Nitrogen-plasma doping of carbon film for a high-quality layered Si/C composite anode.

The effect of the chemical component and microstructure, not to mention their facile modification, of the coating/wrapping carbon layer on the electrochemical performance of the Si/C composite anode in lithium ion batteries (LIBs) hasn't been actively explored although Si/C has been recognized as one of the most promising route for the high energy density LIBs. Herein we propose a novel nitrogen-plasma doping route to modify the top carbon film in an elaborately constructed layered Si/C composite anode. The electrochemical performance, e.g., the initial coulombic efficiency (CE), cycle stability and specific capacity of the composite anode is drastically improved by this plasma processing due to the increased kinetics of lithium ions. By means of the appropriate adjustment of the N doping ratio and N chemical configuration in the carbon layer through a N2/H2 plasma processing, the lithium diffusion rate in the composite anode was memorably increased as the pseudocapacitance effects promoted. The optimized Si/C composite exhibits a high capacity of 1120.7 mA h g-1 and an initial CE of 80.8% at the current of 2 A g-1 after a long cycle of 1500, increasing by ~40% of specific capacity and ~29% of the initial CE.

All in one plasma process: From the preparation of S-C composite cathode to alleviation of polysulfide shuttle in Li-S batteries.

Tremendous efforts have been made to improve the electrochemical performance of the lithium-sulfur batteries. However, challenges remain in achieving fast electronic and ionic transport while accommodate the significant cathode volumetric change. On the other hand, the severe capacity decay mainly attributed to polysulfide shuttle also hampers the practical applications. Here, we report a simple, low-cost, and eco-friendly method for the one-step preparation of a binder-free S-C composite cathode by plasma dissociation of CS2 containing gases at room-temperature. The key issue of polysulfide shuttle effect in Li-S batteries is also effectively resolved just by the introduction of N2 into the precursor gases. The electrode exhibits a high reversible capacity of ~600 mAh/g of the total hybrid of S + C at 100 mA/g after 100 cycles with an excellent initial coulombic efficiency of nearly 100%. The cells also demonstrate along cycle life and an extremely high capacity of ~306 mAh/g even after 300 cycles at 1 A/g with a high coulombic efficiency of about 100%. The proposed method will open the way for the plasma applications in facile preparation of Li-S batteries and the improvement of its electrochemical performance.

Wearable, Flexible, Disposable Plasma-Reduced Graphene Oxide Stress Sensors for Monitoring Activities in Austere Environments.

In austere environments, for example, in outer space, on surfaces of extra-terrestrial bodies (Moon, Mars, etc.), or under water, technologies that can enable continuous, reliable, and authentic monitoring of movement of human operators and devices can be critical. We report here the production and human body test of wearable, flexible graphene oxide stress sensors suitable for real-time monitoring of body parameters, state and position of humans, and automatic equipment. These sensors have excellent sensitivity and signal strength across a wide strain range, alleviating the need for additional instrumentation for signal processing and amplification. Their low cost makes them virtually disposable, which may benefit such applications as smart clothing. The sensors were fabricated by a concomitant reduction and N-doping of graphene oxide on polydimethylsiloxane in N2-H2 plasma. The direct bias and other plasma parameters have a significant effect on the reduction and properties of graphene oxide sensors, as shown by optical emission, Raman and X-ray photoelectron spectroscopies, and X-ray diffraction. Optical emission showed different excitation and ionization processes involving atomic and molecular species in the N2-H2 discharge. The photoelectron spectroscopy has confirmed the graphene reduction and introduction of nitrogen doping into the reduced graphene oxide. The bias efficiently controls plasma-induced electric fields, and plasma-related effects determine the N-doping levels. The reduced graphene oxides demonstrate excellent tensile properties, which make them suitable for efficient but cheap stress sensors. This eco-friendly, fast, room-temperature method shows a great potential for fabrication of efficient, flexible sensors.

Hydrogen-plasma-induced Rapid, Low-Temperature Crystallization of µm-thick a-Si:H Films.

Being a low-cost, mass-production-compatible route to attain crystalline silicon, post-deposition crystallization of amorphous silicon has received intensive research interest. Here we report a low-temperature (300 °C), rapid (crystallization rate of ~17 nm/min) means of a-Si:H crystallization based on high-density hydrogen plasma. A model integrating the three processes of hydrogen insertion, etching, and diffusion, which jointly determined the hydrogenation depth of the excess hydrogen into the treated micrometer thick a-Si:H, is proposed to elucidate the hydrogenation depth evolution and the crystallization mechanism. The effective temperature deduced from the hydrogen diffusion coefficient is far beyond the substrate temperature of 300 °C, which implies additional driving forces for crystallization, i.e., the chemical annealing/plasma heating and the high plasma sheath electric field. The features of LFICP (low-frequency inductively coupled plasma) and LFICP-grown a-Si:H are also briefly discussed to reveal the underlying mechanism of rapid crystallization at low temperatures.

Reaction kinetics for the solid state synthesis of the AlH3/MgCl2 nano-composite by mechanical milling.

The process of mechanical milling has been proved to be a cost-effective way to synthesize the AlH3/MgCl2 nano-composite by using MgH2 and AlCl3 as reagents. However, so far there is no comprehensive knowledge of the kinetics of this process. In an effort to predict the reaction progress and optimize the milling parameters, the kinetics of the synthesis of the AlH3/MgCl2 nano-composite by mechanical milling of MgH2 and AlCl3 is experimentally investigated in the present work. The reaction progress or the transformation fraction upon milling for different times is evaluated using the isothermal hydrogen desorption test of the as-milled samples at 220 °C, which is much lower than the threshold temperature for the de-hydriding of the reagent MgH2 but enough for the de-hydriding of the as-synthesized nano-sized AlH3. The effects of milling parameters on the reaction kinetics as well as the underlying mechanism are discussed by referring to the mechanical energy input intensity, the vial temperature and the Gibbs free energy change for the reaction. Furthermore, it is found that the Johnson-Mehl-Avrami (JMA) model can well describe the kinetics theoretically. By fitting the experimental data with the JMA expression, the theoretical kinetics expressions, the equation parameters, and the activation energy are obtained.

Correlation of increased MALAT1 expression with pathological features and prognosis in cancer patients: a meta-analysis.

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been identified as a potential cancer biomarker, yet the mechanism by which it influences the development of cancer remains unknown. In this study, we aimed to correlate MALAT1 expression with pathological features and prognosis in cancer patients. Several databases were searched using combinations of keywords relating to MALAT1 and cancer. After selection of relevant cohort studies according to strict criteria, a meta-analysis was conducted. Twelve studies were analyzed, involving 958 cancer patients. Elevated MALAT1 expression was associated with poor prognosis and larger tumors [prognosis: hazard ratio = 3.11, 95% confidence interval (CI) = 1.98-4.23, P = 0.000; tumor size: odds ratio (OR) = 0.40, 95%CI = 0.21-0.74, P = 0.003]. However, no connection with histological grade, T-stage, lymph node (LN) metastasis, or distant metastasis was established (all P > 0.05). A correlation between increased expression and poor prognosis was observed in the large and small sample-size subgroups (all P< 0.05), as was a relationship with large tumor size (OR = 0.30, 95%CI = 0.13-0.71, P = 0.006). Expression was correlated with T-stage and distant metastasis in the small sample-size subgroup (all P < 0.05), but no association was detected regarding histological grade, LN metastasis in either subgroup (all P > 0.05). Our findings demonstrate that elevated MALAT1 expression correlates with large tumor size, advanced tumor stage, and poor prognosis, and might therefore be utilized to evaluate clinical pathological features and prognostic out come for cancer patients.

Compound heterozygosity for a rare small deletion and a common point mutation in the beta-globin gene: report of two Chinese families.

INTRODUCTION: Most cases of ß-thalassemia are caused by point mutations in the ß-globin gene. Only a minority of ß-thalassemia mutations are small deletions in the exons of the ß-globin gene. METHODS: Here, we report two cases of ß-thalassemia that were caused by compound heterozygosity for a rare small deletion and a common point mutation. RESULTS: Patient A carried a rare 14-bp deletion (CD89-93) mutation plus the common mutation -28(A>G). Patient B carried a rare 13-bp deletion (CD54-58) plus the common mutation IVS-2-654(C>T). CONCLUSION: Patient B is the second report of the CD54-58(-13 bp) deletion. However, our report differs from the previous report in two ways: we performed a family study based on multiple samples; and the carriers and patient showed an elevated level of HbF, which was not observed in the previous case.

Administration of donor-derived mesenchymal stem cells can prolong the survival of rat cardiac allograft.

BACKGROUND: Mesenchymal stem cells (MSCs) are multipotent adult elements that have recently been shown to have profound immunomodulatory effects both in vitro and in vivo. Herein we have examined the impact of intravenous infusion of donor MSCs on the survival of transplanted hearts in a rat allograft model. METHODS: Recipient Fisher344 rats were transplanted with hearts from inbred Wistar rats. Wistar rat MSCs were infused via the tail vein at designated intervals. In vitro mixed lymphocyte reaction (MLR) and cell-mediated lympholysis (CML) assays were performed to assess whether MSCs downregulated T-cell responses in vivo. Real-time polymerase chain reaction (PCR) was used to analyze the Th1/Th2 balance in MSC-treated and control groups. RESULTS: The MSCs cultured in vitro exhibited multipotential for differentiation. Survival of the allografts was markedly prolonged by administration of MSCs compared with the controls, namely mean survivals of 12.4 vs 6.4 days, respectively. Real-time PCR showed a shift in the Th1/Th2 balance toward Th2. By MLR and CML assays, untreated control rats showed greater alloreactivity than did MSC-treated rats. CONCLUSION: Our results indicated that MSCs suppressed allogeneic T-cell responses both in vitro and in vivo. Intravenous administration of MSCs prolonged the survival of transplanted hearts, possibly by induction of allograft tolerance through changing the Th1/Th2 balance.

Agrobacterium-mediated large-scale transformation of wheat (Triticum aestivum L.) using glyphosate selection.

An Agrobacterium-mediated transformation system with glyphosate selection has been developed for the large-scale production of transgenic plants. The system uses 4-day precultured immature embryos as explants. A total of 30 vectors containing the 5-enol-pyruvylshikimate-3-phosphate synthase gene from Agrobacterium strain CP4 (aroA:CP4), which confers resistance to glyphosate, were introduced into wheat using this system. The aroA:CP4 gene served two roles in this study-selectable marker and gene of interest. More than 3,000 transgenic events were produced with an average transformation efficiency of 4.4%. The entire process from isolation of immature embryos to production of transgenic plantlets was 50-80 days. Transgenic events were evaluated over several generations based on genetic, agronomic and molecular criteria. Forty-six percent of the transgenic events fit a 3:1 segregation ratio. Molecular analysis confirmed that four of six lead transgenic events selected from Agrobacterium transformation contained a single insert and a single copy of the transgene. Stable expression of theAROA:CP4 gene was confirmed by ELISA through nine generations. A comparison of Agrobacterium-mediated transformation to a particle bombardment system demonstrated that the Agrobacterium system is reproducible, has a higher transformation efficiency with glyphosate selection and produces higher quality transgenic events in wheat. One of the lead events from this study, no. 33391, has been identified as a Roundup Ready wheat commercial candidate.

Preanalytical factors and standardized specimen collection: influence of psychological stress.

In order to devise and evaluate standardized specimen collection procedures, we studied the influence of psychological stress on the results of commonly analysed blood components: creatine kinase, lactate dehydrogenase, total protein and albumin in serum and blood picture. In addition, serum cortisol was assayed. Two kinds of stress were used: the Stroop test, a colour conflict task, and the thrill caused by the first jump of new parachutists. More changes were observed after the parachutist test than after the Stroop test. There was a difference in the responses of males and females. Females were more sensitive, especially to the parachutist test. Most of the changes observed were interpreted as being caused by haemoconcentration, possibly related to muscular tension. Cortisol, commonly used to indicate the level of stress, did not react much and is therefore not a good index of psychological stress.

An investigation of three commercial methods for rapid identification of non-enteric gram-negative rods. Application on Pseudomonas paucimobilis and some other Pseudomonas species.

Three commercial systems for the identification of non-enteric gram-negative rods were compared with conventional bacteriological methods as reference. The three systems were the API 20 NE, BIO-TEST ID-Trident, and ROSCO Diagnostic Tablets. The systems were tested on a set of 47 strains from the genus Pseudomonas, with the emphasis upon the yellow-pigmented species. The overall identification accuracy was 97% with the API, 19% with the BIOTEST and 68% with the ROSCO system. The API system was thus reliable, and it presented no major practical problems. The BIOTEST system was very handy. The main reason for the low accuracy was an error in the code book. The ONPG reaction was depicted as negative in the species P. paucimobilis. A positive ONPG test is a keymark in this species and 76% of the 20 strains of P. paucimobilis included in this investigation were also found positive with the BIOTEST system. The ROSCO tablets are convenient if the result of single reactions is desired. The time consumption per strain was 5.4, 4.4, and 6.2 min for the API, BIOTEST, and ROSCO systems respectively.