505 research outputs found
Mechanistic understanding of innate and adaptive immune responses in SARS-CoV-2 infection
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections have triggered global pandemic that continue to impact adversely human health. New understanding has emerged about the innate and adaptive immune responses elicited in SARS-CoV-2 infection. The understanding of innate immune responses generated in hosts early in SARS-CoV-2 infection is vital for treatment efforts. Antiviral cytokines are released by innate immune cells in response to viral infections that play a pivotal role in limiting viral replication, pathology and generating optimal adaptive immune responses alongside the long-term memory responses against reinfections. One aspect of innate immune response generated against SARS-CoV-2 in vivo and which has received much attention has been high proinflammatory cytokine release in COVID-19 patients. Another vital discovery has been that the antiviral cytokine type I Interferon (IFN) family IFN-Îą mediates upregulation of angiotensin converting enzyme 2 (ACE2) membrane protein in airway epithelial cells. ACE2 is a receptor that SARS-CoV-2 binds to infect host cells. New understanding has emerged about the mechanism of SARS-CoV-2 induced exaggerated proinflammatory cytokine release as well as transcriptional regulation of ACE2. This review discusses various mechanisms underlying SARS-CoV-2 induced exaggerated proinflammatory cytokine response as well as transcriptional regulation of ACE2 receptor. We further elaborate on adaptive and memory responses generated against SARS-CoV-2
Task bundling in workerâcentric mobile crowdsensing
Most existing research about task allocation in mobile crowdsensing mainly focus on requester-centric mobile crowdsensing (RCMCS), where the requester assigns tasks to workers to maximize his/her benefits. A worker in RCMCS might suffer benefit damage because the tasks assigned to him/her may not maximize his/her benefit. Contrarily, worker-centric mobile crowdsensing (WCMCS), where workers autonomously select tasks to accomplish to maximize their benefits, does not receive enough attention. The workers in WCMCS can maximize their benefits, but the requester in WCMCS will suffer benefit damage (cannot maximize the number of expected completed tasks). It is hard to maximize the number of expected completed tasks in WCMCS, because some tasks may be selected by no workers, while others may be selected by many workers. In this paper, we apply task bundling to address this issue, and we formulate a novel task bundling problem in WCMCS with the objective of maximizing the number of expected completed tasks. To solve this problem, we design an algorithm named LocTrajBundling which bundles tasks based on the location of tasks and the trajectories of workers. Experimental results show that, compared with other algorithms, our algorithm can achieve a better performance in maximizing the number of expected completed tasks
Persistent Heart Failure Despite Medical Therapy Leading to a Diagnosis of Cardiac Amyloidosis
Cardiac amyloidosis is restrictive cardiomyopathy, commonly classified as either light-chain amyloidosis (AL) or transthyretin amyloidosis (ATTR), which can be further subdivided into wild-type (systemic senile amyloidosis) and hereditary ATTR amyloidosis. Advanced-stage, silent, and clinically undiagnosed amyloidosis has a poor prognosis, with a survival rate of six months and up to five years. We present a 72-year-old female with a past medical history of heart failure, with preserved ejection fraction, atrial fibrillation, systemic lupus erythematosus (SLE), and stage 3b chronic kidney disease, who presented with persistent shortness of breath, lower extremity pitting edema, jugular venous distension, and dyspnea despite optimal medical therapy. The patient was diagnosed with preserved heart failure in the past and was on guideline-directed medical therapy for over five years with no history of cardiac disease in the family. The patient\u27s previous echocardiogram revealed an ejection fraction of 65%. In order to determine the etiology of the patient\u27s cardiomyopathy, she underwent cardiac magnetic resonance imaging (CMR), monoclonal gammopathy testing, and a Technetium pyrophosphate (99mTc-PYP) scintigraphy, of which the latter two were unrevealing. The CMR revealed increased wall thickness and multiple segments of midmyocardial to subendocardial late gadolinium enhancement, suggestive of infiltrative disease. Due to inconclusive testing, the patient underwent an endomyocardial biopsy and was determined to have wild-type, systemic senile amyloidosis, which held a poor prognosis. The patient was started on tafamidis, a new Food and Drug Administration (FDA)-approved therapy for systemic senile amyloidosis, and was discharged on the new medication, with frequent follow-up visits scheduled. Current treatment guidelines for cardiac amyloidosis include loop diuretics and spironolactone. Medications such as beta-blockers, angiotensin-converting enzyme inhibitors, and calcium channel blockers are not clinically effective. There are currently new medications on the horizon, such as tafamidis, which stabilizes the transthyretin tetramer and reduces the formation of amyloid. This case highlighted that patients who have persistent symptoms of heart failure, despite guideline-directed medical therapy, and without a history of genetic cardiac conditions, may also have a diagnosis of cardiac amyloidosis. Cardiac amyloidosis is often misdiagnosed or diagnosed late in the disease course; therefore, there is a need for increasing awareness of early diagnosis and treatment, including new FDA-approved medications for a better chance of survival
Local experts finding using user comments in location-based social networks
The opinions of local experts in the location-based social network are of great significance to the collection and dissemination of local information. In this paper, we investigated in-depth how the user comments can be used to identify the local expert over social networks. We first illustrate the existences of potential local experts in a social network using a scored model by considering the personal profiles, comments, friend relationship, and location preferences. Then, a multi-dimensional model is proposed to evaluate the local expert candidates and a local expert discovery algorithm is proposed to identify local experts. Meanwhile, a scoring algorithm is proposed to train the weights in the model. Finally, an expert recommendation list can be given based on the score ranks of the candidates. Experimental results demonstrate that effectiveness of proposed model and algorithm
Pilot-scale recovery of low molecular weight organic acids from anaerobically treated palm oil mill effluent (POME) with energy integrated system
Low molecular weight organic acids such as acetic acid, propionic acid and butyric acids generated from partial anaerobic treatment of palm oil mill effluent (POME) were recovered using pilot scale filtration and evaporation system. Mechanical filter press (14 L) was used for removing solid fractions and fraction distillation unit (40 L) for evaporation and clarification of concentrated acid from POME. Clarification using rotary evaporator was found to be more suitable than distillation column. Due to the presence of more than 90% of water in POME, the final clarified product comprises only 7% of the total volume. The material balance for the overall process was estimated and integrated system for the bioconversion of organic acids into polyhydroxyalkanoates (PHA) was proposed. The recovery of organic acids has a significant and economical impact, since around 50% cost of PHA production is believed to be associated with the substrate itself
Maternal deaths in Pakistan : intersection of gender, class and social exclusion.
Background: A key aim of countries with high maternal mortality rates is to increase availability of competent
maternal health care during pregnancy and childbirth. Yet, despite significant investment, countries with the
highest burdens have not reduced their rates to the expected levels. We argue, taking Pakistan as a case study,
that improving physical availability of services is necessary but not sufficient for reducing maternal mortality
because gender inequities interact with caste and poverty to socially exclude certain groups of women from
health services that are otherwise physically available.
Methods: Using a critical ethnographic approach, two case studies of women who died during childbirth were
pieced together from information gathered during the first six months of fieldwork in a village in Northern Punjab,
Pakistan.
Findings: Shida did not receive the necessary medical care because her heavily indebted family could not afford it.
Zainab, a victim of domestic violence, did not receive any medical care because her martial family could not afford
it, nor did they think she deserved it. Both women belonged to lower caste households, which are materially poor
households and socially constructed as inferior.
Conclusions: The stories of Shida and Zainab illustrate how a rigidly structured caste hierarchy, the gendered
devaluing of females, and the reinforced lack of control that many impoverished women experience conspire to
keep women from lifesaving health services that are physically available and should be at their disposal
Irreversible magnetization in thin YBCO films rotated in external magnetic field
The magnetization M of a thin YBaCuO film is measured as a function of the
angle between the applied field H and the c-axis. For fields above
the first critical field, but below the Bean's field for first penetration H*,
M is symmetric with respect to and the magnetization curves for
forward and backward rotation coincide. For H>H* the curves are asymmetric and
they do not coincide. These phenomena have a simple explanation in the
framework of the Bean critical state model.Comment: 14 pages, 7 PostScript figure
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Design and analysis of a new index-modulation-aided DCSK system with frequency-and-time resources
We propose a new index-modulation-aided differential chaos shift keying (DCSK) system using frequency-and-time resources, referred to as CTIM-DCSK system, to achieve high-data-rate transmissions. In the proposed system, the orthogonal sinusoidal carriers are used to transmit both the reference-chaotic and the information-bearing signals. Moreover, the frequency-and-time resources are considered as indices to carry additional information bits. To simultaneously boost the bit error rate (BER) performance and reduce the system complexity, this paper proposes a new CTIM-DCSK signal based on the frequency-and-time resources, in which the time slots used by the selected subcarriers convey the same index bits. We employ a noise-reduction method at the receiver to further improve the BER performance of the proposed CTIM-DCSK system. We also derive the theoretical BER expressions of the CTIM-DCSK system over two different channels, i.e., additive white Gaussian noise (AWGN) channel and multipath Rayleigh fading channel. We analyze the data rate, complexity and spectral efficiency of the CTIM-DCSK system in comparison with the state-of-the-art counterparts. Analytical and simulation results verify the accuracy of the theoretical analysis and the advantage of the proposed CTIM-DCSK system. Consequently, the proposed CTIM-DCSK system appears to be a competitive candidate for low-complexity Internet-of-Things applications
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Low-complexity detectors for space-time block coded differential spatial modulation
Space-time block coded differential spatial modulation (STBC-DSM) is a recently proposed DSM-based multiple-input-multiple-output (MIMO) transmission technique with high diversity gain. The existing low-complexity detectors for STBC-DSM can be further designed to reduce complexity. In this paper, we propose an ordered antenna index vector detector (OVD) for STBC-DSM, and an OV-low repetition detector (OV-LRD) for further simplification. The OVD detects the symbols in a designed order, and the OV-LRD fully uses the STBC structure to simplify the OVD. Simulation results show that the OVD achieves near-optimal performance, and the OV-LRD significantly reduces complexity with negligible performance loss
Robot-assisted surgery in horseshoe kidneys: A safety and feasibility multi-centre case series
OBJECTIVE: We assessed the safety and feasibility of minimally invasive robot-assisted surgery for horseshoe kidney (HSK). METHOD: A prospectively maintained data set for consecutive patients undergoing robotic kidney surgery was reviewed for patients with HSK. Cases were performed by experienced robotic surgeons, across two high-volume centres between 2016 and 2020. RESULTS: A prospectively maintained data set for consecutive patients undergoing robotic kidney surgery was reviewed for patients with HSK. Cases were performed by experienced robotic surgeons, across two high-volume centres between 2016 and 2020. CONCLUSION: We report one the largest series of robot-assisted surgery on HSK. Robotic surgery is safe and feasible for HSK in centralised high-volume centres with acceptable perioperative outcomes. Established benefits of minimally invasive surgery, such as reduced LOS and low complication rates, were demonstrated. LEVEL OF EVIDENCE: 4
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