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This paper conducted an experimental study on the heat transfer performance of pulsating heat pipe (PHP) under three different working fluids: ultrapure water, n-butanol self-rewetting fluid (SRWF), and self-rewetting Fe3O4-nanofluid (SRNF). The effects of filling ratio (FR), heating power, and magnetic field are studied. The results mainly show that the PHP with SRNF under a magnetic field, the start-up time increases, the evaporation section operating temperature increases, and the thermal performance decreases as the filling ratio increases. Increasing the FR, applying SRWF and SRNF can effectively increase the dry-out limit of PHP. At FR = 50 %, the overall thermal performance of PHP is best. In 10–130W, the thermal resistance of the SRWF and the SRNF with/without magnetic field is reduced by 14.5 %–27.8 %, 27.6 %–47.9 %, and 4.2 %–24.8 %, respectively, compared with that of ultrapure water. Similarly, compared without a magnetic field, the thermal resistance of SRNF with a magnetic field is reduced by 14.0 %–35.1 %. At FR = 50 %, the heat transfer performance of SRNF-PHP is best with a magnetic field. When the input power is 130W, the effective heat transfer coefficient keff is 5967.6 W/m∙ K, approximately 13.92 times greater than copper.

The deterministic lateral displacement (DLD) method has gradually moved beyond the separation of spherical rigid particles and has been successfully applied to the field of biological cells, especially to the separation of disc-shaped flexible erythrocytes. Different shapes of micropillars in the DLD device significantly affect the sorting performance of erythrocytes. We investigated the effect of the flow field in the gap of micropillars of different shapes (circular, triangular, I-shaped) on the behavior of erythrocyte tumbling motion. The simulation results showed that in the I-shaped pillar DLD device, compared with the circular and triangular pillars, the erythrocytes exhibited a stable and continuous flipping motion during the movement along the array offset direction, which enabled the effective separation size to be maintained at a high level. In addition, the formula for calculating the critical diameter of the I-shaped pillar DLD array for separating erythrocytes was obtained by fitting, which provides strong support for a more efficient design of the I-shaped pillar DLD device dedicated to erythrocyte sorting.

Abstract Our previous study has announced that phosphorylated microtubule-associated protein 4 (p-MAP4) accelerated keratinocytes migration and proliferation under hypoxia through depolymerizing microtubules. However, p-MAP4 should exhibit inhibitory effects on wound healing, for it also impaired mitochondria. Thus, figuring out the outcome of p-MAP4 after it impaired mitochondria and how the outcome influenced wound healing were far-reaching significance. Herein, the results revealed that p-MAP4 might undergo self-degradation through autophagy in hypoxic keratinocytes. Next, p-MAP4 activated mitophagy which was unobstructed and was also the principal pathway of its self-degradation triggered by hypoxia. Moreover, both Bcl-2 homology 3 (BH3) and LC3 interacting region (LIR) domains had been verified in MAP4, and they endowed MAP4 with the capability to synchronously function as a mitophagy initiator and a mitophagy substrate receptor. And, mutating any one of them ruined hypoxia-induced self-degradation of p-MAP4, resulting in destroyed proliferation and migration responses of keratinocytes to hypoxia. Our findings unviewed that p-MAP4 experienced mitophagy-associated self-degradation through utilizing its BH3 and LIR domains under hypoxia. As a result, the mitophagy-associated self-degradation of p-MAP4 guaranteed the migration and proliferation responses of keratinocytes to hypoxia. Together, this research provided a bran-new pattern of proteins in regulating wound healing, and offered a new direction for intervening wound healing.

Fuel droplet evaporation is essential to the generation of flammable mixtures in thermal engines. Generally, liquid fuel is injected directly into the hot, high-pressure atmosphere to form scattered droplets. Many investigations on droplet evaporation have been conducted with techniques involving the influence of boundaries, such as suspended wires. Ultrasonic levitation is a non-contact and non-destructive technology that can avoid the impact of hanging wire on droplet shape and heat transfer. Besides, it can simultaneously levitate multiple droplets and allow them to associate with each other or be used to study droplet instability behaviors. This paper reviews the influences of the acoustic field on levitated droplets, the evaporation characteristics of acoustically levitated droplets, and the prospects and limitations of ultrasonic suspension methods for droplet evaporation, which can serve as references for relevant studies.

Examining fuel droplet evaporation is crucial for enhancing fuel engine efficiency, conserving energy, and reducing emissions. This study utilizes experimental methods involving ultrasonic standing wave levitation and high-speed cameras to investigate the impact of temperatures and droplet properties, including initial diameter and composition, on the evaporation process. The evaporation behaviors of fuel droplets, like hexadecane and diesel, are documented across a temperature spectrum spanning 150 °C to 550 °C, with an initial droplet equivalent diameter ranging from 0.10 to 0.30 mm. The evaporation rate positively correlates with temperature and may vary by 15% to 71% between hexadecane and diesel droplets.

Enrichment of erythrocytes is a necessary step in the diagnosis of blood diseases. Due to the high deformability and viscosity of erythrocytes, they cannot be regarded as stable point-like solids, so the influence of their deformability on fluid dynamics must be considered. Therefore, by using the special effect of an I-shaped pillar (I-pillar) on erythrocytes, erythrocytes with different deformability can be made to produce different provisional distances in the chip, so as to achieve the separation of the two kinds of erythrocytes. In this study, a microfluidic chip was designed to conduct a control test between erythrocytes stored for a long time and fresh erythrocytes. At a specific flow rate, the different deformable erythrocytes in the chip move in different paths. Then, the influence of erythrocyte deformability on its movement trajectory was analyzed by two-dimensional finite element flow simulation. DLD sorting technology provides a new method for the sorting and enrichment of diseased erythrocytes.

Precisely controlling magnetically tagged cells in a complex environment is crucial to constructing a magneto-microfluidic platform. We propose a two-dimensional model for capturing magnetic beads from non-magnetic fluids under a micromagnetic matrix. A qualitative description of the relationship between the capture trajectory and the micromagnetic matrix with an alternating polarity configuration was obtained by computing the force curve of the magnetic particles. Three stages comprise the capture process: the first, where motion is a parabolic fall in weak fields; the second, where the motion becomes unpredictable due to the competition between gravity and magnetic force; and the third, where the micromagnetic matrix finally captures cells. Since it is not always obvious how many particles are adhered to the surface, attachment density is utilized to illustrate how the quantity of particles influences the capture path. The longitudinal magnetic load is calculated to measure the acquisition efficiency. The optimal adhesion density is 13%, and the maximum adhesion density is 18%. It has been demonstrated that a magnetic ring model with 100% adhesion density can impede the capture process. The results offer a theoretical foundation for enhancing the effectiveness of rare cell capture in practical applications.

Nanoscale liposomes have been extensively researched and employed clinically for the delivery of biologically active compounds, including chemotherapy drugs and vaccines, offering improved pharmacokinetic behaviour and therapeutic outcomes. Traditional laboratory-scale production methods often suffer from limited control over liposome properties (e.g., size and lamellarity) and rely on laborious multistep procedures, which may limit pre-clinical research developments and innovation in this area. The widespread adoption of alternative, more controllable microfluidic-based methods is often hindered by complexities and costs associated with device manufacturing and operation, as well as the short device lifetime and the relatively low liposome production rates in some cases. In this study, we demonstrated the production of liposomes comprising therapeutically relevant lipid formulations, using a cost-effective 3D-printed reactor-in-a-centrifuge (RIAC) device. By adjusting formulation- and production-related parameters, including the concentration of polyethylene glycol (PEG), temperature, centrifugation time and speed, and lipid concentration, the mean size of the produced liposomes could be tuned in the range of 140 to 200 nm. By combining selected experimental parameters, the method was capable of producing liposomes with a therapeutically relevant mean size of ~174 nm with narrow size distribution (polydispersity index, PDI ~0.1) at a production rate of >8 mg/min. The flow-through method proposed in this study has potential to become an effective and versatile laboratory-scale approach to simplify the synthesis of therapeutic liposomal formulations.

Erythrocyte enrichment is needed for blood disease diagnosis and research. DLD arrays with an I-shaped pillar (I-pillar) sort erythrocytes in a unique, accurate, and low-reagent method. However, the existing I-shaped pillar DLD arrays for erythrocyte sorting have the drawbacks of higher flow resistance and more challenging fabrication. A two-dimensional erythrocyte simulation model and the arbitrary Lagrangian–Euler equations at the cell–fluid boundary were built based on the fluid–solid coupling method to investigate the influencing factors of the erythrocyte flow path in an I-pillar DLD array and find its optimization method. Three different sizes of I-pillars were built and multiple sets of corresponding arrays were constructed, followed by finite element simulations to separately investigate the effects of these arrays on the induction of erythrocyte motion paths. This work demonstrates the motion paths of erythrocyte models in a series of I-pillar arrays with different design parameters, aiming to summarize the variation modes of erythrocyte motion paths, which in turn provides some reference for designing and optimizing the pillar size and array arrangement methods for I-pillar array DLD chips.

Abstract Circulating tumor cells (CTCs) largely contribute to cancer metastasis and show potential prognostic significance in cancer isolation and detection. Miniaturization has progressed significantly in the last decade which in turn enabled the development of several microfluidic systems. The microfluidic systems offer a controlled microenvironment for studies of fundamental cell biology, resulting in the rapid development of microfluidic isolation of CTCs. Due to the inherent ability of magnets to provide forces at a distance, the technology of CTCs isolation based on the magnetophoresis mechanism has become a routine methodology. This historical review aims to introduce two principles of magnetic isolation and recent techniques, facilitating research in this field and providing alternatives for researchers in their study of magnetic isolation. Researchers intend to promote effective CTC isolation and analysis as well as active development of next‐generation cancer treatment. The first part of this review summarizes the primary principles based on positive and negative magnetophoretic isolation and describes the metrics for isolation performance. The second part presents a detailed overview of the factors that affect the performance of CTC magnetic isolation, including the magnetic field sources, functionalized magnetic nanoparticles, magnetic fluids, and magnetically driven microfluidic systems.

Back pain: overactive protein causes disc breakdown Treatments targeting a protein that is overexpressed in damaged spinal cartilage could ease degenerative conditions associated with lower back pain. The intervertebral discs are complex cartilage tissues that absorb forces while allowing the motion of our spines. An immune-promoting enzyme called calcineurin is important in maintaining the supple, gel-like structure of the central part of each disc, the nucleus pulposus (NP). Fendong Zhao and Jian Chen at Zhejiang University School of Medicine Hangzhou, China and co-workers showed that RCAN1.4, a protein known to suppress calcineurin, is overexpressed in damaged human NPs. The team further revealed how a signaling pathway starting with RCAN1.4 suppresses key genes involved in forming the collagen fibers that hold the NP together. They therefore suggest that therapies targeting this protein could benefit patients suffering from disc degeneration diseases.

Abstract Objective To determine the efficacy of OLIF in the treatment of reoccurring discogenic low back pain (LBP) after discoblock Methods We included 108 patients with LBP that was suspected to be discogenic (such as high intensity zone, Schmorl’s nodes, Modic changes Type I, etc.), from August 2015 to August 2017. All patients underwent discography, and patients whose LBP was confirmed to be discogenic received discoblock. Patients who had reoccurring pain after discoblock underwent OLIF. Perioperative parameters and complications were recorded. The VAS and Oswestry Disability Index (ODI) were assessed at preoperation, and 1 week and 1, 3, 6, and 12 months after the surgery. The fusion rate was evaluated. Results Of 108 patients, 89 were confirmed to have discogenic LBP, and 32/89 patients with reoccurring LBP pain after discoblock underwent OLIF. Twenty-eight patients were followed up for ≥ 1 year. The OLIF operation lasted for 92 ± 34 min. Blood loss during the operation was 48 ± 15 ml. The mean incision length was 3.0 ± 0.6 cm. The average length of stay was 4.8 ± 1.9 days. The VAS and ODI scores decreased from 8.1 ± 1.7 preoperatively to 0.9 ± 0.4, and from 71.2 ± 11.3 to 9.3 ± 3.1, 12 months postoperatively, respectively. The total incidence of complications was 15.6%, including 2 cases of cage subsidence, 2 cases of ipsilateral hip flexor weakness, and 1 case of ipsilateral anterior thigh pain. All symptoms relieved or disappeared during follow-up. The fusion rate was 96.9%. Conclusions Reoccurring discogenic LBP after discoblock should be considered as a suitable group for treatment by OLIF.

The dermal fibroblast is a crucial executor involved in wound healing, and lipopolysaccharide is a key factor in initiating the migration and proliferation of the dermal fibroblasts, followed by wound healing. However, the underlying molecular mechanism is still unknown. In this study, we demonstrated that stathmin increased concomitantly with p38/MAPK pathway activation by lipopolysaccharide stimulation of the human dermal fibroblast (HDF), which induced microtubule (MT) depolymerization followed by increased HDF migration and proliferation. In contrast, the application of taxol, the small interfering RNA transfection of stathmin, or the application of the p38/MAPK inhibitor SB203580 suppressed MT depolymerization and HDF migration and proliferation. Additionally, the overexpression of a MKK6(Glu) mutant, which constitutively activated p38/MAPK, resulted in MT depolymerization and, subsequently, promoted HDF migration and proliferation. Our data reveal a crucial role of stathmin in HDF migration and proliferation. These findings will provide new targets and strategies for clinical interventions in wound healing.

Accurate prediction of air temperature is of great significance to outdoor activities and daily life. However, it is important and more challenging to predict air temperature in complex terrain areas because of prevailing mountain and valley winds and variable wind directions. The main innovation of this paper is to propose a regional temperature prediction method based on deep spatiotemporal networks, designing a spatiotemporal information processing module to align temperature data with regional grid points and further transforming temperature time series data into image sequences. Long Short-Term Memory network is constructed on the images to extract the depth features of the data to train the model. The experiments demonstrate that the deep learning prediction model containing the spatiotemporal information processing module and the deep learning prediction module is fully feasible in short-term regional temperature prediction. The comparison experiments show that the model proposed in this paper has better prediction results for classical models, such as convolutional neural networks and LSTM networks. The experimental conclusion shows that the method proposed in this paper can predict the distribution and change trend of temperature in the next 3 h and the next 6 h on a regional scale. The experimental result RMSE reached 0.63, showing high stability and accuracy. The model provides a new method for local regional temperature prediction, which can support the planning of production and life in advance and tend to save energy and reduce consumption.

A three-dimensional numerical investigation of turbulent heat transfer and fluid flow characteristics of the new heat exchanger and self-support of a rectangular converging-diverging (SS-RCD) tube bundle heat exchanger with different inserts was performed. The values of the Reynolds number varied from 27,900 to 41,900. The baseline case (without an insert) was compared with two enhanced configurations: one circular hole in the baffle plate (one-circle case) and a rectangular hole in the baffle plate (one-rectangle case). Compared with the baseline case, the airside Nusselt number (Nu) of the enhanced cases improved by 39.6~48.0% and 36.2~40.2% and had an associated friction factor (f) penalty increase of 53.9–66.7% and 60.7–77.8%, respectively. The baseline case was compared with three enhanced configurations: one-circle case, two-circle case, and three-circle case baffle plate. Compared with the baseline case, Nu of the enhanced cases improved by 39.6–48.0%, 36.2–45.4%, and 35.0–44.2%, with f penalty increases of 53.9–66.7%, 44.9–60.0%, and 43.8–60.0%, respectively. The overall performance was conducted by heat transfer enhancement factor (η). It was found that the one circle case obtained the best overall performance. The numerical results were analyzed from the viewpoint of the field synergy principle. It was found that the reduction in the average intersection angle between the velocity vector and the temperature gradient (θ) was one of the essential factors influencing heat transfer performance.

Abstract Lack of tumor‐infiltration lymphocytes (TILs) and resistances by overexpressed immunosuppressive cells (principally, myeloid‐derived suppressor cells (MDSCs)) in tumor milieu are two major challenges hindering the effectiveness of immunotherapy for “immune‐cold” tumors. In addition, the natural physical barrier existing in solid cancer also limits deeper delivery of drugs. Here, a tumor‐targeting and light‐responsive‐penetrable nanoplatform (Apt/PDGs^s@pMOF) is developed to elicit intratumoral infiltration of cytotoxic T cells (CTLs) and reeducate immunosuppressive microenvironment simultaneously. In particular, porphyrinic metal–organic framework (pMOF)–based photodynamic therapy (PDT) induces tumor immunogenic cell death (ICD) to promote CTLs intratumoral infiltration and hot “immune‐cold” tumor. Upon being triggered by PDT, the nearly 10 nm adsorbed drug‐loaded dendrimer de‐shields from the nanoplatform and spreads into the deeper tumor, eliminating MDSCs and reversing immunosuppression, eventually reinforcing immune response. Meanwhile, the designed nanoplatform also has a systemic MDSC inhibition effect and moderate improvement of overall antitumor immune responses, resulting in effective suppression of distal tumors within less significant immune‐related adverse effects (irAEs) induced.

Abstract Tumor‐associated macrophages (TAMs) constitute over 50% of the number of cells within the tumor, playing a major role in tumor progression and invasion. Remodeling the tumor immune microenvironment by modulating TAM polarization has been emerging as a new and promising therapeutic strategy. However, the high interstitial fluid pressure and dense extracellular matrix lead to insufficient penetration of nanosized therapies. To overcome this dilemma, an acid‐triggered size‐changeable nanoparticle (aptamer/acid sensitive linker crosslinked DGL/zoledronic acid, i.e., Apt@(DGL‐ZA)n NPs) with effective tumor distribution, extravasation, and penetration is designed. Dendrigraft poly‐L‐lysines (DGLs) which can induce tumor autophagy as mimics of natural abnormal proteins are crosslinked via a mild‐acid‐responsive linker (1,6‐bis(4‐formylbenzoyloxy) hexane). Long circulation property and tumor penetration are achieved simultaneously by catching DGLs in neutral pH while releasing them in the tumor's pH, like dandelion seeds in midair. The macrophage conditioning agent zoledronic acid (ZA) is loaded on DGLs by the charge attraction. A Tenascin‐C targeting aptamer (GBI‐10) is modified onto (DGL‐ZA)n NPs for a tumor‐homing effect. Apt@(DGL‐ZA)n NPs show both enhanced penetration in in vitro 3D triple negative breast cancer spheroids and in vivo tumor tissues. Effective macrophage regulation, enhanced tumor autophagy, and excellent in vivo antitumor efficacy are achieved, suggesting this tactic as a significant antitumor strategy.

The paper presents a concept of thermal-to-electrical energy conversion by using the oscillatory motion of magnetic fluid slugs which has potential to be applied in the field of sensors. A pulsating heat pipe (PHP) is introduced to produce vapor-magnetic fluid plug–slug flow in a snake-shaped capillary tube. As the magnetic fluid is magnetized by the permanent magnet, the slugs of magnetic fluid passing through the copper coils make the magnetic flux vary and produce the electromotive force. The peak values of induced voltage observed in our tests are from 0.1 mV to 4.4 mV. The effects of the slug velocity, heat input and magnetic particle volume concentration on the electromotive force are discussed. Furthermore, a theoretical model considering the fluid velocity of the working fluid, the inner radius of the PHP and the contact angle between the working fluid and the pipe wall is established. At the same time, the theoretical and experimental results are compared, and the influences of tube inner radius, working fluid velocity and contact angle on the induced electromotive force are analyzed.

Deterministic lateral displacement (DLD) technology has great potential for the separation, enrichment, and sorting of red blood cells (RBCs). This paper presents a numerical simulation of the motion of RBCs using DLD devices with different pillar shapes and gap configurations. We studied the effect of the pillar shape, row shift, and pillar diameter on the performance of RBC separation. The numerical results show that the RBCs enter “displacement mode” under conditions of low row-shift (∆λ < 1.4 µm) and “zigzag mode” with large row shift (∆λ > 1.5 µm). RBCs can pass the pillar array when the size of the pillar (d > 6 µm) is larger than the cell size. We show that these conclusions can be helpful for the design of a reliable DLD microfluidic device for the separation of RBCs.

This paper presents a numerical simulation on the heat transfer of liquid sodium in a solar receiver tube, as the liquid sodium is a promising heat-transfer candidate for the next generation solar-power-tower (SPT) system. A comparison between three mediums—solar salt, Hitec and liquid sodium—is presented under uniform and nonuniform heat-flux configurations. We studied the effects of mass flow rate (Qm), inlet temperature (Tin), and maximum heat flux (qomax), on the average heat-transfer coefficient (h) and the friction coefficient (f) of the three mediums. The results show that the h of liquid sodium is about 2.5 to 5 times than other two molten salts when Tin is varying from 550 to 800 K, Qm is 1.0 kg/s, and qomax is 0.1 MW/m2. For maximum heat fluxes from 0.1 to 0.3 MW/m2, the h of liquid sodium is always an order of magnitude larger than that of Hitec and Solar-Salt (S-S), while maintaining a small friction coefficient.

The ability to focus biological particles into a designated position of a microchannel is vital for various biological applications. This paper reports particle focusing under vertical and inclined magnetic fields. We analyzed the effect of the angle of rotation (θ) of the permanent magnets and the critical Reynolds number (Rec) on the particle focusing in depth. We found that a rotation angle of 10° is preferred; a particle loop has formed when Re < Rec and Rec of the inclined magnetic field is larger than that of the vertical magnetic field. We also conducted experiments with polystyrene particles (10.4 μm in diameter) to prove the calculations. Experimental results show that the focusing effectiveness improved with increasing applied magnetic field strength or decreasing inlet flow rate.

Miscanthus and Saccharum are considered excellent candidates for bioenergy feedstock production. A field experiment was conducted in Zhejiang province of China to characterize the phenotypic differences in three species, two of Miscanthus (M. sinensis and M. floridulus) and one of Saccharum (S. arundinaceum), each with two accessions collected from China. Agronomical traits, including plant height, culm number, tuft diameter and culm diameter, were monitored monthly for the first 3 years of growth. For each year of trail, flowering time was observed and biomass yield was harvested. M. floridulus produced a superior biomass yield with increasing plant age associated with higher yields (4.18, 24.16 and 29.01 t dry matter/ha in November of years one to three, respectively). Higher culm diameter, plant height and tuft diameter values were observed for M. floridulus when compared to the other species. Biomass yield was positively correlated to tuft diameter, culm diameter, culm number and negatively to flowering time, but it showed no correlation with plant height. Tuft diameter and culm diameter could be suitable indicators in the selection of accessions for crop yield at the yield-building phase. Studies of the primary colonizers of Miscanthus and Saccharum in their original location may be of interest from the perspective of bioenergy germplasm resource collection.