bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of Impurity Diffusion Coefficients in a Single Experimental Cycle
Authors: Engelhardt Hannes , Rettenmayr Markus
Published: May 2014

An experimental approach employing temperature and concentration gradients is presented that is suitable for determining impurity diffusion coefficients in a single experimental cycle. The Al-Cu system is used to illustrate the feasibility of the method. In a single phase α-Al solid solution, concentration gradients are generated by exposing a cylindrical sample to steep temperature gradients and by annealing until the initially formed mushy zone is re-solidified. The annealing is performed such that a symmetric, ramp shaped profile in the form of a roof is generated. The sample is then again exposed to a temperature gradient at somewhat lower temperatures for an extended time period. The symmetric profile then becomes asymmetric due to the varying diffusion coefficient along the sample. Information on the pre-exponential factor D0 and the activation energy for diffusion QD is retrieved from the asymmetry of the resulting concentration profile. The asymmetry becomes increasingly pronounced with longer diffusion times, yielding an increasing accuracy of the diffusion coefficients. The experimental approach is generally applicable to alloy systems with finite solubility.
Analysis of the Effect of Cooling Rate on Microstructure in 17% Cr Ferritic Cast Steel
Authors: Parti József , Mertinger Valéria
Published: May 2014

High Cr and Ni content steels are widely used in many manufacturing processes in the chemical and petrochemical industry. The automotive industry has also recognized the necessity of heat resistant alloys for a long time, for example, to apply them to exhaust systems to endure thermal loading and oxidation during the operation of engines. Various heat resistant alloys such as cast irons, stainless steels, and Ni-base super alloys have been considered as candidate materials of automotive exhaust systems. Among those candidates, ferritic stainless steels attracted a lot of attention due to their favorable low thermal expansion, sufficient mechanical strength at elevated temperature and excellent corrosion resistant properties [1]. Currently they are the leading engineering materials in several fields of applications that require resistance to wear, corrosion [2,3], creep or thermal fatigue [4]. The high corrosion resistance of these steels is due to alloying elements such as Cr, Ni and Mo. If the ferritic stainless steels are alloyed with strong carbide-forming elements, such as Mo, Ti, V and Nb, hard phases, MC carbides can be obtained in the soft ferrite phase [5,6]. The improvement of the properties of FeCrNi cast steels is directly related to the development of the microstructure, which mainly consists of a ferritic matrix and carbides and/or dispersed intermetallics [7,8]. The improvement is not always the hardening. The hardness is usually limited by the casting and the subsequent machining, so an annealing process is also inserted.
In Situ Investigation of Grain Migration by TGZM during Solidification in a Temperature Gradient
Authors: Reinhart Guillaume , Nguyen-Thi Henri , Sarpi Brice , Bogno Aboul Aziz , Billia Bernard
Published: May 2014

Temperature Gradient Zone Melting (TGZM) occurs when a liquidsolid zone is submitted to a temperature gradient and leads to the migration of liquid droplets or channels through the solid, up the temperature gradient. TGZM has a major influence on the preparation of the initial solid-liquid interface during the stabilization phase following the directional melting of an alloy and is at the origin of the diffusion of solute towards the top part of the mushy zone. TGZM is also causing the migration up the temperature gradient of dendrite secondary arms during directional solidification, which can have a significant impact on the micro-segregation pattern of the final microstructure. In this communication we report on a directional solidification experiment carried out at the European Synchrotron Radiation Facility (ESRF) in Grenoble (France) on Al4.0 wt.% Cu alloy to study the dynamics induced by the TGZM phenomenon on an equiaxed grain that nucleated in front of a columnar structure. Based onin situexperimental observations obtained by synchrotron X-ray radiography, the dissolution of the bottom part of the equiaxed grain is characterized and measurements are compared with predictions of the TGZM theory in diffusive regime.
Evaluation of (Al)-Si Eutectic Reference Temperature of A3xx Alloys
Authors: Ferdian Deni , Lacaze Jacques
Published: May 2014

The modification level of Al-Si alloys is generally evaluated by the depression of the (Al)-Si eutectic temperature which can be recorded by thermal analysis. However, this method requires a reference temperature which should be the eutectic temperature evaluated on the relevant phase diagram. Various methods proposed to account for the effect of low level alloying elements on this reference temperature are reviewed and emphasis is put on the so-called Mondolfo's equation which is updated. Predictions are compared to experimental information from literature.
Amorphization of CuZr Based Alloy Powders by Mechanical Milling
Authors: Tomolya Kinga , Janovszky Dóra , Sycheva Anna
Published: May 2014

The effect of nickel addition was studied in the CuZr system creating alloys with near eutectic composition. Nickel and aluminum have been regarded as useful elements to improve the plasticity, thermal stability of the CuZr-based amorphous alloys. Cu49Zr45Al6and (Cu49Zr45Al6)95Ni5were selected because of the good glass-forming ability. After 15 h of milling the structure of the powders was amorphous based on the XRD analysis. By adding nickel, the crystallization temperature (Tx) shifted to higher temperatures compared to CuZrAl alloy. The value of supercooled liquid region was 64 K, which means CuZrAl has a comparatively high glass forming ability.
Numerical Study of the Influence of Diffusion-Governed Growth Kinetics of Ternary Alloy on Macrosegregation
Authors: Wu Meng Huai , Kharicha Abdellah , Ludwig Andreas
Published: May 2014

This article is to assess the modeling treatment of the growth kinetics (finite or infinite diffusion in liquid and solid phases) during solidification and its influence on the calculation of macrosegregation. A model of diffusion-governed growth kinetic for ternary alloy is developed and used for this assessment. Solidification of a 2D casting (50 x 50 mm2) of a ternary alloy (Fe-0.45 wt.% C-1.06 wt.%Mn) is considered. The result shows that finite diffusion in liquid, important for the initial stage of solidification, plays very important role in the formation of macrosegregation. Moreover, the role of the finite diffusion kinetics in the formation of macrosegregation shows differently in the two extreme cases of solidification structures (columnar or equiaxed).
Trapping Effect on the Kinetic Critical Radius in Nucleation and Growth Processes
Authors: Erdélyi Zoltán , Balogh Zoltán , Katona Gabor L. , Beke Dezső L.
Published: May 2014

The critical nucleus size—above which nuclei grow, below dissolve—during diffusion controlled nucleation in binary solid-solid phase transformation process is calculated using kinetic Monte Carlo (KMC). If atomic jumps are slower in an A-rich nucleus than in the embedding B-rich matrix, the nucleus traps the A atoms approaching its surface. It doesn’t have enough time to eject A atoms before new ones arrive, even if it would be favourable thermodynamically. In this case the critical nucleus size can be even by an order of magnitude smaller than expected from equilibrium thermodynamics or without trapping. These results were published in [Z. Erdélyi et al., Acta Mater. 58 (2010) 5639]. In a recent paper M. Leitner [M. Leitner, Acta Mater. 60 (2012) 6709] has questioned our results based on the arguments that his simulations led to different results, but he could not point out the reason for the difference. In this paper we summarize our original results and on the basis of recent KMC and kinetic mean field (KMF) simulations we show that Leitner’s conclusions are not valid and we confirm again our original results.
TLR-Induced Cytokines Promote Effective Proinflammatory Natural Th17 Cell Responses
Authors: Massot Bérangère , Michel Marie-Laure , Diem Séverine , Ohnmacht Caspar , Latour Sylvain , Dy Michel , Eberl Gérard , Leite-de-Moraes Maria C.
Published: May 2014

Naive CD4 lymphocytes undergo a polarization process in the periphery to become induced Th17 (iTh17) cells. Using retinoic acid–related orphan receptor γt (RORγt)-gfp mice, we found that RORγt and the transcription factor promyelocytic leukemia zinc finger (PLZF) are valuable new markers to identify the recently described natural Th17 (nTh17) cell population. nTh17 cells are thymically committed to promptly produce large amounts of IL-17 and IL-22. In this study, we show that, in addition to responding to TCR cross-linking, nTh17 cells secrete IL-17 and IL-22 when stimulated with IL-23 plus IL-1β, either in recombinant form or in supernatants from TLR4-activated dendritic cells. This innate-like ability of RORγt+ nTh17 cells to respond to TLR4-induced cytokines was not shared by iTh17 cells. The other distinct properties of RORγt+ nTh17 cells are their high expression of PLZF and their absence from lamina propria; iTh17 cells are found therein. RORγt+ nTh17 cells are present in the thymus of germ-free RORγt-gfp and IL-6−/− RORγt-gfp mice, indicating that these cells do not require symbiotic microbiota or IL-6 for their generation. Finally, we found that PLZF+RORγt+ nTh17 cells represent one of the primary IL-17–producing innate-like T cell populations in a TLR7 imiquimod model of psoriasis-like disorder, indicating their involvement in this kind of lesion. Collectively, our results reveal RORγt and PLZF as characteristic markers for identifying nTh17 cells and demonstrate one of their novel properties: the ability to respond promptly to TLR-dependent proinflammatory stimuli without TCR engagement, placing them as members of the innate-like T cell family.
GANP Regulates the Choice of DNA Repair Pathway by DNA-PKcs Interaction in AID-Dependent IgV Region Diversification
Authors: Eid Mohammed Mansour Abbas , Maeda Kazuhiko , Almofty Sarah Ameen , Singh Shailendra Kumar , Shimoda Mayuko , Sakaguchi Nobuo
Published: May 2014

RNA export factor germinal center–associated nuclear protein (GANP) interacts with activation-induced cytidine deaminase (AID) and shepherds it from the cytoplasm to the nucleus and toward the IgV region loci in B cells. In this study, we demonstrate a role for GANP in the repair of AID-initiated DNA damage in chicken DT40 B cells to generate IgV region diversity by gene conversion and somatic hypermutation. GANP plays a positive role in IgV region diversification of DT40 B cells in a nonhomologous end joining–proficient state. DNA-PKcs physically interacts with GANP, and this interaction is dissociated by dsDNA breaks induced by a topoisomerase II inhibitor, etoposide, or AID overexpression. GANP affects the choice of DNA repair mechanism in B cells toward homologous recombination rather than nonhomologous end joining repair. Thus, GANP presumably plays a critical role in protection of the rearranged IgV loci by favoring homologous recombination of the DNA breaks under accelerated AID recruitment.
Vires acquirit eundo
Authors: Lotz Jan
Published: May 2014

No abstract available.
New RSSA committee
Authors: Sperryn Clive
Published: May 2014

No abstract available.
Dysplastic bone disease mimicking exostoses of the ear canal
Authors: Shayah A , Gadepalli C , Loke D , Knight L C
Published: May 2014

No abstract available.
Unusual case of pulmonary valve atresia
Authors: Steyn F JS , Bellow N , Takawira F
Published: May 2014

No abstract available.
Post-traumatic cholesteatoma... a rare occurrence
Authors: Naidoo L , Nanan A
Published: May 2014

Temporal bone fractures and their acute complications have been well described in radiology and ENT journals. This is in contrast to the delayed and rare complication of implantation cholesteatomas. We present the CT findings of two cases of infiltrating cholesteatomas that developed many years following temporal bone trauma.
Advancing neuroimaging research in South Africa
Authors: Spottiswoode B S , Carey P D
Published: May 2014

No abstact available.
Radioactive News
Authors: Van Rensburg L Janse
Published: May 2014

No abstact available.
Multi-organ echinococcosis in a paediatric patient
Authors: De Witt Juruan , Stoker A F
Published: May 2014

Echinococcosis is an infection caused in humans by the larval stage of the Echinococcus parasite. Multi-organ involvement is common and cysts may develop in various organs. Radiological imaging modalities play an important role in the diagnosis, management and follow-up of echinococcosis. We present a case of multi-organ echinococcosis with extensive pulmonary involvement.
CPD questionnaire
Authors: Fani Gertrude
Published: May 2014

No abstact
Incidental MDCT finding of a subclinical PDA in an adult patient with Eisenmenger syndrome
Authors: Reddy S , Sudwarts G , Quail G , Modi M , Hendson W
Published: May 2014

N/A
Spinal segmental dysgenesis
Authors: Andronikou S
Published: May 2014

N/A
Abdominal imaging diagnosis
Authors: Misser S K
Published: May 2014

N/A
The state of academic radiology in South Africa in 2010
Authors: Lotz Jan
Published: May 2014

N/A
Is computed tomography of the brain necessary in patients with clinically suspected depressed skull fracture and no focal neurological deficit?
Authors: Rabie J A , Otto S , Le Roux A J
Published: May 2014

Objective. The objective of the study was to determine whether computed tomography (CT) of the brain is necessary in all head trauma patients with clinically suspected depressed skull fractures, Glasgow Coma Scale (GCS) scores of 13 and above, and no focal neurological deficits.

Design. A retrospective descriptive analysis was undertaken of patients of all ages who presented at the trauma unit of the Pelonomi Hospital Complex in Bloemfontein with GCS of 13 to 15, depressed skull fracture, no clinical focal neurological deficit, and who also underwent CT of the brain. Data were obtained from patients' files, and radiological reports and were analysed by the Department of Statistics, University of the Free State.

Results. One hundred and thirty-one patients were included in the study, of whom 56 (42.7%) were found to have substantial intracranial pathology as determined by CT. Twenty-four (18.3%) of these patients had a GCS of 13, of whom 6 (25%) had normal CT scans and 18 (75%) intracranial pathology. Twenty-eight (21.37%) of the 56 patients with intracranial pathology had a GCS of 14, of whom 11 (39.3%) had normal CT scans and 17 (60.7%) intracranial pathology. A GCS of 15 was determined in 79 (60.3%) of the 131 patients, of whom 58 (73.4%) had normal CT scans and 21 (26.6%) intracranial pathology.

Conclusion. Based on our findings, CT imaging of the brain in patients with a clinically suspected depressed skull fracture despite any clinical neurological deficit and a GCS of 13 or more is warranted in our setting. The likelihood of injury on CT correlated inversely with the GCS.
Multimodality imaging and interventional management of a complex congenital vascular malformation
Authors: Ahmed Aadil
Published: May 2014

Hepatic vascular lesions are not an uncommon finding in children, and represent the most common benign liver tumours to present in infancy. We present a case of a complex vascular malformation with an intrahepatic component suggestive of a venous/arteriovenous malformation as well as a large extrahepatic lesion. The extrahepatic mass was present in both sub- and supra-diaphragmatic locations ,with features of a congenital haemangioma.

In view of the clinical presentation and different imaging appearances, this case was felt to be interesting in its radiological workup, management and eventual unusual pathology.
The HPCSA and radiology
Authors: Richardson M
Published: May 2014

N/A
The dissertation generaltion
Authors: Pitcher Richard
Published: May 2014

N/A
CPD questionnaire
Authors: Fani Gertrude
Published: May 2014

CPD questionnaire
Cardiovascular Imaging in South Africa
Authors: Scholtz Leonie
Published: May 2014

Approximately 17 million people die every year from cardiovascular disease or stroke. South Africa has a very high incidence of ischemic heart disease. We have access to superb diagnostic tools that enable us to play a pivotal role in the non-invasive diagnosis of heart disease. I believe the time is ripe for renewed discussions between the role players (the RSSA, cardiologists, radiologists and the reimbursing companies) in order to elevate coronary CTA and CMR to the level where they belong: undoubtedly enormously valuable diagnostic tools which are currently shamelessly underutilized, to the detriment of many patients who have an enhanced chance of dying of a cardiovascular condition as a result of being investigated by inferior and/or invasive tests.
Experiences of using a single post-contrast CT scan of the urinary tract after triphasic contrast injection
Authors: Pretorius Phillip Carl
Published: May 2014

I was alerted to an article in Radiology Vol. 255 No. 2 (May 2010)1 by a colleague. The article, entitled ‘Kidney and urinary tract imaging: Triple-bolus multidetector CT urography as a one-stop shop – Protocol design, opacification, and image quality analysis’, clearly describes the technique, while the quotation below, from the article, summarises the findings:

‘We have shown that triple-bolus multidetector CT urography allowed visualization of renal parenchymal, excretory, and vascular contrast-enhancement phases in a single dose-efficient acquisition and provided sufficient opacification of the UUT, with simultaneous and adequate image quality of renal parenchyma and vascular anatomy.’ The main emphasis on this technique is to reduce the number of unnecessary CT scans when assessing the urinary tract. Our previous protocol for scanning the urinary tract for pathology included four phases: a pre-contrast, corticomedullary, nephrographic and delay excretory phase.
Bleomycin toxicity post injection into craniopharyngioma
Authors: Norval Ivan
Published: May 2014

Craniopharyngioma is a common suprasellar mass that is frequently encountered in radiology. These tumours are difficult to treat, with a combination of resection and radiation therapy having been the gold standard. Our case highlights a complication of a newer approach to treatment in which bleomycin is administered into the tumour via a catheter, usually an Ommaya reservoir that is surgically placed.
Paranasal sinus variants
Authors: Ebrahim Zaeem Ismail , Lockhat Zarina Ismail
Published: May 2014

Normal variations of the the paranasal sinuses tend to be overlooked but can have pathological consequences, making identification important.
Roentgenographic diagnosis of mucopolysaccharidosis with particular reference to Morquio syndrome
Authors: Parashari Umesh Chandra , Khanduri Sachin , Bhadury Samarjit , Rawat Sugandha
Published: May 2014

Mucopolysaccharidosis (MPS) comprises a group of conditions associated with an abnormality in glycoprotein or mucopolysaccharides metabolism. Types of MPS identified are MPS I-H (Hurler's syndrome, gargoylism), MPS II (Hunter's syndrome), MPS III (Sanfilippo's syndrome), MPS IV (Morquio-Brailsford syndrome), MPS I-S (Scheie's syndrome) and MPS VI (Maroteaux-Lamy syndrome). The Hunter type is inherited as an X-linked recessive; the others are autosomal recessive. Patients with MPS IV can usually be clinically distinguished from patients with other forms of MPS; their intelligence is unimpaired, in contrast with other forms of MPS. Husler coined the term dysostosis multiplex to describe the skeletal findings.
An unusual cause of breast lump: CSF pseudocyst
Authors: Jakhere Sandeep Gopal , Kumbhar Raju , Dhongade Harshal
Published: May 2014

A ventriculoperitoneal shunt (VP shunt) is a fairly common and useful procedure to reduce intracranial pressure in patients with hydrocephalus. Complications associated with VP shunts are usually related to either shunt obstruction or infection. A pseudocyst formation owing to leakage of CSF into the breast tissue as a complication of VP shunting is a rare entity, with few cases in the literature. Nonetheless, it is an important cause of cystic breast lump and should be kept in mind in a patient with an indwelling VP shunt. We describe the case of a 16-year-old girl patient with an indwelling VP shunt who presented with a gradually increasing breast lump, and was diagnosed to have a CSF pseudocyst based on characteristic imaging findings.
Paediatric neuro-imaging
Authors: Misser Shalendra Kumar
Published: May 2014

No abstract available.
Oncology imaging
Authors: Misser S.K. , Royston D. , Heslop V.
Published: May 2014

No abstract available.
Neonatal imaging
Authors: Misser S.K. , Mitha T.A. , Shaik A.S.
Published: May 2014

No abstract available.
Cribriform pattern in brain MRI: A diagnostic clue for mucopolysaccharidoses
Authors: Biswas Shamick , Chakraborty Sumit
Published: May 2014

Mucopolysaccharidoses (MPS) represents a heterogeneous group of inherited lysosomal storage disorders characterised by defective degradation of long-chain complex carbohydrates called glycosoaminoglycans (GAGs). To date, 11 distinct types of MPS have been described, each as a result of deficient enzymatic activity of specific lysosomal hydrolase. The most common types are Hurler and Hunter syndromes. We report a case of a child presenting with macrocephaly, clinically suspected to be due to hydrocephalus. An MRI (3 Tesla) brain study demonstrated the cribriform pattern in the brain caused by dilated perivascular spaces, which is a diagnostic clue for the presence of MPS.
Integrated imaging - the complementary roles of radiology and nuclear medicine
Authors: Warwick J. , Lotz J.
Published: May 2014

This article was first published in the August 2013 issue of Continuing Medical Education (Vol. 31, Issue 8), and is reproduced here because of its topicality and desirability of reaching a broader audience.
CT-guided biopsy of suspected malignancy: A potential pitfall
Authors: Henderson Steven , Elsaify Wael
Published: May 2014

Paragangliomas are rare catecholamine-secreting neuro-endocrine tumours that can arise from sympathetic or parasympathetic tissue. Any manipulation of these tumours, without appropriate medical therapy, can result in excess catecholamine release leading to a catecholamine crisis. Neuro-endocrine tumours must be considered prior to interventional biopsy of an unknown soft-tissue mass, and appropriate biochemical investigations should be performed in suspected cases to prevent catastrophic complications.
Cerebral schistosomiasis
Authors: Ravi Naveen , Yi W.X. , Yu L. , Ping H.J. , Hao D.Z.
Published: May 2014

Although schistosomiasis (bilharzia) is one of the most common parasitic infections in humans, schistosomal infection of the nervous system is rare. This report is of an unusual case of primary cerebral schistosomiasis and describes its magnetic resonance imaging appearance.
Dual (type IV) left anterior descending artery
Authors: Baskan Ozdil , Erol Cengiz , Paksoy Yahya
Published: May 2014

Congenital coronary artery anomalies are uncommon. Dual left anterior descending coronary artery (LAD) is defined as the presence of two LADs within the anterior interventricular sulcus (AIVS), and is classified into four types. Type IV is a rarely reported subtype and differs from the others, with a long LAD originating from the right coronary artery (RCA). Dual LAD is a benign coronary artery anomaly, but should be recognised especially before interventional procedures. With the increasing use of multidedector computed tomography (MDCT), it is essential for radiologists to be aware of this entity and the cross-sectional findings.
Complete molar pregnancy in a 53-year-old woman
Authors: Adroos Narosha
Published: May 2014

No abstract available.
Medical negligence
Authors: Otto S.F.
Published: May 2014

The progress made in diagnostic and therapeutic medicine has resulted in an increase in the number of malpractice suits brought against medical practitioners. To constitute negligence it must be shown that the conduct of the accused did not measure up to the standard of care the law required of him in the particular circumstances and that he acted with guilt and therefore can be blamed for the deed. This paper describes medical practitioner negligence and reviews relevant cases.
Reflex sympathetic dystrophy/complex regional pain syndrome, type 1
Authors: Botha S.H.
Published: May 2014

Complex regional pain syndrome (CPRS), type 1 is a pain disorder that develops unpredictably and can follow a minor injury. A 12-year-old boy presented with severe pain in the feet and could not walk or stand weight bearing. Normal X-rays showed osteopenic changes and radiolucent lines, which appeared to be stress fractures. Three-phase bone scintigraphy showed no uptake in the left lower leg on the blood pool phase or on the immediate or delayed images. This indicated typical CPRS type 1 in children. The uptake in the right foot was increased and the stress fracture and other illness could not be differentiated. Computed tomography was done to exclude stress fractures. Only osteopenic changes in both calcaneus bones were found and there was no evidence of cortical stress fractures. Magnetic resonance images revealed oedema in the calcaneus and talus bones of both feet. The patient received epidural narcotic infusion with sympathetic blockage for 1 week combined with extensive physiotherapy. The blood pool phase of the bone scan became normal within 2 weeks, and increased uptake in both feet was noticed. The patient was followed up with MRI every 3 months and the bone marrow oedema disappeared after 6 months.
Coming of age
Authors: Duncan Ian C.
Published: May 2014

No abstract available.
Focal fatty infiltration and focal fatty sparing of the liver
Authors: Corr P.
Published: May 2014

Focal fatty infiltration and focal fatty sparing of the liver may be confused with multiple liver metastases on both ultrasound and computed tomography (CT) imaging. Radiologists need to be aware of this benign condition so that unnecessary investigations and liver biopsies can be avoided.
Meningio-angiomatosis - case report and subject review
Authors: Duncan Ian C. , Spiro F.I.
Published: May 2014

No abstract available.
Amoebic liver abscess with pleuropulmonary complications and enlarged gallbladder
Authors: Modishi M.H. , Ahmad S.
Published: May 2014

No abstract available.
Descending necrotising mediastinitis
Authors: Vermeulen W.J.N. , Scheepers P.A. , Khan N.
Published: May 2014

No abstract available.
A case of atypical meningioma
Authors: Mabiletsa M.A. , Tsatsi L.D.R.
Published: May 2014

No abstract available.
MRI detects more tumours than mammograms in high-risk women with genetic predisposition to breast cancer
Authors: Radiology SA Journal of
Published: May 2014

No abstract available.
Stochastic spatial disaggregation of extreme precipitation to validate a regional climate model and to evaluate climate change impacts over a small watershed
Authors: Gagnon P. , Rousseau A. N.
Published: May 2014

Abstract. Regional climate models (RCMs) are valuable tools to evaluate impacts of climate change (CC) at regional scale. However, as the size of the area of interest decreases, the ability of a RCM to simulate extreme precipitation events decreases due to the spatial resolution. Thus, it is difficult to evaluate whether a RCM bias on localized extreme precipitation is caused by the spatial resolution or by a misrepresentation of the physical processes in the model. Thereby, it is difficult to trust the CC impact projections for localized extreme precipitation. Stochastic spatial disaggregation models can bring the RCM precipitation data at a finer scale and reduce the bias caused by spatial resolution. In addition, disaggregation models can generate an ensemble of outputs, producing an interval of possible values instead of a unique discrete value. The objective of this work is to evaluate whether a stochastic spatial disaggregation model applied on annual maximum daily precipitation (i) enables the validation of a RCM for a period of reference, and (ii) modifies the evaluation of CC impacts over a small area. Three simulations of the Canadian RCM (CRCM) covering the period 1961–2099 are used over a small watershed (130 km2) located in southern Québec, Canada. The disaggregation model applied is based on Gibbs sampling and accounts for physical properties of the event (wind speed, wind direction, and convective available potential energy – CAPE), leading to realistic spatial distributions of precipitation. The results indicate that disaggregation has a significant impact on the validation. However, it does not provide a precise estimate of the simulation bias because of the difference in resolution between disaggregated values (4 km) and observations, and because of the underestimation of the spatial variability by the disaggregation model for the most convective events. Nevertheless, disaggregation illustrates that the simulations used mostly overestimated annual maximum precipitation depth in the study area during the reference period. Also, disaggregation slightly increases the signal of CC compared to the RCM raw simulations, highlighting the importance of spatial resolution in CC impact evaluation of extreme events.
A Comprehensive Clinical Study about Patching after Strabismus Surgery
Authors: Zhang Wenqiu , Zeng Jihong , Liao Jinying , Yang Tao , Ren Jie , Zhou Xiaozhou , Liu Longqian
Published: May 2014

Purpose

Patching of the operative eye is occasionally used in pediatric strabismus surgery. The primary purpose of this study was to investigate the psychological and physiologic effects of patching after operation by multifactorial methods.

Methods

We analyzed the perioperative behaviors of 61 children with strabismus conducted from June 2012 to July 2013 in this prospective longitudinal study. The children were randomized into 2 groups. Patients in the patching group underwent postoperative patching and others received no patching. Main outcome measures included The Faces Pain Scale–Revised score or numerical rating scales score, Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) score, crying time, and pre-operative and postoperative physiologic parameters.

Results

Crying time was significantly longer in the patching group than in the no patching group, but self-report scores showed no difference in the groups. Repeated-measures analysis of variance on ranks revealed that postoperative CHEOPS score was lower in the no patching group than in the patching group, whereas no physiologic parameters were significantly different in the 2 groups.

Conclusions

Patching is not necessary for reducing postoperative pain or the risk of infection in children undergoing strabismus surgery.
The Ocular Biometric Differences of Diabetic Patients
Authors: Kocatürk Tolga , Zengin Mehmet Özgür , Çakmak Harun , Evliçoğlu Gökhan Evren , Dündar Sema Oruç , Ömürlü İmran Kurt , Ünübol Mustafa , Güney Engin
Published: May 2014

Purpose

To investigate the differences in ocular biometric and keratometric characteristics in comparison with biometric measurements using the noncontact optical low coherence reflectometer (OLCR) (Lenstar LS 900, Haag-Streit) on diabetic patients.

Methods

The eyes of 170 patients were included in this study, including 81 diabetic and 89 nondiabetic subjects. Optical biometric measurements of diabetic and nondiabetic patients (between the ages of 25 and 85 years) who applied to the ophthalmology clinic were noted from March to June 2013. Detailed ophthalmologic examinations were done for every subject. Biometric measurements were done using the noncontact OLCR device.

Results

Patient age ranged from 29 to 83 years. Subgroup analyses were done in diabetic patients according to their Hba1C levels. The minimum Hba1C value was 5.3, maximum was 12.4, and mean was 7.56 ± 1.48. The median duration of diabetes was 5 years (25th-75th percentile 3.00-11.75). Diabetic patients were found to have thicker lens and shallower anterior chamber in both eyes compared to nondiabetic control subjects. There were no statistical differences between the groups according to central corneal thickness, axial length, or keratometric values in both eyes. However, lens thicknesses were found to be thicker and anterior chamber depth values were found to be shallower in the diabetic group in both eyes.

Conclusions

It may useful to determine eyeglasses prescription, refractive surgery calculation, lens selection, and previous cataract surgery according to biometric measurements after the regulation of blood glucose.
Discordant Retinoblastoma in Monozygotic Twins Due to Deletion of 13Q14
Authors: Messina-Baas Olga M. , Arroyo-Yllanes María Estela , Pérez-Pérez J. Fernando , González-Huerta Luz María , Cuevas-Covarrubias Sergio Alberto
Published: May 2014

Purpose

To report discordant retinoblastoma in monozygotic twins, confirmed by GeneScan.

Methods

One twin presented unilateral retinoblastoma that was treated with enucleation; the other twin had no retinoblastoma. To confirm monozygosity, DNA from leukocytes was analyzed through GeneScan with highly polymorphic markers; to exclude 13q14 deletion, FISH analysis was performed in leukocytes and oral cells of both twins and their parents and in retinal tissue of the affected twin with the cDNA LSI RB1 probe.

Results

GeneScan analysis confirmed monozygosity. 13q14 deletion was observed in homozygous state in retinal tissue and in heterozygous state in oral cells and leukocytes of the affected twin. The nonaffected twin and parents showed no deletion of 13q14.

Conclusions

These data show unexpected differences in monozygotic twins that could be explained by postzygotic events in embryonic development.
Intra- and Postoperative Risks and Complications of Small-Gauge (23-G) versus Conventional (20-G) Vitrectomy for Macular Surgery
Authors: Pielen Amelie , Guerra Nuria I. Pérez , Böhringer Daniel , Junker Bernd , Bühler Anima D. , Stahl Andreas , Agostini Hansjürgen T. , Ehlken Christoph
Published: May 2014

Purpose

To compare the complication spectrum and rate of 23-G and 20-G vitrectomy for macular surgery.

Methods

This was a retrospective comparative analysis of 20-G and 23-G vitrectomy (introduced in 2007) for macular surgery due to macular pucker or macular hole performed between 2006 and 2010 in 61 and 59 eyes, respectively, by 2 experienced surgeons and 2 trainees. We assessed the adjusted hazard ratio for vitrectomy 23-G vs 20-G with a Cox proportional hazard model. We counted retinal detachment, vitreous hemorrhage, endophthalmitis (as early postoperative complications), or cataract progression (as late postoperative complication) as endpoint. We adjusted for indication, surgeon, retinopexy method, and the endotamponade.

Results

Follow-up averaged 712 days. Median time to first event was 385 days in the 23-G group and 342 days in the 20-G group. Cox proportional hazard analysis showed no significant difference between vitrectomy 23-G vs 20-G with regard to postoperative complications (hazard ratio 0.79, 95% confidence interval 0.41-1.52). The other covariates did not exert a statistically significant effect on the risk of adverse events. Looking at individual complications, retinal detachment was exclusively found after 20-G.

Conclusions

In this homogenous large cohort, we did not find a statistically significant difference in rates of complications between 23-G and 20-G vitrectomy techniques for macular surgery. Trainees performed equally well as experienced surgeons.
Knowledge of the Brain Death Concept by Personnel in Spanish and Latin-American Healthcare Centers
Authors: Ríos Antonio , López-Navas Ana Isabel , Ayala-García Marcos A. , Sebastián Maria José , Abdo-Cuza Anselmo , Alán Jeannina , Martínez-Alarcón Laura , Ramírez Ector Jaime , Muñoz Gerardo , Palacios Gerardo , Suárez-López Juliette , Castellanos Ricardo , González Beatriz , Martínez Miguel Angel , Díaz Ernesto , Nieto Adrián , Ramírez Pablo , Parrilla Pascual
Published: May 2014

Background

The knowledge and acceptance of the concept of brain death (BD) among health care personnel is fundamental.

Objective

To analyze the level of understanding of the BD concept among personnel in Spanish and Latin American healthcare centers and to determine the factors affecting this attitude.

Material and methods

Data from 12 hospitals and 32 primary care centers in 4 countries within the International Collaborative Donor Project were selected (Spain, Mexico, Cuba and Costa Rica (n = 4378)).

Results

62% of the personnel (n = 2714) understood BD and believed that this was the death of an individual. Of the rest, 30% (n = 1 333) did not understand it and the remaining 8% (n = 331) believed it did not mean the death of a patient. 83% (n = 931) of physicians understood BD, compared to 75% (n = 895) of nurses, 55% (n = 299) of healthcare assistants, 53% (n = 108) of non-healthcare university-educated personnel and 36% (n = 481) of those without a university education (p<0.001). 68% (n = 1084) of Mexicans understood BD compared to 66% (n = 134) of Cubans, 58% (n = 1411) of Spaniards, and 52% (n = 85) (p<0.001) of Costa Ricans. There were significant relationships between knowledge of the concept and the following: type of healthcare center (p<0.001), clinical service (p<0.001), having spoken about organ donation within the family (p<0.001) and one's partner's attitude to the subject (p<0.001). A direct relationship has been found between understanding the concept and attitude toward deceased donation (p<0.001).

Conclusions

The understanding of BD by personnel from healthcare centers was not as good as expected. There were marked differences depending on job category.
Recent Advances in Nerve Tissue Engineering
Authors: Zhang Bill G.X. , Quigley Anita F. , Myers Damian E. , Wallace Gordon G. , Kapsa Robert M.I. , Choong Peter F.M.
Published: May 2014

Nerve injury secondary to trauma, neurological disease or tumor excision presents a challenge for surgical reconstruction. Current practice for nerve repair involves autologous nerve transplantation, which is associated with significant donor-site morbidity and other complications. Previously artificial nerve conduits made from polycaprolactone, polyglycolic acid and collagen were approved by the FDA (USA) for nerve repair. More recently, there have been significant advances in nerve conduit design that better address the requirements of nerve regrowth. Innovations in materials science, nanotechnology, and biology open the way for the synthesis of new generation nerve repair conduits that address issues currently faced in nerve repair and regeneration. This review discusses recent innovations in this area, including the use of nanotechnology to improve the design of nerve conduits and to enhance nerve regeneration.
Endotoxin Adsorption using Polymyxin B Immobilized Fiber Cartridges in Severe Sepsis Patients following Cardiac Surgery
Authors: Yaroustovsky Michail , Abramyan Marina , Krotenko Nickolay , Popov Dmitry , Plyushch Marina , Popok Zakhar
Published: May 2014

Introduction

Sepsis still represents an obstacle in modern medicine. The purpose of this study was to evaluate the safety and effectiveness of selective lipopolysaccharide (LPS)-adsorption therapy using polymyxin B immobilized fiber cartridges in adult patients complicated with severe sepsis after cardiac surgery.

Methods

65 patients received extracorporeal LPS-adsorption procedures using Toraymyxin columns (PMX; Toray, Tokyo, Japan) in addition to the standard treatment according to the Surviving Sepsis Campaign guidelines. The inclusion criteria were clinical signs of severe sepsis, endotoxin activity assay (EAA) ≥0.6, and blood plasma procalcitonin (PCT) >2 ng/ml. For the control group, we selected 40 patients who were comparable with the study group but who received only the standard therapy.

Results

Each patient received 2 standard LPS-adsorption procedures (lasting for 120 min each). After the LPS-adsorption course, we noted any indices of hemodynamic improvements, including an increase in mean arterial pressure from 73 to 89 mmHg (p<0.001), mean oxygenation index (213-265, p<0.001. We observed a decrease in LPS concentrations by the EAA (0.71-0.55, p<0.001) and by the LAL test (1.44-0.36 EU/ml, p<0.001). In the control group, there were no significant changes in any of the studied parameters. Moreover, the 28-day mortality was 42% in the study group and 65% in the control group (p = 0.032). The endotoxin adsorption procedures were not associated with any adverse reactions, and specifically, no extracorporeal circuit thrombosis cases were noted.

Conclusions

Selective LPS-adsorption is a safe and possibly effective adjunctive treatment method for severe sepsis patients.
Type of Vascular access and Location in Online Hemodiafiltration and its Association with Patient's Perception of Health-Related Quality of Life
Authors: Moura Alexandra , Madureira José , Alija Pablo , Fernandes João Carlos , Oliveira José Gerardo , Lopez Martin , Filgueiras Madalena , Amado Leonilde , Sameiro-Faria Maria , Miranda Vasco , Vieira Margarida , Santos-Silva Alice , Costa Elísio
Published: May 2014

Purpose

The aim of this work is to evaluate the patient-reported health-related quality of life (HRQOL), according to the type and location of vascular access used for dialysis procedure.

Methods

In this transversal study, 322 end-stage renal disease (ESRD) patients under online hemodiafiltration (OL-HDF, 59.63% males; 64.9±14.3 years) were enrolled. Arteriovenous fistula (AVF) was used by 252 patients (78.3%), whereas 70 patients (21.7%) had a central venous catheter (CVC). Besides AVF location, data on comorbidities, hematological data, iron status, dialysis adequacy, nutritional and inflammatory markers were collected. Moreover, the patients’ reported HRQOL score, using the Kidney Disease Quality of Life-Short Form, was evaluated.

Results

ESRD patients using CVC as vascular access presented a decrease in four SF-36 domain scores, namely physical functioning, emotional well-being, role-emotional and energy/fatigue when compared with those using AVF as vascular access. Additionally, these patients also showed significant differences in ESRD target areas, namely decline in cognitive function and quality of social interaction domains. When comparing the variables according to the localization of the AVF, significant differences were found in three SF-36 domain scores, namely physical functioning, pain and general health. Moreover, we also found significant differences in ESRD target areas, namely symptoms/problem list, effects of kidney disease and quality of social interaction domains.

Conclusions

Our results showed that ESRD patients under OL-HDF using AVF as vascular access had higher HRQOL scores in several domains when compared with those using CVC. Additionally, we also found that dialysis patients using AVF in the left forearm presented with higher HRQOL scores.
Percutaneous Translumbar Catheterization of the Inferior Vena Cava as an Emergency access for Hemodialysis – 5 Years of Experience
Authors: Kade Grzegorz , Leś Jarosław , Buczkowska Magdalena , łabuś Małgorzata , Niemczyk Stanisław , Wańkowicz Zofia
Published: May 2014

Patients and Methods

In this study, 13 patients (11 men and 2 women) undergoing hemodialysis (HD) with the use of a catheter placed into the inferior vena cava with percutaneous translumbar access were retrospectively evaluated. In the studied group, 16 procedures of percutaneous translumbar catheterization were performed. Complications connected with the presence of catheter, such as hematoma, thrombosis, infection, catheter movement or unsuccessful catheterization, were analyzed. Moreover, another aspect of our report was to evaluate the adequacy of HD treatment performed by lumbar catheter.

Results

The total time of translumbar catheter observation was 4,169 days. Average time of their functioning was 261 days. The most frequent reason for termination of the use of translumbar HD catheters was spontaneous/idiopathic removal – 2 cases. Episodes of infection and thrombosis per 1,000 days of catheter observation were 2.2 and 1.2, respectively.

Conclusions

Based on our study, we can conclude that correctly performed percutaneous translumbar catheterization of the inferior vena cava, in order to produce a long-term vascular access for HD, is a valuable and safe method in patients after depletion of standard vascular accesses.
A Refinement of Hong's Technique for the Removal of Stuck Dialysis Catheters: An Easy Solution to a Complex Problem
Authors: Quaretti Pietro , Galli Franco , Fiorina Ilaria , Moramarco Lorenzo Paolo , Spina Monica , Forneris Giacomo , Torresi Mario , Bellazzi Roberto
Published: May 2014

Aim

A long-term tunneled hemodialysis catheter can be difficult or impossible to pull out if a fibrin sleeve has attached it to the venous wall. We report the outcome of a refinement of Hong's technique for removing incarcerated catheters aimed at improving its feasibility and safety.

Methods

We applied a modification of Hong's technique in four patients (two males, age ranging from 51 to 68 years) with jugular twin hemodialysis catheters (five of eight lines incarcerated). Hong pioneered the technique of endoballooning to expand a stuck central venous catheter, thus freeing it from adhesions. In our technical refinement, we cut the catheter close to its venous entry point in order to facilitate pullout and inserted a valved introducer as access for guide wires as well as for inflations of the catheter balloon. A stiff guide wire was placed in the inferior vena cava to avoid potential damage to heart cavities. Dilation was monitored under fluoroscopy with constrictions showing points where the catheter was incarcerated. If adhesions persisted through the same introducer, endoluminal dilations were repeated with a larger diameter balloon until the catheter was released. New catheters can be positioned using the stiff guide wire already in place. All removals were carried out under local anesthesia in an angiographic room by interventional radiologists.

Results

All catheters were successfully removed without complications. Average fluoroscopy time for removal was 12 minutes. In the case of a Tesio catheter removed after 12 years because of infection, a computed tomography scan 2 months later revealed persistence of a calcified fibrin sleeve in the vessel.

Conclusions

Hong's technique was confirmed to be a simple, safe and highly effective way to remove incarcerated long-term central venous catheters. The refinements we adopted made the procedure more flexible and possibly less prone to complications. By properly using ordinary tools available anywhere, Hong's technique could be considered Columbus’ egg in this previously risky field.
Stenosis Complicating Vascular access for Hemodialysis: Indications for Treatment
Authors: Pirozzi Nicola , Garcia-Medina José , Hanoy Mélanie
Published: May 2014

The aim of the multidisciplinary team committed to the care of vascular access (VA) for hemodialysis is to prolong as much as possible the functional patency of the access. Stenosis is definitely the most frequent complication of arteriovenous VA. Whereas the best surveillance strategy is still a matter of debate, some evidence is now available about treatment indication and options. The available body of evidence on the best strategy facing this complication of VA is reviewed.