There is currently no evidence that the intervertebral discs (IVDs) can respond positively to exercise in humans. Some authors have argued that IVD metabolism in humans is too slow to respond anabolically to exercise within the human lifespan. Here we show that chronic running exercise in men and women is associated with better IVD composition (hydration and proteoglycan content) and with IVD hypertrophy. Via quantitative assessment of physical activity we further find that accelerations at fast walking and slow running (2 m/s), but not high-impact tasks, lower intensity walking or static positions, correlated to positive IVD characteristics. These findings represent the first evidence in humans that exercise can be beneficial for the IVD and provide support for the notion that specific exercise protocols may improve IVD material properties in the spine. We anticipate that our findings will be a starting point to better define exercise protocols and physical activity profiles for IVD anabolism in humans.
Currently, massive multiple input multiple output (MIMO) is one of the most promising wireless transmission technologies for 5G. Massive MIMO requires handling with largescale matrix computation, especially for matrix inversion. In this paper, we find that matrix inversion based on Newton iteration (NI) is suitable for data detection in massive MIMO system. In contrast with recently proposed polynomial expansion (PE) method for matrix inversion, we analyse both the algorithm complexity and precision in detail, and propose a diagonal band Newton iteration (DBNI) method which is an approximate method for NI. Compared with PE method, DBNI can obtain higher precision and approximately equal complexity, and we give an explanation of how to select the band width of DBNI.
We present an industrial tunnel oxide passivated contacts (i‐TOPCon) bifacial crystalline silicon (c‐Si) solar cell based on large‐area n‐type substrate. The interfacial thin SiO2 is thermally growth and in situ capped by an intrinsic poly‐Si layer deposited by low‐pressure chemical vapor deposition (LPCVD). The intrinsic poly‐Si layer is doped in an industrial POCl3 diffusion furnace to form the n+ poly‐Si at the rear, which shows an excellent surface passivation characteristics with J0 = 2.6 fA/cm2 when passivated by a SiNx:H layer deposited by plasma‐enhanced chemical vapor deposition (PECVD). With an industrial fabrication process, the cells are manufactured with screen‐printed front and rear metallization, using large‐area 6‐in. n‐type Czochralski (Cz) Si wafers. We demonstrate an average front‐side efficiency greater than 23% and an open‐circuit voltage Voc greater than 700 mV. These results are based on more than 20 000 pieces of cells from mass production on a single day, in an old conventional multicrystalline silicon (mc‐Si) Al‐back surface field (BSF) cell workshop, which has been upgraded to i‐TOPCon process. The best cell efficiency reaches 23.57%, as independently confirmed by Fraunhofer CalLab. A median module power greater than 345 W and a best module power greater than 355 W are demonstrated with double‐glass bifacial i‐TOPCon modules consisting of 120 pieces of half‐cut 161.7 mm pseudosquare i‐TOPCon cells with nine busbars.
Background:Injury to the distal musculotendinous T junction (DMTJ) of the biceps femoris is a distinct clinical entity that behaves differently from other hamstring injuries due to its complex, multicomponent anatomy and dual innervation. Injury in this region demonstrates a particularly high rate of recurrence, even with prolonged rehabilitation times.Purpose:To describe the anatomy of the DMTJ of the biceps femoris and analyze the injury patterns seen on magnetic resonance imaging (MRI) to aid prognosis and rehabilitation and minimize the risk of recurrence.Study Design:Cross-sectional study; Level of evidence, 3.Methods:Acute injury to the DMTJ of the biceps femoris was identified in 106 MRI examinations from 55 patients at a single institution. Each injury was classified as involving the long head, the short head, or both components of the DMTJ, with each component individually graded. Injuries were classified as recurrent if there was a previous MRI demonstrating an acute injury to the DMTJ or if there was scarring present at the site of an acute injury.Results:Of the 106 acute injuries to the DMTJ of the biceps femoris, isolated injury to the long head component was the most common (51%), with both components involved in [round 42.5% to 43%] of cases. Isolated injury to the short head component accounted for 7% of cases. The recurrence rate for reinjury to the DMTJ was 54% in this series. The date of prior injury was known in 45 of 57 recurrent cases, with 34 of these reoccurring within 3 months (76%) and 40 reoccurring within 12 months (89%). The recurrent injury was of a higher grade than the prior injury in 22 of 44 instances (50%), the same grade in 16 instances (36%), and a lower grade in 6 instances (14%). Thus, 86% of recurrent injuries were of the same or higher grade than prior injury.Conclusion:These results suggest that high-risk muscle injuries, such as that to the DMTJ of the biceps femoris, should be evaluated using MRI to determine the structural components involved and to assess the extent and severity of injury.
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