Influence of a horizontal approach on the mechanical output during drop jumps

This study investigated the influence of a horizontal approach to mechanical output during drop jumps. Participants performed drop jumps from heights of 15, 30, 45, and 60 cm with zero, one, two, and three approach steps. The peak summed power during the push-off phase changed quadratically across heights (6.2 +/- 0.3, 6.7 +/- 0.4, 6.4 +/- 0.4, and 6.0 +/- 0.4 kW, respectively) driven by the ankle joint response. Summed peak power was 10% greater with an approach attributed to the knee joint response. Downward phase dorsiflexion (31%), knee flexion (35%), and peak vertical force (32%) increased with drop heights. Vertical approach force (22%) increased, while knee flexion (11%) and downward duration (17%) decreased. An approach may improve drop jump training for explosive tasks.     

Understanding the Impact of Fluorine Substitution on the Photovoltaic Performance of Block Copolymers

Fluorine substitution was applied to the donor and acceptor segments of block copolymers to understand the impact of molecular structure on photovoltaic block copolymers and explore efficient materials for single-component organic solar cells(SCOSCs).Along this line,three fluorinated block copolymers,namely PBDB-T-b-PTYF6,PM6-b-PTY6,and PM6-bPTYF6,derived from PBDB-T-b-PTY6 were designed and synthesized.The UV-Vis absorption,energy level,and thin-film morphology of these block copolymers were sy...     

Recent Development of Quantum Dot Deposition in Quantum Dot-Sensitized Solar Cells

As new-generation solar cells,quantum dot-sensitized solar cells(QDSCs) have the outstanding advantages of low cost and high theoretical efficiency;thus,such cells receive extensive research attention.Their power conversion efficiency(PCE)has increased from 5% to over 15% in the past decade.However,compared with the theoretical efficiency(44%),the PCE of QDSCs still needs further improvement.The low loading amount of quantum dots(QDs) is a key factor limiting the improvement of cell efficiency.T...     

Heterogeneous Catalysis for CO2 Conversion into Chemicals and Fuels

Catalytic conversion of CO₂ into chemicals and fuels is a viable method to reduce carbon emissions and achieve carbon neutrality.Through thermal catalysis,electrocatalysis,and photo(electro)catalysis,CO₂ can be converted into a wide range of valuable products,including CO,formic acid,methanol,methane,ethanol,acetic acid,propanol,light olefins,aromatics,and gasoline,as well as fine chemicals.In this mini-review,we summarize the recent progress in heterogeneous catalysis for ...     

车用甲醇汽油分析

能源枯竭和环境污染是世界面临的严重问题,随着世界汽车保佑量的增长,在世界范围内石油系燃料的供需矛盾日益突出,汽车发动机消耗石油总量巨大,废气的排放也成为大气污染的主要来源之一。从资源、经济、实用等方面来考虑,开发新的清洁代用燃料成为重要的研究课题。甲醇燃料来源丰富,能够节约汽车运营成本,节约大量的石油资源。本文以M5、M15甲醇汽油为例分析了使用甲醇汽油的经济性和推广性。     

Thermomodulated cell culture∕harvest in polydimethylsiloxane microchannels with poly(N-isopropylacrylamide)-grafted surface

Cell culture and harvest are the most upstream operation for a completely integrated cell assay chip. In our previous work, thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm) was successfully grafted onto polydimethylsiloxane (PDMS) surface via benzophenone-initiated photopolymerization. In the present work, the PNIPAAm-grafted-PDMS (PNIPAAm-g-PDMS) surface was explored for thermomodulated cell culture and noninvasive harvest in microfluidic channels. Using COS 7 fibroblast from African green monkey kidney as the model cells, the thermomodulated adhering and detaching behaviors of the cells on the PNIPAAm-g-PDMS surfaces were optimized with respect to PNIPAAm-grafting yields and gelatin modification. The viability of the cells cultured on and harvested from the PNIPAAm-g-PDMS surface with the thermomodulated noninvasive protocol was estimated against the traditional cell culture∕harvest method involving trypsin digestion. The configuration of the microchannel on the PNIPAAm-g-PDMS chip was evaluated for static cell culture. Using a pipette-shaped PNIPAAm-g-PDMS microchannel, long-term cell culture could be achieved at 37 °C with periodic change of the culture medium every 12 h. After moving the microchip from the incubator set at 37 °C to the room temperature, the proliferated cells could be spontaneously detached from the PNIPAAm-g-PDMS surface of the upstream chamber and transferred by a gentle fluid flow to the downstream chamber, wherein the transferred cells could be subcultured. The thermomodulated cell culture, harvest, and passage operations on the PNIPAAm-g-PDMS microfluidic channels were demonstrated.     

A numerical approach to hopf bifurcation points

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Multi-region calcium imaging in freely behaving mice with ultra-compact head-mounted fluorescence microscopesOA

To investigate the circuit-level neural mechanisms of behavior, simultaneous imaging of neuronal activity in multiple cortical and subcortical regions is highly desired. Miniature head-mounted microscopes offer the capability of calcium imaging in freely behaving animals. However, implanting multiple microscopes on a mouse brain remains challenging due to space constraints and the cumbersome weight of the equipment.Here, we present TINIscope, a Tightly Integrated Neuronal Imaging microscope opti...     

Chronic ankle instability is associated with proprioception deficits: A systematic review and meta-analysis

Background:Acute ankle injury causes damage to joint mechanoreceptors and deafferentation and contributes to proprioception deficits in patients with chronic ankle instability(CAI).We aimed to explore whether deficits of proprioception,including kinesthesia and joint position sense(JPS),exist in patients with CAI when compared with the uninjured contralateral side and healthy people.We hypothesized that proprioception deficits did exist in patients with CAI and that the deficits varied by test methodologies.Methods:The study was a systematic review and meta-analysis.We identified studies that compared kinesthesia or JPS in patients with CAI with the uninjured contralateral side or with healthy controls.Meta-analyses were conducted for the studies with similar test procedures,and narrative syntheses were undertaken for the rest.Results:A total of 7731 studies were identified,of which 30 were included for review.A total of 21 studies were eligible for meta-analysis.Compared with the contralateral side,patients with CAI had ankle kinesthesia deficits in inversion and plantarflexion,with a standardized mean difference(SMD)of 0.41 and 0.92,respectively,and active and passive JPS deficits in inversion(SMD=0.92 and 0.72,respectively).Compared with healthy people,patients with CAI had ankle kinesthesia deficits in inversion and eversion(SMD=0.64 and 0.76,respectively),and active JPS deficits in inversion and eversion(SMD=1.00 and 4.82,respectively).Proprioception deficits in the knee and shoulder of patients with CAI were not statistically significant.Conclusion:Proprioception,including both kinesthesia and JPS,of the injured ankle of patients with CAI was impaired,compared with the uninjured contralateral limbs and healthy people.Proprioception varied depending on different movement directions and test methodologies.The use of more detailed measurements of proprioception and interventions for restoring the deficits are recommended in the clinical management of CAI.