Studying turbulence in a fluid with background damping.

In this experimental paper, we demonstrate that turbulence can develop in a fluid system with background damping. For that purpose, we analyze dust acoustic waves, self-excited in a fluid complex plasma where the motion of individual microparticles was recorded with a high-speed video camera. We use the Wiener-Khinchin theorem to calculate the kinetic spectrum during different phases of the highly nonlinear periodic wave motion and show that a turbulent cascade develops at the phases of highest particle compression. We demonstrate that the energy cascade occurs despite the presence of a damping force due to the background neutral gas.

Spatial distribution of dust density wave properties in fluid complex plasmas.

Complex plasmas consist of microparticles embedded in a low-temperature plasma and allow investigating various effects by tracing the motion of these microparticles. Dust density waves appear in complex plasmas as self-excited acoustic waves in the microparticle fluid at low neutral gas pressures. Here we show that various properties of these waves depend on the position of the microparticle cloud with respect to the plasma sheath and explain this finding in terms of the underlying ion-drift instability. These results may be helpful in better understanding the propagation of dust density waves in complex plasmas and beyond, for instance, in astrophysical dusty plasmas.

The cost of implanting a cemented versus cementless total knee arthroplasty.

AIMS: The aim of this study was to compare the actual cost of a cemented and cementless total knee arthroplasty (TKA) procedure. MATERIALS AND METHODS: The cost of operative time, implants, cement, and cementing accessories were included in the overall cost of the TKA procedure. Operative time was determined from a previously published study comparing cemented and cementless implants of the same design. The cost of operative time, implants, cement, and cementing accessories was determined from market and institutional data. RESULTS: Mean operative time for cemented TKA was 11.6 minutes longer for cemented TKA than cementless TKA (93.7 minutes (sd 16.7) vs 82.1 minutes (sd 16.6); p = 0.001). Using a conservative published standard of $36 per minute for operating theatre time cost, the total time cost was $418 higher for cementing TKA. The cost of cement and accessories ranged from $170 to $625. Overall, the calculated cost of cemented TKA is $588 to $1043, depending on technique. The general increased charge for cementless TKA implants over cemented TKA implants was $366. CONCLUSION: The overall procedural cost of implanting a cementless TKA is less than implanting a cemented TKA. Cost alone should not be a barrier to using cementless TKA. Cite this article: Bone Joint J 2019;101-B(7 Supple C):61-63.

Instability onset and scaling laws of an auto-oscillating turbulent flow in a complex plasma.

We study a complex plasma under microgravity conditions that is first stabilized with an oscillating electric field. Once the stabilization is stopped, the so-called heartbeat instability develops. We study how the kinetic energy spectrum changes during and after the onset of the instability and compare with the double cascade predicted by Kraichnan and Leith for two-dimensional turbulence. The onset of the instability manifests clearly in the ratio of the reduced rates of cascade of energy and enstrophy and in the power-law exponents of the energy spectra.

Simulating the dynamics of complex plasmas.

Complex plasmas are low-temperature plasmas that contain micrometer-size particles in addition to the neutral gas particles and the ions and electrons that make up the plasma. The microparticles interact strongly and display a wealth of collective effects. Here we report on linked numerical simulations that reproduce many of the experimental results of complex plasmas. We model a capacitively coupled plasma with a fluid code written for the commercial package comsol. The output of this model is used to calculate forces on microparticles. The microparticles are modeled using the molecular dynamics package lammps, which we extended to include the forces from the plasma. Using this method, we are able to reproduce void formation, the separation of particles of different sizes into layers, lane formation, vortex formation, and other effects.

Fluid-solid phase transitions in three-dimensional complex plasmas under microgravity conditions.

Phase behavior of large three-dimensional (3D) complex plasma systems under microgravity conditions onboard the International Space Station is investigated. The neutral gas pressure is used as a control parameter to trigger phase changes. Detailed analysis of structural properties and evaluation of three different melting-freezing indicators reveal that complex plasmas can exhibit melting by increasing the gas pressure. Theoretical estimates of complex plasma parameters allow us to identify main factors responsible for the observed behavior. The location of phase states of the investigated systems on a relevant equilibrium phase diagram is estimated. Important differences between the melting process of 3D complex plasmas under microgravity conditions and that of flat 2D complex plasma crystals in ground based experiments are discussed.

Nonviscous motion of a slow particle in a dust crystal under microgravity conditions.

Subsonic motion of a large particle moving through the bulk of a dust crystal formed by negatively charged small particles is investigated using the PK-3 Plus laboratory onboard the International Space Station. Tracing the particle trajectories shows that the large particle moves almost freely through the bulk of the plasma crystal, while dust particles move along characteristic α-shaped pathways near the large particle. In the hydrodynamic approximation, we develop a theory of nonviscous dust particle motion about a large particle and calculate particle trajectories. Good agreement with experiment validates our approach.

Influence of stress and temperature on damping behavior of amorphous Pd77.5Cu6.0Si 16.5 below Tg.

In this work we analyzed the mechanical damping behavior of amorphous Pd(77.5)Cu(6.0)Si(16.5) below the glass transition temperature (T(g)) with creep/recovery measurements. Here a correlation between temperature stimulation and external stress is found in an exponential, multiplicative way. This demonstrates that not only is the yield stress of the material influenced by temperature variation (mechanical melting) but also the secondary relaxation is modified under stress and temperature.

Pattern formation in a complex plasma in high magnetic fields.

Low-pressure room-temperature neon, argon, krypton, and air plasmas were studied in magnetic fields up to flux densities of 2.3 T. Filaments appeared parallel to the magnetic field lines, and patterns such as spirals and concentric circles formed in the perpendicular direction. We link these effects to the magnetization of the ions. We also used a layer of embedded microparticles as probes in the plasma. Their motion changed dramatically from a collective rotation of the whole ensemble in moderate magnetic fields to a rotation in several small vortices centered at the filaments.

Formation of bubbles, blobs, and surface cusps in complex plasmas.

Investigations of the dynamical evolution of a complex plasma, in which a vertical temperature gradient compensates gravity, were carried out. At low power the formation of microparticle bubbles, blobs, and spraying cusps was observed. This activity can be turned on and off by changing control parameters, such as the rf power and the gas pressure. Several observational effects indicate the presence of surface tension, even at small "nanoscales" of a few 100's of particles. By tracing the individual microparticle motion the detailed (atomistic) dynamics can be studied as well as the pressure dependence of the forces. A possible mechanism that could drive the observed phenomena is analogous to the Rayleigh-Taylor instability.

[Poorly differentiated neuroendocrine carcinoma of the larynx. Diagnostic features, treatment strategy, and prognosis]. / Gering differenziertes neuroendokrines Larynxkarzinom. Diagnostische Besonderheiten, Therapiestrategie und Prognose.

BACKGROUND: Small cell carcinoma of the larynx is a rare, poorly differentiated neuroendocrine carcinoma (NEC). It is often diagnosed late, with delayed initiation of adequate therapy. PATIENTS AND METHODS: The data for eight patients were retrospectively analyzed with regard to clinical information, surveillance, and diagnostic and therapeutic strategies. RESULTS: The histopathologic diagnosis was made after a mean of 2.88+/-2.52 months after the first symptoms occurred. Staging and exclusion of an extralaryngeal primary was completed 1.75+/-1.7 months after the histological diagnosis. Seventy-five percent (n=6) of the patients already had regional or systemic metastases. Systemic metastases were detected in 50% (n=4) of the patients by FDG-positron emission tomography/computed tomography. Primary (n=4) or postoperative (n=3) radiochemotherapy was performed 3.07+/-1.32 months after initial diagnosis. Overall survival (n=6) was 12.83 +/-3.76 months. CONCLUSION: Studies providing high-level evidence cannot be expected because of the low incidence of small cell NEC. Efficient diagnosis should be followed immediately by combined radiochemotherapy. As with small cell bronchial carcinoma, small cell NEC of the larynx should be regarded as a systemic disease and be treated in a similar way.

Highly resolved self-excited density waves in a complex plasma.

Experimental results on self-excited density waves in a complex plasma are presented. An argon plasma is produced in a capacitively coupled rf discharge at a low power and gas pressure. A cloud of microparticles is subjected to effective gravity in the range of 1-4 g by thermophoresis. The cloud is stretched horizontally (width/height approximately 45 mm/8 mm). The critical pressure for the onset of the waves increases with the temperature gradient. The waves are propagating in the direction of the ion drift. The wave frequency, phase velocity, and wavelength are measured, and particle migrations affected by the waves are analyzed at a time scale of 1 ms/frame and a subpixel space resolution.

Cure of ventriculitis and central nervous system shunt infection by Staphylococcus epidermidis with vancomycin by intraventricular injection in a liver transplant recipient.

A 19-year-old female underwent orthotopic liver transplantation for acute hepatic failure because of fulminant Wilson's disease. Three months post transplantation she developed systemic fungal meningoencephalitis and obstructive hydrocephalus that required cerebrospinal fluid (CSF) shunting by a ventriculo-atrial shunt. Subsequently, she contracted Staphylococcus epidermidis bacteremia, ventriculitis, and shunt infection. Treatment with vancomycin either by conventional intravenous (i.v.) or continuous i.v. injection proved ineffective because of insufficient drug concentrations in the CSF. Eradication of S. epidermidis from CSF and cure of chronic ventriculitis and shunt infection was readily achieved by delivering vancomycin by intraventricular injection (5 mg/24 h) via an extraventricular drain together with continuous i.v. infusion (4 g/24 h) over a period of 18 days. This treatment was well tolerated and free of untoward side effects despite the patient's chronic immunosuppression subsequent to liver transplantation. Intraventricular injection of vancomycin is an effective and safe procedure to eradicate S. epidermidis from the central nervous system when i.v. vancomycin treatment fails.

Epigenetic lesions in malignant melanoma.

Malignant melanoma arises through a series of genetic and epigenetic events. A more profound understanding of the biology of metastatic melanoma should greatly aid in the development of new and effective treatments. Currently, avenues being pursued to improve treatment of metastatic melanoma include dendritic cell vaccines and other vaccination strategies, tyrosine kinase inhibitors, adoptive transfer of ex vivo stimulated T cells, and, as reviewed here, epigenetic approaches. The "methylator phenotype", with inactivation by promoter hypermethylation of numerous genes in malignant melanoma cell lines and primary tumors (p16, PTEN, RASSF1, estrogen receptor, retinoic acid receptor beta, SOCS1 and -2, MGMT etc.) offers a strong rationale for treatment approaches based on the use of DNA demethylating agents. The clinical literature on treatment of metastasized malignant melanoma with either 5-azacytidine or 5-aza-2'-deoxycytidine (decitabine) is reviewed. Future trials in malignant melanoma with these compounds might profit from prolonged low-dose exposure, since they unfold their full effects not immediately but with a certain delay, which may be associated with their DNA demethylating activity. Combinations of DNA demethylation agents with either histone deacetylase inhibitors, interleukin-2, chemotherapy or tamoxifen have been embarked on both in in vitro models of melanoma and recent clinical trials. The in vitro synergism between inhibitors of DNA methylation and histone deacetylation strongly invites a systematic study of combinations of both groups of agents. Up-regulation of cancer testis antigens by epigenetic therapy in melanoma also offers a very strong rationale to place these drugs and schedules within a larger treatment concept of immunotherapy which may include also T cell activation e.g. by interleukin-2, and vaccination strategies. In conclusion, the epigenome of malignant melanoma, with a well-established in vitro reversal potential, holds promise as a novel molecular target.

[Congenital cystic lung malformations]. / Konnatale zystische Lungenfehlbildungen.

PURPOSE: The aim of the study concerning congenital cystic lung malformations was to evaluate prenatal diagnoses postnatally to determine prognostic factors as well as to define optimized perinatal management. MATERIALS AND METHODS: The study is based on 45 prenatal ultrasound examinations depicting fetal cystic lung lesions. 32 of the mothers had follow-up examinations. 5 pregnancies were terminated due to CCAM and additional malformations. Complete regression of the lesions was seen prenatally in 8 cases and postnatally in 5 children. RESULTS: Surgical intervention due to respiratory insufficiency was necessary in 4 neonates. According to the imaging results, CCAM was present in 4 cases and sequestration in 7 patients. No correlation between the imaging findings and the surgical results was found in 3 children: One child suffered from rhadomyoid dysplasia, and in the case of the second child, a left-sided hernia of the diaphragm and additional sequestration were detected. The third child showed AV malformation. The cystic lesions of the 14 children operated upon were proven histologically. The degree of accuracy in the present study was high. CONCLUSION: Precise perinatal management is warranted in order to determine according to the clinical relevance surgical intervention and to prevent complications after the first year of life. This is performed during the neonatal period for respiratory insufficient neonates and within the first year of life for clinically stable children.

[Prenatal diagnosis of right atrial isomerism (asplenia-syndrome): case report]. / Pränatale Diagnose der rechtsatrialen Isomerie (Apslenie-Syndrom): ein Fallbericht.

Right atrial isomerism (earlier known as asplenia) is a group of malformations including anomalies of the heart and the visceral organs. Complex defects of the heart are normally found, but these are non-specific. The suspected diagnosis can be confirmed most easily by focusing on a specific and segmental examination of the heart. We report on a fetus referred at 22 weeks in whom AV-septal defect was detected. Heart and stomach were on the left side, but the segmental approach allowed the detection of juxtaposed descending aorta and inferior vena cava as typical signs of right isomerism. The suspected malformation could be verified by the additional detection of infra-diaphragmatic total anomalous pulmonary venous drainage by using colour Doppler. Howell-Jolly bodies from fetal blood supported the diagnosis of asplenia. Autopsy after termination of pregnancy demonstrated the typical signs of right isomerism. The paper reviews the typical prenatal findings which lead to the detection of right isomerism in the fetus. Segmental approach should be performed in each fetus with an anomaly of the heart especially in the presence of complex defects.

Treatment with granulocyte colony-stimulating factor increases interleukin-1 receptor antagonist levels during engraftment following allogeneic stem-cell transplantation.

BACKGROUND: The effect of treatment with granulocyte colony-stimulating factor (G-CSF) on interleukin-1 receptor antagonist (IL-1ra) plasma concentrations as well as the role of IL-1ra on leucocyte recovery and parameters of infection within the first 30 days after haematopietic stem-cell transplantation (HSCT) are not well known. MATERIAL AND METHODS: Twenty-seven patients undergoing myeloablative therapy followed by allogeneic SCT for various haematological disorders were either treated with (n = 18) or without (n = 9) G-CSF. IL-1ra plasma levels were serially determined by ELISA starting at day - 1 and continued until patients were engrafted. RESULTS: Patients receiving G-CSF had significantly shorter neutropenic periods and significantly lower mean C-reactive protein serum levels during the first 3 weeks succeeding bone marrow transplantation (BMT). Importantly, starting at day + 11 and paralleling the rise of peripheral blood leucocytes, increasing IL-1ra plasma concentrations were observed in both treatment groups. However, the magnitude of the IL-1ra surge was far greater in the G-CSF treatment group. Peak IL-1ra plasma level observed on day + 19 was 882.3 +/- 879.2 pg mL(-1) (mean +/- SD) in patients receiving G-CSF compared with 285.8 +/- 175.2 pg mL(-1) (mean +/- SD) in patients not receiving G-CSF (P = 0.0130). Furthermore, a direct correlation of IL-1ra with peripheral blood leucocytes was verified by the Spearman rank test (P = 0.0025). CONCLUSION: Granulocyte colony-stimulating factor-mediated acceleration of neutrophil recovery following myeloablative therapy correlated with increased IL-1ra plasma concentrations. Our data suggest that IL-1ra constitutes an intrinsic component of the anti-inflammatory and neutrophil differentiating efficacy of G-CSF and, thus, IL-1ra may be required for the in vivo activity of G-CSF.

Prenatal diagnosis of an isochromosome 5p in a fetus with increased nuchal translucency thickness and pulmonary atresia with hypoplastic right heart at 14 weeks.

We report on a fetus presenting with increased nuchal translucency at 11 weeks' gestation, suggesting cystic hygroma. Chorion villous sampling was performed, and cytogenetic analysis revealed a supernumerary isochromosome 5p leading to tetrasomy 5p: 47,XX,+ i(5p)[7]/46,XX[5] after short-term culture and 47,XX,+ i(5p)[20] after long-term culture. Subsequent targeted sonographic follow-up at 12 and 14 weeks revealed further increase of the NT to 6.4 mm and the additional presence of a congenital heart defect (pulmonary atresia with intact ventricular septum). Termination of pregnancy was performed, and the heart defect was confirmed. Isochromosome 5p was found in varying proportions in all examined organs. Only a few cases of mosaic tetrasomy 5p have been reported in the literature, and recent reports on prenatally detected isochromosome 5p showed a possible relationship to increased nuchal translucency in some cases and also a possible role of confined mosaicism in others. Whereas cases with confined mosaicism did not show suspicious signs on ultrasound, true mosaicism conversely showed increased nuchal thickness as well as structural abnormalities. This is the first report on the association of a cardiac defect with this chromosome aberration.