Sputtered highly ordered TiO2 nanorod arrays and their applications as the electrode in dye-sensitized solar cells

For the first time, the TiO2 nanorod arrays have been prepared on ITO substrates at room temperature by dc reactive magnetron sputtering technique. These TiO2 nanorods have a preferred orientation along the (220) direction and are perpendicular to the ITO substrate. Both the X-ray diffraction and Raman scattering measurements show that the highly ordered TiO2 nanorod arrays have an anatase crystal structure. The diameter of the nanorod varies from 30 nm to 100 nm and the nanorod length can be varied from several hundred nanometers to several micrometers depending on the deposition time. The TiO2 nanorod arrays with about 3 micrometers length have been used as an electrode for dye-sensitized solar cell (DSSC). Short-circuit photocurrent density, open-circuit voltage, fill factor and light-to-electricity conversion efficiency at 100 mW/cm2 light intensity are estimated to be 12.76 mA/cm2, 0.65 V, 0.63 and 5.25%, respectively, for the DSSC made of the TiO2 nanorods.SFRH/BSAB/862/2008, FC

Investigation and analysis of psychological stress and professional identity of nursing students during COVID-19 pandemic

426-432Certain diseases or infections affect large number of people in short span of time. A local endemic disease can outbreak into an epidemic affecting the whole population or region which at times extend to other countries and continents and become pandemic. Pandemics results in loss of life as well as economy. Pooled efforts and resources, effective sharing of data, parallel multiple approaches as well as physical and mental state of front line staff influence management of pandemics. The coronavirus disease COVID-19 caused by SARS-CoV-2 started in December 2019 from Wuhan in China, is now a worldwide public health emergency affecting millions of people. It affects many frontline healthcare workers too. Here, we studied psychological stress and professional identity of nursing students for possible correlations, if any, and analyze influencing factors. We used purposive sampling technique with 415 nursing students in Nanjing, China through a general information questionnaire, perceived stress scale and nursing professional identity questionnaire. Students' origin, monthly living expenses and their knowledge on epidemic prevention and treatment have shown a significant impact on their psychological stress (P <0.01). Similarly, students' gender, origin, clinical practices and knowledge of prevention and treatment, and whether they actively learn such knowledge impact significantly on their professional identity (P <0.01). The overall score of psychological stress was (24.47±7.35) and professional identity had 72.47±8.07. The stress condition exhibited negative correlation with the degree of professional identity (P <0.01，r = -0.457). Increased psychological stress, had lower sense of professional identity. Overall, analysis of data on perceived stress and professional identity pandemic suggests that stress levels are inversely proportional to knowledge in effective ways of handling the pandemic. Students with clinical practice fared better in terms of professional identity. The study suggests nursing students to stay focused on studies, clinical practice and counselling, if required

Nadir CA-125 level as prognosis indicator of high-grade serous ovarian cancer

PURPOSE: The capacity of nadir CA-125 levels to predict the prognosis of epithelial ovarian cancer remains controversial. This study aimed to explore whether the nadir CA-125 serum levels could predict the durations of overall survival (OS) and progression free survival (PFS) in patients with high-grade serous ovarian cancer (HG-SOC) from the USA and PRC. MATERIALS AND METHODS: A total of 616 HG-SOC patients from the MD Anderson Cancer Center (MDACC, USA) between 1990 and 2011 were retrospectively analyzed. The results of 262 cases from the Jiangsu Institute of Cancer Research (JICR, PRC) between 1992 and 2011 were used to validate the MDACC data. The CA-125 immunohistochemistry assay was performed on 280 tissue specimens. The Cox proportional hazards model and the log-rank test were used to assess the associations between the clinicopathological characteristics and duration of survival. RESULTS: The nadir CA-125 level was an independent predictor of OS and PFS (p < 0.01 for both) in the MDACC patients. Lower nadir CA-125 levels (≤10 U/mL) were associated with longer OS and PFS (median: 61.2 and 16.8 months with 95% CI: 52.0–72.4 and 14.0–19.6 months, respectively) than their counterparts with shorter OS and PFS (median: 49.2 and 10.5 months with 95% CI: 41.7–56.7 and 6.9–14.1 months, respectively). The nadir CA-125 levels in JICR patients were similarly independent when predicting the OS and PFS (p < 0.01 for both). Nadir CA-125 levels less than or equal to 10 U/mL were associated with longer OS and PFS (median: 59.9 and 15.5 months with 95% CI: 49.7–70.1 and 10.6–20.4 months, respectively), as compared with those more than 10 U/mL (median: 42.0 and 9.0 months with 95% CI: 34.4–49.7 and 6.6–11.2 months, respectively). Baseline serum CA-125 levels, but not the CA-125 expression in tissues, were associated with the OS and PFS of HG-SOC patients in the MDACC and JICR groups. However, these values were not independent. Nadir CA-125 levels were not associated with the tumor burden based on second-look surgery (p = 0.09). Patients who achieved a pathologic complete response had longer OS and PFS (median: 73.7 and 20.7 months with 95% CI: 63.7–83.7 and 9.5–31.9 months, respectively) than those with residual tumors (median: 34.6 and 10.6 months with 95% CI: 6.9–62.3 and 4.9–16.3 months, respectively). CONCLUSIONS: The nadir CA-125 level was an independent predictor of OS and PFS in HG-SOC patients. Further prospective studies are required to clinically optimize the chances for a complete clinical response of HG-SOC cases with higher CA-125 levels (>10 U/mL) at the end of primary treatment

Effects of Polystyrene Microplastics on Growth and Toxin Production of Alexandrium pacificum

Microplastics (MP) widely distributed in aquatic environments have adverse effects on aquatic organisms. Currently, the impact of MP on toxigenic red tide microalgae is poorly understood. In this study, the strain of Alexandrium pacificum ATHK, typically producing paralytic shellfish toxins (PST), was selected as the target. Effects of 1 and 0.1 μm polystyrene MP with three concentration gradients (5 mg L−1, 25 mg L−1 and 100 mg L−1) on the growth, chlorophyll a (Chl a), photosynthetic activity (Fv/Fm) and PST production of ATHK were explored. Results showed that the high concentration (100 mg L−1) of 1 μm and 0.1 μm MP significantly inhibited the growth of ATHK, and the inhibition depended on the size and concentration of MP. Contents of Chl a showed an increase with various degrees after MP exposure in all cases. The photosynthesis indicator Fv/Fm of ATHK was significantly inhibited in the first 11 days, then gradually returned to the level of control group at day 13, and finally was gradually inhibited in the 1 μm MP treatments, and promotion or inhibition to some degree also occurred at different periods after exposure to 0.1 μm MP. Overall, both particle sizes of MP at 5 and 25 mg L−1 had no significant effect on cell toxin quota, and the high concentration 100 mg L−1 significantly promoted the PST biosynthesis on the day 7, 11 and 15. No significant difference occurred in the cell toxin quota and the total toxin content in all treatments at the end of the experiment (day 21). All MP treatments did not change the toxin profiles of ATHK, nor did the relative molar percentage of main PST components. The growth of ATHK, Chl a content, Fv/Fm and toxin production were not affected by MP shading. This is the first report on the effects of MP on the PST-producing microalgae, which will improve the understanding of the adverse impact of MP on the growth and toxin production of A. pacificum

Downcore variations of carbon reservoir ages linked to lake level changes in northwest China

Lacustrine sediments provide an excellent opportunity to study climate change beyond the instrumental period and further to elucidate its intrinsic interactions with ecosystem. However, the radiocarbon (C-14)-based chronological framework of such natural archives, on which robust interpretation of geochemical proxies primarily depends, is commonly challenged due to the difficulty in properly correcting carbon reservoir effect. Here we combine new and existing C-14 dates on total organic carbon (TOC) in two sediment cores from Lake Qinghai and Manas, northwest China, to evaluate the reservoir effect (expressed by reservoir age, RA) over the past similar to 1500 years. Generally, these two cores characterize RA values ranging from similar to 2100 to 4200 and from similar to 350 to 2100 years respectively. Straightforward comparison with paleorecords generated from the same cores indicates a close correlation between RA changes and lake level fluctuations on multi-centennial timescales. Our results suggest that lake level changes (or hydrological variations), which are expected to control the relative input of terrigenous old carbon, merit careful consideration to reduce dating uncertainty. It is essential to select TOC samples across discrete depths, under the control of similar lake status, to allow comparable RAs and, as a result, to establish reliable chronology

Water depth control on n-alkane distribution and organic carbon isotope in mid-latitude Asian lakes

The relative proportion of mid-chain to long chain n-alkane homologues and isotopic compositions of total organic carbon (P-aq and delta C-13(org)) have been proposed as potential lake-level proxies since such features mainly come from submerged aquatic plants living within an optimum range of lake water depth. With limited dataset available, the applicability of both indices and their sensitivity to lake water depth changes across a broad geographic extent need further investigation. Here we report P-aq and delta C-13(org) values in surface sediments collected from 55 lakes in mid-latitude Asia. We have found an arched relationship between P-aq index and water depth, with high Paq values occurring at the depth of similar to 1-10 m, while sediments from shallower and deeper water lakes have relatively low P-aq values. delta C-13(org) variation resembles an arched pattern with depth in freshwater and brackish lakes, with relatively high delta C-13(org) values also corresponding to the depth of similar to 1-10 m, but substantially high delta C-13(org) values in hypersaline environments (salinity > similar to 100,000 mg/L) obscure the arched delta C-13(org)-depth relationship. We suggest that both indices respond to the structure of aquatic plant community, especially the biomass of submerged plants. Our results confirm that P-aq and delta C-13(org) can be used to infer lake-level changes in mid-latitude Asia, but other influencing factors have to be considered before applying the two proxies to downcore reconstructions, and combined utilization of the P-aq and delta C-13(org) indicators could improve the reliability of paleohydrological reconstructions

Appraisal of alkenone- and archaeal ether-based salinity indicators in mid-latitude Asian lakes

Lake water salinity, an important indicator of lake hydrological conditions, is critical to deciphering terrestrial paleoclimatic and paleoenvironmental changes. The proportion of C-37:4 alkenone to total C-37 alkenones (%C-37:4) and the relative abundance of archaeol to caldarchaeol (ACE) are promising salinity indices in lacustrine settings. Developing regional calibrations for both indicators is challenging due to limited datasets and a poor understanding of the factors that influence them. Here we present %C-37:4 and ACE data collected from 55 lakes in mid-latitude Asia with a wide salinity range, to evaluate how well the two proxies can be correlated with salinity and to infer potential influencing factors. The %C-37:4 values only show a weak negative correlation with salinity from all investigated lakes. The occurrence of C-37:3 alkenone isomer and abnormal values in the alkenone C37/C38 ratio might signal species shifts or environmental factors that compromise the %C-37:4-salinity relationship in our data set. Seasonal bias in alkenone production could further obscure this %C-37:4-salinity relationship. A stronger relationship emerges after removing samples influenced by these factors: %C-37:4 = -8.56 * log(10) (salinity) + 80.6, r(2) = 0.62, n = 37; or %C-37:4 = -13.46 * log(10) (salinity) + 101.48, with uncertainty in both variables considered. The ACE values show a strong positive correlation with salinity from all investigated lakes: ACE = 2.27 * 10(-4)* salinity + 25.4, r(2) = 0.75, n = 68; or ACE = 1.86 * 10(-4)* salinity + 38.1, with uncertainty in both variables considered. However, substantial deviations of the ACE values in low salinity range (&lt;60,000 mg/L) and majority of the ACE shift in the range of 60,000-100,000 mg/L suggest that the ACE primarily responds to Euryarchaeota/Archaea community changes when a salinity threshold is crossed. Accordingly, both lake salinity indicators have the potential to reconstruct past salinity changes when their influencing factors could be constrained, and the two independent proxies, when they are used together, could further refine salinity reconstructions. (C) 2020 Elsevier B.V. All rights reserved.</p

Systemic arterial blood pressure and intracerebral hemorrhage after mechanical thrombectomy in anterior cerebral circulation

The relationship between systemic arterial blood pressure (BP) and intracerebral hemorrhage (ICH) after mechanical thrombectomy (MT) of the cerebral artery remains unclear. This study aimed to determine the effect of BP variables on ICH after MT in patients with acute occlusions of the anterior cerebral circulation. Patients undergoing MT due to acute occlusions of the anterior cerebral circulation were enrolled in this single-center study. Non-invasive BP data following MT were obtained within the first 24 hours, including mean, maximum, minimum, difference between maximum and minimum, SD and coefficient of variation for systolic BP (SBP) and diastolic BP (DBP) and mean arterial pressure. ICH was defined and classified according to the European Cooperative Acute Stroke Study-II. In 164 enrolled patients (median age 65 (IQR 56-75) years; 31.7% female), higher maximum (89.5 mm Hg vs 98.5 mm Hg, p=0.001) and SD (9.8 mm Hg vs 10.9 mm Hg, p=0.038) of DBP were associated with higher risk of ICH. The optimal cut-off values associated with ICH for maximum SBP were 155 mm Hg and for maximum DBP 92.5 mm Hg, respectively. Higher BP within 24 hours after MT in acute occlusions of the anterior cerebral circulation is associated with a greater risk of ICH. More studies are needed to further determine optimal BP goals in the acute phase after MT

Salinity-controlled isomerization of lacustrine brGDGTs impacts the associated MBT5ME terrestrial temperature index

Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are microbial molecular fossils ubiquitous in natural environments. The correlation between the Methylation Index of brGDGTs (the MBT5ME paleothermometer) and temperature offers an important tool for reconstructing past terrestrial temperatures. However, factors other than temperature could also affect the distribution of brGDGTs in lacustrine systems, hampering the quantitative application of this paleothermometer. Here we investigated brGDGT distributions in contemporary sediments collected from 52 lakes in mid-latitude Asia. Combined with published brGDGT data from other lakes across the globe, we have found a strong salinity control on the relative abundance of 5-methyl brGDGTs versus their late-eluting isomers (including 6-methyl, 7-methyl, and unknown isomers). This allows the development of novel indices based on the isomerization of brGDGTs for tracing past lake water salinity. We also demonstrate , that salinity-controlled isomerization of pentamethylated and hexamethylated brGDGTs can significantly impact the MBT5ME paleothermometer, , potentially leading to an overestimation of past temperature, but the temperature signal can be extracted out of the MBT5ME index after correcting the salinity effect. As demonstrated in application to a Lake Qinghai (China) sediment core spanning the last 18 kyr, our finding could facilitate the simultaneous retrieval of reliable temperature and salinity records using brGDGTs in lacustrine settings, in particular for lakes that have experienced large salinity changes during the geological past. (C) 2021 Elsevier Ltd. All rights reserved