A feeding trial was conducted to quantify the effects of phytase at levels of 0, 500, 1,000, 2,000, 4,000, and 8,000 units (U) per kg diet on utilization of dietary protein and minerals by fingerling (12 g) channel catfish Ictalurus punctatus fed an all‐plant‐protein diet composed of soybean meal, corn, and wheat middlings. The effects of phytase on dephosphorylation of phytic acid (phytate) in the alimentary tract of catfish also were determined. After 14 wk, mean weight gains (30.2–43.9 g/fish), feed conversion ratios (2.27–2.40 g feed consumed/g weight gain), protein efficiency ratios (1.47–1.61 g weight gaid/g protein consumed), and dietary protein retentions (23.8–26.7%) did not differ significantly (P > 0.05) among treatment groups. A digestibility trial conducted after the feeding trial showed no difference (P > 0.05) in mean digestibility of diet dry matter (49.0–58.3%) or crude protein (85.4‐88.5%) among treatment groups. Concentrations of ash (46.7–48.6%), calcium (Ca, 17.9–18.5%), phosphorus (P, 9.1–9.5%), and manganese (Mn, 65.5–74.1 mg/kg) were significantly higher (P ≤ 0.05) in bone of fish fed ≥ 500 U/kg than in bone of fish fed 0 U/kg (ash, 43.5%; Ca, 16.4%; P, 8.4%; and Mn, 49.0 ma/kg), but concentrations of these minerals did not differ (P > 0.05) in bone of fish fed ≥ 500 Uk/g. The magnesium (Mg) content of bone did not differ (P > 0.05) between fish fed 0 U/kg (0.29%) or 500 U/kg (0.34%), but was significantly lower in fish fed 0 U/kg than in fish fed ≥ 1,000 U/kg (0.35–37%). Bone Mg levels did not differ (P > 0.05) among fish fed ≥ 500 U/kg. The amount of zinc (Zn) in bone of fish fed 8,000 U/kg (153.3 mg/kg) was significantly higher than that in fish fed 0 U/kg (115.7 mg/kg) or 500 U/kg (130.3 mg/ kg), but did not differ from Zn levels in bone of fish fed 1,000–4,000 U/kg (134.5–135.8 mg/ kg). Dephosphorylation of phytate occurred primarily in the stomach within 2–8 h after diet ingestion, depending on the level of phytase supplementation. Initial levels of total phytate in the diet decreased 32–94% in stomach contents of fish fed l,000–8,000 U/kg within 2 h after feeding. Eight hours after feeding, stomach contents of fish fed ≥ 1,000 U/kg contained less than 6% of initial total dietary phytate. Stomach contents of fish fed 500 U/kg retained 92% of initial total dietary phytate 2 h after feeding and 15% of total dietary phytate 8 h after feeding. Results of this study indicate that phytase supplementation at levels up to 8,000 U/kg diet did not increase weight gain or improve dietary protein utilization of channel catfish fed an all‐plant‐protein diet. Addition of phytase at a level of 1,000 U/kg diet was sufficient to significantly increase the Ca, P, Mg, and Mn content of bone, relative to fish fed an unsupplemented diet, and significantly decrease the quantity of total phytate in feces. A phytase level of 8,000 U/kg diet significantly increased the bioavailability of naturally occurring Zn in feed ingredients and increased the rate of phytate dephosphorylation in the stomach, co...

Background Knee osteoarthritis (OA) is a leading cause of global disability. According to current guidelines, exercise is the most recommended and important non-surgical treatment for knee OA. However, the best type of exercise for this condition remains unclear. Evidence has shown that traditional Chinese exercises may be more effective. Therefore, the current prospective, two-armed, single-center randomized controlled trial (RCT) aimed to identify an effective physiotherapy for knee OA. Methods/design In total, 114 patients with painful knee OA will be recruited from the orthopedic outpatient department of Shanghai Jiao Tong University Affiliated Sixth People’s Hospital. To compare the therapeutic effect of two different home-based exercise programs, the participants will be randomly assigned into the experimental group (leg swing exercise) or the control group (quadriceps strengthening exercise). Each participant in both groups will be required to attend five individual sessions with a physiotherapist who will teach the exercise program and monitor progress. Participants will be instructed to perform the exercises at home every day for 12 weeks. Clinical outcomes will be assessed at baseline and 12 and 24 weeks after starting the intervention. The primary outcomes are average overall knee pain and physical function in daily life. The secondary outcomes include other measures of knee pain, physical function, patient-perceived satisfactory improvement, health-related quality of life, physical activity and performance, muscle strength of the lower limb, and adherence. Discussion This study will provide more evidence on the effects of traditional Chinese exercise on improving physical function and relieving joint pain among patients with knee OA. If proven effective, leg swing exercise can be used as a non-surgical treatment for knee OA in the future. Trial registration Chinese Clinical Trial Registry ChiCTR2000039005. Registered on 13 October 2020.

Tidal flat system is composed of multiple sub-scale geomorphological units. We found a new mesoscale geomorphological unit on sand-mud mixed intertidal zone along China coast, which was defined as hummocky patches. Hummock patches are most developed in middle tidal flat, with horizontal magnitude of 10–20 m and vertical magnitude of ∼15 cm. Hummocky patches significantly influence local sediment transport, thus affect morphological evolution of tidal flats. In order to understand the formation and development mechanisms of hummocky patches, we collected hydrodynamics, topography, sediment properties, and substrate erosion thresholds data through an in-situ field observation covering a spring-neap tidal cycle over an accretional intertidal flat in Jiangsu, China. We found that sediment characteristics including sorting coefficient (σ: measuring the uniformity of sediment particles) and silt/clay/organic matter/water content are essentially different between hummocky patches and nearby seabed, which leads to spatially varied substrate erosion resistance. The measured erosion thresholds for patches are two times higher comparing to surrounding seabed sediment, which provides foundation for the formation of hummocky patches. Under the impact of periodical tidal currents and waves, surrounding seabed experiences considerably more erosion than patch area, which finally develops to hummocky patches. Therefore, hydrodynamic forces drive the formation and development of patches. The erosion resistance of patches decreases vertically from seabed surface to sublayer, causing initial erosion in the lower sublayer, followed by a mass collapse of the seabed surface layer. Hummocky patches are commonly found in middle tidal zone and their sizes decrease to the shore as tidal currents and waves attenuate with shoreward propagation. Hummocky patches have distinct seasonal variations, which only appear in summer and autumn when wind waves are comparatively lower than winter and spring. We infer the reason is that the strong hydrodynamics caused by winter storms cause larger bottom shear stress than the erosion threshold of hummocky patches, leading to destruction of hummocky patches and a smooth tidal flat surface. This study shed new insight on the knowledge of mesoscale geomorphological units and their formation and development in intertidal flats, which provides crucial information for developing more realistic tidal flat sediment transport and morphological models.

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Background Knee osteoarthritis (OA) is a leading cause of global disability. According to guidelines, thus far, exercise is the most recommended and important non-surgical treatment for knee OA. However, the best type of exercise for this condition remains unclear. There is evidence showing that traditional Chinese exercises may be more effective. Therefore, the current prospective, two-armed, single-center randomized controlled trial (RCT) aimed to identify an effective physiotherapy for knee OA. Methods/design: In total, 128 patients with painful knee OA will be recruited from the orthopaedic outpatient department of Shanghai Jiao Tong University Affiliated Sixth People’s Hospital. To compare the therapeutic effect of two different home-based exercise programs, the participants will be randomly assigned into the experimental group (leg swing exercise) or the control group (quadriceps strengthening exercise). Each participant in both groups will be required to attend five individual sessions with a physiotherapist who will teach the exercise program and monitor progress. Participants will be instructed to perform the exercises at home every day for 12 weeks. Clinical outcomes will be assessed at baseline and 12 and 24 weeks after starting the intervention. The primary outcomes are average overall knee pain and physical function in daily life. The secondary outcomes include other measures of knee pain, physical function, patient-perceived satisfactory improvement, health-related quality of life, physical activity and performance, muscle strength of the lower limb, and adherence. Discussion This study will provide more evidence on the effects of traditional Chinese exercise on improving physical function and relieving joint pain among patients with knee OA. If proven effective, leg swing exercise can be used as a non-surgical treatment for knee OA in the future. Trial registration: Chinese Clinical Trial Registry reference: ChiCTR2000039005, registered 13/10/2020. http://www.chictr.org.cn/showproj.aspx?proj=62497