Femtosecond Laser-Induced Phase Transformation on Single-Crystal 6H-SiC.

Silicon carbide (SiC) is widely used in many research fields because of its excellent properties. The femtosecond laser has been proven to be an effective method for achieving high-quality and high-efficiency SiC micromachining. In this article, the ablation mechanism irradiated on different surfaces of 6H-SiC by a single pulse under different energies was investigated. The changes in material elements and the geometric spatial distribution of the ablation pit were analyzed using micro-Raman spectroscopy, Energy Dispersive Spectrum (EDS), and an optical microscope, respectively. Moreover, the thresholds for structural transformation and modification zones of 6H-SiC on different surfaces were calculated based on the diameter of the ablation pits created by a femtosecond laser at different single-pulse energies. Experimental results show that the transformation thresholds of the Si surface and the C surface are 5.60 J/cm2 and 6.40 J/cm2, corresponding to the modification thresholds of 2.26 J/cm2 and 2.42 J/cm2, respectively. The Raman and EDS results reveal that there are no phase transformations or material changes on different surfaces of 6H-SiC at low energy, however, decomposition and oxidation occur and then accumulate into dense new phase material under high-energy laser irradiation. We found that the distribution of structural phase transformation is uneven from the center of the spot to the edge. The content of this research reveals the internal evolution mechanism of high-quality laser processing of hard material 6H-SiC. We expect that this research will contribute to the further development of SiC-based MEMS devices.

Distress, support and psychological resilience of psychiatric nurses as second victims after violence: A cross-sectional study.

AIM: The aim is to explore the impact of violence and psychological resilience on psychiatric nurses as second victims. BACKGROUND: Workplace violence is a public health concern, seriously influencing medical staff's physical and mental health. However, few pieces of research have concentrated on psychiatric nurses as second victims. METHOD: The socio-demographic data, violence-related data, psychological resilience scale, the Chinese version of the Second Victim Experience and Support Tool were applied to conduct a cross-sectional survey on nurses from psychiatric hospitals. The multiple linear regression model identified significant variables associated with violence-related injury and resilience. RESULTS: A total of 683 nurses completed the survey, of whom 88.3% were women. The average scores of the second victims' experience and support, support and distress were 3.45 ± 0.43, 3.71 ± 0.57 and 3.19 ± 0.67, respectively. Physical violence, psychological violence, psychological influence and nursing work environment were positively correlated with the experience and support of the second victims, and innocuous violence was a negative factor, which explains 20.6% of the variation. Moreover, physical injury, nursing work environment, resilience restructuring, physical violence, psychological violence, psychological impact and disagreement about the existence of violence explained 14.8% of the distress. The innocuous violence, psychological violence and nursing work environment explained 46.2% of the support. CONCLUSIONS: Our findings suggest that nurses who are second victims after the violence mainly suffer from severe psychological distress and receive the least support for the same. IMPLICATION FOR NURSING MANAGEMENT: The study provides clues to help nursing managers' emphasis on the distress and support of second victims and provides targeted intervention based on the relevant factors and these results. The article is a cross-sectional study of psychiatric nurses, which has been approved by the ethics committee of the hospital before the survey. All the nurses who participated in the survey have been informed and agreed.

A model for predicting ground reaction force and energetics of human locomotion with an elastically suspended backpack.

This paper presents an actuated spring-loaded inverted pendulum model with a vertically constrained suspended load mass to predict the vertical GRF and energetics of walking and running. Experiments were performed to validate the model prediction accuracy of vertical GRF. The average correlation coefficient was greater than 0.97 during walking and 0.98 during running. The model's predictions of energy cost reduction were compared with experimental data from the literature, and the difference between the experimental and predicted results was less than 7%. The predicted results of characteristic forces and energy cost under different suspension stiffness and damping conditions showed a tradeoff when selecting the suspension parameters of elastically suspended backpacks.

The impact of the second victim's experience and support on the career success of psychiatric nurses: The mediating effect of psychological resilience.

AIMS: We explored the mediating role of psychological resilience in the experience and support of psychiatric nurses as the second victims and their career success. BACKGROUND: Psychiatric nurses, as the primary victims of workplace violence, experience physical and psychological distress, which leads to high resignation rate and job burnout. However, not much is known about the mediating role of psychological resilience between the second victims of workplace violence and their career success. METHODS: A cross-sectional study was conducted among 683 psychiatric nurses. The participants were scored according to the Chinese career success scale, Chinese version of the psychological resilience scale for nurses and Chinese version of the second victim experience and support tool. The t-test and one-way analysis of variance were used to compare the factors affecting career success. RESULTS: Career success scores differed among nurses of different ages having different employment forms, role and working years (p < .05). Mediating effect analysis revealed that psychological resilience played a full mediating role in the experience and support of second victims and their career success. CONCLUSION: Psychological resilience-based interventions should be developed to improve the psychological adjustment ability of psychiatric nurses and to strengthen their career success. IMPLICATIONS FOR NURSING MANAGEMENT: Nursing managers should create more opportunities and a harmonious working environment and enhance the management system for dealing with workplace violence.

Evaluation of the Load Reduction Performance Via a Suspended Backpack With Adjustable Stiffness.

Backpacks are essential for travel but carrying a load during a long journey can easily cause muscle fatigue and joint injuries. Previous studies have suggested that suspended backpacks can effectively reduce the energy cost while carrying loads. Researchers have found that adjusting the stiffness of a suspended backpack can optimize its performance. Therefore, this paper proposes a stiffness-adjustable suspended backpack; the system stiffness can be adjusted to suitable values at different speeds. The stiffness of the suspended backpack with a 5-kg load was designed to be 690 N/m for a speed of 4.5 km/h, and it was adjusted to 870 and 1050 N/m at speeds of 5.5 and 6.5 km/h, respectively. The goal of this study was to determine how carrying a stiffness-adjustable suspended backpack affected performance while carrying a load. Six healthy participants participated in experiments where they wore two backpacks under three conditions: the adjustable-stiffness suspended backpack condition (S_A), the unadjustable-stiffness suspended backpack condition (S_UA), and the ordinary backpack condition (ORB). Our results showed that the peak accelerations, muscle activities, and peak ground reaction forces in the S_A condition were reduced effectively by adjusting the stiffness to adapt to different walking speeds; this adjustment decreased the metabolic cost by 4.21 ± 1.21% and 2.68 ± 0.88% at 5.5 km/h and 4.27 ± 1.35% and 3.38 ± 1.31% at 6.5 km/h compared to the ORB and S_UA, respectively.

Individual-based morphological brain network organization and its association with autistic symptoms in young children with autism spectrum disorder.

Individual-based morphological brain networks built from T1-weighted magnetic resonance imaging (MRI) reflect synchronous maturation intensities between anatomical regions at the individual level. Autism spectrum disorder (ASD) is a socio-cognitive and neurodevelopmental disorder with high neuroanatomical heterogeneity, but the specific patterns of morphological networks in ASD remain largely unexplored at the individual level. In this study, individual-based morphological networks were constructed by using high-resolution structural MRI data from 40 young children with ASD (age range: 2-8 years) and 38 age-, gender-, and handedness-matched typically developing children (TDC). Measurements were recorded as threefold. Results showed that compared with TDC, young children with ASD exhibited lower values of small-worldness (i.e., σ) of individual-level morphological brain networks, increased morphological connectivity in cortico-striatum-thalamic-cortical (CSTC) circuitry, and decreased morphological connectivity in the cortico-cortical network. In addition, morphological connectivity abnormalities can predict the severity of social communication deficits in young children with ASD, thus confirming an associational impact at the behavioral level. These findings suggest that the morphological brain network in the autistic developmental brain is inefficient in segregating and distributing information. The results also highlight the crucial role of abnormal morphological connectivity patterns in the socio-cognitive deficits of ASD and support the possible use of the aberrant developmental patterns of morphological brain networks in revealing new clinically-relevant biomarkers for ASD.

Physiological and biomechanical effects on the human musculoskeletal system while carrying a suspended-load backpack.

Many people need to carry heavy loads in a backpack to perform occupational, military, or recreational tasks. Suspended-load backpacks have been shown to reduce dynamic peak forces acting on the body and lower an individual's metabolic cost during walking. However, little is known about the physiological and biomechanical effects of a suspended-load backpack on the human musculoskeletal system. The goal of this study was to determine the impact of different types of backpacks on metabolic cost, joint kinetics, gait kinematics, and muscle activity while individuals carried the same load of 15 kg at a walking speed of 5 km/h and running speed of 7 km/h on an instrumented treadmill. A group of six healthy participants participated in experiments in which two different backpacks were worn under three different conditions: suspended-load backpack working condition (SLB_ON), suspended-load backpack locking condition (SLB_OFF), and ordinary backpack condition (ORB). The results showed that carrying the backpack in the SLB_ON condition can reduce lower limb muscle activities and biological joint work while decreasing the metabolic cost by 15.25 ± 4.21% and 8.81 ± 2.46% during walking and 12.53 ± 2.39% and 6.99 ± 2.37% during running compared to carrying the backpack in the SLB_OFF and the ORB conditions, respectively. However, the SLB_ON condition may cause increased shoulder strain and dynamic stability and balance problems. These results suggest that the control of load movement in a suspended-load backpack should be considered when locomotion performance is optimized in future studies.

Etiology and clinical characteristics of membranous nephropathy in Chinese patients.

BACKGROUND: Membranous nephropathy (MN) is a common cause of proteinuria and can be subdivided into idiopathic and secondary classifications. Most patients with MN present with associated systemic diseases that need to be identified before appropriately diagnosing idiopathic MN. However, the cause and clinical characteristics of MN in Chinese patients have not been investigated. STUDY DESIGN: Case series. SETTING & PARTICIPANTS: Patients with biopsy-proven MN at the Research Institute of Nephrology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China. OUTCOME: The diagnosis of idiopathic and secondary MN was based on clinical, initial laboratory, and histological findings. RESULTS: 390 patients with MN were identified from 1985 to 2005. Of 390 patients with MN, 124 (31.8%) had idiopathic MN and 266 had secondary MN (68.2%). Of patients with idiopathic MN, 75 (60.5%) were men and 49 (39.5%) were women. Mean age was 43.9 +/- 13.2 years (range, 14 to 78 years). Common presentations of idiopathic MN were 60.5% with proteinuria (39.5% of whom presented with nephrotic syndrome), 29.8% with hypertension, 17.7% with hematuria, and 0.8% with decreased kidney function. In patients with secondary MN, causes were autoimmune diseases (73.3%), infections (17.7%), tumors (4.5%), and drugs or toxins (4.5%). Systemic lupus erythematosus was the most common autoimmune disease (predominately in younger women). Hepatitis B predominated in younger men. Greater levels of proteinuria were found in patients who presented with drugs or toxins compared with patients with other secondary MNs (P < 0.05). LIMITATIONS: Not all patients underwent all tests, particularly serum tumor markers, hepatitis C virus antibody, and hepatitis C virus RNA tests. CONCLUSION: Proteinuria was a common presentation in patients with idiopathic MN, which was predominately found in middle-aged to elderly men. Secondary MN was more common than idiopathic MN, and most secondary MN diagnoses were secondary to systemic lupus erythematosus and hepatitis B infection.