This study was designed to assess the efficacy and outcomes of argon plasma coagulation (APC) in ... more This study was designed to assess the efficacy and outcomes of argon plasma coagulation (APC) in the management of chronic radiation proctitis after conventionally fractionated, dose-escalated radiation therapy (≥7560 cGy). We retrospectively reviewed the charts on all patients treated with external beam radiation therapy (minimum dose, 7560 cGy) for histologically confirmed prostate cancer at our institution from 2003 to 2011. Five hundred patients met these criteria; of these, 35 patients (7.0%) developed radiation proctitis necessitating intervention with APC. Indications for APC treatment were either the need for blood transfusions resulting from proctitis-related anemia or refractory bleeding despite medical management. The median follow-up from the completion of radiation treatment was 78 months (range, 19-129) and the median follow up from the most recent APC treatment was 56 months (range, 3-112). Fifteen men (42.9%) needed blood transfusions because of proctitis-related ane...
Copper complexes of tertiary amine ligands have emerged as the catalysts of choice in the extensi... more Copper complexes of tertiary amine ligands have emerged as the catalysts of choice in the extensively employed atom transfer radical polymerization (ATRP) protocol. The halide ligand substitution reactions of five-coordinate copper(II) complexes of tris[2-(dimethylamino)ethyl]amine (Me6tren), one of the most active ATRP catalysts, has been studied in a range of organic solvents using stopped-flow techniques. The kinetic and activation parameters indicate that substitution reactions on [Cu(II)(Me6tren)X](+) (X(-) = Cl(-) and Br(-)) and [Cu(II)(Me6tren)(Solv)](2+) (Solv = MeCN, DMF, DMSO, MeOH, EtOH) are dissociatively activated; this behavior is independent of the solvent used. Adjusting the effective concentration of the solvent by addition of an olefinic monomer to the solution does not affect the kinetics of the halide binding (kon) but can alter the outer-sphere association equilibrium constant (KOS) between reactants prior to the formal ligand substitution. Halide (X(-)/Y(-)) ex...
Senescence-associated proteolysis in plants is a complex and controlled process, essential for mo... more Senescence-associated proteolysis in plants is a complex and controlled process, essential for mobilization of nutrients from old or stressed tissues, mainly leaves, to growing or sink organs. Protein breakdown in senescing leaves involves many plastidial and nuclear proteases, regulators, different subcellular locations and dynamic protein traffic to ensure the complete transformation of proteins of high molecular weight into transportable and useful hydrolysed products. Protease activities are strictly regulated by specific inhibitors and through the activation of zymogens to develop their proteolytic activity at the right place and at the proper time. All these events associated with senescence have deep effects on the relocation of nutrients and as a consequence, on grain quality and crop yield. Thus, it can be considered that nutrient recycling is the common destiny of two processes, plant senescence and, proteolysis. This review article covers the most recent findings about leaf senescence features mediated by abiotic and biotic stresses as well as the participants and steps required in this physiological process, paying special attention to C1A cysteine proteases, their specific inhibitors, known as cystatins, and their potential targets, particularly the chloroplastic proteins as source for nitrogen recycling.
Latin American Journal of Solids and Structures an Abcm Journal, Feb 7, 2015
ABSTRACT The analysis of cracked brittle mechanical components considering linear elastic fractur... more ABSTRACT The analysis of cracked brittle mechanical components considering linear elastic fracture mechanics is usually reduced to the evaluation of stress intensity factors (SIFs). The SIF calculation can be carried out experimentally, theoretically or numerically. Each methodology has its own advantages but the use of numerical methods has become very popular. Several schemes for numerical SIF calculations have been developed, the J-integral method being one of the most widely used because of its energy-like formulation. Additionally, some variations of the J-integral method, such as displacement-based methods, are also becoming popular due to their simplicity. In this work, a simple displacement-based scheme is proposed to calculate SIFs, and its performance is compared with contour integrals. These schemes are all implemented with the Boundary Element Method (BEM) in order to exploit its advantages in crack growth modelling. Some simple examples are solved with the BEM and the calculated SIF values are compared against available solutions, showing good agreement between the different schemes.
International Journal of Neuroscience, Sep 1, 1988
An attempt was made in two experiments to reinvestigate the effects of the antiandrogen cyprotero... more An attempt was made in two experiments to reinvestigate the effects of the antiandrogen cyproterone acetate (CA) on mouse social behavior in a variety of ethologically-assessed paired encounters. The data confirm that CA reduces offense (threat and attack) in animals when both subjects receive the material but that CA has no such action in other pairings. This suggests that CA's major suppressive effect on "hostility" is expressed in mice via a reduction in "attack-promoting" pheromone production. Indeed, there was evidence in the more chronic study that CA, could augment (via a central mechanism?) offense in subjects paired with docile anosmic opponents. Changes in defense were largely responses to variations in the degree of attack to which animals were subjected. The antihormone also had actions on other aspects of behavior including sexual activity, social investigation and immobility in such tests. CA had a potent suppressive action on the weights of sex accessory glands. The data do not suggest that CA can be used as a specific antihostility agent.
Recent studies suggest that motivations for certain forms of masculine behavior including social ... more Recent studies suggest that motivations for certain forms of masculine behavior including social aggression are mediated by central estrogen receptors. Two studies using antiestrogens in rodent species were performed. Intact male LH rats were given Tamoxifen or vehicle for 4 or 8 days. The three possible pairings were videotaped for 60 min. Intact male OF1 mice were given CI-680 or vehicle over 25 days. Similar pairings were carried out but some CI-680 or vehicle animals were paired with anosmic opponents. Encounters were videotaped for 10 min. In both experiments evidence was obtained that the antiestrogen markedly reduced time allocated to offense. Any variations in defense were a consequence of the level of attack to which animals were subjected. Neither compound greatly influenced the androgen-dependent sex accessory glands. Antiestrogens consequently have potential as antihostility agents in some forms of attack.
An efficient and general preparation of S-(alkoxycarbonyl)-O-alkyldithiocarbonates is described. ... more An efficient and general preparation of S-(alkoxycarbonyl)-O-alkyldithiocarbonates is described. The method is based on the reaction of potassium O-alkylmonothiocarbonates with O-alkylchlorothiocarbonates in acetone-water (9:1) at 0°C. The yields are 91–100%.
A detailed study under forward-bias conditions of the physical origin of high frequency noise in ... more A detailed study under forward-bias conditions of the physical origin of high frequency noise in p+(Si)-n (Si1-xGex) heterojunctions using ensemble Monte Carlo simulation is reported. Based on the internal magnitudes, we determine how the strained SiGe layer induces different features in the perpendicular transport of a heterojunction as compared with that of a silicon p+n homojunction. The main part of
This study was designed to assess the efficacy and outcomes of argon plasma coagulation (APC) in ... more This study was designed to assess the efficacy and outcomes of argon plasma coagulation (APC) in the management of chronic radiation proctitis after conventionally fractionated, dose-escalated radiation therapy (≥7560 cGy). We retrospectively reviewed the charts on all patients treated with external beam radiation therapy (minimum dose, 7560 cGy) for histologically confirmed prostate cancer at our institution from 2003 to 2011. Five hundred patients met these criteria; of these, 35 patients (7.0%) developed radiation proctitis necessitating intervention with APC. Indications for APC treatment were either the need for blood transfusions resulting from proctitis-related anemia or refractory bleeding despite medical management. The median follow-up from the completion of radiation treatment was 78 months (range, 19-129) and the median follow up from the most recent APC treatment was 56 months (range, 3-112). Fifteen men (42.9%) needed blood transfusions because of proctitis-related ane...
Copper complexes of tertiary amine ligands have emerged as the catalysts of choice in the extensi... more Copper complexes of tertiary amine ligands have emerged as the catalysts of choice in the extensively employed atom transfer radical polymerization (ATRP) protocol. The halide ligand substitution reactions of five-coordinate copper(II) complexes of tris[2-(dimethylamino)ethyl]amine (Me6tren), one of the most active ATRP catalysts, has been studied in a range of organic solvents using stopped-flow techniques. The kinetic and activation parameters indicate that substitution reactions on [Cu(II)(Me6tren)X](+) (X(-) = Cl(-) and Br(-)) and [Cu(II)(Me6tren)(Solv)](2+) (Solv = MeCN, DMF, DMSO, MeOH, EtOH) are dissociatively activated; this behavior is independent of the solvent used. Adjusting the effective concentration of the solvent by addition of an olefinic monomer to the solution does not affect the kinetics of the halide binding (kon) but can alter the outer-sphere association equilibrium constant (KOS) between reactants prior to the formal ligand substitution. Halide (X(-)/Y(-)) ex...
Senescence-associated proteolysis in plants is a complex and controlled process, essential for mo... more Senescence-associated proteolysis in plants is a complex and controlled process, essential for mobilization of nutrients from old or stressed tissues, mainly leaves, to growing or sink organs. Protein breakdown in senescing leaves involves many plastidial and nuclear proteases, regulators, different subcellular locations and dynamic protein traffic to ensure the complete transformation of proteins of high molecular weight into transportable and useful hydrolysed products. Protease activities are strictly regulated by specific inhibitors and through the activation of zymogens to develop their proteolytic activity at the right place and at the proper time. All these events associated with senescence have deep effects on the relocation of nutrients and as a consequence, on grain quality and crop yield. Thus, it can be considered that nutrient recycling is the common destiny of two processes, plant senescence and, proteolysis. This review article covers the most recent findings about leaf senescence features mediated by abiotic and biotic stresses as well as the participants and steps required in this physiological process, paying special attention to C1A cysteine proteases, their specific inhibitors, known as cystatins, and their potential targets, particularly the chloroplastic proteins as source for nitrogen recycling.
Latin American Journal of Solids and Structures an Abcm Journal, Feb 7, 2015
ABSTRACT The analysis of cracked brittle mechanical components considering linear elastic fractur... more ABSTRACT The analysis of cracked brittle mechanical components considering linear elastic fracture mechanics is usually reduced to the evaluation of stress intensity factors (SIFs). The SIF calculation can be carried out experimentally, theoretically or numerically. Each methodology has its own advantages but the use of numerical methods has become very popular. Several schemes for numerical SIF calculations have been developed, the J-integral method being one of the most widely used because of its energy-like formulation. Additionally, some variations of the J-integral method, such as displacement-based methods, are also becoming popular due to their simplicity. In this work, a simple displacement-based scheme is proposed to calculate SIFs, and its performance is compared with contour integrals. These schemes are all implemented with the Boundary Element Method (BEM) in order to exploit its advantages in crack growth modelling. Some simple examples are solved with the BEM and the calculated SIF values are compared against available solutions, showing good agreement between the different schemes.
International Journal of Neuroscience, Sep 1, 1988
An attempt was made in two experiments to reinvestigate the effects of the antiandrogen cyprotero... more An attempt was made in two experiments to reinvestigate the effects of the antiandrogen cyproterone acetate (CA) on mouse social behavior in a variety of ethologically-assessed paired encounters. The data confirm that CA reduces offense (threat and attack) in animals when both subjects receive the material but that CA has no such action in other pairings. This suggests that CA's major suppressive effect on "hostility" is expressed in mice via a reduction in "attack-promoting" pheromone production. Indeed, there was evidence in the more chronic study that CA, could augment (via a central mechanism?) offense in subjects paired with docile anosmic opponents. Changes in defense were largely responses to variations in the degree of attack to which animals were subjected. The antihormone also had actions on other aspects of behavior including sexual activity, social investigation and immobility in such tests. CA had a potent suppressive action on the weights of sex accessory glands. The data do not suggest that CA can be used as a specific antihostility agent.
Recent studies suggest that motivations for certain forms of masculine behavior including social ... more Recent studies suggest that motivations for certain forms of masculine behavior including social aggression are mediated by central estrogen receptors. Two studies using antiestrogens in rodent species were performed. Intact male LH rats were given Tamoxifen or vehicle for 4 or 8 days. The three possible pairings were videotaped for 60 min. Intact male OF1 mice were given CI-680 or vehicle over 25 days. Similar pairings were carried out but some CI-680 or vehicle animals were paired with anosmic opponents. Encounters were videotaped for 10 min. In both experiments evidence was obtained that the antiestrogen markedly reduced time allocated to offense. Any variations in defense were a consequence of the level of attack to which animals were subjected. Neither compound greatly influenced the androgen-dependent sex accessory glands. Antiestrogens consequently have potential as antihostility agents in some forms of attack.
An efficient and general preparation of S-(alkoxycarbonyl)-O-alkyldithiocarbonates is described. ... more An efficient and general preparation of S-(alkoxycarbonyl)-O-alkyldithiocarbonates is described. The method is based on the reaction of potassium O-alkylmonothiocarbonates with O-alkylchlorothiocarbonates in acetone-water (9:1) at 0°C. The yields are 91–100%.
A detailed study under forward-bias conditions of the physical origin of high frequency noise in ... more A detailed study under forward-bias conditions of the physical origin of high frequency noise in p+(Si)-n (Si1-xGex) heterojunctions using ensemble Monte Carlo simulation is reported. Based on the internal magnitudes, we determine how the strained SiGe layer induces different features in the perpendicular transport of a heterojunction as compared with that of a silicon p+n homojunction. The main part of
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Papers by Manuel Martinez,-Rivera M.D.