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The ion–molecule reaction is one of the most important pathways for the formation of new interstellar chemical species. Herein, infrared spectra of cationic binary clusters of acrylonitrile (AN) with methanethiol (CH3SH) and dimethyl sulfide (CH3SCH3) are measured and compared to those previous studies of AN and methanol (CH3OH) or dimethyl ether (CH3OCH3). The results suggest that the ion–molecular reactions of AN with CH3SH and CH3SCH3 only yield products with S...HN H-bonded or S∴N hemibond structures, rather than the cyclic products as observed in AN-CH3OH and AN-CH3OCH3 studied previously. The Michael addition-cyclization reaction between acrylonitrile and sulfur-containing molecules does not occur due to the weaker acidity of CH bonds in sulfur-containing molecules, which results from their weaker hyperconjugation effect compared to oxygen-containing molecules. The reduced propensity for the proton transfer from the CH bonds hinders the formation of the Michael addition-cyclization product that follows. [ABSTRACT FROM AUTHOR]

The structure of the host lattice has a substantial influence on the optical properties of lanthanide-doped luminescent materials. Hexagonal-phase (β-phase) NaREF4 (RE = rare earth) is the most commonly used crystal structure for lanthanide-doped upconversion nanoparticles (UCNPs) owing to its high upconversion (UC) efficiency. In this work, we report, for the first time, that more efficient cooperative sensitization upconversion (CSU) can be achieved in cubic-phase (α-phase) NaREF4 UCNPs instead of their β-phase counterparts. With the passivation of an inert shell, the UC emission intensity of α-NaYbF4:Tb40%@CaF2 is 10.5 times higher than that of β-NaYbF4:Tb40%@NaYF4. We propose that the high-symmetry crystal structure of the α phase facilitates the formations of [Yb–Yb] dimers and [Yb–Yb–Tb] clusters, which are particularly beneficial for CSU. Moreover, we prove that such Tb3+-based UCNPs are almost impervious to water quenching because of the large energy gap (∼15,000 cm−1) that existed in Tb3+ between its lowest emit-ting level (5D4) and next low-lying level (7F0). Finally, their potential application for single-nanoparticle imaging has also been demonstrated. As expected, the α-core-shell UCNPs measured at the single-nanoparticle level are estimated to be 9-fold brighter than their β-core-shell counterparts. Importantly, the α-NaYbF4:Tb40%@CaF2 UCNPs offer exciting opportunities for realizing single-nanoparticle imaging at ultralow irradiance (30 W/cm2).

Objective To explore the influencing factors of serum procalcitonin (PCT) levels in patients with sepsis. Methods Medical records of 526 adult sepsis patients (280 males and 246 females) admitted in the geriatrics, emergency department and ICU of our hospital from January 2014 to December 2019, aged 18 to 91 (53 ±19) years old, were cdlected including clinical relevant data before treatment (within 24 h after admission) for analysis. According to different PCT levels, they were divided into: PCT normal group (n=153, < 0.5 ng/mL) and PCT elevated group (n=373, ≥0.5 ng/mL), and logistic regression was used to analyze the influencing factors of PCT level. In combination with the underlying diseases of these patients, one-way analysis of variance, performed was to observe the differences in PCT levels in different combined underlying disease groups. Results The results of multivariate regression analysis showed that patients with sepsis were associated with underlying diseases (OR=1.670, P=0.033), white blood cell count (WBC) was abnormal (OR=1.826, P=0.006), and respiratory rate was increased (OR=2.149, P=0.002), decreased albumin (OR=2.197, P=0.000), increased C-reactive protein (CRP) (OR=2.365, P=0.003), septic shock (OR=10.748, P=0.005) and other factors may be risk factors for elevated PCT levels; one-way analysis of variance showed that PCT levels in the mixed disease group were higher than those in the hypertension, coronary heart disease, diabetes and urinary calculi group (P < 0.05), and the PCT in the diabetes group was higher than the hypertension and coronary heart disease groups (P < 0.05), PCT in the urinary calculi group was higher than that in the hypertension and coronary heart disease groups (P < 0.05). Conclusion Comorbidities, low albumin, and septic shock may be the risk factors for elevated serum PCT levels in patients with sepsis. The types and number of comorbidities will also affect the elevated levels of serum PCT.

Backgrounds: Previous studies have suggested that cerebral dural sinus stenosis could be a possible underlying cause of idiopathic intracranial hypertension (IIH). Venous sinus stenting (VSS) has emerged as a potential alternative for treating IIH related to dural sinus stenosis. However, most of the documented studies have been conducted in Western countries. In this study, we present the results of 16 Chinese IIH patients who underwent VSS treatment in our single center. Methods: We prospectively collected angiographic and manometric data from IIH patients who underwent angioplasty/stenting. All patients had confirmed dural sinus stenosis and had failed maximal medical therapy (MMT). Demographic, clinical, and radiological presentation, as well as long‐term follow‐up outcomes were collected retrospectively. Results: A total of 16 patients who underwent VSS were enrolled in the present study. Demographic data revealed a mean age of 40 (range 20–55), with 69% (11/16) being female, and a mean body mass index (BMI) of 27.05 (range 19.18–38.04) kg/m2. All patients presented with papilledema and visual disturbances. During a median follow‐up period of 47.5 months, 93.75% (15/16) of patients reported improvement in symptoms, although only 37.5% (6/16) experienced complete resolution. Headaches, blurred vision, and amaurosis related to increased pressure improved in 100% (8/8), 81.25% (13/16), and 75% (3/4) of patients, respectively. However, one patient suffered cerebral infarction and secondary epilepsy soon after VSS, and another patient had recurrence of symptoms due to stent wall thrombosis 2 years later. Conclusions: The significance of venous sinus stenosis in the development of IIH may be undervalued. Our study, based on a Chinese case series, affirms the long‐term safety and effectiveness of VSS in treating IIH patients with relatively lower BMI than those from Western countries. [ABSTRACT FROM AUTHOR]

We developed a highly sensitive and stable SERS-active substrate of Au@Ag@Ag core/shell/shell nanorods, formed by encapsulating Au nanorods (Au NRs) into a bilayer silver shell with Raman reporter molecules (4-mercaptobenzoic acid (4-MBA) and thiram) in the shell–shell gap. The core/shell/shell nanostructures demonstrated a high SERS enhancement and easy assembly. The important role of the bilayer silver shell in boosting the SERS intensity and detection sensitivity was revealed by comparing the performances of the Au@Ag@4-MBA@Ag NRs, Au@Ag@4-MBA NRs, and Au@4-MBA NRs. The obtained Au@Ag@4-MBA@Ag NRs exhibited a significantly promoted SERS intensity, which could reach around 2.6 times and 240 times that of the Au@Ag@4-MBA NRs and Au@4-MBA NRs, where the enhancement factor was found to be strongly correlated with the shell thickness. The controllable plasma properties and SERS effect of the Au@Ag@4-MBA@Ag NRs could be optimized by adjusting the dose of silver nitrate. The SERS substrate comprising core/shell/shell nanorods was highly reproducible and stable (retaining 83% SERS intensity after one month). Moreover, the highly sensitive detection of the pesticide thiram with a detection limit as low as 1.74 × 10−9 M was achieved by taking advantage of the great SERS response of the core/shell/shell nanostructures, which was 1–2 orders of magnitude lower than for other SERS substrates. The developed SERS substrate could be readily extended to embed other target analytes into the core/shell/shell nanostructure for novel and sensitive detection. This study could enable fresh approaches toward next-generation ultrasensitive analyte detection. [ABSTRACT FROM AUTHOR]