Enhancing Tsunami Warning Using P Wave Coda

Most large tsunamis are generated by earthquakes on offshore plate boundary megathrusts. The primary factors influencing tsunami excitation are the seismic moment, faulting geometry, and depth of the faulting. Efforts to provide rapid tsunami warning have emphasized seismic and geodetic methods for quickly determining the event size and faulting geometry. It remains difficult to evaluate the updip extent of rupture, which has significant impact on tsunami excitation. Teleseismic P waves can constrain this issue; slip under deep water generates strong pwP water reverberations that persist as ringing P_(coda) after the direct P phases from the faulting have arrived. Event‐averaged P_(coda)/P amplitude measures at large epicentral distances (>80°), tuned to the dominant periods of deep water pwP (~12–15 s), correlate well with independent models of whether slip extends to near the trench or not. Data at closer ranges (30° to 80°) reduce the time lag needed for inferring the updip extent of rupture to <15 min. Arrival of PP and PPP phases contaminates closer distance P_(coda) measures, but this can be suppressed by azimuthal or distance binning of the measures. Narrowband spectral ratio measures and differential magnitude measures of P_(coda) and direct P (m_B) perform comparably to broader band root‐mean‐square (RMS) measures. P_(coda)/P levels for large nonmegathrust events are also documented. Rapid measurement of P_(coda)/P metrics after a large earthquake can supplement quick moment tensor determinations to enhance tsunami warnings; observation of large P_(coda) levels indicates that shallow submarine rupture occurred and larger than typical tsunami (for given M_W) can be expected

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

Sleep architecture, periodic breathing and mood disturbance of expeditioners at Kunlun Station (4087 m) in Antarctica

Several studies have reported the detrimental impacts of hypoxia exposure on sleep. Chinese Kunlun Station (altitude 4087 m) is located at Dome A, the highest point on the Antarctic ice sheet and one of the most extreme environments on Earth. This study investigated alteration of sleep, breathing and mood status in healthy expeditioners at Kunlun Station at Dome A. The study examined 10 male volunteers of the inland transverse party to Kunlun Station during the 31st Chinese National Antarctic Research Expedition, and valid data from eight volunteers were analyzed. Sleep structure, breathing pattern and mood were monitored using portable polysomnography (PSG) and profile of mood state (POMS) at two time points: (1) at Zhongshan Station (10 m) before departure to Kunlun Station; (2) on nights 12 –13 of residence at Kunlun Station. Slow-wave sleep (Stage 3 non-rapid eye movement) was markedly reduced at Kunlun Station (P < 0.01). Total sleep time, sleep efficiency and sleep latency showed no significant changes. Total respiratory events (P < 0.05), apnea/hypopnea index (AHI) (P < 0.05) and hypopnea index (P < 0.01) substantially increased at Kunlun Station. The most common respiratory disorder was periodic breathing, occurring almost exclusively during non-rapid eye movement sleep. The oxygen desaturation index increased markedly (P < 0.05), while nocturnal oxygen saturation dramatically fell at Kunlun Station (P < 0.05). Vigor scores decreased at Kunlun Station (P < 0.05). Expeditioners exhibited reduced slow wave sleep, induced periodic breathing, decreased oxygen saturation and decreased vigor at Kunlun Station

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

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