Pediatric percutaneous endoscopic jejunostomy by J-tube extension through a preexisting gastrostomy site: a preliminary report

A prematurely born 5-year-old boy with chronic lung disease, hypoxic-ischemic encephalopathy, cerebral palsy, repeated aspiration pneumonia, and stroke underwent percutaneous endoscopic jejunostomy (PEJ) to alleviate repeated aspiration pneumonia. Studies, including 24-hour esophageal pH monitoring, 99mTc gastric emptying time, upper gastroesophageal barium radiography, and endoscopic examinations showed severe gastroesophageal reflux and prolonged gastric emptying. Percutaneous endoscopic gastrostomy (PEG) was performed first, followed by placement of a polyurethane J-tube (9 French) through the preexisting gastrostomy site. We passed the style-guided J-tube through the pyloric ring endoscopically and advanced it to the jejunum. The position of the J-tube was confirmed by radiologic study. Feeding with an elemental formula, 20 mL/hour, commenced immediately after the procedure, and the rate was gradually increased to 50 mL/hour. No further episodes of aspiration pneumonia have occurred since J-tube placement. Our initial experience with jejunal feeding through a PEJ is encouraging.     

A major T cell determinant from the influenza virus hemagglutinin (HA) can be a cryptic self peptide in HA transgenic mice

A single low dose of the neurotoxin: 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) results paradoxical sleep deprivation and reduction in food intake without any detectable motor deficiencies. In the present study we monitored the in vivo extracellular levels of monoamines and their metabolites following intraperitoneal (i.p.) administration of a single dose of MPTP (5 mg/kg). Microdialysates were collected from the ventrobasal thalamic nucleus (VB) of Halothane anesthetized rat. We found a significant decrease in noradrenaline (NA), 3,4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindoleacetic acid (5-HIAA) levels and a significant increase in 3,4-dihydroxyphenylalanine (DOPA) concentration whereas amino acid levels were unchanged throughout the 4-hour long perfusion. We found no significant difference in the post mortem release of NA and DOPA between the control and MPTP treated animals, suggesting that the intracellular NA pool were maintained. The above findings support the idea that the neurochemical mechanism of rapidly developing and transient behavioral changes induced by MPTP may be an immediate decrease in monoaminergic transmission and metabolism following MPTP injection.     

Characteristics and so2 capture capacities of sorbents prepared from products of spray-drying flue gas desulfurization

The characteristics and the SO₂ capture capacities of sorbents prepared from products of spray-drying flue gas desulfurization (FGD) have been studied. Sorbents were prepared by first slurrying Ca(OH)₂ and CaSO₃ and/or CaSO₄ with and without the addition of fly ash and then drying. Compared to the use of pure Ca(OH)₂, the SO₂ capture and Ca(OH)₂ utilization decreased for sorbents prepared without fly ash and increased for sorbents with fly ash. Flakelike ill-crystallized tobermorites were observed for all the sorbents containing fly ash. In addition, significant amounts of needle-shape Ca₄Al₂(OH)₁₂SO₄ . 6H₂O and Ca₆Al₂ (OH)₁₂(SO₄)₃ . 26H₂O (ettringite) were also observed for the sorbents containing CaSO₃ and/or CaSO₄. These newly formed compounds dissociated into CaSO₃ . 0.5 H₂O and inert precursors upon sulfation, and were responsible for the high SO₂ capture capacities and Ca(OH)₂ utilizations of the sorbents prepared with fly ash.     

Optical properties of InAs<Subscript>1−x</Subscript>N<Subscript>x</Subscript>/In<Subscript>0.53</Subscript>Ga<Subscript>0.47</Subscript>As single quantum wells grown by gas source molecular beam epitaxy

Optical properties of InAs_1−xN_x/In_0.53Ga_0.47As (hereafter, abbreviated as InAsN/InGaAs) single quantum wells (SQWs) grown on InP substrates by gas source molecular-beam epitaxy are studied using photoluminescence (PL) measurements. By comparing the low-temperature PL spectra of InAs/InGaAs and InAsN/InGaAs SQWs, InAs and InAsN phases are found to coexist in the InAsN layer. Such serious alloy inhomogeneities result in obvious exciton localization by potential irregularities. The blue shift of the PL peak after rapid thermal annealing (RTA) is found to originate mainly from As-N interdiffusion inside the well layer. According to the temperature-dependent PL results, uniformity of the InAsN layer can be effectively improved by RTA, and the exciton localization is, thus, relieved. Comparison of luminescence quenching and excitation-power-dependent PL behavior between the QWs with and without nitrogen content suggests that the quality of the QW is degraded by the introduction of nitrogen, and the degradation can only be partially recovered by post-growth RTA.     

Highly Visible Photocatalytic Activity of Fluorine and Nitrogen Co-doped Nanocrystalline Anatase Phase Titanium Oxide Converted From Ammonium Oxotrifluorotitanate

The formation of high-quality fluorine and nitrogen co-doped nanocrystalline anatase phase titanium oxide converted from ammonium oxotrifluorotitanate discoid crystal by means of thermal treatment is reported in this study. The decomposition rate of methylene blue under 450 nm light-emitting diode illumination demonstrates an excellent visible photocatalytic activity. The highest visible photocatalytic activity is obtained at the thermal treatment temperature of 600 degC. We confirm the positive roles of fluorine and nitrogen in titanium oxide in the area of visible photocatalytic activity. There is one-to-one correspondence between the life of an electron and hole pair and photocatalytic activity     

Two-Stage pyrolysis model of PVC

The pyrolysis of polyvinyl chloride (PVC) was examined with a thermal gravimetric analyzer (TGA). The experiments were carried out over the temperature range of 400-800 K at three heating rates of 1, 2, and 5.5 K/min and in a nitrogen atmosphere. The results indicate that the entire process of PVC pyrolysis under the experimental conditions of this investigation consists of two distinct pyrolysis stages, namely, the thermal dehydrochlorination and the breakdown of the intermediate products produced after the dehydrochlorination stage. The corresponding activation energy, pre-exponential factor, and reaction order were determined. A two-stage pyrolysis model, which is composed of four reactions including a number of independent, consecutive and competitive reactions with volatiles and solid products, was developed. This kinetic model gives good agreement with the experimental results.     

Strategy for the expansion of an existing steam rankine cycle to A combined cycle

A systematic procedure for designing an expansion of the steam Rankine cycle to a combined cycle is proposed. This paper discusses the approach from the point of view of overall thermodynamic efficiency. Practical limitations in design considerations are also addressed. The application of this approach is illustrated with a typical utility system design.     

Short-channel MOSFETs with oxynitride gate dielectrics fabricated using multiple rapid thermal processing

Short-channel MOSFETs with superior thin gate dielectrics have been successfully fabricated using multiple reactive rapid thermal processing of thermal oxides. The gate dielectrics are produced by rapid thermal nitridation (RTN) of thin thermal oxides in pure NH/sub 3/ ambient followed by rapid thermal reoxidation (RTO) in O/sub 2/ ambient. Devices fabricated with RTO/RTN gate dielectrics exhibit improved hot electron induced degradation compared to those fabricated with pure oxides. In addition, the subthreshold leakage current level of RTO/RTN devices is as good as for standard oxide devices.<>     

基于压缩感知的AOTF光谱测量方法（英文）

基于声光可调谐滤波器（AOTF）的光谱仪器已经在生物医学、农业、航空航天等领域中广泛应用。然而,传统的AOTF光谱仪很难在保持光谱分辨率和减少采样次数的同时,还实现系统光通量的增加。针对上述问题,本文提出了一种基于压缩感知理论的AOTF光谱测量方法,利用AOTF可多频驱动的特点,在光谱维度上实现稀疏随机编码复合光信号调制,可利用单元或面阵探测器顺次记录完成压缩采样,再通过压缩感知重建算法获得目标光谱曲线或光谱图像数据立方体。为了验证本方法的有效性,我们利用实际测量得到AOTF光谱响应带宽数据,构建传感矩阵,以展宽光谱为恢复目标,仿真了压缩采样和目标数据重构效果。仿真结果表明,该方法可以通过202次压缩采样,重构得到512个波长点的光谱数据,光谱数据采样率和压缩比为0.39。此采样率下,本方法可以高精度恢复光谱曲线,PSNR指标达到41.75dB,SAM和GSAM指标为0.9998和0.9754。多频同时驱动下,系统光通量平均提升了5倍。与传统逐波长点扫描的采样方式相比,该方法能够在保持原有光谱分辨率的前提下减少总采样次数,提高系统的光通量,同时还压缩了光谱数据,在微弱信号检测、物质快速...     

Spatial filtering of first-arriving light

The effect of combining low-pass spatial filtering with the first-arriving-light method for imaging through a scattering medium was investigated. The modification is highly effective for media having a significant specular transmission component but is essentially ineffective for media without a specular component.