Integrated multicomponent analysis based on ultra-high-performance liquid chromatography coupled with quadrupole-Exactive Orbitrap mass spectrometry and network pharmacology to elucidate the effective constituents and potential mechanism of Zhibai Dihuang pill in treating childhood precocious puberty.

RATIONALE: Childhood precocious puberty (CPP) is a common pediatric endocrine disorder with significant associated risks. Zhibai Dihuang pill (ZBDHP), a classic recipe of the Qing dynasty with its efficacy of nourishing yin and clearing heat, can downregulate the expression of ESR1 in the uterus and ovaries, thereby inhibiting CPP. However, as of now, the main active ingredients and pharmacological mechanisms of ZBDHP remain unclear. METHODS: A comprehensive approach was proposed using ultra-high-performance liquid chromatography coupled with quadrupole-Exactive Orbitrap mass spectrometry (UHPLC-Q-Exactive Orbitrap-MS) and network pharmacology to explore the potentially active constituents of ZBDHP and reveal the underlying mechanisms against CPP. Molecular docking was used to verify the possible mechanisms. RESULTS: A total of 214 constituents derived were identified via UHPLC-Q-Exactive Orbitrap-MS, and 12 of them were definitely characterized using reference standards. Subsequently, compounds tetrahydropalmatine, alisol C, 25-anhydroalisol A 11-acetate, hispidone, cavidine, alisol E, melianone, neogitogenin, denudatin B, and 16ß-hydroperoxyalisol B with related targets PIK3CA, HSD11B1, CYP19A1, AR, PTGS2, CDK2, NR3C1, MMP2, MMP1, and MAPK1 were regarded as key components and targets for ZBDHP treating CPP using the compound-target-pathway network. Besides, the results revealed that the pathways conduced obviously to therapeutic efficacy, including pathways in cancer, neuroactive ligand-receptor interaction, and cyclic adenosine monophosphate（cAMP） signaling pathways. Molecular docking indicated that PIK3CA, HSD11B1, and CYP19A1 exhibited high affinities to corresponding compounds. Overall, the study determined the multicomponent, multitarget, and multipathway mechanisms of ZBDHP against CPP. CONCLUSIONS: This study provided a new method for exploring the chemical constituents and pharmacology mechanism of traditional Chinese medicine.

Comparative Analysis of Hemostatic Efficacy: Local Application of Lancehead Snake Venom Thrombin versus Hemostatic Forceps in Colon Polypectomy.

Background: Colon polypectomy often involves managing bleeding, and the choice of hemostatic methods is critical for patient outcomes. This study addresses the hemostatic effects of lancehead snake venom thrombin compared to hemostatic forceps in the context of colon polypectomy. Objective: To compare and assess the effectiveness and safety of local application of lancehead snake venom thrombin and hemostatic forceps in achieving hemostasis during colon polypectomy. Design: A randomized controlled trial was conducted to investigate and compare the hemostatic outcomes of two different approaches in colon polypectomy. Setting: The study was conducted at the Affiliated Hospital of Hebei University Hospital from January 2022 to June 2022. Participants: A total of 80 patients with colon polyps who met the inclusion criteria were randomly assigned to either the lancehead snake venom thrombin group or the hemostatic forceps group. Interventions: In the hemostatic forceps group, hemostatic forceps were employed to seal the wound post-polyp resection. In the lancehead snake venom thrombin group, aluminium potassium sulfate gel, in conjunction with locally sprayed lancehead snake venom thrombin, was applied to the wound. Primary Outcome Measures: The study assessed (1) intraoperative immediate bleeding and hemostasis; (2) intraoperative hemostasis time; (3) postoperative delayed post-polypectomy bleeding (DPPB); and (4) adverse reactions as primary outcome measures. Results: No significant differences were observed in the incidence rate of intraoperative immediate bleeding and the success rate of intraoperative hemostasis between the two groups. The lancehead snake venom thrombin group exhibited a shorter intraoperative hemostasis time and a lower incidence rate of adverse reactions compared to the hemostatic forceps group. No significant difference was found in the incidence rate of postoperative DPPB between the two groups. Conclusion: Local application of lancehead snake venom thrombin proves to be more effective and safer than hemostatic forceps in promptly managing bleeding during colon polypectomy.

Utilizing Integrated UHPLC-Q-Exactive Orbitrap-MS, Multivariate Analysis, and Bioactive Evaluation to Distinguish between Wild and Cultivated Niudali (Millettia speciosa Champ.).

Millettia speciosa Champ. (MSCP) enjoys widespread recognition for its culinary and medicinal attributes. Despite the extensive history of MSCP cultivation, the disparities in quality and bioactivity between wild and cultivated varieties have remained unexplored. In this study, 20 wild and cultivated MSCP samples were collected from different regions in China. We embarked on a comprehensive investigation of the chemical constituents found in both wild and cultivated MSCP utilizing UHPLC-Q-Exactive Orbitrap-MS technology and multivariate analysis such as principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). In total, 62 chemical components were unequivocally identified or tentatively characterized. Via the multivariate statistical analysis, we successfully pinpointed nine compounds with the potential to serve as chemical markers, enabling the differentiation between wild and cultivated MSCP varieties. Moreover, both genotypes exhibited substantial antioxidant and anti-fatigue properties. The bioactivities of wild MSCP were marginally higher when compared to their cultivated counterparts. This study illuminates the impressive antioxidant and anti-fatigue potential present in both wild and cultivated MSCP genotypes, further augmenting the allure of this species and opening new avenues for the economic valorization of MSCP. Hence, this study provides a valuable method for the identification and quality control of MSCP and a method in chemistry and pharmacology to assess an alternative possibility for cultivated MSCP.

Comprehensive evaluation of BRCA1/2 variant interpretation ability among laboratories in China.

High-quality interpretation of BRCA1/2 variants plays a critical role in the clinical practice of precision medicine. However, a comprehensive system to evaluate the quality and accuracy of variant interpretation has yet to be established. This study investigates the performance of an interpretation system in evaluating the capacities of BRCA1/2 interpretation among distinct laboratories in China. The evaluation system is based on a reference database that contains 750 different variants in BRCA1/2 Evaluation was performed among 41 laboratories in China. We classified their performance into five levels. Only level A was considered qualified. This level allows for a 0.3% error rate for clinical decision-related misinterpretation; 26 of 41 laboratories (63%) met the qualified standard, while 7 laboratories were at levels D and E, which indicated egregious mistakes and systemic problems in variant interpretation. Due to strict quality demands, the interpretation of several variants was amended, which largely influenced the quality rate. The number of qualified laboratories would decrease from 26 to 17 if those incorrect recommended interpretations were not corrected. This evaluation system provides a potential approach for standardisation of variant interpretation and lowers the discordance of variant interpretation between different laboratories. A well-designed interpretation ability evaluation is essential to evaluate the interpretation level of laboratories before they provide service in real-world clinical settings.

Clinical and imaging characteristics of patients with bronchogenic cysts: a single-center retrospective analysis.

BACKGROUND: Bronchogenic cysts (BCs) are rare and usually asymptomatic malformations detected during imaging examinations. We aimed to investigate the clinical and imaging characteristics of patients with BCs. METHODS: We retrospectively evaluated patients who received surgery to remove their BCs from January 2015 to January 2019. Their baseline characteristics, clinical information, and imaging results were reviewed. RESULTS: Our study included 129 patients, with 57 males and 72 females and a mean age of 42.7 years old. The most common location for BCs was the mediastinum (67 patients, 51.9%). Fewer than half of the patients (53 patients, 41.1%) reported clinical symptoms, with chest pain being the most common (16 patients, 30.2%). Neck BCs were more frequently observed in young patients (P = 0.002) and were more often associated with thyroid cancer (P = 0.007). A computed tomography scan was the most commonly used method to diagnose BCs in the lung and mediastinum, whereas ultrasound was the most commonly used diagnostic method for neck BCs. The characteristic images were well-defined, thin-wall cystic lesions in varying densities. A few lesions showed small, calcified spots along the rim or cavities. CONCLUSIONS: Although most BCs were found in the mediastinum, their locations could vary in different sex and age groups. Particular attention should be paid to young patients with BCs in the neck to rule out thyroid cancer.

Two previously undescribed phthalides from Talaromyces amestolkiae, a symbiotic fungus of Syngnathus acus.

Amestolkins A (1) and B (2), two previously undescribed phthalides sharing the same planar structure of (1, 5-dihydroxyhexyl)-7-hydroxyisobenzofuran-1(3H)-one were isolated from Talaromyces amestolkiae. Their absolute configurations were elucidated by comprehensive analyses of spectroscopic evidences in high-resolution electrospray mass spectra (HRESIMS) and nuclear magnetic resonance (NMR) combined with electronic circular dichroism (ECD) and NMR calculations. 1 and 2 showed anti-neuroinflammatory activity by inhibiting the gene expressions of proinflammatory factors including C-C motif chemokine ligand 2 (CCL-2), tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6), as well as attenuating the excretion of inducible nitric oxide synthase (iNOS) in BV-2 microglial cells at the concentration of 30 µM.

Comprehensive Quality Evaluation of Polygonatum cyrtonema and Its Processed Product: Chemical Fingerprinting, Determination and Bioactivity.

Processing of Chinese herbal medicines (CHMs) is a traditional pharmaceutical technology in Chinese medicine. Traditionally, proper processing of CHMs is necessary to meet the specific clinical requirements of different syndromes. Processing with black bean juice is considered one of the most important techniques in traditional Chinese pharmaceutical technology. Despite the long-standing practice of processing Polygonatum cyrtonema Hua (PCH), there is little research on the changes in chemical constituents and bioactivity before and after processing. This study investigated the influence of black bean juice processing on the chemical composition and bioactivity of PCH. The results revealed significant changes in both composition and contents during processing. Saccharide and saponin content significantly increased after processing. Moreover, the processed samples exhibited considerably stronger DPPH and ABTS radical scavenging capacity, as well as FRAP-reducing capacity, compared to the raw samples. The IC50 values for DPPH were 1.0 ± 0.12 mg/mL and 0.65 ± 0.10 mg/mL for the raw and processed samples, respectively. For ABTS, the IC50 values were 0.65 ± 0.07 mg/mL and 0.25 ± 0.04 mg/mL, respectively. Additionally, the processed sample demonstrated significantly higher inhibitory activity against α-glucosidase and α-amylase (IC50 = 1.29 ± 0.12 mg/mL and 0.48 ± 0.04 mg/mL) compared to the raw sample (IC50 = 5.58 ± 0.22 mg/mL and 0.80 ± 0.09 mg/mL). These findings underscore the significance of black bean processing in enhancing the properties of PCH and lay the foundation for its further development as a functional food. The study elucidates the role of black bean processing in PCH and offers valuable insights for its application.

Preparation of a miR-155-activating nucleic acid nanoflower to study the molecular mechanism of miR-155 in inflammation.

At present, the molecular mechanisms underlying inflammation remain unclear. In recent years, research on inflammation has focused on stimulating cell inflammation by using exogenous pro-inflammatory substances such as lipopolysaccharide (LPS) or inflammatory factors. To investigate the molecular mechanism of inflammation from a new perspective, we designed a nucleic acid nanoflowers (NFs) complex to directly activate inflammatory genes to study the inflammatory response without the need for external microbial factors to trigger an inflammatory response. An RNAa-type target gene-activated NFs was designed. Human umbilical vein endothelial cells (HUVECs) were transfected with NFs carrying small activating RNA (saRNAs) to directly co-activate microRNA (miR)-155 and SHIP1 genes. After RNA activation (RNAa)-type NFs were transferred into HUVECs, the expression of miR-155 and pro-inflammatory and cancer-related factors increased, anti-inflammatory factors were reduced, cell proliferation increased, and cell migration was promoted. IL-1ß protein levels were decreased and SHIP1 expression was downregulated. When miR-155 and its target SHIP1 were both activated, the expression of both was unaltered, maintaining cell homeostasis. This points towards miR-155 overexpression can trigger inflammation, and that miR-155 and its target genes act as a molecular switch role in the development of inflammation.

Exosome-mediated lncRNA SND1-IT1 from gastric cancer cells enhances malignant transformation of gastric mucosa cells via up-regulating SNAIL1.

BACKGROUND: Gastric cancer (GC), as one of the most common malignancies across the globe, is the fourth leading cause of cancer-related deaths. Though a large body of research has been conducted to develop the therapeutic methods of GC, the survival rate of advanced patients is still poor. We aimed to dig into the potential regulatory mechanism of GC progression. METHODS: Bioinformatics tools and fundamental assays were performed at first to confirm the candidate genes in our study. The functional assays and mechanism experiments were conducted to verify the regulatory mechanisms of the genes underlying GC progression. RESULTS: Long non-coding RNA (lncRNA) SND1 intronic transcript 1 (SND1-IT1) is highly expressed in exosomes secreted by GC cells. SND1-IT1 was verified to bind to microRNA-1245b-5p (miR-1245b-5p) through competitive adsorption to promote ubiquitin specific protease 3 (USP3) messenger RNA (mRNA) expression. SND1-IT1 was validated to recruit DEAD-box helicase 54 (DDX54) to promote USP3 mRNA stability. SND1-IT1 induces malignant transformation of GES-1 cells through USP3. USP3 mediates the deubiquitination of snail family transcriptional repressor 1 (SNAIL1). CONCLUSIONS: Exosome-mediated lncRNA SND1-IT1 from GC cells enhances malignant transformation of GES-1 cells via up-regulating SNAIL1.

Clinical efficiency of simultaneous CNV-seq and whole-exome sequencing for testing fetal structural anomalies.

BACKGROUND: Birth defects are responsible for approximately 7% of neonatal deaths worldwide by World Health Organization in 2004. Many methods have been utilized for examining the congenital anomalies in fetuses. This study aims to investigate the efficiency of simultaneous CNV-seq and whole-exome sequencing (WES) in the diagnosis of fetal anomaly based on a large Chinese cohort. METHODS: In this cohort study, 1800 pregnant women with singleton fetus in Hubei Province were recruited from 2018 to 2020 for prenatal ultrasonic screening. Those with fetal structural anomalies were transferred to the Maternal and Child Health Hospital of Hubei Province through a referral network in Hubei, China. After multidisciplinary consultation and decision on fetal outcome, products of conception (POC) samples were obtained. Simultaneous CNV-seq and WES was conducted to identify the fetal anomalies that can compress initial DNA and turnaround time of reports. RESULTS: In total, 959 couples were finally eligible for the enrollment. A total of 227 trios were identified with a causative alteration (CNV or variant), among which 191 (84.14%) were de novo. Double diagnosis of pathogenic CNVs and variants have been identified in 10 fetuses. The diagnostic yield of multisystem anomalies was significantly higher than single system anomalies (32.28% vs. 22.36%, P = 0.0183). The diagnostic rate of fetuses with consistent intra- and extra-uterine phenotypes (172/684) was significantly higher than the rate of these with inconsistent phenotypes (17/116, P = 0.0130). CONCLUSIONS: Simultaneous CNV-seq and WES analysis contributed to fetal anomaly diagnosis and played a vital role in elucidating complex anomalies with compound causes.

Phytochemistry and Antioxidant Activities of the Rhizome and Radix of Millettia speciosa Based on UHPLC-Q-Exactive Orbitrap-MS.

The root of Millettia speciosa Champ. (MSCP) is used in folk medicine and is popular as a soup ingredient. The root is composed of the rhizome and radix, but only the radix has been used as a food. Thus, it is very important to compare the chemical components and antioxidant activities between the rhizome and radix. The extracts were analyzed by UHPLC-Q-Exactive Orbitrap-MS and multivariate analysis, and the antioxidant activities were evaluated by 2,20-azinobis (3-ethylbenzothiazo-line-6-sulfonic acid) diammonium salt (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays. Ninety-one compounds were detected simultaneously and temporarily identified. Ten compounds were identified as chemical markers to distinguish the rhizome from the radix. The antioxidant activities of the radix were higher than the rhizome. Correlation analysis showed that uvaol-3-caffeate, 3-O-caffeoyloleanolic acid, and khrinone E were the main active markers for antioxidant activity, which allowed for the rapid differentiation of rhizomes and the radix. Therefore, it could be helpful for future exploration of its material base and bioactive mechanism. In addition, it would be considered to be used as a new method for the quality control of M. speciosa.

[Chemical constituents and anti-liver fibrosis mechanism of Meconopsis quintuplinervia based on UPLC-Q-Exactive-MS/MS and network pharmacology].

In this study, UPLC-Q-Exactive-MS/MS was used to rapidly analyze the chemical constituents of Meconopsis quintupli-nervia, and the anti-liver fibrosis mechanism of M. quintuplinervia was preliminarily analyzed by network pharmacology, molecular docking, and cell experiments. The chemical constituents of M. quintuplinervia were identified according to the information of MS~1 and MS~2, as well as the data in the literature and databases. SwissTargetPrediction and TargetNet were used to predict the potential targets. The targets related to liver fibrosis were collected from GeneCards and OMIM. The protein-protein interaction(PPI) network was constructed by STRING. Cytoscape 3.6.1 was used to construct and analyze the "constituent-target-disease" network to obtain key targets and their corresponding constituents in the network. DAVID 6.8 was used for GO analysis and KEGG signaling pathway enrichment analysis. Finally, the preliminary verification was carried out by molecular docking and cell experiments. As a result, 106 chemical constituents were identified from M. quintuplinervia, including 66 flavonoids, 16 alkaloids, 18 phenolic acids, 1 anthocyanin, and 5 other constituents. Among them, 3 constituents were identified as potential new compounds, and 59 constituents were reported in M. quintuplinervia for the first time. Network pharmacology analysis showed that M. quintuplinervia presumably acted on AKT1, SRC, JUN, EGFR, STAT3, HSP90 AA1, MAPK3, and other core targets through luteolin, isorhamnetin, quercetin, apigenin, kaempferide, amurine, 2-methylflavinantine, allocryptopine, the multi and other active compounds, thereby regulating the PI3 K/AKT signaling pathway, pathways in cancer, proteoglycans in cancer, FoxO signaling pathway, and other pathways to exert anti-liver fibrosis effects. M. quintuplinervia extract(MQE) could significantly down-regulate PI3 K and AKT protein levels in the HSC-T6 cell model induced by TGF-ß1, suggesting that MQE may have the ability to regulate the PI3 K/AKT signaling pathway. The findings of this study indicated that the anti-liver fibrosis effect of M. quintuplinervia had multi-constituent, multi-target, and multi-pathway characteristics, which may provide a scientific basis for the research on the pharmacodynamic materials, action mechanism, and quality markers of M. quintupli-nervia.

Recapitulative haematopoietic development of human pluripotent stem cells in the absence of exogenous haematopoietic cytokines.

To improve the recapitulative quality of human pluripotent stem cell (hPSC) differentiation, we removed exogenous haematopoietic cytokines from the defined differentiation system. Here, we show that endogenous stimuli and VEGF are sufficient to induce robust hPSC-derived haematopoiesis, intensive generation of haematopoietic progenitors, maturation of blood cells and the emergence of definitive precursor cells including those that phenotypically identical to early human embryonic haematopoietic stem cells (HSCs). Moreover, the cytokine-free system produces significantly higher numbers of haematopoietic progenitors compared to the published protocols. The removal of cytokines revealed a broad developmental potential of the early blood cells, stabilized the hPSC-derived definitive precursors and led to spontaneous activation of inflammatory signalling. Our cytokine-free protocol is simple, efficient, reproducible and applicable for embryonic stem cells (ESCs) and induced PSCs. The spectrum of recapitulative features of the novel protocol makes the cytokine-free differentiation a preferred model for studying the early human haematopoietic development.

Noninvasive evaluation of early diabetic nephropathy using diffusion kurtosis imaging: an experimental study.

OBJECTIVES: To evaluate the value of renal diffusion kurtosis imaging (DKI) in the diagnosis of early diabetic nephropathy (DN) in a rat model. MATERIALS AND METHODS: Forty male Zucker diabetic fatty rats that spontaneously developed type 2 diabetes mellitus (DM) and 20 age-matched nondiabetic lean Zucker rats were included. Renal DKI scans and histological examinations were performed on the rats in batches at the end of the 4th, 8th, 12th, 16th, and 20th week after DM model was built. Based on renal histopathological appearance, included animals were divided into three groups: a nondiabetic control group, a DM group without DN, and an early DN group. Mean kurtosis (MK) and mean diffusivity (MD) values of renal cortex and medulla were analyzed statistically. RESULTS: MK values of renal cortex and medulla tended to increase from the control group to the early DN group, respectively, while MD values tended to decrease. The cutoff MD and MK values of renal cortex and medulla showed different values in discriminating early DN from controls. Among them, cutoff MK value of medulla of 0.62 was the best parameter (sensitivity, 93.9%; specificity, 96.4%; and area under the curve, 0.95). For discriminate early DN from DM without DN and DM without DN from controls, cutoff MK value of renal cortex or medulla achieved an area under the curve of 0.76-0.85. CONCLUSIONS: MR DKI may be valuable for the noninvasive detection of early DN, and MK value might serve as a more sensitive biomarker of early DN than MD value. KEY POINTS: • In this article, diffusion kurtosis imaging (DKI) was used to detect the changes in the kidneys due to early diabetic nephropathy (DN). • MR DKI may be valuable for the noninvasive detection of early DN. • The mean kurtosis values of renal cortex and medulla might serve as a more sensitive biomarker of early DN than the mean diffusivity values.

Preparation and Characterization of Aptamers Against O,p'-DDT.

The compound 1,1,1-trichloro-2-(p-chlorophenyl)-2-(o-chlorophenyl) ethane (o,p'-DDT) has been identified as one of the endocrine-disrupting chemicals causing adverse effects on wildlife and even humans through bioaccumulation. Its detection has become increasingly important. We have obtained candidate aptamers binding to o,p'-DDT by a systematic evolution of ligands by exponential enrichment (SELEX) protocol. Five out of seventeen candidate sequences were selected for preliminary characterization by SYBR Green I assay. One sequence with highest fluorescence response with o,p'-DDT, designated DDT_13, was chosen for further characterization. Its dissociation constant (Kd) was determined to be 412.3 ± 124.6 nM. DDT_13 exhibited low cross-binding activities on other tested small molecules. The good bioactivities of DDT_13 were demonstrated for the analysis of spiked lake water and tap water samples. This study provides a novel o,p'-DDT-specific probe for its future applications.

Dynamic Mechanics-Modulated Hydrogels to Regulate the Differentiation of Stem-Cell Spheroids in Soft Microniches and Modeling of the Nonlinear Behavior.

Although mechanisms of how physical forces convert into biochemical signals are increasingly understood, it is still unknown how soft cues guide cell behavior. Herein, it is shown that the commitment and differentiation of encapsulating human mesenchymal stem cell (hMSC) spheroids in thermosensitive 3D hydrogels are simply altered by interpenetrating poly(N-isopropylacrylamide-co-2-hydroxyethyl methacrylate) (NIPAM-HEMA) nanogel to a gelatin methacryloyl (GelMA) network. This cell-laden hydrogel provides dynamic mechanics with covalent crosslinking coordinated reversible physical networks, which can regulate hMSCs in situ by reversibly stiffening soft niches via multicyclic temperature changes from 25 to 37 °C. The spreading of hMSC spheroids in the hydrogel is strongly dependent on myosin-dependent traction stress with dynamic mechanical stimuli through focal adhesion kinase (FAK) signaling. Notably, the dynamic microenvironment gradually influences the expression and distribution from the basal to apical side of nuclear lamin A/C and increases the Yes-associated protein (YAP) nuclear localization with cycles, which ultimately favors hMSCs undergoing osteogenesis (but not adipogenesis) in the soft microniche. Moreover, it is demonstrated that the viscoelastic behavior of the soft microniche can be guided by temperature through a nonlinear model. These findings highlight the central roles of the dynamic relationship between the biomechanical signals and mechanosensitive transcriptional regulators in cellular mechanosensing.

Natural Killer Cells and Current Applications of Chimeric Antigen Receptor-Modified NK-92 Cells in Tumor Immunotherapy.

Natural killer (NK) cells are innate immune cells that can be activated rapidly to target abnormal and virus-infected cells without prior sensitization. With significant advancements in cell biology technologies, many NK cell lines have been established. Among these cell lines, NK-92 cells are not only the most widely used but have also been approved for clinical applications. Additionally, chimeric antigen receptor-modified NK-92 cells (CAR-NK-92 cells) have shown strong antitumor effects. In this review, we summarize established human NK cell lines and their biological characteristics, and highlight the applications of NK-92 cells and CAR-NK-92 cells in tumor immunotherapy.

Photoregulating Antifouling and Bioadhesion Functional Coating Surface Based on Spiropyran.

Dynamic regulation of the interactions between specific molecules on functional surfaces and biomolecules, for example, proteins or cells, is critical for biosensor and biomedical devices. Herein, we present a spiropyran (SP)-based light-responsive surface coating, hPG (hyperbranched polyglycerol)-SP, to control the adsorption of proteins and adhesion of cells. In the normal state, the SP groups on the coating surface were in hydrophobic ring-closed form, which promotes the nonspecific protein adsorption and cell adhesion. Under UV irradiation, the grafted SP groups were dynamically isomerized into hydrophilic/zwitterionic merocyanine. Both hydrophilicity and zwitterions support the formation of a hydrated layer and hence the resulting hPG-MC coatings highly resist protein adsorption and cell adhesion. Moreover, the presented hPG also provided a robust bioinert background to suppress the nonspecific protein adsorption and cells adhesion. Therefore, this functionalized coating exhibited a good photoregulated antifouling behavior. Moreover, the detachment of adsorbed proteins and adhered cells from the coating surface was also realized.

Rank-Optimized Logistic Matrix Regression toward Improved Matrix Data Classification.

While existing logistic regression suffers from overfitting and often fails in considering structural information, we propose a novel matrix-based logistic regression to overcome the weakness. In the proposed method, 2D matrices are directly used to learn two groups of parameter vectors along each dimension without vectorization, which allows the proposed method to fully exploit the underlying structural information embedded inside the 2D matrices. Further, we add a joint [Formula: see text]-norm on two parameter matrices, which are organized by aligning each group of parameter vectors in columns. This added co-regularization term has two roles-enhancing the effect of regularization and optimizing the rank during the learning process. With our proposed fast iterative solution, we carried out extensive experiments. The results show that in comparison to both the traditional tensor-based methods and the vector-based regression methods, our proposed solution achieves better performance for matrix data classifications.

DNA methylation mediated by a microRNA pathway.

In plants, the known microRNAs (miRNAs) are produced as approximately 21 nucleotide (nt) duplexes from their precursors by Dicer-like 1 (DCL1). They are incorporated into Argonaute 1 (AGO1) protein to regulate target gene expression primarily through mRNA cleavage. We report here the discovery of a class of miRNAs in the model monocot rice (Oryza sativa). These are 24 nt in length and require another member of the Dicer family, DCL3, for their biogenesis. The 24 nt long miRNAs (lmiRNAs) are loaded into AGO4 clade proteins according to hierarchical rules, depending on the upstream biogenesis machinery and the 5'-terminal nucleotide. We demonstrated that lmiRNAs direct DNA methylation at loci from which they are produced as well as in trans at their target genes and play roles in gene regulation. Considered together, our findings define a miRNA pathway that mediates DNA methylation.