Optimized absorption of light in perovskite nanowire solar cells.

Metal halide perovskite nanowires (PrvNWs) have recently emerged as an interesting path for nanostructured solar cells. Here, we model the absorption of light in PrvNW arrays for varying diameter and length of the PrvNWs and period for the array by solving the Maxwell equations. For long enough bare PrvNW arrays, we find that the optimum diameter is fixed to that which places the absorption peak from the HE11waveguide mode in the PrvNWs to the vicinity of the bandgap wavelength. In contrast, when we include a transparent conductive oxide (TCO) top contact layer, the optimum diameter shifts to a larger value by 100 nm. The origin of this shift is traced to a reduced reflection at the interface between the TCO layer and the PrvNW array when the PrvNW's diameter is larger. Overall, we find that 1500 nm long PrvNWs can reach 90% of the broadband absorption potential, making this system of high interest for photovoltaics.

Obesity and incidence of colorectal polyps: a case-controlled study.

Previous essays have presented possible concordance between obesity and colorectal polyp development. However, neither for the hypothesis nor for the details general consensus exists. This study aimed to evaluate the association between higher BMI rather than the normal and colorectal polyp presentation and characteristics if any. Methods: Eligible patients based on study criteria who were candidates for total colonoscopy examination enrolled in this case-controlled trial. Controls had normal colonoscopy reports. A positive colonoscopy for any kind of polyp was followed by a histopathological study. Demographic data also was registered, and patients were categorized according to the calculated BMI. Groups were matched by both gender and status of tobacco abuse. Finally, the outcomes of colonoscopy and histopathological studies were compared between groups. Results: A total of 141 and 125 persons investigated, respectively, as patients and controls. Possible effects of gender, tobacco abuse, and cigarette smoking were declined by participants matching. Hence, we found no significant difference between groups regarding the latter variables (P>0.05). Colorectal polyps were found absolutely more in BMI>25 kg/m-2 rather than in lesser values (P<0.001). However, there was no obvious difference in the incidence of colorectal polyps between groups categorized as overweight and obese (P>0.05). Namely, even weighing over could be the risk for colorectal polyp development. Additionally, it was more expected to find neoplastic adenomatous polyp(s) with high-graded dysplasia in BMI>25 kg/m-2 (P<0.001). Conclusion: Even little changes in BMI further than the normal values can independently increase the risk of developing dysplastic adenomatous colorectal polyp(s) significantly.

A Multi-Criteria Decision-Making Model with Interval-Valued Intuitionistic Fuzzy Sets for Evaluating Digital Technology Strategies in COVID-19 Pandemic Under Uncertainty.

Coronavirus diseases 2019 (COVID-19) pandemic is an essential challenge to the health and safety of people, medical members, and treatment systems worldwide. Digital technologies (DTs) have been universally introduced to improve the treatment of patients during the pandemic. Nevertheless, only a few governments have been partly successful in executing the DT strategies. In this regard, it is critical to demonstrate a suitable strategy for the governments. This problem is built based on the experts' opinions with some conflicting criteria to evaluate various types of alternatives. Hence, this research presents a new multi-criteria decision-making (MCDM) model under uncertain conditions. For this reason, interval-valued intuitionistic fuzzy sets (IVIFSs) are employed to help decision-makers (DMs) evaluate in a broader area and cope with uncertain information. Moreover, a new extended weighting method based on weighted distance-based approximation (WDBA) and a new combined ranking approach are proposed to determine the DMs' weights and rank the alternatives under IVIF conditions. The developed weighting method is constructed based on computing the DMs' weights with objective criteria weights. Furthermore, a new ranking approach is proposed by obtaining two ranking indexes separately: The first and second ranking indexes are calculated according to the positive and negative ideal solutions distances and the nature of criteria weights, respectively. Afterward, the final values of rankings are computed by considering a new aggregating procedure. The results of the proposed model represent the first alternative as the best strategy. Comparisons between the IVIF-TOPSIS and IVIF-VIKOR methods are also provided to investigate the proposed model to determine the rankings of main alternatives. Sensitivity analyses are conducted to check the reliability and the robustness of the model. For this purpose, criteria weights are analyzed to compute the dependencies' degree of the new extended weighting method. The dependencies of the ranking model are discussed on the criteria weights as well.

Effect of Helicobacter pylori eradication in Iranian patients with functional dyspepsia: a prospective, randomized, placebo-controlled trial.

INTRODUCTION: Whether patients with functional dyspepsia (FD) should receive Helicobacter pylori (H. pylori) eradication therapy remains controversial. The objective of this trial was to evaluate the effect of H. pylori eradication therapy on dyspeptic symptoms of patients with FD. MATERIAL AND METHODS: A prospective, randomized, placebo-controlled trial of H. pylori eradication for FD was conducted. A total of 720 FD patients diagnosed by Rome III criteria were consecutively enrolled. We randomly assigned 186 H. pylori infected patients with FD to receive quadruple therapy for 14 days and 173 such patients to receive identical-appearing placebos. Severity of abdominal symptoms was assessed with the Glasgow Dyspepsia Severity Score (GDSS), and eradication of H. pylori by (13)C-urea breath test was evaluated during one year. RESULTS: The rate of eradication of H. pylori infection was 87.1% in the treatment group and 2.9% in the placebo group at 6 weeks (p = 0.001). The mean GDSS at 12 months was 4.9 ±2.8 in the treatment group, as compared to 5.2 ±3.4 in the placebo group (p = 0.064). The scores in both groups were lower than those at baseline. According to the intention-to-treat analysis, at 12 months, there was no significant difference between groups in the rate of successful treatment (48.6% in the treatment group and 51.2% in the placebo group; p = 0.84). There was no significant difference in mean symptom scores between the two treatment groups at any point during follow-up. CONCLUSIONS: The results of our study provide no evidence that H. pylori eradication leads to relief of symptoms 12 months after treatment, and there is a need for further studies.