RESUMEN
In this study, we investigate the effects of deposition parameters (i.e. gas flow rates, bias voltages, and nozzle-to-substrate separation) on the microstructure of <100 nm thick gold deposits made with a room-temperature, atmospheric-pressure, ion-drag microsputterer. Without resorting to the use of vacuum or substrate heating, optimization of the printing process yields dense, continuous deposits (96.5% coverage) with low electrical resistivity (45 µΩ cm). Using statistical analysis, we developed a simple model that provides insight into the dynamics of such a printing method; based on this model, we identify electrostatic effects as the most important factor that influences the deposition process.
RESUMEN
The acute residual effect of whole body vibration (WBV) on upper extremity muscles and testosterone secretion was studied. Eight highly (G1), nine moderately trained gymnasts (G2) and seven physically active persons (CG) were recruited for the investigation. The intervention occurred in push-up position with the elbow flexed at 90°. G1 and G2 received 30 s, 30 Hz and 6 mm amplitude vibration repeated five times. Subjects were tested before and after one and ten minutes intervention in push-up movement. Contact time (Tc), fly time (Tf), TF/Tc ratio and impulse was measured from the ground reaction force-time curves recorded during self-selected (SSRM) and full range of motion (FRM). Testosterone level in urine was also determined. Tf increased significantly in SSRM for G1 and decreased in SSRM and FRM for G2. Tf/Tc ratio in FRM and impulse in SSRM increased significantly for G1 only. No significant alteration in testosterone level was observed. We concluded that WBV is a reasonable training modality for influencing dynamic work of upper extremity muscle, but the reaction to WBV is training and individual dependent. It seems that WBV do not influence dynamic work through increased testosterone secretion because of the relatively low mass of the involved muscles.
Asunto(s)
Brazo/fisiología , Ejercicio Físico/fisiología , Movimiento/fisiología , Músculo Esquelético/fisiología , Adulto , Humanos , Masculino , Testosterona/orina , VibraciónRESUMEN
This study investigated the effect of organic carbon source on ammonia oxidizing community in single sludge laboratory scale sequencing batch reactors (SBR). Two sequencing batch reactors performing simultaneous carbon oxidation and nitrification were operated. Operationally and functionally, these two reactors were identical, except that one reactor was fed peptone and sodium acetate, and the other was fed glucose and sodium acetate as external organic carbon sources. The peptone-fed reactor had 98.1 + or - 1.84% COD removal and 97.3 + or - 6.69% NH(3)-N oxidation. The glucose-fed reactor had 99.1 + or - 1.29% COD removal and 99.4 + or - 0.76% NH(3)-N oxidation. The reactor fed with peptone, a complex organic carbon source comprised of enzymatic digests of animal proteins, had greater diversity in both the heterotrophic bacterial community and the ammonia oxidizing bacteria community than in the reactor fed with glucose, a simple sugar as evidenced by automated ribosomal intergenic spacer analysis (ARISA) and terminal restriction fragment length polymorphism (TRFLP) experiments respectively.
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Bacterias/metabolismo , Carbono/metabolismo , Aguas del Alcantarillado/microbiología , Eliminación de Residuos Líquidos/métodos , Amoníaco/metabolismo , Reactores Biológicos/microbiología , Oxidación-ReducciónRESUMEN
UNLABELLED: This study compared two training regimens in which knee extensor exercises were performed at different range of motion. METHODS: Sixteen males performed bouts of 90 maximal isokinetic eccentric contractions over 6 consecutive days (B1-B6) at either small (n=8) or large (n=8) range of motion. Average of peak torque (Mp) of each of the 90 contraction trials were calculated, plasma creatine kinase (CK) and lactate dehydrogenase (LDH) activities were measured before, 24 h, 48 h and 6 d after B1. Muscle soreness was evaluated every day during the experiment. RESULTS: At B3 Mp reduced more in group L than in group S. From B1 to B6 group S increased Mp, while in group L Mp did not return to the baseline level. In both groups CK activity elevated 24 h following B1. CK activity was significantly higher in group L 6d after B1. In group L muscle soreness was higher at 48 h, 72 h, 4 d and 5 d after B1. CONCLUSION: High-intensity, consecutive eccentric knee extensor exercise training at large range of motion may induce greater development of muscle damage and force deficit, than training at small range of motion. Training at small range of motion may induce early adaptation in voluntary torque production.
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Ejercicio Físico , Articulación de la Rodilla/fisiopatología , Contracción Muscular , Enfermedades Musculares/fisiopatología , Dolor/fisiopatología , Músculo Cuádriceps/fisiopatología , Adaptación Fisiológica , Adolescente , Adulto , Biomarcadores/sangre , Fenómenos Biomecánicos , Creatina Quinasa/sangre , Humanos , L-Lactato Deshidrogenasa/sangre , Masculino , Enfermedades Musculares/etiología , Enfermedades Musculares/patología , Dolor/etiología , Dolor/patología , Músculo Cuádriceps/enzimología , Músculo Cuádriceps/patología , Rango del Movimiento Articular , Recuperación de la Función , Factores de Tiempo , Torque , Adulto JovenRESUMEN
The objective of this study was to determine whether creatine supplementation (CrS) could improve mechanical power output, and swimming performance in highly trained junior competitive fin swimmers. Sixteen male fin swimmers (age:15.9+/-1.6 years) were randomly and evenly assigned to either a creatine (CR, 4x5 g/day creatine monohydrate for 5 days) or placebo group (P, same dose of a dextrose-ascorbic acid placebo) in a double-blind research. Before and after CrS the average power output was determined by a Bosco-test and the swimming time was measured in two maximal 100 m fin swims. After five days of CrS the average power of one minute continuous rebound jumps increased by 20.2%. The lactate concentration was significantly less after 5 minutes restitution at the second measurement in both groups. The swimming time was significantly reduced in both first (pre: 50.69+/-1.41 s; post: 48.86+/-1.34 s) and second (pre: 50.39+/-1.38 s; post: 48.53+/-1.35 s) sessions of swimming in CR group, but remained almost unchanged in the P group.The results of this study indicate that five day Cr supplementation enhances the dynamic strength and may increase anaerobic metabolism in the lower extremity muscles, and improves performance in consecutive maximal swims in highly trained adolescent fin swimmers.
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Creatina/administración & dosificación , Suplementos Dietéticos , Fuerza Muscular/efectos de los fármacos , Músculo Esquelético/efectos de los fármacos , Resistencia Física/efectos de los fármacos , Natación , Administración Oral , Adolescente , Peso Corporal/efectos de los fármacos , Método Doble Ciego , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Ácido Láctico/sangre , Extremidad Inferior , Masculino , Músculo Esquelético/metabolismo , Análisis y Desempeño de Tareas , Factores de Tiempo , Adulto JovenRESUMEN
In animal models, unaccustomed eccentric exercise (EE) has been widely related to muscle fiber membrane (sarcolemma) damage. On the contrary, studies in humans reported that sarcolemma was not susceptible to damage following a single bout of EE. We hypothesized that the single bout of EE used by those studies was not sufficient to induce sarcolemma damage, in humans. In this study we examined muscle biopsies from untrained males who either performed six sets of 15 reps of maximum voluntary eccentric contractions (n=9), for six consecutive days, or served as control-group (n=6). Blood and biopsy samples were obtained one week prior to exercise, immediately after bout 3, and 24h after the last training session. In addition to standard haematoxylin-eosin staining, all biopsies were stained immunohistochemically using antibodies specific for fibronectin and desmin antigens. In the exercise-group, no biopsies taken at pre-exercise or post-exercise level showed evidence of sarcolemma damage as stained by anti-fibronectin antibody in eight of nine subjects. Serum creatine kinase (CK) and lactate dehydrogenase (LDH) activities increased significantly throughout the study despite the lack of sarcolemma damage.We suggest that in humans, repeated bouts of EE do not cause gross sarcolemma damage in the mid-belly of Vastus Lateralis.
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Ejercicio Físico/fisiología , Contracción Muscular/fisiología , Músculo Esquelético/fisiología , Sarcolema/fisiología , Adaptación Fisiológica , Adolescente , Adulto , Biomarcadores/metabolismo , Desmina/metabolismo , Fibronectinas/metabolismo , Humanos , Inmunohistoquímica , Masculino , Fuerza Muscular/fisiología , Adulto JovenRESUMEN
PURPOSE: Sprinting, bouncing, and spontaneous landings are associated with a forefoot contact whereas walking, running, and jumping are associated with heel-toe foot placement. Because such foot placement strategies influence landing mechanics or the ensuing performance, the purpose of this work was to compare lower extremity kinematics and kinetics and muscle activation patterns between drop vertical jumps performed with heel-toe (HTL) and forefoot (FFL) landings. METHODS: Ten healthy male university students performed two types of drop jump from a 0.4-m high box placed 1.0-m from the center of the force plate. They were instructed to either land first on the ball of the feet without the heels touching the ground during the subsequent vertical jump, i.e., forefoot landing jump (FFL), or to land on the heels followed by depression of the metatarsals, i.e., heel-toe landing jump (HTL). Three successfully performed trials per jump type were included in the analysis. The criteria for selection of the correct jumps was proper foot position at contact as judged from video records and the shape of force-time curve. RESULTS: The first peak and second peak determined from the vertical force-time curves were 3.4 times greater and 1.4 times lower for HTL compared with those with FFL (P<0.05). In the flexion phase of HTL, the hip and knee joints contributed 40% and 45% to the total torque, whereas during FFL the greatest torque contributions were 37% for both the knee and ankle joints. During the extension phase, the greatest torque contributions to the total torque were 41% and 45% by the knee and ankle joints during HTL and 34% and 55% during FFL. During the flexion phase, power production was 20% greater (P<0.05) in HTL than in FFL, whereas during the extension phase power production was 40% greater in FFL than in HTL. In the flexion phase of HTL the hip and knee joints produced the greatest power, and during the extension phase the knee and ankle joints produced the greatest power. In contrast, during both the flexion and extension phases of FFL, the knee and ankle joints produced the greatest power. The EMG activity of gluteus, vastus lateralis, and plantar flexor muscles was similar between HTL and FFL in most cases except for the greater vastus lateralis EMG activity during precontact phase in HTL than in FFL and the greater gastrocnemius activity in FFL than in HTL. CONCLUSION: Foot placement strategy modifies the individual joint contributions to the total power during drop jumping.
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Pie/fisiología , Postura/fisiología , Adulto , Fenómenos Biomecánicos , Electromiografía , Humanos , Masculino , Músculos/fisiologíaRESUMEN
In the period 1976-1990 a total of 282 chronic uraemic patients were put to peritoneal dialysis by means of abdominally implanted Tenckhoff catheters, out of which 170 had to be replaced. Description of the catheter types is followed by a summary of the rules of surgical implantation and postoperative treatment that should be observed for the peritoneal dialysis to be effective. Discussed are the causes and percentage distribution of changes that call for catheter replacement, finally the alternatives of conservative therapy.
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Materiales Biocompatibles , Catéteres de Permanencia , Diálisis Peritoneal Ambulatoria Continua/métodos , Tereftalatos Polietilenos , Uremia/terapia , Abdomen , Enfermedad Crónica , HumanosRESUMEN
One chronic uraemic patient was treated with intermittent peritoneal dialysis. During the 9th month decreasing of ultrafiltration and increasing of the blood level of low-molecular weight substances was observed. Laparotomy was performed twice because of increased intraperitoneal bleeding. During the operation peritoneal thickening, intestinal adhesion and diffuse bleeding was noticed. The patient died because of ileus. The most probable cause of sclerosing peritonitis was due to the formalin solution, which was used for the disinfection of the Tenckhoff catheter. The causes and prevention of sclerosing peritonitis has been summarised.
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Diálisis Peritoneal/efectos adversos , Peritonitis/etiología , Enfermedades Renales Poliquísticas/terapia , Adulto , Cateterismo , Desinfectantes/efectos adversos , Formaldehído/efectos adversos , Humanos , Masculino , Peritonitis/patología , Esclerosis/inducido químicamenteRESUMEN
An uraemic patient under intermittent peritoneal dialysis was found in the 9th month of treatment to present ultrafiltration drop and increase of low-molecular weight substances. Two instances of laparotomy for heavy abdominal bleeding revealed peritoneal thickening, laminar intestinal concrescence and diffuse haemorrhage. The patient died in the 13th month of treatment under symptoms of ileus. Other reasons excluded, sclerosing peritonitis was attributed to the formalin solution employed as disinfectant for the abdominal catheter. The causative factors are listed together with the chances of prevention.
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Obstrucción Intestinal/etiología , Diálisis Peritoneal/efectos adversos , Peritonitis/etiología , Desinfectantes/efectos adversos , Humanos , Masculino , Persona de Mediana Edad , Peritonitis/patología , Esclerosis , Uremia/terapiaRESUMEN
Corpus adiposum buccae (c.a.b.) was studied on 42 human subjects (fetuses and adults) using microdissection under magnifying glass after injection of the great vessels of the head with plastics, transparency technique of Spalteholtz and current histological methods. In fetuses, c.a.b. appeared as a well-developed mass located between Buccinator and inferior border of the Masseter. In adults, it emanated three prolongations among which the anteriorly directed molar prolongation was more conspicuous in edentulous old people. Externally, it was covered by a fine conjunctival wrap, which sent septa dividing the buccal fat pad in a series of minute fibroadipous compartments. C.a.b. contained a rich vascular network deriving from the branches of the facial and maxillary arteries. In this vascular net a more developed artery emanated branches to the prolongations of the c.a.b. The veins were tributaries of the pterygoid venous plexus. Beside the vessels, c.a.b. contained also lymphatics and myelinated nerves. The authors postulated that c.a.b. assumed the following functions: a) It filled up the masseter-zygomaticus-buccinator space forming an amortizing and a slipping platform for the masticatory muscles in action; b) in the baby, it resisted to the negative pressure which acted into the buccal cavity during sucking; c) its rich venous net, provided with valve-like structures, may be implicated in the exo-endocranial blood flow by means of the pterygoid plexus.
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Tejido Adiposo/anatomía & histología , Tejido Adiposo/fisiología , Adulto , Anciano , Mejilla , Feto , Técnicas Histológicas , Humanos , Músculos Masticadores/anatomía & histología , Persona de Mediana EdadRESUMEN
For a total of 349 haemodialysis sessions in 35 patients, 50 special subclavian cannulations were performed. The catheters were implanted infraclavicularly by the Seldinger technique. The average duration of the cannulation period was 26.6 days and the number of dialysis sessions per catheter was 7. Aspects of subclavian cannulation together with indications and complications are described. In three chronically uraemic patients, after 1, 5, and 6 weeks of single-needle haemodialysis, it was noticed that the catheter tip (3-5 cm) inserted into the subclavian vein had broken off. The broken pieces, lodged in the segmental pulmonary arteries, never caused any complication during the observation periods as long as 6, 14 and 33 months. Therefore their removal, either open or transluminal, seemed unnecessary. To prevent complications of similar type it is advisable to avoid single-needle dialysis. Recommended instead is either the double-needle method or the use of a double-lumen catheter.
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Cateterismo Venoso Central/efectos adversos , Cuerpos Extraños/etiología , Arteria Pulmonar , Diálisis Renal , Vena Subclavia , Lesión Renal Aguda/terapia , Adulto , Catéteres de Permanencia/efectos adversos , Femenino , Humanos , Fallo Renal Crónico/terapia , Persona de Mediana EdadRESUMEN
Hemodialysis was performed in 349 cases on 35 patients with 50 special subclavian catheters. The catheters were inserted infraclavicularly with Seldinger's technique. The cannulation period was 26.6 (1-148) days and on the average 7 hemodialyses (1-63) were performed through 1 catheter. The aspects of subclavian catheterization, indication and complications are described. In 3 patients suffering from chronic uremia the end of the catheter (3-5 cm) in the subclavian vein was found broken after 1-5-6 weeks long "single-needle" dialysis. The broken end became fixed into the segmental artery of the lung and did not cause any complication during the long (6-14-33 months) observation period, thus its open or transluminal removal was not considered necessary. In the opinion of the authors the "single-needle" hemodialysis should be avoided to prevent similar complications. The use of the "two-needle" treatment or a catheter with double lumen is advisable.
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Cateterismo/efectos adversos , Fallo Renal Crónico/terapia , Diálisis Renal/instrumentación , Falla de Equipo , Migración de Cuerpo Extraño/etiología , Humanos , Enfermedades Pulmonares/diagnóstico por imagen , Enfermedades Pulmonares/etiología , Agujas , Radiografía , Diálisis Renal/efectos adversos , Vena SubclaviaRESUMEN
The sublobular artery arises from the arcuate artery, as a constant vessel possessing its proper personality, giving 2 equal subdivisions, from which part the interlobular arteries. The sublobular arteries are characterized by a particular origin and branching type, having no or sporadically disposed glomeruli. Occasionally, arteriae interlobulares derive directly from the arcuate artery too. The authors suggest the acception of term "Arteria sublobularis " in the international nomenclature of the renal vessels. According our opinion the canine kidney is composed of a number of conical units, containing in their axis a sublobular artery of 2nd order. Certain theoretical and practical aspects of this new conception are briefly discussed.
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Perros/anatomía & histología , Riñón/irrigación sanguínea , Arteria Renal/anatomía & histología , Animales , Arterias/anatomía & histología , Glomérulos Renales/irrigación sanguíneaRESUMEN
The pterygoid venous plexus (pt.v.pl.) was studied in 54 human heads (adults, children, fetuses) halved in the middle sagital plan, using microdissections and injections with PVC, coloured gelatin and roentgenopaque masses. In adults, the pt.v.pl. was closely related to the external pterygoid muscle. The superficial variant (more frequent) maintained connections with the facial vein through a venous network named by us "plexus pterygo-temporo-buccalis". The deep variant (less frequent) could be included in the system of venous plexuses placed at the basis cranii. Its tributaries, accompanying the lingual nerve, established connections with the veins of the sublingual compartment (a fact not yet mentioned in the literature). In children and old humans the pt.v.pl. was formed only by some large veins giving a radiate structure ("starfish-shaped" plexus) corresponding to the first and second portion of the maxillary artery. These results revealed that the pt.v.pl. is a unique formation which could be more developed laterally or medially in comparison with the external pterygoid muscle, in relation with the superficial or deep position of the maxillary artery. The practical importance of the pt.v.pl. is emphasized.