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Papers by dominique jones

Research paper thumbnail of Use of virtual and augmented reality-based interventions in health education to improve dementia knowledge and attitudes: an integrative review

BMJ Open, Nov 1, 2021

Use of virtual and augmented reality-based interventions in health education to improve dementia ... more Use of virtual and augmented reality-based interventions in health education to improve dementia knowledge and attitudes: an integrative review. BMJ Open 2021;11:e053616.

Research paper thumbnail of Use of virtual and augmented reality-based interventions in health education to improve dementia knowledge and attitudes: an integrative review

BMJ Open, 2021

ObjectivesImmersive technologies such as virtual (VR) and augmented reality (AR) can potentially ... more ObjectivesImmersive technologies such as virtual (VR) and augmented reality (AR) can potentially help health professionals and trainees understand psychological symptoms and responsive behaviours associated with dementia within a safe and supportive learning environment. This integrative review sought to ascertain the types of VR and AR-based interventions used in dementia education and training and its efficacy to improve knowledge and attitudes of health professionals or trainees.DesignThe protocol was submitted to PROSPERO and literature published from 2000 onwards was searched in eight databases: CINAHL, MEDLINE, Web of Science, Cochrane, Embase, PsycINFO, ERIC and Scopus. A total of 19 articles were included and assessed with the Mixed Methods Appraisal Tool. Methodological quality varied across studies.ResultsVR rather than AR-based intervention are used in dementia education and training for health professional and trainees. Immersive virtual learning potentially enhance know...

Research paper thumbnail of miRNAs associated with prostate cancer risk and progression

BMC urology, Jan 20, 2017

Prostate cancer is the most common malignancy among men in the US. Though considerable improvemen... more Prostate cancer is the most common malignancy among men in the US. Though considerable improvement in the diagnosis of prostate cancer has been achieved in the past decade, predicting disease outcome remains a major clinical challenge. Recent expression profiling studies in prostate cancer suggest microRNAs (miRNAs) may serve as potential biomarkers for prostate cancer risk and disease progression. miRNAs comprise a large family of about 22-nucleotide-long non-protein coding RNAs, regulate gene expression post-transcriptionally and participate in the regulation of numerous cellular processes. In this review, we discuss the current status of miRNA in studies evaluating the disease progression of prostate cancer. The discussion highlights key findings from previous studies, which reported the role of miRNAs in risk and progression of prostate cancer, providing an understanding of the influence of miRNA on prostate cancer. Our review indicates that somewhat consistent results exist bet...

Research paper thumbnail of The Influence of Maternal Exercise Type on Heart Measures at One Month

Research paper thumbnail of Additional file 4 of Micro-RNA-186-5p inhibition attenuates proliferation, anchorage independent growth and invasion in metastatic prostate cancer cells

Table S3. Aberrant gene expression in miR-186-5p inhibited PC-3 and miR-186-5p overexpressing RWP... more Table S3. Aberrant gene expression in miR-186-5p inhibited PC-3 and miR-186-5p overexpressing RWPE1 cells. Microarray gene list was restricted to genes down-regulated in RWPE1 (fold change ≤ − 1.2) and up-regulated in PC-3 cells (fold change ≥1.2). Analysis revealed a down-regulation of 493 transcripts in RWPE1 cells and up-regulation of 547 transcripts in PC-3 cells. Genes in bold represent previously validated miR-186-5p targets. Moreover, genes were highlighted gray if modified in both RWPE1 with ectopic expression of miR-186-5p and miR-186-5p inhibited PC-3 cells. (DOCX 81 kb)

Research paper thumbnail of Additional file 3 of Micro-RNA-186-5p inhibition attenuates proliferation, anchorage independent growth and invasion in metastatic prostate cancer cells

Figure S1. Transient and stable miR-186-5p inhibition and overexpression in prostate cancer and n... more Figure S1. Transient and stable miR-186-5p inhibition and overexpression in prostate cancer and normal epithelial cells. miR-186-5p expression was measured following 24–48 h transient post-transfection and stable transfection using qRT-PCR. A) Following transient transfection of cell models with miR-186-5p inhibitor, miR-186-5p was reduced by 33–73% in PC-3 (p = 0.0002), MDA-PCA-2b (p = 0.0061) and LNCaP (p = 0.0381) cells. B) Ectopic expression of miR-186-5p in PC-3 (p = 0.0002), MDA-PCA-2b (p = 0.0061) and LNCaP (p = 0.0381) cells transiently transfected with miR-186-5p mimic. C) MiR-186-5p expression was reduced by 30% in PC-3 cells stably transfected with pcDNA-DEST-47-anti-miR-186 compared to pcDNA-DEST-47 (empty vector) (p = 0.0022). MiR-186-5p was up-regulated by 2.55-fold in RWPE1 cells stably transfected with pcDNA-DEST-47-miR-186 mimic construct compared to the empty vector control (p = 0.0019). Data was quantitated from three independent experiments and are represented as...

Research paper thumbnail of Additional file 1 of Micro-RNA-186-5p inhibition attenuates proliferation, anchorage independent growth and invasion in metastatic prostate cancer cells

Table S1. De-identified demographic and clinico-pathological data. Clinical data and serum from 1... more Table S1. De-identified demographic and clinico-pathological data. Clinical data and serum from 15 men diagnosed with prostate cancer and five disease-free individuals were obtained from the BioServe Biotechnologies Biorepository (Beltsville, MD). Subjects were self-identified as European American males. There were no significant differences in median age between cases and controls (p = 0.726). Among men diagnosed with prostate cancer, 60% were diagnosed with adenocarcinoma, 66.7% were smokers, and 73.3% received two or more therapies. Relative to controls, cases had higher median serum PSA level (ng/ml) (p = 0.048) and BMI (p = 0.225) values. (DOCX 63 kb)

Research paper thumbnail of miR‐186 Inhibition Alters Cell Proliferation and Colony Formation in Prostate Cancer

Research paper thumbnail of A prospective study to identify rates of SARS-CoV-2 virus in the peritoneum and lower genital tract of patients having surgery

IntroductionThe risks to surgeons of carrying out aerosol generating procedures during the COVID ... more IntroductionThe risks to surgeons of carrying out aerosol generating procedures during the COVID pandemic are unknown. To start to define these risks, in a systematic manner, we investigated the presence of SARS-CoV-2 virus in the abdominal fluid and lower genital tract of patients undergoing surgery.MethodsWe carried out a prospective cross sectional observational study of 113 patients undergoing abdominal surgery or instrumentation of the lower genital tract. We took COVID swabs from the peritoneal cavity and from the vagina from all eligible patients. Results were stratified by pre operative COVID status.ResultsIn patients who were presumed COVID negative at the time of surgery SARS-CoV-2 virus RNA was detected in 0/102 peritoneal samples and 0/98 vaginal samples. Peritoneal and vaginal swabs were also negative in one patient who had a positive nasopharyngeal swab immediately prior to surgery.ConclusionsThe presence of SARS-CoV-2 RNA in the abdominal fluid or lower genital tract ...

Research paper thumbnail of Using Holograms to Enhance Learning in Health Sciences and Medicine

Medical Science Educator

With the increasing volume of information for students to learn in a health sciences and medicine... more With the increasing volume of information for students to learn in a health sciences and medicine degree, tertiary educators need teaching resources that can maintain up-to-date information and educate effectively across a range of diseases and illnesses. Holograms may be the disruptive technology that can assist in this goal.

Research paper thumbnail of ‘Until I talked with you’: Silence, Storytelling, and Black Sexual Intimacies in the Johns Committee Records, 1960-5

Research paper thumbnail of Accelerated and long term stability study of Pfs25-EPA conjugates adjuvanted with Alhydrogel®

Vaccine, Jan 4, 2017

Pfs25, a Plasmodium falciparum surface protein expressed during zygote and ookinete stages in inf... more Pfs25, a Plasmodium falciparum surface protein expressed during zygote and ookinete stages in infected mosquitoes, is a lead transmission-blocking vaccine candidate against falciparum malaria. To enhance immunogenicity, recombinant Pfs25 was chemically conjugated to recombinant nontoxic Pseudomonas aeruginosa ExoProtein A (rEPA) in conformance with current good manufacturing practices (cGMP), and formulated with the alum adjuvant Alhydrogel. In order to meet the regulatory requirements for a phase 1 human clinical trial, the vaccine product was extensively evaluated for stability at an initial time point and through the clinical trial period annually. Because basic quality control methods to characterize alum-based vaccines remain unavailable, a thermal forced degradation study was performed prior to the initial evaluation to identify the methods suitable to detect the quality of vaccine formulations. Our results show that the vaccine product Pfs25-EPA formulated on Alhydrogel is in...

Research paper thumbnail of Analysis of Te and TeO<sub>2</sub> on CdZnTe Nuclear Detectors Treated with Hydrogen Bromide and Ammonium-Based Solutions

Journal of Materials Science and Chemical Engineering, 2017

Surface defects caused during cutting and polishing in the fabrication of cadmium zinc telluride ... more Surface defects caused during cutting and polishing in the fabrication of cadmium zinc telluride (CdZnTe) nuclear detectors limit their spectral performance. Chemical treatments are often used to remove surface damages and defects. In this paper, we present the analysis of Te and TeO 2 species on the surfaces of CdZnTe nuclear detectors treated with hydrogen bromide and ammonium-based solutions. The CdZnTe wafers were chemo-mechanically polished in a mixture of hydrogen bromide in hydrogen peroxide and ethylene glycol, followed by a chemical passivation in a mixture of ammonium fluoride and hydrogen peroxide solution. X-ray photoelectron spectroscopy showed significant conversion of Te to TeO 2 , thus producing a more chemically stable surface. The resistivity of the CdZnTe samples is in the order of 10 10 ohms-cm. The current for a given applied voltage increased following the passivation and decreased after a 3-hour period. Results from spectral response measurements showed that the 59.5-keV gamma-peak of Am-241 was stable under the same channel for the surface treatment processes.

Research paper thumbnail of Role of human pregnane X receptor in high fat diet-induced obesity in pre-menopausal female mice

Biochemical Pharmacology, 2014

Obesity is a complex metabolic disorder that is more prevalent among women. Until now, the only r... more Obesity is a complex metabolic disorder that is more prevalent among women. Until now, the only relevant rodent models of diet-induced obesity were via the use of ovariectomized (''postmenopausal'') females. However, recent reports suggest that the xenobiotic nuclear receptor pregnane X receptor (PXR) may contribute to obesity. Therefore, we compared the roles of mouse and human PXRs in diet-induced obesity between wild type (WT) and PXR-humanized (hPXR) transgenic female mice fed either control or high-fat diets (HFD) for 16 weeks. HFD-fed hPXR mice gained weight more rapidly than controls, exhibited hyperinsulinemia, and impaired glucose tolerance. Fundamental differences were observed between control-fed hPXR and WT females: hPXR mice possessed reduced estrogen receptor a (ERa) but enhanced uncoupling protein 1 (UCP1) protein expression in white adipose tissue (WAT); increased protein expression of the hepatic cytochrome P450 3A11 (CYP3A11) and key gluconeogenic enzymes phosphoenolpyruvate carboxykinase and glucose 6-phosphatase, and increased total cholesterol. Interestingly, HFD ingestion induced both UCP1 and glucokinase protein expression in WT mice, but inhibited these enzymes in hPXR females. Unlike WT mice, CYP3A11 protein, serum 17b-estradiol levels, and WAT ERa expression were unaffected by HFD in hPXR females. Together, these studies indicate that the hPXR gene promotes obesity and metabolic syndrome by dysregulating lipid and glucose homeostasis while inhibiting UCP1 expression. Furthermore, our studies indicate that the human PXR suppresses the protective role of estrogen in metabolic disorders. Finally, these data identify PXRhumanized mice as a promising in vivo research model for studying obesity and diabetes in women.

Research paper thumbnail of Novel Approach to Surface Processing for Improving the Efficiency of CdZnTe Detectors

Journal of Electronic Materials, 2013

ABSTRACT We emphasize an improvement of the surface processing procedures for cadmium zinc tellur... more ABSTRACT We emphasize an improvement of the surface processing procedures for cadmium zinc telluride (CZT) detectors, which is one of the principal problems limiting the technology. A rough surface enhances the leakage current into the medium, creating additional trapping centers and thereby degrading the detector’s performance. Mechanical polishing followed by chemical treatment yields smoother surfaces as required, but chemical treatment, especially with bromine-based solutions, induces unwanted surface features, increases the surface conductivity, and generates chemical species that alter the material’s surface and interfacial properties. It is essential to avoid such adverse consequences of surface etching in the manufacturing of highly efficient radiation detectors. We approached the problem of processing the crystals’ surfaces by using two different solutions (a low-concentration bromine-based etchant mixture in conjunction with a surface-passivation reagent and a non-bromine-based etchant). The chemomechanical treatment yielded smooth nonconductive surfaces with fewer detrimental features, therefore allowing us to fabricate better devices. We determined the surface roughness using atomic force microscopy and optical profilometry (OP). We analyzed the surface structure, orientations of the crystals, and formation of chemical species by x-ray photoelectron spectroscopy techniques and delineated their effects on the devices’ electrical properties and performance. Our experimental data revealed that our new chemical etching process produced nonconductive surfaces with fewer surface defects and so improved the detectors’ charge transport and efficiency. We detail the results of our new etchants and compare them with those for conventional Br-methanol etchants.

Research paper thumbnail of Analysis of the Conformation and Function of the Plasmodium falciparum Merozoite Proteins MTRAP and PTRAMP

Eukaryotic Cell, 2012

Thrombospondin repeat (TSR)-like domains are structures involved with cell adhesion. Plasmodium f... more Thrombospondin repeat (TSR)-like domains are structures involved with cell adhesion. Plasmodium falciparum proteins containing TSR domains play crucial roles in parasite development. In particular, the preerythrocytic P. falciparum circumsporozoite protein is involved in hepatocyte invasion. The importance of these domains in two other malaria proteins, the merozoite-specific thrombospondin-related anonymous protein (MTRAP) and the thrombospondin-related apical membrane protein (PTRAMP), were assessed using near-full-length recombinant proteins composed of the extracellular domains produced in Escherichia coli . MTRAP is thought to be released from invasive organelles identified as micronemes during merozoite invasion to mediate motility and host cell invasion through an interaction with aldolase, an actin binding protein involved in the moving junction. PTRAMP function remains unknown. In this study, the conformation of recombinant MTRAP (rMTRAP) appeared to be a highly extended pr...

Research paper thumbnail of Study of surface passivation and contact deposition techniques in CdZnTe X-Ray and gamma-ray detectors

Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), vol., no., pp.4124,4127; doi: 10.1109/NSSMIC.2012.6551942, Oct 27, 2012

Passivation and improved contact deposition techniques are known to reduce the surface leakage cu... more Passivation and improved contact deposition techniques are known to reduce the surface leakage current and decrease noise levels of CdZnTe X-Ray and gamrna-ray detectors by improving their spectral energy resolutions. This paper presents a comparative study of surface passivation process in CdZnTe X-Ray and gamma-ray detectors. The experimental study compares three surface passivation processes: mechanically polished with a O.9μm Alumina Powder (AI2O3) finishing; mechanically polished with a O.9μm Alumina Powder (AI2O3) and etched with HBr + H2O2 solution for 2 minutes; mechanically polished with a O.9,.m Alumina Powder (AI2O3) and chemomechanically polished with bromine-methanol-ethylene glycol solution. The results show that chemo-mechanical polishing with bromine-methanol-ethylene glycol solution proved to be the best method out of the three for reducing surface leakage current. The preliminary results of aging studies on H2O2 (Hydrogen Peroxide), NH4F (Ammonium Fluoride) + H2O2 ...

Research paper thumbnail of Use of virtual and augmented reality-based interventions in health education to improve dementia knowledge and attitudes: an integrative review

BMJ Open, Nov 1, 2021

Use of virtual and augmented reality-based interventions in health education to improve dementia ... more Use of virtual and augmented reality-based interventions in health education to improve dementia knowledge and attitudes: an integrative review. BMJ Open 2021;11:e053616.

Research paper thumbnail of Use of virtual and augmented reality-based interventions in health education to improve dementia knowledge and attitudes: an integrative review

BMJ Open, 2021

ObjectivesImmersive technologies such as virtual (VR) and augmented reality (AR) can potentially ... more ObjectivesImmersive technologies such as virtual (VR) and augmented reality (AR) can potentially help health professionals and trainees understand psychological symptoms and responsive behaviours associated with dementia within a safe and supportive learning environment. This integrative review sought to ascertain the types of VR and AR-based interventions used in dementia education and training and its efficacy to improve knowledge and attitudes of health professionals or trainees.DesignThe protocol was submitted to PROSPERO and literature published from 2000 onwards was searched in eight databases: CINAHL, MEDLINE, Web of Science, Cochrane, Embase, PsycINFO, ERIC and Scopus. A total of 19 articles were included and assessed with the Mixed Methods Appraisal Tool. Methodological quality varied across studies.ResultsVR rather than AR-based intervention are used in dementia education and training for health professional and trainees. Immersive virtual learning potentially enhance know...

Research paper thumbnail of miRNAs associated with prostate cancer risk and progression

BMC urology, Jan 20, 2017

Prostate cancer is the most common malignancy among men in the US. Though considerable improvemen... more Prostate cancer is the most common malignancy among men in the US. Though considerable improvement in the diagnosis of prostate cancer has been achieved in the past decade, predicting disease outcome remains a major clinical challenge. Recent expression profiling studies in prostate cancer suggest microRNAs (miRNAs) may serve as potential biomarkers for prostate cancer risk and disease progression. miRNAs comprise a large family of about 22-nucleotide-long non-protein coding RNAs, regulate gene expression post-transcriptionally and participate in the regulation of numerous cellular processes. In this review, we discuss the current status of miRNA in studies evaluating the disease progression of prostate cancer. The discussion highlights key findings from previous studies, which reported the role of miRNAs in risk and progression of prostate cancer, providing an understanding of the influence of miRNA on prostate cancer. Our review indicates that somewhat consistent results exist bet...

Research paper thumbnail of The Influence of Maternal Exercise Type on Heart Measures at One Month

Research paper thumbnail of Additional file 4 of Micro-RNA-186-5p inhibition attenuates proliferation, anchorage independent growth and invasion in metastatic prostate cancer cells

Table S3. Aberrant gene expression in miR-186-5p inhibited PC-3 and miR-186-5p overexpressing RWP... more Table S3. Aberrant gene expression in miR-186-5p inhibited PC-3 and miR-186-5p overexpressing RWPE1 cells. Microarray gene list was restricted to genes down-regulated in RWPE1 (fold change ≤ − 1.2) and up-regulated in PC-3 cells (fold change ≥1.2). Analysis revealed a down-regulation of 493 transcripts in RWPE1 cells and up-regulation of 547 transcripts in PC-3 cells. Genes in bold represent previously validated miR-186-5p targets. Moreover, genes were highlighted gray if modified in both RWPE1 with ectopic expression of miR-186-5p and miR-186-5p inhibited PC-3 cells. (DOCX 81 kb)

Research paper thumbnail of Additional file 3 of Micro-RNA-186-5p inhibition attenuates proliferation, anchorage independent growth and invasion in metastatic prostate cancer cells

Figure S1. Transient and stable miR-186-5p inhibition and overexpression in prostate cancer and n... more Figure S1. Transient and stable miR-186-5p inhibition and overexpression in prostate cancer and normal epithelial cells. miR-186-5p expression was measured following 24–48 h transient post-transfection and stable transfection using qRT-PCR. A) Following transient transfection of cell models with miR-186-5p inhibitor, miR-186-5p was reduced by 33–73% in PC-3 (p = 0.0002), MDA-PCA-2b (p = 0.0061) and LNCaP (p = 0.0381) cells. B) Ectopic expression of miR-186-5p in PC-3 (p = 0.0002), MDA-PCA-2b (p = 0.0061) and LNCaP (p = 0.0381) cells transiently transfected with miR-186-5p mimic. C) MiR-186-5p expression was reduced by 30% in PC-3 cells stably transfected with pcDNA-DEST-47-anti-miR-186 compared to pcDNA-DEST-47 (empty vector) (p = 0.0022). MiR-186-5p was up-regulated by 2.55-fold in RWPE1 cells stably transfected with pcDNA-DEST-47-miR-186 mimic construct compared to the empty vector control (p = 0.0019). Data was quantitated from three independent experiments and are represented as...

Research paper thumbnail of Additional file 1 of Micro-RNA-186-5p inhibition attenuates proliferation, anchorage independent growth and invasion in metastatic prostate cancer cells

Table S1. De-identified demographic and clinico-pathological data. Clinical data and serum from 1... more Table S1. De-identified demographic and clinico-pathological data. Clinical data and serum from 15 men diagnosed with prostate cancer and five disease-free individuals were obtained from the BioServe Biotechnologies Biorepository (Beltsville, MD). Subjects were self-identified as European American males. There were no significant differences in median age between cases and controls (p = 0.726). Among men diagnosed with prostate cancer, 60% were diagnosed with adenocarcinoma, 66.7% were smokers, and 73.3% received two or more therapies. Relative to controls, cases had higher median serum PSA level (ng/ml) (p = 0.048) and BMI (p = 0.225) values. (DOCX 63 kb)

Research paper thumbnail of miR‐186 Inhibition Alters Cell Proliferation and Colony Formation in Prostate Cancer

Research paper thumbnail of A prospective study to identify rates of SARS-CoV-2 virus in the peritoneum and lower genital tract of patients having surgery

IntroductionThe risks to surgeons of carrying out aerosol generating procedures during the COVID ... more IntroductionThe risks to surgeons of carrying out aerosol generating procedures during the COVID pandemic are unknown. To start to define these risks, in a systematic manner, we investigated the presence of SARS-CoV-2 virus in the abdominal fluid and lower genital tract of patients undergoing surgery.MethodsWe carried out a prospective cross sectional observational study of 113 patients undergoing abdominal surgery or instrumentation of the lower genital tract. We took COVID swabs from the peritoneal cavity and from the vagina from all eligible patients. Results were stratified by pre operative COVID status.ResultsIn patients who were presumed COVID negative at the time of surgery SARS-CoV-2 virus RNA was detected in 0/102 peritoneal samples and 0/98 vaginal samples. Peritoneal and vaginal swabs were also negative in one patient who had a positive nasopharyngeal swab immediately prior to surgery.ConclusionsThe presence of SARS-CoV-2 RNA in the abdominal fluid or lower genital tract ...

Research paper thumbnail of Using Holograms to Enhance Learning in Health Sciences and Medicine

Medical Science Educator

With the increasing volume of information for students to learn in a health sciences and medicine... more With the increasing volume of information for students to learn in a health sciences and medicine degree, tertiary educators need teaching resources that can maintain up-to-date information and educate effectively across a range of diseases and illnesses. Holograms may be the disruptive technology that can assist in this goal.

Research paper thumbnail of ‘Until I talked with you’: Silence, Storytelling, and Black Sexual Intimacies in the Johns Committee Records, 1960-5

Research paper thumbnail of Accelerated and long term stability study of Pfs25-EPA conjugates adjuvanted with Alhydrogel®

Vaccine, Jan 4, 2017

Pfs25, a Plasmodium falciparum surface protein expressed during zygote and ookinete stages in inf... more Pfs25, a Plasmodium falciparum surface protein expressed during zygote and ookinete stages in infected mosquitoes, is a lead transmission-blocking vaccine candidate against falciparum malaria. To enhance immunogenicity, recombinant Pfs25 was chemically conjugated to recombinant nontoxic Pseudomonas aeruginosa ExoProtein A (rEPA) in conformance with current good manufacturing practices (cGMP), and formulated with the alum adjuvant Alhydrogel. In order to meet the regulatory requirements for a phase 1 human clinical trial, the vaccine product was extensively evaluated for stability at an initial time point and through the clinical trial period annually. Because basic quality control methods to characterize alum-based vaccines remain unavailable, a thermal forced degradation study was performed prior to the initial evaluation to identify the methods suitable to detect the quality of vaccine formulations. Our results show that the vaccine product Pfs25-EPA formulated on Alhydrogel is in...

Research paper thumbnail of Analysis of Te and TeO<sub>2</sub> on CdZnTe Nuclear Detectors Treated with Hydrogen Bromide and Ammonium-Based Solutions

Journal of Materials Science and Chemical Engineering, 2017

Surface defects caused during cutting and polishing in the fabrication of cadmium zinc telluride ... more Surface defects caused during cutting and polishing in the fabrication of cadmium zinc telluride (CdZnTe) nuclear detectors limit their spectral performance. Chemical treatments are often used to remove surface damages and defects. In this paper, we present the analysis of Te and TeO 2 species on the surfaces of CdZnTe nuclear detectors treated with hydrogen bromide and ammonium-based solutions. The CdZnTe wafers were chemo-mechanically polished in a mixture of hydrogen bromide in hydrogen peroxide and ethylene glycol, followed by a chemical passivation in a mixture of ammonium fluoride and hydrogen peroxide solution. X-ray photoelectron spectroscopy showed significant conversion of Te to TeO 2 , thus producing a more chemically stable surface. The resistivity of the CdZnTe samples is in the order of 10 10 ohms-cm. The current for a given applied voltage increased following the passivation and decreased after a 3-hour period. Results from spectral response measurements showed that the 59.5-keV gamma-peak of Am-241 was stable under the same channel for the surface treatment processes.

Research paper thumbnail of Role of human pregnane X receptor in high fat diet-induced obesity in pre-menopausal female mice

Biochemical Pharmacology, 2014

Obesity is a complex metabolic disorder that is more prevalent among women. Until now, the only r... more Obesity is a complex metabolic disorder that is more prevalent among women. Until now, the only relevant rodent models of diet-induced obesity were via the use of ovariectomized (''postmenopausal'') females. However, recent reports suggest that the xenobiotic nuclear receptor pregnane X receptor (PXR) may contribute to obesity. Therefore, we compared the roles of mouse and human PXRs in diet-induced obesity between wild type (WT) and PXR-humanized (hPXR) transgenic female mice fed either control or high-fat diets (HFD) for 16 weeks. HFD-fed hPXR mice gained weight more rapidly than controls, exhibited hyperinsulinemia, and impaired glucose tolerance. Fundamental differences were observed between control-fed hPXR and WT females: hPXR mice possessed reduced estrogen receptor a (ERa) but enhanced uncoupling protein 1 (UCP1) protein expression in white adipose tissue (WAT); increased protein expression of the hepatic cytochrome P450 3A11 (CYP3A11) and key gluconeogenic enzymes phosphoenolpyruvate carboxykinase and glucose 6-phosphatase, and increased total cholesterol. Interestingly, HFD ingestion induced both UCP1 and glucokinase protein expression in WT mice, but inhibited these enzymes in hPXR females. Unlike WT mice, CYP3A11 protein, serum 17b-estradiol levels, and WAT ERa expression were unaffected by HFD in hPXR females. Together, these studies indicate that the hPXR gene promotes obesity and metabolic syndrome by dysregulating lipid and glucose homeostasis while inhibiting UCP1 expression. Furthermore, our studies indicate that the human PXR suppresses the protective role of estrogen in metabolic disorders. Finally, these data identify PXRhumanized mice as a promising in vivo research model for studying obesity and diabetes in women.

Research paper thumbnail of Novel Approach to Surface Processing for Improving the Efficiency of CdZnTe Detectors

Journal of Electronic Materials, 2013

ABSTRACT We emphasize an improvement of the surface processing procedures for cadmium zinc tellur... more ABSTRACT We emphasize an improvement of the surface processing procedures for cadmium zinc telluride (CZT) detectors, which is one of the principal problems limiting the technology. A rough surface enhances the leakage current into the medium, creating additional trapping centers and thereby degrading the detector’s performance. Mechanical polishing followed by chemical treatment yields smoother surfaces as required, but chemical treatment, especially with bromine-based solutions, induces unwanted surface features, increases the surface conductivity, and generates chemical species that alter the material’s surface and interfacial properties. It is essential to avoid such adverse consequences of surface etching in the manufacturing of highly efficient radiation detectors. We approached the problem of processing the crystals’ surfaces by using two different solutions (a low-concentration bromine-based etchant mixture in conjunction with a surface-passivation reagent and a non-bromine-based etchant). The chemomechanical treatment yielded smooth nonconductive surfaces with fewer detrimental features, therefore allowing us to fabricate better devices. We determined the surface roughness using atomic force microscopy and optical profilometry (OP). We analyzed the surface structure, orientations of the crystals, and formation of chemical species by x-ray photoelectron spectroscopy techniques and delineated their effects on the devices’ electrical properties and performance. Our experimental data revealed that our new chemical etching process produced nonconductive surfaces with fewer surface defects and so improved the detectors’ charge transport and efficiency. We detail the results of our new etchants and compare them with those for conventional Br-methanol etchants.

Research paper thumbnail of Analysis of the Conformation and Function of the Plasmodium falciparum Merozoite Proteins MTRAP and PTRAMP

Eukaryotic Cell, 2012

Thrombospondin repeat (TSR)-like domains are structures involved with cell adhesion. Plasmodium f... more Thrombospondin repeat (TSR)-like domains are structures involved with cell adhesion. Plasmodium falciparum proteins containing TSR domains play crucial roles in parasite development. In particular, the preerythrocytic P. falciparum circumsporozoite protein is involved in hepatocyte invasion. The importance of these domains in two other malaria proteins, the merozoite-specific thrombospondin-related anonymous protein (MTRAP) and the thrombospondin-related apical membrane protein (PTRAMP), were assessed using near-full-length recombinant proteins composed of the extracellular domains produced in Escherichia coli . MTRAP is thought to be released from invasive organelles identified as micronemes during merozoite invasion to mediate motility and host cell invasion through an interaction with aldolase, an actin binding protein involved in the moving junction. PTRAMP function remains unknown. In this study, the conformation of recombinant MTRAP (rMTRAP) appeared to be a highly extended pr...

Research paper thumbnail of Study of surface passivation and contact deposition techniques in CdZnTe X-Ray and gamma-ray detectors

Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), vol., no., pp.4124,4127; doi: 10.1109/NSSMIC.2012.6551942, Oct 27, 2012

Passivation and improved contact deposition techniques are known to reduce the surface leakage cu... more Passivation and improved contact deposition techniques are known to reduce the surface leakage current and decrease noise levels of CdZnTe X-Ray and gamrna-ray detectors by improving their spectral energy resolutions. This paper presents a comparative study of surface passivation process in CdZnTe X-Ray and gamma-ray detectors. The experimental study compares three surface passivation processes: mechanically polished with a O.9μm Alumina Powder (AI2O3) finishing; mechanically polished with a O.9μm Alumina Powder (AI2O3) and etched with HBr + H2O2 solution for 2 minutes; mechanically polished with a O.9,.m Alumina Powder (AI2O3) and chemomechanically polished with bromine-methanol-ethylene glycol solution. The results show that chemo-mechanical polishing with bromine-methanol-ethylene glycol solution proved to be the best method out of the three for reducing surface leakage current. The preliminary results of aging studies on H2O2 (Hydrogen Peroxide), NH4F (Ammonium Fluoride) + H2O2 ...