Abstract ：

We examine the relation between the scale and scope of an individual auditor’s client portfolio and audit quality. Using a sample of auditor-years for the period of 2001–2016 from China, where the personal identities of signing auditors are publicly disclosed, we find that auditors with large client portfolio scale (measured by an auditor’s total audit fees from clients) provide higher quality audits (measured by discretionary accruals and the likelihood of issuing modified audit opinions). However, auditors with large client portfolio scope (measured by the number of industries where clients are located) provide lower quality audits. Further analyses indicate that auditors of higher ability and reputation tend to have larger client scales and wider client scopes. Overall, our results suggest that, at the individual auditor level, the scale of the client portfolio conveys the auditor’s ability, and given the scale, the industry and geographic scope of clients reflects the auditor’s workload. © 2023 Informa UK Limited, trading as Taylor & Francis Group.

Keyword ：

audit fees; audit quality; client portfolio; individual auditor; scale; scope

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Abstract ：

The field of small molecule electro-activated conversion is becoming a new star in modern catalytic research toward the carbon-neutral future. The advent of single-atom catalysts (SACs) is expected to greatly accelerate the kinetics of electrocatalytic reactions such as the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), hydrogen oxidation reaction (HOR), etc., owing to their maximum atomic efficiency, unique quantized energy level structure and strong interaction between well-defined active sites and supports. In this feature article, our group's proposed synthesis methodology applied in electrocatalysis is mainly summarized. Furthermore, we elaborate on how to achieve the stabilization of single metal atoms against migration and agglomeration during the preparation of SACs. Moreover, the electrochemical applications of SACs with a focus on the above heterogeneous reactions are presented. Finally, the prospects for the development and deficiencies of these SACs for electrocatalytic reactions are discussed. © 2023 The Royal Society of Chemistry.

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Thermal barrier coatings (TBCs) are subjected to high temperature and complex stress fields during service in gas turbines. In this process, densification and hardening take place as the result of sintering, which is sensitive to boundary condition/external load. The stress-dependent sintering behaviors of porous TBCs were investigated in this work using a customized four-point bending method. Furthermore, stress-dependent sintering model was developed and implemented in finite element analysis to elucidate sintering mechanisms. It was found that stress gradient induced nonlinear differential sintering behavior, due to the accelerating and retarding effects of compressive and tensile stresses, respectively. In addition, microstructure-mechanical property relation was determined following the exponential law and high-throughput method was proposed for the characterization of stress dependence. The in-depth understanding of stress-dependent sintering behavior could provide guidance to the design and failure analysis of TBCs applied on complex shaped components in the hot section of gas turbines. © 2023 Elsevier Ltd

Keyword ：

Finite element analysis; Four-point bending; Sintering; Stress dependence; Thermal barrier coatings

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A major sign of aging is wrinkles (dynamic lines and static lines) on the surface of the skin. In spite of Botulinum toxin's favorable therapeutic effect today, there have been several reports of its toxicity and side effects. Therefore, the development of an effective and safe wrinkle-fighting compound is imperative. An antioxidant-wrinkle effect was demonstrated by the peptide that we developed and synthesized, termed Skin Peptide. Aiming at the intrinsic defects of the peptide such as hydrolysis and poor membrane penetration, we developed a general approach to transform the Skin Peptide targeting intracellular protein-protein interaction into a bioavailable peptide-gold spherical nano-hybrid, Skin Pcluster. As expected, the results revealed that Skin Pcluster reduced the content of acetylcholine released by neurons in vitro, and then inhibit neuromuscular signal transmission. Additionally, human experiments demonstrated a significant de-wrinkle effect. Moreover, Skin Pcluster is characterized by a reliable safety profile. Consequently, anti-wrinkle peptides and Skin Pcluster nanohybrids demonstrated innovative anti-wrinkle treatments and have significant potential applications.

Keyword ：

anti-aging anti-wrinkle biomaterial nanohybrid peptide

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Aiming at the performance degradation and failure of compressors caused by particle fouling and erosion damage, the research progress of domestic and foreign research institutions in the influence of particle fouling and erosion damage on the performance of axial compressors in recent years was systematically summarized. Numerical simulation methods, experimental research methods and typical research conclusions about the compressor performance degradation mechanism and characteristics caused by fouling and erosion damage were emphatically introduced. Based on the current research hotspots and development tendency, further studies focus on the impact of particle fouling and erosion damage on the characteristic of axial compressors performance degradation were proposed. The interaction mechanism between the details of the unsteady flow field in the axial flow compressor cascades and the motion behavior of fine particles should be explored through refined numerical simulation and visualization experiment technology. Thus, the mechanism of compressor performance degradation caused by particle deposition and erosion damage could be revealed, and finally, quantitative relationship between particle deposition, erosion damage and compressor performance degradation should be established. © 2022 Shanghai Power Equipment Research Institute. All rights reserved.

Keyword ：

axial compressor; erosion damage; particle fouling; performance degradation; surface roughness

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Objective. Histotripsy is a non-invasive focused ultrasound ablation method that can mechanically disintegrate tissues. This study aims to verify that ultrasound-guided histotripsy using millisecond-length two-stage ultrasound pulses combined with fundamental and second harmonic superposition can enhance treatment in rabbit kidneys in vivo. Approach. Rabbit kidneys (n = 10) were treated using a custom-designed 1.1/2.2 MHz two-element confocal-annular array, with lateral and axial full width at half-maximum pressure dimensions of approximately 1.0 and 6.0 mm. Two-stage ultrasound pulses were applied: stage 1 used 60-80 pulses with a pulse duration of 6 ms and a pulse repetition frequency of 10 Hz. Meanwhile, stage 2 consists of 2-4 periods, each period consists of a concentrated pulse train of localized high DC of 6% and an off-time of 3-5 s, with an average DC of 1%-1.5%. B-mode ultrasound imaging was used to guide and monitor the boiling and cavitation bubbles. Main results. Ultrasound-guided treatment was successful in all rabbits, and the ablation rate is about seven times that of single-frequency combined two-stage pulses, achieving enhanced histotripsy. The regular elliptical lesions with dimensions of 10.6 ± 0.8 mm × 3.9 ± 0.6 mm (axial × lateral) were generated, and a large-volume lesion was generated by multi-point treatment. The size of most lysates was about 2.5 μm. Histologically, lesions were completely homogenized and well demarcated between treated-untreated areas. There was no apparent damage to critical structures surrounding lesions. Nonlinear simulations revealed that it may be the interaction between shock front and the cavitation and boiling bubbles generated by the dual-frequency effect enhanced the treatment efficiency. Significance. The novel histotripsy could improve treatment efficiency and generate regular elliptical lesions with controllable shape and axial dimensions, which may be a useful tool in treating renal cell carcinoma. © 2022 Institute of Physics and Engineering in Medicine.

Keyword ：

boiling; fundamental and second harmonic superposition; millisecond-length two-stage ultrasound pulses; ultrasound-guided and monitored histotripsy

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Introduction To improve compliance with voiding diaries in children with primary monosymptomatic nocturnal enuresis (PMNE), a new modified 3-day weekend frequency-volume chart (FVC) was designed, and the compliance and validity of this modified FVC was evaluated by comparing with the International Children's Continence Society (ICCS) recommended voiding diary. Methods A total of 1200 patients with PMNE were enrolled in the study from 13 centers in China and were randomly assigned to record this modified FVC or the ICCS-recommended voiding diary. The primary outcome measure was the compliance, assessed by comparing the completing index and the quality score of diaries between two groups. The secondary outcome measure was the validity, evaluated by comparing the constituent of subtypes, micturition parameters and response rate to desmopressin. Results Among the 1200 participants enrolled in the study, 447 patients completed the ICCS-recommended voiding diary and 469 completed the modified diary. The diurnal completing index and the quality score of the modified FVC group were better than those of the ICCS group. In addition, there was no significant difference between these two groups in the subtype classification, or in the response rate to desmopressin. Conclusions The modified FVC could be applied to obtain the voiding characteristics of children with PMNE as the ICCS-recommended voiding diary does and offers a reasonable and better choice for children with PMNE from the unselected population in the future.

Keyword ：

Children Compliance Nocturnal enuresis Voiding diary

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To investigate the current situation of neonatal care resources (NCR), newborn mortality rates (NMR), regional differences and existing challenges in China.By using a self-designed questionnaire form and the cross-sectional method, we conducted a survey of all hospitals equipped with neonatal facilities in China from March 2019 to March 2020 with respect to the level and nature of these hospitals, the number of newborn beds and NICU beds, the number of neonatal pediatricians, and the development of therapeutic techniques. The data about the newborn births and deaths were retrieved from the annual statistics of the health commissions of the related provinces, autonomous regions and municipalities.Included in this nationwide survey were 3,020 hospitals from all 22 provinces, 5 autonomous regions and 4 municipalities directly under the Central Government of Mainland China, with a 100% response rate. They included 1,183 (39.2%) level-3 (L3) hospitals, 1629 (53.9%) L-2 hospitals and 208 (6.9%) L-1 hospitals. Geographically, 848 (31.4%) hospitals were distributed in Central China, 983 (32.5%) hospitals in East China, and 1,089 (36.1%) in West China. The 3,020 included hospitals were altogether equipped with 75,679 newborn beds, with a median of 20 (2-350) beds, of which 2,286 hospitals (75.7%) were equipped with neonatal intensive care units (NICU), totaling 28,076 NICU beds with a median of 5 (1-160) beds. There were altogether 27,698 neonatal pediatricians in these hospitals, with an overall doctor-bed ratio of 0.366. There were 48.18 newborn beds and 17.87 NICU beds per 10,000 new births in China. In East, Central and West China, the number of neonatal beds, NICU beds, neonatal pediatricians, and attending pediatricians or pediatricians with higher professional titles per 10,000 newborns was 42.57, 48.64 and 55.67; 17.07, 18.66 and 18.17; 16.26, 16.51 and 20.81; and 10.69, 10.81 and 11.29, respectively. However, when the population and area are taken into consideration and according to the health resources density index (HRDI), the number of newborn beds, NICU beds and neonatal pediatricians in West China was significantly lower than that in Central and East China. In addition, only 10.64% of the neonatal pediatricians in West China possessed the Master or higher degrees, vs. 31.7% in East China and 20.14% in Central China. On the contrary, the number of neonatal pediatricians with a lower than Bachelor degree in West China was significantly higher than that in Central and East China (13.28% vs. 7.36% and 4.28%). Technically, the application rate of continuous positive airway pressure (CPAP) and conventional mechanical ventilation (CMV) in L-1 hospitals of West China was lower than that in Central and East China. According to the statistics in 2018, the newborn mortality rate (NMR) in West China was significantly higher than that in Central and East China.China has already possessed relatively good resources for neonatal care and treatment, which is the primary reason for the rapid decrease in the NMR in China. However, there are still substantial regional differences. The density of health resources, the level of technical development and educational background of neonatal pediatricians in West China still lag behind those in other regions of China and need to be further improved and upgraded.This research work was funded by National Natural Science Foundation of China (81671504) and United Nations International Children's Emergency Fund (CHINA-UNICEF501MCH).

Keyword ：

neonatal care resources neonatal intensive care unit newborn mortality rate survey

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Furnishing boundary slip at one of the liquid/solid interfaces in a bearing contact has been proven able to reduce bearing friction in a few recent studies conducted under mild running conditions where thermal effect is insignificant. However, if the concept is applied to practical conditions, how the slip affects temperature rise and its coupling effect with heat are still unknown. Thus, this study aims to investigate the boundary slip effect under adverse operating conditions. A thermal point contact elastohydrodynamic lubricated analysis which takes into consideration of boundary slip on one of the bearing surfaces is conducted. A generalized Reynolds equation is derived. The coupled effects of boundary slip and heat on EHL contacts under large slide-roll ratio conditions are investigated.

Keyword ：

Boundary slip EHL Large slide-roll ratio Thermal effect

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Through real-Time acquisition of visual characteristics of wear debris in lube oil, OLVF achieves on-line monitoring of equipment wear in practice. However, since a large number of bubbles exist in lube oil, which appear as a dynamically changing interference shadow in OLVF ferrograms, the traditional algorithms may easily misidentify the interference shadow as wear debris, resulting in a large error in the extracted wear debris characteristic. Based on this, an UDCT-based method for binarization of wear debris images was proposed. Through multi-scale analysis of OLVF ferrogram using UDCT and non-linear transformation of UDCT coefficients, low-frequency suppression and high-frequency denoising of wear debris images were conducted. Then, Otsu algorithm was used to realize binarization of wear debris images under strong interferences. © 2018 IEEE.

Keyword ：

Binarization; Ferrography; UDCT

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