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Chengdu, China

Sichuan University is one of the national key comprehensive universities, located in Chengdu, the capital city of Sichuan Province, China, with a long history and many predecessors, of which the earliest one was founded in 1740 with the origin in BCE 141. It was transformed to be a modern university in 1920s and the name National Sichuan University was adopted in 1931.Sichuan University is one of the national universities directly under the Ministry of Education . It is also one of the State 211 Project and 985 Project universities enjoying privileged construction in the Ninth Five-Year Plan period. It is ranked No. 8 among the Chinese universities according to the 2010 Academic Ranking of World Universities.The president of the university is Professor Xie Heping, an academician of the Chinese Academy of Engineering. Wikipedia.

The fabrication and drug delivery of novel polypseudorotaxane micelles with small molecule coumarin derivative as hydrophobic segment were reported. 7-Carboxymethoxy coumarin was immobilized on the terminal hydroxyl groups of poly(ethylene glycol) (PEG). The modified PEG chains were threaded in α-cyclodextrins (α-CDs) to form polypseudorotaxanes. The polypseudorotaxanes self-assembled into supramolecular micelles driven by hydrophobic interaction and polypseudorotaxane crystallization. Anti-tumor drug doxorubicin (DOX) was trapped in the micelles. The structure, morphology, drug release profile and cytotoxicity of the micelles were investigated. The in vitro anti-tumor studies including cellular uptake and inhibition efficiency were performed on mice cancer cell lines of TC1 lung cancer cells and B16 melanoma cells. The results revealed that the 7-carboxymethoxy coumarin modified PEG could thread into the cavity of α-CDs to form necklace-like polypseudorotaxanes. The polypseudorotaxanes self-assembled into spherical micelles with the mean size of 30 nanometers, and the size was increased to about 80 nanometers after the drug was loaded. The drug loading content of the micelles was decreased with increasing the chain length of PEG. The sustaining release of DOX could last for 32 hours. The polypseudorotaxane micelles were non-toxic to both TC1 and B16 cells. The IC50 of the DOX loaded polypseudorotaxane micelles with PEG2k was lower than that of micelles with PEG4k or PEG6k both in TC1 and B16 cells.

Shi Z.,University of Sichuan
The Cochrane database of systematic reviews | Year: 2013

Ventilator-associated pneumonia (VAP) is defined as pneumonia developing in persons who have received mechanical ventilation for at least 48 hours. VAP is a potentially serious complication in these patients who are already critically ill. Oral hygiene care (OHC), using either a mouthrinse, gel, toothbrush, or combination, together with aspiration of secretions may reduce the risk of VAP in these patients. To assess the effects of OHC on the incidence of VAP in critically ill patients receiving mechanical ventilation in intensive care units (ICUs) in hospitals. We searched the Cochrane Oral Health Group's Trials Register (to 14 January 2013), CENTRAL (The Cochrane Library 2012, Issue 12), MEDLINE (OVID) (1946 to 14 January 2013), EMBASE (OVID) (1980 to 14 January 2013), LILACS (BIREME) (1982 to 14 January 2013), CINAHL (EBSCO) (1980 to 14 January 2013), Chinese Biomedical Literature Database (1978 to 14 January 2013), China National Knowledge Infrastructure (1994 to 14 January 2013), Wan Fang Database (January 1984 to 14 January 2013), OpenGrey and ClinicalTrials.gov (to 14 January 2013). There were no restrictions regarding language or date of publication. We included randomised controlled trials (RCTs) evaluating the effects of OHC (mouthrinse, swab, toothbrush or combination) in critically ill patients receiving mechanical ventilation. Two review authors independently assessed all search results, extracted data and undertook risk of bias. We contacted study authors for additional information. Trials with similar interventions and outcomes were pooled reporting odds ratios (OR) for dichotomous outcomes and mean differences (MD) for continuous outcomes using random-effects models unless there were fewer than four studies. Thirty-five RCTs (5374 participants) were included. Five trials (14%) were assessed at low risk of bias, 17 studies (49%) were at high risk of bias, and 13 studies (37%) were assessed at unclear risk of bias in at least one domain. There were four main comparisons: chlorhexidine (CHX mouthrinse or gel) versus placebo/usual care, toothbrushing versus no toothbrushing, powered versus manual toothbrushing and comparisons of oral care solutions.There is moderate quality evidence from 17 RCTs (2402 participants, two at high, 11 at unclear and four at low risk of bias) that CHX mouthrinse or gel, as part of OHC, compared to placebo or usual care is associated with a reduction in VAP (OR 0.60, 95% confidence intervals (CI) 0.47 to 0.77, P < 0.001, I(2) = 21%). This is equivalent to a number needed to treat (NNT) of 15 (95% CI 10 to 34) indicating that for every 15 ventilated patients in intensive care receiving OHC including chlorhexidine, one outcome of VAP will be prevented. There is no evidence of a difference between CHX and placebo/usual care in the outcomes of mortality (OR 1.10, 95% CI 0.87 to 1.38, P = 0.44, I(2) = 2%, 15 RCTs, moderate quality evidence), duration of mechanical ventilation (MD 0.09, 95% CI -0.84 to 1.01 days, P = 0.85, I(2) = 24%, six RCTs, moderate quality evidence), or duration of ICU stay (MD -0.21, 95% CI -1.48 to 1.89 days, P = 0.81, I(2) = 9%, six RCTs, moderate quality evidence). There was insufficient evidence to determine whether there is a difference between CHX and placebo/usual care in the outcomes of duration of use of systemic antibiotics, oral health indices, microbiological cultures, caregivers preferences or cost. Only three studies reported any adverse effects, and these were mild with similar frequency in CHX and control groups.From three trials of children aged from 0 to 15 years (342 participants, moderate quality evidence) there is no evidence of a difference between OHC with CHX and placebo for the outcomes of VAP (OR 1.07, 95% CI 0.65 to 1.77, P = 0.79, I(2) = 0%), or mortality (OR 0.73, 95% CI 0.41 to 1.30, P = 0.28, I(2) = 0%), and insufficient evidence to determine the effect on the outcomes of duration of ventilation, duration of ICU stay, use of systemic antibiotics, plaque index, microbiological cultures or adverse effects, in children.Based on four RCTs (828 participants, low quality evidence) there is no evidence of a difference between OHC including toothbrushing (± CHX) compared to OHC without toothbrushing (± CHX) for the outcome of VAP (OR 0.69, 95% CI 0.36 to 1.29, P = 0.24 , I(2) = 64%) and no evidence of a difference for mortality (OR 0.85, 95% CI 0.62 to 1.16, P = 0.31, I(2) = 0%, four RCTs, moderate quality evidence). There is insufficient evidence to determine whether there is a difference due to toothbrushing for the outcomes of duration of mechanical ventilation, duration of ICU stay, use of systemic antibiotics, oral health indices, microbiological cultures, adverse effects, caregivers preferences or cost.Only one trial compared use of a powered toothbrush with a manual toothbrush providing insufficient evidence to determine the effect on any of the outcomes of this review.A range of other oral care solutions were compared. There is some weak evidence that povidone iodine mouthrinse is more effective than saline in reducing VAP (OR 0.35, 95% CI 0.19 to 0.65, P = 0.0009, I(2) = 53%) (two studies, 206 participants, high risk of bias). Due to the variation in comparisons and outcomes among the trials in this group there is insufficient evidence concerning the effects of other oral care solutions on the outcomes of this review. Effective OHC is important for ventilated patients in intensive care. OHC that includes either chlorhexidine mouthwash or gel is associated with a 40% reduction in the odds of developing ventilator-associated pneumonia in critically ill adults. However, there is no evidence of a difference in the outcomes of mortality, duration of mechanical ventilation or duration of ICU stay. There is no evidence that OHC including both CHX and toothbrushing is different from OHC with CHX alone, and some weak evidence to suggest that povidone iodine mouthrinse is more effective than saline in reducing VAP. There is insufficient evidence to determine whether powered toothbrushing or other oral care solutions are effective in reducing VAP.

Hao Z.,University of Sichuan
The Cochrane database of systematic reviews | Year: 2013

It had been assumed that suppressing the undamaged contralesional motor cortex by repetitive low-frequency transcranial magnetic stimulation (rTMS) or increasing the excitability of the damaged hemisphere cortex by high-frequency rTMS will promote function recovery after stroke. To assess the efficacy and safety of rTMS for improving function in people with stroke. We searched the Cochrane Stroke Group Trials Register (April 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 4), the Chinese Stroke Trials Register (April 2012), MEDLINE (1950 to May 2012), EMBASE (1980 to May 2012), Science Citation Index (1981 to April 2012), Conference Proceedings Citation Index-Science (1990 to April 2012), CINAHL (1982 to May 2012), AMED (1985 to May 2012), PEDro (April 2012), REHABDATA (April 2012) and CIRRIE Database of International Rehabilitation Research (April 2012). In addition, we searched five Chinese databases, ongoing trials registers and relevant reference lists. We included randomised controlled trials comparing rTMS therapy with sham therapy or no therapy. We excluded trials that reported only laboratory parameters. Two review authors independently selected trials, assessed trial quality and extracted the data. We resolved disagreements by discussion. We included 19 trials involving a total of 588 participants in this review. Two heterogenous trials with a total of 183 participants showed that rTMS treatment was not associated with a significant increase in the Barthel Index score (mean difference (MD) 15.92, 95% CI -2.11 to 33.95). Four trials with a total of 73 participants were not found to have a statistically significant effect on motor function (standardised mean difference (SMD) 0.51, 95% CI -0.99 to 2.01). Subgroup analyses of different stimulation frequencies or duration of illness also showed no significant difference. Few mild adverse events were observed in the rTMS groups, with the most common events being transient or mild headaches (2.4%, 8/327) and local discomfort at the site of the stimulation. Current evidence does not support the routine use of rTMS for the treatment of stroke. Further trials with larger sample sizes are needed to determine a suitable rTMS protocol and the long-term functional outcome.

Wang K.,University of Sichuan
Cell death & disease | Year: 2013

Stem cells are characterized by their unique ability of self-renewal to maintain the so-called stem cell pool. Over the past decades, reactive oxygen species (ROS) have been recognized as toxic aerobic metabolism byproducts that are harmful to stem cells, leading to DNA damage, senescence or cell death. Recently, a growing body of literature has shown that stem cells reside in redox niches with low ROS levels. The balance of Redox homeostasis facilitates stem cell self-renewal by an intricate network. Thus, to fully decipher the underlying molecular mechanisms involved in the maintenance of stem cell self-renewal, it is critical to address the important role of redox homeostasis in the regulation of self-renewal and differentiation of stem cells. In this regard, we will discuss the regulatory mechanisms involved in the subtly orchestrated balance of redox status in stem cells by scavenger antioxidant enzyme systems that are well monitored by the hypoxia niches and crucial redox regulators including forkhead homeobox type O family (FoxOs), apurinic/apyrimidinic (AP) endonuclease1/redox factor-1 (APE1/Ref-1), nuclear factor erythroid-2-related factor 2 (Nrf2) and ataxia telangiectasia mutated (ATM). We will also introduce several pivotal ROS-sensitive molecules, such as hypoxia-inducible factors, p38 mitogen-activated protein kinase (p38) and p53, involved in the redox-regulated stem cell self-renewal. Specifically, all the aforementioned molecules can act as 'redox sensors' by virtue of redox modifications of their cysteine residues, which are critically important in the control of protein function. Given the importance of redox homeostasis in the regulation of stem cell self-renewal, understanding the underlying molecular mechanisms involved will provide important new insights into stem cell biology.

Yang M.,University of Sichuan
The Analyst | Year: 2013

Every few years, a novel material with salient and often unique properties emerges and attracts both academic and industrial interest from the scientific community. The latest blockbuster is graphene, an increasingly important nanomaterial with atomically thin sheets of carbon, which has become a shining star and has shown great promise in the field of material science and nanotechnology. In recent years, it has changed from being the exclusive domain of physicists to the new passion of chemists and biologists. Graphene and its derivatives are now at the forefront of nearly every rapidly developing field of science and engineering, including biochemistry, biomedicine and certain cutting-edge interdisciplines that have intense popularity. The aim of this review is, firstly, to provide readers with a comprehensive, systematic and in-depth prospective of graphene's band structure and properties, and secondly, to concentrate on the recent progress in producing graphene-based nanomaterials, including mechanical exfoliation, chemical vapor deposition, plasma enhanced chemical vapor deposition, chemical reduction of graphene oxide, total organic synthesis, electrochemical synthesis and other fabrication strategies widely accepted by research scientists. At the same time, important definitions related to graphene are also introduced. The focus of this Tutorial Review is to emphasize the current situation and significance of using this new kind of two-dimensional material in the hot and emerging fields that are closely related to human life quality, for instance, cell biochemistry, bioimaging along with other frontier areas. Finally, the latest developments and possible impact that affect the heart of the whole scientific community have been discussed. In addition, the future trends along with potential challenges of this rapidly rising layered carbon have been pointed out in this paper.

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