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Fulltext An innovations-based noise cancelling technique on inverse kepstrum whitening filter and adaptive FIR filter in beamforming structure

Jeong J

Sensors (Basel), 2011;11(7):6816-41.
PMID: 22163987 DOI: 10.3390/s110706816

This paper presents an acoustic noise cancelling technique using an inverse kepstrum system as an innovations-based whitening application for an adaptive finite impulse response (FIR) filter in beamforming structure. The inverse kepstrum method uses an innovations-whitened form from one acoustic path transfer function between a reference microphone sensor and a noise source so that the rear-end reference signal will then be a whitened sequence to a cascaded adaptive FIR filter in the beamforming structure. By using an inverse kepstrum filter as a whitening filter with the use of a delay filter, the cascaded adaptive FIR filter estimates only the numerator of the polynomial part from the ratio of overall combined transfer functions. The test results have shown that the adaptive FIR filter is more effective in beamforming structure than an adaptive noise cancelling (ANC) structure in terms of signal distortion in the desired signal and noise reduction in noise with nonminimum phase components. In addition, the inverse kepstrum method shows almost the same convergence level in estimate of noise statistics with the use of a smaller amount of adaptive FIR filter weights than the kepstrum method, hence it could provide better computational simplicity in processing. Furthermore, the rear-end inverse kepstrum method in beamforming structure has shown less signal distortion in the desired signal than the front-end kepstrum method and the front-end inverse kepstrum method in beamforming structure.

Matched MeSH terms: Bioengineering/methods*
Bioengineering the innate vasculature of complex organs: what have we learned so far

Wijesekara P, Ng WH, Feng M, Ren X

Curr Opin Organ Transplant, 2018 12;23(6):657-663.
PMID: 30234735 DOI: 10.1097/MOT.0000000000000577

PURPOSE OF REVIEW: Engineering vasculature that meets an organ's specific physiology and function is a fundamental step in organ bioengineering. In this article, we review approaches for engineering functional vasculature for organ bioengineering, with an emphasis on the engineering of organ-specific endothelium and vasculature.
RECENT FINDINGS: Recent advances in hydrogel-based engineering of vascularized organ bud enable vascular regeneration in self-assembled cellular niche containing parenchymal and stromal cells. The emerging technology of whole-organ decellularization provides scaffold materials that serve as extracellular niche guiding vascular regeneration to recapitulate native organ's vascular anatomy. Increasing morphological and molecular evidences suggest endothelial heterogeneity across different organs and across different vascular compartments within an organ. Deriving organ-specific endothelium from pluripotent stem cells has been shown to be possible by combining endothelial induction with parenchymal differentiation.
SUMMARY: Engineering organ-specific vasculature requires the combination of organ-specific endothelium with its unique cellular and extracellular niches. Future investigations are required to further delineate the mechanisms for induction and maintenance of organ-specific vascular phenotypes, and how to incorporate these mechanisms to engineering organ-specific vasculature.

Matched MeSH terms: Bioengineering/methods*
Special issue on algae bioprocess engineering

Show PL, Chew KW, Chang JS

Bioengineered, 2020 12;11(1):188.
PMID: 32077364 DOI: 10.1080/21655979.2020.1729546
Matched MeSH terms: Bioengineering/methods*
Fulltext Engineering artificial machines from designable DNA materials for biomedical applications

Qi H, Huang G, Han Y, Zhang X, Li Y, Pingguan-Murphy B, et al.

Tissue Eng Part B Rev, 2015 Jun;21(3):288-97.
PMID: 25547514 DOI: 10.1089/ten.TEB.2014.0494

Deoxyribonucleic acid (DNA) emerges as building bricks for the fabrication of nanostructure with complete artificial architecture and geometry. The amazing ability of DNA in building two- and three-dimensional structures raises the possibility of developing smart nanomachines with versatile controllability for various applications. Here, we overviewed the recent progresses in engineering DNA machines for specific bioengineering and biomedical applications.

Matched MeSH terms: Bioengineering/methods
Fulltext Review of the socket design and interface pressure measurement for transtibial prosthesis

Pirouzi G, Abu Osman NA, Eshraghi A, Ali S, Gholizadeh H, Wan Abas WA

ScientificWorldJournal, 2014;2014:849073.
PMID: 25197716 DOI: 10.1155/2014/849073

Socket is an important part of every prosthetic limb as an interface between the residual limb and prosthetic components. Biomechanics of socket-residual limb interface, especially the pressure and force distribution, have effect on patient satisfaction and function. This paper aimed to review and evaluate studies conducted in the last decades on the design of socket, in-socket interface pressure measurement, and socket biomechanics. Literature was searched to find related keywords with transtibial amputation, socket-residual limb interface, socket measurement, socket design, modeling, computational modeling, and suspension system. In accordance with the selection criteria, 19 articles were selected for further analysis. It was revealed that pressure and stress have been studied in the last decaeds, but quantitative evaluations remain inapplicable in clinical settings. This study also illustrates prevailing systems, which may facilitate improvements in socket design for improved quality of life for individuals ambulating with transtibial prosthesis. It is hoped that the review will better facilitate the understanding and determine the clinical relevance of quantitative evaluations.

Matched MeSH terms: Bioengineering/methods*
Bioengineering of microbial transglutaminase for biomedical applications

Chan SK, Lim TS

Appl Microbiol Biotechnol, 2019 Apr;103(7):2973-2984.
PMID: 30805670 DOI: 10.1007/s00253-019-09669-3

Microbial transglutaminase (mTGase) is commonly known in the food industry as meat glue due to its incredible ability to "glue" meat proteins together. Aside from being widely exploited in the meat processing industries, mTGase is also widely applied in other food and textile industries by catalysing the formation of isopeptide bonds between peptides or protein substrates. The advancement of technology has opened up new avenues for mTGase in the field of biomedical engineering. Efforts have been made to study the structural properties of mTGase in order to gain an in-depth understanding of the structure-function relationship. This review highlights the developments in mTGase engineering together with its role in biomedical applications including biomaterial fabrication for tissue engineering and biotherapeutics.

Matched MeSH terms: Bioengineering/methods*
Bioengineering of the Plant Culture of Capsicum frutescens with Vanillin Synthase Gene for the Production of Vanillin

Chee MJ, Lycett GW, Khoo TJ, Chin CF

Mol Biotechnol, 2017 Jan;59(1):1-8.
PMID: 27826796 DOI: 10.1007/s12033-016-9986-2

Production of vanillin by bioengineering has gained popularity due to consumer demand toward vanillin produced by biological systems. Natural vanillin from vanilla beans is very expensive to produce compared to its synthetic counterpart. Current bioengineering works mainly involve microbial biotechnology. Therefore, alternative means to the current approaches are constantly being explored. This work describes the use of vanillin synthase (VpVAN), to bioconvert ferulic acid to vanillin in a plant system. The VpVAN enzyme had been shown to directly convert ferulic acid and its glucoside into vanillin and its glucoside, respectively. As the ferulic acid precursor and vanillin were found to be the intermediates in the phenylpropanoid biosynthetic pathway of Capsicum species, this work serves as a proof-of-concept for vanillin production using Capsicum frutescens (C. frutescens or hot chili pepper). The cells of C. frutescens were genetically transformed with a codon optimized VpVAN gene via biolistics. Transformed explants were selected and regenerated into callus. Successful integration of the gene cassette into the plant genome was confirmed by polymerase chain reaction. High-performance liquid chromatography was used to quantify the phenolic compounds detected in the callus tissues. The vanillin content of transformed calli was 0.057% compared to 0.0003% in untransformed calli.

Matched MeSH terms: Bioengineering/methods
Safety and efficacy of the COMBO bio-engineered stent in an all-comer PCI cohort: 1-Year final clinical outcomes from the MASCOT post-marketing registry

Colombo A, Chandrasekhar J, Aquino M, Ong TK, Sartori S, Baber U, et al.

Int J Cardiol, 2019 05 15;283:67-72.
PMID: 30826192 DOI: 10.1016/j.ijcard.2019.01.053

BACKGROUND: The COMBO stent (OrbusNeich Medical, Ft. Lauderdale, Florida) is a new-generation bio-engineered drug eluting stent, combining an abluminal coating of a bioabsorbable polymer matrix for sustained release of sirolimus and luminal anti-CD34 coating for endothelial progenitor cell capture and rapid endothelialization.
METHODS: The Multinational Abluminal Sirolimus Coated BiO-Engineered StenT (MASCOT) registry was a prospective post-marketing study conducted from June 2014-May 2017 across 60 centers globally. Patients were eligible if COMBO stent implantation was attempted, and they received dual antiplatelet therapy (DAPT) per local guidelines. Follow-up was conducted by trained research staff at 1, 6 and 12 months by phone or clinic visit to capture clinical events and DAPT cessation events. The primary endpoint was 1-year target lesion failure (TLF), composite of cardiac death, non-fatal myocardial infarction not clearly attributable to a non-target vessel, or ischemia-driven target lesion revascularization.
RESULTS: A total of 2614 patients were enrolled over the study period with 96.7% completion of 1-year follow-up. The mean age of enrolled patients was 62.9 ± 11.2 years and 23.0% were female. Diabetes mellitus was present at baseline in 33.5%. A total of 56.1% patients underwent PCI for acute coronary syndrome (ACS). The 1-year primary endpoint of TLF occurred in 3.4% patients (n = 88). Definite stent thrombosis occurred in 0.5% patients (n = 12).
CONCLUSION: The MASCOT post marketing registry provides comprehensive safety and efficacy outcomes following contemporary PCI using the novel COMBO stent in an all-comer population. This platform is associated with low rates of 1-year TLF and ST. CLINICALTRIALS.
GOV IDENTIFIER: NCT02183454.

Matched MeSH terms: Bioengineering/methods