Simultaneous pectoralis major-latissimus dorsi myocutaneous flap: An option of reconstruction for open sternal wounds

SummaryManagement of the open sternal wound after surgery is a challenge. We report a retrospective series of cases with regard to the management of sternal wounds according to our own experience and a review of the related literature. A retrospective chart review from June 2007 to February 2010 of patients with infective and open sternal wounds after surgery was performed. There were seven patients with a previous history of type A aortic dissection treated with the Bentall operation, thymoma with excision, mitral and tricuspid regurgitation with double valve replacement, and acute myocardial infarction with a ventricular-assist device or coronary artery bypass graft. All wound cultures of the seven patients showed positive findings. All patients received the latissimus dorsi (LD) myocutaneous flap for lower sternal wound reconstruction under the decubitus position and a contralateral pedicled rotated pectoralis major (PM) myocutaneous flap for the upper sternal wound. The residual wound was covered with a split-thickness skin graft. The mean age of the seven patients, including four males and three females, was 58.1 years (range: 33–73 years). The mean follow-up was 37.7 months (range: 30–44 months). The average time span between the final débridement and the flap reconstruction procedure was 5.2 ± 1.8 days. The harvested area of LD myocutaneous flap ranged from 25 × 10 cm2 to 15 × 8 cm2, and the area of PM myocutaneous flap ranged from 15×15 cm2 to 10 × 5 cm2. Four of seven patients had an omental flap initially, but salvage surgery was performed using a simultaneous pectoralis major-LD flap. Three cases underwent simultaneous PM-LD flap directly. One patient expired on postoperative Day 4 because of sudden ventricular fibrillation, but no postoperative complications were noted in the other six patients. With long-term follow-up, all patients survived without significant complications. The simultaneous PM-LD myocutaneous flap is a reliable option for open sternal wound reconstruction

Remaining As A Leader or Not? Technology Spillover Answers

Much has been discussed about the advantages and disadvantages of being a first mover. However, discussion regarding the incentives encouraging a firm to remain as leader is absent in most studies. This paper aims to fill this gap and provide theoretical and empirical evidences vis-à-vis the incentives of remaining as a leader, by comparing profits between leader and follower when taking technology spillover and technological efficiency into consideration. The findings show that in regard to effective technological efficiency: (i) under the condition of a weak (strong) technology spillover, retaining the position of leader firm is (not) a dominant strategy because of higher (lower) profits than a follower; (ii) the half-shared technology spillover leads to an equal profit between firms, and implies a critical time of action for the leader firm to break the evenly-matched status by reconsidering first mover advantages; (iii) an empirical study on a data set of 352 high-tech and non-high-tech SMEs in manufacturing industry from 1999 until 2006 lends strong support to these results and may also provide useful clues for technology managers or practitioners to make better policies to benefit their market competitiveness

Theoretical and bifurcation analysis of a flexible rotor supported by gas-lubricated bearing system with porous bushing

The bifurcation behaviors of a flexible rotor supported by gas-lubricated bearing system with porous bushing are analyzed by a novel numerical method combining the finite difference method and differential transformation method. The results obtained by proposed method are verified with traditional finite difference method, and the analytical results by these two methods are consistent and also in good agreement. Furthermore, the dynamic orbits, power spectra, bifurcation diagram, Poincaré maps and maximum Lyapunov exponent are used to confirm the changes of rotor behavior as the rotor mass is increased. The results show that the rotor center reveals complex dynamic behaviors including periodic, sub-harmonic and chaotic motions. Especially, the rotor bearing system behaves chaos over the ranges of rotor mass 10.7 ≤ms< 13.8 kg. The current results provide an effective means of the gas bearing systems and further understanding of the nonlinear dynamic behavior of bearing systems characterized by different rotor masses

Factors Affecting Daughter Cells' Arrangement during the Early Bacterial Divisions

On agar plates, daughter cells of Escherichia coli mutually slide and align side-by-side in parallel during the first round of binary fission. This phenomenon has been previously attributed to an elastic material that restricts apparently separated bacteria from being in string. We hypothesize that the interaction between bacteria and the underneath substratum may affect the arrangement of the daughter bacteria. To test this hypothesis, bacterial division on hyaluronic acid (HA) gel, as an alternative substratum, was examined. Consistent with our proposition, the HA gel differs from agar by suppressing the typical side-by-side alignments to a rare population. Examination of bacterial surface molecules that may contribute to the daughter cells' arrangement yielded an observation that, with disrupted lpp, the E. coli daughter cells increasingly formed non-typical patterns, i.e. neither sliding side-by-side in parallel nor forming elongated strings. Therefore, our results suggest strongly that the early cell patterning is affected by multiple interaction factors. With oscillatory optical tweezers, we further demonstrated that the interaction force decreased in bacteria without Lpp, a result substantiating our notion that the side-by-side sliding phenomenon directly reflects the strength of in-situ interaction between bacteria and substratum

Giant lipoma arising from deep lobe of the parotid gland

BACKGROUND: Lipomas are common benign soft tissue neoplasms but they are found very rarely in the deep lobe of parotid gland. Surgical intervention in these tumors is challenging because of the proximity of the facial nerve, and thus knowledge of the anatomy and meticulous surgical technique are essential. CASE PRESENTATION: A 71-year-old female presented with a large asymptomatic mass, which had occupied the left facial area for over the past fifteen years, and she requested surgical excision for a cosmetically better facial appearance. The computed tomography (CT) scan showed a well-defined giant lipoma arising from the left deep parotid gland. The lipoma was successfully enucleated after full exposure and mobilization of the overlying facial nerve branches. The surgical specimen measured 9 × 6 cm in size, and histopathology revealed fibrolipoma. The patient experienced an uneventful recovery, with a satisfying facial contour and intact facial nerve function. CONCLUSION: Giant lipomas involving the deep parotid lobe are extremely rare. The high-resolution CT scan provides an accurate and cost-effective preoperative investigative method. Surgical management of deep lobe lipoma should be performed by experienced surgeons due to the need for meticulous dissection of the facial nerve branches. Superficial parotidectomy before deep lobe lipoma removal may be unnecessary in selected cases because preservation of the superficial lobe may contribute to a better aesthetic and functional result

Metrology Camera System of Prime Focus Spectrograph for Subaru Telescope

The Prime Focus Spectrograph (PFS) is a new optical/near-infrared multi-fiber spectrograph designed for the prime focus of the 8.2m Subaru telescope. The metrology camera system of PFS serves as the optical encoder of the COBRA fiber motors for the configuring of fibers. The 380mm diameter aperture metrology camera will locate at the Cassegrain focus of Subaru telescope to cover the whole focal plane with one 50M pixel Canon CMOS sensor. The metrology camera is designed to provide the fiber position information within 5{\mu}m error over the 45cm focal plane. The positions of all fibers can be obtained within 1s after the exposure is finished. This enables the overall fiber configuration to be less than 2 minutes.Comment: 10 pages, 12 figures, SPIE Astronomical Telescopes and Instrumentation 201

Improving thermal stability and efficacy of BCNU in treating glioma cells using PAA-functionalized graphene oxide

Yu-Jen Lu1,2,#, Hung-Wei Yang1,#, Sheng-Che Hung3, Chiung-Yin Huang2, Shin-Ming Li4, Chen-Chi M Ma4, Pin-Yuan Chen2, Hong-Chieh Tsai2, Kuo-Chen Wei2, Jyh-Ping Chen1 1Department of Chemical and Materials Engineering, Chang Gung University, Kwei-San, Taoyuan, Taiwan; 2Department of Neurosurgery, Chang Gung Memorial Hospital, Kwei-San, Taoyuan, Taiwan; 3Department of Radiology, Taipei Veterans General Hospital, Taipei, Taiwan; 4Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan#These authors contributed equally to this workBackground: 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), a commercial chemotherapeutic drug for treating malignant brain tumors, has poor thermal stability and a short half-life. Immobilization of BCNU on a nanocarrier might increase the thermal stability of BCNU and extend its half-life.Methods: Nanosized graphene oxide (GO) could be modified by polyacrylic acid (PAA) to improve the aqueous solubility and increase the cell penetration efficacy of the nanocarrier. PAA&amp;ndash;GO intended as a drug carrier for BCNU was prepared and characterized in this study. The size and thickness of PAA&amp;ndash;GO was investigated by transmission electron microscopy and atomic force microscopy, and the presence of PAA functional groups was confirmed by electron spectroscopy for chemical analysis and thermogravimetric analysis. BCNU was conjugated to PAA&amp;ndash;GO by covalent binding for specific killing of cancer cells, which could also enhance the thermal stability of the drug.Results: Single layer PAA&amp;ndash;GO (about 1.9 nm) with a lateral width as small as 36 nm was successfully prepared. The optimum drug immobilization condition was by reacting 0.5 mg PAA&amp;ndash;GO with 0.4 mg BCNU, and the drug-loading capacity and residual drug activity were 198 &amp;micro;g BCNU/mg PAA&amp;ndash;GO and 70%, respectively. This nanocarrier significantly prolonged the half-life of bound BCNU from 19 to 43 hours compared with free drug and showed efficient intracellular uptake by GL261 cancer cells. The in vitro anticancer efficacy of PAA&amp;ndash;GO&amp;ndash;BCNU was demonstrated by a 30% increase in DNA interstrand cross-linking and a 77% decrease in the IC50 value toward GL261 compared with the same dosage of free drug.Conclusion: Nanosized PAA&amp;ndash;GO serves as an efficient BCNU nanocarrier by covalent binding. This nanocarrier will be a promising new vehicle for an advanced drug delivery system in cancer therapy.Keywords: graphene oxide, BCNU, glioma cells, drug delivery, thermal stabilit

Sensor Fabrication Method for in Situ Temperature and Humidity Monitoring of Light Emitting Diodes

In this work micro temperature and humidity sensors are fabricated to measure the junction temperature and humidity of light emitting diodes (LED). The junction temperature is frequently measured using thermal resistance measurement technology. The weakness of this method is that the timing of data capture is not regulated by any standard. This investigation develops a device that can stably and continually measure temperature and humidity. The device is light-weight and can monitor junction temperature and humidity in real time. Using micro-electro-mechanical systems (MEMS), this study minimizes the size of the micro temperature and humidity sensors, which are constructed on a stainless steel foil substrate (40 μm-thick SS-304). The micro temperature and humidity sensors can be fixed between the LED chip and frame. The sensitivities of the micro temperature and humidity sensors are 0.06 ± 0.005 (Ω/°C) and 0.033 pF/%RH, respectively

YamSat: the First Picosatellite being Developed in Taiwan

This paper describes the current planning and design of the YamSat, the first picosatellite being developed in Taiwan. The design, analysis, manufacture, integration, test and operation of the YamSat will be performed by the National Space Program Office (NSPO), Taiwan, R.O.C, in cooperation with other domestic organizations and companies. It is a member of the CubeSat [1], 10cm x 10cm x 10cm size and within 1kg mass. The major objective of the YamSat is to qualify in space the components and technology developed in Taiwan, including a micro-spectrometer payload using Micro Electro Mechanical Systems (MEMS) technology. The YamSat will be ready for flight in the middle of 2002