从“障塞”一词看海上丝路的起始年代

针对 2 0 0 1年“海上丝绸之路与南方大港学术研讨会”上 ,许多学者认为《汉书·地理志》中“日南障塞”的“障塞”是军事要塞、军事屏障 ,并据此推导出海上丝绸之路徐闻开港时间是汉武帝元鼎六年 (公元前 1 1 1年 )的观点 ,认为 :“障塞”只是一个普通的动词 ,是阻塞不通的意思 ;徐闻的开港时间也不是元鼎六年 ,而是元鼎六年之后、汉元帝之前 ,即大约公元前 1 1 0年—公元前

Science Letters:Model for cascading failures in congested Internet

Cascading failures often occur in congested networks such as the Internet. A cascading failure can be described as a three-phase process： generation, diffusion, and dissipation of the congestion. In this account, we present a function that represents the extent of congestion on a given node. This approach is different from existing fimctions based on betweenness centrality. By introducing the concept of ＇delay time＇, we designate an intergradation between permanent removal and nonremoval. We also construct an evaluation fimction of network efficiency, based on congestion, which measures the damage caused by cascading failures. Finally, we investigate the effects of network structure and size, delay time, processing ability and packet generation speed on congestion propagation. Also, we uncover the relationship between the cascade dynamics and some properties of the network such as structure and size.

Analysis of ileal sodium/bile acid cotransporter and related nuclear receptor genes in a family with multiple cases of idiopathic bile acid malabsorption

The etiology of most cases of idiopathic bile acid malabsorption （IBAH） is unknown. In this study, a Swedish family with bile acid malabsorption in three consecutive generations was screened for mutations in the ileal apical sodium-bile acid cotransporter gene （ASBT; gene symbol, SLC10A2） and in the genes for several of the nuclear receptors known to be important for ASBT expression： the farnesoid X receptor （FXR） and peroxisome proliferator activated receptor alpha （PPARα）. The patients presented with a clinical history of idiopathic chronic watery diarrhea, which was responsive to cholestyramine treatment and consistent with IBAH. Bile acid absorption was determined using ^75Se-homocholic acid taurine （SeHCAT）; bile acid synthesis was estimated by measuring the plasma levels of 7α-hydroxy-4-cholesten-3-one （C4）. The ASBT, FXR, and PPARα genes in the affected and unaffected family members were analyzed using single stranded conformation polymorphism （SSCP）, denaturing HPLC, and direct sequencing. No ASBT mutations were identified and the ASBT gene did not segregate with the bile acid malabsorption phenotype. Similarly, no mutations or polymorphisms were identified in the FXR or PPARα genes associated with the bile acid malabsorption phenotype. These studies indicate that the intestinal bile acid malabsorption in these patients cannot be attributed to defects in ASBT. In the absence of apparent ileal disease, alternative explanations such as accelerated transit through the small intestine may be responsible for the IBAM.

Treatment of gastric outlet and duodenal obstructions with uncovered expandable metal stents

AIM:To investigate and evaluate the technical feasibility and clinical effectiveness of fluoroscopically guided peroral uncovered expandable metal stent placement to treat gastric outlet and duodenal obstructions. METHODS:Fifteen consecutive patients underwent peroral placement of Wallstent^(TM)Enteral Endoprosthesis to treat gastric outlet and duodenal obstructions(14 malignant,1 benign).All procedures were completed under fluoroscopic guidance without endoscopic assistance.Follow-up was completed until the patients died or were lost,and the clinical outcomes were analyzed. RESULTS:The technique success rate was 100%,and the oral intake was maintained in 12 of 14 patients varying from 7 d to 270 d.Two patients remained unable to resume oral intake,although their stents were proven to be patent with the barium study.One patient with acute necrotizing pancreatitis underwent enteral stenting to treat intestinal obstruction,and nausea and vomiting disappeared.Ten patients died during the follow- up period,and their mean oral intake time was 50 d. No procedure-related complications occurred.Stent migration to the gastric antrum occurred in one patient 1 year after the procedure,a tumor grew at the proximal end of the stent in another patient 38 d post-stent insertion. CONCLUSION:Fluoroscopically guided peroral metal stent implantation is a safe and effective method to treat malignant gastrointestinal obstructions,and complications can be ignored based on our short-term study.Indications for this procedure should be discreetly considered because a few patients may not benefit from gastrointestinal insertion,but some benign gastrointestinal obstructions can be treated using this procedure.

Fault diagnosis method of train control RBC system based on KPCA-SOM network

Radio block center(RBC)system is the core equipment of China train control system-3(CTCS-3).Now,the fault analysis of RBC system mainly depends on manual work,and the diagnostic results are inaccurate and inefficient.Therefore,the intelligent fault diagnosis method of RBC system based on one-hot model,kernel principal component analysis(KPCA)and self-organizing map(SOM)network was proposed.Firstly,the fault document matrix based on one-hot model was constructed by the fault feature lexicon selected manually and fault tracking record table.Secondly,the KPCA method was used to reduce the dimension and noise of the fault document matrix to avoid information redundancy.Finally,the processed data were input into the SOM network to train the KPCA-SOM fault classification model.Compared with back propagation(BP)neural network algorithm and SOM network algorithm,common fault patterns of train control RBC system can be effectively distinguished by KPCA-SOM intelligent diagnosis model,and the accuracy and processing efficiency are further improved.

Difficulties Linked to Hebrew Language Among Immigrants in Israel

The present study examines language barriers experienced by Ethiopian women in Netanya, Israel. It aims at providing data on both the existing literature on the subject as well as on the empirical results based on answers to a questionnaire. In particular, this paper looks into the difficulties linked to the Hebrew language with regard to the integration of these women, which is regarded as a hindrance towards a better and thorough integration in the city of Netanya. This language barrier affects all aspects of their daily life particularly in the fields of education and employment. This investigation into language barriers is seen through the eyes of one Ethiopian woman within her three-generation family. In addition to the disadvantage linked to language, this survey points out the discrimination which this minority population, especially women faces.

Acute inferior ST-segment elevation myocardial infarction cryptogenic stroke caused by a paradoxical embolism with pulmonary embolism and previous a concomitant

A 61-year-old woman was hospitalized for a chief complaint of sudden chest tightness with sweating for two hours. The chest tightness and sweating occurred suddenly and without remission after a morning stool. Electrocardiography showed a complete atrioventricular （AV） block and arc-like elevation of the ST-segment in leads Ⅱ, Ⅲ, AVF, V7-V9, and V3R-V5R, at about 0.05-0. 15 mV. After being administered 1 mg of atropine in the emergency room （ER）, the patient was admitted to the cardiology department. The patient had been found in a cyanotic state two years previously, but did not receive any treatment; she was diagnosed with a transient ischemic attack （TIA） 1.5 years previously because of limb dyskinesia accompanied by slurred speech.

Duodenal obstruction after successful embolization for duodenal diverticular hemorrhage: A case report

We present a 69-year-old woman with a duodenal obstruction after successful selective transcatheter arterial embolization (TAE) for a duodenal diverticular hemorrhage. Two weeks after TAE, the patient showed abrupt symptoms of duodenal obstruction. Resolving hematomas after successful selective transcatheter arterial embolization should be thoroughly observed because they might result in duodenal fibrotic encasement featuring inflammatory duodenal wall thickening, duodenal deformity, dysmotility, and fi nally obstruction.

Optimization of Telephone Occlusion Method on Urban Rail Transit in Shanghai

Telephone occlusion method is a backup manual occlusion method during an urban rail transit signal equipment failure, which ensures that metro operated safely and orderly. Through the results of several telephone occlusion exercises, find out the shortcomings oftclcphone occlusion method and optimizing it.

Prognostic analysis and complications of traumatic carotid cavernous fistulas after treatment with detachable balloon and/or coil embolization

Objective: To explore the causes of the formation of traumatic carotid-cavernous fistulas and the therapeutic effect of detachable balloon and/or coil embolization and the prevention of its complications. Methods: From October, 1992 to March, 2002, 17 patients with traumatic carotid-cavernous fistulas were treated with detachable balloon and/or coil embolization in our hospital. The clinical data and imaging features of CT, MR and selective angiogram of these patients were analyzed. Results: One week after treatment with embolization, the clinical symptoms of the 17 patients were remitted, and optic cacophony, nystagmus, exophthalmos and dropsy of conjunctiva disappeared. Two patients manifested surgical complications, one patient died. Sixteen patients survived. They were all followed up for more than 2 years, which showed one patient had handicap in movement, and in one patient the signs and symptoms of traumatic carotid-cavernous fistulas reoccurred 2 months after treatment. Conclusions: The detachable balloon and/or coil embolization is safe and reliable. It is a good method to treat traumatic carotid-cavernous fistulas.

The Determination of the Optimal Buffer Size Based on the Control Point Policy

The failure prone production systems are examined. For the hybrid systems, the failure of machines is unavoidable. By introduced the idea of purchasing extra capacity to the system, a so-call blockage hedging point is obtained. Meanwhile, a near-optimal method is presented to determine the optimal buffer sizes. The continuous flow model of the unreliable manufacturing systems is considered and the control point policy is involved in. Numerical results not only testify the method and show us its application but also to some extent show the impact of the machines＇ failure rate on the optimal buffer size.

Retrospective study on the endovascular embolization for traumatic carotid cavernous fistula

Objective： To retrospectively analyze 95 cases of traumatic carotid cavernous fistula treated by endovascular embolization. Methods： From January 1994 to December 2008, 95 patients with traumatic carotid cavernous fistula were treated in our hospital. All patients received selective cerebral angiography through femoral artery catheterization. Accordingly, 89 cases were treated by detachable balloon embolization, 5 by platinum microcoils and 1 by coveredstem, respectively. Results： In the study, 61 cases achieved successful balloon embolization at the first time. Fifty-six cases had multiple balloons due to the big fistula. Nine cases received balloon embolization twice. But among the 5 patients treated with platinum microcoils, one developed slight brainstem ischemia. After operation the patient had herniparesis and swallow difficulty, but gradually recovered 3 months later. No neurological deficits were observed in other cases. All the cases recovered. Eighty-five cases were followed up for 1-15 years and no recurrence was found. Conclusions： The endovascular embolization for traumatic carotid cavernous fistula is minimally invasive, safe, effective and reliable. The detachable balloon embolization is the first choice in the treatment of TCCF.