Composite organic-inorganic nanoparticles (COINs) with chemically encoded optical signatures

To obtain a coding system for multiplex detection, we have developed a method to synthesize a new type of nanomaterial called composite organic-inorganic nanoparticles (COINs). The method allows the incorporation of a broad range of organic compounds into COINs to produce surface enhanced Raman scattering (SERS)-like spectra that are richer in variety than fluorescence-based signatures. Preliminary data suggest that COINs can be used as Raman tags for multiplex and ultrasensitive detection of biomolecules.     

Helicobacter pylori risk associated with sibship size and family history of gastric diseases in Japanese adults

BACKGROUND: Data on whether long-acting somatostatin analogue octreotide causes or prevents pancreatic injury following endoscopic retrograde cholangiopancreatography (ERCP) are controversial. AIM: This multicentre, prospective trial studied the effect of octreotide on pancreatic injury in a large unselected group of patients after ERCP and endoscopic sphincterotomy. METHODS: The study was carried out in a prospective random manner on 2102 patients in 11 endoscopic centres. Patients in the study received 0.1 mg octreotide acetate and those in the control group received isotonic sodium chloride, subcutaneously before and 45 min after ERCP. Pancreatic injury was assessed by clinical symptoms such as pain, fever and abdominal tenderness. Serum amylase and blood sugar were determined prior to, and 6 and 24 h after the endoscopic procedure. RESULTS: Data from 599 patients in the study group and 600 in the control group were included in the final evaluation. When all the patients were considered, octreotide did not induce pancreatic injury as assessed by clinical symptoms, and diminished the increase of serum amylase levels following ERCP. However, when subgroups of patients were studied, the frequency of increased amylase levels decreased significantly in patients with chronic obstructive pancreatitis and in patients who underwent endoscopic sphincterotomy (P < 0.01). The peak serum glucose level was higher in the treated group when compared to the controls. CONCLUSION: The prophylactic use of long-acting somatostatin does not alter the frequency of post-ERCP pancreatic injury, but it may diminish the rate of increased serum amylase levels in patients with chronic obstructive pancreatitis and also in those with an endoscopic sphincterotomy.     

Rank-ordered regulation of motor units

Myoelectric signals were detected from the tibialis anterior muscle of 5 subjects with a quadrifilar needle electrode while the subjects generated isometric forces that increased linearly with time (10% of maximal voluntary contraction/s) up to maximal voluntary level. Motor unit firing rates were studied as a function of force throughout the full range of muscle force output. The relationship between force and firing rate was found to contain three distinct regions. At recruitment and near maximal force levels, firing rates increased more rapidly with force than in the intermediate region. Furthermore, in the regions with rapid increases, the rate of change of firing rate was correlated to the recruitment threshold, with higher recruitment threshold motor units displaying greater rates of change. In the intermediate region, all motor units had similar rates of change of firing rate. A weak positive correlation was found between initial firing rate and recruitment threshold. Firing rates of motor units at any instant were found to be ordered according to the recruitment order: at any given time in the contraction motor units with lower recruitment thresholds had higher firing rates than units with higher recruitment thresholds. Firing rates of all motor units were observed to converge to the same value at maximal forces. Mechanisms underlying motor unit recruitment and firing rate modulation are discussed in the context of a conceptual model.     

Phosphatidylserine specific binding protein in rat brain: purification and characterization

A calcium-independent phosphatidylserine specific binding protein detected on liposome blotting analysis was purified from rat brain and revealed to be identical to myristoylated, alanine-rich C kinase substrate (MARCKS). MARCKS specifically binds to phosphatidylserine but not phosphatidylcholine. The binding of MARCKS to phosphatidylserine was abolished on protein kinase C-dependent phosphorylation. Since bacterially expressed MARCKS also specifically binds to phosphatidylserine, myristoylation of the N-terminal glycine seems not to be essential for the binding of MARCKS to phosphatidylserine. These data suggest that phosphatidylserine is a membranous target molecule of MARCKS.     

Elastic contact conditions to optimize friction drive of surface acoustic wave motor

The optimum pressing force, namely the preload, for a slider to obtain superior operation conditions in a surface acoustic wave motor have been examined. We used steel balls as sliders. The preload was controlled using a permanent magnet. The steel balls were 0.5, 1, and 2 mm diameter, with the differences in diameter making it possible to change contact conditions, such as the contact pressure, contact area, and deformation of the stator and the slider. The stator transducer was lithium niobate, 128 degrees rotated, y-cut x-propagation substrate. The driving frequency of the Rayleigh wave was about 10 MHz. Hence, the particle vibration amplitude at the surface is as small as 10 nm. For superior friction drive conditions, a high contact pressure was required. For example, in the case of the 1 mm diameter steel ball at the sinusoidal driving voltage of 180 V(peak), the slider speed was 43 cm/sec, the thrust output force was 1 mN, and the acceleration was 23 times as large as the gravitational acceleration at a contact pressure of 390 MPa. From the Hertz theory of contact stress, the contact area radius was only 3 mum. The estimation of the friction drive performance was carried out from the transient traveling distance of the slider in a 3 msec burst drive. As a result, the deformation of the stator and the slider by the preload should be half of the vibration amplitude. This condition was independent of the ball diameter and the vibration amplitude. The output thrust per square millimeter was 50 N, and the maximum speed was 0.7 m/sec. From these results, we conclude that it is possible for the surface acoustic wave motor to have a large output force, high speed, quick response, long traveling distance, and a thin micro linear actuator.     

Ground object recognition and segmentation from aerial image‐based 3D point cloud

Several attempts have been made to grasp three‐dimensional (3D) ground shape from a 3D point cloud generated by aerial vehicles, which help fast situation recognition. However, identifying such objects on the ground from a 3D point cloud, which consists of 3D coordinates and color information, is not straightforward due to the gap between the low‐level point information (coordinates and colors) and high‐level context information (objects). In this paper, we propose a ground object recognition and segmentation method from a geo‐referenced point cloud. Basically, we rely on some existing tools to generate such a point cloud from aerial images, and our method tries to give semantics to each set of clustered points. In our method, firstly, such points that correspond to the ground surface are removed using the elevation data from the Geographical Survey Institute. Next, we apply an interpoint distance‐based clustering and color‐based clustering. Then, such clusters that share some regions are merged to correctly identify a cluster that corresponds to a single object. We have evaluated our method in several experiments in real fields. We have confirmed that our method can remove the ground surface within 20 cm error and can recognize most of the objects.     

Control of precipitation behaviour of Hastelloy-X through grain boundary engineering

Grain boundary engineering (GBE) was employed to control the precipitation behaviour of Hastelloy-X alloy. The precipitate characteristics and thermal stability of grain boundary character distribution (GBCD) were investigated by aging at 850°C. M₆C carbides and µ phases were observed in the matrix and on grain boundaries, respectively. It revealed that the formation of µ phase was closely related to the grain boundary structure. GBCD effectively suppressed the nucleation and coarsening of µ phases on the grain boundaries. Owing to the Mo depletion in the vicinity of random grain boundary, the formation of the precipitates was inhibited on the adjacent grain boundaries. The thermal stability of the GBE-optimised microstructure was confirmed at 850°C for 720?h without significant microstructural degradation.     

Pheromonal and kairomonal activities can be separated: synthesis and bioactivity studies of pine bast scale sex pheromones and their analogues

New syntheses were achieved to secure matsuone (1), the pheromone of the pine scale Matsucoccus matsumurae, that of M. feytaudi (2), and that of M. josephi (3). Five analogues (4-8) of 1, 2, and 3 were synthesized and their bioactivities studied. The pheromone analogue 7 showed relatively strong pheromonal activity toward M. josephi, while it was inactive as a kairomone toward the predator Elatophilus hebraicus. Similarly, analogue 8 acted as a pheromone for M. feytaudi, but it did not attract any of its local predators. The M. feytaudi pheromone 2 exhibited strong kairomonal activity toward E. hebraicus, but was not active as a pheromone mimic to attract M. josephi.     

The structure of the core polyol of the ether lipids fromSulfolobus acidocaldarius

The major ether-type lipid structures ofSulfolobus acidocaldarius (ATCC33909) were composed of caldarchaeol and calditoglycerocaldarchaeol. However, the characterization by nuclear magnetic resonance spectroscopy and mass spectrometry showed that the structure of calditol in calditoglycerocaldarchaeol is not nonitol, 2-(1′,2′,3′-trihydroxypropyl)1,2,3,4,5,6-hexahydroxyhexane, but 2-hydroxymethyl-1-(2,3-dihydroxypropoxy),2,3,4,5-cyclopentanetetraol with an ether linkage in the molecule. Such an intermolecular ether linkage was resistant, to BCl₃ treatment, but nonresistant to 57% HI degradation treatment conducted at 100°C for 60 h, producting 2-hydroxymethyl-1,2,3,4,5-cyclopentanepentaol from calditol as reaction product. Further, it was confirmed that the structure of calditol is essentially a derivative of glycerol, and hydrocarbon chains were conjugated to the glycerol-like site in the structure. The calditol with an ether linkage in the molecule suggested an important role regarding the properties of heat-resistance and acid-resistance observed inSulfolobales. Presented at the international workshop on “Molecular Biology and Biotechnology of Extremophiles and Archaebacteria,” Wako, Japan, August 1993.