Initial study on removing cellular residues from hydrostatic high-pressure treated allogeneic tissue using ultrasound

AbstractHydrostatic high-pressure technology (HHD) devitalizes tissue quickly and gently, without negatively affecting the structural properties. HHD-treated tissues must be cleaned from devitalized cells. A partially automated, gentle, reproducible and timesaving rinsing test setup utilizing ultrasound is demonstrated in this study. The test setup is used to clean HHD-treated bone allografts of tissue residues and prevent microbiological contamination. A rinsing procedure is investigated. Residual DNA content determination is utilized to analyze cleaned bone allograft tissue for rinsing procedure evaluation.

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High-pressure structural phase transition and metallization in Ga2S3 under non-hydrostatic and hydrostatic conditions up to 36.4 GPa

Journal of Materials Chemistry C ◽

10.1039/d0tc06004f ◽

2021 ◽

Author(s):

Linfei Yang ◽

Jianjun Jiang ◽

Lidong Dai ◽

Haiying Hu ◽

Meiling Hong ◽

...

Keyword(s):

Phase Transition ◽

Raman Spectroscopy ◽

High Pressure ◽

Structural Properties ◽

Structural Phase Transition ◽

First Principles ◽

Theoretical Calculations ◽

Structural Phase

The vibrational, electrical and structural properties of Ga2S3 were explored by Raman spectroscopy, EC measurements, HRTEM and First-principles theoretical calculations under different pressure environments up to 36.4 GPa.

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Structural Properties of Anthracene Under High Pressure

High Pressure Research ◽

10.1080/08957950212776 ◽

2002 ◽

Vol 22 (2) ◽

pp. 343-347 ◽

Cited By ~ 9

Author(s):

M. Oehzelt ◽

K. Weinmeier ◽

G. Heimel ◽

P. Puschnig ◽

R. Resel ◽

...

Keyword(s):

High Pressure ◽

Structural Properties

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Collagen-Platelet Composites Improve the Biomechanical Properties of Healing Anterior Cruciate Ligament Grafts in a Porcine Model

The American Journal of Sports Medicine ◽

10.1177/0363546509332257 ◽

2009 ◽

Vol 37 (8) ◽

pp. 1554-1563 ◽

Cited By ~ 94

Author(s):

Braden C. Fleming ◽

Kurt P. Spindler ◽

Matthew P. Palmer ◽

Elise M. Magarian ◽

Martha M. Murray

Keyword(s):

Anterior Cruciate Ligament ◽

Structural Properties ◽

Acl Reconstruction ◽

Porcine Model ◽

Cruciate Ligament ◽

Bone Allograft ◽

Knee Laxity ◽

Biomechanical Properties ◽

Anterior Cruciate ◽

Vessel Infiltration

Background The outcome of anterior cruciate ligament (ACL) reconstruction is variable, and many patients have increased joint laxity postoperatively. Hypothesis Placement of a collagen-platelet composite (CPC) around the graft at the time of ACL reconstruction decreases postoperative knee laxity and improves the structural properties of the graft compared with standard ACL reconstruction. Study Design Controlled laboratory study. Methods Thirteen immature pigs underwent unilateral ACL reconstruction with a bone–patellar tendon–bone allograft. In 6 pigs, a standard allograft was used to reconstruct the ACL. In 7 pigs, a CPC was placed around the allograft. After 15 weeks of healing, the animals were euthanized, and the anterior-posterior (AP) knee laxity and structural properties of the graft were measured. Qualitative histology of the grafts was also performed. Results The AP laxity values of the reconstructed knees, normalized to the contralateral control, were significantly reduced by 28% and 57% at 60° and 90° of knee flexion, respectively, with the addition of CPC (P <. 001). Significant improvements in the graft structural properties were also found; the normalized yield (P =. 044) and maximum failure loads (P =. 025) of the CPC group were 60% higher than the standard ACL-reconstructed group. Although cellular and vessel infiltration were observed in the grafts of both groups, regions of necrosis were present only in the standard ACL-reconstructed group. Conclusion These data demonstrate that the application of CPC at the time of ACL reconstruction improves the structural properties of the graft and reduces early AP knee laxity in the porcine model after 15 weeks of healing. Clinical Relevance Application of a CPC to an ACL graft at the time of surgery decreased knee laxity and increased the structural properties of the graft after 15 weeks of healing.

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Effects of gamma radiation and post-operative cisplatin injection on the incorporation of bone allografts in rats

Український радіологічний та онкологічний журнал ◽

10.46879/ukroj.3.2021.51-62 ◽

2021 ◽

Vol 29 (3) ◽

pp. 51-62

Author(s):

O.Ye. Vyrva ◽

Ya.O. Holovina ◽

N.O. Ashukina ◽

R.V. Malyk ◽

Z.M. Danyshchuk

Keyword(s):

Gamma Radiation ◽

Bone Tissue ◽

Intraperitoneal Injection ◽

Fibrous Tissue ◽

Bone Allograft ◽

Relative Area ◽

Control Groups ◽

Distal Metaphysis ◽

Bone Allografts ◽

Oncological Patients

Background. The reconstruction of long bone defects that occur after resection of tumors is a problem that requires constant study. Bone allografts are often used in this scenario. Unfortunately, while they are prepared, allografts partially lose their strength and osteoinductive properties; their survivability in oncological patients is only 40% after 10 years. This is why the search for superior allograft treatment methods and the study of allograft remodeling and incorporation in oncological patients, whose state has been affected by radiation or chemotherapy, is an area of interest. Purpose – study the structure of bone tissue in the distal metaphysis of a rat’s femur after bone allograft implantation (sterilized using gamma radiation or antibiotic saturation) and post-operative intraperitoneal cisplatin injection. Materials and Methods. Experiments were performed on 20 male white rats aged 5–6 months at the beginning of the experiment and weighed 365.8 ± 6.4g. All rats underwent a surgery that created a defect in the distal metaphysis of the femur which was filled with a bone allograft treated with gamma radiation (Control-1 and Experimental-1 groups) or saturated with an antibiotic (Control-2 and Experimental-2 groups). 14 days after allograft implantation, animals from the control groups received an intraperitoneal injection of 2.0–2.4 ml of 0.9% NaCl, while animals from the experimental groups received 2.5mg/kg of cisplatin. Histological analysis and histomorphometry were completed 30 days after the surgery. Results. 30 days after the operation, the smallest relative area of bone tissue (11.79%) was observed in rats from the Experimental-1 group, with gamma radiation treated allografts and post-operative intraperitoneal cisplatin injections. A somewhat higher value was found in the Experimental-2 group (antibiotic saturation + cisplatin) – 31.64%. In the control groups, (intraperitoneal injection 0.9% NaCl), the relative area of bone tissue was 16.7% (Control-1, gamma radiation treatment) and 58.09% (Control-2, antibiotic saturation). The relative area of fibrous tissue was the largest in the Experimental-1 group – 31.55% and the smallest in the Control-2 group – 12.79%. Conclusions. Allograft remodeling occurs along with the formation of bone and fibrous tissue when allografts are used to fill defects in the distal femoral metaphysis of rats, However, the relative percentages of those tissues depend on the allograft sterilization method and the use of cytostatic agents. The largest relative percentage of bone tissue (58.09%) was obtained using an allograft saturated with antibiotics and without the administration of cisplatin. The smallest (11.79%), on the other hand, occurred in gamma radiation treated allografts with cisplatin injected intraperitoneally after the operation

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Influence of Backward- and Forward-Facing Steps on the Flow Through a Turning Mid Turbine Frame

Journal of Turbomachinery ◽

10.1115/1.4037859 ◽

2017 ◽

Vol 139 (12) ◽

Author(s):

Sabine Bauinger ◽

Emil Goettlich ◽

Franz Heitmeir ◽

Franz Malzacher

Keyword(s):

High Pressure ◽

Total Pressure ◽

Test Rig ◽

Test Setup ◽

Aero Engine ◽

Total Temperature ◽

Flow Through ◽

Run Up ◽

Compact Design ◽

Probe Measurements

For this work, reality effects, more precisely backward-facing steps (BFSs) and forward-facing steps (FFSs), and their influence on the flow through a two-stage two-spool turbine rig under engine-relevant conditions were experimentally investigated. The test rig consists of an high pressure (HP) and an low pressure (LP) stage, with the two rotors rotating in opposite direction with two different rotational speeds. An S-shaped transition duct, which is equipped with turning struts (so-called turning mid turbine frame (TMTF)) and making therefore a LP stator redundant, connects both stages and leads the flow from a smaller to a larger diameter. This test setup allows the investigation of a TMTF deformation, which occurs in a real aero-engine due to non-uniform warming of the duct during operation—especially during run up—and causes BFSs and FFSs in the flow path. This happens for nonsegmented ducts, which are predominantly part of smaller engines. In the case of the test rig, steps were not generated by varying temperature but by shifting the TMTF in horizontal direction while the rotor and its casing were kept in the same position. In this way, both BFSs and FFSs between duct endwalls and rotor casing could be created. In order to avoid steps further downstream of the interface between HP rotor and TMTF, the complete aft rig was moved laterally too. In this case, the aft rig incorporates among others the LP rotor, the LP rotor casing, and the deswirler downstream of the LP stage. In order to catch the influence of the steps on the whole flow field, 360 deg rake traverses were performed downstream of the HP rotor, downstream of the duct, and downstream of the LP rotor with newly designed, laser-sintered combi-rakes for the measurement of total pressure and total temperature. Only the compact design of the rakes, which can be easily realized by additive manufacturing, makes the aforementioned 360 deg traverses in this test rig possible and allows a number of radial measurements positions, which is comparable to those of a five-hole probe. To get a more detailed information about the flow, also five-hole probe measurements were carried out in three measurement planes and compared to the results of the combi-rakes.

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