High-voltage energy-storage devices are quite commonly needed for robots and dielectric elastomers. This paper presents a flexible high-voltage microsupercapacitor (MSC) with a planar in-series architecture for the first time based on laser-induced graphene. The high-voltage devices are capable of supplying output voltages ranging from a few to thousands of volts. The measured capacitances for the 1, 3, and 6 V MSCs were 60.5, 20.7, and 10.0 μF, respectively, under an applied current of 1.0 μA. After the 5000-cycle charge-discharge test, the 6 V MSC retained about 97.8% of the initial capacitance. It also was recorded that the all-solid-state 209 V MSC could achieve a high capacitance of 0.43 μF at a low applied current of 0.2 μA and a capacitance of 0.18 μF even at a high applied current of 5.0 μA. We further demonstrate the robust function of our flexible high-voltage MSCs by using them to power a piezoresistive microsensor (6 V) and a walking robot (>2000 V). Considering the simple, direct, and cost-effective fabrication method of our laser-fabricated flexible high-voltage MSCs, this work paves the way and lays the foundation for high-voltage energy-storage devices.
Lipopolysaccharide-induced nitric oxide and the protease prolyl oligopeptidase (EC 3.4.21.26) have been proposed as targets for the treatment of cognitive disturbances such as dementia. In this study, nine triterpenoids isolated from the roots of Sanguisorba officinalis, including arjunic acid (1), rosamultic acid (2), haptadienic acid (3), 1β-hydroxyeuscaphic acid (4), euscaphic acid (5), tormentic acid (6), pomolic acid (7), ursolic acid (8), and oleanolic acid (9), were tested in vitro for their inhibitory activities on lipopolysaccharide-induced nitric oxide in N9 microglia cells and on prolyl oligopeptidase. Among them, 7 exhibited the strongest inhibitory activity on lipopolysaccharide-induced nitric oxide (IC50, 21.9 µM), while 8 and 9 exhibited a significant prolyl oligopeptidase inhibitory activity (IC50 18.1 and 24.0 µM, respectively). The results could provide a clue that these triterpenoids are responsible for the reported neuro-protective effect of S. officinalis.
This paper focuses on the detection of land cover and thermal environmental change over 20 years in Beijing using TM data collected on 17 June, 1991, and 8 June, 2011, respectively. For observing the urban expansion and thermal environment change in the whole Beijing governmental region, the central urban area and satellite towns were firstly recognized and detected, and then the central urban areas was divided into 5 areas based on the ring roads. After image mosaicking, masking and clipping, sample data of land cover types as water bodies, green land, bare land, construction land, farm land, and forest were collected and trained. Classification was performed using object-based support vector machine algorithm. Accuracy assessment of the classification results was conducted according to ground truth of regions of interest. The conversion matrix and band math were used to detect the land cover and thermal environment change respectively from 1991 to 2011. The results showed that, over the last 20 years, the central urban size was 5 times larger than before, construction land increased, and farm land and water bodies decreased, especially for areas outside the third ring road. Besides, UHI intensity in nearly 60% of the areas within the sixth ring road increased by more than 4 degree, and only 2% of the areas decreased. Both are consistent with the real status of the rapid development of economy and urbanization in Beijing.
In order to establish an effective and quick method for screening potential bioactive compounds in Traditional Chinese Medicines (TCMs), hepatocytes were employed for extracting either bifendate, a clinical medicine for liver diseases, or chemicals in Herba Artemisiae Scopariae (A. Scopariae), a commonly used traditional Chinese medicine for remedying liver diseases such as hepatitis induced by viruses, chemicals or alcohol. After hepatocyte extraction the compounds were analyzed by HPLC, therefore this method was referrred to as hepatocyte extraction conjugated with HPLC (HE-HPLC). In the first part of this study, HE-HPLC showed that bifendate was extracted by hepatocytes and detected by HPLC-DAD which indicated the feasibility of this method. Then in the second part of the study, the potential active components in the A. scopariae extract were studied using HE-HPLC. Six chemicals in the A. scopariae extract, which could bind to hepatocytes in vitro, were detected by HPLC-DAD and three were identified as 7-hydroxy-coumarin (7-OH-C), capillartemisin A and 7-methoxy-coumarin, respectively. In vitro assays showed that 7-OH-C protected HL-7702 hepatocytes from H2O2 injury. The results indicated that these compounds could be extracted by hepatocytes, could be detected by HPLC and more importantly were bioactive. It is suggested that HE-HPLC is a useful method for screening potent active components in Chinese medicines used to treat liver diseases.
A micromachined capacitive temperature sensor is designed and fabricated based on a multilayer cantilever. The top and bottom layers of the cantilever are Al and Si, respectively, which also serve as electrodes of the sensing capacitor. A composite Si3N4/SiO2 layer, a dielectric layer, is sandwiched between the top and bottom electrodes. The cantilever thermal response is due to differences in thermal expansion coefficients for the Al, Si3N4/SiO2 and silicon materials. With the effect of strain on the dielectric property as well as the geometry impact on the capacitance, the temperature variation is sensed and translated to an electrical capacitance change. The mechanical characteristics of the sensor are theoretically analyzed with the extension of Timoshenko's bilayer strip model. The sensor was fabricated with the silicon-on-insulator substrate. Experimental results show that the sensor provides a sensitivity of 7 fF degrees C-1 in the -70 to 100 degrees C range. This makes it suitable to serve as a temperature sensor for low power and wide temperature range applications.
Background Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that plays an important part in the pathogenesis of autoimmune diseases. A high level of MIF has been detected in plaques of psoriasis and the sera of patients with psoriasis. Polymorphisms associated with autoimmune and inflammatory diseases exist in the promoter region of MIF and alter its expression. Objective The aim of this study was to evaluate the potential relationship between functional polymorphisms of MIF and psoriasis in a Han population in northeastern China. Methods Two-hundred-and-forty psoriasis patients and a control group of 269 healthy volunteers were included in this study. We genotyped MIF-173G/C using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). MIF-794CATT5–8 microsatellite polymorphism was genotyped by polyacrylamide gel electrophoresis (PAGE). Results No significant difference in the distributions of alleles, genotypes and haplotypes was observed between patients and controls. When patients were divided into subtypes according to sex, family history and age of onset, distribution of the MIF-173C allele between male and female patients was significantly different (P= 0.04). MIF-173C allelic distribution between late onset psoriasis patients and controls was also different (P = 0.02), as well as late onset patients and early onset subjects (P= 0.04). Conclusions These results suggested a preliminary association between the MIF-173C allele and male psoriasis and late onset psoriasis in the studied population. In addition, the distributions of the two polymorphisms in Asian populations were quite different from the other continental populations.
In this paper we describe an experiment on laser cooling of Rb-87 atoms directly from a vapor background in diffuse light. Diffuse light is produced in a ceramic integrating sphere by multiple scattering of two laser beams injected through multimode fibers. A probe beam, whose propagation direction is either horizontal or vertical, is used to detect cold atoms. We measured the absorption spectra of the cold atoms by scanning the frequency of the probe beam, and observed both the absorption signal and the time of flight signal after we switched off the cooling light, from which we estimated the temperature and the number of cold atoms. This method is clearly attractive for building a compact cold atom clock.
A design and simulation of a fully CMOS compatible micromachined multilayer cantilevers-based environmental thermometer are presented. The operation principle of the structure is depending on the mismatch effect of thermal expansion coefficient and the piezoresistive effect of polysilicon in CMOS process. Upon temperature variation, the deformation of the multilayer cantilever resulted from the large thermal expansion coefficient mismatch of different materials can be sensed and translated to an electrical voltage output by using a symmetric piezoresistive Wheatstone bridge. The mechanical characteristics of the device are analyzed with the extension of bi-layer Timoshenko model and the output of the read-out circuit is also simulated. The calculation and simulation show that the device with bi-direction deformation may have wide temperature range from -100 to 100°C and sensitivity about 0.15mV/°C, which fit the demand of radiosonde for environmental temperature measurement. This sensor may also have other favorable features, such as micro size, low-cost due to its working principle and compatibility with commercial CMOS process.
A novel silicon capacitive temperature sensor implemented with micromachined multilayer cantilevers is presented. The multi-layered sensor structure has been fabricated with SOI wafers by a 4-mask process. Using this structure, the low-power dissipation and wide temperature range can be achieved. For the present sensor, the temperature range is from -70 degrees C to 100 degrees C with the sensitivity of 7fF/degrees C. This makes it suitable to serve as a temperature sensor for low-power and wide temperature range applications.
In this paper, the theory of atomic cooling in an integrating sphere is studied. During designing an integrating sphere system, the effects of the parameters of the sphere on the cooling, including the reflectivity of the material, the shape of the sphere and holes in the sphere have been considered carefully. The experiment of 87Rb atomic cooling in an integrating sphere was performed. The experimental results show that the atoms in the integrating sphere are cooled down evidently. And the relation between the detuning of the cooling laser and the absorption signal of cold atoms was measured.
To screen effective principles from traditional Chinese medicine, a method named hepatocyte extraction combined with HPLC (HE-HPLC) was establish in this study. The active principles in the fruits of Gardenia jasminoides Ellis extract were combined with the hepatocytes under imitated physiological environments. Then the unattached substances were washed off by PBS with pH 7.4. After that the conjugated compounds were eluted by PBS with pH 4.0. These compounds released from target sites were collected and handled through SPE to be condensed, and analyzed by HPLC. The results indicated that two characteristic active compounds in the fruits of G. jasminoides extract binded to the hepatocytes. One of them is geniposide. The other is continued to be identified. It is showed that active principles which could bind to hepotocyte (through receptors, Channels, enzymes, etc.) could be detected, at least partly, by HE-HPLC analysis. There was a significant correlation between the retention properties of the active compounds which was obtained by HE-HPLC and their pharmacological effects on hepotocytes.
Four new polyketide derivatives, Trichodermatides A-D (1-4) were isolated from the marine-derived fungus Trichoderma reesei. Trichodermatide A (1) is an unprecedented example of a polyketide with a ketal-containing pentacyclic skeleton. The chemical structures and absolute configurations of compounds 1-4 were elucidated by extensive spectroscopic methods, especially 2D NMR and CD spectral analysis, and supported by their proposed biosynthesis pathway. The cytotoxicity of 1-4 was evaluated against A375-S2 human melanoma cell line.
We describe a method to generate an ultra-slow atomic beam by velocity selective resonance (VSR). A VSR experiment on a metastable helium beam in a magnetic field is presented and the results show that the transverse velocity of the deflected beam can be cooled and precisely controlled to less than the recoil velocity, depending on the magnitude of the magnetic field. We extend this idea to a cold atomic cloud to produce an ultra slow 87Rb beam that can be used as a source of an atomic fountain clock or a space clock.
One new cinnamic imide derivative, named tribulusimide C (1), was isolated from the fruits of Tribulus terrestris, together with three known compounds, N-p-coumaroyltyramine (2), terrestriamide (3), N-trans-caffeoyltyramine (4). The structure of 1 was elucidated based on chemical analysis and spectral methods (IR, 1D and 2D NMR, HR-FAB-MS, EI-MS).
Two new compounds, 6 '-O-caffeoyl-p-hydroxyacetophenone-4-O-beta-D-glucopyranoside (1) and 6-amino-9-[1-(3,4-dihydroxyphenyl)ethyl]-9H-purine (2) were isolated from the aerial parts of Artemisia capillaris Thunb. The structures were established on the basis of spectral data.
This paper presents an experimental demonstration of light-induced evaporative cooling in a magneto-optical trap. An additional laser is used to interact with atoms at the edge of the atomic cloud in the trap. These atoms get an additional force and evaporated away from the trap by both the magnetic field and laser fields. The remaining atoms have lower kinetic energy and thus are cooled. It reports the measurements on the temperature and atomic number after the evaporative cooling with different parameters including the distance between the laser and the centre of the atomic cloud, the detuning, the intensity. The results show that the light-induced evaporative cooling is a way to generate an ultra-cold atom source.
A novel capacitive temperature sensor based on multilayer cantilevers is presented. The top and bottom layers are metal and heavily boron doped Si, respectively. A combined SiO 2 /Si 3 N 4 layer is utilized as the elastic dielectric layers of the sandwich multilayer cantilever. The operation principle of the structure is based on the effect of thermal expansion coefficient mismatch and the available physical effect of strain on the dielectric property. The deformation of the cantilever due to temperature is sensed and translated to an electrical capacitance change. After the structures of this sensor were designed, the mechanical characteristics of the sensor are theoretically analyzed with the extension of two-layer Timoshenko model. Calculation shows that, compared with traditional temperature sensors, the proposed structure may have a wider temperature range from -90°C to 90°C. This makes it suitable to act as air temperature sensor in radiosonde.
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Two new acetylenic glucosides, 4',6'-acetonide-8Z-decaene-4,6-diyne-1-O-beta-D-glucopyranoside named carthamoside A(1) (1) and 4,6-decadiyne-1-O-beta-D-glucopyranoside named carthamoside A(2) (2), along with one known acetylenic glucoside, 8Z-decaene-4,6-diyne-1-O-beta-D-glucopyranoside (3), have been isolated from the air-dried flower of Carthamus tinctorius, these structures have been identified on the basis of spectroscopic methods.