivity and MTF of an a‐Se AMFPI have been measured as a function of exposure. The instantaneous electric field and free and trapped carrier distributions in the photoconductor layer are obtained by numerically solving the Poisson's equation, continuity equations, and trapping rate equations using the backward Euler finite difference method. From the trapped carrier distributions, a method for calculating the MTF due to incomplete charge collection is proposed.

Results:

The model developed in this work and the experimental data show a reasonably good agreement. The model is able to simultaneously predict the dependence of the sensitivity and MTF on accumulated exposure at different applied fields and bias polarities, with the same charge transport parameters that are typical of the particular a‐Se photoconductive layer that is used in these AMFPIs. Under negative bias, the MTF actually improves with the accumulated x‐ray exposure while the sensitivity decreases. The MTF enhancement with exposure decreases with increasing applied field.

Conclusions:

The most prevalent processes that control the MTF under negative bias are the recombination of drifting holes with previously trapped electrons (electrons remain in deep traps due to their long release times compared with the time scale of the experiments) and the deep trapping of drifting holes and electrons.
Comparison of Elekta VMAT with helical tomotherapy and fixed field IMRT: Plan quality, delivery efficiency and accuracy
Authors: Rao Min , Yang Wensha , Chen Fan , Sheng Ke , Ye Jinsong , Mehta Vivek , Shepard David , Cao Daliang
Published: March 2010

Purpose:

Helical tomotherapy (HT) and volumetric modulated arc therapy (VMAT) are arc‐based approaches to IMRT delivery. The objective of this study is to compare VMAT to both HT and fixed field IMRT in terms of plan quality, delivery efficiency, and accuracy.

Methods:

Eighteen cases including six prostate, six head‐and‐neck, and six lung cases were selected for this study. IMRT plans were developed using direct machine parameter optimization in the treatment planning system. HT plans were developed using a Hi‐Art II planning station. VMAT plans were generated using both the SmartArc IMRT module and a home‐grown arc sequencing algorithm. VMAT and HT plans were delivered using Elekta's PreciseBeam VMAT® linac control system (Elekta AB, Stockholm, Sweden) and a TomoTherapy Hi‐Art II system (TomoTherapy Inc., Madison, WI), respectively. Treatment plan quality assurance (QA) for VMAT was performed using the IBA MatriXX™ system while an ion chamber and films were used for HT plan QA.

Results:

The results demonstrate that both VMAT and HT are capable of providing more uniform target doses and improved normal tissue sparing as compared with fixed field IMRT. In terms of delivery efficiency, VMAT plan deliveries on average took 2.2 min for prostate and lung cases and 4.6 min for head‐and‐neck cases. These values increased to 4.7 and 7.0 min for HT plans.

Conclusions:

Both VMAT and HT plans can be delivered accurately based on their own QA standards. Overall, VMAT was able to provide approximately a 40% reduction in treatment time while maintaining comparable plan quality to that of HT.
Application of the continuity equation to a breathing motion model
Authors: Low Daniel A. , Zhao Tianyu , White Benjamin , Yang Deshan , Mutic Sasa , Noel Camille E. , Bradley Jeffrey D. , Parikh Parag J. , Lu Wei
Published: March 2010

Purpose:

To quantitatively test a breathing motion model using the continuity equation and clinical data.

Methods:

The continuity equation was applied to a lung tissue and lung tumor free breathing motion model to quantitatively test the model performance. The model used tidal volume and airflow as the independent variables and the ratio of motion to tidal volume and motion to airflow were defined asandvector fields, respectively. The continuity equation resulted in a prediction that the volume integral of the divergence of thevector field was 1.11 for all patients. The integral of the divergence of thevector field was expected to be zero.

Results:

For 35 patients, thevector field prediction was, encompassing the expected value. For thevector field prediction, the average value was.

Conclusions:

These results provide quantitative evidence that the breathing motion model yields accurate predictions of breathing dynamics.
Blood Gene Expression Signatures Predict Invasive Candidiasis
Authors: Zaas Aimee K. , Aziz Hamza , Lucas Joseph , Perfect John R. , Ginsburg Geoffrey S.
Published: March 2010

Development and validation of a blood gene expression signature to diagnose
C. albicans
bloodstream infection.
Fighting Back: Peptidomimetics as a New Weapon in the Battle Against Antibiotic Resistance
Authors: Bragonzi Alessandra
Published: March 2010

An academic institution and a small company team up to develop a new
peptidomimetic antibiotic that kills
Pseudomona
s sp. by
targeting its outer-membrane synthesis.
Retinal Stem Cells: Eye Know Where to Go
Authors: Lavine Marc
Published: March 2010

Floating in a damage-repairing carrier, retinal stem cells that were transplanted into mice eyes integrated properly and adopted the native morphology.
Quality Monitoring of HIV-1-Infected and Uninfected Peripheral Blood Mononuclear Cell Samples in a Resource-Limited Setting
Authors: Olemukan Robert E. , Eller Leigh Anne , Ouma Benson J. , Etonu Ben , Erima Simon , Naluyima Prossy , Kyabaggu Denis , Cox Josephine H. , Sandberg Johan K. , Wabwire-Mangen Fred , Michael Nelson L. , Robb Merlin L. , de Souza Mark S. , Eller Michael A.
Published: March 2010

Human immunodeficiency virus type 1 (HIV-1) vaccine and natural history studies are critically dependent on the ability to isolate, cryopreserve, and thaw peripheral blood mononuclear cell (PBMC) samples with a high level of quality and reproducibility. Here we characterize the yield, viability, phenotype, and function of PBMC from HIV-1-infected and uninfected Ugandans and describe measures to ascertain reproducibility and sample quality at the sites that perform cryopreservation. We have developed a comprehensive internal quality control program to monitor processing, including components of method validation. Quality indicators for real-time performance assessment included the time from venipuncture to cryopreservation, time for PBMC processing, yield of PBMC from whole blood, and viability of the PBMC before cryopreservation. Immune phenotype analysis indicated lowered B-cell frequencies following processing and cryopreservation for both HIV-1-infected and uninfected subjects (P< 0.007), but all other major lymphocyte subsets were unchanged. Long-term cryopreservation did not impact function, as unstimulated specimens exhibited low background and all specimens responded to staphylococcal enterotoxin B (SEB) by gamma interferon and interleukin-2 production, as measured by intracellular cytokine staining. Samples stored for more than 3 years did not decay with regard to yield or viability, regardless of HIV-1 infection status. These results demonstrate that it is possible to achieve the high level of quality necessary for vaccine trials and natural history studies in a resource-limited setting and provide strategies for laboratories to monitor PBMC processing performance.
NEW ALL-PASS FILTER CIRCUIT COMPENSATING FOR C-CDBA NON-IDEALITIES
Authors: METIN BILGIN , PAL KIRAT
Published: March 2010

In this paper, a CMOS current controlled current differencing buffered amplifier (C-CDBA) realization is presented. Also, a new first-order all-pass filter that compensates for some C-CDBA non-idealities is given as an application example. The all-pass filter circuit has low output impedance for easy cascadability and it can be made electronically tunable using the proposed C-CDBA implementation. The theoretical results are verified with SPICE simulations.
GENERAL SPICE MODELS FOR MEMRISTOR AND APPLICATION TO CIRCUIT SIMULATION OF MEMRISTOR-BASED SYNAPSES AND MEMORY CELLS
Authors: SHARIFI MOHAMMAD JAVAD , BANADAKI YASSER MOHAMMADI
Published: March 2010

Memristor had been first theorized nearly 40 years ago by Prof. Chua, as the fourth fundamental circuit element beside the three existing elements (Resistor, Capacitor and Inductor) but because no one has succeeded in building a memristor, it has long remained a theoretical element. Some months ago, Hewlett-Packard (hp) announced it created a memristor using a TiO2/TiO2-X structure. In this paper, the characteristics, structures and relations for the invented hp's memristor are briefly reviewed and then two general SPICE models for the charge-controlled and flux-controlled memristors are introduced for the first time. By adjusting the model parameters to the hp's memristor characteristics some circuit properties of the device are studied and then two important memristor applications as the memory cell in a nonvolatile-RAM structure and as the synapse in an artificial neural network are studied. By utilizing the introduced models and designing the appropriate circuits for two most important applications; a nonvolatile memory structure and a programmable logic gate, circuit simulations are done and the results are presented.
A SINGLE FORMULA AND ITS IMPLEMENTATION IN FPGA FOR ELLIPTIC CURVE POINT ADDITION USING AFFINE REPRESENTATION
Authors: MORALES-SANDOVAL M. , FEREGRINO-URIBE C. , CUMPLIDO R. , ALGREDO-BADILLO I.
Published: March 2010

A formula for point addition in elliptic curves using affine representation and its implementation in FPGA is presented. The use of this new formula in hardware implementations of scalar multiplications for elliptic curve cryptography has the main advantages of: (i) reducing area for the implementations of elliptic curve point addition, and (ii) increasing the resistance to side channel attacks of the hardware implementation itself. Hardware implementation of scalar multiplication for elliptic curve cryptography using this new formulation requires low area resources while keeping high performance compared to implementations using projective coordinates, which are usually considered faster than the affine coordinates.
A GENETIC ALGORITHM METHODOLOGY TO FIND THE MAXIMUM DATAPATH COVERAGE FOR COMBINATIONAL LOGIC CIRCUITS
Authors: SOSA JAVIER , MONTIEL-NELSON JUAN A. , NOOSHABADI SAEID
Published: March 2010

In this paper, we present a genetic algorithm (GA) based methodology for vector generation that maximizes the metric of datapath coverage for a given combinational logic circuit, and compare it with a standard greedy algorithm. The search of maximum coverage vectors is a complex optimization of a satisfiability problem. The GA deals with the optimization problem, whilst an external satisfiability solver is invoked to deal with the coverage problem. Experimental results and performance comparisons based on the large set of MCNC'91 suite of benchmark circuits are presented. They show significant speedups of the GA methodology against a greedy algorithm for large circuits.
AN ANALYTICAL CONGESTION MODEL WITH BOUNDED-BEND DETOURS
Authors: HE FEI , CHENG LERONG , SONG XIAOYU , YANG GUOWU
Published: March 2010

With the increase of the complexity of circuits, fast estimation can provide some vital information for optimal layout decisions. Fast congestion prediction plays an important role in the physical layout of VLSI design. In this paper, we present a probabilistic estimation approach with via minimization constraints. Our model is more realistic than previous models. It has more flexibility for wires to have more usage area to bypass congested regions and blockages. The experiment on routing benchmarks demonstrates the effectiveness of our approach.
NOVEL SELF-REFERENCE BASED IMAGE WATERMARKING SCHEME
Authors: FU YONG-GANG , SHEN RUIMIN
Published: March 2010

In this paper, a novel image watermarking scheme based on a self-reference technique is proposed. The meaningful watermark is embedded into a gray-level image according to the relation between the constructed reference image and the original host. In order to be robust against Jpeg compression, the reference image should be robust under Jpeg compression. Firstly, the original image is transformed into DCT domain; and then most of the high frequency coefficients are omitted; after the quantization step and inverse DCT transform, we can obtain a robust reference. By considering the relation between the original image and its reference, we can embed the watermark into the host. The watermark extraction process is oblivious. Experimental results under several attacks show good robustness of the proposed scheme. Especially under cropping and Jpeg compression attacks, the watermark can be extracted with only few errors.
FINDING POPULAR PLACES
Authors: BENKERT MARC , DJORDJEVIC BOJAN , GUDMUNDSSON JOACHIM , WOLLE THOMAS
Published: March 2010

Widespread availability of location aware devices (such as GPS receivers) promotes capture of detailed movement trajectories of people, animals, vehicles and other moving objects. We investigate spatio-temporal movement patterns in large tracking data sets, i.e. in large sets of polygonal paths. Specifically, we study so-called 'popular places', that is, regions that are visited by many entities.

Given a set of polygonal paths with a total of [Formula: see text] vertices, we look at the problem of computing such popular places in two different settings. For the discrete model, where only the vertices of the polygonal paths are considered, we propose an [Formula: see text] algorithm; and for the continuous model, where also the straight line segments between the vertices of a polygonal path are considered, we develop an [Formula: see text] algorithm. We also present lower bounds and hardness results.
On Reduced Time Evolution for Initially Correlated Pure States
Authors: Aniello P. , Kossakowski A. , Marmo G. , Ventriglia F. , Vitale P.
Published: March 2010

A new method to deal with reduced dynamics of open systems by means of the Schrödinger equation is presented. It allows one to consider the reduced time evolution for correlated and uncorrelated initial conditions.
Composite Fermions in Braid Group Terms
Authors: Jacak J. , Jóźwiak I. , Jacak L.
Published: March 2010

A new implementation of composite fermions, and more generally — of composite anyons is formulated, exploiting one-dimensional unitary representations of appropriately constructed subgroups of the full braid group, in accordance with a cyclotron motion of 2D charged particle systems. The nature of hypothetical fluxes attached to the Jain's composite fermions is explained via additional cyclotron trajectory loops consistently with braid subgroup structure. It is demonstrated that composite fermions and composite anyons are rightful 2D particles (not an auxiliary construction) associated with cyclotron braid subgroups instead of the full braid group, which may open a new opportunity for non-Abelian composite anyons for quantum information processing applications.
Water deprivation-induced sodium appetite and differential expression of encephalic c-Fos immunoreactivity in the spontaneously hypertensive rat
Authors: Pereira-Derderian Daniela T. B. , Vendramini Regina C. , Menani José V. , De Luca Laurival A.
Published: March 2010

The spontaneously hypertensive rat (SHR) has an intense consumption of NaCl solution. Water deprivation (WD) followed by water intake to satiety induces partial rehydration (PR)—the WD-PR protocol—and sodium appetite. In the present work, WD produced similar water intake and no alterations in arterial pressure among spontaneously hypertensive rat (SHR), Wistar-Kyoto, and Holtzman strains. It also increased the number of cells with positive c-Fos immunoreactivity (Fos-IR) in the lamina terminalis and in the hypothalamic supraoptic (SON) and paraventricular (parvocellular, PVNp) nucleus in these strains. The WD and WD-PR produced similar alterations in all strains in serum osmolality and protein, plasma renin activity, and sodium balance. The SHR ingested about 10 times more 0.3 M NaCl than normotensives strains in the sodium appetite test that follows WD-PR. After WD-PR, the Fos-IR persisted, elevated in the lamina terminalis of all strains but notably in the subfornical organ of the SHR. The WD-PR reversed Fos-IR in the SON of all strains and in the PVNp of SHR. It induced Fos-IR in the area postrema and in the nucleus of the solitary tract (NTS), dorsal raphe, parabrachial (PBN), pre-locus coeruleus (pre-LC), suprachiasmatic, and central amygdalar nucleus of all strains. This effect was bigger in the caudal-NTS, pre-LC, and medial-PBN of SHRs. The results indicate that WD-PR increases cell activity in the forebrain and hindbrain areas that control sodium appetite in the rat. They also suggest that increased cell activity in facilitatory brain areas precedes the intense 0.3 M NaCl intake of the SHR in the sodium appetite test.
Acute kidney injury: a springboard for progression in chronic kidney disease
Authors: Venkatachalam Manjeri A. , Griffin Karen A. , Lan Rongpei , Geng Hui , Saikumar Pothana , Bidani Anil K.
Published: March 2010

Recently published epidemiological and outcome analysis studies have brought to our attention the important role played by acute kidney injury (AKI) in the progression of chronic kidney disease (CKD) to end-stage renal disease (ESRD). AKI accelerates progression in patients with CKD; conversely, CKD predisposes patients to AKI. This research gives credence to older, well-thought-out wisdom that recovery from AKI is often not complete and is marked by residual structural damage. It also mirrors older experimental observations showing that unilateral nephrectomy, a surrogate for loss of nephrons by disease, compromises structural recovery and worsens tubulointerstitial fibrosis after ischemic AKI. Moreover, review of a substantial body of work on the relationships among reduced renal mass, hypertension, and pathology associated with these conditions suggests that impaired myogenic autoregulation of blood flow in the setting of hypertension, the arteriolosclerosis that results, and associated recurrent ischemic AKI in microscopic foci play important roles in the development of progressively increasing tubulointerstitial fibrosis. How nutrition, an additional factor that profoundly affects renal disease progression, influences these events needs reevaluation in light of information on the effects of calories vs. protein and animal vs. vegetable protein on injury and progression. Considerations based on published and emerging data suggest that a pathology that develops in regenerating tubules after AKI characterized by failure of differentiation and persistently high signaling activity is the proximate cause that drives downstream events in the interstitium: inflammation, capillary rarefaction, and fibroblast proliferation. In light of this information, we advance a comprehensive hypothesis regarding the pathophysiology of AKI as it relates to the progression of kidney disease. We discuss the implications of this pathophysiology for developing efficient therapeutic strategies to delay progression and avert ESRD.
Human Medial Orbitofrontal Cortex Is Recruited During Experience of Imagined and Real Rewards
Authors: Bray Signe , Shimojo Shinsuke , O'Doherty John P.
Published: March 2010

Human decision-making frequently relies on mental simulation of future rewards to guide action choice. In this study, we sought to uncover brain regions engaged during reward imagery and to address whether these regions functionally overlap with regions activated by tangible rewards. We found that medial orbitofrontal cortex (mOFC) is engaged both for real and imagined rewards and is preferentially engaged for imagery with rewarding content compared with other nonrewarding imagery. These findings support a critical role for mOFC in the representation of rewarding goal states, even if hypothetical.
Intermittent and sustained hypoxia induce a similar gene expression profile in human aortic endothelial cells
Authors: Polotsky Vsevolod Y. , Savransky Vladimir , Bevans-Fonti Shannon , Reinke Christian , Li Jianguo , Grigoryev Dmitry N. , Shimoda Larissa A.
Published: March 2010

Obstructive sleep apnea may cause vascular inflammation and atherosclerosis, which has been attributed to intermittent hypoxia (IH). Recent data suggest that IH, but not sustained hypoxia (SH), activates proinflammatory genes in HeLa cells. Effects of IH and SH on the gene expression profile in human aortic endothelial cells (HAEC) have not been compared. We perfused media with alternating flow of 16% and 0% O2 (IH) or constant flow of 4% O2 (SH-4%), 8% O2 (SH-8%), or 16% O2 (control) for 8 h. Illumina gene microarrays were performed, with subsequent verification by real-time PCR. Proinflammatory cytokines in the media were measured by ELISA. Both IH and SH-4% upregulated proinflammatory genes, including heat shock protein 90-kDa B1, tumor necrosis factor superfamily member 4, and thrombospondin 1. Among all proinflammatory genes, only IL-8 mRNA showed significantly higher levels of expression (1.78-fold) during IH, compared with SH-4%, but both types of hypoxic exposure elicited striking three- to eightfold increases in IL-8 and IL-6 protein levels in the media. IH and SH-4% also upregulated antioxidant genes, including heme oxygenase-1 and nuclear factor (erythroid-derived 2)-like 2 (NRF2), whereas classical genes regulated by hypoxia-inducible factor 1 (HIF-1), such as endothelin and glucose transporter GLUT1, were not induced. SH-8% induced changes in gene expression and cytokine secretion that were similar to those of IH and SH-4%. In conclusion, short exposures to IH and SH upregulate proinflammatory and antioxidant genes in HAEC and increase secretion of proinflammatory cytokines IL-8 and IL-6 into media in similar fashions.
X-ray powder diffraction investigation of green earth pigments
Authors: Rafalska-Lasocha Alicja , Kaszowska Zofia , Lasocha Wieslaw , Dziembaj Roman
Published: March 2010

Laboratory X-ray powder diffraction was used to investigate mineralogical compositions of green pigments labeled by suppliers as “green earths.” It was found that glauconite and celadonite—minerals historically considered as the main ingredient of this pigment—were present only in Bohemian green earth, green earth from Thuringen (glauconite), and Bavarian green earth (celadonite). Other investigated pigments consist of mineralogical-component minerals with added synthetic organic colorants. The obtained results may be useful for scientists, restorers, and artists in proper choices of the pigments they use in their works.
Crystal structure of antimony oxalate hydroxide, Sb(C2O4)OH
Authors: Kaduk James A. , Toft Mark A. , Golab Joseph T.
Published: March 2010

The crystal structure of Sb(C2O4)OH has been solved by charge flipping in combination with difference Fourier techniques using laboratory X-ray powder data exhibiting significant preferred orientation and refined by the Rietveld method. The compound crystallizes inPnmawitha=5.827 13(3),b=11.294 48 (10),c=6.313 77(3) Å,V=415.537(5) Å3, andZ=4. The crystal structure contains pentagonal pyramidal Sb3+cations, which are bridged by hydroxyl groups to form zigzag chains along theaaxis. Each oxalate anion chelates to two Sb in approximately theabplane, linking the chains into a three-dimensional framework. The H of the hydroxyl group is probably disordered in order to form stronger more-linear hydrogen bonds. The highest energy occupied molecular orbitals are the Sb3+lone pairs. The structure is chemically reasonable compared to other antimony oxalates and to Bi(C2O4)OH.
Dynamical Aspects of an Equilateral Restricted Four‐Body Problem
Authors: Álvarez-Ramírez Martha , Vidal Claudio
Published: March 2010

The spatial equilateral restricted four‐body problem (ERFBP) is a four
body problem where a mass point of negligible mass is moving under the
Newtonian gravitational attraction of three positive masses (called the primaries) which move on circular periodic orbits around their center of mass
fixed at the origin of the coordinate system such that their configuration is
always an equilateral triangle. Since fourth mass is small, it does not affect
the motion of the three primaries. In our model we assume
that the two masses of the primaries m2 and m3 are equal to μ and the mass m1 is 1 − 2μ. The Hamiltonian function that governs the motion of the fourth mass is derived and it has three degrees of freedom depending periodically on time. Using a synodical system, we fixed the primaries in order to eliminate the time dependence. Similarly to the circular restricted three‐body problem, we obtain a first integral of motion. With the help of the Hamiltonian structure, we characterize the region of the possible motions and the surface of fixed level in the spatial as well as in the planar case. Among other things, we verify that the number of equilibrium solutions depends upon the masses, also we show the existence of periodic solutions by different methods in the planar case.
Acoustic Source Localization via Time Difference of Arrival Estimation for Distributed Sensor Networks Using Tera‐Scale Optical Core Devices
Authors: Imam Neena , Barhen Jacob
Published: March 2010

For real‐time acoustic source localization applications, one of the primary challenges is the considerable growth in computational complexity associated with the emergence of ever larger, active or passive, distributed sensor networks. These sensors rely heavily on battery‐operated system components to achieve highly functional automation in signal and information processing. In order to keep communication requirements minimal, it is desirable to perform as much processing on the receiver platforms as possible. However, the complexity of the calculations needed to achieve accurate source localization increases dramatically with the size of sensor arrays, resulting in substantial growth of computational requirements that cannot be readily met with standard hardware. One option to meet this challenge builds upon the emergence of digital optical‐core devices. The objective of this work was to explore the implementation of key building block algorithms used in underwater source localization on the optical‐core digital processing platform recently introduced by Lenslet Inc. This demonstration of considerably faster signal processing capability should be of substantial significance to the design and innovation of future generations of distributed sensor networks.
Research on Influences of Transient High IOP during LASIK on Retinal Functions and Ultrastructure
Authors: Zhao Haixia , Ai Yude , Niu Chunmei , Guan Wenying , Li Xiaoling , Qin Liru
Published: March 2010

Objectives. To study the influences of transient high intraocular pressure(IOP) during LASIK on retinal functions and ultrastructure.Methods. Thirty-two New Zealand white rabbits were randomly divided into normal control, experimental control, negative suction 20 s and negative suction 3 min groups. The experimental control group was treated only by laser. Rabbit eyes received suction for different periods of time (20 s, 3 min) by negative pressure generator in different groups. The changes of neuro-optic and retinal ultrastructure were observed under electron and light microscopes; retinal neurofunctional changes were observed with flash-visual evoked potential (F-VEP) and flash-electroreinogram (F-ERG).Results. There was no obvious change in optic nerve, retina, ERG a-wave and b-wave in normal control and experimental control groups. There were slight changes in tissues of optic nerve and retina at various times of suction 20 s compared with control group, and a sharp change in suction 3 min group within 14d after operation, but these changes recovered at 28d. Amplitude of ERG b-wave observed at different time will decrease with suction periods prolonged. It can recover to normal level with the prolonged recovery periods. Amplitude and incubation period of ERG a-wave and VEP-P did not change significantly after different duration of suction.Conclusions. The transient high IOP during LASIK might have influence on retinal function and ultrastructure, but these changes were reversible.
Plasticity of Horizontal Connections at a Functional Border in Adult Rat Somatosensory Cortex
Authors: Marik Sally A. , Hickmott Peter W.
Published: March 2010

Horizontal connections in superficial cortical layers integrate information across sensory maps by connecting related functional columns. It has been hypothesized that these connections mediate cortical reorganization via synaptic plasticity. However, it is not known if the horizontal connections from discontinuous cortical regions can undergo plasticity in the adult. Here we located the border between two discontinuous cortical representations in vivo and used either pairing or low-frequency stimulation to induce synaptic plasticity in the horizontal connections surrounding this border in vitro. Individual neurons revealed significant and diverse forms of synaptic plasticity for horizontal connections within a continuous representation and discontinuous representations. Interestingly, both enhancement and depression were observed following both plasticity paradigms. Furthermore, plasticity was not restricted by the border's presence. Depolarization in the absence of synaptic stimulation also produced synaptic plasticity, but with different characteristics. These experiments suggest that plasticity of horizontal connections may mediate functional reorganization.
The GRK2 Overexpression Is a Primary Hallmark of Mitochondrial Lesions during Early Alzheimer Disease
Authors: Obrenovich Mark E. , Palacios Hector H. , Gasimov Eldar , Leszek Jerzy , Aliev Gjumrakch
Published: March 2010

Increasing evidence points to vascular damage as an early contributor to the development of two leading causes of age-associated dementia, namely Alzheimer disease (AD) and AD-like pathology such as stroke. This review focuses on the role of G protein-coupled receptor kinases (GRKs) as they relate to dementia and how the cardio and cerebrovasculature is involved in AD pathogenesis. The exploration of GRKs in AD pathogenesis may help bridge gaps in our understanding of the heart-brain connection in relation to neurovisceral damage and vascular complications of AD. The a priori basis for this inquiry stems from the fact that kinases of this family regulate numerous receptor functions in the brain, myocardium and elsewhere. The aim of this review is to discuss the finding of GRK2 overexpression in the context of early AD pathogenesis. Also, we consider the consequences for this overexpression as a loss of G-protein coupled receptor (GPCR) regulation, as well as suggest a potential role for GPCRs and GRKs in a unifying theory of AD pathogenesis through the cerebrovasculature. Finally, we synthesize this newer information in an attempt to put it into context with GRKs as regulators of cellular function, which makes these proteins potential diagnostic and therapeutic targets for future pharmacological intervention.
Naval Target Classification by Fusion of Multiple Imaging Sensors Based on the Confusion Matrix
Authors: Giompapa S. , Farina A. , Gini F. , Graziano A. , Croci R. , Di Stefano R.
Published: March 2010

This paper presents an algorithm for the classification of targets based on the fusion of the class information provided by different imaging sensors. The outputs of the different sensors are combined to obtain an accurate estimate of the target class. The performance of each imaging sensor is modelled by means of its confusion matrix (CM), whose elements are the conditional error probabilities in the classification and the conditional correct classification probabilities. These probabilities are used by each sensor to make a decision on the target class. Then, a final decision on the class is made using a suitable fusion rule in order to combine the local decisions provided by the sensors. The overall performance of the classification process is evaluated by means of the “fused” confusion matrix, i.e. the CM pertinent to the final decision on the target class. Two fusion rules are considered: a majority voting (MV) rule and a maximum likelihood (ML) rule. A case study is then presented, where the developed algorithm is applied to three imaging sensors located on a generic air platform: a video camera, an infrared camera (IR), and a spotlight Synthetic Aperture Radar (SAR).
Papillocystic Variant of Acinar Cell Pancreatic Carcinoma
Authors: Radhi Jasim , Tse France , Marcaccio Michael
Published: March 2010

Acinar cell pancreatic carcinoma is a rare solid malignant neoplasm. Recent review of the literature showed occasional cases with papillary or papillocystic growth patterns, ranging from 2 to 5 cm in diameter. We report a large 10 cm pancreatic tumor with papillocystic pathology features involving the pancreatic head. The growth pattern of these tumors could be mistaken for intraductal papillary mucinous tumors or other pancreatic cystic neoplasms.
Neutrophils Compromise Retinal Pigment Epithelial Barrier Integrity
Authors: Zhou Jiehao , He Shikun , Zhang Ning , Spee Christine , Zhou Peng , Ryan Stephen J. , Kannan Ram , Hinton David R.
Published: March 2010

We hypothesized that neutrophils and their secreted factors mediate breakdown of the integrity of the outer blood-retina-barrier by degrading the apical tight junctions of the retinal pigment epithelium (RPE). The effect of activated neutrophils or neutrophil cell lysate on apparent permeability of bovine RPE-Choroid explants was evaluated by measuring[H]mannitol flux in a modified Ussing chamber. The expression of matrix metalloproteinase- (MMP-) 9 in murine peritoneal neutrophils, and the effects of neutrophils on RPE tight-junction protein expression were assessed by confocal microscopy and western blot. Our results revealed that basolateral incubation of explants with neutrophils decreased occludin and ZO-1 expression at 1 and 3 hours and increased the permeability of bovine RPE-Choroid explants by >3-fold (P<.05). Similarly, basolateral incubation of explants with neutrophil lysate decreased ZO-1 expression at 1 and 3 hours (P<.05) and increased permeability of explants by 75%. Further, we found that neutrophils prominently express MMP-9 and that incubation of explants with neutrophils in the presence of anti-MMP-9 antibody inhibited the increase in permeability. These data suggest that neutrophil-derived MMP-9 may play an important role in disrupting the integrity of the outer blood-retina barrier.
Effects of Landform on Site Index for Two Mesophytic Tree Species in the Appalachian Mountains of North Carolina, USA
Authors: McNab W. Henry
Published: March 2010

The effects of soil and topographic variables on forest site index were determined for two mesophytic tree species, northern red oak (Quercus rubraL.) and yellow-poplar (Liriodendron tulipiferaL.) in the Southern Appalachian Mountains of North Carolina. Stand variables included soil solum thickness, soil A-horizon thickness, elevation, aspect, slope gradient, and landform index. Landform index is a recently devised environmental variable that has been used to quantify the influence of topography surrounding a stand on productivity. Regression analysis indicated that among the variables only landform index had a significant () relationship with site index and explained 46 percent of the variation for northern red oak and 56 percent for yellow-poplar. Plot data from this study were also used to validate a previously developed prediction equation for estimating yellow-poplar site index and results indicated that unbiased estimates would be within 2.5 m. Results from this study suggest that landform accounts for variation in site index of mesophytic species in mountainous terrain that is not explained by conventional stand variables associated with soil and topography.
Furuta′s Pendulum: AConservativeNonlinear Model for Theory and Practise
Authors: Acosta J. Á.
Published: March 2010

Furuta′s pendulum has been an excellent benchmark for the automatic control community in the last years, providing, among others, a better understanding of model‐based Nonlinear Control Techniques. Since most of these techniques are based on invariants and/or integrals of motion then, the dynamic model plays an important role. This paper describes, in detail, the successful dynamical model developed for the available laboratory pendulum. The success relies on a basic dynamical model derived from Classical Mechanics which has been augmented to compensate thenon-conservativetorques. Thus, thequasi-conservative“practical” model developed allows to design all the controllers as if the system was strictlyconservative. A survey of all the nonlinear controllers designed and experimentally tested on the available laboratory pendulum is also reported.
Massive Fetomaternal Hemorrhage Caused by an Intraplacental Choriocarcinoma: A Case Report
Authors: Henningsen Anna-Karina Aaris , Maroun Lisa Leth , Havsteen Hanne , Svare Jens
Published: March 2010

Background. Intraplacental choriocarcinoma is a rare but highly malignant trophoblastic neoplasm. When found near term the risk of maternal metastasis is high because of the late diagnosis.Case. We describe a case of an intraplacental choriocarcinoma diagnosed postpartum after a near-term delivery of a severely anemic infant. A fetomaternal hemorrhage resulted in a hemoglobin concentration in the infant of only 2,1 g/dL. Neither mother nor child showed signs of metastatic disease. The macroscopic examination showed a hydropic placenta weighing more than 1 kilogram. Microscopy showed an intraplacental choriocarcinoma 3 cm in diameter. The tumor had infiltrated the maternal basal plate.Conclusion. Fetomaternal bleeding is a rare form of presentation of choriocarcinoma but its presence should always warrant detailed examination of placenta, mother, and infant.
Acquired Haemophilia A in the Elderly: Case Reports
Authors: Tufano Antonella , Coppola Antonio , Guida Anna , Cimino Ernesto , De Gregorio Angela Maria , Cerbone Anna Maria , Di Minno Giovanni
Published: March 2010

Acquired hemophilia A (AHA) is a very rare disease, caused by the development of autoantibodies, directed against circulating factor VIII of coagulation. Age distribution is bimodal, with a first peak occurring among young women in the postpartum period, and a second major peak of incidence among elderly patients in whom it is frequently associated with malignancy and drugs. This disease often represents a life-threatening bleeding condition, especially in the elderly, thus requiring a prompt therapeutic intervention, including control of acute bleeding and eradication of the inhibitor by immunosuppressive therapy. The diagnosis of AHA should be considered in any elderly patient who presents with bleeding and prolonged activated Partial Thromboplastin Time. Moreover, the coexistence of a series of underlying diseases associated with AHA should be always searched for. An early recognition and an adequate treatment of this coagulation disorder and of the possible associated diseases play a significant role for a favourable outcome, but concomitant morbidities in the elderly may limit aggressive therapy and may complicate the clinical scenario. We report 3 consecutive elderly patients successfully treated with recombinant activated factor VII and standard immunosuppressive regimens, with remission of the disease.
Complementary Actions of Inhibitors of Angiopoietin-2 and VEGF on Tumor Angiogenesis and Growth
Authors: Hashizume Hiroya , Falcón Beverly L. , Kuroda Takashi , Baluk Peter , Coxon Angela , Yu Dongyin , Bready James V. , Oliner Jonathan D. , McDonald Donald M.
Published: March 2010

Inhibition of angiopoietin-2 (Ang2) can slow tumor growth, but the underlying mechanism is not fully understood. Because Ang2 is expressed in growing blood vessels and promotes angiogenesis driven by vascular endothelial growth factor (VEGF), we asked whether the antitumor effect of Ang2 inhibition results from reduced sprouting angiogenesis and whether the effect is augmented by inhibition of VEGF from tumor cells. Using Colo205 human colon carcinomas in nude mice as a model, we found that selective inhibition of Ang2 by the peptide-Fc fusion protein L1-7(N) reduced the number of vascular sprouts by 46% and tumor growth by 62% over 26 days. Strikingly, when the Ang2 inhibitor was combined with a function-blocking anti-VEGF antibody, the number of sprouts was reduced by 82%, tumor vascularity was reduced by 67%, and tumor growth slowed by 91% compared with controls. The reduction in tumor growth was accompanied by decreased cell proliferation and increased apoptosis. We conclude that inhibition of Ang2 slows tumor growth by limiting the expansion of the tumor vasculature by sprouting angiogenesis, in a manner that is complemented by concurrent inhibition of VEGF and leads to reduced proliferation and increased apoptosis of tumor cells. Cancer Res; 70(6); 2213–23
CD44 Attenuates Activation of the Hippo Signaling Pathway and Is a Prime Therapeutic Target for Glioblastoma
Authors: Xu Yin , Stamenkovic Ivan , Yu Qin
Published: March 2010

Glioblastoma multiforme (GBM) is the most aggressive brain tumor that, by virtue of its resistance to chemotherapy and radiotherapy, is currently incurable. Identification of molecules whose targeting may eliminate GBM cells and/or sensitize glioblastoma cells to cytotoxic drugs is therefore urgently needed. CD44 is a major cell surface hyaluronan receptor and cancer stem cell marker that has been implicated in the progression of a variety of cancer types. However, the major downstream signaling pathways that mediate its protumor effects and the role of CD44 in the progression and chemoresponse of GBM have not been established. Here we show that CD44 is upregulated in GBM and that its depletion blocks GBM growth and sensitizes GBM cells to cytotoxic drugs in vivo. Consistent with this observation, CD44 antagonists potently inhibit glioma growth in preclinical mouse models. We provide the first evidence that CD44 functions upstream of the mammalian Hippo signaling pathway and that CD44 promotes tumor cell resistance to reactive oxygen species–induced and cytotoxic agent–induced stress by attenuating activation of the Hippo signaling pathway. Together, our results identify CD44 as a prime therapeutic target for GBM, establish potent antiglioma efficacy of CD44 antagonists, uncover a novel CD44 signaling pathway, and provide a first mechanistic explanation as to how upregulation of CD44 may constitute a key event in leading to cancer cell resistance to stresses of different origins. Finally, our results provide a rational explanation for the observation that functional inhibition of CD44 augments the efficacy of chemotherapy and radiation therapy. Cancer Res; 70(6); 2455–64
Suppression of Tumor Growth and Metastasis by Simultaneously Blocking Vascular Endothelial Growth Factor (VEGF)–A and VEGF-C with a Receptor-Immunoglobulin Fusion Protein
Authors: Zhang Dapeng , Li Bohua , Shi Jingping , Zhao Lei , Zhang Xunming , Wang Chong , Hou Sheng , Qian Weizhu , Kou Geng , Wang Hao , Guo Yajun
Published: March 2010

The major cause of cancer mortality is the metastatic spread of tumor cells that can occur via multiple routes, including the vascular system and the lymphatic system. In this study, we developed an IgG-like fusion protein molecule [vascular endothelial growth factor (VEGF) receptor 31–immunoglobulin (VEGFR31-Ig)] which could simultaneously bind the angiogenic growth factor VEGF-A and the lymphangiogenic growth factor VEGF-C. Importantly, VEGFR31-Ig exhibited VEGF-A–binding affinity similar to that of VEGFTrap, the most potent VEGF-A binder, and VEGF-C–binding affinity comparable with that of the soluble fusion protein VEGFR3-Ig (sVEGFR3). Pharmacokinetic analysis in mice showed that VEGFR31-Ig had improved pharmacokinetic properties compared with either VEGFTrap or sVEGFR3. In a highly metastatic human hepatocellular carcinoma (HCCLM3) model in severe combined immunodeficient mice, VEGFR31-Ig potently blocked both tumor angiogenesis and lymphangiogenesis, effectively inhibiting primary tumor growth and metastasis to lungs and lymph nodes. In contrast, VEGFTrap only suppressed primary tumor growth and metastasis to lungs by inhibiting tumor angiogenesis, whereas VEGFR3 was only effective in suppressing tumor metastasis to lymph nodes by blocking tumor lymphangiogenesis. Although a combination of VEGFTrap (25 mg/kg twice weekly) and sVEGFR3 (25 mg/kg twice weekly) can achieve the same therapeutic effect as VEGFR31-Ig (25 mg/kg twice weekly) in the HCCLM3 xenograft mouse model, developing two separate receptor-Ig fusion proteins for clinical use as combination therapy is impractical, mainly owing to regulatory hurdles and cost. Taken together, the VEGFR31-Ig fusion protein presented here has been suggested to have great potential for the treatment of metastatic cancer. Cancer Res; 70(6); 2495–503
Pooled Analysis of Phosphatidylinositol 3-Kinase Pathway Variants and Risk of Prostate Cancer
Authors: Koutros Stella , Schumacher Fredrick R. , Hayes Richard B. , Ma Jing , Huang Wen-Yi , Albanes Demetrius , Canzian Federico , Chanock Stephen J. , Crawford E. David , Diver W. Ryan , Feigelson Heather Spencer , Giovanucci Edward , Haiman Christopher A. , Henderson Brian E. , Hunter David J. , Kaaks Rudolf , Kolonel Laurence N. , Kraft Peter , Le Marchand Loïc , Riboli Elio , Siddiq Afshan , Stampfer Mier J. , Stram Daniel O. , Thomas Gilles , Travis Ruth C. , Thun Michael J. , Yeager Meredith , Berndt Sonja I.
Published: March 2010

The phosphatidylinositol 3-kinase (PI3K) pathway regulates various cellular processes, including cellular proliferation and intracellular trafficking, and may affect prostate carcinogenesis. Thus, we explored the association between single-nucleotide polymorphisms (SNP) in PI3K genes and prostate cancer. Pooled data from the National Cancer Institute Breast and Prostate Cancer Cohort Consortium were examined for associations between 89 SNPs in PI3K genes (PIK3C2B, PIK3AP1, PIK3C2A, PIK3CD, and PIK3R3) and prostate cancer risk in 8,309 cases and 9,286 controls. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated using logistic regression. SNP rs7556371 in PIK3C2B was significantly associated with prostate cancer risk [ORper allele, 1.08 (95% CI, 1.03–1.14); Ptrend = 0.0017] after adjustment for multiple testing (Padj = 0.024). Simultaneous adjustment of rs7556371 for nearby SNPs strengthened the association [ORper allele, 1.21 (95% CI, 1.09–1.34); Ptrend = 0.0003]. The adjusted association was stronger for men who were diagnosed before the age of 65 years [ORper allele, 1.47 (95% CI, 1.20–1.79); Ptrend = 0.0001] or had a family history [ORper allele = 1.57 (95% CI, 1.11–2.23); Ptrend = 0.0114], and was strongest in those with both characteristics [ORper allele = 2.31 (95% CI, 1.07–5.07), P-interaction = 0.005]. Increased risks were observed among men in the top tertile of circulating insulin-like growth factor-I (IGF-I) levels [ORper allele = 1.46 (95% CI, 1.04–2.06); Ptrend = 0.075]. No differences were observed with disease aggressiveness (Gleason grade ≥8 or stage T3/T4 or fatal). In conclusion, we observed a significant association between PIK3C2B and prostate cancer risk, especially for familial, early-onset disease, which may be attributable to IGF-dependent PI3K signaling. Cancer Res; 70(6); 2389–96