91,528 results match your criteria mechanical model


Patient-specific tumor and respiratory monitoring phantom design for quality controls of stereotactic ablative body radiotherapy in lung cancer cases.

Phys Med 2021 Sep 14;90:40-49. Epub 2021 Sep 14.

Department of Radiation Oncology, Cancer Institute, Hacettepe University Faculty of Medicine, 06100 Ankara, Turkey.

The design, production and adaptability to clinical routine of a patient-specific tumor and respiratory monitoring phantom (TRMP) was investigated using 3D printer technology. TRMP and GTV modelling were done using 4D-CT images of the inhalation phase. The model was converted to STL (Stereolithography) format and printed with STH (Strong Herbal) biopolymer with HU (Hounsfield Unit) suitable for imaging purposes. Read More

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September 2021

Unfolding the interaction between microplastics and (trace) elements in water: A critical review.

Water Res 2021 Sep 8;204:117637. Epub 2021 Sep 8.

Norwegian Institute for Water Research (NIVA), Gaustadalléen 21, 0349 Oslo, Norway; RECETOX, Masarik University, Kamenice 753/5, 625 00 Brno, Czech Republic. Electronic address:

Plastic and microplastic pollution is an environmental and societal concern. The interaction of plastic with organic chemicals in the environment has attracted scientific interest. New evidences have highlighted an unexpectedly high affinity of environmental plastics also for metal ions. Read More

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September 2021

Effect of pectin and attapulgite filler on swelling, network parameters and controlled release of diltiazem hydrochloride from polyacrylic copolymer gel.

Int J Biol Macromol 2021 Sep 15. Epub 2021 Sep 15.

Department of Polymer Science and Technology, University of Calcutta 92, A.P.C. Road, Kolkata 700009, India. Electronic address:

Pectin grafted polyacrylic copolymer hydrogels were made by free radical crosslink copolymerization of acrylic acid (AA) and acrylamide (AM) in an aqueous solution of pectin. N'N-methylene bis acrylamide (MBA) was used as a crosslinker. During the polymerization reaction the attapulgite (APG) filler was also incorporated in situ into the network of the copolymer gel. Read More

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September 2021

Modelling and Analysis of Nature-inspired Branched Micropillars for Enhanced Dynamic Bio-Sensing.

Int J Numer Method Biomed Eng 2021 Sep 18. Epub 2021 Sep 18.

Department of Mechanical, Materials and Manufacturing Engineering, University of Nottingham (Malaysia Campus), Semenyih, Malaysia.

Research evidence abounds on the effectiveness of micropillar-based microelectromechanical systems for the detection of a wide variety of ultrasmall biological objects for clinical and non-clinical. applications. However, the standard micropillar-based sensing platforms rely on a single-column micropillar with a spot at the tip for binding of objects. Read More

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September 2021

Predictive values of left ventricular mechanical dyssynchrony for CRT response in heart failure patients with different pathophysiology.

J Nucl Cardiol 2021 Sep 17. Epub 2021 Sep 17.

Department of Applied Computing, Michigan Technological University, 1400 Townsend Dr, Houghton, MI, 49931, USA.

Background: Cardiac resynchronization therapy (CRT) patients with different pathophysiology may influence mechanical dyssynchrony and get different ventricular resynchronization and clinical outcomes.

Methods: Ninety-two dilated cardiomyopathy (DCM) and fifty ischemic cardiomyopathy (ICM) patients with gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) were included in this retrospective study. Patients were classified based on the concordance between the left ventricular (LV) lead and the latest contraction or relaxation position. Read More

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September 2021

Evaluation of green lean production in textile industry: a hybrid fuzzy decision-making framework.

Environ Sci Pollut Res Int 2021 Sep 18. Epub 2021 Sep 18.

Department of Industrial Engineering, Faculty of Industrial and Mechanical Engineering, Islamic Azad University, Qazvin Branch, Qazvin, Iran.

Textile industry is an old and effective industry in Iran. However, due to its age and high energy consumption, this industry has low profitability and entrepreneurship. One of the most important problems of the weaving industry is the issue of waste regarding manpower, materials, machinery, and especially energy consumption. Read More

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September 2021

Erythrocyte flow through the interendothelial slits of the splenic venous sinus.

Biomech Model Mechanobiol 2021 Sep 18. Epub 2021 Sep 18.

Department of Structural Engineering, University of California, San Diego, La Jolla, CA, 92093, USA.

The flow patterns of red blood cells through the spleen are intimately linked to clearance of senescent RBCs, with clearance principally occurring within the open flow through the red pulp and slits of the venous sinus system that exists in humans, rats, and dogs. Passage through interendothelial slits (IESs) of the sinus has been shown by MacDonald et al. (Microvasc Res 33:118-134, 1987) to be mediated by the caliber, i. Read More

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September 2021

Machine learning assisted design of new lattice core for sandwich structures with superior load carrying capacity.

Sci Rep 2021 Sep 17;11(1):18552. Epub 2021 Sep 17.

Department of Mechanical and Industrial Engineering, Louisiana State University, Baton Rouge, LA, 70803, USA.

Herein new lattice unit cells with buckling load 261-308% higher than the classical octet unit cell were reported. Lattice structures have been widely used in sandwich structures as lightweight core. While stretching dominated and bending dominated cells such as octahedron, tetrahedron and octet have been designed for lightweight structures, it is plausible that other cells exist which might perform better than the existing counterparts. Read More

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September 2021

Effectiveness and safety of ivermectin in the treatment of COVID-19: protocol for a systematic review and meta-analysis.

BMJ Open 2021 Sep 17;11(9):e050532. Epub 2021 Sep 17.

Graduate Program in Sciences Applied to Women's Health, Maternidade Escola Januário Cicco (MEJC/EBSERH), Federal University of Rio Grande do Norte Health Sciences Center, Natal, Brazil.

Introduction: Ivermectin is a drug with antiviral properties and has been proposed as an alternative treatment for patients with COVID-19, in some countries; however, there is limited evidence to support its clinical use. Accordingly, the aim of this review and meta-analysis is to obtain superior evidence on the effectiveness and safety of ivermectin in treatment of COVID-19.

Methods And Analysis: We will search in the medical databases and International Clinical Trials Registry Platform databases for randomised clinical trials and quasi-randomised trials published from December 2019. Read More

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September 2021

Air flow rate and pressure control approach for the air supply subsystems in PEMFCs.

ISA Trans 2021 Sep 4. Epub 2021 Sep 4.

Department of Control Science and Engineering, Jilin University, Changchun 130022, China; Department of Control Science and Engineering, Tongji University, Shanghai 200092, China.

Simultaneous control of the air flow rate and the cathode pressure plays an essential role in enhancing the performance and prolonging the service life of a polymer electrolyte membrane fuel cell (PEMFC). However, this is challenging to implement in practice due to the high complexity and coupled dynamics of the air supply subsystem in the PEMFC. This work, based on a simplified control-oriented model, puts forward a disturbance-observer-based multi-output feedback control strategy to address the issue of synergistically controlling the air flow rate and cathode pressure. Read More

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September 2021

Recent advances in topological elastic metamaterials.

J Phys Condens Matter 2021 Sep 17. Epub 2021 Sep 17.

Hunan University, Hunan University, Changsha, Hunan, 410082, CHINA.

Topological elastic metamaterials have emerged as a new frontier in the quest of topological phases in condensed matter physics. Their exotic topological properties open a wealth of promising engineering-oriented applications that are difficult to realize with traditional elastic metamaterials, such as robust and defect insensitive waveguiding, signal sensing, and splitting. In this review, we retrospectively examine the underlying physical concept of topologically ordered states of elastic waves, starting from the one-dimensional (1D) example based on the Su-Schrieffer-Heeger (SSH) model. Read More

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September 2021

The level of urbanization influences acute ischemic stroke care: A nationwide ecological study from Germany.

J Neurol Sci 2021 Sep 13;430:119983. Epub 2021 Sep 13.

Department of Neurology, St. Josef-Hospital Bochum, Ruhr University Bochum, Germany; Medical Faculty, Ruhr University Bochum, Germany. Electronic address:

Background And Purpose: Regional differences in acute ischemic stroke (AIS) care are still reported for Germany but not fully understood. We aimed to analyze the impact of the level of urbanization on the application of proved treatment procedures and the incidence of hospitalized AIS cases in Germany.

Methods: The level of urbanization of the 401 districts and district-free cities in Germany was defined according to the Federal Institute for Building, Urban Affairs and Spatial Research classification. Read More

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September 2021

Experimental and computational analysis of a pharmaceutical-grade shape memory polymer applied to the development of gastroretentive drug delivery systems.

J Mech Behav Biomed Mater 2021 Sep 8;124:104814. Epub 2021 Sep 8.

Department of Mechanical and Industrial Engineering, University of Brescia, Via Branze 38, 25133, Brescia, Italy; Italian Interuniversity Consortium on Materials Science and Technology (INSTM), Research Unit of Brescia, Via Branze 38, 25133, Brescia, Italy. Electronic address:

The present paper aims at developing an integrated experimental/computational approach towards the design of shape memory devices fabricated by hot-processing with potential for use as gastroretentive drug delivery systems (DDSs) and for personalized therapy if 4D printing is involved. The approach was tested on a plasticized poly(vinyl alcohol) (PVA) of pharmaceutical grade, with a glass transition temperature close to that of the human body (i.e. Read More

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September 2021

A machine learning model for early detection of diabetic foot using thermogram images.

Comput Biol Med 2021 Sep 9;137:104838. Epub 2021 Sep 9.

Weill Cornell Medicine-Qatar, Ar-Rayyan, Qatar.

Diabetes foot ulceration (DFU) and amputation are a cause of significant morbidity. The prevention of DFU may be achieved by the identification of patients at risk of DFU and the institution of preventative measures through education and offloading. Several studies have reported that thermogram images may help to detect an increase in plantar temperature prior to DFU. Read More

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September 2021

Static Cyclic Fatigue Resistance in Acute Curvature, Surface Topography and Torsional Strength of R-Pilot and Proglider Glide Path Instruments.

J Endod 2021 Sep 14. Epub 2021 Sep 14.

Department of Endodontics, Ondokuz Mayis University Faculty of Dentistry, Samsun, Turkey.

Introduction: This study aimed to compare ProGlider (Dentsply Sirona, Ballaigues, Switzerland) and R-Pilot (VDW, Munich, Germany) instruments in terms of their cyclic fatigue resistance using an artificial stainless-steel canal showing abrupt apical curvature, torsional resistance according to the ISO specification, and topographic changes on instrument surface following glide path management in mesial canals of mandibular first molars with abrupt curvature selected based on their micro-computed tomography (micro-CT) examination.

Methods: Eighty instruments were used: 40 ProGlider (size 0.16, . Read More

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September 2021

Macro and micro analysis on coal-bearing soil slopes instability based on CFD-DEM coupling method.

PLoS One 2021 17;16(9):e0257362. Epub 2021 Sep 17.

School of Civil and Architectural Engineering, Nanchang Institute of Technology, Nanchang, China.

By combining the discrete element method (DEM) with computational fluid dynamics (CFD), this study proposes a three-dimensional CFD-DEM fluid-solid coupling microscopic computational model for analyzing the micromechanisms of instability and failure in a coal-bearing soil slope during rainfall. The CFD-DEM fluid-solid coupling model indicated that the main failure mode of the coal-bearing soil slopes was rainwater washing, and the slope sliding surface was predicted as an approximately linear segment. The adaptability of this numerical method was verified by comparing its results with those of rain-washed slopes in an outdoor model test. Read More

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September 2021

Design and Characterization of an Ultrasound Transducer for Combined Histotripsy-Thrombolytic Therapy.

IEEE Trans Ultrason Ferroelectr Freq Control 2021 Sep 17;PP. Epub 2021 Sep 17.

Chronic thrombi of the deep veins of the leg are resistant to dissolution or removal by current interventions and can act as thrombogenic sources. Histotripsy, a focused ultrasound therapy, uses the mechanical activity of bubble clouds to liquefy target tissues. In vitro experiments have shown that histotripsy enhances thrombolytic agent recombinant tissue plasminogen activator in a highly retracted clot model resistant to lytic therapy alone. Read More

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September 2021

The Effects of Proximal Fibular Osteotomy on the Knee and Ankle Joints: a Finite Element Analysis.

Acta Chir Orthop Traumatol Cech 2021 ;88(4):313-320

Department of Orthopedics and Traumatology, Maltepe University Faculty of Medicine, Istanbul, Turkey.

PURPOSE OF THE STUDY In this study, our aim is to examine the effect of proximal fibular osteotomy on knee and ankle kinematics with finite element analysis method. MATERIAL AND METHODS One 62-year-old, female volunteer's radiologic images were used for creating lower limb model. Osteotomized model (OM) which was created according to definition of PFO and non-osteotomized model (NOM) were created. Read More

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January 2021

Modeling Liquid Water by Climbing up Jacob's Ladder in Density Functional Theory Facilitated by Using Deep Neural Network Potentials.

J Phys Chem B 2021 Sep 17. Epub 2021 Sep 17.

Department of Physics, Temple University, Philadelphia, Pennsylvania 19122, United States.

Within the framework of Kohn-Sham density functional theory (DFT), the ability to provide good predictions of water properties by employing a strongly constrained and appropriately normed (SCAN) functional has been extensively demonstrated in recent years. Here, we further advance the modeling of water by building a more accurate model on the fourth rung of Jacob's ladder with the hybrid functional, SCAN0. In particular, we carry out both classical and Feynman path-integral molecular dynamics calculations of water with the SCAN0 functional and the isobaric-isothermal ensemble. Read More

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September 2021

Shear strain and inflammation-induced fixed charge density loss in the knee joint cartilage following ACL injury and reconstruction: a computational study.

J Orthop Res 2021 Sep 17. Epub 2021 Sep 17.

Department of Applied Physics, University of Eastern Finland, Kuopio, Finland, Yliopistonranta 1, FI, 70210, Kuopio, Finland.

Excessive tissue deformation near cartilage lesions and acute inflammation within the knee joint after anterior cruciate ligament (ACL) rupture and reconstruction surgery accelerate the loss of fixed charge density (FCD) and subsequent cartilage tissue degeneration. Here, we show how biomechanical and biochemical degradation pathways can predict FCD loss using a patient-specific finite element model of an ACL reconstructed knee joint exhibiting a chondral lesion. Biomechanical degradation was based on the excessive maximum shear strains that may result in cell apoptosis, while biochemical degradation was driven by the diffusion of pro-inflammatory cytokines. Read More

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September 2021

Constraints on the Initial State of Pb-Pb Collisions via Measurements of Z-Boson Yields and Azimuthal Anisotropy at sqrt[s_{NN}]=5.02  TeV.

Phys Rev Lett 2021 Sep;127(10):102002

Universiteit Antwerpen, Antwerpen, Belgium.

The CMS experiment at the LHC has measured the differential cross sections of Z bosons decaying to pairs of leptons, as functions of transverse momentum and rapidity, in lead-lead collisions at a nucleon-nucleon center-of-mass energy of 5.02  TeV. The measured Z boson elliptic azimuthal anisotropy coefficient is compatible with zero, showing that Z bosons do not experience significant final-state interactions in the medium produced in the collision. Read More

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September 2021

Experimentally Inferred Fusion Yield Dependencies of OMEGA Inertial Confinement Fusion Implosions.

Phys Rev Lett 2021 Sep;127(10):105001

Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA.

Statistical modeling of experimental and simulation databases has enabled the development of an accurate predictive capability for deuterium-tritium layered cryogenic implosions at the OMEGA laser [V. Gopalaswamy et al.,Nature 565, 581 (2019)10. Read More

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September 2021

Crystal capillary origami capsule with self-assembled nanostructures.

Nanoscale 2021 Sep 17;13(35):14656-14665. Epub 2021 Sep 17.

Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea.

The self-assembling mechanism of elasto-capillaries opens new applications in micro and nanotechnology by providing 3D assembly structures with 2D planar unit cells, so-called capillary origami. To date, the final structure has been designed based on the predetermined shape and size of the unit cell. Here, we show that plate-like salt crystallites grow and cover the emulsion interface, which is driven by Laplace pressure. Read More

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September 2021

Optimal Lymph Node Staging System in Evaluating Prognosis of Gallbladder Carcinoma: A Multi-institutional Study.

Ann Surg Oncol 2021 Sep 16. Epub 2021 Sep 16.

Department of Hepatobiliary Surgery, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.

Background: Lymph node (LN) involvement is a critical prognostic factor in patients with gallbladder carcinoma (GBC). Controversy exists regarding optimal categorization of nodal metastasis status, including anatomical location of positive nodes (AJCC 7th N staging), number of metastatic lymph nodes (NMLN), log odds of metastatic LNs (LODDS), and lymph node ratio (LNR).

Methods: Patients who underwent curative-intent resection for GBC from six Chinese tertiary hospitals between 2008 and 2013 were analyzed retrospectively. Read More

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September 2021

Saving critically ill COVID-19 patients with mechanical circulatory support.

Ann Transl Med 2021 Aug;9(15):1221

Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.

Background: Coronavirus disease 2019 (COVID-19) is an ongoing public health crisis that has led to many deaths due to multiple organ dysfunction syndromes (MODS). This article describes the clinical characteristics, management, and outcomes of critically ill COVID-19 patients who survived the disease through mechanical circulatory support (MCS).

Methods: We studied 25 critically ill COVID-19 patients who underwent MCS from January 20, 2020, to April 10, 2020, at the Tongji Hospital of Huazhong University of Science and Technology. Read More

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Development of a Three-Dimensionally Printed Ultrasound-Guided Peripheral Intravenous Catheter Phantom.

Cureus 2021 Aug 13;13(8):e17139. Epub 2021 Aug 13.

Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, USA.

Introduction Ultrasound-guided peripheral intravenous catheter (US-PIVC) placement is an effective technique to establish PIV access when the traditional approach fails. Many training programs utilize commercial or homemade phantoms for procedural training. However, commercial products tend to be expensive and lack realism, while homemade blocks tend to be single-use and degrade easily. Read More

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Dynamical behavior of coal shearer under the influence of multiple factors in slant-cutting conditions.

Sci Rep 2021 Sep 16;11(1):18447. Epub 2021 Sep 16.

School of Mechanical Engineering, Liaoning Technical University, Fuxin, 123000, Liaoning, China.

Aiming at the problem of severe vibration and abnormal wear and tear of various components in coal shearer under slant-cutting conditions, a non-linear dynamics model with 13 degrees of freedom for a coal shearer under slant-cutting conditions is developed using vibration mechanics and multi-body dynamics theory, and the characteristics of the slide shoes-middle groove contact, the ranging arm-haulage unit connection with gaps and the guidance sliding boots-pin rail multi-surface contact with gaps are described based on three-dimensional fractal theory and Hertz contact theory. Based on Huco's law, the ranging arm and the hydraulic rod are assumed to be flexible beams, the rigidity characteristics of the ranging arm itself, the connection characteristics of the haulage unit and the fuselage are described, a drum correction load with a traction speed correction factor is proposed as the external excitation of the system, and the model is solved and analyzed. The research results show that the change of traction speed has a greater influence on the vibration swing angle and displacement of the front drum, front ranging arm and front walking unit, and the vibration swing angle and displacement of the three increase with the increase of traction speed, while the change of coalface hardness coefficient has less influence on the vibration displacement of the key components of the coal shearer. Read More

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September 2021

Evidence for biosurfactant-induced flow in corners and bacterial spreading in unsaturated porous media.

Proc Natl Acad Sci U S A 2021 Sep;118(38)

Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544;

The spread of pathogenic bacteria in unsaturated porous media, where air and liquid coexist in pore spaces, is the major cause of soil contamination by pathogens, soft rot in plants, food spoilage, and many pulmonary diseases. However, visualization and fundamental understanding of bacterial transport in unsaturated porous media are currently lacking, limiting the ability to address the above contamination- and disease-related issues. Here, we demonstrate a previously unreported mechanism by which bacterial cells are transported in unsaturated porous media. Read More

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September 2021

Neuroprotective effect of -theanine in a rat model of chronic constriction injury of sciatic nerve-induced neuropathic pain.

J Formos Med Assoc 2021 Sep 13. Epub 2021 Sep 13.

Department of Neurosurgery, Mackay Memorial Hospital, Taipei, 10449, Taiwan, ROC; Department of Medicine, Mackay Medical College, New Taipei City, 252, Taiwan, ROC. Electronic address:

Background/purpose: We investigated the protective efficacy of -theanine (LT), the major amino acid components of green tea, on chronic constriction injury (CCI) of sciatic nerve-induced neuropathic pain (NP) development and neuronal functional changes in rats.

Methods: Rats with NP induced by CCI of the left sciatic nerve and sham-operated rats received LT or saline solution, with pain sensitive tests of thermal hyperalgesia and mechanical allodynia. Motor and sensory nerve conduction velocities were measured after surgery. Read More

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September 2021

Previous herbivory modulates aphid population growth and plant defense responses in a non-model plant, (Asteraceae).

Bull Entomol Res 2021 Sep 17:1-11. Epub 2021 Sep 17.

Department of Biodiversity, Institute of Science and High Technology and Environmental Sciences, Graduate University of Advanced Technology, Kerman, Iran.

Plants have a variety of defense mechanisms that are often induced following attacks by herbivores; this benefits those plants by decreasing performance or preference of herbivores that attack the plants later. We investigated the effects of previous exposure of plants to the safflower aphid, Uroleucon carthami, cotton bollworm, Helicoverpa armigera, and mechanical wounding on subsequent safflower aphid infestations using commercial safflower (Carthamus tinctorius) cultivars and wild safflower species (C. oxyacantha). Read More

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September 2021