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1.
Small ; : e2403775, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38949055

RESUMO

Despite the challenges associated with the synthesis of flexible metal-covalent organic frameworks (MCOFs), these offer the unique advantage of maximizing the atomic utilization efficiency. However, the construction of flexible MCOFs with flexible building units or linkages has rarely been reported. In this study, novel flexible MCOFs are constructed using flexible building blocks and copper clusters with hydrazone linkages. The heterometallic frameworks (Cu, Co) are prepared through the hydrazone linkage coordination method and evaluated as catalysts for the oxygen evolution reaction (OER). Owing to the spatial separation and functional cooperation of the heterometallic MCOF catalysts, the as-synthesized MCOFs exhibited outstanding catalytic activities with an overpotential of 268.8 mV at 10 mA cm-2 for the OER in 1 M KOH, which is superior to those of the reported covalent organic frameworks (COFs)-based OER catalysts. Theoretical calculations further elucidated the synergistic effect of heterometallic active sites within the linkages and frameworks, contributing to the enhanced OER activity. This study thus introduces a novel approach to the fundamental design of flexible MCOF catalysts for the OER, emphasizing their enhanced atomic utilization efficiency.

2.
Bioresour Technol ; 407: 131073, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38996848

RESUMO

Co-pyrolysis with low-sulfur biomass is expected to improve the yield and quality of bio-fuels, without the usage of calcium-based desulfurizer. Sulfur transformation during microwave fluidized-bed co-pyrolysis between terrestrial and marine biomass (Ascophyllum, AS; Rice straw, RS) was investigated. Sulfur release was promoted during biomass co-pyrolysis, but it was inhibited during pyrolysis between AS and low-sulfur char. Thermal cracking of biomass was promoted during co-pyrolysis between biomass, accelerating the combination of H atoms and -SH radicals. Introduction of low-sulfur bio-char (CA) inhibited the generation of bio-char and the release of sulfur. Released sulfur was captured by -OH/C = C functional groups on bio-char through dehydration reactions/addition reactions, forming mercaptan in bio-char. Furthermore, introduction of microwave and bio-char promoted the cyclization and aromatization reaction, converting mercaptan to thiophene and improving the thermal stability of solid sulfur, and thus increasing in-situ sulfur fixation rate.

3.
Sci Rep ; 14(1): 15989, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38987351

RESUMO

Thiophene is the organic sulfur with good thermal stability in carbon-based fuel, clarifying the conversion mechanism between thiophene and COS is beneficial for achieving in-situ sulfur fixation during CO2 gasification of carbon-based fuels, but the mechanism has rarely been reported. Therefore, calculations based on density functional theory were performed and 16 reaction paths were proposed in this research, clarifying the decomposition mechanism of thiophene and re-fixation mechanism of COS. The attachment of CO2 will lead to the destruction of the thiophene ring and the generation of COS, and CO2 adsorption is the rate-determined step, while the carbon atom that adjacent sulfur atom is the reaction active site. However, the energy barriers of CO2 addition reactions are lower than those of CO2 adsorption reactions, and the energy barrier of reactions occurring on the aliphatics are lower than that occurring on the aromatics. The combination of CO2 and thiophene will thermodynamically lead to the generation of COS and CO. Moreover, gaseous sulfur generated from thiophene decomposition will be converted mutually, while H2S will not be converted into COS. Furthermore, COS will be captured by char, forming solid organic sulfur. The re-fixation of COS will occur on aliphatic chains from the decomposition of aromatics.

4.
Res Sq ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-39011116

RESUMO

Neurogliaform cells are a distinct type of GABAergic cortical interneurons known for their 'volume transmission' output property. However, their activity and function within cortical circuits remain unclear. Here, we developed two genetic tools to target these neurons and examine their function in the primary visual cortex. We found that the spontaneous activity of neurogliaform cells positively correlated with locomotion. Silencing these neurons increased spontaneous activity during locomotion and impaired visual responses in L2/3 pyramidal neurons. Furthermore, the contrast-dependent visual response of neurogliaform cells varies with their laminar location and is constrained by their morphology and input connectivity. These findings demonstrate the importance of neurogliaform cells in regulating cortical behavioral state-dependent spontaneous activity and indicate that their functional engagement during visual stimuli is influenced by their laminar positioning and connectivity.

5.
Small ; : e2404192, 2024 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-39004849

RESUMO

The tunable pore walls and skeletons render covalent organic frameworks (COFs) as promising absorbents for gold (Au) ion. However, most of these COFs suffered from low surface areas hindering binding sites exposed and weak binding interaction resulting in sluggish kinetic performance. In this study, COFs have been constructed with synergistic linker and linkage for high-efficiency Au capture. The designed COFs (PYTA-PZDH-COF and PYTA-BPDH-COF) with pyrazine or bipyridine as linkers showed high surface areas of 1692 and 2076 m2 g‒1, providing high exposed surface areas for Au capture. In addition, the Lewis basic nitrogen atoms from the linkers and linkages are easily hydronium, which enabled to fast trap Au via coulomb force. The PYTA-PZDH-COF and PYTA-BPDH-COF showed maximum Au capture capacities of 2314 and 1810 mg g-1, higher than other reported COFs. More importantly, PYTA-PZDH-COF are capable of rapid adsorption kinetics with achieving 95% of maximum binding capacity in 10 min. The theoretical calculation revealed that the nitrogen atoms in linkers and linkages from both COFs are simultaneously hydronium, and then the protonated PYTA-PZDH-COF are more easily binding the AuCl4 ‒, further accelerating the binding process. This study gives the a new insight to design COFs for ion capture.

6.
PeerJ ; 12: e17706, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39006021

RESUMO

Objectives: To evaluate the efficacy of peri-trigger female reproductive hormones (FRHs) in the prediction of oocyte maturation in normal ovarian reserve patients during the in vitro fertilization-embryo transfer (IVF-ET) procedure. Materials and Methods: A hospital database was used to extract data on IVF-ET cases from January 2020 to September 2021. The levels of female reproductive hormones, including estradiol (E2), luteinizing hormone (LH), progesterone (P), and follicle-stimulating hormone (FSH), were initially evaluated at baseline, the day of the trigger, the day after the trigger, and the day of oocyte retrieval. The relative change in E2, LH, P, FSH between time point 1 (the day of trigger and baseline) and time point 2 (the day after the trigger and day on the trigger) was defined as E2_RoV1/2, LH_RoV1/2, P_RoV1/2, and FSH_RoV1/2, respectively. Univariable and multivariable regression were performed to screen the peri-trigger FRHs for the prediction of oocyte maturation. Results: A total of 118 patients were enrolled in our study. Univariable analysis revealed significant associations between E2_RoV1 and the rate of MII oocytes in the GnRH-agonist protocol group (p < 0.05), but not in the GnRH-antagonist protocol group. Conversely, P_RoV2 emerged as a potential predictor for the rate of MII oocytes in both protocol groups (p < 0.05). Multivariable analysis confirmed the significance of P_RoV2 in predicting oocyte maturation rate in both groups (p < 0.05), while the association of E2_RoV1 was not significant in either group. However, within the subgroup of high P_RoV2 in the GnRH-agonist protocol group, association was not observed to be significant. The C-index was 0.83 (95% CI [0.73-0.92]) for the GnRH-agonist protocol group and 0.77 (95% CI [0.63-0.90]) for the GnRH-antagonist protocol group. The ROC curve analysis further supported the satisfactory performance of the models, with area under the curve (AUC) values of 0.79 for the GnRH-agonist protocol group and 0.81 for the GnRH-antagonist protocol group. Conclusions: P_RoV2 showed significant predictive value for oocyte maturation in both GnRH-agonist and GnRH-antagonist protocol groups, which enhances the understanding of evaluating oocyte maturation and inform individualized treatment protocols in controlled ovarian hyperstimulation during IVF-ET for normal ovarian reserve patients.


Assuntos
Transferência Embrionária , Estradiol , Fertilização in vitro , Hormônio Foliculoestimulante , Hormônio Luteinizante , Reserva Ovariana , Indução da Ovulação , Progesterona , Humanos , Feminino , Adulto , Estudos Retrospectivos , Fertilização in vitro/métodos , Reserva Ovariana/efeitos dos fármacos , Reserva Ovariana/fisiologia , Estradiol/sangue , Hormônio Foliculoestimulante/sangue , Hormônio Luteinizante/sangue , Transferência Embrionária/métodos , Progesterona/sangue , Indução da Ovulação/métodos , Oócitos/efeitos dos fármacos , Oócitos/crescimento & desenvolvimento , Gravidez , Oogênese/efeitos dos fármacos , Oogênese/fisiologia , Recuperação de Oócitos/métodos
7.
Artigo em Inglês | MEDLINE | ID: mdl-38980948

RESUMO

Fine tuning of the metal site coordination environment of a single-atom catalyst (SAC) to boost its catalytic activity for oxygen reduction reaction (ORR) is of significance but challenging. Herein, we report a new SAC bearing Fe-N3C-N sites with asymmetric in-plane coordinated Fe-N3C and axial coordinated N atom for ORR, which was obtained by pyrolysis of an iron isoporphyrin on polyvinylimidazole (PVI) coated carbon black. The C@PVI-(NCTPP)Fe-800 catalyst exhibited significantly improved ORR activity (E1/2 = 0.89 V vs RHE) than the counterpart SAC with Fe-N4-N sites in 0.1 M KOH. Significantly, the Zn-air batteries equipped with the C@PVI-(NCTPP)Fe-800 catalyst demonstrated an open-circuit voltage (OCV) of 1.45 V and a peak power density (Pmax) of 130 mW/cm2, outperforming the commercial Pt/C catalyst (OCV = 1.42 V; Pmax = 119 mW/cm2). The density functional theory (DFT) calculations revealed that the d-band center of the asymmetric Fe-N3C-N structure shifted upward, which enhances its electron-donating ability, favors O2 adsorption, and supports O-O bond activation, thus leading to significantly promoted catalytic activity. This research presents an intriguing strategy for the designing of the active site architecture in metal SACs with a structure-function controlled approach, significantly enhancing their catalytic efficiency for the ORR and offering promising prospects in energy-conversion technologies.

8.
Anal Chem ; 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39017607

RESUMO

A portable Hadamard-transform Raman spectrometer with excellent performance was fabricated consisting of a 785 nm laser, an optical filter, an optical system, a control system, and a signal processing system. As the core of the spectrometer, the optical system was composed of a slit, collimator, optical grating, reflector, digital micromirror devices (DMD), lens system, and InGaAs photodetector. Compared with a conventional dispersive Raman spectrometer, the proposed Raman spectrometer adopted the DMD and corresponding controlling device (DLPC350 control chip) to collect the Raman spectrum. Thus, in our design, the gratings are fixed, while the full Raman spectrum was collected by the deflection of the micromirror. This design can greatly improve the vibration resistance ability of the spectrometer since the gratings are not rotating during the spectrum collecting. More importantly, Hadamard-transform was used as signal processing technology, which has the ability of faster calculation, the merits of high energy input, single detector multichannel simultaneous detection (imaging) ability, and high signal-to-noise ratio (SNR). Hence, the Hadamard-transform portable Raman spectrometer has the potential to be applied in the field of point-of-care testing (POCT).

9.
Neoplasma ; 71(3): 243-254, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38958714

RESUMO

Allicin (AL) is one of garlic-derived organosulfides and has a variety of pharmacological effects. Studies have reported that AL has notable inhibitory effects on liver cancer, gastric cancer, breast cancer, and other cancers. However, there are no relevant reports about its role in human nasopharyngeal carcinoma. Ferroptosis is an iron-dependent form of non-apoptotic regulated cell death. Increasing evidence indicates that induction of ferroptosis can inhibit the proliferation, migration, invasion, and survival of various cancer cells, which act as a tumor suppressor in cancer. In this study, we confirmed that AL can inhibit cell proliferation, migration, invasion, and survival in human nasopharyngeal carcinoma cells. Our finding shows that AL can induce the ferroptosis axis by decreasing the level of GSH and GPX4 and promoting the induction of toxic LPO and ROS. AL-mediated cytotoxicity in human nasopharyngeal carcinoma cells is dependent on ferroptosis. Therefore, AL has good anti-cancer properties and is expected to be a potential drug for the treatment of nasopharyngeal carcinoma.


Assuntos
Proliferação de Células , Dissulfetos , Ferroptose , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas , Espécies Reativas de Oxigênio , Ácidos Sulfínicos , Humanos , Ferroptose/efeitos dos fármacos , Dissulfetos/farmacologia , Carcinoma Nasofaríngeo/tratamento farmacológico , Carcinoma Nasofaríngeo/patologia , Proliferação de Células/efeitos dos fármacos , Ácidos Sulfínicos/farmacologia , Neoplasias Nasofaríngeas/tratamento farmacológico , Neoplasias Nasofaríngeas/patologia , Linhagem Celular Tumoral , Espécies Reativas de Oxigênio/metabolismo , Movimento Celular/efeitos dos fármacos , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Glutationa/metabolismo , Sobrevivência Celular/efeitos dos fármacos
10.
Clin Cancer Res ; 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39037364

RESUMO

Advances in anticancer therapies have provided crucial benefits for millions of patients who are living long and fulfilling lives. While these successes should be celebrated, there is certainly room to continue improving cancer care. Increased long-term survival presents additional challenges for determining whether new therapies further extend patients' lives through clinical trials, commonly known as the gold standard endpoint of overall survival (OS). As a result, there is an increasing reliance on earlier efficacy endpoints , which may or may not correlate with OS, to continue the timely pace of translating innovation into novel therapies available for patients. Even when not powered as an efficacy endpoint, OS remains a critical indication of safety for regulatory decisions and is a key aspect of the U.S. Food and Drug Administration's Project Endpoint. Unfortunately, in the pursuit of earlier endpoints, many registrational clinical trials lack adequate planning, collection, and analysis of OS data, which complicates interpretation of a net clinical benefit or harm. This article shares best practices, proposes novel statistical methodologies, and provides detailed recommendations to improve the rigor of using OS data to inform benefit-risk assessments, including incorporating the following in clinical trials intending to demonstrate the safety and effectiveness of a cancer therapy: prospective collection of OS data, establishment of fit-for-purpose definitions of OS detriment, and prespecification of analysis plans for using OS data to evaluate for potential harm. These improvements hold promise to help regulators, patients and providers better understand the benefits and risks of novel therapies.

12.
Sci Total Environ ; 942: 173567, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-38848918

RESUMO

The increasing trend of using agricultural wastes follows the concept of "waste to wealth" and is closely related to the themes of sustainable development goals (SDGs). Carbon-neutral technologies for waste management have not been critically reviewed yet. This paper reviews the technological trend of agricultural waste utilization, including composting, thermal conversion, and anaerobic digestion. Specifically, the effects of exogenous additives on the contents, fractionation, and fate of phosphorus (P) and potentially toxic elements (PTEs) during the composting process have been comprehensively reviewed in this article. The composting process can transform biomass-P and additive-born P into plant available forms. PTEs can be passivated during the composting process. Biochar can accelerate the passivation of PTEs in the composting process through different physiochemical interactions such as surface adsorption, precipitation, and cation exchange reactions. The addition of exogenous calcium, magnesium and phosphate in the compost can reduce the mobility of PTEs such as copper, cadmium, and zinc. Based on critical analysis, this paper recommends an eco-innovative perspective for the improvement and practical application of composting technology for the utilization of agricultural biowastes to meet the circular economy approach and achieve the SDGs.


Assuntos
Agricultura , Compostagem , Fósforo , Fósforo/análise , Agricultura/métodos , Compostagem/métodos , Gerenciamento de Resíduos/métodos
13.
Small ; : e2403655, 2024 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-38881262

RESUMO

Developing advanced functional carbon materials is essential for electrocatalysis, caused by their vast merits for boosting many key energy conversion reactions. Herein, the covalent organic frameworks (COFs) is utilized on metal-organic frameworks (MOFs) as the template, under the controllable metal atoms thermal migration process successfully in situ constructs Pd-Co alloy nanoparticles on hollow cubic graphene. The electrocatalytic oxygen reduction reaction (ORR) evaluation showed excellent performances with a half-wave potential of 0.866 V, and a limited current density of 4.975 mA cm-2, that superior to the commercial Pt/C and Co nanoparticles. The contrast experiments and X-ray absorption spectrum demonstrated the aggregated electrons at highly dispersed Pd atoms on Co nanoparticle that promoted the main activities. This work not only enlightens the novel carbon materials designing strategies but also suggests heterogeneous electrocatalysis.

14.
J Transl Med ; 22(1): 577, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890669

RESUMO

BACKGROUND: Inherited variations in DNA double-strand break (DSB) repair pathway are known to influence ovarian cancer occurrence, progression and treatment response. Despite its significance, survival-associated genetic variants within the DSB pathway remain underexplored. METHODS: In the present study, we performed a two-phase analysis of 19,290 single-nucleotide polymorphisms (SNPs) in 199 genes in the DSB repair pathway from a genome-wide association study (GWAS) dataset and explored their associations with overall survival (OS) in 1039 Han Chinese epithelial ovarian carcinoma (EOC) patients. After utilizing multivariate Cox regression analysis with bayesian false-discovery probability for multiple test correction, significant genetic variations were identified and subsequently underwent functional prediction and validation. RESULTS: We discovered a significant association between poor overall survival and the functional variant GEN1 rs56070363 C > T (CT + TT vs. TT, adjusted hazard ratio (HR) = 2.50, P < 0.001). And the impact of GEN1 rs56070363 C > T on survival was attributed to its reduced binding affinity to hsa-miR-1287-5p and the resultant upregulation of GEN1 mRNA expression. Overexpression of GEN1 aggregated EOC cell proliferation, invasion and migration presumably by influencing the expression of immune inhibitory factors, thereby elevating the proportion of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) and then constructing an immunosuppressive tumor microenvironment. CONCLUSIONS: In conclusion, GEN1 rs56070363 variant could serve as a potential predictive biomarker and chemotherapeutic target for improving the survival of EOC patients.


Assuntos
Carcinoma Epitelial do Ovário , Resolvases de Junção Holliday , Neoplasias Ovarianas , Polimorfismo de Nucleotídeo Único , Feminino , Humanos , Pessoa de Meia-Idade , Carcinoma Epitelial do Ovário/genética , Carcinoma Epitelial do Ovário/mortalidade , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , China , População do Leste Asiático/genética , Regulação Neoplásica da Expressão Gênica , Estudo de Associação Genômica Ampla , Estimativa de Kaplan-Meier , MicroRNAs/genética , Invasividade Neoplásica , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/mortalidade , Prognóstico , Análise de Sobrevida , Resolvases de Junção Holliday/genética
15.
Nat Commun ; 15(1): 5421, 2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38926335

RESUMO

During brain development, neural circuits undergo major activity-dependent restructuring. Circuit wiring mainly occurs through synaptic strengthening following the Hebbian "fire together, wire together" precept. However, select connections, essential for circuit development, are transient. They are effectively connected early in development, but strongly diminish during maturation. The mechanisms by which transient connectivity recedes are unknown. To investigate this process, we characterize transient thalamocortical inputs, which depress onto somatostatin inhibitory interneurons during development, by employing optogenetics, chemogenetics, transcriptomics and CRISPR-based strategies in mice. We demonstrate that in contrast to typical activity-dependent mechanisms, transient thalamocortical connectivity onto somatostatin interneurons is non-canonical and involves metabotropic signaling. Specifically, metabotropic-mediated transcription, of guidance molecules in particular, supports the elimination of this connectivity. Remarkably, we found that this process impacts the development of normal exploratory behaviors of adult mice.


Assuntos
Interneurônios , Somatostatina , Tálamo , Animais , Interneurônios/metabolismo , Somatostatina/metabolismo , Somatostatina/genética , Camundongos , Tálamo/metabolismo , Optogenética , Transdução de Sinais , Masculino , Córtex Cerebral/metabolismo , Córtex Cerebral/citologia , Córtex Cerebral/crescimento & desenvolvimento , Feminino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos
16.
Artigo em Inglês | MEDLINE | ID: mdl-38875092

RESUMO

Deep neural networks (DNNs) have been widely used in many artificial intelligence (AI) tasks. However, deploying them brings significant challenges due to the huge cost of memory, energy, and computation. To address these challenges, researchers have developed various model compression techniques such as model quantization and model pruning. Recently, there has been a surge in research on compression methods to achieve model efficiency while retaining performance. Furthermore, more and more works focus on customizing the DNN hardware accelerators to better leverage the model compression techniques. In addition to efficiency, preserving security and privacy is critical for deploying DNNs. However, the vast and diverse body of related works can be overwhelming. This inspires us to conduct a comprehensive survey on recent research toward the goal of high-performance, cost-efficient, and safe deployment of DNNs. Our survey first covers the mainstream model compression techniques, such as model quantization, model pruning, knowledge distillation, and optimizations of nonlinear operations. We then introduce recent advances in designing hardware accelerators that can adapt to efficient model compression approaches. In addition, we discuss how homomorphic encryption can be integrated to secure DNN deployment. Finally, we discuss several issues, such as hardware evaluation, generalization, and integration of various compression approaches. Overall, we aim to provide a big picture of efficient DNNs from algorithm to hardware accelerators and security perspectives.

17.
Biomed Pharmacother ; 176: 116937, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38870632

RESUMO

The advent of general anesthesia (GA) has significant implications for clinical practice. However, the exact mechanisms underlying GA-induced transitions in consciousness remain elusive. Given some similarities between GA and sleep, the sleep-arousal neural nuclei and circuits involved in sleep-arousal, including the 5-HTergic system, could be implicated in GA. Herein, we utilized pharmacology, optogenetics, chemogenetics, fiber photometry, and retrograde tracing to demonstrate that both endogenous and exogenous activation of the 5-HTergic neural circuit between the dorsal raphe nucleus (DR) and basolateral amygdala (BLA) promotes arousal and facilitates recovery of consciousness from sevoflurane anesthesia. Notably, the 5-HT1A receptor within this pathway holds a pivotal role. Our findings will be conducive to substantially expanding our comprehension of the neural circuit mechanisms underlying sevoflurane anesthesia and provide a potential target for modulating consciousness, ultimately leading to a reduction in anesthetic dose requirements and side effects.


Assuntos
Anestésicos Inalatórios , Complexo Nuclear Basolateral da Amígdala , Estado de Consciência , Núcleo Dorsal da Rafe , Sevoflurano , Sevoflurano/farmacologia , Animais , Núcleo Dorsal da Rafe/efeitos dos fármacos , Núcleo Dorsal da Rafe/metabolismo , Estado de Consciência/efeitos dos fármacos , Anestésicos Inalatórios/farmacologia , Complexo Nuclear Basolateral da Amígdala/efeitos dos fármacos , Complexo Nuclear Basolateral da Amígdala/metabolismo , Complexo Nuclear Basolateral da Amígdala/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Serotonina/metabolismo , Vias Neurais/efeitos dos fármacos , Vias Neurais/fisiologia , Receptor 5-HT1A de Serotonina/metabolismo , Optogenética
18.
Anal Chim Acta ; 1312: 342751, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38834265

RESUMO

BACKGROUND: The abuse of the Phencyclidine-type substances, especially ketamine is a serious problem worldwide, and retrospective analysis are important for both the analysis and the identification of forms of drug abuse. The current major analytical methods, while all excellent in terms of accuracy, are time- and reagent-consuming. This depletion is made even more unfortunate by the fact that a large number of samples are negative in retrospective analyses. It is clear that a set of methods that can be analyzed both accurately and quickly need to be developed and applied to the screening and analysis of large quantities of samples. RESULTS: We described a urine test based on acoustic ejection mass spectrometry, which allows precise injection at very low volumes and near 1 ejection s-1 and data acquisition. The confidence in identification was increased by the characterization of the abundance ratio of the two pairs of ions. Urine samples could be diluted with water and loaded into a 384-well plate for sampling without complicated sample preparation. The sample in the transparent 384-well plate was pre-scanned by the laser, and then 20 nL droplets were ejected into the ion source for targeted analysis of 2 ion transitions per droplet totaling 9 targeted analytes in the sequence of acquisition methods. It took 90 min to screen 250 samples in this approach, yielding 10 ng mL-1 detection limits. Positive samples were further analyzed by UHPLC-MS/MS for confirmation and quantification of up to 36 analytes. SIGNIFICANCE: This was the first fast screening method for phencyclidine-type substances based on acoustic ejection mass spectrometry, which greatly reduces the analytical time, and can accomplish in 1.5 h what UHPLC-MS/MS needs 3 days to complete. And the samples can be analyzed without complicated sample preparation, and also can obtain good detectability. It was applied to a short-term retrospective analysis in Shanghai, and its accuracy was also extremely high.


Assuntos
Ensaios de Triagem em Larga Escala , Fenciclidina , Espectrometria de Massas em Tandem , Espectrometria de Massas em Tandem/métodos , Fenciclidina/urina , Humanos , Detecção do Abuso de Substâncias/métodos , Acústica
19.
bioRxiv ; 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38895403

RESUMO

Neurogliaform cells are a distinct type of GABAergic cortical interneurons known for their "volume transmission" output property. However, their activity and function within cortical circuits remain unclear. Here, we developed two genetic tools to target these neurons and examine their function in the primary visual cortex. We found that the spontaneous activity of neurogliaform cells positively correlated with locomotion. Silencing these neurons increased spontaneous activity during locomotion and impaired visual responses in L2/3 pyramidal neurons. Furthermore, the contrast-dependent visual response of neurogliaform cells varies with their laminar location and is constrained by their morphology and input connectivity. These findings demonstrate the importance of neurogliaform cells in regulating cortical behavioral state-dependent spontaneous activity and indicate that their functional engagement during visual stimuli is influenced by their laminar positioning and connectivity.

20.
Neuroimage ; 296: 120680, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38857819

RESUMO

Magnetic Resonance Imaging (MRI) can provide the location and signal characteristics of pathological regions within a postmortem tissue block, thereby improving the efficiency of histopathological studies. However, such postmortem-MRI guided histopathological studies have so far only been performed on fixed samples as imaging tissue frozen at the time of extraction, while preserving its integrity, is significantly more challenging. Here we describe the development of cold-postmortem-MRI, which can preserve tissue integrity and help target techniques such as transcriptomics. As a first step, RNA integrity number (RIN) was used to determine the rate of tissue biomolecular degradation in mouse brains placed at various temperatures between -20 °C and +20 °C for up to 24 h. Then, human tissue frozen at the time of autopsy was immersed in 2-methylbutane, sealed in a bio-safe tissue chamber, and cooled in the MRI using a recirculating chiller to determine MRI signal characteristics. The optimal imaging temperature, which did not show significant RIN deterioration for over 12 h, at the same time giving robust MRI signal and contrast between brain tissue types was deemed to be -7 °C. Finally, MRI was performed on human tissue blocks at this optimal imaging temperatures using a magnetization-prepared rapid gradient echo (MPRAGE, isotropic resolution between 0.3-0.4 mm) revealing good gray-white matter contrast and revealing subpial, subcortical, and deep white matter lesions. RINs measured before and after imaging revealed no significant changes (n = 3, p = 0.18, paired t-test). In addition to improving efficiency of downstream processes, imaging tissue at sub-zero temperatures may also improve our understanding of compartment specificity of MRI signal.


Assuntos
Autopsia , Encéfalo , Imageamento por Ressonância Magnética , Humanos , Imageamento por Ressonância Magnética/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Camundongos , Autopsia/métodos , Animais , Congelamento , Masculino , Feminino , Camundongos Endogâmicos C57BL , Neuroimagem/métodos
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