We report the first ever terahertz monolithic integrated circuit amplifier based on 25-nm InP high electron mobility transistor (HEMT) process demonstrating amplification at 1 THz (1000 GHz) with ...9-dB measured gain at 1 THz. This milestone was achieved with a 25-nm InP HEMT transistor, which exhibits 3.5-dB maximum available gain at 1 and 1.5 THz projected f MAX .
Transplantation of olfactory ensheathing cells (OECs) is a promising approach for repairing the injured nervous system that has been extensively trialed for nervous system repair. However, the method ...still needs improvement and optimization. One avenue of improving outcomes is to stimulate OEC migration into the injury site. Liraglutide is a glucagon-like peptide-1 receptor agonist used for management of diabetes and obesity. It has been shown to be neuroprotective and to promote cell migration, but whether it can stimulate glial cells remains unknown. In the current study, we investigated the effects of liraglutide on OEC migration and explored the involved mechanisms. We showed that liraglutide at low concentration (100 nM) overall promoted OEC migration over time. Liraglutide modulated the migratory behavior of OECs by reducing time in arrest, and promoted random rather than straight migration. Liraglutide also induced a morphological change of primary OECs towards a bipolar shape consistent with improved migration. We found that liraglutide activated extracellular signal-regulated kinase (ERK), which has key roles in cell migration; the timing of ERK activation correlated with stimulation of migration. Furthermore, liraglutide also modulated the extracellular matrix by upregulating laminin-1 and down-regulating collagen IV. In summary, we found that liraglutide can stimulate OEC migration and re-model the extracellular matrix to better promote cell migration, and possibly also to become more conducive for axonal regeneration. Thus, liraglutide may improve OEC transplantation outcomes.
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•Liraglutide activates extracellular signal-regulated kinase.•Migration of olfactory glia is stimulated by liraglutide.•The extracellular matrix produced by olfactory glia is modulated by liraglutide.•Liraglutide may improve transplantation of olfactory glia for neural repair.
In this paper, background describing THz monolithic integrated circuits using InP HEMT is presented. This three-terminal transistor technology has been used to realize amplifiers, mixers, and ...multipliers operating at 670 GHz. Transistor and processing technology, packaging technology, and circuit results at 670 GHz are described. The paper concludes with initial results from a 670-GHz InP HEMT receiver and trends for InP HEMT components.
Cell transplantation using olfactory ensheathing cells (OECs) is a promising approach for nerve repair but there are numerous limitations with their delivery method. Three-dimensional (3D) cell ...culture systems potentially offer a powerful approach for cell production and delivery options. To further optimise the use of OECs, strategies to promote cell viability and maintain cell behaviours in 3D cultures become important. We previously demonstrated an anti-diabetic drug, liraglutide, could modulate OEC migration and re-model extracellular matrix in two-dimensional (2D) cultures. In the present study, we further investigated its beneficial effects in our 3D culture system using primary OECs. OECs treated with liraglutide at 100 nM showed improved cell viability and had modulated expression of N-cadherin and β1-integrin (two important cell adhesion molecules). When formed into 3D spheroids, the pre-treated OECs generated spheroids with an increased volume and a decreased cell density compared to control spheroids. OECs that subsequently migrated out of the liraglutide pre-treated spheroids had higher capacity for migration with increased duration and length, which was attributed to a reduction in the pauses during the migration. Moreover, OECs that migrated out from liraglutide spheroids had a more bipolar morphology consistent with higher migratory capacity. In summary, liraglutide improved the viability of OECs, modulated cell adhesion molecules, and resulted in stable 3D cell constructs which conferred enhanced migratory capacity on the OECs. Overall, liraglutide may potentially improve the therapeutic use of OECs for neural repair by enhancing the generation of stable 3D constructs and increasing the migratory behaviour of OECs.
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•Liraglutide can improve the viability of olfactory ensheathing cells (OECs).•Liraglutide modulates cell adhesion molecules in both 2D and 3D OEC cultures.•Liraglutide supports stable 3D OEC constructs and enhances cell migratory capacity.•Liraglutide may improve therapeutic benefits and efficacy of OECs for neural repair.
Investors and analysts often need to look into a firm's operations more deeply than traditional financial statements and models allow. This book describes newly developed tools for using operations ...metrics to discern and influence the valuation of a firm. It is the first to present these techniques from a unified perspective: that of operations forensics, which looks at operations management not from the traditional point of view of a manager but from that of an investor or shareholder. After a discussion of financial statements and the useful but incomplete insights they provide, the book covers the three components of operations forensics: operational indicators, operations details that can predict future performance; operational due diligence, methods for verifying companies' claims about operational excellence and valuing their operational assets; and operational turnaround, an innovative approach to buyout and turnaround strategies. The text also offers brief reviews of operations management concepts, real-world examples of operations forensics, and a glossary. The mathematical material gradually increases in sophistication as the book progresses (but can be skipped without loss of continuity). Each chapter concludes with a "Takeaways and Toolkit" section, a brief summary of prior research, and suggestions for further reading. Operations forensics offers powerful tools and frameworks for financial analysts, private equity firms, managers, and consultants. This book provides a valuable resource for MBA students and practitioners. Downloadable supplementary material for instructors incudes figures form the text and 42 slides that can be used for class presentations.
Software requirements are often not set in concrete at the start of a software development project; and requirements changes become necessary and sometimes inevitable due to changes in customer ...requirements and changes in business rules and operating environments; hence, requirements development, which includes requirements changes, is a part of a software process. Previous work has shown that failing to manage software requirements changes well is a main contributor to project failure. Given the importance of the subject, there's a plethora of research work that discuss the management of requirements change in various directions, ways and means. An examination of these works suggests that there's a room for improvement.
In this paper, we present a systematic review of research in Requirements Change Management (RCM) as reported in the literature.
We use a systematic review method to answer four key research questions related to requirements change management. The questions are: (1) What are the causes of requirements changes? (2) What processes are used for requirements change management? (3) What techniques are used for requirements change management? and (4) How do organizations make decisions regarding requirements changes? These questions are aimed at studying the various directions in the field of requirements change management and at providing suggestions for future research work.
The four questions were answered; and the strengths and weaknesses of existing techniques for RCM were identified.
This paper has provided information about the current state-of-the-art techniques and practices for RCM and the research gaps in existing work. Benefits, risks and difficulties associated with RCM are also made available to software practitioners who will be in a position of making better decisions on activities related to RCM. Better decisions will lead to better planning which will increase the chance of project success.
The noise models of InP and GaAs HEMTs are compared with measurements at both 300 and 20 K. The critical parameter, Tdrain, in the Pospieszalski noise model is determined as a function of drain ...current by measurements of the 1-GHz noise of discrete transistors with 50- Ω generator impedance. The dc I-V for the transistors under test are presented and effects of impact-ionization are noted. InP devices with both 100% and 75% indium mole fraction in channel are included. Examples of the design and measurement of very wideband low-noise amplifiers (LNAs) using the tested transistors are presented. At 20-K physical temperature the GaAs LNA achieves 10-K noise over the 0.7-16-GHz range with 16 mW of power and an InP LNA measures 20-K noise over the 6-50-GHz range with 30 mW of power.
Single-cell analysis has been widely applied in various biomedical applications, such as cancer diagnostics, immune status monitoring, and drug screening. To perform an accurate and rapid cellular ...analysis, various magnetic-activated cell sorting techniques are available in the markets. However, large sample requirement and uneven magnetic field distribution limit its application in single-cell trapping and following analysis. To address these problems, we developed a microfluidic microwell device for immunomagnetic single-cell trapping. By adding a microwell layer between the microchannel and magnet, the magnetic field along the device becomes more uniform. Besides, magnetic beads can be retained in the array of microwell after the high-speed washing step, whereas untrapped beads would be flushed away, resulting in high single-particle trapping efficiency (62%) and purity (99.6%). To achieve large-area single-cell trapping, we introduced a “sweeping” loading protocol to further expand the single-particle trapping range. In the microwell region near to the edge of the magnet, over 3000 single magnetic beads were trapped in a 10 mm
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area. Finally, we demonstrated immunomagnetic-labeled THP-1 cells can successfully be trapped at single-cell level in the microwell. The cell trapping process can be done in 10 min. We believe the platform with an accurate and efficient single-cell trapping functionality could potentially be used for various cellular analyses at the single-cell level.
Recently, the microwell has been widely used for cell trapping due to its simple design and enclosed microenvironment for on-chip cell culture and stimulation. In this paper, we investigated the ...effect of various geometrical factors on microwells for efficient particle analysis. We used the Arbitrary Lagrangian–Eulerian method to calculate the trajectory of particles entering circular and triangular microwells under various geometrical factors, particle size, and flow conditions. Our simulation results show that the
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= 2 triangular microwell provides the best trapping efficiency due to a stronger recirculation vortex. A smaller particle size or slower flow rate also enhances particle trapping efficiency. To validate simulation results, we flowed 4.5, 6, and 10 µm diameter polystyrene beads into
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= 1 circular,
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= 1 and
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= 2 triangular microwells under various flow rates. The experimental results agreed well with simulation results, showing that the occupancy of
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= 2 triangular microwell was sevenfold and twofold higher than
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= 1 triangular microwells, respectively. Overall, the above results can provide a useful guideline to design the microwell device for efficient hydrodynamic particle trapping, which can be applied to single cell analysis or rare cell capture.
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