Impact of hypoxia on glucose metabolism and hypoxia signaling pathways in juvenile horseshoe crabs Tachypleus tridentatus.

Marine hypoxia poses a significant challenge in the contemporary marine environment. The horseshoe crab, an ancient benthic marine organism, is confronted with the potential threat of species extinction due to hypoxia, making it an ideal candidate for studying hypoxia tolerance mechanisms. In this experiment, juvenile Tachypleus tridentatus were subjected to a 21-day trial at DO:2 mg/L (hypoxia) and DO:6 mg/L conditions. The experimental timeline included a 14-day exposure phase followed by a 7-day recovery period. Sampling occurred on days 0, 7, 14, and 21, where the period from day 14 to day 21 corresponds to seven days of recuperation. Several enzymatic activities of important proteins throughout this investigation were evaluated, such as succinate dehydrogenase (SDH), phosphofructokinase (PFK), hexokinase (HK), lactate dehydrogenase (LDH), and pyruvate kinase (PK). Concurrently, the relative expression of hexokinase-1 (HK), hypoxia-inducible factor 1-alpha inhibitor (FIH), and hypoxia-inducible factor 1-alpha (HIF-1α), pyruvate dehydrogenase phosphatase (PDH), succinate dehydrogenase assembly factor 4 (SDH), and Glucose-6-phosphatase (G6Pase) were also investigated. These analyses aimed to elucidate alterations in the hypoxia signaling pathway and respiratory energy metabolism. It is revealed that juvenile T. tridentatus initiated the HIF pathway under hypoxic conditions, resulting in an upregulation of HIF-1α and FIH-1 gene expression, which in turn, influenced a shift in metabolic patterns. Particularly, the activity of glycolysis-related enzymes was promoted significantly, including PK, HK, PKF, LDH, and the related HK gene. In contrast, enzymes linked to aerobic respiration, PDH, and SDH, as well as the related PDH and SDH genes, displayed down-regulation, signifying a transition from aerobic to anaerobic metabolism. Additionally, the activity of gluconeogenesis-related enzymes such as PK and G6Pase gene expression were significantly elevated, indicating the activation of gluconeogenesis and glycogenolysis pathways. Consequently, juvenile T. tridentatus demonstrated an adaptive response to hypoxic conditions, marked by changes in respiratory energy metabolism modes and the activation of hypoxia signaling pathways.

Saving the overlooked mangrove horseshoe crabs-A perspective from enhancing mangrove ecosystem conservation.

Despite being widely distributed in Asia, Carcinoscorpius rotundicauda is often overlooked and, its population status remains unclear. Moreover, it is threatened by illegal harvesting and degradation of mangrove ecosystems. Protecting its habitat is essential for population and biodiversity conservation, as mangroves provide nursery grounds and food supply for C. rotundicauda. This review discusses the biological characteristics of C. rotundicauda, including ecology, nutrition, life history, toxicology, and immunology. It also presents information about its distribution and population status. The review emphasizes the challenges faced by C. rotundicauda and proposes a conservation framework that involves the participation of local residents to facilitate conservation efforts. Collaboration between local residents and communities is proposed to protect and monitor the mangrove ecosystem. Additionally, this framework can support field research, protect C. rotundicauda juveniles and other species, and ensure the livelihood of local residents through participation in carbon trading markets and eco-industries such as eco-farming and eco-tourism.

Intelligent sensing based on active micro/nanomotors.

In the microscopic world, synthetic micro/nanomotors (MNMs) can convert a variety of energy sources into driving forces to help humans perform a number of complex tasks with greater ease and efficiency. These tiny machines have attracted tremendous attention in the field of drug delivery, minimally invasive surgery, in vivo sampling, and environmental management. By modifying their surface materials and functionalizing them with bioactive agents, these MNMs can also be transformed into dynamic micro/nano-biosensors that can detect biomolecules in real-time with high sensitivity. The extensive range of operations and uses combined with their minuscule size have opened up new avenues for tackling intricate analytical difficulties. Here, in this review, various driving methods are briefly introduced, followed by a focus on intelligent detection techniques based on MNMs. And we discuss the distinctive advantages, current issues, and challenges associated with MNM-based intelligent detection. It is believed that the future advancements of MNMs will greatly impact the diagnosis, treatment, and prevention of diseases.

The effect of hepatic stellate cell derived-IL-11 on hepatocyte injury in hepatic fibrosis.

AIMS: This study aimed to elucidate the role of Interleukin-11 (IL-11) in hepatic fibrosis (HF) and its potential as a therapeutic target for HF treatment. MATERIALS AND METHODS: We investigated IL-11 expression in patients with varying degrees of liver injury through ELISA and immunohistochemistry. A CCl4-induced HF mouse model was constructed to study IL-11 expression and cell apoptosis using Western blotting (WB) and other techniques. The expression of IL-11 was silenced using rAAV8 in the mouse model. In vitro stimulation of hepatic stellate cells (LX-2) with TGF-ß1, and of LO-2 cells with exogenous IL-11, were performed. Cell supernatants of TGF-ß1-stimulated LX-2 were used to culture LO-2 cells, with apoptosis monitored via flow cytometry and WB. KEY FINDINGS: Increased IL-11 levels were observed in patients and the HF mouse model, with silencing reducing IL-11 expression. In vitro experiments revealed increased endogenous IL-11 in TGF-ß1-stimulated LX-2 cells and an increase in apoptotic index, IL11RA, and gp130 in IL-11-stimulated LO-2 cells. Cell apoptosis was reduced in the siRNA/IL11, siRNA/IL11RA, and anti-IL11 groups. WB and immunohistochemistry results showed upregulated p-JNK, p-ERK, and p-P53 expressions in the CCl4-induced HF mouse model and IL-11-treated LO-2 cells. SIGNIFICANCE: Our findings suggest IL-11 enhances LX-2 cell activation and proliferation, and promotes LO-2 cell apoptosis through JNK/ERK signaling pathways. This suggests that targeting IL-11 secretion may serve as a potential therapeutic strategy for HF, providing a foundation for its clinical application in HF treatment.

Enantioselective synthesis of 3a-azido-pyrroloindolines by copper-catalyzed asymmetric dearomative azidation of tryptamines.

Copper-catalyzed asymmetric dearomative azidation of tryptamines using azidobenziodoxolone as an azidating reagent was developed, which affords a variety of 3a-azido-pyrroloindolines in good to high enantioselectivities under mild reaction conditions. The azides could be readily transformed into the corresponding 3a-amino-pyrroloindolines via reduction and 1,2,3-triazole derivatives via a click reaction.

Azidobenziodazolones as Azido Sources for the Enantioselective Copper-Catalyzed Azidation of N-Unprotected 3-Trifluoromethylated Oxindoles.

Both azido (N3) and trifluoromethyl (CF3) groups are key moieties of numerous valuable molecules that are extensively applied in drug discovery, chemical biology, and synthetic chemistry. However, the asymmetric construction of chiral quaternary stereocenters bearing both N3 and CF3 groups is still unexplored. Herein, we report a kind of bench-stable and easily adjustable benziodazolone-based azidating reagents. These reagents were used to achieve an enantioselective copper-catalyzed azidation of N-unprotected 3-trifluoromethylated oxindoles to provide diverse enantioenriched 3-N3-3-CF3 oxindoles.

Simple and Versatile Nitrooxylation: Noncyclic Hypervalent Iodine Nitrooxylating Reagent.

Organic nitrates are broadly applied as pharmaceuticals (acting as efficient nitric oxide donor), energetic materials, building blocks in organic synthesis, etc. However, practical and direct methods to access organic nitrates efficiently are still rare, mainly due to the lack of powerful nitrooxylating reagents. Herein, we report bench-stable and highly reactive noncyclic hypervalent iodine nitrooxylating reagents, oxybis(aryl-λ3 -iodanediyl) dinitrates (OAIDNs, 2), which are prepared just by using aryliodine diacetate and HNO3 . The reagents are used to achieve a mild and operationally simple protocol to access diverse organic nitrates. By employing of 2, zinc-catalyzed regioselective nitrooxylation of cyclopropyl silyl ethers is realized efficiently to access the corresponding ß-nitrooxy ketones with high functional-group tolerance. Moreover, a series of direct and catalyst-free nitrooxylations of enolizable C-H bonds are carried out smoothly to afford the desired organic nitrates within minutes by just mixing the substrates with 2 in dichloromethane.

Inhibition of circular RNA ASPH reduces the proliferation and promotes the apoptosis of hepatic stellate cells in hepatic fibrosis.

Circular RNAs (circRNAs) are a newly identified form of non-coding RNA that play a crucial role in various pathological processes. However, the expression profile and function of circRNAs in hepatic fibrosis (HF) remain largely unknown. In this study, we showed that a novel circRNA ASPH (circASPH) mediates HF by targeting the miR-139-5p/Notch1 axis. We investigated the expression profile of circRNAs in hepatocyte exosomes of mice with HF using circRNA-sequencing and found significant upregulation of circASPH. Loss- and gain-of-function analysis of circASPH was performed to assess its role in HF. Furthermore, we performed luciferase reporter assay, RNA pull-down, and fluorescence in situ hybridization analyses and confirmed that circASPH directly binds to miR-139-5p. We also found that circASPH was upregulated in liver fibrogenesis. Downregulation of circASPH expression inhibited hepatic stellate cell (HSC) activation and proliferation, induced apoptosis, and attenuated mouse liver fibrogenic injury. Mechanistically, circASPH directly targeted miR-139-5p to regulate the expression of Notch1 in HF. Thus, downregulation of circASPH may suppress the activation of HSCs and HF through the circASPH/miR-139-5p/Notch1 axis. Our findings indicated that circASPH may be a potential biomarker for HF diagnosis and therapy.

Myc-mediated circular RNA circMcph1/miR-370-3p/Irak2 axis is a progressive regulator in hepatic fibrosis.

AIMS: Treating hepatic fibrosis (HF) is a major challenge worldwide. However, the biological functions and regulatory mechanisms of circular RNAs (circRNAs) remain unclear in HF. The present study aimed to elucidate the novel role of circMcph1 in HF. MAIN METHODS: HF mouse model was established by injecting CCl4 intraperitoneally and validated using hematoxylin and eosin staining, immunohistochemistry, and serological tests in vivo. RAW264.7 cells were treated with lipopolysaccharide (LPS) and interferon-γ (IFN-γ) in vitro inflammatory damage model. Gel electrophoresis, DNA sequencing, RNase R and actinomycin D treatment, random 6 primers and oligo dT primers assay, nuclear and cytoplasmic fractionation assay, and fluorescence in situ hybridization were performed to identify the characteristics of circMcph1. Functional assays such as ELISA, flow cytometry, and adeno-associated virus administration in vivo and liposome delivery gene therapy in vitro were used to determine the functional effects of circMcph1/miR-370-3p/interleukin-1 receptor-associated kinase 2 (Irak2) axis. Mechanistic assays such as luciferase reporter analysis, and chromatin immunoprecipitation revealed the molecular mechanism of the Myc/circMcph1/miR-370-3p/Irak2 axis in HF. KEY FINDINGS: CircMcph1 expression was upregulated in liver tissues and primary Kupffer cells of CCl4-induced HF mice, as well as in LPS and IFN-γ-treated RAW264.7 cells. Knockdown of circMcph1 ameliorated liver fibrogenesis and inflammatory damage in HF mice and reduced the inflammatory response in LPS and IFN-γ-treated RAW264.7 cells. Mechanically, circMcph1 mediated by Myc regulated the expression of Irak2 by sponging miR-370-3p in HF. SIGNIFICANCE: The study findings suggested that the Myc/circMcph1/miR-370-3p/Irak2 axis might be a novel identifier and therapeutic target for HF.

[Relationship between economy and ecology of Pearl River Delta Urban Agglomeration based on ecological footprint of net primary productivity]. / 基于生态足迹-å‡€åˆçº§ç”Ÿäº§åŠ›çš„ç ä¸‰è§’åŸŽå¸‚ç¾¤ç»æµŽä¸Žç”Ÿæ€çš„å ³ç³».

With the acceleration of regional economic integration, human activities have played an increasingly crucial role in regional sustainable development. In this study, MODIS remote sensing data and ecological footprint of net primary productivity (EF-NPP) were leveraged to calculate the equivalence factor and yield factor of the six major biologically productive land areas in the Pearl River Delta Urban Agglomeration. We analyzed the changes in per capita ecological footprint, per capita ecological carrying capacity, natural resource utilization efficiency and ecological moderate population from 2000 to 2020. Results showed that the per capita ecological footprint in the Pearl River Delta Urban Agglomeration continued to rise from 2000 to 2020. The ecological occupation of energy land was the highest. The ecological footprint was high in west, low in middle, and higher in northwest of the study area. The per capita ecological carrying capacity was relatively high in Zhaoqing and Jiangmen and low in Shenzhen, Dongguan, Foshan and Zhongshan. The gap between the ecological moderate population and the regional actual population widened over time, reaching 30.62 million in 2020. The regional actual population was much larger than the ecological moderate population, indicating huge population pressure. The natural resource utilization efficiency of the three main industries was high. The economic benefits created by the per capita ecological footprint increased by 36800 yuan·hm-2 during the research period, with an average annual growth rate of 1800 yuan·hm-2. The growth rate of the tertiary industry was the highest. Therefore, the results could provide reference for the study on natural resource utilization efficiency in medium and small-scale regions.

Effects of Microplastics on Immune Responses of the Yellow Catfish Pelteobagrus fulvidraco Under Hypoxia.

Compared with marine organisms, research on microplastics (MPs) in freshwater organisms is still less although MPs have been widely found in the freshwater ecosystem. Hypoxia is a ubiquitous issue in freshwater aquaculture, and under such scenarios, the toxic effects of MPs on typical aquaculture fish need to be clarified. In this study, we studied the effects of MPs (polystyrene) on specific growth rate (SGR), hypoxia-inducible factor-1α (HIF-1α), tumor necrosis factor-α (TNF-α), interleukin-8 (IL-8), and interferon (IFN) in the yellow catfish (Pelteobagrus fulvidraco) under hypoxic conditions. After 15 days of exposure, the SGR was not affected by MPs or hypoxia. MPs significantly increased the expressions of HIF-1α and TNF-α but inhibited the expression of IFN at high concentration MPs under normoxia. However, hypoxia significantly inhibited the expression of IL-8 and TNF-α under high MP concentration and low MP concentration, respectively. In addition, MPs had significant concentration-dependent inhibitory effects on IFN under hypoxia. Surprisingly, a positive correction between HIF-1α and TNF-α was found in fish. Although hypoxia might alleviate the effects of MPs with low concentrations, the interaction of hypoxia and MPs aggravated the negative effects of MPs on immune factors at high concentration MPs. This study provided new insight into the complex effects of hypoxia and MPs on aquatic organisms, and future studies should focus on the cellular pathways of immune cells in fish. Given that MPs could induce the immune response in fish, considerations should be paid to the impacts of MPs on freshwater aquaculture, and hypoxia should be taken into consideration when evaluating the effects of MPs.

ITCH regulates oxidative stress induced by high glucose through thioredoxin interacting protein in cultured human lens epithelial cells.

Thioredoxin (Trx) is an important protein that controls oxidative damage in almost all eukaryotic cells. Trx interaction protein (Txnip) has been reported to negatively regulate the bioavailability of Trx and inhibit its biological function. The E3 ubiquitin ligase ITCH can specifically degrade Txnip via ubiquitination. The apoptosis of human lens epithelial cells (HLECs), which are highly sensitive to redox caused by oxidative stress, is a significant factor for the development of sugar cataract in a high­glucose environment. However, whether Trx, Txnip and ITCH contribute to the progression of sugar cataracts and the underlying mechanisms remain unknown, and thus, identifying these were the aims of the present study. The present results suggested that the expression levels of Trx, Txnip and ITCH in HLECs cultured with different glucose concentrations were detected by reverse transcription­quantitative PCR and western blotting, and the apoptotic rate of the cells was detected by flow cytometry and superoxide detection assay. The interaction between ITCH and Txnip was determined by co­localization immunofluorescence and co­immunoprecipitation. In addition, a vector and small interfering RNA of ITCH were transfected to overexpress and knockdown ITCH, respectively, to alter the expression of downstream proteins and cell apoptosis. It was found that Txnip was highly expressed in cultured HLECs in high­glucose environment, and the antioxidative function of Trx was restricted and suppressed, thus promoting apoptosis. The overexpression of ITCH increased the expression of Trx and decreased oxidative stress and apoptosis by decreasing Txnip in cultured HLECs, while downregulation of ITCH significantly decreased the expression of Trx and enhanced oxidative stress and apoptosis. Therefore, the present results indicated that ITCH could regulate the apoptosis of HLECs that were cultured in high­glucose concentration and that it may be a treatment target for sugar cataract.

Argon Laser Peripheral Iridoplasty and Argon Laser Pupilloplasty: Alternative Management for Medically Unresponsive Acute Primary Angle Closure.

OBJECTIVE: To introduce the combined laser technique, argon laser peripheral iridoplasty (ALPI) and argon laser pupilloplasty (ALPP), in the management of medically unresponsive acute primary angle closure (APAC). DESIGN: Retrospective study. METHODS: We retrospectively reviewed the records of 23 patients (27 eyes) with APAC, who were applied ALPI and ALPP when traditional treatment failed. The visual acuity and intraocular pressure (IOP) were monitored before surgery and at 1, 2, 12, 24, and 48 h after surgery. Additionally, the angle-opening status was monitored before surgery and 48 h after the treatment by using an ultrasonic biological microscope (UBM), and the presurgical and postsurgical cornea edema statuses were observed by using a slit lamp. We also documented the complications of laser treatment. RESULTS: For the ALPI + ALPP laser-effective group, the presurgical IOP was 52.1 ± 9.3 mmHg and the postsurgical IOP was 37.6 ± 10.9 mmHg (1 h), 28.4 ± 12.4 mmHg (2 h), 19.9 ± 9.0 mmHg (6 h), 16.8 ± 7.3 mmHg (12 h), 15.9 ± 5.9 mmHg (24 h), and 14.9 ± 5.0 mmHg (48 h), with statistically significant differences (p < 0.05) in each time point. It was observed in all the patients that the corneal edema alleviated, the angles opened, and visual acuity recovered with varying degrees at 48 h after applying combined laser treatment. For the ALPI + ALPP laser-ineffective group, further interventions were taken. Definite treatment was given in both groups to maintain the long-term IOP control. CONCLUSIONS: Although the combination of ALPI and ALPP is a temporizing therapeutic strategy for APAC, it is effective in relieving pupillary block which is unresponsive to miotic agents, opening the closed angle to a certain extent, restoring the transparency of cornea, and reducing IOP to a safe level for further definitive treatment.

Nucleophilic Substitution of gem-Difluoroalkenes with TMSNu Promoted by Catalytic Amounts of Cs2CO3.

The efficient and practical nucleophilic cyanation and trifluoromethylation with appropriate trimethylsilyl nucleophiles were developed. Catalytic amounts of cheap and nontoxic Cs2CO3 were used to maintain a sufficiently high concentration of nucleophilic anion (CN- or CF3-) which could begin the catalytic cycle. The present methodologies provide diverse functionalized monofluoroalkenes bearing a cyano and trifluoromethyl group with excellent to moderate stereoselectivities.

miR-211 promotes lens epithelial cells apoptosis by targeting silent mating-type information regulation 2 homolog 1 in age-related cataracts.

AIM: To detect the expression of miR-211 in age-related cataract tissue, explore the effects of miR-211 on lens epithelial cell proliferation and apoptosis, and identify its target gene. METHODS: This study used real-time quantitative polymerase chain reaction (RT-qPCR) to measure the expression of miR-211 and its predicted target gene [silent mating-type information regulation 2 homolog 1 (SIRT1)] in 46 anterior lens capsules collected from age-related cataract patients. Human lens epithelial cell line (SRA01/04) cells were transfected with either miR-211 mimics, mimic controls, miR-211 inhibitors or inhibitor controls, 72h after transfection, miRNA and protein expression of SIRT1 were measured using RT-qPCR and Western blotting; then cells were exposed to 200 µmol/L H2O2 for 1h, whereupon cell viability was measured by MTS assay, caspase-3 assay was performed. Dual luciferase reporter assay was performed to verify the relationship between miR-211 of SIRT1. RESULTS: Compared to the control group, expression of miR-211 was significantly increased (P<0.001), the miRNA and protein expression of SIRT1 were significantly decreased (P<0.001) in the anterior lens capsules of patients with age-related cataracts. Relative to the control group, SIRT1 miRNA and protein levels in the miR-211 mimic group were significantly reduced, cell proliferation activity significantly decreased, and caspase-3 activity was significantly increased (P<0.001). In the miR-211 inhibitor group, SIRT1 miRNA and protein expression were significantly increased, cell proliferation activity significantly increased, and caspase-3 activity was significantly decreased (P<0.001). A dual luciferase reporter assay confirmed that SIRT1 is a direct target of miR-211. CONCLUSION: miR-211 is highly expressed in the anterior lens capsules of patients with age-related cataracts. By negatively regulating the expression of SIRT1, miR-211 promotes lens epithelial cell apoptosis and inhibits lens epithelial cell proliferation.

miR-211 regulates the antioxidant function of lens epithelial cells affected by age-related cataracts.

AIM: To investigate the effects and mechanism of miR-211 in mediating the antioxidant function of lens epithelial cells affected by age-related cataracts. METHODS: Real-time quantitative polymerase chain reaction (RT-qPCR) was used to detect miR-211 expression in the anterior lens capsules of healthy people, the anterior lens capsules of patients with age-related cataracts, and human epithelial cell line (SRA01/04) cells exposed to oxidative stress. A 2', 7'-dichloro-fluorescein diacetate (DCFH-DA) probe was used to measure the levels of endogenous reactive oxygen species (ROS) in human lens epithelial cells (hLECs) exposed to 400 µmol/L H2O2 for 1h. SRA01/04 cells were transfected with either miR-211 mimics, mimic controls, miR-211 inhibitors or inhibitor controls. After 72h, these cells were exposed to 400 µmol/L H2O2 for 1h, then p53 and Bax mRNA expression were measured using RT-qPCR. p53 and Bax protein expression were also measured by Western blotting analysis. Finally, cell viability was assessed using an MTS assay. RESULTS: Compared to the control group, expression of miR-211 in the anterior lens capsules of age-related cataract patients and in SRA01/04 cells exposed to oxidative stress was significantly increased (P<0.001). Levels of endogenous ROS were significantly elevated in hLECs exposed to oxidative stress (P<0.001). Compared to the mimic control group, the hLECs in the miR-211 mimic group expressed significantly higher levels of p53 and Bax mRNA and protein while cell viability was significantly reduced (P<0.001). Conversely, p53 and Bax mRNA and protein expression were significantly reduced in the miR-211 inhibitor group as compared to the control group, while the cells in this group had much higher levels of cell viability (P<0.001). CONCLUSION: miR-211 is upregulated in the anterior lens capsules of age-related cataract patients. miR-211 decreased the antioxidative stress capacity of lens epithelial cells by upregulating p53 and Bax, while inhibiting cell proliferation and repair. This finding suggests that miR-211 may play a key role in the development of age-related cataracts.

miR-24-p53 pathway evoked by oxidative stress promotes lens epithelial cell apoptosis in age-related cataracts.

MicroRNA-24 (miR-24) serves an important role in cell proliferation, migration and inflammation in various types of disease. In the present study, the biological function and molecular mechanism of miR­24 was investigated in association with the progression of age­associated cataracts. To the best of our knowledge the present study is the first to report that the expression of miR­24 was significantly increased in human anterior lens capsules affected by age­associated cataracts as well as lens epithelial cells (LECs) exposed to oxidative stress. Overexpression of miR­24 induced p53 expression and p53 was verified as a direct target of miR­24. Overexpression of miR­24 enhanced LEC death by directly targeting p53. The present study revealed that oxidative stress induced the upregulation of miR­24 and enhanced LEC death by directly targeting p53. These results suggest that the miR­24­p53 signaling pathway is involved in a novel mechanism of age­associated cataractogenesis and miR­24 may be a useful therapeutic target for age-associated cataracts.

Aptamer-functionalized Fe3 O4 magnetic nanoparticles as a solid-phase extraction adsorbent for the selective extraction of berberine from Cortex phellodendri.

The extraction adsorbent was fabricated by immobilizing the highly specific recognition and binding of aptamer onto the surface of Fe3 O4 magnetic nanoparticles, which not only acted as recognition elements to recognize and capture the target molecule berberine from the extract of Cortex phellodendri, but also could favor the rapid separation and purification of the bound berberine by using an external magnet. The developed solid-phase extraction method in this work was useful for the selective extraction and determination of berberine in Cortex phellodendri extracts. Various conditions such as the amount of aptamer-functionalized Fe3 O4 magnetic nanoparticles, extraction time, temperature, pH value, Mg2+ concentration, elution time and solvent were optimized for the solid-phase extraction of berberine. Under optimal conditions, the purity of berberine extracted from Cortex phellodendri was as high as 98.7% compared with that of 4.85% in the extract, indicating that aptamer-functionalized Fe3 O4 magnetic nanoparticles-based solid-phase extraction method was very effective for berberine enrichment and separation from a complex herb extract. The applicability and reliability of the developed solid-phase extraction method were demonstrated by separating berberine from nine different concentrations of one Cortex phellodendri extract. The relative recoveries of the spiked solutions of all the samples were between 95.4 and 111.3%, with relative standard deviations ranging between 0.57 and 1.85%.

Detection of Aß oligomers based on magnetic-field-assisted separation of aptamer-functionalized Fe3O4 magnetic nanoparticles and BaYF5:Yb,Er nanoparticles as upconversion fluorescence labels.

A sensitive and stable bioassay for the detection of Aß oligomer (Aßo), a potentially promising candidate biomarker for Alzheimer's disease (AD) diagnosis, was developed using Fe3O4 magnetic nanoparticles (MNPs) as the recognition and concentration elements and BaYF5:Yb,Er upconversion nanoparticles (UCNPs) as highly sensitive labels, conjugated with the Aßo aptamer (DNA1) and the complementary oligonucleotide of the Aßo aptamer (DNA2), respectively. The DNA1 hybridized with DNA2 to form the duplex structure on the surface of the MNPs/UCNPs nanocomposites probe. When the target Aßo was introduced, the aptamer DNA1 preferentially bound with Aßo and caused the dissociation of some complementary DNA2, liberating some UCNP-labeled complementary DNA2 and leading to a decreased upconversion fluorescent intensity on the surface of MNPs. The decreased fluorescence intensity of UCNPs was related to the concentration of Aßo in the range of 0.2-15nM with a detection limit of 36 pM. The developed method then was successfully applied to measure Aßo in artificial cerebrospinal fluid. Benefiting from the magnetic separation and concentration effect of MNPs, the high sensitivity of UCNPs, as well as the selectivity and stability of the aptamer, the present strategy offered valuable information related to early diagnosis of AD process.

Investigation on the aggregation behaviors and filament morphology of tau protein by a simple 90° angle light-scattering assay.

The in vitro aggregation of tau constructs was monitored by a simple 90° angle light-scattering (LS) approach which was conducted directly on fluorescence instrument. At the optimum incident wavelength (550 nm, unpolarized), the sensitivity of LS was high enough to detect tau aggregation at micromolar range. The nucleation and elongation, different events in the aggregation process of 4RMBD construct (corresponding with the four repeated units of tau Microtubule Binding Domain) could be observed by this approach, as compared with ThS fluorescence assay. The validity of this technique was demonstrated over a range of tau concentrations with different tau filaments. Linear regression of scattering light against concentration yielded the x-intercept, the critical concentrations of tau constructs. The critical concentrations of 4RMBD and its S305N mutant are 5.26 µM and 4.04 µM respectively, indicating point mutation S305N, which is associated with FTDP-17, appear to enhance the heparin-induced tau aggregation in vitro. Furthermore, the slopes of concentration dependence curves, as well as the angle dependence, were discussed based on the filaments morphology examined by electron microscopy and ultrasonication experiment.