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71.
Lead-free electroceramics represent an emerging area of research that has the potential to enable new green advances in electronics. Research has mainly focused on the development of new piezoelectric materials for replacing lead containing oxides exhibiting superior electromechanical behavior. Lead-free BiFeO3-based materials are not only the promising candidates to replace lead-based materials but also show intriguing properties which may inspire innovative material design for the next generation of lead-free piezoceramics. This review aims to highlight the current state of research and overlooked aspects in lead-free BiFeO3-based ceramics, which could be insightful in elucidating certain controversial issues. Current strategies to reduce high conductivity, influence of chemical heterogeneity on both functional properties and crystal structure, effective heat treatment procedures, and the role of pseudo-cubic structures on the enhancement of piezoelectric properties are subjects of highlighted within this review as they have a significant impact on the quality of BiFeO3-based lead-free piezoelectrics (but are often disregarded). 相似文献
72.
Dong Hyung Lee Eun Taeg Kim Hyun Been Jo Seo Yoon Hwang Nam Kyung Lee Dong Soo Suh Ki Hyung Kim 《Medicine》2022,101(17)
Rationale:Transvaginal evisceration of the small bowel is an extremely rare condition after hysterectomy, which requires urgent surgical intervention to prevent serious bowel morbidity and mortality.Patient concerns:A 65-year-old woman presented with sudden-onset severe abdominal pain and a mass protruding through the vagina. The past surgical history was significant, with an abdominal hysterectomy for cervical cancer performed 11 weeks prior to presentation.Diagnosis:Pelvic examination revealed prolapsed small-bowel loops (18-20 cm in length). Pelvic computed tomography scan confirmed the presence of transvaginal evisceration of the small bowel.Interventions:Bowel reduction and urgent laparotomy were the selected treatment approaches for a detailed inspection and thorough washing of the intrα-abdominal cavity. A Foley catheter was inserted in the emergency room, with the subject in the lithotomy position. The prolapsed bowel loops spontaneously reduced without manual reduction, and the vault defect was repaired transvaginally.Outcomes:The patient experienced no postoperative complications and remained disease-free for 9months postoperatively.Lessons:Transvaginal evisceration of the small bowel should be considered a surgical emergency. A multidisciplinary approach to prompt case management involving clinicians in gynecology, general surgery, and emergency medicine is vital for preventing serious consequences. Hysterectomy is the most frequently performed gynecological surgical procedure, and evisceration occurs most often after hysterectomy. Therefore, patients should be informed about this rare but possible hysterectomy complication. 相似文献
73.
Do Hyeon Park Chan Mi Lee Euijin Chang Chang Kyung Kang Wan Beom Park Nam Joong Kim Pyoeng Gyun Choe Myoung-don Oh 《Journal of Korean medical science》2022,37(29)
Despite the low prevalence of secondary bacterial infection in coronavirus disease 2019 (COVID-19) patients, most of them were administered antibiotic therapy empirically. However, the prognostic impact of empirical antibiotic therapy has not been evaluated. We conducted retrospective propensity score-matched case-control study of 233 COVID-19 patients with moderate to severe illnesses who required oxygen therapy and evaluated whether empirical antibiotic therapy could improve clinical outcomes. Empirical antibiotic therapy did not improve clinical outcomes including length of stay, days with oxygen requirement, the proportion of patients with increased oxygen demand, the proportion of patients who required mechanical ventilation, and overall mortality. This finding implies that routine administration of antibiotics for the treatment of COVID-19 is not essential and should be restricted. 相似文献
74.
Suk-Jae Park Ginnae Ahn Nam Ho LeeJae Woo Park You-Jin JeonYoungheun Jee 《Food and chemical toxicology》2011,49(9):2236-2242
Phloroglucinol (PG), a polyphenol compound of Eckloniacava known as brown algae abundant in Jeju island, has been proposed to exert the antioxidative and cytoprotective effects against oxidative stress. In this study, we confirmed that PG protected mice from damages caused by ionizing radiation and investigated its protection mechanism in detail. The result showed that PG increased the viability of splenocytes without cytotoxicity. Also, PG significantly enhanced the proliferation of splenocytes by limiting the increment of sub-G1 DNA contents via the inhibition of reactive oxygen species production in 2 Gy-irradiated splenocytes. In addition, PG significantly decreased DNA damage and the number of apoptotic fragments in lymphocytes against oxidative stress. Also, PG increased the counts of endogenous spleen CFUs, compared with only ionizing radiation-irradiated mice. These results demonstrate the multi-faceted protection mechanisms of PG in mice against oxidative stress caused by ionizing radiation, providing the benefit of inhibiting apoptosis and strengthening hematopoiesis. 相似文献
75.
本文报道我国西南产麻黄——丽江麻黄Ephedra likiangensis Florin、匍枝丽江麻黄E.likiangensis f.mairei(Florin)C.Y.Cheng、藏麻黄E.saxatilis Royle ex Florin、山岭麻黄E.gerardiana Wall、垫状山岭麻黄E.gerardiana Var.congesta C.Y.Cheng、矮麻黄E.minuta Florin和异株矮麻黄E.minuta var.dioeca C.Y.Cheng,以及形态组织特征较特殊的宁夏产斑子麻黄E.lepidosperma C.Y.Cheng、新疆产窄膜麻黄E.lomatolepis Schrenk,西藏产西藏中麻黄E.intermedia var.tibetica Stapf的生药形态组织学研究结果。并根据对国产麻黄的生药形态组织学的系统研究结果,分别编写了各种国产麻黄(包括13种3变种1变型)的生药性状和生药显微特征检索表。 相似文献
76.
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78.
Ki Dong Kim Dongwoo Nam Bum Sang Shim Sung‐Hoon Kim Kyoo Seok Ahn Seung‐Hoon Choi Kwang Seok Ahn 《Phytotherapy research : PTR》2014,28(3):423-431
The oncogenic PI3K/Akt/mammalian target of rapamycin (mTOR) signaling axis and its downstream effector, the ribosomal protein S6 kinase 1 (S6K1) play a key role in mediating cell survival in various tumor cells. Here, we investigated the effects of brassinin (BSN), a phytoalexin first identified as a constituent of cabbage, on the PI3K/Akt/mTOR/S6K1 activation, cellular proliferation, and apoptosis in PC‐3 human prostate cancer. BSN exerted a significant dose‐dependent cytotoxicity and reduced constitutive phosphorylation of Akt against androgen‐independent PC‐3 cells as compared to androgen‐dependent LNCaP cells. Moreover, knockdown of androgen receptor (AR) by small interfering RNA enhanced the potential effect of BSN on induction of apoptosis in LNCaP cells. BSN clearly suppressed the constitutive activation of PI3K/Akt/mTOR/S6K1 signaling cascade, which correlated with the induction of apoptosis as characterized by accumulation of cells in subG1 phase, positive Annexin V binding, TUNEL staining, loss of mitochondrial membrane potential, down‐regulation of antiapoptotic and proliferative proteins, activation of caspase‐3, and cleavage of PARP. Additionally, BSN could block broad‐spectrum inhibition of PI3K/Akt/mTOR/S6K1 axes, and aberrant Akt activation by pcDNA3‐myr‐HA‐Akt1 plasmid could not prevent the observed suppressive effect of BSN on constitutive mTOR activation. Finally, overexpression of Bcl‐2 also attenuated BSN‐mediated apoptosis in PC‐3 cells. Taken together, our findings suggest that BSN can interfere with multiple signaling cascades involved in tumorigenesis and might be provided as a potential therapeutic candidate for both the prevention and treatment of prostate cancer. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
79.
80.
Seven new beta-carboline-based metabolites, designated as eudistomins Y1-Y7 ( 1- 7), were isolated from a tunicate of the genus Eudistoma collected near Tong-Yeong City, South Sea, Korea. These new metabolites differ from previously isolated marine metabolites due to the presence of a benzoyl group attached to the beta-carboline nucleus at C-1. Eudistomins Y 1-Y 7 were evaluated for their antibacterial activity, and eudistomin Y6 exhibited moderate antibacterial activity against Gram-positive bacteria Staphylococcus epidermis and Bacillus subtilis without cytotoxicity in the MTT assay at 100 microM. 相似文献