Spectroscopic Evidence of Localized Small Polarons in Low-Dimensional Ionic Liquid Lead-Free Hybrid Perovskites

Rational design is an important approach to consider in the development of low-dimensional hybrid organic-inorganic perovskites (HOIPs). In this study, 1-butyl-1-methyl pyrrolidinium (BMP), 1-(3-aminopropyl)imidazole (API), and 1-butyl-3-methyl imidazolium (BMI) serve as prototypical ionic liquid components in bismuth-based HOIPs. Element-sensitive X-ray absorption spectroscopy measurements of BMPBiBr4 and APIBiBr5 reveal distinct resonant excitation profiles across the N K-edges, where contrasting peak shifts are observed. These 1D-HOIPs exhibit a large Stokes shift due to the small polaron contribution, as probed by photoluminescence spectroscopy at room temperature. Interestingly, the incorporation of a small fraction of tin (Sn) into the APIBiBr5 (Sn/Bi mole ratio of 1:3) structure demonstrates a strong spectral weight transfer accompanied by a fast decay lifetime (2.6 ns). These phenomena are the direct result of Sn-substitution in APIBiBr5, decreasing the small polaron effect. By changing the active ionic liquid, the electronic interactions and optical responses can be moderately tuned by alteration of their intermolecular interaction between the semiconducting inorganic layers and organic moieties.

Giant Bladder stone and rectal prolapse complication in pediatric patient: Case report and literature review

INTRODUCTION AND IMPORTANCE

A giant bladder stone (BS) in the urinary tract system with a rectal prolapse complication is a rare urologic problem; it is even rarer in pediatric patients. In the case of bladder stone formation, a variety of steps result in a variety of stone compositions. This study aims to understand the rare disease course of a one-year-old patient with bladder and urethral stones and a rectal prolapse complication.

CASE PRESENTATION

A one-year-old boy presented with an inability to urinate since morning. It was a recurring incident for about a year but never resolved. The patients experienced irregular diarrhea and difficulty eating and drinking. Anal inspection revealed prolapse recti. The laboratory investigation found leukocytosis and anemia with normal blood urea nitrogen and creatinine. Urine tests revealed leukocyturia and hematuria. A plain radiograph of the abdomen showed a round opacity around the pelvic area. Ultrasonography of the abdomen and urinary tract revealed a giant BS and severe bilateral hydronephrosis. Thus, a cystolithotomy procedure was performed, and an additional urethral stone was found. Obtained bladder stones with a size of 30 × 21 × 15mm, with 57 % of uric acid and 33 % of calcium oxalate. A manual reduction of the prolapsed rectum was also performed during surgery. There was no recurrence of the prolapsed rectum after surgery.

CLINICAL DISCUSSION

BS is very rare in the pediatric population. The development of our case's stone composition starts with pure uric acid, which is later enveloped by calcium oxalate due to its lack of acidic atmosphere. Rectal prolapse occurs due to increased abdominal pressure caused by straining during urination.

CONCLUSION

The pathogenesis of BS is multifactorial, with local and systemic factors. Early diagnosis and comprehensive history-taking are essential for BS management decisions. The management of BS depends on its size, composition, and symptoms.

How Effective is Angiotensin II in Decreasing Mortality of Vasodilatory Shock? A Systematic Review

Background

Patients with severe vasodilation accompanied by refractory hypotension despite high doses of vasopressors were associated with a high mortality rate. The Ang-2 for the Treatment of High-Output Shock (ATHOS) 3 trial demonstrated that angiotensin 2 (Ang-2) could effectively increase MAP and blood pressure in vasodilatory shock patients. This systematic review aims to summarize the impact of Ang-2 for the treatment of vasodilatory shock on clinical outcomes, including length of stay, MAP level (before and after), and mortality also Ang-2 dose needed.

Methods

A systematic search in PubMed, Sage, ScienceDirect, Scopus and Gray literature was conducted to obtain studies about the use of Ang-2 in vasodilatory shock patients.

Results

In all of the studies that we obtained, there were different results regarding mortality in patients with vasodilatory shock with Ang-2. Mortality was significantly lower when Ang-2 was administered to patients with elevated renin. The initial dose of Ang-2 can be started at 10-20 ng/kg/min, but there is no agreement on the maximum dose. Ang-2 may be considered a third-line vasopressor if the targeted MAP has not been achieved after administration of norepinephrine >200 ng/kg/min for more than 6 hours. Although not statistically significant, the use of Ang-2 can reduce the length of stay in the ICU and in the hospital when compared to patients without Ang-2 therapy, in addition to reducing the dose of vasopressor.

Conclusion

Overall, the use of Ang-2 has potential to be a regimen for patients with vasodilatory shock. Further study is needed to obtain more data.