We report the observation of sustained self-pulsing behavior of the output of a channel waveguide... more We report the observation of sustained self-pulsing behavior of the output of a channel waveguide Nd:YAG laser under a CW pump. The duration and repetition rate of the pulses observed were dependent on the pumping power. At the maximum pumping power available (44 mW of absorbed power), the pulse duration was around ∼40 ns, and the pulse repetition rate was ∼1.4 MHz. We discuss the possible physical mechanisms that generate the pulsing behavior, and their implications on the observed pump-power dependence of the repetition rate.
We undertook this study to evaluate the functional impact of coronary abnormalities in patients w... more We undertook this study to evaluate the functional impact of coronary abnormalities in patients with suspected coronary artery disease (CAD) by means of integrated positron emission tomography (PET) and coronary computed tomography angiography (CCTA) scan obtained on a hybrid state-of-the-art PET/CT scanner.We studied 29 consecutive, patients with a clinically suspected intermediate risk for CAD, using a hybrid PET/CT 64 slice scanner. During a single scanning session, CCTA was performed for coronary anatomy evaluation, and a rest/adenosine stress 13N-ammonia PET was performed for myocardial perfusion assessment in 3D mode with CT attenuation correction.Twenty four (82.7%) patients had atherosclerosis detected by CCTA; 15 patients had significant (≥50%) coronary stenoses and all 15 patients showed ischemia by PET; moreover, 10/15 patients had a Summed Stress Score >12.20/24 and 83.3% patients with atherosclerosis detected by CCTA showed ischemia by PET. Two of five patients with normal coronary arteries showed ischemia by PET. CCTA agreement in positive identification of PET ischemia was 91% and agreement in ruling out ischemia was 43%; PET agreement in detecting CCTA atherosclerosis was 83%, and agreement in ruling it out was 60%.We found a strong relation between significant coronary stenosis identified by CCTA and ischemia by PET. However, in cases with low-grade stenosis, PET scan can assess the functional significance of atherosclerotic abnormalities.
Background In 2002, 17.8% of the global cancer burden was attributable to infections. This study ... more Background In 2002, 17.8% of the global cancer burden was attributable to infections. This study assessed the age-standardized incidence and mortality rates of stomach, liver, and cervical cancer in Puerto Rico (PR) for the period 1992-2003 and compared them to those of Hispanics (USH), non-Hispanic Whites (NHW), and non-Hispanic Blacks (NHB) in the United States (US). Methods Age-standardized rates [ASR(World)] were calculated based on cancer incidence and mortality data from the PR Cancer Central Registry and SEER, using the direct method and the world population as the standard. Annual percent changes (APC) were calculated using the Poisson regression model from 1992-2003. Results The incidence and mortality rates from stomach, liver and cervical cancer were lower in NHW than PR; with the exception of mortality from cervical cancer which was similar in both populations. Meanwhile, the incidence rates of stomach, liver and cervical cancers were similar between NHB and PR; except for NHB women who had a lower incidence rate of liver cancer than women in PR. NHB had a lower mortality from liver cancer than persons in PR, and similar mortality from stomach cancer. Conclusions The burden of liver, stomach, and cervical cancer in PR compares to that of USH and NHB and continues to be a public health priority. Public health efforts are necessary to further decrease the burden of cancers associated to infections in these groups, the largest minority population groups in the US. Future studies need to identify factors that may prevent infections with cancer-related agents in these populations. Strategies to increase the use of preventive strategies, such as vaccination and screening, among minority populations should also be developed.
... Erick Alexanderson1,2,*, Jose Luis Romero1, Alejandro Ricalde1, Graciela Alexanderson3 and Al... more ... Erick Alexanderson1,2,*, Jose Luis Romero1, Alejandro Ricalde1, Graciela Alexanderson3 and Aloha Meave2 ... [36] Buus NH Hermansen F, Sander M, Nielsen TT, Mulvany MJ. ... [37] Nitenberg A, Ledoux S, Valensi P, Sachs R, Attali JR, Antony I. Impairment of coronary ...
We report the observation of sustained self-pulsing behavior of the output of a channel waveguide... more We report the observation of sustained self-pulsing behavior of the output of a channel waveguide Nd:YAG laser under a CW pump. The duration and repetition rate of the pulses observed were dependent on the pumping power. At the maximum pumping power available (44 mW of absorbed power), the pulse duration was around ∼40 ns, and the pulse repetition rate was ∼1.4 MHz. We discuss the possible physical mechanisms that generate the pulsing behavior, and their implications on the observed pump-power dependence of the repetition rate.
We undertook this study to evaluate the functional impact of coronary abnormalities in patients w... more We undertook this study to evaluate the functional impact of coronary abnormalities in patients with suspected coronary artery disease (CAD) by means of integrated positron emission tomography (PET) and coronary computed tomography angiography (CCTA) scan obtained on a hybrid state-of-the-art PET/CT scanner.We studied 29 consecutive, patients with a clinically suspected intermediate risk for CAD, using a hybrid PET/CT 64 slice scanner. During a single scanning session, CCTA was performed for coronary anatomy evaluation, and a rest/adenosine stress 13N-ammonia PET was performed for myocardial perfusion assessment in 3D mode with CT attenuation correction.Twenty four (82.7%) patients had atherosclerosis detected by CCTA; 15 patients had significant (≥50%) coronary stenoses and all 15 patients showed ischemia by PET; moreover, 10/15 patients had a Summed Stress Score >12.20/24 and 83.3% patients with atherosclerosis detected by CCTA showed ischemia by PET. Two of five patients with normal coronary arteries showed ischemia by PET. CCTA agreement in positive identification of PET ischemia was 91% and agreement in ruling out ischemia was 43%; PET agreement in detecting CCTA atherosclerosis was 83%, and agreement in ruling it out was 60%.We found a strong relation between significant coronary stenosis identified by CCTA and ischemia by PET. However, in cases with low-grade stenosis, PET scan can assess the functional significance of atherosclerotic abnormalities.
Background In 2002, 17.8% of the global cancer burden was attributable to infections. This study ... more Background In 2002, 17.8% of the global cancer burden was attributable to infections. This study assessed the age-standardized incidence and mortality rates of stomach, liver, and cervical cancer in Puerto Rico (PR) for the period 1992-2003 and compared them to those of Hispanics (USH), non-Hispanic Whites (NHW), and non-Hispanic Blacks (NHB) in the United States (US). Methods Age-standardized rates [ASR(World)] were calculated based on cancer incidence and mortality data from the PR Cancer Central Registry and SEER, using the direct method and the world population as the standard. Annual percent changes (APC) were calculated using the Poisson regression model from 1992-2003. Results The incidence and mortality rates from stomach, liver and cervical cancer were lower in NHW than PR; with the exception of mortality from cervical cancer which was similar in both populations. Meanwhile, the incidence rates of stomach, liver and cervical cancers were similar between NHB and PR; except for NHB women who had a lower incidence rate of liver cancer than women in PR. NHB had a lower mortality from liver cancer than persons in PR, and similar mortality from stomach cancer. Conclusions The burden of liver, stomach, and cervical cancer in PR compares to that of USH and NHB and continues to be a public health priority. Public health efforts are necessary to further decrease the burden of cancers associated to infections in these groups, the largest minority population groups in the US. Future studies need to identify factors that may prevent infections with cancer-related agents in these populations. Strategies to increase the use of preventive strategies, such as vaccination and screening, among minority populations should also be developed.
... Erick Alexanderson1,2,*, Jose Luis Romero1, Alejandro Ricalde1, Graciela Alexanderson3 and Al... more ... Erick Alexanderson1,2,*, Jose Luis Romero1, Alejandro Ricalde1, Graciela Alexanderson3 and Aloha Meave2 ... [36] Buus NH Hermansen F, Sander M, Nielsen TT, Mulvany MJ. ... [37] Nitenberg A, Ledoux S, Valensi P, Sachs R, Attali JR, Antony I. Impairment of coronary ...
Uploads
Papers by Erick Romero