Probing the energetic particle environment near the Sun.

NASA's Parker Solar Probe mission1 recently plunged through the inner heliosphere of the Sun to its perihelia, about 24 million kilometres from the Sun. Previous studies farther from the Sun (performed mostly at a distance of 1 astronomical unit) indicate that solar energetic particles are accelerated from a few kiloelectronvolts up to near-relativistic energies via at least two processes: 'impulsive' events, which are usually associated with magnetic reconnection in solar flares and are typically enriched in electrons, helium-3 and heavier ions2, and 'gradual' events3,4, which are typically associated with large coronal-mass-ejection-driven shocks and compressions moving through the corona and inner solar wind and are the dominant source of protons with energies between 1 and 10 megaelectronvolts. However, some events show aspects of both processes and the electron-proton ratio is not bimodally distributed, as would be expected if there were only two possible processes5. These processes have been very difficult to resolve from prior observations, owing to the various transport effects that affect the energetic particle population en route to more distant spacecraft6. Here we report observations of the near-Sun energetic particle radiation environment over the first two orbits of the probe. We find a variety of energetic particle events accelerated both locally and remotely including by corotating interaction regions, impulsive events driven by acceleration near the Sun, and an event related to a coronal mass ejection. We provide direct observations of the energetic particle radiation environment in the region just above the corona of the Sun and directly explore the physics of particle acceleration and transport.

[Breast cancer screening: current status]. / Cribado de cáncer de mama. Estado actual.

The currently available scientific evidence attests that mammographic screening and quality treatment have been able to reduce mortality attributable to breast cancer. Although screening is not without risks, population-based screening has clear advantages over opportunistic detection. Following the Council of the European Union's "Recommendations on cancer screening", all the regional Autonomous Communities in Spain have screening programs that, in general, follow the same guidelines. The "European guidelines for quality assurance in breast cancer screening and diagnosis" serve as a reference that provides an overview of all aspects of screening. To achieve the foreseen objectives for the reduction of the morbidity and mortality attributable to breast cancer, screening programs must fulfill the established quality criteria and guarantee that patients have access to the best treatment options.

New cryogenic environment for beamline ID22 at the European Synchrotron Radiation Facility.

A compact minicryostat has been well adapted on the hard x-ray microprobe ID22 of the European Synchrotron Radiation Facility. For variable low-temperature investigations, its special technical design provides precise scanning microscopy and allows easy access for multiple detection modes. Based on x-ray excited optical luminescence technique on the micrometer scale, details of the equipment, its temperature calibration, and typical results are described. Data collections from InAs quantum heterostructures support the excellent thermal performance of the novel cryogenic device.

Complex three-dimensional self-assembly in proxies for atmospheric aerosols.

Aerosols are significant to the Earth's climate, with nearly all atmospheric aerosols containing organic compounds that often contain both hydrophilic and hydrophobic parts. However, the nature of how these compounds are arranged within an aerosol droplet remains unknown. Here we demonstrate that fatty acids in proxies for atmospheric aerosols self-assemble into highly ordered three-dimensional nanostructures that may have implications for environmentally important processes. Acoustically trapped droplets of oleic acid/sodium oleate mixtures in sodium chloride solution are analysed by simultaneous synchrotron small-angle X-ray scattering and Raman spectroscopy in a controlled gas-phase environment. We demonstrate that the droplets contained crystal-like lyotropic phases including hexagonal and cubic close-packed arrangements of spherical and cylindrical micelles, and stacks of bilayers, whose structures responded to atmospherically relevant humidity changes and chemical reactions. Further experiments show that self-assembly reduces the rate of the reaction of the fatty acid with ozone, and that lyotropic-phase formation also occurs in more complex mixtures more closely resembling compositions of atmospheric aerosols. We suggest that lyotropic-phase formation likely occurs in the atmosphere, with potential implications for radiative forcing, residence times and other aerosol characteristics.

Blood recirculation in malfunctioning catheters for haemodialysis.

Venous catheters are increasingly used for chronic haemodialysis, with dual lumen catheters being the most commonly used as blood recirculation (REC%) is relatively low. The aim of this study was therefore to evaluate blood recirculation in dual lumen catheters, both well-functioning and malfunctioning, with reversed lumens. In our study, blood recirculation in well-functioning catheters with standard lumens is similar to that found in previous studies. However, when lumens are reversed, blood recirculation increases significantly (6.7 +/- 4 vs 19 +/- 11%, p < 0.001). REC% in malfunctioning catheters (10.8 +/- 2%) was higher than normal function (p < 0.05) but lower than reversed flow in normal catheters (p < 0.01). Therefore, inadvertent reversal of lumens in a well-functioning catheter increases REC% in a significant manner, thus worsening haemodialysis efficiency. We conclude that, in inflow failure catheters, lumens can be reversed because REC% is acceptable. However, inadvertent reversal of lumens in a well-functioning catheter increases REC% to a level which may compromise the adequacy of haemodialysis.

[Early detection of breast cancer in Navarra. Diagnostic approach in women sent to a referral hospital]. / Detección precoz del cáncer de mama en Navarra. Conducta diagnóstica en las mujeres enviadas a un hospital de referencia.

BACKGROUND: Breast cancer screening programs represent an important increase in the number of patients to be evaluated and a higher proportion of subclinical lesions detected in reference hospitals. The authors' experience related to an early detection program initiated in Navarra, Spain (PDPCM) is herein presented. METHODS: The diagnoses made in 319 women referred from the PDPCM to the authors' hospital for mammographic suspicion of malignancy were reviewed. Directed surgical biopsy was carried out in 89 women (27.9%) without previous cytologic study. Fine needle aspiration punction and cytology (FNAP-cytology) were performed as the first diagnostic test in 216 lesions (67.7%) 53 of which were palpable and 163 nonpalpable. Aggressive techniques were not indicated in 14 cases (4.4%). RESULTS: A total of 136 carcinomas (42.6%) were diagnosed and benign lesions were find at biopsy in 112 (35.1%) women. The fifty-seven lesions (17.9%) which did not show malignancy on FNAP-cytology were not biopsied given the insufficient degree of suspicion. Only one false negative has appeared in this group from 27 to 48 months after the first consultation. The global diagnostic reliability was of 99.68%. CONCLUSIONS: Directed surgical biopsy is the most reliable technique for the diagnosis of nonpalpable breast lesions in early stages and is always necessary when there is medium or high radiologic suspicion of malignancy. Fine needle aspiration puncture is a very useful technique to confirm malignancy and to avoid unnecessary biopsies in low suspicion lesions.

[Biochemical evaluation of renal lesions produced by electrohydraulic shock waves]. / Evaluation biochimique des lésions rénales produites par les ondes de choc électrohydrauliques.

The authors present a biochemical study of the renal lesions produced during extracorporeal electrohydraulic shock wave lithotripsy (ESWL). The sequential variation (before and after ESWL) of various biochemical parameters of the blood and 24-hour urine was analysed in 50 patients. A significant increase of urinary N-Acetyl-Glucosaminidase (NAG), urinary NAG/urinary creatinine quotient, proteinuria, serum creatinine and potassium was detected during the 24 hours following ESWL. A significant fall in creatinine clearance, urinary osmolarity and uric acid clearance was also detected. A positive correlation was observed between these alterations, the number of shocks and the kilovoltage used. On the 7th and 15th days, no significant difference was observed compared to the baseline values before ESWL. This can be explained by the fact that the lesions caused by shock waves are already in the repair phase.

[Leptin in the endocrinology of obesity]. / Leptina en la endocrinología de la obesidad.

The article summarizes the endocrinology axis in relation to leptin in the obesity. There is a glucocorticoid hypothesis in the obesity origin. Human plasma leptin levels are elevated in Cushing's syndrome and there is a robust leptin secretory responses to dexamethasone. Obesity impacts on reproductive function in man and women. Leptin levels are higher in women than in men and a critical blood leptin level is necessary to trigger reproductive ability in women. The relationship between body mass index and circulating leptin varies during the course of spontaneous cycles in women, the best correlation occurring during the luteal phase when progesterone and leptin concentrations are highest. Obesity is associated with a decrease in growth hormone (GH) and reversible with weight loss. The influence of body composition on GH secretion in the obesity may be mediated through leptin, acting as a peripheral signal from adipose tissue. Thyroid dysfunction appear not associated with alterations in serum leptin levels. There is a significant relationship between insulin and leptin, but it is not immediate, since type 2 diabetics show similar leptin levels to those of nondiabetic humans of the same body mass index.

[Laparoscopic findings in patients with pelvic pain, dysmenorrhea and sterility]. / Hallazgos laparoscópicos en pacientes con dolor pélvico, dismenorrea y esterilidad.

Endometriosis is a frequent gynecologic disease and is associated with dysmenorrhea, pelvic pain and infertility. We evaluated 71 patients who had any of these entities and were treated with laparoscopic procedures. We found a higher frequency of endometriosis in these groups in comparation with the reports of the literature but, there was no direct relation between the severity of endometriosis and the three groups (Revised Classification of the American Fertility Society). The organic pathology was the principal factor associated with the pelvic pain in most cases. Finally, we established the utility of laparoscopy in the diagnosis stading and treatment of endometriosis.

[Diagnostic and therapeutic usefulness of laparoscopic surgery in acute abdomen of gynecologic origin]. / "Utilidad diagnóstica y terapéutica de la cirugía laparoscópica en el abdomen agudo de origen ginecológico".

The objective was to determine the usefulness of laparoscopy for treatment of gynecological emergencies. In this work were studied 78 cases of patients which were treated in the Emergency Room of ABC Hospital, with symptomatology associated to reproductive organs. The age of patients was 27.7 +/- 6.3 years. The more frequent diagnosis before surgery were ectopic pregnancy and ovarian cysts, the remainder patients were operated to determine pain etiology. Ectopic pregnancy antecedent was determinant to have same problem (X2, p < 0.05), other determinative factors were infertility and pelvic inflammatory disease. Abdominal pathology was detected in 97.4% of patients; 98.6% with gynecological pathology. The predictive positive value of preoperative diagnosis was 83.3% and 91.3% for ectopic pregnancy and ovarian cysts, respectively. In 25.6% of the cases endoscopy turned in laparotomy; massive hemoperitoneum in tubal rupture in cases of ectopic pregnancy was the most frequent indication of this conduct. As conclusion, laparoscopy is useful in most of cases of gynecological emergencies. Fast detection or abdominal pathology, in special ectopic pregnancy can be to lower conversion of laparoscopy to open surgery.

[Familial pituitary tumor with somatotropic compromise]. / Tumor hipofisario familiar de compromiso somatomamotrópico.

Pituitary adenoma, familiar type, with apparent affection over the involved somatomammotropin of secretion of growth hormone and prolactin, with dominant autosomic transmission, is described for the first time. It was seen that a couple of members without demonstrable tumour, showed clinical data (phenotype) of acromegaly. On investigation of histocompatibility antigens it was observed that the patients with tumour and other symptomatic ones, but without tumour, shared the same haplotypes, and so is very possible that investigation of HLA antigens in patients with pituitary tumour, contributes to better identify its nature and frequency.

[Experimental cryptorchism in the Wistar rat]. / Criptorquidia experimental en rata Wistar.

Experimental cryptorchidism was performed on Wistar rats, fixing the left testicle into the peritoneum for a month. Animals under study (84) were divided into four groups: control, control treated with hCG, cryptorchid and cryptorchid treated with hCG. Cryptorchid testes were biopsied at three, five and eight months and all were excised at 12 months. Cellular counts on spermatogonia, young and late spermatocytes, Sertoli cells and vacuolized Sertoli cells, together with the slough tubular and germinal cell percentage and the tubular diameter, let us affirm by means statistical studies (ANOVA, Chi square) that a testes recovering is already shown at the age of five months, although this recovering still differs from the one shown in the control groups.

Thermal and structural study of the crystal phases and mesophases in the lithium and thallium(i) propanoates and pentanoates binary systems: formation of mixed salts and stabilization of the ionic liquid crystal phase.

The temperature and enthalpy vs composition phase diagrams of the binary systems [xC(2)H(5)CO(2)Li + (1 - x)C(2)H(5)CO(2)Tl], and [x(n-C(4)H(9)CO(2)Li) + (1 - x)n-C(4)H(9)CO(2)Tl], where x is the mole fraction, were determined by DSC. Both binary systems display the formation of one 2:1 mixed salt each (at x = 0.667) that appear as a peritectic (incongruent melting) at T(fus) = 512.0 K, and T(fus) = 461.1 K, with Delta(fus)H(m) = 13.76 and 8.08 kJ.mol(-1) for Li-Tl (I) propanoates, and n-pentanoate mixed salts, respectively. The thermotropic liquid crystal of the thallium(I) n-pentanoate transforms into a more stable liquid-crystal phase, which appears in the phase diagram between 380 and 488 K and for x = 0 up to x = 0.56. The crystal structure of thallium(I) propanoate and of the two mixed salts were obtained via X-ray synchrotron radiation diffraction measurements. These compounds present a bilayered structure similar to the two pure lithium salts previously found by our group.

[Evolution of epilepsy in successive pregnancies]. / Evolución de la epilepsia en gestaciones sucesivas.

INTRODUCTION: Hormonal and metabolic factors related to pregnancy itself are considered to increase the likelihood of seizure recurrence. If so, we should expect a similar evolution of epilepsy in a subsequent pregnancy. We investigated differences in evolution of non-gestational epilepsy in each pregnancy of women suffering from epilepsy. METHODS: A prospective study was conducted in order to compare seizure frequency in two successive pregnancies of more than 36 weeks duration in 12 patients. Improvement/worsening is defined as a change of +/- 50 % in the number of seizures regarding that which occurred within the previous eleven months. RESULTS: Twelve epileptic women were studied during two subsequent pregnancies. Eight of them took the same antiepileptic treatment for both pregnancies and one took no antiepileptic drug. Three worsened in the first pregnancy and two in the second. Seven patients had the same seizure frequency during both pregnancies. The total plasma antiepileptic concentrations tended to decline with the same proportion in both pregnancies if the dose remained unchanged. We observed no differences in mean hormone plasma concentrations for each quarter, within subsequent pregnancies. CONCLUSION: Except for one case with drug-resistant epilepsy, we found that the reason for the discrepancy in the frequency of the seizure between two successive pregnancies in the same patient was a sharp or rapid change in antiepileptic drug dose or non-compliance. In well controlled epileptic women a consistent evolution of epilepsy should be expected in a subsequent pregnancy, if adequate treatment is maintained.

New measurement of the cosmic-ray positron fraction from 5 to 15 GeV.

We present a new measurement of the cosmic-ray positron fraction at energies between 5 and 15 GeV with the balloon-borne HEAT-pbar instrument in the spring of 2000. The data presented here are compatible with our previous measurements, obtained with a different instrument. The combined data from the three HEAT flights indicate a small positron flux of nonstandard origin above 5 GeV. We compare the new measurement with earlier data obtained with the HEAT-e(+/-) instrument, during the opposite epoch of the solar cycle, and conclude that our measurements do not support predictions of charge sign dependent solar modulation of the positron abundance at 5 GeV.

[Molecular forms of PSA and differentiating between benign hypertrophy,carcinoma, and disseminated prostatic carcinoma. Correlation between two determination technics]. / Formas moleculares de PSA en la discriminación entre hipertrofia benigna, carcinoma y carcinoma diseminado de próstata. Correlación entre dos diferentes técnicas de determinación.

OBJECTIVE: To determine the correlation between two methods of measurement of total PSA (PSA-T) and free PSA (PSA-F) and the utility of the PSA-F/PSA-T ratio in patients with PSA-T between 4 and 10 ng/ml suspected as having prostate cancer. METHODS: Determinations of both PSA-T and PSA-F were performed using two different techniques in 91 patients suspected as having prostate cancer. Diagnosis was made on the findings of biopsy and the complementary tests. RESULTS: The following correlation was found for the two techniques: R = 0.99 and p < 0.05 for PSA-T, and R = 0.85 and p < 0.05 for PSA-F. For PSA-T values of 4-10 ng/ml and PSA-F greater than 25%, we found two patients with prostate cancer. For a PSA-F/PSA-T ratio less than 9%, all cases had prostate cancer. Three cases with bone metastasis had PSA-T values less than 10 ng/ml. CONCLUSIONS: A PSA-F/PSA-T ratio greater than 25% does not exclude malignancy in patients with a total PSA of 4-10 ng/ml; values less than 9% correspond to prostate cancer. Bone metastasis was found with both methods in patients with total PSA values less than 10 ng/ml.

Measurement of the cosmic-ray antiproton-to-proton abundance ratio between 4 and 50 GeV.

We present a new measurement of the antiproton-to-proton abundance ratio, pbar/p, in the cosmic radiation. The HEAT-pbar instrument, a balloon borne magnet spectrometer with precise rigidity and multiple energy loss measurement capability, was flown successfully in Spring 2000, at an average atmospheric depth of 7.2 g/cm(2). A total of 71 antiprotons were identified above the vertical geomagnetic cutoff rigidity of 4.2 GV. The highest measured proton energy was 81 GeV. We find that the pbar/p abundance ratio agrees with that expected from a purely secondary origin of antiprotons produced by primary protons with a standard soft energy spectrum.