Search

Objective: To explore the effects of clinical nursing pathway (CNP) on the postoperative satisfaction and quality of life (QOL) of patients with subarachnoid hemorrhage (SAH). Methods: This is a retrospective study. Eighty patients with SAH admitted to Baoding No.1 Central Hospital from June 2021 to January 2023 were prospectively divided into a observation group and a control group by random numbers. The control group was given routine nursing, and the observation group was additional given CNP. The prognosis, cognitive function, QOL, self-care ability, nursing satisfaction and the incidence of complications were compared between the two groups. Results: After CNP nursing, the GCS and MMSE scores in the observation group were higher than those in the control group 14 days, one month and six months after the operation; and the difference was statistically significant (p< 0.05). Six months after the operation, the SS-QOL and Ability of daily living (ADL) scores in both groups were significantly improved compared with those before the intervention; and the improvement in the observation group was significantly better than that in the control group; and the difference was statistically significant(p<0.05). The nursing satisfaction score in the observation group was significantly higher than in the control group. The total incidence of complications in the observation group was lower than that in the control group. Conclusions: The CNP intervention in perioperative period of SAH patients has remarkable clinical effect, can improve the pertinence and efficiency of nursing, promote patients to recover as soon as possible, significantly improve the QOL of patients, and is worthy of clinical popularization. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effect of butylphthalide combined with fasudil in the treatment of subarachnoid hemorrhage (SAH) with cerebral vasospasm (CVS) on inflammatory factors, cognitive function and vascular endothelial function. Methods: It is a retrospective study in which a total of 104 patients with SAH with CVS admitted to Baoding First Central Hospital from July 2020 to February 2022 were selected and randomly divided into two groups by drawing lots. Patients in the control group were treated with basic symptomatic treatment, while those in the observation group were treated with butylphthalide soft capsule combined with fasudil hydrochloride injection on the basis of the control group. Before and after treatment, serum neuron specific enolase (NSE), tumor necrosis factor-α(TNF-α), interleukin-8(IL-8), hypersensitive C-reactive protein (CRP), Birmingham Cognitive Screen test (BCoS) score, serum soluble intercellular adhesion molecule-1(ICAM-1), serum endothelin-1(ET-1), vascular endothelial growth factor (VEGF) levels, and endothelium-dependent vasodilation function (FMD) in the two groups were compared. Results: After treatment, the expression levels of NSE, TNF-α, IL-8 and CRP in the two groups were significantly decreased, and the expression levels of all indicators in the observation group were lower than that in the control group (p<0.05). After treatment, the scores of orientations, attention, memory, language, practice and action in the two groups were significantly increased, and the scores of all dimensions in the observation group were higher than those in the control group (p<0.05). After treatment, S-ICAM-1, ET-1, VEGF, FMD decreased in both groups, and all indicators of the observation group were lower than those of the control group, with statistically significant differences (p<0.05). Conclusion: Butylphthalide combined with fasudil therapy was found as effective in reducing inflammatory factors, ameliorating cognitive function and vascular endothelial function in patients with subarachnoid hemorrhage complicated with cerebral vasospasm. [ABSTRACT FROM AUTHOR]

Objective: To analyze the clinical efficacy of alprostadil combined with nimodipine in the treatment of cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH) in elderly patients. Methods: This is a retrospective study. According to different treatment methods, the elderly 100 patients with CVS after SAH hospitalized in Baoding First Central Hospital from March 2020 to May 2021 were randomly divided into control group and observation group, with 50 patients in each group. The control group was treated with nimodipine, while the observation group was additionally combined with alprostadil. The levels of inflammatory factors and hemorheological indexes were measured before and after treatment. The clinical efficacy was compared and the adverse reactions were observed of the two groups. Results: The overall clinical efficacy in the observation group (95.00%) was significantly higher than that in the control group (74.00%) (p<0.05). After treatment, serum tumor necrosis factor-α (TNF-α), interleukin-8 (IL-8), high-sensitivity C-reactive protein (hs-CRP) and hemorheological indexes such as plasma viscosity, whole blood viscosity at high shear, whole blood viscosity at low shear, hematocrit and platelet adhesion decreased significantly compared with those before treatment (p<0.05), which were more obvious in the observation group (p<0.05). During treatment, the rate of adverse reactions in the observation group was 12.00%, and that in the control group was 8.00%, without statistically significant difference between the two groups (p> 0.05). Conclusion: Alprostadil combined with nimodipine is markedly effective in the treatment of CVS after SAH in elderly patients. It can effectively reduce inflammatory factor levels and improve hemorheological indexes in patients, which is conducive to the repair of neurological function. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effect of nimodipine combined with atorvastatin calcium on the micro inflammation and oxidative stress levels in patients with cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH) and its clinical implications. Methods: A total of 80 patients with CVS caused by SAH who had been admitted to Baoding First Central Hospital from August 2021 to August 2022 were selected and randomly divided into two groups. The control group underwent conventional symptomatic treatment, while the experimental group was administered nimodipine combined with atorvastatin calcium on the basis of conventional treatment. The changes in the micro inflammatory cytokines and oxidative stress factors in the two groups were compared, as well as the differences in clinical efficacy and incidence of adverse drug reactions. Results: After treatment, the levels of inflammatory cytokines in the experimental group decreased more significantly than those in the control group (p=0.00). After treatment, the serum levels of oxidative stress factors were obviously higher in the experimental group than in the control group (p=0.00). After treatment, the total efficacy was 77.5% in the experimental group and 55% in the control group, and the difference was statistically significant (p=0.04). Conclusions: Nimodipine combined with atorvastatin calcium could significantly improve the clinical symptoms in patients with CVS after SAH, which would be beneficial, safe, and effective for the patient's recovery. [ABSTRACT FROM AUTHOR]

Glutathione (GSH) is a key biomarker closely associated with cancer, and its content varies greatly between normal cells and cancer cells. However, intracellular detection of GSH was challenging because existing probes not only have a long detection time but also have fluorescence in the blue-green region that overlaps with the biological matrix's spontaneous fluorescence, thus affecting the detection accuracy. Therefore, a new red fluorescent nano-probe was needed to rapidly and accurately detected GSH within the biological matrix. Herein, red carbon dots (R-CDs) synthesized via hydrothermal method using N-(4-amino phenyl) acetamide and 4-Bromo-1,2-diaminobenzene as precursors offer enhanced fluorescence that could be quenched by MnO 2 nanosheets (MnO 2 NS) and restored by GSH. By combining R-CDs with the AS1411 aptamer and using rolling circle amplification, a multivalent aptamer modified R-CDs assembly (Assembly@R-CDs) was created for swift cancer cell targeting. Compared to monomeric aptamer, such multivalent aptamers exhibited higher affinity and selectivity, thereby enhancing the specificity and sensitivity of detection. After the fluorescence of the multivalent assembly was quenched by MnO 2 NS (Assembly@R-CDs@MnO 2 NS), it could be restored when targeting cancer cells, which could realize the distinction between normal cells and cancer cells. The experiment showed that 4T1 cancer cells took up more Assembly@R-CDs@MnO 2 NS than L929 normal cells and generated stronger fluorescence, indicating the high selectivity for cancer cell detection. The potential of such nanosystem for tumor diagnosis combination therapy is promising, especially considering the embedding properties of anthracene drugs such as doxorubicin in DNA carriers. [Display omitted] • Red carbon dots (R-CDs) with long-wavelength emission and excellent optical properties were prepared via the hydrothermal method. • A de novo multivalent aptasensor (Assembly@R-CDs@MnO 2 NS) was designed, utilizing R-CDs with MnO 2 NS-mediated and rolling circle amplification technology. • Assembly@R-CDs@MnO 2 NS was found to be effective in discriminating between normal cells and cancer cells. [ABSTRACT FROM AUTHOR]

A fluorescence "on–off-on" strategy was established for the determination of nitrite in aqueous solution based on fluorine and nitrogen co-doped near-infrared carbon dots (NIR-CDs). NIR-CDs were prepared via one-step hydrothermal method by using N-(4-aminophenyl)-acetamide and 4,5-difluorobenzene-1,2-diamine as precursors. The photoluminescence quantum yield of NIR-CDs reaches to 17.4%, and the optimal emission peak of NIR-CDs is 675 nm under excitation of 530 nm. The Stokes shift of NIR-CDs (145 nm) is higher than that of some CDs with longer emission wavelengths. The red bathophenanthroline disulfonic acid (BPS)-Fe2+ complex can quench the fluorescence of NIR-CDs via inner filter effect and static quench modes. Nitrite can oxidize Fe2+ to produce Fe3+ in acidic environment, resulting in not only the formation of colorless and unstable BPS-Fe3+ complex but also the fluorescence recovery of NIR-CDs. This fluorescence "on–off-on" phenomenon also comes with the color variation of the mixture, resulting in both the fluorescence and the visual determination of nitrite. Under optimal conditions, this assay exhibits a good linear range from 1 to 50 μM and a low detection limit of 0.056 μM for nitrite determination. The method showed good applicability for nitrite determination in soil extract, human urine, and water samples with acceptable results. A convenient fluorescence "on–off-on" strategy for nitrite detection based on fluorine and nitrogen co-doped near-infrared carbon dots (NIR-CDs) and bathophenanthroline disulfonic acid (BPS)-Fe2+ complex was innovatively established. This probe showed a low detection limit of 0.056 μM for nitrite in authentic samples, which offered a new sight for fluorescent and visual detection of nitrite in environmental protection and human health areas. [ABSTRACT FROM AUTHOR]

A highly sensitive and selective fluorescent "on–off–on" strategy is established for the synchronous detection of Cu2+ and glutathione in aqueous solution. Red carbon dots (R-CDs) were prepared by using precursors of 4,5-difluoro-1,2-phenylenediamine and citric acid via a one-step hydrothermal strategy. R-CDs show a relatively long fluorescence lifetime of 3.47 ns under 455 nm excitation and high absolute fluorescent quantum yield of 20.1% with an excitation wavelength of 550 nm. R-CDs exhibit a marked pH-responsive fluorescence property with no significant perturbation from pH 4 to pH 13 even after five cycles. R-CDs with higher concentration of 750 μg·mL−1 exhibit no significant cytotoxicity and good biocompatibility on HeLa cells and A549 cells after incubation for 48 h. The fluorescence of R-CDs at 619 nm (excited at 550 nm) is quenched statically by Cu2+ and recovered by glutathione subsequently, resulting in a fluorescent "on–off–on" assay for the synchronous detection of Cu2+ and glutathione. Under optimal conditions, the linear response covers the Cu2+ concentration range of 1 to 50 μM and the glutathione concentration range of 1 to 70 μM. Detection limits of Cu2+ and glutathione are 0.16 and 0.41 μM, respectively. This fluorescent probe is applied to the determination of Cu2+ and glutathione in authentic samples with satisfying results. Such an assay broadens the potential application of CDs in environmental areas and clinical therapy fields. [ABSTRACT FROM AUTHOR]

A one-pot hydrothermal synthesis of manganese-doped carbon dots (Mn-CDs) is reported for fluorescent "on-off-on" determination of Mn(VII) and L-ascorbic acid (L-AA) in aqueous solution and living cells. Mn-CDs were prepared by using sulfanilic acid, tetrakis(hydroxymethyl)phosphonium chloride, and Mn(II) chloride as precursors. Mn-CDs were characterized by several spectroscopic methods and microscopic techniques. Mn-CDs show distinctly long fluorescence lifetime (12.39 ± 0.07 ns) and high absolute fluorescence quantum yield (around 37%) with excitation and emission wavelengths of 362 and 500 nm, respectively. Mn-CDs exhibit no significant cytotoxicity to human cervical carcinoma HeLa cells and human embryonic kidney HEK-293T cells at 200 μg mL−1 level after 48 h incubation. The fluorescence of Mn-CDs at 500 nm (excited at 362 nm) is quenched efficiently by Mn(VII) and can be further recovered after the addition of L-AA, resulting in a fluorescent "on-off-on" assay for the determination of Mn(VII) and L-AA. Under optimal experimental conditions, the linear response covers the 3 to 150 μM Mn(VII) concentration range and the 3 to 140 μM L-AA concentration range. This method offers relatively low detection limits of 0.66 μM for Mn(VII) and 0.90 μM for L-AA. This strategy was applied to visual determination of Mn(VII) and L-AA in living HeLa cells with satisfying results. [ABSTRACT FROM AUTHOR]

The purpose of the study was to develop a facile method for the fabrication of a stable and reusable magnetic graphene composite absorbent to remove trace levels of polybrominated diphenyl ethers in water treatment. The poly cationic Fe3O4@PDDA (poly(diallyldimethyl ammonium chloride) (PDDA)) core-shell structured nanoparticles were first synthesized, and then, DNA was laid on the surface of graphene oxide (GOx) to prepare the polyanionic GOx@DNA composite. The above materials were then mixed together and adhered together through sol-gel technology. Thus, the Fe3O4@PDDA/GOx@DNA composite absorbent was prepared. Its performance was tested by disperse solid phase extraction and gas chromatography/mass spectrometric (GC/MS) for removing six kinds of indicative polybrominated diphenyl ethers (BDEs) in water samples. The removal percentages of several real samples for six kinds of BDEs (BDE17, BDE28, BDE 71, BDE 47, BDE 66, BDE 100) at the ng/mL order of magnitude were in the range of 88.2%-99.1%. The removal percentage still reached 80.0% when the adsorbent was reused at least 20 times. The results suggested that the magnetic absorbent can obviously remove trace levels of BDEs from large volumes of aqueous solutions in environmental pollution cleanup with high removal efficiency. [ABSTRACT FROM AUTHOR]

An ultrasensitive electrochemiluminescent immunoassay (ECLIA) for aflatoxins M1 (ATM1) in milk using magnetic Fe3O4-graphene oxides (Fe-GO) as the absorbent and antibody-labeled cadmium telluride quantum dots (CdTe QDs) as the signal tag is presented. Firstly, Fe3O4 nanoparticles were immobilized on GO to fabricate the magnetic nanocomposites, which were used as absorbent to ATM1. Secondly, aflatoxin M1 antibody (primary antibody, ATM1 Ab1), was attached to the surface of the CdTe QDs-carbon nanotubes nanocomposite to form the signal tag (ATM1 Ab1/CdTe-CNT). The above materials were characterized. The optimal experimental conditions were obtained. Thirdly, Fe-GO was employed for extraction of ATM1 in milk. Results indicated that it can adsorb ATM1 efficiently and selectively within a large extent of pH from 3.0 to 8.0. Adsorption processes reached 95% of the equilibrium within 10 min. Lastly, the ATM1 with a serial of concentrations absorbed on Fe-GO was conjugated with ATM1 Ab1/CdTe-CNT signal tag based on sandwich immunoassay. The immunocomplex can emit a strong ECL signal whose intensity depended linearly on the logarithm of ATM1 concentration from 1.0 to 1.0 × 105 pg/mL, with the detection limit (LOD) of 0.3 pg/mL (S/N =3). The method was more sensitive for ATM1 detection compared to the ELISA method. Finally, ten samples of milk were tested based on the immunoassay. The method is fast and requires very little sample preparation, which was suitable for high-throughput screening of mycotoxins in food. [ABSTRACT FROM AUTHOR]

The CdTe quantum dots (QDs), graphene nanocomposite (CdTe-G) and dextran-Fe3O4 magnetic nanoparticles have been synthesized for developing an ultrasensitive electrochemiluminescence (ECL) immunoassay for Carcinoembryonic antigen 19-9 (CA 19-9) in serums. Firstly, the capture probes (CA 19-9 Ab1/Fe3O4) for enriching CA 19-9 were synthesized by immobilizing the CA 19-9's first antibody (CA 19-9 Ab1) on magnetic nanoparticles (dextran-Fe3O4). Secondly, the signal probes (CA 19-9 Ab2/CdTe-G), which can emit an ECL signal, were formed by attaching the secondary CA 19-9 antibody (CA 19-9 Ab2) to the surface of the CdTe-G. Thirdly, the above two probes were used for conjugating with a serial of CA 19-9 concentrations. Graphene can immobilize dozens of CdTe QDs on their surface, which can emit stronger ECL intensity than CdTe QDs. Based on the amplified signal, ultrasensitive antigen detection can be realized. Under the optimal conditions, the ECL signal depended linearly on the logarithm of CA 19-9 concentration from 0.005 to 100 pg/mL, and the detection limit was 0.002 pg/mL. Finally, five samples of human serum were tested, and the results were compared with a time-resolved fluorescence assay (TRFA). The novel immunoassay provides a stable, specific and highly sensitive immunoassay protocol for tumor marker detection at very low levels, which can be applied in early diagnosis of tumor. [ABSTRACT FROM AUTHOR]

An ultrasensitive portable electrochemical immunosensor for human immunodeficiency virus p24 (HIV p24) antigen detection has been developed, whereby the detection sensitivity was 1000 times higher than that of the ELISA method. Firstly, a novel HRP enzyme-antibody copolymer (EV-p24 Ab2) was synthesized through an EnVision regent (EV, a dextrin amine skeleton anchoring more than 100 molecules of HRP and 15 molecules of anti IgG), then incubated in the secondary antibody of p24. Secondly, the copolymer was immobilized on the gold nanocolloids (AuNPs) to fabricate a novel signal tag (AuNPs/EV-p24 Ab2). Subsequently, a sandwich-type immunoreaction would take place between the capture probe (silicon dioxide-coated magnetic Fe3O4 nanoparticles (MNPs) labeled with the primary p24 antibody (MNPs-p24 Ab1)), p24 (different concentrations) and the signal tag [AuNPs/EV-p24 Ab2)] to form the immunocomplex. Finally, the immunocomplex was absorbed on the surface of screen printed carbon electrode (SPCE) by a magnet and immersed in the o-hydroxyl phenol (HQ) and H2O2. The large amounts of HRP on the signal tag can catalyze the oxidation of HQ by H2O2, which can induce an amplified reductive current. Moreover, the capture probe could improve the accumulation ability of p24 and facilitate its separation from the substrate through the magnet. Under optimal conditions, the proposed immunoassay exhibited good sensitivity to p24 within a certain concentration range from 0.001 to 10.00 ng/mL, with a detection limit of 0.5 pg/mL (S/N = 3). The proposed method can be used for real-time and early detection of HIV-infected people. [ABSTRACT FROM AUTHOR]

A novel horseradish peroxidase- (HPR-) doped magnetic core-shell Fe3O4@SiO2@Au nanocomposites (Fe-Au MNPs) were employed on immunoassay for the determination of C-reactive protein (CRP) based on a electrochemical quartz crystal microbalance detector (EQCM). Firstly, the secondary CRP antibody and HRP were both immobilized on the Fe-Au MNPs (Fe-Au MNPs-anti-CRP2/HRP) as a signal tag. Secondly, the above tag and the primary antibody (anti-CRP1) in the bottom of 96-well microtiter plate were employed to conjugate with a serial of CRP concentrations to produce a sandwich immunocomplex. Thirdly, the immunocomplex solution was subsequently exposed to 3, 3' -diaminobenzidine (DAB) in the presence of H2O2, resulting in an insoluble product. When the precipitation solution was dripped on EQCM, it can achieve a decrease of frequency of crystal (Δf). The amount of Δf was proportional to (CRP) from 0.003 to 200 ng mL-1 with a low detection limit of 1 pg mL-1. Compared with the enzyme-linked immunosorbent assay (ELISA), the immunoassay shows greatly improved sensitivity due to the significant amount of HRP labeled on signal tag. It also has good specificity and low sample consumption, which is expected to be a benefit for the CRP screening in early diagnosis of cardiovascular disease. [ABSTRACT FROM AUTHOR]

A novel strategy is presented for sensitive detection of alfa-fetoprotein (AFP), using a horseradish peroxidase (HRP)-functionalized Envision antibody complex (EVC) as the label. The Envision-AFP signal antibody copolymer (EVC-AFP Ab2) was composed of a dextran amine skeleton anchoring more than 100 molecules of HRP and 15 molecules of secondary antibody, and acted as a signal tag in the immunosensor. The sensor was constructed using the following steps: First, gold electrode (GE) was modified with nano-gold (AuNPs) by electro-deposition in HAuCl4 solution. The high affinity of the AuNPs surface facilitates direct formation of a self-assembled thiolated protein G layer. Next, the coated GE was incubated in a solution of AFP capture antibody (AFP Ab1); these antibodies attach to the thiolated protein G layer through their non-antigenic regions, leaving the antigen binding sites for binding of target analyte. Following a sandwich immunoreaction, an EVC-AFP Ab2-AFP-AFP Ab1 immunocomplex was formed on the electrode surface, allowing large amounts of HRP on the complex to produce an amplified electrocatalytic current of hydroquinone (HQ) in the presence of hydrogen peroxide (H2O2). Highly amplified detection was achieved, with a detection limit of 2 pg/mL and a linear range of 0.005-0.2 ng/mL for AFP in 10 μL undiluted serum; this is near or below the normal levels of most cancer biomarker proteins in human serum. Measurements of AFP in the serum of cancer patients correlated strongly with standard enzyme-linked immunosorbent assays. These easily fabricated EVC-modified immunosensors show excellent promise for future fabrication of bioelectronic arrays. By varying the target biomolecules, this technique may be easily extended for use with other immunoassays, and thus represents a versatile design route. [ABSTRACT FROM AUTHOR]

A novel magnetic nanoparticle-based electrochemical immunoassay of carcinoembryonic antigen (CEA) was designed as a model using CEA antibody-functionalized magnetic beads [DNA/Fe3O4/ZrO2; Fe3O4 (core)/ZrO2 (shell) nano particles (ZMPs)] as immunosensing probes. To design the immunoassay, the CEA antibody and O-phenylenediamine (OPD) were initially immobilized on a chitosan/nano gold composite membrane on a glassy carbon electrode (GCE/CS-nano Au), which was used for CEA recognition. Then, horseradish peroxidase (HRP)-labeled anti-CEA antibodies (HRP-CEA Ab2) were bound to the surface of the synthesized magnetic ZMP nanoparticles as signal tag. Thus, the sandwich-type immune complex could be formed between secondary antibody (Ab2) modified DNA/ZMPs nanochains tagged by HRP and GCE/CS-nano Au. Unlike conventional nanoparticle-based electrochemical immunoassays, the recognition elements of this immunoassay included both electron mediators and enzyme labels, which obviously simplifies the electrochemical measurement process. The sandwich-type immunoassay format was used for online formation of the immunocomplex of CEA captured in the detection cell with an external magnet. The electrochemical signals derived from HRP during the reduction of H2O2 with OPD as electron mediator were measured. The method displayed a high sensitivity for CEA detection in the range of 0.008-200 ng/mL, with a detection limit of 5 pg/mL (estimated at a signal-to-noise ratio of 3). The precision, reproducibility, and stability of the immunoassay were good. The use of the assay was evaluated with clinical serum samples, and the results were in excellent accordance with those obtained using the standard enzyme-linked immunosorbent assay (ELISA) method. Thus, the magnetic nanoparticle-based assay format is a promising approach for clinical applications, and it could be further developed for the detection of other biomarkers in cancer diagnosis. [ABSTRACT FROM AUTHOR]

One novel electrochemical immunosensor was constructed by immobilizing capture antibody of alpha-fetoprotein (AFP Ab1) on a nafion/nanogold- particle modified glassy carbon electrode. With a sandwich immunoassay, one DNA-derived magnetic nanoprobe, simplified as DNA/(ZMPs--HRP-AFP Ab2)n, was employed for the detection of AFP. The fabricated procedure of the proposed biosensor was characterized by cyclic voltammetry and electrochemical impedance spectroscopy. The performance and factors influencing the performance of the biosensor were also evaluated. Under optimal conditions, the developed biosensor exhibited a well-defined electrochemical behavior toward the reduction of AFP ranging from 0.01 to 200 ng/mL with a detection limit of 4pg/mL (S/N = 3). The biosensor was applied to the determination of AFP in serum with satisfactory results. It is important to note that the sandwich nanochainmodified electro-immunosensor provided an alternative substrate for the immobilization of other tumor markers. [ABSTRACT FROM AUTHOR]

A novel electrochemical immunosensor for tumor biomarker detection based on three-dimensional, magnetic and electroactive nanoprobes was developed in this study. To fabricate the nanoprobes, negatively charged Fe3O4 nanoparticles (Fe3O4 NPs) and gold nanoparticles (Au NPs) were first loaded on the surface of multiple wall carbon nanotubes (MCNTs) which were functioned with redox-active hemin and cationic polyelectrolyte poly(dimethyldiallylammonium chloride) (PDDA). Using alpha fetoprotein (AFP) as a model analyte, AFP antibody (anti-AFP) was absorbed on the surface of Au NPs, bovine serum albumin (BSA) was then used to block sites against non-specific binding, and finally formed anti-AFP/Au NPs/Fe3O4/hemin/MCNTs named anti-AFP nanoprobes. When the target antigen AFP was present, it interacted with anti-AFP and formed an antigenantibody complex on the nanoprobe interface. This resulted in a decreased electrochemical signal of hemin for quantitative determination of AFP when immobilized onto the screenprinted working electrode (SPCE). The results showed that the nanoprobe-based electrochemical immunosensor was sensitive to AFP detection at a concentration of 0.1 to 200 ng∙mL-1 with a detection limit of 0.04 ng∙mL-1, it also demonstrated good selectivity against other interferential substances. The electroactive nanoprobes can be massively prepared, easily immobilized on the SPCE for target detection and rapidly renewed with a magnet. The proposed immunosensor is fast, simple, sensitive, stable, magnet-controlled, nontoxic, label-free and reproducible. [ABSTRACT FROM AUTHOR]

A novel supramolecular amperometric immunosensor for the determination of Human Immunodeficiency Virus antigen p24 (HIV p24) was built up using the electrostatic layer-by-layer self-assembly technique upon a gold electrode with HIV p24 antibody (antip24) being immobilized on polyelectrolyte/gold nanoparticle multilayer films. The multilayer films were composed of poly(L-lysine) (pLys) and mercaptosuccinic acid (MSA) stabilized Fe3O4(core)/gold(shell) nano particles (GMPs).The immunosensor preparation steps were monitored by X-ray fluorescence spectrometry (XRFS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In pH 6.5 PBS, after the immunosensor was incubated with HIV p24 solution at 25 °C for 5 min, the electron transfer access of FeCN is partially inhibited, which leads to a linear decrease of peak current. In addition, the performance of the immunosensor was studied in detail. It offers high-sensitivity for the detection of p24 and has good correlation for the detection of p24 in the range of 0.1 to 100.0 ng/mL with a detection limit of 0.05 ng/mL estimated at a signal to-noise ratio of 3. The proposed immunosensor was used to analyze p24 in human serum specimens and the results showed the developed immunosensor provides a promising alternative approach for detecting p24 in the early diagnosis of AIDS patients. [ABSTRACT FROM AUTHOR]

A disposable organophosphorus pesticides (OPs) enzyme biosensor based on magnetic composite nanoparticle-modified screen printed carbon electrodes (SPCE) has been developed. Firstly, an acetylcholinesterase (AChE)-coated Fe3O4/Au (GMP) magnetic nanoparticulate (GMP-AChE) was synthesized. Then, GMP-AChE was absorbed on the surface of a SPCE modified by carbon nanotubes (CNTs)/nano-ZrO2/prussian blue (PB)/Nafion (Nf) composite membrane by an external magnetic field. Thus, the biosensor (SPCE∣CNTs/ZrO2/PB/Nf∣GMP-AChE) for OPs was fabricated. The surface of the biosensor was characterized by scanning electron micrography (SEM) and X-ray fluorescence spectrometery (XRFS) and its electrochemical properties were studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The degree of inhibition (A%) of the AChE by OPs was determined by measuring the reduction current of the PB generated by the AChE-catalyzed hydrolysis of acetylthiocholine (ATCh). In pH = 7.5 KNO3 solution, the A was related linearly to the concentration of dimethoate in the range from 1.0 × 10-3-10 ng·mL-1 with a detection limit of 5.6 × 10-4 ng·mL-1. The recovery rates in Chinese cabbage exhibited a range of 88%-105%. The results were consistent with the standard gas chromatography (GC) method. Compared with other enzyme biosensors the proposed biosensor exhibited high sensitivity, good selectivity with disposable, low consumption of sample. In particular its surface can be easily renewed by removal of the magnet. The convenient, fast and sensitive voltammetric measurement opens new opportunities for OPs analysis. [ABSTRACT FROM AUTHOR]

The purpose of the present paper is to give an elementary method for the computation of the cohomology groups $$ H^{q} {\left( {X,\Omega ^{p}_{X} {\left( L \right)}} \right)} $$ , (0 ≤ q ≤ n) of an n–dimensional non–primary Hopf manifold X with arbitrary fundamental group. We use the method of Zhou to generalize the results for primary Hopf manifolds and non–primary Hopf manifold with an Abelian fundamental group. [ABSTRACT FROM AUTHOR]

Objectives: To analyze the effects of compound dextran combined with atorvastatin calcium on blood flow indexes, peroxidase 2 (Prx2) and endothelin-1 (ET-1) in patients with cerebral vasospasm (CVS) caused by subarachnoid hemorrhage (SAH). Methods: One hundred patients with CVS caused by SAH treated in Baoding No.1 Central Hospital from January 2019 to December 2020 were divided into observation group and control group. The control group was treated with atorvastatin calcium tablets, while the observation group was additionally treated with compound dextran. The hospital stays, Glasgow Outcome Scale (GOS), hemoglobin (Hb) and hematocrit (Hct) levels before and five days after treatment were recorded. The hemodynamic parameters of the middle cerebral artery (MCA) and the serum levels of Prx2 and ET-1 were detected. Results: After treatment, GOS and Hct levels in the observation group were both higher than those in the control group (P < 0.05). After treatment, the mean and peak velocities of the MCA in the observation group were significantly lower than those in the control group (P < 0.05). After treatment, the serum levels of Prx2 and ET-1 in the observation group were significantly lower compared with those in the control group (P < 0.05). However, no significant differences were found in the incidences of adverse reactions between the two groups (P > 0.05). Conclusions: Compound dextran combined with atorvastatin calcium can effectively enhance clinical efficacy, improve cerebral blood flow and reduce serum Prx2 and ET-1 levels in patients with CVS caused by SAH. [ABSTRACT FROM AUTHOR]

A convenient and ultrasensitive ratiometric fluorescent probe was innovatively developed for Hg(II) detection and trypsin activity evaluation based on carbon dots (CDs) and tetraphenylporphyrin tetrasulfonic acid (TPPS) using bovine serum albumin (BSA) as the substrate of trypsin. The ratiometric fluorescence signal arises from CDs (λem = 506 nm) and TPPS (λem = 645 nm) via an inner filter effect. Hg2+ can trigger the formation of TPPS-Mn2+ metalloporphyrin for target Hg2+ recycling amplification, while both TPPS-Hg2+ and TPPS-Mn2+ metalloporphyrins do not affect the fluorescence of CDs. Small amino acids and peptide fragments, which are the products of BSA under the digestion of trypsin, bind stronger with Hg2+ than with TPPS. The decomposition of both TPPS-Hg2+ and TPPS-Mn2+ metalloporphyrins leads to a variation in the ratiometric fluorescence signal. Under optimized conditions, this probe provided an inspiring detection limit of 0.086 nM for Hg2+ and 0.013 ng mL−1 for trypsin, which possessed acceptable sensitivity for Hg2+ detection and trypsin activity evaluation in authentic samples. This unprecedented CD-based ratiometric fluorescence proposal for ultrasensitive quantification of Hg2+ concentration and selective assessment of trypsin activity gives a new insight for designing metal ion assays or enzymatic activity bioassays under different enzymatic substrates in the near future. [ABSTRACT FROM AUTHOR]

Herein, efficient red carbon dots (R-CDs) were synthesized by one-step hydrothermal treatment of N -(4-amino phenyl) acetamide and (2,3-difluoro phenyl) boronic acid. The optimal emission peak of R-CDs was at 602 nm (under 520 nm excitation) and the absolute fluorescence quantum yield of R-CDs was 12.9%. Polydopamine, which was formed by the self-polymerization and cyclization of dopamine in alkaline condition, emitted characteristic fluorescence with peak position of 517 nm (under 420 nm excitation) and affected the fluorescence intensity of R-CDs through inner filter effect. L-Ascorbic acid (AA), which was the hydrolysis product of L-ascorbic acid-2-phosphate trisodium salt under the catalytic reaction of alkaline phosphatase (ALP), effectively prevented the polymerization of dopamine. Combined with the ALP-mediated AA production and the AA-mediated polydopamine generation, the ratiometric fluorescence signal of polydopamine with R-CDs was correlated closely with the concentration of both AA and ALP. Under optimal conditions, the detection limits of AA and ALP were 0.28 μM during linear range of 0.5–30 μM and 0.044 U/L with linear range of 0.05–8 U/L, respectively. This ratiometric fluorescence detection platform can efficiently shield the background interference of sophisticated samples by introducing a self-calibration as reference signal in a multi-excitation mode, which can detect AA and ALP in human serum samples with satisfactory results. Such R-CDs/polydopamine nanocomposite provides a steadfast quantitative information and makes R-CDs be excellent candidate for biosensors via combining target recognition strategy. [Display omitted] • R-CDs with fluorescent QY of 12.9% were synthesized through one-step hydrothermal method. • Ratiometric fluorescence probe was established based on pink R-CDs and green polydopamine via IFE. • ALP catalyzed the hydrolyzation of AAP to produce AA that inhibited the polymerization of dopamine. • Ratiometric fluorescence probe was used to detect as low as 0.28 μM of AA and 0.044 U/L of ALP. [ABSTRACT FROM AUTHOR]

The combined photothermal and chemo- therapy overcomes the limitations of single one, and enhances the therapeutic efficiency which holds broad prospects in tumor treatment. Herein, the "Lily of the valley"-like Au@RCA-AS1411 nanoplatform with polyvalent aptamers-targeted capability has been designed based on rolling circle amplification (RCA) for dual-treating of liver cancer through photothermal and chemotherapy. Polyvalent aptamers can be effectively constructed by the Au@RCA-AS1411 nanoplatform, bolstering the capacity for targeting cancer cell and reducing the toxic side effects on normal cells. Meanwhile, multiple gold nanoparticles (AuNPs) have been successfully linked to the nanoplatform via SH, which realized the aggregation of AuNPs and the photothermal conversion efficiency is improved to 69.7 %. In addition, the photothermal enhancement of Dox release was demonstrated by Au@RCA-AS1411. This nanoplatform was used to treat L929 and HepG2 cells, and found that it had no toxic and side effects on cells and had good biocompatibility. Au@RCA-AS1411 nanoplatform with polyvalent aptamers showed stronger specific targeting ability to HepG2 cells than Au@RCA without aptamers and Au@DNA-AS1411 containing only one aptamer. After laser irradiation, the survival rate of HepG2 cells in the presence of Au@RCA-AS1411 decreased to 27.8 %, which was lower than that of normal L929 cells and other controls. Encouragingly, when combined with drugs, the survival rate of HepG2 cells was significantly reduced to 11.2 %, indicating that the nanoplatform combination therapy enhanced and showed synergistic effects. [Display omitted] • Nanoplatform successfully connects gold nanoparticles into strings. • DNA loading on AuNPs does not affect their photothermal performance. • Construction of polyvalent aptamers for more precisely targeted therapy. • Chemotherapy and photothermal therapy show synergistic enhancement effects. [ABSTRACT FROM AUTHOR]

Developing multifunctional nanomedicines represents a frontier. We have engineered a high-capacity DNA vector basing rolling circle amplification for the delivery of copper sulfide nanoparticles (CuS NPs) and doxorubicin (DOX), coupled with multivalent aptamers (MA) that precisely target tumors, culminating in a multifunctional nanoplatform (RMAL 1 Cu@DOX), which combines the chemotherapy (CT)/photothermal therapy (PTT)/chemodynamic therapy (CDT). The vector (RMAL 1) boasts exceptional biocompatibility and incorporates multiple copy units, enabling the precise loading of numerous CuS NPs, forming RMAL 1 Cu which possesses a robust photothermal effect and superior Fenton-like catalytic activity, heralding a project of minimally invasive dual-mode (PTT/CDT) therapy. Furthermore, the abundance of G-C of RMAL 1 enabled effective DOX encapsulation through π-π interactions to construct RMAL 1 Cu@DOX. The MA integrated into RMAL 1 Cu@DOX is pivotal in enhancing the targeting of tumors and in preventing non-specific release of CuS and DOX, enabling an integrated CT/PTT/CDT. Data indicate that 1 nM of RMAL 1 Cu could load 270 nM of DOX with an impressive loading capacity of 77 %, and modification with MA, its tumor-targeting ability was amplified by 51-fold and significantly bolstered in vitro imaging outcomes, and the synergistic killing of B16 was as 67.3 %. This innovative nanoplatform offers a comprehensive and holistic strategy for the treatment of malignant tumors. A high-capacity DNA vector basing rolling circle amplification for the delivery of copper sulfide nanoparticles (CuS NPs) and doxorubicin (DOX), coupled with multivalent aptamers (MA) that precisely target tumors, culminating in a multifunctional nanoplatform (RMAL 1 Cu@DOX), which combines the chemotherapy /photothermal therapy/chemodynamic therapy. [Display omitted] • Nanoplatform has good biocompatibility. • The nanoplatform can significantly enhance cancer cell imaging (51 times). • Nanoplatform has excellent loading capacity for doxorubicin. • The photothermal effect of the nanoplatform is significantly enhanced. • This nanoplatform can effectively ablate cancer cells. [ABSTRACT FROM AUTHOR]

A high-performance liquid chromatography assay is described for the determination of rivanol in human plasma. Solid-phase extraction cartridges are used to extract plasma samples. Separation is done by using a C18 column. The mobile phase is a mixture of methanol–0.05% sodium dodecylsulfonate (70:30, v/v, pH 3), with the flow rate at 1.0 mL/min. UV detection of rivanol is at 272 nm. The calibration curve is linear in the concentration range of 1 x 10–8 mol/L to 1 x 10–5 mol/L with linear correlation coefficient r equal to 0.9998. The limit of detection for the assay is 3 x 10–9 mol/L, corresponding to 1.1 ng/mL. Precision, expressed as the within- and between-day coefficient of variation, is 3.3–8.1% and 4.1–9.5%, respectively, at plasma control samples of 5 x 10–8, 5 x 10–7, and 5 x 10–6 mol/L. And the recovery ranges from 94.8% to 107.2%. The selectivity of the method is confirmed. Plasma samples are stable for at least 15 days if they are stored lightproof at –20°C. This method is simple, sensitive, and accurate, and it allows for the determination ng rivanol in human plasma. It could be applied to assessing its plasma level in women receiving an intra-amniotic injection of rivanol. [ABSTRACT FROM AUTHOR]

A novel trinuclear copper(Il) complex, Cu3-L (L -- N,N,N',N',N",N"-hexakis(2-pyridyl)-l,3,5-tris(aminomethyl)benzene), exhibited efficient oxidative strand scission of plasmid DNA. The solution behavior of the complex has been studied by potentiometric titration, UV spectroscopy, and cyclic voltammetry. The data showed that there are three redox-active copper ions in the complex with three types of bound water. The complex demonstrated a moderate binding ability for DNA. Cu3-L readily cleaves plasmid DNA in the presence of ascorbate to give nicked (form II) and then linear (form III) products, while the cleavage efficiency using H2O2 is less than by ascorbate, suggesting that the cleavage mode of the trinuclear complex is somewhat different from the traditional Fenton-like catalysis. Meanwhile, Cu3-L is far more efficient than its mononuclear analogue Cu-DPA (DPA -- 2,2'-dipyridylamine) at the same [Cu2+] concentration, which suggests a possible synergy between the three or at least two Cu(ll) centers in Cu3-L that contributes to its relatively high nucleolytic efficiency. Furthermore, the presence of standard radical scavengers does not have clear effect on the cleavage efficiency, suggesting the reactive intermediates leading to DNA cleavage are not freely diffusible radicals. [ABSTRACT FROM AUTHOR]

A facile, economic, and portable test kit based on target-responsive hydrogel with smartphone detection was fabricated for the accurate determination of dichlorvos in tap water and food samples. Carbon dots (CDs) and CdTe quantum dots (QDs) embedded hydrogel were employed as indicator, and fluorescence of CdTe QDs (645 nm) was dynamically quenched by Cu2+ while that of CDs (490 nm) were non-response for Cu2+, em erging a typical ratiometric fluorescence signal. Acetylcholinesterase hydrolyzed acetylthiocholine to generate thiocholine that bound with Cu2+ strongly via S-Cu-S bond. Dichlorvos as competitive inhibitor for acetylcholinesterase prevented the generation of thiocholine, which blocked the formation of Cu-thiocholine complex and changed the ratiometric fluorescence signal. The signal of the test kit, which was recorded by smartphone's camera, was transduced by ImageJ software into the color parameter that was linearly proportional to the logarithm of dichlorvos concentration. This portable test kit showed wide linear range of 1 to 40 ppb and low detection limit of 0.38 ppb for dichlorvos. This test kit exhibited rapid sample-to-answer detection time (50 min) of dichlorvos in tap water and food samples, and the recoveries were in the range 81.3 to 111% with relative standard deviations of less than 9.1%. [ABSTRACT FROM AUTHOR]

A ratiometric fluorescent assay is fabricated for the evaluation of alkaline phosphatase (ALP) activity. This assay is composed of ionic liquid–functionalized carbon dots (IL-CDs) with blue fluorescence signal at 470 nm and 2,3-diaminophenazine (DAP) with yellow fluorescence signal at 570 nm. IL-CDs were synthesized via electrochemical method by using ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate) and ultrapure water as precursors. DAP is produced by the oxidation reaction between o-phenylenediamine and H2O2 under the catalysis of horseradish peroxidase. H2O2 is reduced by ascorbic acid which is the hydrolysis product of ascorbic acid 2-phosphate under the catalysis of ALP, finally reducing the amount of DAP. The activity of ALP is evaluated through the ratiometric fluorescent signal between IL-CDs and DAP via Förster resonance energy transfer. Under optimal experimental conditions, this ratiometric fluorescent assay has a response that covers the 0.04 to 3.2 U L−1 (12 to 960 pM) ALP activity. This assay possesses ultralow detection limit of 0.012 U L−1 (3.6 pM) for ALP and high selectivity for ALP among several enzymes. The method was used to measure ALP activity in human serum samples with satisfying results. [ABSTRACT FROM AUTHOR]

Streptococcus pneumoniae coinfection is a major cause of mortality in influenza pandemics. Growing evidence shows that uncontrolled immune response results in severe tissue damage and thereby promotes death in coinfection. Progranulin (PGRN) is widely expressed in immune and epithelial cells and exerts anti-inflammatory role in many diseases. We found that PGRN levels were significantly elevated in clinical influenza/S. pneumoniae-coinfected patients. C57BL/6 wild-type (WT) and PGRN-deficient (PGRN-/-) mice were infected with influenza virus PR8 and then superchallenged with S. pneumoniae serotype 19F. Coinfected PGRN-/- mice showed increased mortality and weight loss compared with WT mice. PGRN deficiency led to increased bacterial loads in lungs without altering influenza virus replication, suggesting a role of PGRN in decreasing postinfluenza susceptibility to S. pneumoniae coinfection. Administration of recombinant PGRN improved survival of WT and PGRN-/- mice in lethal coinfection. Additionally, loss of PGRN resulted in aggravated lung damage along with massive proinflammatory cytokine production and immune cell infiltration during coinfection. Endoplasmic reticulum stress (ERS) during influenza, and coinfection was strongly induced in PGRN-/- mice that subsequently activated apoptosis signaling pathways. Treatment of recombinant PGRN or inhibition of ERS by 4-phenylbutyrate decreased apoptosis and bacterial loads in lungs of coinfected mice. These results suggest that PGRN decreases postinfluenza susceptibility to S. pneumoniae coinfection via suppressing ERS-mediated apoptosis. Impaired bacterial clearance and increased lung inflammation are associated with the lethal outcome of coinfected PGRN-/- mice. Our study provides therapeutic implication of PGRN to reduce morbidity and mortality in influenza/S. pneumoniae coinfection. [ABSTRACT FROM AUTHOR]

Coexistence of the polymorphic hybrid-1 and hybrid-2 conformers for a given human telomeric G-quadruplex-forming sequence (htG4) complicates its fine structure identification and limits its application as a sensor element. With help from abasic site (AP site)-engineered htG4s serving as the monomorphic representatives of the two typical hybrid conformers, we found that thioflavin T (ThT) can selectively target the hybrid-2 conformer over the hybrid-1 counterpart in monomer and tandem htG4 molecules. The htG4 that solely adopts the monomorphic hybrid-2 conformer engineered by the AP site is most efficient in lighting up ThT fluorescence in K+ and a selective K+ sensor is realized with a remarkable hypersaline-tolerant capability that can work even in 30000-fold excess of Na+. At 600 mM Na+, the dynamic range for K+ detection can be extended to 30 mM with the limit of detection of 20 μM. This is the first report on the fluorescence discrimination of these two hybrid conformers of htG4 although they have long been categorized with their characteristically structural topologies. Our work will attract much interest in the development of sensors based on the monomorphic htG4 conformer since such high performance in sensor development has not been previously achieved. [ABSTRACT FROM AUTHOR]

Background: Long noncoding RNAs (lncRNAs) are related to different biological processes in non-small cell lung cancer (NSCLC). However, the possible molecular mechanisms underlying the effects of the long noncoding RNA HOXA11-AS (HOXA11 antisense RNA) in NSCLC are unknown. Methods: HOXA11-AS was knocked down in the NSCLC A549 cell line and a high throughput microarray assay was applied to detect changes in the gene profiles of the A549 cells. Bioinformatics analyses (gene ontology (GO), path- way, Kyoto Encyclopedia of Genes and Genomes (KEGG), and network analyses) were performed to investigate the potential pathways and networks of the differentially expressed genes. The molecular signatures database (MSigDB) was used to display the expression profiles of these differentially expressed genes. Furthermore, the relationships between the HOXA11-AS, de-regulated genes and clinical NSCLC parameters were verified by using NSCLC patient information from The Cancer Genome Atlas (TCGA) database. In addition, the relationship between HOXA11-AS expression and clinical diagnostic value was analyzed by receiver operating characteristic (ROC) curve. Results: Among the differentially expressed genes, 277 and 80 genes were upregulated and downregulated in NSCLC, respectively (fold change ≥2.0, P < 0.05 and false discovery rate (FDR) < 0.05). According to the degree of the fold change, six upregulated and three downregulated genes were selected for further investigation. Only four genes (RSPO3, ADAMTS8, DMBT1, and DOCK8) were reported to be related with the development or progression of NSCLC based on a PubMed search. Among all possible pathways, three pathways (the PI3K-Akt, TGF-beta and Hippo signaling pathways) were the most likely to be involved in NSCLC development and progression. Furthermore, we found that HOXA11-AS was highly expressed in both lung adenocarcinoma and squamous cell carcinoma based on TCGA database. The ROC curve showed that the area under curve (AUC) of HOXA11-AS was 0.727 (95% CI 0.663-0.790) for lung adenocarcinoma and 0.933 (95% CI 0.906-0.960) for squamous cell carcinoma patients. Additionally, the original data from TCGA verified that ADAMTS8, DMBT1 and DOCK8 were downregulated in both lung adenocarcinoma and squamous cell carcinoma, whereas RSPO3 expression was upregulated in lung adenocarcinoma and downregulated in lung squamous cell carcinoma. For the other five genes (STMN2, SPINK6, TUSC3, LOC100128054, and C8orf22), we found that STMN2, TUSC3 and C8orf22 were upregulated in squamous cell carcinoma and that STMN2 and USC3 were upregulated in lung adenocarcinoma. Furthermore, we compared the correlation between HOXA11-AS and de-regulated genes in NSCLC based on TCGA. The results showed that the HOXA11-AS expression was negatively correlated with DOCK8 in squamous cell carcinoma (r = -0.124, P = 0.048) and lung adenocarcinoma (r = -0.176, P = 0.005). In addition, RSPO3, ADAMTS8 and DOCK8 were related to overall survival and disease-free survival (all P < 0.05) of lung adenocarcinoma patients in TCGA. Conclusions: Our results showed that the gene proiles were signiicantly changed after HOXA11-AS knock-down in NSCLC cells. We speculated that HOXA11-AS may play an important role in NSCLC development and progression by regulating the expression of various pathways and genes, especially DOCK8 and TGF-beta pathway. However, the exact mechanism should be veriied by functional experiments. [ABSTRACT FROM AUTHOR]

The effect of dry-curing salt content (4% low salt (LS), 8% high salt (HS)) on lipolysis, lipid oxidation and volatile compounds in dry-cured goose was investigated in our study. The activities of acid lipase and neutral lipase increased during dry-curing, while phospholipase reached its maximum at the end of marinating. Lipoxygenase (LOX) and thiobarbituric acid reactive substances (TBARS) values increased during dry-curing and marinating then decreased during dry-ripening. Total free fatty acids (TFFA) increased at dry-curing and dry-ripening points and decreased during marinating. Total peak area of lipids derived volatile compounds (TPALDVC) and total peak area increased during entire stages. Compared to LS, HS group has higher lipolytic and LOX activities, TBARS, TFFA, unsaturated fatty acids and TPALDVC. The higher TPALDVC in HS could be attributed to higher lipid hydrolysis and oxidation during processing. [ABSTRACT FROM AUTHOR]

Since glucose biosensors are one of the most popular and widely used point-of-care testing devices, a novel electrochemical enzyme-linked immunosorbent assay (ELISA) for protein biomarkers has been developed based on a glucose detection strategy. In this study, α-fetoprotein (AFP) was used as the target protein. An electrochemical ELISA system was constructed using anti-AFP antibodies immobilized on microwell plates as the capture antibody (Ab1) and multi-label bioconjugates as signal tracer. The bioconjugates were synthesized by attaching glucoamylase and the secondary anti-AFP antibodies (Ab2) to gold nanoparticles (AuNPs). After formation of the sandwich complex, the Ab2-glucoamylase-AuNPs conjugates converted starch into glucose in the presence of AFP. The concentration of AFP can be calculated based on the linear relation between AFP and glucose, the concentration of which can be detected by the glucose biosensor. When the AFP concentration ranged from 0.05 to 100 ng/mL, a linear calibration plot (i (μA) = 13.62033 - 2.86252 logCAFP (ng/mL), r = 0.99886) with a detection limit of 0.02 ng/mL was obtained under optimal conditions. The electrochemical ELISA developed in this work shows acceptable stability and reproducibility, and the assay for AFP spiked in human serum also shows good recovery (97.0%-104%). This new method could be applied for detecting any protein biomarker with the corresponding antibodies. [ABSTRACT FROM AUTHOR]

Acquired immune deficiency syndrome (AIDS) is a severe communicable immune deficiency disease caused by the human immune deficiency virus (HIV). The analysis laboratory diagnosis of HIV infection is a crucial aspect of controlling AIDS. The p24 antigen, the HIV-1 capsid protein, is of considerable diagnostic interest because it is detectable several days earlier than host-generated HIV antibodies following HIV exposure. We present herein a new sandwich HIV p24 immunosensor based on directly electroplating an electrode surface with gold nanoparticles using chronoamperometry, which greatly increased the conductivity and reversibility of the electrode. Under optimum conditions, the electrochemical signal showed a linear relationship with the concentration of p24, ranging from 0.01 ng/mL to 100 ng/mL (R > 0.99), and the detection limit was 0.008 ng/mL. Compared with ELISA, this method increased the sensitivity by more than two orders of magnitude (the sensitivity of ELISA for p24 is about 1 ng/mL). This immunosensor may be broadly applied to clinical samples, being distinguished by its ease of use, mild reaction conditions, guaranteed reproducibility, and good anti-interference ability. [ABSTRACT FROM AUTHOR]

In this paper, Fe3O4 nanoparticles (Fe3O4 NPs) grafted carboxyl groups of multiwalled carbon nanotubes with cationic polyelectrolyte poly (dimethyldiallylammonium chloride) (PDDA) (MWCNTs-COO-/PDDA@Fe3O4), are successfully synthesized and used for the extraction of six kinds of major toxic polychorinated biphenyls (PCBs) from a large volume of water solution. The hydrophilicity of the PDDA cage can enhance the dispersibility of sorbents in water samples, and the superparamagnetism of the Fe3O4 NPs facilitate magnetic separation which directly led to the simplification of the extraction procedure. With the magnetic solid-phase extraction (MSPE) technique based on the MWCNTs-COO-/PDDA@Fe3O4 sorbents, it requires only 30 min to extract trace levels of PCBs from 500 mL water samples. When the eluate condensed to 1.0 mL, concentration factors for PCBs became over 500. The spiked recoveries of several real water samples for PCBs were in the range of 73.3-98.9% with relative standard deviations varying from 3.8% to 9.4%, reflecting good accuracy of the method. Therefore, preconcentration of trace level of PCBs by using this MWCNTs-COO-/PDDA@Fe3O4 sorbent, which are stable for multiple reuses, from water solution can be performed. [ABSTRACT FROM AUTHOR]

High concentrations of γ-tocopherol (γTCP) tend to show antioxidant, anti-inflammatory, and anticancer effects. In this study, we prepared polymer micelles under acidic conditions with a controlled release of γTCP due to the decomposition of pendant acetal bonds. First, a precursor diblock copolymer composed of poly(ethylene glycol) (PEG) and acrylic acid (AA) was prepared. This was followed by the synthesis of an amphiphilic diblock copolymer (PEG54-P(AA/VE6/γTCP29)140), incorporated into hydrophobic γTCP pendant groups attached to the main chain through an acetal bond. The prepared PEG54-P(AA/VE6/γTCP29)140 was further dispersed in water to form polymer micelles composed of hydrophobic cores that were generated from a hydrophobic block containing γTCPs and hydrophilic shells on the surface. Under acidic conditions, γTCP was then released from the core of the polymer micelles due to the decomposition of the pendant acetal bonds. In addition, polymer micelles swelled under acidic conditions due to hydration of the core. [ABSTRACT FROM AUTHOR]