Unique walnut-shaped porous MnO<inf>2</inf>/C nanospheres with enhanced reaction kinetics for lithium storage with high capacity and superior rate capability

Unique walnut-shaped porous MnO2/carbon nanospheres via in situ carbonization of amorphous MnO2 nanospheres demonstrate enhanced reaction kinetics for lithium storage.This work is realized in the frame of a program for Changjiang Scholars and Innovative Research Team (IRT_15R52) of Chinese Ministry of Education. B. L. Su acknowledges the Chinese Central Government for an “Expert of the State” position in the Program of the “Thousand Talents” and a Life Membership at the Clare Hall, Cambridge and the financial support of the Department of Chemistry, University of Cambridge. Y. Li acknowledges Hubei Provincial Department of Education for the “Chutian Scholar” program. T. Hasan acknowledges funding from the Royal Academy of Engineering (Graphlex) and an Impact Acceleration Award (GRASS). This work is also financially supported by the National Science Foundation for Young Scholars of China (No. 21301133 and 51302204), International Science & Technology Cooperation Program of China (2015DFE52870) and and Self-determined and Innovative Research Funds of the SKLWUT (2015‐ZD‐7). The authors also would like to thank Dr. Bin-Jie Wang from Shanghai Nanoport (FEI, Shanghai) for TEM analysis, and thank Hang Ping from Wuhan University of Technology for the TGA/DSC tests.This is the author accepted manuscript. The final version is available from the Royal Society of Chemistry via http://dx.doi.org/10.1039/C6TA00594

Stochastic Gravity: Theory and Applications

Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein-Langevin equation, which has in addition sources due to the noise kernel.In the first part, we describe the fundamentals of this new theory via two approaches: the axiomatic and the functional. In the second part, we describe three applications of stochastic gravity theory. First, we consider metric perturbations in a Minkowski spacetime: we compute the two-point correlation functions for the linearized Einstein tensor and for the metric perturbations. Second, we discuss structure formation from the stochastic gravity viewpoint. Third, we discuss the backreaction of Hawking radiation in the gravitational background of a quasi-static black hole.Comment: 75 pages, no figures, submitted to Living Reviews in Relativit

Manganese dioxide nanosheet functionalized sulfur@PEDOT core-shell nanospheres for advanced lithium-sulfur batteries

MnO2 nanosheet functionalized S@PEDOT core–shell nanospheres demonstrate highly enhanced electrochemical performance for Li–S batteries, benefitting from effectively trapping polysulfides, minimizing polysulfide dissolution, and improving cathode conductivity and wettability.This is the accepted manuscript. The final version is available at http://pubs.rsc.org/en/content/articlelanding/2016/ta/c6ta03211g#!divAbstract

Stochastic Gravity: Theory and Applications

Whereas semiclassical gravity is based on the semiclassical Einstein equation with sources given by the expectation value of the stress-energy tensor of quantum fields, stochastic semiclassical gravity is based on the Einstein-Langevin equation, which has in addition sources due to the noise kernel. In the first part, we describe the fundamentals of this new theory via two approaches: the axiomatic and the functional. In the second part, we describe three applications of stochastic gravity theory. First, we consider metric perturbations in a Minkowski spacetime, compute the two-point correlation functions of these perturbations and prove that Minkowski spacetime is a stable solution of semiclassical gravity. Second, we discuss structure formation from the stochastic gravity viewpoint. Third, we discuss the backreaction of Hawking radiation in the gravitational background of a black hole and describe the metric fluctuations near the event horizon of an evaporating black holeComment: 100 pages, no figures; an update of the 2003 review in Living Reviews in Relativity gr-qc/0307032 ; it includes new sections on the Validity of Semiclassical Gravity, the Stability of Minkowski Spacetime, and the Metric Fluctuations of an Evaporating Black Hol

Suppression of gas species signals in direct current glow discharge time-of-flight mass spectrometry

The possibility of suppressing gas species in direct current glow discharge mass spectrometry (dc-GDMS) with a linear time-of-flight mass analyzer was investigated. With this tic-GD ion source, a 'clean' mass spectrum rich in analyte could be obtained when the dc-GD was operated under a discharge current of 15-30 mA and a gas pressure of 300-500 Pa, in contrast to the strong signals of gas species in convention dc-GDMS, which operates at lower currents and pressures (typically 1-5 mA and 100 Pa). Such an experimental result is believed to be due to increased sputtering at higher pressures and currents, and the different ionization mechanisms of analyte and gas species. For a possible GD design to eliminate the background gas ions, a new discharge configuration was developed by attaching a TM,,, microwave resonator to the GD ion source. The mass spectrum of the cathode sample showed a low gas species background when the microwave-induced plasma (MIP) discharge was 'off' under different dc-GD parameters. The mass spectra of analyte and gas species obtained with 'MIP + dc-GD' and 'MIP only' modes are also compared and discussed. It was found that the analyte signals decrease and the gas species signals increase in the presence of the MIP, and that the analyte signals nearly disappear in the 'MIP only' mode. Preliminary results suggest that, for specific discharge conditions and with a suitable design of the GD source, an efficient suppression of gas species in dc-GDMS detection could be realized

Pre-competition habits and injuries in Taekwondo athletes

BACKGROUND: Over the past decade, there has been heightened interest in injury rates sustained by martial arts athletes, and more specifically, Taekwondo athletes. Despite this interest, there is a paucity of research on pre-competition habits and training of these athletes. The purpose of this pilot study was to assess training characteristics, competition preparation habits, and injury profiles of Taekwondo athletes. METHODS: A retrospective survey of Canadian male and female Taekwondo athletes competing in a national tournament was conducted. Competitors at a Canadian national level tournament were given a comprehensive survey prior to competition. Items on training characteristics, diet, and injuries sustained during training and competition were included. Questionnaires were distributed to 60 athletes. RESULTS: A response rate of 46.7% was achieved. Of those that responded, 54% dieted prior to competition, and 36% dieted and exercised pre-competition. Sixty-four percent of the athletes practised between 4–6 times per week, with 54% practicing 2 hours per session. Lower limb injuries were the most common (46.5%), followed by upper extremity (18%), back (10%), and head (3.6%). The majority of injuries consisted of sprains/strains (45%), followed by contusions, fractures, and concussions. More injuries occurred during training, including 59% of first injuries. CONCLUSION: More research needs to be conducted to further illustrate the need for appropriate regulations on weight cycling and injury prevention

Low penetrance of retinoblastoma for p.V654L mutation of the RB1 gene

<p>Abstract</p> <p>Background</p> <p>Retinoblastoma is caused by compound heterozygosity or homozygosity of retinoblastoma gene (<it>RB1</it>) mutations. In germline retinoblastoma, mutations in the <it>RB1 </it>gene predispose individuals to increased cancer risks during development. These mutations segregate as autosomal dominant traits with high penetrance (90%).</p> <p>Methods</p> <p>We screened 30 family members from one family using high resolution melting assay and DNA direct sequencing for mutations in the <it>RB1 </it>gene. We evaluate the phenotype and penetrance of germline mutations of the <it>RB1 </it>gene in a large Taiwanese family.</p> <p>Results</p> <p>The molecular analysis and clinical details of this family showed phenotypic variability associated with the p.V654L mutation in exon 19 of the <it>RB1 </it>gene in 11 family members. The phenotype varied from asymptomatic to presence of a unilateral tumor. Only four individuals (2 males and 2 females) developed unilateral retinoblastoma, which resulted in calculated low penetrance of 36% (4/11). The four individuals with retinoblastoma were diagnosed before the age of three years. None of their relatives exhibited variable severity or bilateral retinoblastoma.</p> <p>Conclusions</p> <p>The diseased-eye ratio for this family was 0.36, which is lower than current estimates. This suggests that the <it>RB1 </it>p.V654L mutation is a typical mutation associated with low penetrance.</p

Inkjet-Printed rGO/binary Metal Oxide Sensor for Predictive Gas Sensing in a Mixed Environment

Funder: Alphasense LimitedAbstract: Selectivity for specific analytes and high‐temperature operation are key challenges for chemiresistive‐type gas sensors. Complementary hybrid materials, such as reduced graphene oxide (rGO) decorated with metal oxides enables realization of room‐temperature sensors with enhanced sensitivity. However, sensor training to identify target gases and accurate concentration measurement from gas mixtures still remain very challenging. This work proposes hybridization of rGO with CuCoO x binary metal oxide as a sensing material. Highly stable, room‐temperature NO2 sensors with a 50 ppb of detection limit is demonstrated using inkjet printing. A framework is then developed for machine‐intelligent recognition with good visibility to identify specific gases and predict concentration under an interfering atmosphere from a single sensor. Using ten unique parameters extracted from the sensor response, the machine learning‐based classifier provides a decision boundary with 98.1% accuracy, and is able to correctly predict previously unseen NO2 and humidity concentrations in an interfering environment. This approach enables implementation of an intelligent platform for printable, room‐temperature gas sensors in a mixed environment irrespective of ambient humidity

Anchoring ultrafine metallic and oxidized Pt nanoclusters on yolk-shell TiO2 for unprecedentedly high photocatalytic hydrogen production

We demonstrate an alkali modification process to produce highly dispersed ultrafine Pt nanoclusters with metallic Pt$^0$ and oxidized Pt$^{2+}$ species as co-catalyst anchored on nanosheet-constructed yolk-shell TiO$_2$ (NYTiO$_2$-Pt) acting as light harvesting reactor for highly efficient photocatalytic H$_2$ production. Benefiting from the high surface area, highly dispersed ultrafine Pt nanoclusters (~0.6 nm) with Pt$^0$ and Pt$^{2+}$ species and special nanosheet-constructed yolk-shell structure, this novel light harvesting reactor exhibits excellent performance for photocatalytic H$_2$ production. The NYTiO$_2$-Pt-0.5 (0.188 wt% Pt) demonstrates an unprecedentedly high H$_2$ evolution rate of 20.88 mmol h$^{−1}$ g$^{−1}$ with excellent photocatalytic stability, which is 87 times than that of NYTiO$_2$-Pt-3.0 (0.24 mmol h$^{−1}$ g$^{−1}$, 1.88 wt% Pt), and also much higher than those of other TiO$_2$ nanostructures with the same Pt content. Such H$_2$ evolution rate is the highest reported for photocatalytic H$_2$ production with such a low Pt content under simulated solar light. Our strategy here suggests that via alkali modifying the photocatalysts, we can not only enhance the H$_2$ production for solar energy conversion but also significantly decrease the noble metal content for cost saving.B. L. Su acknowledges the Chinese Central Government for an “Expert of the State” position in the Program of the “Thousand Talents” and a Life Membership at the Clare Hall, Cambridge and the financial support of the Department of Chemistry, University of Cambridge. Y. Li acknowledges Hubei Provincial Department of Education for the “Chutian Scholar” program. T. H. acknowledges support from the Royal Academy of Engineering through a Research Fellowship and an EPSRC Impact acceleration grant. This work is supported by the National Key Research and Development Program of China (2016YFA0202602), Program for Changjiang Scholars and Innovative Research Team in University (IRT_15R52), International Science & Technology Cooperation Program of China (2015DFE52870), National Natural Science Foundation of China (51302204 and 51502225) and the Fundamental Research Funds for the Central Universities (WUT: 2016 029)

Microwave-induced plasma boosted microsecond-pulse glow discharge optical emission spectrometry

A microsecond-pulse (mu s-pulse) glow discharge (GD) source boosted by a microwave-induced plasma (MIP) has been developed and studied for optical emission spectrometry (OES), The excitation processes of the tandem GD source were investigated, The analytical characteristics of the GD-OES source in the presence and absence of the MIP were compared, including the operating parameters, signal-to-background ratios (S/B) and relative standard deviation (RSD), The results show that under a relatively low discharge pressure (<180 Pa), the mu s-pulse GD can couple fairly well with the MIP and emit intense analytical lines, When the GD source is operated under a pressure higher than 200 Pa, tao emission peaks appear, independent in time, for a given resonance atomic line, because sample atoms are independently structurally excited, first by the mu s-pulse GD and then by the MIP. The time interval between the tao peaks for Zn I 213.8 nm is longer than that for Cu I 324.7 nm, which is believed to be due to the faster diffusing velocity of copper atoms, When the mu s-pulse GD lamp is operated under a gas pressure higher than 220 Pa, the ion population is so high that Cu II ionic line at 224.7 nm 'becomes' two peaks because of a possible self-absorption. The results show that the supplementary nse of an MIP can eliminate the self-absorption of ionic and atomic lines, When the mu s-pulse GD source is coupled with the MTP, S/Bs are improved by a factor of more than one order of magnitude for several analytical lines. A short-term RSD of 0.2% is achieved for the 'mu s-pulse GD+MIP' configuration compared with that of 1.0% for 'mu s-pulse GD only' mode. The experimental results show that the MIP boosted mu s-pulse GD is a promising technique for solid sample and surface analysis