乳头柱状球囊扩张术时间的选择及其对胆总管结石疗效的影响

目的 探讨乳头柱状球囊扩张术(EPBD)治疗时间的选择及其对内镜逆行胰胆管造影(ERCP)治疗胆总管结石疗效的影响。方法 选取2017年1月至2022年12月于青岛市胶州中心医院住院治疗的108例胆总管结石患者作为研究对象,将EPBD持续时间为30 s的患者列入30 s组,将EPBD持续时间为60 s的患者列入60 s组,两组各54例。两组均行ERCP取石,记录两组性别、年龄、憩室旁乳头比率、结石直径、胆管直径等一般资料,一次净石率、机械碎石率、术中活动性出血率、手术时间、住院时间等取石情况,穿孔、术后出血、急性胰腺炎、高淀粉酶血症等术后并发症发生情况。比较两组患者的临床资料,建立不同EPBD持续时间ERCP治疗胆总管结石的多准则决策模型。结果 60 s组患者的一次净石率高于30 s组(P<0.05),机械碎石率、住院时间、住院费用、术后并发症的发生率均低于30 s组(P<0.05)。应用Meta分析方法分别合并两组患者的风险-效益值发现,60 s组的效益平均值、风险平均值均高于30 s组,且效益-风险总值68高于30 s组的58;60 s组优于30 s组的概率为100%。结论 选择EPBD时间维持在60 s可有效提高一次净石率,降低机械碎石率、住院时间及住院费用,减少急性胰腺炎和高淀粉酶血症的发生。

论威廉·詹姆斯的审美时间哲学——从意识流的域状构成与艺术作品空间构成整体性之关系说起

威廉·詹姆斯对原发实践活动的完整把握是其实用主义美学思想的根基,他还尤为擅长描述与分析主客不分离领域之中的审美现象。他既强调审美生活受意义寻求驱动而具有的当下即席兴发的时机化特性,着重分析其原生、偶在却必然的鲜活状态;又创造性地从意识流或时间意识构成的角度,探究了审美生活流畅地兴发的域状特性。他认为,只有在这一前提下,才会把艺术作品或其空间构成称为整体性的。詹姆斯的审美时间哲学在同时确保审美生活的原发性状态及艺术作品空间构成的完整性上,提供了一个描述审美生活的"时-空语法"的卓著范例。当然,詹姆斯的这一观念还只是潜隐的、不自觉的、零散的,本文对此也多有阐发、修正与补充。

德、法文学领域“古今之争”辨析——以现代性时间观念为视野

德、法文学领域的"古今之争"体现了两国知识界在现代化转型期对于时间问题的关切。由于历史、传统、经济、文化及地域等多方面差异,法国知识界多信奉"线性时间观"及与之伴生的乐观"历史进步论",德国知识界则对"线性时间观"态度谨慎,倾向于一种杂糅了"线性时间观"和"轮状时间观"的"文化时间观"。这种"向后看"的文化自觉不仅使德国启蒙界在时间观念上独树一帜,更导致其在现代化转型路径的选择中走上了一条"文化现代化"优于"社会现代化"的独特路径。

DIGITAL PWM OF AC-AC MATRIX CONVERTER BASED ON OUTPUT-VOLTAGE ERROR FUNCTION

Based on the output-voltage error function, a novel time discrete modulation technique is proposed for matrix converters （MCs） and time-discrete difference equations of a MC circuit are derived. Switch states of MC are obtained when the output voltage error function is minimized, thus the optimum combination of switch states is derived for the closed-loop control of MC. Meanwhile, advantages of the least calculation workload, the simple process, and the convenient for implementation are brought while switch states are described as space vectors in the α-β coordination system. Simulation and experimental results demonstrate the validity of the time-discrete modulation technique and the feasibility of the control approach.

Application of high temperature heat pipe in hypersonic vehicles thermal protection

In order to develop further the application of high temperature heat pipe in hypersonic vehicles thermal protection, the principles and characteristics of high temperature heat pipe used in hypersonic vehicles thermal protection were introduced. The methods of numerical simulation, theory analysis and experiment research were utilized to analyze the frozen start-up and steady state characteristic of the heat pipe as well as the machining improvement for fabricating irregularly shaped heat pipe which is suitable for leading edge of hypersonic vehicles. The results indicate that the frozen start-up time of heat pipe is long （10 min） and there exists large temperature difference along the heat pipe （47 ℃/cm）, but the heat pipe can reduce the temperature in stagnation area of hypersonic vehicles from 1 926 to 982 ℃ and work normally during 1 000-1 200℃. How to improve the maximum heat transfer capability and reduce the time needed for start-up from frozen state of the heat pipe by optimizing thermostructure such as designing of a novel wick with high performance is the key point in hypersonic vehicles thermal protection of heat pipe.

State Space-Time and Four States of Universe

All things in the universe possess a state and characteristics of state, resultantly in presence of space-time, which is perceived by human beings. An outlook of space-time is shaped in human by perceiving the existence and change of objects. The state space is all state characteristics exhibited in objects whilst the state time refers to the duration of an object＇s state. The time is a spatial property and not an independent dimension. The state space-time is a unity of internal and external space-time. The internal space-time is stemmed from the overall internal forces and internal energies and is a covert space-time. The external space-time refers to a space-time manifested by the external characteristics and movement of an object and is an overt space-time. In physics, there are four kinds of forces and four state space-times： bonding force and three-dimensional space-time; strong interaction of exchangeable n meson and two-dimensional space-time; quark confinement and one-dimensional space-time; and weak interaction and zero-dimensional space-time. The universe is constituted by dissimilar state space-times. Newton space-time is a three-dimensional state space-time; Einstein＇s theory of relativity is a two-dimensional state space-time. Newton and Einstein were different observers. Temporal and spatial perception of human is dependent upon human＇s intemal energy and quality. Through Qigong exercises, the human is able to enter the three-dimensional, two-dimensional, one-dimensional and zero-dimensional space-times. The relativity theory of human body will solve the time problems at the interplanetary voyage of astronauts.

Multiverse and the Time State

This article is not inspired by any religion or quantum many-worlds interpretation. The mathematics of multiverse is presented here. The mass operator was introduced earlier by Alnobani. This operator is used here to deduce the time state. It is found that time has four states and those four states are orthogonal. Time is the constitution of any verse. Time has direction. Every orthogonal direction of time belongs to a verse. Past and future belong to opposite directions of time and they are arbitrary. Other verses are there by their own and not a probabilities of any other verse and if any similarity it is only a coincidence. Among applications of this thesis is travelling through groups of galaxies, or more or less.

Effect of ginger on gastric motility and symptoms of functional dyspepsia

AIM:To evaluate the effects of ginger on gastric motility and emptying,abdominal symptoms,and hormones that influence motility in dyspepsia.METHODS:Eleven patients with functional dyspepsia were studied twice in a randomized double-blind manner.After an 8-h fast,the patients ingested three capsules that contained ginger(total 1.2 g) or placebo,followed after 1 h by 500 mL low-nutrient soup.Antral area,fundus area and diameter,and the frequency of antral contractions were measured using ultrasound at frequent intervals,and the gastric half-emptying time was calculated from the change in antral area.Gastrointestinal sensations and appetite were scored using visual analog questionnaires,and blood was taken for measurement of plasma glucagon-like peptide-1(GLP-1),motilin and ghrelin concentrations,at intervals throughout the study.RESULTS:Gastric emptying was more rapid after ginger than placebo [median(range) half-emptying time 12.3(8.5-17.0) min after ginger,16.1(8.3-22.6) min after placebo,P ≤ 0.05].There was a trend for more antral contractions(P = 0.06),but fundus dimensions and gastrointestinal symptoms did not differ,nor did serum concentrations of GLP-1,motilin and ghrelin.CONCLUSION:Ginger stimulated gastric emptying and antral contractions in patients with functional dyspepsia,but had no impact on gastrointestinal symptoms or gut peptides.

A Development Study on the Ordering Distribution of Temporal Adverbial Clauses by Chinese EFL Learners Based on Dependency Treebank

Temporal adverbial clause is an important language structure and exhibits different features in English and Chinese,which brings about difficulties for Chinese EFL learners.Based on the theory of Dependency Grammar,the study attempts to investigate the ordering distribution of temporal adverbial clauses by Chinese EFL learners at the beginning,intermediate and advanced levels.The results show that:1)Chinese EFL learners at different proficiencies tend to precede temporal adverbial clause to main clause.With the increase of proficiency,the postposition of temporal adverbial clauses by learners increases and is approaching to the ordering preference of target language.2)The ordering distribution of subordinators for temporal adverbial clauses by Chinese EFL learners is consistent with native English,showing a tendency of 100%preposition,which ascribes to the high frequency and salience of subordinators in English.3)MDD is one of the significant motivations that cause the preference of prepositional temporal adverbial clauses by Chinese EFL learners.As a kind of natural language,interlanguage has a unique cognitive mechanism which distinguishes from both native and target language.This study provides a more comprehensive theoretical reference for learners at different proficiencies to understand and learn temporal adverbial clauses,as well as data support from empirical research for language teaching.

Temporal Characteristics of the Queueing Process ot 3uffer-aided Wireless Communications

Due to the fading property of wireless channels, the instant transmission capability of a fading channel, i.e., the instantaneous channel capacity, will change randomly along time. Usually, a finite size buffer is needed at the transmitter to match instant channel capacity with the source data stream. This paper is focused on the queuing process in the buffer. The temporal characteristics of the queueing process in the buffer are investigated, for a buffer-aided communication over block Rayleigh fading channel, in the low signal- to-noise ratio regime. Particularly, the average absorbing time for the buffer to transfer from empty state to overflow sate and from overflow state to empty state, as well as the stable working time in which neither buffer empty nor buffer overflow happens are derived. Theoretical and numerical results show that increasing the buffer size and traffic load properly will improve the efficiency of the transmission.

Remaining Useful Life Prediction of Aeroengine Based on Principal Component Analysis and One-Dimensional Convolutional Neural Network

In order to directly construct the mapping between multiple state parameters and remaining useful life(RUL),and reduce the interference of random error on prediction accuracy,a RUL prediction model of aeroengine based on principal component analysis(PCA)and one-dimensional convolution neural network(1D-CNN)is proposed in this paper.Firstly,multiple state parameters corresponding to massive cycles of aeroengine are collected and brought into PCA for dimensionality reduction,and principal components are extracted for further time series prediction.Secondly,the 1D-CNN model is constructed to directly study the mapping between principal components and RUL.Multiple convolution and pooling operations are applied for deep feature extraction,and the end-to-end RUL prediction of aeroengine can be realized.Experimental results show that the most effective principal component from the multiple state parameters can be obtained by PCA,and the long time series of multiple state parameters can be directly mapped to RUL by 1D-CNN,so as to improve the efficiency and accuracy of RUL prediction.Compared with other traditional models,the proposed method also has lower prediction error and better robustness.

Entanglement Dynamics of Two Qubits Coupled to a Noise Environment

We study the time evolution of two two-state systems （two qubits） initially in the pure entangled states or the maximally entangled mixed states interacting with the individual environmental noise. It is shown that due to environment noise, all quantum entangled states are very fragile and become a classical mixed state in a short-time limit. But the environment can affect entanglement in very different ways. The type of decoherence process for certain entangled states belongs to amplitude damping, while the others belong to dephasing decoherenee.

Effects of Snow Cover on Ground Thermal Regime： A Case Study in Heilongjiang Province of China

The important effects of snow cover to ground thermal decades. In the most of previous research, the effects were usually regime has received much attention of scholars during the past few evaluated through the numerical models and many important results are found. However, less examples and insufficient data based on field measurements are available to show natural cases. In the present work, a typical case study in Mohe and Beijicun meteorological stations, which both are located in the most northern tip of China, is given to show the effects of snow cover on the ground thermal regime. The spatial （the ground profile） and time series analysis in the extremely snowy winter of 2012-2013 in Heilongjiang Province are also performed by contrast with those in the winter of 2011-2012 based on the measured data collected by 63 meteorological stations, Our results illustrate the positive （warmer） effect of snow cover on the ground temperature （GT） on the daily basis, the highest difference between GT and daily mean air temperature （DGAT） is as high as 32.35℃. Moreover, by the lag time analysis method it is found that the response time of GT from 0 cm to 20 cm ground depth to the alternate change of snow depth has 10 days lag, while at 40 cm depth the response of DGAT is not significant. This result is different from the previous research by modeling, in which the resnonse denth of ground to the alteration of snow depth is far more than 40 cm.

Relationship between wave steepness and wave age in the course of wind wave growth

It is traditionally assumed that the relationship between wave steepness and wave age is inde- pendent of the wind wave growth state. In fact, the traditional relationship can not describe the whole course of wind wave growth. This paper assumes that the relationship between wave steepness and wave age changes with the variety of dimensionless fetch. Based on the relationship proposed by Hou and Wen (1990), a new relation- ship in the course of wind wave growth is revealed. Comparisons between the present study and other previous relationships show that this new relationship explains better the observations than the other existing relationships. In the case of small fetch, wave age value increases more quickly than other models while it is in opposition to that in the case of large fetch. The result in present paper can clearly reflect the whole course of wind wave growth, it is an improvement for traditional results.Key words: wave steepness, wave age, relationship between wave steepness and wave age

Rotation Thromboelastography for Assessment of Hypercoagulation and Thrombosis in Patients with Cardiovascular Diseases

Hypercoagulation is not detected in clinical practice with routinely performed blood coagulation tests. More advanced laboratory analyses to detect or monitor hypercoagulation have not yet been introduced into routine clinical management. Thromboelastography assesses the influence of plasma factors and platelets during all phases of haemostasis, thus permits evaluation of hypo- and hyper- coagulation status. This prospective study included assessment of 35 patients with thrombotic complications （II-nd group）, compared with 34 healthy controls （I-st group）. Haemostasis was analyzed with routine clotting tests： protrombin time （PT）, activated partial thromboplastin time （APTT）, fibrinogen, platelets and rotation thromboelastography （ROTEM~） with measuring time to 20 min. All data are presented as mean and standard deviation （SD）. Statistical comparisons of samples were performed by student＇s t-test. The sensitivity, specificity, positive and negative predictive value of the parameters was calculated by using the receiver operator characteristic （ROC） curves for two groups. There was significant difference （P 〈 0.05） observed in the parameters of ROTEM： clot formation time （CFT）, a-angle, maximum clot firmness （MCF） and thrombodynamic potential index （TPI） in the patient＇s population compared to the healthy controls. No significant difference was observed in CT （ROTEM） and routine coagulation tests when the two groups were compared. Rotation thromboelastography analysis demonstrated to be a reliable method for diagnosis of hypercoagulable state.

Research on the Summer Drought in Chongqing Using MODIS-EVI Time Series Data

MODIS-EVI time series data from 2000 to 2009 in Chongqing were selected for this study.By the use of best index slope extraction （BISE） method for cloud elimination,analysis on the change vector of EVI time series data were conducted to investigate the EVI response on drought; then,four typical regions were selected to study the relationship between precipitation,temperature and EVI when the sever drought occurred in 2006; finally,based on the time series of vegetation condition index （VCI） and precipitation abnormity percentage,the temporal and spatial distributions of drought were studied.The results showed that,the EVI value of the summer in 2006 was significantly lower than the average EVI at the corresponding period of the other years in Chongqing.In addition,summer drought occurred mainly during the hot and dry weather.Except the southeast area,most of the other regions in Chongqing were all under severe drought.

Analysis of the Correlation between Seed-setting Characters and Seed Investigation Time in Rice

With super hybrid rice cultivar Y Liangyou 1 as the experimental material, seed-setting rate, abortive grain rate, empty grain rate and 1 000-seed weight were investigated for continuous 10 days since the first day post-harvest to reveal the correlation between differences in seed-setting characters of rice and seed investiga- tion time. The results indicated that seed-setting rate, abortive grain rate, empty grain rate and 1 000-seed weight varied at different seed investigation time. With the postponement of seed investigation, seed-setting rate and 1 000-seed weight showed downward trends, abortive grain rate showed an upward trend, while empty grain rate exhibited a significant correlation with seed investigation time. Seed-setting rate, abortive grain rate and 1 000-seed weight exhibited no significant differences within the first three days after the harvest; since day 4, seed-setting rate and 1000-seed weight declined remarkably, while abortive grain rate increased signifi- cantly. Based on the correlation between seed-setting characters of rice and seed investigation time, the analysis of seed-setting characters of rice and other cereal crops should be completed within the first three days after the harvest, thereby im- proving the accuracy of relative conclusion.

Travel time prediction model of freeway based on gradient boosting decision tree

To investigate the travel time prediction method of the freeway, a model based on the gradient boosting decision tree (GBDT) is proposed. Eleven variables (namely, travel time in current period T i , traffic flow in current period Q i , speed in current period V i , density in current period K i , the number of vehicles in current period N i , occupancy in current period R i , traffic state parameter in current period X i , travel time in previous time period T i -1 , etc.) are selected to predict the travel time for 10 min ahead in the proposed model. Data obtained from VISSIM simulation is used to train and test the model. The results demonstrate that the prediction error of the GBDT model is smaller than those of the back propagation (BP) neural network model and the support vector machine (SVM) model. Travel time in current period T i is the most important variable among all variables in the GBDT model. The GBDT model can produce more accurate prediction results and mine the hidden nonlinear relationships deeply between variables and the predicted travel time.

ERCP for the treatment of bile leak after partial hepatectomy and fenestration for symptomatic polycystic liver disease

AIM: To describe endoscopic treatment of bile leaks in these patients and to identify risk factors in these patients which can predict the development of bile leaks. METHODS: Retrospective case-control study examining consecutive patients who underwent partial hepatectomy for polycystic liver disease (PLD) and developed a postoperative bile leak managed endoscopically over a ten year period. Each case was matched with two controls with PLD who did not develop a postoperative bile leak. RESULTS: Ten cases underwent partial hepatectomy with fenestration for symptoms including abdominal distention, pain and nausea. Endoscopic retrograde cholangiopancreatography (ERCP) showed anatomic abnormalities in 1 case. A biliary sphincterotomy was performed in 4 cases. A plastic biliary stent was placed with the proximal end at the site of the leak in 9 cases; in 1 case two stents were placed. The overall success rate of ERCP to manage the leak was 90%. There were no significant differences in age, gender, comorbidities, duration of symptoms, history of previous surgery or type of surgery performed between cases and controls. CONCLUSION: ERCP with stent placement is safe and effective for management of post-hepatectomy bile leak in patients with PLD.

Ultrafast Excited State Dynamics of t^rans-4-Aminoazobenzene Studied by Femtosecond Transient Absorption Spectroscopy

The ultrafast excited state dynamics of trans-4-aminoazobenzene （trans-4-AAB） in ethanol was investigated by femtosecond transient absorption spectroscopy. After being excited to the S2 state by 400 nm, trans-4-AAB decays from the S2 state to the hot S1 state by internal conversion with time constant of -70 fs. The photoisomerization through inversion mechanism on the S1 potential energy surface and the internal conversion from the S1 state to the hot So state are observed, respectively. The average timescale of these two decay pathways is -0.7 ps. And the vibrational cooling of the hot So state of cis- and trans-4- AAB occur with time constants of -4 and N13 ps, respectively. Furthermore, the ultrafast intersystem crossing process are also observed. The timescale of intersystem crossing from the S2 state to the T4 state is about 480 ps while from the S1 state to the T2 state is -180 ps.