Local tentative bonding method to maintain alignment accuracy in bonding process using resin as an adhesive material

The authors proposed a novel method to maintain the alignment accuracy in the wafer-bonding process, which uses a resin as an adhesive material. Recently, the resin has received attention as an adhesive material for wafer bonding in microelectromechanical system device fabrication because of its multiple advantageous material properties. However, because of its inherent material viscosity, the alignment accuracy cannot be easily maintained, particularly when two wafers are bonded with a thick resin after alignment. To solve this problem, they proposed a local tentative bonding method. After aligning the two wafers, they irradiated the adhesive resin layer between the wafers using a near-infrared (NIR) spotlight (wavelength = 1020 nm), which is transparent to Si wafers. Using several NIR irradiation spots aimed at the resin layer after aligning the wafers, the resin layer was bonded locally and tentatively, which was sufficiently secure to avoid wafer shifting in the subsequent process. The local tentative bonded areas acted as anchors, which held the wafers during the bonding process. They performed experiments to demonstrate the effectiveness of their method using resins, such as polyimide, benzocyclobutene and SU-8. Consequently, they achieved an alignment accuracy <5 µm, which is a significant improvement compared with the typical bonding results

Evaluation of the Growth-Inhibitory Spectrum of Three Types of Cyanoacrylate Nanoparticles on Gram-Positive and Gram-Negative Bacteria

The development of novel effective antibacterial agents is crucial due to increasing antibiotic resistance in various bacteria. Poly (alkyl cyanoacrylate) nanoparticles (PACA-NPs) are promising novel antibacterial agents as they have shown antibacterial activity against several Gram-positive and Gram-negative bacteria. However, the antibacterial mechanism remains unclear. Here, we compared the antibacterial efficacy of ethyl cyanoacrylate nanoparticles (ECA-NPs), isobutyl cyanoacrylate NPs (iBCA-NPs), and ethoxyethyl cyanoacrylate NPs (EECA-NPs) using five Gram-positive and five Gram-negative bacteria. Among these resin nanoparticles, ECA-NPs showed the highest growth inhibitory effect against all the examined bacterial species, and this effect was higher against Gram-positive bacteria than Gram-negative. While iBCA-NP could inhibit the cell growth only in two Gram-positive bacteria, i.e., Bacillus subtilis and Staphylococcus aureus, it had negligible inhibitory effect against all five Gram-negative bacteria examined. Irrespective of the differences in growth inhibition induced by these three NPs, N-acetyl-L-cysteine (NAC), a well-known reactive oxygen species (ROS) scavenger, efficiently restored growth in all the bacterial strains to that similar to untreated cells. This strongly suggests that the exposure to NPs generates ROS, which mainly induces cell growth inhibition irrespective of the difference in bacterial species and cyanoacrylate NPs used

Sex-inducing effects toward planarians widely present among parasitic flatworms

Summary Various parasitic flatworms infect vertebrates for sexual reproduction, often causing devastating diseases in their hosts. Consequently, flatworms are of great socioeconomic and biomedical importance. Although the cessation of parasitic flatworm sexual reproduction is a major target of anti-parasitic drug design, little is known regarding bioactive compounds controlling flatworm sexual maturation. Using the planarian Dugesia ryukyuensis, we observed that sex-inducing substances found in planarians are also widespread in parasitic flatworms, such as monogeneans and flukes (but not in tapeworms). Reverse-phase HPLC analysis revealed the sex-inducing substance(s) eluting around the tryptophan retention time in the fluke Calicophoron calicophorum, consistent with previous studies on the planarian Bipalium nobile, suggesting that the substance(s) is likely conserved among flatworms. Moreover, six of the 18 ovary-inducing substances identified via transcriptome and metabolome analyses are involved in purine metabolism. Our findings provide a basis for understanding and modifying the life cycles of various parasitic flatworms.journal articl

Development and validation of questionnaires for eating‐related distress among advanced cancer patients and families

Background: Eating‐related distress (ERD) is one type of psychosocial distress among advanced cancer patients and family caregivers. Its alleviation is a key issue in palliative care; however, there is no validated tool for measuring ERD. Methods: The purpose of this study was to validate tools for evaluating ERD among patients and family caregivers. The study consisted of a development and validation/retest phase. In the development phase, we made preliminary questionnaires for patients and family caregivers. After face validity and content validity, we performed an exploratory factor analysis and discussed the final adoption of items. In the validation/retest phase, we examined factor validity with an exploratory factor analysis. We calculated Pearson's correlation coefficients between the questionnaire for patients, the Functional Assessment of Anorexia/Cachexia Therapy Anorexia Cachexia Subscale (FAACT ACS) and the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire‐Cachexia 24 (EORTC QLQ‐CAX24) and Pearson's correlation coefficients between the questionnaire for family caregivers and the Caregiver Quality of Life Index‐Cancer (CQOLC) for concurrent validity. We calculated Cronbach's alpha coefficients (Cronbach's alpha) and intraclass correlation coefficients (ICCs) for internal consistency and test–retest reliability. We performed the Mann–Whitney U test between the questionnaires and cancer cachexia based on criteria from the international consensus for known‐group validity. Results: In the development phase, 162 pairs of patients and family caregivers were asked to participate, and 144 patients and 106 family caregivers responded. In the validation/retest phase, 333 pairs of patients and family caregivers were asked to participate, and 234 patients and 152 family caregivers responded. Overall, 183 patients and 112 family caregivers did the retest. Seven conceptual groups were extracted for the ERD among patients and family caregivers, respectively. Patient factors 1–7 correlated with FAACT ACS (r = −0.63, −0.43, −0.55, −0.40, −0.38, −0.54, −0.38, respectively) and EORTC QLQ‐CAX24 (r = 0.58, 0.40, 0.60, 0.49, 0.38, 0.59, 0.42, respectively). Family factors 1–7 correlated with CQOLC (r = −0.34, −0.30, −0.37, −0.37, −0.46, −0.42, −0.40, respectively). The values of Cronbach's alpha and ICC of each factor and all factors of patients ranged from 0.84 to 0.96 and 0.67 to 0.83, respectively. Those of each factor and all factors of family caregivers ranged from 0.84 to 0.96 and 0.63 to 0.84, respectively. The cachexia group of patients had significantly higher scores than the non‐cachexia group for each factor and all factors. Conclusions: Newly developed tools for measuring ERD experienced by advanced cancer patients and family caregivers have been validated

Microsatellite Polymorphism in Natural Populations of the Wild Plant Arabidopsis thaliana

Variation in repeat number at 20 microsatellite loci of Arabidopsis thaliana was studied in a worldwide sample of 42 ecotypes to investigate the pattern and level of polymorphism in repetitive sequences in natural plant populations. There is a substantial amount of variation at microsatellite loci despite the selfing nature of this plant species. The average gene diversity was 0.794 and the average number of alleles per locus was 10.6. The distribution of alleles was centered around the mean of repeat number at most loci, but could not be regarded as normal. There was a significantly positive correlation between the number of repeats and the amount of variation. For most loci, the observed number of alleles was between the expected values of the infinite allele and stepwise mutation models. The two models were rejected by the sign test. Linkage disequilibrium was detected in 12.1% of the pairwise comparisons between loci. In phylogenetic tree, there was no association between ecotype and geographic origin. This result is consistent with the recent expansion of A. thaliana throughout the world

Intragenic Recombination in the Adh Locws of the Wild Plant Arabidopsis thaliana

Nucleotide variation in the Adh region of the wild plant Arabidopsis thaliana was analyzed in 17 ecotypes sampled worldwide to investigate DNA polymorphism in natural plant populations. The investigated 2.4kb Adh region was divided into four blocks by intragenic recombinations between two parental sequence types that diverged 6.3 million years (Myr) ago, if the nucleotide mutation rate μ = 10−9 is assumed. Within each block, dimorphism of segregating variations was observed with intermediate frequencies, which caused a substantial amount of nucleotide variation in A. thaliana at the species level. The first recombination introduced the divergent variation that resulted in dimorphism in this plant species ~3.3 Myr ago, and three subsequent intragenic recombinations have occurred sporadically in ~1.1-Myr intervals. It was shown that there was only a limited number (six) of sequence types in this species and that no clear association was observed between sequence type and geographic origin. Taken together, these results suggest that A. thaliana has spread over the world only recently. It can be concluded that recombination played an important role in the evolutionary history of A. thaliana, especially through the generation of DNA polymorphism in the natural populations of this plant species

Intra- and interspecific DNA variation and codon bias of the alcohol dehydrogenase (Adh) locus in Arabis and Arabidopsis species

Sequence variation at the alcohol dehydrogenase (Adh) locus was analyzed for six species each of the genera Arabis and Arabidopsis. Phylogenetic analysis showed that investigated species were grouped into three clusters, and the generic classification did not correspond to the clusterings. The results indicated that the genera could not be distinguished on the basis of the Adh variation. A significant difference in the ratio of silent to replacement sites was detected by MK test in two comparisons, with Arabidopsis thaliana polymorphism due to excess silent divergence. Silent changes were predominant in the evolution of the Adh locus in Arabis and Arabidopsis. To infer evolutionary significance of silent substitutions, codon bias was studied. The degree of codon bias of the Adh region was relatively constant over Arabis and Arabidopsis species. "Preferred" codons of A. thaliana were determined. No evidence of natural selection on codon change was detected in the Adh regions of A. thaliana and Arabis gemmifera

Nucleotide polymorphism in the acidic chitinase locus (ChiA) region of the wild plant Arabidopsis thaliana

To investigate DNA variation in natural plant populations, a 1.8-kb region of the acidic chitinase locus (ChiA)was analyzed for 17 ecotypes of Arabidopsis thaliana sampled worldwide and 3 Arabis species in Japan. As in the Adh region, dimorphism was detected throughout the investigated ChiA region, suggesting the possibility that dimorphic DNA variation exists in the entire nuclear genome of A. thaliana. The ChiA region was divided into two blocks by an intragenic recombination between two parental sequence types, which diverged 7.4 MYA under the assumption that nucleotide mutation rate per site per year is mu = 10(-9). Nucleotide diversity in the entire ChiA region was 0.0104. Tajima\u27s test was significantly negative for both nucleotide and indel variations, which was manifested as an excess of unique polymorphisms. However, the level and pattern of polymorphism in the ChiA region were inconsistent with simple theoretical explanations. The HKA test detected no difference in the levels of intra- and interspecific variations between the ChiA and Adh regions. In the ChiA coding region, no difference in the patterns of synonymous and replacement variation was found in intra- and interspecific comparisons by the MK test. Although it was difficult to determine the exact genetic mechanism acting on the ChA locus, these results suggested that the ChA locus region was under the same genetic mechanism before and after the establishment of A. thaliana as a species