bluuebunny/crossref_metadata_2025 huggingface dataset:
Ceramics in Rolling Element Bearings
Authors: Bersch C. F. , Weinberg Philip
Published: April 2015

The feasibility of using hot-pressed silicon nitride (HPSN) for rolling elements and for races in ball bearings and roller bearings has been explored. HPSN offers opportunities to alleviate many current bearing problems including DN and fatigue life limitations, lubricant and cooling system deficiencies, and extreme environment demands. The history of ceramic bearings and the results of various element tests, bearing tests in rigs, and bearing tests in a turbine engine will be reviewed. The advantages and problems associated with the use of HPSN in rolling element bearings will be discussed.
First Experimental Results on a Silicon-Nitride Recuperator With Six Heat Exchanger Elements
Authors: Forster S. , Jaegers H. , Kleemann M.
Published: April 2015

A prototype ceramic recuperator consisting of six heat exchanger elements of Si3N4, being arranged side by side in a self-sealing and self-supporting configuration, was investigated experimentally with respect to the heat transfer-, friction- and mechanical-properties as well as to the sealing performance. The heat exchanger elements are developed in collaboration by Kernforschungsanlage Jülich GmbH (KFA) and Rosenthal Technik AG (RTAG). The recuperator arrangement corresponds well to an unique design principle for small automotive “ceramic” gas turbines. The thermodynamic measurements were carried out with air, electrically heated up to temperatures of about 100 C, and at pressures on the HP-side up to about 2 bar. The self-sealing and self-supporting heat exchanger arrangement promises to be satisfying for vehicular application purposes. Partial rupture of heat exchanger walls in the prototype-elements began at a pressure difference of about 3 bar. On the basis of the experimental results, a design of a vehicular gas turbine for 70-Kw shaft power and with heat exchanger elements for advanced fabrication technique is presented. A planned test facility for gas temperatures up to about 1200 C and with a new set of heat exchanger elements from Si3N4 or SiC is described briefly.
Water-Cooled Gas Turbine Development Program Wheelbox Tests
Authors: Piekarski A. J. , Gibbs R. , Zeman K. P.
Published: April 2015

The incentives for a water-cooled gas turbine have been previously presented by Caruvana et al.1 The ongoing water cooling development effort at General Electric, including the successful operation of a 9.7 in. (24.7 cm) dia laboratory turbine at firing temperatures up to 3500 F (1927 C), has been described by Horner et al.2 An important portion of this effort is wheelbox testing wherein water transfer, distribution, cooling, collection, and erosion are being studied in full-scale rotating hardware of the General Electric MS-7000 size gas turbine. In addition, rotor dynamic and bucket tip water discharge characteristics are being obtained for the design of a full size water-cooled gas turbine. Discussed are the design of the rather unique test vehicle and the results obtained from the initial test phase. Results from the second phase of testing, to be conducted in late 1978, will be the subject of a future paper. This effort has been funded under the EPRI Water-Cooled Gas Turbine Development Project.
Iterative Development of Injection Molded Sintered Alpha SiC Turbine Material
Authors: Smoak R. H. , Storm R. S.
Published: April 2015

A closed-loop iterative development method was used to improve the properties of injection molded turbine material. Both non-destructive and destructive evaluation were applied at each step in the process route to provide feedback into the development cycle. Flexural strength and strength distribution of test coupons were used as a response to the effect of changes in process variables. Extensive failure analysis was performed in order to determine the size and type of defect at the origin of failure. Several repetitions of this closed-loop development approach and the resultant improvement in properties are described.
Unique Aspects of Terrestrial Photovoltaic System Design
Authors: Putney Z. C.
Published: April 2015

The design of terrestrial photovoltaic power systems involves a process of optimization of elements quite different from that employed in conventional power sources. Solar input varies locally and temporally. Efficiency of conversion to electricity is highly dependent upon collector concentration ratio, orientation and tracking capability, and optical and solar cell technologies employed; other variations occur with temperature and changes in reflective and transmissive properties of components. Reliability is dependent upon system complexity and hardware selected. Energy storage needs are a dual function of the fluctuating solar input and load profile, with a substantial range of photovoltaic array size/storage tradeoffs available in designing a stand-alone system. Key aspects to be considered in the design of a photovoltaic power system are discussed in this paper, with a specific application treated in detail as an example of their implementation.
Design Considerations of Small Solar Collector Systems Using Plane Heliostats
Authors: Waldron K. J. , Kheyrandish Kambiz , Meyers A. C.
Published: April 2015

The primary advantage of the central receiver concept is the minimization of heat transmission in the form of enthalpy of a working fluid. This is replaced by efficient and low cost optical energy transmission. This characteristic renders collectors using heliostats to reflect solar radiation onto a stationary receiver attractive for small to medium scale, as well as large scale collection. This paper describes several years of design studies and simulations of central receiver systems scaled to be suitable for heating and cooling of commercial buildings or for some industrial process heat applications. The relatively small distances between the heliostats and receiver, vertical flat plate receiver geometry, and relatively low receiver result in optical simulation characteristics of such systems quite different to those of the large solar tower systems. The variation in radiation intensity over the surface of the receiver due to the relatively irregular shape of the insolated patch from a heliostat segment, and due to dispersion produced by off axis aberration in segmented heliostats, requires several unique features in the receiver design.
The Solar Potential for Process Heat: A Commercialization Perspective
Authors: Barbieri R. H.
Published: April 2015

A overview of the results of a survey of potential applications of solar energy for supplying process heat requirements in the industrial sector of California is presented. Technical, economic, and institutional characteristics of the sector are examined. Specific applications for solar energy are then discussed. Finally, implications for state and federal energy policy are discussed along with a perspective on the potential for commercialization of solar industrial process heat systems.
Prospects for Farming the Open Ocean
Authors: Wilcox H. A.
Published: April 2015

Presently, visualized prospects for farming the open oceans of the earth are based mainly on results obtained by the Navy’s Ocean Food and Energy Farm Project. This Project was sponsored by several Federal agencies and private industry, and its results indicated that a system of giant oceanic farms would be capable of producing foods, liquid and gaseous fuels, lubricants, fertilizers, industrial chemicals, and plastics at rates sufficient to supply all the related requirements of one average U.S. citizen for each 2 to 3 acres of cultivated ocean (one acre = 0.4047 hectare = 4047 sq m). Synthetic natural gas from the system was projected to cost from about $2 up to about $7 per million Btu, depending mainly on credit values assumed for foods and other products (all dollar values expressed in constant 1974 dollars; 1 Btu = one British thermal unit = 252 calories = 1/3413th kwh). Although Navy participation in the Project has now been terminated, the Project is proceeding under management of the General Electric Co. with financial sponsorship being furnished by the American Gas Industry and the U.S. Department of Energy.
Photovoltaic Concentrator System Technology and Applications Experiments
Authors: Burgess E. L.
Published: April 2015

Photovoltaic systems offer the potential of providing a significant portion of the nation’s electrical energy needs by converting solar energy directly into electrical energy. The major obstacle preventing this potential from being realized is the cost of photovoltaic systems. One approach to reducing system cost is to concentrate sunlight on the photovoltaic cells, increasing their output and, hence, decreasing the amount of cell area required for a given power output. This concept essentially trades high cost cell area for lower cost concentrating optics area. Photovoltaic concentrator technology is still in the development stages but has made considerable progress and gained significant attention during the past few years. This technology is described and its future potential is discussed. In addition, brief summaries of several concentrator applications experiments which are in the system design phase are presented. The purpose of these experiments are to provide on-site experience with photovoltaic concentrator systems.
On the effect of serum on the transport of reactive oxygen species across phospholipid membranes
Authors: Szili Endre J. , Hong Sung-Ha , Short Robert D.
Published: April 2015

The transport of plasma generated reactive oxygen species (ROS) across a simple phospholipid membrane mimic of a (real) cell was investigated. Experiments were performed in cell culture media (Dulbecco's modified Eagle's medium, DMEM), with and without 10% serum. A (broad spectrum) ROS reporter dye, 2,7-dichlorodihydrofluorescein (DCFH), was used to detect the generation of ROS by a helium (He) plasma jet in DMEM using free DCFH and with DCFH encapsulated inside phospholipid membrane vesicles dispersed in DMEM. The authors focus on the concentration and on the relative rates (arbitrary units) for oxidation of DCFH [or the appearance of the oxidized product 2,7-dichlorofluorescein (DCF)] both in solution and within vesicles. In the first 1 h following plasma exposure, the concentration of free DCF in DMEM was ∼15× greater in the presence of serum (cf. to the serum-free DMEM control). The DCF in vesicles was ∼2× greater in DMEM containing serum compared to the serum-free DMEM control. These data show that serum enhances plasma ROS generation in DMEM. As expected, the role of the phospholipid membrane was to reduce the rate of oxidation of the encapsulated DCFH (with and without serum). And the efficiency of ROS transport into vesicles was lower in DMEM containing serum (at 4% efficiency) when compared to serum-free DMEM (at 32% efficiency). After 1 h, the rate of DCFH oxidation was found to have significantly reduced. Based upon a synthesis of these data with results from the open literature, the authors speculate on how the components of biological fluid and cellular membranes might affect the kinetics of consumption of plasma generated ROS.
The makers of the Protoaurignacian and implications for Neandertal extinction
Authors: Benazzi S. , Slon V. , Talamo S. , Negrino F. , Peresani M. , Bailey S. E. , Sawyer S. , Panetta D. , Vicino G. , Starnini E. , Mannino M. A. , Salvadori P. A. , Meyer M. , Pääbo S. , Hublin J.-J.
Published: April 2015

Cultural prehistory in southern Europe

The Protoaurignacian culture appeared in the southern European archeological record around 42,000 years ago and was characterized by artefacts including personal ornaments and bladelets. Archaeologists have debated whether it was ancestral
Homo sapiens
or Neandertals who made these tools and ornaments. Benazzi
et al.
analyzed dental remains from two Protoaurignacian sites in Italy and confirm that they were
H. sapiens
. The arrival of this culture may have led to the demise of Neandertals in these areas (see the Perspective by Conard
et al.
).

Science
, this issue p.
793
; see also p.
754
Microtubule detyrosination guides chromosomes during mitosis
Authors: Barisic Marin , Silva e Sousa Ricardo , Tripathy Suvranta K. , Magiera Maria M. , Zaytsev Anatoly V. , Pereira Ana L. , Janke Carsten , Grishchuk Ekaterina L. , Maiato Helder
Published: April 2015

Chromosomes: Let me be your guide

The correct alignment of chromosomes at the center of the mitotic spindle—the metaphase plate—before cell division is one of the key mechanisms for the maintenance of genomic stability. But is there anything special about the microtubules of the spindle that helps this process? Barisic
et al.
demonstrate that chromosome alignment at the cell equator is controlled by a specific posttranslational modification of selected microtubules oriented toward the center of the mitotic spindle.

Science
, this issue p.
799
Draft Genome Sequence of
Clostridium
sp. Ne2, Clostridia from an Enrichment Culture Obtained from Australian Subterranean Termite,
Nasutitermes exitiosus
Authors: Wang Han , Lin Hai , Tran-Dinh Nai , Li Dongmei , Greenfield Paul , Midgley David J.
Published: April 2015

The draft genome sequence of
Clostridium
sp. Ne2 was reconstructed from a metagenome of a hydrogenogenic microbial consortium. The organism is most closely related to
Clostridium magnum
and is a strict anaerobe that is predicted to ferment a range of simple sugars.
Draft Genome Sequence of
Pseudoalteromonas
sp. Strain ECSMB14103, Isolated from the East China Sea
Authors: Guo Xing-Pan , Ding De-Wen , Bao Wei-Yang , Yang Jin-Long
Published: April 2015

Pseudoalteromonas
sp. strain ECSMB14103 was isolated from marine biofilms formed on the East China Sea. The draft genome sequence comprises 4.11 Mp with a G+C content of 39.7%. The information from the draft genome will contribute to an understanding of bacteria-animal interaction.
Complete Genome Sequencing of Protease-Producing Novel
Arthrobacter
sp. Strain IHBB 11108 Using PacBio Single-Molecule Real-Time Sequencing Technology
Authors: Kiran Shashi , Swarnkar Mohit K. , Pal Mohinder , Thakur Rishu , Tewari Rupinder , Singh Anil Kumar , Gulati Arvind
Published: April 2015

A previously uncharacterized species of the genus
Arthrobacter
, strain IHBB 11108 (MCC 2780), is a Gram-positive, strictly aerobic, nonmotile, cold-adapted, and protease-producing alkaliphilic actinobacterium, isolated from shallow undersurface water from Chandra Tal Lake, Lahaul-Spiti, India. The complete genome of the strain is 3.6 Mb in size with an average 58.97% G+C content.
Complete Genome Sequence of Fish Pathogen Aeromonas hydrophila AL06-06
Authors: Tekedar Hasan C. , Karsi Attila , Akgul Ali , Kalindamar Safak , Waldbieser Geoffrey C. , Sonstegard Tad , Schroeder Steven G. , Lawrence Mark L.
Published: April 2015

Aeromonas hydrophila
occurs in freshwater environments and infects fish and mammals. Here, we report the complete genome sequence of
Aeromonas hydrophila
AL06-06, which was isolated from diseased goldfish and is being used for comparative genomic studies with
A. hydrophila
strains that cause bacterial septicemia in channel catfish aquaculture.
Draft Genome Sequence of a Novel Culturable Marine Chroococcalean Cyanobacterium from the South Atlantic Ocean
Authors: Rigonato Janaina , Alvarenga Danillo O. , Branco Luis H. Z. , Varani Alessandro M. , Brandini Frederico P. , Fiore Marli F.
Published: April 2015

The novel chroococcalean cyanobacterium strain CENA595 was isolated from the deep chlorophyll maximum layer of the continental shelf of the South Atlantic Ocean. Here, we report the draft genome sequence for this strain, consisting of 60 contigs containing a total of 5,265,703 bp and 3,276 putative protein-coding genes.
Intra-operative acidosis during 5-aminolevulinic acid assisted glioma resection
Authors: Anderson Ian , Naylor Thomas , McKinlay Justin , Sivakumar Gnanamurthy
Published: April 2015

A 47-year-old man underwent 5-aminolevulinic acid assisted resection of high grade glioma. Intraoperatively, he developed a compensated lactic acidosis that was managed medically and did not cause long term complications.
A chest wall pulsating mass
Authors: Patrício Catarina , Ribeiro Rita , Malheiro Rui , Silva Filipa Pais da
Published: April 2015

A 34-year-old HIV-positive man with intravenous drug addiction presented with a 2-week history of fever and a pulsatile presternal mass; 2 weeks prior he had suffered a traumatic sternal fracture. The CT scan showed a bulky abscess with presternal and retrosternal extension that contacted the heart (which explained its pulsatile effect) and pulmonary necrotising lesions. Drainage of the thoracic wall abscess was performed, and antibiotics (flucloxacillin plus gentamicin) were started on the presumption of staphylococcal bacteraemia given the patient's intravenous drug habit. Blood cultures and culture of the aspirated pus confirmed growth of methicillin-sensitiveStaphylococcus aureus; transoesophageal echocardiography showed endocarditis of the tricuspid valve. We therefore assumed pulmonary septic embolisation from right-sided endocarditis and acute sternal osteomyelitis, and the patient was treated for 6 weeks with clinical resolution.
Syndrome of inappropriate antidiuretic hormone secretion: a story of duloxetine-induced hyponatraemia
Authors: Amoako Adae Opoku , Brown Carina , Riley Timothy
Published: April 2015

Hyponatraemia is the most commonly encountered electrolyte abnormality in clinical practice. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) accounts for nearly 60% of all hyponatraemias. Selective serotonin reuptake inhibitors (SSRIs) are well known to have side effects of SIADH. There have been few reported cases of serotonin norepinephrine reuptake inhibitors (SNRIs) causing SIADH-induced hyponatraemia. Duloxetine is one type of SNRI used to treat several conditions, including depression and diabetic neuropathy. We present a case of a 76-year-old woman with a history of fibromyalgia who had recently been prescribed duloxetine for her condition. On admission to the hospital, her sodium decreased to a low of 118 mmol/L. Evaluation for other causes of hyponatraemia yielded negative results. Duloxetine was discontinued and after 3 days the patient's sodium increased to 130 mmol/L. The purpose of this case report is to highlight the importance of having suspicion for rare but real side effects of medications such as duloxetine.
Metastatic basal cell carcinoma: a frequent disease with rare clinical evolution
Authors: Carvalho Carolina Teixeira , Pinto Marta Mesquita , Plácido Ana Neto , Martins Ana
Published: April 2015

Basal cell carcinoma (BCC) is the most common malignancy worldwide. BCC has a benign evaluation, despite the high rate of local recurrence. Conversely, metastatic BCC (mBCC) is extremely rare. In this article, we present a case of an 86-year-old woman with a history of forearm mBCC, excised in 2009. In 2011, she experienced a left axilla enlargement and the evaluation revealed metastasis of mBCC. The patient began chemotherapy but had regional progression. After she had undergone radiotherapy, initiation of a clinical phase II trial was proposed, which she refused. The patient died in March 2013, 17 months after metastases diagnosis. mBCC poses a significant management challenge and current treatment options are limited. The gold standard treatment is surgical excision. Given the rarity of metastatic spread of cancer and the limited effectiveness of cytostatic agents, it has been a challenge to treat these types of patients.
Renal infarction caused by medium vessel vasculitis
Authors: Kavarthapol Jayaraman Vinothkumar , Chakera Aron
Published: April 2015

A 44-year-old Italian man presented to the emergency department on three occasions over 4 days with severe left flank pain. Initial investigations including a renal tract ultrasound were normal and he was discharged with analgaesia. On his third presentation, a CT angiogram was performed due to persisting pain, which demonstrated infarction of his left kidney as well as thickening of the anterior branch of left renal artery and complete occlusion with focal intimal dissection of the coeliac artery. His antineutrophil cytoplasmic antibody was negative. A medium vessel vasculitis was suspected and confirmed on positron emission tomography-CT, which revealed increased metabolic activity involving the right internal mammary artery and coeliac artery. Treatment with pulse methylprednisolone was started followed by a tapering prednisolone regimen, with a rapid reduction in his inflammatory indices. Twenty-four months later his renal function remains normal off all immunosuppression.
Three distinct mechanisms predominate in non-contact anterior cruciate ligament injuries in male professional football players: a systematic video analysis of 39 cases
Authors: Waldén Markus , Krosshaug Tron , Bjørneboe John , Andersen Thor Einar , Faul Oliver , Hägglund Martin
Published: April 2015

Background

Current knowledge on anterior cruciate ligament (ACL) injury mechanisms in male football players is limited.

Aim

To describe ACL injury mechanisms in male professional football players using systematic video analysis.

Methods

We assessed videos from 39 complete ACL tears recorded via prospective professional football injury surveillance between 2001 and 2011. Five analysts independently reviewed all videos to estimate the time of initial foot contact with the ground and the time of ACL tear. We then analysed all videos according to a structured format describing the injury circumstances and lower limb joint biomechanics.

Results

Twenty-five injuries were non-contact, eight indirect contact and six direct contact injuries. We identified three main categories of non-contact and indirect contact injury situations: (1) pressing (n=11), (2) re-gaining balance after kicking (n=5) and (3) landing after heading (n=5). The fourth main injury situation was direct contact with the injured leg or knee (n=6). Knee valgus was frequently seen in the main categories of non-contact and indirect contact playing situations (n=11), but a dynamic valgus collapse was infrequent (n=3). This was in contrast to the tackling-induced direct contact situations where a knee valgus collapse occurred in all cases (n=3).

Conclusions

Eighty-five per cent of the ACL injuries in male professional football players resulted from non-contact or indirect contact mechanisms. The most common playing situation leading to injury was pressing followed by kicking and heading. Knee valgus was frequently seen regardless of the playing situation, but a dynamic valgus collapse was rare.
Violence against Congolese refugee women in Rwanda and mental health: a cross-sectional study using latent class analysis
Authors: Sipsma Heather L , Falb Kathryn L , Willie Tiara , Bradley Elizabeth H , Bienkowski Lauren , Meerdink Ned , Gupta Jhumka
Published: April 2015

Objective

To examine patterns of conflict-related violence and intimate partner violence (IPV) and their associations with emotional distress among Congolese refugee women living in Rwanda.

Design

Cross-sectional study.

Setting

Two Congolese refugee camps in Rwanda.

Participants

548 ever-married Congolese refugee women of reproductive age (15–49 years) residing in Rwanda.

Primary outcome measure

Our primary outcome was emotional distress as measured using the Self-Report Questionnaire-20 (SRQ-20). For analysis, we considered participants with scores greater than 10 to be experiencing emotional distress and participants with scores of 10 or less not to be experiencing emotional distress.

Results

Almost half of women (49%) reported experiencing physical, emotional or sexual violence during the conflict, and less than 10% of women reported experiencing of any type of violence after fleeing the conflict. Lifetime IPV was reported by approximately 22% of women. Latent class analysis derived four distinct classes of violence experiences, including theLow All Violenceclass, theHigh Violence During Conflictclass, theHigh IPVclass and theHigh Violence During and After Conflictclass. In multivariate regression models, latent class was strongly associated with emotional distress. Compared with women in theLow All Violenceclass, women in theHigh Violence During and After Conflictclass and women in theHigh Violence During Conflicthad 2.7 times (95% CI 1.11 to 6.74) and 2.3 times (95% CI 1.30 to 4.07) the odds of experiencing emotional distress in the past 4 weeks, respectively. Furthermore, women in theHigh IPVclass had a 4.7 times (95% CI 2.53 to 8.59) greater odds of experiencing emotional distress compared with women in theLow All Violenceclass.

Conclusions

Experiences of IPV do not consistently correlate with experiences of conflict-related violence, and women who experience high levels of IPV may have the greatest likelihood for poor mental health in conflict-affected settings.
Systematic review of the effects of iodised salt and iodine supplements on prenatal and postnatal growth: study protocol
Authors: Farebrother Jessica , Naude Celeste E , Nicol Liesl , Sang Zhongna , Yang Zhenyu , Andersson Maria , Jooste Pieter L , Zimmermann Michael B
Published: April 2015

Introduction

Iodine is an essential micronutrient and component of the thyroid hormones. Sufficient ingestion of iodine is necessary for normal growth and development. If iodine requirements are not met, growth can be impaired. Salt iodisation and supplementation with iodine can prevent iodine deficiency disorders and stunted growth. No systematic review has yet collated the evidence linking iodine to growth. With an increased emphasis on stunting within the WHO Global Nutrition Targets for 2025, we propose a systematic review to address this question.

Methods and analysis

We will undertake a systematic review, and if appropriate, meta-analyses, evaluating the effects of iodised salt or iodine supplements on prenatal and postnatal somatic growth, until age 18. We will search a number of databases, including MEDLINE, EMBASE, Web of Science, CINAHL, PsychINFO, the Cochrane Library, including the CENTRAL register of Controlled Trials and also the WHO library and ICTRP (International Clinical Trials Registry Platform), which includes the Clinicaltrials.gov repository. We will also search Wanfang Data and the China Knowledge Resource Integrated Database. Included studies must have compared exposure to iodised salt, iodine supplements or iodised oil, to placebo, non-iodised salt or no intervention. Primary outcomes will be continuous and categorical markers of prenatal and postnatal somatic growth. Secondary outcomes will cover further measures of growth, including growth rates and indirect markers of growth such as insulin-like growth factor-1 (IGF-1).

Ethics and dissemination

The systematic review will be published in a peer-reviewed journal, and will be sent directly to the WHO, United Nations Children's Fund, International Council for the Control of Iodine Deficiency Disorders and other stakeholders. The results generated from this systematic review will provide evidence to support future programme recommendations regarding iodine fortification or supplementation and child growth.

Trial registration number

PROSPERO CRD42014012940.
Quantum propagator and characteristic equation in the presence of a chain of δ-potentials
Authors: Refaei A. , Kheirandish F.
Published: April 2015

The quantum propagator and characteristic equation in the presence of a chain of δ-potentials are obtained in the rectangular, cylindrical and spherical coordinate systems. The simplicity and efficiency of the method is illustrated via examples. As an application, the characteristic equation of a quantum harmonic oscillator confined to an infinite box is obtained. The roots of the characteristic equation, determining the energy eigenvalues of the restricted oscillator, are calculated approximately and compared with the existing numerical data. Due to the similarity between Schrödinger and diffusion equations, the problem can be considered as exact solutions of the diffusion equation in the presence of a chain of δ-potentials as boundary.
HEMODYNAMIC COMPARISON BETWEEN NORMAL GRAFT AND Y-TYPE GRAFT IN CORONARY ARTERY BYPASS GRAFTING: A NUMERICAL STUDY USING 0D/3D COUPLING METHOD
Authors: ZHAO XI , LIU YOUJUN , MA LIANCAI , WANG WENXIN , XIE JINSHENG , QIAO AIKE
Published: April 2015

Different surgical procedures in coronary artery bypass grafting (CABG) will cause different hemodynamic environments, which will affect the surgical result and long-term patency. In this study, the hemodynamic effect of the Y-type graft was discussed by comparing it with normal graft. A patient-specific 3-dimensional (3D) model of coronary artery with serious stenosis was reconstructed. Two different surgical procedures were applied on the 3D model through the virtual surgery, the normal graft and the Y-type graft. Thus, two 3D models with different grafts were built. The zero-dimensional (0D)/3D coupling method was used to perform the numerical simulation by coupling the 3D artery model with a 0D lumped parameter model of the cardiovascular system. The coronary flow rate and the graft flow were calculated and illustrated in this paper. The wall shear stress (WSS) and oscillatory shear index (OSI) were also calculated and depicted. The short-term outcomes of the normal graft and Y-type graft are almost the same. But the long-term patency of the Y-type graft is worse. Moreover, decreasing the diameter of the graft to LCX may get higher WSS and provide enough flow at the same time.
THE MANDIBLE REMODELING INDUCED BY DENTAL IMPLANTS: A MESHLESS APPROACH
Authors: BELINHA J. , DINIS L. M. J. S. , JORGE R. M. NATAL
Published: April 2015

This work aims to evaluate the prediction efficiency of a recently developed numerical approach in the mandible bone tissue remodeling process. The remodeling algorithm, seeking the minimization of the strain energy density, includes a phenomenological anisotropic material law capable of predicting the bone tissue mechanical properties based on the bone apparent density. The key factor of the proposed numerical approach is the inclusion of a flexible and efficient meshless method, which is used to obtain the strain energy density field. The inclusion of this advance discretization technique in the process is an asset since meshless methods produce smoother and more accurate strain energy density fields when compared with other numerical approaches. The bone tissue remodeling process of the molar region of the mandible, due to the inclusion of an implant system, is studied. The obtained results are in accordance with other numerical approach results available in the literature.
ELECTROLOC: A SIMPLE, FAST AND ACCURATE SYSTEM FOR LOCALIZATION OF ENDOCARDIAL CATHETERS
Authors: MARCELLI E. , PIRANI S. , CORAZZA I. , CERCENELLI L.
Published: April 2015

Accurate positioning of endocardial catheters inside cardiovascular structures is crucial in electrophysiology (EP) procedures. Improvements in cardiac mapping are required for a better understanding and treatment of arrhythmias. The proposed Electroloc system is a simple, fast and accurate method for endocardial catheters localization. The key features of Electroloc are the use of conventional EP catheters and the simple data processing for providing localization. Electroloc is able to locate any conventional EP mapping catheter with respect to a noncontact EP catheter used as reference, by sequentially passing a sub-threshold current between the mapping electrode (ME) of the mapping catheter and each electrode of the reference catheter. This creates different potential gradients across the reference catheter used to compute two spatial coordinates (horizontal and vertical coordinates) intended for positioning the ME in the cardiac chamber. In vitro experiments demonstrated that Electroloc is a reliable and sensitive system for localizing the ME with a spatial resolution of 2 mm in the vertical localization and of 5 mm in the horizontal localization. Further studies will be required to improve Electroloc accuracy and to extend its sensitivity range.
IDENTIFYING IMPORTANT CLASSES OF LARGE SOFTWARE SYSTEMS THROUGH K-CORE DECOMPOSITION
Authors: MEYER P. , SIY H. , BHOWMICK S.
Published: April 2015

In a large software project, the number of classes, and the dependencies between them, generally increase as software evolves. The size and scale of the system often makes it difficult to easily identify the important components in a particular software product. To address this problem, we model software as a network, where the classes are the vertices in the network and the dependencies are the edges, and apply K-core decomposition to identify a core subset of vertices as potentially important classes. We study three open source Java projects over a 10-year period and demonstrate, using different metrics, that the K-core decomposition of the network can help us identify the key classes of the corresponding software. Specifically, we show that the vertices with the highest core number represent the important classes and demonstrate that the core-numbers of classes with similar functionalities evolve at similar trends.
Quantum blind signature with an offline repository
Authors: Ribeiro J. , Souto A. , Mateus P.
Published: April 2015

We propose a quantum blind signature scheme that achieves perfect security under the assumption of an honest offline repository. The security of the protocol also relies on perfect private quantum channels, which are achievable using quantum one-time pads with keys shared via a quantum key distribution (QKD) protocol. The proposed approach ensures that signatures cannot be copied and that the sender must compromise to a single message, which are important advantages over classical protocols for certain applications.
Effects of Sorafenib Dose on Acquired Reversible Resistance and Toxicity in Hepatocellular Carcinoma
Authors: Kuczynski Elizabeth A. , Lee Christina R. , Man Shan , Chen Eric , Kerbel Robert S.
Published: April 2015

Acquired evasive resistance is a major limitation of hepatocellular carcinoma (HCC) treatment with the tyrosine kinase inhibitor (TKI) sorafenib. Recent findings suggest that resistance to sorafenib may have a reversible phenotype. In addition, loss of responsiveness has been proposed to be due to a gradual decrease in sorafenib plasma levels in patients. Here, the possible mechanisms underlying reversible sorafenib resistance were investigated using a Hep3B-hCG orthotopic human xenograft model of locally advanced HCC. Tissue and plasma sorafenib and metabolite levels, downstream antitumor targets, and toxicity were assessed during standard and dose-escalated sorafenib treatment. Drug levels were found to decline significantly over time in mice treated with 30 mg/kg sorafenib, coinciding with the onset of resistance but a greater magnitude of change was observed in tissues compared with plasma. Skin rash also correlated with drug levels and tended to decrease in severity over time. Drug level changes appeared to be partially tumor dependent involving induction of tumoral CYP3A4 metabolism, with host pretreatment alone unable to generate resistance. Escalation from 30 to 60 mg/kg sorafenib improved antitumor efficacy but worsened survival due to excessive body weight loss. Microvessel density was inhibited by sorafenib treatment but remained suppressed over time and dose increase. In conclusion, tumor CYP3A4 induction by sorafenib is a novel mechanism to account for variability in systemic drug levels; however, declining systemic sorafenib levels may only be a minor resistance mechanism. Escalating the dose may be an effective treatment strategy, provided toxicity can be controlled. Cancer Res; 75(12); 2510–9. ©2015 AACR.
Intravenous Transplantation of BMP2-Transduced Endothelial Progenitor Cells Attenuates Lipopolysaccharide-Induced Acute Lung Injury in Rats
Authors: Yin Xiuru , Liang Zuodi , Yun Yue , Pei Ling
Published: April 2015

Background/Aims: Acute lung injury (ALI) and its aggressive stage, acute respiratory distress syndrome (ARDS), are characterized by diffuse damage and increased permeability of the endothelial barrier, leading to alveolar infiltrates and interstitial edema. Enhancing endothelial integrity represents a novel therapeutic strategy for ALI/ARDS. Endothelial progenitor cells (EPCs) have been reported to participate in endothelial repair of ALI and also serve as a tool for gene therapy. Further, bone morphogenetic protein 2 (BMP2) is an essential signaling molecule that regulates the fate of different cell types. The aim of our study is to explore whether bone marrow-derived EPCs transduced with lentiviral-mediated BMP2 gene might benefit lipopolysaccharide (LPS)-induced ALI in a rat model. Methods: Rats were divided randomly into five groups. The sham group was given normal saline via the trachea and right jugular vein. The other four groups underwent intratracheal-LPS-induced ALI followed after 30 min by treatment with either normal saline, EPCs, EPCs transduced with empty lentiviral vector (EPCs-null), or EPCs transduced with BMP2 (EPCs-BMP2) via the right jugular vein. Results: We found that the lung injury score, oxygenation, and inflammatory response were significantly ameliorated in the three EPC-treated groups (EPCs, EPCs-null, and EPCs-BMP2). In addition, EPCs-BMP2 further improved endothelium repair and capillary permeability, causing markedly reduced wet-to-dry lung-weight ratio and BALF protein content, and increased levels of BMP2 protein, BMP2 mRNA, and eNOS protein in lung tissues. Conclusion: Transplantation of BMP2-transduced EPCs effectively attenuates edema and protein exudation compared with EPCs alone in LPS-induced ALI via enhanced expression of BMP2 and eNOS.
Nicorandil Protects the Heart from Ischemia/Reperfusion Injury by Attenuating Endoplasmic Reticulum Response-induced Apoptosis Through PI3K/Akt Signaling Pathway
Authors: Wu Hui , Ye Ming , Yang Jun , Ding Jiawang , Yang Jian , Dong Wusong , Wang Xinan
Published: April 2015

Background/Aims: As a vasodilatory drug used to treat angina, nicorandil has been shown to induce an infarct-limiting effect in various experimental animal models of myocardial ischemia-reperfusion (IR). There are multiple mechanisms causing the IR injury, among which, the endoplasmic reticulum (ER) stress and ER stress-initiated apoptosis are implicated to play an important role. However, whether ER stress is involved in nicorandil-induced cardioprotection is unknown. Methods: Post-ischemic functional recovery, lactate dehydrogenase (LDH) release and infarct size in perfused rat hearts subjected to global no-flow I/R were measured to analysis the effect of nicorandil and ER stress inducer of tunicamycin as well as phosphatidylinositol 3-kinase (PI3K) inhibitor of wortmannin on the I/R hearts. The I/R hearts tissue were harvested to evaluate apoptosis ratio with TUNEL assay and protein expression with western blot. Results: We showed that nicorandil ameliorated postischemic contractile recovery, as well as significantly reduced myocardial infarct size at a dose-dependent manner. Furthermore, nicorandil treatment inhibited the IR-induced apoptosis and ER stress. The beneficial effects of nicorandil were blocked by ER stress inducer, tunicamycin and specific phosphatidylinositol 3-kinase (PI3K) inhibitor, wortmannin. Concolusion: We conclude that the cardioprotection of nicorandil was at least in part mediated via inhibition of ER stress-induced apoptotic cell death through PI3K/Akt pathway.
MiR-141 Activates Nrf2-Dependent Antioxidant Pathway via Down-Regulating the Expression of Keap1 Conferring the Resistance of Hepatocellular Carcinoma Cells to 5-Fluorouracil
Authors: Shi Liang , Wu Lili , Chen Zhanguo , Yang Jianrong , Chen Xiaofei , Yu Fangyou , Zheng Fang , Lin Xiangyang
Published: April 2015

Background: Hepatocellular carcinoma (HCC) is one of the most lethal malignancies worldwide. A major cause for the failure of cancer therapy is the development of chemoresistance. Although progress has been made in the study of the mechanisms underlying cancer cells resistance, little is known about the role of microRNAs (miRNAs) in cancer therapy resistance. Methods and Results: Fifteen miRNAs, including 6 up-regulated miRNAs (> 2.0-fold) and 9 down-regulated miRNAs (< 0.5-fold) were differentially expressed in 5-fluorouracil-resistant and their parental cell-lines (HepG2, HepG2/5-FU) by miRNA microarrays. Microarray results were confirmed by validating quantitative real-time polymerase chain reaction (qRT-PCR) analysis. Up-regulation of miR-141 expression resulted in a significant inhibition of 5-FU-mediated cytotoxicity and apoptosis in various hepatocellular carcinoma cells-lines. Mechanically, miR-141 promoted Kelch-like ECH-associated protein 1 (Keap1) mRNA degradation by directly targeting the Keap1 3'untranslated region (3'UTR). Treatment with miR-141 mimics in parental HepG2 cells, restored miR-141 expression and reduced Keap1 levels, thereby resulting in erythroid transcription factor NFE2-L2 (Nrf2) nuclear translocation, activation of Nrf2-dependent HO-1 gene transcription, and subsequent enhancement in 5-FU resistance. Conversely, restoring the expression of Keap1 partly recovered 5-FU sensitivity by counteracting miR-141-mediated 5-FU resistance. Conclusion: Our study showed that miR-141 plays a key role in 5-FU resistance by down-regulating Keap1 expression, thereby reactivating the Nrf2-dependent antioxidant pathway, which may serve as a potential target for overcoming 5-FU resistance in hepatocellular carcinoma cells.
Human Umbilical Cord-Derived Mesenchymal Stem Cells Improve Learning and Memory Function in Hypoxic-Ischemic Brain-Damaged Rats via an IL-8-Mediated Secretion Mechanism Rather than Differentiation Pattern Induction
Authors: Zhou Xiaoqin , Gu Jialu , Gu Yan , He Mulan , Bi Yang , Chen Jie , Li Tingyu
Published: April 2015

Background: MSCs are a promising therapeutic resource. Paracrine effects and the induction of differentiation patterns are thought to represent the two primary mechanisms underlying the therapeutic effects of mesenchymal stem cell (MSC) transplantation in vivo. However, it is unclear which mechanism is involved in the therapeutic effects of human umbilical cord-derived MSC (hUC-MSC) transplantation. Methods and Results: Based on flow cytometry analysis, hUC-MSCs exhibited the morphological characteristics and surface markers of MSCs. Following directed neural induction, these cells displayed a neuron-like morphology and expressed high levels of neural markers. All types of hUC-MSCs, including differentiated and redifferentiated cells, promoted learning and memory function recovery in hypoxic-ischemic brain damaged (HIBD) rats. The hUC-MSCs secreted IL-8, which enhanced angiogenesis in the hippocampus via the JNK pathway. However, the differentiated and redifferentiated cells did not exert significantly greater therapeutic effects than the undifferentiated hUC-MSCs. Conclusion: hUC-MSCs display the biological properties and neural differentiation potential of MSCs and provide therapeutic advantages by secreting IL-8, which participates in angiogenesis in the rat HIBD model. These data suggest that hUC-MSC transplantation improves the recovery of neuronal function via an IL-8-mediated secretion mechanism, whereas differentiation pattern induction was limited.
Establishing Assistant Diagnosis Models of Solitary Pulmonary Nodules Based on Intelligent Algorithms
Authors: Zhao Zhijun , Chen Jingtao , Yin Xiaoxiang , Song Huayong , Wang Xinchun , Wang Jing
Published: April 2015

Aims: This study aimed to establish an auxiliary diagnosis model for solitary pulmonary nodules (SPNs) and evaluate its test efficacy. Methods: Three hundred thirty-two pathologically diagnosed SPN patients (186 malignant, 146 benign) were collected as subjects. The serum levels of 8 types of markers and 9 computed tomography (CT) imaging features of each patient were treated as independent variables. The corresponding pathological classification results (fungal inflammation, tuberculosis and tuberculoma, inflammatory pseudotumor, tumor middle differentiation, cancer) of quantized patients were treated as dependent variables. A 17-to-1 mathematical auxiliary SPN diagnosis model was established using a back propagation (BP) algorithm and a support vector machine (SVM) algorithm. A 40-case test set was used to estimate the effect. Results: Two different auxiliary SPN diagnosis models were successfully established. The diagnostic accuracy, sensitivity and specificity of the BP algorithm diagnosis model were 60%, 68% and 46.7%, respectively, and those of the SVM algorithm model were 80%, 85.7% and 66.7%, respectively. Conclusion: The accuracy, sensitivity and specificity of the SVM diagnostic model were relatively high, indicating that the model has important reference value for determining the degree of SPN differentiation and is suitable for the auxiliary diagnosis of benign and malignant SPN.
Decreased Right Hippocampal Volumes and Neuroprogression Markers in Adolescents with Bipolar Disorder
Authors: Inal-Emiroglu F. Neslihan , Resmi Halil , Karabay Nuri , Guleryuz Handan , Baykara Burak , Cevher Nagihan , Akay Aynur
Published: April 2015

Objectives: The aim of the present study was to assess differences and correlations between the hippocampal volumes (HCVs), serum nerve growth factor (NGF), and brain-derived neurotrophic factor (BDNF) levels in adolescents with bipolar disorder (BP) compared to healthy controls. Methods: Using structural magnetic resonance imaging, we compared HCVs of 30 patients with euthymic BP who were already enrolled in a naturalistic clinical follow-up. For comparison, we enrolled 23 healthy controls between the ages of 13 and 19. The boundaries of the hippocampus were outlined manually. The BDNF and NGF serum levels were measured with the sandwich ELISA. Results: The groups did not differ in the right or left HCVs or in the NGF or BDNF serum levels. However, negative correlations were found between the right HCVs and the duration of the disorder and medication and positive correlations were found between the duration of the medications and the NGF and BDNF levels in the patient group. Additionally, positive correlations were found between the follow-up period and left normalized HCVs in both the BP and lithium-treated groups. Conclusions: The right HCVs may vary with illness duration and the medication used to treat BP; NGF and BDNF levels may be affected by long-term usage. Further research is needed to determine whether these variables and their structural correlates are associated with clinical or functional differences between adolescents with BP and healthy controls.