Treatment with effective antibiotics is one important strategy for syphilis control in China. This study aimed to evaluate the prevalence of azithromycin resistance to T. pallidum in China. A ...cross-sectional study was conducted among 391 patients with early syphilis recruited from STD clinics in eight cities during October 2008 and October 2011. The swabs were obtained from the moist lesions of the participating patients. A touchdown/nested PCR of the 23S ribosomal RNA (rRNA) gene was performed on DNA samples extracted from these specimens. The presence or absence of the A2058G point mutation, conferring resistance to azithromycin, was determined by restriction enzyme digestion analysis of the PCR amplicon by MboII. Two hundred and eleven patients with primary or secondary syphilis were found to have T. pallidum DNA in their moist lesions by PCR assays. The A2058G mutation was present in 91.9% (194/211, 95% CI, 87.2–95.1%) of these patients, with no significant differences noted between patients from the eastern part (93.8%), southern part (88.6%) and northern part (95.2%) of China (v2 = 2.303, p 0.316). Compared with patients who had not taken macrolides in previous years before study entry, the patients who had taken the antibiotics had a significantly higher prevalence of azithromycin resistance (97.0% vs. 62.5%), with an odds ratio of 19.65 (95% CI, 5.77–66.93). It can be concluded that prevalence of azithromycin resistance is substantial in China and consequently that the macrolides should not be used as a treatment option for early or incubating syphilis in China.
Resting-state functional MR imaging has been used for motor mapping in presurgical planning but never used intraoperatively. This study aimed to investigate the feasibility of applying intraoperative ...resting-state functional MR imaging for the safe resection of gliomas using real-time motor cortex mapping during an operation.
Using interventional MR imaging, we conducted preoperative and intraoperative resting-state intrinsic functional connectivity analyses of the motor cortex in 30 patients with brain tumors. Factors that may influence intraoperative imaging quality, including anesthesia type (general or awake anesthesia) and tumor cavity (filled with normal saline or not), were studied to investigate image quality. Additionally, direct cortical stimulation was used to validate the accuracy of intraoperative resting-state fMRI in mapping the motor cortex.
Preoperative and intraoperative resting-state fMRI scans were acquired for all patients. Fourteen patients who successfully completed both sufficient intraoperative resting-state fMRI and direct cortical stimulation were used for further analysis of sensitivity and specificity. Compared with those subjected to direct cortical stimulation, the sensitivity and specificity of intraoperative resting-state fMRI in localizing the motor area were 61.7% and 93.7%, respectively. The image quality of intraoperative resting-state fMRI was better when the tumor cavity was filled with normal saline (
= .049). However, no significant difference between the anesthesia types was observed (
= .102).
This study demonstrates the feasibility of using intraoperative resting-state fMRI for real-time localization of functional areas during a neurologic operation. The findings suggest that using intraoperative resting-state fMRI can avoid the risk of intraoperative seizures due to direct cortical stimulation and may provide neurosurgeons with valuable information to facilitate the safe resection of gliomas.
Abstract
We conduct an all-sky search for continuous gravitational waves in the LIGO O2 data from the Hanford and Livingston detectors. We search for nearly monochromatic signals with frequency ...20.0 Hz ≤
f
≤ 585.15 Hz and spin-down
Hz s
−1
. We deploy the search on the Einstein@Home volunteer-computing project and follow-up the waveforms associated with the most significant results with eight further search stages, reaching the best sensitivity ever achieved by an all-sky survey up to 500 Hz. Six of the inspected waveforms pass all the stages but they are all associated with hardware injections, which are fake signals simulated at the LIGO detector for validation purposes. We recover all these fake signals with consistent parameters. No other waveform survives, so we find no evidence of a continuous gravitational wave signal at the detectability level of our search. We constrain the
h
0
amplitude of continuous gravitational waves at the detector as a function of the signal frequency, in half-Hz bins. The most constraining upper limit at 163.0 Hz is
h
0
= 1.3 × 10
−25
, at the 90% confidence level. Our results exclude neutron stars rotating faster than 5 ms with equatorial ellipticities larger than 10
−7
closer than 100 pc. These are deformations that neutron star crusts could easily support, according to some models.
Topological superconductivity is one of most fascinating properties of topological quantum matters that was theoretically proposed and can support Majorana Fermions at the edge state. ...Superconductivity was previously realized in a Cu-intercalated Bi2Se3 topological compound or a Bi2Te3 topological compound at high pressure. Here we report the discovery of superconductivity in the topological compound Sb2Te3 when pressure was applied. The crystal structure analysis results reveal that superconductivity at a low-pressure range occurs at the ambient phase. The Hall coefficient measurements indicate the change of p-type carriers at a low-pressure range within the ambient phase, into n-type at higher pressures, showing intimate relation to superconducting transition temperature. The first principle calculations based on experimental measurements of the crystal lattice show that Sb2Te3 retains its Dirac surface states within the low-pressure ambient phase where superconductivity was observed, which indicates a strong relationship between superconductivity and topology nature.
Chikungunya virus (CHIKV) is a mosquito-borne alphavirus known to cause epidemics resulting in predominantly symptomatic infections, which in rare cases cause long term debilitating arthritis and ...arthralgia. Significant progress has been made in understanding the roles of canonical RNA sensing pathways in the host recognition of CHIKV; however, less is known regarding antagonism of CHIKV by cytosolic DNA sensing pathways like that of cyclic GMP-AMP synthase (cGAS) and Stimulator of Interferon Genes (STING). With the use of cGAS or STING null cells we demonstrate that the pathway restricts CHIKV replication in fibroblasts and immune cells. We show that DNA accumulates in the cytoplasm of infected cells and that CHIKV blocks DNA dependent IFN-β transcription. This antagonism of DNA sensing is via an early autophagy-mediated degradation of cGAS and expression of the CHIKV capsid protein is sufficient to induce cGAS degradation. Furthermore, we identify an interaction of CHIKV nsP1 with STING and map the interaction to 23 residues in the cytosolic loop of the adaptor protein. This interaction stabilizes the viral protein and increases the level of palmitoylated nsP1 in cells. Together, this work supports previous publications highlighting the relevance of the cGAS-STING pathway in the early detection of (+)ssRNA viruses and provides direct evidence that CHIKV interacts with and antagonizes cGAS-STING signaling.
Current microlensing surveys are sensitive to free-floating planets down to Earth-mass objects. All published microlensing events attributed to unbound planets were identified based on their short ...timescale (below two days), but lacked an angular Einstein radius measurement (and hence lacked a significant constraint on the lens mass). Here, we present the discovery of a Neptune-mass free-floating planet candidate in the ultrashort (tE = 0.320 0.003 days) microlensing event OGLE-2016-BLG-1540. The event exhibited strong finite-source effects, which allowed us to measure its angular Einstein radius of θE = 9.2 0.5 as. There remains, however, a degeneracy between the lens mass and distance. The combination of the source proper motion and source-lens relative proper motion measurements favors a Neptune-mass lens located in the Galactic disk. However, we cannot rule out that the lens is a Saturn-mass object belonging to the bulge population. We exclude stellar companions up to ∼15 au.
ZnO thin films were prepared in Ar and Ar+H2 atmospheres by rf magnetron sputtering, and then they were annealed in vacuum and Ar+H2 atmosphere, respectively. The structure and optical–electrical ...properties of the films were investigated by X-ray diffraction, transmittance spectra, and resistivity measurement, and their dependences on deposition atmosphere, annealing treatment, and aging were studied. The results showed that adding H2 in deposition atmosphere improved the crystallinity of the films, decreased lattice constant, increased band gap, decreased the resistivity by the order of 104Ωcm, but exhibited poor conductive stability with aging. After Ar+H2 and vacuum annealing, crystallinity of the films deposited in Ar and Ar+H2 was further improved; their resistivity was decreased by the order of 105 and 101Ωcm, respectively, and exhibited high conductive stability with aging. We suggest that the formed main defect is VO and Hi when H2 is introduced during deposition, which decreases the resistivity but cannot improve the conductive stability; hydrogen would remove negatively charged oxygen species near grain boundaries during Ar+H2 annealing to decrease the resistivity, and grain boundaries are passivated by formation of a number of VO–H complex (HO) to improve the conductive stability at the same time. Under vacuum annealing, the hydrogen that is introduced non-intentionally from deposition chamber maybe plays an important role; it exists as HO in the films to improve the conductive stability of the films.
We have used the Linac Coherent Light Source to generate solid-density aluminum plasmas at temperatures of up to 180 eV. By varying the photon energy of the x rays that both create and probe the ...plasma, and observing the K-α fluorescence, we can directly measure the position of the K edge of the highly charged ions within the system. The results are found to disagree with the predictions of the extensively used Stewart-Pyatt model, but are consistent with the earlier model of Ecker and Kröll, which predicts significantly greater depression of the ionization potential.
The emergence of the H7N9 influenza virus in humans in Eastern China has raised concerns that a new influenza pandemic could occur. Here, we used a ferret model to evaluate the infectivity and ...transmissibility of A/Shanghai/2/2013 (SH2), a human H7N9 virus isolate. This virus replicated in the upper and lower respiratory tracts of the ferrets and was shed at high titers for 6 to 7 days, with ferrets showing relatively mild clinical signs. SH2 was efficiently transmitted between ferrets via direct contact, but less efficiently by airborne exposure. Pigs were productively infected by SH2 and shed virus for 6 days but were unable to transmit the virus to naïve pigs or ferrets. Under appropriate conditions, human-to-human transmission of the H7N9 virus may be possible.
Recent developments in the technology of van der Waals heterostructures made from two-dimensional atomic crystals have already led to the observation of new physical phenomena, such as the ...metal-insulator transition and Coulomb drag, and to the realization of functional devices, such as tunnel diodes, tunnel transistors and photovoltaic sensors. An unprecedented degree of control of the electronic properties is available not only by means of the selection of materials in the stack, but also through the additional fine-tuning achievable by adjusting the built-in strain and relative orientation of the component layers. Here we demonstrate how careful alignment of the crystallographic orientation of two graphene electrodes separated by a layer of hexagonal boron nitride in a transistor device can achieve resonant tunnelling with conservation of electron energy, momentum and, potentially, chirality. We show how the resonance peak and negative differential conductance in the device characteristics induce a tunable radiofrequency oscillatory current that has potential for future high-frequency technology.
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