Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 116
Filtrar
1.
Anal Bioanal Chem ; 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-35001192

RESUMO

Telomerase is considered a valuable diagnostic and prognostic cancer biomarker. Accurate and reliable detection of telomerase activity is of great value in clinical diagnosis, screening of inhibitors, and therapeutics. Here, we developed a novel amplified fluorescence resonance energy transfer (FRET) nanoprobe for highly sensitive and reliable monitoring of intracellular telomerase activity. The nanoprobe (QDSA@DNA) was composed of a streptavidin-modified quantum dot (QDSA) which was functionalized with a telomerase primer sequence (TP) and Cy5-tagged signal switching sequence (SS) through biotin-streptavidin interaction. When the nanoprobe was assembled, the Cy5 was in close proximity to the QDSA, resulting in high FRET efficiency from the QDSA to Cy5. In the presence of telomerase, the TP could be extended to produce telomeric repeat units, which was complementary to the loop of SS. Thus, the SS could hybridize with elongated sequences to form a rigid double-stranded structure, which forced the Cy5 away from the surface of the QDSA, causing low FRET efficiency. Furthermore, due to the production of multiple repeat units by telomerase, multiple hairpin structures could be opened, yielding significant fluorescence ratio (FQDsa/FCy5) enhancement for sensing of telomerase activity. In this way, the combination of a FRET and target-assisted strategy in a nanoprobe improved the detection accuracy and amplified the detection signal, respectively. The QDSA@DNA nanoprobe also showed high selectivity, excellent nuclease stability, and good biocompatibility. More importantly, this nanoprobe was found to be an excellent platform for efficient monitoring of intracellular telomerase activity, providing a potential platform in tumor diagnosis and screening of telomerase-related inhibitors.

2.
Chemosphere ; 289: 133260, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34906524

RESUMO

A novel chelating flocculant with branched architectures, polyacrylamide grafted maleoyl chitosan-mercaptoacetic acid (PAM-g-M(CS-MA)), was successfully fabricated using maleic anhydride as the "bridge" between chitosan and polyacrylamide. The functional groups and structural characteristic information of copolymers were obtained via characterization analysis. Flocculation performance was systematically investigated via purifying a series of simulated wastewater containing Cu or Cd. The properties of the flocs were studied to give in-depth evidences for the role of chelation groups and branched architectures in flocculation. Results indicated that PAM-g-M(CS-MA) showed excellent flocculation capacity for heavy metals in high concentrations and was superior to other chelating flocculants. The maximum flocculation efficiency of Cu (93.90%) and Cd (92.47%) was achieved by PAM-g-M(CS-MA) at pH 7, dosage of 100 mg L-1 and stirring speed of 90 rpm. The flocculation mechanisms of PAM-g-M(CS-MA) were deeply explored through the analyses of floc properties. The strong synergistic chelation of mercapto, carboxyl, amide and hydroxyl groups predominated for the capturing of heavy metals; and the branched architectures facilitated the formation of large and stable flocs via adsorption and bridging-furl effect. This study provided a solid foundation for the fabrication of flocculants for heavy metal wastewater treatment.


Assuntos
Metais Pesados , Purificação da Água , Quelantes , Floculação , Águas Residuárias
3.
J Am Chem Soc ; 144(1): 163-173, 2022 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-34963281

RESUMO

The transformational effect of photoredox catalytic chemistries has inspired new opportunities, enabling us to interrogate nature in ways that are not possible otherwise and to unveil new biotechnologies in therapy and diagnosis. However, the deployment of artificial photoredox catalysis in living systems remains challenging, mired by the off-target risk and safety concerns of photocatalyst toxicity. Here, we present an appealing approach, namely conditionally activatable photoredox catalysis (ConAPC), and as a proof of concept design the first ConAPC architecture (Se-NO2) based upon classic self-immolative chemistry, in which the inherent photocatalytic properties can be temporarily caged while the species becomes active only at the tumor sites via sensing to specific biomarkers. Such a masking strategy allows a spatial-temporal control of photoresponsivity in vitro and in vivo. In particular, for ConAPC design, a new biologically benign metal-free photocatalyst (Se-NH2), which is able to initiate NIR photoredox catalysis to manipulate the cellular electron pool in an O2-independent mechanism of action, is identified. With this unique strategy, potent tumor-specific targeting photocatalytic eradication (TGI: 95%) is obtained in a mouse model. Impressively, favorable features such as high-resolution tumor recognition (SBR: 33.6) and excellent biocompatibility and safety are also achieved. This work therefore offers a new possibility for chemists to leverage artificial photocatalytic reactions toward the development of facile and intelligent photocatalytic theranostics.

4.
Bioact Mater ; 10: 1-14, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34901525

RESUMO

Bone defects remain a major threat to human health and bone tissue regeneration has become a prominent clinical demand worldwide. The combination of microRNA (miRNA) therapy with 3D printed scaffolds has always posed a challenge. It can mimic physiological bone healing processes, in which a biodegradable scaffold is gradually replaced by neo-tissue, and the sustained release of miRNA plays a vital role in creating an optimal osteogenic microenvironment, thus achieving promising bone repair outcomes. However, the balance between two key factors - scaffold degradation behavior and miRNA release profile - on osteogenesis and bone formation is still poorly understood. Herein, we construct a series of miRNA-activated hydrogel scaffolds (MAHSs) generated by 3D printing with different crosslinking degree to screened the interplay between scaffold degradation and miRNA release in the osteoinduction activity both in vitro and in vivo. Although MAHSs with a lower crosslinking degree (MAHS-0 and MAHS-0.25) released a higher amount of miR-29b in a sustained release profile, they degraded too fast to provide prolonged support for cell and tissue ingrowth. On the contrary, although the slow degradation of MAHSs with a higher crosslinking degree (MAHS-1 and MAHS-2.5) led to insufficient release of miR-29b, their adaptable degradation rate endowed them with more efficient osteoinductive behavior over the long term. MAHS-1 gave the most well-matched degradation rate and miR-29b release characteristics and was identified as the preferred MAHSs for accelerated bone regeneration. This study suggests that the bio-adaptable balance between scaffold degradation behavior and bioactive factors release profile plays a critical role in bone regeneration. These findings will provide a valuable reference about designing miRNAs as well as other bioactive molecules activated scaffold for tissue regeneration.

5.
Aging (Albany NY) ; 13(23): 25440-25452, 2021 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-34904960

RESUMO

As one of the most commonly used nanoparticles, titanium dioxide nanoparticles (TiO2-NPs) are widely used as coating reagents in cosmetics, medicine and other industries. The increasing risk of exposure to TiO2-NPs raises concerns about their safety. In this study, we investigated the mechanism by which TiO2-NPs cross the blood-testis barrier (BTB). TM-4 cells were selected as an in vitro Sertoli cell model of BTB. Cell viability, cell morphological changes, apoptosis, oxidative damage, and the expression levels of actin regulatory and tight junction (TJ) proteins were assessed in TM-4 cells treated with 3-nm and 24-nm TiO2-NPs. Cells treated with 3-nm TiO2-NPs exhibited increased cytotoxicity and decreased Annexin II expression, whereas cells treated with 24-nm TiO2-NPs exhibited increased Arp 3 and c-Src expression. Both TiO2-NPs induced significant oxidative stress, decreased the expression of TJ proteins (occludin, ZO-1 and claudin 5), damaged the TJ structure, and exhibited enlarged gaps between TM-4 cells. Our results indicated that both TiO2-NPs crossed the BTB by disrupting actin-based adhesive junctions of TM-4 cells; however, apoptosis was not observed. Our results provide new insights into how TiO2-NPs cross the BTB.

6.
Front Pharmacol ; 12: 770663, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34938186

RESUMO

Platinum (Pt) derivatives such as cisplatin and carboplatin are the class of drugs with proven activity against triple-negative breast cancer (TNBC). This is due to the ability of Pt compounds to interfere with the DNA repair mechanisms of the neoplastic cells. Taxanes have been efficacious against estrogen receptor-negative tumors and act by disruption of microtubule function. Due to their distinct mechanisms of action and routes of metabolism, the combination of the Pt agents and taxanes results in reduced systemic toxicity, which is ideal for treating TNBC. Also, the sensitivity of BRCA1-mutated cells to taxanes remains unsolved as in vitro evidence indicates resistance against taxanes due to BRCA1 mutations. Recent evidence suggests that the combination of carboplatin and paclitaxel resulted in better pathological complete response (pCR) in patients with TNBC, both in neoadjuvant and adjuvant settings. In vitro studies showed sequential dependency and optimal time scheduling of Pt- and taxane-based chemotherapy. Also, combining carboplatin with docetaxel in the NAC regimen yields an excellent pCR in patients with BRCA-associated and wild-type TNBC. TNBC is a therapeutic challenge that can be tackled by identifying new therapeutic sub-targets and specific cross-sections that can be benefitted from the addition of Pt- and taxane-based chemotherapy. This review summarizes the merits as well as the mechanism of Pt- and taxane-based adjuvant and neoadjuvant chemotherapies in early TNBC from the available and ongoing clinical studies.

7.
Crit Rev Food Sci Nutr ; : 1-34, 2021 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-34845950

RESUMO

Different parts of lotus (Nelumbo nucifera Gaertn.) including the seeds, rhizomes, leaves, and flowers, are used for medicinal purposes with health promoting and illness preventing benefits. The presence of active chemicals such as alkaloids, phenolic acids, flavonoids, and terpenoids (particularly alkaloids) may account for this plant's pharmacological effects. In this review, we provide a comprehensive overview and summarize up-to-date research on the biosynthesis, pharmacokinetics, and bioactivity of lotus alkaloids as well as their safety. Moreover, the potential uses of lotus alkaloids in the food, pharmaceutical, and cosmetic sectors are explored. Current evidence shows that alkaloids, mainly consisting of aporphines, 1-benzylisoquinolines, and bisbenzylisoquinolines, are present in different parts of lotus. The bioavailability of these alkaloids is relatively low in vivo but can be enhanced by technological modification using nanoliposomes, liposomes, microcapsules, and emulsions. Available data highlights their therapeutic and preventive effects on obesity, diabetes, neurodegeneration, cancer, cardiovascular disease, etc. Additionally, industrial applications of lotus alkaloids include their use as food, medical, and cosmetic ingredients in tea, other beverages, and healthcare products; as lipid-lowering, anticancer, and antipsychotic drugs; and in facial masks, toothpastes, and shower gels. However, their clinical efficacy and safety remains unclear; hence, larger and longer human trials are needed to achieve their safe and effective use with minimal side effects.

8.
J Nanobiotechnology ; 19(1): 383, 2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34809612

RESUMO

Serious infection caused by drug-resistant gram-negative bacteria and their secreted toxins (e.g., lipopolysaccharide) is a serious threat to human health. Thus, treatment strategies that efficiently kill bacteria and reducing the impact of their toxins simultaneously are urgently required. Herein, a novel antibacterial platform composed of a mesoporous copper silicate microsphere (CSO) core and a platelet membrane (PM) shell was prepared (CSO@PM). CSO@PM specifically targets bacteria owing to formyl peptide receptors on the PM and, combined with photothermal therapy (PTT), exhibits highly effective bacter icidal activity. Importantly, CSO@PM can adsorb lipopolysaccharide secreted by gram-negative bacteria, resulting in inflammation reduction. Thus, CSO@PM stimulates re-epithelialization and granulation-tissue formation, promoting wound healing. Moreover, this antibacterial platform exhibits no obvious toxicity at all the test concentrations in vitro and in vivo. Thus, CSO@PM exhibits a robust antibacterial effect and a strong toxin-adsorption capacity, facilitating the clinical treatment of many bacterial infections and the development of next-generation antibacterial nanoagents.

9.
Am J Transl Res ; 13(9): 10388-10395, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34650707

RESUMO

OBJECTIVE: The effects of butylphthalide on serum C-reactive protein (CRP), Parkinson disease protein 7 (PARK7), and neurotrophin-3 (NT-3) levels, and neurological function in patients with acute cerebral infarction (ACI) were explored in order to provide a reference for clinical treatment of the disease. METHODS: One hundred and twenty patients with ACI treated in our hospital from September 2016 to June 2018 were selected and randomized into the control group and the study group, with 60 cases in each group. Patients in the control group were treated with conventional therapy, while those in the study group were treated with butylphthalide. Clinical efficacy, serum levels of CRP, PARK7, and NT-3, as well as the scores of National Institutes of Health Stroke Scale (NIHSS), Fugl-Meyer Assessment (FMA), and Barthel Index (BI) before and 2 months after treatment were analyzed and compared between the two groups. RESULTS: The study group had a significantly higher effective rate (93.33%) than the control group (73.33%; P<0.05). Before treatment, differences in serum CRP, PARK7, NT-3, IL-6, IL-8, and IL-10 levels between the study group and the control group were barely notable (P>0.05). After treatment, the study group observed lower serum levels of CRP, PARK7, IL-6, IL-8, and a higher levels of IL-10, NT-3 in comparison with those of the control group (P<0.05). Before treatment, NIHSS, FMA, and BI scores between the two groups did not show significant differences (P>0.05). After treatment, the study group yielded a remarkably lower NIHSS score and higher FMA and BI scores than the control group (P<0.05). CONCLUSION: Butylphthalide is effective in the treatment of ACI. It can effectively facilitate the recovery of neurological and motor functions of patients, enhance their quality of life and improve serum CRP, PARK7, and NT-3 levels, which is worthy of clinical promotion.

10.
Front Endocrinol (Lausanne) ; 12: 712513, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34566889

RESUMO

The improvement in the quality of life is accompanied by an accelerated pace of living and increased work-related pressures. Recent decades has seen an increase in the proportion of obese patients, as well as an increase in the prevalence of breast cancer. More and more evidences prove that obesity may be one of a prognostic impact factor in patients with breast cancer. Obesity presents unique diagnostic and therapeutic challenges in the population of breast cancer patients. Therefore, it is essential to have a better understanding of the relationship between obesity and breast cancer. This study aims to construct a prognostic risk prediction model combining obesity and breast cancer. In this study, we obtained a breast cancer sample dataset from the GEO database containing obesity data [determined by the body mass index (BMI)]. A total of 1174 genes that were differentially expressed between breast cancer samples of patients with and without obesity were screened by the rank-sum test. After weighted gene co-expression network analysis (WGCNA), 791 related genes were further screened. Relying on single-factor COX regression analysis to screen the candidate genes to 30, these 30 genes and another set of TCGA data were intersected to obtain 24 common genes. Finally, lasso regression analysis was performed on 24 genes, and a breast cancer prognostic risk prediction model containing 6 related genes was obtained. The model was also found to be related to the infiltration of immune cells. This study provides a new and accurate prognostic model for predicting the survival of breast cancer patients with obesity.

11.
Eye (Lond) ; 2021 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-34385698

RESUMO

OBJECTIVES: To evaluate the association between serum retinol concentration and normal-tension glaucoma (NTG). METHODS: A total of 345 study subjects were recruited in a prospective cross-sectional study: 101 patients with NTG, 106 patients with high-pressure primary open-angle glaucoma (POAG) and 138 healthy control subjects. Serum retinol concentration in fasting blood samples was determined by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). All study subjects were given complete ophthalmic examinations and diagnosed by two glaucoma sub-specialists. RESULTS: Serum retinol concentrations in NTG, POAG, and controls were 338.90 ± 103.23 ng/mL, 405.22 ± 114.12 ng/mL, and 408.84 ± 122.36 ng/mL respectively. NTG patients had lower serum retinol concentrations than POAG (p < 0.001) or healthy controls (p < 0.001). There was no statistical difference between the POAG and healthy controls (p = 0.780). Higher proportion of NTG patients (37.6%) than POAG (17.9%) or controls (21.7%) had serum retinol concentrations lower than 300 ng/mL. Serum retinol was positively correlated with optic nerve sheath diameter (ONSD) (r = 0.349, p = 0.001) in glaucoma patients and not associated with any other demographic features or ophthalmic biometric parameters in the NTG patients. Multivariate logistic regression showed that serum retinol (OR = 0.898, 95CI%: 0.851-0.947) was associated with incident NTG. CONCLUSIONS: NTG patients had lower serum retinol concentrations. Serum retinol uniquely associated with NTG makes it a new potential option for the diagnosis and treatment of the disease.

12.
Gland Surg ; 10(7): 2255-2265, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34422596

RESUMO

Background: Dual-targeted therapy is currently the standard adjuvant treatment for human epidermal growth factor receptor 2-positive (HER2+) and lymph node-positive (LN+) breast cancer. However, the optimal therapeutic strategy for patients with HER2+ and lymph node-negative (LN-) breast cancer remains unclear. This population-based study aimed to explore the factors associated with survival in patients with HER2+ and LN- breast cancer, and develop a survival-predicting nomogram in the era of trastuzumab-based single-targeted therapy. Methods: We collected the clinicopathological information of HER2+ and LN- breast cancer patients who underwent chemotherapy and surgery from The Surveillance, Epidemiology, and End Results (SEER) database (2010-2016, the Trastuzumab-based single-targeted therapy era). We subsequently explored the risk factors for breast cancer-specific survival (BCSS) and overall survival (OS) using a Cox proportional hazards regression model, aiming to identify subgroups with worse prognosis, which would indicate potential demand for dual-targeted therapy. Three- and 5-year survival probability-predictive nomograms were established and subjected to bootstrap internal validation. The concordance index (C-index) and calibration curve were applied to evaluate the performance of the model. Results: After data cleansing, a total of 13,755 patients were included in the current analysis. Using univariate and multivariate Cox proportional hazards regression, higher clinical T stage, hormone receptors-negative (HR-), and partial mastectomy without radiotherapy were identified as independent risk factors for BCSS and OS in patients with HER2+ and LN- breast cancer. Nomograms for 3- and 5-year BCSS and OS incorporating the selected prognostic factors were established. Calibration curves verified good consistency between the actual and nomogram-predicted survival probability. The C-index values of the BCSS and OS predictions and 95% confidence interval (CI) were 0.773 (0.740-0.806) and 0.764 (0.737-0.791), respectively. Conclusions: Higher clinical T stage, HR-, and partial mastectomy without radiotherapy predicted worse prognosis in patients with HER2+ and LN- breast cancer. In clinical practice, patients can be recommended for single-targeted or dual-targeted therapy according to the individualized factors.

13.
Graefes Arch Clin Exp Ophthalmol ; 259(9): 2813-2820, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34287693

RESUMO

PURPOSE: To determine myopia progression in children during the COVID-19 and the related factors associated with myopia. METHODS: All subjects underwent three-timepoint ocular examinations that were measured in July 2019, January, and August 2020. We compared the changes in uncorrected visual acuity (UCVA), mydriatic spherical equivalent (SE), and axial length (AL) between two periods (before and during COVID-19). A questionnaire was performed to investigate risk factors for myopia. RESULTS: Compared with before the COVID-19, the mean (S.D.) myopia progression during the COVID-19 was significantly higher in right eyes (- 0.93 (0.65) vs. - 0.33 (0.47) D; p < 0.001). However, the differences in UCVA changes and the axial elongation between two periods were clinically insignificant. Through logistic regressive analysis, we found the difference of the SE changes was associated with the baseline AL (P = 0.028; 95% confidence interval [CI], 1.058, 2.632), online education (P = 0.02; 95% CI, 1.587, 8.665), and time of digital screen (p < 0.005; 95% CI, 1.587, 4.450). CONCLUSIONS: Children were at higher risk of myopia progression during COVID-19, which was associated with the baseline AL, the longtime online learning, and digital screen reading.


Assuntos
COVID-19 , Miopia , Criança , China/epidemiologia , Progressão da Doença , Humanos , Miopia/diagnóstico , Miopia/epidemiologia , Pandemias , Refração Ocular , SARS-CoV-2
14.
J Org Chem ; 86(15): 10118-10128, 2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34213904

RESUMO

We have developed an efficient formylation of pyrroloisoquinolines using bromoisobutyrate and dimethyl sulfoxide as carbonyl reagent. Various formylated pyrroloisoquinolines could be prepared in good yields (up to 94%). This formylation process can be easily scaled up to gram scale with good yield. In most cases of pyrroloisoquinolines without methoxy groups, the combination of bromoisobutyrate and dimethyl sulfoxide could act as a bromination reagent, delivering brominated pyrroloisoquinolines in acceptable to good yields (up to 82%).

15.
Artigo em Inglês | MEDLINE | ID: mdl-34204658

RESUMO

The difference in glacier surface elevation is a sensitive indicator of climate change and is also important for disaster warning and water supply. In this paper, 25 glaciers on Bogda Mountain, in the eastern Tianshan Mountains, are selected as the study object as they are typical of glaciers in arid or semi-arid areas with importance for water supply. The Repeat Orbit Interferometry (ROI) method is used to survey the surface elevation of these glaciers using Sentinel-1A Radar data from 2017. Using data from the Shuttle Radar Topography Mission (SRTM) and a Digital Elevation Model (DEM), the difference in the glacier surface elevation between 2000 and 2017 is obtained. A scheme to evaluate the accuracy of estimated variations in glacier surface elevation is proposed in this article. By considering the surfaces of lakes in the study region as ideal horizontal planes, the average standard deviation (SD) value of the lake elevation is taken as the error caused by the radar sensor and observing conditions. The SD of the lake elevation is used as an index to evaluate the error in the estimated variation of the glacier surface elevation, and the obtained SD values indicate that the result obtained using the ROI method is reliable. Additionally, the glacier surface elevation variation pattern and a Logarithmic Fitting Model (LFM) are used to reduce the error in high-altitude glacial accumulation areas to improve the estimation of the difference in the glacier surface elevation obtained using ROI. The average SD of the elevation of the 12 lakes is ±2.87 m, which shows that the obtained glacier surface elevations are reliable. This article concludes that, between 2000 and 2017, the surface elevation of glaciers on Bogda Mountain decreased by an average of 11.6 ± 1.3 m, corresponding to an average decrease rate of 0.68 m/a, and glaciers volume decreased by an average of 0.504 km3. Meanwhile, the surface elevations of the lakes increased by an average of 8.16 m. The decrease of glacier surface elevation leads to the expansion of glacial lakes. From the north slope clockwise to the south slope, the glacier elevation variation showed a decreasing trend, and the elevation variation gradually increased from the south slope to the north slope. With the increase of glacier altitude, the variation of glacier surface elevation gradually changed from negative to positive. The findings of this article suggest that the rate of glacier retreat on Bogda Mountain increased from 2000 to 2017.


Assuntos
Camada de Gelo , Lagos , Altitude , Mudança Climática , Abastecimento de Água
16.
World J Stem Cells ; 13(5): 342-365, 2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34136070

RESUMO

Tooth-related diseases and tooth loss are widespread and are a major public health issue. The loss of teeth can affect chewing, speech, appearance and even psychology. Therefore, the science of tooth regeneration has emerged, and attention has focused on tooth regeneration based on the principles of tooth development and stem cells combined with tissue engineering technology. As undifferentiated stem cells in normal tooth tissues, dental mesenchymal stem cells (DMSCs), which are a desirable source of autologous stem cells, play a significant role in tooth regeneration. Researchers hope to reconstruct the complete tooth tissues with normal functions and vascularization by utilizing the odontogenic differentiation potential of DMSCs. Moreover, DMSCs also have the ability to differentiate towards cells of other tissue types due to their multipotency. This review focuses on the multipotential capacity of DMSCs to differentiate into various tissues, such as bone, cartilage, tendon, vessels, neural tissues, muscle-like tissues, hepatic-like tissues, eye tissues and glands and the influence of various regulatory factors, such as non-coding RNAs, signaling pathways, inflammation, aging and exosomes, on the odontogenic/osteogenic differentiation of DMSCs in tooth regeneration. The application of DMSCs in regenerative medicine and tissue engineering will be improved if the differentiation characteristics of DMSCs can be fully utilized, and the factors that regulate their differentiation can be well controlled.

17.
J Environ Manage ; 294: 112935, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34119986

RESUMO

Anaerobic oxidation of methane (AOM) plays an important role in global carbon cycle and greenhouse gas emission reduction. In this study, an effective green technology to reduce methane emissions was proposed by introducing Mn-dependent anaerobic oxidation of methane (Mn-AOM) and microbial fuel cell (MFC) technology into constructed wetland (CW). The results indicate that the combination of biological methods and bioelectrochemical methods can more effectively control the methane emission from CW than the reported methods. The role of dissimilated metal reduction in methane control in CW and the biochemical process associated with Mn-AOM were also investigated. The results demonstrated that using Mn ore as the matrix and operating MFC effectively reduced methane emissions from CW, and higher COD removal rate was obtained in CW-MFC (Mn) during the 200 days of operation. Methane emission from CW-MFC (Mn) (53.76 mg/m2/h) was 55.61% lower than that of CW (121.12 mg/m2/h). The highest COD removal rate (99.85%) in CW-MFC (Mn) was obtained. As the dissimilative metal-reducing microorganisms, Geobacter (5.10%) was found enriched in CW-MFC (Mn). The results also showed that the presence of Mn ore was beneficial to the biodiversity of CW-MFCs and the growth of electrochemically active bacteria (EAB) including Proteobacteria (35.32%), Actinobacteria (2.38%) and Acidobacteria (2.06%), while the growth of hydrogenotrophic methanogens Methanobacterium was effectively inhibited. This study proposed an effective way to reduce methane from CW. It also provided reference for low carbon technology of wastewater treatment.


Assuntos
Fontes de Energia Bioelétrica , Anaerobiose , Metano , Águas Residuárias , Áreas Alagadas
18.
Int J Clin Exp Pathol ; 14(4): 434-443, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33936365

RESUMO

Colon cancer is a common malignancy, and its incidence and mortality have been increasing in recent years. This study aims to explore the regulation of long non-coding RNA CYTOR on proliferation and metastasis of colon cancer cells through miRNA-105/PTEN axis. Real-time quantitative PCR (qRT-PCR) disclosed that expression of CYTOR was significantly decreased in colon cancer tissues, compared with that of adjacent normal tissues, while miRNA-105 was significantly increased. Correlation study found that CYTOR was negatively correlated with miR-105. The proliferation, migration, and invasion rates of the LoVo cells with highly expressed CYTOR were significantly slower. miR-105 mimic could suppress the decrease in proliferation, migration, and invasion rates of colon cancer cells caused by overexpression of CYTOR. Additionally, the proliferation, migration, and invasion rates of the LoVo cells in miR-105 inhibition group were significantly slower. The Starbase database predicted the targeting of miR-105 by CYTOR, and qRT-PCR and dual luciferase reporter gene method were used to verify the targeting relationship of CYTOR and miRNA-105/PTEN axis. In conclusion, CYTOR can inhibit the proliferation and metastasis of colon cancer cells through targeted inhibition of the miR-105/PTEN axis.

19.
J Phys Chem A ; 125(22): 4918-4927, 2021 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-34038116

RESUMO

The transport properties of chemical species such as coefficients of diffusion, thermal conductivity, and viscosity have been widely used in combustion modeling. Lennard-Jones parameters fitted from the accurate intermolecular potential energy surfaces are crucial to obtain such information. Hence, a fast and accurate energy function is always desired for this purpose. In this study, the quality of a widely used polarizable force field AMOEBA was examined for the interaction between noble gases and n-alkanes. First, the intermolecular energy was compared between AMOEBA, MP2/CBS, MP2/aug'-cc-pVDZ, and QCISD(T)/CBS. The root mean squared error of the original AMOEBA was 10.31 cm-1 against QCISD(T)/CBS for all conformations. This was comparable with the errors of 10.84 and 7.75 cm-1 for MP2/aug'-cc-pVDZ and MP2/CBS, respectively. Further optimizing the van der Waals parameters of noble gases, the error of the force field against QCISD(T)/CBS was reduced to 6.24 cm-1, even better than the MP2/CBS results. Based on the optimized force field parameters, the intermolecular Lennard-Jones parameters were derived using the spherically averaged method and one-dimensional minimization method for a set of (n-alkanes, noble gases) pairs. The discrepancy of the one-dimensional minimization predicted Lennard-Jones collision rates from the tabulated values was typically within 10%, while it could be as large as 20-30% for the spherically averaged method. Additionally, the binary diffusion coefficients were calculated using the present Lennard-Jones parameters. In this case, the parameters derived from the spherically averaged method perform better. The mean unsigned error of the diffusion coefficients is usually within 5%, which is in good agreement with the experimental results. The results demonstrate that the AMOEBA force field can be used to generate the transport parameters systematically.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...