lNTRODUCTlON

圖10為不同溫度下水蒸氣在發(fā)動(dòng)機(jī)內(nèi)流場(chǎng)中的分布, 通過對(duì)比可以發(fā)現(xiàn), 當(dāng)發(fā)動(dòng)機(jī)混合腔中注入的是高溫氣體時(shí), 有部分水流被加熱成為水蒸氣, 并進(jìn)入噴管, 在順壓梯度的作用下將其內(nèi)能轉(zhuǎn)化為兩相流的動(dòng)能, 從而提高了發(fā)動(dòng)機(jī)的推力. 在氣體質(zhì)量流率一定的情況下, 注入氣體的溫度越高, 生成的水蒸氣越多, 發(fā)動(dòng)機(jī)的推力、 比沖越大. 但是由于水的蒸發(fā)潛熱很大, 通過加熱氣體來(lái)提高發(fā)動(dòng)機(jī)性能的方式能量利用效率較低.

Gastric variceal (GV) hemorrhage leads to significant mortality in patients with portal hypertension.Although N-butyl-2-cyanoacrylate (NBC) has been widely used in the endoscopic hemostasis of portal hypertension, the early expulsion of NBC and the resultant hemorrhage is not uncommon[5]. Compared with conventional endoscopic injection, endoscopic ultrasound (EUS)-guided procedures in patients with GV bleeding demonstrated better diagnostic capability and clinical efficacy[6,7].

Herein, we report the successful management of GV hemorrhage secondary to LSPH using modified EUS-guided selective NBC injection.

CASE PRESENTATlON

Chief complaints

A 35-year-old man was referred to our hospital due to an upper GI hemorrhage.

History of present illness

A few hours before admission, the patient had no apparent reason for one occurrence of sudden vomiting of blood mixed with stomach contents and the amount was estimated to be about 50-100 mL.He denied melena and syncope.

History of past illness

All study participants, or their legal guardian, provided informed written consent prior to study enrollment.

Personal and family history

This patient had a 10-year smoking history (a pack per day) and has not quit smoking. He denied alcoholism and taking nonsteroidal anti-inflammatory drugs.

Physical examination

最后，還應(yīng)當(dāng)定期實(shí)施藥物手段，實(shí)現(xiàn)疫病的有效預(yù)防。應(yīng)當(dāng)在堅(jiān)持對(duì)飼養(yǎng)豬群進(jìn)行免疫接種的基礎(chǔ)上，還要牢牢把握豬傳染性胸膜肺炎的流行特征，著重在疫病爆發(fā)的高峰時(shí)期（如換季時(shí)節(jié)、仔豬斷奶時(shí)期等）進(jìn)行嚴(yán)格防控，依據(jù)科學(xué)標(biāo)準(zhǔn)適當(dāng)提升飼料的營(yíng)養(yǎng)性，并酌情在飼料中摻入保健藥物以起到良好的預(yù)防功效，最大限度提升豬群的免疫力與抗病能力。此外，一經(jīng)發(fā)現(xiàn)有生豬發(fā)病，則應(yīng)當(dāng)立刻將病豬進(jìn)行隔離，并依據(jù)其癥狀表現(xiàn)選擇有針對(duì)性藥物、敏感藥物進(jìn)行積極治療，以起到控制傳染源、避免傳播流行的作用。

After admission, physical examination revealed no abnormality except for 130/91 mmHg blood pressure.

Laboratory examinations

No apparent abnormalities were found in the emergency blood analysis.

Imaging examinations

Pancreatic diseases such as pancreatitis and pancreatic tumors are the most common etiology of LSPH[3,8]. The anatomical proximity between the splenic vein and the pancreas makes the splenic vein more susceptible to pancreatic diseases. When pancreatic disease obstructs the splenic vein flow, the pressure of the left portal vein system increases and blood flows retrogradely through the short and posterior gastric veins and the gastroepiploic veins, which would lead to GVs. In patients with acute pancreatitis,infected walled-off necrosis was one of the risk factors for LSPH and early anticoagulation could not wholly prevent its occurrence[8]. In this case, the patient had a history of SAP and infected pancreatic necrosis which may be responsible for his LSPH. About 20% of patients with portal hypertension may develop GVs[9], and although LSPH is a rare cause of upper GI hemorrhage, GV hemorrhage in patients with LSPH secondary to pancreatic disease is not uncommon. Liu[10] reported that about 15.3% of LSPH patients had complicated bleeding GVs and the death risk is relatively higher when recurrent GV hemorrhage occurs so this is worthy of attention.

(1)電解槽。電解槽對(duì)電鎳產(chǎn)品質(zhì)量和生產(chǎn)效益影響巨大，本項(xiàng)目通過借鑒其他鎳項(xiàng)目電解槽防腐方法，對(duì)電解槽結(jié)構(gòu)、防腐材料、防腐方法改進(jìn)后，防腐性能進(jìn)一步提高，在5年多的生產(chǎn)使用過程中未發(fā)現(xiàn)電解槽襯里分層、開裂、滲漏現(xiàn)象。

FlNAL DlAGNOSlS

LSPH and GV hemorrhage.

TREATMENT

The patient requested endoscopic procedures and rejected surgical therapies including splenectomy.EUS-guided selective NBC injections were performed for the treatment and prophylaxis of GV hemorrhage.

A linear Pentax echoendoscope (Hoya Co., Tokyo, Japan) and the color Doppler flow imaging were employed to determine the puncture site. EUS revealed an enlarged portal vein without cavernous transformation (Figure 3A). The confluences of GVs were selected as the injection sites to reduce the injection dose. A 22-gauge needle (Boston Scientific Co., Natick, MA, United States) was used to perform the puncture into the selected GVs (Figure 3B). The “sandwich” method using undiluted NBC(0.5 mL/ampoule; Beijing Compont Medical Devices Co., Beijing, China) and hypertonic glucose was applied (Figure 3C). A total of 2 mL of NBC was injected into three different confluences of GVs.Hyperechoic fillings and decreased blood flow signals were observed after injections (Figure 3D).

OUTCOME AND FOLLOW-UP

The patient fasted for 1 d after the procedure. No complications, including ectopic embolism, fever and post-injection GI bleeding occurred. The patient was followed up regularly after discharge. Three months later, the follow-up gastroscopy revealed no sign of NBC expulsion (Figure 4) and follow-up CTV showed improvements in LSPH (Figure 5). No recurrent GI hemorrhage and other complications were reported during the 3-mo follow-up.

DlSCUSSlON

After admission, gastroscopy confirmed GV hemorrhage (IGV1 by Sarin classification), and no esophageal varices or portal hypertensive gastropathy was found (Figure 1). Abdominal computed tomography venography (CTV) revealed stenosis of the proximal superior mesenteric vein, invisible proximal splenic vein and increased collateral circulations (Figure 2). Neither a portal vein thrombosis nor a splenorenal shunt was detected.

It is well known that splenectomy is the most effective treatment for LSPH. However, transjugular intrahepatic portosystemic shunt, balloon retrograde transvenous obliteration, endoscopic injection sclerotherapy (EIS) and endoscopic NBC injection were reported effective for patients who are not suitable or unwilling to choose surgery[11]. Although endoscopic NBC injection therapy has been proven minimally invasive and effective[12], conventional endoscopic NBC injections may also cause severe complications including renal or pulmonary thromboembolism, fever, severe pain caused by intraperitoneal injection, mucosal necrosis at the injection site and GI bleeding[13]. As reported in recent years, an EUS-guided hemostasis treatment, including injection of NBC or in combination with coils,injection of thrombin or absorbable gelatin sponge, and clip-assisted endoscopic NBC injection,demonstrated promising results in reducing complication risks[14,15].

This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BYNC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is noncommercial. See: https://creativecommons.org/Licenses/by-nc/4.0/

CONCLUSlON

Modified EUS-guided selective NBC injection may represent an effective and economical treatment for GV hemorrhage in patients with LSPH.

FOOTNOTES

Yang J, Zeng Y and Zhang JW designed the research study; Yang J and Zhang JW performed the endoscopic procedures; Yang J and Zeng Y performed the literature search, analyzed the data and wrote the manuscript; All authors have read and approved the final manuscript.

Left-sided portal hypertension (LSPH), also known as sinistral portal hypertension or regional portal hypertension, refers to extrahepatic portal hypertension caused by splenic vein obstruction or stenosis[1-3]. LSPH accounts for about 5% of extrahepatic portal hypertension and is characterized by isolated gastric varices (GVs) and normal liver functions[3]. Pancreatic diseases are the major causes of LSPH.Most patients with LSPH have no obvious clinical symptoms and they are often diagnosed during the endoscopic examination after gastrointestinal (GI) bleeding. Therefore, LSPH should be considered in patients with pancreatic diseases who develop unexplained GI hemorrhage[1,4].

Nine months previously, this patient was admitted to our hospital due to persistent upper abdominal pain. He was diagnosed with severe acute pancreatitis (SAP) and underwent EUS-guided drainage of a pancreatic walled-off necrosis. He also had a 6-year history of hypertension and took enalapril regularly.

The authors declare that they have no conflict of interest.

The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).

多元化是指多元化的培養(yǎng)目標(biāo)、多元化的培養(yǎng)方式、多元化的課程設(shè)置、多元化的就業(yè)方向。第一，應(yīng)培養(yǎng)適應(yīng)社會(huì)發(fā)展需求的多元化創(chuàng)新人才，完善政府相關(guān)的政策保障制度。第二，完善并落實(shí)高校人才培養(yǎng)的目標(biāo)與方案。第三，提升自我，發(fā)揮學(xué)生的主觀能動(dòng)性。第四，加大宣傳科學(xué)幼教理念的力度，營(yíng)造良好的社會(huì)氛圍，齊抓共管才是達(dá)成目標(biāo)的前提。

Modified EUS-guided selective NBC injection was applied for three distinct advantages in this present case. First, a reduced NBC dose may result in a lower occurrence of post-operational GI bleeding and ectopic embolism. EUS can also provide the detection of submucosal GVs, their confluences and real-time effectiveness evaluation for GV obliteration[7]. These advantages make it possible to identify and select confluences of gastric varices which were in the direction of bleeding gastric vessels and used as injection sites to reduce the injection dose. Although EUS-guided coil injection is reported superior to conventional NBC injection in terms of rebleeding after treatment[16], it was believed that a reduced dose of NBC would be injected into GVs in the modified EUS-guided selective NBC injection, which would lead to lower chances of post-injection ulcer and GI hemorrhage.Besides, reduced NBC dose may result in a similar lower occurrence of ectopic embolism in selective NBC injection as in the coils-combined injection method and clip-assisted injection method. Second,there would be no additional risk of radioactive exposure; coils and metal clips were not used in this modified injection procedure, which decreased the cost of endoscopic procedures. Third, selective NBC injection demonstrated a faster and firmer obliteration effect in GV hemorrhage than thrombin and absorbable gelatin sponge injections, making NBC injection more suitable than other procedures for acute GV bleeding. NBC rarely causes vascular necrosis and was reported superior to EIS in the hemostasis rate for GV bleeding[17]. Thus, EUS-guided selective NBC injection was performed for this patient based on the above factors and the result was adequate. Despite all these advantages, the operation time of EUS-guided selective NBC injection seemed a little longer than that of conventional endoscopic NBC injection due to time consumption to confirm confluences of GVs during the EUS procedure. Additional cases are needed to verify our findings and compare the efficacies and complications of different embolization methods guided by EUS. Currently, this described technique is recommended to be used only in hemodynamically stable patients. To the best of our knowledge, this case is the first report choosing confluences of gastric varices as injection sites to reduce the injection dose and postoperative complications in patients with LSPH.

China

Jian Yang 0000-0001-8170-0727; Yan Zeng 0000-0003-4935-1306; Jun-Wen Zhang 0000-0003-2911-598X.

根據(jù)國(guó)家發(fā)改委有關(guān)部門的統(tǒng)一安排，中國(guó)煤炭加工利用協(xié)會(huì)研究提出了我國(guó)“十二五”期間煤炭工業(yè)環(huán)境保護(hù)、資源綜合利用、煤炭洗選、煤矸石低熱值煤發(fā)電、礦井水利用、節(jié)能、循環(huán)經(jīng)濟(jì)規(guī)劃發(fā)展戰(zhàn)略，以引導(dǎo)煤炭企業(yè)按照科學(xué)發(fā)展觀的要求，轉(zhuǎn)變經(jīng)濟(jì)增長(zhǎng)方式，推動(dòng)煤炭工業(yè)又好又快健康發(fā)展。本文摘要介紹我國(guó)“十一五”期間煤炭洗選加工方面取得的重要成績(jī)、存在的主要問題及“十二五”發(fā)展目標(biāo)。

Chinese Society of Gastroenterology.

Analysis on distribution characteristics of secondary geo-hazards before and after Jiuzhaigou

Zhang H

廣東人吃海鮮火鍋，格外講究，火鍋配以魷魚、海螺肉、雞肉、牛肉、墨魚、牛百葉、海參等生料，再加上蔬菜和佐料。吃時(shí)先將各種海鮮依次倒入沒油的清湯里，煮熟后撈到各人碗中，然后再倒入雞肉、牛肉等。吃完肉類，再倒入香菇、青菜等清口，鮮而不膩，味美無(wú)比。

Filipodia CL

Zhang H