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Abstract Background To investigate the control effect on the axial length elongation using corneal refractive therapy (CRT) with different optical zone diameters (BOZDs). We also sought to compare the difference in higher-order aberrations (HOAs), treatment zone (TZ) size and Zernike defocus coefficient with different BOZDs and seek the optimal parameter for predicting axial elongation. Methods This prospective cohort study included 7- to 14-year-olds fitted with orthokeratology (ortho-K) lenses of 5-mm (5-mm group) or 6-mm BOZD (6-mm group). Axial length (AL), corneal topography, HOAs and Zernike defocus coefficient were obtained at baseline, and 1, 3, 6, 9 and 12 months follow-up visits. Multivariate regression analyses were used to explore the association between AL change and ocular biometric parameters. Receiver operating characteristic (ROC) curve analysis was used to determine the best diagnostic value for AL change in ocular biometric parameters. Results In total, 301 participants completed the one-year follow-up. The mean AL change in the 5-mm group (0.13 ± 0.18 mm) was less than that in the 6-mm group (0.27 ± 0.15 mm) at the 12 months visit. The TZ size and decentration were smaller, while the Zernike defocus coefficient and HOAs were higher in the 5-mm group (all P

Abstract Purpose To compare changes in ocular aberrations in children wearing orthokeratology (ortho-k) lenses with a back optic zone diameter (BOZD) of 6 mm (6-MM group) or 5 mm (5-MM group) and their associations with axial elongation (AE) over two years. Methods Seventy Chinese children, aged 6 to

PurposeThe current study designed a unique type of corneal topography evaluation method based on deep learning and traditional image processing algorithms. The type of corneal topography of patients was evaluated through the segmentation of important medical zones and the calculation of relevant medical indicators of orthokeratology (OK) lenses.MethodsThe clinical data of 1,302 myopic subjects was collected retrospectively. A series of neural network-based U-Net was used to segment the pupil and the treatment zone in the corneal topography, and the decentration, effective defocusing contact range, and other indicators were calculated according to the image processing algorithm. The type of corneal topography was evaluated according to the evaluation criteria given by the optometrist. Finally, the method described in this article was used to evaluate the type of corneal topography and compare it with the type classified by the optometrist.ResultsWhen the important medical zones in the corneal topography were segmented, the precision and recall of the treatment zone reached 0.9587 and 0.9459, respectively, and the precision and recall of the pupil reached 0.9771 and 0.9712. Finally, the method described in this article was used to evaluate the type of corneal topography. When the reviewed findings based on deep learning and image processing algorithms were compared to the type of corneal topography marked by the professional optometrist, they demonstrated high accuracy with more than 98%.ConclusionThe current study provided an effective and accurate deep learning algorithm to evaluate the type of corneal topography. The deep learning algorithm played an auxiliary role in the OK lens fitting, which could help optometrists select the parameters of OK lenses effectively.

Purpose: To compare axial elongation (AE) and treatment zone (TZ) characteristics in children wearing 6 mm or 5 mm back optic zone diameter (BOZD) orthokeratology (ortho‐k) lenses over 2 years. Methods: Forty‐five (6 to <11 years of age) myopic (−4.00 to −0.75 D) children of Chinese ethnicity were randomly assigned to use the two different lens designs (23 and 22 wore the 6 and 5 mm lenses, respectively). Data collection was performed at baseline and every 6‐months after commencing lens wear. Results: After 24 months, subjects wearing lenses with a 5 mm BOZD achieved smaller TZ diameter (horizontal: 2.69 ± 0.28 vs. 3.84 ± 0.39 mm; vertical: 2.65 ± 0.22 vs. 3.42 ± 0.34 mm, p < 0.001) and less AE (0.15 ± 0.21 vs. 0.35 ± 0.23, p = 0.005) compared to those using the 6 mm design, with no difference in choroidal thickness (ChT) changes (p = 0.93). A significant increase in ChT, using pooled data analysis, was noted at the 6‐month (11.8 ± 19.77 μm, p < 0.001) and 12‐month (12.0 ± 23.7 μm, p = 0.004) visits, compared to baseline, indicating a transient change in ChT. Significant associations were noted, using linear mixed models, between AE and the TZ diameters (p < 0.003) after adjusting for baseline data. A very weak association was found between ChT changes and AE, with the effect size close to zero. Conclusions: Smaller BOZD ortho‐k lenses resulted in a smaller TZ diameter, which was associated with less AE after 2 years of treatment. The changes in ChT played a very weak role, suggesting that other factors may contribute more to the reduced AE in subjects wearing lenses having a smaller BOZD. [ABSTRACT FROM AUTHOR]

Chest X-ray (CXR) characteristics of patients with drug-resistant tuberculosis (DR-TB) depend on a variety of factors, and therefore, identifying the influence of these factors on the appearance of DR-TB in chest X-rays can help physicians improve diagnosis and clinical suspicion. Our aim was to describe the CXR presentation of patients with DR-TB and its association with clinical and demographic factors. A retrospective analysis of the CXRs of DR-TB patients in Nigeria between 2010 and 2016 was performed, reviewing features of chest radiographs, such as cavitation, opacity and effusion, infiltration and lung destruction. The association of these abnormal CXR findings with clinical and demographic characteristics was evaluated using bivariate and multivariate models, and a p-value < 0.05 was considered statistically significant with a 95% confidence interval. A total of 2555 DR-TB patients were studied, the majority (66.9%) were male, aged 29–38 years (36.8%), previously treated (77%), from the South West treatment zone (43.5%), HIV negative (76.7%) and bacteriologically diagnosed (89%). X-ray findings were abnormal in 97% of the participants, with cavitation being the most common (41.5%). Cavitation, effusion, fibrosis, and infiltration were higher in patients presenting in the South West zone and in those previously treated for DR-TB, while lung destruction was significantly higher in patients who are from the South South zone, and in those previously treated for DR-TB. Patients from the South East zone (AOR: 6.667, 95% CI: 1.383–32.138, p = 0.018), the North East zone (AOR: 6.667, 95% CI: 1.179–37.682, p = 0.032) and the North West zone (AOR: 6.30, 95% CI: 1.332–29.787, p = 0.020) had a significantly increased likelihood of abnormal chest X-ray findings, and prior TB treatment predisposed the patient to an increased likelihood of abnormal chest X-ray findings compared to new patients (AOR: 8.256, 95% CI: 3.718–18.330, p = 0.001). The finding of a significantly higher incidence of cavities, effusions and fibrosis in DR-TB patients previously treated could indicate late detection or presentation with advanced DR-TB disease, which may require a more individualized regimen or surgical intervention. [ABSTRACT FROM AUTHOR]

We conducted a retrospective study of 2555 DR-TB patients admitted to treatment between 2010 and 2016 in six geopolitical zones in Nigeria. We characterized the gender distribution of DR-TB cases and the association between demographics and clinical data, such as age, treatment category, number of previous TB treatment cycles, and geopolitical zone, with gender. The independent effects of being a male or female DR-TB patient were determined using bivariate and multivariate analyzes with statistical significance of p < 0.05 and a 95% confidence interval. Records from a total of 2555 DR-TB patients were examined for the study. A majority were male (66.9%), largest age-group was 30–39 years old (35.8%), most had MDR-TB (61.4%), were HIV-negative (76.6%), and previously treated for TB (77.1%). The southwest treatment zone had the highest proportion of DR-TB patients (36.9%), and most DR-TB diagnoses occurred in 2016 (36.9%). On bivariate analysis, age, HIV status, treatment zone, and clinical patient group in DR-TB were significantly associated with male gender. On multivariate analysis, males aged 20–29 years (AOR: 0.19, 95% CI: 0.33–0.59, p = 0.001) and HIV-positive males (AOR: 0.44, 95% CI: 0.33–0.59, p = 0.001) had lower likelihood of MDR-TB as males in the south–south treatment zone (AOR: 1.88, 95% CI: 1.23–2.85, p = 0.03), and being male and aged ≥60 years (AOR: 2.19, 95% CI: 1.05–4.54, p = 0.036) increased the probability of DR-TB. The older male population from south–southern Nigeria and women of childbearing age had lower incidence of DR-TB than men of the same age. Tailored interventions to reduce HIV and DR-TB prevalence in the general population, particularly among women of childbearing potential, and treatment support for young and older men are relevant strategies to reduce DR-TB in Nigeria.

Chest X-ray (CXR) characteristics of patients with drug-resistant tuberculosis (DR-TB) depend on a variety of factors, and therefore, identifying the influence of these factors on the appearance of DR-TB in chest X-rays can help physicians improve diagnosis and clinical suspicion. Our aim was to describe the CXR presentation of patients with DR-TB and its association with clinical and demographic factors. A retrospective analysis of the CXRs of DR-TB patients in Nigeria between 2010 and 2016 was performed, reviewing features of chest radiographs, such as cavitation, opacity and effusion, infiltration and lung destruction. The association of these abnormal CXR findings with clinical and demographic characteristics was evaluated using bivariate and multivariate models, and a p-value < 0.05 was considered statistically significant with a 95% confidence interval. A total of 2555 DR-TB patients were studied, the majority (66.9%) were male, aged 29–38 years (36.8%), previously treated (77%), from the South West treatment zone (43.5%), HIV negative (76.7%) and bacteriologically diagnosed (89%). X-ray findings were abnormal in 97% of the participants, with cavitation being the most common (41.5%). Cavitation, effusion, fibrosis, and infiltration were higher in patients presenting in the South West zone and in those previously treated for DR-TB, while lung destruction was significantly higher in patients who are from the South South zone, and in those previously treated for DR-TB. Patients from the South East zone (AOR: 6.667, 95% CI: 1.383–32.138, p = 0.018), the North East zone (AOR: 6.667, 95% CI: 1.179–37.682, p = 0.032) and the North West zone (AOR: 6.30, 95% CI: 1.332–29.787, p = 0.020) had a significantly increased likelihood of abnormal chest X-ray findings, and prior TB treatment predisposed the patient to an increased likelihood of abnormal chest X-ray findings compared to new patients (AOR: 8.256, 95% CI: 3.718–18.330, p = 0.001). The finding of a significantly higher incidence of cavities, effusions and fibrosis in DR-TB patients previously treated could indicate late detection or presentation with advanced DR-TB disease, which may require a more individualized regimen or surgical intervention.

Purpose: To present the 1‐year results of the Variation of Orthokeratology Lens Treatment Zone (VOLTZ) Study, which aims to investigate the myopia control effect of orthokeratology (ortho‐k) lenses with different back optic zone diameters (BOZD). Method: Children, aged 6 to <11 years, having myopia −4.00 D to −0.75 D, were randomly assigned to wear ortho‐k lenses with 6 mm (6‐MM group) or 5 mm (5‐MM group) BOZD. Data collection included changes in refraction, vision, lens performance and binding, ocular health conditions, axial length and characteristics of the treatment zone (TZ) area. Results: The 1‐year results of 34 and 36 subjects (right eye only) in the 6‐MM and 5‐MM groups, respectively, are presented. No significant differences in baseline demographics were found between the groups (p > 0.05). The first‐fit success rates, based on satisfactory centration at the 1‐month visit, were 100% and 94% respectively. Horizontal TZ size was 0.92 mm and 0.72 mm smaller in the 5‐MM group at the 6‐month and 12‐month visits, respectively (p < 0.05). At the 12‐month visit, no significant between‐group differences were found in the incidence of corneal staining (low grade only), lens binding and visual performance (all p > 0.05). Axial elongation was slower in the 5‐MM group (0.04 ± 0.15 mm) than the 6‐MM group (0.17 ± 0.13 mm) (p = 0.001). A significant positive correlation was observed between the horizontal TZ size and axial elongation (r = 0.36, p = 0.006). Conclusion: Clinical performance of the two ortho‐k lenses was similar, indicating that a smaller BOZD (5 mm) did not affect lens performance or ocular integrity. However, a smaller BOZD led to a reduced TZ, with retardation of axial elongation by 0.13 mm compared to conventional 6 mm BOZD ortho‐k lenses after one year of lens wear. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to compare the changes in corneal morphological characteristics in corneal topography assessments performed after wearing orthokeratology (OK) lenses with different back optic zone diameters (BOZDs). These changes included the change ratios of the apical corneal power (ACP), the maximum relative corneal refractive power (mRCRP), and the treatment zone diameter (TZD)., Methods: Data from 133 children with myopia (average age 9.50 ± 1.23 years) treated at Fudan University Eye and Ear, Nose, and Throat Hospital were retrospectively analyzed. All participants wore the same brand of tangent-design OK lens (corneal refractive therapy, CRT). According to the BOZD, the patients were divided into two groups, of 5.0 and 6.0 mm BOZD, respectively. Corneal topography was analyzed at baseline, as well as 1 day, 1 week, and 1 month after wearing the lenses, and the change ratios of ACP, mRCRP, and TZD were compared between the two groups., Results: The change ratio of the ACP did not differ significantly between the BOZD 5.0 and 6.0 groups after 1 day or 1 week of lens wear (P = 0.170 and P = 0.113, respectively). However, after 1 month of lens wear, the change ratio of the ACP in the BOZD 5.0 group was significantly larger than that in the BOZD 6.0 group (P < 0.001). After 1 month of lens wear, the mRCRP along the horizontal and vertical meridians was higher (P < 0.05) and the TZD was significantly smaller (P < 0.001) in the BOZD 5.0 group than in the BOZD 6.0 group., Conclusion: In CRT OK lenses, a small BOZD lens can produce faster corneal shaping, a larger mRCRP, and a smaller TZD, which may have a better effect on slowing ocular axial length elongation. The lens parameters are also a factor affecting the TZD., (Copyright © 2024 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: To determine whether orthokeratology (OK) induced treatment zone (TZ) diameter can be reduced by altering OK lens design, and if so the impact of modifying TZ diameter on relative peripheral refraction (RPR).Methods: 16 subjects (mean age 23.4 ± 1.5 years; 8 female) completed the study. Standard (Control) OK lens design (PJ, Capricornia, Australia) or a modified version (Test) where the back optic zone diameter was reduced, and back optic zone asphericity and intermediate lens curves were altered, were worn overnight only for 7-nights in a randomised double masked order, with a minimum 1-week wash out (no lens wear) between lens designs. Full correction of refractive error was targeted. Refraction; best corrected visual acuity (BCVA); RPR (Shin-Nippon NVision-k 5001) along the horizontal and vertical meridians; and corneal topography (Medmont E300) were measured before starting lens wear and in the morning after lens removal after the seventh night of lens wear for both lens designs. TZ diameter and decentration was calculated from corneal topography.Results: After 7-nights of wear both lens designs created -2.00D refraction effect with no significant difference in refractive effect or change to BCVA between the designs. The Test design created a significantly smaller horizontal (4.78 ± 0.37 vs 5.70 ± 0.37 mm, p < 0.001) and vertical (5.09 ± 0.51 vs 5.92 ± 0.51 mm p < 0.001) TZ diameter. The TZ was decentered inferior temporal with no significant difference between designs. There was no significant difference between the lens designs in RPR along the horizontal and vertical meridians at any measurement period.Conclusions: OK induced TZ diameter can be reliably reduced by altering OK lens design without detrimentally effecting lens centration or refractive effect. Reducing TZ diameter did not alter RPR, though measurement artifacts could be responsible for masking an effect. Longitudinal studies are needed to assess whether smaller TZ OK lens designs increase efficacy for slowing progression of myopia. [ABSTRACT FROM AUTHOR]

The aim of this study is to develop an automatic model based on deep learning techniques for determining the Treatment Zone (TZ) and Peripheral Steepened Zone (PSZ) following Orthokeratology (OK) treatment. A total of 1346 corneal topography maps were included in the study. A deep neural network based on the Segformer architecture was constructed to automatically detect TZ and PSZ. The model was optimized and trained multiple times, and the areas of TZ, PSZ, and TZ decentration were calculated based on the segmentation results. The mean Intersection over Union (mIoU) of the overall segmentation results of the model reached over 97% after multiple training with different optimization methods, and the IoU for the TZ and PSZ segmentation tasks were 98.08% and 94.54% in test set, respectively. Moreover, the model demonstrated high consistency with the expert annotation for the TZ segmentation, while a significant difference was found in the PSZ segmentation and expert annotation due to several interference factors. This study presents an efficient and repeatable system for clinical research, based on a deep neural network that accurately determines TZ and PSZ after OK treatment using the Segformer architecture. However, further deployment validation may be necessary. [ABSTRACT FROM AUTHOR]

Purpose: The current study designed a unique type of corneal topography evaluation method based on deep learning and traditional image processing algorithms. The type of corneal topography of patients was evaluated through the segmentation of important medical zones and the calculation of relevant medical indicators of orthokeratology (OK) lenses., Methods: The clinical data of 1,302 myopic subjects was collected retrospectively. A series of neural network-based U-Net was used to segment the pupil and the treatment zone in the corneal topography, and the decentration, effective defocusing contact range, and other indicators were calculated according to the image processing algorithm. The type of corneal topography was evaluated according to the evaluation criteria given by the optometrist. Finally, the method described in this article was used to evaluate the type of corneal topography and compare it with the type classified by the optometrist., Results: When the important medical zones in the corneal topography were segmented, the precision and recall of the treatment zone reached 0.9587 and 0.9459, respectively, and the precision and recall of the pupil reached 0.9771 and 0.9712. Finally, the method described in this article was used to evaluate the type of corneal topography. When the reviewed findings based on deep learning and image processing algorithms were compared to the type of corneal topography marked by the professional optometrist, they demonstrated high accuracy with more than 98%., Conclusion: The current study provided an effective and accurate deep learning algorithm to evaluate the type of corneal topography. The deep learning algorithm played an auxiliary role in the OK lens fitting, which could help optometrists select the parameters of OK lenses effectively., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Xu, Yang, Zhang, Zheng, Zheng, Liu, Zhang, Li and Ye.)

Purpose: To investigate the influence of paracentral corneal toricity using elevation data on the treatment zone decentration of spherical and toric orthokeratology (Ortho-k) lens. Methods: Corneal elevation difference (CED) was defined as the difference of corneal elevation between the two principle meridians at 8-mm chord, representing the paracentral corneal toricity. Seventy-five subjects included in this prospective study were divided into a low CED (LCED) group (LCED<30μm, n = 25) and a high CED (HCED) group (HCED≥30μm, n = 50). All subjects in the LCED group and 25 subjects in the HCED group (HCED I) were fitted with spherical Ortho-k; the other 25 subjects in the HCED group (HCED II) were fitted with toric Ortho-k. Corneal topography data from the right eyes were obtained at baseline and after 1 month of lens wear. The amount and direction of treatment zone decentration among the three groups were compared, and their relationships with corneal shape parameters, including central and paracentral corneal toricity, corneal asymmetry, flat-k and eccentricity, and lens diameter were analyzed using univariable and multivariate linear regression models. Results: The magnitude of treatment zone decentration was the greatest in the HCED I group ((LCED vs. HCED I vs. HCED II: 0.47 ± 0.15mm vs. 0.73 ± 0.15mm vs. 0.47 ± 0.19mm, respectively; ANOVA, p < 0.01). Among participants fitted with spherical Ortho-k, the magnitude of treatment zone decentration was significantly correlated to paracentral CED after adjusting for the other corneal parameters and lens diameter (standard β = 0.599, p < 0.01). No significant correlation between these parameters was found among those fitted with toric Ortho-k. Conclusions: Eyes with greater paracentral CED tend to have increased decentration of spherical Ortho-k lens, whereas toric Ortho-k appears to reduce the amount of lens decentration in eyes with CED at 8-mm chord above 30 μm. [ABSTRACT FROM AUTHOR]

An investigation of thermal processes in the course of magnetorheological polishing has been carried out. Physical and mathematical description of heat transfer from a treated surface to a polishing tool is given with consideration of the specifics of the rheological and thermophysical properties of the tool acquired by it in a magnetic field in the zone of treatment. An analytical estimate of the thermal state of a magnetorheological abrasive tool and of a treated workpiece surface is given. The temperatures of the workpiece surface and of the magnetorheological abrasive tool in the zone of their contact interaction in an inhomogeneous magnetic field are determined experimentally. The increase in the temperature of the treatment zone by ΔT = 6.6°C at an absolute maximum temperature of T = 299.6 K is recorded experimentally, with the measured temperature gradient comprising 0.073 K/s. [ABSTRACT FROM AUTHOR]

The aim of this study was to analyze the influence of corneal topography, contact lens parameters and degree of myopia on the treatment zone (TZ) and peripheral plus ring (PPR) size in orthokeratology. In this retrospective study the topographic zones of the right eyes of 106 patients (73 female, 22.16 ± 8.96 years) were analyzed in the tangential difference map of the Oculus Keratograph 5M (Oculus, Wetzlar, Germany). Using the MB-Ruler Pro 5.4 software (MB-Softwaresolutions, Iffezheim, Germany) the horizontal, vertical, longest, shortest diameters and area of the TZ; horizontal, vertical, total diameters and width of the PPR were measured. Correlations were determined between these zones and the subjects' baseline parameters (myopia; corneal diameter, radii, astigmatism, eccentricity, sagittal height; contact lens radii, toricity and total diameter) for three back optic zone diameter (BOZD) groups (5.5, 6.0 and 6.6 mm). A stepwise linear regression analysis was performed to test for TZ and PPR predictability. In the group of BOZD 6.0 correlations were found between the amount of myopia and the short TZ diameter (r = −0.25, p = 0.025); the steep corneal radius and the vertical diameter (r = –0.244, p = 0.029), the longest diameter (r = −0.254, p = 0.023) and the area (r = −0.228, p = 0.042) of the TZ; the amount of astigmatism and PPR width (r = 0.266, p = 0.017); eccentricity of the steep corneal meridian and PPR width (r = –0.222, p = 0.047). BOZD correlated significantly positively with all zones (p < 0.05). The best prediction model (R2 = 0.389) resulted with the TZ area as the outcome variable. The amount of myopia, topography and contact lens parameters influence TZ and PPR in orthokeratology. Describing the TZ by its area may provide the most accurate representation of its size. [ABSTRACT FROM AUTHOR]

To investigate the variation trend of the treatment zone (TZ) during 12 months of Orthokeratology (Ortho-K) from the perspective of the treatment zone size (TZS), decentration (TZD) and the weighted Zernike defocus coefficient of the treatment zone (C weighteddefocus ). 94 patients were included in this retrospective study, who were fitted with a 5-curve vision shaping treatment (VST) lens (n = 44) or a 3-zone corneal refractive therapy (CRT) lens (n = 50). The TZS, TZD and C weighteddefocus up to 12 months were analyzed. TZS (F (4,372) = 10.167, P ＜0.001), TZD (F (4,372) = 8.083, P ＜0.001) and C weighteddefocus (F (4,372) = 7.100, P ＜0.001) were significantly increased with time during overnight Ortho-K treatment. The TZS increased sharply from 1 week to 1 month of overnight Ortho-K (F = 25.479, P <.001) and stayed smooth then. It showed growing tendency from 6 to 12 months (F = 8.407, P =.005). The TZD (F = 16.637, P <.001) and C weighteddefocus (F = 13.401, P <.001) increased significantly until 1 month and kept stable until 12 months (all P ＞0.05). The univariant linear regression analysis showed that TZS of the last visit was correlated with baseline myopia (β = 0.219, P =.034). Also, the greater final C weighteddefocus was correlated with higher baseline myopia (β = -0.589, P ＜0.001) and higher corneal astigmatism (β = -0.228, P =.007) at the onset of lens wear with the multiple linear regression. The TZS, TZD and C weighteddefocus kept stable after 1 month of Ortho-K while the TZS had an increasing trend after 6 months. Children with higher myopic eyes or higher corneal astigmatism at baseline tended to have smaller TZS and greater C weighteddefocus at 12 months. [ABSTRACT FROM AUTHOR]

Runoff water from urbanized areas, including roads and related objects may be a source of micropollution. One of the methods limiting its migration to surface- and groundwater receivers may be the application of horizontal treatment zones enhancing natural attenuation of the soil-water environment. The aim of the presented small-scale field tests was testing the utility of mixtures of zero valent iron – ZVI, activated carbon – AC, zeolite – Z, limestone – LS, and silica spongolite – SS as reactive materials. During the 11-month experiment, runoff water samples were collected from three treatment zones and subjected to physical and chemical analyses (pH, EC, Eh, Cl − , Fe 2+ , Cd 2+ , Cu 2+ , Ni 2+ , Pb 2+ , Zn 2+ , NH 4 + , NO 2 − , NO 3 − , COD, ƩPAH, PEE). Additionally, the change of the hydraulic conductivity of the mixtures was systematically controlled. During the experiment, the highest mean values of removal efficiency of Cl − (13%) and COD (82%) were observed for ZVI/AC/Z; Ni 2+ (94%), Zn 2+ (99%) and NH 4 + (82%) for ZVI/AC/LS; and PEE (70%) for ZVI/AC/SS. Cadmium (98%), copper (100%) and lead (100%) were removed with the same intensity by all three systems. ƩPAH were removed with the same intensity at 97% by ZVI/AC/SS and ZVI/AC/LS. However, the contact of runoff water with both mixtures resulted in increased emission of NO 2 − and NO 3 − . The experiment showed also that the hydraulic conductivity of the mixtures decreased to a minimal value of 3.2 · 10 −5 m/s for ZVI/AC/Z. [ABSTRACT FROM AUTHOR]

We conducted a retrospective study of 2555 DR-TB patients admitted to treatment between 2010 and 2016 in six geopolitical zones in Nigeria. We characterized the gender distribution of DR-TB cases and the association between demographics and clinical data, such as age, treatment category, number of previous TB treatment cycles, and geopolitical zone, with gender. The independent effects of being a male or female DR-TB patient were determined using bivariate and multivariate analyzes with statistical significance of p < 0.05 and a 95% confidence interval. Records from a total of 2555 DR-TB patients were examined for the study. A majority were male (66.9%), largest age-group was 30-39 years old (35.8%), most had MDR-TB (61.4%), were HIV-negative (76.6%), and previously treated for TB (77.1%). The southwest treatment zone had the highest proportion of DR-TB patients (36.9%), and most DR-TB diagnoses occurred in 2016 (36.9%). On bivariate analysis, age, HIV status, treatment zone, and clinical patient group in DR-TB were significantly associated with male gender. On multivariate analysis, males aged 20-29 years (AOR: 0.19, 95% CI: 0.33-0.59, p = 0.001) and HIV-positive males (AOR: 0.44, 95% CI: 0.33-0.59, p = 0.001) had lower likelihood of MDR-TB as males in the south-south treatment zone (AOR: 1.88, 95% CI: 1.23-2.85, p = 0.03), and being male and aged ≥60 years (AOR: 2.19, 95% CI: 1.05-4.54, p = 0.036) increased the probability of DR-TB. The older male population from south-southern Nigeria and women of childbearing age had lower incidence of DR-TB than men of the same age. Tailored interventions to reduce HIV and DR-TB prevalence in the general population, particularly among women of childbearing potential, and treatment support for young and older men are relevant strategies to reduce DR-TB in Nigeria.

Background: The aim was to report the appearance of a pigmented ring in both eyes of two patients undergoing overnight orthokeratology. Methods: Two Caucasian patients, one male and one female, were fitted with orthokeratology lenses to correct myopia between -2.00 and -2.50 DS with Paragon corneal refractive therapy lenses worn overnight. Treatment was successful in both patients achieving uncorrected vision of 6/6 or better monocularly under high (100 per cent) and low (10 per cent) contrast conditions. Results: At the six-month visit both patients presented with pigmented rings under slitlamp examination in both eyes. The location of the ring was consistent with the corneal area being flattened for myopic correction. Clinical examination was otherwise normal. Conclusions: Despite being initially reported in Asian patients from Hong Kong, a pigmented ring related to orthokeratology treatment is also present in Caucasian patients, reducing the potential role of an ethnic link. Further large-scale studies need to be done to estimate the actual incidence of this condition and the potential implications for corneal health. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the time course of treatment zone (TZ) diameter changes in hyperopic orthokeratology (OK) lens wear from 1 h in the open eye through to seven nights in the closed eye. Methods: Twelve subjects were fitted with rigid hyperopic OK lenses. Lenses were worn in the open eye for 1 h then one night in the closed eye, separated by a washout period of 4 days. Changes in best corrected visual acuity (BCVA) and corneal topography (Medmont E-300) were measured on lens removal. The TZ, comprising the central steepened zone (CSZ) and surrounding annular flattened zone (AFZ), was measured from corneal topography. Subsequently, ten subjects wore the same lens design overnight for seven nights, and measurements were taken on lens removal and 8 h later on Days 1 and 7. Results: Both CSZ and AFZ were apparent after 1 h of hyperopic OK lens wear. CSZ decreased while AFZ increased with longer periods of lens wear. BCVA reduced with longer periods of lens wear and was associated with decreasing CSZ ( r = −0.866, p < 0.001) and increasing AFZ ( r = 0.447, p < 0.05). Conclusions: The association of changes of treatment zone size with reductions in BCVA suggests that increasing CSZ may lead to better visual outcomes in hyperopic OK. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the stability of the treatment zone (TZ) size during Corneal Refractive Therapy (CRT™) over 4 weeks of lens wear, and to determine the relationship between TZ diameter and visual, optical and subjective performance. Methods: Twenty-three myopic subjects wore CRT™ lenses overnight and removed their lenses on awakening. Visual Acuity (VA), subjective vision, refractive error, aberrations and corneal topography were measured at baseline, immediately after lens removal on the first day and 14 h later, and these measurements were repeated on days 4, 10 and 28. The TZ including the central flattened zone (CFZ) and the annular steepened zone (ASZ) was demarcated by the change in corneal curvature from negative to positive and vice versa, using the tangential difference map from the Atlas corneal topographer. Results: After overnight CRT™ lens wear, the central cornea flattened and the mid-periphery steepened (both p < 0.001). After 4 weeks of lens wear, the CFZ (±SE) increased from 3.41 ± 0.09 mm on day 1 morning to 3.61 ± 0.07 mm on day 28 morning and the diameter of the ASZ increased from 8.17 ± 0.16 mm (day 1 morning) to 8.85 ± 0.14 mm (day 28 morning) (both p < 0.001). From day 10 onwards, the CFZ and ASZ diameter were stable in the morning ( p ≥ 0.404). Throughout the day, the CFZ became smaller during the first 10 days (all p ≤ 0.022), whereas the ASZ diameter remained constant (all p ≥ 0.079). There were positive correlations between the CFZ or ASZ and residual refractive error, subjective vision and spherical aberration. The CFZ was also correlated with astigmatism and higher order aberrations, and the ASZ was positively correlated with coma ( r = 0.726 to 0.961, all p ≤ 0.042). In addition, there were negative correlations between the CFZ or ASZ and total aberration and defocus and between the ASZ and VA ( r = −0.707 to −0.953, all p ≤ 0.050). Conclusion: The TZ changed during the first 10 days. Its size was associated with VA, residual refractive error, aberrations and subjective vision. The concept of a TZ is a useful metric of visual, optical and subjective performance in CRT™ lens wearers. [ABSTRACT FROM AUTHOR]

Local heat treatment is justifiable in many cases in terms of technology and cost effectiveness, where only the most loaded working surface is subjected to hardening, while the bulk of a material remains untreated. Plasma surface hardening allows wear to be decreased and service life of heavy-loaded machine parts to be extended 2–5 times. The novel method of plasma hardening is technically and economically preferable for heat treatment of a large number of parts. One example of its application is high-speed surface hardening of all types of passenger, freight, and locomotive train wheelsets. Tests show that in all cases the amount of wear of the wheelset ridges after plasma hardening is much lower (2.5–3.0 times) than that of the ridges after standard heat treatment. [ABSTRACT FROM AUTHOR]