利用近红外光谱监测皮肤血氧输运

利用近红外光谱无创监测移植手术的皮瓣成活状况，是近红外组织氧检测技术的最新应用之一，本文介绍子我们设计的利用光纤传导的近外皮肤血氧监测系统。该系统可以灵活调整光谱－探测器间距以适应皮层检测。利用该系统进行的前臂皮皮肤阻断试验中，静脉阻断时皮肤内有显著的血液充盈现现象，全阻断时氧含量明显下降，实验表明，利用近红外光谱法监测瓣血氧输运情况是非常有效的，特别是可以比较好地监测脉回流情况。     

Injectable Polyzwitterionic Lubricant for Complete Prevention of Cardiac Adhesion

After cardiac surgery, tissue damage to the heart may cause adhesion between heart and its surrounding tissues. Post-operative cardiac adhesion may lead to limited normal cardiac function, decreased quality of cardiac surgery, and increased risk of major bleeding during reoperation. Therefore, it is necessary to develop an effective anti-adhesion therapy to overcome cardiac adhesion. An injectable polyzwitterionic lubricant is developed to prevent adhesion between the heart and surrounding tissues and to maintain normal pumping function of the heart. This lubricant is evaluated in a rat heart adhesion model. Poly (2-methacryloyloxyethyl phosphorylcholine) (i.e., PMPC) polymers are successfully prepared via free radical polymerization of monomer MPC, and the optimal lubricating performance, biocompatibility both in vitro and in vivo is demonstrated. Besides, a rat heart adhesion model is conducted to evaluate the bio-functionality of lubricated PMPC. The results prove that PMPC is a promising lubricant for complete adhesion-prevention. The injectable polyzwitterionic lubricant shows excellent lubricating properties and biocompatibility and can effectively prevent cardiac adhesion.     

Femtosecond lasers in biology: nanoscale surgery with ultrafast optics

Femtosecond lasers are emerging as a powerful tool in basic biological research. The high peak light intensity generated by a tightly focused, ultrashort, pulse of infrared laser light enables versatile submicron ablation deep within biological samples. Recent studies have begun to exploit these capabilities to conduct meticulous laser surgery experiments within single cells, as well as within intact organisms. This review will discuss the basic physical mechanisms behind femtosecond laser ablation in biological samples. It will then examine a series of prominent applications in biology and how they are opening new possibilities in a range of research fields. The interface between physics and biology has been exceptionally fruitful over recent years and femtosecond laser ablation is proving to be another prime example of this.     

Existence of herman rings for meromorphic functions

We apply the Shishikura surgery construction to transcendental maps in order to obtain examples of meromorphic functions with Herman rings, in a variety of possible arrangements. We give a sharp bound on the maximum possible number of such rings that a meromorphic function may have, in terms of the number of poles. Finally we discuss the possibility of having “unbounded” Herman rings (i.e., with an essential singularity in the boundary), and give some examples of maps with this property.     

Modeling the heating of biological tissue based on the hyperbolic heat transfer equation

In modern surgery, a multitude of minimally intrusive operational techniques are used which are based on the point heating of target zones of human tissue via laser or radiofrequency currents. Traditionally, these processes are modeled by the bioheat equation introduced by Pennes, who considers Fourier’s theory of heat conduction. We present an alternative and more realistic model established using the hyperbolic equation of heat transfer. To demonstrate some features and advantages of our proposed method, we apply the results obtained to different types of tissue heating with high energy fluxes, in particular radiofrequency heating and pulsed laser treatment of the cornea to correct refractive errors. We hope that the results from our approach will help with refining surgical interventions in this novel field of medical treatment.     

Operations on 3-Dimensional Small Covers

The purpose of this paper is to study relations among equivariant operations on 3-dimensional small covers. The author gets three formulas for these operations. As an application, the Nishimura＇s theorem on the construction of oriented 3-dimensional small covers and the Lu-Yu＇s theorem on the construction of all 3-dimensional small covers are improved. Moreover, for a construction of 3-dimensional 2-torus manifolds, it is shown that all operations can be obtained by using the equivariant surgeries.     

Variation of the Alexander-Conway polynomial under Dehn surgery

Let ε₁ and ε₂ belong to {±1}. When the ε₁-surgery along a knot K₁ in S³ produces the same homology sphere as the ε₂-surgery along a knot K₂ in S³, then the Casson surgery formula implies that ε₁Δ_K1″(1)=ε₂Δ_K2″(1), where Δ(t) denotes the symmetric Alexander polynomial. For any pair (Λ₁(t),Λ₂(t)) of possible knot Alexander polynomials such that ε₁Λ₁″(1)=ε₂Λ₂″(1), we exhibit a pair (K₁,K₂) of knots in S³ such that Δ_K1(t)=Λ₁(t), Δ_K2(t)=Λ₂(t) and the ε₁-surgery along K₁ produces the same homology sphere as the ε₂-surgery along K₂.     

基于NIR-SERS技术结合PCA-LDA统计分析肝癌术后恢复状况

采用近红外表面增强拉曼散射(NIR-SERS)光谱技术,基于高效、稳定、低廉的纳米银膜基底检测了25例肝癌患者、25例肝癌术后患者和25例健康人的氧合血红蛋白(Oxy Hb)。对比发现,健康人、肝癌术后患者和肝癌患者的Oxy Hb的NIR-SERS光谱谱峰强度呈现依次下降的趋势,表明从谱峰强度可以初步判断肝癌术后患者恢复情况。利用主成分分析(PCA)结合线性判别分析(LDA)统计方法进行分析,25个肝癌术后患者中8人判别为健康人,其余17人判别为肝癌患者。判别分组与实际情况相符,表明PCA-LDA统计方法可以更准确地判断肝癌术后患者恢复状况。因此,NIR-SERS技术结合PCA-LDA统计方法有望为肝癌术后患者恢复状况的诊断提供一种新的思路和方法。     

Intraosseous monitoring and guiding by ultrasound: A feasibility study

An efficient method for navigation within bone tissue boundaries is essential for performance of surgical procedures, e.g. without damaging of adjacent vulnerable organs. The application of sonographic measuring methods for this purpose promises to be effective in the ability to distinguish soft trabecular bone from dense cortical bone, owing to an order of magnitude difference in acoustic density between these structures. For this purpose, a specific method was developed that utilizes propagation of a 5 MHz ultrasonic wave through an aqueous milieu. Using this method a 0.2 mm resolution in measurements is achieved. This resolution is in an order of magnitude lower than is required for a clinical use. A three-stage experimental approach was adopted: measurements in a cubic “phantom” made of a transparent plastic material, in samples of fresh porcine femora, and in a clinical setting of drilling in the upper and lower jaw during dental implantation surgery in nine patients. Two patterns of the detected ultrasound wave reflections were found: low amplitude reflections from the aqueous surrounding and trabecular bone and highly reflected ultrasound waves from the cortical bone. We show that trabecular and cortical bones are distinguishable by real-time ultrasonic measurement. The distances of the drilled tracts, in the range of 58.0–122.0 mm for the “phantom” experiment, 22.6–35.5 mm for the ex vivo experiment and 10.0–11.5 mm in the clinical experiment, and residual distances to the opposite edge of the tested samples and organs, in the range of 21.0–82.0 mm for the “phantom” experiment, 3.8–11.36 mm for the ex vivo experiment and 2.1–6.9 mm in the clinical experiment, were measured by the presented sonographic method and compared statistically, using linear correlation and Bland Altman plot, to the mechanical and/or radiographic measurements in all three stages of the experiment. A correlation coefficient above 0.95 was considered an indication of high correlation, while a value of 0.75–0.94 was considered intermediate, and a value below 0.75 was considered poor.     

Long-term preservation of voice improvement following surgical medialization and reinnervation for unilateral vocal fold paralysis

In June of 1996, we reported improved functional voice results when reinnervation was combined with surgical medialization for unilateral vocal fold paralysis. In addition, it was noted that further wasting of the reinnervated vocal fold was prevented in 96% of these patients beyond 2 years' follow-up. The study reported here compares the long-term preservation of voice improvement achieved by surgical medialization alone with that resulting from combined medialization and nerve-muscle pedicle reinnervation. Further significant wasting of the paralyzed vocal fold with voice deterioration from that achieved by surgical medialization alone was noted between 6 months and 2 years postoperatively in 28% of patients, while only 4% of those undergoing combined reinnervation demonstrated this finding at a minimum of 2 years' follow-up.