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Wood quality results from the interaction between the genotype of trees and the silvicultural conditions to which they were subjected. Based on this interaction, research on the factors that add value to the woody raw material has an impact on the production of various forest products. This study aimed to evaluate the influence of different planting spacings (3×1, 3×2, 3×3 and 3×4 m) on the wood properties of three 4-year-old Eucalyptus clones. The wood of each clone was evaluated based on basic density, dry mass, anatomy, structural chemical composition, ash content and higher heating value. For at least one of the three clones studied, the planting spacing explained the variations in the basic density, dry mass, diameter and frequency of vessels and wall thickness of the wood fibers. Regardless of the eucalyptus clone, the area of vessels, the length and fraction of the fiber wall, as well as the contents of extractives, lignin, ash and the higher heating value of the wood were not influenced by the planting spacing. In summary, the change in the useful area alters the properties of wood in eucalyptus genetic materials in different ways and intensities at 4 years old.

Fluorescent proteins are used extensively in transgenic animal models to label and study specific cell and tissue types. Expression of these proteins can be imaged and analyzed using fluorescent and confocal microscopy. Conventional confocal microscopes cannot penetrate through tissue more than 4-6 μm thick. Tissue clearing procedures overcome this challenge by rendering thick specimens into translucent tissue. However, most tissue clearing techniques do not satisfactorily preserve expression of endogenous fluorophores. Using simple adjustments to the BABB (Benzoic Acid Benzyl Benzoate) clearing methodology, preservation of fluorophore expression can be maintained. Modified BABB tissue clearing is a reliable technique to clear skin and soft tissue specimens for the study of dermal biology, wound healing and fibrotic pathologies.

Objective: This study investigated the effects of low-level laser therapy (LLLT) and electrical stimulation (ES) on bone loss in spinal cord-injured rats., Materials and Methods: Thirty-seven male Wistar rats were divided into four groups: standard control group (CG); spinal cord-injured control (SC); spinal cord-injured treated with laser (SCL; GaAlAs, 830 nm, CW, 30 mW/cm, 250 J/cm(2)); and spinal cord-injured treated with electrical field stimulation (SCE; 1.5 MHz, 1:4 duty cycles, 30 mW, 20 min). Biomechanical, densitometric, and morphometric analyses were performed., Results: SC rats showed a significant decrease in bone mass, biomechanical properties, and morphometric parameters (versus CG). SCE rats showed significantly higher values of inner diameter and internal and external areas of tibia diaphyses; and the SCL group showed a trend toward the same result (versus SC). No increase was found in either mechanical or densitometric parameters., Conclusion: We conclude that the mentioned treatments were able to initiate a positive bone-tissue response, maybe through stimulation of osteoblasts, which was able to determine the observed morphometric modifications. However, the evoked tissue response could not determine either biomechanical or densitometric modifications.

Objective: This study aimed to compare the consequences of low-level laser therapy (LLLT) and low-intensity pulsed ultrasound (LIPUS) on bone repair., Background Data: Many studies have assessed the effects of LLLT and LIPUS on bone repair, but a comparison of them is rare., Methods: Male Wistar rats (n = 48) with tibial bone osteotomy were used. One group had the osteotomized limb treated with LLLT (GaAlAs laser, 780 nm, 30 mW, 112.5 J/cm(2)) and the second group with LIPUS (1.5 MHz, 30 mW/cm(2)), both for 12 sessions (five times per week); a third group was the control. After 20 days, rats were sacrificed and had their tibias submitted to a bending test or histomorphometric analysis., Results: In the bending test, maximum load at failure of LLLT group was significantly higher (p < 0.05). Bone histomorphometry revealed a significant increase in osteoblast number and surface, and osteoid volume in the LLLT group, and a significant increase in eroded and osteoclast surfaces in the LIPUS group., Conclusion: LIPUS enhanced bone repair by promoting bone resorption in the osteotomy area, while LLLT accelerated this process through bone formation.

We performed an endurance test on a textured diaphragm made of polyurethane (BioSpan, The Polymer Technology Group, San Francisco, CA, U.S.A.) to be used in the auxiliary total artificial heart (ATAH), an electromechanical device that can be totally implantable without removing the natural heart due to the device's reduced dimension. The objective of this endurance test was to predict whether this diaphragm would be capable of resisting in vivo tests with the ATAH implanted for fifteen days in calves. In this study, a mock loop system simulating the human circulatory system was used. The test protocol was elaborated to reproduce extreme physiological conditions. The technique to produce the textured diaphragms made of polyurethane is shown. The textured surface is used as basis to fix a layer of calf-skin gelatin. The technique used to make the diaphragm guaranteed a totally textured surface without cracking. The diaphragm demonstrated enough resistance to be used at the 15 day in vivo experiments.

Corrosion processes due to contact with the physiological environment should be avoided or minimized in orthopedic implants. Four metallic substrates frequently used as biomaterials: pure Ti, Ti-6Al-4V alloy, ASTM F138 stainless steel, and Co-Cr-Mo alloy, were coated with TiN using the physical vapor deposition (PVD) technique. These coatings have been screened by polarization curves in physiological solutions. TiN prepared by PVD is efficient as coating for stainless steel. On titanium and alloy there are no benefits concerning the corrosion resistance compared to the bare Ti-materials. TiN coatings have been screened according to ISO 10993 standard tests for biocompatibility and exhibited no cytotoxicity, dermal irritation, or acute systemic toxicity response.

"Observation Hip" is a provisional diagnosis. Although transient arthritis is the most frequent pathology, it is important to establish a diagnostic routine to consider the various types of hip pathology. Physical examination and clinical evolution are the most important factors in making a specific diagnosis.

A machine designed upon the principles of a crank lever mechanism was built to produce excessive use of the joints of small animals by means of continuous flexion-extension movements. Articular cartilage changes could be consistently produced after 5 to 10 days of exercise. Histochemical studies of the articular cartilage demonstrated a decrease in proteoglycan and an increase in acid phosphatase. These findings suggest that this animal model may be of value for the analysis of the earliest degenerative stages of the articular cartilage.

Measurements of stress and strain in parts of musculokeletal system has been extensively studied in recent years. "In vitro" tests have contributed important information. The present study is an attempt to assess "in vivo" measurements using electrical extensometers attached to the bone with biocompatible adhesives permitting accurate measurements of strain over long periods of time. Even though its seems to be an adequate method there are some limitations to be considered. The problem involving tissue reaction, protections and isolation of the measuring unit, validity of measurements and determination of the principal directions of the strain are discussed. When adequately used the method may contribute to the knowledge and understanding of biomechanics of the musculokeletal system.

Measurements of strain in live bone have been done through the use of the electrical strain gage method. For this purpose these transducers must be prepared to become electrically insulated, water proofing and biologically compatible. A technique which permit to use these devices in experimental animals as well as in human beings is described.