Case report: A novel 10.8-kb deletion identified in the β-globin gene through the long-read sequencing technology in a Chinese family with abnormal hemoglobin testing results

BackgroundThalassemia is a common inherited hemoglobin disorder caused by a deficiency of one or more globin subunits. Substitution variants and deletions in the HBB gene are the major causes of β-thalassemia, of which large fragment deletions are rare and difficult to be detected by conventional polymerase chain reaction (PCR)-based methods.Case reportIn this study, we reported a 26-year-old Han Chinese man, whose routine blood parameters were found to be abnormal. Hemoglobin testing was performed on the proband and his family members, of whom only the proband's mother had normal parameters. The comprehensive analysis of thalassemia alleles (CATSA, a long-read sequencing-based approach) was performed to identify the causative variants. We finally found a novel 10.8-kb deletion including the β-globin (HBB) gene (Chr11:5216601-5227407, GRch38/hg38) of the proband and his father and brother, which were consistent with their hemoglobin testing results. The copy number and exact breakpoints of the deletion were confirmed by multiplex ligation-dependent probe amplification (MLPA) and gap-polymerase chain reaction (Gap-PCR) as well as Sanger sequencing, respectively.ConclusionWith this novel large deletion found in the HBB gene in China, we expand the genotype spectrum of β-thalassemia and show the advantages of long-read sequencing (LRS) for comprehensive and precise detection of thalassemia variants

Design and experimental research of an improved stick–slip type piezo-driven linear actuator

A piezo-driven linear actuator based on the improved stick–slip principle is developed in this article. With the help of two piezo-stacks and flexure hinges, the preload force can be changed, so the designed actuator can realize relatively large linear ranges and large output force. The designed actuator mainly consists of the mover, the stator, two piezo-stacks, an adjusting stage and the base. The working principle and theoretical analysis are described. A prototype actuator was fabricated and a series of experiments were carried out to investigate the work characteristics of it. Experimental results indicate that the maximum speed is about 3.086 mm/s and the maximum output force is 0.98 N. They are both improved compared with the traditional stick–slip motion. Experimental results confirm that the proposed actuator can realize large output force relatively and different motion speeds with high accuracy under different driving voltages and frequencies

Molecular dynamics simulation of self-rotation effects on ultra-precision polishing of single-crystal copper

Understanding the behaviors of the material removal mechanism of ultra-precision polishing process has been a critical issue of generating well-formed surface. In order to make clear the abrasive self-rotation effects on material removal at the atomic level, a three-dimensional molecular dynamics (MD) model is conducted to study the mechanics of ultra-precision polishing on single-crystal copper with a diamond abrasive and the effects of abrasive self-rotation velocity and direction. Morse potential energy function and EAM potential energy function are applied to model the copper/diamond and copper/copper interactions, respectively. The simulation results show that the deformation mechanism of single-crystal copper is due to the formation and movement of dislocations in the specimen. In addition, with the increasing of abrasive self-rotation velocity, the deformation mechanism falls from cutting to plowing regimes. The abrasive self-rotation velocity and direction have effects on the morphology and quality of the specimen surface, distribution and evolution of defects under the surface of the specimen. Also, the interatomic force between abrasive and specimen is studied to account for the effects of different polishing conditions

Synergistic Effect of Pressurization Rate and β-Form Nucleating Agent on the Multi-Phase Crystallization of iPP

Using a homemade pressure device, we explored the synergistic effect of pressurization rate and β-form nucleating agent (β-NA) on the crystallization of an isotactic polypropylene (iPP) melt. The obtained samples were characterized by combining small angle X-ray scattering and synchrotron wide angle X-ray diffraction. It was found that the synergistic application of pressurization and β-NA enables the preparation of a unique multi-phase crystallization of iPP, including β-, γ- and/or mesomorphic phases. Pressurization rate plays a crucial role on the formation of different crystal phases. As the pressurization rate increases in a narrow range between 0.6–1.9 MPa/s, a significant competitive formation between β- and γ-iPP was detected, and their relative crystallinity are likely to be determined by the growth of the crystal. When the pressurization rate increases further, both β- and γ-iPP contents gradually decrease, and the mesophase begins to emerge once it exceeds 15.0 MPa/s, then mesomorphic, β- and γ- iPP coexist with each other. Moreover, with different β-NA contents, the best pressurization rate for β-iPP growth is the same as 1.9 MPa/s, while more β-NA just promotes the content of β-iPP under the rates lower than 1.9 MPa/s. In addition to inducing the formation of β-iPP, it shows that β-NA can also significantly promote the formation of γ-iPP in a wide pressurization rate range between 3.8 to 75 MPa/s. These results were elucidated by combining classical nucleation theory and the growth theory of different crystalline phases, and a theoretical model of the pressurization-induced crystallization is established, providing insight into understanding the multi-phase structure development of iPP

Global risk factor analysis of myopia onset in children: A systematic review and meta-analysis.

IntroductionThis work aimed to comprehensively assess the risk factors affecting myopia in children to develop more effective prevention and treatment strategies. To this end, data from database were employed to assess the relationship between the incidence of myopia and its risk factors.MethodsWe searched eight databases online in June 2022. Cohort studies were included that measured the connection between risk factors and myopia. Eligibility was not restricted by language. The Newcastle-Ottawa Scale (NOS) was used to measure the risk of bias and conducted GRADE evaluation to determine the certainty of evidence. Potential risk factors with positive or negative results were seen. Inplasy Registration: https://inplasy.com/inplasy-2022-4-0109/.ResultsEvidence that risk factors for myopia are mixed, comprising both positive (20) and null (17) findings. In 19 cohort studies on 3578 children, girls were more likely to develop myopia (RR: 1.28 [1.22-1.35]). Myopia can occur at any age, from early childhood to late adulthood. Children whose parents had myopia were more likely to develop myopia. Longer outdoor activities time (RR: 0.97 [0.95-0.98]) and less near-work time (RR: 1.05 [1.02-1.07]) appeared to be significantly decrease the incidence of myopia. Children with lower SE, longer AL, a lower magnitude of positive relative accommodation, worse presenting visual acuity, deeper anterior chamber, and thinner crystalline lens may be related to myopia onset. The burden of myopia in underprivileged countries is higher than in developed countries (RR: 5.28 [2.06-13.48]). The quality of evidence for the evaluated factors was moderate to low or very low.ConclusionsGenetic factors, environmental factors (such as excessive use of electronic products, and poor study habits) and lifestyle factors (such as lack of outdoor activities, poor nutrition, etc.) are the main risk factors for myopia in children. Myopia prevention strategies should be designed based on environmental factors, gender, parental myopia and eye indicators in order to explore a lifestyle that is more conducive to the eye health of children

3094904.pdf

Supplementary Informatio

Supplementary Information.docx

Supplemental document<br