Quasiparticle Poisoning of Superconducting Qubits from Resonant Absorption of Pair-Breaking Photons

The ideal superconductor provides a pristine environment for the delicate states of a quantum computer: because there is an energy gap to excitations, there are no spurious modes with which the qubits can interact, causing irreversible decay of the quantum state. As a practical matter, however, there exists a high density of excitations out of the superconducting ground state even at ultralow temperature; these are known as quasiparticles. Observed quasiparticle densities are of order 1  μm^{-3}, tens of orders of magnitude greater than the equilibrium density expected from theory. Nonequilibrium quasiparticles extract energy from the qubit mode and can induce dephasing. Here we show that a dominant mechanism for quasiparticle poisoning is direct absorption of high-energy photons at the qubit junction. We use a Josephson junction-based photon source to controllably dose qubit circuits with millimeter-wave radiation, and we use an interferometric quantum gate sequence to reconstruct the charge parity of the qubit. We find that the structure of the qubit itself acts as a resonant antenna for millimeter-wave radiation, providing an efficient path for photons to generate quasiparticles. A deep understanding of this physics will pave the way to realization of next-generation superconducting qubits that are robust against quasiparticle poisoning.

Osteolineage depletion of mitofusin2 enhances cortical bone formation in female mice

Mitochondria are essential organelles that form highly complex, interconnected dynamic networks inside cells. The GTPase mitofusin 2 (MFN2) is a highly conserved outer mitochondrial membrane protein involved in the regulation of mitochondrial morphology, which can affect various metabolic and signaling functions. The role of mitochondria in bone formation remains unclear. Since MFN2 levels increase during osteoblast (OB) differentiation, we investigated the role of MFN2 in the osteolineage by crossing mice bearing floxed Mfn2 alleles with those bearing Prx-cre to generate cohorts of conditional knock out (cKO) animals. By ex vivo microCT, cKO female mice, but not males, display an increase in cortical thickness at 8, 18, and 30 weeks, compared to wild-type (WT) littermate controls. However, the cortical anabolic response to mechanical loading was not different between genotypes. To address how Mfn2 deficiency affects OB differentiation, bone marrow-derived mesenchymal stromal cells (MSCs) from both wild-type and cKO mice were cultured in osteogenic media with different levels of β-glycerophosphate. cKO MSCs show increased mineralization and expression of multiple markers of OB differentiation only at the lower dose. Interestingly, despite showing the expected mitochondrial rounding and fragmentation due to loss of MFN2, cKO MSCs have an increase in oxygen consumption during the first 7 days of OB differentiation. Thus, in the early phases of osteogenesis, MFN2 restrains oxygen consumption thereby limiting differentiation and cortical bone accrual during homeostasis in vivo.

The tethering function of mitofusin2 controls osteoclast differentiation by modulating the Ca2+-NFATc1 axis

Dynamic regulation of the mitochondrial network by mitofusins (MFNs) modulates energy production, cell survival, and many intracellular signaling events, including calcium handling. However, the relative importance of specific mitochondrial functions and their dependence on MFNs vary greatly among cell types. Osteoclasts have many mitochondria, and increased mitochondrial biogenesis and oxidative phosphorylation enhance bone resorption, but little is known about the mitochondrial network or MFNs in osteoclasts. Because expression of each MFN isoform increases with osteoclastogenesis, we conditionally deleted MFN1 and MFN2 (double conditional KO (dcKO)) in murine osteoclast precursors, finding that this increased bone mass in young female mice and abolished osteoclast precursor differentiation into mature osteoclasts in vitro Defective osteoclastogenesis was reversed by overexpression of MFN2 but not MFN1; therefore, we generated mice lacking only MFN2 in osteoclasts. MFN2-deficient female mice had increased bone mass at 1 year and resistance to Receptor Activator of NF-κB Ligand (RANKL)-induced osteolysis at 8 weeks. To explore whether MFN-mediated tethering or mitophagy is important for osteoclastogenesis, we overexpressed MFN2 variants defective in either function in dcKO precursors and found that, although mitophagy was dispensable for differentiation, tethering was required. Because the master osteoclastogenic transcriptional regulator nuclear factor of activated T cells 1 (NFATc1) is calcium-regulated, we assessed calcium release from the endoplasmic reticulum and store-operated calcium entry and found that the latter was blunted in dcKO cells. Restored osteoclast differentiation by expression of intact MFN2 or the mitophagy-defective variant was associated with normalization of store-operated calcium entry and NFATc1 levels, indicating that MFN2 controls mitochondrion-endoplasmic reticulum tethering in osteoclasts.

Manipulation of the Alternative NF-κB Pathway in Mice Has Sexually Dimorphic Effects on Bone

Alternative NF‐κB signaling promotes osteoclastogenesis and pathological bone loss, but the effect of sex on phenotype has not been explored. We disrupted alternative NF‐κB signaling by deletion of upstream kinase NF‐κB‐inducing kinase (NIK) or NF‐κB subunit RelB and found that both NIK‐deficient and RelB‐deficient female mice possessed more than twofold higher trabecular bone mass compared to controls, whereas no differences were observed in males. In vitro, RelB‐deficient precursors from female mice showed a more severe osteoclast (OC) differentiation defect than male, while WT had no sex bias. Next, we asked whether pharmacologic activation of alternative NF‐κB by inhibitor of apoptosis (IAP) antagonist BV6 has sex‐dependent effects on bone. Unlike male mice that lost bone, female mice on BV6 for 4 weeks showed no changes in either trabecular bone mass or OC number. Because estrogen generally suppresses NF‐κB, we hypothesized that estrogen protects bone from BV6 effects in vivo. Thus, we performed ovariectomy or sham surgery in female mice, then treated with BV6 or vehicle for 4 weeks. Although ovariectomy caused bone loss, BV6 did not have any additional impact, suggesting that direct estrogen effects do not cause resistance to BV6 in vivo. The osteopenic effects of IAP antagonists in males may have implications for their use in cancer therapy. © 2018 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

A Randomized Controlled Trial on Oral Analgesic Utilization for Children Presenting With A Musculoskeletal Trauma in the Emergency Department

BACKGROUND: A single-agent approach to children’s moderate to severe pain is often inadequate. To date, no studies have evaluated the combined use of oral morphine and ibuprofen for optimal pain management of children presenting to an emergency department (ED) for muscu-loskeletal (MSK) trauma.

OBJECTIVES: To assess the efficacy of a combination of oral morphine and ibuprofen for pain management in children with MSK trauma in the ED.

DESIGN/METHODS: A double-blind, placebo-controlled, multi-centered, three-arm, randomized clinical trial of 500 patients was conducted at three pediatric tertiary care EDs. Patients were randomized (in a 2:1:1 ratio) to receive (orally): (a) morphine (0.2mg/kg) + ibuprofen (10mg/kg) (Group MOR + IBU) or (b) morphine (0.2 mg/kg) + placebo (Group MOR) or (c) ibuprofen (10mg/kg) + placebo (Group IBU). Patients 6 to 17 years of age, who presented to the ED with a MSK trauma, and a score >30 mm on the 100mm visual analogue scale were eligible to participate. Primary outcome was pain intensity score under 30 mm (mild pain) at 60-minutes (T-60) after treatment administration.

RESULTS: A total of 456 patients were included in analyses: 177 (MOR + IBU), 188 (MOR), 91 (IBU). Mean age was 11.9±2.7 years, with a majority of boys (55.3%) and Soft tissue injuries (62%). There were no differences in baseline characteristics in the three groups. Baseline mean pain score was 60.9±16.2 mm. Only 30% (MOR + IBU), 29% (MOR) and 30% (IBU) of patients reached a pain score under 30 mm at T-60 (p=0.83). Mean pain scores at T-60 were 42.3±23.2 mm (MOR + IBU), 43.8 + 23.1 mm (MOR) and 42.3±23.3 mm (IBU) (p=0.83). No severe adverse events were observed in any of the groups, at any of the study measurement points.

CONCLUSION: Combination of morphine with ibuprofen did not provide any additional pain relief for children with MSK injuries, in the ED. None of the study medication provided optimal pain management, as the majority of children did not reach the WHO definition of mild pain. Alternative analgesic combinations should be investigated to optimize pain relief of children who present to the ED with MSK injuries.

Synergistic, collaterally sensitive β-lactam combinations suppress resistance in MRSA

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most prevalent multidrug-resistant pathogens worldwide, exhibiting increasing resistance to the latest antibiotic therapies. Here we show that the triple β-lactam combination meropenem-piperacillin-tazobactam (ME/PI/TZ) acts synergistically and is bactericidal against MRSA subspecies N315 and 72 other clinical MRSA isolates in vitro and clears MRSA N315 infection in a mouse model. ME/PI/TZ suppresses evolution of resistance in MRSA via reciprocal collateral sensitivity of its constituents. We demonstrate that these activities also extend to other carbapenem-penicillin-β-lactamase inhibitor combinations. ME/PI/TZ circumvents the tight regulation of the mec and bla operons in MRSA, the basis for inducible resistance to β-lactam antibiotics. Furthermore, ME/PI/TZ subverts the function of penicillin-binding protein-2a (PBP2a) via allostery, which we propose as the mechanism for both synergy and collateral sensitivity. Showing in vivo activity similar to that of linezolid, ME/PI/TZ demonstrates that combinations of older β-lactam antibiotics could be effective against MRSA infections in humans.

Adenovirus-mediated overexpression of dominant-negative mutant of c-Jun prevents intercellular adhesion molecule-1 induction by LDL: a critical role for activator protein-1 in endothelial activation

Low density lipoprotein (LDL) induces intercellular adhesion molecule-1 (ICAM-1) gene expression and leads to endothelial cell (EC) leukocyte adhesion. However, the transcriptional mechanism for LDL-induced EC perturbation remains to be fully explained. Activator protein-1 (AP-1) is induced after the exposure of ECs to LDL. In the present study, a regulated adenovirus expressing a dominant-negative mutant of c-Jun (TAM-67) was used to examine the role of AP-1 in the LDL-induced ICAM-1 activation. Overexpression of TAM-67 specifically inhibited AP-1 activation and prevented the LDL-activated surface expression of ICAM-1 protein in human umbilical vein ECs and human coronary artery ECs. Northern analyses and promoter transactivation assays indicated that this effect of TAM-67 was likely mediated through a suppression of the transcriptional regulation of the ICAM-1 gene. Functionally, TAM-67 attenuated leukocyte adherence to ECs in response to LDL. Furthermore, electrophoresis mobility shift assays and site-directed mutagenesis suggested that an AP-1-like motif in the promoter region of the human ICAM-1 gene was a critical cis element for LDL induction. These results, for the first time, provide evidence suggesting that AP-1 is a major regulatory mechanism leading to endothelial activation.

Leptin enhances the calcification of vascular cells: artery wall as a target of leptin

Leptin, the product of the ob gene, regulates food intake, energy expenditure, and other physiological functions of the peripheral tissues. Leptin receptors have been identified in the hypothalamus and in extrahypothalamic tissues. Increased circulating leptin levels have been correlated with cardiovascular disease, obesity, aging, infection with bacterial lipopolysaccharide, and high-fat diets. All these conditions have also been correlated with increased vascular calcification, a hallmark of atherosclerotic and age-related vascular disease. In addition, the differentiation of marrow osteoprogenitor cells is regulated by leptin. Thus, we hypothesized that leptin may regulate the calcification of vascular cells. In this report, we tested the effects of leptin on a previously characterized subpopulation of vascular cells that undergo osteoblastic differentiation and calcification in vitro. When treated with leptin, these calcifying vascular cells had a significant 5- to 10-fold increase in alkaline phosphatase activity, a marker of osteogenic differentiation of osteoblastic cells. Prolonged treatment with leptin enhanced the calcification of these cells, further supporting the pro-osteogenic differentiation effects of leptin. Furthermore, the presence of the leptin receptor on calcifying vascular cells was demonstrated using reverse transcriptase polymerase chain reaction, immunocytochemistry, and Western blot analysis. We also identified the presence of leptin receptor in the mouse artery wall, localized to subpopulations of medial and adventitial cells, and the expression of leptin by artery wall cells and atherosclerotic lesions in mice. Taken together, these results suggest that leptin regulates the osteoblastic differentiation and calcification of vascular cells and that the artery wall may be an important peripheral tissue target of leptin action.

A comparison of the level of hope in patients with newly diagnosed and recurrent cancer

PURPOSE/OBJECTIVES

To compare levels of hope in patients with newly diagnosed and recurrent cancer.

DESIGN

Descriptive study.

SETTING

Three oncology practices in two urban areas of the southern United States.

SAMPLE

Convenience sample of 20 newly diagnosed patients with cancer and 16 patients with recurrent cancer (mean age = 56 years). The majority of the patients were Caucasian, female, and married; had a high school degree; and had a religious affiliation.

METHODS

Subjects completed the Herth Hope Scale and answered the open-ended question "What gives you the most hope at the present time?" Analysis included descriptive statistics (i.e., frequency, means, standard deviations, percents), t-tests, Chi-square, and analysis of variance.

MAIN RESEARCH VARIABLES

Level of hope each subject had in relation to the stage of the cancer at the time of diagnosis.

FINDINGS

Contrary to expectations, patients with newly diagnosed and recurrent cancer did not differ in regard to their level of hope. However, significant differences were found related to the type of hope utilized. Married patients and male patients experienced higher levels of hope. Recurrent themes in response to the open-ended question were family support, nonfamily support, faith, outlook, and health professionals/care.

CONCLUSIONS

Patients with newly diagnosed cancer use their treatment and nurses, physicians, and other healthcare professionals as sources of hope and support. Patients with recurrent cancer reported drawing hope from faith. IMPLICATIONS AND NURSING PRACTICE: Heightened awareness of the patient-healthcare professional relationship will enable healthcare professionals to provide care that is more sensitive to one congruent with patients' needs. Healthcare professionals need to assess the meaning of faith for each individual patient and offer services to foster this source of hope.

Genomic concatemerization/deletion in rotaviruses: a new mechanism for generating rapid genetic change of potential epidemiological importance

Three variants of group A rotavirus with large changes in their gene 5 structures have been analyzed at the molecular level. The first of these, P9 delta 5, was obtained during plaque purification undertaken as part of the biological cloning of a field isolate of virus. The gene 5 homolog in this isolate migrated just ahead of the normal segment 6 RNA, giving an estimated size of 1,300 bp. Molecular cloning and sequencing of this homolog revealed it to have a single 308-bp deletion in the center of the normal gene 5 sequence extending between nucleotides 460 and 768 of the normal gene sequence. This deletion caused a frameshift in the gene such that a stop codon was encountered 8 amino acids downstream of the deletion point, giving a predicted size for the protein product of this gene of 150 amino acids compared with the 490 amino acids of its normal-size counterpart. Attempts to detect this shortened protein in virus-infected cells were not successful, indicating that it was much less stable than the full-length protein and/or had suffered a large change in its antigenicity. The second two variants, brvA and brvE, were generated in an earlier study following the high-multiplicity passage of the UKtc strain of bovine rotavirus. Polyacrylamide gel electrophoresis analysis of these nondefective variants showed that brvA had a gene 5 homolog approximately equal in size to the normal RNA segment 2 (approximately 2,700 bp) and that brvE had a size of approximately 2,300 bp. Both variants showed changes in their gene 5 protein products, with brvA mimicking P9 delta 5 in failing to produce a detectable product whereas brvE produced a new virus-specific protein approximately 80 kDa in size. Full-length cDNA clones of the brvE gene 5 homolog were isolated, and analysis of their structure revealed a head-to-tail concatemerization of the normal gene 5 sequence with the first copy of the concatemer covering nucleotides 1 to 808 and the second covering nucleotides 92 to 1579, giving a total length of 2,296 bp. Sequencing across the junction region of the two copies of the gene showed that they were joined in frame to give a predicted combined open reading frame of 728 amino acids with the amino-terminal region consisting of amino acids 1 to 258 fused at the carboxy terminus to amino acids 21 to 490.(ABSTRACT TRUNCATED AT 400 WORDS)

A serotype 10 human rotavirus

Rotaviruses with genome rearrangements isolated from a chronically infected immunodeficient child (F. Hundley, M. McIntyre, B. Clark, G. Beards, D. Wood, I. Chrystie, and U. Desselberger, J. Virol 61:3365-3372, 1987) are the first recognized human isolates of serotype 10. This was shown by both a direct enzyme-linked immunosorbent assay and virus neutralization assays using serotype specific monoclonal antibodies. The serotype was confirmed by sequence analysis of the gene encoding VP7, which revealed a 96% amino acid homology to the bovine serotype 10 isolate B223.

Nucleotide sequences of normal and rearranged RNA segments 10 of human rotaviruses

Normal and rearranged RNA segments 10 of group A rotaviruses isolated from a chronically infected immunodeficient child were amplified by the polymerase chain reaction as full-length cDNA copies, and were subsequently cloned and sequenced. Compared with the nucleotide sequence of the normal RNA segment 10, the rearranged form contains a partial non-coding duplication at its 3' end and several point mutations. The normal RNA segment 10 was similar to that of bovine rotavirus.

Posterior cruciate ligament avulsion associated with ipsilateral femur fracture in a 10-year-old child

Ligamentous injuries to the knee do occur in children with open physes. Rarely, the posterior cruciate ligament may be involved and prompt attention to repair when recognized is encouraged. While avulsion occurs, more commonly, from the femoral insertion of the posterior cruciate, the tibial origin may be the site of injury, as in this case report. Complete examination of fractured femurs in children is therefore necessary. Early ligamentous repair is superior to later reconstruction.

Plantar fascial spaces of the foot and a proposed surgical approach

This study identified five plantar fascial spaces of the foot. The first space lies superficial to the calcaneus, the second lies between the plantar aponeurosis and the flexor digitorum brevis, the third lies between the flexor digitorum brevis and the quadratus plantar, the fourth lies above the quadratus, and the fifth lies above the adductor hallucis. A plantar incision is proposed for exploration and drainage of foot injuries and infections. With this incision, the plantar neurovascular bundles, along with the five plantar spaces through which infection spreads, are visualized clearly. In our experience, the incision heals without a sensitive scar.

Prophylactic antibiotics in elective orthopedic surgery: a prospective study of 1,591 cases

A double-blind prospective study involving 1,591 clean orthopedic surgical procedures was done to test the effectiveness of preoperative and intraoperative antibiotics in reducing the postoperative infection rate. The antibiotic and placebo groups were analyzed carefully for factors known to predispose to infection. Several minor exceptions were noted, but generally the antibiotic and placebo groups were comparable with regard to these factors. A decrease in overall postoperative infection rate from 5.0% in the placebo group to 2.8% in the antibiotic group was found. In specific areas such as the hip and spine a much greater reduction in postoperative wound infections occurred than in the group as a whole.

The functional treatment of pyogenic arthritis of the adult knee

A method of treatment of pyogenic arthritis of the adult knee employing wide open arthrotomy and early active motion, as well as synovectomy in some knees, was used in thirty-four patients with pyogenic arthritis of the knee. Of these patients, sixteen had a good result, twelve had a fair result, and six had a poor result. This method of treatment was used as a salvage procedure in most of the patients, but may have more general application in the treatment of pyogenic arthritis of the knee.