Limits on the use of cobalt sulfide as anode of p-type dye-sensitized solar cells

Thin films of cobalt sulfide (CoS) of thickness l < 10m have been employed as anodes of p-type dye-sensitized solar cells (p-DSCs) when P1-sensitized nickel oxide (NiO) was the photoactive cathode and /I - constituted the redox mediator. In the role of counter electrode for p-DSCs, CoS was preferred over traditional platinized fluorine-doped indium oxide (Pt-FTO) due to the lower cost of the starting materials (Co salts) and the easier procedure of deposition onto large area substrates. The latter process was carried out via direct precipitation of CoS from aqueous solutions. The photoconversion efficiency (η) of the corresponding device was 0.07%. This value is about 35% less than the efficiency that is obtained with the analogous p-DSC employing the Pt-FTO anode (η = 0.11). Unlike p-DSCs based on Pt-FTO anodes, the photoelectrochemical cells employing CoS electrodes showed that this anodic material was not able to sustain the photocurrent densities generated by P1-sensitized NiO at a given photopotential. Illumination of the p-DSCs with CoS anodes and P1-sensitized NiO cathodes actually induced the reverse bias of the photoelectrochemical cell with CoS behaving like a p-type semiconductor with no degeneracy. © 2017 IOP Publishing Ltd

Rashba spin-orbit coupling and spin relaxation in silicon quantum wells

Silicon is a leading candidate material for spin-based devices, and two-dimensional electron gases (2DEGs) formed in silicon heterostructures have been proposed for both spin transport and quantum dot quantum computing applications. The key parameter for these applications is the spin relaxation time. Here we apply the theory of D'yakonov and Perel' (DP) to calculate the electron spin resonance linewidth of a silicon 2DEG due to structural inversion asymmetry for arbitrary static magnetic field direction at low temperatures. We estimate the Rashba spin-orbit coupling coefficient in silicon quantum wells and find the $T_{1}$ and $T_{2}$ times of the spins from this mechanism as a function of momentum scattering time, magnetic field, and device-specific parameters. We obtain agreement with existing data for the angular dependence of the relaxation times and show that the magnitudes are consistent with the DP mechanism. We suggest how to increase the relaxation times by appropriate device design.Comment: Extended derivations and info, fixed typos and refs, updated figs and data. Worth a re-downloa

Modest effect of p53, EGFR and HER-2/neu on prognosis in epithelial ovarian cancer: a meta-analysis

Background: P53, egfr and her-2/neu are the most frequently studied molecular biological parameters in epithelial ovarian cancer, but their prognostic impact is still unequivocal. We performed a meta-analysis to more precisely estimate their prognostic significance. Methods: Published studies that investigated the association between p53, egfr and her-2/neu status and survival were identified. Meta-analysis was performed using a dersimonian-laird model. Publication bias was investigated using funnel plots and sources of heterogeneity were identified using meta-regression analysis. Results: A total of 62 studies were included for p53, 15 for egfr and 20 for her-2/neu. P53, egfr and her-2/neu status had a modest effect on overall survival (Pooled hr 1.47, 95% Ci 1.33-1.61 For p53; Hr 1.65, 95% Ci 1.25-2.19 For egfr and hr 1.67, 95% Ci 1.34-2.08 For her-2/neu). Meta-regression analysis for p53 showed that figo stage distribution influenced study outcome. For egfr and her-2/neu, considerable publication bias was present. Conclusions: Although p53, egfr and her-2/neu status modestly influences survival, these markers are, by themselves, unlikely to be useful as prognostic markers in clinical practice. Our study highlights the need for well-defined, prospective clinical trials and more complete reporting of results of prognostic factor studies. British journal of cancer ( 2009) 101, 149-159. Doi: 10.1038/Sj.Bjc.6605112 Www.Bjcancer.Com published online 9 june 2009 (C) 2009 Cancer research uk

Multidisciplinary decision-making in older patients with cancer, does it differ from younger patients?

Background: In order to tailor treatment to the individual patient, it is important to take the patients context and preferences into account, especially for older patients. We assessed the quality of information used in the decision-making process in different oncological MDTs and compared this for older (>70 years) and younger patients. Patients and methods: Cross-sectional observations of oncological MDTs were performed, using an observation tool in a University Hospital. Primary outcome measures were quality of input of information into the discussion for older and younger patients. Secondary outcomes were the contribution of different team members, discussion time for each case and whether or not a treatment decision was formulated. Results: Five-hundred and three cases were observed. The median patient age was 63 year, 32% were >70. In both age groups quality of patient-centered information (psychosocial information and patient's view) was poor. There was no difference in quality of information between older and younger patients, only for comorbidities the quality of information for older patients was better. There was no significant difference in the contributions by team members, discussion time (median 3.54 min) or number of decision reached (87.5%). Conclusion: For both age groups, we observed a lack of patient-centered information. The only difference between the age groups was for information on comorbidities. There were also no differences in contributions by different team members, case discussion time or number of decisions. Decision-making in the observed oncological MDTs was mostly based on medical technical information. (c) 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)

Outcomes of surgical treatment of non-metastatic gastric cancer in patients aged 70 and older:A systematic review and meta-analysis

The optimal surgical treatment strategy for gastric cancer in older patients needs to be carefully evaluated due to increased vulnerability of older patients. We performed a database search for randomized controlled trials (RCTs) and cohort studies that included patients ≥70 years with potentially resectable stage I-III gastric cancer. Postoperative and survival outcomes were compared between groups undergoing 1) gastrectomy vs conservative treatment (best supportive care or non-operative treatment), 2) minimally invasive (MIG) vs open gastrectomy (OG), or 3) extended vs limited lymphadenectomy. When possible, results were pooled using risk ratios (RR). Thirty-one studies were included. Six retrospective studies compared overall survival (OS) between gastrectomy (N = 2332) and conservative treatment (N = 246). Longer OS was reported in the gastrectomy group in all studies, but study quality was low and meta-analysis was not feasible. Eighteen cohort studies compared MIG (N = 3626) and OG (N = 5193). MIG was associated with fewer complications (pooled RR 0.68, 95% confidence interval 0.54–0.84). OS was not different between the groups. Two RCTs and five cohort studies compared outcomes between extended (N = 709) and limited lymphadenectomy (N = 1323). Complication rates were comparable between the groups. Two cohort studies found longer OS or cancer-specific survival after extended lymphadenectomy. No quality of life (QoL) or functional outcomes were reported. In older patients with gastric cancer, there is low-quality evidence for better OS after gastrectomy vs conservative treatment. Compared to OG, MIG was associated with less postoperative morbidity. The evidence to support extended lymphadenectomy is limited. QoL and functional outcomes should be addressed in future studies

SnO2 extended gate field-effect transistor as pH sensor

Extended gate field-effect transistor (EGFET) is a device composed of a conventional ion-sensitive electrode and a MOSFET device, which can be applied to the measurement of ion content in a solution. This structure has a lot of advantages as compared to the Ion- Sensitive Field Effect Transistor (ISFET). In this work, we constructed an EGFET by connecting the sensing structure fabricated with SnO2 to a commercial MOSFET (CD4007UB). From the numerical simulation of site binding model it is possible to determine some of the desirable characteristics of the films. We investigate and compare SnO2 films prepared using both the Sol-gel and the Pechini methods. The aim is an amorphous material for the EGFET. The SnO2 powder was obtained at different calcinating temperatures (200 - 500ºC) and they were investigated by X-ray diffraction (XRD), infrared spectroscopy (IR), thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The films were investigated as pH sensors (range 2-11).47848