Solar photovoltaic (PV) energy has shown significant expansion on the installed capacity over the last years. Most of its power systems are installed on rooftops, integrated into buildings. ...Considering the fast development of PV plants, it has becoming even more critical to understand the performance and reliability of such systems. One of the most common problems faced in PV plants occurs when solar cells receive non-uniform irradiance or partially shaded. The consequences of shading generally are prevented by bypass diodes. A significant number of studies and technical reports have been published as of today, based on extensive experience from research and field feedbacks. However, such material has not been cataloged or analyzed from a perspective of the technological evolution of bypass diodes devices. This paper presents a comprehensive review and highlights recent advances, ongoing research, and prospects, as reported in the literature, on bypass diode application on photovoltaic modules. First, it outlines the shading effect and hotspot problem on PV modules. Following, it explains bypass diodes’ working principle, as well as discusses how such devices can impact power output and PV modules’ reliability. Then, it gives a thorough review of recently published research, as well as the state of the art in the field. In conclusion, it makes a discussion on the overview and challenges to bypass diode as a mitigation technique.
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) allows a fast and reliable bacterial identification from culture plates. Direct analysis of clinical ...samples may increase its usefulness in samples in which a fast identification of microorganisms can guide empirical treatment, such as blood cultures (BC). Three hundred and thirty BC, reported as positive by the automated BC incubation device, were processed by conventional methods for BC processing, and by a fast method based on direct MALDI-TOF MS. Three hundred and eighteen of them yield growth on culture plates, and 12 were false positive. The MALDI-TOF MS-based method reported that no peaks were found, or the absence of a reliable identification profile, in all these false positive BC. No mixed cultures were found. Among these 318 BC, we isolated 61 Gram-negatives (GN), 239 Gram-positives (GP) and 18 fungi. Microorganism identifications in GN were coincident with conventional identification, at the species level, in 83.3% of BC and, at the genus level, in 96.6%. In GP, identifications were coincident with conventional identification in 31.8% of BC at the species level, and in 64.8% at the genus level. Fungaemia was not reliably detected by MALDI-TOF. In 18 BC positive for Candida species (eight C. albicans, nine C. parapsilosis and one C. tropicalis), no microorganisms were identified at the species level, and only one (5.6%) was detected at the genus level. The results of the present study show that this fast, MALDI-TOF MS-based method allows bacterial identification directly from presumptively positive BC in a short time (<30 min), with a high accuracy, especially when GN bacteria are involved.
The continuous growth of aquaculture places a growing demand on alternative sources of fish oil (FO). Certain microorganisms provide a sustainable replacement for FO due to their content of EPA and ...DHA, which are essential for fish health. Appreciable evidence shows that changes in feeding sources may alter the nutritional components of salmon; however, the influence of diets on lipid species remains unclear. In this study, the identification and semi-quantification of lipid molecular species in salmon muscle during feeding with a microbial oil (MO) were carried out by focusing on triacylglycerol (TAG) and diacyl-phospholipid using shotgun-based mass spectrometry analysis. DHA in the MO diet was efficiently incorporated into phospholipid structures on feeding, followed by accumulation in salmon muscle. The MO diet elevated the level of certain EPA-containing TAGs, such as TAG C52:5 (16:0_16:0_20:5) and TAG C54:6 (16:0_18:1_20:5), indicating that the MO diet may be an excellent source for enhancement of the abundance of ω3 lipids. Further, prostaglandins (PGs) PGE2 and PGF3α were identified and quantified for the first time in salmonid tissue.
Summary
The novel Structural Chemical Analyser (hyphenated Raman spectroscopy and scanning electron microscopy equipped with an X‐ray detector) is gaining popularity since it allows 3‐D morphological ...studies and elemental, molecular, structural and electronic analyses of a single complex micro‐sized sample without transfer between instruments. However, its full potential remains unexploited in painting heritage where simultaneous identification of inorganic and organic materials in paintings is critically yet unresolved. Despite benefits and drawbacks shown in literature, new challenges have to be faced analysing multifaceted paint specimens. SEM−Structural Chemical Analyser systems differ since they are fabricated ad hoc by request. As configuration influences the procedure to optimize analyses, likewise analytical protocols have to be designed ad hoc. This paper deals with the optimization of the analytical procedure of a Variable Pressure Field Emission scanning electron microscopy equipped with an X‐ray detector Raman spectroscopy system to analyse historical paint samples. We address essential parameters, technical challenges and limitations raised from analysing paint stratigraphies, archaeological samples and loose pigments. We show that accurate data interpretation requires comprehensive knowledge of factors affecting Raman spectra. We tackled: (i) the in‐FESEM−Raman spectroscopy analytical sequence, (ii) correlations between FESEM and Structural Chemical Analyser/laser analytical position, (iii) Raman signal intensity under different VP‐FESEM vacuum modes, (iv) carbon deposition on samples under FESEM low‐vacuum mode, (v) crystal nature and morphology, (vi) depth of focus and (vii) surface‐enhanced Raman scattering effect. We recommend careful planning of analysis strategies prior to research which, although time consuming, guarantees reliable results. The ultimate goal of this paper is to help to guide future users of a FESEM‐Structural Chemical Analyser system in order to increase applications.
Lay description
The Structural Chemical Analyser (SCA) technique combines Raman spectroscopy and scanning electron microscopy equipped with an X‐ray detector in a hyphenated instrument: the SEM−SCA system. This novel technique enables an in situ 3‐D morphological and elemental characterization delivered by scanning electron microscopy equipped with an X‐ray detector, and molecular, structural and physical information supplied by Raman spectroscopy on the same sample without moving it between instruments. Although scanning electron microscopy equipped with an X‐ray detector is not suited for analysing organic compounds, which limits their applications towards organic chemistry and life sciences, Raman spectroscopy is able to identify both inorganic and organic compounds. Applying SEM−SCA restrictions of the sequential use of scanning electron microscopy equipped with an X‐ray detector and Raman spectroscopy such as correlation of analysed spots are overcome. Indeed analysis of the exact same area using different instruments has been an aspect largely demanded by the research community dedicated to the characterization of a wide range of materials. Consequentially this unique technique opens new insight to characterize at micro‐ and nanometre scale complex samples from diverse fields such as life science, geoscience or heritage science. However, new challenges have to be faced using SEM−SCA since it displays drawbacks which are different from those found using the two standalone techniques. Moreover, problems have to be resolved specifically for each particular SEM−SCA system since each one is fabricated ad hoc by request.
Until now samples with relatively simple composition, i.e. with purely organic or purely inorganic construction, such as bacteria, metals or mineral particles have been analysed.
Biocrystals (pearls) have been studied as well, although only the inorganic fraction was analysed. Likewise, studies conducted on pigments and wall paintings (CaCO3 is the binding media) showed only results of the mineral phases. The procedure to obtain good in‐SEM Raman spectra is particularly challenging and occasionally no Raman signals are registered on samples. Hence it seems obvious that the analytical process needs supplemental optimization. This is particularly true when analysing historical paintings where closely mixed inorganic pigments and/or organic pigments and binders are present (in multilayers) in the same sample (prepared as cross‐section). Indeed simultaneous identification of inorganic and organic materials in paintings is critically yet unresolved. In this paper we present the optimization of a variable‐pressure FESEM‐EDX−SCA analytical procedure to acquire the best analyses of historical polychromes from the Alhambra monument (Granada, Spain), archaeological samples and loose pigments. To this end we address key parameters, technical challenges and limitations of the system and discuss problems that are both challenging and clearly time consuming.
Summary
The efficacy of treatment for hepatitis C genotype 1 infection has significantly improved with the introduction of first‐generation protease inhibitors. However, there remains a need for ...effective treatments for patients infected with other genotypes, for nonresponders and patients unsuitable for interferon. Sofosbuvir is the first nucleotide polymerase inhibitor with pan‐genotypic activity. Sofosbuvir‐based regimens have resulted in >90% sustained virological response across treatment‐naïve genotype 1–6 patients in five phase III clinical trials of sofosbuvir administered with ribavirin or pegylated interferon and ribavirin. This analysis evaluates the cost‐effectiveness of sofosbuvir within the current licensed indication, for genotype 1–6 in the UK. A Markov model followed a cohort of 10 000 patients over lifetime, with approximately 20% initiating treatment for compensated cirrhosis. Sofosbuvir‐regimens were compared to telaprevir, boceprevir, pegylated interferon and ribavirin, or no treatment. Costs and outcomes were discounted at 3.5%. The cost perspective utilized costs applicable to the National Health Service in the UK. Sofosbuvir proved to be cost‐effective in most patient populations with incremental cost‐effectiveness ratios (ICERs) at £11 836/QALY and £7292/QALY against telaprevir and boceprevir, respectively. In genotype 3, sofosbuvir had a weighted ICER of £18 761/QALY. Sofosbuvir‐based regimens are a cost‐effective option for the majority of hepatitis C‐infected patients in the United Kingdom although the incremental cost‐effectiveness varies by genotype and regimen. Sofosbuvir and ribavirin is an alternative regimen for patients unsuitable for interferon.
Summary
Background
The associations between clinical efficacy and infusion reactions with anti‐TNF‐α drug levels and the presence of antibodies against the drug have been described. However, the ...clinical utility of these tests in routine clinical practice remains unclear.
Aims
To examine the clinical significance of the development of antibodies against anti‐TNF‐α drugs and the relationship between the efficacy of these drugs and their serum levels. We also studied the clinical utility of testing for anti‐TNF‐α antibodies and measuring drug serum levels to optimise treatment of patients with inflammatory bowel disease (IBD) receiving these agents.
Methods
A systematic review was undertaken based on electronic searches of the PubMed database from the earliest record to February 2012. The reference lists of all relevant articles and s from meetings were also consulted.
Results
We observed a close relationship between trough levels of anti‐TNF‐α drug and maintenance of response to these drugs. The role of antibodies in loss of response seems to be limited to their effect favouring the clearance of the drug. The risk of infusion reactions, but not of delayed hypersensitivity reactions, is higher in patients with antibodies against the anti‐TNF‐α drug. Testing anti‐TNF‐α drug and antibody levels, together with clinical and endoscopic or radiological assessment, seems useful when attempting to optimise therapy and prevent inappropriate management of IBD patients.
Conclusion
Measurement of serum anti‐TNF‐α trough levels and antibody titres could prove useful in therapeutic drug monitoring in IBD patients treated with anti‐TNF‐α agents.
Classic and intelligent techniques aim to locate and track the maximum power point of photovoltaic (PV) systems, such as perturb and observe (P&O), fuzzy logic (FL), artificial neural networks ...(ANNs), and adaptive neuro-fuzzy inference systems (ANFISs). This paper proposes and compares three intelligent algorithms for maximum power point tracking (MPPT) control, specifically fuzzy, ANN, and ANFIS. The modeling of a single-diode equivalent circuit-based 3 kWp PV plant was developed and validated to achieve this purpose. Then, the MPPT techniques were designed and applied to control the buck–boost converter’s switching device of the PV plant. All three methods use the ambient conditions as input variables: solar irradiance and ambient temperature. The proposed methodology comprises the study of the dynamic response for tracking the maximum power point and the power generated of the PV systems, and it was compared to the classic P&O technique under varying ambient conditions. We observed that the intelligent techniques outperformed the classic P&O method in tracking speed, tracking accuracy, and reducing oscillation around the maximum power point (MPP). The ANN technique was the better control algorithm in energy gain, managing to recover up to 9.9% power.
The aim of this research was to investigate some of the physical and mechanical properties of concrete mixed under laboratory conditions, where different proportions of coarse aggregate materials ...were substituted by porcelain from sanitary installations. The results of the tests show that the concrete produced has the same mechanical characteristics as conventional concrete, thus opening a door to selective recycling of sanitary porcelain and its use in the production of concrete.
Introduction
Coronavirus disease (COVID-19) has been associated with the development mental and behavioural symptoms and psychiatric disorders. This association is stronger in severe cases of the ...disease and in those needing inpatient treatment, particularly in intensive care units (ICU).
Objectives
To determine the incidence of psychiatric disorders in a Portuguese hospital-based sample of patients with COVID-19. To describe relevant demographic and clinical data.
Methods
We reviewed all COVID-19 inpatients assessed by liaison psychiatry at our hospital between April and September 2020. Patients admitted due to a psychiatric disorder were excluded from the analysis. We reviewed medical records and retrieved relevant clinical data. ICD-10 was used to classify diagnoses.
Results
We identified 36 cases with a mean age of 62.64 years-old (SD 19.23). The most common disorder was delirium, which occurred in 41.7% of our sample (15 patients), followed by adjustment disorder (22.2%, n=8), and depressive episode (16.7%, n=8). Most patients had no personal (61.1%, n=22) nor family (75%, n=27) history of a psychiatric disorder. Mean length of admission was 36.89 days (SD 28.91). Seventeen cases (47.22%) had at least one risk factor for severe COVID-19 disease and 14 (38.89%) were admitted at some point to the ICU.
Conclusions
In our sample, delirium was the main cause for mental or behavioural symptoms in COVID-19 patients. However, we observed a wide array of presentations in our center. A larger sample would allow to better characterize this often-overlooked symptoms and identify risk factors to psychiatric syndromes.
Disclosure
No significant relationships.
To investigate the epidemiological characteristics, clinic-pathological findings and recent use of substances of abuse and prescribed drugs in sexual activity-related sudden death (SArSD).
...Multicenter population-based study on forensic autopsies conducted in 27 provinces of Spain over 12 years (2010-2021).
Out of 18046 autopsied natural deaths, 64 cases (0.35 %) of SArSD were investigated (87 % males). Women were younger than males (50.5 ± 13.4 years vs 37.2 ± 14.2; p = 0.017). Sudden cardiac deaths (SCD) accounted for 87 % of cases. Ischemic heart disease was the predominant pathology (58 %), mainly affecting men ≥ 36 years of age. Cerebral haemorrhage (8 %) and asthma (5 %) were the leading non-cardiac causes. In young adults, SADS (36 %) and asthma (27 %) were the main causes The disease responsible of SCD was diagnosed in life in 7 subjects. In 64 % there were cardiovascular risk factors, mainly obesity. Toxicological analysis detected illicit drugs (23 %), mainly cocaine, medications for erectile dysfunction (9 %), and ethanol ≥ 0.5 g/L (8 %). Deaths occurred usually in the context of heterosexual intercourse and during or immediately after sexual activity. The most common location was at home (63 %). In 12 men the sexual partner was a sex worker.
SArSD has a low incidence in the general population affecting middle-aged males during intercourse with a heterosexual partner. It is of cardiovascular origin, mainly due to ischemic heart disease that frequently remained silent during life. There is a frequent association with obesity, use of cocaine (and, to a lesser extent, medications for erectile dysfunction) and performing unconventional sexual practices. Forensic investigation is useful for developing prevention strategies.
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