Identifying rotation and oscillation in surface tension measurement using an oscillating droplet method

We proposed a new approach to identify the frequencies of droplet rotation and m=±2 oscillation that degrade the accuracy of surface tension measurement by an oscillating droplet method. Frequencies of droplet rotation and m=±2 oscillation can be identified by a phase unwrapping analysis of time dependence of the deflection angle for the maximum diameter of the droplet image observed from above. The present method was validated, using test data with given frequencies. © 2008 Wiley Periodicals, Inc. Heat Trans Asian Res, 37(7): 421–430, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20214     

Detection of enzymatically generated hydrogen peroxide by metal-based fluorescent probe

We developed a metal-based fluorescent probe for H(2)O(2) called MBFh1, which has an iron complex as a reaction site for H(2)O(2) and a 3,7-dihydroxyphenoxazine derivative as the fluorescent reporter unit. The iron complex reacts quickly with H(2)O(2) to form oxidants, and then the oxidants convert the closely appended nonfluorescent 3,7-dihydroxyphenoxazine moiety to resorufin in an intramolecular fashion. The quick response to H(2)O(2) allows us to plot the enzymatic evolution of H(2)O(2). A combination of N-acetyl-3,7-dihydroxyphenoxazine and horseradish peroxidase has been frequently used to detect enzymatically generated H(2)O(2), but this method has interference with phenol derivatives. The use of MBFh1 overcomes this drawback.     

Microfluidic device with chemical gradient for single-cell cytotoxicity assays

Here, we report the fabrication of a chemical gradient microfluidic device for single-cell cytotoxicity assays. This device consists of a microfluidic chemical gradient generator and a microcavity array that enables entrapment of cells with high efficiency at 88 ± 6% of the loaded cells. A 2-fold logarithmic chemical gradient generator that is capable of generating a serial 2-fold gradient was designed and then integrated with the microcavity array. High density single-cell entrapment was demonstrated in the device without cell damage, which was performed in 30 s. Finally, we validated the feasibility of this device to perform cytotoxicity assays by exposing cells to potassium cyanide (0-100 μM KCN). The device captured images of 4000 single cells affected by 6 concentrations of KCN and determined cell viability by counting the effected cells. Image scanning of the microcavity array was completed within 10 min using a 10× objective lens and a motorized stage. Aligning cells on the microcavity array eases cell counting, observation, imaging, and evaluation of singular cells. Thus, this platform was able to determine the cytotoxicity of chemicals at a single-cell level, as well as trace the cytotoxicity over time. This device and method will be useful for cytotoxicity analysis and basic biomedical research.     

Thoracoabdominal aortic repair without using assisted bypass

A 41-year-old man, who had undergone descending aortic repair following rupture of the DeBakey type III aortic dissection, underwent thoracoabdominal aneurysm repair 1 year after the first surgery. The operation was performed by partial-clamping and single crossclamping without using assisted bypass or shunt, in order to minimize bleeding ensuing the re-thoracotomy and dissection between lung and the graft.     

Cutting plane methods for Lagrangian relaxation‐based unit commitment algorithm

In this paper, we study cutting plane methods for a Lagrangian relaxation‐based unit commitment algorithm. In the algorithm, nondifferentiable optimization methods can be applied to optimize the dual function, and a subgradient method which needs parameter tuning and has some drawbacks such as computational inefficiency and oscillating behavior is commonly used. The cutting plane method and the central cutting plane method are applied to the algorithm and implemented using reoptimization techniques. A numerical example shows that both methods are accelerated by the reoptimization techniques and have good convergence without parameter tuning. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 141(3): 17–29, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10066     

Self oscillation phenomena of turbulent jets in a channel

A new method based on the Coanda effect for self oscillation of a circular jet bounded by rectangular enclosure is suggested. The experiments in both air and water reveal regions of stable oscillation wherein relationships are obtained between the Strouhal number and the shape factor of the channel. This oscillation method can also be used to mix different liquids in a vessel. For such applications, an improvement of mixing by oscillation is shown by means of a residual concentration diagram for a salt solution.     

Clonidine reduces dopamine and increases GABA in the nucleus accumbens: an in vivo microdialysis study

The spectrum of infectious disease (ID) emergencies in hospitalized patients was assessed in a prospective study of 3,626 inpatient ID consultations in a 1,350-bed teaching hospital. ID emergencies, defined by a need or anticipated need for advanced life support or by irreversible organ damage leading to permanent functional loss, were encountered in 175 patients. Infections of the central nervous system (26.3%), cardiovascular system (14.9%), alimentary system (13.1%), and lower respiratory tract (7.4%) and adverse reactions to antimicrobial agents (7.4%) were most common. In 18.9% of the cases, the referring clinicians were unaware of the emergency at the time of referral. Drug reactions (46.1%), severe alimentary and peritoneal infections (32.0%), upper respiratory tract infections (28.6%), and skin and soft-tissue infections (27.3%) were most frequently missed. The emergency ID conditions were not recognized because they had an atypical presentation (51.5%), were not commonly seen in the referring specialty (24.2%), were due to rare organisms (15.2%), or had unusual anatomical sites of involvement (9.1%). A close liaison between clinicians and the ID team is crucial for recognition of ID emergencies at their early stages so that appropriate investigations and management can be instituted expediently, before the occurrence of irreversible damage.     

Pulsed laser focusing for triggering arc discharge in an arc welding system

In tungsten inert gas (TIG) arc welding systems, arc plasma is generated between the cathode (tungsten rod) and anode (workpiece).¹ Availability of a dependable technique for triggering arc discharge is indispensable for production processes using arc welding. Typical conventional triggering techniques include the high-frequency, high-voltage and touch-start methods. The high-frequency and high-voltage methods involve arc discharge being triggered through ionization of the gas present between the electrodes by means of a conventional high-frequency generator or high-voltage DC generator.² The high-frequency method, however, may possibly disrupt operation of peripheral computer systems, whereas the high-voltage method involves suitable electric circuits being arranged inside the power source to prevent high voltage-related accidents.^{2, 3} After the rod is lowered to make contact with the workpiece in the touch-start method, it is quickly withdrawn to trigger the arc. This method obviates the need for any power source other than the arc welding power source. An important advantage of the touch-start method therefore is its simplicity. When the rod is withdrawn, however, part of it (tungsten) may sustain melt-through to the workpiece in a way that adversely affects weld quality. This is a disadvantage of the touch-start method.₃     

Host genes affecting survival period of chemically induced bladder cancer in mice

Treatment of C57BL/6 J (B6) and NON male mice with N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) resulted in a high incidence of bladder cancer. The mean survival period, however, differed significantly by strain: 481+/-219 days in B6 (n = 31) and 203+/-119 days in NON (n = 30) (P < 0.0001). Major causes of death were renal failure due to obstruction of the urinary tract, or local invasion of tumors. The fact that the BBN-treated NON x B6 reciprocal F1 mice had survival periods as short as those of the parental NON mice suggests a genetically dominant susceptibility in NON or recessive resistance in B6. A linkage analysis of 248 back-cross mice to B6 suggested at least two quantitative trait loci determining the length of the survival period: one was mapped close to D2Mit260 (logarithm of odds, LOD, score 2.21), a microsatellite marker locus 83 cM from the centromere on chromosome 2, and another was close to D6Mit159, 7 cM from the centromere on chromosome 6 (LOD score 2.51).     

100 Å-thick tunnel junction by double impurity doping liquid phase epitaxy for V-band TUNNETT oscillation

The tunnel injection transit time (TUNNETT) diodes with p⁺p⁺n⁺n⁻n⁺ structure were fabricated by liquid phase epitaxy (LPE). About 100 Å tunnel junction (p⁺n⁺) was successfully prepared by the double impurity diffusion of Ge and S during LPE growth. Continuous wave (CW) oscillation was realized at 51.520 GHz in the V-band cavity with the phase noise of −60 dBc/Hz at 1 kHz bandwidth.