Universal relation between the conditional auto-correlation function and the cross-correlation function of biphotons.

We systematically studied the relation between the conditional auto-correlation function (CACF) and cross-correlation function (CCF) of biphotons or pairs of single photons. The biphotons were generated from a heated atomic vapor via the spontaneous four-wave mixing (SFWM) process. In practical usage, one single photon of a pair is utilized as the heralding photon, and another is employed as the heralded photon. Motivated by the data of CACF of the heralded photons versus CCF, we proposed a universal formula to predict the CACF. The derived formula was based on general theory and is also valid for the biphoton generation process of spontaneous parametric down-conversion (SPDC). With the formula, we utilized the experimentally determined parameters to predict CACFs, which can well agree with the measured CACFs. The proposed formula enables one to quantitatively know the CACF of heralded single photons without the measurement of Hanbury-Brown-Twiss-type three-fold coincidence count. This study provides a better understanding of biphoton generation using the SFWM or SPDC process. Our work demonstrates a valuable tool for analyzing a vital property of how the heralded photons are close to Fock-state single photons.

Hemoglobin loss method calculates blood loss during pancreaticoduodenectomy and predicts bleeding-related risk factors.

BACKGROUND: The common clinical method to evaluate blood loss during pancreaticoduodenectomy (PD) is visual inspection, but most scholars believe that this method is extremely subjective and inaccurate. Currently, there is no accurate, objective method to evaluate the amount of blood loss in PD patients. AIM: The hemoglobin (Hb) loss method was used to analyze the amount of blood loss during PD, which was compared with the blood loss estimated by traditional visual methods. The risk factors for bleeding were also predicted at the same time. METHODS: We retrospectively analyzed the clinical data of 341 patients who underwent PD in Shandong Provincial Hospital from March 2017 to February 2019. According to different surgical methods, they were divided into an open PD (OPD) group and a laparoscopic PD (LPD) group. The differences and correlations between the intraoperative estimation of blood loss (IEBL) obtained by visual inspection and the intraoperative calculation of blood loss (ICBL) obtained using the Hb loss method were analyzed. ICBL, IEBL and perioperative calculation of blood loss (PCBL) were compared between the two groups, and single-factor regression analysis was performed. RESULTS: There was no statistically significant difference in the preoperative general patient information between the two groups (P > 0.05). PD had an ICBL of 743.2 (393.0, 1173.1) mL and an IEBL of 100.0 (50.0, 300.0) mL (P < 0.001). There was also a certain correlation between the two (r = 0.312, P < 0.001). Single-factor analysis of ICBL showed that a history of diabetes [95% confidence interval (CI): 53.82-549.62; P = 0.017] was an independent risk factor for ICBL. In addition, the single-factor analysis of PCBL showed that body mass index (BMI) (95%CI: 0.62-76.75; P = 0.046) and preoperative total bilirubin > 200 µmol/L (95%CI: 7.09-644.26; P = 0.045) were independent risk factors for PCBL. The ICBLs of the LPD group and OPD group were 767.7 (435.4, 1249.0) mL and 663.8 (347.7, 1138.2) mL, respectively (P > 0.05). The IEBL of the LPD group 200.0 (50.0, 200.0) mL was slightly greater than that of the OPD group 100.0 (50.0, 300.0) mL (P > 0.05). PCBL was greater in the LPD group than the OPD group [1061.6 (612.3, 1632.3) mL vs 806.1 (375.9, 1347.6) mL] (P < 0.05). CONCLUSION: The ICBL in patients who underwent PD was greater than the IEBL, but there is a certain correlation between the two. The Hb loss method can be used to evaluate intraoperative blood loss. A history of diabetes, preoperative bilirubin > 200 µmol/L and high BMI increase the patient's risk of bleeding.

Luminescence Enhancement and Temperature Sensing Properties of Hybrid Bismuth Halides Achieved via Tuning Organic Cations.

Bismuth-halide-based inorganic-organic hybrid materials (Bi-IOHMs) are desirable in luminescence-related applications due to their advantages such as low toxicity and chemical stability. Herein, two Bi-IOHMs of [Bpy][BiCl4(Phen)] (1, Bpy = N-butylpyridinium, Phen = 1,10-phenanthroline) and [PP14][BiCl4(Phen)]·0.25H2O (2, PP14 = N-butyl-N-methylpiperidinium), containing different ionic liquid cations and same anionic units, have been synthesized and characterized. Single-crystal X-ray diffraction reveals that compounds 1 and 2 crystallize in the monoclinic space group of P21/c and P21, respectively. They both possess zero-dimensional ionic structures and exhibit phosphorescence at room temperature upon excitation of UV light (375 nm for 1, 390 nm for 2), with microsecond lifetime (24.13 µs for 1 and 95.37 µs for 2). Hirshfeld surface analysis has been utilized to visually exhibit the different packing motifs and intermolecular interactions in 1 and 2. The variation in ionic liquids makes compound 2 have a more rigid supramolecular structure than 1, resulting in a significant enhancement in photoluminescence quantum yield (PLQY), that is, 0.68% for 1 and 33.24% for 2. In addition, the ratio of the emission intensities for compounds 1 and 2 shows a correlation with temperature. This work provides new insight into luminescence enhancement and temperature sensing applications involving Bi-IOHMs.

Isolation, structure elucidation, and high-performance liquid chromatography quantification of photolytic degradation impurities in acrivastine.

Acrivastine is a second-generation H1-receptor antagonist, and its structure is sensitive to ultraviolet. Four unknown and one reported degradation products can be detected in the ultraviolet radiation solutions of acrivastine. To improve the quality control of acrivastine, the photodegradation impurities were isolated and structurally elucidated. There are four new impurities (1-3 and 5), and one reported compound (4). The isolation strategy was designed as preparative high-performance liquid chromatography using a reversed phase column with volatile acid addition in the mobile phase, combined with preparative thin-layer chromatography using silica gel with alkaline addition in the mobile phase. Using the developed methods, five impurities (1-5) were efficiently purified after two or three chromatography runs with purities > 95%. The structures of compounds 1-5 are elucidated based on spectroscopy analysis of MS, and nuclear magnetic resonance spectroscopy. Using the impurity standard, the high-performance liquid chromatography method was developed and validated. The method was proved to be sensitive, accurate (Recovery% 96.1-107.7%), linear (0.15-0.75 µg/mL, R2 > 0.996), robust, and specific, and it was successfully used to determine the degradation impurities of acrivastine and its formulation.

Direct Three-Dimensional Visualization of Membrane Fouling by Confocal Laser Scanning Microscopy.

Membrane-based separation is an important technique for removing emulsified oil from water. However, the mechanisms of fouling are complex because of the deformability and potential for coalescence and break-up of the oil droplets. Here, we report for the first time direct, three-dimensional (3D) visualization of oil droplets on electrospun fiber microfiltration membranes after a period of membrane-based separation of oil-in-water emulsions. High-resolution 3D images were acquired by a dual-channel confocal laser scanning microscopy (CLSM) technique in which both the fibers and the oil (dodecane) were fluorescently labeled. The morphology of dodecane as the foulant was observed for two different types of fibers, an oleophobic nylon (PA6(3)T), and oleophilic polyvinylidene fluoride (PVDF). Through direct visualization, the rejected oil was found to form droplets of clam-shell shape on the PA6(3)T fibers, whereas the oil tended to wet the PVDF fibers and spread across the membrane. The morphology was also analyzed as a function of separation time (i.e., "4D" imaging), as the oil accumulated within and upon the membranes. The observations are qualitatively consistent with a transition from blocking of individual pores in the membrane to coalescence of oil droplets into coherent liquid films with increasing filtration time. Analysis of permeate flux using blocking filtration models corroborate the transition of fouling modes indicated by the 3D images. This direct, 3D visualization CLSM technique is a powerful tool for characterizing the mechanisms of fouling in membranes used for liquid emulsion separations.

Comparison of biofunctional activity of Asparagus cochinchinensis (Lour.) Merr. Extract before and after fermentation with Aspergillus oryzae.

Asparagus cochinchinensis root (ACR) is used in traditional Chinese medicine. In this study, ACR was first extracted with 25% ethyl acetate (EA) and then fermented by Aspergillus oryzae to enhance its antioxidant activity and evaluate its potential antityrosinase activity. The physiological activity and cytotoxicity of A. oryzae-fermented ACR extract, along with its antityrosinase activity and effects on melanogenic factor levels in human epidermal melanocytes (HEMs), were analyzed and compared with those of the unfermented extract. The results showed that the physiological activity of the fermented extract in vitro or in cells was significantly higher than that of the unfermented extract. The IC50 values for 2,2-diphenyl-1-picrylhydrazine radical scavenging activity, reducing power, and antityrosinase activity in vitro for the fermented extract were 250.6 ± 32.5, 25.7 ± 3.5, and 50.6 ± 3.1 mg/L, respectively. The fermented extract favored cellular antityrosinase activity with low melanin production in human melanoma cells compared with the unfermented extract. The inhibitory mechanism of melanin synthesis by unfermented extract was independent of the tested melanogenesis-related proteins. However, the inhibitory mechanism of the fermented extract was possibly caused by synergistic inhibition of these proteins. Thus, A. oryzae-fermented ACR extract may be used for developing new health food or cosmetic ingredients.

WO3 Nanofiber-Based Biomarker Detectors Enabled by Protein-Encapsulated Catalyst Self-Assembled on Polystyrene Colloid Templates.

A novel catalyst functionalization method, based on protein-encapsulated metallic nanoparticles (NPs) and their self-assembly on polystyrene (PS) colloid templates, is used to form catalyst-loaded porous WO3 nanofibers (NFs). The metallic NPs, composed of Au, Pd, or Pt, are encapsulated within a protein cage, i.e., apoferritin, to form unagglomerated monodispersed particles with diameters of less than 5 nm. The catalytic NPs maintain their nanoscale size, even following high-temperature heat-treatment during synthesis, which is attributed to the discrete self-assembly of NPs on PS colloid templates. In addition, the PS templates generate open pores on the electrospun WO3 NFs, facilitating gas molecule transport into the sensing layers and promoting active surface reactions. As a result, the Au and Pd NP-loaded porous WO3 NFs show superior sensitivity toward hydrogen sulfide, as evidenced by responses (R(air)/R(gas)) of 11.1 and 43.5 at 350 °C, respectively. These responses represent 1.8- and 7.1-fold improvements compared to that of dense WO3 NFs (R(air)/R(gas) = 6.1). Moreover, Pt NP-loaded porous WO3 NFs exhibit high acetone sensitivity with response of 28.9. These results demonstrate a novel catalyst loading method, in which small NPs are well-dispersed within the pores of WO3 NFs, that is applicable to high sensitivity breath sensors.

Morphology, molecular stacking, dynamics and device performance correlations of vacuum-deposited small-molecule organic solar cells.

The "all carbon" organic solar cells (OSCs) based on the homocyclic molecule tetraphenyldibenzoperiflanthene (DBP) as a donor and C60 as an acceptor were comprehensively characterized. The optimized planar-mixed heterojunction device with a DBP:C60 mixture ratio of DBP : C60 (1 : 2) exhibited a power conversion efficiency of 4.47%. To understand why DBP possesses such advantageous characteristics, the correlations of the morphology, molecular stacking, carrier dynamics and performance of DBP:fullerene-based devices have been systematically studied. First, the face-on stacked DBP molecules could enhance both the absorption of light and the charge carrier mobility. Second, DBP : C60 (1 : 2) thin films with optimized domain sizes and partially interconnected acceptor grains led to the most balanced carrier mobility and the lowest bimolecular recombination in devices. Finally, the DBP molecules were found to stack closely using grazing incidence wide-angle X-ray scattering measurements, with a π-π stacking spacing of 4.58 Å, indicating an effective molecular orbital overlap in DBP. The study not only reveals the promising characteristics of DBP as a donor in OSCs but the clear correlations of the thin-film nano-morphology, molecular stacking, carrier mobility and charge recombination found here could also provide insights into the characterization methodology and optimization of the small molecule OSCs.

[Efficacy of Peg-interferon alpha-2a combinated with entecavir on HBeAg positive chronic hepatitis B patients with high serum hepatitis B viral loads].

OBJECTIVE: This study aimed at evaluating the efficacy and safety of a combination treatment of entecavir and Peginterferon alpha-2a for HBeAg positive chronic hepatitis B patients with high serum hepatitis B viral loads. METHODS: 60 treatment-naive HBeAg-positive CHB patients with high serum hepatitis B viral loads were enrolled and randomly divided into three groups: group A received Peginterferon alpha-2a monotherapy for 48 weeks (n = 20); group B received entecavir monotherapy for more than 48 weeks (n = 20); group C received Peginterferona alpha-2a combined with entecavir for 12 weeks, then Peginterferon alpha-2a monotherapy for 36 weeks (n = 20). Virological response, ALT normalization, HBeAg and HBsAg seroclearance rate were analysed at the end of 4, 12 and 24 weeks after the treatment. RESULTS: The ratio of undetectable hepatitis B virus (HBV) DNA were 50% and 10%, 95% and 25% and 100% and 30% in group C and group A respectively, 50% and 20%, 95% and 75% and 100% and 90% in group C and group B respectively at the end of 4, 12 and 24 weeks of treatment. The differences were significant between group C and A (Z = -4.6, P < 0.001), group C and B (Z = -2.53, P = 0.0114). ALT normalization rate was significantly lower in group A than that of group C (Z = -2.63, P = 0.0086). HBeAg levels declined more in group C than the other two groups after 24 weeks of treatment. CONCLUSIONS: For HBeAg positive chronic hepatitis B patients with high serum hepatitis B viral loads, combination treament of Peginterferon alpha-2a with entecavir is more effective than Peginterferon alpha-2a monotherapy in virologic response and ALT normalization after 24 weeks of treatment.

Origins of device performance in dicarboxyterpyridine Ru(II) dye-sensitized solar cells.

This study carefully examines carrier dynamics in highly efficient dye-sensitized solar cells (DSSCs) based on a series of recently developed dicarboxyterpyridine Ru(II) dyes (PRT-11-15). Comprehensive spectral response analyses, transient photovoltage and photocurrent measurements, and transient absorption techniques are exploited to investigate the effects of various functionalized terpyridines on carrier injection efficiency (η(inj)), electron diffusion length (L) and dye-regeneration efficiency (η(reg)). The resulting parameters are fully comprehended, which are then correlated with the origins of the device performance such as short circuit current density J(sc), open circuit voltage V(oc) and hence the overall conversion efficiency η in these Ru(II) based DSSCs.