Monoenergetic ion beam generation by driving ion solitary waves with circularly polarized laser light

Experimental data from the Trident Laser facility is presented showing quasimonoenergetic carbon ions from nm-scaled foil targets with an energy spread of as low as ±15% at 35 MeV. These results and high-resolution kinetic simulations show laser acceleration of quasimonoenergetic ion beams by the generation of ion solitons with circularly polarized laser pulses (500 fs, λ=1054  nm). The conversion efficiency into monoenergetic ions is increased by an order of magnitude compared with previous experimental results, representing an important step towards applications such as ion fast ignition.

Collective hypersonic excitations in strongly multiple scattering colloids

Unprecedented low-dispersion high-frequency acoustic excitations are observed in dense suspensions of elastically hard colloids. The experimental phononic band structure for SiO(2) particles with different sizes and volume fractions is well represented by rigorous full-elastodynamic multiple-scattering calculations. The slow phonons, which do not relate to particle resonances, are localized in the surrounding liquid medium and stem from coherent multiple scattering that becomes strong in the close-packing regime. Such rich phonon-matter interactions in nanostructures, being still unexplored, can open new opportunities in phononics.

A novel high resolution ion wide angle spectrometer

A novel ion wide angle spectrometer (iWASP) has been developed, which is capable of measuring angularly resolved energy distributions of protons and a second ion species, such as carbon C(6 +), simultaneously. The energy resolution for protons and carbon ions is better than 10% at ∼50 MeV/nucleon and thus suitable for the study of novel laser-ion acceleration schemes aiming for ultrahigh particle energies. A wedged magnet design enables an acceptance angle of 30°(∼524 mrad) and high angular accuracy in the μrad range. First, results obtained at the LANL Trident laser facility are presented demonstrating high energy and angular resolution of this novel iWASP.

Development of a high resolution and high dispersion Thomson parabola

Here, we report on the development of a novel high resolution and high dispersion Thomson parabola for simultaneously resolving protons and low-Z ions of more than 100 MeV/nucleon necessary to explore novel laser ion acceleration schemes. High electric and magnetic fields enable energy resolutions of ΔE∕E < 5% at 100 MeV/nucleon and impede premature merging of different ion species at low energies on the detector plane. First results from laser driven ion acceleration experiments performed at the Trident Laser Facility demonstrate high resolution and superior species and charge state separation of this novel Thomson parabola for ion energies of more than 30 MeV/nucleon.

Radiation-pressure acceleration of ion beams driven by circularly polarized laser pulses

We present experimental studies on ion acceleration from ultrathin diamondlike carbon foils irradiated by ultrahigh contrast laser pulses of energy 0.7 J focused to peak intensities of 5x10(19) W/cm2. A reduction in electron heating is observed when the laser polarization is changed from linear to circular, leading to a pronounced peak in the fully ionized carbon spectrum at the optimum foil thickness of 5.3 nm. Two-dimensional particle-in-cell simulations reveal that those C6+ ions are for the first time dominantly accelerated in a phase-stable way by the laser radiation pressure.

Enhanced laser-driven ion acceleration in the relativistic transparency regime

We report on the acceleration of ion beams from ultrathin diamondlike carbon foils of thickness 50, 30, and 10 nm irradiated by ultrahigh contrast laser pulses at intensities of approximately 7 x 10;{19} W/cm;{2}. An unprecedented maximum energy of 185 MeV (15 MeV/u) for fully ionized carbon atoms is observed at the optimum thickness of 30 nm. The enhanced acceleration is attributed to self-induced transparency, leading to strong volumetric heating of the classically overdense electron population in the bulk of the target. Our experimental results are supported by both particle-in-cell (PIC) simulations and an analytical model.

Laser-driven shock acceleration of ion beams from spherical mass-limited targets

We report on experimental studies of ion acceleration from spherical targets of diameter 15 microm irradiated by ultraintense (1x10(20) W/cm2) pulses from a 20-TW Ti:sapphire laser system. A highly directed proton beam with plateau-shaped spectrum extending to energies up to 8 MeV is observed in the laser propagation direction. This beam arises from acceleration in a converging shock launched by the laser, which is confirmed by 3-dimensional particle-in-cell simulations. The temporal evolution of the shock-front curvature shows excellent agreement with a two-dimensional radiation pressure model.

Effect of antagonists vs agonists on in vitro fertilization outcome

PURPOSE

To compare outcome following in vitro fertilization-embryo transfer (IVF-ET) using controlled ovarian hyperstimulation (COH) regimens using either the gonadotropin-releasing hormone (GnRH) agonist leuprolide acetate vs the GnRH antagonist ganirelix.

METHODS

Women needing IVF for conception were randomly assigned to 300 IU of gonadotropins with ganirelix used in the follicular phase when a follicle with a 14 mm average diameter was attained vs a regimen using leuprolide acetate from the mid-luteal phase of the previous cycle.

RESULTS

There were no differences found in clinical, ongoing, delivered pregnancy rates or implantation rates between groups.

CONCLUSIONS

The use of GnRH antagonists do not seem to reduce IVF outcome compared to using GnRH agonists in COH regimens.

The importance of number of blastomeres when embryos are transferred in the absence of controlled ovarian hyperstimulation

PURPOSE

To determine if the previous findings that transferring embryos with a higher number of blastomeres results in higher pregnancy rates following fresh but not frozen embryo transfer (ET) was related to the use of controlled ovarian hyperstimulation (COH) in the former but not in the latter.

METHODS

Retrospective review of pregnancy and implantation rates following fresh embryo transfer of donor egg recipient cycles (where no COH is used) vs frozen ETs during the same time period according to whether there was at least one embryo with eight blastomeres transferred or not.

RESULTS

Significantly higher pregnancy rates with an 8-cell ET in donor oocyte recipient cycles but not frozen ETs.

CONCLUSIONS

A less favorable uterine environment caused by the use of high dose gonadotropin is not responsible for the once again observed difference in higher pregnancy rates with higher blastomere number in fresh vs frozen ET. However, an effect of the gonadotropin releasing hormone analogue was not ruled out by this study.

Evidence that exclusive use of Follistim may produce better pregnancy results than the use of Gonal-F following in vitro fertilization (IVF) - embryo transfer (ET)

PURPOSE

To evaluate whether the equal mixture of human menopausal gonadotropin (hMG) to recombinant (r) follicle stimulating hormone (FSH) for controlled ovarian hyperstimulation (COH) adversely affects outcome following in vitro fertilization (IVF). Furthermore, to determine if the specific rFSH preparation used has any differing effects on outcome.

METHODS

Retrospective study of women using the luteal phase leuprolide acetate-gonadotropin COH regimen. Outcome measures included clinical and viable pregnancy rates (PRs) and implantation rates.

RESULTS

The clinical and viable PRs and implantation rates were significantly lower in the group receiving exclusively Gonal-F. Addition of hMG to the treatment protocol not only did not lower the PRs further, but in fact seemed to obviate the adverse effect of Gonal-F.

CONCLUSION

Since exclusive use of Gonal-F did not adversely affect fertilization rates or quality of embryos we suspect its exclusive use in some way makes the uterine environment less receptive.

Sperm toxicity evaluated by the overnight sperm survival test

A subnormal sperm stress test has also been associated with implantation failure despite apparently normal fertilization; however, this test is cumbersome and time-consuming. The overnight sperm survival test has been considered to possibly demonstrate lipid peroxidation abnormalities similar to the sperm stress test. The present study evaluated whether lower overnight survival scores were associated with lower pregnancy and implantation rates following in vitro fertilization-embryo transfer. The results showed no adverse effect of poor overnight survival test scores. Possibly, the overnight survival test, though similar in some respects to the sperm stress test, is not similar for properties of predicting embryo implantation defects. Corroboration that subnormal stress tests predicts implantation disorders is needed.

A study to determine if embryo cryopreservation influences the potential of rapidly growing embryos to successfully implant in uterine environments not influenced by controlled ovarian hyperstimulation

PURPOSE

To determine if transferring at least one embryo with eight blastomeres at 72 hours improves prognosis of donor oocyte recipients. The study aim was to verify if cryopreservation increases or decreases the advantage of rapidly growing embryos. The study could exclude the influence of controlled ovarian hyperstimulation (COH) on the uterine environment.

METHODS

All transfers, fresh or frozen, using exclusively embryos that resulted from fertilization of donor oocytes over a three-year period were evaluated.

RESULTS

Significantly higher pregnancy rates (PRs) and delivery rates were found in donor oocyte recipients receiving at least one eight-cell embryo compared to transfers without any eight-cell embryos. These differences were not found when comparing frozen embryo transfers (ETs). The data could not be explained by confounding variables.

CONCLUSIONS

The inclusion of at least one 8-cell embryo on day 3 fresh ET resulted in higher PRs even without the influence of COH. However, higher blastomere number did not influence frozen ET outcome.

Grey zone score for hypo-osmotic swelling test (HOST) is not associated with embryo implantation defects

PURPOSE

To evaluate the clinical significance of the grey zone range (50-59%) of the hypo-osmotic swelling test (HOST) on sperm samples.

METHODS

Clinical and viable pregnancy rates and implantantion rates following in vitro fertilization-embryo transfer (IVF-ET) were determined in couples where the male partner scored between 50-59% on the HOST. The data were further evaluated according to the discrepancy between viability and HOST. Finally, the study assigned whether treating sperm with the protein digestive enzyme chymotrypsin had any effect on pregnancy outcome.

RESULTS

Pregnancy and implantation rates were comparable for couples with grey zone HOST scores with the normal IVF rate for the center. Having a large discrepancy between viability and HOST scores had no clinical significance nor did treatment with chymotrypsin.

CONCLUSION

In contrast to HOST scores < 50% where extremely poor implantation rates are noted, grey zone scores have no clinical significance.

Treatment of sperm with subnormal host scores with chymotrypsin/viable pregnancy after IUI

Men with low hypoosmotic swelling test (HOST) scores (<50%) rarely achieve a pregnancy with intercourse or conventional intrauterine insemination (IUI) or even IVF. The defect seems to be related to a toxic factor attached to the sperm that can be transferred to the zona pellucida, which ultimately interferes with implantation. A small case series showed optimistic pregnancy outcome with treatment of the sperm with low HOST scores with chymotrypsin. However, the live pregnancy rate in 90 subsequent IUI cycles in men whose low HOST scores were improved by chymotrypsin was only 3.3%. IVF with ICSI remains the only highly effective treatment of this disorder.

Ovarian cancer in a woman previously diagnosed with endometriosis and an extremely high serum CA-125 level

PURPOSE

Follow-up of a woman with a serum CA-125 level > 1000 U/mL where laparoscopy only found endometriosis.

METHODS

Case report-- re-evaluation several years later.

RESULTS

Extensive clear-cell carcinoma of ovary with metastases leading to death.

CONCLUSION

This case suggests that bilateral oophorectomy should be performed in women not desiring any more children if the serum CA- 125 level is very high even if only endometriosis is found initially.

Finding information on herbal therapy: a guide to useful sources for clinicians

Many resources are available to patients and healthcare practitioners interested in learning about complementary and alternative medicine (CAM) therapies such as herbal medicine. This article provides a comprehensive review of herbal medicine sources that are general in scope, clinically oriented, evidence based, and focused on Western phytomedicinals. Tables list 15 books and 8 Internet sites that fulfill these criteria. Information also is provided on 4 monographs, literature databases, and many related sources that may be of interest to clinicians incorporating herbal medicines into their practice or counseling patients on the topic.

Indecisive M13 procoat protein mutants bind to SecA but do not activate the translocation ATPase

The M13 procoat protein serves as the paradigm for the Sec-independent membrane insertion pathway. This protein is inserted into the inner membrane of Escherichia coli with two hydrophobic regions and a central periplasmic loop region of 20 amino acid residues. Extension of the periplasmic loop region renders M13 procoat membrane insertion Sec-dependent. Loop regions with 118 or more residues required SecA and SecYEG and were efficiently translocated in vivo. Two mutants having loop regions of 80 and 100 residues, respectively, interacted with SecA but failed to activate the membrane translocation ATPase of SecA in vitro. Similarly, a procoat mutant with two additional glutamyl residues in the loop region showed binding to SecA but did not stimulate the ATPase. The three mutants were also defective for precursor-stimulated binding of SecA to the membrane surface. Remarkably, the mutant proteins act as competitive inhibitors of the Sec translocase. This suggests that the region to be translocated is sensed by SecA but the activation of the SecA translocation ATPase is only successful for substrates with a minimum length of the translocated region.

Hydrophobic forces drive spontaneous membrane insertion of the bacteriophage Pf3 coat protein without topological control

Bacterial integral inner membrane proteins are either translocated across the lipid bilayer using an energy-driven enzyme, such as the Sec translocase, or they might interact directly with the membrane due to hydrophobic forces. We report that the single-spanning Pf3 coat protein is spontaneously inserted into the membrane of Escherichia coli and requires the electrical component of the membrane potential (DeltaPsi) to translocate its N-terminal region. This results in a final N(out)C(in) orientation of the protein in the cytoplasmic membrane, due the potential-driven translocation of the aspartyl residue at position 18 in the hydrophilic N-terminal tail. Uncharged protein tails are only translocated when the hydrophobic transmembrane region of the protein has been extended. An extended transmembrane anchor allows membrane insertion in the absence of an electrochemical membrane potential, but also causes the loss of a strict determination of the topology.

Oligoasthenozoospermia is not associated with spontaneous abortions following in vivo pregnancies contrasting with in vitro fertilization data

Previous data showed an association between low motile density (< 10 million motile/mL) and spontaneous abortion (SAB) following in vitro fertilization-embryo transfer (IVF-ET). The purpose of this study was to determine if the same association existed following intrauterine insemination (IUI). A retrospective review of IUI pregnancies was conducted. Patients with antisperm antibodies, a low hypo-osmotic swelling (HOS) test score (< 50%), or those using donor sperm were excluded. A total of 52 couples were enrolled in the study: 34 in the normal motile density (MD) group and 18 in the low MD group. The SAB rate in the normal group was 29.4% and in the low group was 27.8%. Thus, these data fail to corroborate the conclusions reached after evaluation of IVF pregnancies that low MD is a cause of SAB. However, since there is a large difference in the number of sperm that come in contact with the oocyte following IVF versus IUI, it may be that the implantation defect is not evident until the oocyte is exposed to a certain number of abnormal sperm.

Assessing the risks and benefits of herbal medicine: an overview of scientific evidence

The use of herbal medicine is widespread and growing, with as many as 3 in 10 Americans using botanical remedies in a given year. Because many herbal medicines have significant pharmacological activity, and thus potential adverse effects and drug interactions, healthcare professionals must be familiar with this therapeutic modality. This article summarizes the history and current use of plant-based medicine and highlights the evidence of the risks and benefits associated with 6 plants: echinacea, garlic, ginger, ginkgo, St John's wort, and valerian. Therapies outside the medical mainstream tend to suffer from a dearth of research and critical evaluation. Critics and supporters alike note the conceptual and practical difficulties in studying many complementary and alternative therapies such as acupuncture, homeopathy, and meditation. Herbal medicine, however, lends itself well to standard evaluation methods. This article summarizes and evaluates evidence from randomized controlled trials and meta-analyses. We present the results of meta-analyses and subsequent randomized controlled trials for garlic and St John's wort; a comprehensive critical review and subsequent randomized controlled trials for ginkgo; and summaries of all identified randomized controlled trials for echinacea, ginger, and valerian.

A review of 12 commonly used medicinal herbs

A large and increasing number of patients use medicinal herbs or seek the advice of their physician regarding their use. More than one third of Americans use herbs for health purposes, yet patients (and physicians) often lack accurate information about the safety and efficacy of herbal remedies. Burgeoning interest in medicinal herbs has increased scientific scrutiny of their therapeutic potential and safety, thereby providing physicians with data to help patients make wise decisions about their use. This article provides a review of the data on 12 of the most commonly used herbs in the United States. In addition, we provide practical information and guidelines for the judicious use of medicinal herbs.

Evidence that oligoasthenozoospermia may be an etiologic factor for spontaneous abortion after in vitro fertilization-embryo transfer

OBJECTIVE

To evaluate whether oligoasthenozoospermia may lead to a higher spontaneous abortion (SAB) rate once a pregnancy is established by IVF-ET.

DESIGN

Retrospective clinical observational study.

SETTING

University-based IVF program.

PATIENT(S)

Three hundred sixty-four couples with normal semen parameters who underwent IVF-ET with conventional sperm incubation; 70 couples with oligoasthenozoospermia but without marked abnormal sperm morphology (< 4% normal forms using strict criteria) who underwent ET after IVF with conventional sperm incubation; and 20 couples with oligoasthenozoospermia but without abnormal sperm morphology who underwent ET after IVF with intracytoplasmic sperm injection (ICSI).

MAIN OUTCOME MEASURE(S)

Implantation rate, clinical pregnancy rate, SAB rate, and delivery rate after IVF-ET.

RESULT(S)

Despite similar pregnancy and implantation rates per ET, as a result of a higher SAB rate (40.0% versus 11.7%), the delivery rates were lower in the female partners of men with oligoasthenozoospermia. Similar patients who used ICSI had a 0% SAB rate.

CONCLUSION(S)

Oligoasthenozoospermia should be considered a possible risk factor for SAB in IVF achieved pregnancies. Further studies are needed to determine whether ICSI reduces the risk of SAB associated with oligoasthenozoospermia.