Myricetin Improves Impaired Nerve Functions in Experimental Diabetic Rats

Diabetic peripheral neuropathy (DPN) is considered as one of the most important complications of diabetes mellitus. At present, effective treatments that might improve the damaged neurological function in DPN are sorely needed. As myricetin has been proved to possess excellent neuroprotective and antioxidant effects, it might have therapeutic potential for DPN. Therefore, the purpose of our study was to detect the potential beneficial effect of myricetin on DPN. A single dose of 50 mg/kg of streptozotocin was applied in rats for the establishment of diabetic models. Different doses of myricetin (0.5 mg/kg/day, 1.0 mg/kg/day, and 2.0 mg/kg/day) were intraperitoneally injected for 2 weeks from the 21st day after streptozotocin injection. After the final myricetin injection, behavioral, electrophysiological, biochemical, and protein analyses were performed. In the present study, myricetin significantly ameliorated diabetes-induced impairment in sensation, nerve conduction velocities, and nerve blood flow. In addition, myricetin significantly reduced the generation of advanced glycation end-products (AGEs) and reactive oxygen species (ROS), and elevated Na+, K+-ATPase activity and antioxidant activities in nerves in diabetic animals. Additional studies revealed that myricetin significantly raised the hydrogen sulfide (H2S) levels, and elevated the expression level of heme oxygenase-1 (HO-1) as well as nuclear factor-E2-related factor-2 (Nrf2) in diabetic rats. In addition, myricetin has the capability of decreasing plasma glucose under diabetic conditions. The findings in our present study collectively indicated that myricetin could restore the impaired motor and sensory functions under diabetic conditions. The Nrf2-dependent antioxidant action and the capability of decreasing plasma glucose might be the underlying mechanisms for the beneficial effect of myricetin on impaired neural functions. Our study showed the therapeutic potential of myricetin in the management of DPN

Early clinical and laboratory risk factors of intensive care unit requirement during 2004–2008 dengue epidemics in Singapore: a matched case–control study

Background: Dengue infection can result in severe clinical manifestations requiring intensive care. Effective triage is critical for early clinical management to reduce morbidity and mortality. However, there is limited knowledge on early risk factors of intensive care unit (ICU) requirement. This study aims to identify early clinical and laboratory risk factors of ICU requirement at first presentation in hospital and 24 hours prior to ICU requirement. Method: A retrospective 1:4 matched case–control study was performed with 27 dengue patients who required ICU, and 108 dengue patients who did not require ICU from year 2004–2008, matched by year of dengue presentation. Univariate and multivariate conditional logistic regression were performed. Optimal predictive models were generated with statistically significant risk factors identified using stepwise forward and backward elimination method. Results: ICU dengue patients were significantly older (P=0.003) and had diabetes (P=0.031), compared with non-ICU dengue patients. There were seven deaths among ICU patients at median seven days post fever. At first presentation, the WHO 2009 classification of dengue severity was significantly associated (P<0.001) with ICU, but not the WHO 1997 classification. Early clinical risk factors at presentation associated with ICU requirement were hematocrit change ≥20% concurrent with platelet <50 K [95% confidence-interval (CI)=2.46-30.53], hypoproteinemia (95% CI=1.09-19.74), hypotension (95% CI=1.83-31.79) and severe organ involvement (95% CI=3.30-331). Early laboratory risk factors at presentation were neutrophil proportion (95% CI=1.04-1.17), serum urea (95% CI=1.02-1.56) and alanine aminotransferase level (95% CI=1.001-1.06). This predictive model has sensitivity and specificity up to 88%. Early laboratory risk factors at 24 hours prior to ICU were lymphocyte (95% CI=1.03-1.38) and monocyte proportions (95% CI=1.02-1.78), pulse rate (95% CI=1.002-1.14) and blood pressure (95% CI=0.92-0.996). This predictive model has sensitivity and specificity up to 88.9% and 78%, respectively. Conclusions: This is the first matched case–control study, to our best knowledge, that identified early clinical and laboratory risk factors of ICU requirement during hospitalization. These factors suggested differential pathophysiological background of dengue patients as early as first presentation prior to ICU requirement, which may reflect the pathogenesis of dengue severity. These risk models may facilitate clinicians in triage of patients, after validating in larger independent studies.Published versio

Study on the Characteristics of Traction Forces Difference Asymmetric Steering Bogies

This article comes up with a new concept of applying the difference between traction forces on front and rear wheelsets to guiding control, as well as the design of a new type of structurally simple asymmetrical radial bogies, which lead to the proposition of traction forces difference-steering asymmetric radial bogies. The traction forces difference-steering asymmetric radial bogies are referred to as TFDA-bogies, in which the difference of longitudinal creep forces between front and rear wheels produces radial steering of both wheelsets. The concept of traction difference is incorporated into guiding control and bogie structure is also simplified in the form of asymmetrical radial bogies. Angle sensors are mounted to facilitate the change of electric currents of the front and rear traction motors to control the guiding mechanism so that wheelsets can adopt the radial position. With SIMPACK, the multibody dynamics analysis software, three whole vehicle models of TFDA-bogies, radial bogies, and conventional bogies are set up and comparative analyses are made on the lead wheel angle of attack, lead wheel lateral force, lead wheel friction power, and total vehicle friction power under idle running condition and traction condition, respectively. Results show that TFDA-bogies are radial bogies with simplified structure

Levitation Stability and Hopf Bifurcation of EMS Maglev Trains

This paper analyzed the mechanical characteristics of single electromagnet system and elastic track beam of EMS maglev train and established a five-dimensional dynamics model of single electromagnet-track beam coupled system with classical PD control strategy adopted for its levitation system. Then, based on the Hurwitz criterion and the high-dimensional Hopf bifurcation theory, the stability of the coupled system is analyzed; the existence of the Hopf bifurcation is discussed and the bifurcation direction and the stability of the periodic solution are determined with levitation control feedback coefficient kp as the bifurcation parameter; and numerical simulation is conducted to verify the validity of the theoretical analysis results. The results show that the Hurwitz algebra criterion can directly determine the eigenvalues and symbols of the dynamics system to facilitate the analysis on the stability of the system and the Hopf bifurcation without the necessity of calculating the specific eigenvalues; supercritical Hopf bifurcation will occur under the given parameters, that is, when kp<kp0, the real-time system is asymptotically stable, yet Hopf bifurcation occurs as kp increases gradually beyond kp0, with the stability of the system lost and a stable limit cycle branched

Polymorphic cobalt sulfide-embedded graphene foam with ultralong cycling and ultrafast rate capability for potassium-ion batteries

Potassium-ion batteries (KIBs) attract growing attention due to their low price and abundant resources. However, the main drawback is the large-sized potassium ions, which results in a lack of superior capacity and desirable stable materials. We herein propose the Co9S8/GF nanocomposite synthesized by a solvothermal route followed by heat treatment under the reduction atmosphere with the CoS/GF nanocomposite as the control group. The as-synthesized Co9S8 has a typical morphology of vertically arranged uniform nanosheet arrays. The Co9S8/GF nanocomposite electrode delivers a capacity of 345.65 mAh·g-1 after 600 cycles at 500 mA·g-1 and even 343.06 mAh·g-1 after 1360 cycles at 5000 mA·g-1 in KIBs. Besides, the discharge capacity can reach 461.05 mAh·g-1 after the current increases to 5000 mA·g-1 and a reversible capacity of 578.40 mAh·g-1 when the current density recovers to 250 mA·g-1 again. At last, the charge storage behaviors are mainly discussed, and the unique structure can suffer the volumetric change, especially at high current density, which opens up a novel and effective way to build the embedded porous structure for the next-generation KIB technology.This work was supported by the Fundamental Research Funds for the Central Universities (Grant No. D5000210522), China Postdoctoral Science Foundation (Grant No. 2021M702665), Natural Science Foundation of Shaanxi Province (Grant No. 2022JQ-482), Guangdong Basic and Applied Basic Research Foundation (Grant No. 2021A1515111155), Jiangsu Planned Projects for Postdoctoral Research Funds, and Basic Research Programs of Taicang (Grant No. TC2021JC01)

Metformin Promotes Axonal Regeneration and Functional Recovery in Diabetic Rat Model of Sciatic Nerve Transection Injury

In our previous study, metformin was able to promote nerve regeneration after sciatic nerve crushing in rats under diabetic conditions. However, a crush injury also has a strong ability to spontaneously recover. Therefore, in our present study, a model of transection injury of the sciatic nerve in diabetic rats was utilized to detect whether metformin could still promote nerve regeneration. Diabetes was induced via an injection of 50 mg/kg of streptozotocin in rats. After transection injury of the sciatic nerve, the rats were randomly divided into a high-dose metformin group (500 mg/kg/d), mid-dose metformin group (200 mg/kg/d), low-dose metformin group (30 mg/kg/d) and control group (normal saline). The metformin or normal saline was intraperitoneally injected for 4 weeks. Then, behavioral, electrophysiological and morphometric analyses were performed. The results showed that metformin could significantly promote functional restoration and axonal regeneration of the sciatic nerve after transection injury under diabetic conditions. Furthermore, high doses and middle doses of metformin presented more of this ability than a low dose of metformin. In conclusion, metformin is able to accelerate sciatic nerve repair after transection injury under diabetic conditions, showing the therapeutic potential of metformin in the management of nerve injuries during diabetes mellitus

Unequal impact of climate warming on meat yields of global cattle farming

Abstract Climate warming affects global livestock productivity. The meat yield from cattle farming (cattle meat per animal) represents livestock productivity at the individual level. However, the impact of warming on cattle meat yield at a global scale is not well understood. In this study, we combine country-level data on the annual meat yield from cattle farming and socioeconomic data from 1961 to 2020 with climate projections from General Circulation Models. The findings show that cattle meat yield increases as temperatures rise from low to medium and then decreases when annual average temperatures exceed 7 °C; this repose is pronounced in the grassland-based livestock system. Further, we show that warming creates unequal impacts between high- and low-income countries due to the divergent baseline temperature conditions. Future warming aggravates these unequal burdens between countries, with the most pronounced effects observed under the upper-middle emissions scenario

Sol–Gel Routes toward Ceramic Nanofibers for High-Performance Thermal Management

Ceramic-based nanofiber materials for high-performance thermal management have drawn increasing attention owing to their high-temperature resistance, efficient thermal insulation, superior mechanical flexibility, as well as excellent physical–chemical stability. We present an overview of the ceramic-based nanofiber obtained by sol–gel routes for high-performance thermal management, including the materials, the fabrication methods of the sol–gel route, and their application for thermal management. We first provide a brief introduction to the ceramic-based nanofibers. The materials and fabrication methods of the sol–gel route are further discussed in the second part, including the kinds of nanofibers such as oxide, carbide, and nitride, and the methods such as centrifugal spinning, electrospinning, solution blow spinning, and self-assembly. Finally, their application for thermal management is further illustrated. This review will provide some necessary suggestions to researchers for the investigation of ceramic-based nanofibers produced with the sol–gel route for thermal management