Syk-dependent homologous recombination activation promotes cancer resistance to DNA targeted therapy.

Enhanced DNA repair is an important mechanism of inherent and acquired resistance to DNA targeted therapies, including poly ADP ribose polymerase (PARP) inhibition. Spleen associated tyrosine kinase (Syk) is a non-receptor tyrosine kinase acknowledged for its regulatory roles in immune cell function, cell adhesion, and vascular development. This study presents evidence indicating that Syk expression in high-grade serous ovarian cancer and triple-negative breast cancers promotes DNA double-strand break resection, homologous recombination (HR), and subsequent therapeutic resistance. Our investigations reveal that Syk is activated by ATM following DNA damage and is recruited to DNA double-strand breaks by NBS1. Once localized to the break site, Syk phosphorylates CtIP, a pivotal mediator of resection and HR, at Thr-847 to promote repair activity, particularly in Syk-expressing cancer cells. Inhibition of Syk or its genetic deletion impedes CtIP Thr-847 phosphorylation and overcomes the resistant phenotype. Collectively, our findings suggest a model wherein Syk fosters therapeutic resistance by promoting DNA resection and HR through a hitherto uncharacterized ATM-Syk-CtIP pathway. Moreover, Syk emerges as a promising tumor-specific target to sensitize Syk-expressing tumors to PARP inhibitors, radiation and other DNA-targeted therapies.

Modulating Carrier Dynamics in PdSe2: The Role of Pressure in Electronic and Phononic Interactions.

PdSe2 is a puckered transition metal dichalcogenide that has been reported to undergo a two-dimensional to three-dimensional structural transition under pressure. Here, we investigated the electronic and phononic evolution of PdSe2 under high pressure using pump-probe spectroscopy. We observed the electronic intraband and interband transitions occurring in the d orbitals of Pd, revealing the disappearance of the Jahn-Teller effect under high pressure. Furthermore, we found that the decay rates of interband recombination and intraband relaxation lifetimes change at 3 and 7 GPa, respectively. First-principles calculations suggest that the bandgap closure slows the decay rate of interband recombination after 3 GPa, while the saturation of phonon-phonon scattering is the main reason for the relatively constant intraband relaxation lifetime. Our work provides a novel perspective for understanding the evolution of the electron and modulation of the carrier dynamics by phonons under pressure.

Ultrafast Carrier Relaxation Dynamics in a Nodal-Line Semimetal PtSn4.

Topological Dirac nodal-line semimetals host topologically nontrivial electronic structure with nodal-line crossings around the Fermi level, which could affect the photocarrier dynamics and lead to novel relaxation mechanisms. Herein, by using time- and angle-resolved photoemission spectroscopy, we reveal the previously inaccessible linear dispersions of the bulk conduction bands above the Fermi level in a Dirac nodal-line semimetal PtSn4, as well as the momentum and temporal evolution of the gapless nodal lines. A surprisingly ultrafast relaxation dynamics within a few hundred femtoseconds is revealed for photoexcited carriers in the nodal line. Theoretical calculations suggest that such ultrafast carrier relaxation is attributed to the multichannel scatterings among the complex metallic bands of PtSn4 via electron-phonon coupling. In addition, a unique dynamic relaxation mechanism contributed by the highly anisotropic Dirac nodal-line electronic structure is also identified. Our work provides a comprehensive understanding of the ultrafast carrier dynamics in a Dirac nodal-line semimetal.

Exosomes From Muscle-Derived Stem Cells Repair Peripheral Nerve Injury by Inhibiting Ferroptosis via the Keap1-Nrf2-Ho-1 Axis.

Currently, the clinical outcomes of peripheral nerve injuries are suboptimal, highlighting the urgent need to understand the mechanisms of nerve injury to enhance treatment strategies. Muscle-derived stem cells (MDSCs) are a diverse group of multipotent cells that hold promise for peripheral nerve regeneration due to their strong antioxidant and regenerative properties. Our research has revealed that severe ferroptosis occurs in the sciatic nerve and ipsilateral dorsal root ganglion following sciatic nerve injury. Interestingly, we have observed that MDSC-derived exosomes effectively suppress cell ferroptosis and enhance cell viability in Schwann cells and dorsal root ganglion cells. Treatment with exosomes led to increased expression of BDNF and P62 in Schwann cells, decreased expression of Keap1, Nrf2, and HO-1 in Schwann cells, and upregulated dorsal root ganglion cells. Rats treated with exosomes exhibited improvements in sciatic nerve function, sensitivity to stimuli, and reduced muscle atrophy, indicating a positive impact on post-injury recovery. In conclusion, our findings demonstrate the occurrence of ferroptosis in the sciatic nerve and dorsal root ganglion post-injury, with MDSC exosomes offering a potential therapeutic strategy by inhibiting ferroptosis, activating the Keap1-Nrf2-HO-1 pathway, and optimizing the post-injury repair environment.

Imatinib adherence prediction using machine learning approach in patients with gastrointestinal stromal tumor.

BACKGROUND: Nonadherence to imatinib is common in patients with gastrointestinal stromal tumor (GIST), which is associated with poor prognosis and financial burden. The primary aim of this study was to investigate the adherence rate in patients with GIST and subsequently develop a model based on machine learning (ML) and deep learning (DL) techniques to identify the associated factors and predict the risk of imatinib nonadherence. METHODS: All eligible patients completed four sections of questionnaires. After the data set was preprocessed, statistically significance variables were identified and further processed to modeling. Six ML and four DL algorithms were applied for modeling, including eXtreme gradient boosting, light gradient boosting machine (LGBM), categorical boosting, random forest, support vector machine, artificial neural network, multilayer perceptron, NaiveBayes, TabNet, and Wide&Deep. The optimal ML model was used to identify potential factors for predicting adherence. RESULTS: A total of 397 GIST patients were recruited. Nonadherence was observed in 185 patients (53.4%). LGBM exhibited superior performance, achieving a mean f1_score of 0.65 and standard deviation of 0.12. The predominant indicators for nonadherent prediction of imatinib were cognitive functioning, whether to perform therapeutic drug monitoring (if_TDM), global health status score, social support, and gender. CONCLUSIONS: This study represents the first real-world investigation using ML techniques to predict risk factors associated with imatinib nonadherence in patients with GIST. By highlighting the potential factors and identifying high-risk patients, the multidisciplinary medical team can devise targeted strategies to effectively address the daily challenges of treatment adherence.

Identification and fungicides sensitivity evaluation of the causal agent of cobweb disease on Lyophyllum decastes in China.

BACKGROUND: Cobweb disease is a fungal disease that commonly affects the cultivation and production of edible mushrooms, leading to serious yield and economic losses. It is considered a major fungal disease in the realm of edible mushrooms. The symptoms of cobweb disease were found during the cultivation of Lyophyllum decastes. This study aimed to identify the causative pathogen of cobweb disease and evaluate effective fungicides, providing valuable insights for field control and management of L. decastes cobweb disease. RESULTS: The causal agent of cobweb disease was isolated from samples infected and identified as Cladobotryum mycophilum based on morphological and cultural characteristics, as well as multi-locus phylogeny analysis (ITS, RPB1, RPB2, and TEF1-α). Pathogenicity tests further confirmed C. mycophilum as the responsible pathogen for this condition. Among the selected fungicides, Prochloraz-manganese chloride complex, Trifloxystrobin, tebuconazole, and Difenoconazole exhibited significant inhibitory effects on the pathogen's mycelium, with EC50 values of 0.076 µg/mL, 0.173 µg/mL, and 0.364 µg/mL, respectively. These fungicides can serve as references for future field control of cobweb disease in L. decastes. CONCLUSION: This study is the first report of C. mycophilum as the causing agent of cobweb disease in L. decastes in China. Notably, Prochloraz-manganese chloride complex demonstrated the strongest inhibitory efficacy against C. mycophilum.

Effects of biomass burning on CO, HCN, C2H6, C2H2 and H2CO during long-term FTIR measurements in Hefei, China.

High-resolution solar absorption spectra were continuously collected by a ground-based Fourier transform infrared (FTIR) spectrometer to retrieve the total column of carbon monoxide (CO), hydrogen cyanide (HCN), ethane (C2H6), acetylene (C2H2), and formaldehyde (H2CO). The time series and variation characteristics of these gases were analyzed. The biomass combustion process is identified by using the correlations between the monthly mean deviations of HCN, C2H6, C2H2 and H2CO versus CO and satellite fire point data. The months with high correlation coefficients (R > 0.8) and peaks of fire point number are considered to be with biomass combustion occurrence. The emissions of HCN, C2H6, C2H2 and H2CO in Anhui were estimated using the enhancement ratios of gases to CO in these months when biomass combustion was the main driving factor of gas concentration change. The study proved the ability of FTIR system in inferring the period during biomass combustion and estimating emissions of the trace gases concerning biomass combustion.

Environmentally Relevant Concentrations of Tetrabromobisphenol A Exposure Impends Neurovascular Formation through Perturbing Mitochondrial Metabolism in Zebrafish Embryos and Human Primary Endothelial Cells.

Tetrabromobisphenol A (TBBPA), the most extensively utilized brominated flame retardant, has raised growing concerns regarding its environmental and health risks. Neurovascular formation is essential for metabolically supporting neuronal networks. However, previous studies primarily concerned the neuronal injuries of TBBPA, its impact on the neurovascularture, and molecular mechanism, which are yet to be elucidated. In this study, 5, 30, 100, 300 µg/L of TBBPA were administered to Tg (fli1a: eGFP) zebrafish larvae at 2-72 h postfertilization (hpf). The findings revealed that TBBPA impaired cerebral and ocular angiogenesis in zebrafish. Metabolomics analysis showed that TBBPA-treated neuroendothelial cells exhibited disruption of the TCA cycle and the Warburg effect pathway. TBBPA induced a significant reduction in glycolysis and mitochondrial ATP production rates, accompanied by mitochondrial fragmentation and an increase in mitochondrial reactive oxygen species (mitoROS) production in neuroendothelial cells. The supplementation of alpha-ketoglutaric acid, a key metabolite of the TCA cycle, mitigated TBBPA-induced mitochondrial damage, reduced mitoROS production, and restored angiogenesis in zebrafish larvae. Our results suggested that TBBPA exposure impeded neurovascular injury via mitochondrial metabolic perturbation mediated by mitoROS signaling, providing novel insight into the neurovascular toxicity and mode of action of TBBPA.

Hybrid mode for absorption enhancement in the Ga2O3 nanocavity photodetector with grating electrodes.

Gallium oxide (G a 2 O 3) photodetectors have drawn increased interest for their widespread applications ranging from military to civil. Due to the inherent oxygen vacancy defects, they seriously suffer from trade-offs that make them incompetent for high-responsivity, quick-response detection. Herein, a G a 2 O 3 nanocavity photodetector assisted with grating electrodes is designed to break the constraint. The proposed structure supports both the plasmonic mode and the Fabry-Perot (F-P) mode. Numerical calculations show that the absorption of 99.8% is realized for ultra-thin G a 2 O 3 (30 nm), corresponding to a responsivity of 12.35 A/W. Benefiting from optical mechanisms, the external quantum efficiency (EQE) reaches 6040%, which is 466 times higher than that of bare G a 2 O 3 film. Furthermore, the proposed photodetector achieves a polarization-dependent dichroism ratio of 9.1, enabling polarization photodetection. The grating electrodes also effectively reduce the transit time of the photo-generated carriers. Our work provides a sophisticated platform for developing high-performance G a 2 O 3 photodetectors with the advantages of simplified fabrication processes and multidimensional detection.

High-enhancement photoluminescence of monolayer MoS2 in hybrid plasmonic systems.

Monolayer molybdenum disulfide (M o S 2) has a weak light-matter interaction due to ultrathin thickness, which limits its potential application in lasing action. In this study, we propose a hybrid structure consisting of a nanocavity and Au nanoparticles to enhance the photon emission efficiency of monolayer M o S 2. Numerical simulations show that photoluminescence (PL) emission is significantly enhanced by introducing localized surface plasmon resonance (LSPR) to the proposed structure. Furthermore, an exciton energy band system is proposed to elucidate the physical mechanism of the PL process. By optimizing the spacer thickness, a high Purcell enhancement factor of 95 can be achieved. The results provided by this work pave the way to improve the PL efficiency of two-dimensional (2D) material, which constitutes a significant step towards the development of nanodevices such as nanolasers and sensors.

Interleukin-6 on postoperative day three as an early predictor of infections following laparoscopic gastric cancer resection.

BACKGROUND: To investigate the role of C-reactive protein (CRP), procalcitonin (PCT), and interleukin-6 (IL-6) as early predictors of infectious complications after laparoscopic gastric cancer surgery. METHODS: Patients who underwent laparoscopic gastric cancer surgery between January 2020 and June 2022 were retrospectively enrolled. IL-6, PCT, and CRP levels were assessed before surgery and on postoperative days (PODs) 3 and 5. Differences in serum IL-6, PCT, and CRP levels between the infected and non-infected groups were compared. The diagnostic accuracy was determined using the area under the receiver operating characteristic curve (AUC). RESULTS: A total of 206 patients were enrolled, and 21 patients (10.19%) developed postoperative infections. Serum IL-6, PCT, and CRP levels in the infected group were significantly higher than those in the non-infected group on PODs 3 and 5. IL-6 with an optimal cutoff value of 84.00 pg/mL (AUC 0.84), PCT with an optimal cutoff value of 1.39 ng/mL (AUC 0.80), CRP with an optimal cutoff value of 150.00 mg/L (AUC 0.76) on POD 3 had superior diagnostic accuracy in predicting postoperative infections. Multivariate analysis identified PCT and IL-6 levels on POD 3 as independent risk factors, the AUC of the combination of IL-6 and PCT was 0.89. The Delong test showed no difference between the AUC of IL-6 alone and IL-6 combined with PCT prediction (P = 0.07, Z = 1.81). CONCLUSIONS: IL-6 level on POD 3 is an excellent predictor of infectious complications following laparoscopic gastric cancer surgery. Patients with IL-6 levels lower than 84.00 pg/mL on POD 3 can ensure safe early discharge with a low probability of infection.

Advancements in genetic studies of mushrooms: a comprehensive review.

Genetic studies in mushrooms, driven by innovations such as CRISPR-Cas9 genome editing and RNA interference, transform our understanding of these enigmatic fungi and their multifaceted roles in agriculture, medicine, and conservation. This comprehensive review explores the rationale and significance of genetic research in mushrooms, delving into the ethical, regulatory, and ecological dimensions of this field. CRISPR-Cas9 emerges as a game-changing technology, enabling precise genome editing, targeted gene knockouts, and pathway manipulation. RNA interference complements these efforts by downregulating genes for improved crop yield and enhanced pest and disease resistance. Genetic studies also contribute to the conservation of rare species and developing more robust mushroom strains, fostering sustainable cultivation practices. Moreover, they unlock the potential for discovering novel medicinal compounds, offering new horizons in pharmaceuticals and nutraceuticals. As emerging technologies and ethical considerations shape the future of mushroom research, these studies promise to revolutionize our relationship with these fungi, paving the way for a more sustainable and innovative world.

Metasurfaces for generating higher-order Poincaré beams by polarization-selective focusing and overall elimination of co-polarization components.

Focused higher-order Poincaré (HOP) beams are of particular interest because they facilitate understanding the exotic properties of structured light and their applications in classical physics and quantum information. However, generating focused HOP beams using metasurfaces is challenging. In this study, we proposed a metasurface design comprising two sets of metal nanoslits for generating coaxially focused HOP beams. The nanoslits were interleaved on equispaced alternating rings. The initial rings started at the two adjacent Fresnel zones to provide opposite propagation phases for overall elimination of the co-polarization components. With the designed hyperbolic and helical profiles of the geometric phases, the two vortices of the opposite cross-circular-polarizations were formed and selectively focused, realizing HOP beams of improved quality. Simulations and experimental results demonstrated the feasibility of the proposed metasurface design. This study is of significance in the integration of miniaturized optical devices and enriches the application areas of metasurfaces.

A Combination of Preoperative Computed Tomography-Defined Sarcopenia and Systemic Inflammation on Survival in Patients with Poorly Differentiated Neuroendocrine Neoplasms Following Radical Resection.

This retrospective study of 122 patients with gastrointestinal poorly differentiated neuroendocrine neoplasms (GI-PDNEN) who underwent radical resection between January 2010 and December 2020 aimed to investigate the usefulness of combined computed tomography (CT)-defined sarcopenia and systemic inflammation to evaluate long-term prognoses for patients who underwent radical surgical resection. Sarcopenia, based on a pre-defined L3 skeletal muscle index cutoff value, was assessed using preoperative abdominal CT images. Patients (neuroendocrine carcinoma, 86 patients; mixed adenoneuroendocrine carcinoma, 36 patients) were divided into low-, intermediate-, and high-risk groups using sarcopenia scores and neutrophil-to-lymphocyte ratios (SNLRs). Higher SNLRs were significantly associated with higher age (P = 0.004), larger tumor size (P = 0.042), lower body mass index (P = 0.042), and lower hemoglobin (P = 0.001) and albumin (P = 0.031) levels. Multivariate analysis indicated that a higher SNLR was an independent risk factor for poor overall survival (OS, P = 0.01) and relapse-free survival (RFS, P = 0.001) in patients with GI-PDNEN postoperatively. Sarcopenia and a higher NLR were significantly associated with poor RFS and OS following radical resection. The SNLR had a definite predictive prognostic value in preoperatively identifying patients with GI-PDNEN and a probable poor long-term prognosis, especially those with neuroendocrine carcinoma.

Parental Exposure to Environmentally Relevant Concentrations of Bisphenol-A Bis(diphenyl phosphate) Impairs Vascular Development in Offspring through DNA/RNA Methylation-Dependent Transmission.

Bisphenol-A bis(diphenyl phosphate) (BDP) has been increasingly detected in indoor environmental and human samples. Little is known about its developmental toxicity, particularly the intergenerational effects of parental exposure. In this study, adult zebrafish were exposed to BDP at 30-30,000 ng/L for 28 days, with results showing that exposure did not cause a transfer of BDP or its metabolites to offspring. Vascular morphometric profiling revealed that parental exposure to BDP at 30 and 300 ng/L exerted significant effects on the vascular development of offspring, encompassing diverse alterations in multiple types of blood vessels. N6-Methyladenosine (m6A) methylated RNA immunoprecipitation sequencing of larvae in the 300 ng/L group revealed 378 hypomethylated and 350 hypermethylated m6A peaks that were identified in mRNA transcripts of genes crucial for vascular development, including the Notch/Vegf signaling pathway. Concomitant changes in 5 methylcytosine (m5C) DNA methylation and gene expression of m6A modulators (alkbh5, kiaa1429, and ythdf1) were observed in both parental gonads and offspring exposed to BDP. These results reveal that parental exposure to low concentrations of BDP caused offspring vascular disorders by interfering with DNA and RNA methylation, uncovering a unique DNA-RNA modification pattern in the intergenerational transmission of BDP's developmental toxicity.

Laparoscopic versus open gastrectomy for locally advanced gastric cancer after neoadjuvant chemotherapy: a comprehensive contrastive analysis with propensity score matching.

BACKGROUND: Laparoscopic gastrectomy (LG) is increasingly applied in locally advanced gastric cancer (LAGC) after neoadjuvant chemotherapy (NC). However, there is no study to comprehensively evaluate the clinicopathological, prognostic, and laboratory data such as nutrition, immune, inflammation-associated indexes, and tumor markers between LG and open gastrectomy (OG) for LAGC following NC. METHODS: The clinicopathological, prognostic, and laboratory data of LAGC patients with clinical stage of cT2-4aN1-3M0 who underwent gastrectomy after NC were retrospectively collected. The effects of LG and OG were compared after propensity score matching (PSM). RESULTS: This study enrolled 148 cases, of which 110 cases were included after PSM. The LG group had a shorter length of incision (P < 0.001) and was superior to OG group in terms of blood loss (P < 0.001), postoperative first flatus time (P < 0.001), and postoperative first liquid diet time (P = 0.004). No significant difference was found in postoperative complications (P = 0.482). Laboratory results showed that LG group had less reduced red blood cells (P = 0.039), hemoglobin (P = 0.018), prealbumin (P = 0.010) in 3 days after surgery, and less reduced albumin in 1 day (P = 0.029), 3 days (P = 0.015), and 7 days (P = 0.035) after surgery than the OG group. The systemic immune-inflammation index and systemic inflammatory response index were not significantly different between the two groups. As for oncological outcomes, there were no significant differences in postoperative tumor markers of CEA (P = 0.791), CA199 (P = 0.499), and CA724 (P = 0.378). The 5-year relapse-free survival rates (P = 0.446) were 46.9% and 43.3% in the LG and OG groups, with the 5-year overall survival rates (P = 0.742) being 46.7% and 52.1%, respectively; the differences were not statistically significant. Multivariate Cox regression analysis revealed that tumor size ≥ 4 cm (P = 0.021) and the absence of postoperative adjuvant chemotherapy (P = 0.012) were independent risk factors for overall survival. CONCLUSIONS: LG has faster gastrointestinal recovery, better postoperative nutritional status, and comparable oncological outcomes than OG, which can serve as an alternative surgical method for LAGC patients after NC.

First report of cobweb disease in Auricularia cornea caused by Hypomyces mycophilus in Guizhou, China.

Auricularia cornea is a widely cultivated mushroom in China, which has high medicinal values such as hemostaticity, analgesia, antioxidation and anti-tumor (Wu et al., 2019). In 2022, an investigation on edible mushroom diseases in Guizhou Province observed a suspected cobweb disease in an A. cornea growing factory, with up to 30% incidence. The pathogen first produced flocculent hyphae on the surface of the fruiting body of A. cornea, and then developed spider web-like aerial hyphae, covering the entire fruiting bodies. It hinders the normal growth of A. cornea, resulting in deformity and rot of the fruiting bodies. These symptoms seriously affect the quantity and quality of mushroom yields and cause huge economic losses. Three fungal isolates (GUCCX001, GUCCX002 and GUCCX003) were recovered from the diseased mushroom fruiting bodies and purified through single spore isolation. The colonies of three isolates spread rapidly on PDA, reaching 79-82 mm in seven days. The flocculent mycelium was whitish, and its reverse turned from yellowish to amber after 14 days. The branched conidiophores arising from aerial mycelia were septate and each cell contained several denticulate conidiogenous loci. Each denticle contained a single conidium. Conidia were observed at the tip of conidiophore branches and were 0-1-septate, oval or spherical, transparent, 5.2-11.3 × 11.7-18.7 µm (n = 35). Chlamydospores were visible as 3-4 thick-walled cells at the tip of lateral hyphal branches. Three isolates were tentatively identified as H. mycophilus based on their morphological characteristics similar to those described by Rogerson and Samuels (1993). The sequence of internal transcribed spacer (ITS) region (primers ITS5/ITS4) (Rehner and Samuels, 1994) and nuclear ribosomal large subunit (LSU) region (primers LR0R/LR5) (Vilgalys and Heste, 1990) of GUCCX001 (ITS: OP777905; LSU: OQ152071), GUCCX002 (ITS: OP862872; LSU: OQ152072) and GUCCX003 (ITS: OP862873; LSU: OP862873) were 99%-100% similar to H. mycophilus CBS 175.56 (ITS: MH857567; LSU: MH869110). Fifteen healthy fruiting bodies of A. cornea were inoculated by spraying spore suspension (106 conidia/mL) of the three isolates and five healthy fruiting bodies were sprayed with sterile water as control. All inoculated fruiting bodies were kept at 25 ℃. After three days, fruiting bodies of A. cornea treated with the spore suspension exhibited the same symptoms of cobweb as in the factory, while no symptom appeared in the control. Pathogens re-isolated from diseased fruiting bodies were confirmed to be H. mycophilus based on morphological characteristics, which fulfills the Koch's postulate. Zeng et al. (2017) reported H. mycophilus on the fruiting bodies of Auricularia sp. as a new record in Guangdong, China. H. mycophilus caused cobweb disease on A. auricula (Liu et al., 2020), A. cornea var. Li. (Cao et al., 2023) and A. heimuer (Zhang et al., 2023). To our knowledge, this is the first report of cobweb disease in A. cornea caused by H. mycophilus in Guizhou, China. Our findings will provide a basis for correct diagnosis and management of cobweb diseases on A. cornea.

EWOD Chip with Micro-Barrier Electrode for Simultaneous Enhanced Mixing during Transportation.

Digital microfluidic platforms have been extensively studied in biology. However, achieving efficient mixing of macromolecules in microscale, low Reynolds number fluids remains a major challenge. To address this challenge, this study presents a novel design solution based on dielectric electro-wetting (EWOD) by optimizing the geometry of the transport electrode. The new design integrates micro-barriers on the electrodes to generate vortex currents that promote mixing during droplet transport. This design solution requires only two activation signals, minimizing the number of pins required. The mixing performance of the new design was evaluated by analyzing the degree of mixing inside the droplet and quantifying the motion of the internal particles. In addition, the rapid mixing capability of the new platform was demonstrated by successfully mixing the sorbitol solution with the detection solution and detecting the resulting reaction products. The experimental results show that the transfer electrode with a micro-barrier enables rapid mixing of liquids with a six-fold increase in mixing efficiency, making it ideal for the development of EWOD devices.

Population Inversion and Dirac Fermion Cooling in 3D Dirac Semimetal Cd3As2.

Revealing the ultrafast dynamics of three-dimensional (3D) Dirac fermions is critical for both fundamental science and device applications. So far, how the cooling of 3D Dirac fermions differs from that of two-dimensional (2D) and whether there is population inversion are fundamental questions to be answered. Here we reveal the ultrafast dynamics of Dirac fermions in a model 3D Dirac semimetal Cd3As2 by time- and angle-resolved photoemission spectroscopy with a tunable probe photon energy. The energy- and momentum-resolved relaxation rate shows a linear dependence on the energy, suggesting Dirac fermion cooling through intraband relaxation. Moreover, a population inversion is reported based on the observation of accumulated photoexcited carriers in the conduction band with a lifetime of 3.0 ps. Our work provides direct experimental evidence for a long-lived population inversion in a 3D Dirac semimetal, which is in contrast to 2D graphene with a much shorter lifetime.

Arbitrary superposition of plasmonic orbital angular momentum states with nanostructures.

A kind of plasmonic nanostructure is proposed that can generate the arbitrary superposition of orbital angular momentum (OAM) states in surface plasmons (SPs), which is achieved by combining the segmented spirals with nanoslit pairs. The structures can independently modulate both the phase and amplitude of SP waves, and thus enable the superposition of two OAM states with arbitrary topological charges (TCs) as well as free control of their relative amplitudes. Superposed states distributed over the entire Bloch sphere and hybrid superposed states with different TCs were constructed and experimentally demonstrated. This work will offer more opportunities for multifunctional plasmonic devices.