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Memory T cells exhibit considerable diversity that determines their ability to be protective and their durability. Here, we examined whether changes in T cell heterogeneity contribute to the age-associated failure of immune memory. By screening for age-dependent T cell surface markers, we have identified CD4 and CD8 memory T cell subsets that are unrelated to previously defined subsets of central and effector memory cells. Memory T cells expressing the e cto-5ʹ-nucleotidase CD73 constitute a functionally distinct subset of memory T cells that declines with age. They exhibit many features favorable for immune protection, including longevity and polyfunctionality. They have a low turnover, but are poised to display effector functions and to develop into cells resembling tissue-resident memory T cells (TRM). Upstream regulators of differential chromatin accessibility and transcriptomes include transcription factors that are characteristic for conferring these superior memory features as well as facilitating CD73 expression. CD73 is not just a surrogate marker of these regulatory networks but is directly involved in T cell survival and T RM differentiation Interventions preventing the decline of this T cell subset or increasing CD73 expression have the potential to improve immune memory in older adults.

The present study developed a sizing analysis system for head-related product designs based on the Civilian American and European Surface Anthropometry Resource (CAESAR) database of North Americans. A total of 2299 heads in the CAESAR database were manually edited and 26 anthropometric landmarks were marked on the edited 3D heads to measure 30 anthropometric dimensions related to head-related product designs. The 3D anthropometric sizing analysis system (3D-ASAS) developed in the study provides analysis functions of a sizing system and representative face models by considering a target product, a target population, the number of size categories, and key anthropometric dimensions based on the CAESAR head measurements. Further research to reduce the efforts of manual editing and landmarking of 3D body scan data is discussed for efficient application of the 3D-ASAS to the design process of various wearable products.

SUMMARY Memory T cells exhibit considerable diversity that determines their ability to be protective. Here, we examine whether changes in T cell heterogeneity contribute to the age-associated failure of immune memory. By screening for age-dependent T cell-surface markers, we identify CD4 and CD8 memory T cell subsets that are unrelated to previously defined subsets of central and effector memory cells. Memory T cells expressing the ecto-5ʹ-nucleotidase CD73 constitute a functionally distinct subset of memory T cells that declines with age. They resemble long-lived, polyfunctional memory cells but are also poised to display effector functions and to develop into cells resembling tissue-resident memory T cells (TRMs). Upstream regulators of differential chromatin accessibility and transcriptomes include transcription factors that facilitate CD73 expression and regulate TRM differentiation. CD73 is not just a surrogate marker of these regulatory networks but is directly involved in T cell survival., Graphical Abstract, In brief Fang et al. describe a subset of memory T cells that are long lived, highly functional, and have the ability to differentiate into tissue-residing cells. These cells are characterized by CD73 as a defining cell-surface marker. Decline of this population in older adults may contribute to failing T cell memory.

A wireless IoT device is getting more and more popular. The device may communicate with other devices without any communication infrastructure whenever these devices are sufficiently close. In view of energy consumption, this approach, i.e., infra-less communication is considerably cheaper and more efficient since energy dissipation grows with at least the square of the distance. With this “energy wise” approach, battery-less and contact-less communication nodes are becoming increasingly attractive for future pervasive computing. In this paper, we study important design considerations and technical limitations for realizing such a device, and then we propose D 2 ART ( D irect D ata A ccessing from Passive R FID T ag) that not only performs as a normal passive RFID tag for identification, but also provides rich information such as multimedia to a reader with extreme low power consumption. Our fabricated D 2 ART IC is operational within 7–8 cm at data transmission rate of 5 Mbps by interfacing with a conventional flash memory according to the measurement and post-layout simulation results with reasonable assumptions.

SUMMARY Generation of protective immunity to infections and vaccinations declines with age. Studies in healthy individuals have implicated reduced miR-181a expression in T cells as contributing to this defect. To understand the impact of miR-181a expression on antiviral responses, we examined LCMV infection in mice with miR-181ab1-deficient T cells. We found that miR-181a deficiency delays viral clearance, thereby biasing the immune response in favor of CD4 over CD8 T cells. Antigen-specific CD4 T cells in mice with miR-181a-deficient T cells expand more and have a broader TCR repertoire with preferential expansion of high-affinity T cells than in wild-type mice. Importantly, generation of antigen-specific miR-181a-deficient CD8 effector T cells is particularly impaired, resulting in lower frequencies of CD8 T cells in the liver even at time points when the infection has been cleared. Consistent with the mouse model, CD4 memory T cells in individuals infected with West Nile virus at older ages tend to be more frequent and of higher affinity., Graphical Abstract, In Brief T cell aging in humans is associated with progressive loss in miR-181a, the implications of which for antiviral immunity are unknown. Using mouse models, Kim et al. find that miR-181a deficiency in T cells reproduces many aging features including impaired effector T cell expansion, viral clearance, generation of tissue-residing T cells, and recall responses.

During CD4+ T cell activation, T cell receptor (TCR) signals impact T cell fate, including recruitment, expansion, differentiation, trafficking and survival. To determine the impact of TCR signals on the fate decision of activated CD4+ T cells to become end-stage effector or long-lived memory T-helper 1 (Th1) cells, we devised a deep sequencing-based approach that allowed us to track the evolution of TCR repertoires following acute infection. The transition of effector Th1 cells into the memory pool was associated with a significant decrease in repertoire diversity, and major histocompatibility complex (MHC) Class II tetramer off-rate, but not tetramer avidity, was a key predictive factor in the representation of individual clonal T cell populations at the memory stage. We conclude that stable and sustained interactions with antigen during the development of T-helper 1 (Th1) responses to acute infection are a determinative factor in promoting the differentiation of Th1 memory cells.

A new and efficient push–pull organic semiconductor, DMM-TPA-Th2-MMN, with a planar fused triphenylamine (DMM-TPA) donor and a methylene malononitrile (MMN) acceptor was synthesized. The planar semiconductor exhibited better p-type semiconducting performance with a power conversion efficiency of 4.04% in solution-processed small-molecule organic solar cells than did the tilted TPA-Th2-MMN semiconductor, enhancing hole mobilities due to more favorable intermolecular π–π packing interactions.

In this study, we demonstrated the enhanced efficiency of dye-sensitized solar cells (DSSCs) using iodine vapor-doped nanostructured polyaniline (PANI)-based counter electrodes (CEs). The electrical conductivities of chemically synthesized PANI emeraldine salt (PANI-ES) and dedoped emeraldine base (PANI-EB) were increased from 3.1 S cm −1 to 9.3 S cm −1 and 2.0 × 10 −5 S cm −1 to 0.5 S cm −1 , and the doping levels of those were increased from 38.2% to 41.8% and 3.2% to 33.3%, respectively, via iodine vapor doping. Compared with PANI-ES and PANI-EB CEs, iodine-doped PANIs (PANI-ES-I 2 and PANI-EB-I 2 ) CEs with improved electrical properties were demonstrated higher electro-catalytic activity toward I − /I 3 − redox couples, due to better charge carrier transport and reduced charge transfer resistance. The cells based on the PANI-ES-I 2 and PANI-EB-I 2 CE exhibited higher photovoltaic parameters and efficiency. Moreover, we successfully increased the cell efficiency of the PANI-ES-I 2 CE-based DSSCs to a maximum efficiency of ~7.86%.

A novel and efficient symmetrical donor–acceptor–donor organic semiconductor, TFN-bis[ter-HT3-TPA], comprising two triphenylamine (TPA) donors and one fumaronitrile (FN) acceptor linked by π-conjugated hexylated quaterthiophene, was synthesized and its photovoltaic behavior in solution-processed small molecule organic solar cells (SMOSCs) was investigated. Under light illumination, the synthetic intermediate di-bithophenyl-fumaronitrile, containing the FN acceptor moiety, exhibited cis–trans isomerization in solution, while cis–trans photoisomerisation of TFN-bis[ter-HT3-TPA] was not observed, presumably because of the steric bulk of the TPA-hexylated terthiophene in the cis-isomer. The TFN-bis[ter-HT3-TPA] showed strong intramolecular charge transfer between the TPA donor and the FN acceptors. A TFN-bis[ter-HT3-TPA]:PC71BM bulk heterojunction film with an optimized weight ratio of 1:3 resulted in an improved photovoltaic performance and an enhanced hole mobility. After insertion of a TiOx layer between the photoactive layer and the Al electrode, a power conversion efficiency of 2.21% was obtained in devices fabricated from the TFN-bis[ter-HT3-TPA]:PC71BM film resulting in a ∼17% higher efficiency than devices without a TiOx layer.

In this study, 1-(2,6-diisopropylphenyl)-2,5-di(2-thienyl)pyrrole-based metal-free organic dyes containing three different non planar electron donor groups such as methoxy or hexyloxy substituted triphenylamine and difluorenephenylamine were prepared in order to see the effect of electron donor groups on the opto-electrical properties and applied in dye-sensitized solar cells (DSSC). All three dyes showed broad absorption band in visible part of the solar spectrum (∼300 nm–600 nm). The dye ( TPTDYE-3 ) containing sterically less hindered methoxy substituted triphenylamine was found to show relatively red shifted absorption compared to that of the dye ( TPTDYE-4 ) containing hexyloxy substituted triphenylamine or the dye ( TPTDYE-5 ) containing difluorenephenylamine. The optical band gaps of the three dyes were calculated to be 2.19 eV, 2.22 eV and 2.24 eV, respectively, and the highest occupied molecular orbital (HOMO) energy levels of the three dyes were found to be located at 0.65 V, 0.68 V and 0.75 V, respectively. The DSSC performance of each dye was investigated with and without coadsorbent. The maximum solar to electrical energy conversion efficiencies ( η ) of the DSSCs made from only sensitizer were 4.18%, 5.28% and 5.42% while those of the DSSCs made from sensitizer with coadsorbent were 5.47%, 5.58% and 5.63%, respectively.

Two new triphenylamine-based metal-free organic dyes ( TPTDYE-1 and TPTDYE-2 ) containing 1-(2,6-diisopropylphenyl)-2,5-di(2-thienyl)pyrrole as a new π-conjugated chromophore were synthesized for dye-sensitized solar cell (DSSC) applications. TPTDYE-1 containing three donor groups around the acceptor group was found to show relatively narrow absorption band from 300 nm to 470 nm while TPTDYE-2 having extended π–π delocalization between the donor and acceptor group showed broad absorption band from 300 nm to 550 nm. The electrochemical studies indicate that the HOMO–LUMO energy gap of TPTDYE-1 is considerably wider than that of TPTDYE-2 . The dye-sensitized solar cell performance of each dye was investigated, and the TPTDYE-2 -sensitized cell was found to show a maximum monochromatic incident photon-to-current conversion efficiency (IPCE) of 75%, a short-circuit photocurrent density ( J sc ) of 13.50 mA/cm 2 , an open-circuit voltage ( V oc ) of 0.72 V, and a fill factor (FF) of 0.69, corresponding to an overall conversion efficiency of 6.71% under simulated AM 1.5 irradiation (100 mW/cm 2 ). Under the same condition the TPTDYE-1 -sensitized cell showed the same IPCE value of 75% with a promising conversion efficiency of 6.00%, a J sc of 11.11 mA/cm 2 , a V oc of 0.76 V, and a FF of 0.71.

New efficient push-pull organic semiconductors comprising of on the N , N -(6-bis(9,9-dimethyl-9 H -fluoren-2-yl)amino-benzo[ b ]thiophen (bisDMFABT) donor and the various acceptors such as NO 2 , DCBP, and TCF, which were linked with thiophene or vinyl thiophene π-conjugation bridges, were synthesized, and their photovoltaic characteristics were investigated in solution processed small molecule organic solar cells (SMOSCs). The intramolecular charge transfers of these materials were effectively appeared in between bisDMFABT donor and acceptors, depending on the electron-withdrawing strength of acceptors. The organic semiconductor having DCBF acceptor exhibited the best power conversion efficiency of 3.22% with short circuit current of 9.64 mA/cm 2 , fill fator of 0.42, and open circuit voltage of 0.80 V in SMOSC devices with TiO x thin layer.

New unsymmetrical low band-gap push–pull squaraine chromophores, [TPA-bisHT-HP]-X-Ind [X: SQ, diCNSQ], which are composed of triphenylamine electron donating, π-conjugated dithiophene-pyrrole bridging, and squaraine-indol electron withdrawing moieties, for their application in solution processed BHJ solar cell. The [TPA-bisHT-HP]-diCNSQ-Ind having the stronger electron withdrawing moiety exhibits significantly the red-shifted absorption spectrum due to its strong intramolecular charge transfer in solution as well as in solid-state. The bulk-heterojunction photovoltaic devices fabricated with [TPA-bisHT-HP]-diCNSQ-Ind/C71-PCBM film exhibited a PCE of 2.05% (±0.07) with short-circuit current (Jsc)=9.05 mA/cm2, fill factor (FF)=0.33, and open-circuit voltage (Voc)=0.69 V, which is ∼3 times higher efficiency compared to [TPA-bisHT-HP]-SQ-Ind/C71-PCBM BHJ films.

Low photovoltage for metal-free organic dye-sensitized solar cells (DSSCs) has been restricting them surpassing the equivalent cells based on ruthenium complex sensitizers (typically N719). In this study, an alumina (Al 2 O 3 ) layer was employed to cover on the titania (TiO 2 ) surface before dye loading in order to improve the photovoltage of the organic dye based DSSCs. The open-circuit voltage ( V oc ) of the solar cell was found to increase by 0.02–0.06 V for a variety of organic sensitizers by the presence of the Al 2 O 3 overcoat, while the photocurrent ( J sc ) was observed highly dependent on the property of the sensitizer. Results show that for the sensitizers with a low Low-Unoccupied-Molecular-Orbital (LUMO) level or a large molecular size, the DSSC yielded a decreased J sc due to two factors, (i) an insufficient driving force for electron injection due to the upshift of the conduction band level of the TiO 2 /Al 2 O 3 electrode, and (ii) a decrease of dye adsorption amount for the TiO 2 /Al 2 O 3 electrode in comparison with the referenced TiO 2 electrode because of the reduced pore size and porosity by Al 2 O 3 coating. However, for the sensitizers with a high (more negative) LUMO level and a small molecular size, the J sc of the DSSCs based on the TiO 2 /Al 2 O 3 electrode was very close to that composed of only TiO 2 electrode. Using such organic dyes sensitizing on the TiO 2 /Al 2 O 3 electrode, over 8% in the efficiency of the DSSCs was facilely attained and particularly an efficiency of 8.72% was obtained for a cocktail solar cell with two organic dyes.

New symmetrical low band-gap small molecule materials, SQ-bis[HP-HT2-TPA] and SQ-bis[HP-HT2-BT] incorporating as novel derivative of squaraine-pyrrole framework and π-extended thiophene with triphenyamine (TPA) and benzothiophene (BT) end group, have been synthesized and characterized. The effects of TPA moiety were investigated. Compared to SQ-bis[HP-HT2-BT], SQ-bis[HP-HT2-TPA] exhibited three times improved transporting property of hole carrier and four times enhanced absorptivity by more efficient intermolecular π−π interaction for high-efficiency bulk heterojunction (BHJ) device, suggesting that TPA contributes to a better hole mobility. The bulk-heterojunction photovoltaic devices fabricated with SQ-bis[HP-HT2-TPA]/C71-PCBM BHJ film had an average power-conversion efficiency of 1.83%(±0.12) under 100 mW/cm2, with a short-circuit current (Jsc) of 9.32 mA/cm2, fill factor (FF) of 0.30, and open-circuit voltage (Voc) of 0.65 V, which has ∼42% higher efficiency compared to SQ-bis[HP-HT2-BT]/C71-PCBM BHJ films.

Three organic sensitizers incorporating thia-bridged heterohelicene unit, thiophene-conjugate bridge, and cyanoacrylic acid were synthesized. The power conversion efficiency was quite sensitive to the substituents on heterohelicene donor group. Under standard global AM 1.5 solar conditions, the JK-206-sensitized cell gave a short-circuit photocurrent density (Jsc) of 13.44 mA cm−2, an open-circuit voltage (Voc) of 0.71 V, and a fill factor of 0.74, corresponding to an overall conversion efficiency of 7.08%. The device based on the JK-206 with an ionic liquid electrolyte showed an excellent long-term stability. The initial efficiency of 5.6% for JK-206 slightly decreased to only 5.4% after the 1000 h light soaking at 60 °C.

This study aims to investigate a cost effective and efficient way of analyzing customer impressions on design alternatives by incorporating the benefits of virtual prototyping into the Internet-based experimental environment. It is hypothesized that the results of the Internet-based experiment using the images of virtual prototypes are comparable to those of the virtual reality-based environment using virtual prototypes. Two experiments were conducted. In the virtual reality environment, participants were employed to evaluate virtual prototypes while in the Internet environment participants evaluated images of the same virtual prototypes from their own places. For each experiment, 16 male participants were employed to evaluate 32 different virtual prototypes generated from the combination of 17 design elements of automobile interior. The results of the experiments indicated that there were no significant differences between the two experimental methods while the Internet environment-based method could save considerable time and efforts for experimentation. This study concludes that the Internet-based evaluation method using the images of virtual prototypes could be a cost effective and efficient way of analyzing customer impressions on design alternatives. Relevance to Industry This study showed that the results of the Internet-based evaluation method using the images of virtual prototypes are comparable to those of the virtual reality-based method using real virtual prototypes. The Internet-based evaluation method could be used as a cost effective and efficient way of collecting and analyzing various customers’ impressions on design alternatives at the early stage of product development process.

Five novel organic sensitizers that contain a fused-planar triphenylamine as electron donor have been synthesized and their photophysical properties, theoretical calculation and photovoltaic performances as well as stability test have been studied. Under standard AM 1.5 sunlight, the sensitizer JK-164 yielded a short-circuit photocurrent density of 15.32 mA cm −2 , an open-circuit voltage of 0.70 V, and a fill factor of 0.74, corresponding to an overall conversion efficiency of 7.86%. The JK-164 cell exhibits an excellent stability, revealing a slight change after 1000 h of light soaking at 60 °C using a solvent free ionic liquid. The cell shows a higher open-circuit voltage ( V oc ) compared to that of JK-163 due to an increased electron life time ( τ c ) in the conduction band of TiO 2 .

In tandem-structured dye-sensitized solar cell (DSSC) composed of two parallel-connected sub-cells, the photovoltage (Voc) generated by the back sub-cell is usually rather low, resulting in low Voc and conversion efficiency (η) of the tandem cell. To solve this issue, two simple but very efficient strategies, namely, the filling of Li+-absent electrolyte and/or coating Al2O3 on TiO2 electrode surface in the back sub-cell, were explored to enhance the Voc of the back sub-cell and hence that of the tandem cell. The former strategy was expected to heighten the energy level of TiO2 conduction band, and the latter one to retard the charge recombination. The photovoltaic performance measurements reveal that in the both cases, although there was a slight decrease in the photocurrent (Jsc), an obvious rise in the Voc was achieved for the tandem cells, leading to significant improvements in η of the tandem cells. Compared to the individual organic dye-sensitized solar cell (the highest η is 7.58%), the tandem cell with two organic dyes having complementary absorption spectra demonstrates an improved efficiency of up to 8.33% by a combinational application of Li+-absent electrolyte and Al2O3 overcoat. The results presented in this study highlight that the efficiency of a parallel-connected tandem-structured DSSC can be improved significantly through enhancing the photovoltage of the back sub-cell, which is first time reported.

In recent years, power consumption has become one of the most critical design concerns in designing VLSI systems. The reduction of power consumption is inevitably required by the emergence of highly efficient and fast systems, which include CPU (central processor unit), MCU (micro controller unit), cache, et cetera. This paper introduces a new low-power cache controller with successive tag comparison algorithm. Using these methods, the power consumption of a cache can be reduced. Simulation results show that the power consumption of a cache using the proposed method is reduced by 42% compared with conventional methods.