5,510 research outputs found
Polythiophenes comprising conjugated pendantstoward long-term air-stable inverted polymer solar cellswith high open circuit voltages
A series of polythiophenes (PTs) functionalized with bulky conjugated side chains comprising tert-butylsubstituted carbazole (tCz) as an electron donor pendant and bisbenzothiazolylvinyl (DBT) as anelectron acceptor pendant were synthesized via Stille copolymerization for polymer solar cell (PSC)applications. We use the descriptors PTtCz, PT(tCz)0.9(DBT)0.1, PT(tCz)0.64(DBT)0.36, PT(tCz)0.45(DBT)0.55,and PTDBT to identify each of these conjugated polymers, with the names denoting the compositionsof the bulky pendants. The tunable energy levels of the PTs were accomplished by incorporating bothtCz as a donor pendant and DBT as an acceptor pendant, while retaining the low-lying HOMO levels( 5.26 to 5.39 eV). Furthermore, lower bandgaps were observed for the DBT-derived PTs because ofstronger donor–p–acceptor characteristics and more efficient intramolecular charge transfer.Conventional PSCs were fabricated by spin-coating the blend of each PT and the fullerene derivative(PC71BM). The conventional PSC devices exhibited high open circuit voltages (Voc) of around 0.79–0.91 V. The power conversion efficiency (PCE) of the PSCs based on PTtCz : PC71BM (w/w ¼ 1 : 2.5)reached 2.48% with a Voc of 0.91 V, short circuit current (Jsc) of 6.58 (mA cm 2) and fill factor (FF) of41% under the illumination of AM1.5, 100 mW cm 2. Furthermore, a PTtCz/PC71BM-based inverted PSCwith ZnOx and MoO3 as an electron extraction layer and a hole extraction layer respectively was capableof retaining ca. 80% of its original efficiency after storage under ambient conditions (withoutencapsulation) for 1032 h, according to the ISOS-D-1 shelf protocol. The highly durable inverted PSCaccompanied by a large Voc value was achieved for the PT-type polymers
High-Frequency Ultrasound Imaging to Evaluate Liver Fibrosis Progression in Rats and Yi Guan Jian Herbal Therapeutic Effects
The animals used in liver fibrosis studies must usually be sacrificed. Ultrasound has been demonstrated to have the ability to diagnose hepatic fibrosis and cirrhosis in experimental small-animal models. However, few studies have used high-frequency ultrasound (HFU, 40 MHz) to monitor changes in the rat liver and other hollow organs longitudinally. In this study, liver fibrosis was induced by administering dimethylnitrosamine (DMN) in SD rats, aged 8 weeks, for three consecutive days per week for up to 4 weeks. A Chinese herbal medicine Yi Guan Jian (YGJ) was orally administered (1.8 g/kg daily) to DMN-induced liver fibrosis rats for 2 weeks. Compared with the normal control rats, rats treated with DMN for either 2 weeks or 4 weeks had significantly lower body weights, liver indexes and elevation of hydroxyproline, GOT, and GPT contents. YGJ herbal treatment remarkably prevented rats from DMN-induced liver fibrosis. The HFU scoring results among the normal controls, 2-week DMN-treated rats, 4-week DMN-treated rats, and combined 2-week YGJ therapy with 4-week DMN-treated rats also reached statistical significance. Thus, HFU is an accurate tool for the longitudinal analysis of liver fibrosis progression in small-animal models, and the YGJ may be useful in reversing the development of hepatic fibrosis
Noninvasive Wireless Sensor PFMT Device for Pelvic Floor Muscle Training
[[abstract]]Urinary incontinence is a common problem among adults. Studies have shown up to 70% improvement in stress incontinence symptoms following appropriately performed pelvic floor exercise. This improvement is evident across all age groups. In this study, we cooperated with a doctor of the Department of Obstetrics and Gynecology, Taipei Veterans General Hospital, Taiwan. We developed a noninvasive device with the purpose of helping patients commence and perform pelvic floor muscle training (PFMT). This device consists of a PFMT device, an Arduino control board, a force sensor, a Bluetooth device, and an SD card. The objectives of this study are to train patients to inhibit detrusor contraction voluntarily and to contract periurethral muscles selectively. The system records and analyzes sensor data and provides voice prompts during PFMT exercise for patients at hospitals or their homes. Meanwhile, it tracks patients’ PFMT exercise at home, and doctors can contact patients for additional visitation(s) if necessary.[[incitationindex]]SCI[[booktype]]紙
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