Portable device for on-site detection of ammonia nitrogen

Portable measurement of ammonia nitrogen in water is of great significance for water qual-ity monitoring.It’s beneficial to reduce biological diseases and promote aquatic product safety.Traditional methods such as Nessler’s reagent method suffer from complex opera-tion,time delays and toxic residues.To realize simple and pollution-free detection,this paper develops a low-cost portable device for ammonia nitrogen detection.A test paper was proposed to cooperate the device and offer a chromogenic reaction.The portable device reduces the impact of any ambient light,simplifies the operation,and provides human–computer interaction.The result obtained for the detection range of 0.4–10 mg/L(R^(2) are 0.9902 and 0.9893 for the rang of 0.4–4.5 and 4.5–10 mg/L,respectively)with the detection limit of 0.36 mg/L,and the average recovery of aquaculture water is 100.98–137.75%.The results show that the portable device can provide a great potential for on-site detection ammonia nitrogen concentration.

A portable device for studying the effects of fluid flow on degradation properties of biomaterials inside cell incubators

A portable device was designed and constructed for studying the properties of biomaterials in physiologically relevant fluids under controllable flow conditions that closely simulate fluid flow inside the body.The device can fit entirely inside a cell incubator;and,thus,it can be used directly under standard cell culture conditions.An impedance-driven pump was built in the sterile flow loop to control the flow rates of fluids,which made the device small and portable for easy deployment in the incubator.To demonstrate the device functions,magnesium(Mg)as a representative biodegradable material was tested in the flow device for immersion degradation under flow versus static conditions,while the flow module was placed inside a standard cell incubator.The flow rate was controlled at 0.1760.06 ml/s for this study;and,the flow rate is adjustable through the controller module outside of incubators for simulating the flow rates in the ranges of blood flow in human artery(0.050.43 ml/s)and vein(0.020.08 ml/s).Degradation of Mg under flow versus static conditions was characterized by measuring the changes of sample mass and thickness,and Mg2t ion concentrations in the immersion media.Surface chemistry and morphology of Mg after immersion under flow versus static conditions were compared.The portable impedance-driven flow device is easy to fit inside an incubator and much smaller than a peristaltic pump,providing a valuable solution for studying biomaterials and implants(e.g.vascular or ureteral stents)in body fluids under flow versus static conditions with or without cells.

Flexible polydimethylsiloxane pressure sensor with micro-pyramid structures and embedded silver nanowires:A novel application in urinary flow measurement

Flexible pressure sensors are lightweight and highly sensitive,making them suitable for use in small portable devices to achieve precise measurements of tiny forces.This article introduces a low-cost and easy-fabrication strategy for piezoresistive flexible pressure sensors.By embedding silver nanowires into a polydimethylsiloxane layer with micro-pyramids on its surface,a flexible pressure sensor is created that can detect low pressure (17.3 Pa) with fast response (<20 ms) and high sensitivity (69.6 mA kPa-1).Furthermore,the pressure sensor exhibits a sensitive and stable response to a small amount of water flowing on its surface.On this basis,the flexible pressure sensor is innovatively combined with a micro-rotor to fabricate a novel urinary flow-rate meter (uroflowmeter),and results from a simulated human urination experiment show that the uroflowmeter accurately captured all the essential shape characteristics that were present in the pump-simulated urination curves.Looking ahead,this research provides a new reference for using flexible pressure sensors in urinary flow-rate monitoring.

Portable Diagnostic Platform for Detection of Microorganisms Coliforms and E.coli

Portable diagnostic devices are a viable and low-cost alternative for the detection of pathogens, since they reduce the time of analysis of results availability. Ease of sample collection and quick diagnosis allow this new input to be applied in the diagnosis of the main contaminating microorganisms present in the water. Laboratory tests evaluated the technical viability of the diagnostic device, using commercial strains which were inoculated and optimized in the devices and their growth compared to the conventional method in Petri dishes. Samples of 100 μL bacterial suspension were tested and compared with the traditional sample inoculation method. The device viability was determined by detecting characteristic bacterial colonies in a specific culture medium through the colorimetric development of the obtained colonies. The feasibility assessments allow us to affirm that the device enables both qualitative and quantitative detection of the target bacteria present in liquid samples, and is promising to be applied to assess the quality of water, food and environmental surfaces.

Evaluating the performance and influencing factors of three portable black carbon monitors for field measurement

Black carbon(BC)is associated with adverse human health and climate change.Mapping BC spatial distribution imperatively requires low-cost and portable devices.Several portable BC monitors are commercially available,but their accuracy and reliability are not always satisfactory during continuous field observation.This study evaluated three models of portable black carbon monitors,C12,MA350 and DST,and investigates the factors that affect their performance.The monitors were tested in urban Beijing,where portable devices running for one month alongside a regular-size reference aethalometer AE33.The study considers several factors that could influence the monitors'performance,including ambient weather,aerosol composition,loading artifacts,and built-in algorithms.The results show that MA350and DST present considerable discrepancies to the reference instrument,mainly occurring at lower concentrations(0-500 ng/m^(3))and higher concentrations(2500-8000 ng/m^(3)),respectively.These discrepancies were likely caused by the anomalous noise of MA350 and the loading artifacts of DST.The study also suggests that the ambient environment has limited influence on the monitors'performance,but loading artifacts and accompanying compensation algorithms can result in unrealistic data.Based on the evaluation,the study suggests that C12 is the best choice for unsupervised field measurement,DST should be used in scenarios where frequent maintenance is available,and MA350 is suitable for research purposes with post-processing applicable.The study highlights the importance of assigning portable BC monitors to appropriate applications and the need for optimized real-time compensation algorithms.

Social media in cardiology:Reasons to learn how to use it

Social media has changed the way we learn,educate,and interact with our peers.The dynamic nature of social media and their immediate availability through our portable devices(smartphones,tablets,smartwatches,etc.)is quickly transforming the way we participate in society.The scope of these digital tools is broad as they deal with many different aspects:Teaching and learning,case discussion,congresses coverage,peer to peer interaction,research are examples worth mentioning.The scientific societies considered more innovative,are promoting these tools between their members.These new concepts need to be known by the cardiologists to stay updated,as countless information is moving rapidly through these channels.We summarize the main reasons why learning how to use these tools to be part of the conversation is essential for the cardiologist in training or fully stablished.

A review of rechargeable batteries for portable electronic devices

Portable electronic devices(PEDs)are promising information-exchange platforms for real-time responses.Their performance is becoming more and more sensitive to energy consumption.Rechargeable batteries are the primary energy source of PEDs and hold the key to guarantee their desired performance stability.With the remarkable progress in battery technologies,multifunctional PEDs have constantly been emerging to meet the requests of our daily life conveniently.The ongoing surge in demand for high-performance PEDs inspires the relentless pursuit of even more powerful rechargeable battery systems in turn.In this review,we present how battery technologies contribute to the fast rise of PEDs in the last decades.First,a comprehensive overview of historical advances in PEDs is outlined.Next,four types of representative rechargeable batteries and their impacts on the practical development of PEDs are described comprehensively.The development trends toward a new generation of batteries and the future research focuses are also presented.

Development of a portable multi-channel system for plant physiological signal recording

Bioelectrical signals can reflect physiological state of organs or tissues in plants and have a significant potential value in research of plant stress tolerance.In order to study the relationship between environment factors and electrical signals in plant,a portable multichannel physiological signal acquisition system which relevant in plant physiology research was developed.Environment parameters and electrical signals can be measured in different channels by the acquisition system simultaneously and the measurement data will be displayed in an embedded integrated touch screen which is the system processing core.The system was validated to be stable and reliable after the calibration and repeated experiments of recording electrical signals in Helianthus annuus L.

An in situ dressing material containing a multi-armed antibiotic for healing irregular wounds

Acute and infected wounds resulting from accidents,battlefield trauma,or surgical interventions have become a global healthcare burden due to the complex bacterial infection environment.However,conventional gauze dressings present insufficient contact with irregular wounds and lack antibacterial activity against multi-drug-resistant bacteria.In this study,we develop in situ nanofibrous dressings tailored tofit wounds of various shapes and sizes while providing nanoscale comfort and excellent antibacterial properties.Our approach involves the fabrication of these dressings using a handheld electrospinning device that allows for the direct depo-sition of nanofiber dressings onto specific irregular wound sites,resulting in perfect conformal wound closure without any mismatch in 2 min.The nanofibrous dressings are loaded with multi-armed antibiotics that exhibit outstanding antibacterial activ-ity against Staphylococcus aureus(S.aureus)and methicillin-resistant S.aureus.Compared to conventional vancomycin,this in situ nanofibrous dressing shows great antibacterial performance against up to 98%of multi-drug-resistant bacteria.In vitro and in vivo experiments demonstrate the ability of in situ nanofibrous dressings to prevent multi-drug-resistant bacterial infection,greatly alleviate inflammation,and promote wound healing.Ourfindings highlight the potential of these personalized nanofibrous dressings for clinical applications,including emergency,accident,and surgical healthcare treatment.

Plasma functionalized MoSe2 for efficient nonenzymatic sensing of hydrogen peroxide in ultra-wide pH range

Enzymatic sensors have inherent problems such as the low stability and limited pH range in industrial and biomedical applications and therefore,more efficient nonenzymatic sensors are highly desirable.Herein,plasmafunctionalized defective MoSe_(2)is prepared and studied as a highly efficient catalyst for electrochemical sensing of H_(2)O_(2).Experiments and theoretical computations show that the plasma-induced Se multi-vacancies and nitrogen dopants generate new active sites,expose more edge active surfaces,narrow the bandgap,and strengthen binding with the·OH intermediate,which imparts new fundamental knowledge about the roles of defects in catalysis.The defective MoSe_(2)-catalyzed sensor delivers competitive performance in hydrogen peroxide detection such as a low detection limit of 12.6 nmol/L,wide operational pH range of 1−13,good long-term stability,and high selectivity.The portable sensor produced by screen printing confirms the excellent commercial potential and in addition,the results not only reveal a novel concept to design and fabricate high-performance sensors for H_(2)_(O2)but also provide insights into the effectiveness of surface modification of diverse catalytic materials.

Transparent soft PDMS eggshell

In vivo 3D fluorescent image remains a technological barrier for biologists and clinical scientists although green fluorescent protein(GFP)imaging has long been performed rather well at cellular level.Meanwhile,robust enough portable devices are also challenging lab-on-a-chip advocators who wish their designs to be nurtured by the end users.This work is dedicated to propose a conceptually innovated transparent soft PDMS avian eggshell to directly tackle the above two goals.Here,an"egg-on-a-chip"scheme is originally developed and demonstrated by a newly developed PDMS"soft"process method.Unlike its ancestor–the conventional"lab-on-a-chip"(LOC)which is basically chemically based,the current"egg-on-a-chip",intrinsically inherited with biological natures,opens a way to integrate biological parts or whole system in a miniature sized device.Such biomimics system contains much condensed environmental evolutional tensor inside than those of the existing LOC compacted with artificial components which however are quite difficult to incorporate various life factors inside.Owning unique advantages,a series of transparent PDMS whole"eggshells"have been fabricated and applied to culture avian embryos up to 17.5 days and chimeric eggshells were engineered on normal eggs.In addition,X-stage embryos were successfully initiated in such system and pre-chorioallantoic membrane was observed.Further,limitation of the present process was interpreted and potential approach to improve it was suggested.With both high optical transparency and engineering subtlety fully integrated together,the present method not only provides an ideal transparent imaging platform for studying functional embryo development including life mystery,but also promises a future strategy for"lab-on-an-egg"technology which may be important in a wide variety of either fundamental or practical areas.

A general strategy to quantify analytes through fluorescence chromaticity and luminosity

To realize a fast,easy-operation and precise way using fluorescence probes to quantify analytes is a goal to facilitate detection,especially in situ.Herein,we are reporting an approach which can be generally employed for the differentiation and quantitation of analytes through fluorescence chromaticity and luminosity.Seven representative fluorescent probes,targeting p H,cysteine,hydrogen sulfide,hydrogen peroxide,palladium and hydrazine,were synthesized and tested.Without utilizing costly instrumentations,portable devices were employed to collect data of photographs from the fluorescence samples in responses to different analytes.Subsequently,the photographic images were digitally processed to generate calibration curves between chromaticity/luminosity verse concentrations after mapping to the CIE 1931 xy Y standard color space.Good linear calibration curves and quantitative analysis of unknown samples with low errors through the spectral technology demonstrated the reliability of this method.Thus,we showed the analytical method with a simple and on-site constructible/portable device which is promising for applications in more fluorescence probes.

An integrative review on the applications of 3D printing in the field of in vitro diagnostics

Biomedicine is one of the fastest growing areas of additive manufacturing.Especially,in the field of in vitro diagnostics(IVD),contributions of 3D printing include i)rapid prototyping and iterative IVD proof-of-concept designing ranging from materials,devices to system integration;ii)conceptual design simpli-fication and improved practicality of IVD products;iii)shifting the IVD applications from centralized labs to point-of-care testing(POCT).In this review,the latest developments of 3D printing and its advantages in IVD applications are summarized.A series of 3D-printed objects for IVD applications,including single-function modules,multi-function devices which integrate several single-function modules for specific an-alytical applications such as sample pre-treatment and chemo-/bio-sensing,and all-in-one systems which integrate multi-function devices and the instrument operating them,are analyzed from the perspective of functional integration.The current and potential commercial applications of 3D-printed objects in the IVD field are highlighted.The features of 3D printing,especially rapid prototyping and low start-up,en-able the easy fabrication of bespoke modules,devices and systems for a range of analytical applications,and broadens the commercial IVD prospects.