The dearomatizative dienamine‐type ortho‐quinodimethane species are smoothly generated between 2‐alkyl‐3‐furfurals and chiral secondary amine catalysts, which undergo asymmetric benzylic allylic ...alkylation reactions with 2‐nitroallylic acetates efficiently. A spectrum of densely functionalized 3‐furfural derivatives are delivered in moderate to high yields with good to excellent diastereo‐ and enantioselectivity (up to 98 % yield, >19:1 d.r., >99 % ee). The latent transformations allow the facile production of some enantioenriched architectures, such as 1,1,2,2‐tetraarylethanes and triarylmethanes, which are not easily available from other protocols.
Temporary dearomatization: The dienamine‐type ortho‐quinodimethane species are generated between 2‐alkyl‐3‐(benzo)furan‐3‐carbaldehydes and chiral secondary amines, and undergo benzylic allylic alkylations with 2‐nitroallylic acetates with excellent stereoselectivity (see scheme). Chiral 1,1,2,2‐tetraarylethanes or triarylmethanes are efficiently constructed accordingly.
The development of chemoresistance is a major hurdle for the treatment of colorectal cancer (CRC), which contributes remarkably to the poor clinical prognosis. Nanodrug delivery systems show great ...potential in overcoming chemoresistance, but limited by the lack of identification of chemoresistance targets from cancer patients. In the present study, we enrolled chemotherapy-resistant or sensitive CRC patients and used the next-generation RNA sequencing to reveal that Asporin (ASPN) is highly expressed in tumor tissues from oxaliplatin (OXA)-resistant patients and closely correlated with a poor prognosis of CRC. Downregulation of ASPN reversed OXA resistance and promoted cell apoptosis both in vitro and in vivo. To overcome ASPN-mediated OXA resistance, we constructed a nanoparticle-based co-delivery system (denoted as PPO-siASPN) for simultaneous delivery of OXA and siRNA targeting ASPN (siASPN). PPO-siASPN not only facilitated the intracellular delivery of OXA through the enhanced cellular uptake, but effectively suppressed ASPN expression for synergistic antitumor activity in vitro and in vivo. In the more clinically relevant patient-derived xenograft (PDX) mouse model, systemic administration of PPO-siASPN achieved a remarkable therapeutic effect. This study uncovered the critical role of ASPN in causing OXA resistance in CRC patients and suggests a promising nanoformulation that may be more effective than current standard-of-care medications.
Objective
Dyslipidemia is one of the major public health problems in China. It is characterized by multisystem dysregulation and inflammation, and oxidant/antioxidant balance has been suggested as an ...important factor for its initiation and progression. The objective of this study was to determine the relationship between prevalence of dyslipidemia and measured changes in the levels of proinflammatory cytokines (IL-6, TNF-a, and MCP-1), thiobarbituric acid-reactant substances (TBARS), and serum total antioxidant capacity (TAC) in serum samples.
Study design
A cross-sectional survey with a purposive sampling of 2,631 enrolled participants (age 18–85 years) was performed using the adult population of long-term residents of the municipality of east coast China in Fujian province between the years 2017 and 2019. Information on general health status, dyslipidemia prevalence, and selected mediators of inflammation was collected through a two-stage probability sampling design according to socioeconomic level, sex, and age.
Methods
The lipid profile was conducted by measuring the levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) with an autoanalyzer. Dyslipidemia was defined according to National Cholesterol Education Program Adult Treatment Panel III diagnostic criteria, and patients with it were identified by means of a computerized database. Serum parameters including IL-6/TNF-a/MCP-1, TBARS, and TAC were measured in three consecutive years. Familial history, education level, risk factors, etc. were determined. The association between dyslipidemia and serum parameters was explored using multivariable logistic regression models. Sociodemographic, age, and risk factors were also investigated among all participants.
Results
The mean prevalence of various dyslipidemia in the population at baseline (2017) was as follows: dyslipidemias, 28.50%; hypercholesterolemia, 26.33%; high LDL-C, 26.10%; low HDL-C, 24.44%; and hypertriglyceridemia, 27.77%. A significant effect of aging was found among all male and female participants. The mean levels of serum Il-6/TNF-a/MCP-1 were significantly higher in all the types of dyslipidemia among male participants. Female participants with all types of dyslipidemia but low HDL-C showed an elevation of IL-6 and MCP-1 levels, and those with dyslipidemias and hypercholesterolemia presented higher levels of TNF-a compared to the normal participants. The oxidative stress marker TBARS increased among all types of dyslipidemia except hypertriglyceridemia. All participants with different types of dyslipidemia had a lower total antioxidant capacity. Correlation analysis showed that cytokines and TBARS were positively associated with age, obesity, and diabetes mellitus, but not sex, sedentary leisure lifestyle, hypertension, and CVD/CHD history. The activity of TAC was negatively associated with the above parameters.
Conclusions
The correlation between the prevalence of dyslipidemia and the modification of inflammation status was statistically significant. The levels of proinflammatory cytokines, oxidative stress, and antioxidant capacity in serum may reflect the severity of the lipid abnormalities. These promising results further warrant a thorough medical screening in enhanced anti-inflammatory and reduced oxidative stress to better diagnose and comprehensively treat dyslipidemia at an early stage.
Signet ring cell carcinoma (SRCC) is a malignant tumor of the digestive system. This tumor has long been considered to be poorly differentiated and highly invasive because it has a higher rate of ...metastasis than well-differentiated adenocarcinoma. But some studies in recent years have shown that the prognosis of some SRCC is more favorable than other poorly differentiated adenocarcinomas, which suggests that SRCC has different degrees of biological behavior. Therefore, we need to find a histological stratification that can predict the biological behavior of SRCC. Some studies indicate that the morphological status of cells can be linked to the invasiveness potential of cells, however, the traditional histopathological examination can not objectively define and evaluate them. Recent improvements in biomedical image analysis using deep learning (DL) based neural networks could be exploited to identify and analyze SRCC. In this study, we used DL to identify each cancer cell of SRCC in whole slide images (WSIs) and quantify their morphological characteristics and atypia. Our results show that the biological behavior of SRCC can be predicted by quantifying the morphology of cancer cells by DL. This technique could be used to predict the biological behavior and may change the stratified treatment of SRCC.
Tensor completion aims to reconstruct a high-dimensional data from the partial element missing tensors under a low-rank constraint, which may be seen as a least-squares problem on manifold. In this ...paper, we propose a new Riemannian conjugate gradient method for the tensor completion which performs Riemannian optimization techniques on a fixed transformed multi-rank tensor manifold. More specifically, we generalize the classical Dai-Yuan conjugate gradient method from the Euclidean space to the manifold with fixed rank, and developed within the framework of retraction-based optimization on manifold. Finally, the convergence properties of the proposed algorithm are derived. Numerical experiments with synthetic data and real images demonstrate the feasibility and effectiveness of our approach.
Celery is a widely cultivated vegetable abundant in ascorbate (AsA), a natural plant antioxidant capable of scavenging free radicals generated by abiotic stress in plants. Ascorbate peroxidase (APX) ...is a plant antioxidant enzyme that is important in the synthesis of AsA and scavenging of excess hydrogen peroxide. However, the characteristics and functions of APX in celery remain unclear to date.
In this study, a gene encoding APX was cloned from celery and named AgAPX1. The transcription level of the AgAPX1 gene was significantly upregulated under drought stress. AgAPX1 was expressed in Escherichia coli BL21 (DE3) and purified. The predicted molecular mass of rAgAPX1 was 33.16 kDa, which was verified by SDS-PAGE assay. The optimum pH and temperature for rAgAPX1 were 7.0 and 55 °C, respectively. Transgenic Arabidopsis hosting the AgAPX1 gene showed elevated AsA content, antioxidant capacity and drought resistance. Less decrease in net photosynthetic rate, chlorophyll content, and relative water content contributed to the high survival rate of transgenic Arabidopsis lines after drought.
The characteristics of APX in celery were different from that in other species. The enhanced drought resistance of overexpressing AgAPX1 in Arabidopsis may be achieved by increasing the accumulation of AsA, enhancing the activities of various antioxidant enzymes, and promoting stomatal closure. Our work provides new evidence to understand APX and its response mechanisms to drought stress in celery.
Long noncoding RNAs (lncRNAs) have dense linkages with a plethora of important cellular activities. lncRNAs exert functions by linking with corresponding RNA-binding proteins. Since experimental ...techniques to detect lncRNA-protein interactions (LPIs) are laborious and time-consuming, a few computational methods have been reported for LPI prediction. However, computation-based LPI identification methods have the following limitations: (1) Most methods were evaluated on a single dataset, and researchers may thus fail to measure their generalization ability. (2) The majority of methods were validated under cross validation on lncRNA-protein pairs, did not investigate the performance under other cross validations, especially for cross validation on independent lncRNAs and independent proteins. (3) lncRNAs and proteins have abundant biological information, how to select informative features need to further investigate. Under a hybrid framework (LPI-HyADBS) integrating feature selection based on AdaBoost, and classification models including deep neural network (DNN), extreme gradient Boost (XGBoost), and SVM with a penalty Coefficient of misclassification (C-SVM), this work focuses on finding new LPIs. First, five datasets are arranged. Each dataset contains lncRNA sequences, protein sequences, and an LPI network. Second, biological features of lncRNAs and proteins are acquired based on Pyfeat. Third, the obtained features of lncRNAs and proteins are selected based on AdaBoost and concatenated to depict each LPI sample. Fourth, DNN, XGBoost, and C-SVM are used to classify lncRNA-protein pairs based on the concatenated features. Finally, a hybrid framework is developed to integrate the classification results from the above three classifiers. LPI-HyADBS is compared to six classical LPI prediction approaches (LPI-SKF, LPI-NRLMF, Capsule-LPI, LPI-CNNCP, LPLNP, and LPBNI) on five datasets under 5-fold cross validations on lncRNAs, proteins, lncRNA-protein pairs, and independent lncRNAs and independent proteins. The results show LPI-HyADBS has the best LPI prediction performance under four different cross validations. In particular, LPI-HyADBS obtains better classification ability than other six approaches under the constructed independent dataset. Case analyses suggest that there is relevance between ZNF667-AS1 and Q15717. Integrating feature selection approach based on AdaBoost, three classification techniques including DNN, XGBoost, and C-SVM, this work develops a hybrid framework to identify new linkages between lncRNAs and proteins.
Dihydroartemisinin (DHA) has been found to inhibit the expression of von Willebrand factor (VWF), a marker of endothelial cell injury, but its mechanism in cerebral ischemia/reperfusion (I/R) injury ...remains obscure. In this study, I/R model was constructed through middle cerebral artery occlusion (MCAO) in rats, followed by DHA administration. The effect of DHA on rat cerebral I/R injury was investigated by 2,3,5-triphenyltetrazolium chloride staining, hematoxylin and eosin staining, TUNEL staining, and Western blot. Brain microvascular endothelial cells (BMVECs) isolated from newborn rats were exposed to oxygen–glucose deprivation/reoxygenation (OGD/R), and then treated with DHA. The results showed that MCAO treatment induced infarction, nerve cell apoptosis, and brain tissue impairment in rats, which was mitigated by DHA. OGD/R inhibited viability and accelerated apoptosis of BMVECs, which was alleviated by DHA. I/R procedures or OGD/R up-regulated expressions of VWF, ATG7, Beclin1, and LC3-II/LC3-I ratio, while down-regulating Occludin, Claudin-5, ZO-1, P62, SIRT1, and FOXO1 expressions
and
; however, these effects of I/R procedures or OGD/R were offset by DHA. VWF overexpression reversed the above effects of DHA on OGD/R-induced BMVECs. In summary, DHA ameliorates cerebral I/R injury in rats by reducing VWF level and activating autophagy-mediated SIRT1/FOXO1 signaling pathway.
The design of artificial ion channels with high activity, selectivity and gating function is challenging. Herein, we designed the light‐driven motor molecule MC2, which provides new design criteria ...to overcome these challenges. MC2 forms a selective K+ channel through a single molecular transmembrane mechanism, and the light‐driven rotary motion significantly accelerates ion transport, which endows the irradiated motor molecule with excellent cytotoxicity and cancer cell selectivity. Mechanistic studies reveal that the rotary motion of MC2 promotes K+ efflux, generates reactive oxygen species and eventually activates caspase‐3‐dependent apoptosis in cancer cells. Combined with the spatiotemporally controllable advantages of light, we believe this strategy can be exploited in the structural design and application of next‐generation synthetic cation transporters for the treatment of cancer and other diseases.
Inspired by the functions of biological motors, a light‐driven motor molecule was designed that inserts into the lipid membrane and transports ions with high ion selectivity and gating function. The light‐driven motor rotation accelerates K+ efflux and induces caspase‐dependent apoptosis of cancer cells.
Covert channels are usually used to circumvent security policies and allow information leakage without being observed. In this paper, we propose a novel covert channel technique using the packet ...reordering phenomenon as a host for carrying secret communications. Packet reordering is a common phenomenon on the Internet. Moreover, it is handled transparently from the user and application-level processes. This makes it an attractive medium to exploit for sending hidden signals to receivers by dynamically manipulating packet order in a network flow. In our approach, specific permutations of successive packets are selected to enhance the reliability of the channel, while the frequency distribution of their usage is tuned to increase stealthiness by imitating real Internet traffic. It is very expensive for the adversary to discover the covert channel due to the tremendous overhead to buffer and sort the packets among huge amount of background traffic. A simple tool is implemented to demonstrate this new channel. We studied extensively the robustness and capabilities of our proposed channel using both simulation and experimentation over large varieties of traffic characteristics. The reliability and capacity of this technique have shown promising results. We also investigated a practical mechanism for distorting and potentially preventing similar novel channels.
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