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Objective: Spinal cord astrocytomas are considered diffuse infiltrating tumors. The optimal treatment of these lesions has been controversial. The conventional management with partial resection followed by radiotherapy remains. In order to evaluate this traditional and famous strategy, the authors retrospectively review a series of ten consecutive adult patients with spinal cord astrocytoma treated with conservative surgery and radiotherapy. Methods Results: A retrospective analysis of ten adult patients (4 men and 6 women) with spinal cord astorcytoma. The mean age was 33 years. Cervical cord was involved in 2 patients, cervicothoracic in 3, thoracic in 5. Seven patients had low grade astrocytoma and 3 high grade (2 anaplastic, 1 gliobastoma).Surgery was subtotal excision in 1 patient, partial excision in 3 and biopsy in 6 patients. All patients received postoperative radiotherapy to a median dose of 45 Gy in 25 fractions over 5 weeks. The follow-up period ranged from 7 to 48 months. Postradiotherapy, local tumor control was achieved in 7 cases (6 low gade, 1 high grade) despite incomplete or no resection. Three patients died, one paraplegic patient of pneumonia, and two patients with high grade astrocytoma from tumor progression or dissemination. Conclusion: There is no significant effect of the extent of resection on local relapse. We believe that conservative surgery and radiotherapy provide a balanced strategy in the treatment of adult spinal astrocytoma to maintain neurological outcome and prevent tumor recurrence. Keywords: . astrocytoma . spinal cord tumor . surgical resection . biopsy . radiation therapy . outcome, Introduction Intramedullary spinal cord tumors (IMSCTs) are relatively rare neoplasms, accounting for only 2 to 4% of CNS glial tumors. (6,10) In adults, IMSCTs comprise approximately 20% of all intraspinal [...]

Evaluating the effect of various fiber reinforced composite (FRC) post surface treatments on its tensile bond strength to root canal dentin.

The purpose of this study was to examine the effect of different surface treatments of implant abutment and metal cope fitting surface on their bond strength to provisional resin cement.

The objective of the present study was to compare between two mandibular implant overdentures of class II Kennedy classification. Material and methods: Fourteen male patients (30–45 years) were selected and divided into two equal groups. Group I received a mandibular removable partial over denture retained with implant abutment at the first molar region and with extra coronal attachment to the first premolar. Cross arch stabilization was made by using double Aker clasp on the first and second molars of the opposite side. Group II received a unilateral mandibular removable partial over denture retained with implant abutment at the first molar region and with extra coronal attachment to a splinted first premolar and canine. Patient satisfaction, clinical and radiographic evaluations were carried out at regular recall appointments up to one year from implant loading. Results: There was insignificant increase in the pocket depth and gingival recession and insignificant decrease in the perio test values and plaque index around implants and abutments. There was insignificant increase in the marginal bone loss around implants and abutments in both groups. All patients strongly disagreed the high cost of the treatment. Group II patients were more satisfied regarding aspects of the patients' comfort and phonetics. Conclusion: It is concluded that unilateral removable partial denture was more comfortable and better with speech. The use of dental implant as a distal abutment in class II Kennedy classification reduces all the movements of denture base and results in better healthy condition for the gingival and periodontium of the abutment tooth than when using conventional partial denture.

Abstract: A commercial phase Doppler system was set up, optimized and used to measure the time resolved characteristics of the droplets inside a diesel spray. The purpose of this work was to understand exactly the influence of each system parameter, and to find the best setup enabling measurements in the spray zones that are densest and closest to the injector. Parametric studies were performed to gain an understanding of the particle density limits of the system and their dependence on the system parameters. Then the diesel spray produced by a single-hole injector was measured, with the fuel pressure ranging from 300 to 1300 bar and gas density in the test chamber ranging from ambient conditions to 40 kg/m3. The optic parameters (beam waist size, lenses focal length) were chosen to the best expected values allowed by the optical stand-off of the spray enclosure. The receiver slit width, which was found to have a dramatic effect on the detection of droplets during the injection main period, was tested in the range from 100 μm to 25 μm. Tests were carried out with two different slit lengths, namely 1 mm and 50 μm, with results indicating minimal effect on performance. PMT voltage (gain) was held to a moderately low value between 400 and 500 V and the laser power between 400 and 800 mW in the green line. An optimum burst threshold was found to obtain the best quality data regardless of signal background level, which varies greatly in high-density pulsed sprays. In the end, a set of results from the complete nozzle characterization in various conditions is presented in order to show the practical application of the optimization study and to provide some means of appreciating the results accuracy. The results obtained were also used to show that the gas-jet theory can be used to predict if PDPA measurement are possible in a given experimental situation.

Pineal function was assessed in human subjects by measuring the excretion of melatonin. The hormone was extracted from the urine by adsorption on a nonionic polymeric resin and then elution with organic solvents; its concentration was determined with a bioassay based ontthe dermal melanophore response of larval anurans to melatonin in their bathing medium. Melatonin excretion among healthy, adult volunteers was 5- to 7-fold greater during the hours of sleep, darkness, and recumbancy (23:00–07:00 h) than during the active, waking hours (07:00–15:00 h or 15:00–23:00 h). When 2 subjects slept only during the daylight at odd, 8-hour intervals, their melatonin excretion was also greatest during their time of sleep. Three bedfast fracture patients (for whom sleep data were not available) failed to display melatonin rhythms. A new radioimmunoassay for melatonin was investigated in preliminary studies with experimental animals and was found to be expedient and sensitive; it was not as specific as the bioassay, however. Both analytical methods were used in studies on intact and pinealectomized rats, and the findings suggest that rhythmic melatonin excretion persists (although at a reduced amplitude) in the absence of the pineal. Fasting in the pinealectomized animal abolished the day/night variation in urinary melatonin, but did not have this effect in intact rats.

New doubly salient ac machines in which the field excitation is developed by stationary permanent magnets has recently been undergoing development at the University of Wisconsin. Because of the unique geometry of the stator, these permanent magnets are readily accessible. Therefore, for experimental purposes, simple iron blocks have been used to "short" a large portion of the permanent magnet flux and thus reduce the back emf developed within the machine. However, for practical applications, field weakening schemes involving miniature linear actuators or high torque stepper motors are being explored, as well as machine designs with combined PM and electrical excitation. Preliminary experimental results show that a substantial reduction in the back emf can be readily obtained thus lending credibility to the concept of weakening air gap fields produced by stationary permanent magnets.

Seventy-two strong-motion accelerograph stations, mostly from within the permanent networks of the U. S. Geological Survey and the California Division of Mines and Geology, were triggered during the Morgan Hill earthquake, April 24, 1984. Among the more interesting of the records are the large acceleration (1.29g) at Coyote Lake dam, the Gilroy array spanning the region between the San Andreas and Calaveras faults, the record from Hall's Valley (epicentral distance 4 km), and records from buildings, a bridge, and a dam within 20 km of the epicenter. Digitized data from 16 stations are available on tape.

The Whittier Narrows earthquake of October 1, 1987 generated the largest set of strong-motion records ever obtained from a single earthquake. The California Strong Motion Instrumentation Program (CSMIP) recovered 128 strong-motion records from 101 stations. Of these 101 stations, 63 are ground-response stations and 38 are extensively-instrumented structures. The structures include 27 buildings, eight dams, a suspension bridge, an airport tower, and a power plant. This paper summarizes that data set and highlights records of particular interest.The duration of strong shaking was approximately 3 to 4 seconds at most stations. The maximum peak acceleration values in the CSMIP data set are 0.62 g on the ground and 0.54 g in a structure. The largest acceleration (0.62 g) was recorded at a station near Tarzana, approximately 45 km from the epicenter. Other records of particular interest discussed here include the record from a soft-story building on the Los Angeles State University campus and the records from the Vincent Thomas suspension bridge near Long Beach.Digitization and processing of the accelerograms are underway, and accelerograms from 12 ground-response stations have been digitized as of this writing. The spectra show that the motion at the Tarzana station was dominated by 3 Hz energy. Spectra from other sites are relatively flat and do not show this spectral peak. The attenuation of peak acceleration with distance for this earthquake is compared with the relationship of Joyner and Boore (1981) derived from past earthquakes. On average, the peak acceleration data from this earthquake are higher than would be predicted by the Joyner-Boore model.

Strong-motion records were recovered from nine accelerographs at seven stations of the El Salvador Geotechnical Investigation Center Strong Motion Network following the damaging 5.4 Ms San Salvador earthquake of October 10, 1986. The sites were all within 6 km of the epicenter; peak horizontal accelerations at ground level ranged from 0.32 to 0.72 g. The duration of strong shaking was about 3 seconds at most sites. One 10-story concrete building was instrumented with recorders at the basement, second floor, and roof level. The maximum accelerations recorded at this building were 0.47 g at the basement, 0.69 g at the second floor, and 0.91 g at the roof.Eight of the accelerograms were digitized and processed. A maximum horizontal velocity of 80 cm/s was obtained for a station 4 km from the epicenter. Peak velocity for the other stations ranged from 26 to 75 cm/s. The maximum horizontal displacements ranged from 5 to 18 cm.The San Salvador records and spectra are compared to other close-in observations such as the Station 2 record from the ML 5.6 Parkfield earthquake of 1966. The San Salvador records share many features with the Parkfield record. In general, the peak accelerations recorded at many of the stations are larger than previously recorded values at close-in distances from earthquakes of similar magnitude.

Statement of problem. The success rate of resin-bonded fixed partial dentures is directly related to the adhesive system and the tooth preparation design for good retention. Purpose of study. This in vitro study evaluated the effect of various tooth preparation designs on the bond strength of retainers for adhesive fixed partial dentures. Material and methods. Molar teeth were prepared in the conventional form or with occlusal coverage and opposing grooves and retainers were silicoated and bonded to etched enamel by a bis-glycerol methacrylate adhesive. Bond strengths were determined after water storage and thermocycling. Results. The least mean bond strength was recorded for the conventional form of tooth preparation ( p < 0.05). Conclusion. A combination of 180-degree opposing groove placement at line angles ''wraparound'' and occlusal coverage resulted in the greatest bonding values.(J Prosthet Dent 1997;77:243-9.)

The 2540-foot long, multi-span, curved I10/215 interchange bridge near San Bernardino was extensively instrumented by the California Strong Motion Instrumentation Program (CSMIP) in cooperation with the California Department of Transportation (Caltrans). The locations of the sensors on this freeway interchange bridge were carefully planned to achieve specific instrumentation objectives. Significant sets of strong-motion records were obtained from this bridge during the magnitude 7.5 Landers and the magnitude 6.6 Big Bear earthquakes of June 28, 1992. The epicenters of these earthquakes were about 50 and 30 miles (80 and 48 km) from the bridge, respectively. The maximum ground acceleration at the bridge was about 0.10 g for both earthquakes. The relative motion of the deck across the hinges was recorded and is characterized by sharp spikes in the acceleration records with a peak value as high as 0.81 g during the Landers and 1.02 g during the Big Bear earthquake. Without the spikes the peak acceleration on the bridge would be about 0.40 g during the Landers and 0.30 g during the Big Bear earthquake. The Landers records show that the bridge structure had a period of about 1.7 seconds in the transverse direction and 1.0 second in the longitudinal direction. The maximum relative displacement between the deck and the footing of a 57-foot column was about 16 cm in the transverse direction and 5 cm in the longitudinal direction during the Landers earthquake. The maximum relative displacement across one of the hinges during the Landers earthquake was 1.2 cm in the transverse direction and 3.6 cm in the longitudinal direction.

In this in vitro study, the effects of different surface preparations and resins on the strength and durability of adhesively bonded joints were evaluated. Disk-shaped cobalt-chromium substrate samples of the first group were treated by the Silicoater MD® system. Samples of the two subgroups were bonded with two different bisphenol-A glycidyl methacrylate (Bis-GMA) adhesives. Samples of the second group were treated by the Rocatec®) system and bonded with a Bis-GMA adhesive. Alumina-blasted samples of the third group were bonded with two different types of Bis-GMA adhesive modified with a phosphate monomer. Samples were stored in water for 3 days, or thermocycled and stored in water for 6 months. The joint samples were then tested for tensile bond strength. When the alumina-blasted samples were bonded with Panavia Ex® or Panavia 21® adhesive the highest bond strength was obtained, regardless of the storage conditions. The Silicoater MD method in combination with the Bis-GMA adhesive yielded high initial bond strengths comparable to those obtained with the Panavia systems, but also recorded the highest drops in bond strengths with both types of adhesive after thermal stressing and water storage. The Rocatec system in combination with Nimetic Grip adhesive produced a low but stable bond strength even after thermocycling and water storage.

In this in vitro study, the effect of substrate surface area and substrate thickness on the strength and durability of an adhesively bonded joint was evaluated. Sixty metal substrate samples were cast out of a cobalt-chromium alloy. Samples of the first group were in a disk shape of 2 mm thickness and 35 mm2, 65 mm2, and 95 mm2surface area with a U-shaped loop on the non-testing side. Samples of the second group were in the shape of disks of surface area 65 mm2with a U-shaped loop and thicknesses of 0.5 mm, 1 mm, or 2 mm. All samples were treated by the Silicoater MD® method and bonded with bisphenol-A glycidyl methacrylate (Bis-GMA) adhesive. Samples were either stored in distilled water for 3 days or thermocycled for 5000 cycles followed by storage for 180 days in water at 37 °C. After storage, the tensile bond strength was determined. Increasing the bonded surface area resulted in a significant drop in the initial bond strength values. However, after thermocycling and water storage, the bond strength increased with increasing bonded surface area. Increasing the substrate thickness resulted in a significant increase of the initial bond strength values. After thermocycling and water storage, there were no significant differences in the bond strength values for samples with different thicknesses.

The North Anatolian fault is a well-defined tectonic feature extending for 1400 km across Northern Turkey. The space-time distribution of seismicity and faulting of this zone has been examined with a particular emphasis on the identification of possible seismic gaps. Results suggest several conclusions with respect to the temporal and spatial distribution of seismicity. First, the earthquake activity appears not to be stationary over time. Periods of high activity in 1850–1900 and 1940 to the present bracket a period of relatively low activity in 1910–39. Second, there appears to have been a two-directional migration of earthquake epicenters away from a central region located at about 39°E longitude. The migration to the west has a higher velocity (>50 km/yr) than the migration to the east (=10km/yr). The faulting associated with successive earthquakes generally abuts the previous rupture. Some existing gaps were filled by later earthquakes.

The characteristics of a butane spray from pintle-type injector were studied by droplet velocity and diameter measurements and high speed photography. The accumulator type injector operated off a common rail fuel supply system operated at 13 MPa, and was controlled by a high-speed solenoid valve. Injection was carried out in a chamber at ambient temperature and at the pressure above (0.37 MPa) and below (0.15 MPa) the fuel vapor pressure. Two component phase/Doppler particle analyzer and traverser were used to obtain the droplet diameter and the velocity at numerous locations in the spray. The entire injection event was analyzed as a time-average and also subdivided into three temporal intervals. A, B, and C. The high-speed photographs showed a narrower cone angle during the quasi-steady spray period at the 0.37 MPa chamber pressure compared to the 0.15 MPa case.

Several letters to the editor are presented in response to articles in previous issues including one on the reader's choice for Time's Man of the Year for 1973, another about the truckers'demonstration in the December 17, 1973 issue and "The Great Slap Flap" in the December 3, 1973 issue.

Postoperative hemorrhage and hematoma (PHH) is a patient safety indicator (PSI) representing a universal complication for all surgical procedures. This study examined the association between gender and the rates of PHH from 2000 to 2012.

The article presents several letters to the editor about previously published articles, including "For Better of for Worse" concerning former U.S. President Bill Clinton's campaigning for his wife Senator Hillary Clinton in the March 10, 2008 issue, a piece titled "Bush's Secret Mission" by Bob Geldof in the March 3, 2008 issue about the impact of the administration of U.S. President George W. Bush on Africa and "Legislating Life Decisions" by Nancy Gibbs about political decisions regarding reproductive technologies and embryonic stem cells in March 10, 2008 issue.