bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selective Multilayer Thin-Film Development in Insects
Authors: Miaoulis Ioannis N. , Tada Haruna , Mann Seth , Wong Peter Y. 
Published: September 2024

Abstract
Multilayer structures of biological thin films play numerous roles in insects, plants, lizards, and birds. Due to microscale radiative effects, small changes in the film thicknesses result in large changes in reflected sunlight and solar absorption. Through selective variations of the thin-film thicknesses and structures, nature has used multilayer structures for a variety of purposes. In butterflies, the thin films result in a colorful iridescence that is used for signaling, courting, camouflage, and display. Moreover, these thin films appear to be multifunctional; the light not reflected is absorbed for thermoregulation purposes. Variations of thin films in butterfly scales of different species results in different spectral and total reflectivity characteristics. An experimental apparatus was used to measure the spectral reflectivity from single scales, ∼100 μm long. Images of the illuminated scales reveal the effect of the microstructure on the optical properties.
Mass Transport Considerations for Micro-Gravity Cell Cultures in the NASA/JSC Bioreactor
Authors: Kleis Stanley J. , Begley Cynthia M. 
Published: September 2024

Abstract
The current NASA/JSC rotating wall perfused bioreactor vessel was developed to provide an environment for the culture of mammalian cells with a controllable and low level of mechanical stress. The accurate prediction of the transport of the nutrients and oxygen to the cells requires a detailed knowledge of the flow field, the concentration distributions of various quantities within the fluid phase, and the motion of the microcarriers with cells relative to the fluid phase. Computed velocity fields were used to numerically solve for the transient scalar concentration distributions of oxygen within the vessel. Oxygen was chosen as the representative scalar to study because of the relatively high cell requirements for oxygen and the low solubility of oxygen in the fluid medium. Results of the numerical simulations show that the strong secondary flow, driven by the viscous pump, produces rapid distribution of inlet concentrations which reduce concentration differences within the vessel while keeping the concentration difference between the inlet and outlet relatively high.
The trajectories of cells on microcarriers for different operating conditions were predicted for operation under micro-gravity conditions. The lack of gravity causes the slightly more dense cells and microcarriers to move under the influence of the pressure gradient, viscous shear, and centripetal acceleration fields. Results from the numerical solution of the resulting equations are compared with data from flight experiments flown on STS-70 in July, 1995.
Mass Transfer Characteristics of NASA Bioreactors by Numerical Simulation
Authors: Tsao Yow-Min D. , Gonda Steve R. , Pellis Neal R. 
Published: September 2024

Abstract
In this study, two bioreactors, each consisting of two concentric independently rotating cylinders, were evaluated by using computational fluid dynamics. The relative motion between the culture fluid (125 ml in the low aspect bioreactor and 250 ml in the high aspect bioreactor) and particles (150–3,000 micron diameter) was generated by a secondary flow resulting from different rotation rates of the two concentric cylinders. This study included computation of flow fields, perfusion effects, particle trajectories, shear forces and Sherwood number. Results indicate that the larger particles were suspended close to the end caps of the bioreactor, and smaller particles followed the streamline of the secondary flow and were distributed across the reactor vessel. Media perfusion at 5–20 ml/min had little effect on the overall flow field of the bioreactor, because the location of the inlet/exit perfusion ports short-circuited the extent of perfusion flow across the bioreactor. The aspect ratio of the vessel played an important role in the generation of secondary flow. The larger aspect ratio vessel required both a larger differential and faster rates of rotation to keep particles suspended. Particles located near the end caps in both vessels were subjected to higher forces. The force on the particles in the 125 ml vessel was half that on the particles in the 250 ml vessel. The Sherwood number indicated that the best mass-transfer conditions were present for larger particles in the larger aspect ratio vessel. In summary, maximizing the performance of a bioreactor in space requires minimizing the shear force generated by fluid flow, yet the flow movement must be enough to transfer nutrients. The results from this study indicate that four factors are crucial in this regard: (1) a uniform flow field, (2) a low aspect ratio vessel, (3) a well designed perfusion loop and (4) sufficient nutrient transfer to support cell growth.
Development of Closed Systems for Ex Vivo Cell Processing: Utility in Cell and Gene Therapy
Authors: Hardwick R. Alan , Levine Bruce L. , June Carl H. , Cotte Julio , Malech Harry L. , Butz Robert E. , Carter Charles S. , Maples Phillip B. 
Published: September 2024

Abstract
Two examples are described in which cells were processed in a closed sterile fluid path by using custom-designed instruments, plastic bags and tubing sets, and a sterile connection device. In the first example, nucleated blood cells were collected from HIV+ patients. These cells were enriched for CD4+ cells and the CD4+ cells were expanded in the presence of immobilized CD3 and CD28 antibodies. The cells were then concentrated, washed, and re-infused. For the largest batches this resulted in 2.20 × 1010 cells with 86% viability and a CD4+ cell purity ≥ 95%. In two out of three re-infused patients, CD4+ cell counts have remained elevated. In the second example, nucleated blood cells were collected from chronic granulomatous disease (CGD) pauents. CD34+ progenitor cells were immunomagnetically selected and then transfected with a retrovirus containing a corrected copy of the p47 gene. This resulted in 10%–30% of the CD34+ cells being successfully transduced. After transduction, the cells were washed and re-infused. Corrected neutrophils were transiently detected in all five patients. The closed system approach to cell processing is particularly well-suited to clinical trials in cell therapy and gene therapy.
Hematopoietic Stem Cell Engineering: The Magic Bullet of the Next Millenium?
Authors: Gee A. P. 
Published: September 2024

Abstract
Hematopoietic stem cell [HSC] therapy has its origins as hematological rescue following marrow ablative high-dose therapy for refractory cancers and myelodysplastic syndromes. In its simplest form, bone marrow is collected from a tissue-matched related normal donor and intravenously infused into the patient who has usually received high-dose chemo/radiotherapy for his or her disease. The stem cells migrate to the marrow spaces, where they multiply and differentiate to restore blood cell-forming activity and immune defenses in the recipient Restrictions in the availability of tissue-matched marrow donors have prompted investigations into new sources of stem cells. These include use of the autologous marrow, which is collected from the patient and cryopreserved prior to therapy. The risk of tumor contamination in these grafts has resulted in the development of numerous methods to purge cancer cells from marrow ex vivo, or to enrich stem cells from the graft. This provided one of the earliest clinical applications for monoclonal antibodies and immunomagnetic cell separation. Another approach has been to use tissue-matched unrelated volunteer marrow donors, or grafts from mismatched family members. In both cases, ex vivo removal of T lymphocytes from the graft is advisable to prevent these cells initiating a severe or fatal reaction in the recipient - graft-versus-host disease. Recent studies have shown that recombinant human growth factors can be used to stimulate migration of HSC from the marrow into the blood, from which they are collected by automated cell separators, obviating the need for harvesting marrow under general anesthesia. The same growth factors have been used to expand and differentiate HSC ex vivo, with the hope that clinical grafts could ultimately be grown in the laboratory from a few milliliters of blood or marrow. Transplants have also been performed using placental/umbilical cord blood as the HSC source, and there are some indications that these cells may be more suitable for mismatched transplants. Genetic manipulation of stem cells can be used to correct a number of inherited diseases, and ultimately may allow specific beneficial properties to be introduced into blood-derived cells e.g. drug resistance into stem cells - to allow higher doses of chemotherapy to be used without destroying the bone marrow. The rapid expansion in this field of medicine, combined with advances in molecular and cellular biology offer the promise of stem cell engineering as an effective therapy in a variety of diseases.
Cryopreservation of Cultured Blood Cells for Use in Gene Therapy and Immunotherapy
Authors: Hubel Allison , McCullough Jeffrey 
Published: September 2024

Abstract
The freezing characteristics of genetically manipulated lymphocytes and hematopoietic stem cells were studied. The water transport characteristics of stem cells which had been cultured and transduced with a therapeutic gene were different from that of a freshly isolated cells. Changes in the freezing characteristics for genetically transformed lymphocytes were also observed. Specifically, cryopreservation protocols developed for the fresh peripheral blood lymphocytes do not produce comparable survival rates for lymphocytes which have been cultured and transduced. These results indicate that there are significant changes in the freezing characteristics resulting from the culture and transduction process.
Biothermal Engineering: Present Status, Future Directions
Authors: Chato John C. 
Published: September 2024

Abstract
Biothermal engineering is an interdisciplinary field in which it is extremely important that the researchers in the two major complimentary disciplines, engineering and biology (including medicine), keep in touch with each other. Contact and exchange of ideas within the same discipline is effectively accomplished in conferences and meetings of the various professional societies. Reaching across disciplines, however, is a much more difficult task and requires special effort. Although many research groups have established fruitful cooperative efforts among the various disciplines for the performance of specific tasks, it is of great importance and benefit to bring together a larger group of workers from engineering, biology, and medicine to examine a field from an overall viewpoint and to identify promising new avenues for future work.
Modeling of Human Thermal Regulation for Liquid Cooling Garment Applications
Authors: Nyberg Karen L. , Diller Kenneth R. , Wissler Eugene H. 
Published: September 2024

Abstract
The Wissler Human Thermoregulation Model has been adapted for use in the design of control schemes for regulating liquid cooling garment (LCG) inlet coolant temperature. The model was used to simulate various activity scenarios in a space suit while both liquid coolant and ventilation gas were in thermal communication with the human subject. Model parameters were identified which best represent the actual LCG system currently used by NASA. Simulations were performed for the metabolic and thermal activity histories of two different sets of test data available from the Johnson Space Center (JSC). It was demonstrated that the modified Wissler model, incorporating the LCG and ventilation flow effects, simulates actual human thermal and metabolic responses over a broad range of transient work loads and can therefore be reliably applied for design of a future automated thermal control scheme.
A Model of Cryosurgical Destruction in AT-1 Prostate Tumor Based on Cellular Damage Mechanisms
Authors: Smith David J. , Josephson Sean J. , Bischof John C. 
Published: September 2024

Abstract
The thermal history during a prostate cryosurgery is known to lead to different cooling rates, end-temperatures and end-times within a cryosurgical iceball. The tissue exposed to this range of thermal histories will experience thermally-induced biophysical events which affect cell viability (dehydration and intracellular ice formation. IIF), injury due solely to the temperature and time of exposure, and injury due to host response. In this study, the dehydration and IIF behavior of single AT-1 prostate cancer cells is experimentally measured, the biophysical parameters of water transport and IIF are obtained, and the probability of injury to single AT-1 cells due to dehydration (Prd) and IIF (PIF) is predicted for a variety of cryosurgically-relevant thermal histories. In addition, viability data obtained after cooling to different end-temperatures at constant coolins rates is used to create an empirical function of injury for single AT-1 cells based solely on end-temperature (Pre). A total cellular injury model which then combines the biophysical mechanisms of injury as well as the empirically-obtained temperature viability function is created. This model is used to predict worst-case (i.e. highest possible survival) cryosurgical destruction in an AT-1 tumor; the implications for clinical cryosurgery are discussed.
Poloxamer 188 Enhances Functional Recovery of Lethally Heat Shocked Fibroblasts
Authors: Merchant Fatima , Holmes William , Toner Mehmet 
Published: September 2024

Abstract
Surfactant molecules, specifically triblock polymers such as Poloxamer 188 (P-188) have been shown to restore cell membrane integrity. The objective of this study was to develop functional and morphological assays to determine whether treatment with P-188 after heat shock enhances the recovery of lethally damaged cells. Human foreskin fibroblasts (HFF) were heated in suspension and cell recovery after heat shock was assessed using a functional assay based on the contraction of fibroblasts populated collagen lattices (FPCLs). Experiments were performed to evaluate the effect of various concentrations of P-188 on cell recovery after heat shock, and to determine the influence of P-188 on cells subjected to varying degrees of heat stress. Further, the cytoskeletal morphology was determined via confocal microscopy of the fluorescently labeled (Rhodamine Phalloidan) filamentous actin network. Our results indicate that treatment with low concentrations of P-188 after heat shock is effective in ameliorating both the morphological integrity and contractile function of cells for a threshold of thermal stress (45°C for 20–60 minutes). The beneficial influence of P-188 on heat shocked cells coupled with the applicability of FPCL as a reasonable in vitro model for wound healing make these results promising for clinical application.
Theoretical Study of the Temperature Fluctuations Induced During Reflected-Scanned Planar Ultrasound Hyperthermia
Authors: Moros Eduardo G. , Fan Xiaobing , Straube William L. 
Published: September 2024

Abstract
Temperature fluctuations inside of a target volume during scanned planar ultrasound hyperthermia were investigated numerically by varying scan time, blood perfusion, and skin temperature. Three dimensional (3-D), transient, acoustic power deposition patterns induced by a scanning ultrasound reflector linear array system (SURLAS) were simulated and input into an homogeneous, 3-D, transient, bioheat transfer equation model. It was found that the largest temperature fluctuations were located at the ends of the linear scan path where the scanning reflector comes to a sudden stop and reverses direction. The smallest fluctuation was located at the center of the scan window. For a given scan distance, the magnitude of the temperature fluctuations increased linearly with increasing scan time, and increased as a weak exponential function of blood perfusion rate. A scan time of 20 s or less is necessary to keep the temperature fluctuations within ±0.5 °C from the average temperature in a scan cycle for a scan window of 10 × 10 cm and a blood perfusion rate of 5 kg/m3s.
Near Infra Red Spectroscopy of Biological Tissues
Authors: Jones Matthew R. , Yamada Yukio 
Published: September 2024

Abstract
The development of spectroscopic techniques plays a key role in many newly emerging diagnostic and theraputic applications of near infra red (NIR) radiation in medicine. In applications such as photodynamic therapy, optical tomography and laser surgery it is necessary to know the optical properties of various types of biological tissue in order to predict how light will propagate and be distributed throughout the body. The optical parameters of primary interest are the reduced scattering coefficient and the absorption coefficient. In this paper, we discuss the use of the diffusion approximation as a model of the light propagation in biological tissues. We also describe one possible spectroscopic method which uses spatially resolved, transient reflectance measurements to determine the optical properties of biological tissues.
Three-Dimensional Finite Element Analysis of Stress Response in Adhesive Butt Joints Subjected to Impact Bending Moments
Authors: Sawa Toshiyuki , Okuno Hirohisa , Higuchi Izumi , Kato Shinya 
Published: September 2024

Abstract
The stress wave propagation and the stress distribution in adhesive butt joints of T-shape similar adherends subjected to impact bending moments are analyzed using three-dimensional finite-element method (FEM). An impact load is applied to a joint by dropping a weight. FEM code employed is DYNA3D. The effects of Young’s modulus of adherends, the adhesive thickness and the web length of T-shape adherends on the stress wave propagation at the interfaces are examined. It is found that the maximum stress occurs at the interfaces. In the case of T-shape adherends, it is seen that the maximum principal stress at the interfaces increases as Young’s modulus of the adherends increases. In the special case where the web length of T-shape adherends equals to the flange length, the maximum principal stress at the interfaces increases as Young’s modulus of the adherends decreases. The maximum principal stress at the interfaces increases as the adherend thickness decreases. In addition, strain response of adhesive butt joints was measured using strain gauges. Fairly good agreement is seen between the analytical and the experimental results.
Stress Analysis and Strength of Adhesive Lap Joints of Dissimilar Hollow Shafts Subjected to Axial Load
Authors: Nakano Yuichi , Kawawaki Masataka , Sawa Toshiyuki 
Published: September 2024

Abstract
The stress and strain distributions in adhesive lap joints of dissimilar hollow shafts subjected to an axial load are examined using an axisymmetric theory of elasticity. The effects of the ratio of Young’s modulus of the adhesive to that of the shaft and of the thickness of the adhesive on the stress distributions at the interfaces in the joint are clarified numerically. It is seen that the stresses in radial and circumferential directions become singular at the ends of the interfaces and the stress increases near the ends of the interface with a decrease of Young’s modulus of the shaft and with an increase of the thickness of the adhesive. For verification of the stress analysis, the strain distribution at an outer surface of the adhesive lap joint was measured and a fairly good agreement was shown by comparing the experimental results with the analytical predictions. Moreover, the tensile strength of adhesive lap joints was measured and evaluated by stress analysis.
Rotating-Loosening-Free Conditions of Joint Structure That Fastens Drive-Shaft and Hub in Automobile Axle
Authors: Sakai Tomotsugu 
Published: September 2024

Abstract
In many automobiles, to prevent the nut loosening, the fastening structure of drive-shaft and hub in their axles has the lock-nut and the shaft with lead angled spline teeth to get the tight pressed-in fit, or very precisely machined/rolled spline teeth to eliminate the circumferential clearance. But, in these structures, the production process both of machining/rolling spline and of assembling the shaft and the hub becomes more complicated. So, more attention must be paid to the production process. As a result, the production cost and time can not help being higher and longer. Therefore, the author analyzed the necessary conditions that prevent the rotating loosening of the nut even without the above-mentioned spline, and got five independent necessary conditions that consist of the joint specifications.
➀ TF &gt; TE, TE: the drive line transmitted torque, TF: the friction torque between the shaft and the hub. ➁ θcr &gt; θ, θ: the relative rotating angle between the shaft and the hub under the torque TE, θcr: the “rotating-loosening-free critical angle” of the fastening axis. ➂ | deμs / dw cos α − μw | &gt; P / π dw, de: effective diameter of thread, dw: equivalent diameter of bearing surface, α: half angle of thread, P: pitch of thread, μs: friction coefficient of thread surface, μw: friction coefficient of bearing surface. ➃ TsLOCK &gt; Tw − TsL, TsLOCK: thread surface locking torque. ➄ TwLOCK &gt; TsT − Tw, TwLOCK: bearing surface locking torque. Here, Tw: friction torque on bearing surface, TsL: releasing torque on thread surface, TsT: tightening torque on thread surface.
If at least one of these five conditions is satisfied, the screw thread can not loosen by rotating.
On the Reliability Analysis of VLSI Chips When Subjected to Thermal Cycling
Authors: Jahanian Shahriar , Goshtasbi-G Jamshid 
Published: September 2024

Abstract
Elevated temperature has been considered as a dominant factor of stress which lowers the reliability and life expectancy of the microelectronics devices. Arrhenius model is commonly used for predicting the reliability and failure rate of the microelectronics devices as a function of ambient temperature. Arrhenuis model extrapolates life data, obtained from units tested at constant elevated temperatures, to the working temperatures. Generally, the temperature of microelectronics devices are lowered using an appropriate cooling method to achieve a desired reliability and life expectancy. However, during the cooling process the chips are subjected to transient temperature change that enhances the chance of fracture and eventually failure of chips.
Cyclic thermal stresses are the common cause of the fracture of mechanical structures. Accordingly, when cooling microelectronics devices, the following questions are raised;
• Considering the possibility of the fracture of microelectronics devices when subjected to cyclic thermal loading, how does this effect in life expectancy and reliability of chips (by lowering the temperature) as predicted by Arrhenius model.
• Considering the cost of lowering the temperature of these devices, could there be an optimal temperature yielding an acceptable reliability and life expectancy with lower cooling cost?
This problem in particular becomes more critical in case of (Very Large Scale - Integration) VLSI chips, where highly dense circuits occupy almost all area of the die. Hence the probability of failure due to fracture in VLSI chips is highly expected. For this case a different model than Arhenuis model is needed to correctly predict the reliability and life expectancy of VLSI chips when subjected to thermal cycling. This paper presents a methodology for developing such a model that include the possibility of the fracture of VLSI chips subjected to cyclic thermal loading.