Magnetic Ordering in 3He Nano-Clusters

Simultaneous measurements of magnetic susceptibility from 0.5 to 10 mK and pressure from 2.88 to 3.54 MPa have been made in ³ He nano-clusters embedded in a ⁴ He matrix, following phase separation. The susceptibility of the 3.54 MPa, all-solid sample behaves similarly to that of bulk ³ He for v=21.3 cm ³ /mole, with a Weiss constant =–250K. For the 2.88 MPa, liquid-droplet sample, =140K, indicating a ferromagnetic tendency, similar to 2-D films at some coverages. At intermediate pressures, has a peak near 1.05 mK, but without a discontinuity. For all samples, had a solid-like contribution to the lowest temperatures. Magnetic ordering in nano-clusters appears to be different than the U2D2 phase of bulk ³ He.     

Video-assisted lateral intertransverse process arthrodesis. Validation of a new minimally invasive lumbar spinal fusion technique in the rabbit and nonhuman primate (rhesus) models

STUDY DESIGN: Cadaveric anatomic and in vivo survival animal studies were performed to develop a new arthrodesis technique for the lumbar spine. OBJECTIVES: To examine the feasibility, efficacy, and safety of a minimally invasive lumbar intertransverse process arthrodesis technique using an osteoinductive growth factor (rhBMP-2) delivered in a collagen sponge carrier. The technique was first developed using a rabbit model and modified for the nonhuman primate (rhesus monkey), a larger animal with the most similar bone biology to humans. SUMMARY OF BACKGROUND DATA: The morbidity of conventional posterolateral lumbar intertransverse process arthrodesis includes graft donor site morbidity; paraspinal muscle devascularization, denervation, and scarring and nonunion in up to 36% of patients. Minimally invasive anterior lumbar interbody arthrodesis techniques have been developed, but these often require a metal implant and carry risks to major vessels and development of retrograde ejaculation. A minimally invasive technique for posterolateral intertransverse process arthrodesis has not been described previously. METHODS: In Part 1, we examined seven New Zealand white rabbits and five rhesus monkeys at necropsy and during nonsurvival surgeries to determine the best access routes and to develop special instruments for video-assisted lateral intertransverse process arthrodesis. In Part 2, 38 New Zealand white rabbits underwent L4-L5 intertransverse process arthrodesis: the "OPEN" group (n = 16) underwent a standard open muscle-splitting approach using rhBMP-2 (bone morphogenetic protein) and collagen as a bone graft substitute; the "video-assisted control" group (n = 6) underwent video-assisted lateral intertransverse process arthrodesis with the collagen implant only (no growth factor); and the "video-assisted-BMP" group (n = 16) underwent video-assisted lateral intertransverse process arthrodesis with rhBMP-2 and collagen as the graft material. In Part 3, rhesus monkeys (n = 4) underwent video-assisted lateral intertransverse process arthrodesis using rhBMP-2 and collagen after laminectomy of L4-L5. RESULTS: In Part 1, we identified expedient, minimally invasive routes to the intertransverse process interval appropriate for each species: an intermuscular approach for the rabbit and a lateral, extramuscular approach for the rhesus monkey. In Part 2, all rabbits in the OPEN and video-assisted-BMP groups achieved solid intertransverse process lumbar fusions when assessed at 10 weeks. There were no neurologic impairments nor any difference between the two groups in the frequency of postoperative infection or other complications. None of the animals in the video-assisted control group showed evidence of fusion. In Part 3, exposure, decortication and grafting with rh-BMP-2 and collagen was accomplished successfully in all four monkeys through the video-assisted minimally invasive approach without complications. CONCLUSION: Video-assisted lateral intertransverse process arthrodesis is a feasible, effective, and safe method of lumbar spinal fusion in the rabbit and rhesus monkey. Use of this arthrodesis procedure will minimize the morbidity of paraspinal muscle denervation and devascularization seen with open intertransverse process fusion techniques, and the use of an osteoinductive growth factor will eliminate the problem of graft donor site morbidity and possibly increase the chances for successful fusion.     

Sarcomatoid carcinomas of the lung: a clinicopathologic review

Sarcomatoid carcinomas (SC) of the lung are the most common pulmonary neoplasms that exhibit a composition by spindled or pleomorphic tumor cells. As such, many of them may be confused easily with true sarcomas diagnostically unless special immunohistological or ultrastructural analyses are performed. Reactivity is expected for keratin, epithelial membrane antigen, or collagen type IV in the sarcomalike elements in SC, although it may be focal. Electron microscopy often shows the presence of junctional complexes between tumor cells, with or without pericellular basal lamina and cytoplasmic skeins of intermediate filaments. Current terminological preferences are such that several formerly used terms--including "spindle-cell carcinoma," "pulmonary blastoma," "squamous cell carcinoma with pseudosarcomatous stroma," "pseudosarcoma," and "carcinosarcoma"--are now encompassed by the more generic designation of "sarcomatoid carcinoma." The clinical course of patients with this neoplasm is aggressive, with an overall 5-year survival rate approximating 20%.     

Influence of protective isolation on outcome of allogeneic bone marrow transplantation for leukemia

Most of the previously published surgical series of suprasellar meningiomas have two disadvantages: (1) patients involved were treated within a relatively long time period, making analysis more difficult, (2) radiographic long term follow-up examinations with either CT- or MRI-scans were not performed. Both disadvantages were overcome in our retrospective clinical study, consisting of 50 consecutive patients with suprasellar meningiomas treated between 1982 and 1991. Radiological, ophthalmological, and neurological investigations were performed preoperatively, postoperatively and at long term follow-up (mean: 5.7 years). A radiologically confirmed radical tumour removal could be achieved in 84% of patients. Both, the peri-operative mortality (2%) and serious operative morbidity (6%) were low. However, 12% of patients developed late onset epilepsy. At long term follow-up, visual function was improved in 67%, unchanged in 9% and worsened in 24%. In more than 50% of patients the vision showed recovery over a longer time period than the first 10 days after operation. Radiographic control examinations revealed tumour recurrences in 2 patients (both asymptomatic) and progress of residual tumour in 5 patients (2 symptomatic, 3 asymptomatic). Since introduction of modern neurosurgery, a clear improvement in the surgical treatment of suprasellar meningiomas can be observed. However, the still long delay in diagnosing these tumours correctly prevents a further improvement of the ophthalmological results at long-term follow-up. Due to a relatively high rate of late onset epilepsy, anticonvulsive prophylaxis for 6 months seems to be justified. Regarding present preoperative diagnostic measures, ia-DSA seems only be indicated in patients with CT/MRI-scans, suspicious for tumourous narrowing or invasion of major cerebral arteries. In addition, we recommend radiographic control examinations at regular time intervals to confirm radical tumour removal and to detect the "ideal" point of time for renewed treatment.     

Competing selfobject functions: the bane of the conjoint therapist

The sheer ferocity of competition over needs rarely exhibits itself more than in the consulting room of the conjoint therapist. While cognitive and behavioral therapies may short-circuit this process by negotiating each partner's "fair share" of wishes and responses, such approaches circumvent the examination of the source of such dire competitiveness. Furthermore, they leave the participants with little depth of understanding of what each so vehemently has at stake. In this realm, the psychoanalytic perspective lends a unique vantage point by helping us understand the depth of unconscious need provoked among marital couples or otherwise committed partnerships.     

An ontological metamodel for cyber-physical system safety,security, and resilience coengineering

Software and Systems Modeling - Cyber-physical systems are complex systems that require the integration of diverse software, firmware, and hardware to be practical and useful. This increased...     

ARBEE: Towards Automated Recognition of Bodily Expression of Emotion in the Wild

International Journal of Computer Vision - Humans are arguably innately prepared to comprehend others’ emotional expressions from subtle body movements. If robots or computers can be...     

Changes in therapeutic principles in fractures of the extremities with severe soft tissue injuries exemplified by tibial fracture

Functional results after open fractures have been improved during the last decades. Especially the rates of amputation and chronic osteitis after open tibial fractures have been reduced from 30% to less than 5%. The initial management of this type of fracture includes reconstruction of the perfusion of the involved vessels, subsequent debridement with resection of avascular tissues, decompression of compartments by fasciotomy and initial shortening of the tibia by osteotomy and followed by callus distraction in order to achieve the physiological length of the leg. Cortical bone with periostal stripping has to be covered by local muscle transfer or by free vascularized tissue transfer within 3-7 days. Bone defects are either reconstructed by cancellous bone graft or, if the defect is longer than 2 cm, by continuous segmental transfer, according to the technique described by Ilizarov.     

Controlled fabrication of nanopores using a direct focused ion beam approach with back face particle detection

We report a direct, ion drilling technique that enables the reproducible fabrication and placement of nanopores in membranes of different thickness. Using a 30?keV focused Ga ion beam column combined with an in situ, back face, multi-channelplate particle detector, nanopores are sputtered in Si(3)N(4) and W/Si(3)N(4) to have diameters as small as 12?nm. Transmission electron microscopy shows that focused ion beam-drilled holes are near-conical with the diameter decreasing from entry to exit side. By monitoring the detector signal during ion exposure, the drilled hole width can be minimized such that the exit-side diameter is smaller than the full width at half-maximum of the nominally Gaussian-shaped incident beam. Judicious choice of the beam defining aperture combined with back face particle detection allows for reproducible exit-side hole diameters between 18 and 100?nm. The nanopore direct drilling technique does not require potentially damaging broad area exposure to tailor hole sizes. Moreover, this technique successfully achieves breakthrough despite the effects of varying membrane thickness, redeposition, polycrystalline grain structure, and slight ion beam current fluctuations.