Fatima Romero - Academia.edu (original) (raw)

Papers by Fatima Romero

Research paper thumbnail of Electrical and Microstructural Characteristics of Ohmic Contacts formation on AlGaN/GaN HEMT

Electrical and microstructural characterization of Ti/Al/Ti/Au ohmic contact scheme for AlGaN/GaN... more Electrical and microstructural characterization of Ti/Al/Ti/Au ohmic contact scheme for AlGaN/GaN heterostructures is presented. It has been found that the Al/Ti thickness ratio influences the Ga-Au phase formation, which is linked to the contact resistivity, and that an Al excess content leads to a rough surface. The thickness of the barrier layer (Ti) was found to play an important role to achieve simultaneously low ohmic contact resistance and good line edge definition, although it does not act as an effective diffusion barrier. The role of the thermal annealing cycles is also discussed.

Research paper thumbnail of Prevalence of HIV Antibodies in Pregnant Women With Increased Risk for AIDS

Health Care for Women International, 2009

The prevalence of Human immunodeficiency virus (HIV) antibodies in pregnant women varies widely b... more The prevalence of Human immunodeficiency virus (HIV) antibodies in pregnant women varies widely between industrialized and developing countries. There is a lack of information about the status of HIV-infected pregnant women with increased risk for AIDS. Our objective was to determine the prevalence of HIV antibodies in pregnant women with increased risk at the Hospital of Obstetrics and Gynecology of the Mexican Institute of Social Security, Leon, Mexico, from December 18, 2003, through February 28, 2006. In a cross-sectional study, 2,257 pregnant women with at least one risk factor for AIDS were recruited. In these women, a sample of blood to determine HIV antibodies was taken. There were two women with positive HIV antibodies; therefore, the HIV seroprevalence was 0.8 per 1,000. Of the two HIV-positive women, one of them had a history of chronic sexually transmitted diseases; she was married to a man who was working outside of our country for about 10 months, and also he had tattoos. The other HIV-positive woman had a history of chronic sexually transmitted diseases, and her husband had intercourse with different women. The risk factors of use of tattoos, migration to foreign countries, and use of injectable drugs were more frequent among the male partners than in the pregnant women (P < .001). We concluded that in our country as well as in other developing countries, the prevalence of HIV antibodies in pregnant women with risk factors is low but still present. Because a significant number of risk factors for AIDS also were found in their male partners, HIV testing should be performed in all pregnant women as well as in their male partners.

Research paper thumbnail of 2DEG Characteristics Improvement by N2-plasma exposure in GaN HEMT heterostructures

The lack of maturity in GaN HEMT processing is strongly limiting transistor expected performances... more The lack of maturity in GaN HEMT processing is strongly limiting transistor expected performances. RF-DC dispersion, known as current collapse, seems to be related with carriers being trapped at the AlGaN surface. The use of a preprocessing N2-plasma treatment of the surface seems to have no effective improvement, in comparison with that of the pre-passivation processing step. A set of

Research paper thumbnail of Day–Night Variation of Acute Myocardial Infarction in Obstructive Sleep Apnea

Journal of The American College of Cardiology, 2008

OBJECTIVES-To evaluate the day-night variation of acute myocardial infarction (MI) in patients wi... more OBJECTIVES-To evaluate the day-night variation of acute myocardial infarction (MI) in patients with obstructive sleep apnea (OSA).

Research paper thumbnail of Electrical and Microstructural Characteristics of Ohmic Contacts formation on AlGaN/GaN HEMT

Electrical and microstructural characterization of Ti/Al/Ti/Au ohmic contact scheme for AlGaN/GaN... more Electrical and microstructural characterization of Ti/Al/Ti/Au ohmic contact scheme for AlGaN/GaN heterostructures is presented. It has been found that the Al/Ti thickness ratio influences the Ga-Au phase formation, which is linked to the contact resistivity, and that an Al excess content leads to a rough surface. The thickness of the barrier layer (Ti) was found to play an important role to achieve simultaneously low ohmic contact resistance and good line edge definition, although it does not act as an effective diffusion barrier. The role of the thermal annealing cycles is also discussed.

Research paper thumbnail of Prevalence of HIV Antibodies in Pregnant Women With Increased Risk for AIDS

Health Care for Women International, 2009

The prevalence of Human immunodeficiency virus (HIV) antibodies in pregnant women varies widely b... more The prevalence of Human immunodeficiency virus (HIV) antibodies in pregnant women varies widely between industrialized and developing countries. There is a lack of information about the status of HIV-infected pregnant women with increased risk for AIDS. Our objective was to determine the prevalence of HIV antibodies in pregnant women with increased risk at the Hospital of Obstetrics and Gynecology of the Mexican Institute of Social Security, Leon, Mexico, from December 18, 2003, through February 28, 2006. In a cross-sectional study, 2,257 pregnant women with at least one risk factor for AIDS were recruited. In these women, a sample of blood to determine HIV antibodies was taken. There were two women with positive HIV antibodies; therefore, the HIV seroprevalence was 0.8 per 1,000. Of the two HIV-positive women, one of them had a history of chronic sexually transmitted diseases; she was married to a man who was working outside of our country for about 10 months, and also he had tattoos. The other HIV-positive woman had a history of chronic sexually transmitted diseases, and her husband had intercourse with different women. The risk factors of use of tattoos, migration to foreign countries, and use of injectable drugs were more frequent among the male partners than in the pregnant women (P < .001). We concluded that in our country as well as in other developing countries, the prevalence of HIV antibodies in pregnant women with risk factors is low but still present. Because a significant number of risk factors for AIDS also were found in their male partners, HIV testing should be performed in all pregnant women as well as in their male partners.

Research paper thumbnail of 2DEG Characteristics Improvement by N2-plasma exposure in GaN HEMT heterostructures

The lack of maturity in GaN HEMT processing is strongly limiting transistor expected performances... more The lack of maturity in GaN HEMT processing is strongly limiting transistor expected performances. RF-DC dispersion, known as current collapse, seems to be related with carriers being trapped at the AlGaN surface. The use of a preprocessing N2-plasma treatment of the surface seems to have no effective improvement, in comparison with that of the pre-passivation processing step. A set of

Research paper thumbnail of Day–Night Variation of Acute Myocardial Infarction in Obstructive Sleep Apnea

Journal of The American College of Cardiology, 2008

OBJECTIVES-To evaluate the day-night variation of acute myocardial infarction (MI) in patients wi... more OBJECTIVES-To evaluate the day-night variation of acute myocardial infarction (MI) in patients with obstructive sleep apnea (OSA).