Safety and efficacy of modified endoscopic ultrasound-guided selective N-butyl-2-cyanoacrylate injections for gastric variceal hemorrhage in left-sided portal hypertension

BACKGROUND Gastric variceal hemorrhage is one of the primary manifestations of left-sided portal hypertension(LSPH).The hemorrhage is fatal and requires safe and effective interventions.AIM To evaluate the clinical safety and efficacy of modified endoscopic ultrasound(EUS)-guided selective N-butyl-2-cyanoacrylate(NBC)injections for gastric variceal hemorrhage in LSPH.METHODS A retrospective observational study of patients with LSPH-induced gastric variceal hemorrhage was conducted.Preoperative EUS evaluations were performed.Enrolled patients were divided into modified and conventional groups according to the NBC injection technique.The final selection of NBC injection technique depended on the patients’preferences and clinical status.The technical and clinical success rates,operation time,NBC doses,perioperative complications,postoperative hospital stay,and recurrent bleeding rates were analyzed,respectively.RESULTS A total of 27 patients were enrolled.No statistically significant differences were observed between the two groups regarding baseline characteristics.In comparison to patients in the conventional group,patients in the modified group demonstrated significantly reduced NBC doses(2.0±0.6 mL vs 3.1±1.0 mL;P=0.004)and increased endoscopic operation time(71.9±11.9 min vs 22.5±6.7 min;P<0.001).Meanwhile,the two groups had no significant difference in the technical and clinical success rates,perioperative complications,postoperative hospital stay,and recurrent bleeding rates.CONCLUSION Modified EUS-guided selective NBC injections demonstrated safety and efficacy for LSPH-induced gastric variceal hemorrhage,with advantages of reduced injection dose and no radiation risk.Drawbacks were time consumption and technical challenge.

Production of linear alkylbenzene over Ce containing Beta zeolites

Ce-encapsulated Beta zeolite was synthesized by a one-pot hydrothermal method with citric acid complexing Ce in the absence of Na species.Additional citric acid can effectively prevent the deposition of Ce species during the hydrothermal synthesis of zeolites,leading to uniform distribution of Ce cluster in the framework of Beta zeolites.Moreover,the sodium-free synthesis system resulted that the Brønsted acid sites were mainly located on the straight channels and external surface of Beta zeolites,improving the utilization of Brønsted acid sites.In addition,Ce encapsulated Beta zeolites showed enhanced activity and robust stability in the alkylation of benzene with 1-dodecene based on the synergistic effect between Ce species and Brønsted acid sites,which pave the way for its practical application in the production of alkylbenzene.

Synthesis of spherical nano-ZSM-5 zeolite with intergranular mesoporous for alkylation of ethylbenzene with ethanol to produce m-diethylbenzene

Catalytic synthesis of m-diethylbenzene(m-DEB)through alkylation of ethylbenzene(EB)may be a promising alternative route in comparison with traditional rectification of mixed DEB,for which the top priority is to develop efficient and stable heterogeneous catalysts.Here,the spherical nano-ZSM-5 zeolite with abundant intergranular mesoporous is synthesized by the seed-mediated growth method for alkylation of EB with ethanol to produce m-DEB.The results show that the spherical nano-ZSM-5 zeolite exhibits better stability and higher alkylation activity at a lower temperature than those of commercial micropore ZSM-5.And then,the spherical nano-ZSM-5 is further modified by La_(2)O_(3) through acid treatment followed by immersion method.The acid treatment causes nano-ZSM-5 to exhibit the increased pore size but decreased the acid sites,and subsequent La_(2)O_(3) loading reintroduces the weak acid sites.As a result,the HNO_(3)-La_(2)O_(3)-modified catalyst exhibits a slight increase in EB conversion and DEB yield in comparison with unmodified one,and meanwhile,it still maintains high m-DEB selectivity.The catalyst after acid treatment achieves higher catalytic stability besides maintaining the high alkylation activity of EB with ethanol.The present study on the spherical nano-HZSM-5 zeolite and its modification catalyst with excellent alkylation ability provides new insights into the production of mDEB.

Tandem hydroalkylation and deoxygenation of lignin-derived phenolics to synthesize high-density fuels

Lignin is the most abundant naturally phenolic biomass,and the synthesis of high-performance renewable fuel from lignin has attracted significant attention.We propose the efficient synthesis of high-density fuels using simulated lignin cracked oil in tandem with hydroalkylation and deoxygenation reactions.First,we investigated the reaction pathway for the hydroalkylation of phenol,which competes with the hydrodeoxygenation form cyclohexane.And then,we investigated the effects of metal catalyst types,the loading amount of metallic,acid dosage,and reactant ratio on the reaction results.The phenol hydroalkylation and hydrodeoxygenation were balanced when 180℃ and 5 MPa H_(2)with the alkanes yield of 95%.By extending the substrate to other lignin-derived phenolics and simulated lignin cracked oil,we obtained the polycyclic alkane fuel with high density of 0.918 g·ml^(-1)and calorific value of41.2 MJ·L^(-1).Besides,the fuel has good low-temperature properties(viscosity of 9.3 mm^(2)·s^(-1)at 20℃ and freezing point below-55℃),which is expected to be used as jet fuel.This work provides a promising way for the easy and green production of high-density fuel directly from real lignin oil.

Alkylene-functionality in bridged and fused nitrogen-rich poly-cyclic energetic materials:Synthesis,structural diversity and energetic properties

From the standpoint of chemical structures,the organic backbones of energetic materials can be classified into aromatic rings,nonaromatic rings,and open chains.Although the category of aromatic energetic compounds exhibits several advantages in the regulation of energetic properties,the nonaromatic heterocycles,assembling nitramino explosophores with simple alkyl bridges,still have prevailed in benchmark materials.The methylene bridge plays a pivotal role in the constructions of the classic nonaromatic heterocycle-based energetic compounds,e.g.,hexahydro-1,3,5-trinitro-1,3,5-triazine(RDX)and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine(HMX),whereas ethylene bridge is the core moiety of state-of-the-art explosive 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(CL-20).In this context,it is of great interest to employ simple and practical bridges to assemble aromatic and nonaromatic nitrogen-rich heterocycles,thereby expanding the structural diversity of energetic materials,e.g.,bridged and fused nitrogen-rich poly-heterocycles.Furthermore,alkyl-bridged poly-heterocycles highlight the potential for the open chain type of energetic materials.In this review,the development of alkyl bridges in linking nitrogen-rich heterocycles is presented,and the perspective of the newly constructed energetic backbones is summarized for the future design of advanced energetic materials.

Pilot Test of Preparing 2-Alkylanthraquinone Using Alkylation-Oxidation Technology

To expedite the development of industrial technology for producing 2-alkylanthraquinone,a novel pilot test of alkylation-oxidation technology was conducted.The process mainly included anthracene alkylation,separation of anthracene and 2-alkylanthracene,oxidation of 2-alkylanthracene,and product purification.Optimal alkylation conditions yielded a 91.1%conversion of anthracene and a 71.73%selectivity for 2-alkylanthracene.To address the separation problem of anthracene and 2-alkylanthracene,solvent-assisted distillation technology was developed,resulting in a 98.9%purity of 2-alkylanthracene and a 91.82%separation yield.When the molar ratio of H2O_(2) to 2-alkylanthracene was 7:1,a 98.96%conversion of 2-alkylanthracene and a 99.94%selectivity for 2-alkylanthraquinone were achieved.A novel composition of 2-alkylanthraquinone,including 2-tert-butylanthraquinone,2-tert-amylanthraquinone,and 2-hexylanthraquinone,was developed.This composition could be effectively separated and purified through a combination of crystallization and washing processes.The elemental composition of the product met the existing standards,and its hydrogenation performance closely matched that of commercially available 2-tert-amylanthraquinone products.

Regulating^(*)COOH intermediate via amino alkylation engineering for exceptionally effective photocatalytic CO_(2) reduction

Photocatalytic reduction of CO_(2) into fuel represents a promising approach for achieving carbon neutrality,while realizing high selectivity in this process is challenging due to uncontrollable reaction intermediate and retarded desorption of target products.Engineering the interface microenvironment of catalysts has been proposed as a strategy to exert a significant influence on reaction outcomes,yet it remains a significant challenge.In this study,amino alkylation was successfully integrated into the melem unit of polymeric carbon nitrides(PCN),which could efficiently drive the photocatalytic CO_(2) reduction.Experimental characterization and theoretical calculations revealed that the introduction of amino alkylation lowers the energy barrier for CO_(2) reduction into^(*)COOH intermediate,transforming the adsorption of^(*)COOH intermediate from the endothermic to an exothermic process.Notably,the as-prepared materials demonstrated outstanding performance in photocatalytic CO_(2) reduction,yielding CO_(2)at a rate of 152.8μmol h^(-1) with a high selectivity of 95.4%and a quantum efficiency of 6.6%.

N-butyl-2-cyanoacrylate, iso-amyl-2-cyanoacrylate and hypertonic glucose with 72% chromated glycerin in gastric varices

AIM: To compare n-butyl-2-cyanoacrylate, iso-amyl-2-cyanoacrylate and a mixture of 72% chromated glycerin with hypertonic glucose solution in management of gastric varices. METHODS: Ninety patients with gastric varices presented to Endoscopy Unit of Ain Shams University Hospital were included. They were randomly allocated into three groups; each group included 30 patients treated with intravariceal sclerosant injections in biweekly sessions till complete obturation of gastric varices; Group I(n-butyl-2-cyanoacrylate; Histoacryl), Group II(iso-amyl-2-cyanoacrylate; Amcrylate) and Group III(mixture of 72% chromated glycerin; Scleremo with glucose solution 25%). All the procedures were performed electively without active bleeding. Recruited patients were followed up for 3 mo. RESULTS: 26% of Scleremo group had bleeding during puncture vs 3.3% in each of the other two groups with significant difference,(P < 0.05). None of Scleremo group had needle obstruction vs 13.3% in each of the other two groups with no significant difference,(P > 0.05). Rebleeding occurred in 13.3% of Histoacryl and Amcrylate groups vs 0% in Scleremo group with no significant difference. The in hospital mortality was 6.6% in both Histoacryl and Amcrylate groups, while it was 0% in Scleremo group with no significant difference. In the first and second sessions, the amount of Scleremo needed for obturation was significantly high, while the amount of Histoacryl was significantly low. Scleremo was the less costly of the two treatments. CONCLUSION: All used sclerosant substances showed efficacy and success in management of gastric varices with no significant differences except in total amount, cost and bleeding during puncture.

Cerebral and splenic infarctions after injection of N-butyl-2-cyanoacrylate in esophageal variceal bleeding

Variceal bleeding is the most serious complication of portal hypertension,and it accounts for approximately one fifth to one third of all deaths in liver cirrhosis patients.Currently,endoscopic treatment remains the predominant method for the prevention and treatment of variceal bleeding.Endoscopic treatments include band ligation and injection sclerotherapy.Injection sclerotherapy with N-butyl-2-cyanoacrylate has been successfully used to treat variceal bleeding.Although injection sclerotherapy with N-butyl-2-cyanoacrylate provides effective treatment for variceal bleeding,injection of N-butyl-2-cyanoacrylate is associated with a variety of complications,including systemic embolization.Herein,we report a case of cerebral and splenic infarctions after the injection of N-butyl-2-cyanoacrylate to treat esophageal variceal bleeding.

Endoscopic management of Dieulafoy's lesion using Isoamyl-2-cyanoacrylate

Dieulafoy's lesion (DL) is a rare but important cause of obscure gastrointestinal bleeding that may be over-looked during diagnostic endoscopy. Mortality rates are similar to those of other causes for gastrointestinal bleeding. Diagnosis by upper endoscopy is the modal-ity of choice during acute bleeding. In the absence of active bleeding, the lesion resembles a raised nipple or visible vessel. There are no guidelines regarding effective selective therapy for DL, when diagnosed, en-doscopist experience is the major determinant of the treatment strategy. Following our strategy, an expert endoscopist with a skilled assistant should have a high rate of successful DL diagnosis when an obscured gas-trointestinal lesion is suspected. Cyanoacryltes com-pounds have been used successfully in management of Gastric varices and DLs. To our knowledge, there have been no previous reports regarding use of isoamyl-2-cyanoacrylate (AMCRYLATE ; Concord Drugs Ltd.,Hyderabad, India) as an effective therapy for gastric DL without serious complications. In our case study, Isoamyl-2-cyanoacrylate (AMCRYLATE) was effective and safe for treating DL. Surgical wedge resection of the lesion should be considered as a therapeutic option if endoscopic therapy fails.

Modified endoscopic ultrasound-guided selective N-butyl-2-cyanoacrylate injections for gastric variceal hemorrhage in left-sided portal hypertension:A case report

BACKGROUND 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.N-butyl-2-cyanoacrylate(NBC)has been widely used in the endoscopic hemostasis of portal hypertension,but adverse events including renal or pulmonary thromboembolism,mucosal necrosis and gastrointestinal(GI)bleeding may occur after treatment.Herein,we report successfully managing gastric variceal(GV)hemorrhage secondary to LSPH using modified endoscopic ultrasound(EUS)-guided selective NBC injections.CASE SUMMARY A 35-year-old man was referred to our hospital due to an upper GI hemorrhage.Gastroscopy revealed GV hemorrhage and computed tomography venography(CTV)confirmed LSPH.The patient requested endoscopic procedures and rejected surgical therapies including splenectomy.EUS-guided selective NBC injections were performed and confluences of gastric varices were selected as the injection sites to reduce the injection dose.The“sandwich”method using undiluted NBC and hypertonic glucose was applied.No complications occurred.The patient was followed up regularly after discharge.Three months later,the follow-up gastroscopy revealed firm gastric submucosa with no sign of NBC expulsion and the follow-up CTV showed improvements in LSPH.No recurrent GI hemorrhage was reported during this follow-up period.CONCLUSION EUS-guided selective NBC injection may represent an effective and economical treatment for GV hemorrhage in patients with LSPH.

Elucidating the effect of oxides on the zeolite catalyzed alkylation of benzene with 1-dodecene

In the present work, the effect of oxides on the alkylation of benzene with 1-dodecene was comprehensively investigated over MCM-49 n-heptanol, n-heptaldehyde and n-heptanoic acid were selected as the model oxides herein, and obvious decrease of lifetime could be caused by only trace amount of oxides added in the feedstocks. However, the deactivated catalysts were difficult to be regenerated by extraction with hot benzene. Additionally, coke-burning was also proved to be incapable to regenerate the deactivated catalysts mainly for the dealumination during calcination. Further characterizations complementary with DFT calculations were conducted to demonstrate that the deactivation was mainly due to the firm adsorption of oxides on the acid sites.

Synthesis of Fluorene Derivatives Via TfOH-catalyzed Intramolecular Friedel-Crafts Alkylation Reactions

We devoloped an efficient and simple method to synthesize fluorene derivatives via intramolecular Friedel-Crafts alkylation of chalcones.The transform is catalyzed by TfOH in CH_(3)NO_(2)at 80℃and the yield is up to 99%.

Understanding the interfacial behaviors of benzene alkylation with butene using chloroaluminate ionic liquid catalyst: A molecular dynamics simulation

To better understand the benzene alkylation with chloroaluminate ionic liquids(ILs) as catalyst, the interfacial properties between the benzene/butene binary reactants and chloroaluminate ILs with varying cation alkyl chain length and different anions were investigated using molecular dynamics(MD) simulations. The results indicate that ILs can obviously improve the interfacial width, solubility and diffusion of reactants compared to H_(2)SO_(4). The longer alkyl chains of cations present a density enrichment at the interface and protrude into the binary reactants phase. Furthermore, the ILs consisting of 1-octyl-3-methylimidazolium cations([Omim]^(+)) and the stronger acidity heptachlorodialuminate anions([Al_(2)Cl_(7)]^(-)) are more beneficial to promote the interfacial width and facilitate the dissolution and diffusion of benzene in both the IL bulk and the interfacial region in comparison to the ones with shorter alkyl chains cations and weaker acidity anions. The information gives us a better guideline for the design of ILs for benzene alkylation.

Low-temperature photothermal-induced alkyl radical release facilitates dihydroartemisinin-triggered“valve-off”starvation therapy

The high nutrient and energy demand of tumor cells compared to normal cells to sustain rapid proliferation offer a potentially auspicious avenue for implementing starvation therapy.However,conventional starvation therapy,such as glucose exhaustion and vascular thrombosis,can lead to systemic toxicity and exacerbate tumor hypoxia.Herein,we developed a new“valve-off”starvation tactic,which was accomplished by closing the valve of glucose transporter protein 1(GLUT1).Specifically,dihydroartemisinin(DHA),2,20-azobis[2-(2-imidazolin-2-yl)propane]dihydrochloride(AI),and Ink were co-encapsulated in a sodium alginate(ALG)hydrogel.Upon irradiation with the 1064 nm laser,AI rapidly disintegrated into alkyl radicals(R·),which exacerbated the DHA-induced mitochondrial damage through the generation of reactive oxygen species and further reduced the synthesis of adenosine triphosphate(ATP).Simultaneously,the production of R·facilitated DHA-induced starvation therapy by suppressing GLUT1,which in turn reduced glucose uptake.Systematic in vivo and in vitro results suggested that this radical-enhanced“valveoff”strategy for inducing tumor cell starvation was effective in reducing glucose uptake and ATP levels.This integrated strategy induces tumor starvation with efficient tumor suppression,creating a new avenue for controlled,precise,and concerted tumor therapy.

Alkyl-tetralin base oils synthesized from coal-based chemicals and evaluation of their lubricating properties

Naphthenic base oil is an important lubricating base oil and very scarce in the global petroleum resources.Herein,a series of alkylated tetralin fluids similar to naphthenic base oils were produced by the alkylation of tetralin and a-olefins(n-hexene,n-octene,n-decene)with ionic liquid Et_3NHCl/AlCl_(3)as the catalyst,where the applied raw materials are totally derived from the coal chemical industry.The product composition could be controlled by adjusting the feeding ratio of tetralin and olefin.The synthetic fluids were evaluated as lubricating base oils to reveal the structure-property correlations.Their principal physicochemical and tribological properties depend on the chain-length of a-olefins and the number of alkyl groups onto the aromatic rings.Bis-(octyl-or decyl-)alkyl tetralin exhibited good properties in terms of viscosity,thermo-oxidation stability and pour point,as well as friction-reducing and anti-wear performance,showing great potential for producing naphthenic base synthetic oils from coal-based chemicals.

Endovascular treatment of traumatic direct carotid cavernous fistulas with n-Butyl-2-Cyanoacrylate

Objective To explore the method and safety of endovascular treatment of traumatic direct carotid cavernous fistulas with n-Butyl-2-Cyanoacrylate. Method A total of 11 patients with traumatic direct carotid cavernous fistulas treated by endovascular embolization with n-Butyl-2-Cyanoacrylate. (n-BCA) were retrospectively analyzed,including the

环状ZSM-5分子筛在苯和乙醇烷基化反应中的应用

低温下采用水热晶化法合成了环状中空ZSM-5分子筛,并以磷酸二氢铵为前体,制备了不同磷负载量的环状中空ZSM-5催化剂,采用XRD,SEM,NH_(3)-TPD,Py-FTIR等方法对催化剂进行表征,并在气相连续流动固定床反应器上对苯和乙醇烷基化制乙苯进行性能评价和稳定性考察。实验结果表明,环状中空ZSM-5催化剂进行磷改性后,催化剂的酸强度降低,随着磷负载量的增加,乙苯选择性逐渐增加,甲苯和丙苯选择性逐渐降低;当磷负载量达到3%(w)后,催化剂外表面强酸位基本消失,此时乙苯选择性最高;在n(苯)∶n(乙醇)=8∶1、340℃、1.0 MPa、WHSV=1 h^(-1)条件下,对该催化剂进行了寿命考察,在300 h反应过程中,乙醇转化率超过99.9%,苯的转化率维持在11%左右,乙基苯的选择性最高达到98.4%,二甲苯相对含量最低达到0.11%。

伊立替康药物中间体7-乙基喜树碱合成的课程思政设计

抗癌药物伊立替康中间体7-乙基喜树碱的合成是杂环芳烃的烷基化反应。本案例通过将实验过程与药物合成和“健康中国”相关联,对实验进行了创新性的思政融入设计。师生全员在案例的导入、研讨、实施、反思与考核的全过程进行全方位的课程思政教育,解决了实验课只注重实验内容而忽略思政教育的问题,实现了“三全育人”。在此过程中不仅激发了学生的学习兴趣,有效地进行了科学思维和创新思维的训练,培养了学生的探索精神和创新意识,而且强化了学生提高原子利用率的绿色化学意识、环保意识和可持续发展意识,提升了学生为健康中国贡献力量的责任感和使命感,坚定了学生运用所学专业知识服务国家的决心和信心。

烷基水杨酸盐清净剂合成工艺研究进展

近年来,随着节约能源和保护环境的要求逐渐提高,发动机设计日益向小型化,大功率和高速度方向发展,因此对内燃机油的高温清净性能提出了越来越苛刻的要求,低硫低磷及低灰分型内燃机油将是未来发展的方向。烷基水杨酸盐具有优异的清净作用及酸中和性能,且具备一定的抗氧化和抗腐蚀能力,是内燃机油的主要添加剂之一,可满足内燃机油低硫低磷及低灰分的要求。对烷基水杨酸盐的传统及改进的合成工艺进行了综述。传统合成工艺严重制约了烷基水杨酸盐的应用和发展,探索新的合成工艺是烷基水杨酸盐发展的主要方向。