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1.
The principle of the gearless drive has already been applied to some large mills. A synchronous motor is ``wrapped' directly around the mill cylinder and supplied by a thyristor frequency converter at approximately 10-percent system frequency. The drive thus operates at the low mill speed and dispenses with interposed gearing.  相似文献   
2.
In free tissue transfer and replantation surgery, there is a debate over whether any pharmacologic agents should be used to improve vessel patency and tissue survival. Because tissue-plasminogen activator (t-PA) is a highly effective and safe fibrinolytic, it may be useful in obtaining and maintaining vessel patency. The direct effects of t-PA on skeletal muscle hemodynamics and leukocyte activation at the microcirculatory level were investigated. Male Sprague-Dawley rats (n = 20) were divided into three experimental groups: control (n = 8), vehicle (n = 6), and t-PA (n = 6). Using the cremaster muscle flap model and intravital microscopy, red blood cell velocity, vessel diameter, capillary perfusion, endothelial edema index, and leukocyte-endothelial interactions (rolling, adhering, and transmigrating leukocytes) in postcapillary venules were measured. In the vehicle and t-PA groups, vehicle or t-PA was infused by means of a catheter inserted into the lower abdominal aorta for local infusion. Except for a significant reduction in the diameter of the first order arterioles from 117 microm to 82 microm (medians; p = 0.026), t-PA did not significantly affect red blood cell velocity, vessel diameter, or capillary perfusion compared with vehicle. However, leukocyte-endothelial interactions did differ significantly in postcapillary venules. Adhering leukocytes counted per visual field decreased from 4.67 in the vehicle group and 3.50 in the control group to 1.67 in the t-PA group (medians; p = 0.015 and p = 0.005, respectively); transmigrating leukocytes in the t-PA group decreased from 4.75 in the vehicle group and 3.50 in the control group to 1.67 in the t-PA group (medians; p = 0.002 and p = 0.043, respectively). t-PA treatment significantly decreased the number of both adhering and transmigrating leukocytes. These novel findings on leukocyte-endothelial interactions suggest that t-PA has anti-inflammatory effect.  相似文献   
3.
We report the case of a 54-year-old-man with alcoholic calcified chronic pancreatitis complicated by jaundice and abdominal pain. Investigations (Doppler ultrasonography examination and computed tomography scan) showed peripancreatic pseudoaneurysm of the posterior and inferior pancreatico-duodenal artery and a dilatation of the common bile duct. Selective embolization of the pseudoaneurysm resulted in rapid regression of both jaundice and abdominal pain. Common bile diet compression is a rare complication of peripancreatic pseudoaneurysm. Selective embolization seems to be the first line treatment in this indication.  相似文献   
4.
We report a quantitative analysis of the forces acting on optically trapped single gold nanorods. Individual nanorods with diameters between 8 and 44 nm and aspect ratios between 1.7 and 5.6 were stably trapped in three dimensions using a laser wavelength exceeding their plasmon resonance wavelengths. The interaction between the electromagnetic field of an optical trap and a single gold nanorod correlated with particle polarizability, which is a function of both particle volume and aspect ratio.  相似文献   
5.
A Mn-Zn ferrite ferrofluid is produced by chemical synthesis. Two different types of ferrofluids, according to the type of carrier liquid, are synthesized: an aqueous cationic ferrofluid and a surfacted hydrocarbon-based one. Ferrite particles are characterized by using several techniques: X-ray diffraction, transmission electronic microscopy, IR-spectroscopy, thermogravimetry, magnetization measurements and chemical analysis. Particles size depends on the synthesis parameters and can be partly controlled by choosing the type of the coprecipitating base. Increasing of the Zn concentration leads to smaller size of synthesized particles, as well as effects the content of associated water. Magnetization of the ferrofluid significantly decreases when the degree of Zn substitution exceeds 0.5.  相似文献   
6.
OBJECTIVE: To determine the frequency of patchy colonic involvement, fecal leukocytosis, and association with celiac sprue in a large cohort of patients with collagenous colitis. DESIGN: We conducted a retrospective review of the medical records of 172 consecutive Mayo Clinic patients in whom collagenous colitis had been diagnosed between 1982 and 1993. METHODS: For each of the 172 patients, the medical record was reviewed to determine the frequency of (1) fecal leukocytosis; (2) characteristic histologic findings in the rectum and the sigmoid, descending, and ascending colon; and (3) small bowel biopsy findings consistent with celiac sprue. RESULTS: The presence of fecal leukocytes was noted in 64 of 116 patients (55%) who had undergone assessment for fecal leukocytosis. On analysis of histologic findings, 113 of 123 rectal, 116 of 121 sigmoid, and 68 of 70 descending colon biopsy specimens were diagnostic of collagenous colitis. Small bowel biopsies were performed in 45 patients who did not have a history of small intestinal disease: 1 had celiac sprue and 44 had normal findings. Two other patients had previously diagnosed celiac sprue. CONCLUSION: The finding of fecal leukocytes in 55% of patients with collagenous colitis confirms the inflammatory basis of this disease. Biopsy specimens obtained by flexible sigmoidoscopy seem sufficient to establish the diagnosis in most patients, and colonoscopic biopsy of the more proximal area of the colon is usually unnecessary. Celiac sprue infrequently accompanies collagenous colitis; thus, routine small bowel biopsy is not warranted.  相似文献   
7.
We investigated whether linear whole-body acceleration along the interaural y-axis influenced the concurrent perception of visual motion direction as has been shown for angular accelerations. A sled running on air bearings along a 7.5-m track was used to accelerate 18 subjects at two different linear accelerations. These young, healthy volunteers, aged 25.50 +/- 7.38 years, used a joystick to indicate whether or not they perceived visual motion to the left within a random-dot kinematogram continuously presented on a monitor moving with them. The percentage of coherently leftward moving pixels presented for a 640-ms period during acceleration was adjusted according to a Modified Binary Search (MOBS) procedure. Six conditions were tested, two acceleration levels of 1 and 2 m/s2 to both left and right with, at the higher acceleration, two different times of visual motion presentation. Conditions were sequenced by means of a 6 x 6 Latin square balanced for order and carry over. A MANOVA did not show any statistically significant effects either for the independent variables acceleration, velocity, and direction of motion of the sled or for their interactions. The results obtained are in clear contrast to those obtained under rotatory stimulation. We conclude that the otolithic contribution to vestibular-visual motion processing is negligible.  相似文献   
8.
9.
We study the wavelength and polarization dependent plasmon resonances of single silver and gold nanorods, triangles, cubes, and dimers with a novel single particle spectroscopy method (RotPOL). In RotPOL, a rotating wedge-shaped polarizer encodes the full polarization information of each particle within one image. This reveals the symmetry of the particles and their plasmon modes, allows analyzing inhomogeneous samples and the monitoring of particle shape changes during growth in situ.  相似文献   
10.
150 practicing school psychologists (mean age 37.7 yrs) were surveyed to determine the reported current efforts of individual practitioners with regard to collecting accountability data (AD), uses that are made of the information, barriers to collecting AD, and relations between obtaining AD and various demographic variables. Results show that (1) 60% of the Ss were currently collecting AD; (2) enumerative, process, and outcome were the types usually collected; (3) approaches to collecting data were varied, but tabulation methods were the most common; and (4) approximately half of those collecting AD solicited it from administrators and teachers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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