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Introduction. Vestibular schwannomas (VS) or acoustic neuromas (AN) (as they are known to neurosurgeons) are benign tumors which originate at the junction between central nervous system myelin and peripheral nervous system myelin – an area known as the Obersteiner-Redlich area. Acoustic neuromas represent a special pathologic entity for neurosurgeons due to their important symptoms which need to be adressed as soon as possible and due to the secondary disfunctions which may appear if the tumors are not treated appropriately. Materials and methods. The study below presents the experience of the authors regarding the use of stereotactic radiosurgery for the treatment of acoustic neuromas. The authors focus on a population of 231 patients diagnosed and treated for VS over a period of 10 years at the „Bagdasar-Arseni“ University Hospital in Bucharest. This study compares the impact of Gamma Knife Surgery when performed alone or in association with open microneurosurgery. The authors assessed patients with tumors ranging between 0.25 and 14 cm3 in volume. Gamma Knife Surgery is used successfully to treat VS, both independantly or in association with open microsurgery. Results. The major complications of the treatment are represented by lack of response to treatment (less than 1% of patients) and cerebral edema (16.4% of patients). Conclusions. Given its multiple advantages, stereotactic radiosurgery is right now the tip of the spear regarding the therapeutical means available for VS. When the tumors met in daily practice are larger than the therapeutical resources of the devices used for Gamma Knife Surgery an open microsurgical approach may be attempted followed by stereotactic iradiation of the remnant tumor. Given the large number of successes reported in the literature and the small number of complications but also the ever progressing technology used to improve Gamma Knife devices, the authors consider stereotactic radiosurgery to be a very good solution for the treatment of VS. Furthermore, the improvement potential this technique has grants it the potential to improve standard of treatment for acoustic neuromas and the quality of life in patients with this disease.

This paper describes the implementation of a two-channel analog front-end circuit for electrooculography signals. Due to hyper polarizations and depolarizations between the cornea and the retina, the human eye can be modeled as an electric dipole. An analog signal conditioning circuit has been proposed to capture the electric dipole potential and the saccadic eye movements, by using high precision instrumentation amplifier and integrator circuit to adjust the offset. A right drive leg is implemented to increase the common mode rejection ratio along with a Butterworth low pass filter to eliminate the interference noise from power line sources. Also, it was implemented an isolator circuit to separate the bio-signals from the signals in a microcontroller (human-computer interface) as well as a mask for easy implementation and use to control a wheelchair.

Online technologies offer the promise of an efficient, improved healthcare system. Patients benefit from increased access to care, physicians are afforded greater flexibility in care delivery, and the health system itself benefits from lower costs to provide such care. One method of incorporating online care into clinical practice, called electronic office visits or "eVisits," allows physicians to provide a consultation with patients online. We performed an analysis of the current published literature on eVisits as well as present emerging research describing the use of mobile platforms as the delivery model. We focused on the role of eVisits in acute primary care practice.A literature review was conducted using electronic databases with a variety of search terms related to the use of eVisits in primary care.Several advantages to eVisit utilization in the primary care setting were identified, namely, improvements in efficiency, continuity of care, quality of care, and access to care. Barriers to eVisit implementation were also identified, including challenges with incorporation into workflow, reimbursement, physician technological literacy, patient health literacy, overuse, security, confidentiality, and integration with existing medical technologies.Only one study of patient satisfaction with eVisit acute primary care services was identified, and this suggests that previous analyses of eVisit utilization are lacking this key component of healthcare service delivery evaluations. The delivery of primary care via eVisits on mobile platforms is still in adolescence, with few methodologically rigorous analyses of outcomes of efficiency, patient health, and satisfaction.

The 56 mm single aperture superconducting dipole model with a 5-block coil configuration was reassembled and tested to investigate the full support of electromagnetic forces using a high-manganese steel collar structure without mechanical contribution from an iron yoke. The reassembled model, which has a gap between the high manganese steel collar and the horizontally split iron yoke, reached a central field of 9 tesla (93% of short sample) at the first quench and attained the short sample limit with a few following quenches. The test results of the training quenches and the mechanical behavior after the modification are described.

A 56 mm single aperture superconducting dipole model magnet, which is one of the frameworks of the LHC collaboration between KEK and CERN, has been developed. A central field of 8.65 T is provided at a load line ratio of 90% with a 5 block coil wound with NbTi superconducting cables. The magnet has a straight section of 0.8 m and a total length of 1.2 m. The distinctive features of the magnet are a magnetically symmetrical configuration being applicable to the twin aperture magnet and mechanical consideration sharing the magnetic forces with a high manganese steel collar and a horizontally split iron yoke. The magnet showed almost no training at 4.4 K. The first quench current at 1.8 K was 91% of the short sample I/sub c/ and the magnet reached a central magnetic field of 8.8 T. Finally it could be excited with the current of more than 99% of the short sample limit which corresponds to a central field of 9.63 T.

In the first phase of the R&D programme for LHC dipoles, seven 10-m-long, 50-mm-aperture prototypes have been manufactured by European Industries. The first two prototypes, fabricated under a CERN-INFN Collaboration, were successfully tested in 1994. This paper provides a first assessment of the main test results of these two magnets, in particular for what concerns kinematics and evolution of the stress distribution in the magnet during cooldown, energization and warmup. The influence of some adopted technological solutions is also discussed. Based on test results, some design corrections are proposed for adoption in the design of the future 15-m-long LHC dipole prototype.

A single aperture dipole magnet has been developed with a design magnetic field of 10 tesla by using Nb-Ti/Cu conductor to be operated at 1.8 K in pressurized super fluid helium, The magnet features double shell coil design by using high keystone Rutherford cable and compact non-magnetic steel collars to be adaptable in split/symmetric coil/collar design for twin aperture dipoles. A design central magnetic field of 10 tesla has been successfully achieved in excitation at 1.95 K in pressurized superfluid helium. Test results of the magnet with a summary of the design and fabrication are presented.

FE-calculations have been carried out for the cross-section of the 56 mm superconducting LHC dipole prototype with aluminium common collar and a vertically split yoke. The structure has been studied at room temperature and at 1.8 K both energized and non-energized. Collaring and assembly procedure were also modeled. Considerations are also made about the influence of the tolerances on the behaviour of the structure.

The Large Hadron Collider (LHC) is a superconducting accelerator/collider for protons, heavy ions and electron-proton collisions in the multi-TeV energy range, which will be installed at CERN in the 27 km tunnel of LEP. This new facility will mainly consist of a double ring of high field superconducting magnets operating in superfluid helium at a temperature of 1.9 K. To reach the wanted beam energy (7 TeV for protons) the main dipole magnets will operate at about 8.4 T and the quadrupoles at 220 T/m field gradient. These main magnets have a two-in-one configuration with the magnetic channels for the two beams placed in a common yoke and cryostat. The LHC will have more than 10000 superconducting magnetic units. The arcs of the machine will require about 1250, 14 m long dipoles and 400, 3 m long quadrupoles. After a general outline of the project with more detailed information on the design of the magnets, the paper describes the state of magnet R&D and presents results of short models, among which one reached the record dipole field of 10.5 T, as well as of industry made full scale prototypes which have been successfully tested and measured. >

The corrector magnet for the Large Hadron Collider (LHC) contains a 1.5-T dipole for orbit correction and a 8000 T/m/sup 2/ sextupole for chromaticity correction. The dipole has for compactness been mounted around the sextupole coil. A full-scale prototype of 1.3-m length has been fabricated and tested. The coils were first tested at 4.2 K. It appeared that the training of the impregnated coils could be strongly reduced by increasing the radial precompression. The coils were subsequently cooled to the operational temperature between 1.8 and 2 K and the field quality was measured with a harmonic rotating coil. The results of the tests show that the combined dipole-sextupole corrector magnet does meet the desired field strengths. >

The design options for the superconducting multipole corrector MDOS for the LHC (Large Hadron Collider) are reviewed. A series coil option is studied. The series coil design is able to meet the specified correction requirements within the total length available. Magnetic design computations have shown that the integral field harmonic errors are well within the LHC specification. Design proposals for coil fabrication and assembly are presented. >

CERN is preparing for the construction of the Large Hadron Collider (LHC) to be installed in the Large Electron Positron Collider (LEP) tunnel. The magnetic lattice of the LHC will consist of a ring of twin-aperture dipoles and quadrupoles, connected electrically in series. To adjust the working point of the machine, tuning quadrupoles will be installed in pairs in each regular cell, next to the main quadrupoles. Also, to correct multipolar field errors in the LHC, an octupole correction winding is required near each lattice quadrupole. A nested construction of these two magnets is foreseen. The design of a prototype tuning quadrupole and octupole corrector is described. Details of magnetic and mechanical calculations are given, including results from existing and specially developed computer codes, and model work. Further, the construction procedures are described, including the facilities and tooling developed by ACICA for this work. >

The main features of the dipole magnet design have been frozen in 1996 and important steps for the preparation of their series production are being taken in the current year. To finalize the technical specifications of the superconducting cables and other components, a number of detail variants are being validated with the construction and test of short and long magnets. Thus, beside a number of 1 m long models, four 10 m long models of the main dipoles and two 14.2 m prototypes are being assembled in industry and at CERN. The fabrication of a further set of 3 full length dipoles is also starting in industry to verify the reproducibility of production and performance. The lifetime and fatigue test of the String Test Facility, consisting of three dipoles and one quadrupole and simulating the basic periodic cell of the LHC, has been successfully concluded. The String was repetitively cycled between the injection field of 0.6 T and the operational field of 8.4 T, 24 hours per day, and has accumulated more than 2100 cycles, corresponding to about ten years of machine operation. The final design of the main quadrupoles, based on the use of the dipole coil outer layer cable, is being worked out by CEA, Saclay and the construction of two new prototypes has been launched.

Within the framework of the LHC (Large Hadron Collider) R&D program, CERN and CEA/Saclay have established a collaboration to carry out the design, building and testing of a superconducting LHC prototype quadrupole at the Saclay laboratory. The cold mass of this quadrupole is presently under construction at Saclay. The quadrupole design features a twin aperture configuration, a gradient of 250 T/m, a length of 3 m, and a free coil aperture of 56 mm. European industries participate in this project by delivering components and fabricating the tooling according to specifications prepared by Saclay. The authors present details of the magnet design and construction. Coil winding will start in summer 1991 and the first prototype should be assembled and ready for testing by mid 1992. >

The purpose of this study was to compare the effects of smooth and diamond-coated ultrasonic retrotips on the external and internal surfaces of root-end preparations with the aid of a scanning electron microscope (SEM). Forty-four mesial roots of human mandibular molars were selected. The canals were cleaned, shaped and obturated using gutta-percha and sealer. The apical portions were resected at a 45 degrees-angle bevel exposing both mesial canals and the isthmus area. The roots were then divided into two groups according to the type of root-end preparation: Group A--performed with smooth retrotips (S) and Group B--performed with diamond-coated retrotips (DC). The specimens were coded and prepared for SEM evaluation. Observations of the external surface preparation showed that the S and DC retrotips produced very well-centered cavities involving both canals and isthmus area with minimal deviations and no perforative defects. When the internal surface of the root-end preparations was evaluated, it was evident that the use of S retrotips resulted in clean canal walls with little superficial debris and smear layer. Internal canal surfaces done with DC retrotips were irregular showing patent grooves, in contrast with the more uniform, regular and smoother surfaces when S retrotips were employed.

Superconducting twin-aperture dipole model magnets for the CERN future superconducting collider, the Large Hadron Collider (LHC), were built. The authors report on the magnet quench behavior and the field measurements at low and high magnetic induction. They describe the results obtained with 1-m-long models which have been made in industry. To test different design ideas, four magnets were built with a number of technical variants relating to the type of cable and electrical insulation, details in coils, material, shape and assembly method of the collars and the material of the outer shrinking cylinder. Tests performed on two magnets called MTA-JS and MTA-H are discussed. Measurements of the losses in the superconducting cables and the quenching field at various field ramp rates are used to investigate the temperature margin in superfluid helium under steady-state losses. >

We have studied the sorting and alteration of the thyroglobulin (tg) secreted by well-differentiated carcinomas using a group of anti-tg monoclonal antibodies. A previously described monoclonal antibody, specific for the hormogenic iodinated epitopes, shows that in carcinomas the iodinated tg is not secreted in the colloid as in normal glands but is accumulated in the cytoplasm of the cells. Separation of tg in a concanavalin A column, to isolate the correctly glycosilated protein, reveals that hormogenesis is present only in glycosilated tg with a correct final configuration. An other monoclonal antibody, specific for an epitope connected with the carbohydrate moiety of the tg, reacts with tgs from normal glands and from any thyroid lesion except tg from carcinomas. This tg of carcinomas presents an alteration in the oligosaccharide chains that can be detected by this antibody. The alteration is specific for malignant tumors and could be connected with the missing exocytosis of the iodinated tg in carcinomas.

After a review of the present state of the R.&D. programme, the results of the tests of the first three model magnets are described.

The Large Hadron Collider (LHC) is proposed at CERN as the next facility to push further the frontier of high energy physics. The design of the superconducting dipole magnets is based upon the “two in one” concept in which the dipoles of the two rings of the collider have a common magnetic circuit. Twin aperture models (MTA1) designed for a 10 T field level are being developed in collaboration with European Industries. These high field magnets require a sophisticated mechanical design of the various parts as collars, split iron yoke and outer shrinking cylinder. A structural analysis of the MTA1 magnets has been made at CERN by using the FEM code “ANSYS”. We report on the mechanical analysis and optimization of the magnet during assembly, cooldown and under the electromagnetic forces.

Particle Physics requires higher and higher energy accelerators-colliders to explore the fundamental components of matter. For electron-positron accelerators, circular machines, which make use of low bending magnetic field to limit synchrotron radiation, have probably reached their maximum size with LEP and the trend for the future is towards linear facilities. For high energy hadron accelerators/colliders, superconducting magnets have been adopted in order to save electrical energy and reduce machine size, and the quest for cost efficiency pushes towards higher field. The 9 to 10 tesla range has already been attained in short dipole magnets.

11526 Background: Standard treatment of HGMG is surgical resection followed by adjuvant FRT; chemotherapy is under investgation in postoperative setting combined with external FRT. The phase III study of Stupp et al favours the combined TEM and FRT for newly diagnosed HGMG with encouraging results in terms of both survival and disease free survival. We present the experience achieved in our centre with 18 consecutive patients with HGMG treated with FRT and TEM either concomitant or sequential. Methods: In the period January 2004–January 2006 eighteen consecutive adult patients age range 25–72 years, median 55 years, sex ratio M/F 10/8 with histologically proven HGMG have been refferd in our centre for adjuvant treatment. Most of the patients had deep situated tumors that precluded complete resection which has been performed in 6 out of 18 patients. For the remaining patients stereotaxic biopsy was the procedure of diagnosis. A maximum dose of 60 Gy FRT was delivered with dual energy photon (6–15 MV) linear accelerator over six weeks in 30 sessions. TEM was administered concomitant in continuous low daily doses 75 mg/sqm in five patients (all males) followed by maintenance 150–200 mg/sqm for up to six cycles. For three patients TEM was co-administered for two cycles of 200 mg/sqm during the days 1–5 and 29–33 of radiotherapy course and whereas for the remaining patients the TEM was given sequentially after the completion of FRT up to six cycles in 5/28 days schedule. Results: With a median follow-up of 11.5 months the overall survival was 9.7 months and the survival rate of 78.5%. Clinical examination was performed every week during FRT with neurological improvement and a decrease in the need of anticonvulsivants in all patients. According to CTC criteria no grade 3 and 4 grade toxicities were recorded. After the completion of FRT imaging evaluation (CT/MRI) was performed at 6 weeks time period with tumor regression in 75% of the patients and early recurrence in only 2 cases. Conclusions: Concomitant FRT and TEM is a safe and promising treatment in newly diagnosed cases of HGMG. Our preliminary experience confirms the data from literature and we will present updated results by the ASCO meeting time. No significant financial relationships to disclose.

The first magnet model for the LHC (Large Hadron Collider) is a single-aperture, 1-m-long, dipole magnet based on NbTi cable technology and designed for an 8-T nominal field at 2 K. It reached and passed its nominal field without any quench and attained 9.1 T, where it operated without quenching before the first campaign of tests was voluntarily stopped. In a second test campaign a 9.3 T central field was attained. After a description of the magnet, the authors discuss the cable characteristics, manufacturing tools, and magnet performance. >

An initial design for the Large Hadron Collider to be installed in the tunnel of the CERN LEP machine is based on the so-called two-in-one concept, originally proposed and tested at Brookhaven National Laboratory for fields up to approximately 5 T. The dipole magnets of the two rings have a common magnetic circuit and are located in one cryostat. Two major lines of development are followed for the construction of models of high-field magnets: (1) using Nb/sub 3/Sn superconducting cables at 4.5 K, and (2) using NbTi alloy superconducting cables at 2 K. The models discussed are 1 m long twin aperture dipoles. They employ NbTi alloy superconducting cables at 2 K but, apart from the coils, the mechanical design concepts are equally valid for magnets using using Nb/sub 3/Sn cables. A role of the models is to test the various components and procedures of fabrication in order to obtain the best performances at lowest cost. Possible variants in the design are mentioned. >

After a review of the proposed CERN Large Hadron Collider (LHC) project, the present design of the high-field superconducting magnets is described. One half of each standard cell for the ring of the magnet system under development consists of four ( approximately 10-m long) dipole magnets, a focusing quadrupole magnet, a tuning quadrupole, a combined sextupole/dipole corrector magnet, and a beam observation station. Only the main features of the dipole design are given. Both presently possible routes to high-field/high-current density magnets, using NbTi superconductors at superfluid helium temperatures or Nb/sub 3/Sn at 4.5 K, are summarized. Other major systems such as the vacuum chamber, proton synchrotron, and cavities are also noted. The work then presents the main aspects and the first results of the research and development program that was undertaken in close collaboration with various European industries and laboratories. Emphasis here is on the development of suitable NbTi and Nb/sub 3/Sn wires and cables, and the construction of magnet models (1-m long) and of a 9-m long twin-aperture prototype dipole. >

A focusing insertion will be constructed at an intersection of the ISR, to achieve a reduction of the effective beam height by about a factor 6 in the interaction diamond and a corresponding increase of the luminosity. It will contain eight superconducting quadrupole magnets, capable of producing gradients of 43 Tm-1 in a warm bore of 173 mm diameter: four of them have a magnetic length of 1.15 m and four of 0.65 m. The magnets are also equipped with sextupole windings, to match the gradients to particle momenta over the beam width, and with dodecapole correction windings. After construction and successful operation of a prototype magnet in the laboratory, competitive tenders were obtained from industry on the basis of technical specifications and manufacturing drawings. The magnets proper and the cryostats are being manufactured under two separate contracts. The insertion will be installed within 1980 at intersection I8, for use in physics experiments with a large magnetic spectrometer.

The possible realization of the new 16 TeV hadron collider LHC of CERN presupposes the availability of the techniques to construct 10 tesla twin aperture dipole magnets either by using conventional NbTi magnet technology at 1.8 K or by using a Nb3Sn conductor at 4.2 K. At present both alternatives are under development at CERN in collaboration with European laboratories and industries. A new initiative to explore the Nb3Sn route was started recently in the Netherlands by the Applied Superconductivity Centre at the University of Twente and NIKHEF, the National Institute for Nuclear and High Energy Physics. A 4 years R&D program was started to design and to manufacture a 1 meter Nb3Sn dipole model magnet in collaboration with other research institutes and companies in the Netherlands. The magnet now under development will be the first one meter Nb3Sn LHC dipole model magnet with a twin aperture designed for use at a nominal field of 10 T. The paper reports on general aspects of the design of the magnet and the present state of the developments.

Eight superconducting quadrupoles for a high-luminosity insertion in the ISR have been produced by industrial firms according to CERN design and manufacturing specifications, and assembled and tested at CERN. The horizontal cylindrical cryostats, which contain the windings and steel yoke in a boiling helium bath, have a 173 mm warm bore. For 31 GeV beam energy, the maximum operating gradient on the quadrupole axis is 43 T m/sup -1/ and the maximum field in the windings is 5.5 T. Sextupole windings provide a linear variation of the gradient of up to 4% over the bore width and dodecapole windings trim the field pattern as a function of excitation. This paper reports about production history, acceptance tests, and performance. The results of magnetic measurements are also summarized. The insertion will be installed into the ISR as from August 1980. (7 refs).

Biopsies involve taking samples from living tissue using a biopsy needle. In current clinical practice they are a first mandatory step before any further medical actions are planned. Performing a biopsy on a deep seated brain tumor requires considerable time for establishing and validating the desired biopsy needle pathway to avoid damage. In this paper, we present a system for the visualization, analysis, and validation of biopsy needle pathways. Our system uses a multi-level approach for identifying stable needle placements which minimize the risk of hitting blood vessels. This is one of the major dangers in this type of intervention. Our approach helps in identifying and visualizing the point on the pathway that is closest to a surrounding blood vessel, requiring a closer inspection by the neurosurgeon. An evaluation by medical experts is performed to demonstrate the utility of our system. © 2012 Wiley Periodicals, Inc.