97 research outputs found
Coherent terahertz radiation with 2.8-octave tunability through chip-scale photomixed microresonator optical parametric oscillation
High spectral purity frequency agile room temperature sources in the
terahertz spectrum are foundational elements for imaging, sensing, metrology,
and communications. Here we present a chip scale optical parametric oscillator
based on an integrated nonlinear microresonator that provides broadly tunable
single frequency and multi frequency oscillators in the terahertz regime.
Through optical to terahertz down conversion using a plasmonic nanoantenna
array, coherent terahertz radiation spanning 2.8 octaves is achieved from 330
GHz to 2.3 THz, with 20 GHz cavity mode limited frequency tuning step and 10
MHz intracavity mode continuous frequency tuning range at each step. By
controlling the microresonator intracavity power and pump resonance detuning,
tunable multi frequency terahertz oscillators are also realized. Furthermore,
by stabilizing the microresonator pump power and wavelength, sub 100 Hz
linewidth of the terahertz radiation with 10-15 residual frequency instability
is demonstrated. The room temperature generation of both single frequency,
frequency agile terahertz radiation and multi frequency terahertz oscillators
in the chip scale platform offers unique capabilities in metrology, sensing,
imaging and communications
Endoluminal surgical triangulation: overcoming challenges of colonic endoscopic submucosal dissections using a novel flexible endoscopic surgical platform: feasibility study in a porcine model
Background: Colonic endoscopic submucosal dissection (ESD) is challenging as a result of the limited ability of conventional endoscopic instruments to achieve traction and exposure. The aim of this study was to evaluate the feasibility of colonic ESD in a porcine model using a novel endoscopic surgical platform, the Anubiscope (Karl Storz, Tüttlingen, Germany), equipped with two working channels for surgical instruments with four degrees of freedom offering surgical triangulation. Methods: Nine ESDs were performed by a surgeon without any ESD experience in three swine, at 25, 15, and 10cm above the anal verge with the Anubiscope. Sixteen ESDs were performed by an experienced endoscopist in five swine using conventional endoscopic instruments. Major ESD steps included the following for both groups: scoring the area, submucosal injection of glycerol, precut, and submucosal dissection. Outcomes measured were as follows: dissection time and speed, specimen size, en bloc dissection, and complications. Results: No perforations occurred in the Anubis group, while there were eight perforations (50%) in the conventional group (p=0.02). Complete and en bloc dissections were achieved in all cases in the Anubis group. Mean dissection time for completed cases was statistically significantly shorter in the Anubis group (32.3±16.1 vs. 55.87±7.66min; p=0.0019). Mean specimen size was higher in the conventional group (1321±230 vs. 927.77±229.96mm2; p=0.003), but mean dissection speed was similar (35.95±18.93 vs. 23.98±5.02mm2/min in the Anubis and conventional groups, respectively; p=0.1). Conclusions: Colonic ESDs were feasible in pig models with the Anubiscope. This surgical endoscopic platform is promising for endoluminal surgical procedures such as ESD, as it is user-friendly, effective, and saf
Expert consensus on spontaneous ventilation video-assisted thoracoscopic surgery in primary spontaneous pneumothorax (Guangzhou)
Look, the World is Watching How We Treat Migrants! The Making of the Anti-Trafficking Legislation during the Ma Administration
Employing the spiral model, this research analyses how anti-human trafficking legislation was promulgated during the Ma Ying-jeou (Ma Yingjiu) presidency. This research found that the gov- ernment of Taiwan was just as accountable for the violation of mi- grants’ human rights as the exploitive placement agencies and abusive employers. This research argues that, given its reliance on the United States for political and security support, Taiwan has made great ef- forts to improve its human rights records and meet US standards for protecting human rights. The reform was a result of multilevel inputs, including US pressure and collaboration between transnational and domestic advocacy groups. A major contribution of this research is to challenge the belief that human rights protection is intrinsic to dem- ocracy. In the same light, this research also cautions against Taiwan’s subscription to US norms since the reform was achieved at the cost of stereotyping trafficking victimhood, legitimising state surveillance, and further marginalising sex workers
Tubeless video-assisted thoracic surgery for pulmonary ground-glass nodules: expert consensus and protocol (Guangzhou)
Association analyses of East Asian individuals and trans-ancestry analyses with European individuals reveal new loci associated with cholesterol and triglyceride levels
Large-scale meta-analyses of genome-wide association studies (GWAS) have identified >175 loci associated with fasting cholesterol levels, including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG). With differences in linkage disequilibrium (LD) structure and allele frequencies between ancestry groups, studies in additional large samples may detect new associations. We conducted staged GWAS meta-analyses in up to 69,414 East Asian individuals from 24 studies with participants from Japan, the Philippines, Korea, China, Singapore, and Taiwan. These meta-analyses identified (P < 5 × 10-8) three novel loci associated with HDL-C near CD163-APOBEC1 (P = 7.4 × 10-9), NCOA2 (P = 1.6 × 10-8), and NID2-PTGDR (P = 4.2 × 10-8), and one novel locus associated with TG near WDR11-FGFR2 (P = 2.7 × 10-10). Conditional analyses identified a second signal near CD163-APOBEC1. We then combined results from the East Asian meta-analysis with association results from up to 187,365 European individuals from the Global Lipids Genetics Consortium in a trans-ancestry meta-analysis. This analysis identified (log10Bayes Factor ≥6.1) eight additional novel lipid loci. Among the twelve total loci identified, the index variants at eight loci have demonstrated at least nominal significance with other metabolic traits in prior studies, and two loci exhibited coincident eQTLs (P < 1 × 10-5) in subcutaneous adipose tissue for BPTF and PDGFC. Taken together, these analyses identified multiple novel lipid loci, providing new potential therapeutic targets
Tokyo Guidelines 2018: initial management of acute biliary infection and flowchart for acute cholangitis
The initial management of patients with suspected acute biliary infection starts with the measurement of vital signs to assess whether or not the situation is urgent. If the case is judged to be urgent, initial medical treatment should be started immediately including respiratory/circulatory management if required, without waiting for a definitive diagnosis. The patient's medical history is then taken; an abdominal examination is performed; blood tests, urinalysis, and diagnostic imaging are carried out; and a diagnosis is made using the diagnostic criteria for cholangitis/cholecystitis. Once the diagnosis has been confirmed, initial medical treatment should be started immediately, severity should be assessed according to the severity grading criteria for acute cholangitis/cholecystitis, and the patient's general status should be evaluated. For mild acute cholangitis, in most cases initial treatment including antibiotics is sufficient, and most patients do not require biliary drainage. However, biliary drainage should be considered if a patient does not respond to initial treatment. For moderate acute cholangitis, early endoscopic or percutaneous transhepatic biliary drainage is indicated. If the underlying etiology requires treatment, this should be provided after the patient's general condition has improved; endoscopic sphincterotomy and subsequent choledocholithotomy may be performed together with biliary drainage. For severe acute cholangitis, appropriate respiratory/circulatory management is required. Biliary drainage should be performed as soon as possible after the patient's general condition has been improved by initial treatment and respiratory/circulatory management. Free full articles and mobile app of TG18 are available at: http://www.jshbps.jp/modules/en/index.php?content_id=47 . Related clinical questions and references are also include
Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world
Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic.
Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality.
Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States.
Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis.
Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection
TG18 management strategies for gallbladder drainage in patients with acute cholecystitis: Updated Tokyo Guidelines 2018 (with videos)
Since the publication of the Tokyo Guidelines in 2007 and their revision in 2013, appropriate management for acute cholecystitis has been more clearly established. Since the last revision, several manuscripts, especially for alternative endoscopic techniques, have been reported; therefore, additional evaluation and refinement of the 2013 Guidelines is required. We describe a standard drainage method for surgically high-risk patients with acute cholecystitis and the latest developed endoscopic gallbladder drainage techniques described in the updated Tokyo Guidelines 2018 (TG18). Our study confirmed that percutaneous transhepatic gallbladder drainage should be considered the first alternative to surgical intervention in surgically high-risk patients with acute cholecystitis. Also, endoscopic transpapillary gallbladder drainage or endoscopic ultrasound-guided gallbladder drainage can be considered in high-volume institutes by skilled endoscopists. In the endoscopic transpapillary approach, either endoscopic naso-gallbladder drainage or gallbladder stenting can be considered for gallbladder drainage. We also introduce special techniques and the latest outcomes of endoscopic ultrasound-guided gallbladder drainage studies. Free full articles and mobile app of TG18 are available at: . Related clinical questions and references are also include
Progressive Band Prioritization and Selection for Linear Spectral Mixture Analysis
Linear Spectral Mixture Analysis (LSMA) has been widely used in the remote sensing community. It assumes that a data sample vector is linearly mixed by a set of distinct signatures as a linear mixture from which it can be further unmixed as abundance fractions in terms of these signatures. While LSMA has shown to be a promising spectral unmixing technique in remote sensing image analysis, it also suffers from an issue of nonlinear separability encountered in both multispectral and hyperspectral image processing. To resolve this dilemma, a kernel-based LSMA (KLSMA) is proposed in this dissertation, which projects data samples into a high dimensional feature space to solve linearly non-separable problems. Similar techniques are further used to extend Fisher's LSMA (KFLSMA), Weighted Abundance Constrained LSMA (KWAC-LSMA) to their kernel-based versions, referred to as kernel-based FLSMA (KFLSMA), and kernel-based WAC-LSMA (KWAC-LSMA). Since hyperspectral imagery is generally acquired in hundreds of contiguous spectral channels with very high spectral resolution such high inter-band correlation provides high redundant information and can be removed with no significant loss of information. So, it has been a great interest in hyperspectral image analysis to seek a means of how to effectively reduce dimensionality without significantly compromising performance. Band Selection (BS) is one of commonly used approaches for this purpose. However, there are several crucial issues arising in BS which must be addressed, such as the number of bands required for BS to select, p, and what criterion needed to be used to select bands. In order to solve these issues, Band Prioritization (BP) is introduced in this dissertation from which Progressive Band Dimensionality Process (PBDP) is derived to rank bands according to BP which paves the way for a subsequently developed Progressive Band Selection (PBS). Due to practical issues the number of bands to be selected must adapt to various applications instead of being fixed at a constant as BS does. To further mitigate this problem, a new concept of Band Dimensionality Allocation (BDA) is introduced, which allows users to determine band dimensionality dynamically according to specific applications. When PBDP is implemented, one issue may arise in the fact that two highly prioritized bands may also share significant information in common. As a result, if one band is selected, the other band should be considered as a redundant band and must be removed by BS. To address this issue, the Band De-correlation (BD) is further proposed for this purpose. Finally, by implementing the PBDP in conjunction with the BDA and the BD a Progressive Band Selection (PBS) can be derived as an alternative to the traditional BS. The experiments conducted in this dissertation show that the PBS provides significant performance and advantages which could not be achieved by traditional BS
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