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1.
Most microfluidic chips utilize off-chip hardware (syringe pumps, computer-controlled solenoid valves, pressure regulators, etc.) to control fluid flow on-chip. This expensive, bulky, and power-consuming hardware severely limits the utility of microfluidic instruments in resource-limited or point-of-care contexts, where the cost, size, and power consumption of the instrument must be limited. In this work, we present a technique for on-chip fluid control that requires no off-chip hardware. We accomplish this by using inert compounds to change the density of one fluid in the chip. If one fluid is made 2% more dense than a second fluid, when the fluids flow together under laminar flow the interface between the fluids quickly reorients to be orthogonal to Earth’s gravitational force. If the channel containing the fluids then splits into two channels, the amount of each fluid flowing into each channel is precisely determined by the angle of the channels relative to gravity. Thus, any fluid can be routed in any direction and mixed in any desired ratio on-chip simply by holding the chip at a certain angle. This approach allows for sophisticated control of on-chip fluids with no off-chip control hardware, significantly reducing the cost of microfluidic instruments in point-of-care or resource-limited settings.  相似文献   
2.
Lack of temperature sensation of myoelectric prosthetic hand limits the daily activities of amputees.To this end,a non-invasive temperature sensation method is proposed to train amputees to sense temperature with psychophysical sensory substitution.In this study,22 healthy participants took part besides 5 amputee participants.The duration time of the study was 31 days with five test steps according to the Leitner technique.An adjustable temperature mug and a Peltier were used to change the temperature of the water/phantom digits to induce temperature to participants.Also,to isolate the surround-ings and show colors,a Virtual Reality(VR)glass was employed.The statistical results conducted are based on the response of participants with questionnaire method.Using Chi-square tests,it is concluded that participants answer the experiment significantly correctly using the Leitner technique(P value<0.05).Also,by applying the"Repeated Measures ANOVA",it is noticed that the time of numbness felt by participants had significant(P value<0.001)difference.Participants could remember lowest and highest temperatures significantly better than other temperatures(P value<0.001);furthermore,the well-trained amputee participant practically using the prosthesis with 72.58%could identify object's temperature with only once time experimenting the color temperature.  相似文献   
3.
Li metal is a promising anode material for all‐solid‐state batteries, owing to its high specific capacity and low electrochemical potential. However, direct contact of Li metal with most solid‐state electrolytes induces severe side reactions that can lead to dendrite formation and short circuits. Moreover, Li metal is unstable when exposed to air, leading to stringent processing requirements. Herein, it is reported that the Li3PS4/Li interface in all‐solid‐state batteries can be stabilized by an air‐stable LixSiSy protection layer that is formed in situ on the surface of Li metal through a solution‐based method. Highly stable Li cycling for over 2000 h in symmetrical cells and a lifetime of over 100 cycles can be achieved for an all‐solid‐state LiCoO2/Li3PS4/Li cell. Synchrotron‐based high energy X‐ray photoelectron spectroscopy in‐depth analysis demonstrates the distribution of different components within the protection layer. The in situ formation of an electronically insulating LixSiSy protection layer with highly ionic conductivity provides an effective way to prevent Li dendrite formation in high‐energy all‐solid‐state Li metal batteries.  相似文献   
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Summary Despite intensive efforts, a reproducible and reliable method for transformation of sugarbeet plants is still lacking. Having examined several explants, we found that cells around the main vein of leaves of plantlets reared from tissue-cultured apical meristems are sufficiently competent for transformation and subsequent regeneration. A transformation protocol was designed by evaluating alterations in several parameters such as plant genotype, Agrobacterium strain, antibiotics, darkness and duration of co-culture period. An average transformation rate of 6.2% transformed shoots per explant was achieved as judged by Southern blotting. Consistent inactivation of reporter genes was correlated to multiple copies of transgenes present in some transformants. The necessary steps for rooting and planting of transformed shoots were also established.  相似文献   
6.
Applied Microbiology and Biotechnology - Interferon beta (IFNβ) is transiently expressed in response to viral infections and widely used to treat relapsing-remitting multiple sclerosis (MS)....  相似文献   
7.
Beet necrotic yellow vein virus (BNYVV) is the most devastating pathogen of sugar beet worldwide. This virus has been reported in the majority of sugar beet growing regions of Iran as well. For the present study, we collected samples from different sugar beet varieties with suspected symptoms of BNYVV from the main important sugar beet growing regions in eight provinces of Iran. Infection of collected samples to BNYVV was tested by ELISA and RT-PCR. Upon testing of 167 collected samples of BNYVV suspected through ELISA and RT-PCR, 115 (68.9%) were infected. Different incidences of BNYVV through surveyed provinces may represent the presence of diverse infective viral sources or resistance genes in tested sugar beet varieties which need further attempts to develop control strategies. Results also showed that BNYVV has been recently distributed throughout some surveyed regions. Otherwise, trace infection or resistance to BNYVV infection in some varieties of distinct regions may represent proper sources of resistance to BNYVV.  相似文献   
8.

Key message

Depending on salt concentrations, different mechanisms are involved in the tolerance of pistachio and an acclimation to salinity conditions occurs in the leaves that develop in the presence of salt.

Abstract

Pistachio (Pistacia vera L.) is a salt tolerant species that is considered an alternative crop for cultivation in salinzied orchard soils. In this work, 12-week-old pistachio seedlings cultivated in soil under greenhouse conditions were treated with five levels of salinity including control (0.63 dSm?1), low (2 and 4 dSm?1) and high (8 and 10 dSm?1) salt concentrations for further 12 weeks. Plant growth parameters were not affected by mild salinity; a significant reduction was only observed from 8 dSm?1. Considerable differences were observed between the young and mature leaves regarding osmotic and ionic stress effects of salt. Main compatible solutes were proline in mature leaves, proline and soluble sugars in young leaves, and soluble sugars and amino acids, other than proline, in roots. Concentration and content of Na in the leaves were not significantly increased at low levels of salinity and the K:Na and Ca:Na ratio of leaves were affected only by higher salt concentrations. Using the sequential extraction procedure for cell wall isolation, we observed that both absolute and relative amounts of Na in the cell wall fraction increased under low salinity, while decreased under higher levels of salt supply. Stable water relations, photochemistry and CO2 assimilation rates particularly of young leaves, as well as ion homeostasis were mechanisms for maintenance of plants growth under mild salinity. Under severe saline conditions, the impaired ability of mature leaves for synthesis of assimilates, preferent allocation of carbohydrates to roots for maintenance of osmotic homeostasis and finally, reduction of protein synthesis caused growth inhibition in pistachio.  相似文献   
9.
It is generally accepted that children with attention-deficit/hyperactivity disorder (ADHD) have poor motor control, especially in bimanual coordination tasks. Such children characteristically have impaired fine motor ability, problems with force control, and poor motor coordination. They are at particular risk of loss of motor control and reduced bimanual coordination. We tested whether, compared to a control condition, neurofeedback training (NFT) could improve bimanual coordination among children with ADHD. 20 Children with ADHD (mean age 7.9 years; SD 2.11) were randomly assigned either to NFT or to a control condition. All participants completed a bimanual coordination test at the following time points: baseline, assessment 1, assessment 2, assessment 3, and again 12 session later at posttest. NFT consisted of Sensory Motor Rhythm (SMR) training to achieve increased SMR in C3 and C4, while participants in the control condition were under mock NFT conditions. Bimanual coordination accuracy and consistency improved from baseline to completion of the intervention (significant Time effect), but in the NFT condition (significant time?×?group interaction). Compared to the control condition, the NFT group had fewer errors in both patterns of bimanual coordination (significant Group effect). Among children with ADHD, SMR neurofeedback training (NFT) led to significant improvements in a bimanual coordination task. The SMR NFT thus appears to have the potential to improve and enhance the motor control of ADHD patients.  相似文献   
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