513 research outputs found
Augmented reality (AR) for surgical robotic and autonomous systems: State of the art, challenges, and solutions
Despite the substantial progress achieved in the development and integration of augmented reality (AR) in surgical robotic and autonomous systems (RAS), the center of focus in most devices remains on improving end-effector dexterity and precision, as well as improved access to minimally invasive surgeries. This paper aims to provide a systematic review of different types of state-of-the-art surgical robotic platforms while identifying areas for technological improvement. We associate specific control features, such as haptic feedback, sensory stimuli, and human-robot collaboration, with AR technology to perform complex surgical interventions for increased user perception of the augmented world. Current researchers in the field have, for long, faced innumerable issues with low accuracy in tool placement around complex trajectories, pose estimation, and difficulty in depth perception during two-dimensional medical imaging. A number of robots described in this review, such as Novarad and SpineAssist, are analyzed in terms of their hardware features, computer vision systems (such as deep learning algorithms), and the clinical relevance of the literature. We attempt to outline the shortcomings in current optimization algorithms for surgical robots (such as YOLO and LTSM) whilst providing mitigating solutions to internal tool-to-organ collision detection and image reconstruction. The accuracy of results in robot end-effector collisions and reduced occlusion remain promising within the scope of our research, validating the propositions made for the surgical clearance of ever-expanding AR technology in the future
Functionalized Pyrolysis Products for High Value Chemical Production
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Information and The Brukner-Zeilinger Interpretation of Quantum Mechanics: A Critical Investigation
In Brukner and Zeilinger's interpretation of quantum mechanics, information
is introduced as the most fundamental notion and the finiteness of information
is considered as an essential feature of quantum systems. They also define a
new measure of information which is inherently different from the Shannon
information and try to show that the latter is not useful in defining the
information content in a quantum object.
Here, we show that there are serious problems in their approach which make
their efforts unsatisfactory. The finiteness of information does not explain
how objective results appear in experiments and what an instantaneous change in
the so-called information vector (or catalog of knowledge) really means during
the measurement. On the other hand, Brukner and Zeilinger's definition of a new
measure of information may lose its significance, when the spin measurement of
an elementary system is treated realistically. Hence, the sum of the individual
measures of information may not be a conserved value in real experiments.Comment: 20 pages, two figures, last version. Section 4 is replaced by a new
argument. Other sections are improved. An appendix and new references are
adde
Sickle cell disease in pregnancy – a rare condition with detrimental outcome: a case report
Sickle cell disease (SCD) in pregnancy is uncommon in Malaysia. We present a case of sickle cell disease in pregnancy with maternal and fetal complications. The patient presented with acute pain crisis and hemolysis in the third trimester. Despite thromboprophylaxis, she developed deep vein thrombosis. The pregnancy was further complicated by severe pre-eclampsia and intrauterine growth restriction which require preterm caesarean section. The baby was admitted to Neonatal Intensive Care Unit due to prematurity and low birth weight. Multidisciplinary approach in managing pregnant patient with SCD is essential in achieving good obstetrics outcome
Portable Microfluidic Integrated Plasmonic Platform for Pathogen Detection
Timely detection of infectious agents is critical in early diagnosis and treatment of infectious diseases. Conventional pathogen detection methods, such as enzyme linked immunosorbent assay (ELISA), culturing or polymerase chain reaction (PCR) require long assay times, and complex and expensive instruments, which are not adaptable to point-of-care (POC) needs at resource-constrained as well as primary care settings. Therefore, there is an unmet need to develop simple, rapid, and accurate methods for detection of pathogens at the POC. Here, we present a portable, multiplex, inexpensive microfluidic-integrated surface plasmon resonance (SPR) platform that detects and quantifies bacteria, i.e., Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) rapidly. The platform presented reliable capture and detection of E. coli at concentrations ranging from ∼105 to 3.2 × 107 CFUs/mL in phosphate buffered saline (PBS) and peritoneal dialysis (PD) fluid. The multiplexing and specificity capability of the platform was also tested with S. aureus samples. The presented platform technology could potentially be applicable to capture and detect other pathogens at the POC and primary care settings. © 2015, Nature Publishing Group. All rights reserved
X-ray and MR contrast bearing nanoparticles enhance the therapeutic response of image-guided radiation therapy for oral cancer
INTRODUCTION: Radiation therapy for head and neck squamous cell carcinoma is constrained by radiotoxicity to normal tissue. We demonstrate 100 nm theranostic nanoparticles for image-guided radiation therapy planning and enhancement in rat head and neck squamous cell carcinoma models.
METHODS: PEG conjugated theranostic nanoparticles comprising of Au nanorods coated with Gadolinium oxide layers were tested for radiation therapy enhancement in 2D cultures of OSC-19-GFP-luc cells, and orthotopic tongue xenografts in male immunocompromised Salt sensitive or SS rats via both intratumoral and intravenous delivery. The radiation therapy enhancement mechanism was investigated.
RESULTS: Theranostic nanoparticles demonstrated both X-ray/magnetic resonance contrast in a dose-dependent manner. Magnetic resonance images depicted optimal tumor-to-background uptake at 4 h post injection. Theranostic nanoparticle + Radiation treated rats experienced reduced tumor growth compared to controls, and reduction in lung metastasis.
CONCLUSIONS: Theranostic nanoparticles enable preprocedure radiotherapy planning, as well as enhance radiation treatment efficacy for head and neck tumors
Two-dimensional SnS and SnSe as hosts of K-ion storage: a first-principles prediction
Potassium ion batteries (KIBs) have attracted remarkable consideration
due to their intrinsic safety and huge availability of potassium. However, the large size of
the K ion and low charge−discharge efficiency are the main obstacles to the progress of
KIBs. To overcome these hurdles, we chose SnS and SnSe monolayers as K anodes for
KIBs due to their layered structural assemblies, wider surface area to accommodate more
K content, and high thermal stabilities. First-principles simulations were carried out to
study the electronic properties and K storage capability of SnS and SnSe monolayers as
anode materials for KIBs. We found that K adsorption enhances the electrical conductivity
of both SnS and SnSe monolayers, which become metallic after the adsorption of a very
minor concentration of K. The outcomes of the ab initio molecular dynamic simulations
display the thermal stability of the host materials for KIBs. According to our calculations,
the theoretical capacities of SnS and SnSe monolayers are 355 and 271 mA h/g,
respectively. Consequently, we obtain very low average voltages of 0.45 V for SnS and 0.36
V for SnSe monolayers. In addition, the low diffusion barriers for the K-ion on SnS and SnSe monolayers are 0.14 and 0.16 eV,
correspondingly, illustrating the fast ion transfer rate with rapid potassiation and depotassiation. These intriguing results suggest that
SnS and SnSe monolayers could be promising anode materials for KIBs
On the Transmit Beamforming for MIMO Wiretap Channels: Large-System Analysis
With the growth of wireless networks, security has become a fundamental issue
in wireless communications due to the broadcast nature of these networks. In
this work, we consider MIMO wiretap channels in a fast fading environment, for
which the overall performance is characterized by the ergodic MIMO secrecy
rate. Unfortunately, the direct solution to finding ergodic secrecy rates is
prohibitive due to the expectations in the rates expressions in this setting.
To overcome this difficulty, we invoke the large-system assumption, which
allows a deterministic approximation to the ergodic mutual information.
Leveraging results from random matrix theory, we are able to characterize the
achievable ergodic secrecy rates. Based on this characterization, we address
the problem of covariance optimization at the transmitter. Our numerical
results demonstrate a good match between the large-system approximation and the
actual simulated secrecy rates, as well as some interesting features of the
precoder optimization.Comment: Published in Lecture Notes in Computer Science 8317, pp. 90-102,
2014. (Proceedings of International Conference on Information-Theoretic
Security (ICITS), Singapore, November 2013
Corrigendum to: �Novel and emerging mutations of SARS-CoV-2: Biomedical implications� Biomed. Pharmacother. 139 (2021) 111599 (Biomedicine & Pharmacotherapy (2021) 139, (S075333222100384X), (10.1016/j.biopha.2021.111599))
The authors regret the incorrect publication of affiliations of some of the authors in the original article. The correct affiliation of the authors are presented below: Elmira Mohammadia,b Fatemeh Shafieec Kiana Shahzamanid Mohammad Mehdi Ranjbare Abbas Alibakhshif Shahrzad Ahangarzadehg Leila Beikmohammadih,i Laleh Shariatij,k Soodeh Hooshmandil Behrooz Ataeim Shaghayegh HaghjooyJavanmarda a Applied Physiology Research Center, Cardiovascular Research Institute, Department of Physiology, Isfahan University of Medical Sciences, Isfahan, Iran b Core Research Facilities, Isfahan University of Medical Sciences, Isfahan, Iran c Department of Pharmaceutical Biotechnology, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran d Isfahan Gastroenterology and Hepatology Research Center (lGHRC), Isfahan University of medical sciences, Isfahan, Iran e Razi Vaccine and Serum Research Institute, Agricultural Research, Education, and Extension Organization (AREEO), Karaj, Iran f Molecular Medicine Research Center, Hamadan University of Medical Sciences, Hamadan, Iran g Infectious Diseases and Tropical Medicine Research Center, Isfahan University of Medical Sciences, Isfahan, Iran h Department of Biochemistry, Erasmus University Medical Center, Rotterdam, The Netherlands i Stem Cell and Regenerative Medicine Center of Excellence, Tehran University of Medical Sciences, 14155-6559 Tehran, Iran j Biosensor Research Center, School of Advanced Technologies in Medicine, Isfahan University of Medical Sciences, Isfahan, Iran k Department of Biomaterials, Nanotechnology and Tissue Engineering, School of Advanced Technologies in Medicine, Isfahan University of Medical Sciences, Isfahan, Iran l Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran m Nosocomial Infection Research Center, Isfahan University of Medical Sciences, Isfahan, Iran The authors would like to apologise for any inconvenience caused. © 202
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