scholarly journals Magnetic field-mediated Janus particles with sustained driving capability for severe bleeding control in perforating and inflected wounds

2021 ◽  
Vol 6 (12) ◽  
pp. 4625-4639
Author(s):  
Qing Li ◽  
Enling Hu ◽  
Kun Yu ◽  
Mengxing Lu ◽  
Ruiqi Xie ◽  
...  
RSC Advances ◽  
2021 ◽  
Vol 11 (28) ◽  
pp. 17051-17057
Author(s):  
Anna Eichler-Volf ◽  
Yara Alsaadawi ◽  
Fernando Vazquez Luna ◽  
Qaiser Ali Khan ◽  
Simon Stierle ◽  
...  

PS/CoPd Janus particles respond very sensitively to application of low external magnetic fields. Owing to the magnetic properties, the PS/CoPd particles may be used, for example, to sense the presence of weak magnetic fields as micro-magnetometers.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rico Huhnstock ◽  
Meike Reginka ◽  
Andreea Tomita ◽  
Maximilian Merkel ◽  
Kristina Dingel ◽  
...  

AbstractMagnetic Janus particles (MJPs), fabricated by covering a non-magnetic spherical particle with a hemispherical magnetic in-plane exchange-bias layer system cap, display an onion magnetization state for comparably large diameters of a few microns. In this work, the motion characteristics of these MJPs will be investigated when they are steered by a magnetic field landscape over prototypical parallel-stripe domains, dynamically varied by superposed external magnetic field pulse sequences, in an aqueous medium. We demonstrate, that due to the engineered magnetization state in the hemispherical cap, a comparably fast, directed particle transport and particle rotation can be induced. Additionally, by modifying the frequency of the applied pulse sequence and the strengths of the individual field components, we observe a possible separation between a combined or an individual occurrence of these two types of motion. Our findings bear importance for lab-on-a-chip systems, where particle immobilization on a surface via analyte bridges shall be used for low concentration analyte detection and a particle rotation over a defined position of a substrate may dramatically increase the immobilization (and therefore analyte detection) probability.


2017 ◽  
Vol 53 (67) ◽  
pp. 9296-9299 ◽  
Author(s):  
Sven Sagebiel ◽  
Lucas Stricker ◽  
Sabrina Engel ◽  
Bart Jan Ravoo

Janus particles with polymer caps self-assemble into dual responsive particle chains that can be manipulated with light and a magnetic field.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christof K. Audretsch ◽  
◽  
Daniel Mader ◽  
Christian Bahrs ◽  
Alexander Trulson ◽  
...  

AbstractSevere bleeding is the major cause of death in unstable pelvic ring fractures. Therefore, a quick and efficient emergency stabilization and bleeding control is inevitable. C-clamp and pelvic binder are efficient tools for temporary bleeding control, especially from the posterior pelvic ring. Yet the C-clamp requires more user knowledge, training and equipment. However, whether this makes up for a more efficient bleeding control, is still under debate. Patients with a type-C pelvic ring fracture were identified from the German Pelvic Registry (GPR) and divided into three groups of 40 patients (1. no emergency stabilization, 2. pelvic binder, 3. C-clamp). The matching occurred according to the parameters age, gender, initial RR and initial HB. Complication—and mortality rates were compared especially regarding bleeding control. Regarding ISS and fracture dislocation there was no difference. The use of the C-clamp resulted in more complications, a higher mortality rate due to severe bleeding and more blood transfusions were admitted. Moreover the pelvic binder was established noticeably faster. However, the C-clamp was more often rated as effective. There is no evidence of advantage comparing the C-clamp to the pelvic binder, regarding bleeding control in type-C pelvic ring fractures. In fact, using the pelvic binder even showed better results, as the time until established bleeding control was significantly shorter. Therefore, the pelvic binder should be the first choice. The C-clamp should remain a measure for selected cases only, if an adequate bleeding control cannot be achieved by the pelvic binder.


2018 ◽  
Vol 54 (21) ◽  
pp. 2607-2610 ◽  
Author(s):  
Midori Teshima ◽  
Takahiro Seki ◽  
Yukikazu Takeoka

We established a simple method for preparing Janus particles displaying different structural colors using submicron-sized fine silica particles and magnetic nanoparticles composed of Fe3O4.


2008 ◽  
Vol 1135 ◽  
Author(s):  
Amro K. F. Dyab ◽  
Vesselin N. Paunov

ABSTRACTWe have designed a novel technique for fabrication of magnetic Janus microparticles based on “trapping” the alignment of magnetite nanoparticles dispersed within the oil drops of polymerizable oil-in-water emulsion. We polymerized the oil drops after gelling the continuous aqueous phase in the presence of an external magnetic filed. This allowed us to produce magnetic Janus particles with optical and magnetic anisotropy which form unusual zigzag chains and structures when an external magnetic field is applied to a suspension of such particles. These novel microparticles retain high remanence magnetization and coercivity values indicative of ferromagnetic behavior, which indicates that the composite polymeric Janus microparticles posses a net magnetic dipole and behave like micro-magnets due to the “trapped” orientation of the magnetite nanoparticles in their polymeric matrix.


2017 ◽  
Vol 32 (2) ◽  
pp. 47-48 ◽  
Author(s):  
Marcus J. P. Geist ◽  
Jens Kessler ◽  
Susanne Frankenhauser ◽  
Hubert J. Bardenheuer

Background: Persistent bleeding is a common reason for admitting patients with advanced cancer to a palliative care unit. Several reports show a successful therapeutic use of the antifibrinolytic agent tranexamic acid in palliative care patients having hemorrhages. However, it is not administered routinely in severe bleeding situations in palliative care, and general dosing recommendations are unclear. Case Presentation: We report on 3 patients who were treated with tranexamic acid due to symptomatic hemorrhage complicating different malignant processes. Case Management and Outcome: A dosing regimen of 1000 mg intravenous tranexamic acid 3 times a day caused an arrest of bleeding in the reported patients within 2 to 3 days. Having controlled the acute bleeding, we continued with an oral administration of 3000 mg per day as maintenance dose. Conclusions: The described dosing regimen was effective in controlling the symptomatic bleeding of the reported patients. Further studies are needed to get evidence-based information on the optimal dosing regimen of tranexamic acid and to emphasize its significance in palliative medicine.


2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Shin Na ◽  
Ji Yong Ahn ◽  
Kee Wook Jung ◽  
Jeong Hoon Lee ◽  
Do Hoon Kim ◽  
...  

Background and Aim. In some cases of iatrogenic Mallory-Weiss tears (MWTs), hemostasis is needed due to severe mucosal tearing with bleeding. Therefore, we aimed to evaluate the risk factors for severe iatrogenic MWTs and the methods of endoscopic bleeding control. Materials and Methods. Between January 2008 and December 2012, 426,085 cases of screening upper endoscopy were performed at the Asan Medical Center. We retrospectively analyzed the risk factors for severe iatrogenic MWTs requiring an endoscopic procedure and the treatment modalities of bleeding control. Results. Iatrogenic MWTs occurred in 546 cases (0.13%) of screening upper endoscopy in 539 patients. Bleeding control due to severe bleeding was applied in 71 cases (13.0%), and rebleeding after initial bleeding control occurred in 1 case. Multivariate analysis showed that old age, a history of distal gastrectomy, and a less-experienced endoscopist (fewer than 2,237.5 endoscopic procedures at the time of the MWT) were associated with severe iatrogenic MWTs requiring an endoscopic procedure. Among 71 cases requiring bleeding control, a hemoclip was used in 81.7% (58 cases). Conclusions. Screening endoscopy procedures should be carefully performed when patients are in their old age and have a history of distal gastrectomy, particularly if the endoscopist is less experienced.


Soft Matter ◽  
2015 ◽  
Vol 11 (18) ◽  
pp. 3581-3588 ◽  
Author(s):  
Qingguang Xie ◽  
Gary B. Davies ◽  
Florian Günther ◽  
Jens Harting

We present theory and simulations describing the behaviour of magnetic Janus particles adsorbed at fluid–fluid interfaces interacting with an external magnetic field. We show that the particles deform the interface in a dipolar manner and suggest how to utilise capillary interactions to create novel, reconfigurable materials.


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