ASSESSMENT OF THE CONDITION OF PINE PLANTATIONS ALONG URBAN ROADS OF VORONEZH CITY

We have studied the state of pine phytocenoses in the city of Voronezh, along highways with different traffic intensities. A general degradation in the state of forest stands, a decrease in productivity, damage to radial growth were established. At a distance of 25-30 m from the highways, there is a decrease in the density and stock of forest stands at both sites, due to a decrease in lateral illumination, while the intensity of pollution decreases slightly. At a distance of 185-195 m from the highway at both sites, the height and growing stock reach their maximum values. Density and average diameter vary in different directions due to the presence of a concomitant recreational impact at the ―Prigorodnoye lesnichestvo‖ facility.

Microspectrophotometry of Wood Grain and Color

A reflecting microscope spectrophotometer was used for the colorimetry of wood using CIE (Commission Internationale de l’Éclairage) chromaticity coordinates. A microscope scanning stage and scanning with optical fibers were used to detect grain patterns. Ten exotic woods with a fine grain structure were tested because they are highly valued in the manufacture of musical instruments and furniture, and they had a wide range in color and grain structure. With lateral illumination (45°) of samples and a large measuring aperture, the results were comparable to those that might be obtained with a commercial colorimeter detecting diffuse Lambertian reflectance. With vertical illumination and coaxial photometry in a microscope, Fresnel reflectance was dominant. The best predictor of CIE x with lateral illumination was reflectance at 400 nm (r = - 0.916, P < 0.0005) and the relationship persisted with vertical illumination (r = -0.67, P < 0.025). Scanning across woods at 520 nm with a microscope scanning stage, there were relationships of CIE x with scanning peak height (r = 0.75 P < 0.01). In scanning across 6 cm of wood with optical fibers, there was a relationship of the number of reflectance peaks (from wood grain between dark lines) with peak width (r = - 0.89, P < 0.0005). Woods with a fine grain had numerous small peaks while woods with a coarse grain had a few wide peaks. Thus, there is a connection between the color and grain pattern of wood.

Multiangle Long-Axis Lateral Illumination Photoacoustic Imaging Using Linear Array Transducer

Photoacoustic imaging (PAI) combines optical contrast with ultrasound spatial resolution and can be obtained up to a depth of a few centimeters. Hand-held PAI systems using linear array usually operate in reflection mode using a dark-field illumination scheme, where the optical fiber output is attached to both sides of the elevation plane (short-axis) of the transducer. More recently, bright-field strategies where the optical illumination is coaxial with acoustic detection have been proposed to overcome some limitations of the standard dark-field approach. In this paper, a novel multiangle long-axis lateral illumination is proposed. Monte Carlo simulations were conducted to evaluate light delivery for three different illumination schemes: bright-field, standard dark-field, and long-axis lateral illumination. Long-axis lateral illumination showed remarkable improvement in light delivery for targets with a width smaller than the transducer lateral dimension. A prototype was developed to experimentally demonstrate the feasibility of the proposed approach. In this device, the fiber bundle terminal ends are attached to both sides of the transducer’s long-axis and the illumination angle of each fiber bundle can be independently controlled. The final PA image is obtained by the coherent sum of subframes acquired using different angles. The prototype was experimentally evaluated by taking images from a phantom, a mouse abdomen, forearm, and index finger of a volunteer. The system provided light delivery enhancement taking advantage of the geometry of the target, achieving sufficient signal-to-noise ratio at clinically relevant depths.

Phacoemulsification Outcomes with Different Illumination Techniques

Purpose To compare surgeon experience and the outcomes of phacoemulsification using 2 different illumination techniques for cataract extraction. Methods A prospective interventional case series was performed on 20 consecutive patients (20 eyes) with senile cataract who underwent phacoemulsification enhanced with a 23-G endoillumination probe. The main outcome measures were the surgeon's perception of depth of field and quality of visibility of intraocular structures, ease of performance of the surgical procedure, effectiveness, and complications related to the procedure. A surgeon-specific questionnaire was administered at the end of the procedure. Results Surgery was successfully performed in all patients without any complications. The surgeon indicated that lateral endoillumination markedly enhanced the details of the lens structures, mainly the posterior capsule visualization, better than the coaxial lighting with the surgical microscope. Lateral endoillumination created an enhanced 3D effect and improved the depth perception of lens intraoperatively. Conclusions The lateral illumination technique with a 23-G endoilluminator probe placed in the anterior chamber through a paracentesis creates an enhanced 3D effect and improves depth perception of lens during phacoemulsification. These benefits increase the safety of the procedure.