Seven naphtho-γ-pyrones from the marine-derived fungus Alternaria alternata: structure elucidation and biological properties

Eight bioactive pyrone derivatives were identified from the culture of Alternaria alternata strain D2006, isolated from the marine soft coral Denderonephthya hemprichi, which was selected as its profound antimicrobial activities. The compounds were assigned as pyrophen (1), rubrofusarin B (2), fonsecin (3), and fonsecin B (5) beside to the four dimeric naphtho-γ-pyrones; aurasperone A (6), aurasperone B (7), aurasperone C (8), and aurasperone F (9). Structures of the isolated compounds were identified on the basis of 1D and 2D NMR spectroscopy and mass (EI, ESI, HRESI) data, and by comparison with the literature. Configuration of the four dimeric naphtho-γ-pyrones 6-9 was analyzed by CD spectra, exhibiting an identical stereochemistry

Lightweight Mutual Authentication Protocol for Low Cost RFID Tags

Radio Frequency Identification (RFID) technology one of the most promising technologies in the field of ubiquitous computing. Indeed, RFID technology may well replace barcode technology. Although it offers many advantages over other identification systems, there are also associated security risks that are not easy to be addressed. When designing a real lightweight authentication protocol for low cost RFID tags, a number of challenges arise due to the extremely limited computational, storage and communication abilities of Low-cost RFID tags. This paper proposes a real mutual authentication protocol for low cost RFID tags. The proposed protocol prevents passive attacks as active attacks are discounted when designing a protocol to meet the requirements of low cost RFID tags. However the implementation of the protocol meets the limited abilities of low cost RFID tags.Comment: 11 Pages, IJNS

On improving assessment of in-hospital mortality and ICU admission in community-acquired pneumonia patients using the eCURB

AbstractBackgroundAssessment of severity of the disease in community-acquired pneumonia (CAP) is very important to decide the site of care. The conventional CURB-65 score is composed of five separate elements namely, Confusion, Uremia, Respiratory rate, BP, and age ⩾65years. These elements could be calculated electronically. The electronic CURB (eCURB) utilizes the 5 CURB-65 data elements as continuous, weighted variables. The aim of this study was to evaluate the performance of eCURB elements in predicting in-hospital mortality and ICU admission in comparison to the conventional CURB-65.Material and methodsThis study was conducted upon 134 adult patients diagnosed as CAP and confirmed by radiographic findings, admitted to chest department, Assiut University Hospital, Egypt. The CURB-65 elements were retrospectively extracted from the medical records. The eCURB variables were introduced to electronically calculate the risk using the Excel appendix model (provided by Prof. Nanthan Dean, University of Utah, Salt Lake city, USA) and its predictive values and area under the receiver-operating characteristic (ROC) curve were compared with the conventional CURB-65 in predicting in-hospital mortality and the need for ICU admission.ResultsThe study revealed that the conventional CURB-65 score could predict in-hospital mortality with an area under the curve (AUC) of 0.81 and the need for ICU admission with an AUC of 0.87. Using the eCURB-65 elements proved to be superior to the conventional CURB-65 in predicting in-hospital mortality with cut off point >7.5 and an AUC of 0.83 (P<0.0001). Also, eCURB was better than conventional CURB-65 in predicting ICU admission with cut off point >3.8 and an AUC of 0.89 (P<0.0001).ConclusionsUsing the eCURB proved to be a valuable tool in predicting in-hospital mortality and ICU admission in patients with CAP with a significant superiority over conventional CURB-65 in both variables. Further prospective studies on a larger cohort are recommended

SYNTHESIS AND X-RAY CRYSTALLOGRAPHY OF 2,4,6-TRIMETHYL-1,4-DIHYDRO-PYRIDINE-3,5-DICARBOXYLIC ACID DIETHYL ESTER

The biologically active 2,4,6-trimethyl-1,4-dihydro-pyridine-3,5-dicarboxylic acid diethyl ester has been prepared and characterized by X-ray crystallography. The 1,4-dihydro-pyridine ring is in a flattened boat form, with atoms C3, and N1 being the bow and stern of the boat. Atoms C3 and N1 being 0.1346(12)A and 0.0970(12)A above the mean plane of the 1,4-dihydro-pyridine ring. One of the ethyl ester groups were found to be disordered in two positions at occupancies of 0.517 (19) and 0.483 (19) respectively. There are four molecules of 2,4,6-trimethyl-1,4-dihydro-pyridine-3,5-dicarboxylic acid diethyl ester, in the unit cell. Inter­molecular N—H···O hydrogen bonding inter­actions were observed in the crystal lattice which connected the molecules into chain running along b-axis

Hospital quality measures and their determinants among HIV/AIDS hospitalizations in Portugal

Resumo A taxa de reinternamento hospitalar aos 30 dias e o tempo de internamento hospitalar têm sido referidos como importantes indicadores para melhorar a qualidade e reduzir os custos hospitalares. No entanto, apesar de se tratarem de excelentes métodos de avaliação de desempenho hospitalar, ainda existem poucos estudos científicos sobre os fatores determinantes destes indicadores, especialmente no que diz respeito à avaliação de internamentos em doentes com VIH/SIDA em Portugal. O VIH continua a ser, em Portugal, um e problema de saúde pública e a incidência e prevalência do VIH estão entre as mais elevadas da Europa. Os internamentos de doentes com VIH/SIDA continuam a colocar desafios consideráveis ao sistema nacional de saúde português. Acresce que as hospitalizações relacionadas com o VIH/SIDA em Portugal são das mais caras da Europa, colocando o VIH/SIDA como a segunda maior Categoria de Diagnóstico Principal. Esta tese tem como objetivo analisar medidas de qualidade hospitalar e seus determinantes nos internamentos por VIH/SIDA em hospitais públicos portugueses (Portugal Continental). Mais especificamente, estimar a taxa de reinternamento aos 30 dias e do tempo de internamento por VIH/SIDA ao longo do tempo e fatores associados. Para cumprir estes objetivos, foram realizados quatro estudos (I - IV) com dados obtidos junto da Administração do Sistema Central de Saúde (ACSS) de Portugal, e seguindo diferentes desenhos. O Estudo I faz uma revisão da carga económica dos internamentos considerando as hospitalizações por VIH/SIDA em Portugal, explicando a importância da implementação de indicadores de qualidade para medir o desempenho dos hospitais, bem como possíveis formas de estudar os fatores que podem afetar esses indicadores de qualidade. O Estudo II enfatizou o papel crucial que as medidas de qualidade podem desempenhar na mitigação dos encargos financeiros impostos pela nova pandemia de doença do coronavírus (COVID-19) no sistema de saúde. Um estudo longitudinal multinível de base populacional foi conduzido no estudo III para estimar as taxas de reinternamento hospitalar aos 30 dias nas hospitalizações por VIH em Portugal. Além disso, este estudo teve como objetivo descrever e analisar os fatores associados aos reinternamentos aos 30 dias em doentes com VIH em Portugal, através da aplicação de modelos de regressão logística ordinária e multinível. No estudo IV, foi realizada uma análise de regressão de contagem com efeitos aleatórios para ilustrar técnicas estatísticas uteis na análise de dados de contagem usando dados longitudinais do tempo de internamento em hospitalizações por VIH em Portugal. Várias estratégias foram aplicadas para selecionar o modelo que melhor se ajustava, incluindo o modelo de regressão de Poisson, o modelo de regressão binomial negativo inflacionado, o modelo de regressão binomial negativo e o modelo de regressão binomial negativo inflacionado de zero. Um termo de efeitos aleatórios foi incorporado ao modelo binomial negativo para examinar a dependência entre as observações dentro do mesmo hospital. Uma análise multinível foi realizada para avaliar o efeito das co variáveis no tempo de internamento. Os reinternamentos aos 30 dias totalizaram 4914 hospitalizações [13,2%, intervalo de confiança de 95% (IC): 12,9% −13,6%]. Internamentos que incluíram alta contra orientação médica [odds ratio (OR) = 1,18, IC 95%: 1,01-1,39], admissões programadas (OR = 1,71, IC 95%: 1,58-1,85) e infeção por tuberculose (OR = 1,20, 95 % CI: 1,05-1,38) tiveram uma maior chance de reinternamento aos 30 dias. Em contraste, as hospitalizações entre mulheres (OR = 0,87, IC 95%: 0,81–0,94), que incluíram uma transferência para outra unidade (OR = 0,78, IC 95%: 0,67–0,91) e ter uma instituição financeira responsável (OR = 0,63 , 95% CI: 0,55-0,72) tiveram uma menor chance de reinternamento aos 30 dias. Os internamentos associados a maior número de diagnósticos, idade avançada ou internamentos durante o período de crise económica tiveram um efeito positivo na probabilidade de reinternamento aos 30 dias, enquanto que tendência oposta foi observada para internamentos com maior número de procedimentos. Existem diferenças significativas entre a qualidade dos diferentes hospitais, mesmo ajustando para outros fatores. O tempo mediano de internamento hospitalar foi de 11 dias (intervalo interquartil: 6-22). As comparações entre os diversos modelos de contagem sugerem que os modelos binomiais negativos com efeitos aleatórios forneceram o melhor ajuste os dados observados. As admissões entre homens ou associadas à infeção por tuberculose, pneumocisto, citomegalovírus, candidíase, toxoplasmose ou doença por micobactéria aumentam significativamente o tempo de internamento estimado. Estimou-se igualmente que um maior número de diagnósticos ou procedimentos está relacionado com um tempo de internamento significativamente maior. A estimação dos efeitos aleatórios para cada hospital revelou diferenças na qualidade entre os hospitais incluídos no estudo, mesmo ajustando aos outros fatores.Esta tese contribui contribuiu para o aprofundamento dos fatores relacionados com a carga económica do VIH/SIDA em Portugal. As conclusões sugerem a importância de integrar medidas de qualidade, baseadas no tempo de internamento hospitalar e taxa de reinternamento como um método de avaliação do desempenho dos hospitais, nomeadamente num contexto de recursos escassos. Os resultados desta tese são suportados por uma grande base de dados que representa todas os internamentos nos hospitais públicos de Portugal Continental por VIH/SIDA; estes achados também podem ajudar a definir a base para novas abordagens que tenham em linha de conta pacientes com alto risco de reinternamento precoce ou tempo de internamento prolongado. Os modelos e especificações estatísticas descritas nesta tese podem ser replicados e aplicados a outras doenças e contextos.Abstract Thirty-day readmission rate, and length of hospital stay have drawn attention as methods for enhancing the quality of care and reducing associated costs. However, despite being optimal methods for assessing hospital’s performance, there remains a scarcity of research pertaining to the factors that can influence these quality indicators, especially when it comes to assessing hospitalizations among HIV/AIDS patients in Portugal. In Portugal, HIV continues to be a major public health concern and HIV incidence and prevalence are among the highest in Europe. Admissions among HIV/AIDS patients still pose considerable challenges to the Portuguese national health system. Moreover, hospitalizations related to HIV/AIDS in Portugal are some of the most expensive, placing HIV/AIDS as the second greatest Major Diagnostic Category. This thesis aims to assess hospital quality measures and their determinants among HIV/AIDS hospitalizations in Portuguese public hospitals. The work also aims to identify variation in thirty-day readmission rate and length of stay among HIV/AIDS admission in public Portuguese hospitals. To accomplish these objectives, four studies (I – IV) were performed using data obtained from the Portuguese Central Health System Administration (ACSS), and following different designs. Studies I reviewed the economic burden of hospitalizations among HIV/AIDS hospitalizations in Portugal, explaining the importance of implementing quality indicators to measure the performance of hospitals, as well as possible ways to study the factors that can affect these quality indicators. Study II emphasized the crucial role quality measures can play in mitigating the financial burden imposed by the novel coronavirus disease (COVID-19) pandemic on the health system. A longitudinal multilevel population-based study was conducted in study III to estimate the 30-day hospital readmission rates among HIV hospitalizations in Portugal. Moreover, this study aimed to describe and analyze factors associated with subsequent 30-day readmission among HIV patients in Portugal by applying ordinary and multilevel logistic regression models. In study IV, a count regression analysis using a random-effects model was conducted to illustrate statistical techniques for analysing count data using longitudinal predictors of length of stay among HIV hospitalizations in Portugal. Several strategies were applied to select the best count fit model including the Poisson regression model, the zero-inflated Poisson, the negative binomial regression model, and the zero-inflated negative binomial regression model. A random hospital effects term was incorporated into the negative binomial model to examine the dependence between observations within the same hospital. A multivariable analysis was performed to assess the effect of covariates on length of stay. A total of 4914 [13.2%, 95% confidence interval (CI): 12.9%−13.6%] hospitalizations had a subsequent 30-day readmission. Hospitalizations that included discharge against medical advice [odds ratio (OR) = 1.18, 95% CI: 1.01–1.39], scheduled admissions (OR = 1.71, 95% CI: 1.58–1.85), and tuberculosis infection (OR = 1.20, 95% CI: 1.05–1.38) exhibited a higher odds of hospitalizations with subsequent 30-day readmission. In contrast, hospitalizations among females (OR = 0.87, 95% CI: 0.81–0.94), that included a transfer to another facility (OR = 0.78, 95% CI: 0.67–0.91) and having a responsible financial institution (OR = 0.63, 95% CI: 0.55–0.72) exhibited a lower odds of hospitalizations with subsequent 30-day readmission. Hospitalizations associated with a higher number of diagnoses, older ages, or hospitalizations during the economic crisis showed an increasing trend of 30-day readmission, whereas an opposite trend was observed for hospitalizations with a higher number of procedures. Significant differences exist between hospital quality, even after adjusting for other factors. The median length of stay in the study was 11 days (interquartile range: 6-22). Statistical comparisons across the count models revealed that the random-effects negative binomial models provided the best fit with observed data. Admissions among males, or admissions associated with tuberculosis infection, pneumocystis, cytomegalovirus, candidiasis, toxoplasmosis or mycobacterium disease exhibit a high significant increase in length of stay. Perfect trends were observed in which a higher number of diagnoses or procedures lead to a significantly longer length of stay. The random-effects term included in the model refers to unexplained factors specific to each hospital and revealed obvious differences in quality across the hospitals included in the study. This thesis contributes to attempts to reduce the economic burden of HIV/AIDS in Portugal and point to the importance of integrating quality measures such as a method for evaluating the performance of hospitals in light of limited resources. Findings from this thesis are supported by a large database that represents all Portuguese public HIV/AIDS admissions and can help develop a national health policy to avoid unnecessary readmissions or delayed discharges. These findings can also set the basis for new insights that can focus on patients at high risk of early readmission or prolonged length of stay. The models and statistical frameworks described in this thesis can be replicated and applied to other diseases and settings

Value of non-contrast CT examination of the urinary tract (stone protocol) in the detection of incidental findings and its impact upon the management

AbstractBackgroundUrolithiasis is one of the most common urinary tract diseases worldwide, with a wide range of affected age groups. Non-contrast CT examination of the urinary tract is the gold-standard examination for detection and characterization of urinary tract stones, with great impact upon the choice of method of management. Aside from detection of stones, non-contrast CT examination of the abdomen and pelvis also offers a valuable overlook upon the other abdominal organs, pathologies of which may simulate a stone disease, or accompany stone disease and can be detected incidentally, which may shift management plan dramatically.Aim of workTo demonstrate the use of non-contrast CT examinations (stone protocol) in the detection of abdominal pathologies other than stones, whether or not simulating the clinical picture of urolithiasis, and its impact upon patient management.Patients and methodsAssessment of the non-contrast examinations of the urinary tract of patients referred for suspected stone urolithiasis recording any incidental finding and follow-up of the impact of these incidental findings upon the management delivered to the patient.ResultsA total of 719 examinations were performed, of which 334 had urinary tract stones only, 211 had incidental finding beside urinary tract stones, 170 had an incidental finding with no urinary tract stones, and four patients had neither stones nor incidental findings. A total number of 381 patients had incidental findings, 198 (47%) of which had an impact upon the management.ConclusionNon-contrast CT examination of the urinary tract (stone protocol) is a valuable tool in the detection of incidental findings which may simulate, or coincide with urolithiasis and it has a significant impact upon the management of the patients

Normal testicular tissue elasticity by sonoelastography in correlation with age

AbstractPurposeThis research aimed to study the correlation between the normal testicular tissue elasticity as detected by real time sonoelastography with the age.Materials and methodsThe study was conducted upon 63 adult healthy volunteers. Each volunteer was subjected to real time sonoelastography measuring the strain ratio of testicular tissues and their elasticity scores.ResultStrain ratios of the examined testes ranged from 0.27 to 0.38, with a mean strain of 0.33 and a standard deviation of 0.03. Elasticity score of the examined testes included ES1 in 62 testes (49%), ES2 in 58 testes (46%) and ES3 in 6 testes (5%). No ES4 or ES5 was elicited in this group. High negative correlation is found between the age and both the testicular volume and the strain ratio, while there is no correlation between age and the elasticity score of testes.ConclusionNormal testicular tissues as studies by sonoelastography show strong correlation between the age and the testicular volume as well as the strain ratio

Behavior of Power System Equilibrium Points in Dynamic Available Transfer Capability Calculation

Available Transfer Capability (ATC) is of fundamental importance in electric power system planning and operation. The calculation of firm ATC in a power market environment is carried out based on day-ahead market dispatch with a set of security constraints. Incorporating dynamic security constraints into the ATC calculation not only renders a heavier burden on the computational approach, but also manifests complex system behavior in the neighborhood of its equilibrium points. This paper specifically highlights exotic system characteristics encountered during dynamic ATC calculation. The problem of ATC calculation is modeled as a nonlinear mathematical programming problem to maximize the power transfer subject to system technical and operating constraints. The dynamic ATC constraints are represented via the quadratic approximation of the stable manifold of the controlling unstable equilibrium point (UEP). A case study on the IEEE WECC 3- machine, 9-bus power system is presented and analyzed

Mansouramycins E–G, Cytotoxic Isoquinolinequinones from Marine Streptomycetes

Chemical investigation of the ethyl acetate extract from the marine-derived Streptomyces sp. isolate B1848 resulted in three new isoquinolinequinone derivatives, the mansouramycins E–G (1a–3a), in addition to the previously reported mansouramycins A (5) and D (6). Their structures were elucidated by computer-assisted interpretation of 1D and 2D NMR spectra, high-resolution mass spectrometry, and by comparison with related compounds. Cytotoxicity profiling of the mansouramycins in a panel of up to 36 tumor cell lines indicated a significant cytotoxicity and good tumor selectivity for mansouramycin F (2a), while the activity profile of E (1a) was less attractive