Biological Devices Research Articles

Closing Loopholes in the Federal Research Regulations: Some Practical Problems

Shamoo and Schwartz (2008) argue that to protect the dignity, rights, and welfare of people who participate in research, the U. S. should close existing loopholes in the federal regulations. Currently, federal regulations only apply to research conducted or funded by one of the 17 federal agencies that accept the Common Rule (45 C. F. R. 46), research that will be used to support an application for a new drug, biologic, and medical device regulated by the Food and Drug Administration, or research conducted to generate data to submit to the Environmental Protection Agency for regulatory purposes (Shamoo and Schwartz 2008, Resnik 2007). The Common Rule is the most influential of all of these regulations, because most academic institutions the receive federal funding have decided to apply the Common Rule to all human subjects research under their authority, regardless of the source of funding (Gunsalus 2006).

Beyond mood and modality: epistemic modality markers as hedges in research articles. A cross-disciplinary study

In this paper a cross-disciplinary study of the use of epistemic markers as hedging rhetorical strategies in research articles in English is carried out. Based on computer readable data, and combining quantitative and qualitative methods, the article argues that the use of modal expressions can be better explained as reflecting the strategies of hedging used by writers for dealing with the social conditions involved in the event of publishing an article, which is addressed to different discourse communities. Three different disciplines (Marketing, Biology and Mechanical Engineering) belonging to the soft knowledge vs. hard knowledge discipline continuum are investigated here. Our analysis of hedging in these three different disciplines has revealed, not only that there are differences in the occurrence of hedges in the RAs selected, but also that these differences depend on the nature of the data used for the research in each discipline. Each discipline tries to fulfil social needs in different areas. The sociological features of each discipline may be shaping the discourse in their RAs differently. This is reflected in the varied presence of hedging devices in Marketing, Biology and Mechanical Engineering research articles.

Suture or Hemostatic Agent During Laparoscopic Partial Nephrectomy? A Randomized Study Using a Hypertensive Porcine Model

To compare the efficacy of 3 biologic hemostatic devices with that of conventional suture during laparoscopic partial nephrectomy (LPN) in a hypertensive porcine model. Improving hemostasis, urinary tract closure, and the warm ischemia (WI) time are important in the development of LPN. A total of 40 pigs were randomized prospectively into 4 groups before bilateral LPN. Right LPN involved 30% of the renal parenchyma without a urinary tract opening, and left LPN involved 40% of the renal parenchyma with a urinary tract opening. The renal section was treated with fibrin/thrombin sealant, fibrin glue, thrombin/gelatin granules, and conventional suture in groups 1, 2, 3, and 4, respectively. At 10 days postoperatively, left retrograde pyelography was performed. The pigs were then killed and the kidneys sent for pathologic analysis. The main criteria were the estimated blood loss, perioperative WI time, leaking pressure during retrograde pyelography, and parenchyma necrotic-induced lesions. The estimated blood loss was lower in the pigs treated with either thrombin/gelatin granules or suture (P < .001). The use of thrombin/gelatin granules decreased the WI time compared with the use of suture (P < .001). However, the leaking pressure was greater in the pigs treated with suture (P < .01). The mean area of necrosis around the renal section was shorter when no suturing was performed (P < .01). The use of thrombin/gelatin granules alone controlled hemostasis as effectively as suture and significantly decreased the WI time. However, conventional suture of the urinary tract, when opened, should be considered. Additional evaluation in humans is required before any clinical recommendation can be made.

Physical Limits on Computation by Assemblies of Allosteric Proteins

Assemblies of allosteric proteins are the principle information processing devices in biology. Using the Ca2+-sensitive cardiac regulatory assembly as a paradigm for Brownian computation, I examine how system complexity and system resetting impose physical limits on computation. Nearest-neighbor-limited interactions among assembly components constrain the topology of the system's macrostate free energy landscape and produce degenerate transition probabilities. As a result, signaling fidelity and deactivation kinetics cannot be simultaneously optimized. This imposes an upper limit on the rate of information processing by assemblies of allosteric proteins that couple to a single ligand type.

ANALYSIS OF VOLTAGE SIGNALS BY FLICKER NOISE METHODOLOGY APPLIED ON POROUS SILICON FILMS GROWTH

The Flicker Noise Analysis methodology is applied on voltage signals recorded when the electrochemical etching of crystalline surfaces of silicon is performed. The porous silicon material resulting from this procedure is composed of nanocrystals possessing remarkable properties which can be employed in the development of optical, electronic, or biological sensor devices. As a result of the analysis, two dynamic processes during the electrochemical reaction have been identified: one related to the dissolution of the crystalline matrix and the other related to the porous morphology itself.

PH-Dependent Stability of Self-Assembled Monolayers on Gold

Self-assembled monolayers (SAMs) have attracted considerable attention because of their wide applications to biosensors, optoelectronic devices, control of wettability and biocompatibility, corrosion resistance, etc. Among various types of SAMs formed on numerous kinds of substrates, the SAMs of alkanethiols on gold have extensively been studied, primarily because it is relatively easy and simple to form well-organized monolayers on gold compared with the methods used for other substrates. In addition, the gold surface enables us to effortlessly use analytical techniques, including surface plasmon resonace spectroscopy, quartz crystal microbalance, reflection absorption infrared spectroscopy and ellisometry, in the mechanistic studies and potential applications of SAMs. Especially, the SAMs of long-chain alkanethiols with ω-functional groups, such as OH, COOH, and NH2, have attracted a great deal of interest, because the use of these alkanethiols would yield more interesting properties of surfaces through post-modification reactions, such as nucleophilic substitution, nucleophilic addition, esterification, and acylation, in addition to their own chemical properties. For example, the surface modifications of OH-, COOH-, and NH2-terminated SAMs have been used for the attachment of biopolymers, such as oligonucleotides and peptides, onto gold surfaces, which is the essential step for the application to biotechnology. Since the post-modifications and applications of SAMs are performed under various conditions of temperature, pH and solvents, studies on the stability of SAMs against potentially destructive conditions of monolayers are important for wider applications of SAMs as well as design of post-modification reactions. The air-stability of alkanethiolbased monolayers on gold was studied with long-chain alkanethiols for one week to several months. Their longterm stability was also investigated in biological media, because biomaterials and biological devices, which use SAMs as a platform, necessitate prolonged exposure to the biological media. Recently, the effect of storage conditions, such as air, N2, ethanol, phosphate buffer and H2O, on the stability of mixed poly(ethylene oxide)-thiol SAMs was studied to ensure the long-term preservation of biosensing property. In addition to these studies on the stability of SAMs, the pH dependency of the stability of SAMs in aqueous solutions is to be established, since the numerous surface modification reactions and applications of SAMs are performed at various pH values. As a related work, the dissociation phenomena of thiolate ligands from the surface of cadmium chalcogenide nanocrystals have been examined by varying the pH values. In this work, we investigated pHdependent stability of alkanethiol SAMs with various functional groups at their terminals, in order to give a basic but crucial information for post-modifications and other SAMbased reactions. The SAMs of long-chain alkanethiols with CH3, OH, COOH, or NH2 group were prepared on gold, and their stability was studied for one week at pH values from 1 to 14 by measuring the changes in the ellipsometric thickness. For the preparation of the SAMs on gold, a clean gold substrate was immersed for 20 h in each alkanethiol solution of HS-(CH2)15-CH3, HS-(CH2)16-OH, HS-(CH2)15-COOH, or HS-(CH2)16-NH2. The SAMs were characterized by FTIR spectroscopy (Figure 1). Figure 1a shows the IR peaks

Local Concentration of Gel Phase Domains in Supported Lipid Bilayers under Light Irradiation in Binary Mixture of Phospholipids Doped with Dyes for Photoinduced Activation

Recently, lipid bilayers supported on solid substrates are considered to offer potential as biological devices utilizing biological membranes and membrane proteins. In particular, artificially patterned supported bilayers hold great promise for the development of biological devices. In this study, we show control of the formation and location of phase-separated domain structures by light irradiation for gel phase and liquid-crystalline phase separation structures in a DMPC-DOPC binary lipid bilayer tagged with dye molecules on SiO2/Si substrates. Upon light irradiation, the gel phase domain structures disappeared from the phase-separated bilayers. This disappearance indicates that the light irradiation causes a local increase in the temperature of the lipid bilayer. In this disappearance phenomenon, the photoinduced activation of dye lipids, e.g. fluorescent lipids, is considered to play an important role, since the same phenomenon does not occur in lipid bilayers that have a low concentration of dye lipids. Thus, the local increase in temperature is propagated by light absorption of the dye lipid and subsequent photoinduced activation of nonradiative molecular vibrations. Subsequent interruption of the photoinduced activation for molecular motion allowed the gel phase domain structures to precipitate and grow again. Moreover, the domain area fraction remaining after the photoinduced activation was higher than that before the photoinduced activation. This result indicates that the local increase in temperature propagated by dye-excitation enhances formation of the gel phase domains. By utilizing this phenomenon, we could preferentially induce formation of domain structures within the light-irradiated regions. This technique could be the basis for a new patterning technique based on domain structures. Moreover, these domain structure patterns can be eliminated by increasing the temperature, allowing rewritable patterning.

Acoustic waves in structure “piezoelectric plate–polymeric nanocomposite film”

Paper is devoted to the investigation of SH 0 acoustic waves propagating in structure “piezoelectric plate–polymeric nanocomposite film”. The analysis was carried out by the example of the polymeric nanocomposite film based on high-pressure polyethylene with various contents of CdS nanoparticles and lithium tantalate and lithium niobate plate. The resonant attenuation of investigated waves for the certain ratios of plate and film thicknesses was found. The obtained results open the prospects of the development of structures for SH 0 waves consisting of nanocomposite polymeric substrates and thin piezoelectric plates. Such structures may be useful for development of various thermostable chemical and biological sensors and signal processing devices.

Refinement and standardization of synthetic biological parts and devices

The ability to quickly and reliably engineer many-component systems from libraries of standard interchangeable parts is one hallmark of modern technologies. Whether the apparent complexity of living systems will permit biological engineers to develop similar capabilities is a pressing research question. We propose to adapt existing frameworks for describing engineered devices to biological objects in order to (i) direct the refinement and use of biological 'parts' and 'devices', (ii) support research on enabling reliable composition of standard biological parts and (iii) facilitate the development of abstraction hierarchies that simplify biological engineering. We use the resulting framework to describe one engineered biological device, a genetically encoded cell-cell communication receiver named BBa_F2620. The description of the receiver is summarized via a 'datasheet' similar to those widely used in engineering. The process of refinement and characterization leading to the BBa_F2620 datasheet may serve as a starting template for producing many standardized genetically encoded objects.

Setting the standard in synthetic biology

Standards for characterization, manufacture and sharing of information about modular biological devices may lead to a more efficient, predictable and design-driven genetic engineering science.

대퇴골(Femur)고정용 골 금속판 제작 및 강도 평가

Study was developed the metallic plate for fixation in the femur fracture and plates has a firm place in fracture treatment. This plates can be stabilized for fracture fixation as well as biological and dynamical device. The device's designation and sizing has a optimization with bending structural stiffness and strength, known meaning that is reliable regardless of the plate by the short type and long type. The bending strength of the curved metallic long plate has to evaluate a 11,000N and the bending strength of the curved metallic short plate has to evaluate a 6,525N. This see the X-ray image of bending angle made certain of 15° at number 2 and same 82.87° at number 2, 4, 5, 7, 8, 9, 10 by outside angle, and confirmed 25.26° at number 3, 3.68° at number 6, 15.64° at number 9 by inside angle. This study shows that keep up the metallic plate for fixation in the femur fracture through X-ray Image and the device can be used to support Revision case of Hip Implant and to use a case of Hip screw compression of Hip Neck Fracture. Short plate have a wrapping of femur and long plate have to preserve a pole of femur.

Flicker noise analysis of laminar voltage signals of porous silicon films

A special kind of noise analysis is applied on voltage signals recorded when the electrochemical etching of crystalline surfaces of silicon is performed. The resulting material, named porous silicon (PS), exhibits nanocrystalline formations and has interesting properties which can be employed in the development of optical, electronic or biological sensor devices. These characteristics depend mostly on the resulting morphology after etching. The flicker noise analysis is a suitable way to extract information on the dynamics of the pore formation and its correlation with morphology. This study shows some of the analysis results.

Inkjet printing - the physics of manipulating liquid jets and drops

Over the last 30 years inkjet printing technology has been developed for many applications including: product date codes, mailing shots, desktop printing, large-area graphics and, most recently, the direct writing of materials to form electronic, biological, polymeric and metallic devices. The new non-graphical applications require higher print rates, better resolution and higher reliability while printing more complex, non-Newtonian and heavily solids-loaded liquids. This makes the understanding of the physics involved in the precise manipulation of liquid jets and drops ever more important. The proper understanding and control of jet formation and subsequent motion of the jetted materials requires physical studies into material properties at very high shear rates, acoustic modes in print heads, instabilities of jets, drop formation, drop motion, stretching of fluid ligaments, the role of polymers in jet break up, electrical charging of drops and the aerodynamic and electrostatic interaction of jets and drops in flight. Techniques for observation, measurement and analysis are evolving to assist these studies. This paper presents some examples of the application of physics to understanding and implementing inkjet printing, including recent work at the Cambridge Inkjet Research Centre.

Building a better cell trap: Applying Lagrangian modeling to the design of microfluidic devices for cell biology

In this report, we show how computational fluid dynamics can be applied to the design of efficient hydrodynamic cell traps in microfluidic devices. Modeled hydrodynamic trap designs included a large, multiple-aperture “C-type” sieve for trapping hundreds of cells, flat single-aperture arrays for single cells, and “U-type” hydrodynamic structures with one or two apertures to confine small clusters of cells (∼10–15 cells per trap). Using 3T3 cells as a model system, the motion of each individual cell was calculated using a one-way coupled Lagrangian method. The cell was assumed to be a solid sphere, and interactions with other cells were only considered when a cell sedimented in the trap. The ordinary differential equations were solved along the cell trajectory for the three components of the velocity and location vector by using the Rosenbrock method based on an adaptive time-stepping technique. Validation of the predictive value of modeling, using 3T3 cells flowed through microfluidic devices containing “U-type sieves” under the simulation flow parameters, showed excellent agreement between experiment and simulation with respect to cell number per trap and the uniformity of cell distribution within individual microchambers. For applications such as on-chip cell culture or high-throughput screening of cell populations within a lab-on-a-chip environment, Lagrangian simulations have the potential to greatly simplify the design process.

Enhancement of the enzymatic activity of activated coagulation factor IX by anti-factor IX antibodies

Enhancement of the enzymatic activity of activated coagulation factor IX by anti-factor IX antibodies

Poly(ethylene glycol)-Mediated Synthesis of Hollow ZnS Microspheres

Hollow ZnS microspheres composed of nanoparticles have been successfully synthesized by a facile poly(ethylene glycol) (PEG) mediated hydrothermal route. The size of the hollow ZnS microspheres could be adjusted easily by controlling the chain length of PEG. The formation of these hollow microspheres is attributed to the oriented aggregation of ZnS nanorods around a polymer−Zn2+ complex spherical framework structure. Different Raman and photoluminescence characters have been observed for the hollow ZnS microspheres with and without PEG. The hollow ZnS microspheres will find potential application in optical and biological devices.

Biological attachment devices: exploring nature's diversity for biomimetics

Many species of animals and plants are supplied with diverse attachment devices, in which morphology depends on the species biology and the particular function in which the attachment device is involved. Many functional solutions have evolved independently in different lineages of animals and plants. Since the diversity of such biological structures is huge, there is a need for their classification. This paper, based on the original and literature data, proposes ordering of biological attachment systems according to several principles: (i) fundamental physical mechanism, according to which the system operates, (ii) biological function of the attachment device, and (iii) duration of the contact. Finally, we show a biomimetic potential of studies on biological attachment devices.

Adjuvant therapies of bone graft around non-cemented experimental orthopedic implants stereological methods and experiments in dogs

Revision arthroplasty is a challenging aspect of the otherwise quite successful area of joint replacement surgery. The instable interaction between implant and host bone has often initiated a destructive process of inflammation and osteolysis, rendering the revision site sclerotic and with insufficient bone stock. One way of dealing with this is to build up a bed of tightly packed morselized bone graft to support the revision implant in a procedure often referred to as impaction grafting. Fresh frozen morselized femoral head allograft is the gold standard material for impaction grafting of the large defects usually involved in revision arthroplasty. The clinical outcome does not match that of primary arthroplasties. Implant subsidence is greater, implant survival shorter, and the bone graft is often not incorporated into living bone. The studies constituting this thesis have investigated ways of improving early implant fixation and bone graft incorporation. All studies used the same experimental canine model of early fixation and osseointegration of uncemented implant components inserted into a bed of impacted bone graft. Study I compared bone grafted implants where the morselized allograft was used alone or had been added rhBMP-2, the bisphosphonate pamidronate or a combination of the two. The main object was to see wether the previously observed growth factor related accelerated allograft resorption could be counteracted by the addition of an anti-catabolic drug. The study also compared HA-coated and non-coated porous Ti implants. The untreated control implants had better mechanical fixation than all other treatment groups. RhBMP-2 raised the total metabolic turnover of bone within the allograft with a net negative result on implant fixation. Pamidronate virtually blocked bone metabolism, also when combined with rhBMP-2. The HA-coated implants had more than twice as good mechanical fixation and improved osseointegration compared to the corresponding Ti implants. Study II investigated the addition of a bovine bone matrix lyophilisate (Colloss) to the allograft in three different doses. The main object was to see, whether the addition of a biological delivery device of low-dose osteogenic growth factors could provide a sufficient signal to increase the bioactivity of the bone graft without also yielding mechanical instability through increased allograft resorption. Allograft resorption increased with increased signal dose, but not to the extent that it affected implant fixation negatively at the observational time point. Mechanical implant fixation was doubled, and implant osseointegration and graft incorporation were improved. Study III compared a beta-TCP ceramic bone graft substitute (Ossaplast) with and without an osteogenic signal (Colloss E) to morselized allograft with and without the same signal. The object was to investigate, whether the addition of an osteogenic stimulus to a bio ceramic could replace biological allograft bone. The addition of an osteogenic signal improved early osseointegration of implants grafted with beta-TCP granules and increased their mechanical implant fixation to a level comparable to the allografted implants. All studies I-III confirmed that the topical addition of an osteogenic signal could increase implant osseointegration and the formation of new bone within a grafted defect. Another striking observation was the near-complete absence of fibrous tissue in the treated groups. The osseointegration of ceramic bone grafts improves when both the osteoconductive as well as the osteogenic components of bone are substituted. The effect on implant fixation of devices and pharmaceuticals that influence bone metabolism can be difficult to predict, as shown in study I. There seems to be a therapeutic window for these substances. This must be further explored prior to clinical use, as the adverse effects of overdosing bone anabolic and anti-catabolic substances can be detrimental.

Rhode Island disaster initiative

The Rhode Island Disaster Initiative (RIDI) is providing research in the areas of readiness, technology and training to address the significant gaps that remain in real-time medical response to events involving the use of weapons of mass destruction; terrorist use of chemical, biological, radiological, nuclear and explosive devices; mass casualty incidents and toxic industrial chemical and material accidents. Through a series of focused studies and full-scale exercises, RIDI is examining the underpinnings of common failures in disaster response, researching a number of potential best practice solutions to these failures and disseminating recommended solutions. Failed logistics, coordination, communication and inadequate decontamination practices are among the addressed areas.

Printing Light Harvesting Biological &amp;#x201C;Devices&amp;#x201D; and other Functional Materials Applicable to Organic Photovoltaics

Many processing steps in the manufacturing of organic photovoltaics require solution processing. Inkjet printing is a facile method for depositing solutions into patterned thin films. Piezoelectric inkjet printing is a thermally consistent process, thereby protecting the tertiary structure of organic molecules that convert optical power to electrical power. We have taken several steps back from device manufacturing and worked out the details of inkjet printing light harvesting bacteria, more specifically photosynthetic cyanobacteria. Each individual single-celled organism is a functioning biological photovoltaic device that works with only the input of water as an electron donor for the photosynthetic reaction. In addition, these cells harvest photons from a variety of wavelengths so that they function more efficiently in heterogeneous light environments. An added bonus is that their byproduct is pure oxygen and conversely, they use C02 as a food source, thus removing carbon dioxide from the atmosphere. In these biological organic photovoltaic devices, a series of photochemical reactions occur through a thylakoid-containing internal membrane structure underneath their gelatinous cell wall. We will show the successful thin film patterning of these cells, and we will also show their light emission characteristics. In addition, we will show their carbohydrate production yields highlighting their ability to use light to form energy that can be converted easily into electricity. Finally, we will show other patterned thinfilms of organic photovoltaic relevant materials including conductive silver used in cathodes, carbon nanotubes used as transparent conductors, conjugated polymers used in the active layer and quantum dots, band gap acceptor materials that also function in non-white light environments. Finally, this talk will discuss the impact of inkjet printing on the photovoltaic market and highlight the research efforts of leaders in this field.