Phosphate Contaminant Detection in Water Through a Paper-based Microfluidic Device

This report describes a project aimed at developing a low-cost, portable, on-site, user-friendly system for detecting different concentrations of phosphate in drinking water. Phosphate is a natural chemical, but toxic in large concentrations; detection is therefore important to avoid drinking contaminated water. Despite this fact, no cheap, and/or nontoxic system for phosphate detection is yet on the market. The detection system utilizes a paper-based microfluidic device to automate the electrochemical detection process, which normally requires expert use of lab equipment. When combined with a portable potentiostat that works with a mobile app, the device will allow untrained users to determine if any source of drinking water contains unsafe levels of phosphate without equipment or training, and to communicate that information to a central database for further analysis. Those of any background, particularly in developing countries, will be able to maintain health and raise awareness about clean water. Microfluidic devices are useful tools for the detection of water contaminants, but there is a gap in technology for the detection of phosphate. Our phosphate detection system is a paper-based microfluidic device with an already-developed voltammetry device that automates the detection process so that any user can safely find phosphate in water. The system will provide a binary analysis about whether the water is safe to consume or not. Completion of the project provides a valuable tool to both average customers in developing countries and scientific researchers in determining the safety of drinking water

Review on bibliography related to antimicrobials

In this report, a bibliographic research has been done in the field of antimicrobials.In this report, a bibliographic research has been done in the field of antimicrobials. Not all antimicrobials have been included, but those that are being subject of matter in the group GBMI in Terrassa, and others of interest. It includes chitosan and other biopolymers. The effect of nanoparticles is of great interest, and in this sense, the effect of Ag nanoparticles and antibiotic nanoparticles (nanobiotics) has been revised. The report focuses on new publications and the antimicrobial effect of peptides has been considered. In particular, the influence of antimicrobials on membranes has deserved much attention and its study using the Langmuir technique, which is of great utility on biomimetic studies. The building up of antimicrobials systems with new techniques (bottom-up approach), as the Layer-by-Layer technique, can also be found in between the bibliography. It has also been considered the antibiofilm effect, and the new ideas on quorem sensing and quorum quenching.Preprin

High Throughput Screening of Clopidogrel Resistance Using Microfluidic Technology

The pre-treatment of patients with clopidogrel before primary percutaneous coronary intervention (PCI) has been shown to lower the risk of complications that could lead to heart attack or stroke during the procedure. However, the proper administration of clopidogrel requires the measurement of the patient’s drug resistance due to its inherent variation across the population. Approximately 1.1 million PCIs were performed in the US alone in 2008. As the patient population is becoming increasingly aware of the benefits of clopidogrel treatment prior to PCI, there is an ever-expanding market potential for clopidogrel resistance screening devices. As most of the existing devices utilize traditional test-tube-scale bench-top technology that usually sets limitations on the throughput and applicability of the test itself, the market demands a device that not only minimizes the cost per test but also produces consistent and comprehensive results. In this report, guided by the innovation map, we are able to link soft lithography in combination with micro-patterning technology to the customer’s requirements, and come up with a higher-throughput system that meets the market demand. Our system consists of two parts: the chip and the device. We focus our design effort primarily on the chip, in which micro-channel layout, dry reagent dissolution, reagent mixing and reservoir volume design are carefully worked out. On the other hand, the design of the device is discussed briefly, but production is assumed to be outsourced. With the cost estimates from suppliers and the assumed expected market share to be 50%, the net present value is computed to be about 45 million, indicating a lucrative return to investors

A study of volatile organic compounds from transgenic arabidopsis thaliana and solanum lycopersicum plants and analytical characterization of pyrolysis bio-oil

A dynamic headspace method was developed for the non-targeted analysis of volatile organic compounds (VOC) in Arabidopsis and Micro-Tom plants. The method allowed to determine differences from wild type (WT) and transformed plants overexpressing the carotene cleavage dioxygenase 1 (CCD1) genes. In the Arabidopsis study it was revealed the presence of unsaturated hydrocarbons, aromatic derivatives, alcohols, and terpenes. Among extracted volatiles, the apocarotenoid compound β-ionone was also detected, four-fold higher in the transgenic plants than the WT. There were not significant differences in the VOCs between the HS of Micro-Tom tomato plants overexpressing the CCD1 genes and WT. The compounds identified were mainly terpenes, and aromatic derivatives and there was no evidence of the presence of any apocarotenoid compound. A static headspace (SHS) method was developed for the analysis of VOCs in Micro-Tom tomato flowers. It was performed by simultaneously using three solid phase microextraction fibers. The non-targeted analysis revealed the presence of 45 volatiles from CCD1 plants and 35 from WT. Of the total VOCs identified, 30 were common to both types of plants, but 15 were specific to the CCD1 plants and 5 to the WT. In another study, bio-oil from tomato plant was generated by pyrolysis process. Bio-oil was fractionated according to its pesticidal properties. Neophytadiene, phytol and a number of fatty acids were identified in the most active fractions. Bioassays using these compounds showed partial insecticidal activity, suggesting that other unidentified compounds in the bio-oil fractions were also responsible for observed insecticidal activities

How Do Project-related Artefacts Qualify for Bridging Boundaries in IS Implementation Projects – An Activity Theoretical Perspective

Boundary objects were found to significantly impact the outcomes of IS implementation projects. Despite emphasizing their flexibility, however, prior research is no very precise on the attributes that qualifies project-related artefacts to become boundary objects. To identify the internal characteristics of artefacts that enable business and IT to synchronize IS and business needs, this research offers an activity theoretical view on boundary objects. The usefulness of the concept is demonstrated by means of an in-depth case study. The findings of this research emphasize that –in order to become boundary objects– project-related artefacts need to be part of the IS implementation and the business activity system. Moreover, they need to capture relevant knowledge of both activity systems and enable recognition of contradictions within and between. As to that, utilization of emerging project deliverables by means of internalization or externalization processes is found to facilitate the alignment between IS and business needs

Developing Wound Moisture Sensors: Opportunities and Challenges for Laser-Induced Graphene-Based Materials

Recent advances in polymer composites have led to new, multifunctional wound dressings that can greatly improve healing processes, but assessing the moisture status of the underlying wound site still requires frequent visual inspection. Moisture is a key mediator in tissue regeneration and it has long been recognised that there is an opportunity for smart systems to provide quantitative information such that dressing selection can be optimised and nursing time prioritised. Composite technologies have a rich history in the development of moisture/humidity sensors but the challenges presented within the clinical context have been considerable. This review aims to train a spotlight on existing barriers and highlight how laser-induced graphene could lead to emerging material design strategies that could allow clinically acceptable systems to emerge

The Microfluidic Multi-Surface Coagulation Assay: Microfluidic Analysis of Citrated Whole Blood

As technology improves, there is a push to minimize the cost of diagnostics as well as the cost of screening for novel drugs in the pharmaceutical industry. There is no exception in clinical point-of-care settings, and quick, fast, and inexpensive tests are needed to determine if patients require treatment or a change in dosage. The most successful endeavor in the realm of microfluidics is the InkJet printer, invented in 19801. Other examples of successful and developing microfluidic technology include polymerase chain reaction, high throughput DNA sequencing, and point-of-care pathology. It is therefore reasonable that micro-scale, more thorough and diagnostically relevant coagulation studies might be desired. Several hurdles exist to miniaturizing large scale processes, which stem from flow in the laminar regime. For example, on chip mixing is considered difficult since the Reynolds number reaches a limit so low that the fluid will not mix with particles on different streamlines. The Microfluidic Multi-Surface Coagulation Assay (µMCA) Chip introduces a novel way of recalcifying citrated whole blood on-chip, which simplifies the job of the operator and allows faster determination of results. Simple diffusion and convection of small particles combined with intuitive design make the design of this product not only functional but also inexpensive. Previous coagulation studies merely test one pathway to coagulation, and many do so in a test tube rather than under flow. The µMCA will test both intrinsic and extrinsic coagulation pathways under arterial shear rates, making results from the device more relevant to diagnostics or patient-specific dosage of coagulants or anticoagulants. In summary, the µMCA provides a streamlined and thorough way to measure patient specific clotting abilities in physically relevant flow regimes

The physiochemical responses of stored grain insect pests to synthetic amorphous silica (SAS) powders

Fumigation is widely used for the disinfestation of stored grain products. Every loss of grain during storage is a loss of all the inputs that produced the grain in the first place. In many situations, fumigation is the only feasible process for pest control. Currently, phosphine is the only fumigant accepted by international trade for the disinfestation of grain and oilseeds. However, phosphine resistance now occurs worldwide and has challenged the continued use of phosphine in the grain industry. Food-grade synthetic amorphous silica (SAS) can act as a phosphine resistance breaker in storage systems. This thesis explored the mechanisms of SAS powder for controlling two phosphine-resistant stored grain insects, red flour beetle (Tenebrionidae: Tribolium castaneum (Herbst, 1797)) and lesser grain borer (Bostrichidae: Rhyzopertha dominica (Fabricius, 1792)). Grain protection during storage is essential. Both contact grain protectants and fumigants leave toxic residue issues to humans and the environment. The world wants residue-free grain, especially countries where grain is a substantial proportion of the diet. A high sensitivity headspace-solid phase micro-extraction gas chromatograph-mass spectrometer (HS-SPME-GCMS) method was optimised and validated to determine the residues of eight fumigants simultaneously, including phosphine, methyl bromide, cyanogen, sulfuryl fluoride, ethylene oxide, propylene oxide, ethyl bromide and ethyl formate. A 2 cm long 50/30μm divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) coated SPME fiber was chosen based on its absorption performance. The food matrices included grain, oilseed, dried fruit, and nuts. The limits of detection (LODs) of the fumigants ranged between 0.03 to 1.99 ng/g. Responses to a range of diluted authentic standards gave significant (r2 > 0.9983) linear regressions and the relative standard deviations (RSDs) were ≤ 8.7% at the 3 ng/g level of aged spiking standard, except for sulfuryl fluoride with a LOD of 1.99 ng/g and an RSD value of 39.7% (6.64 ng/g). The performance of the HS-SPME-GCMS method was more sensitive than the gas syringe method for all fumigants, except sulfuryl fluoride. Due to residue issues, the world is increasingly demanding residue-free treatments. The main components of insects' cuticular lipids are hydrocarbon compounds. SAS powders may change the hydrocarbons on the cuticle, impacting an insect’s self-protection mechanism(s) against toxic gas chemicals, possibly by acting as a barrier between the insect and the surrounding phosphine environment. X-ray micro-computed tomography (Micro-CT) scanning of SAS treated and untreated T. castaneum indicated that the SAS powder penetrates the tracheal system of T. castaneum and potentially blocks it, leading to asphyxiation. Micro-CT 3D reconstruction model of R. dominica showed the internal body fluid was completely depleted and the internal organs shrank. Based on metabolomics, several energy metabolites and derivatives were found to alter after applying food-grade SAS powders to adult T. castaneum and R. dominica. Phosphine-resistant adults are known to downregulate or slow the consumption of energy substances to survive phosphine fumigation. Fortunately, the food-grade SAS powders accelerated the carbohydrate metabolism leading to the depletion of monosaccharides, and the blocking of the β-oxidation pathway causing the accumulation of free fatty acids (FFAs). The excess FFAs, including saturated and unsaturated FFAs, possibly induce the lethal toxicity of the fatty acids. The associated bioassay results show that hydrophilic (HL) SAS and hydrophobic (HB) SAS controlled the larvae and adults of T. castaneum and R. dominica; however, HB-SAS was more efficient than HL-SAS when the moisture content and relative humidity were high. HB-SAS stimulated T. castaneum to increase respiration and produce benzoquinones and derivatives, leading to its death within two hours of treatment. The respiration rate of the insects was monitored by Mass Spectrometry (MS), and varied with HL-SAS and hydrophobic HB-SAS treatments. Volatile organic chemicals were identified and quantitated from adult T. castaneum by headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GCMS). Three benzoquinone derivatives, ethyl p-Benzoquinone, methyl p-Benzoquinone, and ethyl 1, 3-Benzenediol, were increased significantly by 133.1, 43.1 and 41.9 folds, respectively. Importantly, these benzoquinone derivatives can be used as biomarkers to identify phosphine-resistant strains of T. castaneum two hours after SAS treatment by HS-SPME-GCMS. The smaller particle size allowed the two SAS dusts to pass through open spiracles during air exchange. Due to their light weight, SAS particles are carried along with airflow into the tracheole tubes, which lie within the haemolymph and internal tissues. Small amounts of biofluid in the tracheole tubes evaporated due to the SAS treatments leading to the overwhelming loss of oxygen and water near the muscle cells. Therefore, the irritation of the SAS powder particles provides high insecticidal efficacy, even against phosphine-resistant individuals. In conclusion, food-grade SAS powders kill phosphine-resistant insect adults, T. castaneum and R. dominica, by depleting sugar energy and inhibiting the β-oxidation of FFAs to energy substances. Consequently, SAS powders offer a viable, pesticide residue free alternative to phosphine for managing and eradicating stored product insects

Analysis of Project Construction Delay Using Fishbone Diagram at PT. Rekayasa Industri

Abstract.This research focuses on finding the root problem of the construction delay that happened in several tasks at PT Rekayasa Industri’s CGPX project. The project was planned to start on June 27th, 2011 and planned to be finished on April 8th, 2013. However, the actual project was finished almost one year later than the planned finished date (March 20th, 2014), despite the fact that the project started on time. The project delays will be analyzed through systematical methodology to find root cause that makes the project finished late using Ishikawa Diagram, then the result will be presented using “5M†criteria. Finally, the best solution will be given as a feedback to the company to improve future project. The result shows that the most powerful delay is caused by human error. The recommendation given to the company is to increase the ability of workers to reduce the delays in these aspects. Way to increase the ability is by doing training, hire more professional person, recruit the third party, or give penalty if the drawing is late.Keyword: Project management, fishbone diagram, project delay, root cause analysisÂ

Direct Contact - Sorptive Tape Extraction coupled with Gas Chromatography - Mass Spectrometry to reveal volatile topographical dynamics of lima bean (Phaseolus lunatus L.) upon herbivory by Spodoptera littoralis Boisd

BACKGROUND: The dynamics of plant volatile (PV) emission, and the relationship between damaged area and biosynthesis of bioactive molecules in plant-insect interactions, remain open questions. Direct Contact-Sorptive Tape Extraction (DC-STE) is a sorption sampling technique employing non adhesive polydimethylsiloxane tapes, which are placed in direct contact with a biologically-active surface. DC-STE coupled to Gas Chromatography – Mass Spectrometry (GC-MS) is a non-destructive, high concentration-capacity sampling technique able to detect and allow identification of PVs involved in plant responses to biotic and abiotic stresses. Here we investigated the leaf topographical dynamics of herbivory-induced PV (HIPV) produced by Phaseolus lunatus L. (lima bean) in response to herbivory by larvae of the Mediterranean climbing cutworm (Spodoptera littoralis Boisd.) and mechanical wounding by DC-STE-GC-MS. RESULTS: Time-course experiments on herbivory wounding caused by larvae (HW), mechanical damage by a pattern wheel (MD), and MD combined with the larvae oral secretions (OS) showed that green leaf volatiles (GLVs) [(E)-2-hexenal, (Z)-3-hexen-1-ol, 1-octen-3-ol, (Z)-3-hexenyl acetate, (Z)-3-hexenyl butyrate] were associated with both MD and HW, whereas monoterpenoids [(E)-β-ocimene], sesquiterpenoids [(E)-nerolidol] and homoterpenes (DMNT and TMTT) were specifically associated with HW. Up-regulation of genes coding for HIPV-related enzymes (Farnesyl Pyrophosphate Synthase, Lipoxygenase, Ocimene Synthase and Terpene Synthase 2) was consistent with HIPV results. GLVs and sesquiterpenoids were produced locally and found to influence their own gene expression in distant tissues, whereas (E)-β-ocimene, TMTT, and DMNT gene expression was limited to wounded areas. CONCLUSIONS: DC-STE-GC-MS was found to be a reliable method for the topographical evaluation of plant responses to biotic and abiotic stresses, by revealing the differential distribution of different classes of HIPVs. The main advantages of this technique include: a) in vivo sampling; b) reproducible sampling; c) ease of execution; d) simultaneous assays of different leaf portions, and e) preservation of plant material for further “omic” studies. DC-STE-GC-MS is also a low-impact innovative method for in situ PV detection that finds potential applications in sustainable crop management. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12870-015-0487-4) contains supplementary material, which is available to authorized users