Visualizing polarization singularities in Bessel-Poincaré beams

We demonstrate that an annulus of light whose polarization is linear at each point, but the plane of polarization gradually rotates by π radians can be used to generate Bessel-Poincaré beams. In any transverse plane this beam exhibits concentric rings of polarization singularities in the form of L-lines, where the polarization is purely linear. Although the L-lines are invisible in terms of light intensity variations, we present a simple way to visualize them as dark rings around a sharp peak of intensity in the beam center. To do this we use a segmented polarizer whose transmission axes are oriented differently in each segment. The radius of the first L-line is always smaller than the radius of the central disk of the zero-order Bessel beam that would be produced if the annulus were homogeneously polarized and had no phase circulation along it.

Protective effect of Schisandrae chinensis oil on pancreatic β-cells in diabetic rats

Islet cell dysfunction in type 2 diabetes is primarily attributed to increased apoptosis of pancreatic β-Cells. The aim of the present study was to investigate the effects of Schisandrae chinensis oil on pancreatic β-Cells in type 2 diabetes mellitus rats and the associated molecular mechanisms of action. Wistar rats were randomly divided into diabetic rats and control rats, diabetic rats treated with Schisandrae chinensis oil (1 mg/kg), and control rats treated with Schisandrae chinensis oil. The serum fasting blood glucose, insulin, total cholesterol, and triglyceride levels along with MDA content, SOD and CAT activities in pancreatic tissues were measured. TUNEL was used to observe the apoptosis of rat pancreatic cells. Western blot was used to determine specific protein expression. The results showed that the oil significantly decreased fasting blood glucose, total cholesterol, triglyceride levels as well as the pancreatic MDA, but increased SOD and CAT activities. The protein expression of Bcl-2, PDX-1, GLUT-2, and GCK but not caspase 3 was significantly enhanced in the oil-treated rats compared with diabetic rats. However, Bax content was not significantly different between the control and DM groups. Schisandra chinensis oil improves pancreatic β-cell function by enhancing antioxidant potential of the pancreas, upregulating the expression of anti-apoptotic genes, increasing expression of glucose metabolism, and delaying islet cell apoptosis.

Study on the diagnosis of rabbit VX2 esophageal cancer and stent-therapy efficacy based on multiphoton microscopy

Histopathology is the gold standard for diagnosis of esophageal carcinoma. Based on two photon excited fluorescence (TPEF) and second harmonic generation (SHG), multiphoton microscopy (MPM) has become a novel optical tool adjunct to current histopathological techniques without any exogenous contrast agents. We thus investigated the potential of using TPEF and SHG techniques for differentiating cancer tissues from cancer tissues after paclitaxel-eluting stent implantation and normal esophageal tissues which are fresh and unstained without dying from the VX2 esophageal carcinoma rabbit models. Comparisons were made between MPM imaging and gold standard sections for each specimen stained with hematoxylin-eosin (H&E). Our results indicated that the MPM imaging technique could identify and distinguish among normal esophageal tissues, cancer tissues, as well as cancer tissues after stent implantation. Therefore, MPM potentially offers a powerful tool to not only diagnose esophageal cancer but also monitor stent-therapy efficacy.

Expression and significance of LRIG3 in human cervical squamous cell carcinoma

OBJECTIVE

To explore the effect of LRIG3 in the development of cervical squamous cell carcinoma.

MATERIALS AND METHODS

LRIG3 and epidermal growth factor receptor (EFGR) expressions were detected by immunohistochemistry. Western blot method was used to detect LRIG3 and EGFR protein expression at different time points. MTT, flow cytometry, and transwell chamber were adopted to examine the proliferation, apoptosis, and strength of invasion of Hela229 cell respectively.

RESULTS

During the process of normal cervix deteriorating into CIN and CSCC, LRIG3 expression gradually decreased, while EGFR increased. After the transfection of LRIG3 ASODN into cells, the amount of LRIG3 expression and the cell apoptosis rate both decreased gradually, EGFR protein expression and cell proliferation rate both increased (p < 0.05), other groups remained unchanged (p > 0.05). The cell migration ability in LRIG3 ASODN transfection group was stronger than that of other groups (p < 0.05).

CONCLUSION

LRIG3 plays an important role in Hela229 cell proliferation, apoptosis, and invasiveness.

Treatment with hydrogen sulfide alleviates streptozotocin-induced diabetic retinopathy in rats

BACKGROUND AND PURPOSE

Retinopathy, as a common complication of diabetes, is a leading cause of reduced visual acuity and acquired blindness in the adult population. The aim of present study was to investigate the therapeutic effect of hydrogen sulfide on streptozotocin (STZ)-induced diabetic retinopathy in rats.

EXPERIMENTAL APPROACH

Rats were injected with a single i.p. injection of STZ (60 mg·kg⁻¹) to induce diabetic retinopathy. Two weeks later, the rats were treated with NaHS (i.p. injection of 0.1 mL·kg⁻¹·d⁻¹ of 0.28 mol·L⁻¹ NaHS, a donor of H₂S) for 14 weeks.

KEY RESULTS

Treatment with H₂S had no significant effect on blood glucose in STZ-induced diabetic rats. Treatment with exogenous H₂S enhanced H₂S levels in both plasma and retinas of STZ-induced diabetic rats. Treatment with H₂S in STZ-treated rats improved the retinal neuronal dysfunction marked by enhanced amplitudes of b-waves and oscillatory potentials and expression of synaptophysin and brain-derived neurotrophic factor, alleviated retinal vascular abnormalities marked by reduced retinal vascular permeability and acellular capillary formation, decreased vitreous VEGF content, down-regulated expressions of HIF-1α and VEGFR2, and enhanced occludin expression, and attenuated retinal thickening and suppressed expression of extracellular matrix molecules including laminin β1 and collagen IVα3 expression in retinas of STZ-induced diabetic rats. Treatment with H₂S in retinas of STZ-induced diabetic rats abated oxidative stress, alleviated mitochondrial dysfunction, suppressed NF-κB activation and attenuated inflammation.

CONCLUSIONS AND IMPLICATIONS

Treatment with H₂S alleviates STZ-induced diabetic retinopathy in rats possibly through abating oxidative stress and suppressing inflammation.

Translucent Radiosity: Efficiently Combining Diffuse Inter-Reflection and Subsurface Scattering

It is hard to efficiently model the light transport in scenes with translucent objects for interactive applications. The inter-reflection between objects and their environments and the subsurface scattering through the materials intertwine to produce visual effects like color bleeding, light glows, and soft shading. Monte-Carlo based approaches have demonstrated impressive results but are computationally expensive, and faster approaches model either only inter-reflection or only subsurface scattering. In this paper, we present a simple analytic model that combines diffuse inter-reflection and isotropic subsurface scattering. Our approach extends the classical work in radiosity by including a subsurface scattering matrix that operates in conjunction with the traditional form factor matrix. This subsurface scattering matrix can be constructed using analytic, measurement-based or simulation-based models and can capture both homogeneous and heterogeneous translucencies. Using a fast iterative solution to radiosity, we demonstrate scene relighting and dynamically varying object translucencies at near interactive rates.