Alberto Pasamontes

Leiden University | LEI · Analytical Bioscience Division

Volumetric Absorptive Micro Sampling (VAMS) strategy, in its simplicity, has made a major contribution to the development of at-home sampling strategies. Mainly used for blood analysis, it absorbs a fixed volume of sample. Folded into its cover, the VAMS device dries, and it can be sent to a lab via mail. In this article, for the first time in our...

Monitoring plant volatile organic compound (VOC) profiles can reveal information regarding the health state of the plant, such as whether it is nutrient stressed or diseased. Typically, plant VOC sampling uses sampling enclosures. Enclosures require time and equipment which are not easily adapted to high throughput sampling in field environments. W...

Monitoring health conditions is essential to detect early asymptomatic stages of a disease. To achieve this, blood, urine and breath samples are commonly used as a routine clinical diagnostic. These samples offer the opportunity to detect specific metabolites related to diseases and provide a better understanding of their development. Although bloo...

Health assessments of wild cetaceans can be challenging due to the difficulty of gaining access to conventional diagnostic matrices of blood, serum and others. While the non-invasive detection of metabolites in exhaled breath could potentially help to address this problem, there exists a knowledge gap regarding associations between known disease st...

Human skin presents a large, easily accessible matrix that is potentially useful for diagnostic applications based on whole body metabolite changes - some of which will be volatile and detected using minimally invasive tools. Unfortunately, identifying skin biomarkers that can be reliably linked to a particular condition is challenging due to a lar...

Exhaled breath condensate (EBC) analysis is a developing field with tremendous promise to advance personalized, non-invasive health diagnostics as new analytical instrumentation platforms and detection methods are developed. Multiple commercially-available and researcher-built experimental samplers are reported in the literature. However, there is...

Chemical analysis of exhaled breath metabolites is an emerging alternative to traditional clinical testing for many physiological conditions. The main advantage of breath analysis is its inherent non-invasive nature and ease of sample collection. Therefore, there exists a great interest in further development of this method for both humans and anim...

Modern differential mobility spectrometers (DMS) produce complex and multi-dimensional data streams that allow for near-real-time or post-hoc chemical detection for a variety of applications. An active area of interest for this technology is metabolite monitoring for biological applications, and these data sets regularly have unique technical and d...

The natural porosity of eggshells allows hen eggs to become contaminated with microbes from the nesting material and environment. Those microorganisms can later proliferate due to the humid ambient conditions while stored in refrigerators, causing a potential health hazard to the consumer. The microbes’ volatile organic compounds (mVOCs) are releas...

Citrus tristeza virus (CTV) (genus Closterovirus) is a plant pathogen which infects economically important citrus crops, resulting in devastating crop losses worldwide. In this study, we analyzed leaf metabolite extracts from six sweet orange varieties and a mandarin × tangor cross infected with CTV collected at the Lindcove Research and Extension...

Volatile organic compounds (VOCs) are off-gassed from all living organisms and represent end products of metabolic pathways within the system. In agricultural systems, these VOCs can provide important information on plant health and can ordinarily be measured noninvasively without harvesting tissue from the plants. Previously we reported a portable...

The porosity of the outer poultry eggs shell allows pathogens to arrive inside egg by penetrating the eggshell. Under humid ambient storing conditions in refrigerators, eggs can be colonized by fungi and bacteria. Volatile organic compounds (VOCs) are produced by bacteria and fungi as they proliferate, and these chemicals are emitted back through t...

RATIONALE: Pressure ulcers are a major economic and clinical problem in hospitals and intensive care units. Current methods to detect and grade pressure ulcers use subjective measures, and, presently, there are few ways to detect developing pressure ulcers which are not clinically evident. Here we aimed to employ a model to identify if volatile org...

Citrus tristeza virus (CTV) (genus Closterovirus) is a plant pathogen which infects economically important citrus crops such as sweet oranges, mandarins, limes and grapefruit varietals. Within the last 70 years, an estimated 100 million citrus trees have been destroyed due to CTV infection worldwide. Present measures to contain CTV infection includ...

Changing ocean health and the potential impact on marine mammal health is gaining global attention. Direct health assessments of wild marine mammals, however, is inherently difficult. Breath analysis metabolomics is a very attractive assessment tool due to its non-invasive nature, but is analytically challenging. It has never been attempted in ceta...

An important challenge to pulmonary arterial hypertension (PAH) diagnosis and treatment is early detection of occult pulmonary vascular pathology. Symptoms are frequently confused with other disease entities that lead to inappropriate interventions and allow for progression to advanced states of disease. There is a significant need to develop new m...

Flavescence dorée (FD) is one of the most widely known grapevine yellows disease and one of the most unabated worldwide in the viticulture sector. In this paper, we outline a strategy for developing an integrated system of technologies to enable rapid, early disease FD detection and diagnosis. We propose the deployment of a newly developed sensor d...

bstract The viability of the multi-billion dollar global citrus industry is threatened by the "green menace" - citrus greening disease (Huanglongbing, HLB) caused by the bacterial pathogen Candidatus Liberibacter. The long asymptomatic stage of HLB makes it challenging to detect emerging regional infections early to limit disease spread. We have es...

Diabetes type-2 and the metabolic syndrome are prevalent in epidemic proportions and result in significant co-morbid disease. Limitations in understanding of dietary effects and cholesterol metabolism exist. Current methods to assess diabetes are essential, though many are invasive; for example, blood glucose and lipid monitoring require regular fi...

Plant systems are frequently important agriculture commodity crops, and it can be critical to track emerging pathogen infections or nutrient deficiencies that can limit or prevent food production. While some methods have been developed for in field monitoring, they are frequently invasive and not rapid. Volatile organic compounds (VOCs) are produce...

Mobile health diagnostic systems are currently in development for many clinical applications, with special emphasis on non-invasive or minimally-invasive technologies. One very promising area of research focuses on measuring trace metabolites and other chemicals identified in exhaled breath. There are many potential clinical applications of these s...

A challenge to pulmonary hypertension diagnosis and treatment is the early detection of occult pulmonary vascular pathology. At our current state of knowledge patients often, despite recognized risk factors for disease, present only after a prolonged interval of symptoms. These symptoms are frequently confused with other disease entities that lead...

Asthma and chronic obstructive pulmonary disease (COPD) are distinct but clinically overlapping airway disorders which often create diagnostic and therapeutic dilemmas. Current strategies to discriminate these diseases are limited by insensitivity and poor performance due to biologic variability. We tested the hypothesis that a gas chromatograph/di...

We studied the evolution of thermophily in prokaryotes using the phylogenetic relationships between 279 bacteria and archaea and their thermophilic amino acid composition signature. Our findings suggest several examples in which the capacity of thermophilic adaptation has been gained or lost over relatively short evolutionary periods throughout the...

In this study, we report a method for finding an analytical sequence that allows to simultaneously determine two analytes with very similar physical and chemical characteristics, such as amoxicillin and clavulanic acid, using sequential injection analysis (SIA) with a diode-array spectrophotometric detector and multivariate curve resolution with al...

A totally automatized procedure for determining chromium by sequential injection analysis (SIA) linked to multivariate curve resolution with alternating least squares (MCR-ALS) is proposed. With this system Cr(III) is oxidised to chromate (Cr(VI)) and this form is then converted to dichromate in order to obtain second order data. The experimental d...

Optimal growth temperatures, G+C content and position in the x and y axes of figure 3 of the organisms analyzed. Thermophilic organisms (defined as species with an optimal growth temperature above 60°C) are shown in red.

COG family, function and position on the x and y axis of figure 2 of the genes common to all species analyzed.

An experimental design method was applied to determine the optimum working conditions for sequential injection analysis (SIA) to obtain second-order data that will be treated using multivariate curve resolution with alternating least squares (MCR-ALS). The critical step is to design an analytical sequence that provides relevant information. This se...

Amino acids in proteins are not used equally. Some of the differences in the amino acid composition of proteins are between species (mainly due to nucleotide composition and lifestyle) and some are between proteins from the same species (related to protein function, expression or subcellular localization, for example). As several factors contribute...

In this paper, we report on a method for quantifying clavulanic acid and amoxicillin simultaneously in pharmaceuticals using sequential injection analysis (SIA) with a diode-array spectrophotometric detector and multivariate curve resolution with alternating least squares (MCR-ALS). We optimized the experimental parameters so that the analytical se...

This article discusses the potential of using sequential injection analysis (SIA) for generating second-order data. To treat these data, we used multivariate curve resolution with alternating least squares (MCR–ALS) as the chemometric tool. This combination can be used for both qualitative and quantitative analyses, since it provides concentration...

In this study, we report a method for quantifying amoxicillin in pharmaceuticals in the presence of interferents using sequential injection analysis (SIA) with a diode-array spectrophotometric detector and multivariate curve resolution with alternating least squares (MCR–ALS). With a suitable analytical sequence, we can use SIA to generate a pH gra...

In this study, we report a method for determining amoxicillin in pharmaceuticals using sequential injection analysis (SIA) with a diode-array spectrophotometric detector. Before determining the amoxicillin, we use multivariate curve resolution with alternating least squares (MCR-ALS) to investigate whether any interferents are present. With a suita...