Evaluation of selenium in biological sample of arsenic exposed female skin lesions and skin cancer patients with related to non-exposed skin cancer patients

The antagonistic effects between selenium (Se) and arsenic (As) suggest that low Se status plays an important role in arsenism development. The objective of present study was to assess Se contents in biological samples of As exposed females have skin lesions and cancer with related to non-exposed skin cancer patients. The biological samples (blood and scalp hair) of As exposed group comprises, female skin cancer (ESC) patients admitted in cancer hospitals have skin lesions (ESL) and exposed referents have not both diseases (ER), belongs to As exposed area of Pakistan. For comparative purposes, age matched female skin cancerous patient (RP) and non-cancerous females (NER) belong to non-exposed areas were also selected. The As and Se in acid digests of biological samples were pre-concentrated by complexing with chelating agent (ammonium pyrrolidinedithiocarbamate), and resulted complexes were extracted into non-ionic extractant (Triton X-114), prior to analysis by electrothermal atomic absorption spectrometry. The enhancement factor of about 25 was obtained by pre-concentrating 10 mL of sample solutions. The accuracy of the optimized procedure was evaluated by using certified reference material (BCR 397) with certified values for Se and As and standard addition method at three concentration levels in real samples. No significant differences was observed (p > 0.05) when comparing the values obtained by the proposed method, added and certified values of both elements. The biological samples of ESC patients had 2-3 folds higher As and lower Se levels as compared to RP (p < 0.001). Understudied exposed referents have high level of As and lower Se contents as compared to referents subjects of non-exposed area (p < 0.01). The higher concentration of As and lower levels of Se in biological samples of cancerous patients are consisted with reported studies.     

Stabilization of sheet resistance for metal lines by formation of etch stop layer (ESL) trench structure

Sheet resistance of metal lines is mainly affected by critical dimension (CD), etch depth, and chemical mechanical planarization amount in damascene process. Therefore, these factors must be stably controlled in order to stabilize the sheet resistance of metal lines. Especially the etch depth, which is sensitive to the pattern density and the equipment conditions bring not only the variation of sheet resistance of metal lines but also the connection problem to the under-layered contacts. The objective of this study is to reduce the variation of the sheet resistance of metal lines by stabilization of the etch depth with etch stop layer (ESL). SiN film was used as an ESL while the intermetal dielectric (IMD) films were employed by the conventional fluorine-doped silicate glass (FSG)/SiH₄ film with an increment of thickness by the employment of SiN film as an ESL. The selectivity of oxide-to-nitride was about 6.4:1 for etch stop step. While the stop layers were removed after the etch stop step, the pre-metal dielectric was also etched at the same time for the stable connection to the under-layered contacts. Comparing the ESL method to the conventional method, more stable metal lines were formed with the in-line CD measurement, thickness measurement, cross-sectional scanning electron microscopy analysis, and sheet resistance measurement from the view point of the connection to the under-layered contacts. The stable sheet resistance of metal lines was also obtained with the changes in etch time or thickness.     

Real-time automated register abstraction active power-aware electronic system level verification framework

All modern low power system on a chip (SoC) architectures are equipped with an in-built power management system. Every new system is expected to have more features and lower power consumption, resulting in a continuous demand to improve energy efficiency. To cope up with the ever increasing demand, an active power-aware management verification architecture is necessary to minimize the power consumption. Power reduction techniques include clock-gating, power-gating, multi-voltage, and voltage-frequency scaling. The proposed verification architecture utilizes the Unified Power Format (UPF) 2.1 libraries to achieve early design verification at the Electronic System-Level (ESL) of abstraction. The proposed testbench can verify several designs of different power management schemes. The presented work offers a reduction in power states, CPU time and simulation time as compared to existing techniques. The interactive formal and simulation-based verification methods are used in this paper to remove the simulation artifacts during functional and power co-simulation. Additionally, this paper incorporates functional correctness and power-aware checks for different modules of Design Under Verification (DUV) at Transaction-Level Modeling (TLM).     

原料乳微生物特性对ESL牛乳货架期影响的研究

研究了ESL乳生产过程中对原料乳质量的要求。结果表明,ESL乳的生产中,在保证原料乳细菌总数≤5×105mL-1时,原料乳中的芽孢数应控制在≤5×103mL-1,同时,应选取低温菌数量和体细胞数量都较低的原料乳。     

陶瓷膜微滤技术生产ESL牛乳的应用研究

对Membralox GP1．4μm陶瓷膜在脱脂牛奶除菌过程中的应用进行了实验研究。在原料温度50℃、浓缩倍数(VCR)为20的条件下，连续过滤6．5h，过膜压力(TMP)和流量基本保持恒定，细菌分离效率大于5；确定了膜的操作条件和再生方式，结果表明，膜过滤的牛奶采用不同的温度杀菌后无菌包装，货架期显著延长。应用膜过滤技术可生产延长货架期(ESL)牛奶。     

Cognitive–linguistic foundations of early spelling development in bilinguals.

Developing spelling skills in English is a particularly demanding task for Chinese speakers because, unlike many other bilinguals learning English as a second language, they must learn two languages with different orthography as well as phonology. To disentangle socioeconomic and pedagogical factors from the underlying cognitive–linguistic processes that predict the development of spelling, we used a 6-month longitudinal design and compared children with English as their first language (English-L1; n = 50) and children with Mandarin as their first language (Mandarin-L1; n = 50) from the same kindergarten. Both groups were tested on parallel versions of English and Mandarin tasks as predictors at Time 1, and their spelling sophistication scores were then computed from a 52-item experimental task administered at Time 2. After we controlled for nonverbal IQ, age, vocabulary, and spelling achievement on Wide Range Achievement Test 4 at Time 1, regression analyses showed that phoneme awareness was the strongest predictor of spelling sophistication for English-L1 children, but syllable awareness and letter-sound knowledge were also important for Mandarin-L1 children. The implications of these differences in the cognitive–linguistic processing of bilingual children learning two dissimilar languages are briefly discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

走向“顶峰”：零售业中的双稳态LCD

早期的标准扭曲向列相分段显示LCD电子货架价签卡只能更新价格。控制信息显示量,可以在持续使用中极大地降低电池驱动显示屏的能耗,这满足了一部分零售商对低能耗的需求。而双稳态被动矩阵显示屏不仅可以为零售商提供更多的信息,电池还可以使用数年。文章讨论了双稳态LCD和RF整合的技术,旨在为零售商提供更强的功能性和便利性。     

如何提高英语听力课堂的教学效果

如何掌握准确而有效的听力技能已成为英语教学中的重要问题。本文旨在讨论一些影响英语听力课教学质量的因素以及如何通过对上述因素的控制和改善来提高英语听力课堂的教学效果,从而提高学习者的听力理解能力。     

基于ESL的MEPG-4解码SoC软硬件协同设计

随着SoC(System on Chip)系统设计复杂度的不断提高,设计前期在系统级别进行软硬件规划对SoC 性能的影响日趋增加,在复杂视频解码SoC 设计中迫切需要高效的性能分析和验证平台从架构层次上优化性能.将基于电子系统级设计(Electronic System Level , ESL)仿真方法在MPEG-4 视频解码SoC 软硬件协同设计中的应用,利用ARM SoC-Designer ESL 平台分析软件算法的瓶颈,实现软硬划分.通过SystemC 对硬件单元周期精确建模,最终实现了MEPG-4 解码软硬件协同仿真验证.实践证明利用ESL 进行系统设计不仅可以有效提高仿真速度而且设计的视频解码硬件能有效改善系统的性能.     

脉宽扩展型脉冲电源的研究

随着脉冲功率技术的持续不断发展,其在国防建设以及国民生产中的应用越来越广泛,为了满足电磁发射技术的需要,高精度的脉冲电源系统是必不可少的,基于国内外在高功率电容器,晶闸管和续流二极管及脉冲放电网络最新的研究基础上设计了一个小型的紧凑型脉冲功率电源,并采用pspice对脉冲电源的各个部件进行了理论研究和系统的仿真分析验证。为了满足轨道炮放电所需要的恒定持续的大电流,探讨和改进了两种脉宽扩展型放电网络,经过仿真分析,其能够很好地时序触发,并且电流的输出波形很好地满足了轨道炮的要求。最后对两种放电网络进行了仿真比较分析。