Shape Changes in the Mirror Nuclei

We studied the proton-rich T_{z}=-1 nucleus ^{70}Kr through inelastic scattering at intermediate energies in order to extract the reduced transition probability, B(E2;0^{+}→2^{+}). Comparison with the other members of the A=70 isospin triplet, ^{70}Br and ^{70}Se, studied in the same experiment, shows a 3σ deviation from the expected linearity of the electromagnetic matrix elements as a function of T_{z}. At present, no established nuclear structure theory can describe this observed deviation quantitatively. This is the first violation of isospin symmetry at this level observed in the transition matrix elements. A heuristic approach may explain the anomaly by a shape change between the mirror nuclei ^{70}Kr and ^{70}Se contrary to the model predictions.

Evidence for Coexisting Shapes through Lifetime Measurements in

The lifetimes of the first excited 2^{+}, 4^{+}, and 6^{+} states in ^{98}Zr were measured with the recoil-distance Doppler shift method in an experiment performed at GANIL. Excited states in ^{98}Zr were populated using the fission reaction between a 6.2 MeV/u ^{238}U beam and a ^{9}Be target. The γ rays were detected with the EXOGAM array in correlation with the fission fragments identified by mass and atomic number in the VAMOS++ spectrometer. Our result shows a very small B(E2;2_{1}^{+}→0_{1}^{+}) value in ^{98}Zr, thereby confirming the very sudden onset of collectivity at N=60. The experimental results are compared to large-scale Monte Carlo shell model and beyond-mean-field calculations. The present results indicate the coexistence of two additional deformed shapes in this nucleus along with the spherical ground state.

Shape Evolution in Neutron-Rich Krypton Isotopes Beyond N=60: First Spectroscopy of

We report on the first γ-ray spectroscopy of low-lying states in neutron-rich ^{98,100}Kr isotopes obtained from ^{99,101}Rb(p,2p) reactions at ∼220 MeV/nucleon. A reduction of the 2_{1}^{+} state energies beyond N=60 demonstrates a significant increase of deformation, shifted in neutron number compared to the sharper transition observed in strontium and zirconium isotopes. State-of-the-art beyond-mean-field calculations using the Gogny D1S interaction predict level energies in good agreement with experimental results. The identification of a low-lying (0_{2}^{+}, 2_{2}^{+}) state in ^{98}Kr provides the first experimental evidence of a competing configuration at low energy in neutron-rich krypton isotopes consistent with the oblate-prolate shape coexistence picture suggested by theory.

Are There Signatures of Harmonic Oscillator Shells Far from Stability? First Spectroscopy of

The first measurement of the low-lying states of the neutron-rich ^{110}Zr and ^{112}Mo was performed via in-beam γ-ray spectroscopy after one proton removal on hydrogen at ∼200 MeV/nucleon. The 2_{1}^{+} excitation energies were found at 185(11) keV in ^{110}Zr, and 235(7) keV in ^{112}Mo, while the R_{42}=E(4_{1}^{+})/E(2_{1}^{+}) ratios are 3.1(2), close to the rigid rotor value, and 2.7(1), respectively. These results are compared to modern energy density functional based configuration mixing models using Gogny and Skyrme effective interactions. We conclude that first levels of ^{110}Zr exhibit a rotational behavior, in agreement with previous observations of lighter zirconium isotopes as well as with the most advanced Monte Carlo shell model predictions. The data, therefore, do not support a harmonic oscillator shell stabilization scenario at Z=40 and N=70. The present data also invalidate predictions for a tetrahedral ground state symmetry in ^{110}Zr.

Erratum: Spectroscopic Quadrupole Moments in

This corrects the article DOI: 10.1103/PhysRevLett.116.022701.

Spectroscopic Quadrupole Moments in {96,98}Sr: Evidence for Shape Coexistence in Neutron-Rich Strontium Isotopes at N=60.

Neutron-rich {96,98}Sr isotopes have been investigated by safe Coulomb excitation of radioactive beams at the REX-ISOLDE facility. Reduced transition probabilities and spectroscopic quadrupole moments have been extracted from the differential Coulomb excitation cross sections. These results allow, for the first time, the drawing of definite conclusions about the shape coexistence of highly deformed prolate and spherical configurations. In particular, a very small mixing between the coexisting states is observed, contrary to other mass regions where strong mixing is present. Experimental results have been compared to beyond-mean-field calculations using the Gogny D1S interaction in a five-dimensional collective Hamiltonian formalism, which reproduce the shape change at N=60.

A mean body temperature of 37°C for incubated preterm infants is associated with lower energy costs in the first 11 days of life.

AIM: This randomised trial compared the energy costs of providing incubated preterm infants born before 32 weeks of gestation with homeothermia using either air temperature control (ATC) or skin servocontrol (SSC). METHODS: We studied 38 incubated preterm infants for the first 11 days of life, calculating the frequency of hypothermia (<36.0°C), hyperthermia (>37.5°C) and thermal challenge, together with energy costs, based on a change in incubator air temperature of 2°C above or below thermoneutrality. RESULTS: The daily mean incubator air temperature was higher in ATC than SSC (p < 0.05) for the first 6 days, and the mean body temperature was higher in ATC (37.0 ± 0.03°C) than SSC (36.8 ± 0.02; p < 0.01) over the whole study period. The frequency of moderate hyperthermia was higher in ATC (p < 0.001), whereas warm and cold thermal challenges were higher in SSC (p < 0.001). The two groups did not differ in terms of energy costs. The time to recover birthweight was shorter in ATC (p < 0.05). CONCLUSION: In incubators using ATC, a body temperature of 37°C was associated with lower energy costs and greater weight gain at 11 days of life for preterm infants. Future studies should test SSC shielded abdominal skin temperature set to 37°C.

Vitrectomy in uveitis patients.

PURPOSE: To evaluate the causes and success rates of pars plana vitrectomy (PPV) in uveitis patients. METHODS: Retrospective study of the charts of 26 uveitis patients (28 eyes) who underwent PPV between the years 2008 and 2011. We examined surgical indications and success rates, based on visual outcomes, complications and diagnosis in case of vitreous biopsy. RESULTS: (1) Therapeutic PPV (TV) was performed in 36% of the eyes, (2) TV combined with epiretinal membrane (ERM) peeling in 21% and (3) diagnostic PPV (DiV) was performed in 64% of the eyes. Eight eyes (28,6%) underwent a combined cataract and vitreous surgery. Visual acuity (VA) improved in 16 eyes (57%), with a mean improvement of -0,9 log of the minimum angle of resolution (logMAR), although the effect was transient in 7% of the cases. VA remained stable in 11 eyes (39%) and decreased in 1 (4%). Post-operative complications were cystic macular oedema (CMO) in 3 eyes (11%), cataract in 5 eyes (18%) and retinal detachment in 2 eyes (7%). Diagnostic tests were performed in 18 eyes with a success rate of 55%. CONCLUSIONS: In our series of patients with uveitis, a good andstable improvement of VA was found when PPV was performed with ERM peeling while the effect on VA was more transient in the other cases. A good success rate of diagnosis was also found in DiV. However, considering the possible severe complications, diagnostic vitrectomy should be limited to selected cases.

Two-particle separation energy trends in the superdeformed well.

A measurement of the energy and spin of superdeformed states in 190Hg, obtained through the observation of transitions directly linking superdeformed and normal states, expands the number of isotopes in which binding energies at superdeformation are known. Comparison with neighboring nuclei shows that two-proton separation energies are higher in the superdeformed state than in the normal state, despite the lower Coulomb barrier and lower total binding energy. This unexpected result provides a critical test for nuclear models.

[Heat exchanges and thermoregulation in the neonate]. / Echanges thermiques et thermorégulation chez le nouveau-né.

The newborn's energy expenditure is used in order of priority for: (i) basic metabolism; (ii) body temperature regulation and (iii) body growth. Thermal regulation is an important part of energy expenditure, especially for low birth-weight infants or preterm newborns. The heat exchanges with the environment are greater in the infant than in the adult, explaining the increased risk of body hypo- or hyperthermia. The newborn infant is a homeotherm, but over a long period of time, he cannot maintain the thermal processes. Further developments are expected to improve the infant's thermal environment, with assessment of the various heat exchange mechanisms by conduction, convection, radiation and evaporation. The quantification of the respective parts of these exchanges would improve nursing care through clinical procedures or equipment used to ensure the control of the optimal thermohygrometric conditions in incubators, especially when the likelihood of excessive body cooling is high. The present review focuses on the various body heat exchange mechanisms, the thermoregulation processes of the newborn, and their implications in clinical usage and limitations in the neonatal intensive care unit.

Different presentations of ophthalmic aspergillosis.

PURPOSE: Aspergillus species is found worldwide and does not normally cause disease. However, when the immune system is compromised, it can invade many organs and be responsible for severe disease. The authors present cases with both classical and atypical features of ophthalmic aspergillosis. METHODS: Case series of three patients. RESULTS: All patients were female and had a long history of methylprednisolone use. The first two presented with endogenous endophthalmitis. One case was unilateral with a classical presentation of endophthalmitis. The other presented with a very severe bilateral acute retinal necrosis like syndrome. General work-up revealed disseminated disease in both cases. The diagnosis was made by serum immunologic testing in one case and after direct examination and culture from vitrectomy in the other. Despite intense antimycotic therapy, both patients died. The third patient presented with a unilateral progressive painful orbital apex syndrome. An orbital lesion was demonstrated by computed tomography scan and was unresponsive to methylprednisolone. Diagnosis of sino-orbital syndrome was made on biopsy. The lesion responded poorly to different antimycotic therapies, invaded the chiasma, and the patient lost all visual acuity. CONCLUSIONS: This case series illustrates that ophthalmic aspergillosis can present acutely with a devastating intraocular inflammation or more indolently in the setting of sino-orbital aspergillosis. Both forms have a poor visual prognosis and the systemic form is frequently associated with a fatal outcome.

[Toxicity of intravitreal injections of antibiotics and antivirals]. / La toxicité des injections intravitréennes d'antibiotiques et antiviraux.

Intravitreal injections of antivirals, antifungals and antibiotics are very efficacious in the management of intraocular infections, which is not the case with per os, intravenous or peribulbar administration. However, these drugs have some toxic potential, more pronounced if used in intraocular condition. Being too toxic, aminoglycosides have been replaced by Ceftazidime and Vancomycine in the management of bacterial endophthalmitis. Efficacy of these drugs for prophylactic use is not demonstrated and their toxic potential remains to be kept in mind.

Histologic study of coronary, radial, ulnar, epigastric and internal thoracic arteries: application to coronary artery bypass grafts.

The biometry and the histology of coronary, radial, ulnar, epigastric and internal thoracic arteries were studied in order to investigate the cause of their occlusions in coronary bypass grafts and to improve the results of these bypass grafts. These various arteries were removed from 40 anatomical specimens (27 males and 13 females). We found a correlation between the internal calibers of the ulnar and coronary arteries in males. Intimal changes and the presence of atheromatous plaque were observed in coronary, radial and ulnar arteries, but never in the internal thoracic artery. Like coronary arteries and their branches, radial, ulnar and epigastric arteries are muscular arteries and ageing results in thickening of the intima, which becomes fibrotic with migration of myocytes from the media and duplication of the internal elastic lamina. The media becomes fibrous, hypertrophic or atrophic. In contrast, the internal thoracic artery is an elastic artery, like the aorta. Ageing is characterized by loss, over a variable extent, of one or several elastic laminae of the media and more marked intimal thickening. Although anatomically, the caliber of radial, ulnar, and epigastric arteries remains adapted to that of coronary arteries, the long-term patency of radial, ulnar and epigastric arteries used as grafts is related to their histological characteristics.

[Thermal regulation during sleep]. / La régulation thermique au cours du sommeil.

Many studies point out that ambient temperatures outside the thermoneutral zone disturb sleep. Thermal responses depend on the phase of sleep and it appears that rapid eye movement (REM) sleep and thermoregulation are mutually exclusive in animals. In humans, there is evidence that this thermoregulatory disruption is less important since the thermal responses to heat or cold exposures are not abolished. Thermal responses persist during slow wave sleep (SWS). These differences suggest that there is a hierarchical control of body temperature regulation. The control includes different integrators at many levels of the nervous system with each level facilitated or inhibited by levels above and below. During SWS, body temperature is controlled by diencephalic structures whereas during REM sleep there is a suspension of hypothalamic thermoregulatory influences. The thermoregulatory differences may be accounted for by the neural organization and the autonomy of brain stem and spinal operative levels which differ between sleep phases and species. However, in the neonate, thermoregulation is not impaired during active sleep (AS) and Quiet Sleep (QS) considered, from behavioral and polygraphic measures, as immature forms of REM and SWS, respectively. From a thermoregulatory point of view, AS seems to be a well-protected sleep phase. As regards the thermal responses, these observations suggest that neonatal active sleep may be a precursor both of REM sleep and SWS in adults.

Peripheral chemoreceptor activity in sleeping neonates exposed to warm environments.

In neonates, it is often assumed that ventilatory control and heat stress interact. Thus the two factors have been implicated in various pathologies (apnoea, sudden infant death syndrome). However, little is known about the mechanisms of this interaction, and the influence of sleep is still debated. This study aimed at determining the influence of warm exposure on the decrease in ventilation during a hyperoxic test (HT), which is considered to be a measure of peripheral chemoreceptor activity. The test was performed in active (AS) and quiet sleep (QS) in 12 neonates exposed to thermoneutral or warm environments. The HT consisted of 30 s of inspired, 100% O(2). The ventilatory response was assessed in terms of a response time, defined as the time elapsing between HT onset and the first significant change in V(E). Our results show that, in both thermal conditions, the fall in V(E) was higher in AS than in QS. Warm exposure significantly enhanced the ventilatory response in AS (-27.5 +/- 8.7% vs. -38.3 +/- 8.8%, P < 0.01) but not in QS. A thermometabolic drive or inputs from thermoreceptors could be involved in the reinforcement of peripheral chemoreceptor activity in AS in warmer environments, which could contribute to an increasing risk of apnoea in neonates with altered chemoreceptor function. Since hypothalamic structures are involved in thermoregulatory, sleep processes and (probably) in respiratory control, it could well be the principal site where this interaction occurs.

Vitrectomy and silicone oil in the treatment of acute endophthalmitis. Preliminary results.

PURPOSE: To evaluate the role of pars plana vitrectomy (PPV) and silicone oil injection in the treatment strategy of severe endophthalmitis. PATIENTS AND METHODS: This study analyses a retrospective case series of 34 patients with signs and symptoms of severe endophthalmitis with visual acuity limited to light perception. All underwent PPV with intraocular injection of antibiotics (IOAB), together with topical and oral antibiotics. In 10 patients (group 1), this treatment alone was sufficient to control infection. In 10 other patients (group 2) with the same initial treatment, a new vitrectomy was needed: 8 because of retinal detachment, 2 because of persistent infection. In 2 patients (group 3), initially treated with PPV and IOAB, a second vitrectomy with IOAB and silicone oil tamponade was needed to stop infection. In 12 patients (group 4), with the worse prognosis related to the severity of infection and/or to associated retinal necrosis, PPV, IOAB and silicone oil tamponade were conducted at first surgery. Final anatomic status and visual acuity were assessed to compare the effectiveness of these different treatments. RESULTS: In 22 patients (group 1, 2 and 3) treated initially without silicone oil, 12 patients (55%) needed further surgery, either for persistent infection or retinal detachment. Twelve patients (group 4) treated at first with silicone oil had a rapid control of the infectious process and better anatomical results with this procedure only. Final visual acuity was also better in the silicone oil groups (group 3 and 4) than in the non silicone groups (group 1 and 2). CONCLUSION: These results suggest that silicone oil tamponade might be beneficial in the treatment strategy of severe endophthalmitis.

CXCR4 expression in vitreoretinal membranes.

BACKGROUND/AIM: Proliferative vitreoretinopathy (PVR) and macular pucker (MP) vitreoretinal membranes are caused by abnormal cell migration. By their role in chemotactism, chemokine receptors represent good candidates to sustain this process. The authors thus investigated the expression of one of them, CXCR4, in these pathologies. METHODS: Three PVR and four MP membranes were surgically removed and processed for immunochemical studies with antibodies for CXCR4, cytokeratins or smooth muscle actin. RESULTS: CXCR4 expression was found in all membranes. There was no relation between severity of PVR or MP and presence of CXCR4. In addition, there was no difference in CXCR4 expression between MP and PVR. CONCLUSION: CXCR4 is expressed in PVR and MP. Further experiments are needed to test if CXCR4 and other chemokine receptors are implicated in vitreoretinal membrane formation.

Measurement of functional residual capacity through the transient phase of He dilution in newborns.

Helium dilution maneuver is used to determine the functional residual capacity (FRC) 14 newborns ages 1-5 mo. The model equation describes the changing alveolar fractions of He and the ventilation promoted by a rebreathing procedure that does not exceed 40 s. The model does not involve the volume of the rebreathing bag usually needed when applying rebreathing technique and which is a source of error. The equation is discretized and solved for recorded data obtained with equipment adapted to newborns. Results show a strong relationship between FRC and the biometrical indexes, and confirm those found in the literature featuring that the measurement duration of FRC can be considerably shortened.