A photodiode amplifier system for pulse-by-pulse intensity measurement of an x-ray free electron laser

We have developed a single-shot intensity-measurement system using a silicon positive-intrinsic-negative (PIN) photodiode for x-ray pulses from an x-ray free electron laser. A wide dynamic range (10(3)-10(11) photons/pulse) and long distance signal transmission (>100 m) were required for this measurement system. For this purpose, we developed charge-sensitive and shaping amplifiers, which can process charge pulses with a wide dynamic range and variable durations (ns-μs) and charge levels (pC-μC). Output signals from the amplifiers were transmitted to a data acquisition system through a long cable in the form of a differential signal. The x-ray pulse intensities were calculated from the peak values of the signals by a waveform fitting procedure. This system can measure 10(3)-10(9) photons/pulse of ~10 keV x-rays by direct irradiation of a silicon PIN photodiode, and from 10(7)-10(11) photons/pulse by detecting the x-rays scattered by a diamond film using the silicon PIN photodiode. This system gives a relative accuracy of ~10(-3) with a proper gain setting of the amplifiers for each measurement. Using this system, we succeeded in detecting weak light at the developmental phase of the light source, as well as intense light during lasing of the x-ray free electron laser.     

Oxynitridation using radical-oxygen and -nitrogen for high-performance and highly reliable n/pFETs

We report the importance of oxynitridation using radical-oxygen and -nitrogen to form a low-leakage and highly reliable 1.6-nm SiON gate-dielectric without performance degradation in n/pFETs. It was found that oxidation using radical-oxygen forms high-density 1.6-nm SiO/sub 2/, which is ten times more reliable than low-density SiO/sub 2/ formed by oxygen-ions in n/pFETs and is suitable for the base layer of nitridation. Nitrifying SiO/sub 2/ using radical-nitrogen facilitates surface nitridation of SiO/sub 2/, maintains an ideal SiON-Si substrate interface, and reduces the gate leakage current. The 1.6-nm SiON formed by radical-oxygen and -nitrogen produces comparable drivability in n/pFETs, has one and half orders of magnitude less gate leakage in nFETs, one order of magnitude less gate leakage in pFETs, and is ten times more reliable in n/pFETs than 1.6-nm SiO/sub 2/ formed by radical-oxygen.     

Insertion of prosthetic tricuspid valve two years after the tricuspid valvulectomy

A case of a 14-year-old boy who underwent a prosthetic tricuspid valve insertion two years after the tricuspid valvulectomy due to intractable right-sided active endocarditis is presented. At the initial operation, the tricuspid valve was thoroughly resected because of marked destruction and attachment of vegetations, and a concomitant ventricular septal defect was directly closed. When a prosthetic valve was placed in the tricuspid portion, a semicircular Dacron patch was attached to the right side of the interventricular septum in a fashion of up-chord and down-arc to cover the bundle of His. The straight edge of the patch was located near the AV node and was not sutured to the tricuspid valve annulus. A 31 mm of CarboMedics prosthetic valve was sutured to the tricuspid valve annulus and to the free edge of the patch at the position near the AV node to prevent AV block. Postoperative course was uneventful and ECG showed regular sinus rhythm.     

An enzyme-based microfluidic biofuel cell using vitamin K3-mediated glucose oxidation

Viamin K₃-modified poly-l-lysine (PLL-VK₃) was synthesized and used as the electron transfer mediator during catalytic oxidation of NADH by diaphorase (Dp) at the anode of biofuel cell. PLL-VK₃ and Dp were co-immobilized on an electrode and then coated with NAD⁺-dependent glucose dehydrogenase (GDH). The resulting enzymatic bilayer (abbreviated PLL-VK₃/Dp/GDH) catalyzed glucose oxidation. Addition of carbon black (Ketjenblack, KB) into the bilayer enlarged the effective surface area of the electrode and consequentially increased the catalytic activity. An oxidation current of ca. 2 mA cm⁻² was observed when the electrochemical cell contained a stirred 30 mM glucose, 1.0 mM NAD⁺, pH 7.0 phosphate-buffered electrolyte solution. The performance of glucose/O₂ biofuel cells, constructed as fluidic chips with controllable fuel flow and containing a KB/PLL-VK₃/Dp/GDH-coated anode and an Ag/AgCl or a polydimethylsiloxane-coated Pt cathode, were evaluated. The open circuit voltage of the cell with the PDMS-coated Pt cathode was 0.55 V and its maximum power density was 32 μW cm⁻² at 0.29 V when a pH 7.0-buffered fuel containing 5.0 mM glucose and 1.0 mM NAD⁺ was introduced into the cell at a flow rate of 1.0 mL min⁻¹. The cell's output increased as the flow rate increased. During 18 h of continuous operation of the cell with a load of 100 kΩ, the output current density declined by ca. 50%, probably due to swelling of the enzyme bilayer.     

Hepatic resection for advanced carcinoma of the gallbladder

Hepatic resection for advanced carcinoma of the gallbladder must be decided upon based on the modes of cancer spread to the liver. The cystic vein through the liver bed is considered an important route of liver metastasis, because liver metastases of gallbladder carcinoma are found frequently around the liver bed. About 70% of early metastatic foci demonstrated microscopically occur in segments 4a and 5. Resection of segments 4a and 5 is considered to be an adequate range of hepatectomy for patients with subserosal invasion, because early metastatic foci are detected not only in patients with direct invasion of the liver but also in those without direct invasion. For patients with direct liver invasion, various degrees of hepatic resection are needed to comply with the depth of direct invasion. It is necessary to achieve negative surgical margins 2 cm from the tumor. Because cancer cells extend along the Glissonian sheath in patients with hilar invasion, extended right hepatectomy with caudate lobectomy is required in these patients. A future problem is to establish the safety of extended hepatectomy in these patients.     

Feedback system for improving the performance of extended x-ray absorption fine structure measurements

A rapid fine energy tuning method for a double-crystal monochromator (DCM) is developed by combining a feedback control system with a phase sensitive detector. This method maintains both a parallel angle between the first and second crystals of the DCM and the peak of the rocking curve. The method is used to perform a continuous energy scan of the DCM without readjustment of the angle between the two crystals. The time taken by this method to measure the extended x-ray absorption fine structure is 60% of that taken by a conventional procedure.     

Axial force acting on a dielectric sphere in a focused laser beam

We present the detailed behavior of the axial force acting on a dielectric sphere exerted by the optical pressure of a focused Gaussian laser beam. Comparison is made between the numerical results and those calculated from the radiation pressure cross section. There is also a discussion as to whether the expressions for the axial force given in this paper are consistent with the previously reported experimental results. Moreover, a simple experimental method to measure the axial force on a polystyrene sphere suspended in water is demonstrated, and fairly good agreement between theoretical and experimental results was obtained.     

Interrelation of degradation processes of purine nucleotides and their biosynthetic transformation in the blood cells of patients with acute leukemia

It has been shown that the leukemic process shifts the balance of individual enzymatic steps of the purine nucleotide degradation and biosynthesis. In acute lymphoblastic leukosis (ALL) and acute myeloblastic leukosis (AML) the rate of purine degradation, as estimated by the ADA enzyme activity (ES 3.5.4.4.) and PNP (EC 2.4.2.1), exceeds considerably that of their enzymes AMP-DA (EC 3.5.4.6.) and IMP-DH (EC 1.2.1.14.) biosynthesis. The data obtained suggest the existence of differences in the enzymatic program of purine metabolism in the malignant transformation of hematopoietic tissue and in other tumours.     

Unique very low-frequency heart rate variability during deep sleep in humans

We investigate heart rate variability (HRV) in the very low-frequency (VLF) range (0.003-0.04 Hz) during deep sleep in good sleepers. Spectral analysis of HRV during deep sleep reveals consistent peaks at <0.04 Hz. By using wavelet analysis, we find both stationary and nonstationary periodic patterns in the VLF range, the presence of which has been discussed but has not been fully established to date. Although the mechanism(s) behind the unique VLF oscillations remain to be fully explored, we conjecture that there is an endogenous rhythmic component in human HRV in the VLF range. Further, our results also suggest a need for caution in the interpretation of the VLF spectral power in HRV during deep sleep.