Mechanically controllable nonlinear dielectrics.

Strain-sensitive Ba x Sr1-x TiO3 perovskite systems are widely used because of their superior nonlinear dielectric behaviors. In this research, new heterostructures including paraelectric Ba0.5Sr0.5TiO3 (BSTO) and ferroelectric BaTiO3 (BTO) materials were epitaxially fabricated on flexible muscovite substrate. Through simple bending, the application of mechanical force can regulate the dielectric constant of BSTO from -77 to 36% and the channel current of BTO-based ferroelectric field effect transistor by two orders. The detailed mechanism was studied through the exploration of phase transition and determination of band structure. In addition, the phase-field simulations were implemented to provide theoretical support. This research opens a new avenue for mechanically controllable components based on high-quality oxide heteroepitaxy.

Comparison of epidermal growth factor receptor mutations between primary and corresponding metastatic tumors in tyrosine kinase inhibitor-naive non-small-cell lung cancer.

BACKGROUND: Mutations of the epidermal growth factor receptor (EGFR) gene in non-small-cell lung cancer (NSCLC) patients predict the patients who will respond to EGFR tyrosine kinase inhibitor (TKI) treatment. A recent study has suggested that 33% of NSCLC showed primary tumor/metastasis discordance of EGFR expression by immunohistochemistry analysis. We intended to find out whether the EGFR mutations of primary lung cancers are concordant to that of corresponding metastatic tumors. MATERIALS AND METHODS: We analyzed EGFR exons 18-21 from paired primary and metastatic tumors in 67 lung cancer patients who had not received TKI before tissues were sampled. RESULTS: Using the direct sequencing method, 9 of 18 (50%) patients with EGFR mutation-positive primary lung tumors had lost the mutations in metastases. For 26 patients who were EGFR mutation positive in the metastatic tumors, 17 (65%) were negative in the primary tumors. We analyzed these paired tissues with discrepant EGFR mutations by the Scorpion Amplified Refractory Mutation System assay. Finally, the discordant rate reached 27% (18 of 67 cases). CONCLUSION: EGFR mutations in primary lung tumors do not always reflect the same situation in metastases. Analysis of EGFR mutations in the primary lung tumor would be inadequate for planning the use of TKI for advanced NSCLC.

Formation of interstellar 2,4-pentadiynylidyne, HCCCCC(X 2Pi), via the neutral-neutral reaction of ground state carbon atom, C(3P), with diacetylene, HCCCCH(X 1Sigma(g)+).

The interstellar reaction of ground-state carbon atom with the simplest polyyne, diacetylene (HCCCCH), is investigated theoretically to explore probable routes to form hydrogen-deficient carbon clusters at ultralow temperature in cold molecular clouds. The isomerization and dissociation channels for each of the three collision complexes are characterized by utilizing the unrestricted B3LYP/6-311G(d,p) level of theory and the CCSD(T)/cc-pVTZ calculations. With facilitation of RRKM and variational RRKM rate constants at collision energies of 0-10 kcalmol, the most probable paths, thus reaction mechanism, are determined. Subsequently, the corresponding rate equations are solved that the evolutions of concentrations of collision complexes, intermediates, and products versus time are obtained. As a result, the final products and yields are identified. This study predicts that three collision complexes, c1, c2, and c3, would produce a single final product, 2,4-pentadiynylidyne, HCCCCC(X (2)Pi), C(5)H (p1)+H, via the most stable intermediate, carbon chain HC(5)H (i4). Our investigation indicates the title reaction is efficient to form astronomically observed 2,4-pentadiynylidyne in cold molecular clouds, where a typical translational temperature is 10 K, via a single bimolecular gas phase reaction.

Effects of Gender and Age on Immune Responses of Human Peripheral Blood Mononuclear Cells to Probiotics: A Large Scale Pilot Study.

BACKGROUND: Despite the widely accepted concept that probiotics confer miscellaneous benefits to hosts, the controversies surrounding these health-promoting claims cannot be ignored. These controversies hinder development and innovation in this field. RESULTS: To clarify the effects of age and gender on probiotic-induced immune responses, we recruited 1613 Taiwanese individuals and calculated the ratio of IFN-γ to IL-10 production after each individual's PBMCs were stimulated by six probiotic strains (L. paracasei BRAP01, L. acidophilus AD300, B. longum BA100, E. faecium BR0085, L. rhamnosus AD500 and L. reuteri BR101). Our results indicated that gender and age have only minor effects on the immune modulation of probiotics. Additionally, we showed that L. paracasei BRAP01 and L. acidophilus AD300 are the two dominant strains inducing IFN-γ/IL-10 production in Taiwanese individuals and that L. reuteri BR101 was the most effective stimulator of IL-10/IFN-γ. Additionally, a significant inverse relationship between the ability of L. paracasei BRAP01 and L. rhamnosus AD500 to stimulate IFN-γ/IL-10 or IL-10/IFN-γ production was also observed. CONCLUSIONS: Our results indicated that age and gender have only minor effects on the immune modulation abilities of probiotics.

False-positive whole-body iodine-131 scan due to intrahepatic duct dilatation.

Focal retention of radioactivity in the liver on whole-body 131I scan was interpreted as a metastatic lesion in a patient with well-differentiated thyroid cancer. Intrahepatic duct dilatation, usually resulting from biliary tract obstruction by bile stone, is a common disorder and may cause bile stasis. A patient with papillary thyroid cancer and a previous history of biliary tract stones had focal retention of radioactivity in the liver on whole-body 131I scan. Abdominal CT, endoscopic retrograde cholagiopancreatography, radionuclide cholangiography and sequential 131I scans demonstrated that this focal retention of radioactivity was caused by intrahepatic duct dilatation. Focal retention of radioactivity is visualized on delayed images but not on early images. The radioactivity initially increases and then decreases on following days.

Receptors for peptide YY and neuropeptide Y on guinea pig pancreatic acini.

We examined the effects of peptide YY (PYY), neuropeptide Y (NPY), and their analogues on dispersed pancreatic acini. Binding of [125I]PYY to acini was saturable, reversible, and specific, and PYY binding was best fit with a two-site model. The relative potencies for inhibiting [125I]PYY binding were PYY > or = NPY > NPY(13-36). There was no inhibition of binding with [Leu31,Pro34]NPY, PYX-2, or pancreatic polypeptide. Both PYY and NPY (0.1 microM) inhibited amylase release stimulated by vasoactive intestinal polypeptide (VIP) (0.3 nM) and forskolin (1 microM) by about 30%, but not that stimulated by cholecystokinin-8 or bombesin. The relative potencies for inhibiting VIP-stimulated amylase release were PYY > or = NPY > NPY(13-36), the same as those for inhibiting VIP-stimulated cAMP increase in acini. No inhibition was detected with [Leu31,Pro34]NPY. This work demonstrates Y2 receptors on guinea pig pancreatic acini mediating inhibitory actions of PYY and NPY on pancreatic enzyme secretion.

Using surfactants to enhance the analyte signals in activated carbon, surface-assisted laser desorption/ionization (SALDI) mass spectrometry.

The effect of surface activity in surface-assisted laser desorption/ionization (SALDI) mass spectrometry was examined. Several surfactants, including p-tolunensulfonic acid (PTSA), sodium dodecyl sulfate and alkyltrimethylammonium bromide, were used as analytes or additives in the SALDI matrix to demonstrate the surface activity effect. The experimental results demonstrate that analytes that have good surface activity have good sensitivity. Adding suitable amounts of surfactants to the SALDI matrix can dramatically enhance the sensitivity of analytes lacking surface activity. We propose that the enhancement of analyte signals is due to the ionic interaction between ionic surfactants and analytes because non-ionic surfactant additives in the SALDI matrix do not affect the analyte signals. The detection limit of methylephedrine can be as low as 100 pg in the SALDI analysis of 0.5 M PTSA additive in the SALDI matrix. Although other surfactants can also be used as matrix additives to enhance the analyte signal, they do not improve the ion abundance as much as PTSA does.

Quantitative cerebral perfusion SPECT in systemic lupus erythematosus with severe central nervous involvement--before and after methylprednisolone pulse therapy.

Severe cerebral involvement may occur in patients with systemic lupus erythematosus. Methylprednisolone pulse therapy is a management choice for those with severe cerebral involvement. However, its effectiveness is uncertain. This article describes Tc-99m HMPAO cerebral perfusion single-photon emission computerized tomography to document the restoration of cerebral perfusion after methylprednisolone pulse therapy in a case of systemic lupus erythromatosus with severe cerebral manifestations.

Diuretic renography findings in enterovesical fistula.

A 73-year-old male presented with a 2 week history of gross haematuria and faecal material in the urine. Bone scan for cancer work-up showed 99T(cm)-MDP radioactivity accumulation in the transverse and descending colon. A 99T(cm)-DTPA diuretic renogram was arranged to study renal function and to determine the location of the enterovesical fistula. Diuretic renography demonstrated extraurinary tract radioactivity in the sigmoid colon in the early images, extending to the descending and transverse colon in the subsequent dynamic images. A sigmoid colon adenocarcinoma with bladder wall invasion and fistula formation was confirmed at surgical operation. The impressive dynamic diuretic renography study in this patient was helpful in determining the location of the fistula and in planning surgical management.

Breast uptake of iodine-131 mimicking lung metastases in a thyroid cancer patient with a pituitary tumour.

We report a case of a 44-year-old female thyroid cancer patient with a pituitary tumour. 131I whole body scanning showed a change of chest uptake from a unilateral crescent uptake to a bilateral full breast uptake pattern. Hyperprolactinaemia and a pituitary tumour were diagnosed as a result of observing the 131I breast uptake.

Cerebral perfusion SPECT in transient ischemic attack.

PURPOSE: The purpose of our study is to evaluate the efficacy of cerebral perfusion single photon emission computerized tomography (SPECT) in patients with transient ischemic attack (TIA). METHODS: Thirty-seven patients with TIA were collected for study. All patients had transient focal neurological symptoms or signs with complete recovery within 24 h after onset. The patients underwent cerebral perfusion SPECT between 6 h and 11 days after onset, with 10 cases performed within 24 h (group A), nine cases performed between 1 and 3 days (group B), 11 cases performed between 3 and 5 days (group C), and seven cases performed after more than 5 days (group D). A semi-quantitative method was used for analyzing the SPECT data, and the difference ratios between lesion side and contralateral normal side were calculated on each pair of regions of interest. RESULTS: In total, 78.4% (29/37) of patients had reduced perfusion in the cerebral cortical regions or deep nuclei, and the regions with reduced perfusion corresponded with clinical presentations of the patients. The abnormal rate with reduced perfusion was 90.0% in group A, 77.8% in group B, 72.7% in group C and 71.4% in group D. Cross cerebellar diaschisis (CCD) was present in seven patients, and all of the primary cerebral perfusion defects of these patients were located at the territory of left or right middle cerebral artery. CONCLUSION: Cerebral perfusion SPECT is a potential tool to detect cerebral perfusion defects and CCD in patients with TIA. Although the perfusion defect may persist more than 5 days after onset, we suggest cerebral perfusion SPECT should be performed as soon as possible.

The 99mTc-DMSA renal scan and 99mTc-DTPA diuretic renogram in children and adolescents with incidental diagnosis of horseshoe kidney.

A prospective study was conducted to determine the possibility of obstructive hydronephrosis in horseshoe kidney found incidentally in school children and adolescents by using a radionuclide diuretic renogram. In a 2-year period, 22 school children and adolescents with horseshoe kidney were found in a mass renal sonography survey. They each underwent a 99mTc dimercaptosuccinic acid renal cortical scan to confirm the horseshoe kidney. Each diuretic renogram was performed with the patient in the supine position to rule out obstructive hydronephrosis. The patients were advised to empty their bladders before the intravenous injection of furosemide (1 mg x kg(-1)). The half-time for the clearance of radioactivity from the renal pelvis were calculated. Of the 22 patients, asymmetrical renal cortical function between the two kidneys was found in 14 (63.6%). Eleven kidneys (11/44, 25%) showed stasis of radioactive urine in the renal pelvic region prior to injection of furosemide. There was no incidence of bilateral hydronephrosis in these 22 patients. Only one kidney (1/44, 2.3%) showed obstructive hydronephrosis and five showed clearance of radioactive urine stasis from the renal pelvis immediately after standing up for voiding. There is a low percentage of obstructive hydronephrosis in these cases of horseshoe kidney found incidentally in children and adolescents. A follow-up cohort study on these patients would be valuable for monitoring the development of complications.

Pyometra as a lower abdominal doughnut sign on a Ga-67 scan.

A 77-year-old woman was referred for Ga-67 scan to evaluate intermittent fever and chills that had lasted more than 20 days. The Ga-67 whole-body scan revealed a doughnut-shaped Ga-67 accumulation in the lower abdominal region. Combined Ga-67 and Tc-99m MDP bone scan confirmed that this activity was in the uterus, because the shape of the urinary bladder on bone scan was different from that of the Ga-67-avid lesion. Pyometra was proved during operation, and pus culture was performed.

Sclerosing cholangitis and oxalate urolithiasis in ulcerative colitis.

We report a 56-year-old man with sclerosing cholangitis and oxalate urolithiasis. These complications occurred five years after proctocolectomy and ileostomy were performed for ulcerative colitis. Two years before, at the time of proctocolectomy, there was no clinical or biochemical evidence of liver abnormality. The occurrence and progression of sclerosing cholangitis five years after proctocolectomy is unusual. Also unusual is the occurrence of oxalate urolithiasis; more common in ulcerative colitis, especially after ileostomy, are uric acid stones.

Unraveling the formation of HCPH(X2A') molecules in extraterrestrial environments: crossed molecular beam study of the reaction of carbon atoms, C(3Pj), with phosphine, PH3(X1A1).

The reaction between ground state carbon atoms, C(3P(j)), and phosphine, PH3(X(1)A1), was investigated at two collision energies of 21.1 and 42.5 kJ mol(-1) using the crossed molecular beam technique. The chemical dynamics extracted from the time-of-flight spectra and laboratory angular distributions combined with ab initio calculations propose that the reaction proceeds on the triplet surface via an addition of atomic carbon to the phosphorus atom. This leads to a triplet CPH3 complex. A successive hydrogen shift forms an HCPH2 intermediate. The latter was found to decompose through atomic hydrogen emission leading to the cis/trans-HCPH(X(2)A') reaction products. The identification of cis/trans-HCPH(X(2)A') molecules under single collision conditions presents a potential pathway to form the very first carbon-phosphorus bond in extraterrestrial environments like molecular clouds and circumstellar envelopes, and even in the postplume chemistry of the collision of comet Shoemaker-Levy 9 with Jupiter.

Sensitivity enhancement for nitrophenols using cationic surfactant-modified activated carbon for solid-phase extraction surface-assisted laser desorption/ionization mass spectrometry.

Previous work has demonstrated that a combination of solid-phase extraction with surface-assisted laser desorption/ionization (SPE-SALDI) mass spectrometry can be applied to the determination of trace nitrophenols in water. An improved method to lower the detection limit of this hyphenated technique is described in this present study. Activated carbon powder is used as both the SPE adsorbent and the SALDI solid in the analysis by SPE-SALDI. The surface of the activated carbon is modified by passing an aqueous solution of a cationic surfactant through the SPE cartridge. The results demonstrate that the sensitivity for nitrophenols in the analysis by SPE-SALDI can be improved by using cationic surfactants to modify the surface of the activated carbon. The detection limit for nitrophenols is about 25 ppt based on a signal-to-noise ratio of 3 by sampling from 100 mL of solution.

Barrett's esophagus in patients with symptomatic reflux esophagitis.

We evaluated the frequency with which Barrett's esophagus (BE) occurs in patients with symptomatic reflux esophagitis, and compared the clinical endoscopic and manometric features of patients with Barrett's esophagus with those of patients who had non-Barrett's esophagitis (NBE). The effect of 6 months' medical treatment on BE patients was reevaluated by repeating manometry, endoscopy, and biopsy. Esophageal manometry was performed by perfusion technique and endoscopic biopsies were obtained. There were 180 patients; 20 (11%) were found to have BE. The vast majority of BE patients were caucasians. BE patients had symptoms of gastroesophageal reflux for a longer time than did NBE patients. Mean lower esophageal sphincter pressure in BE patients was lower than that in NBE patients. On medical treatment, the severity of esophagitis as judged by endoscopic criteria in BE patients was reduced, but there was no increase in lower esophageal sphincter pressure and no regression of the columnar epithelium.

Gallium-67 scanning in endogenous Klebsiella endophthalmitis with unknown primary focus.

A whole-body gallium-67 (Ga-67) scan of a 61-y-old male with diabetes mellitus who suffered from endogenous Klebsiella endophthalmitis is reported. The scan revealed right orbital and lower abdominal lesions. Urinary analysis revealed pyuria. The causes of endogenous Klebsiella endophthalmitis and the usefulness of Ga-67 are discussed.