Bidirectional Lifetime Tuning of Er 1530 nm Emission Induced by Yb.

Wide-range NIR lifetimes of lanthanide ion-doped nanocrystals are highly desired for numerous bioapplications. As one of the most promising NIR emission bands, the lifetime of Er3+ at 1.5 µm can be as long as ∼10 ms and be greatly shortened by increasing the doping level of either activator Er3+ or sensitizer Yb3+. However, the shortened lifetime is mostly accompanied by the quenching effects, highly restraining the light signal intensity. Alternatively, prolonging the lifetime of Er3+ NIR lifetime without luminescence quenching is of vital significance as it raises the upper limit of the lifetime range and maintains the effective signal intensity. In this work, we revealed that Yb3+ can bidirectionally tune the NIR lifetime of Er3+. By introducing Yb3+, in addition to the substantially improved luminescence intensities, the prolonged NIR lifetime can be generated in low-Er3+-doped NaYF4 nanocrystals, while monotonously decreased lifetime appears in Er3+ heavily doped nanocrystals. To investigate the mechanisms of this bidirectional lifetime tuning and meanwhile avoid additional structural influences, the size and morphology of nanocrystals with different doping compositions were controlled to be similar. The decay dynamics of Er3+ NIR emissions of different nanocrystals were simulated to explain the effects of Yb3+. This work provides insights into the manipulation of the NIR lifetime in Er3+/Yb3+-codoped nanocrystals.

Blue and red upconversion color tuning of Tm3+ via pulse excitation based on the thermal effect.

Color-tunable upconversion luminescence has wide prospects for anti-counterfeiting and disease diagnosis/treatment. To date, achieving high-quality tunable red and blue emissions using a single excitation wavelength remains a formidable challenge, due to the large energy difference between the red and blue photons. In this Letter, based on Tm3+ upconversion luminescence, blue dominant and red dominant emissions are generated upon 980-nm excitations using a short and long pulse, respectively. The corresponding color tuning mechanisms are investigated based on the spectral observations. The proposed color tuning strategy is particularly useful for in vivo applications as the red and blue lights play important roles in biological imaging and drug release, respectively.

Discovery of new LXRß agonists as glioblastoma inhibitors.

Discovery and optimization of selective liver X receptor ß (LXRß) agonists are challenging due to the high homology of LXRα and LXRß in the ligand-binding domain. There is only one different residue (Val versus Ile) at the ligand-binding pocket of LXRs. With machine learning methods, we identified pan LXR agonists with a novel scaffold (spiro[pyrrolidine-3,3'-oxindole]). Then, we figured out the mechanism of LXR isoform selectivity from co-crystal structures. Based on the mechanism and the new scaffold, LXRß selective agonists were designed and synthesized. This led to the discovery of LXRß agonists 4-7rr, 4-13 and 4-13rr with IC50 values ranging from 1.78 to 6.36 µM against glioblastoma in vitro. Treatment with 50 mg/kg/day of 4-13 for 15 days significantly reduced tumor growth using an in vivo xenograft glioblastoma model.

Two new lignans from the aerial parts of Saururus chinensis with cytotoxicity toward nasopharyngeal carcinoma.

Two new lignans (1 and 12), together with 15 known compounds (2-11 and 13-17), were isolated from the aerial parts of Saururus chinensis Baill. Their structures were determined through extensive spectroscopic analyses. All the isolates were evaluated for their cytotoxicity against four human nasopharyngeal carcinoma cells (HONE1, CNE1, CNE2, and SUNE1). Compound 13 showed the most potent cytotoxicity toward HONE1, SUNE1, CNE2, and CNE1 cells with IC50 values of 0.76, 5.42, 5.86 and 6.28 µM, respectively. Further studies revealed that compound 13 suppressed cell growth by arresting the cell cycle at the S phase and induced cell apoptosis in the HONE1 cell line.

High-resolution distributed polarization crosstalk measurement for polarization maintaining fiber with considerable dispersion.

We present a high-resolution polarization crosstalk measurement method for polarization maintaining fiber (PMF) with considerable dispersion. The birefringence dispersion of the PMF severely degrades the spatial resolution of the distributed polarization crosstalk measurement. Conventional dispersion compensation methods are effective for modest birefringence dispersion coefficients (for instance, of 0.0014 ps/nm/km). We present an iterative matched filter (IMF) method to cope with the case of considerable birefringence dispersion. We measured the distributed polarization crosstalk of a PMF coil with a birefringence dispersion coefficient of 0.235 ps/nm/km. By applying the IMF method, we obtained a spatial resolution of 0.09 m at any position of the PMF (a maximum of 12.36 m without dispersion compensation).

Simultaneous measurement of displacement and temperature using a PMF-based dual Mach-Zehnder interferometer.

A dual Mach-Zehnder interferometer (MZI) based on polarization-maintaining fiber (PMF) is described for simultaneous measurement of displacement and temperature. Two orthogonal polarization components of a beam are simultaneously transmitted in the interferometer. The sensing configuration contains a short PMF section, a lens, and a mirror. The lens can transmit the slow polarization component and reflect the fast polarization component. Each polarization component exhibits a unique phase shift in response to changes in displacement and temperature, forming a dual MZI. Experimental results show that the resolutions of displacement and temperature are 60 pm and 2×10-3°C, respectively, and measurement ranges of displacement and temperature can reach 20 cm and 70°C. The experimental result demonstrates that there is no crosstalk between displacement and temperature, and high repeatability is demonstrated experimentally. This sensor allows multiparameter measurement, high resolution, wide measurement range, and good repeatability, conferring good application potential.

The Effect of Computed Tomography-Guided 125I Radioactive Particle Implantation in Treating Cancer and Its Pain.

BACKGROUND AND AIM: Pain is a prevalent and serious problem in patients with cancer. This study aimed to investigate the clinical value of the implantation of radioactive particle 125I in treating cancer and its pain. MATERIALS AND METHODS: From February 2014 to February 2015, 38 patients with malignant tumor received computed tomography (CT)-guided 125I radioactive particle implantation to treat cancer pain in this hospital. Before surgery, the lesions were calculated by brachytherapy treatment planning system (TPS) to get the local number of particles that are required for implantation. For a period after implantation, TPS was used again to assess the effect of treatment. The 38 patients received 6-month follow-up, and the CT scan was used to evaluate the local tumor. The visual analogue scale (VAS) was used to assess the pain. RESULTS: The curative effect was evaluated at postoperative 2, 4, and 6 months, and the curative effect was 34.2%, 73.68%, and 89.47%, respectively. The preoperative VAS score of the 38 patients was 5.48 ± 2.50 (13 cases of mild pain, 19 cases of moderate pain, and 6 cases of severe pain), and their pain was improved in different degrees after operation. CONCLUSIONS: CT-guided 125I radioactive particle implantation is a safe and effective treatment for cancer and its pain.

Suppression of interference noise caused by Fresnel reflection in all-fiber white-light interferometer.

We propose methods to suppress the interference noise (IN) of an all-fiber white-light interferometer (WLI), which is caused by the residual Fresnel reflective beam. The methods are proposed to ensure a wide dynamic range and enhance the accuracy of measurement. IN can cause misjudgment of the realistic optical characteristic parameters, such as the fault diagnosis and polarization coupling of the optical devices under test. In addition, IN can reduce the dynamic range of the WLI. The optical path mismatch (OPM) method and the intensity suppression (IS) method by changing the positions and intensity of the IN are presented. The two suppression methods can successfully restrain IN caused by the Fresnel reflection beams. The experimental results show that IN is successfully suppressed by the OPM method or restrained by IS method in interferograms, and the dynamic range can achieve 85 dB without IN.

Curative effect of transcatheter arterial chemoembolization combined with radiofrequency ablation in treating hepatic cell carcinoma and its effect on serum markers.

BACKGROUND: Hepatic cell carcinoma (HCC) is more common in clinical practice, and has high malignant degree. OBJECTIVE: This study aims to analyze the curative effect of transcatheter arterial chemoembolization (TACE) combined with radiofrequency ablation (RFA) in treating hepatic cell carcinoma (HCC) and its effect on serum markers. METHODS: A total of 106 cases of patients with hepatic cell carcinoma treated in our hospital were randomly divided into two groups: observation group and control group. Patients in the observation group (53 cases) received transcatheter arterial chemoembolization combined with radiofrequency ablation therapy, while subjects in the control group (53 cases) received transcatheter arterial chemoembolization therapy. Differences in the overall effect, indicators of inflammation and oxidative stress, tumor activity-related indicators and tumor recurrence-related indicators between these two groups were compared. RESULTS: At one and two weeks after treatment, the number of cases of CR and PR in the observation group was higher than that in the control group, the number of cases of SD was not different from that in the control group, and the number of cases of PD was lower than that in the control group. At two weeks after treatment, differences in serum MDA, SOD, GSH, CRP, TNF-α and ESR between the two groups were significant. However, serum EC, VEGF, MMP, AFP, CA199 and GGT content was significantly lower in the observation group than that in the control group. CONCLUTIONS: Transcatheter arterial chemoembolization combined with radiofrequency ablation therapy can effectively control the growth of liver cancer lesions, reduce the levels of tumor-related serum markers, and inhibit the activity of tumor cells.

Comparison of efficacy between TACE combined with apatinib and TACE alone in the treatment of intermediate and advanced hepatocellular carcinoma: A single-center randomized controlled trial.

OBJECTIVE: This study was designed to compare the clinical efficacy and safety of transcatheter arterial chemoembolization (TACE) combined with apatinib and TACE alone in the treatment of intermediate and advanced hepatocellular carcinoma (HCC). METHODS: From March 2015 to August 2015, a total of 44 patients with moderate and advanced HCC, who were admitted in the Navy General Hospital of China, were included into this study. These patients were randomly divided into 2 groups: group A and group B. Patients in group A underwent TACE alone, while patients in group B underwent the combined treatment of TACE with apatinib. Differences in preoperative general data between these 2 groups were not statistically significant (P > 0.05). All patients were followed up for 12-18 months. Changes in α-fetal protein (AFP) at 3 months after treatment and the objective response rate (ORR) at 3, 6, 9 and 12 months after treatment were compared between these 2 groups. Furthermore, progression-free survival (PFS) and the incidence of adverse reactions were also compared between these 2 groups. RESULTS: AFP levels in groups A and B significantly decreased after 3 months of treatment, compared with the levels before treatment, and the differences were statistically significant (P < 0.05). However, at 3 months after treatment, the difference between these 2 groups was not statistically significant (P > 0.05). ORR at 3, 6, 9 and 12 months after treatment was 36.36%, 27.27%, 13.64% and 9.09%, respectively, in group A; and 60%, 50%, 45% and 35%, respectively, in group B. At 3 and 6 months after treatment, the differences between these 2 groups were not statistically significant (P > 0.05); while at 9 and 12 months after treatment, the differences between these 2 groups were statistically significant (P < 0.05). The median PFS was 6.0 months in group A and 12.5 months in group B, and the difference was statistically significant (P < 0.05). The incidences of complications were related to oral apatinib, such as hypertension, hand-foot syndrome and proteinuria, were higher in group B than in group A, and the differences were statistically significant (P < 0.05). These symptoms all alleviated after symptomatic treatments. CONCLUSIONS: For intermediate and advanced HCC, the long-term curative effect of TACE combined with apatinib is better than that of TACE alone. The former can obviously prolong the PFS of patients and has a confirmed safety.

Unloading Characteristics of Sand-drift in Wind-shallow Areas along Railway and the Effect of Sand Removal by Force of Wind.

Wind-shield walls decrease the velocity of wind-drift sand flow in transit. This results in sand accumulating in the wind-shadow zone of both windshield wall and track line, causing severe sand sediment hazard. This study reveals the characteristics of sand accumulation and the laws of wind-blown sand removal in the wind-shadow areas of three different types of windshield walls, utilizing three-dimensional numerical simulations and wind tunnel experiments and on-site sand sediment tests. The results revealed the formation of apparent vortex and acceleration zones on the leeward side of solid windshield walls. For uniform openings, the vortex area moved back and narrowed. When bottom-opening windshield walls were adopted, the track-supporting layer at the step became a conflux acceleration zone, forming a low velocity vortex zone near the track line. At high wind speeds, windshield walls with bottom-openings achieved improved sand dredging. Considering hydrodynamic mechanisms, the flow field structure on the leeward side of different types of windshield structures is a result of convergence and diffusion of fluids caused by an obstacle. This convergence and diffusion effect of air fluid is more apparent at high wind velocities, but not obvious at low wind velocities.

Combination therapy for scalp angiosarcoma using bevacizumab and chemotherapy: a case report and review of literature.

Bevacizumab, an angiogenesis inhibitor, is a recombined humanized monoclonal antibody against vascular endothelial growth factor and a promising therapeutic option for angiosarcoma management. This is a case report and review of the literature using bevacizumab and combination chemotherapy for angiosarcoma. The understanding of the effectiveness of combined therapy of bevacizumab and chemotherapy agents is still limited. The benefits of bevacizumab treatment for angiosarcoma will need to be weighed against the risks of venous thromboembolism in this population.

Chemical constituents of Swertia yunnanensis and their anti-hepatitis B virus activity.

Four new triterpenoids, sweriyunnangenin A (1), sweriyunnanosides A (2), B (3) and C (4), along with nineteen known compounds (5-23) were isolated from Swertia yunnanensis. Based on extensive spectroscopic analyses (1D- and 2D-NMR, HRESIMS, UV, IR, [α]D), the structures of sweriyunnangenin A (1), sweriyunnanosides A (2), B (3) and C (4) were elucidated as taraxer-14-ene-3α,6ß-diol, oleanolic acid 28-O-ß-D-glucopyranosyl-(1→2)-O-ß-D-glucopyranoside, 2α,3ß-di-hydroxyolean-12-en-28-oic acid 28-O-ß-D-glucopyranosyl(1→6)-ß-D-glucopyranosyl (1→6)-ß-D-glucopyranosyl(1→2)-ß-D-glucopyranoside and hederagenin 28-O-ß-D-glucopyranosyl(1→6)-ß-D-glucopyranosyl(1→6)-ß-D-glucopyranosyl(1→2)-ß-D-glucopyranoside, respectively. Twenty-two compounds were evaluated for their anti-HBV activities on the HepG 2.2.15 cell line in vitro, of which nine compounds showed potent anti-HBV activities. Compounds 1, 5-6, 14-16 and 19 showed activities against the secretion of HBsAg (IC50 values from 0.10 to 1.76 mM) and HBeAg (IC50 values from 0.04 to 1.41 mM), and compounds 11 and 13-16 exhibited significant inhibition on HBV DNA replication (IC50 values from 0.01 to 0.09 mM).

Seven new secoiridoids with anti-hepatitis B virus activity from Swertia angustifolia.

Seven new secoiridoids, swertianglide (1) and swertianosides A-F (2-7), together with fifteen known compounds, were isolated from the whole plants of Swertia angustifolia. Their structures were elucidated on the basis of extensive spectroscopic analyses ([α](D), UV, IR, MS, 1D- and 2D-NMR). Fourteen compounds were evaluated for their anti-hepatitis B virus (HBV) activities on the Hep G 2.2.15 cell line in vitro. Compound 2, an unusual secoiridoid glycoside dimer, showed significant activities inhibiting the secretion of HBsAg (IC50 0.18 mM, SI 3.11) and HBeAg (IC50 0.12 mM, SI 4.67).

[Chemical constituents of Swertia hispidicalyx].

OBJECTIVE: To study the chemical constituents of Swertia hispidicalyx. METHOD: The EtOAc part of S. hispidicalyx was chromatographied by various column chromatography methods, and the isolates were identified based on spectroscopic analyses (MS, 1H-and 13C-NMR). RESULT: Eleven compounds were isolated from S. hispidicalyx and characterized as 1,3,5,8-tetrahydroxyxanthone (1), 1,5,8-trihydroxy-3-methoxyxanthone (2), gentiolactone (3), swertiamarin (4), 3,4-dihydro-1H,6H,8H-naphtho [1, 2-c:4, 5-c', d'] dipyrano-1,8-dione (5), (+)-syringaresinol (6), trans-coniferyl aldehyde (7), maslinic acid (8), oleanolic acid (9), daucosterol (10), and -sitosterol (11). CONCLUSION: Compounds 1-11 were obtained from S. hispidicalyx for the first time.