Synthetic Technology Research Articles

Facet and dual vacancy engineering-boosting BiOBr for enhanced CO2 and epoxide cycloaddition reaction under mild and cocatalyst-free conditions: Double substrate active sites and activated surface bromine ions synergy

Among the many strategies for CO2 resource utilization, the synthetic technology of cyclic carbonates with 100 % atom economy through CO2and epoxide is one of the most industrially viable routes, but its efficiency has been severely hampered by the lack of highly active catalytic sites. Moreover, due to the intrinsic thermodynamic stability and kinetic inertia of CO2 and the higher energy barrier of the ring-opening reaction of epoxides, the heterogeneous catalytic conversion of CO2 highly depends on harsh operating conditions, high temperatures and pressures, and the incorporation of cocatalysts. The development of efficient heterogeneous catalysts for CO2 conversion under cocatalyst-free and mild conditions has always been a challenge. Herein, we have proposed a synergetic strategy of facet and vacancy engineering for the construction of highly efficient heterogeneous catalyst BiO1-xBr1-y-(010) for CO2 cycloaddition, where introducing the OVs-BrVs pairs into typical (010) facets BiOBr with simultaneous surface Lewis acid sites Bi3+ and nucleophilic sites Br−. By combining theoretical calculations and a series of systematic experiments, such as CO2 temperature-programmed desorption, electron paramagnetic resonance and fluorescence probe analysis experiments, the introduced OVs-BrVs pair can not only form Bi3+-Bi(3-x)+ dual active sites on the surface, which activate PO and CO2 respectively to reduce the energy barrier of CO2 insertion, but also activate Br− near BrVs to enhance their nucleophilic attacking ability and reduce the energy barrier of epoxides ring-opening. As a result, the BiO1-xBr1-y-(010) with abundant surface OVs-BrVs pairs showed a high cyclic carbonates conversion of 99 % with 100 % selectivity under cocatalyst-free and mild conditions, far surpassing most heterogeneous catalytic systems. This work provides a completely new strategy to construct high-performance heterogeneous CO2 cycloaddition catalysts through a simple facet and vacancy engineering strategy to overcome the harsh operating conditions limitation and the use of cocatalysts.

Recent Advancement in Porous Graphene from Synthesis to Properties: Critical Review on Functionalization Chemistry and Applications

AbstractGraphene is the main allotropy of carbon which exhibits properties like super conductivity, high electron transfer, and large surface area. Porous graphene (PG) has unique porous structure and many exposed edges. In 2D graphene pore ranges from several angstroms to nanometers. Similar to 3D graphene, which also has a porous structure, there are four different types: foam, sponge, and graphene hydrogel (GH). Graphene oxide (GO) and reduced graphene oxide (rGO) are used to create PG. This review focuses on various methods of synthesis of PG along with its inherent properties and methods to modify its properties by surface functionalization. Emphasis is also given on the discussion of various techniques that are involved in the PG characterization. This article discusses the formation of hybrids, and composites using PG. Applications and limitations of PG have also been indicated. This review shows an extensive overview of the main principles and the recent synthetic technologies about fabricating various innovative 3D graphene‐based materials. Subsequently, recent progresses in electrochemical energy devices and hydrogen energy generation/storage are explicitly covered. The applications of PG and its composites in the fields such as energy storage, solar units, sensors, supercapacitors, etc. have been discussed The up to date progress for pollutants detection and environmental remediation are also reviewed. Finally, challenges and outlooks in materials development for different applications are suggested.

Green Synthesis of Biorelevant Scaffolds through Organocatalytic/ Enzymatic Dynamic Kinetic Resolution.

This review highlights major developments in the application of green organocatalytic and enzymatic dynamic kinetic resolutions (DKRs) in the total synthesis of biorelevant scaffolds. It illustrates the diversity of useful bioactive products and intermediates that can be synthesized under greener and more economic conditions through the combination of the powerful concept of DKR, which allows the resolution of racemic compounds with up to 100% yield, with either asymmetric organocatalysis or enzymatic catalysis, avoiding the use of toxic and expensive metals. With the need for more ecologic synthetic technologies, this field will undoubtedly expand its scope in the future with the employment of other organocatalysts/enzymes to even more types of transformations, thus allowing powerful greener and more economic strategies to reach other biologically important molecules.

True Research on Super Artificial Intelligence Computer Based Satellite Deep Tech Artificial Telepathic, Neurotechnology or Mind Controller and Wireless Direct Energy Weapon, Psychotronic Cyber Crime Technologies

Wireless Remote Neural Monitoring: Bridging the Gap between Brain and Technology In the field of Neuroscience and technological advancements, the concept of Deep Tech Satellite Wireless Neural Monitoring technology has emerged as a ground breaking innovation. Which has been developed to read and understand the human brain and interact with it, which is also a wireless Direct Energy weapon. These Satellite Surveillance Criminal Operators are using this Wireless Psychotronic Neuro technology on a large scale against citizens.. Cyber criminals have started taking the help of technologies like Deep tech, satellite wireless Artificial Telepathy technology and wireless Neuro technology Bio Electro Magnetic Weapon. This is illegal deep tech satellite Neuro technology Or Mind controller technology and synthetic telepathic technology which is a psychotronic weapon and Hypnotic technology. These are deep tech satellite technologies that are used to harm and control citizens from a distance. Microwave hearing, also known as Voice to Skull [V2K]. This is Brain manipulation and Silent weapon satellite technology. This Satellite Super Artificial Intelligence [AI] Computer Or Super Computer is a Big Engineering. It is also a satellite surveillance Direct Energy weapon [Non-Contact Weapon]and Radiation weapon with which these Satellite Surveillance criminal operators carry out Physical and Cyber-attacks on citizens. Satellite Surveillance criminal operators and Cyber criminals do business worth several trillion dollars through this illegal satellite deep tech technology. This true research has been done to protect citizens from illegal deep tech satellite surveillance technology and Cyber terrorism.

Reflections on the safety regulation of commercialization of synthetic biology products

With the rapid development of synthetic biology, lots of synthetic biology technology achievements in various application fields have been commercialized, generating broad market prospects. The commercialization of products employing synthetic biology technology (hereinafter referred as synthetic biology products) has brought benefits to human beings, but it has also produced potential safety risks. At present, relevant laws and standards for regulation of biotechnology or genetically modified organisms have been adopted to regulate the safety risks of commercialization of synthetic biology products (CSBP). However, due to the complexity and uncertainty of synthetic biology, the safety risks of CSBP cannot be comprehensively regulated by these laws and standards. Therefore, it is of great significance to formulate specific supervision and management measures for regulating the safety risks of CSBP. This paper summarized the situation of CSBP in the fields of food, medical care, agriculture, environment, energy and materials, analyzed the safety risks existing in the CSBP, and sorted out current supervision situation of its safety risks in European countries, United States, as well as in China. We further proposed suggestions on the safety supervision and management measures on the safety risks of CSBP, including classified examination and approval, classified identification of products, and strict screening and approval of market entities before entering the market, and strengthening safety supervision and emergency treatment as well as accident responsibility investigation after entering the market. This whole-process safety regulation might provide support for the safety of CSBP and promote the healthy and long-term development of synthetic biology industry.

Recent Developments and Future Perspectives of Molybdenum Borides and MBenes.

Metal borides have received a lot of attention recently as a potentially useful material for a wide range of applications. In particular, molybdenum-based borides and MBenes are of great significance, due to their remarkable properties like good electronic conductivity, considerable stability, high surface area, and environmental harmlessness. Therefore, in this article, the progress made in molybdenum-based borides and MBenes in recent years is reviewed. The first step in understanding these materials is to begin with an overview of their structural and electronic properties. Then synthetic technologies for the production of molybdenum borides, such as high-temperature/pressure methods, physical vapor deposition (PVD), chemical vapor deposition (CVD), element reaction route, molten salt-assisted, and selective etching methods are surveyed. Then, the critical performance of these materials in numerous applications like energy storage, catalysis, biosensors, biomedical devices, surface-enhanced Raman spectroscopy (SERS), and tribology and lubrication are summarized. The review concludes with an analysis of the current progress of these materials and provides perspectives for future research. Overall, this review will offer an insightful reference for the understanding molybdenum-based borides and their development in the future.

Abstract 6660: The novel codon-modified Zika virus CDX-602 shows anti-tumor efficacy and remodels the tumor microenvironment in preclinical models

Abstract Multiple oncolytic viruses have been shown to induce multifaceted changes in the tumor microenvironment, that ultimately support induction of anti-tumor immune responses. We have previously demonstrated that CodaLytic, a codon-modified influenza virus, can kickstart the cancer immunity cycle at various steps in several mouse models with differing baseline immune contextures. Here, we are describing the activity of a new codon-modified virotherapeutic derived from the same synthetic viral engineering platform [Coleman et al., Science 2008]. Zika virus strain MR766 was synthetically codon-modified at 664 positions in the envelop gene to yield CDX-602. Virus was originally passaged in Vero cells and working stocks were expanded in BSR-T7 cells for in vivo use after titration on MA104.1 cells. Efficacy after intratumoral injection of 107 PFU/dose CDX-602 alone or in combination with 200 μg/dose αPD-1 blockade (RMP1-14, i.p.) was determined in subcutaneous B16-F10 melanoma and orthotopic EMT6 breast cancer models (n = 10). Changes in the tumor immune infiltrate were characterized using flow cytometry 6 or 8 days after treatment initiation, respectively (n = 5). In the immunotherapy-resistant B16-F10 model, CDX-602 monotherapy led to highly reproducible tumor growth inhibition (TGI, 52%, p < 0.0001 vs vehicle control), resulting in modest, but significant prolongation of median survival (25%, p < 0.01). Anti-tumor efficacy correlated with increased tumor immune infiltration with CD4+ and CD8+ T cells (R2 = 0.68 and 0.67, respectively, p < 0.01). Importantly, frequencies of cross-presenting dendritic cells (cDC) were increased 3.8-fold (p < 0.0001) after virus treatment, while no compensatory influx of CD206+ macrophages was observed, suggesting immune contexture changes conducive to anti-tumor immune induction. Efficacy was confirmed in the EMT6 model, in which monotherapy TGI was 44% and thus on par with αPD-1 blockade (50%, both p < 0.0001 vs control). Combination viroimmunotherapy in this model further improved efficacy, leading to 71% TGI and a doubling in complete regressions to 40%. Inclusion of CDX-602 in the treatment regimen led to similar changes in immune infiltration, in particular recruitment of CD8+ T cells and cDCs (9.7-fold and 6.9-fold increase after combination, respectively). Additional ex vivo analyses to confirm induction of anti-tumor immune responses are ongoing. Taken together, this preclinical data establishes CDX-602 as a novel virotherapeutic candidate that engages multiple mechanisms of action that contribute to anti-tumor activity. CDX-602 is the second virotherapeutic candidate derived from Codagenix’s codon modification platform, further supporting the utility of this synthetic viral engineering technology for viroimmunotherapy of cancer and highlighting its potential across multiple viral species. Citation Format: Nusrat Jahan, Yiwen Zhao, Katarina Blagovic, Ying Wang, J Robert Coleman, Steffen Mueller, Johanna K. Kaufmann. The novel codon-modified Zika virus CDX-602 shows anti-tumor efficacy and remodels the tumor microenvironment in preclinical models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6660.

Machine learning-based models to predict the conversion of normal blood pressure to hypertension within 5-year follow-up.

Factors contributing to the development of hypertension exhibit significant variations across countries and regions. Our objective was to predict individuals at risk of developing hypertension within a 5-year period in a rural Middle Eastern area. This longitudinal study utilized data from the Fasa Adults Cohort Study (FACS). The study initially included 10,118 participants aged 35-70 years in rural districts of Fasa, Iran, with a follow-up of 3,000 participants after 5 years using random sampling. A total of 160 variables were included in the machine learning (ML) models, and feature scaling and one-hot encoding were employed for data processing. Ten supervised ML algorithms were utilized, namely logistic regression (LR), support vector machine (SVM), random forest (RF), Gaussian naive Bayes (GNB), linear discriminant analysis (LDA), k-nearest neighbors (KNN), gradient boosting machine (GBM), extreme gradient boosting (XGB), cat boost (CAT), and light gradient boosting machine (LGBM). Hyperparameter tuning was performed using various combinations of hyperparameters to identify the optimal model. Synthetic Minority Over-sampling Technology (SMOTE) was used to balance the training data, and feature selection was conducted using SHapley Additive exPlanations (SHAP). Out of 2,288 participants who met the criteria, 251 individuals (10.9%) were diagnosed with new hypertension. The LGBM model (determined to be the optimal model) with the top 30 features achieved an AUC of 0.67, an f1-score of 0.23, and an AUC-PR of 0.26. The top three predictors of hypertension were baseline systolic blood pressure (SBP), gender, and waist-to-hip ratio (WHR), with AUCs of 0.66, 0.58, and 0.63, respectively. Hematuria in urine tests and family history of hypertension ranked fourth and fifth. ML models have the potential to be valuable decision-making tools in evaluating the need for early lifestyle modification or medical intervention in individuals at risk of developing hypertension.

Personality perception in synthetic versus natural speech: The effects of voice quality and prosody

Synthetic speech technology, now approaching human-like naturalness due to advancements in deep learning, has turned to focusing on personality or persona design as a common practice in the industry. The present study aimed to identify speech characteristics affecting personality impressions in synthetic and natural speech. Thirty native Korean speakers participated in a personality rating experiment in which they evaluated natural Korean sentences and their synthetic counterparts in terms of the Big-Five personality model. Acoustic analyses were performed to examine voice quality and prosody, including Intonational Phrase (IP) boundary tones. The results revealed that scores of agreeableness, conscientiousness, and emotional stability increased overall when the voices contained greater aperiodicity in the harmonics (i.e., were likely breathier) and were weaker in energy. The results also demonstrated that different prosodic features affected personality perception in synthetic and natural speech; synthetic speech with a wider F0 range received higher scores on extroversion, openness, and emotional stability. In contrast, the effect of IP boundary tones was most frequently found for female natural speech, which contained a wider range of tones, including multitonals (e.g., LHL%). Our findings suggest that intonation is one of the key factors which can be adjusted to generate synthetic speech with various personalities.

From salt water to bioceramics: Mimic nature through pressure-controlled hydration and crystallization.

Modern synthetic technology generally invokes high temperatures to control the hydration level of ceramics, but even the state-of-the-art technology can still only control the overall hydration content. Magically, natural organisms can produce bioceramics with tailorable hydration profiles and crystallization traits solely from amorphous precursors under physiological conditions. To mimic the biomineralization tactic, here, we report pressure-controlled hydration and crystallization in fabricated ceramics, solely from the amorphous precursors of purely inorganic gels (PIGs) synthesized from biocompatible aqueous solutions with most common ions in organisms (Ca2+, Mg2+, CO32-, and PO43-). Transparent ceramic tablets are directly produced by compressing the PIGs under mild pressure, while the pressure regulates the hydration characteristics and the subsequent crystallization behaviors of the synthesized ceramics. Among the various hydration species, the moderately bound and ordered water appears to be a key in regulating the crystallization rate. This nature-inspired study offers deeper insights into the magic behind biomineralization.

Synthetic Aperture Ladar Motion Compensation Method Based on Symmetric Triangle Linear Frequency Modulation Continuous Wave Segmented Interference

Synthetic Aperture Ladar (SAL) is a sensor that combines laser detection technology with synthetic aperture technology to achieve ultra-high-resolution imaging. Due to its extremely short wavelength, SAL is more sensitive to motion errors. The micrometer-level motion will affect the target’s azimuth focus. This article proposes an SAL motion compensation method based on Symmetric Triangular Linear Frequency Modulation Continuous Wave (STLFMCW) segmented interference, utilizing the characteristics of a triangular wave, to solve the problem of target azimuth defocusing. This article first establishes an STLFMCW echo signal model based on the SAL system under the influence of motion errors. Secondly, the radial velocity gradient along the azimuth direction is extracted using the triangular-wave-positive and -negative frequency modulation signals segmented interference method. Then, for the initial phase wrapping problem, the frequency spectral cross-correlation method is used to accurately estimate the initial radial velocity error. The radial velocity gradient is integrated along the azimuth to obtain the platform motion trajectory. Finally, the compensation functions are constructed to complete the echo Range Cell Migration (RCM) correction and residual phase compensation, resulting in a focused SAL image. This article verifies the practical effect of this method in eliminating motion errors using only one-period STLFMCW signal through simulation and real experiments. The quantitative results show that compared with the traditional method, the proposed method reduces the azimuth Peak Sidelobe Ratio (PSLR) by 8dB and the Integrated Sidelobe Ratio (ISLR) by 9 dB. This method has significant improvements and is of great significance for high-resolution FMCW SAL imaging.

Green and sustainable approaches for the Friedel-Crafts reaction between aldehydes and indoles.

The synthesis of indoles and their derivatives, more specifically bis(indolyl)methanes (BIMs), has been an area of great interest in organic chemistry, since these compounds exhibit a range of interesting biological and pharmacological properties. BIMs are naturally found in cruciferous vegetables and have been shown to be effective antifungal, antibacterial, anti-inflammatory, and even anticancer agents. Traditionally, the synthesis of BIMs has been achieved upon the acidic condensation of an aldehyde with indole, utilizing a variety of protic or Lewis acids. However, due to the increased environmental awareness of our society, the focus has shifted towards the development of greener synthetic technologies, like photocatalysis, organocatalysis, the use of nanocatalysts, microwave irradiation, ball milling, continuous flow, and many more. Thus, in this review, we summarize the medicinal properties of BIMs and the developed BIM synthetic protocols, utilizing the reaction between aldehydes with indoles, while focusing on the more environmentally friendly methods developed over the years.

Screening State of Play: The Biosecurity Practices of Synthetic DNA Providers.

Synthetic DNA technology is rapidly emerging as a key driver of innovation in the fields of medicine, biotechnology, and more. But it also poses significant risk, particularly in lowering barriers to the production of dangerous pathogens and toxins. At present, oversight of this technology is voluntarily coordinated among synthetic DNA providers and stakeholders, and detailed understanding of security processes, infrastructures, and insights from these providers is imperative to understand how to best mitigate the inherent risks of this technology. In this study, we aimed to determine the trends, outliers, strengths, and gaps in current DNA provider security practices through a broad survey of the gene synthesis field. We interviewed synthetic DNA providers and stakeholders about their customer and sequence screening procedures. Respondents were divided into groups based on membership in the International Gene Synthesis Consortium, nationality, whether they were a new or established company, and whether they synthesize de novo DNA or not. We then performed meta-analysis and intergroup analysis to elucidate larger trends and points of variance. In total, we interviewed 18 companies. We found that synthetic DNA providers and stakeholders tend to operate under a "zero-trust model" for screenings and utilize common governmental and private resources to navigate international import/export policies. Major variabilities were identified in the sensitivity of screening, monitoring and evaluation practices, screening pipelines, and approaches to synthetic oligonucleotide screening. In addition, we identified a significant vulnerability of lacking awareness among providers of formal law enforcement reporting procedures. Collectively, we observed significant heterogeneity in security practice throughout the field, reflective of the current lack of codified oversight for DNA synthesis. The results presented in this study provide insight into the specifics, strengths, and shortcomings of current DNA provider security practices, and are important considerations for the biosecurity community in ongoing deliberations of if, when, and how to approach oversight of synthetic DNA technology.

Recent Advances in Preceramic Polysilazane Precursors in Additive Manufacturing

Si3N4/SiCN ceramics have been extensively explored for applications in the aerospace, mechanical engineering, and biomedical fields. Recently, there has been significant focus on the additive manufacturing (AM) of polymer-derived ceramic (PDC) technology for fabricating Si3N4/SiCN ceramics. The chemical structure and composition of the preceramic polymer precursors have a crucial influence on the performance of ceramic products. In this paper, recent advances in the use of polysilazane and polycarbosilazane precursors in AM are reviewed and an outlook for future development is presented. The findings of this study could spark inspiration and reflection regarding AM applications and synthetic technology. It is believed that the development of PDCs in ceramic fabrication will become more versatile and application-oriented and provide more freedom in the design of high-performance ceramics.

An affordable, programmable and interactive continuous flow Photoreactor setup for undergraduate organic synthetic teaching labs

Photochemistry and continuous flow chemistry are synthetic technology platforms that have witnessed an increasing uptake by chemical industries interested in complex organic molecule synthesis. Simultaneously, automation and data science are prominent targets in organic synthesis and in chemical industries for streamlined workflows, meaning hardware-software interaction between operators and devices is crucial. Since undergraduate teaching labs at public-funded research Universities typically (i) lack budget for commercial, user-friendly continuous flow reactors and (ii) do not teach synthetic chemists how to program or interact with reactors, there is a disparity between the skills undergraduates are equipped with and the skills that future industries need. We report a teaching lab project where undergraduates assemble, program and execute a continuous flow photoreactor to realize a multigram-scale photoredox catalyzed oxidation reaction. A palladium-free synthetic access to the starting material was described to further cut costs. Not only does this exercise introduce useful skills in reactor design, programming and wet chemistry (both photochemical and thermal, both batch and flow), it also accommodates both the typical budget and afternoon timeslot (2-3 h) of a teaching lab and can be followed by thin-layer chromatography/color changes without necessarily requiring access to NMR facilities.Graphical abstract

Artificial Neural Network (ANN) Method for the Integration of Solar and Wind Hybrid Energy Sources into Telecommunication Systems

In order to sustain monetary growth, the introduction of renewable energy into the electricity grid is crucial especially for many foreign African locations. Thus, in order to reap sustainable strength, these foreign locations may also outfit their airport electrical equipment with advanced synthetic intelligence technologies. For a distributive hybrid solar strength grid, the paper attempts to propose an actual-time energy management algorithm. It continues with the combining of photovoltaic and wind energy for network simulation. As a function of the number of wind aero-mills and photovoltaic solar panels, a multi-goal approach is proposed to optimize the spectral efficiency of the location and the energy performance. For the MATLAB software simulation, radio criteria for Cell Wireless Interoperability Medium Access (WiMAX) technologies are taken into account. The obtained effects are much mitigated however theoretically encouraging for the mixing of green energy integration into the modern telecommunication structures

Risk Assessment of Geological Landslide Hazards Using D-InSAR and Remote Sensing

Landslide geological disasters, occurring globally, often result in significant loss of life and extensive economic damage. In recent years, the severity of these disasters has increased, likely due to the frequent occurrence of extreme rainstorms associated with global warming. This escalating trend emphasizes the urgent need for a simple and efficient method to identify hidden dangers related to landslide geological disasters. Areas experiencing seasonal heavy rainfall are particularly susceptible to such disasters, posing a serious threat to the lives and property of local residents. In response to the challenging characteristics of landslide geological hazards, such as their strong concealment and the high vegetation coverage in the Liupan Mountain area of the Loess Plateau, this study focuses on the integrated remote sensing identification and research of hidden landslide dangers in Longde County. The methodology combines differential interferometric synthetic aperture radar technology (D-InSAR) and high-resolution optical remote sensing. Surface deformation information of Longde County was obtained by analyzing 85 Sentinel-1A data from 2019 to mid-2020 using Stacking-InSAR, in conjunction with high-resolution optical remote sensing image data from GF-2 in 2019. Furthermore, the study conducted integrated remote sensing identification and field verification of landslide hazards throughout the entire county. This involved interpreting the shape and deformation marks of landslide hazards, identifying the disaster-bearing bodies, and expertly interpreting the environmental factors contributing to the hazards. As a result, 47 suspected landslide hazards and 21 field investigation points were identified, with 16 hazards verified with an accuracy of 76.19%. This outcome directly confirms the applicability and accuracy of the integrated remote sensing identification technology in the study area. The research results presented in this paper provide an effective scientific and theoretical basis for the monitoring and treatment of landslide geological disasters in the future stages. They also play a pivotal role in the prevention of such disasters.

A novel method for vacuum synthesis and structural regulation of layered molybdenum disulfide

Molybdenum disulfide (MoS2) has received considerable attention due to its promising biomedical technologies, foldable displays and optoelectronic properties. In this work, the vacuum synthetic technology was employed to grow four-layer MoS2 from sulfur powder and molybdenum trioxide (MoO3), after holding in a threaded crucible for 30 min at 1273 K. One characteristic of this process is to increase the pressure of sulfur by using the threaded crucible. The composition and morphology of the products depend upon the synthetic temperature. The vacuum-prepared MoS2 was used as a precursor for mono- or few-layers materials by ultrasonic treatment in isopropanol solution (IPA). The structure, morphology, composition, band gap and photoluminescence (PL) of MoS2 with mono- and few-layers were investigated in detail. This work has a great impact on the tunable layers and bandgap of MoS2.

SAL vibration estimation and compensation based on triangular interferometric signals.

Synthetic aperture Ladar (SAL) is an extension of synthetic aperture technology in the optical frequency band. Owing to the short wavelength of lasers, the system has high-resolution, high-data-rate, and refined imaging capabilities, which has potential in high-resolution observation fields such as ground observation and space target observation. However, the short wavelength of lasers also makes SAL severely sensitive to vibrations even on the micron order which cause azimuth defocusing and range cell migration. To address this problem, we establish a de-chirp signal model under vibration environment, and propose a vibration error estimation and compensation method using triangular interferometric signals. According to the symmetrical characteristics of triangular frequency modulated continuous wave (T-FMCW) and the time-frequency information introduced by the azimuthal vibration phase, we use a two-stage interferometry method to estimate instantaneous frequency introduced by the vibration errors that cause range cell migration. For the scenarios without obvious range cell migration, we use a one-stage interferometry method to estimate the instantaneous frequency. Subsequently, we establish a vibration compensation filter using the estimated instantaneous frequency to compensate for the vibration errors. We use two experiments to verify the effectiveness and superiority of the proposed method. The results show that the proposed method effectively eliminates range cell migration and azimuthal phase errors introduced by vibration errors, producing SAL imaging results with higher resolution than the conventional spectral correlation method.

Long-read single-cell sequencing reveals expressions of hypermutation clusters of isoforms in human liver cancer cells

The protein diversity of mammalian cells is determined by arrays of isoforms from genes. Genetic mutation is essential in species evolution and cancer development. Accurate long-read transcriptome sequencing at single-cell level is required to decipher the spectrum of protein expressions in mammalian organisms. In this report, we developed a synthetic long-read single-cell sequencing technology based on LOOPSeq technique. We applied this technology to analyze 447 transcriptomes of hepatocellular carcinoma (HCC) and benign liver from an individual. Through Uniform Manifold Approximation and Projection analysis, we identified a panel of mutation mRNA isoforms highly specific to HCC cells. The evolution pathways that led to the hyper-mutation clusters in single human leukocyte antigen molecules were identified. Novel fusion transcripts were detected. The combination of gene expressions, fusion gene transcripts, and mutation gene expressions significantly improved the classification of liver cancer cells versus benign hepatocytes. In conclusion, LOOPSeq single-cell technology may hold promise to provide a new level of precision analysis on the mammalian transcriptome.