Application value of a deep learning method based on a 3D V-Net convolutional neural network in the recognition and segmentation of the auditory ossicles.

Objective: To explore the feasibility of a deep learning three-dimensional (3D) V-Net convolutional neural network to construct high-resolution computed tomography (HRCT)-based auditory ossicle structure recognition and segmentation models. Methods: The temporal bone HRCT images of 158 patients were collected retrospectively, and the malleus, incus, and stapes were manually segmented. The 3D V-Net and U-Net convolutional neural networks were selected as the deep learning methods for segmenting the auditory ossicles. The temporal bone images were randomized into a training set (126 cases), a test set (16 cases), and a validation set (16 cases). Taking the results of manual segmentation as a control, the segmentation results of each model were compared. Results: The Dice similarity coefficients (DSCs) of the malleus, incus, and stapes, which were automatically segmented with a 3D V-Net convolutional neural network and manually segmented from the HRCT images, were 0.920 ± 0.014, 0.925 ± 0.014, and 0.835 ± 0.035, respectively. The average surface distance (ASD) was 0.257 ± 0.054, 0.236 ± 0.047, and 0.258 ± 0.077, respectively. The Hausdorff distance (HD) 95 was 1.016 ± 0.080, 1.000 ± 0.000, and 1.027 ± 0.102, respectively. The DSCs of the malleus, incus, and stapes, which were automatically segmented using the 3D U-Net convolutional neural network and manually segmented from the HRCT images, were 0.876 ± 0.025, 0.889 ± 0.023, and 0.758 ± 0.044, respectively. The ASD was 0.439 ± 0.208, 0.361 ± 0.077, and 0.433 ± 0.108, respectively. The HD 95 was 1.361 ± 0.872, 1.174 ± 0.350, and 1.455 ± 0.618, respectively. As these results demonstrated, there was a statistically significant difference between the two groups (P < 0.001). Conclusion: The 3D V-Net convolutional neural network yielded automatic recognition and segmentation of the auditory ossicles and produced similar accuracy to manual segmentation results.

The Influence of Long-Term Dietary Intake of Titanium Dioxide Particles on Elemental Homeostasis and Tissue Structure of Mouse Organs.

Background: Titanium dioxide (TiO2), consisting of nanoparticles and sub-microparticles, were widely used as food additive and consumed by people every day, which has aroused a public safety concern. Some studies showed TiO2 can be absorbed by intestine and then distributed to different tissues after oral intake, which is supposed to affect the content of various elements in the body whereas led to tissue damage. However, knowledge gaps still exist in the impact of TiO2 on the disorder of elemental homeostasis. Thus, this study aimed to explore the oral toxicity of TiO2 by assessing its influence on elemental homeostasis and tissues injury. Method: ICR mice were fed with normal feed, TiO2 nanoparticles (NPs)-mixed feed or TiO2 submicron particles (MPs)-mixed feed (1% mass fraction TiO2 NPs or MPs were mixed in commercial pellet diet) for 1, 3, and 6 months. Particles used in this study were characterized. The distribution of Ti and other 23 elements, the correlation among elements, and pathological change in the liver, kidney, spleen and blood cells of the mice was determined. Result: Ti accumulation only appeared in blood cells of mice treated with TiO2 MPs-mixed feed for 6 months, but TiO2 cause 12 kinds of elements (boron, vanadium, iron, cobalt, copper, zinc, selenium, sodium, calcium, magnesium, silicon, phosphorus) content changed in organ tissue. The changed kinds of elements in blood cells (6 elements), liver (7 elements) or kidney (6 elements) were more than in the spleen (1 element). The TiO2 NPs induced more elements changed in blood cells and liver, and the TiO2 MPs induced more elements changed in kidney. Significantly positive correlation between Ti and other elements was found in different organs except the liver. Organ injuries caused by TiO2 NPs were severer than TiO2 MPs. Liver exhibited obvious pathological damage which became more serious with the increase of exposure time, while kidney and spleen had slight damages. Conclusion: These results indicated long-time dietary intake of TiO2 particles could induce element imbalance and organ injury. The liver displayed more serious change than other organs, especially under the treatment with TiO2 NPs. Further research on the oral toxicity of TiO2 NPs should pay more attention to the health effects of element imbalances using realistic exposure methods.

Predictive Factors of Hemorrhage After Thrombolysis in Patients With Acute Ischemic Stroke.

Background: Ischemic stroke has a poor prognosis and brings a ponderous burden on families and society. Hemorrhagic transformation (HT) after intravenous thrombolysis can increase the mortality of patients with ischemic stroke. Thus, finding new HT biomarkers to be applicable in clinical practice is of great importance. Methods: The related risk factors were recruited for analysis, including smoking, drinking, hyperlipidemia, diabetes, anamnesis, and pathological indicators. Moreover, the relationship between serum levels of caveolin-1, caveolin-2, and HT after rt-PA treatment were also studied. Results: We studied 306 patients with acute ischemic stroke treated with recombinant tissue type plasminogen activator (rt-PA) within 4.5 h of symptom onset. The results showed that Age ≥68 years, smoking, Atrial fibrillation, NIHSS score before thrombolysis ≥17, and systolic pressure 2 h after thrombolysis (mmHg) ≥149 increased the risks of HT after rt-PA administration. Remarkably, the concentration of caveolin-1 (ng/mL) ≤ 0.12 and caveolin-2 (ng/mL) ≤ 0.43 in serum increased the risks of HT after rt-PA administration. Conclusion: Knowledge on the risk factors associated with HT after rt-PA treatment may help develop treatment strategies and reduce the risk of HT. Caveolin-1 and caveolin-2 can be predictors of HT after rt-PA administration. These findings provide evidence for future further investigations aimed to validate these biomarkers.

Comparative study of intravenous thrombolysis with rt-PA and urokinase for patients with acute cerebral infarction.

OBJECTIVE: Cerebral infarction has a poor prognosis and causes a serious burden on families and society. Recombinant tissue plasminogen activator (rt-PA) and urokinase (UK) are commonly used thrombolytic agents in the clinic. However, direct and powerful clinical trial evidence to determine the therapeutic effect of rt-PA and UK on intravenous thrombolysis is lacking. METHODS: In this study, 180 patients with acute cerebral infarction were treated with rt-PA or UK. The National Institutes of Health Stroke Scale (NIHSS) scores, Barthel index, bleeding complications, and biomarkers were evaluated. RESULTS: No significant differences in NIHSS or Barthel scores were found between the groups. However, UK increased the risk of intracranial haemorrhage compared with rt-PA. rt-PA had increased activity in reducing serum levels of MMP-9 than UK. CONCLUSION: Intravenous thrombolysis with rt-PA and UK in the time window of acute cerebral infarction can achieve similar therapeutic effects, but rt-PA can further reduce the risk of cerebral haemorrhage and is relatively safer than UK.

Comprehensive analysis of microRNA-messenger RNA regulatory network in gemcitabine-resistant bladder cancer cells.

Chemotherapy is still a standard treatment of unresectable bladder cancer or distant metastases. The chemotherapy resistance always occurs after a period of treatment indicating poor prognosis. The current study aimed to explore the molecular mechanism of chemoresistance in bladder cancer cells. The gene expression profiles of GSE77883, including three untreated T24 cells samples and three gemcitabine-resistant T24 cells samples, was downloaded from Gene Expression Omnibus database. The screening of differentially expressed genes (DEGs), gene function analysis, and interaction prediction between microRNAs (miRNAs) and DEGs were performed by R software. The protein-protein interaction (PPI) and miRNA-DEGs networks were constructed and visualized by Cytoscape software. Then, the small molecules, with potential synergistic or antagonistic effects to gemcitabine resistance, were identified using the Connectivity Map database. Finally, gemcitabine-resistant T24 cell line was established and key genes were validated by quantitative real-time polymerase chain reaction (qRT-PCR). In total, 536 upregulated and 513 downregulated genes were screened and mainly enriched in oxidative stress response and signaling pathways related to extracellular matrix-receptor interaction and focal adhesion. PPI network showed interleukin 6, tumor necrosis factor, kinesin family member 11, and BUB1 mitotic checkpoint serine/threonine kinase B were key genes. The miRNA-DEGs regulatory networks included 18 miRNAs and 185 DEGs, including miR-182-5p, miR-590-3p, miR-320a and serum- and glucocorticoid-regulated kinase 1 (SGK1). Then, the related key genes and miRNAs were confirmed by qRT-PCR. Furthermore, 81 small molecules with antagonistic or synergistic effect to GEM were screened. We have investigated the molecular mechanisms driving GEM-resistance in bladder cancer cells that would contribute to the development of chemotherapy for advanced bladder cancer.

Combined standard percutaneous nephrolithotomy and 4.8Fr micro- percutaneous nephrolithotomy and for multiple renal calculi (46 cases) / 中国内镜杂志

Objective To explore the application of visible standard channel combined with F4.8 visible puncture percutaneous nephrolithotomy in the treatment of multiple renal calculi. Methods The clinical data of 46 patients with multiple renal calculi from October 2015 to September 2016 were retrospectively analyzed. There were 28 male and 18 female, with a mean age of 42.6 years (aged from 25 to 65 years). Stone diameter 3.0~5.2 cm, average (4.3 ± 0.8) cm. Application of F4.8 visual puncture assisted angioplasty to establish the standard channel, nephrolithotomy combined with ultrasonic lithotripsy treatment in the field of visible stones, then apply the F4.8 visual micro puncture percutaneous nephrolithotomy combined with holmium laser treatment of other parts of the stone, summarizes the channel establishment total time, operation time, blood red protein decreased and stone clearance rate and complication index. Results All cases were successfully established single standard channel under the guidance of F4.8 visual puncture, 24 cases were combined with single ultramicro channel, 16 cases were combined with double ultramicro channels, and the other 6 cases were combined with the three ultra micro channels. Postoperative indwelling single renal fistula, micro channel indwelling fistula, postoperative indwelling F5 double J tube. F4.8 visual puncture established standard channel establishment time (6.8 ± 1.8) min, single F4.8 visible puncture ultra - channel establishment time of (4.5 ± 0.9) min, operation time of (92.0 ± 15.0) min. A stone clearance rate was 91.3% (42/46), a decrease in hemoglobin value of (12.2 ± 2.5) g/L, 8 cases of postoperative fever, given anti-inflammatory treatment improved, 4 cases with residual calyceal stones visible 0.5~0.8 cm, given extracorporeal shock wave lithotripsy combined with postural drainage, stone, 1 months after the treatment of stones were discharged, did not appear Shi Jie, delayed bleeding, adjacent organ injury, ureteral injury cases. Conclusion Visual standard channel combined with F4.8 ultra visible puncture percutaneous nephrolithotomy in treatment of multiple renal calculi has the advantages of reducing the large number of channels, high stone clearance rate, safety, less complications, F4.8 was used to establish the visual puncture channel is more safe and accurate.

Combined standard percutaneous nephrolithotomy and 4.8Fr micro- percutaneous nephrolithotomy and for multiple renal calculi (46 cases) / 中国内镜杂志

Objective To explore the application of visible standard channel combined with F4.8 visible puncture percutaneous nephrolithotomy in the treatment of multiple renal calculi. Methods The clinical data of 46 patients with multiple renal calculi from October 2015 to September 2016 were retrospectively analyzed. There were 28 male and 18 female, with a mean age of 42.6 years (aged from 25 to 65 years). Stone diameter 3.0~5.2 cm, average (4.3 ± 0.8) cm. Application of F4.8 visual puncture assisted angioplasty to establish the standard channel, nephrolithotomy combined with ultrasonic lithotripsy treatment in the field of visible stones, then apply the F4.8 visual micro puncture percutaneous nephrolithotomy combined with holmium laser treatment of other parts of the stone, summarizes the channel establishment total time, operation time, blood red protein decreased and stone clearance rate and complication index. Results All cases were successfully established single standard channel under the guidance of F4.8 visual puncture, 24 cases were combined with single ultramicro channel, 16 cases were combined with double ultramicro channels, and the other 6 cases were combined with the three ultra micro channels. Postoperative indwelling single renal fistula, micro channel indwelling fistula, postoperative indwelling F5 double J tube. F4.8 visual puncture established standard channel establishment time (6.8 ± 1.8) min, single F4.8 visible puncture ultra - channel establishment time of (4.5 ± 0.9) min, operation time of (92.0 ± 15.0) min. A stone clearance rate was 91.3% (42/46), a decrease in hemoglobin value of (12.2 ± 2.5) g/L, 8 cases of postoperative fever, given anti-inflammatory treatment improved, 4 cases with residual calyceal stones visible 0.5~0.8 cm, given extracorporeal shock wave lithotripsy combined with postural drainage, stone, 1 months after the treatment of stones were discharged, did not appear Shi Jie, delayed bleeding, adjacent organ injury, ureteral injury cases. Conclusion Visual standard channel combined with F4.8 ultra visible puncture percutaneous nephrolithotomy in treatment of multiple renal calculi has the advantages of reducing the large number of channels, high stone clearance rate, safety, less complications, F4.8 was used to establish the visual puncture channel is more safe and accurate.

Quantitative measurement to evaluate morphological changes of the corpus callosum in patients with subcortical ischemic vascular dementia.

BACKGROUND: Subcortical ischemic vascular dementia (SIVD) is a subtype of dementia associated with abnormalities in the subcortical white matter regions. Recent imaging techniques can be used to detect such abnormalities in vivo. PURPOSE: To examine morphological changes of the corpus callosum in patients with SIVD by using magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI). MATERIAL AND METHODS: MRI was performed to explore changes of cerebral white matter, especially corpus callosum. Brain matter diffusivity was examined with DTI by measuring the fractional anisotropy (FA). Results of 30 patients diagnosed with SIVD and 30 healthy subjects were analyzed and compared. RESULTS: The thicknesses of the genu, the anterior third, middle, and posterior third of the body, and the splenium of the corpus callosum were smaller in SIVD patients compared to healthy controls (0.54 ± 0.08 vs. 0.68 ± 0.09 cm, P = 0.0011; 0.27 ± 0.06 vs. 0.38 ± 0.07 cm, P = 0.002; 0.28 ± 0.05 vs. 0.38 ± 0.08 cm, P = 0.009; 0.18 ± 0.04 vs. 0.26 ± 0.06 cm, P = 0.013; 0.54 ± 0.07 vs. 0.72 ± 0.09 cm, P = 0.003, respectively). The FA values of the genu and splenium of the corpus callosum in patients with SIVD were decreased compared to healthy controls (0.664 ± 0.042 vs. 0.778 ± 0.041, P < 0.001; 0.691 ± 0.038 vs. 0.786 ± 0.039, P = 0.001, respectively). CONCLUSION: Patients with SIVD exhibit corpus callosum atrophy and morphological changes, and these characteristics may be useful for diagnosis.

Effect of GINS2 on proliferation and apoptosis in leukemic cell line.

Although previous researches have demonstrated that GINS2 express abundantly and abnormally in many malignant solid tumors, such as breast cancer, melanoma and hepatic carcinoma. However, the role and precise molecular mechanism in acute promyelocytic leukemia (APL) are rarely reported. In this current study, we investigated the possible effect and particular mechanism of GINS2 in occurrence and development of APL. We synthesized interference plasmid targeted GINS2 successfully in vitro and also constructed recombinant adenovirus vector carrying GINS2 gene in order to down-regulate or up-regulate GINS2 expression from two aspects of positive and negative in APL. After siRNA were transfected into HL60 cells, both GINS2 expression level of mRNA and protein in interfering group were down-regulated when compared with control groups. Together, MTT and flow cytometry technology showed that cell growth was significantly inhibited. Moreover, the expression lever of Bax was distinctly increased whereas Bcl2 was dramatically decreased in transfected group. Further experiments revealed that down-regulation of GINS2 expression inhibited DNA replication and had a G2/M phase block in HL60 cells. What's more, ATM, CHK2, and P53 gene could involve in the pathogenic signaling pathways of HL60 cells when GINS2 gene was down-regulated. On the contrary, after HL60 cells were infected by recombinant adenovirus vector which contained GINS2 gene, we observed that over-expression of GINS2 could promote HL-60 cell proliferation. What's more, GINS2 might implicate a potential target for leukemia gene therapy.

[Construction of pBIFC-VN173-CXCR4 and pBIFC-VC155-NT21MP eukaryotic expression plasmids and their interaction in living cells].

OBJECTIVE: To construct pBIFC-VN173-CXCR4 and pBIFC-VC155-NT21MP eukaryotic expression plasmids and to investigate the interaction of chemokine receptor 4 (CXCR4) and viral macrophage inflammatory protein-II(vMIP-II) N terminal 21 peptides (NT21MP) in living cells. METHODS: DNA fragment encoding NT21MP was chemically synthesized and inserted into BiFC eukaryotic expression vector pBIFC-VC155. The full length of CXCR4 DNA fragment was amplified by RT-PCR from SKBR (3) cells and inserted into BiFC eukaryotic expression plasmid pBIFC-VN173. Two recombinant vectors were identified by restriction enzyme digestion and DNA sequencing. The recombinant vectors were cotransfected into Africa green monkey kidney fibroblast COS-7 cells by using Lipofectamine 2000. The interaction of NT21MP and CXCR4 was detected by bimolecular fluorescence complementation (BiFC) assay. RESULTS: The restriction enzyme digestion and DNA sequences and open read frames of two vectors were consistent with experiment design. The BiFC plasmids were successfully cotransfected into the target cells and expressed. The strong BiFC signals were detected in pBIFC-VN173-CXCR4 and pBIFC-VC155-NT21MP cotransfected cells and the fluorescence signal was located in the cytoplasm. CONCLUSION: The eukaryotic expression plasmids for BiFC assay are successfully constructed. The interaction of NT21MP and CXCR4 in living cells can be detected by using this technology.

[The mechanism of polypeptide derived from viral macrophage inflammatory protein II modulates SDF-1α/CXCR4-induced migration].

AIM: To assess whether NT21MP, the synthetic antagonist 21-mer peptide derived from viral macrophage inflammatory protein II inhibits human SKBR3 cells migration by interfering with SDF-1α/CXCR4 signaling. METHODS: The levels of CXCR4 were detected in breast cancer cells SKBR3 and MCF-7 by RT-PCR and immunohistochemistry. The effect of SDF-1α-induced SKBR3 migration (chemotaxis) in the presence and absence of NT21MP was determined using the Boyden chamber migration assay. Intracellular Ca(2+); concentration was measured by fluorometric analysis. Western blot analyses were performed to quantify phosphorylated ERK1/2 and FAK expression levels. RESULTS: The expression of CXCR4 was higher in SKBR3 than MCF-7 cells; SKBR3 migration increased in SDF-1α-treated cells. In contrast, AMD3100, an inhibitor of CXCR4 effectively inhibited SKBR3 migration. SKBR3 migration was decreased when the cells were exposed to NT21MPdose dependently(P<0.05). NT21MP also blocked Ca(2+); influx(P<0.05), an important signal for SKBR3 migration. In addition, NT21MP significantly decreased SDF-1α-induced SKBR3 migration and downregulated SDF-1α-induced express of phospho-ERK1/2 and phospho-FAK(P<0.05). CONCLUSION: The results showed that NT21MP has an inhibitory effect on SDF-1α-induced SKBR3 migration. The plausible mechanism of action could be upstream blockage of Ca(2+); influx and the downstream reduction of ERK1/2 and FAK signals.

[Closed reduction and percutaneous hollow screw fixation with prototypical retractor for the treatment of calcaneal fracture].

OBJECTIVE: To evaluate efficacy of closed reduction and percutaneous hollow screw fixation with prototypical retractor in treating calcaneal fracture. METHODS: From January 2009 to June 2011, 39 patients (43 feet) with calcaneal fracture were treated by closed reduction and percutaneous hollow screw fixation with prototypical retractor. There were 33 males and 6 females, aged from 19 to 61 years with an average of 36.7 years. According to type of Sanders, type II were in 19 feet, type III were in 24 feet. Preoperative and postoperative X-ray were estimated, the data of height, width, Bölher angle, Gissane angle of calcaneous were collected, and ankle function were estimated according to AOFAS system. RESULTS: All patients were followed up from 6 to 36 months with an average of (15.4 +/- 3.1) months. All wounds were healed well, no skin edge necrosis and infections occurred. Before operation, the height of calcaneous was average of (32.45 +/- 3.51) mm, width was (41.60 +/- 2.42) mm, Bölher angle was (8.64 +/- 13.2) degrees and Gissan angle was (136.35 +/- 15.23) degrees; while after operation, the height of calcaneous was average of (43.62 +/- 1.02) mm, width was (38.02 +/- 1.28) mm, Bölher angle was (26.87 +/- 5.32) degrees and Gissan angle was (120.78 +/- 5.34) degrees, and had significanty differences between preoperative and postoperative treatment (P<0.05). AOFAS score was improved from preoperative (35.64 +/- 11.23) to postoperative (76.18 +/- 9.87), and 29 cases got excellent results, 11 good and 3 fair. COMCLUSION: Closed reduction and percutaneous hollow screw fixation auxiliary by the retractor for the treatment is a good way, which has advantages of simple operation, satisfactory reduction fixation, reliable fixation, minimally invasive, less complications and rapid recovery.

[Time resolved UV-Vis absorption spectra of quercetin reacting with various concentrations of sodium hydroxide].

A real time investigation of chemical reaction process of quercetin with various concentrations of sodium hydroxide was performed by using an intensified spectroscopic detector ICCD. The time resolved UV-Vis absorption spectra of 5 x 10(-5) mol x L(-1) quercetin respectively reacting with sodium hydroxide at concentrations of 2, 0.2, 0.1, 0.04 and 0.02 mol x L(-1) were acquired. A total of 200 spectra with the same exposure time of 0.1 ms for each spectrum but different time interval between two consecutive spectra were recorded for each reaction. The first 50 spectra have the time interval of 20 ms, the next 50 have 1 s, and the last 100 have 2 s. Results indicate that quercetin reacted with sodium hydroxide easily and there was an intermediate product formed during the reaction, with different concentrations of reactants, the changes of absorption bands were the same, but the moments at which the changes happened were different and the total reaction time was various from 1 s to 100 s. Spectra recorded showed the disappearing process of the typical bands centered at 254 and 374 nm of pure quercetin, the growing and disappearing processes of a new band centered at 427 nm of the intermediate product, and the growing process of the new band centered at 314 nm of the final product obviously. No other transient spectroscopic data are currently available on the reaction of quercrtin with sodium hydroxide, the results obtained in the present work provide useful experimental data for the study of the microscopic process of the reaction.

[The effect of curcumin on DNA content, mitochondrial transmembrane potential and calcium of rabbit cultured retinal pigment epithelial cells].

OBJECTIVE: To investigate the Change of DNA content (apoptosis rate), mitochondrial transmembrane potential (DeltaPsim) and calcium (Ca(2+)) of rabbit retinal pigment epithelial (RPE) cells cultured with curcumin. METHODS: It was an experimental study. The RPE cells were dissociated from rabbit eyes and cultured. The RPE cells in the 4(th) passage were divided into 2 groups: curcumin group and control group (10% FBS-EMDM contains 0.05% dimethyl sulfoxide). The curcumin group contained 3 mass concentration: 10 mg/L, 15 mg/L and 20 mg/L. The MTT assay was used to evaluate the inhibition effect of RPE cells cultured with curcumin after 24 h, 48 h, 72 h and 96 h respectively. The IC(50) value in 24 h, 48 h, 72 h and 96 h were gotten by Linear Regression. Flow cytometry was performed to detect the change of DNA content (apoptosis rate), DeltaPsim and Ca(2+) of RPE cells cultured with curcumin (15 mg/L) after 8 h, 24 h, 48 h and 72 h respectively. RESULTS: RPE cells were significantly inhibited by curcumin in a dose dependent and time dependent manner. The IC(50) value of curcumin at 24 h, 48 h, 72 h and 96 h was 29.31 mg/L, 17.50 mg/L, 13.24 mg/L and 10.99 mg/L respectively. Ca(2+) was significantly increased at 8 h, 24 h, 48 h and 72 h after cultured with curcumin (15 mg/L) than that of the control group respectively (t = 7.50, 10.61, 20.74, 21.14, P < 0.01), and DeltaPsim was significantly decreased at 8 h, 24 h, 48 h and 72 h after cultured with curcumin (15 mg/L) than that of the control group respectively (t = 7.50, 11.74, 14.91, 15.29, P < 0.01). There was no change of DNA content in RPE cells at 8h after cultured with curcumin (15 mg/L), but significantly lower than that of the control group at 24 h, 48 h and 72 h respectively (t = 10.00, 14.68, 13.68, P < 0.01). CONCLUSION: The apoptosis of RPE cells induced by curcumin is caused by increase of Ca(2+) and decrease of DeltaPsim that causes decrease of DNA content. The RPE cells are significantly inhibited by curcumin, which may become a potential drug to prevent and treat proliferative vitreoretinopathy.

[Transient UV absorption spectra of artemisinin reacting with sodium hydroxide].

UV absorption spectrum of artemisinin and transient absorption spectra of various concentrations of artemisinin reacting with sodium hydroxide were measured by using an intensified spectroscopic detector ICCD. The exposure time of each spectrum was 0.1 ms. Results indicate that artemisinin has an obvious UV absorption band centered at 212.52 nm and can react with sodium hydroxide easily. All absorption spectra of different concentrations of artemisinin reacting with sodium hydroxide have the similar changes, but the moment at which the changes happened is different. After adding sodium hydroxide into artemisinin in ethanol solution, there was a new absorption band centered at 288 nm appearing firstly. As reaction went on, the intensity of another absorption band centered at 260 nm increased gradually. At the end of the reaction, a continuous absorption band from 200 to 350 nm with the peak at 245 nm formed finally. No other transient absorption spectral data are available on the reaction of artemisinin with sodium hydroxide currently. The new spectral information obtained in this experiment provides very important experimental basis for understanding the properties of artemisinin reacting with alkaline medium and is useful for correctly using of artemisinin as a potential anticancer drug.