查找使用阿拉丁产品的科研文献

Exploring neuroprotective effects of Chuanzhitongluo capsule on an alzheimer’s disease rat model

Sun Yuanfang,Shao Mingguo,Du Lijing,Gan Yu,Guan Yongxia,Cheng Guoliang,Li Shasha,Jin Huizi,Li Bing,Zhang Guimin,Yan Shikai,Xiao Xue

Alzheimer’s disease (AD) poses significant challenges to public health and well-being, with current treatments often providing limited efficacy. Chuanzhitongluo capsule (CZTL) has neuroprotective effects, and is expected to be used for the treatment of AD. In this study, the chemical composition, pharmacological effects and underlying mechanisms of CZTL against AD were systematically investigated. We identified the major components of CZTL through ultra-high-performance liquid chromatography coupled with a quadrupole time-of-flight mass spectrometer. AD rat model was established via scopolamine injection, followed by the administration of CZTL at various dosages, and pharmacological effects were then systematically evaluated. Furthermore, the potential mechanisms were explored using metabolomics and immunohistochemistry. Seventeen chemical constituents were identified from CZTL. Pretreatment with CZTL led to significant improvements in cognitive function and reductions in neuronal loss among AD rats. CZTL administration decreased abnormal protein aggregates (Aβ and Tau), along with markers of oxidative stress and inflammation. Metabolomic and immunohistochemical analyses indicated that CZTL modulated nicotinamide metabolism and impacted levels of NAD+, UMP, nitric oxide, and SIRT1 activity. These results suggest that CZTL effectively mitigates cognitive deficits and neuronal loss in AD by regulating nicotinamide and SIRT1, while inhibiting oxidative stress and inflammation. This study lies in their contribution to the development of novel anti-AD therapies derived from traditional Chinese medicine, paving the way for new approaches in managing neurodegenerative diseases. Graphical abstract

An effect fluorescence sensor for arginine based on bis-cyanodistyrene Schiff-base

Huan Zhou,Xianyu Huang,Sining Zheng,Hongyu Guo,Fafu Yang

The selective detection of arginine among all kinds of amino acids is of great significance but rarely reported. In this work, a simple fluorescence sensor for sensing arginine in near aqueous media was developed based on bis-cyanodistyrene Schiff-base ( BCS ). BCS was prepared by the Schiff-base condensation of amino-cyanodistyrene derivative and bis-benzaldehyde in yield of 86 %. BCS possessed high fluorescence in near aqueous media and exhibited selective detection for arginine among all kinds of test species including six common metallic ions and twenty amino acids. The detection limitation for arginine was as low as 1.34 × 10 −7 M. BCS showed the good sensing ability in pH = 6–9 and the sensing selectivity kept stable under the interference of other species. The 1:1 binding mechanism was proposed based on the multiple intermolecular hydrogen bonds. The selective sensing ability of BCS for arginine was successfully applied on tested paper and the sample analyses of MinJiang river and adults urine. BCS was further used in the living-cell imaging experiments, suggesting the excellent fluorescence imaging property and the good detecting ability for arginine in living-cell environment. This research supplied a good method for real-time and in-situ sensing arginine in complicated environments and living bodies.

Continuous monitoring of multiple biomarkers with an ultrasensitive 3D-structured wearable biosensor

Muqun Yang,Han Wang,Jing Cheng

Chronic diseases call for routine management of frequent monitoring of specific biomarkers. Traditional in vitro diagnostics technologies suffer from complex sampling processes and long detection intervals, which cannot meet the need of continuous monitoring. Wearable devices taking advantage of compact size, rapid detection process, and small sample consumption are promising to take the place of endpoint detection, providing more comprehensive information about human health. Here, we proposed a fully integrated wearable system with an ultrasensitive 3D-structured biosensor for real-time monitoring of multiple metabolites. The 3D-structured biosensor shows wide linear ranges of 400–1,400 μM and 0.1–8 mM and high sensitivities of 460.5 and 283.09 μ A /(mM·cm 2 ) for lactate and glucose detection, respectively. We have conducted in vivo animal experiments, and the proposed wearable biosensor demonstrated high consistency with established methods. We envision that this system could provide a real-time wearable detection platform for multiple biomarker detection.

Temperature-dependent synthesis of Pd@ZIF-L catalysts via an assembly method

Hong Jiang,Songlin Xue,Yefei Liu,Weihong Xing,Rizhi Chen

The Pd@ZIF-L catalysts with uniform crosshair-star shape and a size of about 20 μm were synthesized by an assembly method, in which a two-dimensional layered zeolitic imidazolate framework-L (ZIF-L) was used as the support to immobilize Pd nanoparticles . Their catalytic activities were evaluated by the catalytic reduction of p -nitrophenol to p -aminophenol. The results highlight that the physical-chemical and catalytic properties of the Pd@ZIF-L catalysts are greatly affected by the synthesis temperature. The temperature variation can make the catalysts transform from two-dimensional flakes to zero-dimensional spheres. High temperature is beneficial for increasing Pd loading and encapsulating Pd nanoparticles within the ZIF-L matrix. However, under the temperature larger than 30 °C, the dense dia(Zn) structures are formed. Increasing Pd loading in the Pd@ZIF-L catalysts leads to a significantly higher p -nitrophenol conversion. The relative dense structure of the as-synthesized catalysts makes p -nitrophenol access the active centers difficultly and a lower catalytic activity is observed. These findings would aid the development of high-performance Pd@ZIF-L catalysts.

Optimization and Characterization of an Antioxidant Exopolysaccharide Produced by Cupriavidus pauculus 1490

Xia Mingchen,Zhang Shishi,Shen Li,Yu Runlan,Liu Yuandong,Li Jiaokun,Wu Xueling,Chen Miao,Qiu Guanzhou,Zeng Weimin

In the present study, exopolysaccharides (EPS) production by Cupriavidus pauculus 1490 was optimized by response surface methodology. The results showed that sodium gluconate (4.15 g/L), NH 4 Cl (0.52 g/L), and Na 2 HPO 4 ·12H 2 O (0.04 g/L) were the optimal medium components and concentrations. The actual EPS yield of 293.2 m g/L in the optimized medium was in close agreement with the predicted value of 283.35 m g/L. Analysis of fourier transform infrared spectroscopy indicated the EPS contained abundant functional groups, such as –OH, C=O and C–O–C, and all of them were attributed to the characteristics of polysaccharides. Mannose, glucuronic acid, glucose and xylose were detected as the main monosaccharide composition of EPS. Rheological analysis suggested that the rheogram of EPS has similar trend with Xanthan and presented the property of non-Newtonian fluid. Moreover, the addition of NaCl and KCl would partly weaken the shear stress of EPS. Three in vitro assays were conducted to evaluate the antioxidant potential of the EPS. Results demonstrated that the EPS possessed scavenging capacity on hydroxyl radical, DPPH radical and superoxide anion radical in a dose-dependent way. As indicated by above results, the EPS isolated from C. pauculus 1490 might serve as a potential antioxidant agent to be applied in nutraceutical and pharmaceutical industries.

Photochemical transformation of an iron(iii)—arsenite complex in acidic aqueous solution

Pozdnyakov Ivan P.,Ding Wei,Xu Jing,Chen Long,Wu Feng,Grivin Vjacheslav P.,Plyusnin Victor F.

Surface complexation between arsenious acid anions (As( iii )) and ferric (hydr)oxides in water is important for the transformation and transfer of inorganic arsenic species. The mechanisms of formation and the photochemistry of dissolved Fe( iii )–As( iii ) complexes in acidic aqueous solution are still unclear. Here, the photooxidation of As( iii ) in the presence of Fe( iii ) ions in acidic media has been investigated by laser flash and steady-state photolysis. At low arsenite concentrations (<1 mM), As( iii ) is oxidized by the ˙OH radical generated by photolysis of the FeOH 2+ complex. At higher arsenite concentrations (>10 mM), photoactive Fe( iii )–As( iii ) complexes are formed ( ϕ 308 Fe ≈ 0.012). At all arsenite concentrations, a white FeAsO 4 colloid is formed during As( iii ) photolysis in the presence of Fe( iii ) ions. Solid Fe( iii )–As( iii ) complexes have been prepared and characterized, and the photochemical transformation of As( iii ) into As( v ) in solid Fe( iii )–As( iii ) complexes has been confirmed. These findings are important for a better understanding of the evolution of As( iii ) species under environmental conditions and should provide guidance for detoxification of As( iii )-polluted water systems.

CVD graphene as an electrochemical sensing platform for simultaneous detection of biomolecules

Wang Xiaodan,Gao Delan,Li Mingji,Li Hongji,Li Cuiping,Wu Xiaoguo,Yang Baohe

The development of electrochemical biosensors for the simultaneous detection of ascorbic acid (AA), dopamine (DA), uric acid (UA), tryptophan (Trp), and nitrite ( \({{\rm{NO}}}_{2}^{-}\) ) in human serum is reported in this work. Free-standing graphene nanosheets were fabricated on Ta wire using the chemical vapor deposition (CVD) method. CVD graphene, which here served as a sensing platform, provided a highly sensitive and selective option, with detection limits of AA, DA, UA, Trp, and \({{\rm{NO}}}_{2}^{-}\) of 1.58, 0.06, 0.09, 0.10, and 6.45 μM (S/N = 3), respectively. The high selectivity of the electrode is here explained by a relationship between the bandgap energy of analyte and the Fermi level of graphene. The high sensitivity in the oxidation current was determined by analyzing the influence of the high surface area and chemical structure of free-standing graphene nanosheets on analyte adsorption capacity. This finding strongly indicates that the CVD graphene electrode can be used as a biosensor to detect five analytes in human serum.

Enhanced Oxidation of Xylene Using Plasma Activation of an Mn/Al2O3 Catalyst

Zuliang Wu,Weili Zhou,Zhoubin Zhu,Xiaodong Hao,Xuming Zhang

Preparation and characterization of an effective microwave absorbent: RGO-MoS2-Fe3O4 nanocomposite

Ding Xiao,Fan Guang,Huang Yi,Wang Jianguo

Reduced graphene oxide-molybdenum disulfide (RGO-MoS 2 ) loaded Fe 3 O 4 nanoparticles composite (RGO-MoS 2 -Fe 3 O 4 ) is prepared via two-step hydrothermal reaction. RGO-MoS 2 possesses three dimension architecture structures. This structure can prevent RGO and MoS 2 nanosheets restacked together and provide substrates for the Fe 3 O 4 nanoparticle decoration. The sizes of Fe 3 O 4 are in the range of 5–20 nm. As a microwave absorbent: the minimum reflection loss (R L ) value is -47.67 dB at 17.44 GHz when the thickness is only 1.5 mm. The absorption bandwidth (R L  < −10 dB) can reach 4.72 GHz with the thickness is 1.7 mm. Compared with the previously reported literature, RGO-MoS 2 -Fe 3 O 4 nanocomposite exhibits excellent microwave absorption performance and can be served as an light-weight microwave absorber.

Preparation and simultaneous adsorption of an organobentonite towards phenol and Cr(VI)

Ruihua Huang,Bo Wang,Bingchao Yang,Dongsheng Zheng,Zengqiang Zhang

An adsorbent was prepared from bentonite modified by hexadecyltrimethylammonium bromide (HDTMAB) and N-2-hydroxypropyl trimethyl ammonium chloride chitosan (HTCC). This adsorbent was named as HDTMAB–HTCC bentonite. It would be used for the simultaneous adsorption of phenol and Cr(VI) from aqueous solution. By the method of single-factor experiment, the optimum preparation conditions of HDTMAB–HTCC bentonite were obtained. For bentonite (5 g), 1.0 g HDTMAB and 0.5 g HTCC were adopted as the modifying reagents. The reaction was carried out for 2 h at 80°C. The removals towards phenol and Cr(VI) enhanced with the increase in the amount of adsorbent dosage. The relatively high removals towards phenol and Cr(VI) occurred at a pH value of 1.5 or so. During the simultaneous adsorption process of phenol and Cr(VI), phenol was adsorbed by the partition from the organic phase formed by HDTMAB, while Cr(VI) was mostly adsorbed by the electrostatic interactions between HTCC and Cr(VI). No direct competition was observed due to different adsorption sites.

Preparation and properties of an organic–inorganic composite superabsorbent based on attapulgite

Guofu Ma,Feitian Ran,Enke Feng,Zhe Zhang,Ziqiang Lei

A novel, low-cost, and eco-friendly organic–inorganic composite superabsorbent is successfully prepared in aqueous solution by graft copolymerization of partially neutralized acrylic acid (AA), polyvinyl alcohol (PVA), and attapulgite (APT) using ammonium persulfate (APS) as an initiator and N,N-methylenebisacrylamide (MBA) as a crosslinker. The structure and morphology of the composite superabsorbent are characterized by means of Fourier transform infrared, X-ray diffraction, field-emission scanning electron microscopy, and transmission electron microscopy. The effects of APT content which can affect the water absorbency and the pH, ionic surfactants and different saline solution which can affect swelling capabilities of the composite superabsorbent are also investigated. The results show the composite superabsorbent give the best absorption up to 680 g/g and 53 g/g in distilled water and 0.9 wt% NaCl solution, high water absorbency over a wide pH range of 4–10, high swelling capacity in anionic surfactant than that of cationic solution, which makes it promising for potential applications in modern agriculture and horticulture. On the other hand, the composite superabsorbent can be used for removing multivalent metal ions.

Efficient Production of Epoxy-Norbornane from Norbornene by an Engineered P450 Peroxygenase

Yu Yan,Chenni Zheng,Wei Song,Jing Wu,Liang Guo,Cong Gao,Jia Liu,Xiulai Chen,Meng Zhu,Liming Liu

Graphical Based on the resolved crystal structure (PDB code: 7X53), a protein engineering strategy was developed in CYP238A1 and an optimal CYP238A1 NPV variant containing a local hydrophobic “fence” at the active site was obtained, which increased the H 2 O 2 -dependent norbornene (NBE) epoxidation activity by 7.5-fold compared with that of CYP238A1 WT and switched the monooxygenase mode to the peroxygenase mode. Epoxy-norbornane (EPO-NBE) is a crucial building block for the synthesis of various biologically active heterocyclic systems. To develop an efficient protocol for producing EPO-NBE using norbornene (NBE) as a substrate, cytochrome P450 enzyme from Pseudomonas putida (CYP238A1) was examined and its crystal structure (PDB code: 7X53) was resolved. Molecular mechanism analysis showed a high energy barrier related to iron-alkoxy radical complex formation. Therefore, a protein engineering strategy was developed and an optimal CYP238A1 NPV variant containing a local hydrophobic “fence” at the active site was obtained, which increased the H 2 O 2 -dependent epoxidation activity by 7.5-fold compared with that of CYP238A1 WT . Among the “fence”, Glu255 participates in an efficient proton transfer system. Whole-cell transformation using CYP238A1 NPV achieved an EPO-NBE yield of 77.6 g ⋅ L −1 in a 30-L reactor with 66.3 % conversion. These results demonstrate the potential of this system for industrial production of EPO-NBE and provides a new biocatalytic platform for epoxidation chemistry.