12 research outputs found
Simulation and Experiment on Droplet Volume for the Needle-Type Piezoelectric Jetting Dispenser
The needle-type piezoelectric jetting dispenser is widely applied in the microelectronics packaging field, and it is important to control the droplet size to ensure that the droplet jetting process is successful. In this study, we analyzed the influences of system parameters, such as air pressure, nozzle size, needle strokes, and liquid properties, on droplet size and morphology by considering the droplet formation and separation process through a numerical simulation. An experimental platform was also designed to verify the reliability of the simulations and further analyze strategies for controlling the droplet size. We found that the droplet volume can be increased with an increase in air pressure, needle strokes, and nozzle size until the flow-stream or satellite droplets appear. On the other hand, very small values of these parameters will lead to adhesion or micro-dots. A large nozzle and needle displacement should be chosen for the high-viscosity liquid in order to produce normal droplets. The results also show the recommended ranges of parameter values and suitable droplet volumes for liquids with different viscosities, and these findings can be used to guide the droplet volume control process for needle-type jetting dispensers
Phosphite Application Alleviates Pythophthora infestans by Modulation of Photosynthetic and Physio-Biochemical Metabolites in Potato Leaves
Potato late blight (Phytophtora infestans) is among the most severely damaging diseases of potato (Solanum tuberusom L.) worldwide, causing serious damages in potato leaves and tubers. In the present study, the effects of potassium phosphite (KPhi) applications on photosynthetic parameters, enzymatic and non-enzymatic antioxidant properties, hydrogen peroxide (H2O2) and malondialdehyde (MDA), total protein and total carbohydrate of potato leaves challenged with P. infestans pathogen were investigated. Potato leaves were sprayed five times with KPhi (0.5%) during the growing season prior to inoculation with P. infestans. The potato leaves were artificially infected by the LC06-44 pathogen isolate. The leaves were sampled at 0, 24, 48, 72 and 96 h after the infection for evaluations. P. infestans infection reduced chlorophyll (Chl) pigments contents, chlorophyll fluorescence, carotenoid (Car) and anthocyanin contents and increased the accumulation of H2O2 and MDA. Meanwhile, our result showed that KPhi treatment alleviated adverse effect of late blight in potato leaves. KPhi application also increased plant tolerance to the pathogen with improved photosynthetic parameters Chl a, b, total Chl, Car, and anthocyanin compare to controls. Moreover, the increased oxidative enzymes activity of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APx), and non-enzymatic substances such as phenolics, flavonoids and proline were found in KPhi treated plants, compared to untreated plants after inoculation. In addition, KPhi application followed by P. infestans infection also decreased the content of H2O2 and MDA, but increased the total protein and total carbohydrate contents in potato leaves. The consequence of current research indicated that KPhi played a vital role in pathogen tolerance, protecting the functions of photosynthetic apparatus by improved oxidative levels and physio-biochemical compounds in potato leaves
Magnetic Damping Constant of CoFeB/Pt Thin Films With Varying the Thicknesses of Pt and Insertion Layer of Al
Global longitudinal strain at 3âmonths after therapy can predict late cardiotoxicity in breast cancer
Abstract Background Cancer therapyârelated cardiovascular toxicity (CTRâCVT) is a major contributor to poor prognosis in breast cancer (BC) patients undergoing chemotherapy. Left ventricular global longitudinal strain (LV GLS) has predictive value for CTRâCVT, while few researchers take into account lateâonset CTRâCVT. This study sought to provide a guide for the prediction of lateâonset CTRâCVT in primary BC over the 2âyears followâup via strain and contrastâenhanced echocardiography. Methods Anthracycline and anthracyclineâ+âtargeted medication groups were created from 111 patients with stage IâIII primary BC who were prospectively included. The left ventricular diastolic function, LV global longâaxis strain (GLS); left ventricular ejection fraction by contrastâenhanced echocardiography (câLVEF), and electrocardiograms were collected at baseline, 3, 6, 12, and 24âmonths after the start of cancer treatment. The highâsensitivity troponinâT and NTâpro BNP at baseline and 3âmonths after chemotherapy were measured. Results (1) LV GLS decreased in BC patients over time. (2) After 12âmonths' followâup, the LV GLS in the anthracycline+ targeted group was lower than in the anthracycline group. After 24âmonths' followâup, the GLS and câLVEF in the anthracyclineâ+âtargeted group declined while the E/eâ increased. (3) Decreased LVEF (56%) and arrhythmia (38%) are the common causes of CTRâCVT. Lower LVEF was a major factor in lateâonset CTRâCVT. (4) Combination of LV GLS and câLVEF at 3âmonths were used as predictors for CTRâCVT and exhibited a higher AUC than either one alone (AUCâ=â0.929, 95% CI: 0.863â0.970). LV GLS at 3âmonths can predict the lateâonset CTRâCVT (AUCâ=â0.745, pâ<â0.001), and the cutâoff is 20.32%. Conclusions As time went on, the systolic and diastolic dysfunction of BC patients get worsened. The combination of LV GLS and câLVEF is better in the prediction of CTRâCVT. Only the LV GLS at 3âmonths can predict the lateâonset CTRâCVT
Global longitudinal strain assessment in contrast-enhanced echocardiography in breast cancer patients: a feasibility study
Abstract Background Left ventricular global longitudinal strain (GLS) obtained from two-dimensional speckle-tracking echocardiography (2D-STE) can reflect cancer therapy-related cardiac dysfunction in breast cancer (BC) patients, however, the accuracy and reproducibility of 2D-STE are restricted due to poor image quality. Methods Between January 2019 and October 2021, 160 consecutive BC patients agedââ„â18 years were recruited. The 160 BC patients (mean age: 48.41â±â9.93 years, 100% women) underwent both 2D-STE and Contrast-enhanced echocardiography (CEcho), 125 of whom were included in the measurement of GLS. The intraclass correlation coefficient (ICC) was used to determine the intra- and inter-observer reproducibility of 2D-STE and CEcho-STE. Correlation (r) was calculated using Pearson correlation. Statistical significance was set at Pâ<â0.05. Results Among 160 BC patients, more segments were recognized by CEcho-STE than by 2D-STE (2,771, 99.53% vs. 2,440, 84.72%). The left ventricular ejection fraction (LVEF) obtained by 2D was lower than CEcho (61.75â±â6.59% vs. 64.14â±â5.97%, Pâ<â0.0001). The GLS obtained by 2D-STE was lower than CEcho-STE (-21.74â±â2.77% vs. -26.79â±â4.30%, Pâ=â0.001). The ICC of the intraobserver and interobserver agreements in the CEcho-STE group was lower than that in the 2D-STE group. GLS measurements were in good agreement between the 2D-STE and CEcho-STE groups (râ=â0.773). Conclusions CEcho can overcome some imaging limitations and recognize more segments than 2D, which may provide an LVEF and GLS closer to the true value. Based on AutoStrain, CEcho-STE may serve as a complementary method for those with poor image quality. Graphical Abstrac
The Genetic and Epigenetic Mechanisms Involved in Irreversible Pulp Neural Inflammation
Aim. To identify the critical genetic and epigenetic biomarkers by constructing the long noncoding RNA- (lncRNA-) related competing endogenous RNA (ceRNA) network involved in irreversible pulp neural inflammation (pulpitis). Materials and Methods. The public datasets regarding irreversible pulpitis were downloaded from the gene expression omnibus (GEO) database. The differential expression analysis was performed to identify the differentially expressed genes (DEGs) and DElncRNAs. Functional enrichment analysis was performed to explore the biological processes and signaling pathways enriched by DEGs. By performing a weighted gene coexpression network analysis (WGCNA), the significant gene modules in each dataset were identified. Most importantly, DElncRNA-DEmRNA regulatory network and DElncRNA-associated ceRNA network were constructed. A transcription factor- (TF-) DEmRNA network was built to identify the critical TFs involved in pulpitis. Result. Two datasets (GSE92681 and GSE77459) were selected for analysis. DEGs involved in pulpitis were significantly enriched in seven signaling pathways (i.e., NOD-like receptor (NLR), Toll-like receptor (TLR), NF-kappa B, tumor necrosis factor (TNF), cell adhesion molecules (CAMs), chemokine, and cytokine-cytokine receptor interaction pathways). The ceRNA regulatory relationships were established consisting of three genes (i.e., LCP1, EZH2, and NR4A1), five miRNAs (i.e., miR-340-5p, miR-4731-5p, miR-27a-3p, miR-34a-5p, and miR-766-5p), and three lncRNAs (i.e., XIST, MIR155HG, and LINC00630). Six transcription factors (i.e., GATA2, ETS1, FOXP3, STAT1, FOS, and JUN) were identified to play pivotal roles in pulpitis. Conclusion. This paper demonstrates the genetic and epigenetic mechanisms of irreversible pulpitis by revealing the ceRNA network. The biomarkers identified could provide research direction for the application of genetically modified stem cells in endodontic regeneration
Current-Induced Domain Wall Motion and Tilting in Perpendicularly Magnetized Racetracks
Abstract The influence of C insertion on DzyaloshinskiiâMoriya interaction (DMI) as well as current-induced domain wall (DW) motion (CIDWM) and tilting in Pt/Co/Ta racetracks is investigated via a magneto-optical Kerr microscope. The similar DMI strength for Pt/Co/Ta and Pt/Co/C/Ta samples reveals that DMI mainly comes from the Pt/Co interface. Fast DW velocity around tens of m/s with current density around several MA/cm2 is observed in Pt/Co/Ta. However, it needs double times larger current density to reach the same magnitude in Pt/Co/C/Ta, indicating DW velocity is related to the spin-orbit torque efficiency and pinning potential barrier. Moreover, in CIDWM, DW velocity is around 103 times larger than that in field-induced DW motion (FIDWM) with current-generated effective field keeping the same magnitude as applied magnetic field, revealing that the current-generated Joule heating has an influence on DW motion. Interestingly, current-induced DW tilting phenomenon is observed, while this phenomenon is absent in FIDWM, demonstrating that the current-generated Oersted field may also play an essential role in DW tilting. These findings could provide some designing prospects to drive DW motion in SOT-based racetrack memories
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Mitochondrial genome undergoes de novo DNA methylation that protects mtDNA against oxidative damage during the peri-implantation window
Mitochondrial remodeling during the peri-implantation stage is the hallmark event essential for normal embryogenesis. Among the changes, enhanced oxidative phosphorylation is critical for supporting high energy demands of postimplantation embryos, but increases mitochondrial oxidative stress, which in turn threatens mitochondrial DNA (mtDNA) stability. However, how mitochondria protect their own histone-lacking mtDNA, during this stage remains unclear. Concurrently, the mitochondrial genome gain DNA methylation by this stage. Its spatiotemporal coincidence with enhanced mitochondrial stress led us to ask if mtDNA methylation has a role in maintaining mitochondrial genome stability. Herein, we report that mitochondrial genome undergoes de novo mtDNA methylation that can protect mtDNA against enhanced oxidative damage during the peri-implantation window. Mitochondrial genome gains extensive mtDNA methylation during transition from blastocysts to postimplantation embryos, thus establishing relatively hypermethylated mtDNA from hypomethylated state in blastocysts. Mechanistic study revealed that DNA methyltransferase 3A (DNMT3A) and DNMT3B enter mitochondria during this process and bind to mtDNA, via their unique mitochondrial targeting sequences. Importantly, loss- and gain-of-function analyses indicated that DNMT3A and DNMT3B are responsible for catalyzing de novo mtDNA methylation, in a synergistic manner. Finally, we proved, in vivo and in vitro, that increased mtDNA methylation functions to protect mitochondrial genome against mtDNA damage induced by increased mitochondrial oxidative stress. Together, we reveal mtDNA methylation dynamics and its underlying mechanism during the critical developmental window. We also provide the functional link between mitochondrial epigenetic remodeling and metabolic changes, which reveals a role for nuclear-mitochondrial crosstalk in establishing mitoepigenetics and maintaining mitochondrial homeostasis