Tissue-specific dose equivalents of secondary mesons and leptons during galactic cosmic ray exposures for mars exploration

During a human mission to Mars, astronauts would be continuously exposed to galactic cosmic rays (GCR) consisting of high energy protons and heavier ions coming from outside our solar system. Due to their high energy, GCR ions can penetrate spacecraft and space habitat structures, directly reaching human organs. Additionally, they generate secondary particles when interacting with shielding materials and human tissues. Baryon secondaries have been the focus of many previous studies, while meson and lepton secondaries have been considered to a much lesser extent. In this work, we focus on assessing the tissue-specific dose equivalents and the effective dose for males of secondary mesons and leptons for the interplanetary cruise phase and the surface phase on Mars. We also provide the energy distribution of the secondary pions in each human organ since they are dominant compared to other mesons and leptons. For this calculation, the PHITS3.27 Monte Carlo simulation toolkit is used to compute the energy spectra of particles in organs in a realistic human phantom. Based on the simulation data, the dose equivalent has been estimated with radiation quality factors in ICRP Publication 60 and in the latest NASA Space Cancer Risk model (NSCR-2022). The effective dose is then assessed with the tissue weighting factors in ICRP Publication 103 and in the NSCR model, separately. The results indicate that the contribution of secondary mesons and leptons to the total effective dose is 6.1 %, 9.1 %, and 11.3 % with the NSCR model in interplanetary space behind 5, 20, and 50 g/cm2 aluminum shielding, respectively, with similar values using the ICRP model. The outcomes of this work lead to an improved understanding of the potential health risks induced by secondary particles for exploration missions to Mars and other destinations.

Cancer and circulatory disease risks for the largest solar particle events in the space age

In this paper we use the NASA Space Cancer Risk (NSCR version 2022) model to predict cancer and circulatory disease risks using energy spectra representing the largest SPE's observed in the space age. Because tissue dose-rates behind shielding for large SPE's lead to low dose-rates (<0.2 Gy/h) we consider the integrated risk for several historical periods of high solar activity, including July-November, 1960 events and August-October 1989 events along with the February 1956 and August 1972 events. The galactic cosmic ray (GCR) contribution to risks is considered in predictions. Results for these largest historical events show risk of exposure induced death (REID) are mitigated to < 1.2 % with a 95 % confidence interval with passive radiation shielding of 20 g/cm2 aluminum, while larger amounts would support the application of the ALARA principle. Annual GCR risks are predicted to surpass the risks from large SPEs by ∼30 g/cm2 of aluminum shielding.

Isotopic production cross sections in proton-16O and proton-12C interactions for energies from 10 MeV/u to 100 GeV/u

Proton interactions with 16O or 12C nuclei are frequent nuclear interaction leading to secondary radiation in tissues for space radiation and cancer therapy with protons or ion beams. The fragmentation of these ions by protons produces a large number of heavy ion (A>4) target or projectile fragments often with high ionization density. Here we develop an analytical model of energy dependent proton-16O and proton-12C cross sections for isotopic nuclei production. Using experimental data and a 2nd order optical model an accurate formula for the absorption cross section from <10 MeV/u to >10 GeV/u is obtained. The energy dependence of the elemental and isotopic cross sections is modeled as multiplicities scaled to absorption cross section with average isotopic fractions estimated from experimental data. We show that this approach results in accurate analytic formulae for isotopic fragmentation cross sections over the full energy range in hadron therapy and space radiation protection studies.

Comparison between PHITS and GEANT4 Simulations of the Heavy Ion Beams at the BEVALAC at LBNL and the Booster Accelerator at BNL

Heavy charged particles have been discussed for clinical use due to their superior dose-depth distribution compared to conventional radiation such as X-rays. In addition, high-charge and energy (HZE) ions in galactic cosmic rays (GCR) present important health risks for crewed space missions to the Earth's moon or Mars. Experiments at heavy ion accelerators are used in radiobiology studies; however, numerical simulations of track segment or Bragg peak irradiations are complicated by the details of the beam-line and dosimetry systems. The goal of the present work is in support of biophysics modeling of historical radiobiology data at Lawrence Berkeley National Laboratory (LBNL) and more recent results from the Brookhaven National Lab (BNL) facility (NASA Space Radiation Lab (NSRL)). In this work, the Spread-Out Bragg Peak (SOBP) of 4He, 12C, and 20Ne particles, and a Bragg curve of 56Fe ion have been simulated numerically in the geometries of LBNL and BNL using the Monte-Carlo based PHITS and GEANT4 simulation toolkits. The dose contributions of primary particles and secondary particles, including neutrons and photons, in the target material are computed and discussed as well. Comparisons suggest more contributions of secondaries in GEANT4 simulations compared to PHITS simulations, and less statistical fluctuation and better prediction of neutrons in PHITS simulations. Neutrons and gamma-rays are estimated to make minor contributions to absorbed doses for these beams.

Tentonin 3/TMEM150C senses blood pressure changes in the aortic arch

The baroreceptor reflex is a powerful neural feedback that regulates arterial pressure (AP). Mechanosensitive channels transduce pulsatile AP to electrical signals in baroreceptors. Here we show that tentonin 3 (TTN3/TMEM150C), a cation channel activated by mechanical strokes, is essential for detecting AP changes in the aortic arch. TTN3 was expressed in nerve terminals in the aortic arch and nodose ganglion (NG) neurons. Genetic ablation of Ttn3 induced ambient hypertension, tachycardia, AP fluctuations, and impaired baroreflex sensitivity. Chemogenetic silencing or activation of Ttn3+ neurons in the NG resulted in an increase in AP and heart rate, or vice versa. More important, overexpression of Ttn3 in the NG of Ttn3-/- mice reversed the cardiovascular changes observed in Ttn3-/- mice. We conclude that TTN3 is a molecular component contributing to the sensing of dynamic AP changes in baroreceptors.

Progress in ITER ECE Diagnostic Design and Integration

The ITER Electron Cyclotron Emission (ECE) diagnostic is progressing towards its Preliminary Design Review (PDR). In parallel, the diagnostic integration in the Equatorial Port is ongoing. Port Integration has to address the structural integrity to withstand various loads, maintenance and the safety aspects of ECE diagnostic. The ITER ECE system includes radial and oblique lines-of-sight. Recently, a successful peer-review of the in-port plug Hot Calibration Source has taken place and its performance and integration feasibility has been demonstrated. Four 45-meter long low-loss transmission lines are designed to transmit mm-wave power in the frequency range of 70- 1000 GHz in both X- and O-mode polarization from the port plug to the ECE instrumentation room in the diagnostic building. Prototype transmission lines are being tested [1]. A prototype polarizing Martin-Puplett type Fourier Transform Spectrometer (FTS) operating in the frequency range 70-1000 GHz, has a fast scanning mechanism and a cryo-cooled dual-channel THz detector system. Its performance has been tested as per ITER requirements. Assessment of the instrumentation and control requirements, functional and non-functional requirements, operation procedures, plant automation are ongoing for the PDR. The current status of the diagnostic, together with integration activities, is presented.

VUV spectroscopy in impurity injection experiments at KSTAR using prototype ITER VUV spectrometer

The ITER vacuum ultra-violet (VUV) core survey spectrometer has been designed as a 5-channel spectral system so that the high spectral resolving power of 200-500 could be achieved in the wavelength range of 2.4-160 nm. To verify the design of the ITER VUV core survey spectrometer, a two-channel prototype spectrometer was developed. As a subsequent step of the prototype test, the prototype VUV spectrometer has been operated at KSTAR since the 2012 experimental campaign. From impurity injection experiments in the years 2015 and 2016, strong emission lines, such as Kr xxv 15.8 nm, Kr xxvi 17.9 nm, Ne vii 46.5 nm, Ne vi 40.2 nm, and an array of largely unresolved tungsten lines (14-32 nm) could be measured successfully, showing the typical photon number of 10¹³-10¹⁵ photons/cm² s.

Test of prototype ITER vacuum ultraviolet spectrometer and its application to impurity study in KSTAR plasmas

To optimize the design of ITER vacuum ultraviolet (VUV) spectrometer, a prototype VUV spectrometer was developed. The sensitivity calibration curve of the spectrometer was calculated from the mirror reflectivity, the grating efficiency, and the detector efficiency. The calibration curve was consistent with the calibration points derived in the experiment using the calibrated hollow cathode lamp. For the application of the prototype ITER VUV spectrometer, the prototype spectrometer was installed at KSTAR, and various impurity emission lines could be measured. By analyzing about 100 shots, strong positive correlation between the O VI and the C IV emission intensities could be found.

Development of the prototype pneumatic transfer system for ITER neutron activation system

The neutron activation system (NAS) measures neutron fluence at the first wall and the total neutron flux from the ITER plasma, providing evaluation of the fusion power for all operational phases. The pneumatic transfer system (PTS) is one of the key components of the NAS for the proper operation of the system, playing a role of transferring encapsulated samples between the capsule loading machine, irradiation stations, counting stations, and disposal bin. For the validation and the optimization of the design, a prototype of the PTS was developed and capsule transfer tests were performed with the developed system.

Integration of HIV testing in tuberculosis drug resistance surveillance in Kazakhstan and Kenya

In Kenya and Kazakhstan, integration of human immunodeficiency virus (HIV) testing results into the routine surveillance of multidrug-resistant tuberculosis (MDR-TB) proved feasible and useful. The integration process improved overall data quality and data validation capacity, and integrated data are a useful addition to routine cohort and treatment outcome data. Besides their importance for individual patient care, they provide trends on the association of MDR-TB and HIV in the routine programme setting. They also form a useful epidemiological basis for more specific studies, such as on nosocomial outbreaks. Whether the system itself is sensitive enough to monitor possible outbreaks needs further investigation.

Development of two-channel prototype ITER vacuum ultraviolet spectrometer with back-illuminated charge-coupled device and microchannel plate detectors

A vacuum ultraviolet (VUV) spectrometer of a five-channel spectral system is designed for ITER main plasma impurity measurement. To develop and verify the system design, a two-channel prototype system is fabricated with No. 3 (14.4-31.8 nm) and No. 4 (29.0-60.0 nm) among the five channels. The optical system consists of a collimating mirror to collect the light from source to slit, two holographic diffraction gratings with toroidal geometry, and two different electronic detectors. For the test of the prototype system, a hollow cathode lamp is used as a light source. To find the appropriate detector for ITER VUV system, two kinds of detectors of the back-illuminated charge-coupled device and the microchannel plate electron multiplier are tested, and their performance has been investigated.

154. EFFECT OF KOREAN RED GINSENG EXTRACT IN STEROID-INDUCED POLYCYSTIC OVARY MURINE MODEL

Experimental induction of polycystic ovary (PCO) resembling some aspects of human PCO syndrome was produced using the long-acting compound estradiol valerate (EV). Our previous study on the role of Korean red ginseng total saponins in a steroid-induced PCO rat model demonstrated that electro-acupuncture modulates nerve growth factor (NGF) concentration in the ovaries. In fact, the involvement of a neurogenic component in the pathology of PCO-related ovarian dysfunction is preceded by an increase in sympathetic outflow to the ovaries. In the present study, we tested the hypothesis that Korean red ginseng extract (KRGE) administration modulates sympathetic nerve activity in rats with PCO. This was done by analysing NGF protein and NGF mRNA expression involved in the pathophysiological process underlying steroid-induced PCO. EV injection resulted in significantly higher ovarian NGF protein and NGF mRNA expression in PCO rats compared to control rats, and PCO ovaries were counteracted by KRGE administration with significantly lower expression of NGF protein and NGF mRNA compared to EV treated ovaries. These results indicate that EV modulates the neurotrophic state of the ovaries, which may be a component of the pathological process by which EV induces cyst formation and anovulation in rodents.

In-vessel design of ITER diagnostic neutron activation system

A neutron activation system utilizing an encapsulated metal sample technique will be implemented to evaluate total fusion power from ITER plasma. The positions of seven irradiation ends for each poloidal section are determined to optimize the measurements from asymmetric, elongated plasma with minimum uncertainty. To determine the exact location of the irradiation end, some physical and technical aspects for each location are investigated. Monte Carlo neutronic calculations are performed to assess the physical characteristics and optimize the design of each irradiation end.

Prevalence of capsular polysaccharide (CP) types of Staphylococcus aureus isolated from bovine mastitic milk and protection of S. aureus infection in mice with CP vaccine

To determine the prevalence of capsular polysaccharide (CP) types of Staphylococcus aureus isolated from bovine mastitic milk in Korea, the protective effect of the conjugates, composed of microencapsulated S. aureus clinical isolate type 8 CP bound to Pseudomonas aeruginosa exotoxin A (ETA) was evaluated in mice. Of 107 S. aureus isolates, serotype 5 and 8 accounted for only 26 or 24.2%. When serotype 336 antiserum was employed, fifty of the remaining 81 isolates were typed as 336, 26 reacted with two serotypes, and 5 were nontypeable. Mice challenged with the same strain used for immunization had fewer S. aureus cells in their kidneys than mice challenged with the heterologous strain. But the magnitudes of difference on bacterial clearance were similar in both groups, indicating that the significance of this result remains to be determined. Mice immunized with the conjugate elicited an antibody response 3 days post injection, which persisted for 13 days of the observation period after second injection in some mice. The mice immunized with the CP8-ETA conjugates developed antibodies significantly higher than those immunized with CP-Freund's adjuvant or PBS. In in vivo bacterial challenge experiment, the survival rate of mice immunized with CPS-ETA conjugate was significantly higher than that of mice immunized with PBS. It was suggested that CP8-ETA vaccine had a potential to protect mice against experimental S. aureus bacteremia.

Monitoring Piscirickettsia salmonis by denaturant gel electrophoresis and competitive PCR

Reported strains of Piscirickettsia salmonis, a pathogen of salmonid fishes, were analyzed by amplifying part of the internal transcribed spacer (ITS) of the ribosomal RNA (rRNA) operon followed by denaturing gradient gel electrophoresis (DGGE) of the amplicons. All amplified fragments differing in sequence were distinguished by migration during DGGE. A simpler format, constant denaturant gel electrophoresis (CDGE), allowed the same diagnostic distinctions among strains. Sampling during 1997 and 1998 of salmonids from 5 different sites on and near Chiloé Island in southern Chile displaying piscirickettsiosis revealed only P. salmonis resembling LF-89, the type strain first isolated in 1989. These observations are encouraging for control strategies, which might otherwise be compromised by unpredictable shifts of P. salmonis types in salmon farms. A competitive PCR assay offered insight about the power of PCR for quantification and about specific tissue invasiveness by this intracellular pathogen. This approach revealed that the PCR could amplify approximately 1 to 10 P. salmonis genome equivalents against a background of > 99.9% salmonid DNA. It also raised the possibility that the salmonid brain is an important site for P. salmonis survival, with its bacterial load in 1 individual having been about 100 times the loads observed in liver and kidney. Pathogen detection by competitive PCR in a surface seawater sample from a netpen in use indicated a density of about 3000 to 4000 P. salmonis cells (or their DNA remnants) 1(-1). Such quantitative estimates should aid decisions about disease prevention and management as, for example, choice of netpen sites following fallow periods and certification of ova, which are known conduits of infection.

Reduction aortoplasty for moderately sized ascending aortic aneurysms

Enlargement of the ascending aorta may coexist with concomitant valvular, coronary, or other cardiac diseases. If dilation is moderate (i.e., <6 cm diameter) and another cardiac procedure is being performed, we have reduced the diameter of the ascending aorta with an S-shaped incision and excision of the curves of the "S" as a modified Z-plasty. We have performed the procedure in 23 patients with concomitant procedures including aortic valve replacement in 21 (1 as a pulmonary autograft), coronary bypass in 1, and resection of subaortic stenosis in 1. There were 15 males and 8 females with a mean age of 53 years (range 8-67 years). The mean maximal preoperative diameter on transesophageal echocardiography was 5.0+/-0.7 cm (range 3.2-6.6 cm). The mean intraoperative postreduction diameter was 3.1+/-0.6 cm (range 2.1-4.1) (p<0.01). All patients tolerated their procedures well. Sixteen patients were studied by transthoracic echocardiography postoperatively. These patients had a mean intraoperative postreduction diameter of 2.9+/-0.65 cm that increased to 3.1+/-0.45 cm (p = NS) after a mean follow-up of 9.9+/-12.6 months. Of these, seven patients were studied >1 year postoperatively. Their mean intraoperative postreduction diameter of 2.9+/-0.5 cm increased to 3.1+/-0.35 cm (p = NS) after a mean follow-up of 22.1+/-9.2 months. No known recurrences of the aneurysms have occurred. We feel this technique is valid in patients with moderate aortic dilation undergoing concomitant cardiac procedures and in whom more aggressive aortic interventions are not warranted.

Cardiac assessment prior to vascular surgery: is dipyridamole-sestamibi necessary?

Dipyridamole-sestamibi (PMIBI) is recommended prior to vascular surgery in patients with > or = 1 Eagle criteria (Q waves, history of ventricular ectopy, diabetes, advanced age, and/or angina). To review our cardiac morbidity and mortality and the need for preoperative PMIBI, we reviewed 109 consecutive patients with a mean age of 59 years who underwent 145 elective major vascular procedures over a 1-year period. Seventy patients (with a mean of 0.8 Eagle criteria) underwent 92 vascular procedures without preoperative PMIBI and without coronary revascularization. Thirty-one patients (with a mean of 1.1 Eagle criteria) underwent 39 procedures without coronary revascularization following PMIBI, which showed reversible ischemia in seven and a fixed defect in 10; findings were normal in 14. Preoperative coronary bypass or angioplasty was limited to eight patients (14 procedures, mean of 1.6 Eagle criteria) who had unstable angina with (2 patients) or without (6 patients) acute myocardial infarction. There were four perioperative myocardial infarctions (2.8%), seven cardiac events overall (4.8%), and one cardiac death (0.7%). Three (43%) of the seven cardiac events occurred in patients with a normal scan or fixed defect on PMIBI imaging. In the absence of unstable angina, PMIBI had a sensitivity of only 25% and a specificity of 80% for cardiac events. We conclude that among patients without severe cardiac symptoms (1) PMIBI has a very limited ability to identify patients at risk for cardiac complications, and (2) preoperative PMIBI is neither necessary nor cost-effective.

Segmenting the senior health care market

This paper addresses the issue of health market segment comparisons for the senior population. The analysis demonstrates how initial self-assessed health comparisons among three racial/ethnic categories can be adjusted to reflect compositional (age and income) differences among the three groups. The adjustments provide additional insight into the nature of these segments.

Absence of transitory [Ca2+]i flux during early in vitro metacyclogenesis of Trypanosoma cruzi

The phorbol ester TPA (phorbol 12-myristate 13-acetate) substitutes for CO2 as an agonist for transforming Trypanosoma cruzi epimastigotes to the metacyclic trypomastigote stage in a starvation medium consisting of phosphate buffered saline + 10 mM proline, 10 mM sodium acetate and 0.035% NaHCO3. Since TPA is thought to stimulate protein kinase C by mimicking the activity of the secondary messenger diacylglycerol, the above result suggested that T. cruzi metacyclogenesis could be activated by a Ca(2+)-dependent protein kinase C signal induction pathway. Accordingly, cytosolic calcium flux ([Ca2+]i) in epimastigotes, activated with 5% CO2 or TPA (10(-7) M), was measured with the Ca2+ molecular probe, fluo-3AM. In addition, [Ca2+]i was measured in cells incubated with putative metacyclogenic agonists (e.g. proline, glutamate, bioamines, ionophores and catecholamines). None of the compounds studies, except for EGTA, affected cytosolic Ca2+ levels. Control assays with 11 microM thapsigargin, which mobilizes noncytoplasmic Ca2+ stores by inhibiting endoplasmic reticulum Ca(2+)-ATPase, validated our fluorometric assay procedure. Although thapsigargin significantly increases cytoplasmic Ca2+ fluorescence, it has no effect on transformation. The protein kinase C inhibitors staurosporine, H-7 and HA 1004 were tested for their effect on T. cruzi metacyclogenesis. Low concentrations of staurosporine and HA 1004 significantly elevated Peru strain transformation while H-7 had no effect on Peru strain metacyclogenesis. Inhibitor H-7 did significantly depress CL transformation. The results indicate that induction of T. cruzi metacyclic trypomastigote formation by CO2 and TPA is not accompanied by changes in cytosolic Ca2+ and do not provide supporting evidence for participation of a protein kinase C-mediated phosphoinositide cascade in metacyclogenesis.

Spontaneous rupture of pyelocaliceal diverticulum

One rare case of spontaneous rupture of pyelocaliceal diverticulum is reported in a 31-year-old Japanese man presented with a severe left flank pain. Intravenous pyelography and computerized tomography demonstrated extravasation of contrast medium from his diverticulum which contained numerous calculi. As a possible cause of spontaneous rupture of pyelocaliceal diverticulum in this case, we suggest that the paper-thin parenchyma covering the diverticulum was not strong enough to tolerate the minimum elevation of intrapelvic pressure due to the obstruction of delivered stones.