Microchemical Reaction Research Articles

Biomimetic Transparent Slippery Surface for the Locomotion of Photocontrol Droplets and Bubbles.

Directed transportation and collection of liquids and bubbles play a vital role in the survival of ecosystems. Among them, the optical response control is widely used in the fields of microfluidic chips and chemical synthesis because of its high remote operation and fast response speed. However, due to poor light transmission, the development direction of traditional near-infrared (NIR) absorbing materials in the field of visualization is limited, and there are few reports of manufacturing an operating platform that can realize the directional movement of droplets/bubbles on a single platform. Here, a transparent photo-responsive PBFS platform is prepared for droplet and bubble manipulation by coating the etched glass substrate with Prussian blue (PB) nanocubes. When near-infrared (NIR) irradiation on the PBFS platform, PB nanocubes trigger heat production by photothermal means, due to the action of Marangoni force, the surface tension on the left and right sides of the droplets and bubbles is not uniform, forming a surface tension gradient, thereby driving the movement of the droplets and bubbles. The control platform has good application potential in the field of microchemical reaction and biomedical engineering and brings new solutions to the field of transparent photothermal materials.

Brass corrosion – dezincification in hydrochloric acid

Abstract Brass is among the utility metals for daily life. We present an easy corrosion experiment for demonstration in high school or first-year undergraduate studies. Almost any kind of brass can be dezincified in 1 m hydrochloric acid. Copper as the noble component remains as salmon pink coating on the workpiece while zinc and lead, the latter being a frequent minor alloying component of brass, are dissolved. Lead can be detected as PbS (in-situ generation of H2S from a splinter of FeS or as PbI2 using KI). Zinc can be analyzed as Rinmann’s green or via a microchemical drop reaction with dithizone.

The Lignicolous Genus Entonaema: Its Phylogenetic–Taxonomic Position within Hypoxylaceae (Xylariales, Fungi) and an Overview of Its Species, Biogeography, and Ecology

The lignicolous saprotrophic genus Entonaema contains six formally accepted species: E. liquescens (type species), E. cinnabarinum, E. globosum, E. dengii, E. moluccanum, and E. siamensis. Its stromatic ascomata develop on the surface of dead wood remnants; they are rather large, globose to irregularly shaped, and vividly coloured. The fresh stroma interior is filled with a liquid matter. In early studies, the genus was considered to have a preference for tropical habitats, while in more recent field research, numerous collections have been added from warm, temperate areas of Europe, North America, and Asia. Our taxonomic and phylogenetic studies were based on freshly collected E. cinnabarinum from Croatia and E. liquescens from the USA. A phylogenetic study of the sequence alignment of four concatenated gene regions (ITS, LSU, rpb2, and β-tub) revealed the true taxonomic position of Entonaema within Hypoxylaceae (Xylariales), a sister to Hypoxylon carneum. Detailed macroscopic and microscopic descriptions of E. cinnabarinum are accompanied by drawings and colour photographs, while the study of E. liquescens is focused on stromatal microchemical reaction. With new information, the worldwide identification key to the putative species of Entonaema is proposed. Ecological data and biogeographical patterns were studied using all available and reliable sources of recorded data. Climatic preferences of the two most widespread Entonaema species, E. liquescens and E. cinnabarinum, are discussed in detail.

Active Droplet Transport Induced by Moving Meniscus on a Slippery Magnetic Responsive Micropillar Array.

Intelligent droplet manipulation plays a crucial role in both scientific research and industrial technology. Inspired by nature, meniscus driving is an ingenious way to spontaneously transport droplets. However, the shortages of short-range transport and droplet coalescence limit its application. Here, an active droplet manipulation strategy based on the slippery magnetic responsive micropillar array (SMRMA) is reported. With the aid of a magnetic field, the micropillar array bends and induces the infusing oil to form a moving meniscus, which can attract nearby droplets and transport them for a long range. Significantly, clustered droplets on SMRMA can be isolated by micropillars, avoiding droplet coalescence. Moreover, through adjusting the arrangement of the micropillars of SMRMA, multi-functional droplet manipulation such as unidirectional droplet transport, multi-droplet transport, droplet mixing, and droplet screening can be achieved. This work provides a promising approach for intelligent droplet manipulation and unfolds broad application prospects in microfluidics, microchemical reaction, biomedical engineering, and other fields.

Pharmacognostic Evaluation and Development of Quality Control Parameters for Root of Abelmoschus manihot (L.) Medik

Pharmacognosy Research,2023,15,1,101-111.DOI:10.5530/097484900263Published:December 2022Type:Original ArticleAuthors:Deshraj Shyamkant Chumbhale, and Mahendra Shivshankar Khyade Author(s) affiliations:Deshraj Shyamkant Chumbhale1, Mahendra Shivshankar Khyade2,* 1Department of Pharmacognosy, Amrutvahini College of Pharmacy, Sangamner, Ahmednagar, Maharashtra, INDIA. 2Department of Botany, Sangamner Nagarpalika Arts, D.J. Malpani Commerce and B.N. Sarda Science College (Autonomous), Sangamner, Maharashtra, INDIA. Abstract:Background: In traditional medicine, Abelmoschus manihot (L.) Medik, which belongs to the Malvaceae family, has been used to treat boils, sores, sprains, inflammations, tuberculosis, and leucoderma. Objectives: The objective of this study was to establish identification and quality control standards. Materials and Methods: For pharmacognostic evaluation, macroscopy, micromorphology and physicochemical constants have been used. Microchemical colour reaction tests and HPTLC studies were performed for qualitative phytochemistry. Results: Externally the root is yellowish-brown to yellowish-white and has a distinct odour, bitter taste, wavy shape, and smooth texture. The periderm was composed of 4-5 thin-walled cells. The secondary phloem has dilated rays and broad pyramid-shaped mucilage-packed rays. The fibres have thin walls and are narrow, and the secondary xylem is a compact circular cylinder with eight to eight radial lines of vessel chains. Prismatic calcium oxalate crystals, lignified long, narrow, thick-walled fibres with parenchyma cells, lignified cork cells, and cylindrical vessel elements were discovered in powdered samples. Physicochemically, the ash value was found above 8% which shows more than 75% solubility in acid whereas water and methanol extractive values were found to be just above and below 8% respectively. In UV-fluorescence study, very distinctive colour changes of the powdered root have been recorded. The phytochemical analysis reveals the presence of glycosides, saponins, flavonoids, tannins, and steroids. GC-MS and HPTLC are also used to characterize lipid and phenolic molecules. Conclusion: These findings will help in the future identification and quality control of A. manihot as reference standards. Keywords:Abelmoschus manihot, Pharmacognosy, Physicochemistry, PhytochemistryView:PDF (854.67 KB)

Supratough and stretchable hydrogels with time-space controllability for athletic rehabilitation

There is a higher risk of injury for athletes when the intensive competition occurs. Minimally invasive surgery is still the first choice for athletes because of its small wound surface and fast recovery. In addition, knowing whether athletes recover in real time at the first time is beneficial for the athletes to return to the competition as soon as possible and maintain their peak performance. We developed a medical hydrogel to meet the dual needs of minimally invasive therapy and wearable testing. A novel ε-PL/PVP/MXene (εPM) hydrogel with spatio-temporal control and in situ enhancement was prepared by the concept of microchemical reaction cavity. MXene was introduced as the microchemical reaction center, and the dual effects of heat transport and microcatalysis were utilized to make the gel network uniform and moldability after injection in vivo, so as to realize the filling and treatment of irregular wounds. The hydrogel tissue is not only adhesive, self-healing and soft, but also super tough, keeping its shape stable under repeated stretches, intense hammering, continuous trampling, and even the extremely catastrophic impact of being run over 50 times by a car. At the same time, the hydrogel has excellent ionic conductivity (4.12 S/m) and sensing ability, which can record athletes' movement characteristics in real time and transmit them to doctors through wireless Bluetooth, so as to make accurate judgment on the recovery of health. This is the first exploration of the combination of hydrogel in the field of minimally invasive therapy and wearable devices, which opens up a new avenue for efficient minimally invasive therapy and accurate rehabilitation monitoring.

Biocompatible Ferrofluid Robot With Photothermal Property for Targeted Tumor Therapy

Magnetic-controlled micro-robots have promising applications in disease therapy due to their high targetability and drug utilization. Due to their unique deformable and divisible properties, ferrofluid robots have gained much attention in microchemical reaction chips and micromanipulation. This letter proposes a biocompatible ferrofluid robot and validates its potential to achieve targeted drug delivery and tumor cell killing. This biocompatible ferrofluidic robot contains 10 nm oleic acid-coated ferric tetroxide particles and vegetable oil and has good magnetic responsiveness, deformability, and photothermal properties, and can move in liquid environments such as blood. It can achieve motion with an error of less than 0.4 mm under closed-loop control and obstacle overturning and passage through narrow channels less than twice its diameter. In addition, the biocompatible ferrofluid robot can kill tumor cells in the target area due to the photothermal properties of the magnetic particles, and experimental results show that the tumor cell death rate can reach 95%. These capabilities give the biocompatible ferrofluid robot a significant advantage in getting the target location for cancer treatment through the vascular environment.

Pharmacognostic and Phytochemical Evaluation of Leaf of Jatropha nana var. bengalense C.H. Rahaman and S. Mondal: An Endemic Member of Euphorbiaceae

Pharmacognosy Research,2022,14,2,204-210.DOI:10.5530/pres.14.2.29Published:April 2022Type:Original ArticleAuthors:Swarnendu Mondal, and Nayan Roy Author(s) affiliations:Swarnendu Mondal1,*, Nayan Roy2 1Department of Botany, Tribal Medicine and Pharmacognosy Lab., MUC Women’s College, Burdwan, West Bengal, INDIA. 2Department of Zoology, Ecology Research Unit, MUC Women’s College, Burdwan, West Bengal, INDIA. Abstract:Background: Pharmacognostic and phytochemical studies helps to maintain the quality of herbal products and purity of crude drugs by means of standardized parameters which will lead to developing the safest and efficacious natural products. Objectives: This study was undertaken to carry out pharmacognostic and phytochemical investigation of the leaves of the Jatropha nana var. bengalense (Euphorbiaceae), an ethnomedicinal plant. Materials and Methods: Epidermal Micromorphology, physical and physicochemical constants like ash value determination and UV-fluorescence study have been employed for pharmacognostic evaluation. For qualitative phytochemistry, microchemical color reaction test and TLC studies performed. Variations in different biochemical parameters of leaves of different developmental stages have been examined and the obtained data statistically analyzed following standard methods. Results: Typical paracytic type of stomata is found in hypostomatic condition distributed in irregular-shaped epidermal cells. Index of these stomata was found 20.251%. Phytochemical analysis in qualitative and quantitative approaches has also been done to describe its chemical variability. Ash value was found above 8% which shows more than 50% solubility in acid whereas water and ethanol solubility is found to be just below and above the 30% respectively. In UV- fluorescence study very distinctive colour changes of the powdered leaf have been recorded. Alcoholic extracts have shown positive results for presence of most of the phytochemical groups. Quantitative phytochemical analysis confirms that a range of phytochemicals are present in good amount in the leaves of this medicinal plant which could vary in amount in different developmental states. Thin Layer Chromatography has been carried out on ethanolic extract in two different solvent systems which show 6 different Rf values further indicates the presence of important phytochemical derivatives. Conclusion: This study will finally be needful for standardization of identification of the genuine drug, its adulterants and of the chemical constituents present in the leaves and finally bioprospection. Key words: Adulteration, Bioprospection, Euphorbiaceae, Jatropha nana var. bengalense, Pharmacognosy. View:PDF (450.58 KB)

Bioinspired Superhydrophobic Cilia for Droplets Transportation and Microchemical Reaction

AbstractIn nature, fluid manipulation plays a crucial role in the life of organisms, which has attracted great attentions of research and industry. Here, a functional bionic cilia surface is designed via the simple magnetic field assistance and laser etching technique. Multidirectional droplet transportation occurs on superhydrophobic cilia surface, which has good mechanical, physical, and chemical stability. The as‐prepared surface covered with cilia in the superhydrophobic (WCA of 156 ± 2°) and hydrophobic (WCA of 119 ± 3°) area possess different adhesion state, which can be used for multiple chemical reactions as a microreaction platform. Furthermore, bionic cilia surface can be used as a transport tool in the analysis and detection with average transfer speed of 2.3 cm s−1, which provides new opportunities in the development of small analysis equipment. Importantly, magnetically induced bionic cilia surfaces have broad potential applications in developing smart surfaces, droplet control, lab‐on‐a‐chip, etc.

Prevalence and risk factors of anemia among children aged 6\u201323\u2009months in Huaihua, Hunan Province

BackgroundAnemia is one of the most common diseases of childhood and is a health problem globally, particularly in developing counties and in children less than 2 years of age. Anemia during childhood has short- and long-term effects on health. However, few studies have investigated the prevalence of anemia among children in Huaihua. Therefore, this study analyzed the prevalence and risk factors of anemia among children 6 to 23 months of age in Huaihua.MethodsThis cross-sectional study was conducted at a maternal and child health care hospital in Huaihua, from September to November 2017. The study population recruited using a multistage sampling technique. A structured questionnaire was used to collect data on the characteristics of the children and members of their families. Hemoglobin (Hb) levels were measured by using a microchemical reaction method. Logistic regression analysis was used to identify associated factors and odds ratio with 95% CI was computed to assess the strength of association.ResultsIn total, 4450 children were included in this study. The prevalence of anemia was 29.73%. In multivariate logistic regression analysis, the results show that mother and father of Miao ethnicity (OR = 1.23 and 1.31), diarrhea in the previous 2 weeks (OR = 1.35), breastfeeding in the prior 24 h (OR = 1.50), and caregivers able to identify the optimum timing of complementary feeding (OR = 1.15) had positive correlations with anemia. However, children aged 18 to 23 months (OR = 0.55), father of Dong ethnicity (OR = 0.82), addition of milk powder once or twice (OR = 0.71), addition of infant formula once or twice, three times, and four or more times in the previous 24 h (OR = 0.72, 0.70, and 0.75), and addition of a nutrient sachet four or more times in the prior week (OR = 0.70) were negatively associated with anemia.ConclusionsThe prevalence of anemia among children 6 to 23 months of age in Huaihua was higher than that in more developed regions of China. The feeding practice of caregivers was associated with anemia. nutrition improvement projects are needed to reduce the burden of anemia among children in Huaihua.

Research on ice fixed-abrasive polishing mechanism and technology for high-definition display panel glass

This study introduces an ice fixed-abrasive polishing (IFAP) technology. Using silica solution IFAP pad and Al2O3 IFAP pad, orthogonal tests were performed on polishing high-definition display panel glass, respectively. The results show that the polishing efficiency and effect polished with silica solution IFAP pad are better than those polished with Al2O3 IFAP pad. The optimised silica solution IFAP parameters are: polishing pressure 0.1 MPa, polishing time 40 min, table velocity 80 r/min and the ratio of accelerator and slurry 1:10. Finally, the IFAP mechanism was studied and it is suggested that IFAP is a comprehensive effect of mechanical removal and microchemical reaction, combined with fixed abrasive polishing and free abrasive polishing.

An Integrative Mesh with Dual Wettable On–Off Switch of Water/Oil

AbstractSmart dual selective water/oil separation mode appears on an integrative mesh, which is fabricated via combined anodic oxidation and cathodic electrode‐deposition methods. Due to the different transport directions of oil and water, oil–water mixture can be separated completely using tailor‐made device. Extrusion pressure, acting as a critical pressure that depends on liquid surface tension, substrate microstructures, and wetting properties, can be a major factor to determine the passing or blocking mode. These remarkable water/oil separation properties of the integrative mesh can bring about novel applications in fluid rectifying, microchemical reaction manipulation, advanced separation, biomedical materials, purifying industrial wastewater, etc.

Feasibility Study on Continuous Flow Controlled/Living Anionic Polymerization Processes

A practical microchemical reaction system for keeping process flow at defined conditions, which is one of the key issues of industrial production, was developed. Controlled/living anionic polymerization was chosen as a test reaction because the molecular weight and molecular weight distribution of polymer products are quite sensitive to the relative flow rate of an initiator solution and that of a monomer solution. The polymerization of styrene in THF/hexane was carried out using a flow microreactor system consisting of two T-shaped micromixers and two microtube reactors using Smoothflow pumps at 0 °C. Poly(styrene) with higher molecular weight such as Mn > 10000 could be synthesized using s-BuLi (Mn = 14 000, Mw/Mn = 1.11). n-BuLi could also be used as an initiator. The continuous operation was performed for 3 h without any problems to obtain ca. 1 kg of the polymer, indicating the feasibility of continuous flow processes for controlled/living anionic polymerization on a relatively large scale.

은 나노입자 전극과 패러데이 모트를 이용한 미세유체 피코리터 주입기의 전압효율 상승

본 연구에서는 패러데이 모트를 사용한 기존의 피코리터 주입용 미세유체 칩에 은 나노입자를 이용한 전극을 추가하여 전압을 낮추며 효율을 높이는 실험을 수행하였다. 먼저, 복잡한 제조공정에서 탈피하여 은 나노입자 용액을 한 방울 떨어뜨리는 간단한 과정만으로 미세유체 피코리터 주입기 내에 전극을 제조하였다. 본 개념을 통한 은 나노입자 전극과 패러데이 모트가 통합된 미세유체 칩은 은 나노입자 전극을 사용하지 않는 기존 미세유체 칩의 피코리터 주입 시작 전압인 260 V 보다 낮은 전압인 180 V에서 피코리터 주입이 작동되었다. 또한 미세유체 피코리터 주입기는 피코리터 주입 부피를 7.5 pL부터 27.5 pL까지 정밀하게 조절할 수 있음을 주된 장점으로 하고 있다. 본 미세유체 피코리터 주입기는 미세유체 시스템의 새로운 기능을 설계함으로써 각 연구분야를 탐구할 유용한 플랫폼으로 기대되고 있다. This study presents modified microfluidic picoinjector combined Faraday moat with silver nanoparticle electrode to increase electrical efficiency and fabrication yield. We perform simple dropping procedure of silver nanoparticles near the picoinjection channel, which solve complicate fabrication process of electrode deposition onto the microfluidic picoinjector. Based on this approach, the microfluidic picoinjector can be reliably operated at 180 V while conventional Faraday moat usually have performed above 260 V. Thus, we can reduce the operation voltage and increase safety. Furthermore, the microfluidic picoinjector is able to precisely control injection volume from 7.5 pL to 27.5 pL. We believe that the microfluidic picoinjector will be useful platform for microchemical reaction, biological assay, drug screening, cell culture device, and toxicology.

Droplet and Fluid Gating by Biomimetic Janus Membranes

The ability to gate (i.e., allow or block) droplet and fluid transport in a directional manner represents an important form of liquid manipulation and has tremendous application potential in fields involving intelligent liquid management. Inspired by passive transport across cell membranes which regulate permeability by transmembrane hydrophilic/hydrophobic interactions, macroscopic hydrophilic/hydrophobic Janus‐type membranes are prepared by facile vapor diffusion or plasma treatments for liquid gating. The resultant Janus membrane shows directional water droplet gating behavior in air‐water systems. Furthermore, membrane‐based directional gating of continuous water flow is demonstrated for the first time, enabling Janus membranes to act as facile fluid diodes for one‐way flow regulation. Additionally, in oil‐water systems, the Janus membranes show directional gating of droplets with integrated selectivity for either oil or water. The above remarkable gating properties of the Janus membranes could bring about novel applications in fluid rectifying, microchemical reaction manipulation, advanced separation, biomedical materials and smart textiles.

Electric charge-mediated coalescence of water droplets for biochemical microreactors.

This work proposes the use of charged droplets driven by the Coulombic force as solution-phase reaction chambers for biological microreactions. A droplet can be charged near an electrode under dc voltage by direct contact to the electrode. This process is called electrical charging of droplet (ECOD). This charged droplet can then be transported rapidly between electrodes following the arc of an electric field line by exploiting electrostatic force. As on-demand electrocoalescence, both alkalization of phenolphthalein and bioluminescence reaction of luciferase in the presence of adenosine triphosphate are studied to test the feasibility of the biochemical microreactors using ECOD. Two oppositely charged droplets are merged to have a color change immediately after microchemical reaction. The applicability of an ECOD-driven droplet to measurement of glucose concentration is also tested. The glucose concentration is measured using a colorimetric enzyme-kinetic method based on Trinder's reaction [J. Clin. Pathol. 22, 158 (1969)]. The color change in the merged droplet is detected with an absorbance measurement system consisting of a photodiode and a light emitting diode.

On-Line UV Spectrophotometric Analysis for Organic Chemistry of Novel Inorganic Polymer Derived Microreactor

The use of microfluidic or lab-on-a-chip system has shown great promise for many applications. We have previously reported fabrication and application of preceramic polymer derived chemically and mechanically stable microfluidic devices in organic synthesis. Even though organic reactions are successfully performed, it is hard to analyze product to evaluate yields without any time delay except for integration of detecting module in the devices. Moreover small sample volume makes it even difficult to analyze sample by conventional analytical tools. Removal of catalyst and by product before analysis is another hurdle in evaluating performance of microrector. In this paper we describe preliminary results for simple on-line (real-time) quantitative analysis of microchemical reaction in preceramic polymer derived microreactor without reconstruction of microreactor or expensive components. A commercial UVNIS spectrophotometer is used to monitor well established Knoevenagel reaction. To evaluate the performance of presented on-line UV/IS monitoring system, UV/IS data are compared with off-line gas chromatography based analysis system.

Fluorescence-based assay with enzyme amplification on a micro-flow immunosensor chip for monitoring coplanar polychlorinated biphenyls

Detection of pollutants is of significant importance for environmental protection. However, conventional monitoring methods are often time-consuming, and require expensive equipments. Biosensors based on enzyme linked immunosorbent assay (ELISA) provide an alternative method to conventional ones. In this research, the reduction in the size of ELISA utilizing micro-chemical reaction is described in a micro-flow immunosensor chip. The immunosensor chips were fabricated by micro-electromechanical system (MEMS) technology. The quantitative determination of coplanar polychlorinated biphenyls (Co-PCBs) was performed by using a micro-flow immunosensor chip. Polystyrene beads were used as the solid substrate for the immobilization of Co-PCB antibody. The antibody-immobilized beads were introduced into the flow channel. As a competitive ELISA, sample solution mixed with horseradish peroxidase (HRP) conjugated antigen, and non-HRP conjugated antigen was allowed to react in the flow channel. After the antigen–antibody reaction, addition of phosphate buffer solution containing hydrogen peroxide and the fluorogenic substrate produced a fluorescent dye, which was monitored with the resulting change in the fluorescence intensity. By using our micro-flow immunosensor chip, it was possible to determine the sensing range of Co-PCB derivatives up to 0.1 ppt in 30 s. This immunosensor chip had a wide linear range for Co-PCB detection from 0.1 pg/ml to 1.0 μg/ml. The regression analysis provided the correlation coefficients of r = 0.982−0.964 with good reproducibility and precision. In a series of five measurements with immunosensor chips prepared with a new batch of antibody-immobilized polystyrene beads, a relative standard deviation of 21.3% was obtained. Our immunosensor chip design reported here has the potential to be implemented to several different detection methodologies for numerous analytes.

Particle flow, mixing, and chemical reaction in circulating fluidized bed absorbers

A mixing model has been developed to simulate the particle residence time distribution (RTD) in a circulating fluidized bed absorber (CFBA). Also, a gas/solid reaction model for sulfur dioxide (SO 2) removal by lime has been developed. For the reaction model that considers RTD distribution inside the core and annulus regions of a CFBA, a macrochemical reaction can be simulated based on microchemical reaction dynamics. The presented model can predict SO 2 and lime concentration distributions inside the CFBA, and give the amount of lime needed to remove a given percentage of SO 2. It is found that SO 2 concentration decreases with the increase of CFBA distance from the bottom in the core region. However, lime concentration exhibits a very slight variation in the core region. This means that lime is efficiently utilized to remove SO 2. The model also predicts that SO 2 partial pressure at the exit of the CFBA decreases with the increase in the percentage of fresh lime injected in the CFBA.

Chemical reactions in microdroplets by electrostatic manipulation of droplets in liquid media

A microchemical reaction method involving microdroplets is proposed. Microdroplets are formed in a chemically stable medium on electric panel devices. These devices are substrates which have electrode arrays or electrode dots, and its surfaces are coated by an insulating film (such as Teflon or polypropylene) to prevent discharge and electrolysis of solutions. Microdroplets can be separately manipulated by a traveling electric field, which arises on applying a sequential voltage to the electrodes. Droplets moved smoothly at 1 Hz and voltage 400 V(0-p). Reagents were then put in droplets that were collided and coalesced, resulting in chemical reactions that included alkalization of phenolphthalein and the luciferin-luciferase reaction.