Phase Equilibria Related to NiGa5 in the Binary Ni-Ga System.

The assembly of Ga alloys with Ni or Ni alloy has been widely developed for various low-temperature applications in recent years. In the constituent Ni-Ga binary system, however, the phase equilibrium with the phase "NiGa5" and its stability has scarcely been investigated. The present study used the diffusion couple technique combined with SEM-EPMA and XRD analysis to examine the phase stability and the homogeneity range of the phase. The results show that "NiGa5" is a stable phase in the binary system with little homogeneity range and suggest that the peritectic reaction L+Ni3Ga7→NiGa5 lies between 112.0 and 115.5 °C. This work provides new information for the modification of the Ga-rich low-T region of the Ni-Ga phase diagram.

Impact of crystalline orientation on Cu-Cu solid-state bonding behavior by molecular dynamics simulations.

High-density electronics are hindered by the constraints of Sn-based solder joints, necessitating the exploration of Cu-Cu solid-state bonding. However, current bonding methods are expensive and time-consuming; therefore, understanding the Cu-Cu bonding mechanism is crucial for optimization. This study utilizes molecular dynamics (MD) simulation to elucidate the Cu-Cu solid-state bonding behavior, focusing on interfacial densification and diffusion phenomena. Furthermore, it highlights the influence of crystal orientation on the interfacial bonding behavior. To analyze the impact of crystal orientation, monocrystalline Cu slabs with a simplified periodic surface structure were employed to replicate surface roughness and subsequently bonded at a specific temperature. The results indicate the critical influence of crystalline orientations on the bonding process: identical orientations result in slower densification at the interface, whereas misoriented orientations significantly accelerate it. This effect, attributed to the grain boundary (GB) structures formed owing to misorientation, suggests a central role for GB diffusion in bonding progression. Diffusion coefficients calculated using the mean square displacement (MSD) confirmed these findings and exhibited significantly larger values for misoriented joints. Additionally, the simulations reveal an activation energy for GB diffusion that is lower than conventional values, highlighting the impact of the crystallographic orientation and voids at the bonding interface. Our research elucidates the role of crystalline orientation in diffusion phenomena at bonding interfaces, offering valuable implications for optimizing bonding-based manufacturing processes.

Artifact-Free Microstructures in the Interfacial Reaction between Eutectic In-48Sn and Cu Using Ion Milling.

Eutectic In-48Sn was considered a promising candidate for low-temperature solder due to its low melting point and excellent mechanical properties. Both Cu2(In,Sn) and Cu(In,Sn)2 formation were observed at the In-48Sn/Cu interface after 160 °C soldering. However, traditional mechanical polishing produces many defects at the In-48Sn/Cu interface, which may affect the accuracy of interfacial reaction investigations. In this study, cryogenic broad Ar+ beam ion milling was used to investigate the interfacial reaction between In-48Sn and Cu during soldering. The phase Cu6(Sn,In)5 was confirmed as the only intermetallic compound formed during 150 °C soldering, while Cu(In,Sn)2 formation was proven to be caused by room-temperature aging after soldering. Both the Cu6(Sn,In)5 and Cu(In,Sn)2 phases were confirmed by EPMA quantitative analysis and TEM selected area electron diffraction. The microstructure evolution and growth mechanism of Cu6(Sn,In)5 during soldering were proposed. In addition, the Young's modulus and hardness of Cu6(Sn,In)5 were determined to be 119.04 ± 3.94 GPa and 6.28 ± 0.13 GPa, respectively, suggesting that the doping of In in Cu6(Sn,In)5 has almost no effect on Young's modulus and hardness.

Long-Term Aging Study on the Solid State Interfacial Reactions of In on Cu Substrate.

Indium is considered a candidate low-temperature solder because of its low melting temperature and excellent mechanical properties. However, the solid-state microstructure evolution of In with different substrates has rarely been studied due to the softness of In. To overcome this difficulty, cryogenic broad Ar+ beam ion polishing was used to produce an artifact-free Cu/In interface for observation. In this study, we accomplished phase identification and microstructure investigation at the Cu/In interface after long-term thermal aging. CuIn2 was observed to grow at the Cu/In interface and proved to be a stable phase in the Cu-In binary system. The peritectoid temperature of the Cu11In9 + In → CuIn2 reaction was confirmed to be between 100 and 120 °C. In addition, the growth rate of CuIn2 was discovered to be dominated by the curvature of the reactant Cu11In9/In phase and the temperature difference with the peritectoid temperature. Finally, a comprehensive microstructural evolution mechanism of the Cu/In solid-state interfacial reaction was proposed.

Solid-state bonding behavior between surface-nanostructured Cu and Au: a molecular dynamics simulation.

In recent years, solid-state bonding has attracted attention for various electronic packaging applications as an alternative to conventional solders. Surface-nanostructured materials enable solid-state bonding without complex surface modifications and operate at a low bonding temperature and pressure. Therefore, in this study, molecular dynamics simulations were conducted to investigate the solid-state bonding behavior between surface-nanostructured Cu and Au, with a focus on diffusion phenomena. A periodic ligament-cavity nanostructured Cu (NS-Cu) model was prepared at the bonding interface between Cu and Au slabs. The simulation results indicated that the larger the specific surface area of NS-Cu, the faster the densification at the bonding interface. Atomic displacement analysis showed that rapid densification occurred via the displacement of Cu and Au atoms in the vicinity of NS-Cu. The preferential diffusion of atoms along NS-Cu cavities contributed to this phenomenon. At this stage of densification, the diffusion coefficients were higher than the surface diffusion coefficients estimated based on literature, which indicates that this behavior is specific to surface-nanostructured materials. The highly disordered atomic arrangement at the bonding interface enabled significant atomic diffusion. Therefore, this study confirmed that the use of surface-nanostructured materials would contribute to a promising bonding technology for application in electronics.

Highly Robust Ti Adhesion Layer during Terminal Reaction in Micro-Bumps.

The use of scaled-down micro-bumps in miniaturized consumer electronic products has led to the easy realization of full intermetallic solder bumps owing to the completion of the wetting layer. However, the direct contact of the intermetallic compounds (IMCs) with the adhesion layer may pose serious reliability concerns. In this study, the terminal reaction of the Ti adhesion layer with Cu-Sn IMCs was investigated by aging the micro-bumps at 200 °C. Although all of the micro-bumps transformed into intermetallic structures after aging, they exhibited a strong attachment to the Ti adhesion layer, which differs significantly from the Cr system where spalling of IMCs occurred during the solid-state reaction. Moreover, the difference in the diffusion rates between Cu and Sn might have induced void formation during aging. These voids progressed to the center of the bump through the depleting Cu layer. However, they neither affected the attachment between the IMCs and the adhesion layer nor reduced the strength of the bumps. In conclusion, the IMCs demonstrated better adhesive behavior with the Ti adhesion layer when compared to Cr, which has been used in previous studies.

Hydrothermally constructed AgWO4-rGO nanocomposites as an electrode enhancer for ultrasensitive electrochemical detection of hazardous herbicide crisquat.

The advancements in electrode materials with high efficiency has been prioritized to effectively monitor the presence of harmful pesticides concerning the environment. In such a way, we hydrothermally constructed a hybrid AgWO4-rGO nanocomposites for the rapid electrochemical detection of crisquat (CQT). The structural, compositional, morphological and topographical characterization for AgWO4-rGO nanocomposites is thoroughly performed to understand its electrocatalytic properties. The AgWO4-rGO nanocomposites are used as an electrode enhancer (rGO@AgWO4/GCE) for the electrochemical investigations towards CQT detection. The results indicated that the rGO@AgWO4/GCE possessed an excellent catalytic activity with a wide linear detection range 1-1108 µM coupled with an ultrasensitive limit of detection (LOD) 0.0661 µM for electrochemical CQT detection. The rGO@AgWO4/GCE CQT sensor also expressed remarkable sensitivity of 0.6306 µAµM-1cm-2 in addition to good selectivity and reproducibility. Furthermore, the commercial CQT, river water, tap water and washed vegetable water are used as a representative for real world analysis using rGO@AgWO4/GCE and results are highly appreciable for the real time CQT detection. Our work proposes a novel hybrid rGO@AgWO4 nanocomposites reinforced electrodes for ultra-trace level CQT detection with good reliability and can be advocated for real time detection of pesticides.

Investigation of Low-Pressure Sn-Passivated Cu-to-Cu Direct Bonding in 3D-Integration.

Cu-to-Cu direct bonding plays an important role in three-dimensional integrated circuits (3D IC). However, the bonding process always requires high temperature, high pressure, and a high degree of consistency in height. In this study, Sn is passivated over electroplated copper. Because Sn is a soft material and has a low melting point, a successful bond can be achieved under low temperature and low pressure (1 MPa) without any planarization process. In this experiment, Sn thickness, bonding temperature, and bonding pressure are variables. Three values of thicknesses of Sn, i.e., 1 µm, 800 nm, and 600 nm were used to calculate the minimum value of Sn thickness required to compensate for the height difference. Additionally, the bonding process was conducted at two temperatures, 220 °C and 250 °C, and their optimized parameters with required pressure were found. Moreover, the optimized parameters after the Cu planarization were also investigated, and it was observed that the bonding can succeed under severe conditions as well. Finally, transmission electron microscopy (TEM) was used to observe the adhesion property between different metals and intermetallic compounds (IMCs).

Immunohistochemical studies of transforming growth factor-beta and its receptors in the gastric mucosa of patients with refractory gastric ulcer.

Transforming growth factor (TGF)-beta regulates cell growth and differentiation, and is known to play regulatory roles in the process of tissue repair and remodeling. However, the functional role of TGF-beta in gastric ulcer healing has not been addressed. In this study, we assayed the expression of TGF-beta and its receptors in the gastric mucosa of patients with healed or refractory gastric ulcers. Antibodies against TGF-beta and its receptors (both type I and type II) were employed to examine expression levels. Sixteen gastric ulcer patients, including four with completely healed ulcers and 12 with ulcers refractory to treatment were included in this study. All four patients with healed ulcers showed remarkable expression levels of both TGF-beta and its receptors. On the other hand, two of the 12 patients with refractory ulcers had weak or deficient TGF-beta expression in the gastric mucosa, and seven lacked expression of at least one of the TGF-beta receptors. The remaining three patients had normal (moderate to weak) expression levels of TGF-beta and its two receptors. These results suggest that both TGF-beta and its receptors are essential for gastric ulcer healing.

[Seasonal variation of peptic ulcer hemorrhage].

Retrospectively analysis of 2015 episodes of duodenal ulcer (DU) hemorrhage, and 874 episodes of gastric ulcer (GU) hemorrhage over a 5-year period (April, 1987-March, 1992) evaluated seasonal incidence. For duodenal ulcers, the highest incidence occurred in January, or a total of 231 episodes over 5 years (4.6% of all medical admission), whereas the lowest incidence was in August, with only 101 episodes in the same period (2.1% of medical admission). There was a statistically greater incidence of DU bleeding during the relatively cool winter months, December to March (835 episodes, 4.3%) vs. the warmer summer months, June to September (500 episodes, 2.5%; p < 0.05). For gastric ulcers, the incidence of bleeding was highest in January and February (1.9%) and lowest in September (1.1%). As with DU, GU bleeding was more common in winter (332 episodes, 1.7%) than in summer (243 episodes, 1.2%; p < 0.05). Over one year of this series (DU bleeds: 390, GU bleeds: 167), there was no predilection for a particular day of the week. Of patients evaluated in that year, 87 with DU and 17 with GU had history of bleeding at least one time before. However, there was no seasonal correlation with the previous bleeding episodes. It was concluded that there is seasonal variation in the incidence of peptic ulcer hemorrhage in our country. However, it is not possible to predict when in the year patients are likely to rebleed.

Management of symptomatic polycystic liver disease: laparoscopy adjuvant with alcohol sclerotherapy.

An 81 year old woman with extensive polycystic liver disease received laparoscopic unroofing and fenestration, followed by 95% ethanol sclerotherapy, resulting in almost complete disappearance of the cysts. Such a procedure can avoid complications of both the multi-segmental liver resections and extensive fenestrations, and untoward reactions from a large amount of alcohol. In addition, it can achieve a satisfactory result. It is suggested that this procedure could be a safe and effective alternative to traditional open surgery in selective patients.

Prevalence of antibodies to hepatitis C virus in patients with nonalcoholic fatty liver.

BACKGROUND: Nonalcoholic fatty liver can be caused by obesity, diabetes mellitus, hyperlipidemia or nonalcoholic steatohepatitis. Hepatitis C viral infection can also cause macrovesicular steatosis and such inflammation of the liver as nonalcoholic steatohepatitis. To determine whether the prevalence of anti-HCV is higher in patients with nonalcoholic fatty liver, this clinical study was undertaken; we also tried to detect which factors predict the presence of anti-HCV in these patients. METHODS: The study included 205 nonalcoholic fatty liver patients (122 males and 83 females) with a mean age of 46.5 years, diagnosed by ultrasonic examination, on whom anti-HCV antibody tests were then done. RESULTS: Eleven cases (5.4%) were anti-HCV positive with a higher mean age of 56.4 +/- 11.1 years (p < 0.05). Anti-HCV positive patients had higher serum AST and ALT levels than negative patients (95 +/- 59 U/L, 166 +/- 116 U/L vs. 34 +/- 26 U/L, 51 +/- 43 U/L; p < 0.05), while anti-HCV negative patients had higher mean body weight (124 +/- 15% vs. 114 +/- 11% of IBW) and serum cholesterol levels (202 +/- 41 mg/dl vs. 159 +/- 45 mg/dl). There was no statistical difference between anti-HCV positive and negative groups in clinical parameters including gender, presence of HBsAg, history of DM, operation, blood transfusion, oral contraceptive usage, and cancer with or without chemotherapy. The prevalence of anti-HCV increased with age from 1.8% in the fourth and fifth decades to 25% in the eighth decade. The prevalence of anti-HCV was 1.4% (1 case) in 72 fatty liver with normal biochemical tests and 7.5% (10 cases) in 133 cases with abnormal biochemical tests, a difference which was statistically marginally significant (p = 0.055). Those with ALT levels greater than three-fold the normal limit had a significantly higher anti-HCV prevalence rate (25.9%) than those with normal (1.4%) or mildly (2.8%) elevated ALT levels (p < 0.001). Logistic regression analysis revealed that only age and serum ALT levels were independent predictive factors for the presence of HCV infection. CONCLUSIONS: Results revealed that the prevalence of anti-HCV in patients with nonalcoholic fatty liver was 5.4%, slightly higher than in the general population. Age and serum ALT level were the predictive factors for the presence of HCV infection.

Cytomegalovirus-associated gastric ulcers in a normal host: a case report.

Cytomegalovirus (CMV) is an ubiquitous organism, recognized as an important pathogen in patients from the neonatal period through adulthood. Although CMV infections in the gastrointestinal tract of immunocompromised individuals have been reported in increasing frequency in recent years, there have been only a few reports of CMV infections in the gastrointestinal tract of normal hosts. Here a 43-year-old female is described; she had had a four-month history of epigastric pain, and an upper gastrointestinal endoscopy revealed multiple gastric ulcers. Histologic examination of biopsies from the ulcers showed cytomegalovirus inclusion bodies. She had no detectable immunological abnormalities, blood transfusion or organ transplant history. Conventional antiulcer treatments achieved no response.

Pancreatic vasoactive intestinal polypeptide-secreting tumor: report of a case.

A 58-year-old Taiwanese woman was admitted to Mackay Memorial Hospital for evaluation profuse watery diarrhea. She presented with watery diarrhea, hypokalemia, and hypochlorhydria, and had experienced these problems for 2 years prior to admission. A pancreatic tumor with liver metastasis was noted by the ultrasound, abdominal CT scanning, and angiography studies. Surgical exploration disclosed an ill-defined ovoid tumor in the body and tail of the pancreas measuring 8 x 3 x 3 cm. The immunohistochemistry study of the tumor for VIP-immunoreactivity (VIP: vasoactive intestinal polypeptide) was markedly positive, and also stained slightly positive for other peptides, including pancreatic polypeptide (PP), calcitonin, glucagon, and neuron-specific enolase (NSE). Postoperatively, the patient recovered immediately from her symptoms and there has been no evidence of recurrence during the past 8 months of follow-up.

[Clinical analysis of adenocarcinoma of the stomach in patients with duodenal ulcer].

In 332 patients of adenocarcinoma of the stomach and 7095 patients with duodenal ulcer collected in 5-year period, 21 cases were found to have both disease entities. With regard to clinical manifestations, gross morphology, microscopic differentiation and management of adenocarcinoma of the stomach, the patients with duodenal ulcer showed no significant difference from those without duodenal ulcer. The activities of the duodenal ulcers could be in acute active stage or present as chronic scar only. The ulcer history varied from several years to more than 15 years. We concluded that the frequency of adenocarcinoma of the stomach developed in patients with duodenal ulcer is not so rare, presentation of epigastric discomfort or signs of UGI bleeding in patients with duodenal ulcer history not always indicated recurrence of ulcer disease.

Pulmonary metastasis of hepatocellular carcinoma associated with transarterial chemoembolization.

UNLABELLED: Recent advances in both diagnosis and treatment of hepatocellular carcinoma have improved the prognosis and changed the clinical significance of the subsequently increasing distant metastases. Pulmonary metastasis of hepatocellular carcinoma associated with transcatheter arterial chemoembolization has rarely been reported. METHODS: To evaluate whether transcatheter arterial chemoembolization increases the risk of pulmonary metastasis of hepatocellular carcinoma, 230 patients were studied. Among them, 156 received transcatheter arterial chemoembolization with an interval of 12-16 weeks, the remaining 74 cases refused transcatheter arterial chemoembolization and received only conservative treatment. All patients were followed up with chest x-ray films taken before transcatheter arterial chemoembolization, during admission or in the out-patient department. The mean follow-up interval was 3.37 +/- 1.51 months. RESULTS: Pulmonary metastasis was found in 25.6% (40/156) and 8.1% (6/74) of the patients with and without transcatheter arterial chemoembolization (p = 0.002). The median interval between initial diagnosis and pulmonary metastasis was 3.39 +/- 0.08 and 11.72 +/- 2.91 months among patients with and without transcatheter arterial chemoembolization (p = 0.001). The mean age, sex, existence of cirrhosis, severity of cirrhosis, presence of collateral arterial circulation, amount of lipiodol and agent of anti-cancer drugs were not associated with the development of lung metastasis. However, factors predisposing to lung metastasis included: solitary tumor with tumor size > 10 cm, multiple tumors with main tumor > 5 cm or diffuse hepatocellular carcinoma, intrahepatic portal vein thrombosis, arterioportal or arteriovenous shunt, and the presence of incomplete tumor necrosis after transcatheter arterial chemoembolization (especially combined with necrotic area > 50% main tumor size). CONCLUSIONS: Pulmonary metastasis associated with transcatheter arterial chemoembolization has a strong adverse impact on patient survival.

Correlation of toxic signs, ultrasonographic findings and pathological changes in cholecystitis.

BACKGROUND: Cholecystitis is a frequently encountered clinical problem. What parameters are reliable in helping predict its severity? METHODS: One hundred and forty-nine cholecystectomized cases of cholecystitis were analysed of which 99 (95 calculous) cases were pathologically diagnosed as chronic cholecystitis and 50 acute (43 calculous) cholecystitis. Medical records were reviewed to determine the frequency of toxic signs. Sonographic findings (performed within three days prior to operation), and final pathological changes with respect to the thickness and echotexture of the gallbladder wall were compared. RESULTS: Of 99 chronic cholecystitis patients, 13 cases showed toxic signs. Sonography detected an abnormal wall in 64, but made a correct diagnosis in only 34 cases. A great discrepancy was found in wall thickness as measured by sonography and pathology. A discrepancy > or = 2mm was noted in 19 cases. Of 50 patients with acute cholecystitis (20 cases had complications, defined as severe acute cholecystitis), 31 cases (14 of the 20 severe acute cases) showed toxic signs. Sonographic findings demonstrated an abnormal wall in 46 cases (19 of the severe acute cases) and an accurate diagnosis in 28 cases (13 of the severe acute cases). A difference in the measurement of gallbladder wall thickness > or = 2mm was noted in 26 patients. CONCLUSIONS: Clinical toxic signs and sonographic findings could not offer sufficient information to quickly identify lifethreatening gallbladder diseases.

Delirium following a switch from cimetidine to famotidine.

OBJECTIVE: To describe a patient who developed delirium when switched from cimetidine to famotidine. CASE SUMMARY: An 84-year-old Taiwanese woman was hospitalized for tarry stools. Her past medical history revealed only a decrease in renal function. She tolerated both oral and intravenous cimetidine therapy with a daily dose of 400-900 mg intermittently for 20 years. On hospital days 1-3, cimetidine 300 mg was injected intravenously every eight hours without difficulty. Considering the possible existence of a cimetidine-resistant bleeding ulcer, famotidine 20 mg was given twice daily orally on hospital days 4-7 and then injected intravenously. Six days after being switched from cimetidine to famotidine, the woman's mental status deteriorated. A series of clinical tests revealed no apparent causative factors. Famotidine was then suspected as a probable cause of her delirium. Discontinuation of the drug resulted in rapid resolution of the patient's delirious status. DICUSSION: Famotidine crosses the blood-brain barrier less easily than cimetidine and was taken for a much shorter period in this patient. Thus, we propose that the occurrence of delirium in this patient was associated with famotidine, but not cimetidine, and was idiosyncratic rather than dose related. Furthermore, this case involved an elderly patient with compromised renal function who developed delirium in response to intravenous, but not oral, administration of famotidine. These factors seem to increase the risk for, famotidine-induced delirium. CONCLUSIONS: Clinicians should be aware of the possible occurrence of delirium following a switch from one histamine2-receptor antagonist to another. In rare instances, patients switched to famotidine from cimetidine may experience delirium, particularly elderly patients with poor renal function who receive intravenous famotidine.

[Mucocele of appendix-report of three cases].

Mucocele of appendix comprises 0.07%-0.3% of the resection of appendix. Three such cases were encountered over the past four years at MMH. Tumor mass could be palpated before operation in two of our cases. The third case was found incidentally during sigmoid cancer resection. Mucocele of the appendix should be differentiated from submucosal lesion such as leiomyoma, lipoma, lymphoma in the cecum or appendiceal abscess. Recent advances of ultrasound, CAT scan as well as angiography have made correct preoperative diagnosis possible, yet literature still shows diverse opinion about its etiology (neoplastic vs. obstructive). Although most authors favor simple appendectomy for the management of this disease, some surgeons still think it should be managed aggressively with colectomy. Rupture of mucocele might result in pseudomyxoma peritonei and possibly a fetal outcome. Avoidance of iatrogenic rupture of appendix is essential. Aggressive removal of accessible masses and implants was suggested in the literature.

Inflammatory fibroid polyp of the jejunum causing intussusception: a case report.

Inflammatory fibroid polyp is a rare benign lesion of the gastrointestinal tract. This report concerns a 56-year-old female who presented with intermittent abdominal pain, vomiting and diarrhea; she had had partial intestinal obstruction over a period of two months. Plain abdomen showed dilatation of the small bowels. Abdominal echo revealed intussusception of the small intestine. During exploratory laparotomy a polypoid dumb-bell shaped polyp was noted as the leading point of the jejunojejunal intussusception, segmental resection of the jejunum was performed. Histological features of the polyp met the diagnosis of inflammatory fibroid polyp.