Binary split fluorescent biosensor based on lettuce DNA aptamer for label-free and enzyme-free analysis of hepatitis B viral DNA.

Hepatitis B virus (HBV) acts as a severe public health threat, causing chronic liver diseases. Although the quantified evaluation of HBV infection can be obtained by estimating the capacity of the HBV DNA genome, it still lacks an effective and robust detection method without using enzymes or chemical labeling. Herein, we have designed a binary split fluorescent DNA aptasensor (bsFDA) by rationally splitting the lettuce aptamer into two functional DNA short chains and utilizing the HBV DNA segment complementary sequences (HDs). In this strategy, the bsFDA has been investigated to specifically recognize the HDs, forming a triplex DNA with the lettuce aptamer structure. Meanwhile, the turn-on fluorescence of bsFDA is obtained upon formation of a fluorescent complex between DFHO and the triplex DNA structure, allowing the enzyme-free, label-free, fast-responsive, and reliable fluorescence readout for detecting HDs and the potential HDs mutants. Moreover, bsFDA has been applied for spiked HDs analysis in different real matrixes, including human serum and cell lysate. The satisfactory recovery rates and reproducibility of the bsFDA reveal its potential detection efficacy for HDs analysis in biological samples. Overall, bsFDA holds great potential in developing functionalized aptasensors and realizing viral genome analysis in biological research.

Diagnosis of cutaneous primary nocardiosis in patients with normal immune function by metagenomic next-generation sequencing.

Nocardia primarily affects immunocompromised individuals, and Infection with Nocardia is uncommon and primary cutaneous nocardiosis caused by percutaneous inoculation is even rarer. Primary cutaneous nocardiosis remains a diagnostic challenge and should be considered in the differential diagnosis for any superficial cutaneous infection that arises in patients with normal immune function. We report a case that was diagnosed with primary cutaneous Nocardia by metagenomic next-generation sequencing technology.

Construction of a novel fluorescent DNA aptasensor for the fast-response and sensitive detection of copper ions in industrial sewage.

Heavy metal pollution poses a great threat to the ecological environment and human health. In particular, copper ions (Cu2+) play a vital role in regulating fundamental life behavior, and the homeostasis of Cu2+ is closely related to many physiological processes. The excessive accumulation of Cu2+ in the human body through food and drinking water will cause severe diseases. However, current conventional Cu2+ detection methods for evaluating the content of Cu2+ are unable to meet the complete requirements of practical Cu2+ analysis in the practical aquatic environment. In this work, we successfully constructed a novel fluorescent DNA aptasensor, which originated from the binding reaction between the improved DNA fluorescent light-up aptamer termed S2T3AT-GC and a small fluorescent molecule termed DFHBI-1T (S2T3AT-GC/DFHBI-1T) to realize fast and anti-interference response for Cu2+via the competitive interaction between Cu2+ and S2T3AT-GC (Cu2+/S2T3AT-GC) destroying the contained G-quadruplex structure of S2T3AT-GC. Moreover, it enables the sensitive detection of Cu2+ with a detection limit of 0.3 µM and a wide detection linear range from 0.3 to 300 µM. Moreover, with the verification of high stability in real industrial sewage samples, this aptasensor exhibits excellent detection performance for Cu2+ analysis in real water samples. Therefore, the proposed aptasensor exhibits great potential in exploring Cu2+-related environmental and ecological research.

Engineering of An Aptamer-Functionalized Fluorescent DNA Sensor for Cu(II) Responding in Living Tumor Cells.

Copper ions play vital roles in regulating life processes and being closely involved in several diseases such as cancer. Although detection methods based on fluorescent sensors or other strategies have been developed, it still remains a challenge to simultaneously realize the convenience, specificity, and accuracy in intracellular copper ion analysis. Herein, we propose an aptamer-functionalized DNA fluorescent sensor (AFDS) for accurate and specific detection of Cu(II) both in vitro and in cells by engineering the linkage of two DNA aptamers, namely, Lettuce aptamer and AS1411 aptamer, to achieve the manner of recognition response. Taking advantage of the functions of each aptamer, the tumor cell recognition capability and the high-contrast detection performance are simultaneously equipped in the AFDS. Furthermore, the AFDS shows high specificity and selectivity in Cu(II) response to avoid interference from common metal ions, chelators, and reactants by being associated with the irreversible interaction between nucleobases and Cu(II), which can destroy the topological structures and switch off the fluorescence of the AFDS. It also enables a sensitive in vitro detection of Cu(II) with a detection limit as lower as 0.1 µM and a wide detection linear range from 0.1 to 300 µM. The feasibility and superiority of the AFDS provide an opportunity to reveal both concentration-dependent and time-dependent intracellular Cu(II) responses in living cells. Therefore, the AFDS has achieved the novel detection performance of Cu(II) to exhibit great potential in exploring copper-related biological and pathological research.

Controllable synthesis of MoS2@TiO2 nanocomposites for visual detection of dopamine secretion with highly-efficient enzymatic activity.

Dopamine (DA) plays an essential role in dopaminergic neuronal behavior and disease. However, current detection methods for discriminating the secretion of DA are hampered by the limitations of the requirement for bulky instrumentation and non-intuitive signals. Herein, we have controllably and proportionately integrated molybdenum disulfide (MoS2) with titanium dioxide (TiO2) to prepare MoS2@TiO2 nanocomposites (MoS2@TiO2 NCs) via a facile synthesis method. MoS2@TiO2 NCs with a certain reactant mass ratio have shown a significant enhancement in peroxidase-like activity with superiority of the nanocomposite structure compared to single MoS2 or natural enzyme. The method for catalyzing the decomposition of H2O2 by MoS2@TiO2 NCs and competition for hydroxyl radicals (˙OH) between the chromogenic agent and DA enable a sensitive, specific, and colorimetric DA analysis with a low detection limit of 0.194 µM and a wide linear detection range (0.8 to 100 µM). Because of the favorable detection performance, we were encouraged to explore and finally realize the visual detection of cellular DA secretion that is stimulated in a High-K+ neurocyte environment. Collectively, this method will provide a promising strategy for basic research in neuroscience with its portable, sensitive, and naked-eye detectable performance.

The multifaceted mechanisms of pristimerin in the treatment of tumors state-of-the-art.

As a globally complicated disease, malignant tumor has long been posing a threat to human health with increasingly high morbidity and mortality. Notably, existing treatments for tumors like chemotherapy generally carry intolerable toxicity, necessitating novel agents balancing safety and potency. Among them, the anti-tumor potency of herbs, featuring few adverse effects and promising efficacy, has attracted much attention recently. Pristimerin, a Quinone formamide triterpenoid compound extracted from Celastraceae and Portulacaceae, carries pronounced anti-tumor activity. It applies to various malignant tumors, including breast cancer, bile duct cancer, gastric cancer, pancreatic cancer, prostate cancer, glioblastoma, colorectal cancer, oral squamous cell carcinoma, cervical cancer, and lung cancer. In state-of-the-art understanding, pristimerin, alone or combined, can inhibit tumor cell proliferation, induce tumor cell apoptosis, inhibit tumor migration and invasion, inhibit angiogenesis, induce tumor cell autophagy, regulate the occurrence of inflammation related tumors, enhance chemosensitivity and regulate tumor microenvironment and immune cells. Despite the abundance of pristimerin-based research, systematic reviews on its anti-tumor mechanism remain needed. This study presented the anti-tumor mechanism of pristimerin by literature review, which might serve as a reference for further research and clinical practice.

Research progress on classical traditional Chinese medicine Taohong Siwu decoction in the treatment of coronary heart disease.

The pathogenesis of coronary heart disease is closely related to blood stasis. Taohong Siwu decoction (THSW for short) is one of the most widely used prescriptions for activating blood and removing stasis. Clinical research has confirmed its curative effect on coronary heart disease. However, its underlying mechanism remains unclear. Therefore, this paper reviewed the clinical efficacy of THSW and determine its effective components based on a comprehensive literature review. Furthermore, the core components and targets of THSW in treating coronary heart disease using molecular docking were verified, and the interaction sites were predicted to construct a theoretical basis for the clinical application of THSW.

The multifaceted mechanisms of Paeoniflorin in the treatment of tumors: State-of-the-Art.

Paeoniflorin is a water-soluble monoterpenoid glycoside that can be derived from multiple herbaceous plants, such as Radix Paeoniae Rubra, Radix Paeoniae Alba, Paeonia suffruticosa and Cimicifugae Foetidae. Multiple studies have suggested that Paeoniflorin possesses an excellent anti-tumor effect in variety of tumors, including liver cancer, gastric cancer, breast cancer, lung cancer, pancreatic cancer, colorectal cancer and bladder cancer. It can induce cell apoptosis, inhibit proliferation, invasion and metastasis via different molecular mechanisms, which are mainly involved in nuclear transcription factor kappα (NF-κB), B-cell lymphoma-2(Bcl-2) family, MicroRNA, neural precursor cell expressed developmentally down-regulated protein 4(NEDD4) signaling pathway, transcription activating factor (STAT3), p21, p53/14-3-3 signaling pathway, transforming growth factor-ß1(TGF-ß1)/Smads signaling pathway, Mitogen-activated protein kinase (MAPK) signaling pathway and Notch-1. Current studies on anti-tumor effect and mechanism of action of Paeoniflorin remain unclear. Therefore, this study reviews the research progress in the anti-tumor effect and mechanism of Paeoniflorin in an attempt to provide a new thought and theoretical basis for further development and clinical application of Paeoniflorin.

Clinical application and pharmacological mechanism of Wuling powder in the treatment of ascites: A systematic review and network pharmacological analysis.

Ascites is one of the common complications in patients with decompensated liver cirrhosis and liver cancer. Wuling powder (WLP) is a classic prescription for the treatment of water retention caused by bladder gasification. It is also widely used in the treatment of ascites. This systematic review aimed to evaluate the clinical efficacy of WLP and determine its effective chemical components based on a large number of related pieces of literature. The pharmacological effects and chemical constituents of WLP were summarized. Besides, the clinical research status of WLP in the treatment of ascites caused by liver cancer and cirrhosis was analyzed. The key targets and pathways of WLP in the treatment of ascites based on network pharmacology analysis were also discussed. Furthermore, the core components and core targets of WLP in the treatment of ascites using molecular docking were verified and the interaction sites were predicted, to provide a theoretical and scientific basis for the clinical application of WLP.

Chinese herbal medicine Baoyuan Jiedu decoction inhibits the accumulation of myeloid derived suppressor cells in pre-metastatic niche of lung via TGF-ß/CCL9 pathway.

Baoyuan Jiedu (BYJD for short) decoction, a traditional Chinese medicine formula, is composed of Astragalus, Ginseng, Aconite root, Honeysuckle, Angelica, Licorice, which has the functions of nourishing qi and blood, enhancing immune function, improving quality of life and prolonging survival time of tumor patients. The present study aimed to investigate the effect and mechanism of BYJD decoction on reversing the pre-metastatic niche. We showed that BYJD decoction could prolong the survival time of 4T1 tumor-bearing mice. Moreover, we found that the BYJD decoction inhibited the formation of lung pre-metastatic niche and inhibited recruitment of myeloid derived suppressor cells (MDSCs) in the lung. Mechanistically, we showed that the proteins and genes expression of TGF-ß, Smad2, Smad3, p-Smad2/3, Smad4, CCL9 in the TGF-ß/CCL9 signaling pathway were suppressed by BYJD decoction. In line with the above findings, our results confirm that BYJD decoction inhibits the accumulation of MDSC in pre-metastatic niche of lung via TGF-ß/CCL9 pathway.

Spectroscopic identification of interactions of formaldehyde with bovine serum albumin.

The mechanism of formaldehyde-protein interactions was investigated by determining the effects of formaldehyde on the common protein bovine serum albumin (BSA). The effects at the molecular level were determined by fluorescence, ultraviolet absorption, and circular dichroism (CD) spectrometry. Formaldehyde could decrease the amount of alpha-helix, leading to loosening of the protein skeleton. In the loose structure, internal amino acids are exposed and the characteristic fluorescence of BSA is obviously quenched. The spectroscopic results reveal that formaldehyde exposure induces changes in the microenvironment and conformation of serum albumin, which could lead to toxic effects on the organism.

Impact of carbon chain length on binding of perfluoroalkyl acids to bovine serum albumin determined by spectroscopic methods.

Perfluoroalkyl acids (PFAAs), an emerging class of globally environmental contaminants, pose a great threat to humans with wide exposure from food and other potential sources. To evaluate the toxicity of PFAAs at the protein level, the effects of three PFAAs on bovine serum albumin (BSA) were characterized by fluorescence spectroscopy, synchronous fluorescence spectroscopy, and circular dichroism (CD). On the basis of the fluorescence spectra and CD data, we concluded that perfluoropentanoic acid (PFPA) had little effect on BSA. However, perfluorooctanoic acid (PFOA) and perfluorodecanoic acid (PFDA) exhibited remarkable fluorescence quenching, which was attributed to the formation of a moderately strong complex. The enthalpy change (DeltaH) and entropy change (DeltaS) indicated that van der Waals forces and hydrogen bonds were the dominant intermolecular forces in the binding of PFAAs to BSA. Furthermore, the BSA conformation was slightly altered in the presence of PFOA and PFDA, with a reduction of alpha helix. These results indicated that PFAAs indeed impact the conformation of BSA, and PFAAs with longer carbon chains were more toxic, especially at lower concentrations.

Spectroscopic investigation on the toxic interaction of melamine with herring sperm DNA.

The toxic interaction of melamine with herring sperm DNA (hs-DNA) was investigated by using fluorescence and UV-vis absorption spectra techniques. The experimental results showed that the toxic interaction between melamine and hs-DNA occurred. Fluorescence quenching experiments indicated the existence of electrostatic binding between melamine and hs-DNA. The binding constants K(A) and the binding site numbers were calculated by means of the Stern-Volmer equation and were 9.8 × 10(4) L mol(-1) and 1.3, respectively. Both the results of fluorescence spectra and UV-vis absorption spectra verified that there are electrostatic binding between melamine and hs-DNA. The possibility in the presence of a classical intercalation binding mode could be ruled out by using DNA unwinding experiments.

[Advances in the research of all-ceramic FPD].

The all-ceramic restoration has no metal base,no need to mask, and it also has perfect esthetic attribute. But in the past, lower strength restricted its clinical use. With the development of high strength ceramics, all-ceramic restoration has been widely used than before. Recently, more and more research on all-ceramic materials, laboratory test and clinical test showed good prospect in prosthodontics field.