Cerebral hemodynamics and oxygenation in preterm infants after low-vs. high-dose surfactant replacement therapy

In thirteen preterm infants receiving surfactant (Curosurf) replacement therapy, changes in cerebral hemodynamics and oxygenation were investigated by near infrared spectroscopy. Surfactant instillation led to an instantaneous increase in cerebral blood volume (CBV) in all infants, which was primarily due to an increase in deoxygenated hemoglobin. Five infants received a low dose (100 mg/kg = 1.25 ml/kg) of surfactant and 8 a high dose (200 mg/kg = 2.50 ml/kg). A significantly larger increase in CBV was observed in the infants receiving a high dose compared to those receiving a low dose of surfactant. We conclude that cerebral perfusion is affected more after the instillation of a high dose compared to a low dose of surfactant.     

The study of elongation and shear rates in spinning process and its effect on gas separation performance of Poly(ether sulfone) (PES) hollow fiber membranes

The influence of elongation and shear rates induced by the geometry of spinnerets on gas performance of PES hollow fiber membranes has been studied. Different elongation and shear rates were introduced in various spinnerets with flow angles of 60°, 75° and 90° by changing the flow rate of dope solution. The PES hollow fiber membranes were fabricated under the wet-spun condition without extra drawing force and their gas performances were tested by using O₂ and N₂. The flow profiles of dope solution and the elongation and shear rates at the outermost point of the outlet of spinnerets were simulated by the computational fluid dynamics model. A hypothetic mechanism is assumed to explain the effects of elongation and shear rates on the changes of conformation of polymer chain. While trying to correlate the elongation and shear rates with the gas performance of hollow fibers, we have come to some preliminary conclusions that the elongation rate has more contribution portion in permselectivity than in permeance and the shear rate has more contribution portion in permeance than in permselectivity.     

Investigation of mean glandular dose versus compressed breast thickness relationship for mammography

The relationship between the mean glandular dose (MGD) and the compressed breast thickness (CBT) is commonly used for the presentation of mammographic dose survey results and could also be useful for the assessment of individual breast doses retrospectively in case of lack of necessary dosimetric instrumentation. The high data scattering from the best fit reduces the reliability of this technique. The aim of this study was to investigate the accuracy of this relationship using the data collected from a patient survey and phantom experiment. Patients were divided into three different groups according to their breast glandularities, which were predicted from the inspection of previous mammograms. X-ray beam qualities that will be used in patient examinations were determined according to breast thickness and predicted glandularities. The MGD versus CBT relationship for all the examined patients resulted in a poor correlation (R(2) = 0.28). This relationship was separately obtained for each glandularity group and also for sub-groups of specific beam qualities. The best correlation (R(2) = 0.73) was obtained for the fatty breast group and Mo/Mo combination. A low correlation (R(2) = 0.34) was observed in the mid-glandularity group due to inclusion of a wide range of glandularities in this group. In the case of the dense breast group, although the glandularity range was narrow, there were e still high data scattering (R(2) = 0.25). This was probably due to the use of Mo/Rh and Mo/Mo combinations. This is validated by obtaining the MGD-CBT relationship specific to Mo/Mo combination (R(2) = 0.61).     

Thin Film Deposition of Semiconducting Ni-Co Oxide Spinel with Adequate Electrical and Optical Properties for Energy Application

Nickel-cobalt oxide with spinel structure was successfully fabricated using a wet chemical route followed by calcinations at 300 °C. In nickel-cobalt spinel oxide, Ni²⁺ ions occupy the octahedral sites and Co³⁺ ions are distributed over both octahedral and tetrahedral sites. Very interestingly, nickel-cobalt spinel oxide does not only show a p-type semi-conducting behavior material but also exhibits desired transparency in infrared wavelengths. Electrical and optical properties of the deposited films were investigated as a function of different processing conditions. The sputtering target is fabricated by homogeneously mixing oxide powders and followed by sintering at 1,500 °C. The nickel-cobalt oxide film showed a resistivity as low as 10^?2 Ω-cm by radio frequency (RF) magnetron sputtering in a pure oxygen atmosphere. The sputter-deposited nickel-cobalt oxide films also showed more than 70% transmittance in the infrared range.     

基于几何特征及C4.5的人脸美丽分类方法

从机器学习的角度来探索人脸美,提出与中国女性美丽程度相关的17维特征提取方法,然后运用C4。5分类树对不同美丽评分的人脸图像进行训练和测试。对510幅中国女性人脸图像的实验结果表明,文中提出的人脸美丽评价方法简单可行。对于美丽与否的两类别,平均分类精度达到94。1%。而对于4种美丽等级的分类,可达到71。6%的精度。研究表明通过合适的特征及C4。5机器学习来进行人脸美丽的智能感知是可行的。     

Precipitation behavior and strengthening effect in thermomechanical treatments of Al‐Zn‐Mg alloys

Abstract

An investigation was carried out to determine the precipitation behavior and strengthening effect in various thermomechanical treatments of Al‐Zn‐Mg alloys containing high Zn and low Mg contents. The results show that the precipitation behavior is largely influenced by a plastic deformation in the thermomechanical treatment, and the final precipitate and dislocation structures are greatly related to the influenced precipitation behavior; hence the strengthening effect is determined. Different alloy contents also cause different influences. A super‐strengthening occurs in the T‐AHA (80°C) treatment attributed to the optimum combination of dislocation and precipitate structure.     

Graphene surface-enabled lithium ion-exchanging cells: next-generation high-power energy storage devices

Herein reported is a fundamentally new strategy for the design of high-power and high energy-density devices. This approach is based on the exchange of lithium ions between the surfaces (not the bulk) of two nanostructured electrodes, completely obviating the need for lithium intercalation or deintercalation. In both electrodes, massive graphene surfaces in direct contact with liquid electrolyte are capable of rapidly and reversibly capturing lithium ions through surface adsorption and/or surface redox reaction. These devices, based on unoptimized materials and configuration, are already capable of storing an energy density of 160 Wh/kg(cell), which is 30 times higher than that (5 Wh/kg(cell)) of conventional symmetric supercapacitors and comparable to that of Li-ion batteries. They are also capable of delivering a power density of 100 kW/kg(cell), which is 10 times higher than that (10 kW/kg(cell)) of supercapacitors and 100 times higher than that (1 kW/kg(cell)) of Li-ion batteries.     

A novel partitioning method as a possible tool for investigating meat. I.

 This paper describes a practical application of the interfacial protein enrichment method, called three-phase partitioning (TPP), and outlines its significance in the differentiation of multicomponent protein systems, such as homogenates and drips of different meats (pork, beef, chicken, turkey and wild-boar). The results obtained using the single-protein model system are also reported to demonstrate the basic process and some characteristic features of TPP. For meat-protein-partitioning experiments, ammonium sulphate (41% relative saturation) and 23.7% tert-butanol were used at 20 – 25°C. Using this two-liquid system, a characteristic distribution of three phases (including a semi-solid midlayer) was obtained for homogenates of eight different meats following centrifugation. Compressibility, expressed as a ratio of layer thickness obtained by low-speed (200 g) and medium-speed (4500 g) centrifugation, allowed us to distinguish between beef and pork drips. A good correlation was found between layer thickness and storage time for wild-boar samples. The partitioning presented here can be considered as a rapid and simple method for comparison between raw meat samples of different origin. Received: 9 July 1997 / Revised version: 1 October 1997     

Fabrication of high breakdown voltage silicon Schottky barrier diodes using various edge termination structures

In this work, the design and fabrication of Au/n-Si Schottky barrier diodes (SBDs) with various edge termination schemes, including a reduced-surface-field-type lateral super-junction, a polycrystalline silicon (poly-Si) floating ring, and a p⁺-poly-Si guard ring, are presented. Experimental results show that the reverse leakage current of the proposed SBDs was reduced and the breakdown voltage increased with an increase of the poly-Si width of the guard ring.It was found that the device and fabrication technology developed in the present study is applicable to the realization of SBDs with a high breakdown voltage (≥ 160 V), a low reverse current density (≤ 5.6 μA/cm²), a low forward voltage drop (≤ 5.6 V @ 1 A/cm²), and an adjustable Schottky barrier height of 0.764 to 0.784 eV.     

The triterpenoids of Ganoderma tsugae prevent stress‐induced myocardial injury in mice

Ganoderma mushrooms (Lingzhi in Chinese) have well‐documented health benefits. Ganoderma tsugae (G. tsugae), one of the ganoderma species, has been commercially cultivated as a dietary supplement. Because G. tsugae has high antioxidant activity and because oxidative stress is often associated with cardiac injury, we hypothesized that G. tsugae protects against cardiac injury by alleviating oxidative stress. We tested the hypothesis using a work‐overload‐induced myocardial injury model created by challenging mice with isoproterenol (ISO). Remarkably, oral G. tsugae protected the mice from ISO‐induced myocardial injury. Moreover, the triterpenoid fraction of G. tsugae, composed of a mixture of nine structurally related ganoderic acids (GAs), provided cardioprotection by inhibiting the ISO‐induced expression of Fas/Fas ligand, oxidative stress, and apoptosis. The antioxidant activity of GAs was tested in cultured cardio‐myoblast H9c2 cells against the insult of H₂O₂. GAs dissipated the cellular reactive oxygen species imposed by H₂O₂ and prevented cell death. Our findings uncovered the cardioprotective activity of G. tsugae and identified GAs as the bioactive components against cardiac insults.