Superconducting Fluxon Pumps and Lenses

We study stochastic transport of fluxons in superconductors by alternating current (AC) rectification. Our simulated system provides a fluxon pump, "lens", or fluxon "rectifier" because the applied electrical AC is transformed into a net DC motion of fluxons. Thermal fluctuations and the asymmetry of the ratchet channel walls induce this "diode" effect, which can have important applications in devices, like SQUID magnetometers, and for fluxon optics, including convex and concave fluxon lenses. Certain features are unique to this novel two-dimensional (2D) geometric pump, and different from the previously studied 1D ratchets.Comment: Phys. Rev. Lett. 83, in press (1999); 4 pages, 5 .gif figures; figures also available at http://www-personal.engin.umich.edu/~nori/ratche

Reduction of circulating cholesterol and apolipoprotein levels during sepsis

Sepsis with multiple organ failure is frequently associated with a substantial decrease of cholesterol levels. This decrease of cholesterol is strongly associated with mortality suggesting a direct relation between inflammatory conditions and altered cholesterol homeostasis. The host response during sepsis is mediated by cytokines and growth factors, which are capable of influencing lipid metabolism. Conversely lipoproteins are also capable of modulating cytokine production during the inflammatory response. Therefore the decrease in circulating cholesterol levels seems to play a crucial role in the pathophysiology of sepsis. In this review the interaction between cytokines and lipid metabolism and its clinical consequences will be discussed

The Relativistic Electrodynamics Least Action Principles Revisited: New Charged Point Particle and Hadronic String Models Analysis

The classical relativistic least action principle is revisited from the vacuum field theory approach. New physically motivated versions of relativistic Lorentz type forces are derived, a new relativistic hadronic string model is proposed and analyzed in detail.Comment: n/

Spontaneous supercrystal formation during a strain-engineered metal-insulator transition

Mott metal-insulator transitions possess electronic, magnetic, and structural degrees of freedom promising next generation energy-efficient electronics. We report a previously unknown, hierarchically ordered state during a Mott transition and demonstrate correlated switching of functional electronic properties. We elucidate in-situ formation of an intrinsic supercrystal in a Ca2RuO4 thin film. Machine learning-assisted X-ray nanodiffraction together with electron microscopy reveal multi-scale periodic domain formation at and below the film transition temperature (TFilm ~ 200-250 K) and a separate anisotropic spatial structure at and above TFilm. Local resistivity measurements imply an intrinsic coupling of the supercrystal orientation to the material's anisotropic conductivity. Our findings add an additional degree of complexity to the physical understanding of Mott transitions, opening opportunities for designing materials with tunable electronic properties

Rhodococcus equi venous catheter infection: a case report and review of the literature

<p>Abstract</p> <p>Introduction</p> <p><it>Rhodococcus equi </it>is an animal pathogen that was initially isolated from horses and is being increasingly reported as a cause of infection in humans with impaired cellular immunity. However, this pathogen is underestimated as a challenging antagonist and is frequently considered to be a mere contaminant despite the potential for life-threatening infections. Most case reports have occurred in immunocompromised patients who have received organ transplants (for example kidney, heart, bone marrow) or those with human immunodeficiency virus infection. Infections often manifest as pulmonary involvement or soft tissue abscesses. Bacteremia related to <it>R. equi </it>infections of tunneled central venous catheters has rarely been described.</p> <p>Case presentation</p> <p>We report the case of a 63-year-old non-transplant recipient, non-HIV infected Caucasian woman with endometrial carcinoma who developed recurrent bloodstream infections and septic shock due to <it>R. equi </it>and ultimately required the removal of her port catheter, a subcutaneous implantable central venous catheter. We also review the medical literature related to human infections with <it>R. equi</it>.</p> <p>Conclusion</p> <p><it>R. equi </it>should be considered a serious pathogen, not a contaminant, particularly in an immunocompromised patient who presents with a central venous catheter-related bloodstream infection. Counseling patients with central venous catheters who participate in activities involving exposure to domesticated animals is recommended.</p

Rhodococcus Bacteremia in Cancer Patients Is Mostly Catheter Related and Associated with Biofilm Formation

Rhodococcus is an emerging cause of opportunistic infection in immunocompromised patients, most commonly causing cavitary pneumonia. It has rarely been reported as a cause of isolated bacteremia. However, the relationship between bacteremia and central venous catheter is unknown. Between 2002 and 2010, the characteristics and outcomes of seventeen cancer patients with Rhodococcus bacteremia and indwelling central venous catheters were evaluated. Rhodococcus bacteremias were for the most part (94%) central line-associated bloodstream infection (CLABSI). Most of the bacteremia isolates were Rhodococcus equi (82%). Rhodococcus isolates formed heavy microbial biofilm on the surface of polyurethane catheters, which was reduced completely or partially by antimicrobial lock solution. All CLABSI patients had successful response to catheter removal and antimicrobial therapy. Rhodococcus species should be added to the list of biofilm forming organisms in immunocompromised hosts and most of the Rhodococcus bacteremias in cancer patients are central line associated

The impact of highly active antiretroviral therapy on prevalence and incidence of cervical human papillomavirus infections in HIV-positive adolescents

Abstract Background The implementation of highly active antiretroviral therapy (HAART) among HIV-positive patients results in immune reconstitution, slower progression of HIV disease, and a decrease in the occurrence of opportunistic infections. However, the impact of HAART on cervical human papillomavirus (HPV) infection, clearance, and persistence in high-risk adolescents remains controversial. Methods HIV-positive and high-risk HIV-negative female adolescents were enrolled in the Reaching for Excellence in Adolescent Care and Health (REACH) longitudinal cohort study. At each semi-annual clinical visit, cervical lavage samples were tested for 30 HPV types. Type-specific and carcinogenic risk-specific HPV prevalence and incidence were compared in 373 eligible participants: 146 HIV-negative female adolescents with a median follow-up of 721.5 [IQR: 483-1301] days and 227 HIV-positive female adolescents. Of the 227 HIV-positive participants, a fixed set (n = 100) were examined both before and after HAART initiation; 70 were examined only before HAART initiation; and 57 were examined only after HAART initiation, with overall median follow-up of 271 [IQR: 86.5-473] and 427.25 [IQR: 200-871] days respectively for before and after HAART initiation. Results Of the 373 eligible participants, 262 (70%) were infected with at least one type of HPV at baseline, and 78 of the remaining 111 (70%) became infected with at least one type of HPV by the end of the study. Overall, the incidence and prevalence of HPV types 58, 53/66, 68/70, and 31/33/35 were much higher than the established carcinogenic and HPV vaccine types 16 and 18, especially in HIV-positive females both before and after HAART initiation. Baseline prevalence for individual high-risk HPV types ranged, depending on type, from 0.7-10%, 1-17%, and 1-18% in the HIV-negative group, the HIV-positive before HAART initiation group, and the HIV-positive after HAART initiation group, respectively. Likewise, the incidence ranged, depending on HPV type, from 0.64-9.83 cases/100 PY, 3.00-12.80 cases/100 PY, and 1.49-17.05 cases/100 PY in the three groups, respectively. The patterns of each HPV type infection, clearance, and persistence did not differ considerably before or after the introduction of HAART and were clearly independent of CD4+ change within the short post-HAART follow-up period. Conclusions HAART did not immediately affect the incidence of type-specific HPV infections within a short-period follow-up; however, future studies are warranted in larger populations to evaluate HAART's impact over longer periods

The Vacuum Structure, Special Relativity and Quantum Mechanics Revisited: a Field Theory No-Geometry Approach within the Lagrangian and Hamiltonian Formalisms. Part 2

The main fundamental principles characterizing the vacuum field structure are formulated and the modeling of the related vacuum medium and charged point particle dynamics by means of devised field theoretic tools are analyzed. The work is devoted to studying the vacuum structure, special relativity, electrodynamics of interacting charged point particles and quantum mechanics, and is a continuation of \cite{BPT,BRT1}. Based on the vacuum field theory no-geometry approach, the Lagrangian and Hamiltonian reformulation of some alternative classical electrodynamics models is devised. The Dirac type quantization procedure, based on the canonical Hamiltonian formulation, is developed for some alternative electrodynamics models. Within an approach developed a possibility of the combined description both of electrodynamics and gravity is analyzed.Comment: 11 page

ATM Limits Incorrect End Utilization during Non-Homologous End Joining of Multiple Chromosome Breaks

Chromosome rearrangements can form when incorrect ends are matched during end joining (EJ) repair of multiple chromosomal double-strand breaks (DSBs). We tested whether the ATM kinase limits chromosome rearrangements via suppressing incorrect end utilization during EJ repair of multiple DSBs. For this, we developed a system for monitoring EJ of two tandem DSBs that can be repaired using correct ends (Proximal-EJ) or incorrect ends (Distal-EJ, which causes loss of the DNA between the DSBs). In this system, two DSBs are induced in a chromosomal reporter by the meganuclease I-SceI. These DSBs are processed into non-cohesive ends by the exonuclease Trex2, which leads to the formation of I-SceI–resistant EJ products during both Proximal-EJ and Distal-EJ. Using this method, we find that genetic or chemical disruption of ATM causes a substantial increase in Distal-EJ, but not Proximal-EJ. We also find that the increase in Distal-EJ caused by ATM disruption is dependent on classical non-homologous end joining (c-NHEJ) factors, specifically DNA-PKcs, Xrcc4, and XLF. We present evidence that Nbs1-deficiency also causes elevated Distal-EJ, but not Proximal-EJ, to a similar degree as ATM-deficiency. In addition, to evaluate the roles of these factors on end processing, we examined Distal-EJ repair junctions. We found that ATM and Xrcc4 limit the length of deletions, whereas Nbs1 and DNA-PKcs promote short deletions. Thus, the regulation of end processing appears distinct from that of end utilization. In summary, we suggest that ATM is important to limit incorrect end utilization during c-NHEJ