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1.
Org Lett ; 26(41): 8848-8853, 2024 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-39377579

RESUMO

A N-heterocyclic carbene-catalyzed (NHC) three-component reaction involving N-aminopyridinium salts, alkenes, and aldehydes for the synthesis of ß-amino ketones is described. In this reaction, N-aminopyridinium salts and the Breslow intermediate, which is generated from NHC and aldehydes, are utilized to undergo a single-electron transfer process, forming a ketyl radical intermediate and amidyl radicals. Subsequent to the formation of the amidyl radical, it undergoes selective capture by alkenes, followed by radical cross-coupling to yield the desired ß-amino ketones.

2.
Org Lett ; 26(40): 8572-8576, 2024 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-39330937

RESUMO

Herein, aryl decarboxylative allylation, thiolation, and bromination reactions via photoinduced ligand-to-copper charge transfer are described. Utilizing inexpensive copper metal, the transformations of various aryl carboxylic acids enable the rapid synthesis of the corresponding alkene, thioether, and aryl bromide derivatives under visible light irradiation, which offers significant synthetic value. The reaction conditions are mild and straightforward, exhibiting a broad substrate compatibility. Furthermore, this method can be applied for the late-stage modification of complex drug molecules.

3.
ACS Appl Mater Interfaces ; 16(37): 49733-49744, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39231365

RESUMO

This paper presents a comprehensive study of the structural optimization of polyimide-film (PI-film) capacitive humidity sensors, with a focus on enhancing their performance for application in new energy vehicles (NEVs). Given the critical role of humidity sensors in ensuring the safety and efficiency of vehicle operations─particularly in monitoring lithium-ion battery systems─the study explores the intricate relationship between the interdigitated electrode (IDE) dimensions and the PI-film thickness to optimize sensor responsiveness and reliability. Through a combination of COMSOL Multiphysics simulations (a powerful finite element analysis, solver, and simulation software) and experimental validation, the research identifies the optimal geometrical combination that maximizes the sensitivity and minimizes the response time. The fabrication process is streamlined for batch preparation, leveraging the spin-coating process to achieve consistent and reliable PI films. Extensive characterizations confirm the superior morphology, chemical composition, and humidity-sensing capabilities of the developed sensors. Practical performance tests further validate their exceptional repeatability, long-term stability, low hysteresis, and excellent selectivity, underpinning their suitability for automotive applications. The final explanation of the sensing mechanism provides a solid theoretical foundation for observed performance improvements. This work not only advances the field of humidity sensing for vehicle safety but also offers a robust theoretical and practical framework for the batch preparation of PI-film humidity sensors, promising enhanced safety and reliability for NEVs.

4.
Talanta ; 278: 126487, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39002258

RESUMO

Early screening for pathogens is crucial during pandemic outbreaks. Nucleic acid testing (NAT) is a valuable method for keeping pathogens from spreading. However, the long detection time and large size of the instruments involved significantly limited the efficiency of detection. This work described an integrated NAT microsensor that facilitated rapid and extremely sensitive detection based on nucleic acid amplification (NAA) on a chip. The biochip consisted of two layers incorporating a heater, a thermometer, an interdigital electrode (IDE) and a reaction chamber. The Pt electrode based heater and thermometer were utilized to maintain a specific temperature for the sample in the chamber. The thermometer exhibited a good linear correlation with a sensitivity of 9.36 Ω/°C and the heater achieved a heating efficiency of approximately 6.5 °C/s. Multiple ions were released during NAA, resulting in a decrease in the impedance of the amplification system solution. A large signal of impedance was generated by the released ions due to its linear correlation with the logarithm of the ion concentration. With this detection principle, IDE was employed for real-time monitoring of the in-chip reaction system impedance and NAA process. Specific nucleic acids from two pathogens (SARS-CoV-2, Vibrio vulnificus) were detected with this microsensor. The samples were qualitatively analyzed on microchip within 3 min, with a limit of detection (LOD) of 103 copies/µL. The proposed sensor presented several advantages, including reduced NAT time and increased sensitivity. Consequently, it has shown significant potential in rapid and high-quality nucleic acid testing for the field of epidemic prevention.


Assuntos
Técnicas Biossensoriais , Impedância Elétrica , Técnicas de Amplificação de Ácido Nucleico , SARS-CoV-2 , Técnicas Biossensoriais/métodos , SARS-CoV-2/isolamento & purificação , SARS-CoV-2/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Humanos , Limite de Detecção , Eletrodos , Dispositivos Lab-On-A-Chip , COVID-19/diagnóstico , COVID-19/virologia , Teste de Ácido Nucleico para COVID-19/métodos , Teste de Ácido Nucleico para COVID-19/instrumentação , RNA Viral/análise , RNA Viral/genética
5.
Org Lett ; 26(30): 6347-6352, 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39038192

RESUMO

Herein, we describe a novel photoinduced iron-catalyzed strategy for multicomponent C-H alkylation of in situ generated imines. By utilizing the alkyl radicals generated through iron-mediated photocatalytic C-H activation, the imines formed in situ are further subjected to addition reactions, resulting in the synthesis of various secondary and tertiary amine products. This method is simple to operate and does not require additional oxidants. It is applicable to inert alkane substrates such as cyclic alkanes, cyclic ethers, toluene, and ketones. The reaction is also compatible with various aromatic amines, alkyl amines, halogenated aromatic amines, as well as aromatic aldehydes, alkyl aldehydes, and cinnamaldehyde, among other different types of aldehydes.

6.
Clin Exp Med ; 24(1): 131, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38890201

RESUMO

To determine the diagnostic yield of Next-generation sequencing (NGS) in suspect Primary Immunodeficiencies Diseases (PIDs). This systematic review was conducted following PRISMA criteria. Searching Pubmed and Web of Science databases, the following keywords were used in the search: ("Next-generation sequencing") OR "whole exome sequencing" OR "whole genome sequencing") AND ("primary immunodeficiency disease" OR "PIDs"). We used STARD items to assess the risk of bias in the included studies. The meta-analysis included 29 studies with 5847 patients, revealing a pooled positive detection rate of 42% (95% CI 0.29-0.54, P < 0.001) for NGS in suspected PID cases. Subgroup analyses based on family history demonstrated a higher detection rate of 58% (95% CI 0.43-0.71) in patients with a family history compared to 33% (95% CI 0.21-0.46) in those without (P < 0.001). Stratification by disease types showed varied detection rates, with Severe Combined Immunodeficiency leading at 58% (P < 0.001). Among 253 PID-related genes, RAG1, ATM, BTK, and others constituted major contributors, with 34 genes not included in the 2022 IUIS gene list. The application of NGS in suspected PID patients can provide significant diagnostic results, especially in patients with a family history. Meanwhile, NGS performs excellently in accurately diagnosing disease types, and early identification of disease types can benefit patients in treatment.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala , Doenças da Imunodeficiência Primária , Humanos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Doenças da Imunodeficiência Primária/genética , Doenças da Imunodeficiência Primária/diagnóstico
7.
Neurol Sci ; 45(7): 3255-3266, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38277052

RESUMO

OBJECTIVE: To develop logistic regression nomogram and machine learning (ML)-based models to predict 3-month unfavorable functional outcome for acute ischemic stroke (AIS) patients undergoing reperfusion therapy. METHODS: Patients undergoing reperfusion therapy (intravenous thrombolysis and/or endovascular treatment) were prospectively recruited. Unfavorable outcome was defined as 3-month modified Rankin Scale (mRS) score 3-6. The independent risk factors associated with unfavorable outcome were obtained by regression analysis and included in the prediction model. The performance of nomogram was assessed by the area under the curve (AUC), calibration curve, and decision curve analysis (DCA). ML models were compared with nomogram using AUC; the generalizability of all models was ascertained in an external cohort. RESULTS: A total of 505 patients were enrolled, with 256 in the model construction, and 249 in the external validation. Five variables were identified as prognostic factors: baseline NIHSS, D-dimer level, random blood glucose (RBG), blood urea nitrogen (BUN), and systolic blood pressure (SBP) before reperfusion. The AUC values of nomogram were 0.865, 0.818, and 0.779 in the training set, test set, and external validation, respectively. The calibration curve and DCA indicated appreciable reliability and good net benefits. The best three ML models were extra trees (ET), CatBoost, and random forest (RF) models; all of them showed favorable discrimination in the training cohort, and confirmed in the test and external sets. CONCLUSION: Baseline NIHSS, D-dimer, RBG, BUN, and SBP before reperfusion were independent predictors for 3-month unfavorable outcome after reperfusion therapy in AIS patients. Both nomogram and ML models showed good discrimination and generalizability.


Assuntos
AVC Isquêmico , Aprendizado de Máquina , Nomogramas , Reperfusão , Humanos , Masculino , Feminino , AVC Isquêmico/terapia , AVC Isquêmico/diagnóstico , Idoso , Pessoa de Meia-Idade , Reperfusão/métodos , Prognóstico , Resultado do Tratamento , Terapia Trombolítica , Estudos Prospectivos
8.
Antioxidants (Basel) ; 11(10)2022 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36290739

RESUMO

Flavonoids have antimicrobial and anti-oxidation properties. The effects of the flavonoid quercetin on the intestinal microflora of freshwater dark sleeper Odontobutis potamophila were tested for the first time. Odontobutis potamophila juveniles were treated with quercetin for 21 days at one of three concentrations (2.5, 5.0, or 10.0 mg/L) and compared with a control group that was not treated with quercetin. Quercetin improved the stability of the intestinal flora in O. potamophila and the probiotic bacteria Bacillus spp. and Lactobacillus spp. increased in species abundance after the low concentration quercetin treatments. Furthermore, the abundance of pathogenic bacteria Plesiomonas spp., Aeromonas spp., and Shewanella spp. decreased after the fish had been exposed to quercetin. Activity of hepatic antioxidant enzymes (superoxide dismutase, SOD), (glutathione S-transferase, GST), (glutathione peroxidase, GSH-Px), and (total antioxidant capacity, T-AOC) increased in the livers of O. potamophila treated with quercetin, thereby increasing their hepatic antioxidant capacity and their ability to scavenge free radicals.

9.
Anal Biochem ; 656: 114877, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36055398

RESUMO

The lack of reliable and practical method for detecting rare hot mutation of epidermal growth factor receptor (EGFR) in circulating tumor DNA (ctDNA) for lung cancer has remained a challenge for general clinical application due to excess wild type DNA in clinical samples. In this study, we developed a droplet digital PCR (ddPCR) platform, integrating a PDMS chip and double-layer glass reservoir. The duplex T-junction droplet generators in PDMS chip can produce about one million uniform droplets of 4.187 pL within ∼10 min, which were then stored in the glass reservoir. The double-layer glass reservoir can protect droplets from evaporation and breaking, solving the problem of instability during thermal-cycling. The quantitative capabilities of the ddPCR chip were evaluated by testing EGFR exon gene 21, with a good linear correlation in the wide range of 101 to 106 copies/µL (R2 = 0.9998). We then demonstrated that the proposed ddPCR device can recognize rare EGFR L858R mutation under a background of 106 copies/µL wild-type DNA at a sensitivity of 0.0001%. Finally, we demonstrated this ddPCR platform could identify low amount of EGFR L858R mutation in ctDNA and CTCs of patients with lung cancer.


Assuntos
DNA Tumoral Circulante , Neoplasias Pulmonares , DNA Tumoral Circulante/genética , Receptores ErbB/genética , Genes erbB-1 , Humanos , Neoplasias Pulmonares/diagnóstico , Mutação , Reação em Cadeia da Polimerase/métodos
10.
Brain Sci ; 12(8)2022 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-36009062

RESUMO

Ischemic stroke is a life-threatening condition that also frequently results in long-term disability. Currently, intravenous thrombolysis with tissue plasminogen activator and mechanical thrombectomy is the most popular treatment. However, the narrow time window and related complications limit the treatment benefits. Exosomes have recently emerged as ideal therapeutic candidates for ischemic stroke with the ability to pass through the blood_brain barrier and mediate intercellular communication, in addition, exosomes and their contents can be bioengineered to implement targeted delivery. In the last two decades, exosomes and exosomal noncoding RNAs have been found to be involved in the pathophysiological progression of ischemic stroke, including atherosclerosis, apoptosis, inflammation, oxidative stress, and neurovascular remodeling. In this review, we describe the latest progress regarding the role of exosomal long noncoding RNAs and circular RNAs in the occurrence, progression, and recovery of ischemic stroke. Exploration of exosomal noncoding RNAs and their correlated effects in ischemic stroke may facilitate accurate diagnosis, and they may serve as new therapeutic targets for the disease.

11.
Front Genet ; 13: 938526, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35957695

RESUMO

Quercetin is a flavanol beneficial in reducing fat, promoting muscle growth, and Anti-oxidation. To study its effects in freshwater fish, the full-length cDNA of the follistatin (FST) and myostatin (MSTN) genes of the dark sleeper Odontobutis potamophila were cloned for the first time. Juvenile individual O. potamophila was exposed to quercetin at one of four concentrations (0, 2.5, 5, and 10 mg/L) for 21 days. The expression level of MSTN which inhibits muscle growth in the quercetin solution was lower than in the unexposed control group. The genes that promote muscle growth are in TGF-ß superfamily like FST, TGF-ß1 (transforming growth factor-beta 1), and Myogenic regulatory factors (MRFs) like Myf5 (myogenic factor 5), MyoD (myogenic differentiation), MyoG (myogenin), were higher than in the control group. Apolipoprotein and growth hormone receptor transcription levels in the quercetin-treated fish were significantly lower than in the control group. The concentrations of triglyceride, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol in the muscle tissue decreased, and the lipid-lowering function of quercetin was also demonstrated at the biochemical level. In this study, we analyzed the mRNA levels of AKT, Keap1 (kelch-like ECH-associated protein 1), Nrf2 (NF-E2-related factor 2) oxidation-related genes in the Nrf2/ARE antioxidant pathway, and Malondialdehyde (MDA), catalase (CAT) activity and glutathione (GSH) content in the hepatopancreas of O. potamophila after quercetin treatment, the mRNA expression of AKT, Nrf2 and CAT activity and GSH content are higher than in the control group. Quercetin enhances antioxidant properties and positively affects muscle growth. The results showed that quercetin has no significant effects on the growth performance of O. potamophila, but is effective in increasing muscle growth rate and lowering muscle fat content.

12.
Chemosphere ; 308(Pt 1): 136066, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35987273

RESUMO

Ubiquitous plastic pollution is a threat to the organisms' survival and ecosystem functions, especially in aquatic environments. Although there is increasing concern about the toxicity of microplastics, knowledge about the effects of microplastics of diverse sizes and adverse impacts on freshwater organisms is still limited. In the present study, the alteration in life-history traits, antioxidant defense and energy metabolism of the model freshwater zooplankton Daphnia pulex were assessed after chronic exposure to gradient concentrations (0.5, 1, 2 and 4 mg/L) of 500-nm polystyrene microplastics (PS-MPs). Changes in protein abundance were analyzed using proteomics after exposure to 1 mg/L of PS-MPs for 14 days. The results showed that ingested PS-MPs accumulated in the digestive tract of D. pulex. 2 and 4 mg/L of PS-MPs inhibited the survival function and 4 mg/L of PS-MPs reduced the body length of D. pulex after 14 or 21 days of exposure. The exposure did not decrease the fecundity of D. pulex. After 14 days of exposure, PS-MPs changed the antioxidant capacity in a dose-dependent way and all concentrations of PS-MPs induced lipid oxidative damage. Exposure to 500-nm PS-MPs for 14 days decreased glucose and fructose contents and disturbed the lipid transport and utilization in D. pulex. Meanwhile, PS-MPs activated DNA repair and transcription regulation but inhibited lipid metabolism and response to unfolded or misfolded proteins. These results indicated that chronic exposure to 500-nm PS-MPs negatively affected D. pulex and showed similar toxic mechanisms to smaller nano-sized microplastics. Exposure to 500-nm PS-MPs resulted in restricted resources such as inhibited antioxidant capacity or energy metabolisms and D. pulex showed a potential trade-off among life-history traits to maintain fecundity at the cost of self-maintenance. The present study offers perspectives for understanding the differences in ecological effects caused by microplastics of different sizes.


Assuntos
Microplásticos , Poluentes Químicos da Água , Animais , Antioxidantes/farmacologia , Daphnia , Ecossistema , Metabolismo Energético , Frutose/farmacologia , Glucose , Lipídeos , Microplásticos/toxicidade , Plásticos/toxicidade , Poliestirenos/toxicidade , Poluentes Químicos da Água/toxicidade
13.
Microsyst Nanoeng ; 8: 39, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35464881

RESUMO

Free chlorine is one of the key water quality parameters in tap water. However, a free chlorine sensor with the characteristics of batch processing, durability, antibiofouling/antiorganic passivation and in situ monitoring of free chlorine in tap water continues to be a challenging issue. In this paper, a novel silicon-based electrochemical sensor for free chlorine that can self-clean and be mass produced via microfabrication technique/MEMS (Micro-Electro-Mechanical System) is proposed. A liquid-conjugated Ag/AgCl reference electrode is fabricated, and electrochemically stable BDD/Pt is employed as the working/counter electrode to verify the effectiveness of the as-fabricated sensor for free chlorine detection. The sensor demonstrates an acceptable limit of detection (0.056 mg/L) and desirable linearity (R 2 = 0.998). Particularly, at a potential of +2.5 V, hydroxyl radicals are generated on the BBD electrode by electrolyzing water, which then remove the organic matter attached to the surface of the sensor though an electrochemical digestion process. The performance of the fouled sensor recovers from 50.2 to 94.1% compared with the initial state after self-cleaning for 30 min. In addition, by employing the MEMS technique, favorable response consistency and high reproducibility (RSD < 4.05%) are observed, offering the opportunity to mass produce the proposed sensor in the future. A desirable linear dependency between the pH, temperature, and flow rate and the detection of free chlorine is observed, ensuring the accuracy of the sensor with any hydrologic parameter. The interesting sensing and self-cleaning behavior of the as-proposed sensor indicate that this study of the mass production of free chlorine sensors by MEMS is successful in developing a competitive device for the online monitoring of free chlorine in tap water.

14.
Gene ; 813: 146102, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34933078

RESUMO

Here we report the first mitochondrial genomes (mitogenomes) of four species of gecarcinucid freshwater crabs (FWCs) in two genera, two from China (Somanniathelphusa hainanensis and S. yangshanensis), one from Laos (Esanthelphusa dugasti), and one from Myanmar (Esanthelphusa keyini). A novel gecarcinucid mitochondrial gene order (GMGO2) that was only found in E. dugasti that contains a total of 42 genes, including one pseudogene, two remolded tRNAs and two duplicated tRNAs. The GMGO2 of E. dugasti was compared with the brachyuran ground-pattern mitochondrial gene order (BMGO), revealing the rearrangements of the positions of 10 tRNAs, two PCGs, and one mNCR. The three other gecarcinucids in this study were all found to possess a previously reported gecarcinucid mitochondrial gene order (GMGO1). The phylogenetic tree reconstructed using the secondary structures of 22 tRNAs of the mitogenomes of 41 species of FWCs provides insights into the evolution of the mitogenome of E. dugasti (GMGO2) which includes remolded and duplicated tRNAs.


Assuntos
Braquiúros/genética , Animais , China , Evolução Molecular , Água Doce , Ordem dos Genes/genética , Rearranjo Gênico/genética , Genes Mitocondriais/genética , Genoma Mitocondrial , Laos , Mianmar , Filogenia , RNA Ribossômico/genética , RNA de Transferência/genética
15.
Sci Rep ; 11(1): 15021, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34294825

RESUMO

The Asian Clam (Corbicula fluminea) is a valuable commercial and medicinal bivalve, which is widely distributed in East and Southeast Asia. As a natural nutrient source, the clam is rich in protein, amino acids, and microelements. The genome of C. fluminea has not yet been characterized; therefore, genome-assisted breeding and improvements cannot yet be implemented. In this work, we present a de novo chromosome-scale genome assembly of C. fluminea using PacBio and Hi-C sequencing technologies. The assembled genome comprised 4728 contigs, with a contig N50 of 521.06 Kb, and 1,215 scaffolds with a scaffold N50 of 70.62 Mb. More than 1.51 Gb (99.17%) of genomic sequences were anchored to 18 chromosomes, of which 1.40 Gb (92.81%) of genomic sequences were ordered and oriented. The genome contains 38,841 coding genes, 32,591 (83.91%) of which were annotated in at least one functional database. Compared with related species, C. fluminea had 851 expanded gene families and 191 contracted gene families. The phylogenetic tree showed that C. fluminea diverged from Ruditapes philippinarum, ~ 228.89 million years ago (Mya), and the genomes of C. fluminea and R. philippinarum shared 244 syntenic blocks. Additionally, we identified 2 MITF members and 99 NLRP members in C. fluminea genome. The high-quality and chromosomal Asian Clam genome will be a valuable resource for a range of development and breeding studies of C. fluminea in future research.


Assuntos
Cromossomos , Corbicula/classificação , Corbicula/genética , Estudos de Associação Genética , Genoma , Genômica , Animais , Biologia Computacional/métodos , Genômica/métodos , Anotação de Sequência Molecular , Família Multigênica , Filogenia , Sequências Repetitivas de Ácido Nucleico
17.
Anal Chim Acta ; 1164: 338511, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33992215

RESUMO

Pollution due to heavy metals is becoming increasingly hazardous; therefore, demand for the large-scale deployment of sensor nodes for water quality monitoring has increased. The development of integrated and miniaturised sensors for detecting heavy metals is necessary. Herein, an integrated microfluidic sensor based on a "glass-silicon-glass" sandwich structure is proposed for Pb2+ detection. This micro-sensor consists of a nanochannel liquid conjunct Ag/AgCl reference electrode(RE), a working electrode with a three-dimensional Au micropillar array, and a detection chamber for sample measurement. The potential fluctuation of the RE in this sensor was only 0.62% over seven days, remaining relatively stable. Under optimal conditions, the limit of detection and sensitivity for lead were 0.13 µg L-1 (S/N = 3) and 52.30 nA (µg L-1)-1, respectively. The linearity of the sensor for detecting lead was good in the concentration range of 0.50-150 µg L-1 (R2 = 0.9989). Moreover, the proposed microsensor showed high selectivity for Pb2+ and achieved sensitive detection of trace Pb2+ in different water samples. Therefore, this integrated and miniaturised sensor is a practical tool for trace lead detection, allowing the development of large scale sensor network for water monitoring.

18.
Mitochondrial DNA B Resour ; 6(4): 1369-1371, 2021 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-33889753

RESUMO

The freshwater gammarid Grandidierella taihuensis is an important composition of benthic community. In this study, the complete mitogenome sequences of G. taihuensis are determined using next-generation and PacBio long-read sequencing. The mitogenome of G. taihuensis is 15,099 bp in size, and consisted of 13 protein-coding genes, two ribosomal RNA genes, 22 tRNA genes, and a putative control region. Gene arrangement is as same as that of G. rubroantennata. The base composition of the entire mitogenome showed a conspicuous A + T bias of 69.4%. The mitogenome data produced in this study provides a useful resource for future evolutionary and ecological studies.

19.
Talanta ; 226: 122101, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33676657

RESUMO

Temperature changes in cells are generally accompanied by physiological processes. Cellular temperature measurements can provide important information to fully understand cellular mechanisms. However, temperature measurements with conventional methods, such as fluorescent polymeric thermometers and thermocouples, have limitations of low sensitivity or cell state disturbance. We developed a microfluidic chip integrating a high-precision platinum (Pt) thermo-sensor that can culture cells and monitor the cellular temperature in situ. During detection, a constant temperature system with a stability of 0.015 °C was applied. The temperature coefficient of resistance of the Pt thermo-sensor was 2090 ppm/°C, giving a temperature resolution of the sensor of less than 0.008 °C. This microchip showed a good linear correlation between the temperature and resistance of the Pt sensor at 20-40 °C (R2 = 0.999). Lung and liver cancer cells on the microchip grew normally and continuously. The maximum temperature fluctuation of H1975 (0.924 °C) was larger than that of HepG2 (0.250 °C). However, the temperature of adherent HepG2 cells changed over time, showing susceptibility to the environment most of the time compared to H1975. Moreover, the temperature increment of non-cancerous cells, such as hepatic stellate cells, was monitored in response to the stimulus of paraformaldehyde, showing the process of cell death. Therefore, this thermometric microchip integrated with cell culture could be a non-disposable and label-free tool for monitoring cellular temperature applied to the study of physiology and pathology.


Assuntos
Neoplasias , Fenômenos Fisiológicos , Termometria , Humanos , Microfluídica , Termômetros
20.
Talanta ; 226: 122172, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33676714

RESUMO

Lung cancer is one of the common malignant tumors with a high incidence and mortality rate. Targeted therapies are efficient on lung cancer patients with specific gene mutations. Circulating tumor cells (CTCs) are used for liquid biopsy, providing genetic information for lung cancer treatment selection and prognosis. We developed a less costly self-driving micro-cavity array for simple molecular analysis at a single cell level to examine the genetic make-up of CTCs. This chip integrated sample detection structure and vacuum driving system to achieve cell loading, lysing, isothermal amplification (LAMP), and signal read-out on one chip. We used the "film-polydimethylsiloxane (PDMS) chip-film" structure and oil sealing method during amplification reaction to minimize water loss. We then conducted a LAMP assay using the self-driving device to detect epidermal growth factor receptor (EGFR) L858R mutation and identified an excellent linear in the range between 101-104 copies/µL (R2 = 0.997). We finally assessed the EGFR L858R gene expression of lung tumor cells (H1975 cells) as putative CTCs using the proposed detection platform. We discovered its ability to perform genetic analysis at the single-cell level. The EGFR L858R mutational gene expression levels were different in H1975 cells. In conclusion, the self-driving micro-cavity array is a less costly and simple tool for mutational gene profiling of single lung CTC. Besides, it can be used in personalized therapy and efficacy monitoring.


Assuntos
Receptores ErbB , Neoplasias Pulmonares , Receptores ErbB/genética , Humanos , Pulmão , Neoplasias Pulmonares/genética , Técnicas de Diagnóstico Molecular , Mutação , Técnicas de Amplificação de Ácido Nucleico , Análise de Célula Única
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