Molecular fluorescence from H2TBP porphyrin film on Ag substrate excited by tunneling electrons

Molecular fluorescence from H(2)TBP porphyrin (H(2)TBPP) films on Ag substrate is excited by a scanning tunneling microscope (STM) at ambient conditions. The molecular films are prepared by spin-casting method. The thickness of films can be controlled by the times of dropping H(2)TBPP solution. Molecular fluorescence of as-above prepared H(2)TBPP films with 4-14nm thickness at both polarities of applied bias voltage are well defined in good matching with its photoluminescence spectrum, which suggests the same decay channel associated with the HOMO-LUMO radiative transitions similar to H(2)TBPP/Au. The thickness dependence of light emission intensity of molecular fluorescence has been studied. The results show that for thicker film, molecular fluoresceence tends to be much stronger due to the effective decoupling of the emitter from the metal substrate.     

Growth hormone acts on the synthesis and secretion of alpha-casein in bovine mammary epithelial cells

To study the effect of growth hormone (GH) on the functions of mammary epithelia, we examined the effect of GH on the synthesis and secretion of alpha-casein in a bovine mammary epithelial cell (BMEC) clonal line, which was established from a 26-d-pregnant Holstein heifer. GH receptors (GHR) were observed in the BMEC on the membrane as well as in the cytoplasm. After BMEC were plated onto cell culture inserts, GH stimulated alpha-casein release in both the presence and absence of the lactogenic hormone complex, which included dexamethasone, insulin and prolactin (DIP). DIP enhanced the effect of GH on alpha-casein release. Although alpha(s1-) casein mRNA expression was not detected in untreated control cells, its expression was observed in BMEC in response to the GH, DIP and GH + DIP treatments. Expression was greater for GH and GH + DIP than for just DIP. Expression of GHR mRNA was increased by DIP treatment, while the mRNA expression was little changed by GH treatment. We conclude that GH acts on BMEC and induces the expression of both the alpha-casein gene and protein. GHR gene expression was shown to be regulated by DIP and GHR. GHR may be involved in a synergic effect between GH and DIP on casein secretion. These results suggest that GH, in addition to its widely accepted homeorhetic role in vivo, also can act on the mammary parenchyma, and that the effects of GH on mammary epithelial cells could partly account for the clear galactopoietic effect of recombinant bovine GH seen in lactating dairy cows.     

A handwritten character recognition system using directionalelement feature and asymmetric Mahalanobis distance

This paper presents a precise system for handwritten Chinese and Japanese character recognition. Before extracting directional element feature (DEF) from each character image, transformation based on partial inclination detection (TPID) is used to reduce undesired effects of degraded images. In the recognition process, city block distance with deviation (CBDD) and asymmetric Mahalanobis distance (AMD) are proposed for rough classification and fine classification. With this recognition system, the experimental result of the database ETL9B reaches to 99.42%     

Extracting curved text lines using local linearity of the text line

In order to enhance the ability of document analysis systems, we need a text line extraction method which can handle not only straight text lines but also text lines in various shapes. This paper proposes a new method called Extended Linear Segment Linking (ELSL for short), which is able to extract text lines in arbitrary orientations and curved text lines. We also consider the existence of both horizontally and vertically printed text lines on the same page. The new method can produce text line candidates for multiple orientations. We verify the ability of the method by some experiments as well. Received December 21, 1998 / Revised version September 2, 1999     

Non-destructive, ultrasonic evaluation of meat quality in live Japanese Black steers from coloured images produced by a new ultrasound scanner

An improved colour scanning scope was used for evaluating meat quality (marbling) of live Japanese Black steers. This equipment consisted of a small size ultrasonic probe (2 MHZ) and LCD display. Seventeen fattened Japanese Black cattle were scanned at the region of the 7th rib about one week before slaughter. A picture of the cross-sectional area of the back was obtained immediately after applying the probe and contained 15 colours representing different signal strengths. The time for each scan was 2 seconds. The picture signals were fed into a computer for rapid estimation of fat percentage of the M. longissimus thoracis. After slaughter, the fat content and chemical characteristics were determined on the M. longissimus thoracis obtained from the same rib section. The range of fat content was 7.0 to 23.7% (average 18.47%). A high correlation coefficient (r = 0.90; r.s.d. = 2.01%) was obtained between actual fat percentage of the M. longissimus thoracis and colour-scanning scope SR200 estimates based on the percentage of the weak blue dot(1) in the echo. Estimates of the subcutaneous fat thickness and the cross-sectional area of M. longissimus thoracis from the scans were in good agreement with the actual carcass measurements (r = 0.69; r.s.d=0.52 cm and r = 0.81; r.s.d. = 4.26 cm(2), respectively). These results show that the new colour scanning scope is a useful instrument for estimating meat quality (marbling) in live cattle.     

Multi-objective optimization minimizing cost and life cycle emissions of stand-alone PV–wind–diesel systems with batteries storage

This paper describes an application of the Strength Pareto Evolutionary Algorithm to the multi-objective optimization of a stand-alone PV–wind–diesel system with batteries storage. The objectives to be minimized are the levelized cost of energy (LCOE) and the equivalent carbon dioxide (CO₂) life cycle emissions (LCE).     

Constitutive chemokine production results in activation of leukocyte function-associated antigen-1 on adult T-cell leukemia cells

Adult T-cell leukemia (ATL) is characterized by massive infiltration of circulating ATL cells into a variety of tissues, a finding often associated with poor prognosis. Leukocyte migration from circulation into tissue depends on integrin-mediated adhesion to endothelium, and integrins are tightly regulated by several stimuli, such as inflammatory chemokines. However, the exact mechanisms that enhance adherence of leukemic cells to the endothelium and infiltration into tissues remain to be fully understood. We investigated the mechanisms of extravasation of leukemic cells using ATL cells and report the following novel features of endogenous chemokine-induced adhesion of ATL cells to the endothelium. ATL cells spontaneously adhered to endothelial cells without exogenous stimulation. Integrin leukocyte function-associated antigen-1 (LFA-1) on ATL cells was spontaneously activated. ATL cells produced high amounts of chemokines, macrophage inflammatory protein-1alpha (MIP-1alpha), and MIP-1beta. Adhesion of ATL cells to endothelial cells and the expression of activated form of LFA-1 were reduced by pretreatment with pertussis toxin, wortmannin, or anti-MIP-1alpha and MIP-1beta antibodies or transfection with antisense of MIP-1alpha or MIP-1beta. Spontaneous polymerization of cytoskeletal F-actin was observed in ATL cells, which was also inhibited by pertussis toxin and wortmannin. We propose that ATL cells adhere to endothelial cells through an adhesion cascade similar to normal leukocytes and that the chemokines produced by ATL cells are involved in triggering integrin LFA-1 through cytoskeletal rearrangement induced by G-protein-dependent activation of phosphoinositide 3-kinases in an autocrine manner. These events result in a strong adhesion of ATL cells to the endothelium and spontaneous transendothelial migration.     

Structural analysis of PVC and PFA carbons prepared at 500-1000 °C based on elemental composition, XRD, and HRTEM

Temperature programmed oxidation (TPO) method to evaluate the structure of carbonaceous materials was proposed in the previous paper, and this method was applied to analyze two sets of carbons derived from PVC and PFA in the temperature range of 500-1000 °C. Amounts of H₂O, CO and CO₂ evolved during oxidation were accurately determined, and they were used to estimate an average size of polyaromatic graphene sheet in PVC and PFA carbons. The size increases with preparation temperature for both series of carbon. The estimated size was compared with those determined by XRD and TEM methods. The size determined by TPO method was much larger than the size determined by XRD and TEM. Each method provides completely different information, which naturally leads to different sizes. Combination of these three methods is quite useful to understand carbon structure. The most remarkable difference between two sets of carbon was the degree of stacking rather than size of graphene sheet. This difference seems to control the reactivity of these two carbons during TPO.     

Power spectral analysis of heart rate variation in diabetic patients with neuropathic foot ulceration

OBJECTIVE: To evaluate the relationship between diabetic autonomic neuropathy and diabetic neuropathic foot ulceration, we used power spectral analysis (PSA) of heart rate variation, which provides the accurate simultaneous quantification of parasympathetic and sympathetic activities, to assess autonomic function in diabetic patients. RESEARCH DESIGN AND METHODS: We studied 55 NIDDM patients including 10 diabetic patients without neuropathy, 23 diabetic patients with neuropathy and no history of foot ulceration, and 22 diabetic patients with neuropathic foot ulceration. We performed PSA of 100 R-R intervals at rest and analyzed the results by fast Fourier transformation. RESULTS: The low frequency (LF) power, which reflects sympathetic activity, and the high frequency (HF) power, which reflects parasympathetic (vagal) activity, were inversely correlated with the duration of diabetes and the fasting plasma glucose (FPG) levels. By multiple regression analysis, the FPG remained with significant influence on both LF and HF powers. The LF and HF powers were positively correlated with motor nerve conduction velocity (MCV) and sensory nerve conduction velocity (SCV) in the upper and lower limbs and the coefficient of variation of R-R intervals. The LF and HF powers were significantly reduced in patients with neuropathy and patients with foot ulceration compared with patients without neuropathy. Although the median MCV and SCV were similar between diabetic patients with neuropathy and patients with foot ulceration, both the LF and HF powers were significantly decreased in patients with foot ulceration compared with patients with neuropathy. There was no difference in the value of the LF:HF ratio, an index of sympathovagal balance, among three subgroups. We observed a positive correlation between LF and HF power in all subjects; however, the LF and HF powers were not correlated in the subgroups of patients with foot ulceration. CONCLUSIONS: These results showed that diabetic patients with neuropathic foot ulceration have a greater impairment in spectral indexes of autonomic activity obtained by PSA than patients with neuropathy and no history of foot ulceration, whereas no difference was present in nerve conduction velocities.     

Substrate effect of STM-induced luminescence from porphyrin molecules

We investigated scanning tunneling microscope (STM)-induced luminescence from Meso-tetrakis (3,5-di-tertiarybutyl-phenyl) porphyrin (H₂TBPP) thin films on various metal substrates (copper, platinum and silver) under ambient conditions. Molecular fluorescence similar to the corresponding photoluminescence was observed from the H₂TBPP/Ag and H₂TBPP/Pt, but not H₂TBPP/Cu, depending on the spectra of the surface plasmons of the substrates. The results support the mechanism that intense molecular fluorescence from porphyrin film on the noble metals is a result of enhancement of molecular excitation by substrate surface plasmons.