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This study sought to investigate the inhibitory effect of pre-gelatinized dialdehyde starch (P-DAS) on the deterioration of sea cucumber during high-temperature sterilization.It was found that pre-gelatinization reduced crystallinity and average molecular weight of dialdehyde starch (DAS), exposed free aldehyde groups, improved the solubility, and unified the particle sizes. According to the texture profiles of sea cucumber, the crosslinking power of P-DAS was higher than that of DAS. The results of free amino content, total soluble substance, water retention, water distribution, relaxation time and scanning electron microscopy all showed that the crosslinking effect was dose-dependent on crosslinking agent.These results have proved that large molecules such as P-DAS, when properly handled, could also efficiently enter collagen hydrogels and perform crosslinking, providing reference for the development of new protein food stabilizing agents. © 2022 Society of Chemical Industry.

Rehydrated sea cucumber (RSC) is a popular seafood in northeast Asia with high deep-processing potential. Yet the development of value-added RSC product is limited by non-enzymatic decrosslinking of RSC collagen hydrogel system, which could potentially be solved by crosslinking enhancement. In this work, NaIO

Background: Brain metastases (BM) are the most common malignant tumors affecting the human central nervous system, more than 50% of BM are lung cancer. However, there is currently no universal and effective screening tool for lung cancer with BM. The study aimed to identify key genes of lung cancer with BM, achieving early and accurate diagnosis of lung cancer with BM and long-term monitoring of the therapeutic response.Methods: RNA-seq data and related clinical information were downloaded from the Gene Expression Omnibus (GEO) database. The weighted gene co-expression network (WGCNA) analysis was performed using WGCNA package and MEtuequois module was considered as the highest correlation. The Limma package of R was used to obtain differentially expressed genes (DEGs) between lung cancer with BM and healthy samples. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichments of DEGs were analysed. LASSO and SVM were used to derive key genes for lung cancer with BM, and survival analysis was used to verify the correlation between the outcome and the key genes that we found. Key genes are annotated by GSEA, and CIBERSORT was used to calculate immune infiltration from samples.Results: 5 co-expression modules were detected, and ME turquois was most significantly associated with BM in lung cancer. These genes were mainly enriched in biological processes related to cell adhesion and immunity, and the main signaling pathways are significantly related to disease and cell adhesion. 4 BM-related key genes (AQP1, GSTA1, ROS1, TGFB1I1) were identified by LASSO regression analysis and SVM-RFE screening, they were demonstrated as the potential markers for lung cancer with BM. Immune cell infiltration revealed that they were negatively correlated with T cells regulatory, T cells CD8 and Mast cells activated. Overall survival correlation analysis confirmed that the expression of AQP1, GSTA1 and TGFB1I1 was negatively correlated with the prognosis of lung cancer patients, ROS1 was positively correlated with the prognosis of patients.Conclusions: AQP1, GSTA1, TGFB1I1 and ROS1 were identified as key genes of lung cancer with BM patients, which may regulate cancer progression by regulating immunity and have potential prognostic effects.

Introduction: Increasing evidence indicates that lncRNA TUG1 represents an oncogenic factor in cancer. But, the mechanisms by which lncRNA TUG1 contributes to lung adenocarcinoma (LAC) remain undocumented. Methods: The relationship between lncRNA TUG1/miR-138-5p expression and clinical outcomes in patients with LAC was indicated by qPCR, FISH, and TCGA cohort. Gain- or loss-of-function experiments and in vivo tumorigenesis were used to assess the role of lncRNA TUG1 in LAC. The interplay between TUG1 and miR-138-5p was validated by luciferase gene report and RIP assays. qPCR and Western blot analyses were used to investigate the effects of TUG1 on miR-138-5p/HIF1A axis in LAC cells. Results: We found that upregulation of TUG1 or downregulation of miR-138-5p was associated with lymph node or distant metastasis and indicated a poor survival in LAC. Reduced expression of TUG1 restrained the growth of LAC cells, while restored expression of TUG1 had the opposite effects. TUG1 was identified to negatively regulate miR-138-5p expression, and miR-138-5p reversed TUG1-induced cell proliferation by targeting HIF1A. Elevated expression of HIF1A predicted a poor survival in LAC. Conclusion: Our findings demonstrate that lncRNA TUG1 promotes the growth of LAC by regulating miR-138-5p-HIF1A axis.

ObjectivesTo assess the health utilisation status and associated factors among African migrants in China.DesignA national cross-sectional study was conducted among African migrants in China in 2019.SettingParticipants were recruited online and offline to participate in a self-report survey. Online participants were recruited through WeChat across China, and offline participants were recruited in Guangzhou.ParticipantsWe recruited participants who were from an African country; had spent at least 1 month cumulatively in China; were at least 18 years old; were willing to provide informed consent. A total of 1025 participants were recruited online and offline, 19 of them were excluded due to invalid response and 1006 people were finally included in the analysis.Outcome measuresThe primary outcome was health service utilisation and associated factors among African migrants during their stay in China in the past 12 months. The potential factors include the predisposing factors (demographic characteristics and social structure variables), enabling factors (annual income, health insurance in China) and need factors (non-communicable chronic and infectious diseases, depression) which determined by Anderson framework were measured.ResultsEight hundred and seven online and 218 offline participants completed the survey, including 624 males and 382 females, with an average age of 26.4±8.9 years. Around 28.5% reported health utilization in the past 12 months. Results showed that longer duration in China, migration to China for business (aOR=2.23, 95% CI:1.13-4.40) and study (aOR=5.00, 95% CI:2.74-9.11), living in apartment (aOR=2.59, 95% CI:1.62-4.14) or dormitory (aOR=3.22, 95% CI:2.17-4.80) in China, suffering from chronic diseases, communicable diseases, and greater depressive symptoms (aOR=1.91, 95% CI:1.42-2.56) facilitated health service utilization.ConclusionsThe healthcare service that African migrants received in China is low. The existing public health policies and intervention measures need to be improved to make health utilisation more accessible and feasible for African migrants.

Background Leukemia is a hematological malignancy characterized by the proliferation of early lymphoid precursors that replaces normal hematopoietic cells of the bone marrow. Nakhi (Naxi) ethnic minorities considered to be an area of low incidence. MicroRNAs (miRNAs) are a class of small noncoding RNAs that regulate the expression of other genes in various biological processes. The purpose of this work is to study the molecular mechanism of miRNAs in the leukemia from Naxi. Methods Six leukemia patients (case 2 to case 7) and one healthy person (case 1) from Nakhi (Naxi) ethnic minorities were recruited. Total RNA was extracted from these samples and small RNA deep sequencing was performed. Results A list of miRNAs (1,392 known and candidate 125 novels) expressed in leukocytes were identified, and many differentially regulated targets involved in several cellular pathways, such as cancer, Rap1 signaling pathway, Ras signaling pathway, and endocytosis. Additionally, quantitative real time-polymerase chain reaction (qRT-PCR) results show that hsa-miR-181b-5p, hsa-miR-181a-3p, hsa-miR-181a-5p, and hsa-miR-342-3p has different expression patterns in different cancer cells, hsa-miR-450a-5p, and hsa-miR-1255a were dysregulated in all leukemia cells. Conclusions Several abnormal expressed miRNAs in leukemia patients were identified, the correlation of miRNAs dysregulation and leukemia biology demonstrates that specific miRNA can be potential therapeutic target.

Endothelial cells (ECs) are a critical component of the hematopoietic niche, and the cross-talk between ECs and leukemia was reported recently. This study aimed to determine the genes involved in the proliferation inhibition of endothelial cells in leukemia.Human umbilical vein endothelial cells (HUVEC) were cultured alone or co-cultured with K562 cell lines. GeneChip assays were performed to identify the differentially expressed genes. The Celigo, MTT assay, and flow cytometric analysis were used to determine the effect of RNAi DIDO on cell growth and apoptosis. The differently expressed genes were verified by qRT-PCR (quantitative real-time PCR) and western-blot.In K562-HUVEC co-cultured cell lines, 323 down-regulated probes were identified and the extracellular signal-regulated kinase 5 (ERK5) signaling pathway was significantly inhibited. Among the down-regulated genes, theThe knock-down of

Background: Migrants from Sub-Saharan Africa to China faced challenges in accessing healthcare. Less is known about their depression prevalence. We aim to address this gap by providing an initial estimation on the depression prevalence and its correlates. Methods: A cross-sectional survey was conducted from August to October in 2019. Eligibility was defined as being originally from a Sub-Saharan African country and cumulative residence in China for at least one month. A convenience sample was drawn from snowball sampling online and venue-based sampling by community outreach. The primary outcome depression was measured by the Centre for Epidemiologic Studies Depression Scale using 16 as the cutoff. Multivariable logistic regressions were employed to examine the association between depression and its migration-related correlates. Data were analyzed using SAS 9.4. Results: The depression prevalence was high at 44% among 928 participants. Depression was positively associated with unsatisfactory housing conditions (aOR: 1.7, 95%CI: 0.8 to 3.3) and perception of very unfriendly attitudes from the local people (aOR: 4.5, 95%CI: 1.2 to 16.1) after adjusting for covariates. Conclusions: Depression is prevalent among Sub-Saharan Africa migrants in China and warrants attention and intervention. Support should be provided during the post-migration period in China to mitigate depression risks for Sub-Saharan Africa migrants. Future studies are needed to build more evidence on Sub-Saharan Africa migrants’ mental health and to inform global health policies and programming.

In the present study, we characterized the microbiomes of acute leukemia (AL) patients who achieved complete remission following remission induction chemotherapy (RIC) as outpatients, but who did not receive antimicrobials to treat or prevent febrile neutropenia. Saliva and stool samples from 9 patients with acute myeloid leukemia, 11 patients with acute lymphoblastic leukemia, and 5 healthy controls were subjected to 16S ribosomal RNA sequencing at baseline and at 3 months following RIC. Only patients who achieved remission at 3 months post-treatment were included. We excluded anyone who used antimicrobials within 2 months of enrollment or at any time during the study period. At baseline, the relative abundances of species of Prevotella maculosa (P=0.001), Megasphaera micronuciformis (P=0.014), Roseburia inulinivorans (P=0.021), and Bacteroides uniformis (P=0.004) in saliva and Prevotella copri (P=0.002) in the stools of controls were significantly higher than in AL patients. Following RIC, the relative abundances of Eubacterium sp. oral clone DO008 (P=0.012), Leptotrichia sp. oral clone IK040 (P=0.002), Oribacterium sp. oral taxon 108 (P=0.029), Megasphaera micronuciformis (P=0.016), TM7 phylum sp. oral clone DR034 (P

Background Vascular occlusion during hepatectomy accompanies ischemia-reperfusion (IR) injury, which can cause liver dysfunction and affect patients' outcome. Ulinastatin or urinary trypsin inhibitor (UTI), a polyvalent inhibitor of various enzymes, has been confirmed of anti-IR injury effect in recent studies. Here we performed a systematic review and meta-analysis to assess the benefits of perioperation UTI using to protect liver function in hepatectomy. Methods Randomized controlled trials (RCTs) evaluating UTI in hepatectomy were identified. Two independent reviewers extracted data on basic characteristics and risk of bias in the studies, and on outcomes such as alanine transaminase (ALT), aspartate transaminase (AST), and total bilirubin (TBIL) from 1 to 7 days after operation. Results A total of 9 RCTs including 408 UTI and 372 control participants were identified. There was no significant difference in basic characteristics such as age or sex. The majority of the patients who underwent hepatectomy had primary liver carcinoma, liver metastases and benign liver lesions. A significant improvement in liver function was associated with UTI use not only at 1 and 3 days postoperatively, but also at 7 days (all P≤0.01). However, significant heterogeneity existed between the pooled studies (all P Conclusions UTI has positive protective effects against IR injury in hepatectomy. However, further highquality RCTs are needed to confirm this conclusion.

This study aimed to explore role of dendritic cells (DCs) fused with endothelial progenitor cells (EPCs) in inhibiting angiogenesis in acute myeloid leukemia (AML) mice. EPCs were isolated from human AML bone marrow mononuclear cells and fused with DCs, which were then injected back into AML mice. Changes in leukemia cells, micro-vessel density (MVD), early EPC molecular markers vascular endothelial growth factor receptor 2 (VEGFR2/KDR) and CD133 in bone marrow were measured. The results indicated that CD133 and KDR expression in EPCs was significantly higher than in epithelial cells (HUVECs). There were 46.14% ± 8.21% DCs doubly positive for VEGFR2 and CD11c, and it was 8.53% ± 1.27% in co-culture group. Fusion rate of DC/EPCs was 37.61% ± 6.94%, and 35.63% ± 6.09% in DC/ECs group. Growth rate of DC/EPCs was faster than that of EPCs (P0.05). Positive expression of CD133 and VEGFR2 in bone marrow biopsies of AML mice was significantly higher than that in control mice (P

In order to improve the performance of traditional fingerprint detection method in the process of tracking the shared bicycle, the inertial sensor is used for data measurement. The particle filter (PF) method is a widely used sensor fusion algorithm, but the initialisation and weighting processes are problematic in shared bicycle positioning systems. In this paper, a new PF scheme is proposed, and it can produces smooth and stable localised knowledge. However, the feed-forward network that uses the single hidden layer is used to simulate the estimation and improvement of the performance of multiple probability to achieve the distinction of similar fingerprints. At the same time, the random sample consensus algorithm (RANSAC) is used to initialise the algorithm so as to reduce the convergence time. Experiments show that the tracking error of this scheme is less than 1.2 m, which is superior to the selected comparison method.

Background: Diabetic nephropathy (DN) is the most important complication of diabetes and the most common cause of end-stage renal disease (ESRD). Aims: A recent study established that the Ramulus mori polysaccharides (RMP) exert antioxidant effects on DN in rats. Methods: The diabetic rats which induced by high-fat diet and streptozotocin injection were orally administered RMP by doses of 250, 500 and 1000 mg/kg daily for 8 weeks. The effects of RMP on hyperglycemia and other biochemical changes were examined in the sera and kidney tissues. Additionally, the pathological and ultrastructural changes and expressions of nuclear-factor kappa B (NF-κB) and transforming growth factor-ß1 (TGF-ß1) were assessed. Results: The results revealed that the serum levels of blood glucose, total cholesterol (TC) and triglycerides (TG) were significantly decreased by RMP. Furthermore, the blood urea nitrogen (BUN), serum creatinine (SCr) and 24-hour urine protein levels in the RMP-medicated rats were lower than those in untreated diabetic rats. Moreover, treatment of the DN rats with RMP normalized all biochemical changes, including the malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels in the serum and kidney tissues. In contrast, the protein expression levels of NF-κB and TGF-ß1, which were enhanced in the kidneys of DN rats, were reduced by RMP. Conclusion: These results suggest that RMP improving the renal function of diabeitc rats possibly via its ameliorating antioxidant activities.

The mixing behavior of exchangeable, disulfide-based mimics of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and cholesterol has been examined as a function of temperature in host membranes made from DPPC and cholesterol in the liquid-disordered phase (ld), in the liquid-ordered phase (lo), and in the liquid-disordered/liquid-ordered coexistence region (ld/lo). In the ld region, lipid mixing was found to be temperature insensitive, reflecting close to ideal behavior. In contrast, a significant temperature dependence was observed in the lo phase from 45 to 60 degrees C, when 35 or 40 mol % sterol was present. In this region, sterol-phospholipid association was characterized by DeltaHo = -2.06 +/- 0.14 kcal/mol of phospholipid and DeltaS degrees = -4.48 +/- 0.44 cal/K mol of phospholipid. From 60 to 65 degrees C, the mixing of these lipids was found to be insensitive to temperature, and sterol-phospholipid association was now entropy driven; that is, DeltaHo = -0.23 +/- 0.38 kcal/mol of phospholipid and DeltaS degrees = +1.68 +/- 1.12 cal/K mol of phospholipid. In the liquid-disordered/liquid-ordered coexistence region, changes in lipid mixing reflect changes in the phase composition of the membrane.

This paper records, what is believed to be, the first evidence for the reorganization of the liquid-ordered phase by ethanol. Specifically, ethanol has been found to significantly enhance sterol-phospholipid association in liquid-ordered bilayers derived from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) plus cholesterol, and also 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) plus cholesterol. The evidence for such reorganization comes from a series of nearest-neighbor recognition (NNR) experiments that have been carried out, where low concentrations of equilibrating lipid dimers (i.e., “reporter molecules”) have been used to detect changes in the phase composition of host membranes made from varying mixtures of DPPC/cholesterol, and also DSPC/cholesterol, in the presence and in the absence of ethanol. These findings have important biological implications, which are briefly discussed.

(2002). Toward Nano-assembly of Metals Through Engineered DNAs. Supramolecular Chemistry: Vol. 14, No. 2-3, pp. 255-261.

In this context, the pilot project is by adjusting the interest of the parties to achieve the sustainable use of ecosystem services as a means or institutional arrangements. Methods: the mountain town interest groups are divided into implementation group and accept the group to create an asymmetric evolutionary game model to analyze the stability of the replicator dynamics of the relationship between the interests of different groups, evolutionary stable strategies and evolutionary game system. Results: in the case of "Report punishment" system exists, evolutionary game between the two populations exist only stable equilibrium strategy (protection, compensation), that is, the implementation of group selection "to the gentle slope development strategy, accept group selection" differences in compensation policy, to form a stable equilibrium strategy. Conclusion: "Report punishment" to expand the scope and extent of the traditional concept of punishment; stability of the system is only relevant to the implementation of group decision-making; proportion of decision-making is an important factor to promote a stable equilibrium strategy.

Ecological compensation is by adjusting the interest of the parties to achieve the sustainable use of ecosystem services as a means or institutional arrangements. Based on the microscopic dimension, the thesis carried on researches on ecological compensation, established the asymmetric evolution game model through dividing interest groups of ecological compensation into the implementation group and the benefit group, and made the analysis of the replicator dynamics and evolutionary stable strategy of the relationship between interest groups and the stability of the evolutionary game system. The results showed that as the “report-punishment” system existed, there is the only stable equilibrium strategy (protection, compensation) between groups of evolutionary game, namely the implement group chose "protection" strategy, and benefit group chose "compensation" strategy. The implementation of group decision-making dominated system stability. The proportion of interest groups' decision choices decided whether the stable equilibrium strategy can be formed. Implementation group and benefit from the proportion of the group select the "protection" and "compensation" strategy; accelerate the formation of stable equilibrium strategy effectively.

A chelator-type beta-C-nucleoside having a catechol ligand as the nucleobase was found to form a stable 2:1 complex with trimethyl borate, which was characterized by 1H-NMR and electrospray ionization time-of-flight (ESI-TOF) mass spectroscopies. Both phosphoramidite and phosphotriester derivatives of this nucleoside were also prepared as synthetic precursors for DNA oligomer syntheses.

Nearest-neighbor recognition experiments have been carried out using varying ratios of exchangeable dimer analogs of 1,2-dimyristoyl-sn-glycero-3-phosphatidylglycerol and 1,2-distearoyl-sn-glycero-3-phosphatidylglycerol in cholesterol-rich unilamellar vesicles at 60 degrees C. Equilibrium dimer distributions that were obtained support a structural model of the liquid-ordered bilayer in which free cholesterol and the longer-chain phospholipid homodimer are in equilibrium with a complex of unique stoichiometry, where one cholesterol molecule combines with two of the long-chain phospholipid homodimers. In this model, the mixing of the short-chain phospholipids with the uncomplexed long-chain phospholipids is ideal, and the complexed dimers are shielded from the disulfide exchange reaction.

With the fast growth of the microelectronic technology, the smaller and smaller feature size of IC (Integrated Circuit) and the increasing circuit complexity, the optimization of layout based on the distribution of defect is becoming more and more important. Firstly, associating critical area with edge network, a concept of shortest path of redundancy material defect is presented and realized. Secondly, from this, the maximum and minimum yields are derived respectively. Finally, a range of critical area optimization is capable of being ascertained which is a key parameter of layout improvement. Therefore, experiments result shows that the yield has a certain degree of optimization space by the calculation of the shortest path and current yield.

In order to find a harmonious development way of environmental protection and socioeconomic development in middle-upper reaches of the Jinsha River Region, this study made a systematic initial research on the Spatial development Function zone division's theory, methodology and policies system based on synthesized various land planning of predecessors, and divided the Spatial development Function zone for middle-upper reaches of the Jinsha River. It has some significance on the way of environmental protection and socioeconomic development in the eastern regions.

Service component architecture (SCA) is a new promising programming model for constructing service-oriented application, which facilitates the development of business integration in SOA. However, there still lacks the unified theory foundations for the service component assembly based on SCA in a rigorous way. Firstly, a metamodel of the contract-based SCA is proposed by applying the idea of design by contract to the assembly process of service components. Secondly, a signature model for the contract-based SCA is given according to the metamodel, which supports the construction of service-oriented application in a rigorous way. Moreover, reasoning about or verifying the correctness of service components assembly can be implemented based on the semantics of the port protocol. Finally, the online shop case study is discussed to illustrate how to construct a service-oriented application in a rigorous way.

Nearest-neighbor recognition measurements have established that the effects of deuterium substitution on phospholipid mixing are exceedingly small. Thus, the mixing behavior of an exchangeable phospholipid bearing two stearoyl chains with a homologue containing two myristoyl chains in gel-fluid bilayers, fluid bilayers, cholesterol-rich fluid bilayers, and gel-fluid bilayers that have been enriched with cholesterol correspond to a difference in the free energy of mixing that is less than 2.2 cal/mol of hydrogen in all cases. These findings provide the strongest evidence to date in support of the use of deuterated phospholipids as “nonperturbing” probes for structural and dynamic studies of bilayer membranes.

A non-natural β- C -nucleoside bearing a 3,4-dibenzyloxyphenyl group as a nucleobase ( X ) was synthesized and incorporated into a 34-mer oligomer with the sequence 5′-dTTTTTAAAAAA X ATATAGCAGCGACATGTCACCG-3′. This synthetic oligonucleotide was examined for template activity in the enzymatic syntheses of DNA by the Klenow fragments of Escherichia coli DNA polymerase I and the recombinant DNA polymerase I, and in the synthesis of RNA by the E. coli RNA polymerase core enzyme. As a result, the template-directed polymerization of both DNA and RNA was precisely terminated at the position of X . The X -containing oligonucleotide was also tested for digestion by an exonuclease, Exo III nuclease (Exo III), and an endonuclease, Mung Bean nuclease (MB). The results indicate that the artificial nucleobase X acts as a terminator for digestion by Exo III, whereas the site X becomes susceptible to digestion by MB. These findings provide a useful tool for the size control of products in the synthesis and degradation of nucleic acids.

Five nonnatural beta-C-nucleoside 5'-triphosphates bearing a 3,4-dihydroxyphenyl (1TP), a 2-hydroxyphenyl (2TP), a 3-hydroxyphenyl (3TP), a 4-hydroxyphenyl (4TP), or a phenyl (5TP) group were synthesized, and their structure-activity relationships were examined for a series of DNA polymerase reactions in vitro under typical polymerase chain reaction conditions. We found that the 5'-triphosphates (1TP-5TP) are not incorporated into DNA strands but inhibit the DNA polymerase reactions in the presence of natural nucleoside 5'-triphosphates (dNTPs). 1TP having two phenolic hydroxy groups at the nucleobase moiety showed the most potent inhibitory effect against DNA synthesis by Ex Taq polymerase (IC(50) = 30 microM). The competition assay indicated that 1TP and dNTPs are most likely to affect DNA polymerase reactions competitively. This finding may raise the appealing possibility that artificial nucleoside 5'-triphosphates having phenolic hydroxy groups could exhibit potent inhibitory activity against DNA-directed enzymatic reactions.

The metal-chelating beta-C-nucleoside having a phenylenediamine moiety as the nucleobase was previously found to form a stable 2:1 complex with a Pd(2+) ion in aqueous media, where hydrogen bonding is replaced by metal coordination in the base pairing, thereby creating a novel hybridization motif in duplex DNA. In this regard, we have further designed two types of artificial beta-C-nucleosides possessing a metal-chelating site (a 2-aminophenol or a catechol) as the nucleobase moiety. These artificial nucleosides are directed toward controlling the net charges of the metal-assisted base pairs. This paper describes convenient syntheses of the artificial nucleosides bearing a 2-aminophenol or a catechol moiety. Each nucleoside was directly synthesized through 2'-deoxy derivative via a Friedel-Crafts coupling reaction as the key step between the aromatic ring and ribose moiety, whereas the nucleoside having a phenylenediamine moiety was prepared in rather longer steps through an RNA type intermediate followed by the removal of 2'-hydroxyl group.

The results of nearest-neighbor recognition experiments that have been carried out with exchangeable dimers derived from 1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine, in the presence of cholesterol, dihydrocholesterol, coprostanol, cholestane, cholesteryl methy ether, and sitosterol, provide strong support for a condensing mechanism in which the flexible acyl chains of the phospholipids complement, perfectly, the shape of neighboring sterols, thereby leading to a high number of hydrophobic contacts and tight packing.

Two types of artificial beta-C-nucleosides, 2 and 3, were newly synthesized, which possess a metal chelating site (2-aminophenol and catechol, respectively) at the nucleobase moiety. These nucleosides are expected to form metal-assisted base pairs in oligonucleotides and thereby to control high-order structures and functions of DNAs.

Biomacromolecules such as protein and nucleic acid are excellent functional molecules, which play crutial roles in the vital functions in biological system in an accurate and well-controlled manner. Owing to recent developments in organic synthesis and biotechnology, it has become feasible to chemically modify these molecular structures at the molecular level. An alternative approach she has used for the reconstruction of DNA is the direct modification of nucleobases by incorporating metal-chelating nucleobases into DNA strands. In this artificial DNA, hydrogen-bonded base pairing is replaced by metal-induced base pairing, thereby creating a novel hybridization motif in double-stranded DNA (Chart 1). (Chart 1 was abbreviated.) She has synthesized an artificial β-C-nucleoside 6 which have a catechol group as a nucleobase. This novel nucleoside was synthesized from a 2'-deoxyribose derivartive 1 and О-protected catechol 2 via Friedel-Crafts coupling reaction to selectively afford the desired product β-C-nucleoside 4 in 36% yield. The following two-step deprotection procedures afforded the target β-C-nucleoside 6 (Scheme 1).(Scheme 1 was abbreviated.) Catechol-bearing β-C-nucleoside 6 was treated with half amount of trimethyl borate and triethylamine in DMSO-d6, at room temperature to obtain 2:1 complex 7 between nucleosides and boron (III) (Scheme 2). (Scheme 2 was abbreviated.)The isotopically resolved ESI-TOF mass spectrum of this solution in the negative mode provided clear evidence for the 2:1 complexation between 6 and boron ion. The singnal at m/z 459.15 [7-Et3NH+]- gave excellent agreement between the experimental and theoretical isotopic distributions indicating the boron-assisted dimerization of 6. 500 MHz 1H NMR resonances from aromatic protons of the complex 7 in DMSO-d6 were upfield-shifted from those of the nucleoside 6, and the signals for hydroxy protons on the catechol moiety disappeared upon complexation, whereas those for the ribose moity still remained. These results indicate that phenoxy groups coordinated to the boron (III) center, in the deprotonated form, that is to say a boron (III) ion promoted base pairing of 6. Although there are two possible diastereomeric structures for the complex 7, they only observed one set of proton signals for the complex 7 in the spectrum. She then tried to incorporate a catechol-type β-C-nucleoside as a "chelator- nucleoside" building block into a DNA strand by means of a phosphotriester or a phosphoramidite approach. She synthesized phosphoramidite type 10 and phosphotriester-type 12 and 13, starting from compound 9 (Scheme 3), which can be used to introduce the catechol-type nucleoside into oligo- DNA. (Scheme 3 was abbreviated.) This work demonstrates a novel base pairing mode assisted by borate formation, which would provide an alternative DNA base pair in addition to other metal-assisted base pairs that have been developed in our group so far. This novel base pair at specific site of oligo-DNA would contribute to the development of new structural and functionalized super-biomolecules.