Changsha, China
Changsha, China

Hunan University , located in Changsha, Hunan province, is one of the oldest and most important national universities in China. Wikipedia.

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News Article | May 26, 2017
Site: www.prnewswire.com

Highlights for the First Quarter of 2017 Adoption of ASC 606, Revenue from Contracts with Customers In May 2014, the FASB issued a new standard related to revenue recognition, and recently issued several amendments to the standard. The new revenue standard will be effective beginning on January 1, 2018, and adoption as of the original effective date of January 1, 2017 is permitted. The guidance permits two methods of adoption: retrospectively to each prior reporting period presented (full retrospective method), or retrospectively with the cumulative effect of initially applying the guidance recognized at the date of initial application (the cumulative catch-up transition method). We adopted this new revenue standard effective January 1, 2017 by applying the full retrospective method. Also since the beginning of fiscal year 2017, we have implemented certain changes with our tour operators and our role in the organized tour arrangements has changed from a principal into an agent. As a result of adopting the new accounting standard and the change of our role, revenue from the organized tours will be mainly recognized on a net basis. Also the revenue standard changed the timing of revenue recognition for packaged-tour services from the tour's end to the departure day of the tour. Under ASC 606 Revenue from Contracts with Customers, substantially all revenues from our organized tours for the year ended December 31, 2016 continued to be recognized on a gross basis because of our principal role for these organized tours up to the end of 2016. To increase comparability of operating results and aid investors to better understand our business performance and operating trends, we have provided the following comparison of revenues, cost of revenues and gross profit for the first quarter of 2017 with relevant Non-GAAP adjusted data for corresponding periods in 2016: Additional information regarding our Non-GAAP definition and reconciliations of GAAP and Non-GAAP results are provided at the end of this announcement. Mr. Donald Yu, Tuniu's co-founder, Chairman and Chief Executive Officer, said, "We are pleased to report a strong first quarter to start off 2017. Our net revenue increased by over 60% year-over-year while our margins improved considerably as we further strengthened our number one position in the online leisure travel market in China. In 2017, Tuniu will primarily focus on its core operation and innovation to make further improvements to its customer service, product and technology. For customer service, we will fully implement our "one-stop consultant" feature so that a single dedicated customer service representative can help plan and book a customer's trip, and resolve questions during their trip. This will give each customer a better and more personal experience when they travel with Tuniu and increase the efficiency of our customer service. " Mr. Alex Yan, Tuniu's co-founder, President and Chief Operating Officer, said, "Big data analytics continue to be used across our operation. We have strengthened our usage of big data by pushing products to our customers based on their location and historical preferences. On the sales and marketing side, we have increased the efficiency of our campaigns by leveraging our data from previous campaigns and allocating our budget to channels with higher returns." Mr. Conor Yang, Tuniu's Chief Financial Officer, said, "Starting from the second half of 2016, we have made several improvements to the efficiency of our business. Our focus on improving operational efficiency and realizing economies of scale has helped us significantly reduce our net loss both on an absolute basis and as a percentage of revenue. As we continue to both improve our gross margin and control costs, our path to profitability becomes increasingly clear." Net revenues were RMB456.0 million (US$66.3 million) in the first quarter of 2017, representing a year-over-year increase of 60.4%, compared with Non-GAAP net revenues, from the corresponding period in 2016. Cost of revenues was RMB204.7 million (US$29.7 million) in the first quarter of 2017, representing a year-over-year increase of 6.9%, compared with Non-GAAP cost of revenues, from the corresponding period in 2016. As a percentage of net revenues, cost of revenues was 44.9% in the first quarter of 2017, compared to 67.4% as a percentage of Non-GAAP net revenues in the corresponding period in 2016. Gross profit was RMB251.3 million (US$36.5 million) in the first quarter of 2017, representing a year-over-year increase of 170.8%, compared with Non-GAAP gross profit, from the corresponding period in 2016. The increase in gross profit was primarily due to the economies of scale and optimization of our supply chain management. Operating expenses were RMB559.3 million (US$81.3 million) in the first quarter of 2017, representing a year-over-year decrease of 13.7% from the corresponding period in 2016. Share-based compensation expenses and amortization of acquired intangible assets, which were allocated to operating expenses, were RMB60.8 million (US$8.8 million) in the first quarter of 2017. Non-GAAP operating expenses, which excluded share-based compensation expenses and amortization of acquired intangible assets, were RMB498.5 million (US$72.4 million) in the first quarter of 2017, representing a year-over-year decrease of 15.6%. Loss from operations was RMB308.0 million (US$44.7 million) in the first quarter of 2017, compared to a loss from operations of RMB556.9 million in the first quarter of 2016. Non-GAAP loss from operations, which excluded share-based compensation expenses and amortization of acquired intangible assets, was RMB246.9 million (US$35.9 million) in the first quarter of 2017. Net loss was RMB287.4 million (US$41.7 million) in the first quarter of 2017, compared to a net loss of RMB538.5 million in the first quarter of 2016. Non-GAAP net loss, which excluded share-based compensation expenses and amortization of acquired intangible assets, was RMB226.2 million (US$32.9 million) in the first quarter of 2017. Net loss attributable to ordinary shareholders was RMB288.2 million (US$41.9 million) in the first quarter of 2017, compared to a net loss attributable to ordinary shareholders of RMB535.8 million in the first quarter of 2016. Non-GAAP net loss attributable to ordinary shareholders, which excluded share-based compensation expenses and amortization of acquired intangible assets, was RMB227.1 million (US$33.0 million) in the first quarter of 2017. As of March 31, 2017, the Company had cash and cash equivalents, restricted cash and short-term investments of RMB4.2 billion (US$613.8 million). For the second quarter of 2017, Tuniu expects to generate RMB442.7 million to RMB457.6 million of net revenues, which represents 48% to 53% growth year-over-year compared with Non-GAAP net revenues in the corresponding period in 2016. This forecast reflects Tuniu's current and preliminary view on the industry and its operations, which is subject to change. Appointment of New Board of Directors Tuniu also announced that effective May 25, 2017, Mr. Shengli Hu and Mr. Tao Yang were appointed as directors to the Company's board of directors, replacing Mr. Haoyu Shen and Mr. James Jiangzhang Liang, who have resigned from the board on the same date. Mr. Shengli Hu also replaced Mr. Haoyu Shen as a member of the Company's compensation committee. Mr. Shengli Hu has served as the President of JD.com's 3C business unit since January 2016. Mr. Hu joined JD.com in January 2014 and was in charge of the telecommunication department. Mr. Hu has extensive experience in operations within the telecommunication industry. Prior to joining JD.com, Mr. Hu served as the Vice President of FunTalk China Holdings Limited from 2011 until 2013. Mr. Hu has also served in various key roles during his tenure in China Unicom. Mr. Hu received a master's degree in business administration from Hunan University. Mr. Tao Yang currently serves as Senior Vice President of Ctrip.com International, Ltd in charge of its Travel Business Unit. Mr. Yang has held a number of technical and managerial positions after joining in Ctrip.com in 2000. Mr. Yang received an EMBA degree from China Europe International Business School and a bachelor's degree in mechanical engineering from Shanghai Jiaotong University. Tuniu's management will hold an earnings conference call at 8:00 am U.S. Eastern Time, on May 26, 2017, (8:00 pm, Beijing/Hong Kong Time, on May 26, 2017) to discuss the first quarter 2017 financial results. To participate in the conference call, please dial the following numbers: A telephone replay will be available one hour after the end of the conference through June 2, 2017. The dial-in details are as follows: Additionally, a live and archived webcast of the conference call will also be available on the Company's investor relations website at http://ir.tuniu.com. Tuniu (Nasdaq: TOUR) is a leading online leisure travel company in China that offers a large selection of packaged tours, including organized and self-guided tours, as well as travel-related services for leisure travelers through its website tuniu.com and mobile platform. Tuniu has over 1,700,000 stock keeping units (SKUs) of packaged tours, covering over 160 countries worldwide and all the popular tourist attractions in China. Tuniu provides one-stop leisure travel solutions and a compelling customer experience through its online platform and offline service network. For more information, please visit http://ir.tuniu.com. This press release contains forward-looking statements made under the "safe harbor" provisions of Section 21E of the Securities Exchange Act of 1934, as amended, and the U.S. Private Securities Litigation Reform Act of 1995. These forward-looking statements can be identified by terminology such as "will," "expects," "anticipates," "future," "intends," "plans," "believes," "estimates," "confident" and similar statements. Tuniu may also make written or oral forward-looking statements in its reports filed with or furnished to the U.S. Securities and Exchange Commission, in its annual report to shareholders, in press releases and other written materials and in oral statements made by its officers, directors or employees to third parties. Any statements that are not historical facts, including statements about Tuniu's beliefs and expectations, are forward-looking statements that involve factors, risks and uncertainties that could cause actual results to differ materially from those in the forward-looking statements. Such factors and risks include, but are not limited to the following: Tuniu's goals and strategies; the growth of the online leisure travel market in China; the demand for Tuniu's products and services; its relationships with customers and travel suppliers; the Company's ability to offer competitive travel products and services; Tuniu's future business development, results of operations and financial condition; competition in the online travel industry in China; relevant government policies and regulations relating to the Company's structure, business and industry; and the general economic and business condition in China and elsewhere. Further information regarding these and other risks, uncertainties or factors is included in the Company's filings with the U.S. Securities and Exchange Commission. All information provided in this press release is current as of the date of the press release, and Tuniu does not undertake any obligation to update such information, except as required under applicable law. To supplement the Company's unaudited consolidated financial results presented in accordance with United States Generally Accepted Accounting Principles ("GAAP"), the Company has provided Non-GAAP information related to net revenue, cost of revenues, research and product development expenses, sales and marketing expenses, general and administrative expenses, operating expenses, loss from operations, net loss, net loss attributable to ordinary shareholders, net loss per ordinary share attributable to ordinary shareholders-basic and diluted and net loss per ADS, which excludes adjustment on net basis and timing of revenue recognition as in 2017, share-based compensation expenses and amortization of acquired intangible assets. We believe that the Non-GAAP financial measures used in this press release are useful for understanding and assessing underlying business performance and operating trends, and management and investors benefit from referring to these Non-GAAP financial measures in assessing our financial performance and when planning and forecasting future periods. For more information on these Non-GAAP financial measures, please see the table captioned "Reconciliations of GAAP and Non-GAAP Results" set forth at the end of this press release. A limitation of using Non-GAAP financial measures excluding share-based compensation expenses and amortization of acquired intangible assets is that share-based compensation expenses and amortization of acquired intangible assets have been – and will continue to be – significant recurring expenses in the Company's business. You should not view Non-GAAP results on a stand-alone basis or as a substitute for results under GAAP, or as being comparable to results reported or forecasted by other companies. For investor and media inquiries, please contact: To view the original version on PR Newswire, visit:http://www.prnewswire.com/news-releases/tuniu-announces-unaudited-first-quarter-2017-financial-results-300464491.html


News Article | May 26, 2017
Site: en.prnasia.com

Tuniu Corporation (NASDAQ:TOUR) ("Tuniu" or the "Company"), a leading online leisure travel company in China, today announced its unaudited financial results for the first quarter ended March 31, 2017. Highlights for the First Quarter of 2017 Adoption of ASC 606, Revenue from Contracts with Customers In May 2014, the FASB issued a new standard related to revenue recognition, and recently issued several amendments to the standard. The new revenue standard will be effective beginning on January 1, 2018, and adoption as of the original effective date of January 1, 2017 is permitted. The guidance permits two methods of adoption: retrospectively to each prior reporting period presented (full retrospective method), or retrospectively with the cumulative effect of initially applying the guidance recognized at the date of initial application (the cumulative catch-up transition method). We adopted this new revenue standard effective January 1, 2017 by applying the full retrospective method. Also since the beginning of fiscal year 2017, we have implemented certain changes with our tour operators and our role in the organized tour arrangements has changed from a principal into an agent. As a result of adopting the new accounting standard and the change of our role, revenue from the organized tours will be mainly recognized on a net basis. Also the revenue standard changed the timing of revenue recognition for packaged-tour services from the tour's end to the departure day of the tour. Under ASC 606 Revenue from Contracts with Customers, substantially all revenues from our organized tours for the year ended December 31, 2016 continued to be recognized on a gross basis because of our principal role for these organized tours up to the end of 2016. To increase comparability of operating results and aid investors to better understand our business performance and operating trends, we have provided the following comparison of revenues, cost of revenues and gross profit for the first quarter of 2017 with relevant Non-GAAP adjusted data for corresponding periods in 2016: Additional information regarding our Non-GAAP definition and reconciliations of GAAP and Non-GAAP results are provided at the end of this announcement. Mr. Donald Yu, Tuniu's co-founder, Chairman and Chief Executive Officer, said, "We are pleased to report a strong first quarter to start off 2017. Our net revenue increased by over 60% year-over-year while our margins improved considerably as we further strengthened our number one position in the online leisure travel market in China. In 2017, Tuniu will primarily focus on its core operation and innovation to make further improvements to its customer service, product and technology. For customer service, we will fully implement our "one-stop consultant" feature so that a single dedicated customer service representative can help plan and book a customer's trip, and resolve questions during their trip. This will give each customer a better and more personal experience when they travel with Tuniu and increase the efficiency of our customer service. " Mr. Alex Yan, Tuniu's co-founder, President and Chief Operating Officer, said, "Big data analytics continue to be used across our operation. We have strengthened our usage of big data by pushing products to our customers based on their location and historical preferences. On the sales and marketing side, we have increased the efficiency of our campaigns by leveraging our data from previous campaigns and allocating our budget to channels with higher returns." Mr. Conor Yang, Tuniu's Chief Financial Officer, said, "Starting from the second half of 2016, we have made several improvements to the efficiency of our business. Our focus on improving operational efficiency and realizing economies of scale has helped us significantly reduce our net loss both on an absolute basis and as a percentage of revenue. As we continue to both improve our gross margin and control costs, our path to profitability becomes increasingly clear." Net revenues were RMB456.0 million (US$66.3 million) in the first quarter of 2017, representing a year-over-year increase of 60.4%, compared with Non-GAAP net revenues, from the corresponding period in 2016. Cost of revenues was RMB204.7 million (US$29.7 million) in the first quarter of 2017, representing a year-over-year increase of 6.9%, compared with Non-GAAP cost of revenues, from the corresponding period in 2016. As a percentage of net revenues, cost of revenues was 44.9% in the first quarter of 2017, compared to 67.4% as a percentage of Non-GAAP net revenues in the corresponding period in 2016. Gross profit was RMB251.3 million (US$36.5 million) in the first quarter of 2017, representing a year-over-year increase of 170.8%, compared with Non-GAAP gross profit, from the corresponding period in 2016. The increase in gross profit was primarily due to the economies of scale and optimization of our supply chain management. Operating expenses were RMB559.3 million (US$81.3 million) in the first quarter of 2017, representing a year-over-year decrease of 13.7% from the corresponding period in 2016. Share-based compensation expenses and amortization of acquired intangible assets, which were allocated to operating expenses, were RMB60.8 million (US$8.8 million) in the first quarter of 2017. Non-GAAP operating expenses, which excluded share-based compensation expenses and amortization of acquired intangible assets, were RMB498.5 million (US$72.4 million) in the first quarter of 2017, representing a year-over-year decrease of 15.6%. Loss from operations was RMB308.0 million (US$44.7 million) in the first quarter of 2017, compared to a loss from operations of RMB556.9 million in the first quarter of 2016. Non-GAAP loss from operations, which excluded share-based compensation expenses and amortization of acquired intangible assets, was RMB246.9 million (US$35.9 million) in the first quarter of 2017. Net loss was RMB287.4 million (US$41.7 million) in the first quarter of 2017, compared to a net loss of RMB538.5 million in the first quarter of 2016. Non-GAAP net loss, which excluded share-based compensation expenses and amortization of acquired intangible assets, was RMB226.2 million (US$32.9 million) in the first quarter of 2017. Net loss attributable to ordinary shareholders was RMB288.2 million (US$41.9 million) in the first quarter of 2017, compared to a net loss attributable to ordinary shareholders of RMB535.8 million in the first quarter of 2016. Non-GAAP net loss attributable to ordinary shareholders, which excluded share-based compensation expenses and amortization of acquired intangible assets, was RMB227.1 million (US$33.0 million) in the first quarter of 2017. As of March 31, 2017, the Company had cash and cash equivalents, restricted cash and short-term investments of RMB4.2 billion (US$613.8 million). For the second quarter of 2017, Tuniu expects to generate RMB442.7 million to RMB457.6 million of net revenues, which represents 48% to 53% growth year-over-year compared with Non-GAAP net revenues in the corresponding period in 2016. This forecast reflects Tuniu's current and preliminary view on the industry and its operations, which is subject to change. Appointment of New Board of Directors Tuniu also announced that effective May 25, 2017, Mr. Shengli Hu and Mr. Tao Yang were appointed as directors to the Company's board of directors, replacing Mr. Haoyu Shen and Mr. James Jiangzhang Liang, who have resigned from the board on the same date. Mr. Shengli Hu also replaced Mr. Haoyu Shen as a member of the Company's compensation committee. Mr. Shengli Hu has served as the President of JD.com's 3C business unit since January 2016. Mr. Hu joined JD.com in January 2014 and was in charge of the telecommunication department. Mr. Hu has extensive experience in operations within the telecommunication industry. Prior to joining JD.com, Mr. Hu served as the Vice President of FunTalk China Holdings Limited from 2011 until 2013. Mr. Hu has also served in various key roles during his tenure in China Unicom. Mr. Hu received a master's degree in business administration from Hunan University. Mr. Tao Yang currently serves as Senior Vice President of Ctrip.com International, Ltd in charge of its Travel Business Unit. Mr. Yang has held a number of technical and managerial positions after joining in Ctrip.com in 2000. Mr. Yang received an EMBA degree from China Europe International Business School and a bachelor's degree in mechanical engineering from Shanghai Jiaotong University. Tuniu's management will hold an earnings conference call at 8:00 am U.S. Eastern Time, on May 26, 2017, (8:00 pm, Beijing/Hong Kong Time, on May 26, 2017) to discuss the first quarter 2017 financial results. To participate in the conference call, please dial the following numbers: A telephone replay will be available one hour after the end of the conference through June 2, 2017. The dial-in details are as follows: Additionally, a live and archived webcast of the conference call will also be available on the Company's investor relations website at http://ir.tuniu.com. Tuniu (Nasdaq:TOUR) is a leading online leisure travel company in China that offers a large selection of packaged tours, including organized and self-guided tours, as well as travel-related services for leisure travelers through its website tuniu.com and mobile platform. Tuniu has over 1,700,000 stock keeping units (SKUs) of packaged tours, covering over 160 countries worldwide and all the popular tourist attractions in China. Tuniu provides one-stop leisure travel solutions and a compelling customer experience through its online platform and offline service network. For more information, please visit http://ir.tuniu.com. This press release contains forward-looking statements made under the "safe harbor" provisions of Section 21E of the Securities Exchange Act of 1934, as amended, and the U.S. Private Securities Litigation Reform Act of 1995. These forward-looking statements can be identified by terminology such as "will," "expects," "anticipates," "future," "intends," "plans," "believes," "estimates," "confident" and similar statements. Tuniu may also make written or oral forward-looking statements in its reports filed with or furnished to the U.S. Securities and Exchange Commission, in its annual report to shareholders, in press releases and other written materials and in oral statements made by its officers, directors or employees to third parties. Any statements that are not historical facts, including statements about Tuniu's beliefs and expectations, are forward-looking statements that involve factors, risks and uncertainties that could cause actual results to differ materially from those in the forward-looking statements. Such factors and risks include, but are not limited to the following: Tuniu's goals and strategies; the growth of the online leisure travel market in China; the demand for Tuniu's products and services; its relationships with customers and travel suppliers; the Company's ability to offer competitive travel products and services; Tuniu's future business development, results of operations and financial condition; competition in the online travel industry in China; relevant government policies and regulations relating to the Company's structure, business and industry; and the general economic and business condition in China and elsewhere. Further information regarding these and other risks, uncertainties or factors is included in the Company's filings with the U.S. Securities and Exchange Commission. All information provided in this press release is current as of the date of the press release, and Tuniu does not undertake any obligation to update such information, except as required under applicable law. To supplement the Company's unaudited consolidated financial results presented in accordance with United States Generally Accepted Accounting Principles ("GAAP"), the Company has provided Non-GAAP information related to net revenue, cost of revenues, research and product development expenses, sales and marketing expenses, general and administrative expenses, operating expenses, loss from operations, net loss, net loss attributable to ordinary shareholders, net loss per ordinary share attributable to ordinary shareholders-basic and diluted and net loss per ADS, which excludes adjustment on net basis and timing of revenue recognition as in 2017, share-based compensation expenses and amortization of acquired intangible assets. We believe that the Non-GAAP financial measures used in this press release are useful for understanding and assessing underlying business performance and operating trends, and management and investors benefit from referring to these Non-GAAP financial measures in assessing our financial performance and when planning and forecasting future periods. For more information on these Non-GAAP financial measures, please see the table captioned "Reconciliations of GAAP and Non-GAAP Results" set forth at the end of this press release. A limitation of using Non-GAAP financial measures excluding share-based compensation expenses and amortization of acquired intangible assets is that share-based compensation expenses and amortization of acquired intangible assets have been – and will continue to be – significant recurring expenses in the Company's business. You should not view Non-GAAP results on a stand-alone basis or as a substitute for results under GAAP, or as being comparable to results reported or forecasted by other companies. For investor and media inquiries, please contact: To view the original version on PR Newswire, visit:http://www.prnewswire.com/news-releases/tuniu-announces-unaudited-first-quarter-2017-financial-results-300464491.html


Patent
Hunan University and Changsha Boli Electrical Corporation | Date: 2014-09-15

A steady state control method for a three-phase double-mode inverter. Off-grid steady state control is composed of outer loop power droop control, voltage feed-forward quasi-resonant control, and inner current loop dead-beat control. Therefore, the response speed of the inverter is raised, and the influence caused by the load fluctuation of a micro-grid is inhibited. Based on the off-grid steady state control, grid-connected steady state control introduces phase lead control to the power droop control. Therefore, the output voltage of the inverter is always slightly ahead of the power grid voltage, which avoids the energy pour backward phenomenon of the inverter due to a phase error, and realizes stable and reliable running in the grid-connected mode.


An intelligent and information multi-vehicle collaboratively operating municipal refuse collection and transfer system and method are provided. The system comprises an automated system with multiple-degree of freedom intelligent dustbin grabbing, an operating system with two types of refuse vehicles collaborating, a multi-vehicle collaborative operation information system, and a fixed-point refuse collection operation confirmation and remote monitoring information management system for coordinating overall operation of the systems. The automated system with multiple-degree of freedom intelligent dustbin grabbing system is used for the refuse vehicles to automatically collect dustbins; the operating system with two types of refuse vehicles collaborating comprises a plurality of small- and medium-sized refuse vehicles and large capacity refuse vehicles. The small- and medium-sized refuse vehicles collect refuse in the dustbins according to multi-vehicle collaborative operation information with the support of the multi-vehicle collaborative operation information system, and the large capacity refuse vehicles are used to dock with the collected refuse and transport the refuse out of town with the support of the multi-vehicle collaborative operation information system. The method is the implementation of the above system. The system and method have good operability and high degree of intelligence and provide good results of refuse disposal.


Liu Q.,Hunan University
Nature Nanotechnology | Year: 2017

Cells interact with the extracellular environment through molecules expressed on the membrane. Disruption of these membrane-bound interactions (or encounters) can result in disease progression. Advances in super-resolution microscopy have allowed membrane encounters to be examined, however, these methods cannot image entire membranes and cannot provide information on the dynamic interactions between membrane-bound molecules. Here, we show a novel DNA probe that can transduce transient membrane encounter events into readable cumulative fluorescence signals. The probe, which translocates from one anchor site to another, mimicking motor proteins, is realized through a toehold-mediated DNA strand displacement reaction. Using this probe, we successfully monitored rapid encounter events of membrane lipid domains using flow cytometry and fluorescence microscopy. Our results show a preference for encounters within the same lipid domains. © 2017 Nature Publishing Group


BACKGROUND: Prenyl flavonoid icaritin (1) and β-anhydroicaritin (2) are two natural products with important biological and pharmacological effects. such as antiosteoporosis, estrogen regulation and antitumor properties.OBJECTIVE: The present study investigates the synthesis and cytotoxic activities on three Human cancer cell lines (Hela, HCC1954 and SK-OV-3) of icaritin and β-anhydroicaritin Mannich base derivatives in vitro models.METHOD: Preylated flavonoid icaritin (1) upon treatment with formic acid under microwave assistance gave another natural product β-anhydroicaritin (2) in good yield (89%). Based on Mannich reaction of 1 or 2 with various secondary amines and formaldehyde, two series eighteen new 6-aminomethylated flavonoids Mannich base derivatives 3-11 and 12-20 were synthesized. Their cytotoxic potential against three human cancer cell lines (Hela, HCC1954 and SK-OV-3) were evaluated by the standard MTT method with cis-Platin and Paclitaxel as positive control.RESULTS: Our research showed that most of these flavonoid Mannich base derivatives displayed equal or higher (lower IC50 values) cytotoxic activities than the positive control cis-Platin. Some compounds possess the IC50 value below 10µM. Compounds 6-(diisopropylamino)methyl- and 6-morpholinylmethyl substituted β-anhydroicaritin (15 and 19) showed selective cytotoxicity against HCC1954 cells (IC50 12.688 µM) and Hela cells (IC50 6.543 µM) respectively.CONCLUSION: Our finding most of icaritin and β-anhydroicaritin Mannich base derivatives possessing moderate to potent cytotoxicity against these three cancer cells (Hela, HCC1954 and SK-OV-3). Compound 15 and 19 showed selective cytotoxicity against HCC1954 cells and Hela cells respectively, they are potential and selective anticancer agent and worthy of further development.


Wang K.,Hunan University
The Analyst | Year: 2013

Living cell studies can offer tremendous opportunities for biological and disease studies. Due to their high sensitivity and selectivity, minimum interference with living biological systems, ease of design and synthesis, fluorescent nucleic acid probes (FNAPs) have been widely used in living cell studies, such as for intracellular detection, cell detection, and cell-to-cell communication. Here, we review the general requirements and the recent developments in FNAPs for living cell studies. We broadly classify these designs as hybridization probes and aptamer probes. For hybridization probes, we describe recently developed designs, such as nanomaterial-based and amplification-based hybridization probes. For aptamer probes, we discuss four general paradigms that have appeared most frequently in the literature: nanomaterial-based, nanomachine-based, cell surface-anchored and activatable aptamer probe designs in vivo. FNAPs promise to open up new and exciting opportunities in biological marks detection for a wide range of biological and medical applications.


Yu X.,Hunan University | Lu B.,Hunan University | Xu Z.,Hunan University
Advanced Materials | Year: 2014

Nanohoneycomb-like strongly coupled CoMoO4-3D graphene hybird electrodes are synthesized for supercapacitors which exhibit excellent specific capacitance and superior long-term cycle stability. The supercapacitor device can power a 5 mm-diameter LED efficiently for more than 3 min with a charging time of only 2 s, and shows high energy densities and good cycle stability. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Herein, we demonstrated a new optical microscopy method to selectively image small-size gold nanoparticles (GNPs) inside noisy living cells through determination of the difference image between the probe beam (illuminated at the resonance wavelength of GNPs, 532 nm) and the reference beam (illuminated at 473 nm). From computer simulation and single-particle imaging experiments, we demonstrated that GNPs with a diameter of 45 nm could be selectively imaged in the GNPs/cell lysates mixture and inside living cells by dual-wavelength difference (DWD) imaging. The diffusion dynamics of nucleic acids functionalized GNPs on cell membranes and the internalization kinetics of these GNPs by living cells were explored with this method. Our real-time tracking experiments showed that statistically 80% of GNPs were under restricted diffusion on the cell membrane. The cell cytoskeleton fence effect, as observed in the single-particle tracking experiments, may be one of the main factors for the restricted diffusion mode.


We present here a highly selective and sensitive label-free method to detect Hg(2+) ions in aqueous solution by using DNA molecular machine-based fluorescent Ag nanoclusters (AgNCs). This mechanism is based on the Hg(2+) ions triggering machine-like operations of DNA and the "product" of the machine being used to stabilize fluorescent AgNCs. In this method, a tailored DNA, containing a sequence for Hg(2+) ions recognition, a sequence-specific nicking site for Nb BbvC I and a sequence complementary to the DNA as a template for the synthesis of fluorescent AgNCs, was firstly designed. In the presence of Hg(2+) ions, the machine's function operations were triggered. A series of machine-like operations, including replication, scission, and displacement then occurred with the addition of polymerase/dNTPs/Nb BbvC I, which manufactured lots of "product" DNA. The "product" DNA could act as a template for the preparation of fluorescent AgNCs. Thus the fluorescence of the AgNCs could be used as a signal transduction of this DNA machine, which was related to the concentration of the Hg(2+) ions. The repeated synthesis of the "product" and its template effect for AgNCs synthesis led to signal amplification in the assay of Hg(2+) ions. A linear response to the concentration of Hg(2+) ions was observed in the range from 0.08 nM to 20 nM and a detection limit of 0.08 nM was obtained. By contrast, the operation of the machine could not be executed in an Hg(2+) ion-free system. Moreover, the detection was not only label-free but also specific for Hg(2+) ions without being affected by other metal ions.

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