Bio-Inspired Distributed Transmission Power Control Considering QoS Fairness in Wireless Body Area Sensor Networks.

Recently, the development of wireless body area sensor network (WBASN) has accelerated due to the rapid development of wireless technology. In the WBASN environment, many WBASNs coexist where communication ranges overlap with each other, resulting in the possibility of interference. Although nodes in a WBASN typically operate at a low power level, to avoid adversely affecting the human body, high transmission rates may be required to support some applications. In addition to this, since many varieties of applications exist in the WBASN environment, each prospective user may have different quality of service (QoS) requirements. Hence, the following issues should be considered in the WBASN environment: (1) interference between adjacent WBASNs, which influences the performance of a specific system, and (2) the degree of satisfaction on the QoS of each user, i.e., the required QoS such as user throughput should be considered to ensure that all users in the network are provided with a fair QoS satisfaction. Thus, in this paper, we propose a transmission power adjustment algorithm that addresses interference problems and guarantees QoS fairness between users. First, we use a new utility function to measure the degree of the satisfaction on the QoS for each user. Then, the transmission power of each sensor node is calculated using the Cucker-Smale model, and the QoS satisfaction of each user is synchronized dispersively. The results of simulations show that the proposed algorithm performs better than existing algorithms, with respect to QoS fairness and energy efficiency.

Mechanical Durability of Flexible Printed Circuit Boards Containing Thin Coverlays Fabricated with Poly(Amide-Imide-Urethane)/Epoxy Interpenetrating Networks.

Because electronics are becoming flexible, the demand for techniques to manufacture thin flexible printed circuit boards (FPCBs) has increased. Conventional FPCBs are fabricated by attaching a coverlay film (41 µm) onto copper patterns/polyimide (PI) film to produce the structure of coverlay/Cu patterns/PI film. Given that the conventional coverlay consists of two layers of polyimide film and adhesive, its thickness must be reduced to generate thinner FPCBs. In this study, we fabricated 25-µm-thick poly(amide-imide-urethane)/epoxy interpenetrating networks (IPNs) to replace the thick conventional coverlay. Poly(amide-imide-urethane) (PAIU) was synthesized by reacting isocyanate-capped polyurethane with trimellitic anhydride and then mixed with epoxy resin to produce PAIU/epoxy IPNs after curing. Thanks to the soft segments of polyurethane, the elongation of PAIU/epoxy IPNs increased with increasing PAIU content and reached over 200%. After confirming the excellent thermal stability and chemical resistance of the PAIU/epoxy IPNs, we fabricated FPCBs by equipping them as coverlays. The mechanical durability of the FPCBs was evaluated through an MIT folding test, and the FPCB fabricated with PAIU/ep-2 was stable up to 164 folding cycles because of the balanced mechanical properties.

Successful control of norovirus outbreak in a pediatric ward with multi-bed rooms.

BACKGROUND: Norovirus outbreaks in health care facilities are difficult to prevent and control. METHODS: We describe a norovirus outbreak that occurred in a single pediatric ward with multi-bed rooms. RESULTS: The outbreak began with 4 clustered cases with acute diarrhea in a pediatric ward between December 22 and 25, 2017. A total of 10 cases were identified during the outbreak, with a cumulative incidence of 8.77%. The median age of the cases was 10 months. Symptoms lasted for a median of 7.5 days, and norovirus shed in stool for a median of 19.5 days. The first 5 cases consecutively developed diarrhea; 4 of them were in the same room. The sixth case, which was linked with the clustered cases, had stayed in the intensive care unit and infected 3 other patients during the stay. After these 4 cases were transferred back to the ward, an additional patient was infected. Strict infection control measures were implemented, and the outbreak was successfully terminated 24 days after the initial case. CONCLUSIONS: Controlling norovirus outbreak in a pediatric ward with multi-bed rooms is challenging. Early detection of the outbreak and prompt implementation of strict infection control measures are critical.

Crack-induced Ag nanowire networks for transparent, stretchable, and highly sensitive strain sensors.

Crack-based strain sensor systems have been known for its high sensitivity, but suffer from the small fracture strain of the thin metal films employed in the sensor which results in its negligible stretchability. Herein, we fabricated a transparent (>90% at 550 nm wavelength), stretchable (up to 100%), and sensitive (gauge factor (GF) of 30 at 100% strain) strain gauge by depositing an encapsulated crack-induced Ag nanowire (AgNW) network on a hydroxylated poly(dimethylsiloxane) (PDMS) film. Stretching the encapsulated AgNWs/PDMS resulted in the formation of a percolation network of nanowire ligaments with abundant percolation paths. The encapsulating polymer was designed to adhere strongly to both the AgNW and PDMS. The improved adhesion ensured the resistance of the crack-induced network of AgNWs varied reversibly, stably, and sensitively when stretched and released, at strains of up to 100%. The developed sensor successfully detected human motions when applied to the skin.

Ultra-thin and smooth transparent electrode for flexible and leakage-free organic light-emitting diodes.

A smooth, ultra-flexible, and transparent electrode was developed from silver nanowires (AgNWs) embedded in a colorless polyimide (cPI) by utilizing an inverted film-processing method. The resulting AgNW-cPI composite electrode had a transparency of >80%, a low sheet resistance of 8 Ω/□, and ultra-smooth surfaces comparable to glass. Leveraging the robust mechanical properties and flexibility of cPI, the thickness of the composite film was reduced to less than 10 µm, which is conducive to extreme flexibility. This film exhibited mechanical durability, for both outward and inward bending tests, up to a bending radius of 30 µm, while maintaining its electrical performance under cyclic bending (bending radius: 500 µm) for 100,000 iterations. Phosphorescent, blue organic light-emitting diodes (OLEDs) were fabricated using these composites as bottom electrodes (anodes). Hole-injection was poor, because AgNWs were largely buried beneath the composite's surface. Thus, we used a simple plasma treatment to remove the thin cPI layer overlaying the nanowires without introducing other conductive materials. As a result, we were able to finely control the flexible OLEDs' electroluminescent properties using the enlarged conductive pathways. The fabricated flexible devices showed only slight performance reductions of <3% even after repeated foldings with a 30 µm bending radius.

Transition to an irreversible state of senescence in HeLa cells arrested by repression of HPV E6 and E7 genes.

Inhibition of human papillomavirus (HPV) E6 and E7 transcription by means of the E2 protein of bovine papillomavirus 1 (BPV1) has been shown to induce acute growth arrest in HPV-positive cervical carcinoma cells. This state of arrest is marked by the expression of senescence phenotypes including SA beta-Gal activity and lipofuscin accumulation. In this study, we examined the reversibility of these phenotypes by exogenously expressing the E6 and E7 genes into HeLa cells growth-arrested by the depletion of E6/E7. Re-expression of E7 (but not E6) in 2 days following E2 transduction induced the cells to resume growth. The proliferating cells manifested the phenotype of untreated HeLa cells, suggesting that E7 is the major factor responsible for the continued proliferation and the suppression of the senescence phenotype in cervical carcinoma cells. However, E7 in 5 days following E2 transduction did not prevent HeLa cells from entering the senescent state, indicating that the arrested state becomes irreversible. Our results suggest that, upon depletion of the viral oncoproteins, a senescent state is irreversibly induced in HeLa cells after a period of commitment. The status and cellular location of certain factors involved in signal transduction and cell cycle control was altered as well along with this irreversibility transition.

Prepubertal unilateral gynecomastia in the absence of endocrine abnormalities.

Gynecomastia is defined as the excessive development of breast tissue in males, which can occur as unilateral or bilateral. Although the overall prevalence of gynecomastia is 40%-65%, the prepubertal unilateral gynecomastia in the absence of endocrine abnormalities is unusual, with only a few case reports in literature. Idiopathic gynecomastia in prepuberty is benign but a diagnosis of exclusion. We here report two cases of healthy prepubertal boys aged 8.8 and 9.6 years old, respectively, presented with painful palpable mass in their unilateral breast. Breast tissue with glandular proliferation was confirmed on ultrasonography. Serum levels of estradiol, testosterone, and other laboratory findings were within normal range. They seem to have the prepubertal idiopathic gynecomastia but further follow-up to see their progression is needed.

Enhanced light extraction from organic light emitting diodes by micrometer-sized buckles.

The simple ways for creating buckled structures to enhance the light extraction from OLED devices have been investigated. The buckling instability was observed when the ITO was deposited on the polymer-coated glass by sputtering. The textured surface of the ITO layer after buckling was characterized by an atomic force microscopy. The wavelength of the resulting buckled structure was a few microns in a size. The buckling was easily modified by adjusting the pressure of the argon gas during the sputter deposition of ITO layer. The buckled ITO layer was used for fabricating OLED devices. The reduction in the operating voltage for the OLED with the buckled ITO anode was observed. The current and power efficiencies for the OLED with the buckeld structure were 5% and 44% higher than those for the conventional OLED. The broader light distribution was observed in the OLED with buckling when the angular dependence of the light intensity was measured.

Tunable assembly of hydrophobic and cationic charged Fe3O4/SiO2 colloids.

The hydrophobic and cationic Fe3O4/SiO2 nanoparticles (NPs) were synthesized by coating the Fe3O4 nanoparticles with silica followed by the silanization reaction. The monodisperse nanoparticles were separated under magnetic forces and characterized by FE-SEM and FT-IR. Interestingly, the hydrophobic and cationic NPs were well dispersed in polar solvents (ethanol and propylene carbonate) and a nonpolar solvent (chloroform). The structural colors induced by the assembly of the NPs were changed according to the magnetic forces. The repulsive forces originated from the combination of the cationic charges and hydrophobic groups were strong enough to overcome the magnetic attractive forces between particles. The electrophoretic behavior of the NPs was investigated as well. For preparing devices, the polar and nonpolar solutions of the cationic NPs were injected into the cells with two ITO-coated glasses which were separated by 100 µm. The reversible color changes were observed on the cathode under the electric field suggesting that the Fe3O4/SiO2 nanoparticles were modified with cationic groups.

Effect of Ag nanowire addition into nanoparticle paste on the conductivity of Ag patterns printed by gravure offset method.

This paper focuses on the effect of Ag nanowire addition into a commercial Ag nanopaste and the printability evaluation of the mixed paste by the gravure offset printing methodology. Ag nanowires were synthesized by a modified polyol method, and a small amount of them was added into a commercial metallic paste based on Ag nanoparticles of 50 nm in diameter. Two annealing temperatures were selected for comparison, and electrical conductivity was measured by four point probe method. As a result, the hybrid mixture could be printed by the gravure offset method for patterning fine lines up to 15 µm width with sharp edges and scarce spreading. The addition of the Ag nanowires was significantly efficient for enhancement of electrical conductivity of the printed lines annealed at a low temperature (150 degrees C), while the effect was somewhat diluted in case of high temperature annealing (200 degrees C). The experimental results were discussed with the conduction mechanism in the printed conductive circuits with a schematic description of the electron flows in the printed lines.

The global transcriptional effects of the human papillomavirus E6 protein in cervical carcinoma cell lines are mediated by the E6AP ubiquitin ligase.

The function of the human papillomavirus (HPV) E6 protein that is most clearly linked to carcinogenesis is the targeted degradation of p53, which is dependent on the E6AP ubiquitin ligase. Additional functions have been attributed to E6, including the stimulation of telomerase activity and the targeted degradation of other cellular proteins, but in most cases it is unclear whether these activities are also E6AP dependent. While E6 clearly influences the transcriptional program of HPV-positive cell lines through the inactivation of p53, it has been shown that at least a subset of its p53-independent functions are also reflected in the transcriptional program. For this study, we have determined the extent to which E6AP is involved in mediating the set of E6 functions that impact on the global transcriptional program of HPV-positive cell lines. The transcriptional profiles of approximately 31,000 genes were characterized for three cell lines (HeLa, Caski, and SiHa cells) after small interfering RNA (siRNA)-mediated silencing of E6 or E6AP. We found that E6 and E6AP siRNAs elicited nearly identical alterations in the transcriptional profile of each cell line. Some of the expression alterations were apparent secondary effects of p53 stabilization, while the basis of most other changes was not reconcilable with previously proposed E6 functions. While expression changes of the TERT gene (telomerase catalytic subunit) were not revealed by the array, telomerase repeat amplification protocol assays showed that both E6 and E6AP knockouts resulted in a suppression of telomerase activity. Together, these results suggest that E6AP mediates a broad spectrum of E6 functions, including virtually all functions that impact on the transcriptional program of HPV-positive cell lines.

Induction of senescence-like state and suppression of telomerase activity through inhibition of HPV E6/E7 gene expression in cells immortalized by HPV16 DNA.

The E6 and E7 oncoproteins of human papillomavirus (HPV) play a major role in the development of cervical carcinoma. In this study, a recombinant adenovirus that expresses the bovine papillomavirus (BPV) E2, which has been shown to inhibit HPV early gene expression, was delivered to two HPV-immortalized cell lines as well as CaSki, a cervical carcinoma cell line. We tested whether the carcinoma and the immortal cells were equally affected by the expression of BPV E2. In all cell lines, BPV E2-mediated inhibition of HPV E6/E7 expression caused a dramatic suppression of cell growth, being preceded by the activation of the p53-Rb growth-inhibitory pathway, and a decrease in hTERT mRNA expression and telomerase activity. This suggests that the HPV E6 and E7 proteins are required not only for induction of the proliferative phenotype and telomerase activity, but also for their maintenance. In both the carcinoma and the immortal lines, the number of cells with enlarged cytoplasm and senescence-associated beta-galactosidase activity, which are markers for cellular senescence, was significantly increased. These results suggest that a senescence program exists in cells immortalized by HPV DNA as well as in cervical carcinoma cells.