46 research outputs found

    Gravitational wave search through electromagnetic telescopes

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    We study the graviton-photon conversion in the magnetic fields of the Earth, our galaxy, and intergalactic regions. Requiring that the photon flux converted from gravitons does not exceed the observed photon flux with telescopes, we derive upper limits on the stochastic gravitational waves in frequency ranges from 10710^{7}Hz to 103510^{35}Hz. Remarkably, the upper limits on h2ΩGWh^2 \Omega_{{\rm GW}} could be less than unity in the frequency range of 101810^{18}-102310^{23} Hz in a specific case. The detection of gravitational waves using telescopes would open up a new avenue for high frequency gravitational wave observations and offer exciting opportunities to probe new physics.Comment: 10 pages, 4 figure

    Effects of Finite Material Size On Axion-magnon Conversion

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    Magnetic materials are particularly favorable targets for detecting axions interacting with electrons because the collective excitation of electron spins, the magnon, can be excited through the axion-magnon conversion process. It is often assumed that only the zero-momentum uniformly precessing magnetostatic (Kittel) mode of the magnon is excited. This is justified if the de Broglie wavelength of the axion is much longer than the size of the target magnetic material. However, if the de Broglie wavelength is shorter, finite-momentum magnon modes can also be excited. We systematically analyze the target material size dependence of the axion-magnon conversion rate. We discuss the importance of these effects in the detection of relativistic axions as well as in the detection of axion dark matter of relatively heavy mass with large material size.Comment: 22 pages, 3 figure

    Unusual surface states associated with the PT-symmetry breaking and antiferromagnetic band folding in NdSb

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    We have performed micro-focused angle-resolved photoemission spectroscopy on NdSb which exhibits the type-I antiferromagnetism below TN = 16 K. We succeeded in selectively observing the band structure for all the three types of single-q antiferromagnetic (AF) domains at the surface. We found that the two of three surfaces whose AF-ordering vector lies within the surface plane commonly show two-fold-symmetric surface states (SSs) around the bulk-band edges, whereas the other surface with an out-of-plane AF-ordering vector displays four-fold-symmetric shallow electronlike SS at the Brillouin-zone center. We suggest that these SSs commonly originate from the combination of the PT (space-inversion and time-reversal) symmetry breaking at the surface and the band folding due to the AF order. The present results pave a pathway toward understanding the relationship between the symmetry and the surface electronic states in antiferromagnets.Comment: 20 pages, 5 figure

    Extensive Atrophic Gastritis Increases Intraduodenal Hydrogen Gas

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    Objective. Gastric acid plays an important part in the prevention of bacterial colonization of the gastrointestinal tract. If these bacteria have an ability of hydrogen (H2) fermentation, intraluminal H2 gas might be detected. We attempted to measure the intraluminal H2 concentrations to determine the bacterial overgrowth in the gastrointestinal tract. Patients and methods. Studies were performed in 647 consecutive patients undergoing upper endoscopy. At the time of endoscopic examination, we intubated the stomach and the descending part of the duodenum without inflation by air, and 20 mL of intraluminal gas samples of both sites was collected through the biopsy channel. Intraluminal H2 concentrations were measured by gas chromatography. Results. Intragastric and intraduodenal H2 gas was detected in 566 (87.5%) and 524 (81.0%) patients, respectively. The mean values of intragastric and intraduodenal H2 gas were 8.5 ± 15.9 and 13.2 ± 58.0 ppm, respectively. The intraduodenal H2 level was increased with the progression of atrophic gastritis, whereas the intragastric H2 level was the highest in patients without atrophic gastritis. Conclusions. The intraduodenal hydrogen levels were increased with the progression of atrophic gastritis. It is likely that the influence of hypochlorhydria on bacterial overgrowth in the proximal small intestine is more pronounced, compared to that in the stomach

    レゾルシル酸ラクトンLL-Z1640-2の成人T細胞白血病/リンパ腫に対する治療効果

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    Adult T-cell leukaemia/lymphoma (ATL) remains incurable. The NF-κB and interferon regulatory factor 4 (IRF4) signalling pathways are among the critical survival pathways for the progression of ATL. TGF-β-activated kinase 1 (TAK1), an IκB kinase-activating kinase, triggers the activation of NF-κB. The resorcylic acid lactone LL-Z1640-2 is a potent irreversible inhibitor of TAK1/extracellular signal-regulated kinase 2 (ERK2). We herein examined the therapeutic efficacy of LL-Z1640-2 against ATL. LL-Z1640-2 effectively suppressed the in vivo growth of ATL cells. It induced in vitro apoptosis and inhibited the nuclear translocation of p65/RelA in ATL cells. The knockdown of IRF4 strongly induced ATL cell death while downregulating MYC. LL-Z1640-2 as well as the NF-κB inhibitor BAY11-7082 decreased the expression of IRF4 and MYC at the protein and mRNA levels, indicating the suppression of the NF-κB-IRF4-MYC axis. The treatment with LL-Z1640-2 also mitigated the phosphorylation of p38 MAPK along with the expression of CC chemokine receptor 4. Furthermore, the inhibition of STAT3/5 potentiated the cytotoxic activity of LL-Z1640-2 against IL-2-responsive ATL cells in the presence of IL-2. Therefore, LL-Z1640-2 appears to be an effective treatment for ATL. Further studies are needed to develop more potent compounds that retain the active motifs of LL-Z1640-2

    A case of placenta percreta with massive hemorrhage during cesarean section

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    We describe a case of a 39-year-old woman diagnosed with placenta percreta complicated by massive hemorrhage during a cesarean section. At 27 weeks of gestation, she underwent an emergency cesarean section under general anesthesia for vaginal bleeding and an intrauterine infection. Soon after delivery, a massive hemorrhage was encountered while attempting to separate the placenta percreta from the bladder wall. Although total abdominal hysterectomy and partial cystectomy were performed, massive hemorrhaging persisted. Bleeding was finally controlled following bilateral internal iliac artery embolization. We used a cell salvage device and a rapid infuser for hemodynamics stabilization. Total blood loss was 47,000 mL, and anesthesia time was 12 h and 47 min. The patient was discharged on the 32nd postoperative day without major complications. Placenta accreta can be associated with life-threatening hemorrhage and it is vital to plan accordingly preoperatively

    Unexpected effects of azole transporter inhibitors on antifungal susceptibility in Candida glabrata and other pathogenic Candida species

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    The pathogenic fungus Candida glabrata is often resistant to azole antifungal agents. Drug efflux through azole transporters, such as Cdr1 and Cdr2, is a key mechanism of azole resistance and these genes are under the control of the transcription factor Pdr1. Recently, the monoamine oxidase A (MAO-A) inhibitor clorgyline was shown to inhibit the azole efflux pumps, leading to increased azole susceptibility in C. glabrata. In the present study, we have evaluated the effects of clorgyline on susceptibility of C. glabrata to not only azoles, but also to micafungin and amphotericin B, using wild-type and several mutant strains. The addition of clorgyline to the culture media increased fluconazole susceptibility of a C. glabrata wild-type strain, whereas micafungin and amphotericin B susceptibilities were markedly decreased. These phenomena were also observed in other medically important Candida species, including Candida albicans, Candida parapsilosis, Candida tropicalis, and Candida krusei. Expression levels of CDR1, CDR2 and PDR1 mRNAs and an amount of Cdr1 protein in the C. glabrata wild-type strain were highly increased in response to the treatment with clorgyline. However, loss of Cdr1, Cdr2, Pdr1, and a putative clorgyline target (Fms1), which is an ortholog of human MAO-A, or overexpression of CDR1 did not affect the decreased susceptibility to micafungin and amphotericin B in the presence of clorgyline. The presence of other azole efflux pump inhibitors including milbemycin A4 oxime and carbonyl cyanide 3-chlorophenylhydrazone also decreased micafungin susceptibility in C. glabrata wild-type, Δcdr1, Δcdr2, and Δpdr1 strains. These findings suggest that azole efflux pump inhibitors increase azole susceptibility but concurrently induce decreased susceptibility to other classes of antifungals independent of azole transporter functions
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