Performance of an adaptive successive serial-parallel CDMA cancellation scheme in flat Rayleigh fading channels

The performance of a successive concatenated cancellation scheme for code-division multiple-access (CDMA) uplink transmission in cellular mobile radio is presented. Both serial and parallel cancellation stages are employed. The serial cancellation stage is first used to obtain initial data estimates followed by the parallel cancellation stages to enhance the accuracy of the estimates. The performance of this scheme is evaluated via analysis and simulation. In our analysis, we develop a model to consider the impact of wrongly estimating the phase and amplitude of the channel impulse response on the successive concatenated cancellation scheme. Analysis and simulation results in flat Rayleigh fading asynchronous channels with both perfect and nonperfect channel estimation and with perfect ranking confirms the accuracy of our analytical model as well as the significant improvement in performance compared to the conventional single-user matched filter (MF) detection and the stand-alone parallel cancellation schemes. Analytical results also show that the concatenated scheme has the potential to reach the single-user performance bound for a wide range of user base size, up to K = 120 users, with a processing gain of 127 using one serial and three parallel cancellation stages. Finally, we propose a method whereby the receiver adapts with the number of users in order to retain the bit error ratio (BER) performance while decreasing the processing delay

Herbal Remedies for Combating Irradiation: a Green Antiirradiation Approach

Plants play important roles in human life not only as suppliers of oxygen but also as a fundamental resource to sustain the human race on this earthly plane. Plants also play a major role in our nutrition by converting energy from the sun during photosynthesis. In addition, plants have been used extensively in traditional medicine since time immemorial. Information in the biomedical literature has indicated that many natural herbs have been investigated for their efficacy against lethal irradiation. Pharmacological studies by various groups of investigators have shown that natural herbs possess significant radioprotective activity. In view of the immense medicinal importance of natural product based radioprotective agents, this review aims at compiling all currently available information on radioprotective agents from medicinal plants and herbs, especially the evaluation methods and mechanisms of action. In this review we particularly emphasize on ethnomedicinal uses, botany, phytochemistry, mechanisms of action and toxicology. We also describe modern techniques for evaluating herbal samples as radioprotective agents. The usage of herbal remedies for combating lethal irradiation is a green antiirradiation approach for the betterment of human beings without high cost, side effects and toxicity

Can computers be teammates?

This study investigated the claim that humans will readily form team relationships with computers . Drawing from the group dynamic literature in human -human interactions , a laboratory experiment ( n ϭ 56) manipulated identity and interdependence to create team af filiation in a human -computer interaction . The data show that subjects who are told they are interdependent with the computer af filiate with the computer as a team . The data also show that the ef fects of being in a team with a computer are the same as the ef fects of being in a team with another human : subjects in the interdependence conditions perceived the computer to be more similar to themselves , saw themselves as more cooperative , were more open to influence from the computer , thought the information from the computer was of higher quality , found the information from the computer friendlier , and conformed more to the computer's information . Subjects in the identity conditions showed neither team af filiation nor the ef fects of team af filiation

Cost-minimization analysis of oral versus intravenous antibiotic treatment for Klebsiella pneumoniae liver abscess

A cost-minimization analysis was conducted for Klebsiella pneumoniae liver abscess (KLA) patients enrolled in a randomized controlled trial which found oral ciprofloxacin to be non-inferior to intravenous (IV) ceftriaxone in terms of clinical outcomes. Healthcare service utilization and cost data were obtained from medical records and estimated from self-reported patient surveys in a non-inferiority trial of oral ciprofloxacin versus IV ceftriaxone administered to 152 hospitalized adults with KLA in Singapore between November 2013 and October 2017. Total costs were evaluated by category and payer, and compared between oral and IV antibiotic groups over the trial period of 12 weeks. Among the subset of 139 patients for whom cost data were collected, average total cost over 12 weeks was $16,378 (95$14,620-$18,136) for the oral ciprofloxacin group and$20,569 (95% CI, $18,296-$22,842) for the IV ceftriaxone group, largely driven by lower average outpatient costs, as the average number of outpatient visits was halved for the oral ciprofloxacin group. There were no other statistically significant differences, either in inpatient costs or in other informal healthcare costs. Oral ciprofloxacin is less costly than IV ceftriaxone in the treatment of Klebsiella liver abscess, largely driven by reduced outpatient service costs.Trial registration: ClinicalTrials.gov Identifier NCT01723150 (7/11/2012)

Rate of Convergence Towards Semi-Relativistic Hartree Dynamics

We consider the semi-relativistic system of $N$ gravitating Bosons with gravitation constant $G$. The time evolution of the system is described by the relativistic dispersion law, and we assume the mean-field scaling of the interaction where $N \to \infty$ and $G \to 0$ while $GN = \lambda$ fixed. In the super-critical regime of large $\lambda$, we introduce the regularized interaction where the cutoff vanishes as $N \to \infty$. We show that the difference between the many-body semi-relativistic Schr\"{o}dinger dynamics and the corresponding semi-relativistic Hartree dynamics is at most of order $N^{-1}$ for all $\lambda$, i.e., the result covers the sub-critical regime and the super-critical regime. The $N$ dependence of the bound is optimal.Comment: 29 page

Opt-out of Voluntary HIV Testing: A Singapore Hospital's Experience

INTRODUCTION: Since 2008, the Singapore Ministry of Health (MOH) has expanded HIV testing by increasing anonymous HIV test sites, as well as issuing a directive to hospitals to offer routine voluntary opt out inpatient HIV testing. We reviewed this program implemented at the end of 2008 at Tan Tock Seng Hospital (TTSH), the second largest acute care general hospital in Singapore. METHODS AND FINDINGS: From January 2009 to December 2010, all inpatients aged greater or equal than 21 years were screened for HIV unless they declined or were not eligible for screening. We reviewed the implementation of the Opt Out testing policy. There were a total of 93,211 admissions; 41,543 patients were included based on HIV screening program eligibility criteria. Among those included, 79% (n = 32,675) opted out of HIV screening. The overall acceptance rate was 21%. Majority of eligible patients who were tested (63%) were men. The mean age of tested patients was 52 years. The opt out rate was significantly higher among females (OR: 1.5, 95%CI: 1.4-1.6), aged >60 years (OR: 2.3, 95%CI: 2.2-2.4) and Chinese ethnicity (OR: 1.7, 95%CI:1.6-1.8). The false positive rate of the HIV screening test is 0.56%. The proportion of patients with HIV infection among those who underwent HIV screening is 0.18%. All 16 confirmed HIV patients were linked to care. CONCLUSION: The default opt-in rate of inpatient HIV testing was low at Tan Tock Seng Hospital, Singapore. Efforts to address individual HIV risk perception and campaigns against HIV stigma are needed to encourage more individuals to be tested for HIV

Utility of Dutch Lipid Clinic Network Score to Estimate Prevalence of Familial Hypercholestrolemia in Patients with ST-Elevation Myocardial Infarction

Background Hypercholesterolaemia is prevalent in the Malaysian population, and its treatment control rates remain suboptimal1. Familial hypercholesterolemia (FH) is an autosomal dominant condition that leads to accelerated arteriosclerotic cardiovascular disease (ASCVD). The prevalence of FH in the general population worldwide has been postulated to be 1:3132 and 1:100 in the Malaysian community3. It has been proposed that lipid lowering treatment prevents further increase in total cardiovascular risk of FH patients, and this recommendation is extensible for FH patients plus atherosclerotic CAD (coronary artery disease). However, despite its implication in CAD, FH is still an underdiagnosed and undertreated condition2-4. To date, the prevalence of FH in the STEMI (ST-elevation myocardial infarction) population in Malaysia is not studied. Establishing the prevalence of FH among patients with CAD and comparing this with the general population would help future efforts at identifying subjects with FH. Objective We aim to estimate the prevalence of FH in patients with STEMI in Sarawak using Dutch Lipid Clinic Network (DLCN) score. Materials and Methods Patients who were admitted for type-1 STEMI from April 2021 until July 2021 to Pusat Jantung Sarawak were recruited. History taking and physical examination were carried out on-site. FH was screened clinically using DLCN score. Results Out of the recruited patients, 45% of the cohort was clinically categorized into probable/ possible FH without genetic testing. Mean age and low density lipoprotein (LDL) were 52.7 and 3.38mmol/l respectively. Prevalence of premature CAD was 63%. Male gender, smoking, high BMI was the most frequent risk factor observed. Conclusions Prevalence of probable/possible familial hypercholesterolemia in a STEMI cohort using DLCN score is 45%. DLCN score in the STEMI cohort is not related to LDL levels

Coronary artery calcification – distribution, extent and 1-year outcomes in patients with low to intermediate pre-test probability of coronary artery disease.

Background: Coronary artery calcium (CAC) is an established marker to predict major cardiovascular events (MACE), and has incremental value over traditional risk factors (CVRF). CAC is widely available, easily reproducible, and used in nearly all coronary computed tomography angiography (CCTA) assessment protocols for coronary artery disease (CAD). The distribution and extent of CAC, and its prognostic implications in local Malaysian patients with low to intermediate pre-test probability (LI-PTP) of CAD had not been established. Objectives: We aimed to establish the distribution, extent and prognostic implications of CAC in patients without known CAD, but with LI-PTP of CAD, undergoing CCTA for chest pain evaluation. Methods: Clinical information was obtained from consecutive patients who underwent CAC and CCTA examination from January 2020 to January 2021 at a single public access tertiary referral centre. The primary outcomes were the distribution and extent of CAC, and its relationship with MACE at 1 year. Results: Of 499 consecutive patients, 7 were excluded due to high PTP. CAC was present in 172/492 (35%). Within this group, 74/172 (41.3%) had CAC score of 1-100 (mild), 75/172 (42.4%) had a CAC of 101- 400 (moderate), 23/172 (13.4%) had CAC of >400 (high). 136 had suspected significant CAD and was offered conventional coronary angiography (CCA). 91/492 underwent CCA, and 38 were found to have significant CAD. Of those found to have significant CAD, 7/38 (18.4%) had CAC of zero, 8/38 (21.1%) had mild CAC, 12/38 (31.6%) moderate, and 11/38 (30%) high CAC. Severe CAC was associated with a higher rate of revascularization 11/23 (47.8%), compared to those with zero 7/320 (2.2%), mild 8/74 (10.8%) and moderate 12/75 (16%) CAC. Predictors of high CAC were age, male gender, and presence of cardiovascular disease risk factors. Of the 492 patients, 230 patients completed 1 year follow-up, and from this, 1 patient had a MACE. Conclusion In patients with LI-PTP risk of CAD, CAC was seen in approximately one third of our cohort. In the group with high CAC, a higher proportion required coronary revascularization, but MACE remained low at 1 year

Prevalence of Acid alpha-Glucosidase (GAA) Pseudodefiency Allele and It’s Clinical Significance Among Patients with Cardiomyopathy

Background: Pompe disease is an autosomal recessive lysosomal storage disorder caused by deficiency of lysosomal acid alpha-glucosidase (GAA) activity, leading to the progressive accumulation of glycogen in lysosomes of the skeletal and cardiac muscles. An alpha-glucosidase (GAA) pseudodeficiency allele is a change in the GAA gene sequence that results in GAA enzyme activity reduction, but does not cause Pompe disease. In Japan and Taiwan, there is high prevalence of pseudodeficiency allele (c.1725G>A and c.2065G>A) detected from their newborn screening. We observed similar prevalence of pseudodeficiency allele among our patients who had genetic test performed for suspected hereditary cardiomyopathy. Objectives: To report the prevalence of GAA pseudodeficiency allele, and to ascertain its clinical significance among patients with cardiomyopathy. Methods: The clinical data of the patients with GAA mutations were retrieved. Patients were called back for neurological examination, lung function test, measurement of creatine kinase (CK) level and dried-blood-spot for GAA enzymatic activity. Results: From January to December 2021, 33 patients underwent genetic testing. 23 out of the 33 genetic analyses included GAA mutation. 9 (39.13%) out of 23 were tested positive for pseudodeficiency allele. Their median age was 53 years (range 29-82), 44.4% were males with equal ethnic distribution (33.3% Malay, 33.3% Chinese, 33.3% Dayaks). All were heterozygous for the pseudodeficiency allele: 5 (55.6%) with c.[1726A; 2065A] allele, the other 4 (44.4%) c.2065G>A. The underlying cardiomyopathy phenotypes were hypertrophic (44.4%), transthyretin amyloid (22.2%), hypertensive (22.2%) and Fabry (11.1%). 1 patient (11.1%) with transthyretin amyloid cardiomyopathy died of advanced heart failure at age 79 years. 1 patient had mild motor weakness of the limbs attributable to thyrotoxicosis, while the other 7 patients had normal skeletal motor function. Their median predicted forced vital capacity was 87.5% (range 76-103), median CK level was 103 U/L (range 39-297) and median GAA activity was 4.8 micromol/l/h (range 3.2-9.2) [normal > 2.0]. Conclusion: The prevalence of GAA pseudodeficiency allele among patients with cardiomyopathy is 39.13%. None of the patients exhibit significant muscle weakness or respiratory insufficiency despite low normal enzymatic activity. Whether the presence of pseudodeficiency allele affects the prognosis of the underlying cardiomyopathy remains uncertain

Coronary Computed Tomography Angiography as part of initial strategy, in assessment of patients with chest pain – clinical experience and 1 year prognosis.

Background: Coronary computed tomography angiography (CCTA) has been showed to have high specificity and sensitivity for detecting coronary artery disease (CAD). In Malaysia, national guidelines state that CCTA may be used in low- to intermediate pre-test probability (LI-PTP) of CAD, who have an equivocal functional test result, and who are asymptomatic or mildly symptomatic with good exercise capacity. Recent evidence suggested a ‘CCTA-first’ strategy in the evaluation of a patient with chest pain could provide prognostic benefits. Prognostic benefits of adopting this strategy in Malaysia has not been well studied. Objectives: We aimed to evaluate 12-month clinical outcomes of patients with LI-PTP, using the CCTA as an initial strategy, or as part of the work-up for, chest pain assessment. Methods: Consecutive patients who underwent CCTA examination from January 2020 to January 2021 were enrolled. Clinical information was then extracted. Primary outcome was defined as presence of stenosis of >50% in a major epicardial coronary artery; and secondary outcome defined as a composite of all-cause mortality, non-fatal myocardial infarction (MI) and coronary revascularisation. Results: Among the initial 499 patients, 7 were excluded as they were high in PTP. The mean PTP was 47.1±26.3. Baseline characteristics were available in 300 patients. The mean age was 53.5±11.4 years, 59.3% were male, 18.6% were diabetic, 71.2% had hypertension, and 50.8% had hypercholestrolaemia. 1.9% had an equivocal functional test for ischaemia. Of the 492 LI-PTP patients who underwent CCTA, 136 patients were suspected to have significant CAD, and recommended conventional coronary angiography (CCA). Of these, 91 patients underwent CCA. From this group 38 were found to have significant CAD which warranted revascularisation – 32 by percutaneous coronary intervention (PCI) and 6 referred for coronary artery bypass surgery (CABG). Therefore, utilising this strategy, 7.7% (38/492) of patients met the primary outcome. Of the original cohort of 492 LI-PTP patients, only 230 completed 1 year follow up, and from this, one patient met the secondary outcome. Conclusion Incorporation of CCTA into contemporary chest pain evaluation identified significant number of patients with significant CAD and was also associated with a low cardiac event rate at 1 year follow-up