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A low-bandgap dimeric porphyrin molecule for 10% efficiency solar cells with small photon energy loss
Dimeric porphyrin molecules have great potential as donor materials for high performance bulk heterojunction organic solar cells (OSCs). Recently reported dimeric porphyrins bridged by ethynylenes showed power conversion efficiencies (PCEs) of more than 8%. In this study, we design and synthesize a new conjugated dimeric D-A porphyrin ZnP2BT-RH, in which the two porphyrin units are linked by an electron accepting benzothiadiazole (BT) unit. The introduction of the BT unit enhances the electron delocalization, resulting in a lower highest occupied molecular orbital (HOMO) energy level and an increased molar extinction coefficient in the near-infrared (NIR) region. The bulk heterojunction solar cells with ZnP2BT-RH as the donor material exhibit a high PCE of up to 10% with a low energy loss (Eloss) of only 0.56 eV. The 10% PCE is the highest for porphyrin-based OSCs with a conventional structure, and this Eloss is also the smallest among those reported for small molecule-based OSCs with a PCE higher than 10% to date
Cross-institution online problem based learning in Chinese Medicine Education
New education technology drives the pedagogical changes nowadays. Teaching and learning collaborations can now be extended beyond institutional boundaries. This study reports a new attempt of cross-institution collaboration in co-teaching a Chinese Medicine course. A Cross-institution Online Problem-based Learning (COPBL) is designed and implemented by the University of Hong Kong (HKU) and Chengdu University of Traditional Chinese Medicine (CDUTCM). There are 25 students from HKU and 24 students from CDUTCM who have participated in the COPBL. It is a supplementary component to courses and a seven-step approach has been adopted. Students work individually and collaboratively with floating-facilitators. The classes are blended with face-to-face and online components. As an initial step to understand the effectiveness of COPBL, this study specifically focuses on students’ use of the discussion forum, which is a key online component in COPBL. There are 91.8% of students who have viewed the discussion forum in total, 839 of view counts in all discussion forums. There are 63 replies recorded in all of the discussion forums. The replies could be identified into following categories, comments (33%), comments and questions (27%), responses (37%), and others (3%).This study has demonstrated that problem-based learning can be conducted in a blended form with traditional classroom teaching methods and well-designed online components. The COPBL offers new possibilities in redesigning pedagogy with new education technology. It could bring our education into a new era surrounded with new learning experiences.postprin
Dispersive charge density wave excitations and temperature dependent commensuration in Bi2Sr2CaCu2O8+{\delta}
Experimental evidence on high-Tc cuprates reveals ubiquitous charge density
wave (CDW) modulations, which coexist with superconductivity. Although the CDW
had been predicted by theory, important questions remain about the extent to
which the CDW influences lattice and charge degrees of freedom and its
characteristics as functions of doping and temperature. These questions are
intimately connected to the origin of the CDW and its relation to the
mysterious cuprate pseudogap. Here, we use ultrahigh resolution resonant
inelastic x-ray scattering (RIXS) to reveal new CDW character in underdoped
Bi2Sr2CaCu2O8+{\delta} (Bi2212). At low temperature, we observe dispersive
excitations from an incommensurate CDW that induces anomalously enhanced phonon
intensity, unseen using other techniques. Near the pseudogap temperature T*,
the CDW persists, but the associated excitations significantly weaken and the
CDW wavevector shifts, becoming nearly commensurate with a periodicity of four
lattice constants. The dispersive CDW excitations, phonon anomaly, and
temperature dependent commensuration provide a comprehensive momentum space
picture of complex CDW behavior and point to a closer relationship with the
pseudogap state
Purification and Characterization of Two New Allergens from the Venom of Vespa magnifica
Due to poor diagnostic facilities and a lack of medical alertness, allergy to Vespa wasps may be underestimated. Few allergens have been identified from Vespa wasps
Group Visits: Promoting Adherence to Diabetes Guidelines
BACKGROUND: Current diabetes management guidelines offer blueprints for providers, yet type 2 diabetes control is often poor in disadvantaged populations. The group visit is a new treatment modality originating in managed care for efficient service delivery to patients with chronic health problems. Group visits offer promise for delivering care to diabetic patients, as visits are lengthier and can be more frequent, more organized, and more educational. OBJECTIVE: To evaluate the effect of group visits on clinical outcomes, concordance with 10 American Diabetes Association (ADA) guidelines [American Diabetes Association, Diabetes Care, 28:S4–36, 2004] and 3 United States Preventive Services Task Force (USPSTF) cancer screens [U.S. Preventive Services Task Force, http://www.ahrq.gov/clinic/uspstf/resource.htm, 2003]. RESEARCH DESIGN AND METHODS: A 12-month randomized controlled trial of 186 diabetic patients comparing care in group visits with care in the traditional patient–physician dyad. Clinical outcomes (HbA1c, blood pressure [BP], lipid profiles) were assessed at 6 and 12 months and quality of care measures (adherence to 10 ADA guidelines and 3 USPSTF cancer screens) at 12 months. RESULTS: At both measurement points, HbA1c, BP, and lipid levels did not differ significantly for patients attending group visits versus those in usual care. At 12 months, however, patients receiving care in group visits exhibited greater concordance with ADA process-of-care indicators (p < .0001) and higher screening rates for cancers of the breast (80 vs. 68%, p = .006) and cervix (80 vs 68%, p = .019). CONCLUSIONS: Group visits can improve the quality of care for diabetic patients, but modifications to the content and style of group visits may be necessary to achieve improved clinical outcomes
Enhanced detection of early hepatocellular carcinoma by serum SELDI-TOF proteomic signature combined with alpha-fetoprotein marker.
BACKGROUND: Biomarkers for accurate diagnosis of early hepatocellular carcinoma (HCC) are limited in number and clinical validation. We applied SELDI-TOF-MS ProteinChip technology to identify serum profile for distinguishing HCC and liver cirrhosis (LC) and to compare the accuracy of SELDI-TOF-MS profile and alpha-fetoprotein (AFP) level in HCC diagnosis. PATIENTS AND METHODS: Serum samples were obtained from 120 HCC and 120 LC patients for biomarker discovery and validation studies. ProteinChip technology was employed for generating SELDI-TOF proteomic features and analyzing serum proteins/peptides. RESULTS: A diagnostic model was established by CART algorithm, which is based on 5 proteomic peaks with m/z values at 3324, 3994, 4665, 4795, and 5152. In the training set, the CART algorithm could differentiate HCC from LC subjects with a sensitivity and specificity of 98% and 95%, respectively. The results were assessed in blind validation using separate cohorts of 60 HCC and 60 LC patients, with an accuracy of 83% for HCC and 92% for LC patients. The diagnostic odd ratio (DOR) indicated that SELDI-TOF proteomic signature could achieve better diagnostic performance than serum AFP level at a cutoff of 20 ng/mL (AFP(20)) (92.72 vs 9.11), particularly superior for early-stage HCC (87% vs 54%). Importantly, a combined use of both tests could enhance the detection of HCC (sensitivity, 95%; specificity, 98%; DOR, 931). CONCLUSION: Serum SELDI-TOF proteomic signature, alone or in combination with AFP marker, promises to be a good tool for early diagnosis and/screening of HCC in at-risk population with liver cirrhosis
A New Stalked Filter-Feeder from the Middle Cambrian Burgess Shale, British Columbia, Canada
Burgess Shale-type deposits provide invaluable insights into the early evolution of body plans and the ecological structure of Cambrian communities, but a number of species, continue to defy phylogenetic interpretations. Here we extend this list to include a new soft-bodied animal, Siphusauctum gregarium n. gen. and n. sp., from the Tulip Beds (Campsite Cliff Shale Member, Burgess Shale Formation) of Mount Stephen (Yoho National Park, British Columbia). With 1,133 specimens collected, S. gregarium is clearly the most abundant animal from this locality
Lattice Boltzmann simulation of alumina-water nanofluid in a square cavity
A lattice Boltzmann model is developed by coupling the density (D2Q9) and the temperature distribution functions with 9-speed to simulate the convection heat transfer utilizing Al2O3-water nanofluids in a square cavity. This model is validated by comparing numerical simulation and experimental results over a wide range of Rayleigh numbers. Numerical results show a satisfactory agreement between them. The effects of Rayleigh number and nanoparticle volume fraction on natural convection heat transfer of nanofluid are investigated in this study. Numerical results indicate that the flow and heat transfer characteristics of Al2O3-water nanofluid in the square cavity are more sensitive to viscosity than to thermal conductivity
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