116 research outputs found
A rapid method for flow pattern, mixing time estimation and turbulent dissipation rates in turbulent stirred mixers based on 2-D network-of-zones (NoZ) model
A rapid non-iterative method for estimating flow patterns in stirred vessels in fully turbulent regime was defined and evaluated starting from limited known data near the core regions based on the 2-D network-of-zone (NoZ) model. Flow pattern induced by impeller of arbitrary diameter could be generated non-iteratively from known NoZ data with impeller of same type but another diameter, before mixing time was estimated within minutes on a standard PC. Case studies on six different impeller diameter and types representing typical radial flow impellers and axial flow impellers respectively was presented, errors of mixing time predicted in which were all within a maximum of ±33% compared to mixing time predicted via experimental correlation. A rapid method for estimating turbulent dissipation rate profiles were also introduced and evaluated quantitatively
Live poultry trading drives China's H7N9 viral evolution and geographical network propagation
The on-going reassortment, human-adapted mutations, and spillover events of novel A(H7N9) avian influenza viruses pose a significant challenge to public health in China and globally. However, our understanding of the factors that disseminate the viruses and drive their geographic distributions is limited. We applied phylogenic analysis to examine the inter-subtype interactions between H7N9 viruses and the closest H9N2 lineages in China during 2010–2014. We reconstructed and compared the inter-provincial live poultry trading and viral propagation network via phylogeographic approach and network similarity technique. The substitution rates of the isolated viruses in live poultry markets and the characteristics of localized viral evolution were also evaluated. We discovered that viral propagation was geographically-structured and followed the live poultry trading network in China, with distinct north-to-east paths of spread and circular transmission between eastern and southern regions. The epicenter of H7N9 has moved from the Shanghai–Zhejiang region to Guangdong Province was also identified. Besides, higher substitution rate was observed among isolates sampled from live poultry markets, especially for those H7N9 viruses. Live poultry trading in China may have driven the network-structured expansion of the novel H7N9 viruses. From this perspective, long-distance geographic expansion of H7N9 were dominated by live poultry movements, while at local scales, diffusion was facilitated by live poultry markets with highly-evolved viruses
Rydberg-atom-based single-photon detection for haloscope axion searches
We propose a Rydberg-atom-based single-photon detector for signal readout in
dark matter haloscope experiments between 40 eV and 200 eV (10
GHz and 50 GHz). At these frequencies, standard haloscope readout using linear
amplifiers is limited by quantum measurement noise, which can be avoided by
using a single-photon detector. Our single-photon detection scheme can offer
scan rate enhancements up to a factor of over traditional linear
amplifier readout, and is compatible with many different haloscope cavities. We
identify multiple haloscope designs that could use our Rydberg-atom-based
single-photon detector to search for QCD axions with masses above 40 eV
(10 GHz), currently a minimally explored parameter space.Comment: 15 pages, 8 figure
Image-guided interstitial brachytherapy for recurrent cervical cancer after radiotherapy: A single institution experience
PurposeThe aim of this study is to evaluate the efficacy and toxicity of image-guided high-dose rate (HDR) interstitial brachytherapy (ISBT) for the reirradiation of cervical cancer within a previously irradiated area.Methods and materialsTwenty-three consecutive patients with cervical cancer were reirradiated with curative intent using brachytherapy (BT) with or without external beam irradiation. The median biologically equivalent dose in 2-Gy fractions (EQD2) for reirradiation was 64.0 Gy (range: 31.3–95.1 Gy), and the median cumulative EQD2 (for primary treatment and reirradiation) was 152.4 Gy (range: 97.8–200.9 Gy). The average clinical target volume was 82.9 cm3 (range: 26.9–208.3 cm3), and the median treatment-free interval (TFI) was 13 months (range: 3–93 months).ResultsThe median follow-up time was 19 months (range: 2–59 months). The complete response rate after reirradiation was 56.5%. The 1-, 2- 3-, and 4-year post-relapse survival (PRS) rates were 65.2%, 43.5%, 33.8%, and 27.1%, respectively. The median reirradiation EQD2 D2cc of rectum and bladder was 39.5 Gy (range = 14.6–96.2 Gy) and 52.1 Gy (range = 29.1–114.2 Gy). The median cumulative EQD2 D2cc of rectum and bladder was 115.0 Gy (range = 84.4–189.3 Gy) and 130.5 Gy (range = 95.5–173.5 Gy). During follow-up, nine (39.1%) patients had experienced grade 3 or 4 late toxicities. Grade ≥3 rectal toxicity occurred in three patients (13.0%). Grade ≥3 urinary toxicity occurred in five patients (21.7%). One patient (4.3%) had both grade ≥3 urinary and rectal toxicity. Tumor volume, TFI, tumor invasion organ number, and local control were significant prognostic factors adversely affecting OS.ConclusionsFor recurrent cervical cancer after radiotherapy, reirradiation of HDR-ISBT is feasible, even if the local tumor invasion is large, with a good chance of survival and acceptable side effects
Fatty acid metabolites of Dendrobium nobile were positively correlated with representative endophytic fungi at altitude
IntroductionAltitude, as a comprehensive ecological factor, regulates the growth and development of plants and microbial distribution. Dendrobium nobile (D. nobile) planted in habitats at different elevations in Chishui city, also shows metabolic differences and endophytes diversity. What is the triangular relationship between altitude, endophytes, and metabolites?MethodsIn this study, the diversity and species of endophytic fungi were tested by ITS sequencing and metabolic differences in plants were tested by UPLC–ESI–MS/MS. Elevation regulated the colonization of plant endophytic fungal species and fatty acid metabolites in D. nobile.ResultsThe results indicate that and high altitude was better for the accumulation of fatty acid metabolites. Therefore, the high-altitude characteristic endophytic floras were screened, and the correlation with fatty acid metabolites of plants was built. The colonization of T. rubrigenum, P. Incertae sedis unclassified, Phoma. cf. nebulosa JZG 2008 and Basidiomycota unclassified showed a significantly positive correlation with fatty acid metabolites, especially 18-carbon-chain fatty acids, such as (6Z,9Z,12Z)-octadeca-6,9,12-trienoic acid, 3,7,11,15-tetramethyl-12-oxohexadeca-2,4-dienoic acid and Octadec-9-en-12-ynoic acid. What is more fascinating is these fatty acids are the essential substrates of plant hormones.DiscussionConsequently, it was speculated that the D. nobile- colonizing endophytic fungi stimulated or upregulated the synthesis of fatty acid metabolites and even some plant hormones, thus affecting the metabolism and development of D. nobile
Postoperative hypothalamic-pituitary dysfunction and long-term hormone replacement in patients with childhood-onset craniopharyngioma
ObjectiveHypothalamic-pituitary axis dysfunction is a common complication in post-operative craniopharyngioma(CP) patients, and it greatly impacts the long-term quality of life of such patients. To better understand the effects of postoperative hypothalamic-pituitary dysfunction and long-term hormone replacement therapy in patients with childhood CP, we assessed approximately 200 patients with childhood-onset CP postoperatively.MethodsClinical details of patients with childhood-onset CP who underwent sellar tumor resection in Beijing Children’s Hospital and Beijing Tiantan Hospital from 2018 to 2019 were retrieved retrospectively. The participants were followed up to assess the effects of post-operative long-term hormone replacement therapy and assess the tumor recurrence rate.ResultsThe median age of admission was 8.1 (1.8, 14.3) years. Headache (45.5%), visual impairment (39.5%), and nausea (33.0%) were the most common clinical manifestations. ACP accounted for 95% of all CP cases. The incidence of central adrenal insufficiency and central hypothyroidism within the first week after surgery was 56.2% and 70.3%, respectively. At the same time 85.5% of the patients required at least one dose of desmopressin to control urine output. Total survival and tumor recurrence rates were 98.6% and 26.1%, respectively, with a median follow-up time of 29.7 (19.0, 40.3) months. During the follow-up period, 28.1% patients met the diagnostic criteria for short stature, while 54.4% fit the criteria for obesity. In addition, 94.4% of the patients were taking at least one kind of hormone substitution, and 74.7% were taking three or more. The prevalence of levothyroxine, glucocorticoid, desmopressin, and growth hormone replacement therapy was 87.3%, 77.5%, 78.9% and 31.0%, respectively. The proportion of patients treated with the substitutive combination of levothyroxine, hydrocortisone, and desmopressin was 54.9%.ConclusionThis study is a large-sample systematic postoperative endocrine function evaluation of patients with childhood-onset CP. Due to the high prevalence of post-operative hypothalamic-pituitary dysfunction, patients with CP usually require long-term multiple hormone substitution therapy. Individualized management and accurate hormone replacement dosage for postoperative childhood-onset CP patients are of great importance
New Results from HAYSTAC's Phase II Operation with a Squeezed State Receiver
A search for dark matter axions with masses has been
performed using the HAYSTAC experiment's squeezed state receiver to achieve
sub-quantum limited noise. This report includes details of the design and
operation of the experiment previously used to search for axions in the mass
ranges and (GHz) and
GHz) as well as upgrades to facilitate an extended search at
higher masses. These upgrades include improvements to the data acquisition
routine which have reduced the effective dead time by a factor of 5, allowing
for the new region to be scanned 1.6 times faster with comparable
sensitivity. No statistically significant evidence of an axion signal is found
in the range (GHz), leading to an
aggregate upper limit exclusion at the level on the axion-photon
coupling of .Comment: 20 pages, 16 figure
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