Evaluating the mixing performance of a ribbon blender

This paper investigates the effects of processing and equipment parameters of a ribbon blender (i.e. loading method of lubricant, fill level, blade speed and blade design) on magnesium stearate homogeneity. A core sampling technique is used to obtain at least one hundred samples per sampling event, which are extracted throughout the blender and yield a thorough characterization of the entire bed. The results presented here can be used as a guideline to develop appropriate blending processes and characterization protocols for ribbon blenders.     

Interleukin-2 enhancement of cytotoxicity by humanized monoclonal antibody M195 (anti-CD33) in myelogenous leukemia

The mass childhood immunization programme has traditionally been viewed as a safe and effective preventative measure by health promoters, primary health care professionals and governments. This consensus has meant that immunization has rarely been viewed as ethically problematic. A number of recent changes in the context of the delivery of health care, particularly the emphasis on consumerism and the effect of the marketization of services, makes timely an examination of ethical, social and political issues. This article examines four main grounds for problematizing the mass childhood immunization programme. These are: clinical research evidence about the safety and efficacy of vaccines; the masking of wider social and political determinants of ill health; the contradictory strictures about collective and individual rights in relation to immunization; and the uniqueness of childhood immunization as a physical intrusion into a healthy body. The implications of these ethical issues are discussed in relation to informed consent and the need for a 'greenfield' review that includes the views of dissenting parents, lawyers and moral philosophers, as well as health professionals.     

Identification and characterization of a cDNA encoding ribosomal protein S12 from Xenopus laevis

LY171883, a peroxisome proliferator and leukotriene D4-antagonist, induced a statistically significant increase in the number of hepatic lesions in B6C3F1 female mice in a 2 year oncogenicity study at dietary doses of 0.0225% and 0.075%. The mutation frequency and spectrum of the 61st codon of H-ras was determined for 64 independent, archived lesions from the LY171883 2 year oncogenicity study using the polymerase chain reaction (PCR), allele specific oligo hybridization (ASO) and DNA sequencing. Results showed 41 (64%) of these lesions had mutations at the 61st codon (16/21 hepatocellular carcinomas, 4/10 hepatocellular adenomas, 19/26 focal hepatocellular hyperplasias and 2/7 focal hepatocellular atypia). These mutations consisted of 18 C-A transversions, 16 A-G transitions and seven A-T transversions. Compared to the mutation frequency for spontaneously occurring archival B6C3F1 hepatic lesions (41%), the frequency of LY171883 lesions (64%) was significantly higher (P < 0.01). The frequencies of H-ras 61st codon mutations among the LY171883 lesion types (hepatocellular carcinomas 76%, hepatocellular adenomas 40%, focal hepatocellular hyperplasias 73% and hepatocellular atypia 29%) were also significantly different (P = 0.035). In contrast, spontaneous lesions showed no statistical difference in the frequencies of mutation among lesion types (P > 0.5). The mutation spectrum of the LY171883 lesions was not significantly different from the spontaneous spectra. It may be concluded that based on the similarity in mutation spectrum and the increase in mutation frequency, LY171883 may selectively promote spontaneous hepatic lesions containing H-ras 61st codon mutations. In addition, the difference in mutation frequency among lesion types does not support a linear progression of all LY171883 lesions through focal atypia, focal hepatocellular hyperplasias, hepatocellular adenomas and hepatocellular carcinomas.     

品牌换标启示录

近几年国内外许多大品牌纷纷更换自己的标志，从柯达、富士到英特尔，从中国联通到腾讯网，从联想到创维，再到华为等，那么导致品牌换标的原因是什么？标志的再设计在其中起到一个怎样的作用？     

Coexisting static and flowing regions in a centrifuging granular heap

We report an unexpectedly rich variety of new flow patterns on a granular heap that is centrifuged so as to simulate a reduction in gravity. These surface patterns exhibit coexisting static and flowing regions that depend strongly on centrifugal stress, but surprisingly not on mass flow rate. A discrete cellular automata model reproduces some of the patterning features and indicates that subsurface jamming may precipitate the formation of localized frozen patterns on the surface. This model provides insights into the mechanics of granular flows under controlled stress environment and jammed-to-flowing transitions in granular media.     

Image compression in digital mammography: effects on computerized detection of subtle microcalcifications

Our previous receiver operating characteristic (ROC) study indicated that the detection accuracy of microcalcifications by radiologists is significantly reduced if mammograms are digitized at 0.1 mm x 0.1 mm. Our recent study also showed that detection accuracy by computer decreases as the pixel size increases from 0.035 mm x 0.035 mm. It is evident that very large matrix sizes have to be used for digitizing mammograms in order to preserve the information in the image. Efficient compression techniques will be needed to facilitate communication and archiving of digital mammograms. In this study, we evaluated two compression techniques: full frame discrete cosine transform (DCT) with entropy coding and Laplacian pyramid hierarchical coding (LPHC). The dependence of their efficiency on the compression parameters was investigated. The techniques were compared in terms of the trade-off between the bit rate and the detection accuracy of subtle microcalcifications by an automated detection algorithm. The mean-square errors in the reconstructed images were determined and the visual quality of the error images was examined. It was found that with the LPHC method, the highest compression ratio achieved without a significant degradation in the detectability was 3.6:1. The full frame DCT method with entropy coding provided a higher compression efficiency of 9.6:1 at comparable detection accuracy. The mean-square errors did not correlate with the detection accuracy of the microcalcifications. This study demonstrated the importance of determining the quality of the decompressed images by the specific requirements of the task for which the decompressed images are to be used. Further investigation is needed for selection of optimal compression technique for digital mammograms.     

The late results of the surgical treatment of patients with a pathologically mobile kidney

Long-term (1-10 years) results of wandering kidney surgery were followed-up for 118 patients. The outcomes were found dependent on the duration of the disease, variety and severity of the lesion, age of the patients. The response appeared better in younger patients, in those with shorter duration of the disease and with unessential changes in the kidney. Recommendations are provided on the regimens, jobs, outpatient and inpatient follow-up for the subjects treated surgically for wandering kidney to reinforce the correction results achieved.     

FR139317, a specific ETA-receptor antagonist, inhibits cerebral activation by intraventricular endothelin-1 in conscious rats

A comprehensive series of time-related behavioral, physiological and cerebral metabolic studies was conducted using conscious Sprague-Dawley rats to discern the anti-endothelin (ET) properties of the specific ETA receptor antagonist, FR139317. Endothelin-1 (9 pmol given by injection into one lateral ventricle, i.c.v.) produced convulsions, acute arterial hypertension, arterial hyperglycemia, and hyperventilation. Brain structures close to the i.c.v. site of injection, such as the caudate nucleus, lateral septal nucleus, corpus callosum and hippocampal CA3 medial lamellae, as well as 14 other individual structures, displayed moderate-to-intense levels of metabolic activation after endothelin. Data were assessed quantitatively by means of the autoradiographic [14C]deoxyglucose technique combined with image analysis. Neural circuits in the efferent projection paths of the stimulated forebrain structures, such as the midbrain oculomotor complex, amygdaloid nuclei, substantia nigra pars reticulata and caudal subicular subregions of the hippocampal formation, were stimulated focally by endothelin. Specific medullary nuclei and cerebellar cortical subregions displayed high rates of glucose metabolism following endothelin injection at the time of maximum behavioral and physiological stimulation. I.c.v. treatment with > or = 14 nmol FR139317 before endothelin significantly inhibited the effects produced by the peptide. At the highest dose of FR139317 (28 nmol), there was only mild behavioral stimulation following endothelin injection, and hypermetabolic responses in the brain were abolished except in two specific areas of the cerebellar cortex (approx 40% increases in metabolic activity in the copula pyramis and paramedian lobule). The results indicate that the cerebral stimulatory effects of i.c.v. endothelin are mediated by the A type of endothelin receptor. By itself, i.c.v. FR139317 had no effects on the parameters assessed. Further evaluation of FR139317 is warranted as a possible therapeutic agent for neuropathologies suspected of deriving from central neural or vascular stimulation by endothelin, such as aneurysmal vasospasm, ischemia, excitotoxicity, and peptide-mediated epilepsies.     

On the evaluation of the J-integral by a plastic crack tip element

Two crack tip elements are formulated for a stationary, mode I plastic crack in planar structures using hybrid assumed stress approach, based on the secant modulus and the Newton-Raphson schemes, respectively. The stress distribution in the crack tip element is assumed to be the HRR field superimposed by the regular polynomial terms. The formulated (hybrid) crack tip elements are compatible with the isoparametric element so that they can be used conveniently along with the conventional displacement-based finite elements. The intensity of the HRR stress field, the J-integral, is determined directly from the finite element equations together with the nodal displacements. The dominance of the HRR stress field at the crack tip is pertinent to the present approach, which depends on geometry and loading conditions. Since the J-integral is globally path-independent for nonlinear elastic materials (deformation plasticity model), in order to assess the accuracy and efficiency of the methodology as compared to the contour integration approach, numerical studies of common plane-stress cracked configurations are performed for these materials. The results indicate that for a sufficiently small crack tip element size, J from the present approach correlates well, within 6 percent difference, with that from the contour integration for a wide range of material hardening coefficients if the HRR zone exists at the crack tip. These highly accurate results for J from the crack tip stresses could not be achieved without using (newly) modified variational principles and a refined numerical technique. It should be emphasized that the present methodology also can be applied to cracks in J ₂ flow materials under HRR dominance. In such case, the J integral may not be globally path independent, and hence it now must be determined from the stress and strain fields near the crack tip.