Computed Tomography-Defined Sarcopenia in Outcomes of Patients with Unresectable Hepatocellular Carcinoma Undergoing Radioembolization: Assessment with Total Abdominal, Psoas, and Paraspinal Muscles.

Introduction: Sarcopenia is an adverse prognostic factor in patients with liver cirrhosis and hepatocellular carcinoma (HCC). Image-based sarcopenia assessment allows a standardized method to assess abdominal skeletal muscle. However, which is an index muscle for sarcopenia remains unclear. Therefore, we investigated whether sarcopenia defined according to different muscle groups with computed tomography (CT) scans can predict the prognosis of HCC after radioembolization. Methods: In this retrospective study, we analyzed patients who underwent radioembolization for unresectable HCC between January 2010 and December 2019. Before treatment, the total abdominal muscle (TAM), psoas muscle (PM), and paraspinal muscle (PS) areas were evaluated using a single CT slice at the third lumbar vertebra. In previous studies, sarcopenia was determined using the TAM, PM, and PS after stratifying by sex. Finally, we investigated each muscle-defined sarcopenia to decide whether or not it can serve as a prognostic factor for overall survival (OS). Results: We included 92 patients (74 men and 18 women). TAM, PM, and PS areas were significantly higher in the men than in the women (all p < 0.05). The patients with sarcopenia defined using PM, but not TAM and PS, exhibited significantly poorer OS than those without sarcopenia (median 15.3 vs. 23.8 months, p = 0.034, 0.821, and 0.341, respectively). After adjustment for clinical variables, such as body mass index, liver function, alpha-fetoprotein level, clinical staging, treatment response, and posttreatment curative therapy, PM-defined sarcopenia (hazard ratio: 1.899, 95% confidence interval: 1.087-3.315) remained an independent predictor for the poor OS. Conclusion: CT-assessed sarcopenia defined using PM was an independent prognostic factor for the poorer prognosis of unresectable HCC after radioembolization.

Experimental demonstration of noncontact vital-sign measurement using pulse radar.

BACKGROUD: Recently, monitoring the vital-sign with the noncontact method is a popular technology. OBJECTIVE: In this work, we present a fully pulse radar system including front-end sensing and back-end data processing. A series of ultra-wide band sensing pulses is generated and radiated to detect the subject's chest vibration which in turn obtains the required vital-sign signals. METHODS: An artificial plywood with 3 centimeter thickness is placed between a transmitting/receiving antenna of the radar and subject to demonstrate the characteristic of noncontact sensing. The firmware and digital signal processing are also presented in this paper to optimize physiological data quality. RESULTS: The experimental results show that the continuous heart rate and breathing rate can be monitored by this customized system radar module. CONCLUSION: A fully customized ultra-wide band radar for vital-sign application is presented. The radar system plan with wall parameter is also incorporated into the design consideration to meet the FCC requirement and SNR.

Robust synthetic biology design: stochastic game theory approach.

MOTIVATION: Synthetic biology is to engineer artificial biological systems to investigate natural biological phenomena and for a variety of applications. However, the development of synthetic gene networks is still difficult and most newly created gene networks are non-functioning due to uncertain initial conditions and disturbances of extra-cellular environments on the host cell. At present, how to design a robust synthetic gene network to work properly under these uncertain factors is the most important topic of synthetic biology. RESULTS: A robust regulation design is proposed for a stochastic synthetic gene network to achieve the prescribed steady states under these uncertain factors from the minimax regulation perspective. This minimax regulation design problem can be transformed to an equivalent stochastic game problem. Since it is not easy to solve the robust regulation design problem of synthetic gene networks by non-linear stochastic game method directly, the Takagi-Sugeno (T-S) fuzzy model is proposed to approximate the non-linear synthetic gene network via the linear matrix inequality (LMI) technique through the Robust Control Toolbox in Matlab. Finally, an in silico example is given to illustrate the design procedure and to confirm the efficiency and efficacy of the proposed robust gene design method. AVAILABILITY: http://www.ee.nthu.edu.tw/bschen/SyntheticBioDesign_supplement.pdf.

Electron transport in high-resistance semiconductor nanowires through two-probe measurements.

Since the successful fabrication of semiconductor nanowires, various techniques have been developed to contact these nanowires and to probe their intrinsic electrical properties. Although many novel quasi one-dimensional materials such as Pb(1 - x)Mn(x)Se nanoarrays were recently produced, their intrinsic electron transport properties have not been extensively studied so far. In this work, we demonstrate that an ordinary source-drain configuration of field-effect transistors or the two-probe measurement can be applied to the exploration of the intrinsic properties of nanowires. This two-probe measurement approach also works on highly resistive nanowires without an Ohmic contact issue. By using this method, electron transport behavior, resistivity, and carrier concentrations of ZnO, InP, GaP, and Pb(1 - x)Mn(x)Se semiconductor nanowires have been investigated. Due to the tiny cross-section and few conducting channels, a nanomaterial usually reveals an ultra high resistance. This technique demonstrates a two-probe characterization of nanostructures, paving the simplest way toward electrical characterizations of all high-resistance nanomaterials such as deoxyribonucleic acid (DNA), molecules and organics.

VNTRDB: a bacterial variable number tandem repeat locus database.

Variable number tandem repeat-PCR (VNTR-PCR) is a novel method developed for molecular typing of microorganisms. This method has proven useful in epidemiological studies in medical microbiology. Although hundreds of bacterial genomes have been sequenced, variable number tandem repeats (TRs) derived from comparative genome analyses are scarce. This may hamper their application to the surveillance of bacteria in molecular epidemiology. Here, we present a freely accessible variable number tandem repeat database (VNTRDB) that is intended to be a resource for helping in the discovery of putatively polymorphic tandem repeat loci and to aid with assay design by providing the flanking sequences that can be used in subsequent PCR primer design. In order to reveal possible polymorphism, each TR locus was obtained by comparing the sequences between different sets of bacterial genera, species or strains. Through this comparison, TRs which are unique to a genus can also be identified. Moreover, a visualization tool is provided to ensure that the copy number and locus length of repeats are correct. The VNTRDB is available at http://vntr.csie.ntu.edu.tw/.

Reliability of a new ultrasonic cardiac output monitor in recipients of living donor liver transplantation.

The ultrasonic cardiac output monitor (USCOM) is a new Doppler device for noninvasive hemodynamic monitoring. The aim of this prospective nonrandomized study was to test the feasibility, perioperative reliability, and clinical applicability of using USCOM as an alternative to pulmonary artery catheterization in recipients of living donor liver transplantation. Thirteen patients scheduled to receive living donor liver transplants were initially recruited. Three were subsequently excluded prior to the commencement of surgery because of technical difficulties in obtaining diagnostic-quality images with USCOM. Ten patients proceeded to be studied. Cardiac output measurements by thermodilution and USCOM were compared at 30-minute intervals throughout the procedure and at 10 specific procedural reference points during the surgery when hemodynamic changes were most likely to be observed. The data were analyzed with Lin's concordance coefficient and Bland-Altman analysis. Two hundred ninety paired cardiac output values were obtained from the 10 patients. The concordance between both methods was excellent in 8 patients and satisfactory in 2. Bland-Altman analysis of all data produced a mean bias of - 0.02 L/minute for USCOM, and the 95% limits of agreement were -1.06 to +1.10 L/minute. Further analysis of the 10 reference time points showed minimal bias and high levels of agreement between the methods. We conclude that USCOM provides an accurate and noninvasive method for cardiac output measurement during liver transplantation. It may therefore represent an alternative to pulmonary artery catheter placement with consequent reduction in patient's risk and morbidity associated with catheterization. Liver Transpl 14:1029-1037, 2008. (c) 2008 AASLD.

Robust model matching control of immune systems under environmental disturbances: dynamic game approach.

A robust model matching control of immune response is proposed for therapeutic enhancement to match a prescribed immune response under uncertain initial states and environmental disturbances, including continuous intrusion of exogenous pathogens. The worst-case effect of all possible environmental disturbances and uncertain initial states on the matching for a desired immune response is minimized for the enhanced immune system, i.e. a robust control is designed to track a prescribed immune model response from the minimax matching perspective. This minimax matching problem could herein be transformed to an equivalent dynamic game problem. The exogenous pathogens and environmental disturbances are considered as a player to maximize (worsen) the matching error when the therapeutic control agents are considered as another player to minimize the matching error. Since the innate immune system is highly nonlinear, it is not easy to solve the robust model matching control problem by the nonlinear dynamic game method directly. A fuzzy model is proposed to interpolate several linearized immune systems at different operating points to approximate the innate immune system via smooth fuzzy membership functions. With the help of fuzzy approximation method, the minimax matching control problem of immune systems could be easily solved by the proposed fuzzy dynamic game method via the linear matrix inequality (LMI) technique with the help of Robust Control Toolbox in Matlab. Finally, in silico examples are given to illustrate the design procedure and to confirm the efficiency and efficacy of the proposed method.

RNA-Seq SSRs of Moth Orchid and Screening for Molecular Markers across Genus Phalaenopsis (Orchidaceae).

BACKGROUND: The moth orchid (Phalaenopsis species) is an ornamental crop that is highly commercialized worldwide. Over 30,000 cultivars of moth orchids have been registered at the Royal Horticultural Society (RHS). These cultivars were obtained by artificial pollination of interspecific hybridization. Therefore, the identification of different cultivars is highly important in the worldwide market. METHODS/RESULTS: We used Illumina sequencing technology to analyze an important species for breeding, Phalaenopsis aphrodite subsp. formosana and develop the expressed sequence tag (EST)-simple sequence repeat (SSR) markers. After de novo assembly, the obtained sequence covered 29.1 Mb, approximately 2.2% of the P. aphrodite subsp. formosana genome (1,300 Mb), and a total of 1,439 EST-SSR loci were detected. SSR occurs in the exon region, including the 5' untranslated region (UTR), coding region (CDS), and 3'UTR, on average every 20.22 kb. The di- and tri-nucleotide motifs (51.49% and 35.23%, respectively) were the two most frequent motifs in the P. aphrodite subsp. formosana. To validate the developed EST-SSR loci and to evaluate the transferability to the genus Phalaenopsis, thirty tri-nucleotide motifs of the EST-SSR loci were randomly selected to design EST-SSR primers and to evaluate the polymorphism and transferability across 22 native Phalaenopsis species that are usually used as parents for moth orchid breeding. Of the 30 EST-SSR loci, ten polymorphic and transferable SSR loci across the 22 native taxa can be obtained. The validated EST-SSR markers were further proven to discriminate 12 closely related Phalaenopsis cultivars. The results show that it is not difficult to obtain universal SSR markers by transcriptome deep sequencing in Phalaenopsis species. CONCLUSIONS: This study supported that transcriptome analysis based on deep sequencing is a powerful tool to develop SSR loci in non-model species. A large number of EST-SSR loci can be isolated, and about 33.33% EST-SSR loci are universal markers across the Phalaenopsis breeding germplasm after preliminary validation. The potential universal EST-SSR markers are highly valuable for identifying all of Phalaenopsis cultivars.

Nanocontact Disorder in Nanoelectronics for Modulation of Light and Gas Sensitivities.

To fabricate reliable nanoelectronics, whether by top-down or bottom-up processes, it is necessary to study the electrical properties of nanocontacts. The effect of nanocontact disorder on device properties has been discussed but not quantitatively studied. Here, by carefully analyzing the temperature dependence of device electrical characteristics and by inspecting them with a microscope, we investigated the Schottky contact and Mott's variable-range-hopping resistances connected in parallel in the nanocontact. To interpret these parallel resistances, we proposed a model of Ti/TiOx in the interface between the metal electrodes and nanowires. The hopping resistance as well as the nanocontact disorder dominated the total device resistance for high-resistance devices, especially at low temperatures. Furthermore, we introduced nanocontact disorder to modulate the light and gas responsivities of the device; unexpectedly, it multiplied the sensitivities compared with the intrinsic sensitivity of the nanowires. Our results improve the collective understanding of electrical contacts to low-dimensional semiconductor devices and will aid performance optimization in future nanoelectronics.

A Tool Preference Choice Method for RNA Secondary Structure Prediction by SVM with Statistical Tests.

The Prediction of RNA secondary structures has drawn much attention from both biologists and computer scientists. Many useful tools have been developed for this purpose. These tools have their individual strengths and weaknesses. As a result, based on support vector machines (SVM), we propose a tool choice method which integrates three prediction tools: pknotsRG, RNAStructure, and NUPACK. Our method first extracts features from the target RNA sequence, and adopts two information-theoretic feature selection methods for feature ranking. We propose a method to combine feature selection and classifier fusion in an incremental manner. Our test data set contains 720 RNA sequences, where 225 pseudoknotted RNA sequences are obtained from PseudoBase, and 495 nested RNA sequences are obtained from RNA SSTRAND. The method serves as a preprocessing way in analyzing RNA sequences before the RNA secondary structure prediction tools are employed. In addition, the performance of various configurations is subject to statistical tests to examine their significance. The best base-pair accuracy achieved is 75.5%, which is obtained by the proposed incremental method, and is significantly higher than 68.8%, which is associated with the best predictor, pknotsRG.

Robust model matching design methodology for a stochastic synthetic gene network.

Synthetic biology has shown its potential and promising applications in the last decade. However, many synthetic gene networks cannot work properly and maintain their desired behaviors due to intrinsic parameter variations and extrinsic disturbances. In this study, the intrinsic parameter uncertainties and external disturbances are modeled in a non-linear stochastic gene network to mimic the real environment in the host cell. Then a non-linear stochastic robust matching design methodology is introduced to withstand the intrinsic parameter fluctuations and to attenuate the extrinsic disturbances in order to achieve a desired reference matching purpose. To avoid solving the Hamilton-Jacobi inequality (HJI) in the non-linear stochastic robust matching design, global linearization technique is used to simplify the design procedure by solving a set of linear matrix inequalities (LMIs). As a result, the proposed matching design methodology of the robust synthetic gene network can be efficiently designed with the help of LMI toolbox in Matlab. Finally, two in silico design examples of the robust synthetic gene network are given to illustrate the design procedure and to confirm the robust model matching performance to achieve the desired behavior in spite of stochastic parameter fluctuations and environmental disturbances in the host cell.

Increased oxidative stress and gut ischemia caused by prolonged pneumoperitoneum in patients undergoing robot-assisted laparoscopic radical prostatectomy.

OBJECTIVE: To investigate changes in plasma oxidative stress markers associated with prolonged pneumoperitoneum during robot-assisted laparoscopic radical prostatectomy (RALP). METHODS: In all, patients of ASA Physical Status II-III who intended to undergo RALP were enrolled in the study. Arterial plasma levels of malondialdehyde (MDA) and intramucosal pH were measured 1 minute before and at 1 hour, 2 hours, 3 hours, and 4 hours after the introduction of pneumoperitoneum at an insufflation pressure of 15 mmHg; likewise, they were again measured every 10 minutes after deflation for 60 minutes, at 2 hours and 12 hours after deflation. RESULTS: The mean duration of pneumoperitoneum was around 4 hours. After induction of pneumoperitoneum, the MDA concentrations were significantly elevated at various time points as compared with the preinsufflation value. Significant increase of MDA value was noted also 30 minutes after deflation as compared with the pre-deflation levels. The intramucosal pH value decreased significantly after CO(2) insufflation compared with the preinsufflation values. It also increased significantly 2 hours after CO(2) deflation as compared with the pre-deflation values. CONCLUSION: A prolonged pneumoperitoneum in RALP results in decreased splanchnic blood flow. Pneumoperitoneum itself produces oxidative stress, and ischemia-reperfusion model after deflation of pneumoperitoneum produces more oxidative stress.

Protection against large-volume regurgitated fluid aspiration by the ProSeal laryngeal mask airway.

The ProSeal laryngeal mask airway (PLMA) is designed to protect the airway from regurgitated fluid. However, successful channeling of large volumes of regurgitated fluid by PLMA is rarely reported. This case report states that a large volume of regurgitated fluid was successfully channeled by a PLMA. The patient was a healthy 43-year-old male, properly fasted, undergoing transurethral cystolithotomy under general anesthesia with a correctly-placed PLMA. Unexpectedly, a large volume of regurgitated fluid (> 500 mL) spurted out from the PLMA esophageal drainage tube 2 hours after surgery. Careful gastric decompression was performed and airway toilet showed no evidence of aspiration of gastric contents. An endotracheal tube was then placed in lieu of the PLMA for airway maintenance. By the end of surgery, 1300 mL of fluid was drained through the gastric tube. Extubation was smooth and the patient had an uneventful recovery. Further radiological examination revealed the existence of an unrecognized vesicorectal fistula, which allowed the cystoscopic irrigation fluid to escape to the GI tract, resulting in massive gastric regurgitation. The patient underwent fistula repair a week later and was discharged without further difficulty. This is a unique clinical case report to show PLMA can be effective in preventing aspiration when massive passive regurgitation occurs. Strategies in the management of massive regurgitation during PLMA use are discussed.

Myocardial infarction masked by high level spinal anesthesia in a patient undergoing herniorrhaphy.

Myocardial infarction (MI) is one of the leading causes of perioperative morbidity. Although evidence to prove significant reduction of perioperative MI with regional anesthesia is lacking, anesthesiologists still prefer this technique over general anesthesia for surgery involving the lower abdomen or lower extremities, especially in patients with cardiac risks. However, high level of sensory block during spinal anesthesia may obscure the referred pain from MI, which could contribute to the delay of diagnosis and treatment of an acute perioperative attack. We report a case of MI which occurred either intraoperatively or postoperatively, with symptoms that were masked by high level of sensory block to T4 by spinal anesthesia. This perioperative MI was only diagnosed when the patient recovered from anesthesia in the post-anesthesia care unit (PACU).

A study of grid artifacts formation and elimination in computed radiographic images.

Computed radiography (CR) has many advantages such as filmless operations, efficiency, and convenience. Furthermore, it is easier to integrate with the picture archiving and communication systems. Another important advantage is that CR images generally have a wider dynamic range than conventional screen film. Unfortunately, grid artifacts and moiré pattern artifacts may be present in CR images. These artifacts become a more serious problem when viewing CR images on a computer monitor when a clinic grade monitor is not available. Images produced using a grid with higher frequency or a Potter--Bucky grid (i.e., a moving grid, Bucky for short) can reduce occurrence but cannot guarantee elimination of these artifacts [CR & PACS (2000); Detrick F (2001), pp 7-8]. In this paper, the formation of the artifacts is studied. We show that the grid artifacts occur in a narrow band of frequency in the frequency domain. The frequency can be determined, accurately located, and thus removed from the frequency domain. When comparing the results obtained from the proposed method against the results obtained using previous computer methods, we show that our method can achieve better image quality.

Sudden hearing loss after general anesthesia--a case report.

Hearing impairment following many types of neuraxial anesthetic techniques has alreadly been reported previously. However, postoperative sudden hearing loss after general anesthesia (excluding cardiopulmonary bypass cases) for nonotologic surgery is rarely reported. We present a 42-year-old female patient, who underwent ophthalmologic surgery under general anesthesia because of diabetic retinopathy and developed postoperative hearing loss of the left ear. Sensorineural hearing loss was diagnosed and it has persisted without improvement for 2 years following surgery.

The effects of continuous axillary brachial plexus block with ropivacaine infusion on skin temperature and survival of crushed fingers after microsurgical replantation.

BACKGROUND: Continuous axillary brachial plexus block with local anesthetic has been shown to improve tissue perfusion after replantation surgery of the extremity. The present study aimed to investigate whether continuous axillary brachial plexus block with ropivacaine infusion can improve the survival of the reconstructive fingers secondary to an increase in its skin temperature in patients receiving replantation surgery of the crushed fingers. METHODS: Under general anesthesia, 18 patients received replantation or toe-to-hand transplantation of their crushed digits. They were randomly divided into two groups. Under ultrasound guidance, continuous axillary brachial plexus analgesia was effected by a loading dose of 10 ml 0.75% ropivacaine, followed by an infusion of 4-5 ml per hour for up to three days (Group A). Patients who did not receive continuous analgesia postoperatively served as a control (Group B). An infrared thermometer was used to hourly assess the skin temperature of the surgical and non-surgical sites in both groups for 24 h after the surgery. In addition, the survival (the rate of re-operation or amputation) of the reconstructive digits was also evaluated in both groups. RESULTS: The skin temperature of the digits (T1) on both groups did not show any significant difference at any point of time after the surgery albeit there was a trend of increased skin temperature on the reconstructive digits in patients receiving continuous axillary brachial plexus block (Group A) as compared to those without receiving the block (Group B). Also, the difference in skin temperature (dT) differed slightly at 0, 9 and 21 hours postoperatively in Group A in comparison with Group B (0.75 +/- 0.65 vs. -2.33 +/- 1.24, 0.53 +/- 0.34 vs. -3.02 +/- 1.27, -0.125 +/- 0.55 vs. -2.33 +/- 0.91, p < 0.05). However, no patients in both groups received a second operation or amputation of the graft. CONCLUSIONS: The result of this study demonstrated that axillary brachial plexus block with continuous infusion of 0.75% ropivacaine can increase the skin temperature, an index of tissue perfusion, of the reconstructive digits for 24 h after microvascular surgery of the crushed fingers. However, graft survival was good in both groups.

High satisfaction with problem-based learning for anesthesia.

BACKGROUND: The aim of this study was to compare students' satisfaction between problem-based learning (PBL) and lecture-based traditional teaching of anesthesia. METHODS: One hundred and thirty-seven fifth-year medical students were enrolled in a course which used a hybrid curriculum for teaching about anesthesia. The hybrid curriculum included 9 essential lectures and 3 related PBL case discussions. A Linkert 5-point scale was used for to assess students' satisfaction levels between PBL and lecture-based traditional teaching. Data were collected through a year-end questionnaire over 2 academic years from 2002 to 2003. Scores regarding the satisfaction levels between these 2 teaching methods were analyzed using a 2-sided paired t-test. RESULTS: Most students preferred PBL over the lecture-based traditional teaching in the following 6 aspects: learning about anesthesia, understanding other medical knowledge, being interested in and motivated to learn, training for future work, training of personal abilities, and being confident and satisfied with the teaching method (p < 0.05). However, traditional teaching was superior to PBL in enhancing the speed of learning with greater understanding of a basic knowledge of anesthesia, as well as in providing more solid content with understanding of a greater number of anesthetic techniques (p < 0.05). Satisfaction levels with this curriculum did not generally differ between students enrolled in different classes in 2002 and 2003. CONCLUSIONS: Although the assessment tools and content of PBL need to be modified, implementation of PBL for teaching anesthesia showed satisfactory results.

Anesthetic management of Boerhaave's syndrome.

Boerhaave's syndrome or spontaneous esophageal perforation is a life threatening condition which demands early diagnosis and urgent management. Although very selective patients can be treated nonoperatively, in most patients, better overall results can only be attained with early aggressive surgery. Clinical data and accounts of anesthetic management of this condition scarely appear in medical literature. Managing these patients for surgery is among the most challenging tasks facing the anesthesiologist because they may develop septic syndrome with shock. A rapid-sequence induction is mandatory, and the procedures that may aggravate the injury to esophagus should be avoided. Inotropic support and close attention to fluid balance may be required during operation. Because Boerhaave's syndrome is rare, we report here two cases to illustrate possible anesthetic implications of this disease. Both patients underwent thoracotomy to relieve empyema of mediastinum under general anesthesia. The first patient recovered completely after operation due to early diagnosis and treatment, but the second patient developed multiple organ failure and died after operation due to delayed diagnosis of esophageal rupture and severe sepsis. Because survival is directly related to the time to diagnosis and treatment, all clinicians need to be aware of this lethal disease.