59 research outputs found
The , , and other compact states
We study the spectrum and rearrangement decays of S-wave
tetraquark states in a simplified quark model. The masses and widths are
estimated by assuming that the is the lower
tetraquark. Comparing our results with experimental
measurements, we find that the recently observed by LHCb can be
assigned as the lowest tetraquark state and the
could be the second lowest tetraquark.
Predictions of ratios between partial widths for the involved tetraquarks are
given. We call for searches for more tetraquarks with
, , and
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data
The Efficacy of Pretreatment F-FDG PET-CT-Based Deep Learning Network Structure to Predict Survival in Nasopharyngeal Carcinoma
Background: Previous studies have shown that the 5-year survival rates of patients with nasopharyngeal carcinoma (NPC) were still not ideal despite great improvement in NPC treatments. To achieve individualized treatment of NPC, we have been looking for novel models to predict the prognosis of patients with NPC. The objective of this study was to use a novel deep learning network structural model to predict the prognosis of patients with NPC and to compare it with the traditional PET-CT model combining metabolic parameters and clinical factors. Methods: A total of 173 patients were admitted to 2 institutions between July 2014 and April 2020 for the retrospective study; each received a PET-CT scan before treatment. The least absolute shrinkage and selection operator (LASSO) was employed to select some features, including SUVpeak-P, T3, age, stage II, MTV-P, N1, stage III and pathological type, which were associated with overall survival (OS) of patients. We constructed 2 survival prediction models: an improved optimized adaptive multimodal task (a 3D Coordinate Attention Convolutional Autoencoder and an uncertainty-based jointly Optimizing Cox Model, CACA-UOCM for short) and a clinical model. The predictive power of these models was assessed using the Harrell Consistency Index (C index). Overall survival of patients with NPC was compared by Kaplan–Meier and Log-rank tests. Results: The results showed that CACA-UOCM model could estimate OS (C index, 0.779 for training, 0.774 for validation, and 0.819 for testing) and divide patients into low and high mortality risk groups, which were significantly associated with OS ( P  < .001). However, the C-index of the model based only on clinical variables was only 0.42. Conclusions: The deep learning network model based on 18 F-FDG PET/CT can serve as a reliable and powerful predictive tool for NPC and provide therapeutic strategies for individual treatment
Experimental Study on Transient Startup Characteristics of a Super Low Specific Speed Centrifugal Pump
Stimulation of BDNF expression by transplanted OPCs.
<p>(A, C) BDNF<sup>+</sup> cells were visualized by immunolabeling in the cortex and SGZ 7 days after transplantation. (B, D) The number of BDNF<sup>+</sup> cells was increased in HI animals (HI+PBS) compared to sham-operated controls; injection of OPCs (HI+OPC) potentiated this effect. Data are expressed as mean ± SD. *P < 0.05, HI group vs. sham controls; <sup>#</sup>P < 0.05, <sup>##</sup>P < 0.01 between HI+PBS and HI+OPC groups; n = 6–8 animals per group. Scale bar = 50 μm.</p
Migration of transplanted OPCs in the brain.
<p>GFP<sup>+</sup> OPCs in the brains of rats subjected to sham operation or HI, then injected with OPCs. Animals were sacrificed 14 days and 6 weeks after transplantation, and coronal sections were immunostained for GFP and counterstained with DAPI. (A, C) GFP-expressing tranplanted OPCs in lateral ventricles and SVZ 14 days after transplantation. (B, D, F) GFP<sup>+</sup> cells were observed in the regions surrounding the ventricles 6 weeks after transplantation. GFP<sup>+</sup> OPCs were detected in (E, G) the cortex ispilateral to the side of injury and in the septofimbrial nucleus of the hippocampus and (H, I) in the SGZ of the hippocampus. Scale bar = 50 μm.</p
OPC transplantation promotes NSC proliferation in the SVZ and the DG of the hippocampus following HI.
<p>(A, C) Proliferating NSCs (white arrows) were visualized by double immunolabeling with antibodies against BrdU (red) and Nestin (green). (B, D) The number of BrdU<sup>+</sup>/Nestin<sup>+</sup> proliferating NSC increased in HI animals (HI+PBS) compared to sham-operated controls; injection of OPCs (HI+OPC) potentiated this effect. Data are expressed as mean ± SD. *P < 0.05, **P < 0.01, HI group vs. sham controls; <sup>#</sup>P < 0.05, <sup>##</sup>P < 0.01 between HI+PBS and HI+OPC groups; n = 6–8 animals per group. Scale bar = 50μm.</p
Stimulation of Bcl-2 expression by transplanted OPCs.
<p>(A, C) Bcl-2<sup>+</sup> cells were visualized by immunolabeling in the cortex and SGZ 7 days after transplantation. (B, D) The number of Bcl-2<sup>+</sup> cells increased, but not significantly, in HI animals (HI+PBS) compared to sham-operated controls; OPC injection (HI+OPC) potentiated this effect. Data are expressed as mean ± SD. <sup>#</sup>P < 0.05, <sup>##</sup>P < 0.01 between HI+PBS and HI+OPC groups; n = 6–8 animals per group. Scale bar = 50 μm.</p
OPC transplantation improves spatial learning and memory deficits induced by HI.
<p>Animals were tested in the Morris water maze 36–40 days after transplantation. (A) Number of platform crossings; (B) percentage of time spent in the platform quadrant; (C) escape latency; (D) percentage of distance travelled in the platform quadrant. HI induced cognitive deficits in animals (HI+PBS), including longer escape latency, fewer platform crossings, and decreased time spent and distance traveled in the platform quadrant compared to sham animals; OPC transplantation partly reversed these effects. Data are expressed as mean ± SD. *P <0.05, **P < 0.01, HI group vs. sham controls. <sup>#</sup>P < 0.05, <sup>##</sup>P < 0.01 between HI+PBS and HI+OPC groups; n = 17 animals per group.</p
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