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1.
Artigo em Inglês | MEDLINE | ID: mdl-38826136

RESUMO

Per- and polyfluoroalkyl substances (PFAS) are a family of "forever chemicals" including PFOS (perfluorooctane sulfonate). These toxic chemicals do not break down in the environment nor in our bodies. In the human body, PFOS and PFOA (perfluoroctanoic acid) have a half-life (T1/2) of about 4-5 years so low daily consumption of these chemicals can accumulate in the human body to a harmful level over a long period. Although the use of PFOS in consumer products was banned in the U.S. in 2022/2023, this forever chemical remains detectable in our tap water and food products. Every American tested has a high level of PFAS in their blood (https://cleanwater.org/pfas-forever-chemicals). In this report, we used a Sertoli cell blood-testis barrier (BTB) model with primary Sertoli cells cultured in vitro with an established functional tight junction (TJ)-permeability barrier that mimicked the BTB in vivo. Treatment of Sertoli cells with PFOS was found to perturb the TJ-barrier, which was the result of cytoskeletal disruption across the cell cytoplasm, disrupting actin and microtubule polymerization. These changes thus affected the proper localization of BTB-associated proteins at the BTB. Using RNA-Seq transcriptome profiling, bioinformatics analysis, and pertinent biochemical and cell biology techniques, it was discovered that PFOS-induced Sertoli cell toxicity through the c-Jun N-terminal kinase (JNK; also known as stress-activated protein kinase, SAPK) and its phosphorylated/active form p-JNK signaling pathway. More importantly, KB-R7943 mesylate (KB), a JNK/p-JNK activator, was capable of blocking PFOS-induced Sertoli cell injury, supporting the notion that PFOS-induced cell injury can possibly be therapeutically managed.

2.
Anal Chem ; 96(18): 6930-6939, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38652001

RESUMO

Circulating tumor DNA (ctDNA) holds great promise as a noninvasive biomarker for cancer diagnosis, treatment, and prognosis. However, the accurate and specific quantification of low-abundance ctDNA in serum remains a significant challenge. This study introduced, for the first time, a novel exponential amplification reaction (EXPAR)-assisted CRISPR/Cas12a-mediated ratiometric dual-signal electrochemical biosensor for ultrasensitive and reliable detection of ctDNA. To implement the dual-signal strategy, a signal unit (ssDNA-MB@Fc/UiO-66-NH2) was prepared, consisting of methylene blue-modified ssDNA as the biogate to encapsulate ferrocene signal molecules within UiO-66-NH2 nanocarriers. The presence of target ctDNA KRAS triggered EXPAR amplification, generating numerous activators for Cas12a activation, resulting in the cleavage of ssDNA-P fully complementary to the ssDNA-MB biogate. Due to the inability to form a rigid structure dsDNA (ssDNA-MB/ssDNA-P), the separation of ssDNA-MB biogate from the UiO-66-NH2 surface was hindered by electrostatic interactions. Consequently, the supernatant collected after centrifugation exhibited either no or only a weak presence of Fc and MB signal molecules. Conversely, in the absence of the target ctDNA, the ssDNA-MB biogate was open, leading to the leakage of Fc signal molecules. This clever ratiometric strategy with Cas12a as the "connector", reflecting the concentration of ctDNA KRAS based on the ratio of the current intensities of the two electroactive signal molecules, enhanced detection sensitivity by at least 60-300 times compared to single-signal strategies. Moreover, this strategy demonstrated satisfactory performance in ctDNA detection in complex human serum, highlighting its potential for cancer diagnosis.


Assuntos
Técnicas Biossensoriais , DNA Tumoral Circulante , Técnicas Eletroquímicas , Humanos , DNA Tumoral Circulante/sangue , DNA Tumoral Circulante/genética , Sistemas CRISPR-Cas/genética , DNA de Cadeia Simples/química , Limite de Detecção , Endodesoxirribonucleases/química , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Associadas a CRISPR/química , Proteínas de Bactérias/química , Proteínas de Bactérias/genética
3.
Opt Express ; 32(6): 9397-9404, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38571175

RESUMO

This research proposed a novel pulse-shaping design for directly shaping distorted pulses after the amplification. Based on the principle of the design we made a pulse shaper. With this pulse shaper, we successfully manipulate the pulse's leading edge and width to achieve an 'M'-shaped waveform in an amplification system. Comparative experiments were conducted within this system to compare the output with and without the integration of the pulse shaper. The results show a significant suppression of the nonlinear effect upon adding the pulse shaper. This flexible and effective pulse shaper can be easily integrated into a high-power all-fiber system, supplying the capability to realize the desired output waveform and enhance the spectral quality.

4.
Opt Express ; 32(2): 2124-2131, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38297749

RESUMO

This paper provides a method to effectively suppress the severe ASE self-saturation when achieving high repetition frequency tunability with high output power and narrow pulse width in active Q-switched all-fiber lasers. By studying the regularity of the system's multi-stable state, we first ensured that the laser system operated in a steady state. Then output avoids uneven distribution of pulse energy or missing pulses due to period bifurcation state or chaos state. By adding multiple gain sub-rings within the cavity, the sub-ring structure itself indirectly mitigates the ASE self-saturation while smoothing the pulse. The method will avoid the severe power loss caused by traditional smoothing methods by adjusting the AOM rising edge time. It will also avoid lowering the ASE lasing threshold at high repetition frequency. Meanwhile, the intra-cavity backward ASE can be effectively absorbed by inserting the gain fiber in the sub-rings to directly mitigate the ASE self-saturation. The system's continuously adjustable repetition frequency can be as high as over 300 kHz. It ensures that output power above the watt level and a < 0.2 nm narrow bandwidth can be maintained while tuning the repetition frequency. The narrowest smoothing pulse width of 28 ns has been reached.

5.
Cytokine ; 173: 156415, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37952311

RESUMO

BACKGROUND: Endothelial nitric oxide (NO) produced by endothelial Nitric Oxide Synthase (eNOS) can promote the expression of pro-angiogenic cytokines and is favorable for angiogenesis. However, the relationship between NOS3 gene polymorphisms and genetic susceptibility to congenital heart disease (CHD) was still unclear. METHODS: We searched five databases including Pubmed, Cochrane Library, Embase, Web of Science, CNKI, and Wan Fang, to find all studies on NOS3 gene polymorphisms and CHD. Rstudio was used to merge the data included in the study to obtain OR, 95%CI, and forest plots. RESULTS: Five relevant literatures were included, including three sites of NOS3 gene, rs1799983 (G894T), rs2070744 (T-786C), and rs7830 (G10T). Several models including the homozygous model of rs1799983 (G894T) gene polymorphism (TT VS GG: OR = 1.602, 95%CI: 1.098 âˆ¼ 2.337, P = 0.027), rs7830 (G10T) gene polymorphism allele model (A VS C: OR = 1.171, 95%CI: 1.029 âˆ¼ 1.333, P = 0.017), homozygous model (AA VS CC: OR = 1.474, 95%CI: 1.122 âˆ¼ 1.936, P = 0.005) and implicit model (AA VS CC + AC: OR = 1.451, 95%CI: 1.133 âˆ¼ 1.859, P = 0.003) indicated that there was a correlation. The results of the combined analysis of each gene model of rs2070744 (T-786C) gene polymorphism sites were not statistically significant, and their P values were all>0.05. CONCLUSION: rs1799983 (G894T) and rs7830 (G10T) polymorphic sites might play a role in the susceptibility of sporadic congenital heart disease and increase the risk of CHD. Yet, it is still necessary to expand the sample size and conduct more prospective/retrospective studies to confirm whether the rs2070744 (T-786C) polymorphism tended to increase the incidence of CHD.


Assuntos
Cardiopatias Congênitas , Óxido Nítrico Sintase Tipo III , Humanos , Óxido Nítrico Sintase Tipo III/genética , Estudos Retrospectivos , Estudos Prospectivos , Polimorfismo Genético , Predisposição Genética para Doença , Estudos de Casos e Controles , Cardiopatias Congênitas/genética , Polimorfismo de Nucleotídeo Único/genética , Genótipo
6.
FASEB J ; 37(8): e23081, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37410071

RESUMO

Obstructive azoospermia (OA) accounts for approximately 40% of males who suffer from azoospermia of male infertility. Currently, available treatment for OA consists of reproductive tract surgical reconstruction and sperm retrieval from the testis. However, both treatments result in low fertility compared to normal pregnancy, and the main reason remains largely unknown. Previous studies have shown that the quality of sperm retrieved from OA patients is poor compared with normal adult males but without an in-depth study. Herein, we generated a mouse OA model with vasectomy to evaluate sperm quality systematically. Our results showed that the testis had normal spermatogenesis but increased apoptotic activity in both OA patients and mice. More importantly, epididymal morphology was abnormal, with swollen epididymal tubules and vacuole-like principal cells. Especially, sperm retrieved from the epididymis of OA mice showed poor motility and low fertilization ability in vitro. Using mass spectrometry in epididymal fluid, we found differences in the expression of key proteins for sperm maturation, such as Angiotensinogen (AGT), rhophilin-associated tail protein 1 (ROPN1), NPC intracellular cholesterol transporter 2 (NPC2), and prominin 1 (PROM1). Furthermore, our results demonstrated that AGT, secreted by epididymal principal cells, could regulate sperm motility by managing PKCα expression to modify sperm phosphorylation. In conclusion, our data evaluate sperm quality systematically in OA mice and contribute to the understanding between the sperm and epididymis, which may provide novel insight into treating male infertility.


Assuntos
Azoospermia , Infertilidade Masculina , Humanos , Gravidez , Feminino , Masculino , Animais , Camundongos , Epididimo , Azoospermia/terapia , Motilidade dos Espermatozoides , Sêmen , Testículo , Espermatozoides
7.
Org Biomol Chem ; 22(8): 1654-1661, 2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38295370

RESUMO

A detailed theoretical mechanistic investigation on chiral phosphoric acid (CPA)-catalyzed Paal-Knorr reactions, in the presence and absence of a Lewis acid, for the synthesis of N-N axially chiral atropisomers is described herein. Density functional theory (DFT) studies elucidate that in the absence of a Lewis acid, CPA catalyzes both the initial cyclization and the subsequent dehydroxylation processes, ambiguously identified as the rate-determining step in the reactions. Conversely, when a Lewis acid participates in the reaction, it facilitates the second dehydroxylation process with a significantly lower energy barrier, thereby reversing the rate-determining step to the initial cyclization step. It is noteworthy that in the case of N-aminoindoles, both the S-configurational transition state TS1 in the cyclization step and TS2 in the dehydroxylation process are favourable. In contrast, for the synthesis of a bispyrrole, the R-configurational TS1 and the S-configurational TS2 are dominant. Therefore, the enantiodivergence observed is essentially induced by the reversed rate-determining steps in the absence or presence of a Lewis acid in the case of a bispyrrole. Furthermore, the non-covalent interaction (NCI) and atoms-in-molecules (AIM) analysis of the TS structures reveal that the non-covalent interactions play a pivotal role in determining the enantiodivergence observed in these reactions.

8.
Cereb Cortex ; 33(11): 7148-7162, 2023 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-36813305

RESUMO

Studies have shown that spaceflight affects the emotional and social performance of astronauts. Identifying the neural mechanisms underlying the emotional and social effects of spacefaring-specific environments is essential to specify targeted treatment and prevention interventions. Repetitive transcranial magnetic stimulation (rTMS) has been shown to improve the neuronal excitability and is used to treat psychiatric disorders such as depression. To study the changes of excitatory neuron activity in medial prefrontal cortex (mPFC) in simulated space complex environment (SSCE), and to explore the role of rTMS in behavioral disorders caused by SSCE and the neural mechanism. We found that rTMS effectively ameliorated the emotional and social impairments of mice in SSCE, and acute rTMS could instantaneously enhance the excitability of mPFC neurons. During depression-like and social novelty behaviors, chronic rTMS enhanced the mPFC excitatory neuronal activity that was inhibited by SSCE. Above results suggested that rTMS can completely reverse the SSCE-induced mood and social impairment by enhancing the suppressed mPFC excitatory neuronal activity. It was further found that rTMS suppressed the SSCE-induced excessive dopamine D2 receptor expression, which may be the cellular mechanism by which rTMS potentiates the SSCE-evoked hypoactive mPFC excitatory neurons. Our current results raise the possibility of rTMS being applied as a novel neuromodulation for mental health protection in spaceflight.


Assuntos
Transtornos Mentais , Estimulação Magnética Transcraniana , Animais , Camundongos , Estimulação Magnética Transcraniana/métodos , Emoções , Córtex Pré-Frontal/fisiologia , Neurônios
9.
Ecotoxicol Environ Saf ; 279: 116502, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38788563

RESUMO

BACKGROUND: Despite the known reproductive toxicity induced by triptolide (TP) exposure, the regulatory mechanism underlying testicular vacuolization injury caused by TP remains largely obscure. METHODS: Male mice were subjected to TP at doses of 15, 30, and 60 µg/kg for 35 consecutive days. Primary Sertoli cells were isolated from 20-day-old rat testes and exposed to TP at concentrations of 0, 40, 80, 160, 320, and 640 nM. A Biotin tracer assay was conducted to assess the integrity of the blood-testis barrier (BTB). Transepithelial electrical resistance (TER) assays were employed to investigate BTB function in primary Sertoli cells. Histological structures of the testes and epididymides were stained with hematoxylin and eosin (H&E). The expression and localization of relevant proteins or pathways were assessed through Western blotting or immunofluorescence staining. RESULTS: TP exposure led to dose-dependent testicular injuries, characterized by a decreased organ coefficient, reduced sperm concentration, and the formation of vacuolization damage. Furthermore, TP exposure disrupted BTB integrity by reducing the expression levels of tight junction (TJ) proteins in the testes without affecting basal ectoplasmic specialization (basal ES) proteins. Through the TER assay, we identified that a TP concentration of 160 nM was optimal for elucidating BTB function in primary Sertoli cells, correlating with reductions in TJ protein expression. Moreover, TP exposure induced changes in the distribution of the BTB and cytoskeleton-associated proteins in primary Sertoli cells. By activating the AKT/mTOR signaling pathway, TP exposure disturbed the balance between mTORC1 and mTORC2, ultimately compromising BTB integrity in Sertoli cells. CONCLUSION: This investigation sheds light on the impacts of TP exposure on testes, elucidating the mechanism by which TP exposure leads to testicular vacuolization injury and offering valuable insights into comprehending the toxic effects of TP exposure on testes.


Assuntos
Barreira Hematotesticular , Citoesqueleto , Diterpenos , Compostos de Epóxi , Fenantrenos , Proteínas Proto-Oncogênicas c-akt , Células de Sertoli , Transdução de Sinais , Serina-Treonina Quinases TOR , Testículo , Masculino , Animais , Células de Sertoli/efeitos dos fármacos , Células de Sertoli/patologia , Diterpenos/toxicidade , Fenantrenos/toxicidade , Serina-Treonina Quinases TOR/metabolismo , Transdução de Sinais/efeitos dos fármacos , Testículo/efeitos dos fármacos , Testículo/patologia , Compostos de Epóxi/toxicidade , Proteínas Proto-Oncogênicas c-akt/metabolismo , Camundongos , Barreira Hematotesticular/efeitos dos fármacos , Barreira Hematotesticular/patologia , Citoesqueleto/efeitos dos fármacos , Ratos , Vacúolos/efeitos dos fármacos , Ratos Sprague-Dawley
10.
Int J Mol Sci ; 25(3)2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38338707

RESUMO

Acute colitis is a complex disease that can lead to dysregulation of the gut flora, inducing more complex parenteral diseases. Dandelion polysaccharides (DPSs) may have potential preventive and therapeutic effects on enteritis. In this study, LPS was used to induce enteritis and VC was used as a positive drug control to explore the preventive and therapeutic effects of DPS on enteritis. The results showed that DPS could repair the intestinal barrier, down-regulate the expression of TNF-α, IL-6, IL-1ß, and other pro-inflammatory factors, up-regulate the expression of IL-22 anti-inflammatory factor, improve the antioxidant capacity of the body, and improve the structure of intestinal flora. It is proved that DPS can effectively prevent and treat LPS-induced acute enteritis and play a positive role in promoting intestinal health.


Assuntos
Enterite , Microbioma Gastrointestinal , Taraxacum , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Lipopolissacarídeos , Polissacarídeos/farmacologia , Polissacarídeos/uso terapêutico , Inflamação
11.
Angew Chem Int Ed Engl ; 63(18): e202402020, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38385590

RESUMO

1,4-BN-doped polycyclic aromatic hydrocarbons (PAHs) have emerged as very promising emitters in organic light-emitting diodes (OLEDs) due to their narrowband emission spectra that may find application in high-definition displays. While considerable research has focused on investigating the properties of these materials, less attention has been placed on their synthetic methodology. Here we developed an efficient synthetic method for 1,4-BN-doped PAHs, which enables sustainable production of narrowband organic emitting materials. By strategically introducing substituents, such as methyl, tert-butyl, phenyl, and chloride, at the C5 position of the 1,3-benzenediamine substrates, we achieved remarkable regioselective borylation in the para-position of the substituted moiety. This approach facilitated the synthesis of a diverse range of 1,4-BN-doped PAHs emitters with good yields and exceptional regioselectivity. The synthetic method demonstrated excellent scalability for large-scale production and enabled late-stage transformation of the borylated products. Mechanistic investigations provided valuable insights into the pivotal roles of electron effect and steric hindrance effect in achieving highly efficient regioselective borylation. Moreover, the outstanding device performance of the synthesized compounds 10 b and 6 z, underscores the practicality and significance of the developed method.

12.
Anal Chem ; 95(32): 12122-12130, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37527175

RESUMO

Accurate detection of cancer-associated mRNAs is beneficial to early diagnosis and potential treatment of cancer. Herein, for the first time, we developed a novel CRISPR/Cas12a-powered electrochemical/fluorescent (EC/FL) dual-mode controlled-release homogeneous biosensor for mRNA detection. A functionalized ssDNA P2-capped Fe3O4-NH2 loaded with methylene blue (P2@MB-Fe3O4-NH2) was synthesized as the signal probe, while survivin mRNA was chosen as the target RNA. In the presence of the target mRNA, the nicking endonuclease-mediated rolling circle amplification (NEM-RCA) was triggered to produce significant amounts of ssDNA, activating the collateral activity of Cas12a toward the surrounding single-stranded DNA. Thus, the ssDNA P1 completely complementary to ssDNA P2 was cleaved, resulting in that the ssDNA P2 bio-gate on Fe3O4-NH2 could not be opened due to electrostatic interactions. As a result, there was no or only a little MB in the supernatant after magnetic separation, and the measured EC/FL signal was exceedingly weak. On the contrary, the ssDNA P2 bio-gate was opened, enabling MB to be released into the supernatant, and generating an obvious EC/FL signal. Benefiting from the accuracy of EC/FL dual-mode cross-verification, high amplification efficiency, high specificity of NEM-RCA and CRISPR/Cas12a, and high loading of mesoporous Fe3O4-NH2 on signal molecules, the strategy shows aM-level sensitivity and single-base mismatch specificity. More importantly, the practical applicability of this dual-mode strategy was confirmed by mRNA quantification in complex serum environments and tumor cell lysates, providing a new way for developing a powerful disease diagnosis tool.


Assuntos
Técnicas Biossensoriais , Sistemas CRISPR-Cas , Sistemas CRISPR-Cas/genética , Preparações de Ação Retardada , RNA Mensageiro/genética , RNA , Corantes , DNA de Cadeia Simples/genética , Endonucleases , Inibidores de Serina Proteinase
13.
BMC Plant Biol ; 23(1): 127, 2023 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-36882682

RESUMO

BACKGROUND: WRINKLED1 (WRI1) encodes a transcription factor, belonging to the APETALA2 (AP2) family, and plays a key role in regulating plant oil biosynthesis. As a newly woody oil crop, tree peony (Paeonia rockii) was notable for the abundant unsaturated fatty acids in its seed oil. However, the role of WRI1 during the accumulation of P. rockii seeds oil remains largely unknown. RESULTS: In this study, a new member of the WRI1 family was isolated from P. rockii and was named PrWRI1. The ORF of PrWRI1 consisted of 1269 nucleotides, encoding a putative protein of 422 amino acids, and was highly expressed in immature seeds. Subcellular localization analysis in onion inner epidermal cells showed that PrWRI1 was located at the nucleolus. Ectopic overexpression of PrWRI1 could significantly increase the total fatty acid content in Nicotiana benthamiana leaf tissue and even PUFAs in transgenic Arabidopsis thaliana seeds. Furthermore, the transcript levels of most genes related to fatty acids (FA) synthesis and triacylglycerol (TAG) assembly were also up-regulated in transgenic Arabidopsis seeds. CONCLUSIONS: Together, PrWRI1 could push carbon flow to FA biosynthesis and further enhance the TAG amount in seeds with a high proportion of PUFAs.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Paeonia , Fatores de Transcrição/genética , Paeonia/genética , Regulação da Expressão Gênica , Aminoácidos , Arabidopsis/genética , Óleos de Plantas
14.
Appl Environ Microbiol ; 89(9): e0053323, 2023 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-37565764

RESUMO

Antibiotic resistance is a major global health crisis facing humanity, with horizontal gene transfer (HGT) as a principal dissemination mechanism in the natural and clinical environments. Perfluoroalkyl substances (PFASs) are emerging contaminants of global concern due to their high persistence in the environment and adverse effects on humans. However, it is unknown whether PFASs affect the HGT of bacterial antibiotic resistance. Using a genetically engineered Escherichia coli MG1655 as the donor of plasmid-encoded antibiotic resistance genes (ARGs), E. coli J53 and soil bacterial community as two different recipients, this study demonstrated that the conjugation frequency of ARGs between two E. coli strains was (1.45 ± 0.17) × 10-5 and perfluorooctane sulfonate (PFOS) at environmentally relevant concentrations (2-50 µg L-1) increased conjugation transfer between E. coli strains by up to 3.25-fold. Increases in reactive oxygen species production, cell membrane permeability, biofilm formation capacity, and cell contact in two E. coli strains were proposed as major promotion mechanisms from PFOS exposure. Weighted gene co-expression network analysis of transcriptome data identified a series of candidate genes whose expression changes could contribute to the increase in conjugation transfer induced by PFOS. Furthermore, PFOS also generally increased the ARG transfer into the studied soil bacterial community, although the uptake ability of different community members of the plasmid either increased or decreased upon PFOS exposure depending on specific bacterial taxa. Overall, this study reveals an unrecognized risk of PFOS in accelerating the dissemination of antibiotic resistance. IMPORTANCE Perfluoroalkyl substances (PFASs) are emerging contaminants of global concern due to their high persistence in the environment and adverse health effects. Although the influence of environmental pollutants on the spread of antibiotic resistance, one of the biggest threats to global health, has attracted increasing attention in recent years, it is unknown whether environmental residues of PFASs affect the dissemination of bacterial antibiotic resistance. Considering PFASs, often called "forever" compounds, have significantly higher environmental persistence than most emerging organic contaminants, exploring the effect of PFASs on the spread of antibiotic resistance is more environmentally relevant and has essential ecological and health significance. By systematically examining the influence of perfluorooctane sulfonate on the antibiotic resistance gene conjugative transfer, not only at the single-strain level but also at the community level, this study has uncovered an unrecognized risk of PFASs in promoting conjugative transfers of bacterial antibiotic resistance genes, which could be incorporated into the risk assessment framework of PFASs.


Assuntos
Escherichia coli , Fluorocarbonos , Humanos , Escherichia coli/genética , Farmacorresistência Bacteriana/genética , Fluorocarbonos/farmacologia , Bactérias/genética , Antibacterianos/farmacologia , Solo , Genes Bacterianos , Plasmídeos/genética , Transferência Genética Horizontal
15.
Opt Express ; 31(26): 43125-43134, 2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-38178414

RESUMO

We demonstrate a single-stage all-fiber nanosecond amplifier with a total average power of greater than 1.4 kW by employing what we believe to be a novel multi-cavity passively Q-switched fiber laser as the seed laser. The multi-cavity seed laser adopts a piece of Yb-doped fiber (YDF) as saturable absorber (SA), and it includes two external cavities resonating at 1030 nm and an internal cavity working at 1064 nm, respectively. Using such a scheme, a stable dual-channel laser output with a total average power of >35 W, a pulse width of 45 ns, and an optical conversion efficiency of 72% operating at 1064 nm is achieved. By power scaling the multi-cavity seed laser, a dual-channel single-stage nanosecond amplifier is obtained with a single-port average power of exceeding 700 W and a pulse energy of about 7.3 mJ. To the best of our knowledge, this work is the highest average power and optical conversion efficiency for passively Q-switched all-fiber laser employing SA fiber, and the highest average power for a single-stage all-fiber nanosecond amplifier.

16.
Opt Express ; 31(10): 16845-16856, 2023 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-37157754

RESUMO

This paper presents a comprehensive experimental study of multi-stable-state output characteristics in an all-fiber laser with an acoustic-optical modulator (AOM) as the Q-switcher. For the first time, in this structure, the partitioning of the pulsed output characteristics is explored, dividing the operating status of the laser system into four zones. The output characteristics, the application prospects, and the parameter setting rules for working in stable zones are presented. In the second stable zone, a peak power of 4.68 kW with 24 ns was obtained at 10 kHz. This is the narrowest pulse duration achieved with an AOM actively Q-switched all-fiber linear structure. The pulse narrowing is attributed to the rapid release of signal power and pulse tail truncated by AOM shutdown.

17.
Cytokine ; 161: 156056, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36240721

RESUMO

BACKGROUND: The mortality rate of patients with sepsis has been increasing in recent years. Alterations of biomarkers levels during treatment are important in evaluating treatment efficacy and predicting outcomes in sepsis. This meta-analysis investigated the relationship between changes in cytokine levels after treatment compared with those on hospital admission, and their relationship with the prognosis of patients with sepsis. METHODS: From conception until August 4, 2021, a complete literature search of the PubMed, Web of Science, and Cochrane Library electronic databases was done. Observational studies where the outcomes of sepsis patients were divided into non-survivors and survivors and which reported cytokine levels at least before treatment in ICU were included in the current study. Standardized mean difference (SMD) with 95% confidence intervals (CI) values from individual studies were pooled using a random-effects model. Quality assessment, subgroup analysis, publication bias, and sensitivity analyses were all carried out. RESULTS: A total of 2570 patients with sepsis from 25 eligible studies were included, and 14 of them measured the cytokine levels before and after treatment in ICU. Among IL-6, TNF-α, IL-1ß and IL-10 levels, those of IL-6 were significantly lower after treatment in ICU than at baseline in patients with sepsis in the survival group (SMD = -0.69, P < 0.0001), but were comparable in the non-survival group (SMD = -0.99, P = 0.0575). Similarly, post-treatment TNF-α levels were significantly lower than those at baseline only in patients with sepsis in the survival group (SMD = -0.44, P < 0.0001), but not in the non-survival group (SMD =-0.17, P = 0.0842). CONCLUSION: This meta-analysis shows that reduced IL-6 and TNF-α levels after sepsis treatment in ICU may be indicators of better prognosis and survival of patients with sepsis.


Assuntos
Citocinas , Sepse , Humanos , Fator de Necrose Tumoral alfa , Interleucina-6 , Sepse/terapia , Biomarcadores
18.
Langmuir ; 39(40): 14451-14458, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37773886

RESUMO

Polyamines have emerged as a promising class of CO2 absorbents due to their remarkable sequestration capacity. However, their potential industrial application as aqueous absorbents is significantly hindered by a low regeneration efficiency and high energy consumption. To address these issues, this study investigates the use of triethylenetetramine (TETA) and ethylene glycol (EG) to develop a nonaqueous absorbent. The incorporation of EG enhances absorption performance and reduces the regeneration energy needed for TETA, whereas the high viscosity of the absorbent impedes absorption rate, amine efficiency, and regeneration efficiency. In order to enhance CO2 capture, micron-sized reaction units (SiO2@TETA-EG) were developed by encapsulating TETA solution with nanosilica. The SiO2@TETA-EG composite exhibits a large specific surface area (99 m2/g), with a porous shell structure and improved fluidity, which effectively counteracts the negative effects caused by high viscosity. Notably, SiO2@TETA-EG indicates a noticeably higher apparent rate constant of 4.29 min-1 at 323.2 K compared to the TETA-EG solution. Furthermore, SiO2@TETA-EG displays a 28.4% boost in regeneration efficiency while maintaining favorable stability in pore size and shape after regeneration.

19.
J Nanobiotechnology ; 21(1): 72, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36859296

RESUMO

BACKGROUND: The development of multidrug resistance (MDR) during postoperative chemotherapy for colorectal cancer substantially reduces therapeutic efficacy. Nanostructured drug delivery systems (NDDSs) with modifiable chemical properties are considered promising candidates as therapies for reversing MDR in colorectal cancer cells. Selenium-doped manganese phosphate (Se-MnP) nanoparticles (NPs) that can reverse drug resistance through sustained release of selenium have the potential to improve the chemotherapy effect of colorectal cancer. RESULTS: Se-MnP NPs had an organic-inorganic hybrid composition and were assembled from smaller-scale nanoclusters. Se-MnP NPs induced excessive ROS production via Se-mediated activation of the STAT3/JNK pathway and a Fenton-like reaction due to the presence of manganese ions (Mn2+). Moreover, in vitro and in vivo studies demonstrated Se-MnP NPs were effective drug carriers of oxaliplatin (OX) and reversed multidrug resistance and induced caspase-mediated apoptosis in colorectal cancer cells. OX@Se-MnP NPs reversed MDR in colorectal cancer by down-regulating the expression of MDR-related ABC (ATP binding cassette) transporters proteins (e.g., ABCB1, ABCC1 and ABCG2). Finally, in vivo studies demonstrated that OX-loaded Se-MnP NPs significantly inhibited proliferation of OX-resistant HCT116 (HCT116/DR) tumor cells in nude mice. CONCLUSIONS: OX@Se-MnP NPs with simple preparation and biomimetic chemical properties represent promising candidates for the treatment of colorectal cancer with MDR.


Assuntos
Neoplasias Colorretais , Selênio , Animais , Camundongos , Catálise , Portadores de Fármacos , Camundongos Nus , Humanos , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos
20.
Appl Opt ; 62(9): 2357-2366, 2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-37132875

RESUMO

This paper focuses on the rapid charge transfer of lock-in pixels in time of flight 3D image sensors. Through the principal analysis, a mathematical model of potential distribution in a pinned photodiode (PPD) in different comb shapes is established. Based on this model, the influence of different comb shapes on the accelerating electric field in PPD is analyzed. The semiconductor device simulation tool SPECTRA is applied to verify the effectiveness of the model, and the simulation results are analyzed and discussed. When the width of comb tooth is in narrow and medium range, the potential changes more obviously with the increase of comb tooth angle α, whereas the potential becomes stable even if the comb tooth angle α increases sharply with the wide comb tooth width. The proposed mathematical model contributes to instructing the design of pixel transferring electrons rapidly and resolving image lag.

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