Forensic Identification and Evaluation of 25 Obstetric Brachial Plexus Palsy Medical Damage Cases.

OBJECTIVES: To analyze the high risk factors of obstetric brachial plexus palsy (OBPP), and to explore how to evaluate the relationship between fault medical behavior and OBPP in the process of medical damage forensic identification. METHODS: A retrospective analysis was carried out on 25 cases of medical damage liability disputes related to OBPP from 2017 to 2021 in Beijing Fayuan Judicial Science Evidence Appraisal Center. The shortcomings of hospitals in birth weight assessment, delivery mode selection, labor process observation and shoulder dystocia management, and the causal relationship between them and the damage consequences of the children were summarized. RESULTS: Fault medical behavior was assessed as the primary cause in 2 cases, equal cause in 10 cases, secondary cause in 8 cases, minor cause in 1 case, no causal relationship in 1 case, and unclear causal force in 3 cases. CONCLUSIONS: In the process of forensic identification of OBPP, whether medical behaviors fulfill diagnosis and treatment obligations should be objectively analyzed from the aspects of prenatal evaluation, delivery mode notification, standardized use of oxytocin, standard operation of shoulder dystocia, etc. Meanwhile, it is necessary to fully consider the objective risk of different risk factors and the difficulty of injury prevention, and comprehensively evaluate the causal force of fault medical behavior in the damage consequences.

Effect of ultrasonic surface deep rolling combined with oxygen boost diffusion treatment on fatigue properties of pure titanium.

Ultrasonic surface deep rolling (USDR), oxygen boost diffusion (OBD), and their combination (USDR-OBD) were all used to improve the surface hardening of pure titanium. The microstructure, microhardness, and fatigue life of pure titanium treated by USDR, OBD, and USDR-OBD methods were analyzed. USDR treatment induced a severe deformation area, while OBD treatment produced a brittle oxygen diffusion zone. The USDR-OBD treated samples approached the highest hardness in comparison with other treated samples. The fatigue lives of USDR treated samples were improved, which was due to the high compressive residual stress and refined grains. However, the fatigue lives of both OBD treated samples and USDR-OBD treated samples were decreased due to premature crack initiation and rapid propagation in the oxygen diffusion zone. Finally, the fatigue fracture mechanisms of different samples were proposed.

Identification of the defense-related gene VdWRKY53 from the wild grapevine Vitis davidii using RNA sequencing and ectopic expression analysis in Arabidopsis.

BACKGROUND: Grapevine is an important fruit crop grown worldwide, and its cultivars are mostly derived from the European species Vitis vinifera, which has genes for high fruit quality and adaptation to a wide variety of climatic conditions. Disease resistance varies substantially across grapevine species; however, the molecular mechanisms underlying such variation remain uncharacterized. RESULTS: The anatomical structure and disease symptoms of grapevine leaves were analyzed for two grapevine species, and the critical period of resistance of grapevine to pathogenic bacteria was determined to be 12 h post inoculation (hpi). Differentially expressed genes (DEGs) were identified from transcriptome analysis of leaf samples obtained at 12 and 36 hpi, and the transcripts in four pathways (cell wall genes, LRR receptor-like genes, WRKY genes, and pathogenesis-related (PR) genes) were classified into four co-expression groups by using weighted correlation network analysis (WGCNA). The gene VdWRKY53, showing the highest transcript level, was introduced into Arabidopsis plants by using a vector containing the CaMV35S promoter. These procedures allowed identifying the key genes contributing to differences in disease resistance between a strongly resistant accession of a wild grapevine species Vitis davidii (VID) and a susceptible cultivar of V. vinifera, 'Manicure Finger' (VIV). Vitis davidii, but not VIV, showed a typical hypersensitive response after infection with a fungal pathogen (Coniella diplodiella) causing white rot disease. Further, 20 defense-related genes were identified, and their differential expression between the two grapevine species was confirmed using quantitative real-time PCR analysis. VdWRKY53, showing the highest transcript level, was selected for functional analysis and therefore over-expressed in Arabidopsis under the control of the CaMV35S promoter. The transgenic plants showed enhanced resistance to C. diplodiella and to two other pathogens, Pseudomonas syringae pv. tomato DC3000 and Golovinomyces cichoracearum. CONCLUSION: The consistency of the results in VID and transgenic Arabidopsis indicated that VdWRKY53 might be involved in the activation of defense-related genes that enhance the resistance of these plants to pathogens. Thus, the over-expression of VdWRKY53 in transgenic grapevines might improve their resistance to pathogens.

Micro-deformation evolutions of the constituent phases in duplex stainless steel during cyclic nanoindentation.

Cyclic elastoplastic deformation behaviors of austenite phase and ferrite phase in a duplex stainless steel were investigate by load-controlled cyclic nanoindentation with a Berkovich indenter. During the tests, the maximum penetration depth per cycle increased rapidly with cycle number at transient state, and reached stable at quasi-steady state. Plastic dissipated energy was quantitatively proved to be the driving force for the propagation of deformation zones during cyclic nanoindentation tests. Transmission electron microscopy combined with FIB was used to reveal the deformation mechanisms of both phases underneath indents with cycles. After quasi-static single loading, nucleation and concentration of dislocations were observed in both austenite phase and ferrite phase under the indenter. After cyclic loading, dislocations propagated to further regions in both phases. Besides, slip bands were generated within single nanoindentation and propagated during the subsequent cyclic nanoindentation. The sizes of the deformation regions for both phases under the indents after cyclic indentation observed by TEM were consistent with those calculated by the expansion model of spherical cavity.

A modified analysis for thermal-mechanical properties of staggered structure in biomimetic materials.

The thermal-mechanical stress distributions and equivalent coefficient of thermal expansion (CTE) of the staggered arrangement of mineral platelets wrapped by soft matrix are analyzed, which exist in numerous natural biological and biomimetic materials. Two analytical models, 'Stress model' and 'Displacement model', were established from the ways of stress and displacement solution based on the modification of classical shear-lag model. Complementary finite element analysis (FEA) was used to verify the analytical models. Results reveal that, compared to 'Displacement model', 'Stress model' gives a better prediction of the stress distributions within the staggered structure referring to FEA. The equivalent CTE predicted by both models reach constant as the aspect ratio and volume fraction of platelets exceeding the critical values. Nevertheless, the relative error between the results from different models increases with the increase of the ratio of overlap to length of platelets. These provide a benchmark to the optimum design of micro/nano-structure in bio-inspired materials suffering to temperature fluctuation and applied loading.

Anisotropic fatigue behavior of human enamel characterized by multi-cycling nanoindentation.

Single- and multi-cycling nanoindentations were performed on occlusal surface and axial section of human enamel rod using Berkovich indenter. Deviation of load-depth curve under multi-cycle from single-cycle could indicate the anisotropic fatigue damage during repeated indentations. On occlusal surface, fatigue damage is ascribed to the partial interface debonding between crystals and protein and incomplete refolding of domain bonds of protein molecules. While on the axial section, additional damages, i.e., fracture of crystals and debonding at the end of crystals are supposed to be dominant.