Publications by authors named "Kaimin Gao"

The interconversion between singlet and triplet spin states of photogenerated radical pairs is a genuine quantum process, which can be harnessed to coherently manipulate the recombination products through a magnetic field. This control is central to such diverse fields as molecular optoelectronics, quantum sensing, quantum biology and spin chemistry, but its effect is typically fairly weak in pure molecular systems. Here we introduce hybrid radical pairs constructed from semiconductor quantum dots and organic molecules.

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Observation and understanding of fine-structure splitting of bright excitons in lead halide perovskite quantum dots (QDs) are crucial to their emerging applications in quantum light sources and exciton coherence manipulation. Recent studies demonstrate that ensemble-level polarization-resolved transient absorption spectroscopy can reveal the quantum beats arising from the coherence between two fine-structure levels. Here we report the observation of an extra fine-structure quantum coherence hidden in previous studies by using cryo-magnetic quantum beat spectroscopy.

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Mitochondrial permeability transition (mPT)-mediated mitochondrial dysfunction plays a pivotal role in various human diseases. However, the intricate details of its mechanisms and the sequence of events remain elusive, primarily due to the interference caused by Bax/Bak-induced mitochondrial outer membrane permeabilization (MOMP). To address these, we have developed a methodology that utilizes nano-flow cytometry (nFCM) to quantitatively analyze the opening of mitochondrial permeability transition pore (mPTP), dissipation of mitochondrial membrane potential ( Ψ), release of cytochrome c (Cyt c), and other molecular alternations of isolated mitochondria in response to mPT induction at the single-mitochondrion level.

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Monitoring mitochondrial esterase activity is crucial not only for investigating mitochondrial metabolism but also for assessing the effectiveness of mitochondrial-targeting prodrugs. However, accurately detecting esterase activity within mitochondria poses challenges due to its ubiquitous presence in cells and the uncontrolled localization of fluorogenic probes. To overcome this hurdle and reveal variations among different mitochondria, we isolated mitochondria and preserved their activity and functionality in a buffered environment.

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Lead halide perovskite quantum dots (QDs) have recently emerged as a promising material platform for quantum information processing owing to their strong light-matter interaction and relatively long-lived optical and spin coherences. In particular, the coherence of the fine-structure bright excitons is sustainable up to room temperature and can be observed even at an ensemble level. Here modulation of the polarization of these excitons in CsPbI QDs and manipulation of their time-domain coherent dynamics using a longitudinal magnetic field are demonstrated.

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Optical gain of colloidal quantum dots (QDs) is often attained in the multiexciton regime, which strongly complicates their lasing applications as the gain lifetime is limited by nonradiative Auger recombination occurring typically on the picosecond time scale. In principle, low-threshold gain can be achieved if the gain-active emission has a sizable red shift compared to the absorption. But, this mechanism has been rarely observed in typical QDs featuring small Stokes shift due to their weak electron-phonon coupling.

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Background: Population screening of asymptomatic persons with Epstein-Barr virus (EBV) DNA or antibodies has improved the diagnosis of nasopharyngeal carcinoma and survival among affected persons. However, the positive predictive value of current screening strategies is unsatisfactory even in areas where nasopharyngeal carcinoma is endemic.

Methods: We designed a peptide library representing highly ranked B-cell epitopes of EBV coding sequences to identify novel serologic biomarkers for nasopharyngeal carcinoma.

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Protein aggregation is one of the greatest challenges in biopharmaceuticals as it could decrease therapeutic efficacy, induce immunogenicity, and reduce shelf life of protein drugs. However, there lacks high-throughput methods than can count and size protein aggregates in the nanometer size range, especially for those smaller than 100 nm. Employing a laboratory-built nano-flow cytometer (nFCM) that enables light scattering detection of single silica nanoparticles as small as 24 nm with sizing resolution and accuracy comparable to those of electron microscopy, here, we report a new benchmark to analyze single protein aggregates as small as 40 nm.

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A relatively new addition to the application portfolio of lead halide perovskites is to photosensitize molecular triplets for a variety of photochemical applications. Here we report visible-light-driven isomerization and cycloaddition of organic molecules sensitized by spectrally-tunable perovskite nanocrystals. We first demonstrate with stilbene as the substrate molecule that photoisomerization can proceed efficiently and rapidly by either directly grafting carboxylated stilbene onto nanocrystal surfaces or using triplet-acceptor ligands as the energy relay.

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Colloidal semiconductor nanoplatelets (NPLs) are chemical versions of well-studied quantum wells (QWs). For QWs, gating and carrier doping are standard tools to manipulate their optical, electric, or magnetic properties. It would be highly desirable to use pure chemical methods to dope extra charge carriers into free-standing colloidal NPLs to achieve a similar level of manipulation.

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A key process underlying the application of low-dimensional, quantum-confined semiconductors in energy conversion is charge transfer from these materials, which, however, has not been fully understood yet. Extensive studies of charge transfer from colloidal quantum dots reported rates increasing monotonically with driving forces, never displaying an inverted region predicted by the Marcus theory. The inverted region is likely bypassed by an Auger-like process whereby the excessive driving force is used to excite another Coulomb-coupled charge.

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Telomere length (TL) is a highly relevant biomarker for age-associated diseases and cancer, yet its clinical applications have been hindered by the inability of existing methods to rapidly measure the TL distribution and the percentage of chromosomes with critically short telomeres (CSTs, < 3 kb). Herein, we report the development of a high-throughput method to measure TL at the single-chromosome level. Metaphase chromosomes are isolated, hybridized with the Alexa Fluor 488-labeled telomeric peptide nucleic acid probe, and analyzed using a laboratory-built ultrasensitive nano-flow cytometer.

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Mitochondrial fusion is essential to maintain genomic stability and physiological functions of mitochondria. Since mitochondrial fusion and fission work in concert to regulate mitochondrial morphology and functions, it has been challenging to quantitatively measure the direct roles of mitochondrial fusion in apoptosis and cancer progression. Here, we report the development of a high-throughput in vitro method to quantify mitochondrial fusion through single mitochondria analysis by a laboratory-built nano-flow cytometer (nFCM).

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Current cancer immunotherapies including chimeric antigen receptor (CAR)-based therapies and checkpoint immune inhibitors have demonstrated significant clinical success, but always suffer from immunotoxicity and autoimmune disease. Recently, nanomaterial-based immunotherapies are developed to precisely control in vivo immune activation in tumor tissues for reducing immune-related adverse events. However, little consideration has been put on the spatial modulation of interactions between immune cells and cancer cells to optimize the efficacy of cancer immunotherapies.

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Stimuli-responsive nanotheranostic systems, integrated with diagnosis and treatment features, have recently emerged and attracted much interest. However, most of the research mainly focuses on the novelty of nanomaterials, and undervalues the significance of single-particle characterization which can provide detailed physical and biochemical information for performance evaluation and heterogeneity assessment. Due to the small particle size and low content of functional modules, high throughput and multiparameter analysis of individual stimuli-responsive nanoparticles still remains challenging.

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Article Synopsis
  • - The study aimed to create a snail monitoring system using Baidu Map to track both historical and current snail environments.
  • - It utilized Geographic Information System (GIS), electronic fence technology, and API to link monitoring data to a database, enabling real-time surveillance.
  • - The resulting system features three main components: a Snail Monitoring Environmental Database, a Dynamic Monitoring Platform, and an Electronic Map, accessible via computer and smartphone for easy monitoring.
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Article Synopsis
  • The study aimed to apply Geographic Information System (GIS) electronic fence techniques for effectively monitoring snails in their natural environments.
  • An electronic fence was created on an electronic map to link snail monitoring data, allowing users to input and access real-time information through computers and smartphones.
  • The results showed that this method enabled dynamic monitoring and visualization of snail environments, creating unique digital archives for better management.
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The classification of individual things marks the depth of one's recognition on the general character of things. The method for the classification of dermatosis reflects the developmental level of dermatology from one aspect. Since modern time, there appeared a condition of the coexistence of multiple knowledge of medical systems, including traditional Chinese, western, amalgamation of traditional Chinese and western, and integration of Chinese and western.

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Mitochondria play a pivotal role in determining the point-of-no-return of the apoptotic process. Therefore, anticancer drugs that directly target mitochondria hold great potential to evade resistance mechanisms that have developed toward conventional chemotherapeutics. In this study, we report the development of an in vitro strategy to quickly identify the therapeutic agents that induce apoptosis via directly affecting mitochondria.

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Objective: To construct a platform for Schistosoma japonicum infection real-time monitoring and early warning in marshlands along the Yangtze River.

Methods: The data of the status of Oncomelania hupensis snails, schistosomiasis endemic situation, marshland environment status, and other basic information were collected and analyzed comprehensively in marshlands along the Yangtze River in Jiangsu Province, and a schistosomiasis endemic situation electronic map was established. Through the GPS and 3G technology, the short messaging service (SMS) alerts were sent to the fishermen when they entered the areas of different schistosomiasis endemic levels in real-time.

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