bluuebunny/crossref_metadata_2025 huggingface dataset:
Vehicle Collision into Steel Pedestrian Bridges
Authors: Salokangas Lauri , Sauna-Aho Niko
Published: June 2013

During 2010 a few steel footbridges collapsed in Finland as a result of over-height vehicles collid-ing into the superstructure. This caused an investigation into horizontal impact loads on superstruc-tures of pedestrian bridges and the magnitude of the collision force. To analyze the collision numer-ically, many parameters must be taken into account and a dynamic structural analysis must be per-formed. The magnitude of impact is strongly affected by the mass distributions and rigidities of the colliding vehicle and the bridge during the collision, as well as vehicle velocity, damping, changes in the geometry of both objects, the nature of the contact surface and resulting energy losses etc. The duration of collision time is short, usually only fraction of seconds, causing difficulties in the numerical analysis. In this paper a vehicle collision on bridge deck is reported. Collision forces of design codes are compared to the values obtained by simple spring mass system and results ob-tained by using dynamic nonlinear finite element analysis.
Failures of Dams – Challenges to the Present and the Future
Authors: Vogel Alexius
Published: June 2013

Under the aspect of recent flood events in Europe and many other countries in the world the safety of water retaining structures and the threat of dam failures, connected with economical and human damages are facts of our daily life. If we consider that such events are global realities and strike all countries, the world-wide communities are confronted in average with one dam failure per week and with the failure of a large dam every two months. Catastrophic failures of levees and dikes which strike in some times also historical constructions which stand in operation under flood condi-tions during very short periods within a year have changed the opinion that low dams are construc-tions without risks. Every time failures of tailings dams connected with the loss of the constructions and the outbursts of storages are connected with pollutions of environments. After the destruction of any kind of storage facilities investigations are executed to assess the circumstances and investigate the causes and impacts of such events, knowledge which must be stored for the future.
Robustness of Structures
Authors: Vogel Thomas
Published: June 2013

Robustness has become an important general requirement for both, design of new and evaluation of existing structures, to reduce the global risk caused by structures. Methods to achieve robustness are presented in a systematic order and illustrated by examples. Some important issues to get robust structures are addressed like strength, stiffness, ductility, strain hardening, and continuity. Different definitions of robustness are presented, showing that they slowly converge. Some proposed metrics are discussed, although they are not yet practically applicable. With a example of a bolted steel splice, it can be shown that even in a simple detail robustness as a design criterion may be ambiguous. Finally, the implicit and explicit treatment of robustness in former and actual codes is covered and developments for the future are sketched.
Germany's Energy Transition Under Attack: Is There an Inscrutable German Sonderweg ?
Authors: Gawel Erik , Strunz Sebastian , Lehmann Paul
Published: June 2013

The German energy transition repeatedly faces harsh critiques questioning its economic and environmental merits. This article defends the energy transition and argues that Germany has chosen an economically efficient and particularly forceful approach to securing a sustainable energy supply. Though current expenditures are high, the long-term benefits of transforming the energy system to a renewables-based system are likely to outweigh present investment costs. Furthermore, support policies for renewables are not redundant-as some critics claim-but instead complement other policy instruments, such as the emissions trading scheme. This article also addresses the motives behind the discrediting attacks on the German energy policy regime. Defensive actions by beneficiaries of the former energy market structure are only to be expected, but the attacks from liberal economists are astonishingly fierce.
Reflexive Shifts in Climate Research and Education: Toward Relocalizing Our Lives
Authors: Leduc Timothy B. , Crate Susan A
Published: June 2013

This article is concerned with the way in which indigenous place-based knowledge and understandings, in a time of global climate change, have the potential to challenge researchers to self-reflexively shift the focus of their research toward those technological and consumer practices that are the cultural context of our research. After reviewing some literature on the emergence of self-reflexivity in research, the authors offer two case studies from their respective environmental education and anthropological research with northern indigenous cultures that clarifies the nature of a self-reflexive turn in place-based climate research and education. The global interconnections between northern warming and consumer culture-and its relation to everexpanding technological systems-are considered by following the critical insights of place-based knowledge. We conclude by examining the possibility that relocalizing our research, teaching, and ways of living in consumer culture are central to a sustainable future, and if so, the knowledge and understandings of current place-based peoples will be vital to envisioning such a cultural transformation of our globalizing system.
Converting Community Knowledge into Catchment Nutrient Limits: A Constructivist Analysis of a New Zealand Collaborative Approach to Water Management
Authors: Duncan Ronlyn
Published: June 2013

The question posed in this article is how shifts in governance ushered in by the sustainability paradigm are reshaping knowledge governance. Drawing on constructivist theories of knowledge, I examine the tension between the sustainability mandate to open up knowledge making to local knowledge, and conventional science policy practice that would see it excluded. I present a water management case study from New Zealand's South Island region of Canterbury, where communities are involved in establishing catchment nutrient limits to manage land use and water quality. It is concluded that although local knowledge was embraced within the knowledge-making process, the pursuit of epistemic authority led to its recalibration, aggregation, and standardization. As such, it was stripped of its complexity. This research highlights the role of politics in anchoring the linear knowledge governance model in place and the challenge for supplanting it.
Single-fraction radiosurgery of benign cavernous sinus meningiomas
Authors: Pollock Bruce E. , Stafford Scott L. , Link Michael J. , Garces Yolanda I. , Foote Robert L.
Published: June 2013

Object

Stereotactic radiosurgery (SRS) is an important treatment option for patients with cavernous sinus meningiomas (CSM). To analyze factors associated with local tumor control and complications after single-fraction SRS, the authors reviewed cases involving patients treated with Gamma Knife SRS between 1990 and 2008.

Methods

Excluded were patients with WHO Grade II or III tumors, radiation-induced tumors, multiple meningiomas, neurofibromatosis Type 2, and prior or concurrent radiotherapy. Five patients were lost to follow-up and 3 patients refused research authorization. The remaining 115 patients (29 men, 86 women) had either histologically confirmed WHO Grade I (n = 46, 40%) or presumed (n = 69, 60%) CSM. The median treatment volume was 9.3 cm3 (range 1.3–42.2 cm3). The median margin dose was 16 Gy (range 12–20 Gy). The median follow-up after SRS was 89 months (range 12–251 months). Thirty-nine patients (34%) had 10 or more years of follow-up after SRS.

Results

Six patients (5%) had tumor progression (in field, n = 3; marginal, n = 3) at a median of 74 months (range 42–145 months) after SRS. The local tumor control rate was 99% at 5 years and 93% at 10 years after SRS. No analyzed factor was associated with local control after SRS. Fourteen patients (12%) had permanent complications at a median onset of 23 months (range 2–146 months) including trigeminal dysfunction (n = 9), diplopia (n = 2), ischemic stroke (n = 2), and hypopituitarism (n = 1). The 2-year, 5-year, and 10-year rates of complications were 7%, 10%, and 15%, respectively. Multivariate analysis found larger treatment volume (HR 1.1, 95% CI 1.02–1.2, p = 0.01) to be associated with complications after SRS. The complication rate for patients with a treatment volume of 9.3 cm3 or less was 3% (2 of 58 cases) compared with 21% (12 of 57 cases) for patients with a treatment volume greater than 9.4 cm3.

Conclusions

Single-fraction SRS at the radiation doses used in this series provided durable tumor control for patients with benign CSM. Larger tumor volume remains the primary factor associated with complications after single-fraction SRS of benign CSM despite advancements in SRS technique.
Lack of functional patency of the lamina terminalis after fenestration following clipping of anterior circulation aneurysms
Authors: Chohan Muhammad Omar , Carlson Andrew P. , Hart Blaine L. , Yonas Howard
Published: June 2013

Object

Fenestration of the lamina terminalis (FLT) during aneurysm surgery for subarachnoid hemorrhage can, in theory, improve CSF circulation from the lateral and third ventricles to the cortical subarachnoid space, which may, in turn, decrease the incidence of hydrocephalus and vasospasm. However, the actual effects of FLT on CSF circulation have been difficult to determine, due to confounding factors. In addition, it is unclear whether the lamina terminalis remains functionally patent when the brain resumes its normal position. The goal of this study was to assess the functional patency of the fenestrated lamina terminalis in patients who underwent surgery for ruptured aneurysms.

Methods

This prospective study included 15 patients who underwent surgical clipping of ruptured anterior circulation aneurysms, with FLT performed during surgery. On postoperative Day 1, the external ventricular drain of each patient was closed, and 1 ml of Omnipaque 300, an iodine based contrast agent, was injected intraventricularly, accompanied by cranial maneuvering designed to position the contrast agent adjacent to the lamina terminalis. Three to 5 minutes after cranial maneuvering, the flow of contrast agent into the basal cisterns was assessed with CT imaging. Flow was verified by an increase in Hounsfield units in a prespecified “region of interest” within the basal cisterns on the CT scan. This procedure was performed using a standardized protocol designed in consultation with the Department of Radiology and approved by the institutional review board. One patient who underwent endoscopic third ventriculostomy was recruited as a positive control to validate the technique, and 1 patient who underwent aneurysm clipping but not FLT was recruited as a negative control.

Results

Seventeen patients consented to study participation. In the 15 patients who underwent aneurysm clipping and FLT, and the negative control patient who underwent aneurysm clipping but not FLT, the contrast agent followed the normal ventricular pathway from the lateral ventricles into the fourth ventricle, and did not appear in the basal cisterns. In the positive control patient, the contrast agent robustly and immediately filled the basal cisterns.

Conclusions

Fenestration of the lamina terminalis did not result in functional patency of the lamina terminalis when performed as part of surgical clipping for ruptured aneurysms.
United Kingdom 30-day mortality rates after surgery for pediatric central nervous system tumors
Authors: O'Kane Roddy , Mathew Ryan , Kenny Tom , Stiller Charles , Chumas Paul
Published: June 2013

Object

In an increasing culture of medical accountability, 30-day operative mortality rates remain one of the most objective measurements reported for the surgical field. The authors report population-based 30-day postoperative mortality rates among children who had undergone CNS tumor surgery in the United Kingdom.

Methods

To determine overall 30-day operative mortality rates, the authors analyzed the National Registry of Childhood Tumors for CNS tumors for the period 2004–2007. The operative mortality rate for each tumor category was derived. In addition, comparison was made with the 30-day operative mortality rates after CNS tumor surgery reported in the contemporary literature. Finally, by use of a funnel plot, institutional performance for 30-day operative mortality was compared for all units across the United Kingdom.

Results

The overall 30-day operative mortality rate for children undergoing CNS tumor surgery in the United Kingdom during the study period was 2.7%. When only malignant CNS tumors were analyzed, the rate increased to 3.5%. One third of the deaths occurred after discharge from the hospital in which the surgery had been performed. The highest 30-day operative mortality rate (19%) was for patients with choroid plexus carcinomas. A total of 20 institutions performed CNS tumor surgery during the study period. Rates for all institutions fell within 2 SDs. No trend associating operative mortality rates and institutional volume was found. In comparison, review of the contemporary literature suggests that the postoperative mortality rate should be approximately 1%.

Conclusions

The authors believe this to be the first report of national 30-day surgical mortality rates specifically for children with CNS tumors. The study raises questions about the 30-day mortality rate among children undergoing surgery for CNS tumors. International consensus should be reached on a minimum data set for outcomes and should include 30-day operative mortality rates.
Validation and modification of a predictive model of postresection hydrocephalus in pediatric patients with posterior fossa tumors
Authors: Foreman Paul , McClugage Samuel , Naftel Robert , Griessenauer Christoph J. , Ditty Benjamin J. , Agee Bonita S. , Riva-Cambrin Jay , Wellons John
Published: June 2013

Object

Postresection hydrocephalus is observed in approximately 30% of pediatric patients with posterior fossa tumors. However, which patients will develop postresection hydrocephalus is not known. The Canadian Preoperative Prediction Rule for Hydrocephalus (CPPRH) was developed in an attempt to identify this subset of patients, allowing for the optimization of their care. The authors sought to validate and critically appraise the CPPRH.

Methods

The authors conducted a retrospective chart review of 99 consecutive pediatric patients who presented between 2002 and 2010 with posterior fossa tumors and who subsequently underwent resection. The data were then analyzed using bivariate and multivariate analyses, and a modified CPPRH (mCPPRH) was applied.

Results

Seventy-six patients were evaluated. Four variables were found to be significant in predicting postresection hydrocephalus: age younger than 2 years, moderate/severe hydrocephalus, preoperative tumor diagnosis, and transependymal edema. The mCPPRH produced observed likelihood ratios of 0.737 (95% CI 0.526–1.032) and 4.688 (95% CI 1.421–15.463) for low- and high-risk groups, respectively.

Conclusions

The mCPPRH utilizes readily obtainable and reliable preoperative variables that together stratify children with posterior fossa tumors into high- and low-risk categories for the development of postresection hydrocephalus. This new predictive model will aid patient counseling and tailor the intensity of postoperative clinical and radiographic monitoring for hydrocephalus, as well as provide evidence-based guidance for the use of prophylactic CSF diversion.
The impact of early recovery on long-term outcomes in a cohort of patients undergoing prolonged nonoperative treatment for lumbar disc herniation
Authors: Cowperthwaite Matthew C. , van den Hout Wilbert B. , Webb K. Michael
Published: June 2013

Object

The authors comprehensively studied the recovery of individual patients undergoing treatment for lumbar disc herniation. The primary goal was to gain insight into the variability of individual patient utility scores within a treatment cohort. The secondary goal was to determine how the rates and variability of patient recovery over time, represented by improvement in utility scores, affected long-term patient outcomes.

Methods

EuroQol Group–5 Dimension (EQ-5D) scores were obtained at baseline and at 2, 4, 8, 12, 26, 38, and 52 weeks for 93 patients treated under a prolonged conservative care protocol for lumbar disc herniation. Gaussian kernel densities were used to estimate the distribution of utility scores at each time point. Logistic regression and multistate Markov models were used to characterize individual patient improvement over time. Fisher exact tests were used to compare the distribution of EQ-5D domain scores.

Results

The distribution of utility scores was bimodal at 1 year and effectively sorted patients into a “higher” utility group (EQ-5D = 1; 43% of cohort) and a “lower” utility group (EQ-5D ≤ 0.86; 57% of cohort). Fisher exact tests revealed that pain/discomfort, mobility, and usual activities significantly differed between the 2 utility groups (p ≪ 0.001). The utility groups emerged at 8 weeks and were stable for the remainder of the treatment period. Using utility scores from 8 weeks, regression models predicted 1-year outcomes with 62% accuracy.

Conclusions

This study is the first to comprehensively consider the utility recovery of individual patients within a treatment cohort for lumbar disc herniation. The results suggest that most utility is recovered during the early treatment period. Moreover, the findings suggest that initial improvement is critical to a patient's long-term outcome: patients who do not experience significant initial recovery appear unlikely to do so at a later time under the same treatment protocol.
In Vivo Secretion of Bispecific Antibodies Recruiting Lymphocytic Effector Cells
Authors: Compte Marta , Nuñez-Prado Natalia , Sanz Laura , Alvarez-Vallina Luis
Published: June 2013

Engineered Fc-lacking bispecific antibodies have shown an exceptionally high potency for recruiting lymphocyte effector cells and enhancing antitumor activity, which is under evaluation in several clinical trials. However, current treatment regimens raise some issues that should be considered, such as the high cost of clinical-grade bispecific antibodies and the achievement of sustained therapeutic plasma levels. The use of gene transfer methods may circumvent problems related to large-scale production and purification, and result in sustained therapeutic plasma concentrations of the Fc-lacking bispecific antibodies. In fact, terminally differentiated cells and non-terminally differentiated cells can be genetically modified to secrete functionally active bispecific antibodies exerting clear anti-tumor effects. This review highlights the relevance of different promising strategies for in vivo delivery of therapeutic bispecific antibodies.
A Versatile Tool for Stable Inhibition of microRNA Activity
Authors: Pelucchi Paride , Tria Valeria , Martino Valentina , Sabour Davood , Bertalot Giovanni , Molgora Stefano , Palizban Mira , Götte Martin , Zucchi Ileana , Reinbold Rolland
Published: June 2013

MicroRNAs (miRNAs) are a class of small RNAs (18–22 nt) that post transcriptionally regulate gene expression by binding to complementary sequences on target mRNAs, resulting in translational repression or target degradation and gene silencing. As aberrant expression of miRNAs is implicated in important diseases including cancer miRNA-based therapies are under intensive investigation. We optimized strategies to stably or conditionally generate miRNA inhibitors for a continuous block of miRNA activity that allows for probing miRNA function in long-term cell culture experiments, cancer xenografts, 3D tissue models and for in vivo studies with transgenic organisms.
Memory Deficits in Schizophrenia: A Selective Review of Functional Magnetic Resonance Imaging (fMRI) Studies
Authors: Kraguljac Nina , Srivastava Annusha , Lahti Adrienne
Published: June 2013

Schizophrenia is a complex chronic mental illness that is characterized by positive, negative and cognitive symptoms. Cognitive deficits are most predictive of long-term outcomes, with abnormalities in memory being the most robust finding. The advent of functional magnetic resonance imaging (fMRI) has allowed exploring neural correlates of memory deficits in vivo. In this article, we will give a selective review of fMRI studies probing brain regions and functional networks that are thought to be related to abnormal memory performance in two memory systems prominently affected in schizophrenia; working memory and episodic memory. We revisit the classic “hypofrontality” hypothesis of working memory deficits and explore evidence for frontotemporal dysconnectivity underlying episodic memory abnormalities. We conclude that fMRI studies of memory deficits in schizophrenia are far from universal. However, the current literature does suggest that alterations are not isolated to a few brain regions, but are characterized by abnormalities within large-scale brain networks.
Quantification of High-Molecular Weight Protein Platforms by AQUA Mass Spectrometry as Exemplified for the CD95 Death-Inducing Signaling Complex (DISC)
Authors: Warnken Uwe , Schleich Kolja , Schnölzer Martina , Lavrik Inna
Published: June 2013

Contemporary quantitative mass spectrometry provides fascinating opportunities in defining the stoichiometry of high-molecular weight complexes or multiprotein platforms. The composition stoichiometry of multiprotein platforms is a key to understand the regulation of complex signaling pathways and provides a basis for constructing models in systems biology. Here we present an improved AQUA technique workflow that we adapted for the quantitative mass spectrometry analysis of the stoichiometry of the CD95 (Fas/APO-1) death inducing signaling complex (DISC). The DISC is a high-molecular weight platform essential for the initiation of CD95-mediated apoptotic and non-apoptotic responses. For protein quantification, CD95 DISCs were immunoprecipitated and proteins in the immunoprecipitations were separated by one-dimensional gel electrophoresis, followed by protein quantification using the AQUA technique. We will discuss in detail AQUA analysis of the CD95 DISC focusing on the key issues of this methodology, i.e., selection and validation of AQUA peptides. The application of this powerful method allowed getting new insights into mechanisms of procaspase-8 activation at the DISC and apoptosis initiation [1]. Here we discuss the AQUA methodology adapted by us for the analysis of the CD95 DISC in more detail. This approach paves the way for the successful quantification of multiprotein complexes and thereby delineating the intrinsic details of molecular interactions.
The Role of Tricho-Rhino-Phalangeal Syndrome (TRPS) 1 in Apoptosis during Embryonic Development and Tumor Progression
Authors: Sun Yujing , Gui Ting , Shimokado Aiko , Muragaki Yasuteru
Published: June 2013

TRPS1 is a GATA-type transcription factor that is closely related to human tricho-rhino-phalangeal syndrome (TRPS) types I and III, variants of an autosomal dominant skeletal disorder. During embryonic development, Trps1 represses Sox9 expression and regulates Wnt signaling pathways that determine the number of hair follicles and their normal morphogenesis. In the growth plate, Trps1 regulates chondrocytes condensation, proliferation, and maturation and phalangeal joint formation by functioning downstream of Gdf5 signaling and by targeting at Pthrp, Stat3 and Runx2. Also, Trps1 protein directly interacts with an activated form of Gli3. In embryonic kidneys, Trps1 functions downstream of BMP7 promoting the mesenchymal-to-epithelial transition, and facilitating tubule morphogenesis and ureteric bud branching. Moreover, Trps1 has been found to be closely related to tumorigenesis, invasion, and metastasis in prostate and breast cancers. It is interesting to note that during the development of hair follicles, bones, and kidneys, mutations in Trps1 cause, either directly or through crosstalk with other regulators, a notable change in cell proliferation and cell death. In this review, we will summarize the most recent studies on Trps1 and seek to elucidate the role for Trps1 in apoptotic regulation.
Fact-Checking Ziegler’s Maximum Entropy Production Principle beyond the Linear Regime and towards Steady States
Authors: Polettini Matteo
Published: June 2013

We challenge claims that the principle of maximum entropy production produces physical phenomenological relations between conjugate currents and forces, even beyond the linear regime, and that currents in networks arrange themselves to maximize entropy production as the system approaches the steady state. In particular: (1) we show that Ziegler’s principle of thermodynamic orthogonality leads to stringent reciprocal relations for higher order response coefficients, and in the framework of stochastic thermodynamics, we exhibit a simple explicit model that does not satisfy them; (2) on a network, enforcing Kirchhoff’s current law, we show that maximization of the entropy production prescribes reciprocal relations between coarse-grained observables, but is not responsible for the onset of the steady state, which is, rather, due to the minimum entropy production principle.
The Analysis of the Aerodynamic Character and Structural Response of Large-Scale Wind Turbine Blades
Authors: Cai Xin , Pan Pan , Zhu Jie , Gu Rongrong
Published: June 2013

A process of detailed CFD and structural numerical simulations of the 1.5 MW horizontal axis wind turbine (HAWT) blade is present. The main goal is to help advance the use of computer-aided simulation methods in the field of design and development of HAWT-blades. After an in-depth study of the aerodynamic configuration and materials of the blade, 3-D mapping software is utilized to reconstruct the high fidelity geometry, and then the geometry is imported into CFD and structure finite element analysis (FEA) software for completely simulation calculation. This research process shows that the CFD results compare well with the professional wind turbine design and certification software, GH-Bladed. Also, the modal analysis with finite element method (FEM) predicts well compared with experiment tests on a stationary blade. For extreme wind loads case that by considering a 50-year extreme gust simulated in CFD are unidirectional coupled to the FE-model, the results indicate that the maximum deflection of the blade tip is less than the distance between the blade tip (the point of maximum deflection) and the tower, the material of the blade provides enough resistance to the peak stresses the occur at the conjunction of shear webs and center spar cap. Buckling analysis is also included in the study.
Design of a Hydraulic Motor System Driven by Compressed Air
Authors: Shaw Dein , Yu Jyun-Jhe , Chieh Cheng
Published: June 2013

This paper presents the design of a highly efficient pneumatic motor system. The air engine is currently the most generally used device to convert potential energy of compressed air into mechanical energy. However, the efficiency of the air engines is too low to provide sufficient operating range for the vehicle. In this study, the energy contained in compressed air/pressurized hydraulic oil is transformed by a hydraulic motor to mechanical energy to enhance the efficiency of using air power. To evaluate the theoretical efficiency, the principle of balance of energy is applied. The theoretical efficiency of converting air into hydraulic energy is found to be a function of pressure; thus, the maximum converting efficiency can be determined. To confirm the theoretical evaluation, a prototype of the pneumatic hydraulic system is built. The experiment verifies that the theoretical evaluation of the system efficiency is reasonable, and that the layout of the system is determined by the results of theoretical evaluation.
Evaluation of Ecotoxicological Risks Related to the Discharge of Combined Sewer Overflows (CSOs) in a Periurban River
Authors: Angerville Ruth , Perrodin Yves , Bazin Christine , Emmanuel Evens
Published: June 2013

Discharges of Combined Sewer Overflows (CSOs) into periurban rivers present risks for the concerned aquatic ecosystems. In this work, a specific ecotoxicological risk assessment methodology has been developed as management tool to municipalities equipped with CSOs. This methodology comprises a detailed description of the spatio-temporal system involved, the choice of ecological targets to be preserved, and carrying out bioassays adapted to each compartment of the river receiving CSOs. Once formulated, this methodology was applied to a river flowing through the outskirts of the city of Lyon in France. The results obtained for the scenario studied showed a moderate risk for organisms of the water column and a major risk for organisms of the benthic and hyporheic zones of the river. The methodology enabled identifying the critical points of the spatio-temporal systems studied, and then making proposals for improving the management of CSOs.
Detection of β-Lactamase Residues in Milk by Sandwich ELISA
Authors: Wang Wenbin , Liu Liqiang , Xu Liguang , Ma Wei , Kuang Hua , Xu Chuanlai
Published: June 2013

β-Lactamase residues in milk represent a public health risk. The cylinder plate detection method, which is based on bacterial growth, is laborious and time consuming. In this study, 15 monoclonal antibodies (mAbs) were selected against Temoneira (TEM) 1 β-lactamase. A sandwich enzyme-linked immunosorbent assay (ELISA) based on an optimum mAb pair was developed and validated for the detection of β-lactamase. The limit of detection and linear dynamic range of the method were 4.17 ng/mL and 5.5–100 ng/mL, respectively. β-Lactamase recovery in pure milk was 96.82–103.13%. The intra- and inter-assay coefficients of variation were 6.21–7.38% and 12.96–13.74%, respectively. Our developed sandwich ELISA can be used as a rapid detection method of β-lactamase in milk.
A Vacuolar Processing Enzyme RsVPE1 Gene of Radish Is Involved in Floral Bud Abortion under Heat Stress
Authors: Zhang Jing , Li Qing-Fei , Huang Wei-Wei , Xu Xiao-Yong , Zhang Xin-Ling , Hui Mai-Xia , Zhang Ming-Ke , Zhang Lu-Gang
Published: June 2013

Radish floral bud abortion (FBA) is an adverse biological phenomenon that occurs during reproduction. Although FBA is a frequent occurrence, its molecular mechanism remains unknown. A transcript-derived fragment (TDF72), which was obtained by cDNA amplified fragment length polymorphism (cDNA-AFLP), was up-regulated in the aborted buds and exhibited 89% sequence homology with the AtγVPE gene. In this study, TDF72 was used to clarify the role of VPE in FBA by isolation of the VPE gene RsVPE1 from radish flower buds. The full-length genomic DNA was 2346 bp including nine exons and eight introns. The full-length cDNA was 1825 bp, containing a complete open reading frame (ORF) of 1470 bp, which encoded a predicted protein containing 489 amino acid residues, with a calculated molecular mass of 53.735 kDa. Expression analysis demonstrated that RsVPE1 was expressed in all tested organs of radish at different levels. Highest expression was detected in aborted flower buds, suggesting that RsVPE1 has a role in FBA. In order to analyze the role of RsVPE1 in FBA, RsVPE1 was overexpressed in transgenic Arabidopsis thaliana plants. Aborted flower buds appeared in transgenic plants subjected to heat stress. In addition, RsVPE1 expression in the transgenic plants reached a maximum when subjected to heat stress for 24 h and increased by 2.1-fold to 2.8-fold in three homozygous transgenic lines. These results indicated that RsVPE1 led to FBA when its expression levels exceeded a particular threshold, and provided evidence for the involvement of RsVPE1 in promoting FBA under heat stress.
Kinetic Model for Signal Binding to the Quorum Sensing Regulator LasR
Authors: Claussen Anetta , Jakobsen Tim , Bjarnsholt Thomas , Givskov Michael , Welch Martin , Ferkinghoff-Borg Jesper , Sams Thomas
Published: June 2013

We propose a kinetic model for the activation of the las regulon in the opportunistic pathogen Pseudomonas aeruginosa. The model is based on in vitro data and accounts for the LasR dimerization and consecutive activation by binding of two OdDHL signal molecules. Experimentally, the production of the active LasR quorum-sensing regulator was studied in an Escherichia coli background as a function of signal molecule concentration. The functional activity of the regulator was monitored via a GFP reporter fusion to lasB expressed from the native lasB promoter. The new data shows that the active form of the LasR dimer binds two signal molecules cooperatively and that the timescale for reaching saturation is independent of the signal molecule concentration. This favors a picture where the dimerized regulator is protected against proteases and remains protected as it is activated through binding of two successive signal molecules. In absence of signal molecules, the dimerized regulator can dissociate and degrade through proteolytic turnover of the monomer. This resolves the apparent contradiction between our data and recent reports that the fully protected dimer is able to “degrade” when the induction of LasR ceases.
Non-Covalent Synthesis of Metal Oxide Nanoparticle–Heparin Hybrid Systems: A New Approach to Bioactive Nanoparticles
Authors: Vismara Elena , Valerio Antonio , Coletti Alessia , Torri Giangiacomo , Bertini Sabrina , Eisele Giorgio , Gornati Rosalba , Bernardini Giovanni
Published: June 2013

Heparin has been conjugated to Fe3O4, Co3O4, and NiO nanoparticles (NPs) through electrostatic interactions, producing colloidal suspensions of hybrid metal oxide heparin NPs that are stable in water. Negative zeta potentials and retention of heparin’s ability to capture toluidine blue indicate that heparin’s negative charges are exposed on the surface of the coated NPs. IR results confirmed the formation of nanohybrids as did NMR experiments, which were also interpreted on the basis of toluidine blue tests. Transmission electron microscopy results revealed that the heparin coating does not modify the shape or dimension of the NPs. Dynamic light scattering and negative zeta potential measurements confirmed that heparin surface functionalisation is an effective strategy to prevent NP aggregation.
In Vitro Antimetastatic Effect of Phosphatidylinositol 3-Kinase Inhibitor ZSTK474 on Prostate Cancer PC3 Cells
Authors: Zhao Wennan , Guo Wenzhi , Zhou Qianxiang , Ma Sheng-Nan , Wang Ran , Qiu Yuling , Jin Meihua , Duan Hong-Quan , Kong Dexin
Published: June 2013

Tumor metastasis is the main cause of lethality of prostate cancer, because conventional therapies like surgery and hormone treatment rarely work at this stage. Tumor cell migration, invasion and adhesion are necessary processes for metastasis. By providing nutrition and an escape route from the primary site, angiogenesis is also required for tumor metastasis. Phosphatidylinositol 3-kinases (PI3Ks) are well known to play important roles in tumorigenesis as well as metastasis. ZSTK474 is a specific PI3K inhibitor developed for solid tumor therapy. In the present report, antimetastatic activities of ZSTK474 were investigated in vitro by determining the effects on the main metastatic processes. ZSTK474 exhibited inhibitory effects on migration, invasion and adhesive ability of prostate cancer PC3 cells. Furthermore, ZSTK474 inhibited phosphorylation of Akt substrate-Girdin, and the secretion of matrix metalloproteinase (MMP), both of which were reported to be closely involved in migration and invasion. On the other hand, ZSTK474 inhibited the expression of HIF-1α and the secretion of vascular endothelial growth factor (VEGF), suggesting its potential antiangiogenic activity on PC3 cells. Moreover, we demonstrated the antiangiogenesis by determining the effect of ZSTK474-reduced VEGF on tube formation of human umbilical vein endothelial cells (HUVECs). In conclusion, ZSTK474 was demonstrated to have potential in vitro antimetastatic effects on PC3 cells via dual mechanisms: inhibition of metastatic processes including cell migration, invasion and adhesion, and antiangiogenesis via blockade of VEGF secretion.
Early Phenylpropanoid Biosynthetic Steps in Cannabis sativa: Link between Genes and Metabolites
Authors: Docimo Teresa , Consonni Roberto , Coraggio Immacolata , Mattana Monica
Published: June 2013

Phenylalanine ammonia-lyase (PAL), Cinnamic acid 4-hydroxylase (C4H) and 4-Coumarate: CoA ligase (4CL) catalyze the first three steps of the general phenylpropanoid pathway whereas chalcone synthase (CHS) catalyzes the first specific step towards flavonoids production. This class of specialized metabolites has a wide range of biological functions in plant development and defence and a broad spectrum of therapeutic activities for human health. In this study, we report the isolation of hemp PAL and 4CL cDNA and genomic clones. Through in silico analysis of their deduced amino acid sequences, more than an 80% identity with homologues genes of other plants was shown and phylogenetic relationships were highlighted. Quantitative expression analysis of the four above mentioned genes, PAL and 4CL enzymatic activities, lignin content and NMR metabolite fingerprinting in different Cannabis sativa tissues were evaluated. Furthermore, the use of different substrates to assay PAL and 4CL enzymatic activities indicated that different isoforms were active in different tissues. The diversity in secondary metabolites content observed in leaves (mainly flavonoids) and roots (mainly lignin) was discussed in relation to gene expression and enzymatic activities data.
Ectopic Overexpression of an AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) Gene OsIAA4 in Rice Induces Morphological Changes and Reduces Responsiveness to Auxin
Authors: Song Yaling , Xu Zeng-Fu
Published: June 2013

Auxin has pleiotropic effects on plant growth and development. AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) proteins are short-lived transcriptional regulators that mediate auxin responses through interaction with an auxin receptor, the F-box protein transport inhibitor response 1 (TIR1). Most functions of Aux/IAA proteins have been identified in Arabidopsis by studying the gain-of-function mutants in domain II. In this study, we isolated and identified an Aux/IAA protein gene from rice, OsIAA4, whose protein contains a dominant mutation-type domain II. OsIAA4 has very low expression in the entire life cycle of rice. OsIAA4-overexpressing rice plants show dwarfism, increased tiller angles, reduced gravity response, and are less sensitive to synthetic auxin 2,4-dichlorophenoxyacetic acid (2,4-D).
On the Distribution of the spt-Crank
Authors: Andrews George , Dyson Freeman , Rhoades Robert
Published: June 2013

Andrews, Garvan and Liang introduced the spt-crank for vector partitions. We conjecture that for any n the sequence { N S (m , n) } m is unimodal, where N S (m , n) is the number of S-partitions of size n with crank m weight by the spt-crank. We relate this conjecture to a distributional result concerning the usual rank and crank of unrestricted partitions. This leads to a heuristic that suggests the conjecture is true and allows us to asymptotically establish the conjecture. Additionally, we give an asymptotic study for the distribution of the spt-crank statistic. Finally, we give some speculations about a definition for the spt-crank in terms of “marked” partitions. A “marked” partition is an unrestricted integer partition where each part is marked with a multiplicity number. It remains an interesting and apparently challenging problem to interpret the spt-crank in terms of ordinary integer partitions.
Nepheliosyne B, a New Polyacetylenic Acid from the New Caledonian Marine Sponge Niphates sp.
Authors: Legrave Nathalie , Hamrouni-Buonomo Souhir , Dufies Maeva , Guérineau Vincent , Vacelet Jean , Auberger Patrick , Amade Philippe , Mehiri Mohamed
Published: June 2013

A new C47 polyoxygenated acetylenic acid, nepheliosyne B (2), along with the previously described nepheliosyne A (1), have been isolated from the New Caledonian marine sponge Niphates sp. Their structures have been elucidated on the basis of extensive spectroscopic analyses. These metabolites exhibited a moderate cytotoxicity against K562, U266, SKM1, and Kasumi cancer cell lines.
Facile and Efficient Syntheses of a Series of N-Benzyl and N-Biphenylmethyl Substituted Imidazole Derivatives Based on (E)-Urocanic acid, as Angiotensin II AT1 Receptor Blockers
Authors: Agelis George , Kelaidonis Konstantinos , Resvani Amalia , Kalavrizioti Dimitra , Androutsou Maria-Eleni , Plotas Panagiotis , Vlahakos Demetrios , Koukoulitsa Catherine , Tselios Theodore , Mavromoustakos Thomas , Matsoukas John
Published: June 2013

In the present work, a facile and efficient route for the synthesis of a series of N-substituted imidazole derivatives is described. Docking studies have revealed that N-substituted imidazole derivatives based on (E)-urocanic acid may be potential antihypertensive leads. Therefore, new AT1 receptor blockers bearing either the benzyl or the biphenylmethyl moiety at the N-1 or N-3 position, either the (E)-acrylate or the propanoate fragment and their related acids at the C-4 position as well as a halogen atom at the C-5 position of the imidazole ring, were synthesized. The newly synthesized analogues were evaluated for binding to human AT1 receptor. The biological results showed that this class of molecules possesses moderate or no activity, thus not always confirming high docking scores. Nonetheless, important conclusions can be derived for their molecular basis of their mode of action and help medicinal chemists to design and synthesize more potent ones. An aliphatic group as in losartan seems to be important for enhancing binding affinity and activity.
Synthesis, Surface Modification and Characterisation of Biocompatible Magnetic Iron Oxide Nanoparticles for Biomedical Applications
Authors: Mahdavi Mahnaz , Ahmad Mansor , Haron Md , Namvar Farideh , Nadi Behzad , Rahman Mohamad , Amin Jamileh
Published: June 2013

Superparamagnetic iron oxide nanoparticles (MNPs) with appropriate surface chemistry exhibit many interesting properties that can be exploited in a variety of biomedical applications such as magnetic resonance imaging contrast enhancement, tissue repair, hyperthermia, drug delivery and in cell separation. These applications required that the MNPs such as iron oxide Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) having high magnetization values and particle size smaller than 100 nm. This paper reports the experimental detail for preparation of monodisperse oleic acid (OA)-coated Fe3O4 MNPs by chemical co-precipitation method to determine the optimum pH, initial temperature and stirring speed in order to obtain the MNPs with small particle size and size distribution that is needed for biomedical applications. The obtained nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray fluorescence spectrometry (EDXRF), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), and vibrating sample magnetometer (VSM). The results show that the particle size as well as the magnetization of the MNPs was very much dependent on pH, initial temperature of Fe2+ and Fe3+ solutions and steering speed. The monodisperse Fe3O4 MNPs coated with oleic acid with size of 7.8 ± 1.9 nm were successfully prepared at optimum pH 11, initial temperature of 45 °C and at stirring rate of 800 rpm. FTIR and XRD data reveal that the oleic acid molecules were adsorbed on the magnetic nanoparticles by chemisorption. Analyses of TEM show the oleic acid provided the Fe3O4 particles with better dispersibility. The synthesized Fe3O4 nanoparticles exhibited superparamagnetic behavior and the saturation magnetization of the Fe3O4 nanoparticles increased with the particle size.
New 7-[4-(4-(un)Substituted)piperazine-1-carbonyl]- piperazin-1-yl] Derivatives of Fluoroquinolone: Synthesis and Antimicrobial Evaluation
Authors: Chen Po-Ting , Lin Wen-Po , Lee An-Rong , Hu Ming-Kuan
Published: June 2013

Fluoroquinolones have been a class of important synthetic antimicrobial agents broadly and effectively used in clinic for infectious diseases. In this study, the synthesis of a range of fluoroquinolone derivatives with 4-(carbopiperazin-1-yl)piperazinyl moieties at the C7 position and their inhibition of bacterial pathogens commonly disseminated in hospital environment were described. The results indicated that a 7-[4-(4-(benzoyl)carbopiperazin-1-yl)]piperazinyl derivative 5h and two 7-[4-(4- (benzenesulfonyl)carbopiperazin-1-yl)]piperazinyl derivatives 5k and 5l showed more promising growth inhibition of ciprofloxacin-resistant P. aeruginosa (CRPA) with MIC values as low as 16 mg/mL which is 16-fold more potent than ciprofloxacin, while most of other derivatives maintained potency against methicillin-resistant Staphylococcus aureus (MRSA).
ADVICE: A New Approach for Near-Real-Time Monitoring of Surface Displacements in Landslide Hazard Scenarios
Authors: Allasia Paolo , Manconi Andrea , Giordan Daniele , Baldo Marco , Lollino Giorgio
Published: June 2013

We present a new method for near-real-time monitoring of surface displacements due to landslide phenomena, namely ADVanced dIsplaCement monitoring system for Early warning (ADVICE). The procedure includes: (i) data acquisition and transfer protocols; (ii) data collection, filtering, and validation; (iii) data analysis and restitution through a set of dedicated software; (iv) recognition of displacement/velocity threshold, early warning messages via SMS and/or emails; (v) automatic publication of the results on a dedicated webpage. We show how the system evolved and the results obtained by applying ADVICE over three years into a real early warning scenario relevant to a large earthflow located in southern Italy. ADVICE has speed-up and facilitated the understanding of the landslide phenomenon, the communication of the monitoring results to the partners, and consequently the decision-making process in a critical scenario. Our work might have potential applications not only for landslide monitoring but also in other contexts, as monitoring of other geohazards and of complex infrastructures, as open-pit mines, buildings, dams, etc.
From Transit Migrants to Trading Migrants: Development Opportunities for Nigerians in the Transnational Trade Sector of Istanbul
Authors: Schapendonk Joris
Published: June 2013

This paper critically discusses the relation between human mobility and development. It moves away from conventional migration-development policy discussions that mainly focus on diaspora-like actors, who have established a stable and integrated socio-economic position in the destination countries. Instead, it looks at mobility-development dynamics in the context of less privileged and less integrated migrants; Nigerian migrants who are (or have been) living in transit-like situations in the city of Istanbul (Turkey). Based on in-depth interviews with Nigerian migrants, it analyses migrants’ personal developments in the light of their migration trajectories. The analysis particularly shows how upward social mobility is not so much found in onward migration to Europe, but in getting involved in a different form of mobility; informally arranged transnational trade between Turkey and West Africa. It outlines the diverse roles of migrants in this informal trade sector and elaborates on their relations with fly in/fly out traders originating from Africa. With these empirical insights, I conclude that these migrants do not belong to settled diaspora communities, but nevertheless, act as bridges between “here” and “there” and contribute to the creation of (new) development corridors.