Single magnetic atoms absorbed on an atomically thin layer represent the ultimate limit of bit miniaturization for data storage. To approach the limit, a critical step is to find an appropriate ...material system with high chemical stability and large magnetic anisotropic energy. Here, on the basis of first-principles calculations and the spin-orbit coupling theory, it is elucidated that the transition-metal Mn and Fe atoms absorbed on disulfur vacancies of MoS2 monolayers are very promising candidates. It is analysed that these absorption systems are of not only high chemical stabilities but also much enhanced magnetic anisotropies and particularly the easy magnetization axis is changed from the in-plane one for Mn to the out-of-plane one for Fe by a symmetry-lowering Jahn-Teller distortion. The results point out a promising direction to achieve the ultimate goal of single adatomic magnets with utilizing the defective atomically thin layers.
Determining the cause for pulmonary hypertension is difficult in many patients. Pulmonary arterial hypertension (PAH) is differentiated from pulmonary venous hypertension (PVH) by a wedge pressure ...(PWP)>15 mm Hg in PVH. Patients undergoing right heart catheterization for evaluation of pulmonary hypertension may be dehydrated and have reduced intravascular volume, potentially leading to a falsely low measurement of PWP and an erroneous diagnosis of PAH. We hypothesized that a fluid challenge during right heart catheterization would identify occult pulmonary venous hypertension (OPVH).
We reviewed the results of patients undergoing fluid challenge in our pulmonary hypertension database from 2004 to 2011. Baseline hemodynamics were obtained and repeated after infusion of 0.5 L of normal saline for 5 to 10 minutes. Patients were categorized as OPVH if PWP increased to >15 mm Hg after fluid challenge. Baseline hemodynamics in 207 patients met criteria for PAH. After fluid challenge, 46 patients (22.2%) developed a PWP>15 mm Hg and were reclassified as OPVH. Patients with OPVH had a greater increase in PWP compared with patients with PAH, P<0.001, and their demographics and comorbid illnesses were similar to patients with PVH. There were no adverse events related to fluid challenge.
Fluid challenge at the time of right heart catheterization is easily performed, safe, and identifies a large group of patients diagnosed initially with PAH, but for whom OPVH contributes to pulmonary hypertension. These results have implications for therapeutic trials in PAH and support the routine use of fluid challenge during right heart catheterization in patients with risk factors for PVH.
A self-assembly approach is used to fabricate a graphene-coated mesoporous carbon/sulfur composite. The graphene coating on the surface of the composite is 15–20nm in thickness, and sulfur is well ...dispersed in the pores of mesoporous carbon and the interfaces between the mesoporous carbon and graphene sheets after a heat treatment at 300°C. The graphene coating helps to increase the sulfur content and retard the diffusion of polysulfides. The galvanostatic charge–discharge tests show that the graphene-coated sulfur electrode presents good cycling stability. Specific discharge capacities up to 650mAhg−1 over 100 cycles at 0.1C is achieved with enhanced coulombic efficiency, representing a promising cathode material for lithium–sulfur battery.
In this paper, both time-averaged and fluctuating behaviors of granular solids in a two-dimensional spouted bed (2DSB) were investigated by particle image velocimetry (PIV). A self-developed ...algorithm for the high-gradient granular flow field was employed to measure particle velocity sequences together with power spectral density, mean particle velocity and granular temperature. The incoherent spout was characterized as an ‘X’ geometry marked with a periodic upwardly moving neck consisting of particle clusters. In the annulus, particles move periodically as a process of acceleration–deceleration–stagnation that has the same domain frequency as the pressure drop of 2DSB. The time-averaged downward velocities have a maximum at a certain position between the spout wall and conical wall. In the spout, the longitudinal profiles of vertical particle velocities along the axis exhibit a fast acceleration followed by a long flat peak, while the normalized lateral profiles at all bed levels tend to collapse into a third polynomial curve with an inflection point. A mushroom-like distribution of the granular temperature exists in 2DSB. The peaks of granular temperature occur not only near the spout–annulus interface, but also at the corner zone between the annulus and the fountain.
Consideration of surface (interface) energy effects on the elastic field of a solid material has applications in several modern problems in solid mechanics. The Gurtin–Murdoch continuum model M.E. ...Gurtin, A.I. Murdoch, Arch. Ration. Mech. Anal. 57 (1975) 291–323; M.E. Gurtin, J. Weissmuller, F. Larché, Philos. Mag. A 78 (1998) 1093–1109 accounting for surface energy effects is applied to analyze the elastic field of an isotropic elastic layer bonded to a rigid base. The surface properties are characterized by the residual surface tension and surface Lame constants. The general solutions of the bulk medium expressed in terms of Fourier integral transforms and Hankel integral transforms are used to formulate the two-dimensional and axisymmetric three-dimensional problems, respectively. The generalized Young–Laplace equation for a surface yields a set of non-classical boundary conditions for the current class of problems. An explicit analytical solution is presented for the elastic field of a layer. The layer solution is specialized to obtain closed-form solutions for semi-infinite domains. Selected numerical results are presented to show the influence of surface elastic constants and layer thickness on stresses and displacements.
Clinical endometritis is an important disease of dairy cattle and results in decreased reproductive performance. This disease is caused by contamination of the uterus with a broad spectrum of ...microorganisms after calving. In this study, staphylococcal isolates from the uterus of dairy cows with clinical endometritis were tested for their distribution of superantigen (SAg) genes and antimicrobial resistance. Between the 127 staphylococcal isolates collected in this study, 10 species were identified. The predominant strain identified was Staphylococcus aureus (n=53), followed by Staphylococcus saprophyticus (n=38) and Staphylococcus chromogenes (n=22). PCR analysis demonstrated that most isolates (63.0 per cent) harboured at least one SAg gene. The most commonly observed SAg gene and genotype was selj (38.6 per cent) and sec-selj-seln (24.0 per cent), respectively. Most isolates were resistant to penicillin (79.5 per cent), ampicillin (71.7 per cent), erythromycin (56.7 per cent), and tetracycline (52.0 per cent). PCR analysis demonstrated that the antimicrobial resistance determinants ermA, ermB, ermC, tetK, tetM and blaZ were detected in 0 per cent, 44.4 per cent, 51.4 per cent, 68.2 per cent, 13.6 per cent and 86.1 per cent of the erythromycin, tetracycline and β-lactam resistant isolates, respectively. There were 22 (17.3 per cent of all isolates) coagulase-negative staphylococci shown to be methicillin resistant. In the methicillin-resistant isolates, significant resistances to ampicillin, erythromycin and penicillin were observed (P<0.01). The results of this study demonstrate that staphylococci recovered from dairy cows with clinical endometritis contain an extensive and complex prevalence of SAg genes. Significant resistances to antibiotics were also seen, highlighting the need for the rational appliance of antibiotics in veterinary medicine.
Radiofrequency coblation (RFC) is a relatively new device that has been used in several transoral procedures. Currently, clinical data on its use for excising lingual thyroglossal duct cyst (LTGDC) ...are lacking. Herein, we conducted this retrospective case series to explore the feasibility and efficacy of RFC-assisted transoral surgery (RFC-TOS) in excising LTGDC. A total of 12 LTGDC patients between 2013 and 2020 were retrospectively studied. The cysts of these patients were all fully removed along the boundary to the depth of the hyoid using RFC wands. All surgeries were completed within 30 minutes. Only one patient had an intraoperative blood loss of more than 10 ml. All patients started oral feeding on the day of operation. The mean postoperative hospital stay was only 3.3 days (range 1-8 days). No surgical-related short-term and long-term complications were observed. One patient was lost to follow up, and no recurrences occurred during a mean follow-up period of 52.7 months among the other 11 patients. Therefore, we believe that RFC is a reliable tool in transoral operation for treating LTGDC. LTGDC patients who underwent RFC-TOS showed quick recovery, low risks of complications, and excellent clinical and functional outcomes.
An ion-implantation method was used to prepare V-ion-implanted P25 TiO2 photocatalysts. Their photocatalytic activity for the degradation of formic acid under visible light irradiation (lambda>450 ...nm) was investigated. Upon implantation of V ions into the lattice of P25 TiO2, the photoactivity was remarkably enhanced. HRTEM images showed that the implanted V ions existed in the form of VO2(T) in the lattice of P25 TiO2. The intensity of photoluminescence (PL) spectra of V-ion-implanted P25 TiO2 decreased with the increase of the amount of implanted V ions, indicating the decrease of electron-hole pair recombination. It was also observed that the lower the PL intensity of V-ion-implanted P25 TiO2, the higher the photoactivity.
Summary
Background
Pioneering effort has been made to facilitate the recognition of pathology in malignancies based on whole‐slide images (WSIs) through deep learning approaches. It remains unclear ...whether we can accurately detect and locate basal cell carcinoma (BCC) using smartphone‐captured images.
Objectives
To develop deep neural network frameworks for accurate BCC recognition and segmentation based on smartphone‐captured microscopic ocular images (MOIs).
Methods
We collected a total of 8046 MOIs, 6610 of which had binary classification labels and the other 1436 had pixelwise annotations. Meanwhile, 128 WSIs were collected for comparison. Two deep learning frameworks were created. The ‘cascade’ framework had a classification model for identifying hard cases (images with low prediction confidence) and a segmentation model for further in‐depth analysis of the hard cases. The ‘segmentation’ framework directly segmented and classified all images. Sensitivity, specificity and area under the curve (AUC) were used to evaluate the overall performance of BCC recognition.
Results
The MOI‐ and WSI‐based models achieved comparable AUCs around 0·95. The ‘cascade’ framework achieved 0·93 sensitivity and 0·91 specificity. The ‘segmentation’ framework was more accurate but required more computational resources, achieving 0·97 sensitivity, 0·94 specificity and 0·987 AUC. The runtime of the ‘segmentation’ framework was 15·3 ± 3·9 s per image, whereas the ‘cascade’ framework took 4·1 ± 1·4 s. Additionally, the ‘segmentation’ framework achieved 0·863 mean intersection over union.
Conclusions
Based on the accessible MOIs via smartphone photography, we developed two deep learning frameworks for recognizing BCC pathology with high sensitivity and specificity. This work opens a new avenue for automatic BCC diagnosis in different clinical scenarios.
What's already known about this topic?
The diagnosis of basal cell carcinoma (BCC) is labour intensive due to the large number of images to be examined, especially when consecutive slide reading is needed in Mohs surgery.
Deep learning approaches have demonstrated promising results on pathological image‐related diagnostic tasks.
Previous studies have focused on whole‐slide images (WSIs) and leveraged classification on image patches for detecting and localizing breast cancer metastases.
What does this study add?
Instead of WSIs, microscopic ocular images (MOIs) photographed from microscope eyepieces using smartphone cameras were used to develop neural network models for recognizing BCC automatically.
The MOI‐ and WSI‐based models achieved comparable areas under the curve around 0·95.
Two deep learning frameworks for recognizing BCC pathology were developed with high sensitivity and specificity.
Recognizing BCC through a smartphone could be considered a future clinical choice.
Linked Comment: Lee and Soyer. Br J Dermatol 2020; 182:540–541.
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