Direct infrared observation of hydrogen chloride anions in solid argon.

To facilitate direct spectroscopic observation of hydrogen chloride anions (HCl-), electron bombardment of CH3Cl diluted in excess Ar during matrix deposition was used to generate this anion. Subsequent characterization were performed by IR spectroscopy and quantum chemical calculations. Moreover the band intensity of HCl- decays slowly when the matrix sample is maintained in the dark for a prolonged time. High-level ab inito calculation suggested that HCl- is only weakly bound. Atom-in-molecule charge analysis indicated that both atoms of HCl- are negatively charged and the Cl atom is hypervalent.

Photochemistry and infrared spectrum of single-bridged diborane(5) anion isolated in solid argon.

Three-center two-electron bonds are important for understanding electron-deficient molecules. To examine such a molecule, we produced a diborane(5) anion with a single-bridged structure upon electron bombardment during matrix deposition of Ar containing a small proportion of diborane(6). The diborane(5) anion was destroyed upon photolysis at 180, 220, 385, and 450 nm, but not at 532 nm. Moreover, the possible formation of neutral diborane(5) was observed upon photolysis at 385 and 450 nm, whereas neutral diborane(3) was observed upon photolysis at 180 and 220 nm. The observed line wavenumbers, relative intensities, and isotopic ratios of the diborane(5) anion agreed satisfactorily with those predicted by density functional theory calculations at the B3LYP/aug-cc-pVTZ level of theory. Thus, this method produced the boron hydride anion of interest with few other fragments, which enabled us to clearly identify the IR spectrum of the diborane(5) anion.

Factors influencing the application of transrectal natural orifice specimen extraction performed laparoscopically for colorectal cancer: A retrospective study.

BACKGROUND: A few factors influence the feasibility of transrectal natural orifice specimen extraction (NOSE) surgery for colorectal cancers. However, little is known about the underlying factors of NOSE surgery. METHODS: Consecutive patients with rectal and sigmoid colon cancers treated laparoscopically between January 2014 and April 2017 were enrolled in this study. The transrectal NOSE performed laparoscopically was the first choice of all patients. When NOSE failed, the specimen was removed through a midline abdominal wall incision. Univariate and multivariate logistic regression analyses were performed to identify challenging factors influencing the intraoperative specimen extraction. RESULTS: Overall, 412 consecutive patients were included. NOSE performed laparoscopically was successful in 278 patients (75.5%) and unsuccessful in 90 patients (24.5%). The multivariate analyses indicated that body mass index (BMI; odds ratio [OR] = 3.510, 95% confidence interval [CI]: 1.333-9.243, p = 0.011), mesenteric thickness (OR = 1.069, 95% CI: 1.032-1.107, p < 0.001), maximum tumor diameter (OR = 2.827, 95% CI: 1.094-7.302, p = 0.032), and tumor T stage (OR = 2.831, 95% CI: 1.258-6.369, p = 0.012) were the factors influencing the feasibility of NOSE surgery. CONCLUSION: A successful transrectal NOSE surgery was associated with a lower BMI, thinner mesentery, lesser tumor diameter, and earlier tumor T stage.

Case Report: Anesthetic Management and Electrical Cardiometry as Intensive Hemodynamic Monitoring During Cheiloplasty in an Infant With Enzyme-Replaced Pompe Disease and Preserved Preoperative Cardiac Function.

Introduction: Pompe disease is caused by deficiency of the lysosomal enzyme acid α-glucosidase, which results in cardiac and muscular complications that can jeopardize perioperative outcomes. We report a 4-month-old infant with Pompe disease receiving cheiloplasty under general anesthesia with the aid of peripheral nerve blocks and intensive hemodynamic monitoring. Case Description: This case report describes a 4-month-old full-term Taiwanese female infant who presented with left unilateral cleft lip and palate in the prenatal examination. She was diagnosed with infantile-onset Pompe disease after acidic α-glucosidase (GAA) gene sequencing. She also received enzyme replacement therapy (ERT) 15 days after birth and regular ERT every other week. Cheiloplasty was performed under general anesthesia uneventfully, and peripheral nerve blocks were adopted for analgesia. Intensive hemodynamic monitoring using electrical cardiometry technology (ICON®) and pulse contour analysis (FloTrac system) were applied during the operation. No adverse effects were observed, and the wound healed well. Therefore, the patient was discharged 4 days after surgery. Conclusion: With the availability of ERT, severe organ dysfunction in infantile-onset Pompe disease patients is no longer common. However, moderate cardiac depression can still occur while increasing inspiratory pressure and deepening the anesthesia level despite a normal preoperative echocardiogram report. Therefore, careful, gradual titration is desirable. Furthermore, electrical cardiometry can detect hemodynamic changes more instantaneously and reliably than pulse contour analysis. In addition, we suggest taking advantage of the peripheral nerve block as a part of balanced anesthesia to alleviate the cardiac suppression caused by general anesthesia.

Identification of a Simplest Hypervalent Hydrogen Fluoride Anion in Solid Argon.

Hypervalent molecules are one of the exceptions to the octet rule. Bonding in most hypervalent molecules is well rationalized by the Rundle-Pimentel model (three-center four-electron bond), and high ionic bonding between the ligands and the central atom is essential for stabilizing hypervalent molecules. Here, we produced one of the simplest hypervalent anions, HF-, which is known to deviate from the Rundle-Pimentel model, and identified its ro-vibrational features. High-level ab inito calculations reveal that its bond dissociation energy is comparable to that of dihalides, as supported by secondary photolysis experiments with irradiation at various wavelengths. The charge distribution analysis suggested that the F atom of HF- is negative and hypervalent and the bonding is more covalent than ionic.