BIOMECHANICAL ANALYSIS ON TAKE-OFF TECHNIQUE OF CHINESE AND WORLD-CLASS TRIPLE-JUMPERS

The triple jump is a demanding field event in which a jumper must tolerate extremely high impact forces while maintaining high horizontal speed. The present study was designed to explore the take-off technique how to maintain high horizontal speed and achieve optimize effect in the hop, step and jump phases. The best performance of 8 China triplejumpers (mean performance was 16.01 m) were videotaped and analyzed. This paper compared the parameter with the technique of 18.29 m jump of Edwards in the 1995 WAC. The results showed that bigger push-off angle at toe off resulted in a high angled trajectory in the hop phase and increasing amortization difficulty of the step phase; earlier knee-bend made for less braking angle and loss of horizontal velocity; in the step and jump phase. Chinese jumpers bend the landing knee actively to lessen the forces from landing but delayed the drive into the push-off phase

Burden of kidney cancer and attributed risk factors in China from 1990 to 2019

BackgroundThe changing trends and risk-attributed burdens of kidney cancer in China are unknown. Therefore, this study aimed to describe the latest status and trends of kidney cancer burden in China and its associated risk factors.MethodsThe absolute numbers and rates of the incidence, deaths, and disability-adjusted life-years (DALYs) of kidney cancer in China were extracted from the Global Burden of Disease 2019 platform. Overall burden and burden attributed to smoking and high body mass index (BMI) were described. Average annual percent change (AAPC) was calculated to describe trend analyses from 1990 to 2019 using the Joinpoint regression program.ResultsIn 2019, 59,827 new cases, 23,954 deaths, and 642,799 DALYs of kidney cancer occurred in China, of which men accounted for 71.1, 70.5, and 72.0%, and the population aged ≥55 years accounted for 58.9, 77.9, and 60.1%, of new cases, deaths, and DALYs, respectively. From 1990 to 2019, the age-standardized incidence rate (per 100,000 person-years) increased from 1.16 in 1990 to 3.21 in 2019, with an AAPC of 3.4% (95% confidence interval [CI]: 3.1–3.8%, p < 0.05); the mortality rate increased from 0.70 to 1.27, with an AAPC of 2.1% (1.5–2.3%, p < 0.05); and the DALY rate increased from 0.70 to 1.27, with an AAPC of 2.1% (1.5–2.3%, p < 0.05). In 2019, the proportions of DALYs attributed to smoking and high BMI were 18.0% and 11.1%, respectively, and the DALY rates attributed to both smoking and high BMI increased from 1990 to 2019, with AAPC of 2.9% (2.6–3.3%, p < 0.05) and 4.8% (4.2–5.4%, p < 0.05), respectively.ConclusionThe kidney cancer burden in China has continued to grow over the recent three decades, with a severe burden among older adults and men. Therefore, timely preventive interventions for modifiable risk factors are required

Recent Progress in Metal-Organic Frameworks for Applications in Electrocatalytic and Photocatalytic Water Splitting

The development of clean and renewable energy materials as alternatives to fossil fuels is foreseen as a potential solution to the crucial problems of environmental pollution and energy shortages. Hydrogen is an ideal energy material for the future, and water splitting using solar/electrical energy is one way to generate hydrogen. Metal-organic frameworks (MOFs) are a class of porous materials with unique properties that have received rapidly growing attention in recent years for applications in water splitting due to their remarkable design flexibility, ultra-large surface-to-volume ratios and tunable pore channels. This review focuses on recent progress in the application of MOFs in electrocatalytic and photocatalytic water splitting for hydrogen generation, including both oxygen and hydrogen evolution. It starts with the fundamentals of electrocatalytic and photocatalytic water splitting and the related factors to determine the catalytic activity. The recent progress in the exploitation of MOFs for water splitting is then summarized, and strategies for designing MOF-based catalysts for electrocatalytic and photocatalytic water splitting are presented. Finally, major challenges in the field of water splitting are highlighted, and some perspectives of MOF-based catalysts for water splitting are proposed

Solid Oxide Fuel Cells with both High Voltage and Power Output by Utilizing Beneficial Interfacial Reaction

An intriguing cell concept by applying proton-conducting oxide as the ionic conducting phase in the anode and taking advantage of beneficial interfacial reaction between anode and electrolyte is proposed to successfully achieve both high open circuit voltage (OCV) and power output for SOFCs with thin-film samarium doped ceria (SDC) electrolyte at temperatures higher than 600 °C. The fuel cells were fabricated by conventional route without introducing an additional processing step. A very thin and dense interfacial layer (2–3 μm) with compositional gradient was created by in situ reaction between anode and electrolyte although the anode substrate had high surface roughness (\u3e5 μm), which is, however, beneficial for increasing triple phase boundaries where electrode reactions happen. A fuel cell with Ni–BaZr0.4Ce0.4Y0.2O3 anode, thin-film SDC electrolyte and Ba0.5Sr0.5Co0.8Fe0.2O3–δ (BSCF) cathode has an OCV as high as 1.022 V and delivered a power density of 462 mW cm−2 at 0.7 V at 600 °C. It greatly promises an intriguing fuel cell concept for efficient power generation

Mechanical behavior of spiral reinforcement recycled aggregate concrete round columns under axial compression after spraying water at high temperatures

Spiral hoops can effectively enhance the load-bearing capacity of recycled aggregate concrete columns, and the mechanical performance of such a member after experiencing fire and a fire sprinkler is very important for its application and promotion. Aiming at this problem, the mechanical behavior of spiral reinforcement recycled aggregate concrete round columns under axial compression after spraying water at high temperatures cooling was investigated. Three parameters including recycled coarse aggregate replacement ratio, temperature, and pitch of screw stirrups were taken into consideration. 26 specimens were designed for static loading test. The failure modes of regenerated concrete columns with spiral reinforcement were observed after cooling by high-temperature water spraying. The mechanical properties of specimens under different cooling modes after high temperatures were obtained and analyzed. The results indicate that the effect of the recycled aggregate replacement ratio on the performance of the specimens was mainly in terms of peak displacement. And the reduction in the spiral stirrup spacing increases the peak load and ductility coefficient of the specimens. The high temperature above 600°C has a obvious effect on the mechanical properties of the specimens. Water spray cooling can reduce the appearance of small cracks on the surface of the specimens and their peak displacement. The calculation method of bearing capacity of regenerated spiral reinforced concrete columns cooled by high-temperature water spraying was discussed

Malignant melanoma of the penis and urethra: one case report

We present a case of a patient with malignant melanoma of the glans penis and urethra, which was found in a 53-year-old man with nonhealing ulcerative penile lesion and bilateral, clinically palpable inguinal lymphadenopathies at diagnosis. A diagnostic biopsy showed the characteristics of a melanoma. We treated the patient with total penectomy and bilateral inguinal lymph node dissection. After surgery, chemotherapy with bleomycin, vincristine and cisplatin and immunotherapy with thymosin injection were started. No recurrence or metastasis occurred during the 3 years after the operation. Melanoma of the penis is very rare, and early diagnosis is important because the patient prognosis is very poor

Study on Oil Pressure Characteristics and Trajectory Tracking Control in Shift Process of Wet-Clutch for Electric Vehicles

Accurate control of oil pressure of wet-clutch is of great importance for improving shift quality. Based on dynamic models of two-gear planetary transmission and hydraulic control system, a trajectory tracking model of oil pressure was built by sliding mode control method. An experiment was designed to verify the validity of hydraulic control system, through which the relationship between duty cycle of on-off valve and oil pressure of clutch was determined. The tracking effect was analyzed by simulation. Results showed that oil pressure could follow well the optimal trajectory and the shift quality was effectively improved

Induction of cytoprotective autophagy in PC-12 cells by cadmium

AbstractLaboratory data have demonstrated that cadmium (Cd) may induce neuronal apoptosis. However, little is known about the role of autophagy in neurons. In this study, cell viability decreased in a dose- and time-dependent manner after treatment with Cd in PC-12 cells. As cells were exposed to Cd, the levels of LC3-II proteins became elevated, specific punctate distribution of endogenous LC3-II increased, and numerous autophagosomes appeared, which suggest that Cd induced a high level of autophagy. In the late stages of autophagy, an increase in the apoptosis ratio was observed. Likewise, pre-treatment with chloroquine (an autophagic inhibitor) and rapamycin (an autophagic inducer) resulted in an increased and decreased percentage of apoptosis in contrast to other Cd-treated groups, respectively. The results indicate that autophagy delayed apoptosis in Cd-treated PC-12 cells. Furthermore, co-treatment of cells with chloroquine reduced autophagy and cell activity. However, rapamycin had an opposite effect on autophagy and cell activity. Moreover, class III PI3 K/beclin-1/Bcl-2 signaling pathways served a function in Cd-induced autophagy. The findings suggest that Cd can induce cytoprotective autophagy by activating class III PI3 K/beclin-1/Bcl-2 signaling pathways. In sum, this study strongly suggests that autophagy may serve a positive function in the reduction of Cd-induced cytotoxicity

Long-Lived Charge Separation Following Pump-Energy Dependent Ultrafast Charge Transfer in Graphene/WS2_2 Heterostructures

Van der Waals heterostructures consisting of graphene and transition metal dichalcogenides (TMDCs) have recently shown great promise for high-performance optoelectronic applications. However, an in-depth understanding of the critical processes for device operation, namely interfacial charge transfer (CT) and recombination, has so far remained elusive. Here, we investigate these processes in graphene-WS$_2$ heterostructures, by complementarily probing the ultrafast terahertz photoconductivity in graphene and the transient absorption dynamics in WS$_2$ following photoexcitation. We find that CT across graphene-WS$_2$ interfaces occurs via photo-thermionic emission for sub-A-exciton excitation, and direct hole transfer from WS$_2$ to the valence band of graphene for above-A-exciton excitation. Remarkably, we observe that separated charges in the heterostructure following CT live extremely long: beyond 1 ns, in contrast to ~1 ps charge separation reported in previous studies. This leads to efficient photogating of graphene. These findings provide relevant insights to optimize further the performance of optoelectronic devices, in particular photodetection