Glycerophospholipid-driven lipid metabolic reprogramming as a common key mechanism in the progression of human primary hepatocellular carcinoma and cholangiocarcinoma.

Metabolic reprogramming, a key mechanism regulating the growth and recurrence of hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), still lacks effective clinical strategies for its integration into the precise screening of primary liver cancer. This study utilized ultra-high-performance liquid chromatography with quadrupole time-of-flight mass spectrometry to conduct a comprehensive, non-targeted metabolomics analysis, revealing significant upregulation of lipid metabolites such as phosphatidylcholine and lysophosphatidylcholine in patients with HCC and CCA, particularly within the glycerophospholipid metabolic pathway. Hematoxylin and eosin and immunohistochemical staining demonstrated marked upregulation of phospholipase A2 in tumor tissues, further emphasizing the potential of lipid metabolism as a therapeutic target and its important part in the course of cancer. This work provides a new viewpoint for addressing the clinical challenges associated with HCC and CCA, laying the groundwork for the broad application of early diagnosis and personalized treatment strategies, and ultimately aiming to provide tailored and precise therapeutic options for patients.

A Total Internal Reflection Microscopy (TIRM)-Based Approach for Direct Characterization of Polymer Brush Conformational Change in Aqueous Solution.

This study presents a novel approach utilizing total internal reflection microscopy (TIRM) to effectively characterize the swelling and collapse of polymer brushes in aqueous solutions. Zwitterionic poly(carboxybetaine methacrylate) (PCBMA) and nonionic poly[oligo(ethylene glycol) methyl ether methacrylate] (POEGMA) brushes are chosen as model systems. By investigation of an intriguing theory-experiment discrepancy observed during the measurement of near-wall hindered diffusion, valuable insights into the compressibility of polymer brushes are obtained, revealing their conformational information in aqueous solution. The results demonstrate that zwitterionic PCBMA brushes exhibit minimal antipolyelectrolyte effects in 0.1-10 mM NaCl solution but undergo significant swelling with increasing pH. On the other hand, nonionic POEGMA brushes exhibit similar responses to ionic strength as weak polyelectrolyte brushes. These unexpected findings enhance our understanding of polymer brushes beyond classical theories. The TIRM-based approach proves to be effective for characterizing polymer brushes and other soft nanomaterials.

Laparoscopic enucleation of tumors embedded in the pancreatic head: Safety and feasibility.

BACKGROUND: Surgical treatment for a benign or low-grade malignant tumor in the pancreatic head remains a challenge at present. As an organ-sparing procedure, enucleation is ideal. However, it is still controversial whether laparoscopic enucleation (LapEN) can be safely performed for a pancreatic head tumor, especially a deeply embedded one. METHODS: The cases who underwent LapEN of a pancreatic tumor from January 2014 to September 2022 in our hospital were collected and analyzed. RESULTS: A total of 151 cases were collected. The incidence of pancreatic fistula (PF, grade B) was 21.9 %. No patient developed PF (grade C) or died. Compared with enucleating a tumor in the distal pancreas (N = 98), enucleating a tumor in the pancreatic head (N = 53) showed a longer operation time and a higher incidence of conversion. The cases with a tumor in the pancreatic head were then divided into the group with a deeply embedded tumor (N = 32) and the group with a superficial tumor (N = 21). The embedded group had a smaller tumor size and a higher proportion of insulinoma. There were no statistical differences in the parameters of operation time, blood loss and incidence of complications between the two groups. The outcomes of enucleating a tumor deeply embedded in the proximal and distal pancreas were further analyzed, which indicated no statistical differences in clinical parameters between the two groups. CONCLUSION: LapEN of a tumor in the pancreatic head is feasible and safe, even for a deeply embedded tumor.

Superoxide radical derived metal-free spiro-OMeTAD for highly stable perovskite solar cells.

Lithium salt-doped spiro-OMeTAD is widely used as a hole-transport layer (HTL) for high-efficiency n-i-p perovskite solar cells (PSCs), but unfortunately facing awkward instability for commercialization arising from the intrinsic Li+ migration and hygroscopicity. We herein demonstrate a superoxide radicals (•O2-) derived HTL of metal-free spiro-OMeTAD with remarkable capability of avoiding the conventional tedious oxidation treatment in air for highly stable PSCs. Present work explores the employing of variant-valence Eu(TFSI)2 salts that could generate •O2- for facile and adequate pre-oxidation of spiro-OMeTAD, resulting in the HTL with dramatically increased conductivity and work function. Comparing to devices adopting HTL with LiTFSI doping, the •O2--derived spiro-OMeTAD increases the PSCs efficiency up to 25.45% and 20.76% for 0.05 cm2 active area and 6 × 6 cm2 module, respectively. State-of-art PSCs employing such metal-free HTLs are also demonstrated to show much-improved environmental stability even under harsh conditions, e.g., maintaining over 90% of their initial efficiency after 1000 h of operation at the maximum power point and after 80 light-thermal cycles under simulated low earth orbit conditions, respectively, indicating the potentials of developing metal-free spiro-OMeTAD for low-cost and shortened processing of perovskite photovoltaics.

Molecular Investigation of the Self-Assembly Mechanism Underlying Polydopamine Coatings: The Synergistic Effect of Typical Building Blocks Acting on Interfacial Adhesion.

Polydopamine (PDA) is well known as a mussel-inspired adhesive material composed of oligomeric heteropolymers. However, the conventional eumelanin-like structural assumption of PDA seems deficient in explaining its interfacial adhesion. To determine the decisive mechanism of PDA coating formation, experiments and simulations were performed in this study. 5,6-Dihydroxyindole (DHI), the signature building block of eumelanin, was introduced as the control group. Various typical building blocks in PDA were quantified by physicochemical characterizations, and the polar-group-dominated interfacial interaction was evaluated by classic molecular dynamics and metadynamics methods. Aminoethyl has been proven to be the key functional group inducing the adsorption of PDA on the hydroxylated silica substrates, while DHI shows limited adhesion to the substrate due to the absence of aminoethyl as the catechol-indole structure of DHI exhibits poor affinity to the silica surface. Pyrrole carboxylic acid, as an oxidative product detected from PDA/DHI, is unfavorable for its adhesion to silica substrates. Overall, the coating formation and self-aggregating precipitation of PDA are two competitive aminoethyl-consuming paths; thus, the in situ oxidative coupling of dopamine is indispensable for the PDA coating preparation. The collected PDA precipitates can no longer present satisfactory coating forming behavior, resulting from a shortage of aminoethyl moieties.

Assessment of Population Genetic Diversity of Medicinal Meconopsis integrifolia (Maxim.) Franch. Using Newly Developed SSR Markers.

Meconopsis integrifolia is an endangered Tibetan medicinal plant with significant medicinal and ornamental value. Understanding its genetic diversity and structure is crucial for its sustainable utilization and effective conservation. Here, we develop a set of SSR markers based on transcriptome data to analyze the genetic diversity and structure of 185 individuals from 16 populations of M. integrifolia. The results indicate that M. integrifolia exhibits relatively high genetic diversity at the species level (the percentage of polymorphic bands PPB = 91.67%, Nei's genetic diversity index He = 0.2989, Shannon's information index I = 0.4514) but limited genetic variation within populations (PPB = 12.08%, He = 0.0399, I = 0.0610). The genetic differentiation among populations is relatively high (the coefficient of gene differentiation GST = 0.6902), and AMOVA analysis indicates that 63.39% of the total variation occurs among populations. This suggests that maintaining a limited number of populations is insufficient to preserve the overall diversity of M. integrifolia. Different populations are categorized into four representative subclusters, but they do not cluster strictly according to geographical distribution. Limited gene flow (Nm = 0.2244) is likely the main reason for the high differentiation among these populations. Limited seed and pollen dispersal abilities, along with habitat fragmentation, may explain the restricted gene flow among populations, highlighting the necessity of conserving as many populations in the wild as possible.

Construction of a NETosis-related gene signature for predicting the prognostic status of sepsis patients.

Background: Sepsis is a common traumatic complication of response disorder of the body to infection. Some studies have found that NETosis may be associated with the progression of sepsis. Methods: Data of the sepsis samples were acquired from Gene Expression Omnibus (GEO) database. Gene set enrichment score was calculated using single-sample gene set enrichment analysis (ssGSEA). Weighted gene co-expression network analysis (WGCNA), protein-protein interaction (PPI) networks analysis, and stepwise multivariable regression analysis were performed to identify NETosis-associated genes for sepsis prognosis. To assess the infiltration of immune cells, the ESTIMATE and CIBERPSORT algorithms were used. Functional enrichment analysis was conducted in the clusterProfiler package. Results: Different programmed death pathways were abnormally activated in sepsis patients as compared to normal samples. We screened five important NETosis associated genes, namely, CEACAM8, PGLYRP1, MAPK14, S100A12, and LCN2. These genes were significantly positively correlated with entotic cell death and ferroptosis and negatively correlated with autophagy. A clinical prognostic model based on riskscore was established using the five genes. The ROC curves of the model at 7 days, 14 days and 21 days all had high AUC values, indicating a strong stability of the model. Patients with high riskscore had lower survival rate than those with low riskscore. After the development of a nomogram, calibration curve and decision curve evaluation also showed a strong prediction performance and reliability of the model. As for clinicopathological features, older patients and female patients had a relatively high riskscore. The riskscore was significantly positively correlated with cell cycle-related pathways and significantly negatively correlated with inflammatory pathways. Conclusion: We screened five NETosis-associated genes that affected sepsis prognosis, and then established a riskscore model that can accurately evaluate the prognosis and survival for sepsis patients. Our research may be helpful for the diagnosis and clinical treatment of sepsis.

The role of ventral hippocampal-medial prefrontal glutamatergic pathway on the non-affected side in post-stroke cognitive impairment.

Elucidate the pathogenesis mechanism of post-stroke cognitive impairment (PSCI) can help to develop precision interventions. In this study, we established a mouse model of PSCI using the photochemical method, and behavioral tests including Y-maze and Novel object recognition task for accessing cognitive impairment were observed at week 2 post-stroke. Besides, synaptic plasticity, theta nerve oscillatory and the activity of glutamatergic neurons related to the ventral hippocampal-medial prefrontal glutamatergic neural pathway in the non-affected hemisphere (contralateral hemisphere to the lesion site) were observed. The result indicated the cognitive function declined at week 2 post-stroke. Synaptic plasticity, theta nerve oscillatory synchronization and the activity of glutamatergic neurons of the ventral hippocampal-medial prefrontal glutamatergic neural pathway in the non-affected hemisphere was down-regulated in the PSCI group compared to those of the SHAM group. Therefore, we concluded that the declined function of the ventral hippocampal-medial prefrontal glutamatergic pathway in the non-affected hemisphere is a biomarker in the occurrence of cognitive dysfunction after stroke.

Trait Variation and Spatiotemporal Dynamics across Avian Secondary Contact Zones.

A secondary contact zone (SCZ) is an area where incipient species or divergent populations may meet, mate, and hybridize. Due to the diverse patterns of interspecific hybridization, SCZs function as field labs for illuminating the on-going evolutionary processes of speciation and the establishment of reproductive isolation. Interspecific hybridization is widely present in avian populations, making them an ideal system for SCZ studies. This review exhaustively summarizes the variations in unique traits within avian SCZs (vocalization, plumage, beak, and migratory traits) and the various movement patterns of SCZs observed in previous publications. It also highlights several potential future research directions in the genomic era, such as the relationship between phenotypic and genomic differentiation in SCZs, the genomic basis of trait differentiation, SCZs shared by multiple species, and accurate predictive models for forecasting future movements under climate change and human disturbances. This review aims to provide a more comprehensive understanding of speciation processes and offers a theoretical foundation for species conservation.

GLDA exhibits advantages in the phytoextraction of Cd and Ni in land-applied municipal sludge.

Landscape utilization is a green and environment-friendly way of disposing of compost sludge. Garden plants can extract heavy metals from the sludge of land use, but the effect is not enough to be widely used. Chelating agents have been found to facilitate the extraction of heavy metals from plants and are expected to be popularized if they are also environmentally friendly. In this study, the effects of methylglycinediacetic acid trisodium salt (MGDA), tetrasodium glutamate diacetate (GLDA), and ethylene diamine tetraacetate (EDTA) on the extraction of Ni and Cd from compost sludge by Symphytum officinale L. were studied through the pot experiment. Compared with the control group, the application of 5-10 mmol kg-1 MGDA and 1-9 mmol kg-1 GLDA promoted plant growth, while the application of 3-4 mmol kg-1 EDTA inhibited plant growth. The highest Ni content in shoots appeared in 4 mmol kg-1 GLDA treatment, which was 4.2 times that of the CK group. The highest shoot Cd concentration appeared in 4 mmol kg-1 EDTA treatment, 6.5 times that of CK. The promotion effects of the three reagents on the acid-extractable state of Cd were similar, while that of GLDA on the acid-extractable state of Ni was outstanding. The results of this study suggested that S. officinale could be a potential phytoextraction plant for Cd and Ni, and GLDA could friendly promote the Ni phytoextraction ability of the plant. The study provides a new and efficient method for phytoremediation of heavy metals in soil.

Palladium-catalyzed 1,1-aminoxylation of 3-butenoic acid with 2-alkynylanilines.

Herein, a palladium-catalyzed 1,1-aminoxylation of 3-butenoic acid and 2-alkynylanilines has been developed, achieving the installation of two distinct heteroatom motifs across an olefin skeleton. The strategy features a high step and atom economy and good functional group tolerance, which outlines an efficient approach for simultaneously building up γ-butylactone and indole skeletons. Notably, an external ligand, 2,9-dimethyl-1,10-phenanthroline, has been used to succeed in this protocol to effectively suppress the production of indole byproducts.

Pd-catalyzed Markovnikov selective oxidative amination of 4-pentenoic acid.

Pd-catalyzed regioselective amination of unactivated alkene remains a challenge and is of great interest. Herein, a palladium-catalyzed and ligand-controlled strategy for the Markovnikov selective oxidative amination of 4-pentenoic acid has been described. The protocol effectively reverses the carboxylic acid-directed anti-Markovnikov selectivity in oxidative amination of 4-pentenoic acid, successfully constructing γ-ketoamide derivatives.

Triple synergistic sterilization of Prussian blue nanoparticle-doped chitosan/gelatin packaging film for enhanced food preservation.

To mitigate food spoilage caused by microbial contamination and extend the shelf life of food, antibacterial and eco-friendly biological packaging materials as an alternative to petroleum-based plastics is encouraged. Herein, an innovative and green composite film with triple antibacterial activity has been fabricated by introducing prussian blue nanoparticles (PBNPs) into chitosan (CS)-based films blended with gelatin (Gel) for the preservation of food, named CS/Gel/PB film. Due to the incorporation of PBNPs, CS/Gel/PB film exhibits enhanced mechanical, barrier and water resistance, and thermal abilities. The inherent bacterial trapping and killing capabilities of CS (contact killing), photothermal/photodynamic killing based on the excellent photothermal property of PBNPs under NIR irradiation synergistically facilitate the sterilization against Escherichia coli and Staphylococcus aureus (antibacterial ratio = 99.99 %). The film exhibits outstanding preservation capability in product storage, significantly extending the shelf life of strawberry and pork to 15 and 7 days, respectively. Meanwhile, the cytotoxicity assessment of CS/Gel/PB against HepG2 cells ascertains a cell viability exceeding 96 %, indicating a negligible toxicity level. Additionally, this film also exhibits superior biodegradability (preliminary degradation on the 10th day and completion on the 40th day) compared with PE film. Overall, these properties demonstrate great potential of CS/Gel/PB film as a novel packaging material.

Asymmetric Wettability Hydrogel Surfaces for Enduring Electromyographic Monitoring.

Hydrogel electrode interfaces have shown tremendous promise in the acquisition of surface electromyography (EMG) signals. However, the perspiration or moisture environments will trigger the deadhesion between hydrogel electrodes and human skin. Despite the hydrophobic/hydrophilic surfaces can perform the anti-moisture or adhesion respectively, it remains a challenge to integrally form a Janus hydrogel with homogeneous mechanical elasticity and electronic performance. Herein, a surface induction strategy is proposed to approach the hydrophobic/hydrophilic hydrogel surfaces. The hydrophobic interaction between surfactants and molds regulates the distribution of hydrophobic/hydrophilic monomers on the surface. The hydrophobic molds induce a hydrophilic hydrogel surface, while the hydrophilic molds induce a hydrophobic surface. It presents a new phenomenon of reversal wettability inducing and optional hydrogel surfaces. The integral Janus hydrogel can be easily obtained by the hydrophilic molds. Balance of adhesion, elasticity, and conductivity endows the hydrogel electrode patch with durable conformal adhesion and high-fidelity EMG signals even in the sweaty epidermis due to the asymmetric wettability surfaces. This hydrogel performs the quantitative description of muscle strength and accurate fatigue assessment. It offers a reliable candidate for future practical applications in continuous digital healthcare and intelligent human-machine interaction, even the Metaverse.

Palladium-catalyzed cascade of aza-Wacker and Povarov reactions of aryl amines and 1,6-dienes for hexahydro-cyclopenta[b]quinoline framework.

Palladium catalyzed tandem reaction represents a one-pot synthetic approach to efficiently synthesize complex functionalized molecules while reducing synthetic steps, aligning with the principles of green chemistry. However, achieving a direct cascade of the aza-Wacker and Povarov reactions in one-pot synthesis presents a challenge due to substrate compatibility issues between the two reactions. In this work, we describe an aza-Wacker/Povarov reaction employing a highly electrophilic palladium catalyst, which effectively converts anilines and 1,6-dienes into hexahydro-cyclopenta[b]quinolines. The optimized conditions yield up to 79%, with a diastereoselectivity > 20:1. Substrate range testing reveals compatibility with various sensitive functional groups, and successful late-stage modifications are performed on several natural products and drug molecules, demonstrating the versatility and practicality of the method. Additionally, a preliminary investigation into the reaction mechanism suggests an aza-Wacker process followed by a Povarov process.

A single session of sensorimotor rhythm neurofeedback enhances long-game performance in professional golfers.

Enhanced Sensorimotor Rhythm activity has been linked to increased automation in motor execution. Although existing research demonstrates the positive effects of SMR neurofeedback training on improving golf putting performance, its influence on golf long-game performance remains unexplored. This study sought to address this gap by involving seventeen professional female golfers (Age =24.63 ± 3.24 years, Handicap＝2.06 ± 1.18) in a crossover-designed experiment incorporating both NFT and a no-training control condition. During the study, participants executed 40 150-yard swings while receiving continuous SMR neurofeedback. Pre- and post-testing included visual analog scales to assess psychological processes associated with SMR activities, including attention engagement, conscious motor control, and physical relaxation levels. The results revealed that a single session of NFT effectively heightened SMR power irrespective of T1 (p = .02) or T2 (p = .03), which was observed with improved swing accuracy compared to the control conditions, particularly in "To Pin" (p = .04, the absolute distance to the hole after the ball comes to a stop). Subjective assessments further indicated that SMR NFT contributed to a sense of ease and tranquility during motor preparation for the golf swing (attention engagement: p = .01, conscious motor control: p = .033, physical relaxation: p = .013), and which offered valuable insights into the potential mechanisms underlying the impact of SMR NFT on long-game performance. Additionally, in such practical applications professional athletes can utilize our single-session neurofeedback protocol to train efficiently and cost-effectively before competitions, thereby enhancing their opportunity to achieve a higher rank.

Application of peripheral blood routine parameters in the diagnosis of influenza and Mycoplasma pneumoniae.

OBJECTIVES: Influenza and Mycoplasma pneumoniae infections often present concurrent and overlapping symptoms in clinical manifestations, making it crucial to accurately differentiate between the two in clinical practice. Therefore, this study aims to explore the potential of using peripheral blood routine parameters to effectively distinguish between influenza and Mycoplasma pneumoniae infections. METHODS: This study selected 209 influenza patients (IV group) and 214 Mycoplasma pneumoniae patients (MP group) from September 2023 to January 2024 at Nansha Division, the First Affiliated Hospital of Sun Yat-sen University. We conducted a routine blood-related index test on all research subjects to develop a diagnostic model. For normally distributed parameters, we used the T-test, and for non-normally distributed parameters, we used the Wilcoxon test. RESULTS: Based on an area under the curve (AUC) threshold of ≥ 0.7, we selected indices such as Lym# (lymphocyte count), Eos# (eosinophil percentage), Mon% (monocyte percentage), PLT (platelet count), HFC# (high fluorescent cell count), and PLR (platelet to lymphocyte ratio) to construct the model. Based on these indicators, we constructed a diagnostic algorithm named IV@MP using the random forest method. CONCLUSIONS: The diagnostic algorithm demonstrated excellent diagnostic performance and was validated in a new population, with an AUC of 0.845. In addition, we developed a web tool to facilitate the diagnosis of influenza and Mycoplasma pneumoniae infections. The results of this study provide an effective tool for clinical practice, enabling physicians to accurately diagnose and differentiate between influenza and Mycoplasma pneumoniae infection, thereby offering patients more precise treatment plans.

Value of prognostic nutritional index and controlling nutritional status score for advanced non-small cell lung cancer patients receiving PD-1 inhibitors.

OBJECTIVE: To explore the value of preoperative prognostic nutritional index (PNI) and controlling nutritional status (CONUT) score in predicting response and prognosis of patients with advanced non-small cell lung cancer (NSCLC) receiving programmed cell death protein 1 (PD-1) inhibitors. METHODS: A retrospective study was conducted in patients who received PD-1 inhibitors for advanced NSCLC. Patients were assigned by immunotherapy effects into response (partial and complete response, pCR) group (n=52) and non-response (non-pCR) group (n=132). The pathological and clinical data were collected for statistical analysis of factors influencing the immunotherapeutic response. The diagnostic value of PNI and CONUT score for response was assessed. The overall survival (OS) was observed over a 3-year follow-up. COX regression analysis was performed to identify risk factors affecting the survival. The effects of different PNI and CONUT scores on the survival were observed. RESULTS: Multivariate regression analysis showed that, the tumor-node-metastasis (TNM) stage (P=0.001), PNI (P<0.001), and CONUT score (P<0.001) were associated with response. The non-pCR group had a higher 3-year mortality rate and a shorter 3-year OS than the pCR group (P<0.001). COX regression analysis showed that low PNI and high CONUT score were risk factors for poor prognosis. Further analysis showed that patients with low PNI and high CONUT score had lower 3-year survival rates (P=0.005, P<0.001). CONCLUSION: High TNM stage, PNI<50, and CONUT score ≥5 are risk factors for poor response in patients with advanced NSCLC receiving PD-1 inhibitors, and low PNI and high CONUT score suggest poor prognosis.

Body Satisfaction, Exercise Dependence, and White Matter Microstructure in Young Adults.

BACKGROUND: Self-body satisfaction is considered a psychological factor for exercise dependence (EXD). However, the potential neuropsychological mechanisms underlying this association remain unclear. PURPOSE: To investigate the role of white matter microstructure in the association between body satisfaction and EXD. STUDY TYPE: Prospective. POPULATION: One hundred eight regular exercisers (age 22.11 ± 2.62 years; 58 female). FIELD STRENGTH/SEQUENCE: 3.0 Tesla; diffusion-weighted echo planar imaging with 30 directions. ASSESSMENT: The Body Shape Satisfaction (BSS) and Exercise Dependence Scale (EDS); whole-brain tract-based spatial statistics (TBSS) and correlational tractography analyses; average fractional anisotropy (FA) and quantitative anisotropy (QA) values of obtained tracts. STATISTICAL TESTS: The whole-brain regression model, mediation analysis, and simple slope analysis. P values <0.05 were defined as statistically significant. RESULTS: The BSS and EDS scores were 37.33 ± 6.32 and 68.22 ± 13.88, respectively. TBSS showed negative correlations between EDS and FA values in the bilateral corticospinal tract (CST, r = -0.41), right cingulum (r = -0.41), and left superior thalamic radiation (STR, r = -0.50). Correlational tractography showed negative associations between EDS and QA values of the left inferior frontal occipital fasciculus (r = -0.35), STR (r = -0.42), CST (r = -0.31), and right cingulum (r = -0.28). The FA values, rather than QA values, mediated the BSS-EDS association (indirect effects = 0.30). The BSS was significantly associated with the EDS score at both low (ß = 1.02) and high (ß = 0.43) levels of FA value, while the association was significant only at the high level of QA value (ß = 1.26). DATA CONCLUSION: EXD was correlated with white matter in frontal-subcortical and sensorimotor networks, and these tracts mediated the body satisfaction-EXD association. White matter microstructure could be a promising neural signature for understanding the underlying neuropsychological mechanisms of EXD. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 1.

Dynamic imaging of micro-vibrations with an ultra-wide bandwidth and a femtometer noise using switchable pulsed laser interferometry.

Imaging the complex dynamics of micro-vibrations plays a fundamental role in the investigation of microelectromechanical systems (MEMS). However, it remains a challenge for achieving both a wide bandwidth and a low noise due to the high photodetector noise and electromagnetic interference at GHz frequencies. Here, we propose a pulsed laser interferometry system with an adaptable switch to image GHz vibrations based on stroboscopic mixing, while measuring lower-frequency vibrations based on the homodyne scheme. The noise power spectral density is shown in both regions from DC to 10 GHz with an average noise down to 30.8 fm/√Hz at GHz frequencies, which holds the highest resolution to the best of our knowledge. Vibrational amplitude and phase mappings of a kHz comb-drive resonator, a GHz piezoelectric transducer, and a GHz film bulk acoustic resonator are presented with animated visualizations and k-space analysis, paving a new paradigm for the first time to image and analyze various MEMS devices of a bandwidth spanning 10 orders of magnitude.