Search

High‐Ni layered oxide cathodes hold a great promise for fabricating high‐energy lithium‐ion batteries. However, the oxygen evolution during cycling is a crucial factor in the structure deterioration, potential change, and capacity decay of cathodes, limiting the commercial application of high‐Ni (Ni > 0.9) layered oxides in batteries. Herein, we demonstrate a feasible approach to enhance the stability of oxygen framework, through the surface oxygen immobilization with yttrium and bulk oxygen stabilization with aluminum in high‐Ni layered oxides. As expected, benefiting from the oxygen‐stabilized framework, the bulk structure deterioration, and interfacial parasitic reaction are mitigated obviously during battery operation, along with the improved thermal stability of cathode. Correspondingly, the as‐prepared high‐Ni oxide delivers high reversible capacity, impressive cycle ability, and low potential polarization upon cycling. Such significant improvement on the electrochemical performance is primarily attributed to the strong oxygen affinities of both yttrium at the surface layer and aluminum in the bulk, which synergistically stabilizes the oxygen framework of high‐Ni oxide via raising the energy barrier for oxygen evolution. Therefore, building the stable oxygen framework is critical for enhancing the energy density output, cycle operation, and thermal stability of high‐Ni oxide cathodes. [ABSTRACT FROM AUTHOR]

Lithium‐metal (Li) electrode has been regarded as an excellent option to increase the energy density of next‐generation secondary batteries due to its low electrochemical potential and ultrahigh theoretical capacity. However, Li electrodes suffer from poor Coulombic efficiency (CE) and uneven lithium deposition issues during cycling that severely restrain its application. Herein, ammonium perfluoro(2‐methyl‐3‐oxahexanoate) (APFA), a pragmatic anionic surfactant, is introduced as an electrolyte additive to regulate the deposition behavior of lithium. Different from the conventional sacrificial additives that reinforce solid electrolyte interphase (SEI) layers on Li electrodes, the PFA− anions are mainly adsorbed on the Li surface, which improves the electron transfer step kinetics due to the ψ1 effect. The introduction of APFA in the electrolyte promises homogeneous and highly dense lithium deposition and the LiLi symmetric cell with APFA can operate over 4000 h with excellent stability and low polarization. This work provides a facile and promising strategy for fabricating stable Li anode for high‐energy‐density secondary batteries. [ABSTRACT FROM AUTHOR]

Introduction: L‐glutamine is an antioxidant that plays a role in a variety of biochemical processes. Given that oxidative stress is a key component of stroke pathology, the potential of L‐glutamine in the treatment of ischemic stroke is worth exploring. Aims: In this study, we investigated the effect and mechanisms of action of L‐glutamine after cerebral ischemic injury. Results: L‐glutamine reduced brain infarct volume and promoted neurobehavioral recovery in mice. L‐glutamine administration increased the expression of heat‐shock protein 70 (HSP70) in astrocytes and endothelial cells. Such effects were abolished by the coadministration of Apoptozole, an inhibitor of the ATPase activity of HSP70. L‐glutamine also reduced oxidative stress and neuronal apoptosis, and increased the level of superoxide dismutase, glutathione, and brain‐derived neurotrophic factor. Cotreatment with Apoptozole abolished these effects. Cell culture study further revealed that the conditioned medium from astrocytes cultured with L‐glutamine reduced the apoptosis of neurons after oxygen‐glucose deprivation. Conclusion: L‐glutamine attenuated ischemic brain injury and promoted functional recovery via HSP70, suggesting its potential in ischemic stroke therapy. [ABSTRACT FROM AUTHOR]

Summary: Introduction: Dl‐3‐N‐butylphthalide (NBP), a small molecule drug used clinically in the acute phase of ischemic stroke, has been shown to improve functional recovery and promote angiogenesis and collateral vessel circulation after experimental cerebral ischemia. However, the underlying molecular mechanism is unknown. Aims: To explore the potential molecular mechanism of angiogenesis induced by NBP after cerebral ischemia. Results: NBP treatment attenuated body weight loss, reduced brain infarct volume, and improved neurobehavioral outcomes during focal ischemia compared to the control rats (P < 0.05). NBP increased the number of CD31+ microvessels, the number of CD31+/BrdU+ proliferating endothelial cells, and the functional vascular density (P < 0.05). Further study demonstrated that NBP also promoted the expression of vascular endothelial growth factor and angiopoietin‐1 (P < 0.05), which was accompanied by upregulated sonic hedgehog expression in astrocytes in vivo and in vitro. Conclusion: NBP treatment promoted the expression of vascular endothelial growth factor and angiopoietin‐1, induced angiogenesis, and improved neurobehavioral recovery. These effects were associated with increased sonic hedgehog expression after NBP treatment. Our results broadened the clinical application of NBP to include the later phase of ischemia. [ABSTRACT FROM AUTHOR]

Background. Acne is not only a skin condition but also a cardinal component of many systemic diseases or syndromes. This study was aimed to investigate the prevalence of acne in reproductive-age women in Sichuan province, China, and to evaluate acne as a skin problem alone or a symptom of gynecological/endocrinological disease. Methods. From October 2008 to September 2009, 1043 reproductive-age women from 19 to 45 years of age from seven communities of three districts in Sichuan province completed a standardized questionnaire and a physical examination. Acne was classified using the Pillsbury scale, and hirsutism was assessed using a modified Ferriman–Gallwey method. Diagnosis of polycystic ovary syndrome (PCOS) was based on the 2003 Rotterdam criteria. Some endocrine and metabolic markers were detected for the women diagnosed with PCOS related to acne and the control group. Results. The prevalence of acne was 32.5%, and the highest prevalence (9.6%) was seen in the 19–24-year-old age group. Prevalence among women eating dessert frequently, exercising seldom, or among sedentary workers was significantly higher in the acne group (14.1%, 55.6%, and 51.3%, respectively) than in the nonacne group (10.8%, 45.7%, and 35.5%; all P<0.05). The prevalence of oligomenorrhea and hirsutism in the acne group (17.6%, 24.7%) was significantly higher than in the nonacne group (8.6%, 15.1%; both P<0.05). Among the participants with acne, 64.3% had acne alone, 18.3% were diagnosed with hyperandrogenism, and 17.4% were diagnosed with PCOS. The level of serum androstendione in the group of PCOS (10.98±3.12 nmol/L) was significantly higher than that in the control group (8.85±3.09nmol/L) (P<0.05). Conclusion. When reproductive-age women with acne are encountered in gynecology–endocrinology or dermatology clinics, physicians should consider evaluating them from PCOS, hyperandrogenism, or acne alone. [ABSTRACT FROM AUTHOR]