Graphene-based photocatalysts for oxygen evolution from water

Recent achievements of GR-based photocatalysts for oxygen evolution from water are summarized with perspectives on major challenges and opportunities.

Short-term pharmacokinetic study of mycophenolate mofetil in neonatal swine

BACKGROUND

Mycophenolate mofetil (MMF) is an effective immunosuppressive agent that has been frequently used in laboratory animals including swine; however, the pharmacokinetic properties of MMF in swine have not been studied. This short-term study was designed to evaluate the feasibility and the pharmacokinetic profiles of MMF therapy in neonatal swine.

MATERIALS AND METHODS

Twelve neonatal pigs were randomized into four groups including one control and three treated groups with oral MMF administered at 0.5, 1, and 2 g/m(2)/d for 4 days, divided by 2 half-doses at 9:00 and 17:00 (except day 4 during which MMF was not administered at 17:00). Blood samples were collected at 9:00 on days 0, 2, 3 and 4 for complete blood count and hepatic/renal function examination; the trough concentration of plasma mycophenolic acid (MPA) was also determined. On days 2 and 4, blood was collected to determine the area under the curve (AUC) of plasma MPA concentration. Animal body-weight growth and manifestations of MMF side-effects such as anorexia, vomiting, and diarrhea were also observed.

RESULTS

MMF has no acute hepatic/renal toxicity in newborn pigs; however, less body-weight growth was observed in treated groups. In the control group, a spontaneous increase of lymphocyte count was observed; in contrast, MMF therapy with doses of 1 and 2 g/m(2)/d reduced both lymphocyte and monocyte counts of piglets. Oral MMF had high bioavailability in neonatal swine. MPA-AUC0-12h of doses 0.5, 1, and 2 g/m(2)/d was 22.00 ± 3.32, 57.57 ± 34.30, and 140.00 ± 19.70 μg × h/mL, respectively. Neither MPA trough concentration (MPA-C0), nor MPA maximum concentration (MPA-Cmax) or MPA-AUC0-6h had high correlation with MMF-dose. For surveillance of MPA exposure, MPA-C0 had significant correlation with MPA-AUC0-12h (Spearman's ρ = 0.933, AUC0-12h = 17.882 × C0 + 14.479, r(2) = 0.966).

CONCLUSION

To reach adequate drug exposure and to reduce dose-dependent side effects, an MMF dose of 1 g/m(2)/d is recommended to be used as an initial dose for immunosuppressive therapy in piglets, and MPA-C0 monitoring is the most practical strategy for experimental transplantation study.

Improved upper limits on the stochastic gravitational-wave background from 2009-2010 LIGO and Virgo data

Gravitational waves from a variety of sources are predicted to superpose to create a stochastic background. This background is expected to contain unique information from throughout the history of the Universe that is unavailable through standard electromagnetic observations, making its study of fundamental importance to understanding the evolution of the Universe. We carry out a search for the stochastic background with the latest data from the LIGO and Virgo detectors. Consistent with predictions from most stochastic gravitational-wave background models, the data display no evidence of a stochastic gravitational-wave signal. Assuming a gravitational-wave spectrum of Ω_{GW}(f)=Ω_{α}(f/f_{ref})^{α}, we place 95% confidence level upper limits on the energy density of the background in each of four frequency bands spanning 41.5-1726 Hz. In the frequency band of 41.5-169.25 Hz for a spectral index of α=0, we constrain the energy density of the stochastic background to be Ω_{GW}(f)<5.6×10^{-6}. For the 600-1000 Hz band, Ω_{GW}(f)<0.14(f/900  Hz)^{3}, a factor of 2.5 lower than the best previously reported upper limits. We find Ω_{GW}(f)<1.8×10^{-4} using a spectral index of zero for 170-600 Hz and Ω_{GW}(f)<1.0(f/1300  Hz)^{3} for 1000-1726 Hz, bands in which no previous direct limits have been placed. The limits in these four bands are the lowest direct measurements to date on the stochastic background. We discuss the implications of these results in light of the recent claim by the BICEP2 experiment of the possible evidence for inflationary gravitational waves.

Low molecular weight polyethylenimine as a transgenic vector for tumor gene therapy

We constructed a polymer composed of a series of small molecule polyethylenimine (PEI) using 4-arm polyethylenimine (PEG) as a core for tumor gene therapy. N,N'-carbonyldiimidazole and N-succinimidyl-3-(2-pyridyldithio) propionate were used as chemical connecting reagents to synthesize 4-arm PEG-PEI2000 and 4-arm PEG-PEI2000-MC11. Chemical characterization was performed using (1)H-NMR. The retardation effect of polymers on plasmid DNA was observed using electrophoretic mobility shift and MTT assays to test the toxicity of the polymers. The gene delivery capability of 4-arm PEG-PEI2000 and 4-arm PEG-PEI2000-MC11, and the effect of MC11 were determined by an in vitro gene delivery experiment with human hepatoma HepG2 cells. At a N:P ratio of 3, the 4-arm PEG-PEI2000 could retard successfully plasmid DNA with low toxicity. In experiments in vitro, when the N:P ratio was 30, the gene delivery efficiency of 4-arm PEG-PEI2000 in HepG2 cells was five times that of PEI2000; After connecting ligand MC11, however, the gene delivery efficiency was twice as great. Free MC11 effectively inhibited the gene delivery efficiency of the 4-arm PEG-PEI2000-MC11. Four-arm PEG-PEI2000 has low toxicity and high gene delivery efficiency, and is an effective gene delivery vector after linking ligand MC11.

A mixed effects model to estimate timing and intensity of pubertal growth from height and secondary sexual characteristics

Aim

To estimate and compare pubertal growth timing and intensity in height, Tanner stage markers and testis volume.

Subjects and methods

Data on height, genital stage, breast stage and pubic hair stage, testis volume and menarche in 103 boys and 74 girls from the Edinburgh Longitudinal Growth Study were analysed. The SITAR model for height and a novel mixed effects logistic model for Tanner stage and testis volume provided estimates of peak velocity (PV, intensity) and age at peak velocity (APV, timing), both overall (from fixed effects) and for individuals (random effects).

Results

Based on the six markers, mean APV was 13.0–14.0 years in boys and 12.0–13.1 years in girls, with between-subject standard deviations of ∼1 year. PV for height was 8–9 cm/year by sex and for testis volume 6 ml/year, while Tanner stage increased by 1.2–1.8 stages per year at its peak. The correlations across markers for APV were 0.6–0.8 for boys and 0.8–0.92 for girls, very significantly higher for girls (p = 0.005). Correlations for PV were lower, −0.2–0.6.

Conclusions

The mixed effects models perform well in estimating timing and intensity in individuals across several puberty markers. Age at peak velocity correlates highly across markers, but peak velocity less so.

Search for gravitational waves associated with γ-ray bursts detected by the interplanetary network

We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M⊙c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.

Search for gravitational waves associated with γ-ray bursts detected by the interplanetary network

We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M⊙c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.

Abstract S4-07: Effects of bisphosphonate treatment on recurrence and cause-specific mortality in women with early breast cancer: A meta-analysis of individual patient data from randomised trials

Background: Disseminated tumour cells can remain dormant in the bone marrow for years prior to subsequent activation and the development of overt metastases. Bisphosphonates (BP) have profound effects on bone physiology and could potentially modify the metastatic disease process. Variable outcomes in terms of disease recurrence have been reported, with efficacy apparently influenced by menopausal status.

Methods: We sought individual patient data for meta-analysis from 41 randomised trials that compared BP to no BP (placebo or open control). Primary outcomes were time to recurrence, time to first distant recurrence and breast cancer mortality. Predefined subgroup comparisons were of type of BP (amino-/non-amino), duration and schedule of BP treatment, menopausal status, age, ER status, concomitant chemotherapy and site of distant recurrence (bone/other).

Results: Data on 17,751 women (75% of 23,573 randomised in relevant trials) have so far been received, with around 3,300 breast cancer recurrences and 2,500 deaths. Effects on breast cancer mortality, recurrence and bone metastases for 17,016 women in the locked database and for 10,540 who were postmenopausal are shown below.

No. eventsRate Ratio (SE)10 year gain2p valueAll women (n = 17,016)Breast cancer mortality2,0490.91 (0.04)1.7%0.04Breast cancer recurrence3,2840.94 (0.04)1.0%0.13Distant recurrence2,7510.92 (0.04)1.3%0.05Bone recurrence8250.79 (0.07)1.4%0.002Other distant recurrence1,9260.99 (0.05)0.1%0.8Postmenopausal women (n = 10,540)Breast cancer mortality1,1070.83 (0.06)3.1%0.004Breast cancer recurrence1,8090.86 (0.05)3.0%0.002Distant recurrence1,5030.83 (0.05)3.3%0.0007Bone recurrence4450.65 (0.08)2.9%0.00001Other distant recurrence1,0580.93 (0.06)0.7%0.26

Reductions in bone recurrence for postmenopausal women were similar irrespective of bisphosphonate type, treatment schedule, ER status, nodal involvement or use of concomitant chemotherapy. There were no improvements in bone (RR = 1.00, 2p = 0.97) or other recurrence for premenopausal women. Adjuvant bisphosphonates also reduced bone fractures (RR = 0.83, 2p = 0.009).

Conclusion: Adjuvant bisphosphonates reduce bone recurrences and improve breast cancer survival in postmenopausal but not premenopausal women.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr S4-07.

Autophagy and chemotherapy resistance: a promising therapeutic target for cancer treatment

Induction of cell death and inhibition of cell survival are the main principles of cancer therapy. Resistance to chemotherapeutic agents is a major problem in oncology, which limits the effectiveness of anticancer drugs. A variety of factors contribute to drug resistance, including host factors, specific genetic or epigenetic alterations in the cancer cells and so on. Although various mechanisms by which cancer cells become resistant to anticancer drugs in the microenvironment have been well elucidated, how to circumvent this resistance to improve anticancer efficacy remains to be defined. Autophagy, an important homeostatic cellular recycling mechanism, is now emerging as a crucial player in response to metabolic and therapeutic stresses, which attempts to maintain/restore metabolic homeostasis through the catabolic lysis of excessive or unnecessary proteins and injured or aged organelles. Recently, several studies have shown that autophagy constitutes a potential target for cancer therapy and the induction of autophagy in response to therapeutics can be viewed as having a prodeath or a prosurvival role, which contributes to the anticancer efficacy of these drugs as well as drug resistance. Thus, understanding the novel function of autophagy may allow us to develop a promising therapeutic strategy to enhance the effects of chemotherapy and improve clinical outcomes in the treatment of cancer patients.

Chimney stents for endovascular repair of juxtarenal aortic aneurysms with unfavourable anatomy

AIM

The aim of this paper was to present our experience with the use of chimney grafts in endovascular aneurysm repair (EVAR) of juxtarenal aortic aneurysms (JAA) with unfavourable anatomy.

METHODS

Between January 2001 and January 2011, 5 patients (4 men and 1 woman; mean age 78 years) with JAAs were treated with chimney grafts in the renal arteries. All the cases were at high risk for open repair and were unsuitable for standard endovascular abdominal aortic aneurysm repair because of short neck length, or large neck angulation. Six chimney stents (5 balloon expandable stents and 1 self-expandable stent) were implanted into the renal arteries.

RESULTS

The technical success was 100%. The final angiography showed excellent results, with good flow into the kidneys and complete exclusion of the aneurysm sac and no type I endoleaks. The average follow-up period was 15.8 months (range, 1-52 months). One patient died two months after surgery because of heart failure. An early small type II endoleak found in one patient resolved within three months without treatment. All chimney grafts were patent at the end of the follow-up period.

CONCLUSION

The chimney graft technique is an expansion of endovascular aortic repair (EVAR), especially suitable for juxtarenal aortic aneurysms in patients with a high surgical risk. The chimney graft technique is feasible, even in the setting of unfavourable aortic anatomy. Long-term results are still unknown.

Ethyl pyruvate ameliorates intracerebral hemorrhage-induced brain injury through anti-cell death and anti-inflammatory mechanisms

Ethyl pyruvate (EP) is a pyruvate derivative and known to be cytoprotective in various pathological conditions through anti-cell death and anti-inflammatory mechanisms. The present study investigated the neuroprotective effect of ethyl pyruvate using a mouse model of collagenase-induced intracerebral hemorrhage (ICH). Our results showed that EP treatment to mice reduced brain edema and improved neurological function after ICH. Delayed treatment with EP until 6h after ICH to mice was still neuroprotective. We further demonstrated that EP protected neurons from hemoglobin-induced cell death in vitro and neuronal cell degeneration in ICH mice. Moreover, EP exerted anti-inflammatory effects by inhibiting microglia activation, nuclear factor-κB (NF-κB) DNA binding activity and subsequent downstream pro-inflammatory cytokines (tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β)) production. Taken together, these results suggest that EP exerts neuroprotective effect via anti-cell death and anti-inflammatory actions. EP is a potential novel treatment for ICH patients and deserves further investigation.

Coupling modulation of microrings at rates beyond the linewidth limit

We demonstrate optical modulation rates exceeding the conventional cavity linewidth limit using a silicon coupling modulated microring. Small-signal measurements show coupling modulation was free of the parasitic cavity linewidth limitations at rates at least 6× the cavity linewidth. Eye diagram measurements show coupling modulation achieved data rates > 2× the rate attainable by conventional intracavity phase modulation. We propose to use DC-balanced encoding to mitigate the inter-symbol interference in coupling modulation. Analysis shows that coupling modulation can be more efficient than intracavity modulation for large output swings and high-Q resonators. Coupling modulation enables very high-Q resonant modulators to be simultaneously low-power and high-speed, features which are mutually incompatible in typical resonant modulators studied to date.

Biochemical and hematologic effects of polyvinylpyrrolidone-wrapped fullerene C60 after oral administration

The fullerene C60 is used in consumer products such as cosmetics owing to its antioxidative effects and is being developed for nanomedical applications. However, knowledge regarding the safety of fullerene C60, especially after oral administration, is sparse. Here, we examined the safety of fullerene C60 in mice after 7 d of exposure to orally administered polyvinylpyrrolidone (PVP)-wrapped fullerene C60 (PVP-fullerene C60). Mice treated with PVP-fullerene C60 showed few changes in the plasma levels of various markers of kidney and liver injury and experienced no significant hematologic effects. Furthermore, the histology of the colon of PVP-fullerene C60-treated mice was indistinguishable from that of control mice. These results suggest that PVP-fullerene C60 lacks toxicity after high-dose oral administration and indicate that PVP-fullerene C60 can be considered safe for oral medication. These data provide basic information that likely will facilitate the production of safe and effective forms of fullerene C60.