Remote-pumped concrete for infrastructure construction is a key innovation of the mechanized and intelligent construction technology. This has brought steel-fiber-reinforced concrete (SFRC) into undergoing various developments, from conventional flowability to high pumpability with low-carbon features. In this regard, an experimental study on the mixing proportion design and the pumpability and mechanical properties of SFRC was conducted for remote pumping. Using the absolute volume method based on the steel-fiber-aggregate skeleton packing test, the water dosage and the sand ratio were adjusted with an experimental study on reference concrete with the premise of varying the volume fraction of steel fiber from 0.4% to 1.2%. The test results of the pumpability of fresh SFRC indicated that the pressure bleeding rate and the static segregation rate were not the controlling indices due to the fact that they were far below the limits of the specifications, and the slump flowability fitted for remote-pumping construction was verified by a lab pumping test. Although the rheological properties of the SFRC charactered by the yield stress and the plastic viscosity increased with the volume fraction of steel fiber, those of mortar used as a lubricating layer during the pumping was almost constant. The cubic compressive strength of the SFRC had a tendency to increase with the volume fraction of steel fiber. The reinforcement effect of steel fiber on the splitting tensile strength of the SFRC was similar to the specifications, while its effect on the flexural strength was higher than the specifications due to the special feature of steel fibers distributed along the longitudinal direction of the beam specimens. The SFRC had excellent impact resistance with an increased volume fraction of steel fiber and presented acceptable water impermeability. With the mechanized and intelligent development of concrete technology, ready-mixed concrete produced in factories, transported by a concrete-mixing carrier, and placed in situ by pumping equipment has become a common concrete-placing method ,2,3. FurIndeed, there are lots of challenges in the development of pumped concrete, including the proper selection of pumping equipment that can supply a sufficient pump pressure with a continuously controllable flow of concrete in the pipeline, suitable pumping pipes that depend on the practical conditions, the required flow rate and the pumping pressure, and a pumpable concrete that influences the pumping pressure with a rational lubrication layer between the pumped concrete and inner face of pump pipe ,13,14,15Comparatively, pumped concrete with a lower dosage and particle size of coarse aggregate has a tendency to reduce the cracking resistance of concrete at an early age or under load with a greater shrinkage. This can be overcome by adding steel fibers that are randomly distributed in the concrete matrix. With the effects of confinement to deformation and bridging the micro- and macro-cracks of the concrete matrix, steel-fiber-reinforced concrete (SFRC) presents a specific performance that relates to the tensile properties, including a decreased shrinkage, especially at an early age, a strengthened freeze–thaw durability, an enhanced tensile strength and flexural toughness, and an improved impact resistance ,22. HoweObviously, the limited studies in previous reports are insufficient to develop a mature remote-pumping technology for FRC. Therefore, a deep study is necessary to make use of the outstanding performance of pumped SFRC. In this paper, a plan was made to propose a suitable design method for the mixing proportion and to determine the necessary indices representing the pumpability of SFRC for remote-pumping construction. From the point of the design requirements, the basic mechanical properties, including the cubic compressive strength that represents the strength grade, and the splitting tensile and flexural strengths that reflect the reinforcing effect of the steel fibers, were experimentally studied. In addition, important performance metrics, including the impact resistance and the water penetration of the remote-pumped SFRC, were also examined. The effects of steel fiber were analyzed based on the test results and compared with those specified in the codes for conventional SFRC.2 and Al2O3 of fly-ash with a lot of nanoscale spheroidal particles contributed to achieving a secondary hydration with the cement hydrate Ca(OH)2, which was accompanied by the tiny aggregate action and the enhancing of the interfacial transition zone, thus improving the properties of concrete [Ordinary silicate cement with a strength grade of 42.5 produced by Xinxiang Tianrui Cement Co. Ltd., Henan, China, was used with the properties summarized in concrete ,34.lf = 32.6 mm, an equivalent diameter df = 1.1 mm, and a tensile strength over 860 MPa. The steel fibers is rational to well distribute in concrete matrix [Ingot-milled steel fiber, a kind of formalized steel fiber produced by a specialized machine, provided by Shanghai Harix Steel Fiber Technology CO., Ltd., Shanghai, China, was used with a length e matrix .To obtain a sufficient flow of coarse aggregate in the fresh mix, the size of the coarse aggregate used for pumped SFRC should be limited. The maximum particle size of the coarse aggregate should be less than 20 mm for a pipe diameter of 100 mm , and it Pictures of the main raw materials including cement, fly-ash, crushed limestone, river sand, and steel fibers are exhibited in The additive was selected based on fluidity tests of the cement paste . The comThe design of the mixing proportion was carried out concerning the proper pumpability of concrete for remote-pumping construction with a target compressive strength of 48.2 MPa for a concrete strength grade of C40 . Accordi3, and the compound pumping agent dosage was determined as 1.4% of the total mass of the binders. The sand ratio varied from 44% to 54% based on the closing packing test. According to the specifications in the Chinese codes GB 50080 and GB 50081 [The mixing proportion of the reference concrete was firstly designed to provide a basis for the design of the remote-pumping SFRC using the absolute volume method ,39. A flGB 50081 ,41, the mw,f and βs,f are the water dosage and the sand ratio of the remote-pumping SFRC, respectively; mw,0 and βs,0 are the water dosage and the sand ratio of the reference concrete, respectively; F is the fiber factor; vf is the volume fraction of steel fiber; and ηf = 0.90 for the ingot-milled steel fiber.The mixing proportion of the remote-pumping SFRC was designed with reference to the absolute volume method based on the steel-fiber–aggregate skeleton packing test . Based ovf = 0.4%, 0.8%, and 1.2% , and that of the reference concrete (identified as SF0) are summarized in Finally, the mixing proportions of the remote-pumping SFRC with The pumpability of the fresh mix was determined according to the specifications of the Chinese code GB/T 50080 , and somThe rheological properties of the yield stress and the plastic viscosity of the fresh SFRC and fresh mortar were measured using an eBT-V concrete rheometer produced by Germany Schleibinger CO., Ltd., Buchbach, Germany, as shown in The cubic compressive strength of the SFRC at curing ages of 7 days and 28 days and the splitting tensile strength, the flexural strength, the impact resistance, and the water impermeability of the SFRC at a curing age of 28 days were measured, as per the specifications of the Chinese codes JG/T 472 , GB 5008A single-horizontal-shaft forced concrete mixer was used for mixing the mixes of the SFRC. The crushed limestone and river sand were mixed, which was followed by adding cement and fly-ash, water and the compound pumping agent, and finally by sprinkling steel fibers into the mix. The mix was then stirred for 5 min in total to let the steel fibers become uniformly distributed in the fresh matrix. The fresh mix was poured into standard molds and compacted on a standard vibration table. The top surface was flattened and covered with a thin film for 36 h in a lab room. Then, the specimens were demolded and moved into a standard curing room with a temperature of (20 ± 2) °C and a relative humidity of 95%. In total, 36 cubic specimens, 12 beam specimens, 24 round cake specimens, and 24 round truncated cone specimens were prepared.As summarized in As can be observed in the photos for testing the slump flow of the fresh mixes exhibited in In general, with a proper slump and slump flow, the SFRC with a 0.4–1.2% volume fraction of steel fiber could be long-distance pumped over 1200 m.As presented in Meanwhile, compared to the reference concrete, the SFRC with a 0.4% volume fraction of steel fiber had a lower pressure bleeding rate, while the SFRC with a 0.8% and 1.2% volume fraction of steel fiber had a higher pressure bleeding rate. This was attributed to the increased water dosage in the mixing proportion of the SFRC that ensured that the steel fibers were coated with enough binder paste. However, the pressure bleeding rate was much lower compared to that of 36% in the SFRC designed by Jiang et al. ,29,30 foAs exhibited in 3/h with a rated outlet pump pressure of 8 MPa. The pump pipe was 80 mm in diameter with a length of 6 m.To verify the pumpability of the fresh SFRC in practice, a pumping test was conducted in this study with a secondary structure concrete pump. As exhibited in Lmax is the maximum pumped distance, m; Pc is a rated outlet pump pressure, MPa; Pf is the pressure loss of pump system, which was Pf = 0.2 MPa in this study; ∆PH is the pressure loss per meter of pump pipe, Pa/m; k1 is the adhesion coefficient of the fresh mix to the pump pipe, k1 = 300 − S1, Pa; k2 is the velocity coefficient of the fresh mix flowing in the pump pipe, k2 = 400 − S1, Pa·s/m; S1 is the slump of the fresh mix, cm; t2/t1 is the ratio of the valve switch time to the piston pressure concrete time, which was t2/t1 = 0.3 in this study; α1 is the ratio of the transversal pressure to the axial pressure of the concrete, which was α1 = 0.9 in this study; V is the mean velocity of the fresh mix in the pump pipe, m/s; Q is the pump capacity, m3/h; and D is the diameter of the pump pipe, m.According to the specifications of the Chinese code JGJ/T 10 , the pumTherefore, the pumping distances of the fresh mixes were predicted and are listed in The test results of the cubic compressive strength of the SFRC are shown in The test results of the splitting tensile strength of the SFRC are shown in ff0 is the splitting tensile strength of the reference concrete with the same matrix as the SFRC. ff0 = 2.84 MPa according to the fitting analysis, and it was 2.77 MPa in the experimental results of this study.With reference to the specifications of the Chinese code JG/T 472 , a prediA good agreement between the experimental and the predicted results was obtained with a Pearson’s ratio of 0.978. The reinforcing coefficient of the steel fiber on the tensile strength obtained in this study was 0.765, which was almost equal to the value of 0.778 specified in the Chinese code JG/T472 . This meffm0 is the flexural strength of the reference concrete with the same matrix as the SFRC. ffm0 = 3.93 MPa according to the fitting analysis, and it was 4.03 MPa in the experimental results of this study.The test results of the flexural strength of the SFRC are shown in A good agreement between the experimental and the predicted results of the flexural strength of the SFRC was obtained with a Pearson’s ratio of 0.986. The reinforcing coefficient of 1.44 obtained in this study was higher than the value of 1.02 specified in the Chinese code JG/T47 . This meThe test results of the impact number of the SFRC at the initial cracking and the failure states are shown in As exhibited in kr can be calculated as follows:hm is the average permeable height of water, cm; T is the sustainable time, h; and H is the pressure presented by the water head, cm.The test results of the permeable height of water into the SFRC are summarized in The optimum mixing proportions of the reference concrete designed using the absolute volume method was effective for determining the key factors that determined the pumpability and compressive strength. This provided the basis for the design of the mixing proportion of the SFRC by only adjusting the main factors, including the water dosage and the sand ratio with the volume fraction of steel fiber. This ensured the similar rheological properties of the lubrication layer between the fresh SFRC and the interface of the pump pipe during the pumping process. Therefore, the pumpability of the fresh SFRC could meet the specifications for remote-pumping construction. The water-to-binder ratio of the SFRC was consistent with that of the reference concrete to remain a reliable compressive strength.With the increase in the volume fraction of steel fiber, the static segregation rate of the fresh SFRC obviously decreased and was far below the limit of 10% for pumped concrete specified in the Chinese code JGJ/T 10 . This waThe splitting tensile strength of the remote-pumping SFRC was similar to that predicted with the specified reinforcing coefficient of steel fiber for conventional SFRC. The flexural strength of the remote-pumping SFRC was much higher than that predicted using the specified reinforcing coefficient of steel fiber for conventional SFRC. This revealed that, similar to that along the lowing direction of flowable SFRC , an obviThe dispersion of the impact resistance of the SFRC increased with the volume fraction of steel fiber, although the failure pattern of the SFRC specimens was improved from the separated three blocks to the cracked parts linked by the steel fibers. This further proves that the uniform distribution of steel fibers plays an important role in ensuring the stable performance of SFRC.When the volume fraction of steel fiber increased from 0.4% to 1.2%, an increased tendency of the permeable height of water into the SFRC was found with an increased relative permeability coefficient. This is inconsistent with that the SFRC is beneficial to protect steel reinforcements. Therefore, the degree of its influence should be evaluated in the future.Concerning the construction performance and the mechanical properties of remote-pumping SFRC, an experimental study was conducted in this paper. The conclusions can be briefly summarized as follows:(1) The mixing proportion of the remote-pumping SFRC could be designed based on that of reference concrete by adjusting the water dosage and the sand ratio with the volume fraction of steel fiber. The pumpability of the fresh SFRC could be represented by indices of the slump flowability and the pressure bleeding rate. When the pressure bleeding rate met the limits of the specifications, the static segregation rate was unnecessary for the SFRC.(2) When the volume fraction of steel fiber varied from 0.4% to 1.2%, the remote-pumping SFRC had a slightly increased cubic compressive strength than and a similar splitting tensile strength to that predicted using the same reinforcing coefficient of steel fiber for conventional SFRC. The remote-pumping SFRC presented a flexural strength with a much higher reinforcing coefficient of steel fiber of 1.44 compared to the value of 1.02 specified for conventional SFRC.(3) When the volume fraction of steel fiber was increased from 0.4% to 1.2%, the entirety of the SFRC specimens had a markedly improved resistance to repeated impaction, and the failure pattern changed to being cracked into several blocks that were linked together with the steel fibers. An acceptable water impermeability was obtained for the remote-pumping SFRC.(4) Due to the increase in the sand ratio and the water dosage with the volume fraction of the steel fiber, which was carried out in order to maintain a reasonable pumpability of the fresh SFRC, the shrinkage and early cracking resistance of remote-pumping SFRC should be examined in future studies.


Near visual acuity was also significantly better, with a median of 0.54 logMAR in children compared to 0.9 in adults (p < 0.001). Near and distance visual acuity were significantly improved by fitting magnifying visual aids (p < 0.001). After fitting, near visual acuity averaged 0.3 logMAR, and distance visual acuity, 0.7. The most commonly prescribed aids were optical vision aids, which 68.5% of the patients received; 43.8% received electronic aids. In children, optical aids were more frequently prescribed, and in adults, electronic and acoustic aids (p < 0.001). (4) Conclusion: Visually impaired patients can regain the ability to read and improve distance vision by using individually adapted and tested magnifying vision aids, often with optical aids alone. Differences between children and adults could be discovered in the etiology and severity of visual impairment, as well as in the provision type of low vision aids.(1) Background: This study aims to highlight differences in the etiology and fitting of low vision aids in visually impaired children and adolescents in comparison to adults. (2) Methods: A retrospective data collection from visually impaired patients presenting to obtain assistive devices from 1 January 2016 to 30 April 2020 was conducted. A total of 502 patients were included. Inclusion criteria were a minimum age of 4 years and the chart notation of a best-corrected distance visual acuity in the patient record prior to the fitting of magnifying visual aids. (3) Results: Of the 502 patients, 147 (29.3%) were children under the age of 18 years. The most common cause of visual impairment in children was albinism, and in adults, it was age-related macular degeneration (AMD). Children showed better distance visual acuity, with a median of 0.88 logMAR (Logarithm of the Minimum Angle of Resolution) compared to 1.0 in adults ( According to the World Health Organization (WHO), visual impairment can be classified by the best-corrected visual acuity in the better seeing eye. Mild vision impairment is defined as a visual acuity worse than 0.3 logMAR, moderate vision impairment as worse than 0.5 logMAR, severe vision impairment as worse than 1.0 logMAR, and blindness as worse than 1.3 logMAR [Worldwide, approximately 252 million people are affected by some degree of vision impairment, of which 36 million are blind as defined by the WHO. Vision impairment does not only affect adults but also affects children and adolescents. According to projections, there were around 19 million visually impaired and blind people worldwide under 15 years of age in the year 2015 .Due to impaired vision, everyday life is greatly affected in many areas. Both reading ability and distance vision can be impaired so that the recognition of faces and facial expressions; the reading of small print, newspapers, and forms; and the ability to drive can be impaired or may be impossible. These limitations in activities of daily life (ADL) often reduce the quality of life for visually impaired people ,6. ChildThe rehabilitation of visually impaired patients covers a wide range of possible methods. Magnifying vision aids are available specifically to improve reading ability. These include, first and foremost, optical aids such as glasses and magnifying glasses, as well as electronic aids such as screen readers, tablet readers, text-to-speech devices, and, recently, also smartphones and tablets. So-called monoculars are also part of the magnifying visual aids category but are used for distance magnification. Other practical steps include the good illumination of rooms, training of eccentric vision, and paying attention to higher contrast, as well as mobility training, using long canes and guide dogs, and further training in practical life skills ,9. SeverThis study focused on the collection and analysis of retrospectively acquired data on visually impaired patients who presented themselves in the “KiOLoN”  section of the Department of Ophthalmology at the Saarland University Medical Center, Homburg/Saar, Germany. There, the testing and fitting of magnifying vision aids were performed on adults and pediatric patients. The aim was to assess both the current situation of the patients as well as the current treatment standards of low vision therapy. A special focus was the identification of differences in the etiology of visual impairment and the provision of aids for children and adolescents compared to adult patients, with the assumption that children have a higher capacity to compensate their impairment and are thus able to cope better with the adaption of visual aids. An additional interest, especially concerning the elderly patients with acquired low vision, was to find differences in visual aid fitting in spite of having the same underlying disease .® software (www.fidus.de (accessed on 2 October 2023), Arztservice Wente GmbH, Frankfurter Landstraße 117, 64291 Darmstadt, Germany) were collected in an SPSS database , Armonk, New York, USA) [The present study involved a retrospective data collection. Included in the study were patients who presented themselves at the “KiOLoN” section of the Department of Ophthalmology at Saarland University Medical Center, Homburg/Saar in the period from 1 January 2016 (date of introduction of electronic patient records) to 30 April 2020 and had low vision forms in their patient records. In order to receive low vision forms, the patients had to have been seen during the specialized low vision consultation hours. To capture consultative provision of low vision aids, patient records from this time period with diagnosis codes E70.3 “albinism”, Q13.1 “absence of iris ”, H47.2 “optic atrophy”, H53.5 “achromatopsia”, and H35.5 “hereditary retinal dystrophy” as the main diagnosis were manually reviewed for low vision services and prescription of assistive devices and included in the study, if present. Inclusion criteria were a minimum age of four years at presentation, for better comparability of visual acuity due to the usage of different tests , and a best-corrected distance visual acuity available in the patient record as baseline before fitting of magnifying vision aids. Patient data previously digitally recorded using Fidusrk, USA) ,11,12. Ageneral information and medical history;functional findings;provision of low vision aids.The information collected in the database was specifically categorized on the following parameters. Said categories were:General information on medical history included name, gender, age at presentation, and ocular main and secondary diagnoses. Within the category of functional findings, patients’ subjective residual visual function and visual acuity were recorded. For the subjective residual visual function category, patients’ anamnestic data on the ability to perform activities of daily living (ADL) and reading ability were recorded. In particular, the ability to read newspapers and to perform shopping and other duties, as well as daily hygiene and other tasks, such as putting on clothes independently, were given importance in relation to the underlying visual impairment. Children who could not yet read due to age were excluded from this category. Consideration was also given to the respective ages of the children regarding the practicality of the ADL. Visual acuity was recorded for objectifiable classification of the severity of the patients’ vision impairment and assessment of the effectiveness of magnifying vision aids. For this purpose, the visual acuity values of both patient eyes were determined separately as decimal numbers. Another component was the recording of both the binocular near visual acuity before fitting of the magnifying vision aids as well as the near and distance visual acuity with use of the fitted vision aid (cum correctione: c.c.). Newspaper reading with a near visual acuity c.c. of 0.3 logMAR was accredited as a reference to determine magnification requirements. For better comparability, all visual acuities in this publication were recorded in logMAR.A central component of the database was the recording of the provision of aids to visually impaired patients. The subdivision was initially conducted into the categories “optical aids”, “electronic aids”, “adaptive aids”, “acoustic aids”, and “other aids”. Each of these categories was then further divided according to different possible aids. ® SPSS® Statistics, version 26, International Business Machines Corporation (IBM), Armonk, NY, USA). For statistical comparison in independent variables, the Wilcoxon–Mann–Whitney test was used; when comparing dependent variables, the Wilcoxon signed-rank test was used. To detect correlations between the nominally scaled variables, the chi-square test was used. For all statistical tests used, the significance level was set at 5% (α = 0.05).Statistical analysis of the data was performed using SPSS software version 26.0  and was approved by the same committee before the data collection was started .n = 355) and 29.3% were children (n = 147) aged between 4 and 17 years. For the analysis of certain parameters, the study population was additionally divided into the following age groups: 4–12 years, 13–17 years, 18–30 years, 31–59 years, and over 60 years of age. The age distribution as part of the description of the study collective can be seen in n = 259) female to 48.4% (n = 243) male patients. Looking at the gender distribution in children and adolescents separately from that in the adult population, a shift towards the male gender could be observed in children under 18 years, with 59.9% (n = 88), and towards the female gender in adults, with 56.3% (n = 200).A total of 502 patients met the inclusion criteria and were included in the study. Of these, 70.7% were adults between the ages of 18 and 99 years (n = 187), and albinism, with 21.5% (n = 108). Children showed significantly different causes compared to adults (p < 0.001 in the chi-square test). The most frequent main diagnosis in children was albinism, with 61.9% (n = 91) and in adults, AMD, with 52.7% (n = 187 patients), followed by glaucomatous optic atrophy, with 7.6% (n = 27), and diabetic retinopathy, with 6.2% (n = 22). The main diagnosis of each of the patients with the greatest impact on their visual acuity was recorded as the cause of their vision impairment. The most frequent main diagnoses were age-related macular degeneration (AMD), with 37.3% , “corneal related vision loss” , “colour vision defects” , “cataract” , and “glaucomatous optic atrophy” . With increasing age, a significant increase in the frequency of the presence of at least one secondary ocular diagnosis was found (p < 0.001 in the chi-square test).In addition, secondary ocular diagnoses were considered. The most frequent secondary ocular diagnoses were “ post cataract surgery” (p = 0.013 in the Wilcoxon–Mann–Whitney test); the presence of secondary diagnoses showed no statistical differences. Patients with aniridia showed the lowest visual acuity, with a mean of 1.1 logMAR, followed by achromatopsia and myopia magna, both with a mean visual acuity of 1.15 logMAR. Patients with cerebral causes of vision loss showed the best visual acuity, with a mean of 0.65 logMAR, followed by Retinitis pigmentosa (mean: 0.7 logMAR) and syndromic tapetoretinal dystrophy (mean: 0.75 logMAR).A significant influence on the visual acuity of the patients could be shown for the main diagnoses (p = 0.001 in the Wilcoxon–Mann–Whitney test). The median distance visual acuity in children was 0.9 logMAR , compared to 1.0 logMAR in adults . The median near visual acuity in children was 0.54 logMAR , and in adults, it was 0.9 logMAR . Overall, 48% percent of the study population (n = 241) could be assigned to the category of moderate vision impairment at presentation according to the WHO classification. Approximately 43% (n = 215) already suffered from severe vision impairment or blindness.The median visual acuity of both patients’ eyes in the total population was 1.0 logMAR  and the binocular near visual acuity was 0.8 logMAR . Children showed significantly better distance and near visual acuity even before the aid was fitted (n = 53). A total of 6% showed central scotoma (n = 32). However, 75.5% of the patients (n = 375) had no record of loss of visual field. Therefore, no further conclusions could be drawn with regards to the main diagnoses or visual acuity of the patients in this study.Additionally, loss of visual field was included as part of the Low Vision assessment. The concentric restriction of the visual field was the most common cause of loss of visual field, affecting 10% of the study population (n = 220) had lost their ability to read. Adults stated significantly more frequently than children that they could no longer read (p < 0.001 in the chi-square test). A total of 58.3% of the adults (n = 207) stated that they could no longer read, compared to only 8.8% (n = 13) of the children. This could also be shown for the different age groups so that with increasing age, the subjective reading ability was assessed as growing increasingly worse (p < 0.001 in the chi-square test). In addition to the objectifiable visual performance on the basis of visual acuity, anamnestic information on the reading ability and feasibility of activities of daily living (ADL) of the patients was evaluated. A total of 43.8% of the patients (p < 0.001 in the Wilcoxon–Mann–Whitney test). The median visual acuity of patients who reported that they could no longer read was 1.1 logMAR . For patients who could still read independently, the median visual acuity was 0.7 logMAR . Children also rated their visual ability better than adults in terms of the feasibility of ADL. In the population of the over-17-year-olds, the indication of needing help or complete supervision with ADL occurred significantly more often (p < 0.001 in the chi-square test). Again, there was a connection to the patients’ visual acuity so that those with poorer visual acuity more often reported needing partial or full assistance with daily living. The median visual acuity for patients with full assistance was 1.3 logMAR . In comparison, the median visual acuity of patients who could perform ADL independently or needed some assistance was 0.9 logMAR .Overall, the subjective assessment of visual performance, measured via reading ability, was associated with the patients’ visual acuity so that with decreasing visual acuity, reading ability was also assessed as growing increasingly poor (n = 490) of the patients. Adaptive aids were prescribed most frequently, constituting 34.5% (n = 345) of all aids, followed by optical aids, which constituted 34.4% (n = 344). n = 999 tools).Finally, the supply of aids to the patients was considered, and the prescribed aids were assigned to the groups named “adaptive”, “optical”, “electronic”, “acoustic”, and “other” aids. Overall, suitable aids could be found for 97.6% (p < 0.001 in the chi-square test). A total of 95% (n = 114) of the 4–12-year-olds and 88.9% (n = 24) of the 13–17-year-olds received at least one visual aid, compared to only 58% of all adults (n = 206). In contrast, electronic (p = 0.014 in the chi-square test) and acoustic (p = 0.002 in the chi-square test) aids were prescribed more frequently for the over-17-year-olds. The group over 60 years of age received electronic aids most frequently, with 50% (n = 145) of all patients in this age group having received them. Acoustic aids were also most frequently fitted in the over-60-year-olds in 10% (n = 29) of the age group. Children received optical aids more often than adults (p < 0.001 as per Wilcoxon–Mann–Whitney test). Patients who had an electronic aid fitted had a median distance visual acuity of 1.1 logMAR . The majority of the population (n = 382) received more than one device during the fitting of low vision aids. Therefore, no single device could be determined with regards to the best improvement in near visual acuity.In addition, a connection between the prescribed devices and the visual acuity of the patients was found. With low visual acuity, electronic, acoustic, and other aids were increasingly prescribed; with better visual acuity, optical and adaptive aids tended to be prescribed. The median distance visual acuity of patients for whom optical aids were not sufficient was 1.3 logMAR . Patients who later received an optical aid had a median distance visual acuity of 0.9 logMAR before adjustment . On average, the improvement in near visual acuity equaled 0.51 logMAR . There was no statistically significant difference in the use of optical versus electronic aids (p = 0.691 in the Wilcoxon–Mann–Whitney test). The mean distance visual acuity with adjusted visual aids was 0.6 logMAR (SD ± 0.7). The greatest possible improvement in distant visual acuity was achieved with monoculars. Loss of contrast sensitivity showed no statistical influence on visual acuity after the fitting of low vision aids. Both near and distance visual acuity improved with aid fitting. Distance visual acuity could be improved, on average, by 0.2 logMAR . The mean improvement of distance visual acuity in children was 0.18 logMAR, compared to 0.21 logMAR in adults. After adaption, near visual acuity within the total population averaged 0.3 logMAR (SD ± 0.76), which was a statistically significant improvement compared to near visual acuity without aids  had already lost their ability to read due to their vision impairments. Children and adolescents, who had significantly better near and distance visual acuity at presentation, rated both their reading ability and the feasibility of performing ADL better than adults due to the better compensation of congenital low vision. In addition, this may have been influenced by many different factors and not merely by visual acuity. Mental and other comorbidities play a major role in the lives of visually impaired patients of all ages . DepressReferring to the underlying diseases as the causes for vision impairment, the diagnoses recorded in this study largely coincided with the causes already known in the literature. As in this study, Flaxman et al. 2017)  and Nguy  and NguAs limitations of this study, the bias towards the large number of adults should be stated. This was due to the fact that children in particular have wider access to assistive technology in Germany through early intervention and support measures at kindergarten and school. However, adults could also receive assistive devices, for example, through their general eye-care-practitioners. As this, unfortunately, is not a consistent approach, it leads to leaving out a significant number of visually impaired patients who are not referred to or informed about specialized low vision centers. Additionally, the shift towards children with albinism should be mentioned. The fact that albinism accounted for such a large proportion of diseases in this population was probably due to the fact that the center of medical advisory services for the albinism self-help-group in Germany  is located at the Saarland University Medical Center in Homburg/Saar . HoweverUltimately, this study showed that near and distance visual acuity could be improved through visual aids, perhaps merely through optical aids such as magnifying glasses alone. With regards to the findings regarding the different etiologies, severity of vision impairment, and differences between children and adolescents compared to adults, it should be acknowledged that the fitting of low vision aids remains a personalized fitting method and should be a source of help and improvement in an individual’s daily life and integration into society. The individual aim should be to have as much magnification as necessary but as little as possible to minimize distortion effects.Due to demographic change, vision impairment in the elderly is expected to increase in the following years . TherefoLooking towards the future of low vision services, the progressed stadium of moderate to severe vision impairment, and even blindness at first presentation, need to be taken into consideration. Lam et al. (2013)  and JoseFurther research might be conducted both in the field of the domestic use of visual aids as well as in keeping up with patterns in the fitting of low vision aids in the course of advancing technical developments. Larger cohorts and multicenter studies could help in gaining a global view of low vision aid provision, as well as in implementing and making use of data collected in registers for the blind and visually impaired.


With the rapid development of artificial intelligence, the electronic system has fallen short of providing the needed computation speed. It is believed that silicon-based optoelectronic computation may be a solution, where Mach–Zehnder interferometer (MZI)-based matrix computation is the key due to its advantages of simple implementation and easy integration on a silicon wafer, but one of the concerns is the precision of the MZI method in the actual computation. This paper will identify the main hardware error sources of MZI-based matrix computation, summarize the available hardware error correction methods from the perspective of the entire MZI meshes and a single MZI device, and propose a new architecture that will largely improve the precision of MZI-based matrix computation without increasing the size of the MZI’s mesh, which may lead to a fast and accurate optoelectronic computing system. Benefiting from the era of big data, the rapid growth of the Internet provides sufficient training datasets for functioning artificial intelligence (AI), which has also become a hot spot in the current technological revolution. However, artificial intelligence has conventionally relied on electronic processors, with its computing power being greatly determined by transistor numbers and capabilities; managing the massive amount of data necessitates additional computing resources. In the post-Moore era, the increasing transistor numbers can no longer keep up with the computing power demand of artificial intelligence, and electronic computation is therefore stuck in a bottleneck ,2,3. On The fabrication techniques for silicon photonics are advancing rapidly, enabling the creation of large-scale and complicated circuits and paving the way for low-loss and low-cost optoelectronic devices . These dThe optoelectronic matrix computation implemented by the Mach–Zehnder interferometer is a kind of analog computation, in which computational precision is the most important and should be treated with special attention. However, the performance of silicon photonic devices is sensitive to the influence of environmental disturbances ,15,16,17In this paper, the Mach–Zehnder interferometer method of achieving optoelectronic matrix computation is introduced in In 1994, Reck et al.  proposedA common Mach–Zehnder interferometer consists of an external phase shifter (φ), an internal phase shifter (θ), and two 50:50 beam splitters ) or multimode interference couplers (MMI)), as shown in S isP1 and P3 are the transmission matrices of the external phase shifter and the internal phase shifter, respectively; C2 and C4 are the transmission matrices of the beam splitter on the left side of the MZI and the beam splitter on the right side of the MZI, respectively. Among them, the left and right beam splitters are considered as ideal 50:50 beam splitters. Hence, MZI transmission matrix S can be written as [φ and θ are phases produced by the external phase shifter and the internal phase shifter, respectively. Obviously, we can produce different phases through these two phase shifters to implement two-dimensional unitary matrices with different elements. For an N-dimensional unitary matrix, the MZI’s transmission matrix can be generalized as Tn,m :U(N), can be reduced by right multiplying Tn,m , namely,For an MZI device, transmission matrix itten as (2)S=1/2D, with elements of modulo 1 is obtained.The N-dimensional unitary matrix’s dimension can be continued to be reduced according to the above dimensionality reduction method, and finally, a diagonal matrix, LetIt can be seen from the previous theoretical derivation that the final implementation of the N-dimensional unitary matrix will be a triangular mesh with N-1 MZIs in the N row and N-2 MZIs in the N-1 row. Based on the above theory, in 2017, Shen et al.  experimeThe N-dimensional unitary matrix implemented by MZI meshes has some deviations from the needed matrix in actual computation. On the one hand, the triangular mesh of the Reck design leads to an inconsistent optical loss of each output, and the larger mesh is, the greater the optical loss difference of each output, and the higher the total losses. On the other hand, more importantly, the beam splitter in MZI cannot implement the ideal 50:50 beam splitter due to the hardware error generated by the fabrication and the non-uniformity of the material, which leads to the deviation of the transmission matrix and affects the final computation.S′ can be expressed asThe non-ideal 50:50 beam splitter transmission matrix can be expressed as follows:Obviously, the MZI’s transmission matrix changes because of two non-ideal beam splitters, which is inconsistent with the transmission matrix in the ideal case, which leads to the deviation between the N-dimensional unitary matrix implemented by the MZI meshes and the theoretical one.In terms of the hardware error in the N-dimensional unitary matrix transformation implemented by the MZI meshes introduced in In 2016, Clements et al.  proposedTn,m, but by both right multiplying Tn,m and left multiplying T−1n,m, as shown in The improvement of the rectangular mesh is specifically manifested in the process of decomposition of the N-dimensional unitary matrix into a series of two-dimensional unitary matrices. The decomposition process does not reduce the dimensions by right multiplying Tn,m and a diagonal matrix D, there are matrix T−1n,m and another diagonal matrix D′, with T−1n,m D′ = D Tn,m, and we obtain a right-multiplication dimensionality reduction operation similar to that in Equation (7).For a matrix Shokraneh et al.  experimeIn order to solve hardware errors introduced by the non-ideal 50:50 beam splitter, Lopez-Pastor et al.  presenteFor an N-dimensional unitary matrix, the above Equation (13) can be written asAi)( and Bi)( areU(N), can be decomposed into a product of phase masks and Fourier transforms. As shown in Finally, The N-dimensional unitary matrix, Pai et al.  proposedHowever, the redundant mesh increases the size of the MZI meshes, which inevitably leads to an increase in the optical loss of the entire mesh. In a small mesh, the increased optical loss is within an acceptable range, and the computational precision of the MZI meshes is better improved.In addition to the above improvements in the MZI’s mesh, more researchers focus on the improvement of a single MZI device. The improvement of a single MZI device is mainly carried out by adding redundant phase shifters and beam splitters to improve the tunable degrees of freedom of the MZI, so as to correct its hardware errors.E1 from only one port of the MZI, the output optical powers out_1P and out_2P of the two output ports areFor a MZI with non-ideal beam splitters, where neither of the two beam splitters has an ideal 50:50 beam splitter ratio, the transmission matrix is given by Equation (10). When we input optical signal When i et al.  proposedS″ can be expressed asAlthough this architecture improves the extinction ratio of the MZI and corrects its transmission matrix to a certain extent, the correction of the transmission matrix is not complete. When complete extinction is achieved, MZI transmission matrix S (Equation (3)). Consequently, errors may still arise during matrix computations, especially when dealing with large-scale MZI meshes.It is evident that the transmission matrix of MZI undergoes a slight correction, yet it still deviates from the ideal MZI transmission matrix’s Miller et al.  presenteaP and bP:aR and bR represent errors of the left beam splitter and the right beam splitter, respectively. The transmission matrix, LP, of the MZI as a beam splitter can be expressed asNow, we will illustrate the error correction process of DMZI. For instance, considering the MZI on the left, we should adjust its beam splitters to a 50:50 split. The transmission matrix of two beam splitters in this MZI can be expressed as E1, from only one port of MZI, the output optical power, outP, of one of the two output ports isThis can be rewritten asThus, if this MZI is used as a 50:50 beam splitter, Therefore, the split ratios of the fabricated power from 85:15 to 15:85 can be compensated by adjusting the split ratio of the two tunable beam splitters back to 50:50. Two redundant beam splitters and two redundant phase shifters can completely correct the transmission matrix of MZI. Wilkes et al.  proposedR, from Equation (3), is:R can be represented on a complex plane, as shown in However, the size of the MZI also increases significantly. The increase in optical loss brought about by redundant beam splitters and phase shifters is also a problem to be considered in large-scale MZI meshes. Moreover, the transmission matrix of a real MZI as a beam splitter is different from that of the ideal one; when the ideal MZI is used as a 50:50 beam splitter, its transmission matrix R′, from Equation (10), isR′ can be represented on a complex plane, as shown in For a real MZI, when it is used as a 50:50 beam splitter, its transmission matrix By comparison with Based on the above works, Hamerly et al.  proposedThe other one is MZI + crossing, which can only correct correlated device errors. Because the errors of the right and left beam splitters are consistent, the added cross waveguide rotates the “forbidden regions” by 180° to achieve complete extinction. Thus, this architecture has bandwidth tolerance. However, due to the errors of the right and left beam splitters being usually inconsistent, this architecture only exhibits good bandwidth tolerance but cannot correct the beam splitter error and eliminate limitations to matrix computation. Compared to the Suzuki design and Miller design, these two MZI architectures are smaller in size and do not add redundant phase shifters, but the hardware error correction is not good enough.Bandyopadhyay et al.  used redS′, from Equation (10), can be rewritten as:For the MZI with non-ideal 50:50 beam splitters, the transmission matrix S (Equation (3)), we should find the S. The condition to each S produces the following expression for To implement a desired unitary Therefore, the beam splitter errors restrict S. In accordance with Equation (36), the architecture shown in Assuming that To overcome hardware errors in MZI meshes during the implementation of matrix computation, the primary strategies include increasing the tunable degrees of freedom of MZI meshes. This involves adding redundant beam splitters and phase shifters. However, incorporating a redundant mesh and improving a single MZI device may result in an increase in the size of the MZI mesh, as shown in In 2001, a study report  was condHere, we propose a new MZI architecture, where we replace the 50:50 beam splitter in the common MZI with a tunable DC/MMI that takes into account hardware error correction and mesh size, as shown in To summarize, this paper introduces the method of using a MZI’s mesh to implement any finite dimensional unitary matrix transformation, along with an analysis of the effects of hardware errors during matrix computation based on the MZI. Addressing MZIs’ hardware errors is crucial to achieving large-scale matrix computation. To eliminate the hardware error of an MZI, various improvement works have been carried out on the entire MZI mesh and a single MZI device. It is important to note that correcting these errors can lead to an increase in an MZI’s mesh size, which is also a significant concern. The trade-off between hardware error correction and mesh size requires more innovative works in artificial intelligence, materials, optics, device manufacturing and other related fields.In this paper, a new MZI architecture is proposed which replaces the 50:50 beam splitter in the common MZI with the tunable DC/MMI. This MZI is designed to take into account both hardware error correction and mesh size concerns. The tunable beam splitter-based MZI provides a new approach for more accurate large-scale matrix computation based on the MZI’s mesh.


Epinephelus lanceolatus) is an economically important yet under-researched species, still reliant on ‘trash fish’ or generic aquafeeds. The transition toward sustainable formulations is contingent on establishing requirements of target species for limiting nutrients, among which the sulfur amino acids (methionine and cysteine) commonly limit fish growth. Further, there remains significant conjecture around the role of the sulfonic acid taurine in marine aquafeed formulation and its relationship to sulfur amino acids. To develop a species-specific feed formulation for giant grouper, dietary methionine was modulated in a dose-response experiment to achieve five graded levels from 9.5 to 21.5 g/kg, including an additional diet with methionine at 18.6 g/kg supplemented with 8 g/kg taurine. The mean (±SD) cysteine level of the diets was 4.5 ± 0.3 g/kg. Each diet was randomly allocated to triplicate tanks of 14 fish (83.9 ± 8.4 g). The best-fit regression for growth showed that the optimal dietary methionine content was 15.8 g/kg and the total sulfur amino acid content was 20.3 g/kg. Inadequate dietary methionine content triggered physiological responses, including hepatic hyperplasia and hypoplasia at 9.5 and 21.5 g/kg, respectively, and high aspartate transaminase levels at 18.9 g/kg. Moreover, inadequate dietary methionine contents resulted in higher densities of mixed goblet cell mucin and reduced absorptive surface area of posterior intestinal villi. Our results suggest that adequate levels of methionine, but not taurine, improved posterior intestinal conditions and liver homeostasis. These findings may aid in formulating aquafeeds to optimize gastrointestinal and liver functions in juvenile giant grouper.Giant grouper ( The optimal supply of essential nutrients is critical to maintain and improve the health, growth, stress tolerance, and physiological homeostasis of farmed, carnivorous fish Trichet . ConcomiTSAA) requirement. While dietary Met can meet the entire requirement for sulfur amino acids, its bioconversion to endogenous cysteine is unidirectional, meaning that dietary cysteine can only meet the component of the TSAA requirement specific to Cys and its downstream metabolites. In fish, Cys can contribute up to 60% of the TSAA requirement  is one of the key limiting amino acids in protein sources. Fish fed Met at sub- and supra-optimal levels undergo significant metabolic shifts toward protein catabolism and reduced protein turnover, impairing organ function and growth , hereafter referred to as GG, is an economically important aquaculture species in Asia and increasingly popular in Australia due to its rapid growth, high value, and meat quality   assess Tau’s effectiveness in promoting the growth and well-being of GG at dietary levels that meet the TSAA requirement, and (3) use quantitative histomorphological and chemical assessments of hepatic and intestinal tissues to elucidate the effects of adequate and inadequate dietary TSAA and taurine.Thus, this study had the following goals: (1) quantify the The experiment of this study was approved by the James Cook University’s Animal Ethics Committee, Townsville, Australia .TSAA requirements and effect of dietary Tau in a SAA replete diet on the performance of GG were quantified by conducting a feeding trial that applied a factorial dose-response design. Six isoproteic (579.7 ± 0.34 g/kg) and isoenergetic (19.08 ± 0.45 MJ/kg) diets were formulated to contain either one of five incrementally increasing levels of Met  at a Tau content of 1.8 ± 0.05 g/kg. These supplemental amino acids replaced glycine on an isonitrogenous basis. An additional diet was formulated to contain Met at 18.6 g/kg with a dietary Tau level of 8.0 g/kg , fitted with a 1-mm screen. All dry ingredients were mixed in a cement mixer for 1.5 h, forming the basal diet, and split into six equal parts. Each part was supplemented with crystalline DL-Met, Tau, L-glycine, and diatomaceous earth according to Table Juvenile GG were obtained from The Company One Pty Ltd., in Cairns, QLD, Australia, and transported to the Marine and Aquaculture Research Facility (MARF), James Cook University, Townsville, QLD, Australia. Fish were prophylactically treated with formalin (250 ppm for 25 min) upon arrival. Before the start of the feeding trial, GG were allowed to acclimate to a commercial floating pellet . Subsequently, 252 fish were individually selected based on body weight (83.93 ± 8.37 g) and stocked in groups of 14 fish into 100-L rectangular tanks in an indoor RAS. Each diet was randomly assigned to three tanks. Fish were fed to apparent satiation once daily at 10:00 AM, and feed intake was recorded daily. The trial was held under controlled conditions at a water temperature of 28.0 ± 0.1 °C and a photoperiod of 11 L:13 D (photoperiod of the season) using overhead LED lamps. Water quality was recorded daily and maintained as follows: pH 7.6 ± 0.1, salinity 31.9 ± 2.7 ppt, ammonia 0.21 ± 0.15 ppm, nitrite-N 0.8 ± 0.6 ppm, nitrate-N 57.7 ± 41.7 ppm, and dissolved oxygen 110.0 ± 21.5% saturation. The experiment was conducted for 38 days.d = 38), groupers were euthanized by an overdose of AQUI-S  before individually measuring the total length, total weight, viscera, and liver weight of all GG (n = 252).Based on unpublished data on gut transit time generated by the aquaculture nutrition laboratory at James Cook University , GGs were last fed 9 h prior to sampling to ensure the timely collection of sufficient fecal material for subsequent digestibility assessment. At the completion of the feeding trial (n = 14) were pooled from fish from the same tank and stored at −20 °C for subsequent digestibility analysis.Blood samples were collected from the caudal vein of fish using EDTA (10%)-coated syringes  and needles   were trimmed to approximately 3 mm, placed into cassettes, then dehydrated through a graded series of 70%, 80%, 85%, 90%, 95%, and 100% ethanol , and embedded in paraffin wax . Transverse sections (~4 μm) were prepared using a rotary microtome  and mounted onto slides. Liver and intestinal tissues were stained with hematoxylin and eosin (H&E) for quantitative morphometric and cytological evaluations. Additionally, intestinal tissues were stained with a combination of alcian blue (AB) at a pH of 2.5 and periodic acid-Schiff (PAS) to detect neutral , acid , and mixed  mucins from goblet cells. All stained slides were scanned using an automated slide scanner  at 40× magnification.Fixed liver and posterior intestinal tissues from a total of four fish per tank (2), assess the presence/absence of nucleus (%), and determine nucleus centricity in (μm2) , and bile duct wall circumference (μm) using Aperio Image Scope (v.12.4.0.5043)  of microscopic liver scans per slide were selected on Aperio Image Scope (v.12.4.0.5043) to manually measure individual hepatocyte surface area  and lamina propria area . A color adjustment filter was designed  using Aperio Image Scope to detect and count neutral , acid , and mixed  mucins from goblet cells . For each posterior intestine transverse section stained with alcian blue (AB) and periodic acid-Schiff (PAS), the total intestinal circumference was measured , and the length of each villus was measured by following the center part of the villus  and measured as the distance from the tip of the villus to the stratum compactum  for dietary Met and Cys were calculated to estimate the daily digestible feed intakes, forming independent variables, and were based on the equation reported by Cho et al. (1982), with the exception that yttrium oxide was used as the inert marker  and specific growth rate (SGR) were used as dependent variables to estimate the dietary, digestible, and daily digestible intake requirements for Met and Cys in juvenile GG. Various non-linear and linear regression models were applied to the data and initially screened via qualities of fit values , after which the most appropriately fitted models were further cross-validated via the Akaike information criterion (AIC) .The inflection point is calculated as follows:P < 0.05). The increase of dietary Met from 9.5 to 17.9 g/kg at a constant Cys level significantly increased the feed intake in GG until a peak was reached at 152.8 ± 1.0 g/fish (Table P < 0.05). The feed intake of GG was not affected by a four-fold increase in Tau, from 1.9 to 8.0 g/kg (Table The feed intake (FI) of GG is strongly dependent on the dietary Met content (Table FCR was not significantly affected by the dietary Met content (P > 0.05) nor by a four-fold increase of Tau at a constant level of dietary Met and Cys  of juvenile GG increased significantly (P < 0.05) for all doses of added Met supplementation compared to Diet 1 (Table P < 0.05). An incremental increase in dietary Met at a constant rate of dietary Cys significantly increased SGR (P < 0.05), peaking in performance at 15.8-g Met/kg diet, after which an increase of dietary Met to 21.5 g/kg led to a decrease in SGR  of juvenile GG decreased progressively with increasing Met content, with the lowest mean values recorded for GG fed diets with the highest Met content P < 0.0; Table 5GG Table . The hepP < 0.05). Low dietary Met contents of 9.5 g/kg (Diet 1) resulted in significantly lower plasma AST levels (34.4± 5.0 U/L) in comparison to the AST level of 71.3 ± 11.0 U/L of juvenile GG fed diets containing Met at 17.9 g/kg  (Table P < 0.05). The non-linear regression analysis confirms that an incremental increase in dietary Met at a constant rate of dietary Cys increased AST, peaking in activity at 18.9-g Met/kg diet  Table . The plaP < 0.05; Table P > 0.05; Table Intestinal villus length increased with increasing dietary methionine levels, peaking at 14.2-g Met/kg diet, above which it reduced Fig. j. The viP < 0.05; Fig. P < 0.05; Fig. P < 0.05), parallel to the density of acidic goblet cell mucin. The density of mixed goblet cell mucins were the lowest and highest in acidic goblet cell mucins when GG were fed Diet 3  and Met (149.21 g/mol). Other studies determining the dietary Met requirement of Epinephelus spp. have found lower or similar SAA requirements than our study. Juvenile hybrid grouper (E. fuscoguttatus♀ × E. lanceolatus♂) exhibited improved growth at a dietary Met level of 14.5 g/kg at a constant dietary Cys level of 6.9 g/kg (TSAA [Met + Cys] requirement = 21.4 g/kg)  . Yellowtail kingfish required a daily digestible Met intake of 0.55 and 0.60 g/kg body weight for optimized SGR and FCR, respectively, at a constant digestible Cys intake of 0.14 g/kg body weight. Furthermore, GG exhibited depressed growth and feed efficiency when the dietary Met level exceeded the optimum threshold. This growth depression concurs with results from other species, such as yellowtail kingfish (TSAA [Met + Cys] ≥ 23.4–26.1 g/kg)  (TSAA [Met + Cys] ≥ 12 g/kg) , increased Met intake resulted in a decrease in AST activity  is suggested to form a barrier difficult for pathogens to penetrate due to increased viscoelasticity and resisting breakdown by bacterial glycosidase activity, whereas neutral mucin (PAS+/stain magenta) promotes nutrient absorption and neutralizes digestive juices to protect the lamina epithelium from autodigestion , dietary Tau supplementation are also semi-essential and only required if dietary Met or sulfur amino acid level are deficient (Candebat et al. TSAA requirements are not met, Tau supplementation can benefit fish growth and improve feed conversion efficiency due to a provoked Tau requirement. Moreover, Tau can also spare a portion of TSAA requirements like Cys, essentially becoming a combined TSAA + tau requirement value. Overall, Tau can only be synthesized de novo from SAAs via a limited number of metabolic pathways and is thus best described as a semi-essential nutrient.While Met is universally essential in eukaryotic organisms, Tau is not essential in most organisms as it is metabolized by the unidirectional transsulfuration of its precursors Met and Cys (Brosnan and Brosnan The posterior intestinal wall thickness of GG from this study was not affected by the dietary Met treatment, but the intestinal stratum compactum was absent. The stratum compactum is associated with increased intestinal flexural rigidity Bucke  and is tTSAA [Met + Cys] requirements were met at 19.1 and 20.3 g/kg in juvenile GG. Moreover, juvenile GG exhibit intestinal macro- and micro-anatomical plasticity of the liver, AST activity, and posterior intestine in relation to different dietary Met levels. Marginal Met deficiencies appear to be compensated by longer intestinal villi to maximize nutrient absorption. In contrast, an insufficient dietary Met content resulted in a high liver-to-body size ratio, suggesting impaired liver homeostasis. Our study also found that supplemental Tau does not improve growth or FCR if sufficient dietary SAAs and a high digestibility of proteins are provided. These data facilitate the formulation of feeds specifically for GG and allow the inclusion of more diverse raw materials to reduce reliance on wild-caught fish toward more sustainable and cost-effective feeds. Findings from this study open directions to further investigate the role of Met and Tau on liver functions in GG, as the results from our study are size and culture specific, and the relevance should be considered.In synopsis, our results show that


A infection rate of 1.1% after HA with dual antibiotic-loaded bone cement was reported, compared to a 2.1% infection rate whilst using single antibiotic-loaded bone cement after five years (p = 0.098). The number required for treatment when using HA was 91. Conclusions: The use of dual antibiotic-loaded bone cement is increasingly used in arthroplasty procedures after femoral neck fractures. It demonstrates a reduction of PJI after HA and seems, therefore, to be a useful method for the prevention of infection, especially in patients with increased risk factors for PJI.Background: Antibiotic-loaded bone cement in arthroplasties is currently experiencing increased usage. Therefore, single and double antibiotic-loaded bone cements are commercially available and used in orthopedic surgery. The aim of this investigation was to compare the clinical use of single compared to dual antibiotic-loaded bone cement for implant fixation after femoral neck fracture. Further infection rates were to be compared in  arthroplasty for the treatment of femoral neck fracture for both treatment options. Methods: On the basis of the German Arthroplasty Registry (EPRD), all cases of femoral neck fracture treated with hemiarthroplasty (HA), or total hip arthroplasty (THA) with single and dual antibiotic-loaded bone cement, were included into the data analysis. The infection risk was compared using Kaplan-Meier estimates. Results: In total, 26,845 cases (HA 76.3%–THA: 23.7%) with femoral neck fracture were included. Within recent years, an increasing usage of dual antibiotic-loaded cement in Germany, with a current proportion of 7.30% in arthroplasty procedures for femoral neck fracture treatment, has been observed. In patients treated with HA, the proportion of dual antibiotic-loaded cement was 7.86%, while in those treated with THA, 5.46% of all prostheses were fixated with a two antibiotic component cement. For all arthroplasty procedures using single antibiotic-loaded bone cement after six months 1.8%, after one year 1.9%, and after five years 2.3%, of the cases failed due to periprosthetic joint infection (PJI), while in the same time period, in cases with dual antibiotic-loaded bone cement 1.5%, 1.5% and 1.5% suffered from infection ( Projections of intracapsular femoral neck fractures estimate up to 21.3 million fractures will occur annually, with a doubling of these totals occurring worldwide between 2025 and 2050 . Femoralp = 0.041) within one year after HA implantation [One major complication of arthroplasty is the development of a periprosthetic joint infection (PJI), which occurs in up to 3% of the performed  arthroplasties ,8. Besidantation . HoweverTherefore, the aim of the present investigation was (1) the detection of trends in used bone cements with antibiotics in a single or dual-loaded manner for HAs and THAs for the treatment of intracapsular femoral neck fractures since 2012. Additionally, (2) infection rates after cemented HAs and cemented THAs for intracapsular femoral neck fracture using single and dual-antibiotic loaded bone cement should be elucidated. In this investigation, overall 26,845 cases of arthroplasty treatment were included. Thereby, 20,487 (76.3%) of cemented HAs and 6358 (23.7%) THAs after intracapsular femoral neck fracture were analyzed. Anthropometric data was summarized in Within nine years since the start of the German Arthroplasty Register (EPRD) in 2012, for HAs and THAs a clear trend of increased usage of dual antibiotic-loaded bone cement has been reported. In HAs, the proportion of dual antibiotic-loaded bone cement raised from 1.15% in the second year of the register to 7.86% after nine years of the register. In cemented THAs the rate of dual antibiotic-loaded bone cement raised from 1.30% to 5.46% .p = 0.34). In single antibiotic-loaded bone cement the cumulative infection incidence was 1.3 % after one month, 1.8% after six months, and 2.3% after five years. In the same time period for arthroplasties with dual antibiotic-loaded cement, infection rates of 0.7%, 1.5%, and 1.5% were reported. The number needed for the prevention of just one infection was 125 after 5 years . The proportion of infection raised from 1.8% in single antibiotic-loaded cement, and 1.1% in dual antibiotic-loaded cement after six months, to 1.9% and 1.1%, respectively, after one year, and 2.1% and 1.1%, respectively, after five years . After six months, in the subpopulation of single antibiotic-loaded bone cement, a proportion of 1.8% infections was reported, while in dual antibiotic-loaded bone cement a rate of 3.8% of infections were documented. One year after implantation, 1.9% were registered in single antibiotic-loaded, and 3.8% in the dual antibiotic-loaded bone cement, whereas after five years 2.7% and 3.8% were reported, respectively. The number needed for the prevention of just one infection was 91 in HA after 5 years  arthroplasty registered in the German Arthroplasty Register (EPRD), a trend with an increase of 7.3% within the last nine years was observed for the use of dual antibiotic-loaded bone cement. While no statistically significant differences with regards to rate of infection were reported for the usage of single antibiotic-loaded and dual antibiotic-loaded bone cement, the proportion of infection was lower for the treatment with dual antibiotic cement. The number needed to treat in order to prevent one PJI, using dual antibiotic-loaded bone cement for HA, was 91.Since the start of the German Arthroplasty Register a clear increase in the use of dual antibiotic-loaded bone cement was detected within the period of 2013 until 2022. For HA and THA, over 7% of prostheses were implanted using dual antibiotic-loaded bone cement. The rate of dual antibiotic-loaded bone cement was even higher in HA, with a figure of 7.86%. Recent published studies reporting an improved effect on surgical site infection prevention and increased marketing activities of companies might be the reason for this observed trend in recent years ,15,16. FA reduction in the rate of PJI was detected across the five-year study period for the use of dual antibiotic-loaded bone cement compared to the single antibiotic-loaded bone cement for HA for the treatment of intracapsular femoral neck fractures. After five years, the difference in infection rate in HA was 1.0%. For all arthroplasties the number needed to treat was calculated with 125 cases for the prevention of one PJI; in HA, the number needed to treat was 91. Because of the burden and long-term consequences of PJI the prevention of infection is extraordinarily relevant. Due to the small number of THA cases in which dual antibiotic-loaded bone cement was used, calculated differences, infection rates and, especially the number needed to treat in this group should be regarded with caution. Higher numbers acquired in the coming years will surely draw a clearer picture for this special patient cohort.p = 0.003) [p = 0.035) with a mean assumption of cost savings of approximately USD 1367 for the inhouse treatment by prevention of PJI [p = 0.009) [In HA, a greater benefit is expected for dual antibiotic-loaded cement compared to THA, due to the more vulnerable patient population. The indication for implantation of an HA occurs not only because of advanced age and having a shortened life expectancy (<5 years), but also as a result of the presence of relevant comorbidities. In particular, this patient population is at risk of developing PJI ,19. Prev= 0.003) . For the= 0.003) . Furthern of PJI . Compare= 0.009) . This pr= 0.009) . p = 0.469) [Concerns about the use of antibiotic-loaded bone cement exist, particularly with regards to the development of antibiotic resistance and toxic properties. The application of antibiotic-loaded bone cement provides local high doses of antibiotics in the affected joint, and works complementary to the systematic antibiotic prophylaxis for the reduction of PJI and the treatment of potentially resistant bacteria, as well as the establishment of biofilms ,22. A co= 0.469) . These f= 0.469) . Infecti= 0.469) . Taking = 0.469) ,24,25. The use of bone cement in antibiotic application is industrially provided and FDA-approved. Single loaded cements thereby mostly consist of gentamicin (0.5 g or 1 g) or tobramycin (1 g), while for dual antibiotic-loaded bone cements, gentamycin is combined with clindamycin (1 g gentamicin + 1 g clindamycin) or with vancomycin (0.5 g gentamicin + 2 g vancomycin) ,21. GentThe present registry data confirm the risk reduction of PJI after HA for femoral neck fracture according to the first results of clinical studies investigating this issue. The present data indicate that in patients with risk factors for the development of PJI dual antibiotic-loaded bone cements seem beneficial . TherefoBesides the multiple advantages of this register study, some limitations occur within the type of design and methods. One major limitation is the case number of dual antibiotic-loaded bone cement in THAs. These low numbers do not allow for a reliable conclusion for THA alone, in particular, with regards to the infection rate and the number needed to treat. Due to the unmatched patient collective between HA and THA, and differences between patient anthropometry, a comparison with regards to the PJI rate should only be made with caution because of the use of a different anthropometry. However, the present investigation offers some first insights into an issue with high clinical and scientific relevance, which led the authors to report the present findings. Furthermore, several questions such as the optimal patient population for dual antibiotic-loaded bone cement after arthroplasty, or the evaluation of local side effects cannot yet be answered based on the current available dataset. The German Arthroplasty Registry (EPRD) registers implantations of prosthesis in collaboration with the statutory health insurance funds in Germany , the German Medical Technology Association (BVMed), and several participating hospitals since 2012. With more than 1.6 million procedures documented, the register covered, on a voluntary basis in the year 2020, approximately 70% of all hip and knee arthroplasties performed in Germany . ApproxiFor the classification and identification of diagnoses and procedures, the German versions of the International Classification of Procedures in Medicine (ICPM), the “Operation and Procedure Code” (OPS) 301 system, and the 10th International Classification of Diseases (ICD-10) were used. All patients with cemented HA and THA, after intracapsular femoral neck fracture as a main diagnosis (ICD-10: S72.0-), between 2013 and 2022 were included in the present analysis of the EPRD. Patients were divided into subpopulations with single antibiotic-loaded bone cement and dual antibiotic-loaded bone cement for the fixation of THA or HA. THA with hybrid cemented components were also part of the study population. All patients with a cemented fixation of components received antibiotic-loaded bone cement. Through analysis of the used bone cement, a statement regarding single or dual antibiotic-loaded bone cement was obtained . The infThe data were analyzed to determine infection rates for cemented hemiarthroplasties (HA) and total hip arthroplasties (THA) after femoral neck fractures were treated with single and dual antibiotic-loaded bone cement in Germany. The statistical program R  was used to perform the statistical analysis. For statistical analysis, Kaplan-Meier estimates were calculated, log-rank tests were performed, and the number needed to treat (NNT) were calculated for the data. Categorical variables are presented in the number of observations and frequency, continuous variables in mean and standard deviation. The significance level was set at alpha = 0.05.The use of dual antibiotic-loaded bone cement in HA for the treatment of intracapsular femoral neck fractures demonstrated a reduction in the infection rate compared to single antibiotic-loaded cement. The observed reduction of infection rate and no evidenced side effects after the local use of antibiotic-loaded bone cement reported in the literature advocate the use of dual antibiotic-loaded bone cement, especially in patients with an increased risk of PJI after partial arthroplasty procedures for treatment of femoral neck fractures.