Effect of venting range hood flow rate on size-resolved ultrafine particle concentrations from gas stove cooking

Cooking is the main source of ultrafine particles (UFP) in homes. This study investigated the effect of venting range hood flow rate on size-resolved UFP concentrations from gas stove cooking. The same cooking protocol was conducted 60 times using three venting range hoods operated at six flow rates in twin research houses. Size-resolved particle (10–420 nm) concentrations were monitored using a NanoScan scanning mobility particle sizer (SMPS) from 15 min before cooking to 3 h after the cooking had stopped. Cooking increased the background total UFP number concentrations to 1.3 × 103 particles/cm3 on average, with a mean exposure-relevant source strength of 1.8 × 1012 particles/min. Total particle peak reductions ranged from 25% at the lowest fan flow rate of 36 L/s to 98% at the highest rate of 146 L/s. During the operation of a venting range hood, particle removal by deposition was less significant compared to the increasing air exchange rate driven by exhaust ventilation. Exposure to total particles due to cooking varied from 0.9 to 5.8 × 104 particles/cm3·h, 3 h after cooking ended. Compared to the 36 L/s range hood, higher flow rates of 120 and 146 L/s reduced the first-hour post-cooking exposure by 76% and 85%, respectively. © 2018 Crown Copyright. Published with license by Taylor & Francis Group, LLC

Mitochondria directly influence fertilisation outcome in the pig

The mitochondrion is explicitly involved in cytoplasmic regulation and is the cell's major generator of ATP. Our aim was to determine whether mitochondria alone could influence fertilisation outcome. In vitro, oocyte competence can be assessed through the presence of glucose-6-phosphate dehydrogenase (G6PD) as indicated by the dye, brilliant cresyl blue (BCB). Using porcine in vitro fertilisation (IVF), we have assessed oocyte maturation, cytoplasmic volume, fertilisation outcome, mitochondrial number as determined by mtDNA copy number, and whether mitochondria are uniformly distributed between blastomeres of each embryo. After staining with BCB, we observed a significant difference in cytoplasmic volume between BCB positive (BCB+) and BCB negative (BCB-) oocytes. There was also a significant difference in mtDNA copy number between fertilised and unfertilised oocytes and unequal mitochondrial segregation between blastomeres during early cleavage stages. Furthermore, we have supplemented BCB- oocytes with mitochondria from maternal relatives and observed a significant difference in fertilisation outcomes following both IVF and intracytoplasmic sperm injection (ICSI) between supplemented, sham-injected and non-treated BCB- oocytes. We have therefore demonstrated a relationship between oocyte maturity, cytoplasmic volume, and fertilisation outcome and mitochondrial content. These data suggest that mitochondrial number is important for fertilisation outcome and embryonic development. Furthermore, a mitochondrial pre-fertilisation threshold may ensure that, as mitochondria are diluted out during post-fertilisation cleavage, there are sufficient copies of mtDNA per blastomere to allow transmission of mtDNA to each cell of the post-implantation embryo after the initiation of mtDNA replication during the early postimplantation stages

Clinicopathological and prognostic implications of endoglin (CD105) expression in hepatocellular carcinoma and its adjacent non-tumorous liver

Aim: The expression pattern of endoglin (CD105) in hepatocellular carcinoma (HCC) has not been reported so far. We hypothesized that CD105 could differentially highlight a subset of microvessels in HCC, and intratumoral microvessel density (IMVD) by CD105 immunostaining (IMVD-CD105) could provide better prognostic information than IMVD by CD34 immunostaining (IMVD-CD34). Methods: Paraffin blocks of tumor and adjacent non-tumorous liver tissues from 86 patients who underwent curative resection of HCC were used for this study. Serial sections were stained for CD105 and CD34, respectively, to highlight the microvessels. IMVD was counted according to a standard protocol. Results: In the HCC tissues, CD105 was either negatively or positively stained only in a subset of microvessels. In contrast, CD34 showed positive and more extensive microvessel staining in all cases examined. However, in the adjacent non-tumorous liver sections, CD105 showed a diffuse pattern of microvessel staining in 20 of 86 cases, while CD34 showed negative or only focal staining of the sinusoids around portal area. Correlation with clinicopathological data demonstrated that lower scores of IMVD-CD105 were found in larger sized tumors [mean 41.4/0.74 mm 2 (>5 cm tumor) vs 65.9/0.74 mm 2 (≤5 cm tumor), P = 0.043] and more aggressive tumors, as indicated by venous infiltration [36.8/0.74 mm 2 (present) vs 64.2/0.74 mm 2 (absent), P = 0.020], microsatellite nodules [35.1/0.74 mm 2 (present) vs 65.9/0.74 mm 2 (absent), P = 0.012], and advanced TNM tumor stage [38.8/0.74 mm 2 (stage 3 or 4) vs 68.3/0.74 mm 2 (stage 1 or 2), P = 0.014]. No prognostic significance was observed when median values were used as cut-off points using either IMVD-CD105 or IMVD-CD34. However, the presence of the diffuse pattern of CD105 expression in the adjacent non-tumorous liver tissues predicted a poorer disease-free survival (median 8.6 vs 21.5 mo, P = 0.026). Conclusion: Our data demonstrate that a lower IMVD-CD105 is associated with larger and more aggressive tumors. In this study, IMVD-CD105 did not provide significant prognostic information. However, active angiogenesis as highlighted by diffuse CD105 staining of the microvessels in the adjacent non-tumorous liver tissues is predictive of early recurrence. © 2005 The WJG Press and Elsevier Inc. All rights reserved.published_or_final_versio

Anti-arrhythmic effects of hypercalcemia in hyperkalemic, Langendorff-perfused mouse hearts

published_or_final_versio

Testing the decoy effect to improve online survey participation: Evidence from a field experiment

As low participation and retention in online survey participation decrease confidence in its results, traditional research has focused on ways to optimize the survey structure and design. So far, no study has tested the decoy effect (i.e. offering an inferior decoy option to increase the attractiveness of the target option) to increase survey participation. In a field experiment with 203 students, we tested the effectiveness of adding a decoy questionnaire to the choice set to improve online survey participation. The decoy questionnaire featured open-ended instead of close-ended questions and delayed remuneration (1 week vs. 4 weeks). We found that the presence of the decoy questionnaire increased the probability of the target questionnaire being completed from 32.7 % to 55.9 %. Furthermore, while the decoy did not affect response behavior or cause non-response bias, a significant order effect was observed. When the target questionnaire was presented before the decoy, the participation was 82.7 % in comparison to 28.0 % when the decoy was presented first. This study is the first to test the decoy effect in the context of aiming to improve survey participation. These findings offer a ‘proof of principle’ that decoys have the potential to increase participation without negatively influencing question response behavior

Irradiation-induced molecular dipole reorientation in inverted polymer solar cell using small molecular electron collection layer

Inverted polymer solar cell is developed using small molecular tris(8-hydroxyquinolinato) aluminum (Alq3) as an electron collection layer between the active layer and indium-tin-oxide bottom cathode. Upon post-processing light irradiation by simulated solar illumination, the open-circuit voltage of the inverted device increases from 0.52 V to 0.60 V, resulting in the enhancement of the power conversion efficiency from 2.54 to 3.33 with negligible change in the short-circuit current. The performance improvement is attributed to the removal of surface potential due to irradiation-induced molecular dipole reorientation in the Alq3 layer, which reduces the charge transport barrier and improves the charge collection efficiency. © 2011 American Institute of Physics

Universal nonlinear infection kernel from heterogeneous exposure on higher-order networks

The colocation of individuals in different environments is an important prerequisite for exposure to infectious diseases on a social network. Standard epidemic models fail to capture the potential complexity of this scenario by (1) neglecting the higher-order structure of contacts which typically occur through environments like workplaces, restaurants, and households; and by (2) assuming a linear relationship between the exposure to infected contacts and the risk of infection. Here, we leverage a hypergraph model to embrace the heterogeneity of environments and the heterogeneity of individual participation in these environments. We find that combining heterogeneous exposure with the concept of minimal infective dose induces a universal nonlinear relationship between infected contacts and infection risk. Under nonlinear infection kernels, conventional epidemic wisdom breaks down with the emergence of discontinuous transitions, super-exponential spread, and hysteresis

Fabrication and characterization of Ni/P(VDF-TrFE) nanoscaled coaxial cables

Author name used in this publication: Kwo Ho LamAuthor name used in this publication: Cheng-Liang SunAuthor name used in this publication: Helen Lai Wa Chan2006-2007 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Electron impact excitations of S2 molecules

Low-energy electron impact excitations of S_2 molecules are studied using the fixed-bond R-matrix method based on state-averaged complete active space SCF orbitals. Integral cross sections are calculated for elastic electron collision as well as impact excitation of the 7 lowest excited electronic states. Also, differential cross sections are obtained for elastic collision and excitation of the a^1 Delta_g, b^1 Sigma_g^+ and B^3 Sigma_u^- states. The integrated cross section of optically allowed excitation of the B^3 Sigma_u^- state agrees reasonably well with the available theoretical result.Comment: 12 pages, 3 figures. Chemical Physics Letters, in pres