Unidirectional single-mode lasing realization and temperature-induced mode switching in asymmetric GaN coupled cavities.

Effective lasing mode control and unidirectional coupling of semiconductor microlasers are vital to boost their applications in optical interconnects, on-chip communication, and bio-sensors. In this study, symmetric and asymmetric GaN floating microdisks and coupled cavities are designed based on the Vernier effect and then fabricated via electron beam lithography, dry-etching of GaN, and isotropic wet-etching of silicon (Si) support. The lasing properties, including model number, threshold, radiation direction, and mode switching method, are studied. Compared to its symmetrical structure, both experimental and simulated optical field distributions indicate that the lasing outgoing direction can be controlled with a vertebral angle on the disk. The whispering gallery mode (WGM) lasing of the structures, with a quasi-single-mode lasing at 374.36 nm, a dual-mode lasing at 372.36 nm, and 373.64 nm at coupled cavities, are obtained statically. More interestingly, a switching between dual-mode and single-mode can be achieved dynamically via a thermal-induced mode shifting.

[Analysis on the HIV-1 molecular transmission characteristics of newly confirmed HIV/AIDS in Jiaxing city, 2017-2018].

Objective: To analyze the relationship between infection and transmission of HIV/AIDS, explore the characteristics of the HIV-1 transmission network, and provide evidence for formulating targeted prevention and control measures. Methods: The newly confirmed HIV/AIDS in Jiaxing from 2017 to 2018 were selected for the study. The sociodemographic and infection transmission-related information was gathered. The blood samples were collected and RNA was extracted, RT-PCR and nested PCR amplified the pol gene of HIV-1. The phylogenetic tree was constructed by Mega 6.0 software for subtype analysis. The genetic distance between strains was calculated, and the molecular transmission network was drawn by using Cytoscape 3.6.0 software. The results of the epidemiological study based on the molecular transmission network were analyzed. Results: There were fifteen HIV-1 gene subtypes in 517 cases of HIV/AIDS. The main subtypes were CRF01_AE (37.1%)、CRF07_BC (36.2%) and CRF08_BC (11.8%). Under the 1.0% gene distance threshold, 87 molecular clusters were established, and the total clustering rate was 45.8% (237/517). The cluster risk factors were 60-81 age group (compared with 14-24 age group, OR=2.690, 95%CI:1.058-6.844), married (compared with unmarried, OR=1.698, 95%CI:1.003-2.875), CRF07_BC subtype (compared with CRF01_AE, OR=2.203, 95%CI:1.426-3.404). The largest molecular cluster, CRF07_BC-1, consisted of 50 cases (including 21 cases confirmed in 2017 cases and 29 confirmed in 2018). Multivariate analysis showed that characteristics of unmarried (compared with married, OR=2.482, 95%CI:1.140-5.402), gays (compared with heterosexual, OR=3.163, 95%CI:1.543-6.483), cases with high-risk transmission (compared with other cases, OR=7.631, 95%CI:1.783-32.654), confirmed in Nanhu and Pinghu districts of Jiaxing (compared with other districts, OR=2.225, 95%CI:1.074-4.608) were risks for entering the largest molecular cluster. There were seven suspected high-risk transmission MSM in the largest molecular cluster. The first debut of homosexual behavior was from 2010 to 2018, and the median number of gay partners was 20 (P25, P75：10, 100) within two years before being diagnosed. Six reported a recent history of looking for gay partners in an MSM dating place in Nanhu district. Conclusions: The HIV-1 subtypes of newly confirmed HIV/AIDS were diverse, mainly sporadic in Jiaxing from 2017 to 2018. There were geographical aggregation characteristics and suspected some high-risk transmission cases, suggesting that rapid transmission and targeted intensive intervention are needed.

Effective corrosion inhibition of mild steel by eco-friendly thiourea functionalized glucosamine derivatives in acidic solution.

In the view of environmental protection and sustainable development, the application of green effective inhibitors for metal corrosion in industry field is of great significance. In this work, two thiourea functionalized glucosamine derivatives, 5-hydroxy-1-phenyl-4-(1,2,3,4-tetrahydroxybutyl)imidazolidine-2-thione (GA-1) and 1-phenyl-3-(2,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-3-yl)thiourea (GA-2), were synthesized as eco-friendly corrosion inhibitors for mild steel (MS) in 1 M HCl solution, and their inhibition performance were evaluated by electrochemical tests and surface analyses. The electrochemical tests and surface analyses indicate that both GA-1 and GA-2 have high inhibition performance. Especially for GA-2, the inhibition efficiency reaches 97.7% with a concentration of 0.64 mM. Theoretical calculations were also conducted to elucidate the adsorption mechanism of GA-1 and GA-2 on MS surface.

[Analysis of the effect of percutaneous vertebroplasty combined with (125)I seed implantation in the treatment of spinal metastatic epidural spinal cord compression].

Objective: To investigate the clinical efficacy of percutaneous vertebroplasty (PVP) combined with iodine-125 ((125)I) seed brachytherapy in the treatment of spinal metastatic epidural spinal cord compression (MESCC) and toassess the changes inthe grade of epidural spinal cord compression (ESCC) by magnetic resonance imaging (MRI). Methods: A total of 37 MESCC patients treated with PVP combined with (125)I seed brachytherapy in the interventional and vascular surgery department of Zhongda Hospital affiliated to Southeast University from January 2014 to June 2019 were retrospectively analyzed, including 23 cases of bilateral lower limbs paralysis. Total diseased vertebrae are 39 segments. Visual analogue scale (VAS) and paralysis of lower extremities were evaluated regularly before and after treatment, and VAS values at different follow-up time points were compared. At the same time, MRI was used to evaluate the changes of ESCC grade in the spinal canal and calculate the local lesion efficiency after operation. The postoperative local lesion efficiency at different follow-up times was compared. Results: PVP combined with (125)I seed implantation in all diseased vertebral bodies was successful. The average injection volume of polymethylmethacrylate (PMMA) was (3.2±1.3) ml/segment, the average number of (125)I seed implanted was (25.0±8.6) seeds/segment and the average radiation dose was (15.0±5.1) mCi/segment. The VAS before operation was 8.5, and postoperative VAS were respectively 3.6±1.3, 3.8±1.5, 3.4±1.4, 5.5±1.0, 5.9±1.4 at 5 days, 1 month, 3 months, 6 months, and 1 year after operation. The differences between all follow-up time points and preoperative VAS values were statistically significant (all P<0.001). Compared with 5 days, 1 month and 3 months after operation, VAS increased significantly at 6 months and 1 year after operation, and the difference was statistically significant (all P<0.001); there was no significant difference between the VAS value at 6 months after operation and 1 year after operation (P=0.405). At a follow-up of 3 months, 22 of 23 patients with paralysis of bilateral lower limbs regained the functions of autonomous walking and voiding; the effective rates of MESCC local lesions evaluated by MRI at 1 month, 3 months, 6 months, and>1 year were 89.7%, 91.9%, 90.6%, and 94.7%, respectively, and there was no statistically significant differences among those follow-up time points (all P>0.05). Conclusions: PVP combined with (125)I seed brachytherapy in the treatment of MESCC has significant improvement in immediate pain relief and spinal cord function. After combined treatment, MRI showed that the tumors around the spinal cord regressed dramatically, which could considerably reduce the MESCC grade and remain stable for a long time.

[Efficacy of a novel fully covered radioactive stent for advanced esophageal and gastric cardia cancer: a retrospective controlled study].

Objective: To assess the feasibility, safety, and efficacy of a novel fully covered radioactive stent for the treatment of advanced esophageal and gastric cardia cancer. Methods: Data of 122 patients, who underwent esophageal radioactive stent placement for advanced esophageal or gastric cardia cancer between January 2012 and September 2017 in Zhongda Hospital, were retrospectively analyzed. Patients were divided into the novel stent group (n=59; 45 males, 14 females; mean age 73±10 years old) and the conventional stent group (n=63; 51 males, 12 females; mean age 72±9 years old), according to the types of radioactive stents. No significant difference was found between the two groups in baseline characteristics (all P>0.05). Outcomes were measured in terms of technical success, dysphagia score, stent restenosis, stent migration, major complications, and overall survival. Results: The technical success rate was 98.3% in the novel stent group, and 100.0% in the conventional stent group (P=0.484) . The dysphagia scores 3 days after surgery decreased from 3.27±0.45 and 3.37±0.49 to 1.25±0.66 and 1.32±0.50, respectively (all P<0.01), and the variances were comparable (P=0.709). Compared with conventional stents, novel stents were significantly associated with a decreased in the rate of stent restenosis, 11.9% vs 27.0%; cause-specific hazard ratio 0.387, 95%CI 0.160-0.934 (P=0.035); sub-distributional hazard ratio 0.401, 95%CI 0.167-0.963 (P=0.041), while the stent migration rate was statistically comparable (13.6% vs 6.3%, P=0.181). There was no significant difference between the novel stent group and the conventional stent group in major complications (all P>0.05), including moderate-severe chest pain (22.0% vs 25.4%), hemorrhage (11.9% vs 11.1%), fistula formation (1.7% vs 4.8%), and aspiration pneumonia (5.1% vs 6.3%). The median overall survival was 146(95%CI 115-177) days in the novel stent group, and 147(95%CI 98-196) days in the conventional stent group, and no significant difference was found (P=0.967). Conclusions: In patients with advanced esophageal or gastric cardia cancer,placement of a novel fully covered radioactive stent is safe and effective. This novel stent can relieve dysphagia rapidly and prevent stent restenosis effectively.

Effects of human umbilical cord mesenchymal stem cells-derived exosomes on fracture healing in rats through the Wnt signaling pathway.

OBJECTIVE: To investigate the role of human umbilical cord mesenchymal stem cell (hucMSC)-derived exosomes in the Wnt signaling pathway and their effects on fracture healing in rats. MATERIALS AND METHODS: A total of 24 healthy male Sprague-Dawley (SD) rats were randomly divided into 3 groups, of which the experimental groups were injected with Phosphate-Buffered Saline (PBS) and hUCMSC-derived exosomes, respectively, at the fracture site, and a blank control group was set. At 2 and 3 w after treatment, respectively, the healing condition at the fracture site in the rats was detected by micro-computed tomography (CT). The protein expressions of ß-catenin and Wnt3a of the Wnt signaling pathway in the bone tissue were measured via Western blotting (WB) assay. Quantitative Real Time-fluorescence Polymerase Chain Reaction (qRT-PCR) was performed to determine the expressions of osteogenic marker genes [collagen type I (COL-1), osteopontin (OPN) and runt-related transcription factor 2 (RUNX2)]. RESULTS: The results of the micro-CT scan showed that the rats treated with exosomes had better apposition of the fracture site, and the appearance of cortical bone was continuous. The fracture sites in the blank control group and PBS injection group were not healed, and the appearance of cortical bone was discontinuous, with significant fracture lines. According to the WB results, the protein expression levels of ß-catenin and Wnt3a in exosome treatment group were significantly higher than those in the blank control group and PBS injection group (p<0.01). The qRT-PCR results indicated that the expression levels of COL-1, OPN and RUNX2 in exosome treatment group were increased evidently compared with those in the other two groups (p<0.01). CONCLUSIONS: HucMSC-derived exosomes are probably involved in the repair of fracture in rats through the Wnt signaling pathway.

Expression and prognosis of MYOZ2 in gastric cancer.

OBJECTIVE: To investigate the expression of human myozenin 2 (MYOZ2) in cancer tissues and its effect on the prognosis of patients with gastric cancer. PATIENTS AND METHODS: Gastric cancer tissue and adjacent normal tissue specimens were obtained from a total of 258 patients together with complete clinicopathological data. Those patients were treated in Harbin Medical University Cancer Hospital from March 2007 to March 2012. Quantitative Real Time-Polymerase Chain Reaction (RT-PCR) was used to detect the expression of MYOZ2 messenger RNA (mRNA) in gastric cancer tissues and normal gastric tissues, and correlations between the expression level of MYOZ2 in gastric cancer tissues and the clinicopathological parameters of patients were analyzed. MYOZ2 protein expression levels in different gastric cancer cells were detected by Western blotting; transwell chamber assay was used to detect the effect of MYOZ2 expression on the in-vitro migration and invasion abilities of gastric cancer cells; 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was applied to examine the in-vitro proliferation and growth abilities of gastric cancer cells. RESULTS: The expression level of MYOZ2 mRNA in gastric cancer tissues was significantly higher than that in cancer-adjacent tissues in 258 cases (p<0.05). Western blotting results showed that the expression level of MYOZ2 protein in gastric cancer tissues was significantly increased compared with that in the corresponding adjacent healthy tissues (p<0.05). In-vitro growth, migration and invasion abilities of MYOZ2 positive gastric cancer cells were significantly higher than those of normal tissue cells. Univariate analysis showed that the high expression level of MYOZ2 in gastric cancer tissues was closely related to tumor size, lymph node metastasis, and pathological tumor-node-metastasis (pTNM) staging (p<0.05), but not associated with gender, age, differentiation degree, and tumor location (p>0.05). The 1-, 3- and 5-year survival rates of patients with low expression level of MYOZ2 (n=130) were higher than those of patients with high expression level of MYOZ2 (n=128). Multivariate analysis revealed that the expression level of MYOZ2 (p=0.000), lymph node metastasis (p=0.002), and pTNM staging (p=0.015) were independent risk factors influencing the prognosis of gastric cancer. CONCLUSIONS: Our results showed that the expression level of MYOZ2 may play an important role in the occurrence and development of gastric cancer, and can also provide references for the clinical diagnosis and treatment of gastric cancer.

[Cement augmentation for vertebral osteolytic metastatic lesions: an evaluation on postoperative CT].

Objective: To evaluate the effectiveness of cement augmentation on the osteolytic lesion in patients with vertebral metastasis. Methods: A total of consecutive 132 patients with 268 vertebral metastatic lesions treated with PVP from January 2008 to December 2016 in Zhongda Hospital were enrolled in this study. Retrospective analysis of preoperative, postoperative 3 days, 3 months, 6 months, 12 months and ≥ 18 months imaging data on CT, the local control and progression of the tumor were evaluated by MDA response criteria. The local control rates were compared between the groups with the different rate of cement filling by Chi2-test. Results: Vertebroplasty procedures were performed successfully in all 268 vertebrae under DSA guidance, and the mean volume of PMMA injected in each vertebra was 0.7-8.5(3.9±1.5)ml.The rate of local control at 3 months, 6 months, 12 months and ≥18 months after PVP was respectively 98.9%, 95.1%, 91.8%, and 85.2%, the difference was statistically significant(all P<0.05). The local control rate showed a statistically significant relationship to the groups with the rate of cement filling at 6 months, 12 months and ≥18 months after PVP, but there was no statistical difference at postoperative 3 months. The rate of local control was higher in 68 patients with lung or gastrointestinal cancer than in 17 patients with liver or kidney cancer at 3 months, 6 months and 12 months, the difference was statistically significant (P<0.05). Conclusion: Cement augmentation has a local anti-tumor effect on vertebral osteolytic metastatic lesion, and the anti-tumor effect will decrease as the follow-up time extended.

MiR-363-3p modulates cell growth and invasion in glioma by directly targeting pyruvate dehydrogenase B.

OBJECTIVE: This study is designed to investigate the role of miR-363-3p in the cancer development of glioma. PATIENTS AND METHODS: The expression of miR-363-3p in glioma and adjacent noncancerous tissue was measured using quantitative RT-PCR. The expression of a target gene of miR-363-3p, pyruvate dehydrogenase B (PDHB), was determined by Western blot. The level of miR-363-3p was increased or decreased by transfected with miR-363-3p mimic or miR-363-3p inhibitor, respectively. The impact of miR-363-3p on cell growth, apoptosis and invasion was determined by CCK-8 (Cell Counting Kit) assay, flow cytometry, and transwell assay. The role of PDHB in mediating the oncogenic activities was demonstrated by co-transfected PDHB vector and miR-363-3p mimic. RESULTS: Our results have shown that miR-3663-3p level was significantly higher in glioma tissue. Furthermore, miR-363-3p functions as onco-miRNA, promotes cell proliferation, protects against apoptosis, and enhances invasion by directly targeting PDHB. CONCLUSIONS: MiR-363-3p is an onco-miRNA, which can be considered as a potential therapeutic target in glioma.

Increased expression of long noncoding RNA AK021443 predicts worse clinical outcome in hepatocellular carcinoma.

OBJECTIVE: Dysregulation of long non-coding RNAs (lncRNAs) plays critical roles in the process of carcinogenesis and tumor progression. LncRNA AK021443 (AK021443) has been reported to serve as a tumor promoter in hepatocellular carcinoma (HCC). The purpose of this study was to investigate the expression of AK021443 and its prognostic value in HCC.. PATIENTS AND METHODS: Quantitative Real-Time-PCR was used to examine the expression of AK021443 in 193 HCC tissues and adjacent non-tumor tissues. The correction between AK021443 expression and clinicopathological characteristics was evaluated with Chi-square test. To determine its prognostic value, overall survival was evaluated using the Kaplan-Meier method. Univariate and multivariate analyses were performed to analyze the prognostic significance of AK02144 expression. RESULTS: The results revealed that AK021443 expression levels were significantly higher in HCC tissues than in the corresponding noncancerous tissues (p<0.01). Besides, high AK021443 expression was correlated with poor tumor differentiation (p = 0.002), advanced clinical stage (p=0.001) and positive lymph node metastasis (p=0.005). In addition, the Kaplan-Meier survival curves revealed that HCC patients with high AK021443 expression level had shorter overall survival than those with low AK021443 expression level (p=0.0005). Finally, the multivariable analysis suggested that increased AK021443 expression was an independent prognostic factor of overall survival in HCC patients. CONCLUSIONS: Our findings indicated that AK021443 may play an important role in tumorigenesis and progression and would be a powerful marker to predict the prognosis of HCC patients.

[Implantation of the irradiation stent system intoportal vein: studies on normal beagles].

Objective: To assess the feasibility and safety of the irradiation stent system in portal vein on normal beagles. Methods: A portal vein irradiation stent system was composed of an Iodine-125 seeds-carrier and a conventional stent.Twenty beagle dogs were randomly assigned to receive treatment with a conventional stent (5 beagle dogs) or an irradiation stent system (15 beagle dogs in three groups received 11.1, 22.2, 33.3 MBq radioactivity, n=5 in each dose group). Follow-up methods included blood biochemical test, color Doppler sonographyand CT scan at 0, 15, 30, 60, and 120 days after implantation of irradiation stent system.Pathological tissues were obtained from sacrificed beagle dogs on the 120th day. Results: The portal vein irradiation stent systems and the conventional stents were successfully deployed into the targeted portal vein segment in all beagles, none was dislodged during the deployment or the follow-up period.Differences of blood biochemical indexes and portal vein flow volume measured by color Doppler sonography were not significant (P>0.05). Stent systems were morphologically intact and patent.None of the peripheral organs had hemorrhage, necrosis or perforation.Pathological tissues revealed that the systems were surrounded by fibrous tissues and a few inflammatory cells, but with no significant differences in all groups. Conclusion: It indicates that portal veinirradiation stent system is safe in all dose groups, and it is feasible to design a special irradiation stent system for each patient according to the size of the portal vein tumor thrombus.

Bioinformatics-based design of novel antigenic B-cell linear epitopes of Deinagkistrodon acutus venom.

OBJECTIVE: With the help of bioinformatics analysis, we wished to develop a novel antivenom against the Deinagkistrodon (D.) acutus snake venom using B-cell linear epitopes of three primary toxins (serine protease, metalloprotease, and phospholipase A2). MATERIALS AND METHODS: cDNA sequences of three toxins of D. acutus venom were retrieved from the NCBI database. B-cell linear epitopes were predicted using DNAStar and the website server software provided by IEDB. Then, the sequences of the predicted epitopes were artificially synthesized and inserted into the vector pET-32a-c(+). Recombinant antigen peptide was expressed and purified. BALB/c mice were immunized with the recombinant antigen peptide. The immunoprotective effect of this novel antivenom was measured by neutralization of venom haemorrhagic activity. RESULTS: Six epitopes were obtained by bioinformatics analysis. ELISA analysis showed that antibody titre was >8,000 against snake venom and >64,000 against the recombinant peptide. Neutralization assays confirmed that the developed antivenom could effectively reduce the haemorrhagic activity of snake venom. CONCLUSIONS: Six B-cell linear epitopes of D. acutus snake venom were predicted by bioinformatics analysis and successfully utilized to produce a novel antivenom.

Research on Auditory Long Latency Response in Normal Hearing Subjects.

OBJECTIVES: To explore the characters and the relationship among latency response, amplitude and sound stimulus intensity of auditory long latency response（ALR）, and to investigate the significance of ALR applied in auditory threshold prediction. METHODS: Total 46 subjects （92 ears） with normal hearing were tested by ALR. The ALR waves of the subjects were elicited by 5 sound stimulus intensity according to the order of 70, 50, 30, 20 and 10 dB nHL. By making N1 wave and P2 wave, the values of 3 observed indexes （the latencies of N1 wave and P2 wave and N1-P2 amplitude） were obtained, and the variation trend of the observed indexes were statistically analyzed. The differences in the frequency of the indexes were observed. RESULTS: The rate of ALR waves from 46 subjects （92 ears） with normal hearing was 100%. The latencies of N1 wave and P2 wave delayed gradually and N1-P2 amplitude declined with sound stimulus intensity descending. CONCLUSIONS: In suitable conditions, ALR is a stable technology for hearing thresholds prediction. The relation between sound stimulus intensity and latency of N1 wave, latency of P2 wave and N1-P2 amplitude of ALR plays an important part in auditory thresholds assessment.

Neuroprotective effects of Bcl-2 overexpression on nerve cells of rats with acute cerebral infarction.

We aimed to investigate the influence of lentiviral-mediated Bcl-2 overexpression in cerebral tissues of rats with acute cerebral infarction. Forty-five rats were randomly divided into sham, model, and treatment groups. The sham and model groups were administered a control lentiviral vector via the intracranial arteries 10 days before surgery, while the treatment group received lentivirus encoding a Bcl-2 overexpression vector. We induced cerebral artery infarction using a suture-occlusion method and analyzed the cerebral expression levels of apoptosis-related genes (caspase-3, Bax), total cerebral apoptosis, range of cerebral tissue infarction, and changes in nerve cell function after 72 h. The Bcl-2-encoding lentivirus was well expressed in rat cerebral tissues. The treatment group had significantly higher expression levels of Bcl-2 than the other two groups. After cerebral infarction, the model group had significantly increased expression levels of caspase-3 and Bax protein in cerebral tissues than the sham (P < 0.05). Expression of these apoptosis-related proteins in the treatment group was obviously lower than that in the model group (P < 0.05), but significantly higher than in the sham group (P < 0.05). Compared to sham, neuronal apoptosis levels and infarction range of cerebral tissues was increased in the model and treatment groups; however, these values in the treatment group were significantly lower than that in the model group (P < 0.05). Importantly, the treatment group had significantly decreased neurological impairment scores (P < 0.05). In conclusion, Bcl-2 over-expression can decrease neuronal apoptosis in rat cerebral tissue, and thus is neuroprotective after cerebral ischemia.

FoxM1 regulates Sirt1 expression in glioma cells.

BACKGROUND AND OBJECTIVES: Glioma accounts for most of primary malignant brain tumors and usually results in poor survival. However, the key signaling networks regulating glioma cell proliferation remain poorly defined. The forkhead box M1 (FoxM1) is a key transcription factor regulating multiple aspects of cell biology. Prior studies have shown that FoxM1 is overexpressed in glioma and plays a critical role in cancer development and progression. MATERIALS AND METHODS: Western blot and Real-time PCR assays were used to determine the regulation roles of FoxM1 on Sirt1 (Sirtuin1) expression. Small interfering RNAs (siRNAs) were used to silence the expression of FoxM1. Luciferase assays were used to measure binding of FoxM1 to the promoter region of Sirt1. Direct binding of FoxM1 to promoter of Sirt1 was assessed by chromatin immunoprecipitation (CHIP) assays. RESULTS: We found that FoxM1 positively regulated mRNA expression of Sirt1. FoxM1 overexpression promoted while its knockdown inhibited Sirt1 expression. Besides, we identified a minimal FoxM1 binding site on the promoter region of Sirt1. CONCLUSIONS: Our results for the first time add a new FoxM1-Sirt1 connection that mediates cell proliferation in glioma.

Fabrication and characterization of n-ZnO nanonails array/p(+)-GaN heterojunction diode.

A novel heterojunctional structure of n-ZnO nanonails array/p(+)-GaN light-emitting diode was fabricated by Chemical Vapor Deposition method. A broad electroluminescence spectrum shows two peaks centered at 435 nm and 478 nm at room temperature, respectively. By comparing the photoluminescence and electroluminescence spectra, together with analyzing the energy band structure of heterojunction light emitting diode, it suggested that the electroluminescence peak located at 435 nm originates from Mg acceptor level of p(+)-GaN layer, whereas the electroluminescence peak located at 478 nm originates from the defects of n-ZnO nanonails array.

Inhibition of cytochrome P450 3A4 activity by schisandrol A and gomisin A isolated from Fructus Schisandrae chinensis.

We studied the effects of schisandrol A (SCH) and gomisin A (GOM), two of the main bioactive components of Fructus Schisandrae chinensis, on cytochrome P450-3A4 (CYP3A4) activity and cellular glutathione (GSH) level. In a cell-free system both SCH and GOM inhibited CYP3A4 activity with IC(50) values of 32.02 microM and 1.39 microM, respectively. SCH or GOM at concentrations up to 100 microM did not alter cellular GSH level in regular HepG2 cells and P-glycoprotein overexpressing HepG2-DR cells. Since SCH and GOM may reverse multidrug resistance (MDR) by impeding the activity of P-glycoprotein, a membrane xenobiotic exporter, SCH or GOM could affect cellular drug metabolism in addition to drug uptake.