2,873 research outputs found
Quantum memory and non-demolition measurement of single phonon state with nitrogen-vacancy centers ensemble
In diamond, the mechanical vibration induced strain can lead to interaction
between the mechanical mode and the nitrogen-vecancy (NV) centers. In this
work, we propose to utilize the strain induced coupling for the quantum
non-demolition (QND) single phonon measurement and memory in diamond. The
single phonon in a diamond mechanical resonator can be perfectly absorbed and
emitted by the NV centers ensemble (NVE) with adiabatically tuning the
microwave driving. An optical laser drives the NVE to the excited states, which
have much larger coupling strength to the mechanical mode. By adiabatically
eliminating the excited states under large detuning limit, the effective
coupling between the mechanical mode and the NVE can be used for QND
measurement of the single phonon state. Under realistic experimental
conditions, we numerically simulate the scheme. It is found that the fidelity
of the absorbing and emitting process can reach a much high value. The overlap
between the input and the output phonon shapes can reach .Comment: 7 pages, 3 figure
Astrocytic expression of Parkinson's disease-related A53T α-synuclein causes neurodegeneration in mice
<p>Abstract</p> <p>Background</p> <p>Parkinson's disease (PD) is the most common movement disorder. While neuronal deposition of α-synuclein serves as a pathological hallmark of PD and Dementia with Lewy Bodies, α-synuclein-positive protein aggregates are also present in astrocytes. The pathological consequence of astrocytic accumulation of α-synuclein, however, is unclear.</p> <p>Results</p> <p>Here we show that PD-related A53T mutant α-synuclein, when selectively expressed in astrocytes, induced rapidly progressed paralysis in mice. Increasing accumulation of α-synuclein aggregates was found in presymptomatic and symptomatic mouse brains and correlated with the expansion of reactive astrogliosis. The normal function of astrocytes was compromised as evidenced by cerebral microhemorrhage and down-regulation of astrocytic glutamate transporters, which also led to increased inflammatory responses and microglial activation. Interestingly, the activation of microglia was mainly detected in the midbrain, brainstem and spinal cord, where a significant loss of dopaminergic and motor neurons was observed. Consistent with the activation of microglia, the expression level of cyclooxygenase 1 (COX-1) was significantly up-regulated in the brain of symptomatic mice and in cultured microglia treated with conditioned medium derived from astrocytes over-expressing A53T α-synuclein. Consequently, the suppression of COX-1 activities extended the survival of mutant mice, suggesting that excess inflammatory responses elicited by reactive astrocytes may contribute to the degeneration of neurons.</p> <p>Conclusions</p> <p>Our findings demonstrate a critical involvement of astrocytic α-synuclein in initiating the non-cell autonomous killing of neurons, suggesting the viability of reactive astrocytes and microglia as potential therapeutic targets for PD and other neurodegenerative diseases.</p
2,4-Dibromo-6-tert-butylbenzene-1,3-diol
In the title compound, C10H12Br2O2, a multiply substituted bromoarene, the C—C—C angles within the aromatic ring are in the range 115.7 (7)-122.4 (7)°. In the crystal, molecules are linked by O—H⋯O hydrogen bonds, but no π–π stacking is observed
Reduction of graphene oxide by an in-situ photoelectrochemical method in a dye-sensitized solar cell assembly
Reduction of graphene oxide [GO] has been achieved by an in-situ photoelectrochemical method in a dye-sensitized solar cell [DSSC] assembly, in which the semiconductor behavior of the reduced graphene oxide [RGO] is controllable. GO and RGO were characterized by X-ray photoelectron spectroscopy, Raman spectroscopy, high-resolution transmission electron microscope, and Fourier-transform infrared spectroscopy. It was found that the GO film, which assembled in the DSSC assembly as the counter electrode, was partly reduced. An optimized photoelectrochemical assembly is promising for modulating the reduction degree of RGO and controlling the band structure of the resulting RGO. Moreover, this method appeared to be a green progress for the production of RGO electrodes
阿爾泰哈巴河群的沉積時代及其構造背景
Habahe Group mainly consists of elastic sediments, which widely distribute in the Chinese Altai and can provide important constraints on the tectonic evolution of the Central Asian Orogenic Belt (CAOB). However, there are different opinions about its deposition time and tectonic background. Previous studies suggested that the Habahe Group formed in Sinian to Mid-Ordovician or Mid- to Late Ordovician in a passive continental margin. On the other hand, recent geological investigations reveal a long lasting subduction-related setting in the Chinese Altai at least since Cambrian. The current geochronological study for detrital zircons from the Habahe Group reveals that the detrital zircons of individual samples, irrespective of their lithological and metamorphic differences, all show similar age patterns, with the early Paleozoic ( 206Pb/ 238U age = 463 ± 542Ma) grains predominating. The youngest detrital zircons from different samples display similar ages (ca. 470Ma), which may reflect the maximum deposition time of the Habahe Group. Dating of growth rim of detrital zircons from migmatite yielded a Mid-Devonian age (384 ± 6Ma), which was coeval with intrusion of Early to Mid-Devonian granitic plutons in the area and clearly indicates the minimum deposition time of the Hababe Group. Therefore, the deposition time of the Habahe Group can be constrained to be Mid-Ordovician to Early Devonian. Zircon U Pb dating results indicate that the detrital zircons of the Habahe Group are dominated by early Paleozoic grains, with small proportion formed in Precambrian. The early Paleozoic detrital zircons are mostly magmatic in origin, and their less rounded shapes indicate a limited transportation. The age and morphological characteristics of the detrital zircons are consistent with those of detrital zircons in active tectonic settings and indicate that the Chinese Altai was under an active continental margin environment during the Early Paleozoic.
北疆阿爾泰造山帶的哈巴河群變質碎屑巖分布廣泛,其沉積時代和構造環境對于認識中亞造山帶的演化歷史有重要意義。早期研究認為哈巴河群沉積于震旦紀—中奧陶世時期,形成于被動大陸邊緣構造環境。而最近有學者根據中亞造山帶的地質演化背景提出,阿爾泰形成于活動陸緣構造環境。對哈巴河群中碎屑鋯石的年代學研究表明,不同巖性或變質程度不同的樣品碎屑鋯石主要類群具有相似的年齡分布特征,其206Pb/238U 年齡主要介于463~542Ma 之間。在這些樣品中, 最年輕的碎屑鋯石年齡均集中于470Ma 左右,代表了碎屑沉積的時代下限。而哈巴河群混合巖樣品中碎屑鋯石增生邊形成于中泥盆世晚期(384±6Ma),與侵入該群的早古生代花崗巖的年齡十分接近,大致反映了哈巴河群碎屑巖沉積時代的上限,因此哈巴河群的沉積時代應在早泥盆世—中奧陶世之間。鋯石的形態和內部結構特征顯示哈巴河群的年輕碎屑鋯石類群(463~542Ma)主要為巖漿鋯石,其磨圓度較差,而且在比例上遠高于前寒武紀碎屑鋯石。上述特點與活動大陸邊緣碎屑鋯石類群分布特征完全一致,反映阿爾泰在中奧陶世至早泥盆世可能處于活動大陸邊緣構造環境。postprin
Petrogenesis of the Permian Intermediate-Mafic Dikes in the Chinese Altai, Northwest China: Implication for a Postaccretion Extensional Scenario
published_or_final_versio
The effect of bioequivalent radiation dose on survival of patients with limited-stage small-cell lung cancer
Perceptions, behaviours and attitudes towards smoking held by the male partners of Chinese pregnant women:a qualitative study
Abstract Background Direct associations of tobacco exposure during pregnancy with pregnancy complications and adverse birth outcomes have been proven. Previous studies suggest that expecting a child provides a valuable opportunity to promote behavioural changes, such as smoking cessation, among the male partners of pregnant women. Thorough understandings of Chinese expectant fathers’ smoking behaviour during the transition to fatherhood is a prerequisite to the development of appropriate interventions to facilitate smoking cessation. This study aimed to explore the perceptions, behaviours and attitudes related to smoking among male partners of pregnant women in China. Methods A descriptive phenomenological approach was adopted. A purposive sample of expectant fathers aged 18 years or older who had a tobacco use history within the past year were recruited at obstetrics and gynaecology clinics and invited to participate in one-to-one, 20–30-min semi-structured interviews. The data analysis followed Colaizzi’s descriptive phenomenological method. Results Twenty-five expectant fathers were interviewed. Four themes were generated: 1) the benefits of smoking and respondents’ misperceptions of the impact of smoking and SHS and neglectful attitude of the impact of smoking, which were given as the major reasons for continuing to smoke; 2) factors contributing to smoking cessation, including concern for the potential health impact of continued smoking on the pregnant partner and baby, the role of being father, and the encouragement to quit from family members; and 3) perceived barriers to smoking cessation, including withdrawal symptoms or cigarette cravings, absence of smoking cessation support, and increasing stress. Conclusion This study provides a comprehensive understanding of the perception, behaviours, and attitudes related to smoking among Chinese expectant fathers. The findings of this study can guide healthcare professionals and policymakers in combining the distribution of educational information about the hazards of SHS for maternal and neonatal health with smoking cessation assistance for expectant fathers through policy initiatives and other types of incentives and programmes targeted to enhance smoking cessation among this population. Trial registration Prospectively registered at clinicaltrial.org ( NCT03401021 ) on 8 Jan 2018
- …