Left and right-handed helical barium titanate nanotubes are prepared with the impregnation of Ba（OH）2 into single-handed helical titania nanotubes.Wide angle X-ray diffraction pattern and ...transmission electron microscopy image indicate that they are constructed by nanoparticles with a partially crystalline structure.The diffuse reflertance circular dichroism spectra indicate that they exhibit optical activity which was proposed to originate from chiral defects on the inner surfaces of the nanotubes.Both the dielectric constant and tanδ decrease with increasing the frequency.At 10 and 100 Hz,one dielectric constant peak at 9.6℃ and one tanδ peak at 5.0℃ are observed at -120℃ to 180℃.
Herein, for the first time, quaternary resistive memory based on an organic molecule is achieved via surface engineering. A layer of poly(3,4-ethylenedioxythiophene)–poly(styrenesulfonate) ...(PEDOT–PSS) was inserted between the indium tin oxide (ITO) electrode and the organic layer (squaraine, SA-Bu) to form an ITO/PEDOT–PSS/SA-Bu/Al architecture. The modified resistive random-access memory (RRAM) devices achieve quaternary memory switching with the highest yield (∼41%) to date. Surface morphology, crystallinity, and mosaicity of the deposited organic grains are greatly improved after insertion of a PEDOT–PSS interlayer, which provides better contacts at the grain boundaries as well as the electrode/active layer interface. The PEDOT–PSS interlayer also reduces the hole injection barrier from the electrode to the active layer. Thus, the threshold voltage of each switching is greatly reduced, allowing for more quaternary switching in a certain voltage window. Our results provide a simple yet powerful strategy as an alternative to molecular design to achieve organic quaternary resistive memory.
Wenshen Zhuanggu Formula (WSZG), a traditional Chinese medicine (TCM) empirical prescription, has been used to treat the patients with breast cancer bone metastasis as an adjuvant in clinical ...practice. To explore the anti-metastatic activity and potential mechanisms of WSZG-containing serum (WSZG-CS) on highly bone-metastatic human breast cancer MDA-MB-231BO cells.
MDA-MB-231BO cells were cultured alone or co-cultured with bone marrow-derived mesenchymal stem cells (BMSCs). Invasion assays were carried out in Matrigel-coated Transwell chambers. CC chemokine 5 (CCL5) and interleukin (IL)-17B secretion levels were detected by ELISA. CCR5 and IL-17BR protein expression levels were determined by immunocytochemistry and Western blot analysis.
Compared with control serum, WSZG-CS significantly inhibited BMSC induced MDA-MB-231BO breast cancer cell invasion, reduced CCL5 and IL-17B levels in co-culture supernatants, and downregulated CCR5 and IL-17BR protein expression in breast cancer cells co-cultured with BMSCs.
WSZG-CS exerts an anti-metastatic activity against MDA-MB-231BO breast cancer cells, due to its ability to mitigate the interaction between BMSCs and breast cancer cells mediated via the CCL5/CCR5 and IL-17B/IL-17BR signaling pathways.
Wenshen Zhuanggu Formula (WSZG) exerted an anti-metastatic activity against MDA-MB-231BO breast cancer cells, due to its ability to mitigate the interaction between BMSCs and breast cancer cells mediated via the CCL5/CCR5 and IL-17B/IL-17BR signaling pathways. Display omitted
Objective Solar ultraviolet （UV） radiation is an important environmental factor that affects human health. The understanding of diurnal variations of UV radiation at anatomical sites may be helpful ...in developing ways to protect humans from the harmful effects of UV radiation. Methods In order to characterize the diurnal variations, the UV exposure values were measured at 30 min intervals by using Solar-UV Sensors and a rotating manikin in Shenyang city of China （41°51＇N, 123°27%）. Measurement data for four representative days （in each of the four seasons respectively） were analyzed. Results The diurnal variations in solar UV radiation at the shoulder, the forehead and the chest were similar to those associated with a horizontal control measurement. However, the diurnal variations at the eye and the cheek exhibited bimodal distributions with two peaks in spring, summer and autumn, and a unimodal distribution in winter. The UV exposure peaks at the eye and the cheek were measured at solar elevation angles （SEA） of about 30° and 40°, respectively. Conclusion The protection of some anatomical sites such as the eye from high UV exposure should not be focused solely on the periods before and after noon, especially in the places and seasons with high SEA.
Abstract
Memristors are a new type of circuit element with a resistance that is tunable to discrete levels by a voltage/current and sustainable after removal of power, allowing for low‐power ...computation and multilevel information storage. Many organic‐inorganic lead perovskites are reported to demonstrate memristive behavior, but few have been considered for use as a multilevel memory; also, their potential application has been hindered by the toxicity of lead ions. In this article, lead‐free perovskite MASnBr
3
was utilized in memristors for quaternary information storage. Indium tin oxide (ITO)/MASnBr
3
/Au memristors were fabricated and showed reliable memristive switching with well‐separated ON/OFF states of a maxima resistance ratio of 10
2
to 10
3
. More importantly, four resistive states can be distinguished and repeatedly written/read/erased with a retention time of 10
4
seconds and an endurance of 10
4
pulses. By investigating the current‐electrode area relationship, Br distribution in the ON/OFF states by in situ Raman and scanning electron microscopy, and temperature‐dependent current decay, the memristive behavior was explicitly attributed to the forming/breaking of conductive filaments caused by the migration of Br
−
under an electric field. In addition, poly(ethylene terephthalate)‐ITO/MASnBr
3
/Au devices were found to retain their multiresistance state behavior after being bent for 1000 times, thus demonstrating good device flexibility. Our results will inspire more lead‐free perovskite work for multilevel information storage, as well as other memristor‐based electronics.
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AIM： To investigate the prevalence of and risk factors for lens opacities in populations living at two different altitudes in China.·METHODS： A total of 813 subjects aged ≥40y in Lhasa（Tibet ...Autonomous Region, China. Altitude： 3658 m） and Shaoxing（Zhejiang Province, China. Altitude： 15 m） were underwent eye examinations and interviewed in this cross-sectional study. Participants＇ lens opacities were graded according to the Lens Opacities Classification System II（LOCS II） and the types of opacities with LOCS II scores ≥2 were determined. Univariate and stepwise logistic regression were used to evaluate the associations of independent risk factors with lens opacities.· RESULTS： Lens opacities were significantly more prevalent in the high-altitude than in the low-altitude area（χ2=10.54, P 〈0.001）. Lens opacities appear to develop earlier in people living at high than at low altitude. The main types of lens opacity in Lhasa and Shaoxing were mixed（23.81%） and cortical（17.87%）,respectively. Independent risk factors associated with all lens opacities were age, ultraviolet（UV） radiation exposure,and educational level. Compared with participants aged40-49 y, the risk of lens opacities increased gradually from 2 to 85 times per 10 y odds ratio（OR）=2.168-84.731,P 〈0.05）. The risk of lens opacities was about two times greater in participants with the highest UV exposure than in those with the lowest exposure（OR=2.606, P =0.001）.Educational level was inversely associated with lensopacities; literacy deceased the risk by about 25%compared with illiteracy（OR=0.758, P =0.041）.·CONCLUSION： Old age, higher UV exposure and lower educational level are important risk factors for the development of lens opacities. Lens opacities are more prevalent among high-altitude than low-altitude inhabitants.
·AIM: To establishtherat model of streptozotocin (STZ)- induced diabetic retinopathy (DR), which is the most common cause of visual loss and blindness in patients with diabetes, and observe the gene ...expression of vascular endothelial growth factor (VEGF) and its receptors during the development of DR. ·METHODS: A rat model of diabetes was established by intraperitoneal injection of STZ. The diabetic rats were housed for 2, 3 and 4 months after the development of diabetes. Retinal histopathological observation was performed. The retinal vessels were observed by immunofluorescence staining by CD31. The mRNA expression of VEGF, VEGF receptor 1 and 2 (VEGFR1/2) in rat retina was detected by reverse transcription - polymerase chain reaction (RT-PCR) analysis. · RESULTS: Retinal histopathological observation showed the morphological changes of inner nuclear layer (INL) and outer nuclear layer (ONL) at any time -point, and also demonstrated the increased new vessels at both 3, 4 months after the development of diabetes. The CD31 staining results showed that the number of vessels was increased in the retinas of diabetic rats at both 3 and 4 months after the development of diabetes. As compared to the normal rats, the mRNA expression of VEGF was increased in retinas of diabetic rats at 3 months after the development of diabetes, while VEGFR1 and VEGFR2 mRNA expression was increased at 2, 3 and 4 months after the development of diabetes.·CONCLUSION:Takentogether,ourresultsdemonstrated that DR was occurred at 3 months after the development of diabetes, and the mRNA expression of VEGF, VEGFR1 and VEGFR2 were increased in the process of DR. The present study further evidenced the involvement of VEGF and its receptors in the process of DR. ·
Lower Cretaceous black shales in coastal southeastern China are of significance to the geological study of the Tethys and Pacific realms and to hydrocarbon exploration of southeastern China and East ...China Sea. However, the stratigraphic correlation, distribution patterns and hydrocarbon potential of the black shales have not been well constrained so far. In this study, the zircon UePb ages, organic petrologic and geochemical analyses were performed for representative outcrop sections in the region. Zircon UePb ages demonstrate that the Lower Cretaceous black shales in coastal southeastern China can be divided into two regional-scale sets. The first set was deposited during the early stage of the Early Cretaceous（K_1~1, BerriasianeHauterivian）. The second set was deposited during the late stage of the Early Cretaceous（K_1~2）, and might extend to the Taiwan Strait. Detailed organic geochemical analyses including organic matter abundance, type and maturity of the Lower Cretaceous black shales demonstrate that the organic matter abundance of the sources reached medium to good quality by the hydrocarbon source rock standards, and the average TOC values and the chloroform bitumen ＂A＂ of the K_1~1 black shales are higher. The type of organic matter is mainly type III, type II can also be found from the K_1~2 black shales. The thermal maturity of most samples is high to overmature. A relatively comprehensive hydrocarbon resource evaluation indicates that favorable regions are in the northern Guangdong Province for the K_1~1 and in the coastal region of Zhejiang Province and the westernFujian Province for the K_1~2. Sedimentology studies on the Shipu section for the K_1~1 black shales illuminated that the K_1~2 black shales in coastal southeastern China were mainly deposited during transgressive period. The relative sea level changes controlled the sequential development pattern of the K_1~2 black shales.
A novel up-converting phosphor,Na_xAl_yF_（x＋3y）/CaF2（0.3 〈 x 〈 0.5,0 〈 y 〈 0.1） composite,is prepared by a hydrothermal process at 180°C and an annealing treatment at 500℃.X-ray diffraction（XRD） ...pattern indicates that Na_xAl_yF_（x＋3y）/CaF_2 is a composite consisting of NaF,Na_3 AlF_6,and CaF_2.The up-conversion luminescence properties of this phosphor are investigated by fluorescence spectrometer.Results show that Na_xAl_yF_（x＋3y）/CaF_2 exhibits visible-to-ultraviolet up-conversion luminescence properties.The emission peaks at 316 and 336 nm are observed when excited by 610 nm,the luminescence lifetime of the emissions is great than 18 ms,and the internal fluorescence quantum yield is 4.2%.Additionally,the luminescent mechanism of this phosphor is also mentioned.
Staphylococcus aureus is associated with a variety of invasive infection; typically, these infections occur as sepsis, osteomyelitis, endocarditis, and arthritis. China has a relatively high ...incidence of invasive S. aureus disease in children.1 The present study aimed to provide the demographics, clones, and the antimicrobial susceptibility of S. aureus that cause invasive infection in Chinese children.
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