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1.
Materials (Basel) ; 17(9)2024 Apr 24.
Article in English | MEDLINE | ID: mdl-38730766

ABSTRACT

With the rapid development of high and new technology, rubidium and its compounds show broad application prospect and market demand with their unique characteristics. At present, the production of rubidium metal is mainly prepared by calcium thermal reduction of rubidium chloride. Rubidium metal obtained by reduction requires multi-step vacuum distillation to obtain high-purity rubidium metal. The purity of rubidium metal depends on the purity of the raw material rubidium chloride. Rubidium metal is relatively active and is easy to oxidize and explode in air. Therefore, a method combining vacuum decomposition and vacuum distillation to reduce impurity elements in rubidium chloride from raw materials is proposed in this paper. The experimental results show that under the conditions of pressure of 5-10 Pa, distillation temperature of 823 K and vacuum distillation time of 60 min, the contents of Si and Zn impurities are reduced from 1206 mg/kg and 310 mg/kg to less than 0.1 mg/kg, and the removal rates are 99.99% and 99.97%, respectively. Rubidium chloride has almost no loss, and through one-step vacuum distillation, the impurity elements silicon and zinc can be deeply removed, reducing the flammability and explosiveness, high cost, long process and other problems caused by the subsequent preparation of high-purity rubidium metal.

2.
Int J Biol Macromol ; 270(Pt 2): 132191, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38729466

ABSTRACT

Obtaining lignin-based graphite-like microcrystallites at a relatively low carbonization temperature is still very challenging. In this work, we report a new method based on condensed structures, for regulating graphite-like microcrystalline structures via the incorporation of 4,4'-diphenylmethane diisocyanate (MDI) into the main structure of lignin. The effects of MDI on the thermal properties of lignin and the graphite-like microcrystalline structure of lignin-based ultrafine carbon fibers were extensively studied and investigated. The incorporation of MDI decreased the thermal stability of lignin, increased the carbon yield and enhanced the formation of graphite-like microcrystallites, which are beneficial for reducing energy consumption during the preparation of lignin-based carbon fibers. The modified lignin-based ultrafine carbon fibers (M-LCFs) demonstrated satisfactory electrochemical performance, including high specific capacitance, low charge transfer resistance, and good cycle performance. The M-LCFs-3/2 electrode had a specific capacitance of 241.3 F g-1 at a current density of 0.5 A g-1, and a residual ratio of 90.2 % after 2000 charge and discharge cycles. This study provides a new approach to control the graphite-like microcrystalline structure and electrochemical performance while also optimizing the temperature.


Subject(s)
Carbon Fiber , Graphite , Lignin , Lignin/chemistry , Graphite/chemistry , Carbon Fiber/chemistry , Crystallization , Temperature , Electric Capacitance , Electrodes , Carbon/chemistry
3.
Front Public Health ; 12: 1308486, 2024.
Article in English | MEDLINE | ID: mdl-38566801

ABSTRACT

Background: Turnover intention is one of the common disturbances that affect the career development and management of university teachers. With an aim to solve this thorny issue, the study examined the associations between turnover intention and work stress among local undergraduate university teachers in China. Methods: A questionnaire survey was carried out on 7,565 local university teachers. Initially, confirmatory factor analysis was employed to validate the reliability and validity of the scale. Subsequently, descriptive statistics and correlation analyses were conducted. Following this, a latent moderated structural equation (LMS) was used to explore the relationship among work stress, job burnout, self-efficacy, and turnover intention. Moreover, the bias-corrected Bootstrap method was applied to further examine the mediating effects, moderating effects, and moderated mediating effects in the model. Results: The hypothesized moderated mediation model was verified significant. Work stress directly and positively predicted job burnout and turnover intention, with job burnout serving a partial mediating role between work stress and turnover intention. Additionally, self-efficacy negatively moderated the direct impact of work stress on job burnout, as well as the mediating effect of job burnout. As the self-efficacy of university teachers increased, the direct effect of work stress on job burnout and the mediating effect of job burnout decreased. Conclusion: This study expanded the research on the antecedent variables of university teachers' turnover intention and revealed the individual contingency mechanism by which work stress affected turnover intention: the negative moderating effect of self-efficacy. Work stress induced university teachers' turnover intention, and this phenomenon was more obvious for faculties with low self-efficacy. Administrators of local undergraduate universities need to rationalize the allocation of teachers' job responsibilities and pay attention to the negative consequences of work stress in order to reduce turnover intentions. Particular attention should be paid to enhance teachers' self-efficacy. The findings of this study can provide in-depth recommendations for university faculty management and policy making, which can help shape a working atmosphere more conducive to teaching and research, thus enhancing the overall quality and competitiveness of faculty members within universities.


Subject(s)
Burnout, Professional , Intention , Humans , Self Efficacy , Universities , Reproducibility of Results , Job Satisfaction , Cross-Sectional Studies , China
4.
ACS Appl Mater Interfaces ; 16(13): 16800-16808, 2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38517155

ABSTRACT

Flexible organic thermoelectric generators are gaining prominence in wearable electronics, leveraging body heat as an energy source. Their advancement is hindered by the scarcity of air-stable n-type organic materials with robust mechanical properties. This study introduces two new polymers (HDCN4 and HDCN8), created through polycondensation of paraformaldehyde and diamine-terminated poly(ethylene glycol) (PEGDA) with molecular weights of 4000 and 8000 g/mol into single-walled carbon nanotubes (SWCNTs). The resulting HDCN4/SWCNT and HDCN8/SWCNT composites show impressive power factors of 225.9 and 108.2 µW m-1 K-2, respectively, and maintain over 90% in air for over four months without encapsulation. The HDCN4/SWCNT composite also demonstrates significant tensile strength (33.2 MPa) and flexibility (up to 10% strain), which is currently the best mechanically n-type thermoelectric material with such a high power factor reported in the literature. A thermoelectric device based on HDCN4/SWCNT generates 4.2 µW of power with a 50 K temperature difference. Additionally, when used in wearable temperature sensors, these devices exhibit high mechanical reliability and a temperature resolution of 0.1 K. This research presents a viable method to produce air-stable n-type thermoelectric materials with excellent performance and mechanical properties.

5.
Front Pharmacol ; 15: 1353620, 2024.
Article in English | MEDLINE | ID: mdl-38333009

ABSTRACT

Introduction: Postoperative nausea and vomiting (PONV) is a prevalent postsurgical complication. The objective of our study was to compare the effect of different doses of dexmedetomidine on PONV in female patients undergoing radical thoracoscopic lung cancer resection. Methods: A total of 164 female patients undergoing elective thoracoscopic radical lung cancer surgery were enrolled and assigned to one of four groups. Patients received 0.2 µg/kg/h, 0.4 µg/kg/h, 0.8 µg/kg/h dexmedetomidine and normal saline in the Dex1, Dex2, Dex3 and Control groups, respectively. The primary outcome was the incidence of PONV during 48 h postoperatively. The second outcomes included the incidence of PONV and postoperative vomiting (POV) at four time points postoperatively (T1: PACU retention period; T2: PACU discharge to postoperative 12 h; T3: postoperative 12 h-postoperative 24 h; T4: postoperative 24 h-postoperative 48 h), the area under the curve of PONV grade (PONVAUC), PONV grade, POV grade and other postoperative recovery indicators. Results: The incidence of PONV differed among the four groups. The Dex2 group (29.27%) was lower than that in the Dex1 group (61.90%) and Control group (72.50%). The incidence of PONV at T2 in the Dex1 group (11.90%) and Dex2 group (9.76%) was lower than that in the Control group (42.50%). The incidence of PONV at T3 in the Dex2 group (29.27%) was lower than that in the Dex1 group (61.90%) and Control group (62.50%). The PONVAUC was lower in the Dex2 group than in the Control group. The incidence of POV at T3 in the Dex2 and Dex3 groups was lower than that in the Control group. The consumption of remifentanil, norepinephrine, PACU dwell time, VAS scores, postoperative PCA press frequency, and the time for the first postoperative oral intake were different among the four groups. The regression model shows that the Dex2 group is a protective factor for PONV. Conclusion: Dexmedetomidine can reduce the incidence of PONV and accelerate postoperative recovery in female patients undergoing radical thoracoscopic lung cancer resection. Compared with the other two dosages, 0.4 µg/kg/h dexmedetomidine is preferable. Clinical Trial Registration: chictr.org.cn, identifier ChiCTR2300071831.

6.
Int J Surg Case Rep ; 111: 108911, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37804678

ABSTRACT

INTRODUCTION AND IMPORTANCE: Pulmonary hernia is a rare disease caused mostly by chest trauma. Patients often present with non-specific signs and symptoms. Currently, there is no unified approach to treating it. For asymptomatic pulmonary hernias, conservative treatment has been chosen in the past. However, the increasing number of cases has shown that surgery has a more positive effect on some patients with asymptomatic pulmonary hernias. CASE PRESENTATION: A 63-year-old female patient who accidentally fell from an agricultural vehicle while doing farm work presented with back pain and lower limb paralysis. Her vital signs were stable. A chest computed tomography (CT) scan showed the patient had a pulmonary hernia, thoracic vertebra Chance fracture, rib fractures, and right hydropneumothorax. The patient received an open reduction internal fixation (ORIF) of the thoracic vertebra at the trauma emergency center. The postoperative chest CT scan showed that the pulmonary hernia had reset to the chest cavity. Subsequently, the patient got a pulmonary hernia repair at the thoracic surgery department. The patient was discharged on the 19th day after the injury. Long-term follow-up showed good recovery from the thoracic trauma. CLINICAL DISCUSSION: The patient had a pulmonary hernia combined with thoracic Chance fracture and other injuries. Surgical repair achieved satisfactory results. CONCLUSION: We lack guidelines on whether to manage pulmonary hernias surgically. Patients with asymptomatic pulmonary hernias particularly should have their long-term prognoses fully evaluated. Surgery is needed if the patient has high-risk factors and severe intercostal muscle defects.

7.
Aging (Albany NY) ; 15(18): 9544-9560, 2023 Sep 18.
Article in English | MEDLINE | ID: mdl-37724890

ABSTRACT

Inflammation of chondrocytes plays a critical role in the occurrence and development of osteoarthritis (OA). Recent evidence indicated exosomes derived from mesenchymal stem cells (MSCs-Exos) exhibit excellent anti-inflammatory ability in many troublesome inflammatory diseases including OA. In the present study, we aimed to explore the role of human umbilical cord-derived MSCs-Exos (hUC-MSCs-Exos) in treating the inflammation of chondrocytes and its related mechanisms. Ultracentrifugation was applied to isolate hUC-MSCs-Exos from the culture supernatant of hUC-MSCs. Two OA-like in vitro inflammation models of human articular chondrocytes induced with interleukin 1ß (IL-1ß) and co-incubation with macrophage utilizing transwell cell culture inserts were both used to evaluate the anti-inflammatory effects of hUC-MSCs-Exos. The mRNA sequencing of chondrocytes after treatment and microRNA (miRNA) sequencing of hUC-MSCs-Exos were detected and analyzed for possible mechanism analysis. The results of the study confirmed that hUC-MSCs-Exos had a reversed effect of IL-1ß on chondrocytes in the expression of collagen type II alpha 1 (COL2A1) and matrix metalloproteinase 13 (MMP13). The addition of hUC-MSCs-Exos to M1 macrophages in the upper chamber showed down-regulation of IL-1ß and tumor necrosis factor α (TNF-α), up-regulation of IL-10 and arginase1 (ARG1), and reversed the gene and protein expression of COL2A1 and MMP13 of the chondrocytes seeded in the lower chamber. The results of this study confirmed the anti-inflammatory effects of hUC-MSCs-Exos in the human articular chondrocytes inflammation model. hUC-MSCs-Exos may be used as a potential cell-free treatment strategy for chondrocyte inflammation in OA.

8.
Adv Sci (Weinh) ; 10(23): e2301094, 2023 08.
Article in English | MEDLINE | ID: mdl-37279389

ABSTRACT

Male-specific lethal 1 (MSL1) is critical for the formation of MSL histone acetyltransferase complex which acetylates histone H4 Lys16 (H4K16ac) to activate gene expression. However, the role of MSL1 in liver regeneration is poorly understood. Here, this work identifies MSL1 as a key regulator of STAT3 and histone H4 (H4) in hepatocytes. MSL1 forms condensates with STAT3 or H4 through liquid-liquid phase separation to enrich acetyl-coenzyme A (Ac-CoA), and Ac-CoA in turn enhances MSL1 condensate formation, synergetically promoting the acetylation of STAT3 K685 and H4K16, thus stimulating liver regeneration after partial hepatectomy (PH). Additionally, increasing Ac-CoA level can enhance STAT3 and H4 acetylation, thus promoting liver regeneration in aged mice. The results demonstrate that MSL1 condensate-mediated STAT3 and H4 acetylation play an important role in liver regeneration. Thus, promoting the phase separation of MSL1 and increasing Ac-CoA level may be a novel therapeutic strategy for acute liver diseases and transplantation.


Subject(s)
Histones , Liver Regeneration , Male , Mice , Animals , Histones/genetics , Acetylation , Cell Nucleus/metabolism
9.
Bioorg Med Chem Lett ; 91: 129365, 2023 07 15.
Article in English | MEDLINE | ID: mdl-37290494

ABSTRACT

The use of light to activate prodrugs offers a promising method for the precise control of drug release, reducing drug-related side effects, and enhancing therapeutic effectiveness. We have created a novel prodrug system that utilizes a unique, heavy-atom-free photosensitizer to produce singlet oxygen, which then triggers the conversion of the prodrug into its active form. This system has been successfully demonstrated through the creation of "photo-unclick" prodrugs of paclitaxel (PTX), combretastatin A-4 (CA-4), and 10-hydroxy-7-ethylcamptothecin (SN-38). These prodrugs show decreased toxicity in the absence of light, but exhibit increased toxicity when exposed to red light.


Subject(s)
Photosensitizing Agents , Prodrugs , Cell Line, Tumor , Light , Paclitaxel/pharmacology , Photosensitizing Agents/pharmacology , Prodrugs/pharmacology , Singlet Oxygen
10.
Front Med (Lausanne) ; 10: 1180845, 2023.
Article in English | MEDLINE | ID: mdl-37351073

ABSTRACT

Background: The effect of sex and age on chronic post-thoracic surgical pain (CPTP) at rest and with activity remains unclear. The main purpose of this study was to investigate the relationship between the incidence of chronic postoperative pain (at rest and with activity) and sex/age differences. Methods: This was a single-center retrospective study that included adult patients who had undergone elective thoracic surgery. Patients were divided into two groups based on sex. Demographic and perioperative data were collected, including age, sex, education level, Body Mass Index (BMI), American Society of Anesthesiologists (ASA) physical status, and medical history (hypertension, diabetes mellitus). Chronic postoperative pain data were collected by telephone follow-up. Results: Among the 3,159 patients enrolled, 1,762 were male, and 1,397 were female. After creating a matched-pairs cohort, 1,856 patients were analyzed. The incidence of CPTP at rest was 14.9% among males and 17.8% among females (p = 0.090). The incidence of CPTP with activity was 28.4% among males and 35.0% among females (p = 0.002). We analyzed three different models after propensity matching to validate the stability of the prediction model between sex and CPTP, and female sex was a significant predictor of CPTP with activity 3 months after surgery. Further analysis showed that females in the 45-55-year-old age group were more prone to develop CPTP. Conclusion: Females have a higher incidence of chronic postoperative pain with activity after thoracic surgery. Females in the 45-55-year-old age group are more prone to develop CPTP than females in other age groups.

11.
Plant Cell Rep ; 42(7): 1251-1254, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37052713

ABSTRACT

KEY MESSAGE: We explored the phylogenomics and methylomics of NLR genes in 41 plant species and found that highly duplicated plant NLR genes are hyper methylated in non-CG context.


Subject(s)
DNA Methylation , Disease Resistance , DNA Methylation/genetics , Disease Resistance/genetics , Genes, Plant/genetics
12.
Am J Transl Res ; 15(3): 2256-2267, 2023.
Article in English | MEDLINE | ID: mdl-37056802

ABSTRACT

OBJECTIVE: This study aimed to investigate the effect of preoperative current smoking on chronic postsurgical pain in patients who underwent thoracic surgery. METHODS: A total of 5,395 patients aged over 18 years old who underwent thoracic surgery from January 2016 to March 2020 in Henan Provincial People's Hospital were enrolled. Patients were divided into two groups: the smoking group (SG group) and the nonsmoking group (NSG group). Propensity score matching was utilized to eliminate the influence of confounding factors, and a multivariable logistic regression model was established to determine the effect of preoperative current smoking on chronic postsurgical pain. The dose-response relationship between the smoking index (SI) and chronic postsurgical pain at rest was analyzed using a restricted cubic spline curve. RESULTS: In a matched cohort of 1028 patients, the incidence of chronic pain at rest was 13.2% in the smoking group and 19.0% in the nonsmoking group (P = 0.011). Three different models were used to verify the stability of the model between preoperative current smoking and chronic postsurgical pain. A regression model was established to determine the influence of different smoking indexes (SIs) on chronic postsurgical pain. The incidence of chronic pain at rest was lower in patients with SI ≥400 before thoracic surgery than in patients whose SI was less than 400. CONCLUSIONS: A relationship between the preoperative current smoking index and chronic postsurgical pain at rest was observed. The incidence of chronic postsurgical pain at rest was lower in patients whose SI was greater than 400.

13.
Plant Physiol Biochem ; 197: 107624, 2023 Apr.
Article in English | MEDLINE | ID: mdl-36948023

ABSTRACT

In high-cold regions, alfalfa is susceptible to cold damage during the seed germination. The effects of discontinuous low temperature stress and plant growth regulators (PGRs) on alfalfa were studied in response to the high day/night temperature differentials in the area. The experiments included seed germination, seedling cold tolerance and plant recovery. Variable temperatures (VT) of 0 °C/15 °C, 5 °C/20 °C and 10 °C/25 °C were set and seeds were soaked with alginate oligosaccharides (AOS), brassinolide (BR) and diethyl aminoethyl hexanoate (DA-6) during the germination period. Parameters such as seed germination and mean germination time (MGT), phenylalanine ammonia-lyase (PAL) activity and oligomeric proanthocyanidins (OPC) content of early seedlings, dry matter accumulation and root crown of the restored plants were analysed. The results showed that low variable-temperature (LVT) stress prolonged the MGT but had little inhibitory effect on germination percentage. Early seedlings adapted to LVT stress by regulating their own water and OPC content, PAL activity and other parameters. LVT induced early alfalfa seedlings to increase their underground biomass by shortening root length and increasing root diameter, and those that had accumulated more underground biomass had faster growth rates and higher total biomass when the ambient temperature rose. AOS also promoted an increase in root crown diameter and root dry weight. This research proved that LVT stress and AOS during the germination process can lead to better growth of alfalfa in high cold regions.


Subject(s)
Germination , Medicago sativa , Temperature , Plant Growth Regulators/pharmacology , Seedlings , Antioxidants/pharmacology , Seeds , Plant Roots
14.
Psychol Res Behav Manag ; 16: 197-209, 2023.
Article in English | MEDLINE | ID: mdl-36699987

ABSTRACT

Purpose: This paper reveals the mechanism of the influence of belief in a just world on college students' learning satisfaction, and provides reference for further improving the quality of talent training in higher education. Methods: By convenient sampling method, 131,894 college students from 348 undergraduate universities in China were investigated on the belief in a just world scale, gratitude scale, learning engagement scale and learning satisfaction scale. Then, SPSS, AMOS and other software were used to analyze the data. Results: 1) Belief in a just world, gratitude, learning engagement and learning satisfaction are positively correlated. 2) Belief in a just world can not only directly and positively predict college students' learning satisfaction, but also indirectly and positively predict college students' learning satisfaction through gratitude and learning engagement respectively. 3) Gratitude and learning engagement play a chain mediating role between belief in a just world and learning satisfaction. Conclusion: Belief in a just world positively predicts college students' learning satisfaction through gratitude and learning engagement, suggesting that colleges and universities should create a fair learning environment and enhance college students' sense of gratitude, so as to improve college students' belief in a fair world and gratitude level, thus promoting their learning engagement and finally improving their learning satisfaction.

15.
Ecotoxicol Environ Saf ; 252: 114579, 2023 Mar 01.
Article in English | MEDLINE | ID: mdl-36706527

ABSTRACT

Large amounts of insecticides bring selection pressure and then develop insecticide resistance in Aedes albopictus. This study demonstrated for the first time the effect of pyrethroid exposure on the internal microbiota in Ae. albopictus. 36, 48, 57 strains of virgin adult Ae. albopictus were exposed to the pyrethroids deltamethrin (Dme group), ß-cypermethrin (Bcy group), and cis-permethrin (Cper group), respectively, with n-hexane exposure (Hex group) as the controls (n = 36). The internal microbiota community and functions were analyzed based on the metagenomic analysis. The analysis of similarity (ANOSIM) results showed that the Hex/Bcy (p = 0.001), Hex/Cper (p = 0.006), Hex/Dme (p = 0.001) groups were well separated, and the internal microbes of Ae. albopictus vary in the composition and functions depending on the type of pyrethroid insecticide they are applied. Four short chain fatty acid-producing genera, Butyricimonas, Prevotellaceae, Anaerococcus, Pseudorhodobacter were specifically absent in the pyrethroid-exposed mosquitoes. Morganella and Streptomyces were significantly enriched in cis-permethrin-exposed mosquitoes. Wolbachia and Chryseobacterium showed significant enrichment in ß-cypermethrin-exposed mosquitoes. Pseudomonas was significantly abundant in deltamethrin-exposed mosquitoes. The significant proliferation of these bacteria may be closely related to insecticide metabolism. Our study recapitulated a specifically enhanced metabolic networks relevant to the exposure to cis-permethrin and ß-cypermethrin, respectively. Benzaldehyde dehydrogenase (EC 1.2.1.28), key enzyme in aromatic compounds metabolism, was detected enhanced in cis-permethrin and ß-cypermethrin exposed mosquitoes. The internal microbiota metabolism of aromatic compounds may be important influencing factors for pyrethroid resistance. Future work will be needed to elucidate the specific mechanisms by which mosquito microbiota influences host resistance and vector ability.


Subject(s)
Aedes , Insecticides , Microbiota , Pyrethrins , Animals , Insecticides/pharmacology , Permethrin/toxicity , Mosquito Vectors , Pyrethrins/pharmacology , Insecticide Resistance/genetics
16.
J Exp Bot ; 74(3): 1074-1089, 2023 02 05.
Article in English | MEDLINE | ID: mdl-36402551

ABSTRACT

Plants have evolved delicate systems for stimulating or inhibiting inorganic phosphate (Pi) uptake in response to the fluctuating Pi availability in soil. However, the negative regulators inhibiting Pi uptake at the transcriptional level are largely unexplored. Here, we functionally characterized a transcription factor in rice (Oryza sativa), OsWRKY10. OsWRKY10 encodes a nucleus-localized protein and showed preferential tissue localization. Knockout of OsWRKY10 led to increased Pi uptake and accumulation under Pi-replete conditions. In accordance with this phenotype, OsWRKY10 was transcriptionally induced by Pi, and a subset of PHOSPHATE TRANSPORTER 1 (PHT1) genes were up-regulated upon its mutation, suggesting that OsWRKY10 is a transcriptional repressor of Pi uptake. Moreover, rice plants expressing the OsWRKY10-VP16 fusion protein (a dominant transcriptional activator) accumulated even more Pi than oswrky10. Several lines of biochemical evidence demonstrated that OsWRKY10 directly suppressed OsPHT1;2 expression. Genetic analysis showed that OsPHT1;2 was responsible for the increased Pi accumulation in oswrky10. Furthermore, during Pi starvation, OsWRKY10 protein was degraded through the 26S proteasome. Altogether, the OsWRKY10-OsPHT1;2 module represents a crucial loop in the Pi signaling network in rice, inhibiting Pi uptake when there is ample Pi in the environment.


Subject(s)
Oryza , Oryza/genetics , Oryza/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Phosphates/metabolism , Phosphate Transport Proteins/genetics , Phosphate Transport Proteins/metabolism , Gene Expression Regulation, Plant , Plant Proteins/genetics , Plant Proteins/metabolism , Plants, Genetically Modified/genetics , Plant Roots/metabolism
17.
J Am Chem Soc ; 144(51): 23668-23676, 2022 12 28.
Article in English | MEDLINE | ID: mdl-36511618

ABSTRACT

The second near-infrared (NIR-II, 1000-1700 nm) fluorescent probes have significant advantages over visible or NIR-I (600-900 nm) imaging for both depth of penetration and level of resolution. Since the blood-brain barrier (BBB) prevents most molecules from entering the central nervous system, NIR-II dyes with large molecular frameworks have limited applications for brain imaging. In this work, we developed a series of boron difluoride (BF2) formazanate NIR-II dyes, which had tunable photophysical properties, ultrahigh photostability, excellent biological stability, and strong brightness. Modulation of the aniline moiety of BF2 formazanate dyes significantly enhances their abilities to cross the BBB for noninvasive brain imaging. Furthermore, the intact mouse brain imaging and dynamic dye diffusion across the BBB were monitored using these BF2 formazanate dyes in the NIR-II region. In murine glioblastoma models, these dyes can differentiate tumors from normal brain tissues. We anticipate that this new type of small molecule will find potential applications in creating probes and drugs relevant to theranostic for brain pathologies.


Subject(s)
Blood-Brain Barrier , Neoplasms , Animals , Mice , Brain/diagnostic imaging , Fluorescent Dyes , Optical Imaging/methods , Neuroimaging
18.
Chem Sci ; 13(42): 12540-12549, 2022 Nov 02.
Article in English | MEDLINE | ID: mdl-36382293

ABSTRACT

Proper three-dimensional structures are essential for maintaining the functionality of proteins and for avoiding pathological consequences of improper folding. Misfolding and aggregation of proteins have been both associated with neurodegenerative disease. Therefore, a variety of fluorogenic tools that respond to both polarity and viscosity have been developed to detect protein aggregation. However, the rational design of highly sensitive fluorophores that respond solely to polarity has remained elusive. In this work, we demonstrate that electron-withdrawing heteroatoms with (d-p)-π* conjugation can stabilize lowest unoccupied molecular orbital (LUMO) energy levels and promote bathochromic shifts. Guided by computational analyses, we have devised a novel series of xanthone-based solvatochromic fluorophores that have rarely been systematically studied. The resulting probes exhibit superior sensitivity to polarity but are insensitive to viscosity. As proof of concept, we have synthesized protein targeting probes for live-cell confocal imaging intended to quantify the polarity of misfolded and aggregated proteins. Interestingly, our results reveal several layers of protein aggregates in a way that we had not anticipated. First, microenvironments with reduced polarity were validated in the misfolding and aggregation of folded globular proteins. Second, granular aggregates of AgHalo displayed a less polar environment than aggregates formed by folded globular protein represented by Htt-polyQ. Third, our studies reveal that granular protein aggregates formed in response to different types of stressors exhibit significant polarity differences. These results show that the solvatochromic fluorophores solely responsive to polarity represent a new class of indicators that can be widely used for detecting protein aggregation in live cells, thus paving the way for elucidating cellular mechanisms of protein aggregation as well as therapeutic approaches to managing intracellular aggregates.

19.
Nat Commun ; 13(1): 5434, 2022 09 16.
Article in English | MEDLINE | ID: mdl-36114189

ABSTRACT

Despite the great promise of genetic code expansion technology to modulate structures and functions of proteins, external addition of ncAAs is required in most cases and it often limits the utility of genetic code expansion technology, especially to noncanonical amino acids (ncAAs) with poor membrane internalization. Here, we report the creation of autonomous cells, both prokaryotic and eukaryotic, with the ability to biosynthesize and genetically encode sulfotyrosine (sTyr), an important protein post-translational modification with low membrane permeability. These engineered cells can produce site-specifically sulfated proteins at a higher yield than cells fed exogenously with the highest level of sTyr reported in the literature. We use these autonomous cells to prepare highly potent thrombin inhibitors with site-specific sulfation. By enhancing ncAA incorporation efficiency, this added ability of cells to biosynthesize ncAAs and genetically incorporate them into proteins greatly extends the utility of genetic code expansion methods.


Subject(s)
Genetic Code , Thrombin , Amino Acids/chemistry , Proteins/metabolism , Thrombin/genetics , Tyrosine/metabolism
20.
ACS Appl Mater Interfaces ; 14(38): 43421-43430, 2022 Sep 28.
Article in English | MEDLINE | ID: mdl-36121696

ABSTRACT

The development of wearable electronics has led to the growing demand for the self-powered and maintenance-free power sources. Under these circumstances, thermoelectric generators are considered promising candidates, which can directly convert body heat into electricity to power wearable electronics. However, most of the thermoelectric materials are either brittle or unrecoverable under external physical damage. It is urgent to develop thermoelectric materials that possess both stretchability and intrinsic self-healing property, and the remaining challenge is to combine the high mechanical robustness and excellent electrical conductivity. Herein, a self-healing and wearable all-organic thermoelectric composite is reported. The composite film exhibits high electrical conductivity of 238 S cm-1, high flexibility of up to 119% strain, and a maximum tensile strength of 23 MPa. When the composite film is subjected to external physical damage, most functionalities can be maintained after self-healing, 78% recovery in electrical conductivity, and 80% recovery in tensile strength. Using the self-healing composite, we fabricated a thermoelectric generator with a power output of 85.5 nW at a temperature difference of 48 K, which is a significant advance over the recently reported thermoelectric generators based on intrinsic self-healing thermoelectric materials. This work represents a crucial step toward achieving intrinsic self-healing all-organic thermoelectric materials with high electrical conductivity.

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