Influence of Growth Process on Suppression of Surface Morphological Defects in 4H-SiC Homoepitaxial Layers.

To address surface morphological defects that have a destructive effect on the epitaxial wafer from the aspect of 4H-SiC epitaxial growth, this study thoroughly examined many key factors that affect the density of defects in 4H-SiC epitaxial wafer, including the ratio of carbon to silicon, growth time, application of a buffer layer, hydrogen etching and other process parameters. Through systematic experimental verification and data analysis, it was verified that when the carbon-silicon ratio was accurately controlled at 0.72, the density of defects in the epitaxial wafer was the lowest, and its surface flatness showed the best state. In addition, it was found that the growth of the buffer layer under specific conditions could effectively reduce defects, especially surface morphology defects. This provides a new idea and method for improving the surface quality of epitaxial wafers. At the same time, we also studied the influence of hydrogen etching on the quality of epitaxial wafers. The experimental results show that proper hydrogen etching can optimize surface quality, but excessive etching may lead to the exposure of substrate defects. Therefore, it is necessary to carefully control the conditions of hydrogen etching in practical applications to avoid adverse effects. These findings have important guiding significance for optimizing the quality of epitaxial wafers.

Influence of Carbon Source on the Buffer Layer for 4H-SiC Homoepitaxial Growth.

In this study, we systematically explore the impact of C/Si ratio, pre-carbonization time, H2 etching time, and growth pressure on the buffer layer and subsequent epitaxial layer of 6-inch 4H-SiC wafers. Our findings indicate that the buffer layer's C/Si ratio and growth pressure significantly influence the overall quality of the epitaxial wafer. Specifically, an optimal C/Si ratio of 0.5 and a growth pressure of 70 Torr yield higher-quality epitaxial layers. Additionally, the pre-carbonization time and H2 etching time primarily affect the uniformity and surface quality of the epitaxial wafer, with a pre-carbonization time of 3 s and an H2 etching time of 3 min found to enhance the surface quality of the epitaxial layer.

Determining the Hot Workability and Microstructural Evolution of an Fe-Cr-Mo-Mn Steel Using 3D Processing Maps.

The Laasraoui segmented and Arrhenius flow stress model, dynamic recrystallization (DRX) model, grain size prediction model, and hot processing map (HPM) of Fe-Cr-Mo-Mn steels were established through isothermal compression tests. The models and HPM were proven by experiment to be highly accurate. As the deformation temperature decreased or the strain rate increased, the flow stress increased and the grain size of the Fe-Cr-Mo-Mn steel decreased, while the volume fraction of DRX (Xdrx) decreased. The optimal range of the hot processing was determined to be 1050-1200 °C/0.369-1 s-1. Zigzag-like grain boundaries (GBs) and intergranular cracks were found in the unstable region, in which the disordered martensitic structure was observed. The orderly packet martensite was formed in the general processing region, and the mixed structure with incomplete DRX grains was composed of coarse and fine grains. The microstructure in the optimum processing region was composed of DRX grains and the multistage martensite. The validity of the Laasraoui segmented flow stress model, DRX model, grain size prediction model, and HPM was verified by upsetting tests.

Defect compensation and intervalence charge transfer state-based Pr3+-doped niobate antithermal quenching phosphors.

Herein, a scheme of Sr2+/Ca2+ ion substitution was employed to simultaneously regulate the defect and intervalence charge transfer (IVCT) state of Sr2-xCaxNb2O7:Pr3+ phosphors, resulting in a dual-modulation strategy for enhancing phosphor thermal stability.

Complexin-1 enhances ultrasound neurotransmission in the mammalian auditory pathway.

Unlike megabats, which rely on well-developed vision, microbats use ultrasonic echolocation to navigate and locate prey. To study ultrasound perception, here we compared the auditory cortices of microbats and megabats by constructing reference genomes and single-nucleus atlases for four species. We found that parvalbumin (PV)+ neurons exhibited evident cross-species differences and could respond to ultrasound signals, whereas their silencing severely affected ultrasound perception in the mouse auditory cortex. Moreover, megabat PV+ neurons expressed low levels of complexins (CPLX1-CPLX4), which can facilitate neurotransmitter release, while microbat PV+ neurons highly expressed CPLX1, which improves neurotransmission efficiency. Further perturbation of Cplx1 in PV+ neurons impaired ultrasound perception in the mouse auditory cortex. In addition, CPLX1 functioned in other parts of the auditory pathway in microbats but not megabats and exhibited convergent evolution between echolocating microbats and whales. Altogether, we conclude that CPLX1 expression throughout the entire auditory pathway can enhance mammalian ultrasound neurotransmission.

Field survey data for conservation: Evaluating suitable habitat of Chinese pangolin at the county-level in eastern China (2000-2040).

The scarcity of up-to-date data on the distribution and dynamics of the Chinese pangolin (Manis pentadactyla) presented a significant challenge in developing effective conservation strategies and implementing protective measures within China. Currently, most of China's national-level nature reserves and administrative departments operate at the county level, thereby limiting the applicability of larger-scale analyses and studies for these administrative entities. This study employed 11 widely used modeling techniques created within the Biomod2 framework to predict suitable habitats for the pangolin at the county scale, while examining the correlation between environmental variables and pangolin distribution. The results revealed that highly suitable habitats in Mingxi County of China encompassed only 49 km2. Within the county-managed nature reserve, the proportion of highly suitable habitats reached as high as 52%. However, nearly half of these areas, both moderately and highly suitable habitats, remained inadequately addressed and conserved. We found nine administrative villages that necessitated prioritized conservation efforts. The study anticipated an overall expansion in suitable habitats over the ensuing two decades, with significant growth projected in the eastern regions of Xiayang and Hufang Town. This research offered a clear and applicable research paradigm for the specific administrative level at which China operates, particularly pertinent to county-level jurisdictions with established nature reserves.

Nonlinear Conductivity and Thermal Stability of Anti-Corona Epoxy Resin Nanocomposites.

The long-term operation of motors induces substantial alterations in the surface conductivity and nonlinear coefficient of anti-corona paint, diminishing its efficacy and jeopardizing the longevity of large motors. Hence, the development of high-performance anti-corona paint holds paramount importance in ensuring motor safety. In this study, we integrate two nano-fillers, namely silicon carbide (SiC) and organic montmorillonite (O-MMT), into a composite matrix comprising micron silicon carbide and epoxy resin (SiC/EP). Subsequently, three distinct types of anti-corona paint are formulated: SiC/EP, Nano-SiC/EP, and O-MMT/SiC/EP. Remarkably, O-MMT/SiC/EP exhibits a glass transition temperature about 25 °C higher than that of SiC/EP, underscoring its superior thermal properties. Moreover, the introduction of nano-fillers markedly augments the surface conductivity of the anti-corona paint. Aging tests, conducted across varying temperatures, unveil a notable reduction in the fluctuation range of surface conductivity post-aging. Initially, the nonlinear coefficients exhibit a declining trend, succeeded by an ascending trajectory. The O-MMT/SiC/EP composite displays a maximum nonlinearity coefficient of 1.465 and a minimum of 1.382. Furthermore, the incorporation of nanofillers amplifies the dielectric thermal stability of epoxy resin composites, with O-MMT/SiC/EP showcasing the pinnacle of thermal endurance. Overall, our findings elucidate the efficacy of nano-fillers in enhancing the performance and longevity of anti-corona paint, particularly highlighting the exceptional attributes of the O-MMT/SiC/EP composite in bolstering motor safety through improved thermal stability and electrical properties.

Correction to "Diterpenoid Tanshinones Can Inhibit Lung Cancer Progression by Improving the Tumor Microenvironment and Downregulation of NF-κB Expression".

[This corrects the article DOI: 10.1021/acsomega.3c09667.].

Effect of TCS gas flow and pre-etching on homopitaxial growth of 4H-SiC.

In this study, the epitaxial growth of 6-inch n-type 4° off-axis Si-face substrates using a horizontal hot-wall LPCVD system was investigated. The study explored the epitaxial growth under different source gas flow rates, growth pressures, and pre-etching times, with particular emphasis on their effects on epitaxial growth rate, epitaxial layer thickness uniformity, doping concentration and uniformity, and epitaxial layer surface roughness. The observation was made that the increase in source gas flow rate led to variations in dopant concentration due to different transport models between nitrogen gas and source gas. Additionally, with the increase in etching time, overetching phenomena occurred, resulting in changes in both dopant concentration and uniformity. Furthermore, the relationships between these three factors and their corresponding indicators were explained by combining the CVD growth process with the laminar flow model. These observed patterns are beneficial for further optimizing growth conditions in industrial settings, ultimately enhancing the quality of the growth process.

In-Plane Combination of Micropillars with Distinct Aspect Ratios to Resist Overload-Induced Adhesion Failure.

Bioinspired micropillar adhesives have shown broad application prospects in space capture and docking, due to their strong adhesion, good environmental adaptability, and reusability. However, when performing space missions, unavoidable contact collision with target objects may cause large deformation of the micropillars, resulting in the loss of adhesion ability. This study reports a novel micropillar adhesive through the in-plane combination of micropillars (IPCM) with different aspect ratios, consisting of small pillars for retaining strong adhesion and large ones for resisting overload-induced adhesion failure. It is demonstrated that the IPCM array can still maintain 85% of the adhesion peak after static large deformation compared to a general micropillar array composed of the same pillars. The impact of element size and layout of the IPCM, as well as detachment velocity on adhesion performance under high preload is discussed. Furthermore, finite element contact analysis qualitatively reproduces the experimentally observed micropillar deformations and attributes the overload-induced adhesion failure to the redistribution of surface normal stress. Finally, the potential application of the IPCM in dynamic capture is demonstrated on different objects. The proposed IPCM opens up new design concepts for practical applications of bioinspired adhesives in space capture and docking.

Research on the Influence of Carbon Sources and Buffer Layers on the Homogeneous Epitaxial Growth of 4H-SiC.

In this study, a 4H-SiC homoepitaxial layer was grown on a 150 mm 4° off-axis substrate using a horizontal hot wall chemical vapor deposition reactor. Comparing C3H8 and C2H4 as C sources, the sample grown with C2H4 exhibited a slower growth rate and lower doping concentration, but superior uniformity and surface roughness compared to the C3H8-grown sample. Hence, C2H4 is deemed more suitable for commercial epitaxial wafer growth. Increasing growth pressure led to decreased growth rate, worsened thickness uniformity, reduced doping concentration, deteriorated uniformity, and initially improved and then worsened surface roughness. Optimal growth quality was observed at a lower growth pressure of 40 Torr. Furthermore, the impact of buffer layer growth on epitaxial quality varied significantly based on different C/Si ratios, emphasizing the importance of selecting the appropriate conditions for subsequent device manufacturing.

Corneal subbasal nerve plexus reinnervation and stromal cell morphology with different cap thicknesses in small incision lenticule extraction.

PURPOSE: The corneal cap thickness is a vital parameter designed in small incision lenticule extraction (SMILE). The purpose was to investigate the changes in corneal subbasal nerve plexus (SNP) and stromal cells with different cap thicknesses and evaluate the optimized design for the surgery. METHODS: In this prospective, comparative, non-randomized study, a total of 108 eyes of 54 patients who underwent SMILE were allocated into three groups with different corneal cap thicknesses (110 µm, 120 µm or 130 µm group). The SNP and stromal cell morphological changes obtained from in vivo corneal confocal microscopy (IVCCM) along with their refractive outcomes were collected at 1 week, 1 month, 3 months and 6 months postoperatively. One-way analysis of variance (ANOVA) was used to compare the parameters among the three groups. RESULTS: The SNPs in the three groups all decreased after surgery and revealed a gradual increasing trend during the 6-month follow-up. The values of the quantitative nerve metrics were significantly lower in the 110 µm group than in the 120 µm and 130 µm groups, especially at 1 week postoperatively. No difference was detected between the 120 µm and 130 µm groups at any time point. Both Langerhans cells and keratocytes were activated after surgery, and the activation was alleviated during the follow-up. CONCLUSIONS: The SMILE surgeries with 110 µm, 120 µm or 130 µm cap thickness design achieved good efficacy, safety, accuracy and stability for moderate to high myopic correction while the thicker corneal cap was more beneficial for corneal nerve regeneration.

Exploring the efficacy of photodynamic antimicrobial chemotherapy on diabetic foot ulcers in rats.

We investigate the efficacy of photodynamic antimicrobial chemotherapy (PACT) and its combination with an antibiotic in the treatment of diabetic foot ulcers (DFUs) in rats using a novel cationic amino acid porphyrin-based photosensitizer. The research findings demonstrate that the combination of novel cationic photosensitizer-mediated PACT and an antibiotic exhibits significant therapeutic efficacy in treating deep ulcers in a rat model of DFUs. Moreover, the PACT + Antibiotic group displays enhanced angiogenesis, improved tissue maturation, and superior wound healing effect. Micro-computed tomography examination showed that the periosteal reaction was most obvious in the PACT + Antibiotic group. The cortical bone volume ratio (BV/TV), the bone mineral density, and trabecular thickness were significantly higher in the PACT + Antibiotic group than in the model group (p < 0.05). The combination of PACT and antibiotic plays a sensitizing therapeutic role, which provides a new idea for the clinical treatment of DFUs.

Posterior tibial slope influences joint mechanics and soft tissue loading after total knee arthroplasty.

As a solution to restore knee function and reduce pain, the demand for Total Knee Arthroplasty (TKA) has dramatically increased in recent decades. The high rates of dissatisfaction and revision makes it crucially important to understand the relationships between surgical factors and post-surgery knee performance. Tibial implant alignment in the sagittal plane (i.e., posterior tibia slope, PTS) is thought to play a key role in quadriceps muscle forces and contact conditions of the joint, but the underlying mechanisms and potential consequences are poorly understood. To address this biomechanical challenge, we developed a subject-specific musculoskeletal model based on the bone anatomy and precise implantation data provided within the CAMS-Knee datasets. Using the novel COMAK algorithm that concurrently optimizes joint kinematics, together with contact mechanics, and muscle and ligament forces, enabled highly accurate estimations of the knee joint biomechanics (RMSE <0.16 BW of joint contact force) throughout level walking and squatting. Once confirmed for accuracy, this baseline modelling framework was then used to systematically explore the influence of PTS on knee joint biomechanics. Our results indicate that PTS can greatly influence tibio-femoral translations (mainly in the anterior-posterior direction), while also suggesting an elevated risk of patellar mal-tracking and instability. Importantly, however, an increased PTS was found to reduce the maximum tibio-femoral contact force and improve efficiency of the quadriceps muscles, while also reducing the patellofemoral contact force (by approximately 1.5% for each additional degree of PTS during walking). This study presents valuable findings regarding the impact of PTS variations on the biomechanics of the TKA joint and thereby provides potential guidance for surgically optimizing implant alignment in the sagittal plane, tailored to the implant design and the individual deficits of each patient.

Study of the Extremely Low-Frequency Noise Characteristics of a Micro-Thrust Measurement Platform.

The critical structural parameters are optimized and studied using the numerical simulation method to improve the resolution and stability of the Micro-Thrust Measurement Platform (MTMP). Under two different ground random vibration environments, the parameters, such as pivot thickness, pendulum rod length, and pivot structure, are focused on analyzing the influence of the system's resolution and stability. The results show that when the thickness of the pivot is 0.04 mm or 0.2 mm, and the pendulum rod length is 2 m, the effect of ground random vibration on the MTMP is minimized. At 0.1 mHz, it can reach 0.0057 µN/Hz. In the series double-pivot structure, an appropriate increase in the distance between the sheets can further optimize the above conclusions. The results and analysis within this study can provide support for the engineering design of the MTMP.

Hygroscopic cooling (h-cool) fabric with highly efficient sweat evaporation and heat dissipation for personal thermo-moisture management.

Moisture evaporation plays a crucial role in thermal management of human body, particularly in perspiration process. However, current fabrics aim for sweat removal and takes little account of basic thermo-regulation of sweat, resulted in their limited evaporation capacity and heat dissipation at moderate/intense scenarios. In this study, a hygroscopic cooling (h-cool) fabric based on multi-functional design, for personal perspiration management, was described. By using economic and effective weaving technology, directional moisture transport routes and heat conductive pathways were incorporated in the construct. The resultant fabric showed 10 times greater one-way transport index higher than cotton, Dri-FIT and Coolswitch fabrics, which contributed to highly enhanced evaporation ability (∼4.5 times than cotton), not merely liquid diffusion. As a result, h-cool fabric performed 2.1-4.2 °C cooling efficacy with significantly reduced sweat consuming than cotton, Dri-FIT and Coolswitch fabrics in the artificial sweating skin. Finally, the practical applications by actually wearing h-cool fabric showed great evaporative-cooling efficacy during different physical activities. Owing to the excellent thermo-moisture management ability, we expect the novel concept and construct of h-cool fabric can provide promising strategy for developing functional textiles with great "cool" and comfortable "dry" tactile sensation at various daily scenarios.

Efficacy of Wearable low-intensity pulsed Ultrasound treatment in the Movement disorder in Parkinson's disease (the SWUMP trial): protocol for a single-site, double-blind, randomized controlled trial.

BACKGROUND: Parkinson's disease (PD) is a progressive, neurodegenerative illness marked by the loss of dopaminergic neurons, causing motor symptoms. Oral levodopa replacement therapy remains the gold standard in the treatment of PD. It is, nevertheless, a symptomatic treatment. There is currently no effective treatment for PD. Therefore, new therapies for PD are highly desirable. Low-intensity pulsed ultrasound (LIPUS) has been shown to improve behavioral functions in PD animal models. It is a new type of neuromodulation approach that combines noninvasiveness with high spatial precision. The purpose of this study is to establish a new clinical protocol for LIPUS in the treatment of movement disorders in patients with PD. METHODS: This protocol is a single-site, prospective, double-blind, randomized controlled trial (RCT). Forty-eight participants with clinically confirmed PD will be randomly allocated to one of two groups: LIPUS group or sham group. All of the participants continue to use pharmacological therapy as a fundamental treatment. The primary outcome is the difference between groups from baseline to 4 months in the change in the Unified Parkinson's Disease Rating Scale (UPDRS) motor score (part III). The secondary outcomes include the rating scales such as the Mini-Mental State Examination (MMSE), and other three rating scales, and medical examinations including high-density electroencephalography (hdEEG) and functional magnetic resonance imaging (fMRI). The primary safety outcome will be assessed at 4 months, and adverse events will be recorded. DISCUSSION: This study represents the clinical investigation into the efficacy of therapeutic LIPUS in the treatment of PD for the first time. If LIPUS is determined to be effective, it could offer a practical and innovative means of expanding the accessibility of ultrasound therapy by using a wearable LIPUS device within a home setting. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2100052093. Registered on 17 October 2021.

Intravascular ultrasound-guided versus angiography-guided percutaneous coronary intervention in acute coronary syndromes (IVUS-ACS): a two-stage, multicentre, randomised trial.

BACKGROUND: Intravascular ultrasound-guided percutaneous coronary intervention has been shown to result in superior clinical outcomes compared with angiography-guided percutaneous coronary intervention. However, insufficient data are available concerning the advantages of intravascular ultrasound guidance for patients with an acute coronary syndrome. This trial aimed to investigate whether the use of intravascular ultrasound guidance, as compared with angiography guidance, improves the outcomes of percutaneous coronary intervention with contemporary drug-eluting stents in patients presenting with an acute coronary syndrome. METHODS: In this two-stage, multicentre, randomised trial, patients aged 18 years or older and presenting with an acute coronary syndrome at 58 centres in China, Italy, Pakistan, and the UK were randomly assigned to intravascular ultrasound-guided percutaneous coronary intervention or angiography-guided percutaneous coronary intervention. Patients, follow-up health-care providers, and assessors were masked to random assignment; however, staff in the catheterisation laboratory were not. The primary endpoint was target vessel failure, a composite of cardiac death, target vessel myocardial infarction, or clinically driven target vessel revascularisation at 1 year after randomisation. This trial is registered at ClinicalTrials.gov, NCT03971500, and is completed. FINDINGS: Between Aug 20, 2019 and Oct 27, 2022, 3505 patients with an acute coronary syndrome were randomly assigned to intravascular ultrasound-guided percutaneous coronary intervention (n=1753) or angiography-guided percutaneous coronary intervention (n=1752). 1-year follow-up was completed in 3504 (>99·9%) patients. The primary endpoint occurred in 70 patients in the intravascular ultrasound group and 128 patients in the angiography group (Kaplan-Meier rate 4·0% vs 7·3%; hazard ratio 0·55 [95% CI 0·41-0·74]; p=0·0001), driven by reductions in target vessel myocardial infarction or target vessel revascularisation. There were no significant differences in all-cause death or stent thrombosis between groups. Safety endpoints were also similar in the two groups. INTERPRETATION: In patients with an acute coronary syndrome, intravascular ultrasound-guided implantation of contemporary drug-eluting stents resulted in a lower 1-year rate of the composite outcome of cardiac death, target vessel myocardial infarction, or clinically driven revascularisation compared with angiography guidance alone. FUNDING: The Chinese Society of Cardiology, the National Natural Scientific Foundation of China, and Jiangsu Provincial & Nanjing Municipal Clinical Trial Project. TRANSLATION: For the Mandarin translation of the abstract see Supplementary Materials section.

Associations between Present-on-Admission Do-Not-Resuscitate Orders and Short-Term Outcomes in Patients with Pneumonia.

OBJECTIVES: Do-not-resuscitate (DNR) orders are used to express patient preferences for cardiopulmonary resuscitation. This study examined whether early DNR orders are associated with differences in treatments and outcomes among patients hospitalized with pneumonia. METHODS: This is a retrospective cohort study of 768,015 adult patients hospitalized with pneumonia from 2010 to 2015 in 646 US hospitals. The exposure was DNR orders present on admission. Secondary analyses stratified patients by predicted in-hospital mortality. Main outcomes included in-hospital mortality, length of stay, cost, intensive care admission, invasive mechanical ventilation, noninvasive ventilation, vasopressors, and dialysis initiation. RESULTS: Of 768,015 patients, 94,155 (12.3%) had an early DNR order. Compared with those without, patients with DNR orders were older (mean age 80.1 ± 10.6 years vs 67.8 ± 16.4 years), with higher comorbidity burden, intensive care use (31.6% vs 30.6%), and in-hospital mortality (28.2% vs 8.5%). After adjustment via propensity score weighting, these patients had higher mortality (odds ratio [OR] 2.39, 95% confidence interval [CI] 2.33-2.45) and lower use of intensive therapies such as vasopressors (OR 0.83, 95% CI 0.81-0.85) and invasive mechanical ventilation (OR 0.68, 95% CI 0.66-0.70). Although there was little relationship between predicted mortality and DNR orders, among those with highest predicted mortality, DNR orders were associated with lower intensive care use compared with those without (66.7% vs 80.8%). CONCLUSIONS: Patients with early DNR orders have higher in-hospital mortality rates than those without, but often receive intensive care. These orders have the most impact on the care of patients with the highest mortality risk.

Novel PLCZ1 mutation caused polyspermy during in vitro fertilization.

Failure of oocyte activation, including polyspermy and defects in pronuclear (PN) formation, triggers early embryonic developmental arrest. Many studies have shown that phospholipase C zeta 1 ( PLCZ1 ) mutations cause failure of PN formation following intracytoplasmic sperm injection (ICSI); however, whether PLCZ1 mutation is associated with polyspermy during in vitro fertilization (IVF) remains unknown. Whole-exome sequencing (WES) was performed to identify candidate mutations in couples with primary infertility. Sanger sequencing was used to validate the mutations. Multiple PLCZ1 -mutated sperm were injected into human and mouse oocytes to explore whether PN formation was induced. Assisted oocyte activation (AOA) after ICSI was performed to overcome the failure of oocyte activation. We identified three PLCZ1 mutations in three patients who experienced polyspermy during IVF cycles, including a novel missense mutation c.1154C>T, p.R385Q. PN formation failure was observed during the ICSI cycle. However, injection of multiple PLCZ1- mutated sperm induced PN formation, suggesting that the Ca 2+ oscillations induced by the sperm exceeded the necessary threshold for PN formation. AOA after ICSI enabled normal fertilization, and all patients achieved successful pregnancies. These findings expand the mutational spectrum of PLCZ1 and suggest an important role for PLCZ1 in terms of blocking polyspermy. Furthermore, this study may benefit genetic diagnoses in cases of abnormal fertilization and provide potential appropriate therapeutic measures for these patients with sperm-derived polyspermy.