Evolution of femtosecond laser damage in a hafnia-silica multi-layer dielectric coating.

To optimize optical coating materials, designs, and technologies for high damage resistance, understanding the growth of laser damage is of paramount importance. In this Letter, we show the evolution of femtosecond laser damage in a hafnia-silica (HfO2/SiO2) multilayer dielectric mirror coating. Depending on various spatial features of damaged sites, we identified several regimes of the laser-material interaction with varying laser fluence and incident number of pulses. A change in surface roughness has been observed only for a small number of pulses, and interestingly, a threshold number of pulses is found for nanocrack formation. We report the polarization-dependent orientation of nanocracks and their growth with an increasing number of pulses. The presented results demonstrate that the laser damage originates from the nanobumps and surface roughening, which then leads to the formation of nanocracks. The presented experimental results acknowledge the existing theoretical models in bulk dielectrics to explain the formation of nanostructures by interference of the incident laser with the scattering radiation from laser-induced inhomogeneities and growth of the field enhancement due to nanoplasma.

Proton acceleration by irradiation of isolated spheres with an intense laser pulse.

We report on experiments irradiating isolated plastic spheres with a peak laser intensity of 2-3×10^{20}Wcm^{-2}. With a laser focal spot size of 10 µm full width half maximum (FWHM) the sphere diameter was varied between 520 nm and 19.3 µm. Maximum proton energies of ∼25 MeV are achieved for targets matching the focal spot size of 10 µm in diameter or being slightly smaller. For smaller spheres the kinetic energy distributions of protons become nonmonotonic, indicating a change in the accelerating mechanism from ambipolar expansion towards a regime dominated by effects caused by Coulomb repulsion of ions. The energy conversion efficiency from laser energy to proton kinetic energy is optimized when the target diameter matches the laser focal spot size with efficiencies reaching the percent level. The change of proton acceleration efficiency with target size can be attributed to the reduced cross-sectional overlap of subfocus targets with the laser. Reported experimental observations are in line with 3D3V particle in cell simulations. They make use of well-defined targets and point out pathways for future applications and experiments.

Deletion of G-protein-coupled receptor 55 promotes obesity by reducing physical activity.

BACKGROUND/OBJECTIVES: Cannabinoid receptor 1 (CB1) is the best-characterized cannabinoid receptor, and CB1 antagonists are used in clinical trials to treat obesity. Because of the wide range of CB1 functions, the side effects of CB1 antagonists pose serious concerns. G-protein-coupled receptor 55 (GPR55) is an atypical cannabinoid receptor, and its pharmacology and functions are distinct from CB1. GPR55 regulates neuropathic pain, gut, bone, immune functions and motor coordination. GPR55 is expressed in various brain regions and peripheral tissues. However, the roles of GPR55 in energy and glucose homeostasis are unknown. Here we have investigated the roles of GPR55 in energy balance and insulin sensitivity using GPR55-null mice (GPR55(-/-)). METHODS: Body composition of the mice was measured by EchoMRI. Food intake, feeding behavior, energy expenditure and physical activity of GPR55(-/-) mice were determined by indirect calorimetry. Muscle function was assessed by forced treadmill running test. Insulin sensitivity was evaluated by glucose and insulin tolerance tests. Adipose inflammation was assessed by flow cytometry analysis of adipose tissue macrophages. The expression of inflammatory markers in adipose tissues and orexigenic/anorexigenic peptides in the hypothalamus was also analyzed by real-time PCR. RESULTS: GPR55(-/-) mice had normal total energy intake and feeding pattern (i.e., no changes in meal size, meal number or feeding frequency). Intriguingly, whereas adult GPR55(-/-) mice only showed a modest increase in overall body weight, they exhibited significantly increased fat mass and insulin resistance. The spontaneous locomotor activity of GPR55(-/-) mice was dramatically decreased, whereas resting metabolic rate and non-shivering thermogenesis were unchanged. Moreover, GPR55(-/-) mice exhibited significantly decreased voluntary physical activity, showing reduced running distance on the running wheels, whereas muscle function appeared to be normal. CONCLUSIONS: GPR55 has an important role in energy homeostasis. GPR55 ablation increases adiposity and insulin resistance by selectively decreasing physical activity, but not by altering feeding behavior as CB1.

Ultrashort pulsed neutron source.

We report on a novel compact laser-driven neutron source with an unprecedented short pulse duration (<50 ps) and high peak flux (>10(18) n/cm(2)/s), an order of magnitude higher than any existing source. In our experiments, high-energy electron jets are generated from thin (<3 µm) plastic targets irradiated by a petawatt laser. These intense electron beams are employed to generate neutrons from a metal converter. Our method opens venues for enhancing neutron radiography contrast and for creating astrophysical conditions of heavy element synthesis in the laboratory.

Optimization of a universal matchbox on an ultrasonic vibrating system.

The main scope of the article is to investigate the effect of ferrite cores gap in a universal matchbox on an ultrasonic vibrating system. A gapped transformer mechanism in a universal matchbox has been thoroughly studied. Characteristics of an ultrasonic vibrating system have been recorded such as mechanical vibrations, inductance, resonant frequencies, current and voltage levels as the gap of ferrite cores gradually increases. In addition, the phase difference between the supplied voltage and the current is also computed and displayed in a Lissajous curve in order to determine the optimal gap between two ferrite cores in the universal matchbox. Explanations supplement the experiment results.

A systematic review and economic evaluation of subcutaneous and sublingual allergen immunotherapy in adults and children with seasonal allergic rhinitis.

BACKGROUND: Severe allergic rhinitis uncontrolled by conventional medication can substantially affect quality of life. Immunotherapy involves administering increasing doses of a specific allergen, with the aim of reducing sensitivity and symptomatic reactions. Recent meta-analyses have concluded that both subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) are more effective than placebo in reducing symptoms. It is uncertain which route of administration is more effective and whether or not treatment is cost-effective. OBJECTIVE: To determine the comparative clinical effectiveness and cost-effectiveness of SCIT and SLIT for seasonal allergic rhinitis in adults and children. DATA SOURCES: Electronic databases {MEDLINE, EMBASE, The Cochrane Library [Cochrane Central Register of Controlled Trials (CENTRAL)], NHS Economic Evaluation Database (NHS EED)} and trial registries (from inception up to April 2011). REVIEW METHODS: Standard systematic review methods were used for study selection, data extraction and quality assessment. Double-blind randomised, placebo-controlled trials of SCIT or SLIT, or of SCIT compared with SLIT, and economic evaluations were included. Meta-analysis and indirect comparison meta-analysis and meta-regression were carried out. A new economic model was constructed to estimate cost-utility. RESULTS: Meta-analyses found statistically significant effects for SCIT and SLIT compared with placebo across a number of outcome measures and for the vast majority of subgroup analyses (type and amount of allergen, duration of treatment). There was less evidence for children, but some results in favour of SLIT were statistically significant. Indirect comparisons did not provide conclusive results in favour of either SCIT or SLIT. Economic modelling suggested that, when compared with symptomatic treatment (ST), both SCIT and SLIT may become cost-effective at a threshold of £20,000-30,000 per quality-adjusted life-year (QALY) from around 6 years, or 5 years for SCIT compared with SLIT (NHS and patient perspective). LIMITATIONS: It is uncertain to what extent changes in the outcome measures used in the trials translate into clinically meaningful benefits. Cost-effectiveness estimates are based on a simple model, limited data and a number of assumptions, and should be seen as indicative only. CONCLUSIONS: A benefit from both SCIT and SLIT compared with placebo has been consistently demonstrated, but the extent of this effectiveness in terms of clinical benefit is unclear. Both SCIT and SLIT may be cost-effective compared with ST from around 6 years (threshold of £20,000-30,000 per QALY). Further research is needed to establish the comparative effectiveness of SCIT compared with SLIT and to provide more robust cost-effectiveness estimates. FUNDING: The National Institute for Health Research Health Technology Assessment programme.

Acute type A aortic dissection intimal tears by 64-slice computed tomography: a role for endovascular stent-grafting?

AIM: The goal of this study was to identify physical characteristics of primary intimal tears in patients arriving to the hospital alive with acute type A aortic dissection using 64-multislice computerized tomography (MSCT) in order to determine anatomic feasibility of endovascular stent-grafting (ESG) for future treatment. METHODS: Radiology database was screened for acute type A aortic dissection since the time of acquisition of the 64-slice CT scanner and cross-referenced with surgical database. Seventeen patients met inclusion criteria. Images were reviewed for number, location, and size of intimal tears and aortic dimensions. Potential obstacles for ESG were determined. RESULTS: Ascending aorta (29%) and sinotubular junction (29%) were the most frequent regions where intimal tears originated. Location of intimal tears in nearly 75% of patients was inappropriate for ESG, and 94% of patients did not have sufficient proximal or distal landing zone required for secure fixation. Only 71% of patients underwent surgical aortic dissection repair after imaging and 86% of entry tears detected on MSCT were confirmed on intraoperative documentation. Only one patient would have met all technical criteria for ESG using currently available devices. CONCLUSION: Location of intimal tear, aortic valve insufficiency, aortic diameter>38 mm are major factors limiting use of ESG for acute type A dissection. Available stents used to treat type B aortic dissection do not address anatomic constraints present in type A aortic dissection in the majority of cases, such that development of new devices would be required.

Biological effects after prenatal irradiation (embryo and fetus). A report of the International Commission on Radiological Protection.

In its 1990 recommendations, the ICRP considered the radiation risks after exposure during prenatal development. This report is a critical review of new experimental animal data on biological effects and evaluations of human studies after prenatal radiation published since the 1990 recommendations.Thus, the report discusses the effects after radiation exposure during pre-implantation, organogenesis, and fetogenesis. The aetiology of long-term effects on brain development is discussed, as well as evidence from studies in man on the effects of in-utero radiation exposure on neurological and mental processes. Animal studies of carcinogenic risk from in-utero radiation and the epidemiology of childhood cancer are discussed, and the carcinogenic risk to man from in-utero radiation is assessed. Open questions and needs for future research are elaborated. The report reiterates that the mammalian embryo and fetus are highly radiosensitive. The nature and sensitivity of induced biological effects depend upon dose and developmental stage at irradiation. The various effects, as studied in experimental systems and in man, are discussed in detail. It is concluded that the findings in the report strengthen and supplement the 1990 recommendations of the ICRP.

Use of 7/0 Vicryl (coated polyglactin 910) and 7/0 Vicryl-rapide (irradiated polyglactin 910) in skin closure in ophthalmic plastic surgery.

AIMS: To assess the safety and efficacy of 7/0 Vicryl and 7/0 Vicryl rapide sutures for skin closure, and without suture removal, in ophthalmic plastic surgery. METHOD: A prospective, comparative study of 40 consecutive procedures in 32 patients. Tissue reactions to the sutures, completeness of wound healing, and number of sutures remaining were observed at first dressing, 2 weeks and 2 months. RESULTS: Wound healing was excellent at 2 weeks in all but one Vicryl rapide patient whose slight wound gape was not attributable to the suture material used. No inflammatory tissue reaction attributable to the suture was seen. No visible suture marks were observed at 2 months. Transient crusting was observed around the sutures in 9/20 (45%) and 10/20 (50%) patients with Vicryl and Vicryl rapide, respectively. Only one suture out of 144 was removed. CONCLUSION: 7-0 Vicryl and 7-0 Vicryl rapide are safe and effective sutures for skin closure in ophthalmic plastic surgery.

Long-term follow-up of short intensive multiagent chemotherapy without high-dose methotrexate ('Orange') in children with advanced non-lymphoblastic non-Hodgkin's lymphoma: a children's cancer group report.

Despite prolonged therapy (18 months), children with advanced non-lymphoblastic, non-Hodgkin's lymphoma (NHL) treated on previous Children's Cancer Group (CCG) trials achieved less than a 60% 5-year event-free survival (EFS). In this study we piloted a shorter but more intensive protocol ('Orange') to determine the feasibility, safety, and efficacy of this alternative treatment approach. Thirty-nine children received a CHOP-based induction, etoposide/ifosfamide consolidation, DECAL (dexamethasone, etoposide, cisplatin, cytosine arabinoside (Ara-C) and L-asparaginase) intensification, and either one or two similar but less intense maintenance courses. Patients were stratified to standard-risk (5 months) vs high-risk (7 months) treatment. High risk was defined as either bone marrow disease, CNS disease, mediastinal mass > or = one-third thoracic diameter at T5 and/or LDH > or =2 times institutional upper limits of normal. All other patients were considered to be standard risk. Results were compared with the previous CCG NHL study (CCG-503). Sixteen and 23 patients were considered standard- vs. high-risk, respectively. The 5-year EFS and overall survival (OS) were 77 +/- 7% and 80 +/- 7%, respectively. The 5-year EFS and OS were significantly better in the standard- vs. high-risk subgroups (100% vs. 61 +/- 11%) (P < 0.003) and (100% vs. 65 +/- 11%) (P < 0.01), respectively. Lactate dehydrogenase (LDH) > or =2 x normal (NL) was associated with significantly poorer outcomes (LDH > or =2 x NL vs. <2 x NL) (5-year EFS: 55 +/- 12% vs. 100%) (P < 0.0004). This CCG hybrid regimen, 'Orange', of short and more intensive therapy resulted in a significant improvement in outcomes compared with the previous CCG trial of more prolonged but less intense therapy. This regimen that deletes high-dose methotrexate, if confirmed in a larger trial, could be considered as an alternative treatment approach in children without high tumor burdens (LDH <2 x NL) and Murphy stage III disease.

Comparison of long-term outcome of children and adolescents with disseminated non-lymphoblastic non-Hodgkin lymphoma treated with COMP or daunomycin-COMP: A report from the Children's Cancer Group.

BACKGROUND: Early Children's Cancer Group (CCG) trials indicated that the cyclophosphamide, vincristine, methotrexate, and prednisone (COMP) regimen was superior to the LSA2L2 regimen for non-lymphoblastic (NLB) non-Hodgkin lymphoma (NHL). Studies by other groups suggested that addition of anthracyclines to standard therapies could improve outcome. Therefore, in 1983 CCG initiated study CCG-503, a randomized trial of COMP vs. daunomycin-COMP (D-COMP) in children and adolescents with disseminated NLB NHL. PROCEDURES: Between December 1983 and April 1990, 404 eligible patients were entered. Patients without central nervous system (CNS) or marrow involvement were randomized to receive COMP (N = 139) or D-COMP (N = 145). Randomization was stratified by histology and site of disease. Patients with CNS or marrow involvement (stage IV) were non-randomly treated with D-COMP (N = 120). RESULTS: Ten-year event-free survival in COMP and D-COMP patients was similar: 55 +/- 4.3% (Estimate +/- SE) vs. 57 +/- 4.2% (not significant). Stage I-III patients with large-cell (LC) NHL had worse 10-year event-free survival (EFS) (48 +/- 4.9%) than those with small non-cleaved cell (SNCC) NHL disease (61 +/- 3.5%, P < 0.05 in multivariate analysis), but equivalent survival (65 +/- 4.7% vs. 63 +/- 3.5%) due to significantly higher salvage rates in LC patients, especially those failing more than 12 months from diagnosis. Ten-year EFS in stage IV patients was 39 +/- 5.2%. Addition of daunomycin resulted in higher rates of grade 3/4 hematologic toxicity and stomatitis, as well as late cardiac-related deaths. The incidence of second malignant neoplasms was 1.0% at 10 years. CONCLUSIONS: Addition of daunomycin to standard COMP therapy did not improve outcome in pediatric disseminated NLB NHL. Patients with LC disease had a significantly reduced long-term EFS, but were retrieved at a higher rate than patients with SNCC disease, resulting in equivalent long-term survival.

Chemoreduction for retinoblastoma may prevent intracranial neuroblastic malignancy (trilateral retinoblastoma).

OBJECTIVE: To evaluate whether neoadjuvant intravenous chemotherapy (chemoreduction) for retinoblastoma reduces the risk for associated intracranial neuroblastic tumor (trilateral retinoblastoma). DESIGN: Retrospective consecutive case series. PARTICIPANTS: Two hundred fourteen consecutive children with newly diagnosed retinoblastoma treated at a major ocular oncology center from January 1, 1995, to July 1, 1999. MAIN OUTCOME MEASURE: Development of associated intracranial neuroblastic tumor (trilateral retinoblastoma). RESULTS: During the 54-month study period, 142 patients (66%) received chemoreduction (consisting of vincristine sulfate, etoposide phosphate, and carboplatin therapy) as part of their treatment strategy (chemoreduction group), whereas 72 (34%) were treated with nonchemoreduction methods (nonchemoreduction group). In the chemoreduction group, no associated intracranial neuroblastic tumor developed during the mean 47-month follow-up. Based on a recent meta-analysis of the prevalence of trilateral retinoblastoma, we would have expected the intracranial tumor to develop in 5 to 15 patients with hereditary retinoblastoma. This lack of associated trilateral retinoblastoma in the chemoreduction group was significantly less than expected using binomial distribution (P<.001). In the nonchemoreduction group, associated intracranial tumor (pinealoblastoma) developed in 1 patient, a finding consistent with the expected frequency. CONCLUSION: Chemoreduction protects against the highly fatal associated intracranial neuroblastic tumor (trilateral retinoblastoma). This observation is especially important in children with bilateral or familial retinoblastoma who are at greatest risk for this brain tumor.

Outcomes of treatment of children and adolescents with recurrent non-Hodgkin's lymphoma and Hodgkin's disease with dexamethasone, etoposide, cisplatin, cytarabine, and l-asparaginase, maintenance chemotherapy, and transplantation: Children's Cancer Group Study CCG-5912.

PURPOSE: To determine the toxicity and response rate in children treated with dexamethasone, etoposide, cisplatin, high-dose cytarabine, and L-asparaginase (DECAL) for recurrent non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD). PATIENTS AND METHODS: Ninety-seven children with recurrent NHL (n = 68) or HD (n = 29) were enrolled. Treatment consisted of two cycles of DECAL, then bone marrow transplantation or up to four cycles of ifosfamide, mesna, and etoposide alternating with DECAL maintenance therapy. RESULTS: After two cycles of DECAL induction therapy, complete response (CR) or partial response (PR) was reported in 19 (65.5%; 10 CRs and nine PRs) of 29 patients with HD and 29 (41.6%; 23 CRs and six PRs) of 68 patients with NHL. When only 24 patients with HD and 58 patients with NHL who were assessable for response were considered, the response rates were 79.2% (19 of 24 patients) and 50.0% (29 of 58 patients), respectively. Five-year event-free survival was 26% +/- 9% and 23% +/- 5% in patients with HD and NHL, respectively. Five-year survival was 31% +/- 14% and 30% +/- 6%, respectively. Although median time to treatment failure was significantly longer in patients with HD (EFS, P =.002; survival, P =.011), this difference did not translate into a higher long-term survival. Grade 3 or 4 toxic effects were observed during induction in 70 (72%) of 97 patients and during maintenance in 45 (70%) of 64 courses of DECAL therapy. Pancytopenia and systemic infections in particular were frequently observed. Other toxic effects were uncommon. Although not a formal part of the therapy or the study design, 42 patients who responded to therapy who underwent bone marrow transplant did not show any benefit from this approach. CONCLUSION: DECAL is an effective and tolerable salvage regimen for treating patients with recurrent NHL and HD.

Second malignant neoplasms in five-year survivors of childhood cancer: childhood cancer survivor study.

BACKGROUND: Because survival rates among childhood cancer patients are increasing, assessing the risk of second and subsequent malignant neoplasms (SMNs) is ever more important. Using the Childhood Cancer Survivor Study cohort, we identified the risk of SMNS: METHODS: A retrospective cohort of 13 581 children diagnosed with common cancers before age 21 years and surviving at least 5 years was constructed with the use of data from patients treated at 25 U.S. and Canadian institutions. SMNs were ascertained through self-administered questionnaires and verified by pathology reports. Information on therapeutic exposures was abstracted from medical records. The risk of SMN was evaluated by standardized incidence ratios (SIRs) and excess absolute risk. Poisson multiple regression models were used to assess the impact of host and therapy factors on the risk of developing SMNS: All statistical tests were two-sided. RESULTS: In 298 individuals, 314 SMNs were identified (SIR = 6.38; 95% confidence interval [CI] = 5.69 to 7.13). The largest observed excess SMNs were bone and breast cancers (SIR = 19.14 [95% CI = 12.72 to 27.67] and SIR = 16.18 [95% CI = 12.35 to 20.83], respectively). A statistically significant excess of SMNs followed all childhood cancers. In multivariate regression models adjusted for therapeutic radiation exposure, SMNs of any type were independently associated with female sex (P<.001), childhood cancer at a younger age (P for trend <.001), childhood Hodgkin's disease or soft-tissue sarcoma (P<.001 and P =.01, respectively), and exposure to alkylating agents (P for trend =.02). Twenty years after the childhood cancer diagnosis, the cumulative estimated SMN incidence was 3.2%. However, only 1.88 excess malignancies occurred per 1000 years of patient follow-up. CONCLUSIONS: Success in treating children with cancer should not be overshadowed by the incidence of SMNS: However, patients and health-care providers must be aware of risk factors for SMNs so that surveillance is focused and early prevention strategies are implemented.