The deficiency of potable water resources and energy supply is emerging as a significant and concerning obstacle to sustainable development.Solar and waste heat-powered humidification dehumidification(HDH)desalination...The deficiency of potable water resources and energy supply is emerging as a significant and concerning obstacle to sustainable development.Solar and waste heat-powered humidification dehumidification(HDH)desalination systems become essential due to the severe impacts of global warming and water shortages.This problem highlights the need to apply boosted water desalination solutions.Desalination is a capital-intensive process that demands considerable energy,predominantly sourced fromfossil fuels worldwide,posing a significant carbon footprint risk.HDH is a very efficient desalination method suitable for remote areas with moderate freshwater requirements for domestic and agricultural usage.Several operational and maintenance concerns are to blame.The flow and thermal balances of humidifiers and dehumidifiers under the right conditions are crucial for system efficiency.These systems comprise a humidifier and dehumidifier,energy foundations for space or process heating and electricity generation,fluid transfer or efficiency enhancement accessories,and measurement-control devices.All technologies that enhance the performance of HDH systems are elucidated in this work.These are utilizing efficient components,renewable energy,heat recovery via multi-effect and multi-stage processes,waste heat-powered,and accelerating humidification and dehumidification processes through pressure variation or employing heat pumps,in addition to exergy and economical analyses.According to the present work,the seawater HDH system is feasible for freshwater generation.Regarding economics and gain output ratio,humidification–dehumidification is a viable approach for decentralized small-scale freshwater production applications,but it needs significant refinement.Systemproductivity of fresh water is much higher with integrated solar water heating than with solar air heating.The HDH offers the lowest water yield cost per liter and ideal system productivity when paired with a heat pump.The suggested changes aim to enhance system and process efficiency,reducing electrical energy consumption and cost-effective,continuous,decentralized freshwater production.This thorough analysis establishes a foundation for future research on energy and exergy cycles based on humidification and dehumidification.展开更多
Chip-based flow-through PCR implements the PCR as a continuous process for nucleic acid analytics. The sample is transported in a winding channel through temperature zones required for denaturation, annealing and exte...Chip-based flow-through PCR implements the PCR as a continuous process for nucleic acid analytics. The sample is transported in a winding channel through temperature zones required for denaturation, annealing and extension. Main fields of application are the monitoring of continuous processes for rapid identification of contaminants and quality control as well as high throughput screening of cells or microorganisms. A modular arrangement with five heating zones for flow-through PCR is discussed and evaluated. The special heater arrangement allows the implementation of up to 40 cycles on the footprint of a microscope slide, which is placed on top ofa 5 zones heating plate. Liquid/liquid two phase flow of PCR reaction mixture and mineral oil have been applied to create a segmented flow process scheme. In that way, the developed system may provide flow-through PCR as a unit operation for the droplet based microfluidics platform. The single use of disposable devices is commonly preferred due to the sensitivity of the PCR process to contaminations. All-glass microfluidic chips and disposable chip devices, made from polycarbonate as a replication with identically geometry, have been fabricated and tested. For the first time, microchannel geometries with nearly circular profile developed by all-glass technology have been transferred to mass fabrication by injection compression molding. Both devices have been successfully applied for the detection of the tumor suppressor gene p53. Although product yield and selectivity of the amplification process do not depend on the chip material, a well defined, reliable segmented flow regime could only be realized in the all-glass chip.展开更多
Zinc and its compounds, alloys and composites play an important role in the modern day world and find application in almost every aspect that can improve the quality of our lives. This ranges from supplements and phar...Zinc and its compounds, alloys and composites play an important role in the modern day world and find application in almost every aspect that can improve the quality of our lives. This ranges from supplements and pharmaceuticals that are meant to improve our health and wellbeing to additives meant to guard or reduce corrosion in metals. However, over the past several years, a new area of technology has been garnering a great deal of attention and has made use of zinc and its compounds. This is with reference to paper-based microfluidic technology that offers several advantages and that keeps expanding in the amount of applications it covers. In this paper, a review is offered for the applications that have used zinc or zinc compounds in paper-based microfluidic devices.展开更多
BACKGROUND Giant hiatal hernias still pose a major challenge to digestive surgeons,and their repair is sometimes a highly complex task.This is usually performed by laparoscopy,while the role of the thoracoscopic appro...BACKGROUND Giant hiatal hernias still pose a major challenge to digestive surgeons,and their repair is sometimes a highly complex task.This is usually performed by laparoscopy,while the role of the thoracoscopic approach has yet to be clearly defined.AIM To preoperatively detect patients with a giant hiatal hernia in whom it would not be safe to perform laparoscopic surgery and who,therefore,would be candidates for a thoracoscopic approach.METHODS In the present study,using imaging test we preoperatively simulate the field of vision of the camera and the working area(instrumental access)that can be obtained in each patient when the laparoscopic approach is used.RESULTS From data obtained,we can calculate the access angles that will be obtained in a preoperative computerised axial tomography coronal section,according to the location of the trocar.We also provide the formula for performing the angle calculations If the trocars are placed in loss common situations,thus enabling us to determine the visibility and manoeuvrability for any position of the trocars.CONCLUSION The working area determines the cases in which we can operate safely and those in which certain areas of the hernia cannot be accessed,which is when the thoracoscopic approach would be safer.展开更多
A high quality factor is preferred for a microresonator sensor to improve the sensitivity and resolution. In this paper we systematically investigate the performance of the microcantilever in different resonance modes...A high quality factor is preferred for a microresonator sensor to improve the sensitivity and resolution. In this paper we systematically investigate the performance of the microcantilever in different resonance modes, which are the first three flexural modes, the first lateral mode, and the first and the second torsional modes. An aluminum nitride-based piezoelectric cantilever is fabricated and tested under controlled pressure from an ultra-high vacuum to a normal atmosphere, using a custom-built vacuum chamber. From the experiment results, it can be seen that the torsional modes exhibit better quality factors than those of the flexural and lateral ones. Finally, an analytical model for the air damping characteristics of the torsional mode cantilever is derived and verified by comparing with experimental results.展开更多
BACKGROUND Dietary methyl donors might influence DNA methylation during carcinogenesis of colorectal cancer(CRC).However,whether the influence of methyl donor intake is modified by polymorphisms in such epigenetic reg...BACKGROUND Dietary methyl donors might influence DNA methylation during carcinogenesis of colorectal cancer(CRC).However,whether the influence of methyl donor intake is modified by polymorphisms in such epigenetic regulators is still unclear.AIM To improve the current understanding of the molecular basis of CRC.METHODS A literature search in the Medline database,Reference Citation Analysis(https://www.referencecitationanalysis.com/),and manual reference screening were performed to identify observational studies published from inception to May 2022.RESULTS A total of fourteen case-control studies and five cohort studies were identified.These studies included information on dietary methyl donors,dietary components that potentially modulate the bioavailability of methyl groups,genetic variants of methyl metabolizing enzymes,and/or markers of CpG island methylator phenotype and/or microsatellite instability,and their possible interactions on CRC risk.CONCLUSION Several studies have suggested interactions between methylenetetrahydrofolate reductase polymorphisms,methyl donor nutrients(such as folate)and alcohol on CRC risk.Moreover,vitamin B6,niacin,and alcohol may affect CRC risk through not only genetic but also epigenetic regulation.Identification of specific mechanisms in these interactions associated with CRC may assist in developing targeted prevention strategies for individuals at the highest risk of developing CRC.展开更多
AIM:The generation and characterization of a human embryonic stem cell (hESC) line stably expressing red fluorescent mCherry protein. METHODS:Lentiviral transduction of a ubiquitously-expressed human EF-1α promoter d...AIM:The generation and characterization of a human embryonic stem cell (hESC) line stably expressing red fluorescent mCherry protein. METHODS:Lentiviral transduction of a ubiquitously-expressed human EF-1α promoter driven mCherry transgene was performed in MEL2 hESC. Red fluore-scence was assessed by immunofluorescence and flow cytometry. Pluripotency of stably transduced hESC was determined by immunofluorescent pluripotency marker expression, flow cytometry, teratoma assays andembryoid body-based differentiation followed by reverse transcriptase-polymerase chain reaction. Quantification of cell motility and survival was performed with time lapse microscopy. RESULTS:Constitutively fluorescently-labeled hESCs are useful tools for facile in vitro and in vivo tracking of survival, motility and cell spreading on various surfaces before and after differentiation. Here we describe the generation and characterization of a hESC line (MEL2) stably expressing red fluorescent protein, mCherry. This line was generated by random integration of a fluorescent protein-expressing cassette, driven by the ubiquitously-expressed human EF-1α promoter. Stably transfected MEL2-mCherry hESC were shown to express pluripo-tency markers in the nucleus (POU5F1/OCT4, NANOG and SOX2) and on the cell surface (SSEA4, TRA1-60 and TG30/CD9) and were shown to maintain a normal karyotype in long-term (for at least 35 passages) culture. MEL2-mCherry hESC further readily differentiated into representative cell types of the three germ layers in embryoid body and teratoma based assays and, importantly, maintained robust mCherry expression throughout differentiation. The cell line was next adapted to singlecell passaging, rendering it compatible with numerous bioengineering applications such as measurement of cell motility and cell spreading on various protein modified surfaces, quantification of cell attachment to nanoparticles and rapid estimation of cell survival. CONCLUSION:The MEL2-mCherry hESC line conforms to the criteria of bona fide pluripotent stem cells and maintains red fluorescence throughout differentiation, making it a useful tool for bioengineering and in vivo tracking experiments.展开更多
A new formulation for tracking multiple particles in slow viscous flow for microfluidic applications is presented.The method employs the manipulation of the boundary element matrices so that finally a system of equati...A new formulation for tracking multiple particles in slow viscous flow for microfluidic applications is presented.The method employs the manipulation of the boundary element matrices so that finally a system of equations is obtained relating the rigid body velocities of the particle to the forces applied on the particle.The formulation is specially designed for particle trajectory tracking and involves successive matrix multiplications for which SMP(Symmetric multiprocessing)parallelisation is applied.It is observed that present formulation offers an efficient numerical model to be used for particle tracking and can easily be extended for multiphysics simulations in which several physics involved.展开更多
AM （additive manufacturing） of metal parts becomes increasingly important in many industrial fields. However, currently used AM processes like laser melting or electron beam melting are quite complex and expensive. ...AM （additive manufacturing） of metal parts becomes increasingly important in many industrial fields. However, currently used AM processes like laser melting or electron beam melting are quite complex and expensive. The extrusion based AM technology for dense metal components （Composite Extrusion Modelling-CEM）, is characterised by an easy handling and cost efficiency in comparison to powder based processes. The CEM process contains two steps, the additive manufacturing of the green parts and the consecutive sintering. The additive manufacturing of green parts is carried out in a thermally controlled extrusion process. The standard metal injection moulding material with a high proportion of metal and thermoplastic binder is deposited in layers by a heated nozzle. In this way overhangs and bridge structures can be realised. The quality of the green parts that were manufactured with the specifically developed extruder corresponds to typical Fused Deposition Modelling parts. In case the surfaces need to be smooth the green parts can be mechanically post-processed before going through the debinding and sintering process.展开更多
A theoretical model based on energy conversation is constructed to characterize the contracting behavior of the nonconductive droplet actuated by the dielectric effect in an immiscible dielectric liquid. To verify the...A theoretical model based on energy conversation is constructed to characterize the contracting behavior of the nonconductive droplet actuated by the dielectric effect in an immiscible dielectric liquid. To verify the theory, COMSOL is employed to simulate the evolution of the droplet based on dielectrowetting, and a measurement platform is established to monitor the change process of the droplet profile. The contact angle and the height of the droplet increase linearly up to 48° and 2.03 mm respectively when U ranges from 55 V to 160 V, while the droplet remained stationary when U < 55 V.The relative experimental results coincide with the prediction of theory and the simulation analysis.展开更多
The effect of phase-breaking process on the ac response of a coupled double quantum dot is studied in this paper based on the nonequilibrium Green function formalism. A general expression is derived for the ac current...The effect of phase-breaking process on the ac response of a coupled double quantum dot is studied in this paper based on the nonequilibrium Green function formalism. A general expression is derived for the ac current in the presence of electron-phonon interaction. The ac conductance is numerically computed and the results are compared with those in [Anatram M P and Datta S 1995 Phys. Rev. B 51 7632]. Our results reveal that the inter-dot electron tunnelling interplays with that between dots and electron reservoirs, and contributes prominently to the ac current when inter-dot tunnelling coupling is much larger than the tunnelling coupling between dots and electron reservoirs. In addition, the phase-breaking process is found to have a significant effect on the ac transport through the coupled double dot.展开更多
BACKGROUND Giant hernias present a significant challenge for digestive surgeons.The approach taken(laparoscopic vs thoracoscopic)depends largely on the preferences and skills of each surgeon,although in most cases tod...BACKGROUND Giant hernias present a significant challenge for digestive surgeons.The approach taken(laparoscopic vs thoracoscopic)depends largely on the preferences and skills of each surgeon,although in most cases today the laparoscopic approach is preferred.AIM To determine whether patients presenting inadequate laparoscopic access to the intrathoracic hernial sac obtain poorer postoperative results than those with no such problem,in order to assess the need for a thoracoscopic approach.METHODS For the retrospective series of patients treated in our hospital for hiatal hernia(n=112),we calculated the laparoscopic field of view and the working area accessible to surgical instruments,by means of preoperative imaging tests,to assess the likely outcome for cases inaccessible to laparoscopy.RESULTS Patients with giant hiatal hernias for whom a preoperative calculation suggested that the laparoscopic route would not access all areas of the intrathoracic sac presented higher rates of perioperative complications and recurrence during follow-up than those for whom laparoscopy was unimpeded.The difference was statistically significant.Moreover,the insertion of mesh did not improve results for the non-accessible group.CONCLUSION For patients with giant hiatal hernias,it is essential to conduct a preoperative evaluation of the angle of vision and the working area for surgery.When parts of the intrathoracic sac are inaccessible laparoscopically,the thoracoscopic approach should be considered.展开更多
We have investigated the structures, stabilities and magnetism of NiAln and CuAln (n = 1 - 9) clusters systematically by using first-principles density functional theory. Our calculated results indicate that most of t...We have investigated the structures, stabilities and magnetism of NiAln and CuAln (n = 1 - 9) clusters systematically by using first-principles density functional theory. Our calculated results indicate that most of the ground state structures for the Al clusters doped with one nickel or copper atom are different from those of the corresponding pure Al clusters. NiAln and CuAln (n = 1 - 9) cluster ions have similar geometrical configurations to the corresponding neutral clusters, except for positive NiAl9 ion. The magnetic moments of NiAln (n = odd number) and CuAln (n = even number) cluster anions, neutrals and cations are 0, 1 μB, and 2 μB, respectively. The magnetic moments of NiAl4 and NiAl6 cluster anions, neutrals and cations are associated with 1 μB, 2 μB, and 3 μB, respectively. NiAl2, NiAl8 and CuAln (n = odd number) clusters do not have any net magnetic moment. But, NiAl2 and NiAl8 cluster ions have the net magnetic moment of 1 μB.展开更多
Chronic wounds are wounds that are difficult to heal or do not follow the normal healing process.These include pressure ulcers,diabetic ulcers,venous ulcers,and arterial incomplete ulcers.Unlike acute wounds,chronic w...Chronic wounds are wounds that are difficult to heal or do not follow the normal healing process.These include pressure ulcers,diabetic ulcers,venous ulcers,and arterial incomplete ulcers.Unlike acute wounds,chronic wounds are often difficult to heal or even do not heal.Its pathogenesis involves many factors;bacterial infection is the main cause of chronic wound.With the increase in population aging,the incidence of chronic wounds has become a critical issue in the current medical and health field.Management of chronic wounds is faced with the problems of long treatment time,difficulty,high cost,repeated attacks and high disability rate,which seriously threaten patients'ability to take care of themselves in normal life and cause a heavy burden to individuals,families and society.Over the past few years,the development of antibacterial hydrogels for the treatment of bacterial infections has received a lot of attention.Since antibacterial hydrogels not only have the mechanical properties of hydrogels,high biocompatibility and adjustable functional structure,but also have excellent antibacterial properties,they may be an ideal dressing to solve the problem of chronic wound healing.This article introduces the types of chronic wounds,their healing characteristics,and the challenges faced in treating chronic wounds.It classifies antimicrobial hydrogels based on their antimicrobial modes and further discusses the advancements in smart antimicrobial hydrogels along with the benefits and obstacles of using antimicrobial hydrogels in the treatment of chronic wounds.This article also explores the development directions of antimicrobial hydrogels for chronic wound management.展开更多
Two-dimensional(2D)MXene materials are promising candidates for the development of heterogeneous materials,yet deciphering structural impacts on their inherent physical properties poses significant challenges.We intro...Two-dimensional(2D)MXene materials are promising candidates for the development of heterogeneous materials,yet deciphering structural impacts on their inherent physical properties poses significant challenges.We introduce structurally regulated 2D Ti_(3)C_(2)nanosheets that were fabricated using high intensity focused ultrasound(HIFU)method.These nanosheets were easily produced in large quantities with a high yield of 94.4%and exhibited excellent photothermal and electrochemical catalytic properties.By utilizing this monolayer H-Ti_(3)C_(2)(HIFU-treated Ti_(3)C_(2)),the heterogeneous integration exhibited promising performance in subsequent applications.By integrating with a hydrogel matrix(H-Ti_(3)C_(2),0.1 wt.%),it demonstrated a photothermal conversion efficiency reaching 43.08%,and the maximum temperature increased by 48.14%under near-infrared(NIR)irradiation.Additionally,these 2D nanosheets were also utilized in fabricating electrochemical sensors to evaluate electrochemical-catalytic capabilities.Notably,it confirmed that the electrocatalytic activity of heterogeneous Au/H-Ti_(3)C_(2)in electrochemical dopamine(DA)detection,and it proved the exhibition of sensitivity(0.012μA/μM),low detection limit(0.15μM),and excellent anti-interference performance and stability.The enhanced activity was ascribed to synergistic effect of Au and the increased number of accessible active sites on the nanosheets.This work not only sheds light on the structure-property relationship of 2D Ti_(3)C_(2)but also broadens the application scope of typical dimensional materials for controlling and producing in biological and sensing applications.展开更多
A distributed feedback(DFB) semiconductor laser with three phase shifts based on reconstruction equivalent chirp(REC) technology is proposed and investigated numerically.With the combination of multiple phase shifts a...A distributed feedback(DFB) semiconductor laser with three phase shifts based on reconstruction equivalent chirp(REC) technology is proposed and investigated numerically.With the combination of multiple phase shifts and corrugation pitch modulated(CPM) structure,we also propose a novel and more complex structure named dual CPM,which has a flatter light power distribution along the laser cavity compared with the true double phase shifts DFB laser diode(LD),while the P-I curves are nearly the same.The proposed dual CPM structure is also designed and analyzed based on REC technology.The simulation results show that,the DFB semiconductor laser with complex structure such as phase shifts,or even arbitrary variation of the grating period can be achieved equivalently and easily by changing the sampling structure.But its external characteristics are almost the same as those DFB lasers with true phase shifts,or true arbitrary variation of the grating period.The key advantage of the REC technology is that it varies only the sampling structure and keeps the seed grating(actual grating in sampling structure) period constant.So its fabrication needs only low-cost and standard holographic exposure technology.Therefore we believe this method can achieve the high-end and low-cost DFB LD for mass production.展开更多
This paper reported a study on a flexible liquid metal coil (LMC) for electromagnetic collection from the transmission line for self-powered sensor and electromagnetic generation for wireless charging of cellular tele...This paper reported a study on a flexible liquid metal coil (LMC) for electromagnetic collection from the transmission line for self-powered sensor and electromagnetic generation for wireless charging of cellular telephone. The room temperature liquid metal of Galinstan was perfused to elastic silicone tube, which is then terminated with galliumplated copper wire. The asprepared liquid metal wire can sustain stretching, twisting, and bending with large deformation, and has a good electrical contact stability with the external circuit. The LMC based magnetic energy harvester was then designed and demonstrated to collect the magnetic field energy induced by a wire carrying alternating current. The power of 260 mW was obtained for the wire carrying current of 10 A. The flexible toroidal inductor was fabricated and tested for magnetic energy harvesting. The flexible spiralshaped LMC was also designed and demonstrated to power cellular telephone through wireless charging. The present study opens the way for further applications of elastic LMC in electromagnetic energy harvesting and charging.展开更多
In this work,we report a novel soft diffractive micro-optics,called‘microscale kinoform phase-type lens(micro-KPL)’,which is fabricated by femtosecond laser direct writing(FsLDW)using bovine serum albumin(BSA)as bui...In this work,we report a novel soft diffractive micro-optics,called‘microscale kinoform phase-type lens(micro-KPL)’,which is fabricated by femtosecond laser direct writing(FsLDW)using bovine serum albumin(BSA)as building blocks and flexible polydimethylsiloxane(PDMS)slices as substrates.By carefully optimizing various process parameters of FsLDW(e.g.,average laser power density,scanning step,exposure time on a single point and protein concentration),the as-formed protein micro-KPLs exhibit excellent surface quality,well-defined three-dimensional(3D)geometry and distinctive optical properties,even in relatively harsh operation environments(for instance,in strong acid or base).Laser shaping,imaging and other optical performances can be easily achieved.More importantly,micro-KPLs also have unique flexible and stretchable properties as well as good biocompatibility and biodegradability.Therefore,such protein hydrogel-based micro-optics may have great potential applications,such as in flexible and stretchable photonics and optics,soft integrated optical microsystems and bioimplantable devices.展开更多
A kind of PH gradient microfluidic chips through soft-lithography microfabrication for isoelectric focusing(IEF)and high performance liquid chromatography(HPLC)is introduced here.These pH gradient chips have the advan...A kind of PH gradient microfluidic chips through soft-lithography microfabrication for isoelectric focusing(IEF)and high performance liquid chromatography(HPLC)is introduced here.These pH gradient chips have the advan-tages such as easy fabrication,controllable pH range and precision,isoelectric focusing and separation at the same time,low voltage for isoelectric focusing,and time stable pH gradient.This method has potential application to sample preparation,separation and analysis of microfluidic chips.展开更多
Analyzing undiluted whole human blood is a challenge due to its complex composition of hematopoietic cellular populations,nucleic acids,metabolites,and proteins.We present a novel multi-functional microfluidic acousti...Analyzing undiluted whole human blood is a challenge due to its complex composition of hematopoietic cellular populations,nucleic acids,metabolites,and proteins.We present a novel multi-functional microfluidic acoustic streaming platform that enables sorting,enrichment and in situ identification of cellular subsets from whole blood.This single device platform,based on lateral cavity acoustic transducers(LCAT),enables(1)the sorting of undiluted donor whole blood into its cellular subsets(platelets,RBCs,and WBCs),(2)the enrichment and retrieval of breast cancer cells(MCF-7)spiked in donor whole blood at rare cell relevant concentrations(10 mL^(−1)),and(3)on-chip immunofluorescent labeling for the detection of specific target cellular populations by their known marker expression patterns.Our approach thus demonstrates a compact system that integrates upstream sample processing with downstream separation/enrichment,to carry out multi-parametric cell analysis for blood-based diagnosis and liquid biopsy blood sampling.展开更多
文摘The deficiency of potable water resources and energy supply is emerging as a significant and concerning obstacle to sustainable development.Solar and waste heat-powered humidification dehumidification(HDH)desalination systems become essential due to the severe impacts of global warming and water shortages.This problem highlights the need to apply boosted water desalination solutions.Desalination is a capital-intensive process that demands considerable energy,predominantly sourced fromfossil fuels worldwide,posing a significant carbon footprint risk.HDH is a very efficient desalination method suitable for remote areas with moderate freshwater requirements for domestic and agricultural usage.Several operational and maintenance concerns are to blame.The flow and thermal balances of humidifiers and dehumidifiers under the right conditions are crucial for system efficiency.These systems comprise a humidifier and dehumidifier,energy foundations for space or process heating and electricity generation,fluid transfer or efficiency enhancement accessories,and measurement-control devices.All technologies that enhance the performance of HDH systems are elucidated in this work.These are utilizing efficient components,renewable energy,heat recovery via multi-effect and multi-stage processes,waste heat-powered,and accelerating humidification and dehumidification processes through pressure variation or employing heat pumps,in addition to exergy and economical analyses.According to the present work,the seawater HDH system is feasible for freshwater generation.Regarding economics and gain output ratio,humidification–dehumidification is a viable approach for decentralized small-scale freshwater production applications,but it needs significant refinement.Systemproductivity of fresh water is much higher with integrated solar water heating than with solar air heating.The HDH offers the lowest water yield cost per liter and ideal system productivity when paired with a heat pump.The suggested changes aim to enhance system and process efficiency,reducing electrical energy consumption and cost-effective,continuous,decentralized freshwater production.This thorough analysis establishes a foundation for future research on energy and exergy cycles based on humidification and dehumidification.
基金This work was funded by the German Federal Ministry of Education and Research (BMBF), reference number 16SV3529, project MINAMED.
文摘Chip-based flow-through PCR implements the PCR as a continuous process for nucleic acid analytics. The sample is transported in a winding channel through temperature zones required for denaturation, annealing and extension. Main fields of application are the monitoring of continuous processes for rapid identification of contaminants and quality control as well as high throughput screening of cells or microorganisms. A modular arrangement with five heating zones for flow-through PCR is discussed and evaluated. The special heater arrangement allows the implementation of up to 40 cycles on the footprint of a microscope slide, which is placed on top ofa 5 zones heating plate. Liquid/liquid two phase flow of PCR reaction mixture and mineral oil have been applied to create a segmented flow process scheme. In that way, the developed system may provide flow-through PCR as a unit operation for the droplet based microfluidics platform. The single use of disposable devices is commonly preferred due to the sensitivity of the PCR process to contaminations. All-glass microfluidic chips and disposable chip devices, made from polycarbonate as a replication with identically geometry, have been fabricated and tested. For the first time, microchannel geometries with nearly circular profile developed by all-glass technology have been transferred to mass fabrication by injection compression molding. Both devices have been successfully applied for the detection of the tumor suppressor gene p53. Although product yield and selectivity of the amplification process do not depend on the chip material, a well defined, reliable segmented flow regime could only be realized in the all-glass chip.
文摘Zinc and its compounds, alloys and composites play an important role in the modern day world and find application in almost every aspect that can improve the quality of our lives. This ranges from supplements and pharmaceuticals that are meant to improve our health and wellbeing to additives meant to guard or reduce corrosion in metals. However, over the past several years, a new area of technology has been garnering a great deal of attention and has made use of zinc and its compounds. This is with reference to paper-based microfluidic technology that offers several advantages and that keeps expanding in the amount of applications it covers. In this paper, a review is offered for the applications that have used zinc or zinc compounds in paper-based microfluidic devices.
文摘BACKGROUND Giant hiatal hernias still pose a major challenge to digestive surgeons,and their repair is sometimes a highly complex task.This is usually performed by laparoscopy,while the role of the thoracoscopic approach has yet to be clearly defined.AIM To preoperatively detect patients with a giant hiatal hernia in whom it would not be safe to perform laparoscopic surgery and who,therefore,would be candidates for a thoracoscopic approach.METHODS In the present study,using imaging test we preoperatively simulate the field of vision of the camera and the working area(instrumental access)that can be obtained in each patient when the laparoscopic approach is used.RESULTS From data obtained,we can calculate the access angles that will be obtained in a preoperative computerised axial tomography coronal section,according to the location of the trocar.We also provide the formula for performing the angle calculations If the trocars are placed in loss common situations,thus enabling us to determine the visibility and manoeuvrability for any position of the trocars.CONCLUSION The working area determines the cases in which we can operate safely and those in which certain areas of the hernia cannot be accessed,which is when the thoracoscopic approach would be safer.
文摘A high quality factor is preferred for a microresonator sensor to improve the sensitivity and resolution. In this paper we systematically investigate the performance of the microcantilever in different resonance modes, which are the first three flexural modes, the first lateral mode, and the first and the second torsional modes. An aluminum nitride-based piezoelectric cantilever is fabricated and tested under controlled pressure from an ultra-high vacuum to a normal atmosphere, using a custom-built vacuum chamber. From the experiment results, it can be seen that the torsional modes exhibit better quality factors than those of the flexural and lateral ones. Finally, an analytical model for the air damping characteristics of the torsional mode cantilever is derived and verified by comparing with experimental results.
基金The Basque Government(BIOMICs Research Group,MICROFLUIDICs&BIOMICs Cluster of the University of the Basque Country UPV/EHU),No.IT1633-22.
文摘BACKGROUND Dietary methyl donors might influence DNA methylation during carcinogenesis of colorectal cancer(CRC).However,whether the influence of methyl donor intake is modified by polymorphisms in such epigenetic regulators is still unclear.AIM To improve the current understanding of the molecular basis of CRC.METHODS A literature search in the Medline database,Reference Citation Analysis(https://www.referencecitationanalysis.com/),and manual reference screening were performed to identify observational studies published from inception to May 2022.RESULTS A total of fourteen case-control studies and five cohort studies were identified.These studies included information on dietary methyl donors,dietary components that potentially modulate the bioavailability of methyl groups,genetic variants of methyl metabolizing enzymes,and/or markers of CpG island methylator phenotype and/or microsatellite instability,and their possible interactions on CRC risk.CONCLUSION Several studies have suggested interactions between methylenetetrahydrofolate reductase polymorphisms,methyl donor nutrients(such as folate)and alcohol on CRC risk.Moreover,vitamin B6,niacin,and alcohol may affect CRC risk through not only genetic but also epigenetic regulation.Identification of specific mechanisms in these interactions associated with CRC may assist in developing targeted prevention strategies for individuals at the highest risk of developing CRC.
基金the Australian Stem CellCentre (ASCC), UQ AIBN Challenge Grant Scheme for financial supportthe ASCC’s StemCore pluripotent stem cell core facility for the provision of hES cell lines and logistical support
文摘AIM:The generation and characterization of a human embryonic stem cell (hESC) line stably expressing red fluorescent mCherry protein. METHODS:Lentiviral transduction of a ubiquitously-expressed human EF-1α promoter driven mCherry transgene was performed in MEL2 hESC. Red fluore-scence was assessed by immunofluorescence and flow cytometry. Pluripotency of stably transduced hESC was determined by immunofluorescent pluripotency marker expression, flow cytometry, teratoma assays andembryoid body-based differentiation followed by reverse transcriptase-polymerase chain reaction. Quantification of cell motility and survival was performed with time lapse microscopy. RESULTS:Constitutively fluorescently-labeled hESCs are useful tools for facile in vitro and in vivo tracking of survival, motility and cell spreading on various surfaces before and after differentiation. Here we describe the generation and characterization of a hESC line (MEL2) stably expressing red fluorescent protein, mCherry. This line was generated by random integration of a fluorescent protein-expressing cassette, driven by the ubiquitously-expressed human EF-1α promoter. Stably transfected MEL2-mCherry hESC were shown to express pluripo-tency markers in the nucleus (POU5F1/OCT4, NANOG and SOX2) and on the cell surface (SSEA4, TRA1-60 and TG30/CD9) and were shown to maintain a normal karyotype in long-term (for at least 35 passages) culture. MEL2-mCherry hESC further readily differentiated into representative cell types of the three germ layers in embryoid body and teratoma based assays and, importantly, maintained robust mCherry expression throughout differentiation. The cell line was next adapted to singlecell passaging, rendering it compatible with numerous bioengineering applications such as measurement of cell motility and cell spreading on various protein modified surfaces, quantification of cell attachment to nanoparticles and rapid estimation of cell survival. CONCLUSION:The MEL2-mCherry hESC line conforms to the criteria of bona fide pluripotent stem cells and maintains red fluorescence throughout differentiation, making it a useful tool for bioengineering and in vivo tracking experiments.
文摘A new formulation for tracking multiple particles in slow viscous flow for microfluidic applications is presented.The method employs the manipulation of the boundary element matrices so that finally a system of equations is obtained relating the rigid body velocities of the particle to the forces applied on the particle.The formulation is specially designed for particle trajectory tracking and involves successive matrix multiplications for which SMP(Symmetric multiprocessing)parallelisation is applied.It is observed that present formulation offers an efficient numerical model to be used for particle tracking and can easily be extended for multiphysics simulations in which several physics involved.
文摘AM （additive manufacturing） of metal parts becomes increasingly important in many industrial fields. However, currently used AM processes like laser melting or electron beam melting are quite complex and expensive. The extrusion based AM technology for dense metal components （Composite Extrusion Modelling-CEM）, is characterised by an easy handling and cost efficiency in comparison to powder based processes. The CEM process contains two steps, the additive manufacturing of the green parts and the consecutive sintering. The additive manufacturing of green parts is carried out in a thermally controlled extrusion process. The standard metal injection moulding material with a high proportion of metal and thermoplastic binder is deposited in layers by a heated nozzle. In this way overhangs and bridge structures can be realised. The quality of the green parts that were manufactured with the specifically developed extruder corresponds to typical Fused Deposition Modelling parts. In case the surfaces need to be smooth the green parts can be mechanically post-processed before going through the debinding and sintering process.
基金supported by the National Natural Science Foundation of China(Grant No.61775102)the Youth Program of the National Natural Science Foundation of China(Grant No.61905117).
文摘A theoretical model based on energy conversation is constructed to characterize the contracting behavior of the nonconductive droplet actuated by the dielectric effect in an immiscible dielectric liquid. To verify the theory, COMSOL is employed to simulate the evolution of the droplet based on dielectrowetting, and a measurement platform is established to monitor the change process of the droplet profile. The contact angle and the height of the droplet increase linearly up to 48° and 2.03 mm respectively when U ranges from 55 V to 160 V, while the droplet remained stationary when U < 55 V.The relative experimental results coincide with the prediction of theory and the simulation analysis.
文摘The effect of phase-breaking process on the ac response of a coupled double quantum dot is studied in this paper based on the nonequilibrium Green function formalism. A general expression is derived for the ac current in the presence of electron-phonon interaction. The ac conductance is numerically computed and the results are compared with those in [Anatram M P and Datta S 1995 Phys. Rev. B 51 7632]. Our results reveal that the inter-dot electron tunnelling interplays with that between dots and electron reservoirs, and contributes prominently to the ac current when inter-dot tunnelling coupling is much larger than the tunnelling coupling between dots and electron reservoirs. In addition, the phase-breaking process is found to have a significant effect on the ac transport through the coupled double dot.
文摘BACKGROUND Giant hernias present a significant challenge for digestive surgeons.The approach taken(laparoscopic vs thoracoscopic)depends largely on the preferences and skills of each surgeon,although in most cases today the laparoscopic approach is preferred.AIM To determine whether patients presenting inadequate laparoscopic access to the intrathoracic hernial sac obtain poorer postoperative results than those with no such problem,in order to assess the need for a thoracoscopic approach.METHODS For the retrospective series of patients treated in our hospital for hiatal hernia(n=112),we calculated the laparoscopic field of view and the working area accessible to surgical instruments,by means of preoperative imaging tests,to assess the likely outcome for cases inaccessible to laparoscopy.RESULTS Patients with giant hiatal hernias for whom a preoperative calculation suggested that the laparoscopic route would not access all areas of the intrathoracic sac presented higher rates of perioperative complications and recurrence during follow-up than those for whom laparoscopy was unimpeded.The difference was statistically significant.Moreover,the insertion of mesh did not improve results for the non-accessible group.CONCLUSION For patients with giant hiatal hernias,it is essential to conduct a preoperative evaluation of the angle of vision and the working area for surgery.When parts of the intrathoracic sac are inaccessible laparoscopically,the thoracoscopic approach should be considered.
文摘We have investigated the structures, stabilities and magnetism of NiAln and CuAln (n = 1 - 9) clusters systematically by using first-principles density functional theory. Our calculated results indicate that most of the ground state structures for the Al clusters doped with one nickel or copper atom are different from those of the corresponding pure Al clusters. NiAln and CuAln (n = 1 - 9) cluster ions have similar geometrical configurations to the corresponding neutral clusters, except for positive NiAl9 ion. The magnetic moments of NiAln (n = odd number) and CuAln (n = even number) cluster anions, neutrals and cations are 0, 1 μB, and 2 μB, respectively. The magnetic moments of NiAl4 and NiAl6 cluster anions, neutrals and cations are associated with 1 μB, 2 μB, and 3 μB, respectively. NiAl2, NiAl8 and CuAln (n = odd number) clusters do not have any net magnetic moment. But, NiAl2 and NiAl8 cluster ions have the net magnetic moment of 1 μB.
基金supported by grants from the National Key Research and Development Program of China(No.2023YFA0915200,2023YFA0915204)the equipment research and development projects of the Chinese Academy of Sciences(PTYQ2024YZ0010,PTYQ2024BJ0007)the Science and Technology Commission of Shanghai Municipality Project(XTCX-KJ-2024-038).
文摘Chronic wounds are wounds that are difficult to heal or do not follow the normal healing process.These include pressure ulcers,diabetic ulcers,venous ulcers,and arterial incomplete ulcers.Unlike acute wounds,chronic wounds are often difficult to heal or even do not heal.Its pathogenesis involves many factors;bacterial infection is the main cause of chronic wound.With the increase in population aging,the incidence of chronic wounds has become a critical issue in the current medical and health field.Management of chronic wounds is faced with the problems of long treatment time,difficulty,high cost,repeated attacks and high disability rate,which seriously threaten patients'ability to take care of themselves in normal life and cause a heavy burden to individuals,families and society.Over the past few years,the development of antibacterial hydrogels for the treatment of bacterial infections has received a lot of attention.Since antibacterial hydrogels not only have the mechanical properties of hydrogels,high biocompatibility and adjustable functional structure,but also have excellent antibacterial properties,they may be an ideal dressing to solve the problem of chronic wound healing.This article introduces the types of chronic wounds,their healing characteristics,and the challenges faced in treating chronic wounds.It classifies antimicrobial hydrogels based on their antimicrobial modes and further discusses the advancements in smart antimicrobial hydrogels along with the benefits and obstacles of using antimicrobial hydrogels in the treatment of chronic wounds.This article also explores the development directions of antimicrobial hydrogels for chronic wound management.
基金supported by the Chongqing Municipal Natural Science Foundation(No.CSTB2022NSCQ-MSX0113)the National Natural and Science Foundation of China(Nos.52273287 and 82002256)+2 种基金was partially funded by Natural Science Foundation of Heilongjiang Province of China for Excellent Young Scholars(No.YQ2022E020)the Heilongjiang Touyan Team(No.HITTY-20190036)the Fundamental Research Funds for the Central Universities(No.AUEA5740202424)。
文摘Two-dimensional(2D)MXene materials are promising candidates for the development of heterogeneous materials,yet deciphering structural impacts on their inherent physical properties poses significant challenges.We introduce structurally regulated 2D Ti_(3)C_(2)nanosheets that were fabricated using high intensity focused ultrasound(HIFU)method.These nanosheets were easily produced in large quantities with a high yield of 94.4%and exhibited excellent photothermal and electrochemical catalytic properties.By utilizing this monolayer H-Ti_(3)C_(2)(HIFU-treated Ti_(3)C_(2)),the heterogeneous integration exhibited promising performance in subsequent applications.By integrating with a hydrogel matrix(H-Ti_(3)C_(2),0.1 wt.%),it demonstrated a photothermal conversion efficiency reaching 43.08%,and the maximum temperature increased by 48.14%under near-infrared(NIR)irradiation.Additionally,these 2D nanosheets were also utilized in fabricating electrochemical sensors to evaluate electrochemical-catalytic capabilities.Notably,it confirmed that the electrocatalytic activity of heterogeneous Au/H-Ti_(3)C_(2)in electrochemical dopamine(DA)detection,and it proved the exhibition of sensitivity(0.012μA/μM),low detection limit(0.15μM),and excellent anti-interference performance and stability.The enhanced activity was ascribed to synergistic effect of Au and the increased number of accessible active sites on the nanosheets.This work not only sheds light on the structure-property relationship of 2D Ti_(3)C_(2)but also broadens the application scope of typical dimensional materials for controlling and producing in biological and sensing applications.
基金supported by the National Natural Science Foundation of China (60877043)the National High-Tech Research & Development Program of China (2007AA03Z417)the New-Century Excellent Talents Supporting Program of the Ministry of Education of China
文摘A distributed feedback(DFB) semiconductor laser with three phase shifts based on reconstruction equivalent chirp(REC) technology is proposed and investigated numerically.With the combination of multiple phase shifts and corrugation pitch modulated(CPM) structure,we also propose a novel and more complex structure named dual CPM,which has a flatter light power distribution along the laser cavity compared with the true double phase shifts DFB laser diode(LD),while the P-I curves are nearly the same.The proposed dual CPM structure is also designed and analyzed based on REC technology.The simulation results show that,the DFB semiconductor laser with complex structure such as phase shifts,or even arbitrary variation of the grating period can be achieved equivalently and easily by changing the sampling structure.But its external characteristics are almost the same as those DFB lasers with true phase shifts,or true arbitrary variation of the grating period.The key advantage of the REC technology is that it varies only the sampling structure and keeps the seed grating(actual grating in sampling structure) period constant.So its fabrication needs only low-cost and standard holographic exposure technology.Therefore we believe this method can achieve the high-end and low-cost DFB LD for mass production.
文摘This paper reported a study on a flexible liquid metal coil (LMC) for electromagnetic collection from the transmission line for self-powered sensor and electromagnetic generation for wireless charging of cellular telephone. The room temperature liquid metal of Galinstan was perfused to elastic silicone tube, which is then terminated with galliumplated copper wire. The asprepared liquid metal wire can sustain stretching, twisting, and bending with large deformation, and has a good electrical contact stability with the external circuit. The LMC based magnetic energy harvester was then designed and demonstrated to collect the magnetic field energy induced by a wire carrying alternating current. The power of 260 mW was obtained for the wire carrying current of 10 A. The flexible toroidal inductor was fabricated and tested for magnetic energy harvesting. The flexible spiralshaped LMC was also designed and demonstrated to power cellular telephone through wireless charging. The present study opens the way for further applications of elastic LMC in electromagnetic energy harvesting and charging.
基金HBS thanks the National Science Foundation of China(Grant No.90923037)the National Basic Research Program of China(973 Program)(Grant No.2011CB013005)for support+1 种基金WFD thanks the National Science Foundation of China(Grant Nos.91123029,61077066,61137001 and 61127010)the 863 Project of China(Grant No.2012AA063302)for financial support.
文摘In this work,we report a novel soft diffractive micro-optics,called‘microscale kinoform phase-type lens(micro-KPL)’,which is fabricated by femtosecond laser direct writing(FsLDW)using bovine serum albumin(BSA)as building blocks and flexible polydimethylsiloxane(PDMS)slices as substrates.By carefully optimizing various process parameters of FsLDW(e.g.,average laser power density,scanning step,exposure time on a single point and protein concentration),the as-formed protein micro-KPLs exhibit excellent surface quality,well-defined three-dimensional(3D)geometry and distinctive optical properties,even in relatively harsh operation environments(for instance,in strong acid or base).Laser shaping,imaging and other optical performances can be easily achieved.More importantly,micro-KPLs also have unique flexible and stretchable properties as well as good biocompatibility and biodegradability.Therefore,such protein hydrogel-based micro-optics may have great potential applications,such as in flexible and stretchable photonics and optics,soft integrated optical microsystems and bioimplantable devices.
文摘A kind of PH gradient microfluidic chips through soft-lithography microfabrication for isoelectric focusing(IEF)and high performance liquid chromatography(HPLC)is introduced here.These pH gradient chips have the advan-tages such as easy fabrication,controllable pH range and precision,isoelectric focusing and separation at the same time,low voltage for isoelectric focusing,and time stable pH gradient.This method has potential application to sample preparation,separation and analysis of microfluidic chips.
基金This work was supported by the NSF Center for Advanced Design and Manufacturing of Integrated Microfluidics(CADMIM)(Award Nos.IIP-1362165 and IIP-1362048)Schlumberger Faculty for the Future Award(Award No.SF-202940)the National Cancer Institute of the National Institutes of Health under award no.P30CA062203.
文摘Analyzing undiluted whole human blood is a challenge due to its complex composition of hematopoietic cellular populations,nucleic acids,metabolites,and proteins.We present a novel multi-functional microfluidic acoustic streaming platform that enables sorting,enrichment and in situ identification of cellular subsets from whole blood.This single device platform,based on lateral cavity acoustic transducers(LCAT),enables(1)the sorting of undiluted donor whole blood into its cellular subsets(platelets,RBCs,and WBCs),(2)the enrichment and retrieval of breast cancer cells(MCF-7)spiked in donor whole blood at rare cell relevant concentrations(10 mL^(−1)),and(3)on-chip immunofluorescent labeling for the detection of specific target cellular populations by their known marker expression patterns.Our approach thus demonstrates a compact system that integrates upstream sample processing with downstream separation/enrichment,to carry out multi-parametric cell analysis for blood-based diagnosis and liquid biopsy blood sampling.
