There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Synthesis and surface engineering of iron oxide nanoparticles for biomedical applications

物件導向軟體之架構(Object-Oriented Software Construction)探討

Author(s): Vogel, Alfred; Venugopalan, Vasan | Abstract: The mechanisms of pulsed laser ablation of biological tissues were studied. The transiently empty space created between the fiber tip and the tissue surface improved the optical transmission to the target and thus increased the ablation efficiency. It was found that the structure and morphology also affect the energy transport among tissue constituents.

/pdf/mechanisms-of-pulsed-laser-ablation-of-biological-tissues-58cltfa63z.pdf

Mechanisms of pulsed laser ablation of biological tissues.

The fundamental optical diffraction in infrared microscopes limits their spatial resolution to about ~5μm and hinders the detailed observation of heat generation and dissipation behaviors in micrometer-sized optoelectronic and semiconductor devices, thus impeding the understanding of basic material properties, electrical shorts and structural defects at a micron and sub-micron scale. We report the recent development of a scanning near-field optical microscopy (SNOM) method for thermal imaging with subwavelength spatial resolution. The system implements infrared fiber-optic probes with subwavelength apertures at the apex of a tip for coupling to thermal radiation. Topographic imaging and tip-to-sample distance control are enabled by the implementation of a macroscopic aluminum tuning fork of centimeter size to support IR thermal macro-probes. The SNOM-on-a-fork system is developed as a capability primarily for the thermal profiling of MWIR quantum cascade lasers (QCLs) during pulsed and continuous wave (CW) operation, targeting QCL design optimization. Time-resolved thermal measurements with high spatial resolution will enable better understanding of thermal effects that can have a significant impact on a laser's optical performance and reliability, and furthermore, will serve as a tool to diagnose failure mechanisms.

IR-SNOM on a fork: infrared scanning near-field optical microscopy for thermal profiling of quantum cascade lasers

Background

Bonding of tissues by laser heating is considered as a future alternative to sutures and staples. Increasing the post-operative bond strength remains a challenging issue for laser tissue bonding, especially in organs that have to sustain considerable tension or pressure. In this study, we investigated the influence of different temporal heating profiles on the strength of soldered incisions. The thermal damage following each heating procedure was quantified, in order to assess the effect of each heating profile on the thermal damage.



Materials and Methods

Incisions in porcine bowel tissue strips (1 cm×4 cm) were soldered, using a 44% liquid albumin mixed with indocyanine green and a temperature controlled laser (830 nm) tissue bonding system. Heating was done either with a linear or a step temporal heating profile. The incisions were bonded by soldering at three points, separated by 2 mm. Set-point temperatures of Tset = 60, 70, 80, 90, 100, 110, 150°C and dwell times of td = 10, 20, 30, 40 seconds were investigated. The bond strength was measured immediately following each soldering by applying a gradually increased tension on the tissue edges until the bond break.



Results

Bonds formed by linear heating were stronger than the ones formed by step heating: at Tset = 80°C the bonds were 40% stronger and at Tset = 90°C the bonds strength was nearly doubled. The bond strength difference between the heating methods was larger as Tset increased.



Conclusion

Linear heating produced stronger bonds than step heating. The difference in the bond strength was more pronounced at high set-point temperatures and short dwell times. The bond strength could be increased with either higher set-point temperature or a longer dwell time. Lasers Surg. Med. 42:425-432, 2010. © 2010 Wiley-Liss, Inc.

Temporal heating profile influence on the immediate bond strength following laser tissue soldering.

The design and modeling of strongly pumped, doped silver halide fiber amplifiers are presented. Lasing properties of doped silver halides, in the near or mid-IR region, are studied experimentally and analyzed, based on a rate equation formalism. The analysis is applicable for both three- and four-level systems, such as Er 31 ,P r 31 , and Nd 31 . Optimal amplifier designs are suggested to obtain significant amplifica- tion. © 2001 Society of Photo-Optical Instrumentation Engineers.

Design considerations for rare earth doped silver halide fiber amplifiers

Configurational coordinate diagram of Ni2+ doped silver halide crystals, as determined by optical and luminescence measurements

The presented work describes first principles for monitoring gas hydrate formation and dissociation in solution by evaluating state-responsive IR absorption features of water with fiberoptic evanescent field spectroscopy. In addition, a first order linear functional relationship has been derived according to Lambert Beer’s law, which enables quantification of percentage gas hydrate within the volume of water directly probed via the evanescent field. Moreover, spectroscopic studies evaluating seafloor sediments collected from a gas hydrate site in the Gulf of Mexico revealed minimal spectral interferences from sediment matrix components, thereby establishing evanescent field sensing strategies as a promising perspective for monitoring the dynamics of gas hydrates in oceanic environments.

Abraham Katzir

Papers

IR-SNOM on a fork: infrared scanning near-field optical microscopy for thermal profiling of quantum cascade lasers

Temporal heating profile influence on the immediate bond strength following laser tissue soldering.

Design considerations for rare earth doped silver halide fiber amplifiers

Configurational coordinate diagram of Ni2+ doped silver halide crystals, as determined by optical and luminescence measurements

Infrared Spectroscopy for Monitoring Gas Hydrates in Aqueous Solution