Two important electric forces, dielectrophoresis (DEP) and electrowetting-on-dielectric (EWOD), are demonstrated by dielectric-coated electrodes on a single chip to manipulate objects on different scales, which results in a dielectrophoretic concentrator in an EWOD-actuated droplet. By applying appropriate electric signals with different frequencies on identical electrodes, EWOD and DEP can be selectively generated on the proposed chip. At low frequencies, the applied voltage is consumed mostly in the dielectric layer and causes EWOD to pump liquid droplets on the millimetre scale. However, high frequency signals establish electric fields in the liquid and generate DEP forces to actuate cells or particles on the micrometre scale inside the droplet. For better performance of EWOD and DEP, square and strip electrodes are designed, respectively. Mammalian cells (Neuro-2a) and polystyrene beads are successfully actuated by a 2 MHz signal in a droplet by positive DEP and negative DEP, respectively. Droplet splitting is achieved by EWOD with a 1 kHz signal after moving cells or beads to one side of the droplet. Cell concentration, measured by a cell count chamber before and after experiments, increases 1.6 times from 8.6 x 10(5) cells ml(-1) to 1.4 x 10(6) cells ml(-1) with a single cycle of positive DEP attraction. By comparing the cutoff frequency of the voltage drop in the dielectric layer and the cross-over frequency of Re(fCM) of the suspended particles, we can estimate the frequency-modulated behaviors between EWOD, positive DEP, and negative DEP. A proposed weighted Re(fCM) facilitates analysis of the DEP phenomenon on dielectric-coated electrodes.

A smartphone-controlled, automated, and portable system was developed for rapid molecular diagnosis of pathogens via the use of a colorimetric loop-mediated isothermal amplification (LAMP) approach on a passive, self-driven microfluidic device.

Nociceptin activation of ORL1 (opioid receptor-like 1 receptor) has been shown to antagonize l receptor-mediated analgesia at the supraspinal level. ORL1 and l-opioid receptor (lR) are co-expressed in several subpopulations of CNS neurons involved in regulating pain transmission. The amino acid sequence of ORL1 also shares a high degree of homology with that of l receptor. Thus, it is hypothesized that ORL1 and lR interact to form the heterodimer and that ORL1/lR heterodimerization may be one molecular basis for ORL1-mediated antiopioid effects in the brain. To test this hypothesis, myc-tagged ORL1 and HA-tagged lR are co-expressed in human embryonic kidney (HEK) Grisel et al. 1996;Mogil et al. 1996;Calo et al. 1998;Wang et al. 1999). It has also been reported that intracerebroventricular administration of [Nphe 1 ]nociceptin(1-13)NH2, a selective ORL1 antagonist, potentiates l receptor agonist-induced analgesia and produces a naloxone-resistant antinociceptive effect (Calo et al. 2000a). These results suggest that the functional antagonism of l receptor-mediated analgesia by ORL1 is tonically active at the supraspinal level.A growing number of biochemical, biophysical and functional investigations demonstrated that heterodimerization of distinct G protein-coupled receptors occurs in the plasma membrane and that pharmacological and signaling Received April 20, 2004; revised manuscript received August 13, 2004; accepted October 6, 2004. Address correspondence and reprint requests to Hung-Li Wang, Department of Physiology, Chang Gung University School of Medicine, Kwei-San, Tao-Yuan, Taiwan. E-mail: hlwns@mail.cgu.edu.twAbbreviations used: AT1-R, type 1 angiotensin II receptor; B2-R, type 2 bradykinin receptor; CHO, Chinese hamster ovary; DA, dopamine; DAMGO, [D-Ala 2 ,N-methyl-Phe 4 ,Gly-ol 5 ]enkephalin; GRK2, G proteincoupled receptor kinase 2; HEK, human embryonic kidney; MAPK, mitogen-activated protein kinase; lR, l-opioid receptor; ORL1, opioid receptor-like 1 receptor; PAG, periaqueductal gray; PBS, phosphatebuffered saline; SDS-PAGE, sodium dodecyl sulphate polyacrylamide gel electrophoresis.

The physiological importance of connexin-26 (Cx26) gap junctions in regulating auditory function is indicated by the finding that autosomal recessive DFNB1 deafness is associated with mutations of the Cx26 gene. To investigate the pathogenic role of Cx26 mutation in recessive hearing loss, four putative DFNB1 Cx26 mutants (V84L, V95M, R127H, and R143W) were stably expressed in N2A cells, a communication-deficient cell line. In N2A cells expressing (R127H) Cx26 gap junctions, macroscopic junctional conductance and ability of transferring neurobiotin between transfected cells were greatly reduced. Despite the formation of defective junctional channels, immunoreactivity of (R127H) Cx26 was mainly localized in the cell membrane and prominent in the region of cell-cell contact. Mutant (V84L), (V95M), or (R143W) Cx26 protein formed gap junctions with a junctional conductance similar to that of wild-type Cx26 junctional channels. (V84L), (V95M), or (R143W) Cx26 gap junctions also permitted neurobiotin transfer between pairs of transfected N2A cells. The present study suggests that (R127H) mutation associated with hereditary sensorineural deafness results in the formation of defective Cx26 gap junctions, which may lead to the malfunction of cochlear gap junctions and hearing loss. Further studies are required to determine the exact mechanism by which mutant (V84L), (V95M), and (R143W) Cx26 proteins, which are capable of forming functional homotypic junctional channels in N2A cells, cause the cochlear dysfunction and sensorineural deafness.

Physiologically, the thoracic (THO) and abdominal (ABD) movement signals, captured using wearable piezo-electric bands, provide information about various types of apnea, including central sleep apnea (CSA) and obstructive sleep apnea (OSA). However, the use of piezo-electric wearables in detecting sleep apnea events has been seldom explored in the literature. This study explored the possibility of identifying sleep apnea events, including OSA and CSA, by solely analyzing one or both the THO and ABD signals. An adaptive non-harmonic model was introduced to model the THO and ABD signals, which allows us to design features for sleep apnea events. To confirm the suitability of the extracted features, a support vector machine was applied to classify three categories - normal and hypopnea, OSA, and CSA. According to a database of 34 subjects, the overall classification accuracies were on average 75.9%±11.7% and 73.8%±4.4%, respectively, based on the cross validation. When the features determined from the THO and ABD signals were combined, the overall classification accuracy became 81.8%±9.4%. These features were applied for designing a state machine for online apnea event detection. Two event-byevent accuracy indices, S and I, were proposed for evaluating the performance of the state machine. For the same database, the S index was 84.01%±9.06%, and the I index was 77.21%±19.01%. The results indicate the considerable potential of applying the proposed algorithm to clinical examinations for both screening and homecare purposes.