bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of leakage flow through a spool valve under blocked-actuator port condition—Simulation and experiment
Authors: Mondal Milan K , Manna Nirmal K , Saha Rana
Published: October 2013

The spool valve is the key component of hydraulic control system, and the performance of spool valve depends on its leakage behaviour. Again, the leakage flow of spool valve is highly susceptible to valve uncertain dimensions, radial clearance and overlap or underlap. In the present work, the relative performance of critically lapped, underlapped and overlapped valves has been demonstrated in terms of leakage flow rate and pressure sensitivity about the metered ports. An approach to explore uncertain dimensions of the valve has been developed using CFD as an investigating tool. The comparison of CFD prediction against experimental results has also been carried out. It is found that the CFD predictions are in excellent agreement with the experimental results.
Numerical study on the steady-state heat transfer rate of nanofluid filled within square cavity in the presence of oriented magnetic field
Authors: Koopaee Masoud K , Omidvar Amir , Jelodari Iman
Published: October 2013

In this paper, the steady-state natural convection in a square cavity filled with water–Al2O3 nanofluid in the presence of magnetic fields with variable inclination angles is investigated numerically. The enclosure is subjected to different side-wall temperatures while the top and bottom walls are assumed to be adiabatic. The thermal behavior of enclosure is assessed using a finite volume-based computer program. In order to ensure the accuracy of results, comparisons are also made with a previous published work. In this research, at constant magnetic field strengths, the effect of magnetic field inclination angle on the rate of heat transfer in the square cavity is investigated at the Rayleigh numbers of Ra = 103, 104, 105 and 106. In this work, the Hartmann number ranges from Ha = 0 to 120 and the solid volume fraction varies from φ = 0 to 0.06. Numerical results show that depending on the Rayleigh and Hartmann numbers, the maximum heat transfer rate may occur at magnetic field inclination angles of 45°, 60° or 90° and the effect of magnetic field inclination angle is significant at high values of Rayleigh and Hartmann numbers. It is found that addition of nano-sized solid particles causes higher heat transfer rate when Ra = 103, whereas at Rayleigh number of Ra = 106, a reverse behavior is observed. Results show that at Rayleigh numbers of Ra = 104 and 105, the effect of solid particles addition on the thermal performance of the enclosure depends on the Hartmann number. It is also shown that an increase in the inclination angle causes higher velocity within the enclosure and addition of solid particles leads to suppression of flow field.
Study of the sensitivity and resonant frequency of the flexural modes of an atomic force microscopy microcantilever modeled by strain gradient elasticity theory
Authors: Abbasi Mohammad , Mohammadi Ardeshir Karami
Published: October 2013

In this study, the resonant frequency and sensitivity of an atomic force microscopy microcantilever are analyzed utilizing the strain gradient theory, and then the governing equation and boundary conditions are derived by a combination of the basic equations of the modified strain gradient theory and the Hamilton principle. Afterward, the resonant frequency and sensitivity of the proposed atomic force microscopy microcantilever are obtained numerically. The results of the current model are compared to those evaluated by both modified couple stress and classic beam theories. Results show that utilizing the strain gradient theory in the analysis of atomic force microscopy microcantilever dynamic behavior is necessary especially when the contact stiffness is high and the thickness of the microcantilever approaches the internal material length scale parameter.
Analysis of friction-induced vibration in a propeller–shaft system with consideration of bearing–shaft friction
Authors: Zhang Zhenguo , Chen Feng , Zhang Zhiyi , Hua Hongxing
Published: October 2013

This paper is concerned with friction-induced vibration of a continuous propeller–shaft system excited by nonlinear friction due to contact between a water-lubricated bearing and a shaft. The dynamic equation is derived using Hamilton’s principle in conjunction with the finite element method. The drooping characteristics of the nonlinear friction and the torsional–lateral coupling via the bearing–shaft interaction laws are considered. Both stability analysis and responses analysis are then investigated through various system parameters. Stability is analyzed by determining the eigenvalues of the Jacobian matrix of the linearized system at the equilibrium point. Dynamic responses of the system are calculated on the basis of a reduced order modal model using the numerical integration method in order to validate the stability analysis. Numerical simulation proved to be consistent with the linear stability analysis. Analytical and numerical investigations reveal that friction-induced vibration of the proposed system is due to the combined action of nonlinear friction and coupled dynamics of the system, rather than the velocity-dependent friction alone as is commonly assumed.
Hybrid interface of a two-dimensional cubic Hermite curve oversketch and a three-dimensional spatial oversketch for the conceptual body design of a car
Authors: Nam Sanghun , Patil Ashok Kumar , Patil Shashidhar , Chintalapalli Harinadha Reddy , Park Kyoungju , Chai Youngho
Published: October 2013

A spatial modelling system with a new interface which is optimized for automotive design is proposed in the conceptual modelling phase. In the initial sketch stage to set the volume and the ratio of the car, the automotive styling is created using a two-dimensional plane sketch with an accurate input and a designer-friendly interface. The character lines, which have important implications in the design of the car, are drawn with a curve-based oversketch. The shape of the car is modified using area-based modification. A completed two-dimensional model consists of converting the character lines to a three-dimensional car model. In the three-dimensional spatial oversketch stage, the edge and mesh on the surface are deformed by viewing the three-dimensional shape of the vehicle with various views using a spatial input device and stereoscopic display. Edge-based deformation modifies single or multiple edges while maintaining continuity between the surfaces. A sculpting technique is applied to execute special shapes such as the accent lines and the strake lines. A sketch system which can be used by designers to perform three-dimensional spatial modelling is proposed.
Performance and emission characteristics of a diesel engine operated with wood pyrolysis oil
Authors: Lee Seokhwan , Kim Taeyoung , Kang Kernyong
Published: October 2013

The vast storage of biomass available worldwide has the potential to displace the significant amounts of fuel that are currently derived from petroleum sources. Fast pyrolysis of biomass is one of the possible paths by which we can convert biomass to higher-value products. Wood pyrolysis oil has been regarded as an alternative fuel to petroleum fuels for use in diesel engines. However, the use of wood pyrolysis oil in diesel engines requires modifications to those engines owing to the low energy density, the high water content, the high acidity and the high viscosity of wood pyrolysis oil. The easiest ways to adopt wood pyrolysis in a diesel engine without engine modifications are blending or emulsification of the wood pyrolysis oil with diesel or biodiesel. Wood pyrolysis oil is immiscible with diesel and biodiesel; hence appropriate surfactants or co-solvents are needed for emulsification or blending. In this study, a diesel engine operated with diesel, biodiesel, wood pyrolysis oil–diesel emulsion and wood pyrolysis oil–biodiesel emulsion was investigated experimentally. The combustion performance and the gaseous and particle emission characteristics of a diesel engine fuelled by diesel, biodiesel and wood pyrolysis oil emulsions were examined. The results showed that stable engine operation was possible with the emulsions and that the engine output power was comparable with those of diesel and biodiesel operation. However, in the case of wood pyrolysis oil–diesel emulsion operation, the total hydrocarbon and carbon monoxide emissions were increased owing to the increased ignition delay and poor spray atomization, and the nitogen oxide and the soot emissions were decreased owing to the high water content and the high oxygen content in the fuel. Long-term validation of adopting wood pyrolysis oil in diesel engines is still needed because the oil is acidic, with the consequent problems of corrosion and clogging, especially in the injection system.
Understanding Health Constraints Among Rural-to-Urban Migrants in China
Authors: Li Yan
Published: October 2013

The main purpose of this article is to examine the understanding and experience of health and health care among rural-to-urban migrants in China, and to explain the impact of the internal factors of migrants themselves and the external factors of their social environment. Understanding the perceptions and consciousness of health issues among migrants is crucial to prevention, intervention, and other health-related measures for the migrant population in China, but this has rarely been explored in studies. On the basis of a case study of a migrant community in Beijing, I explore the migrants’ understandings of health and health care and analyze factors in the social environment, including exclusion from the social system and the possibility of health participation, exclusion from social relation networks, obstructed channels of health maintenance, and exclusion of crowd psychology, which impact heavily on their health understanding and health behavior. I argue that the internal and the external factors are linked together closely and interact as reciprocal causation. However, the migrants should not be seen as primarily responsible, because their poor understanding of health mainly results from the socioeconomic environment in which they live and work.
Understanding the Experiences of Hearing Voices and Sounds Others Do Not Hear
Authors: Kalhovde Anne Martha , Elstad Ingunn , Talseth Anne-Grethe
Published: October 2013

In this article, we aim to contribute to the understanding of how people with mental illness experience hearing voices and sounds that others do not hear in daily life. We conducted in-depth interviews with 14 people and analyzed the interviews using a hermeneutic phenomenological approach. The themes we arrived at included the following: hearing someone else or myself, am I losing my mind?, and daily life recurrently dominated by opposing voices. Our overall understanding of how the voices and sounds were experienced in daily life was that the intentions of others resounded intrusively in the participants and disrupted their lives. The tones and contents of these perplexing perceptions echoed and amplified past, present, and future experiences and concerns. The results elucidate the value that exploring and attempting to understand people’s daily life experiences of hearing voices and sounds might have for the voice hearer, his or her family, and health care providers.
Serious Decisions
Authors: Manderson Lenore , Canaway Rachel
Published: October 2013

People with chronic health conditions combine conventional medical care with different complementary and alternative medicine (CAM) therapies for varying reasons. The data on which we drew to elucidate this derive from a large mixed-methods study utilizing participant observation, in-depth interviews with 69 people with type 2 diabetes mellitus and/or cardiovascular disease (CVD), and interviews with 20 health care providers. Although integrative practices are increasingly common, people make clear choices about and trade-offs between conventional medical care and CAM, often using CAM and prescribed pharmaceuticals in tandem for different conditions and distinct purposes and outcomes. As we illustrate, some people perceived type 2 diabetes and CVD as “too serious” for CAM treatment, but concurrently, many turned to CAM providers in appreciation of the serious attention these providers paid to their health-related concerns.
Astrocyte Plasticity
Authors: Pirttimaki Tiina M. , Parri H. Rheinallt
Published: October 2013

Astrocytes are increasingly implicated in a range of functions in the brain, many of which were previously ascribed to neurons. Much of the prevailing interest centers on the role of astrocytes in the modulation of synaptic transmission and their involvement in the induction of forms of plasticity such as long-term potentiation and long-term depression. However, there is also an increasing realization that astrocytes themselves can undergo plasticity. This plasticity may be manifest as changes in protein expression which may modify calcium activity within the cells, changes in morphology that affect the environment of the synapse and the extracellular space, or changes in gap junction astrocyte coupling that modify the transfer of ions and metabolites through astrocyte networks. Plasticity in the way that astrocytes release gliotransmitters can also have direct effects on synaptic activity and neuronal excitability. Astrocyte plasticity can potentially have profound effects on neuronal network activity and be recruited in pathological conditions. An emerging principle of astrocyte plasticity is that it is often induced by neuronal activity, reinforcing our emerging understanding of the working brain as a constant interaction between neurons and glial cells.
Invisible Hands
Authors: Baumbusch Jennifer , Phinney Alison
Published: October 2013

Care work by family and friends is recognized as a cornerstone of community-based care for older adults; however, the role of families in institutional-based care work has been less well understood and researched. Drawing on findings from a critical ethnographic study, this article aims to examine the unique role of highly involved family members within long-term residential care. The study took place between October 2006 and April 2008 in two facilities in British Columbia, Canada. A purposive sample of 11 highly involved family members participated in in-depth interviews and participant observations. The main themes were “Hands-On,” “Hands-Off,” “Surveillance,” and “Interlopers.” These themes illuminate the ways in which highly involved family members engaged in care work, including how they positioned themselves and were positioned by staff and administrators. Implications of the study focus on the need to include families in philosophies of care and policies that shape care work in long-term residential care.
Geometric control of a flapping plate
Authors: Taha Haithem E , Woolsey Craig A
Published: October 2013

Control of flapping micro-air-vehicles (MAVs) is challenging because the system models are nonlinear and time-varying. Moreover, as internally actuated multi-body systems, flapping MAVs are inherently underactuated. With stringent weight and size constraints, the actuator mechanization must be as simple as possible, introducing a further challenge for control design. Geometric control and averaging theory can be used to design control laws for underactuated nonlinear systems. In this work, we consider control design for a flapping plate with three degrees of freedom and two actuators. The averaging theorem and geometric control methods are used to stabilize and control the system. The simple example demonstrates an algorithmic approach that could be used within a multi-disciplinary design optimization framework for the design of biomimetic vehicles and their gaits.
What do Canadian uro-oncologists believe patients should know about androgen deprivation therapy?
Authors: Tran Susan , Walker Lauren M , Wassersug Richard J , Matthew Andrew G , McLeod Deborah L , Robinson John W
Published: October 2013

Introduction

Patients prescribed luteinizing hormone-releasing hormone agonists for androgen deprivation therapy (ADT) have significant misconceptions about treatment side effects and how to manage them. We surveyed a subset of Canadian physicians about what they think is important information to tell patients starting on ADT to determine the degree to which there is consensus of opinion.

Method

A questionnaire about ADT side effects and management strategies was distributed to physicians–urologists, radiation oncologists, and medical oncologists – actively practicing within cancer and urology centers in the Canadian provinces of British Columbia, Alberta, Ontario, and the Maritime Provinces.

Result

A total of 75 physicians filled out the survey. Physicians agreed that osteoporosis, erectile dysfunction, hot flashes, loss of libido, and loss of muscle mass were drug responses that were essential or important to warn patients about. However, for six commonly reported side effects (i.e. depression, diabetes, elevated cholesterol, anemia, delayed or absent orgasm, and genital shrinkage), physicians showed great variance, with less than 60% agreeing on whether to discuss these topics or not.

Conclusion

There is little consensus among physicians regarding what to tell patients when prescribing this treatment. The lack of agreement among physicians may partially explain the lack of awareness of ADT side effects by patients and partners. The current findings may help guide strategies for the design, evaluation, and implementation of educational interventions for both physicians and patients that will better prepare patients to recognize, adapt to, and overcome ADT side effects.
Utilization of bevacizumab in US elderly patients with colorectal cancer receiving chemotherapy
Authors: Fu Alex Z , Tsai Huei-Ting , Marshall John L , Freedman Andrew N , Potosky Arnold L
Published: October 2013

Objective

Bevacizumab, the first FDA-approved anti-angiogenesis agent, has been used for metastatic colorectal cancer since 2004. This study evaluated the utilization of bevacizumab among elderly metastatic colorectal cancer patients in the United States.

Methods

Using Surveillance and Epidemiology and End Results (SEER)-Medicare data, this retrospective cohort study consisted of individuals aged 65 years or older with a colorectal cancer diagnosis between 2005 and 2009, who received chemotherapy any time through 2010. This included patients with newly diagnosed metastatic colorectal cancer and patients who progressed from initially diagnosed earlier-stage disease. We ascertained comorbid conditions using ICD-9 codes and conducted logistic regression to identify patients’ characteristics associated with bevacizumab use.

Results

A total of 8645 patients were identified (mean age 74 years; 52% male); 57% of patients received bevacizumab with initially diagnosed metastatic colorectal cancer and 44% of patients with treated progressive or recurrent disease. After adjusting for other covariates, we found that patients aged ≥80 years were less likely to receive bevacizumab compared with those aged 65–69 years (odds ratio (OR), 0.64 (95% confidence interval (CI): 0.57–0.73)), or if they had evidence of comorbid cardiomyopathy/congestive heart failure (OR, 0.82 (CI: 0.70–0.95)) or arrhythmic disorder (OR, 0.85 (CI: 0.75–0.96)). Adoption of bevacizumab into practice was rapid following its approval, and the use increased from 36% to 40% from 2005 to 2010 ( p = 0.013). There were significant regional variations in bevacizumab use.

Conclusions

Despite rapid uptake since its original approval, there appears to be low use of bevacizumab in elderly metastatic colorectal cancer patients in the United States. Regional variations and the strong effects of age and comorbidity suggest lack of consensus among oncologists regarding benefits and risks of bevacizumab in elderly patients.
BenchFriend
Authors: Che Shuai , Skadron Kevin
Published: October 2013

Graphics processing units (GPUs) have become an important platform for general-purpose computing, thanks to their high parallel throughput and high memory bandwidth. GPUs present significantly different architectures from CPUs and require specific mappings and optimizations to achieve high performance. This makes GPU workloads demonstrate application characteristics different from those of CPU workloads. It is critical for researchers to understand the first-order metrics that most influence GPU performance and scalability. Furthermore, methodologies and associated tools are needed to analyze and predict the performance of GPU applications and help guide users’ purchasing decisions.

In this work, we study the approach of predicting the performance of GPU applications by correlating them to existing workloads. One tenet of benchmark design, also a motivation of this paper, is that users should be given the capability to leverage standard workloads to infer the performance of applications of their interest. We first identify a set of important GPU application characteristics and then use them to predict performance of an arbitrary application by determining its most similar proxy benchmarks. We demonstrate the prediction methodology and conduct predictions with benchmarks from different suites to achieve better workload coverage. The experimental results show that we are able to achieve satisfactory performance predictions, although errors are higher for outlier applications. Finally, we discuss several considerations for systematically constructing future benchmark suites.
The poverty of (moral) philosophy
Authors: Morgan Marcus
Published: October 2013

This article makes both a more general and a more specific argument, and while the latter relies upon the former, the inverse does not apply. The more general argument proposes that empirical disciplines such as sociology are better suited to the production of ethical knowledge than more characteristically abstract and legalistic disciplines such as philosophy and theology. The more specific argument, which is made through a critique of Bauman’s Levinasian articulation of ethics, proposes what it calls ‘pragmatic humanism’ as a viable alternative model for sociological ethics to follow. This model rejects the abstract notion of some innate and universally distributed moral impulse, and instead turns to acknowledgement of the precariousness of life as a strategic resource in the construction, rather than revelation, of ethical solidarity.
Underground soil and thermal conductivity materials based heat reduction for energy-efficient building in tropical environment
Authors: Alam M. R. , Zain M. F. M. , Kaish A. B. M. A. , Jamil M.
Published: October 2013

In this paper, an alternative way of releasing heat of building is investigated in order to reduce energy demand of building built in tropical environment. Underground soil is considered as a source for extracting heat from building through thermal conductivity pipes. Thermal conductivity pipes are considered to be fixed on the inner faces of the walls and their lower part to be inserted to the ground where temperature is lower than the indoor temperature. The entire analyses were done numerically using ANSYS 11. Heat flow between two systems was studied and the performance of the thermal conductivity pipes was examined. The room temperature in the presence of thermal conductivity pipes as well as mechanical cooling system and other passive energy-efficient techniques of building were also studied. The underground soil was demonstrated to act as a heat sink and absorb heat released from the rooms and the thermal conductivity pipes would play a role in transferring heat from the rooms to the underground soil. The system works efficiently when it is used with other mechanical or passive cooling systems. In this way, energy saving measure could be possible to reduce building temperatures by around 3℃.
Peroneal artery pseudoaneurysm after surgical stabilisation of a Weber C trimalleolar ankle fracture: A case report and review of literature
Authors: Shah AR , Khan SK , Adair W , Chatterji U
Published: October 2013

A case of post-traumatic pseudoaneurysm of the peroneal artery is presented. This occurred after standard open reduction and internal fixation of a Weber type C trimalleolar fracture of the left ankle in a 33-year-old man. The pseudoaneurysm was diagnosed 12 weeks post-operatively when the patient attended the pre-assessment clinic for the removal of the syndesmosis screw. Diagnosis was confirmed on ultrasonography, and the anatomical site was confirmed by a digital subtraction angiogram. The pseudoaneurysm was coiled successfully, and the syndesmosis screw was removed in theatre the next day, without any post-operative complications. We explore the aetiology of post-traumatic peroneal pseudoaneurysms, with emphasis on the pathoanatomy and management as described in literature. This is a rare complication, but is easily manageable provided an index of suspicion is maintained.
Training Methods
Authors: Martin Barbara Ostrowski , Kolomitro Klodiana , Lam Tony C. M.
Published: October 2013

In reviewing training methods reported in the literature, 13 were identified: case study, games-based training, internship, job rotation, job shadowing, lecture, mentoring and apprenticeship, programmed instruction, role-modeling, role play, simulation, stimulus-based training, and team-training. The nature and characteristics of these training methods and the relationships among them were analyzed using the following seven criteria: learning modality, learning environment, trainer presence, proximity, interaction level, cost considerations, and time demands. Results from this in-depth review suggest that the majority of training methods are not interactive, involve doing, and are off-the-job. As expected, it also concluded that technological advancements have expanded the delivery mode to various distance options. Profiles for the 13 identified training methods generated from this research should assist practitioners in selecting training methods most suitable for their needs and circumstances and serve as a platform for future research and development.
Percutaneous Endovascular Y-Stenting of a Malignant Superior Vena Cava and Innominate Vein Obstruction
Authors: Cordial Reginald , Moussavian Mohammed Reza , Corvalan José , Görtz Hartmut , Teßarek Jörg
Published: October 2013

Superior vena cava syndrome (SVCS) is considered one of the telltale signs of a terminal malignant process. We describe a successful endovascular desobliteration of a subtotal occluded SVC and the left innominate vein using a Y-stent technique in a 46-year-old female with a mediastinal nodal metastasis of a relapsing renal cell carcinoma. Complete clinical improvement in the symptoms within the first 24 hours of the procedure and no complication were observed. This report describes endovascular stenting of the SVC as a palliation therapy to overcome the severe clinical symptoms of SVCS besides surgical or chemotherapy in mediastinal malignancy masses.
A Comparison Between Customized and Premixed Parenteral Nutrition
Authors: Anantha Sathyanarayana Sandeep , Deutsch Gary B. , Singh Narendra , Barrera Rafael
Published: October 2013

Background. Parenteral route is accepted for delivering nutrition when enteral feeding is not possible. Standardized premixed parenteral nutrition solution (SPNS) formulations are uniform in their characteristics and can be chosen based on the same nutrient calculations. We compared the feasibility of administering SPNS as an alternative to customized parenteral nutrition solution (CPNS) and calculate its cost implications. Methods. Retrospective review of 47 patients receiving CPNS at a tertiary care hospital ICU was performed and compared with SPNS formulations. The amounts of macro- and micronutrients (days 1, 3, 5, 7) were recorded and averaged to 2000-mL bag. These data were compared with the available premixed formulations and percentage differences were calculated. The costs and manpower for CPNS were obtained from our institutional central pharmacy. Results. The percentage difference for carbohydrates and proteins ranged from −1.0% to 2.9% and 5.8% to 9.0% with an average of 0.8% and 7.0%, respectively across all days. Since premixed micronutrients were only available in one formula, they were not easily comparable. The cost analysis showed an average savings of approximately $130 per parenteral nutrition bag. Conclusions. While macronutrients are quite comparable between formulations, any required micronutrients should be managed individually. SPNS has potential cost savings compared with CPNS when applied in the right setting.
Intervene to be Seen
Authors: van Bommel Marco , van Prooijen Jan-Willem , Elffers Henk , van Lange Paul A. M.
Published: October 2013

Security cameras became such a part of everyday life that their presence may escape from our conscious attention. The present research examines the impact of cameras on intervening in crime, a situation in which the classic bystander effect has been uncovered. In our experimental set up, participants witnessed how another participant (a confederate) stole money, in the presence of either two or no other bystanders. Moreover, we used a security camera to make people feel watched. We expected to replicate the bystander effect without security camera’s presence and an attenuation of the bystander effect with a security camera present. As expected, the findings revealed that without a camera, participants were less likely to stop our confederate from stealing money when other bystanders were present. However, when there was a camera present this effect was attenuated: The camera increased intervention when people are otherwise least likely to help—when other bystanders are present.
Rituximab maintenance after first-line therapy with rituximab, fludarabine, cyclophosphamide, and mitoxantrone (R-FCM) for chronic lymphocytic leukemia
Authors: Abrisqueta Pau , Villamor Neus , Terol María José , González-Barca Eva , González Marcos , Ferrà Christelle , Abella Eugenia , Delgado Julio , García-Marco Jose A. , González Yolanda , Carbonell Felix , Ferrer Secundino , Monzó Encarna , Jarque Isidro , Muntañola Ana , Constants Mireia , Escoda Lourdes , Calvo Xavier , Bobillo Sabela , Montoro José Bruno , Montserrat Emili , Bosch Francesc
Published: October 2013

Key Points

Maintenance rituximab attained a prolonged PFS and improved the quality of response in patients with detectable disease after R-FCM.
Thermal imaging comparison of Signature, Infiniti, and Stellaris phacoemulsification systems
Authors: Ryoo Na Kyung , Kwon Ji-Won , Wee Won Ryang , Miller Kevin M , Han Young Keun
Published: October 2013

Background

To compare the heat production of 3 different phacoemulsification machines under strict laboratory test conditions. More specifically, the thermal behavior was analyzed between the torsional modality of the Infiniti system and longitudinal modalities of the Abbot WhiteStar Signature Phacoemulsification system and Bausch and Lomb Stellaris system.

Methods

Experiments were performed under in-vitro conditions in this study.

Three phacoemulsification handpieces (Infiniti, Signature, and Stellaris) were inserted into balanced salt solution-filled silicone test chambers and were imaged side-by-side by using a thermal camera. Incision compression was simulated by suspending 30.66-gram weights from the silicone chambers. The irrigation flow rate was set at 0, 1, 2, 3, 4, and 5 cc/min and the phacoemulsification power on the instrument consoles was set at 40, 60, 80, and 100%. The highest temperatures generated from each handpiece around the point of compression were measured at 0, 10, 30, and 60 seconds.

Results

Under the same displayed phacoemulsification power settings, the peak temperatures measured when using the Infiniti were lower than when using the other two machines, and the Signature was cooler than the Stellaris. At 10 seconds, torsional phacoemulsification with Infiniti at 100% power showed data comparable to that of the Signature at 80% and the Stellaris at 60%. At 30 seconds, the temperature from the Infiniti at 100% power was lower than the Signature at 60% and the Stellaris at 40%.

Conclusions

Torsional phacoemulsification with the Infiniti generates less heat than longitudinal phacoemulsification with the Signature and the Stellaris. Lower operating temperatures indicate lower heat generation within the same fluid volume, which may provide additional thermal protection during cataract surgery.
Cellular response to micropatterned growth promoting and inhibitory substrates
Authors: Belkaid Wiam , Thostrup Peter , Yam Patricia T , Juzwik Camille A , Ruthazer Edward S , Dhaunchak Ajit S , Colman David R
Published: October 2013

Background

Normal development and the response to injury both require cell growth, migration and morphological remodeling, guided by a complex local landscape of permissive and inhibitory cues. A standard approach for studying by such cues is to culture cells on uniform substrates containing known concentrations of these molecules, however this method fails to represent the molecular complexity of the natural growth environment.

Results

To mimic the local complexity of environmental conditions in vitro, we used a contact micropatterning technique to examine cell growth and differentiation on patterned substrates printed with the commonly studied growth permissive and inhibitory substrates, poly-L-lysine (PLL) and myelin, respectively. We show that micropatterning of PLL can be used to direct adherence and axonal outgrowth of hippocampal and cortical neurons as well as other cells with diverse morphologies like Oli-neu oligodendrocyte progenitor cell lines and fibroblast-like COS7 cells in culture. Surprisingly, COS7 cells exhibited a preference for low concentration (1 pg/mL) PLL zones over adjacent zones printed with high concentrations (1 mg/mL). We demonstrate that micropatterning is also useful for studying factors that inhibit growth as it can direct cells to grow along straight lines that are easy to quantify. Furthermore, we provide the first demonstration of microcontact printing of myelin-associated proteins and show that they impair process outgrowth from Oli-neu oligodendrocyte precursor cells.

Conclusion

We conclude that microcontact printing is an efficient and reproducible method for patterning proteins and brain-derived myelin on glass surfaces in order to study the effects of the microenvironment on cell growth and morphogenesis.
Evaluation of ergonomic and education interventions to reduce occupational sitting in office-based university workers: study protocol for a randomized controlled trial
Authors: Radas Antonia , Mackey Martin , Leaver Andrew , Bouvier Anna-Louise , Chau Josephine Y , Shirley Debra , Bauman Adrian
Published: October 2013

Background

Prolonged sitting is a specific occupational hazard in office workers. There is growing evidence that prolonged sitting is detrimental to metabolic health. The aim of this study is to determine whether providing office workers with education along with adjustable sit-stand workstations leads to reduction in sitting behavior.

Methods/Design

A randomized control trial (RCT) with three groups (one control group and two intervention groups) will be conducted in an office workplace setting. The education intervention group will receive an education package that encourages reduction in sitting behaviors. The sit-stand desk intervention group will receive the same education package along with an adjustable sit-stand desk. Participants will be included in the study if they are currently employed in a full-time academic or administrative role that involves greater than 15 hours per week or greater than 4 hours per day computer-based work. Baseline data will include participant’s age, gender, weight, height, smoking habit, employment position, level of education, and baseline self-reported leisure time physical activity. The primary outcome is the average daily sedentary time during work hours, measured by an accelerometer. Participant recruitment commenced in March 2013 and will be completed by December 2013.

Discussion

This study will determine whether providing office workers with an adjustable sit-stand desk and individually targeted education, or education alone, is more effective in decreasing sitting behaviors than no intervention.

Trial registration

Australian New Zealand Clinical Trials Registry:ACTRN12613000366752
Sustained, neuron-specific IKK/NF-κB activation generates a selective neuroinflammatory response promoting local neurodegeneration with aging
Authors: Maqbool Ayesha , Lattke Michael , Wirth Thomas , Baumann Bernd
Published: October 2013

Background

Increasing evidence indicates that neuroinflammation is a critical factor contributing to the progression of various neurodegenerative diseases. The IKK/NF-κB signalling system is a central regulator of inflammation, but it also affects neuronal survival and differentiation. A complex interplay between different CNS resident cells and infiltrating immune cells, which produce and respond to various inflammatory mediators, determines whether neuroinflammation is beneficial or detrimental. The IKK/NF-κB system is involved in both production of and responses to these mediators, although the precise contribution depends on the cell type as well as the cellular context, and is only partially understood. Here we investigated the specific contribution of neuronal IKK/NF-κB signalling on the regulation of neuroinflammatory processes and its consequences. To address this issue, we established and analysed a conditional gain-of-function mouse model that expresses a constitutively active allele of IKK2 in principal forebrain neurons (IKK2nCA). Proinflammatory gene and growth factor expression, histopathology, microgliosis, astrogliosis, immune cell infiltration and spatial learning were assessed at different timepoints after persistent canonical IKK2/NF-κB activation.

Results

In contrast to other cell types and organ systems, chronic IKK2/NF-κB signalling in forebrain neurons of adult IKK2nCAanimals did not cause a full-blown inflammatory response including infiltration of immune cells. Instead, we found a selective inflammatory response in the dentate gyrus characterized by astrogliosis, microgliosis and Tnf-α upregulation. Furthermore, downregulation of the neurotrophic factor Bdnf correlated with a selective and progressive atrophy of the dentate gyrus and a decline in hippocampus-dependent spatial learning. Neuronal degeneration was associated with increased Fluoro-jade staining, but lacked activation of apoptosis. Remarkably, neuronal loss could be partially reversed when chronic IKK2/NF-κB signalling was turned off and Bdnf expression was restored.

Conclusion

Our results demonstrate that persistent IKK2/NF-κB signalling in forebrain neurons does not induce overall neuroinflammation, but elicits a selective inflammatory response in the dentate gyrus accompanied by decreased neuronal survival and impaired learning and memory. Our findings further suggest that chronic activation of neuronal IKK2/NF-κB signalling, possibly as a consequence of neuroinflammatory conditions, is able to induce apoptosis-independent neurodegeneration via paracrine suppression of Bdnf synthesis.
Ectopic acromegaly due to a GH-secreting pituitary adenoma in the sphenoid sinus: a case report and review of the literature
Authors: Ramírez Claudia , Hernández-Ramirez Laura-Cristina , Espinosa-de-los-Monteros Ana-Laura , Franco Juan Manuel , Guinto Gerardo , Mercado Moises
Published: October 2013

Background

In more than 98% of cases, acromegaly is due to a GH-secreting pituitary adenoma. The term “ectopic acromegaly” includes neuroendocrine tumors secreting GH releasing hormone (GHRH), usually located in the lungs, thymus and endocrine pancreas. Considerably less frequent are cases of ectopic acromegaly due to GH-secreting tumors located out of the pituitary fossa; except for one isolated case of a well-documented GH-secreting lymphoma, the majority of these lesions are located in the sphenoid sinus.

Case presentation

We present the case of a 45 year old woman with acromegaly whose MRI showed an empty sella without evidence of a pituitary adenoma but revealed a large mass within the sphenoid sinus. She underwent transsphenoidal surgery and the excised sphenoid sinus mass, proved to be a GH-secreting adenoma; the sellar floor was intact and no other lesions were found in the pituitary fossa. She required postoperative treatment with somatostatin analogs and cabergoline for clinical and biochemical control.

Conclusions

This case highlights the importance of carefully evaluating the structures surrounding the sellar area when a pituitary adenoma is not found with currently available imaging techniques. The finding of an intact sellar floor and duramater lead us to conclude that the patient’s tumor originated de novo from embryological pituitary remnants. Upon a careful review of the literature and a critical evaluation of our case we found neither clinical nor biochemical features that would distinguish an ectopic from the more common eutopically located somatotrophinoma.
Novel cell surface adhesion receptors involved in interactions between stromal macrophages and haematopoietic cells
Authors: Crocker Paul R. , Morris Lynn , Gordon Siamon
Published: October 2013

Immunocytochemical staining of tissues with the mouse macrophage-specific monoclonal antibody, F4/80, has shown that large numbers of stromal macrophages are present in adult and foetal haematopoietic tissues. Macrophage plasma membrane processes are seen to establish extensive associations with myeloid and erythroid cells in adult bone marrow and with developing erythroblasts in foetal liver, suggestive of local trophic interactions. To explore the nature of these interactions, methods were developed for isolation of resident bone marrow macrophages (RBMM) and foetal liver macrophages (FLM). Following collagenase digestion of bone marrow or foetal liver, clusters were obtained which were composed of one or more central macrophages surrounded by proliferating haematopoietic cells. After attachment of clusters to glass coverslips, adherent macrophages could be stripped free of haematopoietic cells by pipetting in the absence of divalent cations. The purified RBMM, but not FLM, expressed a novel haemagglutinin, which mediated binding, without ingestion, of large numbers of unopsonized sheep erythrocytes by a divalent cation-independent mechanism. In view of the possibility that this sheep erythrocyte receptor (SER) could interact with a homologous ligand on mouse bone marrow cells, its properties were examined. SER was found to be a lectin-like protein which recognized protease-resistant sialylated glycoconjugates on sheep erythrocytes. The expression of SER was restricted to certain stromal tissue macrophages and was low or absent on monocytes and macrophages obtained from serous cavities. High levels of SER could be induced on elicited peritoneal macrophages by cultivation in mouse serum and the induced receptor was found to mediate low-avidity binding of murine bone marrow cells with characteristics indistinguishable from those seen for binding of sheep erythrocytes. However, maximal binding of bone marrow cells to RBMM depended on a distinct, divalent cation-dependent adhesion system. Using erythroblasts as a ligand, FLM were selected to explore the properties and expression of this adhesion receptor, the erythroblast receptor (EbR). Similar to SER, EbR did not mediate ingestion, and was restricted in its expression to foetal and adult stromal tissue macrophages. Unlike SER, EbR activity was not affected by neuraminidase treatment of the ligand and the receptor was not induced on peritoneal macrophages cultured in mouse serum. EbR appears to be a novel cell adhesion receptor because it was unaffected by inhibitors of several previously described cell adhesion molecules, including the fibronectin receptor. Future studies will attempt to explore the functional significance of these two receptors in macrophage-haematopoietic cell interactions.
The structure and function of vertebrate mannose lectin-like proteins
Authors: Ezekowitz R. A. B. , Stahl P. D.
Published: October 2013

Sugar-specific recognition is now well established as an important determinant of cell-cell interactions and host defence mechanisms. Macrophages, in particular, are known to express a variety of lectin-like proteins that are specific for oligosaccharides terminating in mannose, fucose, galactose and sialic acid. This review focuses on mannose recognition systems. Terminal mannose is rarely found on mammalian cell surfaces whereas it is ubiquitous on the surfaces of lower organisms. Mammals have evolved at least two mechanisms to recognize terminal mannose residues. These are, first, a mannose receptor located on the surface of macrophages and second, a mannose-binding protein found in blood plasma and secreted by hepatocytes. The mannose receptor is a 175K (K = 103Mr) membrane glycoprotein. The receptor binds glycoproteins bearing high-mannose chains avidly at neutral pH but poorly at pH 5-6. The receptor recycles rapidly between the cell surface, where ligand binding occurs, and various acid intracellular compartments, where the ligand is discharged. The pH dependency of binding and the rapid recycling of receptor allow cells to accumulate many ligand molecules over an extended time. Endocytosis via this pathway appears to be regulated since mannose receptor expression is closely regulated. For example, the receptor is absent from monocytes but strongly expressed on 3-to 4-day-old monocyte-derived macrophages. Receptor expression can be up-and down-regulated by antiinflammatory steroids and γ interferon, respectively. The mechanisms are poorly understood as is the physiological basis for modulation.

The mannose-binding protein is a large oligomeric plasma protein secreted by liver and present in significant amounts in serum. The basic subunit of the mannose-binding protein is a 32K protein, which shows homology with other lectin-like proteins, notably certain surfactant proteins of the lung. The structure of the mannose-binding protein has been deduced from sequence information and DNA cloning experiments. The elaboration of the mannose-binding protein by the liver is regulated; it appears to be an acute phase reactant. Recent evidence suggests that the mannose-binding protein may play some opsonic role in the recognition and killing of organisms. In this review, it is suggested that the mannose receptor and the mannose-binding protein operate ‘hand in glove’ to deal with infectious agents that express mannose on their surfaces.