Effect of copper seed aging on electroplating-induced defects in copper interconnects

Voids in copper thin films, observed after electroplating, have been linked to seed aging that occurs when a wafer is exposed, over time, to clean-room ambient. Oxidation of the copper seed surface prevents wetting during subsequent copper electroplating, leading to voids. Several surface treatments were employed to counteract the seed aging effect, including reduction of the copper oxide film by hydrogen, reverse plating of the copper surface, and rinsing the wafer surface with electrolyte. Each treatment was applied to wafers increasingly aged from 2 to 14 days, just prior to electroplating. Results showed a significant decrease in postelectroplating defects with all three treatments. The reduction of copper oxide by hydrogen exhibited the most marked results. An increase in surface wetting is shown by a decrease in contact angle measurements and an increase in film reflectivity for treated versus untreated copper wafers. This study shows that, although the copper surface exhibits strong aging effects over a short period of time, using proper surface treatments can eliminate such effects and voids.     

Category-specific deficits for grammatical classes of words: evidence for possible anatomical correlates

The sialic acid content and the cell-surface hydrophobicity index of 40 group B streptococci (GBS) strains were assessed. GBS isolated from invasive infections (virulent strains) presented an increased level of sialic acid content (1.4%) when compared with GBS isolated from asymptomatic patients (0.53%). Treatment of GBS strain 85634 with neuraminidase resulted in a decrease (about 25%) in the net negative surface charge as assessed by cell electrophoresis. This finding suggests that sialic acid residues are important anionogenic groups exposed on GBS cell surface. N-acetylneuraminic acid was the only sialic acid derivative characterized in the strain 85634 as evaluated by gas-liquid chromatography. GBS from different serotypes presented a hydrophobic index mean value of 0.9. Even though the sialic acid contributed effectively to the negative charge on GBS cell surface, no difference was observed in the hydrophobic index when virulent and avirulent strains were compared.     

Poly[3-hexyl-4-(6-bromohexyl)thiophene]: a key-intermediate for the synthesis of self-plastifying multifunctional polythiophenes

The synthesis and chemical polymerization of a thiophene disubstituted with an alkylic and an ω-bromine functionalized oligomethylenic chain is described. The obtained polymer, namely the poly[3-hexyl-4-(6-bromohexyl)thiophene], is completely soluble in common organic solvents and its structural, thermal and chemical-physical properties are compared with those of a ‘conventional’ bromohexyl 3-substituted polythiophene. The new polymer may be considered as a key-intermediate for the synthesis of multifunctional soluble polythiophenes since its self-plastifying feature may permit the insertion on the polymeric side-chains, by simple post-polymerization functionalization reactions, of sterically demanding or strongly interacting functional groups, without final solubility being compromised.     

Respiratory failure caused by myopathy in severe sepsis]

The peptide hormone relaxin was isolated in good yield from the ovaries of the pregnant rodent Rattus rattus using a simplified purification schedule. It was subjected to comprehensive chemical characterization to confirm both its purity and predicted composition. The peptide was also chemically synthesized by the solid phase procedure. The two chains comprising the hormone were each assembled by the Boc-polystyrene method and, following conventional purification, combined in solution to form the single intramolecular and two intermolecular disulfide bonds. Following purification, the synthetic rat relaxin was fully chemically characterized and shown to be indistinguishable from the native peptide including by secondary structure analysis using circular dichroism spectroscopy. The native and synthetic rat relaxins were shown to be equally biologically active in the in vitro rat uterine relaxation assay and had pEC50 values that were comparable to synthetic human H2 relaxin.     

The abused child

We compared the antigenic characteristics of two thermo-dependent dimorphic fungi isolated from soil in Botucatu, an endemic area of paracoccidioidomycosis (PCM) and Paracoccidioides brasiliensis. The soil isolates grew as cerebriform colonies at 37 degrees C (yeast form) and as cottonous colonies at 25 degrees C (mycelial form). No pathogenicity for ddY mice or hamsters were observed. In immunodiffusion test, there were precipitation bands between the 2 soil isolates and pooled PCM patient sera. There were also common precipitation bands at 21, 50 and 58 kDa between the soil isolates antigens and PCM patient sera by Western-blotting, but no gp43 kDa band. No gene for gp 43 kDa protein was detected in the soil isolates by PCR. The fact that these isolates were obtained from an endemic area of PCM and there were some antigenic similarities between the soil isolates and P. brasiliensis in immunodiffusion test and Western-blotting may have some importance in epidemiological surveys done with paracoccidioidin as well interfering with the immune response of the exposed population.     

Responses of inferior temporal cortex and hippocampal neurons during delayed matching-to-sample in monkeys (Macaca fascicularis).

Single-unit activity was recorded from inferior temporal (IFT) cortex and the hippocampus in 2 macaques trained on auditory–visual and visual–visual delayed matching-to-sample tasks. The main purpose of the study was to compare the response properties of delay neurons between the 2 areas. The authors noted that (1) IFT cortex delay activity was usually selective to a particular stimulus, whereas hippocampal delay activity was usually nonselective; (2) the level of delay activity was generally larger in the hippocampus than in IFT cortex; and (3) unlike IFT cortex delay activity, hippocampal delay activity tended to increase in magnitude as the delay progressed. The authors also examined the functional significance of delay activity and noted a higher probability of encountering a delay neuron when the monkeys were performing 75–200% correct as compared with 50–75% correct. The significance of these findings for visual recognition memory is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Immunotherapy of experimental metastases by vaccination with interleukin gene-transduced adenocarcinoma cells sharing tumor-associated antigens. Comparison between IL-12 and IL-2 gene-transduced tumor cell vaccines

We have compared the therapeutic activity and characterized the antitumor response induced by IL-12 and IL-2 gene-transduced tumor cell vaccines. Mice bearing lung metastases of the BALB/c colon carcinoma C51 were treated with syngenic, histologically related, and antigenically cross-reacting irradiated IL-12 (C26/IL12) or IL-2 (C26/IL2) gene-transduced C26 tumor cells given s.c. Vaccination with C26/IL12 cells cured 40% of mice, while vaccination with C26/IL2 cells reduced the number of metastatic nodules without affecting survival. Despite this difference, similar antitumor CTL activation was shown in mice treated with C26/IL12 or C26/IL2 cells. The lytic pattern of CTL was shown to be directed to tumor-associated Ags (TAA) shared between the colon carcinomas C51, C26, and CC36 as well as with other syngenic tumors. Both treatments induced anti-TAA Abs, but only sera from mice treated with C26/IL12 contained Ab that lysed tumor cells in a C-dependent cytotoxicity assay. Early infiltration of activated T cells was found in the lungs of mice vaccinated with C26/IL12. CD4+ lymphocytes purified from the lymph nodes draining the vaccination site or from the spleen showed a higher production of IFN-gamma in response to anti-CD3 mAb in C26/IL12 vaccinated mice, while a higher production of IL-4 was shown in mice vaccinated with C26/IL2 cells. These results indicate that the better therapeutic efficacy of vaccination with C26/IL12 is associated with the production of C-binding Ab, an early infiltration of the metastatic lungs by activated T lymphocytes and a predominant systemic activation of Th1 more than Th2 cells.     

Architectural aspects for the evolution of mobile communicationstoward UMTS

The transition from second- to third-generation mobile systems and the evolution paths of the relevant radio/network configurations are driven by technical and market considerations. In fact, these are affecting the standardization and research process ongoing at the regional level (ETSI, ACTS Program, US Joint Technical Committee, Japanese ARIB) as well as the global level (ITU). The related discussion is becoming more and more meaningful for operators and manufacturers who are perceiving, on the one hand, the new perspectives associated with service, features, and bandwidth management evolution, and on the other hand, the great impact that such an evolution could have on the existing market scenario and system development plans. In addition, due to the widespread usage of GSM worldwide, this system should also be considered within the evolution scenarios toward third generation. This paper analyzes the situation emerging from the standards context, identifies some key characteristics associated with current proposals, and tries to define a possible third-generation systems architecture based on the most encouraging propositions, e.g., the separation of radio-dependent and independent functions and the integration with B-ISDN. The paper rationale and the identified solutions reflect the research activities within the ACTS project RAINBOW (radio access independent broad band on wireless), addressing architectural solutions for UMTS (universal mobile telecommunications system), the European developing standard for third-generation systems     

A randomized comparison of Burch colposuspension and abdominal paravaginal defect repair for female stress urinary incontinence

OBJECTIVE: Our aim was to compare Burch colposuspension and paravaginal repair for success rates, complications, and urodynamic effects when the procedures are used in the treatment of stress urinary incontinence. STUDY DESIGN: Thirty-six patients were enrolled. A full urodynamic evaluation was repeated 6 months postoperatively. RESULTS: Twelve (67%) and 17 (94%) subjects (Burch colposuspension vs paravaginal repair) voided spontaneously before discharge (p = 0.04). One patient receiving the Burch procedure underwent urethral dilation for urinary retention. Follow-up was for 1 to 3 years. Differences in subjective and objective cure rates favored the Burch colposuspension over the paravaginal repair: 100% versus 72% (p = 0.02) and 100% versus 61% (p = 0.004), respectively. The paravaginal repair did not produce significant modifications in profilometry. Postoperatively, cotton swab tests had negative results in all patients with the Burch operation and in 33% of those with the paravaginal repair (p = 0.01). CONCLUSION: Paravaginal repair is not recommended for the treatment of stress incontinence, although it was accompanied by a more immediate resumption of voiding.