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Epidermal stem cells play an pivotal role in skin self-renewal, wound repair, and re-epithelialization process. The emergence of new technologies and concepts such as single-cell sequencing and gene knockout further revealed a new mechanism of epidermal stem cells in epidermal self-renewal and wound repair, providing new ideas for wound repair. In this review, the mechanisms of proliferation, differentiation, and migration of epidermal stem cells are discussed. Combined with the analysis of researches on stem cell heterogeneity and cell plasticity, the physiological function of epidermal stem cells can be further understood. The application advances of epidermal stem cells in wound repair is also summarized, which would provide some advice for workers engaged in clinical and basic research on wound repair.表皮干细胞在皮肤自我更新、创面修复、再上皮化过程中发挥关键作用。单细胞测序、基因敲除等新技术新理念的出现进一步揭示了表皮干细胞维持表皮自我更新、参与创面修复的新机制，为创面修复提供了新思路。该文回顾了近年来关于表皮干细胞的增殖、分化、迁移的机制，通过对表皮干细胞异质性与可塑性相关研究的分析，进一步加深对表皮干细胞生理功能的理解；结合表皮干细胞在创面修复领域中的应用进展，为从事创面修复相关工作的临床与基础研究工作者提供参考。.

In this study, an extreme ultraviolet (EUV) conversion efficiency (CE) of 6.9% was obtained in simulation by controlling the delay between a picosecond pre-pulse and a main-pulse with a wavelength of 2 μm; this value is about 7.5% higher than the ns pre-pulse scheme of the EUV emission produced by a 2 μm laser-driven tin-droplet target. In the simulation, the tin droplet expanded into hollow spherical structures after irradiation with a picosecond pre-pulse laser. Notably, compared with a nanosecond pre-pulse, in this case, the density of the tin plasma was lower, and the expansion range was wider for the same delay. Therefore, ps pre-pulse can make the tin plasma reach the optimal state of EUV emission in a shorter delay. In both pre-pulse schemes, the CE value maintains a high value (>5.7%) within a certain delay range (800 ns) between pre-pulse and main-pulse. In this study, the FLASH radiation hydrodynamic code and FLYCHK atomic code were used to investigate the energy conversion and spectra. The results obtained can be potentially useful for EUV lithography under a two-pulse scheme.

Some research vessels set moonpools for sonars installation. The moonpool provides a relatively good working environment for sonar in a harsh marine environment. At the same time, other acoustic detection equipment are installed along the ship bottom behind the moonpool. Due to the exist of the sonar with a variable cross-section, the number of bubbles generated in the moonpool increases. The bubbles generated in the moonpool expel and flow along the vessel bottom to the stern, which leads to the sweepdown effect. The performance of the sonar and other acoustic detection equipment degrades by the bubbles around. However, the research on reducing bubble generation in the moonpool and sweepdown effects is rare. So in present paper the reduction effects of damping devices such as the flange and choke deck on the bubble generation in the moonpool are investigated experimentally. Then, in order to reduce the sweepdown effects of bubbles on the ship bottom, three other damping devices which are double flaps, diversion channel and wedge are investigated. It can be seen that through reducing the area of bubble leakage in the moonpool the distribution position of bubbles can be effectively restricted and the width and thickness of the bubbles reduce.

An all-optical approach to edge-enhanced proton radiography is realized by using a relativistic vortex laser irradiating on nanometer-thick foil. In the proof-of-principle experiments, the hollow proton beam was successfully produced by the transparent target normal electric field sheath in the break-out after-burner acceleration mechanism, using a superintense Laguerre–Gauss laser with the highest intensity of the laser exceeded 1020 W/cm2. An insect was imaged with the proton beam; the leg structures on the edge were clearly captured. By contrast, the dot proton source produced by a Gaussian laser was almost completely blocked by the insect's body, losing most edge information. Hollow-structured proton beams driven by vortex lasers conquer the dot imaging limit for high-energy proton beams, which may benefit imaging of capsule implosions in inertial confined fusion, instability research on expanding plasma, and precise positioning in medical therapy.

A micrometer-scale “plasma lens” self-constructed by the prepulse and main pulse of the Laguerre–Gaussian (LG) laser is realized to enhance the collimation and acceleration of proton beams in a target normal sheath field acceleration mechanism. Hydrodynamic FLASH and particle-in-cell simulations are carried out and find that a collimated proton source with beam divergence ∼2.7° is generated by the LG laser, which is smaller than the case driven by the traditional Gaussian laser. It demonstrates that the curved sheath field on the “plasma lens” plays an important role in the beam collimation. Such an approach considerably relaxes the constraints of complex design for the target fabrication and auxiliary laser pulse, opening new doors for high-repetition-rate collimated proton accelerations for innovative applications in upcoming high-repetition-rate petawatt laser systems.

For some research vessels, a sonar is installed in the moonpool, and some acoustic detection equipment are installed on the ship bottom behind the moonpool, which helps to avoid the impact of the high-speed flow. The moonpool causes the ship bottom discontinued, forming a particular shear layer oscillation. The shear layer oscillation affects the bubble generation and motion in and behind the moonpool. The sonar and acoustic equipment will malfunction when surrounded by many bubbles. However, there is almost no research on the shear layer oscillation near the moonpool. So, in this paper, by measuring the pressure near the moonpool and monitoring the fluid motion in the moonpool and bubbles’ distribution along the ship bottom, the shear layer oscillation near the moonpool is studied experimentally under the action of the incident current and wave. Furthermore, the effects of the sonar and the moonpool shape are investigated. It can be seen that the shear layer oscillation excites the fluid motion in the moonpool. The sonar forms a complicated boundary in the moonpool, resulting in the increase in the frequency of the shear layer oscillation. The shear layer propagates along the ship bottom in the form of the ship bottom wave. Clarifying the oscillating characteristics of the shear layer along the ship bottom with a moonpool is conducive to the design of moonpools in the research ships, and the detection instruments are arranged in the right place along the ship bottom, so as to make sure the detection instruments work properly and detect the marine environment more accurately.

The aim of this study was to investigate whether bone marrow stem cells (MSCs) derived exosomes in rats could promote osteoblast proliferation and improve osteoporosis via inhibiting cell apoptosis.MSCs in rats were isolated and cultured, followed by the identification of surface antigens via flow cytometry. The differentiation of MSCs was detected by alizarin red staining and oil red staining. After extraction from MSCs by ultracentrifugation, the size distribution of exosomes was detected by tunable resistive pulse sensing (TRPS). Specific antigens in MSCs-derived exosomes were determined by flow cytometry. Furthermore, the proliferation and viability of hFOB1.19 cells treated with MSCs-derived exosomes were detected by cell count kit-8 (CCK-8) assay. The effect of MSCs-derived exosomes on cell apoptosis was evaluated by flow cytometry. Protein expression levels of apoptosis-related genes in hFOB1.19 cells were detected by Western blot.MSCs differentiated into osteoblasts and lipoblasts under different treatments. Meanwhile, MSCs-derived exosomes exhibited typical elongated morphology after isolation and culture for 1 and 3 days, respectively. Functionally, MSCs-derived exosomes could promote the viability of hFOB1.19 cells, and significantly increase the expression level of GLUT3. In addition, MSCs-derived exosomes remarkably downregulated apoptosis-related genes and decreased apoptosis in hFOB1.19 cells.MSCs-derived exosomes could promote osteoblast proliferation via inhibiting cell apoptosis, eventually improving osteoporosis.

To investigate the level and influencing factors of health-related quality of life in myasthenia gravis (MG) patients with myasthenia gravis quality of life-15 (MGQOL-15) Chinese version and to provide corresponding measures in one tertiary hospital of Sichuan Province.We collected the general data (gender, age, body mass index BMI, marital status, educational level and employee status), clinical data [Osserman type, myasthenia gravis composite (MGC), other immunopathies, disease duration, frequency of outpatient visits per month, ratio of disease cost to income each month and frequency of symptoms during the past month] and the MGQOL-15 Chinese version from 168 myasthenia gravis patients in one tertiary hospital of Sichuan Province.The mean score of MGQOL-15 was 17.67±12.78. The score of the item "My occupational skills and job status have been negatively affected." was the highest, followed by "I have trouble using my eyes." and "I am frustrated by my MG." Single factor analysis showed that MG patients' QOL were different with different disease severity MGC (F=19.353, P0.001), ratio of disease cost to income each month (F=5.831, P0.001) and the frequency of symptoms during the past month (F=9.128,P0.001). Multiple regression analysis showed that disease severity MGC (β=0.743,P0.001), ration of disease cost to income each month (β=3.347,P0.001) and the frequency of symptoms during the past month (β=2.216,P0.003) were the main predictors of HRQOL in the MG patients.Our study showed that the MGQOL-15 is helpful for clinicians to evaluate MG patients' QOL regularly, investigate the influencing factors and implement corresponding interventions the so as to improve the patients' quality of life. Disease severity MGC, ratio of disease cost to income each month and the frequency of symptoms during the past month were the main predictors of MG patients' QOL. Clinicians should pay more attention to MG patients' disease severity MGC and the frequency of symptoms during the past month.

Background Cytomegalovirus (CMV) disease is a significant complication after liver transplantation. The estimated incidence varies among studies, which have been conducted in single regional centers and with small cohorts. In this study, we investigated the occurrence of CMV disease among liver transplant recipients in a national cohort in Taiwan. Methods This retrospective study used data from the Taiwan National Health Insurance Research Database. All liver transplant recipients in the catastrophic illness database from 2000 to 2009 were enrolled. Cases of CMV disease were identified from the admission database with the use of the ICD-9-CM code 078. Results The national cohort consisted of 1,721 liver transplant recipients (1,200 men and 521 women) with a mean age of 43.9 ± 8.9 years at the time of transplantation. The mean follow-up duration was 3.6 ± 2.7 years. The mortality rate was 14.9% at 1 year and 20.5% at 5 years. During the study period, 84 patients (4.9%) were diagnosed with CMV disease. The overall prevalence of CMV disease was 14.5 per 100 person-years. The cumulative incidences of post-transplantation CMV infection at 3 months, 6 months, 1 year, 2 years, 5 years, and 10 years were 1.2%, 2.7%, 3.8%, 4.2%, 4.8%, and 4.9%, respectively. The most common CMV-related diseases were colitis, hepatitis, and pneumonia. Conclusions The risk of CMV disease was significantly elevated in the first 6 months after liver transplantation in the Taiwanese cohort.

Condensation heat transfer of R134a in a vertical plate heat exchanger was investigated experimentally. The local heat transfer coefficients are determined by means of the measured local wall temperatures. A differential energy balance model is developed for data evaluation. It is found that the correlation proposed by Shah using Ψ and Z factors is suitable for condensation in plate heat exchangers and is adopted to fit the measured data.

The pathogenesis of nonalcoholic fatty liver disease (NAFLD) is still under debate. The aim of this study was to investigate the effects of a long-term fat- and sugar-enriched diet (FSED) and chronic stress (CS) on NAFLD.Male Wistar rats were fed on either a standard diet or a FSED and given CS, a random electric foot shock (2 hr/morning and afternoon per day), or not for 12 weeks. After the experimental period, epididymal adipose tissue weight, sign of visceral obesity (VO), and hepatic index (HI) were measured. At sacrifice blood samples and liver were obtained. Histology of the liver was blindly determined by a pathologist.Histopathologically, moderate to severe steatosis, ballooning hepatocytes, and portal or lobules inflammation were observed in the FSED+CS group. However, mild to moderate steatosis with a few portal inflammation in the FSED group and mild steatosis or not with a few portal inflammation in the CS group were found correspondingly. In addition, more severe blood-fat disorder, high HI, fatty metabolic dysfunction, oxidative stress, high expressions of C-reactive protein mRNA and low expressions of peroxisome proliferator-activated receptor alpha mRNA in the liver were also revealed in the FSED+CS group. But, the degree of VO was not different between the FSED and FSED+CS groups.The observations strongly suggest that chronic stress can aggravate fat- and sugar-enriched diet-induced NAFLD from steatosis to steatohepatitis in male Wistar rats, although VO is not changed.

This paper addresses the identification of linear time-varying multi-degrees-of-freedom systems. The identification approach is based on the Hilbert transform and the empirical mode decomposition method with free vibration response signals. Three-different types of time-varying systems, i.e., smoothly varying, periodically varying, and abruptly varying stiffness and damping of a linear time-varying system, are studied. Numerical simulations demonstrate the effectiveness and accuracy of the proposed method with single- and multi-degrees-of-freedom dynamical systems.

An improved structural damage quantification algorithm is presented based on the elemental modal strain energy change before and after the occurrence of damage in a structure. The algorithm include...

A cyp19a gene that contains nine exons and eight introns was identified from Carassius auratus and was mainly expressed in the ovary. The cyp19a mRNA level after hatching was initially low, but began to increase from 25 days after hatching. A number of cis-acting elements, such as the oestrogen receptor, steroidogenic factor 1 and SOX-5 recognition sites, were found in the promoter of the cyp19 gene, which possesses a promoter function confirmed by a recombination green fluorescent protein checking system in vitro.

Semirigid connections are usually found in large-scale engineering structures, and knowledge concerning the dynamic characteristics of these connections is important to the accurate definition of the dynamic characteristics of the engineering structure. Different models have been presented to define the connection, but most are not suitable for model improvement from dynamic measurements of the structure. This paper presents a hybrid finite-element model consisting of a beam element with 2 semirigid connections at the ends for updating the finite-element model of the jointed structure. The parameter selection strategy of the generic element is adopted, and the stiffnesses of the joint in 3 dimensions are selected as generic parameters to be updated simultaneously with other structural parameters. The proposed method is applied to the model updating of a 3-D steel truss in the laboratory. Results show that the method could significantly improve not only those vibration modes used in the updating, but also the higher modes with a maximum error of 6%.

A structural damage detection method based on modal strain energy (MSE) change before and after damage is presented in this paper. The localization of damage based on MSE of each structural element is briefly presented, and the sensitivity of the MSE with respect to a damage is derived. The sensitivity is not based on any series expansion and is a function of the analytical mode shape changes and the stiffness matrix. Only incomplete measured mode shapes and analytical system matrices are required in this damage localization and quantification approach. Results from a numerical example and an experiment on a single-bay, two-story portal steel frame structure are investigated. The effects of measurement noise and truncated analytical mode shapes are discussed. Results indicate that the proposed approach is noise sensitive, but it can localize single and multiple damages. Damage quantification of two damages is successful with a maximum of 14% error under a 5% measurement noise.

A method of optimizing sensor locations and detecting damage in a structure using the collected information is presented in this paper. Unlike most methods found in the literature, the sensor locations are prioritized according to their ability to localize structural damage based on the eigenvector sensitivity method. This is in line with the requirements for structural damage localization. Only a small subset of the total structural degrees-of-freedom is instrumented, and the incomplete modes yielded from these optimized sensor locations are used to localize structural damage. Numerical example and test results show that this approach is effective for detecting structural damage directly using optimum and incomplete test modes.

A sensitivity- and statistical-based method to localize structural damage by direct use of incomplete mode shapes is presented. The method is an extension of the multiple damage location assurance criterion (MDLAC), developed by Messina et al. by using incomplete mode shape instead of modal frequency. This approach makes use of the good sensitivity of mode shape to local damage. The damage detection strategy is to localize the damage sites first by using incomplete measured mode shapes, and then to detect the damage site and extent again by using measured natural frequencies, which have a better accuracy than mode shapes. A plane truss structure is analyzed as a numerical example to compare the performance of the proposed method with the multiple damage location assurance criterion. Results indicate that the new method is more accurate and robust in damage localization with or without noise effect.

A method based on modal strain energy is presented for locating damage in a structure. This method makes use of the change of modal strain energy in each structural element before and after the occurrence of damage. Some properties of this Modal Strain Energy Change are given to illustrate its sensitivity in locating the structural damage. Information required in the identification are the measured mode shapes and elemental stiffness matrix only without knowledge of the complete stiffness and mass matrices of the structure. Several damage cases in a simulated structure are studied in which the effect of random error in terms of measurement noise in the mode shapes and systematic error in terms of errors from incomplete measurements are considered. This method is then applied to detect damage in a single-bay two-storey portal steel frame structure. Results illustrate that the MSEC is sensitive to damage, and the proposed method is simple and robust in locating single or multiple damages in a structure.

Existing research on structural damage detection usually requires information at every degree of freedom, and this contradicts the usual practice of having a small number of sensors employed over limited locations on the structure. A method to detect the location and to estimate the magnitude of damage in a structure down to the element level with incomplete and noisy measured modal data is proposed. The method consists of three stages: expansion of the measured mode shapes, localization of the damage domain using the elemental energy quotient difference, and damage quantification based on sensitivity of the modal frequency. A new mode shape expansion method is presented, and the effectiveness of the combined use of this method and the elemental energy quotient difference is demonstrated with incomplete measurement. The treatment of modeling errors is discussed. A criterion for selection of the damaged members is proposed and practical means to improve the identification results are presented. Several damage cases of the European Space Agency structure and of a single-bay two-story portal steel frame structure in the laboratory are investigated. The practical problem of having random error and systematic error in the measurement is studied. Results show that the proposed three-stage approach can effectively locate and quantify damages in a real structure.

Both Al interconnects and flip-chip solder bumps were sensitive to high current. The failure mechanism of circuits interconnects would be more complicated if the current density in circuits was exceed the critical magnitudes of electromigration in both Al interconnects and solder bumps. The failure of circuit interconnects under different magnitudes of current density was studied and the interaction of electromigration in solder bumps and Al interconnects was discussed. The circuit interconnects of flip chip show three failure phenomena under high current density: voids in Al final metal, inter-diffusion of Al and SnPb, and melting of solder bumps. The voids in Al metal show the directional diffusion of Al atoms was mainly controlled by the electron wind fore. However the inter-diffusion of Al and SnPb demonstrated the electron wind force to Sn and Pb atoms would be ignored in contrast with chemical potential gradient or intrinsic stress. The flow of Sn and Pb atoms under high current density was in opposite direction with electron wind force and uniform with chemical potential gradient.

This study investigated the in vitro susceptibilities of methicillin-resistant Staphylococcus aureus (MRSA) to nine antimicrobial agents in Taiwan. A total of 1,725 isolates were obtained from 20 hospitals throughout Taiwan from 2006 to 2010. The minimum inhibitory concentrations (MICs) of the nine agents were determined by the agar dilution method. The MICs of mupirocin and tyrothricin were determined for 223 MRSA isolates collected from 2009 to 2010. For vancomycin, 99.7 % were susceptible; however, 30.0 % (n = 517) exhibited MICs of 2 μg/ml and 0.3 % (n = 6) demonstrated intermediate susceptibility (MICs of 4 μg/ml). Nearly all isolates (≥ 99.9 %) were susceptible to teicoplanin, linezolid, and daptomycin. The MIC90 values were 2 μg/ml for ceftobiprole and 1 μg/ml for nemonoxacin. The MIC90 values of mupirocin and tyrothricin were 0.12 and 4 μg/ml, respectively. MIC creep was noted for daptomycin during this period, but not for vancomycin, teicoplanin, linezolid, or tigecycline. For isolates with vancomycin MICs of 2 μg/ml, the MIC90 values were 2 μg/ml for teicoplanin, 0.5 μg/ml for daptomycin, and 0.5 μg/ml for tigecycline. Those values were four- to eight-fold higher than those among isolates with vancomycin MICs of 0.5 μg/ml (2, 0.06, and 0.12 μg/ml, respectively). Of the nine MRSA isolates exhibiting non-susceptibility to vancomycin (n = 6), teicoplanin (n = 1), daptomycin (n = 2), or tigecycline (n = 1), all had different pulsotypes, indicating the absence of intra-hospital or inter-hospital spread. The presence of a high proportion of MRSA isolates with elevated MICs (2 μg/ml) and MIC creep of daptomycin might alert clinicians on the therapy for serious MRSA infections in Taiwan.

In this study, we evaluated three PCR methods for epidemiological typing of Burkholderia (Pseudomonas) cepacia--PCR-ribotyping, arbitrarily primed PCR (AP-PCR) and enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR)--and compared them with pulsed-field gel electrophoresis. The analysis was performed with 31 isolates of B. cepacia, comprising 23 epidemiologically unrelated isolates and 8 isolates collected from the same patient during two episodes of bacteremia. Pulsed-field gel electrophoresis, ERIC-PCR, and AP-PCR identified 23 distinct types among the 23 unrelated isolates, while PCR-ribotyping only identified 12 strain types, even after AluI digestion of the amplification products. Among the eight isolates collected from the same patient, all typing techniques revealed two clones of strains. The day-to-day reproducibilities of PCR-ribotyping and ERIC-PCR were good, while greater day-to-day variations were noted in the fingerprints obtained by AP-PCR. We conclude that all three PCR techniques are useful for rapid epidemiological typing of B. cepacia, but ERIC-PCR seems to be more reproducible and discriminative.

Two complementary (c)DNA fragments, including the complete open reading frame of fabp2 from the common carp Cyprinus carpio, were cloned by reverse-transcription polymerase chain reaction (RT-PCR). Both were putative intestinal-type fabp genes, named fabp2a and fabp2b. fabp2b was mainly expressed in the intestine and the brain. This gene, however, was nearly not expressed in the liver, heart, pancreas and muscle. fabp2a was only expressed at a very low level in the intestine. Western blot also showed that Fabp2 is relatively highly expressed in the intestine and the brain. Immunohistochemical analysis revealed that Fabp2 is widely distributed in the mucosa of the intestine. These findings provide novel insights into the fabp2 gene molecular evolution, as well as its potential features in the intestine and the brain.

A method to characterize strains of Serratia marcescens based on the PCR amplification of enterobacterial repetitive intergenic consensus sequences has been developed. The PCR fingerprints were generated from boiled supernatants prepared directly from bacterial colonies without the need for DNA extraction. The technique was applied to isolates obtained during an outbreak of pneumonia from seven mechanically ventilated patients, and its result indicated that the outbreak was due to the spread of two epidemic strains. This technique was validated by comparison with rRNA gene restriction analysis. There was complete concordance between these two techniques in discriminating the outbreak-related strains from epidemiologically unrelated isolates. Typing with both biochemical profile and antibiogram profile, though simple, was found to be less reliable than genotyping. The results show that this enterobacterial repetitive intergenic consensus PCR provides a rapid and simple means of typing S. marcescens isolates for epidemiologic studies.

The uncut chip thickness is comparable to the cutting edge radius in micromachining. If the uncut chip thickness is less than a critical value, there will be no chip formation. This critical value is termed as the minimum uncut chip thickness (MUCT). Although minimum uncut chip thickness has been well defined in orthogonal cutting, it is often poorly understood in practical complex turning and milling processes. This paper presents an analysis of the state-of-art research on minimum uncut chip thickness in precision micro-machining. The numerical and experimental methods to determine MUCT values and their effects on process mechanics and surface integrity in microcutting will be critically assessed in this paper. A set of definitions of minimum uncut chip thickness for three-dimensional turning and milling processes are presented. In addition, a detailed discussion on the characteristics of different methods to determine minimum uncut chip thickness and several unsolved problems are proposed for the future work.Copyright © 2011 by ASME

In micromachining, when the undeformed chip thickness becomes comparable to the edge radius of the cutting tool, the effective rake angle becomes to be negative and has significant effect on the determination of the minimum uncut chip thickness. The determination of the minimum uncut chip thickness is essential in micro machining in order to achieve desired surface integrity and accuracy. In this paper, an Arbitrary Lagrangian Eulerian (ALE)-based numerical modeling is proposed to determine the minimum uncut chip thickness for Copper by changing the cutting tool’s nominal rake angle. According to the relationship between the minimum uncut chip thickness and the effective rake angle, a mathematical model that reflects the relationship between the effective rake angle and the nominal rake angle is established.Copyright © 2011 by ASME

A 45-year-old woman presented with subacute pain and swelling of the left thigh for 3 weeks. She reported body weight loss in the past 2 months and had no history of trauma, arthritis or back pain. Physical examination revealed a temperature of 37.8°C and left thigh swelling with localized heat and tenderness. Her white blood cell count was 3100/μl and erythrocyte sedimentation rate was 78 …

The traditional finite element method (TFEM) of analysis requires a large number of elements to have a detailed description of the structure. Other semi-analytical method with additional degree-of-freedoms (DOFs) within an element overcomes this problem, but any revision in the model needs a reformulation of the finite element model for computation. The wavelet finite element method (WFEM) has the advantage of multi-resolution analysis whereby both coarse and detailed descriptions of the structure can be obtained. This paper presents the WFEM based on B-spline wavelet on the interval (BSWI). The shape function is formed by scale function of BSWI and a transformation matrix is constructed between the wavelet and the physical spaces. All the physical parameters in the system are expressed in terms of the transformation matrix and scale function of BSWI. The multi-resolution property of the WFEM is demonstrated with the inverse analysis of moving force identification using several distributed measured dynamic responses. The dynamic programming technique and Tikhonov regularization are used for the identification. Numerical results show that the WFEM has similar accuracy as the TFEM under the same conditions but with fewer finite elements, while the first-order Tikhonov regularization is found capable to remove most of the effect of measurement noise.

A novel moving force and prestress identification method based on finite element and wavelet-based method for bridge-vehicle system is developed. A two-axle vehicle model and simple-supported beam with prestressing force are studied. Finite element method is flexible in modeling structures with complex boundaries while the wavelet-analysis method has the characteristic of multiresolution and the ability to detect abrupt changes. Both methods are used in this work to identify the moving loads and prestressing force from the “measured” bridge responses, which may be strain or acceleration. Numerical simulations demonstrate the efficiency of the method under the effects of measurement noise, road roughness, sampling rate, and the arrangement of sensors with good accuracy. Results indicate that the proposed method has the advantages of both high computational performance and fine identification resolution. DOI: 10.1115/1.2793134

Flavimonas oryzihabitans has emerged as a potential nosocomial pathogen in recent years. The typing method for characterization of this species has never been reported before. Pulsed-field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus (ERIC)-based PCR were used to generate DNA fingerprints for 14F. oryzihabitans isolates obtained from eight episodes of nosocomial infections during a 2-year period. Both techniques successfully classified these clinical isolates into eight distinct genotypes, thus indicating that all of these episodes of infections were independent. In contrast, repeated isolates from the same patient were assigned to identical genotypes. The reproducibility of both techniques was good. Therefore, we conclude that both PFGE and ERIC-PCR have comparable reproducible and discriminatory powers for the typing of F. oryzihabitans and may be useful for clarifying the epidemiology of this species; however, ERIC-PCR has the advantages of both speed and simplicity.

To describe antimicrobial resistance patterns of Enterococcus spp., we measured minimal inhibitory concentrations (MICs) of five antimicrobial agents for 174 clinical isolates of enterococci collected in Taichung Veterans General Hospital from November, 1996 to January, 1998. Major sources included blood (48), the genitourinary tract (39), soft tissue and wounds (28), and the gynecological tract (16). The sensitivity test of vancomycin was performed using the broth microdilution method. The susceptibility of ampicillin, penicillin, gentamicin, and teicoplanin was tested by the agar dilution method. The MIC90 of penicillin, ampicillin, gentamicin, teicoplanin and vancomycin were 2, 1,2,048, 0.125 and 2 microg/mL, respectively. Ampicillin-resistant isolates represented only 4.6% of all enterococci tested. These results reveal that vancomycin-resistant enterococci were found in 1.7% of all enterococci isolates in this study. However, all isolates were sensitive to teicoplanin.

Bacteremia is a major cause of death in renal transplant recipients. However, an understanding of the clinical spectrum of bacteremia post kidney transplantation in Taiwan is lacking. This study was undertaken in an attempt to analyze the causative organisms, the sites of primary infection, and the possible significant determinants of mortality.Eighty-six positive blood cultures from renal transplant recipients were seen at the Taichung Veterans General Hospital from August 1993 to April 1999. Sixty blood cultures obtained from episodes that occurred in 43 kidney recipients were regarded as significant and included. All the data were obtained by reviewing medical records.Forty-six episodes (76.7%) of bacteremia happened 6 months after transplantation. Gram-negative bacilli accounted for 73.3% (44/60) of the cases of bacteremia. Escherichia coli, constituting 26.7% (16/60) of the etiologic agents, was the most common pathogen. In 50.0% of all episodes, urinary tract infection was the main cause of bacteremia. The overall mortality rate in this series was 16.7%. Risk of death seemed higher if bacteremia occurred with a primary site of infection other than the urinary tract (26.7% vs 6.7%) and after methylprednisolone pulse therapy (33.3% vs 12.5%), though both correlations were not statistically significant.This study may shed light on the empirical therapy and better management needed for treating bacteremia in renal transplant recipients in Taiwan and provide a nidus for further prospective surveys.

A transplantable human hepatoma model, the QGY-9204, was used in this study. The growth kinetics of hepatoma in nude mice were compared after injection of parvovirus H-1 into the tumor growth. Significant difference in growth curves were seen between injected groups with H-1 dosages of 5 x 10(7) PFU and 5 x 10(8) PFU and that of control. It indicated that parvovirus H-1 was capable of suppressing the growth of human hepatoma. Previous studies showed H-1 is oncotropic, oncosuppressive and oncolytic. For histological, ultrastructural and histochemical examinations, transplantable hepatomas were taken at different time interval post H-1 (1 x 10(8) PFU per tumor growth) injection. For H-1 DNA amplification and H-1 nonstructural protein expression, PCR and ABC approach in hepatoma paraffin sections were used. The H-1 treated groups exhibited obvious signs of necrosis. It started on 3rd day post infection (3 d.p.i.) and the area of necrosis enlarged consecutively on 7 d.p.i., 10 d.p.i. and 14 d.p.i., but none was seen in saline-injected group even on 14 d.p.i. H-1 virions were also detected in the damaged tumor cells with numerous vacuoles in cytoplasm. Specific band (908 bp) of H-1 DNA and ABC immunostaining indicated H-1 DNA replication and NS-1 expression in tumors of treated groups, their time course was well in accordance with that process of necrosis. These results suggest that parvovirus H-1 promotes tumor necrosis by its DNA replication and cytotoxic NS-1 protein expression, and thus, it inhibits hepatoma growth and induces oncosuppression and oncolysis.

From 1993 to 1998, 29 pyogenic psoas abscesses occurring in 27 patients were seen in Taichung Veterans General Hospital. Their age range was 25 to 85 years. Diabetes mellitus was the leading underlying disease. Fever and pain in the flank area, back and hip were the usual manifestations. The duration of symptoms prior to the diagnosis ranged from 3 days to 6 months. Most abscesses were diagnosed by computed tomography (CT) images and proven by abscess cultures, which were divided into primary and secondary types. Eighteen of 29 abscesses were regarded as primary. Staphylococcus aureus was the most common pathogen in the primary abscesses, followed by Streptococcus agalactiae, Escherichia coli, viridans streptococci, S. epidermidis, and Salmonella spp.. In the secondary abscess category, E. coli was the leading organism in this series, followed by S. aureus, Klebsiella pneumoniae, viridans streptococci and Candida albicans. The associated conditions included epidural abscess, osteomyelitis, septic arthritis, perirenal abscess, pulmonary tuberculosis, empyema, hydronephrosis and trauma history. The initial empiric therapy comprised mostly of cefazolin or oxacillin with or without an aminoglycoside. Thirteen patients underwent percutaneous drainage, while six received surgical debridement, including two with a recurrent abscess. One patient had both drainage and debridement. Others received medical treatment only. Two of the patients with primary abscess died in spite of percutaneous drainage. Therefore, open drainage, besides appropriate antibiotic treatment, is still required to control complex abscesses with sepsis.

The extended-spectrum beta-lactamases (ESBL) are derived from TEM-or SHV-enzymes. They mediate resistance to broad-spectrum beta-lactams and can cause infectious outbreaks in hospitals. Rapid recognition and diagnosis are important for the clinician to prescribe more effective treatment. In the present study, a group of 52 probable ESBL-producing Klebsiella pneumoniae and Escherichia coli having a suspected resistant antibiogram phenotype were included. The E-test ESBL screen and the double disk test were performed for these isolates for detection of ESBL-producing strains, as compared with the conventional agar dilution method. The agreement between the E-test ESBL screen or the double disk test and the conventional agar dilution method was good and the degree of agreement were 86.5% and 92.3% respectively. The results showed that both the E-test ESBL screen and the double disk test were useful and convenient for detection of ESBLs.

A renal abscess, caused by Serratia marcescens with endophthalmitis in a 68-year-old diabetic female, is described. Endophthalmitis presented with visual loss, conjunctiva injection and lid edema with eye pain. Right costovertebral knocking pain was also noted. Sonography and computed tomography of abdomen showed a 4 cm hypoechoic lesion in the middle portion of the right kidney with marginal enhancement after contrast media injection. Percutaneous abscess drain was performed. Pus culture from the drain tube revealed S. marcescens, yet, vitreous cultures yielded no growth, which was ascribed to previous antibiotics use. Although vitrectomy, fortified eye drops, intravitreal and systemic intravenous antibiotics were administered, the visual function was still lost. To our knowledge, this is the first reported case of S. marcescens renal abscess complicated with endophthalmitis.

Infections caused by Streptococcus pneumoniae continue to be a significant cause of mortality and morbidity in humans. Diseases caused by multi-resistant pneumococci are increasing rapidly worldwide. The fluoroquinolones have been widely used clinically to treat infectious diseases. The results of a study here on the five fluoroquinolones susceptibilities of S. pneumoniae are reported from the Taichung Veterans General Hospital.Minimum inhibitory concentrations (MICs) of five quinolones (enoxacin, norfloxacin, ofloxacin, levofloxacin and ciprofloxacin) were determined for 106 strains of S. pneumoniae. All MICs were determined by the agar dilution method utilizing Mueller-Hinton agar supplemented with 5% sheep blood.MIC90 of levofloxacin was 1 microgram/ ml, and was unaffected by penicillin-susceptibility. MIC90 of ofloxacin and that of ciprofloxacin were 2 and 4 micrograms/ml, respectively, with 90.6% sensitive to ofloxacin. MIC90 of enoxacin and that of norfloxacin were higher than other compounds.The in vitro activity of levofloxacin is twice that of ofloxacin, 4-fold of ciprofloxacin, 16-fold of norfloxacin, and 64-fold of enoxacin. MICs of these five quinolones were unaffected by penicillin-susceptibility. The antibacterial activity of levofloxacin was better than that of ofloxacin and ciprofloxacin, norfloxacin, or enoxacin against S. pneumoniae.

The mixture of platelet-activating factor (PAF) and platelets produced significant contraction of guinea pigs' bronchus, while the contraction induced by PAF alone was mild relatively, the IC50 were 6.14 x 10(-7) mol/L and 6.32 x 10(-4) mol/L respectively. There was significant difference between these two groups (P0.05). When the platelets were pre-incubated with ginkgolides for 10 minutes in Tris-Tyrode's buffered saline, effects of the PAF and platelets mixture were significantly inhibited (P0.01). Exposure of guinea pigs' bronchus to PAF in vitro resulted in a loss of beta-adrenergic receptors and responses to isoproterenol, and this effect of PAF was prevented by prior incubation of the guinea pigs' bronchus with ginkgolides (P0.05). The results showed ginkgolides were a potent PAF antagonist.

We actively adopted method to control hepatitis C (HC) epidemic in blood sampling. ELISA was used to detect anti-HCV antibody in different groups of 2348 blood donors. The positive rates of anti-HCV for plasmaphersis and whole blood donors were 0.58% (2/343) and 1.34% (27/2005) respectively, with no statistical significance (P0.05). The positive rates of anti-HCV for plasmapheresis donors in 1-2 years and over 9 years were 0.99% (7/701) and 0.74% (2/270) respectively. There was no significant difference (P0.05) either. The positive rates of anti-HCV for plasmapheresis donors in 1992 and in 1994 were 1.64% (7/426), and 0.58% (2/343). The results showed that HCV infection rate did not increase in plasmapheresis donors, nor did it increase parallel with the increasing gears of blood donnation.