Study of tissue temperature distribution during laser-immunotherapy for cancer treatment

Scope and Method of Study: The ideal cancer treatment modality should not only cause primary tumor suppression but also induce an anti-tumor immunity, which is essential in controlling metastatic tumors. Motivation of this work is to monitor temperature during laser-cancer treatment. A Monte Carlo method for the light transport in tissue and a finite difference method for the solution of heat diffusion equation were performed to estimate the laser dose parameters, and concentration levels of dye and immunoadjuvant. The specimens used were gelatin phantom, rats and mice. Magnetic Resonance Imaging thermometry (MRT) and infrared thermography (IRT) have been used for the measurement of temperature in the biological tissues during treatment of the primary tumors. Thermal imaging is used to estimate the laser-dose in application to cancer treatment. The thermal imaging and dose calculation can increase the level of safety in the treatment by providing information on target tissue and also on surrounding normal tissue.Findings and Conclusions: Magnetic Resonance Imaging (MRI) has been applied to measure the thermal distribution in gel phantom and tumor-bearing rats during laser treatment. Infrared thermography has been applied to measure the surface temperature under the same conditions in tumor-bearing mice. Intratumoral injection of both indocyanine green (ICG) and glycated chitosan (GC) followed by 805-nm laser irradiation has been found efficacious in the cancer treatment. The temperature rise with ICG and laser combination therapy was about 25 °C and with the ICG, GC, and laser combination therapy, the temperature increased by 30 °C. This infers that ICG and GC injection potentiates the laser-immunotherapy. In both the cases, the tumor temperature attains the cancer cell damage temperature range of 60 °C - 70 °C resulting in an increase in the survival time of the treated mice. More importantly, the temperature profiles in this study agree with the Monte Carlo simulation results. In summary, a combination therapy using a laser, a laser-absorbing dye, and an immunoadjuvant guided by temperature measurement probes, such as MRT and IRT, is an effective treatment modality

From Early Curiosity to Space Wide Web: Emergence of the Small Satellite Innovation Ecosystem

Research Questions: How did the small satellite ecosystem emerge and evolve? Although the first modern small satellite UoSat-1 was successfully launched in 1981, and the CubeSat dominant design was introduced in 1999, the sales takeoff of small satellites did not occur until the early 2010s. What explains this long time period

Walking the Tightrope: Coopetition Capability Construct and Its Role in Value Creation

Prior research emphasizes the paradoxical nature of coopetition and the need for specialized capabilities—coopetition capability—to deal effectively with opportunities and challenges stemming from the simultaneous pursuit of cooperation and competition and to create superior value. However, we know little about the underlying conceptual properties of coopetition capability (construct clarity) and lack a reliable and valid scale to measure it (construct validity). We conduct a study in three phases to address this critical gap. First, building on paradox literature, we conceptualize coopetition capability as a multidimensional construct reflected by three underlying dimensions: coopetition mindset, analytical acumen, and executional skills. Second, we develop a 15-item psychometrically valid scale using a sample of 647 coopetitive alliances in high-technology sectors. Finally, using a matched sample of 536 coopetitive alliances, we extend the focal construct's nomological network by examining two relationships: coopetition experience's impact on coopetition capability and the effect of coopetition capability on the relationship between the coopetition paradox and value creation. Overall, our paper lays a foundation for deeper theory development and empirical research on coopetition by providing much-needed construct clarity and psychometrically valid measures for coopetition capability

Photoperiodic Regulation of Cerebral Blood Flow in White-Footed Mice (Peromyscus leucopus)

Individuals living outside the tropics need to adjust their behavioral and physiological repertoires throughout the year to adapt to the changing seasons. White-footed mice (Peromyscus leucopus) reduce hippocampal volumes, hippocampal-dependent memory function, long-term potentiation, and alter neurogenesis in response to short (winter-like) day lengths (photoperiods). During winter, these mice putatively shunt energy away from the brain to maximize peripheral thermogenesis, immune function, and survival. We hypothesized that these changes in brain function are accompanied by alterations in brain vasculature. We maintained white-footed mice in short (8 h light/16 h dark) or long (16 h light/8 h dark) photoperiods for 8-9 weeks. Mice were then perfused with fluorescein isothiocyanate (FITC)-conjugated tomato (Lycopersicon esculentum) lectin to visualize the perfused cerebrovasculature. Short-day mice reduced hippocampal and cortical capillary density (FITC(+) area); vessels isolated from short day-exposed mice expressed higher mRNA levels of the gelatinase matrix metalloproteinase 2 (MMP2). Additionally, short-day mice reduced cerebral blood flow approximately 15% compared with their long-day counterparts, as assessed by laser speckle flowmetry. Immunohistochemistry revealed higher levels of MMP2 in the hippocampus of mice maintained in short days compared with long days, potentially contributing to the observed vascular remodeling. These data demonstrate that a discrete environmental signal (i.e., day length) can substantially alter cerebral blood flow in adult mammals

Temperature distribution in selective laser-tissue interaction

Selective photothermal interaction using dye enhancement has proven to be effective in minimizing surrounding tissue damage and delivering energy to target tissue. During laser irradiation, the process of photon absorption and thermal energy diffusion in the target tissue and its surrounding tissue are crucial. Such information allows the selection of proper operating parameters such as dye concentrations, laser power, and exposure time for optimal therapeutic effect. Combining the Monte Carlo method for energy absorption and the finite difference method for heat diffusion, the temperature distributions in target tissue and surrounding tissue in dye enhanced laser photothermal interaction are obtained. Different tissue configurations and dye enhancement are used in the simulation, and different incident beam sizes are also used to determine optimum beam sizes for various tissue configurations. Our results show that the algorithm developed in this study could predict the thermal outcome of laser irradiation. Our simulation indicates that with appropriate absorption enhancement of the target tissue, the temperature in the target tissue and in the surrounding tissue can be effectively controlled. This method can be used for optimization of lesion treatment using laser photothermal interactions. It may also provide guidance for laser immunotherapy in cancer treatment, since the immunological responses are believed to be related to tissue temperature changes

The nature, consequences, and management of emotions in interfirm paradoxical relationships - a conceptual framework

We develop a theory of emotions in interfirm paradoxical relationships with a focus on coopetition and emotional ambivalence. We suggest that appraisals of paradoxical coopetition situations lead to the arousal of multiple, oppositely valenced emotions of various intensities, combinations of which correspond to different states of emotional ambivalence. We explicate how emotional ambivalence, through managers’ appraisal and emotional contagion processes becomes collective and how it impacts coopetition performance. We further theorize how the negative effect of ambivalence on performance could be minimized and the positive effect could be amplified through emotional capability. Our theory provides a nuanced understanding of the complex nature of emotions, and how they arise, manifest, and impact outcomes in interfirm paradoxical relationships

Effect on Texas Grapefruit Sales…Point-of-Purchase Display Material.

2 p

The interplay of competition and cooperation

Research streams on competition and cooperation are central to the field of strategic management but have evolved independently. The emerging literature on coopetition has brought attention to the phenomenon of simultaneous competition and cooperation, yet the interplay between the two has remained under-researched. We offer a roadmap for studying this interplay, which identifies some of its antecedents and consequences, highlights debates concerning the nature of competition and cooperation and the association between the two, and directs attention to the tension between competition and cooperation and the alternative approaches for managing this tension. We discuss the broader implications of the interplay, note some intriguing open questions, offer directions for future research, and present an organizing framework for the interplay of competition and cooperation

An identity perspective on coopetition in the craft beer industry

Research Summary: To further our understanding of how and why organizations engage in coopetition, we explore cooperative and competitive actions in the craft beer industry. Through an inductive field study, including interviews with craft brewery owners, we propose collective identity and collective norms play a critical role in the persistence of coopetition over time. Our process model suggests that (a) an oppositional collective identity, (b) the shared belief that a rising tide lifts all boats, and (c) the shared belief that advice and assistance should be paid forward, can lead to the persistence of coopetition beyond market category emergence. Managerial Summary: This paper develops a theory of how smaller, craft-based organizations (i.e., “Davids”) encourage cohesion and cooperation amongst themselves when operating against an incumbent market of mass-producers (i.e., “Goliaths”). An ideological opposition to existing players can lead to a shared belief that helping organizations like your own benefits everyone—the rising tide lifts all boats mentality. Similarly, when organizations first enter a market and receive help from established members, they can feel compelled to help others who enter the market after—the pay-it-forward mentality. Together, these mechanisms offer an explanation as to how and why coopetition might persist in a market category over time