5-Methyl-3,3-bis-(4-methyl-piperazin-1-yl)-1-[2-(4-methyl-piperazin-1-yl)eth-yl]indolin-2-one.

In the title compound, C(26)H(43)N(7)O, each piperazine ring adopts a chair conformation. Two 1-methyl-piperazine rings bond to one Csp(3) of the pyrrole ring via the piperazine N atoms, while the third one links to the N atom of the indolin-2-one unit through a flexible ethyl group with an almost syn conformation. In the crystal, mol-ecules are connected through methyl-ene-carbonyl C-H⋯O inter-actions into an infinite chain along the c axis. The almost parallel arrays are stacked, forming a three-dimensional framework.

A high-throughput dielectrophoresis-based cell electrofusion microfluidic device.

A high-throughput cell electrofusion microfluidic chip has been designed, fabricated on a silicon-on-insulator wafer and tested for in vitro cell fusion under a low applied voltage. The developed chip consists of six individual straight microchannels with a 40-µm thickness conductive highly doped Si layer as the microchannel wall. In each microchannel, there are 75 pairs of counter protruding microelectrodes, between which the cell electrofusion is performed. The entire highly doped Si layer is covered by a 2-µm thickness aluminum film to maintain a consistent electric field between different protruding microelectrode pairs. A 150-nm thickness SiO2 film is subsequently deposited on the top face of each protruding microelectrode for better biocompatibility. Owing to the short distance between two counter protruding microelectrodes, a high electric field can be generated for cell electrofusion with a low voltage imposed across the electrodes. Both mammalian cells and plant protoplasts were used to test the cell electrofusion. About 42-68% cells were aligned to form cell-cell pairs by the dielectrophoretic force. After cell alignment, cell pairs were fused to form hybrid cells under the control of cell electroporation and electrofusion signals. The averaged fusion efficiency in the paired cells is above 40% (the highest was about 60%), which is much higher than the traditional polyethylene glycol method (<5%) and traditional electrofusion methods (∼12%). An individual cell electrofusion process could be completed within 10 min, indicating a capability of high throughput.

Rapid analysis of alpha-fetoprotein by chemiluminescence microfluidic immunoassay system based on super-paramagnetic microbeads.

A rapid and sensitive chemiluminescence microfluidic immunoassay system based on super-paramagnetic microbeads for determination of alpha-fetoprotein (AFP) is described. In this system we use CO(2) laser to fabricate microfluidic chip, and use super-paramagnetic microbeads as solid carrier of antibody, chemiluminescence as detection signal. With this system we can perform AFP analysis within 20 min, and the linear range of AFP concentration is 1 approximately 800 ng/mL, the detection limit is 0.23 ng/mL. By this method no separation or preconcentration steps are needed. Most of all, the chip can be reused.

Study of the inhibitory effect of fatty acids on the interaction between DNA and polymerase beta.

The binding of human DNA polymerase beta (pol beta) to DNA template-primer duplex and single-stranded DNA in the absence or presence of pol beta inhibitors has been studied using a surface plasmon resonance biosensor. Two fatty acids, linoleic acid and nervonic acid, were used as potent pol beta inhibitors. In the interaction between pol beta and DNA, pol beta could bind to ssDNA in a single binding mode, but bound to DNA template-primer duplexes in a parallel mode. Both pol beta inhibitors prevented the binding of pol beta to the single strand overhang and changed the binding from parallel to single mode. The affinities of pol beta to the template-primer duplex region in the presence of nervonic acid or linoleic acid were decreased by 20 and 5 times, respectively. The significant inhibitory effect of nervonic acid on the pol beta-duplex interaction was due to both a 2-fold decrease in the association rate and a 9-fold increase in the dissociation rate. In the presence of linoleic acid, no significant change of association rate was observed, and the decrease in binding affinity of pol beta to DNA was mainly due to 7-fold increase in the dissociation rate.

[Folate receptor-mediated antitumor drugs].

Folate receptor (FR) is over-expressed in a variety of human cancers and it is seldom expressed or found in normal tissues. Therefore, folate receptor-mediated antitumor drugs can be targeted specially to the FR-positive tumor cells. This strategy improves the selectivity of drugs which may destroy the normal tissues in traditional chemotherapeutics. This review provides the delivery mechanism of FR-mediated antitumor drugs and highlights the novel folate-drug conjugates and their activities.

[Expression of vascular endothelial growth factor C in pancreatic cancer and its effect upon lymph node metastasis].

OBJECTIVE: To investigate the expression of vascular endothelial growth factor C (VEGF-C) and the effect of antisense oligonucleotide (ASODN) upon lymph node metastasis of pancreatic cancer cell. METHODS: We selected 15 cases of human pancreatic cancer and detected the expression of VEGF-C in primary tumor and lymph node metastasis tissues with immunohistochemistry. Meanwhile, the spontaneous lymphatic metastasis model in nude mice was established with orthotopic implantation for the human pancreatic cancer cell line PANC-1, isolation and culture of primary tumor and spontaneous lymphatic metastasis. The effect of VEGF-C special ASODN upon the apoptosis of pancreatic cancer cell derived from primary tumor and spontaneous lymphatic metastasis were detected by reverse transcription polymerase chain reaction (RT-PCR), enzyme linked immunosorbent assay (ELISA), flow cytometer and terminal deoxynucleotidyl transferase mediated-dUTP nick end labeling (TUNEL). RESULTS: In tissues of human pancreatic cancer, the values of VEGF-C on lymph nodes metastasis were more higher than primary tumor (P < 0.05). About the expression of VEGF-C on pancreatic cancer cell derived from spontaneous lymphatic metastasis and primary tumor in nude mice model, the mRNA levels of VEGF-C were 0.87 +/- 0.11 and 0.61 +/- 0.15 respectively, the VEGF-C levels in culture supernatants were (1682 +/- 157) pg/ml and (1404 +/- 128) pg/ml. The expression of VEGF-C on pancreatic cancer cells derived from lymphatic metastasis were also more higher than primary tumor (P < 0.05). In vitro and vivo, transfection of VEGF-C ASODN decreased the expression of VEGF-C in pancreatic cancer cell. In control group, scramble-sense oligonucleotide (SODN) group and ASODN group, the apoptosis rates of pancreatic cancer cells derived from lymph node metastasis were (2.8 +/- 1.0)%, (5.0 +/- 2.1)%, (13.2 +/- 2.2)% respectively in vitro, and were (1.8 +/- 0.5)%, (2.0 +/- 0.7)%, (4.4 +/- 1.0)% respectively in vivo, the apoptosis was increased significantly after transfection of VEGF-C ASODN (all P < 0.01). But pancreatic cancer cells derived from primary tumor were not effected (all P > 0.05). CONCLUSION: In human pancreatic cancer and nude mice model, the expression of VEGF-C on lymphatic metastasis was higher than primary tumor. The apoptosis of pancreatic cancer cells derived from spontaneous lymphatic metastasis were promoted by transfection of VEGF-C ASODN specially.

Non-thermal ablation of rabbit liver VX2 tumor by pulsed high intensity focused ultrasound with ultrasound contrast agent: Pathological characteristics.

AIM: To investigate the pathological characteristics of non-thermal damage induced by pulsed high intensity focused ultrasound (PHIFU) combined with ultrasound contrast agent (UCA), SonoVue (Bracco SpA, Milan, Italy) in rabbit liver VX2 tumor. METHODS: Liver VX2 tumor models were established in 20 rabbits, which were divided randomly into PHIFU combined with ultrasound contrast agent group (PHIFU + UCA group) and sham group. In the PHIFU + UCA group, 0.2 mL of SonoVue was injected intravenously into the tumor, followed by ultrasound exposure of I(SP) 5900 W/cm(2). The rabbits were sacrificed one day after ultrasound exposure. Specimens of the exposed tumor tissues were obtained and observed pathologically under light microscope and transmission electron microscope. The remaining tumor tissues were sent for 2,3,5-Triphenyltetrazolium chloride (TTC) staining. RESULTS: Before TTC staining, tumor tissues in both the sham and the PHIFU + UCA groups resembled gray fish meat. After TTC staining, the tumor tissues were uniformly stained red, with a clear boundary between tumor tissue and normal tissue. Histological examination showed signs of tumor cell injury in PHIFU + UCA group, with cytoplasmic vacuoles of various sizes, chromatin margination and karyopyknosis. Electron microscopic examination revealed tumor cell volume reduction, karyopyknosis, chromatin margination, intercellular space widening, the presence of high electron-density apoptotic bodies and vacuoles in cytoplasm. CONCLUSION: The non-thermal effects of PHIFU combined with UCA can be used to ablate rabbit liver VX2 tumors.

L-ascorbic acid metabolism in an ascorbate-rich kiwifruit (Actinidia. Eriantha Benth.) cv. 'White' during postharvest.

Kiwifruit (Actinidia eriantha Benth.) 'White', a novel cultivar with higher L-ascorbic acid (AsA) level, is registered in China. Changes in AsA, related metabolites, enzymatic activity, and gene expression associated with AsA biosynthesis and recycling process were investigated in this paper. The results indicated that AsA biosynthesis through L-galactose pathway supplemented by D-galacturonic acid pathway and AsA recycling collectively contributed to accumulating and remaining higher AsA level in kiwifruit cv. 'White' during postharvest. Moreover, L-galactose dehydrogenase (GalDH) activity and relative expressions of the genes encoding GDP-D-mannose pyrophosphorylase (GMP), L-galactose-1-P phosphatase (GPP), GDP-L-galactose phosphorylase (GGP), GalDH and D-galacturonate reductase (GalUR) were important for regulation of AsA biosynthesis, and the activity and expression of dehydroascorbate reductase (DHAR) were primarily responsible for regulation of AsA recycling in kiwifruit 'White' during postharvest.

Role of tRNA selenocysteine 1 associated protein 1 in the proliferation and apoptosis of cardiomyocyte­like H9c2 cells.

Transfer RNA selenocysteine 1 associated protein 1 (Trnau1ap) serves an essential role in the synthesis of selenoproteins, which have critical functions in numerous biological processes. Selenium deficiency results in a variety of diseases, including cardiac disease. However, the mechanisms underlying myocardial injury induced by selenium deficiency remain unclear. The present study examined the effects of Trnau1ap under­ and overexpression in cardiomyocyte­like H9c2 cells, by transfection with small interfering RNA and an overexpression plasmid, respectively. Expression levels of glutathione peroxidase, thioredoxin reductase and selenoprotein K were decreased in Trnau1ap­underexpressing cells, and increased in Trnau1ap­overexpressing cells. Using MTT, proliferating cell nuclear antigen, annexin V and caspase­3 activity assays, it was demonstrated that reducing Trnau1ap expression levels inhibited the proliferation of H9c2 cells and induced apoptosis. Conversely, increasing Trnau1ap expression levels promoted cell growth. Western blot analysis revealed that the phosphoinositide 3­kinase/protein kinase B signaling pathway was activated in Trnau1ap­underexpressing cells. Furthermore, the apoptotic pathway was activated in these cells, evidenced by relatively greater expression levels of B­cell lymphoma (Bcl­2)­associated X protein and reduced expression levels of Bcl­2. Taken together, these findings suggest that Trnau1ap serves a key role in the proliferation and apoptosis of H9c2 cells. The present study provides insight into the underlying mechanisms of myocardial injury induced by selenium deficiency.

[Surface plasmon resonance biosensor technology and its application in biomedicine].

Surface plasmon resonance (SPR) biosensors have become an advanced method for measuring biological molecular interaction. This article is focused on the principle and advantages of SPR biosensor chip technology, and its new applications in biomedical research fields. Its application prospects are also discussed.

[Design of a microfluidic immunoassay system based on superparamagnetic microbeads].

We use direct-write laser micromachining technology to fabricate the microfluidic chip, and to establish a microfluidic chemiluminescence immunoassay system based on superparamagnetic microbeads, for detecting alpha- fetoprotein (AFP). The AFP analysis can be completed in 20 minutes with 5 microl sample and 5 microl reagent, and there is a good linear correlation in the range of 1-800 ng/ml.

[The hardware design of a portable gastrointestinal wireless endoscope image receiver].

The portable gastrointestinal wireless endoscope image receiver is developed and based on TMS320C6211 DSP. It can receive and demodulate the modulated signal which is transmitted from the camera-capsule, and then output the video signal. The synchronizing signals offered by SAA7114H are made best of and are used to design the time logic circuit. The fitful video signal can be collected under the control of the time logic circuit. The circuit can automatically get rid of useless blank data and only collect effective and good-quality video signals, and storage them in CF card. In addition, the image signal can be processed and compressed by DSP, and thus the data storage space and the data- analyzing time can be saved.

[A comparison between the eye trackers of laser cornea correction systems made by foreign manufacturers].

Photo refractive keratectomy (PRK) and laser Situ Keratomileusis (LASIK) have been used for over a decade and become popular in China. Principles and characteristics of eye trackers made by several famous foreign manufacturers are introduced in this paper and their developing direction in the future is pointed out too.

[A simulation design of a one-way micro valve for the micro engineering capsule].

This paper proposes a one-way micro valve with a simple structure and a simulation design for the engineering capsule. We have now got its design parameter selection method and its mechanic characteristic from experiments.

[Latest progress of minimally-invasive medical systems in the field of alimentary tract diagnosis and treatment].

The capsule-style micro-system is a hot spot of minimally-invasive medical instruments. Progresses of some typical capsule-style micro-systems, such as the wireless endoscope, site specific delivery capsule (SSDC), alimentary tract sampling capsule, PH capsule, etc. are introduced here in detail. The research activities in China and the developing trend of capsule-style micro-systems are discussed too.

[Research on swallowable camera-capsules of gastrointestinal wireless endoscope].

The swallowable camera-capsule,described in the aper, 11 mm in diameter and 30 mm in length , contains a CMOS image sensor, an optical system, a battery, a light source, a transmitter, a antenna and so on. The CMOS image sensor and its driving circuit can be miniaturized with MEMS technology. Image signal can be transmitted by analog or digital way. Image signal can be wirelessly transmitted through serial data interface. Finally, the processing technics of the capsule's crust is introduced.

[A cost & benefit management system for investment equipments].

Being aimed at the management of investment equipments, the flow of data has been put forward and the two main modes of data calculating have been established by our relying on No.1 Network of Military Healthy. The real-time management has been realized by the system in regard to eguipments' contact, charges, payouts, interest, payment, forecast and decision-makiing. It has been steadily test-running for more than 10 months in our hospital, and data have been processed exactly and creditably.

Decoding brain responses to pixelized images in the primary visual cortex: implications for visual cortical prostheses.

Visual cortical prostheses have the potential to restore partial vision. Still limited by the low-resolution visual percepts provided by visual cortical prostheses, implant wearers can currently only "see" pixelized images, and how to obtain the specific brain responses to different pixelized images in the primary visual cortex (the implant area) is still unknown. We conducted a functional magnetic resonance imaging experiment on normal human participants to investigate the brain activation patterns in response to 18 different pixelized images. There were 100 voxels in the brain activation pattern that were selected from the primary visual cortex, and voxel size was 4 mm × 4 mm × 4 mm. Multi-voxel pattern analysis was used to test if these 18 different brain activation patterns were specific. We chose a Linear Support Vector Machine (LSVM) as the classifier in this study. The results showed that the classification accuracies of different brain activation patterns were significantly above chance level, which suggests that the classifier can successfully distinguish the brain activation patterns. Our results suggest that the specific brain activation patterns to different pixelized images can be obtained in the primary visual cortex using a 4 mm × 4 mm × 4 mm voxel size and a 100-voxel pattern.

[Synthesis and spectral characterization of a new molybdenum phosphate compound (NH3CH2CH2NH3)7H2[NaMo12O30(PO4)2(HPO4)5(H2PO4)].7H2O].

The paper reports a new molybdenum phosphate (NH3CH2CH2NH3)7H2[NaMo12O30(PO4)2(HPO4)5(H2PO4)].7H2O containing Mo(V) which is hydrothermally synthesized and spectrally characterized by FTIR, Raman and UV/Vis DRS. The result indicates long Mo(V)-O bonds and innumerable hydrogen bonds in compound cause the red shift of characteristic vibrations in IR spectrum of title compound.

[Development of the chip system for measurement of red blood cell rheology].

We have developed a novel silicon microchannel system for the research of the red blood cell rheology and deformation. Recurring to many kinds of information technologies and advanced test means such as the electronic microscope, the image acquisition system and the computer processing system and by using the up-to-date Micro Electro Mechanical System (MEMS) technology, a new measuring system of red bood cell deformation is designed based on the chip and a model using the silicon microchannel to simulate capillary vessel network. It provides a real-time collection and anaysis of data which include image, speed, flow parameter, and so on. It provides printing, storage of the analysis results and patients' database management.