Reflected infrared spectrum of a massive protostar in Orion

The infrared source IRc2 in the star-forming region Orion-KL is generally believed to contain a massive and very young star. Its nature and evolutionary status, however, are difficult to determine because it is hidden from direct view by a dense disklike envelope of gas and dust. Here we report observations of infrared radiation (at a wavelength of about 2 microm) that has escaped the surrounding dust in the polar direction, perpendicular to the plane of the disk, and then been reflected towards us by dust farther away from the star. The reflected spectrum contains absorption lines of neutral metallic atoms and carbon monoxide, which we interpret as indicating a source temperature of about 4,500 K. But, given the luminosity of the source, its radius must be at least 300 solar radii-too large to be attained with the modest gas-accretion rates in existing theories of massive-star formation. Whether the infrared radiation is coming from the protostar itself or the self-luminous accretion disk around it, the accretion rate must be around (5-15) x 10(-3) solar masses per year, at least two orders of magnitude greater than is commonly assumed in models of star formation.     

Coexisting conical bipolar and equatorial outflows from a high-mass protostar

The BN/KL region in the Orion molecular cloud is an archetype for the study of the formation of stars much more massive than the Sun. This region contains luminous young stars and protostars but, like most star-forming regions, is difficult to study in detail because of the obscuring effects of dust and gas. Our basic expectations are shaped to some extent by the present theoretical picture of star formation, the cornerstone of which is that protostars accrete gas from rotating equatorial disks and shed angular momentum by ejecting gas in bipolar outflows. The main source of the outflow in the BN/KL region may be an object known as radio source I, which is commonly believed to be surrounded by a rotating disk of molecular material. Here we report high-resolution observations of silicon monoxide (SiO) and water maser emission from the gas surrounding source I. We show that within 60 AU of the source (about the size of the Solar System), the region is dominated by a conical bipolar outflow, rather than the expected disk. A slower outflow, close to the equatorial plane of the protostellar system, extends to radii of 1,000 AU.     

Pediatric spinal bone marrow: assessment of normal age-related changes in the MRI appearance

A retrospective study of 100 children (0-15 years) without known bone marrow abnormality, was performed to elucidate the spectrum of the MRI appearance of spinal bone marrow with age on T1-weighted images at 0.5 T. Fatty marrow distribution and vertebral signal intensity (SI) relative to disk SI were noted in each subject, and allowed the identification of distinctive patterns. The spinal marrow patterns and their relative frequency for different age groups were consistent with the known physiologic conversion from cellular to fatty marrow with age. Between the ages of 0 and 1 year, SI of corporeal ossification centers was similar or lower than SI of adjacent cartilage and disk in 87% of cases. Between the ages of 5 and 15 years, vertebral SI was higher than SI of adjacent disks in 90% of cases. A central or basivertebral zone of high SI consistent with focal fatty marrow was found in 16% and 31% of cases respectively. In conclusion, knowledge of these conversion patterns should serve as a practical aid in the interpretation of MRI examinations of the spine in children.     

Occult lumbar lateral spinal stenosis in neural foramina subjected to physiologic loading

PURPOSE: To measure the effect of extension, flexion, lateral bending, and axial rotation loads applied to the spine on the anatomic relationship of the spinal nerves in the neural foramen to the ligamentum flavum and the intervertebral disk, anc to determine the effect of disk degeneration on the response to loading. METHODS: Cadaveric lumbar motion segments were examined with CT and MR imaging, loaded with pure moment forces, frozen in situ, reexamined with CT, and sectioned with a cryomicrotome. The morphology of the intervertebral disks was classified on the basis of the appearance of the cryomicrotome sections. The neural foramina were classified as having no evident stenosis, as being stenotic, as having occult stenosis, or as showing resolved stenosis on the basis of the images and sections before and after loading. The stenotic and nonstenotic foramina were stratified by disk level, intervertebral disk classification, and type of loading applied. The effect of spinal level, disk type, and load type on the prevalence of stenosis was studied. RESULTS: On average, extension, flexion, lateral bending, and axial rotation resulted in the ligamentum flavum or intervertebral disk contacting or compressing the spinal nerve in 18% of the neural foramina. Extension loading produced the most cases of nerve root contact, and lateral bending produced the fewest cases. Each of the loading types resulted also in diminished contact between the spinal nerve and the intervertebral disk or ligamentum flavum in some cases. Disk degeneration significantly increased the prevalence of spinal stenosis. All foramina associated with advanced disk degeneration and half of the foramina associated with disks having radial tears of the annulus fibrosus either developed occult stenosis or were stenotic before loading. CONCLUSIONS: The study supports the concept of dynamic spinal stenosis; that is, intermittent stenosis of the neural foramina. Flexion, extension, lateral bending, and axial rotation significantly changed the anatomic relationships of the ligamentum flavum and intervertebral disk to the spinal nerve roots.     

Aspects of the humoral immune response to Staphylococcus intermedius in dogs with superficial pyoderma, deep pyoderma and anal furunculosis

In order to evaluate the long term clinical and morphologic results of recapture of a displaced TMJ disk, we recalled for follow-up MR imaging 75 patients who had been treated by attempted disk recapture based on pre-treatment MR imaging 1-6 years earlier. The treatment included a day appliance with inclines to guide the mandible into the therapeutic position and a telescopic night appliance which prevented retrusion of the mandible during sleep. Appliance treatment was followed by rebuilding or resurfacing the posterior teeth of one arch to permanently support the mandible in the therapeutic position. After treatment of 115 joints with displaced disks, 52% of the disks were normally positioned, 23% were improved in position, and 25% showed persistent disk displacement. Symptom relief was 92% in patients with normalized (recaptured) disks, 84% in patients with improved disk position, and 49% in patients with persistent disk displacement. Failure to improve disk position occurred in 7% of the joints with anterior disk displacement and in 44% of the joints with a transverse (sideways) component to the displacement. Forty-five percent of the recaptured-disks improved in contour. We concluded that anterior mandibular repositioning was effective in the treatment of patients with reducing displaced disks primarily when the disks were displaced only in an anterior direction. This treatment can be recommended in anterior disk displacements if the patient has failed more conservative treatment measures, permanent occlusal reconstruction can be justified, and the patient understands that long-term use of a night appliance may be necessary. Anterior mandibular repositioning appears much less effective in cases with a transverse component to the disk displacement.     

Surrogate disks for predicting cefotaxime and ceftriaxone susceptibilities of Streptococcus pneumoniae

Cefotaxime- and ceftriaxone-resistant Streptococcus pneumoniae is now appearing in some medical centers, but 30-micrograms cefotaxime or 30-micrograms ceftriaxone disks are not reliable for detecting such strains. Studies were undertaken to select another cephalosporin disk that might be used as a screening test that could be used in conjunction with a 1-micrograms oxacillin disk. A 30-micrograms cefuroxime disk is proposed: strains with zones > or = 28 mm in diameter are predictably susceptible to cefotaxime and ceftriaxone, and those with smaller zones should be further studied to confirm resistance to either drug. A 30-micrograms ceftizoxime disk may also be used as a screening test with zones > or = 26 mm indicating susceptibility, but cefuroxime disks are preferred.     

Encephalo-cranio-cutaneous lipomatosis (ECCL) -- Haberland syndrome. A case report with review of the literature]

Elastic properties of Xenopus oocytes were examined by measuring intracellular pressure (Pic) and cell volume (Vc) in cells undergoing osmotic swelling. Pic was measured by micropuncture, using the servo-null technique. Vc was obtained by analyzing images acquired from a microscope having a video camera attachment. During osmotic swelling, Pic increased from 61 +/- 17 to 500 +/- 59 Pa (mean +/- SE), but the relationship with volume was not linear. In cells that underwent sequential swelling and shrinking, Pic was always lower on shrinking and the cells showed hysteresis. Cells with vitelline envelope (VE) removed had Pic-Vc curves similar in shape to those of intact cells; however, Pic values were significantly lower. Specific elastance[delta Pic/(delta Vc/Vc)] was reduced by removal of the VE. The data indicate that oocytes are weakly elastic and that a large part of their resistance to expansion resides in the VE.     

Radioimmunoassay technology in mass drug screening: an evaluation of an absorbent paper disk transport system

These studies have demonstrated the feasibility of using urine-saturated paper disks in place of urine in the RIA system for drug abuse detection. Results with the disks are consistent with those using urine. A satisfactory procedure has been devised which provides reproducibility of results with no loss of sensitivity or specificity. Further, the procedure is essentially the same as the current procedure requiring urine except that a paper disk punched from a filter paper strip impregnated with urine is used. Complete flexibility is retained to switch from urine to disk. No new or additional equipment is required. It is envisioned that the urine would remain at the collection site and dried filter paper strips containing urine under test be shipped to toxicology laboratories. Sould the disk assay be positive, the urine specimen identified with that disk could then be shipped to the laboratory for confirmation by gas-liquid chromatography or other acceptable methods. The time and expense incurred in shipping large volumes of urine would thus be eliminated.     

The influence of observer calibration in temporomandibular joint magnetic resonance imaging diagnosis

OBJECTIVE: This study was undertaken to investigate the potential of reducing observer variation through a calibration program. STUDY DESIGN: The study was based on three sets of randomly selected temporomandibular joint magnetic resonance images. Each set consisted of bilateral images from 20 consecutive patients with temporomandibular disorders. As a baseline, three well-experienced noncalibrated investigators interpreted the images individually for disk position and disk configuration. After the initial interpretation, interobserver agreement was calculated as a kappa index and presented to the examiners. On the same occasion, the investigators analyzed agreement between them on the criteria to be used. RESULTS: Overall data in this study showed an increase in the frequency of interobserver agreement with regard to disk position after the calibration trials were instituted. With regard to disk configuration, substantial interindividual variations were observed even after the observers reached consensus as to the criteria to be used. CONCLUSIONS: These data suggest that after calibration trials, it is possible for three examiners to obtain reliable and reproducible results in reporting temporomandibular joint disk position on magnetic resonance images.     

Fluconazole disk diffusion susceptibility testing of Candida species

We describe a simple procedure for detecting fluconazole-resistant yeasts by a disk diffusion method. Forty clinical Candida sp. isolates were tested on RPMI-glucose agar with either 25- or 50-microgram fluconazole disks. With 25-microgram disks, zones of inhibition of >/=20 mm at 24 h accurately identified 29 of 29 isolates for which MICs were /=27 mm identified 28 of 29 such isolates. All 11 isolates for which MICs were >8 microgram/ml were identified by using either disk. Disk diffusion may be a useful screening method for clinical microbiology laboratories.     

Railroad wheels satisfying State Standard GOST 10791–2011

In the design of railroad wheels compliant with State Standard GOST 10791–2011, optimal selection of the disk and its dimensions remains a problem. Calculations for wheels based on curvilinear disks with a central camber show that the stress in the disks significantly exceeds the yield point of wheel steels. The replacement of the flat conical part of the disk with a curvilinear section based on a catenary curve reduces the stress in the disk, ensures a more uniform stress distribution, and results in a more competitive product.     

Thrombin enhances the adhesion and migration of human colon adenocarcinoma cells via increased beta 3-integrin expression on the tumour cell surface and their inhibition by the snake venom peptide, rhodostomin

The interactions between tumour cells and the microvasculature, including the adhesion of tumour cells to endothelium and extracellular matrix (ECM) as well as their migratory ability, are prerequisites for metastasis to occur. In this study we showed that thrombin is capable of enhancing in vitro tumour cell metastatic potential in terms of adhesive properties and migratory response. Following exposure to subclotting concentrations of thrombin, SW-480 human colon adenocarcinoma cells exhibited increased adhesion to both the endothelium and ECM component (i.e. fibronectin). Likewise, the pretreatment of thrombin enhanced the migratory ability of SW-480 cells. The enhanced adhesion was significantly inhibited by complexing of thrombin with its inhibitor hirudin, or by serine proteinase inhibition with 3,4-DCI, but was unaffected by pretreatment of tumour cells with actinomycin D or cycloheximide. The effect of thrombin resulted in an upregulated cell-surface expression of beta 3 integrins, a group of receptors mediating interactions between tumour cells and endothelial cells, and between tumour cells and ECM. Antibodies against beta 3 integrins effectively blocked both the enhanced adhesion and migration. This thrombin-mediated up-regulation of beta 3 integrins involved the activation of protein kinase C (PKC) as thrombin-enhanced adhesion was diminished by PKC inhibition. Rhodostomin, an Arg-Gly-Asp-containing antiplatelet snake venom peptide that antagonises the binding of ECM toward beta 3 integrins on SW-480 cells, was about 600 and 500 times, more potent that RGDS in inhibiting thrombin-enhanced adhesion and migration respectively. Our data suggest that PKC inhibitors as well as rhodostomin may serve as inhibitory agents in the prevention of thrombin-enhanced metastasis.     

Transanal self-expanding metal stents as an alternative to palliative colostomy in selected patients with malignant obstruction of the left colon

A QA test tool is designed to quantitatively measure the HDR source positioning error, and to facilitate quick and dependable HDR timer linearity test and daily output constancy check. The test tool consists of two concentric disks. The lower disk has a cutout for inserting an HDR catheter, and the upper disk accepts a diode or miniature ionization chamber and can rotate relative to the lower disk. Ionization readings from the source (transferred to the center of the disks) are obtained at two rotational positions of the upper disk which houses the detector. The ratio of the readings is used to determine the source-positioning error of the HDR unit relative to the nominal source position by a simple triangulation principle. Experimental measurements confirm that the QA test tool is sensitive to approximately 0.2 mm variance in source positioning errors. In addition, the QA test tool is suitable for other common HDR QA tests such as the source travel step size test, the daily HDR unit output constancy check, and the timer linearity test. Its simple and robust design permits routine clinical use and provides a high confidence level in the accurate operation of HDR units.     

Estimation of Minimum Working Capital for Construction Projects in Malaysia

Forecasting cash requirements is essential for all contractors during the tendering stage since cash flow at the beginning of the project is a major cause of construction companies’ failure. Unfortunately, estimating minimum working capital (MWC) is not the mainstream practice of the majority of contractors in Malaysia, who find that the present models for estimating MWC are cumbersome and seldom give an accurate estimate. Therefore estimates of MWC made during the tendering stage need to be simplified so they can be prepared quickly with minimum input. It is important for the developer or owner to select a qualified contractor with competent financial backing. This paper establishes the relationship among the factors that contribute to MWC requirements and presents a simple model that could be used as a guide to estimate MWC for housing construction projects in Malaysia. The estimation is based on percentages of variables of contract value based on the historical data that influence MWC; the MWC obtained is then expressed in terms of percentage of contract value.     

Why do we fail in aging the skull from the sagittal suture?

This study determined the variability of temporomandibular joint (TMJ) disk position in medial, central, and lateral aspects of the joint using magnetic resonance imaging (MRI). Subjects had clinical evidence of reciprocal TMJ clicking (N = 123) or restricted mandibular motion (N = 52). Eighty-nine asymptomatic volunteers provided a control group. Disk position was quantified on MRI by measuring the angle formed by a line through the middle of the condyle and perpendicular to the Frankfort plane and a line through the same midpoint of the condyle and tangential to the posterior-most aspect of the disk. The disk position in asymptomatic TMJs varied considerably with a tendency toward farther anterior placement in more lateral images. In 47 TMJs from a total of 52 TMJ5 (90%), restricted mobility was associated with anterior disk displacement (ADD) without reduction. The disk position demonstrated a mean displacement of 77 degrees without significant differences at the medial and lateral aspects of the condyle. One hundred TMJs from a total of 123 TMJs (81%) with reciprocal clicking demonstrated ADD with reduction. Tomograms revealed larger lateral displacements or rotational displacements in these joints, whereas medial images frequently showed similar ranges of disk positions as compared with asymptomatic TMJs. The results suggest that disk positions of up to +15 degrees on medial tomograms and +30 degrees on lateral tomograms should be regarded as normal variations. Furthermore, multisection analysis of all parasagittal images improved the separation between disk displacement and asymptomatic TMJs.     

Design of coolant disks for the production of amorphous alloys

The thermal operating conditions of coolant disks (without internal cooling) for the production of amorphous and microcrystalline strip are analyzed. The thermal balance conditions of the disk are calculated in producing strip of different width, at different melt flow rates. It is established that such disks may be used in small machines with the casting of 2 kg of metal per working cycle. To increase the mass of cast metal and the strip width, the disk diameter or the working surface area must be increased, while the melt flow rate from the nozzle and the disk speed must be reduced.     

Disruption of cell-cell adhesion in an inbred strain of hereditary cardiomyopathic hamster (Bio 14.6)

OBJECTIVE: Disarrangement of cardiomyocytes is a pathological characteristic of dilated cardiomyopathy. Hereditary cardiomyopathic hamster Bio 14.6, a model of dilated cardiomyopathy, displays disorder of cardiomyocyte arrangement. The aim of this study was to analyse the disturbance of cell alignment from the point of view of the cell-cell adhesion system in Bio 14.6. METHOD: Cardiomyopathic hamster Bio 14.6 was used as a model of dilated cardiomyopathy. Histological study was performed by light and electron microscopy. Disorder of the adherens junction-specific cell-adhesion molecule (A-CAM) was analysed by immunofluorescent microscopy and immunoblotting with anti-A-CAM antibody. RESULTS: Hematoxylin-eosin staining revealed that intercalated disks were identifiable less clearly in cardiomyopathy than in a normal cardiac muscle. It was disclosed by electron microscopy that cardiomyocytes adhered to each other with reduction in subsarcolemmal electron density at intercalated disks in Bio 14.6 compared with normal hamsters. We examined the localization of the A-CAM molecule in heart by immunofluorescent microscopy. In contrast to normal cardiac samples, fluorescence was weak in intensity and unclearly demarcated in the Bio 14.6 hamsters. We measured the content of A-CAM in the heart. In Bio 14.6 hamsters, the content of A-CAM was 60 +/- 11% of that measured in normal adult hamsters. A-CAM was reduced to a lesser extent (81 +/- 12%) in the newborn hamsters. CONCLUSIONS: In Bio 14.6 hamster, structural disturbance of the intercalated disks was found on histological examination of the heart. Biochemically, A-CAM, which plays a role in intercellular adhesion in intercalated disk areas, decreased significantly. These results suggest that cardiomyopathy may be accompanied by structural disruption of cell-cell adhesion in intercalated disk regions, which may lead to the pathological feature of disarranged cardiomyocytes.     

Hypersignal of the intervertebral disks in T1-weighted spin-echo MRI sequences

In magnetic resonance imaging, when there is calcification of the intervertebral disk, signals usually become weaker in all the sequences. Exceptionally, a spontaneous hypersignal is obtained in T1 weighted spin-echo sequences. We report 4 cases of spontaneous hypersignals from disks in T1 weighted spin-echo sequences. In 3 cases, calcifications were visualized with conventional radiology or computed tomography. In 1 case, there was no calcification of the disk, but its density, compared with adjacent disks, was 20 HU greater, suggesting inframacroscopic calcification.