99 research outputs found

    Role of Autophagy in Post-Mitotic Midbody Fate and Function: A Dissertation

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    The midbody (MB) is a proteinaceous complex formed between the two daughter cells during cell division and is required for the final cell separation event in late cytokinesis. After cell division, the post-mitotic midbody, or midbody derivative (MBd), can be retained and accumulated in a subpopulation of cancer cells and stem cells, but not in normal diploid differentiated cells. However, the mechanisms by which MBds accumulate and function are unclear. Based on this, I hypothesize that the MBd is degraded by autophagy after cell division in normal diploid differentiated cells, whereas non-differentiated cells have low autophagic activity and would accumulate MBds. Indeed, I found this to be the case. MBd degradation occurred soon after cytokinesis in differentiated cells that possess high autophagic activity. Specifically, I found MBd degradation to be mediated by binding of the autophagy receptor, NBR1, to the MB protein Cep55. Moreover, by performing proteomic analysis of NBR1 interactions I found additional MB-localized proteins that are potential substrates for NBR1. In contrast to differentiated cells, stem and cancer cells have low autophagic activity thus MBds evade autophagosome encapsulation and accumulate. To examine whether MBds can define the differentiation status of a cell, we depleted NBR1 from differentiated fibroblasts causing an increase in MBd number. Strikingly, under these conditions, reprogramming of fibroblasts to pluripotent stem cells is increased. Equally interestingly, cancer cells with increased MBds have increased in vitro tumorigenicity. In conclusion, this study gives an insight into the fates of post-mitotic midbodies and also suggests a non-cytokinetic role of midbodies in enhancing pluripotency in stem cells and cancer stem cells

    Biomarkers in long COVID-19: A systematic review

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    PurposeLong COVID, also known as post-acute sequelae of COVID-19, refers to the constellation of long-term symptoms experienced by people suffering persistent symptoms for one or more months after SARS-CoV-2 infection. Blood biomarkers can be altered in long COVID patients; however, biomarkers associated with long COVID symptoms and their roles in disease progression remain undetermined. This study aims to systematically evaluate blood biomarkers that may act as indicators or therapeutic targets for long COVID.MethodsA systematic literature review in PubMed, Embase, and CINAHL was performed on 18 August 2022. The search keywords long COVID-19 symptoms and biomarkers were used to filter out the eligible studies, which were then carefully evaluated.ResultsIdentified from 28 studies and representing six biological classifications, 113 biomarkers were significantly associated with long COVID: (1) Cytokine/Chemokine (38, 33.6%); (2) Biochemical markers (24, 21.2%); (3) Vascular markers (20, 17.7%); (4) Neurological markers (6, 5.3%); (5) Acute phase protein (5, 4.4%); and (6) Others (20, 17.7%). Compared with healthy control or recovered patients without long COVID symptoms, 79 biomarkers were increased, 29 were decreased, and 5 required further determination in the long COVID patients. Of these, up-regulated Interleukin 6, C-reactive protein, and tumor necrosis factor alpha might serve as the potential diagnostic biomarkers for long COVID. Moreover, long COVID patients with neurological symptoms exhibited higher levels of neurofilament light chain and glial fibrillary acidic protein whereas those with pulmonary symptoms exhibited a higher level of transforming growth factor beta.ConclusionLong COVID patients present elevated inflammatory biomarkers after initial infection. Our study found significant associations between specific biomarkers and long COVID symptoms. Further investigations are warranted to identify a core set of blood biomarkers that can be used to diagnose and manage long COVID patients in clinical practice

    Real-Time Telemetry System for Amperometric and Potentiometric Electrochemical Sensors

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    A real-time telemetry system, which consists of readout circuits, an analog-to-digital converter (ADC), a microcontroller unit (MCU), a graphical user interface (GUI), and a radio frequency (RF) transceiver, is proposed for amperometric and potentiometric electrochemical sensors. By integrating the proposed system with the electrochemical sensors, analyte detection can be conveniently performed. The data is displayed in real-time on a GUI and optionally uploaded to a database via the Internet, allowing it to be accessed remotely. An MCU was implemented using a field programmable gate array (FPGA) to filter noise, transmit data, and provide control over peripheral devices to reduce power consumption, which in sleep mode is 70 mW lower than in operating mode. The readout circuits, which were implemented in the TSMC 0.18-μm CMOS process, include a potentiostat and an instrumentation amplifier (IA). The measurement results show that the proposed potentiostat has a detectable current range of 1 nA to 100 μA, and linearity with an R2 value of 0.99998 in each measured current range. The proposed IA has a common-mode rejection ratio (CMRR) greater than 90 dB. The proposed system was integrated with a potentiometric pH sensor and an amperometric nitrite sensor for in vitro experiments. The proposed system has high linearity (an R2 value greater than 0.99 was obtained in each experiment), a small size of 5.6 cm × 8.7 cm, high portability, and high integration

    Assessment of Renal Function by the Stable Oxygen and Hydrogen Isotopes in Human Blood Plasma

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    Water (H2O) is the most abundant and important molecule of life. Natural water contains small amount of heavy isotopes. Previously, few animal model studies have shown that the isotopic composition of body water could play important roles in physiology and pathophysiology. Here we study the stable isotopic ratios of hydrogen (δ2H) and oxygen (δ18O) in human blood plasma. The stable isotopic ratio is defined and determined by δsample = [(Rsample/RSTD)−1] * 1000, where R is the molar ratio of rare to abundant, for example, 18O/16O. We observe that the δ2H and the δ18O in human blood plasma are associated with the human renal functions. The water isotope ratios of the δ2H and δ18O in human blood plasma of the control subjects are comparable to those of the diabetes subjects (with healthy kidney), but are statistically higher than those of the end stage renal disease subjects (p<0.001 for both ANOVA and Student's t-test). In addition, our data indicate the existence of the biological homeostasis of water isotopes in all subjects, except the end stage renal disease subjects under the haemodialysis treatment. Furthermore, the unexpected water contents (δ2H and δ18O) in blood plasma of body water may shed light on a novel assessment of renal functions

    CD133-positive hepatocellular carcinoma in an area endemic for hepatitis B virus infection

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    <p>Abstract</p> <p>Background</p> <p>CD133 was detected in several types of cancers including hepatocellular carcinoma (HCC), which raised the possibility of stem cell origin in a subset of cancers. However, reappearance of embryonic markers in de-differentiated malignant cells was commonly observed. It remained to be elucidated whether CD133-positive HCCs were indeed of stem cell origin or they were just a group of poorly differentiated cells acquiring an embryonic marker. The aim of this study was to investigate the significance of CD133 expression in HCC in an area endemic for hepatitis B virus (HBV) infection to gain insights on this issue.</p> <p>Methods</p> <p>154 HCC patients receiving total removal of HCCs were included. 104 of them (67.5%) were positive for HBV infection. The cancerous and adjacent non-cancerous liver tissues were subjected for Western blot and immunohistochemistry analysis for CD133 expression. The data were correlated with clinical parameters, patient survivals, and p53 expression.</p> <p>Results</p> <p>Of 154 patients, 24 (15.6%) had CD133 expression in HCC. Univariate and multivariate logistic regression analysis revealed that CD133 expression was negatively correlated with the presence of hepatitis B surface antigen (HBsAg). The unadjusted and adjusted odds ratios were 0.337 (95%CI 0.126 - 0.890) and 0.084 (95%CI 0.010 - 0.707), respectively. On the other hand, p53 expression was positively associated with the presence of HBsAg in univariate analysis. The unadjusted odds ratio was 4.203 (95%CI 1.110 - 18.673). Survival analysis indicated that both CD133 and p53 expression in HCC predicted poor disease-free survival (P = 0.009 and 0.001, respectively), whereas only CD133 expression predicted poor overall survival (P = 0.001). Cox proportional hazard model showed that p53 and CD133 expression were two independent predictors for disease-free survival. The hazard ratios were 1.697 (95% CI 1.318 - 2.185) and 2.559 (95% CI 1.519 - 4.313), respectively (P < 0.001 for both).</p> <p>Conclusion</p> <p>In area where HBV infection accounts for the major attributive risk of HCC, CD133 expression in HCC was negatively associated with the presence of HBsAg, implicating a non-viral origin of CD133-positive HCC. Additionally, CD133 expression predicted poor disease-free survival independently of p53 expression, arguing for two distinguishable hepatocarcinogenesis pathways.</p

    The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

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    Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase&nbsp;1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation&nbsp;disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age&nbsp; 6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score&nbsp; 652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc&nbsp;= 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N&nbsp;= 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in&nbsp;Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in&nbsp;Asia&nbsp;and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701

    Trust of the Crowd and Audit Pricing

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    Effect of Voltage Pulse Width and Synchronized Substrate Bias in High-Power Impulse Magnetron Sputtering of Zirconium Films

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    The Zr film microstructure is highly influenced by the energy of the plasma species during the deposition process. The influences of the discharge pulse width, which is the key factor affecting ionization of sputtered species in the high-power impulse magnetron sputtering (HiPIMS) process, on the obtained microstructure of films is investigated in this research. The films deposited at different argon pressure and substrate biasing are compared. With keeping the same average HiPIMS power and duty cycle, the film growth rate of the Zr film decreases with increasing argon pressure and enhancing substrate biasing. In addition, the film growth rate decreases with the elongating HiPIMS pulse width. For the deposition at 1.2 Pa argon, extending the pulse width not only intensifies the ion flux toward the substrate but also increases the fraction of highly charged ions, which alter the microstructure of films from individual hexagonal prism columns into a tightly connected irregular column. Increasing film density leads to higher hardness. Sufficient synchronized negative substrate biasing and longer pulse width, which supports higher mobility of adatoms, causes the preferred orientation of hexagonal &alpha;-phase Zr films from (0 0 0 2) to (1 0 1&macr; 1). Unlike the deposition at 1.2 Pa, highly charged ions are also found during the short HiPIMS pulse width at 0.8 Pa argon

    Effects of Cathode Voltage Pulse Width in High Power Impulse Magnetron Sputtering on the Deposited Chromium Thin Films

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    Environmentally-safe high-power impulse magnetron sputtering (HiPIMS) technology was utilized to deposit chromium films. This research focused on the influences of the HiPIMS pulse widths on the microstructure of films deposited at different deposition pressures and substrate bias voltages. Under the conditions of the same average HiPIMS power and duty cycle, the deposition rate of the Cr thin film at working pressure 0.8 Pa is slightly higher than at 1.2 Pa. Also, the difference between deposition rates under two pressures decreases with the discharge pulse width. The deposition rate of the short pulse width 60 &mu;s is lowest, but those of 200 and 360 &mu;s are approximately the same. With no or small direct current substrate biasing, the microstructure of films coated at short pulse width is similar to the typical magnetron sputtering deposited films. Elongating the pulse width enhances the ion flux toward the substrate and changes the film structure from individual prism-like columns into tangled 3-point/4-point star columns. Substantial synchronized substrate biasing and longer pulse width changes the preferred orientation of Cr films from Cr (110) to Cr (200) and Cr (211). The films deposited at longer pulse width exhibit a higher hardness due to the reducing of intercolumn voids

    KubAnomaly: Anomaly detection for the Docker orchestration platform with neural network approaches

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    Kubernetes, which is the most popular orchestration platform for Docker containers, is used widely for developing microservices and automating Docker instance life cycle administration. Because of advancements in containerization technology, a single server can run multiple services and use hardware resources more efficiently. However, containerized environments also bring new challenges in terms of complete monitoring and security provision. Thus, hackers can exploit the security vulnerabilities of containers to gain remote control permissions and cause extensive damage to company assets. Therefore, in this study, we propose KubAnomaly, a system that provides security monitoring capabilities for anomaly detection on the Kubernetes orchestration platform. We develop a container monitoring module for Kubernetes and implement neural network approaches to create classification models that strengthen its ability to find abnormal behaviors such as web service attacks and common vulnerabilities and exposures attacks. We use three types of datasets to evaluate our system, including privately collected and publicly available datasets as well as real‐world experiment data. Furthermore, we demonstrate the effectiveness of KubAnomaly by comparing its accuracy with that of other machine learning algorithms. KubAnomaly is shown to achieve an overall accuracy of up to 96% for anomaly detection. It successfully identifies four real attacks carried out by hackers in September 2018. Moreover, its performance overhead is only 5% greater than that of current methods. In summary, KubAnomaly significantly improves container security by avoiding anomaly attacks
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