Christian Angelo | Universitas Pendidikan Indonesia (UPI) Bandung (original) (raw)

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Papers by Christian Angelo

$Research paper thumbnail of Measurement of <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi mathvariant="normal">Γ</mi><mo stretchy="false">(</mo><msup><mi>Z</mi><mn>0</mn></msup><mo>→</mo><mi>b</mi><mover accent="true"><mi>b</mi><mo stretchy="true">‾</mo></mover><mo stretchy="false">)</mo><mi mathvariant="normal">/</mi><mi mathvariant="normal">Γ</mi><mo stretchy="false">(</mo><msup><mi>Z</mi><mn>0</mn></msup><mo>→</mo></mrow><annotation encoding="application/x-tex">\Gamma (Z^{0} \to b\overline{b}) / \Gamma (Z^{0} \to</annotation></semantics></math>Γ(Z0→bb)/Γ(Z0→ Hadrons using Impact Parameters and Leptons$

The fraction of bb e v ents in hadronic Z 0 decays has been measured from the yield of leptons in... more The fraction of bb e v ents in hadronic Z 0 decays has been measured from the yield of leptons in the data samples collected by O P AL in 1990 and 1991. A sample enriched in events containing Z 0 ! bb decays was obtained by requiring the presence of an electron or muon with high momentum and high momentum component transverse to the associated hadronic jet. After accounting for backgrounds and acceptances, a value of (Z 0 ! bb) (Z 0 ! hadrons) = 0 : 220 0:002 0:006 0:011 was obtained. The rst two errors reect the data statistics and the systematic uncertainties arising from detector modelling uncertainties, respectively. The third error includes systematic eects from b and c fragmentation and decay uncertainties.

Neuropharmacology, 1997

The effects of the metabotropic glutamate receptor antagonist (+)-cr-methyI-4-carboxyphenylglytin... more The effects of the metabotropic glutamate receptor antagonist (+)-cr-methyI-4-carboxyphenylglytine (MCPG) on performance in a water maze and in context-specific associative learning were examined in rats previously imlplanted with cannulae. MCPG (20.8 pg) injected intraventricularly (i.c.v.) before testing impaired the performance of rats in the spatial version of the Morris water maze, but l/10 of this dose did not. Memory retention, evaluated 24 hr post-training, was also affected by the high dose of MCPG. However, performance in a cued version of the water maze was not impaired by the high dose, excluding effects of the drug on perceptual faculties. The effects of the MCPG were further characterized on performance in another hippocampus-dependent spatial learning task, the context-dependent fear conditioning task. MCPG (20.8 pg, i.c.v.) did not interfere with conditioned freezing to context in this task. For comparison, a group of rats was injected with the NMDA receptor blocker MK801. MK801 at a dose that disrupted the performance in the spatial version of the Morris water maze (0.08 mg,kg), significantly reduced freezing compared to controls. These experiments indicate that MCPG-sensitive metabotropic receptors may be required for only a restricted subset of spatial learning tasks, while NMDA receptors may play an integral role in all spatial learning.

Current Genetics, 1994

The systematic sequencing of the yeast genome reveals the presence of many potential genes of unk... more The systematic sequencing of the yeast genome reveals the presence of many potential genes of unknown function. One way to approach their function is to define which regulatory system controls their transcription. This can also be accomplished by the detection of an upstream activation sequence (UAS). Such a detection can be done by computer, provided that the definition of a UAS includes sufficient and precise rules. We have established such rules for the UASs of the GAL4, RAP1 (RPG box), GCN4, and the HAP2/HAP3/HAP4 regulatory proteins, as well as for a motif (PAC) frequently found upstream of the genes of the RNA polymerase A and C subunits. These rules were applied to the chromosome III DNA sequence, and gave precise predictions.

Background/Aims: In type 2 diabetic patients, coronary artery disease (CAD) is usually detected a... more Background/Aims: In type 2 diabetic patients, coronary artery disease (CAD) is usually detected at an advanced stage due to a lack of symptoms. The aim of this study was to define which clinical parameters or noninvasive tests predict CAD in asymptomatic type 2 diabetic patients. Methods: One hundred fourteen asymptomatic type 2 diabetic patients were divided into two groups based on the number of cardiovascular disease (CVD) risk factors (group A ≥2, group B ≤1). Treadmill exercise ECG tests (TMT) were conducted in all cases, and coronary artery angiography was performed on TMT-positive patients. Clinical parameters, diabetic status, and coronary angiographic findings were analyzed. Results: The prevalence of CAD was 41.0% in group A and 16.7% in group B. The number of risk factors was significantly correlated with the prevalence of CAD, but not with the severity of CAD. Multivariate analysis showed that family history of CAD (odds ratio [OR]=9.41; 95% confidence interval [CI], 1.60-55.49) and diabetes duration ≥10 years (OR=3.28; 95% CI, 1.29-8.84) were independent CAD risk factors in asymptomatic patients. Conclusions: We recommend a routine screening for CAD in type 2 diabetic patients who have a longer (≥10 years) diabetic duration or a family history of CAD, even if they are asymptomatic for CAD. (Korean J Intern Med 2009;24:183-189)

$Research paper thumbnail of A Measurement of the Forward-Backward Asymmetry of <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>e</mi><mo lspace="0em" rspace="0em">+</mo></msup><msup><mi>e</mi><mo lspace="0em" rspace="0em">−</mo></msup><mo>→</mo><mi>c</mi><mover accent="true"><mi>c</mi><mo stretchy="true">‾</mo></mover></mrow><annotation encoding="application/x-tex">e^{+}e^{-} \to c\overline{c}</annotation></semantics></math>e+e−→cc and <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>e</mi><mo lspace="0em" rspace="0em">+</mo></msup><msup><mi>e</mi><mo lspace="0em" rspace="0em">−</mo></msup><mo>→</mo><mi>b</mi><mover accent="true"><mi>b</mi><mo stretchy="true">‾</mo></mover></mrow><annotation encoding="application/x-tex">e^{+}e^{-} \to b\overline{b}</annotation></semantics></math>e+e−→bb at Centre-of-Mass Energies on and near the <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><msup><mi>Z</mi><mn>0</mn></msup></mrow><annotation encoding="application/x-tex">Z^{0}</annotation></semantics></math>Z0 Peak using <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>D</mi><msup><mo>∗</mo><mo lspace="0em" rspace="0em">±</mo></msup></mrow><annotation encoding="application/x-tex">D*^{\pm}</annotation></semantics></math>D∗± Mesons$

Measurement of the forward-backward asymmetry of e +e-> Z --, bb using prompt leptons and a lifet... more Measurement of the forward-backward asymmetry of e +e-> Z --, bb using prompt leptons and a lifetime tag DELPHI Collaboration P.

Meteoritics & Planetary Science, 2006

Abstract— The proposed Sirente crater field consists of a slightly oblong main structure (main cr... more Abstract— The proposed Sirente crater field consists of a slightly oblong main structure (main crater) 120 m in width and about 30 smaller structures (satellite craters), all in unconsolidated but stiff carbonate mud. Here we focus on the subsurface structure of the satellite craters and compare the Sirente field with known meteorite crater fields. We present a more complete outline of the crater field than previously reported, information on the subsurface morphology of a satellite crater (C8) 8 m in width, radiocarbon and thermoluminescence (TL) ages of material from this crater, and evidence for heated material in both crater C8 and the rim of the main crater. Crater C8 has a funnel shape terminating downwards, and evidence for soil injection from the surface to a depth of 9 m. The infill contained dispersed charcoal and small, irregular, porous fragments of heated clay with a calibrated age of b.p. 1712 (13C-corrected radiocarbon age: b.p. 1800 ± 100) and a TL age of b.p. 1825 (calculated error ± 274). Together with previous radiocarbon age (b.p. 1538) of the formation of the main crater (i.e., target surface below rim), a formation is suggested at the beginning of the first millennium a.d. Although projectile vaporization is not expected in Sirente-sized craters in this type of target material, we used geochemistry in an attempt to detect a meteoritic component. The results gave no unequivocal evidence of meteoritic material. Nevertheless, the outline of the crater field, evidence of heated material within the craters, and subsurface structure are comparable with known meteorite crater fields.

Right ventricular pacing at various sites and shortened atrioventricular (AV) delay has failed to... more Right ventricular pacing at various sites and shortened atrioventricular (AV) delay has failed to demonstrate a convincing short-term and long-term improvement of left ventricular function. Left-ventricular-based stimulation offers a new therapeutic option for patients with symptomatic congestive heart failure and conduction disturbances, especially of left bundle-branch block configuration. Left ventricular mechanical improvement seems mainly dependent on the pacing site, in addition to optimizing the AV delay. Predominantly retrospective data suggest that pacing the posterolateral free wall results in the greatest hemodynamic improvement.

Radiation and Environmental Biophysics, 2011

An approach is proposed to assess the periods of human skin exposure to solar ultraviolet-A (UV-A... more An approach is proposed to assess the periods of human skin exposure to solar ultraviolet-A (UV-A, 315–400 nm) irradiance in natural conditions that are able to yield doses found to trigger carcinogenesis in laboratory experiments. Weighting functions, adopted to perform such estimate are constructed, allowing for a comparison between environmental and laboratory doses. Furthermore, the impact of stratum corneum (SC) thickness on the studied environmental doses was investigated. Based on laboratory studies, it was found that exposure periods of less than a month, at mid-latitudes, could provide irradiance doses capable of causing tumor formation. The duration of these exposure periods closely depends on the exposure regime, atmospheric conditions and SC thickness. It is believed that the presented evaluations could provide a useful preliminary estimation of the risk associated with environmental UV-A exposure prior to the formulation of the corresponding action spectra and determination of the threshold doses.

Experimental Dermatology, 2006

Background: Ultraviolet (UV)-induced pyrimidine dimers are an early step in skin carcinogenesis,... more Background: Ultraviolet (UV)-induced pyrimidine dimers are an early step in skin carcinogenesis, which is accelerated in the setting of long-term immunosuppression with systemic calcineurin inhibitors. It is not known whether topical application of calcineurin inhibitors exposes to a similar risk.Objective: To assess the formation and clearance of UV-induced dipyrimidine dimers in human epidermis treated with topical pimecrolimus as compared to topical steroid, vehicle and untreated control.Methods: Pretreated buttock skin of 20 human volunteers with (10) or without (10) atopic dermatitis was exposed to two minimal erythema doses (MED) of simulated solar radiation. DNA was extracted from epidermis 1 and 24 h postirradiation. Pyrimidine dimers were visualized by immuno slot blots and quantified by chemoluminescence image analysis.Results: One-hour postirradiation, pimecrolimus-treated epidermis contains less DNA damage as compared to untreated control, but there were no statistically significant differences between pimecrolimus, triamcinolone acetonide and vehicle. Dimer levels at 24 h postirradiation showed no significant differences between different treatments.Conclusion: Treatment with pimecrolimus cream, triamcinolone acetonide cream and vehicle is not associated with increased epidermal DNA damage at 1 and 24 h post-UV exposure.