Synchrotron X-Ray Microdiffraction Investigation of Scaling Effects on Reliability for Through-Silicon Vias for 3-D Integration

Synchrotron x-ray microdiffraction has been applied to TSV characterization in various studies for nondestructive inspection with submicron resolution due to its high beam intensity and penetration depth. In this paper, the application of this technique to TSV investigations is examined and the correlation of the plastic deformation to the microstructure and extrusion behavior along with the effect of TSV dimensional scaling is examined. It is shown that the variability of the copper microstructure and resulting TSV behavior requires a larger number of samples in order to report statistically significant observations. The role of the microstructure in creating statistical scatter is demonstrated through microdiffraction measurements of grain orientation correlated with the observed peak widening, which shows that degraded TSV reliability is largely due to the high elastic anisotropy of copper. After taking the statistical variations into account, the scaling effect was clearly observed, with larger plastic deformation in 2μm diameter TSVs than in 5μm diameter TSVs consistent with microstructure variations. This is confirmed by TSV extrusion measurements, which show that the magnitude and statistical spread of the via extrusion for the 2μm diameter TSVs is higher than that of the 5μm diameter TSVs. These results, validated by thermomechanical simulation, demonstrate first that large sample sizes are required in copper TSV investigations due to high variability, which is not improved with scaling

A Ru-catalyzed one-pot synthesis of homopropargylic amines from alkyl azides under photolytic conditions

A new synthetic method for homopropargylic amines from alkyl azides is presented. A salient feature of this reaction is the involvement of N-unsubstituted imines as the key intermediates, which are generated from alkyl azides by Ru catalysis under photolytic conditions. Notably, this method avoids the use of a protective group strategy in the homopropargylic amine synthesis.X111312sciescopu

Overcoming obstacles associated with other learning experiences and school-based assessment: Perspectives of high school students with visual impairment in Hong Kong - Collaborative research project report

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More on the Nambu-Poisson M5-brane Theory: Scaling limit, background independence and an all order solution to the Seiberg-Witten map

We continue our investigation on the Nambu-Poisson description of M5-brane in a large constant C-field background (NP M5-brane theory) constructed in Refs.[1, 2]. In this paper, the low energy limit where the NP M5-brane theory is applicable is clarified. The background independence of the NP M5-brane theory is made manifest using the variables in the BLG model of multiple M2-branes. An all order solution to the Seiberg-Witten map is also constructed.Comment: expanded explanations, minor corrections and typos correcte

A No-Go Theorem for M5-brane Theory

The BLG model for multiple M2-branes motivates an M5-brane theory with a novel gauge symmetry defined by the Nambu-Poisson structure. This Nambu-Poisson gauge symmetry for an M5-brane in large C-field background can be matched, on double dimension reduction, with the Poisson limit of the noncommutative gauge symmetry for a D4-brane in B-field background. Naively, one expects that there should exist a certain deformation of the Nambu-Poisson structure to match with the full noncommutative gauge symmetry including higher order terms. However, We prove the no-go theorem that there is no way to deform the Nambu-Poisson gauge symmetry, even without assuming the existence of a deformation of Nambu-Poisson bracket, to match with the noncommutative gauge symmetry in 4+1 dimensions to all order, regardless of how the double dimension reduction is implemented.Comment: v4: minor modifications

Adequate symptom relief justifies hepatic resection for benign disease

BACKGROUND: The purpose of this study was to evaluate the long-term results of partial liver resection for benign liver lesions. METHODS: All patients operated on for benign liver lesions from 1991 to 2002 were included. Information was retrieved from medical records, the hospital registration system and by a telephonic questionnaire. RESULTS: Twenty-eight patients with a median age of 41 years (17–71) were operated on (M/F ratio 5/23). The diagnosis was haemangioma in 8 patients, FNH in 6, HCA in 13 and angiomyolipoma in 1. Eight patients were known to have relevant co-morbidity. Median operating time was 207 minutes (45–360). The morbidity rate was 25% and no postoperative mortality was observed. Twenty-two patients (79%) had symptoms (mainly abdominal pain) prior to surgery. Twenty-five patients were reached for a questionnaire. The median follow up was 55 months (4–150). In 89% of patients preoperative symptoms had decreased or disappeared after surgery. Four patients developed late complications. CONCLUSION: Long-term follow up after liver surgery for benign liver lesions shows considerable symptom relief and patient satisfaction. In addition to a correct indication these results justify major surgery with associated morbidity and mortality

Isoflavones in treating watchful waiting benign prostate hyperplasia: a double-blinded, randomized controlled trial

OBJECTIVES: This study aims to determine the efficacy and safety of soy isoflavones in controlling the symptoms and signs of lower urinary tract symptoms due to benign prostate hyperplasia (BPH). DESIGN: This was a prospective, randomized, double-blind, placebo-controlled pilot study. SETTING: This trial was conducted at two hospitals in Hong Kong between May 2006 and September 2007. PARTICIPANTS: One hundred and seventy-six (176) participants diagnosed with BPH were recruited from outpatient clinics. Participants with lower urinary tract symptoms were recruited through newspaper and radio interviews, posters placed at government outpatient clinics, and a public seminar offered by the investigators. INTERVENTIONS: Participants were randomly assigned to either intervention (40 mg of isoflavones daily from Soylife 40) or placebo groups in a double-blind fashion. MAIN OUTCOME MEASURES: The primary outcome parameter of peak urine flow rate and the second outcome parameters of postresidual urine volume, lower urinary tract symptoms, testosterone, prostate-specific antigen, quality of life, diet, and safety profile (liver and renal function) were collected. All parameters were assessed at baseline, 6 months, and 12 months in a 12-month study period except testosterone, prostate-specific antigen, and safety profile, which were assessed at baseline and at 12 months. RESULTS: The peak urine flow rate (Qmax), postresidual urine volume, International Prostate Symptoms Scores (IPSS), and 36-Item Short Form Health Survey (SF-36) significantly improved from baseline to the 12th month within both groups. However, when compared between groups, Qmax (p=0.055) and incomplete emptying subscore in IPSS (p=0.05) were marginally/statistically different between the two groups from the 6th to the 12th months, in addition to the general health domain of SF-36 from the baseline to 12th month (p=0.02) and from the 6th month to the 12th month (p=0.055). Isoflavones were generally safe and well tolerated. CONCLUSIONS: This randomized control pilot study showed only slight superiority of isoflavones over placebo over 12 months with otherwise surprising beneficial effects in both groups. Tolerability of isoflavones was excellent; thus it has laid foundations for further studies of isoflavones in BPH with focus on dosage and possible specificity of the effect.published_or_final_versio

Bidirectional signaling of neuregulin-2 mediates formation of GABAergic synapses and maturation of glutamatergic synapses in newborn granule cells of postnatal hippocampus

Expression of neuregulin-2 (NRG2) is intense in a few regions of the adult brain where neurogenesis persists; however, little is understood about its role in developments of newborn neurons. To study the role of NRG2 in synaptogenesis at different developmental stages, newborn granule cells in rat hippocampal slice cultures were labeled with retrovirus encoding tetracycline-inducible microRNA targeting NRG2 and treated with doxycycline (Dox) at the fourth or seventh postinfection day (dpi). The developmental increase of GABAergic postsynaptic currents (GPSCs) was suppressed by the early Dox treatment (4 dpi), but not by late treatment (7 dpi). The late Dox treatment was used to study the effect of NRG2 depletion specific to excitatory synaptogenesis. The Dox effect on EPSCs emerged 4 d after the impairment in dendritic outgrowth became evident (10 dpi). Notably, Dox treatment abolished the developmental increases of AMPA-receptor mediated EPSCs and the AMPA/NMDA ratio, indicating impaired maturation of glutamatergic synapses. In contrast to GPSCs, Dox effects on EPSCs and dendritic growth were independent of ErbB4 and rescued by concurrent overexpression of NRG2 intracellular domain. These results suggest that forward signaling of NRG2 mediates GABAergic synaptogenesis and its reverse signaling contributes to dendritic outgrowth and maturation of glutamatergic synapses.117Ysciescopu

Diabetes status and post-load plasma glucose concentration in relation to site-specific cancer mortality: findings from the original Whitehall study

ObjectiveWhile several studies have reported on the relation of diabetes status with pancreatic cancer risk, the predictive value of this disorder for other malignancies is unclear. Methods: The Whitehall study, a 25year follow-up for mortality experience of 18,006 men with data on post-challenge blood glucose and self-reported diabetes, allowed us to address these issues. Results: There were 2158 cancer deaths at follow-up. Of the 15 cancer outcomes, diabetes status was positively associated with mortality from carcinoma of the pancreas and liver, while the relationship with lung cancer was inverse, after controlling for a range of potential covariates and mediators which included obesity and socioeconomic position. After excluding deaths occurring in the first 10years of follow-up to examine the effect of reverse causality, the magnitude of the relationships for carcinoma of the pancreas and lung was little altered, while for liver cancer it was markedly attenuated. Conclusions: In the present study, diabetes status was related to pancreatic, liver, and lung cancer risk. Cohorts with serially collected data on blood glucose and covariates are required to further examine this area

Revealing heterogeneous nucleation of primary Si and eutectic Si by AlP in hypereutectic Al-Si alloys

The heterogeneous nucleation of primary Si and eutectic Si can be attributed to the presence of AlP. Although P, in the form of AlP particles, is usually observed in the centre of primary Si, there is still a lack of detailed investigations on the distribution of P within primary Si and eutectic Si in hypereutectic Al-Si alloys at the atomic scale. Here, we report an atomic-scale experimental investigation on the distribution of P in hypereutectic Al-Si alloys. P, in the form of AlP particles, was observed in the centre of primary Si. However, no significant amount of P was detected within primary Si, eutectic Si and the Al matrix. Instead, P was observed at the interface between the Al matrix and eutectic Si, strongly indicating that P, in the form of AlP particles (or AlP ‘patch’ dependent on the P concentration), may have nucleated on the surface of the Al matrix and thereby enhanced the heterogeneous nucleation of eutectic Si. The present investigation reveals some novel insights into heterogeneous nucleation of primary Si and eutectic Si by AlP in hypereutectic Al-Si alloys and can be used to further develop heterogeneous nucleation mechanisms based on adsorption