2,059 research outputs found

    Analysis of Mainland China’s International Air Cargo Network: Status Quo and Challenges

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    Based on air cargo import and export statistics of China Customs, the international air cargo network structure and its flow characteristics in mainland China were studied in this paper. Overall development trends and flow distribution of international air cargo in mainland China were analysed. The major air cargo import and export countries (regions), the main categories of commodities, and the major customs and hub airports were identified. Through our study, a relatively complete view of international air cargo network in mainland China was constructed, in which the major flight routes linking destinations and sources of international air cargo as well as the categories and amounts of air cargo could be revealed. This paper also includes challenges to the further development of mainland China\u27s international air cargo, and proposals to meet these challenges

    Ammonium 2-(2,4-dichloro­phen­oxy)acetate hemihydrate

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    The title compound, NH4 +·C8H7Cl2O6 −·0.5H2O, was prepared by the reaction of 2-(2,4-dichloro­phen­oxy)­acetic acid and ammonia in water at 367 K. The mol­ecular structure and packing are stabilized by N—H⋯O and O—H⋯O inter­molecular hydrogen-bond inter­actions

    Quantum transport through a double Aharonov-Bohm-interferometer in the presence of Andreev reflection

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    Quantum transport through a double Aharonov-Bohm-interferometer in the presence of Andreev reflection is investigated in terms of the nonequilibrium Green function method with which the reflection current is obtained. Tunable Andreev reflection probabilities depending on the interdot coupling strength and magnetic flux as well are analysised in detail. It is found that the oscillation period of the reflection probability with respect to the magnetic flux for the double interferometer depends linearly on the ratio of two parts magnetic fluxes n, i.e. 2(n+1)pi, while that of a single interferometer is 2pi. The coupling strength not only affects the height and the linewidth of Andreev reflection current peaks vs gate votage but also shifts the peak positions. It is furthermore demonstrated that the Andreev reflection current peaks can be tuned by the magnetic fluxes.Comment: 13 pages, 12 figur

    人造血管在血液透析造瘘的应用及护理

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    Objective: To study the application of artificial blood vessels to build alternative standard arteriovenous fistula blood vessels for hemodialysis maintenance nursing. Methods: 17 cases of patients underwent artificial blood vessel transplantation, material for ptfe (PTEE), 30 cm in length, inner diameter 5mm, from 2012 to 2013 in Jinan military region general hospital. Artificial blood vessel transplantation is more operated on brachial vein, cephalic vein, median cubital vein and basilic vein. When the anastomosis among artificial blood vessels and brachial artery and vein anastomosis was established, the arterial end was on the inner side. When the anastomosis among brachial vein, median cubital vein and basilic vein was established, the arterial end was on the outside for the extension of vascular access. Results: 15 cases have hemodialysis after two months’ treatment, 1 case have artificial blood vessel fistula after swelling for 4 months, infection of thrombosis occurred one month after the operation in 1 case. Conclusion: Artificial blood vessel show good biocompatibility, high long-term patency rate, blood flow, and convenient puncture point. It builds the “lifeline” for the patients who are unable to establish a good vascular access. It is of great significance to improve the management of artificial blood vessel fistula for maintenance hemodialysis patients.目的  研究应用人造血管造瘘替代标准动静脉血管维持血液透析的护理。方法  本院自2012—2013年对17例血液透析患者进行人造血管移植术,材料为聚四氟乙烯(PTEE)材料,长度30cm,内径5mm。人造血管移植术多选择与肱动脉和头静脉或肘正中静脉、贵要静脉U型吻合。人造血管与肱动脉和头静脉吻合时,动脉端在内侧。但肱动脉与肘正中静脉、贵要静脉吻合时,为延长有效性血管通路,动脉端则在外侧。结果  15例术后2个月成熟顺利实施血液透析,1例持续肿胀4个月后开始应用,1例术后1个月出现感染血栓形成。结论  人造血管具有生物相容性好、长期通畅率高、血流量大、穿刺方便、穿刺部位充足等优点,为自身血管条件差、无法建立良好血管通路的透析患者提供了可靠的血管通路,为维持性血液透析患者建立了“生命线”。加强透析过程中的人造血管内瘘管理对于维持透析患者良好的血管通路具有重要意义

    Atrial fibrillation episode status and incidence of coronary slow flow: A propensity score-matched analysis

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    BackgroundPrevious studies have shown that patients with a history of atrial fibrillation (AF) have a higher risk of developing coronary slow flow (CSF). However, whether AF episode status affects the incidence of CSF has not been confirmed. This study investigated the correlation between AF episode status and the incidence of CSF.MethodsWe enrolled patients with AF who underwent coronary angiography for symptoms of myocardial ischemia between January 1, 2017, and April 30, 2022, at our institution and classified them according to whether they had an episode of AF in the perioperative period. The outcomes were defined the occurrence of CSF overall and in each of the three coronary arteries. The analysis was repeated after adjusting the baseline information by the propensity score matching method in a 1:1 ratio.Results214 patients who met the inclusion and exclusion criteria were included in the study (AF episode group: 100 patients, AF non-episode group: 114 patients). Before matching, age, left atrial size, ejection fraction, heart rate, CSF incidence, and mean corrected thrombolysis in myocardial infarction frame counts were higher in patients with intraoperative AF episodes than in patients without episodes. To prevent the dependent variable (CSF incidence) from being confounded by confounding factors, we matched the two groups for age, left atrial size, and ejection fraction. In the logistic regression analysis, the incidence of CSF was significantly higher in the intraoperative AF episode group (P = 0.010, OR = 2.327, 95% CI: 1.226–4.416) than in the non-episode group.ConclusionIn patients with AF, AF episode status is significantly correlated with an increased overall incidence of CSF

    A case report of pulmonary hepatoid adenocarcinoma: promoting standardized diagnosis and treatment of the rare disease

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    ObjectiveTo investigate the clinical features, pathological characteristics, immunophenotype, differential diagnosis and prognosis of pulmonary hepatoid adenocarcinoma using a clinical case and literature report.MethodsWe analyzed the clinical presentation, histological pattern and immunohistochemistry of a case of primary hepatoid adenocarcinoma of the lung in April 2022. We also reviewed literature on hepatoid adenocarcinoma of the lung from PubMed database.ResultsThe patient was a 65-year-old male with smoking history, who was admitted to hospital with an enlarged axillary lymph node. The mass was round, hard, and grayish-white and grayish-yellow in color. Microscopically, it presented hepatocellular carcinoma-like and adenocarcinoma differentiation features, with abundant blood sinuses visible in the interstitium. Immunohistochemistry showed that the tumor cells were positive for hepatocyte markers, including AFP, TTF-1, CK7 and villin, and negative for CK5/6, CD56, GATA3, CEA and vimentin.ConclusionPulmonary hepatoid adenocarcinoma is a rare epithelial malignancy of primary origin in the lung with poor prognosis. Establishing the diagnosis relies mainly on the detection of hepatocellular structural morphology resembling hepatocellular carcinoma, and on clinicopathological and immunohistochemical testing to exclude diseases such as hepatocellular carcinoma. Combination treatment, mainly surgery, can prolong the survival of early-stage cases of the disease, whereas radiotherapy is mostly used for intermediate and advanced cases. Individualized treatment with molecular-targeted drugs and immunotherapy has shown different therapeutic effects for different patients. Further research is needed to better understand this rare clinical condition for the development and optimization of treatment strategies
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