Search

Inorganic materials with short radiative decay time are highly desirable for fast optical sensors. This paper reports fast photoluminescence (PL) from a series of barium hexafluorosilicate (BaSiF6) superlong nanowires with high aspect ratios, codoped with Ce3+/Tb3+/Eu3+ ions, with a subnanosecond decay time. Solvothermally synthesized BaSiF6 nanowires exhibit a uniform morphology, with an average diameter less than 40 nm and aspect ratios of over several hundreds, grown in the c-axis direction with {110} surfaces. The PL emission from the codoped BaSiF6 nanowires, when excited by a 254 nm source, is dependent on Tb3+ concentration, and the energy transfer from Ce3+ to Tb3+ and to Eu3+ ions allows efficient emissions in the visible spectra when excited by a near UV source. Annealing BaSiF6 nanowires at 600 °C in a vacuum produced barium fluoride (BaF2) nanowires composed of nanocrystals. Both BaSiF6 and BaF2 nanowires exhibit fast emissions in the visible spectra, with enhanced intensities compared with their codoped microparticle counterparts. The decay time of codoped BaSiF6 nanowires is found to be shorter than that of codoped BaF2 nanowires. The energy transfer is also observed in their cathodoluminescence spectra with high-energy irradiation. [ABSTRACT FROM AUTHOR]

By adopting the development method and diagnostic architecture of automotive open system architecture standard AUTOSAR, an automotive electronic fault diagnostic system based on Freescale HCS12X processor is developed and corresponding simulation experiments are conducted. The results show that the system can timely and accurately diagnose malfunctions, and the AUTOSAR-based diagnostic system is configurable and can adapt to a variety of situations. [ABSTRACT FROM AUTHOR]

Hierarchical domain structures associated with oxygen octahedra tilting patterns were observed in lead-free (Bi1/2Na1/2)TiO3 ceramics using aberration-corrected high-resolution transmission electron microscopy (HRTEM). Three types of domains are induced by distinct mechanisms: the 'orientation-domain' is induced at micrometer scale formed by different tilting orientations of the oxygen octahedra, the 'meso-chemical-domain' occurs at a few tens of nanometer scale by chemical composition variation on the A-site in the ABO3 perovskite structure, and the 'nano-cluster-region' runs across several unit-cells with apparent A-site cation segregation with oxygen vacancies clustering around Na cations. Based on HRTEM amplitude contrast imaging (ACI), the correlation between the oxygen octahedral tilting pattern and compositional non-stoichiometry was established. The role of the hierarchical domain structure associated with the tilting patterns of the oxygen octahedra on the ferroelectric behavior of (Bi1/2Na1/2)TiO3 is also discussed. [ABSTRACT FROM AUTHOR]

For many chemical reactions, it remains notoriously difficult to predict and experimentally determine the rates and branching ratios between different reaction channels. This is particularly the case for reactions involving short-lived intermediates, whose observation requires ultrafast methods. The UV photochemistry of bromoform (CHBr 3 ) is among the most intensely studied photoreactions. Yet, a detailed understanding of the chemical pathways leading to the production of atomic Br and molecular Br 2 fragments has proven challenging. In particular, the role of isomerization and/or roaming and their competition with direct C-Br bond scission has been a matter of continued debate. Here, gas-phase ultrafast megaelectronvolt electron diffraction (MeV-UED) is used to directly study structural dynamics in bromoform after single 267 nm photon excitation with femtosecond temporal resolution. The results show unambiguously that isomerization contributes significantly to the early stages of the UV photochemistry of bromoform. In addition to direct C-Br bond breaking within <200 fs, formation of iso-CHBr 3 (Br-CH-Br-Br) is observed on the same time scale and with an isomer lifetime of >1.1 ps. The branching ratio between direct dissociation and isomerization is determined to be 0.4 ± 0.2:0.6 ± 0.2, i.e., approximately 60% of molecules undergo isomerization within the first few hundred femtoseconds after UV excitation. The structure and time of formation of iso-CHBr 3 compare favorably with the results of an ab initio molecular dynamics simulation. The lifetime and interatomic distances of the isomer are consistent with the involvement of a roaming reaction mechanism.

Pulsed field ablation (PFA), a nonthermal ablative mechanism, has been proven to be effective and safe in clinical application. To date, PFA has been used for only atrial fibrillation (AF) ablation in limited clinical trials. The present study describes a case of paroxysmal AF in which mitral and cavotricuspid isthmus (CTI)-dependent atrial flutter was discovered incidentally during PFA operation and successfully ablated with PFA. This is the first medical record of PFA for AF combined with mitral and CTI atrial flutter. The present case report revealed that PFA can be independently used to treat complex arrhythmias, similar to radiofrequency (RF) ablation, without the need for assistance from other ablation methods. Concurrently, the present study, to the best of the authors' knowledge is the first to report a case using a point-to-point PFA ablation strategy for isthmus ablation. This highlights the potential of PFA in treating diverse arrhythmias across different regions, such as the mitral isthmus and other intricate areas, utilizing a point-to-point PFA ablation strategy., Competing Interests: The authors declare that they have no competing interests., (Copyright: © 2024 He et al.)

By designing a liquid crystal cell with comb electrode structure, the alignment modulation of nematic liquid crystal in the cell can be realized after the electric field is applied. In different orientation regions, the incident laser beam can deflect at different angles. At the same time, by changing the incident angle of the laser beam, the reflection modulation of the laser beam on the interface of the liquid crystal molecular orientation change can be realized. Based on the above discussion, we then demonstrate the modulation of liquid crystal molecular orientation arrays on nematicon pairs. In different orientation regions of liquid crystal molecules, nematicon pairs can exhibit various combinations of deflections, and these deflection angles are modulable under external fields. Deflection and modulation of nematicon pairs have potential applications in optical routing and optical communication.

Hierarchical domain structures associated with oxygen octahedra tilting patterns were observed in lead-free (Bi 1/2 Na 1/2 )TiO 3 ceramics using aberration-corrected high-resolution transmission electron microscopy (HRTEM). Three types of domains are induced by distinct mechanisms: the 'orientation-domain' is induced at micrometer scale formed by different tilting orientations of the oxygen octahedra, the 'meso-chemical-domain' occurs at a few tens of nanometer scale by chemical composition variation on the A-site in the ABO 3 perovskite structure, and the 'nano-cluster-region' runs across several unit-cells with apparent A-site cation segregation with oxygen vacancies clustering around Na cations. Based on HRTEM amplitude contrast imaging (ACI), the correlation between the oxygen octahedral tilting pattern and compositional non-stoichiometry was established. The role of the hierarchical domain structure associated with the tilting patterns of the oxygen octahedra on the ferroelectric behavior of (Bi 1/2 Na 1/2 )TiO 3 is also discussed., (© 2022 IOP Publishing Ltd.)

Vertically stacked transition metal dichalcogenide-graphene heterostructures provide a platform for novel optoelectronic applications with high photoresponse speeds. Photoinduced nonequilibrium carrier and lattice dynamics in such heterostructures underlie these applications but have not been understood. In particular, the dependence of these photoresponses on the twist angle, a key tuning parameter, remains elusive. Here, using ultrafast electron diffraction, we report the simultaneous visualization of charge transfer and electron-phonon coupling in MoS 2 -graphene heterostructures with different stacking configurations. We find that the charge transfer timescale from MoS 2 to graphene varies strongly with twist angle, becoming faster for smaller twist angles, and show that the relaxation timescale is significantly shorter in a heterostructure as compared to a monolayer. These findings illustrate that twist angle constitutes an additional tuning knob for interlayer charge transfer in heterobilayers and deepen our understanding of fundamental photophysical processes in heterostructures, of importance for future applications in optoelectronics and light harvesting.

Aim: We present the long-term outcomes as well as their correlation with tumor size in 127 consecutive patients harboring large MSWM after microsurgical treatment., Material and Methods: The retrospective analysis of clinical data and follow-up data of 127 microsurgical treated patients with MSWM was performed. The mean maximum diameter of tumors was 5.2cm (ranged 1.5-10.0cm)., Results: 104 cases (81.9%) achieved gross total resection. There was no operative mortality. Detailed follow-up data was available in 120 cases for a mean duration of 81.6 months (12-216 months). The permanent morbidity was 14.2%. The mean KPS score 1 year after surgery was 90.6 (ranged 60-100). Among 74 patients of preoperative visual acuity (VA) impairment, postoperative VA improved in 42 cases (56.8%), unchanged in 30 (40.5%), and deteriorated in 2 (2.7%). MR images revealed tumor recurrence after total resection in 10 cases (10.2%) and tumor progression after subtotal resection in 10 cases (45.5%)., Conclusion: Tumor recurrence was the major risk in the long run, thus the initial surgery was extremely important and hence should be aggressive. The size of tumor affected the extent of tumor removal determining clinical outcomes including VA improvement and KPS score immediately after surgery; however, it was not correlated with long-term overall outcomes.

Aim: To explore the expansion and differentiation of hepatocytoid cell induced from myeloid mesenchymal stem cell (MSC) in vitro, in order to find suitable resource of hepatocytes for bioartificial liver or liver transplantation., Methods: The rat myeloid MSC was isolated and divided into three groups which were cultured by Friedensteion method, and then were induced by culture fluid, culture fluid plus cholestatic serum and culture fluid plus hepatocyte growth factor (HGF), respectively. Hepatocytoid cell as well as expression of CK18 and AFP was observed by immunohistochemistry., Results: After the induction for 21 d, hepatocytoid cell was observed, and its expression of CK18 and AFP was detected by immunohistochemistry in MSC cultured with cholestatic serum. Furthermore, on the 35th d, albumin mRNA was expressed in the cell, suggesting the inducing effect was similar to that by HGF., Conclusion: Rat myeloid MSC can differentiate into hepatocyte lineage under appropriate condition. This method is easy to operate.

Objective: To investigate the effect of Chinese traditional medicine heluoshugan capsule on liver fibrosis induced by Schistosoma japonicum infection in mice., Methods: Liver fibrosis in mice was established by Schistosoma japonicum infection in 6 weeks. Suspension of heluoshugan prepared with normal saline was given orally to the mice, 2 capsules for 20 mice daily for 8 weeks. The level of vascular endothelial growth factor (VEGF), focal adhesion kinase (FAK) and type I, III collagen in liver tissue were detected by immuno-histochemistry., Results: The results showed that heluoshugan improved the pathological change of the liver tissue, decreased the level of type I, III collagen, especially type III collagen (P < 0.01). The level of VEGF and FAK expression was inhibited after the administration of heluoshugan, though the level usually increased in liver fibrosis due to the infection., Conclusions: The result suggests that heluoshugan capsule might have therapeutic effect on liver fibrosis induced by the infection of Schistosoma japonicum in mice, by inhibiting the activation of hepatic stellate cells and the pathological change of liver blood vessel.

Objective: To study the expression of hepatic Bcl-2 and Bax proteins in mice infected with Schistosoma japonicum and the role of pentoxifylline (PTX) in the expression., Methods: Forty mice were randomly divided into 4 groups: one normal control group,mice in the other three groups were all infected each with 25 cercariae, the infected control group was fed for 10 weeks after infection, and 2 weeks after infection, the high dose PTX group was given PTX 360 mg/(kg x d) for 8 weeks and the low dose PTX group was given PTX 180 mg/(kg x d)also for 8 weeks. At the end of 10 weeks all the mice were killed. Bcl-2 and Bax proteins expression was detected by immunohistochemisty., Results: Compared with the normal control group, the expression of Bcl-2 and Bax was significantly higher in the infected control group (P < 0.05). Bcl-2 was significantly higher in high (dose PTX group than in the infected control group and in low dose PTX group (P < 0.05). However there was no significant difference in the expression of Bax among the groups (P > 0.05)., Conclusion: PTX treatment can significantly increase the expression of Bcl-2 in liver tissue of schistosome-infected mice in a dose-dependent manner, and may play a role against liver inflammation and schistosomiasis-related liver fibrosis.

Objective: To establish hepatitis C virus (HCV) infected cell model which is similar to the infection in vivo and can support HCV to replicate for a long time., Methods: After infected with HCV-positive serum, Hep G2 cells were cultured for 60 days. Nested RT-PCR was used to detect plus and minus HCV RNA in cultured cells and supernatants., Results: Plus HCV RNA was detected intermittently in Hep G2 cells during 2-30 days, minus HCV RNA was detected during 3-30 days after infection, the detection rate was similar to plus HCV RNA. Plus and minus HCV RNA can be still intermittently detected during 31-60 days after infection. However, the detection rate gradually declined. Plus HCV RNA was also found intermittently positive in the supernatant, and the detection rate was consistent to that in cells. Minus HCV RNA was not detected in the supernatant., Conclusion: Hep G2 cells were susceptible to HCV, and could support HCV to replicate for a relatively long time. Hep G2 is an ideal HCV infection cell model.

Background: The mortality rate of heavy type hepatitis is high. No special treatment is available except general treatment. This multicenter clinical study was designed to observe the safety and efficacy of promoting hepatic growth factor (PHGF) in the treatment of heavy type hepatitis and severe chronic hepatitis., Methods: 347 patients with heavy type hepatitis and 324 with severe chronic hepatitis were subjected to administration of 120 microg of PHGF per day for 4 weeks on the basis of general treatment. Those who were being effectively treated would last additional 2 to 4 weeks. Blood routine, urine routine, blood urea nitrogen (BUN), blood creatinine (Cr), blood ammonia, alpha fetoprotein (AFP), electrolyte, alanine transaminase (ALT), aspartate transaminase (AST), serum total bilirubin (TBIL), serum direct bilirubin (DBIL), prothrombin time activity (PTA), total protein (TP) and albumin (ALB) were detected in the patients before treatment, 2 weeks after treatment, and at the end of the treatment. Any side-effect would be recorded., Results: In the patients with severe chronic hepatitis, the total effective rate of the treatment was 88.9%. The levels of ALT, AST and TBIL decreased significantly (P<0.001), whereas those of PTA and ALB increased significantly (P<0.001), and the level of AFP increased slightly. In patients with heavy type hepatitis, the total effective rate of this treatment was 78.4%, and patients at different stage showed different results. The total effective rates of patients with early, medium and terminal stage heavy type hepatitis were 89.9%, 84.8% and 27.5%, respectively. No severe side-effect was shown., Conclusion: PHGF is effective and safe in the treatment of patients with heavy type hepatitis and severe chronic hepatitis. But it should be administered early in patients with heavy type hepatitis so as to get better curative effects.

Objective: To establish a new and efficient method(IEDA) for detection of hemorrhagic fever with renal syndrome virus (HFRSV) antigen., Methods: An immune enzyme dot assay (IEDA) with mixture of three sorts anti-HFRSV-IgG, which was obtained from rabbit vaccinated with EHFV R22, Chen and Hubei strain was employed to detect HFRSV antigen in serum and urine from epidemic hemorrhagic fever (EHF) patients, and compared with indirect immune fluorescence assay (I-IFA), 76 serum samples and 40 urine samples were detected in this study., Results: The results showed that the total positive rate of HFRSV antigen detected by IEDA was 73.68% in serum and 65.00% in urine, while that detected by I-IFA was 75.00% and 70.00%, respectively. The positive rate in primary phase (within 5 days) of HFRSV antigen detected by IEDA was 94.34% in serum and 83.33% in urine, while that detected by I-IFA was 64.42% and 55.56%, respectively, there was significant difference in both serum and urine detections. Correlation study showed a high correlation in the result of IEDA and I-IFA., Conclusion: The results of this study suggested that the IEDA, as compared with I-IFA, was a more specific, sensitive, rapid and simple method with higher positive rate in primary phase. IEDA could be widely used for early diagnosis of HFRS in hospital at grassroots level.

Aim: To study the effects of pentoxifylline (PTX) on the content of hepatic TGF-beta1, type I and type III collagen in schistosomiasis japonica mice with liver fibrosis and its mechanism of anti-fibrosis., Methods: Forty mice with schistosomiasis were divided into four groups: one group as control without any treatment, other three were treated with Praziquantel 500 mg/(kg x d)for 2 d, high dose PTX 360 mg/(kg x d) for 8 wk, and low dose PTX 180 mg/(kg x d) for 8 wk respectively. Immunohistochemical technique and multimedia color pathographic analysis system were applied to observe the content change of hepatic TGF-beta1, type I and type III collagen in schistosomiasis japonica mice with liver fibrosis before and after PTX treatment., Results: Effects of PTX on the content change of hepatic TGF-beta1, type I and type III collagen in schistosomiasis japonica mice with liver fibrosis were related to the dosage of PTX, high dose PTX treated group could significantly reduce the content of TGF-beta1 (0.709+/-0.111), type I (0.644+/-0.108) and type III (0.654+/-0.152) collagen compared with those of control group (0.883+/-0.140, 0.771+/-0.156, 0.822+/-0.129) with statistical significance (P<0.05). Low dose PTX could also reduce the hepatic content of TGF-beta1 (0.752+/-0.152), type I (0.733+/-0.117) and type III (0.788+/-0.147) collagen, but without statistical significance (P>0.05). Both high dose and low dose PTX groups have significant differences on the content of TGF-beta1, type I and type III collagen (P<0.05, P<0.05, P<0.01, respectively)., Conclusion: High dose of PTX treatment could reduce the content of hepatic TGF-beta1, type I and type III collagen significantly in schistosomiasis japonica mice with liver fibrosis, and thus plays its role of antifibrosis.

Objective: To detect the expression of IL-2 and TNF-alpha in the liver at different period postinfection of Schistosoma japonicum and their effect on liver fibrosis after supplementary injection of these cytokines., Methods: Mice were infected with schistosome cercariae and divided into 3 groups. Two groups were injected (i.p.) every other day with IL-2 and TNF-alpha respectively for consecutive 4 wk. The third group and an uninfected group of normal mice were regarded as control. The ABC immunohistochemistry and pathologic image multimedia quantification system were applied to detect activity of IL-2 and TNF-alpha., Results: The level of IL-2 and TNF-alpha in the liver in infected but untreated group slowly decreased (from 8, 11, 14 to 18 wk). The supplementary injection of the cytokines at 6 wk postinfection in the two groups increased the cytokines significantly, the level of IL-2 or TNF-alpha was higher at 1-8 wk after the last injection than that of both infected and uninfected control groups (P < 0.01). The granulomatous inflammation and fibrosis in the livers of the two groups were slighter than that of the control., Conclusion: At the 6th wk postinfection with egg deposition, exogenous supplementation with TNF-alpha or IL-2 induces enhanced expression of the two kinds of cytokines, corresponding to a diminished degree of the liver granulomatous inflammation and fibrosis.

Objective: To study the effect of pentoxifylline (PTX) on the content of hepatic TGF-beta 1, type I and type III collagen in schistosome-infected mice with liver fibrosis., Methods: Forty mice with schistosomiasis were divided into four groups: one group as control without any treatment, other three were treated with praziquantel 500 mg/(kg.d) for 2 d, high dose PTX 360 mg/(kg.d) for 8 wk, and low dose PTX 180 mg/(kg.d) for 8 wk respectively. Immunohistochemical technique and multimedia color pathographic analysis system were applied to observe the content of hepatic TGF-beta 1, type I and type III collagen in mice infected with S. japonicum before and after treatment., Results: The effect of PTX on the content of hepatic TGF-beta 1, type I and type III collagen in mice was related to the dosage of PTX. High dose PTX treatment significantly reduced the content of TGF-beta 1, type I and type III collagen compared to the control (P < 0.01), whereas no difference was found between the group of low dose PTX treatment and control (P > 0.05)., Conclusion: High dose PTX treatment could reduce the content of hepatic TGF-beta 1, type I and type III collagen significantly in schistosome-infected mice with liver fibrosis.

AIM:To explore the relationship between endoinfection caused by intestinal flora translocation and multiple organ dysfunction in hepatic failure.METHODS:By using the quantitative bacteria culture, bacteria colony was counted in GI tract, bile duct and mesenteric lymphonodus in rat hepatic failure model.RESULTS:Intestinal flora migrated up to the upper GI tract and overgrew in stomach and jejunum in rats with hepatic failure.The number of bacteria colonies in the specimens of stomach, jejunum and ileum were 4.7X10(4)/mL, 2.1X10(5)/mL, 5.5X10(6)/mL in experiment group and 4.6X10(2)/mL, 6.1X10(1)/mL, 2.4X10(3)/mL in control group respectively (P < 0.05 ). Bacteria in bile duct and mesenteric lymphonodus of hepatic failure rats were also cultured. Extensive damages of gastrointestinal mucosa caused by bacterial overgrowth were observed.CONCLUSION:Intestinal flora translocation and overgrowth in stomach and jejunum formed an endoinfectious source and caused obvious pathological injury of gastrointestinal mucosa, which play a very important role in developing abdominal distension, toxic intestinal expansion, alimentary tract haemorrhage and endotoxemia in patients with hepatic failure.