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2022 ◽  
Vol 6 (1) ◽  
pp. 6
Author(s):  
Pavel A. Yudaev ◽  
Evgeniy M. Chistyakov

This review addresses research and development on the use of ionic liquids as extractants and diluents in the solvent extraction of metals. Primary attention is given to the efficiency and selectivity of metal extraction from industrial wastewater with ionic liquids composed of various cations and anions. The review covers literature sources published in the period of 2010–2021. The bibliography includes 98 references dedicated to research on the extraction and separation of lanthanides (17 sources), actinides (5 sources), heavy metals (35 sources), noble metals, including the platinum group (16 sources), and some other metals.


2022 ◽  
pp. 67-86
Author(s):  
Sandra Gudino Paredes ◽  
Felipe J. Jasso Pena

In a global health pandemic context, a group 16 of education Master's students met voluntarily with their tutors in a virtual research support seminar, during the Saturday mornings of the first and second semester of 2020. This study aimed to know to what extent did mentoring and human tutoring characteristics emerge in a virtual research seminar experience. Through a qualitative research approach that included the analysis of the conversations and dialogues of the recorded sessions, insights showed that some of these characteristics emerged naturally along with the sessions, but as time passed, emotional and personal aspects were appearing more often than some others, showing that students felt more comfortable talking about themselves and supporting their classmates, as well as expressing their academic doubts and project thoughts freely because of humanistic tutoring approach. Most of them achieved the goal of finishing their project chapters on time. The humanistic and professional characteristics of teachers emerged as the main factors to develop this humanistic tutoring approach.


2021 ◽  
Author(s):  
Eun-Hyang Cha ◽  
Suk-Gyu Ha ◽  
Youngwoo Suh ◽  
Seung-Hyun Kim

Abstract Background To investigate preoperative clinical features and postoperative results according to the correspondence between excyclotorsion and the paretic eye in patients with congenital unilateral superior oblique palsy (USOP).MethodsA retrospective review of medical charts was performed. The patients were divided into the accordance (ocular excyclotorsion in the paretic eye) and discordance (ocular excyclotorsion in the non-paretic eye) groups. The degree of excyclotorsion (scale, 0–4) was measured. Age, sex, hypertropia at the primary position, fixation preference, inferior oblique overaction, and degree of excyclotorsion were measured.ResultsNinety-eight patients were included in this study. There were 70 (71.4%) and 28 patients (28.6%) in the accordance and discordance groups. Sixteen patients (22.9%) in the accordance group and 12 patients (42.9%) in the discordance group were aged under 2 years (p = 0.04). A fixation preference of the paretic eye was observed in 2 (2.9%) and 8 (28.6%) patients in the accordance and discordance groups (p < 0.01). The postoperative degree of excyclotorsion in the accordance group (0.14 ± 0.39) was lower than that in the discordance group (0.28 ± 0.71) (p = 0.01). The residual postoperative excyclotorsion (>1) in the discordance group were observed in the discordance group (14 patients, 50%) and accordance group (16 patients, 22.9%) (p = 0.01).Conclusion Preoperative discordance between excyclotorsion and the paretic eye was observed in patients who were under 2 years of age and preferred fixation of the paretic eye. The postoperative degree of excyclotorsion was lower in the accordance group.


2021 ◽  
Author(s):  
Yan Xu ◽  
Jun Chen ◽  
Chun Tang ◽  
Kaidi Xiang ◽  
Lipu Cui ◽  
...  

Abstract Purpose: This study aimed to observe the changes in spherical equivalent and ocular axial length 6 months after withdrawal of 1% atropine eye gel.Methods: Due to COVID-19, the follow-up of patients in our optometric clinic who were undergoing myopia control treatment with a dropwise 1% atropine “5+3” regimen was interrupted. No return visit was made after the 3 months of at-home treatment, and follow-ups resumed 6 months after treatment withdrawal. The contralateral eye was not treated over the 9-month period. A total of 16 patients aged 11.5 years (average) were enrolled from November 2019 to March 2021 during the COVID-19 pandemic. The treated eyes formed a treatment group (16 eyes) and the contralateral eyes formed a control group (16 eyes). The changes in spherical equivalent, ocular axial length, and intraocular pressure (IOP) were compared between groups. Results: After 9 months, the changes in spherical equivalent were significantly less in the treatment group (0.00 ± 0.20 [D]) compared to the control group (-0.67 ± 0.25 [D]) (P<0.05). The ocular axial length changes were significantly less in the treatment group (0.00 ± 0.06 mm) compared to the control group (0.25 ± 0.11 mm) (P<0.05). There was no significant difference between the two groups for changes in IOP. Conclusions: Despite treatment withdrawal after 3 months, treatment with 1% atropine eye gel successfully controlled myopia progression in the 6 months after withdrawal, as evidence by no rebound increase in myopic spherical equivalent after the withdrawal.


2021 ◽  
Vol 22 (22) ◽  
pp. 12550
Author(s):  
Antonio Frontera ◽  
Antonio Bauza

In this review, several examples of the application of pnictogen (Pn) (group 15) and chalcogen (Ch) bonding (group 16) interactions in organocatalytic processes are gathered, backed up with Molecular Electrostatic Potential surfaces of model systems. Despite the fact that the use of catalysts based on pnictogen and chalcogen bonding interactions is taking its first steps, it should be considered and used by the scientific community as a novel, promising tool in the field of organocatalysis.


2021 ◽  
Vol 53 (4) ◽  
Author(s):  
Milivoje Urošević ◽  
Panče Dameski ◽  
Radomir Mandić ◽  
Goran Stanišić

A survey of the birth and mortality of European Bison (Bison bonasus bonasus L1758) conducted from 2000 to 2018 in two nurseries showed that the females in the first study group had the first mating at an average age of 42.54 months, with an interval from 23 to 84.5 months. The average age of the first mated females in the second study group was 31.67 months, with an interval from 39.5 to 66.93 months. The average time between calving for the first group females was 9.95 months, with an interval from 0.5 to 28.5 months. The calving interval for the second group was 8.53 months with variation from 1 to 32 months. The first group had a maximum of seven calves, while the maximum in the second group was 13.A total of 33 calves were born in the first group during the study period, 16 males (48.48%) and 17 females (51.51%), while 40 calves were born in the second group,16 males (40.0%) and 24 females (60.0%).The mortality rate in the first group ranged between 14.3 and 30.0%, with a mortality rate of males of 20 to 60% and for females of 16.66 to 50%. In the second group, the mortality rate was from 9.09 to 23.08%, for males 33.33% and from 11.11 to 25.0% for females. The results indicate that future studies should address greater attention to birth and mortality rates.


2021 ◽  
pp. 214303
Author(s):  
Kriti Pathak ◽  
Chandan Nandi ◽  
Sundargopal Ghosh
Keyword(s):  

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1600
Author(s):  
Gorka Alonso ◽  
Doru Michael Stefanescu ◽  
Edurne Aguado ◽  
Ramon Suarez

Sulfur, an element that belongs to group 16 (chalcogens) of the periodic table, is an excellent promoter of nucleation substrates for graphite in cast iron. In ductile iron, sulfur favors a higher nodule count, which inhibits the risk of carbides and of microporosity. It is reasonable to expect that other elements from group 16, such as selenium or tellurium, play similar roles in the nucleation of graphite. The objective of this paper was to investigate the effect of selenium on the process of graphite formation. Thermal analysis cups were poured to evaluate the nodule count and size distribution. Some of the cups were not inoculated, while others were inoculated with a Ce-bearing inoculant, or with the Ce inoculant and additions of Se. Cross-shaped castings were also poured to quantify the microporosity regions by tomography. It appears that selenium additions modify the number and size of graphite particles, as well as the volume of microshrinkage. Direct correlations between these three parameters were found. Advanced Extensive Field Emission Gun Scanning Electron Microscope (FEG-SEM) techniques were used to identify the nature of the main nucleation compounds. Selenides, combined with Mg and rare earths, were observed to serve as nuclei for graphite. Their presence was justified by thermodynamics calculations.


Author(s):  
Shazia Kanwal ◽  
Rabia Manzoor ◽  
Ghazala Iqbal ◽  
Zehwa Mazhar

Objective: To find a relationship between visual acuity and contrast sensitivity testing in low vision patients of different age groups. Effect of visual acuity and contrast sensitivity on increasing age of low vision patients. Study Design: Descriptive cross-sectional study. Materials and Methods: The study included low vision patients of different age groups. Data was collected by Performa. Visual acuity was assessed by ETDRS chart and contrast sensitivity was checked by the peli-Robson chart at different distances. Data were analyzed by using SPSS 22.00. Results: The study included a total of 64 patients with low vision of different age groups. Out of 64 patients, 31(48.44%) were males and 33(51.56%) were females. Patients with age group 1-15(15.63%). Patients with age group16-30(50%) and patients with age group above 30(34.36%). Relation between CS and VA of RE with age groups. In the age group 1-15, 2 patients have VA 0.9 and CS 0.10, in age group 16-30, 4 patients have VA 0.9 and CS 0.30 and in the age group of above 30 years 2 patients have VA 1 and CS 0.30. The relation between CS and VA of LE in different age groups of low vision patients in age group 1-15, 2 patients have VA 0.7 and CS 1.35 similarly in age group 16-30, 4 patients have VA 0.9 and CS 0.30 and in the age group above 30 years 2 patients have VA 1.3 and CS 0.75. Conclusion: It is concluded that the statistical value is significant P_ 0.00 which shows a significant result. And it shows that there is a strong relationship between visual acuity and contrast sensitivity as age increases visual acuity and contrast decreases so age has to affect visual functions.


2021 ◽  
Author(s):  
Eun-Hyang Cha ◽  
Suk-Gyu Ha ◽  
Youngwoo Suh ◽  
Seung-Hyun Kim

Abstract To investigate preoperative clinical features and postoperative results according to the correspondence between excyclotorsion and the paretic eye in patients with congenital unilateral superior oblique palsy (USOP). A retrospective review of medical charts was performed. The patients were divided into the accordance (preoperative fundus ocular excyclotorsion in the paretic eye) and discordance (preoperative ocular excyclotorsion in the non-paretic eye) groups. The degree of excyclotorsion (scale, 0–4) was measured. Age, sex, hypertropia at the primary position, fixation preference, inferior oblique overaction, and degree of excyclotorsion were measured at each visit. Ninety-eight patients were included in this study. There were 70 (71.4%) and 28 patients (28.6%) in the accordance and discordance groups, respectively. The mean age in the accordance and discordance groups was 9.2 ± 12.7 and 7.5 ± 8.9 years, respectively. Sixteen patients (22.9%) in the accordance group and 12 patients (42.9%) in the discordance group were aged under 2 years (p=0.04). A fixation preference for the paretic eye was observed in two (2.9%) and eight (28.6%) patients in the accordance and discordance groups, respectively (p < 0.01). The accordance group (2.3 ± 0.67) demonstrated a significantly higher degree of excyclotorsion than the discordance group (1.9 ± 0.64) (p = 0.03). The postoperative degree of excyclotorsion in the accordance group (0.14 ± 0.39) was lower than that in the discordance group (0.28 ± 0.71) (p = 0.01). The prevalence of residual postoperative excyclotorsion (>1) in the discordance group was significantly higher (14 patients, 50%) than that in the accordance group (16 patients, 22.9%) (p = 0.01).Twenty-eight percent of the patients with congenital USOP demonstrated excyclotorsion in the non-paretic eye. Preoperative discordance between excyclotorsion and the paretic eye was observed in patients who were under 2 years of age and preferred fixation of the paretic eye. The postoperative degree of excyclotorsion was significantly lower in the accordance group.


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