An alternative asymmetric figure-of-eight single-layer suture technique for bowel anastomosis in an in vitro porcine model.

Anastomotic techniques are of vital importance in restoring gastrointestinal continuity after resection. An alternative asymmetric figure-of-eight single-layer suture anastomotic technique was introduced and its effects were evaluated in an in vitro porcine model. Twelve 15-cm grossly healthy small intestine segments from a porcine cadaver were harvested and randomly divided into asymmetric figure-of-eight single-layer suture (figure-of-eight suture) and single-layer interrupted suture technique (interrupted suture) groups (n = 6 in each group). The anastomosed bowel was infused with methylene blue solution to test anastomotic leakage. Anastomosis construction time, leakage, and suture material cost were recorded and analyzed statistically using Fisher's exact test and Student's t-test. One anastomotic leakage occurred (16.67%) in the figure-of-eight suture group, and two (33.33%) in the interrupted suture group (p > 0.9999). The anastomosis construction time was relatively short in the figure-of-eight suture group, but the difference did not reach a statistically significant level between the two groups. The mean number of suture knots and the cost of suture material in the figure-of-eight suture group were significantly decreased in comparison to the interrupted suture group (15.67 ± 3.30 vs. 22.17 ± 2.03, 167.11 ± 35.20 vs. 236.45 ± 21.70 CNY, p < 0.01, respectively). Our results suggested that the alternative asymmetric figure-of-eight suture technique was safe and economic for intestinal anastomosis. An in vivo experiment is required to elucidate the effects of this suture technique on the physiological anastomotic healing process.

Plasmonic fork-shaped hologram for vortex-beam generation and separation.

We introduce a multifunctional compact device that integrates a polarization beam splitter and an orbital angular momentum generator based on a plasmonic nano-aperture assisted detour phase meta-hologram. The proposed metasurface, which combines a phase singularity characterized fork hologram and polarization featured Λ-shaped antenna, achieves vortex generation and spin-based vortex splitting in transmission mode. Experimental demonstrations are launched under a linearly polarized incident beam, with polarization tomography as the analysis method. We expect this work to have applications in chip-level beam shaping and high-capacity communication.

Spin-orbital angular momentum tomography of a chiral plasmonic lens using leakage radiation microscopy.

Based on the spin-dependent directional coupling of surface plasmons (SPs) by ∧-shaped antennas, ring-shaped structures built with such antennas have potential applications for optical tweezers and optical switch technology. In this Letter, we introduce an optical method for realizing a complete polarization tomography of coupled SP fields by such a chiral-planar structure. We use a far-field optical approach, namely leakage radiation microscopy (LRM), to map the SPs propagation and polarization. Here, we fully analyze the polarization state of the generated SPs inside the vortex lens structure. In addition, we provide a theoretical model which agrees well with the experimental results.

SIRT1 activation inhibits hyperglycemia-induced apoptosis by reducing oxidative stress and mitochondrial dysfunction in human endothelial cells.

Sustained hyperglycemic stimulation of vascular cells is involved in the pathogenesis of diabetes mellitus­induced cardiovascular complications. Silent information regulator T1 (SIRT1), a mammalian sirtuin, has been previously recognized to protect endothelial cells against hyperglycemia­induced oxidative stress. In the present study, human umbilical vein endothelial cells (HUV­EC­C) were treated with D­glucose, and the levels of oxidative stress, mitochondrial dysfunction, the rate of apoptosis and SIRT1 activity were measured. The effect of manipulated SIRT1 activity on hyperglycemia­induced oxidative stress, mitochondrial dysfunction and apoptosis was then assessed using the SIRT1 activator, resveratrol (RSV), and the SIRT1 inhibitor, sirtinol. The present study confirmed that hyperglycemia promotes oxidative stress and mitochondrial dysfunction in HUV­EC­C cells. The accumulation of reactive oxygen species, the swelling of mitochondria, the ratio of adenosine 5'­diphosphate to adenosine 5'­triphosphate and localized mitochondrial superoxide levels were all increased following D­glucose treatment, whereas the mitochondrial membrane potential was significantly reduced by >50 mg/ml D­glucose treatment. In addition, hyperglycemia was confirmed to induce apoptosis in HUV­EC­C cells. Furthermore, the results confirmed the prevention and aggravation of hyperglycemia­induced apoptosis by RSV treatment and sirtinol treatment, via the amelioration and enhancement of oxidative stress and mitochondrial dysfunction in HUV­EC­C cells, respectively. In conclusion, the present study revealed that hyperglycemia promotes oxidative stress, mitochondrial dysfunction and apoptosis in HUV­EC­C cells, and manipulation of SIRT1 activity regulated hyperglycemia­induced mitochondrial dysfunction and apoptosis in HUV­EC­C cells. The data revealed the protective effect of SIRT1 against hyperglycemia­induced apoptosis via the alleviation of mitochondrial dysfunction and oxidative stress.

A novel model for calculating the inter-electrode capacitance of wedge-strip anode.

The wedge strip anode (WSA) detector has been widely used in particle detection. In this work, a novel model for calculating the inter-electrode capacitance of WSA was proposed on the basis of conformal transformations and the partial capacitance method. Based on the model, the inter-electrode capacitance within a period was calculated besides the total inter-electrode capacitance. As a result, the effects of the WSA design parameters on the inter-electrode capacitance are systematically analyzed. It is found that the inter-electrode capacitance monotonically increases with insulated gap and substrate permittivity but not with the period. In order to prove the validation of the model, two round WSAs were manufactured by employing the picosecond laser micro-machining technology. It is found that 9%-15% errors between the theoretical and experimental results can be obtained, which is better than that obtained by employing ANSYS software.

Noise analysis of the Vernier anode.

In this work, the partition noise and the electronic noise of the Vernier anode are thoroughly analyzed based on the theory of statistical variation and error analysis. A new method calculating the inter-electrode capacitance of the Vernier anode is proposed, and the electronic noise's effect is discussed in detail, which is useful for the optimal design of a Vernier anode in the induced charge mode. The calculated results of the inter-electrode capacitance for a 0.891 mm period Vernier anode are in good agreement with the measured results.

[Vernier Anode Design and Image Simulation].

Based-MCP position-sensitive anode photon-counting imaging detector is good at detecting extremely faint light, which includes micro-channel plate (MCP), position-sensitive anode and readout, and the performances of these detectors are mainly decided by the position-sensitive anode. As a charge division anode, Vernier anode using cyclically varying electrode areas which replaces the linearly varying electrodes of wedge-strip anode can get better resolution and greater electrode dynamic range. Simulation and design of the Vernier anode based on Vernier's decode principle are given here. Firstly, we introduce the decode and design principle of Vernier anode with nine electrodes in vector way, and get the design parameters which are the pitch, amplitude and the coarse wavelength of electrode. Secondly, we analyze the effect of every design parameters to the imaging of the detector. We simulate the electron cloud, the Vernier anode and the detector imaging using Labview software and get the relationship between the pitch and the coarse wavelength of the anode. Simultaneously, we get the corresponding electron cloud for the designing parameters. Based on the result of the simulation and the practical machining demand, a nine electrodes Vernier anode was designed and fabricated which has a pitch of 891 µm, insulation width of 25 µm, amplitude of 50 µm, coarse pixel numbers of 5.