Comment on "Isochoric, isobaric, and ultrafast conductivities of aluminum, lithium, and carbon in the warm dense matter regime".

Dharma-wardana et al. [M. W. C. Dharma-wardana et al., Phys. Rev. E 96, 053206 (2017)2470-004510.1103/PhysRevE.96.053206] recently calculated dynamic electrical conductivities for warm dense matter as well as for nonequilibrium two-temperature states termed "ultrafast matter" (UFM) [M. W. C. Dharma-wardana, Phys. Rev. E 93, 063205 (2016)2470-004510.1103/PhysRevE.93.063205]. In this Comment we present two evident reasons why these UFM calculations are neither suited to calculate dynamic conductivities nor x-ray Thomson scattering spectra in isochorically heated warm dense aluminum. First, the ion-ion structure factor, a major input into the conductivity and scattering spectra calculations, deviates strongly from that of isochorically heated aluminum. Second, the dynamic conductivity does not show a non-Drude behavior which is an essential prerequisite for a correct description of the absorption behavior in aluminum. Additionally, we clarify misinterpretations by Dharma-wardana et al. concerning the conductivity measurements of Gathers [G. R. Gathers, Int. J. Thermophys. 4, 209 (1983)IJTHDY0195-928X10.1007/BF00502353].

Warm Dense Matter Demonstrating Non-Drude Conductivity from Observations of Nonlinear Plasmon Damping.

We present simulations using finite-temperature density-functional-theory molecular dynamics to calculate the dynamic electrical conductivity in warm dense aluminum. The comparison between exchange-correlation functionals in the Perdew-Burke-Enzerhof and Heyd-Scuseria-Enzerhof (HSE) approximation indicates evident differences in the density of states and the dc conductivity. The HSE calculations show excellent agreement with experimental Linac Coherent Light Source x-ray plasmon scattering spectra revealing plasmon damping below the widely used random phase approximation. These findings demonstrate non-Drude-like behavior of the dynamic conductivity that needs to be taken into account to determine the optical properties of warm dense matter.

[Persistent mullerian duct syndrome : Rare incidental finding during treatment of pediatric inguinal hernia]. / Das persistierende Müller-Gang-Syndrom : Ein seltener Zufallsbefund bei der Versorgung kindlicher Leistenhernien.

BACKGROUND: Persistent mullerian duct syndrome (PMDS) is a rare, autosomal recessive disorder. It is a form of male disorder of sexual differentiation in which mullerian duct structures are present in male phenotypes and 46XY karyotypes. In affected individuals, uterus, fallopian tubes, cervix and vagina are present. METHODS: A 2-month-old boy was admitted to hospital with a right-sided inguinal hernia. The physical examination showed a phenotypically normal boy with a right sided indirect inguinal hernia and impalpable testis. During herniotomy, a uterus and two fallopian tubes were found in the pelvic peritoneum adjacent to the two gonads. Initial biopsies were taken from the gonads and blood was sent for karyotyping. RESULTS: The biopsy showed normal testicular tissue without any ovarian tissue and the karyotyping result was 46XY; therefore, the diagnosis of persistent mullerian duct syndrome (PMDS) was made. In a second laparoscopically assisted operation the uterus and fallopian tubes were dissected, an orchidopexy of the left testis and an orchiectomy of the right testis were performed. The postoperative course was uneventful. CONCLUSION: In the case of an incarcerated inguinal hernia in combination with impalpable testis, a PMDS should be considered as a differential diagnosis.

X-ray scattering measurements of dissociation-induced metallization of dynamically compressed deuterium.

Hydrogen, the simplest element in the universe, has a surprisingly complex phase diagram. Because of applications to planetary science, inertial confinement fusion and fundamental physics, its high-pressure properties have been the subject of intense study over the past two decades. While sophisticated static experiments have probed hydrogen's structure at ever higher pressures, studies examining the higher-temperature regime using dynamic compression have mostly been limited to optical measurement techniques. Here we present spectrally resolved x-ray scattering measurements from plasmons in dynamically compressed deuterium. Combined with Compton scattering, and velocity interferometry to determine shock pressure and mass density, this allows us to extract ionization state as a function of compression. The onset of ionization occurs close in pressure to where density functional theory-molecular dynamics (DFT-MD) simulations show molecular dissociation, suggesting hydrogen transitions from a molecular and insulating fluid to a conducting state without passing through an intermediate atomic phase.

Free-electron X-ray laser measurements of collisional-damped plasmons in isochorically heated warm dense matter.

We present the first highly resolved measurements of the plasmon spectrum in an ultrafast heated solid. Multi-keV x-ray photons from the Linac Coherent Light Source have been focused to one micrometer diameter focal spots producing solid density aluminum plasmas with a known electron density of n_{e}=1.8×10^{23} cm^{-3}. Detailed balance is observed through the intensity ratio of up- and down-shifted plasmons in x-ray forward scattering spectra measuring the electron temperature. The plasmon damping is treated by electron-ion collision models beyond the Born approximation to determine the electrical conductivity of warm dense aluminum.

Equilibration dynamics and conductivity of warm dense hydrogen.

We investigate subpicosecond dynamics of warm dense hydrogen at the XUV free-electron laser facility (FLASH) at DESY (Hamburg). Ultrafast impulsive electron heating is initiated by a ≤ 300-fs short x-ray burst of 92-eV photon energy. A second pulse probes the sample via x-ray scattering at jitter-free variable time delay. We show that the initial molecular structure dissociates within (0.9 ± 0.2) ps, allowing us to infer the energy transfer rate between electrons and ions. We evaluate Saha and Thomas-Fermi ionization models in radiation hydrodynamics simulations, predicting plasma parameters that are subsequently used to calculate the static structure factor. A conductivity model for partially ionized plasma is validated by two-temperature density-functional theory coupled to molecular dynamic simulations and agrees with the experimental data. Our results provide important insights and the needed experimental data on transport properties of dense plasmas.

Evidence for a glassy state in strongly driven carbon.

Here, we report results of an experiment creating a transient, highly correlated carbon state using a combination of optical and x-ray lasers. Scattered x-rays reveal a highly ordered state with an electrostatic energy significantly exceeding the thermal energy of the ions. Strong Coulomb forces are predicted to induce nucleation into a crystalline ion structure within a few picoseconds. However, we observe no evidence of such phase transition after several tens of picoseconds but strong indications for an over-correlated fluid state. The experiment suggests a much slower nucleation and points to an intermediate glassy state where the ions are frozen close to their original positions in the fluid.

Resolving ultrafast heating of dense cryogenic hydrogen.

We report on the dynamics of ultrafast heating in cryogenic hydrogen initiated by a ≲300 fs, 92 eV free electron laser x-ray burst. The rise of the x-ray scattering amplitude from a second x-ray pulse probes the transition from dense cryogenic molecular hydrogen to a nearly uncorrelated plasmalike structure, indicating an electron-ion equilibration time of ∼0.9 ps. The rise time agrees with radiation hydrodynamics simulations based on a conductivity model for partially ionized plasma that is validated by two-temperature density-functional theory.

[Time of operative treatment of maldescensus testis in childhood - wishes and reality]. / Zeitpunkt der operativen Therapie des Maldescensus testis im Kindesalter: Wunsch und Wirklichkeit.

BACKGROUND: Maldescensus testis constitutes the most common diagnosis in the daily routine of a paediatric surgeon and is proved to be one of the most established risk factors for future infertility and malignancy. MATERIAL AND METHODS: We examined therapy strategies of paediatricians in the catchment area of the University Clinic of Würzburg in the light of the late time of orchidopexy. This study consists of a short survey sent to 100 local paediatricians. After return, the given answers were put in comparison to the 504 cases of retentio testis treated in our clinic from 2005 to 2010. RESULTS: Theoretical knowledge regarding guidelines for the treatment of retentio testis is abundant among paediatricians in and around Würzburg. Nevertheless, the initial therapy is of a hesitant character and often leads to an unnecessary delay in operation. The average age of boys receiving orchidopexy at our clinic between 2005 and 2010 amounted to 3.3 years. CONCLUSION: Regarding guidelines the average age of cryptorchid boys receiving orchidopexy at the University Clinic of Würzburg was way too high between 2005 and 2010. To some extent this fact can be attributed to the hesitant manner of therapy shown by local paediatricians. An improvement in the time of operation is definitely possible and necessary in order to optimise the outcome.

Thomson scattering on inhomogeneous targets.

The introduction of brilliant free-electron lasers enables new pump-probe experiments to characterize warm dense matter states. For instance, a short-pulse optical laser irradiates a liquid hydrogen jet that is subsequently probed with brilliant soft x-ray radiation. The strongly inhomogeneous plasma prepared by the optical laser is characterized with particle-in-cell simulations. The interaction of the soft x-ray probe radiation for different time delays between pump and probe with the inhomogeneous plasma is also taken into account via radiative hydrodynamic simulations. We calculate the respective scattering spectrum based on the Born-Mermin approximation for the dynamic structure factor considering the full density and temperature-dependent Thomson scattering cross section throughout the target. We can identify plasmon modes that are generated in different target regions and monitor their temporal evolution. Therefore, such pump-probe experiments are promising tools not only to measure the important plasma parameters density and temperature but also to gain valuable information about their time-dependent profile through the target. The method described here can be applied to various pump-probe scenarios by combining optical lasers and soft x ray, as well as x-ray sources.

[A delayed life-threatening complication after uneventful varicella infection: transient complete heart block]. / Späte bedrohliche Komplikation nach blande abgelaufener Varizellen-Infektion - transienter kompletter AV-Block (Fallbericht).

A 9 year old boy presented with uncharacteristic gastroenteric complaints due to a complete heart block 9 days after an uneventful varicella infection. Echocardiographically there were no signs of gross myocardial involvement. Bradydysrhythmia necessitated isoproterenol application however without the need for temporary transvenous cardiac pacing. After a short period of second-degree atrioventricular block and transient left bundle branch block the rhythm recovered completely and sinus rhythm is maintained so far. Worrying is the delayed onset of this complication after an uneventful course of a typically undangerous children's disease. Presumably a remaining inflammatory reaction in different parts of the specific conducting system has to be assumed. The long lasting prognosis of the atrioventricular conduction properties remains to be seen.

Increasing the efficiency and flexibility of capital funding for public and private hospitals.

This paper outlines the recent history of capital funding in the health sector in Australia. It focuses on the trends in capital expenditures and the roles of the public and private sectors. The demand for future capital funding will depend upon a number of factors, including the state of the current capital stock and uncertain future impacts of technology and changes in patient demands. Because of these uncertainties, capital funding for the future must be flexible to meet any changes in operations and demand. The paper highlights the possible use of joint ventures between various public and private organisations, based on the principles of competition and cooperation.

Functional identification of a delta8-sphingolipid desaturase from Borago officinalis.

The similarities between delta12- and delta5-fatty acyl desaturase sequences were used to construct degenerate primers for PCR experiments with cDNA transcribed from mRNA of developing borage seeds. Screening of a borage seed cDNA library with an amplified DNA fragment resulted in the isolation of a full-length cDNA corresponding to a deduced open-reading frame of 446 amino acids. The protein showed high similarity to plant delta8-sphingolipid desaturases as well as to the delta6-fatty acyl desaturase from Borago officinalis. The sequence is characterized by the presence of a N-terminal cytochrome b5 domain. Expression of this open-reading frame in Saccharomyces cerevisiae resulted in the formation of delta8-trans/cis-phytosphingenines not present in wild-type cells, as shown by HPLC analysis of sphingoid bases as their dinitrophenyl derivatives. GLC-MS analysis of the methylated di-O-trimethylsilyl ether derivatives confirmed the presence of delta8-stereoisomers of C18- and C20-phytosphingenine. Furthermore, Northern blotting showed that the gene encoding a stereo-unselective delta8-sphingolipid desaturase is primarily expressed in young borage leaves.

Functional characterization of sphingolipid C4-hydroxylase genes from Arabidopsis thaliana.

In the genome of Arabidopsis thaliana, two genes were identified encoding isoenzymes for C4-hydroxylation of long chain bases (LCB) in plant sphingolipids. Both predicted proteins consist of 258 amino acid residues (77% identity) which show sequence similarity to di-iron-binding enzymes, such as Sur2p and Erg3p from yeast, involved in oxygen-dependent lipid modifications. Heterologous expression of these genes in a yeast sur2Delta-null mutant lacking C4-LCB hydroxylation resulted in the formation of D-ribo-C(18)- and -C(20)-phytosphinganine. The identity and stereochemical configuration of the isolated trihydroxybases was confirmed by electrospray ionization-mass spectroscopy, gas-liquid chromatography-mass spectrometry and 1H-nuclear magnetic resonance spectroscopy. These results represent the first functional identification of SUR2 genes from plants as well as from any organism other than yeast.

Improvement of perineal wound healing by local administration of gentamicin-impregnated collagen fleeces after abdominoperineal excision of rectal cancer.

BACKGROUND: Despite significant advancements in rectal surgery, poor perineal wound healing after abdominoperineal resection (APR) of the anorectum continues to be a potential complication of the procedure. The aim of this prospective randomized multicenter study was to investigate the efficacy of a new mode of local antibiotic administration. PATIENTS AND METHODS: Ninety-seven patients who had to undergo APR for low rectal carcinoma either received sacral drainage plus primary wound closure (control group, n = 48) or the same treatment and supplementary application of three resorbable gentamicin-impregnated collagen fleeces (Septocoll; Merck Biomaterial GmbH, Darmstadt, Germany; Genta group, 49). The following target criteria were investigated: bacteriologic efficacy with respect to the eradication of Enterobacteriaceae, Staphylococcus, and Pseudomonas organisms, and clinical efficacy with respect to perineal wound healing. RESULTS: The Genta group showed a marked reduction in the investigated pathogens from the secretion obtained by sacral drainage on days 1 and 3, as well as high gentamicin concentrations (day 1, median 126.2 microg/mL; day 3, median 97.6 microg/mL). In total, bacteriologic efficacy amounted to 83.7% in the Genta group (41 of 49 patients) versus 60.4% (29 of 48 patients) in controls (P = 0.013). In concurrence with these bacteriologic results, the postoperative infection rate was significantly higher in controls: 10 patients (20.83%) in the control group versus 3 (6.1%) in the Genta group developed perineal or sacral infection (P <0.05). Postoperative complications in the recruited patients revealed no indication of gentamicin-induced adverse reactions. CONCLUSIONS: The results of the study show that the specified dose of 3 Septocoll fleeces in patients with APR is liable to significantly eliminate enterobacteria, staphylococci, and pseudomonads. The clinical course is improved as a result of the bactericidal effect exerted by the gentamicin fleece. The use of Septocoll reduced the incidence of postoperative perineal and sacral infections. Local antibiotic carriers seem to be of great advantage in poorly perfused areas such as the sacral cavity or anatomically problematic regions as the rima ani. In locally contaminated or infected areas, local antibiotic carriers achieve greater concentrations of the active substance than those achieved with systemic antibiotics, even if the latter are administered by the parenteral route.

A bifunctional delta-fatty acyl acetylenase/desaturase from the moss Ceratodon purpureus. A new member of the cytochrome b5 superfamily.

Many plant genes have been cloned that encode regioselective desaturases catalyzing the formation of cis-unsaturated fatty acids. However, very few genes have been cloned that encode enzymes catalyzing the formation of the functional groups found in unusual fatty acids (e.g. hydroxy, epoxy or acetylenic fatty acids). Here, we describe the characterization of an acetylenase from the moss Ceratodon purpureus with a regioselectivity differing from the previously described Delta12-acetylenase. The gene encoding this protein, together with a Delta6-desaturase, was cloned by a PCR-based approach with primers derived from conserved regions in Delta5-, Delta6-fatty-acid desaturases and Delta8-sphingolipid desaturases. The proteins that are encoded by the two cloned cDNAs are likely to consist of a N-terminal extension of unknown function, a cytochrome b5-domain, and a C-terminal domain that is similar to acyl lipid desaturases with characteristic histidine boxes. The proteins were highly homologous in sequence to the Delta6-desaturase from the moss Physcomitrella patens. When these two cDNAs were expressed in Saccharomyces cerevisiae, both transgenic yeast cultures desaturated Delta9-unsaturated C16- and C18-fatty acids by inserting an additional Delta6cis-double bond. One of these transgenic yeast clones was also able to introduce a Delta6-triple bond into gamma-linolenic and stearidonic acid. This resulted in the formation of 9,12,15-(Z,Z,Z)-octadecatrien-6-ynoic acid, the main fatty acid found in C. pupureus. These results demonstrate that the Delta6-acetylenase from C. pupureus is a bifunctional enzyme, which can introduce a Delta6cis-double bond into 9,12,(15)-C18-polyenoic acids as well as converting a Delta6cis-double bond to a Delta6-triple bond.

Further characterization of Delta(8)-sphingolipid desaturases from higher plants.

A previously cloned cDNA from Helianthus annuus codes for a fusion protein composed of an N-terminal cytochrome b(5) and a C-terminal desaturase domain. For a functional identification, this cDNA was expressed in Saccharomyces cerevisiae and the structures of sphingolipid long-chain bases were analysed. The expression of this sunflower enzyme resulted in the formation of new Delta(8)-trans/cis-phytosphingenine from C(18)- and C(20)-phytosphinganine present in wild-type yeast cells. To elucidate the substrate specificity, the recently cloned Delta(8)-sphingolipid desaturases from Arabidopsis thaliana and Brassica napus were expressed in the yeast mutant sur2Delta that lacked the sphinganine C(4)-hydroxylase and was thus unable to form phytosphinganine. Long-chain base analysis of the transformed mutant cells did not show any conversion of C(18)- or C(20)-sphinganine into Delta(8)-sphingenine, whereas exogenously added C(18)-phytosphinganine was desaturated to Delta(8)-trans/cis-phytosphingenine. Furthermore, GLC-MS analysis did not reveal the presence of any Delta(9)-regioisomers as reported before. These results show that the sunflower gene codes for a Delta(8)-sphingolipid desaturase which accepts C(18)- and C(20)-phytosphinganine. The absence of Delta(8)-sphingenine as desaturation product in the transformed mutant suggests that C(4)-hydroxylation of sphinganine precedes Delta(8)-desaturation. Therefore, in yeast, the substrate for the plant Delta(8)-sphingolipid desaturase seems to be the phytosphinganine residue.

A sphingolipid desaturase from higher plants. Identification of a new cytochrome b5 fusion protein.

A recently cloned cDNA from sunflower codes for a fusion protein composed of an N-terminal cytochrome b5 and a domain similar to membrane-bound acyl lipid desaturases. For a functional identification, homologous cDNAs from Brassica napus and Arabidopsis thaliana were expressed in Saccharomyces cerevisiae, and sphingolipid long chain bases were analyzed. The expression of the heterologous enzyme results in significant proportions of new Delta8, 9-cis/trans-phytosphingenines that accompany the residual C18-phytosphinganine predominating in wild-type yeast cells. These results represent the first identification of a gene coding for a sphingolipid desaturase and for a stereounselective desaturase showing trans-activity from any organism. Furthermore, this fusion protein is a new member of the cytochrome b5 superfamily. The formation of the two regioisomeric phytosphingenines in the transformed yeast sheds new light on the factors controlling regioselectivity.

The relationship of school breakfast to psychosocial and academic functioning: cross-sectional and longitudinal observations in an inner-city school sample.

OBJECTIVE: To determine if a relationship exists between participation in a school breakfast program and measures of psychosocial and academic functioning in school-aged children. METHODS: Information on participation in a school breakfast program, school record data, and in-depth interviews with parents and children were collected in 1 public school in Philadelphia, Pa, and 2 public schools in Baltimore, Md, prior to the implementation of a universally free (UF) breakfast program and again after the program had been in place for 4 months. One hundred thirty-three low-income students had complete data before and after the UF breakfast program on school breakfast participation and school-recorded measures, and 85 of these students had complete psychosocial interview data before and after the UF breakfast program. Teacher ratings of behavior before and after the UF breakfast program were available for 76 of these students. RESULTS: Schoolwide data showed that prior to the UF breakfast program, 240 (15%) of the 1627 students in the 3 schools were eating a school-supplied breakfast each day. Of the 133 students in the interview sample, 24 (18%) of the students ate a school-supplied breakfast often, 26 (20%) ate a school-supplied breakfast sometimes, and 83 (62%) ate a school-supplied breakfast rarely or never. Prior to the UF breakfast program, students who ate a school-supplied breakfast often or sometimes had significantly higher math scores and significantly lower scores on child-, parent-, and teacher-reported symptom questionnaires than children who ate a school-supplied breakfast rarely or never. At the end of the school term 4 months after the implementation of the UF breakfast program, school-supplied breakfast participation had nearly doubled and 429 (27%) of the 1612 children in the 3 schools were participating in the school breakfast program each day. In the interview sample, almost half of the children had increased their participation. Students who increased their participation in the school breakfast program had significantly greater increases in their math grades and significantly greater decreases in the rates of school absence and tardiness than children whose participation remained the same or decreased. Child and teacher ratings of psychosocial problems also decreased to a significantly greater degree for children with increased participation in the school breakfast program. CONCLUSION: Both cross-sectional and longitudinal data from this study provide strong evidence that higher rates of participation in school breakfast programs are associated in the short-term with improved student functioning on a broad range of psychosocial and academic measures.