Effects of basicity and MgO content on the viscosity of the SiO_2-CaO-MgO-9wt%Al_2O_3 slag system

The effects of basicity and MgO content on the viscosity of SiO2-CaO-MgO-9wt%Al2O3 slags with basicity from 0.4 to 1.0 and MgO content from 13wt%to 19wt%were investigated using the rotating cylinder method. A correlation between the viscosity and the slag structure was determined by Fourier transform infrared （FTIR） spectroscopy. It is indicated that the complex network structure of the slag melt is depolymerized into simpler network units with increasing basicity or MgO content, resulting in a continuous decrease in viscosity of the slag. The viscosity is strongly dependent on the combined action of basic oxide components in the slag. Under the present experimental conditions, increasing the basicity is found to be more effective than increasing the MgO content in decreasing the viscosity of the slag. At higher temperatures, the increase of basicity or MgO content does not appreciably decrease the viscosity of the slag, as it does at lower tem-peratures. The calculated activation energy of viscous flow is between 154 and 200 kJ＆#183;mol-1, which decreases with an increase in basicity from 0.4 to 1.0 at a fixed MgO content in the range of 13wt%to 19wt%.

Positron-emission tomography for hepatocellular carcinoma:Current status and future prospects

Hepatocellular carcinoma(HCC)is one of the leading causes of cancer mortality worldwide.Various imaging modalities provide important information about HCC for its clinical management.Since positron-emission tomography(PET)or PET-computed tomography was introduced to the oncologic setting,it has played crucial roles in detecting,distinguishing,accurately staging,and evaluating local,residual,and recurrent HCC.PET imaging visualizes tissue metabolic information that is closely associated with treatment.Dynamic PET imaging and dual-tracer have emerged as complementary techniques that aid in various aspects of HCC diagnosis.The advent of new radiotracers and the development of immuno-PET and PET-magnetic resonance imaging have improved the ability to detect lesions and have made great progress in treatment surveillance.The current PET diagnostic capabilities for HCC and the supplementary techniques are reviewed herein.

Risk factors for corticosteroid insufficiency during the sub-acute phase of acute traumatic brain injury

Hypothalamic-pituitary-adrenal axis dysfunction may lead to the occurrence of critical illness-related corticosteroid insufficiency.Critical illness-related corticosteroid insufficiency can easily occur after traumatic brain injury,but few studies have examined this occurrence.A multicenter,prospective,cohort study was performed to evaluate the function of the hypothalamic-pituitary-adrenal axis and the incidence of critical illness-related corticosteroid insufficiency during the sub-acute phase of traumatic brain injury.One hundred and forty patients with acute traumatic brain injury were enrolled from the neurosurgical departments of three tertiary-level hospitals in China,and the critical illness-related corticosteroid insufficiency incidence,critical-illness-related corticosteroid insufficiency-related risk factors,complications,and 28-day mortality among these patients was recorded.Critical illness-related corticosteroid insufficiency was diagnosed in patients with plasma total cortisol levels less than 10μg/dL(275.9 nM)on post-injury day 4 or when serum cortisol was insufficiently suppressed(less than 50%)during a dexamethasone suppression test on post-injury day 5.The results demonstrated that critical illness-related corticosteroid insufficiency occurred during the sub-acute phase of traumatic brain injury in 5.6%of patients with mild injury,22.5%of patients with moderate injury,and 52.2%of patients with severe injury.Traumatic brain injury-induced critical illness-related corticosteroid insufficiency was strongly correlated to injury severity during the sub-acute stage of traumatic brain injury.Traumatic brain injury patients with critical illness-related corticosteroid insufficiency frequently presented with hemorrhagic cerebral contusions,diffuse axonal injury,brain herniation,and hypotension.Differences in the incidence of hospital-acquired pneumonia,gastrointestinal bleeding,and 28-day mortality were observed between patients with and without critical illness-related corticosteroid insufficiency during the sub-acute phase of traumatic brain injury.Hypotension,brain-injury severity,and the types of traumatic brain injury were independent risk factors for traumatic brain injury-induced critical illness-related corticosteroid insufficiency.These findings indicate that critical illness-related corticosteroid insufficiency is common during the sub-acute phase of traumatic brain injury and is strongly associated with poor prognosis.The dexamethasone suppression test is a practical assay for the evaluation of hypothalamic-pituitary-adrenal axis function and for the diagnosis of critical illness-related corticosteroid insufficiency in patients with traumatic brain injury,especially those with hypotension,hemorrhagic cerebral contusions,diffuse axonal injury,and brain herniation.Sub-acute infection of acute traumatic brain injury may be an important factor associated with the occurrence and development of critical illness-related corticosteroid insufficiency.This study protocol was approved by the Ethics Committee of General Hospital of Tianjin Medical University,China in December 2011(approval No.201189).

^(18)F-FDG PET/CT in differentiating malignant from benign origins of obstructive jaundice

BACKGROUND： The various origins of obstructive jaundice make the diagnosis of the disease difficult. This study was undertaken to evaluate the role of 18F-FDG PET/CT in differentiating malignant from benign origins of obstructive jaundice and to quantify the added value of 18F-FDG PET/CT over conventional imaging（enhanced CT and/or MRI）.METHODS： Eighty-five patients with obstructive jaundice who underwent 18F-FDG PET/CT within 2 weeks after enhanced CT and/or MRI were reviewed retrospectively. All 18F-FDG PET/CT images were independently evaluated by 2 nuclear medicine physicians who were unaware of other imaging data; differences were resolved by consensus of the physicians. All conventional imaging interpretations, according to the medical records, were reviewed by 2 radiologists to determine the potential value. Final diagnoses were based on histological or surgical findings.RESULTS： Sixty-six patients were diagnosed with malignancies, and 19 patients with benign lesions. The maximum standardized uptake values for malignant and benign lesions causing biliary obstruction were 8.2±4.4 and 4.0±5.0, respectively（P〈0.05）. The sensitivity, specificity, and overall accuracy for differentiating malignant from benign origins with 18F-FDG PET/CT were 86.4%（57/66）, 73.7%（14/19）, and 83.5%（71/85）, respectively. 18F-FDG PET/CT in conjunction with conventional imaging changed the sensitivity, specificity, and overall accuracy of conventional imaging alone from 75.8%（50/66） to 95.5%（63/66）（P〈0.05）, 68.4%（13/19） to 57.9%（11/19）（P〉0.05）, and 74.1%（63/85） to 87.1%（74/85）（P〈0.05）, respectively.CONCLUSIONS： 18F-FDG PET/CT is of great value in differentiating malignant from benign origins of obstructive jaundice and is a useful adjuvant to conventional imaging. 18F-FDG PET/CT should be recommended for further etiological clarification.

Cooperative interception with fast multiple model adaptive estimation

For the case that two pursuers intercept an evasive target,the cooperative strategies and state estimation methods taken by pursuers can seriously affect the guidance accuracy for the target,which performs a bang For the case that two pursuers intercept an evasive target,the cooperative strategies and state estimation methods taken by pursuers can seriously affect the guidance accuracy for the target,which performs a bang-bang evasive maneuver with a random switching time.Combined Fast multiple model adaptive estimation(Fast MMAE)algorithm,the cooperative guidance law takes detection configuration affecting the accuracy of interception into consideration.Introduced the detection error model related to the line-of-sight(LOS)separation angle of two interceptors,an optimal cooperative guidance law solving the optimization problem is designed to modulate the LOS separation angle to reduce the estimation error and improve the interception performance.Due to the uncertainty of the target bang-bang maneuver switching time and the effective fitting of its multi-modal motion,Fast MMAE is introduced to identify its maneuver switching time and estimate the acceleration of the target to track and intercept the target accurately.The designed cooperative optimal guidance law with Fast MMAE has better estimation ability and interception performance than the traditional guidance law and estimation method via Monte Carlo simulation.

Screener3D:a gaseous time projection chamber for ultra-low radioactive material screening

In experiments searching for rare signals,background events from the detector itself are some of the major factors limiting search sensitivity.Screening for ultra-low radioactive detector materials is becoming ever more essential.We propose to develop a gaseous time projection chamber(TPC)with a Micromegas readout for radio screening.The TPC records three-dimensional trajectories of charged particles emitted from a flat sample placed in the active volume of the detector.The detector can distinguish the origin of an event and identify the particle types with information from trajectories,which significantly increases the screening sensitivity.For a particles from the sample surface,we observe that our proposed detector can reach a sensitivity higher than 100 l Bq m-2 within two days.

Instance selection method for improving graph-based semi-supervised learning

Graph-based semi-supervised learning is an important semi-supervised learning paradigm. Although graphbased semi-supervised learning methods have been shown to be helpful in various situations, they may adversely affect performance when using unlabeled data. In this paper, we propose a new graph-based semi-supervised learning method based on instance selection in order to reduce the chances of performance degeneration. Our basic idea is that given a set of unlabeled instances, it is not the best approach to exploit all the unlabeled instances; instead, we should exploit the unlabeled instances that are highly likely to help improve the performance, while not taking into account the ones with high risk. We develop both transductive and inductive variants of our method. Experiments on a broad range of data sets show that the chances of performance degeneration of our proposed method are much smaller than those of many state-of-the-art graph-based semi-supervised learning methods.

Effect of decompression range on decompression limit of cervical laminoplasty

Backgrounds:Cervical posterior decompression surgery is used to relieve ventral compression indirectly by incorporating a backward shift of the spinal cord, and this indirect decompression is bound to be limited. This study aimed to determine the decompression limit of posterior surgery and the effect of the decompression range.Methods:We retrospectively reviewed the data of 129 patients who underwent cervical open-door laminoplasty through 2008 to 2012 and were grouped as follows: C4-C7 ( n = 11), C3-C6 ( n = 61), C3-C7 ( n = 32), and C2-C7 ( n = 25). According to the relative location of spinal levels within a decompression range, the type of decompression at a given level was categorized as external decompression (ED;achieved at the levels located immediately external to the decompression range margin), internal decompression (ID;achieved at the levels located immediately internal to the decompression range margin), and central decompression (CD;achieved at the levels located in the center, far from the decompression range margin). The vertebral-cord distance (VCD) was used to evaluate the decompression limit. The C2-C7 angle and VCD on post-operative magnetic resonance images were analyzed and compared between groups. The relationship between VCD and decompression type was analyzed. Moreover, the relationship between the magnitude of the ventral compressive factor and the probability of post-operative residual compression at each level for different decompression ranges was studied. Results:There was no significant kyphosis in cervical curvature (>-5°), and there was no significant difference among the groups ( F = 2.091, P = 0.105). The VCD of a specific level depended on the decompression type of the level and followed this pattern: ED < ID < CD ( P < 0.05). The decompression type of a level was sometimes affected by the decompression range. For a given magnitude of the ventral compressive factor, the probability of residual compression was lower for the group with the larger VCD at this level. Conclusions:Our study suggests that the decompression range affected the decompression limit by changing the decompression type of a particular level. For a given cervical spinal level, the decompression limit significantly varied with decompression type as follows: ED < ID < CD. CD provided maximal decompression limit for a given level. A reasonable range of decompression could be determined based on the relationship between the magnitude of the ventral compressive factor and the decompression limits achieved by different decompression ranges.