819 research outputs found
Induction skull melt spinning of reactive metal alloys
An apparatus for melting and rapid solidification casting of metal alloys has a crucible for molding a metal charge. The crucible has side walls, a top and a bottom having an orifice therein. Collectively, the side walls, top and bottom define an interior of the crucible. A portion of the dimensions of the side walls of the side walls and bottom is divided by longitudinal slits into at least two segments. A nozzle is disposed partially within the crucible and extends through the orifice. The nozzle has a first end in communication with the interior of tune crucible. A second end of the nozzle has a nozzle orifice therein for defining a stream of molten metal alloy. A cooling mechanism cools the top, side walls and bottom of the crucible. The apparatus has mechanisms for inducing alternating electrical currents within the metal charge and within the nozzle, and for establishing and maintaining pressure within the interior of the crucible. A positioning mechanism positions the crucible and nozzle means relative to a quenching mechanisms that includes a rapidly moving chill substrate. The crucible, nozzle and quenching mechanism are housed within an enclosure that provides there within a controlled atmosphere having positive or negative pressure
The Effect of Different Plaque Control Modalities on the Keratinizing Potential of the Sulcular Epithelium in Monkeys
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141055/1/jper0632.pd
Heat treatment of rapidly quenched Fe-6.5 wt % Si ribbon
A rapidly quenched Fe-Si Alloy containing 6 to 7 wt % is heat treated to promote and control an order-disorder reaction, thereby improving its ac core loss and exciting power at induction levels about B=1.2 T. The alloy has a substantially texture, a grain size of about 1 to 2 mm, a R2 domain size of 100 to 850 nm, a DO3 domain size of about 5 to 25 nm, an ac core loss of about 1.2 to 1.6 W/kg and an exciting power of about 15 to 46 VA/kg, the core loss and exciting power being measured at an induction level of B=1.4 T and a frequency of f=60 Hz
Histologic Evaluation of Periodontal Implants in a Biologically āClosedā Model
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141262/1/jper0110.pd
The effect of antifibrinolytic agents on the healing of modified Widman flaps in monkeys
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65632/1/j.1600-0765.1984.tb00810.x.pd
Determination of suitable housekeeping genes for normalisation of quantitative real time PCR analysis of cells infected with human immunodeficiency virus and herpes viruses
The choice of an appropriate housekeeping gene for normalisation purposes has now become an essential requirement when designing QPCR experiments. This is of particular importance when using QPCR to measure viral and cellular gene transcription levels in the context of viral infections as viruses can significantly interfere with host cell pathways, the components of which traditional housekeeping genes often encode. In this study we have determined the reliability of 10 housekeeping genes in context of four heavily studied viral infections; human immunodeficiency virus type 1, herpes simplex virus type 1, cytomegalovirus and varicella zoster virus infections using a variety of cell types and virus strains. This provides researchers of these viruses with a shortlist of potential housekeeping genes to use as normalisers for QPCR experiments
Effectiveness of Subgingival Scaling and Root Planing: Single Versus Multiple Episodes of Instrumentation
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142277/1/jper0367.pd
The pathogenesis of pulmonary hypertension - an update
Elevation of the mean pulmonary arterial pressure to ā„25 mm Hg within the low-pressure system of the pulmonary circulation is defined as pulmonary hypertension. Pulmonary hypertension may be the consequence of various clinical and pathophysiological entities. Many of these conditions, however, result in a final common pathway of pathogenesis. This pathway is characterised by the triad of excessive vasoconstriction, microthrombosis and remodelling of pulmonary arteries. Remodelling is arguably the most important factor: its complex pathogenesis is not completely understood and no specific treatment directly targets vascular remodelling. This article aims to review the current understanding of the pathogenesis of pulmonary hypertension and to give insights in future developments in this evolving field
Vascular Health in American Football Players: Cardiovascular Risk Increased in Division III Players
Studies report that football players have high blood pressure (BP) and increased cardiovascular risk. There are over 70,000 NCAA football players and 450 Division III schools sponsor football programs, yet limited research exists on vascular health of athletes. This study aimed to compare vascular and cardiovascular health measures between football players and nonathlete controls. Twenty-three athletes and 19 nonathletes participated. Vascular health measures included flow-mediated dilation (FMD) and carotid artery intima-media thickness (IMT). Cardiovascular measures included clinic and 24 hr BP levels, body composition, VO2 max, and fasting glucose/cholesterol levels. Compared to controls, football players had a worse vascular and cardiovascular profile. Football players had thicker carotid artery IMT (0.49 Ā± 0.06 mm versus 0.46 Ā± 0.07 mm) and larger brachial artery diameter during FMD (4.3 Ā± 0.5 mm versus 3.7 Ā± 0.6 mm), but no difference in percent FMD. Systolic BP was significantly higher in football players at all measurements: resting (128.2 Ā± 6.4 mmHg versus 122.4 Ā± 6.8 mmHg), submaximal exercise (150.4 Ā± 18.8 mmHg versus 137.3 Ā± 9.5 mmHg), maximal exercise (211.3 Ā± 25.9 mmHg versus 191.4 Ā± 19.2 mmHg), and 24-hour BP (124.9 Ā± 6.3 mmHg versus 109.8 Ā± 3.7 mmHg). Football players also had higher fasting glucose (91.6 Ā± 6.5 mg/dL versus 86.6 Ā± 5.8 mg/dL), lower HDL (36.5Ā±11.2 mg/dL versus 47.1Ā±14.8 mg/dL), and higher body fat percentage (29.2Ā±7.9% versus 23.2Ā±7.0%). Division III collegiate football players remain an understudied population and may be at increased cardiovascular risk
Deep brain stimulation can suppress pathological synchronisation in parkinsonian patients
Background Although deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a highly effective therapeutic intervention in severe Parkinson's disease, its mechanism of action remains unclear. One possibility is that DBS suppresses local pathologically synchronised oscillatory activity.Methods To explore this, the authors recorded from DBS electrodes implanted in the STN of 16 patients with Parkinson's disease during simultaneous stimulation (pulse width 60 mu s; frequency 130 Hz) of the same target using a specially designed amplifier. The authors analysed data from 25 sides.Results The authors found that DBS progressively suppressed peaks in local field potential activity at frequencies between 11 and 30 Hz as voltage was increased beyond a stimulation threshold of 1.5 V. Median peak power had fallen to 54% of baseline values by a stimulation intensity of 3.0 V.Conclusion The findings suggest that DBS can suppress pathological 11-30 Hz activity in the vicinity of stimulation in patients with Parkinson's disease. This suppression occurs at stimulation voltages that are clinically effective
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