We investigated the effects of a Ti addition on the reliability and the electrical performance of Cu interconnects, comparing three different ways of Ti addition such as A) Ti layer insertion under ...Ta-TaN stacked barrier metal, B) Ti layer insertion between a Ta-TaN barrier and Cu, and C) the Ti doping from the surface of the electrochemical-plated (ECP) Cu film. The structure-A drastically suppresses the stress-induced voiding (SIV) under the via connected to a wide lower line due to adhesion improvement by Ti at the via-bottom, while the electromigration (EM) is not improved. In the structure-B, by contrast, the EM is improved but the SIV resistance is degraded. The Ti doping from the bottom surface of Cu film restricts the grain growth and increases the tensile stress, enhancing the SIV. The structure-C improves not only the SIV but also the EM resistance. The oxygen gettering effect of Ti during the ECP-Cu annealing is a reason for the reliability improvements of the SIV and the EM. The improvement of adhesiveness at the interface between the via and the lower Cu line, and the oxygen gettering from Cu by Ti play an important role in suppressing the SIV and the EM.
High performance Cu dual-damascene (DD) interconnects without process-induced damages are developed in porous SiOCH stacks with the effective dielectric constant (k eff ) of 2.95, in which a carbon ...(C)-rich molecular-pore-stacking (MPS) SiOCH film (k = 2.5) is stacked directly on an oxygen (O)-rich porous SiOCH (k = 2.7) film. The novel etch-stopperless structure is obtained by comprehensive chemistry design of C/O ratios in the SiOCH stack and the etching plasma of an Ar/N 2 /CF 4 /O 2 gas mixture technique. Large hydrocarbons attached to hexagonal silica backbones in the MPS-SiOCH prevent the Si-CHx bonds from oxidation during O 2 -plasma ashing, suppressing the C-de- pleted damage area at the DD sidewall. Combining multiresist mask process with immersion ArF photolithography, strictly controlled Cu DD interconnects with 180-nm pitched lines and 65-nm-diameter vias are obtained successfully, ready for the 300-mm fabrication.
Aim: To evaluate the value of using perfluorocarbon liquid (PFCL) during vitrectomy in eyes with proliferative diabetic retinopathy (PDR). Methods: The surgical records of eyes with PDR (291 eyes of ...228 patients) that underwent vitrectomy in the vitreoretinal service of Osaka Medical College (April 1999 to October 2001) were reviewed. From these, 18 eyes of 15 patients had PFCL used during vitrectomy, and the preoperative and postoperative findings of these eyes were analysed. Results: All of the 18 eyes had advanced PDR with tractional and/or rhegmatogenous retinal detachment. PFCL enabled easier flattening of the retinal folds and effective endophotocoagulation. In two cases, PFCL was used to flatten a bullous retinal detachment that developed when a tight vitreoretinal adhesion was loosened. In two other cases with combined traction/rhegmatogenous retinal detachment, PFCL was used to tamponade the detached retina which then allowed successful membrane dissection. Anatomical success was obtained in 16 of the 18 cases (mean follow up time 13.3 months) with visual acuity of 20/200 or better in nine eyes (50%). Conclusions: PFCL is considered to be a useful adjunct during vitrectomy for the treatment of severe PDR.
Nerve regeneration is important for the treatment of degenerative diseases and neurons injured by accidents. Nerve growth factor (NGF) has been previously conjugated to materials for promotion of ...neurogenesis.
Photoreactive gelatin was prepared by chemical coupling of gelatin with azidobenzoic acid (P-gel), and then NGF was immobilized on substrates in the presence or absence of micropatterned photomasks. UV irradiation induced crosslinking reactions of P-gel with itself, NGF, and the plate for immobilization.
By adjustment of the P-gel concentration, the nanometer-order height of micropatterns was controlled. NGF was quantitatively immobilized with increasing amounts of P-gel. Immobilized NGF induced neurite outgrowth of PC12 cells, a cell line derived from a pheochromocytoma of the rat adrenal medulla, at the same level as soluble NGF. The immobilized NGF showed higher thermal stability than the soluble NGF and was repeatedly used without loss of biological activity. The 3D structure (height of the formed micropattern) regulated the behavior of neurite guidance. As a result, the orientation of neurites was regulated by the stripe pattern width.
The micropattern-immobilized NGF nanolayer biochemically and topologically regulated neurite formation.
Single-nucleotide polymorphism at -670 of Fas gene promoter (A/G) was examined in a total of 354 blood samples from normal healthy women and gynecological cancer patients. They consisted of 95 ...normal, 83 cervical, 108 endometrial, and 68 ovarian cancer cases. Eighty-three patients with cervical cancer had statistically higher frequency of GG genotype and G allele than 95 controls (P= 0.0353 and 0.0278, respectively). There was no significant difference in the genotype or allele prevalence between control subjects and endometrial or ovarian cancer patients. The Fas -670 GG genotype was associated with an increased risk for the development of cervical cancer (OR = 2.56, 95% CI = 1.08-6.10) compared with the AA genotype. The G allele also increased the risk of cervical cancer (OR = 1.60, 95% CI = 1.05-2.43) compared with the A allele. Germ-line polymorphism of Fas gene promoter -670 may be associated with the risk of cervical cancer in a Japanese population.
Hyaluronan (HA) synthesis in the synovial membrane is affected by various chemical mediators. It is hypothesized that transforming growth factor-beta1 (TGF-β1) would be a mediator to modulate HA ...synthesis in cultured synovial membrane fibroblasts of the temporomandibular joint (TMJ). Fibroblasts were extracted from the TMJ synovial membrane of four-week-old Japanese white rabbits. The amount of HA and expression levels of HA synthase (HAS) mRNAs induced by TGF-β1 treatment were analyzed by means of high-performance liquid chromatography and real-time polymerase chain-reaction, respectively. Both medium and large amounts of HA were enhanced by the stimulation of TGF-β1. HAS2 mRNA expression was enhanced 13-fold after six-hour stimulation with TGF-β1 (10 ng/mL), whereas HAS3 mRNA expression was not changed significantly. These results suggest that TGF-β1 enhances the expression of HAS2 mRNA in the TMJ synovial membrane fibroblasts and may contribute to the production of high-molecular-weight HA in the joint fluid.
An automated extraction and determination method for the gas chromatography (GC)-mass spectrometry (MS) analysis of amphetamine-related drugs in human urine is developed using headspace solid-phase ...microextraction (SPME) and in-matrix derivatization. A urine sample (0.5 mL), potassium carbonate (5M, 1.0 mL), sodium chloride (0.5 g), and ethylchloroformate (20 µL) are put in a sample vial. Amphetamine-related drugs are converted to ethylformate derivatives (carbamates) in the vial because amphetamine-related drugs in urine are quickly reacted with ethylchloroformate. An SPME fiber is then exposed at 80°C for 15 min in the headspace of the vial. The extracted derivatives to the fiber are desorbed by exposing the fiber in the injection port of a GC-MS. The calibration curves show linearity in the range of 1.0 to 1000 ng/mL for methamphetamine, fenfluramine, and methylenedioxymethamphetamine; 2.0 to 1000 ng/mL for amphetamine and phentermine; 5.0 to 1000 ng/mL for methylenedioxyamphetamine; 10 to 1000 ng/mL for phenethylamine; and 50 to 1000 ng/mL for 4-bromo-2,5- dimethoxyphenethylamine in urine. No interferences are found, and the time for analysis is 30 min for one sample. Furthermore, this proposed method is applied to some clinical and medico-legal cases by taking methamphetamine. Methamphetamine and its metabolite amphetamine are detected in the urine samples collected from the patients involved in the clinical cases. Methamphetamine, amphetamine, and phenethylamine are detected in the urine sample collected from the victim of a medico-legal case.
Quantification of disease severity was studied in 72 patients with ulcerative colitis, who had undergone total 85 clinical courses. We performed a multiple stepwise regression analysis, according to ...Truelove and Witts' classification, with disease severity as a dependent variable, and with 18 clinical, laboratory, and endoscopic parameters as independent variables. Results showed that disease severity in patients with ulcerative colitis is significantly influenced by five factors, namely, bloody stool, bowel movements, erythrocyte sedimentation rate (ESR), hemoglobin (Hb), and serum albumin. The activity index (AI) developed for ulcerative colitis is expressed as follows: AI = 60 x blood stool + 13 x bowel movements + 0.5 x ESR - 4 x HB - 15 x albumin + 200. Index values below 150, values between 150 and 220, and values above 220 nearly corresponded to mild, moderate, and severe disease, respectively, in Truelove and Witts' classification. We believe that the activity index is useful in evaluation of the effect of medical treatment in patients with ulcerative colitis. Its most important value will be in therapeutic trials.
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