Binding of Hydrogen Sulfide by Bismuth Does Not Prevent Dextran Sulfate-Induced Colitis in Rats

Several lines of evidence suggest that ulcerative colitis could be caused by excessive bacterial production of H₂S in the colon. A rodent model of colitis involves the feeding of nonabsorbable, carbohydrate-bound sulfate in the form of dextran sulfate or carrageenan. The observation that metronidazole blocks the development of this colitis suggested that the injurious agent could be a sulfur-containing compound (such as H₂S) that is released during the bacterial metabolism of the nonabsorbed sulfate. We tested this possibility by feeding rats dextran sulfate, with or without bismuth subsalicylate, a compound that avidly binds H₂S. Bismuth subsalicylate reduced the fecal release of H₂S in dextran sulfate-treated rats to values well below that of controls. Nevertheless, all the animals developed colitis. We conclude that excessive H₂S production does not play a role in the dextran sulfate model of colitis.     

Low Temperature Magnetic Transition of BiFeO3 Ceramics Sintered by Electric Field-Assisted Methods: Flash and Spark Plasma Sintering

Low temperature magnetic properties of BiFeO₃ powders sintered by flash and spark plasma sintering were studied. An anomaly observed in the magnetic measurements at 250 K proves the clear existence of a phase transition. This transformation, which becomes less well-defined as the grain sizes are reduced to nanometer scale, was described with regard to a magneto-elastic coupling. Furthermore, the samples exhibited enhanced ferromagnetic properties as compared with those of a pellet prepared by the conventional solid-state technique, with both a higher coercivity field and remnant magnetization, reaching a maximum value of 1.17 kOe and 8.5 10⁻³ emu/g, respectively, for the specimen sintered by flash sintering, which possesses the smallest grains. The specimens also show more significant exchange bias, from 22 to 177 Oe for the specimen prepared by the solid-state method and flash sintering technique, respectively. The observed increase in this parameter is explained in terms of a stronger exchange interaction between ferromagnetic and antiferromagnetic grains in the case of the pellet sintered by flash sintering.     

Effects of bismuth citrate on the viability and function of Leydig cells and testicular macrophages

Bismuth is present in several popular over-the-counter drugs for nausea and diarrhea and is occasionally abused by patients with chronic gastrointestinal disorders. The most common consequence of bismuth overdose is neurological dysfunction. In experimental animals, bismuth overdose results in lowered serum testosterone levels, suggesting that reproductive dysfunction may be an additional component of bismuth toxicity. Although the precise mechanisms responsible for the lowered testosterone levels are unknown, it has been shown that bismuth accumulates within testicular macrophages. This may be important because these cells, which are commonly found in direct contact with Leydig cells, are known to exert paracrine influences on the Leydig cells for local control of testosterone production. However, bismuth may also exert direct effects on Leydig cells because it passes by these cells on its way to the phagocytic macrophages. The purpose of the present studies was to isolate both testicular macrophages and Leydig cells from rat testis and study the direct effects of bismuth on these cells with regard to their viability and function. We found that when Leydig cells were treated for 24 h with bismuth (1-100 microM) no change in viability or secretion of testosterone was observed. However, when testicular macrophages were similarly treated with bismuth a significant effect on viability was observed with as little as 6.25 microM bismuth, with near-complete cell death at 50 microM after 24 h. However, bismuth had no effect on the viability on testicular macrophages at 50 microM up to 8 h, therefore, we studied the secretion of tumor necrosis factor alpha (TNF-alpha) after 4 h of exposure to 50 microM bismuth and found no influence on the production of TNF-alpha. Taken together, it seems likely that bismuth has no direct effects on Leydig cells but, rather, lowers testosterone levels by killing testicular macrophages, thereby interrupting their local paracrine influence on Leydig cells through factors other than TNF-alpha.     

Bismuth Sodium Titanate Based Materials for Piezoelectric Actuators

The ban of lead in many electronic products and the expectation that, sooner or later, this ban will include the currently exempt piezoelectric ceramics based on Lead-Zirconate-Titanate has motivated many research groups to look for lead-free substitutes. After a short overview on different classes of lead-free piezoelectric ceramics with large strain, this review will focus on Bismuth-Sodium-Titanate and its solid solutions. These compounds exhibit extraordinarily high strain, due to a field induced phase transition, which makes them attractive for actuator applications. The structural features of these materials and the origin of the field-induced strain will be revised. Technologies for texturing, which increases the useable strain, will be introduced. Finally, the features that are relevant for the application of these materials in a multilayer design will be summarized.     

两种短程三联方案治疗飞行员幽门螺杆菌阳性消化性溃疡疗效分析

目的研究呋喃唑酮(F)或甲硝唑(M)联用阿莫西林(A)及枸橼酸铋钾(C)1周疗法治疗飞行员幽门螺杆菌(Hp)阳性消化性溃疡的疗效。方法60例飞行员经胃镜证实惠有直径≥3mm的活动期消化性溃疡．随机分为治疗组和对照组，每组各30例。治疗组(CAF)给予呋喃唑酮0．1g，3／日；联用枸橼酸铋钾0．22g，2／日；阿莫西林1g，3／日。对照组(MAF)给予甲硝唑0．4g，3／日，联用枸橼酸铋钾0．22g，2／日；阿莫西林1g，3／日。疗程均为7日。结果溃疡愈合率，HP根除率治疗组分别为93％、93％，而对照组分别为76％、70%，两组比较差异有显著性。治疗1日、3日、7日缓解腹痛显效率治疗组分别为63％、90%、97％，对照组分别为53％、69％、76%，两组比较差异有显著性。两组均无严重不良反应，患者依从性较好。结论CAF疗法较MAF疗法疗效好，不良反应少，依从性好。是更理想的消化性溃疡治疗方案。     

铋剂四联10天疗法联合酪酸梭菌、聚普瑞锌治疗幽门螺杆菌感染的疗效分析

目的 评价铋剂四联10 d疗法联合酪酸梭菌、聚普瑞锌治疗幽门螺杆菌（Hp）感染的疗效及安全性。方法 选取2018年7月—2021年6月于湘雅常德医院就诊使用铋剂四联10 d疗法联合酪酸梭菌、聚普瑞锌治疗Hp感染的209例患者作为研究对象。患者采用艾司奥美拉唑镁肠溶片（20 mg）+阿莫西林胶囊（1 g）+克拉霉素（0.5 mg）+胶体酒石酸铋胶囊（220 mg）均2次/d,酪酸梭菌活菌片（350 mg）3次/d,疗程10 d。后续追加艾司奥美拉唑肠溶片（20 mg,1次/d）+酪酸梭菌活菌片（350 mg,3次/d）+聚普瑞锌颗粒（75 mg,2次/d）,疗程14 d。结果 符合方案集分析（PP）和意向性分析（ITT）的Hp根除成功率分别为97.4%（189/194）和90.4%（189/209）,9例（4.4%）患者在治疗期间出现不良反应,但程度均较轻微,可自行缓解。结论 铋剂四联10 d疗法联合酪酸梭菌、聚普瑞锌作为Hp感染的治疗方案,根除率高,安全可行,在缩短抗生素疗程的同时不仅增加患者的依从性,也减少细菌产生耐药性。     

复方儿茶胶囊治疗消化性溃疡疗效观察

目的观察复方儿茶胶囊对消化性溃疡的近期和远期疗效。方法经胃镜确诊的消化性溃疡261例,随机分为西米替丁组87例(西米替丁0.2g,每天3次口服,睡前加服0.4g),丽珠得乐组87例(丽珠得乐110mg,每天4次口服),复方儿茶胶囊组87例(复方儿茶胶囊0.515g,每天3次口服)。治疗前、治疗8周后及1年后距幽门5cm以内取胃组织,用快速尿素酶法测定幽门螺杆菌(HP)。结果西米替丁组、丽珠得乐组、复方儿茶胶囊组总有效率分别为86.2％,88.5％．97.7％,复方儿茶胶囊组与前两组相比P＜0.05。溃疡愈合率分别为70.1％．75.9％,90.8％．复方儿茶胶囊组与前两组相比P＜0.05。HP根除率分别为1.9％,57.4％,76.8％,复方儿茶胶囊组与丽珠得乐组相比P＜0.05,与西米替丁组相比P＜0.01。结论复方儿茶胶囊组溃疡近期疗效及HP根除率均高于西米替丁组和丽珠得乐组,复发率均低于西米替丁组和丽珠得乐组。     

Two-Step Synthesis of Bismuth-Based Hybrid Halide Perovskite Thin-Films

Lead halide perovskites have been revolutionary in the last decade in many optoelectronic sectors. Their bismuth-based counterparts have been considered a good alternative thanks to their composition of earth-abundant elements, good chemical stability, and low toxicity. Moreover, their electronic structure is in a quasi-zero-dimensional (0D) configuration, and they have recently been explored for use beyond optoelectronics. A significant limitation in applying thin-film technology is represented by the difficulty of synthesizing compact layers with easily scalable methods. Here, the engineering of a two-step synthesis in an air of methylammonium bismuth iodide compact thin films is reported. The critical steps of the process have been highlighted so that the procedure can be adapted to different substrates and application areas.     

Does bismuth subgallate have haemostatic effects in tonsillectomy?

Previous studies have shown that bismuth subgallate added to gauze swabs in tonsillectomy reduces the time to achieve haemostasis and probably reduces the risk of postoperative haemorrhage. All these studies have used bismuth subgallate in combination with adrenaline. In this randomised clinical study we investigated the effect of bismuth subgallate alone. A total of 204 patients were randomised into two groups. One hundred and six patients had swabs with bismuth subgallate. In the control group (n = 98), plain swabs were used. Operating time, time to achieve haemostasis, peroperative blood loss, and incidence of postoperative haemorrhages were recorded. There were no significant differences between the two groups. We conclude that the evidence for using bismuth subgallate as a haemostatic agent in tonsillectomy is weak. The effect observed in previous studies can probably be ascribed to the effect of adrenaline.