Search

Document classification is a supervised machine learning process, where predefined category labels are assigned to documents based on the hypothesis derived from training set of labelled documents. Documents cannot be directly interpreted by a computer system unless they have been modelled as a collection of computable features. Rogati and Yang [M. Rogati and Y. Yang, “Resource selection for domain-specific cross-lingual IR”, in SIGIR 2004: Proceedings of the 27th annual international conference on Research and Development in Information Retrieval, ACM Press, Sheffied: United Kingdom, pp. 154–161.] pointed out that the effectiveness of document classification system may vary in different domains. This implies that the quality of document model contributes to the effectiveness of document classification. Conventionally, model evaluation is accomplished by comparing the effectiveness scores of classifiers on model candidates. However, this kind of evaluation methods may encounter either under-fitting or over-fitting problems, because the effectiveness scores are restricted by the learning capacities of classifiers. We propose a model fitness evaluation method to determine whether a model is sufficient to distinguish positive and negative instances while still competent to provide satisfactory effectiveness with a small feature subset. Our experiments demonstrated how the fitness of models are assessed. The results of our work contribute to the researches of feature selection, dimensionality reduction and document classification. [ABSTRACT FROM AUTHOR]

Fuzzy data has grown to be an important factor in data mining. Whenever uncertainty exists, simulation can be used as a model. Simulation is very flexible, although it can involve significant levels of computation. This article discusses fuzzy decision-making using the grey related analysis method. Fuzzy models are expected to better reflect decision-making uncertainty, at some cost in accuracy relative to crisp models. Monte Carlo simulation is used to incorporate experimental levels of uncertainty into the data and to measure the impact of fuzzy decision tree models using categorical data. Results are compared with decision tree models based on crisp continuous data. [ABSTRACT FROM AUTHOR]

Intestinal fatty-acid binding protein (I-FABP, also called FABP2) is involved in the uptake of dietary fatty acids in the intestine, and its binding specificity is only with long-chain fatty acid. In this study, sequences of 4 exons in pigeon FABP2 were successfully amplified. The encoded protein had a molecular weight of 15.13 kDa and the theoretical pI was 6.75. Bioinformatics analysis indicated that the protein was predicted to contain 10 potential phosphorylation sites and did not contain signal peptide structure. The evolutionary analysis suggested the amino acid sequence of pigeon FABP2 was closest to the mallard (Nippoia nippon) homologs. Meanwhile the expression of FABP2 mRNA in different ages and tissues we conducted. It showed that the expression of the FABP2 gene was the highest in the liver, followed by the small intestine and adipose tissue, while lowest in the breast muscle. Also, the expression level in the gizzard was gradually increased with aging. Our results may serve as reference to better studies of the functional characterization and structure of the FABP2 in pigeon. [ABSTRACT FROM AUTHOR]

A novel biosensor was prepared by using gold nanoparticles (AuNPs) signal amplification technology combined with liquid crystal biosensor to detect Cecropin B (CB). The surface of the substrate was modified with (3-aminopropyl)-triethoxysilane/N,N-dimethyl-N-octadecyl-(3-aminopropyl)-trimethoxysilyl chloride (APTES/DMOAP), glutaraldehyde (GA) as crosslinking, the AuNPs and Cecropin B antibody (anti-CB) complex could be fixed on the basal surface. CB and anti-CB can bind to make the liquid crystal (LC) changes in a vertical orientation, so as to achieve the purpose of testing. The volume of AuNPs is much larger than that of CB and anti-CB, thus AuNPs can play the role of signal amplification. Compared to the experiments without nano-gold amplification, our method has a lower detection limit. Finally, the limit of CB detection could be as low as 1.49 × 10−2 ng/mL. This method has the advantages of good specificity, high sensitivity, low detection limit and simple operation. [ABSTRACT FROM AUTHOR]

This study aims to model the complex relationship among the traffic characteristics (i.e. traffic flow, traffic speed, traffic density), environmental conditions (i.e. darkness condition, weather condition and traffic lane width) and frequency of ship collisions in the Yangtze River estuary areas. Taking into account the effects of ship approach angle, ship type, relative speed and darkness condition on the capability of ship collision avoidance, a dynamic ship domain model has been presented to measure ship collision frequency. Considering the big variation associated with the collision frequency, the measured ship collision frequency is further modeled as a loglogistic-distributed function of traffic characteristics and environmental conditions. Results show that the collision frequency is greater for (i) the bigger traffic flow; (ii) the bigger traffic density; (iii) the narrower traffic lane width; and (iv) the adverse weather condition. The darkness condition is the influencing factor that produces the biggest effect on the ship collision frequency. [ABSTRACT FROM AUTHOR]

This paper proposes the almost output regulation model reference adaptive control problem for switched systems with parametric uncertainties and multiple types of disturbances. By the almost output regulation model reference adaptive control strategy, the parametric uncertainties are suppressed and the multiple types of disturbances are rejected, simultaneously. In order to improve the transient performance of switched systems, the combined model reference adaptive control strategy is applied. A key point is to set up the almost output regulation model reference adaptive control strategy to achieve the tracking and the disturbance rejection performance. First, we design a switched identification model to estimate the plant uncertain parameters, by which more accurate plant parameters will be obtained. Secondly, based on the switched identification model, controllers with combined adaptive laws and a state-dependent switching law are designed to solve the almost output regulation model reference adaptive control problem for switched systems. Finally, a sufficient condition is given, which guarantees that the problem of the almost output regulation model reference adaptive control for switched systems is solvable in spite of the problem of almost output regulation model reference adaptive control for each subsystem is not solvable. [ABSTRACT FROM AUTHOR]

This paper considers the output-feedback fault-tolerant tracking control problem for a class of uncertain nonlinear switched systems with nonlinear faults and strict-feedback form, where the faults which are nonaffine occur on the actuator. As a kind of specialised function approximating tool, fuzzy logic systems (FLSs), are employed to approximate the unknown smooth nonlinear functions. A switched fuzzy observer is designed to address the problem of unmeasurable states, filtered signals are used to address algebraic loop problem and the average dwell time (ADT) method is further utilised to prove the stability of the resulting closed-loop systems under a type of slowly switching signals. Based on the backstepping recursive design technique and Lyapunov function method, an adaptive fuzzy output-feedback control scheme is developed. The developed control method can ensure all the signals are semi-globally uniformly ultimately bounded (SGUUB) and the system output tracks the reference signal tightly even if unknown fault occurs. A simulation carried on an example demonstrates the validity of the obtained control scheme. [ABSTRACT FROM AUTHOR]

To map sand grain size distribution using Unmanned Aerial Vehicle (UAV) digital cameras, we conducted experiments for six sand classes with the UAV images acquired at six different heights. We used the maximum likelihood classification and the Grey Level Co-occurrence Matrix texture indices on the images and evaluated classification accuracy under each flight height/image resolution. The image at the spatial resolution of 1.23 mm can effectively separate all six classes. The image of lower resolutions were only effective for coarser classes with an overall accuracy of 83.92% or better: the 2.48 mm pixel size was good for the four classes coarser than medium sand; 3.78 mm was good for the three classes coarser than coarse sand; 4.89 and 5.42 mm were good for the two coarsest classes of sand and gravel. This research is the first comprehensive study to test different UAV survey quality control parameters for sand classification, which could serve as a guidance for UAV survey parameter selection such as flight height and quality of digital cameras. [ABSTRACT FROM AUTHOR]

Reactive oxidative compounds including superoxide anions and nitric oxide are believed to play a central role in many blinding eye diseases. In the present study, we examine the effect of ischemia on human retinal pigment epithelial (RPE) cells in an unusual clinical case. We show that ischemia leads to extensive nitrotyrosine deposition in the RPE and choroid, thus indicating NO-dependent oxidative stress. We also show for the first time the in vivo translocation of glyceraldehyde-3-phosphate-dehydrogenase (GAPDH) to the nuclei of RPE cells. This enzyme's nuclear translocation has previously been demonstrated in vitro where it is a marker of apoptosis. Furthermore, nitrotyrosine deposition and GAPDH translocation have been duplicated in vitro using human RPE cells. Thus, nitrotyrosine formation and GAPDH trafficking to the nucleus may be observed during ischemic conditions. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to evaluate the clinical characteristics and clinical course of Asian elderly-onset Crohn’s disease (EOCD) patients in a large well-defined cohort of South Korean IBD patients. Materials and methods: From the Asan inflammatory bowel disease registry, we identified 29 EOCD patients (diagnosed with CD in age of 60 years or over) out of 2989 CD patients (1.0%). After excluding two patients with unclear data, 27 EOCD were matched with 108 young-onset CD (YOCD) and 108 middle age-onset CD (MOCD) for the interval from symptom onset to diagnosis (±3 years) and follow-up duration (±3 years). Results: Females were predominant in the EOCD group (59.3%) compared to MOCD (31.5%) and YOCD (29.6%) groups (p = .012). In EOCD group, terminal ileal location was the most common (63.0%) at diagnosis, whereas ileocolonic location in other groups (57.4% in MOCD and 78.7% in YOCD, respectively) (p < .001). Patients with perianal fistula at CD diagnosis were less common (14.8% in EOCD vs. 28.7% in MOCD vs. 49.1% in YOCD, p < .001). During follow-up, thiopurines were used less frequently in the EOCD group (48.1% in EOCD vs. 87.0% in MOCD vs. 89.8% in YOCD, p < .001), but the risk for intestinal resection was comparable among three groups (p = .583). Conclusions: EOCD may have a better clinical course than MOCD and YOCD, as demonstrated by the similar risk for intestinal resection despite the less frequent use of thiopurines. [ABSTRACT FROM AUTHOR]

Emotion is widely agreed to have two dimensions, valence and arousal. Few studies have explored the effect of emotion on conflict adaptation by considering both of these, which could have dissociate influence. The present study aimed to fill the gap as to whether emotional valence and arousal would exert dissociable influence on conflict adaptation. In the experiments, we included positive, neutral, and negative conditions, with comparable arousal between positive and negative conditions. Both positive and negative conditions have higher arousal than neutral ones. In Experiment 1, by using a two-colour-word Flanker task, we found that conflict adaptation was enhanced in both positive and negative contexts compared to a neutral context. Furthermore, this effect still existed when controlling stimulus–response repetitions in Experiment 2, which used a four-colour-word Flanker task. The findings suggest emotional arousal enhances conflict adaptation, regardless of emotional valence. Thus, future studies should consider emotional arousal when studying the effect of emotion on conflict adaptation. Moreover, the unique role of the emotional context in conflict-driven cognitive control is emphasised. [ABSTRACT FROM AUTHOR]

Background:Large-scale studies regarding the long-term efficacy of infliximab (IFX) treatment in non-Caucasian patients with ulcerative colitis (UC) are lacking. Study:We analyzed the long-term outcomes of IFX in 195 Korean UC patients who received scheduled IFX treatments at Asan Medical Center. IFX failure was defined as IFX discontinuation due to colectomy or non-response to IFX, and additionally UC-related hospitalization or a need for rescue corticosteroids during the course of IFX. Results:Between December 2006 and October 2016, a total of 3101 infusions of IFX were administered to 195 patients over a median period of 21 months. At the end of the follow-up, 86 patients (44.1%) were still receiving IFX without failure. IFX was stopped in 73 (37.4%) patients due to colectomy (23 patients, 11.8%), non-response to IFX (35 patients, 17.9%) or other reasons such as adverse events or patients’ preferences (15 patients, 7.7%). An additional 36 (18.5%) patients experienced IFX failure during follow-up due to a need for rescue corticosteroids (13 patients, 6.7%), UC-related hospitalization (8 patients, 4.1%), or both (15 patients, 7.7%). The survival free of IFX failure was 58.1% at 1 year, 50.7% at 3 years and 44.8% at 5 years. In a multivariate regression analysis, cytomegalovirus colitis within 3 months before IFX initiation was a predictor of IFX failure (hazard ratio 1.57; 95% confidence interval 1.04–2.37;p = .032). Conclusions:The long-term efficacy of IFX in a large, real-life cohort of Korean UC patients appears to be comparable to that in previously published Western studies. [ABSTRACT FROM AUTHOR]

An investigation on the structural, electronic, thermodynamic, and mechanical properties of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX)/2-methylpyridine-N-oxide (MPNO) cocrystal was carried out from 0 to 100 GPa by using a dispersion-corrected density functional theory (DFT-D) method. Our calculated crystal structure is in excellent agreement with experimental results at ambient pressure. Based on the analysis of lattice parameters, lattice angles, bond lengths, bond angles, and dihedral angles under high pressure, we observe that HMX molecules in the cocrystal bulk are seriously distorted but MPNO molecules remain relatively unchanged. Hydrogen bond lengths are greatly shortened under high pressure. In addition, with the increase in pressure, the bandgap decreases gradually. However, it increases suddenly at 70 GPa. Some important hydrogen bonds between HMX and MPNO are also observed in the density of states spectrum. According to the thermodynamic analysis, this cocrystal is more easily prepared under low pressure. Finally, we characterized its mechanical properties and the results show that this cocrystal is malleable in nature. We expect that this research can provide a fundamental basis for further HMX cocrystal design and preparation. [ABSTRACT FROM PUBLISHER]

Late Triassic–Early Jurassic intrusions of the Erguna Block, Northeast China, are located along the southern margin of the Mongol–Okhotsk orogenic belt. They comprise granodiorite, monzogranite, syenogranite, and lesser gabbro–diorite, of adakitic and calc­alkaline affinity. The adakite-like and calc­alkaline granites share similar light rare earth elements (LREE) characteristics; however, their heavy rare earth elements (HREE) trends differ from one another. The relative abundances of HREE in the calc­alkaline granites are relatively consistent and are similar to those of intrusive rocks formed from dehydration melting of garnet-free amphibolitic source rocks at relatively low pressures. In contrast, the adakite-like granites show more prominent HREE fractionation trends, indicating that they crystallized at higher pressures, where garnet in the source rocks was stable. At least two isotopically distinct sources were involved in the petrogenesis of the granites, but the extent to which they contributed varies between plutons. Most intrusions have incorporated an isotopically primitive component, possibly juvenile mafic crust. The other sources include a small proportion of old continental crustal material and isotopically evolved wall rocks. The gabbro–diorites have high MgO contents (>7 wt.%), a high Mg#(>0.6), and show moderate LREE and HREE fractionation, indicating they formed from the melting of subducted metasomatized lithospheric mantle. All of the intrusions in the study area are characterized by a relative enrichment in large ion lithophile elements (LILE) and depletion in high field strength elements (HFSE), indicating they were emplaced in an Andean-type active continental margin setting related to southward subduction of the Mongol–Okhotsk oceanic plate. [ABSTRACT FROM PUBLISHER]

1. The primary objective of this study was to evaluate the effects of quercetin on the pharmacokinetics of cefprozil. The secondary objective was to evaluate the safety of the combined use of cefprozil and quercetin. 2. An open-label, two-period, crossover phase I trial among 24 Han Chinese male subjects was conducted. Participants were given 500 mg of quercetin orally once daily for 15 d followed by single dose of cefprozil (500 mg) on day 15. Serum concentrations of cefprozil were then measured in all participants on day 15. A 15-d washout period was then assigned after which a 500 mg dose of cefprozil was administered and measured in the serum on day 36. 3. All subjects completed the trial, and no serious adverse events were reported. We measured mean serum concentrations of cefprozil in the presence and absence of quercetin in all participants. The maximum serum concentration of cefprozil in the presence of quercetin was 8.18 ug/ml (95% CI: 7.55–8.81) versus a maximum cefprozil concentration of 8.35 ug/ml (95% CI: 7.51–9.19) in the absence of quercetin. We conclude that the concurrent use of quercetin has no substantial effect on serum concentrations of orally administered cefprozil. 4. Co-administration of quercetin showed no statistically significant effects on the pharmacokinetics of cefprozil in healthy Chinese subjects. [ABSTRACT FROM AUTHOR]

Nanomaterial pollution and the spread of antibiotic resistance genes (ARGs) are global public health and environmental concerns. Whether nanomaterials could aid the transfer of ARGs released from dead bacteria into live bacteria to cause spread of ARGs is still unknown. Here, we demonstrated that nano-Al2O3could significantly promote plasmid-mediated ARGs transformation into Gram-negativeEscherichia colistrains and into Gram-positiveStaphylococcus aureus; however, bulk Al2O3did not have this effect. Under suitable conditions, 7.4 × 106transformants ofE. coliand 2.9 × 105transformants ofS. aureuswere obtained from 100 ng of a pBR322-based plasmid when bacteria were treated with nano-Al2O3. Nanoparticles concentrations, plasmid concentrations, bacterial concentrations, interaction time between the nanomaterial and bacterial cells and the vortexing time affected the transformation efficiency. We also explored the mechanisms underlying this phenomenon. Using fluorescencein situhybridization and scanning electron microscopy, we found that nano-Al2O3damaged the cell membrane to produce pores, through which plasmid could enter bacterial cells. Results from reactive oxygen species (ROS) assays, genome-wide expression microarray profiling and quantitative real-time polymerase chain reactions suggested that intracellular ROS damaged the cell membrane, and that an SOS response promoted plasmid transformation. Our results indicated the environmental and health risk resulting from nanomaterials helping sensitive bacteria to obtain antibiotic resistance. [ABSTRACT FROM PUBLISHER]

Effective building/house energy management has been considered as an efficient way to mitigate the fluctuation of renewable energy in power distribution system. This article studies the operation scheduling problem for microgrid with high penetration of solar power and thermostatically controlled loads. Based on the established photovolaic model and thermostatically controlled load model, an optimal operation strategy for microgird is proposed. The scheme is based on the rolling horizon optimization strategy, where the control window continues to proceed with the update of real-time information, aiming to minimize the total operation costs over the current control window. Differential evolution algorithm is used to solve the proposed model, and the simulation results validate the efficiency of the proposed method. [ABSTRACT FROM AUTHOR]

Guided bone regeneration (GBR) is a technique where a barrier membrane is placed over the bone defect to prevent cell growth from the connective tissue and epithelium. Titanium (Ti) has excellent mechanical properties and is one of the most frequently used materials in implant dentistry. This study examined how graphene oxide (GO)-coated Ti (GO-Ti) membranes can enhance the osteogenesis of MC3T3-E1 preosteoblasts and promote new bone formation for potential applications to GBR. The physicochemical properties of GO-Ti membranes were characterized by atomic force microscopy, Raman spectroscopy, X-ray diffraction, and contact angle measurements. The cellular behaviors of MC3T3-E1 preosteoblasts on GO-Ti membranes were examined by cell counting kit-8 and alkaline phosphatase (ALP) activity assays. The effects of GO-Ti membranes on bone regeneration were evaluated by implanting them into rat calvarial defects. GO was coated uniformly on Ti substrates, which allowed a decrease in surface roughness and contact. GO-Ti membranes stimulated significantly ALP activity without interfering with their proliferation. Furthermore, GO-Ti membranes enhanced new bone formation significantly in full-thickness calvarial defects without inflammatory responses. Therefore, this suggests that GO-Ti membranes can be applied effectively to GBR because these graphene-coated Ti membranes have potent effects on stimulating osteogenic differentiation and exhibit superior bioactivity. [ABSTRACT FROM PUBLISHER]

Previous studies have shown that negative emotional distracters impair conscious inhibitory control. Recent research has shown that inhibitory control can be triggered unconsciously; therefore, in Experiment 1, we aimed to investigate whether negative emotional distracters affect unconscious inhibitory control. Furthermore, in Experiment 2, we examined whether fearful and disgusting distracters have differential effects on unconscious inhibitory control. Participants were instructed to perform a masked Go/No-Go task superimposed on a negative or neutral image cue (Experiment 1) or on a fearful, disgusting or neutral image cue (Experiment 2). Results showed that negative emotional distracters impaired unconscious inhibitory control; furthermore, disgusting distracters impeded unconscious inhibitory control when compared to fearful ones. This study is the first to provide evidence that fear and disgust may affect unconscious inhibitory control differently. These results expand the understanding of the relationship between emotions and inhibitory control. [ABSTRACT FROM PUBLISHER]

BackgroundThe impact of genetic variation in thethiopurine S-methyltransferase (TPMT)gene on thiopurine-induced leukopenia has been well demonstrated. Although xanthine dehydrogenase (XDH)is the second major contributor to azathioprine breakdown, polymorphisms inXDHhave rarely been studied in IBD patients. We aim to access association betweenXDHvariants and thiopurine-induced leukopenia by gene–gene interaction in a Crohn’s disease (CD) population.StudyA total of 964 CD patients treated with thiopurines were recruited from a tertiary referral center. The association between fourXDHvariants (p.Gly172Arg, p.Asn1109Thr, p.Arg149Cys, and p.Thr910Lys) and thiopurine-induced leukopenia was analyzed in cases with early leukopenia (n = 66), late leukopenia (n = 264), and in controls without leukopenia (n = 632). Three non-synonymous SNPs, which we previously reported association with thiopurine-induced leukopenia,NUDT15(p.Arg139Cys),SUCLA2(p.Ser199Thr), andTPMT *3Cwere selected for epistasis analysis with theXDHvariants.ResultsThere was no significant association for two variants ofXDHand thiopurine-induced leukopenia. In the epistasis analysis, onlyXDH(p.Asn1109Thr) *SUCLA2(p.Ser199Thr) showed a statistically significant association with early leukopenia [odds ratio (OR) = 0.16;p = 0.03]. After genotype stratification, a positive association on the background ofSUCLA2wild-type (199Ser) between theXDH(p.Asn1109Thr) and early leukopenia (OR = 4.39;p = 0.01) was detected.ConclusionGenes associated with thiopurine-induced leukopenia can act in a complex interactive manner. Further studies are warranted to explore the mechanisms underlying the effects of the combination ofXDH(p.Asn1109Thr) andSUCLA2(199Ser) on thiopurine-induced leukopenia. [ABSTRACT FROM PUBLISHER]

The potential risks of nano-materials and the spread of antibiotic resistance genes (ARGs) have become two major global public concerns. Studies have confirmed that nano-alumina can promote the spread of ARGs mediated by plasmids. Nano-titanium dioxide (TiO2), an excellent photocatalytic nano-material, has been widely used and is often present in aqueous environments. At various nano-material concentrations, bacterial density, matting time, and matting temperature, nano-TiO2 can significantly promote the conjugation of RP4 plasmid in Escherichia coli. We developed a mathematical model to quantitatively describe the conjugation process and used this model to evaluate the effects of nano-TiO2 on the spread of ARGs. We obtained analytical solutions for total and resistant bacteria, which were enumerated by the abundance of genetic loci unique to the plasmid and the chromosome using qPCR. Our results showed that the mathematic model was able to fit the experimental data well and can be used to quantitatively evaluate the effects of nano-TiO2. According to our model, the presence of nano-TiO2 decreased the bacterial growth rate from 0.0360 to 0.0323 min−1 and increased the conjugative transfer rate from 6.69 × 10−12 to 3.93 × 10−10 mL cell−1 min−1. These results indicate that nano-TiO2 inhibited bacterial growth and promoted conjugation simultaneously. The data for morphology and mRNA expression also demonstrated this phenomenon. Our results confirm that environmental nano-TiO2 may cause the spread of ARGs and thus poses an environmental risk. In addition, we provide a potential method for monitoring changes in ARGs that result from conjugation and evaluating the effects of antimicrobial substances on ARG expression. [ABSTRACT FROM AUTHOR]

Objectives. To investigate the optimal cut-off of the maximum standard uptake value (SUVmax) for the detection of colorectal neoplasms and to suggest those for whom further colonoscopy is recommended among patients with incidental colonic uptake on positron emission tomography-computed tomography (PET-CT). Materials and methods. In 306 patients who underwent colonoscopy within 3 months of receiving PET-CT between January and December 2009, measurements of the per-patient and per-lesion diagnostic performance of PET-CT for the detection of colonic neoplasms were obtained. Receiver operating characteristic (ROC) analysis was used to identify the SUVmax that provided a high probability of diagnosing malignancy and high-grade dysplasia. Results. The per-patient and per-lesion PET-CT detection sensitivities for malignancies were 93.3% (28/30; 95% confidence interval (CI) 76.5% to 98.9%) and 93.5% (29/31, 95% CI 77.2% to 98.9%), respectively; the sensitivities for high-grade dysplasia were both 90.0% (9/10; 95% CI 54.1% to 99.5%). As a criterion to specifically detect both malignancy and high-grade dysplasia on focal uptake, a SUVmax greater than 2.5 yielded a 92.3% per-lesion sensitivity and a 42.9% per-lesion positive predictive value (PPV). In the ROC curve analysis, a cut-off value of SUVmax = 5.8 was established, at which the sensitivity, PPV and positive likelihood ratio for diagnosing malignancy and high-grade dysplasia were 71.8% (28/39; 95% CI 54.9% to 84.5%), 84.8% (28/33; 95% CI 67.3% to 94.3%) and 6.9, respectively. Conclusion. The optimal cut-off value to identify a malignancy or high-grade dysplasia was SUVmax = 5.8. However, to avoid missing a malignancy or high-grade dysplasia, a colonoscopy should be performed above a SUVmax = 2.5. [ABSTRACT FROM AUTHOR]

Goals. The purpose of this study is to investigate the learning curve for colonoscopic polypectomy (CP) by trainee endoscopists. Background. The amount of training required to achieve technical competence for CP is uncertain. Study. The CP times and en bloc resection rates of three experienced colonoscopists were obtained from 240 procedures. These data were compared to those of three gastroenterology trainees who performed 750 CP procedures. A trainee procedure was deemed to be a success if en bloc resection was obtained and the CP time was within twice the median CP time of the experienced colonoscopists. Trainees were deemed to be technically competent when they achieved a CP success rate of greater than or equal to 80%. Results. The median CP times and en bloc resection rates for the experienced colonoscopists and trainees were 79 s (range, 20-301 s) and 99.6% (239/240), and 118 s (range, 36-1051 s) and 95.6% (717/750), respectively. The trainee success rate of CP was 72% (540/750). The success rate of the procedure was associated with increased trainee experience ( p = 0.003) and reached 80% after 250 procedures. The CP time significantly decreased ( p < 0.001) and en bloc resection rate significantly increased ( p = 0.011) as trainee experience accumulated. The level of experience was an independent predictor for successful CP. Conclusions. The achievement of technical competence with CP was associated with an accumulation of approximately 250 procedures. These findings suggest that dedicated education and training programs for CP are warranted. [ABSTRACT FROM AUTHOR]

Objective. Limited data are available on the incidence and risk factors of colorectal cancer (CRC) in Asian patients with inflammatory bowel disease (IBD). Material and methods. Information on 5212 Korean patients with IBD (2414 with Crohn's disease [CD] and 2798 with ulcerative colitis [UC]) was retrieved from the IBD registry of Asan Medical Center. Data on CRC incidence for the entire Korean population were derived from the Korean Statistical Information Service. Results. During 39,951 person-years of follow-up (17,679 for CD and 22,272 for UC), 30 patients (12 with CD and 18 with UC) developed CRC. The standardized incidence ratio (SIR) of CRC was 6.0 (95% confidence interval [CI], 3.10-10.48) for CD and 1.68 (95% CI, 1.00-2.66) for UC; it was 9.69 (95% CI, 5.01-16.93) for CD with colonic involvement and 4.31 (95% CI, 2.46-7.00) for extensive UC. The SIR was also increased in patients diagnosed with IBD at younger than 30 years old. CRC location was the low rectum in 11 of 12 CD patients (91.7%). The cumulative probability of rectal cancer was higher in CD patients with a perianal fistula than in those without a perianal fistula ( p = 0.02). Conclusions. A high prevalence of perianal fistulas in Korean CD patients may be the cause of the predominance of low rectal cancer in this population and the higher SIR of CRC in Koreans than in Westerners. In contrast, the SIR of CRC in Korean UC patients may be similar to that in Western UC patients. [ABSTRACT FROM AUTHOR]

Abstract—This article presents a stator and rotor current observer for a doubly fed induction generator. First, the dynamic models of the wind turbine drive train are presented, and the vector control strategies of a doubly fed induction generator for the rotor-side and grid-side converters are described. A stator and rotor current observer model, which is based on the state–space models of doubly fed induction generators, is then derived by using the stator and rotor voltage signals as inputs. To demonstrate the effectiveness of the proposed current observer, its dynamic performance is simulated using a MATLAB/Simulink software platform under the conditions of active power change of doubly fed induction generators and grid voltage dip fault. Furthermore, the robustness of the proposed current observer is investigated when the doubly fed induction generator rotor resistance is changed. Results show that the proposed observer has good coherence and robustness with the current sensor output when the doubly fed induction generator is in dynamic and transient responses. Compared with the referenced bilinear observer, the proposed observer has better fault-tolerant ability when the fault in the observed current sensor occurs. [ABSTRACT FROM PUBLISHER]

Three new phenolic constituents 1–3 were obtained from the 95% ethanol extract of the roots of Phyllodium pulchellum (Leguminosae). Their structures were elucidated on the basis of spectroscopic analyses, such as NMR, UV, IR, HR-ESI-MS, and CD. Furthermore, in an in vitro bioassay, all compounds were tested for inhibitory effects against the proliferation of acetaldehyde-stimulated HSC-T6 cells, and compound 3 exhibited potent inhibitory activity with the IC50 value of 7.6 μM. [ABSTRACT FROM AUTHOR]

Altered blood pressure (BP) regulation and heart rate variations are characteristic findings of cardiovascular dysautonomia in patients with Parkinson’s disease (PD). However, these variations had not been adequately investigated. The aim of this study was to investigate the patterns and characteristics of 24-hour BP and heart rate variations in patients with PD. Case-control comparisons of 139 consecutive newly diagnosed patients with PD and 55 age-matched controls were performed. All cases underwent clinical assessments and 24-hour ambulatory BP monitoring. The associations among BP and heart rate variations and parkinsonian motor symptoms were investigated. There were significant differences in the distribution of non-dipping, the percent of nocturnal BP decrease, nighttime BP level, the standard deviation of heart rate, and nocturnal decrease of heart rate between patients with PD and controls. However, these abnormal diurnal BP and heart rate patterns were not associated with parkinsonian motor symptoms and not related to age, gender, or disease duration. In conclusion, this result suggests daily BP and heart rate abnormalities may be one of the circadian cardiovascular autonomic dysfunctions in patients with PD, irrespective of age, disease severity, or motor symptom phenotype. [ABSTRACT FROM AUTHOR]

Objective. The long-term efficacy of azathioprine (AZA) in steroid-dependent ulcerative colitis (UC) is still unclear. We aimed to evaluate the efficacy of AZA in patients with steroid-dependent UC. Material and methods. We retrospectively reviewed die medical records of 106 patients with steroid-dependent UC who were administered AZA. Three-year outcomes of AZA therapy were evaluated. The outcome of the treatment was defined as (1) success, indicating induction and maintenance of remission throughout the study period (complete success) or remission followed by infrequent and short relapses (partial success); or (2) failure, indicating the absence of remission, frequent or prolonged relapses, infliximab administration, or colectomy. Results. Of the 106 patients, 73 (68.9%) continued on AZA for >6 months (AZA therapy group) and 33 (31.1%) discontinued AZA within 6 months due to intolerance (AZA intolerance group, n = 20), colectomy (n = 6), or follow-up loss (n = 7). Three-year outcomes for 106 patients were success in 54.7% (complete success, 35.8%; partial success, 18.9%), failure in 32.1% (frequent or prolonged relapses, 12.3%; infliximab administration, 5.6%; colectomy, 14.2%), and follow-up loss or death in 13.2%. The success rate increased to 71.2% (complete success, 46.6%; partial success, 24.7%) when the analysis was confined to the 73 patients who continued AZA for > 6 months. The 3-year success rate was higher in the AZA therapy group (71.2%) than the AZA intolerance group (25.0%) (p < 0.001). Conclusions. AZA is an effective treatment for steroid-dependent UC. The efficacy of AZA is well sustained over 3 years. [ABSTRACT FROM AUTHOR]

In this work, arabinoxylan-graft-acrylic acid (AX-g-AA) hydrogel was prepared and used as an adsorbent to remove and recover Cu2+and Ni2+from aqueous solutions. The influences of pH, ligand content on the adsorption capacity of the hydrogel, adsorption equilibrium, and kinetic were studied in detail. The competitive adsorption and recovery of heavy metal ions, regeneration and reusability of the hydrogel were present. Furthermore, the relationship between the physiochemical properties of the adsorbent and its adsorption performance was also studied. The results showed that a more expanded network favored the diffusion and adsorption of metal ions. Cu2+and Ni2+uptake by this hydrogel was pH and concentration dependent with the maximum loading of 330.1 mg/g for Cu2+and 248.7 mg/g for Ni2+. The pseudo-second-order kinetics suggested that the ion exchange process was chemisorption-controlled. The Langmuir equation could well describe the isotherm data. Cu2+and Ni2+adsorbed on the hydrogel could be effectively recovered in a diluted HNO3solution (0.01 M) in 30 min. AX-g-AA hydrogel also exhibited highly efficient reusability, and thus could be used repeatedly. [ABSTRACT FROM AUTHOR]

Here we review our work on incorporating high refractive index inorganic materials into microstructures by two-photon lithography. We describe the direct writing of silver microstructures from dispersions of silver salt solutions, as well as the fabrication of silver nanoparticle embedded microstructures by a combination of UV exposure and thermal curing. The last section summarizes the functionalization of semiconductor quantum dots for their incorporation into microstructures. These materials pave the way for new investigations into photonic properties of hybrid inorganic nanomaterial incorporated microstructures. [ABSTRACT FROM PUBLISHER]

First-principle calculation is used to study the influence of uniaxial strain on the heat capacity and thermal conductivity of hydrogen passivated graphene nanoribbons. It is found that, the frequency of lattice vibration modes shifts down with increasing strain, and the thermodynamic properties change correspondingly, which is also temperature dependent. At the temperature lower than 200 K, the influence of strain is negligible, while at the temperature higher than 200 K, more phonon modes will be activated at a larger strain. The heat capacity is increased to some degree, however, the thermal conductivity increases firstly and then decreases with the strain. This can be ascribe to the enhanced Umklapp scattering among phonons and is consistent with the result of vibration entropy. [ABSTRACT FROM AUTHOR]

The microbiological transformation of the triterpene nigranoic acid (3,4-secocycloarta-4(28),24(Z)-diene-3,26-dioic acid) (1) to 3,4-secocycloarta-4(28),17(20),24(Z)-triene-7β-hydroxy-16β,26-lactone-3-oic acid (2) and 3,4-secocycloarta-4(28),17(20)(Z),24(Z)-triene-7β-hydroxy-16β-methoxy-3,26-dioic acid (3) by the freshwater fungus Dictyosporium heptasporum YMF1.01213 has been demonstrated. The structures of the biotransformation products were determined by spectroscopic and MS analyses. Compound 2, characterized by the presence of a formed C-16/C-26 ester bridge, provided a novel nine-membered lactone ring structural skeleton for 3,4-secocycloartane triterpenoid derivatives. In addition, Compounds 1–3 exhibited weak anti-HIV activity in vitro. Compounds 2 and 3 were reported for the first time as natural product derivatives. [ABSTRACT FROM AUTHOR]

Anti-apoptotic proteins such as BCL-2, BCL-XL and MCL-1 bind with pro-apoptotic proteins to induce apoptosis mechanism. BCL-2 family proteins are key regulators of apoptosis process. Over expression of these anti-apoptotic proteins lead to several cancers by preventing apoptosis. A number of studies revealed that ginseng derivatives reduce tumor growth. Ginseng, the most valuable medicinal herb found in eastern Asia belongs to Araliaceae family. In this study, docking simulations were performed for anti-apoptotic proteins with several ginsenosides from Panax ginseng. Our finding shows ginsenosides Rf, Rg1, Rg3 and Rh2 have more binding affinity with BCL-2, BCL-XL and MCL-1 and other ginsenosides also interact with each anti-apoptotic proteins. Therefore, ginseng derivatives represent a novel class of potent inhibitors and could be used for cancer chemotherapy. [ABSTRACT FROM AUTHOR]

Objective. Few studies have assessed the diagnostic efficacy of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) and/or trucut biopsy (TCB) in patients with rectal and perirectal lesions. We aimed to evaluate the diagnostic utility of EUS-FNA and/or TCB in patients with rectal and perirectal lesions. We also assessed their influence on the management and clinical course of these patients. Material and methods. We performed EUS-FNA and/or TCB in 11 consecutive patients (4 men and 7 women, 33-69 years) with rectal and perirectal lesions for whom conventional diagnostic tools could not provide definitive diagnoses. Patients with definite intraluminal cancer were excluded. Results. The 11 patients underwent 12 procedures, with 9 being EUS-FNA alone and 3 being EUS-FNA and TCB. Seven patients had rectal lesions and four had perirectal lesions. Initial EUS-FNA and/or TCB established a diagnosis of malignancy in five patients and of benign lesions in four. EUS-FNA plus TCB confirmed malignant lymphoma after diagnostic failure of initial EUS-FNA in one patient. In one other patient with suspicious secondary linitis plastica, EUS-FNA could not establish a definitive diagnosis. Correct diagnoses were obtained in 10 out of 11 patients who underwent EUS-FNA and/or TCB. EUS-FNA and/or TCB changed clinical courses, which included avoidance of unnecessary surgeries, having a chance of anal sphincter-saving surgeries, and timely administration of chemotherapy. No serious complications related to the use of EUS-FNA or TCB were evident. Conclusion. EUS-FNA and/or TCB are useful in the diagnostic evaluation of and appropriate therapeutic plan in patients with rectal and perirectal lesions. [ABSTRACT FROM AUTHOR]

We investigated the tumor suppressor activity and regulatory mechanism of 15-hydroxyprostaglandin dehydrogenase (15-PGDH) in gastric cancer; 15-PGDH expression was lost in 70.1%% of malignant human gastric tissues, but was preserved in normal and metaplastic gastritis. KATO III and SNU-719 cells were transfected with pcDNA3.1-empty vector or an expression vector encoding wild-type 15-PGDH. In TUNEL assays apoptotic cell numbers were increased in KATO-PGDH-WT cells compared with control. We found that EGFR and ERK1/2 inhibitors clearly increased the expression of 15-PGDH in KATO III cells. Our findings demonstrate both downregulation and a tumor suppressor activity of 15-PGDH in gastric cancer. [ABSTRACT FROM AUTHOR]

Objective. Recent studies have suggested that the clinical characteristics and genetic background of Crohn's disease (CD) patients differ between Asian and Caucasian individuals. However, the clinical features and course of CD in Asian patients remain unclear. Therefore, we investigated the clinical features and long-term prognosis of CD in a Korean population. Material and methods. We retrospectively analyzed 278 Korean patients with CD first diagnosed at the Asan Medical Center between March 1991 and February 2007. Results. The male-to-female ratio was 2.2:1 and the median age at diagnosis was 23 years. The median duration of follow-up was 71 months (range, 1–210 months). At diagnosis, 187 patients (67.3%) had disease in both small bowel and colon, 68 (24.4%) had isolated small bowel disease, and 23 (8.3%) had isolated colonic disease. The number of patients with stricturing or penetrating behavior as defined by the Montreal classification increased from 87 (31.3%) at diagnosis to 141 (50.7%) at final evaluation. One hundred and thirty patients (46.8%) experienced perianal fistulas before and/or after diagnosis of CD. A total of 71 patients (25.5%) underwent intestinal resection and the cumulative probability of intestinal resection after 1, 5, and 10 years was 15.5%, 25.0%, and 32.8%, respectively. Conclusions. Korean CD patients differed from Western patients in gender distribution, disease location, and perianal fistula occurrence. Korean CD patients may also have better clinical courses than Western patients, as indicated by the lower intestinal resection rate. [ABSTRACT FROM AUTHOR]

Efficient diazaflourene-based two-photon absorbing dyes for two-photon induced photopolymerization (TPP) have been synthesized. Their linear optical properties display a slight bathochromic shift with increasing branches. The chromophores give rise to a blue emission which is useful for two-photon lithographic microfabrication. Their TPA cross-section (σ2) values evaluated by 100 femtosecond pulsed laser are found to be increased with the number of branches; 570 GM (760 nm) for dibranched diazafluorene (1) and 820 GM (760 nm) for tribranched diazafluorene (2). By using the resulting TPA chromophores we have succeeded to fabricate three-dimensional pattern with lattice structure. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article about intramedullary spinal cord metastasis of acute lymphoblastic leukemia, which appeared in the previous issue.