Au-SN Flip-Chip Solder Bump for Microelectronic and Optoelectronic Applications

As an alternative to the time-consuming solder pre-forms and pastes currently used, a co-electroplating method of eutectic Au-Sn alloy was used in this study. Using a co-electroplating process, it was possible to plate the Au-Sn solder directly onto a wafer at or near the eutectic composition from a single solution. Two distinct phases, Au5Sn and AuSn, were deposited at a composition of 30at.%Sn. The Au-Sn flip-chip joints were formed at 300 and 400 degrees without using any flux. In the case where the samples were reflowed at 300 degrees, only an (Au,Ni)3Sn2 IMC layer formed at the interface between the Au-Sn solder and Ni UBM. On the other hand, two IMC layers, (Au,Ni)3Sn2 and (Au,Ni)3Sn, were found at the interfaces of the samples reflowed at 400 degrees. As the reflow time increased, the thickness of the (Au,Ni)3Sn2 and (Au,Ni)3Sn IMC layers formed at the interface increased and the eutectic lamellae in the bulk solder coarsened.Comment: Submitted on behalf of TIMA Editions (http://irevues.inist.fr/tima-editions

Stereoselective rearrangement of guaianolides to tricyclic δ-valerolactones

An unprecedented, highly stereoselective rearrangement of guaianolides, bearing a double bond at the C-6/C-6a position, to tricyclic δ-valerolactones is described

Evaluation of kidney size in children: a pilot study of renal length as a surrogate of organ growth

PurposeSomatic growth is an important indicator of health in children. Adequate organ growth is essential in growth and directly related to body growth. We consider renal length as a surrogate of organ growth in growing children. Measurement of weight, height, and many anthropometric indices, such as body surface area (BSA), body mass index (BMI), and Rohrer and Kaup indices, are used to evaluate growth status. The aim of this study was to evaluate the association between renal length and somatic parameters and analyze the affecting factors for renal size during growth.MethodsThe data for renal length in 66 children (age, 12.9±15.6 months; male/female, 34/32) were obtained. Each kidney was measured with ultrasonography and dimercaptosuccinic acid scan. The data on age, sex, height, and weight were obtained from the medical records. BSA, BMI, and Rohrer and Kaup indices were calculated from measured height and weight. BSA was calculated by 2 methods, and is expressed as BSA I and BSA II.ResultsThere were significant correlations between renal size and age, weight, height, BSA I, BSA II, and Rohrer index. In the regression analysis, the most significant contributing factor to renal growth was height (R2=0.636, P<0.001).ConclusionHeight seems to be the most important factor associated with organ growth in growing children. Further studies to evaluate adequate organ growth should be carried out

TRAIL Enhances Apoptosis of Human Hepatocellular Carcinoma Cells Sensitized by Hepatitis C Virus Infection: Therapeutic Implications

Hepatitis C virus (HCV) infection causes chronic liver diseases leading to hepatocellular carcinoma (HCC) and liver failure. We have previously shown that HCV sensitizes hepatocytes to mitochondrial apoptosis via the TRAIL death receptors DR4 and DR5. Although TRAIL and its receptors are selective targets for cancer therapy, their potential against HCC with chronic HCV infection has not been explored yet. Here we show that HCV induces DR4/DR5-dependent activation of caspase-8 leading to elevation of apoptotic signaling in infected cells and also present TRAIL effect in HCV-induced apoptotic signaling. HCV induced proteolytic cleavage of caspase-9 by stimulating DR4 and DR5, resulting in subsequent cleavage of caspase-3. Further, HCV-induced proteolytic cleavage in caspase-8, caspase-9, and caspase-3 was enhanced in the presence of recombinant TRAIL. HCV-induced cleavage in caspase-9 and increase in caspase-3/7 activity was completely suppressed by silencing of either DR4 or DR5. Perturbing DR4/DR5-caspase-8 signaling complex by silencing DR4 and DR5 or by chemical inhibitor specific to caspase-8 led to decrease of HCV-induced cleavage of poly(ADP-ribose) polymerase (PARP), a substrate for caspase-3 during apoptosis, indicating the functional role of caspase-8 in HCV-induced apoptotic signaling network. Furthermore, TRAIL enhanced PARP cleavage in apoptotic response induced by HCV infection, indicating the effect of TRAIL for the induction of selective apoptosis of HCC cells infected with HCV. Given the importance of apoptosis in HCC development, our data suggest that HCV-induced DR4 and DR5 may be considered as an attractive target for TRAIL therapy against HCC with chronic HCV infection

The impact of pegylated interferon and ribavirin combination treatment on lipid metabolism and insulin resistance in chronic hepatitis C patients

Background/AimsLipid profile and insulin resistance (IR) are associated with hepatitis C virus (HCV) and may predict the chronic hepatitis C (CHC) treatment response. The aim of this study was to determine the association between CHC treatment response and lipid profile and IR change during treatment.MethodsIn total, 203 CHC patients were reviewed retrospectively between January 2005 and December 2011 at Soon Chun Hyang University Hospital. The lipid profile, homeostasis model for assessment (HOMA) of IR (HOMA-IR), and HOMA of β cells (HOMA-β) were evaluated before interferon plus ribavirin therapy (BTx), at the end of treatment (DTx), and 24 weeks after the end of treatment (ATx).ResultsA sustained virologic response (SVR) was achieved by 81% of all patients (49/60), 60% (n=36) of whom possessed genotype 1, with the remainder being non-genotype-1 (40%, n=24). Apart from age, which was significantly higher in the non-SVR group (SVR, 48.0±11.2 years, mean±SD; non-SVR, 56.6±9.9 years; P2.5), HOMA-IR was significantly changed at DTx in the SVR group.ConclusionsLDL-C appears to be associated with HCV treatment in SVR patients. Furthermore, eradication of HCV may improve whole-body IR and insulin hypersecretion, as well as high baseline insulin resistance (HOMA-IR >2.5)

The usefulness of transient elastography, acoustic-radiation-force impulse elastography, and real-time elastography for the evaluation of liver fibrosis

Background/AimsSeveral noninvasive methods have recently been developed for the evaluation of liver fibrosis. The accuracy of transient elastography (TE), acoustic-radiation-force impulse (ARFI) elastography, and real-time elastography (RTE) in predicting liver fibrosis were evaluated.MethodsSeventy-four patients who had undergone a liver biopsy within the previous 6 months were submitted to evaluation with TE, ARFI, and RTE on the same day.ResultsThere were significant correlations between fibrosis stage and liver stiffness measurement (LSM) using the three tested methods: TE, r2=0.272, P=0.0002; ARFI, r2=0.225, P=0.0017; and RTE, r2=0.228, P=0.0015. The areas under the receiver operating characteristic curves (AUROC) for the diagnosis of significant fibrosis (≥F2, Metavir stage) by TE, ARFI, RTE, TE/platelet count (PLT), velocity of shear wave (Vs)/PLT, and elasticity score (Es)/PLT were 0.727, 0.715, 0.507, 0.876, 0.874, and 0.811, respectively. The AUROC for the diagnosis of cirrhosis by TE, ARFI, RTE, TE/PLT, Vs/PLT, and Es/PLT were 0.786, 0.807, 0.767, 0.836, 0.819, and 0.838, respectively. Comparisons of AUROC between all LSMs for predicting significant fibrosis (≥F2) produced the following results: TE vs. RTE, P=0.0069; ARFI vs. RTE, P=0.0277; and TE vs. ARFI, P=0.8836. Applying PLT, the ability of each LSM to predict fibrosis stage significantly increased: TE/PLT vs. TE, P=0.0004; Vs/PLT vs. ARFI, P=0.0022; and Es/PLT vs. RTE, P<0.0001. However, the ability to predict cirrhosis was not enhanced, combining LSM and PLT.ConclusionsTE and ARFI may be better methods for predicting significant liver fibrosis than RTE. This predictive ability increased significantly when accounting for platelet count. However, all of the measures had comparable efficacies for predicting cirrhosis

The secondary prophylactic efficacy of beta-blocker after endoscopic gastric variceal obturation for first acute episode of gastric variceal bleeding

Background/AimsThe most appropriate treatment for acute gastric variceal bleeding (GVB) is currently endoscopic gastric variceal obturation (GVO) using Histoacryl®. However, the secondary prophylactic efficacy of beta-blocker (BB) after GVO for the first acute episode of GVB has not yet been established. The secondary prophylactic efficacy of BB after GVO for the first acute episode of GVB was evaluated in this study.MethodsNinety-three patients at Soonchunhyang University Hospital with acute GVB who received GVO using Histoacryl® were enrolled between June 2001 and March 2010. Among these, 42 patients underwent GVO alone (GVO group) and 51 patients underwent GVO with adjuvant BB therapy (GVO+BB group). This study was intended for patients in whom a desired heart rate was reached. The rates of rebleeding-free survival and overall survival were calculated for the two study groups using Kaplan-Meyer analysis and Cox's proportional-hazards model.ResultsThe follow-up period after the initial eradication of gastric varices was 18.14±25.22 months (mean±SD). During the follow-up period, rebleeding occurred in 10 (23.8%) and 21 (41.2%) GVO and GVO+BB patients, respectively, and 39 patients died [23 (54.8%) in the GVO group and 16 (31.4%) in the GVO+BB group]. The mean rebleeding-free survival time did not differ significantly between the GVO and GVO+BB groups (65.40 and 37.40 months, respectively; P=0.774), whereas the mean overall survival time did differ (52.54 and 72.65 months, respectively; P=0.036).Conclusions Adjuvant BB therapy after GVO using Histoacryl® for the first acute episode of GVB could decrease the mortality rate relative to GVO alone. However, adjuvant BB therapy afforded no benefit for the secondary prevention of rebleeding in GV

Cyclooxygenase-2 and vascular endothelial growth factor in chronic hepatitis, cirrhosis and hepatocellular carcinoma

Background/AimsCyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) are up-regulated in hepatocellular carcinoma (HCC). To investigate the levels of COX-2 and VEGF expression in chronic hepatitis (CH), cirrhosis, and HCC.MethodsThe immunohistochemical expressions of COX-2 and VEGF were evaluated in tissues from patients with CH (n=95), cirrhosis (n=38), low-grade HCC (LG-HCC; n=6), and high-grade HCC (HG-HCC; n=29).ResultsThe COX-2 expression scores in CH, cirrhosis, LG-HCC, and HG-HCC were 3.3±1.9 (mean±SD), 4.2±1.7, 5.5±1.0, and 3.4±2.4, respectively (CH vs. cirrhosis, P=0.016; CH vs. LG-HCC, P=0.008; LG-HCC vs. HG-HCC, P=0.004), and the corresponding VEGF expression scores were 0.9±0.8, 1.5±0.7, 1.8±0.9, and 1.6±1.1 (CH vs. cirrhosis, P<0.001; CH vs. LG-HCC, P=0.011; LG-HCC vs. HG-HCC, P=0.075). Both factors were correlated with the fibrosis stage in CH and cirrhosis (COX-2: r=0.427, P<0.001; VEGF: r=0.491, P<0.001). There was a significant correlation between COX-2 and VEGF in all of the tissue samples (r=0.648, P<0.001), and between high COX-2 and VEGF expression scores and survival (COX-2: P=0.001; VEGF: P<0.001).ConclusionsThe expressions of both COX-2 and VEGF are significantly higher in cirrhosis and LG-HCC than in CH. High COX-2 and high VEGF expressions are associated with a high survival rate

A reduced dose of ribavirin does not influence the virologic response during pegylated interferon alpha-2b and ribavirin combination therapy in patients with genotype 1 chronic hepatitis C

Background/AimsWhen combined with pegylated interferon alpha-2b (Peg-IFN α-2b) for the treatment of genotype 1 chronic hepatitis C (CHC) in Korea, the current guideline for the initial ribavirin (RBV) dose is based on body weight. However, since the mean body weight is lower for Korean patients than for patients in Western countries, current guidelines might result in Korean patients being overdosed with RBV.MethodsWe retrospectively reviewed the medical records of patients with genotype 1 CHC who were treated with Peg-IFN α-2b and RBV combination therapy. We divided the patients into groups A (≥15 mg/kg/day, n=23) and B (<15 mg/kg/day, n=26), given that the standard dose is 15 mg/kg/day. The clinical course in terms of the virologic response, adverse events, and dose modification rate was compared between the two groups after therapy completion.ResultsThe early response rates (92.0% vs. 83.3%, P=0.634) and sustained virologic response rates (82.6% vs. 73.1%, P=0.506) did not differ significantly between the two groups. During the treatment period, the RBV dose reduction rate was significantly higher in group A than in group B (60.9% vs. 23.1%, P=0.01).ConclusionsRBV dose reduction is performed frequently when patients are treated according to the current Korean guidelines. Given that lowering the RBV dose did not appear to decrease the virologic response during therapy, reducing RBV doses below the current Korean guideline may be effective for treatment, especially in low-weight patients