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A novel palladium-catalyzed stereoselective remote ­hydroamination reaction is disclosed. A series of azoles and skipped dienes undergo the migratory allylic C–H amination in good yields and selectivities. A desymmetric migratory azolation process is also developed to highlight the reliability of the transformation. Preliminary mechanistic experiments corroborate the designed metal walking and allylic substitution cascade strategy via Pd–H catalysis, different from prior ligand-to-ligand hydrogen transfer pathway for conjugated dienes.

With urbanization and economic development in China, medical needs in urban areas continue to increase, but the building of public hospitals is, however, restricted by available space. As a result, many hospitals have set up multiple campuses, with associated issues such as lack of experience in running a multicampus model, quality standardization, cost control, and culture conflicts. We have four campuses with successful operations. In this paper, we will share our management and operation experiences, which may provide some insights for other hospital managers.

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Additional file 1.

The intact expression of core clock genes is essential for organism homeostatic regulation and Clock (Clk) as one of drivers in core circadian gene plays a crucial role to maintain circadian rhythm...

In recent years, the coal mine intelligent development process has constantly advanced, putting forward higher requirements for monitoring mining equipment data. Sensor technology suitable for the special underground environment has also been developing. Hydraulic support is a key piece of equipment in fully mechanized coal mining. Monitoring the hydraulic support position and attitude has been an important part of coal mine intelligent development. In the present paper, a new oil cylinder displacement sensor was proposed. The oil cylinder translational motion was transformed into the magnet rotary motion via the motion conversion mechanism. The magnet angle was calculated by utilizing the single-chip microcomputer, and the oil cylinder expansion and contraction were calculated via the filtering algorithm. Results showed that the sensor accuracy could reach 0.5 mm. In recent years, the coal mine intelligent development process has constantly advanced, putting forward higher requirements for monitoring mining equipment data. Sensor technology suitable for the special underground environment has also been developing. Hydraulic support is a key piece of equipment in fully mechanized coal mining. Monitoring the hydraulic support position and attitude has been an important part of coal mine intelligent development. In the present paper, a new oil cylinder displacement sensor was proposed. The oil cylinder translational motion was transformed into the magnet rotary motion via the motion conversion mechanism. The magnet angle was calculated by utilizing the single-chip microcomputer, and the oil cylinder expansion and contraction were calculated via the filtering algorithm. Results showed that the sensor accuracy could reach 0.5 mm.

Additional file 1. Additional tables, figures and discussion.

Additional file 1. Table S1. Conservation scores for SARS-CoV-2 human protein-protein host interactome in Drosophila.

Additional file1: Table S1. The RNAi screen of endocytosis genes required for slit diaphragm protein endocytosis and recycling. Figure S1. The clathrin genes, Chc and Clc, are required for nephrocyte function. A MHC-ANF-RFP derived hemolymph ANF-RFP (red) uptake by nephrocytes. Hand-GFP labels both nephrocytes (big nucleus) and heart cells (small nucleus). Wild type (Control) flies accumulated abundant ANF-RFP. Subsequent panels show that Chc and Clc genes RNAi silencing severely reduced the ANF-RFP accumulation level. B Texas Red-labeled 10 kD Dextran particles uptake by nephrocytes. Particles were easily taken in and collected by wild type control nephrocytes in an ex vivo assay. Silencing of Chc and Clc genes clearly reduced levels of accumulated Dextran. C Quantification of relative ANF-RFP fluorescence in nephrocytes expressing the indicated gene silencing RNAi construct. D Quantification of relative Dextran-linked Texas Red fluorescence in nephrocytes expressing the indicated gene silencing RNAi construct. ***P

Impregnated diamond bits (IDB) are one of the main rotary drilling tools used for hard rock drilling. In the process of using IDB to drill, the friction and heat generation with the rock formation are important factors which will affect the drilling efficiency. These two factors may reduce the technical and economic indicators of drilling and cause “burning” accidents. In order to improve the drilling efficiency of the diamond bit, the bit structure was reasonably designed to ensure that the bit had a good cooling and chip removal ability during the drilling process. The bottom flow field and temperature field of IDB were investigated by combining numerical simulation with experimental study. The results showed that, for the IDB with 4 water ways, on the side of the water way with the same rotating direction of the bit, the velocity was faster, and the maximum velocity reached 23.65 m/s. At the contact surface between the bit and rock, the temperature reached the highest level of 210 ℃ and dropped rapidly from bottom to top until it was close to the temperature of the flushing fluid. The increase of the number of water ways led to a small flow rate of drilling fluid at a single water way, which reduced the heat conduction efficiency and resulted in poor cooling effect and serious bit wear.

For a multi-hop outdoor wireless sensor network (WSN), data gathering is full of challenges due to the unreliable wireless link and resource-limited nodes. In this paper, a sparse compressive sensing (CS) data gathering scheme based on directional random walk is proposed to resist the impact of packet loss on CS reconstruction accuracy and reduce the energy consumption. Nodes are unevenly deployed in the ring topology network. Data gathering is initiated by nodes located at the outermost ring with a certain probability and transmits forward along the directional walk paths until the CS-based data receiving buffer area is reached. A sparse measurement matrix is designed to collaborate with the CS projections. Additionally, we propose a random path selection scheme for the nodes visited by the projections to guarantee the reliable delivery of transmission and balanced energy consumption. Simulation results show that our proposed scheme can effectively resist the impact of packet loss on the CS reconstruction accuracy and significantly decrease the energy consumption compared to the existing schemes using the dense measurement projections and random walk projections.

The design and experimental demonstration of a large, ultrahigh-quality (Q) factor, and single-mode operation silicon ring resonator based on a strip silicon photonic waveguide are presented. The ring resonator comprises multimode straight strip waveguides (MMWG), single-mode strip waveguides (SMWG), 90° Bezier bends, and linear tapers. The SMWG are used in the coupling region to achieve mode coupling for the fundamental mode without exciting the higher-order mode. The MMWG, 1.6 μ m in width, are used to decrease the propagation loss. The taper smoothens the straight-to-bend transition and reduces the intermode crosstalk at the interface between the straight and bent waveguides. The design of the 90° Bezier bend ensures that only the maintained fundamental mode propagates at the bend with ultralow loss and low intermode interference. The resonator fabricated in this study had an ultrahigh-Q factor of 1.54 × 106, with a free spectrum range of 0.036 nm, and achieved an actual loss of unit transmission of approximately 0.25 dB/cm.

End-to-end speech recognition system is a major research field in speech recognition. The most typical model is the end-to-end speech recognition system based on CTC where RNN mining to and time sequence information are adopted, and a series of assumptions of HMM are discarded to obtain a good recognition rate. However, the CTC-based model is more dependent on the speech model and have a longer training cycle. Therefore, in the framework of traditional acoustic model, this paper proposes to train a feature extraction network of spectrogram based on attention mechanism by using prior knowledge. Firstly, it was spliced in the front end based on CTC model, and then the number of layers of cyclic neural network based on CTC model was reduced. Finally, it was combined to retrain. The experimental results show that the training time of the combined model is effectively reduced, and the accuracy of speech recognition is further improved.

High-Fat-Diet (HFD)-induced obesity is a major contributor to heart and mobility premature aging and mortality in both Drosophila and humans. The dSir2 genes are closely related to aging, but there are few directed reports showing that whether HFD could inhibit the expression dSir2 genes. Endurance exercise can prevent fat accumulation and reverse HFD-induced cardiac dysfunction. Endurance also delays age-relate functional decline. It is unclear whether lifetime endurance exercise can combat lifetime HFD-induced heart and mobility premature aging, and relieve the harmful HFD-induced influence on the dSir2 gene and lifespan yet. In this study, flies are fed a HFD and trained from when they are 1 week old until they are 5 weeks old. Then, triacylglycerol levels, climbing index, cardiac function, lifespan, and dSir2 mRNA expressions are measured. We show that endurance exercise improves climbing capacity, cardiac contraction, and dSir2 expression, and it reduces body and heart triacylglycerol levels, heart fibrillation, and mortality in both HFD and aging flies. So, lifelong endurance exercise delays HFD-induced accelerated age-related locomotor impairment, cardiac dysfunction, death, and dSir2 expression decline, and prevents HFD-induced premature aging in Drosophila.

The soybean pod borer, Leguminivora glycinivorella Matsumura (Lepidoptera: Tortricidae), is an economically significant soybean pest in northeastern Asia. Serine proteases are crucial enzymes responsible for protein digestion in herbivorous lepidopterans. In this study, a gene (Spbtry1) encoding a soybean pod borer serine protease was cloned from the organism's midgut. The Spbtry1 open reading frame encoded a 269 amino acid protein with a predicted molecular mass of approximately 29 kDa. Alignment of Spbtry1 with trypsins and chymotrypsins from other insects revealed a high degree of conservation in the putative catalytic domain region. Analysis by reverse transcriptase polymerase chain reaction indicated that Spbtry1 was specifically expressed in the midgut, its transcript existed constitutively in the larval stage, and its expression was highest in the 3rd instar larval stage. RNA interference indicated that Spbtry1 expression levels decreased on diets containing Spbtry1 double-stranded RNA (ds...

A rapid algorithm of multi-plane holographic display is given. A proper thin lens phase factor was combined with fast Fourier transform (FFT) in this algorithm to move the reconstructed image of Fourier transform hologram to specify depth from infinity and the imaging effect of this algorithm is identical with Fresnel diffraction. Using this simple operation replaced complicated Fresnel diffraction integral in the Ping-Pong iteration algorithm, the computational load of multi-plane hologram was reduced and computational speed was significantly increased. Moreover, the hologram of a 3-D object consists of two pictures at different depths was computed by this modified Ping-Pong algorithm. The reconstructing of this obtained hologram was also simulated in MATLAB. The result showed the new algorithm is feasible and effective.

Compared with infrared laser sources, the three-dimensional incoherent extended light source has the advantages of high power, wide spectral range, and low cost. It has extremely wide applications in high-precision and multi-component photoacoustic spectrometers. However, it encounters some problems about poor directivity, low energy density, irregular shape, light field shaping needed in the design of optical system. The photoacoustic spectrometer is required to collect and optimize the radiation of the centimeter-level three-dimensional extended light source to the whole space in a small volume. Through using a series of wavelength and frequency modulation elements, the final cylindrical light field distribution with millimeter-level radius and centimeter-level length is realized. According to the concept of optical expansion and the principle of edge light, this paper breaks through the traditional design mode based on point light source in the process of optical system design and optimization. The concept of extended light source is used throughout the design process. The luminous characteristics of the three-dimensional extended light source are directly acquired by the self-designed measurement method and device which is accurately reflected in the three-dimensional extended light source model in the form of micro-element. The design of the light field shaping system of the three-dimensional extended light source for the photoacoustic spectrometer is realized by the aspheric surface, and the relevant experimental verification is carried out. Taking the Hawkeye IR-Si272 light source for example, the experimental value of the light power at the entrance of the photoacoustic cell and the sidewall noise rate of the photoacoustic spectrometer have a small deviation from their corresponding simulation values. Compared with the original condenser system, the self-designed photoacoustic spectrometer light source system increases the value of the light power at the entrance of the photoacoustic cell from 0.86W to 1.32W, and reduces the value of the sidewall noise rate from 50.3% to 19.7%. The lower limit of detection of the concentration of trace gas in the order of ppm (parts per million) is also achieved.

To determine serum activities of angiotensin-converting enzyme (ACE) as a marker in diagnosis and determine the severity of Alzheimer's disease (AD), METHODS: We measured serum ACE activities in 59 moderate-severe AD, 19 mild AD, 45 amnestic mild cognitive impairment (aMCI) and 39 controls.We found that patients in moderate-severe AD stages showed significantly higher ACE in comparison to aMCI and controls (ANOVA, LSD post hoc test: p: 0.02 and p: 0.01, respectively). Logistic regression analysis showed that if ACE activities added 200 U/L, the superiority of AD risk was 1.18 times higher than before compared with the control group (OR 1.18, 95% CI 1.01-1.74; P=0.49). By means of multivariate linear regression analysis, we found that age (β coefficient: 7.77; P: 0.01) was significantly associated with ACE activities. However, ACE activities were found to be significantly negatively associated with measures of orientation and immediate recall among the AD patients (r0, P0.05), whereas ACE activities were not associated with any MMSE scores among the non-AD groups (P0.05).uuuu CONCLUSIONS: ACE serum activity that correlates with age is likely to constitute a potential risk factor for the development of AD. ACE serum activity might be a useful biomarker for disease status with increasingly high ACE from mild stage to moderate-severe stage. Moreover, patients with aMCI could take ACE inhibitor (ACEI) to decrease the incidence of AD, and patients with AD could take ACEI to retard cognitive decline in early AD.

It is well-known that the power allocation can enhance the power utilization of the distributed radar systems. We first analyze two interesting non-increasing properties of Cramer-Rao low bound (CRLB) for target location via distributed multiple radar systems. On the basis of the classical power allocation methods 15, this paper proposes a fast efficient power allocation algorithm applied to cognitive distributed multiple radar systems, which depends greatly on an alternating global search algorithm(AGSA). In this paper, our aim is directly to minimize the non-convex CRLB 15 of target location estimation. The convergence of the proposed algorithm is theoretically analyzed by LaSalle invariance principle. We analyze the computational complexity of the two closely-related algorithms. The famous Pareto optimal set associated with power allocation is obtained by the proposed algorithm, and it can indirectly derive the solution to problem for minimizing total power budget. Experimental results demonstrate that our algorithm has quick convergence and good performance.

For a prime number $p,$ let $\mathbb{Q}_p$ be the field of $p$-adic numbers. In this paper, we established the boundedness of a class of $p$-adic singular integral operators on the $p$-adic generalized Morrey spaces. The corresponding boundedness for the commutators generalized by the $p$-adic singular integral operators and $p$-adic Lipschitz functions or $p$-adic generalized Campanato functions is also considered.

In recent years, long-term continuous sea-ice datasets have been developed, and they cover the periods before and after the satellite era. How these datasets differ from one another before the satellite era, and whether one is more reliable than the other, is important but unclear because the sea-ice record before 1979 is sparse and not continuous. In this letter, two sets of sea-ice datasets are evaluated: one is the HadISST1 dataset from the Hadley Centre, and the other is the SIBT1850 (Gridded Monthly Sea Ice Extent and Concentration, from 1850 Onward) dataset from the National Snow and Ice Data Center (NSIDC). In view of its substantial importance for climate, the winter sea ice in the Barents and Kara seas (BKS) is of particular focus. A reconstructed BKS sea-ice extent (SIE) is developed using linear regression from the mean of observed surface air temperature at two adjacent islands, Novaya Zemlya and Franz Josef Land (proxy). One validation illustrates that the proxy is substantially coherent with the BKS sea-ice anomaly in the observations and the CMIP5 (phase 5 of the Coupled Model Intercomparison Project) historical experiments. This result indicates that the proxy is reasonable. Therefore, the establishment of the reconstructed BKS SIE is also reasonable. The evaluation results based on the proxy suggest that the sea-ice concentration prior to the satellite era in the NSIDC dataset is more realistic and reliable than that in the Hadley Centre dataset, and thus is more appropriate for use.

High-Fat-Diet (HFD)-induced obesity is a major contributor to heart and mobility premature aging and mortality in both Drosophila and humans. The dSir2 genes are closely related to aging, but there are few directed reports showing that whether HFD could inhibit the expression dSir2 genes. Endurance exercise can prevent fat accumulation and reverse HFD-induced cardiac dysfunction. Endurance also delays age-relate functional decline. It is unclear whether lifetime endurance exercise can combat lifetime HFD-induced heart and mobility premature aging, and relieve the harmful HFD-induced influence on the dSir2 gene and lifespan yet. In this study, flies are fed a HFD and trained from when they are 1 week old until they are 5 weeks old. Then, triacylglycerol levels, climbing index, cardiac function, lifespan, and dSir2 mRNA expressions are measured. We show that endurance exercise improves climbing capacity, cardiac contraction, and dSir2 expression, and it reduces body and heart triacylglycerol levels, heart fibrillation, and mortality in both HFD and aging flies. So, lifelong endurance exercise delays HFD-induced accelerated age-related locomotor impairment, cardiac dysfunction, death, and dSir2 expression decline, and prevents HFD-induced premature aging in Drosophila.

The level set method has many advantages for image segmentation, such as dealing with sharp corners, segmenting the boundaries of complex object and so on. However, it is easily affected by initial contour and control parameters. Fuzzy C-Means (FCM) clustering algorithm is one of the most popular methods of clustering analysis. Nevertheless, the traditional FCM clustering algorithm does not work well, because its initial centers are chosen randomly. In this paper, with the help of Genetic Algorithm (GA), we get the optimized cluster centers. For images, the resulting fuzzy clustering is used as the initial level set contour. At the same time, the results of fuzzy clustering can reduce the controlling parameters of level set method. The experiment results confirm its advantages for image segmentation.

In the lossy wireless sensor network (WSN), packets loss can severely degrade the performance of data gathering algorithm based on compressive sensing (CS). Due to the limited retransmission cannot ensure the high reliability of the wireless link, the CS data gathering algorithm based on retransmission and temporal sequence correlation prediction (CS-RTSC) is proposed in this paper. When packets loss occur in the process of data gathering, the limited retransmissions is the primary choice to recover the packets. If the recovery is not successful, the temporal sequence correlation prediction is adopted. Simulation results show that CS-RTSC algorithm can guarantee the normal implementation of the CS data gathering under the unreliable links compared to existing CS data gathering algorithm and the relative error of the data reconstruction under 30% packet loss ratio is only 0.1% higher than that under the ideal links.

miR-1 is a small noncoding RNA molecule that modulates gene expression in heart and skeletal muscle. Loss of Drosophila miR-1 produces defects in somatic muscle and embryonic heart development, which have been partly attributed to miR-1 directly targeting Delta to decrease Notch signaling. Here, we show that overexpression of miR-1 in the fly wing can paradoxically increase Notch activity independently of its effects on Delta. Analyses of potential miR-1 targets revealed that miR-1 directly regulates the 3'UTR of the E3 ubiquitin ligase Nedd4 Analysis of embryonic and adult fly heart revealed that the Nedd4 protein regulates heart development in Drosophila Larval fly hearts overexpressing miR-1 have profound defects in actin filament organization that are partially rescued by concurrent overexpression of Nedd4. These results indicate that miR-1 and Nedd4 act together in the formation and actin-dependent patterning of the fly heart. Importantly, we have found that the biochemical and genetic relationship between miR-1 and the mammalian ortholog Nedd4-like (Nedd4l) is evolutionarily conserved in the mammalian heart, potentially indicating a role for Nedd4L in mammalian postnatal maturation. Thus, miR-1-mediated regulation of Nedd4/Nedd4L expression may serve to broadly modulate the trafficking or degradation of Nedd4/Nedd4L substrates in the heart.

An algorithm for calculating a phase-only computer-generated hologram (CGH) for 3D color display using single chip liquid crystal on silicon (LCOS) is proposed. As an evolution of the G-S iteration, the proposed algorithm was obtained by replacing the Fresnel diffraction of single wavelength in the G-S algorithm with a color Fresnel diffraction process. Moreover, combined with "Ping-Pong" iteration, this algorithm was used to calculate 3D color holograms. Finally, a hologram that is capable of projecting a color 3D image was generated. Numerical simulation was performed, and an optical reconstruction system based on single spatial light modulation (SLM) was built to prove this method. Both numerical and optical reconstruction results indicated that the proposed method realized 3D color holographic display using single chip LCOS.

Through-wall radar detection technology is mainly oriented to targets moving at a speed of up to 3 m/s, where, the Doppler frequency shift resulting from the moving of the target usually falls within 20 Hz, and due to existence of walls and other barriers, the electromagnetic energy can be absorbed by the radar only after two-way attenuation in penetration of walls. Therefore, the echo features low energy and frequency. Due to presence of direct waves, there is a strong interference to the radar in DC fields. How to accurately extract and detect target echo in the presence of strong interference is the key to the project. This paper mainly introduces the composition of radar echo signals modulated by human movements (including movement of body, breathing, heartbeat, and other vital signs), proposes an algorithm for extraction of radar life signals based on multi-characteristic models according to the time-domain and frequency-domain difference between the target echo and interference noise, and verifies the effectiveness of the algorithm through tests on the sample machine.

(n+n) structure semiconductor gas sensor based on the compensation-feedback principle is composed of two sensitive materials A and B which are all n-type materials. The results analyzed from a theoretical viewpoint show that the (n+n) combined structure semiconductor gas sensor has higher selectivity, better thermal stability and higher sensitivity than conventional sensors when the materials A and B satisfied certain conditions. Though testing the characteristics of the (n+n) combined structure semiconductor gas sensor, the perfect (n+n) combined structure acetone gas sensor is fabricated, and could be applied to monitor and control leakage of acetone gas.

Metal matrix-impregnated diamond composites are widely used for fabricating diamond tools. In order to meet the actual engineering challenges, researchers have made many efforts to seek effective methods to enhance the performance of conventional metal matrices. In this work, tungsten carbide (WC) nanoparticles were introduced into WC-Bronze-Ni-Mn matrix with and without diamond grits for improving the performance of conventional impregnated diamond composites. The influence of WC nanoparticles on the microstructure, densification, hardness, bending strength and wear resistance of matrix and diamond composites were investigated. The results showed that the bending strength of matrix increased up to approximately 20% upon nano-WC addition, while densification and hardness fluctuate slightly. The grinding ratio of diamond composites increased significantly by about 100% due to nano-WC addition. The strengthening mechanism was proposed according to experimental results. The diamond composites with 2.8 wt% nano-WC addition exhibited the best overall properties, thus having potential to apply to further diamond tools.

The research indicates that in comparison with other solvents, such as ethanol, propanol, butyl alcohol and acetone, which are usually selected as the solvent in phenolic solution, methanol can increase curing rate and enhance crosslinking density of phenolic resins. Therefore, the chain conformations of resole dissolved in different solvents are investigated by using viscosity method. It shows that the chain conformation of resoles changes from loose coil to compact ball, as the strength of hydrogen bond between resole and solvent drops along with the decrease of polarity of solvents. The transition of the chain conformation causes the decrease of reaction probability and reaction rate between functional groups of resoles. The number of unreacted molecules increases, and the crosslinking density of cured resins decreases. The differential scanning calorimetric analysis shows that compared with the resins in methanol, ethanol, propanol, and butyl alcohol, exothermic peak of resole in acetone is obviously wider, and its peak exothermic temperature is lower. Both optical microscope pictures and atomic force microscope pictures demonstrate that the crosslinking density of resins in methanol is higher than those in other solvents. The research concludes that the type of solvent has a great influence on the curing rate and curing degree of resoles. © 2008 Wiley Periodicals, Inc. JAppl Polym Sci, 2008

Platelet derived-endothelial cell growth factor (PD-ECGF) is a highly potent angiogenic factor. Although angiogenesis plays an active role in pathophysiology of stroke, the expression pattern of this molecule in ischemic brain has not been investigated. In the present study, therefore, we investigated the change of PD-ECGF expression in the brain after ischemia.Using male Wistar rats, the right middle cerebral artery was occluded by a nylon thread for 90 minutes. The animals were decapitated 3 hours, 1, 4 and 10 days after the reperfusion, and frozen sections were prepared. We then performed immunohistochemistry for PD-ECGF and identified the cell phenotype which strongly expressed it by fluorescent double staining.In the sham-operated brain, only small numbers of cells slightly expressed PD-ECGF. The number of positively stained cells increased at the peri-ischemic area from hour 3 of reperfusion. Not only small-sized cells but also large-sized cells became stained. The number of stained cells further increased, and peaked at day 4 for large-sized cells and at day 10 as to small-sized cells. Fluorescent double staining revealed that both large-sized and small-sized cells were neurons, indicating that neurons are the main source of PD-ECGF production in the ischemic brain.PD-ECGF has a strong angiogenic property without vascular permeability increasing effect. This molecule may have a therapeutic potential for ischemic stroke treatment.

In the brain after infarction or trauma, the tissue eventually becomes pannecrotic and forms a cavity. In such situations, a scaffold is necessary for the implanted or migrated cells to produce new tissue. In this present study, therefore, we attempted to restore brain tissue using a novel biomaterial, polydimethylsiloxane-tetraethoxysilane (PDMS-TEOS) hybrid with or without vascular endothelial growth factor (VEGF), which is crucial for new vessel formation. When PDMS-TEOS scaffold was implanted into the artificial brain defect, it remained at the implanted site and kept the integrity of the brain shape. At 30 days after the implantation, the marginal territory of PDMS-TEOS scaffold became occupied by newly formed tissue. Immunohistochemical analysis revealed that the new tissue was constituted by astrocytes and endothelial cells. Addition of VEGF increased the newly produced tissue volume, and the immunohistochemical analysis showed that the numbers of astrocytes and endothelial cells were increased. Double staining with proliferation maker Ki67 demonstrated that VEGF significantly increased newly formed astrocytes and endothelial cells, indicating that addition of VEGF accelerated tissue restoration and angiogenesis. These findings show that implantation of PDMS-TEOS scaffold with VEGF might be effective for treating old brain infarction or trauma.

The criteria of polymer–polymer miscibility determined by dilute-solution viscometry are reviewed and this method was applied to study blend systems of rigid-rod (or semi-rigid) polymers and flexible polymer. The interactions of poly(benzazole) family (short as PBZs) with nylon 66 were investigated in methanesulfonic acid using dilute-solution viscometry (DSV) criteria and differential scanning calorimetry. Then the DSV data were analyzed by several different criteria reported previously to find out which criterion is more efficient and reasonable; moreover, the miscibility of the PBZs and nylon 66 was studied in detail. It was observed that PBO molecules have the strongest interaction force with nylon 66 molecules in the four blend systems presented in this paper.

Statin reduces cerebrovascular events independent of its cholesterol lowering effect. We hypothesized that statin inhibits early atherosclerotic change in common carotid artery (CCA), and investigated its effect on lectin-like oxidized-LDL receptor-1 (LOX-1) and monocyte chemoattractant protein-1 (MCP-1) expression, both of which are early atherosclerotic markers. Stroke-prone spontaneous hypertensive rats (SHR-SP) of 8 weeks old were orally treated with vehicle or simvastatin (20mg/kg) daily. After 4 weeks of simvastatin or vehicle treatment, or 2 weeks of vehicle and 2 weeks of simvastatin treatment, CCA was removed. LOX-1 and MCP-1 expression as well as macrophage infiltration were histologically investigated. Lipid deposition was also investigated by Sudan III staining. Simvastatin groups showed significantly smaller amount of lipid deposition and LOX-1 and MCP-1 expression, independent of serum lipid levels. Macrophage infiltration was also decreased. Reduction of cerebrovascular events by statins may be brought by the direct inhibition of atherosclerotic change.

Biliverdin (BV), one of the byproducts of heme catalysis through heme oxygenase (HO) system, is a scavenger of reactive oxygen species (ROS). We hypothesized that BV treatment could protect rat brain cells from oxidative injuries via its anti-oxidant efficacies. Cerebral infarction was induced by transient middle cerebral artery occlusion (tMCAO) for 90 min, followed by reperfusion. BV or vehicle was administered intraperitoneally immediately after reperfusion. The size of the cerebral infarction 2 days after tMCAO was evaluated by 2,3,5-triphenyltetrazolium chloride (TTC) stain. Superoxide generation 4 h after tMCAO was determined by detection of oxidized hydroethidine. In addition, the oxidative impairment of neurons were immunohistochemically assessed by stain for lipid peroxidation with 4-hydroxy-2-nonenal (4-HNE) and damaged DNA with 8-hydroxy-2'-deoxyguanosine (8-OHdG). BV treatment significantly reduced infarct volume of the cerebral cortices associated with less superoxide production and decreased oxidative injuries of brain cells. The present study demonstrated that treatment with BV ameliorated the oxidative injuries on neurons and decreased brain infarct size in rat tMCAO model.

Background: Cerebral ischemia is a major leading cause of death and at the first place cause of disability all over the world. There are a lot of drugs that are in experimental stage for treatment of stroke. Among them are calcium channel blockers (CCBs) that have, in animal models, different effectiveness in healing of ischemic damage in brain. Mechanism of CCBs' action in cerebral ischemia is still unclear, but antioxidative property is supposed to be implicated. In the present study, we investigated antioxidative and neuroprotective properties of two CCBs, azelnidipine and amlodipine. Methods: Male Wistar Kyoto rats were subjected to 90 min of transient middle cerebral artery occlusion (MCAO) by a nylon thread. Animals were divided into 3 groups, vehicle, azelnidipine and amlodipine group. In the azelnidipine and amlodipine groups, rats were treated with azelnidipine (1 mg/kg) and amlodipine (1 mg/kg) by gastric gavage for 2 weeks before MCAO. Vehicle group was treated by solution of methyl cellulose for 2 weeks. Rats were killed 24 h after MCAO. Physiological parameters (mean arterial pressure, heart rate, body weight), infarct volume, brain edema index, cerebral blood flow (CBF), oxidative stress markers which are HEL, 4-HNE, AGE and 8-OHdG, and evidence of apoptosis by TUNEL, were investigated. Results: There were no significant differences among groups in mean arterial pressure, heart rate and body weight. Treatment with azelnidipine and amlodipine reduced infarct volume and brain edema. Azelnidipine treated group showed more marked reduction of infarct volume and cerebral edema than amlodipine group. There was no attenuation of CBF in CCBs groups. The number of HEL, 4-HNE, AGE and 8-OHdG positive cells were significantly decreased in the CCBs treated groups. These molecules were again fewer in the azelnidipine group than in the amlodipine group. In TUNEL staining, the numbers of positive cells was smaller in the CCBs treated groups, especially in the azelnidipine group. Conclusions: Pretreatment of azelnidipine and amlodipine had a neuroprotective effect in ischemic brain. Antioxidative property is one of the important profiles of CCBs that is implicated in brain protection.

It is very important to investigate the mechanism of axonal growth in the ischemic brain in order to consider a novel mean of therapy for stroke. Netrins are chemotropic factors for axon with chemoattractant or chemorepellant guidance activities, and deleted in colorectal cancer (DCC) and neogenin are receptors for netrins. In this study, we examined expressions of netrin-1, DCC, and neogenin in the brain after 90 min of transient middle cerebral artery occlusion (tMCAO). Netrin-1 was expressed in neurons at the peri-ischemic area with a peak at 14 days. DCC was expressed both in neurons and astrocytic feet with a peak at 14 days, though neogenin was expressed in endothelial cells at MCA territory with a peak at the same time point. These results suggest that netrin-1 is involved in the promotion of axonal growth. The expression of netrin-1 and DCC was overlapped both in the spatial and temporal patterns, indicating that DCC plays a role in netrin-1's axonal growth promoting effects. The location of neogenin positive cells differed from that of netrin-1 positive cells, thus its angiogenic activity may not have relevance with netrin-1.

For brain tissue regeneration, any scaffold for migrated or transplanted stem cells with supportive angiogenesis is important once necrotic brain tissue has formed a cavity after injury such as cerebral ischemia. In this study, a new porous gelatin–siloxane hybrid derived from the integration of gelatin and 3-(glycidoxypropyl) trimethoxysilane was implanted as a three-dimensional scaffold into a defect of the cerebral cortex. The porous hybrid implanted into the lesion remained at the same site for 60 days, kept integrity of the brain shape, and attached well to the surrounding brain tissues. Marginal cavities of the scaffolds were occupied by newly formed tissue in the brain, where newly produced vascular endothelial, astroglial, and microglial cells were found with bromodeoxyuridine double positivity, and the numbers of those cells were dose-dependently increased with the addition of basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF). Extension of dendrites was also found from the surrounding cerebral cortex to the newly formed tissue, especially with the addition of bFGF and EGF. The present study showed that a new porous gelatin–siloxane hybrid had biocompatibility after implantation into a lesion of the central nervous system, and thus provided a potential scaffold for cell migration, angiogenesis and dendrite elongation with dose-dependent effects of additive bFGF and EGF.