Picosecond Laser Shock Micro-Forming of Stainless Steel: Influence of High-Repetition Pulses on Thermal Effects

A study of the peen forming of thin stainless steel metal foils (50 μm thick) using a solid-state ps-pulsed laser, emitting at a wavelength of 1064 nm was conducted. The pitch distance between consecutive laser pulses was kept constant by tuning the laser repetition rate from 0.4 to 10 kHz, and subsequently the scanning speed. The induced bending angle and the radius of curvature were used to measure the effect of the treatment. Their dependence on the pulse energy, the treated area, the distance between lines, and the laser repetition rate was studied. High repetition rates do not allow the sample to cool down, affecting the bending to the point of being negligible. An FEM simulation and experiments were carried out to prove that the increase in temperature due to high repetition rate can relax the stresses induced by laser peen treatment, thus preventing bending in the sample.     

Role of Chrononutrition in the Antihypertensive Effects of Natural Bioactive Compounds

Hypertension (HTN) is one of the main cardiovascular risk factors and is considered a major public health problem. Numerous approaches have been developed to lower blood pressure (BP) in hypertensive patients, most of them involving pharmacological treatments. Within this context, natural bioactive compounds have emerged as a promising alternative to drugs in HTN prevention. This work reviews not only the mechanisms of BP regulation by these antihypertensive compounds, but also their efficacy depending on consumption time. Although a plethora of studies has investigated food-derived compounds, such as phenolic compounds or peptides and their impact on BP, only a few addressed the relevance of time consumption. However, it is known that BP and its main regulatory mechanisms show a 24-h oscillation. Moreover, evidence shows that phenolic compounds can interact with clock genes, which regulate the biological rhythm followed by many physiological processes. Therefore, further research might be carried out to completely elucidate the interactions along the time–nutrition–hypertension axis within the framework of chrononutrition.     

Acute Effects of Caffeine on Overall Performance in Basketball Players—A Systematic Review

Caffeine supplementation has become increasingly popular among athletes. The benefits of caffeine include delaying the negative effects of fatigue, maintaining a high level of physical and mental performance, and improving certain abilities necessary for sport success. Given the complex nature of basketball, caffeine could be a legal, ergogenic stimulant substance, which will positively affect overall basketball performance. The purpose of this systematic review was to summarize evidence for the effect of acute caffeine ingestion on variables related to the basketball performance. Web of Science, PubMed, Scopus and ProQuest, MEDLINE, and ERIC databases were searched up to February 2021. Studies that measured the acute effect of caffeine on basketball performance were included and analyzed. Eight studies published between 2000 and 2021 were included in the analysis. Pre-exercise caffeine intake increased vertical jump height, running time at 10 and 20 m without the ball, overall basketball performance (number of body impacts, number of free throws, rebounds, and assists) during simulated games, and reduced the time required to perform a basketball-specific agility test. Equivocal results between caffeine and placebo groups were found for aerobic capacity, free throw and three-point accuracy, and dribbling speed. Pre-exercise caffeine ingestion did not affect RPE, but insomnia and urinary excretion were increased. The pre-exercise ingestion of 3 and 6 mg/kg caffeine was found to be effective in increasing several physical performance variables in basketball players during sport-specific testing and simulated matches. However, considering the intermittent nature and complexity of basketball, and individual differences between players, future studies are needed.     

Treatment of aggressive fibromatosis: a retrospective study of 72 patients followed for 1-27 years

We evaluated prognostic factors for local recurrence-free survival, including expression of estrogen receptors, after surgical treatment of aggressive fibromatosis in 72 patients (53 women) having primary tumors between 1970 and 1998. Their median age at diagnosis was 31(1 month-77 years) years. 50 patients had extraabdominal and 22 abdominal fibromatosis. Median tumor size was 4 (1-27) cm. 8 patients were treated with an intralesional resection, 32 with marginal, 31 with wide and with radical resection. They were followed for a median of 8 (1-27) years. The overall and local recurrence-free 5-year survival rates were 98% and 73%, respectively. Univariate analysis identified age, compartmentalization and tumor size as prognostic factors for local recurrence-free survival as well as radiotherapy in extraabdominal tumors. In the multivariate analysis, tumor size > 4 cm, extracompartmental location, inadequate margin and age < 32 years were independent negative prognostic factors for local recurrence. None of the tumors expressed estrogen receptors. In conclusion, aggressive fibromatosis as a high local recurrence rate, but a good prognosis, since almost no patients die of their tumor.     

Enhancement of tendon-bone integration of anterior cruciate ligament grafts with bone morphogenetic protein-2 gene transfer: a histological and biomechanical study

BACKGROUND: The integration of tendon grafts used for replacement of the anterior cruciate ligament is still sometimes unsatisfactory and may be associated with postoperative anterior-posterior laxity. The goal of this study was to examine the capacity of bone morphogenetic protein-2 (BMP-2) gene transfer to improve the integration of semitendinosus tendon grafts at the tendon-bone interface after reconstruction of the anterior cruciate ligament in rabbits. METHODS: The anterior cruciate ligaments of adult New Zealand White rabbits were replaced with autologous double-bundle semitendinosus tendon grafts. The semitendinosus tendon grafts had been infected in vitro with adenovirus-luciferase, adenovirus-LacZ (AdLacZ), or adenovirus-BMP-2 (AdBMP-2); untreated grafts served as controls. The grafts were examined histologically at two, four, six, and eight weeks after surgery. In additional experiments, the structural properties of the femur-anterior cruciate ligament graft-tibia complexes, from animals killed eight weeks postoperatively, were determined from uniaxial tests. The stiffness (N/mm) and ultimate load to failure (N) were determined from the resulting load-elongation curves. RESULTS: Genetically engineered semitendinosus tendon grafts expressed reporter genes as well as BMP-2 in vitro. The AdLacZ-infected grafts showed two different histological patterns of transduction. Intra-articularly, infected cells were mostly aligned along the surface, and they decreased in number between two and eight weeks after surgery. In the intra-tunnel portions of the grafts, the number of infected cells did not decrease during the observation period. Moreover, a high number of transduced cells was found in the deeper layers of the tendons. In the control group, granulation-type tissue at the tendon-bone interface showed progressive reorganization into a dense connective tissue, and a later establishment of fibers resembling Sharpey fibers. In the specimens with an AdBMP-2-infected anterior cruciate ligament graft, a broad zone of newly formed matrix resembling chondro-osteoid had formed at the tendon-bone interface at four weeks after surgery. This area was increased at six weeks, showing a transition from bone to mineralized cartilage and nonmineralized fibrocartilage. In addition, in the AdBMP-2-treated specimens, the tendon-bone interface in the osseous tunnel was similar to that of a normal anterior cruciate ligament insertion. The stiffness (29.0 +/- 7.1 N/mm compared with 16.7 +/- 8.3 N/mm) and the ultimate load to failure (108.8 +/- 50.8 N compared with 45.0 +/- 18.0 N) were significantly enhanced in the specimens with an AdBMP-2-transduced graft when compared with the control values (p < 0.05). CONCLUSION: This study demonstrates that BMP-2 gene transfer significantly improves the integration of semitendinosus tendon grafts in bone tunnels after reconstruction of the anterior cruciate ligament in rabbits. Clinical Relevance: Novel technologies including gene therapy and tissue engineering, such as those described in this study, may provide useful therapeutic procedures to enhance biological healing after reconstruction of the anterior cruciate ligament.     

Clinical outcome at ten years after laparoscopic fundoplication: Nissen versus Toupet

Laparoscopic surgery has become the elective approach for the surgical treatment of gastroesophageal reflux disease in the last decade. Outcome data beyond 10 years are available for open fundoplication, with good-to-excellent results, but few studies report long-term follow-up after laparoscopic fundoplication. We performed a retrospective study of all the patients that underwent laparoscopic Nissen and Toupet fundoplications as antireflux surgery between 1995 and 1998 in our institution. To evaluate the long-term results, a face-to-face interview was performed in 2009. One hundred and six patients were included in the study. Surgical techniques performed were Nissen fundoplication (NF) in 56 patients and Toupet (TF) in 50. Complication rate was 4 per cent in both groups (nonsignificant [NS]). Two patients (4%) of NF required reoperation because of dysphagia. After 10 years, 10 per cent of the patients remain symptomatic in both groups. Fifteen per cent of NF take daily inhibitors of the proton pump versus 14 per cent of TF (NS). Twenty per cent of NF refer dysphagia, all of them without evidence of stenosis at endoscopy or contrasted studies. The satisfaction rate of the patients was 96 per cent in NF and 98 per cent in TF. Laparoscopic Toupet fundoplication seems to be as safe and long-term effective as Nissen, but with a lower incidence of postoperative dysphagia. In our experience Toupet fundoplication should be the elective approach for the surgical treatment of gastroesophageal reflux disease.