bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Filling of Semi-Solid during Thixocasting
Authors: Seyed Vakili Seyed Vahidreza , Nili-Ahmadabadi Mahmoud
Published: October 2012

Thixoforming is a new forming technology which has been studied by many researchers during the last years. Mold filling is one of the most important steps for casting engineers which should be controlled to have a sound part. In the semisolid alloy forming die design, viscosity variations during forming and temperature decreasing, solid fraction plus globularity are the main parameters which affect final product. In this study, a stepped die was designed and some billets in different weights were injected into the die. This process helps to characterize the flow pattern during mold filling. The effect of two phase flow was also studied by microstructural investigating. Numerical simulation is the second method which is used in this study. The ProCast software was used to indicate the flow pattern of the fluid in the mold. Some comparisons were also done to show that this software is a suitable simulating software to predict the flow behavior of semisolid alloys. Also, the step casting method shows the exact pattern of flow in different parts of mold and is a reliable method for researchers to investigate the fluid pattern.
Investigation of Semi-Solid Slurries Prepared by Helical Curve Duct
Authors: Wang Ming , Yang Xiang Jie , Guo Hong Min
Published: October 2012

A new method of helical curve duct (HCD) to prepare semi-solid slurry was investigated. The semi-solid slurry of A356, AZ91, Cu-2.21wt%Ca (0.45wt%Ce) alloys were prepared through this method of HCD. Comparison of the microstructures of slurry prepared through the helical curve duct with different structure parameters and process parameters are made and the effects of structure and process parameters on microstructures are analyzed. The results show that the melt is stirred effectively by flowing through the helical curve duct and the semi-solid slurry of alloys could be prepared through the helical curve duct process; Spherical microstructures of alloy slurry were obtained through controlling or adjusting the process parameters to control solidification conditions.
Experimental Study on Semi-Solid Indirect Squeeze Casting
Authors: Bao Pei Wei , Xing Shu Ming
Published: October 2012

In the Semi-Solid Processing of indirect squeeze casting, runners were needed for each part cavity. In our experiment, it was found that some of the runners were blocked, and some parts were not filling in full mold. Numerical simulation was applied to analyze this phenomenon, and the results show that it was the shell which emerged on the chamber surface that blocked the runner. Experimental results also confirmed our interpretation. Some measures have been used to correct it, such as runner design, two-layer coating, and process improvement which eliminated blocking of the runner.
On Non-Dendritic Microstructure Formation during Sand Casting of A356 Alloy
Authors: Kaskani Mehdi , Niroumand Behzad
Published: October 2012

The purpose of this study was to develop a new method for formation of non-dendritic microstructure during sand casting of aluminum alloys without any previous special processing. For this purpose, sand molds with three different types of running systems were designed. The first design included a traditional reverse tapered vertical sprue. The second design was similar to the first one except for a conical sand core placed inside the lower half portion of the sprue creating a narrow gap for the flow of the melt into the mold. In the third design, the core was fitted with metal chills. Molten A356 alloy was then cast from fully liquid state under gravity and centrifugal casting conditions in the molds and the microstructures of the castings were studied. The results showed that non-dendritic microstructure could be achieved by using the last design under low superheat temperature and centrifugal casting conditions. The findings can pave the way for small quantity production of semisolid castings in expendable molds.
Microstructure Characteristics and Semi-Solid Slurry Formation in Binary Mg-Al Alloys Produced by the RheoMetal Process
Authors: Östklint Mattias , Wessen Magnus
Published: October 2012

The RheoMetal process, previously also called the Rapid Slurry Forming process (“Rapid S”) or RSF process, is a novel method to produce high quality, cost effective, semi-solid magnesium slurries for component casting. The RheoMetal process uses an Enthalpy Exchange Material (EEM) as internal cooling to produce the slurry. Typical critical process parameters in the RheoMetal process are alloy content, stirring speed, superheat and EEM to melt ratio. In this study the effects of EEM to melt ratio and superheat on the slurry characteristics was examined for binary Mg-Al alloys in the range 5.8 - 11.2 wt % Al. Samples were quenched after slurry preparation and the microstructure was studied with respect to solid fraction and -Al grain diameter. The solid fraction increased with an increasing EEM to melt ratio for all three Al-contents investigated. Further, it was found that the solid fraction as well as the grain diameter decreased with increasing aluminium content (at constant EEM to weight ratio).
Casting Wear-Resistant Functionally Gradient Ferrous Alloys via Partial Solidification Processing
Authors: Midson Stephen , Browne David J.
Published: October 2012

The CDC (Cast-Decant-Cast) Process is novel semi-solid processing method for joining two alloys, allowing the production of components from two or more alloys. The process produces a functionally gradient material (FGM) which, instead of having a sharp interface between the two alloys, features a transition region exhibiting a smooth gradient in concentration, microstructure and properties. Functionally gradient materials provide engineers with the flexibility to design components with different material properties at different locations. The details of the CDC Process are described. This paper, for the first time, provides information regarding the fabrication of functionally gradient castings from steels, cast irons and cobalt alloys. The first example involves the production of functionally gradient castings from a Ni-Hard cast iron + mild steel. The second example describes the production of functionally gradient castings from Stellite + mild steel. Processing parameters are documented and microstructures of the castings described.
Extremely Light Weight Rheocast Components for Automotive Space Frame
Authors: Rosso Mario , Peter Ildiko , Chiarmetta Gianluigi , Gattelli Ivano
Published: October 2012

This paper presents an analysis of a new rheocasting process suitable for the manufacturing of high performance automotive parts. The process is able for the realization of components using Al alloys. An important aspect is related to the possibility to obtain quite wide range of thicknesses, starting from 2.5 mm. The used alloy is the well known A356, with low Fe content, maximum 0.08 wt%. T6 heat treatments has been performed, while the soundness of the parts has been certified by non destructive tests. These parts are produced to be mounted on a top level and famous sport car. Non standard samples for mechanical tests have been machined directly from the components. Following the mechanical tests fracture surface analysis has been carried out by SEM to observe some morphological details and to evaluate the influence of the process and of the alloy conditions on the fracture behaviour. On the polished transverse sections of the samples morphological analysis has been performed. The obtained results shown high level of mechanical strength for all series of components. The reliability of the process is very high at a convenient level of manufacturing rate. The weldability of the parts has been demonstrated.
Mechanical Properties of Hypo/Hyper-Eutectic Al-Si Bi-Metal Composite Parts Prepared by Thixo-Forging
Authors: Li Tian Bao , Yang Zhao , Li Bing , Ye Yu Long
Published: October 2012

Hypo/hyper-eutectic Al-Si bi-metal composite parts were prepared by the strain-induced melt activated (SIMA) thixo-forging. The interfaces of the bi-metal composites were observed using OM, and SEM. The tensile strength and hardness of the matrix alloys and the bonding strength at the interface were assessed by tensile test and micro-indent test. Results show that the eutectic structure joined together on the interface under the pressure. However, there are some defects such as holes and impurities were found near the interface. The tensile test samples were broken in Al-20 wt. % Si matrix. The bonding strengths at the interfaces were higher than 80 MPa. Results show that the hardness gradually increasing from 55 HV in Al-7 wt. % Si alloy to 180 HV in Al-20 wt. % Si alloy, which demonstrate the composite interface transited smoothly. The composite interface has an average hardness of 80 HV.
Abl Family Kinases Regulate FcγR-Mediated Phagocytosis in Murine Macrophages
Authors: Greuber Emileigh K. , Pendergast Ann Marie
Published: October 2012

Phagocytosis of Ab-coated pathogens is mediated through FcγRs, which activate intracellular signaling pathways to drive actin cytoskeletal rearrangements. Abl and Arg define a family of nonreceptor tyrosine kinases that regulate actin-dependent processes in a variety of cell types, including those important in the adaptive immune response. Using pharmacological inhibition as well as dominant negative and knockout approaches, we demonstrate a role for the Abl family kinases in phagocytosis by macrophages and define a mechanism whereby Abl kinases regulate this process. Bone marrow–derived macrophages from mice lacking Abl and Arg kinases exhibit inefficient phagocytosis of sheep erythrocytes and zymosan particles. Treatment with the Abl kinase inhibitors imatinib and GNF-2 or overexpression of kinase-inactive forms of the Abl family kinases also impairs particle internalization in murine macrophages, indicating Abl kinase activity is required for efficient phagocytosis. Further, Arg kinase is present at the phagocytic cup, and Abl family kinases are activated by FcγR engagement. The regulation of phagocytosis by Abl family kinases is mediated in part by the spleen tyrosine kinase (Syk). Loss of Abl and Arg expression or treatment with Abl inhibitors reduced Syk phosphorylation in response to FcγR ligation. The link between Abl family kinases and Syk may be direct, as purified Arg kinase phosphorylates Syk in vitro. Further, overexpression of membrane-targeted Syk in cells treated with Abl kinase inhibitors partially rescues the impairment in phagocytosis. Together, these findings reveal that Abl family kinases control the efficiency of phagocytosis in part through the regulation of Syk function.
ATP-Binding Cassette Transporter G1 Intrinsically Regulates Invariant NKT Cell Development
Authors: Sag Duygu , Wingender Gerhard , Nowyhed Heba , Wu Runpei , Gebre Abraham K. , Parks John S. , Kronenberg Mitchell , Hedrick Catherine C.
Published: October 2012

ATP-binding cassette transporter G1 (ABCG1) plays a role in the intracellular transport of cholesterol. Invariant NKT (iNKT) cells are a subpopulation of T lymphocytes that recognize glycolipid Ags. In this study, we demonstrate that ABCG1 regulates iNKT cell development and functions in a cell-intrinsic manner. Abcg1−/− mice displayed reduced frequencies of iNKT cells in thymus and periphery. Thymic iNKT cells deficient in ABCG1 had reduced membrane lipid raft content, and showed impaired proliferation and defective maturation during the early stages of development. Moreover, we found that Abcg1−/− mice possess a higher frequency of Vβ7+ iNKT cells, suggesting alterations in iNKT cell thymic selection. Furthermore, in response to CD3ε/CD28 stimulation, Abcg1−/− thymic iNKT cells showed reduced production of IL-4 but increased production of IFN-γ. Our results demonstrate that changes in intracellular cholesterol homeostasis by ABCG1 profoundly impact iNKT cell development and function.
Identification of an MHC Class I Ligand for the Single Member of a Killer Cell Lectin-like Receptor Family, KLRH1
Authors: Daws Michael R. , Dai Ke-Zheng , Zinöcker Severin , Naper Christian , Kveberg Lise , Hedrich Hans J. , Rolstad Bent , Vaage John T.
Published: October 2012

Natural killer cells are able to recognize and kill target cells according to differences in MHC class I expression. In rodents, the Ly49 receptors are primarily responsible for this MHC differentiation. We previously described the cloning of a novel C-type lectin–like receptor, KLRH1, encoded in the NK complex adjacent to the Ly49 genes and expressed by subsets of NK and NKT cells. MHC influence on selection of KLRH1+ NK cells in congenic strains suggested that KLRH1 may have an MHC ligand, although we were unable to identify any such ligand. In this study, we have used a sensitive reporter system and Fc fusion protein to demonstrate that KLRH1 binds specifically to the classical MHC class I molecule RT1-A2 of the RT1n haplotype. Cytolytic activity of KLRH1-transfected RNK-16 cells was also inhibited by target cells expressing RT1-A2n. Thus, KLRH1 represents a novel family of MHC allele–specific inhibitory receptors expressed by NK cells.
The impact of customer knowledge capability and relational capability on new service development performance: The case of health service
Authors: Weng Rhay-Hung , Huang Ching-Yuan
Published: October 2012

This study intends to explore the impact of the customer knowledge integration capability, customer knowledge absorptive capability, customer knowledge creation capability, and customer relationship capability on new service development (NSD) performance for Taiwan's hospitals from customer knowledge and customer relationship perspectives. We employ the self-administered mail survey to collect research data and select self-pay medical service managers or top managers as key informants. After testing the fitness of sample representativeness, non-response error, common method variance, reliability, and validity, we adopt structure equation model to test the research model. Empirical results indicate the customer knowledge absorptive capability of a hospital is positively associated with NSD performance, and the customer knowledge integration capability of a hospital fully mediates the relationship between customer knowledge absorptive capability and NSD performance. However, customer relationship capability and customer knowledge absorptive capability both have positive influence on customer knowledge creation capability. Managerial and theoretical implications are discussed.
Linking nurses' attitudes and behaviors to organizational values: Implications for human resource management
Authors: Cavanagh Jillian , Fisher Ron , Francis Mark , Gapp Rod
Published: October 2012

The researchers use established measures of job satisfaction (JS) and organizational citizenship behavior (OCB) to analyze data obtained from nurses in an Australian hospital (N = 573), and to discuss implications for human resource management. In this study the researchers seek to understand the links between nurses' JS, OCB and their perceptions of the values espoused by the organization. Changes in JS and OCB as length of service increases are also examined. Findings suggest that JS and OCB are both significant predictors of nurses' perceptions of organizational values. The findings also suggest that nurses more readily internalize organizational values when levels of JS and OCB are high. A further finding is that the tendency to engage in OCB declines significantly as length of service increases.
Strategic human resources management for dental clinics in South Korea
Authors: Kim Yong-Tae , Hwang Yeo-Im
Published: October 2012

This study was conducted to verify the relationship between organizational cultural types, social capital and organizational effectiveness in South Korean dental clinics. The findings suggest that consensual culture is the best fit with social capital. Also, high level of organizational identification, trust and cohesiveness increases job satisfaction and lowers turnover intention. If applying the results practically, organizational identification, improvement of welfare system, stress control, and coaching program for personal development are the most optimal solution.
Employee perceptions of workforce retention strategies in a health system
Authors: Belbin Cheryl , Erwee Ronel , Wiesner Retha
Published: October 2012

This quantitative study explores the perceptions of 379 nurses using a survey to assess awareness of, participation in, and effectiveness of 28 workforce retention strategies offered by Queensland Health. Perceptions of workforce retention strategies were also examined to determine if any aspects of the strategy (retention factors) had an influence on turnover intention. The major findings were that respondents were more aware and had participated to a greater extent in those strategies that were included in Queensland Health policy or were part of the nursing Enterprise Bargaining Agreement. Strategies ranked as most effective included those that provided a monetary advantage and to a lesser extent, a professional development opportunity. A positive relationship was found between retention factors and decreased turnover intention.
Columnar aerosol properties from sun-and-star photometry: statistical comparisons and day-to-night dynamic
Authors: Pérez-Ramírez D. , Lyamani H. , Olmo F. J. , Whiteman D. N. , Alados-Arboledas L.
Published: October 2012

Abstract. This work presents the first analysis of long-term correlative day-to-night columnar aerosol optical properties. The aim is to better understand columnar aerosol dynamic from ground-based observations, which are poorly studied until now. To this end we have used a combination of sun-and-star photometry measurements acquired in the city of Granada (37.16° N, 3.60° W, 680 m a.s.l.; South-East of Spain) from 2007 to 2010. For the whole study period, mean aerosol optical depth (AOD) around 440 nm (± standard deviation) is 0.18 ± 0.10 and 0.19 ± 0.11 for daytime and nighttime, respectively, while the mean Angström exponent (α) is 1.0 ± 0.4 and 0.9 ± 0.4 for daytime and nighttime. The ANOVA statistical tests reveal that there are no significant differences between AOD and α obtained at daytime and those at nighttime. Additionally, the mean daytime values of AOD and α obtained during this study period are coherent with the values obtained in the surrounding AERONET stations. On the other hand, AOD around 440 nm present evident seasonal patterns characterised by large values in summer (mean value of 0.20 ± 0.10 both at daytime and nighttime) and low values in winter (mean value of 0.15 ± 0.09 at daytime and 0.17 ± 0.10 at nighttime). The Angström exponents also present seasonal patterns, but with low values in summer (mean values of 0.8 ± 0.4 and 0.9 ± 0.4 at day- and night-time) and relatively large values in winter (mean values of 1.2 ± 0.4 and 1.0 ± 0.3 at daytime and nighttime). These seasonal patterns are explained by the differences in the meteorological conditions and by the differences in the strength of the aerosol sources. To take more insight about the changes in aerosol particles between day and night, the spectral differences of the Angström exponent as function of the Angström exponent are also studied. These analyses reveal increases of the fine mode radius and of the fine mode contribution to AOD during nighttime, being more remarkable in the summer seasons. These variations are explained by the changes of the local aerosol sources and by the meteorological conditions between daytime and nighttime, as well as aerosol aging processes. Case studies during summer and winter for different aerosol loads and types are also presented to clearly illustrate these findings.
Assessing Reproducibility for Radiographic Measurement of Leg Length Inequality after Total Hip Replacement
Authors: McWilliams Anthony B. , Grainger Andrew J. , O'Connor Philip J. , Redmond Anthony C. , Stewart Todd D. , Stone Martin H.
Published: October 2012

Leg length inequality (LLI) as a result of total hip replacement can cause considerable morbidity. Although LLI was described when the technique was popularised in the 1960s, it remains a significant challenge to arthroplasty surgeons. This study reviews the established practice for the measurement of LLI on plain antero-posterior radiograph, and compares these techniques to two methods used locally. The radiographs of 35 patients were measured using four techniques. All four methods yielded an interclass correlation co-efficient of ≥0.90 for inter reader reliability. This study shows that the four methods are comparable for reliability, while a composite method, measuring from the centre of femoral rotation to the inferior teardrop and then to the lesser trochanter, has the added advantage of providing extra information on component position as well as an overall measure of LLI.
Interaction of Ethanol Vapour with Silane-Modified Surface of Corning Porous Glass CPG-10
Authors: Nadiye-Tabbiruka Misael Silas
Published: October 2012

The interaction of ethanol vapour at 293 K with modified Corning controlled porous glass (CPG-10) samples of various pre-silylation is reported. Ethanol adsorption on CPG-10 was greatly reduced by silylation to extents largely depending on the silylation extent, type of silane used, and on the concentration and accessibility of residual silanols. The obtained adsorption isotherms, BET surface areas, as well as the observed changes at the various stages during the sorption particularly in the capillary condensation region also showed similar dependence. In the capillary condensation region, in the case of the dimethyl dichlorosilane-modified sample, hysteresis type was changed from H3 to H1. On the triethyl chlorosilane-modified sample an unexpected suppression of hysteresis effects occurred with a consequent transformation of type IV to type II adsorption isotherm.
Doing Ethnography with Child Consultants: Making the IRB Process Work
Authors: Ridgely Susan B.
Published: October 2012

Drawing on my work in Catholic parishes and evangelical Christian homes and churches, as well as conversations with other scholars, I will share some lessons I learned about the Institutional Review Board (IRB) process and review how I have handled issues of consent and privacy concerns that have arisen in that process from 1996 through 2012. While no one can offer a how-to guide, I hope to demonstrate that as the National Institutes of Health’s (NIH) stance on using children in research has evolved, it has provided local IRBs with tools to encourage research with children rather than simply enforcing restrictive regulations. In so doing, I hope to encourage more scholars to submit proposals for work with children, since each proposal serves to increase IRB panels’ awareness of child-centered qualitative research.
Effect of Antioxidants on the Lipid Oxidation and Flavor of Microwave-assistant Dried Silver Carp (Hypophthalmichthys molitrix) Slices
Authors: Fu Xiangjin , Li Zhonghai , Lin Qinglu , Xu Shiying
Published: October 2012

Silver carp slices were dried using microwave, and the effect of vitamin C (VC) and tea polyphenols (TP) on the quality of the dried fish slices were evaluated. The lipid oxidation, flavor, and content of fat, eicosapentaenoic (EPA), docosahexaenoic acid (DHA), earthy-musty off-odor compounds were compared among the dried slices. Marinating with VC and TP significantly protected the lipid from oxidation. Samples treated with TP (0.2 g/100 mL) retained the most of DHA and EPA, while restricting fishy off-odors. About 50% of geosmin and 70% of 2-methylisoborneol, the earthy-musty off-odor compounds, were removed by marinating with VC (0.4 g/100 mL) combined with microwave drying.
Configuration Synthesis for Fully Restrained 7-Cable-Driven Manipulators
Authors: Tang Xiaoqiang , Tang Lewei , Wang Jinsong , Sun Dengfeng
Published: October 2012

Cable distribution plays a vital role in Cable Driven Parallel Manipulators (CDPMs) regarding tension and workspace quality, especially in fully restrained CDPMs. This paper focuses on three typical configurations of fully restrained CDPMs with 7 cables in order to introduce an approach for configuration synthesis. Firstly, the kinematic models of three types of CDPMs with 7 cables are set up. Then, in order to evaluate workspace quality, two new indices are proposed by using tensions along each cable, which are the All Cable Tension Distribution Index (ACTDI) and Global Tension Distribution Index (GTDI). Next, the three types of CDPMs with 7 cables are analysed with the two indices. At the end, according to different performance requirements, the configurations of cable distribution are discussed and selected.
Design on the Control System of a Gait Rehabilitation Training Robot Based on Brain-Computer Interface and Virtual Reality Technology
Authors: Wang Hui , Song Quanjun , Zhang Leijie , Liu Yongjiu
Published: October 2012

In this paper a control system of a gait rehabilitation training robot based on Brain-Computer Interface (BCI) and virtual reality technology is proposed, which makes the patients' rehabilitation training process more interesting. A technique for measuring the mental states of the human and associated applications based on normal brain signals are examined and evaluated firstly. Secondly, the virtual game starts with the information from the BCI and then it runs in the form of a thread, with the singleton design pattern as the main mode. Thirdly, through the synergistic cooperation with the main software, the virtual game can achieve quick and effective access to blood oxygen, heart rate and other physiological information of the patients. At the same time, by means of the hardware control system, the start-up of the gait rehabilitation training robot could be controlled accurately and effectively. Therefore, the plantar pressure information and the velocity information, together with the physiological information of the patients, would be properly reflected in the game lastly and the physical condition of the patients participating in rehabilitation training would also be reflected to a great extent.
Present and future of anaesthesiology
Authors: Mellin-Olsen Jannicke
Published: October 2012

The aim of the European Union of Medical Specialists is to improve and harmonise training and free movement of medical specialists in Europe. The training of European anaesthesiologists varies across country borders. The Section and Board of Anaesthesiology has chaired the development of new training guidelines and curriculum which will serve to make the training more uniform. We have also been pioneers in patient safety and in developing our specialty with its various areas of competence. We need to take charge of our own future, also when it comes to manpower and medical development.
Anesthetizing children: little people, big problems!
Authors: Lerman Jerrold
Published: October 2012

At the time of graduation from residency, we possess the most knowledge of anesthesia than at any other time in our lives. Dr. S. Burwell, Dean of the Harvard Medical School, said in 1956: “Half of what you are taught as medical students will in 10 years have been shown to be wrong. And the trouble is none of your teachers know which half ”. Our understanding of the etiology and pathogenesis of many of the “big problems” that children present may lead to better outcomes and better quality of care, and it is the quintessential proposition for the delivery of excellence in clinical care to these “little people”. In this lecture we review a number of contentious and controversial issues that face pediatric anesthesiologists on a daily basis and present practical, evidence based approaches to addressing them.
Outline of recent developments in CPR for children
Authors: Turner Nigel
Published: October 2012

Cardiac arrest in children is more often due to hypoxaemia or circulatory shock, which may have been present for some time, than to cardiac causes (1). As a result, significant organ damage has already occurred by the time of circulatory collapse and survival is generally poor. Survival with a good neurological outcome from out-of-hospital arrest in children varies from 0–12% but outcomes of up to 25% of patients have been reported from in-hospital arrest of mixed aetiology (2). Perioperative cardiac arrest in paediatric cardiac surgical patients has a higher survival.
Coagulation tests and their association with postoperative blood loss after cardiac surgery with cardiopulmonary bypass
Authors: Ozolina Agnese , Strike Eva , Sondore Antonina , Vanags Indulis
Published: October 2012

Background. Platelet count (PLT), activated partial thromboplastin time (APTT), prothrombin time (PT) and fibrinogen are standard coagulation tests used for patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). Materials and methods. 83 adult cardiac surgery patients were en­ rolled into a prospective study. Blood samples for APTT, PT, PLT, fibrino­ gen were collected preoperatively (T0), on admission to the intensive care unit (T1), 6 and 24 hours postoperatively (T6, T24). 24-hour postopera­ tive blood loss (24h-PBL) was registered. Results. The highest APTT mean value was 47  ±  13 sec at T6, in­ creasing from the baseline by 37%. The lowest mean value of PLT was 140 ± 47 × 109/L at T24, decreasing from the baseline by 32.5%. PT and fibrinogen mean values at all time points were within the normal range. Correlation with 24h-PBL was shown by T0 and T6 fibrinogen (r = –0.5, r  =  –0.4, P
Oximetry of the brain
Authors: Vilkė Alina , Macas Andrius , Bieliauskaitė Dalia , Bilskienė Diana , Šuškevičienė Ilona , Rugytė Danguolė , Tamašauskas Arimantas
Published: October 2012

Background. Devices allowing direct assessment of brain tissue oxygenation have showed promising results in clinical studies. However, estimation of brain oximetry still has some challenges. The aim of our study was to estimate the feasibility to monitor cerebral oximetry for neurosurgery patients in the Operating Room and in the Neurosurgery Intensive Care Unit, possible basic disturbances for the study and early results. Materials and methods. The prospective trial took place in a tertiary university setting – the Neurosurgery Department of the Lithuanian University of Health Sciences Hospital (Kaunas Clinics). The monitoring was performed with an INVOS® Cerebral / Somatic Oximeter, which is based on near-infrared spectroscopy. The monitoring places were the Operating Room, later the Neurosurgery Intensive Care Unit and for some patients the regular Neurosurgery Ward. All patients had acute open or closed traumatic brain injury and had undergone neurosurgery. Results. 52 patients were included in the study, while 36 operations were performed after traumatic brain injury with successful monitoring. Preoperatively GCS ranged from 3 to 15 (average 10.2 ± 4.6), all patients had no hypotension ranged from 214 mmHg to 112 mmHg (average 148.0 ± 26.6), the mean arterial pressure ranged from 155 mmHg to 61 mmHg (average 106.0 ± 21.8), only two patients had hypoxia with SpO2 of 86% and 76%, other values averaged 96.7% ± 4.3% . Hemoglobin preoperatively ranged from 162 g/l to 82 g/l (average 133.7 ± 17.9). The va­ lues of cerebral oxygenation preoperatively in the Operating Room were 42–96% (average 74.8 ± 10.8), and one patient with cerebral oxy­ genation of 15% bilaterally before surgery died in 24 hours after the surgery (normal values vary from 58 to 82%). The values varied from to 15–95% in the period of the operation. The biggest difference of cerebral oxygenation between brain hemispheres was registered as 42% and 68% before the intubation, 60% (±8.8) and 76% (±4.0) during the operation, 64% (±4.9) and 80% (±5.3) in the Intensive Care Unit. 13 patients died, 17 were discharged with GCS of 13–15 and 6 patients with GCS of 8–12. Conclusions. Monitoring of regional cerebral oximetry for neurosurgery patients can be performed, despite of its limitations: surgery or application of the Mayfield holder in the frontal region of the head, intra­ operative transcranial Doppler monitoring
Sedation in the post-anaesthesia care unit
Authors: Macas Andrius , Andriuškevičiūtė Lina , Paltanavičiūtė Jūratė , Slauzgalvytė Ieva
Published: October 2012

Background. Post-anaesthetic sedation is a common practice as it pro­ vides greater comfort and psychological stability for patients. Some spe­ cialists claim that sedation in the post-anaesthetic care unit (PACU) is applied too seldom due to several reasons. The goal of this study is to evaluate sedation in PACU in several aspects. Materials and methods. A total of 299 patients admitted to the PACU after general, orthopedic-traumatologic or urologic surgical procedures were enrolled in this prospective study. The patients evaluated their qual­ ity of sleep and the worst intensity of pain experienced in PACU, which was assessed using the Numerical Rating Scale. Nurses evaluated sedation using the Motor Activity Assessment Scale and filled in the questionnaire about the importance of sedation. Results. Statistically significant difference was observed in the quality of sleep between the patients sedated using benzodiazepines and opioids together and non-sedated patients (p = 0.025). There is no considerable difference in the statistics concerning the behavior of the patients. The patients prescribed only with opioids IV or IM, as well as the patients prescribed with opioids together with benzodiazepines, feel less intense pain compared to the non-sedated patients (p = 0.016, p = 0.03). Accord­ ing to the personnel, sedation is necessary in PACU. Half of them think that patients prescribed with opioids need additional sedation. Conclusions. Sedation is necessary in PACU. This fact is evident in the statistically significant difference of comfort factors among the patients as well as in the opinion of the nursing personnel that spend most of the time communicating and caring about the comfort of the patients.
Lung recruitment in ARDS patients
Authors: Arnal Jean-Michel , Garnero Aude
Published: October 2012

Lung recruitment is used to improve oxygenation and decrease the risk of ventilator induced lung injuries. Assessing the potential of recruitability is a pre-requisite for a rational recruitment strategy and setting of PEEP. Using a low flow pressure-volume loop is helpful to assess the potential of recruitability at the bedside. For patients with a high potential of recruitability, recruitment maneuvers are efficient with an appropriate setting of PEEP to maintain the lung recruited. Recruitment maneuvers use pressures from 40 to 60 cmH2O for a short period of time, either with the sustained inflation or the staircase method. PEEP setting after the maneuver is important; a decreasing PEEP trial is a useful practical method.
Acute heart failure: vasoactive agents – does it matter?
Authors: Macas A. , Zinkevičiūtė-Žarskienė G.
Published: October 2012

Acute heart failure (AHF) is defined as the rapid onset of symptoms se­ condary to abnormal cardiac function. It is a syndrome and has a va­ riety of potential etiologies. AHF is a very polymorphic conception and can be related with abnormalities in cardiac rhythm, systolic or diastolic dysfunction or preload and afterload mismatch. The cornerstone of ma­ nagement includes therapy directed towards the underlying cause of heart failure. On the other hand, if the underlying cause is irreversible  –  a heart assist device or even heart transplantation may be needed. Therefore, while awaiting their availability, vital organ perfusion remains crucial. In these settings, intravenous cardio-/vaso- active agents are necessary. With few exceptions, most vasopressor and positive inotropic agents are symphatomimetic amines that exert their action by binding and sti­ mulating adrenergic receptors. They are powerful drugs with a considerable potential for toxicity. Vasopressor and inotropic support in case of AHF helps to win the time until a more definitive treatment becomes available. Therefore, AHF management must be directed to establish and eliminate deteriorational factors, however, not the correction of particular hemodynamic parameters.
Administration of midazolam as sedative premedication for paediatric patients
Authors: Kalibatienė Lina , Macas Andrius , Lukošienė Laura , Ragaišis Vytautas , Kubilius Ričardas
Published: October 2012

The paper aims to discuss effective presurgical modalities for reducing preanesthetic and preoperative anxiety in children. It reviews the existing research on psychological interventions and sedative premedication for presurgical anxiety management. Psychological and behavioural pre­ operative preparation of children, through presurgical preparation programs, combined with parental presence during induction of anaesthesia are regarded as alternatives to sedative premedication. A combination of these preparation strategies with midazolam premedication is presented as an effective way of helping children cope with preanesthetic and pre­ operative anxiety. It is highlighted that the use of low dose midazolam is sufficiently safe and beneficial if alternatives to sedative premedication prove ineffective, especially when dealing with increased feelings of anxiety immediately before anesthesia and the surgery.
Agir comunicativo e planejamento social: uma crítica ao enfoque estratégico
Authors: Rivera Francisco Javier Uribe
Published: October 2012

Estudo teórico, de natureza comparativo-contrastante, abordando a lógica do planejamento estratégico no setor social e da saúde à luz da teoria do agir comunicativo de Jürgen Habermas. Na verdade, trata-se de uma 'crítica da crítica', na medida em que são problematizados os enfoques metodológicos tomados, até o momento, como referencial teórico alternativo ao planejamento normativo. A partir da teoria da ação habermasiana, o autor consegue indicações importantes para uma (re)leitura da teoria organizacional, na perspectiva de uma abordagem comunicativa entre todos os atores envolvidos nas organizações de saúde.
Agonia da fome
Authors: Freitas Maria do Carmo Soares de
Published: October 2012

Tendo como tema central o fato de que a fome crônica não se manifesta apenas como problema social ou biomédico, esta obra se dedica ao estudo etnográfico da fome e sua relevância histórica e cada vez mais atual no contexto nacional. Sob uma ótica diferenciada, a autora denuncia os modos extremos de viver e de morrer dos famintos em uma comunidade pobre de Salvador. Formulado a partir de pesquisa de campo, com narrativas reveladoras de um universo repleto de alegorias da miséria, constitui trabalho pioneiro no que tange à fenomenologia da fome, onde se descortinam, minuciosamente, os diferentes significados atribuídos a ela por aqueles que vivem sob constante ameaça de não ter o que comer. Para além de um trabalho de simples denúncia, este livro é certamente uma importante contribuição à análise sociocultural do fenômeno da fome no País.
The 1909 North Carolina Drainage Act and Agricultural Drainage Effects in Eastern North Carolina
Authors: O'Driscoll Michael A.
Published: October 2012

Over the last two centuries, agricultural drainage in eastern North Carolina has transformed extensive wetlands to productive croplands. At the start of the drainage movement in the early 1900s, approximately 200,000 hectares (one half million acres) of drained agricultural lands existed in North Carolina. The 1909 North Carolina Drainage Act allowed for more extensive drainage projects. Drainage districts provided effective drainage outlets for farms and reduced flooding for the district. The districts dramatically increased the extent of drained lands during the 20th century. Currently, it is estimated that over 2 million hectares (five million acres) of drained agricultural lands exist in North Carolina, with the majority in the Coastal Plain. Agricultural drainage has contributed to huge gains in agricultural productivity in the region. However, this drainage has contributed to regional stream water quality impairment, altered stream hydrology, and wetland conversion. Over the last three decades, much work has been focused on reducing watershed nutrient exports in eastern North Carolina. Several major strategies have been used to decrease the environmental impacts of agricultural drainage, including: agronomic management practices; controlled drainage; riparian and wetland buffers; and channel alterations. Management of agricultural drainage during the 21st century will play a crucial role in regional stream, wetland, and coastal ecosystem health.
Hybrid Endarterectomy and Endovascular Therapy in Multilevel Lower Extremity Arterial Disease Involving the Femoral Artery Bifurcation
Authors: Zou Junjie , Xia Yongxiang , Yang Hongyu , Ma Hao , Zhang Xiwei
Published: October 2012

The objective of this study was to evaluate the feasibility and efficacy of hybrid therapy (combined endarterectomy-endovascular) in patients with complex peripheral multifocal steno-obstructive vascular disease involving the femoral artery bifurcation. Forty-one combined procedures were performed on 40 patients. Although the common femoral artery was usually treated with endarterectomy, endoluminal procedures were performed proximally in 12 patients (group 1), distally in 18 patients (group 2), and both upward and downward in 11 patients (group 3). Patients underwent clinical assessment and ankle-brachial index measurement thereafter. Primary, assisted-primary, and secondary patency rates at 24 months were 59%, 66%, and 72%, respectively. Primary patency rates were lower in group 3 compared with groups 1 and 2 (P  =  0.015). The limb salvage rate was 86.4% at the end of the follow-up period. Hybrid procedures provide feasible and effective treatment management of selected patients with multilevel lower extremity arterial disease involving the femoral artery bifurcation.
Giant Neurofibroma in the Right Lower Limb of a 26-Year-Old Woman: Report of a Case
Authors: Zhou Jianda , Li Ming , Luo Chengqun , He Quanyong , Yin Zhaoqi , Peng Hao , Chen Zizi , Chen Jiye , Zhong Shi , Huiqing Xie
Published: October 2012

Neurofibromatosis (NF) is a genetically inherited, autosomal-dominant disease with an incidence of 1 in 3000 live births. There are two types of NF, NF 1 and NF 2, and NF 1 is the most common. This study reports on the diagnosis, treatment, and related family medical history of a rare case with NF-1 in the right lower limb.
Instrumented Outpatient Anterior Cervical Discectomy and Fusion: Is it Safe?
Authors: Sheperd Courtney S , Young William F
Published: October 2012

Anterior cervical discectomy and fusion procedures are one of the most common procedures performed in spinal surgery. Increasingly they are being performed on an outpatient basis. The primary impetus for performing procedures as an outpatient is potential cost savings. However, there are few studies discussing the safety of performing the procedure in an ambulatory setting. This is a retrospective review of our initial experience in performing anterior cervical discectomy and fusion procedures with instrumentation (ACDFI) in an ambulatory surgery center dedicated to spine surgery. Patients were selected for outpatient surgery if they had limited co-morbidities and the surgery involved only 1 or 2 levels. One hundred fifty-two patients underwent outpatient ACDFI during the study period (2007–2009). Six patients returned to the hospital emergency room after discharge. The reasons for evaluation included 2 for neck pain, 1 for dysphagia, 1 for vocal cord paralysis and dysphagia, 1 for nausea, and 1 for cervical swelling. Only 1 of the 6 patients required admission to the hospital. None of the 6 suffered any long-term sequelae. The overall complication rate was 3.9%. A self-reported survey was completed by 75 patients within 6 months of surgery, and there was a 100% satisfaction rate among responders. ACDFI can be performed safely on an outpatient in selected patients with a high degree of patient satisfaction. Our experience is consistent with those of previous investigators.
Three-Dimensional Stereoscopic Volume Rendering of Malignant Pleural Mesothelioma
Authors: Mollberg Nathan M , Parsad Nigel M , Armato Samuel G , Vigneswaran Janani , Kindler Hedy L , Sensakovic William F , Salgia Ravi , Silverstein Jonathan C , Vigneswaran Wickii T
Published: October 2012

Our objective was to investigate the application of three-dimensional (3D) stereoscopic volume rendering with perceptual colorization on preoperative imaging for malignant pleural mesothelioma. At present, we have prospectively enrolled 6 patients being considered for resection of malignant pleural mesothelioma that have undergone a multidetector-row computed tomography (CT) scan of the chest. The CT data sets were volume rendered without preprocessing. The resultant 3D rendering was displayed stereoscopically and used to provide information regarding tumor extent, morphology, and anatomic involvement. To demonstrate this technique, this information was compared with the corresponding two-dimensional CT grayscale axial images from two of these patients. Three-dimensional stereoscopic reconstructions of the CT data sets provided detailed information regarding the local extent of tumor that could be used for preoperative surgical planning. Three-dimensional stereoscopic volume rendering for malignant pleural mesothelioma is a novel approach. Combined with our innovative perceptual colorization algorithm, stereoscopic volumetric analysis potentially allows for the accurate determination of the extent of pleural mesothelioma with results difficult to duplicate using grayscale, multiplanar CT images.
Usefulness of Steroid Administration for Diagnosis of IgG4-Related Sclerosing Cholangitis
Authors: Kubo Norio , Suzuki Hideki , Kobayashi Tsutomu , Araki Kenichiro , Sasaki Shigeru , Wada Wataru , Kuwano Hiroyuki
Published: October 2012

Immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) is one of the IgG4-related systemic sclerosing diseases and responds well to steroid therapy. A 58-year-old male was admitted with hilar bile duct stenosis revealed by computed tomography. We performed percutaneous transhepatic right portal vein embolization (PTPE) and scheduled a right hepatectomy because a hilar cholangiocarcinoma was first suspected. However, there was no cytologic evidence of malignancy and serum IgG4 was elevated. Steroid therapy was initiated after PTPE. There was no evidence of bile duct stenosis after 4 weeks. Improving diagnostic technique, IgG4-SC was diagnosed and treated with steroid therapy. In some cases, we couldn't deny the malignancy and performed unnecessary resection. We recommend that steroid administration while waiting for the liver volume to increase after PTPE is useful. The therapy aids in the diagnosis of bile duct stenosis, which has value for a hilar bile duct limit type of IgG4-SC, as in the case reported here.
Cost Analysis of Establishing a Relationship Between a Surgical Program in the US and Vietnam
Authors: Chu Quyen D. , Nguyen Thu , Nguyen Phuong , Ho Hung S.
Published: October 2012

“Twinning” refers to a constructive partnership between hospitals in developed and developing nations. Such an effort may contribute immensely to capacity building for the developing nation, but one of the reasons given for the lack of sustainability is cost. We share a detailed operating cost analysis of our recent experience with an institution in Vietnam. We were awarded a 1-year $54,000 grant from the Vietnam Education Foundation (VEF) to conduct a live tele-video conferencing course on the “Fundamentals of Clinical Surgery” with Thai Binh Medical University (TBMU). In-country lectures as well as an assessment of the needs at TBMU were performed. Total financial assistance and expenditures were tabulated to assess up-front infrastructure investment and annual cost required to sustain the program. The total amount of direct money ($66,686) and in-kind services ($70,276) was $136,962. The initial infrastructure cost was $41,085, which represented 62% of the direct money received. The annual cost to sustain the program was approximately $11,948. We concluded that the annual cost to maintain a “twinning” program was relatively low, and the efforts to sustain a “twinning” program were financially feasible and worthwhile endeavors. “Twinning” should be a critical part of the surgical humanitarian volunteerism effort.