Summary Background Since December, 2019, Wuhan, China, has experienced an outbreak of coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Epidemiological and clinical characteristics of patients with COVID-19 have been reported but risk factors for mortality and a detailed clinical course of illness, including viral shedding, have not been well described. Methods In this retrospective, multicentre cohort study, we included all adult inpatients (≥18 years old) with laboratory-confirmed COVID-19 from Jinyintan Hospital and Wuhan Pulmonary Hospital (Wuhan, China) who had been discharged or had died by Jan 31, 2020. Demographic, clinical, treatment, and laboratory data, including serial samples for viral RNA detection, were extracted from electronic medical records and compared between survivors and non-survivors. We used univariable and multivariable logistic regression methods to explore the risk factors associated with in-hospital death. Findings 191 patients (135 from Jinyintan Hospital and 56 from Wuhan Pulmonary Hospital) were included in this study, of whom 137 were discharged and 54 died in hospital. 91 (48%) patients had a comorbidity, with hypertension being the most common (58 [30%] patients), followed by diabetes (36 [19%] patients) and coronary heart disease (15 [8%] patients). Multivariable regression showed increasing odds of in-hospital death associated with older age (odds ratio 1·10, 95% CI 1·03–1·17, per year increase; p=0·0043), higher Sequential Organ Failure Assessment (SOFA) score (5·65, 2·61–12·23; p Interpretation The potential risk factors of older age, high SOFA score, and d-dimer greater than 1 μg/mL could help clinicians to identify patients with poor prognosis at an early stage. Prolonged viral shedding provides the rationale for a strategy of isolation of infected patients and optimal antiviral interventions in the future. Funding Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences; National Science Grant for Distinguished Young Scholars; National Key Research and Development Program of China; The Beijing Science and Technology Project; and Major Projects of National Science and Technology on New Drug Creation and Development.

Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study

Hydroxychloroquine and azithromycin as a treatment of COVID-19: results of an open-label non-randomized clinical trial.

In a series of 51 patients with chest CT and real-time polymerase chain reaction assay (RT-PCR) performed within 3 days, the sensitivity of CT for 2019 novel coronavirus infection was 98% and that ...

Sensitivity of Chest CT for COVID-19: Comparison to RT-PCR

We extensively compare, qualitatively and quantitatively, 41 state-of-the-art models (29 salient object detection, 10 fixation prediction, 1 objectness, and 1 baseline) over seven challenging data sets for the purpose of benchmarking salient object detection and segmentation methods. From the results obtained so far, our evaluation shows a consistent rapid progress over the last few years in terms of both accuracy and running time. The top contenders in this benchmark significantly outperform the models identified as the best in the previous benchmark conducted three years ago. We find that the models designed specifically for salient object detection generally work better than models in closely related areas, which in turn provides a precise definition and suggests an appropriate treatment of this problem that distinguishes it from other problems. In particular, we analyze the influences of center bias and scene complexity in model performance, which, along with the hard cases for the state-of-the-art models, provide useful hints toward constructing more challenging large-scale data sets and better saliency models. Finally, we propose probable solutions for tackling several open problems, such as evaluation scores and data set bias, which also suggest future research directions in the rapidly growing field of salient object detection.

/pdf/salient-object-detection-a-benchmark-3cltvczcnw.pdf

Salient Object Detection: A Benchmark

https://www.ahajournals.org/doi/pdf/10.1161/STR.0000000000000375

2021 Guideline for the Prevention of Stroke in Patients With Stroke and Transient Ischemic Attack: A Guideline From the American Heart Association/American Stroke Association

The human visual system observes and understands a scene/image by making a series of fixations. Every “fixation point” lies inside a particular region of arbitrary shape and size in the scene which can either be an object or just a part of it. We define as a basic segmentation problem the task of segmenting that region containing the “fixation point”. Segmenting this region is equivalent to finding the enclosing contour - a connected set of boundary edge fragments in the edge map of the scene - around the fixation. We present here a novel algorithm that finds this bounding contour and achieves the segmentation of one object, given the fixation. The proposed segmentation framework combines monocular cues (color/intensity/texture) with stereo and/or motion, in a cue independent manner. We evaluate the performance of the proposed algorithm on challenging videos and stereo pairs. Although the proposed algorithm is more suitable for an active observer capable of fixating at different locations in the scene, it applies to a single image as well. In fact, we show that even with monocular cues alone, the introduced algorithm performs as well or better than a number of image segmentation algorithms, when applied to challenging inputs.

Active segmentation with fixation

Attention is an integral part of the human visual system and has been widely studied in the visual attention literature. The human eyes fixate at important locations in the scene, and every fixation point lies inside a particular region of arbitrary shape and size, which can either be an entire object or a part of it. Using that fixation point as an identification marker on the object, we propose a method to segment the object of interest by finding the “optimal” closed contour around the fixation point in the polar space, avoiding the perennial problem of scale in the Cartesian space. The proposed segmentation process is carried out in two separate steps: First, all visual cues are combined to generate the probabilistic boundary edge map of the scene; second, in this edge map, the “optimal” closed contour around a given fixation point is found. Having two separate steps also makes it possible to establish a simple feedback between the mid-level cue (regions) and the low-level visual cues (edges). In fact, we propose a segmentation refinement process based on such a feedback process. Finally, our experiments show the promise of the proposed method as an automatic segmentation framework for a general purpose visual system.

Active Visual Segmentation

Recently, a new coronavirus disease (COVID-19) has emerged as a respiratory infection with significant concern for global public health hazards. With an initial suspicion of the animal to the human transmission for earlier cases, now the paradigm has shifted towards human to human transmission via droplets, contacts and/or through fomites. with each passing day, more and more confirmed cases are being reported worldwide which has alarmed the global authorities including World Health Organization (WHO), Centers for Disease Control and Prevention (CDC) and the National Health Commission of the People’s Republic of China to take immediate action in order to reduce the transmission and subsequent mortalities associated with COVID-19 to as minimum as possible. Unfortunately, like the previous Coronavirus outbreaks, there is no definite antiviral therapy for the treatment of confirmed cases and hence preventing ourselves from contracting 2019-nCoV is the best way to prevent it from becoming pandemic. Herein, we aim to discuss the latest updates on the origin, genomic characteristics, diagnosis, treatment options and current efforts being made by international health organizations with regards to the 2019-nCoV outbreak.

/pdf/comprehensive-update-on-current-outbreak-of-novel-42d2nve05b.pdf

Comprehensive update on current outbreak of novel coronavirus infection (2019-nCoV)

With each passing day, more cases of Coronavirus disease (COVID-2019) are being detected and unfortunately the fear of novel corona virus 2019 (2019-nCoV) becoming a pandemic disease has come true. Constant efforts at individual, national, and international level are being made in order to understand the genomics, hosts, modes of transmission and epidemiological link of nCoV-2019. As of now, whole genome sequence of the newly discovered coronavirus has already been decoded. Genomic characterization nCoV-2019 have shown close homology with bat-derived severe acute respiratory syndrome (SARS)-like coronaviruses, bat-SL-CoVZC45 and bat-SL-CoVZXC21. Structural analysis of the receptor binding site has confirmed that 2019-nCoV binds with the same ACE 2 receptor protein as human SARS virus. Compared to the previous coronavirus outbreaks, the overall mortality rate is relatively low for COVID-2019 (2-3%). Suspected cases must be quarantined till their test comes positive or they clear infection. At present, treatment of COVID-2019 is mostly based on the knowledge gained from the SARS and MERS outbreaks. Remdesivir, originally develop as a treatment for Ebola virus disease and Marburg virus infections, is being studied for it effectiveness against 2019-nCoV infection. Many other antiviral agents and vaccines are being tested but most of them are in phase I or II and hence unlikely to be of any benefit immediately with regards to current outbreak. Hence, the standard infection control techniques and preventive steps for healthy individuals and supportive care for the confirmed cases is the best available strategy to deal with current viral outbreak. .

/pdf/covid-2019-update-on-epidemiology-disease-spread-and-3et9ud0xn8.pdf

COVID-2019: update on epidemiology, disease spread and management.

Background Cryptococcal meningitis continues to be one of the common causes of chronic central nervous system infection worldwide. Individuals with cryptococcal meningitis can occasionally present with small vessel vasculitis causing infarcts primarily in the basal ganglia, internal capsule, and thalamus. Literature regarding patterns of cerebrovascular injury among patients with cryptococcal meningitis is scanty, and outcome following these vascular involvements is unknown. Aim To study the clinical profile, imaging findings, and details of vascular territory involved among patients admitted with cryptococcal meningitis and central nervous system infarct in a tertiary care center from India. And to compare the outcomes of patients of cryptococcal meningitis with or without central nervous system infarcts in terms of mortality and morbidity, Methodology A total of 151 patients with microbiologically proven cryptococcal meningitis over a time span of 11 years were retrospectively enrolled into the study. Of these, 66 patients met the inclusion criteria of having appropriate imaging of the brain. The presence of infarct in the imaging was analyzed by two independent radiologists. Patterns of central nervous system involvement and types of vascular injury were ascertained based on radiological parameters. Clinical parameters and outcomes of patients with and without infarcts were compared. Results Twenty (13%) of these patients had evidence of central nervous system infarcts on imaging. The mean age of patients with and without infarcts was 41 years and 38 years, respectively. Male predominance was present among both the groups. The presence of fever, neck stiffness, positive blood culture, and hydrocephalus in central nervous system imaging was similar among patients with or without infarct. Longer duration of illness, low sensorium at the time of presentation, low Glasgow Coma Scale score, presence of meningeal inflammation, cryptococcomas, and basal exudates in imaging were higher in patients with infarct. All the infarcts were of the lacunar type. Sixty percent of the cerebrovascular infarcts were acute in nature, 50% of these being multiple. Unilateral infarcts were seen in 70% of the patients. The most common site of infarct was the basal ganglia, others being distributed over the thalamus, frontal, temporal, parieto-occipital regions in the descending order. The presence of neurovascular involvement in the form of infarcts to the risk of morbidity and mortality had an odds ratio of 9.1 and 2.6, respectively. Conclusion Neurovascular involvement in chronic cryptococcal meningitis is a rare entity. These tend to present as multiple lacunar infarcts. Mortality and morbidity associated with these patients is higher when compared to patients who do not have infarcts. This result suggests that vascular injury plays a role in predicting outcome of patients with cryptococcal meningitis. Future studies are needed to understand the mechanism by which vascular events (infarcts) occur and result in poor outcome.

Ajay Kumar Mishra

Papers

Active segmentation with fixation

Active Visual Segmentation

Comprehensive update on current outbreak of novel coronavirus infection (2019-nCoV)

COVID-2019: update on epidemiology, disease spread and management.

Cerebrovascular injury in cryptococcal meningitis.