28,744 results match your criteria good mechanical


Femoral Head Perforation After Primary Hip Arthroplasty: Unseen Complication of Ceramic-on-Ceramic Interface: A Case Report.

JBJS Case Connect 2021 07 28;11(3). Epub 2021 Jul 28.

Orthopaedics and Traumatology Department, Medical Park Hospital Samsun, Samsun, Turkey.

Case: A 33-year-old woman, who underwent bilateral ceramic-on-ceramic total hip arthroplasty 3 years previously, presented with right groin pain and mechanical grinding without a history of trauma. Radiographs revealed luxation of the femoral head, and computerized tomography showed perforation of the ceramic femoral head. The patient underwent revision with a metal-on-polyethylene articulation and retained femoral stem. Read More

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17.6%-Efficient Quasiplanar Heterojunction Organic Solar Cells from a Chlorinated 3D Network Acceptor.

Adv Mater 2021 Jul 28:e2102778. Epub 2021 Jul 28.

Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China.

Bulk heterojunction (BHJ) organic solar cells (OSCs) have achieved great success because they overcome the shortcomings of short exciton diffusion distances. With the progress in material innovation and device technology, the efficiency of BHJ devices is continually being improved. For some special photovoltaic material systems, it is difficult to manipulate the miscibility and morphology of blend films, and this results in moderate, even poor device performance. Read More

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Experimental Research of Drying Characteristic of Red Banana in a Single Slope Direct Solar Dryer Based on Natural and Forced Convection.

Food Technol Biotechnol 2021 Jun;59(2):137-146

Department of Mechanical Engineering, National Institute of Technology Puducherry, 609609 Karaikal.

Research Background: Traditionally, open sun drying method serves to dry the products for long time preservation. Solar drying is also employed to minimise the drying time to achieve the required moisture content. This method inherently contains complex heat and mass transfer mechanisms, which makes difficult to describe drying kinetics at the micro level. Read More

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Structural, diffuse reflectance and luminescence study of t-MgBO nanostructures.

Appl Phys A Mater Sci Process 2021 23;127(8):617. Epub 2021 Jul 23.

Department of Physics, University of Petroleum and Energy Studies, Dehradun, Uttarakhand 248007 India.

We report here the structural, reflectance, photoluminescence and thermoluminescence study of -MgBO nanostructures synthesized using optimized combustion method relatively at much lower temperature. The rietveld refinement of X-ray diffraction data confirms single-phase triclinic crystal structure of MgBO nanoparticles. The direct band gap determined using diffuse reflectance spectra (DRS) was 5. Read More

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Conductive polyethersulfone membrane facilely prepared by simultaneous phase inversion method for enhanced anti-fouling and separation under low driven-pressure.

J Environ Manage 2021 Jul 26;297:113363. Epub 2021 Jul 26.

Shenzhen Key Laboratory of Water Resource Utilization and Environmental Pollution Control, Harbin Institute of Technology, Shenzhen, Guangdong Province, 518055, China. Electronic address:

Electrically conductive membranes have been regarded as a new alternative to overcome the crucial drawbacks of membranes, including permeability-selectivity trade-off and fouling. It is still challenging to prepare conductive membranes with good mechanical strength, high conductivity and stable separation performance by reliable materials and methods. This work developed a facile method of simultaneous phase inversion to prepare electrically conductive polyethersulfone (PES) membranes with carboxylic multiwalled carbon nanotubes (MWCNT) and graphene (Gr). Read More

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Versatile Porous Poly(arylene ether)s via Pd-Catalyzed C-O Polycondensation.

J Am Chem Soc 2021 Jul 27. Epub 2021 Jul 27.

Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.

Porous organic polymers (POPs) with strong covalent linkages between various rigid aromatic structural units having different geometries and topologies are reported. With inherent porosity, predictable structure, and tunable functionality, POPs have found utility in gas separation, heterogeneous catalysis, sensing, and water treatment. Poly(arylene ether)s (PAEs) are a family of high-performance thermoplastic materials with high glass-transition temperatures, exceptional thermal stability, robust mechanical properties, and excellent chemical resistance. Read More

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La and F dual-doped multifunctional hydroxyapatite nanoparticles: Synthesis and characterization.

Microsc Res Tech 2021 Jul 27. Epub 2021 Jul 27.

Faculty of Engineering, Electric and Electronics Engineering, Karabuk University, Karabuk, Turkey.

Hydroxyapatite (HA) co-doped with La and F ions were synthesized by the precipitation method and sintered at 1,100°C for 1 hr. Samples were characterized by the standard experimental methods including the density, X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM) to investigate their microstructure, phase formation, and bonding characteristics in detail. Moreover, the materials produced were identified using the microhardness tests. Read More

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Development and assessment of a telesonography system for musculoskeletal imaging.

Eur Radiol Exp 2021 Jul 27;5(1):29. Epub 2021 Jul 27.

Department of Medical Imaging, College of Medicine, University of Saskatchewan, Royal University Hospital, 103 Hospital Drive, Saskatoon, SK, S7N 0W8, Canada.

Background: Telesonography systems have been developed to overcome barriers to accessing diagnostic ultrasound for patients in rural and remote communities. However, most previous telesonography systems have been designed for performing only abdominal and obstetrical exams. In this paper, we describe the development and assessment of a musculoskeletal (MSK) telesonography system. Read More

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Development of mortality prediction model in the elderly hospitalized AKI patients.

Sci Rep 2021 Jul 26;11(1):15157. Epub 2021 Jul 26.

Hunan Key Laboratory of Kidney Disease and Blood Purification, Department of Nephrology, The Second Xiangya Hospital of Central South University, Changsha, 410011, Hunan, China.

Acute kidney injury (AKI) correlates with increased health-care costs and poor outcomes in older adults. However, there is no good scoring system to predict mortality within 30-day, 1-year after AKI in older adults. We performed a retrospective analysis screening data of 53,944 hospitalized elderly patients (age > 65 years) from multi-centers in China. Read More

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Middle Cerebral Artery M2 Thrombectomy in the STRATIS Registry.

Stroke 2021 Jul 27:STROKEAHA120033951. Epub 2021 Jul 27.

University of Iowa, Iowa City (K.L., M.F., S.O.-G.).

Background And Purpose: The safety and benefit of mechanical thrombectomy in the treatment of acute ischemic stroke patients with M2 segment middle cerebral artery occlusions remain uncertain. Here, we compare clinical and angiographic outcomes in M2 versus M1 occlusions in the STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) Registry.

Methods: The STRATIS Registry was a prospective, multicenter, nonrandomized, observational study of acute ischemic stroke large vessel occlusion patients treated with the Solitaire stent-retriever as the first-choice therapy within 8 hours from symptoms onset. Read More

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Determination of dynamic interactions of droplets in continuous fluids using droplet probe.

J Colloid Interface Sci 2021 Jul 18;605:91-100. Epub 2021 Jul 18.

Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China. Electronic address:

Hypothesis: Interactions between droplets are of fundamental importance for understanding phenomena involving droplet collision and coalescence that determine multiphase flow behavior. The quantitative understanding of these interactions is essential for the manipulation and control of emulsions or complex fluids. The existing methods for interaction force determination are typically based on expensive mechanical probes and fine distance control. Read More

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Synergy between vitamin E and D-sorbitol in enhancing oxidation stability of highly crosslinked ultrahigh molecular weight polyethylene.

Acta Biomater 2021 Jul 23. Epub 2021 Jul 23.

College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, 610065 Chengdu, China. Electronic address:

Oxidative stability of radiation crosslinked ultrahigh molecular weight polyethylene (UHMWPE) artificial joints is significantly improved by vitamin E (VE), but there is a dilemma that VE hinders crosslinking and thus jeopardizes the wear of UHMWPE. In this effort, we proposed an efficient strategy to stabilize UHMWPE under limited antioxidant contents, where VE and D-sorbitol (DS) were used as the primary antioxidant and the secondary antioxidant respectively. For non-irradiated blends with fixed antioxidant contents, oxidative stability accessed by oxidation induction time (OIT) of VE/DS/UHMWPE blends was superior to that of VE/UHMWPE blends, while DS/UHMWPE blends showed no increase in OIT. Read More

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Efficacy and Safety of Corticosteroids in Acute Respiratory Distress Syndrome: An overview of Meta-analyses.

Int J Clin Pract 2021 Jul 26:e14645. Epub 2021 Jul 26.

Department of Pharmacy Practice, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal, India, 576104.

Background: Evidence-based recommendations on efficacy and safety of corticosteroids in acute respiratory distress syndrome (ARDS) remains a therapeutic challenge. Findings from several systematic reviews and meta-analyses are inconsistent. We aimed to assess the published meta-analyses through a systematic review approach and provide further insight into the current uncertainty. Read More

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Highly Absorbent Silk Fibroin Protein Xerogel.

ACS Biomater Sci Eng 2021 Jul 26. Epub 2021 Jul 26.

National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou 215123, People's Republic of China.

Highly absorbent polymers have a wide range of applications in biomaterials, agriculture, physiological products of daily uses, and others. Silk fibroin, as a natural biomaterial with excellent biocompatibility and tunable mechanical properties, shows good prospects in the field of biomedicine applications. However, the dried fibroin hydrogel has very low absorbency. Read More

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Blending with Poly(l-lactic acid) Improves the Printability of Poly(l-lactide--caprolactone) and Enhances the Potential Application in Cartilage Tissue Engineering.

ACS Omega 2021 Jul 8;6(28):18300-18313. Epub 2021 Jul 8.

The Key Laboratory of Biomedical Material of Tianjin, Biomedical Barriers Research Center, Chinese Academy of Medical Sciences & Peking Union Medical College Institute of Biomedical Engineering, 236 Baidi Road, NanKai District, Tianjin 300192, P.R. China.

Poly(l-lactide--caprolactone) (PLCL, 50:50) has been used in cartilage tissue engineering because of its high elasticity. However, its mechanical properties, including its rigidity and viscoelasticity, must be improved for compatibility with native cartilage. In this study, a set of PLCL/poly(l-lactic acid) (PLLA) blends was prepared by blending with different mass ratios of PLLA that range from 10 to 50%, using thermoplastic techniques. Read More

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Self-learning on COVID-19 among medical students in Bhutan: A cross-sectional study.

Heliyon 2021 Jul 11;7(7):e07533. Epub 2021 Jul 11.

Department of Internal Medicine, Armed Forces Medical College, Maharashtra University of Health Sciences, Pune, India.

Background: Bhutan lacks a medical school and all medical students are trained in Sri Lanka, Bangladesh and India. When the COVID-19 pandemic led to the closure of medical schools in these countries in March-April 2020, the medical students were repatriated to Bhutan. Upon return, they were kept in government-sponsored facility quarantine for 21 days. Read More

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The Incidence and Risk Factors for Persistent Acute Kidney Injury Following Total Cavopulmonary Connection Surgery: A Single-Center Retrospective Analysis of 465 Children.

Front Pediatr 2021 7;9:566195. Epub 2021 Jul 7.

Department of Anesthesiology, National Center of Cardiovascular Diseases, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.

Acute kidney injury (AKI) after cardiac surgery contributes to adverse outcomes. We aimed to assess the incidence and identify the predictors for persistent AKI after total cavopulmonary connection (TCPC) surgery. A retrospective study, including 465 children undergoing TCPC surgery from 2010 to 2019, was conducted. Read More

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Two Consecutive Runs of Veno-Venous Extracorporeal Membrane Oxygenation in a Peripartum Patient with COVID-19 Acute Respiratory Distress Syndrome.

Case Rep Crit Care 2021 9;2021:2032197. Epub 2021 Jul 9.

Department of Medicine (DIMED), Padua University School of Medicine, Italy.

Veno-venous extracorporeal membrane oxygenation (V-V ECMO) may be required to treat critically ill patients with COVID-19-associated severe acute respiratory distress syndrome (ARDS). We report the case of a 43-year-old peripartum patient, who underwent two sequential V-V ECMO runs. The first extracorporeal support was established for COVID-19 ARDS, as characterized by severe hypoxemia and hypercapnia (arterial partial pressure of oxygen to inspired oxygen fraction ratio 85 mmHg and arterial partial pressure of carbon dioxide 95 mmHg) and reduction of respiratory system static compliance to 25 mL/cmHO, unresponsive to mechanical ventilation and prone positioning. Read More

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Efficacy of intravascular mechanical thrombectomy combined with thrombolysis and anticoagulant therapy in the treatment of cerebral venous sinus thrombosis and its effect on neurological function and coagulation indices.

Am J Transl Res 2021 15;13(6):6921-6928. Epub 2021 Jun 15.

Department of Neurosurgery, Tianjin Huanhu Hospital Tianjin, China.

Objective: To evaluate the efficacy of Solitaire AB stent mechanical thrombectomy combined with thrombolysis and anticoagulant therapy (AT) in the treatment of cerebral venous sinus thrombosis (CVST) and its effect on neurological function and coagulation indices.

Methods: Eighty-two patients with CVST were randomly divided into two groups according to the random number table method. The control group (n=41) were treated with arteriovenous thrombolysis combined with AT, and the observation group were treated with intravascular mechanical thrombectomy plus thrombolysis combined with AT. Read More

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Importance of Viscosity Control for Recyclable Reinforced Thermoplastic Composites.

Macromolecules 2020 Aug 30;53(15):6690-6702. Epub 2020 Jul 30.

Aachen-Maastricht Institute of BioBased Materials (AMIBM), Maastricht University, P.O. Box 616, 6200MD Maastricht, The Netherlands.

Thermoplastic composites consisting of a liquid crystalline polymer (LCP) and poly(lactide) (PLA) have the potential to combine good mechanical performance with recyclability and are therefore interesting as strong and sustainable composite materials. The viscoelastic behavior of both the LCP and the PLA is of great importance for the performance of these composites, as they determine the LCP morphology in the composite and play a crucial role in preventing the loss of mechanical performance upon recycling. Though the effect of the matrix viscosity is well-documented in literature, well-controlled systems where the LCP viscosity is tailored are not reported. Read More

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A fast algebraic approach for noninvasive prediction of fractional flow reserve in coronary arteries.

Comput Methods Biomech Biomed Engin 2021 Jul 25:1-33. Epub 2021 Jul 25.

Mechanical Engineering Department, American University of Beirut, Riad El-Solh, Beirut, Lebanon.

The fractional flow reserve (FFR) index is an important clinical indicator for characterizing coronary artery disease (CAD) functional significance, allowing cardiologists to decide whether intervention is required or not. Noninvasive techniques for calculating FFR are still incompletely resolved and rely heavily on time consuming numerical methods, which may hinder their clinical translation. This paper reports on the development of two fast and noninvasive methods for predicting FFR in diseased coronary arteries. Read More

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MICROSTRUCTURAL AND MECHANICAL CHARACTERIZATION OF THE LAYERS OF HUMAN DESCENDING THORACIC AORTAS.

Acta Biomater 2021 Jul 22. Epub 2021 Jul 22.

Institute of Biomechanics, Graz University of Technology, Austria; Department of Structural Engineering, Norwegian University of Science and Technology, Trondheim, Norway.

The mechanical properties of human aortas are linked to the layered tissue and its microstructure at different length scales. Each layer has specific mechanical and structural properties. While the ground substance and the elastin play an important role in tissue stiffness at small strain, collagen fibers carry most of the load at larger strains, which corresponds to the physiological conditions of the aorta at maximum pulsatile blood pressure. Read More

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Architectural model for muscle growth during maturation.

Biomech Model Mechanobiol 2021 Jul 24. Epub 2021 Jul 24.

Department of Motion and Exercise Science, University of Stuttgart, Stuttgart, Germany.

Muscle architecture, which includes parameters like fascicle length, pennation angle, and physiological cross-sectional area, strongly influences skeletal muscles' mechanical properties. During maturation, the muscle architecture has to adapt to a growing organism. This study aimed to develop an architectural model capable of predicting the complete 3D fascicle architecture for primarily unipennate muscles of an arbitrary age, based on fascicle data for an initial age. Read More

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An Ultra-Low-Temperature Elastomer with Excellent Mechanical Performance and Solvent Resistance.

Adv Mater 2021 Jul 24:e2102096. Epub 2021 Jul 24.

Department of Chemistry, Renmin University of China, Beijing, 100872, China.

Elastomers presenting good elasticity, ductility, and chemical resistance at low temperatures can serve as superior performers for explorations in extremely cold environments. However, no commercially available elastomer to date can comprehensively fulfill those demands. Here, a perfluoropolyether (PFPE)-based network crosslinked by dynamic urethane chemistry is demonstrated, which may satisfy the demands of application in ultracold environments. Read More

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Rapidly dissolving microneedle patch of amphotericin B for intracorneal fungal infections.

Drug Deliv Transl Res 2021 Jul 23. Epub 2021 Jul 23.

School of Pharmacy, Medical Biology Centre, Queen's University Belfast, 97 Lisburn Road, Belfast, BT9 7BL, Northern Ireland, UK.

Chronic fungal infection of the cornea could lead to blindness if not treated properly. Topical amphotericin B (AMP-B) is considered the first treatment of choice for ocular fungal infection. However, factors related to its poor solubility and penetration through intact cornea lead to poor bioavailability. Read More

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Wide-field optical coherence tomography deviation map for early glaucoma detection.

Br J Ophthalmol 2021 Jul 22. Epub 2021 Jul 22.

Department of Ophthalmology, Hanyang University College of Medicine, Seoul, Republic of Korea

Background/aims: This study aimed to establish a wide-field optical coherence tomography (OCT) deviation map obtained from swept-source OCT (SS-OCT) scans. Moreover, it also aimed to compare the diagnostic ability of this wide-field deviation map with that of the peripapillary and macular deviation maps currently being used for the detection of early glaucoma (EG).

Methods: Four hundred eyes, including 200 healthy eyes and 200 eyes with EG were enrolled in this retrospective observational study. Read More

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Intramedullary Fixation of Trochanteric Fractures Can Be Safely Performed by Senior Residents Without Immediate Consultant Supervision.

J Surg Educ 2021 Jul 21. Epub 2021 Jul 21.

Kanta-Häme Central Hospital, Department of Orthopedics and Traumatology, Hämeenlinna, Finland.

Objective: To assess the safety of senior residents performing trochanteric hip fracture surgery without immediate consultant supervision DESIGN: A retrospective chart review of trochanteric hip fractures (AO-OTA 31-A) operated in a single center between years 2011 and 2016 (inclusive). Operations were divided into three groups: Group 1 - surgeon was a senior resident without any immediate supervision; Group 2 - surgeon was a consultant and Group 3 - surgeon was a senior resident supervised by a consultant. The follow-up period was a minimum of 2 years or until death. Read More

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Biomechanical effect of intertrochanteric curved varus osteotomy on stress reduction in femoral head osteonecrosis: a finite element analysis.

J Orthop Surg Res 2021 Jul 23;16(1):465. Epub 2021 Jul 23.

Department of Orthopaedic Surgery, Faculty of Medicine, University of Miyazaki, Miyazaki, Miyazaki, Japan.

Background: Intertrochanteric curved varus osteotomy (CVO) has been widely used to remove the necrotic bone away from the weight-bearing portion in the treatment of osteonecrosis of the femoral head (ONFH). However, whether all types of necrosis will benefit from CVO, in terms of the stress level, the effect of different center-edge (CE) angles of acetabulum on stress distribution of necrosis after CVO, and the relationship between the intact ratio and the stress of necrosis, has never been addressed. The purpose of the study was to evaluate the influence of CVO on the stress reduction in necrotic bone using a finite element analysis (FEA) with different CE angles. Read More

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Polyethylene/Polyamide Blends Made of Waste with Compatibilizer: Processing, Morphology, Rheological and Thermo-Mechanical Behavior.

Polymers (Basel) 2021 Jul 20;13(14). Epub 2021 Jul 20.

Department of Interdisciplinary Dentistry, Pomeranian Medical University, 70-111 Szczecin, Poland.

The aim of this study was to develop a polyethylene/polyamide (R-PE/R-PA) regranulated product made from post-consumer wastes grafted with polyethylene-graft-maleic anhydride (PE-g-MAH) by reactive extrusion in a twin-screw extruder equipped with an external mixing zone. The compatibility effect of PE-g-MAH used as a modifier in R-PE/R-PA blends was evaluated by means of differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA), while the analysis of the chemical structure of this blend was carried out by Fourier transform infrared spectroscopy (FT-IR). The thermal properties, complex viscosity, and selected usage properties of R-PE/R-PA blends compatibilized with PE-g-MAH, i. Read More

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Physicochemical, Bacteriostatic, and Biological Properties of Starch/Chitosan Polymer Composites Modified by Graphene Oxide, Designed as New Bionanomaterials.

Polymers (Basel) 2021 Jul 15;13(14). Epub 2021 Jul 15.

Faculty of Food Technology, University of Agriculture in Krakow, Balicka Street 122, 30-149 Krakow, Poland.

The application of natural polymer matrices as medical device components or food packaging materials has gained a considerable popularity in recent years, this has occurred in response to the increasing plastic pollution hazard. Currently, constant progress is being made in designing two-component or three-component systems that combine natural materials which help to achieve a quality comparable to the purely synthetic counterparts. This study describes a green synthesis preparation of new bionanocomposites consisting of starch/chitosan/graphene oxide (GO), that possess improved biological activities; namely, good tolerability by human cells with concomitant antimicrobial activity. Read More

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