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1.
Ecotoxicol Environ Saf ; 267: 115667, 2023 Nov 15.
Article in English | MEDLINE | ID: mdl-37944466

ABSTRACT

The dinoflagellate Karenia mikimotoi is a toxic bloom-forming species that threatens aquaculture and public health worldwide. Previous studies showed that K. mikimotoi induces neurotoxicity; however, the underlying mechanism is poorly understood. In this study, three neural cell lines were used to investigate the potential neurotoxicity of K. mikimotoi. The tested cells were exposed to a ruptured cell solution (RCS) of K. mikimotoi at different concentrations (0.5 × 105, 1.0 × 105, 2.0 × 105, 4.0 × 105, and 6 × 105 cells mL-1) for 24 h, and the RCS decreased cell viabilities and promoted Neuro-2a (N2A) cell apoptosis in a dose-dependent manner. The underlying mechanism was further investigated in N2A cells. At the biochemical level, the RCS stimulated reactive oxygen species (ROS) and malondialdehyde (MDA) formation, decreased SOD activity, and reduced mitochondrial membrane potential (MMP). At the gene level, the moderate RCS treatment (2.0 × 105 cells mL-1) upregulated antioxidant response genes (e.g., nrf-2, HO-1, NQO-1, and cat) to alleviate RCS-induced oxidative stress, while the high RCS treatment (4.0 × 105 cells mL-1) downregulated these genes, thereby aggravating oxidative stress. Meanwhile, apoptosis-related genes (e.g., p53, caspase 3, and bax2) were significantly upregulated and the anti-apoptotic gene bcl2 was suppressed after RCS treatment. Western blotting results for Caspase 3, Bax2 and Bcl2 were consistent with the mRNA trends. These results revealed that K. mikimotoi RCS can induce neural cell apoptosis via the oxidative stress-mediated mitochondrial pathway, providing novel insights into the neurotoxicity of K. mikimotoi.


Subject(s)
Dinoflagellida , Dinoflagellida/genetics , Caspase 3 , Oxidative Stress , Apoptosis , Proto-Oncogene Proteins c-bcl-2
2.
Neurol Sci ; 41(5): 1193-1199, 2020 May.
Article in English | MEDLINE | ID: mdl-31901124

ABSTRACT

INTRODUCTION: To improve the accuracy of ultrasound techniques for the assessment of carotid stenosis, we designed a novel carotid artery stenosis ultrasound scale (CASUS), and evaluated its accuracy, reliability, and its value in predicting the occurrence of cardiovascular and cerebrovascular diseases in a prospective study. METHODS: A total of 750 patients with first-time ischemic stroke and hospitalized within 24 h were enrolled in the study. Using color Doppler ultrasound (CDUS), the degree of stenosis and blood flow (BF) in bilateral internal carotid arteries (ICA) and the V1-V3 segment of vertebral arteries (VA) was assessed. Cubic simulation curves for BF and global blood flow (GBF) over the stenosis score (SS), total stenosis score (TSS), and radiological imaging- total stenosis score (RI-TSS) were fitted and compared. The receiver operating characteristic (ROC) curves using TSS, RI-TSS, or GBF to predict various ischemic stroke endpoints were also analyzed and compared. RESULTS: There was a linear relationship between SS and BF both ICA and VA (R2 were 0.734 and 0.783, respectively, both P < 0.05). Both TSS and RI-TSS with GBF showed an inverse "S" curve relationship (R2 was 0.839 and 0.843, all P < 0.05). The AUC values of TSS-based and RI-TSS-based predictions of each endpoint were all greater than 0.7 (all P < 0.05), but the differences of the AUC values between TSS, RI-TSS, and GBF were not statistically significant (all P > 0.05). CONCLUSIONS: The novel CASUS can better reflect the level of cerebral reperfusion in patients with ischemic stroke and can better predict the occurrence of cardiovascular and cerebrovascular diseases.


Subject(s)
Carotid Artery, Internal/diagnostic imaging , Carotid Stenosis/diagnostic imaging , Ischemic Stroke/diagnostic imaging , Ultrasonography, Doppler , Vertebral Artery/diagnostic imaging , Aged , Carotid Artery, Internal/pathology , Female , Humans , Ischemic Stroke/pathology , Male , Middle Aged , Prospective Studies , Sensitivity and Specificity , Vertebral Artery/pathology
3.
Langmuir ; 32(17): 4297-304, 2016 05 03.
Article in English | MEDLINE | ID: mdl-27064754

ABSTRACT

Well-defined thermoswitchable Janus gold nanoparticles with stimuli-responsive hydrophilic polymer brushes were fabricated by combining ligand exchange reactions and the Langmuir technique. Stimuli-responsive polydi(ethylene glycol) methyl ether methacrylate was prepared by addition-fragmentation chain-transfer polymerization. The polymer brushes were then anchored onto the nanoparticle surface by interfacial ligand exchange reactions with hexanethiolate-protected gold nanoparticles, leading to the formation of a hydrophilic (polymer) hemisphere and a hydrophobic (hexanethiolate) one. The resulting Janus nanoparticles showed temperature-switchable wettability, hydrophobicity at high temperatures, and hydrophilicity at low temperatures, due to thermally induced conformational transition of the polymer ligands. The results further highlight the importance of interfacial engineering in the deliberate functionalization of nanoparticle materials.

4.
Int J Gen Med ; 16: 2047-2053, 2023.
Article in English | MEDLINE | ID: mdl-37275333

ABSTRACT

Background: To investigate the existence and degree of correlation between benign ovarian tumors and physiological indicators such as reproductive hormones and tumor markers. Methods: A total of 150 patients with benign ovarian tumors admitted to Jiaxing First Hospital between January 1, 2019, and May 30, 2021, were enrolled as research subjects, while 104 healthy women were enrolled in the control group. Comparative analysis of the correlation between the reproductive hormones LH, FSH, T, E2, and the tumor indicators AMH, AFP, CEA, CA125, and CA199 between the groups was performed. Results: There was no statistical difference in LH, FSH, T, AMH, and CEA expression levels between the experimental and control groups (p≥0.05); E2, CA125, and CA199 levels were higher significantly in the experimental group than in the control group (P<0.001); AFP levels were significantly lower in the experimental group than in the control group (P<0.05). CA125 (0.762) had the highest AUC when diagnosing the value of each index of E2, CA125, and CA199 for benign ovarian tumors. CA125 had the highest sensitivity (56.7%), followed by E2 (50.0%); CA199 had the highest specificity (84.5%), followed by CA125 (83.7%). The combined diagnosis of benign ovarian tumors was performed using different combinations of the indicators. When the two indicators were combined for diagnosis, the combination of E2 + CA199 had the highest sensitivity (82.6%), whereas the combination of CA125 + CA199 had the largest AUC (0.783) and the highest specificity (86.4%). The combined diagnosis of E2+CA125+CA199 had a higher AUC than the combined diagnosis of the two indicators (0.805), with a sensitivity of 77.2%, and a specificity of 70.9%. Conclusion: The most relevant factors for benign ovarian tumors are E2, CA125, and CA199 and the combination of these three indicators has the highest AUC for disease prediction while increasing the detection rate of benign ovarian tumors.

5.
Infect Drug Resist ; 16: 5911-5921, 2023.
Article in English | MEDLINE | ID: mdl-37700799

ABSTRACT

Background: Urinary tract infections (UTIs) and the antibiotic resistance of pathogenic bacteria pose severe threats to public health in the current healthcare environment. Objective: The purpose of this study was to assess the frequency distribution of bacterial pathogens causing UTIs as well as the characteristics of antibiotic susceptibility and resistance. Methods: The retrospective study was conducted on 32,391 samples of midstream urine culture from January 1, 2020, to December 31, 2022, in Jiaxing. Bacteria were cultivated on blood agar and identified using MALDI-TOF, and their susceptibility to different antibiotics was assessed using the Kirby-Bauer disk diffusion method and drug sensitivity reaction cards. The SPSS 22 software was used for data analysis. Bivariate logistic regression was used to analyze the risk factors for multidrug resistance. Results: The total number of positive growth samples was 5378 (16.6%), including 3206 females (59.6%) and 2172 males (40.4%). The four most common urinary pathogens were Escherichia coli (39.2%), Enterococcus faecalis (12.4%), Klebsiella pneumoniae (7.6%), and Enterococcus faecium (7.6%). As far as antibiotic resistance was concerned, Escherichia coli had a greater than 50% resistance rate to ampicillin (76.1%), ciprofloxacin (58.6%), and levofloxacin (51.2%). The multidrug resistance rate was high (41.8%). Low levels of resistance were seen to ertapenem (0.1%), imipenem (0.7%), meropenem (0.7%), piperacillin/tazobactam (0.7%), and nitrofurantoin (1.8%). Klebsiella pneumoniae was highly sensitive to ertapenem (100%). The resistance rates to nitrofurantoin, ceftriaxone, and ciprofloxacin were 37.4%, 37.1%, and 35.1%, respectively. Up to 41% of Escherichia coli strains and 26% of Klebsiella pneumoniae strains produced extended-spectrum lactamases (ESBL). Two species of enterococci were highly sensitive to tigecycline and linezolid (100%), and a small number of norvancomycin-resistant strains (0.2%/two strains) were found. Conclusion: Escherichia coli and Enterococcus faecium were the most common urinary pathogens in this study. The isolated pathogens showed different sensitivity patterns. Antibiotics should be selected reasonably according to the sensitivity mode of pathogenic bacteria to effectively treat and prevent urinary tract infections.

6.
RSC Adv ; 13(34): 23682-23689, 2023 Aug 04.
Article in English | MEDLINE | ID: mdl-37555096

ABSTRACT

Covalent organic frameworks (COFs), featured with crystalline structures, permanent porosity, and designable organic skeletons, are good candidates for serving as adsorbents. Herein, a new pyridine-based two-dimensional COF (TAPP-DBTA-COF) was constructed via the condensation of 2,4,6-tris(4-aminophenyl)pyridine and 2,5-dibromobenzene-1,4-dicarbaldehyde. TAPP-DBTA-COF displayed high-performance for the removal of rhodamine B (Rh B) from water with high capacity, good adaptability and reusability. The maximum adsorption capacity for Rh B can reach up to 1254 mg g-1, and the kinetic constant was determined as k2 = 0.00244 g mg-1 min-1. Moreover, the corresponding amorphous polymer of TAPP-DBTA-COF, termed as TAPP-DBTA-COP, was synthesized from the same starting materials. The lower efficiency of TAPP-DBTA-COP in capture of Rh B revealed that the ordered pore structure, large specific surface area and rich adsorption sites play an important role in adsorption.

7.
Membranes (Basel) ; 12(12)2022 Nov 29.
Article in English | MEDLINE | ID: mdl-36557114

ABSTRACT

It is a great challenge to design and prepare polymeric membranes with excellent permeability and good rejection. In this study, a modifier of gold nanoparticles for crosslinking and self-assembly by 1,6-hexanedithiol is fabricated and used to modify the polyethersulfone membrane as an additive, which forms a uniform porous membrane by liquid-liquid phase conversion technology. The morphology of the membrane is investigated by scanning electron microscopy (SEM), the change of the hydrophilicity of the membrane surface after modification is measured by the contact angle goniometer, and the performance of the fabricated membrane is measured by evaluating the pure water flux and the rejection ratio of bovine serum albumin. The results indicate that the permeability of the modified membrane has a significant improvement. When the mass fraction of the modifying agent is 5 wt%, the water flux of the modified membrane reaches up to 131.6 L m-2 h-1, and has a good rejection ratio to bovine serum albumin. In short, this work plays an important role in improving the flux of the membrane and maintaining good separation performance.

8.
Food Res Int ; 159: 111608, 2022 09.
Article in English | MEDLINE | ID: mdl-35940802

ABSTRACT

Whole tomato juice (WTJ) was prepared using a novel "industrial-scale microfluidizer system" (ISMS). The impacts of ISMS processing pressure (0-120 MPa) on the physicochemical properties and bioaccessibility of tomato juice were investigated. Increasing the processing pressure reduced the mean particle diameter (D[4,3]) of the tomato juice from 151 to 30 µm, which was mainly attributed to degradation of the tomato plant cell structures by the strong disruptive forces generated by microfluidizer. Pulp sedimentation rate, precipitation weight ratio, and turbidity measurements showed that the physical stability of the tomato juice increased with increasing pressure. Indeed, ISMS-treated tomato juice remained stable for 28 days without evidence of visible layering. The lycopene concentration in the tomato juice increased from 25.0 to 28.2 µg/mL and the lycopene bioaccessibility increased from 9.0% to 14.1% after ISMS treatment. These results suggest that ISMS can improve the physical stability and nutritive value of commercial tomato juice products.


Subject(s)
Solanum lycopersicum , Carotenoids/analysis , Food Handling/methods , Fruit and Vegetable Juices , Lycopene/metabolism , Solanum lycopersicum/chemistry
9.
J Hypertens ; 40(4): 749-757, 2022 04 01.
Article in English | MEDLINE | ID: mdl-34980864

ABSTRACT

BACKGROUND: Evidence suggests that patients with higher blood pressure variability (BPV) have a higher risk for stroke but the relationship between BPV and stroke outcomes is unknown in those who underwent intravenous thrombolysis (IVT) for acute ischemic stroke (AIS). The objective of this study is to investigate the association among BPV, BP values and stroke outcomes. METHODS: A retrospective analysis of about 510 consecutive thrombolysis cases for AIS from January 2015 to March 2019 in a single-center database were done. Then, these patients were followed-up for 3 months. We used univariate and multivariable models to evaluate the relationship between mean BP values, BPV and the risk of stroke outcomes from prior IVT to 72 h after IVT. Meanwhile, we also used COX regression to assess the hazard ratios of stroke outcomes with BPV within 3 months. Furthermore, we tested the effect of BP level at various time-points (prior to IVT and at 0, 2, 4, 8, 12, 24, 48 and 72 h after IVT) on development of postthrombolytic stroke outcomes. RESULTS: Higher BPV from prior IVT to 72 h after IVT was associated with higher risk of stroke outcomes within 3 months [SBPV of recurrent stroke: odds ratios (OR) = 5.298, 95% confidence interval (CI) 1.339-10.968, P = 0.018; DBPV of recurrent stroke: OR = 6.397, 95% CI 1.576-25.958, P = 0.009, respectively]. In addition, patients with recurrent stroke had significantly higher mean SBP (OR=1.037, 95% CI 1.006-1.069, P = 0.019). Furthermore, higher BP at different time points were associated with greater risk of recurrent stroke from prior IVT to 72 h after IVT. CONCLUSION: Higher BPV and SBP from prior IVT to 72 h after IVT was associated with higher risk of stroke outcomes within 3 months.


Subject(s)
Brain Ischemia , Ischemic Stroke , Stroke , Blood Pressure/physiology , Brain Ischemia/complications , Brain Ischemia/drug therapy , Fibrinolytic Agents/adverse effects , Humans , Prognosis , Retrospective Studies , Thrombolytic Therapy , Treatment Outcome
10.
Aging (Albany NY) ; 14(14): 5749-5767, 2022 Jul 13.
Article in English | MEDLINE | ID: mdl-35832033

ABSTRACT

The relationship between red blood cell distribution width (RDW) in peripheral thrombolysis period and prognosis is not fully clarified in those who underwent intravenous thrombolysis (IVT) for acute ischemic stroke (AIS). Our study aimed to clarify this issue. A retrospective analysis of about 510 consecutive thrombolysis cases for AIS from January 2015 to March 2019 in a single-center database was done and followed-up for 3 months. We used univariate and multivariable models to evaluate the relationship between RDW levels at various time-points after IVT and the occurrence risk of hemorrhagic transformation (HT) and recurrent stroke, and used COX regression to assess the hazard ratios of outcomes with RDW levels. Elevated risk of HT was found in higher tertiles of RDW (OR = 10.282, 95% confidence interval (CI) 2.841-39.209, P < 0.001 in Tp tertile G3; OR = 5.650, 95% CI 1.992-16.025, P = 0.001 in T24 tertile G3; OR = 4.308, 95% CI 1.480-12.542, P = 0.007 in T48 tertile G3 and OR = 6.384, 95% CI 2.201-18.515, P = 0.001 in T72 tertile G3, respectively). Occurrence of recurrent stroke was highest in the RDW tertile G3 (HR = 4.580, 95% CI 2.123-9.883, P < 0.001 in Tp tertile G3; HR = 5.731, 95% CI 2.498-13.151, P = 0.001 in T24 tertile G3; HR = 3.019, 95% CI 1.969-4.059, P = 0.031 in T48 tertile G3; HR = 3.318, 95% CI 1.598-6.890, P = 0.001 in T72 tertile G3, respectively). Mean RDW levels ≥13.60 among AIS patients undergoing thrombolysis was associated with higher risk of HT and recurrent stroke.


Subject(s)
Ischemic Stroke , Stroke , Erythrocytes , Humans , Ischemic Stroke/drug therapy , Prognosis , Retrospective Studies , Thrombolytic Therapy
11.
Harmful Algae ; 103: 101996, 2021 03.
Article in English | MEDLINE | ID: mdl-33980436

ABSTRACT

Karenia mikimotoi is a toxic dinoflagellate that forms harmful blooms in coastal waters, threatening aquaculture worldwide. However, we do not know whether K. mikimotoi has a neurotoxic effect on aquatic animal behavior. Thus, this study investigated potential K. mikimotoi neurotoxicity in zebrafish larvae. Cells of K. mikimotoi were collected at the mid-exponential phase from a batch culture to prepare ruptured cell solutions (RCS). At 6 h post-fertilization (hpf), zebrafish embryos were exposed to different RCS concentrations (0, 102, 103, 104, and 2.5 × 104 cells mL-1). After 120 hpf, treated larvae were collected to analyze locomotor behavior; activities of acetylcholinesterase (AChE), superoxide dismutase (SOD), catalase (CAT); and expression of genes related to neurodevelopment. We found that RCS did not affect survival rate, but significantly decreased larval locomotion, as well as their AChE, SOD, and CAT activity. Additionally, the examination of the day-night behavioral experiment revealed RCS decreased locomotion only at night. Zebrafish larvae were also significantly hypoactive in response to light and sound stimulations. Of the neurodevelopment genes, three (th, neurog1, and neurod1) were downregulated, while two (bdnf and manf) were upregulated. Our study suggests that K. mikimotoi neurotoxicity occurs through causing oxidative damage, as well as disorders in the cholinergic system and nervous system development. The results provide new insight that K. mikimotoi in low abundance did not cause significant lethal effect but still exhibited significant neurotoxicity on aquatic animals.


Subject(s)
Dinoflagellida , Animals , Aquaculture , Larva , Oxidative Stress , Zebrafish
12.
J Hypertens ; 39(7): 1453-1461, 2021 07 01.
Article in English | MEDLINE | ID: mdl-33560058

ABSTRACT

BACKGROUND: Dramatic changes of blood pressure (BP) were observed in the peripheral thrombolysis period, however, there is no consensus about BP control targets in the different phases. METHODS: We retrospectively studied a consecutive sample of 510 patients treated with intravenous thrombolysis and followed-up for 3 months. The peripheral thrombolysis period was divided into these phases: Phase 1 (from onset to thrombolysis), Phase 2 (thrombolysis), Phase 3 (from thrombolysis to 24 h after thrombolysis), and Phase 4 (from 24 h to 7 days after thrombolysis). Patients were divided into quintiles according to mean blood pressure in these phases, respectively. Neurological improvement was evaluated using the modified Rankin Scale score at 3-month after thrombolysis. RESULTS: Lower risk of intracerebral hemorrhage within 7 days was found in lower quintiles of SBP (OR = 0.100, 95% CI 0.011-0.887, P = 0.039 in Phase 1 quintile Q1, OR = 0.110, 95% CI 0.012-0.974, P = 0.047 in Phase 2-3 quintile Q1, and OR, 0.175, 95% CI, 0.035-0.872; P = 0.033 in Phase 4 quintile Q2, respectively). Better neurological improvement was found in SBP quintiles: Q2-Q4 (127.3-155.7 mmHg) in Phase 4 (OR = 3.095, 95% CI 1.524-6.286, P = 0.002 for Q2; OR = 2.697, 95% CI 1.354-5.370, P = 0.005 for Q3; and OR = 2.491, 95% CI 1.263-4.913, P = 0.008 for Q4, respectively). Our results also showed higher average real variability of SBP was negatively associated with better neurological outcome in Phase 1 and Phase 2-3. CONCLUSIONS: Maintaining SBP levels (≤148 mmHg) from admission to the first 24 h after thrombolysis, then keeping SBP levels (127-138 mmHg) would be beneficial.


Subject(s)
Brain Ischemia , Ischemic Stroke , Stroke , Blood Pressure , Brain Ischemia/drug therapy , Humans , Retrospective Studies , Stroke/drug therapy , Thrombolytic Therapy , Treatment Outcome
13.
J Clin Hypertens (Greenwich) ; 23(12): 2089-2099, 2021 12.
Article in English | MEDLINE | ID: mdl-34783432

ABSTRACT

To investigate the optimal blood pressure (BP) levels and relative importance of BP and BP variability in the early phase of acute ischemic stroke (AIS) for hypertensive patients with carotid artery stenosis (CAS). A single-center cohort study included 750 AIS patients with hypertension and tests were performed for CAS. Participants were categorized to Group 1 (SBP < 140 mm Hg and DBP < 90 mm Hg), Group 2: (SBP: 140-159 mm Hg and or DBP: 90-99 mm Hg), and Group 3: (SBP ≥160 mm Hg and/or DBP ≥100 mm Hg) according to the guidelines. The associations of mean BP levels and variability with outcomes (recurrent stroke, all-cause death and the composite cardiovascular events) at 6 months were analyzed by Cox proportional hazard models. The associations of BP variability with BP levels and cerebral blood flow (CBF) were analyzed by linear regression and generalized additive models. Both for primary and secondary outcome, more events occurred in Group 1 compared with Group 2, while no significant difference was found in Group 3 with higher BP levels. Lower systolic BP variability showed better prognosis and higher CBF. The associations were more significant in patients with CAS ≥50%. BP variability exhibited a linear negative relationship with BP levels. In the early phase of AIS with hypertension and CAS, maintaining low blood pressure variability may be important to improve outcomes while low BP levels (SBP/DBP < 140/90 mm Hg) were harmful, especially in those patients with CAS ≥ 50%.


Subject(s)
Brain Ischemia , Carotid Stenosis , Hypertension , Ischemic Stroke , Stroke , Blood Pressure , Brain Ischemia/diagnosis , Brain Ischemia/epidemiology , Carotid Stenosis/complications , Carotid Stenosis/diagnosis , Carotid Stenosis/epidemiology , Cohort Studies , Humans , Hypertension/complications , Hypertension/diagnosis , Hypertension/epidemiology , Risk Factors , Stroke/epidemiology , Stroke/etiology
14.
Food Res Int ; 129: 108802, 2020 03.
Article in English | MEDLINE | ID: mdl-32036926

ABSTRACT

Phenolic acids are added to some dairy products as functional ingredients. The molecular interactions between the phenolic acids and milk proteins impacts their functional performance and product quality. In this study, the interactions between a milk protein (ß-casein) and a number of phenolic acids was investigated: 3,4-dihydroxybenzoic acid (DA); gallic acid (GA); syringic acid (SA); caffeic acid (CaA); ferulic acid (FA); and, chlorogenic acid (ChA). The structural characteristics of the phenolic acids, such as type, hydroxylation, methylation, and steric hindrance, affected their binding affinity to ß-casein. The strength of the binding constant decreased in the following order: CaA > ChA > FA > SA > GA > DA. Cinnamic acid derivatives (CaA, FA, and ChA) exhibited a stronger binding affinity with ß-casein than benzoic acid derivatives (DA, GA, and SA). Hydrophobic forces and electrostatic interactions dominated the interactions of ß-casein with benzoic acid and cinnamic acid derivatives, respectively. The number of hydroxyl groups on the phenolic acids enhanced their binding ability, while steric hindrance effects reduced their binding ability. The influence of methylation depended on phenolic acid type. After binding with phenolic acids, the conformation of the ß-casein changed, with a loss of random coil structure, an increase in α-helix structure, and a decrease in surface hydrophobicity. Furthermore, the presence of ß-casein decreased the in vitro antioxidant capacities of the phenolic acids, especially for gallic acid. These findings provide some useful insights into the structure-activity relationships of the interaction between ß-casein and phenolic acids.


Subject(s)
Antioxidants/chemistry , Caseins/chemistry , Hydroxybenzoates/chemistry , Caffeic Acids/chemistry , Chlorogenic Acid/chemistry , Circular Dichroism , Coumaric Acids/chemistry , Gallic Acid/analogs & derivatives , Gallic Acid/chemistry , Hydrophobic and Hydrophilic Interactions
15.
Food Chem ; 309: 125768, 2020 Mar 30.
Article in English | MEDLINE | ID: mdl-31727512

ABSTRACT

There is interest in extending the functionality of natural polymers using simple chemical derivatization methods. In this study, the ability of pectin to react with various amino acids (40 °C) in aqueous solution without a catalyst was investigated, including glutamic acid, glycine, cysteine, lysine, and arginine. Only glycine, lysine, and arginine could form conjugates with pectin under these conditions. Amino acid-amidated pectin (AAAP) conjugates with a degree of amidation of 6.50% were prepared and characterized using elemental analysis, FT-IR, and 1H NMR. Size exclusion chromatography combined with multiangle light scattering and refractive index detection indicated pectin degradation occurred during the reaction. These results were supported by measurements of apparent viscosities. Scanning electron microscopy showed appreciable differences among the surface topographies of samples. Cell culture experiments showed the AAAP conjugates exhibited no cytotoxic effects. Our results suggested the AAAP conjugates may be suitable for use as new functional ingredients in food industry.


Subject(s)
Amines/chemistry , Amino Acids/chemistry , Pectins/chemistry , Cell Survival/drug effects , Human Umbilical Vein Endothelial Cells , Humans , Magnetic Resonance Spectroscopy , Microscopy, Electron, Scanning , Molecular Weight , Pectins/pharmacology , Rheology , Spectroscopy, Fourier Transform Infrared
16.
RSC Adv ; 9(44): 25274-25284, 2019 Aug 13.
Article in English | MEDLINE | ID: mdl-35530106

ABSTRACT

Polyethersulfone (PES) has good thermal stability, superior pH, chlorine tolerance, and excellent chemical resistance; however, the hydrophilicity and biocompatibility of PES need to be improved for its real applications. In this study, we report a surface modification method for the preparation of a functional PES membrane with hydrophilic polymer chains (MPC and GMA) via surface-initiated electrochemically-mediated atom-transfer radical polymerization (SI-eATRP) technology, and the Arg-Glu-Asp-Val polypeptide groups (REDV) were immobilized onto the modified membrane by a ring-opening reaction. XPS and SEM were used to analyze the chemical composition and morphology of the modified membrane surfaces, confirming that the hydrophilic polymer chains MPC and GMA and the polypeptide group REDV were successfully grafted onto the PES membrane surface. The static water contact angle decreased from 89° to 50-65°, and the hydrophilic property of the modified membrane was enhanced. The water flux increased from 4.29 L m-2 h-1 for the pristine PES membrane to 25 L m-2 h-1 for the modified membrane with PGMA chains grafted on it and REDV functional groups immobilized on it; note that the antifouling tests showed that all the modified membranes had the higher flux recovery ratio values (FRR) of above 80% than the pristine PES membrane (about 60%), and the APTT for the modified membrane increased from 46 s to 93 s, indicating that these modified membranes could be applied in the separation and blood purification fields.

17.
Harmful Algae ; 87: 101621, 2019 07.
Article in English | MEDLINE | ID: mdl-31349890

ABSTRACT

This work demonstrated a 10-day batch culture experiment to test the physiology and toxicity of harmful dinoflagellate Karenia mikimotoi in response to ocean acidification (OA) under two different phosphate concentrations. Cells were previously acclimated in OA (pH = 7.8 and CO2 = 1100 µatm) condition for about three months before testing the responses of K. mikimotoi cells to a two-factorial combinations experimentation. This work measured the variation in physiological parameters (growth, rETR) and toxicity (hemolytic activity and its toxicity to zebrafish embryos) in four treatments, representing two factorial combinations of CO2 (450 and 1100 µatm) and phosphate concentration (37.75 and 4.67 umol l-1). Results: OA stimulated the faster growth, and the highest rETRmax in high phosphate (HP) treatment, low phosphate (LP) and a combination of high CO2 and low phosphate (HC*LP) inhibited the growth and Ek in comparison to low CO2*high phosphate (LCHP) treatment. The embryotoxicity of K. mikimotoi cells enhanced in all high CO2 (HC) conditions irrespective of phosphate concentration, but the EC50 of hemolytic activity increased in all high CO2 (HC) and low phosphate (LP) treatments in comparison of LCHP. Ocean acidification (high CO2 and lower pH) was probably the main factor that affected the rETRmax, hemolytic activity and embryotoxicity, but low phosphate was the main factor that affected the growth, α, and Ek. There were significant interactive effects of OA and low phosphate (LP) on growth, rETRmax, and hemolytic activity, but there were no significant effects on α, Ek, and embryotoxicity. If these results are extrapolated to the aquatic environment, it can be hypothesized that the K. mikimotoi cells were impacted significantly by future changing ocean (e.g., ocean acidification and nutrient stoichiometry).


Subject(s)
Dinoflagellida , Batch Cell Culture Techniques , Hydrogen-Ion Concentration , Phosphates , Seawater
18.
Mater Sci Eng C Mater Biol Appl ; 95: 122-133, 2019 Feb 01.
Article in English | MEDLINE | ID: mdl-30573233

ABSTRACT

We report a convenient, highly efficient, and universal approach for blood-compatible modification of polymer membrane based on the SI-eATRP, RAFT, and self-assembly of N-tert-butyl amide and ß-cyclodextrin existed in macromolecules chains. The functional membrane surfaces with any polymer chains of hydrophilic, ionic polymer, and polysaccharide segments, for example, the copolymers of N-vinyl pyrrolidone, sodium p-styrenesulfonate hydrate, and glucose allyl amide, are easily designed and fabricated; and the thickness of polymer brushes are efficiently controlled by polymerization conditions like monomer concentration and initiator amount. As a key bio-plastic, the modified polyethersulfone membrane shows suppressed platelet adhesion, significant decreases in thrombin-antithrombin generation, and the complement activations on C3a and C5a levels compared with pristine polyethersulfone membrane; while the platelet activation (PF4) decreased. Due to the similar groups as heparin-like structure, the modified membrane effectively prolonged the activated partial thromboplastin time, thrombin time, and prothrombin time. The water contact angle of the modified membrane decreases from 89.2 to 22.3°, and the cytocompatibility of the modified membranes largely enhanced. It could be concluded that the new approach could be widely used for polymer membrane modification, and the mimic heparin-like surface seems to be a promising structure to improve the biocompatibility for blood purification application.


Subject(s)
Biocompatible Materials/chemistry , Polymers/chemistry , beta-Cyclodextrins/chemistry , Electrochemistry , Enzyme-Linked Immunosorbent Assay , Spectroscopy, Fourier Transform Infrared , Surface Properties
19.
Harmful Algae ; 88: 101640, 2019 09.
Article in English | MEDLINE | ID: mdl-31582153

ABSTRACT

Solar ultraviolet radiation (UVR) is a stress factor in aquatic environments and may act directly or indirectly on orgnisms in the upper layers of the water column. However, UVR effects are usually species-specific and difficult to extrapolate. Here we use the HAB-forming, toxic dinoflagellate Karenia mikimotoi (which was found to be relatively resistant in previous studies) to investigate its transcriptional responses to a one-week UVR exposure. For this, batch cultures of K. mikimotoi were grown with and without UVR, and their transcriptomes (generated via RNAseq technology) were compared. RNA-seq generated 45.31 million reads, which were further assembled to 202600 unigenes (>300bp). Among these, ca. 61% were annotated with NCBI, NR, GO, KOG, PFAM, Swiss-Prot, and KEGG database. Transcriptomic analysis revealed 722 differentially expressed unigenes (DEGs, defined as being within a |log2 fold change| ≥ 2 and padj < 0.05) responding to solar UVR, which were only 0.36% of all unigenes. 716 unigenes were down-regulated, and only 6 unigenes were up-regulated in the UVR compared to non-UVR treatment. KEGG pathway further analysis revealed DEGs were involved in the different pathway; genes involved in the ribosome, endocytosis and steroid biosynthesis pathways were highly down-regulated, but this was not the case for those involved in the energy metabolisms (including photosynthesis, oxidative phosphorylation) which may contribute to the sustainable growth observed in UVR treatment. The up-regulated expression of both zinc-finger proteins (ZFPs) and ribosomal protein L11 (RPL11) may be one of the acclimated mechanisms against UVR. In addition, this work identified down-regulated genes involved in fatty acid degradation and the hydrophobic branched chain amino acids (e.g., Valine, leucine, and isoleucine), which act as structural components of cell membranes modulating lipid homeostasis or turnover. In conclusion, the present study suggests that the toxic dinoflagellate K. mikimotoi has limited transcriptomic regulation but confirms that it appears as a tolerant species in response to solar UVR. These findings expand current knowledge of gene expression in HAB-forming species in response to natural environment factors such as solar radiation.


Subject(s)
Dinoflagellida , Gene Expression Profiling , Photosynthesis , Transcriptome , Ultraviolet Rays
20.
Nanomicro Lett ; 9(1): 6, 2017.
Article in English | MEDLINE | ID: mdl-30460303

ABSTRACT

ABSTRACT: Hybrid materials of vanadium nitride and porous carbon nanoparticles (VN/PCNPs) were fabricated by a facile pyrolysis process of vanadium pentoxide (V2O5) xerogel and melamine at relatively low temperature of 800 °C for supercapacitor application. The effects of the feed ratio of V2O5 to melamine (r), and nitrogen flow rate on the microstructure and electrochemical performance were also investigated. It was found that the size of the as-synthesized nanoparticles is about 20 nm. Both r value and N2 flow rate have enormous impacts on morphology and microstructure of the nanoparticle, which correspondingly determined the electrochemical performance of the material. The VN/C hybrid nanoparticles exhibited high capacitive properties, and a maximum specific capacitance of 255.0 F g-1 was achieved at a current density of 1.0 A g-1 in 2 M KOH aqueous electrolyte and the potential range from 0 to -1.15 V. In addition, symmetrical supercapacitor fabricated with the as-synthesized VN/PCNPs presents a high specific capacitance of 43.5 F g-1 at 0.5 A g-1 based on the entire cell, and an energy density of 8.0 Wh kg-1 when the power density was 575 W kg-1. Even when the power density increased to 2831.5 W kg-1, the energy density still remained 6.1 Wh kg-1.

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