Colorimetric sensing of copper(II) based on catalytic etching of gold nanoparticles

Based on the catalytic etching of gold nanoparticles (AuNPs), a label-free colorimetric probe was developed for the detection of Cu2+ in aqueous solutions. AuNPs were first stabilized by hexadecyltrimethylammonium bromide in NH3-NH4Cl (0.6 M/0.1 M) solutions. Then thiosulfate (S2O32-) ions were introduced and AuNPs were gradually dissolved by dissolved oxygen. With the further addition of Cu2+, Cu(NH3)(4)(2+) oxidized AuNPs to produce Au(S2O3)(2)(3-) and Cu(S2O3)(3)(5-), while the later was oxidized to Cu(NH3)(4)(2+) again by dissolved oxygen. The dissolving rate of AuNPs was thereby remarkably promoted and Cu2+ acted as the catalyst. The process went on due to the sufficient supply of dissolved oxygen and AuNPs were rapidly etched. Meanwhile, a visible color change from red to colorless was observed. Subsequent tests confirmed such a non-aggregation-based method as a sensitive (LOD= 5.0 nM or 032 ppb) and selective (at least 100-fold over other metal ions except for Pb2+ and Mn2+) way for the detection of Cu2+ (linear range, 10-80 nM). Moreover, our results show that the color change induced by 40 nM Cu2+ can be easily observed by naked eyes, which is particularly applicable to fast on-site investigations. (C) 2013 Elsevier B.V. All rights reserved.Based on the catalytic etching of gold nanoparticles (AuNPs), a label-free colorimetric probe was developed for the detection of Cu2+ in aqueous solutions. AuNPs were first stabilized by hexadecyltrimethylammonium bromide in NH3-NH4Cl (0.6 M/0.1 M) solutions. Then thiosulfate (S2O32-) ions were introduced and AuNPs were gradually dissolved by dissolved oxygen. With the further addition of Cu2+, Cu(NH3)(4)(2+) oxidized AuNPs to produce Au(S2O3)(2)(3-) and Cu(S2O3)(3)(5-), while the later was oxidized to Cu(NH3)(4)(2+) again by dissolved oxygen. The dissolving rate of AuNPs was thereby remarkably promoted and Cu2+ acted as the catalyst. The process went on due to the sufficient supply of dissolved oxygen and AuNPs were rapidly etched. Meanwhile, a visible color change from red to colorless was observed. Subsequent tests confirmed such a non-aggregation-based method as a sensitive (LOD= 5.0 nM or 032 ppb) and selective (at least 100-fold over other metal ions except for Pb2+ and Mn2+) way for the detection of Cu2+ (linear range, 10-80 nM). Moreover, our results show that the color change induced by 40 nM Cu2+ can be easily observed by naked eyes, which is particularly applicable to fast on-site investigations. (C) 2013 Elsevier B.V. All rights reserved

Stabilizing Sharpness-aware Minimization Through A Simple Renormalization Strategy

Recently, sharpness-aware minimization (SAM) has attracted a lot of attention because of its surprising effectiveness in improving generalization performance.However, training neural networks with SAM can be highly unstable since the loss does not decrease along the direction of the exact gradient at the current point, but instead follows the direction of a surrogate gradient evaluated at another point nearby. To address this issue, we propose a simple renormalization strategy, dubbed StableSAM, so that the norm of the surrogate gradient maintains the same as that of the exact gradient. Our strategy is easy to implement and flexible enough to integrate with SAM and its variants, almost at no computational cost. With elementary tools from convex optimization and learning theory, we also conduct a theoretical analysis of sharpness-aware training, revealing that compared to stochastic gradient descent (SGD), the effectiveness of SAM is only assured in a limited regime of learning rate. In contrast, we show how StableSAM extends this regime of learning rate and when it can consistently perform better than SAM with minor modification. Finally, we demonstrate the improved performance of StableSAM on several representative data sets and tasks.Comment: 31 page

Development and validation of a novel nomogram model for identifying risk of prolonged length of stay among patients receiving free vascularized flap reconstruction of head and neck cancer

BackgroundThe aim of the present study was to build and internally validate a nomogram model for predicting prolonged length of stay (PLOS) among patients receiving free vascularized flap reconstruction of head and neck cancer (HNC).MethodsA retrospective clinical study was performed at a single center, examining patients receiving free vascularized flap reconstruction of HNC from January 2011 to January 2019. The variables were obtained from the electronic information system. The primary outcome measure was PLOS. Univariate and multivariate analyses were used to find risk factors for predicting PLOS. A model was then built according to multivariate results. Internal validation was implemented via 1000 bootstrap samples.ResultsThe study included 1047 patients, and the median length of stay (LOS) was 13.00 (11.00, 16.00) days. Multivariate analysis showed that flap types ((radial forearm free flap (odds ratio [OR] = 2.238; 95% CI, 1.403-3.569; P = 0.001), free fibula flap (OR = 3.319; 95% CI, 2.019-4.882; P < 0.001)), duration of surgery (OR = 1.002; 95% CI, 1.001-1.003; P = 0.004), postoperative complications (OR = 0.205; 95% CI, 0.129-0.325; P = P < 0.001) and unplanned reoperation (OR = 0.303; 95% CI, 0.140-0.653; P = 0.002) were associated with PLOS. In addition to these variables, blood transfusion was comprised in the model. The AUC of the model was 0.78 (95% CI, 0.711–0.849) and 0.725 (95% CI, 0.605–0.845) in the primary and internal validation cohorts, respectively. The DCA revealed the clinical utility of the current model when making intervention decisions within the PLOS possibility threshold range of 0.2-0.8.ConclusionsOur study developed a nomogram that exhibits a commendable level of accuracy, thereby aiding clinicians in assessing the risk of PLOS among patients receiving free vascularized flap reconstruction for HNC

Seismic Data Interpolation based on Denoising Diffusion Implicit Models with Resampling

The incompleteness of the seismic data caused by missing traces along the spatial extension is a common issue in seismic acquisition due to the existence of obstacles and economic constraints, which severely impairs the imaging quality of subsurface geological structures. Recently, deep learning-based seismic interpolation methods have attained promising progress, while achieving stable training of generative adversarial networks is not easy, and performance degradation is usually notable if the missing patterns in the testing and training do not match. In this paper, we propose a novel seismic denoising diffusion implicit model with resampling. The model training is established on the denoising diffusion probabilistic model, where U-Net is equipped with the multi-head self-attention to match the noise in each step. The cosine noise schedule, serving as the global noise configuration, promotes the high utilization of known trace information by accelerating the passage of the excessive noise stages. The model inference utilizes the denoising diffusion implicit model, conditioning on the known traces, to enable high-quality interpolation with fewer diffusion steps. To enhance the coherency between the known traces and the missing traces within each reverse step, the inference process integrates a resampling strategy to achieve an information recap on the former interpolated traces. Extensive experiments conducted on synthetic and field seismic data validate the superiority of our model and its robustness on various missing patterns. In addition, uncertainty quantification and ablation studies are also investigated.Comment: 14 pages, 13 figure

Different physiopsychological changes between AMSsusceptible and AMS-resistant pre-selected Antarctic expeditioners in Tibet

Through dynamically monitoring changes of acute mountain sickness (AMS) occurrences, cardiopulmonary function and mood states from Shanghai (4 m) to Lhasa (3650 m) and Yambajan (4300 m), Tibet, we obtained physiopsychological data of the 37th Chinese Antarctic pre-selected expeditioners for Kunlun Station. Through analyzing different physiopsychological changes between AMS-susceptible (AMS-S) and AMS-resistant (AMS-R) expeditioners, we would explore indicators to screen hypoxia-susceptible expeditioners. According to AMS occurrences evaluated by Lake Louise Score (LLS) in Yambajan, we divided the expeditioners (n=24, 31.92±5.76 a) into AMS-S and AMS-R groups. Using a series of medical instruments and questionnaires, we monitored their cardiopulmonary function and mood states, and analyzed the differences of physiopsychological parameters between AMS-S and AMS-R groups. Compared with Shanghai, when expeditioners arrived in Yambajan, in both AMS-S and AMS-R groups, oxygen saturation (SpO2) significantly decreased, and blood pressure significantly increased (P<0.05). As for electrocardiogram (ECG), interval from the beginning to the end of QRS complex wave (QRS), interval from the beginning of QRS complex wave to the end of T wave (QT), interval between 2 adjacent P waves (PP) and interval between 2 adjacent R waves (RR) significantly decreased, heart rate (HR) and HR-corrected QT interval (QTc) significantly increased (P<0.05). Cardiac contractility and pumping function significantly decreased, systemic vascular resistance significantly increased (P<0.05). Pulmonary airway patency significantly increased (P<0.05). Compared with AMS-R group, AMS-S group showed significantly lower SpO2 and higher stroke volume variation (SVV) in Shanghai, however, significantly lower maximal expiratory flow at 75% of forced vital capacity (MEF75), higher levels of anxiety, fatigue and confusion in Yambajan (P<0.05). In conclusion, when expeditioners arrived at 4300 m, their cardiopulmonary function and mood states changed significantly. SpO2, SVV, MEF75, anxiety, fatigue and confusion maybe could be used as clues for screening hypoxia-susceptible individuals

Esophageal stricture complicated with cardia cancer after endoscopic injection sclerotherapy for esophago-gas-tric fundal varices rupture bleeding: a case report

Cardia cancer patients complicated with cirrhosis，hypersplenism，and portal hypertension constantly have contraindications to systemic drugs such as chemotherapy due to poor liver function，and surgery has become the preferred treatment for patients with such cardia tumors. Evaluation of surgical indications，optimization of surgical regimen，and perioperative management strategy are key factors for safe and successful implementation of these surgeries. Here，we reported a 65-year-old male patient undergoing laparoscopic splenectomy plus pericardiac vascularization combined with radical resection of cardiac carcinoma. Satisfactory clinical efficacy was obtained. He could eat semi-liquid diet at 2 weeks after surgery. During over 1-year follow-up，the patient was generally in good condition，could eat normal diet，and the white blood cell，red blood cell and platelet were restored normal. Liver function was normal，and no thrombosis was seen on portal ultrasound. This case prompts that for cardia cancer patients complicated with cirrhosis，hypersplenism，esophago-gas-tric fundal varices，esophageal stricture，this surgical regimen provides novel therapeutic ideas，which can be utilized as a safe and effective treatment option

Recent Advances in Soft Biological Tissue Manipulating Technologies

Biological soft tissues manipulation, including conventional (mechanical) and nonconventional (laser, waterjet and ultrasonic) processes, is critically required in most surgical innervations. However, the soft tissues, with their nature of anisotropic and viscoelastic mechanical properties, and high biological and heat sensitivities, are difficult to manipulated. Moreover, the mechanical and thermal induced damage on the surface and surrounding tissue during the surgery can impair the proliferative phase of healing. Thus, understanding the manipulation mechanism and the resulted surface damage is of importance to the community. In recent years, more and more scholars carried out researches on soft biological tissue cutting in order to improve the cutting performance of surgical instruments and reduce the surgery induced tissue damage. However, there is a lack of compressive review that focused on the recent advances in soft biological tissue manipulating technologies. Hence, this review paper attempts to provide an informative literature survey of the state-of-the-art of soft tissue manipulation processes in surgery. This is achieved by exploring and recollecting the different soft tissue manipulation techniques currently used, including mechanical, laser, waterjet and ultrasonic cutting and advanced anastomosis and reconstruction processes, with highlighting their governing removal mechanisms as well as the surface and subsurface damages

Lithium tantalate electro-optical photonic integrated circuits for high volume manufacturing

Photonic integrated circuits based on Lithium Niobate have demonstrated the vast capabilities afforded by material with a high Pockels coefficient, allowing linear and high-speed modulators operating at CMOS voltage levels for applications ranging from data-center communications and photonic accelerators for AI. However despite major progress, the industrial adoption of this technology is compounded by the high cost per wafer. Here we overcome this challenge and demonstrate a photonic platform that satisfies the dichotomy of allowing scalable manufacturing at low cost, while at the same time exhibiting equal, and superior properties to those of Lithium Niobate. We demonstrate that it is possible to manufacture low loss photonic integrated circuits using Lithium Tantalate, a material that is already commercially adopted for acoustic filters in 5G and 6G. We show that LiTaO3 posses equally attractive optical properties and can be etched with high precision and negligible residues using DUV lithography, diamond like carbon (DLC) as a hard mask and alkaline wet etching. Using this approach we demonstrate microresonators with an intrinsic cavity linewidth of 26.8 MHz, corresponding to a linear loss of 5.6 dB/m and demonstrate a Mach Zehnder modulator with Vpi L = 4.2 V cm half-wave voltage length product. In comparison to Lithium Niobate, the photonic integrated circuits based on LiTaO3 exhibit a much lower birefringence, allowing high-density circuits and broadband operation over all telecommunication bands (O to L band), exhibit higher photorefractive damage threshold, and lower microwave loss tangent. Moreover, we show that the platform supports generation of soliton microcombs in X-Cut LiTaO3 racetrack microresonator with electronically detectable repetition rate, i.e. 30.1 GHz.Comment: 8 pages, 4 figure