The effects of 12 weeks of functional strength training on muscle strength, volume and activity upon exposure to elevated Gz forces in high-performance aircraft personnel.

BACKGROUND: Technological advancements in modern military and acrobatic jet planes have resulted in extraordinary psychophysiological loads being exerted upon flying personnel, including inducing neck and back pain. The purpose of this study was to examine the effects of 12 weeks of functional strength training on 1) the volume and strength of the neck and shoulder muscles and 2) muscular activity upon exposure to helmets of different masses and elevated Gz forces in a long-arm centrifuge in high-performance aircraft personnel. METHODS: Eighteen participants underwent 12 weeks of functional strength training (n = 12) or the control protocol (n = 6) without additional strength training. Pre- and post-intervention tests included evaluations of isometric strength of the head extensor muscles, flexion, and lateral flexion and rotation, as well as magnetic resonance imaging (MRI) to measure the volume of the m. sternocleidomastoideus, m. trapezius, and deep neck muscles. Furthermore, during a long-arm centrifuge (+ 1.4 and + 3 Gz) protocol, the muscular activity levels of the m. sternocleidomastoideus, m. trapezius and m. erector spinae muscles were assessed without a flight helmet, with a helmet, and with a helmet and night vision goggles. Each participant's perception of muscular strain was noted immediately after the long-arm centrifuge protocol. RESULTS: The maximal isometric strength in all exercises and muscle volumes increased in the training group but not the control group (P < 0.05). Relative muscle activity (%MVC) with a helmet decreased after the intervention in the training but not the control group (P = 0.01). Relative muscle activity while wearing a helmet and night vision goggles was higher after intervention in the control group than in the training group (P < 0.01). The perceived muscular strain of the neck muscles induced by the long-arm centrifuge did not differ between the groups. CONCLUSION: Twelve weeks of functional strength training improves the maximal isometric strength and volume of neck and shoulder muscles and leads to lower relative muscle activation upon exposure to elevated Gz forces in a long-arm centrifuge.

Synthesis, crystal structure and cytotoxicity of new oxaliplatin analogues indicating that improvement of anticancer activity is still possible.

Oxaliplatin, (trans-R,R-cyclohexane-1,2-diamine)oxalatoplatinum(II), has recently been approved for combination chemotherapy of metastatic colorectal cancer. Oxaliplatin is significantly more active than its trans-S,S isomer and the mixture of both enantiomers. New oxaliplatin analogues, (SP-4-3)-(4-methyl-trans-cyclohexane-1,2-diamine)oxalatoplatinum(II) and (SP-4-3)-(4-ethyl-trans-cyclohexane-1,2-diamine)oxalatoplatinum(II), have been synthesized, and their cytotoxicity has been tested in comparison to oxaliplatin, its corresponding trans-S,S isomer, and the mixture of both enantiomers. In comparison to oxaliplatin, even the trans-R,R/trans-S,S mixture of the 4-methyl and 4-ethyl substituted oxaliplatin analogues have shown an equivalent cytotoxicity in ovarian cancer cells (CH1) and superior antiproliferative properties in colon cancer cells (SW480) in the case of a predominantly equatorial position of the substituent at position 4 of the trans-cyclohexane-1,2-diamine ligand, whereas an axial substitution results in decreased cytotoxic potency.