Publications by authors named "Ali Ebrahimi"

171 Publications

Adaptive Control Improves Sclera Force Safety in Robot-Assisted Eye Surgery: A Clinical Study.

IEEE Trans Biomed Eng 2021 Apr 6;PP. Epub 2021 Apr 6.

The integration of robotics into retinal microsurgery leads to a reduction in surgeon perception of tool-to-tissue interaction forces. Tool shaft-to-sclera, and tool tip-to-surgical target, forces are rendered either markedly reduced or imperceptible to the surgeon. This blunting of human tactile sensory input is due to the inflexible mass and large inertia of the robotic arm as compared to the milli-Newton scale of the interaction forces encountered during ophthalmic surgery. The loss of human tactile feedback, as well as the comparatively high forces that are potentially imparted to the fragile tissues of the eye, identify a potential iatrogenic risk during robotic eye surgery. In this paper, we aim to evaluate two variants of an adaptive force control scheme implemented on the Steady-Hand Eye Robot (SHER) that are intended to mitigate the risk of unsafe scleral forces. The present study enrolled ten retina fellows and ophthalmology residents into a simulated procedure, which simply asked the trainees to follow retinal vessels in a model retina surgery environment, with and without robotic assistance. The study was approved by the Johns Hopkins University Institutional Review Board. For this purpose, we have developed a force-sensing (equipped with Fiber Bragg Grating (FBG)) instrument to attach to the robot. A piezo-actuated linear stage for creating random lateral motions to the eyeball phantom has been provided to simulate disturbances during surgery. The SHER and all of its dependencies were set up in an operating room in the Wilmer Eye Institute at the Johns Hopkins Hospital. The clinicians conducted robot-assisted experiments with the adaptive controls incorporated as well as freehand manipulations. The results indicate that the Adaptive Norm Control (ANC) method, is able to maintain scleral forces at predetermined safe levels better than even freehand manipulations. Novice clinicians in robot training however, subjectively preferred freehand maneuvers over robotic manipulations. Clinician preferences once highly skilled with the robot is not assessed in this study.
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http://dx.doi.org/10.1109/TBME.2021.3071135DOI Listing
April 2021

Towards Bimanual Vein Cannulation: Preliminary Study of a Bimanual Robotic System With a Dual Force Constraint Controller.

IEEE Int Conf Robot Autom 2020 May-Aug;2020:4441-4447. Epub 2020 Sep 15.

LCSR at the Johns Hopkins University, Baltimore, MD 21218 USA.

Retinal vein cannulation is a promising approach for treating retinal vein occlusion that involves injecting medicine into the occluded vessel to dissolve the clot. The approach remains largely unexploited clinically due to surgeon limitations in detecting interaction forces between surgical tools and retinal tissue. In this paper, a dual force constraint controller for robot-assisted retinal surgery was presented to keep the tool-to-vessel forces and tool-to-sclera forces below prescribed thresholds. A cannulation tool and forceps with dual force-sensing capability were developed and used to measure force information fed into the robot controller, which was implemented on existing Steady Hand Eye Robot platforms. The robotic system facilitates retinal vein cannulation by allowing a user to grasp the target vessel with the forceps and then enter the vessel with the cannula. The system was evaluated on an eye phantom. The results showed that, while the eyeball was subjected to rotational disturbances, the proposed controller actuates the robotic manipulators to maintain the average tool-to-vessel force at 10.9 mN and 13.1 mN and the average tool-to-sclera force at 38.1 mN and 41.2 mN for the cannula and the forcpes, respectively. Such small tool-to-tissue forces are acceptable to avoid retinal tissue injury. Additionally, two clinicians participated in a preliminary user study of the bimanual cannulation demonstrating that the operation time and tool-to-tissue forces are significantly decreased when using the bimanual robotic system as compared to freehand performance.
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http://dx.doi.org/10.1109/icra40945.2020.9196889DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7943036PMC
September 2020

A clinical and echocardiographic case report of carcinoid-related valvular heart disease.

Eur Heart J Case Rep 2020 Dec 6;4(6):1-4. Epub 2020 Nov 6.

Division of Cardiology, University of Alabama Birmingham, Birmingham, AL, USA.

Background: Carcinoid syndrome is a rare disease caused by malignant neuroendocrine neoplasms. When vasoactive substances enter the systemic circulation, the triad of cutaneous flushing, bronchospasm, and diarrhoea often characterize carcinoid syndrome. Rarely, carcinoid syndrome can progress to involve the cardiac system, a condition known as carcinoid heart disease, often affecting right-sided valvular structures.

Case Summary: Here, we present a case of malignant carcinoid syndrome with associated carcinoid heart disease in a 63-year-old female. The diagnosis of her dual regurgitant and stenotic valvular disease is detailed, with accompanying two- and three-dimensional echocardiographic images demonstrating the patient's complex tricuspid dysfunction.

Discussion: Carcinoid heart disease encompasses a rare but important subset of valvular dysfunction caused by circulating vasoactive substances. Diagnosis utilizing serum studies, computed tomography scans, and echocardiography can help expedite the diagnosis and treatment of such rare conditions, and assist in the avoidance of complications. Despite its relatively well-recognized clinical presentation, carcinoid syndrome and its associated heart disease still remains a challenging condition to manage and treat, often requiring the input of several subspecialties to treat the condition appropriately.
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http://dx.doi.org/10.1093/ehjcr/ytaa363DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7793036PMC
December 2020

Multi-stage screening to predict the specific anticancer activity of Ni(II) mixed-ligand complex on gastric cancer cells; biological activity, FTIR spectrum, DNA binding behavior and simulation studies.

Spectrochim Acta A Mol Biomol Spectrosc 2021 Apr 23;251:119377. Epub 2020 Dec 23.

Department of Biology, Faculty of Sciences, University of Sistan and Baluchestan, Zahedan, Iran.

The anticancer activity of a transition metal complex with [Ni(L)L]HO (where L and L were acetylacetonato (acac) and 2-aminopyridine (2-ampy), respectively) was evaluated in MKN45 cell line. Methyl thiazolyl tetrazolium (MTT) assay was performed to assess the antitumor capacity of the Ni(II) complex against gastric cancer cell line MKN45. The complexexhibited high in vitro antitumor activity against MKN45 cells with ICvalues of 1.99 μM in 48 hrs. The alterations in the structure of cellular biomolecules (proteins, lipids, carbohydrates, and especially DNA) by the Ni(II) complex were confirmed by bio spectroscopic studies. Fourier Transformed Infrared (FTIR) spectroscopy analysis revealed significant differences between untreated and treated MKN45 cell line in the region of glycogen, nucleic acid, amide I and amide II bands (1000, 1100, ~1650, and ~1577 cm). The absorption bands 1150 cm and 1020-1025 cm can be assigned to the CO bond of glycogen and other carbohydrates and are significantly overlapped by DNA. The interaction of calf thymus (CT) DNA with Ni(II) complex was explored using absorption spectral method. The UV-visible studies demonstrated that this complex was able to bind with DNA via groove, non-covalent, and electrostatic interactions, and binding constant (K) was found to be 3 * 10. Docking simulation and Non Covalent Interaction (NCI) topological analysis were conducted to provide insights into the nature of DNA/complex interactions. The binding affinity and binding stability of complex was validated by 400-ns MD simulations.
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http://dx.doi.org/10.1016/j.saa.2020.119377DOI Listing
April 2021

Snare-Assisted Delivery for Ascending Endovascular Repair of Acute Type A Dissection.

Ann Thorac Surg 2021 Jan 7. Epub 2021 Jan 7.

Division of Cardiology, Department of Internal Medicine, University of Alabama at Birmingham, Birmingham, AL.

Endovascular stenting of the ascending aorta has been described for various aortic pathologies including Type A dissection in patients who are prohibitive risk for open surgery. Endovascular treatment of ascending aortic pathology poses unique anatomic and technical challenges related to aortic morphology. Herein, we present a novel technique of endovascular ascending stent graft delivery from a transfemoral approach for treatment of an acute Type A dissection, utilizing a snare-guided deployment technique to facilitate favorable device deployment.
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http://dx.doi.org/10.1016/j.athoracsur.2020.12.027DOI Listing
January 2021

Automatic Light Pipe Actuating System for Bimanual Robot-Assisted Retinal Surgery.

IEEE ASME Trans Mechatron 2020 Dec 22;25(6):2846-2857. Epub 2020 May 22.

LCSR at the Johns Hopkins University, Baltimore, MD 21218 USA.

Retinal surgery is a bimanual operation in which surgeons operate with an instrument in their dominant hand (more capable hand) and simultaneously hold a light pipe (illuminating pipe) with their non-dominant hand (less capable hand) to provide illumination inside the eye. Manually holding and adjusting the light pipe places an additional burden on the surgeon and increases the overall complexity of the procedure. To overcome these challenges, a robot-assisted automatic light pipe actuating system is proposed. A customized light pipe with force-sensing capability is mounted at the end effector of a follower robot and is actuated through a hybrid force-velocity controller to automatically illuminate the target area on the retinal surface by pivoting about the scleral port (incision on the sclera). Static following-accuracy evaluation and dynamic light tracking experiments are carried out. The results show that the proposed system can successfully illuminate the desired area with negligible offset (the average offset is 2.45 mm with standard deviation of 1.33 mm). The average scleral forces are also below a specified threshold (50 mN). The proposed system not only can allow for increased focus on dominant hand instrument control, but also could be extended to three-arm procedures (two surgical instruments held by surgeon plus a robot-holding light pipe) in retinal surgery, potentially improving surgical efficiency and outcome.
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http://dx.doi.org/10.1109/tmech.2020.2996683DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7745739PMC
December 2020

A batch study on the adsorption/desorption behavior of vancomycin on bentonite nanoparticles in aqueous solutions.

Water Sci Technol 2020 Dec;82(11):2603-2612

Department of Civil Engineering, Shahrood University of Technology, Shahrood, Iran E-mail:

In this study, adsorption/desorption of vancomycin (VAN) on bentonite nanoparticles was investigated in a batch system. Adsorption experiments were carried out as a function of several influential parameters such as adsorbent dosage, pH, contact time and ionic strength. Bentonite nanoparticles were characterized by field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, Brunauer-Emmett-Teller, and Fourier transform infrared (FTIR) analyses and the mesoporous structure was revealed. Langmuir, Freundlich, and Temkin isotherm models were applied for the examination of equilibrium data, and Langmuir was found to be the best fit. With the increase in pH and ionic strength, the adsorption capacity decreases, which suggests the adsorption process may be dominated by the cation exchange mechanism. Moreover, VAN desorption from bentonite nanoparticles in two initial VAN loadings was investigated under different concentrations of metallic cations of various valences (Na, Ca, Al), and pHs 3-10. Desorption was strongly pH-dependent and the amount of VAN desorbed increased with increasing cations concentrations. The FTIR analysis before and after VAN desorption suggests that the formation of Al-VAN and Ca-VAN complexes on the solid surface and then their detachment from the solid surface may contribute to the higher VAN desorption by Al and Ca.
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http://dx.doi.org/10.2166/wst.2020.499DOI Listing
December 2020

Appropriate time to apply control input to complex dynamical systems.

Sci Rep 2020 12 16;10(1):22035. Epub 2020 Dec 16.

Laboratory of Systems Biology and Bioinformatics (LBB), Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.

Controlling a network structure has many potential applications many fields. In order to have an effective network control, not only finding good driver nodes is important, but also finding the optimal time to apply the external control signals to network nodes has a critical role. If applied in an appropriate time, one might be to control a network with a smaller control signals, and thus less energy. In this manuscript, we show that there is a relationship between the strength of the internal fluxes and the effectiveness of the external control signal. To be more effective, external control signals should be applied when the strength of the internal states is the smallest. We validate this claim on synthetic networks as well as a number of real networks. Our results may have important implications in systems medicine, in order to find the most appropriate time to inject drugs as a signal to control diseases.
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http://dx.doi.org/10.1038/s41598-020-78909-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7744535PMC
December 2020

Evaluating changes in microbial population and earthworms weight during vermicomposting of cow manure containing co-trimoxazole.

J Environ Health Sci Eng 2020 Dec 21;18(2):403-412. Epub 2020 Sep 21.

Environmental Science and Technology Research Center, Department of Waste Management, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, 8915173160 Iran.

Background: Transmission of pathogens such as fecal coliforms is regarded as a significant concern about using livestock manure in agricultural applications.

Purpose: The aim of this study was to evaluate the effects of vermicomposting on fecal coliforms in cow manure containing co-trimoxazole as a widely used drug for cow diseases in animal husbandry.

Methods: Adaptation process of earthworms was carried out in two phases for 6 weeks; then, the main process was fulfilled in 9 weeks. The final weight of cow manure per reactor was 3.5 kg. 120 g of earthworms added to each reactor (approximately 280-300 numbers in the reactor). Co-trimoxazole was also prepared with a purity of 99% from Pakdarou Co., Iran, and added to the reactors at concentrations of 10, 20, 50, and100mg/kg. Organic carbon, total Kjeldahl nitrogen (TKN), carbon-to-nitrogen (C:N) ratio, as well as phosphorus content of the reactors were measured. Fecal coliforms and parasite eggs were counted using standard laboratory methods (i.e. the Iranian Compost Standard) for 8 weeks.

Results: The results revealed a decrease in organic carbon, C:N ratio, and co-trimoxazole content but a rising trend in TKN and phosphorus levels. The weight of earthworms also increased at the end of the process in all reactors, except for one case. A significant reduction was observed in fecal coliforms and parasite eggs at the end of the vermicomposting.

Conclusions: According to the results, earthworms could be active in cow manure vermicomposting including 10-100 mg/kg concentration of co-trimoxazole antibiotic. The vermicomposting seems to be an effective method for reducing fecal coliforms and parasites in cow manure. As well, co-trimoxazole in common concentration could not have any effects on the ability of earthworms. At the end of the vermicomposting, all parameters were placed within the ICS (National) - Grade 1.
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http://dx.doi.org/10.1007/s40201-019-00404-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7721917PMC
December 2020

Developing a colorimetric nucleic acid-responsive DNA hydrogel using DNA proximity circuit and catalytic hairpin assembly.

Anal Chim Acta 2020 Nov 2;1137:1-10. Epub 2020 Sep 2.

Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran.

The development of powerful techniques for sensitive detection of nucleic acids has attracted much attention for fabricating accurate biosensors in various fields, such as genomics, clinical diagnostics, and forensic sciences. Up to now, different systems have been introduced, the majority of which are expensive, time-consuming, and relatively low selectivity/limit of detection. These limitations caught our attention to fabricate a nucleic acid responsive system by combining three layers of signal amplification strategy, namely a split proximity circuit (SPC), a catalytic hairpin assembly (CHA), and a DNA hydrogel. Herein, by SPC operation, two initiators and a target strand were assembled and activated the CHA reaction in the presence of three 5'-cytosine (C)-rich hairpins. Then, produced C-rich embedded three-way junction structures could form i-motif structures under acidic environment followed by a transition from sol to gel state. To acquire a quantitative and colorimetric measurement, gold nanoparticles (GNPs) were used that encapsulated and sediment by the gel formation. The resulting platform detected the target with a limit of detection of 1 pM and considerable selectivity.
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http://dx.doi.org/10.1016/j.aca.2020.08.059DOI Listing
November 2020

Is there a relationship between homes' radon gas of MS and non-MS individuals, and the patients' paraclinical magnetic resonance imaging and visually evoked potentials in Yazd-Iran?

Environ Sci Pollut Res Int 2021 Feb 19;28(7):8907-8914. Epub 2020 Oct 19.

Environmental Science and Technology Research Center, Department of Environmental Health Engineering, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.

Long-term inhalation of radon gas can cause harm to humans and lead to many diseases. One of these diseases is multiple sclerosis (MS), the most common chronic disease of the central nervous system, which alters the brain structure and impedes the rapid transmission of nerve signals throughout the neuron system. Therefore, this study aimed to investigate the relationship of the radon gas concentration in residential homes of MS and non-MS individuals with their results of paraclinical MRI and VEP in Yazd City, Iran. The radon gas concentration was measured in residential homes of 44 people with MS and 100 healthy people. To this end, the questionnaire of radon gas monitoring in residential buildings was administered, and the radon gas concentration was measured by CR-39 detectors. The mean radon concentrations in the homes of MS and non-MS people were 69.51 and 70.83, respectively. A significant positive relationship was found between radon concentration and building's age (P = 0.038). Furthermore, radon concentration had a significant inverse relationship with the building's ventilation (P = 0.053) and cooling systems (P = 0.021). No significant relationship was observed between total radon concentration and MS incidence (P = 0.88). Moreover, no significant correlation was found between radon concentration and location of the plaque in MRI test results of the patients. However, it showed an inverse non-significant correlation with the plaque's number (r = - 0.12, P = 0.42). Further studies in this area are recommended.
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http://dx.doi.org/10.1007/s11356-020-10580-yDOI Listing
February 2021

Multiplex monitoring of Alzheimer associated miRNAs based on the modular logic circuit operation and doping of catalytic hairpin assembly.

Biosens Bioelectron 2020 Dec 8;170:112710. Epub 2020 Oct 8.

Neuroscience Research Center, Kerman University of Medical Sciences, Kerman, Iran. Electronic address:

In recent years, DNA logic gates have been extensively applied in developing multiplex processing platforms to provide an accurate decision on the diagnosis of multi-factor diseases. In this work, we presented a new cascaded logical operator by combining different modules for computational monitoring of four miRNAs related to Alzheimer disease (has-miR-143-3p, has-miR-18b-5p, has-miR-424-5p, and has-miR-93-5p). Herein, three sequential logic gates were programed that upon entering the miRNA inputs, delivered the trigger strand of CHA (catalytic hairpin assembly) reaction through a cyclic amplification. Afterward, the product of the CHA reaction, three-way junction, could induce the gold nanoparticles aggregation. This phenomenon led to generate a blue color of the solution that enabled visualizing and quantitative measurement of the assay. The output signals were recorded through reading the absorbance intensity transition, dynamic light scattering (DLS), and transmission electron microscopy (TEM). Taken together, the proposed assay by taking advantage of excellent generality, naked eye observation, the 4-plex detection, simplicity, enzyme-free nature, and two-steps process without any immobilization and washing has addressed the limitation of the previous systems. Moreover, the amplified monitoring of low-abundant of target miRNAs was accomplished with a limit of detection as low as 5 pM.
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http://dx.doi.org/10.1016/j.bios.2020.112710DOI Listing
December 2020

Scleral Force Evaluation During Vitreoretinal Surgery: in an In Vivo Rabbit Eye Model.

Annu Int Conf IEEE Eng Med Biol Soc 2020 07;2020:6049-6053

During vitreoretinal surgery, the surgeon is required to precisely manipulate multiple tools in a confined intraocular environment, while the tool tip to retina contact forces are at the limit of human sensation limits. During typical vitrectomy procedures, the surgeon inserts various tools through small incisions performed on the sclera of the eye (sclerotomies), and manipulates them to perform surgical tasks. During intraocular procedures, tool-tissue interactions occur at the sclerotomy ports and at the tool-tip when it contacts retina. Measuring such interactions may be valuable for providing force feedback necessary for robotic guidance. In this paper, we measure and analyze force measurements at the sclerotomy ports. To the best of our knowledge, this is the first time that the scleral forces are measured in an in vivo eye model. A force sensing instrument utilizing Fiber Bragg Grating (FBG) strain sensors was used to measure the scleral forces while two retinal surgeons performed intraocular tool manipulation (ITM) task in rabbit eyes as well as a dry phantom. The mean of the measured sclera forces were 129.11 mN and 80.45 mN in in vivo and dry phantom experiments, respectively.
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http://dx.doi.org/10.1109/EMBC44109.2020.9176402DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7538654PMC
July 2020

Robotic Retinal Surgery Impacts on Scleral Forces: In Vivo Study.

Transl Vis Sci Technol 2020 09 1;9(10). Epub 2020 Sep 1.

Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD, USA.

Purpose: This study aims to map force interaction between instrument and sclera of in vivo rabbits during retinal procedures, and verify if a robotic active force control could prevent unwanted increase of forces on the sclera.

Methods: Experiments consisted in the performance of intraocular movements of a force sensing instrument, adjacent to the retinal surface, in radial directions, from the center to the periphery and back, and compared manual manipulations with robotic assistance and also robotic assistance with an active force control. This protocol was approved by the Animal Use and Ethical Committee and experiments were according to ARVO Statement of Animal Use.

Results: Mean forces using manual manipulations were 115 ± 51 mN. Using robotic assistance, mean forces were 118 ± 49 mN. Using an active force control method, overall mean forces reduced to 69 ± 15, with a statistical difference compared with other methods ( < 0.001). Comparing intraocular directions, superior sector required higher forces and the force control method reduced differences in forces between users and retained the same force pattern between them.

Conclusions: Results validate that the introduction of robotic assistance might increase the dynamic interactions between instrument and sclera, and the addition of an active force control method reduces the forces at levels lower than manual manipulations.

Translational Relevance: All marketing benefits from extreme accuracy and stability from robots, however, redundancy of safety mechanisms during intraocular manipulations, especially on force control and surgical awareness, would allow all utility of robotic assistance in ophthalmology.
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http://dx.doi.org/10.1167/tvst.9.10.2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7476674PMC
September 2020

Target controllability with minimal mediators in complex biological networks.

Genomics 2020 11 6;112(6):4938-4944. Epub 2020 Sep 6.

Laboratory of Systems Biology and Bioinformatics (LBB), Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran. Electronic address:

Controllability of a complex network system is related to finding a set of minimum number of nodes, known as drivers, controlling which allows having a full control on the dynamics of the network. For some applications, only a portion of the network is required to be controlled, for which target control has been proposed. Often, along the controlling route from driver nodes to target nodes, some mediators (intermediate nodes) are also unwillingly controlled, which might cause various side effects. In controlling cancerous cells, unwillingly controlling healthy cells, might result in weakening them, thus affecting the immune system against cancer. This manuscript proposes a suitable candidate solution to the problem of finding minimum number of driver nodes under minimal mediators. Although many others have attempted to develop algorithms to find minimum number of drivers for target control, the newly proposed algorithm is the first one that is capable of achieving this goal and at the same time, keeping the number of the mediators to a minimum. The proposed controllability condition, based on path lengths between node pairs, meets Kalman's controllability rank condition and can be applied on directed networks. Our results show that the path length is a major determinant of in properties of the target control under minimal mediators. As the average path length becomes larger, the ratio of drivers to target nodes decreases and the ratio of mediators to targets increases. The proposed methodology has potential applications in biological networks. The source code of the algorithm and the networks that have been used are available from the following link: https://github.com/LBBSoft/Target-Control-with-Minimal-Mediators.git.
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http://dx.doi.org/10.1016/j.ygeno.2020.09.003DOI Listing
November 2020

High-Sensitivity and High-Speed Single-Particle Inductively Coupled Plasma Spectrometry with the Conical Torch.

Anal Chem 2020 09 14;92(17):11786-11794. Epub 2020 Aug 14.

Department of Mechanical and Industrial Engineering, University of Toronto, Toronto M5S 3G8, Canada.

Significant advancement has been achieved in single-particle analysis with the new conical ICP torch in terms of sensitivity, precision, and throughput. Monodisperse desolvated particles of eight elements (Na, Al, Ag, Sr, Ca, Mg, Fe, and Be) were injected into the conical torch, and signal peak characteristics, precision, and kinetics of atomization and ionization were investigated with optical spectrometry. A particle introduction system was designed to ensure a smooth and uninterrupted delivery of desolvated particles to the plasma. The important finding is that, compared with the conventional Fassel torch, the conical torch offers a 1.5-8 times higher peak intensity, a 2-4 times higher peak area, a 2 times shorter peak width, and higher precision (i.e., a 1.5 times lower RSD for peak intensity and a 1.8 times lower RSD for peak width on average). Also, mass detection limits were found to be similar or up to 8 times lower (i.e., 2 times lower diameter detection limit) for the conical torch. The results indicate that these features are due to a much higher electron density, excitation temperature, and robustness which, together with an improved particle trajectory, lead to rapid vaporization/atomization/ionization of particles with minimized atom/ion cloud diffusion. Finally, the torch was demonstrated to be capable of analyzing single particles at a rate of at least 2000 particles per second with high sensitivity and precision. On the basis of these results, the conical torch is expected to bring about new possibilities in ICP-based single-particle analysis.
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http://dx.doi.org/10.1021/acs.analchem.0c01903DOI Listing
September 2020

Outcome of staged excision with pathologic margin control in high-risk basal cell carcinoma of the head region.

An Bras Dermatol 2020 Sep - Oct;95(5):583-588. Epub 2020 Jul 12.

Department of Pathology, Kermanshah University of Medical Sciences, Kermanshah, Iran.

Background: High-risk basal cell carcinoma involves a significant rate of basal cell carcinoma that requires Mohs micrographic surgery for definitive treatment. Staged excision with pathologic margin control is a simple, accessible, and curative procedure suggested for the treatment of high-risk basal cell carcinoma.

Objective: To evaluate the results of staged excision of high-risk basal cell carcinoma in the head region.

Methods: This interventional study was performed on patients with high-risk basal cell carcinoma, who underwent staged excision until the margins were free of tumor.

Results: A total of 122 patients (47 females and 75 males) with mean age of 57.66 ± 9.13 years were recruited in this study. Nasal and nodular types were the most common of both clinical and pathologic forms, respectively. Further, 89.3 % of cases were cured by staged excision after four years of follow-up. There was a significant relationship between treatment outcomes and recurrent lesions, multiplicity of risk factors, long-standing disease, and pathologic type. There was also a significant association between the number of surgical excisions and multiplicity of risk factors, as well as recurrence, location, and size of basal cell carcinoma.

Study Limitations: Lack of magnetic resonance imaging assessment in cases of suspected perineural invasion.

Conclusions: High-risk basal cell carcinoma had a high cure rate by staged excision. Patients with more risk factors and those with nasal and recurrent basal cell carcinoma required more staged excisions. Failure of treatment is more probable in patients with more risk factors, long-standing lesions, and high-risk pathologic and recurrent basal cell carcinomas.
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http://dx.doi.org/10.1016/j.abd.2020.02.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7563009PMC
November 2020

COVID-19 and psoriasis: biologic treatment and challenges.

J Dermatolog Treat 2020 Jul 6:1-5. Epub 2020 Jul 6.

Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran.

There is concern about susceptibility of psoriatic patients on biologics to coronavirus disease 2019 (COVID-19) and its clinical course. The aims of present review were to determine whether the biologic treatment of psoriasis increases the risk of SARS-CoV-2 infection and if biologics affect the clinical course of COVID-19 in these patients. We searched database of MEDLINE (PubMed) for key term of psoriasis biologic and COVID-19 until June 9, 2020 and all published 14 papers and an experience from Iran (10509 cases) related to the psoriatic patients on biologics and COVID-19 along with relevant papers were summarized. In spite of limitation in some reports, due to some of strengths that will be discussed, all papers were included in this review. According to 8769 medical reports around 0.3% of psoriatic patients had COVID-19 and the rate of hospitalization was 0.1%. No death due to COVID-19 was reported among 10509 patients. Reports indicated psoriatic patients on biologics were not more susceptible to COVID-19 and the severe clinical course of disease. While there is not definitive controlled trial data, the available evidence suggests that patients with psoriasis without COVID-19 can continue the biologic therapy for psoriasis.
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http://dx.doi.org/10.1080/09546634.2020.1789051DOI Listing
July 2020

On Calculating the Bending Modulus of Lipid Bilayer Membranes from Buckling Simulations.

J Phys Chem B 2020 07 13;124(29):6299-6311. Epub 2020 Jul 13.

University of Lyon, CNRS, Molecular Microbiology and Structural Biochemistry (MMSB, UMR 5086), F-69007 Lyon, France.

The bending modulus is an important physical constant characterizing lipid membranes. Different methods have been devised for calculating the bending modulus from simulations, and one of them, named the buckling method, is nowadays widely used due to its simplicity and numerical stability. However, questions remain on the reproducibility, finite size effects, and interpretation of results on lipid mixtures. Here we explore the dependence of simulation results on the system size and the strain. We find that the dimensions of the box have a negligible impact on the results when the system size is beyond a certain threshold. We then calculate the bending rigidity for of a series of common single-component lipid bilayers (PC, PS, PE, PG, and SM), as well as a number of binary and ternary lipid mixtures. We find that bending moduli of lipid mixtures can be predicted from the weighted average of the moduli of the individual components, as long as the mixture is homogeneous. For phase-separated mixtures, the apparent elastic modulus is closer to the value of the softer component. Predictions of the bending modulus based on the area compressibility modulus are found to be generally unreliable.
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http://dx.doi.org/10.1021/acs.jpcb.0c04253DOI Listing
July 2020

A comparison of effectiveness and cosmetic outcome of two methods for ingrown toenail: partial nail matricectomy using CO2 laser versus lateral nail fold excision.

Acta Dermatovenerol Alp Pannonica Adriat 2020 Jun;29(2):51-54

School of Medicine, Student Research Committee, Kermanshah University of Medical Sciences (KUMS), Kermanshah, Iran.

Background: Ingrown toenail (IGT) is a common nail disorder that causes discomfort and interferes with most activities. Most cases of IGT require procedural intervention. This study was performed to compare the treatment and cosmetic outcome of partial nail matricectomy (PNM) using CO2 laser versus lateral nail fold excision (LNFE).

Method: This interventional study was performed on 127 patients with IGT that were randomized into two groups. Demographic data, clinical characteristics, and treatment results were recorded in both groups.

Results: Sixty-two patients with a mean age of 28.23 ± 11.34 years were subjected to PNM and 65 patients with a mean age of 28.92 ± 9.63 years to LNFE. The PNM versus LNFE groups had cure rates of 85.5% versus 78.5%, fair cosmetic outcomes of 67.9% versus 84.0%, and infection rates of 4.8% versus 3.1%. The mean time of pain duration, return to daily activity, and return to work were nearly 3, 4, and 13 days, respectively, in both groups.

Conclusion: The treatment outcome was slightly better in the PNM group than in the LNFE group, and vice-versa for the cosmetic outcome. There were nearly similar outcomes in terms of the mean time of repair, pain duration, return to daily activity, and infection rate using both methods.
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June 2020

Cardiac Function and Sudden Cardiac Death in Heart Failure With Preserved Ejection Fraction (from the TOPCAT Trial).

Am J Cardiol 2020 08 15;129:46-52. Epub 2020 May 15.

Division of Cardiovascular Disease and Comprehensive Cardiovascular Center, University of Alabama at Birmingham, Alabama; Division of Molecular Imaging and Therapeutics, University of Alabama at Birmingham, Alabama. Electronic address:

Patients with heart failure with preserved ejection fraction (HFpEF) have a significantly elevated risk of sudden cardiac death (SCD). However, few imaging data have been correlated to this risk. We evaluated the value of multiple echocardiographic markers of left ventricular (LV) function to predict SCD in HFpEF patients. The Treatment of Heart Failure with Preserved Ejection Fraction with Aldosterone Trial (TOPCAT)-Americas cohort was used to evaluate the echocardiographic predictors of SCD and/or aborted cardiac arrest (SCD/ACA). A retrospective cohort design was used. Cox proportional hazards and Poisson regression models were used to determine the associations between the risk of SCD/ACA and echocardiographic parameters: diastolic dysfunction grade, left ventricle ejection fraction, and LV global longitudinal strain (GLS) during follow-up. Impaired left ventricle ejection fraction and GLS were associated with SCD/ACA in univariate models (p = 0.007 and 0.002, respectively), but not diastolic function grade. After multivariate adjustment, only GLS remained a significant predictor of the incidence rate of SCD/ACA (p = 0.006). There was a 58% increase in the hazard of incident SCD/ACA for every 1 unit increase in GLS (1.58, 95%CI: 1.12 to 2.22, p = 0.009). These findings remained robust in the competing risk analyses. In conclusion, amongst the multiple echocardiographic parameters of LV function, GLS may help prognosticate the risk of SCD/ACA in HFpEF patients.
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http://dx.doi.org/10.1016/j.amjcard.2020.04.038DOI Listing
August 2020

Towards securing the sclera against patient involuntary head movement in robotic retinal surgery.

ROMAN 2019 Oct 13;2019. Epub 2020 Jan 13.

Laboratory for Computational Sensing and Robotics at the Johns Hopkins University, Baltimore, MD 21218 USA.

Retinal surgery involves manipulating very delicate tissues within the confined area of eyeball. In such demanding practices, patient involuntary head movement might abruptly raise tool-to-eyeball interaction forces which would be detrimental to eye. This study is aimed at implementing different force control strategies and evaluating how they contribute to attaining sclera force safety while patient head drift is present. To simulate patient head movement, a piezoelectric-actuated linear stage is used to produce random motions in a single direction in random time intervals. Having an eye phantom attached to the linear stage then an experienced eye surgeon is asked to manipulate the eye and repeat a mock surgical task both with and without the assist of the Steady-Hand Eye Robot. For the freehand case, warning sounds were provided to the surgeon as auditory feedback to alert him about excessive slclra forces. For the robot-assisted experiments two variants of an adaptive sclera force control and a virtual fixture method were deployed to see how they can maintain eye safety under head drift circumstances. The results indicate that the developed robot control strategies are able to compensate for head drift and keep the sclera forces under safe levels as well as the free hand operation.
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http://dx.doi.org/10.1109/ro-man46459.2019.8956341DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7301640PMC
October 2019

Toward Improving Patient Safety and Surgeon Comfort in a Synergic Robot-Assisted Eye Surgery: A Comparative Study.

Rep U S 2019 Nov 27;2019:7075-7082. Epub 2020 Jan 27.

Laboratory for Computational Sensing and Robotics at the Johns Hopkins University, Baltimore, MD, 21218, USA.

When robotic assistance is present into vitreoretinal surgery, the surgeon will experience reduced sensory input that is otherwise derived from the tool's interaction with the eye wall (sclera). We speculate that disconnecting the surgeon from this sensory input may increase the risk of injury to the eye and affect the surgeon's usual technique. On the other hand, robot autonomous motion to enhance patient safety might inhibit the surgeons tool manipulation and diminish surgeon comfort with the procedure. In this study, to investigate the parameters of patient safety and surgeon comfort in a robot-assisted eye surgery, we implemented three different approaches designed to keep the scleral force in a safe range during a synergic eye manipulation task. To assess the surgeon comfort during these procedures, the amount of interference with the surgeons usual maneuvers has been analyzed by defining quantitative comfort metrics. The first two utilized scleral force control approaches are based on an adaptive force control method in which the robot actively counteracts any excessive force on the sclera. The third control method is based on a virtual fixture approach in which a virtual wall is created for the surgeon in the unsafe directions of manipulation. The performance of the utilized approaches was evaluated in user studies with two experienced retinal surgeons and the outcomes of the procedure were assessed using the defined safety and comfort metrics. Results of these analyses indicate the significance of the opted control paradigm on the outcome of a safe and comfortable robot-assisted eye surgery.
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http://dx.doi.org/10.1109/IROS40897.2019.8967806DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7260395PMC
November 2019

Sclera Force Evaluation During Vitreoretinal Surgeries in Ex Vivo Porcine Eye Model.

Proc IEEE Sens 2019 Oct 13;2019. Epub 2020 Jan 13.

Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD USA-21218.

Vitreoretinal surgery is among the most challenging microsurgical procedures as it requires precise tool manipulation in a constrained environment, while the tool-tissue interaction forces are at the human perception limits. While tool tip forces are certainly important, the scleral forces at the tool insertion ports are also important. Clinicians often rely on these forces to manipulate the eyeball position during surgery. Measuring sclera forces could enable valuable sensory input to avoid tissue damage, especially for a cooperatively controlled robotic assistant that otherwise removes the sensation of these familiar intraoperative forces. Previously, our group has measured sclera forces in phantom experiments. However, to the best of our knowledge, there are no published data measuring scleral forces in biological eye models. In this paper, we measured sclera forces in porcine eye model. A Fiber Bragg Grating (FBG) based force sensing instrument with a diameter of ~900 m and a resolution of ~1 mN was used to measure the forces while the clinician-subject followed retinal vessels in manual and robot-assisted modes. Analysis of measured forces show that the average sclera force in manual mode was 133.74 mN while in robot-assisted mode was 146.03 mN.
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http://dx.doi.org/10.1109/SENSORS43011.2019.8956820DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7261516PMC
October 2019

Correction to: Improved degradation of n-hexane vapours using a hybrid system, a photoreactor packed with TiO coated-scoria granules and a multilayer biofilter.

J Environ Health Sci Eng 2020 Jun 27;18(1):379-380. Epub 2020 Jan 27.

2Department of Environmental Health Engineering, Faculty of Health, Environmental Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran.

[This corrects the article DOI: 10.1007/s40201-019-00416-4.].
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http://dx.doi.org/10.1007/s40201-020-00451-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7203376PMC
June 2020

Sclera Force Control in Robot-assisted Eye Surgery: Adaptive Force Control vs. Auditory Feedback.

Int Symp Med Robot 2019 Apr 9;2019. Epub 2019 May 9.

Department of Mechanical Engineering and Laboratory for Computational Sensing and Robotics at the Johns Hopkins University, Baltimore, MD 21218 USA.

Surgeon hand tremor limits human capability during microsurgical procedures such as those that treat the eye. In contrast, elimination of hand tremor through the introduction of microsurgical robots diminishes the surgeons tactile perception of useful and familiar tool-to-sclera forces. While the large mass and inertia of eye surgical robot prevents surgeon microtremor, loss of perception of small scleral forces may put the sclera at risk of injury. In this paper, we have applied and compared two different methods to assure the safety of sclera tissue during robot-assisted eye surgery. In the active control method, an adaptive force control strategy is implemented on the Steady-Hand Eye Robot in order to control the magnitude of scleral forces when they exceed safe boundaries. This autonomous force compensation is then compared to a passive force control method in which the surgeon performs manual adjustments in response to the provided audio feedback proportional to the magnitude of sclera force. A pilot study with three users indicate that the active control method is potentially more efficient.
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http://dx.doi.org/10.1109/ISMR.2019.8710205DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7198062PMC
April 2019

Adaptive Control of Sclera Force and Insertion Depth for Safe Robot-Assisted Retinal Surgery.

IEEE Int Conf Robot Autom 2019 May 12;2019:9073-9079. Epub 2019 Aug 12.

Department of Mechanical Engineering and Laboratory for Computational Sensing and Robotics at the Johns Hopkins University, Baltimore, MD 21218 USA.

One of the significant challenges of moving from manual to robot-assisted retinal surgery is the loss of perception of forces applied to the sclera (sclera forces) by the surgical tools. This damping of force feedback is primarily due to the stiffness and inertia of the robot. The diminished perception of tool-to-eye interactions might put the eye tissue at high risk of injury due to excessive sclera forces or extreme insertion of the tool into the eye. In the present study therefore a 1-dimensional adaptive control method is customized for 3-dimensional control of sclera force components and tool insertion depth and then implemented on the velocity-controlled Johns Hopkins Steady-Hand Eye Robot. The control method enables the robot to perform autonomous motions to make the sclera force and/or insertion depth of the tool tip to follow pre-defined desired and safe trajectories when they exceed safe bounds. A robotic light pipe holding application in retinal surgery is also investigated using the adaptive control method. The implementation results indicate that the adaptive control is able to achieve the imposed safety margins and prevent sclera forces and insertion depth from exceeding safe boundaries.
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http://dx.doi.org/10.1109/ICRA.2019.8793658DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7198060PMC
May 2019

The emergence of the hypervirulent Klebsiella pneumoniae (hvKp) strains among circulating clonal complex 147 (CC147) harbouring bla carbapenemases in a tertiary care center of Iran.

Ann Clin Microbiol Antimicrob 2020 Mar 31;19(1):12. Epub 2020 Mar 31.

Microbiology Department, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran.

Background: Klebsiella pneumoniae is a public health concern because of its ability to develop multidrug resistance and hypervirulent genotypes, of those capsular types K1 and K2 cause community and nosocomial life-threatening infections. This study aimed to determine the antibiotic susceptibility patterns and genotypic traits of a collection of Klebsiella spp. isolates. Furthermore, the clonal relatedness of bla producing strains was investigated.

Methods: During a 19-months  surveillance study, 122 Klebsiella spp. isolates were cultured from extraintestinal specimens of patients admitted to the tertiary referral hospital in Semnan, Iran. Isolates were identified using biochemical tests and subjected to determination of phylogroups, capsular types and virulence/resistance genes content. Hypervirulent K. pneumoniae (hvKp) strains were detected genotypically, and Enterobacterial Repetitive Intergenic Consensus (ERIC)-PCR fingerprinting was used to determine the clonality of bla producing strains.

Results: Multidrug resistant phenotype was detected in 75 (61.5%) isolates and amikacin was found as the most potent antibiotic with the susceptibility rate of 85.2%. The carbapenemase genes were detected in 45 (36.8%) strains, including 21 (17.2%) bla, 7 (5.6%) bla, 14 (11.4%) bla and 3 (2.4%) bla carrying strains, while 55 (45.08%) isolates showed carbapenem resistant phenotype. The first bla carrying strain was cultured from a sputum specimen on March 2015, while the last positive one was recovered from blood culture on September 2016. Most of the isolates (80.3%) belonged to phylogroup I, and bla was identified among all three phylogroups. The ERIC-PCR clustered the 101 bla negative and 21 bla positive isolates into 25 and five clusters, respectively, and the latter group belonged to clonal complex 147 (CC147). One K1 and 15 K2 bla negative isolates were detected, of those three strains were identified as hvKp. Five K2 positive strains, including four bla producer and one hvKp sequence type 86 (ST86) were carbapenem resistant. Among carbapenem resistant isolates, CC147 strains harboured higher rates of siderophores iutA and ybtS.

Conclusion: The present findings showed a hospital circulation of CC147 bla or bla producing strains, disseminated in different wards. The hvKp/ST86 strain expressing K2 capsular type and carbapenem resistant phenotype wasn't reported from Iran so far. So, it seems that we must be aware of the emergence and spread of new K. pneumoniae clones associated with resistant and hypermucoviscous phenotypes.
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http://dx.doi.org/10.1186/s12941-020-00349-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7110786PMC
March 2020

Association between CYP19A

Int J Mol Cell Med 2019 20;8(2):162-168. Epub 2019 Jul 20.

Department of Internal Medicine, Medical School, Kermanshah University of Medical Sciences, Kermanshah, Iran.

Acne vulgaris (AV) is a common skin disease that causes physical and psychological problems for the affected individual. In addition to systemic changes in hormone levels, overproduction of local steroids, especially androgens are associated with AV. Cytochrome (CYP) 19 is involved in the synthesis of estrogens. The aim of the present study was to investigate the influence of CYP19A
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http://dx.doi.org/10.22088/IJMCM.BUMS.8.2.162DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7081083PMC
July 2019

Structural insights for rational design of new PIM-1 kinase inhibitors based on 3,5-disubstituted indole derivatives: An integrative computational approach.

Comput Biol Med 2020 03 1;118:103641. Epub 2020 Feb 1.

Department of Clinical Biochemistry, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran.

Proviral integration Moloney virus (PIM) 1, 2, and 3 kinases are a family of constitutively active serine/threonine kinases that are involved in a number of signaling pathways important to cancer cells. Their overexpression in a variety of human hematopoietic malignancies and solid tumors suggest that inhibition of PIM signaling could provide patients with therapeutic benefit. In this study, a series of 3,5-disubstituted indole derivatives have been systematically studied using three-dimensional quantitative structure-activity relationship (3D-QSAR) analysis, molecular docking simulation, and partial least-squares (PLS) analysis methods to explore the influence of the structural characteristics on the inhibitory activity and use them to propose novel bioactive molecules. The comparative molecular field and comparative molecular similarity indices analyses (CoMFA and CoMSIA) models exhibited a good correlation between the predicted and experimental activities with excellent predictive capability and yielded statistically reliable value (CoMFA: Q = 0.535, R = 0.987, r = 0.909; CoMSIA: Q = 0.785, R = 0.989, r = 0.969). Based on the CoMFA and CoMSIA models and docking results, ten novel potent PIM-1 inhibitors (N1-N10) have been designed and the molecular models have validated their inhibitory activities. These results provided strong theoretical guidance for the development of novel PIM-1 inhibitors.
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http://dx.doi.org/10.1016/j.compbiomed.2020.103641DOI Listing
March 2020