Mass measurements of very neutron-deficient Mo and Tc isotopes and their impact on rp process nucleosynthesis

The masses of ten proton-rich nuclides, including the N=Z+1 nuclides ⁸⁵Mo and ⁸⁷Tc, were measured with the Penning trap mass spectrometer SHIPTRAP. Compared to the Atomic Mass Evaluation 2003 a systematic shift of the mass surface by up to 1.6 MeV is observed causing significant abundance changes of the ashes of astrophysical x-ray bursts. Surprisingly low α separation energies for neutron-deficient Mo and Tc are found, making the formation of a ZrNb cycle in the rp process possible. Such a cycle would impose an upper temperature limit for the synthesis of elements beyond Nb in the rp process.

Establishment of primary human esophageal xenografts: Rationale for selection and cancer model

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Background: New animal models of esophageal cancer are required to accelerate research into novel treatment strategies. Mouse xenografts used in pre-clinical drug testing are typically derived from cell lines, but several esophageal cancer cell lines have been contaminated (PMID 20075370). Xenografts implanted from surgically resected human tumors are a potentially viable model, and may better recapitulate the characteristics of the original tumor. We describe the feasibility of such an approach.

Methods: 2-10 mm esophageal carcinoma fragments obtained from resected patient tumors were implanted directly into NOD/SCID mice. Tumors that grew beyond 1.5 cm in diameter were passaged serially. Pathologic properties were assessed from passage to passage. Potential clinicopathological predictors of engraftment were evaluated.

Results: Of the 63 patients with tumors used for implantation, 67% were male; median age 66 (range 31-89); 31% node negative disease; 69% node positive disease; 12% metastatic; 55% received neoadjuvant therapy; 12% had prior Barrett's esophagus; 46% had pre-existing heartburn; 88% were distal esophageal/GE junction cancers. Engraftment occurred in 14/43 (33%) adeno-, 1/14 (7%) squamous, and 1/1 adenosquamous carcinomas (p=0.05; 5 others were rare tumors e.g. granular or small cell). Engraftment occurred in 6/31 well/moderately vs 7/18 poorly differentiated tumors (p=0.08). Because we amended our implantation procedures, we compared engraftment rates pre- (7/39; 18%) and post-amendment (8/23; 35%; p=0.13). The primary architecture of the xenografted tissue remained similar pathologically for up to 5+ passages. None of the following variables predicted for engraftment (p>0.20 each comparison): cancer location, age, gender, history of heartburn, pre-operative therapy, presence of Barrett's esophagus, disease stage, or recurrence of primary cancer.

Conclusions: Creation of esophageal cancer xenografts from primary human resected specimens is feasible. Adenocarcinomas, higher tumor grade, and newer implantation strategies were associated with improved engraftment. We are treating these models with chemotherapy to discover new pharmacogenomic predictive biomarkers.

No significant financial relationships to disclose.

Discovery of highly excited long-lived isomers in neutron-rich hafnium and tantalum isotopes through direct mass measurements

A study of cooled ¹⁹⁷Au projectile-fragmentation products has been performed with a storage ring. This has enabled metastable nuclear excitations with energies up to 3 MeV, and half-lives extending to minutes or longer, to be identified in the neutron-rich nuclides ¹⁸³(,)¹⁸⁴(,)¹⁸⁶Hf and ¹⁸⁶(,)¹⁸⁷Ta. The results support the prediction of a strongly favored isomer region near neutron number 116.

Risk factors associated with smoking behaviour in recreational venues: findings from the International Tobacco Control (ITC) China Survey

OBJECTIVE

To explore the determinants of smoking behaviour in recreational venues and to provide scientific bases for establishing smoke-free measures applying to these locations.

METHODS

The International Tobacco Control (ITC) China Survey--a face-to-face cross-sectional survey of representative adult smokers from six cities (Shenyang, Beijing, Shanghai, Guangzhou, Changsha and Yinchuan)--was conducted between April and August 2006. A total of 4815 smokers were selected using multistage sampling methods, and final analyses were conducted on 2875 smokers who reported patronising recreational venues at least once in the last six months. Multivariate logistic regression models were used to identify factors influencing the smoking behaviour within recreational settings. Outcome measure Whether a smoker reported smoking in recreational venues during the last 6 months.

RESULTS

84% subjects reported smoking in recreational venues. Analyses showed that smoke-free laws had been exempted, 32.0% of the patrons reporting bans on smoking in these locations. The following factors were significant predictors of smoking in recreational venues: absence of bans on smoking, support for non-bans, being aged 18-24 years, positive smoking-related attitudes, low number of health effects reported and not living in Beijing.

CONCLUSIONS

The findings point to the importance of informing Chinese smokers about the active smoking and passive smoking harmfulness in both building support for smoke-free laws and in reducing smokers' desire to smoke within recreational venues. They also point to the importance of good enforcement of smoke-free laws when implemented. Such strategies could also serve to de-normalise smoking in China, a key strategy for reducing smoking in general.

Time-dependent theoretical model for terahertz wave detector using a parametric process

We have presented a time-dependent theoretical model to describe the time behavior of a quasi-monochromatic nanosecond terahertz detector reported by Guo et al. [Appl. Phys. Lett. 93, 021106 (2008)]. The temporal input-output characteristic of the detector is investigated numerically by taking the system parameters close to the experimental ones, and the calculated pulse width for the incident terahertz wave agrees well with the experimental one. Our results demonstrate that the energy and width of an output idler wave pulse are proportional to those of the incident terahertz wave pulse. This study provides a strict theoretical basis and could be used to guide the design and optimization for the highly sensitive coherent terahertz detector.

Hydrostatic isolated limb perfusion with adeno-associated virus vectors enhances correction of skeletal muscle in Pompe disease

Glycogen storage disease type II (GSD-II; Pompe disease; MIM 232300) stems from the inherited deficiency of acid-α-glucosidase (GAA; acid maltase; EC 3.2.1.20), which primarily involves cardiac and skeletal muscles. We hypothesized that hydrostatic isolated limb perfusion (ILP) administration of an adeno-associated virus (AAV) vector containing a muscle specific promoter could achieve relatively higher transgene expression in the hindlimb muscles of GAA-knockout (GAA-KO) mice, in comparison with intravenous (IV) administration. ILP adminstration of AAV2/8 vectors encoding alkaline phosphatase or human GAA transduced skeletal muscles of the hindlimb widely, despite the relatively low number of vector particles administered (1×10¹¹), and IV administration of an equivalent vector dose failed to transduce skeletal muscle detectably. Similarly, ILP administration of fewer vector particles of the AAV2/9 vector encoding human GAA (3×10¹⁰) transduced skeletal muscles of the hindlimb widely and significantly reduced glycogen content to, in comparison with IV administration. The only advantage for IV administration was moderately high level transduction of cardiac muscle, which demonstrated compellingly that ILP administration sequestered vector particles within the perfused limb. Reduction of glycogen storage in the extensor digitorum longus demonstrated the potential advantage of ILP-mediated delivery of AAV vectors in Pompe disease, because type II myofibers are resistant to enzyme replacement therapy. Thus, ILP will enhance AAV transduction of multiple skeletal muscles while reducing the required dosages in terms of vector particle numbers.

Bioterrorism and invasive species

The risk of dispersing invasive species, especially human pathogens, through acts of bioterrorism, cannot be neglected. However, that risk appears quite low in comparison with the risk of dispersing animal pathogens that could dramatically burden the agricultural economy of food animal producing countries, such as Australia and countries in Europe and North and South America. Although it is not directly related to bioterrorism, the intentional release of non-native species, particularly undesired companion animals or wildlife, may also have a major economic impact on the environment and, possibly, on animal and human health, in the case of accidental release of zoonotic agents.

A tunable radio-frequency magnetic probe

A tunable center-tapped transformer is proposed to increase the output of a rf magnetic probe and improve the signal-to-noise ratio. The tuning is implemented by a variable capacitor connected parallel with the primary winding of the tunable center-tapped transformer. Undesirable common-to-differential conversion is reduced by installing a compensating capacitor. In addition, a planar Faraday shield is installed between the windings of the transformer to further suppress the electrostatic coupling. It is found that tuning the variable capacitor can result in a resonance in the output voltage of the rf magnetic probe. The largest output voltage, achieved with the tunable magnetic probe under the optimal condition, is higher than that with a conventional one by an order of magnitude. Effects of the compensating capacitance on the common-mode output voltage are studied and discussed. Influences of parameters such as cable length, the coupling coefficient, and the step-up ratio of the transformer on the output voltage are also presented. Analytical derivations and numerical calculations based on the equivalent circuit are performed to elucidate the characteristics of the differential mode.

Incidence, management and mortality of acute hypoxemic respiratory failure and acute respiratory distress syndrome from a prospective study of Chinese paediatric intensive care network

AIM

To investigate the incidence, clinical management, mortality and its risk factors, major outcome and costs of acute hypoxemic respiratory failure (AHRF) and acute respiratory distress syndrome (ARDS) in a Chinese network of 26 paediatric intensive care unit (PICU).

METHODS

In a consecutive 12-month period, AHRF and ARDS were identified and followed up for 90 days or until death or discharge.

RESULTS

From a total of 11 521 critically ill patients, 461 AHRF were identified in which 306 developed ARDS (66.4%), resulting in incidences of 4% and 2.7%, respectively, with pneumonia (75.1%) and sepsis (14.7%) as main underlying diseases and 83% were 5 years and 1 month-old. In-hospital mortality of AHRF was 41.6% (44.8% for ARDS), accounted for 15.5% of all PICU deaths. For those of pneumonia or sepsis with AHRF and ARDS, mortality and its relative risk were significantly higher than those without. Relatively lower tidal volume and total fluid balance, adequate upper limit of PaCO(2) in the early PICU days, and family affordability, tended to result in better outcome.

CONCLUSION

In this prospective study, AHRF had high possibilities to develop ARDS and death risk, as impacted by ventilation settings and fluid intake in the early treatment, as well as socioeconomic factors, which should be considered for implementation of standard of care in respiratory therapy.

Abdominal compartment syndrome associated with capillary leak syndrome after liver transplantation

Orthotopic liver transplantation was performed in a 49-year-old man with metastatic liver sarcoma. After surgery, both abdominal compartment syndrome (ACS) and capillary leak syndrome (CLS) developed. Exploratory laparotomy and colon exteriorization were performed. Five days later, a diagnosis of severe CLS was established, and hydroxyethyl starch was infused to prevent leakage of albumin. The patient gradually recovered over 3 weeks. Awareness of ACS and CLS is important to improve outcome because early diagnosis and immediate therapy are essential. Bladder pressure is a key factor in diagnosing ACS, and pressure of 35 mm Hg is an indication for decompressive laparotomy. During the early stage of CLS, hydroxyethyl starch but not albumin should be used to alleviate edema and hypoalbuminemia.

Mesenchymal stem cells inhibition of chronic ethanol-induced oxidative damage via upregulation of phosphatidylinositol-3-kinase/Akt and modulation of extracellular signal-regulated kinase 1/2 activation in PC12 cells and neurons

It is well known that chronic ethanol consumption damages CNS through oxidative stress which results in many dysfunctions. Recently, it has been demonstrated that as a promising strategy to treat several neurological diseases, transplanted bone marrow-derived mesenchymal stem cells (MSCs) can secrete lots of protective factors that in turn promote function recovery. In the present study, we assessed the potential effects of MSCs conditioned medium (MSC-CM) against chronic ethanol-associated damage on PC12 cells and primary cortical neurons. We found that pretreatment with MSC-CM notably improved cell survival, prevented chronic ethanol-associated apoptosis and abolished the robust deterioration in oxidative status. In addition, we also discovered that chronic ethanol exposure induced an inactivation of phosphatidylinositol-3-kinase (PI3K)/Akt and a lasting activation of extracellular signal-regulated kinase 1/2 (ERK1/2) in both PC12 cells and primary cortical neurons which were able to be reversed by MSC-CM. The PI3K inhibitor (LY294002) was able to reduce the antioxidative and cytoprotective effects conferred by MSC-CM, in part, and the ERK1/2 inhibitor (PD98059) was able to elicit significant protection from chronic ethanol cytotoxicity but not rescue the deterioration in oxidative status induced by chronic ethanol. Taken together, these findings provide the first evidence that MSCs might have potent antioxidant action to shield the apoptotic impairment from chronic ethanol exposure in PC12 cells and neurons, which is involved in upregulation of PI3K/Akt and modulation of ERK1/2 activation, at least partially.