Development of a Piezoelectric Vacuum Sensing Component for a Wide Pressure Range

In this study, we develop a clamped-clamped beam-type piezoelectric vacuum pressure sensing element. The clamped-clamped piezoelectric beam is composed of a PZT layer and a copper substrate. A pair of electrodes is set near each end. An input voltage is applied to a pair of electrodes to vibrate the piezoelectric beam, and the output voltage is measured at the other pair. Because the viscous forces on the piezoelectric beam vary at different air pressures, the vibration of the beam depends on the vacuum pressure. The developed pressure sensor can sense a wide range of pressure, from 6.5 × 10(-6) to 760 Torr. The experimental results showed that the output voltage is inversely proportional to the gas damping ratio, and thus, the vacuum pressure was estimated from the output voltage

Grey Situation Decision-making Algorithm to Optimize Silicon Wafer Slicing

The slicing of Silicon wafer is a complex manufacturing process in producing the raw materials for electronic chips and requires the efforts to effectively monitor the stability in production line and ensure the quality for the products composed of different shapes and materials. Human decision failure and other analytical errors are the most common source of management problems in such manufacturing stage. This paper presents a case regarding the silicon wafer manufacturing to examine the response to quality errors. The study has adopted the approach of grey situation decision-making algorithm for problem detection that suggests a technique to attain the quality control and reduce potential costs in production

Electronic spectra and photophysics of platinum(II) complexes with α-diimine ligands. Mixed complexes with halide ligands

Emission properties have been studied for a series of compounds of the formula (L_2)PtC1_2, where L_2 is N,N,N',N'-tetramethylethylenediamine, 2,2'-bipyridine (bpy), 4,4'-Me_2bpy, 5,5'-Me_2bpy, 4,4'-(t-Bu)_2bpy, 3,3'-(CH_3OCO)_2bpy, and 1,10-phenanthroline, and also for the compound Pt(bpy)I_2. Most of them exhibit orange to red luminescence from a triplet ligand-field (^3LF) state, both as solids and in glassy solution. These emissions are very broad (fwhm 2300-3400 cm^(-1) at 10 K) and structureless and are strongly Stokes-shifted from absorption. The two exceptions are the solid "red" form of Pt(bpy)Cl_2, which exhibits a relatively narrow (fwhm 1050 cm^(-1) at 10 K), vibronically structured (Δν ~ 1500 cm^-1)) red emission, and Pt(3,3'-(CH_3OCO)_2bpy)Cl_2, which exhibits a broad (fwhm 2500 cm^(-1) at 10 K) but structured (Δν ~1300 cm^(-1)) orange emission. Both of these emissions are assigned to triplet metal-to-ligand charge-transfer (^3MLCT) excited states. For the former compound, a linear-chain structure has destabilized a dσ*(d_(z^2)) level, yielding a dσ* → π*(bpy) state as the lowest energy excited state, while for the latter, the strongly electron-withdrawing substituents have stabilized a bpy π* level, yielding a dσ* → π*(bpy) state as the lowest energy excited state. The relative energies of the various types of excited states, including ligand 3_(ππ*) states, are discussed in detail. The crystal structures of Pt(5,5'-Me_2bpy)Cl_2 (monoclinic Cc, Z = 4, a = 13.413(7) Å, b = 9.063(4) Å, c = 12.261(9) Å, 0 = 121.71(6)') and Pt(3,3'-(CH_3OCO)_2bpy)Cl_2 (triclinic P1, Z = 2, a = 7.288(2) Å, b = 9.932(3) Å, c = 11.881(5) Å, α = 98.04(3)°, β = 103.56(3)°, γ = 106.54(3)°) are reported

Functional Effects of let-7g Expression in Colon Cancer Metastasis.

MicroRNA regulation is crucial for gene expression and cell functions. It has been linked to tumorigenesis, development and metastasis in colorectal cancer (CRC). Recently, the let-7 family has been identified as a tumor suppressor in different types of cancers. However, the function of the let-7 family in CRC metastasis has not been fully investigated. Here, we focused on analyzing the role of let-7g in CRC. The Cancer Genome Atlas (TCGA) genomic datasets of CRC and detailed data from a Taiwanese CRC cohort were applied to study the expression pattern of let-7g. In addition, in vitro as well as in vivo studies have been performed to uncover the effects of let-7g on CRC. We found that the expression of let-7g was significantly lower in CRC specimens. Our results further supported the inhibitory effects of let-7g on CRC cell migration, invasion and extracellular calcium influx through store-operated calcium channels. We report a critical role for let-7g in the pathogenesis of CRC and suggest let-7g as a potential therapeutic target for CRC treatment

RETRACTED ARTICLE: STMN-1 is a potential marker of lymph node metastasis in distal esophageal adenocarcinomas and silencing its expression can reverse malignant phenotype of tumor cells

BACKGROUND: Distal esophageal adenocarcinoma is a highly aggressive neoplasm. Despite advances in diagnosis and therapy, the prognosis is still poor. Stathmin (STMN-1) is a ubiquitously expressed microtubule destabilizing phosphoprotein. It promotes the disassembly of microtubules and prevents assembly. STMN-1 can cause uncontrolled cell proliferation when mutated and not functioning properly. Recently, found to be overexpressed in many types of human cancers. However, its clinical significance remains elusive in distal esophageal adenocarcinoma. Here, we reported for the first time that STMN-1 is highly overexpressed in adenocarcinomas of the distal esophagus and strongly associated with lymph node metastasis. METHODS: STMN-1 expression in 63 cases of distal esophageal adenocarcinoma was analyzed by immunoblotting, while expression in esophageal adenocarcinoma cells was determined by immunocytochemistry, immunofluorescence, qRT-PCR and western blotting. Lentivirus-mediated RNAi was employed to knock-down STMN-1 expression in Human esophageal adenocarcinoma cells. The relationship between STMN-1 expression and lymph node metastasis in distal esophageal adenocarcinoma was determined by univariate and multivariate analyses. RESULTS: STMN-1 was detected in 31 (49.21%) of the 63 cases. STMN-1 was highly overexpressed in specimens with lymph node metastasis pN (+), but its expression was almost undetected in pN (−) status. Multivarian regression analysis demonstrated that STMN-1 overexpression is an independent factor for lymph node metastasis in distal esophageal adenocarcinoma. STMN-1 shRNA effectively reduced STMN-1 expression in esophageal adenocarcinoma cells (P < 0.05), which significantly suppressed proliferation (P < 0.05), increased migration (P < 0.05) and invasion ability (P < 0.05) and G1 phase arrest (P < 0.05) which lead to induction of apoptosis in esophageal adenocarcinoma cells in vitro. To verify the in vitro data, we conducted in vivo tumor xenograft studies. Esophageal adenocarcinoma cells stably transfected with STMN-1 shRNA significantly reduced tumor xenografts volume in vivo. CONCLUSIONS: STMN-1 overexpression is associated with lymph node metastasis and increase malignancy in distal esophageal adenocarcinoma. In vivo and in vitro laboratory findings, suggests that STMN-1 may be a suitable target for future therapeutic strategies in distal esophageal adenocarcinoma

Spin-glass ground state in a triangular-lattice compound YbZnGaO4_4

We report on comprehensive results identifying the ground state of a triangular-lattice structured YbZnGaO$_4$ to be spin glass, including no long-range magnetic order, prominent broad excitation continua, and absence of magnetic thermal conductivity. More crucially, from the ultralow-temperature a.c. susceptibility measurements, we unambiguously observe frequency-dependent peaks around 0.1 K, indicating the spin-glass ground state. We suggest this conclusion to hold also for its sister compound YbMgGaO$_4$, which is confirmed by the observation of spin freezing at low temperatures. We consider disorder and frustration to be the main driving force for the spin-glass phase.Comment: Version as accepted to PR