Fully inkjet-printed Ag2Se flexible thermoelectric devices for sustainable power generation.

Flexible thermoelectric devices show great promise as sustainable power units for the exponentially increasing self-powered wearable electronics and ultra-widely distributed wireless sensor networks. While exciting proof-of-concept demonstrations have been reported, their large-scale implementation is impeded by unsatisfactory device performance and costly device fabrication techniques. Here, we develop Ag2Se-based thermoelectric films and flexible devices via inkjet printing. Large-area patterned arrays with microscale resolution are obtained in a dimensionally controlled manner by manipulating ink formulations and tuning printing parameters. Printed Ag2Se-based films exhibit (00 l)-textured feature, and an exceptional power factor (1097 µWm-1K-2 at 377 K) is obtained by engineering the film composition and microstructure. Benefiting from high-resolution device integration, fully inkjet-printed Ag2Se-based flexible devices achieve a record-high normalized power (2 µWK-2cm-2) and superior flexibility. Diverse application scenarios are offered by inkjet-printed devices, such as continuous power generation by harvesting thermal energy from the environment or human bodies. Our strategy demonstrates the potential to revolutionize the design and manufacture of multi-scale and complex flexible thermoelectric devices while reducing costs, enabling them to be integrated into emerging electronic systems as sustainable power sources.

Transition from Schottky to Ohmic contacts in 2D Ge/GaAs heterostructures with high tunneling probability.

The metal-semiconductor (M-S) contact is usually an Ohmic contact or a Schottky contact, which greatly affects the electronic properties of devices, and it remains a huge challenge to realize a low-resistance Ohmic contact in a metal-semiconductor junction (MSJ). Herein, we systematically studied the band structures, electrostatic potential, charge transfer, Schottky barrier height of carriers, effective carrier masses, and tunneling probability of carriers of a germanene (Ge)/GaAs MSJ. The transition from the Schottky to the Ohmic contact can be caused by applying certain biaxial strains or electric fields, which weakens the Fermi level pinning (FLP) effect and reduces contact resistance. Meanwhile, the electron injection efficiency of Ge/(GaAs)As MSJ (PTB > 27%) is far superior to that of other two-dimensional (2D) vdW MSJs. This work indicates that Ge/GaAs heterostructures are the most compatible for applying high-effective 2D electronic nanodevices under controllable conditions.

Process Investigation on Robust Electrospinning of Non-Aligned and Aligned Polyvinylidene Fluoride Nanofiber Mats for Flexible Piezoelectric Sensors.

Polyvinylidene fluoride (PVDF) nanofiber mats have played a significant role in wearable electronic devices that have been in great demand in recent decades. Although manifold PVDFbased freely stacked or well-aligned nanofiber mats created via the electrospinning process have been demonstrated to achieve multisensory capabilities with high sensitivity and long detection range, rarely have any of them proved their ability with a stable process and accurate processing parameters. In this work, we successfully developed freely stacked and well-aligned PVDF nanofiber mats with diameters ranging from micrometers to nanometers, providing stable performance for wearable electronic devices. Through in-depth investigations into material preparation, electrospinning, and fiber collection processes, we revealed the relationship between the nanofiber morphology, ß-phase fraction, and piezoelectric output with various process parameters. Characterized by analytical methods, we have established a mature, reliable nanofiber mat fabrication system capable of mass-producing PVDF nanofibers with the required diameter and consistent properties. At 18 kV voltage and 60% RH humidity, the uniformity of the fiber diameter and ß-phase content was maintained in a favorable range. When the drum speed increased to 2000 r/s, the fiber orientation and ß-phase content increased. We assembled aligned PVDF nanofiber mats with conductive fabric in a flexible piezoelectric sensor that successfully monitored different body movements and produced an output voltage of 0.1 V. This study provides the necessary process parameters for the large-scale production of high-quality PVDF nanofiber mats and provides clear guidance for beginners in the field of nanofiber mat manufacturing.

Optical biosensor based on weak measurement for ultra-sensitive detection of calreticulin in human serum.

A novel real-time optical phase sensing method based on the Mach-Zehnder interference principle has been proposed for the detection of calreticulin (CRT) levels in human serum samples. In this approach, anti-CRT antibodies are utilized to capture CRT molecules in serum, leading to a phase shift in both the measuring and reference arms of the system. By employing the concept of weak amplification within the framework of weak measurements, it becomes feasible to continuously monitor the response of CRT in real-time, allowing for the precise determination of serum CRT content at the picomolar level. Our achievement may pave the way in establishing CRT as a diagnostic biomarker for a wide range of medical applications, including rheumatoid arthritis.

Oxidation Analysis of l-Cysteine with a Chiral Sensor Based on Quantum Weak Measurement.

l-Cysteine, distinguished by its possession of reactive sulfhydryl groups within its molecular structure, plays a significant role in both biological systems and the pharmaceutical industry. It stands not only as a natural component integral to the constitution of glutathione but also as the principal precursor for the synthesis of l-cystine through an oxidation reaction. This study endeavors to introduce a novel approach to l-cysteine analysis, capitalizing on its optical activity, whereby an optical rotation detection system grounded in the principles of quantum weak measurement is proffered. The optical rotation angle corresponding to the concentration of chiral solutions can be accurately ascertained through spectral analysis. In practical implementation, a chiral sensing system, boasting a sensitivity of 372 nm/rad, was meticulously constructed, leveraging the concept of weak value amplification. Then, the real-time monitoring of chemical reactions involving l-cysteine and dimethyl sulfoxide was performed. Under the specific experimental conditions outlined in this investigation, it was observed that the oxidation process culminated within approximately 12 h. The application of weak measurement-based chiral sensors holds immense potential, providing robust technical support for real-time monitoring in fields such as chiral analysis and the synthesis of chiral pharmaceutical compounds.

EGFR/MAPK signaling pathway acts as a potential therapeutic target for sulforaphane-rescued heart tube malformation induced by various concentrations of PhIP exposure.

BACKGROUND: 2-Amino-1-methyl-6-phenylimidazo [4,5-b] pyrimidine (PhIP) is a known carcinogen generated mainly from cooking meat and environmental pollutants. It is worth exploring the potential of natural small-molecule drugs to protect against adverse effects on embryonic development. PURPOSE: In this study, we investigated the potential toxicological effects of PhIP on embryonic heart tube formation and the effect of Sulforaphane (SFN) administration on the anti-toxicological effects of PhIP on embryonic cardiogenesis. STUDY DESIGN AND METHODS: First, the chicken embryo model was used to investigate the different phenotypes of embryonic heart tubes induced by various concentrations of PhIP exposure. We also proved that SFN rescues PhIP-induced embryonic heart tube malformation. Second, immunofluorescence, western blot, Polymerase Chain Reaction (PCR) and flow cytometry experiments were employed to explore the mechanisms by which SFN protects cardiac cells from oxidative damage in the presence of PhIP. We used RNA-seq analysis, molecular docking, in situ hybridization, cellular thermal shift assay and solution nuclear magnetic resonance spectroscopy to explore whether SFN protects cardiogenesis through the EGFR/MAPK signaling pathway. RESULTS: The study showed that PhIP might dose-dependently interfere with the C-looping heart tube (mild) or the fusion of a pair of bilateral endocardial tubes (severe) in chick embryos, while SFN administration prevented cardiac cells from oxidative damage in the presence of high-level PhIP. Furthermore, we found that excessive reactive oxygen species (ROS) production and subsequent apoptosis were not the principal mechanisms by which low-level PhIP induced malformation of heart tubes. This is due to PhIP-disturbed Mitogen-activated protein kinase (MAPK) signaling pathway could be corrected by SFN administration. CONCLUSIONS: This study provided novel insight that PhIP exposure could increase the risk of abnormalities in early cardiogenesis and that SFN could partially rescue various concentrations of PhIP-induced abnormal heart tube formation by targeting EGFR and mediating EGFR/MAPK signaling pathways.

Disrupted Gray Matter Networks Associated with Cognitive Dysfunction in Cerebral Small Vessel Disease.

This study aims to investigate the disrupted topological organization of gray matter (GM) structural networks in cerebral small vessel disease (CSVD) patients with cerebral microbleeds (CMBs). Subject-wise structural networks were constructed from GM volumetric features of 49 CSVD patients with CMBs (CSVD-c), 121 CSVD patients without CMBs (CSVD-n), and 74 healthy controls. The study used graph theory to analyze the global and regional properties of the network and their correlation with cognitive performance. We found that both the control and CSVD groups exhibited efficient small-world organization in GM networks. However, compared to controls, CSVD-c and CSVD-n patients exhibited increased global and local efficiency (Eglob/Eloc) and decreased shortest path lengths (Lp), indicating increased global integration and local specialization in structural networks. Although there was no significant global topology change, partially reorganized hub distributions were found between CSVD-c and CSVD-n patients. Importantly, regional topology in nonhub regions was significantly altered between CSVD-c and CSVD-n patients, including the bilateral anterior cingulate gyrus, left superior parietal gyrus, dorsolateral superior frontal gyrus, and right MTG, which are involved in the default mode network (DMN) and sensorimotor functional modules. Intriguingly, the global metrics (Eglob, Eloc, and Lp) were significantly correlated with MoCA, AVLT, and SCWT scores in the control group but not in the CSVD-c and CSVD-n groups. In contrast, the global metrics were significantly correlated with the SDMT score in the CSVD-s and CSVD-n groups but not in the control group. Patients with CSVD show a disrupted balance between local specialization and global integration in their GM structural networks. The altered regional topology between CSVD-c and CSVD-n patients may be due to different etiological contributions, which may offer a novel understanding of the neurobiological processes involved in CSVD with CMBs.

Exceptional n-type thermoelectric ionogels enabled by metal coordination and ion-selective association.

Ionic liquid-based ionogels emerge as promising candidates for efficient ionic thermoelectric conversion due to their quasi-solid state, giant thermopower, high flexibility, and good stability. P-type ionogels have shown impressive performance; however, the development of n-type ionogels lags behind. Here, an n-type ionogel consisting of polyethylene oxide (PEO), lithium salt, and ionic liquid is developed. Strong coordination of lithium ion with ether oxygen and the anion-rich clusters generated by ion-preferential association promote rapid transport of the anions and boost Eastman entropy change, resulting in a huge negative ionic Seebeck coefficient (-15 millivolts per kelvin) and a high electrical conductivity (1.86 millisiemens per centimeter) at 50% relative humidity. Moreover, dynamic and reversible interactions among the ternary mixtures endow the ionogel with fast autonomous self-healing capability and green recyclability. All PEO-based ionic thermoelectric modules are fabricated, which exhibits outstanding thermal responses (-80 millivolts per kelvin for three p-n pairs), demonstrating great potential for low-grade energy harvesting and ultrasensitive thermal sensing.

Cadmium facilitates the formation of large lipid droplets via PLCß2-DAG-DGKε-PA signal pathway in Leydig cells.

Cadmium (Cd) exposure damages the reproductive system. Lipid droplets (LDs) play an important role in steroid-producing cells to provide raw material for steroid hormone. We have found that the LDs of Leydig cells exposed to Cd are bigger than those of normal cells, but the effects on steroidogenesis and its underlying mechanism remains unclear. Using Isobaric tag for relative and absolute quantitation (iTARQ) proteomics, phosphodiesterase beta-2 (PLCß2) was identified as the most significantly up-regulated protein in immature Leydig cells (ILCs) and adult Leydig cells (ALCs) derived from male rats exposed to maternal Cd. Consistent with high expression of PLCß2, the size of LDs was increased in Leydig cells exposed to Cd, accompanied by reduction in cholesterol and progesterone (P4) levels. However, the high PLCß2 did not result in high diacylglycerol (DAG) level, because Cd exposure up-regulated diacylglycerol kinases ε (DGKε) to promote the conversion from DAG to phosphatidic acid (PA). Exogenous PA, which was consistent with the intracellular PA concentration induced by Cd, facilitated the formation of large LDs in R2C cells, followed by reduced P4 level in the culture medium. When PLCß2 expression was knocked down, the increased DGKε caused by Cd was reversed, and then the PA level was decreased to normal. As results, large LDs returned to normal size, and the level of total cholesterol was improved to restore steroidogenesis. The accumulation of PA regulated by PLCß2-DAG-DGKε signal pathway is responsible for the formation of large LDs and insufficient steroid hormone synthesis in Leydig cells exposed to Cd. These data highlight that LD is an important target organelle for Cd-induced steroid hormone deficiency in males.

Broadband La2LiSbO6: Cr3+ Phosphors with Double Luminescent Centers for NIR pc-LEDs.

The La2LiSbO6: xCr3+ phosphors were synthesized by means of a high-temperature solid-phase method. Based on the differences in ionic radius, valence state, and formation energy, the substitution sites of Cr3+ ions are discussed in detail. The optimized doping concentration of Cr3+ is determined to be 0.01. Under 517 nm excitation, the La2LiSbO6: 0.01Cr3+ phosphor presents a wide emission band (from 700 to 1350 nm) with a peak centered at 952 nm. Additionally, its corresponding full width at half-maximum is 155 nm, and the internal quantum efficiency reaches 62.4%. Meanwhile, the emission intensity of the La2LiSbO6: 0.01Cr3+ phosphor at 373 K is about 63.7% of that at room temperature, exhibiting good thermal stability. Aiming to fabricate a near-infrared phosphor-converted light-emitting diode device, the La2LiSbO6: 0.01Cr3+ phosphor is mixed with epoxy adhesive and cured on a green light-emitting diode chip. Under the irradiation of the fabricated light-emitting diode device, fruits and writing in the dark environment can be captured by a near-infrared camera. Hence, the La2LiSbO6: 0.01Cr3+ phosphor is promising for night vision.

Suppressing grating lobes of large-aperture optical phased array with circular array design.

An optical phased array (OPA), especially a two-dimensional (2D) OPA, suffers from the trade-off among steering range, beam width, and the number of antennas. Aperiodic 2D array designs currently aimed to reduce the number of antennas and reduce grating lobes within a wide range fall short when an aperture approaches millimeter size. A circular OPA design is proposed to address this issue. The circular design substantially reduces the number of antennas while achieving the same wide steering range and narrow beam width of optimized aperiodic 2D OPA designs. Its efficient suppression of grating lobes, the key to a wide steering range with minimal number of antennas and large antenna spacing, is theoretically studied and validated by simulation. The novel, to the best of our knowledge, design allows less than 100 antennas, orders of magnitude reduction, for millimeter size aperture OPA designs. It paves the way for commercialization by significantly reducing control complexity and power consumption.

A multi-factor adjustable PtSe2/GaN van der Waals heterostructure with enhanced photocatalytic performance.

Two-dimensional van der Waals heterostructures with multiple tunable approaches in electronic and optical properties are highly superior for photocatalysis and novel devices. By applying first-principles calculations, we systematically studied the electronic structure, optical absorption, carrier mobility and solar-to-hydrogen efficiency of PtSe2/GaN heterostructures, which are affected by different thicknesses, varying directions of polarization of the GaN nanosheets and applied mechanical strain of the whole system. The results indicate that these heterostructures exhibit thermodynamic stability at room-temperature (300 K), and most configurations have type-II band alignment, among which the heterostructure consisting of GaN trilayers and PtSe2 shows high visible-light absorption (1.71 × 105 cm-1) and ultra-wide range of pH values (pH = 0-14) for the photocatalytic water splitting reaction and exceedingly high overpotential for the hydrogen evolution reaction (3.375 eV). Simultaneously, being two of the most significant parameters of photocatalysis and devices, the carrier mobility and solar-to-hydrogen efficiency have also been calculated, respectively, reaching up to 1601 cm2 V-1 s-1 and 17.2%. Moreover, the photoelectrical properties can be highly tuned through further biaxial strain engineering; especially, the visible-light absorption can be enhanced to 2.85 × 105 cm-1 by applying 6% compression strain. Thus, the PtSe2/GaN heterostructure we proposed shows a broad prospect for photocatalytic water splitting.

The reduced SCFA-producing gut microbes are involved in the inflammatory activation in Kawasaki disease.

Kawasaki disease (KD), an acute febrile systemic vasculitis in children, has become the leading cause of acquired heart disease in developed countries. Recently, the altered gut microbiota was found in KD patients during the acute phase. However, little is known about its characteristics and role in the pathogenesis of KD. In our study, an altered gut microbiota composition featured by the reduction in SCFAs-producing bacteria was demonstrated in the KD mouse model. Next, probiotic Clostridium butyricum (C. butyricum) and antibiotic cocktails were respectively employed to modulate gut microbiota. The use of C. butyricum significantly increased the abundance of SCFAs-producing bacteria and attenuated the coronary lesions with reduced inflammatory markers IL-1ß and IL-6, but antibiotics depleting gut bacteria oppositely deteriorated the inflammation response. The gut leakage induced by dysbiosis to deteriorate the host's inflammation was confirmed by the decreased intestinal barrier proteins Claudin-1, Jam-1, Occludin, and ZO-1, and increased plasma D-lactate level in KD mice. Mechanistically, SCFAs, the major beneficial metabolites of gut microbes to maintain the intestinal barrier integrity and inhibit inflammation, was also found decreased, especially butyrate, acetate and propionate, in KD mice by gas chromatography-mass spectrometry (GC-MS). Moreover, the reduced expression of SCFAs transporters, monocarboxylate transporter 1 (MCT-1) and sodium-dependent monocarboxylate transporter 1 (SMCT-1), was also shown in KD mice by western blot and RT-qPCR analyses. As expected, the decrease of fecal SCFAs production and barrier dysfunction were improved by oral C. butyricum treatment but was deteriorated by antibiotics. In vitro, butyrate, not acetate or propionate, increased the expression of phosphatase MKP-1 to dephosphorylate activated JNK, ERK1/2 and p38 MAPK against excessive inflammation in RAW264.7 macrophages. It suggests a new insight into probiotics and their metabolites supplements to treat KD.

Role of miR-300-3p in Leydig cell function and differentiation: A therapeutic target for obesity-related testosterone deficiency.

MicroRNAs (miRNAs) regulate various cellular functions, but their specific roles in the regulation of Leydig cells (LCs) have yet to be fully understood. Here, we found that the expression of miR-300-3p varied significantly during the differentiation from progenitor LCs (PLCs) to adult LCs (ALCs). High expression of miR-300-3p in PLCs inhibited testosterone production and promoted PLC proliferation by targeting the steroidogenic factor-1 (Sf-1) and transcription factor forkhead box O1 (FoxO1) genes, respectively. As PLCs differentiated into ALCs, the miR-300-3p expression level significantly decreased, which promoted testosterone biosynthesis and suppressed proliferation of ALCs by upregulating SF-1 and FoxO1 expression. The LH/METTL3/SMURF2/SMAD2 cascade pathway controlled miR-300-3p expression, in which luteinizing hormone (LH) upregulated SMAD-specific E3 ubiquitin protein ligase 2 (SMURF2) expression through methyltransferase like 3 (METTL3)-mediated Smurf2 N6-methyladenosine modification. The Smurf2 then suppressed miR-300 transcription by inhibiting SMAD family member 2 (SMAD2) binding to the promoter of miR-300. Notably, miR-300-3p was associated with an obesity-related testosterone deficiency in men and the inhibition of miR-300-3p effectively rescued testosterone deficiency in obese mice. These findings suggested that miR-300-3p plays a pivotal role in LC differentiation and function, and could be a promising diagnostic or therapeutic target for obesity-related testosterone deficiency.

High-efficiency and reliable same-parent thermoelectric modules using Mg3Sb2-based compounds.

Thermoelectric modules can convert waste heat directly into useful electricity, providing a clean and sustainable way to use fossil energy more efficiently. Mg3Sb2-based alloys have recently attracted considerable interest from the thermoelectric community due to their nontoxic nature, abundance of constituent elements and excellent mechanical and thermoelectric properties. However, robust modules based on Mg3Sb2 have progressed less rapidly. Here, we develop multiple-pair thermoelectric modules consisting of both n-type and p-type Mg3Sb2-based alloys. Thermoelectric legs based on the same parent fit into each other in terms of thermomechanical properties, facilitating module fabrication and ensuring low thermal stress. By adopting a suitable diffusion barrier layer and developing a new joining technique, an integrated all-Mg3Sb2-based module demonstrates a high efficiency of 7.5% at a temperature difference of 380 K, exceeding the state-of-the-art same-parent thermoelectric modules. Moreover, the efficiency remains stable during 150 thermal cycling shocks (∼225 h), demonstrating excellent module reliability.

Assessing Cerebral Oxygen Metabolism Changes in Patients With Preeclampsia Using Voxel-Based Morphometry of Oxygen Extraction Fraction Maps in Magnetic Resonance Imaging.

OBJECTIVE: The objective of this study was to analyze the different brain oxygen metabolism statuses in preeclampsia using magnetic resonance imaging and investigate the factors that affect cerebral oxygen metabolism in preeclampsia. MATERIALS AND METHODS: Forty-nine women with preeclampsia (mean age 32.4 years; range, 18-44 years), 22 pregnant healthy controls (PHCs) (mean age 30.7 years; range, 23-40 years), and 40 non-pregnant healthy controls (NPHCs) (mean age 32.5 years; range, 20-42 years) were included in this study. Brain oxygen extraction fraction (OEF) values were computed using quantitative susceptibility mapping (QSM) plus quantitative blood oxygen level-dependent magnitude-based OEF mapping (QSM + quantitative blood oxygen level-dependent imaging or QQ) obtained with a 1.5-T scanner. Voxel-based morphometry (VBM) was used to investigate the differences in OEF values in the brain regions among the groups. RESULTS: Among the three groups, the average OEF values were significantly different in multiple brain areas, including the parahippocampus, multiple gyri of the frontal lobe, calcarine, cuneus, and precuneus (all P-values were less than 0.05, after correcting for multiple comparisons). The average OEF values of the preeclampsia group were higher than those of the PHC and NPHC groups. The bilateral superior frontal gyrus/bilateral medial superior frontal gyrus had the largest size of the aforementioned brain regions, and the OEF values in this area were 24.2 ± 4.6, 21.3 ± 2.4, and 20.6 ± 2.8 in the preeclampsia, PHC, and NPHC groups, respectively. In addition, the OEF values showed no significant differences between NPHC and PHC. Correlation analysis revealed that the OEF values of some brain regions (mainly involving the frontal, occipital, and temporal gyrus) were positively correlated with age, gestational week, body mass index, and mean blood pressure in the preeclampsia group (r = 0.361-0.812). CONCLUSION: Using whole-brain VBM analysis, we found that patients with preeclampsia had higher OEF values than controls.

Survival rate prediction of nasopharyngeal carcinoma patients based on MRI and gene expression using a deep neural network.

To achieve a better treatment regimen and follow-up assessment design for intensity-modulated radiotherapy (IMRT)-treated nasopharyngeal carcinoma (NPC) patients, an accurate progression-free survival (PFS) time prediction algorithm is needed. We propose developing a PFS prediction model of NPC patients after IMRT treatment using a deep learning method and comparing that with the traditional texture analysis method. One hundred and fifty-one NPC patients were included in this retrospective study. T1-weighted, proton density and dynamic contrast-enhanced magnetic resonance (MR) images were acquired. The expression level of five genes (HIF-1α, EGFR, PTEN, Ki-67, and VEGF) and infection of Epstein-Barr (EB) virus were tested. A residual network was trained to predict PFS from MR images. The output as well as patient characteristics were combined using a linear regression model to provide a final PFS prediction. The prediction accuracy was compared with that of the traditional texture analysis method. A regression model combining the deep learning output with HIF-1α expression and Epstein-Barr infection provides the best PFS prediction accuracy (Spearman correlation R2  = 0.53; Harrell's C-index = 0.82; receiver operative curve [ROC] analysis area under the curve [AUC] = 0.88; log-rank test hazard ratio [HR] = 8.45), higher than a regression model combining texture analysis with HIF-1α expression (Spearman correlation R2  = 0.14; Harrell's C-index =0.68; ROC analysis AUC = 0.76; log-rank test HR = 2.85). The deep learning method does not require a manually drawn tumor region of interest. MR image processing using deep learning combined with patient characteristics can provide accurate PFS prediction for nasopharyngeal carcinoma patients and does not rely on specific kernels or tumor regions of interest, which is needed for the texture analysis method.

Dioscin induces osteosarcoma cell apoptosis by upregulating ROS-mediated P38 MAPK signaling.

Osteosarcoma is the most common primary malignant bone tumor in children and adolescents. Many patients with osteosarcoma readily develop resistance to chemotherapy and have an extremely dismal prognosis. Dioscin, a saponin, is known to exhibit potent anticancer activities and induce cellular death of a variety of cancer types. However, the inhibitory effect of dioscin on osteosarcoma cells and its underlying mechanisms have not been fully elucidated. We investigated the responses of human U2-OS and MG63 osteosarcoma cells to dioscin with regard to proliferation, apoptosis, migration, and invasion, and studied the effect of dioscin on MAPK-related proteins by western blot analysis assays. Dioscin inhibited osteosarcoma cell proliferation, migration, and invasion. Moreover, it induced osteosarcoma cell apoptosis via reactive oxygen species (ROS)-dependent apoptotic signaling. N-acetylcysteine, a reactive oxygen species inhibitor, suppressed dioscin-induced apoptosis, indicating that ROS play an essential role in dioscin-induced apoptosis. Western blot analysis assays showed that p38 MAPK was upregulated after dioscin treatment, and that dioscin induced apoptosis by upregulating ROS-mediated p38 MAPK signaling. Our study suggests that dioscin possesses antitumor activities against human osteosarcoma cells, inhibits osteosarcoma cell proliferation, migration and invasion, and induces osteosarcoma cell apoptosis through upregulating ROS-mediated p38 MAPK signaling. This study may provide a new therapeutic strategy and potential clinical applications for the treatment of osteosarcoma.

Pyomelanin production via heterologous expression of 4-hydroxyphenylpyruvate dioxygenase (HPPD) and construction of HPPD inhibitor screening model.

Melanin has an increasing market demand in cosmetics, food, medicine as well as aerospace due to its unique properties. Heterologous expression of 4-hydroxyphenylpyruvate dioxygenase (HPPD) from the melanin-producing strain Streptomyces fungicidicus NW-EN1 in Escherichia coli shortened the fermentation cycle of melanin. HPPD catalyzed 4-hydrophenylpyruvate (HPP) to form homologous acid (HGA) and finally form melanin. The purified melanin had the highest absorption peak at 460 nm. Fourier transform infrared spectroscopy and scanning electron microscope scanning showed that the pigment had universal characteristic peaks. The presence of HGA, a predictor of pyomelanin, was identified by high-performance liquid chromatography analysis. The recombinant E. coli produced 804.4 ± 5.9 mg/L pyomelanin within 48 h. Metal ions had a great influence on the production of pyomelanin. Pyomelanin was stable in response to light intensity and had a protective effect against bacteria under UV irradiation. Meanwhile, we utilized the chromogenic effect after whole-cell catalysis to reflect the inhibition of the HPPD inhibitors (mesotrione and isoxaflutole) on HPPD by observing the color change. As a rapid method to test the action of inhibitors, this method is expected to be useful for the development of HPPD-inhibiting herbicides.

Fluid Mechanics Approach to Perfusion Quantification: Vasculature Computational Fluid Dynamics Simulation, Quantitative Transport Mapping (QTM) Analysis of Dynamics Contrast Enhanced MRI, and Application in Nonalcoholic Fatty Liver Disease Classification.

OBJECTIVE: We quantify liver perfusion using quantitative transport mapping (QTM) method that is free of arterial input function (AIF). QTM method is validated in a vasculature computational fluid dynamics (CFD) simulation and is applied for processing dynamic contrast enhanced (DCE) MRI images in differentiating liver with nonalcoholic fatty liver disease (NAFLD) from healthy controls using pathology reference in a preclinical rabbit model. METHODS: QTM method was validated on a liver perfusion simulation based on fluid dynamics using a rat liver vasculature model and the mass transport equation. In the NAFLD grading task, DCE MRI images of 7 adult rabbits with methionine choline-deficient diet-induced nonalcoholic steatohepatitis (NASH), 8 adult rabbits with simple steatosis (SS) were acquired and processed using QTM method and dual-input two compartment Kety's method respectively. Statistical analysis was performed on six perfusion parameters: velocity magnitude | u | derived from QTM, liver arterial blood flow LBFa, liver venous blood flow LBFv, permeability Ktrans, blood volume Vp and extravascular space volume Ve averaged in liver ROI. RESULTS: In the simulation, QTM method successfully reconstructed blood flow, reduced error by 48% compared to Kety's method. In the preclinical study, only QTM |u| showed significant difference between high grade NAFLD group and low grade NAFLD group. CONCLUSION: QTM postprocesses DCE-MRI automatically through deconvolution in space and time to solve the inverse problem of the transport equation. Comparing with Kety's method, QTM method showed higher accuracy and better differentiation in NAFLD classification task. SIGNIFICANCE: We propose to apply QTM method in liver DCE MRI perfusion quantification.